diff --git a/cmd/raidz_test/raidz_test.c b/cmd/raidz_test/raidz_test.c index 4e2639f3676d..e3eb4f4ce44a 100644 --- a/cmd/raidz_test/raidz_test.c +++ b/cmd/raidz_test/raidz_test.c @@ -1,1022 +1,1023 @@ /* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (C) 2016 Gvozden Nešković. All rights reserved. */ #include #include #include #include #include #include #include #include #include #include "raidz_test.h" static int *rand_data; raidz_test_opts_t rto_opts; static char gdb[256]; static const char gdb_tmpl[] = "gdb -ex \"set pagination 0\" -p %d"; static void sig_handler(int signo) { struct sigaction action; /* * Restore default action and re-raise signal so SIGSEGV and * SIGABRT can trigger a core dump. */ action.sa_handler = SIG_DFL; sigemptyset(&action.sa_mask); action.sa_flags = 0; (void) sigaction(signo, &action, NULL); if (rto_opts.rto_gdb) if (system(gdb)) { } raise(signo); } static void print_opts(raidz_test_opts_t *opts, boolean_t force) { char *verbose; switch (opts->rto_v) { case 0: verbose = "no"; break; case 1: verbose = "info"; break; default: verbose = "debug"; break; } if (force || opts->rto_v >= D_INFO) { (void) fprintf(stdout, DBLSEP "Running with options:\n" " (-a) zio ashift : %zu\n" " (-o) zio offset : 1 << %zu\n" " (-e) expanded map : %s\n" " (-r) reflow offset : %llx\n" " (-d) number of raidz data columns : %zu\n" " (-s) size of DATA : 1 << %zu\n" " (-S) sweep parameters : %s \n" " (-v) verbose : %s \n\n", opts->rto_ashift, /* -a */ ilog2(opts->rto_offset), /* -o */ opts->rto_expand ? "yes" : "no", /* -e */ (u_longlong_t)opts->rto_expand_offset, /* -r */ opts->rto_dcols, /* -d */ ilog2(opts->rto_dsize), /* -s */ opts->rto_sweep ? "yes" : "no", /* -S */ verbose); /* -v */ } } static void usage(boolean_t requested) { const raidz_test_opts_t *o = &rto_opts_defaults; FILE *fp = requested ? stdout : stderr; (void) fprintf(fp, "Usage:\n" "\t[-a zio ashift (default: %zu)]\n" "\t[-o zio offset, exponent radix 2 (default: %zu)]\n" "\t[-d number of raidz data columns (default: %zu)]\n" "\t[-s zio size, exponent radix 2 (default: %zu)]\n" "\t[-S parameter sweep (default: %s)]\n" "\t[-t timeout for parameter sweep test]\n" "\t[-B benchmark all raidz implementations]\n" "\t[-e use expanded raidz map (default: %s)]\n" "\t[-r expanded raidz map reflow offset (default: %llx)]\n" "\t[-v increase verbosity (default: %zu)]\n" "\t[-h (print help)]\n" "\t[-T test the test, see if failure would be detected]\n" "\t[-D debug (attach gdb on SIGSEGV)]\n" "", o->rto_ashift, /* -a */ ilog2(o->rto_offset), /* -o */ o->rto_dcols, /* -d */ ilog2(o->rto_dsize), /* -s */ rto_opts.rto_sweep ? "yes" : "no", /* -S */ rto_opts.rto_expand ? "yes" : "no", /* -e */ (u_longlong_t)o->rto_expand_offset, /* -r */ o->rto_v); /* -d */ exit(requested ? 0 : 1); } static void process_options(int argc, char **argv) { size_t value; int opt; raidz_test_opts_t *o = &rto_opts; bcopy(&rto_opts_defaults, o, sizeof (*o)); while ((opt = getopt(argc, argv, "TDBSvha:er:o:d:s:t:")) != -1) { value = 0; switch (opt) { case 'a': value = strtoull(optarg, NULL, 0); o->rto_ashift = MIN(13, MAX(9, value)); break; case 'e': o->rto_expand = 1; break; case 'r': o->rto_expand_offset = strtoull(optarg, NULL, 0); break; case 'o': value = strtoull(optarg, NULL, 0); o->rto_offset = ((1ULL << MIN(12, value)) >> 9) << 9; break; case 'd': value = strtoull(optarg, NULL, 0); o->rto_dcols = MIN(255, MAX(1, value)); break; case 's': value = strtoull(optarg, NULL, 0); o->rto_dsize = 1ULL << MIN(SPA_MAXBLOCKSHIFT, MAX(SPA_MINBLOCKSHIFT, value)); break; case 't': value = strtoull(optarg, NULL, 0); o->rto_sweep_timeout = value; break; case 'v': o->rto_v++; break; case 'S': o->rto_sweep = 1; break; case 'B': o->rto_benchmark = 1; break; case 'D': o->rto_gdb = 1; break; case 'T': o->rto_sanity = 1; break; case 'h': usage(B_TRUE); break; case '?': default: usage(B_FALSE); break; } } } #define DATA_COL(rr, i) ((rr)->rr_col[rr->rr_firstdatacol + (i)].rc_abd) #define DATA_COL_SIZE(rr, i) ((rr)->rr_col[rr->rr_firstdatacol + (i)].rc_size) #define CODE_COL(rr, i) ((rr)->rr_col[(i)].rc_abd) #define CODE_COL_SIZE(rr, i) ((rr)->rr_col[(i)].rc_size) static int cmp_code(raidz_test_opts_t *opts, const raidz_map_t *rm, const int parity) { int r, i, ret = 0; VERIFY(parity >= 1 && parity <= 3); for (r = 0; r < rm->rm_nrows; r++) { raidz_row_t * const rr = rm->rm_row[r]; raidz_row_t * const rrg = opts->rm_golden->rm_row[r]; for (i = 0; i < parity; i++) { if (CODE_COL_SIZE(rrg, i) == 0) { VERIFY0(CODE_COL_SIZE(rr, i)); continue; } if (abd_cmp(CODE_COL(rr, i), CODE_COL(rrg, i)) != 0) { ret++; LOG_OPT(D_DEBUG, opts, "\nParity block [%d] different!\n", i); } } } return (ret); } static int cmp_data(raidz_test_opts_t *opts, raidz_map_t *rm) { int r, i, dcols, ret = 0; for (r = 0; r < rm->rm_nrows; r++) { raidz_row_t *rr = rm->rm_row[r]; raidz_row_t *rrg = opts->rm_golden->rm_row[r]; dcols = opts->rm_golden->rm_row[0]->rr_cols - raidz_parity(opts->rm_golden); for (i = 0; i < dcols; i++) { if (DATA_COL_SIZE(rrg, i) == 0) { VERIFY0(DATA_COL_SIZE(rr, i)); continue; } if (abd_cmp(DATA_COL(rrg, i), DATA_COL(rr, i)) != 0) { ret++; LOG_OPT(D_DEBUG, opts, "\nData block [%d] different!\n", i); } } } return (ret); } static int init_rand(void *data, size_t size, void *private) { int i; int *dst = (int *)data; for (i = 0; i < size / sizeof (int); i++) dst[i] = rand_data[i]; return (0); } static void corrupt_colums(raidz_map_t *rm, const int *tgts, const int cnt) { for (int r = 0; r < rm->rm_nrows; r++) { raidz_row_t *rr = rm->rm_row[r]; for (int i = 0; i < cnt; i++) { raidz_col_t *col = &rr->rr_col[tgts[i]]; abd_iterate_func(col->rc_abd, 0, col->rc_size, init_rand, NULL); } } } void init_zio_abd(zio_t *zio) { abd_iterate_func(zio->io_abd, 0, zio->io_size, init_rand, NULL); } static void fini_raidz_map(zio_t **zio, raidz_map_t **rm) { vdev_raidz_map_free(*rm); raidz_free((*zio)->io_abd, (*zio)->io_size); umem_free(*zio, sizeof (zio_t)); *zio = NULL; *rm = NULL; } static int init_raidz_golden_map(raidz_test_opts_t *opts, const int parity) { int err = 0; zio_t *zio_test; raidz_map_t *rm_test; const size_t total_ncols = opts->rto_dcols + parity; if (opts->rm_golden) { fini_raidz_map(&opts->zio_golden, &opts->rm_golden); } opts->zio_golden = umem_zalloc(sizeof (zio_t), UMEM_NOFAIL); zio_test = umem_zalloc(sizeof (zio_t), UMEM_NOFAIL); opts->zio_golden->io_offset = zio_test->io_offset = opts->rto_offset; opts->zio_golden->io_size = zio_test->io_size = opts->rto_dsize; opts->zio_golden->io_abd = raidz_alloc(opts->rto_dsize); zio_test->io_abd = raidz_alloc(opts->rto_dsize); init_zio_abd(opts->zio_golden); init_zio_abd(zio_test); VERIFY0(vdev_raidz_impl_set("original")); if (opts->rto_expand) { opts->rm_golden = vdev_raidz_map_alloc_expanded(opts->zio_golden->io_abd, opts->zio_golden->io_size, opts->zio_golden->io_offset, opts->rto_ashift, total_ncols+1, total_ncols, parity, opts->rto_expand_offset); rm_test = vdev_raidz_map_alloc_expanded(zio_test->io_abd, zio_test->io_size, zio_test->io_offset, opts->rto_ashift, total_ncols+1, total_ncols, parity, opts->rto_expand_offset); } else { opts->rm_golden = vdev_raidz_map_alloc(opts->zio_golden, opts->rto_ashift, total_ncols, parity); rm_test = vdev_raidz_map_alloc(zio_test, opts->rto_ashift, total_ncols, parity); } VERIFY(opts->zio_golden); VERIFY(opts->rm_golden); vdev_raidz_generate_parity(opts->rm_golden); vdev_raidz_generate_parity(rm_test); /* sanity check */ err |= cmp_data(opts, rm_test); err |= cmp_code(opts, rm_test, parity); if (err) ERR("initializing the golden copy ... [FAIL]!\n"); /* tear down raidz_map of test zio */ fini_raidz_map(&zio_test, &rm_test); return (err); } /* * If reflow is not in progress, reflow_offset should be UINT64_MAX. * For each row, if the row is entirely before reflow_offset, it will * come from the new location. Otherwise this row will come from the * old location. Therefore, rows that straddle the reflow_offset will * come from the old location. * * NOTE: Until raidz expansion is implemented this function is only * needed by raidz_test.c to the multi-row raid_map_t functionality. */ raidz_map_t * vdev_raidz_map_alloc_expanded(abd_t *abd, uint64_t size, uint64_t offset, uint64_t ashift, uint64_t physical_cols, uint64_t logical_cols, uint64_t nparity, uint64_t reflow_offset) { /* The zio's size in units of the vdev's minimum sector size. */ uint64_t s = size >> ashift; uint64_t q, r, bc, devidx, asize = 0, tot; /* * "Quotient": The number of data sectors for this stripe on all but * the "big column" child vdevs that also contain "remainder" data. * AKA "full rows" */ q = s / (logical_cols - nparity); /* * "Remainder": The number of partial stripe data sectors in this I/O. * This will add a sector to some, but not all, child vdevs. */ r = s - q * (logical_cols - nparity); /* The number of "big columns" - those which contain remainder data. */ bc = (r == 0 ? 0 : r + nparity); /* * The total number of data and parity sectors associated with * this I/O. */ tot = s + nparity * (q + (r == 0 ? 0 : 1)); /* How many rows contain data (not skip) */ uint64_t rows = howmany(tot, logical_cols); int cols = MIN(tot, logical_cols); raidz_map_t *rm = kmem_zalloc(offsetof(raidz_map_t, rm_row[rows]), KM_SLEEP); rm->rm_nrows = rows; for (uint64_t row = 0; row < rows; row++) { raidz_row_t *rr = kmem_alloc(offsetof(raidz_row_t, rr_col[cols]), KM_SLEEP); rm->rm_row[row] = rr; /* The starting RAIDZ (parent) vdev sector of the row. */ uint64_t b = (offset >> ashift) + row * logical_cols; /* * If we are in the middle of a reflow, and any part of this * row has not been copied, then use the old location of * this row. */ int row_phys_cols = physical_cols; if (b + (logical_cols - nparity) > reflow_offset >> ashift) row_phys_cols--; /* starting child of this row */ uint64_t child_id = b % row_phys_cols; /* The starting byte offset on each child vdev. */ uint64_t child_offset = (b / row_phys_cols) << ashift; /* * We set cols to the entire width of the block, even * if this row is shorter. This is needed because parity * generation (for Q and R) needs to know the entire width, * because it treats the short row as though it was * full-width (and the "phantom" sectors were zero-filled). * * Another approach to this would be to set cols shorter * (to just the number of columns that we might do i/o to) * and have another mechanism to tell the parity generation * about the "entire width". Reconstruction (at least * vdev_raidz_reconstruct_general()) would also need to * know about the "entire width". */ rr->rr_cols = cols; rr->rr_bigcols = bc; rr->rr_missingdata = 0; rr->rr_missingparity = 0; rr->rr_firstdatacol = nparity; rr->rr_abd_copy = NULL; rr->rr_abd_empty = NULL; rr->rr_nempty = 0; for (int c = 0; c < rr->rr_cols; c++, child_id++) { if (child_id >= row_phys_cols) { child_id -= row_phys_cols; child_offset += 1ULL << ashift; } rr->rr_col[c].rc_devidx = child_id; rr->rr_col[c].rc_offset = child_offset; rr->rr_col[c].rc_gdata = NULL; rr->rr_col[c].rc_orig_data = NULL; rr->rr_col[c].rc_error = 0; rr->rr_col[c].rc_tried = 0; rr->rr_col[c].rc_skipped = 0; rr->rr_col[c].rc_need_orig_restore = B_FALSE; uint64_t dc = c - rr->rr_firstdatacol; if (c < rr->rr_firstdatacol) { rr->rr_col[c].rc_size = 1ULL << ashift; rr->rr_col[c].rc_abd = abd_alloc_linear(rr->rr_col[c].rc_size, B_TRUE); } else if (row == rows - 1 && bc != 0 && c >= bc) { /* * Past the end, this for parity generation. */ rr->rr_col[c].rc_size = 0; rr->rr_col[c].rc_abd = NULL; } else { /* * "data column" (col excluding parity) * Add an ASCII art diagram here */ uint64_t off; if (c < bc || r == 0) { off = dc * rows + row; } else { off = r * rows + (dc - r) * (rows - 1) + row; } rr->rr_col[c].rc_size = 1ULL << ashift; - rr->rr_col[c].rc_abd = - abd_get_offset(abd, off << ashift); + rr->rr_col[c].rc_abd = abd_get_offset_struct( + &rr->rr_col[c].rc_abdstruct, + abd, off << ashift, 1 << ashift); } asize += rr->rr_col[c].rc_size; } /* * If all data stored spans all columns, there's a danger that * parity will always be on the same device and, since parity * isn't read during normal operation, that that device's I/O * bandwidth won't be used effectively. We therefore switch * the parity every 1MB. * * ...at least that was, ostensibly, the theory. As a practical * matter unless we juggle the parity between all devices * evenly, we won't see any benefit. Further, occasional writes * that aren't a multiple of the LCM of the number of children * and the minimum stripe width are sufficient to avoid pessimal * behavior. Unfortunately, this decision created an implicit * on-disk format requirement that we need to support for all * eternity, but only for single-parity RAID-Z. * * If we intend to skip a sector in the zeroth column for * padding we must make sure to note this swap. We will never * intend to skip the first column since at least one data and * one parity column must appear in each row. */ if (rr->rr_firstdatacol == 1 && rr->rr_cols > 1 && (offset & (1ULL << 20))) { ASSERT(rr->rr_cols >= 2); ASSERT(rr->rr_col[0].rc_size == rr->rr_col[1].rc_size); devidx = rr->rr_col[0].rc_devidx; uint64_t o = rr->rr_col[0].rc_offset; rr->rr_col[0].rc_devidx = rr->rr_col[1].rc_devidx; rr->rr_col[0].rc_offset = rr->rr_col[1].rc_offset; rr->rr_col[1].rc_devidx = devidx; rr->rr_col[1].rc_offset = o; } } ASSERT3U(asize, ==, tot << ashift); /* init RAIDZ parity ops */ rm->rm_ops = vdev_raidz_math_get_ops(); return (rm); } static raidz_map_t * init_raidz_map(raidz_test_opts_t *opts, zio_t **zio, const int parity) { raidz_map_t *rm = NULL; const size_t alloc_dsize = opts->rto_dsize; const size_t total_ncols = opts->rto_dcols + parity; const int ccols[] = { 0, 1, 2 }; VERIFY(zio); VERIFY(parity <= 3 && parity >= 1); *zio = umem_zalloc(sizeof (zio_t), UMEM_NOFAIL); (*zio)->io_offset = 0; (*zio)->io_size = alloc_dsize; (*zio)->io_abd = raidz_alloc(alloc_dsize); init_zio_abd(*zio); if (opts->rto_expand) { rm = vdev_raidz_map_alloc_expanded((*zio)->io_abd, (*zio)->io_size, (*zio)->io_offset, opts->rto_ashift, total_ncols+1, total_ncols, parity, opts->rto_expand_offset); } else { rm = vdev_raidz_map_alloc(*zio, opts->rto_ashift, total_ncols, parity); } VERIFY(rm); /* Make sure code columns are destroyed */ corrupt_colums(rm, ccols, parity); return (rm); } static int run_gen_check(raidz_test_opts_t *opts) { char **impl_name; int fn, err = 0; zio_t *zio_test; raidz_map_t *rm_test; err = init_raidz_golden_map(opts, PARITY_PQR); if (0 != err) return (err); LOG(D_INFO, DBLSEP); LOG(D_INFO, "Testing parity generation...\n"); for (impl_name = (char **)raidz_impl_names+1; *impl_name != NULL; impl_name++) { LOG(D_INFO, SEP); LOG(D_INFO, "\tTesting [%s] implementation...", *impl_name); if (0 != vdev_raidz_impl_set(*impl_name)) { LOG(D_INFO, "[SKIP]\n"); continue; } else { LOG(D_INFO, "[SUPPORTED]\n"); } for (fn = 0; fn < RAIDZ_GEN_NUM; fn++) { /* Check if should stop */ if (rto_opts.rto_should_stop) return (err); /* create suitable raidz_map */ rm_test = init_raidz_map(opts, &zio_test, fn+1); VERIFY(rm_test); LOG(D_INFO, "\t\tTesting method [%s] ...", raidz_gen_name[fn]); if (!opts->rto_sanity) vdev_raidz_generate_parity(rm_test); if (cmp_code(opts, rm_test, fn+1) != 0) { LOG(D_INFO, "[FAIL]\n"); err++; } else LOG(D_INFO, "[PASS]\n"); fini_raidz_map(&zio_test, &rm_test); } } fini_raidz_map(&opts->zio_golden, &opts->rm_golden); return (err); } static int run_rec_check_impl(raidz_test_opts_t *opts, raidz_map_t *rm, const int fn) { int x0, x1, x2; int tgtidx[3]; int err = 0; static const int rec_tgts[7][3] = { {1, 2, 3}, /* rec_p: bad QR & D[0] */ {0, 2, 3}, /* rec_q: bad PR & D[0] */ {0, 1, 3}, /* rec_r: bad PQ & D[0] */ {2, 3, 4}, /* rec_pq: bad R & D[0][1] */ {1, 3, 4}, /* rec_pr: bad Q & D[0][1] */ {0, 3, 4}, /* rec_qr: bad P & D[0][1] */ {3, 4, 5} /* rec_pqr: bad & D[0][1][2] */ }; memcpy(tgtidx, rec_tgts[fn], sizeof (tgtidx)); if (fn < RAIDZ_REC_PQ) { /* can reconstruct 1 failed data disk */ for (x0 = 0; x0 < opts->rto_dcols; x0++) { if (x0 >= rm->rm_row[0]->rr_cols - raidz_parity(rm)) continue; /* Check if should stop */ if (rto_opts.rto_should_stop) return (err); LOG(D_DEBUG, "[%d] ", x0); tgtidx[2] = x0 + raidz_parity(rm); corrupt_colums(rm, tgtidx+2, 1); if (!opts->rto_sanity) vdev_raidz_reconstruct(rm, tgtidx, 3); if (cmp_data(opts, rm) != 0) { err++; LOG(D_DEBUG, "\nREC D[%d]... [FAIL]\n", x0); } } } else if (fn < RAIDZ_REC_PQR) { /* can reconstruct 2 failed data disk */ for (x0 = 0; x0 < opts->rto_dcols; x0++) { if (x0 >= rm->rm_row[0]->rr_cols - raidz_parity(rm)) continue; for (x1 = x0 + 1; x1 < opts->rto_dcols; x1++) { if (x1 >= rm->rm_row[0]->rr_cols - raidz_parity(rm)) continue; /* Check if should stop */ if (rto_opts.rto_should_stop) return (err); LOG(D_DEBUG, "[%d %d] ", x0, x1); tgtidx[1] = x0 + raidz_parity(rm); tgtidx[2] = x1 + raidz_parity(rm); corrupt_colums(rm, tgtidx+1, 2); if (!opts->rto_sanity) vdev_raidz_reconstruct(rm, tgtidx, 3); if (cmp_data(opts, rm) != 0) { err++; LOG(D_DEBUG, "\nREC D[%d %d]... " "[FAIL]\n", x0, x1); } } } } else { /* can reconstruct 3 failed data disk */ for (x0 = 0; x0 < opts->rto_dcols; x0++) { if (x0 >= rm->rm_row[0]->rr_cols - raidz_parity(rm)) continue; for (x1 = x0 + 1; x1 < opts->rto_dcols; x1++) { if (x1 >= rm->rm_row[0]->rr_cols - raidz_parity(rm)) continue; for (x2 = x1 + 1; x2 < opts->rto_dcols; x2++) { if (x2 >= rm->rm_row[0]->rr_cols - raidz_parity(rm)) continue; /* Check if should stop */ if (rto_opts.rto_should_stop) return (err); LOG(D_DEBUG, "[%d %d %d]", x0, x1, x2); tgtidx[0] = x0 + raidz_parity(rm); tgtidx[1] = x1 + raidz_parity(rm); tgtidx[2] = x2 + raidz_parity(rm); corrupt_colums(rm, tgtidx, 3); if (!opts->rto_sanity) vdev_raidz_reconstruct(rm, tgtidx, 3); if (cmp_data(opts, rm) != 0) { err++; LOG(D_DEBUG, "\nREC D[%d %d %d]... " "[FAIL]\n", x0, x1, x2); } } } } } return (err); } static int run_rec_check(raidz_test_opts_t *opts) { char **impl_name; unsigned fn, err = 0; zio_t *zio_test; raidz_map_t *rm_test; err = init_raidz_golden_map(opts, PARITY_PQR); if (0 != err) return (err); LOG(D_INFO, DBLSEP); LOG(D_INFO, "Testing data reconstruction...\n"); for (impl_name = (char **)raidz_impl_names+1; *impl_name != NULL; impl_name++) { LOG(D_INFO, SEP); LOG(D_INFO, "\tTesting [%s] implementation...", *impl_name); if (vdev_raidz_impl_set(*impl_name) != 0) { LOG(D_INFO, "[SKIP]\n"); continue; } else LOG(D_INFO, "[SUPPORTED]\n"); /* create suitable raidz_map */ rm_test = init_raidz_map(opts, &zio_test, PARITY_PQR); /* generate parity */ vdev_raidz_generate_parity(rm_test); for (fn = 0; fn < RAIDZ_REC_NUM; fn++) { LOG(D_INFO, "\t\tTesting method [%s] ...", raidz_rec_name[fn]); if (run_rec_check_impl(opts, rm_test, fn) != 0) { LOG(D_INFO, "[FAIL]\n"); err++; } else LOG(D_INFO, "[PASS]\n"); } /* tear down test raidz_map */ fini_raidz_map(&zio_test, &rm_test); } fini_raidz_map(&opts->zio_golden, &opts->rm_golden); return (err); } static int run_test(raidz_test_opts_t *opts) { int err = 0; if (opts == NULL) opts = &rto_opts; print_opts(opts, B_FALSE); err |= run_gen_check(opts); err |= run_rec_check(opts); return (err); } #define SWEEP_RUNNING 0 #define SWEEP_FINISHED 1 #define SWEEP_ERROR 2 #define SWEEP_TIMEOUT 3 static int sweep_state = 0; static raidz_test_opts_t failed_opts; static kmutex_t sem_mtx; static kcondvar_t sem_cv; static int max_free_slots; static int free_slots; static void sweep_thread(void *arg) { int err = 0; raidz_test_opts_t *opts = (raidz_test_opts_t *)arg; VERIFY(opts != NULL); err = run_test(opts); if (rto_opts.rto_sanity) { /* 25% chance that a sweep test fails */ if (rand() < (RAND_MAX/4)) err = 1; } if (0 != err) { mutex_enter(&sem_mtx); memcpy(&failed_opts, opts, sizeof (raidz_test_opts_t)); sweep_state = SWEEP_ERROR; mutex_exit(&sem_mtx); } umem_free(opts, sizeof (raidz_test_opts_t)); /* signal the next thread */ mutex_enter(&sem_mtx); free_slots++; cv_signal(&sem_cv); mutex_exit(&sem_mtx); thread_exit(); } static int run_sweep(void) { static const size_t dcols_v[] = { 1, 2, 3, 4, 5, 6, 7, 8, 12, 15, 16 }; static const size_t ashift_v[] = { 9, 12, 14 }; static const size_t size_v[] = { 1 << 9, 21 * (1 << 9), 13 * (1 << 12), 1 << 17, (1 << 20) - (1 << 12), SPA_MAXBLOCKSIZE }; (void) setvbuf(stdout, NULL, _IONBF, 0); ulong_t total_comb = ARRAY_SIZE(size_v) * ARRAY_SIZE(ashift_v) * ARRAY_SIZE(dcols_v); ulong_t tried_comb = 0; hrtime_t time_diff, start_time = gethrtime(); raidz_test_opts_t *opts; int a, d, s; max_free_slots = free_slots = MAX(2, boot_ncpus); mutex_init(&sem_mtx, NULL, MUTEX_DEFAULT, NULL); cv_init(&sem_cv, NULL, CV_DEFAULT, NULL); for (s = 0; s < ARRAY_SIZE(size_v); s++) for (a = 0; a < ARRAY_SIZE(ashift_v); a++) for (d = 0; d < ARRAY_SIZE(dcols_v); d++) { if (size_v[s] < (1 << ashift_v[a])) { total_comb--; continue; } if (++tried_comb % 20 == 0) LOG(D_ALL, "%lu/%lu... ", tried_comb, total_comb); /* wait for signal to start new thread */ mutex_enter(&sem_mtx); while (cv_timedwait_sig(&sem_cv, &sem_mtx, ddi_get_lbolt() + hz)) { /* check if should stop the test (timeout) */ time_diff = (gethrtime() - start_time) / NANOSEC; if (rto_opts.rto_sweep_timeout > 0 && time_diff >= rto_opts.rto_sweep_timeout) { sweep_state = SWEEP_TIMEOUT; rto_opts.rto_should_stop = B_TRUE; mutex_exit(&sem_mtx); goto exit; } /* check if should stop the test (error) */ if (sweep_state != SWEEP_RUNNING) { mutex_exit(&sem_mtx); goto exit; } /* exit loop if a slot is available */ if (free_slots > 0) { break; } } free_slots--; mutex_exit(&sem_mtx); opts = umem_zalloc(sizeof (raidz_test_opts_t), UMEM_NOFAIL); opts->rto_ashift = ashift_v[a]; opts->rto_dcols = dcols_v[d]; opts->rto_offset = (1 << ashift_v[a]) * rand(); opts->rto_dsize = size_v[s]; opts->rto_expand = rto_opts.rto_expand; opts->rto_expand_offset = rto_opts.rto_expand_offset; opts->rto_v = 0; /* be quiet */ VERIFY3P(thread_create(NULL, 0, sweep_thread, (void *) opts, 0, NULL, TS_RUN, defclsyspri), !=, NULL); } exit: LOG(D_ALL, "\nWaiting for test threads to finish...\n"); mutex_enter(&sem_mtx); VERIFY(free_slots <= max_free_slots); while (free_slots < max_free_slots) { (void) cv_wait(&sem_cv, &sem_mtx); } mutex_exit(&sem_mtx); if (sweep_state == SWEEP_ERROR) { ERR("Sweep test failed! Failed option: \n"); print_opts(&failed_opts, B_TRUE); } else { if (sweep_state == SWEEP_TIMEOUT) LOG(D_ALL, "Test timeout (%lus). Stopping...\n", (ulong_t)rto_opts.rto_sweep_timeout); LOG(D_ALL, "Sweep test succeeded on %lu raidz maps!\n", (ulong_t)tried_comb); } mutex_destroy(&sem_mtx); return (sweep_state == SWEEP_ERROR ? SWEEP_ERROR : 0); } int main(int argc, char **argv) { size_t i; struct sigaction action; int err = 0; /* init gdb string early */ (void) sprintf(gdb, gdb_tmpl, getpid()); action.sa_handler = sig_handler; sigemptyset(&action.sa_mask); action.sa_flags = 0; if (sigaction(SIGSEGV, &action, NULL) < 0) { ERR("raidz_test: cannot catch SIGSEGV: %s.\n", strerror(errno)); exit(EXIT_FAILURE); } (void) setvbuf(stdout, NULL, _IOLBF, 0); dprintf_setup(&argc, argv); process_options(argc, argv); kernel_init(SPA_MODE_READ); /* setup random data because rand() is not reentrant */ rand_data = (int *)umem_alloc(SPA_MAXBLOCKSIZE, UMEM_NOFAIL); srand((unsigned)time(NULL) * getpid()); for (i = 0; i < SPA_MAXBLOCKSIZE / sizeof (int); i++) rand_data[i] = rand(); mprotect(rand_data, SPA_MAXBLOCKSIZE, PROT_READ); if (rto_opts.rto_benchmark) { run_raidz_benchmark(); } else if (rto_opts.rto_sweep) { err = run_sweep(); } else { err = run_test(NULL); } umem_free(rand_data, SPA_MAXBLOCKSIZE); kernel_fini(); return (err); } diff --git a/include/sys/abd.h b/include/sys/abd.h index 735a13147598..4311076d8a5b 100644 --- a/include/sys/abd.h +++ b/include/sys/abd.h @@ -1,162 +1,219 @@ /* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (c) 2014 by Chunwei Chen. All rights reserved. * Copyright (c) 2016, 2019 by Delphix. All rights reserved. */ #ifndef _ABD_H #define _ABD_H #include #include #include #include #ifdef __cplusplus extern "C" { #endif -struct abd; /* forward declaration */ -typedef struct abd abd_t; +typedef enum abd_flags { + ABD_FLAG_LINEAR = 1 << 0, /* is buffer linear (or scattered)? */ + ABD_FLAG_OWNER = 1 << 1, /* does it own its data buffers? */ + ABD_FLAG_META = 1 << 2, /* does this represent FS metadata? */ + ABD_FLAG_MULTI_ZONE = 1 << 3, /* pages split over memory zones */ + ABD_FLAG_MULTI_CHUNK = 1 << 4, /* pages split over multiple chunks */ + ABD_FLAG_LINEAR_PAGE = 1 << 5, /* linear but allocd from page */ + ABD_FLAG_GANG = 1 << 6, /* mult ABDs chained together */ + ABD_FLAG_GANG_FREE = 1 << 7, /* gang ABD is responsible for mem */ + ABD_FLAG_ZEROS = 1 << 8, /* ABD for zero-filled buffer */ + ABD_FLAG_ALLOCD = 1 << 9, /* we allocated the abd_t */ +} abd_flags_t; + +typedef struct abd { + abd_flags_t abd_flags; + uint_t abd_size; /* excludes scattered abd_offset */ + list_node_t abd_gang_link; + struct abd *abd_parent; + zfs_refcount_t abd_children; + kmutex_t abd_mtx; + union { + struct abd_scatter { + uint_t abd_offset; +#if defined(__FreeBSD__) && defined(_KERNEL) + uint_t abd_chunk_size; + void *abd_chunks[1]; /* actually variable-length */ +#else + uint_t abd_nents; + struct scatterlist *abd_sgl; +#endif + } abd_scatter; + struct abd_linear { + void *abd_buf; + struct scatterlist *abd_sgl; /* for LINEAR_PAGE */ + } abd_linear; + struct abd_gang { + list_t abd_gang_chain; + } abd_gang; + } abd_u; +} abd_t; typedef int abd_iter_func_t(void *buf, size_t len, void *priv); typedef int abd_iter_func2_t(void *bufa, void *bufb, size_t len, void *priv); extern int zfs_abd_scatter_enabled; /* * Allocations and deallocations */ abd_t *abd_alloc(size_t, boolean_t); abd_t *abd_alloc_linear(size_t, boolean_t); -abd_t *abd_alloc_gang_abd(void); +abd_t *abd_alloc_gang(void); abd_t *abd_alloc_for_io(size_t, boolean_t); abd_t *abd_alloc_sametype(abd_t *, size_t); void abd_gang_add(abd_t *, abd_t *, boolean_t); void abd_free(abd_t *); -void abd_put(abd_t *); abd_t *abd_get_offset(abd_t *, size_t); abd_t *abd_get_offset_size(abd_t *, size_t, size_t); +abd_t *abd_get_offset_struct(abd_t *, abd_t *, size_t, size_t); abd_t *abd_get_zeros(size_t); abd_t *abd_get_from_buf(void *, size_t); void abd_cache_reap_now(void); /* * Conversion to and from a normal buffer */ void *abd_to_buf(abd_t *); void *abd_borrow_buf(abd_t *, size_t); void *abd_borrow_buf_copy(abd_t *, size_t); void abd_return_buf(abd_t *, void *, size_t); void abd_return_buf_copy(abd_t *, void *, size_t); void abd_take_ownership_of_buf(abd_t *, boolean_t); void abd_release_ownership_of_buf(abd_t *); /* * ABD operations */ int abd_iterate_func(abd_t *, size_t, size_t, abd_iter_func_t *, void *); int abd_iterate_func2(abd_t *, abd_t *, size_t, size_t, size_t, abd_iter_func2_t *, void *); void abd_copy_off(abd_t *, abd_t *, size_t, size_t, size_t); void abd_copy_from_buf_off(abd_t *, const void *, size_t, size_t); void abd_copy_to_buf_off(void *, abd_t *, size_t, size_t); int abd_cmp(abd_t *, abd_t *); int abd_cmp_buf_off(abd_t *, const void *, size_t, size_t); void abd_zero_off(abd_t *, size_t, size_t); void abd_verify(abd_t *); -uint_t abd_get_size(abd_t *); void abd_raidz_gen_iterate(abd_t **cabds, abd_t *dabd, ssize_t csize, ssize_t dsize, const unsigned parity, void (*func_raidz_gen)(void **, const void *, size_t, size_t)); void abd_raidz_rec_iterate(abd_t **cabds, abd_t **tabds, ssize_t tsize, const unsigned parity, void (*func_raidz_rec)(void **t, const size_t tsize, void **c, const unsigned *mul), const unsigned *mul); /* * Wrappers for calls with offsets of 0 */ static inline void abd_copy(abd_t *dabd, abd_t *sabd, size_t size) { abd_copy_off(dabd, sabd, 0, 0, size); } static inline void abd_copy_from_buf(abd_t *abd, const void *buf, size_t size) { abd_copy_from_buf_off(abd, buf, 0, size); } static inline void abd_copy_to_buf(void* buf, abd_t *abd, size_t size) { abd_copy_to_buf_off(buf, abd, 0, size); } static inline int abd_cmp_buf(abd_t *abd, const void *buf, size_t size) { return (abd_cmp_buf_off(abd, buf, 0, size)); } static inline void abd_zero(abd_t *abd, size_t size) { abd_zero_off(abd, 0, size); } /* * ABD type check functions */ -boolean_t abd_is_linear(abd_t *); -boolean_t abd_is_gang(abd_t *); -boolean_t abd_is_linear_page(abd_t *); +static inline boolean_t +abd_is_linear(abd_t *abd) +{ + return ((abd->abd_flags & ABD_FLAG_LINEAR) != 0); +} + +static inline boolean_t +abd_is_linear_page(abd_t *abd) +{ + return ((abd->abd_flags & ABD_FLAG_LINEAR_PAGE) != 0); +} + +static inline boolean_t +abd_is_gang(abd_t *abd) +{ + return ((abd->abd_flags & ABD_FLAG_GANG) != 0); +} + +static inline uint_t +abd_get_size(abd_t *abd) +{ + return (abd->abd_size); +} /* * Module lifecycle * Defined in each specific OS's abd_os.c */ void abd_init(void); void abd_fini(void); /* * Linux ABD bio functions */ #if defined(__linux__) && defined(_KERNEL) unsigned int abd_bio_map_off(struct bio *, abd_t *, unsigned int, size_t); unsigned long abd_nr_pages_off(abd_t *, unsigned int, size_t); #endif #ifdef __cplusplus } #endif #endif /* _ABD_H */ diff --git a/include/sys/abd_impl.h b/include/sys/abd_impl.h index b1fa87b42a48..435a8dc6d9ce 100644 --- a/include/sys/abd_impl.h +++ b/include/sys/abd_impl.h @@ -1,150 +1,112 @@ /* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (c) 2014 by Chunwei Chen. All rights reserved. * Copyright (c) 2016, 2019 by Delphix. All rights reserved. */ #ifndef _ABD_IMPL_H #define _ABD_IMPL_H #include #ifdef __cplusplus extern "C" { #endif -typedef enum abd_flags { - ABD_FLAG_LINEAR = 1 << 0, /* is buffer linear (or scattered)? */ - ABD_FLAG_OWNER = 1 << 1, /* does it own its data buffers? */ - ABD_FLAG_META = 1 << 2, /* does this represent FS metadata? */ - ABD_FLAG_MULTI_ZONE = 1 << 3, /* pages split over memory zones */ - ABD_FLAG_MULTI_CHUNK = 1 << 4, /* pages split over multiple chunks */ - ABD_FLAG_LINEAR_PAGE = 1 << 5, /* linear but allocd from page */ - ABD_FLAG_GANG = 1 << 6, /* mult ABDs chained together */ - ABD_FLAG_GANG_FREE = 1 << 7, /* gang ABD is responsible for mem */ - ABD_FLAG_ZEROS = 1 << 8, /* ABD for zero-filled buffer */ -} abd_flags_t; - typedef enum abd_stats_op { ABDSTAT_INCR, /* Increase abdstat values */ ABDSTAT_DECR /* Decrease abdstat values */ } abd_stats_op_t; -struct abd { - abd_flags_t abd_flags; - uint_t abd_size; /* excludes scattered abd_offset */ - list_node_t abd_gang_link; - struct abd *abd_parent; - zfs_refcount_t abd_children; - kmutex_t abd_mtx; - union { - struct abd_scatter { - uint_t abd_offset; -#if defined(__FreeBSD__) && defined(_KERNEL) - uint_t abd_chunk_size; - void *abd_chunks[]; -#else - uint_t abd_nents; - struct scatterlist *abd_sgl; -#endif - } abd_scatter; - struct abd_linear { - void *abd_buf; - struct scatterlist *abd_sgl; /* for LINEAR_PAGE */ - } abd_linear; - struct abd_gang { - list_t abd_gang_chain; - } abd_gang; - } abd_u; -}; - struct scatterlist; /* forward declaration */ struct abd_iter { /* public interface */ void *iter_mapaddr; /* addr corresponding to iter_pos */ size_t iter_mapsize; /* length of data valid at mapaddr */ /* private */ abd_t *iter_abd; /* ABD being iterated through */ size_t iter_pos; size_t iter_offset; /* offset in current sg/abd_buf, */ /* abd_offset included */ struct scatterlist *iter_sg; /* current sg */ }; extern abd_t *abd_zero_scatter; abd_t *abd_gang_get_offset(abd_t *, size_t *); +abd_t *abd_alloc_struct(size_t); +void abd_free_struct(abd_t *); /* * OS specific functions */ -abd_t *abd_alloc_struct(size_t); -abd_t *abd_get_offset_scatter(abd_t *, size_t); -void abd_free_struct(abd_t *); +abd_t *abd_alloc_struct_impl(size_t); +abd_t *abd_get_offset_scatter(abd_t *, abd_t *, size_t); +void abd_free_struct_impl(abd_t *); void abd_alloc_chunks(abd_t *, size_t); void abd_free_chunks(abd_t *); boolean_t abd_size_alloc_linear(size_t); void abd_update_scatter_stats(abd_t *, abd_stats_op_t); void abd_update_linear_stats(abd_t *, abd_stats_op_t); void abd_verify_scatter(abd_t *); void abd_free_linear_page(abd_t *); /* OS specific abd_iter functions */ void abd_iter_init(struct abd_iter *, abd_t *); boolean_t abd_iter_at_end(struct abd_iter *); void abd_iter_advance(struct abd_iter *, size_t); void abd_iter_map(struct abd_iter *); void abd_iter_unmap(struct abd_iter *); /* * Helper macros */ #define ABDSTAT(stat) (abd_stats.stat.value.ui64) #define ABDSTAT_INCR(stat, val) \ atomic_add_64(&abd_stats.stat.value.ui64, (val)) #define ABDSTAT_BUMP(stat) ABDSTAT_INCR(stat, 1) #define ABDSTAT_BUMPDOWN(stat) ABDSTAT_INCR(stat, -1) #define ABD_SCATTER(abd) (abd->abd_u.abd_scatter) #define ABD_LINEAR_BUF(abd) (abd->abd_u.abd_linear.abd_buf) #define ABD_GANG(abd) (abd->abd_u.abd_gang) #if defined(_KERNEL) #if defined(__FreeBSD__) #define abd_enter_critical(flags) critical_enter() #define abd_exit_critical(flags) critical_exit() #else #define abd_enter_critical(flags) local_irq_save(flags) #define abd_exit_critical(flags) local_irq_restore(flags) #endif #else /* !_KERNEL */ #define abd_enter_critical(flags) ((void)0) #define abd_exit_critical(flags) ((void)0) #endif #ifdef __cplusplus } #endif #endif /* _ABD_IMPL_H */ diff --git a/include/sys/vdev_raidz_impl.h b/include/sys/vdev_raidz_impl.h index 38d4f9e0bd48..c869b8b4d52c 100644 --- a/include/sys/vdev_raidz_impl.h +++ b/include/sys/vdev_raidz_impl.h @@ -1,392 +1,393 @@ /* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (C) 2016 Gvozden Nešković. All rights reserved. */ #ifndef _VDEV_RAIDZ_H #define _VDEV_RAIDZ_H #include #include #include #include #include #ifdef __cplusplus extern "C" { #endif #define CODE_P (0U) #define CODE_Q (1U) #define CODE_R (2U) #define PARITY_P (1U) #define PARITY_PQ (2U) #define PARITY_PQR (3U) #define TARGET_X (0U) #define TARGET_Y (1U) #define TARGET_Z (2U) /* * Parity generation methods indexes */ enum raidz_math_gen_op { RAIDZ_GEN_P = 0, RAIDZ_GEN_PQ, RAIDZ_GEN_PQR, RAIDZ_GEN_NUM = 3 }; /* * Data reconstruction methods indexes */ enum raidz_rec_op { RAIDZ_REC_P = 0, RAIDZ_REC_Q, RAIDZ_REC_R, RAIDZ_REC_PQ, RAIDZ_REC_PR, RAIDZ_REC_QR, RAIDZ_REC_PQR, RAIDZ_REC_NUM = 7 }; extern const char *raidz_gen_name[RAIDZ_GEN_NUM]; extern const char *raidz_rec_name[RAIDZ_REC_NUM]; /* * Methods used to define raidz implementation * * @raidz_gen_f Parity generation function * @par1 pointer to raidz_map * @raidz_rec_f Data reconstruction function * @par1 pointer to raidz_map * @par2 array of reconstruction targets * @will_work_f Function returns TRUE if impl. is supported on the system * @init_impl_f Function is called once on init * @fini_impl_f Function is called once on fini */ typedef void (*raidz_gen_f)(void *); typedef int (*raidz_rec_f)(void *, const int *); typedef boolean_t (*will_work_f)(void); typedef void (*init_impl_f)(void); typedef void (*fini_impl_f)(void); #define RAIDZ_IMPL_NAME_MAX (20) typedef struct raidz_impl_ops { init_impl_f init; fini_impl_f fini; raidz_gen_f gen[RAIDZ_GEN_NUM]; /* Parity generate functions */ raidz_rec_f rec[RAIDZ_REC_NUM]; /* Data reconstruction functions */ will_work_f is_supported; /* Support check function */ char name[RAIDZ_IMPL_NAME_MAX]; /* Name of the implementation */ } raidz_impl_ops_t; typedef struct raidz_col { uint64_t rc_devidx; /* child device index for I/O */ uint64_t rc_offset; /* device offset */ uint64_t rc_size; /* I/O size */ + abd_t rc_abdstruct; /* rc_abd probably points here */ abd_t *rc_abd; /* I/O data */ void *rc_orig_data; /* pre-reconstruction */ abd_t *rc_gdata; /* used to store the "good" version */ int rc_error; /* I/O error for this device */ uint8_t rc_tried; /* Did we attempt this I/O column? */ uint8_t rc_skipped; /* Did we skip this I/O column? */ uint8_t rc_need_orig_restore; /* need to restore from orig_data? */ uint8_t rc_repair; /* Write good data to this column */ } raidz_col_t; typedef struct raidz_row { uint64_t rr_cols; /* Regular column count */ uint64_t rr_scols; /* Count including skipped columns */ uint64_t rr_bigcols; /* Remainder data column count */ uint64_t rr_missingdata; /* Count of missing data devices */ uint64_t rr_missingparity; /* Count of missing parity devices */ uint64_t rr_firstdatacol; /* First data column/parity count */ abd_t *rr_abd_copy; /* rm_asize-buffer of copied data */ abd_t *rr_abd_empty; /* dRAID empty sector buffer */ int rr_nempty; /* empty sectors included in parity */ int rr_code; /* reconstruction code (unused) */ #ifdef ZFS_DEBUG uint64_t rr_offset; /* Logical offset for *_io_verify() */ uint64_t rr_size; /* Physical size for *_io_verify() */ #endif raidz_col_t rr_col[0]; /* Flexible array of I/O columns */ } raidz_row_t; typedef struct raidz_map { uintptr_t rm_reports; /* # of referencing checksum reports */ boolean_t rm_freed; /* map no longer has referencing ZIO */ boolean_t rm_ecksuminjected; /* checksum error was injected */ int rm_nrows; /* Regular row count */ int rm_nskip; /* RAIDZ sectors skipped for padding */ int rm_skipstart; /* Column index of padding start */ const raidz_impl_ops_t *rm_ops; /* RAIDZ math operations */ raidz_row_t *rm_row[0]; /* flexible array of rows */ } raidz_map_t; #define RAIDZ_ORIGINAL_IMPL (INT_MAX) extern const raidz_impl_ops_t vdev_raidz_scalar_impl; extern boolean_t raidz_will_scalar_work(void); #if defined(__x86_64) && defined(HAVE_SSE2) /* only x86_64 for now */ extern const raidz_impl_ops_t vdev_raidz_sse2_impl; #endif #if defined(__x86_64) && defined(HAVE_SSSE3) /* only x86_64 for now */ extern const raidz_impl_ops_t vdev_raidz_ssse3_impl; #endif #if defined(__x86_64) && defined(HAVE_AVX2) /* only x86_64 for now */ extern const raidz_impl_ops_t vdev_raidz_avx2_impl; #endif #if defined(__x86_64) && defined(HAVE_AVX512F) /* only x86_64 for now */ extern const raidz_impl_ops_t vdev_raidz_avx512f_impl; #endif #if defined(__x86_64) && defined(HAVE_AVX512BW) /* only x86_64 for now */ extern const raidz_impl_ops_t vdev_raidz_avx512bw_impl; #endif #if defined(__aarch64__) extern const raidz_impl_ops_t vdev_raidz_aarch64_neon_impl; extern const raidz_impl_ops_t vdev_raidz_aarch64_neonx2_impl; #endif #if defined(__powerpc__) extern const raidz_impl_ops_t vdev_raidz_powerpc_altivec_impl; #endif /* * Commonly used raidz_map helpers * * raidz_parity Returns parity of the RAIDZ block * raidz_ncols Returns number of columns the block spans * Note, all rows have the same number of columns. * raidz_nbigcols Returns number of big columns * raidz_col_p Returns pointer to a column * raidz_col_size Returns size of a column * raidz_big_size Returns size of big columns * raidz_short_size Returns size of short columns */ #define raidz_parity(rm) ((rm)->rm_row[0]->rr_firstdatacol) #define raidz_ncols(rm) ((rm)->rm_row[0]->rr_cols) #define raidz_nbigcols(rm) ((rm)->rm_bigcols) #define raidz_col_p(rm, c) ((rm)->rm_col + (c)) #define raidz_col_size(rm, c) ((rm)->rm_col[c].rc_size) #define raidz_big_size(rm) (raidz_col_size(rm, CODE_P)) #define raidz_short_size(rm) (raidz_col_size(rm, raidz_ncols(rm)-1)) /* * Macro defines an RAIDZ parity generation method * * @code parity the function produce * @impl name of the implementation */ #define _RAIDZ_GEN_WRAP(code, impl) \ static void \ impl ## _gen_ ## code(void *rrp) \ { \ raidz_row_t *rr = (raidz_row_t *)rrp; \ raidz_generate_## code ## _impl(rr); \ } /* * Macro defines an RAIDZ data reconstruction method * * @code parity the function produce * @impl name of the implementation */ #define _RAIDZ_REC_WRAP(code, impl) \ static int \ impl ## _rec_ ## code(void *rrp, const int *tgtidx) \ { \ raidz_row_t *rr = (raidz_row_t *)rrp; \ return (raidz_reconstruct_## code ## _impl(rr, tgtidx)); \ } /* * Define all gen methods for an implementation * * @impl name of the implementation */ #define DEFINE_GEN_METHODS(impl) \ _RAIDZ_GEN_WRAP(p, impl); \ _RAIDZ_GEN_WRAP(pq, impl); \ _RAIDZ_GEN_WRAP(pqr, impl) /* * Define all rec functions for an implementation * * @impl name of the implementation */ #define DEFINE_REC_METHODS(impl) \ _RAIDZ_REC_WRAP(p, impl); \ _RAIDZ_REC_WRAP(q, impl); \ _RAIDZ_REC_WRAP(r, impl); \ _RAIDZ_REC_WRAP(pq, impl); \ _RAIDZ_REC_WRAP(pr, impl); \ _RAIDZ_REC_WRAP(qr, impl); \ _RAIDZ_REC_WRAP(pqr, impl) #define RAIDZ_GEN_METHODS(impl) \ { \ [RAIDZ_GEN_P] = & impl ## _gen_p, \ [RAIDZ_GEN_PQ] = & impl ## _gen_pq, \ [RAIDZ_GEN_PQR] = & impl ## _gen_pqr \ } #define RAIDZ_REC_METHODS(impl) \ { \ [RAIDZ_REC_P] = & impl ## _rec_p, \ [RAIDZ_REC_Q] = & impl ## _rec_q, \ [RAIDZ_REC_R] = & impl ## _rec_r, \ [RAIDZ_REC_PQ] = & impl ## _rec_pq, \ [RAIDZ_REC_PR] = & impl ## _rec_pr, \ [RAIDZ_REC_QR] = & impl ## _rec_qr, \ [RAIDZ_REC_PQR] = & impl ## _rec_pqr \ } typedef struct raidz_impl_kstat { uint64_t gen[RAIDZ_GEN_NUM]; /* gen method speed B/s */ uint64_t rec[RAIDZ_REC_NUM]; /* rec method speed B/s */ } raidz_impl_kstat_t; /* * Enumerate various multiplication constants * used in reconstruction methods */ typedef enum raidz_mul_info { /* Reconstruct Q */ MUL_Q_X = 0, /* Reconstruct R */ MUL_R_X = 0, /* Reconstruct PQ */ MUL_PQ_X = 0, MUL_PQ_Y = 1, /* Reconstruct PR */ MUL_PR_X = 0, MUL_PR_Y = 1, /* Reconstruct QR */ MUL_QR_XQ = 0, MUL_QR_X = 1, MUL_QR_YQ = 2, MUL_QR_Y = 3, /* Reconstruct PQR */ MUL_PQR_XP = 0, MUL_PQR_XQ = 1, MUL_PQR_XR = 2, MUL_PQR_YU = 3, MUL_PQR_YP = 4, MUL_PQR_YQ = 5, MUL_CNT = 6 } raidz_mul_info_t; /* * Powers of 2 in the Galois field. */ extern const uint8_t vdev_raidz_pow2[256] __attribute__((aligned(256))); /* Logs of 2 in the Galois field defined above. */ extern const uint8_t vdev_raidz_log2[256] __attribute__((aligned(256))); /* * Multiply a given number by 2 raised to the given power. */ static inline uint8_t vdev_raidz_exp2(const uint8_t a, const unsigned exp) { if (a == 0) return (0); return (vdev_raidz_pow2[(exp + (unsigned)vdev_raidz_log2[a]) % 255]); } /* * Galois Field operations. * * gf_exp2 - computes 2 raised to the given power * gf_exp2 - computes 4 raised to the given power * gf_mul - multiplication * gf_div - division * gf_inv - multiplicative inverse */ typedef unsigned gf_t; typedef unsigned gf_log_t; static inline gf_t gf_mul(const gf_t a, const gf_t b) { gf_log_t logsum; if (a == 0 || b == 0) return (0); logsum = (gf_log_t)vdev_raidz_log2[a] + (gf_log_t)vdev_raidz_log2[b]; return ((gf_t)vdev_raidz_pow2[logsum % 255]); } static inline gf_t gf_div(const gf_t a, const gf_t b) { gf_log_t logsum; ASSERT3U(b, >, 0); if (a == 0) return (0); logsum = (gf_log_t)255 + (gf_log_t)vdev_raidz_log2[a] - (gf_log_t)vdev_raidz_log2[b]; return ((gf_t)vdev_raidz_pow2[logsum % 255]); } static inline gf_t gf_inv(const gf_t a) { gf_log_t logsum; ASSERT3U(a, >, 0); logsum = (gf_log_t)255 - (gf_log_t)vdev_raidz_log2[a]; return ((gf_t)vdev_raidz_pow2[logsum]); } static inline gf_t gf_exp2(gf_log_t exp) { return (vdev_raidz_pow2[exp % 255]); } static inline gf_t gf_exp4(gf_log_t exp) { ASSERT3U(exp, <=, 255); return ((gf_t)vdev_raidz_pow2[(2 * exp) % 255]); } #ifdef __cplusplus } #endif #endif /* _VDEV_RAIDZ_H */ diff --git a/module/os/freebsd/zfs/abd_os.c b/module/os/freebsd/zfs/abd_os.c index 0a323e8856a3..ab82b2aaeb78 100644 --- a/module/os/freebsd/zfs/abd_os.c +++ b/module/os/freebsd/zfs/abd_os.c @@ -1,505 +1,506 @@ /* * This file and its contents are supplied under the terms of the * Common Development and Distribution License ("CDDL"), version 1.0. * You may only use this file in accordance with the terms of version * 1.0 of the CDDL. * * A full copy of the text of the CDDL should have accompanied this * source. A copy of the CDDL is also available via the Internet at * http://www.illumos.org/license/CDDL. */ /* * Copyright (c) 2014 by Chunwei Chen. All rights reserved. * Copyright (c) 2016 by Delphix. All rights reserved. */ /* * See abd.c for a general overview of the arc buffered data (ABD). * * Using a large proportion of scattered ABDs decreases ARC fragmentation since * when we are at the limit of allocatable space, using equal-size chunks will * allow us to quickly reclaim enough space for a new large allocation (assuming * it is also scattered). * * ABDs are allocated scattered by default unless the caller uses * abd_alloc_linear() or zfs_abd_scatter_enabled is disabled. */ #include #include #include #include #include #include typedef struct abd_stats { kstat_named_t abdstat_struct_size; kstat_named_t abdstat_scatter_cnt; kstat_named_t abdstat_scatter_data_size; kstat_named_t abdstat_scatter_chunk_waste; kstat_named_t abdstat_linear_cnt; kstat_named_t abdstat_linear_data_size; } abd_stats_t; static abd_stats_t abd_stats = { /* Amount of memory occupied by all of the abd_t struct allocations */ { "struct_size", KSTAT_DATA_UINT64 }, /* * The number of scatter ABDs which are currently allocated, excluding * ABDs which don't own their data (for instance the ones which were * allocated through abd_get_offset()). */ { "scatter_cnt", KSTAT_DATA_UINT64 }, /* Amount of data stored in all scatter ABDs tracked by scatter_cnt */ { "scatter_data_size", KSTAT_DATA_UINT64 }, /* * The amount of space wasted at the end of the last chunk across all * scatter ABDs tracked by scatter_cnt. */ { "scatter_chunk_waste", KSTAT_DATA_UINT64 }, /* * The number of linear ABDs which are currently allocated, excluding * ABDs which don't own their data (for instance the ones which were * allocated through abd_get_offset() and abd_get_from_buf()). If an * ABD takes ownership of its buf then it will become tracked. */ { "linear_cnt", KSTAT_DATA_UINT64 }, /* Amount of data stored in all linear ABDs tracked by linear_cnt */ { "linear_data_size", KSTAT_DATA_UINT64 }, }; /* * The size of the chunks ABD allocates. Because the sizes allocated from the * kmem_cache can't change, this tunable can only be modified at boot. Changing * it at runtime would cause ABD iteration to work incorrectly for ABDs which * were allocated with the old size, so a safeguard has been put in place which * will cause the machine to panic if you change it and try to access the data * within a scattered ABD. */ size_t zfs_abd_chunk_size = 4096; #if defined(_KERNEL) SYSCTL_DECL(_vfs_zfs); SYSCTL_INT(_vfs_zfs, OID_AUTO, abd_scatter_enabled, CTLFLAG_RWTUN, &zfs_abd_scatter_enabled, 0, "Enable scattered ARC data buffers"); SYSCTL_ULONG(_vfs_zfs, OID_AUTO, abd_chunk_size, CTLFLAG_RDTUN, &zfs_abd_chunk_size, 0, "The size of the chunks ABD allocates"); #endif kmem_cache_t *abd_chunk_cache; static kstat_t *abd_ksp; /* * We use a scattered SPA_MAXBLOCKSIZE sized ABD whose chunks are * just a single zero'd sized zfs_abd_chunk_size buffer. This * allows us to conserve memory by only using a single zero buffer * for the scatter chunks. */ abd_t *abd_zero_scatter = NULL; static char *abd_zero_buf = NULL; static void abd_free_chunk(void *c) { kmem_cache_free(abd_chunk_cache, c); } static uint_t abd_chunkcnt_for_bytes(size_t size) { return (P2ROUNDUP(size, zfs_abd_chunk_size) / zfs_abd_chunk_size); } static inline uint_t abd_scatter_chunkcnt(abd_t *abd) { ASSERT(!abd_is_linear(abd)); return (abd_chunkcnt_for_bytes( ABD_SCATTER(abd).abd_offset + abd->abd_size)); } boolean_t abd_size_alloc_linear(size_t size) { return (size <= zfs_abd_chunk_size ? B_TRUE : B_FALSE); } void abd_update_scatter_stats(abd_t *abd, abd_stats_op_t op) { uint_t n = abd_scatter_chunkcnt(abd); ASSERT(op == ABDSTAT_INCR || op == ABDSTAT_DECR); int waste = n * zfs_abd_chunk_size - abd->abd_size; if (op == ABDSTAT_INCR) { ABDSTAT_BUMP(abdstat_scatter_cnt); ABDSTAT_INCR(abdstat_scatter_data_size, abd->abd_size); ABDSTAT_INCR(abdstat_scatter_chunk_waste, waste); arc_space_consume(waste, ARC_SPACE_ABD_CHUNK_WASTE); } else { ABDSTAT_BUMPDOWN(abdstat_scatter_cnt); ABDSTAT_INCR(abdstat_scatter_data_size, -(int)abd->abd_size); ABDSTAT_INCR(abdstat_scatter_chunk_waste, -waste); arc_space_return(waste, ARC_SPACE_ABD_CHUNK_WASTE); } } void abd_update_linear_stats(abd_t *abd, abd_stats_op_t op) { ASSERT(op == ABDSTAT_INCR || op == ABDSTAT_DECR); if (op == ABDSTAT_INCR) { ABDSTAT_BUMP(abdstat_linear_cnt); ABDSTAT_INCR(abdstat_linear_data_size, abd->abd_size); } else { ABDSTAT_BUMPDOWN(abdstat_linear_cnt); ABDSTAT_INCR(abdstat_linear_data_size, -(int)abd->abd_size); } } void abd_verify_scatter(abd_t *abd) { uint_t i, n; /* * There is no scatter linear pages in FreeBSD so there is an * if an error if the ABD has been marked as a linear page. */ ASSERT(!abd_is_linear_page(abd)); ASSERT3U(ABD_SCATTER(abd).abd_offset, <, zfs_abd_chunk_size); n = abd_scatter_chunkcnt(abd); for (i = 0; i < n; i++) { ASSERT3P(ABD_SCATTER(abd).abd_chunks[i], !=, NULL); } } void abd_alloc_chunks(abd_t *abd, size_t size) { uint_t i, n; n = abd_chunkcnt_for_bytes(size); for (i = 0; i < n; i++) { void *c = kmem_cache_alloc(abd_chunk_cache, KM_PUSHPAGE); ASSERT3P(c, !=, NULL); ABD_SCATTER(abd).abd_chunks[i] = c; } ABD_SCATTER(abd).abd_chunk_size = zfs_abd_chunk_size; } void abd_free_chunks(abd_t *abd) { uint_t i, n; n = abd_scatter_chunkcnt(abd); for (i = 0; i < n; i++) { abd_free_chunk(ABD_SCATTER(abd).abd_chunks[i]); } } abd_t * -abd_alloc_struct(size_t size) +abd_alloc_struct_impl(size_t size) { uint_t chunkcnt = abd_chunkcnt_for_bytes(size); /* * In the event we are allocating a gang ABD, the size passed in * will be 0. We must make sure to set abd_size to the size of an * ABD struct as opposed to an ABD scatter with 0 chunks. The gang * ABD struct allocation accounts for an additional 24 bytes over * a scatter ABD with 0 chunks. */ size_t abd_size = MAX(sizeof (abd_t), offsetof(abd_t, abd_u.abd_scatter.abd_chunks[chunkcnt])); abd_t *abd = kmem_alloc(abd_size, KM_PUSHPAGE); ASSERT3P(abd, !=, NULL); - list_link_init(&abd->abd_gang_link); - mutex_init(&abd->abd_mtx, NULL, MUTEX_DEFAULT, NULL); ABDSTAT_INCR(abdstat_struct_size, abd_size); return (abd); } void -abd_free_struct(abd_t *abd) +abd_free_struct_impl(abd_t *abd) { uint_t chunkcnt = abd_is_linear(abd) || abd_is_gang(abd) ? 0 : abd_scatter_chunkcnt(abd); ssize_t size = MAX(sizeof (abd_t), offsetof(abd_t, abd_u.abd_scatter.abd_chunks[chunkcnt])); - mutex_destroy(&abd->abd_mtx); - ASSERT(!list_link_active(&abd->abd_gang_link)); kmem_free(abd, size); ABDSTAT_INCR(abdstat_struct_size, -size); } /* * Allocate scatter ABD of size SPA_MAXBLOCKSIZE, where * each chunk in the scatterlist will be set to abd_zero_buf. */ static void abd_alloc_zero_scatter(void) { uint_t i, n; n = abd_chunkcnt_for_bytes(SPA_MAXBLOCKSIZE); abd_zero_buf = kmem_zalloc(zfs_abd_chunk_size, KM_SLEEP); abd_zero_scatter = abd_alloc_struct(SPA_MAXBLOCKSIZE); - abd_zero_scatter->abd_flags = ABD_FLAG_OWNER | ABD_FLAG_ZEROS; + abd_zero_scatter->abd_flags |= ABD_FLAG_OWNER | ABD_FLAG_ZEROS; abd_zero_scatter->abd_size = SPA_MAXBLOCKSIZE; - abd_zero_scatter->abd_parent = NULL; - zfs_refcount_create(&abd_zero_scatter->abd_children); ABD_SCATTER(abd_zero_scatter).abd_offset = 0; ABD_SCATTER(abd_zero_scatter).abd_chunk_size = zfs_abd_chunk_size; for (i = 0; i < n; i++) { ABD_SCATTER(abd_zero_scatter).abd_chunks[i] = abd_zero_buf; } ABDSTAT_BUMP(abdstat_scatter_cnt); ABDSTAT_INCR(abdstat_scatter_data_size, zfs_abd_chunk_size); } static void abd_free_zero_scatter(void) { - zfs_refcount_destroy(&abd_zero_scatter->abd_children); ABDSTAT_BUMPDOWN(abdstat_scatter_cnt); ABDSTAT_INCR(abdstat_scatter_data_size, -(int)zfs_abd_chunk_size); abd_free_struct(abd_zero_scatter); abd_zero_scatter = NULL; kmem_free(abd_zero_buf, zfs_abd_chunk_size); } void abd_init(void) { abd_chunk_cache = kmem_cache_create("abd_chunk", zfs_abd_chunk_size, 0, NULL, NULL, NULL, NULL, 0, KMC_NODEBUG); abd_ksp = kstat_create("zfs", 0, "abdstats", "misc", KSTAT_TYPE_NAMED, sizeof (abd_stats) / sizeof (kstat_named_t), KSTAT_FLAG_VIRTUAL); if (abd_ksp != NULL) { abd_ksp->ks_data = &abd_stats; kstat_install(abd_ksp); } abd_alloc_zero_scatter(); } void abd_fini(void) { abd_free_zero_scatter(); if (abd_ksp != NULL) { kstat_delete(abd_ksp); abd_ksp = NULL; } kmem_cache_destroy(abd_chunk_cache); abd_chunk_cache = NULL; } void abd_free_linear_page(abd_t *abd) { /* * FreeBSD does not have have scatter linear pages * so there is an error. */ VERIFY(0); } /* * If we're going to use this ABD for doing I/O using the block layer, the * consumer of the ABD data doesn't care if it's scattered or not, and we don't * plan to store this ABD in memory for a long period of time, we should * allocate the ABD type that requires the least data copying to do the I/O. * * Currently this is linear ABDs, however if ldi_strategy() can ever issue I/Os * using a scatter/gather list we should switch to that and replace this call * with vanilla abd_alloc(). */ abd_t * abd_alloc_for_io(size_t size, boolean_t is_metadata) { return (abd_alloc_linear(size, is_metadata)); } /* * This is just a helper function to abd_get_offset_scatter() to alloc a * scatter ABD using the calculated chunkcnt based on the offset within the * parent ABD. */ static abd_t * abd_alloc_scatter_offset_chunkcnt(size_t chunkcnt) { size_t abd_size = offsetof(abd_t, abd_u.abd_scatter.abd_chunks[chunkcnt]); abd_t *abd = kmem_alloc(abd_size, KM_PUSHPAGE); ASSERT3P(abd, !=, NULL); list_link_init(&abd->abd_gang_link); mutex_init(&abd->abd_mtx, NULL, MUTEX_DEFAULT, NULL); ABDSTAT_INCR(abdstat_struct_size, abd_size); return (abd); } abd_t * -abd_get_offset_scatter(abd_t *sabd, size_t off) +abd_get_offset_scatter(abd_t *abd, abd_t *sabd, size_t off) { - abd_t *abd = NULL; - abd_verify(sabd); ASSERT3U(off, <=, sabd->abd_size); size_t new_offset = ABD_SCATTER(sabd).abd_offset + off; uint_t chunkcnt = abd_scatter_chunkcnt(sabd) - (new_offset / zfs_abd_chunk_size); - abd = abd_alloc_scatter_offset_chunkcnt(chunkcnt); + /* + * If an abd struct is provided, it is only the minimum size. If we + * need additional chunks, we need to allocate a new struct. + */ + if (abd != NULL && + offsetof(abd_t, abd_u.abd_scatter.abd_chunks[chunkcnt]) > + sizeof (abd_t)) { + abd = NULL; + } + + if (abd == NULL) + abd = abd_alloc_struct(chunkcnt * zfs_abd_chunk_size); /* * Even if this buf is filesystem metadata, we only track that * if we own the underlying data buffer, which is not true in * this case. Therefore, we don't ever use ABD_FLAG_META here. */ - abd->abd_flags = 0; ABD_SCATTER(abd).abd_offset = new_offset % zfs_abd_chunk_size; ABD_SCATTER(abd).abd_chunk_size = zfs_abd_chunk_size; /* Copy the scatterlist starting at the correct offset */ (void) memcpy(&ABD_SCATTER(abd).abd_chunks, &ABD_SCATTER(sabd).abd_chunks[new_offset / zfs_abd_chunk_size], chunkcnt * sizeof (void *)); return (abd); } static inline size_t abd_iter_scatter_chunk_offset(struct abd_iter *aiter) { ASSERT(!abd_is_linear(aiter->iter_abd)); return ((ABD_SCATTER(aiter->iter_abd).abd_offset + aiter->iter_pos) % zfs_abd_chunk_size); } static inline size_t abd_iter_scatter_chunk_index(struct abd_iter *aiter) { ASSERT(!abd_is_linear(aiter->iter_abd)); return ((ABD_SCATTER(aiter->iter_abd).abd_offset + aiter->iter_pos) / zfs_abd_chunk_size); } /* * Initialize the abd_iter. */ void abd_iter_init(struct abd_iter *aiter, abd_t *abd) { ASSERT(!abd_is_gang(abd)); abd_verify(abd); aiter->iter_abd = abd; aiter->iter_pos = 0; aiter->iter_mapaddr = NULL; aiter->iter_mapsize = 0; } /* * This is just a helper function to see if we have exhausted the * abd_iter and reached the end. */ boolean_t abd_iter_at_end(struct abd_iter *aiter) { return (aiter->iter_pos == aiter->iter_abd->abd_size); } /* * Advance the iterator by a certain amount. Cannot be called when a chunk is * in use. This can be safely called when the aiter has already exhausted, in * which case this does nothing. */ void abd_iter_advance(struct abd_iter *aiter, size_t amount) { ASSERT3P(aiter->iter_mapaddr, ==, NULL); ASSERT0(aiter->iter_mapsize); /* There's nothing left to advance to, so do nothing */ if (abd_iter_at_end(aiter)) return; aiter->iter_pos += amount; } /* * Map the current chunk into aiter. This can be safely called when the aiter * has already exhausted, in which case this does nothing. */ void abd_iter_map(struct abd_iter *aiter) { void *paddr; size_t offset = 0; ASSERT3P(aiter->iter_mapaddr, ==, NULL); ASSERT0(aiter->iter_mapsize); /* Panic if someone has changed zfs_abd_chunk_size */ IMPLY(!abd_is_linear(aiter->iter_abd), zfs_abd_chunk_size == ABD_SCATTER(aiter->iter_abd).abd_chunk_size); /* There's nothing left to iterate over, so do nothing */ if (abd_iter_at_end(aiter)) return; if (abd_is_linear(aiter->iter_abd)) { offset = aiter->iter_pos; aiter->iter_mapsize = aiter->iter_abd->abd_size - offset; paddr = ABD_LINEAR_BUF(aiter->iter_abd); } else { size_t index = abd_iter_scatter_chunk_index(aiter); offset = abd_iter_scatter_chunk_offset(aiter); aiter->iter_mapsize = MIN(zfs_abd_chunk_size - offset, aiter->iter_abd->abd_size - aiter->iter_pos); paddr = ABD_SCATTER(aiter->iter_abd).abd_chunks[index]; } aiter->iter_mapaddr = (char *)paddr + offset; } /* * Unmap the current chunk from aiter. This can be safely called when the aiter * has already exhausted, in which case this does nothing. */ void abd_iter_unmap(struct abd_iter *aiter) { /* There's nothing left to unmap, so do nothing */ if (abd_iter_at_end(aiter)) return; ASSERT3P(aiter->iter_mapaddr, !=, NULL); ASSERT3U(aiter->iter_mapsize, >, 0); aiter->iter_mapaddr = NULL; aiter->iter_mapsize = 0; } void abd_cache_reap_now(void) { kmem_cache_reap_soon(abd_chunk_cache); } diff --git a/module/os/linux/zfs/abd_os.c b/module/os/linux/zfs/abd_os.c index 0abac228447f..352d14de120e 100644 --- a/module/os/linux/zfs/abd_os.c +++ b/module/os/linux/zfs/abd_os.c @@ -1,1074 +1,1063 @@ /* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (c) 2014 by Chunwei Chen. All rights reserved. * Copyright (c) 2019 by Delphix. All rights reserved. */ /* * See abd.c for a general overview of the arc buffered data (ABD). * * Linear buffers act exactly like normal buffers and are always mapped into the * kernel's virtual memory space, while scattered ABD data chunks are allocated * as physical pages and then mapped in only while they are actually being * accessed through one of the abd_* library functions. Using scattered ABDs * provides several benefits: * * (1) They avoid use of kmem_*, preventing performance problems where running * kmem_reap on very large memory systems never finishes and causes * constant TLB shootdowns. * * (2) Fragmentation is less of an issue since when we are at the limit of * allocatable space, we won't have to search around for a long free * hole in the VA space for large ARC allocations. Each chunk is mapped in * individually, so even if we are using HIGHMEM (see next point) we * wouldn't need to worry about finding a contiguous address range. * * (3) If we are not using HIGHMEM, then all physical memory is always * mapped into the kernel's address space, so we also avoid the map / * unmap costs on each ABD access. * * If we are not using HIGHMEM, scattered buffers which have only one chunk * can be treated as linear buffers, because they are contiguous in the * kernel's virtual address space. See abd_alloc_chunks() for details. */ #include #include #include #include #include #include #ifdef _KERNEL #include #include #else #define MAX_ORDER 1 #endif typedef struct abd_stats { kstat_named_t abdstat_struct_size; kstat_named_t abdstat_linear_cnt; kstat_named_t abdstat_linear_data_size; kstat_named_t abdstat_scatter_cnt; kstat_named_t abdstat_scatter_data_size; kstat_named_t abdstat_scatter_chunk_waste; kstat_named_t abdstat_scatter_orders[MAX_ORDER]; kstat_named_t abdstat_scatter_page_multi_chunk; kstat_named_t abdstat_scatter_page_multi_zone; kstat_named_t abdstat_scatter_page_alloc_retry; kstat_named_t abdstat_scatter_sg_table_retry; } abd_stats_t; static abd_stats_t abd_stats = { /* Amount of memory occupied by all of the abd_t struct allocations */ { "struct_size", KSTAT_DATA_UINT64 }, /* * The number of linear ABDs which are currently allocated, excluding * ABDs which don't own their data (for instance the ones which were * allocated through abd_get_offset() and abd_get_from_buf()). If an * ABD takes ownership of its buf then it will become tracked. */ { "linear_cnt", KSTAT_DATA_UINT64 }, /* Amount of data stored in all linear ABDs tracked by linear_cnt */ { "linear_data_size", KSTAT_DATA_UINT64 }, /* * The number of scatter ABDs which are currently allocated, excluding * ABDs which don't own their data (for instance the ones which were * allocated through abd_get_offset()). */ { "scatter_cnt", KSTAT_DATA_UINT64 }, /* Amount of data stored in all scatter ABDs tracked by scatter_cnt */ { "scatter_data_size", KSTAT_DATA_UINT64 }, /* * The amount of space wasted at the end of the last chunk across all * scatter ABDs tracked by scatter_cnt. */ { "scatter_chunk_waste", KSTAT_DATA_UINT64 }, /* * The number of compound allocations of a given order. These * allocations are spread over all currently allocated ABDs, and * act as a measure of memory fragmentation. */ { { "scatter_order_N", KSTAT_DATA_UINT64 } }, /* * The number of scatter ABDs which contain multiple chunks. * ABDs are preferentially allocated from the minimum number of * contiguous multi-page chunks, a single chunk is optimal. */ { "scatter_page_multi_chunk", KSTAT_DATA_UINT64 }, /* * The number of scatter ABDs which are split across memory zones. * ABDs are preferentially allocated using pages from a single zone. */ { "scatter_page_multi_zone", KSTAT_DATA_UINT64 }, /* * The total number of retries encountered when attempting to * allocate the pages to populate the scatter ABD. */ { "scatter_page_alloc_retry", KSTAT_DATA_UINT64 }, /* * The total number of retries encountered when attempting to * allocate the sg table for an ABD. */ { "scatter_sg_table_retry", KSTAT_DATA_UINT64 }, }; #define abd_for_each_sg(abd, sg, n, i) \ for_each_sg(ABD_SCATTER(abd).abd_sgl, sg, n, i) unsigned zfs_abd_scatter_max_order = MAX_ORDER - 1; /* * zfs_abd_scatter_min_size is the minimum allocation size to use scatter * ABD's. Smaller allocations will use linear ABD's which uses * zio_[data_]buf_alloc(). * * Scatter ABD's use at least one page each, so sub-page allocations waste * some space when allocated as scatter (e.g. 2KB scatter allocation wastes * half of each page). Using linear ABD's for small allocations means that * they will be put on slabs which contain many allocations. This can * improve memory efficiency, but it also makes it much harder for ARC * evictions to actually free pages, because all the buffers on one slab need * to be freed in order for the slab (and underlying pages) to be freed. * Typically, 512B and 1KB kmem caches have 16 buffers per slab, so it's * possible for them to actually waste more memory than scatter (one page per * buf = wasting 3/4 or 7/8th; one buf per slab = wasting 15/16th). * * Spill blocks are typically 512B and are heavily used on systems running * selinux with the default dnode size and the `xattr=sa` property set. * * By default we use linear allocations for 512B and 1KB, and scatter * allocations for larger (1.5KB and up). */ int zfs_abd_scatter_min_size = 512 * 3; /* * We use a scattered SPA_MAXBLOCKSIZE sized ABD whose pages are * just a single zero'd page. This allows us to conserve memory by * only using a single zero page for the scatterlist. */ abd_t *abd_zero_scatter = NULL; struct page; /* * abd_zero_page we will be an allocated zero'd PAGESIZE buffer, which is * assigned to set each of the pages of abd_zero_scatter. */ static struct page *abd_zero_page = NULL; static kmem_cache_t *abd_cache = NULL; static kstat_t *abd_ksp; static uint_t abd_chunkcnt_for_bytes(size_t size) { return (P2ROUNDUP(size, PAGESIZE) / PAGESIZE); } abd_t * -abd_alloc_struct(size_t size) +abd_alloc_struct_impl(size_t size) { /* * In Linux we do not use the size passed in during ABD * allocation, so we just ignore it. */ abd_t *abd = kmem_cache_alloc(abd_cache, KM_PUSHPAGE); ASSERT3P(abd, !=, NULL); - list_link_init(&abd->abd_gang_link); - mutex_init(&abd->abd_mtx, NULL, MUTEX_DEFAULT, NULL); ABDSTAT_INCR(abdstat_struct_size, sizeof (abd_t)); return (abd); } void -abd_free_struct(abd_t *abd) +abd_free_struct_impl(abd_t *abd) { - mutex_destroy(&abd->abd_mtx); - ASSERT(!list_link_active(&abd->abd_gang_link)); kmem_cache_free(abd_cache, abd); ABDSTAT_INCR(abdstat_struct_size, -(int)sizeof (abd_t)); } #ifdef _KERNEL /* * Mark zfs data pages so they can be excluded from kernel crash dumps */ #ifdef _LP64 #define ABD_FILE_CACHE_PAGE 0x2F5ABDF11ECAC4E static inline void abd_mark_zfs_page(struct page *page) { get_page(page); SetPagePrivate(page); set_page_private(page, ABD_FILE_CACHE_PAGE); } static inline void abd_unmark_zfs_page(struct page *page) { set_page_private(page, 0UL); ClearPagePrivate(page); put_page(page); } #else #define abd_mark_zfs_page(page) #define abd_unmark_zfs_page(page) #endif /* _LP64 */ #ifndef CONFIG_HIGHMEM #ifndef __GFP_RECLAIM #define __GFP_RECLAIM __GFP_WAIT #endif /* * The goal is to minimize fragmentation by preferentially populating ABDs * with higher order compound pages from a single zone. Allocation size is * progressively decreased until it can be satisfied without performing * reclaim or compaction. When necessary this function will degenerate to * allocating individual pages and allowing reclaim to satisfy allocations. */ void abd_alloc_chunks(abd_t *abd, size_t size) { struct list_head pages; struct sg_table table; struct scatterlist *sg; struct page *page, *tmp_page = NULL; gfp_t gfp = __GFP_NOWARN | GFP_NOIO; gfp_t gfp_comp = (gfp | __GFP_NORETRY | __GFP_COMP) & ~__GFP_RECLAIM; int max_order = MIN(zfs_abd_scatter_max_order, MAX_ORDER - 1); int nr_pages = abd_chunkcnt_for_bytes(size); int chunks = 0, zones = 0; size_t remaining_size; int nid = NUMA_NO_NODE; int alloc_pages = 0; INIT_LIST_HEAD(&pages); while (alloc_pages < nr_pages) { unsigned chunk_pages; int order; order = MIN(highbit64(nr_pages - alloc_pages) - 1, max_order); chunk_pages = (1U << order); page = alloc_pages_node(nid, order ? gfp_comp : gfp, order); if (page == NULL) { if (order == 0) { ABDSTAT_BUMP(abdstat_scatter_page_alloc_retry); schedule_timeout_interruptible(1); } else { max_order = MAX(0, order - 1); } continue; } list_add_tail(&page->lru, &pages); if ((nid != NUMA_NO_NODE) && (page_to_nid(page) != nid)) zones++; nid = page_to_nid(page); ABDSTAT_BUMP(abdstat_scatter_orders[order]); chunks++; alloc_pages += chunk_pages; } ASSERT3S(alloc_pages, ==, nr_pages); while (sg_alloc_table(&table, chunks, gfp)) { ABDSTAT_BUMP(abdstat_scatter_sg_table_retry); schedule_timeout_interruptible(1); } sg = table.sgl; remaining_size = size; list_for_each_entry_safe(page, tmp_page, &pages, lru) { size_t sg_size = MIN(PAGESIZE << compound_order(page), remaining_size); sg_set_page(sg, page, sg_size, 0); abd_mark_zfs_page(page); remaining_size -= sg_size; sg = sg_next(sg); list_del(&page->lru); } /* * These conditions ensure that a possible transformation to a linear * ABD would be valid. */ ASSERT(!PageHighMem(sg_page(table.sgl))); ASSERT0(ABD_SCATTER(abd).abd_offset); if (table.nents == 1) { /* * Since there is only one entry, this ABD can be represented * as a linear buffer. All single-page (4K) ABD's can be * represented this way. Some multi-page ABD's can also be * represented this way, if we were able to allocate a single * "chunk" (higher-order "page" which represents a power-of-2 * series of physically-contiguous pages). This is often the * case for 2-page (8K) ABD's. * * Representing a single-entry scatter ABD as a linear ABD * has the performance advantage of avoiding the copy (and * allocation) in abd_borrow_buf_copy / abd_return_buf_copy. * A performance increase of around 5% has been observed for * ARC-cached reads (of small blocks which can take advantage * of this). * * Note that this optimization is only possible because the * pages are always mapped into the kernel's address space. * This is not the case for highmem pages, so the * optimization can not be made there. */ abd->abd_flags |= ABD_FLAG_LINEAR; abd->abd_flags |= ABD_FLAG_LINEAR_PAGE; abd->abd_u.abd_linear.abd_sgl = table.sgl; ABD_LINEAR_BUF(abd) = page_address(sg_page(table.sgl)); } else if (table.nents > 1) { ABDSTAT_BUMP(abdstat_scatter_page_multi_chunk); abd->abd_flags |= ABD_FLAG_MULTI_CHUNK; if (zones) { ABDSTAT_BUMP(abdstat_scatter_page_multi_zone); abd->abd_flags |= ABD_FLAG_MULTI_ZONE; } ABD_SCATTER(abd).abd_sgl = table.sgl; ABD_SCATTER(abd).abd_nents = table.nents; } } #else /* * Allocate N individual pages to construct a scatter ABD. This function * makes no attempt to request contiguous pages and requires the minimal * number of kernel interfaces. It's designed for maximum compatibility. */ void abd_alloc_chunks(abd_t *abd, size_t size) { struct scatterlist *sg = NULL; struct sg_table table; struct page *page; gfp_t gfp = __GFP_NOWARN | GFP_NOIO; int nr_pages = abd_chunkcnt_for_bytes(size); int i = 0; while (sg_alloc_table(&table, nr_pages, gfp)) { ABDSTAT_BUMP(abdstat_scatter_sg_table_retry); schedule_timeout_interruptible(1); } ASSERT3U(table.nents, ==, nr_pages); ABD_SCATTER(abd).abd_sgl = table.sgl; ABD_SCATTER(abd).abd_nents = nr_pages; abd_for_each_sg(abd, sg, nr_pages, i) { while ((page = __page_cache_alloc(gfp)) == NULL) { ABDSTAT_BUMP(abdstat_scatter_page_alloc_retry); schedule_timeout_interruptible(1); } ABDSTAT_BUMP(abdstat_scatter_orders[0]); sg_set_page(sg, page, PAGESIZE, 0); abd_mark_zfs_page(page); } if (nr_pages > 1) { ABDSTAT_BUMP(abdstat_scatter_page_multi_chunk); abd->abd_flags |= ABD_FLAG_MULTI_CHUNK; } } #endif /* !CONFIG_HIGHMEM */ /* * This must be called if any of the sg_table allocation functions * are called. */ static void abd_free_sg_table(abd_t *abd) { struct sg_table table; table.sgl = ABD_SCATTER(abd).abd_sgl; table.nents = table.orig_nents = ABD_SCATTER(abd).abd_nents; sg_free_table(&table); } void abd_free_chunks(abd_t *abd) { struct scatterlist *sg = NULL; struct page *page; int nr_pages = ABD_SCATTER(abd).abd_nents; int order, i = 0; if (abd->abd_flags & ABD_FLAG_MULTI_ZONE) ABDSTAT_BUMPDOWN(abdstat_scatter_page_multi_zone); if (abd->abd_flags & ABD_FLAG_MULTI_CHUNK) ABDSTAT_BUMPDOWN(abdstat_scatter_page_multi_chunk); abd_for_each_sg(abd, sg, nr_pages, i) { page = sg_page(sg); abd_unmark_zfs_page(page); order = compound_order(page); __free_pages(page, order); ASSERT3U(sg->length, <=, PAGE_SIZE << order); ABDSTAT_BUMPDOWN(abdstat_scatter_orders[order]); } abd_free_sg_table(abd); } /* * Allocate scatter ABD of size SPA_MAXBLOCKSIZE, where each page in * the scatterlist will be set to the zero'd out buffer abd_zero_page. */ static void abd_alloc_zero_scatter(void) { struct scatterlist *sg = NULL; struct sg_table table; gfp_t gfp = __GFP_NOWARN | GFP_NOIO; gfp_t gfp_zero_page = gfp | __GFP_ZERO; int nr_pages = abd_chunkcnt_for_bytes(SPA_MAXBLOCKSIZE); int i = 0; while ((abd_zero_page = __page_cache_alloc(gfp_zero_page)) == NULL) { ABDSTAT_BUMP(abdstat_scatter_page_alloc_retry); schedule_timeout_interruptible(1); } abd_mark_zfs_page(abd_zero_page); while (sg_alloc_table(&table, nr_pages, gfp)) { ABDSTAT_BUMP(abdstat_scatter_sg_table_retry); schedule_timeout_interruptible(1); } ASSERT3U(table.nents, ==, nr_pages); abd_zero_scatter = abd_alloc_struct(SPA_MAXBLOCKSIZE); - abd_zero_scatter->abd_flags = ABD_FLAG_OWNER; + abd_zero_scatter->abd_flags |= ABD_FLAG_OWNER; ABD_SCATTER(abd_zero_scatter).abd_offset = 0; ABD_SCATTER(abd_zero_scatter).abd_sgl = table.sgl; ABD_SCATTER(abd_zero_scatter).abd_nents = nr_pages; abd_zero_scatter->abd_size = SPA_MAXBLOCKSIZE; - abd_zero_scatter->abd_parent = NULL; abd_zero_scatter->abd_flags |= ABD_FLAG_MULTI_CHUNK | ABD_FLAG_ZEROS; - zfs_refcount_create(&abd_zero_scatter->abd_children); abd_for_each_sg(abd_zero_scatter, sg, nr_pages, i) { sg_set_page(sg, abd_zero_page, PAGESIZE, 0); } ABDSTAT_BUMP(abdstat_scatter_cnt); ABDSTAT_INCR(abdstat_scatter_data_size, PAGESIZE); ABDSTAT_BUMP(abdstat_scatter_page_multi_chunk); } #else /* _KERNEL */ #ifndef PAGE_SHIFT #define PAGE_SHIFT (highbit64(PAGESIZE)-1) #endif #define zfs_kmap_atomic(chunk, km) ((void *)chunk) #define zfs_kunmap_atomic(addr, km) do { (void)(addr); } while (0) #define local_irq_save(flags) do { (void)(flags); } while (0) #define local_irq_restore(flags) do { (void)(flags); } while (0) #define nth_page(pg, i) \ ((struct page *)((void *)(pg) + (i) * PAGESIZE)) struct scatterlist { struct page *page; int length; int end; }; static void sg_init_table(struct scatterlist *sg, int nr) { memset(sg, 0, nr * sizeof (struct scatterlist)); sg[nr - 1].end = 1; } /* * This must be called if any of the sg_table allocation functions * are called. */ static void abd_free_sg_table(abd_t *abd) { int nents = ABD_SCATTER(abd).abd_nents; vmem_free(ABD_SCATTER(abd).abd_sgl, nents * sizeof (struct scatterlist)); } #define for_each_sg(sgl, sg, nr, i) \ for ((i) = 0, (sg) = (sgl); (i) < (nr); (i)++, (sg) = sg_next(sg)) static inline void sg_set_page(struct scatterlist *sg, struct page *page, unsigned int len, unsigned int offset) { /* currently we don't use offset */ ASSERT(offset == 0); sg->page = page; sg->length = len; } static inline struct page * sg_page(struct scatterlist *sg) { return (sg->page); } static inline struct scatterlist * sg_next(struct scatterlist *sg) { if (sg->end) return (NULL); return (sg + 1); } void abd_alloc_chunks(abd_t *abd, size_t size) { unsigned nr_pages = abd_chunkcnt_for_bytes(size); struct scatterlist *sg; int i; ABD_SCATTER(abd).abd_sgl = vmem_alloc(nr_pages * sizeof (struct scatterlist), KM_SLEEP); sg_init_table(ABD_SCATTER(abd).abd_sgl, nr_pages); abd_for_each_sg(abd, sg, nr_pages, i) { struct page *p = umem_alloc_aligned(PAGESIZE, 64, KM_SLEEP); sg_set_page(sg, p, PAGESIZE, 0); } ABD_SCATTER(abd).abd_nents = nr_pages; } void abd_free_chunks(abd_t *abd) { int i, n = ABD_SCATTER(abd).abd_nents; struct scatterlist *sg; abd_for_each_sg(abd, sg, n, i) { for (int j = 0; j < sg->length; j += PAGESIZE) { struct page *p = nth_page(sg_page(sg), j >> PAGE_SHIFT); umem_free(p, PAGESIZE); } } abd_free_sg_table(abd); } static void abd_alloc_zero_scatter(void) { unsigned nr_pages = abd_chunkcnt_for_bytes(SPA_MAXBLOCKSIZE); struct scatterlist *sg; int i; abd_zero_page = umem_alloc_aligned(PAGESIZE, 64, KM_SLEEP); memset(abd_zero_page, 0, PAGESIZE); abd_zero_scatter = abd_alloc_struct(SPA_MAXBLOCKSIZE); - abd_zero_scatter->abd_flags = ABD_FLAG_OWNER; + abd_zero_scatter->abd_flags |= ABD_FLAG_OWNER; abd_zero_scatter->abd_flags |= ABD_FLAG_MULTI_CHUNK | ABD_FLAG_ZEROS; ABD_SCATTER(abd_zero_scatter).abd_offset = 0; ABD_SCATTER(abd_zero_scatter).abd_nents = nr_pages; abd_zero_scatter->abd_size = SPA_MAXBLOCKSIZE; - abd_zero_scatter->abd_parent = NULL; zfs_refcount_create(&abd_zero_scatter->abd_children); ABD_SCATTER(abd_zero_scatter).abd_sgl = vmem_alloc(nr_pages * sizeof (struct scatterlist), KM_SLEEP); sg_init_table(ABD_SCATTER(abd_zero_scatter).abd_sgl, nr_pages); abd_for_each_sg(abd_zero_scatter, sg, nr_pages, i) { sg_set_page(sg, abd_zero_page, PAGESIZE, 0); } ABDSTAT_BUMP(abdstat_scatter_cnt); ABDSTAT_INCR(abdstat_scatter_data_size, PAGESIZE); ABDSTAT_BUMP(abdstat_scatter_page_multi_chunk); } #endif /* _KERNEL */ boolean_t abd_size_alloc_linear(size_t size) { return (size < zfs_abd_scatter_min_size ? B_TRUE : B_FALSE); } void abd_update_scatter_stats(abd_t *abd, abd_stats_op_t op) { ASSERT(op == ABDSTAT_INCR || op == ABDSTAT_DECR); int waste = P2ROUNDUP(abd->abd_size, PAGESIZE) - abd->abd_size; if (op == ABDSTAT_INCR) { ABDSTAT_BUMP(abdstat_scatter_cnt); ABDSTAT_INCR(abdstat_scatter_data_size, abd->abd_size); ABDSTAT_INCR(abdstat_scatter_chunk_waste, waste); arc_space_consume(waste, ARC_SPACE_ABD_CHUNK_WASTE); } else { ABDSTAT_BUMPDOWN(abdstat_scatter_cnt); ABDSTAT_INCR(abdstat_scatter_data_size, -(int)abd->abd_size); ABDSTAT_INCR(abdstat_scatter_chunk_waste, -waste); arc_space_return(waste, ARC_SPACE_ABD_CHUNK_WASTE); } } void abd_update_linear_stats(abd_t *abd, abd_stats_op_t op) { ASSERT(op == ABDSTAT_INCR || op == ABDSTAT_DECR); if (op == ABDSTAT_INCR) { ABDSTAT_BUMP(abdstat_linear_cnt); ABDSTAT_INCR(abdstat_linear_data_size, abd->abd_size); } else { ABDSTAT_BUMPDOWN(abdstat_linear_cnt); ABDSTAT_INCR(abdstat_linear_data_size, -(int)abd->abd_size); } } void abd_verify_scatter(abd_t *abd) { size_t n; int i = 0; struct scatterlist *sg = NULL; ASSERT3U(ABD_SCATTER(abd).abd_nents, >, 0); ASSERT3U(ABD_SCATTER(abd).abd_offset, <, ABD_SCATTER(abd).abd_sgl->length); n = ABD_SCATTER(abd).abd_nents; abd_for_each_sg(abd, sg, n, i) { ASSERT3P(sg_page(sg), !=, NULL); } } static void abd_free_zero_scatter(void) { - zfs_refcount_destroy(&abd_zero_scatter->abd_children); ABDSTAT_BUMPDOWN(abdstat_scatter_cnt); ABDSTAT_INCR(abdstat_scatter_data_size, -(int)PAGESIZE); ABDSTAT_BUMPDOWN(abdstat_scatter_page_multi_chunk); abd_free_sg_table(abd_zero_scatter); abd_free_struct(abd_zero_scatter); abd_zero_scatter = NULL; ASSERT3P(abd_zero_page, !=, NULL); #if defined(_KERNEL) abd_unmark_zfs_page(abd_zero_page); __free_page(abd_zero_page); #else umem_free(abd_zero_page, PAGESIZE); #endif /* _KERNEL */ } void abd_init(void) { int i; abd_cache = kmem_cache_create("abd_t", sizeof (abd_t), 0, NULL, NULL, NULL, NULL, NULL, 0); abd_ksp = kstat_create("zfs", 0, "abdstats", "misc", KSTAT_TYPE_NAMED, sizeof (abd_stats) / sizeof (kstat_named_t), KSTAT_FLAG_VIRTUAL); if (abd_ksp != NULL) { for (i = 0; i < MAX_ORDER; i++) { snprintf(abd_stats.abdstat_scatter_orders[i].name, KSTAT_STRLEN, "scatter_order_%d", i); abd_stats.abdstat_scatter_orders[i].data_type = KSTAT_DATA_UINT64; } abd_ksp->ks_data = &abd_stats; kstat_install(abd_ksp); } abd_alloc_zero_scatter(); } void abd_fini(void) { abd_free_zero_scatter(); if (abd_ksp != NULL) { kstat_delete(abd_ksp); abd_ksp = NULL; } if (abd_cache) { kmem_cache_destroy(abd_cache); abd_cache = NULL; } } void abd_free_linear_page(abd_t *abd) { /* Transform it back into a scatter ABD for freeing */ struct scatterlist *sg = abd->abd_u.abd_linear.abd_sgl; abd->abd_flags &= ~ABD_FLAG_LINEAR; abd->abd_flags &= ~ABD_FLAG_LINEAR_PAGE; ABD_SCATTER(abd).abd_nents = 1; ABD_SCATTER(abd).abd_offset = 0; ABD_SCATTER(abd).abd_sgl = sg; abd_free_chunks(abd); - zfs_refcount_destroy(&abd->abd_children); abd_update_scatter_stats(abd, ABDSTAT_DECR); - abd_free_struct(abd); } /* * If we're going to use this ABD for doing I/O using the block layer, the * consumer of the ABD data doesn't care if it's scattered or not, and we don't * plan to store this ABD in memory for a long period of time, we should * allocate the ABD type that requires the least data copying to do the I/O. * * On Linux the optimal thing to do would be to use abd_get_offset() and * construct a new ABD which shares the original pages thereby eliminating * the copy. But for the moment a new linear ABD is allocated until this * performance optimization can be implemented. */ abd_t * abd_alloc_for_io(size_t size, boolean_t is_metadata) { return (abd_alloc(size, is_metadata)); } abd_t * -abd_get_offset_scatter(abd_t *sabd, size_t off) +abd_get_offset_scatter(abd_t *abd, abd_t *sabd, size_t off) { - abd_t *abd = NULL; int i = 0; struct scatterlist *sg = NULL; abd_verify(sabd); ASSERT3U(off, <=, sabd->abd_size); size_t new_offset = ABD_SCATTER(sabd).abd_offset + off; - abd = abd_alloc_struct(0); + if (abd == NULL) + abd = abd_alloc_struct(0); /* * Even if this buf is filesystem metadata, we only track that * if we own the underlying data buffer, which is not true in * this case. Therefore, we don't ever use ABD_FLAG_META here. */ - abd->abd_flags = 0; abd_for_each_sg(sabd, sg, ABD_SCATTER(sabd).abd_nents, i) { if (new_offset < sg->length) break; new_offset -= sg->length; } ABD_SCATTER(abd).abd_sgl = sg; ABD_SCATTER(abd).abd_offset = new_offset; ABD_SCATTER(abd).abd_nents = ABD_SCATTER(sabd).abd_nents - i; return (abd); } /* * Initialize the abd_iter. */ void abd_iter_init(struct abd_iter *aiter, abd_t *abd) { ASSERT(!abd_is_gang(abd)); abd_verify(abd); aiter->iter_abd = abd; aiter->iter_mapaddr = NULL; aiter->iter_mapsize = 0; aiter->iter_pos = 0; if (abd_is_linear(abd)) { aiter->iter_offset = 0; aiter->iter_sg = NULL; } else { aiter->iter_offset = ABD_SCATTER(abd).abd_offset; aiter->iter_sg = ABD_SCATTER(abd).abd_sgl; } } /* * This is just a helper function to see if we have exhausted the * abd_iter and reached the end. */ boolean_t abd_iter_at_end(struct abd_iter *aiter) { return (aiter->iter_pos == aiter->iter_abd->abd_size); } /* * Advance the iterator by a certain amount. Cannot be called when a chunk is * in use. This can be safely called when the aiter has already exhausted, in * which case this does nothing. */ void abd_iter_advance(struct abd_iter *aiter, size_t amount) { ASSERT3P(aiter->iter_mapaddr, ==, NULL); ASSERT0(aiter->iter_mapsize); /* There's nothing left to advance to, so do nothing */ if (abd_iter_at_end(aiter)) return; aiter->iter_pos += amount; aiter->iter_offset += amount; if (!abd_is_linear(aiter->iter_abd)) { while (aiter->iter_offset >= aiter->iter_sg->length) { aiter->iter_offset -= aiter->iter_sg->length; aiter->iter_sg = sg_next(aiter->iter_sg); if (aiter->iter_sg == NULL) { ASSERT0(aiter->iter_offset); break; } } } } /* * Map the current chunk into aiter. This can be safely called when the aiter * has already exhausted, in which case this does nothing. */ void abd_iter_map(struct abd_iter *aiter) { void *paddr; size_t offset = 0; ASSERT3P(aiter->iter_mapaddr, ==, NULL); ASSERT0(aiter->iter_mapsize); /* There's nothing left to iterate over, so do nothing */ if (abd_iter_at_end(aiter)) return; if (abd_is_linear(aiter->iter_abd)) { ASSERT3U(aiter->iter_pos, ==, aiter->iter_offset); offset = aiter->iter_offset; aiter->iter_mapsize = aiter->iter_abd->abd_size - offset; paddr = ABD_LINEAR_BUF(aiter->iter_abd); } else { offset = aiter->iter_offset; aiter->iter_mapsize = MIN(aiter->iter_sg->length - offset, aiter->iter_abd->abd_size - aiter->iter_pos); paddr = zfs_kmap_atomic(sg_page(aiter->iter_sg), km_table[aiter->iter_km]); } aiter->iter_mapaddr = (char *)paddr + offset; } /* * Unmap the current chunk from aiter. This can be safely called when the aiter * has already exhausted, in which case this does nothing. */ void abd_iter_unmap(struct abd_iter *aiter) { /* There's nothing left to unmap, so do nothing */ if (abd_iter_at_end(aiter)) return; if (!abd_is_linear(aiter->iter_abd)) { /* LINTED E_FUNC_SET_NOT_USED */ zfs_kunmap_atomic(aiter->iter_mapaddr - aiter->iter_offset, km_table[aiter->iter_km]); } ASSERT3P(aiter->iter_mapaddr, !=, NULL); ASSERT3U(aiter->iter_mapsize, >, 0); aiter->iter_mapaddr = NULL; aiter->iter_mapsize = 0; } void abd_cache_reap_now(void) { } #if defined(_KERNEL) /* * bio_nr_pages for ABD. * @off is the offset in @abd */ unsigned long abd_nr_pages_off(abd_t *abd, unsigned int size, size_t off) { unsigned long pos; while (abd_is_gang(abd)) abd = abd_gang_get_offset(abd, &off); ASSERT(!abd_is_gang(abd)); if (abd_is_linear(abd)) pos = (unsigned long)abd_to_buf(abd) + off; else pos = ABD_SCATTER(abd).abd_offset + off; return ((pos + size + PAGESIZE - 1) >> PAGE_SHIFT) - (pos >> PAGE_SHIFT); } static unsigned int bio_map(struct bio *bio, void *buf_ptr, unsigned int bio_size) { unsigned int offset, size, i; struct page *page; offset = offset_in_page(buf_ptr); for (i = 0; i < bio->bi_max_vecs; i++) { size = PAGE_SIZE - offset; if (bio_size <= 0) break; if (size > bio_size) size = bio_size; if (is_vmalloc_addr(buf_ptr)) page = vmalloc_to_page(buf_ptr); else page = virt_to_page(buf_ptr); /* * Some network related block device uses tcp_sendpage, which * doesn't behave well when using 0-count page, this is a * safety net to catch them. */ ASSERT3S(page_count(page), >, 0); if (bio_add_page(bio, page, size, offset) != size) break; buf_ptr += size; bio_size -= size; offset = 0; } return (bio_size); } /* * bio_map for gang ABD. */ static unsigned int abd_gang_bio_map_off(struct bio *bio, abd_t *abd, unsigned int io_size, size_t off) { ASSERT(abd_is_gang(abd)); for (abd_t *cabd = abd_gang_get_offset(abd, &off); cabd != NULL; cabd = list_next(&ABD_GANG(abd).abd_gang_chain, cabd)) { ASSERT3U(off, <, cabd->abd_size); int size = MIN(io_size, cabd->abd_size - off); int remainder = abd_bio_map_off(bio, cabd, size, off); io_size -= (size - remainder); if (io_size == 0 || remainder > 0) return (io_size); off = 0; } ASSERT0(io_size); return (io_size); } /* * bio_map for ABD. * @off is the offset in @abd * Remaining IO size is returned */ unsigned int abd_bio_map_off(struct bio *bio, abd_t *abd, unsigned int io_size, size_t off) { int i; struct abd_iter aiter; ASSERT3U(io_size, <=, abd->abd_size - off); if (abd_is_linear(abd)) return (bio_map(bio, ((char *)abd_to_buf(abd)) + off, io_size)); ASSERT(!abd_is_linear(abd)); if (abd_is_gang(abd)) return (abd_gang_bio_map_off(bio, abd, io_size, off)); abd_iter_init(&aiter, abd); abd_iter_advance(&aiter, off); for (i = 0; i < bio->bi_max_vecs; i++) { struct page *pg; size_t len, sgoff, pgoff; struct scatterlist *sg; if (io_size <= 0) break; sg = aiter.iter_sg; sgoff = aiter.iter_offset; pgoff = sgoff & (PAGESIZE - 1); len = MIN(io_size, PAGESIZE - pgoff); ASSERT(len > 0); pg = nth_page(sg_page(sg), sgoff >> PAGE_SHIFT); if (bio_add_page(bio, pg, len, pgoff) != len) break; io_size -= len; abd_iter_advance(&aiter, len); } return (io_size); } /* Tunable Parameters */ module_param(zfs_abd_scatter_enabled, int, 0644); MODULE_PARM_DESC(zfs_abd_scatter_enabled, "Toggle whether ABD allocations must be linear."); module_param(zfs_abd_scatter_min_size, int, 0644); MODULE_PARM_DESC(zfs_abd_scatter_min_size, "Minimum size of scatter allocations."); /* CSTYLED */ module_param(zfs_abd_scatter_max_order, uint, 0644); MODULE_PARM_DESC(zfs_abd_scatter_max_order, "Maximum order allocation used for a scatter ABD."); #endif diff --git a/module/zfs/abd.c b/module/zfs/abd.c index 68d4aa5f5cb4..d42b9992beea 100644 --- a/module/zfs/abd.c +++ b/module/zfs/abd.c @@ -1,1217 +1,1199 @@ /* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (c) 2014 by Chunwei Chen. All rights reserved. * Copyright (c) 2019 by Delphix. All rights reserved. */ /* * ARC buffer data (ABD). * * ABDs are an abstract data structure for the ARC which can use two * different ways of storing the underlying data: * * (a) Linear buffer. In this case, all the data in the ABD is stored in one * contiguous buffer in memory (from a zio_[data_]buf_* kmem cache). * * +-------------------+ * | ABD (linear) | * | abd_flags = ... | * | abd_size = ... | +--------------------------------+ * | abd_buf ------------->| raw buffer of size abd_size | * +-------------------+ +--------------------------------+ * no abd_chunks * * (b) Scattered buffer. In this case, the data in the ABD is split into * equal-sized chunks (from the abd_chunk_cache kmem_cache), with pointers * to the chunks recorded in an array at the end of the ABD structure. * * +-------------------+ * | ABD (scattered) | * | abd_flags = ... | * | abd_size = ... | * | abd_offset = 0 | +-----------+ * | abd_chunks[0] ----------------------------->| chunk 0 | * | abd_chunks[1] ---------------------+ +-----------+ * | ... | | +-----------+ * | abd_chunks[N-1] ---------+ +------->| chunk 1 | * +-------------------+ | +-----------+ * | ... * | +-----------+ * +----------------->| chunk N-1 | * +-----------+ * * In addition to directly allocating a linear or scattered ABD, it is also * possible to create an ABD by requesting the "sub-ABD" starting at an offset * within an existing ABD. In linear buffers this is simple (set abd_buf of * the new ABD to the starting point within the original raw buffer), but * scattered ABDs are a little more complex. The new ABD makes a copy of the * relevant abd_chunks pointers (but not the underlying data). However, to * provide arbitrary rather than only chunk-aligned starting offsets, it also * tracks an abd_offset field which represents the starting point of the data * within the first chunk in abd_chunks. For both linear and scattered ABDs, * creating an offset ABD marks the original ABD as the offset's parent, and the * original ABD's abd_children refcount is incremented. This data allows us to * ensure the root ABD isn't deleted before its children. * * Most consumers should never need to know what type of ABD they're using -- * the ABD public API ensures that it's possible to transparently switch from * using a linear ABD to a scattered one when doing so would be beneficial. * * If you need to use the data within an ABD directly, if you know it's linear * (because you allocated it) you can use abd_to_buf() to access the underlying * raw buffer. Otherwise, you should use one of the abd_borrow_buf* functions * which will allocate a raw buffer if necessary. Use the abd_return_buf* * functions to return any raw buffers that are no longer necessary when you're * done using them. * * There are a variety of ABD APIs that implement basic buffer operations: * compare, copy, read, write, and fill with zeroes. If you need a custom * function which progressively accesses the whole ABD, use the abd_iterate_* * functions. * * As an additional feature, linear and scatter ABD's can be stitched together * by using the gang ABD type (abd_alloc_gang_abd()). This allows for * multiple ABDs to be viewed as a singular ABD. * * It is possible to make all ABDs linear by setting zfs_abd_scatter_enabled to * B_FALSE. */ #include #include #include #include #include /* see block comment above for description */ int zfs_abd_scatter_enabled = B_TRUE; -boolean_t -abd_is_linear(abd_t *abd) -{ - return ((abd->abd_flags & ABD_FLAG_LINEAR) != 0 ? B_TRUE : B_FALSE); -} - -boolean_t -abd_is_linear_page(abd_t *abd) -{ - return ((abd->abd_flags & ABD_FLAG_LINEAR_PAGE) != 0 ? - B_TRUE : B_FALSE); -} - -boolean_t -abd_is_gang(abd_t *abd) -{ - return ((abd->abd_flags & ABD_FLAG_GANG) != 0 ? B_TRUE : - B_FALSE); -} - void abd_verify(abd_t *abd) { ASSERT3U(abd->abd_size, >, 0); ASSERT3U(abd->abd_size, <=, SPA_MAXBLOCKSIZE); ASSERT3U(abd->abd_flags, ==, abd->abd_flags & (ABD_FLAG_LINEAR | ABD_FLAG_OWNER | ABD_FLAG_META | ABD_FLAG_MULTI_ZONE | ABD_FLAG_MULTI_CHUNK | ABD_FLAG_LINEAR_PAGE | ABD_FLAG_GANG | - ABD_FLAG_GANG_FREE | ABD_FLAG_ZEROS)); + ABD_FLAG_GANG_FREE | ABD_FLAG_ZEROS | ABD_FLAG_ALLOCD)); IMPLY(abd->abd_parent != NULL, !(abd->abd_flags & ABD_FLAG_OWNER)); IMPLY(abd->abd_flags & ABD_FLAG_META, abd->abd_flags & ABD_FLAG_OWNER); if (abd_is_linear(abd)) { ASSERT3P(ABD_LINEAR_BUF(abd), !=, NULL); } else if (abd_is_gang(abd)) { uint_t child_sizes = 0; for (abd_t *cabd = list_head(&ABD_GANG(abd).abd_gang_chain); cabd != NULL; cabd = list_next(&ABD_GANG(abd).abd_gang_chain, cabd)) { ASSERT(list_link_active(&cabd->abd_gang_link)); child_sizes += cabd->abd_size; abd_verify(cabd); } ASSERT3U(abd->abd_size, ==, child_sizes); } else { abd_verify_scatter(abd); } } -uint_t -abd_get_size(abd_t *abd) +static void +abd_init_struct(abd_t *abd) { - abd_verify(abd); - return (abd->abd_size); + list_link_init(&abd->abd_gang_link); + mutex_init(&abd->abd_mtx, NULL, MUTEX_DEFAULT, NULL); + zfs_refcount_create(&abd->abd_children); + abd->abd_flags = 0; + abd->abd_parent = NULL; + abd->abd_size = 0; +} + +static void +abd_fini_struct(abd_t *abd) +{ + mutex_destroy(&abd->abd_mtx); + ASSERT(!list_link_active(&abd->abd_gang_link)); + zfs_refcount_destroy(&abd->abd_children); +} + +abd_t * +abd_alloc_struct(size_t size) +{ + abd_t *abd = abd_alloc_struct_impl(size); + abd_init_struct(abd); + abd->abd_flags |= ABD_FLAG_ALLOCD; + return (abd); +} + +void +abd_free_struct(abd_t *abd) +{ + abd_fini_struct(abd); + abd_free_struct_impl(abd); } /* * Allocate an ABD, along with its own underlying data buffers. Use this if you * don't care whether the ABD is linear or not. */ abd_t * abd_alloc(size_t size, boolean_t is_metadata) { if (!zfs_abd_scatter_enabled || abd_size_alloc_linear(size)) return (abd_alloc_linear(size, is_metadata)); VERIFY3U(size, <=, SPA_MAXBLOCKSIZE); abd_t *abd = abd_alloc_struct(size); - abd->abd_flags = ABD_FLAG_OWNER; + abd->abd_flags |= ABD_FLAG_OWNER; abd->abd_u.abd_scatter.abd_offset = 0; abd_alloc_chunks(abd, size); if (is_metadata) { abd->abd_flags |= ABD_FLAG_META; } abd->abd_size = size; - abd->abd_parent = NULL; - zfs_refcount_create(&abd->abd_children); abd_update_scatter_stats(abd, ABDSTAT_INCR); return (abd); } -static void -abd_free_scatter(abd_t *abd) -{ - abd_free_chunks(abd); - - zfs_refcount_destroy(&abd->abd_children); - abd_update_scatter_stats(abd, ABDSTAT_DECR); - abd_free_struct(abd); -} - -static void -abd_put_gang_abd(abd_t *abd) -{ - ASSERT(abd_is_gang(abd)); - abd_t *cabd; - - while ((cabd = list_remove_head(&ABD_GANG(abd).abd_gang_chain)) - != NULL) { - ASSERT0(cabd->abd_flags & ABD_FLAG_GANG_FREE); - abd->abd_size -= cabd->abd_size; - abd_put(cabd); - } - ASSERT0(abd->abd_size); - list_destroy(&ABD_GANG(abd).abd_gang_chain); -} - -/* - * Free an ABD allocated from abd_get_offset() or abd_get_from_buf(). Will not - * free the underlying scatterlist or buffer. - */ -void -abd_put(abd_t *abd) -{ - if (abd == NULL) - return; - - abd_verify(abd); - ASSERT(!(abd->abd_flags & ABD_FLAG_OWNER)); - - if (abd->abd_parent != NULL) { - (void) zfs_refcount_remove_many(&abd->abd_parent->abd_children, - abd->abd_size, abd); - } - - if (abd_is_gang(abd)) - abd_put_gang_abd(abd); - - zfs_refcount_destroy(&abd->abd_children); - abd_free_struct(abd); -} - /* * Allocate an ABD that must be linear, along with its own underlying data * buffer. Only use this when it would be very annoying to write your ABD * consumer with a scattered ABD. */ abd_t * abd_alloc_linear(size_t size, boolean_t is_metadata) { abd_t *abd = abd_alloc_struct(0); VERIFY3U(size, <=, SPA_MAXBLOCKSIZE); - abd->abd_flags = ABD_FLAG_LINEAR | ABD_FLAG_OWNER; + abd->abd_flags |= ABD_FLAG_LINEAR | ABD_FLAG_OWNER; if (is_metadata) { abd->abd_flags |= ABD_FLAG_META; } abd->abd_size = size; - abd->abd_parent = NULL; - zfs_refcount_create(&abd->abd_children); if (is_metadata) { ABD_LINEAR_BUF(abd) = zio_buf_alloc(size); } else { ABD_LINEAR_BUF(abd) = zio_data_buf_alloc(size); } abd_update_linear_stats(abd, ABDSTAT_INCR); return (abd); } static void abd_free_linear(abd_t *abd) { if (abd_is_linear_page(abd)) { abd_free_linear_page(abd); return; } if (abd->abd_flags & ABD_FLAG_META) { zio_buf_free(ABD_LINEAR_BUF(abd), abd->abd_size); } else { zio_data_buf_free(ABD_LINEAR_BUF(abd), abd->abd_size); } - zfs_refcount_destroy(&abd->abd_children); abd_update_linear_stats(abd, ABDSTAT_DECR); - - abd_free_struct(abd); } static void abd_free_gang_abd(abd_t *abd) { ASSERT(abd_is_gang(abd)); - abd_t *cabd = list_head(&ABD_GANG(abd).abd_gang_chain); + abd_t *cabd; - while (cabd != NULL) { + while ((cabd = list_head(&ABD_GANG(abd).abd_gang_chain)) != NULL) { /* * We must acquire the child ABDs mutex to ensure that if it * is being added to another gang ABD we will set the link * as inactive when removing it from this gang ABD and before * adding it to the other gang ABD. */ mutex_enter(&cabd->abd_mtx); ASSERT(list_link_active(&cabd->abd_gang_link)); list_remove(&ABD_GANG(abd).abd_gang_chain, cabd); mutex_exit(&cabd->abd_mtx); abd->abd_size -= cabd->abd_size; - if (cabd->abd_flags & ABD_FLAG_GANG_FREE) { - if (cabd->abd_flags & ABD_FLAG_OWNER) - abd_free(cabd); - else - abd_put(cabd); - } - cabd = list_head(&ABD_GANG(abd).abd_gang_chain); + if (cabd->abd_flags & ABD_FLAG_GANG_FREE) + abd_free(cabd); } ASSERT0(abd->abd_size); list_destroy(&ABD_GANG(abd).abd_gang_chain); - zfs_refcount_destroy(&abd->abd_children); - abd_free_struct(abd); +} + +static void +abd_free_scatter(abd_t *abd) +{ + abd_free_chunks(abd); + abd_update_scatter_stats(abd, ABDSTAT_DECR); } /* - * Free an ABD. Only use this on ABDs allocated with abd_alloc(), - * abd_alloc_linear(), or abd_alloc_gang_abd(). + * Free an ABD. Use with any kind of abd: those created with abd_alloc_*() + * and abd_get_*(), including abd_get_offset_struct(). + * + * If the ABD was created with abd_alloc_*(), the underlying data + * (scatterlist or linear buffer) will also be freed. (Subject to ownership + * changes via abd_*_ownership_of_buf().) + * + * Unless the ABD was created with abd_get_offset_struct(), the abd_t will + * also be freed. */ void abd_free(abd_t *abd) { if (abd == NULL) return; abd_verify(abd); - ASSERT3P(abd->abd_parent, ==, NULL); - ASSERT(abd->abd_flags & ABD_FLAG_OWNER); - if (abd_is_linear(abd)) - abd_free_linear(abd); - else if (abd_is_gang(abd)) + IMPLY(abd->abd_flags & ABD_FLAG_OWNER, abd->abd_parent == NULL); + + if (abd_is_gang(abd)) { abd_free_gang_abd(abd); - else - abd_free_scatter(abd); + } else if (abd_is_linear(abd)) { + if (abd->abd_flags & ABD_FLAG_OWNER) + abd_free_linear(abd); + } else { + if (abd->abd_flags & ABD_FLAG_OWNER) + abd_free_scatter(abd); + } + + if (abd->abd_parent != NULL) { + (void) zfs_refcount_remove_many(&abd->abd_parent->abd_children, + abd->abd_size, abd); + } + + abd_fini_struct(abd); + if (abd->abd_flags & ABD_FLAG_ALLOCD) + abd_free_struct_impl(abd); } /* * Allocate an ABD of the same format (same metadata flag, same scatterize * setting) as another ABD. */ abd_t * abd_alloc_sametype(abd_t *sabd, size_t size) { boolean_t is_metadata = (sabd->abd_flags & ABD_FLAG_META) != 0; if (abd_is_linear(sabd) && !abd_is_linear_page(sabd)) { return (abd_alloc_linear(size, is_metadata)); } else { return (abd_alloc(size, is_metadata)); } } - /* * Create gang ABD that will be the head of a list of ABD's. This is used * to "chain" scatter/gather lists together when constructing aggregated * IO's. To free this abd, abd_free() must be called. */ abd_t * -abd_alloc_gang_abd(void) +abd_alloc_gang(void) { - abd_t *abd; - - abd = abd_alloc_struct(0); - abd->abd_flags = ABD_FLAG_GANG | ABD_FLAG_OWNER; - abd->abd_size = 0; - abd->abd_parent = NULL; + abd_t *abd = abd_alloc_struct(0); + abd->abd_flags |= ABD_FLAG_GANG | ABD_FLAG_OWNER; list_create(&ABD_GANG(abd).abd_gang_chain, sizeof (abd_t), offsetof(abd_t, abd_gang_link)); - zfs_refcount_create(&abd->abd_children); return (abd); } /* * Add a child gang ABD to a parent gang ABDs chained list. */ static void abd_gang_add_gang(abd_t *pabd, abd_t *cabd, boolean_t free_on_free) { ASSERT(abd_is_gang(pabd)); ASSERT(abd_is_gang(cabd)); if (free_on_free) { /* * If the parent is responsible for freeing the child gang - * ABD we will just splice the childs children ABD list to - * the parents list and immediately free the child gang ABD + * ABD we will just splice the child's children ABD list to + * the parent's list and immediately free the child gang ABD * struct. The parent gang ABDs children from the child gang * will retain all the free_on_free settings after being * added to the parents list. */ pabd->abd_size += cabd->abd_size; list_move_tail(&ABD_GANG(pabd).abd_gang_chain, &ABD_GANG(cabd).abd_gang_chain); ASSERT(list_is_empty(&ABD_GANG(cabd).abd_gang_chain)); abd_verify(pabd); abd_free_struct(cabd); } else { for (abd_t *child = list_head(&ABD_GANG(cabd).abd_gang_chain); child != NULL; child = list_next(&ABD_GANG(cabd).abd_gang_chain, child)) { /* * We always pass B_FALSE for free_on_free as it is the * original child gang ABDs responsibilty to determine * if any of its child ABDs should be free'd on the call * to abd_free(). */ abd_gang_add(pabd, child, B_FALSE); } abd_verify(pabd); } } /* * Add a child ABD to a gang ABD's chained list. */ void abd_gang_add(abd_t *pabd, abd_t *cabd, boolean_t free_on_free) { ASSERT(abd_is_gang(pabd)); abd_t *child_abd = NULL; /* * If the child being added is a gang ABD, we will add the - * childs ABDs to the parent gang ABD. This alllows us to account + * child's ABDs to the parent gang ABD. This allows us to account * for the offset correctly in the parent gang ABD. */ if (abd_is_gang(cabd)) { ASSERT(!list_link_active(&cabd->abd_gang_link)); ASSERT(!list_is_empty(&ABD_GANG(cabd).abd_gang_chain)); return (abd_gang_add_gang(pabd, cabd, free_on_free)); } ASSERT(!abd_is_gang(cabd)); /* * In order to verify that an ABD is not already part of * another gang ABD, we must lock the child ABD's abd_mtx * to check its abd_gang_link status. We unlock the abd_mtx * only after it is has been added to a gang ABD, which * will update the abd_gang_link's status. See comment below * for how an ABD can be in multiple gang ABD's simultaneously. */ mutex_enter(&cabd->abd_mtx); if (list_link_active(&cabd->abd_gang_link)) { /* * If the child ABD is already part of another * gang ABD then we must allocate a new * ABD to use a separate link. We mark the newly * allocated ABD with ABD_FLAG_GANG_FREE, before * adding it to the gang ABD's list, to make the * gang ABD aware that it is responsible to call * abd_put(). We use abd_get_offset() in order * to just allocate a new ABD but avoid copying the * data over into the newly allocated ABD. * * An ABD may become part of multiple gang ABD's. For * example, when writing ditto bocks, the same ABD * is used to write 2 or 3 locations with 2 or 3 * zio_t's. Each of the zio's may be aggregated with * different adjacent zio's. zio aggregation uses gang * zio's, so the single ABD can become part of multiple * gang zio's. * * The ASSERT below is to make sure that if * free_on_free is passed as B_TRUE, the ABD can * not be in multiple gang ABD's. The gang ABD * can not be responsible for cleaning up the child * ABD memory allocation if the ABD can be in * multiple gang ABD's at one time. */ ASSERT3B(free_on_free, ==, B_FALSE); child_abd = abd_get_offset(cabd, 0); child_abd->abd_flags |= ABD_FLAG_GANG_FREE; } else { child_abd = cabd; if (free_on_free) child_abd->abd_flags |= ABD_FLAG_GANG_FREE; } ASSERT3P(child_abd, !=, NULL); list_insert_tail(&ABD_GANG(pabd).abd_gang_chain, child_abd); mutex_exit(&cabd->abd_mtx); pabd->abd_size += child_abd->abd_size; } /* * Locate the ABD for the supplied offset in the gang ABD. * Return a new offset relative to the returned ABD. */ abd_t * abd_gang_get_offset(abd_t *abd, size_t *off) { abd_t *cabd; ASSERT(abd_is_gang(abd)); ASSERT3U(*off, <, abd->abd_size); for (cabd = list_head(&ABD_GANG(abd).abd_gang_chain); cabd != NULL; cabd = list_next(&ABD_GANG(abd).abd_gang_chain, cabd)) { if (*off >= cabd->abd_size) *off -= cabd->abd_size; else return (cabd); } VERIFY3P(cabd, !=, NULL); return (cabd); } /* - * Allocate a new ABD to point to offset off of sabd. It shares the underlying - * buffer data with sabd. Use abd_put() to free. sabd must not be freed while - * any derived ABDs exist. + * Allocate a new ABD, using the provided struct (if non-NULL, and if + * circumstances allow - otherwise allocate the struct). The returned ABD will + * point to offset off of sabd. It shares the underlying buffer data with sabd. + * Use abd_free() to free. sabd must not be freed while any derived ABDs exist. */ static abd_t * -abd_get_offset_impl(abd_t *sabd, size_t off, size_t size) +abd_get_offset_impl(abd_t *abd, abd_t *sabd, size_t off, size_t size) { - abd_t *abd = NULL; - abd_verify(sabd); - ASSERT3U(off, <=, sabd->abd_size); + ASSERT3U(off + size, <=, sabd->abd_size); if (abd_is_linear(sabd)) { - abd = abd_alloc_struct(0); - + if (abd == NULL) + abd = abd_alloc_struct(0); /* * Even if this buf is filesystem metadata, we only track that * if we own the underlying data buffer, which is not true in * this case. Therefore, we don't ever use ABD_FLAG_META here. */ - abd->abd_flags = ABD_FLAG_LINEAR; + abd->abd_flags |= ABD_FLAG_LINEAR; ABD_LINEAR_BUF(abd) = (char *)ABD_LINEAR_BUF(sabd) + off; } else if (abd_is_gang(sabd)) { size_t left = size; - abd = abd_alloc_gang_abd(); + if (abd == NULL) { + abd = abd_alloc_gang(); + } else { + abd->abd_flags |= ABD_FLAG_GANG; + list_create(&ABD_GANG(abd).abd_gang_chain, + sizeof (abd_t), offsetof(abd_t, abd_gang_link)); + } + abd->abd_flags &= ~ABD_FLAG_OWNER; for (abd_t *cabd = abd_gang_get_offset(sabd, &off); cabd != NULL && left > 0; cabd = list_next(&ABD_GANG(sabd).abd_gang_chain, cabd)) { int csize = MIN(left, cabd->abd_size - off); - abd_t *nabd = abd_get_offset_impl(cabd, off, csize); - abd_gang_add(abd, nabd, B_FALSE); + abd_t *nabd = abd_get_offset_size(cabd, off, csize); + abd_gang_add(abd, nabd, B_TRUE); left -= csize; off = 0; } ASSERT3U(left, ==, 0); } else { - abd = abd_get_offset_scatter(sabd, off); + abd = abd_get_offset_scatter(abd, sabd, off); } abd->abd_size = size; abd->abd_parent = sabd; - zfs_refcount_create(&abd->abd_children); (void) zfs_refcount_add_many(&sabd->abd_children, abd->abd_size, abd); return (abd); } +/* + * Like abd_get_offset_size(), but memory for the abd_t is provided by the + * caller. Using this routine can improve performance by avoiding the cost + * of allocating memory for the abd_t struct, and updating the abd stats. + * Usually, the provided abd is returned, but in some circumstances (FreeBSD, + * if sabd is scatter and size is more than 2 pages) a new abd_t may need to + * be allocated. Therefore callers should be careful to use the returned + * abd_t*. + */ +abd_t * +abd_get_offset_struct(abd_t *abd, abd_t *sabd, size_t off, size_t size) +{ + abd_init_struct(abd); + return (abd_get_offset_impl(abd, sabd, off, size)); +} + abd_t * abd_get_offset(abd_t *sabd, size_t off) { size_t size = sabd->abd_size > off ? sabd->abd_size - off : 0; VERIFY3U(size, >, 0); - return (abd_get_offset_impl(sabd, off, size)); + return (abd_get_offset_impl(NULL, sabd, off, size)); } abd_t * abd_get_offset_size(abd_t *sabd, size_t off, size_t size) { ASSERT3U(off + size, <=, sabd->abd_size); - return (abd_get_offset_impl(sabd, off, size)); + return (abd_get_offset_impl(NULL, sabd, off, size)); } /* * Return a size scatter ABD. In order to free the returned * ABD abd_put() must be called. */ abd_t * abd_get_zeros(size_t size) { ASSERT3P(abd_zero_scatter, !=, NULL); ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); return (abd_get_offset_size(abd_zero_scatter, 0, size)); } /* * Allocate a linear ABD structure for buf. You must free this with abd_put() * since the resulting ABD doesn't own its own buffer. */ abd_t * abd_get_from_buf(void *buf, size_t size) { abd_t *abd = abd_alloc_struct(0); VERIFY3U(size, <=, SPA_MAXBLOCKSIZE); /* * Even if this buf is filesystem metadata, we only track that if we * own the underlying data buffer, which is not true in this case. * Therefore, we don't ever use ABD_FLAG_META here. */ - abd->abd_flags = ABD_FLAG_LINEAR; + abd->abd_flags |= ABD_FLAG_LINEAR; abd->abd_size = size; - abd->abd_parent = NULL; - zfs_refcount_create(&abd->abd_children); ABD_LINEAR_BUF(abd) = buf; return (abd); } /* * Get the raw buffer associated with a linear ABD. */ void * abd_to_buf(abd_t *abd) { ASSERT(abd_is_linear(abd)); abd_verify(abd); return (ABD_LINEAR_BUF(abd)); } /* * Borrow a raw buffer from an ABD without copying the contents of the ABD * into the buffer. If the ABD is scattered, this will allocate a raw buffer * whose contents are undefined. To copy over the existing data in the ABD, use * abd_borrow_buf_copy() instead. */ void * abd_borrow_buf(abd_t *abd, size_t n) { void *buf; abd_verify(abd); ASSERT3U(abd->abd_size, >=, n); if (abd_is_linear(abd)) { buf = abd_to_buf(abd); } else { buf = zio_buf_alloc(n); } (void) zfs_refcount_add_many(&abd->abd_children, n, buf); return (buf); } void * abd_borrow_buf_copy(abd_t *abd, size_t n) { void *buf = abd_borrow_buf(abd, n); if (!abd_is_linear(abd)) { abd_copy_to_buf(buf, abd, n); } return (buf); } /* * Return a borrowed raw buffer to an ABD. If the ABD is scattered, this will * not change the contents of the ABD and will ASSERT that you didn't modify * the buffer since it was borrowed. If you want any changes you made to buf to * be copied back to abd, use abd_return_buf_copy() instead. */ void abd_return_buf(abd_t *abd, void *buf, size_t n) { abd_verify(abd); ASSERT3U(abd->abd_size, >=, n); if (abd_is_linear(abd)) { ASSERT3P(buf, ==, abd_to_buf(abd)); } else { ASSERT0(abd_cmp_buf(abd, buf, n)); zio_buf_free(buf, n); } (void) zfs_refcount_remove_many(&abd->abd_children, n, buf); } void abd_return_buf_copy(abd_t *abd, void *buf, size_t n) { if (!abd_is_linear(abd)) { abd_copy_from_buf(abd, buf, n); } abd_return_buf(abd, buf, n); } void abd_release_ownership_of_buf(abd_t *abd) { ASSERT(abd_is_linear(abd)); ASSERT(abd->abd_flags & ABD_FLAG_OWNER); /* * abd_free() needs to handle LINEAR_PAGE ABD's specially. * Since that flag does not survive the * abd_release_ownership_of_buf() -> abd_get_from_buf() -> * abd_take_ownership_of_buf() sequence, we don't allow releasing * these "linear but not zio_[data_]buf_alloc()'ed" ABD's. */ ASSERT(!abd_is_linear_page(abd)); abd_verify(abd); abd->abd_flags &= ~ABD_FLAG_OWNER; /* Disable this flag since we no longer own the data buffer */ abd->abd_flags &= ~ABD_FLAG_META; abd_update_linear_stats(abd, ABDSTAT_DECR); } /* * Give this ABD ownership of the buffer that it's storing. Can only be used on * linear ABDs which were allocated via abd_get_from_buf(), or ones allocated * with abd_alloc_linear() which subsequently released ownership of their buf * with abd_release_ownership_of_buf(). */ void abd_take_ownership_of_buf(abd_t *abd, boolean_t is_metadata) { ASSERT(abd_is_linear(abd)); ASSERT(!(abd->abd_flags & ABD_FLAG_OWNER)); abd_verify(abd); abd->abd_flags |= ABD_FLAG_OWNER; if (is_metadata) { abd->abd_flags |= ABD_FLAG_META; } abd_update_linear_stats(abd, ABDSTAT_INCR); } /* * Initializes an abd_iter based on whether the abd is a gang ABD * or just a single ABD. */ static inline abd_t * abd_init_abd_iter(abd_t *abd, struct abd_iter *aiter, size_t off) { abd_t *cabd = NULL; if (abd_is_gang(abd)) { cabd = abd_gang_get_offset(abd, &off); if (cabd) { abd_iter_init(aiter, cabd); abd_iter_advance(aiter, off); } } else { abd_iter_init(aiter, abd); abd_iter_advance(aiter, off); } return (cabd); } /* * Advances an abd_iter. We have to be careful with gang ABD as * advancing could mean that we are at the end of a particular ABD and * must grab the ABD in the gang ABD's list. */ static inline abd_t * abd_advance_abd_iter(abd_t *abd, abd_t *cabd, struct abd_iter *aiter, size_t len) { abd_iter_advance(aiter, len); if (abd_is_gang(abd) && abd_iter_at_end(aiter)) { ASSERT3P(cabd, !=, NULL); cabd = list_next(&ABD_GANG(abd).abd_gang_chain, cabd); if (cabd) { abd_iter_init(aiter, cabd); abd_iter_advance(aiter, 0); } } return (cabd); } int abd_iterate_func(abd_t *abd, size_t off, size_t size, abd_iter_func_t *func, void *private) { struct abd_iter aiter; int ret = 0; if (size == 0) return (0); abd_verify(abd); ASSERT3U(off + size, <=, abd->abd_size); - boolean_t abd_multi = abd_is_gang(abd); + boolean_t gang = abd_is_gang(abd); abd_t *c_abd = abd_init_abd_iter(abd, &aiter, off); while (size > 0) { /* If we are at the end of the gang ABD we are done */ - if (abd_multi && !c_abd) + if (gang && !c_abd) break; abd_iter_map(&aiter); size_t len = MIN(aiter.iter_mapsize, size); ASSERT3U(len, >, 0); ret = func(aiter.iter_mapaddr, len, private); abd_iter_unmap(&aiter); if (ret != 0) break; size -= len; c_abd = abd_advance_abd_iter(abd, c_abd, &aiter, len); } return (ret); } struct buf_arg { void *arg_buf; }; static int abd_copy_to_buf_off_cb(void *buf, size_t size, void *private) { struct buf_arg *ba_ptr = private; (void) memcpy(ba_ptr->arg_buf, buf, size); ba_ptr->arg_buf = (char *)ba_ptr->arg_buf + size; return (0); } /* * Copy abd to buf. (off is the offset in abd.) */ void abd_copy_to_buf_off(void *buf, abd_t *abd, size_t off, size_t size) { struct buf_arg ba_ptr = { buf }; (void) abd_iterate_func(abd, off, size, abd_copy_to_buf_off_cb, &ba_ptr); } static int abd_cmp_buf_off_cb(void *buf, size_t size, void *private) { int ret; struct buf_arg *ba_ptr = private; ret = memcmp(buf, ba_ptr->arg_buf, size); ba_ptr->arg_buf = (char *)ba_ptr->arg_buf + size; return (ret); } /* * Compare the contents of abd to buf. (off is the offset in abd.) */ int abd_cmp_buf_off(abd_t *abd, const void *buf, size_t off, size_t size) { struct buf_arg ba_ptr = { (void *) buf }; return (abd_iterate_func(abd, off, size, abd_cmp_buf_off_cb, &ba_ptr)); } static int abd_copy_from_buf_off_cb(void *buf, size_t size, void *private) { struct buf_arg *ba_ptr = private; (void) memcpy(buf, ba_ptr->arg_buf, size); ba_ptr->arg_buf = (char *)ba_ptr->arg_buf + size; return (0); } /* * Copy from buf to abd. (off is the offset in abd.) */ void abd_copy_from_buf_off(abd_t *abd, const void *buf, size_t off, size_t size) { struct buf_arg ba_ptr = { (void *) buf }; (void) abd_iterate_func(abd, off, size, abd_copy_from_buf_off_cb, &ba_ptr); } /*ARGSUSED*/ static int abd_zero_off_cb(void *buf, size_t size, void *private) { (void) memset(buf, 0, size); return (0); } /* * Zero out the abd from a particular offset to the end. */ void abd_zero_off(abd_t *abd, size_t off, size_t size) { (void) abd_iterate_func(abd, off, size, abd_zero_off_cb, NULL); } /* * Iterate over two ABDs and call func incrementally on the two ABDs' data in * equal-sized chunks (passed to func as raw buffers). func could be called many * times during this iteration. */ int abd_iterate_func2(abd_t *dabd, abd_t *sabd, size_t doff, size_t soff, size_t size, abd_iter_func2_t *func, void *private) { int ret = 0; struct abd_iter daiter, saiter; boolean_t dabd_is_gang_abd, sabd_is_gang_abd; abd_t *c_dabd, *c_sabd; if (size == 0) return (0); abd_verify(dabd); abd_verify(sabd); ASSERT3U(doff + size, <=, dabd->abd_size); ASSERT3U(soff + size, <=, sabd->abd_size); dabd_is_gang_abd = abd_is_gang(dabd); sabd_is_gang_abd = abd_is_gang(sabd); c_dabd = abd_init_abd_iter(dabd, &daiter, doff); c_sabd = abd_init_abd_iter(sabd, &saiter, soff); while (size > 0) { /* if we are at the end of the gang ABD we are done */ if ((dabd_is_gang_abd && !c_dabd) || (sabd_is_gang_abd && !c_sabd)) break; abd_iter_map(&daiter); abd_iter_map(&saiter); size_t dlen = MIN(daiter.iter_mapsize, size); size_t slen = MIN(saiter.iter_mapsize, size); size_t len = MIN(dlen, slen); ASSERT(dlen > 0 || slen > 0); ret = func(daiter.iter_mapaddr, saiter.iter_mapaddr, len, private); abd_iter_unmap(&saiter); abd_iter_unmap(&daiter); if (ret != 0) break; size -= len; c_dabd = abd_advance_abd_iter(dabd, c_dabd, &daiter, len); c_sabd = abd_advance_abd_iter(sabd, c_sabd, &saiter, len); } return (ret); } /*ARGSUSED*/ static int abd_copy_off_cb(void *dbuf, void *sbuf, size_t size, void *private) { (void) memcpy(dbuf, sbuf, size); return (0); } /* * Copy from sabd to dabd starting from soff and doff. */ void abd_copy_off(abd_t *dabd, abd_t *sabd, size_t doff, size_t soff, size_t size) { (void) abd_iterate_func2(dabd, sabd, doff, soff, size, abd_copy_off_cb, NULL); } /*ARGSUSED*/ static int abd_cmp_cb(void *bufa, void *bufb, size_t size, void *private) { return (memcmp(bufa, bufb, size)); } /* * Compares the contents of two ABDs. */ int abd_cmp(abd_t *dabd, abd_t *sabd) { ASSERT3U(dabd->abd_size, ==, sabd->abd_size); return (abd_iterate_func2(dabd, sabd, 0, 0, dabd->abd_size, abd_cmp_cb, NULL)); } /* * Iterate over code ABDs and a data ABD and call @func_raidz_gen. * * @cabds parity ABDs, must have equal size * @dabd data ABD. Can be NULL (in this case @dsize = 0) * @func_raidz_gen should be implemented so that its behaviour * is the same when taking linear and when taking scatter */ void abd_raidz_gen_iterate(abd_t **cabds, abd_t *dabd, ssize_t csize, ssize_t dsize, const unsigned parity, void (*func_raidz_gen)(void **, const void *, size_t, size_t)) { int i; ssize_t len, dlen; struct abd_iter caiters[3]; struct abd_iter daiter = {0}; void *caddrs[3]; unsigned long flags __maybe_unused = 0; abd_t *c_cabds[3]; abd_t *c_dabd = NULL; boolean_t cabds_is_gang_abd[3]; boolean_t dabd_is_gang_abd = B_FALSE; ASSERT3U(parity, <=, 3); for (i = 0; i < parity; i++) { cabds_is_gang_abd[i] = abd_is_gang(cabds[i]); c_cabds[i] = abd_init_abd_iter(cabds[i], &caiters[i], 0); } if (dabd) { dabd_is_gang_abd = abd_is_gang(dabd); c_dabd = abd_init_abd_iter(dabd, &daiter, 0); } ASSERT3S(dsize, >=, 0); abd_enter_critical(flags); while (csize > 0) { /* if we are at the end of the gang ABD we are done */ if (dabd_is_gang_abd && !c_dabd) break; for (i = 0; i < parity; i++) { /* * If we are at the end of the gang ABD we are * done. */ if (cabds_is_gang_abd[i] && !c_cabds[i]) break; abd_iter_map(&caiters[i]); caddrs[i] = caiters[i].iter_mapaddr; } len = csize; if (dabd && dsize > 0) abd_iter_map(&daiter); switch (parity) { case 3: len = MIN(caiters[2].iter_mapsize, len); /* falls through */ case 2: len = MIN(caiters[1].iter_mapsize, len); /* falls through */ case 1: len = MIN(caiters[0].iter_mapsize, len); } /* must be progressive */ ASSERT3S(len, >, 0); if (dabd && dsize > 0) { /* this needs precise iter.length */ len = MIN(daiter.iter_mapsize, len); dlen = len; } else dlen = 0; /* must be progressive */ ASSERT3S(len, >, 0); /* * The iterated function likely will not do well if each * segment except the last one is not multiple of 512 (raidz). */ ASSERT3U(((uint64_t)len & 511ULL), ==, 0); func_raidz_gen(caddrs, daiter.iter_mapaddr, len, dlen); for (i = parity-1; i >= 0; i--) { abd_iter_unmap(&caiters[i]); c_cabds[i] = abd_advance_abd_iter(cabds[i], c_cabds[i], &caiters[i], len); } if (dabd && dsize > 0) { abd_iter_unmap(&daiter); c_dabd = abd_advance_abd_iter(dabd, c_dabd, &daiter, dlen); dsize -= dlen; } csize -= len; ASSERT3S(dsize, >=, 0); ASSERT3S(csize, >=, 0); } abd_exit_critical(flags); } /* * Iterate over code ABDs and data reconstruction target ABDs and call * @func_raidz_rec. Function maps at most 6 pages atomically. * * @cabds parity ABDs, must have equal size * @tabds rec target ABDs, at most 3 * @tsize size of data target columns * @func_raidz_rec expects syndrome data in target columns. Function * reconstructs data and overwrites target columns. */ void abd_raidz_rec_iterate(abd_t **cabds, abd_t **tabds, ssize_t tsize, const unsigned parity, void (*func_raidz_rec)(void **t, const size_t tsize, void **c, const unsigned *mul), const unsigned *mul) { int i; ssize_t len; struct abd_iter citers[3]; struct abd_iter xiters[3]; void *caddrs[3], *xaddrs[3]; unsigned long flags __maybe_unused = 0; boolean_t cabds_is_gang_abd[3]; boolean_t tabds_is_gang_abd[3]; abd_t *c_cabds[3]; abd_t *c_tabds[3]; ASSERT3U(parity, <=, 3); for (i = 0; i < parity; i++) { cabds_is_gang_abd[i] = abd_is_gang(cabds[i]); tabds_is_gang_abd[i] = abd_is_gang(tabds[i]); c_cabds[i] = abd_init_abd_iter(cabds[i], &citers[i], 0); c_tabds[i] = abd_init_abd_iter(tabds[i], &xiters[i], 0); } abd_enter_critical(flags); while (tsize > 0) { for (i = 0; i < parity; i++) { /* * If we are at the end of the gang ABD we * are done. */ if (cabds_is_gang_abd[i] && !c_cabds[i]) break; if (tabds_is_gang_abd[i] && !c_tabds[i]) break; abd_iter_map(&citers[i]); abd_iter_map(&xiters[i]); caddrs[i] = citers[i].iter_mapaddr; xaddrs[i] = xiters[i].iter_mapaddr; } len = tsize; switch (parity) { case 3: len = MIN(xiters[2].iter_mapsize, len); len = MIN(citers[2].iter_mapsize, len); /* falls through */ case 2: len = MIN(xiters[1].iter_mapsize, len); len = MIN(citers[1].iter_mapsize, len); /* falls through */ case 1: len = MIN(xiters[0].iter_mapsize, len); len = MIN(citers[0].iter_mapsize, len); } /* must be progressive */ ASSERT3S(len, >, 0); /* * The iterated function likely will not do well if each * segment except the last one is not multiple of 512 (raidz). */ ASSERT3U(((uint64_t)len & 511ULL), ==, 0); func_raidz_rec(xaddrs, len, caddrs, mul); for (i = parity-1; i >= 0; i--) { abd_iter_unmap(&xiters[i]); abd_iter_unmap(&citers[i]); c_tabds[i] = abd_advance_abd_iter(tabds[i], c_tabds[i], &xiters[i], len); c_cabds[i] = abd_advance_abd_iter(cabds[i], c_cabds[i], &citers[i], len); } tsize -= len; ASSERT3S(tsize, >=, 0); } abd_exit_critical(flags); } diff --git a/module/zfs/arc.c b/module/zfs/arc.c index b8330520fadc..9ac12fd1d43a 100644 --- a/module/zfs/arc.c +++ b/module/zfs/arc.c @@ -1,10766 +1,10766 @@ /* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. * Copyright (c) 2018, Joyent, Inc. * Copyright (c) 2011, 2020, Delphix. All rights reserved. * Copyright (c) 2014, Saso Kiselkov. All rights reserved. * Copyright (c) 2017, Nexenta Systems, Inc. All rights reserved. * Copyright (c) 2019, loli10K . All rights reserved. * Copyright (c) 2020, George Amanakis. All rights reserved. * Copyright (c) 2019, Klara Inc. * Copyright (c) 2019, Allan Jude * Copyright (c) 2020, The FreeBSD Foundation [1] * * [1] Portions of this software were developed by Allan Jude * under sponsorship from the FreeBSD Foundation. */ /* * DVA-based Adjustable Replacement Cache * * While much of the theory of operation used here is * based on the self-tuning, low overhead replacement cache * presented by Megiddo and Modha at FAST 2003, there are some * significant differences: * * 1. The Megiddo and Modha model assumes any page is evictable. * Pages in its cache cannot be "locked" into memory. This makes * the eviction algorithm simple: evict the last page in the list. * This also make the performance characteristics easy to reason * about. Our cache is not so simple. At any given moment, some * subset of the blocks in the cache are un-evictable because we * have handed out a reference to them. Blocks are only evictable * when there are no external references active. This makes * eviction far more problematic: we choose to evict the evictable * blocks that are the "lowest" in the list. * * There are times when it is not possible to evict the requested * space. In these circumstances we are unable to adjust the cache * size. To prevent the cache growing unbounded at these times we * implement a "cache throttle" that slows the flow of new data * into the cache until we can make space available. * * 2. The Megiddo and Modha model assumes a fixed cache size. * Pages are evicted when the cache is full and there is a cache * miss. Our model has a variable sized cache. It grows with * high use, but also tries to react to memory pressure from the * operating system: decreasing its size when system memory is * tight. * * 3. The Megiddo and Modha model assumes a fixed page size. All * elements of the cache are therefore exactly the same size. So * when adjusting the cache size following a cache miss, its simply * a matter of choosing a single page to evict. In our model, we * have variable sized cache blocks (ranging from 512 bytes to * 128K bytes). We therefore choose a set of blocks to evict to make * space for a cache miss that approximates as closely as possible * the space used by the new block. * * See also: "ARC: A Self-Tuning, Low Overhead Replacement Cache" * by N. Megiddo & D. Modha, FAST 2003 */ /* * The locking model: * * A new reference to a cache buffer can be obtained in two * ways: 1) via a hash table lookup using the DVA as a key, * or 2) via one of the ARC lists. The arc_read() interface * uses method 1, while the internal ARC algorithms for * adjusting the cache use method 2. We therefore provide two * types of locks: 1) the hash table lock array, and 2) the * ARC list locks. * * Buffers do not have their own mutexes, rather they rely on the * hash table mutexes for the bulk of their protection (i.e. most * fields in the arc_buf_hdr_t are protected by these mutexes). * * buf_hash_find() returns the appropriate mutex (held) when it * locates the requested buffer in the hash table. It returns * NULL for the mutex if the buffer was not in the table. * * buf_hash_remove() expects the appropriate hash mutex to be * already held before it is invoked. * * Each ARC state also has a mutex which is used to protect the * buffer list associated with the state. When attempting to * obtain a hash table lock while holding an ARC list lock you * must use: mutex_tryenter() to avoid deadlock. Also note that * the active state mutex must be held before the ghost state mutex. * * It as also possible to register a callback which is run when the * arc_meta_limit is reached and no buffers can be safely evicted. In * this case the arc user should drop a reference on some arc buffers so * they can be reclaimed and the arc_meta_limit honored. For example, * when using the ZPL each dentry holds a references on a znode. These * dentries must be pruned before the arc buffer holding the znode can * be safely evicted. * * Note that the majority of the performance stats are manipulated * with atomic operations. * * The L2ARC uses the l2ad_mtx on each vdev for the following: * * - L2ARC buflist creation * - L2ARC buflist eviction * - L2ARC write completion, which walks L2ARC buflists * - ARC header destruction, as it removes from L2ARC buflists * - ARC header release, as it removes from L2ARC buflists */ /* * ARC operation: * * Every block that is in the ARC is tracked by an arc_buf_hdr_t structure. * This structure can point either to a block that is still in the cache or to * one that is only accessible in an L2 ARC device, or it can provide * information about a block that was recently evicted. If a block is * only accessible in the L2ARC, then the arc_buf_hdr_t only has enough * information to retrieve it from the L2ARC device. This information is * stored in the l2arc_buf_hdr_t sub-structure of the arc_buf_hdr_t. A block * that is in this state cannot access the data directly. * * Blocks that are actively being referenced or have not been evicted * are cached in the L1ARC. The L1ARC (l1arc_buf_hdr_t) is a structure within * the arc_buf_hdr_t that will point to the data block in memory. A block can * only be read by a consumer if it has an l1arc_buf_hdr_t. The L1ARC * caches data in two ways -- in a list of ARC buffers (arc_buf_t) and * also in the arc_buf_hdr_t's private physical data block pointer (b_pabd). * * The L1ARC's data pointer may or may not be uncompressed. The ARC has the * ability to store the physical data (b_pabd) associated with the DVA of the * arc_buf_hdr_t. Since the b_pabd is a copy of the on-disk physical block, * it will match its on-disk compression characteristics. This behavior can be * disabled by setting 'zfs_compressed_arc_enabled' to B_FALSE. When the * compressed ARC functionality is disabled, the b_pabd will point to an * uncompressed version of the on-disk data. * * Data in the L1ARC is not accessed by consumers of the ARC directly. Each * arc_buf_hdr_t can have multiple ARC buffers (arc_buf_t) which reference it. * Each ARC buffer (arc_buf_t) is being actively accessed by a specific ARC * consumer. The ARC will provide references to this data and will keep it * cached until it is no longer in use. The ARC caches only the L1ARC's physical * data block and will evict any arc_buf_t that is no longer referenced. The * amount of memory consumed by the arc_buf_ts' data buffers can be seen via the * "overhead_size" kstat. * * Depending on the consumer, an arc_buf_t can be requested in uncompressed or * compressed form. The typical case is that consumers will want uncompressed * data, and when that happens a new data buffer is allocated where the data is * decompressed for them to use. Currently the only consumer who wants * compressed arc_buf_t's is "zfs send", when it streams data exactly as it * exists on disk. When this happens, the arc_buf_t's data buffer is shared * with the arc_buf_hdr_t. * * Here is a diagram showing an arc_buf_hdr_t referenced by two arc_buf_t's. The * first one is owned by a compressed send consumer (and therefore references * the same compressed data buffer as the arc_buf_hdr_t) and the second could be * used by any other consumer (and has its own uncompressed copy of the data * buffer). * * arc_buf_hdr_t * +-----------+ * | fields | * | common to | * | L1- and | * | L2ARC | * +-----------+ * | l2arc_buf_hdr_t * | | * +-----------+ * | l1arc_buf_hdr_t * | | arc_buf_t * | b_buf +------------>+-----------+ arc_buf_t * | b_pabd +-+ |b_next +---->+-----------+ * +-----------+ | |-----------| |b_next +-->NULL * | |b_comp = T | +-----------+ * | |b_data +-+ |b_comp = F | * | +-----------+ | |b_data +-+ * +->+------+ | +-----------+ | * compressed | | | | * data | |<--------------+ | uncompressed * +------+ compressed, | data * shared +-->+------+ * data | | * | | * +------+ * * When a consumer reads a block, the ARC must first look to see if the * arc_buf_hdr_t is cached. If the hdr is cached then the ARC allocates a new * arc_buf_t and either copies uncompressed data into a new data buffer from an * existing uncompressed arc_buf_t, decompresses the hdr's b_pabd buffer into a * new data buffer, or shares the hdr's b_pabd buffer, depending on whether the * hdr is compressed and the desired compression characteristics of the * arc_buf_t consumer. If the arc_buf_t ends up sharing data with the * arc_buf_hdr_t and both of them are uncompressed then the arc_buf_t must be * the last buffer in the hdr's b_buf list, however a shared compressed buf can * be anywhere in the hdr's list. * * The diagram below shows an example of an uncompressed ARC hdr that is * sharing its data with an arc_buf_t (note that the shared uncompressed buf is * the last element in the buf list): * * arc_buf_hdr_t * +-----------+ * | | * | | * | | * +-----------+ * l2arc_buf_hdr_t| | * | | * +-----------+ * l1arc_buf_hdr_t| | * | | arc_buf_t (shared) * | b_buf +------------>+---------+ arc_buf_t * | | |b_next +---->+---------+ * | b_pabd +-+ |---------| |b_next +-->NULL * +-----------+ | | | +---------+ * | |b_data +-+ | | * | +---------+ | |b_data +-+ * +->+------+ | +---------+ | * | | | | * uncompressed | | | | * data +------+ | | * ^ +->+------+ | * | uncompressed | | | * | data | | | * | +------+ | * +---------------------------------+ * * Writing to the ARC requires that the ARC first discard the hdr's b_pabd * since the physical block is about to be rewritten. The new data contents * will be contained in the arc_buf_t. As the I/O pipeline performs the write, * it may compress the data before writing it to disk. The ARC will be called * with the transformed data and will bcopy the transformed on-disk block into * a newly allocated b_pabd. Writes are always done into buffers which have * either been loaned (and hence are new and don't have other readers) or * buffers which have been released (and hence have their own hdr, if there * were originally other readers of the buf's original hdr). This ensures that * the ARC only needs to update a single buf and its hdr after a write occurs. * * When the L2ARC is in use, it will also take advantage of the b_pabd. The * L2ARC will always write the contents of b_pabd to the L2ARC. This means * that when compressed ARC is enabled that the L2ARC blocks are identical * to the on-disk block in the main data pool. This provides a significant * advantage since the ARC can leverage the bp's checksum when reading from the * L2ARC to determine if the contents are valid. However, if the compressed * ARC is disabled, then the L2ARC's block must be transformed to look * like the physical block in the main data pool before comparing the * checksum and determining its validity. * * The L1ARC has a slightly different system for storing encrypted data. * Raw (encrypted + possibly compressed) data has a few subtle differences from * data that is just compressed. The biggest difference is that it is not * possible to decrypt encrypted data (or vice-versa) if the keys aren't loaded. * The other difference is that encryption cannot be treated as a suggestion. * If a caller would prefer compressed data, but they actually wind up with * uncompressed data the worst thing that could happen is there might be a * performance hit. If the caller requests encrypted data, however, we must be * sure they actually get it or else secret information could be leaked. Raw * data is stored in hdr->b_crypt_hdr.b_rabd. An encrypted header, therefore, * may have both an encrypted version and a decrypted version of its data at * once. When a caller needs a raw arc_buf_t, it is allocated and the data is * copied out of this header. To avoid complications with b_pabd, raw buffers * cannot be shared. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifndef _KERNEL /* set with ZFS_DEBUG=watch, to enable watchpoints on frozen buffers */ boolean_t arc_watch = B_FALSE; #endif /* * This thread's job is to keep enough free memory in the system, by * calling arc_kmem_reap_soon() plus arc_reduce_target_size(), which improves * arc_available_memory(). */ static zthr_t *arc_reap_zthr; /* * This thread's job is to keep arc_size under arc_c, by calling * arc_evict(), which improves arc_is_overflowing(). */ static zthr_t *arc_evict_zthr; static kmutex_t arc_evict_lock; static boolean_t arc_evict_needed = B_FALSE; /* * Count of bytes evicted since boot. */ static uint64_t arc_evict_count; /* * List of arc_evict_waiter_t's, representing threads waiting for the * arc_evict_count to reach specific values. */ static list_t arc_evict_waiters; /* * When arc_is_overflowing(), arc_get_data_impl() waits for this percent of * the requested amount of data to be evicted. For example, by default for * every 2KB that's evicted, 1KB of it may be "reused" by a new allocation. * Since this is above 100%, it ensures that progress is made towards getting * arc_size under arc_c. Since this is finite, it ensures that allocations * can still happen, even during the potentially long time that arc_size is * more than arc_c. */ int zfs_arc_eviction_pct = 200; /* * The number of headers to evict in arc_evict_state_impl() before * dropping the sublist lock and evicting from another sublist. A lower * value means we're more likely to evict the "correct" header (i.e. the * oldest header in the arc state), but comes with higher overhead * (i.e. more invocations of arc_evict_state_impl()). */ int zfs_arc_evict_batch_limit = 10; /* number of seconds before growing cache again */ int arc_grow_retry = 5; /* * Minimum time between calls to arc_kmem_reap_soon(). */ int arc_kmem_cache_reap_retry_ms = 1000; /* shift of arc_c for calculating overflow limit in arc_get_data_impl */ int zfs_arc_overflow_shift = 8; /* shift of arc_c for calculating both min and max arc_p */ int arc_p_min_shift = 4; /* log2(fraction of arc to reclaim) */ int arc_shrink_shift = 7; /* percent of pagecache to reclaim arc to */ #ifdef _KERNEL uint_t zfs_arc_pc_percent = 0; #endif /* * log2(fraction of ARC which must be free to allow growing). * I.e. If there is less than arc_c >> arc_no_grow_shift free memory, * when reading a new block into the ARC, we will evict an equal-sized block * from the ARC. * * This must be less than arc_shrink_shift, so that when we shrink the ARC, * we will still not allow it to grow. */ int arc_no_grow_shift = 5; /* * minimum lifespan of a prefetch block in clock ticks * (initialized in arc_init()) */ static int arc_min_prefetch_ms; static int arc_min_prescient_prefetch_ms; /* * If this percent of memory is free, don't throttle. */ int arc_lotsfree_percent = 10; /* * The arc has filled available memory and has now warmed up. */ boolean_t arc_warm; /* * These tunables are for performance analysis. */ unsigned long zfs_arc_max = 0; unsigned long zfs_arc_min = 0; unsigned long zfs_arc_meta_limit = 0; unsigned long zfs_arc_meta_min = 0; unsigned long zfs_arc_dnode_limit = 0; unsigned long zfs_arc_dnode_reduce_percent = 10; int zfs_arc_grow_retry = 0; int zfs_arc_shrink_shift = 0; int zfs_arc_p_min_shift = 0; int zfs_arc_average_blocksize = 8 * 1024; /* 8KB */ /* * ARC dirty data constraints for arc_tempreserve_space() throttle. */ unsigned long zfs_arc_dirty_limit_percent = 50; /* total dirty data limit */ unsigned long zfs_arc_anon_limit_percent = 25; /* anon block dirty limit */ unsigned long zfs_arc_pool_dirty_percent = 20; /* each pool's anon allowance */ /* * Enable or disable compressed arc buffers. */ int zfs_compressed_arc_enabled = B_TRUE; /* * ARC will evict meta buffers that exceed arc_meta_limit. This * tunable make arc_meta_limit adjustable for different workloads. */ unsigned long zfs_arc_meta_limit_percent = 75; /* * Percentage that can be consumed by dnodes of ARC meta buffers. */ unsigned long zfs_arc_dnode_limit_percent = 10; /* * These tunables are Linux specific */ unsigned long zfs_arc_sys_free = 0; int zfs_arc_min_prefetch_ms = 0; int zfs_arc_min_prescient_prefetch_ms = 0; int zfs_arc_p_dampener_disable = 1; int zfs_arc_meta_prune = 10000; int zfs_arc_meta_strategy = ARC_STRATEGY_META_BALANCED; int zfs_arc_meta_adjust_restarts = 4096; int zfs_arc_lotsfree_percent = 10; /* The 6 states: */ arc_state_t ARC_anon; arc_state_t ARC_mru; arc_state_t ARC_mru_ghost; arc_state_t ARC_mfu; arc_state_t ARC_mfu_ghost; arc_state_t ARC_l2c_only; arc_stats_t arc_stats = { { "hits", KSTAT_DATA_UINT64 }, { "misses", KSTAT_DATA_UINT64 }, { "demand_data_hits", KSTAT_DATA_UINT64 }, { "demand_data_misses", KSTAT_DATA_UINT64 }, { "demand_metadata_hits", KSTAT_DATA_UINT64 }, { "demand_metadata_misses", KSTAT_DATA_UINT64 }, { "prefetch_data_hits", KSTAT_DATA_UINT64 }, { "prefetch_data_misses", KSTAT_DATA_UINT64 }, { "prefetch_metadata_hits", KSTAT_DATA_UINT64 }, { "prefetch_metadata_misses", KSTAT_DATA_UINT64 }, { "mru_hits", KSTAT_DATA_UINT64 }, { "mru_ghost_hits", KSTAT_DATA_UINT64 }, { "mfu_hits", KSTAT_DATA_UINT64 }, { "mfu_ghost_hits", KSTAT_DATA_UINT64 }, { "deleted", KSTAT_DATA_UINT64 }, { "mutex_miss", KSTAT_DATA_UINT64 }, { "access_skip", KSTAT_DATA_UINT64 }, { "evict_skip", KSTAT_DATA_UINT64 }, { "evict_not_enough", KSTAT_DATA_UINT64 }, { "evict_l2_cached", KSTAT_DATA_UINT64 }, { "evict_l2_eligible", KSTAT_DATA_UINT64 }, { "evict_l2_eligible_mfu", KSTAT_DATA_UINT64 }, { "evict_l2_eligible_mru", KSTAT_DATA_UINT64 }, { "evict_l2_ineligible", KSTAT_DATA_UINT64 }, { "evict_l2_skip", KSTAT_DATA_UINT64 }, { "hash_elements", KSTAT_DATA_UINT64 }, { "hash_elements_max", KSTAT_DATA_UINT64 }, { "hash_collisions", KSTAT_DATA_UINT64 }, { "hash_chains", KSTAT_DATA_UINT64 }, { "hash_chain_max", KSTAT_DATA_UINT64 }, { "p", KSTAT_DATA_UINT64 }, { "c", KSTAT_DATA_UINT64 }, { "c_min", KSTAT_DATA_UINT64 }, { "c_max", KSTAT_DATA_UINT64 }, { "size", KSTAT_DATA_UINT64 }, { "compressed_size", KSTAT_DATA_UINT64 }, { "uncompressed_size", KSTAT_DATA_UINT64 }, { "overhead_size", KSTAT_DATA_UINT64 }, { "hdr_size", KSTAT_DATA_UINT64 }, { "data_size", KSTAT_DATA_UINT64 }, { "metadata_size", KSTAT_DATA_UINT64 }, { "dbuf_size", KSTAT_DATA_UINT64 }, { "dnode_size", KSTAT_DATA_UINT64 }, { "bonus_size", KSTAT_DATA_UINT64 }, #if defined(COMPAT_FREEBSD11) { "other_size", KSTAT_DATA_UINT64 }, #endif { "anon_size", KSTAT_DATA_UINT64 }, { "anon_evictable_data", KSTAT_DATA_UINT64 }, { "anon_evictable_metadata", KSTAT_DATA_UINT64 }, { "mru_size", KSTAT_DATA_UINT64 }, { "mru_evictable_data", KSTAT_DATA_UINT64 }, { "mru_evictable_metadata", KSTAT_DATA_UINT64 }, { "mru_ghost_size", KSTAT_DATA_UINT64 }, { "mru_ghost_evictable_data", KSTAT_DATA_UINT64 }, { "mru_ghost_evictable_metadata", KSTAT_DATA_UINT64 }, { "mfu_size", KSTAT_DATA_UINT64 }, { "mfu_evictable_data", KSTAT_DATA_UINT64 }, { "mfu_evictable_metadata", KSTAT_DATA_UINT64 }, { "mfu_ghost_size", KSTAT_DATA_UINT64 }, { "mfu_ghost_evictable_data", KSTAT_DATA_UINT64 }, { "mfu_ghost_evictable_metadata", KSTAT_DATA_UINT64 }, { "l2_hits", KSTAT_DATA_UINT64 }, { "l2_misses", KSTAT_DATA_UINT64 }, { "l2_prefetch_asize", KSTAT_DATA_UINT64 }, { "l2_mru_asize", KSTAT_DATA_UINT64 }, { "l2_mfu_asize", KSTAT_DATA_UINT64 }, { "l2_bufc_data_asize", KSTAT_DATA_UINT64 }, { "l2_bufc_metadata_asize", KSTAT_DATA_UINT64 }, { "l2_feeds", KSTAT_DATA_UINT64 }, { "l2_rw_clash", KSTAT_DATA_UINT64 }, { "l2_read_bytes", KSTAT_DATA_UINT64 }, { "l2_write_bytes", KSTAT_DATA_UINT64 }, { "l2_writes_sent", KSTAT_DATA_UINT64 }, { "l2_writes_done", KSTAT_DATA_UINT64 }, { "l2_writes_error", KSTAT_DATA_UINT64 }, { "l2_writes_lock_retry", KSTAT_DATA_UINT64 }, { "l2_evict_lock_retry", KSTAT_DATA_UINT64 }, { "l2_evict_reading", KSTAT_DATA_UINT64 }, { "l2_evict_l1cached", KSTAT_DATA_UINT64 }, { "l2_free_on_write", KSTAT_DATA_UINT64 }, { "l2_abort_lowmem", KSTAT_DATA_UINT64 }, { "l2_cksum_bad", KSTAT_DATA_UINT64 }, { "l2_io_error", KSTAT_DATA_UINT64 }, { "l2_size", KSTAT_DATA_UINT64 }, { "l2_asize", KSTAT_DATA_UINT64 }, { "l2_hdr_size", KSTAT_DATA_UINT64 }, { "l2_log_blk_writes", KSTAT_DATA_UINT64 }, { "l2_log_blk_avg_asize", KSTAT_DATA_UINT64 }, { "l2_log_blk_asize", KSTAT_DATA_UINT64 }, { "l2_log_blk_count", KSTAT_DATA_UINT64 }, { "l2_data_to_meta_ratio", KSTAT_DATA_UINT64 }, { "l2_rebuild_success", KSTAT_DATA_UINT64 }, { "l2_rebuild_unsupported", KSTAT_DATA_UINT64 }, { "l2_rebuild_io_errors", KSTAT_DATA_UINT64 }, { "l2_rebuild_dh_errors", KSTAT_DATA_UINT64 }, { "l2_rebuild_cksum_lb_errors", KSTAT_DATA_UINT64 }, { "l2_rebuild_lowmem", KSTAT_DATA_UINT64 }, { "l2_rebuild_size", KSTAT_DATA_UINT64 }, { "l2_rebuild_asize", KSTAT_DATA_UINT64 }, { "l2_rebuild_bufs", KSTAT_DATA_UINT64 }, { "l2_rebuild_bufs_precached", KSTAT_DATA_UINT64 }, { "l2_rebuild_log_blks", KSTAT_DATA_UINT64 }, { "memory_throttle_count", KSTAT_DATA_UINT64 }, { "memory_direct_count", KSTAT_DATA_UINT64 }, { "memory_indirect_count", KSTAT_DATA_UINT64 }, { "memory_all_bytes", KSTAT_DATA_UINT64 }, { "memory_free_bytes", KSTAT_DATA_UINT64 }, { "memory_available_bytes", KSTAT_DATA_INT64 }, { "arc_no_grow", KSTAT_DATA_UINT64 }, { "arc_tempreserve", KSTAT_DATA_UINT64 }, { "arc_loaned_bytes", KSTAT_DATA_UINT64 }, { "arc_prune", KSTAT_DATA_UINT64 }, { "arc_meta_used", KSTAT_DATA_UINT64 }, { "arc_meta_limit", KSTAT_DATA_UINT64 }, { "arc_dnode_limit", KSTAT_DATA_UINT64 }, { "arc_meta_max", KSTAT_DATA_UINT64 }, { "arc_meta_min", KSTAT_DATA_UINT64 }, { "async_upgrade_sync", KSTAT_DATA_UINT64 }, { "demand_hit_predictive_prefetch", KSTAT_DATA_UINT64 }, { "demand_hit_prescient_prefetch", KSTAT_DATA_UINT64 }, { "arc_need_free", KSTAT_DATA_UINT64 }, { "arc_sys_free", KSTAT_DATA_UINT64 }, { "arc_raw_size", KSTAT_DATA_UINT64 }, { "cached_only_in_progress", KSTAT_DATA_UINT64 }, { "abd_chunk_waste_size", KSTAT_DATA_UINT64 }, }; #define ARCSTAT_MAX(stat, val) { \ uint64_t m; \ while ((val) > (m = arc_stats.stat.value.ui64) && \ (m != atomic_cas_64(&arc_stats.stat.value.ui64, m, (val)))) \ continue; \ } #define ARCSTAT_MAXSTAT(stat) \ ARCSTAT_MAX(stat##_max, arc_stats.stat.value.ui64) /* * We define a macro to allow ARC hits/misses to be easily broken down by * two separate conditions, giving a total of four different subtypes for * each of hits and misses (so eight statistics total). */ #define ARCSTAT_CONDSTAT(cond1, stat1, notstat1, cond2, stat2, notstat2, stat) \ if (cond1) { \ if (cond2) { \ ARCSTAT_BUMP(arcstat_##stat1##_##stat2##_##stat); \ } else { \ ARCSTAT_BUMP(arcstat_##stat1##_##notstat2##_##stat); \ } \ } else { \ if (cond2) { \ ARCSTAT_BUMP(arcstat_##notstat1##_##stat2##_##stat); \ } else { \ ARCSTAT_BUMP(arcstat_##notstat1##_##notstat2##_##stat);\ } \ } /* * This macro allows us to use kstats as floating averages. Each time we * update this kstat, we first factor it and the update value by * ARCSTAT_AVG_FACTOR to shrink the new value's contribution to the overall * average. This macro assumes that integer loads and stores are atomic, but * is not safe for multiple writers updating the kstat in parallel (only the * last writer's update will remain). */ #define ARCSTAT_F_AVG_FACTOR 3 #define ARCSTAT_F_AVG(stat, value) \ do { \ uint64_t x = ARCSTAT(stat); \ x = x - x / ARCSTAT_F_AVG_FACTOR + \ (value) / ARCSTAT_F_AVG_FACTOR; \ ARCSTAT(stat) = x; \ _NOTE(CONSTCOND) \ } while (0) kstat_t *arc_ksp; static arc_state_t *arc_anon; static arc_state_t *arc_mru_ghost; static arc_state_t *arc_mfu_ghost; static arc_state_t *arc_l2c_only; arc_state_t *arc_mru; arc_state_t *arc_mfu; /* * There are several ARC variables that are critical to export as kstats -- * but we don't want to have to grovel around in the kstat whenever we wish to * manipulate them. For these variables, we therefore define them to be in * terms of the statistic variable. This assures that we are not introducing * the possibility of inconsistency by having shadow copies of the variables, * while still allowing the code to be readable. */ #define arc_tempreserve ARCSTAT(arcstat_tempreserve) #define arc_loaned_bytes ARCSTAT(arcstat_loaned_bytes) #define arc_meta_limit ARCSTAT(arcstat_meta_limit) /* max size for metadata */ /* max size for dnodes */ #define arc_dnode_size_limit ARCSTAT(arcstat_dnode_limit) #define arc_meta_min ARCSTAT(arcstat_meta_min) /* min size for metadata */ #define arc_meta_max ARCSTAT(arcstat_meta_max) /* max size of metadata */ #define arc_need_free ARCSTAT(arcstat_need_free) /* waiting to be evicted */ /* size of all b_rabd's in entire arc */ #define arc_raw_size ARCSTAT(arcstat_raw_size) /* compressed size of entire arc */ #define arc_compressed_size ARCSTAT(arcstat_compressed_size) /* uncompressed size of entire arc */ #define arc_uncompressed_size ARCSTAT(arcstat_uncompressed_size) /* number of bytes in the arc from arc_buf_t's */ #define arc_overhead_size ARCSTAT(arcstat_overhead_size) /* * There are also some ARC variables that we want to export, but that are * updated so often that having the canonical representation be the statistic * variable causes a performance bottleneck. We want to use aggsum_t's for these * instead, but still be able to export the kstat in the same way as before. * The solution is to always use the aggsum version, except in the kstat update * callback. */ aggsum_t arc_size; aggsum_t arc_meta_used; aggsum_t astat_data_size; aggsum_t astat_metadata_size; aggsum_t astat_dbuf_size; aggsum_t astat_dnode_size; aggsum_t astat_bonus_size; aggsum_t astat_hdr_size; aggsum_t astat_l2_hdr_size; aggsum_t astat_abd_chunk_waste_size; hrtime_t arc_growtime; list_t arc_prune_list; kmutex_t arc_prune_mtx; taskq_t *arc_prune_taskq; #define GHOST_STATE(state) \ ((state) == arc_mru_ghost || (state) == arc_mfu_ghost || \ (state) == arc_l2c_only) #define HDR_IN_HASH_TABLE(hdr) ((hdr)->b_flags & ARC_FLAG_IN_HASH_TABLE) #define HDR_IO_IN_PROGRESS(hdr) ((hdr)->b_flags & ARC_FLAG_IO_IN_PROGRESS) #define HDR_IO_ERROR(hdr) ((hdr)->b_flags & ARC_FLAG_IO_ERROR) #define HDR_PREFETCH(hdr) ((hdr)->b_flags & ARC_FLAG_PREFETCH) #define HDR_PRESCIENT_PREFETCH(hdr) \ ((hdr)->b_flags & ARC_FLAG_PRESCIENT_PREFETCH) #define HDR_COMPRESSION_ENABLED(hdr) \ ((hdr)->b_flags & ARC_FLAG_COMPRESSED_ARC) #define HDR_L2CACHE(hdr) ((hdr)->b_flags & ARC_FLAG_L2CACHE) #define HDR_L2_READING(hdr) \ (((hdr)->b_flags & ARC_FLAG_IO_IN_PROGRESS) && \ ((hdr)->b_flags & ARC_FLAG_HAS_L2HDR)) #define HDR_L2_WRITING(hdr) ((hdr)->b_flags & ARC_FLAG_L2_WRITING) #define HDR_L2_EVICTED(hdr) ((hdr)->b_flags & ARC_FLAG_L2_EVICTED) #define HDR_L2_WRITE_HEAD(hdr) ((hdr)->b_flags & ARC_FLAG_L2_WRITE_HEAD) #define HDR_PROTECTED(hdr) ((hdr)->b_flags & ARC_FLAG_PROTECTED) #define HDR_NOAUTH(hdr) ((hdr)->b_flags & ARC_FLAG_NOAUTH) #define HDR_SHARED_DATA(hdr) ((hdr)->b_flags & ARC_FLAG_SHARED_DATA) #define HDR_ISTYPE_METADATA(hdr) \ ((hdr)->b_flags & ARC_FLAG_BUFC_METADATA) #define HDR_ISTYPE_DATA(hdr) (!HDR_ISTYPE_METADATA(hdr)) #define HDR_HAS_L1HDR(hdr) ((hdr)->b_flags & ARC_FLAG_HAS_L1HDR) #define HDR_HAS_L2HDR(hdr) ((hdr)->b_flags & ARC_FLAG_HAS_L2HDR) #define HDR_HAS_RABD(hdr) \ (HDR_HAS_L1HDR(hdr) && HDR_PROTECTED(hdr) && \ (hdr)->b_crypt_hdr.b_rabd != NULL) #define HDR_ENCRYPTED(hdr) \ (HDR_PROTECTED(hdr) && DMU_OT_IS_ENCRYPTED((hdr)->b_crypt_hdr.b_ot)) #define HDR_AUTHENTICATED(hdr) \ (HDR_PROTECTED(hdr) && !DMU_OT_IS_ENCRYPTED((hdr)->b_crypt_hdr.b_ot)) /* For storing compression mode in b_flags */ #define HDR_COMPRESS_OFFSET (highbit64(ARC_FLAG_COMPRESS_0) - 1) #define HDR_GET_COMPRESS(hdr) ((enum zio_compress)BF32_GET((hdr)->b_flags, \ HDR_COMPRESS_OFFSET, SPA_COMPRESSBITS)) #define HDR_SET_COMPRESS(hdr, cmp) BF32_SET((hdr)->b_flags, \ HDR_COMPRESS_OFFSET, SPA_COMPRESSBITS, (cmp)); #define ARC_BUF_LAST(buf) ((buf)->b_next == NULL) #define ARC_BUF_SHARED(buf) ((buf)->b_flags & ARC_BUF_FLAG_SHARED) #define ARC_BUF_COMPRESSED(buf) ((buf)->b_flags & ARC_BUF_FLAG_COMPRESSED) #define ARC_BUF_ENCRYPTED(buf) ((buf)->b_flags & ARC_BUF_FLAG_ENCRYPTED) /* * Other sizes */ #define HDR_FULL_CRYPT_SIZE ((int64_t)sizeof (arc_buf_hdr_t)) #define HDR_FULL_SIZE ((int64_t)offsetof(arc_buf_hdr_t, b_crypt_hdr)) #define HDR_L2ONLY_SIZE ((int64_t)offsetof(arc_buf_hdr_t, b_l1hdr)) /* * Hash table routines */ #define HT_LOCK_ALIGN 64 #define HT_LOCK_PAD (P2NPHASE(sizeof (kmutex_t), (HT_LOCK_ALIGN))) struct ht_lock { kmutex_t ht_lock; #ifdef _KERNEL unsigned char pad[HT_LOCK_PAD]; #endif }; #define BUF_LOCKS 8192 typedef struct buf_hash_table { uint64_t ht_mask; arc_buf_hdr_t **ht_table; struct ht_lock ht_locks[BUF_LOCKS]; } buf_hash_table_t; static buf_hash_table_t buf_hash_table; #define BUF_HASH_INDEX(spa, dva, birth) \ (buf_hash(spa, dva, birth) & buf_hash_table.ht_mask) #define BUF_HASH_LOCK_NTRY(idx) (buf_hash_table.ht_locks[idx & (BUF_LOCKS-1)]) #define BUF_HASH_LOCK(idx) (&(BUF_HASH_LOCK_NTRY(idx).ht_lock)) #define HDR_LOCK(hdr) \ (BUF_HASH_LOCK(BUF_HASH_INDEX(hdr->b_spa, &hdr->b_dva, hdr->b_birth))) uint64_t zfs_crc64_table[256]; /* * Level 2 ARC */ #define L2ARC_WRITE_SIZE (8 * 1024 * 1024) /* initial write max */ #define L2ARC_HEADROOM 2 /* num of writes */ /* * If we discover during ARC scan any buffers to be compressed, we boost * our headroom for the next scanning cycle by this percentage multiple. */ #define L2ARC_HEADROOM_BOOST 200 #define L2ARC_FEED_SECS 1 /* caching interval secs */ #define L2ARC_FEED_MIN_MS 200 /* min caching interval ms */ /* * We can feed L2ARC from two states of ARC buffers, mru and mfu, * and each of the state has two types: data and metadata. */ #define L2ARC_FEED_TYPES 4 #define l2arc_writes_sent ARCSTAT(arcstat_l2_writes_sent) #define l2arc_writes_done ARCSTAT(arcstat_l2_writes_done) /* L2ARC Performance Tunables */ unsigned long l2arc_write_max = L2ARC_WRITE_SIZE; /* def max write size */ unsigned long l2arc_write_boost = L2ARC_WRITE_SIZE; /* extra warmup write */ unsigned long l2arc_headroom = L2ARC_HEADROOM; /* # of dev writes */ unsigned long l2arc_headroom_boost = L2ARC_HEADROOM_BOOST; unsigned long l2arc_feed_secs = L2ARC_FEED_SECS; /* interval seconds */ unsigned long l2arc_feed_min_ms = L2ARC_FEED_MIN_MS; /* min interval msecs */ int l2arc_noprefetch = B_TRUE; /* don't cache prefetch bufs */ int l2arc_feed_again = B_TRUE; /* turbo warmup */ int l2arc_norw = B_FALSE; /* no reads during writes */ int l2arc_meta_percent = 33; /* limit on headers size */ /* * L2ARC Internals */ static list_t L2ARC_dev_list; /* device list */ static list_t *l2arc_dev_list; /* device list pointer */ static kmutex_t l2arc_dev_mtx; /* device list mutex */ static l2arc_dev_t *l2arc_dev_last; /* last device used */ static list_t L2ARC_free_on_write; /* free after write buf list */ static list_t *l2arc_free_on_write; /* free after write list ptr */ static kmutex_t l2arc_free_on_write_mtx; /* mutex for list */ static uint64_t l2arc_ndev; /* number of devices */ typedef struct l2arc_read_callback { arc_buf_hdr_t *l2rcb_hdr; /* read header */ blkptr_t l2rcb_bp; /* original blkptr */ zbookmark_phys_t l2rcb_zb; /* original bookmark */ int l2rcb_flags; /* original flags */ abd_t *l2rcb_abd; /* temporary buffer */ } l2arc_read_callback_t; typedef struct l2arc_data_free { /* protected by l2arc_free_on_write_mtx */ abd_t *l2df_abd; size_t l2df_size; arc_buf_contents_t l2df_type; list_node_t l2df_list_node; } l2arc_data_free_t; typedef enum arc_fill_flags { ARC_FILL_LOCKED = 1 << 0, /* hdr lock is held */ ARC_FILL_COMPRESSED = 1 << 1, /* fill with compressed data */ ARC_FILL_ENCRYPTED = 1 << 2, /* fill with encrypted data */ ARC_FILL_NOAUTH = 1 << 3, /* don't attempt to authenticate */ ARC_FILL_IN_PLACE = 1 << 4 /* fill in place (special case) */ } arc_fill_flags_t; static kmutex_t l2arc_feed_thr_lock; static kcondvar_t l2arc_feed_thr_cv; static uint8_t l2arc_thread_exit; static kmutex_t l2arc_rebuild_thr_lock; static kcondvar_t l2arc_rebuild_thr_cv; enum arc_hdr_alloc_flags { ARC_HDR_ALLOC_RDATA = 0x1, ARC_HDR_DO_ADAPT = 0x2, }; static abd_t *arc_get_data_abd(arc_buf_hdr_t *, uint64_t, void *, boolean_t); static void *arc_get_data_buf(arc_buf_hdr_t *, uint64_t, void *); static void arc_get_data_impl(arc_buf_hdr_t *, uint64_t, void *, boolean_t); static void arc_free_data_abd(arc_buf_hdr_t *, abd_t *, uint64_t, void *); static void arc_free_data_buf(arc_buf_hdr_t *, void *, uint64_t, void *); static void arc_free_data_impl(arc_buf_hdr_t *hdr, uint64_t size, void *tag); static void arc_hdr_free_abd(arc_buf_hdr_t *, boolean_t); static void arc_hdr_alloc_abd(arc_buf_hdr_t *, int); static void arc_access(arc_buf_hdr_t *, kmutex_t *); static void arc_buf_watch(arc_buf_t *); static arc_buf_contents_t arc_buf_type(arc_buf_hdr_t *); static uint32_t arc_bufc_to_flags(arc_buf_contents_t); static inline void arc_hdr_set_flags(arc_buf_hdr_t *hdr, arc_flags_t flags); static inline void arc_hdr_clear_flags(arc_buf_hdr_t *hdr, arc_flags_t flags); static boolean_t l2arc_write_eligible(uint64_t, arc_buf_hdr_t *); static void l2arc_read_done(zio_t *); static void l2arc_do_free_on_write(void); static void l2arc_hdr_arcstats_update(arc_buf_hdr_t *hdr, boolean_t incr, boolean_t state_only); #define l2arc_hdr_arcstats_increment(hdr) \ l2arc_hdr_arcstats_update((hdr), B_TRUE, B_FALSE) #define l2arc_hdr_arcstats_decrement(hdr) \ l2arc_hdr_arcstats_update((hdr), B_FALSE, B_FALSE) #define l2arc_hdr_arcstats_increment_state(hdr) \ l2arc_hdr_arcstats_update((hdr), B_TRUE, B_TRUE) #define l2arc_hdr_arcstats_decrement_state(hdr) \ l2arc_hdr_arcstats_update((hdr), B_FALSE, B_TRUE) /* * l2arc_mfuonly : A ZFS module parameter that controls whether only MFU * metadata and data are cached from ARC into L2ARC. */ int l2arc_mfuonly = 0; /* * L2ARC TRIM * l2arc_trim_ahead : A ZFS module parameter that controls how much ahead of * the current write size (l2arc_write_max) we should TRIM if we * have filled the device. It is defined as a percentage of the * write size. If set to 100 we trim twice the space required to * accommodate upcoming writes. A minimum of 64MB will be trimmed. * It also enables TRIM of the whole L2ARC device upon creation or * addition to an existing pool or if the header of the device is * invalid upon importing a pool or onlining a cache device. The * default is 0, which disables TRIM on L2ARC altogether as it can * put significant stress on the underlying storage devices. This * will vary depending of how well the specific device handles * these commands. */ unsigned long l2arc_trim_ahead = 0; /* * Performance tuning of L2ARC persistence: * * l2arc_rebuild_enabled : A ZFS module parameter that controls whether adding * an L2ARC device (either at pool import or later) will attempt * to rebuild L2ARC buffer contents. * l2arc_rebuild_blocks_min_l2size : A ZFS module parameter that controls * whether log blocks are written to the L2ARC device. If the L2ARC * device is less than 1GB, the amount of data l2arc_evict() * evicts is significant compared to the amount of restored L2ARC * data. In this case do not write log blocks in L2ARC in order * not to waste space. */ int l2arc_rebuild_enabled = B_TRUE; unsigned long l2arc_rebuild_blocks_min_l2size = 1024 * 1024 * 1024; /* L2ARC persistence rebuild control routines. */ void l2arc_rebuild_vdev(vdev_t *vd, boolean_t reopen); static void l2arc_dev_rebuild_thread(void *arg); static int l2arc_rebuild(l2arc_dev_t *dev); /* L2ARC persistence read I/O routines. */ static int l2arc_dev_hdr_read(l2arc_dev_t *dev); static int l2arc_log_blk_read(l2arc_dev_t *dev, const l2arc_log_blkptr_t *this_lp, const l2arc_log_blkptr_t *next_lp, l2arc_log_blk_phys_t *this_lb, l2arc_log_blk_phys_t *next_lb, zio_t *this_io, zio_t **next_io); static zio_t *l2arc_log_blk_fetch(vdev_t *vd, const l2arc_log_blkptr_t *lp, l2arc_log_blk_phys_t *lb); static void l2arc_log_blk_fetch_abort(zio_t *zio); /* L2ARC persistence block restoration routines. */ static void l2arc_log_blk_restore(l2arc_dev_t *dev, const l2arc_log_blk_phys_t *lb, uint64_t lb_asize); static void l2arc_hdr_restore(const l2arc_log_ent_phys_t *le, l2arc_dev_t *dev); /* L2ARC persistence write I/O routines. */ static void l2arc_log_blk_commit(l2arc_dev_t *dev, zio_t *pio, l2arc_write_callback_t *cb); /* L2ARC persistence auxiliary routines. */ boolean_t l2arc_log_blkptr_valid(l2arc_dev_t *dev, const l2arc_log_blkptr_t *lbp); static boolean_t l2arc_log_blk_insert(l2arc_dev_t *dev, const arc_buf_hdr_t *ab); boolean_t l2arc_range_check_overlap(uint64_t bottom, uint64_t top, uint64_t check); static void l2arc_blk_fetch_done(zio_t *zio); static inline uint64_t l2arc_log_blk_overhead(uint64_t write_sz, l2arc_dev_t *dev); /* * We use Cityhash for this. It's fast, and has good hash properties without * requiring any large static buffers. */ static uint64_t buf_hash(uint64_t spa, const dva_t *dva, uint64_t birth) { return (cityhash4(spa, dva->dva_word[0], dva->dva_word[1], birth)); } #define HDR_EMPTY(hdr) \ ((hdr)->b_dva.dva_word[0] == 0 && \ (hdr)->b_dva.dva_word[1] == 0) #define HDR_EMPTY_OR_LOCKED(hdr) \ (HDR_EMPTY(hdr) || MUTEX_HELD(HDR_LOCK(hdr))) #define HDR_EQUAL(spa, dva, birth, hdr) \ ((hdr)->b_dva.dva_word[0] == (dva)->dva_word[0]) && \ ((hdr)->b_dva.dva_word[1] == (dva)->dva_word[1]) && \ ((hdr)->b_birth == birth) && ((hdr)->b_spa == spa) static void buf_discard_identity(arc_buf_hdr_t *hdr) { hdr->b_dva.dva_word[0] = 0; hdr->b_dva.dva_word[1] = 0; hdr->b_birth = 0; } static arc_buf_hdr_t * buf_hash_find(uint64_t spa, const blkptr_t *bp, kmutex_t **lockp) { const dva_t *dva = BP_IDENTITY(bp); uint64_t birth = BP_PHYSICAL_BIRTH(bp); uint64_t idx = BUF_HASH_INDEX(spa, dva, birth); kmutex_t *hash_lock = BUF_HASH_LOCK(idx); arc_buf_hdr_t *hdr; mutex_enter(hash_lock); for (hdr = buf_hash_table.ht_table[idx]; hdr != NULL; hdr = hdr->b_hash_next) { if (HDR_EQUAL(spa, dva, birth, hdr)) { *lockp = hash_lock; return (hdr); } } mutex_exit(hash_lock); *lockp = NULL; return (NULL); } /* * Insert an entry into the hash table. If there is already an element * equal to elem in the hash table, then the already existing element * will be returned and the new element will not be inserted. * Otherwise returns NULL. * If lockp == NULL, the caller is assumed to already hold the hash lock. */ static arc_buf_hdr_t * buf_hash_insert(arc_buf_hdr_t *hdr, kmutex_t **lockp) { uint64_t idx = BUF_HASH_INDEX(hdr->b_spa, &hdr->b_dva, hdr->b_birth); kmutex_t *hash_lock = BUF_HASH_LOCK(idx); arc_buf_hdr_t *fhdr; uint32_t i; ASSERT(!DVA_IS_EMPTY(&hdr->b_dva)); ASSERT(hdr->b_birth != 0); ASSERT(!HDR_IN_HASH_TABLE(hdr)); if (lockp != NULL) { *lockp = hash_lock; mutex_enter(hash_lock); } else { ASSERT(MUTEX_HELD(hash_lock)); } for (fhdr = buf_hash_table.ht_table[idx], i = 0; fhdr != NULL; fhdr = fhdr->b_hash_next, i++) { if (HDR_EQUAL(hdr->b_spa, &hdr->b_dva, hdr->b_birth, fhdr)) return (fhdr); } hdr->b_hash_next = buf_hash_table.ht_table[idx]; buf_hash_table.ht_table[idx] = hdr; arc_hdr_set_flags(hdr, ARC_FLAG_IN_HASH_TABLE); /* collect some hash table performance data */ if (i > 0) { ARCSTAT_BUMP(arcstat_hash_collisions); if (i == 1) ARCSTAT_BUMP(arcstat_hash_chains); ARCSTAT_MAX(arcstat_hash_chain_max, i); } ARCSTAT_BUMP(arcstat_hash_elements); ARCSTAT_MAXSTAT(arcstat_hash_elements); return (NULL); } static void buf_hash_remove(arc_buf_hdr_t *hdr) { arc_buf_hdr_t *fhdr, **hdrp; uint64_t idx = BUF_HASH_INDEX(hdr->b_spa, &hdr->b_dva, hdr->b_birth); ASSERT(MUTEX_HELD(BUF_HASH_LOCK(idx))); ASSERT(HDR_IN_HASH_TABLE(hdr)); hdrp = &buf_hash_table.ht_table[idx]; while ((fhdr = *hdrp) != hdr) { ASSERT3P(fhdr, !=, NULL); hdrp = &fhdr->b_hash_next; } *hdrp = hdr->b_hash_next; hdr->b_hash_next = NULL; arc_hdr_clear_flags(hdr, ARC_FLAG_IN_HASH_TABLE); /* collect some hash table performance data */ ARCSTAT_BUMPDOWN(arcstat_hash_elements); if (buf_hash_table.ht_table[idx] && buf_hash_table.ht_table[idx]->b_hash_next == NULL) ARCSTAT_BUMPDOWN(arcstat_hash_chains); } /* * Global data structures and functions for the buf kmem cache. */ static kmem_cache_t *hdr_full_cache; static kmem_cache_t *hdr_full_crypt_cache; static kmem_cache_t *hdr_l2only_cache; static kmem_cache_t *buf_cache; static void buf_fini(void) { int i; #if defined(_KERNEL) /* * Large allocations which do not require contiguous pages * should be using vmem_free() in the linux kernel\ */ vmem_free(buf_hash_table.ht_table, (buf_hash_table.ht_mask + 1) * sizeof (void *)); #else kmem_free(buf_hash_table.ht_table, (buf_hash_table.ht_mask + 1) * sizeof (void *)); #endif for (i = 0; i < BUF_LOCKS; i++) mutex_destroy(&buf_hash_table.ht_locks[i].ht_lock); kmem_cache_destroy(hdr_full_cache); kmem_cache_destroy(hdr_full_crypt_cache); kmem_cache_destroy(hdr_l2only_cache); kmem_cache_destroy(buf_cache); } /* * Constructor callback - called when the cache is empty * and a new buf is requested. */ /* ARGSUSED */ static int hdr_full_cons(void *vbuf, void *unused, int kmflag) { arc_buf_hdr_t *hdr = vbuf; bzero(hdr, HDR_FULL_SIZE); hdr->b_l1hdr.b_byteswap = DMU_BSWAP_NUMFUNCS; cv_init(&hdr->b_l1hdr.b_cv, NULL, CV_DEFAULT, NULL); zfs_refcount_create(&hdr->b_l1hdr.b_refcnt); mutex_init(&hdr->b_l1hdr.b_freeze_lock, NULL, MUTEX_DEFAULT, NULL); list_link_init(&hdr->b_l1hdr.b_arc_node); list_link_init(&hdr->b_l2hdr.b_l2node); multilist_link_init(&hdr->b_l1hdr.b_arc_node); arc_space_consume(HDR_FULL_SIZE, ARC_SPACE_HDRS); return (0); } /* ARGSUSED */ static int hdr_full_crypt_cons(void *vbuf, void *unused, int kmflag) { arc_buf_hdr_t *hdr = vbuf; hdr_full_cons(vbuf, unused, kmflag); bzero(&hdr->b_crypt_hdr, sizeof (hdr->b_crypt_hdr)); arc_space_consume(sizeof (hdr->b_crypt_hdr), ARC_SPACE_HDRS); return (0); } /* ARGSUSED */ static int hdr_l2only_cons(void *vbuf, void *unused, int kmflag) { arc_buf_hdr_t *hdr = vbuf; bzero(hdr, HDR_L2ONLY_SIZE); arc_space_consume(HDR_L2ONLY_SIZE, ARC_SPACE_L2HDRS); return (0); } /* ARGSUSED */ static int buf_cons(void *vbuf, void *unused, int kmflag) { arc_buf_t *buf = vbuf; bzero(buf, sizeof (arc_buf_t)); mutex_init(&buf->b_evict_lock, NULL, MUTEX_DEFAULT, NULL); arc_space_consume(sizeof (arc_buf_t), ARC_SPACE_HDRS); return (0); } /* * Destructor callback - called when a cached buf is * no longer required. */ /* ARGSUSED */ static void hdr_full_dest(void *vbuf, void *unused) { arc_buf_hdr_t *hdr = vbuf; ASSERT(HDR_EMPTY(hdr)); cv_destroy(&hdr->b_l1hdr.b_cv); zfs_refcount_destroy(&hdr->b_l1hdr.b_refcnt); mutex_destroy(&hdr->b_l1hdr.b_freeze_lock); ASSERT(!multilist_link_active(&hdr->b_l1hdr.b_arc_node)); arc_space_return(HDR_FULL_SIZE, ARC_SPACE_HDRS); } /* ARGSUSED */ static void hdr_full_crypt_dest(void *vbuf, void *unused) { arc_buf_hdr_t *hdr = vbuf; hdr_full_dest(vbuf, unused); arc_space_return(sizeof (hdr->b_crypt_hdr), ARC_SPACE_HDRS); } /* ARGSUSED */ static void hdr_l2only_dest(void *vbuf, void *unused) { arc_buf_hdr_t *hdr __maybe_unused = vbuf; ASSERT(HDR_EMPTY(hdr)); arc_space_return(HDR_L2ONLY_SIZE, ARC_SPACE_L2HDRS); } /* ARGSUSED */ static void buf_dest(void *vbuf, void *unused) { arc_buf_t *buf = vbuf; mutex_destroy(&buf->b_evict_lock); arc_space_return(sizeof (arc_buf_t), ARC_SPACE_HDRS); } static void buf_init(void) { uint64_t *ct = NULL; uint64_t hsize = 1ULL << 12; int i, j; /* * The hash table is big enough to fill all of physical memory * with an average block size of zfs_arc_average_blocksize (default 8K). * By default, the table will take up * totalmem * sizeof(void*) / 8K (1MB per GB with 8-byte pointers). */ while (hsize * zfs_arc_average_blocksize < arc_all_memory()) hsize <<= 1; retry: buf_hash_table.ht_mask = hsize - 1; #if defined(_KERNEL) /* * Large allocations which do not require contiguous pages * should be using vmem_alloc() in the linux kernel */ buf_hash_table.ht_table = vmem_zalloc(hsize * sizeof (void*), KM_SLEEP); #else buf_hash_table.ht_table = kmem_zalloc(hsize * sizeof (void*), KM_NOSLEEP); #endif if (buf_hash_table.ht_table == NULL) { ASSERT(hsize > (1ULL << 8)); hsize >>= 1; goto retry; } hdr_full_cache = kmem_cache_create("arc_buf_hdr_t_full", HDR_FULL_SIZE, 0, hdr_full_cons, hdr_full_dest, NULL, NULL, NULL, 0); hdr_full_crypt_cache = kmem_cache_create("arc_buf_hdr_t_full_crypt", HDR_FULL_CRYPT_SIZE, 0, hdr_full_crypt_cons, hdr_full_crypt_dest, NULL, NULL, NULL, 0); hdr_l2only_cache = kmem_cache_create("arc_buf_hdr_t_l2only", HDR_L2ONLY_SIZE, 0, hdr_l2only_cons, hdr_l2only_dest, NULL, NULL, NULL, 0); buf_cache = kmem_cache_create("arc_buf_t", sizeof (arc_buf_t), 0, buf_cons, buf_dest, NULL, NULL, NULL, 0); for (i = 0; i < 256; i++) for (ct = zfs_crc64_table + i, *ct = i, j = 8; j > 0; j--) *ct = (*ct >> 1) ^ (-(*ct & 1) & ZFS_CRC64_POLY); for (i = 0; i < BUF_LOCKS; i++) { mutex_init(&buf_hash_table.ht_locks[i].ht_lock, NULL, MUTEX_DEFAULT, NULL); } } #define ARC_MINTIME (hz>>4) /* 62 ms */ /* * This is the size that the buf occupies in memory. If the buf is compressed, * it will correspond to the compressed size. You should use this method of * getting the buf size unless you explicitly need the logical size. */ uint64_t arc_buf_size(arc_buf_t *buf) { return (ARC_BUF_COMPRESSED(buf) ? HDR_GET_PSIZE(buf->b_hdr) : HDR_GET_LSIZE(buf->b_hdr)); } uint64_t arc_buf_lsize(arc_buf_t *buf) { return (HDR_GET_LSIZE(buf->b_hdr)); } /* * This function will return B_TRUE if the buffer is encrypted in memory. * This buffer can be decrypted by calling arc_untransform(). */ boolean_t arc_is_encrypted(arc_buf_t *buf) { return (ARC_BUF_ENCRYPTED(buf) != 0); } /* * Returns B_TRUE if the buffer represents data that has not had its MAC * verified yet. */ boolean_t arc_is_unauthenticated(arc_buf_t *buf) { return (HDR_NOAUTH(buf->b_hdr) != 0); } void arc_get_raw_params(arc_buf_t *buf, boolean_t *byteorder, uint8_t *salt, uint8_t *iv, uint8_t *mac) { arc_buf_hdr_t *hdr = buf->b_hdr; ASSERT(HDR_PROTECTED(hdr)); bcopy(hdr->b_crypt_hdr.b_salt, salt, ZIO_DATA_SALT_LEN); bcopy(hdr->b_crypt_hdr.b_iv, iv, ZIO_DATA_IV_LEN); bcopy(hdr->b_crypt_hdr.b_mac, mac, ZIO_DATA_MAC_LEN); *byteorder = (hdr->b_l1hdr.b_byteswap == DMU_BSWAP_NUMFUNCS) ? ZFS_HOST_BYTEORDER : !ZFS_HOST_BYTEORDER; } /* * Indicates how this buffer is compressed in memory. If it is not compressed * the value will be ZIO_COMPRESS_OFF. It can be made normally readable with * arc_untransform() as long as it is also unencrypted. */ enum zio_compress arc_get_compression(arc_buf_t *buf) { return (ARC_BUF_COMPRESSED(buf) ? HDR_GET_COMPRESS(buf->b_hdr) : ZIO_COMPRESS_OFF); } /* * Return the compression algorithm used to store this data in the ARC. If ARC * compression is enabled or this is an encrypted block, this will be the same * as what's used to store it on-disk. Otherwise, this will be ZIO_COMPRESS_OFF. */ static inline enum zio_compress arc_hdr_get_compress(arc_buf_hdr_t *hdr) { return (HDR_COMPRESSION_ENABLED(hdr) ? HDR_GET_COMPRESS(hdr) : ZIO_COMPRESS_OFF); } uint8_t arc_get_complevel(arc_buf_t *buf) { return (buf->b_hdr->b_complevel); } static inline boolean_t arc_buf_is_shared(arc_buf_t *buf) { boolean_t shared = (buf->b_data != NULL && buf->b_hdr->b_l1hdr.b_pabd != NULL && abd_is_linear(buf->b_hdr->b_l1hdr.b_pabd) && buf->b_data == abd_to_buf(buf->b_hdr->b_l1hdr.b_pabd)); IMPLY(shared, HDR_SHARED_DATA(buf->b_hdr)); IMPLY(shared, ARC_BUF_SHARED(buf)); IMPLY(shared, ARC_BUF_COMPRESSED(buf) || ARC_BUF_LAST(buf)); /* * It would be nice to assert arc_can_share() too, but the "hdr isn't * already being shared" requirement prevents us from doing that. */ return (shared); } /* * Free the checksum associated with this header. If there is no checksum, this * is a no-op. */ static inline void arc_cksum_free(arc_buf_hdr_t *hdr) { ASSERT(HDR_HAS_L1HDR(hdr)); mutex_enter(&hdr->b_l1hdr.b_freeze_lock); if (hdr->b_l1hdr.b_freeze_cksum != NULL) { kmem_free(hdr->b_l1hdr.b_freeze_cksum, sizeof (zio_cksum_t)); hdr->b_l1hdr.b_freeze_cksum = NULL; } mutex_exit(&hdr->b_l1hdr.b_freeze_lock); } /* * Return true iff at least one of the bufs on hdr is not compressed. * Encrypted buffers count as compressed. */ static boolean_t arc_hdr_has_uncompressed_buf(arc_buf_hdr_t *hdr) { ASSERT(hdr->b_l1hdr.b_state == arc_anon || HDR_EMPTY_OR_LOCKED(hdr)); for (arc_buf_t *b = hdr->b_l1hdr.b_buf; b != NULL; b = b->b_next) { if (!ARC_BUF_COMPRESSED(b)) { return (B_TRUE); } } return (B_FALSE); } /* * If we've turned on the ZFS_DEBUG_MODIFY flag, verify that the buf's data * matches the checksum that is stored in the hdr. If there is no checksum, * or if the buf is compressed, this is a no-op. */ static void arc_cksum_verify(arc_buf_t *buf) { arc_buf_hdr_t *hdr = buf->b_hdr; zio_cksum_t zc; if (!(zfs_flags & ZFS_DEBUG_MODIFY)) return; if (ARC_BUF_COMPRESSED(buf)) return; ASSERT(HDR_HAS_L1HDR(hdr)); mutex_enter(&hdr->b_l1hdr.b_freeze_lock); if (hdr->b_l1hdr.b_freeze_cksum == NULL || HDR_IO_ERROR(hdr)) { mutex_exit(&hdr->b_l1hdr.b_freeze_lock); return; } fletcher_2_native(buf->b_data, arc_buf_size(buf), NULL, &zc); if (!ZIO_CHECKSUM_EQUAL(*hdr->b_l1hdr.b_freeze_cksum, zc)) panic("buffer modified while frozen!"); mutex_exit(&hdr->b_l1hdr.b_freeze_lock); } /* * This function makes the assumption that data stored in the L2ARC * will be transformed exactly as it is in the main pool. Because of * this we can verify the checksum against the reading process's bp. */ static boolean_t arc_cksum_is_equal(arc_buf_hdr_t *hdr, zio_t *zio) { ASSERT(!BP_IS_EMBEDDED(zio->io_bp)); VERIFY3U(BP_GET_PSIZE(zio->io_bp), ==, HDR_GET_PSIZE(hdr)); /* * Block pointers always store the checksum for the logical data. * If the block pointer has the gang bit set, then the checksum * it represents is for the reconstituted data and not for an * individual gang member. The zio pipeline, however, must be able to * determine the checksum of each of the gang constituents so it * treats the checksum comparison differently than what we need * for l2arc blocks. This prevents us from using the * zio_checksum_error() interface directly. Instead we must call the * zio_checksum_error_impl() so that we can ensure the checksum is * generated using the correct checksum algorithm and accounts for the * logical I/O size and not just a gang fragment. */ return (zio_checksum_error_impl(zio->io_spa, zio->io_bp, BP_GET_CHECKSUM(zio->io_bp), zio->io_abd, zio->io_size, zio->io_offset, NULL) == 0); } /* * Given a buf full of data, if ZFS_DEBUG_MODIFY is enabled this computes a * checksum and attaches it to the buf's hdr so that we can ensure that the buf * isn't modified later on. If buf is compressed or there is already a checksum * on the hdr, this is a no-op (we only checksum uncompressed bufs). */ static void arc_cksum_compute(arc_buf_t *buf) { arc_buf_hdr_t *hdr = buf->b_hdr; if (!(zfs_flags & ZFS_DEBUG_MODIFY)) return; ASSERT(HDR_HAS_L1HDR(hdr)); mutex_enter(&buf->b_hdr->b_l1hdr.b_freeze_lock); if (hdr->b_l1hdr.b_freeze_cksum != NULL || ARC_BUF_COMPRESSED(buf)) { mutex_exit(&hdr->b_l1hdr.b_freeze_lock); return; } ASSERT(!ARC_BUF_ENCRYPTED(buf)); ASSERT(!ARC_BUF_COMPRESSED(buf)); hdr->b_l1hdr.b_freeze_cksum = kmem_alloc(sizeof (zio_cksum_t), KM_SLEEP); fletcher_2_native(buf->b_data, arc_buf_size(buf), NULL, hdr->b_l1hdr.b_freeze_cksum); mutex_exit(&hdr->b_l1hdr.b_freeze_lock); arc_buf_watch(buf); } #ifndef _KERNEL void arc_buf_sigsegv(int sig, siginfo_t *si, void *unused) { panic("Got SIGSEGV at address: 0x%lx\n", (long)si->si_addr); } #endif /* ARGSUSED */ static void arc_buf_unwatch(arc_buf_t *buf) { #ifndef _KERNEL if (arc_watch) { ASSERT0(mprotect(buf->b_data, arc_buf_size(buf), PROT_READ | PROT_WRITE)); } #endif } /* ARGSUSED */ static void arc_buf_watch(arc_buf_t *buf) { #ifndef _KERNEL if (arc_watch) ASSERT0(mprotect(buf->b_data, arc_buf_size(buf), PROT_READ)); #endif } static arc_buf_contents_t arc_buf_type(arc_buf_hdr_t *hdr) { arc_buf_contents_t type; if (HDR_ISTYPE_METADATA(hdr)) { type = ARC_BUFC_METADATA; } else { type = ARC_BUFC_DATA; } VERIFY3U(hdr->b_type, ==, type); return (type); } boolean_t arc_is_metadata(arc_buf_t *buf) { return (HDR_ISTYPE_METADATA(buf->b_hdr) != 0); } static uint32_t arc_bufc_to_flags(arc_buf_contents_t type) { switch (type) { case ARC_BUFC_DATA: /* metadata field is 0 if buffer contains normal data */ return (0); case ARC_BUFC_METADATA: return (ARC_FLAG_BUFC_METADATA); default: break; } panic("undefined ARC buffer type!"); return ((uint32_t)-1); } void arc_buf_thaw(arc_buf_t *buf) { arc_buf_hdr_t *hdr = buf->b_hdr; ASSERT3P(hdr->b_l1hdr.b_state, ==, arc_anon); ASSERT(!HDR_IO_IN_PROGRESS(hdr)); arc_cksum_verify(buf); /* * Compressed buffers do not manipulate the b_freeze_cksum. */ if (ARC_BUF_COMPRESSED(buf)) return; ASSERT(HDR_HAS_L1HDR(hdr)); arc_cksum_free(hdr); arc_buf_unwatch(buf); } void arc_buf_freeze(arc_buf_t *buf) { if (!(zfs_flags & ZFS_DEBUG_MODIFY)) return; if (ARC_BUF_COMPRESSED(buf)) return; ASSERT(HDR_HAS_L1HDR(buf->b_hdr)); arc_cksum_compute(buf); } /* * The arc_buf_hdr_t's b_flags should never be modified directly. Instead, * the following functions should be used to ensure that the flags are * updated in a thread-safe way. When manipulating the flags either * the hash_lock must be held or the hdr must be undiscoverable. This * ensures that we're not racing with any other threads when updating * the flags. */ static inline void arc_hdr_set_flags(arc_buf_hdr_t *hdr, arc_flags_t flags) { ASSERT(HDR_EMPTY_OR_LOCKED(hdr)); hdr->b_flags |= flags; } static inline void arc_hdr_clear_flags(arc_buf_hdr_t *hdr, arc_flags_t flags) { ASSERT(HDR_EMPTY_OR_LOCKED(hdr)); hdr->b_flags &= ~flags; } /* * Setting the compression bits in the arc_buf_hdr_t's b_flags is * done in a special way since we have to clear and set bits * at the same time. Consumers that wish to set the compression bits * must use this function to ensure that the flags are updated in * thread-safe manner. */ static void arc_hdr_set_compress(arc_buf_hdr_t *hdr, enum zio_compress cmp) { ASSERT(HDR_EMPTY_OR_LOCKED(hdr)); /* * Holes and embedded blocks will always have a psize = 0 so * we ignore the compression of the blkptr and set the * want to uncompress them. Mark them as uncompressed. */ if (!zfs_compressed_arc_enabled || HDR_GET_PSIZE(hdr) == 0) { arc_hdr_clear_flags(hdr, ARC_FLAG_COMPRESSED_ARC); ASSERT(!HDR_COMPRESSION_ENABLED(hdr)); } else { arc_hdr_set_flags(hdr, ARC_FLAG_COMPRESSED_ARC); ASSERT(HDR_COMPRESSION_ENABLED(hdr)); } HDR_SET_COMPRESS(hdr, cmp); ASSERT3U(HDR_GET_COMPRESS(hdr), ==, cmp); } /* * Looks for another buf on the same hdr which has the data decompressed, copies * from it, and returns true. If no such buf exists, returns false. */ static boolean_t arc_buf_try_copy_decompressed_data(arc_buf_t *buf) { arc_buf_hdr_t *hdr = buf->b_hdr; boolean_t copied = B_FALSE; ASSERT(HDR_HAS_L1HDR(hdr)); ASSERT3P(buf->b_data, !=, NULL); ASSERT(!ARC_BUF_COMPRESSED(buf)); for (arc_buf_t *from = hdr->b_l1hdr.b_buf; from != NULL; from = from->b_next) { /* can't use our own data buffer */ if (from == buf) { continue; } if (!ARC_BUF_COMPRESSED(from)) { bcopy(from->b_data, buf->b_data, arc_buf_size(buf)); copied = B_TRUE; break; } } /* * There were no decompressed bufs, so there should not be a * checksum on the hdr either. */ if (zfs_flags & ZFS_DEBUG_MODIFY) EQUIV(!copied, hdr->b_l1hdr.b_freeze_cksum == NULL); return (copied); } /* * Allocates an ARC buf header that's in an evicted & L2-cached state. * This is used during l2arc reconstruction to make empty ARC buffers * which circumvent the regular disk->arc->l2arc path and instead come * into being in the reverse order, i.e. l2arc->arc. */ static arc_buf_hdr_t * arc_buf_alloc_l2only(size_t size, arc_buf_contents_t type, l2arc_dev_t *dev, dva_t dva, uint64_t daddr, int32_t psize, uint64_t birth, enum zio_compress compress, uint8_t complevel, boolean_t protected, boolean_t prefetch, arc_state_type_t arcs_state) { arc_buf_hdr_t *hdr; ASSERT(size != 0); hdr = kmem_cache_alloc(hdr_l2only_cache, KM_SLEEP); hdr->b_birth = birth; hdr->b_type = type; hdr->b_flags = 0; arc_hdr_set_flags(hdr, arc_bufc_to_flags(type) | ARC_FLAG_HAS_L2HDR); HDR_SET_LSIZE(hdr, size); HDR_SET_PSIZE(hdr, psize); arc_hdr_set_compress(hdr, compress); hdr->b_complevel = complevel; if (protected) arc_hdr_set_flags(hdr, ARC_FLAG_PROTECTED); if (prefetch) arc_hdr_set_flags(hdr, ARC_FLAG_PREFETCH); hdr->b_spa = spa_load_guid(dev->l2ad_vdev->vdev_spa); hdr->b_dva = dva; hdr->b_l2hdr.b_dev = dev; hdr->b_l2hdr.b_daddr = daddr; hdr->b_l2hdr.b_arcs_state = arcs_state; return (hdr); } /* * Return the size of the block, b_pabd, that is stored in the arc_buf_hdr_t. */ static uint64_t arc_hdr_size(arc_buf_hdr_t *hdr) { uint64_t size; if (arc_hdr_get_compress(hdr) != ZIO_COMPRESS_OFF && HDR_GET_PSIZE(hdr) > 0) { size = HDR_GET_PSIZE(hdr); } else { ASSERT3U(HDR_GET_LSIZE(hdr), !=, 0); size = HDR_GET_LSIZE(hdr); } return (size); } static int arc_hdr_authenticate(arc_buf_hdr_t *hdr, spa_t *spa, uint64_t dsobj) { int ret; uint64_t csize; uint64_t lsize = HDR_GET_LSIZE(hdr); uint64_t psize = HDR_GET_PSIZE(hdr); void *tmpbuf = NULL; abd_t *abd = hdr->b_l1hdr.b_pabd; ASSERT(HDR_EMPTY_OR_LOCKED(hdr)); ASSERT(HDR_AUTHENTICATED(hdr)); ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL); /* * The MAC is calculated on the compressed data that is stored on disk. * However, if compressed arc is disabled we will only have the * decompressed data available to us now. Compress it into a temporary * abd so we can verify the MAC. The performance overhead of this will * be relatively low, since most objects in an encrypted objset will * be encrypted (instead of authenticated) anyway. */ if (HDR_GET_COMPRESS(hdr) != ZIO_COMPRESS_OFF && !HDR_COMPRESSION_ENABLED(hdr)) { tmpbuf = zio_buf_alloc(lsize); abd = abd_get_from_buf(tmpbuf, lsize); abd_take_ownership_of_buf(abd, B_TRUE); csize = zio_compress_data(HDR_GET_COMPRESS(hdr), hdr->b_l1hdr.b_pabd, tmpbuf, lsize, hdr->b_complevel); ASSERT3U(csize, <=, psize); abd_zero_off(abd, csize, psize - csize); } /* * Authentication is best effort. We authenticate whenever the key is * available. If we succeed we clear ARC_FLAG_NOAUTH. */ if (hdr->b_crypt_hdr.b_ot == DMU_OT_OBJSET) { ASSERT3U(HDR_GET_COMPRESS(hdr), ==, ZIO_COMPRESS_OFF); ASSERT3U(lsize, ==, psize); ret = spa_do_crypt_objset_mac_abd(B_FALSE, spa, dsobj, abd, psize, hdr->b_l1hdr.b_byteswap != DMU_BSWAP_NUMFUNCS); } else { ret = spa_do_crypt_mac_abd(B_FALSE, spa, dsobj, abd, psize, hdr->b_crypt_hdr.b_mac); } if (ret == 0) arc_hdr_clear_flags(hdr, ARC_FLAG_NOAUTH); else if (ret != ENOENT) goto error; if (tmpbuf != NULL) abd_free(abd); return (0); error: if (tmpbuf != NULL) abd_free(abd); return (ret); } /* * This function will take a header that only has raw encrypted data in * b_crypt_hdr.b_rabd and decrypt it into a new buffer which is stored in * b_l1hdr.b_pabd. If designated in the header flags, this function will * also decompress the data. */ static int arc_hdr_decrypt(arc_buf_hdr_t *hdr, spa_t *spa, const zbookmark_phys_t *zb) { int ret; abd_t *cabd = NULL; void *tmp = NULL; boolean_t no_crypt = B_FALSE; boolean_t bswap = (hdr->b_l1hdr.b_byteswap != DMU_BSWAP_NUMFUNCS); ASSERT(HDR_EMPTY_OR_LOCKED(hdr)); ASSERT(HDR_ENCRYPTED(hdr)); arc_hdr_alloc_abd(hdr, ARC_HDR_DO_ADAPT); ret = spa_do_crypt_abd(B_FALSE, spa, zb, hdr->b_crypt_hdr.b_ot, B_FALSE, bswap, hdr->b_crypt_hdr.b_salt, hdr->b_crypt_hdr.b_iv, hdr->b_crypt_hdr.b_mac, HDR_GET_PSIZE(hdr), hdr->b_l1hdr.b_pabd, hdr->b_crypt_hdr.b_rabd, &no_crypt); if (ret != 0) goto error; if (no_crypt) { abd_copy(hdr->b_l1hdr.b_pabd, hdr->b_crypt_hdr.b_rabd, HDR_GET_PSIZE(hdr)); } /* * If this header has disabled arc compression but the b_pabd is * compressed after decrypting it, we need to decompress the newly * decrypted data. */ if (HDR_GET_COMPRESS(hdr) != ZIO_COMPRESS_OFF && !HDR_COMPRESSION_ENABLED(hdr)) { /* * We want to make sure that we are correctly honoring the * zfs_abd_scatter_enabled setting, so we allocate an abd here * and then loan a buffer from it, rather than allocating a * linear buffer and wrapping it in an abd later. */ cabd = arc_get_data_abd(hdr, arc_hdr_size(hdr), hdr, B_TRUE); tmp = abd_borrow_buf(cabd, arc_hdr_size(hdr)); ret = zio_decompress_data(HDR_GET_COMPRESS(hdr), hdr->b_l1hdr.b_pabd, tmp, HDR_GET_PSIZE(hdr), HDR_GET_LSIZE(hdr), &hdr->b_complevel); if (ret != 0) { abd_return_buf(cabd, tmp, arc_hdr_size(hdr)); goto error; } abd_return_buf_copy(cabd, tmp, arc_hdr_size(hdr)); arc_free_data_abd(hdr, hdr->b_l1hdr.b_pabd, arc_hdr_size(hdr), hdr); hdr->b_l1hdr.b_pabd = cabd; } return (0); error: arc_hdr_free_abd(hdr, B_FALSE); if (cabd != NULL) arc_free_data_buf(hdr, cabd, arc_hdr_size(hdr), hdr); return (ret); } /* * This function is called during arc_buf_fill() to prepare the header's * abd plaintext pointer for use. This involves authenticated protected * data and decrypting encrypted data into the plaintext abd. */ static int arc_fill_hdr_crypt(arc_buf_hdr_t *hdr, kmutex_t *hash_lock, spa_t *spa, const zbookmark_phys_t *zb, boolean_t noauth) { int ret; ASSERT(HDR_PROTECTED(hdr)); if (hash_lock != NULL) mutex_enter(hash_lock); if (HDR_NOAUTH(hdr) && !noauth) { /* * The caller requested authenticated data but our data has * not been authenticated yet. Verify the MAC now if we can. */ ret = arc_hdr_authenticate(hdr, spa, zb->zb_objset); if (ret != 0) goto error; } else if (HDR_HAS_RABD(hdr) && hdr->b_l1hdr.b_pabd == NULL) { /* * If we only have the encrypted version of the data, but the * unencrypted version was requested we take this opportunity * to store the decrypted version in the header for future use. */ ret = arc_hdr_decrypt(hdr, spa, zb); if (ret != 0) goto error; } ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL); if (hash_lock != NULL) mutex_exit(hash_lock); return (0); error: if (hash_lock != NULL) mutex_exit(hash_lock); return (ret); } /* * This function is used by the dbuf code to decrypt bonus buffers in place. * The dbuf code itself doesn't have any locking for decrypting a shared dnode * block, so we use the hash lock here to protect against concurrent calls to * arc_buf_fill(). */ static void arc_buf_untransform_in_place(arc_buf_t *buf, kmutex_t *hash_lock) { arc_buf_hdr_t *hdr = buf->b_hdr; ASSERT(HDR_ENCRYPTED(hdr)); ASSERT3U(hdr->b_crypt_hdr.b_ot, ==, DMU_OT_DNODE); ASSERT(HDR_EMPTY_OR_LOCKED(hdr)); ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL); zio_crypt_copy_dnode_bonus(hdr->b_l1hdr.b_pabd, buf->b_data, arc_buf_size(buf)); buf->b_flags &= ~ARC_BUF_FLAG_ENCRYPTED; buf->b_flags &= ~ARC_BUF_FLAG_COMPRESSED; hdr->b_crypt_hdr.b_ebufcnt -= 1; } /* * Given a buf that has a data buffer attached to it, this function will * efficiently fill the buf with data of the specified compression setting from * the hdr and update the hdr's b_freeze_cksum if necessary. If the buf and hdr * are already sharing a data buf, no copy is performed. * * If the buf is marked as compressed but uncompressed data was requested, this * will allocate a new data buffer for the buf, remove that flag, and fill the * buf with uncompressed data. You can't request a compressed buf on a hdr with * uncompressed data, and (since we haven't added support for it yet) if you * want compressed data your buf must already be marked as compressed and have * the correct-sized data buffer. */ static int arc_buf_fill(arc_buf_t *buf, spa_t *spa, const zbookmark_phys_t *zb, arc_fill_flags_t flags) { int error = 0; arc_buf_hdr_t *hdr = buf->b_hdr; boolean_t hdr_compressed = (arc_hdr_get_compress(hdr) != ZIO_COMPRESS_OFF); boolean_t compressed = (flags & ARC_FILL_COMPRESSED) != 0; boolean_t encrypted = (flags & ARC_FILL_ENCRYPTED) != 0; dmu_object_byteswap_t bswap = hdr->b_l1hdr.b_byteswap; kmutex_t *hash_lock = (flags & ARC_FILL_LOCKED) ? NULL : HDR_LOCK(hdr); ASSERT3P(buf->b_data, !=, NULL); IMPLY(compressed, hdr_compressed || ARC_BUF_ENCRYPTED(buf)); IMPLY(compressed, ARC_BUF_COMPRESSED(buf)); IMPLY(encrypted, HDR_ENCRYPTED(hdr)); IMPLY(encrypted, ARC_BUF_ENCRYPTED(buf)); IMPLY(encrypted, ARC_BUF_COMPRESSED(buf)); IMPLY(encrypted, !ARC_BUF_SHARED(buf)); /* * If the caller wanted encrypted data we just need to copy it from * b_rabd and potentially byteswap it. We won't be able to do any * further transforms on it. */ if (encrypted) { ASSERT(HDR_HAS_RABD(hdr)); abd_copy_to_buf(buf->b_data, hdr->b_crypt_hdr.b_rabd, HDR_GET_PSIZE(hdr)); goto byteswap; } /* * Adjust encrypted and authenticated headers to accommodate * the request if needed. Dnode blocks (ARC_FILL_IN_PLACE) are * allowed to fail decryption due to keys not being loaded * without being marked as an IO error. */ if (HDR_PROTECTED(hdr)) { error = arc_fill_hdr_crypt(hdr, hash_lock, spa, zb, !!(flags & ARC_FILL_NOAUTH)); if (error == EACCES && (flags & ARC_FILL_IN_PLACE) != 0) { return (error); } else if (error != 0) { if (hash_lock != NULL) mutex_enter(hash_lock); arc_hdr_set_flags(hdr, ARC_FLAG_IO_ERROR); if (hash_lock != NULL) mutex_exit(hash_lock); return (error); } } /* * There is a special case here for dnode blocks which are * decrypting their bonus buffers. These blocks may request to * be decrypted in-place. This is necessary because there may * be many dnodes pointing into this buffer and there is * currently no method to synchronize replacing the backing * b_data buffer and updating all of the pointers. Here we use * the hash lock to ensure there are no races. If the need * arises for other types to be decrypted in-place, they must * add handling here as well. */ if ((flags & ARC_FILL_IN_PLACE) != 0) { ASSERT(!hdr_compressed); ASSERT(!compressed); ASSERT(!encrypted); if (HDR_ENCRYPTED(hdr) && ARC_BUF_ENCRYPTED(buf)) { ASSERT3U(hdr->b_crypt_hdr.b_ot, ==, DMU_OT_DNODE); if (hash_lock != NULL) mutex_enter(hash_lock); arc_buf_untransform_in_place(buf, hash_lock); if (hash_lock != NULL) mutex_exit(hash_lock); /* Compute the hdr's checksum if necessary */ arc_cksum_compute(buf); } return (0); } if (hdr_compressed == compressed) { if (!arc_buf_is_shared(buf)) { abd_copy_to_buf(buf->b_data, hdr->b_l1hdr.b_pabd, arc_buf_size(buf)); } } else { ASSERT(hdr_compressed); ASSERT(!compressed); ASSERT3U(HDR_GET_LSIZE(hdr), !=, HDR_GET_PSIZE(hdr)); /* * If the buf is sharing its data with the hdr, unlink it and * allocate a new data buffer for the buf. */ if (arc_buf_is_shared(buf)) { ASSERT(ARC_BUF_COMPRESSED(buf)); /* We need to give the buf its own b_data */ buf->b_flags &= ~ARC_BUF_FLAG_SHARED; buf->b_data = arc_get_data_buf(hdr, HDR_GET_LSIZE(hdr), buf); arc_hdr_clear_flags(hdr, ARC_FLAG_SHARED_DATA); /* Previously overhead was 0; just add new overhead */ ARCSTAT_INCR(arcstat_overhead_size, HDR_GET_LSIZE(hdr)); } else if (ARC_BUF_COMPRESSED(buf)) { /* We need to reallocate the buf's b_data */ arc_free_data_buf(hdr, buf->b_data, HDR_GET_PSIZE(hdr), buf); buf->b_data = arc_get_data_buf(hdr, HDR_GET_LSIZE(hdr), buf); /* We increased the size of b_data; update overhead */ ARCSTAT_INCR(arcstat_overhead_size, HDR_GET_LSIZE(hdr) - HDR_GET_PSIZE(hdr)); } /* * Regardless of the buf's previous compression settings, it * should not be compressed at the end of this function. */ buf->b_flags &= ~ARC_BUF_FLAG_COMPRESSED; /* * Try copying the data from another buf which already has a * decompressed version. If that's not possible, it's time to * bite the bullet and decompress the data from the hdr. */ if (arc_buf_try_copy_decompressed_data(buf)) { /* Skip byteswapping and checksumming (already done) */ return (0); } else { error = zio_decompress_data(HDR_GET_COMPRESS(hdr), hdr->b_l1hdr.b_pabd, buf->b_data, HDR_GET_PSIZE(hdr), HDR_GET_LSIZE(hdr), &hdr->b_complevel); /* * Absent hardware errors or software bugs, this should * be impossible, but log it anyway so we can debug it. */ if (error != 0) { zfs_dbgmsg( "hdr %px, compress %d, psize %d, lsize %d", hdr, arc_hdr_get_compress(hdr), HDR_GET_PSIZE(hdr), HDR_GET_LSIZE(hdr)); if (hash_lock != NULL) mutex_enter(hash_lock); arc_hdr_set_flags(hdr, ARC_FLAG_IO_ERROR); if (hash_lock != NULL) mutex_exit(hash_lock); return (SET_ERROR(EIO)); } } } byteswap: /* Byteswap the buf's data if necessary */ if (bswap != DMU_BSWAP_NUMFUNCS) { ASSERT(!HDR_SHARED_DATA(hdr)); ASSERT3U(bswap, <, DMU_BSWAP_NUMFUNCS); dmu_ot_byteswap[bswap].ob_func(buf->b_data, HDR_GET_LSIZE(hdr)); } /* Compute the hdr's checksum if necessary */ arc_cksum_compute(buf); return (0); } /* * If this function is being called to decrypt an encrypted buffer or verify an * authenticated one, the key must be loaded and a mapping must be made * available in the keystore via spa_keystore_create_mapping() or one of its * callers. */ int arc_untransform(arc_buf_t *buf, spa_t *spa, const zbookmark_phys_t *zb, boolean_t in_place) { int ret; arc_fill_flags_t flags = 0; if (in_place) flags |= ARC_FILL_IN_PLACE; ret = arc_buf_fill(buf, spa, zb, flags); if (ret == ECKSUM) { /* * Convert authentication and decryption errors to EIO * (and generate an ereport) before leaving the ARC. */ ret = SET_ERROR(EIO); spa_log_error(spa, zb); (void) zfs_ereport_post(FM_EREPORT_ZFS_AUTHENTICATION, spa, NULL, zb, NULL, 0); } return (ret); } /* * Increment the amount of evictable space in the arc_state_t's refcount. * We account for the space used by the hdr and the arc buf individually * so that we can add and remove them from the refcount individually. */ static void arc_evictable_space_increment(arc_buf_hdr_t *hdr, arc_state_t *state) { arc_buf_contents_t type = arc_buf_type(hdr); ASSERT(HDR_HAS_L1HDR(hdr)); if (GHOST_STATE(state)) { ASSERT0(hdr->b_l1hdr.b_bufcnt); ASSERT3P(hdr->b_l1hdr.b_buf, ==, NULL); ASSERT3P(hdr->b_l1hdr.b_pabd, ==, NULL); ASSERT(!HDR_HAS_RABD(hdr)); (void) zfs_refcount_add_many(&state->arcs_esize[type], HDR_GET_LSIZE(hdr), hdr); return; } ASSERT(!GHOST_STATE(state)); if (hdr->b_l1hdr.b_pabd != NULL) { (void) zfs_refcount_add_many(&state->arcs_esize[type], arc_hdr_size(hdr), hdr); } if (HDR_HAS_RABD(hdr)) { (void) zfs_refcount_add_many(&state->arcs_esize[type], HDR_GET_PSIZE(hdr), hdr); } for (arc_buf_t *buf = hdr->b_l1hdr.b_buf; buf != NULL; buf = buf->b_next) { if (arc_buf_is_shared(buf)) continue; (void) zfs_refcount_add_many(&state->arcs_esize[type], arc_buf_size(buf), buf); } } /* * Decrement the amount of evictable space in the arc_state_t's refcount. * We account for the space used by the hdr and the arc buf individually * so that we can add and remove them from the refcount individually. */ static void arc_evictable_space_decrement(arc_buf_hdr_t *hdr, arc_state_t *state) { arc_buf_contents_t type = arc_buf_type(hdr); ASSERT(HDR_HAS_L1HDR(hdr)); if (GHOST_STATE(state)) { ASSERT0(hdr->b_l1hdr.b_bufcnt); ASSERT3P(hdr->b_l1hdr.b_buf, ==, NULL); ASSERT3P(hdr->b_l1hdr.b_pabd, ==, NULL); ASSERT(!HDR_HAS_RABD(hdr)); (void) zfs_refcount_remove_many(&state->arcs_esize[type], HDR_GET_LSIZE(hdr), hdr); return; } ASSERT(!GHOST_STATE(state)); if (hdr->b_l1hdr.b_pabd != NULL) { (void) zfs_refcount_remove_many(&state->arcs_esize[type], arc_hdr_size(hdr), hdr); } if (HDR_HAS_RABD(hdr)) { (void) zfs_refcount_remove_many(&state->arcs_esize[type], HDR_GET_PSIZE(hdr), hdr); } for (arc_buf_t *buf = hdr->b_l1hdr.b_buf; buf != NULL; buf = buf->b_next) { if (arc_buf_is_shared(buf)) continue; (void) zfs_refcount_remove_many(&state->arcs_esize[type], arc_buf_size(buf), buf); } } /* * Add a reference to this hdr indicating that someone is actively * referencing that memory. When the refcount transitions from 0 to 1, * we remove it from the respective arc_state_t list to indicate that * it is not evictable. */ static void add_reference(arc_buf_hdr_t *hdr, void *tag) { arc_state_t *state; ASSERT(HDR_HAS_L1HDR(hdr)); if (!HDR_EMPTY(hdr) && !MUTEX_HELD(HDR_LOCK(hdr))) { ASSERT(hdr->b_l1hdr.b_state == arc_anon); ASSERT(zfs_refcount_is_zero(&hdr->b_l1hdr.b_refcnt)); ASSERT3P(hdr->b_l1hdr.b_buf, ==, NULL); } state = hdr->b_l1hdr.b_state; if ((zfs_refcount_add(&hdr->b_l1hdr.b_refcnt, tag) == 1) && (state != arc_anon)) { /* We don't use the L2-only state list. */ if (state != arc_l2c_only) { multilist_remove(state->arcs_list[arc_buf_type(hdr)], hdr); arc_evictable_space_decrement(hdr, state); } /* remove the prefetch flag if we get a reference */ if (HDR_HAS_L2HDR(hdr)) l2arc_hdr_arcstats_decrement_state(hdr); arc_hdr_clear_flags(hdr, ARC_FLAG_PREFETCH); if (HDR_HAS_L2HDR(hdr)) l2arc_hdr_arcstats_increment_state(hdr); } } /* * Remove a reference from this hdr. When the reference transitions from * 1 to 0 and we're not anonymous, then we add this hdr to the arc_state_t's * list making it eligible for eviction. */ static int remove_reference(arc_buf_hdr_t *hdr, kmutex_t *hash_lock, void *tag) { int cnt; arc_state_t *state = hdr->b_l1hdr.b_state; ASSERT(HDR_HAS_L1HDR(hdr)); ASSERT(state == arc_anon || MUTEX_HELD(hash_lock)); ASSERT(!GHOST_STATE(state)); /* * arc_l2c_only counts as a ghost state so we don't need to explicitly * check to prevent usage of the arc_l2c_only list. */ if (((cnt = zfs_refcount_remove(&hdr->b_l1hdr.b_refcnt, tag)) == 0) && (state != arc_anon)) { multilist_insert(state->arcs_list[arc_buf_type(hdr)], hdr); ASSERT3U(hdr->b_l1hdr.b_bufcnt, >, 0); arc_evictable_space_increment(hdr, state); } return (cnt); } /* * Returns detailed information about a specific arc buffer. When the * state_index argument is set the function will calculate the arc header * list position for its arc state. Since this requires a linear traversal * callers are strongly encourage not to do this. However, it can be helpful * for targeted analysis so the functionality is provided. */ void arc_buf_info(arc_buf_t *ab, arc_buf_info_t *abi, int state_index) { arc_buf_hdr_t *hdr = ab->b_hdr; l1arc_buf_hdr_t *l1hdr = NULL; l2arc_buf_hdr_t *l2hdr = NULL; arc_state_t *state = NULL; memset(abi, 0, sizeof (arc_buf_info_t)); if (hdr == NULL) return; abi->abi_flags = hdr->b_flags; if (HDR_HAS_L1HDR(hdr)) { l1hdr = &hdr->b_l1hdr; state = l1hdr->b_state; } if (HDR_HAS_L2HDR(hdr)) l2hdr = &hdr->b_l2hdr; if (l1hdr) { abi->abi_bufcnt = l1hdr->b_bufcnt; abi->abi_access = l1hdr->b_arc_access; abi->abi_mru_hits = l1hdr->b_mru_hits; abi->abi_mru_ghost_hits = l1hdr->b_mru_ghost_hits; abi->abi_mfu_hits = l1hdr->b_mfu_hits; abi->abi_mfu_ghost_hits = l1hdr->b_mfu_ghost_hits; abi->abi_holds = zfs_refcount_count(&l1hdr->b_refcnt); } if (l2hdr) { abi->abi_l2arc_dattr = l2hdr->b_daddr; abi->abi_l2arc_hits = l2hdr->b_hits; } abi->abi_state_type = state ? state->arcs_state : ARC_STATE_ANON; abi->abi_state_contents = arc_buf_type(hdr); abi->abi_size = arc_hdr_size(hdr); } /* * Move the supplied buffer to the indicated state. The hash lock * for the buffer must be held by the caller. */ static void arc_change_state(arc_state_t *new_state, arc_buf_hdr_t *hdr, kmutex_t *hash_lock) { arc_state_t *old_state; int64_t refcnt; uint32_t bufcnt; boolean_t update_old, update_new; arc_buf_contents_t buftype = arc_buf_type(hdr); /* * We almost always have an L1 hdr here, since we call arc_hdr_realloc() * in arc_read() when bringing a buffer out of the L2ARC. However, the * L1 hdr doesn't always exist when we change state to arc_anon before * destroying a header, in which case reallocating to add the L1 hdr is * pointless. */ if (HDR_HAS_L1HDR(hdr)) { old_state = hdr->b_l1hdr.b_state; refcnt = zfs_refcount_count(&hdr->b_l1hdr.b_refcnt); bufcnt = hdr->b_l1hdr.b_bufcnt; update_old = (bufcnt > 0 || hdr->b_l1hdr.b_pabd != NULL || HDR_HAS_RABD(hdr)); } else { old_state = arc_l2c_only; refcnt = 0; bufcnt = 0; update_old = B_FALSE; } update_new = update_old; ASSERT(MUTEX_HELD(hash_lock)); ASSERT3P(new_state, !=, old_state); ASSERT(!GHOST_STATE(new_state) || bufcnt == 0); ASSERT(old_state != arc_anon || bufcnt <= 1); /* * If this buffer is evictable, transfer it from the * old state list to the new state list. */ if (refcnt == 0) { if (old_state != arc_anon && old_state != arc_l2c_only) { ASSERT(HDR_HAS_L1HDR(hdr)); multilist_remove(old_state->arcs_list[buftype], hdr); if (GHOST_STATE(old_state)) { ASSERT0(bufcnt); ASSERT3P(hdr->b_l1hdr.b_buf, ==, NULL); update_old = B_TRUE; } arc_evictable_space_decrement(hdr, old_state); } if (new_state != arc_anon && new_state != arc_l2c_only) { /* * An L1 header always exists here, since if we're * moving to some L1-cached state (i.e. not l2c_only or * anonymous), we realloc the header to add an L1hdr * beforehand. */ ASSERT(HDR_HAS_L1HDR(hdr)); multilist_insert(new_state->arcs_list[buftype], hdr); if (GHOST_STATE(new_state)) { ASSERT0(bufcnt); ASSERT3P(hdr->b_l1hdr.b_buf, ==, NULL); update_new = B_TRUE; } arc_evictable_space_increment(hdr, new_state); } } ASSERT(!HDR_EMPTY(hdr)); if (new_state == arc_anon && HDR_IN_HASH_TABLE(hdr)) buf_hash_remove(hdr); /* adjust state sizes (ignore arc_l2c_only) */ if (update_new && new_state != arc_l2c_only) { ASSERT(HDR_HAS_L1HDR(hdr)); if (GHOST_STATE(new_state)) { ASSERT0(bufcnt); /* * When moving a header to a ghost state, we first * remove all arc buffers. Thus, we'll have a * bufcnt of zero, and no arc buffer to use for * the reference. As a result, we use the arc * header pointer for the reference. */ (void) zfs_refcount_add_many(&new_state->arcs_size, HDR_GET_LSIZE(hdr), hdr); ASSERT3P(hdr->b_l1hdr.b_pabd, ==, NULL); ASSERT(!HDR_HAS_RABD(hdr)); } else { uint32_t buffers = 0; /* * Each individual buffer holds a unique reference, * thus we must remove each of these references one * at a time. */ for (arc_buf_t *buf = hdr->b_l1hdr.b_buf; buf != NULL; buf = buf->b_next) { ASSERT3U(bufcnt, !=, 0); buffers++; /* * When the arc_buf_t is sharing the data * block with the hdr, the owner of the * reference belongs to the hdr. Only * add to the refcount if the arc_buf_t is * not shared. */ if (arc_buf_is_shared(buf)) continue; (void) zfs_refcount_add_many( &new_state->arcs_size, arc_buf_size(buf), buf); } ASSERT3U(bufcnt, ==, buffers); if (hdr->b_l1hdr.b_pabd != NULL) { (void) zfs_refcount_add_many( &new_state->arcs_size, arc_hdr_size(hdr), hdr); } if (HDR_HAS_RABD(hdr)) { (void) zfs_refcount_add_many( &new_state->arcs_size, HDR_GET_PSIZE(hdr), hdr); } } } if (update_old && old_state != arc_l2c_only) { ASSERT(HDR_HAS_L1HDR(hdr)); if (GHOST_STATE(old_state)) { ASSERT0(bufcnt); ASSERT3P(hdr->b_l1hdr.b_pabd, ==, NULL); ASSERT(!HDR_HAS_RABD(hdr)); /* * When moving a header off of a ghost state, * the header will not contain any arc buffers. * We use the arc header pointer for the reference * which is exactly what we did when we put the * header on the ghost state. */ (void) zfs_refcount_remove_many(&old_state->arcs_size, HDR_GET_LSIZE(hdr), hdr); } else { uint32_t buffers = 0; /* * Each individual buffer holds a unique reference, * thus we must remove each of these references one * at a time. */ for (arc_buf_t *buf = hdr->b_l1hdr.b_buf; buf != NULL; buf = buf->b_next) { ASSERT3U(bufcnt, !=, 0); buffers++; /* * When the arc_buf_t is sharing the data * block with the hdr, the owner of the * reference belongs to the hdr. Only * add to the refcount if the arc_buf_t is * not shared. */ if (arc_buf_is_shared(buf)) continue; (void) zfs_refcount_remove_many( &old_state->arcs_size, arc_buf_size(buf), buf); } ASSERT3U(bufcnt, ==, buffers); ASSERT(hdr->b_l1hdr.b_pabd != NULL || HDR_HAS_RABD(hdr)); if (hdr->b_l1hdr.b_pabd != NULL) { (void) zfs_refcount_remove_many( &old_state->arcs_size, arc_hdr_size(hdr), hdr); } if (HDR_HAS_RABD(hdr)) { (void) zfs_refcount_remove_many( &old_state->arcs_size, HDR_GET_PSIZE(hdr), hdr); } } } if (HDR_HAS_L1HDR(hdr)) { hdr->b_l1hdr.b_state = new_state; if (HDR_HAS_L2HDR(hdr) && new_state != arc_l2c_only) { l2arc_hdr_arcstats_decrement_state(hdr); hdr->b_l2hdr.b_arcs_state = new_state->arcs_state; l2arc_hdr_arcstats_increment_state(hdr); } } /* * L2 headers should never be on the L2 state list since they don't * have L1 headers allocated. */ ASSERT(multilist_is_empty(arc_l2c_only->arcs_list[ARC_BUFC_DATA]) && multilist_is_empty(arc_l2c_only->arcs_list[ARC_BUFC_METADATA])); } void arc_space_consume(uint64_t space, arc_space_type_t type) { ASSERT(type >= 0 && type < ARC_SPACE_NUMTYPES); switch (type) { default: break; case ARC_SPACE_DATA: aggsum_add(&astat_data_size, space); break; case ARC_SPACE_META: aggsum_add(&astat_metadata_size, space); break; case ARC_SPACE_BONUS: aggsum_add(&astat_bonus_size, space); break; case ARC_SPACE_DNODE: aggsum_add(&astat_dnode_size, space); break; case ARC_SPACE_DBUF: aggsum_add(&astat_dbuf_size, space); break; case ARC_SPACE_HDRS: aggsum_add(&astat_hdr_size, space); break; case ARC_SPACE_L2HDRS: aggsum_add(&astat_l2_hdr_size, space); break; case ARC_SPACE_ABD_CHUNK_WASTE: /* * Note: this includes space wasted by all scatter ABD's, not * just those allocated by the ARC. But the vast majority of * scatter ABD's come from the ARC, because other users are * very short-lived. */ aggsum_add(&astat_abd_chunk_waste_size, space); break; } if (type != ARC_SPACE_DATA && type != ARC_SPACE_ABD_CHUNK_WASTE) aggsum_add(&arc_meta_used, space); aggsum_add(&arc_size, space); } void arc_space_return(uint64_t space, arc_space_type_t type) { ASSERT(type >= 0 && type < ARC_SPACE_NUMTYPES); switch (type) { default: break; case ARC_SPACE_DATA: aggsum_add(&astat_data_size, -space); break; case ARC_SPACE_META: aggsum_add(&astat_metadata_size, -space); break; case ARC_SPACE_BONUS: aggsum_add(&astat_bonus_size, -space); break; case ARC_SPACE_DNODE: aggsum_add(&astat_dnode_size, -space); break; case ARC_SPACE_DBUF: aggsum_add(&astat_dbuf_size, -space); break; case ARC_SPACE_HDRS: aggsum_add(&astat_hdr_size, -space); break; case ARC_SPACE_L2HDRS: aggsum_add(&astat_l2_hdr_size, -space); break; case ARC_SPACE_ABD_CHUNK_WASTE: aggsum_add(&astat_abd_chunk_waste_size, -space); break; } if (type != ARC_SPACE_DATA && type != ARC_SPACE_ABD_CHUNK_WASTE) { ASSERT(aggsum_compare(&arc_meta_used, space) >= 0); /* * We use the upper bound here rather than the precise value * because the arc_meta_max value doesn't need to be * precise. It's only consumed by humans via arcstats. */ if (arc_meta_max < aggsum_upper_bound(&arc_meta_used)) arc_meta_max = aggsum_upper_bound(&arc_meta_used); aggsum_add(&arc_meta_used, -space); } ASSERT(aggsum_compare(&arc_size, space) >= 0); aggsum_add(&arc_size, -space); } /* * Given a hdr and a buf, returns whether that buf can share its b_data buffer * with the hdr's b_pabd. */ static boolean_t arc_can_share(arc_buf_hdr_t *hdr, arc_buf_t *buf) { /* * The criteria for sharing a hdr's data are: * 1. the buffer is not encrypted * 2. the hdr's compression matches the buf's compression * 3. the hdr doesn't need to be byteswapped * 4. the hdr isn't already being shared * 5. the buf is either compressed or it is the last buf in the hdr list * * Criterion #5 maintains the invariant that shared uncompressed * bufs must be the final buf in the hdr's b_buf list. Reading this, you * might ask, "if a compressed buf is allocated first, won't that be the * last thing in the list?", but in that case it's impossible to create * a shared uncompressed buf anyway (because the hdr must be compressed * to have the compressed buf). You might also think that #3 is * sufficient to make this guarantee, however it's possible * (specifically in the rare L2ARC write race mentioned in * arc_buf_alloc_impl()) there will be an existing uncompressed buf that * is shareable, but wasn't at the time of its allocation. Rather than * allow a new shared uncompressed buf to be created and then shuffle * the list around to make it the last element, this simply disallows * sharing if the new buf isn't the first to be added. */ ASSERT3P(buf->b_hdr, ==, hdr); boolean_t hdr_compressed = arc_hdr_get_compress(hdr) != ZIO_COMPRESS_OFF; boolean_t buf_compressed = ARC_BUF_COMPRESSED(buf) != 0; return (!ARC_BUF_ENCRYPTED(buf) && buf_compressed == hdr_compressed && hdr->b_l1hdr.b_byteswap == DMU_BSWAP_NUMFUNCS && !HDR_SHARED_DATA(hdr) && (ARC_BUF_LAST(buf) || ARC_BUF_COMPRESSED(buf))); } /* * Allocate a buf for this hdr. If you care about the data that's in the hdr, * or if you want a compressed buffer, pass those flags in. Returns 0 if the * copy was made successfully, or an error code otherwise. */ static int arc_buf_alloc_impl(arc_buf_hdr_t *hdr, spa_t *spa, const zbookmark_phys_t *zb, void *tag, boolean_t encrypted, boolean_t compressed, boolean_t noauth, boolean_t fill, arc_buf_t **ret) { arc_buf_t *buf; arc_fill_flags_t flags = ARC_FILL_LOCKED; ASSERT(HDR_HAS_L1HDR(hdr)); ASSERT3U(HDR_GET_LSIZE(hdr), >, 0); VERIFY(hdr->b_type == ARC_BUFC_DATA || hdr->b_type == ARC_BUFC_METADATA); ASSERT3P(ret, !=, NULL); ASSERT3P(*ret, ==, NULL); IMPLY(encrypted, compressed); hdr->b_l1hdr.b_mru_hits = 0; hdr->b_l1hdr.b_mru_ghost_hits = 0; hdr->b_l1hdr.b_mfu_hits = 0; hdr->b_l1hdr.b_mfu_ghost_hits = 0; hdr->b_l1hdr.b_l2_hits = 0; buf = *ret = kmem_cache_alloc(buf_cache, KM_PUSHPAGE); buf->b_hdr = hdr; buf->b_data = NULL; buf->b_next = hdr->b_l1hdr.b_buf; buf->b_flags = 0; add_reference(hdr, tag); /* * We're about to change the hdr's b_flags. We must either * hold the hash_lock or be undiscoverable. */ ASSERT(HDR_EMPTY_OR_LOCKED(hdr)); /* * Only honor requests for compressed bufs if the hdr is actually * compressed. This must be overridden if the buffer is encrypted since * encrypted buffers cannot be decompressed. */ if (encrypted) { buf->b_flags |= ARC_BUF_FLAG_COMPRESSED; buf->b_flags |= ARC_BUF_FLAG_ENCRYPTED; flags |= ARC_FILL_COMPRESSED | ARC_FILL_ENCRYPTED; } else if (compressed && arc_hdr_get_compress(hdr) != ZIO_COMPRESS_OFF) { buf->b_flags |= ARC_BUF_FLAG_COMPRESSED; flags |= ARC_FILL_COMPRESSED; } if (noauth) { ASSERT0(encrypted); flags |= ARC_FILL_NOAUTH; } /* * If the hdr's data can be shared then we share the data buffer and * set the appropriate bit in the hdr's b_flags to indicate the hdr is * sharing it's b_pabd with the arc_buf_t. Otherwise, we allocate a new * buffer to store the buf's data. * * There are two additional restrictions here because we're sharing * hdr -> buf instead of the usual buf -> hdr. First, the hdr can't be * actively involved in an L2ARC write, because if this buf is used by * an arc_write() then the hdr's data buffer will be released when the * write completes, even though the L2ARC write might still be using it. * Second, the hdr's ABD must be linear so that the buf's user doesn't * need to be ABD-aware. It must be allocated via * zio_[data_]buf_alloc(), not as a page, because we need to be able * to abd_release_ownership_of_buf(), which isn't allowed on "linear * page" buffers because the ABD code needs to handle freeing them * specially. */ boolean_t can_share = arc_can_share(hdr, buf) && !HDR_L2_WRITING(hdr) && hdr->b_l1hdr.b_pabd != NULL && abd_is_linear(hdr->b_l1hdr.b_pabd) && !abd_is_linear_page(hdr->b_l1hdr.b_pabd); /* Set up b_data and sharing */ if (can_share) { buf->b_data = abd_to_buf(hdr->b_l1hdr.b_pabd); buf->b_flags |= ARC_BUF_FLAG_SHARED; arc_hdr_set_flags(hdr, ARC_FLAG_SHARED_DATA); } else { buf->b_data = arc_get_data_buf(hdr, arc_buf_size(buf), buf); ARCSTAT_INCR(arcstat_overhead_size, arc_buf_size(buf)); } VERIFY3P(buf->b_data, !=, NULL); hdr->b_l1hdr.b_buf = buf; hdr->b_l1hdr.b_bufcnt += 1; if (encrypted) hdr->b_crypt_hdr.b_ebufcnt += 1; /* * If the user wants the data from the hdr, we need to either copy or * decompress the data. */ if (fill) { ASSERT3P(zb, !=, NULL); return (arc_buf_fill(buf, spa, zb, flags)); } return (0); } static char *arc_onloan_tag = "onloan"; static inline void arc_loaned_bytes_update(int64_t delta) { atomic_add_64(&arc_loaned_bytes, delta); /* assert that it did not wrap around */ ASSERT3S(atomic_add_64_nv(&arc_loaned_bytes, 0), >=, 0); } /* * Loan out an anonymous arc buffer. Loaned buffers are not counted as in * flight data by arc_tempreserve_space() until they are "returned". Loaned * buffers must be returned to the arc before they can be used by the DMU or * freed. */ arc_buf_t * arc_loan_buf(spa_t *spa, boolean_t is_metadata, int size) { arc_buf_t *buf = arc_alloc_buf(spa, arc_onloan_tag, is_metadata ? ARC_BUFC_METADATA : ARC_BUFC_DATA, size); arc_loaned_bytes_update(arc_buf_size(buf)); return (buf); } arc_buf_t * arc_loan_compressed_buf(spa_t *spa, uint64_t psize, uint64_t lsize, enum zio_compress compression_type, uint8_t complevel) { arc_buf_t *buf = arc_alloc_compressed_buf(spa, arc_onloan_tag, psize, lsize, compression_type, complevel); arc_loaned_bytes_update(arc_buf_size(buf)); return (buf); } arc_buf_t * arc_loan_raw_buf(spa_t *spa, uint64_t dsobj, boolean_t byteorder, const uint8_t *salt, const uint8_t *iv, const uint8_t *mac, dmu_object_type_t ot, uint64_t psize, uint64_t lsize, enum zio_compress compression_type, uint8_t complevel) { arc_buf_t *buf = arc_alloc_raw_buf(spa, arc_onloan_tag, dsobj, byteorder, salt, iv, mac, ot, psize, lsize, compression_type, complevel); atomic_add_64(&arc_loaned_bytes, psize); return (buf); } /* * Return a loaned arc buffer to the arc. */ void arc_return_buf(arc_buf_t *buf, void *tag) { arc_buf_hdr_t *hdr = buf->b_hdr; ASSERT3P(buf->b_data, !=, NULL); ASSERT(HDR_HAS_L1HDR(hdr)); (void) zfs_refcount_add(&hdr->b_l1hdr.b_refcnt, tag); (void) zfs_refcount_remove(&hdr->b_l1hdr.b_refcnt, arc_onloan_tag); arc_loaned_bytes_update(-arc_buf_size(buf)); } /* Detach an arc_buf from a dbuf (tag) */ void arc_loan_inuse_buf(arc_buf_t *buf, void *tag) { arc_buf_hdr_t *hdr = buf->b_hdr; ASSERT3P(buf->b_data, !=, NULL); ASSERT(HDR_HAS_L1HDR(hdr)); (void) zfs_refcount_add(&hdr->b_l1hdr.b_refcnt, arc_onloan_tag); (void) zfs_refcount_remove(&hdr->b_l1hdr.b_refcnt, tag); arc_loaned_bytes_update(arc_buf_size(buf)); } static void l2arc_free_abd_on_write(abd_t *abd, size_t size, arc_buf_contents_t type) { l2arc_data_free_t *df = kmem_alloc(sizeof (*df), KM_SLEEP); df->l2df_abd = abd; df->l2df_size = size; df->l2df_type = type; mutex_enter(&l2arc_free_on_write_mtx); list_insert_head(l2arc_free_on_write, df); mutex_exit(&l2arc_free_on_write_mtx); } static void arc_hdr_free_on_write(arc_buf_hdr_t *hdr, boolean_t free_rdata) { arc_state_t *state = hdr->b_l1hdr.b_state; arc_buf_contents_t type = arc_buf_type(hdr); uint64_t size = (free_rdata) ? HDR_GET_PSIZE(hdr) : arc_hdr_size(hdr); /* protected by hash lock, if in the hash table */ if (multilist_link_active(&hdr->b_l1hdr.b_arc_node)) { ASSERT(zfs_refcount_is_zero(&hdr->b_l1hdr.b_refcnt)); ASSERT(state != arc_anon && state != arc_l2c_only); (void) zfs_refcount_remove_many(&state->arcs_esize[type], size, hdr); } (void) zfs_refcount_remove_many(&state->arcs_size, size, hdr); if (type == ARC_BUFC_METADATA) { arc_space_return(size, ARC_SPACE_META); } else { ASSERT(type == ARC_BUFC_DATA); arc_space_return(size, ARC_SPACE_DATA); } if (free_rdata) { l2arc_free_abd_on_write(hdr->b_crypt_hdr.b_rabd, size, type); } else { l2arc_free_abd_on_write(hdr->b_l1hdr.b_pabd, size, type); } } /* * Share the arc_buf_t's data with the hdr. Whenever we are sharing the * data buffer, we transfer the refcount ownership to the hdr and update * the appropriate kstats. */ static void arc_share_buf(arc_buf_hdr_t *hdr, arc_buf_t *buf) { ASSERT(arc_can_share(hdr, buf)); ASSERT3P(hdr->b_l1hdr.b_pabd, ==, NULL); ASSERT(!ARC_BUF_ENCRYPTED(buf)); ASSERT(HDR_EMPTY_OR_LOCKED(hdr)); /* * Start sharing the data buffer. We transfer the * refcount ownership to the hdr since it always owns * the refcount whenever an arc_buf_t is shared. */ zfs_refcount_transfer_ownership_many(&hdr->b_l1hdr.b_state->arcs_size, arc_hdr_size(hdr), buf, hdr); hdr->b_l1hdr.b_pabd = abd_get_from_buf(buf->b_data, arc_buf_size(buf)); abd_take_ownership_of_buf(hdr->b_l1hdr.b_pabd, HDR_ISTYPE_METADATA(hdr)); arc_hdr_set_flags(hdr, ARC_FLAG_SHARED_DATA); buf->b_flags |= ARC_BUF_FLAG_SHARED; /* * Since we've transferred ownership to the hdr we need * to increment its compressed and uncompressed kstats and * decrement the overhead size. */ ARCSTAT_INCR(arcstat_compressed_size, arc_hdr_size(hdr)); ARCSTAT_INCR(arcstat_uncompressed_size, HDR_GET_LSIZE(hdr)); ARCSTAT_INCR(arcstat_overhead_size, -arc_buf_size(buf)); } static void arc_unshare_buf(arc_buf_hdr_t *hdr, arc_buf_t *buf) { ASSERT(arc_buf_is_shared(buf)); ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL); ASSERT(HDR_EMPTY_OR_LOCKED(hdr)); /* * We are no longer sharing this buffer so we need * to transfer its ownership to the rightful owner. */ zfs_refcount_transfer_ownership_many(&hdr->b_l1hdr.b_state->arcs_size, arc_hdr_size(hdr), hdr, buf); arc_hdr_clear_flags(hdr, ARC_FLAG_SHARED_DATA); abd_release_ownership_of_buf(hdr->b_l1hdr.b_pabd); - abd_put(hdr->b_l1hdr.b_pabd); + abd_free(hdr->b_l1hdr.b_pabd); hdr->b_l1hdr.b_pabd = NULL; buf->b_flags &= ~ARC_BUF_FLAG_SHARED; /* * Since the buffer is no longer shared between * the arc buf and the hdr, count it as overhead. */ ARCSTAT_INCR(arcstat_compressed_size, -arc_hdr_size(hdr)); ARCSTAT_INCR(arcstat_uncompressed_size, -HDR_GET_LSIZE(hdr)); ARCSTAT_INCR(arcstat_overhead_size, arc_buf_size(buf)); } /* * Remove an arc_buf_t from the hdr's buf list and return the last * arc_buf_t on the list. If no buffers remain on the list then return * NULL. */ static arc_buf_t * arc_buf_remove(arc_buf_hdr_t *hdr, arc_buf_t *buf) { ASSERT(HDR_HAS_L1HDR(hdr)); ASSERT(HDR_EMPTY_OR_LOCKED(hdr)); arc_buf_t **bufp = &hdr->b_l1hdr.b_buf; arc_buf_t *lastbuf = NULL; /* * Remove the buf from the hdr list and locate the last * remaining buffer on the list. */ while (*bufp != NULL) { if (*bufp == buf) *bufp = buf->b_next; /* * If we've removed a buffer in the middle of * the list then update the lastbuf and update * bufp. */ if (*bufp != NULL) { lastbuf = *bufp; bufp = &(*bufp)->b_next; } } buf->b_next = NULL; ASSERT3P(lastbuf, !=, buf); IMPLY(hdr->b_l1hdr.b_bufcnt > 0, lastbuf != NULL); IMPLY(hdr->b_l1hdr.b_bufcnt > 0, hdr->b_l1hdr.b_buf != NULL); IMPLY(lastbuf != NULL, ARC_BUF_LAST(lastbuf)); return (lastbuf); } /* * Free up buf->b_data and pull the arc_buf_t off of the arc_buf_hdr_t's * list and free it. */ static void arc_buf_destroy_impl(arc_buf_t *buf) { arc_buf_hdr_t *hdr = buf->b_hdr; /* * Free up the data associated with the buf but only if we're not * sharing this with the hdr. If we are sharing it with the hdr, the * hdr is responsible for doing the free. */ if (buf->b_data != NULL) { /* * We're about to change the hdr's b_flags. We must either * hold the hash_lock or be undiscoverable. */ ASSERT(HDR_EMPTY_OR_LOCKED(hdr)); arc_cksum_verify(buf); arc_buf_unwatch(buf); if (arc_buf_is_shared(buf)) { arc_hdr_clear_flags(hdr, ARC_FLAG_SHARED_DATA); } else { uint64_t size = arc_buf_size(buf); arc_free_data_buf(hdr, buf->b_data, size, buf); ARCSTAT_INCR(arcstat_overhead_size, -size); } buf->b_data = NULL; ASSERT(hdr->b_l1hdr.b_bufcnt > 0); hdr->b_l1hdr.b_bufcnt -= 1; if (ARC_BUF_ENCRYPTED(buf)) { hdr->b_crypt_hdr.b_ebufcnt -= 1; /* * If we have no more encrypted buffers and we've * already gotten a copy of the decrypted data we can * free b_rabd to save some space. */ if (hdr->b_crypt_hdr.b_ebufcnt == 0 && HDR_HAS_RABD(hdr) && hdr->b_l1hdr.b_pabd != NULL && !HDR_IO_IN_PROGRESS(hdr)) { arc_hdr_free_abd(hdr, B_TRUE); } } } arc_buf_t *lastbuf = arc_buf_remove(hdr, buf); if (ARC_BUF_SHARED(buf) && !ARC_BUF_COMPRESSED(buf)) { /* * If the current arc_buf_t is sharing its data buffer with the * hdr, then reassign the hdr's b_pabd to share it with the new * buffer at the end of the list. The shared buffer is always * the last one on the hdr's buffer list. * * There is an equivalent case for compressed bufs, but since * they aren't guaranteed to be the last buf in the list and * that is an exceedingly rare case, we just allow that space be * wasted temporarily. We must also be careful not to share * encrypted buffers, since they cannot be shared. */ if (lastbuf != NULL && !ARC_BUF_ENCRYPTED(lastbuf)) { /* Only one buf can be shared at once */ VERIFY(!arc_buf_is_shared(lastbuf)); /* hdr is uncompressed so can't have compressed buf */ VERIFY(!ARC_BUF_COMPRESSED(lastbuf)); ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL); arc_hdr_free_abd(hdr, B_FALSE); /* * We must setup a new shared block between the * last buffer and the hdr. The data would have * been allocated by the arc buf so we need to transfer * ownership to the hdr since it's now being shared. */ arc_share_buf(hdr, lastbuf); } } else if (HDR_SHARED_DATA(hdr)) { /* * Uncompressed shared buffers are always at the end * of the list. Compressed buffers don't have the * same requirements. This makes it hard to * simply assert that the lastbuf is shared so * we rely on the hdr's compression flags to determine * if we have a compressed, shared buffer. */ ASSERT3P(lastbuf, !=, NULL); ASSERT(arc_buf_is_shared(lastbuf) || arc_hdr_get_compress(hdr) != ZIO_COMPRESS_OFF); } /* * Free the checksum if we're removing the last uncompressed buf from * this hdr. */ if (!arc_hdr_has_uncompressed_buf(hdr)) { arc_cksum_free(hdr); } /* clean up the buf */ buf->b_hdr = NULL; kmem_cache_free(buf_cache, buf); } static void arc_hdr_alloc_abd(arc_buf_hdr_t *hdr, int alloc_flags) { uint64_t size; boolean_t alloc_rdata = ((alloc_flags & ARC_HDR_ALLOC_RDATA) != 0); boolean_t do_adapt = ((alloc_flags & ARC_HDR_DO_ADAPT) != 0); ASSERT3U(HDR_GET_LSIZE(hdr), >, 0); ASSERT(HDR_HAS_L1HDR(hdr)); ASSERT(!HDR_SHARED_DATA(hdr) || alloc_rdata); IMPLY(alloc_rdata, HDR_PROTECTED(hdr)); if (alloc_rdata) { size = HDR_GET_PSIZE(hdr); ASSERT3P(hdr->b_crypt_hdr.b_rabd, ==, NULL); hdr->b_crypt_hdr.b_rabd = arc_get_data_abd(hdr, size, hdr, do_adapt); ASSERT3P(hdr->b_crypt_hdr.b_rabd, !=, NULL); ARCSTAT_INCR(arcstat_raw_size, size); } else { size = arc_hdr_size(hdr); ASSERT3P(hdr->b_l1hdr.b_pabd, ==, NULL); hdr->b_l1hdr.b_pabd = arc_get_data_abd(hdr, size, hdr, do_adapt); ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL); } ARCSTAT_INCR(arcstat_compressed_size, size); ARCSTAT_INCR(arcstat_uncompressed_size, HDR_GET_LSIZE(hdr)); } static void arc_hdr_free_abd(arc_buf_hdr_t *hdr, boolean_t free_rdata) { uint64_t size = (free_rdata) ? HDR_GET_PSIZE(hdr) : arc_hdr_size(hdr); ASSERT(HDR_HAS_L1HDR(hdr)); ASSERT(hdr->b_l1hdr.b_pabd != NULL || HDR_HAS_RABD(hdr)); IMPLY(free_rdata, HDR_HAS_RABD(hdr)); /* * If the hdr is currently being written to the l2arc then * we defer freeing the data by adding it to the l2arc_free_on_write * list. The l2arc will free the data once it's finished * writing it to the l2arc device. */ if (HDR_L2_WRITING(hdr)) { arc_hdr_free_on_write(hdr, free_rdata); ARCSTAT_BUMP(arcstat_l2_free_on_write); } else if (free_rdata) { arc_free_data_abd(hdr, hdr->b_crypt_hdr.b_rabd, size, hdr); } else { arc_free_data_abd(hdr, hdr->b_l1hdr.b_pabd, size, hdr); } if (free_rdata) { hdr->b_crypt_hdr.b_rabd = NULL; ARCSTAT_INCR(arcstat_raw_size, -size); } else { hdr->b_l1hdr.b_pabd = NULL; } if (hdr->b_l1hdr.b_pabd == NULL && !HDR_HAS_RABD(hdr)) hdr->b_l1hdr.b_byteswap = DMU_BSWAP_NUMFUNCS; ARCSTAT_INCR(arcstat_compressed_size, -size); ARCSTAT_INCR(arcstat_uncompressed_size, -HDR_GET_LSIZE(hdr)); } static arc_buf_hdr_t * arc_hdr_alloc(uint64_t spa, int32_t psize, int32_t lsize, boolean_t protected, enum zio_compress compression_type, uint8_t complevel, arc_buf_contents_t type, boolean_t alloc_rdata) { arc_buf_hdr_t *hdr; int flags = ARC_HDR_DO_ADAPT; VERIFY(type == ARC_BUFC_DATA || type == ARC_BUFC_METADATA); if (protected) { hdr = kmem_cache_alloc(hdr_full_crypt_cache, KM_PUSHPAGE); } else { hdr = kmem_cache_alloc(hdr_full_cache, KM_PUSHPAGE); } flags |= alloc_rdata ? ARC_HDR_ALLOC_RDATA : 0; ASSERT(HDR_EMPTY(hdr)); ASSERT3P(hdr->b_l1hdr.b_freeze_cksum, ==, NULL); HDR_SET_PSIZE(hdr, psize); HDR_SET_LSIZE(hdr, lsize); hdr->b_spa = spa; hdr->b_type = type; hdr->b_flags = 0; arc_hdr_set_flags(hdr, arc_bufc_to_flags(type) | ARC_FLAG_HAS_L1HDR); arc_hdr_set_compress(hdr, compression_type); hdr->b_complevel = complevel; if (protected) arc_hdr_set_flags(hdr, ARC_FLAG_PROTECTED); hdr->b_l1hdr.b_state = arc_anon; hdr->b_l1hdr.b_arc_access = 0; hdr->b_l1hdr.b_bufcnt = 0; hdr->b_l1hdr.b_buf = NULL; /* * Allocate the hdr's buffer. This will contain either * the compressed or uncompressed data depending on the block * it references and compressed arc enablement. */ arc_hdr_alloc_abd(hdr, flags); ASSERT(zfs_refcount_is_zero(&hdr->b_l1hdr.b_refcnt)); return (hdr); } /* * Transition between the two allocation states for the arc_buf_hdr struct. * The arc_buf_hdr struct can be allocated with (hdr_full_cache) or without * (hdr_l2only_cache) the fields necessary for the L1 cache - the smaller * version is used when a cache buffer is only in the L2ARC in order to reduce * memory usage. */ static arc_buf_hdr_t * arc_hdr_realloc(arc_buf_hdr_t *hdr, kmem_cache_t *old, kmem_cache_t *new) { ASSERT(HDR_HAS_L2HDR(hdr)); arc_buf_hdr_t *nhdr; l2arc_dev_t *dev = hdr->b_l2hdr.b_dev; ASSERT((old == hdr_full_cache && new == hdr_l2only_cache) || (old == hdr_l2only_cache && new == hdr_full_cache)); /* * if the caller wanted a new full header and the header is to be * encrypted we will actually allocate the header from the full crypt * cache instead. The same applies to freeing from the old cache. */ if (HDR_PROTECTED(hdr) && new == hdr_full_cache) new = hdr_full_crypt_cache; if (HDR_PROTECTED(hdr) && old == hdr_full_cache) old = hdr_full_crypt_cache; nhdr = kmem_cache_alloc(new, KM_PUSHPAGE); ASSERT(MUTEX_HELD(HDR_LOCK(hdr))); buf_hash_remove(hdr); bcopy(hdr, nhdr, HDR_L2ONLY_SIZE); if (new == hdr_full_cache || new == hdr_full_crypt_cache) { arc_hdr_set_flags(nhdr, ARC_FLAG_HAS_L1HDR); /* * arc_access and arc_change_state need to be aware that a * header has just come out of L2ARC, so we set its state to * l2c_only even though it's about to change. */ nhdr->b_l1hdr.b_state = arc_l2c_only; /* Verify previous threads set to NULL before freeing */ ASSERT3P(nhdr->b_l1hdr.b_pabd, ==, NULL); ASSERT(!HDR_HAS_RABD(hdr)); } else { ASSERT3P(hdr->b_l1hdr.b_buf, ==, NULL); ASSERT0(hdr->b_l1hdr.b_bufcnt); ASSERT3P(hdr->b_l1hdr.b_freeze_cksum, ==, NULL); /* * If we've reached here, We must have been called from * arc_evict_hdr(), as such we should have already been * removed from any ghost list we were previously on * (which protects us from racing with arc_evict_state), * thus no locking is needed during this check. */ ASSERT(!multilist_link_active(&hdr->b_l1hdr.b_arc_node)); /* * A buffer must not be moved into the arc_l2c_only * state if it's not finished being written out to the * l2arc device. Otherwise, the b_l1hdr.b_pabd field * might try to be accessed, even though it was removed. */ VERIFY(!HDR_L2_WRITING(hdr)); VERIFY3P(hdr->b_l1hdr.b_pabd, ==, NULL); ASSERT(!HDR_HAS_RABD(hdr)); arc_hdr_clear_flags(nhdr, ARC_FLAG_HAS_L1HDR); } /* * The header has been reallocated so we need to re-insert it into any * lists it was on. */ (void) buf_hash_insert(nhdr, NULL); ASSERT(list_link_active(&hdr->b_l2hdr.b_l2node)); mutex_enter(&dev->l2ad_mtx); /* * We must place the realloc'ed header back into the list at * the same spot. Otherwise, if it's placed earlier in the list, * l2arc_write_buffers() could find it during the function's * write phase, and try to write it out to the l2arc. */ list_insert_after(&dev->l2ad_buflist, hdr, nhdr); list_remove(&dev->l2ad_buflist, hdr); mutex_exit(&dev->l2ad_mtx); /* * Since we're using the pointer address as the tag when * incrementing and decrementing the l2ad_alloc refcount, we * must remove the old pointer (that we're about to destroy) and * add the new pointer to the refcount. Otherwise we'd remove * the wrong pointer address when calling arc_hdr_destroy() later. */ (void) zfs_refcount_remove_many(&dev->l2ad_alloc, arc_hdr_size(hdr), hdr); (void) zfs_refcount_add_many(&dev->l2ad_alloc, arc_hdr_size(nhdr), nhdr); buf_discard_identity(hdr); kmem_cache_free(old, hdr); return (nhdr); } /* * This function allows an L1 header to be reallocated as a crypt * header and vice versa. If we are going to a crypt header, the * new fields will be zeroed out. */ static arc_buf_hdr_t * arc_hdr_realloc_crypt(arc_buf_hdr_t *hdr, boolean_t need_crypt) { arc_buf_hdr_t *nhdr; arc_buf_t *buf; kmem_cache_t *ncache, *ocache; unsigned nsize, osize; /* * This function requires that hdr is in the arc_anon state. * Therefore it won't have any L2ARC data for us to worry * about copying. */ ASSERT(HDR_HAS_L1HDR(hdr)); ASSERT(!HDR_HAS_L2HDR(hdr)); ASSERT3U(!!HDR_PROTECTED(hdr), !=, need_crypt); ASSERT3P(hdr->b_l1hdr.b_state, ==, arc_anon); ASSERT(!multilist_link_active(&hdr->b_l1hdr.b_arc_node)); ASSERT(!list_link_active(&hdr->b_l2hdr.b_l2node)); ASSERT3P(hdr->b_hash_next, ==, NULL); if (need_crypt) { ncache = hdr_full_crypt_cache; nsize = sizeof (hdr->b_crypt_hdr); ocache = hdr_full_cache; osize = HDR_FULL_SIZE; } else { ncache = hdr_full_cache; nsize = HDR_FULL_SIZE; ocache = hdr_full_crypt_cache; osize = sizeof (hdr->b_crypt_hdr); } nhdr = kmem_cache_alloc(ncache, KM_PUSHPAGE); /* * Copy all members that aren't locks or condvars to the new header. * No lists are pointing to us (as we asserted above), so we don't * need to worry about the list nodes. */ nhdr->b_dva = hdr->b_dva; nhdr->b_birth = hdr->b_birth; nhdr->b_type = hdr->b_type; nhdr->b_flags = hdr->b_flags; nhdr->b_psize = hdr->b_psize; nhdr->b_lsize = hdr->b_lsize; nhdr->b_spa = hdr->b_spa; nhdr->b_l1hdr.b_freeze_cksum = hdr->b_l1hdr.b_freeze_cksum; nhdr->b_l1hdr.b_bufcnt = hdr->b_l1hdr.b_bufcnt; nhdr->b_l1hdr.b_byteswap = hdr->b_l1hdr.b_byteswap; nhdr->b_l1hdr.b_state = hdr->b_l1hdr.b_state; nhdr->b_l1hdr.b_arc_access = hdr->b_l1hdr.b_arc_access; nhdr->b_l1hdr.b_mru_hits = hdr->b_l1hdr.b_mru_hits; nhdr->b_l1hdr.b_mru_ghost_hits = hdr->b_l1hdr.b_mru_ghost_hits; nhdr->b_l1hdr.b_mfu_hits = hdr->b_l1hdr.b_mfu_hits; nhdr->b_l1hdr.b_mfu_ghost_hits = hdr->b_l1hdr.b_mfu_ghost_hits; nhdr->b_l1hdr.b_l2_hits = hdr->b_l1hdr.b_l2_hits; nhdr->b_l1hdr.b_acb = hdr->b_l1hdr.b_acb; nhdr->b_l1hdr.b_pabd = hdr->b_l1hdr.b_pabd; /* * This zfs_refcount_add() exists only to ensure that the individual * arc buffers always point to a header that is referenced, avoiding * a small race condition that could trigger ASSERTs. */ (void) zfs_refcount_add(&nhdr->b_l1hdr.b_refcnt, FTAG); nhdr->b_l1hdr.b_buf = hdr->b_l1hdr.b_buf; for (buf = nhdr->b_l1hdr.b_buf; buf != NULL; buf = buf->b_next) { mutex_enter(&buf->b_evict_lock); buf->b_hdr = nhdr; mutex_exit(&buf->b_evict_lock); } zfs_refcount_transfer(&nhdr->b_l1hdr.b_refcnt, &hdr->b_l1hdr.b_refcnt); (void) zfs_refcount_remove(&nhdr->b_l1hdr.b_refcnt, FTAG); ASSERT0(zfs_refcount_count(&hdr->b_l1hdr.b_refcnt)); if (need_crypt) { arc_hdr_set_flags(nhdr, ARC_FLAG_PROTECTED); } else { arc_hdr_clear_flags(nhdr, ARC_FLAG_PROTECTED); } /* unset all members of the original hdr */ bzero(&hdr->b_dva, sizeof (dva_t)); hdr->b_birth = 0; hdr->b_type = ARC_BUFC_INVALID; hdr->b_flags = 0; hdr->b_psize = 0; hdr->b_lsize = 0; hdr->b_spa = 0; hdr->b_l1hdr.b_freeze_cksum = NULL; hdr->b_l1hdr.b_buf = NULL; hdr->b_l1hdr.b_bufcnt = 0; hdr->b_l1hdr.b_byteswap = 0; hdr->b_l1hdr.b_state = NULL; hdr->b_l1hdr.b_arc_access = 0; hdr->b_l1hdr.b_mru_hits = 0; hdr->b_l1hdr.b_mru_ghost_hits = 0; hdr->b_l1hdr.b_mfu_hits = 0; hdr->b_l1hdr.b_mfu_ghost_hits = 0; hdr->b_l1hdr.b_l2_hits = 0; hdr->b_l1hdr.b_acb = NULL; hdr->b_l1hdr.b_pabd = NULL; if (ocache == hdr_full_crypt_cache) { ASSERT(!HDR_HAS_RABD(hdr)); hdr->b_crypt_hdr.b_ot = DMU_OT_NONE; hdr->b_crypt_hdr.b_ebufcnt = 0; hdr->b_crypt_hdr.b_dsobj = 0; bzero(hdr->b_crypt_hdr.b_salt, ZIO_DATA_SALT_LEN); bzero(hdr->b_crypt_hdr.b_iv, ZIO_DATA_IV_LEN); bzero(hdr->b_crypt_hdr.b_mac, ZIO_DATA_MAC_LEN); } buf_discard_identity(hdr); kmem_cache_free(ocache, hdr); return (nhdr); } /* * This function is used by the send / receive code to convert a newly * allocated arc_buf_t to one that is suitable for a raw encrypted write. It * is also used to allow the root objset block to be updated without altering * its embedded MACs. Both block types will always be uncompressed so we do not * have to worry about compression type or psize. */ void arc_convert_to_raw(arc_buf_t *buf, uint64_t dsobj, boolean_t byteorder, dmu_object_type_t ot, const uint8_t *salt, const uint8_t *iv, const uint8_t *mac) { arc_buf_hdr_t *hdr = buf->b_hdr; ASSERT(ot == DMU_OT_DNODE || ot == DMU_OT_OBJSET); ASSERT(HDR_HAS_L1HDR(hdr)); ASSERT3P(hdr->b_l1hdr.b_state, ==, arc_anon); buf->b_flags |= (ARC_BUF_FLAG_COMPRESSED | ARC_BUF_FLAG_ENCRYPTED); if (!HDR_PROTECTED(hdr)) hdr = arc_hdr_realloc_crypt(hdr, B_TRUE); hdr->b_crypt_hdr.b_dsobj = dsobj; hdr->b_crypt_hdr.b_ot = ot; hdr->b_l1hdr.b_byteswap = (byteorder == ZFS_HOST_BYTEORDER) ? DMU_BSWAP_NUMFUNCS : DMU_OT_BYTESWAP(ot); if (!arc_hdr_has_uncompressed_buf(hdr)) arc_cksum_free(hdr); if (salt != NULL) bcopy(salt, hdr->b_crypt_hdr.b_salt, ZIO_DATA_SALT_LEN); if (iv != NULL) bcopy(iv, hdr->b_crypt_hdr.b_iv, ZIO_DATA_IV_LEN); if (mac != NULL) bcopy(mac, hdr->b_crypt_hdr.b_mac, ZIO_DATA_MAC_LEN); } /* * Allocate a new arc_buf_hdr_t and arc_buf_t and return the buf to the caller. * The buf is returned thawed since we expect the consumer to modify it. */ arc_buf_t * arc_alloc_buf(spa_t *spa, void *tag, arc_buf_contents_t type, int32_t size) { arc_buf_hdr_t *hdr = arc_hdr_alloc(spa_load_guid(spa), size, size, B_FALSE, ZIO_COMPRESS_OFF, 0, type, B_FALSE); arc_buf_t *buf = NULL; VERIFY0(arc_buf_alloc_impl(hdr, spa, NULL, tag, B_FALSE, B_FALSE, B_FALSE, B_FALSE, &buf)); arc_buf_thaw(buf); return (buf); } /* * Allocate a compressed buf in the same manner as arc_alloc_buf. Don't use this * for bufs containing metadata. */ arc_buf_t * arc_alloc_compressed_buf(spa_t *spa, void *tag, uint64_t psize, uint64_t lsize, enum zio_compress compression_type, uint8_t complevel) { ASSERT3U(lsize, >, 0); ASSERT3U(lsize, >=, psize); ASSERT3U(compression_type, >, ZIO_COMPRESS_OFF); ASSERT3U(compression_type, <, ZIO_COMPRESS_FUNCTIONS); arc_buf_hdr_t *hdr = arc_hdr_alloc(spa_load_guid(spa), psize, lsize, B_FALSE, compression_type, complevel, ARC_BUFC_DATA, B_FALSE); arc_buf_t *buf = NULL; VERIFY0(arc_buf_alloc_impl(hdr, spa, NULL, tag, B_FALSE, B_TRUE, B_FALSE, B_FALSE, &buf)); arc_buf_thaw(buf); ASSERT3P(hdr->b_l1hdr.b_freeze_cksum, ==, NULL); if (!arc_buf_is_shared(buf)) { /* * To ensure that the hdr has the correct data in it if we call * arc_untransform() on this buf before it's been written to * disk, it's easiest if we just set up sharing between the * buf and the hdr. */ arc_hdr_free_abd(hdr, B_FALSE); arc_share_buf(hdr, buf); } return (buf); } arc_buf_t * arc_alloc_raw_buf(spa_t *spa, void *tag, uint64_t dsobj, boolean_t byteorder, const uint8_t *salt, const uint8_t *iv, const uint8_t *mac, dmu_object_type_t ot, uint64_t psize, uint64_t lsize, enum zio_compress compression_type, uint8_t complevel) { arc_buf_hdr_t *hdr; arc_buf_t *buf; arc_buf_contents_t type = DMU_OT_IS_METADATA(ot) ? ARC_BUFC_METADATA : ARC_BUFC_DATA; ASSERT3U(lsize, >, 0); ASSERT3U(lsize, >=, psize); ASSERT3U(compression_type, >=, ZIO_COMPRESS_OFF); ASSERT3U(compression_type, <, ZIO_COMPRESS_FUNCTIONS); hdr = arc_hdr_alloc(spa_load_guid(spa), psize, lsize, B_TRUE, compression_type, complevel, type, B_TRUE); hdr->b_crypt_hdr.b_dsobj = dsobj; hdr->b_crypt_hdr.b_ot = ot; hdr->b_l1hdr.b_byteswap = (byteorder == ZFS_HOST_BYTEORDER) ? DMU_BSWAP_NUMFUNCS : DMU_OT_BYTESWAP(ot); bcopy(salt, hdr->b_crypt_hdr.b_salt, ZIO_DATA_SALT_LEN); bcopy(iv, hdr->b_crypt_hdr.b_iv, ZIO_DATA_IV_LEN); bcopy(mac, hdr->b_crypt_hdr.b_mac, ZIO_DATA_MAC_LEN); /* * This buffer will be considered encrypted even if the ot is not an * encrypted type. It will become authenticated instead in * arc_write_ready(). */ buf = NULL; VERIFY0(arc_buf_alloc_impl(hdr, spa, NULL, tag, B_TRUE, B_TRUE, B_FALSE, B_FALSE, &buf)); arc_buf_thaw(buf); ASSERT3P(hdr->b_l1hdr.b_freeze_cksum, ==, NULL); return (buf); } static void l2arc_hdr_arcstats_update(arc_buf_hdr_t *hdr, boolean_t incr, boolean_t state_only) { l2arc_buf_hdr_t *l2hdr = &hdr->b_l2hdr; l2arc_dev_t *dev = l2hdr->b_dev; uint64_t lsize = HDR_GET_LSIZE(hdr); uint64_t psize = HDR_GET_PSIZE(hdr); uint64_t asize = vdev_psize_to_asize(dev->l2ad_vdev, psize); arc_buf_contents_t type = hdr->b_type; int64_t lsize_s; int64_t psize_s; int64_t asize_s; if (incr) { lsize_s = lsize; psize_s = psize; asize_s = asize; } else { lsize_s = -lsize; psize_s = -psize; asize_s = -asize; } /* If the buffer is a prefetch, count it as such. */ if (HDR_PREFETCH(hdr)) { ARCSTAT_INCR(arcstat_l2_prefetch_asize, asize_s); } else { /* * We use the value stored in the L2 header upon initial * caching in L2ARC. This value will be updated in case * an MRU/MRU_ghost buffer transitions to MFU but the L2ARC * metadata (log entry) cannot currently be updated. Having * the ARC state in the L2 header solves the problem of a * possibly absent L1 header (apparent in buffers restored * from persistent L2ARC). */ switch (hdr->b_l2hdr.b_arcs_state) { case ARC_STATE_MRU_GHOST: case ARC_STATE_MRU: ARCSTAT_INCR(arcstat_l2_mru_asize, asize_s); break; case ARC_STATE_MFU_GHOST: case ARC_STATE_MFU: ARCSTAT_INCR(arcstat_l2_mfu_asize, asize_s); break; default: break; } } if (state_only) return; ARCSTAT_INCR(arcstat_l2_psize, psize_s); ARCSTAT_INCR(arcstat_l2_lsize, lsize_s); switch (type) { case ARC_BUFC_DATA: ARCSTAT_INCR(arcstat_l2_bufc_data_asize, asize_s); break; case ARC_BUFC_METADATA: ARCSTAT_INCR(arcstat_l2_bufc_metadata_asize, asize_s); break; default: break; } } static void arc_hdr_l2hdr_destroy(arc_buf_hdr_t *hdr) { l2arc_buf_hdr_t *l2hdr = &hdr->b_l2hdr; l2arc_dev_t *dev = l2hdr->b_dev; uint64_t psize = HDR_GET_PSIZE(hdr); uint64_t asize = vdev_psize_to_asize(dev->l2ad_vdev, psize); ASSERT(MUTEX_HELD(&dev->l2ad_mtx)); ASSERT(HDR_HAS_L2HDR(hdr)); list_remove(&dev->l2ad_buflist, hdr); l2arc_hdr_arcstats_decrement(hdr); vdev_space_update(dev->l2ad_vdev, -asize, 0, 0); (void) zfs_refcount_remove_many(&dev->l2ad_alloc, arc_hdr_size(hdr), hdr); arc_hdr_clear_flags(hdr, ARC_FLAG_HAS_L2HDR); } static void arc_hdr_destroy(arc_buf_hdr_t *hdr) { if (HDR_HAS_L1HDR(hdr)) { ASSERT(hdr->b_l1hdr.b_buf == NULL || hdr->b_l1hdr.b_bufcnt > 0); ASSERT(zfs_refcount_is_zero(&hdr->b_l1hdr.b_refcnt)); ASSERT3P(hdr->b_l1hdr.b_state, ==, arc_anon); } ASSERT(!HDR_IO_IN_PROGRESS(hdr)); ASSERT(!HDR_IN_HASH_TABLE(hdr)); if (HDR_HAS_L2HDR(hdr)) { l2arc_dev_t *dev = hdr->b_l2hdr.b_dev; boolean_t buflist_held = MUTEX_HELD(&dev->l2ad_mtx); if (!buflist_held) mutex_enter(&dev->l2ad_mtx); /* * Even though we checked this conditional above, we * need to check this again now that we have the * l2ad_mtx. This is because we could be racing with * another thread calling l2arc_evict() which might have * destroyed this header's L2 portion as we were waiting * to acquire the l2ad_mtx. If that happens, we don't * want to re-destroy the header's L2 portion. */ if (HDR_HAS_L2HDR(hdr)) arc_hdr_l2hdr_destroy(hdr); if (!buflist_held) mutex_exit(&dev->l2ad_mtx); } /* * The header's identify can only be safely discarded once it is no * longer discoverable. This requires removing it from the hash table * and the l2arc header list. After this point the hash lock can not * be used to protect the header. */ if (!HDR_EMPTY(hdr)) buf_discard_identity(hdr); if (HDR_HAS_L1HDR(hdr)) { arc_cksum_free(hdr); while (hdr->b_l1hdr.b_buf != NULL) arc_buf_destroy_impl(hdr->b_l1hdr.b_buf); if (hdr->b_l1hdr.b_pabd != NULL) arc_hdr_free_abd(hdr, B_FALSE); if (HDR_HAS_RABD(hdr)) arc_hdr_free_abd(hdr, B_TRUE); } ASSERT3P(hdr->b_hash_next, ==, NULL); if (HDR_HAS_L1HDR(hdr)) { ASSERT(!multilist_link_active(&hdr->b_l1hdr.b_arc_node)); ASSERT3P(hdr->b_l1hdr.b_acb, ==, NULL); if (!HDR_PROTECTED(hdr)) { kmem_cache_free(hdr_full_cache, hdr); } else { kmem_cache_free(hdr_full_crypt_cache, hdr); } } else { kmem_cache_free(hdr_l2only_cache, hdr); } } void arc_buf_destroy(arc_buf_t *buf, void* tag) { arc_buf_hdr_t *hdr = buf->b_hdr; if (hdr->b_l1hdr.b_state == arc_anon) { ASSERT3U(hdr->b_l1hdr.b_bufcnt, ==, 1); ASSERT(!HDR_IO_IN_PROGRESS(hdr)); VERIFY0(remove_reference(hdr, NULL, tag)); arc_hdr_destroy(hdr); return; } kmutex_t *hash_lock = HDR_LOCK(hdr); mutex_enter(hash_lock); ASSERT3P(hdr, ==, buf->b_hdr); ASSERT(hdr->b_l1hdr.b_bufcnt > 0); ASSERT3P(hash_lock, ==, HDR_LOCK(hdr)); ASSERT3P(hdr->b_l1hdr.b_state, !=, arc_anon); ASSERT3P(buf->b_data, !=, NULL); (void) remove_reference(hdr, hash_lock, tag); arc_buf_destroy_impl(buf); mutex_exit(hash_lock); } /* * Evict the arc_buf_hdr that is provided as a parameter. The resultant * state of the header is dependent on its state prior to entering this * function. The following transitions are possible: * * - arc_mru -> arc_mru_ghost * - arc_mfu -> arc_mfu_ghost * - arc_mru_ghost -> arc_l2c_only * - arc_mru_ghost -> deleted * - arc_mfu_ghost -> arc_l2c_only * - arc_mfu_ghost -> deleted */ static int64_t arc_evict_hdr(arc_buf_hdr_t *hdr, kmutex_t *hash_lock) { arc_state_t *evicted_state, *state; int64_t bytes_evicted = 0; int min_lifetime = HDR_PRESCIENT_PREFETCH(hdr) ? arc_min_prescient_prefetch_ms : arc_min_prefetch_ms; ASSERT(MUTEX_HELD(hash_lock)); ASSERT(HDR_HAS_L1HDR(hdr)); state = hdr->b_l1hdr.b_state; if (GHOST_STATE(state)) { ASSERT(!HDR_IO_IN_PROGRESS(hdr)); ASSERT3P(hdr->b_l1hdr.b_buf, ==, NULL); /* * l2arc_write_buffers() relies on a header's L1 portion * (i.e. its b_pabd field) during it's write phase. * Thus, we cannot push a header onto the arc_l2c_only * state (removing its L1 piece) until the header is * done being written to the l2arc. */ if (HDR_HAS_L2HDR(hdr) && HDR_L2_WRITING(hdr)) { ARCSTAT_BUMP(arcstat_evict_l2_skip); return (bytes_evicted); } ARCSTAT_BUMP(arcstat_deleted); bytes_evicted += HDR_GET_LSIZE(hdr); DTRACE_PROBE1(arc__delete, arc_buf_hdr_t *, hdr); if (HDR_HAS_L2HDR(hdr)) { ASSERT(hdr->b_l1hdr.b_pabd == NULL); ASSERT(!HDR_HAS_RABD(hdr)); /* * This buffer is cached on the 2nd Level ARC; * don't destroy the header. */ arc_change_state(arc_l2c_only, hdr, hash_lock); /* * dropping from L1+L2 cached to L2-only, * realloc to remove the L1 header. */ hdr = arc_hdr_realloc(hdr, hdr_full_cache, hdr_l2only_cache); } else { arc_change_state(arc_anon, hdr, hash_lock); arc_hdr_destroy(hdr); } return (bytes_evicted); } ASSERT(state == arc_mru || state == arc_mfu); evicted_state = (state == arc_mru) ? arc_mru_ghost : arc_mfu_ghost; /* prefetch buffers have a minimum lifespan */ if (HDR_IO_IN_PROGRESS(hdr) || ((hdr->b_flags & (ARC_FLAG_PREFETCH | ARC_FLAG_INDIRECT)) && ddi_get_lbolt() - hdr->b_l1hdr.b_arc_access < MSEC_TO_TICK(min_lifetime))) { ARCSTAT_BUMP(arcstat_evict_skip); return (bytes_evicted); } ASSERT0(zfs_refcount_count(&hdr->b_l1hdr.b_refcnt)); while (hdr->b_l1hdr.b_buf) { arc_buf_t *buf = hdr->b_l1hdr.b_buf; if (!mutex_tryenter(&buf->b_evict_lock)) { ARCSTAT_BUMP(arcstat_mutex_miss); break; } if (buf->b_data != NULL) bytes_evicted += HDR_GET_LSIZE(hdr); mutex_exit(&buf->b_evict_lock); arc_buf_destroy_impl(buf); } if (HDR_HAS_L2HDR(hdr)) { ARCSTAT_INCR(arcstat_evict_l2_cached, HDR_GET_LSIZE(hdr)); } else { if (l2arc_write_eligible(hdr->b_spa, hdr)) { ARCSTAT_INCR(arcstat_evict_l2_eligible, HDR_GET_LSIZE(hdr)); switch (state->arcs_state) { case ARC_STATE_MRU: ARCSTAT_INCR( arcstat_evict_l2_eligible_mru, HDR_GET_LSIZE(hdr)); break; case ARC_STATE_MFU: ARCSTAT_INCR( arcstat_evict_l2_eligible_mfu, HDR_GET_LSIZE(hdr)); break; default: break; } } else { ARCSTAT_INCR(arcstat_evict_l2_ineligible, HDR_GET_LSIZE(hdr)); } } if (hdr->b_l1hdr.b_bufcnt == 0) { arc_cksum_free(hdr); bytes_evicted += arc_hdr_size(hdr); /* * If this hdr is being evicted and has a compressed * buffer then we discard it here before we change states. * This ensures that the accounting is updated correctly * in arc_free_data_impl(). */ if (hdr->b_l1hdr.b_pabd != NULL) arc_hdr_free_abd(hdr, B_FALSE); if (HDR_HAS_RABD(hdr)) arc_hdr_free_abd(hdr, B_TRUE); arc_change_state(evicted_state, hdr, hash_lock); ASSERT(HDR_IN_HASH_TABLE(hdr)); arc_hdr_set_flags(hdr, ARC_FLAG_IN_HASH_TABLE); DTRACE_PROBE1(arc__evict, arc_buf_hdr_t *, hdr); } return (bytes_evicted); } static void arc_set_need_free(void) { ASSERT(MUTEX_HELD(&arc_evict_lock)); int64_t remaining = arc_free_memory() - arc_sys_free / 2; arc_evict_waiter_t *aw = list_tail(&arc_evict_waiters); if (aw == NULL) { arc_need_free = MAX(-remaining, 0); } else { arc_need_free = MAX(-remaining, (int64_t)(aw->aew_count - arc_evict_count)); } } static uint64_t arc_evict_state_impl(multilist_t *ml, int idx, arc_buf_hdr_t *marker, uint64_t spa, int64_t bytes) { multilist_sublist_t *mls; uint64_t bytes_evicted = 0; arc_buf_hdr_t *hdr; kmutex_t *hash_lock; int evict_count = 0; ASSERT3P(marker, !=, NULL); IMPLY(bytes < 0, bytes == ARC_EVICT_ALL); mls = multilist_sublist_lock(ml, idx); for (hdr = multilist_sublist_prev(mls, marker); hdr != NULL; hdr = multilist_sublist_prev(mls, marker)) { if ((bytes != ARC_EVICT_ALL && bytes_evicted >= bytes) || (evict_count >= zfs_arc_evict_batch_limit)) break; /* * To keep our iteration location, move the marker * forward. Since we're not holding hdr's hash lock, we * must be very careful and not remove 'hdr' from the * sublist. Otherwise, other consumers might mistake the * 'hdr' as not being on a sublist when they call the * multilist_link_active() function (they all rely on * the hash lock protecting concurrent insertions and * removals). multilist_sublist_move_forward() was * specifically implemented to ensure this is the case * (only 'marker' will be removed and re-inserted). */ multilist_sublist_move_forward(mls, marker); /* * The only case where the b_spa field should ever be * zero, is the marker headers inserted by * arc_evict_state(). It's possible for multiple threads * to be calling arc_evict_state() concurrently (e.g. * dsl_pool_close() and zio_inject_fault()), so we must * skip any markers we see from these other threads. */ if (hdr->b_spa == 0) continue; /* we're only interested in evicting buffers of a certain spa */ if (spa != 0 && hdr->b_spa != spa) { ARCSTAT_BUMP(arcstat_evict_skip); continue; } hash_lock = HDR_LOCK(hdr); /* * We aren't calling this function from any code path * that would already be holding a hash lock, so we're * asserting on this assumption to be defensive in case * this ever changes. Without this check, it would be * possible to incorrectly increment arcstat_mutex_miss * below (e.g. if the code changed such that we called * this function with a hash lock held). */ ASSERT(!MUTEX_HELD(hash_lock)); if (mutex_tryenter(hash_lock)) { uint64_t evicted = arc_evict_hdr(hdr, hash_lock); mutex_exit(hash_lock); bytes_evicted += evicted; /* * If evicted is zero, arc_evict_hdr() must have * decided to skip this header, don't increment * evict_count in this case. */ if (evicted != 0) evict_count++; } else { ARCSTAT_BUMP(arcstat_mutex_miss); } } multilist_sublist_unlock(mls); /* * Increment the count of evicted bytes, and wake up any threads that * are waiting for the count to reach this value. Since the list is * ordered by ascending aew_count, we pop off the beginning of the * list until we reach the end, or a waiter that's past the current * "count". Doing this outside the loop reduces the number of times * we need to acquire the global arc_evict_lock. * * Only wake when there's sufficient free memory in the system * (specifically, arc_sys_free/2, which by default is a bit more than * 1/64th of RAM). See the comments in arc_wait_for_eviction(). */ mutex_enter(&arc_evict_lock); arc_evict_count += bytes_evicted; if (arc_free_memory() > arc_sys_free / 2) { arc_evict_waiter_t *aw; while ((aw = list_head(&arc_evict_waiters)) != NULL && aw->aew_count <= arc_evict_count) { list_remove(&arc_evict_waiters, aw); cv_broadcast(&aw->aew_cv); } } arc_set_need_free(); mutex_exit(&arc_evict_lock); /* * If the ARC size is reduced from arc_c_max to arc_c_min (especially * if the average cached block is small), eviction can be on-CPU for * many seconds. To ensure that other threads that may be bound to * this CPU are able to make progress, make a voluntary preemption * call here. */ cond_resched(); return (bytes_evicted); } /* * Evict buffers from the given arc state, until we've removed the * specified number of bytes. Move the removed buffers to the * appropriate evict state. * * This function makes a "best effort". It skips over any buffers * it can't get a hash_lock on, and so, may not catch all candidates. * It may also return without evicting as much space as requested. * * If bytes is specified using the special value ARC_EVICT_ALL, this * will evict all available (i.e. unlocked and evictable) buffers from * the given arc state; which is used by arc_flush(). */ static uint64_t arc_evict_state(arc_state_t *state, uint64_t spa, int64_t bytes, arc_buf_contents_t type) { uint64_t total_evicted = 0; multilist_t *ml = state->arcs_list[type]; int num_sublists; arc_buf_hdr_t **markers; IMPLY(bytes < 0, bytes == ARC_EVICT_ALL); num_sublists = multilist_get_num_sublists(ml); /* * If we've tried to evict from each sublist, made some * progress, but still have not hit the target number of bytes * to evict, we want to keep trying. The markers allow us to * pick up where we left off for each individual sublist, rather * than starting from the tail each time. */ markers = kmem_zalloc(sizeof (*markers) * num_sublists, KM_SLEEP); for (int i = 0; i < num_sublists; i++) { multilist_sublist_t *mls; markers[i] = kmem_cache_alloc(hdr_full_cache, KM_SLEEP); /* * A b_spa of 0 is used to indicate that this header is * a marker. This fact is used in arc_evict_type() and * arc_evict_state_impl(). */ markers[i]->b_spa = 0; mls = multilist_sublist_lock(ml, i); multilist_sublist_insert_tail(mls, markers[i]); multilist_sublist_unlock(mls); } /* * While we haven't hit our target number of bytes to evict, or * we're evicting all available buffers. */ while (total_evicted < bytes || bytes == ARC_EVICT_ALL) { int sublist_idx = multilist_get_random_index(ml); uint64_t scan_evicted = 0; /* * Try to reduce pinned dnodes with a floor of arc_dnode_limit. * Request that 10% of the LRUs be scanned by the superblock * shrinker. */ if (type == ARC_BUFC_DATA && aggsum_compare(&astat_dnode_size, arc_dnode_size_limit) > 0) { arc_prune_async((aggsum_upper_bound(&astat_dnode_size) - arc_dnode_size_limit) / sizeof (dnode_t) / zfs_arc_dnode_reduce_percent); } /* * Start eviction using a randomly selected sublist, * this is to try and evenly balance eviction across all * sublists. Always starting at the same sublist * (e.g. index 0) would cause evictions to favor certain * sublists over others. */ for (int i = 0; i < num_sublists; i++) { uint64_t bytes_remaining; uint64_t bytes_evicted; if (bytes == ARC_EVICT_ALL) bytes_remaining = ARC_EVICT_ALL; else if (total_evicted < bytes) bytes_remaining = bytes - total_evicted; else break; bytes_evicted = arc_evict_state_impl(ml, sublist_idx, markers[sublist_idx], spa, bytes_remaining); scan_evicted += bytes_evicted; total_evicted += bytes_evicted; /* we've reached the end, wrap to the beginning */ if (++sublist_idx >= num_sublists) sublist_idx = 0; } /* * If we didn't evict anything during this scan, we have * no reason to believe we'll evict more during another * scan, so break the loop. */ if (scan_evicted == 0) { /* This isn't possible, let's make that obvious */ ASSERT3S(bytes, !=, 0); /* * When bytes is ARC_EVICT_ALL, the only way to * break the loop is when scan_evicted is zero. * In that case, we actually have evicted enough, * so we don't want to increment the kstat. */ if (bytes != ARC_EVICT_ALL) { ASSERT3S(total_evicted, <, bytes); ARCSTAT_BUMP(arcstat_evict_not_enough); } break; } } for (int i = 0; i < num_sublists; i++) { multilist_sublist_t *mls = multilist_sublist_lock(ml, i); multilist_sublist_remove(mls, markers[i]); multilist_sublist_unlock(mls); kmem_cache_free(hdr_full_cache, markers[i]); } kmem_free(markers, sizeof (*markers) * num_sublists); return (total_evicted); } /* * Flush all "evictable" data of the given type from the arc state * specified. This will not evict any "active" buffers (i.e. referenced). * * When 'retry' is set to B_FALSE, the function will make a single pass * over the state and evict any buffers that it can. Since it doesn't * continually retry the eviction, it might end up leaving some buffers * in the ARC due to lock misses. * * When 'retry' is set to B_TRUE, the function will continually retry the * eviction until *all* evictable buffers have been removed from the * state. As a result, if concurrent insertions into the state are * allowed (e.g. if the ARC isn't shutting down), this function might * wind up in an infinite loop, continually trying to evict buffers. */ static uint64_t arc_flush_state(arc_state_t *state, uint64_t spa, arc_buf_contents_t type, boolean_t retry) { uint64_t evicted = 0; while (zfs_refcount_count(&state->arcs_esize[type]) != 0) { evicted += arc_evict_state(state, spa, ARC_EVICT_ALL, type); if (!retry) break; } return (evicted); } /* * Evict the specified number of bytes from the state specified, * restricting eviction to the spa and type given. This function * prevents us from trying to evict more from a state's list than * is "evictable", and to skip evicting altogether when passed a * negative value for "bytes". In contrast, arc_evict_state() will * evict everything it can, when passed a negative value for "bytes". */ static uint64_t arc_evict_impl(arc_state_t *state, uint64_t spa, int64_t bytes, arc_buf_contents_t type) { int64_t delta; if (bytes > 0 && zfs_refcount_count(&state->arcs_esize[type]) > 0) { delta = MIN(zfs_refcount_count(&state->arcs_esize[type]), bytes); return (arc_evict_state(state, spa, delta, type)); } return (0); } /* * The goal of this function is to evict enough meta data buffers from the * ARC in order to enforce the arc_meta_limit. Achieving this is slightly * more complicated than it appears because it is common for data buffers * to have holds on meta data buffers. In addition, dnode meta data buffers * will be held by the dnodes in the block preventing them from being freed. * This means we can't simply traverse the ARC and expect to always find * enough unheld meta data buffer to release. * * Therefore, this function has been updated to make alternating passes * over the ARC releasing data buffers and then newly unheld meta data * buffers. This ensures forward progress is maintained and meta_used * will decrease. Normally this is sufficient, but if required the ARC * will call the registered prune callbacks causing dentry and inodes to * be dropped from the VFS cache. This will make dnode meta data buffers * available for reclaim. */ static uint64_t arc_evict_meta_balanced(uint64_t meta_used) { int64_t delta, prune = 0, adjustmnt; uint64_t total_evicted = 0; arc_buf_contents_t type = ARC_BUFC_DATA; int restarts = MAX(zfs_arc_meta_adjust_restarts, 0); restart: /* * This slightly differs than the way we evict from the mru in * arc_evict because we don't have a "target" value (i.e. no * "meta" arc_p). As a result, I think we can completely * cannibalize the metadata in the MRU before we evict the * metadata from the MFU. I think we probably need to implement a * "metadata arc_p" value to do this properly. */ adjustmnt = meta_used - arc_meta_limit; if (adjustmnt > 0 && zfs_refcount_count(&arc_mru->arcs_esize[type]) > 0) { delta = MIN(zfs_refcount_count(&arc_mru->arcs_esize[type]), adjustmnt); total_evicted += arc_evict_impl(arc_mru, 0, delta, type); adjustmnt -= delta; } /* * We can't afford to recalculate adjustmnt here. If we do, * new metadata buffers can sneak into the MRU or ANON lists, * thus penalize the MFU metadata. Although the fudge factor is * small, it has been empirically shown to be significant for * certain workloads (e.g. creating many empty directories). As * such, we use the original calculation for adjustmnt, and * simply decrement the amount of data evicted from the MRU. */ if (adjustmnt > 0 && zfs_refcount_count(&arc_mfu->arcs_esize[type]) > 0) { delta = MIN(zfs_refcount_count(&arc_mfu->arcs_esize[type]), adjustmnt); total_evicted += arc_evict_impl(arc_mfu, 0, delta, type); } adjustmnt = meta_used - arc_meta_limit; if (adjustmnt > 0 && zfs_refcount_count(&arc_mru_ghost->arcs_esize[type]) > 0) { delta = MIN(adjustmnt, zfs_refcount_count(&arc_mru_ghost->arcs_esize[type])); total_evicted += arc_evict_impl(arc_mru_ghost, 0, delta, type); adjustmnt -= delta; } if (adjustmnt > 0 && zfs_refcount_count(&arc_mfu_ghost->arcs_esize[type]) > 0) { delta = MIN(adjustmnt, zfs_refcount_count(&arc_mfu_ghost->arcs_esize[type])); total_evicted += arc_evict_impl(arc_mfu_ghost, 0, delta, type); } /* * If after attempting to make the requested adjustment to the ARC * the meta limit is still being exceeded then request that the * higher layers drop some cached objects which have holds on ARC * meta buffers. Requests to the upper layers will be made with * increasingly large scan sizes until the ARC is below the limit. */ if (meta_used > arc_meta_limit) { if (type == ARC_BUFC_DATA) { type = ARC_BUFC_METADATA; } else { type = ARC_BUFC_DATA; if (zfs_arc_meta_prune) { prune += zfs_arc_meta_prune; arc_prune_async(prune); } } if (restarts > 0) { restarts--; goto restart; } } return (total_evicted); } /* * Evict metadata buffers from the cache, such that arc_meta_used is * capped by the arc_meta_limit tunable. */ static uint64_t arc_evict_meta_only(uint64_t meta_used) { uint64_t total_evicted = 0; int64_t target; /* * If we're over the meta limit, we want to evict enough * metadata to get back under the meta limit. We don't want to * evict so much that we drop the MRU below arc_p, though. If * we're over the meta limit more than we're over arc_p, we * evict some from the MRU here, and some from the MFU below. */ target = MIN((int64_t)(meta_used - arc_meta_limit), (int64_t)(zfs_refcount_count(&arc_anon->arcs_size) + zfs_refcount_count(&arc_mru->arcs_size) - arc_p)); total_evicted += arc_evict_impl(arc_mru, 0, target, ARC_BUFC_METADATA); /* * Similar to the above, we want to evict enough bytes to get us * below the meta limit, but not so much as to drop us below the * space allotted to the MFU (which is defined as arc_c - arc_p). */ target = MIN((int64_t)(meta_used - arc_meta_limit), (int64_t)(zfs_refcount_count(&arc_mfu->arcs_size) - (arc_c - arc_p))); total_evicted += arc_evict_impl(arc_mfu, 0, target, ARC_BUFC_METADATA); return (total_evicted); } static uint64_t arc_evict_meta(uint64_t meta_used) { if (zfs_arc_meta_strategy == ARC_STRATEGY_META_ONLY) return (arc_evict_meta_only(meta_used)); else return (arc_evict_meta_balanced(meta_used)); } /* * Return the type of the oldest buffer in the given arc state * * This function will select a random sublist of type ARC_BUFC_DATA and * a random sublist of type ARC_BUFC_METADATA. The tail of each sublist * is compared, and the type which contains the "older" buffer will be * returned. */ static arc_buf_contents_t arc_evict_type(arc_state_t *state) { multilist_t *data_ml = state->arcs_list[ARC_BUFC_DATA]; multilist_t *meta_ml = state->arcs_list[ARC_BUFC_METADATA]; int data_idx = multilist_get_random_index(data_ml); int meta_idx = multilist_get_random_index(meta_ml); multilist_sublist_t *data_mls; multilist_sublist_t *meta_mls; arc_buf_contents_t type; arc_buf_hdr_t *data_hdr; arc_buf_hdr_t *meta_hdr; /* * We keep the sublist lock until we're finished, to prevent * the headers from being destroyed via arc_evict_state(). */ data_mls = multilist_sublist_lock(data_ml, data_idx); meta_mls = multilist_sublist_lock(meta_ml, meta_idx); /* * These two loops are to ensure we skip any markers that * might be at the tail of the lists due to arc_evict_state(). */ for (data_hdr = multilist_sublist_tail(data_mls); data_hdr != NULL; data_hdr = multilist_sublist_prev(data_mls, data_hdr)) { if (data_hdr->b_spa != 0) break; } for (meta_hdr = multilist_sublist_tail(meta_mls); meta_hdr != NULL; meta_hdr = multilist_sublist_prev(meta_mls, meta_hdr)) { if (meta_hdr->b_spa != 0) break; } if (data_hdr == NULL && meta_hdr == NULL) { type = ARC_BUFC_DATA; } else if (data_hdr == NULL) { ASSERT3P(meta_hdr, !=, NULL); type = ARC_BUFC_METADATA; } else if (meta_hdr == NULL) { ASSERT3P(data_hdr, !=, NULL); type = ARC_BUFC_DATA; } else { ASSERT3P(data_hdr, !=, NULL); ASSERT3P(meta_hdr, !=, NULL); /* The headers can't be on the sublist without an L1 header */ ASSERT(HDR_HAS_L1HDR(data_hdr)); ASSERT(HDR_HAS_L1HDR(meta_hdr)); if (data_hdr->b_l1hdr.b_arc_access < meta_hdr->b_l1hdr.b_arc_access) { type = ARC_BUFC_DATA; } else { type = ARC_BUFC_METADATA; } } multilist_sublist_unlock(meta_mls); multilist_sublist_unlock(data_mls); return (type); } /* * Evict buffers from the cache, such that arc_size is capped by arc_c. */ static uint64_t arc_evict(void) { uint64_t total_evicted = 0; uint64_t bytes; int64_t target; uint64_t asize = aggsum_value(&arc_size); uint64_t ameta = aggsum_value(&arc_meta_used); /* * If we're over arc_meta_limit, we want to correct that before * potentially evicting data buffers below. */ total_evicted += arc_evict_meta(ameta); /* * Adjust MRU size * * If we're over the target cache size, we want to evict enough * from the list to get back to our target size. We don't want * to evict too much from the MRU, such that it drops below * arc_p. So, if we're over our target cache size more than * the MRU is over arc_p, we'll evict enough to get back to * arc_p here, and then evict more from the MFU below. */ target = MIN((int64_t)(asize - arc_c), (int64_t)(zfs_refcount_count(&arc_anon->arcs_size) + zfs_refcount_count(&arc_mru->arcs_size) + ameta - arc_p)); /* * If we're below arc_meta_min, always prefer to evict data. * Otherwise, try to satisfy the requested number of bytes to * evict from the type which contains older buffers; in an * effort to keep newer buffers in the cache regardless of their * type. If we cannot satisfy the number of bytes from this * type, spill over into the next type. */ if (arc_evict_type(arc_mru) == ARC_BUFC_METADATA && ameta > arc_meta_min) { bytes = arc_evict_impl(arc_mru, 0, target, ARC_BUFC_METADATA); total_evicted += bytes; /* * If we couldn't evict our target number of bytes from * metadata, we try to get the rest from data. */ target -= bytes; total_evicted += arc_evict_impl(arc_mru, 0, target, ARC_BUFC_DATA); } else { bytes = arc_evict_impl(arc_mru, 0, target, ARC_BUFC_DATA); total_evicted += bytes; /* * If we couldn't evict our target number of bytes from * data, we try to get the rest from metadata. */ target -= bytes; total_evicted += arc_evict_impl(arc_mru, 0, target, ARC_BUFC_METADATA); } /* * Re-sum ARC stats after the first round of evictions. */ asize = aggsum_value(&arc_size); ameta = aggsum_value(&arc_meta_used); /* * Adjust MFU size * * Now that we've tried to evict enough from the MRU to get its * size back to arc_p, if we're still above the target cache * size, we evict the rest from the MFU. */ target = asize - arc_c; if (arc_evict_type(arc_mfu) == ARC_BUFC_METADATA && ameta > arc_meta_min) { bytes = arc_evict_impl(arc_mfu, 0, target, ARC_BUFC_METADATA); total_evicted += bytes; /* * If we couldn't evict our target number of bytes from * metadata, we try to get the rest from data. */ target -= bytes; total_evicted += arc_evict_impl(arc_mfu, 0, target, ARC_BUFC_DATA); } else { bytes = arc_evict_impl(arc_mfu, 0, target, ARC_BUFC_DATA); total_evicted += bytes; /* * If we couldn't evict our target number of bytes from * data, we try to get the rest from data. */ target -= bytes; total_evicted += arc_evict_impl(arc_mfu, 0, target, ARC_BUFC_METADATA); } /* * Adjust ghost lists * * In addition to the above, the ARC also defines target values * for the ghost lists. The sum of the mru list and mru ghost * list should never exceed the target size of the cache, and * the sum of the mru list, mfu list, mru ghost list, and mfu * ghost list should never exceed twice the target size of the * cache. The following logic enforces these limits on the ghost * caches, and evicts from them as needed. */ target = zfs_refcount_count(&arc_mru->arcs_size) + zfs_refcount_count(&arc_mru_ghost->arcs_size) - arc_c; bytes = arc_evict_impl(arc_mru_ghost, 0, target, ARC_BUFC_DATA); total_evicted += bytes; target -= bytes; total_evicted += arc_evict_impl(arc_mru_ghost, 0, target, ARC_BUFC_METADATA); /* * We assume the sum of the mru list and mfu list is less than * or equal to arc_c (we enforced this above), which means we * can use the simpler of the two equations below: * * mru + mfu + mru ghost + mfu ghost <= 2 * arc_c * mru ghost + mfu ghost <= arc_c */ target = zfs_refcount_count(&arc_mru_ghost->arcs_size) + zfs_refcount_count(&arc_mfu_ghost->arcs_size) - arc_c; bytes = arc_evict_impl(arc_mfu_ghost, 0, target, ARC_BUFC_DATA); total_evicted += bytes; target -= bytes; total_evicted += arc_evict_impl(arc_mfu_ghost, 0, target, ARC_BUFC_METADATA); return (total_evicted); } void arc_flush(spa_t *spa, boolean_t retry) { uint64_t guid = 0; /* * If retry is B_TRUE, a spa must not be specified since we have * no good way to determine if all of a spa's buffers have been * evicted from an arc state. */ ASSERT(!retry || spa == 0); if (spa != NULL) guid = spa_load_guid(spa); (void) arc_flush_state(arc_mru, guid, ARC_BUFC_DATA, retry); (void) arc_flush_state(arc_mru, guid, ARC_BUFC_METADATA, retry); (void) arc_flush_state(arc_mfu, guid, ARC_BUFC_DATA, retry); (void) arc_flush_state(arc_mfu, guid, ARC_BUFC_METADATA, retry); (void) arc_flush_state(arc_mru_ghost, guid, ARC_BUFC_DATA, retry); (void) arc_flush_state(arc_mru_ghost, guid, ARC_BUFC_METADATA, retry); (void) arc_flush_state(arc_mfu_ghost, guid, ARC_BUFC_DATA, retry); (void) arc_flush_state(arc_mfu_ghost, guid, ARC_BUFC_METADATA, retry); } void arc_reduce_target_size(int64_t to_free) { uint64_t asize = aggsum_value(&arc_size); /* * All callers want the ARC to actually evict (at least) this much * memory. Therefore we reduce from the lower of the current size and * the target size. This way, even if arc_c is much higher than * arc_size (as can be the case after many calls to arc_freed(), we will * immediately have arc_c < arc_size and therefore the arc_evict_zthr * will evict. */ uint64_t c = MIN(arc_c, asize); if (c > to_free && c - to_free > arc_c_min) { arc_c = c - to_free; atomic_add_64(&arc_p, -(arc_p >> arc_shrink_shift)); if (arc_p > arc_c) arc_p = (arc_c >> 1); ASSERT(arc_c >= arc_c_min); ASSERT((int64_t)arc_p >= 0); } else { arc_c = arc_c_min; } if (asize > arc_c) { /* See comment in arc_evict_cb_check() on why lock+flag */ mutex_enter(&arc_evict_lock); arc_evict_needed = B_TRUE; mutex_exit(&arc_evict_lock); zthr_wakeup(arc_evict_zthr); } } /* * Determine if the system is under memory pressure and is asking * to reclaim memory. A return value of B_TRUE indicates that the system * is under memory pressure and that the arc should adjust accordingly. */ boolean_t arc_reclaim_needed(void) { return (arc_available_memory() < 0); } void arc_kmem_reap_soon(void) { size_t i; kmem_cache_t *prev_cache = NULL; kmem_cache_t *prev_data_cache = NULL; extern kmem_cache_t *zio_buf_cache[]; extern kmem_cache_t *zio_data_buf_cache[]; #ifdef _KERNEL if ((aggsum_compare(&arc_meta_used, arc_meta_limit) >= 0) && zfs_arc_meta_prune) { /* * We are exceeding our meta-data cache limit. * Prune some entries to release holds on meta-data. */ arc_prune_async(zfs_arc_meta_prune); } #if defined(_ILP32) /* * Reclaim unused memory from all kmem caches. */ kmem_reap(); #endif #endif for (i = 0; i < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; i++) { #if defined(_ILP32) /* reach upper limit of cache size on 32-bit */ if (zio_buf_cache[i] == NULL) break; #endif if (zio_buf_cache[i] != prev_cache) { prev_cache = zio_buf_cache[i]; kmem_cache_reap_now(zio_buf_cache[i]); } if (zio_data_buf_cache[i] != prev_data_cache) { prev_data_cache = zio_data_buf_cache[i]; kmem_cache_reap_now(zio_data_buf_cache[i]); } } kmem_cache_reap_now(buf_cache); kmem_cache_reap_now(hdr_full_cache); kmem_cache_reap_now(hdr_l2only_cache); kmem_cache_reap_now(zfs_btree_leaf_cache); abd_cache_reap_now(); } /* ARGSUSED */ static boolean_t arc_evict_cb_check(void *arg, zthr_t *zthr) { #ifdef ZFS_DEBUG /* * This is necessary in order to keep the kstat information * up to date for tools that display kstat data such as the * mdb ::arc dcmd and the Linux crash utility. These tools * typically do not call kstat's update function, but simply * dump out stats from the most recent update. Without * this call, these commands may show stale stats for the * anon, mru, mru_ghost, mfu, and mfu_ghost lists. Even * with this call, the data might be out of date if the * evict thread hasn't been woken recently; but that should * suffice. The arc_state_t structures can be queried * directly if more accurate information is needed. */ if (arc_ksp != NULL) arc_ksp->ks_update(arc_ksp, KSTAT_READ); #endif /* * We have to rely on arc_wait_for_eviction() to tell us when to * evict, rather than checking if we are overflowing here, so that we * are sure to not leave arc_wait_for_eviction() waiting on aew_cv. * If we have become "not overflowing" since arc_wait_for_eviction() * checked, we need to wake it up. We could broadcast the CV here, * but arc_wait_for_eviction() may have not yet gone to sleep. We * would need to use a mutex to ensure that this function doesn't * broadcast until arc_wait_for_eviction() has gone to sleep (e.g. * the arc_evict_lock). However, the lock ordering of such a lock * would necessarily be incorrect with respect to the zthr_lock, * which is held before this function is called, and is held by * arc_wait_for_eviction() when it calls zthr_wakeup(). */ return (arc_evict_needed); } /* * Keep arc_size under arc_c by running arc_evict which evicts data * from the ARC. */ /* ARGSUSED */ static void arc_evict_cb(void *arg, zthr_t *zthr) { uint64_t evicted = 0; fstrans_cookie_t cookie = spl_fstrans_mark(); /* Evict from cache */ evicted = arc_evict(); /* * If evicted is zero, we couldn't evict anything * via arc_evict(). This could be due to hash lock * collisions, but more likely due to the majority of * arc buffers being unevictable. Therefore, even if * arc_size is above arc_c, another pass is unlikely to * be helpful and could potentially cause us to enter an * infinite loop. Additionally, zthr_iscancelled() is * checked here so that if the arc is shutting down, the * broadcast will wake any remaining arc evict waiters. */ mutex_enter(&arc_evict_lock); arc_evict_needed = !zthr_iscancelled(arc_evict_zthr) && evicted > 0 && aggsum_compare(&arc_size, arc_c) > 0; if (!arc_evict_needed) { /* * We're either no longer overflowing, or we * can't evict anything more, so we should wake * arc_get_data_impl() sooner. */ arc_evict_waiter_t *aw; while ((aw = list_remove_head(&arc_evict_waiters)) != NULL) { cv_broadcast(&aw->aew_cv); } arc_set_need_free(); } mutex_exit(&arc_evict_lock); spl_fstrans_unmark(cookie); } /* ARGSUSED */ static boolean_t arc_reap_cb_check(void *arg, zthr_t *zthr) { int64_t free_memory = arc_available_memory(); static int reap_cb_check_counter = 0; /* * If a kmem reap is already active, don't schedule more. We must * check for this because kmem_cache_reap_soon() won't actually * block on the cache being reaped (this is to prevent callers from * becoming implicitly blocked by a system-wide kmem reap -- which, * on a system with many, many full magazines, can take minutes). */ if (!kmem_cache_reap_active() && free_memory < 0) { arc_no_grow = B_TRUE; arc_warm = B_TRUE; /* * Wait at least zfs_grow_retry (default 5) seconds * before considering growing. */ arc_growtime = gethrtime() + SEC2NSEC(arc_grow_retry); return (B_TRUE); } else if (free_memory < arc_c >> arc_no_grow_shift) { arc_no_grow = B_TRUE; } else if (gethrtime() >= arc_growtime) { arc_no_grow = B_FALSE; } /* * Called unconditionally every 60 seconds to reclaim unused * zstd compression and decompression context. This is done * here to avoid the need for an independent thread. */ if (!((reap_cb_check_counter++) % 60)) zfs_zstd_cache_reap_now(); return (B_FALSE); } /* * Keep enough free memory in the system by reaping the ARC's kmem * caches. To cause more slabs to be reapable, we may reduce the * target size of the cache (arc_c), causing the arc_evict_cb() * to free more buffers. */ /* ARGSUSED */ static void arc_reap_cb(void *arg, zthr_t *zthr) { int64_t free_memory; fstrans_cookie_t cookie = spl_fstrans_mark(); /* * Kick off asynchronous kmem_reap()'s of all our caches. */ arc_kmem_reap_soon(); /* * Wait at least arc_kmem_cache_reap_retry_ms between * arc_kmem_reap_soon() calls. Without this check it is possible to * end up in a situation where we spend lots of time reaping * caches, while we're near arc_c_min. Waiting here also gives the * subsequent free memory check a chance of finding that the * asynchronous reap has already freed enough memory, and we don't * need to call arc_reduce_target_size(). */ delay((hz * arc_kmem_cache_reap_retry_ms + 999) / 1000); /* * Reduce the target size as needed to maintain the amount of free * memory in the system at a fraction of the arc_size (1/128th by * default). If oversubscribed (free_memory < 0) then reduce the * target arc_size by the deficit amount plus the fractional * amount. If free memory is positive but less then the fractional * amount, reduce by what is needed to hit the fractional amount. */ free_memory = arc_available_memory(); int64_t to_free = (arc_c >> arc_shrink_shift) - free_memory; if (to_free > 0) { arc_reduce_target_size(to_free); } spl_fstrans_unmark(cookie); } #ifdef _KERNEL /* * Determine the amount of memory eligible for eviction contained in the * ARC. All clean data reported by the ghost lists can always be safely * evicted. Due to arc_c_min, the same does not hold for all clean data * contained by the regular mru and mfu lists. * * In the case of the regular mru and mfu lists, we need to report as * much clean data as possible, such that evicting that same reported * data will not bring arc_size below arc_c_min. Thus, in certain * circumstances, the total amount of clean data in the mru and mfu * lists might not actually be evictable. * * The following two distinct cases are accounted for: * * 1. The sum of the amount of dirty data contained by both the mru and * mfu lists, plus the ARC's other accounting (e.g. the anon list), * is greater than or equal to arc_c_min. * (i.e. amount of dirty data >= arc_c_min) * * This is the easy case; all clean data contained by the mru and mfu * lists is evictable. Evicting all clean data can only drop arc_size * to the amount of dirty data, which is greater than arc_c_min. * * 2. The sum of the amount of dirty data contained by both the mru and * mfu lists, plus the ARC's other accounting (e.g. the anon list), * is less than arc_c_min. * (i.e. arc_c_min > amount of dirty data) * * 2.1. arc_size is greater than or equal arc_c_min. * (i.e. arc_size >= arc_c_min > amount of dirty data) * * In this case, not all clean data from the regular mru and mfu * lists is actually evictable; we must leave enough clean data * to keep arc_size above arc_c_min. Thus, the maximum amount of * evictable data from the two lists combined, is exactly the * difference between arc_size and arc_c_min. * * 2.2. arc_size is less than arc_c_min * (i.e. arc_c_min > arc_size > amount of dirty data) * * In this case, none of the data contained in the mru and mfu * lists is evictable, even if it's clean. Since arc_size is * already below arc_c_min, evicting any more would only * increase this negative difference. */ #endif /* _KERNEL */ /* * Adapt arc info given the number of bytes we are trying to add and * the state that we are coming from. This function is only called * when we are adding new content to the cache. */ static void arc_adapt(int bytes, arc_state_t *state) { int mult; uint64_t arc_p_min = (arc_c >> arc_p_min_shift); int64_t mrug_size = zfs_refcount_count(&arc_mru_ghost->arcs_size); int64_t mfug_size = zfs_refcount_count(&arc_mfu_ghost->arcs_size); ASSERT(bytes > 0); /* * Adapt the target size of the MRU list: * - if we just hit in the MRU ghost list, then increase * the target size of the MRU list. * - if we just hit in the MFU ghost list, then increase * the target size of the MFU list by decreasing the * target size of the MRU list. */ if (state == arc_mru_ghost) { mult = (mrug_size >= mfug_size) ? 1 : (mfug_size / mrug_size); if (!zfs_arc_p_dampener_disable) mult = MIN(mult, 10); /* avoid wild arc_p adjustment */ arc_p = MIN(arc_c - arc_p_min, arc_p + bytes * mult); } else if (state == arc_mfu_ghost) { uint64_t delta; mult = (mfug_size >= mrug_size) ? 1 : (mrug_size / mfug_size); if (!zfs_arc_p_dampener_disable) mult = MIN(mult, 10); delta = MIN(bytes * mult, arc_p); arc_p = MAX(arc_p_min, arc_p - delta); } ASSERT((int64_t)arc_p >= 0); /* * Wake reap thread if we do not have any available memory */ if (arc_reclaim_needed()) { zthr_wakeup(arc_reap_zthr); return; } if (arc_no_grow) return; if (arc_c >= arc_c_max) return; /* * If we're within (2 * maxblocksize) bytes of the target * cache size, increment the target cache size */ ASSERT3U(arc_c, >=, 2ULL << SPA_MAXBLOCKSHIFT); if (aggsum_upper_bound(&arc_size) >= arc_c - (2ULL << SPA_MAXBLOCKSHIFT)) { atomic_add_64(&arc_c, (int64_t)bytes); if (arc_c > arc_c_max) arc_c = arc_c_max; else if (state == arc_anon) atomic_add_64(&arc_p, (int64_t)bytes); if (arc_p > arc_c) arc_p = arc_c; } ASSERT((int64_t)arc_p >= 0); } /* * Check if arc_size has grown past our upper threshold, determined by * zfs_arc_overflow_shift. */ boolean_t arc_is_overflowing(void) { /* Always allow at least one block of overflow */ int64_t overflow = MAX(SPA_MAXBLOCKSIZE, arc_c >> zfs_arc_overflow_shift); /* * We just compare the lower bound here for performance reasons. Our * primary goals are to make sure that the arc never grows without * bound, and that it can reach its maximum size. This check * accomplishes both goals. The maximum amount we could run over by is * 2 * aggsum_borrow_multiplier * NUM_CPUS * the average size of a block * in the ARC. In practice, that's in the tens of MB, which is low * enough to be safe. */ return (aggsum_lower_bound(&arc_size) >= (int64_t)arc_c + overflow); } static abd_t * arc_get_data_abd(arc_buf_hdr_t *hdr, uint64_t size, void *tag, boolean_t do_adapt) { arc_buf_contents_t type = arc_buf_type(hdr); arc_get_data_impl(hdr, size, tag, do_adapt); if (type == ARC_BUFC_METADATA) { return (abd_alloc(size, B_TRUE)); } else { ASSERT(type == ARC_BUFC_DATA); return (abd_alloc(size, B_FALSE)); } } static void * arc_get_data_buf(arc_buf_hdr_t *hdr, uint64_t size, void *tag) { arc_buf_contents_t type = arc_buf_type(hdr); arc_get_data_impl(hdr, size, tag, B_TRUE); if (type == ARC_BUFC_METADATA) { return (zio_buf_alloc(size)); } else { ASSERT(type == ARC_BUFC_DATA); return (zio_data_buf_alloc(size)); } } /* * Wait for the specified amount of data (in bytes) to be evicted from the * ARC, and for there to be sufficient free memory in the system. Waiting for * eviction ensures that the memory used by the ARC decreases. Waiting for * free memory ensures that the system won't run out of free pages, regardless * of ARC behavior and settings. See arc_lowmem_init(). */ void arc_wait_for_eviction(uint64_t amount) { mutex_enter(&arc_evict_lock); if (arc_is_overflowing()) { arc_evict_needed = B_TRUE; zthr_wakeup(arc_evict_zthr); if (amount != 0) { arc_evict_waiter_t aw; list_link_init(&aw.aew_node); cv_init(&aw.aew_cv, NULL, CV_DEFAULT, NULL); uint64_t last_count = 0; if (!list_is_empty(&arc_evict_waiters)) { arc_evict_waiter_t *last = list_tail(&arc_evict_waiters); last_count = last->aew_count; } /* * Note, the last waiter's count may be less than * arc_evict_count if we are low on memory in which * case arc_evict_state_impl() may have deferred * wakeups (but still incremented arc_evict_count). */ aw.aew_count = MAX(last_count, arc_evict_count) + amount; list_insert_tail(&arc_evict_waiters, &aw); arc_set_need_free(); DTRACE_PROBE3(arc__wait__for__eviction, uint64_t, amount, uint64_t, arc_evict_count, uint64_t, aw.aew_count); /* * We will be woken up either when arc_evict_count * reaches aew_count, or when the ARC is no longer * overflowing and eviction completes. */ cv_wait(&aw.aew_cv, &arc_evict_lock); /* * In case of "false" wakeup, we will still be on the * list. */ if (list_link_active(&aw.aew_node)) list_remove(&arc_evict_waiters, &aw); cv_destroy(&aw.aew_cv); } } mutex_exit(&arc_evict_lock); } /* * Allocate a block and return it to the caller. If we are hitting the * hard limit for the cache size, we must sleep, waiting for the eviction * thread to catch up. If we're past the target size but below the hard * limit, we'll only signal the reclaim thread and continue on. */ static void arc_get_data_impl(arc_buf_hdr_t *hdr, uint64_t size, void *tag, boolean_t do_adapt) { arc_state_t *state = hdr->b_l1hdr.b_state; arc_buf_contents_t type = arc_buf_type(hdr); if (do_adapt) arc_adapt(size, state); /* * If arc_size is currently overflowing, we must be adding data * faster than we are evicting. To ensure we don't compound the * problem by adding more data and forcing arc_size to grow even * further past it's target size, we wait for the eviction thread to * make some progress. We also wait for there to be sufficient free * memory in the system, as measured by arc_free_memory(). * * Specifically, we wait for zfs_arc_eviction_pct percent of the * requested size to be evicted. This should be more than 100%, to * ensure that that progress is also made towards getting arc_size * under arc_c. See the comment above zfs_arc_eviction_pct. * * We do the overflowing check without holding the arc_evict_lock to * reduce lock contention in this hot path. Note that * arc_wait_for_eviction() will acquire the lock and check again to * ensure we are truly overflowing before blocking. */ if (arc_is_overflowing()) { arc_wait_for_eviction(size * zfs_arc_eviction_pct / 100); } VERIFY3U(hdr->b_type, ==, type); if (type == ARC_BUFC_METADATA) { arc_space_consume(size, ARC_SPACE_META); } else { arc_space_consume(size, ARC_SPACE_DATA); } /* * Update the state size. Note that ghost states have a * "ghost size" and so don't need to be updated. */ if (!GHOST_STATE(state)) { (void) zfs_refcount_add_many(&state->arcs_size, size, tag); /* * If this is reached via arc_read, the link is * protected by the hash lock. If reached via * arc_buf_alloc, the header should not be accessed by * any other thread. And, if reached via arc_read_done, * the hash lock will protect it if it's found in the * hash table; otherwise no other thread should be * trying to [add|remove]_reference it. */ if (multilist_link_active(&hdr->b_l1hdr.b_arc_node)) { ASSERT(zfs_refcount_is_zero(&hdr->b_l1hdr.b_refcnt)); (void) zfs_refcount_add_many(&state->arcs_esize[type], size, tag); } /* * If we are growing the cache, and we are adding anonymous * data, and we have outgrown arc_p, update arc_p */ if (aggsum_upper_bound(&arc_size) < arc_c && hdr->b_l1hdr.b_state == arc_anon && (zfs_refcount_count(&arc_anon->arcs_size) + zfs_refcount_count(&arc_mru->arcs_size) > arc_p)) arc_p = MIN(arc_c, arc_p + size); } } static void arc_free_data_abd(arc_buf_hdr_t *hdr, abd_t *abd, uint64_t size, void *tag) { arc_free_data_impl(hdr, size, tag); abd_free(abd); } static void arc_free_data_buf(arc_buf_hdr_t *hdr, void *buf, uint64_t size, void *tag) { arc_buf_contents_t type = arc_buf_type(hdr); arc_free_data_impl(hdr, size, tag); if (type == ARC_BUFC_METADATA) { zio_buf_free(buf, size); } else { ASSERT(type == ARC_BUFC_DATA); zio_data_buf_free(buf, size); } } /* * Free the arc data buffer. */ static void arc_free_data_impl(arc_buf_hdr_t *hdr, uint64_t size, void *tag) { arc_state_t *state = hdr->b_l1hdr.b_state; arc_buf_contents_t type = arc_buf_type(hdr); /* protected by hash lock, if in the hash table */ if (multilist_link_active(&hdr->b_l1hdr.b_arc_node)) { ASSERT(zfs_refcount_is_zero(&hdr->b_l1hdr.b_refcnt)); ASSERT(state != arc_anon && state != arc_l2c_only); (void) zfs_refcount_remove_many(&state->arcs_esize[type], size, tag); } (void) zfs_refcount_remove_many(&state->arcs_size, size, tag); VERIFY3U(hdr->b_type, ==, type); if (type == ARC_BUFC_METADATA) { arc_space_return(size, ARC_SPACE_META); } else { ASSERT(type == ARC_BUFC_DATA); arc_space_return(size, ARC_SPACE_DATA); } } /* * This routine is called whenever a buffer is accessed. * NOTE: the hash lock is dropped in this function. */ static void arc_access(arc_buf_hdr_t *hdr, kmutex_t *hash_lock) { clock_t now; ASSERT(MUTEX_HELD(hash_lock)); ASSERT(HDR_HAS_L1HDR(hdr)); if (hdr->b_l1hdr.b_state == arc_anon) { /* * This buffer is not in the cache, and does not * appear in our "ghost" list. Add the new buffer * to the MRU state. */ ASSERT0(hdr->b_l1hdr.b_arc_access); hdr->b_l1hdr.b_arc_access = ddi_get_lbolt(); DTRACE_PROBE1(new_state__mru, arc_buf_hdr_t *, hdr); arc_change_state(arc_mru, hdr, hash_lock); } else if (hdr->b_l1hdr.b_state == arc_mru) { now = ddi_get_lbolt(); /* * If this buffer is here because of a prefetch, then either: * - clear the flag if this is a "referencing" read * (any subsequent access will bump this into the MFU state). * or * - move the buffer to the head of the list if this is * another prefetch (to make it less likely to be evicted). */ if (HDR_PREFETCH(hdr) || HDR_PRESCIENT_PREFETCH(hdr)) { if (zfs_refcount_count(&hdr->b_l1hdr.b_refcnt) == 0) { /* link protected by hash lock */ ASSERT(multilist_link_active( &hdr->b_l1hdr.b_arc_node)); } else { if (HDR_HAS_L2HDR(hdr)) l2arc_hdr_arcstats_decrement_state(hdr); arc_hdr_clear_flags(hdr, ARC_FLAG_PREFETCH | ARC_FLAG_PRESCIENT_PREFETCH); atomic_inc_32(&hdr->b_l1hdr.b_mru_hits); ARCSTAT_BUMP(arcstat_mru_hits); if (HDR_HAS_L2HDR(hdr)) l2arc_hdr_arcstats_increment_state(hdr); } hdr->b_l1hdr.b_arc_access = now; return; } /* * This buffer has been "accessed" only once so far, * but it is still in the cache. Move it to the MFU * state. */ if (ddi_time_after(now, hdr->b_l1hdr.b_arc_access + ARC_MINTIME)) { /* * More than 125ms have passed since we * instantiated this buffer. Move it to the * most frequently used state. */ hdr->b_l1hdr.b_arc_access = now; DTRACE_PROBE1(new_state__mfu, arc_buf_hdr_t *, hdr); arc_change_state(arc_mfu, hdr, hash_lock); } atomic_inc_32(&hdr->b_l1hdr.b_mru_hits); ARCSTAT_BUMP(arcstat_mru_hits); } else if (hdr->b_l1hdr.b_state == arc_mru_ghost) { arc_state_t *new_state; /* * This buffer has been "accessed" recently, but * was evicted from the cache. Move it to the * MFU state. */ if (HDR_PREFETCH(hdr) || HDR_PRESCIENT_PREFETCH(hdr)) { new_state = arc_mru; if (zfs_refcount_count(&hdr->b_l1hdr.b_refcnt) > 0) { if (HDR_HAS_L2HDR(hdr)) l2arc_hdr_arcstats_decrement_state(hdr); arc_hdr_clear_flags(hdr, ARC_FLAG_PREFETCH | ARC_FLAG_PRESCIENT_PREFETCH); if (HDR_HAS_L2HDR(hdr)) l2arc_hdr_arcstats_increment_state(hdr); } DTRACE_PROBE1(new_state__mru, arc_buf_hdr_t *, hdr); } else { new_state = arc_mfu; DTRACE_PROBE1(new_state__mfu, arc_buf_hdr_t *, hdr); } hdr->b_l1hdr.b_arc_access = ddi_get_lbolt(); arc_change_state(new_state, hdr, hash_lock); atomic_inc_32(&hdr->b_l1hdr.b_mru_ghost_hits); ARCSTAT_BUMP(arcstat_mru_ghost_hits); } else if (hdr->b_l1hdr.b_state == arc_mfu) { /* * This buffer has been accessed more than once and is * still in the cache. Keep it in the MFU state. * * NOTE: an add_reference() that occurred when we did * the arc_read() will have kicked this off the list. * If it was a prefetch, we will explicitly move it to * the head of the list now. */ atomic_inc_32(&hdr->b_l1hdr.b_mfu_hits); ARCSTAT_BUMP(arcstat_mfu_hits); hdr->b_l1hdr.b_arc_access = ddi_get_lbolt(); } else if (hdr->b_l1hdr.b_state == arc_mfu_ghost) { arc_state_t *new_state = arc_mfu; /* * This buffer has been accessed more than once but has * been evicted from the cache. Move it back to the * MFU state. */ if (HDR_PREFETCH(hdr) || HDR_PRESCIENT_PREFETCH(hdr)) { /* * This is a prefetch access... * move this block back to the MRU state. */ new_state = arc_mru; } hdr->b_l1hdr.b_arc_access = ddi_get_lbolt(); DTRACE_PROBE1(new_state__mfu, arc_buf_hdr_t *, hdr); arc_change_state(new_state, hdr, hash_lock); atomic_inc_32(&hdr->b_l1hdr.b_mfu_ghost_hits); ARCSTAT_BUMP(arcstat_mfu_ghost_hits); } else if (hdr->b_l1hdr.b_state == arc_l2c_only) { /* * This buffer is on the 2nd Level ARC. */ hdr->b_l1hdr.b_arc_access = ddi_get_lbolt(); DTRACE_PROBE1(new_state__mfu, arc_buf_hdr_t *, hdr); arc_change_state(arc_mfu, hdr, hash_lock); } else { cmn_err(CE_PANIC, "invalid arc state 0x%p", hdr->b_l1hdr.b_state); } } /* * This routine is called by dbuf_hold() to update the arc_access() state * which otherwise would be skipped for entries in the dbuf cache. */ void arc_buf_access(arc_buf_t *buf) { mutex_enter(&buf->b_evict_lock); arc_buf_hdr_t *hdr = buf->b_hdr; /* * Avoid taking the hash_lock when possible as an optimization. * The header must be checked again under the hash_lock in order * to handle the case where it is concurrently being released. */ if (hdr->b_l1hdr.b_state == arc_anon || HDR_EMPTY(hdr)) { mutex_exit(&buf->b_evict_lock); return; } kmutex_t *hash_lock = HDR_LOCK(hdr); mutex_enter(hash_lock); if (hdr->b_l1hdr.b_state == arc_anon || HDR_EMPTY(hdr)) { mutex_exit(hash_lock); mutex_exit(&buf->b_evict_lock); ARCSTAT_BUMP(arcstat_access_skip); return; } mutex_exit(&buf->b_evict_lock); ASSERT(hdr->b_l1hdr.b_state == arc_mru || hdr->b_l1hdr.b_state == arc_mfu); DTRACE_PROBE1(arc__hit, arc_buf_hdr_t *, hdr); arc_access(hdr, hash_lock); mutex_exit(hash_lock); ARCSTAT_BUMP(arcstat_hits); ARCSTAT_CONDSTAT(!HDR_PREFETCH(hdr) && !HDR_PRESCIENT_PREFETCH(hdr), demand, prefetch, !HDR_ISTYPE_METADATA(hdr), data, metadata, hits); } /* a generic arc_read_done_func_t which you can use */ /* ARGSUSED */ void arc_bcopy_func(zio_t *zio, const zbookmark_phys_t *zb, const blkptr_t *bp, arc_buf_t *buf, void *arg) { if (buf == NULL) return; bcopy(buf->b_data, arg, arc_buf_size(buf)); arc_buf_destroy(buf, arg); } /* a generic arc_read_done_func_t */ /* ARGSUSED */ void arc_getbuf_func(zio_t *zio, const zbookmark_phys_t *zb, const blkptr_t *bp, arc_buf_t *buf, void *arg) { arc_buf_t **bufp = arg; if (buf == NULL) { ASSERT(zio == NULL || zio->io_error != 0); *bufp = NULL; } else { ASSERT(zio == NULL || zio->io_error == 0); *bufp = buf; ASSERT(buf->b_data != NULL); } } static void arc_hdr_verify(arc_buf_hdr_t *hdr, blkptr_t *bp) { if (BP_IS_HOLE(bp) || BP_IS_EMBEDDED(bp)) { ASSERT3U(HDR_GET_PSIZE(hdr), ==, 0); ASSERT3U(arc_hdr_get_compress(hdr), ==, ZIO_COMPRESS_OFF); } else { if (HDR_COMPRESSION_ENABLED(hdr)) { ASSERT3U(arc_hdr_get_compress(hdr), ==, BP_GET_COMPRESS(bp)); } ASSERT3U(HDR_GET_LSIZE(hdr), ==, BP_GET_LSIZE(bp)); ASSERT3U(HDR_GET_PSIZE(hdr), ==, BP_GET_PSIZE(bp)); ASSERT3U(!!HDR_PROTECTED(hdr), ==, BP_IS_PROTECTED(bp)); } } static void arc_read_done(zio_t *zio) { blkptr_t *bp = zio->io_bp; arc_buf_hdr_t *hdr = zio->io_private; kmutex_t *hash_lock = NULL; arc_callback_t *callback_list; arc_callback_t *acb; boolean_t freeable = B_FALSE; /* * The hdr was inserted into hash-table and removed from lists * prior to starting I/O. We should find this header, since * it's in the hash table, and it should be legit since it's * not possible to evict it during the I/O. The only possible * reason for it not to be found is if we were freed during the * read. */ if (HDR_IN_HASH_TABLE(hdr)) { arc_buf_hdr_t *found; ASSERT3U(hdr->b_birth, ==, BP_PHYSICAL_BIRTH(zio->io_bp)); ASSERT3U(hdr->b_dva.dva_word[0], ==, BP_IDENTITY(zio->io_bp)->dva_word[0]); ASSERT3U(hdr->b_dva.dva_word[1], ==, BP_IDENTITY(zio->io_bp)->dva_word[1]); found = buf_hash_find(hdr->b_spa, zio->io_bp, &hash_lock); ASSERT((found == hdr && DVA_EQUAL(&hdr->b_dva, BP_IDENTITY(zio->io_bp))) || (found == hdr && HDR_L2_READING(hdr))); ASSERT3P(hash_lock, !=, NULL); } if (BP_IS_PROTECTED(bp)) { hdr->b_crypt_hdr.b_ot = BP_GET_TYPE(bp); hdr->b_crypt_hdr.b_dsobj = zio->io_bookmark.zb_objset; zio_crypt_decode_params_bp(bp, hdr->b_crypt_hdr.b_salt, hdr->b_crypt_hdr.b_iv); if (BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG) { void *tmpbuf; tmpbuf = abd_borrow_buf_copy(zio->io_abd, sizeof (zil_chain_t)); zio_crypt_decode_mac_zil(tmpbuf, hdr->b_crypt_hdr.b_mac); abd_return_buf(zio->io_abd, tmpbuf, sizeof (zil_chain_t)); } else { zio_crypt_decode_mac_bp(bp, hdr->b_crypt_hdr.b_mac); } } if (zio->io_error == 0) { /* byteswap if necessary */ if (BP_SHOULD_BYTESWAP(zio->io_bp)) { if (BP_GET_LEVEL(zio->io_bp) > 0) { hdr->b_l1hdr.b_byteswap = DMU_BSWAP_UINT64; } else { hdr->b_l1hdr.b_byteswap = DMU_OT_BYTESWAP(BP_GET_TYPE(zio->io_bp)); } } else { hdr->b_l1hdr.b_byteswap = DMU_BSWAP_NUMFUNCS; } if (!HDR_L2_READING(hdr)) { hdr->b_complevel = zio->io_prop.zp_complevel; } } arc_hdr_clear_flags(hdr, ARC_FLAG_L2_EVICTED); if (l2arc_noprefetch && HDR_PREFETCH(hdr)) arc_hdr_clear_flags(hdr, ARC_FLAG_L2CACHE); callback_list = hdr->b_l1hdr.b_acb; ASSERT3P(callback_list, !=, NULL); if (hash_lock && zio->io_error == 0 && hdr->b_l1hdr.b_state == arc_anon) { /* * Only call arc_access on anonymous buffers. This is because * if we've issued an I/O for an evicted buffer, we've already * called arc_access (to prevent any simultaneous readers from * getting confused). */ arc_access(hdr, hash_lock); } /* * If a read request has a callback (i.e. acb_done is not NULL), then we * make a buf containing the data according to the parameters which were * passed in. The implementation of arc_buf_alloc_impl() ensures that we * aren't needlessly decompressing the data multiple times. */ int callback_cnt = 0; for (acb = callback_list; acb != NULL; acb = acb->acb_next) { if (!acb->acb_done || acb->acb_nobuf) continue; callback_cnt++; if (zio->io_error != 0) continue; int error = arc_buf_alloc_impl(hdr, zio->io_spa, &acb->acb_zb, acb->acb_private, acb->acb_encrypted, acb->acb_compressed, acb->acb_noauth, B_TRUE, &acb->acb_buf); /* * Assert non-speculative zios didn't fail because an * encryption key wasn't loaded */ ASSERT((zio->io_flags & ZIO_FLAG_SPECULATIVE) || error != EACCES); /* * If we failed to decrypt, report an error now (as the zio * layer would have done if it had done the transforms). */ if (error == ECKSUM) { ASSERT(BP_IS_PROTECTED(bp)); error = SET_ERROR(EIO); if ((zio->io_flags & ZIO_FLAG_SPECULATIVE) == 0) { spa_log_error(zio->io_spa, &acb->acb_zb); (void) zfs_ereport_post( FM_EREPORT_ZFS_AUTHENTICATION, zio->io_spa, NULL, &acb->acb_zb, zio, 0); } } if (error != 0) { /* * Decompression or decryption failed. Set * io_error so that when we call acb_done * (below), we will indicate that the read * failed. Note that in the unusual case * where one callback is compressed and another * uncompressed, we will mark all of them * as failed, even though the uncompressed * one can't actually fail. In this case, * the hdr will not be anonymous, because * if there are multiple callbacks, it's * because multiple threads found the same * arc buf in the hash table. */ zio->io_error = error; } } /* * If there are multiple callbacks, we must have the hash lock, * because the only way for multiple threads to find this hdr is * in the hash table. This ensures that if there are multiple * callbacks, the hdr is not anonymous. If it were anonymous, * we couldn't use arc_buf_destroy() in the error case below. */ ASSERT(callback_cnt < 2 || hash_lock != NULL); hdr->b_l1hdr.b_acb = NULL; arc_hdr_clear_flags(hdr, ARC_FLAG_IO_IN_PROGRESS); if (callback_cnt == 0) ASSERT(hdr->b_l1hdr.b_pabd != NULL || HDR_HAS_RABD(hdr)); ASSERT(zfs_refcount_is_zero(&hdr->b_l1hdr.b_refcnt) || callback_list != NULL); if (zio->io_error == 0) { arc_hdr_verify(hdr, zio->io_bp); } else { arc_hdr_set_flags(hdr, ARC_FLAG_IO_ERROR); if (hdr->b_l1hdr.b_state != arc_anon) arc_change_state(arc_anon, hdr, hash_lock); if (HDR_IN_HASH_TABLE(hdr)) buf_hash_remove(hdr); freeable = zfs_refcount_is_zero(&hdr->b_l1hdr.b_refcnt); } /* * Broadcast before we drop the hash_lock to avoid the possibility * that the hdr (and hence the cv) might be freed before we get to * the cv_broadcast(). */ cv_broadcast(&hdr->b_l1hdr.b_cv); if (hash_lock != NULL) { mutex_exit(hash_lock); } else { /* * This block was freed while we waited for the read to * complete. It has been removed from the hash table and * moved to the anonymous state (so that it won't show up * in the cache). */ ASSERT3P(hdr->b_l1hdr.b_state, ==, arc_anon); freeable = zfs_refcount_is_zero(&hdr->b_l1hdr.b_refcnt); } /* execute each callback and free its structure */ while ((acb = callback_list) != NULL) { if (acb->acb_done != NULL) { if (zio->io_error != 0 && acb->acb_buf != NULL) { /* * If arc_buf_alloc_impl() fails during * decompression, the buf will still be * allocated, and needs to be freed here. */ arc_buf_destroy(acb->acb_buf, acb->acb_private); acb->acb_buf = NULL; } acb->acb_done(zio, &zio->io_bookmark, zio->io_bp, acb->acb_buf, acb->acb_private); } if (acb->acb_zio_dummy != NULL) { acb->acb_zio_dummy->io_error = zio->io_error; zio_nowait(acb->acb_zio_dummy); } callback_list = acb->acb_next; kmem_free(acb, sizeof (arc_callback_t)); } if (freeable) arc_hdr_destroy(hdr); } /* * "Read" the block at the specified DVA (in bp) via the * cache. If the block is found in the cache, invoke the provided * callback immediately and return. Note that the `zio' parameter * in the callback will be NULL in this case, since no IO was * required. If the block is not in the cache pass the read request * on to the spa with a substitute callback function, so that the * requested block will be added to the cache. * * If a read request arrives for a block that has a read in-progress, * either wait for the in-progress read to complete (and return the * results); or, if this is a read with a "done" func, add a record * to the read to invoke the "done" func when the read completes, * and return; or just return. * * arc_read_done() will invoke all the requested "done" functions * for readers of this block. */ int arc_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, arc_read_done_func_t *done, void *private, zio_priority_t priority, int zio_flags, arc_flags_t *arc_flags, const zbookmark_phys_t *zb) { arc_buf_hdr_t *hdr = NULL; kmutex_t *hash_lock = NULL; zio_t *rzio; uint64_t guid = spa_load_guid(spa); boolean_t compressed_read = (zio_flags & ZIO_FLAG_RAW_COMPRESS) != 0; boolean_t encrypted_read = BP_IS_ENCRYPTED(bp) && (zio_flags & ZIO_FLAG_RAW_ENCRYPT) != 0; boolean_t noauth_read = BP_IS_AUTHENTICATED(bp) && (zio_flags & ZIO_FLAG_RAW_ENCRYPT) != 0; boolean_t embedded_bp = !!BP_IS_EMBEDDED(bp); boolean_t no_buf = *arc_flags & ARC_FLAG_NO_BUF; int rc = 0; ASSERT(!embedded_bp || BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA); ASSERT(!BP_IS_HOLE(bp)); ASSERT(!BP_IS_REDACTED(bp)); /* * Normally SPL_FSTRANS will already be set since kernel threads which * expect to call the DMU interfaces will set it when created. System * calls are similarly handled by setting/cleaning the bit in the * registered callback (module/os/.../zfs/zpl_*). * * External consumers such as Lustre which call the exported DMU * interfaces may not have set SPL_FSTRANS. To avoid a deadlock * on the hash_lock always set and clear the bit. */ fstrans_cookie_t cookie = spl_fstrans_mark(); top: if (!embedded_bp) { /* * Embedded BP's have no DVA and require no I/O to "read". * Create an anonymous arc buf to back it. */ hdr = buf_hash_find(guid, bp, &hash_lock); } /* * Determine if we have an L1 cache hit or a cache miss. For simplicity * we maintain encrypted data separately from compressed / uncompressed * data. If the user is requesting raw encrypted data and we don't have * that in the header we will read from disk to guarantee that we can * get it even if the encryption keys aren't loaded. */ if (hdr != NULL && HDR_HAS_L1HDR(hdr) && (HDR_HAS_RABD(hdr) || (hdr->b_l1hdr.b_pabd != NULL && !encrypted_read))) { arc_buf_t *buf = NULL; *arc_flags |= ARC_FLAG_CACHED; if (HDR_IO_IN_PROGRESS(hdr)) { zio_t *head_zio = hdr->b_l1hdr.b_acb->acb_zio_head; if (*arc_flags & ARC_FLAG_CACHED_ONLY) { mutex_exit(hash_lock); ARCSTAT_BUMP(arcstat_cached_only_in_progress); rc = SET_ERROR(ENOENT); goto out; } ASSERT3P(head_zio, !=, NULL); if ((hdr->b_flags & ARC_FLAG_PRIO_ASYNC_READ) && priority == ZIO_PRIORITY_SYNC_READ) { /* * This is a sync read that needs to wait for * an in-flight async read. Request that the * zio have its priority upgraded. */ zio_change_priority(head_zio, priority); DTRACE_PROBE1(arc__async__upgrade__sync, arc_buf_hdr_t *, hdr); ARCSTAT_BUMP(arcstat_async_upgrade_sync); } if (hdr->b_flags & ARC_FLAG_PREDICTIVE_PREFETCH) { arc_hdr_clear_flags(hdr, ARC_FLAG_PREDICTIVE_PREFETCH); } if (*arc_flags & ARC_FLAG_WAIT) { cv_wait(&hdr->b_l1hdr.b_cv, hash_lock); mutex_exit(hash_lock); goto top; } ASSERT(*arc_flags & ARC_FLAG_NOWAIT); if (done) { arc_callback_t *acb = NULL; acb = kmem_zalloc(sizeof (arc_callback_t), KM_SLEEP); acb->acb_done = done; acb->acb_private = private; acb->acb_compressed = compressed_read; acb->acb_encrypted = encrypted_read; acb->acb_noauth = noauth_read; acb->acb_nobuf = no_buf; acb->acb_zb = *zb; if (pio != NULL) acb->acb_zio_dummy = zio_null(pio, spa, NULL, NULL, NULL, zio_flags); ASSERT3P(acb->acb_done, !=, NULL); acb->acb_zio_head = head_zio; acb->acb_next = hdr->b_l1hdr.b_acb; hdr->b_l1hdr.b_acb = acb; } mutex_exit(hash_lock); goto out; } ASSERT(hdr->b_l1hdr.b_state == arc_mru || hdr->b_l1hdr.b_state == arc_mfu); if (done && !no_buf) { if (hdr->b_flags & ARC_FLAG_PREDICTIVE_PREFETCH) { /* * This is a demand read which does not have to * wait for i/o because we did a predictive * prefetch i/o for it, which has completed. */ DTRACE_PROBE1( arc__demand__hit__predictive__prefetch, arc_buf_hdr_t *, hdr); ARCSTAT_BUMP( arcstat_demand_hit_predictive_prefetch); arc_hdr_clear_flags(hdr, ARC_FLAG_PREDICTIVE_PREFETCH); } if (hdr->b_flags & ARC_FLAG_PRESCIENT_PREFETCH) { ARCSTAT_BUMP( arcstat_demand_hit_prescient_prefetch); arc_hdr_clear_flags(hdr, ARC_FLAG_PRESCIENT_PREFETCH); } ASSERT(!embedded_bp || !BP_IS_HOLE(bp)); /* Get a buf with the desired data in it. */ rc = arc_buf_alloc_impl(hdr, spa, zb, private, encrypted_read, compressed_read, noauth_read, B_TRUE, &buf); if (rc == ECKSUM) { /* * Convert authentication and decryption errors * to EIO (and generate an ereport if needed) * before leaving the ARC. */ rc = SET_ERROR(EIO); if ((zio_flags & ZIO_FLAG_SPECULATIVE) == 0) { spa_log_error(spa, zb); (void) zfs_ereport_post( FM_EREPORT_ZFS_AUTHENTICATION, spa, NULL, zb, NULL, 0); } } if (rc != 0) { (void) remove_reference(hdr, hash_lock, private); arc_buf_destroy_impl(buf); buf = NULL; } /* assert any errors weren't due to unloaded keys */ ASSERT((zio_flags & ZIO_FLAG_SPECULATIVE) || rc != EACCES); } else if (*arc_flags & ARC_FLAG_PREFETCH && zfs_refcount_is_zero(&hdr->b_l1hdr.b_refcnt)) { if (HDR_HAS_L2HDR(hdr)) l2arc_hdr_arcstats_decrement_state(hdr); arc_hdr_set_flags(hdr, ARC_FLAG_PREFETCH); if (HDR_HAS_L2HDR(hdr)) l2arc_hdr_arcstats_increment_state(hdr); } DTRACE_PROBE1(arc__hit, arc_buf_hdr_t *, hdr); arc_access(hdr, hash_lock); if (*arc_flags & ARC_FLAG_PRESCIENT_PREFETCH) arc_hdr_set_flags(hdr, ARC_FLAG_PRESCIENT_PREFETCH); if (*arc_flags & ARC_FLAG_L2CACHE) arc_hdr_set_flags(hdr, ARC_FLAG_L2CACHE); mutex_exit(hash_lock); ARCSTAT_BUMP(arcstat_hits); ARCSTAT_CONDSTAT(!HDR_PREFETCH(hdr), demand, prefetch, !HDR_ISTYPE_METADATA(hdr), data, metadata, hits); if (done) done(NULL, zb, bp, buf, private); } else { uint64_t lsize = BP_GET_LSIZE(bp); uint64_t psize = BP_GET_PSIZE(bp); arc_callback_t *acb; vdev_t *vd = NULL; uint64_t addr = 0; boolean_t devw = B_FALSE; uint64_t size; abd_t *hdr_abd; int alloc_flags = encrypted_read ? ARC_HDR_ALLOC_RDATA : 0; if (*arc_flags & ARC_FLAG_CACHED_ONLY) { rc = SET_ERROR(ENOENT); if (hash_lock != NULL) mutex_exit(hash_lock); goto out; } /* * Gracefully handle a damaged logical block size as a * checksum error. */ if (lsize > spa_maxblocksize(spa)) { rc = SET_ERROR(ECKSUM); if (hash_lock != NULL) mutex_exit(hash_lock); goto out; } if (hdr == NULL) { /* * This block is not in the cache or it has * embedded data. */ arc_buf_hdr_t *exists = NULL; arc_buf_contents_t type = BP_GET_BUFC_TYPE(bp); hdr = arc_hdr_alloc(spa_load_guid(spa), psize, lsize, BP_IS_PROTECTED(bp), BP_GET_COMPRESS(bp), 0, type, encrypted_read); if (!embedded_bp) { hdr->b_dva = *BP_IDENTITY(bp); hdr->b_birth = BP_PHYSICAL_BIRTH(bp); exists = buf_hash_insert(hdr, &hash_lock); } if (exists != NULL) { /* somebody beat us to the hash insert */ mutex_exit(hash_lock); buf_discard_identity(hdr); arc_hdr_destroy(hdr); goto top; /* restart the IO request */ } } else { /* * This block is in the ghost cache or encrypted data * was requested and we didn't have it. If it was * L2-only (and thus didn't have an L1 hdr), * we realloc the header to add an L1 hdr. */ if (!HDR_HAS_L1HDR(hdr)) { hdr = arc_hdr_realloc(hdr, hdr_l2only_cache, hdr_full_cache); } if (GHOST_STATE(hdr->b_l1hdr.b_state)) { ASSERT3P(hdr->b_l1hdr.b_pabd, ==, NULL); ASSERT(!HDR_HAS_RABD(hdr)); ASSERT(!HDR_IO_IN_PROGRESS(hdr)); ASSERT0(zfs_refcount_count( &hdr->b_l1hdr.b_refcnt)); ASSERT3P(hdr->b_l1hdr.b_buf, ==, NULL); ASSERT3P(hdr->b_l1hdr.b_freeze_cksum, ==, NULL); } else if (HDR_IO_IN_PROGRESS(hdr)) { /* * If this header already had an IO in progress * and we are performing another IO to fetch * encrypted data we must wait until the first * IO completes so as not to confuse * arc_read_done(). This should be very rare * and so the performance impact shouldn't * matter. */ cv_wait(&hdr->b_l1hdr.b_cv, hash_lock); mutex_exit(hash_lock); goto top; } /* * This is a delicate dance that we play here. * This hdr might be in the ghost list so we access * it to move it out of the ghost list before we * initiate the read. If it's a prefetch then * it won't have a callback so we'll remove the * reference that arc_buf_alloc_impl() created. We * do this after we've called arc_access() to * avoid hitting an assert in remove_reference(). */ arc_adapt(arc_hdr_size(hdr), hdr->b_l1hdr.b_state); arc_access(hdr, hash_lock); arc_hdr_alloc_abd(hdr, alloc_flags); } if (encrypted_read) { ASSERT(HDR_HAS_RABD(hdr)); size = HDR_GET_PSIZE(hdr); hdr_abd = hdr->b_crypt_hdr.b_rabd; zio_flags |= ZIO_FLAG_RAW; } else { ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL); size = arc_hdr_size(hdr); hdr_abd = hdr->b_l1hdr.b_pabd; if (arc_hdr_get_compress(hdr) != ZIO_COMPRESS_OFF) { zio_flags |= ZIO_FLAG_RAW_COMPRESS; } /* * For authenticated bp's, we do not ask the ZIO layer * to authenticate them since this will cause the entire * IO to fail if the key isn't loaded. Instead, we * defer authentication until arc_buf_fill(), which will * verify the data when the key is available. */ if (BP_IS_AUTHENTICATED(bp)) zio_flags |= ZIO_FLAG_RAW_ENCRYPT; } if (*arc_flags & ARC_FLAG_PREFETCH && zfs_refcount_is_zero(&hdr->b_l1hdr.b_refcnt)) { if (HDR_HAS_L2HDR(hdr)) l2arc_hdr_arcstats_decrement_state(hdr); arc_hdr_set_flags(hdr, ARC_FLAG_PREFETCH); if (HDR_HAS_L2HDR(hdr)) l2arc_hdr_arcstats_increment_state(hdr); } if (*arc_flags & ARC_FLAG_PRESCIENT_PREFETCH) arc_hdr_set_flags(hdr, ARC_FLAG_PRESCIENT_PREFETCH); if (*arc_flags & ARC_FLAG_L2CACHE) arc_hdr_set_flags(hdr, ARC_FLAG_L2CACHE); if (BP_IS_AUTHENTICATED(bp)) arc_hdr_set_flags(hdr, ARC_FLAG_NOAUTH); if (BP_GET_LEVEL(bp) > 0) arc_hdr_set_flags(hdr, ARC_FLAG_INDIRECT); if (*arc_flags & ARC_FLAG_PREDICTIVE_PREFETCH) arc_hdr_set_flags(hdr, ARC_FLAG_PREDICTIVE_PREFETCH); ASSERT(!GHOST_STATE(hdr->b_l1hdr.b_state)); acb = kmem_zalloc(sizeof (arc_callback_t), KM_SLEEP); acb->acb_done = done; acb->acb_private = private; acb->acb_compressed = compressed_read; acb->acb_encrypted = encrypted_read; acb->acb_noauth = noauth_read; acb->acb_zb = *zb; ASSERT3P(hdr->b_l1hdr.b_acb, ==, NULL); hdr->b_l1hdr.b_acb = acb; arc_hdr_set_flags(hdr, ARC_FLAG_IO_IN_PROGRESS); if (HDR_HAS_L2HDR(hdr) && (vd = hdr->b_l2hdr.b_dev->l2ad_vdev) != NULL) { devw = hdr->b_l2hdr.b_dev->l2ad_writing; addr = hdr->b_l2hdr.b_daddr; /* * Lock out L2ARC device removal. */ if (vdev_is_dead(vd) || !spa_config_tryenter(spa, SCL_L2ARC, vd, RW_READER)) vd = NULL; } /* * We count both async reads and scrub IOs as asynchronous so * that both can be upgraded in the event of a cache hit while * the read IO is still in-flight. */ if (priority == ZIO_PRIORITY_ASYNC_READ || priority == ZIO_PRIORITY_SCRUB) arc_hdr_set_flags(hdr, ARC_FLAG_PRIO_ASYNC_READ); else arc_hdr_clear_flags(hdr, ARC_FLAG_PRIO_ASYNC_READ); /* * At this point, we have a level 1 cache miss or a blkptr * with embedded data. Try again in L2ARC if possible. */ ASSERT3U(HDR_GET_LSIZE(hdr), ==, lsize); /* * Skip ARC stat bump for block pointers with embedded * data. The data are read from the blkptr itself via * decode_embedded_bp_compressed(). */ if (!embedded_bp) { DTRACE_PROBE4(arc__miss, arc_buf_hdr_t *, hdr, blkptr_t *, bp, uint64_t, lsize, zbookmark_phys_t *, zb); ARCSTAT_BUMP(arcstat_misses); ARCSTAT_CONDSTAT(!HDR_PREFETCH(hdr), demand, prefetch, !HDR_ISTYPE_METADATA(hdr), data, metadata, misses); } /* Check if the spa even has l2 configured */ const boolean_t spa_has_l2 = l2arc_ndev != 0 && spa->spa_l2cache.sav_count > 0; if (vd != NULL && spa_has_l2 && !(l2arc_norw && devw)) { /* * Read from the L2ARC if the following are true: * 1. The L2ARC vdev was previously cached. * 2. This buffer still has L2ARC metadata. * 3. This buffer isn't currently writing to the L2ARC. * 4. The L2ARC entry wasn't evicted, which may * also have invalidated the vdev. * 5. This isn't prefetch or l2arc_noprefetch is 0. */ if (HDR_HAS_L2HDR(hdr) && !HDR_L2_WRITING(hdr) && !HDR_L2_EVICTED(hdr) && !(l2arc_noprefetch && HDR_PREFETCH(hdr))) { l2arc_read_callback_t *cb; abd_t *abd; uint64_t asize; DTRACE_PROBE1(l2arc__hit, arc_buf_hdr_t *, hdr); ARCSTAT_BUMP(arcstat_l2_hits); atomic_inc_32(&hdr->b_l2hdr.b_hits); cb = kmem_zalloc(sizeof (l2arc_read_callback_t), KM_SLEEP); cb->l2rcb_hdr = hdr; cb->l2rcb_bp = *bp; cb->l2rcb_zb = *zb; cb->l2rcb_flags = zio_flags; /* * When Compressed ARC is disabled, but the * L2ARC block is compressed, arc_hdr_size() * will have returned LSIZE rather than PSIZE. */ if (HDR_GET_COMPRESS(hdr) != ZIO_COMPRESS_OFF && !HDR_COMPRESSION_ENABLED(hdr) && HDR_GET_PSIZE(hdr) != 0) { size = HDR_GET_PSIZE(hdr); } asize = vdev_psize_to_asize(vd, size); if (asize != size) { abd = abd_alloc_for_io(asize, HDR_ISTYPE_METADATA(hdr)); cb->l2rcb_abd = abd; } else { abd = hdr_abd; } ASSERT(addr >= VDEV_LABEL_START_SIZE && addr + asize <= vd->vdev_psize - VDEV_LABEL_END_SIZE); /* * l2arc read. The SCL_L2ARC lock will be * released by l2arc_read_done(). * Issue a null zio if the underlying buffer * was squashed to zero size by compression. */ ASSERT3U(arc_hdr_get_compress(hdr), !=, ZIO_COMPRESS_EMPTY); rzio = zio_read_phys(pio, vd, addr, asize, abd, ZIO_CHECKSUM_OFF, l2arc_read_done, cb, priority, zio_flags | ZIO_FLAG_DONT_CACHE | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY, B_FALSE); acb->acb_zio_head = rzio; if (hash_lock != NULL) mutex_exit(hash_lock); DTRACE_PROBE2(l2arc__read, vdev_t *, vd, zio_t *, rzio); ARCSTAT_INCR(arcstat_l2_read_bytes, HDR_GET_PSIZE(hdr)); if (*arc_flags & ARC_FLAG_NOWAIT) { zio_nowait(rzio); goto out; } ASSERT(*arc_flags & ARC_FLAG_WAIT); if (zio_wait(rzio) == 0) goto out; /* l2arc read error; goto zio_read() */ if (hash_lock != NULL) mutex_enter(hash_lock); } else { DTRACE_PROBE1(l2arc__miss, arc_buf_hdr_t *, hdr); ARCSTAT_BUMP(arcstat_l2_misses); if (HDR_L2_WRITING(hdr)) ARCSTAT_BUMP(arcstat_l2_rw_clash); spa_config_exit(spa, SCL_L2ARC, vd); } } else { if (vd != NULL) spa_config_exit(spa, SCL_L2ARC, vd); /* * Only a spa with l2 should contribute to l2 * miss stats. (Including the case of having a * faulted cache device - that's also a miss.) */ if (spa_has_l2) { /* * Skip ARC stat bump for block pointers with * embedded data. The data are read from the * blkptr itself via * decode_embedded_bp_compressed(). */ if (!embedded_bp) { DTRACE_PROBE1(l2arc__miss, arc_buf_hdr_t *, hdr); ARCSTAT_BUMP(arcstat_l2_misses); } } } rzio = zio_read(pio, spa, bp, hdr_abd, size, arc_read_done, hdr, priority, zio_flags, zb); acb->acb_zio_head = rzio; if (hash_lock != NULL) mutex_exit(hash_lock); if (*arc_flags & ARC_FLAG_WAIT) { rc = zio_wait(rzio); goto out; } ASSERT(*arc_flags & ARC_FLAG_NOWAIT); zio_nowait(rzio); } out: /* embedded bps don't actually go to disk */ if (!embedded_bp) spa_read_history_add(spa, zb, *arc_flags); spl_fstrans_unmark(cookie); return (rc); } arc_prune_t * arc_add_prune_callback(arc_prune_func_t *func, void *private) { arc_prune_t *p; p = kmem_alloc(sizeof (*p), KM_SLEEP); p->p_pfunc = func; p->p_private = private; list_link_init(&p->p_node); zfs_refcount_create(&p->p_refcnt); mutex_enter(&arc_prune_mtx); zfs_refcount_add(&p->p_refcnt, &arc_prune_list); list_insert_head(&arc_prune_list, p); mutex_exit(&arc_prune_mtx); return (p); } void arc_remove_prune_callback(arc_prune_t *p) { boolean_t wait = B_FALSE; mutex_enter(&arc_prune_mtx); list_remove(&arc_prune_list, p); if (zfs_refcount_remove(&p->p_refcnt, &arc_prune_list) > 0) wait = B_TRUE; mutex_exit(&arc_prune_mtx); /* wait for arc_prune_task to finish */ if (wait) taskq_wait_outstanding(arc_prune_taskq, 0); ASSERT0(zfs_refcount_count(&p->p_refcnt)); zfs_refcount_destroy(&p->p_refcnt); kmem_free(p, sizeof (*p)); } /* * Notify the arc that a block was freed, and thus will never be used again. */ void arc_freed(spa_t *spa, const blkptr_t *bp) { arc_buf_hdr_t *hdr; kmutex_t *hash_lock; uint64_t guid = spa_load_guid(spa); ASSERT(!BP_IS_EMBEDDED(bp)); hdr = buf_hash_find(guid, bp, &hash_lock); if (hdr == NULL) return; /* * We might be trying to free a block that is still doing I/O * (i.e. prefetch) or has a reference (i.e. a dedup-ed, * dmu_sync-ed block). If this block is being prefetched, then it * would still have the ARC_FLAG_IO_IN_PROGRESS flag set on the hdr * until the I/O completes. A block may also have a reference if it is * part of a dedup-ed, dmu_synced write. The dmu_sync() function would * have written the new block to its final resting place on disk but * without the dedup flag set. This would have left the hdr in the MRU * state and discoverable. When the txg finally syncs it detects that * the block was overridden in open context and issues an override I/O. * Since this is a dedup block, the override I/O will determine if the * block is already in the DDT. If so, then it will replace the io_bp * with the bp from the DDT and allow the I/O to finish. When the I/O * reaches the done callback, dbuf_write_override_done, it will * check to see if the io_bp and io_bp_override are identical. * If they are not, then it indicates that the bp was replaced with * the bp in the DDT and the override bp is freed. This allows * us to arrive here with a reference on a block that is being * freed. So if we have an I/O in progress, or a reference to * this hdr, then we don't destroy the hdr. */ if (!HDR_HAS_L1HDR(hdr) || (!HDR_IO_IN_PROGRESS(hdr) && zfs_refcount_is_zero(&hdr->b_l1hdr.b_refcnt))) { arc_change_state(arc_anon, hdr, hash_lock); arc_hdr_destroy(hdr); mutex_exit(hash_lock); } else { mutex_exit(hash_lock); } } /* * Release this buffer from the cache, making it an anonymous buffer. This * must be done after a read and prior to modifying the buffer contents. * If the buffer has more than one reference, we must make * a new hdr for the buffer. */ void arc_release(arc_buf_t *buf, void *tag) { arc_buf_hdr_t *hdr = buf->b_hdr; /* * It would be nice to assert that if its DMU metadata (level > * 0 || it's the dnode file), then it must be syncing context. * But we don't know that information at this level. */ mutex_enter(&buf->b_evict_lock); ASSERT(HDR_HAS_L1HDR(hdr)); /* * We don't grab the hash lock prior to this check, because if * the buffer's header is in the arc_anon state, it won't be * linked into the hash table. */ if (hdr->b_l1hdr.b_state == arc_anon) { mutex_exit(&buf->b_evict_lock); ASSERT(!HDR_IO_IN_PROGRESS(hdr)); ASSERT(!HDR_IN_HASH_TABLE(hdr)); ASSERT(!HDR_HAS_L2HDR(hdr)); ASSERT(HDR_EMPTY(hdr)); ASSERT3U(hdr->b_l1hdr.b_bufcnt, ==, 1); ASSERT3S(zfs_refcount_count(&hdr->b_l1hdr.b_refcnt), ==, 1); ASSERT(!list_link_active(&hdr->b_l1hdr.b_arc_node)); hdr->b_l1hdr.b_arc_access = 0; /* * If the buf is being overridden then it may already * have a hdr that is not empty. */ buf_discard_identity(hdr); arc_buf_thaw(buf); return; } kmutex_t *hash_lock = HDR_LOCK(hdr); mutex_enter(hash_lock); /* * This assignment is only valid as long as the hash_lock is * held, we must be careful not to reference state or the * b_state field after dropping the lock. */ arc_state_t *state = hdr->b_l1hdr.b_state; ASSERT3P(hash_lock, ==, HDR_LOCK(hdr)); ASSERT3P(state, !=, arc_anon); /* this buffer is not on any list */ ASSERT3S(zfs_refcount_count(&hdr->b_l1hdr.b_refcnt), >, 0); if (HDR_HAS_L2HDR(hdr)) { mutex_enter(&hdr->b_l2hdr.b_dev->l2ad_mtx); /* * We have to recheck this conditional again now that * we're holding the l2ad_mtx to prevent a race with * another thread which might be concurrently calling * l2arc_evict(). In that case, l2arc_evict() might have * destroyed the header's L2 portion as we were waiting * to acquire the l2ad_mtx. */ if (HDR_HAS_L2HDR(hdr)) arc_hdr_l2hdr_destroy(hdr); mutex_exit(&hdr->b_l2hdr.b_dev->l2ad_mtx); } /* * Do we have more than one buf? */ if (hdr->b_l1hdr.b_bufcnt > 1) { arc_buf_hdr_t *nhdr; uint64_t spa = hdr->b_spa; uint64_t psize = HDR_GET_PSIZE(hdr); uint64_t lsize = HDR_GET_LSIZE(hdr); boolean_t protected = HDR_PROTECTED(hdr); enum zio_compress compress = arc_hdr_get_compress(hdr); arc_buf_contents_t type = arc_buf_type(hdr); VERIFY3U(hdr->b_type, ==, type); ASSERT(hdr->b_l1hdr.b_buf != buf || buf->b_next != NULL); (void) remove_reference(hdr, hash_lock, tag); if (arc_buf_is_shared(buf) && !ARC_BUF_COMPRESSED(buf)) { ASSERT3P(hdr->b_l1hdr.b_buf, !=, buf); ASSERT(ARC_BUF_LAST(buf)); } /* * Pull the data off of this hdr and attach it to * a new anonymous hdr. Also find the last buffer * in the hdr's buffer list. */ arc_buf_t *lastbuf = arc_buf_remove(hdr, buf); ASSERT3P(lastbuf, !=, NULL); /* * If the current arc_buf_t and the hdr are sharing their data * buffer, then we must stop sharing that block. */ if (arc_buf_is_shared(buf)) { ASSERT3P(hdr->b_l1hdr.b_buf, !=, buf); VERIFY(!arc_buf_is_shared(lastbuf)); /* * First, sever the block sharing relationship between * buf and the arc_buf_hdr_t. */ arc_unshare_buf(hdr, buf); /* * Now we need to recreate the hdr's b_pabd. Since we * have lastbuf handy, we try to share with it, but if * we can't then we allocate a new b_pabd and copy the * data from buf into it. */ if (arc_can_share(hdr, lastbuf)) { arc_share_buf(hdr, lastbuf); } else { arc_hdr_alloc_abd(hdr, ARC_HDR_DO_ADAPT); abd_copy_from_buf(hdr->b_l1hdr.b_pabd, buf->b_data, psize); } VERIFY3P(lastbuf->b_data, !=, NULL); } else if (HDR_SHARED_DATA(hdr)) { /* * Uncompressed shared buffers are always at the end * of the list. Compressed buffers don't have the * same requirements. This makes it hard to * simply assert that the lastbuf is shared so * we rely on the hdr's compression flags to determine * if we have a compressed, shared buffer. */ ASSERT(arc_buf_is_shared(lastbuf) || arc_hdr_get_compress(hdr) != ZIO_COMPRESS_OFF); ASSERT(!ARC_BUF_SHARED(buf)); } ASSERT(hdr->b_l1hdr.b_pabd != NULL || HDR_HAS_RABD(hdr)); ASSERT3P(state, !=, arc_l2c_only); (void) zfs_refcount_remove_many(&state->arcs_size, arc_buf_size(buf), buf); if (zfs_refcount_is_zero(&hdr->b_l1hdr.b_refcnt)) { ASSERT3P(state, !=, arc_l2c_only); (void) zfs_refcount_remove_many( &state->arcs_esize[type], arc_buf_size(buf), buf); } hdr->b_l1hdr.b_bufcnt -= 1; if (ARC_BUF_ENCRYPTED(buf)) hdr->b_crypt_hdr.b_ebufcnt -= 1; arc_cksum_verify(buf); arc_buf_unwatch(buf); /* if this is the last uncompressed buf free the checksum */ if (!arc_hdr_has_uncompressed_buf(hdr)) arc_cksum_free(hdr); mutex_exit(hash_lock); /* * Allocate a new hdr. The new hdr will contain a b_pabd * buffer which will be freed in arc_write(). */ nhdr = arc_hdr_alloc(spa, psize, lsize, protected, compress, hdr->b_complevel, type, HDR_HAS_RABD(hdr)); ASSERT3P(nhdr->b_l1hdr.b_buf, ==, NULL); ASSERT0(nhdr->b_l1hdr.b_bufcnt); ASSERT0(zfs_refcount_count(&nhdr->b_l1hdr.b_refcnt)); VERIFY3U(nhdr->b_type, ==, type); ASSERT(!HDR_SHARED_DATA(nhdr)); nhdr->b_l1hdr.b_buf = buf; nhdr->b_l1hdr.b_bufcnt = 1; if (ARC_BUF_ENCRYPTED(buf)) nhdr->b_crypt_hdr.b_ebufcnt = 1; nhdr->b_l1hdr.b_mru_hits = 0; nhdr->b_l1hdr.b_mru_ghost_hits = 0; nhdr->b_l1hdr.b_mfu_hits = 0; nhdr->b_l1hdr.b_mfu_ghost_hits = 0; nhdr->b_l1hdr.b_l2_hits = 0; (void) zfs_refcount_add(&nhdr->b_l1hdr.b_refcnt, tag); buf->b_hdr = nhdr; mutex_exit(&buf->b_evict_lock); (void) zfs_refcount_add_many(&arc_anon->arcs_size, arc_buf_size(buf), buf); } else { mutex_exit(&buf->b_evict_lock); ASSERT(zfs_refcount_count(&hdr->b_l1hdr.b_refcnt) == 1); /* protected by hash lock, or hdr is on arc_anon */ ASSERT(!multilist_link_active(&hdr->b_l1hdr.b_arc_node)); ASSERT(!HDR_IO_IN_PROGRESS(hdr)); hdr->b_l1hdr.b_mru_hits = 0; hdr->b_l1hdr.b_mru_ghost_hits = 0; hdr->b_l1hdr.b_mfu_hits = 0; hdr->b_l1hdr.b_mfu_ghost_hits = 0; hdr->b_l1hdr.b_l2_hits = 0; arc_change_state(arc_anon, hdr, hash_lock); hdr->b_l1hdr.b_arc_access = 0; mutex_exit(hash_lock); buf_discard_identity(hdr); arc_buf_thaw(buf); } } int arc_released(arc_buf_t *buf) { int released; mutex_enter(&buf->b_evict_lock); released = (buf->b_data != NULL && buf->b_hdr->b_l1hdr.b_state == arc_anon); mutex_exit(&buf->b_evict_lock); return (released); } #ifdef ZFS_DEBUG int arc_referenced(arc_buf_t *buf) { int referenced; mutex_enter(&buf->b_evict_lock); referenced = (zfs_refcount_count(&buf->b_hdr->b_l1hdr.b_refcnt)); mutex_exit(&buf->b_evict_lock); return (referenced); } #endif static void arc_write_ready(zio_t *zio) { arc_write_callback_t *callback = zio->io_private; arc_buf_t *buf = callback->awcb_buf; arc_buf_hdr_t *hdr = buf->b_hdr; blkptr_t *bp = zio->io_bp; uint64_t psize = BP_IS_HOLE(bp) ? 0 : BP_GET_PSIZE(bp); fstrans_cookie_t cookie = spl_fstrans_mark(); ASSERT(HDR_HAS_L1HDR(hdr)); ASSERT(!zfs_refcount_is_zero(&buf->b_hdr->b_l1hdr.b_refcnt)); ASSERT(hdr->b_l1hdr.b_bufcnt > 0); /* * If we're reexecuting this zio because the pool suspended, then * cleanup any state that was previously set the first time the * callback was invoked. */ if (zio->io_flags & ZIO_FLAG_REEXECUTED) { arc_cksum_free(hdr); arc_buf_unwatch(buf); if (hdr->b_l1hdr.b_pabd != NULL) { if (arc_buf_is_shared(buf)) { arc_unshare_buf(hdr, buf); } else { arc_hdr_free_abd(hdr, B_FALSE); } } if (HDR_HAS_RABD(hdr)) arc_hdr_free_abd(hdr, B_TRUE); } ASSERT3P(hdr->b_l1hdr.b_pabd, ==, NULL); ASSERT(!HDR_HAS_RABD(hdr)); ASSERT(!HDR_SHARED_DATA(hdr)); ASSERT(!arc_buf_is_shared(buf)); callback->awcb_ready(zio, buf, callback->awcb_private); if (HDR_IO_IN_PROGRESS(hdr)) ASSERT(zio->io_flags & ZIO_FLAG_REEXECUTED); arc_hdr_set_flags(hdr, ARC_FLAG_IO_IN_PROGRESS); if (BP_IS_PROTECTED(bp) != !!HDR_PROTECTED(hdr)) hdr = arc_hdr_realloc_crypt(hdr, BP_IS_PROTECTED(bp)); if (BP_IS_PROTECTED(bp)) { /* ZIL blocks are written through zio_rewrite */ ASSERT3U(BP_GET_TYPE(bp), !=, DMU_OT_INTENT_LOG); ASSERT(HDR_PROTECTED(hdr)); if (BP_SHOULD_BYTESWAP(bp)) { if (BP_GET_LEVEL(bp) > 0) { hdr->b_l1hdr.b_byteswap = DMU_BSWAP_UINT64; } else { hdr->b_l1hdr.b_byteswap = DMU_OT_BYTESWAP(BP_GET_TYPE(bp)); } } else { hdr->b_l1hdr.b_byteswap = DMU_BSWAP_NUMFUNCS; } hdr->b_crypt_hdr.b_ot = BP_GET_TYPE(bp); hdr->b_crypt_hdr.b_dsobj = zio->io_bookmark.zb_objset; zio_crypt_decode_params_bp(bp, hdr->b_crypt_hdr.b_salt, hdr->b_crypt_hdr.b_iv); zio_crypt_decode_mac_bp(bp, hdr->b_crypt_hdr.b_mac); } /* * If this block was written for raw encryption but the zio layer * ended up only authenticating it, adjust the buffer flags now. */ if (BP_IS_AUTHENTICATED(bp) && ARC_BUF_ENCRYPTED(buf)) { arc_hdr_set_flags(hdr, ARC_FLAG_NOAUTH); buf->b_flags &= ~ARC_BUF_FLAG_ENCRYPTED; if (BP_GET_COMPRESS(bp) == ZIO_COMPRESS_OFF) buf->b_flags &= ~ARC_BUF_FLAG_COMPRESSED; } else if (BP_IS_HOLE(bp) && ARC_BUF_ENCRYPTED(buf)) { buf->b_flags &= ~ARC_BUF_FLAG_ENCRYPTED; buf->b_flags &= ~ARC_BUF_FLAG_COMPRESSED; } /* this must be done after the buffer flags are adjusted */ arc_cksum_compute(buf); enum zio_compress compress; if (BP_IS_HOLE(bp) || BP_IS_EMBEDDED(bp)) { compress = ZIO_COMPRESS_OFF; } else { ASSERT3U(HDR_GET_LSIZE(hdr), ==, BP_GET_LSIZE(bp)); compress = BP_GET_COMPRESS(bp); } HDR_SET_PSIZE(hdr, psize); arc_hdr_set_compress(hdr, compress); hdr->b_complevel = zio->io_prop.zp_complevel; if (zio->io_error != 0 || psize == 0) goto out; /* * Fill the hdr with data. If the buffer is encrypted we have no choice * but to copy the data into b_radb. If the hdr is compressed, the data * we want is available from the zio, otherwise we can take it from * the buf. * * We might be able to share the buf's data with the hdr here. However, * doing so would cause the ARC to be full of linear ABDs if we write a * lot of shareable data. As a compromise, we check whether scattered * ABDs are allowed, and assume that if they are then the user wants * the ARC to be primarily filled with them regardless of the data being * written. Therefore, if they're allowed then we allocate one and copy * the data into it; otherwise, we share the data directly if we can. */ if (ARC_BUF_ENCRYPTED(buf)) { ASSERT3U(psize, >, 0); ASSERT(ARC_BUF_COMPRESSED(buf)); arc_hdr_alloc_abd(hdr, ARC_HDR_DO_ADAPT|ARC_HDR_ALLOC_RDATA); abd_copy(hdr->b_crypt_hdr.b_rabd, zio->io_abd, psize); } else if (zfs_abd_scatter_enabled || !arc_can_share(hdr, buf)) { /* * Ideally, we would always copy the io_abd into b_pabd, but the * user may have disabled compressed ARC, thus we must check the * hdr's compression setting rather than the io_bp's. */ if (BP_IS_ENCRYPTED(bp)) { ASSERT3U(psize, >, 0); arc_hdr_alloc_abd(hdr, ARC_HDR_DO_ADAPT|ARC_HDR_ALLOC_RDATA); abd_copy(hdr->b_crypt_hdr.b_rabd, zio->io_abd, psize); } else if (arc_hdr_get_compress(hdr) != ZIO_COMPRESS_OFF && !ARC_BUF_COMPRESSED(buf)) { ASSERT3U(psize, >, 0); arc_hdr_alloc_abd(hdr, ARC_HDR_DO_ADAPT); abd_copy(hdr->b_l1hdr.b_pabd, zio->io_abd, psize); } else { ASSERT3U(zio->io_orig_size, ==, arc_hdr_size(hdr)); arc_hdr_alloc_abd(hdr, ARC_HDR_DO_ADAPT); abd_copy_from_buf(hdr->b_l1hdr.b_pabd, buf->b_data, arc_buf_size(buf)); } } else { ASSERT3P(buf->b_data, ==, abd_to_buf(zio->io_orig_abd)); ASSERT3U(zio->io_orig_size, ==, arc_buf_size(buf)); ASSERT3U(hdr->b_l1hdr.b_bufcnt, ==, 1); arc_share_buf(hdr, buf); } out: arc_hdr_verify(hdr, bp); spl_fstrans_unmark(cookie); } static void arc_write_children_ready(zio_t *zio) { arc_write_callback_t *callback = zio->io_private; arc_buf_t *buf = callback->awcb_buf; callback->awcb_children_ready(zio, buf, callback->awcb_private); } /* * The SPA calls this callback for each physical write that happens on behalf * of a logical write. See the comment in dbuf_write_physdone() for details. */ static void arc_write_physdone(zio_t *zio) { arc_write_callback_t *cb = zio->io_private; if (cb->awcb_physdone != NULL) cb->awcb_physdone(zio, cb->awcb_buf, cb->awcb_private); } static void arc_write_done(zio_t *zio) { arc_write_callback_t *callback = zio->io_private; arc_buf_t *buf = callback->awcb_buf; arc_buf_hdr_t *hdr = buf->b_hdr; ASSERT3P(hdr->b_l1hdr.b_acb, ==, NULL); if (zio->io_error == 0) { arc_hdr_verify(hdr, zio->io_bp); if (BP_IS_HOLE(zio->io_bp) || BP_IS_EMBEDDED(zio->io_bp)) { buf_discard_identity(hdr); } else { hdr->b_dva = *BP_IDENTITY(zio->io_bp); hdr->b_birth = BP_PHYSICAL_BIRTH(zio->io_bp); } } else { ASSERT(HDR_EMPTY(hdr)); } /* * If the block to be written was all-zero or compressed enough to be * embedded in the BP, no write was performed so there will be no * dva/birth/checksum. The buffer must therefore remain anonymous * (and uncached). */ if (!HDR_EMPTY(hdr)) { arc_buf_hdr_t *exists; kmutex_t *hash_lock; ASSERT3U(zio->io_error, ==, 0); arc_cksum_verify(buf); exists = buf_hash_insert(hdr, &hash_lock); if (exists != NULL) { /* * This can only happen if we overwrite for * sync-to-convergence, because we remove * buffers from the hash table when we arc_free(). */ if (zio->io_flags & ZIO_FLAG_IO_REWRITE) { if (!BP_EQUAL(&zio->io_bp_orig, zio->io_bp)) panic("bad overwrite, hdr=%p exists=%p", (void *)hdr, (void *)exists); ASSERT(zfs_refcount_is_zero( &exists->b_l1hdr.b_refcnt)); arc_change_state(arc_anon, exists, hash_lock); arc_hdr_destroy(exists); mutex_exit(hash_lock); exists = buf_hash_insert(hdr, &hash_lock); ASSERT3P(exists, ==, NULL); } else if (zio->io_flags & ZIO_FLAG_NOPWRITE) { /* nopwrite */ ASSERT(zio->io_prop.zp_nopwrite); if (!BP_EQUAL(&zio->io_bp_orig, zio->io_bp)) panic("bad nopwrite, hdr=%p exists=%p", (void *)hdr, (void *)exists); } else { /* Dedup */ ASSERT(hdr->b_l1hdr.b_bufcnt == 1); ASSERT(hdr->b_l1hdr.b_state == arc_anon); ASSERT(BP_GET_DEDUP(zio->io_bp)); ASSERT(BP_GET_LEVEL(zio->io_bp) == 0); } } arc_hdr_clear_flags(hdr, ARC_FLAG_IO_IN_PROGRESS); /* if it's not anon, we are doing a scrub */ if (exists == NULL && hdr->b_l1hdr.b_state == arc_anon) arc_access(hdr, hash_lock); mutex_exit(hash_lock); } else { arc_hdr_clear_flags(hdr, ARC_FLAG_IO_IN_PROGRESS); } ASSERT(!zfs_refcount_is_zero(&hdr->b_l1hdr.b_refcnt)); callback->awcb_done(zio, buf, callback->awcb_private); - abd_put(zio->io_abd); + abd_free(zio->io_abd); kmem_free(callback, sizeof (arc_write_callback_t)); } zio_t * arc_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, arc_buf_t *buf, boolean_t l2arc, const zio_prop_t *zp, arc_write_done_func_t *ready, arc_write_done_func_t *children_ready, arc_write_done_func_t *physdone, arc_write_done_func_t *done, void *private, zio_priority_t priority, int zio_flags, const zbookmark_phys_t *zb) { arc_buf_hdr_t *hdr = buf->b_hdr; arc_write_callback_t *callback; zio_t *zio; zio_prop_t localprop = *zp; ASSERT3P(ready, !=, NULL); ASSERT3P(done, !=, NULL); ASSERT(!HDR_IO_ERROR(hdr)); ASSERT(!HDR_IO_IN_PROGRESS(hdr)); ASSERT3P(hdr->b_l1hdr.b_acb, ==, NULL); ASSERT3U(hdr->b_l1hdr.b_bufcnt, >, 0); if (l2arc) arc_hdr_set_flags(hdr, ARC_FLAG_L2CACHE); if (ARC_BUF_ENCRYPTED(buf)) { ASSERT(ARC_BUF_COMPRESSED(buf)); localprop.zp_encrypt = B_TRUE; localprop.zp_compress = HDR_GET_COMPRESS(hdr); localprop.zp_complevel = hdr->b_complevel; localprop.zp_byteorder = (hdr->b_l1hdr.b_byteswap == DMU_BSWAP_NUMFUNCS) ? ZFS_HOST_BYTEORDER : !ZFS_HOST_BYTEORDER; bcopy(hdr->b_crypt_hdr.b_salt, localprop.zp_salt, ZIO_DATA_SALT_LEN); bcopy(hdr->b_crypt_hdr.b_iv, localprop.zp_iv, ZIO_DATA_IV_LEN); bcopy(hdr->b_crypt_hdr.b_mac, localprop.zp_mac, ZIO_DATA_MAC_LEN); if (DMU_OT_IS_ENCRYPTED(localprop.zp_type)) { localprop.zp_nopwrite = B_FALSE; localprop.zp_copies = MIN(localprop.zp_copies, SPA_DVAS_PER_BP - 1); } zio_flags |= ZIO_FLAG_RAW; } else if (ARC_BUF_COMPRESSED(buf)) { ASSERT3U(HDR_GET_LSIZE(hdr), !=, arc_buf_size(buf)); localprop.zp_compress = HDR_GET_COMPRESS(hdr); localprop.zp_complevel = hdr->b_complevel; zio_flags |= ZIO_FLAG_RAW_COMPRESS; } callback = kmem_zalloc(sizeof (arc_write_callback_t), KM_SLEEP); callback->awcb_ready = ready; callback->awcb_children_ready = children_ready; callback->awcb_physdone = physdone; callback->awcb_done = done; callback->awcb_private = private; callback->awcb_buf = buf; /* * The hdr's b_pabd is now stale, free it now. A new data block * will be allocated when the zio pipeline calls arc_write_ready(). */ if (hdr->b_l1hdr.b_pabd != NULL) { /* * If the buf is currently sharing the data block with * the hdr then we need to break that relationship here. * The hdr will remain with a NULL data pointer and the * buf will take sole ownership of the block. */ if (arc_buf_is_shared(buf)) { arc_unshare_buf(hdr, buf); } else { arc_hdr_free_abd(hdr, B_FALSE); } VERIFY3P(buf->b_data, !=, NULL); } if (HDR_HAS_RABD(hdr)) arc_hdr_free_abd(hdr, B_TRUE); if (!(zio_flags & ZIO_FLAG_RAW)) arc_hdr_set_compress(hdr, ZIO_COMPRESS_OFF); ASSERT(!arc_buf_is_shared(buf)); ASSERT3P(hdr->b_l1hdr.b_pabd, ==, NULL); zio = zio_write(pio, spa, txg, bp, abd_get_from_buf(buf->b_data, HDR_GET_LSIZE(hdr)), HDR_GET_LSIZE(hdr), arc_buf_size(buf), &localprop, arc_write_ready, (children_ready != NULL) ? arc_write_children_ready : NULL, arc_write_physdone, arc_write_done, callback, priority, zio_flags, zb); return (zio); } void arc_tempreserve_clear(uint64_t reserve) { atomic_add_64(&arc_tempreserve, -reserve); ASSERT((int64_t)arc_tempreserve >= 0); } int arc_tempreserve_space(spa_t *spa, uint64_t reserve, uint64_t txg) { int error; uint64_t anon_size; if (!arc_no_grow && reserve > arc_c/4 && reserve * 4 > (2ULL << SPA_MAXBLOCKSHIFT)) arc_c = MIN(arc_c_max, reserve * 4); /* * Throttle when the calculated memory footprint for the TXG * exceeds the target ARC size. */ if (reserve > arc_c) { DMU_TX_STAT_BUMP(dmu_tx_memory_reserve); return (SET_ERROR(ERESTART)); } /* * Don't count loaned bufs as in flight dirty data to prevent long * network delays from blocking transactions that are ready to be * assigned to a txg. */ /* assert that it has not wrapped around */ ASSERT3S(atomic_add_64_nv(&arc_loaned_bytes, 0), >=, 0); anon_size = MAX((int64_t)(zfs_refcount_count(&arc_anon->arcs_size) - arc_loaned_bytes), 0); /* * Writes will, almost always, require additional memory allocations * in order to compress/encrypt/etc the data. We therefore need to * make sure that there is sufficient available memory for this. */ error = arc_memory_throttle(spa, reserve, txg); if (error != 0) return (error); /* * Throttle writes when the amount of dirty data in the cache * gets too large. We try to keep the cache less than half full * of dirty blocks so that our sync times don't grow too large. * * In the case of one pool being built on another pool, we want * to make sure we don't end up throttling the lower (backing) * pool when the upper pool is the majority contributor to dirty * data. To insure we make forward progress during throttling, we * also check the current pool's net dirty data and only throttle * if it exceeds zfs_arc_pool_dirty_percent of the anonymous dirty * data in the cache. * * Note: if two requests come in concurrently, we might let them * both succeed, when one of them should fail. Not a huge deal. */ uint64_t total_dirty = reserve + arc_tempreserve + anon_size; uint64_t spa_dirty_anon = spa_dirty_data(spa); uint64_t rarc_c = arc_warm ? arc_c : arc_c_max; if (total_dirty > rarc_c * zfs_arc_dirty_limit_percent / 100 && anon_size > rarc_c * zfs_arc_anon_limit_percent / 100 && spa_dirty_anon > anon_size * zfs_arc_pool_dirty_percent / 100) { #ifdef ZFS_DEBUG uint64_t meta_esize = zfs_refcount_count( &arc_anon->arcs_esize[ARC_BUFC_METADATA]); uint64_t data_esize = zfs_refcount_count(&arc_anon->arcs_esize[ARC_BUFC_DATA]); dprintf("failing, arc_tempreserve=%lluK anon_meta=%lluK " "anon_data=%lluK tempreserve=%lluK rarc_c=%lluK\n", arc_tempreserve >> 10, meta_esize >> 10, data_esize >> 10, reserve >> 10, rarc_c >> 10); #endif DMU_TX_STAT_BUMP(dmu_tx_dirty_throttle); return (SET_ERROR(ERESTART)); } atomic_add_64(&arc_tempreserve, reserve); return (0); } static void arc_kstat_update_state(arc_state_t *state, kstat_named_t *size, kstat_named_t *evict_data, kstat_named_t *evict_metadata) { size->value.ui64 = zfs_refcount_count(&state->arcs_size); evict_data->value.ui64 = zfs_refcount_count(&state->arcs_esize[ARC_BUFC_DATA]); evict_metadata->value.ui64 = zfs_refcount_count(&state->arcs_esize[ARC_BUFC_METADATA]); } static int arc_kstat_update(kstat_t *ksp, int rw) { arc_stats_t *as = ksp->ks_data; if (rw == KSTAT_WRITE) { return (SET_ERROR(EACCES)); } else { arc_kstat_update_state(arc_anon, &as->arcstat_anon_size, &as->arcstat_anon_evictable_data, &as->arcstat_anon_evictable_metadata); arc_kstat_update_state(arc_mru, &as->arcstat_mru_size, &as->arcstat_mru_evictable_data, &as->arcstat_mru_evictable_metadata); arc_kstat_update_state(arc_mru_ghost, &as->arcstat_mru_ghost_size, &as->arcstat_mru_ghost_evictable_data, &as->arcstat_mru_ghost_evictable_metadata); arc_kstat_update_state(arc_mfu, &as->arcstat_mfu_size, &as->arcstat_mfu_evictable_data, &as->arcstat_mfu_evictable_metadata); arc_kstat_update_state(arc_mfu_ghost, &as->arcstat_mfu_ghost_size, &as->arcstat_mfu_ghost_evictable_data, &as->arcstat_mfu_ghost_evictable_metadata); ARCSTAT(arcstat_size) = aggsum_value(&arc_size); ARCSTAT(arcstat_meta_used) = aggsum_value(&arc_meta_used); ARCSTAT(arcstat_data_size) = aggsum_value(&astat_data_size); ARCSTAT(arcstat_metadata_size) = aggsum_value(&astat_metadata_size); ARCSTAT(arcstat_hdr_size) = aggsum_value(&astat_hdr_size); ARCSTAT(arcstat_l2_hdr_size) = aggsum_value(&astat_l2_hdr_size); ARCSTAT(arcstat_dbuf_size) = aggsum_value(&astat_dbuf_size); #if defined(COMPAT_FREEBSD11) ARCSTAT(arcstat_other_size) = aggsum_value(&astat_bonus_size) + aggsum_value(&astat_dnode_size) + aggsum_value(&astat_dbuf_size); #endif ARCSTAT(arcstat_dnode_size) = aggsum_value(&astat_dnode_size); ARCSTAT(arcstat_bonus_size) = aggsum_value(&astat_bonus_size); ARCSTAT(arcstat_abd_chunk_waste_size) = aggsum_value(&astat_abd_chunk_waste_size); as->arcstat_memory_all_bytes.value.ui64 = arc_all_memory(); as->arcstat_memory_free_bytes.value.ui64 = arc_free_memory(); as->arcstat_memory_available_bytes.value.i64 = arc_available_memory(); } return (0); } /* * This function *must* return indices evenly distributed between all * sublists of the multilist. This is needed due to how the ARC eviction * code is laid out; arc_evict_state() assumes ARC buffers are evenly * distributed between all sublists and uses this assumption when * deciding which sublist to evict from and how much to evict from it. */ static unsigned int arc_state_multilist_index_func(multilist_t *ml, void *obj) { arc_buf_hdr_t *hdr = obj; /* * We rely on b_dva to generate evenly distributed index * numbers using buf_hash below. So, as an added precaution, * let's make sure we never add empty buffers to the arc lists. */ ASSERT(!HDR_EMPTY(hdr)); /* * The assumption here, is the hash value for a given * arc_buf_hdr_t will remain constant throughout its lifetime * (i.e. its b_spa, b_dva, and b_birth fields don't change). * Thus, we don't need to store the header's sublist index * on insertion, as this index can be recalculated on removal. * * Also, the low order bits of the hash value are thought to be * distributed evenly. Otherwise, in the case that the multilist * has a power of two number of sublists, each sublists' usage * would not be evenly distributed. */ return (buf_hash(hdr->b_spa, &hdr->b_dva, hdr->b_birth) % multilist_get_num_sublists(ml)); } #define WARN_IF_TUNING_IGNORED(tuning, value, do_warn) do { \ if ((do_warn) && (tuning) && ((tuning) != (value))) { \ cmn_err(CE_WARN, \ "ignoring tunable %s (using %llu instead)", \ (#tuning), (value)); \ } \ } while (0) /* * Called during module initialization and periodically thereafter to * apply reasonable changes to the exposed performance tunings. Can also be * called explicitly by param_set_arc_*() functions when ARC tunables are * updated manually. Non-zero zfs_* values which differ from the currently set * values will be applied. */ void arc_tuning_update(boolean_t verbose) { uint64_t allmem = arc_all_memory(); unsigned long limit; /* Valid range: 32M - */ if ((zfs_arc_min) && (zfs_arc_min != arc_c_min) && (zfs_arc_min >= 2ULL << SPA_MAXBLOCKSHIFT) && (zfs_arc_min <= arc_c_max)) { arc_c_min = zfs_arc_min; arc_c = MAX(arc_c, arc_c_min); } WARN_IF_TUNING_IGNORED(zfs_arc_min, arc_c_min, verbose); /* Valid range: 64M - */ if ((zfs_arc_max) && (zfs_arc_max != arc_c_max) && (zfs_arc_max >= 64 << 20) && (zfs_arc_max < allmem) && (zfs_arc_max > arc_c_min)) { arc_c_max = zfs_arc_max; arc_c = MIN(arc_c, arc_c_max); arc_p = (arc_c >> 1); if (arc_meta_limit > arc_c_max) arc_meta_limit = arc_c_max; if (arc_dnode_size_limit > arc_meta_limit) arc_dnode_size_limit = arc_meta_limit; } WARN_IF_TUNING_IGNORED(zfs_arc_max, arc_c_max, verbose); /* Valid range: 16M - */ if ((zfs_arc_meta_min) && (zfs_arc_meta_min != arc_meta_min) && (zfs_arc_meta_min >= 1ULL << SPA_MAXBLOCKSHIFT) && (zfs_arc_meta_min <= arc_c_max)) { arc_meta_min = zfs_arc_meta_min; if (arc_meta_limit < arc_meta_min) arc_meta_limit = arc_meta_min; if (arc_dnode_size_limit < arc_meta_min) arc_dnode_size_limit = arc_meta_min; } WARN_IF_TUNING_IGNORED(zfs_arc_meta_min, arc_meta_min, verbose); /* Valid range: - */ limit = zfs_arc_meta_limit ? zfs_arc_meta_limit : MIN(zfs_arc_meta_limit_percent, 100) * arc_c_max / 100; if ((limit != arc_meta_limit) && (limit >= arc_meta_min) && (limit <= arc_c_max)) arc_meta_limit = limit; WARN_IF_TUNING_IGNORED(zfs_arc_meta_limit, arc_meta_limit, verbose); /* Valid range: - */ limit = zfs_arc_dnode_limit ? zfs_arc_dnode_limit : MIN(zfs_arc_dnode_limit_percent, 100) * arc_meta_limit / 100; if ((limit != arc_dnode_size_limit) && (limit >= arc_meta_min) && (limit <= arc_meta_limit)) arc_dnode_size_limit = limit; WARN_IF_TUNING_IGNORED(zfs_arc_dnode_limit, arc_dnode_size_limit, verbose); /* Valid range: 1 - N */ if (zfs_arc_grow_retry) arc_grow_retry = zfs_arc_grow_retry; /* Valid range: 1 - N */ if (zfs_arc_shrink_shift) { arc_shrink_shift = zfs_arc_shrink_shift; arc_no_grow_shift = MIN(arc_no_grow_shift, arc_shrink_shift -1); } /* Valid range: 1 - N */ if (zfs_arc_p_min_shift) arc_p_min_shift = zfs_arc_p_min_shift; /* Valid range: 1 - N ms */ if (zfs_arc_min_prefetch_ms) arc_min_prefetch_ms = zfs_arc_min_prefetch_ms; /* Valid range: 1 - N ms */ if (zfs_arc_min_prescient_prefetch_ms) { arc_min_prescient_prefetch_ms = zfs_arc_min_prescient_prefetch_ms; } /* Valid range: 0 - 100 */ if ((zfs_arc_lotsfree_percent >= 0) && (zfs_arc_lotsfree_percent <= 100)) arc_lotsfree_percent = zfs_arc_lotsfree_percent; WARN_IF_TUNING_IGNORED(zfs_arc_lotsfree_percent, arc_lotsfree_percent, verbose); /* Valid range: 0 - */ if ((zfs_arc_sys_free) && (zfs_arc_sys_free != arc_sys_free)) arc_sys_free = MIN(MAX(zfs_arc_sys_free, 0), allmem); WARN_IF_TUNING_IGNORED(zfs_arc_sys_free, arc_sys_free, verbose); } static void arc_state_init(void) { arc_anon = &ARC_anon; arc_mru = &ARC_mru; arc_mru_ghost = &ARC_mru_ghost; arc_mfu = &ARC_mfu; arc_mfu_ghost = &ARC_mfu_ghost; arc_l2c_only = &ARC_l2c_only; arc_mru->arcs_list[ARC_BUFC_METADATA] = multilist_create(sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node), arc_state_multilist_index_func); arc_mru->arcs_list[ARC_BUFC_DATA] = multilist_create(sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node), arc_state_multilist_index_func); arc_mru_ghost->arcs_list[ARC_BUFC_METADATA] = multilist_create(sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node), arc_state_multilist_index_func); arc_mru_ghost->arcs_list[ARC_BUFC_DATA] = multilist_create(sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node), arc_state_multilist_index_func); arc_mfu->arcs_list[ARC_BUFC_METADATA] = multilist_create(sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node), arc_state_multilist_index_func); arc_mfu->arcs_list[ARC_BUFC_DATA] = multilist_create(sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node), arc_state_multilist_index_func); arc_mfu_ghost->arcs_list[ARC_BUFC_METADATA] = multilist_create(sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node), arc_state_multilist_index_func); arc_mfu_ghost->arcs_list[ARC_BUFC_DATA] = multilist_create(sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node), arc_state_multilist_index_func); arc_l2c_only->arcs_list[ARC_BUFC_METADATA] = multilist_create(sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node), arc_state_multilist_index_func); arc_l2c_only->arcs_list[ARC_BUFC_DATA] = multilist_create(sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node), arc_state_multilist_index_func); zfs_refcount_create(&arc_anon->arcs_esize[ARC_BUFC_METADATA]); zfs_refcount_create(&arc_anon->arcs_esize[ARC_BUFC_DATA]); zfs_refcount_create(&arc_mru->arcs_esize[ARC_BUFC_METADATA]); zfs_refcount_create(&arc_mru->arcs_esize[ARC_BUFC_DATA]); zfs_refcount_create(&arc_mru_ghost->arcs_esize[ARC_BUFC_METADATA]); zfs_refcount_create(&arc_mru_ghost->arcs_esize[ARC_BUFC_DATA]); zfs_refcount_create(&arc_mfu->arcs_esize[ARC_BUFC_METADATA]); zfs_refcount_create(&arc_mfu->arcs_esize[ARC_BUFC_DATA]); zfs_refcount_create(&arc_mfu_ghost->arcs_esize[ARC_BUFC_METADATA]); zfs_refcount_create(&arc_mfu_ghost->arcs_esize[ARC_BUFC_DATA]); zfs_refcount_create(&arc_l2c_only->arcs_esize[ARC_BUFC_METADATA]); zfs_refcount_create(&arc_l2c_only->arcs_esize[ARC_BUFC_DATA]); zfs_refcount_create(&arc_anon->arcs_size); zfs_refcount_create(&arc_mru->arcs_size); zfs_refcount_create(&arc_mru_ghost->arcs_size); zfs_refcount_create(&arc_mfu->arcs_size); zfs_refcount_create(&arc_mfu_ghost->arcs_size); zfs_refcount_create(&arc_l2c_only->arcs_size); aggsum_init(&arc_meta_used, 0); aggsum_init(&arc_size, 0); aggsum_init(&astat_data_size, 0); aggsum_init(&astat_metadata_size, 0); aggsum_init(&astat_hdr_size, 0); aggsum_init(&astat_l2_hdr_size, 0); aggsum_init(&astat_bonus_size, 0); aggsum_init(&astat_dnode_size, 0); aggsum_init(&astat_dbuf_size, 0); aggsum_init(&astat_abd_chunk_waste_size, 0); arc_anon->arcs_state = ARC_STATE_ANON; arc_mru->arcs_state = ARC_STATE_MRU; arc_mru_ghost->arcs_state = ARC_STATE_MRU_GHOST; arc_mfu->arcs_state = ARC_STATE_MFU; arc_mfu_ghost->arcs_state = ARC_STATE_MFU_GHOST; arc_l2c_only->arcs_state = ARC_STATE_L2C_ONLY; } static void arc_state_fini(void) { zfs_refcount_destroy(&arc_anon->arcs_esize[ARC_BUFC_METADATA]); zfs_refcount_destroy(&arc_anon->arcs_esize[ARC_BUFC_DATA]); zfs_refcount_destroy(&arc_mru->arcs_esize[ARC_BUFC_METADATA]); zfs_refcount_destroy(&arc_mru->arcs_esize[ARC_BUFC_DATA]); zfs_refcount_destroy(&arc_mru_ghost->arcs_esize[ARC_BUFC_METADATA]); zfs_refcount_destroy(&arc_mru_ghost->arcs_esize[ARC_BUFC_DATA]); zfs_refcount_destroy(&arc_mfu->arcs_esize[ARC_BUFC_METADATA]); zfs_refcount_destroy(&arc_mfu->arcs_esize[ARC_BUFC_DATA]); zfs_refcount_destroy(&arc_mfu_ghost->arcs_esize[ARC_BUFC_METADATA]); zfs_refcount_destroy(&arc_mfu_ghost->arcs_esize[ARC_BUFC_DATA]); zfs_refcount_destroy(&arc_l2c_only->arcs_esize[ARC_BUFC_METADATA]); zfs_refcount_destroy(&arc_l2c_only->arcs_esize[ARC_BUFC_DATA]); zfs_refcount_destroy(&arc_anon->arcs_size); zfs_refcount_destroy(&arc_mru->arcs_size); zfs_refcount_destroy(&arc_mru_ghost->arcs_size); zfs_refcount_destroy(&arc_mfu->arcs_size); zfs_refcount_destroy(&arc_mfu_ghost->arcs_size); zfs_refcount_destroy(&arc_l2c_only->arcs_size); multilist_destroy(arc_mru->arcs_list[ARC_BUFC_METADATA]); multilist_destroy(arc_mru_ghost->arcs_list[ARC_BUFC_METADATA]); multilist_destroy(arc_mfu->arcs_list[ARC_BUFC_METADATA]); multilist_destroy(arc_mfu_ghost->arcs_list[ARC_BUFC_METADATA]); multilist_destroy(arc_mru->arcs_list[ARC_BUFC_DATA]); multilist_destroy(arc_mru_ghost->arcs_list[ARC_BUFC_DATA]); multilist_destroy(arc_mfu->arcs_list[ARC_BUFC_DATA]); multilist_destroy(arc_mfu_ghost->arcs_list[ARC_BUFC_DATA]); multilist_destroy(arc_l2c_only->arcs_list[ARC_BUFC_METADATA]); multilist_destroy(arc_l2c_only->arcs_list[ARC_BUFC_DATA]); aggsum_fini(&arc_meta_used); aggsum_fini(&arc_size); aggsum_fini(&astat_data_size); aggsum_fini(&astat_metadata_size); aggsum_fini(&astat_hdr_size); aggsum_fini(&astat_l2_hdr_size); aggsum_fini(&astat_bonus_size); aggsum_fini(&astat_dnode_size); aggsum_fini(&astat_dbuf_size); aggsum_fini(&astat_abd_chunk_waste_size); } uint64_t arc_target_bytes(void) { return (arc_c); } void arc_set_limits(uint64_t allmem) { /* Set min cache to 1/32 of all memory, or 32MB, whichever is more. */ arc_c_min = MAX(allmem / 32, 2ULL << SPA_MAXBLOCKSHIFT); /* How to set default max varies by platform. */ arc_c_max = arc_default_max(arc_c_min, allmem); } void arc_init(void) { uint64_t percent, allmem = arc_all_memory(); mutex_init(&arc_evict_lock, NULL, MUTEX_DEFAULT, NULL); list_create(&arc_evict_waiters, sizeof (arc_evict_waiter_t), offsetof(arc_evict_waiter_t, aew_node)); arc_min_prefetch_ms = 1000; arc_min_prescient_prefetch_ms = 6000; #if defined(_KERNEL) arc_lowmem_init(); #endif arc_set_limits(allmem); #ifndef _KERNEL /* * In userland, there's only the memory pressure that we artificially * create (see arc_available_memory()). Don't let arc_c get too * small, because it can cause transactions to be larger than * arc_c, causing arc_tempreserve_space() to fail. */ arc_c_min = MAX(arc_c_max / 2, 2ULL << SPA_MAXBLOCKSHIFT); #endif arc_c = arc_c_min; arc_p = (arc_c >> 1); /* Set min to 1/2 of arc_c_min */ arc_meta_min = 1ULL << SPA_MAXBLOCKSHIFT; /* Initialize maximum observed usage to zero */ arc_meta_max = 0; /* * Set arc_meta_limit to a percent of arc_c_max with a floor of * arc_meta_min, and a ceiling of arc_c_max. */ percent = MIN(zfs_arc_meta_limit_percent, 100); arc_meta_limit = MAX(arc_meta_min, (percent * arc_c_max) / 100); percent = MIN(zfs_arc_dnode_limit_percent, 100); arc_dnode_size_limit = (percent * arc_meta_limit) / 100; /* Apply user specified tunings */ arc_tuning_update(B_TRUE); /* if kmem_flags are set, lets try to use less memory */ if (kmem_debugging()) arc_c = arc_c / 2; if (arc_c < arc_c_min) arc_c = arc_c_min; arc_register_hotplug(); arc_state_init(); buf_init(); list_create(&arc_prune_list, sizeof (arc_prune_t), offsetof(arc_prune_t, p_node)); mutex_init(&arc_prune_mtx, NULL, MUTEX_DEFAULT, NULL); arc_prune_taskq = taskq_create("arc_prune", 100, defclsyspri, boot_ncpus, INT_MAX, TASKQ_PREPOPULATE | TASKQ_DYNAMIC | TASKQ_THREADS_CPU_PCT); arc_ksp = kstat_create("zfs", 0, "arcstats", "misc", KSTAT_TYPE_NAMED, sizeof (arc_stats) / sizeof (kstat_named_t), KSTAT_FLAG_VIRTUAL); if (arc_ksp != NULL) { arc_ksp->ks_data = &arc_stats; arc_ksp->ks_update = arc_kstat_update; kstat_install(arc_ksp); } arc_evict_zthr = zthr_create("arc_evict", arc_evict_cb_check, arc_evict_cb, NULL); arc_reap_zthr = zthr_create_timer("arc_reap", arc_reap_cb_check, arc_reap_cb, NULL, SEC2NSEC(1)); arc_warm = B_FALSE; /* * Calculate maximum amount of dirty data per pool. * * If it has been set by a module parameter, take that. * Otherwise, use a percentage of physical memory defined by * zfs_dirty_data_max_percent (default 10%) with a cap at * zfs_dirty_data_max_max (default 4G or 25% of physical memory). */ #ifdef __LP64__ if (zfs_dirty_data_max_max == 0) zfs_dirty_data_max_max = MIN(4ULL * 1024 * 1024 * 1024, allmem * zfs_dirty_data_max_max_percent / 100); #else if (zfs_dirty_data_max_max == 0) zfs_dirty_data_max_max = MIN(1ULL * 1024 * 1024 * 1024, allmem * zfs_dirty_data_max_max_percent / 100); #endif if (zfs_dirty_data_max == 0) { zfs_dirty_data_max = allmem * zfs_dirty_data_max_percent / 100; zfs_dirty_data_max = MIN(zfs_dirty_data_max, zfs_dirty_data_max_max); } } void arc_fini(void) { arc_prune_t *p; #ifdef _KERNEL arc_lowmem_fini(); #endif /* _KERNEL */ /* Use B_TRUE to ensure *all* buffers are evicted */ arc_flush(NULL, B_TRUE); if (arc_ksp != NULL) { kstat_delete(arc_ksp); arc_ksp = NULL; } taskq_wait(arc_prune_taskq); taskq_destroy(arc_prune_taskq); mutex_enter(&arc_prune_mtx); while ((p = list_head(&arc_prune_list)) != NULL) { list_remove(&arc_prune_list, p); zfs_refcount_remove(&p->p_refcnt, &arc_prune_list); zfs_refcount_destroy(&p->p_refcnt); kmem_free(p, sizeof (*p)); } mutex_exit(&arc_prune_mtx); list_destroy(&arc_prune_list); mutex_destroy(&arc_prune_mtx); (void) zthr_cancel(arc_evict_zthr); (void) zthr_cancel(arc_reap_zthr); mutex_destroy(&arc_evict_lock); list_destroy(&arc_evict_waiters); /* * Free any buffers that were tagged for destruction. This needs * to occur before arc_state_fini() runs and destroys the aggsum * values which are updated when freeing scatter ABDs. */ l2arc_do_free_on_write(); /* * buf_fini() must proceed arc_state_fini() because buf_fin() may * trigger the release of kmem magazines, which can callback to * arc_space_return() which accesses aggsums freed in act_state_fini(). */ buf_fini(); arc_state_fini(); arc_unregister_hotplug(); /* * We destroy the zthrs after all the ARC state has been * torn down to avoid the case of them receiving any * wakeup() signals after they are destroyed. */ zthr_destroy(arc_evict_zthr); zthr_destroy(arc_reap_zthr); ASSERT0(arc_loaned_bytes); } /* * Level 2 ARC * * The level 2 ARC (L2ARC) is a cache layer in-between main memory and disk. * It uses dedicated storage devices to hold cached data, which are populated * using large infrequent writes. The main role of this cache is to boost * the performance of random read workloads. The intended L2ARC devices * include short-stroked disks, solid state disks, and other media with * substantially faster read latency than disk. * * +-----------------------+ * | ARC | * +-----------------------+ * | ^ ^ * | | | * l2arc_feed_thread() arc_read() * | | | * | l2arc read | * V | | * +---------------+ | * | L2ARC | | * +---------------+ | * | ^ | * l2arc_write() | | * | | | * V | | * +-------+ +-------+ * | vdev | | vdev | * | cache | | cache | * +-------+ +-------+ * +=========+ .-----. * : L2ARC : |-_____-| * : devices : | Disks | * +=========+ `-_____-' * * Read requests are satisfied from the following sources, in order: * * 1) ARC * 2) vdev cache of L2ARC devices * 3) L2ARC devices * 4) vdev cache of disks * 5) disks * * Some L2ARC device types exhibit extremely slow write performance. * To accommodate for this there are some significant differences between * the L2ARC and traditional cache design: * * 1. There is no eviction path from the ARC to the L2ARC. Evictions from * the ARC behave as usual, freeing buffers and placing headers on ghost * lists. The ARC does not send buffers to the L2ARC during eviction as * this would add inflated write latencies for all ARC memory pressure. * * 2. The L2ARC attempts to cache data from the ARC before it is evicted. * It does this by periodically scanning buffers from the eviction-end of * the MFU and MRU ARC lists, copying them to the L2ARC devices if they are * not already there. It scans until a headroom of buffers is satisfied, * which itself is a buffer for ARC eviction. If a compressible buffer is * found during scanning and selected for writing to an L2ARC device, we * temporarily boost scanning headroom during the next scan cycle to make * sure we adapt to compression effects (which might significantly reduce * the data volume we write to L2ARC). The thread that does this is * l2arc_feed_thread(), illustrated below; example sizes are included to * provide a better sense of ratio than this diagram: * * head --> tail * +---------------------+----------+ * ARC_mfu |:::::#:::::::::::::::|o#o###o###|-->. # already on L2ARC * +---------------------+----------+ | o L2ARC eligible * ARC_mru |:#:::::::::::::::::::|#o#ooo####|-->| : ARC buffer * +---------------------+----------+ | * 15.9 Gbytes ^ 32 Mbytes | * headroom | * l2arc_feed_thread() * | * l2arc write hand <--[oooo]--' * | 8 Mbyte * | write max * V * +==============================+ * L2ARC dev |####|#|###|###| |####| ... | * +==============================+ * 32 Gbytes * * 3. If an ARC buffer is copied to the L2ARC but then hit instead of * evicted, then the L2ARC has cached a buffer much sooner than it probably * needed to, potentially wasting L2ARC device bandwidth and storage. It is * safe to say that this is an uncommon case, since buffers at the end of * the ARC lists have moved there due to inactivity. * * 4. If the ARC evicts faster than the L2ARC can maintain a headroom, * then the L2ARC simply misses copying some buffers. This serves as a * pressure valve to prevent heavy read workloads from both stalling the ARC * with waits and clogging the L2ARC with writes. This also helps prevent * the potential for the L2ARC to churn if it attempts to cache content too * quickly, such as during backups of the entire pool. * * 5. After system boot and before the ARC has filled main memory, there are * no evictions from the ARC and so the tails of the ARC_mfu and ARC_mru * lists can remain mostly static. Instead of searching from tail of these * lists as pictured, the l2arc_feed_thread() will search from the list heads * for eligible buffers, greatly increasing its chance of finding them. * * The L2ARC device write speed is also boosted during this time so that * the L2ARC warms up faster. Since there have been no ARC evictions yet, * there are no L2ARC reads, and no fear of degrading read performance * through increased writes. * * 6. Writes to the L2ARC devices are grouped and sent in-sequence, so that * the vdev queue can aggregate them into larger and fewer writes. Each * device is written to in a rotor fashion, sweeping writes through * available space then repeating. * * 7. The L2ARC does not store dirty content. It never needs to flush * write buffers back to disk based storage. * * 8. If an ARC buffer is written (and dirtied) which also exists in the * L2ARC, the now stale L2ARC buffer is immediately dropped. * * The performance of the L2ARC can be tweaked by a number of tunables, which * may be necessary for different workloads: * * l2arc_write_max max write bytes per interval * l2arc_write_boost extra write bytes during device warmup * l2arc_noprefetch skip caching prefetched buffers * l2arc_headroom number of max device writes to precache * l2arc_headroom_boost when we find compressed buffers during ARC * scanning, we multiply headroom by this * percentage factor for the next scan cycle, * since more compressed buffers are likely to * be present * l2arc_feed_secs seconds between L2ARC writing * * Tunables may be removed or added as future performance improvements are * integrated, and also may become zpool properties. * * There are three key functions that control how the L2ARC warms up: * * l2arc_write_eligible() check if a buffer is eligible to cache * l2arc_write_size() calculate how much to write * l2arc_write_interval() calculate sleep delay between writes * * These three functions determine what to write, how much, and how quickly * to send writes. * * L2ARC persistence: * * When writing buffers to L2ARC, we periodically add some metadata to * make sure we can pick them up after reboot, thus dramatically reducing * the impact that any downtime has on the performance of storage systems * with large caches. * * The implementation works fairly simply by integrating the following two * modifications: * * *) When writing to the L2ARC, we occasionally write a "l2arc log block", * which is an additional piece of metadata which describes what's been * written. This allows us to rebuild the arc_buf_hdr_t structures of the * main ARC buffers. There are 2 linked-lists of log blocks headed by * dh_start_lbps[2]. We alternate which chain we append to, so they are * time-wise and offset-wise interleaved, but that is an optimization rather * than for correctness. The log block also includes a pointer to the * previous block in its chain. * * *) We reserve SPA_MINBLOCKSIZE of space at the start of each L2ARC device * for our header bookkeeping purposes. This contains a device header, * which contains our top-level reference structures. We update it each * time we write a new log block, so that we're able to locate it in the * L2ARC device. If this write results in an inconsistent device header * (e.g. due to power failure), we detect this by verifying the header's * checksum and simply fail to reconstruct the L2ARC after reboot. * * Implementation diagram: * * +=== L2ARC device (not to scale) ======================================+ * | ___two newest log block pointers__.__________ | * | / \dh_start_lbps[1] | * | / \ \dh_start_lbps[0]| * |.___/__. V V | * ||L2 dev|....|lb |bufs |lb |bufs |lb |bufs |lb |bufs |lb |---(empty)---| * || hdr| ^ /^ /^ / / | * |+------+ ...--\-------/ \-----/--\------/ / | * | \--------------/ \--------------/ | * +======================================================================+ * * As can be seen on the diagram, rather than using a simple linked list, * we use a pair of linked lists with alternating elements. This is a * performance enhancement due to the fact that we only find out the * address of the next log block access once the current block has been * completely read in. Obviously, this hurts performance, because we'd be * keeping the device's I/O queue at only a 1 operation deep, thus * incurring a large amount of I/O round-trip latency. Having two lists * allows us to fetch two log blocks ahead of where we are currently * rebuilding L2ARC buffers. * * On-device data structures: * * L2ARC device header: l2arc_dev_hdr_phys_t * L2ARC log block: l2arc_log_blk_phys_t * * L2ARC reconstruction: * * When writing data, we simply write in the standard rotary fashion, * evicting buffers as we go and simply writing new data over them (writing * a new log block every now and then). This obviously means that once we * loop around the end of the device, we will start cutting into an already * committed log block (and its referenced data buffers), like so: * * current write head__ __old tail * \ / * V V * <--|bufs |lb |bufs |lb | |bufs |lb |bufs |lb |--> * ^ ^^^^^^^^^___________________________________ * | \ * <> may overwrite this blk and/or its bufs --' * * When importing the pool, we detect this situation and use it to stop * our scanning process (see l2arc_rebuild). * * There is one significant caveat to consider when rebuilding ARC contents * from an L2ARC device: what about invalidated buffers? Given the above * construction, we cannot update blocks which we've already written to amend * them to remove buffers which were invalidated. Thus, during reconstruction, * we might be populating the cache with buffers for data that's not on the * main pool anymore, or may have been overwritten! * * As it turns out, this isn't a problem. Every arc_read request includes * both the DVA and, crucially, the birth TXG of the BP the caller is * looking for. So even if the cache were populated by completely rotten * blocks for data that had been long deleted and/or overwritten, we'll * never actually return bad data from the cache, since the DVA with the * birth TXG uniquely identify a block in space and time - once created, * a block is immutable on disk. The worst thing we have done is wasted * some time and memory at l2arc rebuild to reconstruct outdated ARC * entries that will get dropped from the l2arc as it is being updated * with new blocks. * * L2ARC buffers that have been evicted by l2arc_evict() ahead of the write * hand are not restored. This is done by saving the offset (in bytes) * l2arc_evict() has evicted to in the L2ARC device header and taking it * into account when restoring buffers. */ static boolean_t l2arc_write_eligible(uint64_t spa_guid, arc_buf_hdr_t *hdr) { /* * A buffer is *not* eligible for the L2ARC if it: * 1. belongs to a different spa. * 2. is already cached on the L2ARC. * 3. has an I/O in progress (it may be an incomplete read). * 4. is flagged not eligible (zfs property). */ if (hdr->b_spa != spa_guid || HDR_HAS_L2HDR(hdr) || HDR_IO_IN_PROGRESS(hdr) || !HDR_L2CACHE(hdr)) return (B_FALSE); return (B_TRUE); } static uint64_t l2arc_write_size(l2arc_dev_t *dev) { uint64_t size, dev_size, tsize; /* * Make sure our globals have meaningful values in case the user * altered them. */ size = l2arc_write_max; if (size == 0) { cmn_err(CE_NOTE, "Bad value for l2arc_write_max, value must " "be greater than zero, resetting it to the default (%d)", L2ARC_WRITE_SIZE); size = l2arc_write_max = L2ARC_WRITE_SIZE; } if (arc_warm == B_FALSE) size += l2arc_write_boost; /* * Make sure the write size does not exceed the size of the cache * device. This is important in l2arc_evict(), otherwise infinite * iteration can occur. */ dev_size = dev->l2ad_end - dev->l2ad_start; tsize = size + l2arc_log_blk_overhead(size, dev); if (dev->l2ad_vdev->vdev_has_trim && l2arc_trim_ahead > 0) tsize += MAX(64 * 1024 * 1024, (tsize * l2arc_trim_ahead) / 100); if (tsize >= dev_size) { cmn_err(CE_NOTE, "l2arc_write_max or l2arc_write_boost " "plus the overhead of log blocks (persistent L2ARC, " "%llu bytes) exceeds the size of the cache device " "(guid %llu), resetting them to the default (%d)", l2arc_log_blk_overhead(size, dev), dev->l2ad_vdev->vdev_guid, L2ARC_WRITE_SIZE); size = l2arc_write_max = l2arc_write_boost = L2ARC_WRITE_SIZE; if (arc_warm == B_FALSE) size += l2arc_write_boost; } return (size); } static clock_t l2arc_write_interval(clock_t began, uint64_t wanted, uint64_t wrote) { clock_t interval, next, now; /* * If the ARC lists are busy, increase our write rate; if the * lists are stale, idle back. This is achieved by checking * how much we previously wrote - if it was more than half of * what we wanted, schedule the next write much sooner. */ if (l2arc_feed_again && wrote > (wanted / 2)) interval = (hz * l2arc_feed_min_ms) / 1000; else interval = hz * l2arc_feed_secs; now = ddi_get_lbolt(); next = MAX(now, MIN(now + interval, began + interval)); return (next); } /* * Cycle through L2ARC devices. This is how L2ARC load balances. * If a device is returned, this also returns holding the spa config lock. */ static l2arc_dev_t * l2arc_dev_get_next(void) { l2arc_dev_t *first, *next = NULL; /* * Lock out the removal of spas (spa_namespace_lock), then removal * of cache devices (l2arc_dev_mtx). Once a device has been selected, * both locks will be dropped and a spa config lock held instead. */ mutex_enter(&spa_namespace_lock); mutex_enter(&l2arc_dev_mtx); /* if there are no vdevs, there is nothing to do */ if (l2arc_ndev == 0) goto out; first = NULL; next = l2arc_dev_last; do { /* loop around the list looking for a non-faulted vdev */ if (next == NULL) { next = list_head(l2arc_dev_list); } else { next = list_next(l2arc_dev_list, next); if (next == NULL) next = list_head(l2arc_dev_list); } /* if we have come back to the start, bail out */ if (first == NULL) first = next; else if (next == first) break; } while (vdev_is_dead(next->l2ad_vdev) || next->l2ad_rebuild || next->l2ad_trim_all); /* if we were unable to find any usable vdevs, return NULL */ if (vdev_is_dead(next->l2ad_vdev) || next->l2ad_rebuild || next->l2ad_trim_all) next = NULL; l2arc_dev_last = next; out: mutex_exit(&l2arc_dev_mtx); /* * Grab the config lock to prevent the 'next' device from being * removed while we are writing to it. */ if (next != NULL) spa_config_enter(next->l2ad_spa, SCL_L2ARC, next, RW_READER); mutex_exit(&spa_namespace_lock); return (next); } /* * Free buffers that were tagged for destruction. */ static void l2arc_do_free_on_write(void) { list_t *buflist; l2arc_data_free_t *df, *df_prev; mutex_enter(&l2arc_free_on_write_mtx); buflist = l2arc_free_on_write; for (df = list_tail(buflist); df; df = df_prev) { df_prev = list_prev(buflist, df); ASSERT3P(df->l2df_abd, !=, NULL); abd_free(df->l2df_abd); list_remove(buflist, df); kmem_free(df, sizeof (l2arc_data_free_t)); } mutex_exit(&l2arc_free_on_write_mtx); } /* * A write to a cache device has completed. Update all headers to allow * reads from these buffers to begin. */ static void l2arc_write_done(zio_t *zio) { l2arc_write_callback_t *cb; l2arc_lb_abd_buf_t *abd_buf; l2arc_lb_ptr_buf_t *lb_ptr_buf; l2arc_dev_t *dev; l2arc_dev_hdr_phys_t *l2dhdr; list_t *buflist; arc_buf_hdr_t *head, *hdr, *hdr_prev; kmutex_t *hash_lock; int64_t bytes_dropped = 0; cb = zio->io_private; ASSERT3P(cb, !=, NULL); dev = cb->l2wcb_dev; l2dhdr = dev->l2ad_dev_hdr; ASSERT3P(dev, !=, NULL); head = cb->l2wcb_head; ASSERT3P(head, !=, NULL); buflist = &dev->l2ad_buflist; ASSERT3P(buflist, !=, NULL); DTRACE_PROBE2(l2arc__iodone, zio_t *, zio, l2arc_write_callback_t *, cb); /* * All writes completed, or an error was hit. */ top: mutex_enter(&dev->l2ad_mtx); for (hdr = list_prev(buflist, head); hdr; hdr = hdr_prev) { hdr_prev = list_prev(buflist, hdr); hash_lock = HDR_LOCK(hdr); /* * We cannot use mutex_enter or else we can deadlock * with l2arc_write_buffers (due to swapping the order * the hash lock and l2ad_mtx are taken). */ if (!mutex_tryenter(hash_lock)) { /* * Missed the hash lock. We must retry so we * don't leave the ARC_FLAG_L2_WRITING bit set. */ ARCSTAT_BUMP(arcstat_l2_writes_lock_retry); /* * We don't want to rescan the headers we've * already marked as having been written out, so * we reinsert the head node so we can pick up * where we left off. */ list_remove(buflist, head); list_insert_after(buflist, hdr, head); mutex_exit(&dev->l2ad_mtx); /* * We wait for the hash lock to become available * to try and prevent busy waiting, and increase * the chance we'll be able to acquire the lock * the next time around. */ mutex_enter(hash_lock); mutex_exit(hash_lock); goto top; } /* * We could not have been moved into the arc_l2c_only * state while in-flight due to our ARC_FLAG_L2_WRITING * bit being set. Let's just ensure that's being enforced. */ ASSERT(HDR_HAS_L1HDR(hdr)); /* * Skipped - drop L2ARC entry and mark the header as no * longer L2 eligibile. */ if (zio->io_error != 0) { /* * Error - drop L2ARC entry. */ list_remove(buflist, hdr); arc_hdr_clear_flags(hdr, ARC_FLAG_HAS_L2HDR); uint64_t psize = HDR_GET_PSIZE(hdr); l2arc_hdr_arcstats_decrement(hdr); bytes_dropped += vdev_psize_to_asize(dev->l2ad_vdev, psize); (void) zfs_refcount_remove_many(&dev->l2ad_alloc, arc_hdr_size(hdr), hdr); } /* * Allow ARC to begin reads and ghost list evictions to * this L2ARC entry. */ arc_hdr_clear_flags(hdr, ARC_FLAG_L2_WRITING); mutex_exit(hash_lock); } /* * Free the allocated abd buffers for writing the log blocks. * If the zio failed reclaim the allocated space and remove the * pointers to these log blocks from the log block pointer list * of the L2ARC device. */ while ((abd_buf = list_remove_tail(&cb->l2wcb_abd_list)) != NULL) { abd_free(abd_buf->abd); zio_buf_free(abd_buf, sizeof (*abd_buf)); if (zio->io_error != 0) { lb_ptr_buf = list_remove_head(&dev->l2ad_lbptr_list); /* * L2BLK_GET_PSIZE returns aligned size for log * blocks. */ uint64_t asize = L2BLK_GET_PSIZE((lb_ptr_buf->lb_ptr)->lbp_prop); bytes_dropped += asize; ARCSTAT_INCR(arcstat_l2_log_blk_asize, -asize); ARCSTAT_BUMPDOWN(arcstat_l2_log_blk_count); zfs_refcount_remove_many(&dev->l2ad_lb_asize, asize, lb_ptr_buf); zfs_refcount_remove(&dev->l2ad_lb_count, lb_ptr_buf); kmem_free(lb_ptr_buf->lb_ptr, sizeof (l2arc_log_blkptr_t)); kmem_free(lb_ptr_buf, sizeof (l2arc_lb_ptr_buf_t)); } } list_destroy(&cb->l2wcb_abd_list); if (zio->io_error != 0) { ARCSTAT_BUMP(arcstat_l2_writes_error); /* * Restore the lbps array in the header to its previous state. * If the list of log block pointers is empty, zero out the * log block pointers in the device header. */ lb_ptr_buf = list_head(&dev->l2ad_lbptr_list); for (int i = 0; i < 2; i++) { if (lb_ptr_buf == NULL) { /* * If the list is empty zero out the device * header. Otherwise zero out the second log * block pointer in the header. */ if (i == 0) { bzero(l2dhdr, dev->l2ad_dev_hdr_asize); } else { bzero(&l2dhdr->dh_start_lbps[i], sizeof (l2arc_log_blkptr_t)); } break; } bcopy(lb_ptr_buf->lb_ptr, &l2dhdr->dh_start_lbps[i], sizeof (l2arc_log_blkptr_t)); lb_ptr_buf = list_next(&dev->l2ad_lbptr_list, lb_ptr_buf); } } atomic_inc_64(&l2arc_writes_done); list_remove(buflist, head); ASSERT(!HDR_HAS_L1HDR(head)); kmem_cache_free(hdr_l2only_cache, head); mutex_exit(&dev->l2ad_mtx); ASSERT(dev->l2ad_vdev != NULL); vdev_space_update(dev->l2ad_vdev, -bytes_dropped, 0, 0); l2arc_do_free_on_write(); kmem_free(cb, sizeof (l2arc_write_callback_t)); } static int l2arc_untransform(zio_t *zio, l2arc_read_callback_t *cb) { int ret; spa_t *spa = zio->io_spa; arc_buf_hdr_t *hdr = cb->l2rcb_hdr; blkptr_t *bp = zio->io_bp; uint8_t salt[ZIO_DATA_SALT_LEN]; uint8_t iv[ZIO_DATA_IV_LEN]; uint8_t mac[ZIO_DATA_MAC_LEN]; boolean_t no_crypt = B_FALSE; /* * ZIL data is never be written to the L2ARC, so we don't need * special handling for its unique MAC storage. */ ASSERT3U(BP_GET_TYPE(bp), !=, DMU_OT_INTENT_LOG); ASSERT(MUTEX_HELD(HDR_LOCK(hdr))); ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL); /* * If the data was encrypted, decrypt it now. Note that * we must check the bp here and not the hdr, since the * hdr does not have its encryption parameters updated * until arc_read_done(). */ if (BP_IS_ENCRYPTED(bp)) { abd_t *eabd = arc_get_data_abd(hdr, arc_hdr_size(hdr), hdr, B_TRUE); zio_crypt_decode_params_bp(bp, salt, iv); zio_crypt_decode_mac_bp(bp, mac); ret = spa_do_crypt_abd(B_FALSE, spa, &cb->l2rcb_zb, BP_GET_TYPE(bp), BP_GET_DEDUP(bp), BP_SHOULD_BYTESWAP(bp), salt, iv, mac, HDR_GET_PSIZE(hdr), eabd, hdr->b_l1hdr.b_pabd, &no_crypt); if (ret != 0) { arc_free_data_abd(hdr, eabd, arc_hdr_size(hdr), hdr); goto error; } /* * If we actually performed decryption, replace b_pabd * with the decrypted data. Otherwise we can just throw * our decryption buffer away. */ if (!no_crypt) { arc_free_data_abd(hdr, hdr->b_l1hdr.b_pabd, arc_hdr_size(hdr), hdr); hdr->b_l1hdr.b_pabd = eabd; zio->io_abd = eabd; } else { arc_free_data_abd(hdr, eabd, arc_hdr_size(hdr), hdr); } } /* * If the L2ARC block was compressed, but ARC compression * is disabled we decompress the data into a new buffer and * replace the existing data. */ if (HDR_GET_COMPRESS(hdr) != ZIO_COMPRESS_OFF && !HDR_COMPRESSION_ENABLED(hdr)) { abd_t *cabd = arc_get_data_abd(hdr, arc_hdr_size(hdr), hdr, B_TRUE); void *tmp = abd_borrow_buf(cabd, arc_hdr_size(hdr)); ret = zio_decompress_data(HDR_GET_COMPRESS(hdr), hdr->b_l1hdr.b_pabd, tmp, HDR_GET_PSIZE(hdr), HDR_GET_LSIZE(hdr), &hdr->b_complevel); if (ret != 0) { abd_return_buf_copy(cabd, tmp, arc_hdr_size(hdr)); arc_free_data_abd(hdr, cabd, arc_hdr_size(hdr), hdr); goto error; } abd_return_buf_copy(cabd, tmp, arc_hdr_size(hdr)); arc_free_data_abd(hdr, hdr->b_l1hdr.b_pabd, arc_hdr_size(hdr), hdr); hdr->b_l1hdr.b_pabd = cabd; zio->io_abd = cabd; zio->io_size = HDR_GET_LSIZE(hdr); } return (0); error: return (ret); } /* * A read to a cache device completed. Validate buffer contents before * handing over to the regular ARC routines. */ static void l2arc_read_done(zio_t *zio) { int tfm_error = 0; l2arc_read_callback_t *cb = zio->io_private; arc_buf_hdr_t *hdr; kmutex_t *hash_lock; boolean_t valid_cksum; boolean_t using_rdata = (BP_IS_ENCRYPTED(&cb->l2rcb_bp) && (cb->l2rcb_flags & ZIO_FLAG_RAW_ENCRYPT)); ASSERT3P(zio->io_vd, !=, NULL); ASSERT(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE); spa_config_exit(zio->io_spa, SCL_L2ARC, zio->io_vd); ASSERT3P(cb, !=, NULL); hdr = cb->l2rcb_hdr; ASSERT3P(hdr, !=, NULL); hash_lock = HDR_LOCK(hdr); mutex_enter(hash_lock); ASSERT3P(hash_lock, ==, HDR_LOCK(hdr)); /* * If the data was read into a temporary buffer, * move it and free the buffer. */ if (cb->l2rcb_abd != NULL) { ASSERT3U(arc_hdr_size(hdr), <, zio->io_size); if (zio->io_error == 0) { if (using_rdata) { abd_copy(hdr->b_crypt_hdr.b_rabd, cb->l2rcb_abd, arc_hdr_size(hdr)); } else { abd_copy(hdr->b_l1hdr.b_pabd, cb->l2rcb_abd, arc_hdr_size(hdr)); } } /* * The following must be done regardless of whether * there was an error: * - free the temporary buffer * - point zio to the real ARC buffer * - set zio size accordingly * These are required because zio is either re-used for * an I/O of the block in the case of the error * or the zio is passed to arc_read_done() and it * needs real data. */ abd_free(cb->l2rcb_abd); zio->io_size = zio->io_orig_size = arc_hdr_size(hdr); if (using_rdata) { ASSERT(HDR_HAS_RABD(hdr)); zio->io_abd = zio->io_orig_abd = hdr->b_crypt_hdr.b_rabd; } else { ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL); zio->io_abd = zio->io_orig_abd = hdr->b_l1hdr.b_pabd; } } ASSERT3P(zio->io_abd, !=, NULL); /* * Check this survived the L2ARC journey. */ ASSERT(zio->io_abd == hdr->b_l1hdr.b_pabd || (HDR_HAS_RABD(hdr) && zio->io_abd == hdr->b_crypt_hdr.b_rabd)); zio->io_bp_copy = cb->l2rcb_bp; /* XXX fix in L2ARC 2.0 */ zio->io_bp = &zio->io_bp_copy; /* XXX fix in L2ARC 2.0 */ zio->io_prop.zp_complevel = hdr->b_complevel; valid_cksum = arc_cksum_is_equal(hdr, zio); /* * b_rabd will always match the data as it exists on disk if it is * being used. Therefore if we are reading into b_rabd we do not * attempt to untransform the data. */ if (valid_cksum && !using_rdata) tfm_error = l2arc_untransform(zio, cb); if (valid_cksum && tfm_error == 0 && zio->io_error == 0 && !HDR_L2_EVICTED(hdr)) { mutex_exit(hash_lock); zio->io_private = hdr; arc_read_done(zio); } else { /* * Buffer didn't survive caching. Increment stats and * reissue to the original storage device. */ if (zio->io_error != 0) { ARCSTAT_BUMP(arcstat_l2_io_error); } else { zio->io_error = SET_ERROR(EIO); } if (!valid_cksum || tfm_error != 0) ARCSTAT_BUMP(arcstat_l2_cksum_bad); /* * If there's no waiter, issue an async i/o to the primary * storage now. If there *is* a waiter, the caller must * issue the i/o in a context where it's OK to block. */ if (zio->io_waiter == NULL) { zio_t *pio = zio_unique_parent(zio); void *abd = (using_rdata) ? hdr->b_crypt_hdr.b_rabd : hdr->b_l1hdr.b_pabd; ASSERT(!pio || pio->io_child_type == ZIO_CHILD_LOGICAL); zio = zio_read(pio, zio->io_spa, zio->io_bp, abd, zio->io_size, arc_read_done, hdr, zio->io_priority, cb->l2rcb_flags, &cb->l2rcb_zb); /* * Original ZIO will be freed, so we need to update * ARC header with the new ZIO pointer to be used * by zio_change_priority() in arc_read(). */ for (struct arc_callback *acb = hdr->b_l1hdr.b_acb; acb != NULL; acb = acb->acb_next) acb->acb_zio_head = zio; mutex_exit(hash_lock); zio_nowait(zio); } else { mutex_exit(hash_lock); } } kmem_free(cb, sizeof (l2arc_read_callback_t)); } /* * This is the list priority from which the L2ARC will search for pages to * cache. This is used within loops (0..3) to cycle through lists in the * desired order. This order can have a significant effect on cache * performance. * * Currently the metadata lists are hit first, MFU then MRU, followed by * the data lists. This function returns a locked list, and also returns * the lock pointer. */ static multilist_sublist_t * l2arc_sublist_lock(int list_num) { multilist_t *ml = NULL; unsigned int idx; ASSERT(list_num >= 0 && list_num < L2ARC_FEED_TYPES); switch (list_num) { case 0: ml = arc_mfu->arcs_list[ARC_BUFC_METADATA]; break; case 1: ml = arc_mru->arcs_list[ARC_BUFC_METADATA]; break; case 2: ml = arc_mfu->arcs_list[ARC_BUFC_DATA]; break; case 3: ml = arc_mru->arcs_list[ARC_BUFC_DATA]; break; default: return (NULL); } /* * Return a randomly-selected sublist. This is acceptable * because the caller feeds only a little bit of data for each * call (8MB). Subsequent calls will result in different * sublists being selected. */ idx = multilist_get_random_index(ml); return (multilist_sublist_lock(ml, idx)); } /* * Calculates the maximum overhead of L2ARC metadata log blocks for a given * L2ARC write size. l2arc_evict and l2arc_write_size need to include this * overhead in processing to make sure there is enough headroom available * when writing buffers. */ static inline uint64_t l2arc_log_blk_overhead(uint64_t write_sz, l2arc_dev_t *dev) { if (dev->l2ad_log_entries == 0) { return (0); } else { uint64_t log_entries = write_sz >> SPA_MINBLOCKSHIFT; uint64_t log_blocks = (log_entries + dev->l2ad_log_entries - 1) / dev->l2ad_log_entries; return (vdev_psize_to_asize(dev->l2ad_vdev, sizeof (l2arc_log_blk_phys_t)) * log_blocks); } } /* * Evict buffers from the device write hand to the distance specified in * bytes. This distance may span populated buffers, it may span nothing. * This is clearing a region on the L2ARC device ready for writing. * If the 'all' boolean is set, every buffer is evicted. */ static void l2arc_evict(l2arc_dev_t *dev, uint64_t distance, boolean_t all) { list_t *buflist; arc_buf_hdr_t *hdr, *hdr_prev; kmutex_t *hash_lock; uint64_t taddr; l2arc_lb_ptr_buf_t *lb_ptr_buf, *lb_ptr_buf_prev; vdev_t *vd = dev->l2ad_vdev; boolean_t rerun; buflist = &dev->l2ad_buflist; /* * We need to add in the worst case scenario of log block overhead. */ distance += l2arc_log_blk_overhead(distance, dev); if (vd->vdev_has_trim && l2arc_trim_ahead > 0) { /* * Trim ahead of the write size 64MB or (l2arc_trim_ahead/100) * times the write size, whichever is greater. */ distance += MAX(64 * 1024 * 1024, (distance * l2arc_trim_ahead) / 100); } top: rerun = B_FALSE; if (dev->l2ad_hand >= (dev->l2ad_end - distance)) { /* * When there is no space to accommodate upcoming writes, * evict to the end. Then bump the write and evict hands * to the start and iterate. This iteration does not * happen indefinitely as we make sure in * l2arc_write_size() that when the write hand is reset, * the write size does not exceed the end of the device. */ rerun = B_TRUE; taddr = dev->l2ad_end; } else { taddr = dev->l2ad_hand + distance; } DTRACE_PROBE4(l2arc__evict, l2arc_dev_t *, dev, list_t *, buflist, uint64_t, taddr, boolean_t, all); if (!all) { /* * This check has to be placed after deciding whether to * iterate (rerun). */ if (dev->l2ad_first) { /* * This is the first sweep through the device. There is * nothing to evict. We have already trimmmed the * whole device. */ goto out; } else { /* * Trim the space to be evicted. */ if (vd->vdev_has_trim && dev->l2ad_evict < taddr && l2arc_trim_ahead > 0) { /* * We have to drop the spa_config lock because * vdev_trim_range() will acquire it. * l2ad_evict already accounts for the label * size. To prevent vdev_trim_ranges() from * adding it again, we subtract it from * l2ad_evict. */ spa_config_exit(dev->l2ad_spa, SCL_L2ARC, dev); vdev_trim_simple(vd, dev->l2ad_evict - VDEV_LABEL_START_SIZE, taddr - dev->l2ad_evict); spa_config_enter(dev->l2ad_spa, SCL_L2ARC, dev, RW_READER); } /* * When rebuilding L2ARC we retrieve the evict hand * from the header of the device. Of note, l2arc_evict() * does not actually delete buffers from the cache * device, but trimming may do so depending on the * hardware implementation. Thus keeping track of the * evict hand is useful. */ dev->l2ad_evict = MAX(dev->l2ad_evict, taddr); } } retry: mutex_enter(&dev->l2ad_mtx); /* * We have to account for evicted log blocks. Run vdev_space_update() * on log blocks whose offset (in bytes) is before the evicted offset * (in bytes) by searching in the list of pointers to log blocks * present in the L2ARC device. */ for (lb_ptr_buf = list_tail(&dev->l2ad_lbptr_list); lb_ptr_buf; lb_ptr_buf = lb_ptr_buf_prev) { lb_ptr_buf_prev = list_prev(&dev->l2ad_lbptr_list, lb_ptr_buf); /* L2BLK_GET_PSIZE returns aligned size for log blocks */ uint64_t asize = L2BLK_GET_PSIZE( (lb_ptr_buf->lb_ptr)->lbp_prop); /* * We don't worry about log blocks left behind (ie * lbp_payload_start < l2ad_hand) because l2arc_write_buffers() * will never write more than l2arc_evict() evicts. */ if (!all && l2arc_log_blkptr_valid(dev, lb_ptr_buf->lb_ptr)) { break; } else { vdev_space_update(vd, -asize, 0, 0); ARCSTAT_INCR(arcstat_l2_log_blk_asize, -asize); ARCSTAT_BUMPDOWN(arcstat_l2_log_blk_count); zfs_refcount_remove_many(&dev->l2ad_lb_asize, asize, lb_ptr_buf); zfs_refcount_remove(&dev->l2ad_lb_count, lb_ptr_buf); list_remove(&dev->l2ad_lbptr_list, lb_ptr_buf); kmem_free(lb_ptr_buf->lb_ptr, sizeof (l2arc_log_blkptr_t)); kmem_free(lb_ptr_buf, sizeof (l2arc_lb_ptr_buf_t)); } } for (hdr = list_tail(buflist); hdr; hdr = hdr_prev) { hdr_prev = list_prev(buflist, hdr); ASSERT(!HDR_EMPTY(hdr)); hash_lock = HDR_LOCK(hdr); /* * We cannot use mutex_enter or else we can deadlock * with l2arc_write_buffers (due to swapping the order * the hash lock and l2ad_mtx are taken). */ if (!mutex_tryenter(hash_lock)) { /* * Missed the hash lock. Retry. */ ARCSTAT_BUMP(arcstat_l2_evict_lock_retry); mutex_exit(&dev->l2ad_mtx); mutex_enter(hash_lock); mutex_exit(hash_lock); goto retry; } /* * A header can't be on this list if it doesn't have L2 header. */ ASSERT(HDR_HAS_L2HDR(hdr)); /* Ensure this header has finished being written. */ ASSERT(!HDR_L2_WRITING(hdr)); ASSERT(!HDR_L2_WRITE_HEAD(hdr)); if (!all && (hdr->b_l2hdr.b_daddr >= dev->l2ad_evict || hdr->b_l2hdr.b_daddr < dev->l2ad_hand)) { /* * We've evicted to the target address, * or the end of the device. */ mutex_exit(hash_lock); break; } if (!HDR_HAS_L1HDR(hdr)) { ASSERT(!HDR_L2_READING(hdr)); /* * This doesn't exist in the ARC. Destroy. * arc_hdr_destroy() will call list_remove() * and decrement arcstat_l2_lsize. */ arc_change_state(arc_anon, hdr, hash_lock); arc_hdr_destroy(hdr); } else { ASSERT(hdr->b_l1hdr.b_state != arc_l2c_only); ARCSTAT_BUMP(arcstat_l2_evict_l1cached); /* * Invalidate issued or about to be issued * reads, since we may be about to write * over this location. */ if (HDR_L2_READING(hdr)) { ARCSTAT_BUMP(arcstat_l2_evict_reading); arc_hdr_set_flags(hdr, ARC_FLAG_L2_EVICTED); } arc_hdr_l2hdr_destroy(hdr); } mutex_exit(hash_lock); } mutex_exit(&dev->l2ad_mtx); out: /* * We need to check if we evict all buffers, otherwise we may iterate * unnecessarily. */ if (!all && rerun) { /* * Bump device hand to the device start if it is approaching the * end. l2arc_evict() has already evicted ahead for this case. */ dev->l2ad_hand = dev->l2ad_start; dev->l2ad_evict = dev->l2ad_start; dev->l2ad_first = B_FALSE; goto top; } if (!all) { /* * In case of cache device removal (all) the following * assertions may be violated without functional consequences * as the device is about to be removed. */ ASSERT3U(dev->l2ad_hand + distance, <, dev->l2ad_end); if (!dev->l2ad_first) ASSERT3U(dev->l2ad_hand, <, dev->l2ad_evict); } } /* * Handle any abd transforms that might be required for writing to the L2ARC. * If successful, this function will always return an abd with the data * transformed as it is on disk in a new abd of asize bytes. */ static int l2arc_apply_transforms(spa_t *spa, arc_buf_hdr_t *hdr, uint64_t asize, abd_t **abd_out) { int ret; void *tmp = NULL; abd_t *cabd = NULL, *eabd = NULL, *to_write = hdr->b_l1hdr.b_pabd; enum zio_compress compress = HDR_GET_COMPRESS(hdr); uint64_t psize = HDR_GET_PSIZE(hdr); uint64_t size = arc_hdr_size(hdr); boolean_t ismd = HDR_ISTYPE_METADATA(hdr); boolean_t bswap = (hdr->b_l1hdr.b_byteswap != DMU_BSWAP_NUMFUNCS); dsl_crypto_key_t *dck = NULL; uint8_t mac[ZIO_DATA_MAC_LEN] = { 0 }; boolean_t no_crypt = B_FALSE; ASSERT((HDR_GET_COMPRESS(hdr) != ZIO_COMPRESS_OFF && !HDR_COMPRESSION_ENABLED(hdr)) || HDR_ENCRYPTED(hdr) || HDR_SHARED_DATA(hdr) || psize != asize); ASSERT3U(psize, <=, asize); /* * If this data simply needs its own buffer, we simply allocate it * and copy the data. This may be done to eliminate a dependency on a * shared buffer or to reallocate the buffer to match asize. */ if (HDR_HAS_RABD(hdr) && asize != psize) { ASSERT3U(asize, >=, psize); to_write = abd_alloc_for_io(asize, ismd); abd_copy(to_write, hdr->b_crypt_hdr.b_rabd, psize); if (psize != asize) abd_zero_off(to_write, psize, asize - psize); goto out; } if ((compress == ZIO_COMPRESS_OFF || HDR_COMPRESSION_ENABLED(hdr)) && !HDR_ENCRYPTED(hdr)) { ASSERT3U(size, ==, psize); to_write = abd_alloc_for_io(asize, ismd); abd_copy(to_write, hdr->b_l1hdr.b_pabd, size); if (size != asize) abd_zero_off(to_write, size, asize - size); goto out; } if (compress != ZIO_COMPRESS_OFF && !HDR_COMPRESSION_ENABLED(hdr)) { cabd = abd_alloc_for_io(asize, ismd); tmp = abd_borrow_buf(cabd, asize); psize = zio_compress_data(compress, to_write, tmp, size, hdr->b_complevel); if (psize >= size) { abd_return_buf(cabd, tmp, asize); HDR_SET_COMPRESS(hdr, ZIO_COMPRESS_OFF); to_write = cabd; abd_copy(to_write, hdr->b_l1hdr.b_pabd, size); if (size != asize) abd_zero_off(to_write, size, asize - size); goto encrypt; } ASSERT3U(psize, <=, HDR_GET_PSIZE(hdr)); if (psize < asize) bzero((char *)tmp + psize, asize - psize); psize = HDR_GET_PSIZE(hdr); abd_return_buf_copy(cabd, tmp, asize); to_write = cabd; } encrypt: if (HDR_ENCRYPTED(hdr)) { eabd = abd_alloc_for_io(asize, ismd); /* * If the dataset was disowned before the buffer * made it to this point, the key to re-encrypt * it won't be available. In this case we simply * won't write the buffer to the L2ARC. */ ret = spa_keystore_lookup_key(spa, hdr->b_crypt_hdr.b_dsobj, FTAG, &dck); if (ret != 0) goto error; ret = zio_do_crypt_abd(B_TRUE, &dck->dck_key, hdr->b_crypt_hdr.b_ot, bswap, hdr->b_crypt_hdr.b_salt, hdr->b_crypt_hdr.b_iv, mac, psize, to_write, eabd, &no_crypt); if (ret != 0) goto error; if (no_crypt) abd_copy(eabd, to_write, psize); if (psize != asize) abd_zero_off(eabd, psize, asize - psize); /* assert that the MAC we got here matches the one we saved */ ASSERT0(bcmp(mac, hdr->b_crypt_hdr.b_mac, ZIO_DATA_MAC_LEN)); spa_keystore_dsl_key_rele(spa, dck, FTAG); if (to_write == cabd) abd_free(cabd); to_write = eabd; } out: ASSERT3P(to_write, !=, hdr->b_l1hdr.b_pabd); *abd_out = to_write; return (0); error: if (dck != NULL) spa_keystore_dsl_key_rele(spa, dck, FTAG); if (cabd != NULL) abd_free(cabd); if (eabd != NULL) abd_free(eabd); *abd_out = NULL; return (ret); } static void l2arc_blk_fetch_done(zio_t *zio) { l2arc_read_callback_t *cb; cb = zio->io_private; if (cb->l2rcb_abd != NULL) - abd_put(cb->l2rcb_abd); + abd_free(cb->l2rcb_abd); kmem_free(cb, sizeof (l2arc_read_callback_t)); } /* * Find and write ARC buffers to the L2ARC device. * * An ARC_FLAG_L2_WRITING flag is set so that the L2ARC buffers are not valid * for reading until they have completed writing. * The headroom_boost is an in-out parameter used to maintain headroom boost * state between calls to this function. * * Returns the number of bytes actually written (which may be smaller than * the delta by which the device hand has changed due to alignment and the * writing of log blocks). */ static uint64_t l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz) { arc_buf_hdr_t *hdr, *hdr_prev, *head; uint64_t write_asize, write_psize, write_lsize, headroom; boolean_t full; l2arc_write_callback_t *cb = NULL; zio_t *pio, *wzio; uint64_t guid = spa_load_guid(spa); ASSERT3P(dev->l2ad_vdev, !=, NULL); pio = NULL; write_lsize = write_asize = write_psize = 0; full = B_FALSE; head = kmem_cache_alloc(hdr_l2only_cache, KM_PUSHPAGE); arc_hdr_set_flags(head, ARC_FLAG_L2_WRITE_HEAD | ARC_FLAG_HAS_L2HDR); /* * Copy buffers for L2ARC writing. */ for (int try = 0; try < L2ARC_FEED_TYPES; try++) { /* * If try == 1 or 3, we cache MRU metadata and data * respectively. */ if (l2arc_mfuonly) { if (try == 1 || try == 3) continue; } multilist_sublist_t *mls = l2arc_sublist_lock(try); uint64_t passed_sz = 0; VERIFY3P(mls, !=, NULL); /* * L2ARC fast warmup. * * Until the ARC is warm and starts to evict, read from the * head of the ARC lists rather than the tail. */ if (arc_warm == B_FALSE) hdr = multilist_sublist_head(mls); else hdr = multilist_sublist_tail(mls); headroom = target_sz * l2arc_headroom; if (zfs_compressed_arc_enabled) headroom = (headroom * l2arc_headroom_boost) / 100; for (; hdr; hdr = hdr_prev) { kmutex_t *hash_lock; abd_t *to_write = NULL; if (arc_warm == B_FALSE) hdr_prev = multilist_sublist_next(mls, hdr); else hdr_prev = multilist_sublist_prev(mls, hdr); hash_lock = HDR_LOCK(hdr); if (!mutex_tryenter(hash_lock)) { /* * Skip this buffer rather than waiting. */ continue; } passed_sz += HDR_GET_LSIZE(hdr); if (l2arc_headroom != 0 && passed_sz > headroom) { /* * Searched too far. */ mutex_exit(hash_lock); break; } if (!l2arc_write_eligible(guid, hdr)) { mutex_exit(hash_lock); continue; } /* * We rely on the L1 portion of the header below, so * it's invalid for this header to have been evicted out * of the ghost cache, prior to being written out. The * ARC_FLAG_L2_WRITING bit ensures this won't happen. */ ASSERT(HDR_HAS_L1HDR(hdr)); ASSERT3U(HDR_GET_PSIZE(hdr), >, 0); ASSERT3U(arc_hdr_size(hdr), >, 0); ASSERT(hdr->b_l1hdr.b_pabd != NULL || HDR_HAS_RABD(hdr)); uint64_t psize = HDR_GET_PSIZE(hdr); uint64_t asize = vdev_psize_to_asize(dev->l2ad_vdev, psize); if ((write_asize + asize) > target_sz) { full = B_TRUE; mutex_exit(hash_lock); break; } /* * We rely on the L1 portion of the header below, so * it's invalid for this header to have been evicted out * of the ghost cache, prior to being written out. The * ARC_FLAG_L2_WRITING bit ensures this won't happen. */ arc_hdr_set_flags(hdr, ARC_FLAG_L2_WRITING); ASSERT(HDR_HAS_L1HDR(hdr)); ASSERT3U(HDR_GET_PSIZE(hdr), >, 0); ASSERT(hdr->b_l1hdr.b_pabd != NULL || HDR_HAS_RABD(hdr)); ASSERT3U(arc_hdr_size(hdr), >, 0); /* * If this header has b_rabd, we can use this since it * must always match the data exactly as it exists on * disk. Otherwise, the L2ARC can normally use the * hdr's data, but if we're sharing data between the * hdr and one of its bufs, L2ARC needs its own copy of * the data so that the ZIO below can't race with the * buf consumer. To ensure that this copy will be * available for the lifetime of the ZIO and be cleaned * up afterwards, we add it to the l2arc_free_on_write * queue. If we need to apply any transforms to the * data (compression, encryption) we will also need the * extra buffer. */ if (HDR_HAS_RABD(hdr) && psize == asize) { to_write = hdr->b_crypt_hdr.b_rabd; } else if ((HDR_COMPRESSION_ENABLED(hdr) || HDR_GET_COMPRESS(hdr) == ZIO_COMPRESS_OFF) && !HDR_ENCRYPTED(hdr) && !HDR_SHARED_DATA(hdr) && psize == asize) { to_write = hdr->b_l1hdr.b_pabd; } else { int ret; arc_buf_contents_t type = arc_buf_type(hdr); ret = l2arc_apply_transforms(spa, hdr, asize, &to_write); if (ret != 0) { arc_hdr_clear_flags(hdr, ARC_FLAG_L2_WRITING); mutex_exit(hash_lock); continue; } l2arc_free_abd_on_write(to_write, asize, type); } if (pio == NULL) { /* * Insert a dummy header on the buflist so * l2arc_write_done() can find where the * write buffers begin without searching. */ mutex_enter(&dev->l2ad_mtx); list_insert_head(&dev->l2ad_buflist, head); mutex_exit(&dev->l2ad_mtx); cb = kmem_alloc( sizeof (l2arc_write_callback_t), KM_SLEEP); cb->l2wcb_dev = dev; cb->l2wcb_head = head; /* * Create a list to save allocated abd buffers * for l2arc_log_blk_commit(). */ list_create(&cb->l2wcb_abd_list, sizeof (l2arc_lb_abd_buf_t), offsetof(l2arc_lb_abd_buf_t, node)); pio = zio_root(spa, l2arc_write_done, cb, ZIO_FLAG_CANFAIL); } hdr->b_l2hdr.b_dev = dev; hdr->b_l2hdr.b_hits = 0; hdr->b_l2hdr.b_daddr = dev->l2ad_hand; hdr->b_l2hdr.b_arcs_state = hdr->b_l1hdr.b_state->arcs_state; arc_hdr_set_flags(hdr, ARC_FLAG_HAS_L2HDR); mutex_enter(&dev->l2ad_mtx); list_insert_head(&dev->l2ad_buflist, hdr); mutex_exit(&dev->l2ad_mtx); (void) zfs_refcount_add_many(&dev->l2ad_alloc, arc_hdr_size(hdr), hdr); wzio = zio_write_phys(pio, dev->l2ad_vdev, hdr->b_l2hdr.b_daddr, asize, to_write, ZIO_CHECKSUM_OFF, NULL, hdr, ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_CANFAIL, B_FALSE); write_lsize += HDR_GET_LSIZE(hdr); DTRACE_PROBE2(l2arc__write, vdev_t *, dev->l2ad_vdev, zio_t *, wzio); write_psize += psize; write_asize += asize; dev->l2ad_hand += asize; l2arc_hdr_arcstats_increment(hdr); vdev_space_update(dev->l2ad_vdev, asize, 0, 0); mutex_exit(hash_lock); /* * Append buf info to current log and commit if full. * arcstat_l2_{size,asize} kstats are updated * internally. */ if (l2arc_log_blk_insert(dev, hdr)) l2arc_log_blk_commit(dev, pio, cb); zio_nowait(wzio); } multilist_sublist_unlock(mls); if (full == B_TRUE) break; } /* No buffers selected for writing? */ if (pio == NULL) { ASSERT0(write_lsize); ASSERT(!HDR_HAS_L1HDR(head)); kmem_cache_free(hdr_l2only_cache, head); /* * Although we did not write any buffers l2ad_evict may * have advanced. */ l2arc_dev_hdr_update(dev); return (0); } if (!dev->l2ad_first) ASSERT3U(dev->l2ad_hand, <=, dev->l2ad_evict); ASSERT3U(write_asize, <=, target_sz); ARCSTAT_BUMP(arcstat_l2_writes_sent); ARCSTAT_INCR(arcstat_l2_write_bytes, write_psize); dev->l2ad_writing = B_TRUE; (void) zio_wait(pio); dev->l2ad_writing = B_FALSE; /* * Update the device header after the zio completes as * l2arc_write_done() may have updated the memory holding the log block * pointers in the device header. */ l2arc_dev_hdr_update(dev); return (write_asize); } static boolean_t l2arc_hdr_limit_reached(void) { int64_t s = aggsum_upper_bound(&astat_l2_hdr_size); return (arc_reclaim_needed() || (s > arc_meta_limit * 3 / 4) || (s > (arc_warm ? arc_c : arc_c_max) * l2arc_meta_percent / 100)); } /* * This thread feeds the L2ARC at regular intervals. This is the beating * heart of the L2ARC. */ /* ARGSUSED */ static void l2arc_feed_thread(void *unused) { callb_cpr_t cpr; l2arc_dev_t *dev; spa_t *spa; uint64_t size, wrote; clock_t begin, next = ddi_get_lbolt(); fstrans_cookie_t cookie; CALLB_CPR_INIT(&cpr, &l2arc_feed_thr_lock, callb_generic_cpr, FTAG); mutex_enter(&l2arc_feed_thr_lock); cookie = spl_fstrans_mark(); while (l2arc_thread_exit == 0) { CALLB_CPR_SAFE_BEGIN(&cpr); (void) cv_timedwait_idle(&l2arc_feed_thr_cv, &l2arc_feed_thr_lock, next); CALLB_CPR_SAFE_END(&cpr, &l2arc_feed_thr_lock); next = ddi_get_lbolt() + hz; /* * Quick check for L2ARC devices. */ mutex_enter(&l2arc_dev_mtx); if (l2arc_ndev == 0) { mutex_exit(&l2arc_dev_mtx); continue; } mutex_exit(&l2arc_dev_mtx); begin = ddi_get_lbolt(); /* * This selects the next l2arc device to write to, and in * doing so the next spa to feed from: dev->l2ad_spa. This * will return NULL if there are now no l2arc devices or if * they are all faulted. * * If a device is returned, its spa's config lock is also * held to prevent device removal. l2arc_dev_get_next() * will grab and release l2arc_dev_mtx. */ if ((dev = l2arc_dev_get_next()) == NULL) continue; spa = dev->l2ad_spa; ASSERT3P(spa, !=, NULL); /* * If the pool is read-only then force the feed thread to * sleep a little longer. */ if (!spa_writeable(spa)) { next = ddi_get_lbolt() + 5 * l2arc_feed_secs * hz; spa_config_exit(spa, SCL_L2ARC, dev); continue; } /* * Avoid contributing to memory pressure. */ if (l2arc_hdr_limit_reached()) { ARCSTAT_BUMP(arcstat_l2_abort_lowmem); spa_config_exit(spa, SCL_L2ARC, dev); continue; } ARCSTAT_BUMP(arcstat_l2_feeds); size = l2arc_write_size(dev); /* * Evict L2ARC buffers that will be overwritten. */ l2arc_evict(dev, size, B_FALSE); /* * Write ARC buffers. */ wrote = l2arc_write_buffers(spa, dev, size); /* * Calculate interval between writes. */ next = l2arc_write_interval(begin, size, wrote); spa_config_exit(spa, SCL_L2ARC, dev); } spl_fstrans_unmark(cookie); l2arc_thread_exit = 0; cv_broadcast(&l2arc_feed_thr_cv); CALLB_CPR_EXIT(&cpr); /* drops l2arc_feed_thr_lock */ thread_exit(); } boolean_t l2arc_vdev_present(vdev_t *vd) { return (l2arc_vdev_get(vd) != NULL); } /* * Returns the l2arc_dev_t associated with a particular vdev_t or NULL if * the vdev_t isn't an L2ARC device. */ l2arc_dev_t * l2arc_vdev_get(vdev_t *vd) { l2arc_dev_t *dev; mutex_enter(&l2arc_dev_mtx); for (dev = list_head(l2arc_dev_list); dev != NULL; dev = list_next(l2arc_dev_list, dev)) { if (dev->l2ad_vdev == vd) break; } mutex_exit(&l2arc_dev_mtx); return (dev); } /* * Add a vdev for use by the L2ARC. By this point the spa has already * validated the vdev and opened it. */ void l2arc_add_vdev(spa_t *spa, vdev_t *vd) { l2arc_dev_t *adddev; uint64_t l2dhdr_asize; ASSERT(!l2arc_vdev_present(vd)); /* * Create a new l2arc device entry. */ adddev = vmem_zalloc(sizeof (l2arc_dev_t), KM_SLEEP); adddev->l2ad_spa = spa; adddev->l2ad_vdev = vd; /* leave extra size for an l2arc device header */ l2dhdr_asize = adddev->l2ad_dev_hdr_asize = MAX(sizeof (*adddev->l2ad_dev_hdr), 1 << vd->vdev_ashift); adddev->l2ad_start = VDEV_LABEL_START_SIZE + l2dhdr_asize; adddev->l2ad_end = VDEV_LABEL_START_SIZE + vdev_get_min_asize(vd); ASSERT3U(adddev->l2ad_start, <, adddev->l2ad_end); adddev->l2ad_hand = adddev->l2ad_start; adddev->l2ad_evict = adddev->l2ad_start; adddev->l2ad_first = B_TRUE; adddev->l2ad_writing = B_FALSE; adddev->l2ad_trim_all = B_FALSE; list_link_init(&adddev->l2ad_node); adddev->l2ad_dev_hdr = kmem_zalloc(l2dhdr_asize, KM_SLEEP); mutex_init(&adddev->l2ad_mtx, NULL, MUTEX_DEFAULT, NULL); /* * This is a list of all ARC buffers that are still valid on the * device. */ list_create(&adddev->l2ad_buflist, sizeof (arc_buf_hdr_t), offsetof(arc_buf_hdr_t, b_l2hdr.b_l2node)); /* * This is a list of pointers to log blocks that are still present * on the device. */ list_create(&adddev->l2ad_lbptr_list, sizeof (l2arc_lb_ptr_buf_t), offsetof(l2arc_lb_ptr_buf_t, node)); vdev_space_update(vd, 0, 0, adddev->l2ad_end - adddev->l2ad_hand); zfs_refcount_create(&adddev->l2ad_alloc); zfs_refcount_create(&adddev->l2ad_lb_asize); zfs_refcount_create(&adddev->l2ad_lb_count); /* * Add device to global list */ mutex_enter(&l2arc_dev_mtx); list_insert_head(l2arc_dev_list, adddev); atomic_inc_64(&l2arc_ndev); mutex_exit(&l2arc_dev_mtx); /* * Decide if vdev is eligible for L2ARC rebuild */ l2arc_rebuild_vdev(adddev->l2ad_vdev, B_FALSE); } void l2arc_rebuild_vdev(vdev_t *vd, boolean_t reopen) { l2arc_dev_t *dev = NULL; l2arc_dev_hdr_phys_t *l2dhdr; uint64_t l2dhdr_asize; spa_t *spa; dev = l2arc_vdev_get(vd); ASSERT3P(dev, !=, NULL); spa = dev->l2ad_spa; l2dhdr = dev->l2ad_dev_hdr; l2dhdr_asize = dev->l2ad_dev_hdr_asize; /* * The L2ARC has to hold at least the payload of one log block for * them to be restored (persistent L2ARC). The payload of a log block * depends on the amount of its log entries. We always write log blocks * with 1022 entries. How many of them are committed or restored depends * on the size of the L2ARC device. Thus the maximum payload of * one log block is 1022 * SPA_MAXBLOCKSIZE = 16GB. If the L2ARC device * is less than that, we reduce the amount of committed and restored * log entries per block so as to enable persistence. */ if (dev->l2ad_end < l2arc_rebuild_blocks_min_l2size) { dev->l2ad_log_entries = 0; } else { dev->l2ad_log_entries = MIN((dev->l2ad_end - dev->l2ad_start) >> SPA_MAXBLOCKSHIFT, L2ARC_LOG_BLK_MAX_ENTRIES); } /* * Read the device header, if an error is returned do not rebuild L2ARC. */ if (l2arc_dev_hdr_read(dev) == 0 && dev->l2ad_log_entries > 0) { /* * If we are onlining a cache device (vdev_reopen) that was * still present (l2arc_vdev_present()) and rebuild is enabled, * we should evict all ARC buffers and pointers to log blocks * and reclaim their space before restoring its contents to * L2ARC. */ if (reopen) { if (!l2arc_rebuild_enabled) { return; } else { l2arc_evict(dev, 0, B_TRUE); /* start a new log block */ dev->l2ad_log_ent_idx = 0; dev->l2ad_log_blk_payload_asize = 0; dev->l2ad_log_blk_payload_start = 0; } } /* * Just mark the device as pending for a rebuild. We won't * be starting a rebuild in line here as it would block pool * import. Instead spa_load_impl will hand that off to an * async task which will call l2arc_spa_rebuild_start. */ dev->l2ad_rebuild = B_TRUE; } else if (spa_writeable(spa)) { /* * In this case TRIM the whole device if l2arc_trim_ahead > 0, * otherwise create a new header. We zero out the memory holding * the header to reset dh_start_lbps. If we TRIM the whole * device the new header will be written by * vdev_trim_l2arc_thread() at the end of the TRIM to update the * trim_state in the header too. When reading the header, if * trim_state is not VDEV_TRIM_COMPLETE and l2arc_trim_ahead > 0 * we opt to TRIM the whole device again. */ if (l2arc_trim_ahead > 0) { dev->l2ad_trim_all = B_TRUE; } else { bzero(l2dhdr, l2dhdr_asize); l2arc_dev_hdr_update(dev); } } } /* * Remove a vdev from the L2ARC. */ void l2arc_remove_vdev(vdev_t *vd) { l2arc_dev_t *remdev = NULL; /* * Find the device by vdev */ remdev = l2arc_vdev_get(vd); ASSERT3P(remdev, !=, NULL); /* * Cancel any ongoing or scheduled rebuild. */ mutex_enter(&l2arc_rebuild_thr_lock); if (remdev->l2ad_rebuild_began == B_TRUE) { remdev->l2ad_rebuild_cancel = B_TRUE; while (remdev->l2ad_rebuild == B_TRUE) cv_wait(&l2arc_rebuild_thr_cv, &l2arc_rebuild_thr_lock); } mutex_exit(&l2arc_rebuild_thr_lock); /* * Remove device from global list */ mutex_enter(&l2arc_dev_mtx); list_remove(l2arc_dev_list, remdev); l2arc_dev_last = NULL; /* may have been invalidated */ atomic_dec_64(&l2arc_ndev); mutex_exit(&l2arc_dev_mtx); /* * Clear all buflists and ARC references. L2ARC device flush. */ l2arc_evict(remdev, 0, B_TRUE); list_destroy(&remdev->l2ad_buflist); ASSERT(list_is_empty(&remdev->l2ad_lbptr_list)); list_destroy(&remdev->l2ad_lbptr_list); mutex_destroy(&remdev->l2ad_mtx); zfs_refcount_destroy(&remdev->l2ad_alloc); zfs_refcount_destroy(&remdev->l2ad_lb_asize); zfs_refcount_destroy(&remdev->l2ad_lb_count); kmem_free(remdev->l2ad_dev_hdr, remdev->l2ad_dev_hdr_asize); vmem_free(remdev, sizeof (l2arc_dev_t)); } void l2arc_init(void) { l2arc_thread_exit = 0; l2arc_ndev = 0; l2arc_writes_sent = 0; l2arc_writes_done = 0; mutex_init(&l2arc_feed_thr_lock, NULL, MUTEX_DEFAULT, NULL); cv_init(&l2arc_feed_thr_cv, NULL, CV_DEFAULT, NULL); mutex_init(&l2arc_rebuild_thr_lock, NULL, MUTEX_DEFAULT, NULL); cv_init(&l2arc_rebuild_thr_cv, NULL, CV_DEFAULT, NULL); mutex_init(&l2arc_dev_mtx, NULL, MUTEX_DEFAULT, NULL); mutex_init(&l2arc_free_on_write_mtx, NULL, MUTEX_DEFAULT, NULL); l2arc_dev_list = &L2ARC_dev_list; l2arc_free_on_write = &L2ARC_free_on_write; list_create(l2arc_dev_list, sizeof (l2arc_dev_t), offsetof(l2arc_dev_t, l2ad_node)); list_create(l2arc_free_on_write, sizeof (l2arc_data_free_t), offsetof(l2arc_data_free_t, l2df_list_node)); } void l2arc_fini(void) { mutex_destroy(&l2arc_feed_thr_lock); cv_destroy(&l2arc_feed_thr_cv); mutex_destroy(&l2arc_rebuild_thr_lock); cv_destroy(&l2arc_rebuild_thr_cv); mutex_destroy(&l2arc_dev_mtx); mutex_destroy(&l2arc_free_on_write_mtx); list_destroy(l2arc_dev_list); list_destroy(l2arc_free_on_write); } void l2arc_start(void) { if (!(spa_mode_global & SPA_MODE_WRITE)) return; (void) thread_create(NULL, 0, l2arc_feed_thread, NULL, 0, &p0, TS_RUN, defclsyspri); } void l2arc_stop(void) { if (!(spa_mode_global & SPA_MODE_WRITE)) return; mutex_enter(&l2arc_feed_thr_lock); cv_signal(&l2arc_feed_thr_cv); /* kick thread out of startup */ l2arc_thread_exit = 1; while (l2arc_thread_exit != 0) cv_wait(&l2arc_feed_thr_cv, &l2arc_feed_thr_lock); mutex_exit(&l2arc_feed_thr_lock); } /* * Punches out rebuild threads for the L2ARC devices in a spa. This should * be called after pool import from the spa async thread, since starting * these threads directly from spa_import() will make them part of the * "zpool import" context and delay process exit (and thus pool import). */ void l2arc_spa_rebuild_start(spa_t *spa) { ASSERT(MUTEX_HELD(&spa_namespace_lock)); /* * Locate the spa's l2arc devices and kick off rebuild threads. */ for (int i = 0; i < spa->spa_l2cache.sav_count; i++) { l2arc_dev_t *dev = l2arc_vdev_get(spa->spa_l2cache.sav_vdevs[i]); if (dev == NULL) { /* Don't attempt a rebuild if the vdev is UNAVAIL */ continue; } mutex_enter(&l2arc_rebuild_thr_lock); if (dev->l2ad_rebuild && !dev->l2ad_rebuild_cancel) { dev->l2ad_rebuild_began = B_TRUE; (void) thread_create(NULL, 0, l2arc_dev_rebuild_thread, dev, 0, &p0, TS_RUN, minclsyspri); } mutex_exit(&l2arc_rebuild_thr_lock); } } /* * Main entry point for L2ARC rebuilding. */ static void l2arc_dev_rebuild_thread(void *arg) { l2arc_dev_t *dev = arg; VERIFY(!dev->l2ad_rebuild_cancel); VERIFY(dev->l2ad_rebuild); (void) l2arc_rebuild(dev); mutex_enter(&l2arc_rebuild_thr_lock); dev->l2ad_rebuild_began = B_FALSE; dev->l2ad_rebuild = B_FALSE; mutex_exit(&l2arc_rebuild_thr_lock); thread_exit(); } /* * This function implements the actual L2ARC metadata rebuild. It: * starts reading the log block chain and restores each block's contents * to memory (reconstructing arc_buf_hdr_t's). * * Operation stops under any of the following conditions: * * 1) We reach the end of the log block chain. * 2) We encounter *any* error condition (cksum errors, io errors) */ static int l2arc_rebuild(l2arc_dev_t *dev) { vdev_t *vd = dev->l2ad_vdev; spa_t *spa = vd->vdev_spa; int err = 0; l2arc_dev_hdr_phys_t *l2dhdr = dev->l2ad_dev_hdr; l2arc_log_blk_phys_t *this_lb, *next_lb; zio_t *this_io = NULL, *next_io = NULL; l2arc_log_blkptr_t lbps[2]; l2arc_lb_ptr_buf_t *lb_ptr_buf; boolean_t lock_held; this_lb = vmem_zalloc(sizeof (*this_lb), KM_SLEEP); next_lb = vmem_zalloc(sizeof (*next_lb), KM_SLEEP); /* * We prevent device removal while issuing reads to the device, * then during the rebuilding phases we drop this lock again so * that a spa_unload or device remove can be initiated - this is * safe, because the spa will signal us to stop before removing * our device and wait for us to stop. */ spa_config_enter(spa, SCL_L2ARC, vd, RW_READER); lock_held = B_TRUE; /* * Retrieve the persistent L2ARC device state. * L2BLK_GET_PSIZE returns aligned size for log blocks. */ dev->l2ad_evict = MAX(l2dhdr->dh_evict, dev->l2ad_start); dev->l2ad_hand = MAX(l2dhdr->dh_start_lbps[0].lbp_daddr + L2BLK_GET_PSIZE((&l2dhdr->dh_start_lbps[0])->lbp_prop), dev->l2ad_start); dev->l2ad_first = !!(l2dhdr->dh_flags & L2ARC_DEV_HDR_EVICT_FIRST); vd->vdev_trim_action_time = l2dhdr->dh_trim_action_time; vd->vdev_trim_state = l2dhdr->dh_trim_state; /* * In case the zfs module parameter l2arc_rebuild_enabled is false * we do not start the rebuild process. */ if (!l2arc_rebuild_enabled) goto out; /* Prepare the rebuild process */ bcopy(l2dhdr->dh_start_lbps, lbps, sizeof (lbps)); /* Start the rebuild process */ for (;;) { if (!l2arc_log_blkptr_valid(dev, &lbps[0])) break; if ((err = l2arc_log_blk_read(dev, &lbps[0], &lbps[1], this_lb, next_lb, this_io, &next_io)) != 0) goto out; /* * Our memory pressure valve. If the system is running low * on memory, rather than swamping memory with new ARC buf * hdrs, we opt not to rebuild the L2ARC. At this point, * however, we have already set up our L2ARC dev to chain in * new metadata log blocks, so the user may choose to offline/ * online the L2ARC dev at a later time (or re-import the pool) * to reconstruct it (when there's less memory pressure). */ if (l2arc_hdr_limit_reached()) { ARCSTAT_BUMP(arcstat_l2_rebuild_abort_lowmem); cmn_err(CE_NOTE, "System running low on memory, " "aborting L2ARC rebuild."); err = SET_ERROR(ENOMEM); goto out; } spa_config_exit(spa, SCL_L2ARC, vd); lock_held = B_FALSE; /* * Now that we know that the next_lb checks out alright, we * can start reconstruction from this log block. * L2BLK_GET_PSIZE returns aligned size for log blocks. */ uint64_t asize = L2BLK_GET_PSIZE((&lbps[0])->lbp_prop); l2arc_log_blk_restore(dev, this_lb, asize); /* * log block restored, include its pointer in the list of * pointers to log blocks present in the L2ARC device. */ lb_ptr_buf = kmem_zalloc(sizeof (l2arc_lb_ptr_buf_t), KM_SLEEP); lb_ptr_buf->lb_ptr = kmem_zalloc(sizeof (l2arc_log_blkptr_t), KM_SLEEP); bcopy(&lbps[0], lb_ptr_buf->lb_ptr, sizeof (l2arc_log_blkptr_t)); mutex_enter(&dev->l2ad_mtx); list_insert_tail(&dev->l2ad_lbptr_list, lb_ptr_buf); ARCSTAT_INCR(arcstat_l2_log_blk_asize, asize); ARCSTAT_BUMP(arcstat_l2_log_blk_count); zfs_refcount_add_many(&dev->l2ad_lb_asize, asize, lb_ptr_buf); zfs_refcount_add(&dev->l2ad_lb_count, lb_ptr_buf); mutex_exit(&dev->l2ad_mtx); vdev_space_update(vd, asize, 0, 0); /* * Protection against loops of log blocks: * * l2ad_hand l2ad_evict * V V * l2ad_start |=======================================| l2ad_end * -----|||----|||---|||----||| * (3) (2) (1) (0) * ---|||---|||----|||---||| * (7) (6) (5) (4) * * In this situation the pointer of log block (4) passes * l2arc_log_blkptr_valid() but the log block should not be * restored as it is overwritten by the payload of log block * (0). Only log blocks (0)-(3) should be restored. We check * whether l2ad_evict lies in between the payload starting * offset of the next log block (lbps[1].lbp_payload_start) * and the payload starting offset of the present log block * (lbps[0].lbp_payload_start). If true and this isn't the * first pass, we are looping from the beginning and we should * stop. */ if (l2arc_range_check_overlap(lbps[1].lbp_payload_start, lbps[0].lbp_payload_start, dev->l2ad_evict) && !dev->l2ad_first) goto out; cond_resched(); for (;;) { mutex_enter(&l2arc_rebuild_thr_lock); if (dev->l2ad_rebuild_cancel) { dev->l2ad_rebuild = B_FALSE; cv_signal(&l2arc_rebuild_thr_cv); mutex_exit(&l2arc_rebuild_thr_lock); err = SET_ERROR(ECANCELED); goto out; } mutex_exit(&l2arc_rebuild_thr_lock); if (spa_config_tryenter(spa, SCL_L2ARC, vd, RW_READER)) { lock_held = B_TRUE; break; } /* * L2ARC config lock held by somebody in writer, * possibly due to them trying to remove us. They'll * likely to want us to shut down, so after a little * delay, we check l2ad_rebuild_cancel and retry * the lock again. */ delay(1); } /* * Continue with the next log block. */ lbps[0] = lbps[1]; lbps[1] = this_lb->lb_prev_lbp; PTR_SWAP(this_lb, next_lb); this_io = next_io; next_io = NULL; } if (this_io != NULL) l2arc_log_blk_fetch_abort(this_io); out: if (next_io != NULL) l2arc_log_blk_fetch_abort(next_io); vmem_free(this_lb, sizeof (*this_lb)); vmem_free(next_lb, sizeof (*next_lb)); if (!l2arc_rebuild_enabled) { spa_history_log_internal(spa, "L2ARC rebuild", NULL, "disabled"); } else if (err == 0 && zfs_refcount_count(&dev->l2ad_lb_count) > 0) { ARCSTAT_BUMP(arcstat_l2_rebuild_success); spa_history_log_internal(spa, "L2ARC rebuild", NULL, "successful, restored %llu blocks", (u_longlong_t)zfs_refcount_count(&dev->l2ad_lb_count)); } else if (err == 0 && zfs_refcount_count(&dev->l2ad_lb_count) == 0) { /* * No error but also nothing restored, meaning the lbps array * in the device header points to invalid/non-present log * blocks. Reset the header. */ spa_history_log_internal(spa, "L2ARC rebuild", NULL, "no valid log blocks"); bzero(l2dhdr, dev->l2ad_dev_hdr_asize); l2arc_dev_hdr_update(dev); } else if (err == ECANCELED) { /* * In case the rebuild was canceled do not log to spa history * log as the pool may be in the process of being removed. */ zfs_dbgmsg("L2ARC rebuild aborted, restored %llu blocks", zfs_refcount_count(&dev->l2ad_lb_count)); } else if (err != 0) { spa_history_log_internal(spa, "L2ARC rebuild", NULL, "aborted, restored %llu blocks", (u_longlong_t)zfs_refcount_count(&dev->l2ad_lb_count)); } if (lock_held) spa_config_exit(spa, SCL_L2ARC, vd); return (err); } /* * Attempts to read the device header on the provided L2ARC device and writes * it to `hdr'. On success, this function returns 0, otherwise the appropriate * error code is returned. */ static int l2arc_dev_hdr_read(l2arc_dev_t *dev) { int err; uint64_t guid; l2arc_dev_hdr_phys_t *l2dhdr = dev->l2ad_dev_hdr; const uint64_t l2dhdr_asize = dev->l2ad_dev_hdr_asize; abd_t *abd; guid = spa_guid(dev->l2ad_vdev->vdev_spa); abd = abd_get_from_buf(l2dhdr, l2dhdr_asize); err = zio_wait(zio_read_phys(NULL, dev->l2ad_vdev, VDEV_LABEL_START_SIZE, l2dhdr_asize, abd, ZIO_CHECKSUM_LABEL, NULL, NULL, ZIO_PRIORITY_SYNC_READ, ZIO_FLAG_DONT_CACHE | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY | ZIO_FLAG_SPECULATIVE, B_FALSE)); - abd_put(abd); + abd_free(abd); if (err != 0) { ARCSTAT_BUMP(arcstat_l2_rebuild_abort_dh_errors); zfs_dbgmsg("L2ARC IO error (%d) while reading device header, " "vdev guid: %llu", err, dev->l2ad_vdev->vdev_guid); return (err); } if (l2dhdr->dh_magic == BSWAP_64(L2ARC_DEV_HDR_MAGIC)) byteswap_uint64_array(l2dhdr, sizeof (*l2dhdr)); if (l2dhdr->dh_magic != L2ARC_DEV_HDR_MAGIC || l2dhdr->dh_spa_guid != guid || l2dhdr->dh_vdev_guid != dev->l2ad_vdev->vdev_guid || l2dhdr->dh_version != L2ARC_PERSISTENT_VERSION || l2dhdr->dh_log_entries != dev->l2ad_log_entries || l2dhdr->dh_end != dev->l2ad_end || !l2arc_range_check_overlap(dev->l2ad_start, dev->l2ad_end, l2dhdr->dh_evict) || (l2dhdr->dh_trim_state != VDEV_TRIM_COMPLETE && l2arc_trim_ahead > 0)) { /* * Attempt to rebuild a device containing no actual dev hdr * or containing a header from some other pool or from another * version of persistent L2ARC. */ ARCSTAT_BUMP(arcstat_l2_rebuild_abort_unsupported); return (SET_ERROR(ENOTSUP)); } return (0); } /* * Reads L2ARC log blocks from storage and validates their contents. * * This function implements a simple fetcher to make sure that while * we're processing one buffer the L2ARC is already fetching the next * one in the chain. * * The arguments this_lp and next_lp point to the current and next log block * address in the block chain. Similarly, this_lb and next_lb hold the * l2arc_log_blk_phys_t's of the current and next L2ARC blk. * * The `this_io' and `next_io' arguments are used for block fetching. * When issuing the first blk IO during rebuild, you should pass NULL for * `this_io'. This function will then issue a sync IO to read the block and * also issue an async IO to fetch the next block in the block chain. The * fetched IO is returned in `next_io'. On subsequent calls to this * function, pass the value returned in `next_io' from the previous call * as `this_io' and a fresh `next_io' pointer to hold the next fetch IO. * Prior to the call, you should initialize your `next_io' pointer to be * NULL. If no fetch IO was issued, the pointer is left set at NULL. * * On success, this function returns 0, otherwise it returns an appropriate * error code. On error the fetching IO is aborted and cleared before * returning from this function. Therefore, if we return `success', the * caller can assume that we have taken care of cleanup of fetch IOs. */ static int l2arc_log_blk_read(l2arc_dev_t *dev, const l2arc_log_blkptr_t *this_lbp, const l2arc_log_blkptr_t *next_lbp, l2arc_log_blk_phys_t *this_lb, l2arc_log_blk_phys_t *next_lb, zio_t *this_io, zio_t **next_io) { int err = 0; zio_cksum_t cksum; abd_t *abd = NULL; uint64_t asize; ASSERT(this_lbp != NULL && next_lbp != NULL); ASSERT(this_lb != NULL && next_lb != NULL); ASSERT(next_io != NULL && *next_io == NULL); ASSERT(l2arc_log_blkptr_valid(dev, this_lbp)); /* * Check to see if we have issued the IO for this log block in a * previous run. If not, this is the first call, so issue it now. */ if (this_io == NULL) { this_io = l2arc_log_blk_fetch(dev->l2ad_vdev, this_lbp, this_lb); } /* * Peek to see if we can start issuing the next IO immediately. */ if (l2arc_log_blkptr_valid(dev, next_lbp)) { /* * Start issuing IO for the next log block early - this * should help keep the L2ARC device busy while we * decompress and restore this log block. */ *next_io = l2arc_log_blk_fetch(dev->l2ad_vdev, next_lbp, next_lb); } /* Wait for the IO to read this log block to complete */ if ((err = zio_wait(this_io)) != 0) { ARCSTAT_BUMP(arcstat_l2_rebuild_abort_io_errors); zfs_dbgmsg("L2ARC IO error (%d) while reading log block, " "offset: %llu, vdev guid: %llu", err, this_lbp->lbp_daddr, dev->l2ad_vdev->vdev_guid); goto cleanup; } /* * Make sure the buffer checks out. * L2BLK_GET_PSIZE returns aligned size for log blocks. */ asize = L2BLK_GET_PSIZE((this_lbp)->lbp_prop); fletcher_4_native(this_lb, asize, NULL, &cksum); if (!ZIO_CHECKSUM_EQUAL(cksum, this_lbp->lbp_cksum)) { ARCSTAT_BUMP(arcstat_l2_rebuild_abort_cksum_lb_errors); zfs_dbgmsg("L2ARC log block cksum failed, offset: %llu, " "vdev guid: %llu, l2ad_hand: %llu, l2ad_evict: %llu", this_lbp->lbp_daddr, dev->l2ad_vdev->vdev_guid, dev->l2ad_hand, dev->l2ad_evict); err = SET_ERROR(ECKSUM); goto cleanup; } /* Now we can take our time decoding this buffer */ switch (L2BLK_GET_COMPRESS((this_lbp)->lbp_prop)) { case ZIO_COMPRESS_OFF: break; case ZIO_COMPRESS_LZ4: abd = abd_alloc_for_io(asize, B_TRUE); abd_copy_from_buf_off(abd, this_lb, 0, asize); if ((err = zio_decompress_data( L2BLK_GET_COMPRESS((this_lbp)->lbp_prop), abd, this_lb, asize, sizeof (*this_lb), NULL)) != 0) { err = SET_ERROR(EINVAL); goto cleanup; } break; default: err = SET_ERROR(EINVAL); goto cleanup; } if (this_lb->lb_magic == BSWAP_64(L2ARC_LOG_BLK_MAGIC)) byteswap_uint64_array(this_lb, sizeof (*this_lb)); if (this_lb->lb_magic != L2ARC_LOG_BLK_MAGIC) { err = SET_ERROR(EINVAL); goto cleanup; } cleanup: /* Abort an in-flight fetch I/O in case of error */ if (err != 0 && *next_io != NULL) { l2arc_log_blk_fetch_abort(*next_io); *next_io = NULL; } if (abd != NULL) abd_free(abd); return (err); } /* * Restores the payload of a log block to ARC. This creates empty ARC hdr * entries which only contain an l2arc hdr, essentially restoring the * buffers to their L2ARC evicted state. This function also updates space * usage on the L2ARC vdev to make sure it tracks restored buffers. */ static void l2arc_log_blk_restore(l2arc_dev_t *dev, const l2arc_log_blk_phys_t *lb, uint64_t lb_asize) { uint64_t size = 0, asize = 0; uint64_t log_entries = dev->l2ad_log_entries; /* * Usually arc_adapt() is called only for data, not headers, but * since we may allocate significant amount of memory here, let ARC * grow its arc_c. */ arc_adapt(log_entries * HDR_L2ONLY_SIZE, arc_l2c_only); for (int i = log_entries - 1; i >= 0; i--) { /* * Restore goes in the reverse temporal direction to preserve * correct temporal ordering of buffers in the l2ad_buflist. * l2arc_hdr_restore also does a list_insert_tail instead of * list_insert_head on the l2ad_buflist: * * LIST l2ad_buflist LIST * HEAD <------ (time) ------ TAIL * direction +-----+-----+-----+-----+-----+ direction * of l2arc <== | buf | buf | buf | buf | buf | ===> of rebuild * fill +-----+-----+-----+-----+-----+ * ^ ^ * | | * | | * l2arc_feed_thread l2arc_rebuild * will place new bufs here restores bufs here * * During l2arc_rebuild() the device is not used by * l2arc_feed_thread() as dev->l2ad_rebuild is set to true. */ size += L2BLK_GET_LSIZE((&lb->lb_entries[i])->le_prop); asize += vdev_psize_to_asize(dev->l2ad_vdev, L2BLK_GET_PSIZE((&lb->lb_entries[i])->le_prop)); l2arc_hdr_restore(&lb->lb_entries[i], dev); } /* * Record rebuild stats: * size Logical size of restored buffers in the L2ARC * asize Aligned size of restored buffers in the L2ARC */ ARCSTAT_INCR(arcstat_l2_rebuild_size, size); ARCSTAT_INCR(arcstat_l2_rebuild_asize, asize); ARCSTAT_INCR(arcstat_l2_rebuild_bufs, log_entries); ARCSTAT_F_AVG(arcstat_l2_log_blk_avg_asize, lb_asize); ARCSTAT_F_AVG(arcstat_l2_data_to_meta_ratio, asize / lb_asize); ARCSTAT_BUMP(arcstat_l2_rebuild_log_blks); } /* * Restores a single ARC buf hdr from a log entry. The ARC buffer is put * into a state indicating that it has been evicted to L2ARC. */ static void l2arc_hdr_restore(const l2arc_log_ent_phys_t *le, l2arc_dev_t *dev) { arc_buf_hdr_t *hdr, *exists; kmutex_t *hash_lock; arc_buf_contents_t type = L2BLK_GET_TYPE((le)->le_prop); uint64_t asize; /* * Do all the allocation before grabbing any locks, this lets us * sleep if memory is full and we don't have to deal with failed * allocations. */ hdr = arc_buf_alloc_l2only(L2BLK_GET_LSIZE((le)->le_prop), type, dev, le->le_dva, le->le_daddr, L2BLK_GET_PSIZE((le)->le_prop), le->le_birth, L2BLK_GET_COMPRESS((le)->le_prop), le->le_complevel, L2BLK_GET_PROTECTED((le)->le_prop), L2BLK_GET_PREFETCH((le)->le_prop), L2BLK_GET_STATE((le)->le_prop)); asize = vdev_psize_to_asize(dev->l2ad_vdev, L2BLK_GET_PSIZE((le)->le_prop)); /* * vdev_space_update() has to be called before arc_hdr_destroy() to * avoid underflow since the latter also calls vdev_space_update(). */ l2arc_hdr_arcstats_increment(hdr); vdev_space_update(dev->l2ad_vdev, asize, 0, 0); mutex_enter(&dev->l2ad_mtx); list_insert_tail(&dev->l2ad_buflist, hdr); (void) zfs_refcount_add_many(&dev->l2ad_alloc, arc_hdr_size(hdr), hdr); mutex_exit(&dev->l2ad_mtx); exists = buf_hash_insert(hdr, &hash_lock); if (exists) { /* Buffer was already cached, no need to restore it. */ arc_hdr_destroy(hdr); /* * If the buffer is already cached, check whether it has * L2ARC metadata. If not, enter them and update the flag. * This is important is case of onlining a cache device, since * we previously evicted all L2ARC metadata from ARC. */ if (!HDR_HAS_L2HDR(exists)) { arc_hdr_set_flags(exists, ARC_FLAG_HAS_L2HDR); exists->b_l2hdr.b_dev = dev; exists->b_l2hdr.b_daddr = le->le_daddr; exists->b_l2hdr.b_arcs_state = L2BLK_GET_STATE((le)->le_prop); mutex_enter(&dev->l2ad_mtx); list_insert_tail(&dev->l2ad_buflist, exists); (void) zfs_refcount_add_many(&dev->l2ad_alloc, arc_hdr_size(exists), exists); mutex_exit(&dev->l2ad_mtx); l2arc_hdr_arcstats_increment(exists); vdev_space_update(dev->l2ad_vdev, asize, 0, 0); } ARCSTAT_BUMP(arcstat_l2_rebuild_bufs_precached); } mutex_exit(hash_lock); } /* * Starts an asynchronous read IO to read a log block. This is used in log * block reconstruction to start reading the next block before we are done * decoding and reconstructing the current block, to keep the l2arc device * nice and hot with read IO to process. * The returned zio will contain a newly allocated memory buffers for the IO * data which should then be freed by the caller once the zio is no longer * needed (i.e. due to it having completed). If you wish to abort this * zio, you should do so using l2arc_log_blk_fetch_abort, which takes * care of disposing of the allocated buffers correctly. */ static zio_t * l2arc_log_blk_fetch(vdev_t *vd, const l2arc_log_blkptr_t *lbp, l2arc_log_blk_phys_t *lb) { uint32_t asize; zio_t *pio; l2arc_read_callback_t *cb; /* L2BLK_GET_PSIZE returns aligned size for log blocks */ asize = L2BLK_GET_PSIZE((lbp)->lbp_prop); ASSERT(asize <= sizeof (l2arc_log_blk_phys_t)); cb = kmem_zalloc(sizeof (l2arc_read_callback_t), KM_SLEEP); cb->l2rcb_abd = abd_get_from_buf(lb, asize); pio = zio_root(vd->vdev_spa, l2arc_blk_fetch_done, cb, ZIO_FLAG_DONT_CACHE | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY); (void) zio_nowait(zio_read_phys(pio, vd, lbp->lbp_daddr, asize, cb->l2rcb_abd, ZIO_CHECKSUM_OFF, NULL, NULL, ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_DONT_CACHE | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY, B_FALSE)); return (pio); } /* * Aborts a zio returned from l2arc_log_blk_fetch and frees the data * buffers allocated for it. */ static void l2arc_log_blk_fetch_abort(zio_t *zio) { (void) zio_wait(zio); } /* * Creates a zio to update the device header on an l2arc device. */ void l2arc_dev_hdr_update(l2arc_dev_t *dev) { l2arc_dev_hdr_phys_t *l2dhdr = dev->l2ad_dev_hdr; const uint64_t l2dhdr_asize = dev->l2ad_dev_hdr_asize; abd_t *abd; int err; VERIFY(spa_config_held(dev->l2ad_spa, SCL_STATE_ALL, RW_READER)); l2dhdr->dh_magic = L2ARC_DEV_HDR_MAGIC; l2dhdr->dh_version = L2ARC_PERSISTENT_VERSION; l2dhdr->dh_spa_guid = spa_guid(dev->l2ad_vdev->vdev_spa); l2dhdr->dh_vdev_guid = dev->l2ad_vdev->vdev_guid; l2dhdr->dh_log_entries = dev->l2ad_log_entries; l2dhdr->dh_evict = dev->l2ad_evict; l2dhdr->dh_start = dev->l2ad_start; l2dhdr->dh_end = dev->l2ad_end; l2dhdr->dh_lb_asize = zfs_refcount_count(&dev->l2ad_lb_asize); l2dhdr->dh_lb_count = zfs_refcount_count(&dev->l2ad_lb_count); l2dhdr->dh_flags = 0; l2dhdr->dh_trim_action_time = dev->l2ad_vdev->vdev_trim_action_time; l2dhdr->dh_trim_state = dev->l2ad_vdev->vdev_trim_state; if (dev->l2ad_first) l2dhdr->dh_flags |= L2ARC_DEV_HDR_EVICT_FIRST; abd = abd_get_from_buf(l2dhdr, l2dhdr_asize); err = zio_wait(zio_write_phys(NULL, dev->l2ad_vdev, VDEV_LABEL_START_SIZE, l2dhdr_asize, abd, ZIO_CHECKSUM_LABEL, NULL, NULL, ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_CANFAIL, B_FALSE)); - abd_put(abd); + abd_free(abd); if (err != 0) { zfs_dbgmsg("L2ARC IO error (%d) while writing device header, " "vdev guid: %llu", err, dev->l2ad_vdev->vdev_guid); } } /* * Commits a log block to the L2ARC device. This routine is invoked from * l2arc_write_buffers when the log block fills up. * This function allocates some memory to temporarily hold the serialized * buffer to be written. This is then released in l2arc_write_done. */ static void l2arc_log_blk_commit(l2arc_dev_t *dev, zio_t *pio, l2arc_write_callback_t *cb) { l2arc_log_blk_phys_t *lb = &dev->l2ad_log_blk; l2arc_dev_hdr_phys_t *l2dhdr = dev->l2ad_dev_hdr; uint64_t psize, asize; zio_t *wzio; l2arc_lb_abd_buf_t *abd_buf; uint8_t *tmpbuf; l2arc_lb_ptr_buf_t *lb_ptr_buf; VERIFY3S(dev->l2ad_log_ent_idx, ==, dev->l2ad_log_entries); tmpbuf = zio_buf_alloc(sizeof (*lb)); abd_buf = zio_buf_alloc(sizeof (*abd_buf)); abd_buf->abd = abd_get_from_buf(lb, sizeof (*lb)); lb_ptr_buf = kmem_zalloc(sizeof (l2arc_lb_ptr_buf_t), KM_SLEEP); lb_ptr_buf->lb_ptr = kmem_zalloc(sizeof (l2arc_log_blkptr_t), KM_SLEEP); /* link the buffer into the block chain */ lb->lb_prev_lbp = l2dhdr->dh_start_lbps[1]; lb->lb_magic = L2ARC_LOG_BLK_MAGIC; /* * l2arc_log_blk_commit() may be called multiple times during a single * l2arc_write_buffers() call. Save the allocated abd buffers in a list * so we can free them in l2arc_write_done() later on. */ list_insert_tail(&cb->l2wcb_abd_list, abd_buf); /* try to compress the buffer */ psize = zio_compress_data(ZIO_COMPRESS_LZ4, abd_buf->abd, tmpbuf, sizeof (*lb), 0); /* a log block is never entirely zero */ ASSERT(psize != 0); asize = vdev_psize_to_asize(dev->l2ad_vdev, psize); ASSERT(asize <= sizeof (*lb)); /* * Update the start log block pointer in the device header to point * to the log block we're about to write. */ l2dhdr->dh_start_lbps[1] = l2dhdr->dh_start_lbps[0]; l2dhdr->dh_start_lbps[0].lbp_daddr = dev->l2ad_hand; l2dhdr->dh_start_lbps[0].lbp_payload_asize = dev->l2ad_log_blk_payload_asize; l2dhdr->dh_start_lbps[0].lbp_payload_start = dev->l2ad_log_blk_payload_start; _NOTE(CONSTCOND) L2BLK_SET_LSIZE( (&l2dhdr->dh_start_lbps[0])->lbp_prop, sizeof (*lb)); L2BLK_SET_PSIZE( (&l2dhdr->dh_start_lbps[0])->lbp_prop, asize); L2BLK_SET_CHECKSUM( (&l2dhdr->dh_start_lbps[0])->lbp_prop, ZIO_CHECKSUM_FLETCHER_4); if (asize < sizeof (*lb)) { /* compression succeeded */ bzero(tmpbuf + psize, asize - psize); L2BLK_SET_COMPRESS( (&l2dhdr->dh_start_lbps[0])->lbp_prop, ZIO_COMPRESS_LZ4); } else { /* compression failed */ bcopy(lb, tmpbuf, sizeof (*lb)); L2BLK_SET_COMPRESS( (&l2dhdr->dh_start_lbps[0])->lbp_prop, ZIO_COMPRESS_OFF); } /* checksum what we're about to write */ fletcher_4_native(tmpbuf, asize, NULL, &l2dhdr->dh_start_lbps[0].lbp_cksum); - abd_put(abd_buf->abd); + abd_free(abd_buf->abd); /* perform the write itself */ abd_buf->abd = abd_get_from_buf(tmpbuf, sizeof (*lb)); abd_take_ownership_of_buf(abd_buf->abd, B_TRUE); wzio = zio_write_phys(pio, dev->l2ad_vdev, dev->l2ad_hand, asize, abd_buf->abd, ZIO_CHECKSUM_OFF, NULL, NULL, ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_CANFAIL, B_FALSE); DTRACE_PROBE2(l2arc__write, vdev_t *, dev->l2ad_vdev, zio_t *, wzio); (void) zio_nowait(wzio); dev->l2ad_hand += asize; /* * Include the committed log block's pointer in the list of pointers * to log blocks present in the L2ARC device. */ bcopy(&l2dhdr->dh_start_lbps[0], lb_ptr_buf->lb_ptr, sizeof (l2arc_log_blkptr_t)); mutex_enter(&dev->l2ad_mtx); list_insert_head(&dev->l2ad_lbptr_list, lb_ptr_buf); ARCSTAT_INCR(arcstat_l2_log_blk_asize, asize); ARCSTAT_BUMP(arcstat_l2_log_blk_count); zfs_refcount_add_many(&dev->l2ad_lb_asize, asize, lb_ptr_buf); zfs_refcount_add(&dev->l2ad_lb_count, lb_ptr_buf); mutex_exit(&dev->l2ad_mtx); vdev_space_update(dev->l2ad_vdev, asize, 0, 0); /* bump the kstats */ ARCSTAT_INCR(arcstat_l2_write_bytes, asize); ARCSTAT_BUMP(arcstat_l2_log_blk_writes); ARCSTAT_F_AVG(arcstat_l2_log_blk_avg_asize, asize); ARCSTAT_F_AVG(arcstat_l2_data_to_meta_ratio, dev->l2ad_log_blk_payload_asize / asize); /* start a new log block */ dev->l2ad_log_ent_idx = 0; dev->l2ad_log_blk_payload_asize = 0; dev->l2ad_log_blk_payload_start = 0; } /* * Validates an L2ARC log block address to make sure that it can be read * from the provided L2ARC device. */ boolean_t l2arc_log_blkptr_valid(l2arc_dev_t *dev, const l2arc_log_blkptr_t *lbp) { /* L2BLK_GET_PSIZE returns aligned size for log blocks */ uint64_t asize = L2BLK_GET_PSIZE((lbp)->lbp_prop); uint64_t end = lbp->lbp_daddr + asize - 1; uint64_t start = lbp->lbp_payload_start; boolean_t evicted = B_FALSE; /* * A log block is valid if all of the following conditions are true: * - it fits entirely (including its payload) between l2ad_start and * l2ad_end * - it has a valid size * - neither the log block itself nor part of its payload was evicted * by l2arc_evict(): * * l2ad_hand l2ad_evict * | | lbp_daddr * | start | | end * | | | | | * V V V V V * l2ad_start ============================================ l2ad_end * --------------------------|||| * ^ ^ * | log block * payload */ evicted = l2arc_range_check_overlap(start, end, dev->l2ad_hand) || l2arc_range_check_overlap(start, end, dev->l2ad_evict) || l2arc_range_check_overlap(dev->l2ad_hand, dev->l2ad_evict, start) || l2arc_range_check_overlap(dev->l2ad_hand, dev->l2ad_evict, end); return (start >= dev->l2ad_start && end <= dev->l2ad_end && asize > 0 && asize <= sizeof (l2arc_log_blk_phys_t) && (!evicted || dev->l2ad_first)); } /* * Inserts ARC buffer header `hdr' into the current L2ARC log block on * the device. The buffer being inserted must be present in L2ARC. * Returns B_TRUE if the L2ARC log block is full and needs to be committed * to L2ARC, or B_FALSE if it still has room for more ARC buffers. */ static boolean_t l2arc_log_blk_insert(l2arc_dev_t *dev, const arc_buf_hdr_t *hdr) { l2arc_log_blk_phys_t *lb = &dev->l2ad_log_blk; l2arc_log_ent_phys_t *le; if (dev->l2ad_log_entries == 0) return (B_FALSE); int index = dev->l2ad_log_ent_idx++; ASSERT3S(index, <, dev->l2ad_log_entries); ASSERT(HDR_HAS_L2HDR(hdr)); le = &lb->lb_entries[index]; bzero(le, sizeof (*le)); le->le_dva = hdr->b_dva; le->le_birth = hdr->b_birth; le->le_daddr = hdr->b_l2hdr.b_daddr; if (index == 0) dev->l2ad_log_blk_payload_start = le->le_daddr; L2BLK_SET_LSIZE((le)->le_prop, HDR_GET_LSIZE(hdr)); L2BLK_SET_PSIZE((le)->le_prop, HDR_GET_PSIZE(hdr)); L2BLK_SET_COMPRESS((le)->le_prop, HDR_GET_COMPRESS(hdr)); le->le_complevel = hdr->b_complevel; L2BLK_SET_TYPE((le)->le_prop, hdr->b_type); L2BLK_SET_PROTECTED((le)->le_prop, !!(HDR_PROTECTED(hdr))); L2BLK_SET_PREFETCH((le)->le_prop, !!(HDR_PREFETCH(hdr))); L2BLK_SET_STATE((le)->le_prop, hdr->b_l1hdr.b_state->arcs_state); dev->l2ad_log_blk_payload_asize += vdev_psize_to_asize(dev->l2ad_vdev, HDR_GET_PSIZE(hdr)); return (dev->l2ad_log_ent_idx == dev->l2ad_log_entries); } /* * Checks whether a given L2ARC device address sits in a time-sequential * range. The trick here is that the L2ARC is a rotary buffer, so we can't * just do a range comparison, we need to handle the situation in which the * range wraps around the end of the L2ARC device. Arguments: * bottom -- Lower end of the range to check (written to earlier). * top -- Upper end of the range to check (written to later). * check -- The address for which we want to determine if it sits in * between the top and bottom. * * The 3-way conditional below represents the following cases: * * bottom < top : Sequentially ordered case: * --------+-------------------+ * | (overlap here?) | * L2ARC dev V V * |---------------============--------------| * * bottom > top: Looped-around case: * --------+------------------+ * | (overlap here?) | * L2ARC dev V V * |===============---------------===========| * ^ ^ * | (or here?) | * +---------------+--------- * * top == bottom : Just a single address comparison. */ boolean_t l2arc_range_check_overlap(uint64_t bottom, uint64_t top, uint64_t check) { if (bottom < top) return (bottom <= check && check <= top); else if (bottom > top) return (check <= top || bottom <= check); else return (check == top); } EXPORT_SYMBOL(arc_buf_size); EXPORT_SYMBOL(arc_write); EXPORT_SYMBOL(arc_read); EXPORT_SYMBOL(arc_buf_info); EXPORT_SYMBOL(arc_getbuf_func); EXPORT_SYMBOL(arc_add_prune_callback); EXPORT_SYMBOL(arc_remove_prune_callback); /* BEGIN CSTYLED */ ZFS_MODULE_PARAM_CALL(zfs_arc, zfs_arc_, min, param_set_arc_long, param_get_long, ZMOD_RW, "Min arc size"); ZFS_MODULE_PARAM_CALL(zfs_arc, zfs_arc_, max, param_set_arc_long, param_get_long, ZMOD_RW, "Max arc size"); ZFS_MODULE_PARAM_CALL(zfs_arc, zfs_arc_, meta_limit, param_set_arc_long, param_get_long, ZMOD_RW, "Metadata limit for arc size"); ZFS_MODULE_PARAM_CALL(zfs_arc, zfs_arc_, meta_limit_percent, param_set_arc_long, param_get_long, ZMOD_RW, "Percent of arc size for arc meta limit"); ZFS_MODULE_PARAM_CALL(zfs_arc, zfs_arc_, meta_min, param_set_arc_long, param_get_long, ZMOD_RW, "Min arc metadata"); ZFS_MODULE_PARAM(zfs_arc, zfs_arc_, meta_prune, INT, ZMOD_RW, "Meta objects to scan for prune"); ZFS_MODULE_PARAM(zfs_arc, zfs_arc_, meta_adjust_restarts, INT, ZMOD_RW, "Limit number of restarts in arc_evict_meta"); ZFS_MODULE_PARAM(zfs_arc, zfs_arc_, meta_strategy, INT, ZMOD_RW, "Meta reclaim strategy"); ZFS_MODULE_PARAM_CALL(zfs_arc, zfs_arc_, grow_retry, param_set_arc_int, param_get_int, ZMOD_RW, "Seconds before growing arc size"); ZFS_MODULE_PARAM(zfs_arc, zfs_arc_, p_dampener_disable, INT, ZMOD_RW, "Disable arc_p adapt dampener"); ZFS_MODULE_PARAM_CALL(zfs_arc, zfs_arc_, shrink_shift, param_set_arc_int, param_get_int, ZMOD_RW, "log2(fraction of arc to reclaim)"); ZFS_MODULE_PARAM(zfs_arc, zfs_arc_, pc_percent, UINT, ZMOD_RW, "Percent of pagecache to reclaim arc to"); ZFS_MODULE_PARAM_CALL(zfs_arc, zfs_arc_, p_min_shift, param_set_arc_int, param_get_int, ZMOD_RW, "arc_c shift to calc min/max arc_p"); ZFS_MODULE_PARAM(zfs_arc, zfs_arc_, average_blocksize, INT, ZMOD_RD, "Target average block size"); ZFS_MODULE_PARAM(zfs, zfs_, compressed_arc_enabled, INT, ZMOD_RW, "Disable compressed arc buffers"); ZFS_MODULE_PARAM_CALL(zfs_arc, zfs_arc_, min_prefetch_ms, param_set_arc_int, param_get_int, ZMOD_RW, "Min life of prefetch block in ms"); ZFS_MODULE_PARAM_CALL(zfs_arc, zfs_arc_, min_prescient_prefetch_ms, param_set_arc_int, param_get_int, ZMOD_RW, "Min life of prescient prefetched block in ms"); ZFS_MODULE_PARAM(zfs_l2arc, l2arc_, write_max, ULONG, ZMOD_RW, "Max write bytes per interval"); ZFS_MODULE_PARAM(zfs_l2arc, l2arc_, write_boost, ULONG, ZMOD_RW, "Extra write bytes during device warmup"); ZFS_MODULE_PARAM(zfs_l2arc, l2arc_, headroom, ULONG, ZMOD_RW, "Number of max device writes to precache"); ZFS_MODULE_PARAM(zfs_l2arc, l2arc_, headroom_boost, ULONG, ZMOD_RW, "Compressed l2arc_headroom multiplier"); ZFS_MODULE_PARAM(zfs_l2arc, l2arc_, trim_ahead, ULONG, ZMOD_RW, "TRIM ahead L2ARC write size multiplier"); ZFS_MODULE_PARAM(zfs_l2arc, l2arc_, feed_secs, ULONG, ZMOD_RW, "Seconds between L2ARC writing"); ZFS_MODULE_PARAM(zfs_l2arc, l2arc_, feed_min_ms, ULONG, ZMOD_RW, "Min feed interval in milliseconds"); ZFS_MODULE_PARAM(zfs_l2arc, l2arc_, noprefetch, INT, ZMOD_RW, "Skip caching prefetched buffers"); ZFS_MODULE_PARAM(zfs_l2arc, l2arc_, feed_again, INT, ZMOD_RW, "Turbo L2ARC warmup"); ZFS_MODULE_PARAM(zfs_l2arc, l2arc_, norw, INT, ZMOD_RW, "No reads during writes"); ZFS_MODULE_PARAM(zfs_l2arc, l2arc_, meta_percent, INT, ZMOD_RW, "Percent of ARC size allowed for L2ARC-only headers"); ZFS_MODULE_PARAM(zfs_l2arc, l2arc_, rebuild_enabled, INT, ZMOD_RW, "Rebuild the L2ARC when importing a pool"); ZFS_MODULE_PARAM(zfs_l2arc, l2arc_, rebuild_blocks_min_l2size, ULONG, ZMOD_RW, "Min size in bytes to write rebuild log blocks in L2ARC"); ZFS_MODULE_PARAM(zfs_l2arc, l2arc_, mfuonly, INT, ZMOD_RW, "Cache only MFU data from ARC into L2ARC"); ZFS_MODULE_PARAM_CALL(zfs_arc, zfs_arc_, lotsfree_percent, param_set_arc_int, param_get_int, ZMOD_RW, "System free memory I/O throttle in bytes"); ZFS_MODULE_PARAM_CALL(zfs_arc, zfs_arc_, sys_free, param_set_arc_long, param_get_long, ZMOD_RW, "System free memory target size in bytes"); ZFS_MODULE_PARAM_CALL(zfs_arc, zfs_arc_, dnode_limit, param_set_arc_long, param_get_long, ZMOD_RW, "Minimum bytes of dnodes in arc"); ZFS_MODULE_PARAM_CALL(zfs_arc, zfs_arc_, dnode_limit_percent, param_set_arc_long, param_get_long, ZMOD_RW, "Percent of ARC meta buffers for dnodes"); ZFS_MODULE_PARAM(zfs_arc, zfs_arc_, dnode_reduce_percent, ULONG, ZMOD_RW, "Percentage of excess dnodes to try to unpin"); ZFS_MODULE_PARAM(zfs_arc, zfs_arc_, eviction_pct, INT, ZMOD_RW, "When full, ARC allocation waits for eviction of this % of alloc size"); ZFS_MODULE_PARAM(zfs_arc, zfs_arc_, evict_batch_limit, INT, ZMOD_RW, "The number of headers to evict per sublist before moving to the next"); /* END CSTYLED */ diff --git a/module/zfs/dbuf.c b/module/zfs/dbuf.c index 93445a80294b..a6cdc017cd21 100644 --- a/module/zfs/dbuf.c +++ b/module/zfs/dbuf.c @@ -1,4958 +1,4958 @@ /* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. * Copyright 2011 Nexenta Systems, Inc. All rights reserved. * Copyright (c) 2012, 2020 by Delphix. All rights reserved. * Copyright (c) 2013 by Saso Kiselkov. All rights reserved. * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved. * Copyright (c) 2019, Klara Inc. * Copyright (c) 2019, Allan Jude */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include kstat_t *dbuf_ksp; typedef struct dbuf_stats { /* * Various statistics about the size of the dbuf cache. */ kstat_named_t cache_count; kstat_named_t cache_size_bytes; kstat_named_t cache_size_bytes_max; /* * Statistics regarding the bounds on the dbuf cache size. */ kstat_named_t cache_target_bytes; kstat_named_t cache_lowater_bytes; kstat_named_t cache_hiwater_bytes; /* * Total number of dbuf cache evictions that have occurred. */ kstat_named_t cache_total_evicts; /* * The distribution of dbuf levels in the dbuf cache and * the total size of all dbufs at each level. */ kstat_named_t cache_levels[DN_MAX_LEVELS]; kstat_named_t cache_levels_bytes[DN_MAX_LEVELS]; /* * Statistics about the dbuf hash table. */ kstat_named_t hash_hits; kstat_named_t hash_misses; kstat_named_t hash_collisions; kstat_named_t hash_elements; kstat_named_t hash_elements_max; /* * Number of sublists containing more than one dbuf in the dbuf * hash table. Keep track of the longest hash chain. */ kstat_named_t hash_chains; kstat_named_t hash_chain_max; /* * Number of times a dbuf_create() discovers that a dbuf was * already created and in the dbuf hash table. */ kstat_named_t hash_insert_race; /* * Statistics about the size of the metadata dbuf cache. */ kstat_named_t metadata_cache_count; kstat_named_t metadata_cache_size_bytes; kstat_named_t metadata_cache_size_bytes_max; /* * For diagnostic purposes, this is incremented whenever we can't add * something to the metadata cache because it's full, and instead put * the data in the regular dbuf cache. */ kstat_named_t metadata_cache_overflow; } dbuf_stats_t; dbuf_stats_t dbuf_stats = { { "cache_count", KSTAT_DATA_UINT64 }, { "cache_size_bytes", KSTAT_DATA_UINT64 }, { "cache_size_bytes_max", KSTAT_DATA_UINT64 }, { "cache_target_bytes", KSTAT_DATA_UINT64 }, { "cache_lowater_bytes", KSTAT_DATA_UINT64 }, { "cache_hiwater_bytes", KSTAT_DATA_UINT64 }, { "cache_total_evicts", KSTAT_DATA_UINT64 }, { { "cache_levels_N", KSTAT_DATA_UINT64 } }, { { "cache_levels_bytes_N", KSTAT_DATA_UINT64 } }, { "hash_hits", KSTAT_DATA_UINT64 }, { "hash_misses", KSTAT_DATA_UINT64 }, { "hash_collisions", KSTAT_DATA_UINT64 }, { "hash_elements", KSTAT_DATA_UINT64 }, { "hash_elements_max", KSTAT_DATA_UINT64 }, { "hash_chains", KSTAT_DATA_UINT64 }, { "hash_chain_max", KSTAT_DATA_UINT64 }, { "hash_insert_race", KSTAT_DATA_UINT64 }, { "metadata_cache_count", KSTAT_DATA_UINT64 }, { "metadata_cache_size_bytes", KSTAT_DATA_UINT64 }, { "metadata_cache_size_bytes_max", KSTAT_DATA_UINT64 }, { "metadata_cache_overflow", KSTAT_DATA_UINT64 } }; #define DBUF_STAT_INCR(stat, val) \ atomic_add_64(&dbuf_stats.stat.value.ui64, (val)); #define DBUF_STAT_DECR(stat, val) \ DBUF_STAT_INCR(stat, -(val)); #define DBUF_STAT_BUMP(stat) \ DBUF_STAT_INCR(stat, 1); #define DBUF_STAT_BUMPDOWN(stat) \ DBUF_STAT_INCR(stat, -1); #define DBUF_STAT_MAX(stat, v) { \ uint64_t _m; \ while ((v) > (_m = dbuf_stats.stat.value.ui64) && \ (_m != atomic_cas_64(&dbuf_stats.stat.value.ui64, _m, (v))))\ continue; \ } static boolean_t dbuf_undirty(dmu_buf_impl_t *db, dmu_tx_t *tx); static void dbuf_write(dbuf_dirty_record_t *dr, arc_buf_t *data, dmu_tx_t *tx); static void dbuf_sync_leaf_verify_bonus_dnode(dbuf_dirty_record_t *dr); static int dbuf_read_verify_dnode_crypt(dmu_buf_impl_t *db, uint32_t flags); extern inline void dmu_buf_init_user(dmu_buf_user_t *dbu, dmu_buf_evict_func_t *evict_func_sync, dmu_buf_evict_func_t *evict_func_async, dmu_buf_t **clear_on_evict_dbufp); /* * Global data structures and functions for the dbuf cache. */ static kmem_cache_t *dbuf_kmem_cache; static taskq_t *dbu_evict_taskq; static kthread_t *dbuf_cache_evict_thread; static kmutex_t dbuf_evict_lock; static kcondvar_t dbuf_evict_cv; static boolean_t dbuf_evict_thread_exit; /* * There are two dbuf caches; each dbuf can only be in one of them at a time. * * 1. Cache of metadata dbufs, to help make read-heavy administrative commands * from /sbin/zfs run faster. The "metadata cache" specifically stores dbufs * that represent the metadata that describes filesystems/snapshots/ * bookmarks/properties/etc. We only evict from this cache when we export a * pool, to short-circuit as much I/O as possible for all administrative * commands that need the metadata. There is no eviction policy for this * cache, because we try to only include types in it which would occupy a * very small amount of space per object but create a large impact on the * performance of these commands. Instead, after it reaches a maximum size * (which should only happen on very small memory systems with a very large * number of filesystem objects), we stop taking new dbufs into the * metadata cache, instead putting them in the normal dbuf cache. * * 2. LRU cache of dbufs. The dbuf cache maintains a list of dbufs that * are not currently held but have been recently released. These dbufs * are not eligible for arc eviction until they are aged out of the cache. * Dbufs that are aged out of the cache will be immediately destroyed and * become eligible for arc eviction. * * Dbufs are added to these caches once the last hold is released. If a dbuf is * later accessed and still exists in the dbuf cache, then it will be removed * from the cache and later re-added to the head of the cache. * * If a given dbuf meets the requirements for the metadata cache, it will go * there, otherwise it will be considered for the generic LRU dbuf cache. The * caches and the refcounts tracking their sizes are stored in an array indexed * by those caches' matching enum values (from dbuf_cached_state_t). */ typedef struct dbuf_cache { multilist_t *cache; zfs_refcount_t size; } dbuf_cache_t; dbuf_cache_t dbuf_caches[DB_CACHE_MAX]; /* Size limits for the caches */ unsigned long dbuf_cache_max_bytes = ULONG_MAX; unsigned long dbuf_metadata_cache_max_bytes = ULONG_MAX; /* Set the default sizes of the caches to log2 fraction of arc size */ int dbuf_cache_shift = 5; int dbuf_metadata_cache_shift = 6; static unsigned long dbuf_cache_target_bytes(void); static unsigned long dbuf_metadata_cache_target_bytes(void); /* * The LRU dbuf cache uses a three-stage eviction policy: * - A low water marker designates when the dbuf eviction thread * should stop evicting from the dbuf cache. * - When we reach the maximum size (aka mid water mark), we * signal the eviction thread to run. * - The high water mark indicates when the eviction thread * is unable to keep up with the incoming load and eviction must * happen in the context of the calling thread. * * The dbuf cache: * (max size) * low water mid water hi water * +----------------------------------------+----------+----------+ * | | | | * | | | | * | | | | * | | | | * +----------------------------------------+----------+----------+ * stop signal evict * evicting eviction directly * thread * * The high and low water marks indicate the operating range for the eviction * thread. The low water mark is, by default, 90% of the total size of the * cache and the high water mark is at 110% (both of these percentages can be * changed by setting dbuf_cache_lowater_pct and dbuf_cache_hiwater_pct, * respectively). The eviction thread will try to ensure that the cache remains * within this range by waking up every second and checking if the cache is * above the low water mark. The thread can also be woken up by callers adding * elements into the cache if the cache is larger than the mid water (i.e max * cache size). Once the eviction thread is woken up and eviction is required, * it will continue evicting buffers until it's able to reduce the cache size * to the low water mark. If the cache size continues to grow and hits the high * water mark, then callers adding elements to the cache will begin to evict * directly from the cache until the cache is no longer above the high water * mark. */ /* * The percentage above and below the maximum cache size. */ uint_t dbuf_cache_hiwater_pct = 10; uint_t dbuf_cache_lowater_pct = 10; /* ARGSUSED */ static int dbuf_cons(void *vdb, void *unused, int kmflag) { dmu_buf_impl_t *db = vdb; bzero(db, sizeof (dmu_buf_impl_t)); mutex_init(&db->db_mtx, NULL, MUTEX_DEFAULT, NULL); rw_init(&db->db_rwlock, NULL, RW_DEFAULT, NULL); cv_init(&db->db_changed, NULL, CV_DEFAULT, NULL); multilist_link_init(&db->db_cache_link); zfs_refcount_create(&db->db_holds); return (0); } /* ARGSUSED */ static void dbuf_dest(void *vdb, void *unused) { dmu_buf_impl_t *db = vdb; mutex_destroy(&db->db_mtx); rw_destroy(&db->db_rwlock); cv_destroy(&db->db_changed); ASSERT(!multilist_link_active(&db->db_cache_link)); zfs_refcount_destroy(&db->db_holds); } /* * dbuf hash table routines */ static dbuf_hash_table_t dbuf_hash_table; static uint64_t dbuf_hash_count; /* * We use Cityhash for this. It's fast, and has good hash properties without * requiring any large static buffers. */ static uint64_t dbuf_hash(void *os, uint64_t obj, uint8_t lvl, uint64_t blkid) { return (cityhash4((uintptr_t)os, obj, (uint64_t)lvl, blkid)); } #define DTRACE_SET_STATE(db, why) \ DTRACE_PROBE2(dbuf__state_change, dmu_buf_impl_t *, db, \ const char *, why) #define DBUF_EQUAL(dbuf, os, obj, level, blkid) \ ((dbuf)->db.db_object == (obj) && \ (dbuf)->db_objset == (os) && \ (dbuf)->db_level == (level) && \ (dbuf)->db_blkid == (blkid)) dmu_buf_impl_t * dbuf_find(objset_t *os, uint64_t obj, uint8_t level, uint64_t blkid) { dbuf_hash_table_t *h = &dbuf_hash_table; uint64_t hv; uint64_t idx; dmu_buf_impl_t *db; hv = dbuf_hash(os, obj, level, blkid); idx = hv & h->hash_table_mask; mutex_enter(DBUF_HASH_MUTEX(h, idx)); for (db = h->hash_table[idx]; db != NULL; db = db->db_hash_next) { if (DBUF_EQUAL(db, os, obj, level, blkid)) { mutex_enter(&db->db_mtx); if (db->db_state != DB_EVICTING) { mutex_exit(DBUF_HASH_MUTEX(h, idx)); return (db); } mutex_exit(&db->db_mtx); } } mutex_exit(DBUF_HASH_MUTEX(h, idx)); return (NULL); } static dmu_buf_impl_t * dbuf_find_bonus(objset_t *os, uint64_t object) { dnode_t *dn; dmu_buf_impl_t *db = NULL; if (dnode_hold(os, object, FTAG, &dn) == 0) { rw_enter(&dn->dn_struct_rwlock, RW_READER); if (dn->dn_bonus != NULL) { db = dn->dn_bonus; mutex_enter(&db->db_mtx); } rw_exit(&dn->dn_struct_rwlock); dnode_rele(dn, FTAG); } return (db); } /* * Insert an entry into the hash table. If there is already an element * equal to elem in the hash table, then the already existing element * will be returned and the new element will not be inserted. * Otherwise returns NULL. */ static dmu_buf_impl_t * dbuf_hash_insert(dmu_buf_impl_t *db) { dbuf_hash_table_t *h = &dbuf_hash_table; objset_t *os = db->db_objset; uint64_t obj = db->db.db_object; int level = db->db_level; uint64_t blkid, hv, idx; dmu_buf_impl_t *dbf; uint32_t i; blkid = db->db_blkid; hv = dbuf_hash(os, obj, level, blkid); idx = hv & h->hash_table_mask; mutex_enter(DBUF_HASH_MUTEX(h, idx)); for (dbf = h->hash_table[idx], i = 0; dbf != NULL; dbf = dbf->db_hash_next, i++) { if (DBUF_EQUAL(dbf, os, obj, level, blkid)) { mutex_enter(&dbf->db_mtx); if (dbf->db_state != DB_EVICTING) { mutex_exit(DBUF_HASH_MUTEX(h, idx)); return (dbf); } mutex_exit(&dbf->db_mtx); } } if (i > 0) { DBUF_STAT_BUMP(hash_collisions); if (i == 1) DBUF_STAT_BUMP(hash_chains); DBUF_STAT_MAX(hash_chain_max, i); } mutex_enter(&db->db_mtx); db->db_hash_next = h->hash_table[idx]; h->hash_table[idx] = db; mutex_exit(DBUF_HASH_MUTEX(h, idx)); atomic_inc_64(&dbuf_hash_count); DBUF_STAT_MAX(hash_elements_max, dbuf_hash_count); return (NULL); } /* * This returns whether this dbuf should be stored in the metadata cache, which * is based on whether it's from one of the dnode types that store data related * to traversing dataset hierarchies. */ static boolean_t dbuf_include_in_metadata_cache(dmu_buf_impl_t *db) { DB_DNODE_ENTER(db); dmu_object_type_t type = DB_DNODE(db)->dn_type; DB_DNODE_EXIT(db); /* Check if this dbuf is one of the types we care about */ if (DMU_OT_IS_METADATA_CACHED(type)) { /* If we hit this, then we set something up wrong in dmu_ot */ ASSERT(DMU_OT_IS_METADATA(type)); /* * Sanity check for small-memory systems: don't allocate too * much memory for this purpose. */ if (zfs_refcount_count( &dbuf_caches[DB_DBUF_METADATA_CACHE].size) > dbuf_metadata_cache_target_bytes()) { DBUF_STAT_BUMP(metadata_cache_overflow); return (B_FALSE); } return (B_TRUE); } return (B_FALSE); } /* * Remove an entry from the hash table. It must be in the EVICTING state. */ static void dbuf_hash_remove(dmu_buf_impl_t *db) { dbuf_hash_table_t *h = &dbuf_hash_table; uint64_t hv, idx; dmu_buf_impl_t *dbf, **dbp; hv = dbuf_hash(db->db_objset, db->db.db_object, db->db_level, db->db_blkid); idx = hv & h->hash_table_mask; /* * We mustn't hold db_mtx to maintain lock ordering: * DBUF_HASH_MUTEX > db_mtx. */ ASSERT(zfs_refcount_is_zero(&db->db_holds)); ASSERT(db->db_state == DB_EVICTING); ASSERT(!MUTEX_HELD(&db->db_mtx)); mutex_enter(DBUF_HASH_MUTEX(h, idx)); dbp = &h->hash_table[idx]; while ((dbf = *dbp) != db) { dbp = &dbf->db_hash_next; ASSERT(dbf != NULL); } *dbp = db->db_hash_next; db->db_hash_next = NULL; if (h->hash_table[idx] && h->hash_table[idx]->db_hash_next == NULL) DBUF_STAT_BUMPDOWN(hash_chains); mutex_exit(DBUF_HASH_MUTEX(h, idx)); atomic_dec_64(&dbuf_hash_count); } typedef enum { DBVU_EVICTING, DBVU_NOT_EVICTING } dbvu_verify_type_t; static void dbuf_verify_user(dmu_buf_impl_t *db, dbvu_verify_type_t verify_type) { #ifdef ZFS_DEBUG int64_t holds; if (db->db_user == NULL) return; /* Only data blocks support the attachment of user data. */ ASSERT(db->db_level == 0); /* Clients must resolve a dbuf before attaching user data. */ ASSERT(db->db.db_data != NULL); ASSERT3U(db->db_state, ==, DB_CACHED); holds = zfs_refcount_count(&db->db_holds); if (verify_type == DBVU_EVICTING) { /* * Immediate eviction occurs when holds == dirtycnt. * For normal eviction buffers, holds is zero on * eviction, except when dbuf_fix_old_data() calls * dbuf_clear_data(). However, the hold count can grow * during eviction even though db_mtx is held (see * dmu_bonus_hold() for an example), so we can only * test the generic invariant that holds >= dirtycnt. */ ASSERT3U(holds, >=, db->db_dirtycnt); } else { if (db->db_user_immediate_evict == TRUE) ASSERT3U(holds, >=, db->db_dirtycnt); else ASSERT3U(holds, >, 0); } #endif } static void dbuf_evict_user(dmu_buf_impl_t *db) { dmu_buf_user_t *dbu = db->db_user; ASSERT(MUTEX_HELD(&db->db_mtx)); if (dbu == NULL) return; dbuf_verify_user(db, DBVU_EVICTING); db->db_user = NULL; #ifdef ZFS_DEBUG if (dbu->dbu_clear_on_evict_dbufp != NULL) *dbu->dbu_clear_on_evict_dbufp = NULL; #endif /* * There are two eviction callbacks - one that we call synchronously * and one that we invoke via a taskq. The async one is useful for * avoiding lock order reversals and limiting stack depth. * * Note that if we have a sync callback but no async callback, * it's likely that the sync callback will free the structure * containing the dbu. In that case we need to take care to not * dereference dbu after calling the sync evict func. */ boolean_t has_async = (dbu->dbu_evict_func_async != NULL); if (dbu->dbu_evict_func_sync != NULL) dbu->dbu_evict_func_sync(dbu); if (has_async) { taskq_dispatch_ent(dbu_evict_taskq, dbu->dbu_evict_func_async, dbu, 0, &dbu->dbu_tqent); } } boolean_t dbuf_is_metadata(dmu_buf_impl_t *db) { /* * Consider indirect blocks and spill blocks to be meta data. */ if (db->db_level > 0 || db->db_blkid == DMU_SPILL_BLKID) { return (B_TRUE); } else { boolean_t is_metadata; DB_DNODE_ENTER(db); is_metadata = DMU_OT_IS_METADATA(DB_DNODE(db)->dn_type); DB_DNODE_EXIT(db); return (is_metadata); } } /* * This function *must* return indices evenly distributed between all * sublists of the multilist. This is needed due to how the dbuf eviction * code is laid out; dbuf_evict_thread() assumes dbufs are evenly * distributed between all sublists and uses this assumption when * deciding which sublist to evict from and how much to evict from it. */ static unsigned int dbuf_cache_multilist_index_func(multilist_t *ml, void *obj) { dmu_buf_impl_t *db = obj; /* * The assumption here, is the hash value for a given * dmu_buf_impl_t will remain constant throughout it's lifetime * (i.e. it's objset, object, level and blkid fields don't change). * Thus, we don't need to store the dbuf's sublist index * on insertion, as this index can be recalculated on removal. * * Also, the low order bits of the hash value are thought to be * distributed evenly. Otherwise, in the case that the multilist * has a power of two number of sublists, each sublists' usage * would not be evenly distributed. */ return (dbuf_hash(db->db_objset, db->db.db_object, db->db_level, db->db_blkid) % multilist_get_num_sublists(ml)); } /* * The target size of the dbuf cache can grow with the ARC target, * unless limited by the tunable dbuf_cache_max_bytes. */ static inline unsigned long dbuf_cache_target_bytes(void) { return (MIN(dbuf_cache_max_bytes, arc_target_bytes() >> dbuf_cache_shift)); } /* * The target size of the dbuf metadata cache can grow with the ARC target, * unless limited by the tunable dbuf_metadata_cache_max_bytes. */ static inline unsigned long dbuf_metadata_cache_target_bytes(void) { return (MIN(dbuf_metadata_cache_max_bytes, arc_target_bytes() >> dbuf_metadata_cache_shift)); } static inline uint64_t dbuf_cache_hiwater_bytes(void) { uint64_t dbuf_cache_target = dbuf_cache_target_bytes(); return (dbuf_cache_target + (dbuf_cache_target * dbuf_cache_hiwater_pct) / 100); } static inline uint64_t dbuf_cache_lowater_bytes(void) { uint64_t dbuf_cache_target = dbuf_cache_target_bytes(); return (dbuf_cache_target - (dbuf_cache_target * dbuf_cache_lowater_pct) / 100); } static inline boolean_t dbuf_cache_above_lowater(void) { return (zfs_refcount_count(&dbuf_caches[DB_DBUF_CACHE].size) > dbuf_cache_lowater_bytes()); } /* * Evict the oldest eligible dbuf from the dbuf cache. */ static void dbuf_evict_one(void) { int idx = multilist_get_random_index(dbuf_caches[DB_DBUF_CACHE].cache); multilist_sublist_t *mls = multilist_sublist_lock( dbuf_caches[DB_DBUF_CACHE].cache, idx); ASSERT(!MUTEX_HELD(&dbuf_evict_lock)); dmu_buf_impl_t *db = multilist_sublist_tail(mls); while (db != NULL && mutex_tryenter(&db->db_mtx) == 0) { db = multilist_sublist_prev(mls, db); } DTRACE_PROBE2(dbuf__evict__one, dmu_buf_impl_t *, db, multilist_sublist_t *, mls); if (db != NULL) { multilist_sublist_remove(mls, db); multilist_sublist_unlock(mls); (void) zfs_refcount_remove_many( &dbuf_caches[DB_DBUF_CACHE].size, db->db.db_size, db); DBUF_STAT_BUMPDOWN(cache_levels[db->db_level]); DBUF_STAT_BUMPDOWN(cache_count); DBUF_STAT_DECR(cache_levels_bytes[db->db_level], db->db.db_size); ASSERT3U(db->db_caching_status, ==, DB_DBUF_CACHE); db->db_caching_status = DB_NO_CACHE; dbuf_destroy(db); DBUF_STAT_BUMP(cache_total_evicts); } else { multilist_sublist_unlock(mls); } } /* * The dbuf evict thread is responsible for aging out dbufs from the * cache. Once the cache has reached it's maximum size, dbufs are removed * and destroyed. The eviction thread will continue running until the size * of the dbuf cache is at or below the maximum size. Once the dbuf is aged * out of the cache it is destroyed and becomes eligible for arc eviction. */ /* ARGSUSED */ static void dbuf_evict_thread(void *unused) { callb_cpr_t cpr; CALLB_CPR_INIT(&cpr, &dbuf_evict_lock, callb_generic_cpr, FTAG); mutex_enter(&dbuf_evict_lock); while (!dbuf_evict_thread_exit) { while (!dbuf_cache_above_lowater() && !dbuf_evict_thread_exit) { CALLB_CPR_SAFE_BEGIN(&cpr); (void) cv_timedwait_idle_hires(&dbuf_evict_cv, &dbuf_evict_lock, SEC2NSEC(1), MSEC2NSEC(1), 0); CALLB_CPR_SAFE_END(&cpr, &dbuf_evict_lock); } mutex_exit(&dbuf_evict_lock); /* * Keep evicting as long as we're above the low water mark * for the cache. We do this without holding the locks to * minimize lock contention. */ while (dbuf_cache_above_lowater() && !dbuf_evict_thread_exit) { dbuf_evict_one(); } mutex_enter(&dbuf_evict_lock); } dbuf_evict_thread_exit = B_FALSE; cv_broadcast(&dbuf_evict_cv); CALLB_CPR_EXIT(&cpr); /* drops dbuf_evict_lock */ thread_exit(); } /* * Wake up the dbuf eviction thread if the dbuf cache is at its max size. * If the dbuf cache is at its high water mark, then evict a dbuf from the * dbuf cache using the callers context. */ static void dbuf_evict_notify(uint64_t size) { /* * We check if we should evict without holding the dbuf_evict_lock, * because it's OK to occasionally make the wrong decision here, * and grabbing the lock results in massive lock contention. */ if (size > dbuf_cache_target_bytes()) { if (size > dbuf_cache_hiwater_bytes()) dbuf_evict_one(); cv_signal(&dbuf_evict_cv); } } static int dbuf_kstat_update(kstat_t *ksp, int rw) { dbuf_stats_t *ds = ksp->ks_data; if (rw == KSTAT_WRITE) { return (SET_ERROR(EACCES)); } else { ds->metadata_cache_size_bytes.value.ui64 = zfs_refcount_count( &dbuf_caches[DB_DBUF_METADATA_CACHE].size); ds->cache_size_bytes.value.ui64 = zfs_refcount_count(&dbuf_caches[DB_DBUF_CACHE].size); ds->cache_target_bytes.value.ui64 = dbuf_cache_target_bytes(); ds->cache_hiwater_bytes.value.ui64 = dbuf_cache_hiwater_bytes(); ds->cache_lowater_bytes.value.ui64 = dbuf_cache_lowater_bytes(); ds->hash_elements.value.ui64 = dbuf_hash_count; } return (0); } void dbuf_init(void) { uint64_t hsize = 1ULL << 16; dbuf_hash_table_t *h = &dbuf_hash_table; int i; /* * The hash table is big enough to fill all of physical memory * with an average block size of zfs_arc_average_blocksize (default 8K). * By default, the table will take up * totalmem * sizeof(void*) / 8K (1MB per GB with 8-byte pointers). */ while (hsize * zfs_arc_average_blocksize < physmem * PAGESIZE) hsize <<= 1; retry: h->hash_table_mask = hsize - 1; #if defined(_KERNEL) /* * Large allocations which do not require contiguous pages * should be using vmem_alloc() in the linux kernel */ h->hash_table = vmem_zalloc(hsize * sizeof (void *), KM_SLEEP); #else h->hash_table = kmem_zalloc(hsize * sizeof (void *), KM_NOSLEEP); #endif if (h->hash_table == NULL) { /* XXX - we should really return an error instead of assert */ ASSERT(hsize > (1ULL << 10)); hsize >>= 1; goto retry; } dbuf_kmem_cache = kmem_cache_create("dmu_buf_impl_t", sizeof (dmu_buf_impl_t), 0, dbuf_cons, dbuf_dest, NULL, NULL, NULL, 0); for (i = 0; i < DBUF_MUTEXES; i++) mutex_init(&h->hash_mutexes[i], NULL, MUTEX_DEFAULT, NULL); dbuf_stats_init(h); /* * All entries are queued via taskq_dispatch_ent(), so min/maxalloc * configuration is not required. */ dbu_evict_taskq = taskq_create("dbu_evict", 1, defclsyspri, 0, 0, 0); for (dbuf_cached_state_t dcs = 0; dcs < DB_CACHE_MAX; dcs++) { dbuf_caches[dcs].cache = multilist_create(sizeof (dmu_buf_impl_t), offsetof(dmu_buf_impl_t, db_cache_link), dbuf_cache_multilist_index_func); zfs_refcount_create(&dbuf_caches[dcs].size); } dbuf_evict_thread_exit = B_FALSE; mutex_init(&dbuf_evict_lock, NULL, MUTEX_DEFAULT, NULL); cv_init(&dbuf_evict_cv, NULL, CV_DEFAULT, NULL); dbuf_cache_evict_thread = thread_create(NULL, 0, dbuf_evict_thread, NULL, 0, &p0, TS_RUN, minclsyspri); dbuf_ksp = kstat_create("zfs", 0, "dbufstats", "misc", KSTAT_TYPE_NAMED, sizeof (dbuf_stats) / sizeof (kstat_named_t), KSTAT_FLAG_VIRTUAL); if (dbuf_ksp != NULL) { for (i = 0; i < DN_MAX_LEVELS; i++) { snprintf(dbuf_stats.cache_levels[i].name, KSTAT_STRLEN, "cache_level_%d", i); dbuf_stats.cache_levels[i].data_type = KSTAT_DATA_UINT64; snprintf(dbuf_stats.cache_levels_bytes[i].name, KSTAT_STRLEN, "cache_level_%d_bytes", i); dbuf_stats.cache_levels_bytes[i].data_type = KSTAT_DATA_UINT64; } dbuf_ksp->ks_data = &dbuf_stats; dbuf_ksp->ks_update = dbuf_kstat_update; kstat_install(dbuf_ksp); } } void dbuf_fini(void) { dbuf_hash_table_t *h = &dbuf_hash_table; int i; dbuf_stats_destroy(); for (i = 0; i < DBUF_MUTEXES; i++) mutex_destroy(&h->hash_mutexes[i]); #if defined(_KERNEL) /* * Large allocations which do not require contiguous pages * should be using vmem_free() in the linux kernel */ vmem_free(h->hash_table, (h->hash_table_mask + 1) * sizeof (void *)); #else kmem_free(h->hash_table, (h->hash_table_mask + 1) * sizeof (void *)); #endif kmem_cache_destroy(dbuf_kmem_cache); taskq_destroy(dbu_evict_taskq); mutex_enter(&dbuf_evict_lock); dbuf_evict_thread_exit = B_TRUE; while (dbuf_evict_thread_exit) { cv_signal(&dbuf_evict_cv); cv_wait(&dbuf_evict_cv, &dbuf_evict_lock); } mutex_exit(&dbuf_evict_lock); mutex_destroy(&dbuf_evict_lock); cv_destroy(&dbuf_evict_cv); for (dbuf_cached_state_t dcs = 0; dcs < DB_CACHE_MAX; dcs++) { zfs_refcount_destroy(&dbuf_caches[dcs].size); multilist_destroy(dbuf_caches[dcs].cache); } if (dbuf_ksp != NULL) { kstat_delete(dbuf_ksp); dbuf_ksp = NULL; } } /* * Other stuff. */ #ifdef ZFS_DEBUG static void dbuf_verify(dmu_buf_impl_t *db) { dnode_t *dn; dbuf_dirty_record_t *dr; uint32_t txg_prev; ASSERT(MUTEX_HELD(&db->db_mtx)); if (!(zfs_flags & ZFS_DEBUG_DBUF_VERIFY)) return; ASSERT(db->db_objset != NULL); DB_DNODE_ENTER(db); dn = DB_DNODE(db); if (dn == NULL) { ASSERT(db->db_parent == NULL); ASSERT(db->db_blkptr == NULL); } else { ASSERT3U(db->db.db_object, ==, dn->dn_object); ASSERT3P(db->db_objset, ==, dn->dn_objset); ASSERT3U(db->db_level, <, dn->dn_nlevels); ASSERT(db->db_blkid == DMU_BONUS_BLKID || db->db_blkid == DMU_SPILL_BLKID || !avl_is_empty(&dn->dn_dbufs)); } if (db->db_blkid == DMU_BONUS_BLKID) { ASSERT(dn != NULL); ASSERT3U(db->db.db_size, >=, dn->dn_bonuslen); ASSERT3U(db->db.db_offset, ==, DMU_BONUS_BLKID); } else if (db->db_blkid == DMU_SPILL_BLKID) { ASSERT(dn != NULL); ASSERT0(db->db.db_offset); } else { ASSERT3U(db->db.db_offset, ==, db->db_blkid * db->db.db_size); } if ((dr = list_head(&db->db_dirty_records)) != NULL) { ASSERT(dr->dr_dbuf == db); txg_prev = dr->dr_txg; for (dr = list_next(&db->db_dirty_records, dr); dr != NULL; dr = list_next(&db->db_dirty_records, dr)) { ASSERT(dr->dr_dbuf == db); ASSERT(txg_prev > dr->dr_txg); txg_prev = dr->dr_txg; } } /* * We can't assert that db_size matches dn_datablksz because it * can be momentarily different when another thread is doing * dnode_set_blksz(). */ if (db->db_level == 0 && db->db.db_object == DMU_META_DNODE_OBJECT) { dr = db->db_data_pending; /* * It should only be modified in syncing context, so * make sure we only have one copy of the data. */ ASSERT(dr == NULL || dr->dt.dl.dr_data == db->db_buf); } /* verify db->db_blkptr */ if (db->db_blkptr) { if (db->db_parent == dn->dn_dbuf) { /* db is pointed to by the dnode */ /* ASSERT3U(db->db_blkid, <, dn->dn_nblkptr); */ if (DMU_OBJECT_IS_SPECIAL(db->db.db_object)) ASSERT(db->db_parent == NULL); else ASSERT(db->db_parent != NULL); if (db->db_blkid != DMU_SPILL_BLKID) ASSERT3P(db->db_blkptr, ==, &dn->dn_phys->dn_blkptr[db->db_blkid]); } else { /* db is pointed to by an indirect block */ int epb __maybe_unused = db->db_parent->db.db_size >> SPA_BLKPTRSHIFT; ASSERT3U(db->db_parent->db_level, ==, db->db_level+1); ASSERT3U(db->db_parent->db.db_object, ==, db->db.db_object); /* * dnode_grow_indblksz() can make this fail if we don't * have the parent's rwlock. XXX indblksz no longer * grows. safe to do this now? */ if (RW_LOCK_HELD(&db->db_parent->db_rwlock)) { ASSERT3P(db->db_blkptr, ==, ((blkptr_t *)db->db_parent->db.db_data + db->db_blkid % epb)); } } } if ((db->db_blkptr == NULL || BP_IS_HOLE(db->db_blkptr)) && (db->db_buf == NULL || db->db_buf->b_data) && db->db.db_data && db->db_blkid != DMU_BONUS_BLKID && db->db_state != DB_FILL && !dn->dn_free_txg) { /* * If the blkptr isn't set but they have nonzero data, * it had better be dirty, otherwise we'll lose that * data when we evict this buffer. * * There is an exception to this rule for indirect blocks; in * this case, if the indirect block is a hole, we fill in a few * fields on each of the child blocks (importantly, birth time) * to prevent hole birth times from being lost when you * partially fill in a hole. */ if (db->db_dirtycnt == 0) { if (db->db_level == 0) { uint64_t *buf = db->db.db_data; int i; for (i = 0; i < db->db.db_size >> 3; i++) { ASSERT(buf[i] == 0); } } else { blkptr_t *bps = db->db.db_data; ASSERT3U(1 << DB_DNODE(db)->dn_indblkshift, ==, db->db.db_size); /* * We want to verify that all the blkptrs in the * indirect block are holes, but we may have * automatically set up a few fields for them. * We iterate through each blkptr and verify * they only have those fields set. */ for (int i = 0; i < db->db.db_size / sizeof (blkptr_t); i++) { blkptr_t *bp = &bps[i]; ASSERT(ZIO_CHECKSUM_IS_ZERO( &bp->blk_cksum)); ASSERT( DVA_IS_EMPTY(&bp->blk_dva[0]) && DVA_IS_EMPTY(&bp->blk_dva[1]) && DVA_IS_EMPTY(&bp->blk_dva[2])); ASSERT0(bp->blk_fill); ASSERT0(bp->blk_pad[0]); ASSERT0(bp->blk_pad[1]); ASSERT(!BP_IS_EMBEDDED(bp)); ASSERT(BP_IS_HOLE(bp)); ASSERT0(bp->blk_phys_birth); } } } } DB_DNODE_EXIT(db); } #endif static void dbuf_clear_data(dmu_buf_impl_t *db) { ASSERT(MUTEX_HELD(&db->db_mtx)); dbuf_evict_user(db); ASSERT3P(db->db_buf, ==, NULL); db->db.db_data = NULL; if (db->db_state != DB_NOFILL) { db->db_state = DB_UNCACHED; DTRACE_SET_STATE(db, "clear data"); } } static void dbuf_set_data(dmu_buf_impl_t *db, arc_buf_t *buf) { ASSERT(MUTEX_HELD(&db->db_mtx)); ASSERT(buf != NULL); db->db_buf = buf; ASSERT(buf->b_data != NULL); db->db.db_data = buf->b_data; } static arc_buf_t * dbuf_alloc_arcbuf_from_arcbuf(dmu_buf_impl_t *db, arc_buf_t *data) { objset_t *os = db->db_objset; spa_t *spa = os->os_spa; arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db); enum zio_compress compress_type; uint8_t complevel; int psize, lsize; psize = arc_buf_size(data); lsize = arc_buf_lsize(data); compress_type = arc_get_compression(data); complevel = arc_get_complevel(data); if (arc_is_encrypted(data)) { boolean_t byteorder; uint8_t salt[ZIO_DATA_SALT_LEN]; uint8_t iv[ZIO_DATA_IV_LEN]; uint8_t mac[ZIO_DATA_MAC_LEN]; dnode_t *dn = DB_DNODE(db); arc_get_raw_params(data, &byteorder, salt, iv, mac); data = arc_alloc_raw_buf(spa, db, dmu_objset_id(os), byteorder, salt, iv, mac, dn->dn_type, psize, lsize, compress_type, complevel); } else if (compress_type != ZIO_COMPRESS_OFF) { ASSERT3U(type, ==, ARC_BUFC_DATA); data = arc_alloc_compressed_buf(spa, db, psize, lsize, compress_type, complevel); } else { data = arc_alloc_buf(spa, db, type, psize); } return (data); } static arc_buf_t * dbuf_alloc_arcbuf(dmu_buf_impl_t *db) { spa_t *spa = db->db_objset->os_spa; return (arc_alloc_buf(spa, db, DBUF_GET_BUFC_TYPE(db), db->db.db_size)); } /* * Loan out an arc_buf for read. Return the loaned arc_buf. */ arc_buf_t * dbuf_loan_arcbuf(dmu_buf_impl_t *db) { arc_buf_t *abuf; ASSERT(db->db_blkid != DMU_BONUS_BLKID); mutex_enter(&db->db_mtx); if (arc_released(db->db_buf) || zfs_refcount_count(&db->db_holds) > 1) { int blksz = db->db.db_size; spa_t *spa = db->db_objset->os_spa; mutex_exit(&db->db_mtx); abuf = arc_loan_buf(spa, B_FALSE, blksz); bcopy(db->db.db_data, abuf->b_data, blksz); } else { abuf = db->db_buf; arc_loan_inuse_buf(abuf, db); db->db_buf = NULL; dbuf_clear_data(db); mutex_exit(&db->db_mtx); } return (abuf); } /* * Calculate which level n block references the data at the level 0 offset * provided. */ uint64_t dbuf_whichblock(const dnode_t *dn, const int64_t level, const uint64_t offset) { if (dn->dn_datablkshift != 0 && dn->dn_indblkshift != 0) { /* * The level n blkid is equal to the level 0 blkid divided by * the number of level 0s in a level n block. * * The level 0 blkid is offset >> datablkshift = * offset / 2^datablkshift. * * The number of level 0s in a level n is the number of block * pointers in an indirect block, raised to the power of level. * This is 2^(indblkshift - SPA_BLKPTRSHIFT)^level = * 2^(level*(indblkshift - SPA_BLKPTRSHIFT)). * * Thus, the level n blkid is: offset / * ((2^datablkshift)*(2^(level*(indblkshift-SPA_BLKPTRSHIFT)))) * = offset / 2^(datablkshift + level * * (indblkshift - SPA_BLKPTRSHIFT)) * = offset >> (datablkshift + level * * (indblkshift - SPA_BLKPTRSHIFT)) */ const unsigned exp = dn->dn_datablkshift + level * (dn->dn_indblkshift - SPA_BLKPTRSHIFT); if (exp >= 8 * sizeof (offset)) { /* This only happens on the highest indirection level */ ASSERT3U(level, ==, dn->dn_nlevels - 1); return (0); } ASSERT3U(exp, <, 8 * sizeof (offset)); return (offset >> exp); } else { ASSERT3U(offset, <, dn->dn_datablksz); return (0); } } /* * This function is used to lock the parent of the provided dbuf. This should be * used when modifying or reading db_blkptr. */ db_lock_type_t dmu_buf_lock_parent(dmu_buf_impl_t *db, krw_t rw, void *tag) { enum db_lock_type ret = DLT_NONE; if (db->db_parent != NULL) { rw_enter(&db->db_parent->db_rwlock, rw); ret = DLT_PARENT; } else if (dmu_objset_ds(db->db_objset) != NULL) { rrw_enter(&dmu_objset_ds(db->db_objset)->ds_bp_rwlock, rw, tag); ret = DLT_OBJSET; } /* * We only return a DLT_NONE lock when it's the top-most indirect block * of the meta-dnode of the MOS. */ return (ret); } /* * We need to pass the lock type in because it's possible that the block will * move from being the topmost indirect block in a dnode (and thus, have no * parent) to not the top-most via an indirection increase. This would cause a * panic if we didn't pass the lock type in. */ void dmu_buf_unlock_parent(dmu_buf_impl_t *db, db_lock_type_t type, void *tag) { if (type == DLT_PARENT) rw_exit(&db->db_parent->db_rwlock); else if (type == DLT_OBJSET) rrw_exit(&dmu_objset_ds(db->db_objset)->ds_bp_rwlock, tag); } static void dbuf_read_done(zio_t *zio, const zbookmark_phys_t *zb, const blkptr_t *bp, arc_buf_t *buf, void *vdb) { dmu_buf_impl_t *db = vdb; mutex_enter(&db->db_mtx); ASSERT3U(db->db_state, ==, DB_READ); /* * All reads are synchronous, so we must have a hold on the dbuf */ ASSERT(zfs_refcount_count(&db->db_holds) > 0); ASSERT(db->db_buf == NULL); ASSERT(db->db.db_data == NULL); if (buf == NULL) { /* i/o error */ ASSERT(zio == NULL || zio->io_error != 0); ASSERT(db->db_blkid != DMU_BONUS_BLKID); ASSERT3P(db->db_buf, ==, NULL); db->db_state = DB_UNCACHED; DTRACE_SET_STATE(db, "i/o error"); } else if (db->db_level == 0 && db->db_freed_in_flight) { /* freed in flight */ ASSERT(zio == NULL || zio->io_error == 0); arc_release(buf, db); bzero(buf->b_data, db->db.db_size); arc_buf_freeze(buf); db->db_freed_in_flight = FALSE; dbuf_set_data(db, buf); db->db_state = DB_CACHED; DTRACE_SET_STATE(db, "freed in flight"); } else { /* success */ ASSERT(zio == NULL || zio->io_error == 0); dbuf_set_data(db, buf); db->db_state = DB_CACHED; DTRACE_SET_STATE(db, "successful read"); } cv_broadcast(&db->db_changed); dbuf_rele_and_unlock(db, NULL, B_FALSE); } /* * Shortcut for performing reads on bonus dbufs. Returns * an error if we fail to verify the dnode associated with * a decrypted block. Otherwise success. */ static int dbuf_read_bonus(dmu_buf_impl_t *db, dnode_t *dn, uint32_t flags) { int bonuslen, max_bonuslen, err; err = dbuf_read_verify_dnode_crypt(db, flags); if (err) return (err); bonuslen = MIN(dn->dn_bonuslen, dn->dn_phys->dn_bonuslen); max_bonuslen = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots); ASSERT(MUTEX_HELD(&db->db_mtx)); ASSERT(DB_DNODE_HELD(db)); ASSERT3U(bonuslen, <=, db->db.db_size); db->db.db_data = kmem_alloc(max_bonuslen, KM_SLEEP); arc_space_consume(max_bonuslen, ARC_SPACE_BONUS); if (bonuslen < max_bonuslen) bzero(db->db.db_data, max_bonuslen); if (bonuslen) bcopy(DN_BONUS(dn->dn_phys), db->db.db_data, bonuslen); db->db_state = DB_CACHED; DTRACE_SET_STATE(db, "bonus buffer filled"); return (0); } static void dbuf_handle_indirect_hole(dmu_buf_impl_t *db, dnode_t *dn) { blkptr_t *bps = db->db.db_data; uint32_t indbs = 1ULL << dn->dn_indblkshift; int n_bps = indbs >> SPA_BLKPTRSHIFT; for (int i = 0; i < n_bps; i++) { blkptr_t *bp = &bps[i]; ASSERT3U(BP_GET_LSIZE(db->db_blkptr), ==, indbs); BP_SET_LSIZE(bp, BP_GET_LEVEL(db->db_blkptr) == 1 ? dn->dn_datablksz : BP_GET_LSIZE(db->db_blkptr)); BP_SET_TYPE(bp, BP_GET_TYPE(db->db_blkptr)); BP_SET_LEVEL(bp, BP_GET_LEVEL(db->db_blkptr) - 1); BP_SET_BIRTH(bp, db->db_blkptr->blk_birth, 0); } } /* * Handle reads on dbufs that are holes, if necessary. This function * requires that the dbuf's mutex is held. Returns success (0) if action * was taken, ENOENT if no action was taken. */ static int dbuf_read_hole(dmu_buf_impl_t *db, dnode_t *dn, uint32_t flags) { ASSERT(MUTEX_HELD(&db->db_mtx)); int is_hole = db->db_blkptr == NULL || BP_IS_HOLE(db->db_blkptr); /* * For level 0 blocks only, if the above check fails: * Recheck BP_IS_HOLE() after dnode_block_freed() in case dnode_sync() * processes the delete record and clears the bp while we are waiting * for the dn_mtx (resulting in a "no" from block_freed). */ if (!is_hole && db->db_level == 0) { is_hole = dnode_block_freed(dn, db->db_blkid) || BP_IS_HOLE(db->db_blkptr); } if (is_hole) { dbuf_set_data(db, dbuf_alloc_arcbuf(db)); bzero(db->db.db_data, db->db.db_size); if (db->db_blkptr != NULL && db->db_level > 0 && BP_IS_HOLE(db->db_blkptr) && db->db_blkptr->blk_birth != 0) { dbuf_handle_indirect_hole(db, dn); } db->db_state = DB_CACHED; DTRACE_SET_STATE(db, "hole read satisfied"); return (0); } return (ENOENT); } /* * This function ensures that, when doing a decrypting read of a block, * we make sure we have decrypted the dnode associated with it. We must do * this so that we ensure we are fully authenticating the checksum-of-MACs * tree from the root of the objset down to this block. Indirect blocks are * always verified against their secure checksum-of-MACs assuming that the * dnode containing them is correct. Now that we are doing a decrypting read, * we can be sure that the key is loaded and verify that assumption. This is * especially important considering that we always read encrypted dnode * blocks as raw data (without verifying their MACs) to start, and * decrypt / authenticate them when we need to read an encrypted bonus buffer. */ static int dbuf_read_verify_dnode_crypt(dmu_buf_impl_t *db, uint32_t flags) { int err = 0; objset_t *os = db->db_objset; arc_buf_t *dnode_abuf; dnode_t *dn; zbookmark_phys_t zb; ASSERT(MUTEX_HELD(&db->db_mtx)); if (!os->os_encrypted || os->os_raw_receive || (flags & DB_RF_NO_DECRYPT) != 0) return (0); DB_DNODE_ENTER(db); dn = DB_DNODE(db); dnode_abuf = (dn->dn_dbuf != NULL) ? dn->dn_dbuf->db_buf : NULL; if (dnode_abuf == NULL || !arc_is_encrypted(dnode_abuf)) { DB_DNODE_EXIT(db); return (0); } SET_BOOKMARK(&zb, dmu_objset_id(os), DMU_META_DNODE_OBJECT, 0, dn->dn_dbuf->db_blkid); err = arc_untransform(dnode_abuf, os->os_spa, &zb, B_TRUE); /* * An error code of EACCES tells us that the key is still not * available. This is ok if we are only reading authenticated * (and therefore non-encrypted) blocks. */ if (err == EACCES && ((db->db_blkid != DMU_BONUS_BLKID && !DMU_OT_IS_ENCRYPTED(dn->dn_type)) || (db->db_blkid == DMU_BONUS_BLKID && !DMU_OT_IS_ENCRYPTED(dn->dn_bonustype)))) err = 0; DB_DNODE_EXIT(db); return (err); } /* * Drops db_mtx and the parent lock specified by dblt and tag before * returning. */ static int dbuf_read_impl(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags, db_lock_type_t dblt, void *tag) { dnode_t *dn; zbookmark_phys_t zb; uint32_t aflags = ARC_FLAG_NOWAIT; int err, zio_flags; boolean_t bonus_read; err = zio_flags = 0; bonus_read = B_FALSE; DB_DNODE_ENTER(db); dn = DB_DNODE(db); ASSERT(!zfs_refcount_is_zero(&db->db_holds)); ASSERT(MUTEX_HELD(&db->db_mtx)); ASSERT(db->db_state == DB_UNCACHED); ASSERT(db->db_buf == NULL); ASSERT(db->db_parent == NULL || RW_LOCK_HELD(&db->db_parent->db_rwlock)); if (db->db_blkid == DMU_BONUS_BLKID) { err = dbuf_read_bonus(db, dn, flags); goto early_unlock; } err = dbuf_read_hole(db, dn, flags); if (err == 0) goto early_unlock; /* * Any attempt to read a redacted block should result in an error. This * will never happen under normal conditions, but can be useful for * debugging purposes. */ if (BP_IS_REDACTED(db->db_blkptr)) { ASSERT(dsl_dataset_feature_is_active( db->db_objset->os_dsl_dataset, SPA_FEATURE_REDACTED_DATASETS)); err = SET_ERROR(EIO); goto early_unlock; } SET_BOOKMARK(&zb, dmu_objset_id(db->db_objset), db->db.db_object, db->db_level, db->db_blkid); /* * All bps of an encrypted os should have the encryption bit set. * If this is not true it indicates tampering and we report an error. */ if (db->db_objset->os_encrypted && !BP_USES_CRYPT(db->db_blkptr)) { spa_log_error(db->db_objset->os_spa, &zb); zfs_panic_recover("unencrypted block in encrypted " "object set %llu", dmu_objset_id(db->db_objset)); err = SET_ERROR(EIO); goto early_unlock; } err = dbuf_read_verify_dnode_crypt(db, flags); if (err != 0) goto early_unlock; DB_DNODE_EXIT(db); db->db_state = DB_READ; DTRACE_SET_STATE(db, "read issued"); mutex_exit(&db->db_mtx); if (DBUF_IS_L2CACHEABLE(db)) aflags |= ARC_FLAG_L2CACHE; dbuf_add_ref(db, NULL); zio_flags = (flags & DB_RF_CANFAIL) ? ZIO_FLAG_CANFAIL : ZIO_FLAG_MUSTSUCCEED; if ((flags & DB_RF_NO_DECRYPT) && BP_IS_PROTECTED(db->db_blkptr)) zio_flags |= ZIO_FLAG_RAW; /* * The zio layer will copy the provided blkptr later, but we need to * do this now so that we can release the parent's rwlock. We have to * do that now so that if dbuf_read_done is called synchronously (on * an l1 cache hit) we don't acquire the db_mtx while holding the * parent's rwlock, which would be a lock ordering violation. */ blkptr_t bp = *db->db_blkptr; dmu_buf_unlock_parent(db, dblt, tag); (void) arc_read(zio, db->db_objset->os_spa, &bp, dbuf_read_done, db, ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); return (err); early_unlock: DB_DNODE_EXIT(db); mutex_exit(&db->db_mtx); dmu_buf_unlock_parent(db, dblt, tag); return (err); } /* * This is our just-in-time copy function. It makes a copy of buffers that * have been modified in a previous transaction group before we access them in * the current active group. * * This function is used in three places: when we are dirtying a buffer for the * first time in a txg, when we are freeing a range in a dnode that includes * this buffer, and when we are accessing a buffer which was received compressed * and later referenced in a WRITE_BYREF record. * * Note that when we are called from dbuf_free_range() we do not put a hold on * the buffer, we just traverse the active dbuf list for the dnode. */ static void dbuf_fix_old_data(dmu_buf_impl_t *db, uint64_t txg) { dbuf_dirty_record_t *dr = list_head(&db->db_dirty_records); ASSERT(MUTEX_HELD(&db->db_mtx)); ASSERT(db->db.db_data != NULL); ASSERT(db->db_level == 0); ASSERT(db->db.db_object != DMU_META_DNODE_OBJECT); if (dr == NULL || (dr->dt.dl.dr_data != ((db->db_blkid == DMU_BONUS_BLKID) ? db->db.db_data : db->db_buf))) return; /* * If the last dirty record for this dbuf has not yet synced * and its referencing the dbuf data, either: * reset the reference to point to a new copy, * or (if there a no active holders) * just null out the current db_data pointer. */ ASSERT3U(dr->dr_txg, >=, txg - 2); if (db->db_blkid == DMU_BONUS_BLKID) { dnode_t *dn = DB_DNODE(db); int bonuslen = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots); dr->dt.dl.dr_data = kmem_alloc(bonuslen, KM_SLEEP); arc_space_consume(bonuslen, ARC_SPACE_BONUS); bcopy(db->db.db_data, dr->dt.dl.dr_data, bonuslen); } else if (zfs_refcount_count(&db->db_holds) > db->db_dirtycnt) { arc_buf_t *buf = dbuf_alloc_arcbuf_from_arcbuf(db, db->db_buf); dr->dt.dl.dr_data = buf; bcopy(db->db.db_data, buf->b_data, arc_buf_size(buf)); } else { db->db_buf = NULL; dbuf_clear_data(db); } } int dbuf_read(dmu_buf_impl_t *db, zio_t *zio, uint32_t flags) { int err = 0; boolean_t prefetch; dnode_t *dn; /* * We don't have to hold the mutex to check db_state because it * can't be freed while we have a hold on the buffer. */ ASSERT(!zfs_refcount_is_zero(&db->db_holds)); if (db->db_state == DB_NOFILL) return (SET_ERROR(EIO)); DB_DNODE_ENTER(db); dn = DB_DNODE(db); prefetch = db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID && (flags & DB_RF_NOPREFETCH) == 0 && dn != NULL && DBUF_IS_CACHEABLE(db); mutex_enter(&db->db_mtx); if (db->db_state == DB_CACHED) { spa_t *spa = dn->dn_objset->os_spa; /* * Ensure that this block's dnode has been decrypted if * the caller has requested decrypted data. */ err = dbuf_read_verify_dnode_crypt(db, flags); /* * If the arc buf is compressed or encrypted and the caller * requested uncompressed data, we need to untransform it * before returning. We also call arc_untransform() on any * unauthenticated blocks, which will verify their MAC if * the key is now available. */ if (err == 0 && db->db_buf != NULL && (flags & DB_RF_NO_DECRYPT) == 0 && (arc_is_encrypted(db->db_buf) || arc_is_unauthenticated(db->db_buf) || arc_get_compression(db->db_buf) != ZIO_COMPRESS_OFF)) { zbookmark_phys_t zb; SET_BOOKMARK(&zb, dmu_objset_id(db->db_objset), db->db.db_object, db->db_level, db->db_blkid); dbuf_fix_old_data(db, spa_syncing_txg(spa)); err = arc_untransform(db->db_buf, spa, &zb, B_FALSE); dbuf_set_data(db, db->db_buf); } mutex_exit(&db->db_mtx); if (err == 0 && prefetch) { dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE, flags & DB_RF_HAVESTRUCT); } DB_DNODE_EXIT(db); DBUF_STAT_BUMP(hash_hits); } else if (db->db_state == DB_UNCACHED) { spa_t *spa = dn->dn_objset->os_spa; boolean_t need_wait = B_FALSE; db_lock_type_t dblt = dmu_buf_lock_parent(db, RW_READER, FTAG); if (zio == NULL && db->db_blkptr != NULL && !BP_IS_HOLE(db->db_blkptr)) { zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL); need_wait = B_TRUE; } err = dbuf_read_impl(db, zio, flags, dblt, FTAG); /* * dbuf_read_impl has dropped db_mtx and our parent's rwlock * for us */ if (!err && prefetch) { dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE, flags & DB_RF_HAVESTRUCT); } DB_DNODE_EXIT(db); DBUF_STAT_BUMP(hash_misses); /* * If we created a zio_root we must execute it to avoid * leaking it, even if it isn't attached to any work due * to an error in dbuf_read_impl(). */ if (need_wait) { if (err == 0) err = zio_wait(zio); else VERIFY0(zio_wait(zio)); } } else { /* * Another reader came in while the dbuf was in flight * between UNCACHED and CACHED. Either a writer will finish * writing the buffer (sending the dbuf to CACHED) or the * first reader's request will reach the read_done callback * and send the dbuf to CACHED. Otherwise, a failure * occurred and the dbuf went to UNCACHED. */ mutex_exit(&db->db_mtx); if (prefetch) { dmu_zfetch(&dn->dn_zfetch, db->db_blkid, 1, B_TRUE, flags & DB_RF_HAVESTRUCT); } DB_DNODE_EXIT(db); DBUF_STAT_BUMP(hash_misses); /* Skip the wait per the caller's request. */ if ((flags & DB_RF_NEVERWAIT) == 0) { mutex_enter(&db->db_mtx); while (db->db_state == DB_READ || db->db_state == DB_FILL) { ASSERT(db->db_state == DB_READ || (flags & DB_RF_HAVESTRUCT) == 0); DTRACE_PROBE2(blocked__read, dmu_buf_impl_t *, db, zio_t *, zio); cv_wait(&db->db_changed, &db->db_mtx); } if (db->db_state == DB_UNCACHED) err = SET_ERROR(EIO); mutex_exit(&db->db_mtx); } } return (err); } static void dbuf_noread(dmu_buf_impl_t *db) { ASSERT(!zfs_refcount_is_zero(&db->db_holds)); ASSERT(db->db_blkid != DMU_BONUS_BLKID); mutex_enter(&db->db_mtx); while (db->db_state == DB_READ || db->db_state == DB_FILL) cv_wait(&db->db_changed, &db->db_mtx); if (db->db_state == DB_UNCACHED) { ASSERT(db->db_buf == NULL); ASSERT(db->db.db_data == NULL); dbuf_set_data(db, dbuf_alloc_arcbuf(db)); db->db_state = DB_FILL; DTRACE_SET_STATE(db, "assigning filled buffer"); } else if (db->db_state == DB_NOFILL) { dbuf_clear_data(db); } else { ASSERT3U(db->db_state, ==, DB_CACHED); } mutex_exit(&db->db_mtx); } void dbuf_unoverride(dbuf_dirty_record_t *dr) { dmu_buf_impl_t *db = dr->dr_dbuf; blkptr_t *bp = &dr->dt.dl.dr_overridden_by; uint64_t txg = dr->dr_txg; ASSERT(MUTEX_HELD(&db->db_mtx)); /* * This assert is valid because dmu_sync() expects to be called by * a zilog's get_data while holding a range lock. This call only * comes from dbuf_dirty() callers who must also hold a range lock. */ ASSERT(dr->dt.dl.dr_override_state != DR_IN_DMU_SYNC); ASSERT(db->db_level == 0); if (db->db_blkid == DMU_BONUS_BLKID || dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN) return; ASSERT(db->db_data_pending != dr); /* free this block */ if (!BP_IS_HOLE(bp) && !dr->dt.dl.dr_nopwrite) zio_free(db->db_objset->os_spa, txg, bp); dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN; dr->dt.dl.dr_nopwrite = B_FALSE; dr->dt.dl.dr_has_raw_params = B_FALSE; /* * Release the already-written buffer, so we leave it in * a consistent dirty state. Note that all callers are * modifying the buffer, so they will immediately do * another (redundant) arc_release(). Therefore, leave * the buf thawed to save the effort of freezing & * immediately re-thawing it. */ arc_release(dr->dt.dl.dr_data, db); } /* * Evict (if its unreferenced) or clear (if its referenced) any level-0 * data blocks in the free range, so that any future readers will find * empty blocks. */ void dbuf_free_range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid, dmu_tx_t *tx) { dmu_buf_impl_t *db_search; dmu_buf_impl_t *db, *db_next; uint64_t txg = tx->tx_txg; avl_index_t where; dbuf_dirty_record_t *dr; if (end_blkid > dn->dn_maxblkid && !(start_blkid == DMU_SPILL_BLKID || end_blkid == DMU_SPILL_BLKID)) end_blkid = dn->dn_maxblkid; dprintf_dnode(dn, "start=%llu end=%llu\n", start_blkid, end_blkid); db_search = kmem_alloc(sizeof (dmu_buf_impl_t), KM_SLEEP); db_search->db_level = 0; db_search->db_blkid = start_blkid; db_search->db_state = DB_SEARCH; mutex_enter(&dn->dn_dbufs_mtx); db = avl_find(&dn->dn_dbufs, db_search, &where); ASSERT3P(db, ==, NULL); db = avl_nearest(&dn->dn_dbufs, where, AVL_AFTER); for (; db != NULL; db = db_next) { db_next = AVL_NEXT(&dn->dn_dbufs, db); ASSERT(db->db_blkid != DMU_BONUS_BLKID); if (db->db_level != 0 || db->db_blkid > end_blkid) { break; } ASSERT3U(db->db_blkid, >=, start_blkid); /* found a level 0 buffer in the range */ mutex_enter(&db->db_mtx); if (dbuf_undirty(db, tx)) { /* mutex has been dropped and dbuf destroyed */ continue; } if (db->db_state == DB_UNCACHED || db->db_state == DB_NOFILL || db->db_state == DB_EVICTING) { ASSERT(db->db.db_data == NULL); mutex_exit(&db->db_mtx); continue; } if (db->db_state == DB_READ || db->db_state == DB_FILL) { /* will be handled in dbuf_read_done or dbuf_rele */ db->db_freed_in_flight = TRUE; mutex_exit(&db->db_mtx); continue; } if (zfs_refcount_count(&db->db_holds) == 0) { ASSERT(db->db_buf); dbuf_destroy(db); continue; } /* The dbuf is referenced */ dr = list_head(&db->db_dirty_records); if (dr != NULL) { if (dr->dr_txg == txg) { /* * This buffer is "in-use", re-adjust the file * size to reflect that this buffer may * contain new data when we sync. */ if (db->db_blkid != DMU_SPILL_BLKID && db->db_blkid > dn->dn_maxblkid) dn->dn_maxblkid = db->db_blkid; dbuf_unoverride(dr); } else { /* * This dbuf is not dirty in the open context. * Either uncache it (if its not referenced in * the open context) or reset its contents to * empty. */ dbuf_fix_old_data(db, txg); } } /* clear the contents if its cached */ if (db->db_state == DB_CACHED) { ASSERT(db->db.db_data != NULL); arc_release(db->db_buf, db); rw_enter(&db->db_rwlock, RW_WRITER); bzero(db->db.db_data, db->db.db_size); rw_exit(&db->db_rwlock); arc_buf_freeze(db->db_buf); } mutex_exit(&db->db_mtx); } kmem_free(db_search, sizeof (dmu_buf_impl_t)); mutex_exit(&dn->dn_dbufs_mtx); } void dbuf_new_size(dmu_buf_impl_t *db, int size, dmu_tx_t *tx) { arc_buf_t *buf, *old_buf; dbuf_dirty_record_t *dr; int osize = db->db.db_size; arc_buf_contents_t type = DBUF_GET_BUFC_TYPE(db); dnode_t *dn; ASSERT(db->db_blkid != DMU_BONUS_BLKID); DB_DNODE_ENTER(db); dn = DB_DNODE(db); /* * XXX we should be doing a dbuf_read, checking the return * value and returning that up to our callers */ dmu_buf_will_dirty(&db->db, tx); /* create the data buffer for the new block */ buf = arc_alloc_buf(dn->dn_objset->os_spa, db, type, size); /* copy old block data to the new block */ old_buf = db->db_buf; bcopy(old_buf->b_data, buf->b_data, MIN(osize, size)); /* zero the remainder */ if (size > osize) bzero((uint8_t *)buf->b_data + osize, size - osize); mutex_enter(&db->db_mtx); dbuf_set_data(db, buf); arc_buf_destroy(old_buf, db); db->db.db_size = size; dr = list_head(&db->db_dirty_records); /* dirty record added by dmu_buf_will_dirty() */ VERIFY(dr != NULL); if (db->db_level == 0) dr->dt.dl.dr_data = buf; ASSERT3U(dr->dr_txg, ==, tx->tx_txg); ASSERT3U(dr->dr_accounted, ==, osize); dr->dr_accounted = size; mutex_exit(&db->db_mtx); dmu_objset_willuse_space(dn->dn_objset, size - osize, tx); DB_DNODE_EXIT(db); } void dbuf_release_bp(dmu_buf_impl_t *db) { objset_t *os __maybe_unused = db->db_objset; ASSERT(dsl_pool_sync_context(dmu_objset_pool(os))); ASSERT(arc_released(os->os_phys_buf) || list_link_active(&os->os_dsl_dataset->ds_synced_link)); ASSERT(db->db_parent == NULL || arc_released(db->db_parent->db_buf)); (void) arc_release(db->db_buf, db); } /* * We already have a dirty record for this TXG, and we are being * dirtied again. */ static void dbuf_redirty(dbuf_dirty_record_t *dr) { dmu_buf_impl_t *db = dr->dr_dbuf; ASSERT(MUTEX_HELD(&db->db_mtx)); if (db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID) { /* * If this buffer has already been written out, * we now need to reset its state. */ dbuf_unoverride(dr); if (db->db.db_object != DMU_META_DNODE_OBJECT && db->db_state != DB_NOFILL) { /* Already released on initial dirty, so just thaw. */ ASSERT(arc_released(db->db_buf)); arc_buf_thaw(db->db_buf); } } } dbuf_dirty_record_t * dbuf_dirty_lightweight(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx) { rw_enter(&dn->dn_struct_rwlock, RW_READER); IMPLY(dn->dn_objset->os_raw_receive, dn->dn_maxblkid >= blkid); dnode_new_blkid(dn, blkid, tx, B_TRUE, B_FALSE); ASSERT(dn->dn_maxblkid >= blkid); dbuf_dirty_record_t *dr = kmem_zalloc(sizeof (*dr), KM_SLEEP); list_link_init(&dr->dr_dirty_node); list_link_init(&dr->dr_dbuf_node); dr->dr_dnode = dn; dr->dr_txg = tx->tx_txg; dr->dt.dll.dr_blkid = blkid; dr->dr_accounted = dn->dn_datablksz; /* * There should not be any dbuf for the block that we're dirtying. * Otherwise the buffer contents could be inconsistent between the * dbuf and the lightweight dirty record. */ ASSERT3P(NULL, ==, dbuf_find(dn->dn_objset, dn->dn_object, 0, blkid)); mutex_enter(&dn->dn_mtx); int txgoff = tx->tx_txg & TXG_MASK; if (dn->dn_free_ranges[txgoff] != NULL) { range_tree_clear(dn->dn_free_ranges[txgoff], blkid, 1); } if (dn->dn_nlevels == 1) { ASSERT3U(blkid, <, dn->dn_nblkptr); list_insert_tail(&dn->dn_dirty_records[txgoff], dr); mutex_exit(&dn->dn_mtx); rw_exit(&dn->dn_struct_rwlock); dnode_setdirty(dn, tx); } else { mutex_exit(&dn->dn_mtx); int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; dmu_buf_impl_t *parent_db = dbuf_hold_level(dn, 1, blkid >> epbs, FTAG); rw_exit(&dn->dn_struct_rwlock); if (parent_db == NULL) { kmem_free(dr, sizeof (*dr)); return (NULL); } int err = dbuf_read(parent_db, NULL, (DB_RF_NOPREFETCH | DB_RF_CANFAIL)); if (err != 0) { dbuf_rele(parent_db, FTAG); kmem_free(dr, sizeof (*dr)); return (NULL); } dbuf_dirty_record_t *parent_dr = dbuf_dirty(parent_db, tx); dbuf_rele(parent_db, FTAG); mutex_enter(&parent_dr->dt.di.dr_mtx); ASSERT3U(parent_dr->dr_txg, ==, tx->tx_txg); list_insert_tail(&parent_dr->dt.di.dr_children, dr); mutex_exit(&parent_dr->dt.di.dr_mtx); dr->dr_parent = parent_dr; } dmu_objset_willuse_space(dn->dn_objset, dr->dr_accounted, tx); return (dr); } dbuf_dirty_record_t * dbuf_dirty(dmu_buf_impl_t *db, dmu_tx_t *tx) { dnode_t *dn; objset_t *os; dbuf_dirty_record_t *dr, *dr_next, *dr_head; int txgoff = tx->tx_txg & TXG_MASK; boolean_t drop_struct_rwlock = B_FALSE; ASSERT(tx->tx_txg != 0); ASSERT(!zfs_refcount_is_zero(&db->db_holds)); DMU_TX_DIRTY_BUF(tx, db); DB_DNODE_ENTER(db); dn = DB_DNODE(db); /* * Shouldn't dirty a regular buffer in syncing context. Private * objects may be dirtied in syncing context, but only if they * were already pre-dirtied in open context. */ #ifdef ZFS_DEBUG if (dn->dn_objset->os_dsl_dataset != NULL) { rrw_enter(&dn->dn_objset->os_dsl_dataset->ds_bp_rwlock, RW_READER, FTAG); } ASSERT(!dmu_tx_is_syncing(tx) || BP_IS_HOLE(dn->dn_objset->os_rootbp) || DMU_OBJECT_IS_SPECIAL(dn->dn_object) || dn->dn_objset->os_dsl_dataset == NULL); if (dn->dn_objset->os_dsl_dataset != NULL) rrw_exit(&dn->dn_objset->os_dsl_dataset->ds_bp_rwlock, FTAG); #endif /* * We make this assert for private objects as well, but after we * check if we're already dirty. They are allowed to re-dirty * in syncing context. */ ASSERT(dn->dn_object == DMU_META_DNODE_OBJECT || dn->dn_dirtyctx == DN_UNDIRTIED || dn->dn_dirtyctx == (dmu_tx_is_syncing(tx) ? DN_DIRTY_SYNC : DN_DIRTY_OPEN)); mutex_enter(&db->db_mtx); /* * XXX make this true for indirects too? The problem is that * transactions created with dmu_tx_create_assigned() from * syncing context don't bother holding ahead. */ ASSERT(db->db_level != 0 || db->db_state == DB_CACHED || db->db_state == DB_FILL || db->db_state == DB_NOFILL); mutex_enter(&dn->dn_mtx); dnode_set_dirtyctx(dn, tx, db); if (tx->tx_txg > dn->dn_dirty_txg) dn->dn_dirty_txg = tx->tx_txg; mutex_exit(&dn->dn_mtx); if (db->db_blkid == DMU_SPILL_BLKID) dn->dn_have_spill = B_TRUE; /* * If this buffer is already dirty, we're done. */ dr_head = list_head(&db->db_dirty_records); ASSERT(dr_head == NULL || dr_head->dr_txg <= tx->tx_txg || db->db.db_object == DMU_META_DNODE_OBJECT); dr_next = dbuf_find_dirty_lte(db, tx->tx_txg); if (dr_next && dr_next->dr_txg == tx->tx_txg) { DB_DNODE_EXIT(db); dbuf_redirty(dr_next); mutex_exit(&db->db_mtx); return (dr_next); } /* * Only valid if not already dirty. */ ASSERT(dn->dn_object == 0 || dn->dn_dirtyctx == DN_UNDIRTIED || dn->dn_dirtyctx == (dmu_tx_is_syncing(tx) ? DN_DIRTY_SYNC : DN_DIRTY_OPEN)); ASSERT3U(dn->dn_nlevels, >, db->db_level); /* * We should only be dirtying in syncing context if it's the * mos or we're initializing the os or it's a special object. * However, we are allowed to dirty in syncing context provided * we already dirtied it in open context. Hence we must make * this assertion only if we're not already dirty. */ os = dn->dn_objset; VERIFY3U(tx->tx_txg, <=, spa_final_dirty_txg(os->os_spa)); #ifdef ZFS_DEBUG if (dn->dn_objset->os_dsl_dataset != NULL) rrw_enter(&os->os_dsl_dataset->ds_bp_rwlock, RW_READER, FTAG); ASSERT(!dmu_tx_is_syncing(tx) || DMU_OBJECT_IS_SPECIAL(dn->dn_object) || os->os_dsl_dataset == NULL || BP_IS_HOLE(os->os_rootbp)); if (dn->dn_objset->os_dsl_dataset != NULL) rrw_exit(&os->os_dsl_dataset->ds_bp_rwlock, FTAG); #endif ASSERT(db->db.db_size != 0); dprintf_dbuf(db, "size=%llx\n", (u_longlong_t)db->db.db_size); if (db->db_blkid != DMU_BONUS_BLKID) { dmu_objset_willuse_space(os, db->db.db_size, tx); } /* * If this buffer is dirty in an old transaction group we need * to make a copy of it so that the changes we make in this * transaction group won't leak out when we sync the older txg. */ dr = kmem_zalloc(sizeof (dbuf_dirty_record_t), KM_SLEEP); list_link_init(&dr->dr_dirty_node); list_link_init(&dr->dr_dbuf_node); dr->dr_dnode = dn; if (db->db_level == 0) { void *data_old = db->db_buf; if (db->db_state != DB_NOFILL) { if (db->db_blkid == DMU_BONUS_BLKID) { dbuf_fix_old_data(db, tx->tx_txg); data_old = db->db.db_data; } else if (db->db.db_object != DMU_META_DNODE_OBJECT) { /* * Release the data buffer from the cache so * that we can modify it without impacting * possible other users of this cached data * block. Note that indirect blocks and * private objects are not released until the * syncing state (since they are only modified * then). */ arc_release(db->db_buf, db); dbuf_fix_old_data(db, tx->tx_txg); data_old = db->db_buf; } ASSERT(data_old != NULL); } dr->dt.dl.dr_data = data_old; } else { mutex_init(&dr->dt.di.dr_mtx, NULL, MUTEX_NOLOCKDEP, NULL); list_create(&dr->dt.di.dr_children, sizeof (dbuf_dirty_record_t), offsetof(dbuf_dirty_record_t, dr_dirty_node)); } if (db->db_blkid != DMU_BONUS_BLKID) dr->dr_accounted = db->db.db_size; dr->dr_dbuf = db; dr->dr_txg = tx->tx_txg; list_insert_before(&db->db_dirty_records, dr_next, dr); /* * We could have been freed_in_flight between the dbuf_noread * and dbuf_dirty. We win, as though the dbuf_noread() had * happened after the free. */ if (db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID && db->db_blkid != DMU_SPILL_BLKID) { mutex_enter(&dn->dn_mtx); if (dn->dn_free_ranges[txgoff] != NULL) { range_tree_clear(dn->dn_free_ranges[txgoff], db->db_blkid, 1); } mutex_exit(&dn->dn_mtx); db->db_freed_in_flight = FALSE; } /* * This buffer is now part of this txg */ dbuf_add_ref(db, (void *)(uintptr_t)tx->tx_txg); db->db_dirtycnt += 1; ASSERT3U(db->db_dirtycnt, <=, 3); mutex_exit(&db->db_mtx); if (db->db_blkid == DMU_BONUS_BLKID || db->db_blkid == DMU_SPILL_BLKID) { mutex_enter(&dn->dn_mtx); ASSERT(!list_link_active(&dr->dr_dirty_node)); list_insert_tail(&dn->dn_dirty_records[txgoff], dr); mutex_exit(&dn->dn_mtx); dnode_setdirty(dn, tx); DB_DNODE_EXIT(db); return (dr); } if (!RW_WRITE_HELD(&dn->dn_struct_rwlock)) { rw_enter(&dn->dn_struct_rwlock, RW_READER); drop_struct_rwlock = B_TRUE; } /* * If we are overwriting a dedup BP, then unless it is snapshotted, * when we get to syncing context we will need to decrement its * refcount in the DDT. Prefetch the relevant DDT block so that * syncing context won't have to wait for the i/o. */ if (db->db_blkptr != NULL) { db_lock_type_t dblt = dmu_buf_lock_parent(db, RW_READER, FTAG); ddt_prefetch(os->os_spa, db->db_blkptr); dmu_buf_unlock_parent(db, dblt, FTAG); } /* * We need to hold the dn_struct_rwlock to make this assertion, * because it protects dn_phys / dn_next_nlevels from changing. */ ASSERT((dn->dn_phys->dn_nlevels == 0 && db->db_level == 0) || dn->dn_phys->dn_nlevels > db->db_level || dn->dn_next_nlevels[txgoff] > db->db_level || dn->dn_next_nlevels[(tx->tx_txg-1) & TXG_MASK] > db->db_level || dn->dn_next_nlevels[(tx->tx_txg-2) & TXG_MASK] > db->db_level); if (db->db_level == 0) { ASSERT(!db->db_objset->os_raw_receive || dn->dn_maxblkid >= db->db_blkid); dnode_new_blkid(dn, db->db_blkid, tx, drop_struct_rwlock, B_FALSE); ASSERT(dn->dn_maxblkid >= db->db_blkid); } if (db->db_level+1 < dn->dn_nlevels) { dmu_buf_impl_t *parent = db->db_parent; dbuf_dirty_record_t *di; int parent_held = FALSE; if (db->db_parent == NULL || db->db_parent == dn->dn_dbuf) { int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; parent = dbuf_hold_level(dn, db->db_level + 1, db->db_blkid >> epbs, FTAG); ASSERT(parent != NULL); parent_held = TRUE; } if (drop_struct_rwlock) rw_exit(&dn->dn_struct_rwlock); ASSERT3U(db->db_level + 1, ==, parent->db_level); di = dbuf_dirty(parent, tx); if (parent_held) dbuf_rele(parent, FTAG); mutex_enter(&db->db_mtx); /* * Since we've dropped the mutex, it's possible that * dbuf_undirty() might have changed this out from under us. */ if (list_head(&db->db_dirty_records) == dr || dn->dn_object == DMU_META_DNODE_OBJECT) { mutex_enter(&di->dt.di.dr_mtx); ASSERT3U(di->dr_txg, ==, tx->tx_txg); ASSERT(!list_link_active(&dr->dr_dirty_node)); list_insert_tail(&di->dt.di.dr_children, dr); mutex_exit(&di->dt.di.dr_mtx); dr->dr_parent = di; } mutex_exit(&db->db_mtx); } else { ASSERT(db->db_level + 1 == dn->dn_nlevels); ASSERT(db->db_blkid < dn->dn_nblkptr); ASSERT(db->db_parent == NULL || db->db_parent == dn->dn_dbuf); mutex_enter(&dn->dn_mtx); ASSERT(!list_link_active(&dr->dr_dirty_node)); list_insert_tail(&dn->dn_dirty_records[txgoff], dr); mutex_exit(&dn->dn_mtx); if (drop_struct_rwlock) rw_exit(&dn->dn_struct_rwlock); } dnode_setdirty(dn, tx); DB_DNODE_EXIT(db); return (dr); } static void dbuf_undirty_bonus(dbuf_dirty_record_t *dr) { dmu_buf_impl_t *db = dr->dr_dbuf; if (dr->dt.dl.dr_data != db->db.db_data) { struct dnode *dn = dr->dr_dnode; int max_bonuslen = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots); kmem_free(dr->dt.dl.dr_data, max_bonuslen); arc_space_return(max_bonuslen, ARC_SPACE_BONUS); } db->db_data_pending = NULL; ASSERT(list_next(&db->db_dirty_records, dr) == NULL); list_remove(&db->db_dirty_records, dr); if (dr->dr_dbuf->db_level != 0) { mutex_destroy(&dr->dt.di.dr_mtx); list_destroy(&dr->dt.di.dr_children); } kmem_free(dr, sizeof (dbuf_dirty_record_t)); ASSERT3U(db->db_dirtycnt, >, 0); db->db_dirtycnt -= 1; } /* * Undirty a buffer in the transaction group referenced by the given * transaction. Return whether this evicted the dbuf. */ static boolean_t dbuf_undirty(dmu_buf_impl_t *db, dmu_tx_t *tx) { uint64_t txg = tx->tx_txg; ASSERT(txg != 0); /* * Due to our use of dn_nlevels below, this can only be called * in open context, unless we are operating on the MOS. * From syncing context, dn_nlevels may be different from the * dn_nlevels used when dbuf was dirtied. */ ASSERT(db->db_objset == dmu_objset_pool(db->db_objset)->dp_meta_objset || txg != spa_syncing_txg(dmu_objset_spa(db->db_objset))); ASSERT(db->db_blkid != DMU_BONUS_BLKID); ASSERT0(db->db_level); ASSERT(MUTEX_HELD(&db->db_mtx)); /* * If this buffer is not dirty, we're done. */ dbuf_dirty_record_t *dr = dbuf_find_dirty_eq(db, txg); if (dr == NULL) return (B_FALSE); ASSERT(dr->dr_dbuf == db); dnode_t *dn = dr->dr_dnode; dprintf_dbuf(db, "size=%llx\n", (u_longlong_t)db->db.db_size); ASSERT(db->db.db_size != 0); dsl_pool_undirty_space(dmu_objset_pool(dn->dn_objset), dr->dr_accounted, txg); list_remove(&db->db_dirty_records, dr); /* * Note that there are three places in dbuf_dirty() * where this dirty record may be put on a list. * Make sure to do a list_remove corresponding to * every one of those list_insert calls. */ if (dr->dr_parent) { mutex_enter(&dr->dr_parent->dt.di.dr_mtx); list_remove(&dr->dr_parent->dt.di.dr_children, dr); mutex_exit(&dr->dr_parent->dt.di.dr_mtx); } else if (db->db_blkid == DMU_SPILL_BLKID || db->db_level + 1 == dn->dn_nlevels) { ASSERT(db->db_blkptr == NULL || db->db_parent == dn->dn_dbuf); mutex_enter(&dn->dn_mtx); list_remove(&dn->dn_dirty_records[txg & TXG_MASK], dr); mutex_exit(&dn->dn_mtx); } if (db->db_state != DB_NOFILL) { dbuf_unoverride(dr); ASSERT(db->db_buf != NULL); ASSERT(dr->dt.dl.dr_data != NULL); if (dr->dt.dl.dr_data != db->db_buf) arc_buf_destroy(dr->dt.dl.dr_data, db); } kmem_free(dr, sizeof (dbuf_dirty_record_t)); ASSERT(db->db_dirtycnt > 0); db->db_dirtycnt -= 1; if (zfs_refcount_remove(&db->db_holds, (void *)(uintptr_t)txg) == 0) { ASSERT(db->db_state == DB_NOFILL || arc_released(db->db_buf)); dbuf_destroy(db); return (B_TRUE); } return (B_FALSE); } static void dmu_buf_will_dirty_impl(dmu_buf_t *db_fake, int flags, dmu_tx_t *tx) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; ASSERT(tx->tx_txg != 0); ASSERT(!zfs_refcount_is_zero(&db->db_holds)); /* * Quick check for dirtiness. For already dirty blocks, this * reduces runtime of this function by >90%, and overall performance * by 50% for some workloads (e.g. file deletion with indirect blocks * cached). */ mutex_enter(&db->db_mtx); if (db->db_state == DB_CACHED) { dbuf_dirty_record_t *dr = dbuf_find_dirty_eq(db, tx->tx_txg); /* * It's possible that it is already dirty but not cached, * because there are some calls to dbuf_dirty() that don't * go through dmu_buf_will_dirty(). */ if (dr != NULL) { /* This dbuf is already dirty and cached. */ dbuf_redirty(dr); mutex_exit(&db->db_mtx); return; } } mutex_exit(&db->db_mtx); DB_DNODE_ENTER(db); if (RW_WRITE_HELD(&DB_DNODE(db)->dn_struct_rwlock)) flags |= DB_RF_HAVESTRUCT; DB_DNODE_EXIT(db); (void) dbuf_read(db, NULL, flags); (void) dbuf_dirty(db, tx); } void dmu_buf_will_dirty(dmu_buf_t *db_fake, dmu_tx_t *tx) { dmu_buf_will_dirty_impl(db_fake, DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH, tx); } boolean_t dmu_buf_is_dirty(dmu_buf_t *db_fake, dmu_tx_t *tx) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; dbuf_dirty_record_t *dr; mutex_enter(&db->db_mtx); dr = dbuf_find_dirty_eq(db, tx->tx_txg); mutex_exit(&db->db_mtx); return (dr != NULL); } void dmu_buf_will_not_fill(dmu_buf_t *db_fake, dmu_tx_t *tx) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; db->db_state = DB_NOFILL; DTRACE_SET_STATE(db, "allocating NOFILL buffer"); dmu_buf_will_fill(db_fake, tx); } void dmu_buf_will_fill(dmu_buf_t *db_fake, dmu_tx_t *tx) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; ASSERT(db->db_blkid != DMU_BONUS_BLKID); ASSERT(tx->tx_txg != 0); ASSERT(db->db_level == 0); ASSERT(!zfs_refcount_is_zero(&db->db_holds)); ASSERT(db->db.db_object != DMU_META_DNODE_OBJECT || dmu_tx_private_ok(tx)); dbuf_noread(db); (void) dbuf_dirty(db, tx); } /* * This function is effectively the same as dmu_buf_will_dirty(), but * indicates the caller expects raw encrypted data in the db, and provides * the crypt params (byteorder, salt, iv, mac) which should be stored in the * blkptr_t when this dbuf is written. This is only used for blocks of * dnodes, during raw receive. */ void dmu_buf_set_crypt_params(dmu_buf_t *db_fake, boolean_t byteorder, const uint8_t *salt, const uint8_t *iv, const uint8_t *mac, dmu_tx_t *tx) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; dbuf_dirty_record_t *dr; /* * dr_has_raw_params is only processed for blocks of dnodes * (see dbuf_sync_dnode_leaf_crypt()). */ ASSERT3U(db->db.db_object, ==, DMU_META_DNODE_OBJECT); ASSERT3U(db->db_level, ==, 0); ASSERT(db->db_objset->os_raw_receive); dmu_buf_will_dirty_impl(db_fake, DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH | DB_RF_NO_DECRYPT, tx); dr = dbuf_find_dirty_eq(db, tx->tx_txg); ASSERT3P(dr, !=, NULL); dr->dt.dl.dr_has_raw_params = B_TRUE; dr->dt.dl.dr_byteorder = byteorder; bcopy(salt, dr->dt.dl.dr_salt, ZIO_DATA_SALT_LEN); bcopy(iv, dr->dt.dl.dr_iv, ZIO_DATA_IV_LEN); bcopy(mac, dr->dt.dl.dr_mac, ZIO_DATA_MAC_LEN); } static void dbuf_override_impl(dmu_buf_impl_t *db, const blkptr_t *bp, dmu_tx_t *tx) { struct dirty_leaf *dl; dbuf_dirty_record_t *dr; dr = list_head(&db->db_dirty_records); ASSERT3U(dr->dr_txg, ==, tx->tx_txg); dl = &dr->dt.dl; dl->dr_overridden_by = *bp; dl->dr_override_state = DR_OVERRIDDEN; dl->dr_overridden_by.blk_birth = dr->dr_txg; } /* ARGSUSED */ void dmu_buf_fill_done(dmu_buf_t *dbuf, dmu_tx_t *tx) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbuf; dbuf_states_t old_state; mutex_enter(&db->db_mtx); DBUF_VERIFY(db); old_state = db->db_state; db->db_state = DB_CACHED; if (old_state == DB_FILL) { if (db->db_level == 0 && db->db_freed_in_flight) { ASSERT(db->db_blkid != DMU_BONUS_BLKID); /* we were freed while filling */ /* XXX dbuf_undirty? */ bzero(db->db.db_data, db->db.db_size); db->db_freed_in_flight = FALSE; DTRACE_SET_STATE(db, "fill done handling freed in flight"); } else { DTRACE_SET_STATE(db, "fill done"); } cv_broadcast(&db->db_changed); } mutex_exit(&db->db_mtx); } void dmu_buf_write_embedded(dmu_buf_t *dbuf, void *data, bp_embedded_type_t etype, enum zio_compress comp, int uncompressed_size, int compressed_size, int byteorder, dmu_tx_t *tx) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbuf; struct dirty_leaf *dl; dmu_object_type_t type; dbuf_dirty_record_t *dr; if (etype == BP_EMBEDDED_TYPE_DATA) { ASSERT(spa_feature_is_active(dmu_objset_spa(db->db_objset), SPA_FEATURE_EMBEDDED_DATA)); } DB_DNODE_ENTER(db); type = DB_DNODE(db)->dn_type; DB_DNODE_EXIT(db); ASSERT0(db->db_level); ASSERT(db->db_blkid != DMU_BONUS_BLKID); dmu_buf_will_not_fill(dbuf, tx); dr = list_head(&db->db_dirty_records); ASSERT3U(dr->dr_txg, ==, tx->tx_txg); dl = &dr->dt.dl; encode_embedded_bp_compressed(&dl->dr_overridden_by, data, comp, uncompressed_size, compressed_size); BPE_SET_ETYPE(&dl->dr_overridden_by, etype); BP_SET_TYPE(&dl->dr_overridden_by, type); BP_SET_LEVEL(&dl->dr_overridden_by, 0); BP_SET_BYTEORDER(&dl->dr_overridden_by, byteorder); dl->dr_override_state = DR_OVERRIDDEN; dl->dr_overridden_by.blk_birth = dr->dr_txg; } void dmu_buf_redact(dmu_buf_t *dbuf, dmu_tx_t *tx) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbuf; dmu_object_type_t type; ASSERT(dsl_dataset_feature_is_active(db->db_objset->os_dsl_dataset, SPA_FEATURE_REDACTED_DATASETS)); DB_DNODE_ENTER(db); type = DB_DNODE(db)->dn_type; DB_DNODE_EXIT(db); ASSERT0(db->db_level); dmu_buf_will_not_fill(dbuf, tx); blkptr_t bp = { { { {0} } } }; BP_SET_TYPE(&bp, type); BP_SET_LEVEL(&bp, 0); BP_SET_BIRTH(&bp, tx->tx_txg, 0); BP_SET_REDACTED(&bp); BPE_SET_LSIZE(&bp, dbuf->db_size); dbuf_override_impl(db, &bp, tx); } /* * Directly assign a provided arc buf to a given dbuf if it's not referenced * by anybody except our caller. Otherwise copy arcbuf's contents to dbuf. */ void dbuf_assign_arcbuf(dmu_buf_impl_t *db, arc_buf_t *buf, dmu_tx_t *tx) { ASSERT(!zfs_refcount_is_zero(&db->db_holds)); ASSERT(db->db_blkid != DMU_BONUS_BLKID); ASSERT(db->db_level == 0); ASSERT3U(dbuf_is_metadata(db), ==, arc_is_metadata(buf)); ASSERT(buf != NULL); ASSERT3U(arc_buf_lsize(buf), ==, db->db.db_size); ASSERT(tx->tx_txg != 0); arc_return_buf(buf, db); ASSERT(arc_released(buf)); mutex_enter(&db->db_mtx); while (db->db_state == DB_READ || db->db_state == DB_FILL) cv_wait(&db->db_changed, &db->db_mtx); ASSERT(db->db_state == DB_CACHED || db->db_state == DB_UNCACHED); if (db->db_state == DB_CACHED && zfs_refcount_count(&db->db_holds) - 1 > db->db_dirtycnt) { /* * In practice, we will never have a case where we have an * encrypted arc buffer while additional holds exist on the * dbuf. We don't handle this here so we simply assert that * fact instead. */ ASSERT(!arc_is_encrypted(buf)); mutex_exit(&db->db_mtx); (void) dbuf_dirty(db, tx); bcopy(buf->b_data, db->db.db_data, db->db.db_size); arc_buf_destroy(buf, db); return; } if (db->db_state == DB_CACHED) { dbuf_dirty_record_t *dr = list_head(&db->db_dirty_records); ASSERT(db->db_buf != NULL); if (dr != NULL && dr->dr_txg == tx->tx_txg) { ASSERT(dr->dt.dl.dr_data == db->db_buf); if (!arc_released(db->db_buf)) { ASSERT(dr->dt.dl.dr_override_state == DR_OVERRIDDEN); arc_release(db->db_buf, db); } dr->dt.dl.dr_data = buf; arc_buf_destroy(db->db_buf, db); } else if (dr == NULL || dr->dt.dl.dr_data != db->db_buf) { arc_release(db->db_buf, db); arc_buf_destroy(db->db_buf, db); } db->db_buf = NULL; } ASSERT(db->db_buf == NULL); dbuf_set_data(db, buf); db->db_state = DB_FILL; DTRACE_SET_STATE(db, "filling assigned arcbuf"); mutex_exit(&db->db_mtx); (void) dbuf_dirty(db, tx); dmu_buf_fill_done(&db->db, tx); } void dbuf_destroy(dmu_buf_impl_t *db) { dnode_t *dn; dmu_buf_impl_t *parent = db->db_parent; dmu_buf_impl_t *dndb; ASSERT(MUTEX_HELD(&db->db_mtx)); ASSERT(zfs_refcount_is_zero(&db->db_holds)); if (db->db_buf != NULL) { arc_buf_destroy(db->db_buf, db); db->db_buf = NULL; } if (db->db_blkid == DMU_BONUS_BLKID) { int slots = DB_DNODE(db)->dn_num_slots; int bonuslen = DN_SLOTS_TO_BONUSLEN(slots); if (db->db.db_data != NULL) { kmem_free(db->db.db_data, bonuslen); arc_space_return(bonuslen, ARC_SPACE_BONUS); db->db_state = DB_UNCACHED; DTRACE_SET_STATE(db, "buffer cleared"); } } dbuf_clear_data(db); if (multilist_link_active(&db->db_cache_link)) { ASSERT(db->db_caching_status == DB_DBUF_CACHE || db->db_caching_status == DB_DBUF_METADATA_CACHE); multilist_remove(dbuf_caches[db->db_caching_status].cache, db); (void) zfs_refcount_remove_many( &dbuf_caches[db->db_caching_status].size, db->db.db_size, db); if (db->db_caching_status == DB_DBUF_METADATA_CACHE) { DBUF_STAT_BUMPDOWN(metadata_cache_count); } else { DBUF_STAT_BUMPDOWN(cache_levels[db->db_level]); DBUF_STAT_BUMPDOWN(cache_count); DBUF_STAT_DECR(cache_levels_bytes[db->db_level], db->db.db_size); } db->db_caching_status = DB_NO_CACHE; } ASSERT(db->db_state == DB_UNCACHED || db->db_state == DB_NOFILL); ASSERT(db->db_data_pending == NULL); ASSERT(list_is_empty(&db->db_dirty_records)); db->db_state = DB_EVICTING; DTRACE_SET_STATE(db, "buffer eviction started"); db->db_blkptr = NULL; /* * Now that db_state is DB_EVICTING, nobody else can find this via * the hash table. We can now drop db_mtx, which allows us to * acquire the dn_dbufs_mtx. */ mutex_exit(&db->db_mtx); DB_DNODE_ENTER(db); dn = DB_DNODE(db); dndb = dn->dn_dbuf; if (db->db_blkid != DMU_BONUS_BLKID) { boolean_t needlock = !MUTEX_HELD(&dn->dn_dbufs_mtx); if (needlock) mutex_enter_nested(&dn->dn_dbufs_mtx, NESTED_SINGLE); avl_remove(&dn->dn_dbufs, db); membar_producer(); DB_DNODE_EXIT(db); if (needlock) mutex_exit(&dn->dn_dbufs_mtx); /* * Decrementing the dbuf count means that the hold corresponding * to the removed dbuf is no longer discounted in dnode_move(), * so the dnode cannot be moved until after we release the hold. * The membar_producer() ensures visibility of the decremented * value in dnode_move(), since DB_DNODE_EXIT doesn't actually * release any lock. */ mutex_enter(&dn->dn_mtx); dnode_rele_and_unlock(dn, db, B_TRUE); db->db_dnode_handle = NULL; dbuf_hash_remove(db); } else { DB_DNODE_EXIT(db); } ASSERT(zfs_refcount_is_zero(&db->db_holds)); db->db_parent = NULL; ASSERT(db->db_buf == NULL); ASSERT(db->db.db_data == NULL); ASSERT(db->db_hash_next == NULL); ASSERT(db->db_blkptr == NULL); ASSERT(db->db_data_pending == NULL); ASSERT3U(db->db_caching_status, ==, DB_NO_CACHE); ASSERT(!multilist_link_active(&db->db_cache_link)); kmem_cache_free(dbuf_kmem_cache, db); arc_space_return(sizeof (dmu_buf_impl_t), ARC_SPACE_DBUF); /* * If this dbuf is referenced from an indirect dbuf, * decrement the ref count on the indirect dbuf. */ if (parent && parent != dndb) { mutex_enter(&parent->db_mtx); dbuf_rele_and_unlock(parent, db, B_TRUE); } } /* * Note: While bpp will always be updated if the function returns success, * parentp will not be updated if the dnode does not have dn_dbuf filled in; * this happens when the dnode is the meta-dnode, or {user|group|project}used * object. */ __attribute__((always_inline)) static inline int dbuf_findbp(dnode_t *dn, int level, uint64_t blkid, int fail_sparse, dmu_buf_impl_t **parentp, blkptr_t **bpp) { *parentp = NULL; *bpp = NULL; ASSERT(blkid != DMU_BONUS_BLKID); if (blkid == DMU_SPILL_BLKID) { mutex_enter(&dn->dn_mtx); if (dn->dn_have_spill && (dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR)) *bpp = DN_SPILL_BLKPTR(dn->dn_phys); else *bpp = NULL; dbuf_add_ref(dn->dn_dbuf, NULL); *parentp = dn->dn_dbuf; mutex_exit(&dn->dn_mtx); return (0); } int nlevels = (dn->dn_phys->dn_nlevels == 0) ? 1 : dn->dn_phys->dn_nlevels; int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; ASSERT3U(level * epbs, <, 64); ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock)); /* * This assertion shouldn't trip as long as the max indirect block size * is less than 1M. The reason for this is that up to that point, * the number of levels required to address an entire object with blocks * of size SPA_MINBLOCKSIZE satisfies nlevels * epbs + 1 <= 64. In * other words, if N * epbs + 1 > 64, then if (N-1) * epbs + 1 > 55 * (i.e. we can address the entire object), objects will all use at most * N-1 levels and the assertion won't overflow. However, once epbs is * 13, 4 * 13 + 1 = 53, but 5 * 13 + 1 = 66. Then, 4 levels will not be * enough to address an entire object, so objects will have 5 levels, * but then this assertion will overflow. * * All this is to say that if we ever increase DN_MAX_INDBLKSHIFT, we * need to redo this logic to handle overflows. */ ASSERT(level >= nlevels || ((nlevels - level - 1) * epbs) + highbit64(dn->dn_phys->dn_nblkptr) <= 64); if (level >= nlevels || blkid >= ((uint64_t)dn->dn_phys->dn_nblkptr << ((nlevels - level - 1) * epbs)) || (fail_sparse && blkid > (dn->dn_phys->dn_maxblkid >> (level * epbs)))) { /* the buffer has no parent yet */ return (SET_ERROR(ENOENT)); } else if (level < nlevels-1) { /* this block is referenced from an indirect block */ int err; err = dbuf_hold_impl(dn, level + 1, blkid >> epbs, fail_sparse, FALSE, NULL, parentp); if (err) return (err); err = dbuf_read(*parentp, NULL, (DB_RF_HAVESTRUCT | DB_RF_NOPREFETCH | DB_RF_CANFAIL)); if (err) { dbuf_rele(*parentp, NULL); *parentp = NULL; return (err); } rw_enter(&(*parentp)->db_rwlock, RW_READER); *bpp = ((blkptr_t *)(*parentp)->db.db_data) + (blkid & ((1ULL << epbs) - 1)); if (blkid > (dn->dn_phys->dn_maxblkid >> (level * epbs))) ASSERT(BP_IS_HOLE(*bpp)); rw_exit(&(*parentp)->db_rwlock); return (0); } else { /* the block is referenced from the dnode */ ASSERT3U(level, ==, nlevels-1); ASSERT(dn->dn_phys->dn_nblkptr == 0 || blkid < dn->dn_phys->dn_nblkptr); if (dn->dn_dbuf) { dbuf_add_ref(dn->dn_dbuf, NULL); *parentp = dn->dn_dbuf; } *bpp = &dn->dn_phys->dn_blkptr[blkid]; return (0); } } static dmu_buf_impl_t * dbuf_create(dnode_t *dn, uint8_t level, uint64_t blkid, dmu_buf_impl_t *parent, blkptr_t *blkptr) { objset_t *os = dn->dn_objset; dmu_buf_impl_t *db, *odb; ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock)); ASSERT(dn->dn_type != DMU_OT_NONE); db = kmem_cache_alloc(dbuf_kmem_cache, KM_SLEEP); list_create(&db->db_dirty_records, sizeof (dbuf_dirty_record_t), offsetof(dbuf_dirty_record_t, dr_dbuf_node)); db->db_objset = os; db->db.db_object = dn->dn_object; db->db_level = level; db->db_blkid = blkid; db->db_dirtycnt = 0; db->db_dnode_handle = dn->dn_handle; db->db_parent = parent; db->db_blkptr = blkptr; db->db_user = NULL; db->db_user_immediate_evict = FALSE; db->db_freed_in_flight = FALSE; db->db_pending_evict = FALSE; if (blkid == DMU_BONUS_BLKID) { ASSERT3P(parent, ==, dn->dn_dbuf); db->db.db_size = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots) - (dn->dn_nblkptr-1) * sizeof (blkptr_t); ASSERT3U(db->db.db_size, >=, dn->dn_bonuslen); db->db.db_offset = DMU_BONUS_BLKID; db->db_state = DB_UNCACHED; DTRACE_SET_STATE(db, "bonus buffer created"); db->db_caching_status = DB_NO_CACHE; /* the bonus dbuf is not placed in the hash table */ arc_space_consume(sizeof (dmu_buf_impl_t), ARC_SPACE_DBUF); return (db); } else if (blkid == DMU_SPILL_BLKID) { db->db.db_size = (blkptr != NULL) ? BP_GET_LSIZE(blkptr) : SPA_MINBLOCKSIZE; db->db.db_offset = 0; } else { int blocksize = db->db_level ? 1 << dn->dn_indblkshift : dn->dn_datablksz; db->db.db_size = blocksize; db->db.db_offset = db->db_blkid * blocksize; } /* * Hold the dn_dbufs_mtx while we get the new dbuf * in the hash table *and* added to the dbufs list. * This prevents a possible deadlock with someone * trying to look up this dbuf before it's added to the * dn_dbufs list. */ mutex_enter(&dn->dn_dbufs_mtx); db->db_state = DB_EVICTING; /* not worth logging this state change */ if ((odb = dbuf_hash_insert(db)) != NULL) { /* someone else inserted it first */ kmem_cache_free(dbuf_kmem_cache, db); mutex_exit(&dn->dn_dbufs_mtx); DBUF_STAT_BUMP(hash_insert_race); return (odb); } avl_add(&dn->dn_dbufs, db); db->db_state = DB_UNCACHED; DTRACE_SET_STATE(db, "regular buffer created"); db->db_caching_status = DB_NO_CACHE; mutex_exit(&dn->dn_dbufs_mtx); arc_space_consume(sizeof (dmu_buf_impl_t), ARC_SPACE_DBUF); if (parent && parent != dn->dn_dbuf) dbuf_add_ref(parent, db); ASSERT(dn->dn_object == DMU_META_DNODE_OBJECT || zfs_refcount_count(&dn->dn_holds) > 0); (void) zfs_refcount_add(&dn->dn_holds, db); dprintf_dbuf(db, "db=%p\n", db); return (db); } /* * This function returns a block pointer and information about the object, * given a dnode and a block. This is a publicly accessible version of * dbuf_findbp that only returns some information, rather than the * dbuf. Note that the dnode passed in must be held, and the dn_struct_rwlock * should be locked as (at least) a reader. */ int dbuf_dnode_findbp(dnode_t *dn, uint64_t level, uint64_t blkid, blkptr_t *bp, uint16_t *datablkszsec, uint8_t *indblkshift) { dmu_buf_impl_t *dbp = NULL; blkptr_t *bp2; int err = 0; ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock)); err = dbuf_findbp(dn, level, blkid, B_FALSE, &dbp, &bp2); if (err == 0) { *bp = *bp2; if (dbp != NULL) dbuf_rele(dbp, NULL); if (datablkszsec != NULL) *datablkszsec = dn->dn_phys->dn_datablkszsec; if (indblkshift != NULL) *indblkshift = dn->dn_phys->dn_indblkshift; } return (err); } typedef struct dbuf_prefetch_arg { spa_t *dpa_spa; /* The spa to issue the prefetch in. */ zbookmark_phys_t dpa_zb; /* The target block to prefetch. */ int dpa_epbs; /* Entries (blkptr_t's) Per Block Shift. */ int dpa_curlevel; /* The current level that we're reading */ dnode_t *dpa_dnode; /* The dnode associated with the prefetch */ zio_priority_t dpa_prio; /* The priority I/Os should be issued at. */ zio_t *dpa_zio; /* The parent zio_t for all prefetches. */ arc_flags_t dpa_aflags; /* Flags to pass to the final prefetch. */ dbuf_prefetch_fn dpa_cb; /* prefetch completion callback */ void *dpa_arg; /* prefetch completion arg */ } dbuf_prefetch_arg_t; static void dbuf_prefetch_fini(dbuf_prefetch_arg_t *dpa, boolean_t io_done) { if (dpa->dpa_cb != NULL) dpa->dpa_cb(dpa->dpa_arg, io_done); kmem_free(dpa, sizeof (*dpa)); } static void dbuf_issue_final_prefetch_done(zio_t *zio, const zbookmark_phys_t *zb, const blkptr_t *iobp, arc_buf_t *abuf, void *private) { dbuf_prefetch_arg_t *dpa = private; dbuf_prefetch_fini(dpa, B_TRUE); if (abuf != NULL) arc_buf_destroy(abuf, private); } /* * Actually issue the prefetch read for the block given. */ static void dbuf_issue_final_prefetch(dbuf_prefetch_arg_t *dpa, blkptr_t *bp) { ASSERT(!BP_IS_REDACTED(bp) || dsl_dataset_feature_is_active( dpa->dpa_dnode->dn_objset->os_dsl_dataset, SPA_FEATURE_REDACTED_DATASETS)); if (BP_IS_HOLE(bp) || BP_IS_EMBEDDED(bp) || BP_IS_REDACTED(bp)) return (dbuf_prefetch_fini(dpa, B_FALSE)); int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE; arc_flags_t aflags = dpa->dpa_aflags | ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH | ARC_FLAG_NO_BUF; /* dnodes are always read as raw and then converted later */ if (BP_GET_TYPE(bp) == DMU_OT_DNODE && BP_IS_PROTECTED(bp) && dpa->dpa_curlevel == 0) zio_flags |= ZIO_FLAG_RAW; ASSERT3U(dpa->dpa_curlevel, ==, BP_GET_LEVEL(bp)); ASSERT3U(dpa->dpa_curlevel, ==, dpa->dpa_zb.zb_level); ASSERT(dpa->dpa_zio != NULL); (void) arc_read(dpa->dpa_zio, dpa->dpa_spa, bp, dbuf_issue_final_prefetch_done, dpa, dpa->dpa_prio, zio_flags, &aflags, &dpa->dpa_zb); } /* * Called when an indirect block above our prefetch target is read in. This * will either read in the next indirect block down the tree or issue the actual * prefetch if the next block down is our target. */ static void dbuf_prefetch_indirect_done(zio_t *zio, const zbookmark_phys_t *zb, const blkptr_t *iobp, arc_buf_t *abuf, void *private) { dbuf_prefetch_arg_t *dpa = private; ASSERT3S(dpa->dpa_zb.zb_level, <, dpa->dpa_curlevel); ASSERT3S(dpa->dpa_curlevel, >, 0); if (abuf == NULL) { ASSERT(zio == NULL || zio->io_error != 0); return (dbuf_prefetch_fini(dpa, B_TRUE)); } ASSERT(zio == NULL || zio->io_error == 0); /* * The dpa_dnode is only valid if we are called with a NULL * zio. This indicates that the arc_read() returned without * first calling zio_read() to issue a physical read. Once * a physical read is made the dpa_dnode must be invalidated * as the locks guarding it may have been dropped. If the * dpa_dnode is still valid, then we want to add it to the dbuf * cache. To do so, we must hold the dbuf associated with the block * we just prefetched, read its contents so that we associate it * with an arc_buf_t, and then release it. */ if (zio != NULL) { ASSERT3S(BP_GET_LEVEL(zio->io_bp), ==, dpa->dpa_curlevel); if (zio->io_flags & ZIO_FLAG_RAW_COMPRESS) { ASSERT3U(BP_GET_PSIZE(zio->io_bp), ==, zio->io_size); } else { ASSERT3U(BP_GET_LSIZE(zio->io_bp), ==, zio->io_size); } ASSERT3P(zio->io_spa, ==, dpa->dpa_spa); dpa->dpa_dnode = NULL; } else if (dpa->dpa_dnode != NULL) { uint64_t curblkid = dpa->dpa_zb.zb_blkid >> (dpa->dpa_epbs * (dpa->dpa_curlevel - dpa->dpa_zb.zb_level)); dmu_buf_impl_t *db = dbuf_hold_level(dpa->dpa_dnode, dpa->dpa_curlevel, curblkid, FTAG); if (db == NULL) { arc_buf_destroy(abuf, private); return (dbuf_prefetch_fini(dpa, B_TRUE)); } (void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH | DB_RF_HAVESTRUCT); dbuf_rele(db, FTAG); } dpa->dpa_curlevel--; uint64_t nextblkid = dpa->dpa_zb.zb_blkid >> (dpa->dpa_epbs * (dpa->dpa_curlevel - dpa->dpa_zb.zb_level)); blkptr_t *bp = ((blkptr_t *)abuf->b_data) + P2PHASE(nextblkid, 1ULL << dpa->dpa_epbs); ASSERT(!BP_IS_REDACTED(bp) || dsl_dataset_feature_is_active( dpa->dpa_dnode->dn_objset->os_dsl_dataset, SPA_FEATURE_REDACTED_DATASETS)); if (BP_IS_HOLE(bp) || BP_IS_REDACTED(bp)) { dbuf_prefetch_fini(dpa, B_TRUE); } else if (dpa->dpa_curlevel == dpa->dpa_zb.zb_level) { ASSERT3U(nextblkid, ==, dpa->dpa_zb.zb_blkid); dbuf_issue_final_prefetch(dpa, bp); } else { arc_flags_t iter_aflags = ARC_FLAG_NOWAIT; zbookmark_phys_t zb; /* flag if L2ARC eligible, l2arc_noprefetch then decides */ if (dpa->dpa_aflags & ARC_FLAG_L2CACHE) iter_aflags |= ARC_FLAG_L2CACHE; ASSERT3U(dpa->dpa_curlevel, ==, BP_GET_LEVEL(bp)); SET_BOOKMARK(&zb, dpa->dpa_zb.zb_objset, dpa->dpa_zb.zb_object, dpa->dpa_curlevel, nextblkid); (void) arc_read(dpa->dpa_zio, dpa->dpa_spa, bp, dbuf_prefetch_indirect_done, dpa, dpa->dpa_prio, ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, &iter_aflags, &zb); } arc_buf_destroy(abuf, private); } /* * Issue prefetch reads for the given block on the given level. If the indirect * blocks above that block are not in memory, we will read them in * asynchronously. As a result, this call never blocks waiting for a read to * complete. Note that the prefetch might fail if the dataset is encrypted and * the encryption key is unmapped before the IO completes. */ int dbuf_prefetch_impl(dnode_t *dn, int64_t level, uint64_t blkid, zio_priority_t prio, arc_flags_t aflags, dbuf_prefetch_fn cb, void *arg) { blkptr_t bp; int epbs, nlevels, curlevel; uint64_t curblkid; ASSERT(blkid != DMU_BONUS_BLKID); ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock)); if (blkid > dn->dn_maxblkid) goto no_issue; if (level == 0 && dnode_block_freed(dn, blkid)) goto no_issue; /* * This dnode hasn't been written to disk yet, so there's nothing to * prefetch. */ nlevels = dn->dn_phys->dn_nlevels; if (level >= nlevels || dn->dn_phys->dn_nblkptr == 0) goto no_issue; epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; if (dn->dn_phys->dn_maxblkid < blkid << (epbs * level)) goto no_issue; dmu_buf_impl_t *db = dbuf_find(dn->dn_objset, dn->dn_object, level, blkid); if (db != NULL) { mutex_exit(&db->db_mtx); /* * This dbuf already exists. It is either CACHED, or * (we assume) about to be read or filled. */ goto no_issue; } /* * Find the closest ancestor (indirect block) of the target block * that is present in the cache. In this indirect block, we will * find the bp that is at curlevel, curblkid. */ curlevel = level; curblkid = blkid; while (curlevel < nlevels - 1) { int parent_level = curlevel + 1; uint64_t parent_blkid = curblkid >> epbs; dmu_buf_impl_t *db; if (dbuf_hold_impl(dn, parent_level, parent_blkid, FALSE, TRUE, FTAG, &db) == 0) { blkptr_t *bpp = db->db_buf->b_data; bp = bpp[P2PHASE(curblkid, 1 << epbs)]; dbuf_rele(db, FTAG); break; } curlevel = parent_level; curblkid = parent_blkid; } if (curlevel == nlevels - 1) { /* No cached indirect blocks found. */ ASSERT3U(curblkid, <, dn->dn_phys->dn_nblkptr); bp = dn->dn_phys->dn_blkptr[curblkid]; } ASSERT(!BP_IS_REDACTED(&bp) || dsl_dataset_feature_is_active(dn->dn_objset->os_dsl_dataset, SPA_FEATURE_REDACTED_DATASETS)); if (BP_IS_HOLE(&bp) || BP_IS_REDACTED(&bp)) goto no_issue; ASSERT3U(curlevel, ==, BP_GET_LEVEL(&bp)); zio_t *pio = zio_root(dmu_objset_spa(dn->dn_objset), NULL, NULL, ZIO_FLAG_CANFAIL); dbuf_prefetch_arg_t *dpa = kmem_zalloc(sizeof (*dpa), KM_SLEEP); dsl_dataset_t *ds = dn->dn_objset->os_dsl_dataset; SET_BOOKMARK(&dpa->dpa_zb, ds != NULL ? ds->ds_object : DMU_META_OBJSET, dn->dn_object, level, blkid); dpa->dpa_curlevel = curlevel; dpa->dpa_prio = prio; dpa->dpa_aflags = aflags; dpa->dpa_spa = dn->dn_objset->os_spa; dpa->dpa_dnode = dn; dpa->dpa_epbs = epbs; dpa->dpa_zio = pio; dpa->dpa_cb = cb; dpa->dpa_arg = arg; /* flag if L2ARC eligible, l2arc_noprefetch then decides */ if (DNODE_LEVEL_IS_L2CACHEABLE(dn, level)) dpa->dpa_aflags |= ARC_FLAG_L2CACHE; /* * If we have the indirect just above us, no need to do the asynchronous * prefetch chain; we'll just run the last step ourselves. If we're at * a higher level, though, we want to issue the prefetches for all the * indirect blocks asynchronously, so we can go on with whatever we were * doing. */ if (curlevel == level) { ASSERT3U(curblkid, ==, blkid); dbuf_issue_final_prefetch(dpa, &bp); } else { arc_flags_t iter_aflags = ARC_FLAG_NOWAIT; zbookmark_phys_t zb; /* flag if L2ARC eligible, l2arc_noprefetch then decides */ if (DNODE_LEVEL_IS_L2CACHEABLE(dn, level)) iter_aflags |= ARC_FLAG_L2CACHE; SET_BOOKMARK(&zb, ds != NULL ? ds->ds_object : DMU_META_OBJSET, dn->dn_object, curlevel, curblkid); (void) arc_read(dpa->dpa_zio, dpa->dpa_spa, &bp, dbuf_prefetch_indirect_done, dpa, prio, ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, &iter_aflags, &zb); } /* * We use pio here instead of dpa_zio since it's possible that * dpa may have already been freed. */ zio_nowait(pio); return (1); no_issue: if (cb != NULL) cb(arg, B_FALSE); return (0); } int dbuf_prefetch(dnode_t *dn, int64_t level, uint64_t blkid, zio_priority_t prio, arc_flags_t aflags) { return (dbuf_prefetch_impl(dn, level, blkid, prio, aflags, NULL, NULL)); } /* * Helper function for dbuf_hold_impl() to copy a buffer. Handles * the case of encrypted, compressed and uncompressed buffers by * allocating the new buffer, respectively, with arc_alloc_raw_buf(), * arc_alloc_compressed_buf() or arc_alloc_buf().* * * NOTE: Declared noinline to avoid stack bloat in dbuf_hold_impl(). */ noinline static void dbuf_hold_copy(dnode_t *dn, dmu_buf_impl_t *db) { dbuf_dirty_record_t *dr = db->db_data_pending; arc_buf_t *newdata, *data = dr->dt.dl.dr_data; newdata = dbuf_alloc_arcbuf_from_arcbuf(db, data); dbuf_set_data(db, newdata); rw_enter(&db->db_rwlock, RW_WRITER); bcopy(data->b_data, db->db.db_data, arc_buf_size(data)); rw_exit(&db->db_rwlock); } /* * Returns with db_holds incremented, and db_mtx not held. * Note: dn_struct_rwlock must be held. */ int dbuf_hold_impl(dnode_t *dn, uint8_t level, uint64_t blkid, boolean_t fail_sparse, boolean_t fail_uncached, void *tag, dmu_buf_impl_t **dbp) { dmu_buf_impl_t *db, *parent = NULL; /* If the pool has been created, verify the tx_sync_lock is not held */ spa_t *spa = dn->dn_objset->os_spa; dsl_pool_t *dp = spa->spa_dsl_pool; if (dp != NULL) { ASSERT(!MUTEX_HELD(&dp->dp_tx.tx_sync_lock)); } ASSERT(blkid != DMU_BONUS_BLKID); ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock)); ASSERT3U(dn->dn_nlevels, >, level); *dbp = NULL; /* dbuf_find() returns with db_mtx held */ db = dbuf_find(dn->dn_objset, dn->dn_object, level, blkid); if (db == NULL) { blkptr_t *bp = NULL; int err; if (fail_uncached) return (SET_ERROR(ENOENT)); ASSERT3P(parent, ==, NULL); err = dbuf_findbp(dn, level, blkid, fail_sparse, &parent, &bp); if (fail_sparse) { if (err == 0 && bp && BP_IS_HOLE(bp)) err = SET_ERROR(ENOENT); if (err) { if (parent) dbuf_rele(parent, NULL); return (err); } } if (err && err != ENOENT) return (err); db = dbuf_create(dn, level, blkid, parent, bp); } if (fail_uncached && db->db_state != DB_CACHED) { mutex_exit(&db->db_mtx); return (SET_ERROR(ENOENT)); } if (db->db_buf != NULL) { arc_buf_access(db->db_buf); ASSERT3P(db->db.db_data, ==, db->db_buf->b_data); } ASSERT(db->db_buf == NULL || arc_referenced(db->db_buf)); /* * If this buffer is currently syncing out, and we are * still referencing it from db_data, we need to make a copy * of it in case we decide we want to dirty it again in this txg. */ if (db->db_level == 0 && db->db_blkid != DMU_BONUS_BLKID && dn->dn_object != DMU_META_DNODE_OBJECT && db->db_state == DB_CACHED && db->db_data_pending) { dbuf_dirty_record_t *dr = db->db_data_pending; if (dr->dt.dl.dr_data == db->db_buf) dbuf_hold_copy(dn, db); } if (multilist_link_active(&db->db_cache_link)) { ASSERT(zfs_refcount_is_zero(&db->db_holds)); ASSERT(db->db_caching_status == DB_DBUF_CACHE || db->db_caching_status == DB_DBUF_METADATA_CACHE); multilist_remove(dbuf_caches[db->db_caching_status].cache, db); (void) zfs_refcount_remove_many( &dbuf_caches[db->db_caching_status].size, db->db.db_size, db); if (db->db_caching_status == DB_DBUF_METADATA_CACHE) { DBUF_STAT_BUMPDOWN(metadata_cache_count); } else { DBUF_STAT_BUMPDOWN(cache_levels[db->db_level]); DBUF_STAT_BUMPDOWN(cache_count); DBUF_STAT_DECR(cache_levels_bytes[db->db_level], db->db.db_size); } db->db_caching_status = DB_NO_CACHE; } (void) zfs_refcount_add(&db->db_holds, tag); DBUF_VERIFY(db); mutex_exit(&db->db_mtx); /* NOTE: we can't rele the parent until after we drop the db_mtx */ if (parent) dbuf_rele(parent, NULL); ASSERT3P(DB_DNODE(db), ==, dn); ASSERT3U(db->db_blkid, ==, blkid); ASSERT3U(db->db_level, ==, level); *dbp = db; return (0); } dmu_buf_impl_t * dbuf_hold(dnode_t *dn, uint64_t blkid, void *tag) { return (dbuf_hold_level(dn, 0, blkid, tag)); } dmu_buf_impl_t * dbuf_hold_level(dnode_t *dn, int level, uint64_t blkid, void *tag) { dmu_buf_impl_t *db; int err = dbuf_hold_impl(dn, level, blkid, FALSE, FALSE, tag, &db); return (err ? NULL : db); } void dbuf_create_bonus(dnode_t *dn) { ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock)); ASSERT(dn->dn_bonus == NULL); dn->dn_bonus = dbuf_create(dn, 0, DMU_BONUS_BLKID, dn->dn_dbuf, NULL); } int dbuf_spill_set_blksz(dmu_buf_t *db_fake, uint64_t blksz, dmu_tx_t *tx) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; if (db->db_blkid != DMU_SPILL_BLKID) return (SET_ERROR(ENOTSUP)); if (blksz == 0) blksz = SPA_MINBLOCKSIZE; ASSERT3U(blksz, <=, spa_maxblocksize(dmu_objset_spa(db->db_objset))); blksz = P2ROUNDUP(blksz, SPA_MINBLOCKSIZE); dbuf_new_size(db, blksz, tx); return (0); } void dbuf_rm_spill(dnode_t *dn, dmu_tx_t *tx) { dbuf_free_range(dn, DMU_SPILL_BLKID, DMU_SPILL_BLKID, tx); } #pragma weak dmu_buf_add_ref = dbuf_add_ref void dbuf_add_ref(dmu_buf_impl_t *db, void *tag) { int64_t holds = zfs_refcount_add(&db->db_holds, tag); VERIFY3S(holds, >, 1); } #pragma weak dmu_buf_try_add_ref = dbuf_try_add_ref boolean_t dbuf_try_add_ref(dmu_buf_t *db_fake, objset_t *os, uint64_t obj, uint64_t blkid, void *tag) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; dmu_buf_impl_t *found_db; boolean_t result = B_FALSE; if (blkid == DMU_BONUS_BLKID) found_db = dbuf_find_bonus(os, obj); else found_db = dbuf_find(os, obj, 0, blkid); if (found_db != NULL) { if (db == found_db && dbuf_refcount(db) > db->db_dirtycnt) { (void) zfs_refcount_add(&db->db_holds, tag); result = B_TRUE; } mutex_exit(&found_db->db_mtx); } return (result); } /* * If you call dbuf_rele() you had better not be referencing the dnode handle * unless you have some other direct or indirect hold on the dnode. (An indirect * hold is a hold on one of the dnode's dbufs, including the bonus buffer.) * Without that, the dbuf_rele() could lead to a dnode_rele() followed by the * dnode's parent dbuf evicting its dnode handles. */ void dbuf_rele(dmu_buf_impl_t *db, void *tag) { mutex_enter(&db->db_mtx); dbuf_rele_and_unlock(db, tag, B_FALSE); } void dmu_buf_rele(dmu_buf_t *db, void *tag) { dbuf_rele((dmu_buf_impl_t *)db, tag); } /* * dbuf_rele() for an already-locked dbuf. This is necessary to allow * db_dirtycnt and db_holds to be updated atomically. The 'evicting' * argument should be set if we are already in the dbuf-evicting code * path, in which case we don't want to recursively evict. This allows us to * avoid deeply nested stacks that would have a call flow similar to this: * * dbuf_rele()-->dbuf_rele_and_unlock()-->dbuf_evict_notify() * ^ | * | | * +-----dbuf_destroy()<--dbuf_evict_one()<--------+ * */ void dbuf_rele_and_unlock(dmu_buf_impl_t *db, void *tag, boolean_t evicting) { int64_t holds; uint64_t size; ASSERT(MUTEX_HELD(&db->db_mtx)); DBUF_VERIFY(db); /* * Remove the reference to the dbuf before removing its hold on the * dnode so we can guarantee in dnode_move() that a referenced bonus * buffer has a corresponding dnode hold. */ holds = zfs_refcount_remove(&db->db_holds, tag); ASSERT(holds >= 0); /* * We can't freeze indirects if there is a possibility that they * may be modified in the current syncing context. */ if (db->db_buf != NULL && holds == (db->db_level == 0 ? db->db_dirtycnt : 0)) { arc_buf_freeze(db->db_buf); } if (holds == db->db_dirtycnt && db->db_level == 0 && db->db_user_immediate_evict) dbuf_evict_user(db); if (holds == 0) { if (db->db_blkid == DMU_BONUS_BLKID) { dnode_t *dn; boolean_t evict_dbuf = db->db_pending_evict; /* * If the dnode moves here, we cannot cross this * barrier until the move completes. */ DB_DNODE_ENTER(db); dn = DB_DNODE(db); atomic_dec_32(&dn->dn_dbufs_count); /* * Decrementing the dbuf count means that the bonus * buffer's dnode hold is no longer discounted in * dnode_move(). The dnode cannot move until after * the dnode_rele() below. */ DB_DNODE_EXIT(db); /* * Do not reference db after its lock is dropped. * Another thread may evict it. */ mutex_exit(&db->db_mtx); if (evict_dbuf) dnode_evict_bonus(dn); dnode_rele(dn, db); } else if (db->db_buf == NULL) { /* * This is a special case: we never associated this * dbuf with any data allocated from the ARC. */ ASSERT(db->db_state == DB_UNCACHED || db->db_state == DB_NOFILL); dbuf_destroy(db); } else if (arc_released(db->db_buf)) { /* * This dbuf has anonymous data associated with it. */ dbuf_destroy(db); } else { boolean_t do_arc_evict = B_FALSE; blkptr_t bp; spa_t *spa = dmu_objset_spa(db->db_objset); if (!DBUF_IS_CACHEABLE(db) && db->db_blkptr != NULL && !BP_IS_HOLE(db->db_blkptr) && !BP_IS_EMBEDDED(db->db_blkptr)) { do_arc_evict = B_TRUE; bp = *db->db_blkptr; } if (!DBUF_IS_CACHEABLE(db) || db->db_pending_evict) { dbuf_destroy(db); } else if (!multilist_link_active(&db->db_cache_link)) { ASSERT3U(db->db_caching_status, ==, DB_NO_CACHE); dbuf_cached_state_t dcs = dbuf_include_in_metadata_cache(db) ? DB_DBUF_METADATA_CACHE : DB_DBUF_CACHE; db->db_caching_status = dcs; multilist_insert(dbuf_caches[dcs].cache, db); size = zfs_refcount_add_many( &dbuf_caches[dcs].size, db->db.db_size, db); if (dcs == DB_DBUF_METADATA_CACHE) { DBUF_STAT_BUMP(metadata_cache_count); DBUF_STAT_MAX( metadata_cache_size_bytes_max, size); } else { DBUF_STAT_BUMP( cache_levels[db->db_level]); DBUF_STAT_BUMP(cache_count); DBUF_STAT_INCR( cache_levels_bytes[db->db_level], db->db.db_size); DBUF_STAT_MAX(cache_size_bytes_max, size); } mutex_exit(&db->db_mtx); if (dcs == DB_DBUF_CACHE && !evicting) dbuf_evict_notify(size); } if (do_arc_evict) arc_freed(spa, &bp); } } else { mutex_exit(&db->db_mtx); } } #pragma weak dmu_buf_refcount = dbuf_refcount uint64_t dbuf_refcount(dmu_buf_impl_t *db) { return (zfs_refcount_count(&db->db_holds)); } uint64_t dmu_buf_user_refcount(dmu_buf_t *db_fake) { uint64_t holds; dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; mutex_enter(&db->db_mtx); ASSERT3U(zfs_refcount_count(&db->db_holds), >=, db->db_dirtycnt); holds = zfs_refcount_count(&db->db_holds) - db->db_dirtycnt; mutex_exit(&db->db_mtx); return (holds); } void * dmu_buf_replace_user(dmu_buf_t *db_fake, dmu_buf_user_t *old_user, dmu_buf_user_t *new_user) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; mutex_enter(&db->db_mtx); dbuf_verify_user(db, DBVU_NOT_EVICTING); if (db->db_user == old_user) db->db_user = new_user; else old_user = db->db_user; dbuf_verify_user(db, DBVU_NOT_EVICTING); mutex_exit(&db->db_mtx); return (old_user); } void * dmu_buf_set_user(dmu_buf_t *db_fake, dmu_buf_user_t *user) { return (dmu_buf_replace_user(db_fake, NULL, user)); } void * dmu_buf_set_user_ie(dmu_buf_t *db_fake, dmu_buf_user_t *user) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; db->db_user_immediate_evict = TRUE; return (dmu_buf_set_user(db_fake, user)); } void * dmu_buf_remove_user(dmu_buf_t *db_fake, dmu_buf_user_t *user) { return (dmu_buf_replace_user(db_fake, user, NULL)); } void * dmu_buf_get_user(dmu_buf_t *db_fake) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; dbuf_verify_user(db, DBVU_NOT_EVICTING); return (db->db_user); } void dmu_buf_user_evict_wait() { taskq_wait(dbu_evict_taskq); } blkptr_t * dmu_buf_get_blkptr(dmu_buf_t *db) { dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db; return (dbi->db_blkptr); } objset_t * dmu_buf_get_objset(dmu_buf_t *db) { dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db; return (dbi->db_objset); } dnode_t * dmu_buf_dnode_enter(dmu_buf_t *db) { dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db; DB_DNODE_ENTER(dbi); return (DB_DNODE(dbi)); } void dmu_buf_dnode_exit(dmu_buf_t *db) { dmu_buf_impl_t *dbi = (dmu_buf_impl_t *)db; DB_DNODE_EXIT(dbi); } static void dbuf_check_blkptr(dnode_t *dn, dmu_buf_impl_t *db) { /* ASSERT(dmu_tx_is_syncing(tx) */ ASSERT(MUTEX_HELD(&db->db_mtx)); if (db->db_blkptr != NULL) return; if (db->db_blkid == DMU_SPILL_BLKID) { db->db_blkptr = DN_SPILL_BLKPTR(dn->dn_phys); BP_ZERO(db->db_blkptr); return; } if (db->db_level == dn->dn_phys->dn_nlevels-1) { /* * This buffer was allocated at a time when there was * no available blkptrs from the dnode, or it was * inappropriate to hook it in (i.e., nlevels mismatch). */ ASSERT(db->db_blkid < dn->dn_phys->dn_nblkptr); ASSERT(db->db_parent == NULL); db->db_parent = dn->dn_dbuf; db->db_blkptr = &dn->dn_phys->dn_blkptr[db->db_blkid]; DBUF_VERIFY(db); } else { dmu_buf_impl_t *parent = db->db_parent; int epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; ASSERT(dn->dn_phys->dn_nlevels > 1); if (parent == NULL) { mutex_exit(&db->db_mtx); rw_enter(&dn->dn_struct_rwlock, RW_READER); parent = dbuf_hold_level(dn, db->db_level + 1, db->db_blkid >> epbs, db); rw_exit(&dn->dn_struct_rwlock); mutex_enter(&db->db_mtx); db->db_parent = parent; } db->db_blkptr = (blkptr_t *)parent->db.db_data + (db->db_blkid & ((1ULL << epbs) - 1)); DBUF_VERIFY(db); } } static void dbuf_sync_bonus(dbuf_dirty_record_t *dr, dmu_tx_t *tx) { dmu_buf_impl_t *db = dr->dr_dbuf; void *data = dr->dt.dl.dr_data; ASSERT0(db->db_level); ASSERT(MUTEX_HELD(&db->db_mtx)); ASSERT(db->db_blkid == DMU_BONUS_BLKID); ASSERT(data != NULL); dnode_t *dn = dr->dr_dnode; ASSERT3U(DN_MAX_BONUS_LEN(dn->dn_phys), <=, DN_SLOTS_TO_BONUSLEN(dn->dn_phys->dn_extra_slots + 1)); bcopy(data, DN_BONUS(dn->dn_phys), DN_MAX_BONUS_LEN(dn->dn_phys)); dbuf_sync_leaf_verify_bonus_dnode(dr); dbuf_undirty_bonus(dr); dbuf_rele_and_unlock(db, (void *)(uintptr_t)tx->tx_txg, B_FALSE); } /* * When syncing out a blocks of dnodes, adjust the block to deal with * encryption. Normally, we make sure the block is decrypted before writing * it. If we have crypt params, then we are writing a raw (encrypted) block, * from a raw receive. In this case, set the ARC buf's crypt params so * that the BP will be filled with the correct byteorder, salt, iv, and mac. */ static void dbuf_prepare_encrypted_dnode_leaf(dbuf_dirty_record_t *dr) { int err; dmu_buf_impl_t *db = dr->dr_dbuf; ASSERT(MUTEX_HELD(&db->db_mtx)); ASSERT3U(db->db.db_object, ==, DMU_META_DNODE_OBJECT); ASSERT3U(db->db_level, ==, 0); if (!db->db_objset->os_raw_receive && arc_is_encrypted(db->db_buf)) { zbookmark_phys_t zb; /* * Unfortunately, there is currently no mechanism for * syncing context to handle decryption errors. An error * here is only possible if an attacker maliciously * changed a dnode block and updated the associated * checksums going up the block tree. */ SET_BOOKMARK(&zb, dmu_objset_id(db->db_objset), db->db.db_object, db->db_level, db->db_blkid); err = arc_untransform(db->db_buf, db->db_objset->os_spa, &zb, B_TRUE); if (err) panic("Invalid dnode block MAC"); } else if (dr->dt.dl.dr_has_raw_params) { (void) arc_release(dr->dt.dl.dr_data, db); arc_convert_to_raw(dr->dt.dl.dr_data, dmu_objset_id(db->db_objset), dr->dt.dl.dr_byteorder, DMU_OT_DNODE, dr->dt.dl.dr_salt, dr->dt.dl.dr_iv, dr->dt.dl.dr_mac); } } /* * dbuf_sync_indirect() is called recursively from dbuf_sync_list() so it * is critical the we not allow the compiler to inline this function in to * dbuf_sync_list() thereby drastically bloating the stack usage. */ noinline static void dbuf_sync_indirect(dbuf_dirty_record_t *dr, dmu_tx_t *tx) { dmu_buf_impl_t *db = dr->dr_dbuf; dnode_t *dn = dr->dr_dnode; ASSERT(dmu_tx_is_syncing(tx)); dprintf_dbuf_bp(db, db->db_blkptr, "blkptr=%p", db->db_blkptr); mutex_enter(&db->db_mtx); ASSERT(db->db_level > 0); DBUF_VERIFY(db); /* Read the block if it hasn't been read yet. */ if (db->db_buf == NULL) { mutex_exit(&db->db_mtx); (void) dbuf_read(db, NULL, DB_RF_MUST_SUCCEED); mutex_enter(&db->db_mtx); } ASSERT3U(db->db_state, ==, DB_CACHED); ASSERT(db->db_buf != NULL); /* Indirect block size must match what the dnode thinks it is. */ ASSERT3U(db->db.db_size, ==, 1<dn_phys->dn_indblkshift); dbuf_check_blkptr(dn, db); /* Provide the pending dirty record to child dbufs */ db->db_data_pending = dr; mutex_exit(&db->db_mtx); dbuf_write(dr, db->db_buf, tx); zio_t *zio = dr->dr_zio; mutex_enter(&dr->dt.di.dr_mtx); dbuf_sync_list(&dr->dt.di.dr_children, db->db_level - 1, tx); ASSERT(list_head(&dr->dt.di.dr_children) == NULL); mutex_exit(&dr->dt.di.dr_mtx); zio_nowait(zio); } /* * Verify that the size of the data in our bonus buffer does not exceed * its recorded size. * * The purpose of this verification is to catch any cases in development * where the size of a phys structure (i.e space_map_phys_t) grows and, * due to incorrect feature management, older pools expect to read more * data even though they didn't actually write it to begin with. * * For a example, this would catch an error in the feature logic where we * open an older pool and we expect to write the space map histogram of * a space map with size SPACE_MAP_SIZE_V0. */ static void dbuf_sync_leaf_verify_bonus_dnode(dbuf_dirty_record_t *dr) { #ifdef ZFS_DEBUG dnode_t *dn = dr->dr_dnode; /* * Encrypted bonus buffers can have data past their bonuslen. * Skip the verification of these blocks. */ if (DMU_OT_IS_ENCRYPTED(dn->dn_bonustype)) return; uint16_t bonuslen = dn->dn_phys->dn_bonuslen; uint16_t maxbonuslen = DN_SLOTS_TO_BONUSLEN(dn->dn_num_slots); ASSERT3U(bonuslen, <=, maxbonuslen); arc_buf_t *datap = dr->dt.dl.dr_data; char *datap_end = ((char *)datap) + bonuslen; char *datap_max = ((char *)datap) + maxbonuslen; /* ensure that everything is zero after our data */ for (; datap_end < datap_max; datap_end++) ASSERT(*datap_end == 0); #endif } static blkptr_t * dbuf_lightweight_bp(dbuf_dirty_record_t *dr) { /* This must be a lightweight dirty record. */ ASSERT3P(dr->dr_dbuf, ==, NULL); dnode_t *dn = dr->dr_dnode; if (dn->dn_phys->dn_nlevels == 1) { VERIFY3U(dr->dt.dll.dr_blkid, <, dn->dn_phys->dn_nblkptr); return (&dn->dn_phys->dn_blkptr[dr->dt.dll.dr_blkid]); } else { dmu_buf_impl_t *parent_db = dr->dr_parent->dr_dbuf; int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; VERIFY3U(parent_db->db_level, ==, 1); VERIFY3P(parent_db->db_dnode_handle->dnh_dnode, ==, dn); VERIFY3U(dr->dt.dll.dr_blkid >> epbs, ==, parent_db->db_blkid); blkptr_t *bp = parent_db->db.db_data; return (&bp[dr->dt.dll.dr_blkid & ((1 << epbs) - 1)]); } } static void dbuf_lightweight_ready(zio_t *zio) { dbuf_dirty_record_t *dr = zio->io_private; blkptr_t *bp = zio->io_bp; if (zio->io_error != 0) return; dnode_t *dn = dr->dr_dnode; blkptr_t *bp_orig = dbuf_lightweight_bp(dr); spa_t *spa = dmu_objset_spa(dn->dn_objset); int64_t delta = bp_get_dsize_sync(spa, bp) - bp_get_dsize_sync(spa, bp_orig); dnode_diduse_space(dn, delta); uint64_t blkid = dr->dt.dll.dr_blkid; mutex_enter(&dn->dn_mtx); if (blkid > dn->dn_phys->dn_maxblkid) { ASSERT0(dn->dn_objset->os_raw_receive); dn->dn_phys->dn_maxblkid = blkid; } mutex_exit(&dn->dn_mtx); if (!BP_IS_EMBEDDED(bp)) { uint64_t fill = BP_IS_HOLE(bp) ? 0 : 1; BP_SET_FILL(bp, fill); } dmu_buf_impl_t *parent_db; EQUIV(dr->dr_parent == NULL, dn->dn_phys->dn_nlevels == 1); if (dr->dr_parent == NULL) { parent_db = dn->dn_dbuf; } else { parent_db = dr->dr_parent->dr_dbuf; } rw_enter(&parent_db->db_rwlock, RW_WRITER); *bp_orig = *bp; rw_exit(&parent_db->db_rwlock); } static void dbuf_lightweight_physdone(zio_t *zio) { dbuf_dirty_record_t *dr = zio->io_private; dsl_pool_t *dp = spa_get_dsl(zio->io_spa); ASSERT3U(dr->dr_txg, ==, zio->io_txg); /* * The callback will be called io_phys_children times. Retire one * portion of our dirty space each time we are called. Any rounding * error will be cleaned up by dbuf_lightweight_done(). */ int delta = dr->dr_accounted / zio->io_phys_children; dsl_pool_undirty_space(dp, delta, zio->io_txg); } static void dbuf_lightweight_done(zio_t *zio) { dbuf_dirty_record_t *dr = zio->io_private; VERIFY0(zio->io_error); objset_t *os = dr->dr_dnode->dn_objset; dmu_tx_t *tx = os->os_synctx; if (zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE)) { ASSERT(BP_EQUAL(zio->io_bp, &zio->io_bp_orig)); } else { dsl_dataset_t *ds = os->os_dsl_dataset; (void) dsl_dataset_block_kill(ds, &zio->io_bp_orig, tx, B_TRUE); dsl_dataset_block_born(ds, zio->io_bp, tx); } /* * See comment in dbuf_write_done(). */ if (zio->io_phys_children == 0) { dsl_pool_undirty_space(dmu_objset_pool(os), dr->dr_accounted, zio->io_txg); } else { dsl_pool_undirty_space(dmu_objset_pool(os), dr->dr_accounted % zio->io_phys_children, zio->io_txg); } abd_free(dr->dt.dll.dr_abd); kmem_free(dr, sizeof (*dr)); } noinline static void dbuf_sync_lightweight(dbuf_dirty_record_t *dr, dmu_tx_t *tx) { dnode_t *dn = dr->dr_dnode; zio_t *pio; if (dn->dn_phys->dn_nlevels == 1) { pio = dn->dn_zio; } else { pio = dr->dr_parent->dr_zio; } zbookmark_phys_t zb = { .zb_objset = dmu_objset_id(dn->dn_objset), .zb_object = dn->dn_object, .zb_level = 0, .zb_blkid = dr->dt.dll.dr_blkid, }; /* * See comment in dbuf_write(). This is so that zio->io_bp_orig * will have the old BP in dbuf_lightweight_done(). */ dr->dr_bp_copy = *dbuf_lightweight_bp(dr); dr->dr_zio = zio_write(pio, dmu_objset_spa(dn->dn_objset), dmu_tx_get_txg(tx), &dr->dr_bp_copy, dr->dt.dll.dr_abd, dn->dn_datablksz, abd_get_size(dr->dt.dll.dr_abd), &dr->dt.dll.dr_props, dbuf_lightweight_ready, NULL, dbuf_lightweight_physdone, dbuf_lightweight_done, dr, ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_MUSTSUCCEED | dr->dt.dll.dr_flags, &zb); zio_nowait(dr->dr_zio); } /* * dbuf_sync_leaf() is called recursively from dbuf_sync_list() so it is * critical the we not allow the compiler to inline this function in to * dbuf_sync_list() thereby drastically bloating the stack usage. */ noinline static void dbuf_sync_leaf(dbuf_dirty_record_t *dr, dmu_tx_t *tx) { arc_buf_t **datap = &dr->dt.dl.dr_data; dmu_buf_impl_t *db = dr->dr_dbuf; dnode_t *dn = dr->dr_dnode; objset_t *os; uint64_t txg = tx->tx_txg; ASSERT(dmu_tx_is_syncing(tx)); dprintf_dbuf_bp(db, db->db_blkptr, "blkptr=%p", db->db_blkptr); mutex_enter(&db->db_mtx); /* * To be synced, we must be dirtied. But we * might have been freed after the dirty. */ if (db->db_state == DB_UNCACHED) { /* This buffer has been freed since it was dirtied */ ASSERT(db->db.db_data == NULL); } else if (db->db_state == DB_FILL) { /* This buffer was freed and is now being re-filled */ ASSERT(db->db.db_data != dr->dt.dl.dr_data); } else { ASSERT(db->db_state == DB_CACHED || db->db_state == DB_NOFILL); } DBUF_VERIFY(db); if (db->db_blkid == DMU_SPILL_BLKID) { mutex_enter(&dn->dn_mtx); if (!(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR)) { /* * In the previous transaction group, the bonus buffer * was entirely used to store the attributes for the * dnode which overrode the dn_spill field. However, * when adding more attributes to the file a spill * block was required to hold the extra attributes. * * Make sure to clear the garbage left in the dn_spill * field from the previous attributes in the bonus * buffer. Otherwise, after writing out the spill * block to the new allocated dva, it will free * the old block pointed to by the invalid dn_spill. */ db->db_blkptr = NULL; } dn->dn_phys->dn_flags |= DNODE_FLAG_SPILL_BLKPTR; mutex_exit(&dn->dn_mtx); } /* * If this is a bonus buffer, simply copy the bonus data into the * dnode. It will be written out when the dnode is synced (and it * will be synced, since it must have been dirty for dbuf_sync to * be called). */ if (db->db_blkid == DMU_BONUS_BLKID) { ASSERT(dr->dr_dbuf == db); dbuf_sync_bonus(dr, tx); return; } os = dn->dn_objset; /* * This function may have dropped the db_mtx lock allowing a dmu_sync * operation to sneak in. As a result, we need to ensure that we * don't check the dr_override_state until we have returned from * dbuf_check_blkptr. */ dbuf_check_blkptr(dn, db); /* * If this buffer is in the middle of an immediate write, * wait for the synchronous IO to complete. */ while (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC) { ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT); cv_wait(&db->db_changed, &db->db_mtx); ASSERT(dr->dt.dl.dr_override_state != DR_NOT_OVERRIDDEN); } /* * If this is a dnode block, ensure it is appropriately encrypted * or decrypted, depending on what we are writing to it this txg. */ if (os->os_encrypted && dn->dn_object == DMU_META_DNODE_OBJECT) dbuf_prepare_encrypted_dnode_leaf(dr); if (db->db_state != DB_NOFILL && dn->dn_object != DMU_META_DNODE_OBJECT && zfs_refcount_count(&db->db_holds) > 1 && dr->dt.dl.dr_override_state != DR_OVERRIDDEN && *datap == db->db_buf) { /* * If this buffer is currently "in use" (i.e., there * are active holds and db_data still references it), * then make a copy before we start the write so that * any modifications from the open txg will not leak * into this write. * * NOTE: this copy does not need to be made for * objects only modified in the syncing context (e.g. * DNONE_DNODE blocks). */ *datap = dbuf_alloc_arcbuf_from_arcbuf(db, db->db_buf); bcopy(db->db.db_data, (*datap)->b_data, arc_buf_size(*datap)); } db->db_data_pending = dr; mutex_exit(&db->db_mtx); dbuf_write(dr, *datap, tx); ASSERT(!list_link_active(&dr->dr_dirty_node)); if (dn->dn_object == DMU_META_DNODE_OBJECT) { list_insert_tail(&dn->dn_dirty_records[txg & TXG_MASK], dr); } else { zio_nowait(dr->dr_zio); } } void dbuf_sync_list(list_t *list, int level, dmu_tx_t *tx) { dbuf_dirty_record_t *dr; while ((dr = list_head(list))) { if (dr->dr_zio != NULL) { /* * If we find an already initialized zio then we * are processing the meta-dnode, and we have finished. * The dbufs for all dnodes are put back on the list * during processing, so that we can zio_wait() * these IOs after initiating all child IOs. */ ASSERT3U(dr->dr_dbuf->db.db_object, ==, DMU_META_DNODE_OBJECT); break; } list_remove(list, dr); if (dr->dr_dbuf == NULL) { dbuf_sync_lightweight(dr, tx); } else { if (dr->dr_dbuf->db_blkid != DMU_BONUS_BLKID && dr->dr_dbuf->db_blkid != DMU_SPILL_BLKID) { VERIFY3U(dr->dr_dbuf->db_level, ==, level); } if (dr->dr_dbuf->db_level > 0) dbuf_sync_indirect(dr, tx); else dbuf_sync_leaf(dr, tx); } } } /* ARGSUSED */ static void dbuf_write_ready(zio_t *zio, arc_buf_t *buf, void *vdb) { dmu_buf_impl_t *db = vdb; dnode_t *dn; blkptr_t *bp = zio->io_bp; blkptr_t *bp_orig = &zio->io_bp_orig; spa_t *spa = zio->io_spa; int64_t delta; uint64_t fill = 0; int i; ASSERT3P(db->db_blkptr, !=, NULL); ASSERT3P(&db->db_data_pending->dr_bp_copy, ==, bp); DB_DNODE_ENTER(db); dn = DB_DNODE(db); delta = bp_get_dsize_sync(spa, bp) - bp_get_dsize_sync(spa, bp_orig); dnode_diduse_space(dn, delta - zio->io_prev_space_delta); zio->io_prev_space_delta = delta; if (bp->blk_birth != 0) { ASSERT((db->db_blkid != DMU_SPILL_BLKID && BP_GET_TYPE(bp) == dn->dn_type) || (db->db_blkid == DMU_SPILL_BLKID && BP_GET_TYPE(bp) == dn->dn_bonustype) || BP_IS_EMBEDDED(bp)); ASSERT(BP_GET_LEVEL(bp) == db->db_level); } mutex_enter(&db->db_mtx); #ifdef ZFS_DEBUG if (db->db_blkid == DMU_SPILL_BLKID) { ASSERT(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR); ASSERT(!(BP_IS_HOLE(bp)) && db->db_blkptr == DN_SPILL_BLKPTR(dn->dn_phys)); } #endif if (db->db_level == 0) { mutex_enter(&dn->dn_mtx); if (db->db_blkid > dn->dn_phys->dn_maxblkid && db->db_blkid != DMU_SPILL_BLKID) { ASSERT0(db->db_objset->os_raw_receive); dn->dn_phys->dn_maxblkid = db->db_blkid; } mutex_exit(&dn->dn_mtx); if (dn->dn_type == DMU_OT_DNODE) { i = 0; while (i < db->db.db_size) { dnode_phys_t *dnp = (void *)(((char *)db->db.db_data) + i); i += DNODE_MIN_SIZE; if (dnp->dn_type != DMU_OT_NONE) { fill++; i += dnp->dn_extra_slots * DNODE_MIN_SIZE; } } } else { if (BP_IS_HOLE(bp)) { fill = 0; } else { fill = 1; } } } else { blkptr_t *ibp = db->db.db_data; ASSERT3U(db->db.db_size, ==, 1<dn_phys->dn_indblkshift); for (i = db->db.db_size >> SPA_BLKPTRSHIFT; i > 0; i--, ibp++) { if (BP_IS_HOLE(ibp)) continue; fill += BP_GET_FILL(ibp); } } DB_DNODE_EXIT(db); if (!BP_IS_EMBEDDED(bp)) BP_SET_FILL(bp, fill); mutex_exit(&db->db_mtx); db_lock_type_t dblt = dmu_buf_lock_parent(db, RW_WRITER, FTAG); *db->db_blkptr = *bp; dmu_buf_unlock_parent(db, dblt, FTAG); } /* ARGSUSED */ /* * This function gets called just prior to running through the compression * stage of the zio pipeline. If we're an indirect block comprised of only * holes, then we want this indirect to be compressed away to a hole. In * order to do that we must zero out any information about the holes that * this indirect points to prior to before we try to compress it. */ static void dbuf_write_children_ready(zio_t *zio, arc_buf_t *buf, void *vdb) { dmu_buf_impl_t *db = vdb; dnode_t *dn; blkptr_t *bp; unsigned int epbs, i; ASSERT3U(db->db_level, >, 0); DB_DNODE_ENTER(db); dn = DB_DNODE(db); epbs = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; ASSERT3U(epbs, <, 31); /* Determine if all our children are holes */ for (i = 0, bp = db->db.db_data; i < 1ULL << epbs; i++, bp++) { if (!BP_IS_HOLE(bp)) break; } /* * If all the children are holes, then zero them all out so that * we may get compressed away. */ if (i == 1ULL << epbs) { /* * We only found holes. Grab the rwlock to prevent * anybody from reading the blocks we're about to * zero out. */ rw_enter(&db->db_rwlock, RW_WRITER); bzero(db->db.db_data, db->db.db_size); rw_exit(&db->db_rwlock); } DB_DNODE_EXIT(db); } /* * The SPA will call this callback several times for each zio - once * for every physical child i/o (zio->io_phys_children times). This * allows the DMU to monitor the progress of each logical i/o. For example, * there may be 2 copies of an indirect block, or many fragments of a RAID-Z * block. There may be a long delay before all copies/fragments are completed, * so this callback allows us to retire dirty space gradually, as the physical * i/os complete. */ /* ARGSUSED */ static void dbuf_write_physdone(zio_t *zio, arc_buf_t *buf, void *arg) { dmu_buf_impl_t *db = arg; objset_t *os = db->db_objset; dsl_pool_t *dp = dmu_objset_pool(os); dbuf_dirty_record_t *dr; int delta = 0; dr = db->db_data_pending; ASSERT3U(dr->dr_txg, ==, zio->io_txg); /* * The callback will be called io_phys_children times. Retire one * portion of our dirty space each time we are called. Any rounding * error will be cleaned up by dbuf_write_done(). */ delta = dr->dr_accounted / zio->io_phys_children; dsl_pool_undirty_space(dp, delta, zio->io_txg); } /* ARGSUSED */ static void dbuf_write_done(zio_t *zio, arc_buf_t *buf, void *vdb) { dmu_buf_impl_t *db = vdb; blkptr_t *bp_orig = &zio->io_bp_orig; blkptr_t *bp = db->db_blkptr; objset_t *os = db->db_objset; dmu_tx_t *tx = os->os_synctx; ASSERT0(zio->io_error); ASSERT(db->db_blkptr == bp); /* * For nopwrites and rewrites we ensure that the bp matches our * original and bypass all the accounting. */ if (zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE)) { ASSERT(BP_EQUAL(bp, bp_orig)); } else { dsl_dataset_t *ds = os->os_dsl_dataset; (void) dsl_dataset_block_kill(ds, bp_orig, tx, B_TRUE); dsl_dataset_block_born(ds, bp, tx); } mutex_enter(&db->db_mtx); DBUF_VERIFY(db); dbuf_dirty_record_t *dr = db->db_data_pending; dnode_t *dn = dr->dr_dnode; ASSERT(!list_link_active(&dr->dr_dirty_node)); ASSERT(dr->dr_dbuf == db); ASSERT(list_next(&db->db_dirty_records, dr) == NULL); list_remove(&db->db_dirty_records, dr); #ifdef ZFS_DEBUG if (db->db_blkid == DMU_SPILL_BLKID) { ASSERT(dn->dn_phys->dn_flags & DNODE_FLAG_SPILL_BLKPTR); ASSERT(!(BP_IS_HOLE(db->db_blkptr)) && db->db_blkptr == DN_SPILL_BLKPTR(dn->dn_phys)); } #endif if (db->db_level == 0) { ASSERT(db->db_blkid != DMU_BONUS_BLKID); ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN); if (db->db_state != DB_NOFILL) { if (dr->dt.dl.dr_data != db->db_buf) arc_buf_destroy(dr->dt.dl.dr_data, db); } } else { ASSERT(list_head(&dr->dt.di.dr_children) == NULL); ASSERT3U(db->db.db_size, ==, 1 << dn->dn_phys->dn_indblkshift); if (!BP_IS_HOLE(db->db_blkptr)) { int epbs __maybe_unused = dn->dn_phys->dn_indblkshift - SPA_BLKPTRSHIFT; ASSERT3U(db->db_blkid, <=, dn->dn_phys->dn_maxblkid >> (db->db_level * epbs)); ASSERT3U(BP_GET_LSIZE(db->db_blkptr), ==, db->db.db_size); } mutex_destroy(&dr->dt.di.dr_mtx); list_destroy(&dr->dt.di.dr_children); } cv_broadcast(&db->db_changed); ASSERT(db->db_dirtycnt > 0); db->db_dirtycnt -= 1; db->db_data_pending = NULL; dbuf_rele_and_unlock(db, (void *)(uintptr_t)tx->tx_txg, B_FALSE); /* * If we didn't do a physical write in this ZIO and we * still ended up here, it means that the space of the * dbuf that we just released (and undirtied) above hasn't * been marked as undirtied in the pool's accounting. * * Thus, we undirty that space in the pool's view of the * world here. For physical writes this type of update * happens in dbuf_write_physdone(). * * If we did a physical write, cleanup any rounding errors * that came up due to writing multiple copies of a block * on disk [see dbuf_write_physdone()]. */ if (zio->io_phys_children == 0) { dsl_pool_undirty_space(dmu_objset_pool(os), dr->dr_accounted, zio->io_txg); } else { dsl_pool_undirty_space(dmu_objset_pool(os), dr->dr_accounted % zio->io_phys_children, zio->io_txg); } kmem_free(dr, sizeof (dbuf_dirty_record_t)); } static void dbuf_write_nofill_ready(zio_t *zio) { dbuf_write_ready(zio, NULL, zio->io_private); } static void dbuf_write_nofill_done(zio_t *zio) { dbuf_write_done(zio, NULL, zio->io_private); } static void dbuf_write_override_ready(zio_t *zio) { dbuf_dirty_record_t *dr = zio->io_private; dmu_buf_impl_t *db = dr->dr_dbuf; dbuf_write_ready(zio, NULL, db); } static void dbuf_write_override_done(zio_t *zio) { dbuf_dirty_record_t *dr = zio->io_private; dmu_buf_impl_t *db = dr->dr_dbuf; blkptr_t *obp = &dr->dt.dl.dr_overridden_by; mutex_enter(&db->db_mtx); if (!BP_EQUAL(zio->io_bp, obp)) { if (!BP_IS_HOLE(obp)) dsl_free(spa_get_dsl(zio->io_spa), zio->io_txg, obp); arc_release(dr->dt.dl.dr_data, db); } mutex_exit(&db->db_mtx); dbuf_write_done(zio, NULL, db); if (zio->io_abd != NULL) - abd_put(zio->io_abd); + abd_free(zio->io_abd); } typedef struct dbuf_remap_impl_callback_arg { objset_t *drica_os; uint64_t drica_blk_birth; dmu_tx_t *drica_tx; } dbuf_remap_impl_callback_arg_t; static void dbuf_remap_impl_callback(uint64_t vdev, uint64_t offset, uint64_t size, void *arg) { dbuf_remap_impl_callback_arg_t *drica = arg; objset_t *os = drica->drica_os; spa_t *spa = dmu_objset_spa(os); dmu_tx_t *tx = drica->drica_tx; ASSERT(dsl_pool_sync_context(spa_get_dsl(spa))); if (os == spa_meta_objset(spa)) { spa_vdev_indirect_mark_obsolete(spa, vdev, offset, size, tx); } else { dsl_dataset_block_remapped(dmu_objset_ds(os), vdev, offset, size, drica->drica_blk_birth, tx); } } static void dbuf_remap_impl(dnode_t *dn, blkptr_t *bp, krwlock_t *rw, dmu_tx_t *tx) { blkptr_t bp_copy = *bp; spa_t *spa = dmu_objset_spa(dn->dn_objset); dbuf_remap_impl_callback_arg_t drica; ASSERT(dsl_pool_sync_context(spa_get_dsl(spa))); drica.drica_os = dn->dn_objset; drica.drica_blk_birth = bp->blk_birth; drica.drica_tx = tx; if (spa_remap_blkptr(spa, &bp_copy, dbuf_remap_impl_callback, &drica)) { /* * If the blkptr being remapped is tracked by a livelist, * then we need to make sure the livelist reflects the update. * First, cancel out the old blkptr by appending a 'FREE' * entry. Next, add an 'ALLOC' to track the new version. This * way we avoid trying to free an inaccurate blkptr at delete. * Note that embedded blkptrs are not tracked in livelists. */ if (dn->dn_objset != spa_meta_objset(spa)) { dsl_dataset_t *ds = dmu_objset_ds(dn->dn_objset); if (dsl_deadlist_is_open(&ds->ds_dir->dd_livelist) && bp->blk_birth > ds->ds_dir->dd_origin_txg) { ASSERT(!BP_IS_EMBEDDED(bp)); ASSERT(dsl_dir_is_clone(ds->ds_dir)); ASSERT(spa_feature_is_enabled(spa, SPA_FEATURE_LIVELIST)); bplist_append(&ds->ds_dir->dd_pending_frees, bp); bplist_append(&ds->ds_dir->dd_pending_allocs, &bp_copy); } } /* * The db_rwlock prevents dbuf_read_impl() from * dereferencing the BP while we are changing it. To * avoid lock contention, only grab it when we are actually * changing the BP. */ if (rw != NULL) rw_enter(rw, RW_WRITER); *bp = bp_copy; if (rw != NULL) rw_exit(rw); } } /* * Remap any existing BP's to concrete vdevs, if possible. */ static void dbuf_remap(dnode_t *dn, dmu_buf_impl_t *db, dmu_tx_t *tx) { spa_t *spa = dmu_objset_spa(db->db_objset); ASSERT(dsl_pool_sync_context(spa_get_dsl(spa))); if (!spa_feature_is_active(spa, SPA_FEATURE_DEVICE_REMOVAL)) return; if (db->db_level > 0) { blkptr_t *bp = db->db.db_data; for (int i = 0; i < db->db.db_size >> SPA_BLKPTRSHIFT; i++) { dbuf_remap_impl(dn, &bp[i], &db->db_rwlock, tx); } } else if (db->db.db_object == DMU_META_DNODE_OBJECT) { dnode_phys_t *dnp = db->db.db_data; ASSERT3U(db->db_dnode_handle->dnh_dnode->dn_type, ==, DMU_OT_DNODE); for (int i = 0; i < db->db.db_size >> DNODE_SHIFT; i += dnp[i].dn_extra_slots + 1) { for (int j = 0; j < dnp[i].dn_nblkptr; j++) { krwlock_t *lock = (dn->dn_dbuf == NULL ? NULL : &dn->dn_dbuf->db_rwlock); dbuf_remap_impl(dn, &dnp[i].dn_blkptr[j], lock, tx); } } } } /* Issue I/O to commit a dirty buffer to disk. */ static void dbuf_write(dbuf_dirty_record_t *dr, arc_buf_t *data, dmu_tx_t *tx) { dmu_buf_impl_t *db = dr->dr_dbuf; dnode_t *dn = dr->dr_dnode; objset_t *os; dmu_buf_impl_t *parent = db->db_parent; uint64_t txg = tx->tx_txg; zbookmark_phys_t zb; zio_prop_t zp; zio_t *pio; /* parent I/O */ int wp_flag = 0; ASSERT(dmu_tx_is_syncing(tx)); os = dn->dn_objset; if (db->db_state != DB_NOFILL) { if (db->db_level > 0 || dn->dn_type == DMU_OT_DNODE) { /* * Private object buffers are released here rather * than in dbuf_dirty() since they are only modified * in the syncing context and we don't want the * overhead of making multiple copies of the data. */ if (BP_IS_HOLE(db->db_blkptr)) { arc_buf_thaw(data); } else { dbuf_release_bp(db); } dbuf_remap(dn, db, tx); } } if (parent != dn->dn_dbuf) { /* Our parent is an indirect block. */ /* We have a dirty parent that has been scheduled for write. */ ASSERT(parent && parent->db_data_pending); /* Our parent's buffer is one level closer to the dnode. */ ASSERT(db->db_level == parent->db_level-1); /* * We're about to modify our parent's db_data by modifying * our block pointer, so the parent must be released. */ ASSERT(arc_released(parent->db_buf)); pio = parent->db_data_pending->dr_zio; } else { /* Our parent is the dnode itself. */ ASSERT((db->db_level == dn->dn_phys->dn_nlevels-1 && db->db_blkid != DMU_SPILL_BLKID) || (db->db_blkid == DMU_SPILL_BLKID && db->db_level == 0)); if (db->db_blkid != DMU_SPILL_BLKID) ASSERT3P(db->db_blkptr, ==, &dn->dn_phys->dn_blkptr[db->db_blkid]); pio = dn->dn_zio; } ASSERT(db->db_level == 0 || data == db->db_buf); ASSERT3U(db->db_blkptr->blk_birth, <=, txg); ASSERT(pio); SET_BOOKMARK(&zb, os->os_dsl_dataset ? os->os_dsl_dataset->ds_object : DMU_META_OBJSET, db->db.db_object, db->db_level, db->db_blkid); if (db->db_blkid == DMU_SPILL_BLKID) wp_flag = WP_SPILL; wp_flag |= (db->db_state == DB_NOFILL) ? WP_NOFILL : 0; dmu_write_policy(os, dn, db->db_level, wp_flag, &zp); /* * We copy the blkptr now (rather than when we instantiate the dirty * record), because its value can change between open context and * syncing context. We do not need to hold dn_struct_rwlock to read * db_blkptr because we are in syncing context. */ dr->dr_bp_copy = *db->db_blkptr; if (db->db_level == 0 && dr->dt.dl.dr_override_state == DR_OVERRIDDEN) { /* * The BP for this block has been provided by open context * (by dmu_sync() or dmu_buf_write_embedded()). */ abd_t *contents = (data != NULL) ? abd_get_from_buf(data->b_data, arc_buf_size(data)) : NULL; dr->dr_zio = zio_write(pio, os->os_spa, txg, &dr->dr_bp_copy, contents, db->db.db_size, db->db.db_size, &zp, dbuf_write_override_ready, NULL, NULL, dbuf_write_override_done, dr, ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_MUSTSUCCEED, &zb); mutex_enter(&db->db_mtx); dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN; zio_write_override(dr->dr_zio, &dr->dt.dl.dr_overridden_by, dr->dt.dl.dr_copies, dr->dt.dl.dr_nopwrite); mutex_exit(&db->db_mtx); } else if (db->db_state == DB_NOFILL) { ASSERT(zp.zp_checksum == ZIO_CHECKSUM_OFF || zp.zp_checksum == ZIO_CHECKSUM_NOPARITY); dr->dr_zio = zio_write(pio, os->os_spa, txg, &dr->dr_bp_copy, NULL, db->db.db_size, db->db.db_size, &zp, dbuf_write_nofill_ready, NULL, NULL, dbuf_write_nofill_done, db, ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_MUSTSUCCEED | ZIO_FLAG_NODATA, &zb); } else { ASSERT(arc_released(data)); /* * For indirect blocks, we want to setup the children * ready callback so that we can properly handle an indirect * block that only contains holes. */ arc_write_done_func_t *children_ready_cb = NULL; if (db->db_level != 0) children_ready_cb = dbuf_write_children_ready; dr->dr_zio = arc_write(pio, os->os_spa, txg, &dr->dr_bp_copy, data, DBUF_IS_L2CACHEABLE(db), &zp, dbuf_write_ready, children_ready_cb, dbuf_write_physdone, dbuf_write_done, db, ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_MUSTSUCCEED, &zb); } } EXPORT_SYMBOL(dbuf_find); EXPORT_SYMBOL(dbuf_is_metadata); EXPORT_SYMBOL(dbuf_destroy); EXPORT_SYMBOL(dbuf_loan_arcbuf); EXPORT_SYMBOL(dbuf_whichblock); EXPORT_SYMBOL(dbuf_read); EXPORT_SYMBOL(dbuf_unoverride); EXPORT_SYMBOL(dbuf_free_range); EXPORT_SYMBOL(dbuf_new_size); EXPORT_SYMBOL(dbuf_release_bp); EXPORT_SYMBOL(dbuf_dirty); EXPORT_SYMBOL(dmu_buf_set_crypt_params); EXPORT_SYMBOL(dmu_buf_will_dirty); EXPORT_SYMBOL(dmu_buf_is_dirty); EXPORT_SYMBOL(dmu_buf_will_not_fill); EXPORT_SYMBOL(dmu_buf_will_fill); EXPORT_SYMBOL(dmu_buf_fill_done); EXPORT_SYMBOL(dmu_buf_rele); EXPORT_SYMBOL(dbuf_assign_arcbuf); EXPORT_SYMBOL(dbuf_prefetch); EXPORT_SYMBOL(dbuf_hold_impl); EXPORT_SYMBOL(dbuf_hold); EXPORT_SYMBOL(dbuf_hold_level); EXPORT_SYMBOL(dbuf_create_bonus); EXPORT_SYMBOL(dbuf_spill_set_blksz); EXPORT_SYMBOL(dbuf_rm_spill); EXPORT_SYMBOL(dbuf_add_ref); EXPORT_SYMBOL(dbuf_rele); EXPORT_SYMBOL(dbuf_rele_and_unlock); EXPORT_SYMBOL(dbuf_refcount); EXPORT_SYMBOL(dbuf_sync_list); EXPORT_SYMBOL(dmu_buf_set_user); EXPORT_SYMBOL(dmu_buf_set_user_ie); EXPORT_SYMBOL(dmu_buf_get_user); EXPORT_SYMBOL(dmu_buf_get_blkptr); /* BEGIN CSTYLED */ ZFS_MODULE_PARAM(zfs_dbuf_cache, dbuf_cache_, max_bytes, ULONG, ZMOD_RW, "Maximum size in bytes of the dbuf cache."); ZFS_MODULE_PARAM(zfs_dbuf_cache, dbuf_cache_, hiwater_pct, UINT, ZMOD_RW, "Percentage over dbuf_cache_max_bytes when dbufs must be evicted " "directly."); ZFS_MODULE_PARAM(zfs_dbuf_cache, dbuf_cache_, lowater_pct, UINT, ZMOD_RW, "Percentage below dbuf_cache_max_bytes when the evict thread stops " "evicting dbufs."); ZFS_MODULE_PARAM(zfs_dbuf, dbuf_, metadata_cache_max_bytes, ULONG, ZMOD_RW, "Maximum size in bytes of the dbuf metadata cache."); ZFS_MODULE_PARAM(zfs_dbuf, dbuf_, cache_shift, INT, ZMOD_RW, "Set the size of the dbuf cache to a log2 fraction of arc size."); ZFS_MODULE_PARAM(zfs_dbuf, dbuf_, metadata_cache_shift, INT, ZMOD_RW, "Set the size of the dbuf metadata cache to a log2 fraction of arc " "size."); /* END CSTYLED */ diff --git a/module/zfs/dmu.c b/module/zfs/dmu.c index a02f43df13fd..9c005782fdca 100644 --- a/module/zfs/dmu.c +++ b/module/zfs/dmu.c @@ -1,2341 +1,2341 @@ /* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. * Copyright (c) 2011, 2020 by Delphix. All rights reserved. * Copyright (c) 2013 by Saso Kiselkov. All rights reserved. * Copyright (c) 2013, Joyent, Inc. All rights reserved. * Copyright (c) 2016, Nexenta Systems, Inc. All rights reserved. * Copyright (c) 2015 by Chunwei Chen. All rights reserved. * Copyright (c) 2019 Datto Inc. * Copyright (c) 2019, Klara Inc. * Copyright (c) 2019, Allan Jude */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef _KERNEL #include #include #endif /* * Enable/disable nopwrite feature. */ int zfs_nopwrite_enabled = 1; /* * Tunable to control percentage of dirtied L1 blocks from frees allowed into * one TXG. After this threshold is crossed, additional dirty blocks from frees * will wait until the next TXG. * A value of zero will disable this throttle. */ unsigned long zfs_per_txg_dirty_frees_percent = 5; /* * Enable/disable forcing txg sync when dirty in dmu_offset_next. */ int zfs_dmu_offset_next_sync = 0; /* * Limit the amount we can prefetch with one call to this amount. This * helps to limit the amount of memory that can be used by prefetching. * Larger objects should be prefetched a bit at a time. */ int dmu_prefetch_max = 8 * SPA_MAXBLOCKSIZE; const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES] = { {DMU_BSWAP_UINT8, TRUE, FALSE, FALSE, "unallocated" }, {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "object directory" }, {DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "object array" }, {DMU_BSWAP_UINT8, TRUE, FALSE, FALSE, "packed nvlist" }, {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "packed nvlist size" }, {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "bpobj" }, {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "bpobj header" }, {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "SPA space map header" }, {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "SPA space map" }, {DMU_BSWAP_UINT64, TRUE, FALSE, TRUE, "ZIL intent log" }, {DMU_BSWAP_DNODE, TRUE, FALSE, TRUE, "DMU dnode" }, {DMU_BSWAP_OBJSET, TRUE, TRUE, FALSE, "DMU objset" }, {DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "DSL directory" }, {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL directory child map"}, {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL dataset snap map" }, {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL props" }, {DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "DSL dataset" }, {DMU_BSWAP_ZNODE, TRUE, FALSE, FALSE, "ZFS znode" }, {DMU_BSWAP_OLDACL, TRUE, FALSE, TRUE, "ZFS V0 ACL" }, {DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "ZFS plain file" }, {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS directory" }, {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "ZFS master node" }, {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS delete queue" }, {DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "zvol object" }, {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "zvol prop" }, {DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "other uint8[]" }, {DMU_BSWAP_UINT64, FALSE, FALSE, TRUE, "other uint64[]" }, {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "other ZAP" }, {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "persistent error log" }, {DMU_BSWAP_UINT8, TRUE, FALSE, FALSE, "SPA history" }, {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "SPA history offsets" }, {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "Pool properties" }, {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL permissions" }, {DMU_BSWAP_ACL, TRUE, FALSE, TRUE, "ZFS ACL" }, {DMU_BSWAP_UINT8, TRUE, FALSE, TRUE, "ZFS SYSACL" }, {DMU_BSWAP_UINT8, TRUE, FALSE, TRUE, "FUID table" }, {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "FUID table size" }, {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL dataset next clones"}, {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "scan work queue" }, {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS user/group/project used" }, {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "ZFS user/group/project quota"}, {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "snapshot refcount tags"}, {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "DDT ZAP algorithm" }, {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "DDT statistics" }, {DMU_BSWAP_UINT8, TRUE, FALSE, TRUE, "System attributes" }, {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "SA master node" }, {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "SA attr registration" }, {DMU_BSWAP_ZAP, TRUE, FALSE, TRUE, "SA attr layouts" }, {DMU_BSWAP_ZAP, TRUE, FALSE, FALSE, "scan translations" }, {DMU_BSWAP_UINT8, FALSE, FALSE, TRUE, "deduplicated block" }, {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL deadlist map" }, {DMU_BSWAP_UINT64, TRUE, TRUE, FALSE, "DSL deadlist map hdr" }, {DMU_BSWAP_ZAP, TRUE, TRUE, FALSE, "DSL dir clones" }, {DMU_BSWAP_UINT64, TRUE, FALSE, FALSE, "bpobj subobj" } }; const dmu_object_byteswap_info_t dmu_ot_byteswap[DMU_BSWAP_NUMFUNCS] = { { byteswap_uint8_array, "uint8" }, { byteswap_uint16_array, "uint16" }, { byteswap_uint32_array, "uint32" }, { byteswap_uint64_array, "uint64" }, { zap_byteswap, "zap" }, { dnode_buf_byteswap, "dnode" }, { dmu_objset_byteswap, "objset" }, { zfs_znode_byteswap, "znode" }, { zfs_oldacl_byteswap, "oldacl" }, { zfs_acl_byteswap, "acl" } }; static int dmu_buf_hold_noread_by_dnode(dnode_t *dn, uint64_t offset, void *tag, dmu_buf_t **dbp) { uint64_t blkid; dmu_buf_impl_t *db; rw_enter(&dn->dn_struct_rwlock, RW_READER); blkid = dbuf_whichblock(dn, 0, offset); db = dbuf_hold(dn, blkid, tag); rw_exit(&dn->dn_struct_rwlock); if (db == NULL) { *dbp = NULL; return (SET_ERROR(EIO)); } *dbp = &db->db; return (0); } int dmu_buf_hold_noread(objset_t *os, uint64_t object, uint64_t offset, void *tag, dmu_buf_t **dbp) { dnode_t *dn; uint64_t blkid; dmu_buf_impl_t *db; int err; err = dnode_hold(os, object, FTAG, &dn); if (err) return (err); rw_enter(&dn->dn_struct_rwlock, RW_READER); blkid = dbuf_whichblock(dn, 0, offset); db = dbuf_hold(dn, blkid, tag); rw_exit(&dn->dn_struct_rwlock); dnode_rele(dn, FTAG); if (db == NULL) { *dbp = NULL; return (SET_ERROR(EIO)); } *dbp = &db->db; return (err); } int dmu_buf_hold_by_dnode(dnode_t *dn, uint64_t offset, void *tag, dmu_buf_t **dbp, int flags) { int err; int db_flags = DB_RF_CANFAIL; if (flags & DMU_READ_NO_PREFETCH) db_flags |= DB_RF_NOPREFETCH; if (flags & DMU_READ_NO_DECRYPT) db_flags |= DB_RF_NO_DECRYPT; err = dmu_buf_hold_noread_by_dnode(dn, offset, tag, dbp); if (err == 0) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)(*dbp); err = dbuf_read(db, NULL, db_flags); if (err != 0) { dbuf_rele(db, tag); *dbp = NULL; } } return (err); } int dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset, void *tag, dmu_buf_t **dbp, int flags) { int err; int db_flags = DB_RF_CANFAIL; if (flags & DMU_READ_NO_PREFETCH) db_flags |= DB_RF_NOPREFETCH; if (flags & DMU_READ_NO_DECRYPT) db_flags |= DB_RF_NO_DECRYPT; err = dmu_buf_hold_noread(os, object, offset, tag, dbp); if (err == 0) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)(*dbp); err = dbuf_read(db, NULL, db_flags); if (err != 0) { dbuf_rele(db, tag); *dbp = NULL; } } return (err); } int dmu_bonus_max(void) { return (DN_OLD_MAX_BONUSLEN); } int dmu_set_bonus(dmu_buf_t *db_fake, int newsize, dmu_tx_t *tx) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; dnode_t *dn; int error; DB_DNODE_ENTER(db); dn = DB_DNODE(db); if (dn->dn_bonus != db) { error = SET_ERROR(EINVAL); } else if (newsize < 0 || newsize > db_fake->db_size) { error = SET_ERROR(EINVAL); } else { dnode_setbonuslen(dn, newsize, tx); error = 0; } DB_DNODE_EXIT(db); return (error); } int dmu_set_bonustype(dmu_buf_t *db_fake, dmu_object_type_t type, dmu_tx_t *tx) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; dnode_t *dn; int error; DB_DNODE_ENTER(db); dn = DB_DNODE(db); if (!DMU_OT_IS_VALID(type)) { error = SET_ERROR(EINVAL); } else if (dn->dn_bonus != db) { error = SET_ERROR(EINVAL); } else { dnode_setbonus_type(dn, type, tx); error = 0; } DB_DNODE_EXIT(db); return (error); } dmu_object_type_t dmu_get_bonustype(dmu_buf_t *db_fake) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; dnode_t *dn; dmu_object_type_t type; DB_DNODE_ENTER(db); dn = DB_DNODE(db); type = dn->dn_bonustype; DB_DNODE_EXIT(db); return (type); } int dmu_rm_spill(objset_t *os, uint64_t object, dmu_tx_t *tx) { dnode_t *dn; int error; error = dnode_hold(os, object, FTAG, &dn); dbuf_rm_spill(dn, tx); rw_enter(&dn->dn_struct_rwlock, RW_WRITER); dnode_rm_spill(dn, tx); rw_exit(&dn->dn_struct_rwlock); dnode_rele(dn, FTAG); return (error); } /* * Lookup and hold the bonus buffer for the provided dnode. If the dnode * has not yet been allocated a new bonus dbuf a will be allocated. * Returns ENOENT, EIO, or 0. */ int dmu_bonus_hold_by_dnode(dnode_t *dn, void *tag, dmu_buf_t **dbp, uint32_t flags) { dmu_buf_impl_t *db; int error; uint32_t db_flags = DB_RF_MUST_SUCCEED; if (flags & DMU_READ_NO_PREFETCH) db_flags |= DB_RF_NOPREFETCH; if (flags & DMU_READ_NO_DECRYPT) db_flags |= DB_RF_NO_DECRYPT; rw_enter(&dn->dn_struct_rwlock, RW_READER); if (dn->dn_bonus == NULL) { rw_exit(&dn->dn_struct_rwlock); rw_enter(&dn->dn_struct_rwlock, RW_WRITER); if (dn->dn_bonus == NULL) dbuf_create_bonus(dn); } db = dn->dn_bonus; /* as long as the bonus buf is held, the dnode will be held */ if (zfs_refcount_add(&db->db_holds, tag) == 1) { VERIFY(dnode_add_ref(dn, db)); atomic_inc_32(&dn->dn_dbufs_count); } /* * Wait to drop dn_struct_rwlock until after adding the bonus dbuf's * hold and incrementing the dbuf count to ensure that dnode_move() sees * a dnode hold for every dbuf. */ rw_exit(&dn->dn_struct_rwlock); error = dbuf_read(db, NULL, db_flags); if (error) { dnode_evict_bonus(dn); dbuf_rele(db, tag); *dbp = NULL; return (error); } *dbp = &db->db; return (0); } int dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **dbp) { dnode_t *dn; int error; error = dnode_hold(os, object, FTAG, &dn); if (error) return (error); error = dmu_bonus_hold_by_dnode(dn, tag, dbp, DMU_READ_NO_PREFETCH); dnode_rele(dn, FTAG); return (error); } /* * returns ENOENT, EIO, or 0. * * This interface will allocate a blank spill dbuf when a spill blk * doesn't already exist on the dnode. * * if you only want to find an already existing spill db, then * dmu_spill_hold_existing() should be used. */ int dmu_spill_hold_by_dnode(dnode_t *dn, uint32_t flags, void *tag, dmu_buf_t **dbp) { dmu_buf_impl_t *db = NULL; int err; if ((flags & DB_RF_HAVESTRUCT) == 0) rw_enter(&dn->dn_struct_rwlock, RW_READER); db = dbuf_hold(dn, DMU_SPILL_BLKID, tag); if ((flags & DB_RF_HAVESTRUCT) == 0) rw_exit(&dn->dn_struct_rwlock); if (db == NULL) { *dbp = NULL; return (SET_ERROR(EIO)); } err = dbuf_read(db, NULL, flags); if (err == 0) *dbp = &db->db; else { dbuf_rele(db, tag); *dbp = NULL; } return (err); } int dmu_spill_hold_existing(dmu_buf_t *bonus, void *tag, dmu_buf_t **dbp) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus; dnode_t *dn; int err; DB_DNODE_ENTER(db); dn = DB_DNODE(db); if (spa_version(dn->dn_objset->os_spa) < SPA_VERSION_SA) { err = SET_ERROR(EINVAL); } else { rw_enter(&dn->dn_struct_rwlock, RW_READER); if (!dn->dn_have_spill) { err = SET_ERROR(ENOENT); } else { err = dmu_spill_hold_by_dnode(dn, DB_RF_HAVESTRUCT | DB_RF_CANFAIL, tag, dbp); } rw_exit(&dn->dn_struct_rwlock); } DB_DNODE_EXIT(db); return (err); } int dmu_spill_hold_by_bonus(dmu_buf_t *bonus, uint32_t flags, void *tag, dmu_buf_t **dbp) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)bonus; dnode_t *dn; int err; uint32_t db_flags = DB_RF_CANFAIL; if (flags & DMU_READ_NO_DECRYPT) db_flags |= DB_RF_NO_DECRYPT; DB_DNODE_ENTER(db); dn = DB_DNODE(db); err = dmu_spill_hold_by_dnode(dn, db_flags, tag, dbp); DB_DNODE_EXIT(db); return (err); } /* * Note: longer-term, we should modify all of the dmu_buf_*() interfaces * to take a held dnode rather than -- the lookup is wasteful, * and can induce severe lock contention when writing to several files * whose dnodes are in the same block. */ int dmu_buf_hold_array_by_dnode(dnode_t *dn, uint64_t offset, uint64_t length, boolean_t read, void *tag, int *numbufsp, dmu_buf_t ***dbpp, uint32_t flags) { dmu_buf_t **dbp; uint64_t blkid, nblks, i; uint32_t dbuf_flags; int err; zio_t *zio = NULL; ASSERT(length <= DMU_MAX_ACCESS); /* * Note: We directly notify the prefetch code of this read, so that * we can tell it about the multi-block read. dbuf_read() only knows * about the one block it is accessing. */ dbuf_flags = DB_RF_CANFAIL | DB_RF_NEVERWAIT | DB_RF_HAVESTRUCT | DB_RF_NOPREFETCH; rw_enter(&dn->dn_struct_rwlock, RW_READER); if (dn->dn_datablkshift) { int blkshift = dn->dn_datablkshift; nblks = (P2ROUNDUP(offset + length, 1ULL << blkshift) - P2ALIGN(offset, 1ULL << blkshift)) >> blkshift; } else { if (offset + length > dn->dn_datablksz) { zfs_panic_recover("zfs: accessing past end of object " "%llx/%llx (size=%u access=%llu+%llu)", (longlong_t)dn->dn_objset-> os_dsl_dataset->ds_object, (longlong_t)dn->dn_object, dn->dn_datablksz, (longlong_t)offset, (longlong_t)length); rw_exit(&dn->dn_struct_rwlock); return (SET_ERROR(EIO)); } nblks = 1; } dbp = kmem_zalloc(sizeof (dmu_buf_t *) * nblks, KM_SLEEP); if (read) zio = zio_root(dn->dn_objset->os_spa, NULL, NULL, ZIO_FLAG_CANFAIL); blkid = dbuf_whichblock(dn, 0, offset); for (i = 0; i < nblks; i++) { dmu_buf_impl_t *db = dbuf_hold(dn, blkid + i, tag); if (db == NULL) { rw_exit(&dn->dn_struct_rwlock); dmu_buf_rele_array(dbp, nblks, tag); if (read) zio_nowait(zio); return (SET_ERROR(EIO)); } /* initiate async i/o */ if (read) (void) dbuf_read(db, zio, dbuf_flags); dbp[i] = &db->db; } if ((flags & DMU_READ_NO_PREFETCH) == 0 && DNODE_META_IS_CACHEABLE(dn) && length <= zfetch_array_rd_sz) { dmu_zfetch(&dn->dn_zfetch, blkid, nblks, read && DNODE_IS_CACHEABLE(dn), B_TRUE); } rw_exit(&dn->dn_struct_rwlock); if (read) { /* wait for async read i/o */ err = zio_wait(zio); if (err) { dmu_buf_rele_array(dbp, nblks, tag); return (err); } /* wait for other io to complete */ for (i = 0; i < nblks; i++) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)dbp[i]; mutex_enter(&db->db_mtx); while (db->db_state == DB_READ || db->db_state == DB_FILL) cv_wait(&db->db_changed, &db->db_mtx); if (db->db_state == DB_UNCACHED) err = SET_ERROR(EIO); mutex_exit(&db->db_mtx); if (err) { dmu_buf_rele_array(dbp, nblks, tag); return (err); } } } *numbufsp = nblks; *dbpp = dbp; return (0); } static int dmu_buf_hold_array(objset_t *os, uint64_t object, uint64_t offset, uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp) { dnode_t *dn; int err; err = dnode_hold(os, object, FTAG, &dn); if (err) return (err); err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag, numbufsp, dbpp, DMU_READ_PREFETCH); dnode_rele(dn, FTAG); return (err); } int dmu_buf_hold_array_by_bonus(dmu_buf_t *db_fake, uint64_t offset, uint64_t length, boolean_t read, void *tag, int *numbufsp, dmu_buf_t ***dbpp) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; dnode_t *dn; int err; DB_DNODE_ENTER(db); dn = DB_DNODE(db); err = dmu_buf_hold_array_by_dnode(dn, offset, length, read, tag, numbufsp, dbpp, DMU_READ_PREFETCH); DB_DNODE_EXIT(db); return (err); } void dmu_buf_rele_array(dmu_buf_t **dbp_fake, int numbufs, void *tag) { int i; dmu_buf_impl_t **dbp = (dmu_buf_impl_t **)dbp_fake; if (numbufs == 0) return; for (i = 0; i < numbufs; i++) { if (dbp[i]) dbuf_rele(dbp[i], tag); } kmem_free(dbp, sizeof (dmu_buf_t *) * numbufs); } /* * Issue prefetch i/os for the given blocks. If level is greater than 0, the * indirect blocks prefetched will be those that point to the blocks containing * the data starting at offset, and continuing to offset + len. * * Note that if the indirect blocks above the blocks being prefetched are not * in cache, they will be asynchronously read in. */ void dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset, uint64_t len, zio_priority_t pri) { dnode_t *dn; uint64_t blkid; int nblks, err; if (len == 0) { /* they're interested in the bonus buffer */ dn = DMU_META_DNODE(os); if (object == 0 || object >= DN_MAX_OBJECT) return; rw_enter(&dn->dn_struct_rwlock, RW_READER); blkid = dbuf_whichblock(dn, level, object * sizeof (dnode_phys_t)); dbuf_prefetch(dn, level, blkid, pri, 0); rw_exit(&dn->dn_struct_rwlock); return; } /* * See comment before the definition of dmu_prefetch_max. */ len = MIN(len, dmu_prefetch_max); /* * XXX - Note, if the dnode for the requested object is not * already cached, we will do a *synchronous* read in the * dnode_hold() call. The same is true for any indirects. */ err = dnode_hold(os, object, FTAG, &dn); if (err != 0) return; /* * offset + len - 1 is the last byte we want to prefetch for, and offset * is the first. Then dbuf_whichblk(dn, level, off + len - 1) is the * last block we want to prefetch, and dbuf_whichblock(dn, level, * offset) is the first. Then the number we need to prefetch is the * last - first + 1. */ rw_enter(&dn->dn_struct_rwlock, RW_READER); if (level > 0 || dn->dn_datablkshift != 0) { nblks = dbuf_whichblock(dn, level, offset + len - 1) - dbuf_whichblock(dn, level, offset) + 1; } else { nblks = (offset < dn->dn_datablksz); } if (nblks != 0) { blkid = dbuf_whichblock(dn, level, offset); for (int i = 0; i < nblks; i++) dbuf_prefetch(dn, level, blkid + i, pri, 0); } rw_exit(&dn->dn_struct_rwlock); dnode_rele(dn, FTAG); } /* * Get the next "chunk" of file data to free. We traverse the file from * the end so that the file gets shorter over time (if we crashes in the * middle, this will leave us in a better state). We find allocated file * data by simply searching the allocated level 1 indirects. * * On input, *start should be the first offset that does not need to be * freed (e.g. "offset + length"). On return, *start will be the first * offset that should be freed and l1blks is set to the number of level 1 * indirect blocks found within the chunk. */ static int get_next_chunk(dnode_t *dn, uint64_t *start, uint64_t minimum, uint64_t *l1blks) { uint64_t blks; uint64_t maxblks = DMU_MAX_ACCESS >> (dn->dn_indblkshift + 1); /* bytes of data covered by a level-1 indirect block */ uint64_t iblkrange = (uint64_t)dn->dn_datablksz * EPB(dn->dn_indblkshift, SPA_BLKPTRSHIFT); ASSERT3U(minimum, <=, *start); /* * Check if we can free the entire range assuming that all of the * L1 blocks in this range have data. If we can, we use this * worst case value as an estimate so we can avoid having to look * at the object's actual data. */ uint64_t total_l1blks = (roundup(*start, iblkrange) - (minimum / iblkrange * iblkrange)) / iblkrange; if (total_l1blks <= maxblks) { *l1blks = total_l1blks; *start = minimum; return (0); } ASSERT(ISP2(iblkrange)); for (blks = 0; *start > minimum && blks < maxblks; blks++) { int err; /* * dnode_next_offset(BACKWARDS) will find an allocated L1 * indirect block at or before the input offset. We must * decrement *start so that it is at the end of the region * to search. */ (*start)--; err = dnode_next_offset(dn, DNODE_FIND_BACKWARDS, start, 2, 1, 0); /* if there are no indirect blocks before start, we are done */ if (err == ESRCH) { *start = minimum; break; } else if (err != 0) { *l1blks = blks; return (err); } /* set start to the beginning of this L1 indirect */ *start = P2ALIGN(*start, iblkrange); } if (*start < minimum) *start = minimum; *l1blks = blks; return (0); } /* * If this objset is of type OST_ZFS return true if vfs's unmounted flag is set, * otherwise return false. * Used below in dmu_free_long_range_impl() to enable abort when unmounting */ /*ARGSUSED*/ static boolean_t dmu_objset_zfs_unmounting(objset_t *os) { #ifdef _KERNEL if (dmu_objset_type(os) == DMU_OST_ZFS) return (zfs_get_vfs_flag_unmounted(os)); #endif return (B_FALSE); } static int dmu_free_long_range_impl(objset_t *os, dnode_t *dn, uint64_t offset, uint64_t length) { uint64_t object_size; int err; uint64_t dirty_frees_threshold; dsl_pool_t *dp = dmu_objset_pool(os); if (dn == NULL) return (SET_ERROR(EINVAL)); object_size = (dn->dn_maxblkid + 1) * dn->dn_datablksz; if (offset >= object_size) return (0); if (zfs_per_txg_dirty_frees_percent <= 100) dirty_frees_threshold = zfs_per_txg_dirty_frees_percent * zfs_dirty_data_max / 100; else dirty_frees_threshold = zfs_dirty_data_max / 20; if (length == DMU_OBJECT_END || offset + length > object_size) length = object_size - offset; while (length != 0) { uint64_t chunk_end, chunk_begin, chunk_len; uint64_t l1blks; dmu_tx_t *tx; if (dmu_objset_zfs_unmounting(dn->dn_objset)) return (SET_ERROR(EINTR)); chunk_end = chunk_begin = offset + length; /* move chunk_begin backwards to the beginning of this chunk */ err = get_next_chunk(dn, &chunk_begin, offset, &l1blks); if (err) return (err); ASSERT3U(chunk_begin, >=, offset); ASSERT3U(chunk_begin, <=, chunk_end); chunk_len = chunk_end - chunk_begin; tx = dmu_tx_create(os); dmu_tx_hold_free(tx, dn->dn_object, chunk_begin, chunk_len); /* * Mark this transaction as typically resulting in a net * reduction in space used. */ dmu_tx_mark_netfree(tx); err = dmu_tx_assign(tx, TXG_WAIT); if (err) { dmu_tx_abort(tx); return (err); } uint64_t txg = dmu_tx_get_txg(tx); mutex_enter(&dp->dp_lock); uint64_t long_free_dirty = dp->dp_long_free_dirty_pertxg[txg & TXG_MASK]; mutex_exit(&dp->dp_lock); /* * To avoid filling up a TXG with just frees, wait for * the next TXG to open before freeing more chunks if * we have reached the threshold of frees. */ if (dirty_frees_threshold != 0 && long_free_dirty >= dirty_frees_threshold) { DMU_TX_STAT_BUMP(dmu_tx_dirty_frees_delay); dmu_tx_commit(tx); txg_wait_open(dp, 0, B_TRUE); continue; } /* * In order to prevent unnecessary write throttling, for each * TXG, we track the cumulative size of L1 blocks being dirtied * in dnode_free_range() below. We compare this number to a * tunable threshold, past which we prevent new L1 dirty freeing * blocks from being added into the open TXG. See * dmu_free_long_range_impl() for details. The threshold * prevents write throttle activation due to dirty freeing L1 * blocks taking up a large percentage of zfs_dirty_data_max. */ mutex_enter(&dp->dp_lock); dp->dp_long_free_dirty_pertxg[txg & TXG_MASK] += l1blks << dn->dn_indblkshift; mutex_exit(&dp->dp_lock); DTRACE_PROBE3(free__long__range, uint64_t, long_free_dirty, uint64_t, chunk_len, uint64_t, txg); dnode_free_range(dn, chunk_begin, chunk_len, tx); dmu_tx_commit(tx); length -= chunk_len; } return (0); } int dmu_free_long_range(objset_t *os, uint64_t object, uint64_t offset, uint64_t length) { dnode_t *dn; int err; err = dnode_hold(os, object, FTAG, &dn); if (err != 0) return (err); err = dmu_free_long_range_impl(os, dn, offset, length); /* * It is important to zero out the maxblkid when freeing the entire * file, so that (a) subsequent calls to dmu_free_long_range_impl() * will take the fast path, and (b) dnode_reallocate() can verify * that the entire file has been freed. */ if (err == 0 && offset == 0 && length == DMU_OBJECT_END) dn->dn_maxblkid = 0; dnode_rele(dn, FTAG); return (err); } int dmu_free_long_object(objset_t *os, uint64_t object) { dmu_tx_t *tx; int err; err = dmu_free_long_range(os, object, 0, DMU_OBJECT_END); if (err != 0) return (err); tx = dmu_tx_create(os); dmu_tx_hold_bonus(tx, object); dmu_tx_hold_free(tx, object, 0, DMU_OBJECT_END); dmu_tx_mark_netfree(tx); err = dmu_tx_assign(tx, TXG_WAIT); if (err == 0) { if (err == 0) err = dmu_object_free(os, object, tx); dmu_tx_commit(tx); } else { dmu_tx_abort(tx); } return (err); } int dmu_free_range(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, dmu_tx_t *tx) { dnode_t *dn; int err = dnode_hold(os, object, FTAG, &dn); if (err) return (err); ASSERT(offset < UINT64_MAX); ASSERT(size == DMU_OBJECT_END || size <= UINT64_MAX - offset); dnode_free_range(dn, offset, size, tx); dnode_rele(dn, FTAG); return (0); } static int dmu_read_impl(dnode_t *dn, uint64_t offset, uint64_t size, void *buf, uint32_t flags) { dmu_buf_t **dbp; int numbufs, err = 0; /* * Deal with odd block sizes, where there can't be data past the first * block. If we ever do the tail block optimization, we will need to * handle that here as well. */ if (dn->dn_maxblkid == 0) { uint64_t newsz = offset > dn->dn_datablksz ? 0 : MIN(size, dn->dn_datablksz - offset); bzero((char *)buf + newsz, size - newsz); size = newsz; } while (size > 0) { uint64_t mylen = MIN(size, DMU_MAX_ACCESS / 2); int i; /* * NB: we could do this block-at-a-time, but it's nice * to be reading in parallel. */ err = dmu_buf_hold_array_by_dnode(dn, offset, mylen, TRUE, FTAG, &numbufs, &dbp, flags); if (err) break; for (i = 0; i < numbufs; i++) { uint64_t tocpy; int64_t bufoff; dmu_buf_t *db = dbp[i]; ASSERT(size > 0); bufoff = offset - db->db_offset; tocpy = MIN(db->db_size - bufoff, size); (void) memcpy(buf, (char *)db->db_data + bufoff, tocpy); offset += tocpy; size -= tocpy; buf = (char *)buf + tocpy; } dmu_buf_rele_array(dbp, numbufs, FTAG); } return (err); } int dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, void *buf, uint32_t flags) { dnode_t *dn; int err; err = dnode_hold(os, object, FTAG, &dn); if (err != 0) return (err); err = dmu_read_impl(dn, offset, size, buf, flags); dnode_rele(dn, FTAG); return (err); } int dmu_read_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size, void *buf, uint32_t flags) { return (dmu_read_impl(dn, offset, size, buf, flags)); } static void dmu_write_impl(dmu_buf_t **dbp, int numbufs, uint64_t offset, uint64_t size, const void *buf, dmu_tx_t *tx) { int i; for (i = 0; i < numbufs; i++) { uint64_t tocpy; int64_t bufoff; dmu_buf_t *db = dbp[i]; ASSERT(size > 0); bufoff = offset - db->db_offset; tocpy = MIN(db->db_size - bufoff, size); ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size); if (tocpy == db->db_size) dmu_buf_will_fill(db, tx); else dmu_buf_will_dirty(db, tx); (void) memcpy((char *)db->db_data + bufoff, buf, tocpy); if (tocpy == db->db_size) dmu_buf_fill_done(db, tx); offset += tocpy; size -= tocpy; buf = (char *)buf + tocpy; } } void dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, const void *buf, dmu_tx_t *tx) { dmu_buf_t **dbp; int numbufs; if (size == 0) return; VERIFY0(dmu_buf_hold_array(os, object, offset, size, FALSE, FTAG, &numbufs, &dbp)); dmu_write_impl(dbp, numbufs, offset, size, buf, tx); dmu_buf_rele_array(dbp, numbufs, FTAG); } /* * Note: Lustre is an external consumer of this interface. */ void dmu_write_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size, const void *buf, dmu_tx_t *tx) { dmu_buf_t **dbp; int numbufs; if (size == 0) return; VERIFY0(dmu_buf_hold_array_by_dnode(dn, offset, size, FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH)); dmu_write_impl(dbp, numbufs, offset, size, buf, tx); dmu_buf_rele_array(dbp, numbufs, FTAG); } void dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, dmu_tx_t *tx) { dmu_buf_t **dbp; int numbufs, i; if (size == 0) return; VERIFY(0 == dmu_buf_hold_array(os, object, offset, size, FALSE, FTAG, &numbufs, &dbp)); for (i = 0; i < numbufs; i++) { dmu_buf_t *db = dbp[i]; dmu_buf_will_not_fill(db, tx); } dmu_buf_rele_array(dbp, numbufs, FTAG); } void dmu_write_embedded(objset_t *os, uint64_t object, uint64_t offset, void *data, uint8_t etype, uint8_t comp, int uncompressed_size, int compressed_size, int byteorder, dmu_tx_t *tx) { dmu_buf_t *db; ASSERT3U(etype, <, NUM_BP_EMBEDDED_TYPES); ASSERT3U(comp, <, ZIO_COMPRESS_FUNCTIONS); VERIFY0(dmu_buf_hold_noread(os, object, offset, FTAG, &db)); dmu_buf_write_embedded(db, data, (bp_embedded_type_t)etype, (enum zio_compress)comp, uncompressed_size, compressed_size, byteorder, tx); dmu_buf_rele(db, FTAG); } void dmu_redact(objset_t *os, uint64_t object, uint64_t offset, uint64_t size, dmu_tx_t *tx) { int numbufs, i; dmu_buf_t **dbp; VERIFY0(dmu_buf_hold_array(os, object, offset, size, FALSE, FTAG, &numbufs, &dbp)); for (i = 0; i < numbufs; i++) dmu_buf_redact(dbp[i], tx); dmu_buf_rele_array(dbp, numbufs, FTAG); } #ifdef _KERNEL int dmu_read_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size) { dmu_buf_t **dbp; int numbufs, i, err; /* * NB: we could do this block-at-a-time, but it's nice * to be reading in parallel. */ err = dmu_buf_hold_array_by_dnode(dn, uio_offset(uio), size, TRUE, FTAG, &numbufs, &dbp, 0); if (err) return (err); for (i = 0; i < numbufs; i++) { uint64_t tocpy; int64_t bufoff; dmu_buf_t *db = dbp[i]; ASSERT(size > 0); bufoff = uio_offset(uio) - db->db_offset; tocpy = MIN(db->db_size - bufoff, size); #ifdef __FreeBSD__ err = vn_io_fault_uiomove((char *)db->db_data + bufoff, tocpy, uio); #else err = uiomove((char *)db->db_data + bufoff, tocpy, UIO_READ, uio); #endif if (err) break; size -= tocpy; } dmu_buf_rele_array(dbp, numbufs, FTAG); return (err); } /* * Read 'size' bytes into the uio buffer. * From object zdb->db_object. * Starting at offset uio->uio_loffset. * * If the caller already has a dbuf in the target object * (e.g. its bonus buffer), this routine is faster than dmu_read_uio(), * because we don't have to find the dnode_t for the object. */ int dmu_read_uio_dbuf(dmu_buf_t *zdb, uio_t *uio, uint64_t size) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb; dnode_t *dn; int err; if (size == 0) return (0); DB_DNODE_ENTER(db); dn = DB_DNODE(db); err = dmu_read_uio_dnode(dn, uio, size); DB_DNODE_EXIT(db); return (err); } /* * Read 'size' bytes into the uio buffer. * From the specified object * Starting at offset uio->uio_loffset. */ int dmu_read_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size) { dnode_t *dn; int err; if (size == 0) return (0); err = dnode_hold(os, object, FTAG, &dn); if (err) return (err); err = dmu_read_uio_dnode(dn, uio, size); dnode_rele(dn, FTAG); return (err); } int dmu_write_uio_dnode(dnode_t *dn, uio_t *uio, uint64_t size, dmu_tx_t *tx) { dmu_buf_t **dbp; int numbufs; int err = 0; int i; err = dmu_buf_hold_array_by_dnode(dn, uio_offset(uio), size, FALSE, FTAG, &numbufs, &dbp, DMU_READ_PREFETCH); if (err) return (err); for (i = 0; i < numbufs; i++) { uint64_t tocpy; int64_t bufoff; dmu_buf_t *db = dbp[i]; ASSERT(size > 0); bufoff = uio_offset(uio) - db->db_offset; tocpy = MIN(db->db_size - bufoff, size); ASSERT(i == 0 || i == numbufs-1 || tocpy == db->db_size); if (tocpy == db->db_size) dmu_buf_will_fill(db, tx); else dmu_buf_will_dirty(db, tx); /* * XXX uiomove could block forever (eg.nfs-backed * pages). There needs to be a uiolockdown() function * to lock the pages in memory, so that uiomove won't * block. */ #ifdef __FreeBSD__ err = vn_io_fault_uiomove((char *)db->db_data + bufoff, tocpy, uio); #else err = uiomove((char *)db->db_data + bufoff, tocpy, UIO_WRITE, uio); #endif if (tocpy == db->db_size) dmu_buf_fill_done(db, tx); if (err) break; size -= tocpy; } dmu_buf_rele_array(dbp, numbufs, FTAG); return (err); } /* * Write 'size' bytes from the uio buffer. * To object zdb->db_object. * Starting at offset uio->uio_loffset. * * If the caller already has a dbuf in the target object * (e.g. its bonus buffer), this routine is faster than dmu_write_uio(), * because we don't have to find the dnode_t for the object. */ int dmu_write_uio_dbuf(dmu_buf_t *zdb, uio_t *uio, uint64_t size, dmu_tx_t *tx) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)zdb; dnode_t *dn; int err; if (size == 0) return (0); DB_DNODE_ENTER(db); dn = DB_DNODE(db); err = dmu_write_uio_dnode(dn, uio, size, tx); DB_DNODE_EXIT(db); return (err); } /* * Write 'size' bytes from the uio buffer. * To the specified object. * Starting at offset uio->uio_loffset. */ int dmu_write_uio(objset_t *os, uint64_t object, uio_t *uio, uint64_t size, dmu_tx_t *tx) { dnode_t *dn; int err; if (size == 0) return (0); err = dnode_hold(os, object, FTAG, &dn); if (err) return (err); err = dmu_write_uio_dnode(dn, uio, size, tx); dnode_rele(dn, FTAG); return (err); } #endif /* _KERNEL */ /* * Allocate a loaned anonymous arc buffer. */ arc_buf_t * dmu_request_arcbuf(dmu_buf_t *handle, int size) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)handle; return (arc_loan_buf(db->db_objset->os_spa, B_FALSE, size)); } /* * Free a loaned arc buffer. */ void dmu_return_arcbuf(arc_buf_t *buf) { arc_return_buf(buf, FTAG); arc_buf_destroy(buf, FTAG); } /* * A "lightweight" write is faster than a regular write (e.g. * dmu_write_by_dnode() or dmu_assign_arcbuf_by_dnode()), because it avoids the * CPU cost of creating a dmu_buf_impl_t and arc_buf_[hdr_]_t. However, the * data can not be read or overwritten until the transaction's txg has been * synced. This makes it appropriate for workloads that are known to be * (temporarily) write-only, like "zfs receive". * * A single block is written, starting at the specified offset in bytes. If * the call is successful, it returns 0 and the provided abd has been * consumed (the caller should not free it). */ int dmu_lightweight_write_by_dnode(dnode_t *dn, uint64_t offset, abd_t *abd, const zio_prop_t *zp, enum zio_flag flags, dmu_tx_t *tx) { dbuf_dirty_record_t *dr = dbuf_dirty_lightweight(dn, dbuf_whichblock(dn, 0, offset), tx); if (dr == NULL) return (SET_ERROR(EIO)); dr->dt.dll.dr_abd = abd; dr->dt.dll.dr_props = *zp; dr->dt.dll.dr_flags = flags; return (0); } /* * When possible directly assign passed loaned arc buffer to a dbuf. * If this is not possible copy the contents of passed arc buf via * dmu_write(). */ int dmu_assign_arcbuf_by_dnode(dnode_t *dn, uint64_t offset, arc_buf_t *buf, dmu_tx_t *tx) { dmu_buf_impl_t *db; objset_t *os = dn->dn_objset; uint64_t object = dn->dn_object; uint32_t blksz = (uint32_t)arc_buf_lsize(buf); uint64_t blkid; rw_enter(&dn->dn_struct_rwlock, RW_READER); blkid = dbuf_whichblock(dn, 0, offset); db = dbuf_hold(dn, blkid, FTAG); if (db == NULL) return (SET_ERROR(EIO)); rw_exit(&dn->dn_struct_rwlock); /* * We can only assign if the offset is aligned and the arc buf is the * same size as the dbuf. */ if (offset == db->db.db_offset && blksz == db->db.db_size) { dbuf_assign_arcbuf(db, buf, tx); dbuf_rele(db, FTAG); } else { /* compressed bufs must always be assignable to their dbuf */ ASSERT3U(arc_get_compression(buf), ==, ZIO_COMPRESS_OFF); ASSERT(!(buf->b_flags & ARC_BUF_FLAG_COMPRESSED)); dbuf_rele(db, FTAG); dmu_write(os, object, offset, blksz, buf->b_data, tx); dmu_return_arcbuf(buf); } return (0); } int dmu_assign_arcbuf_by_dbuf(dmu_buf_t *handle, uint64_t offset, arc_buf_t *buf, dmu_tx_t *tx) { int err; dmu_buf_impl_t *dbuf = (dmu_buf_impl_t *)handle; DB_DNODE_ENTER(dbuf); err = dmu_assign_arcbuf_by_dnode(DB_DNODE(dbuf), offset, buf, tx); DB_DNODE_EXIT(dbuf); return (err); } typedef struct { dbuf_dirty_record_t *dsa_dr; dmu_sync_cb_t *dsa_done; zgd_t *dsa_zgd; dmu_tx_t *dsa_tx; } dmu_sync_arg_t; /* ARGSUSED */ static void dmu_sync_ready(zio_t *zio, arc_buf_t *buf, void *varg) { dmu_sync_arg_t *dsa = varg; dmu_buf_t *db = dsa->dsa_zgd->zgd_db; blkptr_t *bp = zio->io_bp; if (zio->io_error == 0) { if (BP_IS_HOLE(bp)) { /* * A block of zeros may compress to a hole, but the * block size still needs to be known for replay. */ BP_SET_LSIZE(bp, db->db_size); } else if (!BP_IS_EMBEDDED(bp)) { ASSERT(BP_GET_LEVEL(bp) == 0); BP_SET_FILL(bp, 1); } } } static void dmu_sync_late_arrival_ready(zio_t *zio) { dmu_sync_ready(zio, NULL, zio->io_private); } /* ARGSUSED */ static void dmu_sync_done(zio_t *zio, arc_buf_t *buf, void *varg) { dmu_sync_arg_t *dsa = varg; dbuf_dirty_record_t *dr = dsa->dsa_dr; dmu_buf_impl_t *db = dr->dr_dbuf; zgd_t *zgd = dsa->dsa_zgd; /* * Record the vdev(s) backing this blkptr so they can be flushed after * the writes for the lwb have completed. */ if (zio->io_error == 0) { zil_lwb_add_block(zgd->zgd_lwb, zgd->zgd_bp); } mutex_enter(&db->db_mtx); ASSERT(dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC); if (zio->io_error == 0) { dr->dt.dl.dr_nopwrite = !!(zio->io_flags & ZIO_FLAG_NOPWRITE); if (dr->dt.dl.dr_nopwrite) { blkptr_t *bp = zio->io_bp; blkptr_t *bp_orig = &zio->io_bp_orig; uint8_t chksum = BP_GET_CHECKSUM(bp_orig); ASSERT(BP_EQUAL(bp, bp_orig)); VERIFY(BP_EQUAL(bp, db->db_blkptr)); ASSERT(zio->io_prop.zp_compress != ZIO_COMPRESS_OFF); VERIFY(zio_checksum_table[chksum].ci_flags & ZCHECKSUM_FLAG_NOPWRITE); } dr->dt.dl.dr_overridden_by = *zio->io_bp; dr->dt.dl.dr_override_state = DR_OVERRIDDEN; dr->dt.dl.dr_copies = zio->io_prop.zp_copies; /* * Old style holes are filled with all zeros, whereas * new-style holes maintain their lsize, type, level, * and birth time (see zio_write_compress). While we * need to reset the BP_SET_LSIZE() call that happened * in dmu_sync_ready for old style holes, we do *not* * want to wipe out the information contained in new * style holes. Thus, only zero out the block pointer if * it's an old style hole. */ if (BP_IS_HOLE(&dr->dt.dl.dr_overridden_by) && dr->dt.dl.dr_overridden_by.blk_birth == 0) BP_ZERO(&dr->dt.dl.dr_overridden_by); } else { dr->dt.dl.dr_override_state = DR_NOT_OVERRIDDEN; } cv_broadcast(&db->db_changed); mutex_exit(&db->db_mtx); dsa->dsa_done(dsa->dsa_zgd, zio->io_error); kmem_free(dsa, sizeof (*dsa)); } static void dmu_sync_late_arrival_done(zio_t *zio) { blkptr_t *bp = zio->io_bp; dmu_sync_arg_t *dsa = zio->io_private; zgd_t *zgd = dsa->dsa_zgd; if (zio->io_error == 0) { /* * Record the vdev(s) backing this blkptr so they can be * flushed after the writes for the lwb have completed. */ zil_lwb_add_block(zgd->zgd_lwb, zgd->zgd_bp); if (!BP_IS_HOLE(bp)) { blkptr_t *bp_orig __maybe_unused = &zio->io_bp_orig; ASSERT(!(zio->io_flags & ZIO_FLAG_NOPWRITE)); ASSERT(BP_IS_HOLE(bp_orig) || !BP_EQUAL(bp, bp_orig)); ASSERT(zio->io_bp->blk_birth == zio->io_txg); ASSERT(zio->io_txg > spa_syncing_txg(zio->io_spa)); zio_free(zio->io_spa, zio->io_txg, zio->io_bp); } } dmu_tx_commit(dsa->dsa_tx); dsa->dsa_done(dsa->dsa_zgd, zio->io_error); - abd_put(zio->io_abd); + abd_free(zio->io_abd); kmem_free(dsa, sizeof (*dsa)); } static int dmu_sync_late_arrival(zio_t *pio, objset_t *os, dmu_sync_cb_t *done, zgd_t *zgd, zio_prop_t *zp, zbookmark_phys_t *zb) { dmu_sync_arg_t *dsa; dmu_tx_t *tx; tx = dmu_tx_create(os); dmu_tx_hold_space(tx, zgd->zgd_db->db_size); if (dmu_tx_assign(tx, TXG_WAIT) != 0) { dmu_tx_abort(tx); /* Make zl_get_data do txg_waited_synced() */ return (SET_ERROR(EIO)); } /* * In order to prevent the zgd's lwb from being free'd prior to * dmu_sync_late_arrival_done() being called, we have to ensure * the lwb's "max txg" takes this tx's txg into account. */ zil_lwb_add_txg(zgd->zgd_lwb, dmu_tx_get_txg(tx)); dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP); dsa->dsa_dr = NULL; dsa->dsa_done = done; dsa->dsa_zgd = zgd; dsa->dsa_tx = tx; /* * Since we are currently syncing this txg, it's nontrivial to * determine what BP to nopwrite against, so we disable nopwrite. * * When syncing, the db_blkptr is initially the BP of the previous * txg. We can not nopwrite against it because it will be changed * (this is similar to the non-late-arrival case where the dbuf is * dirty in a future txg). * * Then dbuf_write_ready() sets bp_blkptr to the location we will write. * We can not nopwrite against it because although the BP will not * (typically) be changed, the data has not yet been persisted to this * location. * * Finally, when dbuf_write_done() is called, it is theoretically * possible to always nopwrite, because the data that was written in * this txg is the same data that we are trying to write. However we * would need to check that this dbuf is not dirty in any future * txg's (as we do in the normal dmu_sync() path). For simplicity, we * don't nopwrite in this case. */ zp->zp_nopwrite = B_FALSE; zio_nowait(zio_write(pio, os->os_spa, dmu_tx_get_txg(tx), zgd->zgd_bp, abd_get_from_buf(zgd->zgd_db->db_data, zgd->zgd_db->db_size), zgd->zgd_db->db_size, zgd->zgd_db->db_size, zp, dmu_sync_late_arrival_ready, NULL, NULL, dmu_sync_late_arrival_done, dsa, ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, zb)); return (0); } /* * Intent log support: sync the block associated with db to disk. * N.B. and XXX: the caller is responsible for making sure that the * data isn't changing while dmu_sync() is writing it. * * Return values: * * EEXIST: this txg has already been synced, so there's nothing to do. * The caller should not log the write. * * ENOENT: the block was dbuf_free_range()'d, so there's nothing to do. * The caller should not log the write. * * EALREADY: this block is already in the process of being synced. * The caller should track its progress (somehow). * * EIO: could not do the I/O. * The caller should do a txg_wait_synced(). * * 0: the I/O has been initiated. * The caller should log this blkptr in the done callback. * It is possible that the I/O will fail, in which case * the error will be reported to the done callback and * propagated to pio from zio_done(). */ int dmu_sync(zio_t *pio, uint64_t txg, dmu_sync_cb_t *done, zgd_t *zgd) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)zgd->zgd_db; objset_t *os = db->db_objset; dsl_dataset_t *ds = os->os_dsl_dataset; dbuf_dirty_record_t *dr, *dr_next; dmu_sync_arg_t *dsa; zbookmark_phys_t zb; zio_prop_t zp; dnode_t *dn; ASSERT(pio != NULL); ASSERT(txg != 0); SET_BOOKMARK(&zb, ds->ds_object, db->db.db_object, db->db_level, db->db_blkid); DB_DNODE_ENTER(db); dn = DB_DNODE(db); dmu_write_policy(os, dn, db->db_level, WP_DMU_SYNC, &zp); DB_DNODE_EXIT(db); /* * If we're frozen (running ziltest), we always need to generate a bp. */ if (txg > spa_freeze_txg(os->os_spa)) return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb)); /* * Grabbing db_mtx now provides a barrier between dbuf_sync_leaf() * and us. If we determine that this txg is not yet syncing, * but it begins to sync a moment later, that's OK because the * sync thread will block in dbuf_sync_leaf() until we drop db_mtx. */ mutex_enter(&db->db_mtx); if (txg <= spa_last_synced_txg(os->os_spa)) { /* * This txg has already synced. There's nothing to do. */ mutex_exit(&db->db_mtx); return (SET_ERROR(EEXIST)); } if (txg <= spa_syncing_txg(os->os_spa)) { /* * This txg is currently syncing, so we can't mess with * the dirty record anymore; just write a new log block. */ mutex_exit(&db->db_mtx); return (dmu_sync_late_arrival(pio, os, done, zgd, &zp, &zb)); } dr = dbuf_find_dirty_eq(db, txg); if (dr == NULL) { /* * There's no dr for this dbuf, so it must have been freed. * There's no need to log writes to freed blocks, so we're done. */ mutex_exit(&db->db_mtx); return (SET_ERROR(ENOENT)); } dr_next = list_next(&db->db_dirty_records, dr); ASSERT(dr_next == NULL || dr_next->dr_txg < txg); if (db->db_blkptr != NULL) { /* * We need to fill in zgd_bp with the current blkptr so that * the nopwrite code can check if we're writing the same * data that's already on disk. We can only nopwrite if we * are sure that after making the copy, db_blkptr will not * change until our i/o completes. We ensure this by * holding the db_mtx, and only allowing nopwrite if the * block is not already dirty (see below). This is verified * by dmu_sync_done(), which VERIFYs that the db_blkptr has * not changed. */ *zgd->zgd_bp = *db->db_blkptr; } /* * Assume the on-disk data is X, the current syncing data (in * txg - 1) is Y, and the current in-memory data is Z (currently * in dmu_sync). * * We usually want to perform a nopwrite if X and Z are the * same. However, if Y is different (i.e. the BP is going to * change before this write takes effect), then a nopwrite will * be incorrect - we would override with X, which could have * been freed when Y was written. * * (Note that this is not a concern when we are nop-writing from * syncing context, because X and Y must be identical, because * all previous txgs have been synced.) * * Therefore, we disable nopwrite if the current BP could change * before this TXG. There are two ways it could change: by * being dirty (dr_next is non-NULL), or by being freed * (dnode_block_freed()). This behavior is verified by * zio_done(), which VERIFYs that the override BP is identical * to the on-disk BP. */ DB_DNODE_ENTER(db); dn = DB_DNODE(db); if (dr_next != NULL || dnode_block_freed(dn, db->db_blkid)) zp.zp_nopwrite = B_FALSE; DB_DNODE_EXIT(db); ASSERT(dr->dr_txg == txg); if (dr->dt.dl.dr_override_state == DR_IN_DMU_SYNC || dr->dt.dl.dr_override_state == DR_OVERRIDDEN) { /* * We have already issued a sync write for this buffer, * or this buffer has already been synced. It could not * have been dirtied since, or we would have cleared the state. */ mutex_exit(&db->db_mtx); return (SET_ERROR(EALREADY)); } ASSERT(dr->dt.dl.dr_override_state == DR_NOT_OVERRIDDEN); dr->dt.dl.dr_override_state = DR_IN_DMU_SYNC; mutex_exit(&db->db_mtx); dsa = kmem_alloc(sizeof (dmu_sync_arg_t), KM_SLEEP); dsa->dsa_dr = dr; dsa->dsa_done = done; dsa->dsa_zgd = zgd; dsa->dsa_tx = NULL; zio_nowait(arc_write(pio, os->os_spa, txg, zgd->zgd_bp, dr->dt.dl.dr_data, DBUF_IS_L2CACHEABLE(db), &zp, dmu_sync_ready, NULL, NULL, dmu_sync_done, dsa, ZIO_PRIORITY_SYNC_WRITE, ZIO_FLAG_CANFAIL, &zb)); return (0); } int dmu_object_set_nlevels(objset_t *os, uint64_t object, int nlevels, dmu_tx_t *tx) { dnode_t *dn; int err; err = dnode_hold(os, object, FTAG, &dn); if (err) return (err); err = dnode_set_nlevels(dn, nlevels, tx); dnode_rele(dn, FTAG); return (err); } int dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size, int ibs, dmu_tx_t *tx) { dnode_t *dn; int err; err = dnode_hold(os, object, FTAG, &dn); if (err) return (err); err = dnode_set_blksz(dn, size, ibs, tx); dnode_rele(dn, FTAG); return (err); } int dmu_object_set_maxblkid(objset_t *os, uint64_t object, uint64_t maxblkid, dmu_tx_t *tx) { dnode_t *dn; int err; err = dnode_hold(os, object, FTAG, &dn); if (err) return (err); rw_enter(&dn->dn_struct_rwlock, RW_WRITER); dnode_new_blkid(dn, maxblkid, tx, B_FALSE, B_TRUE); rw_exit(&dn->dn_struct_rwlock); dnode_rele(dn, FTAG); return (0); } void dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum, dmu_tx_t *tx) { dnode_t *dn; /* * Send streams include each object's checksum function. This * check ensures that the receiving system can understand the * checksum function transmitted. */ ASSERT3U(checksum, <, ZIO_CHECKSUM_LEGACY_FUNCTIONS); VERIFY0(dnode_hold(os, object, FTAG, &dn)); ASSERT3U(checksum, <, ZIO_CHECKSUM_FUNCTIONS); dn->dn_checksum = checksum; dnode_setdirty(dn, tx); dnode_rele(dn, FTAG); } void dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress, dmu_tx_t *tx) { dnode_t *dn; /* * Send streams include each object's compression function. This * check ensures that the receiving system can understand the * compression function transmitted. */ ASSERT3U(compress, <, ZIO_COMPRESS_LEGACY_FUNCTIONS); VERIFY0(dnode_hold(os, object, FTAG, &dn)); dn->dn_compress = compress; dnode_setdirty(dn, tx); dnode_rele(dn, FTAG); } /* * When the "redundant_metadata" property is set to "most", only indirect * blocks of this level and higher will have an additional ditto block. */ int zfs_redundant_metadata_most_ditto_level = 2; void dmu_write_policy(objset_t *os, dnode_t *dn, int level, int wp, zio_prop_t *zp) { dmu_object_type_t type = dn ? dn->dn_type : DMU_OT_OBJSET; boolean_t ismd = (level > 0 || DMU_OT_IS_METADATA(type) || (wp & WP_SPILL)); enum zio_checksum checksum = os->os_checksum; enum zio_compress compress = os->os_compress; uint8_t complevel = os->os_complevel; enum zio_checksum dedup_checksum = os->os_dedup_checksum; boolean_t dedup = B_FALSE; boolean_t nopwrite = B_FALSE; boolean_t dedup_verify = os->os_dedup_verify; boolean_t encrypt = B_FALSE; int copies = os->os_copies; /* * We maintain different write policies for each of the following * types of data: * 1. metadata * 2. preallocated blocks (i.e. level-0 blocks of a dump device) * 3. all other level 0 blocks */ if (ismd) { /* * XXX -- we should design a compression algorithm * that specializes in arrays of bps. */ compress = zio_compress_select(os->os_spa, ZIO_COMPRESS_ON, ZIO_COMPRESS_ON); /* * Metadata always gets checksummed. If the data * checksum is multi-bit correctable, and it's not a * ZBT-style checksum, then it's suitable for metadata * as well. Otherwise, the metadata checksum defaults * to fletcher4. */ if (!(zio_checksum_table[checksum].ci_flags & ZCHECKSUM_FLAG_METADATA) || (zio_checksum_table[checksum].ci_flags & ZCHECKSUM_FLAG_EMBEDDED)) checksum = ZIO_CHECKSUM_FLETCHER_4; if (os->os_redundant_metadata == ZFS_REDUNDANT_METADATA_ALL || (os->os_redundant_metadata == ZFS_REDUNDANT_METADATA_MOST && (level >= zfs_redundant_metadata_most_ditto_level || DMU_OT_IS_METADATA(type) || (wp & WP_SPILL)))) copies++; } else if (wp & WP_NOFILL) { ASSERT(level == 0); /* * If we're writing preallocated blocks, we aren't actually * writing them so don't set any policy properties. These * blocks are currently only used by an external subsystem * outside of zfs (i.e. dump) and not written by the zio * pipeline. */ compress = ZIO_COMPRESS_OFF; checksum = ZIO_CHECKSUM_OFF; } else { compress = zio_compress_select(os->os_spa, dn->dn_compress, compress); complevel = zio_complevel_select(os->os_spa, compress, complevel, complevel); checksum = (dedup_checksum == ZIO_CHECKSUM_OFF) ? zio_checksum_select(dn->dn_checksum, checksum) : dedup_checksum; /* * Determine dedup setting. If we are in dmu_sync(), * we won't actually dedup now because that's all * done in syncing context; but we do want to use the * dedup checksum. If the checksum is not strong * enough to ensure unique signatures, force * dedup_verify. */ if (dedup_checksum != ZIO_CHECKSUM_OFF) { dedup = (wp & WP_DMU_SYNC) ? B_FALSE : B_TRUE; if (!(zio_checksum_table[checksum].ci_flags & ZCHECKSUM_FLAG_DEDUP)) dedup_verify = B_TRUE; } /* * Enable nopwrite if we have secure enough checksum * algorithm (see comment in zio_nop_write) and * compression is enabled. We don't enable nopwrite if * dedup is enabled as the two features are mutually * exclusive. */ nopwrite = (!dedup && (zio_checksum_table[checksum].ci_flags & ZCHECKSUM_FLAG_NOPWRITE) && compress != ZIO_COMPRESS_OFF && zfs_nopwrite_enabled); } /* * All objects in an encrypted objset are protected from modification * via a MAC. Encrypted objects store their IV and salt in the last DVA * in the bp, so we cannot use all copies. Encrypted objects are also * not subject to nopwrite since writing the same data will still * result in a new ciphertext. Only encrypted blocks can be dedup'd * to avoid ambiguity in the dedup code since the DDT does not store * object types. */ if (os->os_encrypted && (wp & WP_NOFILL) == 0) { encrypt = B_TRUE; if (DMU_OT_IS_ENCRYPTED(type)) { copies = MIN(copies, SPA_DVAS_PER_BP - 1); nopwrite = B_FALSE; } else { dedup = B_FALSE; } if (level <= 0 && (type == DMU_OT_DNODE || type == DMU_OT_OBJSET)) { compress = ZIO_COMPRESS_EMPTY; } } zp->zp_compress = compress; zp->zp_complevel = complevel; zp->zp_checksum = checksum; zp->zp_type = (wp & WP_SPILL) ? dn->dn_bonustype : type; zp->zp_level = level; zp->zp_copies = MIN(copies, spa_max_replication(os->os_spa)); zp->zp_dedup = dedup; zp->zp_dedup_verify = dedup && dedup_verify; zp->zp_nopwrite = nopwrite; zp->zp_encrypt = encrypt; zp->zp_byteorder = ZFS_HOST_BYTEORDER; bzero(zp->zp_salt, ZIO_DATA_SALT_LEN); bzero(zp->zp_iv, ZIO_DATA_IV_LEN); bzero(zp->zp_mac, ZIO_DATA_MAC_LEN); zp->zp_zpl_smallblk = DMU_OT_IS_FILE(zp->zp_type) ? os->os_zpl_special_smallblock : 0; ASSERT3U(zp->zp_compress, !=, ZIO_COMPRESS_INHERIT); } /* * This function is only called from zfs_holey_common() for zpl_llseek() * in order to determine the location of holes. In order to accurately * report holes all dirty data must be synced to disk. This causes extremely * poor performance when seeking for holes in a dirty file. As a compromise, * only provide hole data when the dnode is clean. When a dnode is dirty * report the dnode as having no holes which is always a safe thing to do. */ int dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole, uint64_t *off) { dnode_t *dn; int i, err; boolean_t clean = B_TRUE; err = dnode_hold(os, object, FTAG, &dn); if (err) return (err); /* * Check if dnode is dirty */ for (i = 0; i < TXG_SIZE; i++) { if (multilist_link_active(&dn->dn_dirty_link[i])) { clean = B_FALSE; break; } } /* * If compatibility option is on, sync any current changes before * we go trundling through the block pointers. */ if (!clean && zfs_dmu_offset_next_sync) { clean = B_TRUE; dnode_rele(dn, FTAG); txg_wait_synced(dmu_objset_pool(os), 0); err = dnode_hold(os, object, FTAG, &dn); if (err) return (err); } if (clean) err = dnode_next_offset(dn, (hole ? DNODE_FIND_HOLE : 0), off, 1, 1, 0); else err = SET_ERROR(EBUSY); dnode_rele(dn, FTAG); return (err); } void __dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi) { dnode_phys_t *dnp = dn->dn_phys; doi->doi_data_block_size = dn->dn_datablksz; doi->doi_metadata_block_size = dn->dn_indblkshift ? 1ULL << dn->dn_indblkshift : 0; doi->doi_type = dn->dn_type; doi->doi_bonus_type = dn->dn_bonustype; doi->doi_bonus_size = dn->dn_bonuslen; doi->doi_dnodesize = dn->dn_num_slots << DNODE_SHIFT; doi->doi_indirection = dn->dn_nlevels; doi->doi_checksum = dn->dn_checksum; doi->doi_compress = dn->dn_compress; doi->doi_nblkptr = dn->dn_nblkptr; doi->doi_physical_blocks_512 = (DN_USED_BYTES(dnp) + 256) >> 9; doi->doi_max_offset = (dn->dn_maxblkid + 1) * dn->dn_datablksz; doi->doi_fill_count = 0; for (int i = 0; i < dnp->dn_nblkptr; i++) doi->doi_fill_count += BP_GET_FILL(&dnp->dn_blkptr[i]); } void dmu_object_info_from_dnode(dnode_t *dn, dmu_object_info_t *doi) { rw_enter(&dn->dn_struct_rwlock, RW_READER); mutex_enter(&dn->dn_mtx); __dmu_object_info_from_dnode(dn, doi); mutex_exit(&dn->dn_mtx); rw_exit(&dn->dn_struct_rwlock); } /* * Get information on a DMU object. * If doi is NULL, just indicates whether the object exists. */ int dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi) { dnode_t *dn; int err = dnode_hold(os, object, FTAG, &dn); if (err) return (err); if (doi != NULL) dmu_object_info_from_dnode(dn, doi); dnode_rele(dn, FTAG); return (0); } /* * As above, but faster; can be used when you have a held dbuf in hand. */ void dmu_object_info_from_db(dmu_buf_t *db_fake, dmu_object_info_t *doi) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; DB_DNODE_ENTER(db); dmu_object_info_from_dnode(DB_DNODE(db), doi); DB_DNODE_EXIT(db); } /* * Faster still when you only care about the size. */ void dmu_object_size_from_db(dmu_buf_t *db_fake, uint32_t *blksize, u_longlong_t *nblk512) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; dnode_t *dn; DB_DNODE_ENTER(db); dn = DB_DNODE(db); *blksize = dn->dn_datablksz; /* add in number of slots used for the dnode itself */ *nblk512 = ((DN_USED_BYTES(dn->dn_phys) + SPA_MINBLOCKSIZE/2) >> SPA_MINBLOCKSHIFT) + dn->dn_num_slots; DB_DNODE_EXIT(db); } void dmu_object_dnsize_from_db(dmu_buf_t *db_fake, int *dnsize) { dmu_buf_impl_t *db = (dmu_buf_impl_t *)db_fake; dnode_t *dn; DB_DNODE_ENTER(db); dn = DB_DNODE(db); *dnsize = dn->dn_num_slots << DNODE_SHIFT; DB_DNODE_EXIT(db); } void byteswap_uint64_array(void *vbuf, size_t size) { uint64_t *buf = vbuf; size_t count = size >> 3; int i; ASSERT((size & 7) == 0); for (i = 0; i < count; i++) buf[i] = BSWAP_64(buf[i]); } void byteswap_uint32_array(void *vbuf, size_t size) { uint32_t *buf = vbuf; size_t count = size >> 2; int i; ASSERT((size & 3) == 0); for (i = 0; i < count; i++) buf[i] = BSWAP_32(buf[i]); } void byteswap_uint16_array(void *vbuf, size_t size) { uint16_t *buf = vbuf; size_t count = size >> 1; int i; ASSERT((size & 1) == 0); for (i = 0; i < count; i++) buf[i] = BSWAP_16(buf[i]); } /* ARGSUSED */ void byteswap_uint8_array(void *vbuf, size_t size) { } void dmu_init(void) { abd_init(); zfs_dbgmsg_init(); sa_cache_init(); dmu_objset_init(); dnode_init(); zfetch_init(); dmu_tx_init(); l2arc_init(); arc_init(); dbuf_init(); } void dmu_fini(void) { arc_fini(); /* arc depends on l2arc, so arc must go first */ l2arc_fini(); dmu_tx_fini(); zfetch_fini(); dbuf_fini(); dnode_fini(); dmu_objset_fini(); sa_cache_fini(); zfs_dbgmsg_fini(); abd_fini(); } EXPORT_SYMBOL(dmu_bonus_hold); EXPORT_SYMBOL(dmu_bonus_hold_by_dnode); EXPORT_SYMBOL(dmu_buf_hold_array_by_bonus); EXPORT_SYMBOL(dmu_buf_rele_array); EXPORT_SYMBOL(dmu_prefetch); EXPORT_SYMBOL(dmu_free_range); EXPORT_SYMBOL(dmu_free_long_range); EXPORT_SYMBOL(dmu_free_long_object); EXPORT_SYMBOL(dmu_read); EXPORT_SYMBOL(dmu_read_by_dnode); EXPORT_SYMBOL(dmu_write); EXPORT_SYMBOL(dmu_write_by_dnode); EXPORT_SYMBOL(dmu_prealloc); EXPORT_SYMBOL(dmu_object_info); EXPORT_SYMBOL(dmu_object_info_from_dnode); EXPORT_SYMBOL(dmu_object_info_from_db); EXPORT_SYMBOL(dmu_object_size_from_db); EXPORT_SYMBOL(dmu_object_dnsize_from_db); EXPORT_SYMBOL(dmu_object_set_nlevels); EXPORT_SYMBOL(dmu_object_set_blocksize); EXPORT_SYMBOL(dmu_object_set_maxblkid); EXPORT_SYMBOL(dmu_object_set_checksum); EXPORT_SYMBOL(dmu_object_set_compress); EXPORT_SYMBOL(dmu_offset_next); EXPORT_SYMBOL(dmu_write_policy); EXPORT_SYMBOL(dmu_sync); EXPORT_SYMBOL(dmu_request_arcbuf); EXPORT_SYMBOL(dmu_return_arcbuf); EXPORT_SYMBOL(dmu_assign_arcbuf_by_dnode); EXPORT_SYMBOL(dmu_assign_arcbuf_by_dbuf); EXPORT_SYMBOL(dmu_buf_hold); EXPORT_SYMBOL(dmu_ot); /* BEGIN CSTYLED */ ZFS_MODULE_PARAM(zfs, zfs_, nopwrite_enabled, INT, ZMOD_RW, "Enable NOP writes"); ZFS_MODULE_PARAM(zfs, zfs_, per_txg_dirty_frees_percent, ULONG, ZMOD_RW, "Percentage of dirtied blocks from frees in one TXG"); ZFS_MODULE_PARAM(zfs, zfs_, dmu_offset_next_sync, INT, ZMOD_RW, "Enable forcing txg sync to find holes"); ZFS_MODULE_PARAM(zfs, , dmu_prefetch_max, INT, ZMOD_RW, "Limit one prefetch call to this size"); /* END CSTYLED */ diff --git a/module/zfs/vdev_draid.c b/module/zfs/vdev_draid.c index 6b7ad7021a50..a4f48cf744b0 100644 --- a/module/zfs/vdev_draid.c +++ b/module/zfs/vdev_draid.c @@ -1,2984 +1,2976 @@ /* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (c) 2018 Intel Corporation. * Copyright (c) 2020 by Lawrence Livermore National Security, LLC. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef ZFS_DEBUG #include /* For vdev_xlate() in vdev_draid_io_verify() */ #endif /* * dRAID is a distributed spare implementation for ZFS. A dRAID vdev is * comprised of multiple raidz redundancy groups which are spread over the * dRAID children. To ensure an even distribution, and avoid hot spots, a * permutation mapping is applied to the order of the dRAID children. * This mixing effectively distributes the parity columns evenly over all * of the disks in the dRAID. * * This is beneficial because it means when resilvering all of the disks * can participate thereby increasing the available IOPs and bandwidth. * Furthermore, by reserving a small fraction of each child's total capacity * virtual distributed spare disks can be created. These spares similarly * benefit from the performance gains of spanning all of the children. The * consequence of which is that resilvering to a distributed spare can * substantially reduce the time required to restore full parity to pool * with a failed disks. * * === dRAID group layout === * * First, let's define a "row" in the configuration to be a 16M chunk from * each physical drive at the same offset. This is the minimum allowable * size since it must be possible to store a full 16M block when there is * only a single data column. Next, we define a "group" to be a set of * sequential disks containing both the parity and data columns. We allow * groups to span multiple rows in order to align any group size to any * number of physical drives. Finally, a "slice" is comprised of the rows * which contain the target number of groups. The permutation mappings * are applied in a round robin fashion to each slice. * * Given D+P drives in a group (including parity drives) and C-S physical * drives (not including the spare drives), we can distribute the groups * across R rows without remainder by selecting the least common multiple * of D+P and C-S as the number of groups; i.e. ngroups = LCM(D+P, C-S). * * In the example below, there are C=14 physical drives in the configuration * with S=2 drives worth of spare capacity. Each group has a width of 9 * which includes D=8 data and P=1 parity drive. There are 4 groups and * 3 rows per slice. Each group has a size of 144M (16M * 9) and a slice * size is 576M (144M * 4). When allocating from a dRAID each group is * filled before moving on to the next as show in slice0 below. * * data disks (8 data + 1 parity) spares (2) * +===+===+===+===+===+===+===+===+===+===+===+===+===+===+ * ^ | 2 | 6 | 1 | 11| 4 | 0 | 7 | 10| 8 | 9 | 13| 5 | 12| 3 | device map 0 * | +===+===+===+===+===+===+===+===+===+===+===+===+===+===+ * | | group 0 | group 1..| | * | +-----------------------------------+-----------+-------| * | | 0 1 2 3 4 5 6 7 8 | 36 37 38| | r * | | 9 10 11 12 13 14 15 16 17| 45 46 47| | o * | | 18 19 20 21 22 23 24 25 26| 54 55 56| | w * | 27 28 29 30 31 32 33 34 35| 63 64 65| | 0 * s +-----------------------+-----------------------+-------+ * l | ..group 1 | group 2.. | | * i +-----------------------+-----------------------+-------+ * c | 39 40 41 42 43 44| 72 73 74 75 76 77| | r * e | 48 49 50 51 52 53| 81 82 83 84 85 86| | o * 0 | 57 58 59 60 61 62| 90 91 92 93 94 95| | w * | 66 67 68 69 70 71| 99 100 101 102 103 104| | 1 * | +-----------+-----------+-----------------------+-------+ * | |..group 2 | group 3 | | * | +-----------+-----------+-----------------------+-------+ * | | 78 79 80|108 109 110 111 112 113 114 115 116| | r * | | 87 88 89|117 118 119 120 121 122 123 124 125| | o * | | 96 97 98|126 127 128 129 130 131 132 133 134| | w * v |105 106 107|135 136 137 138 139 140 141 142 143| | 2 * +===+===+===+===+===+===+===+===+===+===+===+===+===+===+ * | 9 | 11| 12| 2 | 4 | 1 | 3 | 0 | 10| 13| 8 | 5 | 6 | 7 | device map 1 * s +===+===+===+===+===+===+===+===+===+===+===+===+===+===+ * l | group 4 | group 5..| | row 3 * i +-----------------------+-----------+-----------+-------| * c | ..group 5 | group 6.. | | row 4 * e +-----------+-----------+-----------------------+-------+ * 1 |..group 6 | group 7 | | row 5 * +===+===+===+===+===+===+===+===+===+===+===+===+===+===+ * | 3 | 5 | 10| 8 | 6 | 11| 12| 0 | 2 | 4 | 7 | 1 | 9 | 13| device map 2 * s +===+===+===+===+===+===+===+===+===+===+===+===+===+===+ * l | group 8 | group 9..| | row 6 * i +-----------------------------------------------+-------| * c | ..group 9 | group 10.. | | row 7 * e +-----------------------+-----------------------+-------+ * 2 |..group 10 | group 11 | | row 8 * +-----------+-----------------------------------+-------+ * * This layout has several advantages over requiring that each row contain * a whole number of groups. * * 1. The group count is not a relevant parameter when defining a dRAID * layout. Only the group width is needed, and *all* groups will have * the desired size. * * 2. All possible group widths (<= physical disk count) can be supported. * * 3. The logic within vdev_draid.c is simplified when the group width is * the same for all groups (although some of the logic around computing * permutation numbers and drive offsets is more complicated). * * N.B. The following array describes all valid dRAID permutation maps. * Each row is used to generate a permutation map for a different number * of children from a unique seed. The seeds were generated and carefully * evaluated by the 'draid' utility in order to provide balanced mappings. * In addition to the seed a checksum of the in-memory mapping is stored * for verification. * * The imbalance ratio of a given failure (e.g. 5 disks wide, child 3 failed, * with a given permutation map) is the ratio of the amounts of I/O that will * be sent to the least and most busy disks when resilvering. The average * imbalance ratio (of a given number of disks and permutation map) is the * average of the ratios of all possible single and double disk failures. * * In order to achieve a low imbalance ratio the number of permutations in * the mapping must be significantly larger than the number of children. * For dRAID the number of permutations has been limited to 512 to minimize * the map size. This does result in a gradually increasing imbalance ratio * as seen in the table below. Increasing the number of permutations for * larger child counts would reduce the imbalance ratio. However, in practice * when there are a large number of children each child is responsible for * fewer total IOs so it's less of a concern. * * Note these values are hard coded and must never be changed. Existing * pools depend on the same mapping always being generated in order to * read and write from the correct locations. Any change would make * existing pools completely inaccessible. */ static const draid_map_t draid_maps[VDEV_DRAID_MAX_MAPS] = { { 2, 256, 0x89ef3dabbcc7de37, 0x00000000433d433d }, /* 1.000 */ { 3, 256, 0x89a57f3de98121b4, 0x00000000bcd8b7b5 }, /* 1.000 */ { 4, 256, 0xc9ea9ec82340c885, 0x00000001819d7c69 }, /* 1.000 */ { 5, 256, 0xf46733b7f4d47dfd, 0x00000002a1648d74 }, /* 1.010 */ { 6, 256, 0x88c3c62d8585b362, 0x00000003d3b0c2c4 }, /* 1.031 */ { 7, 256, 0x3a65d809b4d1b9d5, 0x000000055c4183ee }, /* 1.043 */ { 8, 256, 0xe98930e3c5d2e90a, 0x00000006edfb0329 }, /* 1.059 */ { 9, 256, 0x5a5430036b982ccb, 0x00000008ceaf6934 }, /* 1.056 */ { 10, 256, 0x92bf389e9eadac74, 0x0000000b26668c09 }, /* 1.072 */ { 11, 256, 0x74ccebf1dcf3ae80, 0x0000000dd691358c }, /* 1.083 */ { 12, 256, 0x8847e41a1a9f5671, 0x00000010a0c63c8e }, /* 1.097 */ { 13, 256, 0x7481b56debf0e637, 0x0000001424121fe4 }, /* 1.100 */ { 14, 256, 0x559b8c44065f8967, 0x00000016ab2ff079 }, /* 1.121 */ { 15, 256, 0x34c49545a2ee7f01, 0x0000001a6028efd6 }, /* 1.103 */ { 16, 256, 0xb85f4fa81a7698f7, 0x0000001e95ff5e66 }, /* 1.111 */ { 17, 256, 0x6353e47b7e47aba0, 0x00000021a81fa0fe }, /* 1.133 */ { 18, 256, 0xaa549746b1cbb81c, 0x00000026f02494c9 }, /* 1.131 */ { 19, 256, 0x892e343f2f31d690, 0x00000029eb392835 }, /* 1.130 */ { 20, 256, 0x76914824db98cc3f, 0x0000003004f31a7c }, /* 1.141 */ { 21, 256, 0x4b3cbabf9cfb1d0f, 0x00000036363a2408 }, /* 1.139 */ { 22, 256, 0xf45c77abb4f035d4, 0x00000038dd0f3e84 }, /* 1.150 */ { 23, 256, 0x5e18bd7f3fd4baf4, 0x0000003f0660391f }, /* 1.174 */ { 24, 256, 0xa7b3a4d285d6503b, 0x000000443dfc9ff6 }, /* 1.168 */ { 25, 256, 0x56ac7dd967521f5a, 0x0000004b03a87eb7 }, /* 1.180 */ { 26, 256, 0x3a42dfda4eb880f7, 0x000000522c719bba }, /* 1.226 */ { 27, 256, 0xd200d2fc6b54bf60, 0x0000005760b4fdf5 }, /* 1.228 */ { 28, 256, 0xc52605bbd486c546, 0x0000005e00d8f74c }, /* 1.217 */ { 29, 256, 0xc761779e63cd762f, 0x00000067be3cd85c }, /* 1.239 */ { 30, 256, 0xca577b1e07f85ca5, 0x0000006f5517f3e4 }, /* 1.238 */ { 31, 256, 0xfd50a593c518b3d4, 0x0000007370e7778f }, /* 1.273 */ { 32, 512, 0xc6c87ba5b042650b, 0x000000f7eb08a156 }, /* 1.191 */ { 33, 512, 0xc3880d0c9d458304, 0x0000010734b5d160 }, /* 1.199 */ { 34, 512, 0xe920927e4d8b2c97, 0x00000118c1edbce0 }, /* 1.195 */ { 35, 512, 0x8da7fcda87bde316, 0x0000012a3e9f9110 }, /* 1.201 */ { 36, 512, 0xcf09937491514a29, 0x0000013bd6a24bef }, /* 1.194 */ { 37, 512, 0x9b5abbf345cbd7cc, 0x0000014b9d90fac3 }, /* 1.237 */ { 38, 512, 0x506312a44668d6a9, 0x0000015e1b5f6148 }, /* 1.242 */ { 39, 512, 0x71659ede62b4755f, 0x00000173ef029bcd }, /* 1.231 */ { 40, 512, 0xa7fde73fb74cf2d7, 0x000001866fb72748 }, /* 1.233 */ { 41, 512, 0x19e8b461a1dea1d3, 0x000001a046f76b23 }, /* 1.271 */ { 42, 512, 0x031c9b868cc3e976, 0x000001afa64c49d3 }, /* 1.263 */ { 43, 512, 0xbaa5125faa781854, 0x000001c76789e278 }, /* 1.270 */ { 44, 512, 0x4ed55052550d721b, 0x000001d800ccd8eb }, /* 1.281 */ { 45, 512, 0x0fd63ddbdff90677, 0x000001f08ad59ed2 }, /* 1.282 */ { 46, 512, 0x36d66546de7fdd6f, 0x000002016f09574b }, /* 1.286 */ { 47, 512, 0x99f997e7eafb69d7, 0x0000021e42e47cb6 }, /* 1.329 */ { 48, 512, 0xbecd9c2571312c5d, 0x000002320fe2872b }, /* 1.286 */ { 49, 512, 0xd97371329e488a32, 0x0000024cd73f2ca7 }, /* 1.322 */ { 50, 512, 0x30e9b136670749ee, 0x000002681c83b0e0 }, /* 1.335 */ { 51, 512, 0x11ad6bc8f47aaeb4, 0x0000027e9261b5d5 }, /* 1.305 */ { 52, 512, 0x68e445300af432c1, 0x0000029aa0eb7dbf }, /* 1.330 */ { 53, 512, 0x910fb561657ea98c, 0x000002b3dca04853 }, /* 1.365 */ { 54, 512, 0xd619693d8ce5e7a5, 0x000002cc280e9c97 }, /* 1.334 */ { 55, 512, 0x24e281f564dbb60a, 0x000002e9fa842713 }, /* 1.364 */ { 56, 512, 0x947a7d3bdaab44c5, 0x000003046680f72e }, /* 1.374 */ { 57, 512, 0x2d44fec9c093e0de, 0x00000324198ba810 }, /* 1.363 */ { 58, 512, 0x87743c272d29bb4c, 0x0000033ec48c9ac9 }, /* 1.401 */ { 59, 512, 0x96aa3b6f67f5d923, 0x0000034faead902c }, /* 1.392 */ { 60, 512, 0x94a4f1faf520b0d3, 0x0000037d713ab005 }, /* 1.360 */ { 61, 512, 0xb13ed3a272f711a2, 0x00000397368f3cbd }, /* 1.396 */ { 62, 512, 0x3b1b11805fa4a64a, 0x000003b8a5e2840c }, /* 1.453 */ { 63, 512, 0x4c74caad9172ba71, 0x000003d4be280290 }, /* 1.437 */ { 64, 512, 0x035ff643923dd29e, 0x000003fad6c355e1 }, /* 1.402 */ { 65, 512, 0x768e9171b11abd3c, 0x0000040eb07fed20 }, /* 1.459 */ { 66, 512, 0x75880e6f78a13ddd, 0x000004433d6acf14 }, /* 1.423 */ { 67, 512, 0x910b9714f698a877, 0x00000451ea65d5db }, /* 1.447 */ { 68, 512, 0x87f5db6f9fdcf5c7, 0x000004732169e3f7 }, /* 1.450 */ { 69, 512, 0x836d4968fbaa3706, 0x000004954068a380 }, /* 1.455 */ { 70, 512, 0xc567d73a036421ab, 0x000004bd7cb7bd3d }, /* 1.463 */ { 71, 512, 0x619df40f240b8fed, 0x000004e376c2e972 }, /* 1.463 */ { 72, 512, 0x42763a680d5bed8e, 0x000005084275c680 }, /* 1.452 */ { 73, 512, 0x5866f064b3230431, 0x0000052906f2c9ab }, /* 1.498 */ { 74, 512, 0x9fa08548b1621a44, 0x0000054708019247 }, /* 1.526 */ { 75, 512, 0xb6053078ce0fc303, 0x00000572cc5c72b0 }, /* 1.491 */ { 76, 512, 0x4a7aad7bf3890923, 0x0000058e987bc8e9 }, /* 1.470 */ { 77, 512, 0xe165613fd75b5a53, 0x000005c20473a211 }, /* 1.527 */ { 78, 512, 0x3ff154ac878163a6, 0x000005d659194bf3 }, /* 1.509 */ { 79, 512, 0x24b93ade0aa8a532, 0x0000060a201c4f8e }, /* 1.569 */ { 80, 512, 0xc18e2d14cd9bb554, 0x0000062c55cfe48c }, /* 1.555 */ { 81, 512, 0x98cc78302feb58b6, 0x0000066656a07194 }, /* 1.509 */ { 82, 512, 0xc6c5fd5a2abc0543, 0x0000067cff94fbf8 }, /* 1.596 */ { 83, 512, 0xa7962f514acbba21, 0x000006ab7b5afa2e }, /* 1.568 */ { 84, 512, 0xba02545069ddc6dc, 0x000006d19861364f }, /* 1.541 */ { 85, 512, 0x447c73192c35073e, 0x000006fce315ce35 }, /* 1.623 */ { 86, 512, 0x48beef9e2d42b0c2, 0x00000720a8e38b6b }, /* 1.620 */ { 87, 512, 0x4874cf98541a35e0, 0x00000758382a2273 }, /* 1.597 */ { 88, 512, 0xad4cf8333a31127a, 0x00000781e1651b1b }, /* 1.575 */ { 89, 512, 0x47ae4859d57888c1, 0x000007b27edbe5bc }, /* 1.627 */ { 90, 512, 0x06f7723cfe5d1891, 0x000007dc2a96d8eb }, /* 1.596 */ { 91, 512, 0xd4e44218d660576d, 0x0000080ac46f02d5 }, /* 1.622 */ { 92, 512, 0x7066702b0d5be1f2, 0x00000832c96d154e }, /* 1.695 */ { 93, 512, 0x011209b4f9e11fb9, 0x0000085eefda104c }, /* 1.605 */ { 94, 512, 0x47ffba30a0b35708, 0x00000899badc32dc }, /* 1.625 */ { 95, 512, 0x1a95a6ac4538aaa8, 0x000008b6b69a42b2 }, /* 1.687 */ { 96, 512, 0xbda2b239bb2008eb, 0x000008f22d2de38a }, /* 1.621 */ { 97, 512, 0x7ffa0bea90355c6c, 0x0000092e5b23b816 }, /* 1.699 */ { 98, 512, 0x1d56ba34be426795, 0x0000094f482e5d1b }, /* 1.688 */ { 99, 512, 0x0aa89d45c502e93d, 0x00000977d94a98ce }, /* 1.642 */ { 100, 512, 0x54369449f6857774, 0x000009c06c9b34cc }, /* 1.683 */ { 101, 512, 0xf7d4dd8445b46765, 0x000009e5dc542259 }, /* 1.755 */ { 102, 512, 0xfa8866312f169469, 0x00000a16b54eae93 }, /* 1.692 */ { 103, 512, 0xd8a5aea08aef3ff9, 0x00000a381d2cbfe7 }, /* 1.747 */ { 104, 512, 0x66bcd2c3d5f9ef0e, 0x00000a8191817be7 }, /* 1.751 */ { 105, 512, 0x3fb13a47a012ec81, 0x00000ab562b9a254 }, /* 1.751 */ { 106, 512, 0x43100f01c9e5e3ca, 0x00000aeee84c185f }, /* 1.726 */ { 107, 512, 0xca09c50ccee2d054, 0x00000b1c359c047d }, /* 1.788 */ { 108, 512, 0xd7176732ac503f9b, 0x00000b578bc52a73 }, /* 1.740 */ { 109, 512, 0xed206e51f8d9422d, 0x00000b8083e0d960 }, /* 1.780 */ { 110, 512, 0x17ead5dc6ba0dcd6, 0x00000bcfb1a32ca8 }, /* 1.836 */ { 111, 512, 0x5f1dc21e38a969eb, 0x00000c0171becdd6 }, /* 1.778 */ { 112, 512, 0xddaa973de33ec528, 0x00000c3edaba4b95 }, /* 1.831 */ { 113, 512, 0x2a5eccd7735a3630, 0x00000c630664e7df }, /* 1.825 */ { 114, 512, 0xafcccee5c0b71446, 0x00000cb65392f6e4 }, /* 1.826 */ { 115, 512, 0x8fa30c5e7b147e27, 0x00000cd4db391e55 }, /* 1.843 */ { 116, 512, 0x5afe0711fdfafd82, 0x00000d08cb4ec35d }, /* 1.826 */ { 117, 512, 0x533a6090238afd4c, 0x00000d336f115d1b }, /* 1.803 */ { 118, 512, 0x90cf11b595e39a84, 0x00000d8e041c2048 }, /* 1.857 */ { 119, 512, 0x0d61a3b809444009, 0x00000dcb798afe35 }, /* 1.877 */ { 120, 512, 0x7f34da0f54b0d114, 0x00000df3922664e1 }, /* 1.849 */ { 121, 512, 0xa52258d5b72f6551, 0x00000e4d37a9872d }, /* 1.867 */ { 122, 512, 0xc1de54d7672878db, 0x00000e6583a94cf6 }, /* 1.978 */ { 123, 512, 0x1d03354316a414ab, 0x00000ebffc50308d }, /* 1.947 */ { 124, 512, 0xcebdcc377665412c, 0x00000edee1997cea }, /* 1.865 */ { 125, 512, 0x4ddd4c04b1a12344, 0x00000f21d64b373f }, /* 1.881 */ { 126, 512, 0x64fc8f94e3973658, 0x00000f8f87a8896b }, /* 1.882 */ { 127, 512, 0x68765f78034a334e, 0x00000fb8fe62197e }, /* 1.867 */ { 128, 512, 0xaf36b871a303e816, 0x00000fec6f3afb1e }, /* 1.972 */ { 129, 512, 0x2a4cbf73866c3a28, 0x00001027febfe4e5 }, /* 1.896 */ { 130, 512, 0x9cb128aacdcd3b2f, 0x0000106aa8ac569d }, /* 1.965 */ { 131, 512, 0x5511d41c55869124, 0x000010bbd755ddf1 }, /* 1.963 */ { 132, 512, 0x42f92461937f284a, 0x000010fb8bceb3b5 }, /* 1.925 */ { 133, 512, 0xe2d89a1cf6f1f287, 0x0000114cf5331e34 }, /* 1.862 */ { 134, 512, 0xdc631a038956200e, 0x0000116428d2adc5 }, /* 2.042 */ { 135, 512, 0xb2e5ac222cd236be, 0x000011ca88e4d4d2 }, /* 1.935 */ { 136, 512, 0xbc7d8236655d88e7, 0x000011e39cb94e66 }, /* 2.005 */ { 137, 512, 0x073e02d88d2d8e75, 0x0000123136c7933c }, /* 2.041 */ { 138, 512, 0x3ddb9c3873166be0, 0x00001280e4ec6d52 }, /* 1.997 */ { 139, 512, 0x7d3b1a845420e1b5, 0x000012c2e7cd6a44 }, /* 1.996 */ { 140, 512, 0x60102308aa7b2a6c, 0x000012fc490e6c7d }, /* 2.053 */ { 141, 512, 0xdb22bb2f9eb894aa, 0x00001343f5a85a1a }, /* 1.971 */ { 142, 512, 0xd853f879a13b1606, 0x000013bb7d5f9048 }, /* 2.018 */ { 143, 512, 0x001620a03f804b1d, 0x000013e74cc794fd }, /* 1.961 */ { 144, 512, 0xfdb52dda76fbf667, 0x00001442d2f22480 }, /* 2.046 */ { 145, 512, 0xa9160110f66e24ff, 0x0000144b899f9dbb }, /* 1.968 */ { 146, 512, 0x77306a30379ae03b, 0x000014cb98eb1f81 }, /* 2.143 */ { 147, 512, 0x14f5985d2752319d, 0x000014feab821fc9 }, /* 2.064 */ { 148, 512, 0xa4b8ff11de7863f8, 0x0000154a0e60b9c9 }, /* 2.023 */ { 149, 512, 0x44b345426455c1b3, 0x000015999c3c569c }, /* 2.136 */ { 150, 512, 0x272677826049b46c, 0x000015c9697f4b92 }, /* 2.063 */ { 151, 512, 0x2f9216e2cd74fe40, 0x0000162b1f7bbd39 }, /* 1.974 */ { 152, 512, 0x706ae3e763ad8771, 0x00001661371c55e1 }, /* 2.210 */ { 153, 512, 0xf7fd345307c2480e, 0x000016e251f28b6a }, /* 2.006 */ { 154, 512, 0x6e94e3d26b3139eb, 0x000016f2429bb8c6 }, /* 2.193 */ { 155, 512, 0x5458bbfbb781fcba, 0x0000173efdeca1b9 }, /* 2.163 */ { 156, 512, 0xa80e2afeccd93b33, 0x000017bfdcb78adc }, /* 2.046 */ { 157, 512, 0x1e4ccbb22796cf9d, 0x00001826fdcc39c9 }, /* 2.084 */ { 158, 512, 0x8fba4b676aaa3663, 0x00001841a1379480 }, /* 2.264 */ { 159, 512, 0xf82b843814b315fa, 0x000018886e19b8a3 }, /* 2.074 */ { 160, 512, 0x7f21e920ecf753a3, 0x0000191812ca0ea7 }, /* 2.282 */ { 161, 512, 0x48bb8ea2c4caa620, 0x0000192f310faccf }, /* 2.148 */ { 162, 512, 0x5cdb652b4952c91b, 0x0000199e1d7437c7 }, /* 2.355 */ { 163, 512, 0x6ac1ba6f78c06cd4, 0x000019cd11f82c70 }, /* 2.164 */ { 164, 512, 0x9faf5f9ca2669a56, 0x00001a18d5431f6a }, /* 2.393 */ { 165, 512, 0xaa57e9383eb01194, 0x00001a9e7d253d85 }, /* 2.178 */ { 166, 512, 0x896967bf495c34d2, 0x00001afb8319b9fc }, /* 2.334 */ { 167, 512, 0xdfad5f05de225f1b, 0x00001b3a59c3093b }, /* 2.266 */ { 168, 512, 0xfd299a99f9f2abdd, 0x00001bb6f1a10799 }, /* 2.304 */ { 169, 512, 0xdda239e798fe9fd4, 0x00001bfae0c9692d }, /* 2.218 */ { 170, 512, 0x5fca670414a32c3e, 0x00001c22129dbcff }, /* 2.377 */ { 171, 512, 0x1bb8934314b087de, 0x00001c955db36cd0 }, /* 2.155 */ { 172, 512, 0xd96394b4b082200d, 0x00001cfc8619b7e6 }, /* 2.404 */ { 173, 512, 0xb612a7735b1c8cbc, 0x00001d303acdd585 }, /* 2.205 */ { 174, 512, 0x28e7430fe5875fe1, 0x00001d7ed5b3697d }, /* 2.359 */ { 175, 512, 0x5038e89efdd981b9, 0x00001dc40ec35c59 }, /* 2.158 */ { 176, 512, 0x075fd78f1d14db7c, 0x00001e31c83b4a2b }, /* 2.614 */ { 177, 512, 0xc50fafdb5021be15, 0x00001e7cdac82fbc }, /* 2.239 */ { 178, 512, 0xe6dc7572ce7b91c7, 0x00001edd8bb454fc }, /* 2.493 */ { 179, 512, 0x21f7843e7beda537, 0x00001f3a8e019d6c }, /* 2.327 */ { 180, 512, 0xc83385e20b43ec82, 0x00001f70735ec137 }, /* 2.231 */ { 181, 512, 0xca818217dddb21fd, 0x0000201ca44c5a3c }, /* 2.237 */ { 182, 512, 0xe6035defea48f933, 0x00002038e3346658 }, /* 2.691 */ { 183, 512, 0x47262a4f953dac5a, 0x000020c2e554314e }, /* 2.170 */ { 184, 512, 0xe24c7246260873ea, 0x000021197e618d64 }, /* 2.600 */ { 185, 512, 0xeef6b57c9b58e9e1, 0x0000217ea48ecddc }, /* 2.391 */ { 186, 512, 0x2becd3346e386142, 0x000021c496d4a5f9 }, /* 2.677 */ { 187, 512, 0x63c6207bdf3b40a3, 0x0000220e0f2eec0c }, /* 2.410 */ { 188, 512, 0x3056ce8989767d4b, 0x0000228eb76cd137 }, /* 2.776 */ { 189, 512, 0x91af61c307cee780, 0x000022e17e2ea501 }, /* 2.266 */ { 190, 512, 0xda359da225f6d54f, 0x00002358a2debc19 }, /* 2.717 */ { 191, 512, 0x0a5f7a2a55607ba0, 0x0000238a79dac18c }, /* 2.474 */ { 192, 512, 0x27bb75bf5224638a, 0x00002403a58e2351 }, /* 2.673 */ { 193, 512, 0x1ebfdb94630f5d0f, 0x00002492a10cb339 }, /* 2.420 */ { 194, 512, 0x6eae5e51d9c5f6fb, 0x000024ce4bf98715 }, /* 2.898 */ { 195, 512, 0x08d903b4daedc2e0, 0x0000250d1e15886c }, /* 2.363 */ { 196, 512, 0xc722a2f7fa7cd686, 0x0000258a99ed0c9e }, /* 2.747 */ { 197, 512, 0x8f71faf0e54e361d, 0x000025dee11976f5 }, /* 2.531 */ { 198, 512, 0x87f64695c91a54e7, 0x0000264e00a43da0 }, /* 2.707 */ { 199, 512, 0xc719cbac2c336b92, 0x000026d327277ac1 }, /* 2.315 */ { 200, 512, 0xe7e647afaf771ade, 0x000027523a5c44bf }, /* 3.012 */ { 201, 512, 0x12d4b5c38ce8c946, 0x0000273898432545 }, /* 2.378 */ { 202, 512, 0xf2e0cd4067bdc94a, 0x000027e47bb2c935 }, /* 2.969 */ { 203, 512, 0x21b79f14d6d947d3, 0x0000281e64977f0d }, /* 2.594 */ { 204, 512, 0x515093f952f18cd6, 0x0000289691a473fd }, /* 2.763 */ { 205, 512, 0xd47b160a1b1022c8, 0x00002903e8b52411 }, /* 2.457 */ { 206, 512, 0xc02fc96684715a16, 0x0000297515608601 }, /* 3.057 */ { 207, 512, 0xef51e68efba72ed0, 0x000029ef73604804 }, /* 2.590 */ { 208, 512, 0x9e3be6e5448b4f33, 0x00002a2846ed074b }, /* 3.047 */ { 209, 512, 0x81d446c6d5fec063, 0x00002a92ca693455 }, /* 2.676 */ { 210, 512, 0xff215de8224e57d5, 0x00002b2271fe3729 }, /* 2.993 */ { 211, 512, 0xe2524d9ba8f69796, 0x00002b64b99c3ba2 }, /* 2.457 */ { 212, 512, 0xf6b28e26097b7e4b, 0x00002bd768b6e068 }, /* 3.182 */ { 213, 512, 0x893a487f30ce1644, 0x00002c67f722b4b2 }, /* 2.563 */ { 214, 512, 0x386566c3fc9871df, 0x00002cc1cf8b4037 }, /* 3.025 */ { 215, 512, 0x1e0ed78edf1f558a, 0x00002d3948d36c7f }, /* 2.730 */ { 216, 512, 0xe3bc20c31e61f113, 0x00002d6d6b12e025 }, /* 3.036 */ { 217, 512, 0xd6c3ad2e23021882, 0x00002deff7572241 }, /* 2.722 */ { 218, 512, 0xb4a9f95cf0f69c5a, 0x00002e67d537aa36 }, /* 3.356 */ { 219, 512, 0x6e98ed6f6c38e82f, 0x00002e9720626789 }, /* 2.697 */ { 220, 512, 0x2e01edba33fddac7, 0x00002f407c6b0198 }, /* 2.979 */ { 221, 512, 0x559d02e1f5f57ccc, 0x00002fb6a5ab4f24 }, /* 2.858 */ { 222, 512, 0xac18f5a916adcd8e, 0x0000304ae1c5c57e }, /* 3.258 */ { 223, 512, 0x15789fbaddb86f4b, 0x0000306f6e019c78 }, /* 2.693 */ { 224, 512, 0xf4a9c36d5bc4c408, 0x000030da40434213 }, /* 3.259 */ { 225, 512, 0xf640f90fd2727f44, 0x00003189ed37b90c }, /* 2.733 */ { 226, 512, 0xb5313d390d61884a, 0x000031e152616b37 }, /* 3.235 */ { 227, 512, 0x4bae6b3ce9160939, 0x0000321f40aeac42 }, /* 2.983 */ { 228, 512, 0x838c34480f1a66a1, 0x000032f389c0f78e }, /* 3.308 */ { 229, 512, 0xb1c4a52c8e3d6060, 0x0000330062a40284 }, /* 2.715 */ { 230, 512, 0xe0f1110c6d0ed822, 0x0000338be435644f }, /* 3.540 */ { 231, 512, 0x9f1a8ccdcea68d4b, 0x000034045a4e97e1 }, /* 2.779 */ { 232, 512, 0x3261ed62223f3099, 0x000034702cfc401c }, /* 3.084 */ { 233, 512, 0xf2191e2311022d65, 0x00003509dd19c9fc }, /* 2.987 */ { 234, 512, 0xf102a395c2033abc, 0x000035654dc96fae }, /* 3.341 */ { 235, 512, 0x11fe378f027906b6, 0x000035b5193b0264 }, /* 2.793 */ { 236, 512, 0xf777f2c026b337aa, 0x000036704f5d9297 }, /* 3.518 */ { 237, 512, 0x1b04e9c2ee143f32, 0x000036dfbb7af218 }, /* 2.962 */ { 238, 512, 0x2fcec95266f9352c, 0x00003785c8df24a9 }, /* 3.196 */ { 239, 512, 0xfe2b0e47e427dd85, 0x000037cbdf5da729 }, /* 2.914 */ { 240, 512, 0x72b49bf2225f6c6d, 0x0000382227c15855 }, /* 3.408 */ { 241, 512, 0x50486b43df7df9c7, 0x0000389b88be6453 }, /* 2.903 */ { 242, 512, 0x5192a3e53181c8ab, 0x000038ddf3d67263 }, /* 3.778 */ { 243, 512, 0xe9f5d8365296fd5e, 0x0000399f1c6c9e9c }, /* 3.026 */ { 244, 512, 0xc740263f0301efa8, 0x00003a147146512d }, /* 3.347 */ { 245, 512, 0x23cd0f2b5671e67d, 0x00003ab10bcc0d9d }, /* 3.212 */ { 246, 512, 0x002ccc7e5cd41390, 0x00003ad6cd14a6c0 }, /* 3.482 */ { 247, 512, 0x9aafb3c02544b31b, 0x00003b8cb8779fb0 }, /* 3.146 */ { 248, 512, 0x72ba07a78b121999, 0x00003c24142a5a3f }, /* 3.626 */ { 249, 512, 0x3d784aa58edfc7b4, 0x00003cd084817d99 }, /* 2.952 */ { 250, 512, 0xaab750424d8004af, 0x00003d506a8e098e }, /* 3.463 */ { 251, 512, 0x84403fcf8e6b5ca2, 0x00003d4c54c2aec4 }, /* 3.131 */ { 252, 512, 0x71eb7455ec98e207, 0x00003e655715cf2c }, /* 3.538 */ { 253, 512, 0xd752b4f19301595b, 0x00003ecd7b2ca5ac }, /* 2.974 */ { 254, 512, 0xc4674129750499de, 0x00003e99e86d3e95 }, /* 3.843 */ { 255, 512, 0x9772baff5cd12ef5, 0x00003f895c019841 }, /* 3.088 */ }; /* * Verify the map is valid. Each device index must appear exactly * once in every row, and the permutation array checksum must match. */ static int verify_perms(uint8_t *perms, uint64_t children, uint64_t nperms, uint64_t checksum) { int countssz = sizeof (uint16_t) * children; uint16_t *counts = kmem_zalloc(countssz, KM_SLEEP); for (int i = 0; i < nperms; i++) { for (int j = 0; j < children; j++) { uint8_t val = perms[(i * children) + j]; if (val >= children || counts[val] != i) { kmem_free(counts, countssz); return (EINVAL); } counts[val]++; } } if (checksum != 0) { int permssz = sizeof (uint8_t) * children * nperms; zio_cksum_t cksum; fletcher_4_native_varsize(perms, permssz, &cksum); if (checksum != cksum.zc_word[0]) { kmem_free(counts, countssz); return (ECKSUM); } } kmem_free(counts, countssz); return (0); } /* * Generate the permutation array for the draid_map_t. These maps control * the placement of all data in a dRAID. Therefore it's critical that the * seed always generates the same mapping. We provide our own pseudo-random * number generator for this purpose. */ int vdev_draid_generate_perms(const draid_map_t *map, uint8_t **permsp) { VERIFY3U(map->dm_children, >=, VDEV_DRAID_MIN_CHILDREN); VERIFY3U(map->dm_children, <=, VDEV_DRAID_MAX_CHILDREN); VERIFY3U(map->dm_seed, !=, 0); VERIFY3U(map->dm_nperms, !=, 0); VERIFY3P(map->dm_perms, ==, NULL); #ifdef _KERNEL /* * The kernel code always provides both a map_seed and checksum. * Only the tests/zfs-tests/cmd/draid/draid.c utility will provide * a zero checksum when generating new candidate maps. */ VERIFY3U(map->dm_checksum, !=, 0); #endif uint64_t children = map->dm_children; uint64_t nperms = map->dm_nperms; int rowsz = sizeof (uint8_t) * children; int permssz = rowsz * nperms; uint8_t *perms; /* Allocate the permutation array */ perms = vmem_alloc(permssz, KM_SLEEP); /* Setup an initial row with a known pattern */ uint8_t *initial_row = kmem_alloc(rowsz, KM_SLEEP); for (int i = 0; i < children; i++) initial_row[i] = i; uint64_t draid_seed[2] = { VDEV_DRAID_SEED, map->dm_seed }; uint8_t *current_row, *previous_row = initial_row; /* * Perform a Fisher-Yates shuffle of each row using the previous * row as the starting point. An initial_row with known pattern * is used as the input for the first row. */ for (int i = 0; i < nperms; i++) { current_row = &perms[i * children]; memcpy(current_row, previous_row, rowsz); for (int j = children - 1; j > 0; j--) { uint64_t k = vdev_draid_rand(draid_seed) % (j + 1); uint8_t val = current_row[j]; current_row[j] = current_row[k]; current_row[k] = val; } previous_row = current_row; } kmem_free(initial_row, rowsz); int error = verify_perms(perms, children, nperms, map->dm_checksum); if (error) { vmem_free(perms, permssz); return (error); } *permsp = perms; return (0); } /* * Lookup the fixed draid_map_t for the requested number of children. */ int vdev_draid_lookup_map(uint64_t children, const draid_map_t **mapp) { for (int i = 0; i <= VDEV_DRAID_MAX_MAPS; i++) { if (draid_maps[i].dm_children == children) { *mapp = &draid_maps[i]; return (0); } } return (ENOENT); } /* * Lookup the permutation array and iteration id for the provided offset. */ static void vdev_draid_get_perm(vdev_draid_config_t *vdc, uint64_t pindex, uint8_t **base, uint64_t *iter) { uint64_t ncols = vdc->vdc_children; uint64_t poff = pindex % (vdc->vdc_nperms * ncols); *base = vdc->vdc_perms + (poff / ncols) * ncols; *iter = poff % ncols; } static inline uint64_t vdev_draid_permute_id(vdev_draid_config_t *vdc, uint8_t *base, uint64_t iter, uint64_t index) { return ((base[index] + iter) % vdc->vdc_children); } /* * Return the asize which is the psize rounded up to a full group width. * i.e. vdev_draid_psize_to_asize(). */ static uint64_t vdev_draid_asize(vdev_t *vd, uint64_t psize) { vdev_draid_config_t *vdc = vd->vdev_tsd; uint64_t ashift = vd->vdev_ashift; ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); uint64_t rows = ((psize - 1) / (vdc->vdc_ndata << ashift)) + 1; uint64_t asize = (rows * vdc->vdc_groupwidth) << ashift; ASSERT3U(asize, !=, 0); ASSERT3U(asize % (vdc->vdc_groupwidth), ==, 0); return (asize); } /* * Deflate the asize to the psize, this includes stripping parity. */ uint64_t vdev_draid_asize_to_psize(vdev_t *vd, uint64_t asize) { vdev_draid_config_t *vdc = vd->vdev_tsd; ASSERT0(asize % vdc->vdc_groupwidth); return ((asize / vdc->vdc_groupwidth) * vdc->vdc_ndata); } /* * Convert a logical offset to the corresponding group number. */ static uint64_t vdev_draid_offset_to_group(vdev_t *vd, uint64_t offset) { vdev_draid_config_t *vdc = vd->vdev_tsd; ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); return (offset / vdc->vdc_groupsz); } /* * Convert a group number to the logical starting offset for that group. */ static uint64_t vdev_draid_group_to_offset(vdev_t *vd, uint64_t group) { vdev_draid_config_t *vdc = vd->vdev_tsd; ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); return (group * vdc->vdc_groupsz); } static void vdev_draid_map_free_vsd(zio_t *zio) { raidz_map_t *rm = zio->io_vsd; ASSERT0(rm->rm_freed); rm->rm_freed = B_TRUE; if (rm->rm_reports == 0) { vdev_raidz_map_free(rm); } } /*ARGSUSED*/ static void vdev_draid_cksum_free(void *arg, size_t ignored) { raidz_map_t *rm = arg; ASSERT3U(rm->rm_reports, >, 0); if (--rm->rm_reports == 0 && rm->rm_freed) vdev_raidz_map_free(rm); } static void vdev_draid_cksum_finish(zio_cksum_report_t *zcr, const abd_t *good_data) { raidz_map_t *rm = zcr->zcr_cbdata; const size_t c = zcr->zcr_cbinfo; uint64_t skip_size = zcr->zcr_sector; uint64_t parity_size; size_t x, offset, size; if (good_data == NULL) { zfs_ereport_finish_checksum(zcr, NULL, NULL, B_FALSE); return; } /* * Detailed cksum reporting is currently only supported for single * row draid mappings, this covers the vast majority of zios. Only * a dRAID zio which spans groups will have multiple rows. */ if (rm->rm_nrows != 1) { zfs_ereport_finish_checksum(zcr, NULL, NULL, B_FALSE); return; } raidz_row_t *rr = rm->rm_row[0]; const abd_t *good = NULL; const abd_t *bad = rr->rr_col[c].rc_abd; if (c < rr->rr_firstdatacol) { /* * The first time through, calculate the parity blocks for * the good data (this relies on the fact that the good * data never changes for a given logical zio) */ if (rr->rr_col[0].rc_gdata == NULL) { abd_t *bad_parity[VDEV_DRAID_MAXPARITY]; /* * Set up the rr_col[]s to generate the parity for * good_data, first saving the parity bufs and * replacing them with buffers to hold the result. */ for (x = 0; x < rr->rr_firstdatacol; x++) { bad_parity[x] = rr->rr_col[x].rc_abd; rr->rr_col[x].rc_abd = rr->rr_col[x].rc_gdata = abd_alloc_sametype(rr->rr_col[x].rc_abd, rr->rr_col[x].rc_size); } /* * Fill in the data columns from good_data being * careful to pad short columns and empty columns * with a skip sector. */ uint64_t good_size = abd_get_size((abd_t *)good_data); offset = 0; for (; x < rr->rr_cols; x++) { - abd_put(rr->rr_col[x].rc_abd); + abd_free(rr->rr_col[x].rc_abd); if (offset == good_size) { /* empty data column (small write) */ rr->rr_col[x].rc_abd = abd_get_zeros(skip_size); } else if (x < rr->rr_bigcols) { /* this is a "big column" */ size = rr->rr_col[x].rc_size; rr->rr_col[x].rc_abd = abd_get_offset_size( (abd_t *)good_data, offset, size); offset += size; } else { /* short data column, add skip sector */ size = rr->rr_col[x].rc_size -skip_size; rr->rr_col[x].rc_abd = abd_alloc( rr->rr_col[x].rc_size, B_TRUE); abd_copy_off(rr->rr_col[x].rc_abd, (abd_t *)good_data, 0, offset, size); abd_zero_off(rr->rr_col[x].rc_abd, size, skip_size); offset += size; } } /* * Construct the parity from the good data. */ vdev_raidz_generate_parity_row(rm, rr); /* restore everything back to its original state */ for (x = 0; x < rr->rr_firstdatacol; x++) rr->rr_col[x].rc_abd = bad_parity[x]; offset = 0; for (x = rr->rr_firstdatacol; x < rr->rr_cols; x++) { - if (offset == good_size || x < rr->rr_bigcols) - abd_put(rr->rr_col[x].rc_abd); - else - abd_free(rr->rr_col[x].rc_abd); - + abd_free(rr->rr_col[x].rc_abd); rr->rr_col[x].rc_abd = abd_get_offset_size( rr->rr_abd_copy, offset, rr->rr_col[x].rc_size); offset += rr->rr_col[x].rc_size; } } ASSERT3P(rr->rr_col[c].rc_gdata, !=, NULL); good = abd_get_offset_size(rr->rr_col[c].rc_gdata, 0, rr->rr_col[c].rc_size); } else { /* adjust good_data to point at the start of our column */ parity_size = size = rr->rr_col[0].rc_size; if (c >= rr->rr_bigcols) { size -= skip_size; zcr->zcr_length = size; } /* empty column */ if (size == 0) { zfs_ereport_finish_checksum(zcr, NULL, NULL, B_TRUE); return; } offset = 0; for (x = rr->rr_firstdatacol; x < c; x++) { if (x < rr->rr_bigcols) { offset += parity_size; } else { offset += parity_size - skip_size; } } good = abd_get_offset_size((abd_t *)good_data, offset, size); } /* we drop the ereport if it ends up that the data was good */ zfs_ereport_finish_checksum(zcr, good, bad, B_TRUE); - abd_put((abd_t *)good); + abd_free((abd_t *)good); } /* * Invoked indirectly by zfs_ereport_start_checksum(), called * below when our read operation fails completely. The main point * is to keep a copy of everything we read from disk, so that at * vdev_draid_cksum_finish() time we can compare it with the good data. */ static void vdev_draid_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *arg) { size_t c = (size_t)(uintptr_t)arg; raidz_map_t *rm = zio->io_vsd; /* set up the report and bump the refcount */ zcr->zcr_cbdata = rm; zcr->zcr_cbinfo = c; zcr->zcr_finish = vdev_draid_cksum_finish; zcr->zcr_free = vdev_draid_cksum_free; rm->rm_reports++; ASSERT3U(rm->rm_reports, >, 0); if (rm->rm_row[0]->rr_abd_copy != NULL) return; /* * It's the first time we're called for this raidz_map_t, so we need * to copy the data aside; there's no guarantee that our zio's buffer * won't be re-used for something else. * * Our parity data is already in separate buffers, so there's no need * to copy them. Furthermore, all columns should have been expanded * by vdev_draid_map_alloc_empty() when attempting reconstruction. */ for (int i = 0; i < rm->rm_nrows; i++) { raidz_row_t *rr = rm->rm_row[i]; size_t offset = 0; size_t size = 0; for (c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { ASSERT3U(rr->rr_col[c].rc_size, ==, rr->rr_col[0].rc_size); size += rr->rr_col[c].rc_size; } rr->rr_abd_copy = abd_alloc_for_io(size, B_FALSE); for (c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { raidz_col_t *col = &rr->rr_col[c]; abd_t *tmp = abd_get_offset_size(rr->rr_abd_copy, offset, col->rc_size); abd_copy(tmp, col->rc_abd, col->rc_size); - - if (abd_is_gang(col->rc_abd)) - abd_free(col->rc_abd); - else - abd_put(col->rc_abd); + abd_free(col->rc_abd); col->rc_abd = tmp; offset += col->rc_size; } ASSERT3U(offset, ==, size); } } const zio_vsd_ops_t vdev_draid_vsd_ops = { .vsd_free = vdev_draid_map_free_vsd, .vsd_cksum_report = vdev_draid_cksum_report }; /* * Full stripe writes. When writing, all columns (D+P) are required. Parity * is calculated over all the columns, including empty zero filled sectors, * and each is written to disk. While only the data columns are needed for * a normal read, all of the columns are required for reconstruction when * performing a sequential resilver. * * For "big columns" it's sufficient to map the correct range of the zio ABD. * Partial columns require allocating a gang ABD in order to zero fill the * empty sectors. When the column is empty a zero filled sector must be * mapped. In all cases the data ABDs must be the same size as the parity * ABDs (e.g. rc->rc_size == parity_size). */ static void vdev_draid_map_alloc_write(zio_t *zio, uint64_t abd_offset, raidz_row_t *rr) { uint64_t skip_size = 1ULL << zio->io_vd->vdev_top->vdev_ashift; uint64_t parity_size = rr->rr_col[0].rc_size; uint64_t abd_off = abd_offset; ASSERT3U(zio->io_type, ==, ZIO_TYPE_WRITE); ASSERT3U(parity_size, ==, abd_get_size(rr->rr_col[0].rc_abd)); for (uint64_t c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { raidz_col_t *rc = &rr->rr_col[c]; if (rc->rc_size == 0) { /* empty data column (small write), add a skip sector */ ASSERT3U(skip_size, ==, parity_size); rc->rc_abd = abd_get_zeros(skip_size); } else if (rc->rc_size == parity_size) { /* this is a "big column" */ - rc->rc_abd = abd_get_offset_size(zio->io_abd, - abd_off, rc->rc_size); + rc->rc_abd = abd_get_offset_struct(&rc->rc_abdstruct, + zio->io_abd, abd_off, rc->rc_size); } else { /* short data column, add a skip sector */ ASSERT3U(rc->rc_size + skip_size, ==, parity_size); - rc->rc_abd = abd_alloc_gang_abd(); + rc->rc_abd = abd_alloc_gang(); abd_gang_add(rc->rc_abd, abd_get_offset_size( zio->io_abd, abd_off, rc->rc_size), B_TRUE); abd_gang_add(rc->rc_abd, abd_get_zeros(skip_size), B_TRUE); } ASSERT3U(abd_get_size(rc->rc_abd), ==, parity_size); abd_off += rc->rc_size; rc->rc_size = parity_size; } IMPLY(abd_offset != 0, abd_off == zio->io_size); } /* * Scrub/resilver reads. In order to store the contents of the skip sectors * an additional ABD is allocated. The columns are handled in the same way * as a full stripe write except instead of using the zero ABD the newly * allocated skip ABD is used to back the skip sectors. In all cases the * data ABD must be the same size as the parity ABDs. */ static void vdev_draid_map_alloc_scrub(zio_t *zio, uint64_t abd_offset, raidz_row_t *rr) { uint64_t skip_size = 1ULL << zio->io_vd->vdev_top->vdev_ashift; uint64_t parity_size = rr->rr_col[0].rc_size; uint64_t abd_off = abd_offset; uint64_t skip_off = 0; ASSERT3U(zio->io_type, ==, ZIO_TYPE_READ); ASSERT3P(rr->rr_abd_empty, ==, NULL); if (rr->rr_nempty > 0) { rr->rr_abd_empty = abd_alloc_linear(rr->rr_nempty * skip_size, B_FALSE); } for (uint64_t c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { raidz_col_t *rc = &rr->rr_col[c]; if (rc->rc_size == 0) { /* empty data column (small read), add a skip sector */ ASSERT3U(skip_size, ==, parity_size); ASSERT3U(rr->rr_nempty, !=, 0); rc->rc_abd = abd_get_offset_size(rr->rr_abd_empty, skip_off, skip_size); skip_off += skip_size; } else if (rc->rc_size == parity_size) { /* this is a "big column" */ - rc->rc_abd = abd_get_offset_size(zio->io_abd, - abd_off, rc->rc_size); + rc->rc_abd = abd_get_offset_struct(&rc->rc_abdstruct, + zio->io_abd, abd_off, rc->rc_size); } else { /* short data column, add a skip sector */ ASSERT3U(rc->rc_size + skip_size, ==, parity_size); ASSERT3U(rr->rr_nempty, !=, 0); - rc->rc_abd = abd_alloc_gang_abd(); + rc->rc_abd = abd_alloc_gang(); abd_gang_add(rc->rc_abd, abd_get_offset_size( zio->io_abd, abd_off, rc->rc_size), B_TRUE); abd_gang_add(rc->rc_abd, abd_get_offset_size( rr->rr_abd_empty, skip_off, skip_size), B_TRUE); skip_off += skip_size; } uint64_t abd_size = abd_get_size(rc->rc_abd); ASSERT3U(abd_size, ==, abd_get_size(rr->rr_col[0].rc_abd)); /* * Increase rc_size so the skip ABD is included in subsequent * parity calculations. */ abd_off += rc->rc_size; rc->rc_size = abd_size; } IMPLY(abd_offset != 0, abd_off == zio->io_size); ASSERT3U(skip_off, ==, rr->rr_nempty * skip_size); } /* * Normal reads. In this common case only the columns containing data * are read in to the zio ABDs. Neither the parity columns or empty skip * sectors are read unless the checksum fails verification. In which case * vdev_raidz_read_all() will call vdev_draid_map_alloc_empty() to expand * the raid map in order to allow reconstruction using the parity data and * skip sectors. */ static void vdev_draid_map_alloc_read(zio_t *zio, uint64_t abd_offset, raidz_row_t *rr) { uint64_t abd_off = abd_offset; ASSERT3U(zio->io_type, ==, ZIO_TYPE_READ); for (uint64_t c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { raidz_col_t *rc = &rr->rr_col[c]; if (rc->rc_size > 0) { - rc->rc_abd = abd_get_offset_size(zio->io_abd, - abd_off, rc->rc_size); + rc->rc_abd = abd_get_offset_struct(&rc->rc_abdstruct, + zio->io_abd, abd_off, rc->rc_size); abd_off += rc->rc_size; } } IMPLY(abd_offset != 0, abd_off == zio->io_size); } /* * Converts a normal "read" raidz_row_t to a "scrub" raidz_row_t. The key * difference is that an ABD is allocated to back skip sectors so they may * be read in to memory, verified, and repaired if needed. */ void vdev_draid_map_alloc_empty(zio_t *zio, raidz_row_t *rr) { uint64_t skip_size = 1ULL << zio->io_vd->vdev_top->vdev_ashift; uint64_t parity_size = rr->rr_col[0].rc_size; uint64_t skip_off = 0; ASSERT3U(zio->io_type, ==, ZIO_TYPE_READ); ASSERT3P(rr->rr_abd_empty, ==, NULL); if (rr->rr_nempty > 0) { rr->rr_abd_empty = abd_alloc_linear(rr->rr_nempty * skip_size, B_FALSE); } for (uint64_t c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { raidz_col_t *rc = &rr->rr_col[c]; if (rc->rc_size == 0) { /* empty data column (small read), add a skip sector */ ASSERT3U(skip_size, ==, parity_size); ASSERT3U(rr->rr_nempty, !=, 0); ASSERT3P(rc->rc_abd, ==, NULL); rc->rc_abd = abd_get_offset_size(rr->rr_abd_empty, skip_off, skip_size); skip_off += skip_size; } else if (rc->rc_size == parity_size) { /* this is a "big column", nothing to add */ ASSERT3P(rc->rc_abd, !=, NULL); } else { /* short data column, add a skip sector */ ASSERT3U(rc->rc_size + skip_size, ==, parity_size); ASSERT3U(rr->rr_nempty, !=, 0); ASSERT3P(rc->rc_abd, !=, NULL); ASSERT(!abd_is_gang(rc->rc_abd)); abd_t *read_abd = rc->rc_abd; - rc->rc_abd = abd_alloc_gang_abd(); + rc->rc_abd = abd_alloc_gang(); abd_gang_add(rc->rc_abd, read_abd, B_TRUE); abd_gang_add(rc->rc_abd, abd_get_offset_size( rr->rr_abd_empty, skip_off, skip_size), B_TRUE); skip_off += skip_size; } /* * Increase rc_size so the empty ABD is included in subsequent * parity calculations. */ rc->rc_size = parity_size; } ASSERT3U(skip_off, ==, rr->rr_nempty * skip_size); } /* * Given a logical address within a dRAID configuration, return the physical * address on the first drive in the group that this address maps to * (at position 'start' in permutation number 'perm'). */ static uint64_t vdev_draid_logical_to_physical(vdev_t *vd, uint64_t logical_offset, uint64_t *perm, uint64_t *start) { vdev_draid_config_t *vdc = vd->vdev_tsd; /* b is the dRAID (parent) sector offset. */ uint64_t ashift = vd->vdev_top->vdev_ashift; uint64_t b_offset = logical_offset >> ashift; /* * The height of a row in units of the vdev's minimum sector size. * This is the amount of data written to each disk of each group * in a given permutation. */ uint64_t rowheight_sectors = VDEV_DRAID_ROWHEIGHT >> ashift; /* * We cycle through a disk permutation every groupsz * ngroups chunk * of address space. Note that ngroups * groupsz must be a multiple * of the number of data drives (ndisks) in order to guarantee * alignment. So, for example, if our row height is 16MB, our group * size is 10, and there are 13 data drives in the draid, then ngroups * will be 13, we will change permutation every 2.08GB and each * disk will have 160MB of data per chunk. */ uint64_t groupwidth = vdc->vdc_groupwidth; uint64_t ngroups = vdc->vdc_ngroups; uint64_t ndisks = vdc->vdc_ndisks; /* * groupstart is where the group this IO will land in "starts" in * the permutation array. */ uint64_t group = logical_offset / vdc->vdc_groupsz; uint64_t groupstart = (group * groupwidth) % ndisks; ASSERT3U(groupstart + groupwidth, <=, ndisks + groupstart); *start = groupstart; /* b_offset is the sector offset within a group chunk */ b_offset = b_offset % (rowheight_sectors * groupwidth); ASSERT0(b_offset % groupwidth); /* * Find the starting byte offset on each child vdev: * - within a permutation there are ngroups groups spread over the * rows, where each row covers a slice portion of the disk * - each permutation has (groupwidth * ngroups) / ndisks rows * - so each permutation covers rows * slice portion of the disk * - so we need to find the row where this IO group target begins */ *perm = group / ngroups; uint64_t row = (*perm * ((groupwidth * ngroups) / ndisks)) + (((group % ngroups) * groupwidth) / ndisks); return (((rowheight_sectors * row) + (b_offset / groupwidth)) << ashift); } static uint64_t vdev_draid_map_alloc_row(zio_t *zio, raidz_row_t **rrp, uint64_t io_offset, uint64_t abd_offset, uint64_t abd_size) { vdev_t *vd = zio->io_vd; vdev_draid_config_t *vdc = vd->vdev_tsd; uint64_t ashift = vd->vdev_top->vdev_ashift; uint64_t io_size = abd_size; uint64_t io_asize = vdev_draid_asize(vd, io_size); uint64_t group = vdev_draid_offset_to_group(vd, io_offset); uint64_t start_offset = vdev_draid_group_to_offset(vd, group + 1); /* * Limit the io_size to the space remaining in the group. A second * row in the raidz_map_t is created for the remainder. */ if (io_offset + io_asize > start_offset) { io_size = vdev_draid_asize_to_psize(vd, start_offset - io_offset); } /* * At most a block may span the logical end of one group and the start * of the next group. Therefore, at the end of a group the io_size must * span the group width evenly and the remainder must be aligned to the * start of the next group. */ IMPLY(abd_offset == 0 && io_size < zio->io_size, (io_asize >> ashift) % vdc->vdc_groupwidth == 0); IMPLY(abd_offset != 0, vdev_draid_group_to_offset(vd, group) == io_offset); /* Lookup starting byte offset on each child vdev */ uint64_t groupstart, perm; uint64_t physical_offset = vdev_draid_logical_to_physical(vd, io_offset, &perm, &groupstart); /* * If there is less than groupwidth drives available after the group * start, the group is going to wrap onto the next row. 'wrap' is the * group disk number that starts on the next row. */ uint64_t ndisks = vdc->vdc_ndisks; uint64_t groupwidth = vdc->vdc_groupwidth; uint64_t wrap = groupwidth; if (groupstart + groupwidth > ndisks) wrap = ndisks - groupstart; /* The io size in units of the vdev's minimum sector size. */ const uint64_t psize = io_size >> ashift; /* * "Quotient": The number of data sectors for this stripe on all but * the "big column" child vdevs that also contain "remainder" data. */ uint64_t q = psize / vdc->vdc_ndata; /* * "Remainder": The number of partial stripe data sectors in this I/O. * This will add a sector to some, but not all, child vdevs. */ uint64_t r = psize - q * vdc->vdc_ndata; /* The number of "big columns" - those which contain remainder data. */ uint64_t bc = (r == 0 ? 0 : r + vdc->vdc_nparity); ASSERT3U(bc, <, groupwidth); /* The total number of data and parity sectors for this I/O. */ uint64_t tot = psize + (vdc->vdc_nparity * (q + (r == 0 ? 0 : 1))); raidz_row_t *rr; rr = kmem_alloc(offsetof(raidz_row_t, rr_col[groupwidth]), KM_SLEEP); rr->rr_cols = groupwidth; rr->rr_scols = groupwidth; rr->rr_bigcols = bc; rr->rr_missingdata = 0; rr->rr_missingparity = 0; rr->rr_firstdatacol = vdc->vdc_nparity; rr->rr_abd_copy = NULL; rr->rr_abd_empty = NULL; #ifdef ZFS_DEBUG rr->rr_offset = io_offset; rr->rr_size = io_size; #endif *rrp = rr; uint8_t *base; uint64_t iter, asize = 0; vdev_draid_get_perm(vdc, perm, &base, &iter); for (uint64_t i = 0; i < groupwidth; i++) { raidz_col_t *rc = &rr->rr_col[i]; uint64_t c = (groupstart + i) % ndisks; /* increment the offset if we wrap to the next row */ if (i == wrap) physical_offset += VDEV_DRAID_ROWHEIGHT; rc->rc_devidx = vdev_draid_permute_id(vdc, base, iter, c); rc->rc_offset = physical_offset; rc->rc_abd = NULL; rc->rc_gdata = NULL; rc->rc_orig_data = NULL; rc->rc_error = 0; rc->rc_tried = 0; rc->rc_skipped = 0; rc->rc_repair = 0; rc->rc_need_orig_restore = B_FALSE; if (q == 0 && i >= bc) rc->rc_size = 0; else if (i < bc) rc->rc_size = (q + 1) << ashift; else rc->rc_size = q << ashift; asize += rc->rc_size; } ASSERT3U(asize, ==, tot << ashift); rr->rr_nempty = roundup(tot, groupwidth) - tot; IMPLY(bc > 0, rr->rr_nempty == groupwidth - bc); /* Allocate buffers for the parity columns */ for (uint64_t c = 0; c < rr->rr_firstdatacol; c++) { raidz_col_t *rc = &rr->rr_col[c]; rc->rc_abd = abd_alloc_linear(rc->rc_size, B_FALSE); } /* * Map buffers for data columns and allocate/map buffers for skip * sectors. There are three distinct cases for dRAID which are * required to support sequential rebuild. */ if (zio->io_type == ZIO_TYPE_WRITE) { vdev_draid_map_alloc_write(zio, abd_offset, rr); } else if ((rr->rr_nempty > 0) && (zio->io_flags & (ZIO_FLAG_SCRUB | ZIO_FLAG_RESILVER))) { vdev_draid_map_alloc_scrub(zio, abd_offset, rr); } else { ASSERT3U(zio->io_type, ==, ZIO_TYPE_READ); vdev_draid_map_alloc_read(zio, abd_offset, rr); } return (io_size); } /* * Allocate the raidz mapping to be applied to the dRAID I/O. The parity * calculations for dRAID are identical to raidz however there are a few * differences in the layout. * * - dRAID always allocates a full stripe width. Any extra sectors due * this padding are zero filled and written to disk. They will be read * back during a scrub or repair operation since they are included in * the parity calculation. This property enables sequential resilvering. * * - When the block at the logical offset spans redundancy groups then two * rows are allocated in the raidz_map_t. One row resides at the end of * the first group and the other at the start of the following group. */ static raidz_map_t * vdev_draid_map_alloc(zio_t *zio) { raidz_row_t *rr[2]; uint64_t abd_offset = 0; uint64_t abd_size = zio->io_size; uint64_t io_offset = zio->io_offset; uint64_t size; int nrows = 1; size = vdev_draid_map_alloc_row(zio, &rr[0], io_offset, abd_offset, abd_size); if (size < abd_size) { vdev_t *vd = zio->io_vd; io_offset += vdev_draid_asize(vd, size); abd_offset += size; abd_size -= size; nrows++; ASSERT3U(io_offset, ==, vdev_draid_group_to_offset( vd, vdev_draid_offset_to_group(vd, io_offset))); ASSERT3U(abd_offset, <, zio->io_size); ASSERT3U(abd_size, !=, 0); size = vdev_draid_map_alloc_row(zio, &rr[1], io_offset, abd_offset, abd_size); VERIFY3U(size, ==, abd_size); } raidz_map_t *rm; rm = kmem_zalloc(offsetof(raidz_map_t, rm_row[nrows]), KM_SLEEP); rm->rm_ops = vdev_raidz_math_get_ops(); rm->rm_nrows = nrows; rm->rm_row[0] = rr[0]; if (nrows == 2) rm->rm_row[1] = rr[1]; zio->io_vsd = rm; zio->io_vsd_ops = &vdev_draid_vsd_ops; return (rm); } /* * Given an offset into a dRAID return the next group width aligned offset * which can be used to start an allocation. */ static uint64_t vdev_draid_get_astart(vdev_t *vd, const uint64_t start) { vdev_draid_config_t *vdc = vd->vdev_tsd; ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); return (roundup(start, vdc->vdc_groupwidth << vd->vdev_ashift)); } /* * Allocatable space for dRAID is (children - nspares) * sizeof(smallest child) * rounded down to the last full slice. So each child must provide at least * 1 / (children - nspares) of its asize. */ static uint64_t vdev_draid_min_asize(vdev_t *vd) { vdev_draid_config_t *vdc = vd->vdev_tsd; ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); return ((vd->vdev_min_asize + vdc->vdc_ndisks - 1) / (vdc->vdc_ndisks)); } /* * When using dRAID the minimum allocation size is determined by the number * of data disks in the redundancy group. Full stripes are always used. */ static uint64_t vdev_draid_min_alloc(vdev_t *vd) { vdev_draid_config_t *vdc = vd->vdev_tsd; ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); return (vdc->vdc_ndata << vd->vdev_ashift); } /* * Returns true if the txg range does not exist on any leaf vdev. * * A dRAID spare does not fit into the DTL model. While it has child vdevs * there is no redundancy among them, and the effective child vdev is * determined by offset. Essentially we do a vdev_dtl_reassess() on the * fly by replacing a dRAID spare with the child vdev under the offset. * Note that it is a recursive process because the child vdev can be * another dRAID spare and so on. */ boolean_t vdev_draid_missing(vdev_t *vd, uint64_t physical_offset, uint64_t txg, uint64_t size) { if (vd->vdev_ops == &vdev_spare_ops || vd->vdev_ops == &vdev_replacing_ops) { /* * Check all of the readable children, if any child * contains the txg range the data it is not missing. */ for (int c = 0; c < vd->vdev_children; c++) { vdev_t *cvd = vd->vdev_child[c]; if (!vdev_readable(cvd)) continue; if (!vdev_draid_missing(cvd, physical_offset, txg, size)) return (B_FALSE); } return (B_TRUE); } if (vd->vdev_ops == &vdev_draid_spare_ops) { /* * When sequentially resilvering we don't have a proper * txg range so instead we must presume all txgs are * missing on this vdev until the resilver completes. */ if (vd->vdev_rebuild_txg != 0) return (B_TRUE); /* * DTL_MISSING is set for all prior txgs when a resilver * is started in spa_vdev_attach(). */ if (vdev_dtl_contains(vd, DTL_MISSING, txg, size)) return (B_TRUE); /* * Consult the DTL on the relevant vdev. Either a vdev * leaf or spare/replace mirror child may be returned so * we must recursively call vdev_draid_missing_impl(). */ vd = vdev_draid_spare_get_child(vd, physical_offset); if (vd == NULL) return (B_TRUE); return (vdev_draid_missing(vd, physical_offset, txg, size)); } return (vdev_dtl_contains(vd, DTL_MISSING, txg, size)); } /* * Returns true if the txg is only partially replicated on the leaf vdevs. */ static boolean_t vdev_draid_partial(vdev_t *vd, uint64_t physical_offset, uint64_t txg, uint64_t size) { if (vd->vdev_ops == &vdev_spare_ops || vd->vdev_ops == &vdev_replacing_ops) { /* * Check all of the readable children, if any child is * missing the txg range then it is partially replicated. */ for (int c = 0; c < vd->vdev_children; c++) { vdev_t *cvd = vd->vdev_child[c]; if (!vdev_readable(cvd)) continue; if (vdev_draid_partial(cvd, physical_offset, txg, size)) return (B_TRUE); } return (B_FALSE); } if (vd->vdev_ops == &vdev_draid_spare_ops) { /* * When sequentially resilvering we don't have a proper * txg range so instead we must presume all txgs are * missing on this vdev until the resilver completes. */ if (vd->vdev_rebuild_txg != 0) return (B_TRUE); /* * DTL_MISSING is set for all prior txgs when a resilver * is started in spa_vdev_attach(). */ if (vdev_dtl_contains(vd, DTL_MISSING, txg, size)) return (B_TRUE); /* * Consult the DTL on the relevant vdev. Either a vdev * leaf or spare/replace mirror child may be returned so * we must recursively call vdev_draid_missing_impl(). */ vd = vdev_draid_spare_get_child(vd, physical_offset); if (vd == NULL) return (B_TRUE); return (vdev_draid_partial(vd, physical_offset, txg, size)); } return (vdev_dtl_contains(vd, DTL_MISSING, txg, size)); } /* * Determine if the vdev is readable at the given offset. */ boolean_t vdev_draid_readable(vdev_t *vd, uint64_t physical_offset) { if (vd->vdev_ops == &vdev_draid_spare_ops) { vd = vdev_draid_spare_get_child(vd, physical_offset); if (vd == NULL) return (B_FALSE); } if (vd->vdev_ops == &vdev_spare_ops || vd->vdev_ops == &vdev_replacing_ops) { for (int c = 0; c < vd->vdev_children; c++) { vdev_t *cvd = vd->vdev_child[c]; if (!vdev_readable(cvd)) continue; if (vdev_draid_readable(cvd, physical_offset)) return (B_TRUE); } return (B_FALSE); } return (vdev_readable(vd)); } /* * Returns the first distributed spare found under the provided vdev tree. */ static vdev_t * vdev_draid_find_spare(vdev_t *vd) { if (vd->vdev_ops == &vdev_draid_spare_ops) return (vd); for (int c = 0; c < vd->vdev_children; c++) { vdev_t *svd = vdev_draid_find_spare(vd->vdev_child[c]); if (svd != NULL) return (svd); } return (NULL); } /* * Returns B_TRUE if the passed in vdev is currently "faulted". * Faulted, in this context, means that the vdev represents a * replacing or sparing vdev tree. */ static boolean_t vdev_draid_faulted(vdev_t *vd, uint64_t physical_offset) { if (vd->vdev_ops == &vdev_draid_spare_ops) { vd = vdev_draid_spare_get_child(vd, physical_offset); if (vd == NULL) return (B_FALSE); /* * After resolving the distributed spare to a leaf vdev * check the parent to determine if it's "faulted". */ vd = vd->vdev_parent; } return (vd->vdev_ops == &vdev_replacing_ops || vd->vdev_ops == &vdev_spare_ops); } /* * Determine if the dRAID block at the logical offset is degraded. * Used by sequential resilver. */ static boolean_t vdev_draid_group_degraded(vdev_t *vd, uint64_t offset) { vdev_draid_config_t *vdc = vd->vdev_tsd; ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); ASSERT3U(vdev_draid_get_astart(vd, offset), ==, offset); uint64_t groupstart, perm; uint64_t physical_offset = vdev_draid_logical_to_physical(vd, offset, &perm, &groupstart); uint8_t *base; uint64_t iter; vdev_draid_get_perm(vdc, perm, &base, &iter); for (uint64_t i = 0; i < vdc->vdc_groupwidth; i++) { uint64_t c = (groupstart + i) % vdc->vdc_ndisks; uint64_t cid = vdev_draid_permute_id(vdc, base, iter, c); vdev_t *cvd = vd->vdev_child[cid]; /* Group contains a faulted vdev. */ if (vdev_draid_faulted(cvd, physical_offset)) return (B_TRUE); /* * Always check groups with active distributed spares * because any vdev failure in the pool will affect them. */ if (vdev_draid_find_spare(cvd) != NULL) return (B_TRUE); } return (B_FALSE); } /* * Determine if the txg is missing. Used by healing resilver. */ static boolean_t vdev_draid_group_missing(vdev_t *vd, uint64_t offset, uint64_t txg, uint64_t size) { vdev_draid_config_t *vdc = vd->vdev_tsd; ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); ASSERT3U(vdev_draid_get_astart(vd, offset), ==, offset); uint64_t groupstart, perm; uint64_t physical_offset = vdev_draid_logical_to_physical(vd, offset, &perm, &groupstart); uint8_t *base; uint64_t iter; vdev_draid_get_perm(vdc, perm, &base, &iter); for (uint64_t i = 0; i < vdc->vdc_groupwidth; i++) { uint64_t c = (groupstart + i) % vdc->vdc_ndisks; uint64_t cid = vdev_draid_permute_id(vdc, base, iter, c); vdev_t *cvd = vd->vdev_child[cid]; /* Transaction group is known to be partially replicated. */ if (vdev_draid_partial(cvd, physical_offset, txg, size)) return (B_TRUE); /* * Always check groups with active distributed spares * because any vdev failure in the pool will affect them. */ if (vdev_draid_find_spare(cvd) != NULL) return (B_TRUE); } return (B_FALSE); } /* * Find the smallest child asize and largest sector size to calculate the * available capacity. Distributed spares are ignored since their capacity * is also based of the minimum child size in the top-level dRAID. */ static void vdev_draid_calculate_asize(vdev_t *vd, uint64_t *asizep, uint64_t *max_asizep, uint64_t *logical_ashiftp, uint64_t *physical_ashiftp) { uint64_t logical_ashift = 0, physical_ashift = 0; uint64_t asize = 0, max_asize = 0; ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); for (int c = 0; c < vd->vdev_children; c++) { vdev_t *cvd = vd->vdev_child[c]; if (cvd->vdev_ops == &vdev_draid_spare_ops) continue; asize = MIN(asize - 1, cvd->vdev_asize - 1) + 1; max_asize = MIN(max_asize - 1, cvd->vdev_max_asize - 1) + 1; logical_ashift = MAX(logical_ashift, cvd->vdev_ashift); physical_ashift = MAX(physical_ashift, cvd->vdev_physical_ashift); } *asizep = asize; *max_asizep = max_asize; *logical_ashiftp = logical_ashift; *physical_ashiftp = physical_ashift; } /* * Open spare vdevs. */ static boolean_t vdev_draid_open_spares(vdev_t *vd) { return (vd->vdev_ops == &vdev_draid_spare_ops || vd->vdev_ops == &vdev_replacing_ops || vd->vdev_ops == &vdev_spare_ops); } /* * Open all children, excluding spares. */ static boolean_t vdev_draid_open_children(vdev_t *vd) { return (!vdev_draid_open_spares(vd)); } /* * Open a top-level dRAID vdev. */ static int vdev_draid_open(vdev_t *vd, uint64_t *asize, uint64_t *max_asize, uint64_t *logical_ashift, uint64_t *physical_ashift) { vdev_draid_config_t *vdc = vd->vdev_tsd; uint64_t nparity = vdc->vdc_nparity; int open_errors = 0; if (nparity > VDEV_DRAID_MAXPARITY || vd->vdev_children < nparity + 1) { vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL; return (SET_ERROR(EINVAL)); } /* * First open the normal children then the distributed spares. This * ordering is important to ensure the distributed spares calculate * the correct psize in the event that the dRAID vdevs were expanded. */ vdev_open_children_subset(vd, vdev_draid_open_children); vdev_open_children_subset(vd, vdev_draid_open_spares); /* Verify enough of the children are available to continue. */ for (int c = 0; c < vd->vdev_children; c++) { if (vd->vdev_child[c]->vdev_open_error != 0) { if ((++open_errors) > nparity) { vd->vdev_stat.vs_aux = VDEV_AUX_NO_REPLICAS; return (SET_ERROR(ENXIO)); } } } /* * Allocatable capacity is the sum of the space on all children less * the number of distributed spares rounded down to last full row * and then to the last full group. An additional 32MB of scratch * space is reserved at the end of each child for use by the dRAID * expansion feature. */ uint64_t child_asize, child_max_asize; vdev_draid_calculate_asize(vd, &child_asize, &child_max_asize, logical_ashift, physical_ashift); /* * Should be unreachable since the minimum child size is 64MB, but * we want to make sure an underflow absolutely cannot occur here. */ if (child_asize < VDEV_DRAID_REFLOW_RESERVE || child_max_asize < VDEV_DRAID_REFLOW_RESERVE) { return (SET_ERROR(ENXIO)); } child_asize = ((child_asize - VDEV_DRAID_REFLOW_RESERVE) / VDEV_DRAID_ROWHEIGHT) * VDEV_DRAID_ROWHEIGHT; child_max_asize = ((child_max_asize - VDEV_DRAID_REFLOW_RESERVE) / VDEV_DRAID_ROWHEIGHT) * VDEV_DRAID_ROWHEIGHT; *asize = (((child_asize * vdc->vdc_ndisks) / vdc->vdc_groupsz) * vdc->vdc_groupsz); *max_asize = (((child_max_asize * vdc->vdc_ndisks) / vdc->vdc_groupsz) * vdc->vdc_groupsz); return (0); } /* * Close a top-level dRAID vdev. */ static void vdev_draid_close(vdev_t *vd) { for (int c = 0; c < vd->vdev_children; c++) { if (vd->vdev_child[c] != NULL) vdev_close(vd->vdev_child[c]); } } /* * Return the maximum asize for a rebuild zio in the provided range * given the following constraints. A dRAID chunks may not: * * - Exceed the maximum allowed block size (SPA_MAXBLOCKSIZE), or * - Span dRAID redundancy groups. */ static uint64_t vdev_draid_rebuild_asize(vdev_t *vd, uint64_t start, uint64_t asize, uint64_t max_segment) { vdev_draid_config_t *vdc = vd->vdev_tsd; ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); uint64_t ashift = vd->vdev_ashift; uint64_t ndata = vdc->vdc_ndata; uint64_t psize = MIN(P2ROUNDUP(max_segment * ndata, 1 << ashift), SPA_MAXBLOCKSIZE); ASSERT3U(vdev_draid_get_astart(vd, start), ==, start); ASSERT3U(asize % (vdc->vdc_groupwidth << ashift), ==, 0); /* Chunks must evenly span all data columns in the group. */ psize = (((psize >> ashift) / ndata) * ndata) << ashift; uint64_t chunk_size = MIN(asize, vdev_psize_to_asize(vd, psize)); /* Reduce the chunk size to the group space remaining. */ uint64_t group = vdev_draid_offset_to_group(vd, start); uint64_t left = vdev_draid_group_to_offset(vd, group + 1) - start; chunk_size = MIN(chunk_size, left); ASSERT3U(chunk_size % (vdc->vdc_groupwidth << ashift), ==, 0); ASSERT3U(vdev_draid_offset_to_group(vd, start), ==, vdev_draid_offset_to_group(vd, start + chunk_size - 1)); return (chunk_size); } /* * Align the start of the metaslab to the group width and slightly reduce * its size to a multiple of the group width. Since full stripe writes are * required by dRAID this space is unallocable. Furthermore, aligning the * metaslab start is important for vdev initialize and TRIM which both operate * on metaslab boundaries which vdev_xlate() expects to be aligned. */ static void vdev_draid_metaslab_init(vdev_t *vd, uint64_t *ms_start, uint64_t *ms_size) { vdev_draid_config_t *vdc = vd->vdev_tsd; ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); uint64_t sz = vdc->vdc_groupwidth << vd->vdev_ashift; uint64_t astart = vdev_draid_get_astart(vd, *ms_start); uint64_t asize = ((*ms_size - (astart - *ms_start)) / sz) * sz; *ms_start = astart; *ms_size = asize; ASSERT0(*ms_start % sz); ASSERT0(*ms_size % sz); } /* * Add virtual dRAID spares to the list of valid spares. In order to accomplish * this the existing array must be freed and reallocated with the additional * entries. */ int vdev_draid_spare_create(nvlist_t *nvroot, vdev_t *vd, uint64_t *ndraidp, uint64_t next_vdev_id) { uint64_t draid_nspares = 0; uint64_t ndraid = 0; int error; for (uint64_t i = 0; i < vd->vdev_children; i++) { vdev_t *cvd = vd->vdev_child[i]; if (cvd->vdev_ops == &vdev_draid_ops) { vdev_draid_config_t *vdc = cvd->vdev_tsd; draid_nspares += vdc->vdc_nspares; ndraid++; } } if (draid_nspares == 0) { *ndraidp = ndraid; return (0); } nvlist_t **old_spares, **new_spares; uint_t old_nspares; error = nvlist_lookup_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, &old_spares, &old_nspares); if (error) old_nspares = 0; /* Allocate memory and copy of the existing spares. */ new_spares = kmem_alloc(sizeof (nvlist_t *) * (draid_nspares + old_nspares), KM_SLEEP); for (uint_t i = 0; i < old_nspares; i++) new_spares[i] = fnvlist_dup(old_spares[i]); /* Add new distributed spares to ZPOOL_CONFIG_SPARES. */ uint64_t n = old_nspares; for (uint64_t vdev_id = 0; vdev_id < vd->vdev_children; vdev_id++) { vdev_t *cvd = vd->vdev_child[vdev_id]; char path[64]; if (cvd->vdev_ops != &vdev_draid_ops) continue; vdev_draid_config_t *vdc = cvd->vdev_tsd; uint64_t nspares = vdc->vdc_nspares; uint64_t nparity = vdc->vdc_nparity; for (uint64_t spare_id = 0; spare_id < nspares; spare_id++) { bzero(path, sizeof (path)); (void) snprintf(path, sizeof (path) - 1, "%s%llu-%llu-%llu", VDEV_TYPE_DRAID, (u_longlong_t)nparity, (u_longlong_t)next_vdev_id + vdev_id, (u_longlong_t)spare_id); nvlist_t *spare = fnvlist_alloc(); fnvlist_add_string(spare, ZPOOL_CONFIG_PATH, path); fnvlist_add_string(spare, ZPOOL_CONFIG_TYPE, VDEV_TYPE_DRAID_SPARE); fnvlist_add_uint64(spare, ZPOOL_CONFIG_TOP_GUID, cvd->vdev_guid); fnvlist_add_uint64(spare, ZPOOL_CONFIG_SPARE_ID, spare_id); fnvlist_add_uint64(spare, ZPOOL_CONFIG_IS_LOG, 0); fnvlist_add_uint64(spare, ZPOOL_CONFIG_IS_SPARE, 1); fnvlist_add_uint64(spare, ZPOOL_CONFIG_WHOLE_DISK, 1); fnvlist_add_uint64(spare, ZPOOL_CONFIG_ASHIFT, cvd->vdev_ashift); new_spares[n] = spare; n++; } } if (n > 0) { (void) nvlist_remove_all(nvroot, ZPOOL_CONFIG_SPARES); fnvlist_add_nvlist_array(nvroot, ZPOOL_CONFIG_SPARES, new_spares, n); } for (int i = 0; i < n; i++) nvlist_free(new_spares[i]); kmem_free(new_spares, sizeof (*new_spares) * n); *ndraidp = ndraid; return (0); } /* * Determine if any portion of the provided block resides on a child vdev * with a dirty DTL and therefore needs to be resilvered. */ static boolean_t vdev_draid_need_resilver(vdev_t *vd, const dva_t *dva, size_t psize, uint64_t phys_birth) { uint64_t offset = DVA_GET_OFFSET(dva); uint64_t asize = vdev_draid_asize(vd, psize); if (phys_birth == TXG_UNKNOWN) { /* * Sequential resilver. There is no meaningful phys_birth * for this block, we can only determine if block resides * in a degraded group in which case it must be resilvered. */ ASSERT3U(vdev_draid_offset_to_group(vd, offset), ==, vdev_draid_offset_to_group(vd, offset + asize - 1)); return (vdev_draid_group_degraded(vd, offset)); } else { /* * Healing resilver. TXGs not in DTL_PARTIAL are intact, * as are blocks in non-degraded groups. */ if (!vdev_dtl_contains(vd, DTL_PARTIAL, phys_birth, 1)) return (B_FALSE); if (vdev_draid_group_missing(vd, offset, phys_birth, 1)) return (B_TRUE); /* The block may span groups in which case check both. */ if (vdev_draid_offset_to_group(vd, offset) != vdev_draid_offset_to_group(vd, offset + asize - 1)) { if (vdev_draid_group_missing(vd, offset + asize, phys_birth, 1)) return (B_TRUE); } return (B_FALSE); } } static boolean_t vdev_draid_rebuilding(vdev_t *vd) { if (vd->vdev_ops->vdev_op_leaf && vd->vdev_rebuild_txg) return (B_TRUE); for (int i = 0; i < vd->vdev_children; i++) { if (vdev_draid_rebuilding(vd->vdev_child[i])) { return (B_TRUE); } } return (B_FALSE); } static void vdev_draid_io_verify(vdev_t *vd, raidz_row_t *rr, int col) { #ifdef ZFS_DEBUG range_seg64_t logical_rs, physical_rs, remain_rs; logical_rs.rs_start = rr->rr_offset; logical_rs.rs_end = logical_rs.rs_start + vdev_draid_asize(vd, rr->rr_size); raidz_col_t *rc = &rr->rr_col[col]; vdev_t *cvd = vd->vdev_child[rc->rc_devidx]; vdev_xlate(cvd, &logical_rs, &physical_rs, &remain_rs); ASSERT(vdev_xlate_is_empty(&remain_rs)); ASSERT3U(rc->rc_offset, ==, physical_rs.rs_start); ASSERT3U(rc->rc_offset, <, physical_rs.rs_end); ASSERT3U(rc->rc_offset + rc->rc_size, ==, physical_rs.rs_end); #endif } /* * For write operations: * 1. Generate the parity data * 2. Create child zio write operations to each column's vdev, for both * data and parity. A gang ABD is allocated by vdev_draid_map_alloc() * if a skip sector needs to be added to a column. */ static void vdev_draid_io_start_write(zio_t *zio, raidz_row_t *rr) { vdev_t *vd = zio->io_vd; raidz_map_t *rm = zio->io_vsd; vdev_raidz_generate_parity_row(rm, rr); for (int c = 0; c < rr->rr_cols; c++) { raidz_col_t *rc = &rr->rr_col[c]; /* * Empty columns are zero filled and included in the parity * calculation and therefore must be written. */ ASSERT3U(rc->rc_size, !=, 0); /* Verify physical to logical translation */ vdev_draid_io_verify(vd, rr, c); zio_nowait(zio_vdev_child_io(zio, NULL, vd->vdev_child[rc->rc_devidx], rc->rc_offset, rc->rc_abd, rc->rc_size, zio->io_type, zio->io_priority, 0, vdev_raidz_child_done, rc)); } } /* * For read operations: * 1. The vdev_draid_map_alloc() function will create a minimal raidz * mapping for the read based on the zio->io_flags. There are two * possible mappings either 1) a normal read, or 2) a scrub/resilver. * 2. Create the zio read operations. This will include all parity * columns and skip sectors for a scrub/resilver. */ static void vdev_draid_io_start_read(zio_t *zio, raidz_row_t *rr) { vdev_t *vd = zio->io_vd; /* Sequential rebuild must do IO at redundancy group boundary. */ IMPLY(zio->io_priority == ZIO_PRIORITY_REBUILD, rr->rr_nempty == 0); /* * Iterate over the columns in reverse order so that we hit the parity * last. Any errors along the way will force us to read the parity. * For scrub/resilver IOs which verify skip sectors, a gang ABD will * have been allocated to store them and rc->rc_size is increased. */ for (int c = rr->rr_cols - 1; c >= 0; c--) { raidz_col_t *rc = &rr->rr_col[c]; vdev_t *cvd = vd->vdev_child[rc->rc_devidx]; if (!vdev_draid_readable(cvd, rc->rc_offset)) { if (c >= rr->rr_firstdatacol) rr->rr_missingdata++; else rr->rr_missingparity++; rc->rc_error = SET_ERROR(ENXIO); rc->rc_tried = 1; rc->rc_skipped = 1; continue; } if (vdev_draid_missing(cvd, rc->rc_offset, zio->io_txg, 1)) { if (c >= rr->rr_firstdatacol) rr->rr_missingdata++; else rr->rr_missingparity++; rc->rc_error = SET_ERROR(ESTALE); rc->rc_skipped = 1; continue; } /* * Empty columns may be read during vdev_draid_io_done(). * Only skip them after the readable and missing checks * verify they are available. */ if (rc->rc_size == 0) { rc->rc_skipped = 1; continue; } if (zio->io_flags & ZIO_FLAG_RESILVER) { vdev_t *svd; /* * If this child is a distributed spare then the * offset might reside on the vdev being replaced. * In which case this data must be written to the * new device. Failure to do so would result in * checksum errors when the old device is detached * and the pool is scrubbed. */ if ((svd = vdev_draid_find_spare(cvd)) != NULL) { svd = vdev_draid_spare_get_child(svd, rc->rc_offset); if (svd && (svd->vdev_ops == &vdev_spare_ops || svd->vdev_ops == &vdev_replacing_ops)) { rc->rc_repair = 1; } } /* * Always issue a repair IO to this child when its * a spare or replacing vdev with an active rebuild. */ if ((cvd->vdev_ops == &vdev_spare_ops || cvd->vdev_ops == &vdev_replacing_ops) && vdev_draid_rebuilding(cvd)) { rc->rc_repair = 1; } } } /* * Either a parity or data column is missing this means a repair * may be attempted by vdev_draid_io_done(). Expand the raid map * to read in empty columns which are needed along with the parity * during reconstruction. */ if ((rr->rr_missingdata > 0 || rr->rr_missingparity > 0) && rr->rr_nempty > 0 && rr->rr_abd_empty == NULL) { vdev_draid_map_alloc_empty(zio, rr); } for (int c = rr->rr_cols - 1; c >= 0; c--) { raidz_col_t *rc = &rr->rr_col[c]; vdev_t *cvd = vd->vdev_child[rc->rc_devidx]; if (rc->rc_error || rc->rc_size == 0) continue; if (c >= rr->rr_firstdatacol || rr->rr_missingdata > 0 || (zio->io_flags & (ZIO_FLAG_SCRUB | ZIO_FLAG_RESILVER))) { zio_nowait(zio_vdev_child_io(zio, NULL, cvd, rc->rc_offset, rc->rc_abd, rc->rc_size, zio->io_type, zio->io_priority, 0, vdev_raidz_child_done, rc)); } } } /* * Start an IO operation to a dRAID vdev. */ static void vdev_draid_io_start(zio_t *zio) { vdev_t *vd __maybe_unused = zio->io_vd; raidz_map_t *rm; ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); ASSERT3U(zio->io_offset, ==, vdev_draid_get_astart(vd, zio->io_offset)); rm = vdev_draid_map_alloc(zio); if (zio->io_type == ZIO_TYPE_WRITE) { for (int i = 0; i < rm->rm_nrows; i++) { vdev_draid_io_start_write(zio, rm->rm_row[i]); } } else { ASSERT(zio->io_type == ZIO_TYPE_READ); for (int i = 0; i < rm->rm_nrows; i++) { vdev_draid_io_start_read(zio, rm->rm_row[i]); } } zio_execute(zio); } /* * Complete an IO operation on a dRAID vdev. The raidz logic can be applied * to dRAID since the layout is fully described by the raidz_map_t. */ static void vdev_draid_io_done(zio_t *zio) { vdev_raidz_io_done(zio); } static void vdev_draid_state_change(vdev_t *vd, int faulted, int degraded) { vdev_draid_config_t *vdc = vd->vdev_tsd; ASSERT(vd->vdev_ops == &vdev_draid_ops); if (faulted > vdc->vdc_nparity) vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN, VDEV_AUX_NO_REPLICAS); else if (degraded + faulted != 0) vdev_set_state(vd, B_FALSE, VDEV_STATE_DEGRADED, VDEV_AUX_NONE); else vdev_set_state(vd, B_FALSE, VDEV_STATE_HEALTHY, VDEV_AUX_NONE); } static void vdev_draid_xlate(vdev_t *cvd, const range_seg64_t *logical_rs, range_seg64_t *physical_rs, range_seg64_t *remain_rs) { vdev_t *raidvd = cvd->vdev_parent; ASSERT(raidvd->vdev_ops == &vdev_draid_ops); vdev_draid_config_t *vdc = raidvd->vdev_tsd; uint64_t ashift = raidvd->vdev_top->vdev_ashift; /* Make sure the offsets are block-aligned */ ASSERT0(logical_rs->rs_start % (1 << ashift)); ASSERT0(logical_rs->rs_end % (1 << ashift)); uint64_t logical_start = logical_rs->rs_start; uint64_t logical_end = logical_rs->rs_end; /* * Unaligned ranges must be skipped. All metaslabs are correctly * aligned so this should not happen, but this case is handled in * case it's needed by future callers. */ uint64_t astart = vdev_draid_get_astart(raidvd, logical_start); if (astart != logical_start) { physical_rs->rs_start = logical_start; physical_rs->rs_end = logical_start; remain_rs->rs_start = MIN(astart, logical_end); remain_rs->rs_end = logical_end; return; } /* * Unlike with mirrors and raidz a dRAID logical range can map * to multiple non-contiguous physical ranges. This is handled by * limiting the size of the logical range to a single group and * setting the remain argument such that it describes the remaining * unmapped logical range. This is stricter than absolutely * necessary but helps simplify the logic below. */ uint64_t group = vdev_draid_offset_to_group(raidvd, logical_start); uint64_t nextstart = vdev_draid_group_to_offset(raidvd, group + 1); if (logical_end > nextstart) logical_end = nextstart; /* Find the starting offset for each vdev in the group */ uint64_t perm, groupstart; uint64_t start = vdev_draid_logical_to_physical(raidvd, logical_start, &perm, &groupstart); uint64_t end = start; uint8_t *base; uint64_t iter, id; vdev_draid_get_perm(vdc, perm, &base, &iter); /* * Check if the passed child falls within the group. If it does * update the start and end to reflect the physical range. * Otherwise, leave them unmodified which will result in an empty * (zero-length) physical range being returned. */ for (uint64_t i = 0; i < vdc->vdc_groupwidth; i++) { uint64_t c = (groupstart + i) % vdc->vdc_ndisks; if (c == 0 && i != 0) { /* the group wrapped, increment the start */ start += VDEV_DRAID_ROWHEIGHT; end = start; } id = vdev_draid_permute_id(vdc, base, iter, c); if (id == cvd->vdev_id) { uint64_t b_size = (logical_end >> ashift) - (logical_start >> ashift); ASSERT3U(b_size, >, 0); end = start + ((((b_size - 1) / vdc->vdc_groupwidth) + 1) << ashift); break; } } physical_rs->rs_start = start; physical_rs->rs_end = end; /* * Only top-level vdevs are allowed to set remain_rs because * when .vdev_op_xlate() is called for their children the full * logical range is not provided by vdev_xlate(). */ remain_rs->rs_start = logical_end; remain_rs->rs_end = logical_rs->rs_end; ASSERT3U(physical_rs->rs_start, <=, logical_start); ASSERT3U(physical_rs->rs_end - physical_rs->rs_start, <=, logical_end - logical_start); } /* * Add dRAID specific fields to the config nvlist. */ static void vdev_draid_config_generate(vdev_t *vd, nvlist_t *nv) { ASSERT3P(vd->vdev_ops, ==, &vdev_draid_ops); vdev_draid_config_t *vdc = vd->vdev_tsd; fnvlist_add_uint64(nv, ZPOOL_CONFIG_NPARITY, vdc->vdc_nparity); fnvlist_add_uint64(nv, ZPOOL_CONFIG_DRAID_NDATA, vdc->vdc_ndata); fnvlist_add_uint64(nv, ZPOOL_CONFIG_DRAID_NSPARES, vdc->vdc_nspares); fnvlist_add_uint64(nv, ZPOOL_CONFIG_DRAID_NGROUPS, vdc->vdc_ngroups); } /* * Initialize private dRAID specific fields from the nvlist. */ static int vdev_draid_init(spa_t *spa, nvlist_t *nv, void **tsd) { uint64_t ndata, nparity, nspares, ngroups; int error; if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_DRAID_NDATA, &ndata)) return (SET_ERROR(EINVAL)); if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_NPARITY, &nparity) || nparity == 0 || nparity > VDEV_DRAID_MAXPARITY) { return (SET_ERROR(EINVAL)); } uint_t children; nvlist_t **child; if (nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN, &child, &children) != 0 || children == 0 || children > VDEV_DRAID_MAX_CHILDREN) { return (SET_ERROR(EINVAL)); } if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_DRAID_NSPARES, &nspares) || nspares > 100 || nspares > (children - (ndata + nparity))) { return (SET_ERROR(EINVAL)); } if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_DRAID_NGROUPS, &ngroups) || ngroups == 0 || ngroups > VDEV_DRAID_MAX_CHILDREN) { return (SET_ERROR(EINVAL)); } /* * Validate the minimum number of children exist per group for the * specified parity level (draid1 >= 2, draid2 >= 3, draid3 >= 4). */ if (children < (ndata + nparity + nspares)) return (SET_ERROR(EINVAL)); /* * Create the dRAID configuration using the pool nvlist configuration * and the fixed mapping for the correct number of children. */ vdev_draid_config_t *vdc; const draid_map_t *map; error = vdev_draid_lookup_map(children, &map); if (error) return (SET_ERROR(EINVAL)); vdc = kmem_zalloc(sizeof (*vdc), KM_SLEEP); vdc->vdc_ndata = ndata; vdc->vdc_nparity = nparity; vdc->vdc_nspares = nspares; vdc->vdc_children = children; vdc->vdc_ngroups = ngroups; vdc->vdc_nperms = map->dm_nperms; error = vdev_draid_generate_perms(map, &vdc->vdc_perms); if (error) { kmem_free(vdc, sizeof (*vdc)); return (SET_ERROR(EINVAL)); } /* * Derived constants. */ vdc->vdc_groupwidth = vdc->vdc_ndata + vdc->vdc_nparity; vdc->vdc_ndisks = vdc->vdc_children - vdc->vdc_nspares; vdc->vdc_groupsz = vdc->vdc_groupwidth * VDEV_DRAID_ROWHEIGHT; vdc->vdc_devslicesz = (vdc->vdc_groupsz * vdc->vdc_ngroups) / vdc->vdc_ndisks; ASSERT3U(vdc->vdc_groupwidth, >=, 2); ASSERT3U(vdc->vdc_groupwidth, <=, vdc->vdc_ndisks); ASSERT3U(vdc->vdc_groupsz, >=, 2 * VDEV_DRAID_ROWHEIGHT); ASSERT3U(vdc->vdc_devslicesz, >=, VDEV_DRAID_ROWHEIGHT); ASSERT3U(vdc->vdc_devslicesz % VDEV_DRAID_ROWHEIGHT, ==, 0); ASSERT3U((vdc->vdc_groupwidth * vdc->vdc_ngroups) % vdc->vdc_ndisks, ==, 0); *tsd = vdc; return (0); } static void vdev_draid_fini(vdev_t *vd) { vdev_draid_config_t *vdc = vd->vdev_tsd; vmem_free(vdc->vdc_perms, sizeof (uint8_t) * vdc->vdc_children * vdc->vdc_nperms); kmem_free(vdc, sizeof (*vdc)); } static uint64_t vdev_draid_nparity(vdev_t *vd) { vdev_draid_config_t *vdc = vd->vdev_tsd; return (vdc->vdc_nparity); } static uint64_t vdev_draid_ndisks(vdev_t *vd) { vdev_draid_config_t *vdc = vd->vdev_tsd; return (vdc->vdc_ndisks); } vdev_ops_t vdev_draid_ops = { .vdev_op_init = vdev_draid_init, .vdev_op_fini = vdev_draid_fini, .vdev_op_open = vdev_draid_open, .vdev_op_close = vdev_draid_close, .vdev_op_asize = vdev_draid_asize, .vdev_op_min_asize = vdev_draid_min_asize, .vdev_op_min_alloc = vdev_draid_min_alloc, .vdev_op_io_start = vdev_draid_io_start, .vdev_op_io_done = vdev_draid_io_done, .vdev_op_state_change = vdev_draid_state_change, .vdev_op_need_resilver = vdev_draid_need_resilver, .vdev_op_hold = NULL, .vdev_op_rele = NULL, .vdev_op_remap = NULL, .vdev_op_xlate = vdev_draid_xlate, .vdev_op_rebuild_asize = vdev_draid_rebuild_asize, .vdev_op_metaslab_init = vdev_draid_metaslab_init, .vdev_op_config_generate = vdev_draid_config_generate, .vdev_op_nparity = vdev_draid_nparity, .vdev_op_ndisks = vdev_draid_ndisks, .vdev_op_type = VDEV_TYPE_DRAID, .vdev_op_leaf = B_FALSE, }; /* * A dRAID distributed spare is a virtual leaf vdev which is included in the * parent dRAID configuration. The last N columns of the dRAID permutation * table are used to determine on which dRAID children a specific offset * should be written. These spare leaf vdevs can only be used to replace * faulted children in the same dRAID configuration. */ /* * Distributed spare state. All fields are set when the distributed spare is * first opened and are immutable. */ typedef struct { vdev_t *vds_draid_vdev; /* top-level parent dRAID vdev */ uint64_t vds_top_guid; /* top-level parent dRAID guid */ uint64_t vds_spare_id; /* spare id (0 - vdc->vdc_nspares-1) */ } vdev_draid_spare_t; /* * Returns the parent dRAID vdev to which the distributed spare belongs. * This may be safely called even when the vdev is not open. */ vdev_t * vdev_draid_spare_get_parent(vdev_t *vd) { vdev_draid_spare_t *vds = vd->vdev_tsd; ASSERT3P(vd->vdev_ops, ==, &vdev_draid_spare_ops); if (vds->vds_draid_vdev != NULL) return (vds->vds_draid_vdev); return (vdev_lookup_by_guid(vd->vdev_spa->spa_root_vdev, vds->vds_top_guid)); } /* * A dRAID space is active when it's the child of a vdev using the * vdev_spare_ops, vdev_replacing_ops or vdev_draid_ops. */ static boolean_t vdev_draid_spare_is_active(vdev_t *vd) { vdev_t *pvd = vd->vdev_parent; if (pvd != NULL && (pvd->vdev_ops == &vdev_spare_ops || pvd->vdev_ops == &vdev_replacing_ops || pvd->vdev_ops == &vdev_draid_ops)) { return (B_TRUE); } else { return (B_FALSE); } } /* * Given a dRAID distribute spare vdev, returns the physical child vdev * on which the provided offset resides. This may involve recursing through * multiple layers of distributed spares. Note that offset is relative to * this vdev. */ vdev_t * vdev_draid_spare_get_child(vdev_t *vd, uint64_t physical_offset) { vdev_draid_spare_t *vds = vd->vdev_tsd; ASSERT3P(vd->vdev_ops, ==, &vdev_draid_spare_ops); /* The vdev is closed */ if (vds->vds_draid_vdev == NULL) return (NULL); vdev_t *tvd = vds->vds_draid_vdev; vdev_draid_config_t *vdc = tvd->vdev_tsd; ASSERT3P(tvd->vdev_ops, ==, &vdev_draid_ops); ASSERT3U(vds->vds_spare_id, <, vdc->vdc_nspares); uint8_t *base; uint64_t iter; uint64_t perm = physical_offset / vdc->vdc_devslicesz; vdev_draid_get_perm(vdc, perm, &base, &iter); uint64_t cid = vdev_draid_permute_id(vdc, base, iter, (tvd->vdev_children - 1) - vds->vds_spare_id); vdev_t *cvd = tvd->vdev_child[cid]; if (cvd->vdev_ops == &vdev_draid_spare_ops) return (vdev_draid_spare_get_child(cvd, physical_offset)); return (cvd); } /* ARGSUSED */ static void vdev_draid_spare_close(vdev_t *vd) { vdev_draid_spare_t *vds = vd->vdev_tsd; vds->vds_draid_vdev = NULL; } /* * Opening a dRAID spare device is done by looking up the associated dRAID * top-level vdev guid from the spare configuration. */ static int vdev_draid_spare_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize, uint64_t *logical_ashift, uint64_t *physical_ashift) { vdev_draid_spare_t *vds = vd->vdev_tsd; vdev_t *rvd = vd->vdev_spa->spa_root_vdev; uint64_t asize, max_asize; vdev_t *tvd = vdev_lookup_by_guid(rvd, vds->vds_top_guid); if (tvd == NULL) { /* * When spa_vdev_add() is labeling new spares the * associated dRAID is not attached to the root vdev * nor does this spare have a parent. Simulate a valid * device in order to allow the label to be initialized * and the distributed spare added to the configuration. */ if (vd->vdev_parent == NULL) { *psize = *max_psize = SPA_MINDEVSIZE; *logical_ashift = *physical_ashift = ASHIFT_MIN; return (0); } return (SET_ERROR(EINVAL)); } vdev_draid_config_t *vdc = tvd->vdev_tsd; if (tvd->vdev_ops != &vdev_draid_ops || vdc == NULL) return (SET_ERROR(EINVAL)); if (vds->vds_spare_id >= vdc->vdc_nspares) return (SET_ERROR(EINVAL)); /* * Neither tvd->vdev_asize or tvd->vdev_max_asize can be used here * because the caller may be vdev_draid_open() in which case the * values are stale as they haven't yet been updated by vdev_open(). * To avoid this always recalculate the dRAID asize and max_asize. */ vdev_draid_calculate_asize(tvd, &asize, &max_asize, logical_ashift, physical_ashift); *psize = asize + VDEV_LABEL_START_SIZE + VDEV_LABEL_END_SIZE; *max_psize = max_asize + VDEV_LABEL_START_SIZE + VDEV_LABEL_END_SIZE; vds->vds_draid_vdev = tvd; return (0); } /* * Completed distributed spare IO. Store the result in the parent zio * as if it had performed the operation itself. Only the first error is * preserved if there are multiple errors. */ static void vdev_draid_spare_child_done(zio_t *zio) { zio_t *pio = zio->io_private; /* * IOs are issued to non-writable vdevs in order to keep their * DTLs accurate. However, we don't want to propagate the * error in to the distributed spare's DTL. When resilvering * vdev_draid_need_resilver() will consult the relevant DTL * to determine if the data is missing and must be repaired. */ if (!vdev_writeable(zio->io_vd)) return; if (pio->io_error == 0) pio->io_error = zio->io_error; } /* * Returns a valid label nvlist for the distributed spare vdev. This is * used to bypass the IO pipeline to avoid the complexity of constructing * a complete label with valid checksum to return when read. */ nvlist_t * vdev_draid_read_config_spare(vdev_t *vd) { spa_t *spa = vd->vdev_spa; spa_aux_vdev_t *sav = &spa->spa_spares; uint64_t guid = vd->vdev_guid; nvlist_t *nv = fnvlist_alloc(); fnvlist_add_uint64(nv, ZPOOL_CONFIG_IS_SPARE, 1); fnvlist_add_uint64(nv, ZPOOL_CONFIG_CREATE_TXG, vd->vdev_crtxg); fnvlist_add_uint64(nv, ZPOOL_CONFIG_VERSION, spa_version(spa)); fnvlist_add_string(nv, ZPOOL_CONFIG_POOL_NAME, spa_name(spa)); fnvlist_add_uint64(nv, ZPOOL_CONFIG_POOL_GUID, spa_guid(spa)); fnvlist_add_uint64(nv, ZPOOL_CONFIG_POOL_TXG, spa->spa_config_txg); fnvlist_add_uint64(nv, ZPOOL_CONFIG_TOP_GUID, vd->vdev_top->vdev_guid); fnvlist_add_uint64(nv, ZPOOL_CONFIG_POOL_STATE, vdev_draid_spare_is_active(vd) ? POOL_STATE_ACTIVE : POOL_STATE_SPARE); /* Set the vdev guid based on the vdev list in sav_count. */ for (int i = 0; i < sav->sav_count; i++) { if (sav->sav_vdevs[i]->vdev_ops == &vdev_draid_spare_ops && strcmp(sav->sav_vdevs[i]->vdev_path, vd->vdev_path) == 0) { guid = sav->sav_vdevs[i]->vdev_guid; break; } } fnvlist_add_uint64(nv, ZPOOL_CONFIG_GUID, guid); return (nv); } /* * Handle any ioctl requested of the distributed spare. Only flushes * are supported in which case all children must be flushed. */ static int vdev_draid_spare_ioctl(zio_t *zio) { vdev_t *vd = zio->io_vd; int error = 0; if (zio->io_cmd == DKIOCFLUSHWRITECACHE) { for (int c = 0; c < vd->vdev_children; c++) { zio_nowait(zio_vdev_child_io(zio, NULL, vd->vdev_child[c], zio->io_offset, zio->io_abd, zio->io_size, zio->io_type, zio->io_priority, 0, vdev_draid_spare_child_done, zio)); } } else { error = SET_ERROR(ENOTSUP); } return (error); } /* * Initiate an IO to the distributed spare. For normal IOs this entails using * the zio->io_offset and permutation table to calculate which child dRAID vdev * is responsible for the data. Then passing along the zio to that child to * perform the actual IO. The label ranges are not stored on disk and require * some special handling which is described below. */ static void vdev_draid_spare_io_start(zio_t *zio) { vdev_t *cvd = NULL, *vd = zio->io_vd; vdev_draid_spare_t *vds = vd->vdev_tsd; uint64_t offset = zio->io_offset - VDEV_LABEL_START_SIZE; /* * If the vdev is closed, it's likely in the REMOVED or FAULTED state. * Nothing to be done here but return failure. */ if (vds == NULL) { zio->io_error = ENXIO; zio_interrupt(zio); return; } switch (zio->io_type) { case ZIO_TYPE_IOCTL: zio->io_error = vdev_draid_spare_ioctl(zio); break; case ZIO_TYPE_WRITE: if (VDEV_OFFSET_IS_LABEL(vd, zio->io_offset)) { /* * Accept probe IOs and config writers to simulate the * existence of an on disk label. vdev_label_sync(), * vdev_uberblock_sync() and vdev_copy_uberblocks() * skip the distributed spares. This only leaves * vdev_label_init() which is allowed to succeed to * avoid adding special cases the function. */ if (zio->io_flags & ZIO_FLAG_PROBE || zio->io_flags & ZIO_FLAG_CONFIG_WRITER) { zio->io_error = 0; } else { zio->io_error = SET_ERROR(EIO); } } else { cvd = vdev_draid_spare_get_child(vd, offset); if (cvd == NULL) { zio->io_error = SET_ERROR(ENXIO); } else { zio_nowait(zio_vdev_child_io(zio, NULL, cvd, offset, zio->io_abd, zio->io_size, zio->io_type, zio->io_priority, 0, vdev_draid_spare_child_done, zio)); } } break; case ZIO_TYPE_READ: if (VDEV_OFFSET_IS_LABEL(vd, zio->io_offset)) { /* * Accept probe IOs to simulate the existence of a * label. vdev_label_read_config() bypasses the * pipeline to read the label configuration and * vdev_uberblock_load() skips distributed spares * when attempting to locate the best uberblock. */ if (zio->io_flags & ZIO_FLAG_PROBE) { zio->io_error = 0; } else { zio->io_error = SET_ERROR(EIO); } } else { cvd = vdev_draid_spare_get_child(vd, offset); if (cvd == NULL || !vdev_readable(cvd)) { zio->io_error = SET_ERROR(ENXIO); } else { zio_nowait(zio_vdev_child_io(zio, NULL, cvd, offset, zio->io_abd, zio->io_size, zio->io_type, zio->io_priority, 0, vdev_draid_spare_child_done, zio)); } } break; case ZIO_TYPE_TRIM: /* The vdev label ranges are never trimmed */ ASSERT0(VDEV_OFFSET_IS_LABEL(vd, zio->io_offset)); cvd = vdev_draid_spare_get_child(vd, offset); if (cvd == NULL || !cvd->vdev_has_trim) { zio->io_error = SET_ERROR(ENXIO); } else { zio_nowait(zio_vdev_child_io(zio, NULL, cvd, offset, zio->io_abd, zio->io_size, zio->io_type, zio->io_priority, 0, vdev_draid_spare_child_done, zio)); } break; default: zio->io_error = SET_ERROR(ENOTSUP); break; } zio_execute(zio); } /* ARGSUSED */ static void vdev_draid_spare_io_done(zio_t *zio) { } /* * Lookup the full spare config in spa->spa_spares.sav_config and * return the top_guid and spare_id for the named spare. */ static int vdev_draid_spare_lookup(spa_t *spa, nvlist_t *nv, uint64_t *top_guidp, uint64_t *spare_idp) { nvlist_t **spares; uint_t nspares; int error; if ((spa->spa_spares.sav_config == NULL) || (nvlist_lookup_nvlist_array(spa->spa_spares.sav_config, ZPOOL_CONFIG_SPARES, &spares, &nspares) != 0)) { return (SET_ERROR(ENOENT)); } char *spare_name; error = nvlist_lookup_string(nv, ZPOOL_CONFIG_PATH, &spare_name); if (error != 0) return (SET_ERROR(EINVAL)); for (int i = 0; i < nspares; i++) { nvlist_t *spare = spares[i]; uint64_t top_guid, spare_id; char *type, *path; /* Skip non-distributed spares */ error = nvlist_lookup_string(spare, ZPOOL_CONFIG_TYPE, &type); if (error != 0 || strcmp(type, VDEV_TYPE_DRAID_SPARE) != 0) continue; /* Skip spares with the wrong name */ error = nvlist_lookup_string(spare, ZPOOL_CONFIG_PATH, &path); if (error != 0 || strcmp(path, spare_name) != 0) continue; /* Found the matching spare */ error = nvlist_lookup_uint64(spare, ZPOOL_CONFIG_TOP_GUID, &top_guid); if (error == 0) { error = nvlist_lookup_uint64(spare, ZPOOL_CONFIG_SPARE_ID, &spare_id); } if (error != 0) { return (SET_ERROR(EINVAL)); } else { *top_guidp = top_guid; *spare_idp = spare_id; return (0); } } return (SET_ERROR(ENOENT)); } /* * Initialize private dRAID spare specific fields from the nvlist. */ static int vdev_draid_spare_init(spa_t *spa, nvlist_t *nv, void **tsd) { vdev_draid_spare_t *vds; uint64_t top_guid = 0; uint64_t spare_id; /* * In the normal case check the list of spares stored in the spa * to lookup the top_guid and spare_id for provided spare config. * When creating a new pool or adding vdevs the spare list is not * yet populated and the values are provided in the passed config. */ if (vdev_draid_spare_lookup(spa, nv, &top_guid, &spare_id) != 0) { if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_TOP_GUID, &top_guid) != 0) return (SET_ERROR(EINVAL)); if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_SPARE_ID, &spare_id) != 0) return (SET_ERROR(EINVAL)); } vds = kmem_alloc(sizeof (vdev_draid_spare_t), KM_SLEEP); vds->vds_draid_vdev = NULL; vds->vds_top_guid = top_guid; vds->vds_spare_id = spare_id; *tsd = vds; return (0); } static void vdev_draid_spare_fini(vdev_t *vd) { kmem_free(vd->vdev_tsd, sizeof (vdev_draid_spare_t)); } static void vdev_draid_spare_config_generate(vdev_t *vd, nvlist_t *nv) { vdev_draid_spare_t *vds = vd->vdev_tsd; ASSERT3P(vd->vdev_ops, ==, &vdev_draid_spare_ops); fnvlist_add_uint64(nv, ZPOOL_CONFIG_TOP_GUID, vds->vds_top_guid); fnvlist_add_uint64(nv, ZPOOL_CONFIG_SPARE_ID, vds->vds_spare_id); } vdev_ops_t vdev_draid_spare_ops = { .vdev_op_init = vdev_draid_spare_init, .vdev_op_fini = vdev_draid_spare_fini, .vdev_op_open = vdev_draid_spare_open, .vdev_op_close = vdev_draid_spare_close, .vdev_op_asize = vdev_default_asize, .vdev_op_min_asize = vdev_default_min_asize, .vdev_op_min_alloc = NULL, .vdev_op_io_start = vdev_draid_spare_io_start, .vdev_op_io_done = vdev_draid_spare_io_done, .vdev_op_state_change = NULL, .vdev_op_need_resilver = NULL, .vdev_op_hold = NULL, .vdev_op_rele = NULL, .vdev_op_remap = NULL, .vdev_op_xlate = vdev_default_xlate, .vdev_op_rebuild_asize = NULL, .vdev_op_metaslab_init = NULL, .vdev_op_config_generate = vdev_draid_spare_config_generate, .vdev_op_nparity = NULL, .vdev_op_ndisks = NULL, .vdev_op_type = VDEV_TYPE_DRAID_SPARE, .vdev_op_leaf = B_TRUE, }; diff --git a/module/zfs/vdev_indirect.c b/module/zfs/vdev_indirect.c index 07d1c922a50c..b26d0993711a 100644 --- a/module/zfs/vdev_indirect.c +++ b/module/zfs/vdev_indirect.c @@ -1,1911 +1,1911 @@ /* * CDDL HEADER START * * This file and its contents are supplied under the terms of the * Common Development and Distribution License ("CDDL"), version 1.0. * You may only use this file in accordance with the terms of version * 1.0 of the CDDL. * * A full copy of the text of the CDDL should have accompanied this * source. A copy of the CDDL is also available via the Internet at * http://www.illumos.org/license/CDDL. * * CDDL HEADER END */ /* * Copyright (c) 2014, 2017 by Delphix. All rights reserved. * Copyright (c) 2019, loli10K . All rights reserved. * Copyright (c) 2014, 2020 by Delphix. All rights reserved. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * An indirect vdev corresponds to a vdev that has been removed. Since * we cannot rewrite block pointers of snapshots, etc., we keep a * mapping from old location on the removed device to the new location * on another device in the pool and use this mapping whenever we need * to access the DVA. Unfortunately, this mapping did not respect * logical block boundaries when it was first created, and so a DVA on * this indirect vdev may be "split" into multiple sections that each * map to a different location. As a consequence, not all DVAs can be * translated to an equivalent new DVA. Instead we must provide a * "vdev_remap" operation that executes a callback on each contiguous * segment of the new location. This function is used in multiple ways: * * - i/os to this vdev use the callback to determine where the * data is now located, and issue child i/os for each segment's new * location. * * - frees and claims to this vdev use the callback to free or claim * each mapped segment. (Note that we don't actually need to claim * log blocks on indirect vdevs, because we don't allocate to * removing vdevs. However, zdb uses zio_claim() for its leak * detection.) */ /* * "Big theory statement" for how we mark blocks obsolete. * * When a block on an indirect vdev is freed or remapped, a section of * that vdev's mapping may no longer be referenced (aka "obsolete"). We * keep track of how much of each mapping entry is obsolete. When * an entry becomes completely obsolete, we can remove it, thus reducing * the memory used by the mapping. The complete picture of obsolescence * is given by the following data structures, described below: * - the entry-specific obsolete count * - the vdev-specific obsolete spacemap * - the pool-specific obsolete bpobj * * == On disk data structures used == * * We track the obsolete space for the pool using several objects. Each * of these objects is created on demand and freed when no longer * needed, and is assumed to be empty if it does not exist. * SPA_FEATURE_OBSOLETE_COUNTS includes the count of these objects. * * - Each vic_mapping_object (associated with an indirect vdev) can * have a vimp_counts_object. This is an array of uint32_t's * with the same number of entries as the vic_mapping_object. When * the mapping is condensed, entries from the vic_obsolete_sm_object * (see below) are folded into the counts. Therefore, each * obsolete_counts entry tells us the number of bytes in the * corresponding mapping entry that were not referenced when the * mapping was last condensed. * * - Each indirect or removing vdev can have a vic_obsolete_sm_object. * This is a space map containing an alloc entry for every DVA that * has been obsoleted since the last time this indirect vdev was * condensed. We use this object in order to improve performance * when marking a DVA as obsolete. Instead of modifying an arbitrary * offset of the vimp_counts_object, we only need to append an entry * to the end of this object. When a DVA becomes obsolete, it is * added to the obsolete space map. This happens when the DVA is * freed, remapped and not referenced by a snapshot, or the last * snapshot referencing it is destroyed. * * - Each dataset can have a ds_remap_deadlist object. This is a * deadlist object containing all blocks that were remapped in this * dataset but referenced in a previous snapshot. Blocks can *only* * appear on this list if they were remapped (dsl_dataset_block_remapped); * blocks that were killed in a head dataset are put on the normal * ds_deadlist and marked obsolete when they are freed. * * - The pool can have a dp_obsolete_bpobj. This is a list of blocks * in the pool that need to be marked obsolete. When a snapshot is * destroyed, we move some of the ds_remap_deadlist to the obsolete * bpobj (see dsl_destroy_snapshot_handle_remaps()). We then * asynchronously process the obsolete bpobj, moving its entries to * the specific vdevs' obsolete space maps. * * == Summary of how we mark blocks as obsolete == * * - When freeing a block: if any DVA is on an indirect vdev, append to * vic_obsolete_sm_object. * - When remapping a block, add dva to ds_remap_deadlist (if prev snap * references; otherwise append to vic_obsolete_sm_object). * - When freeing a snapshot: move parts of ds_remap_deadlist to * dp_obsolete_bpobj (same algorithm as ds_deadlist). * - When syncing the spa: process dp_obsolete_bpobj, moving ranges to * individual vdev's vic_obsolete_sm_object. */ /* * "Big theory statement" for how we condense indirect vdevs. * * Condensing an indirect vdev's mapping is the process of determining * the precise counts of obsolete space for each mapping entry (by * integrating the obsolete spacemap into the obsolete counts) and * writing out a new mapping that contains only referenced entries. * * We condense a vdev when we expect the mapping to shrink (see * vdev_indirect_should_condense()), but only perform one condense at a * time to limit the memory usage. In addition, we use a separate * open-context thread (spa_condense_indirect_thread) to incrementally * create the new mapping object in a way that minimizes the impact on * the rest of the system. * * == Generating a new mapping == * * To generate a new mapping, we follow these steps: * * 1. Save the old obsolete space map and create a new mapping object * (see spa_condense_indirect_start_sync()). This initializes the * spa_condensing_indirect_phys with the "previous obsolete space map", * which is now read only. Newly obsolete DVAs will be added to a * new (initially empty) obsolete space map, and will not be * considered as part of this condense operation. * * 2. Construct in memory the precise counts of obsolete space for each * mapping entry, by incorporating the obsolete space map into the * counts. (See vdev_indirect_mapping_load_obsolete_{counts,spacemap}().) * * 3. Iterate through each mapping entry, writing to the new mapping any * entries that are not completely obsolete (i.e. which don't have * obsolete count == mapping length). (See * spa_condense_indirect_generate_new_mapping().) * * 4. Destroy the old mapping object and switch over to the new one * (spa_condense_indirect_complete_sync). * * == Restarting from failure == * * To restart the condense when we import/open the pool, we must start * at the 2nd step above: reconstruct the precise counts in memory, * based on the space map + counts. Then in the 3rd step, we start * iterating where we left off: at vimp_max_offset of the new mapping * object. */ int zfs_condense_indirect_vdevs_enable = B_TRUE; /* * Condense if at least this percent of the bytes in the mapping is * obsolete. With the default of 25%, the amount of space mapped * will be reduced to 1% of its original size after at most 16 * condenses. Higher values will condense less often (causing less * i/o); lower values will reduce the mapping size more quickly. */ int zfs_indirect_condense_obsolete_pct = 25; /* * Condense if the obsolete space map takes up more than this amount of * space on disk (logically). This limits the amount of disk space * consumed by the obsolete space map; the default of 1GB is small enough * that we typically don't mind "wasting" it. */ unsigned long zfs_condense_max_obsolete_bytes = 1024 * 1024 * 1024; /* * Don't bother condensing if the mapping uses less than this amount of * memory. The default of 128KB is considered a "trivial" amount of * memory and not worth reducing. */ unsigned long zfs_condense_min_mapping_bytes = 128 * 1024; /* * This is used by the test suite so that it can ensure that certain * actions happen while in the middle of a condense (which might otherwise * complete too quickly). If used to reduce the performance impact of * condensing in production, a maximum value of 1 should be sufficient. */ int zfs_condense_indirect_commit_entry_delay_ms = 0; /* * If an indirect split block contains more than this many possible unique * combinations when being reconstructed, consider it too computationally * expensive to check them all. Instead, try at most 100 randomly-selected * combinations each time the block is accessed. This allows all segment * copies to participate fairly in the reconstruction when all combinations * cannot be checked and prevents repeated use of one bad copy. */ int zfs_reconstruct_indirect_combinations_max = 4096; /* * Enable to simulate damaged segments and validate reconstruction. This * is intentionally not exposed as a module parameter. */ unsigned long zfs_reconstruct_indirect_damage_fraction = 0; /* * The indirect_child_t represents the vdev that we will read from, when we * need to read all copies of the data (e.g. for scrub or reconstruction). * For plain (non-mirror) top-level vdevs (i.e. is_vdev is not a mirror), * ic_vdev is the same as is_vdev. However, for mirror top-level vdevs, * ic_vdev is a child of the mirror. */ typedef struct indirect_child { abd_t *ic_data; vdev_t *ic_vdev; /* * ic_duplicate is NULL when the ic_data contents are unique, when it * is determined to be a duplicate it references the primary child. */ struct indirect_child *ic_duplicate; list_node_t ic_node; /* node on is_unique_child */ int ic_error; /* set when a child does not contain the data */ } indirect_child_t; /* * The indirect_split_t represents one mapped segment of an i/o to the * indirect vdev. For non-split (contiguously-mapped) blocks, there will be * only one indirect_split_t, with is_split_offset==0 and is_size==io_size. * For split blocks, there will be several of these. */ typedef struct indirect_split { list_node_t is_node; /* link on iv_splits */ /* * is_split_offset is the offset into the i/o. * This is the sum of the previous splits' is_size's. */ uint64_t is_split_offset; vdev_t *is_vdev; /* top-level vdev */ uint64_t is_target_offset; /* offset on is_vdev */ uint64_t is_size; int is_children; /* number of entries in is_child[] */ int is_unique_children; /* number of entries in is_unique_child */ list_t is_unique_child; /* * is_good_child is the child that we are currently using to * attempt reconstruction. */ indirect_child_t *is_good_child; indirect_child_t is_child[1]; /* variable-length */ } indirect_split_t; /* * The indirect_vsd_t is associated with each i/o to the indirect vdev. * It is the "Vdev-Specific Data" in the zio_t's io_vsd. */ typedef struct indirect_vsd { boolean_t iv_split_block; boolean_t iv_reconstruct; uint64_t iv_unique_combinations; uint64_t iv_attempts; uint64_t iv_attempts_max; list_t iv_splits; /* list of indirect_split_t's */ } indirect_vsd_t; static void vdev_indirect_map_free(zio_t *zio) { indirect_vsd_t *iv = zio->io_vsd; indirect_split_t *is; while ((is = list_head(&iv->iv_splits)) != NULL) { for (int c = 0; c < is->is_children; c++) { indirect_child_t *ic = &is->is_child[c]; if (ic->ic_data != NULL) abd_free(ic->ic_data); } list_remove(&iv->iv_splits, is); indirect_child_t *ic; while ((ic = list_head(&is->is_unique_child)) != NULL) list_remove(&is->is_unique_child, ic); list_destroy(&is->is_unique_child); kmem_free(is, offsetof(indirect_split_t, is_child[is->is_children])); } kmem_free(iv, sizeof (*iv)); } static const zio_vsd_ops_t vdev_indirect_vsd_ops = { .vsd_free = vdev_indirect_map_free, .vsd_cksum_report = zio_vsd_default_cksum_report }; /* * Mark the given offset and size as being obsolete. */ void vdev_indirect_mark_obsolete(vdev_t *vd, uint64_t offset, uint64_t size) { spa_t *spa = vd->vdev_spa; ASSERT3U(vd->vdev_indirect_config.vic_mapping_object, !=, 0); ASSERT(vd->vdev_removing || vd->vdev_ops == &vdev_indirect_ops); ASSERT(size > 0); VERIFY(vdev_indirect_mapping_entry_for_offset( vd->vdev_indirect_mapping, offset) != NULL); if (spa_feature_is_enabled(spa, SPA_FEATURE_OBSOLETE_COUNTS)) { mutex_enter(&vd->vdev_obsolete_lock); range_tree_add(vd->vdev_obsolete_segments, offset, size); mutex_exit(&vd->vdev_obsolete_lock); vdev_dirty(vd, 0, NULL, spa_syncing_txg(spa)); } } /* * Mark the DVA vdev_id:offset:size as being obsolete in the given tx. This * wrapper is provided because the DMU does not know about vdev_t's and * cannot directly call vdev_indirect_mark_obsolete. */ void spa_vdev_indirect_mark_obsolete(spa_t *spa, uint64_t vdev_id, uint64_t offset, uint64_t size, dmu_tx_t *tx) { vdev_t *vd = vdev_lookup_top(spa, vdev_id); ASSERT(dmu_tx_is_syncing(tx)); /* The DMU can only remap indirect vdevs. */ ASSERT3P(vd->vdev_ops, ==, &vdev_indirect_ops); vdev_indirect_mark_obsolete(vd, offset, size); } static spa_condensing_indirect_t * spa_condensing_indirect_create(spa_t *spa) { spa_condensing_indirect_phys_t *scip = &spa->spa_condensing_indirect_phys; spa_condensing_indirect_t *sci = kmem_zalloc(sizeof (*sci), KM_SLEEP); objset_t *mos = spa->spa_meta_objset; for (int i = 0; i < TXG_SIZE; i++) { list_create(&sci->sci_new_mapping_entries[i], sizeof (vdev_indirect_mapping_entry_t), offsetof(vdev_indirect_mapping_entry_t, vime_node)); } sci->sci_new_mapping = vdev_indirect_mapping_open(mos, scip->scip_next_mapping_object); return (sci); } static void spa_condensing_indirect_destroy(spa_condensing_indirect_t *sci) { for (int i = 0; i < TXG_SIZE; i++) list_destroy(&sci->sci_new_mapping_entries[i]); if (sci->sci_new_mapping != NULL) vdev_indirect_mapping_close(sci->sci_new_mapping); kmem_free(sci, sizeof (*sci)); } boolean_t vdev_indirect_should_condense(vdev_t *vd) { vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping; spa_t *spa = vd->vdev_spa; ASSERT(dsl_pool_sync_context(spa->spa_dsl_pool)); if (!zfs_condense_indirect_vdevs_enable) return (B_FALSE); /* * We can only condense one indirect vdev at a time. */ if (spa->spa_condensing_indirect != NULL) return (B_FALSE); if (spa_shutting_down(spa)) return (B_FALSE); /* * The mapping object size must not change while we are * condensing, so we can only condense indirect vdevs * (not vdevs that are still in the middle of being removed). */ if (vd->vdev_ops != &vdev_indirect_ops) return (B_FALSE); /* * If nothing new has been marked obsolete, there is no * point in condensing. */ uint64_t obsolete_sm_obj __maybe_unused; ASSERT0(vdev_obsolete_sm_object(vd, &obsolete_sm_obj)); if (vd->vdev_obsolete_sm == NULL) { ASSERT0(obsolete_sm_obj); return (B_FALSE); } ASSERT(vd->vdev_obsolete_sm != NULL); ASSERT3U(obsolete_sm_obj, ==, space_map_object(vd->vdev_obsolete_sm)); uint64_t bytes_mapped = vdev_indirect_mapping_bytes_mapped(vim); uint64_t bytes_obsolete = space_map_allocated(vd->vdev_obsolete_sm); uint64_t mapping_size = vdev_indirect_mapping_size(vim); uint64_t obsolete_sm_size = space_map_length(vd->vdev_obsolete_sm); ASSERT3U(bytes_obsolete, <=, bytes_mapped); /* * If a high percentage of the bytes that are mapped have become * obsolete, condense (unless the mapping is already small enough). * This has a good chance of reducing the amount of memory used * by the mapping. */ if (bytes_obsolete * 100 / bytes_mapped >= zfs_indirect_condense_obsolete_pct && mapping_size > zfs_condense_min_mapping_bytes) { zfs_dbgmsg("should condense vdev %llu because obsolete " "spacemap covers %d%% of %lluMB mapping", (u_longlong_t)vd->vdev_id, (int)(bytes_obsolete * 100 / bytes_mapped), (u_longlong_t)bytes_mapped / 1024 / 1024); return (B_TRUE); } /* * If the obsolete space map takes up too much space on disk, * condense in order to free up this disk space. */ if (obsolete_sm_size >= zfs_condense_max_obsolete_bytes) { zfs_dbgmsg("should condense vdev %llu because obsolete sm " "length %lluMB >= max size %lluMB", (u_longlong_t)vd->vdev_id, (u_longlong_t)obsolete_sm_size / 1024 / 1024, (u_longlong_t)zfs_condense_max_obsolete_bytes / 1024 / 1024); return (B_TRUE); } return (B_FALSE); } /* * This sync task completes (finishes) a condense, deleting the old * mapping and replacing it with the new one. */ static void spa_condense_indirect_complete_sync(void *arg, dmu_tx_t *tx) { spa_condensing_indirect_t *sci = arg; spa_t *spa = dmu_tx_pool(tx)->dp_spa; spa_condensing_indirect_phys_t *scip = &spa->spa_condensing_indirect_phys; vdev_t *vd = vdev_lookup_top(spa, scip->scip_vdev); vdev_indirect_config_t *vic = &vd->vdev_indirect_config; objset_t *mos = spa->spa_meta_objset; vdev_indirect_mapping_t *old_mapping = vd->vdev_indirect_mapping; uint64_t old_count = vdev_indirect_mapping_num_entries(old_mapping); uint64_t new_count = vdev_indirect_mapping_num_entries(sci->sci_new_mapping); ASSERT(dmu_tx_is_syncing(tx)); ASSERT3P(vd->vdev_ops, ==, &vdev_indirect_ops); ASSERT3P(sci, ==, spa->spa_condensing_indirect); for (int i = 0; i < TXG_SIZE; i++) { ASSERT(list_is_empty(&sci->sci_new_mapping_entries[i])); } ASSERT(vic->vic_mapping_object != 0); ASSERT3U(vd->vdev_id, ==, scip->scip_vdev); ASSERT(scip->scip_next_mapping_object != 0); ASSERT(scip->scip_prev_obsolete_sm_object != 0); /* * Reset vdev_indirect_mapping to refer to the new object. */ rw_enter(&vd->vdev_indirect_rwlock, RW_WRITER); vdev_indirect_mapping_close(vd->vdev_indirect_mapping); vd->vdev_indirect_mapping = sci->sci_new_mapping; rw_exit(&vd->vdev_indirect_rwlock); sci->sci_new_mapping = NULL; vdev_indirect_mapping_free(mos, vic->vic_mapping_object, tx); vic->vic_mapping_object = scip->scip_next_mapping_object; scip->scip_next_mapping_object = 0; space_map_free_obj(mos, scip->scip_prev_obsolete_sm_object, tx); spa_feature_decr(spa, SPA_FEATURE_OBSOLETE_COUNTS, tx); scip->scip_prev_obsolete_sm_object = 0; scip->scip_vdev = 0; VERIFY0(zap_remove(mos, DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CONDENSING_INDIRECT, tx)); spa_condensing_indirect_destroy(spa->spa_condensing_indirect); spa->spa_condensing_indirect = NULL; zfs_dbgmsg("finished condense of vdev %llu in txg %llu: " "new mapping object %llu has %llu entries " "(was %llu entries)", vd->vdev_id, dmu_tx_get_txg(tx), vic->vic_mapping_object, new_count, old_count); vdev_config_dirty(spa->spa_root_vdev); } /* * This sync task appends entries to the new mapping object. */ static void spa_condense_indirect_commit_sync(void *arg, dmu_tx_t *tx) { spa_condensing_indirect_t *sci = arg; uint64_t txg = dmu_tx_get_txg(tx); spa_t *spa __maybe_unused = dmu_tx_pool(tx)->dp_spa; ASSERT(dmu_tx_is_syncing(tx)); ASSERT3P(sci, ==, spa->spa_condensing_indirect); vdev_indirect_mapping_add_entries(sci->sci_new_mapping, &sci->sci_new_mapping_entries[txg & TXG_MASK], tx); ASSERT(list_is_empty(&sci->sci_new_mapping_entries[txg & TXG_MASK])); } /* * Open-context function to add one entry to the new mapping. The new * entry will be remembered and written from syncing context. */ static void spa_condense_indirect_commit_entry(spa_t *spa, vdev_indirect_mapping_entry_phys_t *vimep, uint32_t count) { spa_condensing_indirect_t *sci = spa->spa_condensing_indirect; ASSERT3U(count, <, DVA_GET_ASIZE(&vimep->vimep_dst)); dmu_tx_t *tx = dmu_tx_create_dd(spa_get_dsl(spa)->dp_mos_dir); dmu_tx_hold_space(tx, sizeof (*vimep) + sizeof (count)); VERIFY0(dmu_tx_assign(tx, TXG_WAIT)); int txgoff = dmu_tx_get_txg(tx) & TXG_MASK; /* * If we are the first entry committed this txg, kick off the sync * task to write to the MOS on our behalf. */ if (list_is_empty(&sci->sci_new_mapping_entries[txgoff])) { dsl_sync_task_nowait(dmu_tx_pool(tx), spa_condense_indirect_commit_sync, sci, tx); } vdev_indirect_mapping_entry_t *vime = kmem_alloc(sizeof (*vime), KM_SLEEP); vime->vime_mapping = *vimep; vime->vime_obsolete_count = count; list_insert_tail(&sci->sci_new_mapping_entries[txgoff], vime); dmu_tx_commit(tx); } static void spa_condense_indirect_generate_new_mapping(vdev_t *vd, uint32_t *obsolete_counts, uint64_t start_index, zthr_t *zthr) { spa_t *spa = vd->vdev_spa; uint64_t mapi = start_index; vdev_indirect_mapping_t *old_mapping = vd->vdev_indirect_mapping; uint64_t old_num_entries = vdev_indirect_mapping_num_entries(old_mapping); ASSERT3P(vd->vdev_ops, ==, &vdev_indirect_ops); ASSERT3U(vd->vdev_id, ==, spa->spa_condensing_indirect_phys.scip_vdev); zfs_dbgmsg("starting condense of vdev %llu from index %llu", (u_longlong_t)vd->vdev_id, (u_longlong_t)mapi); while (mapi < old_num_entries) { if (zthr_iscancelled(zthr)) { zfs_dbgmsg("pausing condense of vdev %llu " "at index %llu", (u_longlong_t)vd->vdev_id, (u_longlong_t)mapi); break; } vdev_indirect_mapping_entry_phys_t *entry = &old_mapping->vim_entries[mapi]; uint64_t entry_size = DVA_GET_ASIZE(&entry->vimep_dst); ASSERT3U(obsolete_counts[mapi], <=, entry_size); if (obsolete_counts[mapi] < entry_size) { spa_condense_indirect_commit_entry(spa, entry, obsolete_counts[mapi]); /* * This delay may be requested for testing, debugging, * or performance reasons. */ hrtime_t now = gethrtime(); hrtime_t sleep_until = now + MSEC2NSEC( zfs_condense_indirect_commit_entry_delay_ms); zfs_sleep_until(sleep_until); } mapi++; } } /* ARGSUSED */ static boolean_t spa_condense_indirect_thread_check(void *arg, zthr_t *zthr) { spa_t *spa = arg; return (spa->spa_condensing_indirect != NULL); } /* ARGSUSED */ static void spa_condense_indirect_thread(void *arg, zthr_t *zthr) { spa_t *spa = arg; vdev_t *vd; ASSERT3P(spa->spa_condensing_indirect, !=, NULL); spa_config_enter(spa, SCL_VDEV, FTAG, RW_READER); vd = vdev_lookup_top(spa, spa->spa_condensing_indirect_phys.scip_vdev); ASSERT3P(vd, !=, NULL); spa_config_exit(spa, SCL_VDEV, FTAG); spa_condensing_indirect_t *sci = spa->spa_condensing_indirect; spa_condensing_indirect_phys_t *scip = &spa->spa_condensing_indirect_phys; uint32_t *counts; uint64_t start_index; vdev_indirect_mapping_t *old_mapping = vd->vdev_indirect_mapping; space_map_t *prev_obsolete_sm = NULL; ASSERT3U(vd->vdev_id, ==, scip->scip_vdev); ASSERT(scip->scip_next_mapping_object != 0); ASSERT(scip->scip_prev_obsolete_sm_object != 0); ASSERT3P(vd->vdev_ops, ==, &vdev_indirect_ops); for (int i = 0; i < TXG_SIZE; i++) { /* * The list must start out empty in order for the * _commit_sync() sync task to be properly registered * on the first call to _commit_entry(); so it's wise * to double check and ensure we actually are starting * with empty lists. */ ASSERT(list_is_empty(&sci->sci_new_mapping_entries[i])); } VERIFY0(space_map_open(&prev_obsolete_sm, spa->spa_meta_objset, scip->scip_prev_obsolete_sm_object, 0, vd->vdev_asize, 0)); counts = vdev_indirect_mapping_load_obsolete_counts(old_mapping); if (prev_obsolete_sm != NULL) { vdev_indirect_mapping_load_obsolete_spacemap(old_mapping, counts, prev_obsolete_sm); } space_map_close(prev_obsolete_sm); /* * Generate new mapping. Determine what index to continue from * based on the max offset that we've already written in the * new mapping. */ uint64_t max_offset = vdev_indirect_mapping_max_offset(sci->sci_new_mapping); if (max_offset == 0) { /* We haven't written anything to the new mapping yet. */ start_index = 0; } else { /* * Pick up from where we left off. _entry_for_offset() * returns a pointer into the vim_entries array. If * max_offset is greater than any of the mappings * contained in the table NULL will be returned and * that indicates we've exhausted our iteration of the * old_mapping. */ vdev_indirect_mapping_entry_phys_t *entry = vdev_indirect_mapping_entry_for_offset_or_next(old_mapping, max_offset); if (entry == NULL) { /* * We've already written the whole new mapping. * This special value will cause us to skip the * generate_new_mapping step and just do the sync * task to complete the condense. */ start_index = UINT64_MAX; } else { start_index = entry - old_mapping->vim_entries; ASSERT3U(start_index, <, vdev_indirect_mapping_num_entries(old_mapping)); } } spa_condense_indirect_generate_new_mapping(vd, counts, start_index, zthr); vdev_indirect_mapping_free_obsolete_counts(old_mapping, counts); /* * If the zthr has received a cancellation signal while running * in generate_new_mapping() or at any point after that, then bail * early. We don't want to complete the condense if the spa is * shutting down. */ if (zthr_iscancelled(zthr)) return; VERIFY0(dsl_sync_task(spa_name(spa), NULL, spa_condense_indirect_complete_sync, sci, 0, ZFS_SPACE_CHECK_EXTRA_RESERVED)); } /* * Sync task to begin the condensing process. */ void spa_condense_indirect_start_sync(vdev_t *vd, dmu_tx_t *tx) { spa_t *spa = vd->vdev_spa; spa_condensing_indirect_phys_t *scip = &spa->spa_condensing_indirect_phys; ASSERT0(scip->scip_next_mapping_object); ASSERT0(scip->scip_prev_obsolete_sm_object); ASSERT0(scip->scip_vdev); ASSERT(dmu_tx_is_syncing(tx)); ASSERT3P(vd->vdev_ops, ==, &vdev_indirect_ops); ASSERT(spa_feature_is_active(spa, SPA_FEATURE_OBSOLETE_COUNTS)); ASSERT(vdev_indirect_mapping_num_entries(vd->vdev_indirect_mapping)); uint64_t obsolete_sm_obj; VERIFY0(vdev_obsolete_sm_object(vd, &obsolete_sm_obj)); ASSERT3U(obsolete_sm_obj, !=, 0); scip->scip_vdev = vd->vdev_id; scip->scip_next_mapping_object = vdev_indirect_mapping_alloc(spa->spa_meta_objset, tx); scip->scip_prev_obsolete_sm_object = obsolete_sm_obj; /* * We don't need to allocate a new space map object, since * vdev_indirect_sync_obsolete will allocate one when needed. */ space_map_close(vd->vdev_obsolete_sm); vd->vdev_obsolete_sm = NULL; VERIFY0(zap_remove(spa->spa_meta_objset, vd->vdev_top_zap, VDEV_TOP_ZAP_INDIRECT_OBSOLETE_SM, tx)); VERIFY0(zap_add(spa->spa_dsl_pool->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CONDENSING_INDIRECT, sizeof (uint64_t), sizeof (*scip) / sizeof (uint64_t), scip, tx)); ASSERT3P(spa->spa_condensing_indirect, ==, NULL); spa->spa_condensing_indirect = spa_condensing_indirect_create(spa); zfs_dbgmsg("starting condense of vdev %llu in txg %llu: " "posm=%llu nm=%llu", vd->vdev_id, dmu_tx_get_txg(tx), (u_longlong_t)scip->scip_prev_obsolete_sm_object, (u_longlong_t)scip->scip_next_mapping_object); zthr_wakeup(spa->spa_condense_zthr); } /* * Sync to the given vdev's obsolete space map any segments that are no longer * referenced as of the given txg. * * If the obsolete space map doesn't exist yet, create and open it. */ void vdev_indirect_sync_obsolete(vdev_t *vd, dmu_tx_t *tx) { spa_t *spa = vd->vdev_spa; vdev_indirect_config_t *vic __maybe_unused = &vd->vdev_indirect_config; ASSERT3U(vic->vic_mapping_object, !=, 0); ASSERT(range_tree_space(vd->vdev_obsolete_segments) > 0); ASSERT(vd->vdev_removing || vd->vdev_ops == &vdev_indirect_ops); ASSERT(spa_feature_is_enabled(spa, SPA_FEATURE_OBSOLETE_COUNTS)); uint64_t obsolete_sm_object; VERIFY0(vdev_obsolete_sm_object(vd, &obsolete_sm_object)); if (obsolete_sm_object == 0) { obsolete_sm_object = space_map_alloc(spa->spa_meta_objset, zfs_vdev_standard_sm_blksz, tx); ASSERT(vd->vdev_top_zap != 0); VERIFY0(zap_add(vd->vdev_spa->spa_meta_objset, vd->vdev_top_zap, VDEV_TOP_ZAP_INDIRECT_OBSOLETE_SM, sizeof (obsolete_sm_object), 1, &obsolete_sm_object, tx)); ASSERT0(vdev_obsolete_sm_object(vd, &obsolete_sm_object)); ASSERT3U(obsolete_sm_object, !=, 0); spa_feature_incr(spa, SPA_FEATURE_OBSOLETE_COUNTS, tx); VERIFY0(space_map_open(&vd->vdev_obsolete_sm, spa->spa_meta_objset, obsolete_sm_object, 0, vd->vdev_asize, 0)); } ASSERT(vd->vdev_obsolete_sm != NULL); ASSERT3U(obsolete_sm_object, ==, space_map_object(vd->vdev_obsolete_sm)); space_map_write(vd->vdev_obsolete_sm, vd->vdev_obsolete_segments, SM_ALLOC, SM_NO_VDEVID, tx); range_tree_vacate(vd->vdev_obsolete_segments, NULL, NULL); } int spa_condense_init(spa_t *spa) { int error = zap_lookup(spa->spa_meta_objset, DMU_POOL_DIRECTORY_OBJECT, DMU_POOL_CONDENSING_INDIRECT, sizeof (uint64_t), sizeof (spa->spa_condensing_indirect_phys) / sizeof (uint64_t), &spa->spa_condensing_indirect_phys); if (error == 0) { if (spa_writeable(spa)) { spa->spa_condensing_indirect = spa_condensing_indirect_create(spa); } return (0); } else if (error == ENOENT) { return (0); } else { return (error); } } void spa_condense_fini(spa_t *spa) { if (spa->spa_condensing_indirect != NULL) { spa_condensing_indirect_destroy(spa->spa_condensing_indirect); spa->spa_condensing_indirect = NULL; } } void spa_start_indirect_condensing_thread(spa_t *spa) { ASSERT3P(spa->spa_condense_zthr, ==, NULL); spa->spa_condense_zthr = zthr_create("z_indirect_condense", spa_condense_indirect_thread_check, spa_condense_indirect_thread, spa); } /* * Gets the obsolete spacemap object from the vdev's ZAP. On success sm_obj * will contain either the obsolete spacemap object or zero if none exists. * All other errors are returned to the caller. */ int vdev_obsolete_sm_object(vdev_t *vd, uint64_t *sm_obj) { ASSERT0(spa_config_held(vd->vdev_spa, SCL_ALL, RW_WRITER)); if (vd->vdev_top_zap == 0) { *sm_obj = 0; return (0); } int error = zap_lookup(vd->vdev_spa->spa_meta_objset, vd->vdev_top_zap, VDEV_TOP_ZAP_INDIRECT_OBSOLETE_SM, sizeof (uint64_t), 1, sm_obj); if (error == ENOENT) { *sm_obj = 0; error = 0; } return (error); } /* * Gets the obsolete count are precise spacemap object from the vdev's ZAP. * On success are_precise will be set to reflect if the counts are precise. * All other errors are returned to the caller. */ int vdev_obsolete_counts_are_precise(vdev_t *vd, boolean_t *are_precise) { ASSERT0(spa_config_held(vd->vdev_spa, SCL_ALL, RW_WRITER)); if (vd->vdev_top_zap == 0) { *are_precise = B_FALSE; return (0); } uint64_t val = 0; int error = zap_lookup(vd->vdev_spa->spa_meta_objset, vd->vdev_top_zap, VDEV_TOP_ZAP_OBSOLETE_COUNTS_ARE_PRECISE, sizeof (val), 1, &val); if (error == 0) { *are_precise = (val != 0); } else if (error == ENOENT) { *are_precise = B_FALSE; error = 0; } return (error); } /* ARGSUSED */ static void vdev_indirect_close(vdev_t *vd) { } /* ARGSUSED */ static int vdev_indirect_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize, uint64_t *logical_ashift, uint64_t *physical_ashift) { *psize = *max_psize = vd->vdev_asize + VDEV_LABEL_START_SIZE + VDEV_LABEL_END_SIZE; *logical_ashift = vd->vdev_ashift; *physical_ashift = vd->vdev_physical_ashift; return (0); } typedef struct remap_segment { vdev_t *rs_vd; uint64_t rs_offset; uint64_t rs_asize; uint64_t rs_split_offset; list_node_t rs_node; } remap_segment_t; static remap_segment_t * rs_alloc(vdev_t *vd, uint64_t offset, uint64_t asize, uint64_t split_offset) { remap_segment_t *rs = kmem_alloc(sizeof (remap_segment_t), KM_SLEEP); rs->rs_vd = vd; rs->rs_offset = offset; rs->rs_asize = asize; rs->rs_split_offset = split_offset; return (rs); } /* * Given an indirect vdev and an extent on that vdev, it duplicates the * physical entries of the indirect mapping that correspond to the extent * to a new array and returns a pointer to it. In addition, copied_entries * is populated with the number of mapping entries that were duplicated. * * Note that the function assumes that the caller holds vdev_indirect_rwlock. * This ensures that the mapping won't change due to condensing as we * copy over its contents. * * Finally, since we are doing an allocation, it is up to the caller to * free the array allocated in this function. */ static vdev_indirect_mapping_entry_phys_t * vdev_indirect_mapping_duplicate_adjacent_entries(vdev_t *vd, uint64_t offset, uint64_t asize, uint64_t *copied_entries) { vdev_indirect_mapping_entry_phys_t *duplicate_mappings = NULL; vdev_indirect_mapping_t *vim = vd->vdev_indirect_mapping; uint64_t entries = 0; ASSERT(RW_READ_HELD(&vd->vdev_indirect_rwlock)); vdev_indirect_mapping_entry_phys_t *first_mapping = vdev_indirect_mapping_entry_for_offset(vim, offset); ASSERT3P(first_mapping, !=, NULL); vdev_indirect_mapping_entry_phys_t *m = first_mapping; while (asize > 0) { uint64_t size = DVA_GET_ASIZE(&m->vimep_dst); ASSERT3U(offset, >=, DVA_MAPPING_GET_SRC_OFFSET(m)); ASSERT3U(offset, <, DVA_MAPPING_GET_SRC_OFFSET(m) + size); uint64_t inner_offset = offset - DVA_MAPPING_GET_SRC_OFFSET(m); uint64_t inner_size = MIN(asize, size - inner_offset); offset += inner_size; asize -= inner_size; entries++; m++; } size_t copy_length = entries * sizeof (*first_mapping); duplicate_mappings = kmem_alloc(copy_length, KM_SLEEP); bcopy(first_mapping, duplicate_mappings, copy_length); *copied_entries = entries; return (duplicate_mappings); } /* * Goes through the relevant indirect mappings until it hits a concrete vdev * and issues the callback. On the way to the concrete vdev, if any other * indirect vdevs are encountered, then the callback will also be called on * each of those indirect vdevs. For example, if the segment is mapped to * segment A on indirect vdev 1, and then segment A on indirect vdev 1 is * mapped to segment B on concrete vdev 2, then the callback will be called on * both vdev 1 and vdev 2. * * While the callback passed to vdev_indirect_remap() is called on every vdev * the function encounters, certain callbacks only care about concrete vdevs. * These types of callbacks should return immediately and explicitly when they * are called on an indirect vdev. * * Because there is a possibility that a DVA section in the indirect device * has been split into multiple sections in our mapping, we keep track * of the relevant contiguous segments of the new location (remap_segment_t) * in a stack. This way we can call the callback for each of the new sections * created by a single section of the indirect device. Note though, that in * this scenario the callbacks in each split block won't occur in-order in * terms of offset, so callers should not make any assumptions about that. * * For callbacks that don't handle split blocks and immediately return when * they encounter them (as is the case for remap_blkptr_cb), the caller can * assume that its callback will be applied from the first indirect vdev * encountered to the last one and then the concrete vdev, in that order. */ static void vdev_indirect_remap(vdev_t *vd, uint64_t offset, uint64_t asize, void (*func)(uint64_t, vdev_t *, uint64_t, uint64_t, void *), void *arg) { list_t stack; spa_t *spa = vd->vdev_spa; list_create(&stack, sizeof (remap_segment_t), offsetof(remap_segment_t, rs_node)); for (remap_segment_t *rs = rs_alloc(vd, offset, asize, 0); rs != NULL; rs = list_remove_head(&stack)) { vdev_t *v = rs->rs_vd; uint64_t num_entries = 0; ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0); ASSERT(rs->rs_asize > 0); /* * Note: As this function can be called from open context * (e.g. zio_read()), we need the following rwlock to * prevent the mapping from being changed by condensing. * * So we grab the lock and we make a copy of the entries * that are relevant to the extent that we are working on. * Once that is done, we drop the lock and iterate over * our copy of the mapping. Once we are done with the with * the remap segment and we free it, we also free our copy * of the indirect mapping entries that are relevant to it. * * This way we don't need to wait until the function is * finished with a segment, to condense it. In addition, we * don't need a recursive rwlock for the case that a call to * vdev_indirect_remap() needs to call itself (through the * codepath of its callback) for the same vdev in the middle * of its execution. */ rw_enter(&v->vdev_indirect_rwlock, RW_READER); ASSERT3P(v->vdev_indirect_mapping, !=, NULL); vdev_indirect_mapping_entry_phys_t *mapping = vdev_indirect_mapping_duplicate_adjacent_entries(v, rs->rs_offset, rs->rs_asize, &num_entries); ASSERT3P(mapping, !=, NULL); ASSERT3U(num_entries, >, 0); rw_exit(&v->vdev_indirect_rwlock); for (uint64_t i = 0; i < num_entries; i++) { /* * Note: the vdev_indirect_mapping can not change * while we are running. It only changes while the * removal is in progress, and then only from syncing * context. While a removal is in progress, this * function is only called for frees, which also only * happen from syncing context. */ vdev_indirect_mapping_entry_phys_t *m = &mapping[i]; ASSERT3P(m, !=, NULL); ASSERT3U(rs->rs_asize, >, 0); uint64_t size = DVA_GET_ASIZE(&m->vimep_dst); uint64_t dst_offset = DVA_GET_OFFSET(&m->vimep_dst); uint64_t dst_vdev = DVA_GET_VDEV(&m->vimep_dst); ASSERT3U(rs->rs_offset, >=, DVA_MAPPING_GET_SRC_OFFSET(m)); ASSERT3U(rs->rs_offset, <, DVA_MAPPING_GET_SRC_OFFSET(m) + size); ASSERT3U(dst_vdev, !=, v->vdev_id); uint64_t inner_offset = rs->rs_offset - DVA_MAPPING_GET_SRC_OFFSET(m); uint64_t inner_size = MIN(rs->rs_asize, size - inner_offset); vdev_t *dst_v = vdev_lookup_top(spa, dst_vdev); ASSERT3P(dst_v, !=, NULL); if (dst_v->vdev_ops == &vdev_indirect_ops) { list_insert_head(&stack, rs_alloc(dst_v, dst_offset + inner_offset, inner_size, rs->rs_split_offset)); } if ((zfs_flags & ZFS_DEBUG_INDIRECT_REMAP) && IS_P2ALIGNED(inner_size, 2 * SPA_MINBLOCKSIZE)) { /* * Note: This clause exists only solely for * testing purposes. We use it to ensure that * split blocks work and that the callbacks * using them yield the same result if issued * in reverse order. */ uint64_t inner_half = inner_size / 2; func(rs->rs_split_offset + inner_half, dst_v, dst_offset + inner_offset + inner_half, inner_half, arg); func(rs->rs_split_offset, dst_v, dst_offset + inner_offset, inner_half, arg); } else { func(rs->rs_split_offset, dst_v, dst_offset + inner_offset, inner_size, arg); } rs->rs_offset += inner_size; rs->rs_asize -= inner_size; rs->rs_split_offset += inner_size; } VERIFY0(rs->rs_asize); kmem_free(mapping, num_entries * sizeof (*mapping)); kmem_free(rs, sizeof (remap_segment_t)); } list_destroy(&stack); } static void vdev_indirect_child_io_done(zio_t *zio) { zio_t *pio = zio->io_private; mutex_enter(&pio->io_lock); pio->io_error = zio_worst_error(pio->io_error, zio->io_error); mutex_exit(&pio->io_lock); - abd_put(zio->io_abd); + abd_free(zio->io_abd); } /* * This is a callback for vdev_indirect_remap() which allocates an * indirect_split_t for each split segment and adds it to iv_splits. */ static void vdev_indirect_gather_splits(uint64_t split_offset, vdev_t *vd, uint64_t offset, uint64_t size, void *arg) { zio_t *zio = arg; indirect_vsd_t *iv = zio->io_vsd; ASSERT3P(vd, !=, NULL); if (vd->vdev_ops == &vdev_indirect_ops) return; int n = 1; if (vd->vdev_ops == &vdev_mirror_ops) n = vd->vdev_children; indirect_split_t *is = kmem_zalloc(offsetof(indirect_split_t, is_child[n]), KM_SLEEP); is->is_children = n; is->is_size = size; is->is_split_offset = split_offset; is->is_target_offset = offset; is->is_vdev = vd; list_create(&is->is_unique_child, sizeof (indirect_child_t), offsetof(indirect_child_t, ic_node)); /* * Note that we only consider multiple copies of the data for * *mirror* vdevs. We don't for "replacing" or "spare" vdevs, even * though they use the same ops as mirror, because there's only one * "good" copy under the replacing/spare. */ if (vd->vdev_ops == &vdev_mirror_ops) { for (int i = 0; i < n; i++) { is->is_child[i].ic_vdev = vd->vdev_child[i]; list_link_init(&is->is_child[i].ic_node); } } else { is->is_child[0].ic_vdev = vd; } list_insert_tail(&iv->iv_splits, is); } static void vdev_indirect_read_split_done(zio_t *zio) { indirect_child_t *ic = zio->io_private; if (zio->io_error != 0) { /* * Clear ic_data to indicate that we do not have data for this * child. */ abd_free(ic->ic_data); ic->ic_data = NULL; } } /* * Issue reads for all copies (mirror children) of all splits. */ static void vdev_indirect_read_all(zio_t *zio) { indirect_vsd_t *iv = zio->io_vsd; ASSERT3U(zio->io_type, ==, ZIO_TYPE_READ); for (indirect_split_t *is = list_head(&iv->iv_splits); is != NULL; is = list_next(&iv->iv_splits, is)) { for (int i = 0; i < is->is_children; i++) { indirect_child_t *ic = &is->is_child[i]; if (!vdev_readable(ic->ic_vdev)) continue; /* * If a child is missing the data, set ic_error. Used * in vdev_indirect_repair(). We perform the read * nevertheless which provides the opportunity to * reconstruct the split block if at all possible. */ if (vdev_dtl_contains(ic->ic_vdev, DTL_MISSING, zio->io_txg, 1)) ic->ic_error = SET_ERROR(ESTALE); ic->ic_data = abd_alloc_sametype(zio->io_abd, is->is_size); ic->ic_duplicate = NULL; zio_nowait(zio_vdev_child_io(zio, NULL, ic->ic_vdev, is->is_target_offset, ic->ic_data, is->is_size, zio->io_type, zio->io_priority, 0, vdev_indirect_read_split_done, ic)); } } iv->iv_reconstruct = B_TRUE; } static void vdev_indirect_io_start(zio_t *zio) { spa_t *spa __maybe_unused = zio->io_spa; indirect_vsd_t *iv = kmem_zalloc(sizeof (*iv), KM_SLEEP); list_create(&iv->iv_splits, sizeof (indirect_split_t), offsetof(indirect_split_t, is_node)); zio->io_vsd = iv; zio->io_vsd_ops = &vdev_indirect_vsd_ops; ASSERT(spa_config_held(spa, SCL_ALL, RW_READER) != 0); if (zio->io_type != ZIO_TYPE_READ) { ASSERT3U(zio->io_type, ==, ZIO_TYPE_WRITE); /* * Note: this code can handle other kinds of writes, * but we don't expect them. */ ASSERT((zio->io_flags & (ZIO_FLAG_SELF_HEAL | ZIO_FLAG_RESILVER | ZIO_FLAG_INDUCE_DAMAGE)) != 0); } vdev_indirect_remap(zio->io_vd, zio->io_offset, zio->io_size, vdev_indirect_gather_splits, zio); indirect_split_t *first = list_head(&iv->iv_splits); if (first->is_size == zio->io_size) { /* * This is not a split block; we are pointing to the entire * data, which will checksum the same as the original data. * Pass the BP down so that the child i/o can verify the * checksum, and try a different location if available * (e.g. on a mirror). * * While this special case could be handled the same as the * general (split block) case, doing it this way ensures * that the vast majority of blocks on indirect vdevs * (which are not split) are handled identically to blocks * on non-indirect vdevs. This allows us to be less strict * about performance in the general (but rare) case. */ ASSERT0(first->is_split_offset); ASSERT3P(list_next(&iv->iv_splits, first), ==, NULL); zio_nowait(zio_vdev_child_io(zio, zio->io_bp, first->is_vdev, first->is_target_offset, abd_get_offset(zio->io_abd, 0), zio->io_size, zio->io_type, zio->io_priority, 0, vdev_indirect_child_io_done, zio)); } else { iv->iv_split_block = B_TRUE; if (zio->io_type == ZIO_TYPE_READ && zio->io_flags & (ZIO_FLAG_SCRUB | ZIO_FLAG_RESILVER)) { /* * Read all copies. Note that for simplicity, * we don't bother consulting the DTL in the * resilver case. */ vdev_indirect_read_all(zio); } else { /* * If this is a read zio, we read one copy of each * split segment, from the top-level vdev. Since * we don't know the checksum of each split * individually, the child zio can't ensure that * we get the right data. E.g. if it's a mirror, * it will just read from a random (healthy) leaf * vdev. We have to verify the checksum in * vdev_indirect_io_done(). * * For write zios, the vdev code will ensure we write * to all children. */ for (indirect_split_t *is = list_head(&iv->iv_splits); is != NULL; is = list_next(&iv->iv_splits, is)) { zio_nowait(zio_vdev_child_io(zio, NULL, is->is_vdev, is->is_target_offset, abd_get_offset(zio->io_abd, is->is_split_offset), is->is_size, zio->io_type, zio->io_priority, 0, vdev_indirect_child_io_done, zio)); } } } zio_execute(zio); } /* * Report a checksum error for a child. */ static void vdev_indirect_checksum_error(zio_t *zio, indirect_split_t *is, indirect_child_t *ic) { vdev_t *vd = ic->ic_vdev; if (zio->io_flags & ZIO_FLAG_SPECULATIVE) return; mutex_enter(&vd->vdev_stat_lock); vd->vdev_stat.vs_checksum_errors++; mutex_exit(&vd->vdev_stat_lock); zio_bad_cksum_t zbc = {{{ 0 }}}; abd_t *bad_abd = ic->ic_data; abd_t *good_abd = is->is_good_child->ic_data; (void) zfs_ereport_post_checksum(zio->io_spa, vd, NULL, zio, is->is_target_offset, is->is_size, good_abd, bad_abd, &zbc); } /* * Issue repair i/os for any incorrect copies. We do this by comparing * each split segment's correct data (is_good_child's ic_data) with each * other copy of the data. If they differ, then we overwrite the bad data * with the good copy. The DTL is checked in vdev_indirect_read_all() and * if a vdev is missing a copy of the data we set ic_error and the read is * performed. This provides the opportunity to reconstruct the split block * if at all possible. ic_error is checked here and if set it suppresses * incrementing the checksum counter. Aside from this DTLs are not checked, * which simplifies this code and also issues the optimal number of writes * (based on which copies actually read bad data, as opposed to which we * think might be wrong). For the same reason, we always use * ZIO_FLAG_SELF_HEAL, to bypass the DTL check in zio_vdev_io_start(). */ static void vdev_indirect_repair(zio_t *zio) { indirect_vsd_t *iv = zio->io_vsd; enum zio_flag flags = ZIO_FLAG_IO_REPAIR; if (!(zio->io_flags & (ZIO_FLAG_SCRUB | ZIO_FLAG_RESILVER))) flags |= ZIO_FLAG_SELF_HEAL; if (!spa_writeable(zio->io_spa)) return; for (indirect_split_t *is = list_head(&iv->iv_splits); is != NULL; is = list_next(&iv->iv_splits, is)) { for (int c = 0; c < is->is_children; c++) { indirect_child_t *ic = &is->is_child[c]; if (ic == is->is_good_child) continue; if (ic->ic_data == NULL) continue; if (ic->ic_duplicate == is->is_good_child) continue; zio_nowait(zio_vdev_child_io(zio, NULL, ic->ic_vdev, is->is_target_offset, is->is_good_child->ic_data, is->is_size, ZIO_TYPE_WRITE, ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_IO_REPAIR | ZIO_FLAG_SELF_HEAL, NULL, NULL)); /* * If ic_error is set the current child does not have * a copy of the data, so suppress incrementing the * checksum counter. */ if (ic->ic_error == ESTALE) continue; vdev_indirect_checksum_error(zio, is, ic); } } } /* * Report checksum errors on all children that we read from. */ static void vdev_indirect_all_checksum_errors(zio_t *zio) { indirect_vsd_t *iv = zio->io_vsd; if (zio->io_flags & ZIO_FLAG_SPECULATIVE) return; for (indirect_split_t *is = list_head(&iv->iv_splits); is != NULL; is = list_next(&iv->iv_splits, is)) { for (int c = 0; c < is->is_children; c++) { indirect_child_t *ic = &is->is_child[c]; if (ic->ic_data == NULL) continue; vdev_t *vd = ic->ic_vdev; int ret = zfs_ereport_post_checksum(zio->io_spa, vd, NULL, zio, is->is_target_offset, is->is_size, NULL, NULL, NULL); if (ret != EALREADY) { mutex_enter(&vd->vdev_stat_lock); vd->vdev_stat.vs_checksum_errors++; mutex_exit(&vd->vdev_stat_lock); } } } } /* * Copy data from all the splits to a main zio then validate the checksum. * If then checksum is successfully validated return success. */ static int vdev_indirect_splits_checksum_validate(indirect_vsd_t *iv, zio_t *zio) { zio_bad_cksum_t zbc; for (indirect_split_t *is = list_head(&iv->iv_splits); is != NULL; is = list_next(&iv->iv_splits, is)) { ASSERT3P(is->is_good_child->ic_data, !=, NULL); ASSERT3P(is->is_good_child->ic_duplicate, ==, NULL); abd_copy_off(zio->io_abd, is->is_good_child->ic_data, is->is_split_offset, 0, is->is_size); } return (zio_checksum_error(zio, &zbc)); } /* * There are relatively few possible combinations making it feasible to * deterministically check them all. We do this by setting the good_child * to the next unique split version. If we reach the end of the list then * "carry over" to the next unique split version (like counting in base * is_unique_children, but each digit can have a different base). */ static int vdev_indirect_splits_enumerate_all(indirect_vsd_t *iv, zio_t *zio) { boolean_t more = B_TRUE; iv->iv_attempts = 0; for (indirect_split_t *is = list_head(&iv->iv_splits); is != NULL; is = list_next(&iv->iv_splits, is)) is->is_good_child = list_head(&is->is_unique_child); while (more == B_TRUE) { iv->iv_attempts++; more = B_FALSE; if (vdev_indirect_splits_checksum_validate(iv, zio) == 0) return (0); for (indirect_split_t *is = list_head(&iv->iv_splits); is != NULL; is = list_next(&iv->iv_splits, is)) { is->is_good_child = list_next(&is->is_unique_child, is->is_good_child); if (is->is_good_child != NULL) { more = B_TRUE; break; } is->is_good_child = list_head(&is->is_unique_child); } } ASSERT3S(iv->iv_attempts, <=, iv->iv_unique_combinations); return (SET_ERROR(ECKSUM)); } /* * There are too many combinations to try all of them in a reasonable amount * of time. So try a fixed number of random combinations from the unique * split versions, after which we'll consider the block unrecoverable. */ static int vdev_indirect_splits_enumerate_randomly(indirect_vsd_t *iv, zio_t *zio) { iv->iv_attempts = 0; while (iv->iv_attempts < iv->iv_attempts_max) { iv->iv_attempts++; for (indirect_split_t *is = list_head(&iv->iv_splits); is != NULL; is = list_next(&iv->iv_splits, is)) { indirect_child_t *ic = list_head(&is->is_unique_child); int children = is->is_unique_children; for (int i = spa_get_random(children); i > 0; i--) ic = list_next(&is->is_unique_child, ic); ASSERT3P(ic, !=, NULL); is->is_good_child = ic; } if (vdev_indirect_splits_checksum_validate(iv, zio) == 0) return (0); } return (SET_ERROR(ECKSUM)); } /* * This is a validation function for reconstruction. It randomly selects * a good combination, if one can be found, and then it intentionally * damages all other segment copes by zeroing them. This forces the * reconstruction algorithm to locate the one remaining known good copy. */ static int vdev_indirect_splits_damage(indirect_vsd_t *iv, zio_t *zio) { int error; /* Presume all the copies are unique for initial selection. */ for (indirect_split_t *is = list_head(&iv->iv_splits); is != NULL; is = list_next(&iv->iv_splits, is)) { is->is_unique_children = 0; for (int i = 0; i < is->is_children; i++) { indirect_child_t *ic = &is->is_child[i]; if (ic->ic_data != NULL) { is->is_unique_children++; list_insert_tail(&is->is_unique_child, ic); } } if (list_is_empty(&is->is_unique_child)) { error = SET_ERROR(EIO); goto out; } } /* * Set each is_good_child to a randomly-selected child which * is known to contain validated data. */ error = vdev_indirect_splits_enumerate_randomly(iv, zio); if (error) goto out; /* * Damage all but the known good copy by zeroing it. This will * result in two or less unique copies per indirect_child_t. * Both may need to be checked in order to reconstruct the block. * Set iv->iv_attempts_max such that all unique combinations will * enumerated, but limit the damage to at most 12 indirect splits. */ iv->iv_attempts_max = 1; for (indirect_split_t *is = list_head(&iv->iv_splits); is != NULL; is = list_next(&iv->iv_splits, is)) { for (int c = 0; c < is->is_children; c++) { indirect_child_t *ic = &is->is_child[c]; if (ic == is->is_good_child) continue; if (ic->ic_data == NULL) continue; abd_zero(ic->ic_data, abd_get_size(ic->ic_data)); } iv->iv_attempts_max *= 2; if (iv->iv_attempts_max >= (1ULL << 12)) { iv->iv_attempts_max = UINT64_MAX; break; } } out: /* Empty the unique children lists so they can be reconstructed. */ for (indirect_split_t *is = list_head(&iv->iv_splits); is != NULL; is = list_next(&iv->iv_splits, is)) { indirect_child_t *ic; while ((ic = list_head(&is->is_unique_child)) != NULL) list_remove(&is->is_unique_child, ic); is->is_unique_children = 0; } return (error); } /* * This function is called when we have read all copies of the data and need * to try to find a combination of copies that gives us the right checksum. * * If we pointed to any mirror vdevs, this effectively does the job of the * mirror. The mirror vdev code can't do its own job because we don't know * the checksum of each split segment individually. * * We have to try every unique combination of copies of split segments, until * we find one that checksums correctly. Duplicate segment copies are first * identified and latter skipped during reconstruction. This optimization * reduces the search space and ensures that of the remaining combinations * at most one is correct. * * When the total number of combinations is small they can all be checked. * For example, if we have 3 segments in the split, and each points to a * 2-way mirror with unique copies, we will have the following pieces of data: * * | mirror child * split | [0] [1] * ======|===================== * A | data_A_0 data_A_1 * B | data_B_0 data_B_1 * C | data_C_0 data_C_1 * * We will try the following (mirror children)^(number of splits) (2^3=8) * combinations, which is similar to bitwise-little-endian counting in * binary. In general each "digit" corresponds to a split segment, and the * base of each digit is is_children, which can be different for each * digit. * * "low bit" "high bit" * v v * data_A_0 data_B_0 data_C_0 * data_A_1 data_B_0 data_C_0 * data_A_0 data_B_1 data_C_0 * data_A_1 data_B_1 data_C_0 * data_A_0 data_B_0 data_C_1 * data_A_1 data_B_0 data_C_1 * data_A_0 data_B_1 data_C_1 * data_A_1 data_B_1 data_C_1 * * Note that the split segments may be on the same or different top-level * vdevs. In either case, we may need to try lots of combinations (see * zfs_reconstruct_indirect_combinations_max). This ensures that if a mirror * has small silent errors on all of its children, we can still reconstruct * the correct data, as long as those errors are at sufficiently-separated * offsets (specifically, separated by the largest block size - default of * 128KB, but up to 16MB). */ static void vdev_indirect_reconstruct_io_done(zio_t *zio) { indirect_vsd_t *iv = zio->io_vsd; boolean_t known_good = B_FALSE; int error; iv->iv_unique_combinations = 1; iv->iv_attempts_max = UINT64_MAX; if (zfs_reconstruct_indirect_combinations_max > 0) iv->iv_attempts_max = zfs_reconstruct_indirect_combinations_max; /* * If nonzero, every 1/x blocks will be damaged, in order to validate * reconstruction when there are split segments with damaged copies. * Known_good will be TRUE when reconstruction is known to be possible. */ if (zfs_reconstruct_indirect_damage_fraction != 0 && spa_get_random(zfs_reconstruct_indirect_damage_fraction) == 0) known_good = (vdev_indirect_splits_damage(iv, zio) == 0); /* * Determine the unique children for a split segment and add them * to the is_unique_child list. By restricting reconstruction * to these children, only unique combinations will be considered. * This can vastly reduce the search space when there are a large * number of indirect splits. */ for (indirect_split_t *is = list_head(&iv->iv_splits); is != NULL; is = list_next(&iv->iv_splits, is)) { is->is_unique_children = 0; for (int i = 0; i < is->is_children; i++) { indirect_child_t *ic_i = &is->is_child[i]; if (ic_i->ic_data == NULL || ic_i->ic_duplicate != NULL) continue; for (int j = i + 1; j < is->is_children; j++) { indirect_child_t *ic_j = &is->is_child[j]; if (ic_j->ic_data == NULL || ic_j->ic_duplicate != NULL) continue; if (abd_cmp(ic_i->ic_data, ic_j->ic_data) == 0) ic_j->ic_duplicate = ic_i; } is->is_unique_children++; list_insert_tail(&is->is_unique_child, ic_i); } /* Reconstruction is impossible, no valid children */ EQUIV(list_is_empty(&is->is_unique_child), is->is_unique_children == 0); if (list_is_empty(&is->is_unique_child)) { zio->io_error = EIO; vdev_indirect_all_checksum_errors(zio); zio_checksum_verified(zio); return; } iv->iv_unique_combinations *= is->is_unique_children; } if (iv->iv_unique_combinations <= iv->iv_attempts_max) error = vdev_indirect_splits_enumerate_all(iv, zio); else error = vdev_indirect_splits_enumerate_randomly(iv, zio); if (error != 0) { /* All attempted combinations failed. */ ASSERT3B(known_good, ==, B_FALSE); zio->io_error = error; vdev_indirect_all_checksum_errors(zio); } else { /* * The checksum has been successfully validated. Issue * repair I/Os to any copies of splits which don't match * the validated version. */ ASSERT0(vdev_indirect_splits_checksum_validate(iv, zio)); vdev_indirect_repair(zio); zio_checksum_verified(zio); } } static void vdev_indirect_io_done(zio_t *zio) { indirect_vsd_t *iv = zio->io_vsd; if (iv->iv_reconstruct) { /* * We have read all copies of the data (e.g. from mirrors), * either because this was a scrub/resilver, or because the * one-copy read didn't checksum correctly. */ vdev_indirect_reconstruct_io_done(zio); return; } if (!iv->iv_split_block) { /* * This was not a split block, so we passed the BP down, * and the checksum was handled by the (one) child zio. */ return; } zio_bad_cksum_t zbc; int ret = zio_checksum_error(zio, &zbc); if (ret == 0) { zio_checksum_verified(zio); return; } /* * The checksum didn't match. Read all copies of all splits, and * then we will try to reconstruct. The next time * vdev_indirect_io_done() is called, iv_reconstruct will be set. */ vdev_indirect_read_all(zio); zio_vdev_io_redone(zio); } vdev_ops_t vdev_indirect_ops = { .vdev_op_init = NULL, .vdev_op_fini = NULL, .vdev_op_open = vdev_indirect_open, .vdev_op_close = vdev_indirect_close, .vdev_op_asize = vdev_default_asize, .vdev_op_min_asize = vdev_default_min_asize, .vdev_op_min_alloc = NULL, .vdev_op_io_start = vdev_indirect_io_start, .vdev_op_io_done = vdev_indirect_io_done, .vdev_op_state_change = NULL, .vdev_op_need_resilver = NULL, .vdev_op_hold = NULL, .vdev_op_rele = NULL, .vdev_op_remap = vdev_indirect_remap, .vdev_op_xlate = NULL, .vdev_op_rebuild_asize = NULL, .vdev_op_metaslab_init = NULL, .vdev_op_config_generate = NULL, .vdev_op_nparity = NULL, .vdev_op_ndisks = NULL, .vdev_op_type = VDEV_TYPE_INDIRECT, /* name of this vdev type */ .vdev_op_leaf = B_FALSE /* leaf vdev */ }; EXPORT_SYMBOL(spa_condense_fini); EXPORT_SYMBOL(spa_start_indirect_condensing_thread); EXPORT_SYMBOL(spa_condense_indirect_start_sync); EXPORT_SYMBOL(spa_condense_init); EXPORT_SYMBOL(spa_vdev_indirect_mark_obsolete); EXPORT_SYMBOL(vdev_indirect_mark_obsolete); EXPORT_SYMBOL(vdev_indirect_should_condense); EXPORT_SYMBOL(vdev_indirect_sync_obsolete); EXPORT_SYMBOL(vdev_obsolete_counts_are_precise); EXPORT_SYMBOL(vdev_obsolete_sm_object); /* BEGIN CSTYLED */ ZFS_MODULE_PARAM(zfs_condense, zfs_condense_, indirect_vdevs_enable, INT, ZMOD_RW, "Whether to attempt condensing indirect vdev mappings"); ZFS_MODULE_PARAM(zfs_condense, zfs_condense_, min_mapping_bytes, ULONG, ZMOD_RW, "Don't bother condensing if the mapping uses less than this amount of " "memory"); ZFS_MODULE_PARAM(zfs_condense, zfs_condense_, max_obsolete_bytes, ULONG, ZMOD_RW, "Minimum size obsolete spacemap to attempt condensing"); ZFS_MODULE_PARAM(zfs_condense, zfs_condense_, indirect_commit_entry_delay_ms, INT, ZMOD_RW, "Used by tests to ensure certain actions happen in the middle of a " "condense. A maximum value of 1 should be sufficient."); ZFS_MODULE_PARAM(zfs_reconstruct, zfs_reconstruct_, indirect_combinations_max, INT, ZMOD_RW, "Maximum number of combinations when reconstructing split segments"); /* END CSTYLED */ diff --git a/module/zfs/vdev_queue.c b/module/zfs/vdev_queue.c index 02040c3ee198..25a4bc69cc23 100644 --- a/module/zfs/vdev_queue.c +++ b/module/zfs/vdev_queue.c @@ -1,1164 +1,1164 @@ /* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright 2009 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ /* * Copyright (c) 2012, 2018 by Delphix. All rights reserved. */ #include #include #include #include #include #include #include #include #include #include #include /* * ZFS I/O Scheduler * --------------- * * ZFS issues I/O operations to leaf vdevs to satisfy and complete zios. The * I/O scheduler determines when and in what order those operations are * issued. The I/O scheduler divides operations into five I/O classes * prioritized in the following order: sync read, sync write, async read, * async write, and scrub/resilver. Each queue defines the minimum and * maximum number of concurrent operations that may be issued to the device. * In addition, the device has an aggregate maximum. Note that the sum of the * per-queue minimums must not exceed the aggregate maximum. If the * sum of the per-queue maximums exceeds the aggregate maximum, then the * number of active i/os may reach zfs_vdev_max_active, in which case no * further i/os will be issued regardless of whether all per-queue * minimums have been met. * * For many physical devices, throughput increases with the number of * concurrent operations, but latency typically suffers. Further, physical * devices typically have a limit at which more concurrent operations have no * effect on throughput or can actually cause it to decrease. * * The scheduler selects the next operation to issue by first looking for an * I/O class whose minimum has not been satisfied. Once all are satisfied and * the aggregate maximum has not been hit, the scheduler looks for classes * whose maximum has not been satisfied. Iteration through the I/O classes is * done in the order specified above. No further operations are issued if the * aggregate maximum number of concurrent operations has been hit or if there * are no operations queued for an I/O class that has not hit its maximum. * Every time an i/o is queued or an operation completes, the I/O scheduler * looks for new operations to issue. * * All I/O classes have a fixed maximum number of outstanding operations * except for the async write class. Asynchronous writes represent the data * that is committed to stable storage during the syncing stage for * transaction groups (see txg.c). Transaction groups enter the syncing state * periodically so the number of queued async writes will quickly burst up and * then bleed down to zero. Rather than servicing them as quickly as possible, * the I/O scheduler changes the maximum number of active async write i/os * according to the amount of dirty data in the pool (see dsl_pool.c). Since * both throughput and latency typically increase with the number of * concurrent operations issued to physical devices, reducing the burstiness * in the number of concurrent operations also stabilizes the response time of * operations from other -- and in particular synchronous -- queues. In broad * strokes, the I/O scheduler will issue more concurrent operations from the * async write queue as there's more dirty data in the pool. * * Async Writes * * The number of concurrent operations issued for the async write I/O class * follows a piece-wise linear function defined by a few adjustable points. * * | o---------| <-- zfs_vdev_async_write_max_active * ^ | /^ | * | | / | | * active | / | | * I/O | / | | * count | / | | * | / | | * |------------o | | <-- zfs_vdev_async_write_min_active * 0|____________^______|_________| * 0% | | 100% of zfs_dirty_data_max * | | * | `-- zfs_vdev_async_write_active_max_dirty_percent * `--------- zfs_vdev_async_write_active_min_dirty_percent * * Until the amount of dirty data exceeds a minimum percentage of the dirty * data allowed in the pool, the I/O scheduler will limit the number of * concurrent operations to the minimum. As that threshold is crossed, the * number of concurrent operations issued increases linearly to the maximum at * the specified maximum percentage of the dirty data allowed in the pool. * * Ideally, the amount of dirty data on a busy pool will stay in the sloped * part of the function between zfs_vdev_async_write_active_min_dirty_percent * and zfs_vdev_async_write_active_max_dirty_percent. If it exceeds the * maximum percentage, this indicates that the rate of incoming data is * greater than the rate that the backend storage can handle. In this case, we * must further throttle incoming writes (see dmu_tx_delay() for details). */ /* * The maximum number of i/os active to each device. Ideally, this will be >= * the sum of each queue's max_active. */ uint32_t zfs_vdev_max_active = 1000; /* * Per-queue limits on the number of i/os active to each device. If the * number of active i/os is < zfs_vdev_max_active, then the min_active comes * into play. We will send min_active from each queue round-robin, and then * send from queues in the order defined by zio_priority_t up to max_active. * Some queues have additional mechanisms to limit number of active I/Os in * addition to min_active and max_active, see below. * * In general, smaller max_active's will lead to lower latency of synchronous * operations. Larger max_active's may lead to higher overall throughput, * depending on underlying storage. * * The ratio of the queues' max_actives determines the balance of performance * between reads, writes, and scrubs. E.g., increasing * zfs_vdev_scrub_max_active will cause the scrub or resilver to complete * more quickly, but reads and writes to have higher latency and lower * throughput. */ uint32_t zfs_vdev_sync_read_min_active = 10; uint32_t zfs_vdev_sync_read_max_active = 10; uint32_t zfs_vdev_sync_write_min_active = 10; uint32_t zfs_vdev_sync_write_max_active = 10; uint32_t zfs_vdev_async_read_min_active = 1; uint32_t zfs_vdev_async_read_max_active = 3; uint32_t zfs_vdev_async_write_min_active = 2; uint32_t zfs_vdev_async_write_max_active = 10; uint32_t zfs_vdev_scrub_min_active = 1; uint32_t zfs_vdev_scrub_max_active = 3; uint32_t zfs_vdev_removal_min_active = 1; uint32_t zfs_vdev_removal_max_active = 2; uint32_t zfs_vdev_initializing_min_active = 1; uint32_t zfs_vdev_initializing_max_active = 1; uint32_t zfs_vdev_trim_min_active = 1; uint32_t zfs_vdev_trim_max_active = 2; uint32_t zfs_vdev_rebuild_min_active = 1; uint32_t zfs_vdev_rebuild_max_active = 3; /* * When the pool has less than zfs_vdev_async_write_active_min_dirty_percent * dirty data, use zfs_vdev_async_write_min_active. When it has more than * zfs_vdev_async_write_active_max_dirty_percent, use * zfs_vdev_async_write_max_active. The value is linearly interpolated * between min and max. */ int zfs_vdev_async_write_active_min_dirty_percent = 30; int zfs_vdev_async_write_active_max_dirty_percent = 60; /* * For non-interactive I/O (scrub, resilver, removal, initialize and rebuild), * the number of concurrently-active I/O's is limited to *_min_active, unless * the vdev is "idle". When there are no interactive I/Os active (sync or * async), and zfs_vdev_nia_delay I/Os have completed since the last * interactive I/O, then the vdev is considered to be "idle", and the number * of concurrently-active non-interactive I/O's is increased to *_max_active. */ uint_t zfs_vdev_nia_delay = 5; /* * Some HDDs tend to prioritize sequential I/O so high that concurrent * random I/O latency reaches several seconds. On some HDDs it happens * even if sequential I/Os are submitted one at a time, and so setting * *_max_active to 1 does not help. To prevent non-interactive I/Os, like * scrub, from monopolizing the device no more than zfs_vdev_nia_credit * I/Os can be sent while there are outstanding incomplete interactive * I/Os. This enforced wait ensures the HDD services the interactive I/O * within a reasonable amount of time. */ uint_t zfs_vdev_nia_credit = 5; /* * To reduce IOPs, we aggregate small adjacent I/Os into one large I/O. * For read I/Os, we also aggregate across small adjacency gaps; for writes * we include spans of optional I/Os to aid aggregation at the disk even when * they aren't able to help us aggregate at this level. */ int zfs_vdev_aggregation_limit = 1 << 20; int zfs_vdev_aggregation_limit_non_rotating = SPA_OLD_MAXBLOCKSIZE; int zfs_vdev_read_gap_limit = 32 << 10; int zfs_vdev_write_gap_limit = 4 << 10; /* * Define the queue depth percentage for each top-level. This percentage is * used in conjunction with zfs_vdev_async_max_active to determine how many * allocations a specific top-level vdev should handle. Once the queue depth * reaches zfs_vdev_queue_depth_pct * zfs_vdev_async_write_max_active / 100 * then allocator will stop allocating blocks on that top-level device. * The default kernel setting is 1000% which will yield 100 allocations per * device. For userland testing, the default setting is 300% which equates * to 30 allocations per device. */ #ifdef _KERNEL int zfs_vdev_queue_depth_pct = 1000; #else int zfs_vdev_queue_depth_pct = 300; #endif /* * When performing allocations for a given metaslab, we want to make sure that * there are enough IOs to aggregate together to improve throughput. We want to * ensure that there are at least 128k worth of IOs that can be aggregated, and * we assume that the average allocation size is 4k, so we need the queue depth * to be 32 per allocator to get good aggregation of sequential writes. */ int zfs_vdev_def_queue_depth = 32; /* * Allow TRIM I/Os to be aggregated. This should normally not be needed since * TRIM I/O for extents up to zfs_trim_extent_bytes_max (128M) can be submitted * by the TRIM code in zfs_trim.c. */ int zfs_vdev_aggregate_trim = 0; static int vdev_queue_offset_compare(const void *x1, const void *x2) { const zio_t *z1 = (const zio_t *)x1; const zio_t *z2 = (const zio_t *)x2; int cmp = TREE_CMP(z1->io_offset, z2->io_offset); if (likely(cmp)) return (cmp); return (TREE_PCMP(z1, z2)); } static inline avl_tree_t * vdev_queue_class_tree(vdev_queue_t *vq, zio_priority_t p) { return (&vq->vq_class[p].vqc_queued_tree); } static inline avl_tree_t * vdev_queue_type_tree(vdev_queue_t *vq, zio_type_t t) { ASSERT(t == ZIO_TYPE_READ || t == ZIO_TYPE_WRITE || t == ZIO_TYPE_TRIM); if (t == ZIO_TYPE_READ) return (&vq->vq_read_offset_tree); else if (t == ZIO_TYPE_WRITE) return (&vq->vq_write_offset_tree); else return (&vq->vq_trim_offset_tree); } static int vdev_queue_timestamp_compare(const void *x1, const void *x2) { const zio_t *z1 = (const zio_t *)x1; const zio_t *z2 = (const zio_t *)x2; int cmp = TREE_CMP(z1->io_timestamp, z2->io_timestamp); if (likely(cmp)) return (cmp); return (TREE_PCMP(z1, z2)); } static int vdev_queue_class_min_active(vdev_queue_t *vq, zio_priority_t p) { switch (p) { case ZIO_PRIORITY_SYNC_READ: return (zfs_vdev_sync_read_min_active); case ZIO_PRIORITY_SYNC_WRITE: return (zfs_vdev_sync_write_min_active); case ZIO_PRIORITY_ASYNC_READ: return (zfs_vdev_async_read_min_active); case ZIO_PRIORITY_ASYNC_WRITE: return (zfs_vdev_async_write_min_active); case ZIO_PRIORITY_SCRUB: return (vq->vq_ia_active == 0 ? zfs_vdev_scrub_min_active : MIN(vq->vq_nia_credit, zfs_vdev_scrub_min_active)); case ZIO_PRIORITY_REMOVAL: return (vq->vq_ia_active == 0 ? zfs_vdev_removal_min_active : MIN(vq->vq_nia_credit, zfs_vdev_removal_min_active)); case ZIO_PRIORITY_INITIALIZING: return (vq->vq_ia_active == 0 ?zfs_vdev_initializing_min_active: MIN(vq->vq_nia_credit, zfs_vdev_initializing_min_active)); case ZIO_PRIORITY_TRIM: return (zfs_vdev_trim_min_active); case ZIO_PRIORITY_REBUILD: return (vq->vq_ia_active == 0 ? zfs_vdev_rebuild_min_active : MIN(vq->vq_nia_credit, zfs_vdev_rebuild_min_active)); default: panic("invalid priority %u", p); return (0); } } static int vdev_queue_max_async_writes(spa_t *spa) { int writes; uint64_t dirty = 0; dsl_pool_t *dp = spa_get_dsl(spa); uint64_t min_bytes = zfs_dirty_data_max * zfs_vdev_async_write_active_min_dirty_percent / 100; uint64_t max_bytes = zfs_dirty_data_max * zfs_vdev_async_write_active_max_dirty_percent / 100; /* * Async writes may occur before the assignment of the spa's * dsl_pool_t if a self-healing zio is issued prior to the * completion of dmu_objset_open_impl(). */ if (dp == NULL) return (zfs_vdev_async_write_max_active); /* * Sync tasks correspond to interactive user actions. To reduce the * execution time of those actions we push data out as fast as possible. */ dirty = dp->dp_dirty_total; if (dirty > max_bytes || spa_has_pending_synctask(spa)) return (zfs_vdev_async_write_max_active); if (dirty < min_bytes) return (zfs_vdev_async_write_min_active); /* * linear interpolation: * slope = (max_writes - min_writes) / (max_bytes - min_bytes) * move right by min_bytes * move up by min_writes */ writes = (dirty - min_bytes) * (zfs_vdev_async_write_max_active - zfs_vdev_async_write_min_active) / (max_bytes - min_bytes) + zfs_vdev_async_write_min_active; ASSERT3U(writes, >=, zfs_vdev_async_write_min_active); ASSERT3U(writes, <=, zfs_vdev_async_write_max_active); return (writes); } static int vdev_queue_class_max_active(spa_t *spa, vdev_queue_t *vq, zio_priority_t p) { switch (p) { case ZIO_PRIORITY_SYNC_READ: return (zfs_vdev_sync_read_max_active); case ZIO_PRIORITY_SYNC_WRITE: return (zfs_vdev_sync_write_max_active); case ZIO_PRIORITY_ASYNC_READ: return (zfs_vdev_async_read_max_active); case ZIO_PRIORITY_ASYNC_WRITE: return (vdev_queue_max_async_writes(spa)); case ZIO_PRIORITY_SCRUB: if (vq->vq_ia_active > 0) { return (MIN(vq->vq_nia_credit, zfs_vdev_scrub_min_active)); } else if (vq->vq_nia_credit < zfs_vdev_nia_delay) return (MAX(1, zfs_vdev_scrub_min_active)); return (zfs_vdev_scrub_max_active); case ZIO_PRIORITY_REMOVAL: if (vq->vq_ia_active > 0) { return (MIN(vq->vq_nia_credit, zfs_vdev_removal_min_active)); } else if (vq->vq_nia_credit < zfs_vdev_nia_delay) return (MAX(1, zfs_vdev_removal_min_active)); return (zfs_vdev_removal_max_active); case ZIO_PRIORITY_INITIALIZING: if (vq->vq_ia_active > 0) { return (MIN(vq->vq_nia_credit, zfs_vdev_initializing_min_active)); } else if (vq->vq_nia_credit < zfs_vdev_nia_delay) return (MAX(1, zfs_vdev_initializing_min_active)); return (zfs_vdev_initializing_max_active); case ZIO_PRIORITY_TRIM: return (zfs_vdev_trim_max_active); case ZIO_PRIORITY_REBUILD: if (vq->vq_ia_active > 0) { return (MIN(vq->vq_nia_credit, zfs_vdev_rebuild_min_active)); } else if (vq->vq_nia_credit < zfs_vdev_nia_delay) return (MAX(1, zfs_vdev_rebuild_min_active)); return (zfs_vdev_rebuild_max_active); default: panic("invalid priority %u", p); return (0); } } /* * Return the i/o class to issue from, or ZIO_PRIORITY_MAX_QUEUEABLE if * there is no eligible class. */ static zio_priority_t vdev_queue_class_to_issue(vdev_queue_t *vq) { spa_t *spa = vq->vq_vdev->vdev_spa; zio_priority_t p, n; if (avl_numnodes(&vq->vq_active_tree) >= zfs_vdev_max_active) return (ZIO_PRIORITY_NUM_QUEUEABLE); /* * Find a queue that has not reached its minimum # outstanding i/os. * Do round-robin to reduce starvation due to zfs_vdev_max_active * and vq_nia_credit limits. */ for (n = 0; n < ZIO_PRIORITY_NUM_QUEUEABLE; n++) { p = (vq->vq_last_prio + n + 1) % ZIO_PRIORITY_NUM_QUEUEABLE; if (avl_numnodes(vdev_queue_class_tree(vq, p)) > 0 && vq->vq_class[p].vqc_active < vdev_queue_class_min_active(vq, p)) { vq->vq_last_prio = p; return (p); } } /* * If we haven't found a queue, look for one that hasn't reached its * maximum # outstanding i/os. */ for (p = 0; p < ZIO_PRIORITY_NUM_QUEUEABLE; p++) { if (avl_numnodes(vdev_queue_class_tree(vq, p)) > 0 && vq->vq_class[p].vqc_active < vdev_queue_class_max_active(spa, vq, p)) { vq->vq_last_prio = p; return (p); } } /* No eligible queued i/os */ return (ZIO_PRIORITY_NUM_QUEUEABLE); } void vdev_queue_init(vdev_t *vd) { vdev_queue_t *vq = &vd->vdev_queue; zio_priority_t p; mutex_init(&vq->vq_lock, NULL, MUTEX_DEFAULT, NULL); vq->vq_vdev = vd; taskq_init_ent(&vd->vdev_queue.vq_io_search.io_tqent); avl_create(&vq->vq_active_tree, vdev_queue_offset_compare, sizeof (zio_t), offsetof(struct zio, io_queue_node)); avl_create(vdev_queue_type_tree(vq, ZIO_TYPE_READ), vdev_queue_offset_compare, sizeof (zio_t), offsetof(struct zio, io_offset_node)); avl_create(vdev_queue_type_tree(vq, ZIO_TYPE_WRITE), vdev_queue_offset_compare, sizeof (zio_t), offsetof(struct zio, io_offset_node)); avl_create(vdev_queue_type_tree(vq, ZIO_TYPE_TRIM), vdev_queue_offset_compare, sizeof (zio_t), offsetof(struct zio, io_offset_node)); for (p = 0; p < ZIO_PRIORITY_NUM_QUEUEABLE; p++) { int (*compfn) (const void *, const void *); /* * The synchronous/trim i/o queues are dispatched in FIFO rather * than LBA order. This provides more consistent latency for * these i/os. */ if (p == ZIO_PRIORITY_SYNC_READ || p == ZIO_PRIORITY_SYNC_WRITE || p == ZIO_PRIORITY_TRIM) { compfn = vdev_queue_timestamp_compare; } else { compfn = vdev_queue_offset_compare; } avl_create(vdev_queue_class_tree(vq, p), compfn, sizeof (zio_t), offsetof(struct zio, io_queue_node)); } vq->vq_last_offset = 0; } void vdev_queue_fini(vdev_t *vd) { vdev_queue_t *vq = &vd->vdev_queue; for (zio_priority_t p = 0; p < ZIO_PRIORITY_NUM_QUEUEABLE; p++) avl_destroy(vdev_queue_class_tree(vq, p)); avl_destroy(&vq->vq_active_tree); avl_destroy(vdev_queue_type_tree(vq, ZIO_TYPE_READ)); avl_destroy(vdev_queue_type_tree(vq, ZIO_TYPE_WRITE)); avl_destroy(vdev_queue_type_tree(vq, ZIO_TYPE_TRIM)); mutex_destroy(&vq->vq_lock); } static void vdev_queue_io_add(vdev_queue_t *vq, zio_t *zio) { spa_t *spa = zio->io_spa; spa_history_kstat_t *shk = &spa->spa_stats.io_history; ASSERT3U(zio->io_priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); avl_add(vdev_queue_class_tree(vq, zio->io_priority), zio); avl_add(vdev_queue_type_tree(vq, zio->io_type), zio); if (shk->kstat != NULL) { mutex_enter(&shk->lock); kstat_waitq_enter(shk->kstat->ks_data); mutex_exit(&shk->lock); } } static void vdev_queue_io_remove(vdev_queue_t *vq, zio_t *zio) { spa_t *spa = zio->io_spa; spa_history_kstat_t *shk = &spa->spa_stats.io_history; ASSERT3U(zio->io_priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); avl_remove(vdev_queue_class_tree(vq, zio->io_priority), zio); avl_remove(vdev_queue_type_tree(vq, zio->io_type), zio); if (shk->kstat != NULL) { mutex_enter(&shk->lock); kstat_waitq_exit(shk->kstat->ks_data); mutex_exit(&shk->lock); } } static boolean_t vdev_queue_is_interactive(zio_priority_t p) { switch (p) { case ZIO_PRIORITY_SCRUB: case ZIO_PRIORITY_REMOVAL: case ZIO_PRIORITY_INITIALIZING: case ZIO_PRIORITY_REBUILD: return (B_FALSE); default: return (B_TRUE); } } static void vdev_queue_pending_add(vdev_queue_t *vq, zio_t *zio) { spa_t *spa = zio->io_spa; spa_history_kstat_t *shk = &spa->spa_stats.io_history; ASSERT(MUTEX_HELD(&vq->vq_lock)); ASSERT3U(zio->io_priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); vq->vq_class[zio->io_priority].vqc_active++; if (vdev_queue_is_interactive(zio->io_priority)) { if (++vq->vq_ia_active == 1) vq->vq_nia_credit = 1; } else if (vq->vq_ia_active > 0) { vq->vq_nia_credit--; } avl_add(&vq->vq_active_tree, zio); if (shk->kstat != NULL) { mutex_enter(&shk->lock); kstat_runq_enter(shk->kstat->ks_data); mutex_exit(&shk->lock); } } static void vdev_queue_pending_remove(vdev_queue_t *vq, zio_t *zio) { spa_t *spa = zio->io_spa; spa_history_kstat_t *shk = &spa->spa_stats.io_history; ASSERT(MUTEX_HELD(&vq->vq_lock)); ASSERT3U(zio->io_priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); vq->vq_class[zio->io_priority].vqc_active--; if (vdev_queue_is_interactive(zio->io_priority)) { if (--vq->vq_ia_active == 0) vq->vq_nia_credit = 0; else vq->vq_nia_credit = zfs_vdev_nia_credit; } else if (vq->vq_ia_active == 0) vq->vq_nia_credit++; avl_remove(&vq->vq_active_tree, zio); if (shk->kstat != NULL) { kstat_io_t *ksio = shk->kstat->ks_data; mutex_enter(&shk->lock); kstat_runq_exit(ksio); if (zio->io_type == ZIO_TYPE_READ) { ksio->reads++; ksio->nread += zio->io_size; } else if (zio->io_type == ZIO_TYPE_WRITE) { ksio->writes++; ksio->nwritten += zio->io_size; } mutex_exit(&shk->lock); } } static void vdev_queue_agg_io_done(zio_t *aio) { abd_free(aio->io_abd); } /* * Compute the range spanned by two i/os, which is the endpoint of the last * (lio->io_offset + lio->io_size) minus start of the first (fio->io_offset). * Conveniently, the gap between fio and lio is given by -IO_SPAN(lio, fio); * thus fio and lio are adjacent if and only if IO_SPAN(lio, fio) == 0. */ #define IO_SPAN(fio, lio) ((lio)->io_offset + (lio)->io_size - (fio)->io_offset) #define IO_GAP(fio, lio) (-IO_SPAN(lio, fio)) /* * Sufficiently adjacent io_offset's in ZIOs will be aggregated. We do this * by creating a gang ABD from the adjacent ZIOs io_abd's. By using * a gang ABD we avoid doing memory copies to and from the parent, * child ZIOs. The gang ABD also accounts for gaps between adjacent * io_offsets by simply getting the zero ABD for writes or allocating * a new ABD for reads and placing them in the gang ABD as well. */ static zio_t * vdev_queue_aggregate(vdev_queue_t *vq, zio_t *zio) { zio_t *first, *last, *aio, *dio, *mandatory, *nio; zio_link_t *zl = NULL; uint64_t maxgap = 0; uint64_t size; uint64_t limit; int maxblocksize; boolean_t stretch = B_FALSE; avl_tree_t *t = vdev_queue_type_tree(vq, zio->io_type); enum zio_flag flags = zio->io_flags & ZIO_FLAG_AGG_INHERIT; uint64_t next_offset; abd_t *abd; maxblocksize = spa_maxblocksize(vq->vq_vdev->vdev_spa); if (vq->vq_vdev->vdev_nonrot) limit = zfs_vdev_aggregation_limit_non_rotating; else limit = zfs_vdev_aggregation_limit; limit = MAX(MIN(limit, maxblocksize), 0); if (zio->io_flags & ZIO_FLAG_DONT_AGGREGATE || limit == 0) return (NULL); /* * While TRIM commands could be aggregated based on offset this * behavior is disabled until it's determined to be beneficial. */ if (zio->io_type == ZIO_TYPE_TRIM && !zfs_vdev_aggregate_trim) return (NULL); /* * I/Os to distributed spares are directly dispatched to the dRAID * leaf vdevs for aggregation. See the comment at the end of the * zio_vdev_io_start() function. */ ASSERT(vq->vq_vdev->vdev_ops != &vdev_draid_spare_ops); first = last = zio; if (zio->io_type == ZIO_TYPE_READ) maxgap = zfs_vdev_read_gap_limit; /* * We can aggregate I/Os that are sufficiently adjacent and of * the same flavor, as expressed by the AGG_INHERIT flags. * The latter requirement is necessary so that certain * attributes of the I/O, such as whether it's a normal I/O * or a scrub/resilver, can be preserved in the aggregate. * We can include optional I/Os, but don't allow them * to begin a range as they add no benefit in that situation. */ /* * We keep track of the last non-optional I/O. */ mandatory = (first->io_flags & ZIO_FLAG_OPTIONAL) ? NULL : first; /* * Walk backwards through sufficiently contiguous I/Os * recording the last non-optional I/O. */ while ((dio = AVL_PREV(t, first)) != NULL && (dio->io_flags & ZIO_FLAG_AGG_INHERIT) == flags && IO_SPAN(dio, last) <= limit && IO_GAP(dio, first) <= maxgap && dio->io_type == zio->io_type) { first = dio; if (mandatory == NULL && !(first->io_flags & ZIO_FLAG_OPTIONAL)) mandatory = first; } /* * Skip any initial optional I/Os. */ while ((first->io_flags & ZIO_FLAG_OPTIONAL) && first != last) { first = AVL_NEXT(t, first); ASSERT(first != NULL); } /* * Walk forward through sufficiently contiguous I/Os. * The aggregation limit does not apply to optional i/os, so that * we can issue contiguous writes even if they are larger than the * aggregation limit. */ while ((dio = AVL_NEXT(t, last)) != NULL && (dio->io_flags & ZIO_FLAG_AGG_INHERIT) == flags && (IO_SPAN(first, dio) <= limit || (dio->io_flags & ZIO_FLAG_OPTIONAL)) && IO_SPAN(first, dio) <= maxblocksize && IO_GAP(last, dio) <= maxgap && dio->io_type == zio->io_type) { last = dio; if (!(last->io_flags & ZIO_FLAG_OPTIONAL)) mandatory = last; } /* * Now that we've established the range of the I/O aggregation * we must decide what to do with trailing optional I/Os. * For reads, there's nothing to do. While we are unable to * aggregate further, it's possible that a trailing optional * I/O would allow the underlying device to aggregate with * subsequent I/Os. We must therefore determine if the next * non-optional I/O is close enough to make aggregation * worthwhile. */ if (zio->io_type == ZIO_TYPE_WRITE && mandatory != NULL) { zio_t *nio = last; while ((dio = AVL_NEXT(t, nio)) != NULL && IO_GAP(nio, dio) == 0 && IO_GAP(mandatory, dio) <= zfs_vdev_write_gap_limit) { nio = dio; if (!(nio->io_flags & ZIO_FLAG_OPTIONAL)) { stretch = B_TRUE; break; } } } if (stretch) { /* * We are going to include an optional io in our aggregated * span, thus closing the write gap. Only mandatory i/os can * start aggregated spans, so make sure that the next i/o * after our span is mandatory. */ dio = AVL_NEXT(t, last); dio->io_flags &= ~ZIO_FLAG_OPTIONAL; } else { /* do not include the optional i/o */ while (last != mandatory && last != first) { ASSERT(last->io_flags & ZIO_FLAG_OPTIONAL); last = AVL_PREV(t, last); ASSERT(last != NULL); } } if (first == last) return (NULL); size = IO_SPAN(first, last); ASSERT3U(size, <=, maxblocksize); - abd = abd_alloc_gang_abd(); + abd = abd_alloc_gang(); if (abd == NULL) return (NULL); aio = zio_vdev_delegated_io(first->io_vd, first->io_offset, abd, size, first->io_type, zio->io_priority, flags | ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_QUEUE, vdev_queue_agg_io_done, NULL); aio->io_timestamp = first->io_timestamp; nio = first; next_offset = first->io_offset; do { dio = nio; nio = AVL_NEXT(t, dio); zio_add_child(dio, aio); vdev_queue_io_remove(vq, dio); if (dio->io_offset != next_offset) { /* allocate a buffer for a read gap */ ASSERT3U(dio->io_type, ==, ZIO_TYPE_READ); ASSERT3U(dio->io_offset, >, next_offset); abd = abd_alloc_for_io( dio->io_offset - next_offset, B_TRUE); abd_gang_add(aio->io_abd, abd, B_TRUE); } if (dio->io_abd && (dio->io_size != abd_get_size(dio->io_abd))) { /* abd size not the same as IO size */ ASSERT3U(abd_get_size(dio->io_abd), >, dio->io_size); abd = abd_get_offset_size(dio->io_abd, 0, dio->io_size); abd_gang_add(aio->io_abd, abd, B_TRUE); } else { if (dio->io_flags & ZIO_FLAG_NODATA) { /* allocate a buffer for a write gap */ ASSERT3U(dio->io_type, ==, ZIO_TYPE_WRITE); ASSERT3P(dio->io_abd, ==, NULL); abd_gang_add(aio->io_abd, abd_get_zeros(dio->io_size), B_TRUE); } else { /* * We pass B_FALSE to abd_gang_add() * because we did not allocate a new * ABD, so it is assumed the caller * will free this ABD. */ abd_gang_add(aio->io_abd, dio->io_abd, B_FALSE); } } next_offset = dio->io_offset + dio->io_size; } while (dio != last); ASSERT3U(abd_get_size(aio->io_abd), ==, aio->io_size); /* * We need to drop the vdev queue's lock during zio_execute() to * avoid a deadlock that we could encounter due to lock order * reversal between vq_lock and io_lock in zio_change_priority(). */ mutex_exit(&vq->vq_lock); while ((dio = zio_walk_parents(aio, &zl)) != NULL) { ASSERT3U(dio->io_type, ==, aio->io_type); zio_vdev_io_bypass(dio); zio_execute(dio); } mutex_enter(&vq->vq_lock); return (aio); } static zio_t * vdev_queue_io_to_issue(vdev_queue_t *vq) { zio_t *zio, *aio; zio_priority_t p; avl_index_t idx; avl_tree_t *tree; again: ASSERT(MUTEX_HELD(&vq->vq_lock)); p = vdev_queue_class_to_issue(vq); if (p == ZIO_PRIORITY_NUM_QUEUEABLE) { /* No eligible queued i/os */ return (NULL); } /* * For LBA-ordered queues (async / scrub / initializing), issue the * i/o which follows the most recently issued i/o in LBA (offset) order. * * For FIFO queues (sync/trim), issue the i/o with the lowest timestamp. */ tree = vdev_queue_class_tree(vq, p); vq->vq_io_search.io_timestamp = 0; vq->vq_io_search.io_offset = vq->vq_last_offset - 1; VERIFY3P(avl_find(tree, &vq->vq_io_search, &idx), ==, NULL); zio = avl_nearest(tree, idx, AVL_AFTER); if (zio == NULL) zio = avl_first(tree); ASSERT3U(zio->io_priority, ==, p); aio = vdev_queue_aggregate(vq, zio); if (aio != NULL) zio = aio; else vdev_queue_io_remove(vq, zio); /* * If the I/O is or was optional and therefore has no data, we need to * simply discard it. We need to drop the vdev queue's lock to avoid a * deadlock that we could encounter since this I/O will complete * immediately. */ if (zio->io_flags & ZIO_FLAG_NODATA) { mutex_exit(&vq->vq_lock); zio_vdev_io_bypass(zio); zio_execute(zio); mutex_enter(&vq->vq_lock); goto again; } vdev_queue_pending_add(vq, zio); vq->vq_last_offset = zio->io_offset + zio->io_size; return (zio); } zio_t * vdev_queue_io(zio_t *zio) { vdev_queue_t *vq = &zio->io_vd->vdev_queue; zio_t *nio; if (zio->io_flags & ZIO_FLAG_DONT_QUEUE) return (zio); /* * Children i/os inherent their parent's priority, which might * not match the child's i/o type. Fix it up here. */ if (zio->io_type == ZIO_TYPE_READ) { ASSERT(zio->io_priority != ZIO_PRIORITY_TRIM); if (zio->io_priority != ZIO_PRIORITY_SYNC_READ && zio->io_priority != ZIO_PRIORITY_ASYNC_READ && zio->io_priority != ZIO_PRIORITY_SCRUB && zio->io_priority != ZIO_PRIORITY_REMOVAL && zio->io_priority != ZIO_PRIORITY_INITIALIZING && zio->io_priority != ZIO_PRIORITY_REBUILD) { zio->io_priority = ZIO_PRIORITY_ASYNC_READ; } } else if (zio->io_type == ZIO_TYPE_WRITE) { ASSERT(zio->io_priority != ZIO_PRIORITY_TRIM); if (zio->io_priority != ZIO_PRIORITY_SYNC_WRITE && zio->io_priority != ZIO_PRIORITY_ASYNC_WRITE && zio->io_priority != ZIO_PRIORITY_REMOVAL && zio->io_priority != ZIO_PRIORITY_INITIALIZING && zio->io_priority != ZIO_PRIORITY_REBUILD) { zio->io_priority = ZIO_PRIORITY_ASYNC_WRITE; } } else { ASSERT(zio->io_type == ZIO_TYPE_TRIM); ASSERT(zio->io_priority == ZIO_PRIORITY_TRIM); } zio->io_flags |= ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_QUEUE; mutex_enter(&vq->vq_lock); zio->io_timestamp = gethrtime(); vdev_queue_io_add(vq, zio); nio = vdev_queue_io_to_issue(vq); mutex_exit(&vq->vq_lock); if (nio == NULL) return (NULL); if (nio->io_done == vdev_queue_agg_io_done) { zio_nowait(nio); return (NULL); } return (nio); } void vdev_queue_io_done(zio_t *zio) { vdev_queue_t *vq = &zio->io_vd->vdev_queue; zio_t *nio; mutex_enter(&vq->vq_lock); vdev_queue_pending_remove(vq, zio); zio->io_delta = gethrtime() - zio->io_timestamp; vq->vq_io_complete_ts = gethrtime(); vq->vq_io_delta_ts = vq->vq_io_complete_ts - zio->io_timestamp; while ((nio = vdev_queue_io_to_issue(vq)) != NULL) { mutex_exit(&vq->vq_lock); if (nio->io_done == vdev_queue_agg_io_done) { zio_nowait(nio); } else { zio_vdev_io_reissue(nio); zio_execute(nio); } mutex_enter(&vq->vq_lock); } mutex_exit(&vq->vq_lock); } void vdev_queue_change_io_priority(zio_t *zio, zio_priority_t priority) { vdev_queue_t *vq = &zio->io_vd->vdev_queue; avl_tree_t *tree; /* * ZIO_PRIORITY_NOW is used by the vdev cache code and the aggregate zio * code to issue IOs without adding them to the vdev queue. In this * case, the zio is already going to be issued as quickly as possible * and so it doesn't need any reprioritization to help. */ if (zio->io_priority == ZIO_PRIORITY_NOW) return; ASSERT3U(zio->io_priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); ASSERT3U(priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); if (zio->io_type == ZIO_TYPE_READ) { if (priority != ZIO_PRIORITY_SYNC_READ && priority != ZIO_PRIORITY_ASYNC_READ && priority != ZIO_PRIORITY_SCRUB) priority = ZIO_PRIORITY_ASYNC_READ; } else { ASSERT(zio->io_type == ZIO_TYPE_WRITE); if (priority != ZIO_PRIORITY_SYNC_WRITE && priority != ZIO_PRIORITY_ASYNC_WRITE) priority = ZIO_PRIORITY_ASYNC_WRITE; } mutex_enter(&vq->vq_lock); /* * If the zio is in none of the queues we can simply change * the priority. If the zio is waiting to be submitted we must * remove it from the queue and re-insert it with the new priority. * Otherwise, the zio is currently active and we cannot change its * priority. */ tree = vdev_queue_class_tree(vq, zio->io_priority); if (avl_find(tree, zio, NULL) == zio) { avl_remove(vdev_queue_class_tree(vq, zio->io_priority), zio); zio->io_priority = priority; avl_add(vdev_queue_class_tree(vq, zio->io_priority), zio); } else if (avl_find(&vq->vq_active_tree, zio, NULL) != zio) { zio->io_priority = priority; } mutex_exit(&vq->vq_lock); } /* * As these two methods are only used for load calculations we're not * concerned if we get an incorrect value on 32bit platforms due to lack of * vq_lock mutex use here, instead we prefer to keep it lock free for * performance. */ int vdev_queue_length(vdev_t *vd) { return (avl_numnodes(&vd->vdev_queue.vq_active_tree)); } uint64_t vdev_queue_last_offset(vdev_t *vd) { return (vd->vdev_queue.vq_last_offset); } /* BEGIN CSTYLED */ ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, aggregation_limit, INT, ZMOD_RW, "Max vdev I/O aggregation size"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, aggregation_limit_non_rotating, INT, ZMOD_RW, "Max vdev I/O aggregation size for non-rotating media"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, aggregate_trim, INT, ZMOD_RW, "Allow TRIM I/O to be aggregated"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, read_gap_limit, INT, ZMOD_RW, "Aggregate read I/O over gap"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, write_gap_limit, INT, ZMOD_RW, "Aggregate write I/O over gap"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, max_active, INT, ZMOD_RW, "Maximum number of active I/Os per vdev"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, async_write_active_max_dirty_percent, INT, ZMOD_RW, "Async write concurrency max threshold"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, async_write_active_min_dirty_percent, INT, ZMOD_RW, "Async write concurrency min threshold"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, async_read_max_active, INT, ZMOD_RW, "Max active async read I/Os per vdev"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, async_read_min_active, INT, ZMOD_RW, "Min active async read I/Os per vdev"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, async_write_max_active, INT, ZMOD_RW, "Max active async write I/Os per vdev"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, async_write_min_active, INT, ZMOD_RW, "Min active async write I/Os per vdev"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, initializing_max_active, INT, ZMOD_RW, "Max active initializing I/Os per vdev"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, initializing_min_active, INT, ZMOD_RW, "Min active initializing I/Os per vdev"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, removal_max_active, INT, ZMOD_RW, "Max active removal I/Os per vdev"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, removal_min_active, INT, ZMOD_RW, "Min active removal I/Os per vdev"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, scrub_max_active, INT, ZMOD_RW, "Max active scrub I/Os per vdev"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, scrub_min_active, INT, ZMOD_RW, "Min active scrub I/Os per vdev"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, sync_read_max_active, INT, ZMOD_RW, "Max active sync read I/Os per vdev"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, sync_read_min_active, INT, ZMOD_RW, "Min active sync read I/Os per vdev"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, sync_write_max_active, INT, ZMOD_RW, "Max active sync write I/Os per vdev"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, sync_write_min_active, INT, ZMOD_RW, "Min active sync write I/Os per vdev"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, trim_max_active, INT, ZMOD_RW, "Max active trim/discard I/Os per vdev"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, trim_min_active, INT, ZMOD_RW, "Min active trim/discard I/Os per vdev"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, rebuild_max_active, INT, ZMOD_RW, "Max active rebuild I/Os per vdev"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, rebuild_min_active, INT, ZMOD_RW, "Min active rebuild I/Os per vdev"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, nia_credit, INT, ZMOD_RW, "Number of non-interactive I/Os to allow in sequence"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, nia_delay, INT, ZMOD_RW, "Number of non-interactive I/Os before _max_active"); ZFS_MODULE_PARAM(zfs_vdev, zfs_vdev_, queue_depth_pct, INT, ZMOD_RW, "Queue depth percentage for each top-level vdev"); /* END CSTYLED */ diff --git a/module/zfs/vdev_raidz.c b/module/zfs/vdev_raidz.c index 989b90dc2635..07934cdff20b 100644 --- a/module/zfs/vdev_raidz.c +++ b/module/zfs/vdev_raidz.c @@ -1,2776 +1,2757 @@ /* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. * Copyright (c) 2012, 2020 by Delphix. All rights reserved. * Copyright (c) 2016 Gvozden Nešković. All rights reserved. */ #include #include #include #include #include #include #include #include #include #include #include #ifdef ZFS_DEBUG #include /* For vdev_xlate() in vdev_raidz_io_verify() */ #endif /* * Virtual device vector for RAID-Z. * * This vdev supports single, double, and triple parity. For single parity, * we use a simple XOR of all the data columns. For double or triple parity, * we use a special case of Reed-Solomon coding. This extends the * technique described in "The mathematics of RAID-6" by H. Peter Anvin by * drawing on the system described in "A Tutorial on Reed-Solomon Coding for * Fault-Tolerance in RAID-like Systems" by James S. Plank on which the * former is also based. The latter is designed to provide higher performance * for writes. * * Note that the Plank paper claimed to support arbitrary N+M, but was then * amended six years later identifying a critical flaw that invalidates its * claims. Nevertheless, the technique can be adapted to work for up to * triple parity. For additional parity, the amendment "Note: Correction to * the 1997 Tutorial on Reed-Solomon Coding" by James S. Plank and Ying Ding * is viable, but the additional complexity means that write performance will * suffer. * * All of the methods above operate on a Galois field, defined over the * integers mod 2^N. In our case we choose N=8 for GF(8) so that all elements * can be expressed with a single byte. Briefly, the operations on the * field are defined as follows: * * o addition (+) is represented by a bitwise XOR * o subtraction (-) is therefore identical to addition: A + B = A - B * o multiplication of A by 2 is defined by the following bitwise expression: * * (A * 2)_7 = A_6 * (A * 2)_6 = A_5 * (A * 2)_5 = A_4 * (A * 2)_4 = A_3 + A_7 * (A * 2)_3 = A_2 + A_7 * (A * 2)_2 = A_1 + A_7 * (A * 2)_1 = A_0 * (A * 2)_0 = A_7 * * In C, multiplying by 2 is therefore ((a << 1) ^ ((a & 0x80) ? 0x1d : 0)). * As an aside, this multiplication is derived from the error correcting * primitive polynomial x^8 + x^4 + x^3 + x^2 + 1. * * Observe that any number in the field (except for 0) can be expressed as a * power of 2 -- a generator for the field. We store a table of the powers of * 2 and logs base 2 for quick look ups, and exploit the fact that A * B can * be rewritten as 2^(log_2(A) + log_2(B)) (where '+' is normal addition rather * than field addition). The inverse of a field element A (A^-1) is therefore * A ^ (255 - 1) = A^254. * * The up-to-three parity columns, P, Q, R over several data columns, * D_0, ... D_n-1, can be expressed by field operations: * * P = D_0 + D_1 + ... + D_n-2 + D_n-1 * Q = 2^n-1 * D_0 + 2^n-2 * D_1 + ... + 2^1 * D_n-2 + 2^0 * D_n-1 * = ((...((D_0) * 2 + D_1) * 2 + ...) * 2 + D_n-2) * 2 + D_n-1 * R = 4^n-1 * D_0 + 4^n-2 * D_1 + ... + 4^1 * D_n-2 + 4^0 * D_n-1 * = ((...((D_0) * 4 + D_1) * 4 + ...) * 4 + D_n-2) * 4 + D_n-1 * * We chose 1, 2, and 4 as our generators because 1 corresponds to the trivial * XOR operation, and 2 and 4 can be computed quickly and generate linearly- * independent coefficients. (There are no additional coefficients that have * this property which is why the uncorrected Plank method breaks down.) * * See the reconstruction code below for how P, Q and R can used individually * or in concert to recover missing data columns. */ #define VDEV_RAIDZ_P 0 #define VDEV_RAIDZ_Q 1 #define VDEV_RAIDZ_R 2 #define VDEV_RAIDZ_MUL_2(x) (((x) << 1) ^ (((x) & 0x80) ? 0x1d : 0)) #define VDEV_RAIDZ_MUL_4(x) (VDEV_RAIDZ_MUL_2(VDEV_RAIDZ_MUL_2(x))) /* * We provide a mechanism to perform the field multiplication operation on a * 64-bit value all at once rather than a byte at a time. This works by * creating a mask from the top bit in each byte and using that to * conditionally apply the XOR of 0x1d. */ #define VDEV_RAIDZ_64MUL_2(x, mask) \ { \ (mask) = (x) & 0x8080808080808080ULL; \ (mask) = ((mask) << 1) - ((mask) >> 7); \ (x) = (((x) << 1) & 0xfefefefefefefefeULL) ^ \ ((mask) & 0x1d1d1d1d1d1d1d1dULL); \ } #define VDEV_RAIDZ_64MUL_4(x, mask) \ { \ VDEV_RAIDZ_64MUL_2((x), mask); \ VDEV_RAIDZ_64MUL_2((x), mask); \ } static void vdev_raidz_row_free(raidz_row_t *rr) { - int c; - - for (c = 0; c < rr->rr_firstdatacol && c < rr->rr_cols; c++) { - abd_free(rr->rr_col[c].rc_abd); + for (int c = 0; c < rr->rr_cols; c++) { + raidz_col_t *rc = &rr->rr_col[c]; - if (rr->rr_col[c].rc_gdata != NULL) { - abd_free(rr->rr_col[c].rc_gdata); - } - if (rr->rr_col[c].rc_orig_data != NULL) { - zio_buf_free(rr->rr_col[c].rc_orig_data, - rr->rr_col[c].rc_size); - } - } - for (c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { - if (rr->rr_col[c].rc_size != 0) { - if (abd_is_gang(rr->rr_col[c].rc_abd)) - abd_free(rr->rr_col[c].rc_abd); - else - abd_put(rr->rr_col[c].rc_abd); - } - if (rr->rr_col[c].rc_orig_data != NULL) { - zio_buf_free(rr->rr_col[c].rc_orig_data, - rr->rr_col[c].rc_size); - } + if (rc->rc_size != 0) + abd_free(rc->rc_abd); + if (rc->rc_gdata != NULL) + abd_free(rc->rc_gdata); + if (rc->rc_orig_data != NULL) + zio_buf_free(rc->rc_orig_data, rc->rc_size); } if (rr->rr_abd_copy != NULL) abd_free(rr->rr_abd_copy); if (rr->rr_abd_empty != NULL) abd_free(rr->rr_abd_empty); kmem_free(rr, offsetof(raidz_row_t, rr_col[rr->rr_scols])); } void vdev_raidz_map_free(raidz_map_t *rm) { for (int i = 0; i < rm->rm_nrows; i++) vdev_raidz_row_free(rm->rm_row[i]); kmem_free(rm, offsetof(raidz_map_t, rm_row[rm->rm_nrows])); } static void vdev_raidz_map_free_vsd(zio_t *zio) { raidz_map_t *rm = zio->io_vsd; ASSERT0(rm->rm_freed); rm->rm_freed = B_TRUE; if (rm->rm_reports == 0) { vdev_raidz_map_free(rm); } } /*ARGSUSED*/ static void vdev_raidz_cksum_free(void *arg, size_t ignored) { raidz_map_t *rm = arg; ASSERT3U(rm->rm_reports, >, 0); if (--rm->rm_reports == 0 && rm->rm_freed) vdev_raidz_map_free(rm); } static void vdev_raidz_cksum_finish(zio_cksum_report_t *zcr, const abd_t *good_data) { raidz_map_t *rm = zcr->zcr_cbdata; const size_t c = zcr->zcr_cbinfo; size_t x, offset; if (good_data == NULL) { zfs_ereport_finish_checksum(zcr, NULL, NULL, B_FALSE); return; } ASSERT3U(rm->rm_nrows, ==, 1); raidz_row_t *rr = rm->rm_row[0]; const abd_t *good = NULL; const abd_t *bad = rr->rr_col[c].rc_abd; if (c < rr->rr_firstdatacol) { /* * The first time through, calculate the parity blocks for * the good data (this relies on the fact that the good * data never changes for a given logical ZIO) */ if (rr->rr_col[0].rc_gdata == NULL) { abd_t *bad_parity[VDEV_RAIDZ_MAXPARITY]; /* * Set up the rr_col[]s to generate the parity for * good_data, first saving the parity bufs and * replacing them with buffers to hold the result. */ for (x = 0; x < rr->rr_firstdatacol; x++) { bad_parity[x] = rr->rr_col[x].rc_abd; rr->rr_col[x].rc_abd = rr->rr_col[x].rc_gdata = abd_alloc_sametype(rr->rr_col[x].rc_abd, rr->rr_col[x].rc_size); } /* fill in the data columns from good_data */ offset = 0; for (; x < rr->rr_cols; x++) { - abd_put(rr->rr_col[x].rc_abd); + abd_free(rr->rr_col[x].rc_abd); rr->rr_col[x].rc_abd = abd_get_offset_size((abd_t *)good_data, offset, rr->rr_col[x].rc_size); offset += rr->rr_col[x].rc_size; } /* * Construct the parity from the good data. */ vdev_raidz_generate_parity_row(rm, rr); /* restore everything back to its original state */ for (x = 0; x < rr->rr_firstdatacol; x++) rr->rr_col[x].rc_abd = bad_parity[x]; offset = 0; for (x = rr->rr_firstdatacol; x < rr->rr_cols; x++) { - abd_put(rr->rr_col[x].rc_abd); + abd_free(rr->rr_col[x].rc_abd); rr->rr_col[x].rc_abd = abd_get_offset_size( rr->rr_abd_copy, offset, rr->rr_col[x].rc_size); offset += rr->rr_col[x].rc_size; } } ASSERT3P(rr->rr_col[c].rc_gdata, !=, NULL); good = abd_get_offset_size(rr->rr_col[c].rc_gdata, 0, rr->rr_col[c].rc_size); } else { /* adjust good_data to point at the start of our column */ offset = 0; for (x = rr->rr_firstdatacol; x < c; x++) offset += rr->rr_col[x].rc_size; good = abd_get_offset_size((abd_t *)good_data, offset, rr->rr_col[c].rc_size); } /* we drop the ereport if it ends up that the data was good */ zfs_ereport_finish_checksum(zcr, good, bad, B_TRUE); - abd_put((abd_t *)good); + abd_free((abd_t *)good); } /* * Invoked indirectly by zfs_ereport_start_checksum(), called * below when our read operation fails completely. The main point * is to keep a copy of everything we read from disk, so that at * vdev_raidz_cksum_finish() time we can compare it with the good data. */ static void vdev_raidz_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *arg) { size_t c = (size_t)(uintptr_t)arg; raidz_map_t *rm = zio->io_vsd; /* set up the report and bump the refcount */ zcr->zcr_cbdata = rm; zcr->zcr_cbinfo = c; zcr->zcr_finish = vdev_raidz_cksum_finish; zcr->zcr_free = vdev_raidz_cksum_free; rm->rm_reports++; ASSERT3U(rm->rm_reports, >, 0); ASSERT3U(rm->rm_nrows, ==, 1); if (rm->rm_row[0]->rr_abd_copy != NULL) return; /* * It's the first time we're called for this raidz_map_t, so we need * to copy the data aside; there's no guarantee that our zio's buffer * won't be re-used for something else. * * Our parity data is already in separate buffers, so there's no need * to copy them. */ for (int i = 0; i < rm->rm_nrows; i++) { raidz_row_t *rr = rm->rm_row[i]; size_t offset = 0; size_t size = 0; for (c = rr->rr_firstdatacol; c < rr->rr_cols; c++) size += rr->rr_col[c].rc_size; rr->rr_abd_copy = abd_alloc_for_io(size, B_FALSE); for (c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { raidz_col_t *col = &rr->rr_col[c]; abd_t *tmp = abd_get_offset_size(rr->rr_abd_copy, offset, col->rc_size); abd_copy(tmp, col->rc_abd, col->rc_size); - abd_put(col->rc_abd); + abd_free(col->rc_abd); col->rc_abd = tmp; offset += col->rc_size; } ASSERT3U(offset, ==, size); } } static const zio_vsd_ops_t vdev_raidz_vsd_ops = { .vsd_free = vdev_raidz_map_free_vsd, .vsd_cksum_report = vdev_raidz_cksum_report }; /* * Divides the IO evenly across all child vdevs; usually, dcols is * the number of children in the target vdev. * * Avoid inlining the function to keep vdev_raidz_io_start(), which * is this functions only caller, as small as possible on the stack. */ noinline raidz_map_t * vdev_raidz_map_alloc(zio_t *zio, uint64_t ashift, uint64_t dcols, uint64_t nparity) { raidz_row_t *rr; /* The starting RAIDZ (parent) vdev sector of the block. */ uint64_t b = zio->io_offset >> ashift; /* The zio's size in units of the vdev's minimum sector size. */ uint64_t s = zio->io_size >> ashift; /* The first column for this stripe. */ uint64_t f = b % dcols; /* The starting byte offset on each child vdev. */ uint64_t o = (b / dcols) << ashift; uint64_t q, r, c, bc, col, acols, scols, coff, devidx, asize, tot; - uint64_t off = 0; raidz_map_t *rm = kmem_zalloc(offsetof(raidz_map_t, rm_row[1]), KM_SLEEP); rm->rm_nrows = 1; /* * "Quotient": The number of data sectors for this stripe on all but * the "big column" child vdevs that also contain "remainder" data. */ q = s / (dcols - nparity); /* * "Remainder": The number of partial stripe data sectors in this I/O. * This will add a sector to some, but not all, child vdevs. */ r = s - q * (dcols - nparity); /* The number of "big columns" - those which contain remainder data. */ bc = (r == 0 ? 0 : r + nparity); /* * The total number of data and parity sectors associated with * this I/O. */ tot = s + nparity * (q + (r == 0 ? 0 : 1)); /* * acols: The columns that will be accessed. * scols: The columns that will be accessed or skipped. */ if (q == 0) { /* Our I/O request doesn't span all child vdevs. */ acols = bc; scols = MIN(dcols, roundup(bc, nparity + 1)); } else { acols = dcols; scols = dcols; } ASSERT3U(acols, <=, scols); rr = kmem_alloc(offsetof(raidz_row_t, rr_col[scols]), KM_SLEEP); rm->rm_row[0] = rr; rr->rr_cols = acols; rr->rr_scols = scols; rr->rr_bigcols = bc; rr->rr_missingdata = 0; rr->rr_missingparity = 0; rr->rr_firstdatacol = nparity; rr->rr_abd_copy = NULL; rr->rr_abd_empty = NULL; rr->rr_nempty = 0; #ifdef ZFS_DEBUG rr->rr_offset = zio->io_offset; rr->rr_size = zio->io_size; #endif asize = 0; for (c = 0; c < scols; c++) { raidz_col_t *rc = &rr->rr_col[c]; col = f + c; coff = o; if (col >= dcols) { col -= dcols; coff += 1ULL << ashift; } rc->rc_devidx = col; rc->rc_offset = coff; rc->rc_abd = NULL; rc->rc_gdata = NULL; rc->rc_orig_data = NULL; rc->rc_error = 0; rc->rc_tried = 0; rc->rc_skipped = 0; rc->rc_repair = 0; rc->rc_need_orig_restore = B_FALSE; if (c >= acols) rc->rc_size = 0; else if (c < bc) rc->rc_size = (q + 1) << ashift; else rc->rc_size = q << ashift; asize += rc->rc_size; } ASSERT3U(asize, ==, tot << ashift); rm->rm_nskip = roundup(tot, nparity + 1) - tot; rm->rm_skipstart = bc; for (c = 0; c < rr->rr_firstdatacol; c++) rr->rr_col[c].rc_abd = abd_alloc_linear(rr->rr_col[c].rc_size, B_FALSE); - rr->rr_col[c].rc_abd = abd_get_offset_size(zio->io_abd, 0, - rr->rr_col[c].rc_size); - off = rr->rr_col[c].rc_size; - - for (c = c + 1; c < acols; c++) { + for (uint64_t off = 0; c < acols; c++) { raidz_col_t *rc = &rr->rr_col[c]; - rc->rc_abd = abd_get_offset_size(zio->io_abd, off, rc->rc_size); + rc->rc_abd = abd_get_offset_struct(&rc->rc_abdstruct, + zio->io_abd, off, rc->rc_size); off += rc->rc_size; } /* * If all data stored spans all columns, there's a danger that parity * will always be on the same device and, since parity isn't read * during normal operation, that device's I/O bandwidth won't be * used effectively. We therefore switch the parity every 1MB. * * ... at least that was, ostensibly, the theory. As a practical * matter unless we juggle the parity between all devices evenly, we * won't see any benefit. Further, occasional writes that aren't a * multiple of the LCM of the number of children and the minimum * stripe width are sufficient to avoid pessimal behavior. * Unfortunately, this decision created an implicit on-disk format * requirement that we need to support for all eternity, but only * for single-parity RAID-Z. * * If we intend to skip a sector in the zeroth column for padding * we must make sure to note this swap. We will never intend to * skip the first column since at least one data and one parity * column must appear in each row. */ ASSERT(rr->rr_cols >= 2); ASSERT(rr->rr_col[0].rc_size == rr->rr_col[1].rc_size); if (rr->rr_firstdatacol == 1 && (zio->io_offset & (1ULL << 20))) { devidx = rr->rr_col[0].rc_devidx; o = rr->rr_col[0].rc_offset; rr->rr_col[0].rc_devidx = rr->rr_col[1].rc_devidx; rr->rr_col[0].rc_offset = rr->rr_col[1].rc_offset; rr->rr_col[1].rc_devidx = devidx; rr->rr_col[1].rc_offset = o; if (rm->rm_skipstart == 0) rm->rm_skipstart = 1; } /* init RAIDZ parity ops */ rm->rm_ops = vdev_raidz_math_get_ops(); return (rm); } struct pqr_struct { uint64_t *p; uint64_t *q; uint64_t *r; }; static int vdev_raidz_p_func(void *buf, size_t size, void *private) { struct pqr_struct *pqr = private; const uint64_t *src = buf; int i, cnt = size / sizeof (src[0]); ASSERT(pqr->p && !pqr->q && !pqr->r); for (i = 0; i < cnt; i++, src++, pqr->p++) *pqr->p ^= *src; return (0); } static int vdev_raidz_pq_func(void *buf, size_t size, void *private) { struct pqr_struct *pqr = private; const uint64_t *src = buf; uint64_t mask; int i, cnt = size / sizeof (src[0]); ASSERT(pqr->p && pqr->q && !pqr->r); for (i = 0; i < cnt; i++, src++, pqr->p++, pqr->q++) { *pqr->p ^= *src; VDEV_RAIDZ_64MUL_2(*pqr->q, mask); *pqr->q ^= *src; } return (0); } static int vdev_raidz_pqr_func(void *buf, size_t size, void *private) { struct pqr_struct *pqr = private; const uint64_t *src = buf; uint64_t mask; int i, cnt = size / sizeof (src[0]); ASSERT(pqr->p && pqr->q && pqr->r); for (i = 0; i < cnt; i++, src++, pqr->p++, pqr->q++, pqr->r++) { *pqr->p ^= *src; VDEV_RAIDZ_64MUL_2(*pqr->q, mask); *pqr->q ^= *src; VDEV_RAIDZ_64MUL_4(*pqr->r, mask); *pqr->r ^= *src; } return (0); } static void vdev_raidz_generate_parity_p(raidz_row_t *rr) { uint64_t *p = abd_to_buf(rr->rr_col[VDEV_RAIDZ_P].rc_abd); for (int c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { abd_t *src = rr->rr_col[c].rc_abd; if (c == rr->rr_firstdatacol) { abd_copy_to_buf(p, src, rr->rr_col[c].rc_size); } else { struct pqr_struct pqr = { p, NULL, NULL }; (void) abd_iterate_func(src, 0, rr->rr_col[c].rc_size, vdev_raidz_p_func, &pqr); } } } static void vdev_raidz_generate_parity_pq(raidz_row_t *rr) { uint64_t *p = abd_to_buf(rr->rr_col[VDEV_RAIDZ_P].rc_abd); uint64_t *q = abd_to_buf(rr->rr_col[VDEV_RAIDZ_Q].rc_abd); uint64_t pcnt = rr->rr_col[VDEV_RAIDZ_P].rc_size / sizeof (p[0]); ASSERT(rr->rr_col[VDEV_RAIDZ_P].rc_size == rr->rr_col[VDEV_RAIDZ_Q].rc_size); for (int c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { abd_t *src = rr->rr_col[c].rc_abd; uint64_t ccnt = rr->rr_col[c].rc_size / sizeof (p[0]); if (c == rr->rr_firstdatacol) { ASSERT(ccnt == pcnt || ccnt == 0); abd_copy_to_buf(p, src, rr->rr_col[c].rc_size); (void) memcpy(q, p, rr->rr_col[c].rc_size); for (uint64_t i = ccnt; i < pcnt; i++) { p[i] = 0; q[i] = 0; } } else { struct pqr_struct pqr = { p, q, NULL }; ASSERT(ccnt <= pcnt); (void) abd_iterate_func(src, 0, rr->rr_col[c].rc_size, vdev_raidz_pq_func, &pqr); /* * Treat short columns as though they are full of 0s. * Note that there's therefore nothing needed for P. */ uint64_t mask; for (uint64_t i = ccnt; i < pcnt; i++) { VDEV_RAIDZ_64MUL_2(q[i], mask); } } } } static void vdev_raidz_generate_parity_pqr(raidz_row_t *rr) { uint64_t *p = abd_to_buf(rr->rr_col[VDEV_RAIDZ_P].rc_abd); uint64_t *q = abd_to_buf(rr->rr_col[VDEV_RAIDZ_Q].rc_abd); uint64_t *r = abd_to_buf(rr->rr_col[VDEV_RAIDZ_R].rc_abd); uint64_t pcnt = rr->rr_col[VDEV_RAIDZ_P].rc_size / sizeof (p[0]); ASSERT(rr->rr_col[VDEV_RAIDZ_P].rc_size == rr->rr_col[VDEV_RAIDZ_Q].rc_size); ASSERT(rr->rr_col[VDEV_RAIDZ_P].rc_size == rr->rr_col[VDEV_RAIDZ_R].rc_size); for (int c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { abd_t *src = rr->rr_col[c].rc_abd; uint64_t ccnt = rr->rr_col[c].rc_size / sizeof (p[0]); if (c == rr->rr_firstdatacol) { ASSERT(ccnt == pcnt || ccnt == 0); abd_copy_to_buf(p, src, rr->rr_col[c].rc_size); (void) memcpy(q, p, rr->rr_col[c].rc_size); (void) memcpy(r, p, rr->rr_col[c].rc_size); for (uint64_t i = ccnt; i < pcnt; i++) { p[i] = 0; q[i] = 0; r[i] = 0; } } else { struct pqr_struct pqr = { p, q, r }; ASSERT(ccnt <= pcnt); (void) abd_iterate_func(src, 0, rr->rr_col[c].rc_size, vdev_raidz_pqr_func, &pqr); /* * Treat short columns as though they are full of 0s. * Note that there's therefore nothing needed for P. */ uint64_t mask; for (uint64_t i = ccnt; i < pcnt; i++) { VDEV_RAIDZ_64MUL_2(q[i], mask); VDEV_RAIDZ_64MUL_4(r[i], mask); } } } } /* * Generate RAID parity in the first virtual columns according to the number of * parity columns available. */ void vdev_raidz_generate_parity_row(raidz_map_t *rm, raidz_row_t *rr) { ASSERT3U(rr->rr_cols, !=, 0); /* Generate using the new math implementation */ if (vdev_raidz_math_generate(rm, rr) != RAIDZ_ORIGINAL_IMPL) return; switch (rr->rr_firstdatacol) { case 1: vdev_raidz_generate_parity_p(rr); break; case 2: vdev_raidz_generate_parity_pq(rr); break; case 3: vdev_raidz_generate_parity_pqr(rr); break; default: cmn_err(CE_PANIC, "invalid RAID-Z configuration"); } } void vdev_raidz_generate_parity(raidz_map_t *rm) { for (int i = 0; i < rm->rm_nrows; i++) { raidz_row_t *rr = rm->rm_row[i]; vdev_raidz_generate_parity_row(rm, rr); } } /* ARGSUSED */ static int vdev_raidz_reconst_p_func(void *dbuf, void *sbuf, size_t size, void *private) { uint64_t *dst = dbuf; uint64_t *src = sbuf; int cnt = size / sizeof (src[0]); for (int i = 0; i < cnt; i++) { dst[i] ^= src[i]; } return (0); } /* ARGSUSED */ static int vdev_raidz_reconst_q_pre_func(void *dbuf, void *sbuf, size_t size, void *private) { uint64_t *dst = dbuf; uint64_t *src = sbuf; uint64_t mask; int cnt = size / sizeof (dst[0]); for (int i = 0; i < cnt; i++, dst++, src++) { VDEV_RAIDZ_64MUL_2(*dst, mask); *dst ^= *src; } return (0); } /* ARGSUSED */ static int vdev_raidz_reconst_q_pre_tail_func(void *buf, size_t size, void *private) { uint64_t *dst = buf; uint64_t mask; int cnt = size / sizeof (dst[0]); for (int i = 0; i < cnt; i++, dst++) { /* same operation as vdev_raidz_reconst_q_pre_func() on dst */ VDEV_RAIDZ_64MUL_2(*dst, mask); } return (0); } struct reconst_q_struct { uint64_t *q; int exp; }; static int vdev_raidz_reconst_q_post_func(void *buf, size_t size, void *private) { struct reconst_q_struct *rq = private; uint64_t *dst = buf; int cnt = size / sizeof (dst[0]); for (int i = 0; i < cnt; i++, dst++, rq->q++) { int j; uint8_t *b; *dst ^= *rq->q; for (j = 0, b = (uint8_t *)dst; j < 8; j++, b++) { *b = vdev_raidz_exp2(*b, rq->exp); } } return (0); } struct reconst_pq_struct { uint8_t *p; uint8_t *q; uint8_t *pxy; uint8_t *qxy; int aexp; int bexp; }; static int vdev_raidz_reconst_pq_func(void *xbuf, void *ybuf, size_t size, void *private) { struct reconst_pq_struct *rpq = private; uint8_t *xd = xbuf; uint8_t *yd = ybuf; for (int i = 0; i < size; i++, rpq->p++, rpq->q++, rpq->pxy++, rpq->qxy++, xd++, yd++) { *xd = vdev_raidz_exp2(*rpq->p ^ *rpq->pxy, rpq->aexp) ^ vdev_raidz_exp2(*rpq->q ^ *rpq->qxy, rpq->bexp); *yd = *rpq->p ^ *rpq->pxy ^ *xd; } return (0); } static int vdev_raidz_reconst_pq_tail_func(void *xbuf, size_t size, void *private) { struct reconst_pq_struct *rpq = private; uint8_t *xd = xbuf; for (int i = 0; i < size; i++, rpq->p++, rpq->q++, rpq->pxy++, rpq->qxy++, xd++) { /* same operation as vdev_raidz_reconst_pq_func() on xd */ *xd = vdev_raidz_exp2(*rpq->p ^ *rpq->pxy, rpq->aexp) ^ vdev_raidz_exp2(*rpq->q ^ *rpq->qxy, rpq->bexp); } return (0); } static int vdev_raidz_reconstruct_p(raidz_row_t *rr, int *tgts, int ntgts) { int x = tgts[0]; abd_t *dst, *src; ASSERT3U(ntgts, ==, 1); ASSERT3U(x, >=, rr->rr_firstdatacol); ASSERT3U(x, <, rr->rr_cols); ASSERT3U(rr->rr_col[x].rc_size, <=, rr->rr_col[VDEV_RAIDZ_P].rc_size); src = rr->rr_col[VDEV_RAIDZ_P].rc_abd; dst = rr->rr_col[x].rc_abd; abd_copy_from_buf(dst, abd_to_buf(src), rr->rr_col[x].rc_size); for (int c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { uint64_t size = MIN(rr->rr_col[x].rc_size, rr->rr_col[c].rc_size); src = rr->rr_col[c].rc_abd; if (c == x) continue; (void) abd_iterate_func2(dst, src, 0, 0, size, vdev_raidz_reconst_p_func, NULL); } return (1 << VDEV_RAIDZ_P); } static int vdev_raidz_reconstruct_q(raidz_row_t *rr, int *tgts, int ntgts) { int x = tgts[0]; int c, exp; abd_t *dst, *src; ASSERT(ntgts == 1); ASSERT(rr->rr_col[x].rc_size <= rr->rr_col[VDEV_RAIDZ_Q].rc_size); for (c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { uint64_t size = (c == x) ? 0 : MIN(rr->rr_col[x].rc_size, rr->rr_col[c].rc_size); src = rr->rr_col[c].rc_abd; dst = rr->rr_col[x].rc_abd; if (c == rr->rr_firstdatacol) { abd_copy(dst, src, size); if (rr->rr_col[x].rc_size > size) { abd_zero_off(dst, size, rr->rr_col[x].rc_size - size); } } else { ASSERT3U(size, <=, rr->rr_col[x].rc_size); (void) abd_iterate_func2(dst, src, 0, 0, size, vdev_raidz_reconst_q_pre_func, NULL); (void) abd_iterate_func(dst, size, rr->rr_col[x].rc_size - size, vdev_raidz_reconst_q_pre_tail_func, NULL); } } src = rr->rr_col[VDEV_RAIDZ_Q].rc_abd; dst = rr->rr_col[x].rc_abd; exp = 255 - (rr->rr_cols - 1 - x); struct reconst_q_struct rq = { abd_to_buf(src), exp }; (void) abd_iterate_func(dst, 0, rr->rr_col[x].rc_size, vdev_raidz_reconst_q_post_func, &rq); return (1 << VDEV_RAIDZ_Q); } static int vdev_raidz_reconstruct_pq(raidz_row_t *rr, int *tgts, int ntgts) { uint8_t *p, *q, *pxy, *qxy, tmp, a, b, aexp, bexp; abd_t *pdata, *qdata; uint64_t xsize, ysize; int x = tgts[0]; int y = tgts[1]; abd_t *xd, *yd; ASSERT(ntgts == 2); ASSERT(x < y); ASSERT(x >= rr->rr_firstdatacol); ASSERT(y < rr->rr_cols); ASSERT(rr->rr_col[x].rc_size >= rr->rr_col[y].rc_size); /* * Move the parity data aside -- we're going to compute parity as * though columns x and y were full of zeros -- Pxy and Qxy. We want to * reuse the parity generation mechanism without trashing the actual * parity so we make those columns appear to be full of zeros by * setting their lengths to zero. */ pdata = rr->rr_col[VDEV_RAIDZ_P].rc_abd; qdata = rr->rr_col[VDEV_RAIDZ_Q].rc_abd; xsize = rr->rr_col[x].rc_size; ysize = rr->rr_col[y].rc_size; rr->rr_col[VDEV_RAIDZ_P].rc_abd = abd_alloc_linear(rr->rr_col[VDEV_RAIDZ_P].rc_size, B_TRUE); rr->rr_col[VDEV_RAIDZ_Q].rc_abd = abd_alloc_linear(rr->rr_col[VDEV_RAIDZ_Q].rc_size, B_TRUE); rr->rr_col[x].rc_size = 0; rr->rr_col[y].rc_size = 0; vdev_raidz_generate_parity_pq(rr); rr->rr_col[x].rc_size = xsize; rr->rr_col[y].rc_size = ysize; p = abd_to_buf(pdata); q = abd_to_buf(qdata); pxy = abd_to_buf(rr->rr_col[VDEV_RAIDZ_P].rc_abd); qxy = abd_to_buf(rr->rr_col[VDEV_RAIDZ_Q].rc_abd); xd = rr->rr_col[x].rc_abd; yd = rr->rr_col[y].rc_abd; /* * We now have: * Pxy = P + D_x + D_y * Qxy = Q + 2^(ndevs - 1 - x) * D_x + 2^(ndevs - 1 - y) * D_y * * We can then solve for D_x: * D_x = A * (P + Pxy) + B * (Q + Qxy) * where * A = 2^(x - y) * (2^(x - y) + 1)^-1 * B = 2^(ndevs - 1 - x) * (2^(x - y) + 1)^-1 * * With D_x in hand, we can easily solve for D_y: * D_y = P + Pxy + D_x */ a = vdev_raidz_pow2[255 + x - y]; b = vdev_raidz_pow2[255 - (rr->rr_cols - 1 - x)]; tmp = 255 - vdev_raidz_log2[a ^ 1]; aexp = vdev_raidz_log2[vdev_raidz_exp2(a, tmp)]; bexp = vdev_raidz_log2[vdev_raidz_exp2(b, tmp)]; ASSERT3U(xsize, >=, ysize); struct reconst_pq_struct rpq = { p, q, pxy, qxy, aexp, bexp }; (void) abd_iterate_func2(xd, yd, 0, 0, ysize, vdev_raidz_reconst_pq_func, &rpq); (void) abd_iterate_func(xd, ysize, xsize - ysize, vdev_raidz_reconst_pq_tail_func, &rpq); abd_free(rr->rr_col[VDEV_RAIDZ_P].rc_abd); abd_free(rr->rr_col[VDEV_RAIDZ_Q].rc_abd); /* * Restore the saved parity data. */ rr->rr_col[VDEV_RAIDZ_P].rc_abd = pdata; rr->rr_col[VDEV_RAIDZ_Q].rc_abd = qdata; return ((1 << VDEV_RAIDZ_P) | (1 << VDEV_RAIDZ_Q)); } /* BEGIN CSTYLED */ /* * In the general case of reconstruction, we must solve the system of linear * equations defined by the coefficients used to generate parity as well as * the contents of the data and parity disks. This can be expressed with * vectors for the original data (D) and the actual data (d) and parity (p) * and a matrix composed of the identity matrix (I) and a dispersal matrix (V): * * __ __ __ __ * | | __ __ | p_0 | * | V | | D_0 | | p_m-1 | * | | x | : | = | d_0 | * | I | | D_n-1 | | : | * | | ~~ ~~ | d_n-1 | * ~~ ~~ ~~ ~~ * * I is simply a square identity matrix of size n, and V is a vandermonde * matrix defined by the coefficients we chose for the various parity columns * (1, 2, 4). Note that these values were chosen both for simplicity, speedy * computation as well as linear separability. * * __ __ __ __ * | 1 .. 1 1 1 | | p_0 | * | 2^n-1 .. 4 2 1 | __ __ | : | * | 4^n-1 .. 16 4 1 | | D_0 | | p_m-1 | * | 1 .. 0 0 0 | | D_1 | | d_0 | * | 0 .. 0 0 0 | x | D_2 | = | d_1 | * | : : : : | | : | | d_2 | * | 0 .. 1 0 0 | | D_n-1 | | : | * | 0 .. 0 1 0 | ~~ ~~ | : | * | 0 .. 0 0 1 | | d_n-1 | * ~~ ~~ ~~ ~~ * * Note that I, V, d, and p are known. To compute D, we must invert the * matrix and use the known data and parity values to reconstruct the unknown * data values. We begin by removing the rows in V|I and d|p that correspond * to failed or missing columns; we then make V|I square (n x n) and d|p * sized n by removing rows corresponding to unused parity from the bottom up * to generate (V|I)' and (d|p)'. We can then generate the inverse of (V|I)' * using Gauss-Jordan elimination. In the example below we use m=3 parity * columns, n=8 data columns, with errors in d_1, d_2, and p_1: * __ __ * | 1 1 1 1 1 1 1 1 | * | 128 64 32 16 8 4 2 1 | <-----+-+-- missing disks * | 19 205 116 29 64 16 4 1 | / / * | 1 0 0 0 0 0 0 0 | / / * | 0 1 0 0 0 0 0 0 | <--' / * (V|I) = | 0 0 1 0 0 0 0 0 | <---' * | 0 0 0 1 0 0 0 0 | * | 0 0 0 0 1 0 0 0 | * | 0 0 0 0 0 1 0 0 | * | 0 0 0 0 0 0 1 0 | * | 0 0 0 0 0 0 0 1 | * ~~ ~~ * __ __ * | 1 1 1 1 1 1 1 1 | * | 128 64 32 16 8 4 2 1 | * | 19 205 116 29 64 16 4 1 | * | 1 0 0 0 0 0 0 0 | * | 0 1 0 0 0 0 0 0 | * (V|I)' = | 0 0 1 0 0 0 0 0 | * | 0 0 0 1 0 0 0 0 | * | 0 0 0 0 1 0 0 0 | * | 0 0 0 0 0 1 0 0 | * | 0 0 0 0 0 0 1 0 | * | 0 0 0 0 0 0 0 1 | * ~~ ~~ * * Here we employ Gauss-Jordan elimination to find the inverse of (V|I)'. We * have carefully chosen the seed values 1, 2, and 4 to ensure that this * matrix is not singular. * __ __ * | 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 | * | 19 205 116 29 64 16 4 1 0 1 0 0 0 0 0 0 | * | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 | * | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 | * | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 | * | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 | * | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 | * | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 | * ~~ ~~ * __ __ * | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 | * | 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 | * | 19 205 116 29 64 16 4 1 0 1 0 0 0 0 0 0 | * | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 | * | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 | * | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 | * | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 | * | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 | * ~~ ~~ * __ __ * | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 | * | 0 1 1 0 0 0 0 0 1 0 1 1 1 1 1 1 | * | 0 205 116 0 0 0 0 0 0 1 19 29 64 16 4 1 | * | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 | * | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 | * | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 | * | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 | * | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 | * ~~ ~~ * __ __ * | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 | * | 0 1 1 0 0 0 0 0 1 0 1 1 1 1 1 1 | * | 0 0 185 0 0 0 0 0 205 1 222 208 141 221 201 204 | * | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 | * | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 | * | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 | * | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 | * | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 | * ~~ ~~ * __ __ * | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 | * | 0 1 1 0 0 0 0 0 1 0 1 1 1 1 1 1 | * | 0 0 1 0 0 0 0 0 166 100 4 40 158 168 216 209 | * | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 | * | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 | * | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 | * | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 | * | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 | * ~~ ~~ * __ __ * | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 | * | 0 1 0 0 0 0 0 0 167 100 5 41 159 169 217 208 | * | 0 0 1 0 0 0 0 0 166 100 4 40 158 168 216 209 | * | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 | * | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 | * | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 | * | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 | * | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 | * ~~ ~~ * __ __ * | 0 0 1 0 0 0 0 0 | * | 167 100 5 41 159 169 217 208 | * | 166 100 4 40 158 168 216 209 | * (V|I)'^-1 = | 0 0 0 1 0 0 0 0 | * | 0 0 0 0 1 0 0 0 | * | 0 0 0 0 0 1 0 0 | * | 0 0 0 0 0 0 1 0 | * | 0 0 0 0 0 0 0 1 | * ~~ ~~ * * We can then simply compute D = (V|I)'^-1 x (d|p)' to discover the values * of the missing data. * * As is apparent from the example above, the only non-trivial rows in the * inverse matrix correspond to the data disks that we're trying to * reconstruct. Indeed, those are the only rows we need as the others would * only be useful for reconstructing data known or assumed to be valid. For * that reason, we only build the coefficients in the rows that correspond to * targeted columns. */ /* END CSTYLED */ static void vdev_raidz_matrix_init(raidz_row_t *rr, int n, int nmap, int *map, uint8_t **rows) { int i, j; int pow; ASSERT(n == rr->rr_cols - rr->rr_firstdatacol); /* * Fill in the missing rows of interest. */ for (i = 0; i < nmap; i++) { ASSERT3S(0, <=, map[i]); ASSERT3S(map[i], <=, 2); pow = map[i] * n; if (pow > 255) pow -= 255; ASSERT(pow <= 255); for (j = 0; j < n; j++) { pow -= map[i]; if (pow < 0) pow += 255; rows[i][j] = vdev_raidz_pow2[pow]; } } } static void vdev_raidz_matrix_invert(raidz_row_t *rr, int n, int nmissing, int *missing, uint8_t **rows, uint8_t **invrows, const uint8_t *used) { int i, j, ii, jj; uint8_t log; /* * Assert that the first nmissing entries from the array of used * columns correspond to parity columns and that subsequent entries * correspond to data columns. */ for (i = 0; i < nmissing; i++) { ASSERT3S(used[i], <, rr->rr_firstdatacol); } for (; i < n; i++) { ASSERT3S(used[i], >=, rr->rr_firstdatacol); } /* * First initialize the storage where we'll compute the inverse rows. */ for (i = 0; i < nmissing; i++) { for (j = 0; j < n; j++) { invrows[i][j] = (i == j) ? 1 : 0; } } /* * Subtract all trivial rows from the rows of consequence. */ for (i = 0; i < nmissing; i++) { for (j = nmissing; j < n; j++) { ASSERT3U(used[j], >=, rr->rr_firstdatacol); jj = used[j] - rr->rr_firstdatacol; ASSERT3S(jj, <, n); invrows[i][j] = rows[i][jj]; rows[i][jj] = 0; } } /* * For each of the rows of interest, we must normalize it and subtract * a multiple of it from the other rows. */ for (i = 0; i < nmissing; i++) { for (j = 0; j < missing[i]; j++) { ASSERT0(rows[i][j]); } ASSERT3U(rows[i][missing[i]], !=, 0); /* * Compute the inverse of the first element and multiply each * element in the row by that value. */ log = 255 - vdev_raidz_log2[rows[i][missing[i]]]; for (j = 0; j < n; j++) { rows[i][j] = vdev_raidz_exp2(rows[i][j], log); invrows[i][j] = vdev_raidz_exp2(invrows[i][j], log); } for (ii = 0; ii < nmissing; ii++) { if (i == ii) continue; ASSERT3U(rows[ii][missing[i]], !=, 0); log = vdev_raidz_log2[rows[ii][missing[i]]]; for (j = 0; j < n; j++) { rows[ii][j] ^= vdev_raidz_exp2(rows[i][j], log); invrows[ii][j] ^= vdev_raidz_exp2(invrows[i][j], log); } } } /* * Verify that the data that is left in the rows are properly part of * an identity matrix. */ for (i = 0; i < nmissing; i++) { for (j = 0; j < n; j++) { if (j == missing[i]) { ASSERT3U(rows[i][j], ==, 1); } else { ASSERT0(rows[i][j]); } } } } static void vdev_raidz_matrix_reconstruct(raidz_row_t *rr, int n, int nmissing, int *missing, uint8_t **invrows, const uint8_t *used) { int i, j, x, cc, c; uint8_t *src; uint64_t ccount; uint8_t *dst[VDEV_RAIDZ_MAXPARITY] = { NULL }; uint64_t dcount[VDEV_RAIDZ_MAXPARITY] = { 0 }; uint8_t log = 0; uint8_t val; int ll; uint8_t *invlog[VDEV_RAIDZ_MAXPARITY]; uint8_t *p, *pp; size_t psize; psize = sizeof (invlog[0][0]) * n * nmissing; p = kmem_alloc(psize, KM_SLEEP); for (pp = p, i = 0; i < nmissing; i++) { invlog[i] = pp; pp += n; } for (i = 0; i < nmissing; i++) { for (j = 0; j < n; j++) { ASSERT3U(invrows[i][j], !=, 0); invlog[i][j] = vdev_raidz_log2[invrows[i][j]]; } } for (i = 0; i < n; i++) { c = used[i]; ASSERT3U(c, <, rr->rr_cols); ccount = rr->rr_col[c].rc_size; ASSERT(ccount >= rr->rr_col[missing[0]].rc_size || i > 0); if (ccount == 0) continue; src = abd_to_buf(rr->rr_col[c].rc_abd); for (j = 0; j < nmissing; j++) { cc = missing[j] + rr->rr_firstdatacol; ASSERT3U(cc, >=, rr->rr_firstdatacol); ASSERT3U(cc, <, rr->rr_cols); ASSERT3U(cc, !=, c); dcount[j] = rr->rr_col[cc].rc_size; if (dcount[j] != 0) dst[j] = abd_to_buf(rr->rr_col[cc].rc_abd); } for (x = 0; x < ccount; x++, src++) { if (*src != 0) log = vdev_raidz_log2[*src]; for (cc = 0; cc < nmissing; cc++) { if (x >= dcount[cc]) continue; if (*src == 0) { val = 0; } else { if ((ll = log + invlog[cc][i]) >= 255) ll -= 255; val = vdev_raidz_pow2[ll]; } if (i == 0) dst[cc][x] = val; else dst[cc][x] ^= val; } } } kmem_free(p, psize); } static int vdev_raidz_reconstruct_general(raidz_row_t *rr, int *tgts, int ntgts) { int n, i, c, t, tt; int nmissing_rows; int missing_rows[VDEV_RAIDZ_MAXPARITY]; int parity_map[VDEV_RAIDZ_MAXPARITY]; uint8_t *p, *pp; size_t psize; uint8_t *rows[VDEV_RAIDZ_MAXPARITY]; uint8_t *invrows[VDEV_RAIDZ_MAXPARITY]; uint8_t *used; abd_t **bufs = NULL; int code = 0; /* * Matrix reconstruction can't use scatter ABDs yet, so we allocate * temporary linear ABDs if any non-linear ABDs are found. */ for (i = rr->rr_firstdatacol; i < rr->rr_cols; i++) { if (!abd_is_linear(rr->rr_col[i].rc_abd)) { bufs = kmem_alloc(rr->rr_cols * sizeof (abd_t *), KM_PUSHPAGE); for (c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { raidz_col_t *col = &rr->rr_col[c]; bufs[c] = col->rc_abd; if (bufs[c] != NULL) { col->rc_abd = abd_alloc_linear( col->rc_size, B_TRUE); abd_copy(col->rc_abd, bufs[c], col->rc_size); } } break; } } n = rr->rr_cols - rr->rr_firstdatacol; /* * Figure out which data columns are missing. */ nmissing_rows = 0; for (t = 0; t < ntgts; t++) { if (tgts[t] >= rr->rr_firstdatacol) { missing_rows[nmissing_rows++] = tgts[t] - rr->rr_firstdatacol; } } /* * Figure out which parity columns to use to help generate the missing * data columns. */ for (tt = 0, c = 0, i = 0; i < nmissing_rows; c++) { ASSERT(tt < ntgts); ASSERT(c < rr->rr_firstdatacol); /* * Skip any targeted parity columns. */ if (c == tgts[tt]) { tt++; continue; } code |= 1 << c; parity_map[i] = c; i++; } ASSERT(code != 0); ASSERT3U(code, <, 1 << VDEV_RAIDZ_MAXPARITY); psize = (sizeof (rows[0][0]) + sizeof (invrows[0][0])) * nmissing_rows * n + sizeof (used[0]) * n; p = kmem_alloc(psize, KM_SLEEP); for (pp = p, i = 0; i < nmissing_rows; i++) { rows[i] = pp; pp += n; invrows[i] = pp; pp += n; } used = pp; for (i = 0; i < nmissing_rows; i++) { used[i] = parity_map[i]; } for (tt = 0, c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { if (tt < nmissing_rows && c == missing_rows[tt] + rr->rr_firstdatacol) { tt++; continue; } ASSERT3S(i, <, n); used[i] = c; i++; } /* * Initialize the interesting rows of the matrix. */ vdev_raidz_matrix_init(rr, n, nmissing_rows, parity_map, rows); /* * Invert the matrix. */ vdev_raidz_matrix_invert(rr, n, nmissing_rows, missing_rows, rows, invrows, used); /* * Reconstruct the missing data using the generated matrix. */ vdev_raidz_matrix_reconstruct(rr, n, nmissing_rows, missing_rows, invrows, used); kmem_free(p, psize); /* * copy back from temporary linear abds and free them */ if (bufs) { for (c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { raidz_col_t *col = &rr->rr_col[c]; if (bufs[c] != NULL) { abd_copy(bufs[c], col->rc_abd, col->rc_size); abd_free(col->rc_abd); } col->rc_abd = bufs[c]; } kmem_free(bufs, rr->rr_cols * sizeof (abd_t *)); } return (code); } static int vdev_raidz_reconstruct_row(raidz_map_t *rm, raidz_row_t *rr, const int *t, int nt) { int tgts[VDEV_RAIDZ_MAXPARITY], *dt; int ntgts; int i, c, ret; int code; int nbadparity, nbaddata; int parity_valid[VDEV_RAIDZ_MAXPARITY]; nbadparity = rr->rr_firstdatacol; nbaddata = rr->rr_cols - nbadparity; ntgts = 0; for (i = 0, c = 0; c < rr->rr_cols; c++) { if (c < rr->rr_firstdatacol) parity_valid[c] = B_FALSE; if (i < nt && c == t[i]) { tgts[ntgts++] = c; i++; } else if (rr->rr_col[c].rc_error != 0) { tgts[ntgts++] = c; } else if (c >= rr->rr_firstdatacol) { nbaddata--; } else { parity_valid[c] = B_TRUE; nbadparity--; } } ASSERT(ntgts >= nt); ASSERT(nbaddata >= 0); ASSERT(nbaddata + nbadparity == ntgts); dt = &tgts[nbadparity]; /* Reconstruct using the new math implementation */ ret = vdev_raidz_math_reconstruct(rm, rr, parity_valid, dt, nbaddata); if (ret != RAIDZ_ORIGINAL_IMPL) return (ret); /* * See if we can use any of our optimized reconstruction routines. */ switch (nbaddata) { case 1: if (parity_valid[VDEV_RAIDZ_P]) return (vdev_raidz_reconstruct_p(rr, dt, 1)); ASSERT(rr->rr_firstdatacol > 1); if (parity_valid[VDEV_RAIDZ_Q]) return (vdev_raidz_reconstruct_q(rr, dt, 1)); ASSERT(rr->rr_firstdatacol > 2); break; case 2: ASSERT(rr->rr_firstdatacol > 1); if (parity_valid[VDEV_RAIDZ_P] && parity_valid[VDEV_RAIDZ_Q]) return (vdev_raidz_reconstruct_pq(rr, dt, 2)); ASSERT(rr->rr_firstdatacol > 2); break; } code = vdev_raidz_reconstruct_general(rr, tgts, ntgts); ASSERT(code < (1 << VDEV_RAIDZ_MAXPARITY)); ASSERT(code > 0); return (code); } static int vdev_raidz_open(vdev_t *vd, uint64_t *asize, uint64_t *max_asize, uint64_t *logical_ashift, uint64_t *physical_ashift) { vdev_raidz_t *vdrz = vd->vdev_tsd; uint64_t nparity = vdrz->vd_nparity; int c; int lasterror = 0; int numerrors = 0; ASSERT(nparity > 0); if (nparity > VDEV_RAIDZ_MAXPARITY || vd->vdev_children < nparity + 1) { vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL; return (SET_ERROR(EINVAL)); } vdev_open_children(vd); for (c = 0; c < vd->vdev_children; c++) { vdev_t *cvd = vd->vdev_child[c]; if (cvd->vdev_open_error != 0) { lasterror = cvd->vdev_open_error; numerrors++; continue; } *asize = MIN(*asize - 1, cvd->vdev_asize - 1) + 1; *max_asize = MIN(*max_asize - 1, cvd->vdev_max_asize - 1) + 1; *logical_ashift = MAX(*logical_ashift, cvd->vdev_ashift); *physical_ashift = MAX(*physical_ashift, cvd->vdev_physical_ashift); } *asize *= vd->vdev_children; *max_asize *= vd->vdev_children; if (numerrors > nparity) { vd->vdev_stat.vs_aux = VDEV_AUX_NO_REPLICAS; return (lasterror); } return (0); } static void vdev_raidz_close(vdev_t *vd) { for (int c = 0; c < vd->vdev_children; c++) { if (vd->vdev_child[c] != NULL) vdev_close(vd->vdev_child[c]); } } static uint64_t vdev_raidz_asize(vdev_t *vd, uint64_t psize) { vdev_raidz_t *vdrz = vd->vdev_tsd; uint64_t asize; uint64_t ashift = vd->vdev_top->vdev_ashift; uint64_t cols = vdrz->vd_logical_width; uint64_t nparity = vdrz->vd_nparity; asize = ((psize - 1) >> ashift) + 1; asize += nparity * ((asize + cols - nparity - 1) / (cols - nparity)); asize = roundup(asize, nparity + 1) << ashift; return (asize); } /* * The allocatable space for a raidz vdev is N * sizeof(smallest child) * so each child must provide at least 1/Nth of its asize. */ static uint64_t vdev_raidz_min_asize(vdev_t *vd) { return ((vd->vdev_min_asize + vd->vdev_children - 1) / vd->vdev_children); } void vdev_raidz_child_done(zio_t *zio) { raidz_col_t *rc = zio->io_private; rc->rc_error = zio->io_error; rc->rc_tried = 1; rc->rc_skipped = 0; } static void vdev_raidz_io_verify(vdev_t *vd, raidz_row_t *rr, int col) { #ifdef ZFS_DEBUG vdev_t *tvd = vd->vdev_top; range_seg64_t logical_rs, physical_rs, remain_rs; logical_rs.rs_start = rr->rr_offset; logical_rs.rs_end = logical_rs.rs_start + vdev_raidz_asize(vd, rr->rr_size); raidz_col_t *rc = &rr->rr_col[col]; vdev_t *cvd = vd->vdev_child[rc->rc_devidx]; vdev_xlate(cvd, &logical_rs, &physical_rs, &remain_rs); ASSERT(vdev_xlate_is_empty(&remain_rs)); ASSERT3U(rc->rc_offset, ==, physical_rs.rs_start); ASSERT3U(rc->rc_offset, <, physical_rs.rs_end); /* * It would be nice to assert that rs_end is equal * to rc_offset + rc_size but there might be an * optional I/O at the end that is not accounted in * rc_size. */ if (physical_rs.rs_end > rc->rc_offset + rc->rc_size) { ASSERT3U(physical_rs.rs_end, ==, rc->rc_offset + rc->rc_size + (1 << tvd->vdev_ashift)); } else { ASSERT3U(physical_rs.rs_end, ==, rc->rc_offset + rc->rc_size); } #endif } static void vdev_raidz_io_start_write(zio_t *zio, raidz_row_t *rr, uint64_t ashift) { vdev_t *vd = zio->io_vd; raidz_map_t *rm = zio->io_vsd; int c, i; vdev_raidz_generate_parity_row(rm, rr); for (int c = 0; c < rr->rr_cols; c++) { raidz_col_t *rc = &rr->rr_col[c]; if (rc->rc_size == 0) continue; /* Verify physical to logical translation */ vdev_raidz_io_verify(vd, rr, c); zio_nowait(zio_vdev_child_io(zio, NULL, vd->vdev_child[rc->rc_devidx], rc->rc_offset, rc->rc_abd, rc->rc_size, zio->io_type, zio->io_priority, 0, vdev_raidz_child_done, rc)); } /* * Generate optional I/Os for skip sectors to improve aggregation * contiguity. */ for (c = rm->rm_skipstart, i = 0; i < rm->rm_nskip; c++, i++) { ASSERT(c <= rr->rr_scols); if (c == rr->rr_scols) c = 0; raidz_col_t *rc = &rr->rr_col[c]; vdev_t *cvd = vd->vdev_child[rc->rc_devidx]; zio_nowait(zio_vdev_child_io(zio, NULL, cvd, rc->rc_offset + rc->rc_size, NULL, 1ULL << ashift, zio->io_type, zio->io_priority, ZIO_FLAG_NODATA | ZIO_FLAG_OPTIONAL, NULL, NULL)); } } static void vdev_raidz_io_start_read(zio_t *zio, raidz_row_t *rr) { vdev_t *vd = zio->io_vd; /* * Iterate over the columns in reverse order so that we hit the parity * last -- any errors along the way will force us to read the parity. */ for (int c = rr->rr_cols - 1; c >= 0; c--) { raidz_col_t *rc = &rr->rr_col[c]; if (rc->rc_size == 0) continue; vdev_t *cvd = vd->vdev_child[rc->rc_devidx]; if (!vdev_readable(cvd)) { if (c >= rr->rr_firstdatacol) rr->rr_missingdata++; else rr->rr_missingparity++; rc->rc_error = SET_ERROR(ENXIO); rc->rc_tried = 1; /* don't even try */ rc->rc_skipped = 1; continue; } if (vdev_dtl_contains(cvd, DTL_MISSING, zio->io_txg, 1)) { if (c >= rr->rr_firstdatacol) rr->rr_missingdata++; else rr->rr_missingparity++; rc->rc_error = SET_ERROR(ESTALE); rc->rc_skipped = 1; continue; } if (c >= rr->rr_firstdatacol || rr->rr_missingdata > 0 || (zio->io_flags & (ZIO_FLAG_SCRUB | ZIO_FLAG_RESILVER))) { zio_nowait(zio_vdev_child_io(zio, NULL, cvd, rc->rc_offset, rc->rc_abd, rc->rc_size, zio->io_type, zio->io_priority, 0, vdev_raidz_child_done, rc)); } } } /* * Start an IO operation on a RAIDZ VDev * * Outline: * - For write operations: * 1. Generate the parity data * 2. Create child zio write operations to each column's vdev, for both * data and parity. * 3. If the column skips any sectors for padding, create optional dummy * write zio children for those areas to improve aggregation continuity. * - For read operations: * 1. Create child zio read operations to each data column's vdev to read * the range of data required for zio. * 2. If this is a scrub or resilver operation, or if any of the data * vdevs have had errors, then create zio read operations to the parity * columns' VDevs as well. */ static void vdev_raidz_io_start(zio_t *zio) { vdev_t *vd = zio->io_vd; vdev_t *tvd = vd->vdev_top; vdev_raidz_t *vdrz = vd->vdev_tsd; raidz_map_t *rm; rm = vdev_raidz_map_alloc(zio, tvd->vdev_ashift, vdrz->vd_logical_width, vdrz->vd_nparity); /* * Until raidz expansion is implemented all maps for a raidz vdev * contain a single row. */ ASSERT3U(rm->rm_nrows, ==, 1); raidz_row_t *rr = rm->rm_row[0]; zio->io_vsd = rm; zio->io_vsd_ops = &vdev_raidz_vsd_ops; if (zio->io_type == ZIO_TYPE_WRITE) { vdev_raidz_io_start_write(zio, rr, tvd->vdev_ashift); } else { ASSERT(zio->io_type == ZIO_TYPE_READ); vdev_raidz_io_start_read(zio, rr); } zio_execute(zio); } /* * Report a checksum error for a child of a RAID-Z device. */ static void raidz_checksum_error(zio_t *zio, raidz_col_t *rc, abd_t *bad_data) { vdev_t *vd = zio->io_vd->vdev_child[rc->rc_devidx]; if (!(zio->io_flags & ZIO_FLAG_SPECULATIVE) && zio->io_priority != ZIO_PRIORITY_REBUILD) { zio_bad_cksum_t zbc; raidz_map_t *rm = zio->io_vsd; zbc.zbc_has_cksum = 0; zbc.zbc_injected = rm->rm_ecksuminjected; int ret = zfs_ereport_post_checksum(zio->io_spa, vd, &zio->io_bookmark, zio, rc->rc_offset, rc->rc_size, rc->rc_abd, bad_data, &zbc); if (ret != EALREADY) { mutex_enter(&vd->vdev_stat_lock); vd->vdev_stat.vs_checksum_errors++; mutex_exit(&vd->vdev_stat_lock); } } } /* * We keep track of whether or not there were any injected errors, so that * any ereports we generate can note it. */ static int raidz_checksum_verify(zio_t *zio) { zio_bad_cksum_t zbc; raidz_map_t *rm = zio->io_vsd; bzero(&zbc, sizeof (zio_bad_cksum_t)); int ret = zio_checksum_error(zio, &zbc); if (ret != 0 && zbc.zbc_injected != 0) rm->rm_ecksuminjected = 1; return (ret); } /* * Generate the parity from the data columns. If we tried and were able to * read the parity without error, verify that the generated parity matches the * data we read. If it doesn't, we fire off a checksum error. Return the * number of such failures. */ static int raidz_parity_verify(zio_t *zio, raidz_row_t *rr) { abd_t *orig[VDEV_RAIDZ_MAXPARITY]; int c, ret = 0; raidz_map_t *rm = zio->io_vsd; raidz_col_t *rc; blkptr_t *bp = zio->io_bp; enum zio_checksum checksum = (bp == NULL ? zio->io_prop.zp_checksum : (BP_IS_GANG(bp) ? ZIO_CHECKSUM_GANG_HEADER : BP_GET_CHECKSUM(bp))); if (checksum == ZIO_CHECKSUM_NOPARITY) return (ret); /* * All data columns must have been successfully read in order * to use them to generate parity columns for comparison. */ for (c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { rc = &rr->rr_col[c]; if (!rc->rc_tried || rc->rc_error != 0) return (ret); } for (c = 0; c < rr->rr_firstdatacol; c++) { rc = &rr->rr_col[c]; if (!rc->rc_tried || rc->rc_error != 0) continue; orig[c] = abd_alloc_sametype(rc->rc_abd, rc->rc_size); abd_copy(orig[c], rc->rc_abd, rc->rc_size); } /* * Regenerates parity even for !tried||rc_error!=0 columns. This * isn't harmful but it does have the side effect of fixing stuff * we didn't realize was necessary (i.e. even if we return 0). */ vdev_raidz_generate_parity_row(rm, rr); for (c = 0; c < rr->rr_firstdatacol; c++) { rc = &rr->rr_col[c]; if (!rc->rc_tried || rc->rc_error != 0) continue; if (abd_cmp(orig[c], rc->rc_abd) != 0) { raidz_checksum_error(zio, rc, orig[c]); rc->rc_error = SET_ERROR(ECKSUM); ret++; } abd_free(orig[c]); } return (ret); } static int vdev_raidz_worst_error(raidz_row_t *rr) { int error = 0; for (int c = 0; c < rr->rr_cols; c++) error = zio_worst_error(error, rr->rr_col[c].rc_error); return (error); } static void vdev_raidz_io_done_verified(zio_t *zio, raidz_row_t *rr) { int unexpected_errors = 0; int parity_errors = 0; int parity_untried = 0; int data_errors = 0; ASSERT3U(zio->io_type, ==, ZIO_TYPE_READ); for (int c = 0; c < rr->rr_cols; c++) { raidz_col_t *rc = &rr->rr_col[c]; if (rc->rc_error) { if (c < rr->rr_firstdatacol) parity_errors++; else data_errors++; if (!rc->rc_skipped) unexpected_errors++; } else if (c < rr->rr_firstdatacol && !rc->rc_tried) { parity_untried++; } } /* * If we read more parity disks than were used for * reconstruction, confirm that the other parity disks produced * correct data. * * Note that we also regenerate parity when resilvering so we * can write it out to failed devices later. */ if (parity_errors + parity_untried < rr->rr_firstdatacol - data_errors || (zio->io_flags & ZIO_FLAG_RESILVER)) { int n = raidz_parity_verify(zio, rr); unexpected_errors += n; ASSERT3U(parity_errors + n, <=, rr->rr_firstdatacol); } if (zio->io_error == 0 && spa_writeable(zio->io_spa) && (unexpected_errors > 0 || (zio->io_flags & ZIO_FLAG_RESILVER))) { /* * Use the good data we have in hand to repair damaged children. */ for (int c = 0; c < rr->rr_cols; c++) { raidz_col_t *rc = &rr->rr_col[c]; vdev_t *vd = zio->io_vd; vdev_t *cvd = vd->vdev_child[rc->rc_devidx]; if ((rc->rc_error == 0 || rc->rc_size == 0) && (rc->rc_repair == 0)) { continue; } zio_nowait(zio_vdev_child_io(zio, NULL, cvd, rc->rc_offset, rc->rc_abd, rc->rc_size, ZIO_TYPE_WRITE, zio->io_priority == ZIO_PRIORITY_REBUILD ? ZIO_PRIORITY_REBUILD : ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_IO_REPAIR | (unexpected_errors ? ZIO_FLAG_SELF_HEAL : 0), NULL, NULL)); } } } static void raidz_restore_orig_data(raidz_map_t *rm) { for (int i = 0; i < rm->rm_nrows; i++) { raidz_row_t *rr = rm->rm_row[i]; for (int c = 0; c < rr->rr_cols; c++) { raidz_col_t *rc = &rr->rr_col[c]; if (rc->rc_need_orig_restore) { abd_copy_from_buf(rc->rc_abd, rc->rc_orig_data, rc->rc_size); rc->rc_need_orig_restore = B_FALSE; } } } } /* * returns EINVAL if reconstruction of the block will not be possible * returns ECKSUM if this specific reconstruction failed * returns 0 on successful reconstruction */ static int raidz_reconstruct(zio_t *zio, int *ltgts, int ntgts, int nparity) { raidz_map_t *rm = zio->io_vsd; /* Reconstruct each row */ for (int r = 0; r < rm->rm_nrows; r++) { raidz_row_t *rr = rm->rm_row[r]; int my_tgts[VDEV_RAIDZ_MAXPARITY]; /* value is child id */ int t = 0; int dead = 0; int dead_data = 0; for (int c = 0; c < rr->rr_cols; c++) { raidz_col_t *rc = &rr->rr_col[c]; ASSERT0(rc->rc_need_orig_restore); if (rc->rc_error != 0) { dead++; if (c >= nparity) dead_data++; continue; } if (rc->rc_size == 0) continue; for (int lt = 0; lt < ntgts; lt++) { if (rc->rc_devidx == ltgts[lt]) { if (rc->rc_orig_data == NULL) { rc->rc_orig_data = zio_buf_alloc(rc->rc_size); abd_copy_to_buf( rc->rc_orig_data, rc->rc_abd, rc->rc_size); } rc->rc_need_orig_restore = B_TRUE; dead++; if (c >= nparity) dead_data++; my_tgts[t++] = c; break; } } } if (dead > nparity) { /* reconstruction not possible */ raidz_restore_orig_data(rm); return (EINVAL); } rr->rr_code = 0; if (dead_data > 0) rr->rr_code = vdev_raidz_reconstruct_row(rm, rr, my_tgts, t); } /* Check for success */ if (raidz_checksum_verify(zio) == 0) { /* Reconstruction succeeded - report errors */ for (int i = 0; i < rm->rm_nrows; i++) { raidz_row_t *rr = rm->rm_row[i]; for (int c = 0; c < rr->rr_cols; c++) { raidz_col_t *rc = &rr->rr_col[c]; if (rc->rc_need_orig_restore) { /* * Note: if this is a parity column, * we don't really know if it's wrong. * We need to let * vdev_raidz_io_done_verified() check * it, and if we set rc_error, it will * think that it is a "known" error * that doesn't need to be checked * or corrected. */ if (rc->rc_error == 0 && c >= rr->rr_firstdatacol) { raidz_checksum_error(zio, rc, rc->rc_gdata); rc->rc_error = SET_ERROR(ECKSUM); } rc->rc_need_orig_restore = B_FALSE; } } vdev_raidz_io_done_verified(zio, rr); } zio_checksum_verified(zio); return (0); } /* Reconstruction failed - restore original data */ raidz_restore_orig_data(rm); return (ECKSUM); } /* * Iterate over all combinations of N bad vdevs and attempt a reconstruction. * Note that the algorithm below is non-optimal because it doesn't take into * account how reconstruction is actually performed. For example, with * triple-parity RAID-Z the reconstruction procedure is the same if column 4 * is targeted as invalid as if columns 1 and 4 are targeted since in both * cases we'd only use parity information in column 0. * * The order that we find the various possible combinations of failed * disks is dictated by these rules: * - Examine each "slot" (the "i" in tgts[i]) * - Try to increment this slot (tgts[i] = tgts[i] + 1) * - if we can't increment because it runs into the next slot, * reset our slot to the minimum, and examine the next slot * * For example, with a 6-wide RAIDZ3, and no known errors (so we have to choose * 3 columns to reconstruct), we will generate the following sequence: * * STATE ACTION * 0 1 2 special case: skip since these are all parity * 0 1 3 first slot: reset to 0; middle slot: increment to 2 * 0 2 3 first slot: increment to 1 * 1 2 3 first: reset to 0; middle: reset to 1; last: increment to 4 * 0 1 4 first: reset to 0; middle: increment to 2 * 0 2 4 first: increment to 1 * 1 2 4 first: reset to 0; middle: increment to 3 * 0 3 4 first: increment to 1 * 1 3 4 first: increment to 2 * 2 3 4 first: reset to 0; middle: reset to 1; last: increment to 5 * 0 1 5 first: reset to 0; middle: increment to 2 * 0 2 5 first: increment to 1 * 1 2 5 first: reset to 0; middle: increment to 3 * 0 3 5 first: increment to 1 * 1 3 5 first: increment to 2 * 2 3 5 first: reset to 0; middle: increment to 4 * 0 4 5 first: increment to 1 * 1 4 5 first: increment to 2 * 2 4 5 first: increment to 3 * 3 4 5 done * * This strategy works for dRAID but is less effecient when there are a large * number of child vdevs and therefore permutations to check. Furthermore, * since the raidz_map_t rows likely do not overlap reconstruction would be * possible as long as there are no more than nparity data errors per row. * These additional permutations are not currently checked but could be as * a future improvement. */ static int vdev_raidz_combrec(zio_t *zio) { int nparity = vdev_get_nparity(zio->io_vd); raidz_map_t *rm = zio->io_vsd; /* Check if there's enough data to attempt reconstrution. */ for (int i = 0; i < rm->rm_nrows; i++) { raidz_row_t *rr = rm->rm_row[i]; int total_errors = 0; for (int c = 0; c < rr->rr_cols; c++) { if (rr->rr_col[c].rc_error) total_errors++; } if (total_errors > nparity) return (vdev_raidz_worst_error(rr)); } for (int num_failures = 1; num_failures <= nparity; num_failures++) { int tstore[VDEV_RAIDZ_MAXPARITY + 2]; int *ltgts = &tstore[1]; /* value is logical child ID */ /* Determine number of logical children, n */ int n = zio->io_vd->vdev_children; ASSERT3U(num_failures, <=, nparity); ASSERT3U(num_failures, <=, VDEV_RAIDZ_MAXPARITY); /* Handle corner cases in combrec logic */ ltgts[-1] = -1; for (int i = 0; i < num_failures; i++) { ltgts[i] = i; } ltgts[num_failures] = n; for (;;) { int err = raidz_reconstruct(zio, ltgts, num_failures, nparity); if (err == EINVAL) { /* * Reconstruction not possible with this # * failures; try more failures. */ break; } else if (err == 0) return (0); /* Compute next targets to try */ for (int t = 0; ; t++) { ASSERT3U(t, <, num_failures); ltgts[t]++; if (ltgts[t] == n) { /* try more failures */ ASSERT3U(t, ==, num_failures - 1); break; } ASSERT3U(ltgts[t], <, n); ASSERT3U(ltgts[t], <=, ltgts[t + 1]); /* * If that spot is available, we're done here. * Try the next combination. */ if (ltgts[t] != ltgts[t + 1]) break; /* * Otherwise, reset this tgt to the minimum, * and move on to the next tgt. */ ltgts[t] = ltgts[t - 1] + 1; ASSERT3U(ltgts[t], ==, t); } /* Increase the number of failures and keep trying. */ if (ltgts[num_failures - 1] == n) break; } } return (ECKSUM); } void vdev_raidz_reconstruct(raidz_map_t *rm, const int *t, int nt) { for (uint64_t row = 0; row < rm->rm_nrows; row++) { raidz_row_t *rr = rm->rm_row[row]; vdev_raidz_reconstruct_row(rm, rr, t, nt); } } /* * Complete a write IO operation on a RAIDZ VDev * * Outline: * 1. Check for errors on the child IOs. * 2. Return, setting an error code if too few child VDevs were written * to reconstruct the data later. Note that partial writes are * considered successful if they can be reconstructed at all. */ static void vdev_raidz_io_done_write_impl(zio_t *zio, raidz_row_t *rr) { int total_errors = 0; ASSERT3U(rr->rr_missingparity, <=, rr->rr_firstdatacol); ASSERT3U(rr->rr_missingdata, <=, rr->rr_cols - rr->rr_firstdatacol); ASSERT3U(zio->io_type, ==, ZIO_TYPE_WRITE); for (int c = 0; c < rr->rr_cols; c++) { raidz_col_t *rc = &rr->rr_col[c]; if (rc->rc_error) { ASSERT(rc->rc_error != ECKSUM); /* child has no bp */ total_errors++; } } /* * Treat partial writes as a success. If we couldn't write enough * columns to reconstruct the data, the I/O failed. Otherwise, * good enough. * * Now that we support write reallocation, it would be better * to treat partial failure as real failure unless there are * no non-degraded top-level vdevs left, and not update DTLs * if we intend to reallocate. */ if (total_errors > rr->rr_firstdatacol) { zio->io_error = zio_worst_error(zio->io_error, vdev_raidz_worst_error(rr)); } } /* * return 0 if no reconstruction occurred, otherwise the "code" from * vdev_raidz_reconstruct(). */ static int vdev_raidz_io_done_reconstruct_known_missing(zio_t *zio, raidz_map_t *rm, raidz_row_t *rr) { int parity_errors = 0; int parity_untried = 0; int data_errors = 0; int total_errors = 0; int code = 0; ASSERT3U(rr->rr_missingparity, <=, rr->rr_firstdatacol); ASSERT3U(rr->rr_missingdata, <=, rr->rr_cols - rr->rr_firstdatacol); ASSERT3U(zio->io_type, ==, ZIO_TYPE_READ); for (int c = 0; c < rr->rr_cols; c++) { raidz_col_t *rc = &rr->rr_col[c]; if (rc->rc_error) { ASSERT(rc->rc_error != ECKSUM); /* child has no bp */ if (c < rr->rr_firstdatacol) parity_errors++; else data_errors++; total_errors++; } else if (c < rr->rr_firstdatacol && !rc->rc_tried) { parity_untried++; } } /* * If there were data errors and the number of errors we saw was * correctable -- less than or equal to the number of parity disks read * -- reconstruct based on the missing data. */ if (data_errors != 0 && total_errors <= rr->rr_firstdatacol - parity_untried) { /* * We either attempt to read all the parity columns or * none of them. If we didn't try to read parity, we * wouldn't be here in the correctable case. There must * also have been fewer parity errors than parity * columns or, again, we wouldn't be in this code path. */ ASSERT(parity_untried == 0); ASSERT(parity_errors < rr->rr_firstdatacol); /* * Identify the data columns that reported an error. */ int n = 0; int tgts[VDEV_RAIDZ_MAXPARITY]; for (int c = rr->rr_firstdatacol; c < rr->rr_cols; c++) { raidz_col_t *rc = &rr->rr_col[c]; if (rc->rc_error != 0) { ASSERT(n < VDEV_RAIDZ_MAXPARITY); tgts[n++] = c; } } ASSERT(rr->rr_firstdatacol >= n); code = vdev_raidz_reconstruct_row(rm, rr, tgts, n); } return (code); } /* * Return the number of reads issued. */ static int vdev_raidz_read_all(zio_t *zio, raidz_row_t *rr) { vdev_t *vd = zio->io_vd; int nread = 0; rr->rr_missingdata = 0; rr->rr_missingparity = 0; /* * If this rows contains empty sectors which are not required * for a normal read then allocate an ABD for them now so they * may be read, verified, and any needed repairs performed. */ if (rr->rr_nempty && rr->rr_abd_empty == NULL) vdev_draid_map_alloc_empty(zio, rr); for (int c = 0; c < rr->rr_cols; c++) { raidz_col_t *rc = &rr->rr_col[c]; if (rc->rc_tried || rc->rc_size == 0) continue; zio_nowait(zio_vdev_child_io(zio, NULL, vd->vdev_child[rc->rc_devidx], rc->rc_offset, rc->rc_abd, rc->rc_size, zio->io_type, zio->io_priority, 0, vdev_raidz_child_done, rc)); nread++; } return (nread); } /* * We're here because either there were too many errors to even attempt * reconstruction (total_errors == rm_first_datacol), or vdev_*_combrec() * failed. In either case, there is enough bad data to prevent reconstruction. * Start checksum ereports for all children which haven't failed. */ static void vdev_raidz_io_done_unrecoverable(zio_t *zio) { raidz_map_t *rm = zio->io_vsd; for (int i = 0; i < rm->rm_nrows; i++) { raidz_row_t *rr = rm->rm_row[i]; for (int c = 0; c < rr->rr_cols; c++) { raidz_col_t *rc = &rr->rr_col[c]; vdev_t *cvd = zio->io_vd->vdev_child[rc->rc_devidx]; if (rc->rc_error != 0) continue; zio_bad_cksum_t zbc; zbc.zbc_has_cksum = 0; zbc.zbc_injected = rm->rm_ecksuminjected; int ret = zfs_ereport_start_checksum(zio->io_spa, cvd, &zio->io_bookmark, zio, rc->rc_offset, rc->rc_size, (void *)(uintptr_t)c, &zbc); if (ret != EALREADY) { mutex_enter(&cvd->vdev_stat_lock); cvd->vdev_stat.vs_checksum_errors++; mutex_exit(&cvd->vdev_stat_lock); } } } } void vdev_raidz_io_done(zio_t *zio) { raidz_map_t *rm = zio->io_vsd; if (zio->io_type == ZIO_TYPE_WRITE) { for (int i = 0; i < rm->rm_nrows; i++) { vdev_raidz_io_done_write_impl(zio, rm->rm_row[i]); } } else { for (int i = 0; i < rm->rm_nrows; i++) { raidz_row_t *rr = rm->rm_row[i]; rr->rr_code = vdev_raidz_io_done_reconstruct_known_missing(zio, rm, rr); } if (raidz_checksum_verify(zio) == 0) { for (int i = 0; i < rm->rm_nrows; i++) { raidz_row_t *rr = rm->rm_row[i]; vdev_raidz_io_done_verified(zio, rr); } zio_checksum_verified(zio); } else { /* * A sequential resilver has no checksum which makes * combinatoral reconstruction impossible. This code * path is unreachable since raidz_checksum_verify() * has no checksum to verify and must succeed. */ ASSERT3U(zio->io_priority, !=, ZIO_PRIORITY_REBUILD); /* * This isn't a typical situation -- either we got a * read error or a child silently returned bad data. * Read every block so we can try again with as much * data and parity as we can track down. If we've * already been through once before, all children will * be marked as tried so we'll proceed to combinatorial * reconstruction. */ int nread = 0; for (int i = 0; i < rm->rm_nrows; i++) { nread += vdev_raidz_read_all(zio, rm->rm_row[i]); } if (nread != 0) { /* * Normally our stage is VDEV_IO_DONE, but if * we've already called redone(), it will have * changed to VDEV_IO_START, in which case we * don't want to call redone() again. */ if (zio->io_stage != ZIO_STAGE_VDEV_IO_START) zio_vdev_io_redone(zio); return; } zio->io_error = vdev_raidz_combrec(zio); if (zio->io_error == ECKSUM && !(zio->io_flags & ZIO_FLAG_SPECULATIVE)) { vdev_raidz_io_done_unrecoverable(zio); } } } } static void vdev_raidz_state_change(vdev_t *vd, int faulted, int degraded) { vdev_raidz_t *vdrz = vd->vdev_tsd; if (faulted > vdrz->vd_nparity) vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN, VDEV_AUX_NO_REPLICAS); else if (degraded + faulted != 0) vdev_set_state(vd, B_FALSE, VDEV_STATE_DEGRADED, VDEV_AUX_NONE); else vdev_set_state(vd, B_FALSE, VDEV_STATE_HEALTHY, VDEV_AUX_NONE); } /* * Determine if any portion of the provided block resides on a child vdev * with a dirty DTL and therefore needs to be resilvered. The function * assumes that at least one DTL is dirty which implies that full stripe * width blocks must be resilvered. */ static boolean_t vdev_raidz_need_resilver(vdev_t *vd, const dva_t *dva, size_t psize, uint64_t phys_birth) { vdev_raidz_t *vdrz = vd->vdev_tsd; uint64_t dcols = vd->vdev_children; uint64_t nparity = vdrz->vd_nparity; uint64_t ashift = vd->vdev_top->vdev_ashift; /* The starting RAIDZ (parent) vdev sector of the block. */ uint64_t b = DVA_GET_OFFSET(dva) >> ashift; /* The zio's size in units of the vdev's minimum sector size. */ uint64_t s = ((psize - 1) >> ashift) + 1; /* The first column for this stripe. */ uint64_t f = b % dcols; /* Unreachable by sequential resilver. */ ASSERT3U(phys_birth, !=, TXG_UNKNOWN); if (!vdev_dtl_contains(vd, DTL_PARTIAL, phys_birth, 1)) return (B_FALSE); if (s + nparity >= dcols) return (B_TRUE); for (uint64_t c = 0; c < s + nparity; c++) { uint64_t devidx = (f + c) % dcols; vdev_t *cvd = vd->vdev_child[devidx]; /* * dsl_scan_need_resilver() already checked vd with * vdev_dtl_contains(). So here just check cvd with * vdev_dtl_empty(), cheaper and a good approximation. */ if (!vdev_dtl_empty(cvd, DTL_PARTIAL)) return (B_TRUE); } return (B_FALSE); } static void vdev_raidz_xlate(vdev_t *cvd, const range_seg64_t *logical_rs, range_seg64_t *physical_rs, range_seg64_t *remain_rs) { vdev_t *raidvd = cvd->vdev_parent; ASSERT(raidvd->vdev_ops == &vdev_raidz_ops); uint64_t width = raidvd->vdev_children; uint64_t tgt_col = cvd->vdev_id; uint64_t ashift = raidvd->vdev_top->vdev_ashift; /* make sure the offsets are block-aligned */ ASSERT0(logical_rs->rs_start % (1 << ashift)); ASSERT0(logical_rs->rs_end % (1 << ashift)); uint64_t b_start = logical_rs->rs_start >> ashift; uint64_t b_end = logical_rs->rs_end >> ashift; uint64_t start_row = 0; if (b_start > tgt_col) /* avoid underflow */ start_row = ((b_start - tgt_col - 1) / width) + 1; uint64_t end_row = 0; if (b_end > tgt_col) end_row = ((b_end - tgt_col - 1) / width) + 1; physical_rs->rs_start = start_row << ashift; physical_rs->rs_end = end_row << ashift; ASSERT3U(physical_rs->rs_start, <=, logical_rs->rs_start); ASSERT3U(physical_rs->rs_end - physical_rs->rs_start, <=, logical_rs->rs_end - logical_rs->rs_start); } /* * Initialize private RAIDZ specific fields from the nvlist. */ static int vdev_raidz_init(spa_t *spa, nvlist_t *nv, void **tsd) { vdev_raidz_t *vdrz; uint64_t nparity; uint_t children; nvlist_t **child; int error = nvlist_lookup_nvlist_array(nv, ZPOOL_CONFIG_CHILDREN, &child, &children); if (error != 0) return (SET_ERROR(EINVAL)); if (nvlist_lookup_uint64(nv, ZPOOL_CONFIG_NPARITY, &nparity) == 0) { if (nparity == 0 || nparity > VDEV_RAIDZ_MAXPARITY) return (SET_ERROR(EINVAL)); /* * Previous versions could only support 1 or 2 parity * device. */ if (nparity > 1 && spa_version(spa) < SPA_VERSION_RAIDZ2) return (SET_ERROR(EINVAL)); else if (nparity > 2 && spa_version(spa) < SPA_VERSION_RAIDZ3) return (SET_ERROR(EINVAL)); } else { /* * We require the parity to be specified for SPAs that * support multiple parity levels. */ if (spa_version(spa) >= SPA_VERSION_RAIDZ2) return (SET_ERROR(EINVAL)); /* * Otherwise, we default to 1 parity device for RAID-Z. */ nparity = 1; } vdrz = kmem_zalloc(sizeof (*vdrz), KM_SLEEP); vdrz->vd_logical_width = children; vdrz->vd_nparity = nparity; *tsd = vdrz; return (0); } static void vdev_raidz_fini(vdev_t *vd) { kmem_free(vd->vdev_tsd, sizeof (vdev_raidz_t)); } /* * Add RAIDZ specific fields to the config nvlist. */ static void vdev_raidz_config_generate(vdev_t *vd, nvlist_t *nv) { ASSERT3P(vd->vdev_ops, ==, &vdev_raidz_ops); vdev_raidz_t *vdrz = vd->vdev_tsd; /* * Make sure someone hasn't managed to sneak a fancy new vdev * into a crufty old storage pool. */ ASSERT(vdrz->vd_nparity == 1 || (vdrz->vd_nparity <= 2 && spa_version(vd->vdev_spa) >= SPA_VERSION_RAIDZ2) || (vdrz->vd_nparity <= 3 && spa_version(vd->vdev_spa) >= SPA_VERSION_RAIDZ3)); /* * Note that we'll add these even on storage pools where they * aren't strictly required -- older software will just ignore * it. */ fnvlist_add_uint64(nv, ZPOOL_CONFIG_NPARITY, vdrz->vd_nparity); } static uint64_t vdev_raidz_nparity(vdev_t *vd) { vdev_raidz_t *vdrz = vd->vdev_tsd; return (vdrz->vd_nparity); } static uint64_t vdev_raidz_ndisks(vdev_t *vd) { return (vd->vdev_children); } vdev_ops_t vdev_raidz_ops = { .vdev_op_init = vdev_raidz_init, .vdev_op_fini = vdev_raidz_fini, .vdev_op_open = vdev_raidz_open, .vdev_op_close = vdev_raidz_close, .vdev_op_asize = vdev_raidz_asize, .vdev_op_min_asize = vdev_raidz_min_asize, .vdev_op_min_alloc = NULL, .vdev_op_io_start = vdev_raidz_io_start, .vdev_op_io_done = vdev_raidz_io_done, .vdev_op_state_change = vdev_raidz_state_change, .vdev_op_need_resilver = vdev_raidz_need_resilver, .vdev_op_hold = NULL, .vdev_op_rele = NULL, .vdev_op_remap = NULL, .vdev_op_xlate = vdev_raidz_xlate, .vdev_op_rebuild_asize = NULL, .vdev_op_metaslab_init = NULL, .vdev_op_config_generate = vdev_raidz_config_generate, .vdev_op_nparity = vdev_raidz_nparity, .vdev_op_ndisks = vdev_raidz_ndisks, .vdev_op_type = VDEV_TYPE_RAIDZ, /* name of this vdev type */ .vdev_op_leaf = B_FALSE /* not a leaf vdev */ }; diff --git a/module/zfs/zil.c b/module/zfs/zil.c index 632fef29bff4..7b52f9249298 100644 --- a/module/zfs/zil.c +++ b/module/zfs/zil.c @@ -1,3695 +1,3695 @@ /* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. * Copyright (c) 2011, 2018 by Delphix. All rights reserved. * Copyright (c) 2014 Integros [integros.com] * Copyright (c) 2018 Datto Inc. */ /* Portions Copyright 2010 Robert Milkowski */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * The ZFS Intent Log (ZIL) saves "transaction records" (itxs) of system * calls that change the file system. Each itx has enough information to * be able to replay them after a system crash, power loss, or * equivalent failure mode. These are stored in memory until either: * * 1. they are committed to the pool by the DMU transaction group * (txg), at which point they can be discarded; or * 2. they are committed to the on-disk ZIL for the dataset being * modified (e.g. due to an fsync, O_DSYNC, or other synchronous * requirement). * * In the event of a crash or power loss, the itxs contained by each * dataset's on-disk ZIL will be replayed when that dataset is first * instantiated (e.g. if the dataset is a normal filesystem, when it is * first mounted). * * As hinted at above, there is one ZIL per dataset (both the in-memory * representation, and the on-disk representation). The on-disk format * consists of 3 parts: * * - a single, per-dataset, ZIL header; which points to a chain of * - zero or more ZIL blocks; each of which contains * - zero or more ZIL records * * A ZIL record holds the information necessary to replay a single * system call transaction. A ZIL block can hold many ZIL records, and * the blocks are chained together, similarly to a singly linked list. * * Each ZIL block contains a block pointer (blkptr_t) to the next ZIL * block in the chain, and the ZIL header points to the first block in * the chain. * * Note, there is not a fixed place in the pool to hold these ZIL * blocks; they are dynamically allocated and freed as needed from the * blocks available on the pool, though they can be preferentially * allocated from a dedicated "log" vdev. */ /* * This controls the amount of time that a ZIL block (lwb) will remain * "open" when it isn't "full", and it has a thread waiting for it to be * committed to stable storage. Please refer to the zil_commit_waiter() * function (and the comments within it) for more details. */ int zfs_commit_timeout_pct = 5; /* * See zil.h for more information about these fields. */ zil_stats_t zil_stats = { { "zil_commit_count", KSTAT_DATA_UINT64 }, { "zil_commit_writer_count", KSTAT_DATA_UINT64 }, { "zil_itx_count", KSTAT_DATA_UINT64 }, { "zil_itx_indirect_count", KSTAT_DATA_UINT64 }, { "zil_itx_indirect_bytes", KSTAT_DATA_UINT64 }, { "zil_itx_copied_count", KSTAT_DATA_UINT64 }, { "zil_itx_copied_bytes", KSTAT_DATA_UINT64 }, { "zil_itx_needcopy_count", KSTAT_DATA_UINT64 }, { "zil_itx_needcopy_bytes", KSTAT_DATA_UINT64 }, { "zil_itx_metaslab_normal_count", KSTAT_DATA_UINT64 }, { "zil_itx_metaslab_normal_bytes", KSTAT_DATA_UINT64 }, { "zil_itx_metaslab_slog_count", KSTAT_DATA_UINT64 }, { "zil_itx_metaslab_slog_bytes", KSTAT_DATA_UINT64 }, }; static kstat_t *zil_ksp; /* * Disable intent logging replay. This global ZIL switch affects all pools. */ int zil_replay_disable = 0; /* * Disable the DKIOCFLUSHWRITECACHE commands that are normally sent to * the disk(s) by the ZIL after an LWB write has completed. Setting this * will cause ZIL corruption on power loss if a volatile out-of-order * write cache is enabled. */ int zil_nocacheflush = 0; /* * Limit SLOG write size per commit executed with synchronous priority. * Any writes above that will be executed with lower (asynchronous) priority * to limit potential SLOG device abuse by single active ZIL writer. */ unsigned long zil_slog_bulk = 768 * 1024; static kmem_cache_t *zil_lwb_cache; static kmem_cache_t *zil_zcw_cache; #define LWB_EMPTY(lwb) ((BP_GET_LSIZE(&lwb->lwb_blk) - \ sizeof (zil_chain_t)) == (lwb->lwb_sz - lwb->lwb_nused)) static int zil_bp_compare(const void *x1, const void *x2) { const dva_t *dva1 = &((zil_bp_node_t *)x1)->zn_dva; const dva_t *dva2 = &((zil_bp_node_t *)x2)->zn_dva; int cmp = TREE_CMP(DVA_GET_VDEV(dva1), DVA_GET_VDEV(dva2)); if (likely(cmp)) return (cmp); return (TREE_CMP(DVA_GET_OFFSET(dva1), DVA_GET_OFFSET(dva2))); } static void zil_bp_tree_init(zilog_t *zilog) { avl_create(&zilog->zl_bp_tree, zil_bp_compare, sizeof (zil_bp_node_t), offsetof(zil_bp_node_t, zn_node)); } static void zil_bp_tree_fini(zilog_t *zilog) { avl_tree_t *t = &zilog->zl_bp_tree; zil_bp_node_t *zn; void *cookie = NULL; while ((zn = avl_destroy_nodes(t, &cookie)) != NULL) kmem_free(zn, sizeof (zil_bp_node_t)); avl_destroy(t); } int zil_bp_tree_add(zilog_t *zilog, const blkptr_t *bp) { avl_tree_t *t = &zilog->zl_bp_tree; const dva_t *dva; zil_bp_node_t *zn; avl_index_t where; if (BP_IS_EMBEDDED(bp)) return (0); dva = BP_IDENTITY(bp); if (avl_find(t, dva, &where) != NULL) return (SET_ERROR(EEXIST)); zn = kmem_alloc(sizeof (zil_bp_node_t), KM_SLEEP); zn->zn_dva = *dva; avl_insert(t, zn, where); return (0); } static zil_header_t * zil_header_in_syncing_context(zilog_t *zilog) { return ((zil_header_t *)zilog->zl_header); } static void zil_init_log_chain(zilog_t *zilog, blkptr_t *bp) { zio_cksum_t *zc = &bp->blk_cksum; zc->zc_word[ZIL_ZC_GUID_0] = spa_get_random(-1ULL); zc->zc_word[ZIL_ZC_GUID_1] = spa_get_random(-1ULL); zc->zc_word[ZIL_ZC_OBJSET] = dmu_objset_id(zilog->zl_os); zc->zc_word[ZIL_ZC_SEQ] = 1ULL; } /* * Read a log block and make sure it's valid. */ static int zil_read_log_block(zilog_t *zilog, boolean_t decrypt, const blkptr_t *bp, blkptr_t *nbp, void *dst, char **end) { enum zio_flag zio_flags = ZIO_FLAG_CANFAIL; arc_flags_t aflags = ARC_FLAG_WAIT; arc_buf_t *abuf = NULL; zbookmark_phys_t zb; int error; if (zilog->zl_header->zh_claim_txg == 0) zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; if (!(zilog->zl_header->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) zio_flags |= ZIO_FLAG_SPECULATIVE; if (!decrypt) zio_flags |= ZIO_FLAG_RAW; SET_BOOKMARK(&zb, bp->blk_cksum.zc_word[ZIL_ZC_OBJSET], ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]); error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); if (error == 0) { zio_cksum_t cksum = bp->blk_cksum; /* * Validate the checksummed log block. * * Sequence numbers should be... sequential. The checksum * verifier for the next block should be bp's checksum plus 1. * * Also check the log chain linkage and size used. */ cksum.zc_word[ZIL_ZC_SEQ]++; if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) { zil_chain_t *zilc = abuf->b_data; char *lr = (char *)(zilc + 1); uint64_t len = zilc->zc_nused - sizeof (zil_chain_t); if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum, sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk)) { error = SET_ERROR(ECKSUM); } else { ASSERT3U(len, <=, SPA_OLD_MAXBLOCKSIZE); bcopy(lr, dst, len); *end = (char *)dst + len; *nbp = zilc->zc_next_blk; } } else { char *lr = abuf->b_data; uint64_t size = BP_GET_LSIZE(bp); zil_chain_t *zilc = (zil_chain_t *)(lr + size) - 1; if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum, sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk) || (zilc->zc_nused > (size - sizeof (*zilc)))) { error = SET_ERROR(ECKSUM); } else { ASSERT3U(zilc->zc_nused, <=, SPA_OLD_MAXBLOCKSIZE); bcopy(lr, dst, zilc->zc_nused); *end = (char *)dst + zilc->zc_nused; *nbp = zilc->zc_next_blk; } } arc_buf_destroy(abuf, &abuf); } return (error); } /* * Read a TX_WRITE log data block. */ static int zil_read_log_data(zilog_t *zilog, const lr_write_t *lr, void *wbuf) { enum zio_flag zio_flags = ZIO_FLAG_CANFAIL; const blkptr_t *bp = &lr->lr_blkptr; arc_flags_t aflags = ARC_FLAG_WAIT; arc_buf_t *abuf = NULL; zbookmark_phys_t zb; int error; if (BP_IS_HOLE(bp)) { if (wbuf != NULL) bzero(wbuf, MAX(BP_GET_LSIZE(bp), lr->lr_length)); return (0); } if (zilog->zl_header->zh_claim_txg == 0) zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; /* * If we are not using the resulting data, we are just checking that * it hasn't been corrupted so we don't need to waste CPU time * decompressing and decrypting it. */ if (wbuf == NULL) zio_flags |= ZIO_FLAG_RAW; SET_BOOKMARK(&zb, dmu_objset_id(zilog->zl_os), lr->lr_foid, ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp)); error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); if (error == 0) { if (wbuf != NULL) bcopy(abuf->b_data, wbuf, arc_buf_size(abuf)); arc_buf_destroy(abuf, &abuf); } return (error); } /* * Parse the intent log, and call parse_func for each valid record within. */ int zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func, zil_parse_lr_func_t *parse_lr_func, void *arg, uint64_t txg, boolean_t decrypt) { const zil_header_t *zh = zilog->zl_header; boolean_t claimed = !!zh->zh_claim_txg; uint64_t claim_blk_seq = claimed ? zh->zh_claim_blk_seq : UINT64_MAX; uint64_t claim_lr_seq = claimed ? zh->zh_claim_lr_seq : UINT64_MAX; uint64_t max_blk_seq = 0; uint64_t max_lr_seq = 0; uint64_t blk_count = 0; uint64_t lr_count = 0; blkptr_t blk, next_blk; char *lrbuf, *lrp; int error = 0; bzero(&next_blk, sizeof (blkptr_t)); /* * Old logs didn't record the maximum zh_claim_lr_seq. */ if (!(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) claim_lr_seq = UINT64_MAX; /* * Starting at the block pointed to by zh_log we read the log chain. * For each block in the chain we strongly check that block to * ensure its validity. We stop when an invalid block is found. * For each block pointer in the chain we call parse_blk_func(). * For each record in each valid block we call parse_lr_func(). * If the log has been claimed, stop if we encounter a sequence * number greater than the highest claimed sequence number. */ lrbuf = zio_buf_alloc(SPA_OLD_MAXBLOCKSIZE); zil_bp_tree_init(zilog); for (blk = zh->zh_log; !BP_IS_HOLE(&blk); blk = next_blk) { uint64_t blk_seq = blk.blk_cksum.zc_word[ZIL_ZC_SEQ]; int reclen; char *end = NULL; if (blk_seq > claim_blk_seq) break; error = parse_blk_func(zilog, &blk, arg, txg); if (error != 0) break; ASSERT3U(max_blk_seq, <, blk_seq); max_blk_seq = blk_seq; blk_count++; if (max_lr_seq == claim_lr_seq && max_blk_seq == claim_blk_seq) break; error = zil_read_log_block(zilog, decrypt, &blk, &next_blk, lrbuf, &end); if (error != 0) break; for (lrp = lrbuf; lrp < end; lrp += reclen) { lr_t *lr = (lr_t *)lrp; reclen = lr->lrc_reclen; ASSERT3U(reclen, >=, sizeof (lr_t)); if (lr->lrc_seq > claim_lr_seq) goto done; error = parse_lr_func(zilog, lr, arg, txg); if (error != 0) goto done; ASSERT3U(max_lr_seq, <, lr->lrc_seq); max_lr_seq = lr->lrc_seq; lr_count++; } } done: zilog->zl_parse_error = error; zilog->zl_parse_blk_seq = max_blk_seq; zilog->zl_parse_lr_seq = max_lr_seq; zilog->zl_parse_blk_count = blk_count; zilog->zl_parse_lr_count = lr_count; ASSERT(!claimed || !(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID) || (max_blk_seq == claim_blk_seq && max_lr_seq == claim_lr_seq) || (decrypt && error == EIO)); zil_bp_tree_fini(zilog); zio_buf_free(lrbuf, SPA_OLD_MAXBLOCKSIZE); return (error); } /* ARGSUSED */ static int zil_clear_log_block(zilog_t *zilog, const blkptr_t *bp, void *tx, uint64_t first_txg) { ASSERT(!BP_IS_HOLE(bp)); /* * As we call this function from the context of a rewind to a * checkpoint, each ZIL block whose txg is later than the txg * that we rewind to is invalid. Thus, we return -1 so * zil_parse() doesn't attempt to read it. */ if (bp->blk_birth >= first_txg) return (-1); if (zil_bp_tree_add(zilog, bp) != 0) return (0); zio_free(zilog->zl_spa, first_txg, bp); return (0); } /* ARGSUSED */ static int zil_noop_log_record(zilog_t *zilog, const lr_t *lrc, void *tx, uint64_t first_txg) { return (0); } static int zil_claim_log_block(zilog_t *zilog, const blkptr_t *bp, void *tx, uint64_t first_txg) { /* * Claim log block if not already committed and not already claimed. * If tx == NULL, just verify that the block is claimable. */ if (BP_IS_HOLE(bp) || bp->blk_birth < first_txg || zil_bp_tree_add(zilog, bp) != 0) return (0); return (zio_wait(zio_claim(NULL, zilog->zl_spa, tx == NULL ? 0 : first_txg, bp, spa_claim_notify, NULL, ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB))); } static int zil_claim_log_record(zilog_t *zilog, const lr_t *lrc, void *tx, uint64_t first_txg) { lr_write_t *lr = (lr_write_t *)lrc; int error; if (lrc->lrc_txtype != TX_WRITE) return (0); /* * If the block is not readable, don't claim it. This can happen * in normal operation when a log block is written to disk before * some of the dmu_sync() blocks it points to. In this case, the * transaction cannot have been committed to anyone (we would have * waited for all writes to be stable first), so it is semantically * correct to declare this the end of the log. */ if (lr->lr_blkptr.blk_birth >= first_txg) { error = zil_read_log_data(zilog, lr, NULL); if (error != 0) return (error); } return (zil_claim_log_block(zilog, &lr->lr_blkptr, tx, first_txg)); } /* ARGSUSED */ static int zil_free_log_block(zilog_t *zilog, const blkptr_t *bp, void *tx, uint64_t claim_txg) { zio_free(zilog->zl_spa, dmu_tx_get_txg(tx), bp); return (0); } static int zil_free_log_record(zilog_t *zilog, const lr_t *lrc, void *tx, uint64_t claim_txg) { lr_write_t *lr = (lr_write_t *)lrc; blkptr_t *bp = &lr->lr_blkptr; /* * If we previously claimed it, we need to free it. */ if (claim_txg != 0 && lrc->lrc_txtype == TX_WRITE && bp->blk_birth >= claim_txg && zil_bp_tree_add(zilog, bp) == 0 && !BP_IS_HOLE(bp)) zio_free(zilog->zl_spa, dmu_tx_get_txg(tx), bp); return (0); } static int zil_lwb_vdev_compare(const void *x1, const void *x2) { const uint64_t v1 = ((zil_vdev_node_t *)x1)->zv_vdev; const uint64_t v2 = ((zil_vdev_node_t *)x2)->zv_vdev; return (TREE_CMP(v1, v2)); } static lwb_t * zil_alloc_lwb(zilog_t *zilog, blkptr_t *bp, boolean_t slog, uint64_t txg, boolean_t fastwrite) { lwb_t *lwb; lwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP); lwb->lwb_zilog = zilog; lwb->lwb_blk = *bp; lwb->lwb_fastwrite = fastwrite; lwb->lwb_slog = slog; lwb->lwb_state = LWB_STATE_CLOSED; lwb->lwb_buf = zio_buf_alloc(BP_GET_LSIZE(bp)); lwb->lwb_max_txg = txg; lwb->lwb_write_zio = NULL; lwb->lwb_root_zio = NULL; lwb->lwb_tx = NULL; lwb->lwb_issued_timestamp = 0; if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) { lwb->lwb_nused = sizeof (zil_chain_t); lwb->lwb_sz = BP_GET_LSIZE(bp); } else { lwb->lwb_nused = 0; lwb->lwb_sz = BP_GET_LSIZE(bp) - sizeof (zil_chain_t); } mutex_enter(&zilog->zl_lock); list_insert_tail(&zilog->zl_lwb_list, lwb); mutex_exit(&zilog->zl_lock); ASSERT(!MUTEX_HELD(&lwb->lwb_vdev_lock)); ASSERT(avl_is_empty(&lwb->lwb_vdev_tree)); VERIFY(list_is_empty(&lwb->lwb_waiters)); VERIFY(list_is_empty(&lwb->lwb_itxs)); return (lwb); } static void zil_free_lwb(zilog_t *zilog, lwb_t *lwb) { ASSERT(MUTEX_HELD(&zilog->zl_lock)); ASSERT(!MUTEX_HELD(&lwb->lwb_vdev_lock)); VERIFY(list_is_empty(&lwb->lwb_waiters)); VERIFY(list_is_empty(&lwb->lwb_itxs)); ASSERT(avl_is_empty(&lwb->lwb_vdev_tree)); ASSERT3P(lwb->lwb_write_zio, ==, NULL); ASSERT3P(lwb->lwb_root_zio, ==, NULL); ASSERT3U(lwb->lwb_max_txg, <=, spa_syncing_txg(zilog->zl_spa)); ASSERT(lwb->lwb_state == LWB_STATE_CLOSED || lwb->lwb_state == LWB_STATE_FLUSH_DONE); /* * Clear the zilog's field to indicate this lwb is no longer * valid, and prevent use-after-free errors. */ if (zilog->zl_last_lwb_opened == lwb) zilog->zl_last_lwb_opened = NULL; kmem_cache_free(zil_lwb_cache, lwb); } /* * Called when we create in-memory log transactions so that we know * to cleanup the itxs at the end of spa_sync(). */ static void zilog_dirty(zilog_t *zilog, uint64_t txg) { dsl_pool_t *dp = zilog->zl_dmu_pool; dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os); ASSERT(spa_writeable(zilog->zl_spa)); if (ds->ds_is_snapshot) panic("dirtying snapshot!"); if (txg_list_add(&dp->dp_dirty_zilogs, zilog, txg)) { /* up the hold count until we can be written out */ dmu_buf_add_ref(ds->ds_dbuf, zilog); zilog->zl_dirty_max_txg = MAX(txg, zilog->zl_dirty_max_txg); } } /* * Determine if the zil is dirty in the specified txg. Callers wanting to * ensure that the dirty state does not change must hold the itxg_lock for * the specified txg. Holding the lock will ensure that the zil cannot be * dirtied (zil_itx_assign) or cleaned (zil_clean) while we check its current * state. */ static boolean_t __maybe_unused zilog_is_dirty_in_txg(zilog_t *zilog, uint64_t txg) { dsl_pool_t *dp = zilog->zl_dmu_pool; if (txg_list_member(&dp->dp_dirty_zilogs, zilog, txg & TXG_MASK)) return (B_TRUE); return (B_FALSE); } /* * Determine if the zil is dirty. The zil is considered dirty if it has * any pending itx records that have not been cleaned by zil_clean(). */ static boolean_t zilog_is_dirty(zilog_t *zilog) { dsl_pool_t *dp = zilog->zl_dmu_pool; for (int t = 0; t < TXG_SIZE; t++) { if (txg_list_member(&dp->dp_dirty_zilogs, zilog, t)) return (B_TRUE); } return (B_FALSE); } /* * Create an on-disk intent log. */ static lwb_t * zil_create(zilog_t *zilog) { const zil_header_t *zh = zilog->zl_header; lwb_t *lwb = NULL; uint64_t txg = 0; dmu_tx_t *tx = NULL; blkptr_t blk; int error = 0; boolean_t fastwrite = FALSE; boolean_t slog = FALSE; /* * Wait for any previous destroy to complete. */ txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); ASSERT(zh->zh_claim_txg == 0); ASSERT(zh->zh_replay_seq == 0); blk = zh->zh_log; /* * Allocate an initial log block if: * - there isn't one already * - the existing block is the wrong endianness */ if (BP_IS_HOLE(&blk) || BP_SHOULD_BYTESWAP(&blk)) { tx = dmu_tx_create(zilog->zl_os); VERIFY0(dmu_tx_assign(tx, TXG_WAIT)); dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); txg = dmu_tx_get_txg(tx); if (!BP_IS_HOLE(&blk)) { zio_free(zilog->zl_spa, txg, &blk); BP_ZERO(&blk); } error = zio_alloc_zil(zilog->zl_spa, zilog->zl_os, txg, &blk, ZIL_MIN_BLKSZ, &slog); fastwrite = TRUE; if (error == 0) zil_init_log_chain(zilog, &blk); } /* * Allocate a log write block (lwb) for the first log block. */ if (error == 0) lwb = zil_alloc_lwb(zilog, &blk, slog, txg, fastwrite); /* * If we just allocated the first log block, commit our transaction * and wait for zil_sync() to stuff the block pointer into zh_log. * (zh is part of the MOS, so we cannot modify it in open context.) */ if (tx != NULL) { dmu_tx_commit(tx); txg_wait_synced(zilog->zl_dmu_pool, txg); } ASSERT(error != 0 || bcmp(&blk, &zh->zh_log, sizeof (blk)) == 0); IMPLY(error == 0, lwb != NULL); return (lwb); } /* * In one tx, free all log blocks and clear the log header. If keep_first * is set, then we're replaying a log with no content. We want to keep the * first block, however, so that the first synchronous transaction doesn't * require a txg_wait_synced() in zil_create(). We don't need to * txg_wait_synced() here either when keep_first is set, because both * zil_create() and zil_destroy() will wait for any in-progress destroys * to complete. */ void zil_destroy(zilog_t *zilog, boolean_t keep_first) { const zil_header_t *zh = zilog->zl_header; lwb_t *lwb; dmu_tx_t *tx; uint64_t txg; /* * Wait for any previous destroy to complete. */ txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); zilog->zl_old_header = *zh; /* debugging aid */ if (BP_IS_HOLE(&zh->zh_log)) return; tx = dmu_tx_create(zilog->zl_os); VERIFY0(dmu_tx_assign(tx, TXG_WAIT)); dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); txg = dmu_tx_get_txg(tx); mutex_enter(&zilog->zl_lock); ASSERT3U(zilog->zl_destroy_txg, <, txg); zilog->zl_destroy_txg = txg; zilog->zl_keep_first = keep_first; if (!list_is_empty(&zilog->zl_lwb_list)) { ASSERT(zh->zh_claim_txg == 0); VERIFY(!keep_first); while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { if (lwb->lwb_fastwrite) metaslab_fastwrite_unmark(zilog->zl_spa, &lwb->lwb_blk); list_remove(&zilog->zl_lwb_list, lwb); if (lwb->lwb_buf != NULL) zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); zio_free(zilog->zl_spa, txg, &lwb->lwb_blk); zil_free_lwb(zilog, lwb); } } else if (!keep_first) { zil_destroy_sync(zilog, tx); } mutex_exit(&zilog->zl_lock); dmu_tx_commit(tx); } void zil_destroy_sync(zilog_t *zilog, dmu_tx_t *tx) { ASSERT(list_is_empty(&zilog->zl_lwb_list)); (void) zil_parse(zilog, zil_free_log_block, zil_free_log_record, tx, zilog->zl_header->zh_claim_txg, B_FALSE); } int zil_claim(dsl_pool_t *dp, dsl_dataset_t *ds, void *txarg) { dmu_tx_t *tx = txarg; zilog_t *zilog; uint64_t first_txg; zil_header_t *zh; objset_t *os; int error; error = dmu_objset_own_obj(dp, ds->ds_object, DMU_OST_ANY, B_FALSE, B_FALSE, FTAG, &os); if (error != 0) { /* * EBUSY indicates that the objset is inconsistent, in which * case it can not have a ZIL. */ if (error != EBUSY) { cmn_err(CE_WARN, "can't open objset for %llu, error %u", (unsigned long long)ds->ds_object, error); } return (0); } zilog = dmu_objset_zil(os); zh = zil_header_in_syncing_context(zilog); ASSERT3U(tx->tx_txg, ==, spa_first_txg(zilog->zl_spa)); first_txg = spa_min_claim_txg(zilog->zl_spa); /* * If the spa_log_state is not set to be cleared, check whether * the current uberblock is a checkpoint one and if the current * header has been claimed before moving on. * * If the current uberblock is a checkpointed uberblock then * one of the following scenarios took place: * * 1] We are currently rewinding to the checkpoint of the pool. * 2] We crashed in the middle of a checkpoint rewind but we * did manage to write the checkpointed uberblock to the * vdev labels, so when we tried to import the pool again * the checkpointed uberblock was selected from the import * procedure. * * In both cases we want to zero out all the ZIL blocks, except * the ones that have been claimed at the time of the checkpoint * (their zh_claim_txg != 0). The reason is that these blocks * may be corrupted since we may have reused their locations on * disk after we took the checkpoint. * * We could try to set spa_log_state to SPA_LOG_CLEAR earlier * when we first figure out whether the current uberblock is * checkpointed or not. Unfortunately, that would discard all * the logs, including the ones that are claimed, and we would * leak space. */ if (spa_get_log_state(zilog->zl_spa) == SPA_LOG_CLEAR || (zilog->zl_spa->spa_uberblock.ub_checkpoint_txg != 0 && zh->zh_claim_txg == 0)) { if (!BP_IS_HOLE(&zh->zh_log)) { (void) zil_parse(zilog, zil_clear_log_block, zil_noop_log_record, tx, first_txg, B_FALSE); } BP_ZERO(&zh->zh_log); if (os->os_encrypted) os->os_next_write_raw[tx->tx_txg & TXG_MASK] = B_TRUE; dsl_dataset_dirty(dmu_objset_ds(os), tx); dmu_objset_disown(os, B_FALSE, FTAG); return (0); } /* * If we are not rewinding and opening the pool normally, then * the min_claim_txg should be equal to the first txg of the pool. */ ASSERT3U(first_txg, ==, spa_first_txg(zilog->zl_spa)); /* * Claim all log blocks if we haven't already done so, and remember * the highest claimed sequence number. This ensures that if we can * read only part of the log now (e.g. due to a missing device), * but we can read the entire log later, we will not try to replay * or destroy beyond the last block we successfully claimed. */ ASSERT3U(zh->zh_claim_txg, <=, first_txg); if (zh->zh_claim_txg == 0 && !BP_IS_HOLE(&zh->zh_log)) { (void) zil_parse(zilog, zil_claim_log_block, zil_claim_log_record, tx, first_txg, B_FALSE); zh->zh_claim_txg = first_txg; zh->zh_claim_blk_seq = zilog->zl_parse_blk_seq; zh->zh_claim_lr_seq = zilog->zl_parse_lr_seq; if (zilog->zl_parse_lr_count || zilog->zl_parse_blk_count > 1) zh->zh_flags |= ZIL_REPLAY_NEEDED; zh->zh_flags |= ZIL_CLAIM_LR_SEQ_VALID; if (os->os_encrypted) os->os_next_write_raw[tx->tx_txg & TXG_MASK] = B_TRUE; dsl_dataset_dirty(dmu_objset_ds(os), tx); } ASSERT3U(first_txg, ==, (spa_last_synced_txg(zilog->zl_spa) + 1)); dmu_objset_disown(os, B_FALSE, FTAG); return (0); } /* * Check the log by walking the log chain. * Checksum errors are ok as they indicate the end of the chain. * Any other error (no device or read failure) returns an error. */ /* ARGSUSED */ int zil_check_log_chain(dsl_pool_t *dp, dsl_dataset_t *ds, void *tx) { zilog_t *zilog; objset_t *os; blkptr_t *bp; int error; ASSERT(tx == NULL); error = dmu_objset_from_ds(ds, &os); if (error != 0) { cmn_err(CE_WARN, "can't open objset %llu, error %d", (unsigned long long)ds->ds_object, error); return (0); } zilog = dmu_objset_zil(os); bp = (blkptr_t *)&zilog->zl_header->zh_log; if (!BP_IS_HOLE(bp)) { vdev_t *vd; boolean_t valid = B_TRUE; /* * Check the first block and determine if it's on a log device * which may have been removed or faulted prior to loading this * pool. If so, there's no point in checking the rest of the * log as its content should have already been synced to the * pool. */ spa_config_enter(os->os_spa, SCL_STATE, FTAG, RW_READER); vd = vdev_lookup_top(os->os_spa, DVA_GET_VDEV(&bp->blk_dva[0])); if (vd->vdev_islog && vdev_is_dead(vd)) valid = vdev_log_state_valid(vd); spa_config_exit(os->os_spa, SCL_STATE, FTAG); if (!valid) return (0); /* * Check whether the current uberblock is checkpointed (e.g. * we are rewinding) and whether the current header has been * claimed or not. If it hasn't then skip verifying it. We * do this because its ZIL blocks may be part of the pool's * state before the rewind, which is no longer valid. */ zil_header_t *zh = zil_header_in_syncing_context(zilog); if (zilog->zl_spa->spa_uberblock.ub_checkpoint_txg != 0 && zh->zh_claim_txg == 0) return (0); } /* * Because tx == NULL, zil_claim_log_block() will not actually claim * any blocks, but just determine whether it is possible to do so. * In addition to checking the log chain, zil_claim_log_block() * will invoke zio_claim() with a done func of spa_claim_notify(), * which will update spa_max_claim_txg. See spa_load() for details. */ error = zil_parse(zilog, zil_claim_log_block, zil_claim_log_record, tx, zilog->zl_header->zh_claim_txg ? -1ULL : spa_min_claim_txg(os->os_spa), B_FALSE); return ((error == ECKSUM || error == ENOENT) ? 0 : error); } /* * When an itx is "skipped", this function is used to properly mark the * waiter as "done, and signal any thread(s) waiting on it. An itx can * be skipped (and not committed to an lwb) for a variety of reasons, * one of them being that the itx was committed via spa_sync(), prior to * it being committed to an lwb; this can happen if a thread calling * zil_commit() is racing with spa_sync(). */ static void zil_commit_waiter_skip(zil_commit_waiter_t *zcw) { mutex_enter(&zcw->zcw_lock); ASSERT3B(zcw->zcw_done, ==, B_FALSE); zcw->zcw_done = B_TRUE; cv_broadcast(&zcw->zcw_cv); mutex_exit(&zcw->zcw_lock); } /* * This function is used when the given waiter is to be linked into an * lwb's "lwb_waiter" list; i.e. when the itx is committed to the lwb. * At this point, the waiter will no longer be referenced by the itx, * and instead, will be referenced by the lwb. */ static void zil_commit_waiter_link_lwb(zil_commit_waiter_t *zcw, lwb_t *lwb) { /* * The lwb_waiters field of the lwb is protected by the zilog's * zl_lock, thus it must be held when calling this function. */ ASSERT(MUTEX_HELD(&lwb->lwb_zilog->zl_lock)); mutex_enter(&zcw->zcw_lock); ASSERT(!list_link_active(&zcw->zcw_node)); ASSERT3P(zcw->zcw_lwb, ==, NULL); ASSERT3P(lwb, !=, NULL); ASSERT(lwb->lwb_state == LWB_STATE_OPENED || lwb->lwb_state == LWB_STATE_ISSUED || lwb->lwb_state == LWB_STATE_WRITE_DONE); list_insert_tail(&lwb->lwb_waiters, zcw); zcw->zcw_lwb = lwb; mutex_exit(&zcw->zcw_lock); } /* * This function is used when zio_alloc_zil() fails to allocate a ZIL * block, and the given waiter must be linked to the "nolwb waiters" * list inside of zil_process_commit_list(). */ static void zil_commit_waiter_link_nolwb(zil_commit_waiter_t *zcw, list_t *nolwb) { mutex_enter(&zcw->zcw_lock); ASSERT(!list_link_active(&zcw->zcw_node)); ASSERT3P(zcw->zcw_lwb, ==, NULL); list_insert_tail(nolwb, zcw); mutex_exit(&zcw->zcw_lock); } void zil_lwb_add_block(lwb_t *lwb, const blkptr_t *bp) { avl_tree_t *t = &lwb->lwb_vdev_tree; avl_index_t where; zil_vdev_node_t *zv, zvsearch; int ndvas = BP_GET_NDVAS(bp); int i; if (zil_nocacheflush) return; mutex_enter(&lwb->lwb_vdev_lock); for (i = 0; i < ndvas; i++) { zvsearch.zv_vdev = DVA_GET_VDEV(&bp->blk_dva[i]); if (avl_find(t, &zvsearch, &where) == NULL) { zv = kmem_alloc(sizeof (*zv), KM_SLEEP); zv->zv_vdev = zvsearch.zv_vdev; avl_insert(t, zv, where); } } mutex_exit(&lwb->lwb_vdev_lock); } static void zil_lwb_flush_defer(lwb_t *lwb, lwb_t *nlwb) { avl_tree_t *src = &lwb->lwb_vdev_tree; avl_tree_t *dst = &nlwb->lwb_vdev_tree; void *cookie = NULL; zil_vdev_node_t *zv; ASSERT3S(lwb->lwb_state, ==, LWB_STATE_WRITE_DONE); ASSERT3S(nlwb->lwb_state, !=, LWB_STATE_WRITE_DONE); ASSERT3S(nlwb->lwb_state, !=, LWB_STATE_FLUSH_DONE); /* * While 'lwb' is at a point in its lifetime where lwb_vdev_tree does * not need the protection of lwb_vdev_lock (it will only be modified * while holding zilog->zl_lock) as its writes and those of its * children have all completed. The younger 'nlwb' may be waiting on * future writes to additional vdevs. */ mutex_enter(&nlwb->lwb_vdev_lock); /* * Tear down the 'lwb' vdev tree, ensuring that entries which do not * exist in 'nlwb' are moved to it, freeing any would-be duplicates. */ while ((zv = avl_destroy_nodes(src, &cookie)) != NULL) { avl_index_t where; if (avl_find(dst, zv, &where) == NULL) { avl_insert(dst, zv, where); } else { kmem_free(zv, sizeof (*zv)); } } mutex_exit(&nlwb->lwb_vdev_lock); } void zil_lwb_add_txg(lwb_t *lwb, uint64_t txg) { lwb->lwb_max_txg = MAX(lwb->lwb_max_txg, txg); } /* * This function is a called after all vdevs associated with a given lwb * write have completed their DKIOCFLUSHWRITECACHE command; or as soon * as the lwb write completes, if "zil_nocacheflush" is set. Further, * all "previous" lwb's will have completed before this function is * called; i.e. this function is called for all previous lwbs before * it's called for "this" lwb (enforced via zio the dependencies * configured in zil_lwb_set_zio_dependency()). * * The intention is for this function to be called as soon as the * contents of an lwb are considered "stable" on disk, and will survive * any sudden loss of power. At this point, any threads waiting for the * lwb to reach this state are signalled, and the "waiter" structures * are marked "done". */ static void zil_lwb_flush_vdevs_done(zio_t *zio) { lwb_t *lwb = zio->io_private; zilog_t *zilog = lwb->lwb_zilog; dmu_tx_t *tx = lwb->lwb_tx; zil_commit_waiter_t *zcw; itx_t *itx; spa_config_exit(zilog->zl_spa, SCL_STATE, lwb); zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); mutex_enter(&zilog->zl_lock); /* * Ensure the lwb buffer pointer is cleared before releasing the * txg. If we have had an allocation failure and the txg is * waiting to sync then we want zil_sync() to remove the lwb so * that it's not picked up as the next new one in * zil_process_commit_list(). zil_sync() will only remove the * lwb if lwb_buf is null. */ lwb->lwb_buf = NULL; lwb->lwb_tx = NULL; ASSERT3U(lwb->lwb_issued_timestamp, >, 0); zilog->zl_last_lwb_latency = gethrtime() - lwb->lwb_issued_timestamp; lwb->lwb_root_zio = NULL; ASSERT3S(lwb->lwb_state, ==, LWB_STATE_WRITE_DONE); lwb->lwb_state = LWB_STATE_FLUSH_DONE; if (zilog->zl_last_lwb_opened == lwb) { /* * Remember the highest committed log sequence number * for ztest. We only update this value when all the log * writes succeeded, because ztest wants to ASSERT that * it got the whole log chain. */ zilog->zl_commit_lr_seq = zilog->zl_lr_seq; } while ((itx = list_head(&lwb->lwb_itxs)) != NULL) { list_remove(&lwb->lwb_itxs, itx); zil_itx_destroy(itx); } while ((zcw = list_head(&lwb->lwb_waiters)) != NULL) { mutex_enter(&zcw->zcw_lock); ASSERT(list_link_active(&zcw->zcw_node)); list_remove(&lwb->lwb_waiters, zcw); ASSERT3P(zcw->zcw_lwb, ==, lwb); zcw->zcw_lwb = NULL; zcw->zcw_zio_error = zio->io_error; ASSERT3B(zcw->zcw_done, ==, B_FALSE); zcw->zcw_done = B_TRUE; cv_broadcast(&zcw->zcw_cv); mutex_exit(&zcw->zcw_lock); } mutex_exit(&zilog->zl_lock); /* * Now that we've written this log block, we have a stable pointer * to the next block in the chain, so it's OK to let the txg in * which we allocated the next block sync. */ dmu_tx_commit(tx); } /* * This is called when an lwb's write zio completes. The callback's * purpose is to issue the DKIOCFLUSHWRITECACHE commands for the vdevs * in the lwb's lwb_vdev_tree. The tree will contain the vdevs involved * in writing out this specific lwb's data, and in the case that cache * flushes have been deferred, vdevs involved in writing the data for * previous lwbs. The writes corresponding to all the vdevs in the * lwb_vdev_tree will have completed by the time this is called, due to * the zio dependencies configured in zil_lwb_set_zio_dependency(), * which takes deferred flushes into account. The lwb will be "done" * once zil_lwb_flush_vdevs_done() is called, which occurs in the zio * completion callback for the lwb's root zio. */ static void zil_lwb_write_done(zio_t *zio) { lwb_t *lwb = zio->io_private; spa_t *spa = zio->io_spa; zilog_t *zilog = lwb->lwb_zilog; avl_tree_t *t = &lwb->lwb_vdev_tree; void *cookie = NULL; zil_vdev_node_t *zv; lwb_t *nlwb; ASSERT3S(spa_config_held(spa, SCL_STATE, RW_READER), !=, 0); ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); ASSERT(BP_GET_TYPE(zio->io_bp) == DMU_OT_INTENT_LOG); ASSERT(BP_GET_LEVEL(zio->io_bp) == 0); ASSERT(BP_GET_BYTEORDER(zio->io_bp) == ZFS_HOST_BYTEORDER); ASSERT(!BP_IS_GANG(zio->io_bp)); ASSERT(!BP_IS_HOLE(zio->io_bp)); ASSERT(BP_GET_FILL(zio->io_bp) == 0); - abd_put(zio->io_abd); + abd_free(zio->io_abd); mutex_enter(&zilog->zl_lock); ASSERT3S(lwb->lwb_state, ==, LWB_STATE_ISSUED); lwb->lwb_state = LWB_STATE_WRITE_DONE; lwb->lwb_write_zio = NULL; lwb->lwb_fastwrite = FALSE; nlwb = list_next(&zilog->zl_lwb_list, lwb); mutex_exit(&zilog->zl_lock); if (avl_numnodes(t) == 0) return; /* * If there was an IO error, we're not going to call zio_flush() * on these vdevs, so we simply empty the tree and free the * nodes. We avoid calling zio_flush() since there isn't any * good reason for doing so, after the lwb block failed to be * written out. */ if (zio->io_error != 0) { while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) kmem_free(zv, sizeof (*zv)); return; } /* * If this lwb does not have any threads waiting for it to * complete, we want to defer issuing the DKIOCFLUSHWRITECACHE * command to the vdevs written to by "this" lwb, and instead * rely on the "next" lwb to handle the DKIOCFLUSHWRITECACHE * command for those vdevs. Thus, we merge the vdev tree of * "this" lwb with the vdev tree of the "next" lwb in the list, * and assume the "next" lwb will handle flushing the vdevs (or * deferring the flush(s) again). * * This is a useful performance optimization, especially for * workloads with lots of async write activity and few sync * write and/or fsync activity, as it has the potential to * coalesce multiple flush commands to a vdev into one. */ if (list_head(&lwb->lwb_waiters) == NULL && nlwb != NULL) { zil_lwb_flush_defer(lwb, nlwb); ASSERT(avl_is_empty(&lwb->lwb_vdev_tree)); return; } while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) { vdev_t *vd = vdev_lookup_top(spa, zv->zv_vdev); if (vd != NULL) zio_flush(lwb->lwb_root_zio, vd); kmem_free(zv, sizeof (*zv)); } } static void zil_lwb_set_zio_dependency(zilog_t *zilog, lwb_t *lwb) { lwb_t *last_lwb_opened = zilog->zl_last_lwb_opened; ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); ASSERT(MUTEX_HELD(&zilog->zl_lock)); /* * The zilog's "zl_last_lwb_opened" field is used to build the * lwb/zio dependency chain, which is used to preserve the * ordering of lwb completions that is required by the semantics * of the ZIL. Each new lwb zio becomes a parent of the * "previous" lwb zio, such that the new lwb's zio cannot * complete until the "previous" lwb's zio completes. * * This is required by the semantics of zil_commit(); the commit * waiters attached to the lwbs will be woken in the lwb zio's * completion callback, so this zio dependency graph ensures the * waiters are woken in the correct order (the same order the * lwbs were created). */ if (last_lwb_opened != NULL && last_lwb_opened->lwb_state != LWB_STATE_FLUSH_DONE) { ASSERT(last_lwb_opened->lwb_state == LWB_STATE_OPENED || last_lwb_opened->lwb_state == LWB_STATE_ISSUED || last_lwb_opened->lwb_state == LWB_STATE_WRITE_DONE); ASSERT3P(last_lwb_opened->lwb_root_zio, !=, NULL); zio_add_child(lwb->lwb_root_zio, last_lwb_opened->lwb_root_zio); /* * If the previous lwb's write hasn't already completed, * we also want to order the completion of the lwb write * zios (above, we only order the completion of the lwb * root zios). This is required because of how we can * defer the DKIOCFLUSHWRITECACHE commands for each lwb. * * When the DKIOCFLUSHWRITECACHE commands are deferred, * the previous lwb will rely on this lwb to flush the * vdevs written to by that previous lwb. Thus, we need * to ensure this lwb doesn't issue the flush until * after the previous lwb's write completes. We ensure * this ordering by setting the zio parent/child * relationship here. * * Without this relationship on the lwb's write zio, * it's possible for this lwb's write to complete prior * to the previous lwb's write completing; and thus, the * vdevs for the previous lwb would be flushed prior to * that lwb's data being written to those vdevs (the * vdevs are flushed in the lwb write zio's completion * handler, zil_lwb_write_done()). */ if (last_lwb_opened->lwb_state != LWB_STATE_WRITE_DONE) { ASSERT(last_lwb_opened->lwb_state == LWB_STATE_OPENED || last_lwb_opened->lwb_state == LWB_STATE_ISSUED); ASSERT3P(last_lwb_opened->lwb_write_zio, !=, NULL); zio_add_child(lwb->lwb_write_zio, last_lwb_opened->lwb_write_zio); } } } /* * This function's purpose is to "open" an lwb such that it is ready to * accept new itxs being committed to it. To do this, the lwb's zio * structures are created, and linked to the lwb. This function is * idempotent; if the passed in lwb has already been opened, this * function is essentially a no-op. */ static void zil_lwb_write_open(zilog_t *zilog, lwb_t *lwb) { zbookmark_phys_t zb; zio_priority_t prio; ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); ASSERT3P(lwb, !=, NULL); EQUIV(lwb->lwb_root_zio == NULL, lwb->lwb_state == LWB_STATE_CLOSED); EQUIV(lwb->lwb_root_zio != NULL, lwb->lwb_state == LWB_STATE_OPENED); SET_BOOKMARK(&zb, lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_OBJSET], ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_SEQ]); /* Lock so zil_sync() doesn't fastwrite_unmark after zio is created */ mutex_enter(&zilog->zl_lock); if (lwb->lwb_root_zio == NULL) { abd_t *lwb_abd = abd_get_from_buf(lwb->lwb_buf, BP_GET_LSIZE(&lwb->lwb_blk)); if (!lwb->lwb_fastwrite) { metaslab_fastwrite_mark(zilog->zl_spa, &lwb->lwb_blk); lwb->lwb_fastwrite = 1; } if (!lwb->lwb_slog || zilog->zl_cur_used <= zil_slog_bulk) prio = ZIO_PRIORITY_SYNC_WRITE; else prio = ZIO_PRIORITY_ASYNC_WRITE; lwb->lwb_root_zio = zio_root(zilog->zl_spa, zil_lwb_flush_vdevs_done, lwb, ZIO_FLAG_CANFAIL); ASSERT3P(lwb->lwb_root_zio, !=, NULL); lwb->lwb_write_zio = zio_rewrite(lwb->lwb_root_zio, zilog->zl_spa, 0, &lwb->lwb_blk, lwb_abd, BP_GET_LSIZE(&lwb->lwb_blk), zil_lwb_write_done, lwb, prio, ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_FASTWRITE, &zb); ASSERT3P(lwb->lwb_write_zio, !=, NULL); lwb->lwb_state = LWB_STATE_OPENED; zil_lwb_set_zio_dependency(zilog, lwb); zilog->zl_last_lwb_opened = lwb; } mutex_exit(&zilog->zl_lock); ASSERT3P(lwb->lwb_root_zio, !=, NULL); ASSERT3P(lwb->lwb_write_zio, !=, NULL); ASSERT3S(lwb->lwb_state, ==, LWB_STATE_OPENED); } /* * Define a limited set of intent log block sizes. * * These must be a multiple of 4KB. Note only the amount used (again * aligned to 4KB) actually gets written. However, we can't always just * allocate SPA_OLD_MAXBLOCKSIZE as the slog space could be exhausted. */ struct { uint64_t limit; uint64_t blksz; } zil_block_buckets[] = { { 4096, 4096 }, /* non TX_WRITE */ { 8192 + 4096, 8192 + 4096 }, /* database */ { 32768 + 4096, 32768 + 4096 }, /* NFS writes */ { 65536 + 4096, 65536 + 4096 }, /* 64KB writes */ { 131072, 131072 }, /* < 128KB writes */ { 131072 +4096, 65536 + 4096 }, /* 128KB writes */ { UINT64_MAX, SPA_OLD_MAXBLOCKSIZE}, /* > 128KB writes */ }; /* * Maximum block size used by the ZIL. This is picked up when the ZIL is * initialized. Otherwise this should not be used directly; see * zl_max_block_size instead. */ int zil_maxblocksize = SPA_OLD_MAXBLOCKSIZE; /* * Start a log block write and advance to the next log block. * Calls are serialized. */ static lwb_t * zil_lwb_write_issue(zilog_t *zilog, lwb_t *lwb) { lwb_t *nlwb = NULL; zil_chain_t *zilc; spa_t *spa = zilog->zl_spa; blkptr_t *bp; dmu_tx_t *tx; uint64_t txg; uint64_t zil_blksz, wsz; int i, error; boolean_t slog; ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); ASSERT3P(lwb->lwb_root_zio, !=, NULL); ASSERT3P(lwb->lwb_write_zio, !=, NULL); ASSERT3S(lwb->lwb_state, ==, LWB_STATE_OPENED); if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) { zilc = (zil_chain_t *)lwb->lwb_buf; bp = &zilc->zc_next_blk; } else { zilc = (zil_chain_t *)(lwb->lwb_buf + lwb->lwb_sz); bp = &zilc->zc_next_blk; } ASSERT(lwb->lwb_nused <= lwb->lwb_sz); /* * Allocate the next block and save its address in this block * before writing it in order to establish the log chain. * Note that if the allocation of nlwb synced before we wrote * the block that points at it (lwb), we'd leak it if we crashed. * Therefore, we don't do dmu_tx_commit() until zil_lwb_write_done(). * We dirty the dataset to ensure that zil_sync() will be called * to clean up in the event of allocation failure or I/O failure. */ tx = dmu_tx_create(zilog->zl_os); /* * Since we are not going to create any new dirty data, and we * can even help with clearing the existing dirty data, we * should not be subject to the dirty data based delays. We * use TXG_NOTHROTTLE to bypass the delay mechanism. */ VERIFY0(dmu_tx_assign(tx, TXG_WAIT | TXG_NOTHROTTLE)); dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); txg = dmu_tx_get_txg(tx); lwb->lwb_tx = tx; /* * Log blocks are pre-allocated. Here we select the size of the next * block, based on size used in the last block. * - first find the smallest bucket that will fit the block from a * limited set of block sizes. This is because it's faster to write * blocks allocated from the same metaslab as they are adjacent or * close. * - next find the maximum from the new suggested size and an array of * previous sizes. This lessens a picket fence effect of wrongly * guessing the size if we have a stream of say 2k, 64k, 2k, 64k * requests. * * Note we only write what is used, but we can't just allocate * the maximum block size because we can exhaust the available * pool log space. */ zil_blksz = zilog->zl_cur_used + sizeof (zil_chain_t); for (i = 0; zil_blksz > zil_block_buckets[i].limit; i++) continue; zil_blksz = MIN(zil_block_buckets[i].blksz, zilog->zl_max_block_size); zilog->zl_prev_blks[zilog->zl_prev_rotor] = zil_blksz; for (i = 0; i < ZIL_PREV_BLKS; i++) zil_blksz = MAX(zil_blksz, zilog->zl_prev_blks[i]); zilog->zl_prev_rotor = (zilog->zl_prev_rotor + 1) & (ZIL_PREV_BLKS - 1); BP_ZERO(bp); error = zio_alloc_zil(spa, zilog->zl_os, txg, bp, zil_blksz, &slog); if (slog) { ZIL_STAT_BUMP(zil_itx_metaslab_slog_count); ZIL_STAT_INCR(zil_itx_metaslab_slog_bytes, lwb->lwb_nused); } else { ZIL_STAT_BUMP(zil_itx_metaslab_normal_count); ZIL_STAT_INCR(zil_itx_metaslab_normal_bytes, lwb->lwb_nused); } if (error == 0) { ASSERT3U(bp->blk_birth, ==, txg); bp->blk_cksum = lwb->lwb_blk.blk_cksum; bp->blk_cksum.zc_word[ZIL_ZC_SEQ]++; /* * Allocate a new log write block (lwb). */ nlwb = zil_alloc_lwb(zilog, bp, slog, txg, TRUE); } if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) { /* For Slim ZIL only write what is used. */ wsz = P2ROUNDUP_TYPED(lwb->lwb_nused, ZIL_MIN_BLKSZ, uint64_t); ASSERT3U(wsz, <=, lwb->lwb_sz); zio_shrink(lwb->lwb_write_zio, wsz); } else { wsz = lwb->lwb_sz; } zilc->zc_pad = 0; zilc->zc_nused = lwb->lwb_nused; zilc->zc_eck.zec_cksum = lwb->lwb_blk.blk_cksum; /* * clear unused data for security */ bzero(lwb->lwb_buf + lwb->lwb_nused, wsz - lwb->lwb_nused); spa_config_enter(zilog->zl_spa, SCL_STATE, lwb, RW_READER); zil_lwb_add_block(lwb, &lwb->lwb_blk); lwb->lwb_issued_timestamp = gethrtime(); lwb->lwb_state = LWB_STATE_ISSUED; zio_nowait(lwb->lwb_root_zio); zio_nowait(lwb->lwb_write_zio); /* * If there was an allocation failure then nlwb will be null which * forces a txg_wait_synced(). */ return (nlwb); } /* * Maximum amount of write data that can be put into single log block. */ uint64_t zil_max_log_data(zilog_t *zilog) { return (zilog->zl_max_block_size - sizeof (zil_chain_t) - sizeof (lr_write_t)); } /* * Maximum amount of log space we agree to waste to reduce number of * WR_NEED_COPY chunks to reduce zl_get_data() overhead (~12%). */ static inline uint64_t zil_max_waste_space(zilog_t *zilog) { return (zil_max_log_data(zilog) / 8); } /* * Maximum amount of write data for WR_COPIED. For correctness, consumers * must fall back to WR_NEED_COPY if we can't fit the entire record into one * maximum sized log block, because each WR_COPIED record must fit in a * single log block. For space efficiency, we want to fit two records into a * max-sized log block. */ uint64_t zil_max_copied_data(zilog_t *zilog) { return ((zilog->zl_max_block_size - sizeof (zil_chain_t)) / 2 - sizeof (lr_write_t)); } static lwb_t * zil_lwb_commit(zilog_t *zilog, itx_t *itx, lwb_t *lwb) { lr_t *lrcb, *lrc; lr_write_t *lrwb, *lrw; char *lr_buf; uint64_t dlen, dnow, lwb_sp, reclen, txg, max_log_data; ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); ASSERT3P(lwb, !=, NULL); ASSERT3P(lwb->lwb_buf, !=, NULL); zil_lwb_write_open(zilog, lwb); lrc = &itx->itx_lr; lrw = (lr_write_t *)lrc; /* * A commit itx doesn't represent any on-disk state; instead * it's simply used as a place holder on the commit list, and * provides a mechanism for attaching a "commit waiter" onto the * correct lwb (such that the waiter can be signalled upon * completion of that lwb). Thus, we don't process this itx's * log record if it's a commit itx (these itx's don't have log * records), and instead link the itx's waiter onto the lwb's * list of waiters. * * For more details, see the comment above zil_commit(). */ if (lrc->lrc_txtype == TX_COMMIT) { mutex_enter(&zilog->zl_lock); zil_commit_waiter_link_lwb(itx->itx_private, lwb); itx->itx_private = NULL; mutex_exit(&zilog->zl_lock); return (lwb); } if (lrc->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY) { dlen = P2ROUNDUP_TYPED( lrw->lr_length, sizeof (uint64_t), uint64_t); } else { dlen = 0; } reclen = lrc->lrc_reclen; zilog->zl_cur_used += (reclen + dlen); txg = lrc->lrc_txg; ASSERT3U(zilog->zl_cur_used, <, UINT64_MAX - (reclen + dlen)); cont: /* * If this record won't fit in the current log block, start a new one. * For WR_NEED_COPY optimize layout for minimal number of chunks. */ lwb_sp = lwb->lwb_sz - lwb->lwb_nused; max_log_data = zil_max_log_data(zilog); if (reclen > lwb_sp || (reclen + dlen > lwb_sp && lwb_sp < zil_max_waste_space(zilog) && (dlen % max_log_data == 0 || lwb_sp < reclen + dlen % max_log_data))) { lwb = zil_lwb_write_issue(zilog, lwb); if (lwb == NULL) return (NULL); zil_lwb_write_open(zilog, lwb); ASSERT(LWB_EMPTY(lwb)); lwb_sp = lwb->lwb_sz - lwb->lwb_nused; /* * There must be enough space in the new, empty log block to * hold reclen. For WR_COPIED, we need to fit the whole * record in one block, and reclen is the header size + the * data size. For WR_NEED_COPY, we can create multiple * records, splitting the data into multiple blocks, so we * only need to fit one word of data per block; in this case * reclen is just the header size (no data). */ ASSERT3U(reclen + MIN(dlen, sizeof (uint64_t)), <=, lwb_sp); } dnow = MIN(dlen, lwb_sp - reclen); lr_buf = lwb->lwb_buf + lwb->lwb_nused; bcopy(lrc, lr_buf, reclen); lrcb = (lr_t *)lr_buf; /* Like lrc, but inside lwb. */ lrwb = (lr_write_t *)lrcb; /* Like lrw, but inside lwb. */ ZIL_STAT_BUMP(zil_itx_count); /* * If it's a write, fetch the data or get its blkptr as appropriate. */ if (lrc->lrc_txtype == TX_WRITE) { if (txg > spa_freeze_txg(zilog->zl_spa)) txg_wait_synced(zilog->zl_dmu_pool, txg); if (itx->itx_wr_state == WR_COPIED) { ZIL_STAT_BUMP(zil_itx_copied_count); ZIL_STAT_INCR(zil_itx_copied_bytes, lrw->lr_length); } else { char *dbuf; int error; if (itx->itx_wr_state == WR_NEED_COPY) { dbuf = lr_buf + reclen; lrcb->lrc_reclen += dnow; if (lrwb->lr_length > dnow) lrwb->lr_length = dnow; lrw->lr_offset += dnow; lrw->lr_length -= dnow; ZIL_STAT_BUMP(zil_itx_needcopy_count); ZIL_STAT_INCR(zil_itx_needcopy_bytes, dnow); } else { ASSERT3S(itx->itx_wr_state, ==, WR_INDIRECT); dbuf = NULL; ZIL_STAT_BUMP(zil_itx_indirect_count); ZIL_STAT_INCR(zil_itx_indirect_bytes, lrw->lr_length); } /* * We pass in the "lwb_write_zio" rather than * "lwb_root_zio" so that the "lwb_write_zio" * becomes the parent of any zio's created by * the "zl_get_data" callback. The vdevs are * flushed after the "lwb_write_zio" completes, * so we want to make sure that completion * callback waits for these additional zio's, * such that the vdevs used by those zio's will * be included in the lwb's vdev tree, and those * vdevs will be properly flushed. If we passed * in "lwb_root_zio" here, then these additional * vdevs may not be flushed; e.g. if these zio's * completed after "lwb_write_zio" completed. */ error = zilog->zl_get_data(itx->itx_private, lrwb, dbuf, lwb, lwb->lwb_write_zio); if (error == EIO) { txg_wait_synced(zilog->zl_dmu_pool, txg); return (lwb); } if (error != 0) { ASSERT(error == ENOENT || error == EEXIST || error == EALREADY); return (lwb); } } } /* * We're actually making an entry, so update lrc_seq to be the * log record sequence number. Note that this is generally not * equal to the itx sequence number because not all transactions * are synchronous, and sometimes spa_sync() gets there first. */ lrcb->lrc_seq = ++zilog->zl_lr_seq; lwb->lwb_nused += reclen + dnow; zil_lwb_add_txg(lwb, txg); ASSERT3U(lwb->lwb_nused, <=, lwb->lwb_sz); ASSERT0(P2PHASE(lwb->lwb_nused, sizeof (uint64_t))); dlen -= dnow; if (dlen > 0) { zilog->zl_cur_used += reclen; goto cont; } return (lwb); } itx_t * zil_itx_create(uint64_t txtype, size_t lrsize) { size_t itxsize; itx_t *itx; lrsize = P2ROUNDUP_TYPED(lrsize, sizeof (uint64_t), size_t); itxsize = offsetof(itx_t, itx_lr) + lrsize; itx = zio_data_buf_alloc(itxsize); itx->itx_lr.lrc_txtype = txtype; itx->itx_lr.lrc_reclen = lrsize; itx->itx_lr.lrc_seq = 0; /* defensive */ itx->itx_sync = B_TRUE; /* default is synchronous */ itx->itx_callback = NULL; itx->itx_callback_data = NULL; itx->itx_size = itxsize; return (itx); } void zil_itx_destroy(itx_t *itx) { IMPLY(itx->itx_lr.lrc_txtype == TX_COMMIT, itx->itx_callback == NULL); IMPLY(itx->itx_callback != NULL, itx->itx_lr.lrc_txtype != TX_COMMIT); if (itx->itx_callback != NULL) itx->itx_callback(itx->itx_callback_data); zio_data_buf_free(itx, itx->itx_size); } /* * Free up the sync and async itxs. The itxs_t has already been detached * so no locks are needed. */ static void zil_itxg_clean(itxs_t *itxs) { itx_t *itx; list_t *list; avl_tree_t *t; void *cookie; itx_async_node_t *ian; list = &itxs->i_sync_list; while ((itx = list_head(list)) != NULL) { /* * In the general case, commit itxs will not be found * here, as they'll be committed to an lwb via * zil_lwb_commit(), and free'd in that function. Having * said that, it is still possible for commit itxs to be * found here, due to the following race: * * - a thread calls zil_commit() which assigns the * commit itx to a per-txg i_sync_list * - zil_itxg_clean() is called (e.g. via spa_sync()) * while the waiter is still on the i_sync_list * * There's nothing to prevent syncing the txg while the * waiter is on the i_sync_list. This normally doesn't * happen because spa_sync() is slower than zil_commit(), * but if zil_commit() calls txg_wait_synced() (e.g. * because zil_create() or zil_commit_writer_stall() is * called) we will hit this case. */ if (itx->itx_lr.lrc_txtype == TX_COMMIT) zil_commit_waiter_skip(itx->itx_private); list_remove(list, itx); zil_itx_destroy(itx); } cookie = NULL; t = &itxs->i_async_tree; while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) { list = &ian->ia_list; while ((itx = list_head(list)) != NULL) { list_remove(list, itx); /* commit itxs should never be on the async lists. */ ASSERT3U(itx->itx_lr.lrc_txtype, !=, TX_COMMIT); zil_itx_destroy(itx); } list_destroy(list); kmem_free(ian, sizeof (itx_async_node_t)); } avl_destroy(t); kmem_free(itxs, sizeof (itxs_t)); } static int zil_aitx_compare(const void *x1, const void *x2) { const uint64_t o1 = ((itx_async_node_t *)x1)->ia_foid; const uint64_t o2 = ((itx_async_node_t *)x2)->ia_foid; return (TREE_CMP(o1, o2)); } /* * Remove all async itx with the given oid. */ void zil_remove_async(zilog_t *zilog, uint64_t oid) { uint64_t otxg, txg; itx_async_node_t *ian; avl_tree_t *t; avl_index_t where; list_t clean_list; itx_t *itx; ASSERT(oid != 0); list_create(&clean_list, sizeof (itx_t), offsetof(itx_t, itx_node)); if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ otxg = ZILTEST_TXG; else otxg = spa_last_synced_txg(zilog->zl_spa) + 1; for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; mutex_enter(&itxg->itxg_lock); if (itxg->itxg_txg != txg) { mutex_exit(&itxg->itxg_lock); continue; } /* * Locate the object node and append its list. */ t = &itxg->itxg_itxs->i_async_tree; ian = avl_find(t, &oid, &where); if (ian != NULL) list_move_tail(&clean_list, &ian->ia_list); mutex_exit(&itxg->itxg_lock); } while ((itx = list_head(&clean_list)) != NULL) { list_remove(&clean_list, itx); /* commit itxs should never be on the async lists. */ ASSERT3U(itx->itx_lr.lrc_txtype, !=, TX_COMMIT); zil_itx_destroy(itx); } list_destroy(&clean_list); } void zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx) { uint64_t txg; itxg_t *itxg; itxs_t *itxs, *clean = NULL; /* * Ensure the data of a renamed file is committed before the rename. */ if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_RENAME) zil_async_to_sync(zilog, itx->itx_oid); if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) txg = ZILTEST_TXG; else txg = dmu_tx_get_txg(tx); itxg = &zilog->zl_itxg[txg & TXG_MASK]; mutex_enter(&itxg->itxg_lock); itxs = itxg->itxg_itxs; if (itxg->itxg_txg != txg) { if (itxs != NULL) { /* * The zil_clean callback hasn't got around to cleaning * this itxg. Save the itxs for release below. * This should be rare. */ zfs_dbgmsg("zil_itx_assign: missed itx cleanup for " "txg %llu", itxg->itxg_txg); clean = itxg->itxg_itxs; } itxg->itxg_txg = txg; itxs = itxg->itxg_itxs = kmem_zalloc(sizeof (itxs_t), KM_SLEEP); list_create(&itxs->i_sync_list, sizeof (itx_t), offsetof(itx_t, itx_node)); avl_create(&itxs->i_async_tree, zil_aitx_compare, sizeof (itx_async_node_t), offsetof(itx_async_node_t, ia_node)); } if (itx->itx_sync) { list_insert_tail(&itxs->i_sync_list, itx); } else { avl_tree_t *t = &itxs->i_async_tree; uint64_t foid = LR_FOID_GET_OBJ(((lr_ooo_t *)&itx->itx_lr)->lr_foid); itx_async_node_t *ian; avl_index_t where; ian = avl_find(t, &foid, &where); if (ian == NULL) { ian = kmem_alloc(sizeof (itx_async_node_t), KM_SLEEP); list_create(&ian->ia_list, sizeof (itx_t), offsetof(itx_t, itx_node)); ian->ia_foid = foid; avl_insert(t, ian, where); } list_insert_tail(&ian->ia_list, itx); } itx->itx_lr.lrc_txg = dmu_tx_get_txg(tx); /* * We don't want to dirty the ZIL using ZILTEST_TXG, because * zil_clean() will never be called using ZILTEST_TXG. Thus, we * need to be careful to always dirty the ZIL using the "real" * TXG (not itxg_txg) even when the SPA is frozen. */ zilog_dirty(zilog, dmu_tx_get_txg(tx)); mutex_exit(&itxg->itxg_lock); /* Release the old itxs now we've dropped the lock */ if (clean != NULL) zil_itxg_clean(clean); } /* * If there are any in-memory intent log transactions which have now been * synced then start up a taskq to free them. We should only do this after we * have written out the uberblocks (i.e. txg has been committed) so that * don't inadvertently clean out in-memory log records that would be required * by zil_commit(). */ void zil_clean(zilog_t *zilog, uint64_t synced_txg) { itxg_t *itxg = &zilog->zl_itxg[synced_txg & TXG_MASK]; itxs_t *clean_me; ASSERT3U(synced_txg, <, ZILTEST_TXG); mutex_enter(&itxg->itxg_lock); if (itxg->itxg_itxs == NULL || itxg->itxg_txg == ZILTEST_TXG) { mutex_exit(&itxg->itxg_lock); return; } ASSERT3U(itxg->itxg_txg, <=, synced_txg); ASSERT3U(itxg->itxg_txg, !=, 0); clean_me = itxg->itxg_itxs; itxg->itxg_itxs = NULL; itxg->itxg_txg = 0; mutex_exit(&itxg->itxg_lock); /* * Preferably start a task queue to free up the old itxs but * if taskq_dispatch can't allocate resources to do that then * free it in-line. This should be rare. Note, using TQ_SLEEP * created a bad performance problem. */ ASSERT3P(zilog->zl_dmu_pool, !=, NULL); ASSERT3P(zilog->zl_dmu_pool->dp_zil_clean_taskq, !=, NULL); taskqid_t id = taskq_dispatch(zilog->zl_dmu_pool->dp_zil_clean_taskq, (void (*)(void *))zil_itxg_clean, clean_me, TQ_NOSLEEP); if (id == TASKQID_INVALID) zil_itxg_clean(clean_me); } /* * This function will traverse the queue of itxs that need to be * committed, and move them onto the ZIL's zl_itx_commit_list. */ static void zil_get_commit_list(zilog_t *zilog) { uint64_t otxg, txg; list_t *commit_list = &zilog->zl_itx_commit_list; ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ otxg = ZILTEST_TXG; else otxg = spa_last_synced_txg(zilog->zl_spa) + 1; /* * This is inherently racy, since there is nothing to prevent * the last synced txg from changing. That's okay since we'll * only commit things in the future. */ for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; mutex_enter(&itxg->itxg_lock); if (itxg->itxg_txg != txg) { mutex_exit(&itxg->itxg_lock); continue; } /* * If we're adding itx records to the zl_itx_commit_list, * then the zil better be dirty in this "txg". We can assert * that here since we're holding the itxg_lock which will * prevent spa_sync from cleaning it. Once we add the itxs * to the zl_itx_commit_list we must commit it to disk even * if it's unnecessary (i.e. the txg was synced). */ ASSERT(zilog_is_dirty_in_txg(zilog, txg) || spa_freeze_txg(zilog->zl_spa) != UINT64_MAX); list_move_tail(commit_list, &itxg->itxg_itxs->i_sync_list); mutex_exit(&itxg->itxg_lock); } } /* * Move the async itxs for a specified object to commit into sync lists. */ void zil_async_to_sync(zilog_t *zilog, uint64_t foid) { uint64_t otxg, txg; itx_async_node_t *ian; avl_tree_t *t; avl_index_t where; if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ otxg = ZILTEST_TXG; else otxg = spa_last_synced_txg(zilog->zl_spa) + 1; /* * This is inherently racy, since there is nothing to prevent * the last synced txg from changing. */ for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; mutex_enter(&itxg->itxg_lock); if (itxg->itxg_txg != txg) { mutex_exit(&itxg->itxg_lock); continue; } /* * If a foid is specified then find that node and append its * list. Otherwise walk the tree appending all the lists * to the sync list. We add to the end rather than the * beginning to ensure the create has happened. */ t = &itxg->itxg_itxs->i_async_tree; if (foid != 0) { ian = avl_find(t, &foid, &where); if (ian != NULL) { list_move_tail(&itxg->itxg_itxs->i_sync_list, &ian->ia_list); } } else { void *cookie = NULL; while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) { list_move_tail(&itxg->itxg_itxs->i_sync_list, &ian->ia_list); list_destroy(&ian->ia_list); kmem_free(ian, sizeof (itx_async_node_t)); } } mutex_exit(&itxg->itxg_lock); } } /* * This function will prune commit itxs that are at the head of the * commit list (it won't prune past the first non-commit itx), and * either: a) attach them to the last lwb that's still pending * completion, or b) skip them altogether. * * This is used as a performance optimization to prevent commit itxs * from generating new lwbs when it's unnecessary to do so. */ static void zil_prune_commit_list(zilog_t *zilog) { itx_t *itx; ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); while ((itx = list_head(&zilog->zl_itx_commit_list)) != NULL) { lr_t *lrc = &itx->itx_lr; if (lrc->lrc_txtype != TX_COMMIT) break; mutex_enter(&zilog->zl_lock); lwb_t *last_lwb = zilog->zl_last_lwb_opened; if (last_lwb == NULL || last_lwb->lwb_state == LWB_STATE_FLUSH_DONE) { /* * All of the itxs this waiter was waiting on * must have already completed (or there were * never any itx's for it to wait on), so it's * safe to skip this waiter and mark it done. */ zil_commit_waiter_skip(itx->itx_private); } else { zil_commit_waiter_link_lwb(itx->itx_private, last_lwb); itx->itx_private = NULL; } mutex_exit(&zilog->zl_lock); list_remove(&zilog->zl_itx_commit_list, itx); zil_itx_destroy(itx); } IMPLY(itx != NULL, itx->itx_lr.lrc_txtype != TX_COMMIT); } static void zil_commit_writer_stall(zilog_t *zilog) { /* * When zio_alloc_zil() fails to allocate the next lwb block on * disk, we must call txg_wait_synced() to ensure all of the * lwbs in the zilog's zl_lwb_list are synced and then freed (in * zil_sync()), such that any subsequent ZIL writer (i.e. a call * to zil_process_commit_list()) will have to call zil_create(), * and start a new ZIL chain. * * Since zil_alloc_zil() failed, the lwb that was previously * issued does not have a pointer to the "next" lwb on disk. * Thus, if another ZIL writer thread was to allocate the "next" * on-disk lwb, that block could be leaked in the event of a * crash (because the previous lwb on-disk would not point to * it). * * We must hold the zilog's zl_issuer_lock while we do this, to * ensure no new threads enter zil_process_commit_list() until * all lwb's in the zl_lwb_list have been synced and freed * (which is achieved via the txg_wait_synced() call). */ ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); txg_wait_synced(zilog->zl_dmu_pool, 0); ASSERT3P(list_tail(&zilog->zl_lwb_list), ==, NULL); } /* * This function will traverse the commit list, creating new lwbs as * needed, and committing the itxs from the commit list to these newly * created lwbs. Additionally, as a new lwb is created, the previous * lwb will be issued to the zio layer to be written to disk. */ static void zil_process_commit_list(zilog_t *zilog) { spa_t *spa = zilog->zl_spa; list_t nolwb_itxs; list_t nolwb_waiters; lwb_t *lwb; itx_t *itx; ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); /* * Return if there's nothing to commit before we dirty the fs by * calling zil_create(). */ if (list_head(&zilog->zl_itx_commit_list) == NULL) return; list_create(&nolwb_itxs, sizeof (itx_t), offsetof(itx_t, itx_node)); list_create(&nolwb_waiters, sizeof (zil_commit_waiter_t), offsetof(zil_commit_waiter_t, zcw_node)); lwb = list_tail(&zilog->zl_lwb_list); if (lwb == NULL) { lwb = zil_create(zilog); } else { ASSERT3S(lwb->lwb_state, !=, LWB_STATE_ISSUED); ASSERT3S(lwb->lwb_state, !=, LWB_STATE_WRITE_DONE); ASSERT3S(lwb->lwb_state, !=, LWB_STATE_FLUSH_DONE); } while ((itx = list_head(&zilog->zl_itx_commit_list)) != NULL) { lr_t *lrc = &itx->itx_lr; uint64_t txg = lrc->lrc_txg; ASSERT3U(txg, !=, 0); if (lrc->lrc_txtype == TX_COMMIT) { DTRACE_PROBE2(zil__process__commit__itx, zilog_t *, zilog, itx_t *, itx); } else { DTRACE_PROBE2(zil__process__normal__itx, zilog_t *, zilog, itx_t *, itx); } list_remove(&zilog->zl_itx_commit_list, itx); boolean_t synced = txg <= spa_last_synced_txg(spa); boolean_t frozen = txg > spa_freeze_txg(spa); /* * If the txg of this itx has already been synced out, then * we don't need to commit this itx to an lwb. This is * because the data of this itx will have already been * written to the main pool. This is inherently racy, and * it's still ok to commit an itx whose txg has already * been synced; this will result in a write that's * unnecessary, but will do no harm. * * With that said, we always want to commit TX_COMMIT itxs * to an lwb, regardless of whether or not that itx's txg * has been synced out. We do this to ensure any OPENED lwb * will always have at least one zil_commit_waiter_t linked * to the lwb. * * As a counter-example, if we skipped TX_COMMIT itx's * whose txg had already been synced, the following * situation could occur if we happened to be racing with * spa_sync: * * 1. We commit a non-TX_COMMIT itx to an lwb, where the * itx's txg is 10 and the last synced txg is 9. * 2. spa_sync finishes syncing out txg 10. * 3. We move to the next itx in the list, it's a TX_COMMIT * whose txg is 10, so we skip it rather than committing * it to the lwb used in (1). * * If the itx that is skipped in (3) is the last TX_COMMIT * itx in the commit list, than it's possible for the lwb * used in (1) to remain in the OPENED state indefinitely. * * To prevent the above scenario from occurring, ensuring * that once an lwb is OPENED it will transition to ISSUED * and eventually DONE, we always commit TX_COMMIT itx's to * an lwb here, even if that itx's txg has already been * synced. * * Finally, if the pool is frozen, we _always_ commit the * itx. The point of freezing the pool is to prevent data * from being written to the main pool via spa_sync, and * instead rely solely on the ZIL to persistently store the * data; i.e. when the pool is frozen, the last synced txg * value can't be trusted. */ if (frozen || !synced || lrc->lrc_txtype == TX_COMMIT) { if (lwb != NULL) { lwb = zil_lwb_commit(zilog, itx, lwb); if (lwb == NULL) list_insert_tail(&nolwb_itxs, itx); else list_insert_tail(&lwb->lwb_itxs, itx); } else { if (lrc->lrc_txtype == TX_COMMIT) { zil_commit_waiter_link_nolwb( itx->itx_private, &nolwb_waiters); } list_insert_tail(&nolwb_itxs, itx); } } else { ASSERT3S(lrc->lrc_txtype, !=, TX_COMMIT); zil_itx_destroy(itx); } } if (lwb == NULL) { /* * This indicates zio_alloc_zil() failed to allocate the * "next" lwb on-disk. When this happens, we must stall * the ZIL write pipeline; see the comment within * zil_commit_writer_stall() for more details. */ zil_commit_writer_stall(zilog); /* * Additionally, we have to signal and mark the "nolwb" * waiters as "done" here, since without an lwb, we * can't do this via zil_lwb_flush_vdevs_done() like * normal. */ zil_commit_waiter_t *zcw; while ((zcw = list_head(&nolwb_waiters)) != NULL) { zil_commit_waiter_skip(zcw); list_remove(&nolwb_waiters, zcw); } /* * And finally, we have to destroy the itx's that * couldn't be committed to an lwb; this will also call * the itx's callback if one exists for the itx. */ while ((itx = list_head(&nolwb_itxs)) != NULL) { list_remove(&nolwb_itxs, itx); zil_itx_destroy(itx); } } else { ASSERT(list_is_empty(&nolwb_waiters)); ASSERT3P(lwb, !=, NULL); ASSERT3S(lwb->lwb_state, !=, LWB_STATE_ISSUED); ASSERT3S(lwb->lwb_state, !=, LWB_STATE_WRITE_DONE); ASSERT3S(lwb->lwb_state, !=, LWB_STATE_FLUSH_DONE); /* * At this point, the ZIL block pointed at by the "lwb" * variable is in one of the following states: "closed" * or "open". * * If it's "closed", then no itxs have been committed to * it, so there's no point in issuing its zio (i.e. it's * "empty"). * * If it's "open", then it contains one or more itxs that * eventually need to be committed to stable storage. In * this case we intentionally do not issue the lwb's zio * to disk yet, and instead rely on one of the following * two mechanisms for issuing the zio: * * 1. Ideally, there will be more ZIL activity occurring * on the system, such that this function will be * immediately called again (not necessarily by the same * thread) and this lwb's zio will be issued via * zil_lwb_commit(). This way, the lwb is guaranteed to * be "full" when it is issued to disk, and we'll make * use of the lwb's size the best we can. * * 2. If there isn't sufficient ZIL activity occurring on * the system, such that this lwb's zio isn't issued via * zil_lwb_commit(), zil_commit_waiter() will issue the * lwb's zio. If this occurs, the lwb is not guaranteed * to be "full" by the time its zio is issued, and means * the size of the lwb was "too large" given the amount * of ZIL activity occurring on the system at that time. * * We do this for a couple of reasons: * * 1. To try and reduce the number of IOPs needed to * write the same number of itxs. If an lwb has space * available in its buffer for more itxs, and more itxs * will be committed relatively soon (relative to the * latency of performing a write), then it's beneficial * to wait for these "next" itxs. This way, more itxs * can be committed to stable storage with fewer writes. * * 2. To try and use the largest lwb block size that the * incoming rate of itxs can support. Again, this is to * try and pack as many itxs into as few lwbs as * possible, without significantly impacting the latency * of each individual itx. */ } } /* * This function is responsible for ensuring the passed in commit waiter * (and associated commit itx) is committed to an lwb. If the waiter is * not already committed to an lwb, all itxs in the zilog's queue of * itxs will be processed. The assumption is the passed in waiter's * commit itx will found in the queue just like the other non-commit * itxs, such that when the entire queue is processed, the waiter will * have been committed to an lwb. * * The lwb associated with the passed in waiter is not guaranteed to * have been issued by the time this function completes. If the lwb is * not issued, we rely on future calls to zil_commit_writer() to issue * the lwb, or the timeout mechanism found in zil_commit_waiter(). */ static void zil_commit_writer(zilog_t *zilog, zil_commit_waiter_t *zcw) { ASSERT(!MUTEX_HELD(&zilog->zl_lock)); ASSERT(spa_writeable(zilog->zl_spa)); mutex_enter(&zilog->zl_issuer_lock); if (zcw->zcw_lwb != NULL || zcw->zcw_done) { /* * It's possible that, while we were waiting to acquire * the "zl_issuer_lock", another thread committed this * waiter to an lwb. If that occurs, we bail out early, * without processing any of the zilog's queue of itxs. * * On certain workloads and system configurations, the * "zl_issuer_lock" can become highly contended. In an * attempt to reduce this contention, we immediately drop * the lock if the waiter has already been processed. * * We've measured this optimization to reduce CPU spent * contending on this lock by up to 5%, using a system * with 32 CPUs, low latency storage (~50 usec writes), * and 1024 threads performing sync writes. */ goto out; } ZIL_STAT_BUMP(zil_commit_writer_count); zil_get_commit_list(zilog); zil_prune_commit_list(zilog); zil_process_commit_list(zilog); out: mutex_exit(&zilog->zl_issuer_lock); } static void zil_commit_waiter_timeout(zilog_t *zilog, zil_commit_waiter_t *zcw) { ASSERT(!MUTEX_HELD(&zilog->zl_issuer_lock)); ASSERT(MUTEX_HELD(&zcw->zcw_lock)); ASSERT3B(zcw->zcw_done, ==, B_FALSE); lwb_t *lwb = zcw->zcw_lwb; ASSERT3P(lwb, !=, NULL); ASSERT3S(lwb->lwb_state, !=, LWB_STATE_CLOSED); /* * If the lwb has already been issued by another thread, we can * immediately return since there's no work to be done (the * point of this function is to issue the lwb). Additionally, we * do this prior to acquiring the zl_issuer_lock, to avoid * acquiring it when it's not necessary to do so. */ if (lwb->lwb_state == LWB_STATE_ISSUED || lwb->lwb_state == LWB_STATE_WRITE_DONE || lwb->lwb_state == LWB_STATE_FLUSH_DONE) return; /* * In order to call zil_lwb_write_issue() we must hold the * zilog's "zl_issuer_lock". We can't simply acquire that lock, * since we're already holding the commit waiter's "zcw_lock", * and those two locks are acquired in the opposite order * elsewhere. */ mutex_exit(&zcw->zcw_lock); mutex_enter(&zilog->zl_issuer_lock); mutex_enter(&zcw->zcw_lock); /* * Since we just dropped and re-acquired the commit waiter's * lock, we have to re-check to see if the waiter was marked * "done" during that process. If the waiter was marked "done", * the "lwb" pointer is no longer valid (it can be free'd after * the waiter is marked "done"), so without this check we could * wind up with a use-after-free error below. */ if (zcw->zcw_done) goto out; ASSERT3P(lwb, ==, zcw->zcw_lwb); /* * We've already checked this above, but since we hadn't acquired * the zilog's zl_issuer_lock, we have to perform this check a * second time while holding the lock. * * We don't need to hold the zl_lock since the lwb cannot transition * from OPENED to ISSUED while we hold the zl_issuer_lock. The lwb * _can_ transition from ISSUED to DONE, but it's OK to race with * that transition since we treat the lwb the same, whether it's in * the ISSUED or DONE states. * * The important thing, is we treat the lwb differently depending on * if it's ISSUED or OPENED, and block any other threads that might * attempt to issue this lwb. For that reason we hold the * zl_issuer_lock when checking the lwb_state; we must not call * zil_lwb_write_issue() if the lwb had already been issued. * * See the comment above the lwb_state_t structure definition for * more details on the lwb states, and locking requirements. */ if (lwb->lwb_state == LWB_STATE_ISSUED || lwb->lwb_state == LWB_STATE_WRITE_DONE || lwb->lwb_state == LWB_STATE_FLUSH_DONE) goto out; ASSERT3S(lwb->lwb_state, ==, LWB_STATE_OPENED); /* * As described in the comments above zil_commit_waiter() and * zil_process_commit_list(), we need to issue this lwb's zio * since we've reached the commit waiter's timeout and it still * hasn't been issued. */ lwb_t *nlwb = zil_lwb_write_issue(zilog, lwb); IMPLY(nlwb != NULL, lwb->lwb_state != LWB_STATE_OPENED); /* * Since the lwb's zio hadn't been issued by the time this thread * reached its timeout, we reset the zilog's "zl_cur_used" field * to influence the zil block size selection algorithm. * * By having to issue the lwb's zio here, it means the size of the * lwb was too large, given the incoming throughput of itxs. By * setting "zl_cur_used" to zero, we communicate this fact to the * block size selection algorithm, so it can take this information * into account, and potentially select a smaller size for the * next lwb block that is allocated. */ zilog->zl_cur_used = 0; if (nlwb == NULL) { /* * When zil_lwb_write_issue() returns NULL, this * indicates zio_alloc_zil() failed to allocate the * "next" lwb on-disk. When this occurs, the ZIL write * pipeline must be stalled; see the comment within the * zil_commit_writer_stall() function for more details. * * We must drop the commit waiter's lock prior to * calling zil_commit_writer_stall() or else we can wind * up with the following deadlock: * * - This thread is waiting for the txg to sync while * holding the waiter's lock; txg_wait_synced() is * used within txg_commit_writer_stall(). * * - The txg can't sync because it is waiting for this * lwb's zio callback to call dmu_tx_commit(). * * - The lwb's zio callback can't call dmu_tx_commit() * because it's blocked trying to acquire the waiter's * lock, which occurs prior to calling dmu_tx_commit() */ mutex_exit(&zcw->zcw_lock); zil_commit_writer_stall(zilog); mutex_enter(&zcw->zcw_lock); } out: mutex_exit(&zilog->zl_issuer_lock); ASSERT(MUTEX_HELD(&zcw->zcw_lock)); } /* * This function is responsible for performing the following two tasks: * * 1. its primary responsibility is to block until the given "commit * waiter" is considered "done". * * 2. its secondary responsibility is to issue the zio for the lwb that * the given "commit waiter" is waiting on, if this function has * waited "long enough" and the lwb is still in the "open" state. * * Given a sufficient amount of itxs being generated and written using * the ZIL, the lwb's zio will be issued via the zil_lwb_commit() * function. If this does not occur, this secondary responsibility will * ensure the lwb is issued even if there is not other synchronous * activity on the system. * * For more details, see zil_process_commit_list(); more specifically, * the comment at the bottom of that function. */ static void zil_commit_waiter(zilog_t *zilog, zil_commit_waiter_t *zcw) { ASSERT(!MUTEX_HELD(&zilog->zl_lock)); ASSERT(!MUTEX_HELD(&zilog->zl_issuer_lock)); ASSERT(spa_writeable(zilog->zl_spa)); mutex_enter(&zcw->zcw_lock); /* * The timeout is scaled based on the lwb latency to avoid * significantly impacting the latency of each individual itx. * For more details, see the comment at the bottom of the * zil_process_commit_list() function. */ int pct = MAX(zfs_commit_timeout_pct, 1); hrtime_t sleep = (zilog->zl_last_lwb_latency * pct) / 100; hrtime_t wakeup = gethrtime() + sleep; boolean_t timedout = B_FALSE; while (!zcw->zcw_done) { ASSERT(MUTEX_HELD(&zcw->zcw_lock)); lwb_t *lwb = zcw->zcw_lwb; /* * Usually, the waiter will have a non-NULL lwb field here, * but it's possible for it to be NULL as a result of * zil_commit() racing with spa_sync(). * * When zil_clean() is called, it's possible for the itxg * list (which may be cleaned via a taskq) to contain * commit itxs. When this occurs, the commit waiters linked * off of these commit itxs will not be committed to an * lwb. Additionally, these commit waiters will not be * marked done until zil_commit_waiter_skip() is called via * zil_itxg_clean(). * * Thus, it's possible for this commit waiter (i.e. the * "zcw" variable) to be found in this "in between" state; * where it's "zcw_lwb" field is NULL, and it hasn't yet * been skipped, so it's "zcw_done" field is still B_FALSE. */ IMPLY(lwb != NULL, lwb->lwb_state != LWB_STATE_CLOSED); if (lwb != NULL && lwb->lwb_state == LWB_STATE_OPENED) { ASSERT3B(timedout, ==, B_FALSE); /* * If the lwb hasn't been issued yet, then we * need to wait with a timeout, in case this * function needs to issue the lwb after the * timeout is reached; responsibility (2) from * the comment above this function. */ int rc = cv_timedwait_hires(&zcw->zcw_cv, &zcw->zcw_lock, wakeup, USEC2NSEC(1), CALLOUT_FLAG_ABSOLUTE); if (rc != -1 || zcw->zcw_done) continue; timedout = B_TRUE; zil_commit_waiter_timeout(zilog, zcw); if (!zcw->zcw_done) { /* * If the commit waiter has already been * marked "done", it's possible for the * waiter's lwb structure to have already * been freed. Thus, we can only reliably * make these assertions if the waiter * isn't done. */ ASSERT3P(lwb, ==, zcw->zcw_lwb); ASSERT3S(lwb->lwb_state, !=, LWB_STATE_OPENED); } } else { /* * If the lwb isn't open, then it must have already * been issued. In that case, there's no need to * use a timeout when waiting for the lwb to * complete. * * Additionally, if the lwb is NULL, the waiter * will soon be signaled and marked done via * zil_clean() and zil_itxg_clean(), so no timeout * is required. */ IMPLY(lwb != NULL, lwb->lwb_state == LWB_STATE_ISSUED || lwb->lwb_state == LWB_STATE_WRITE_DONE || lwb->lwb_state == LWB_STATE_FLUSH_DONE); cv_wait(&zcw->zcw_cv, &zcw->zcw_lock); } } mutex_exit(&zcw->zcw_lock); } static zil_commit_waiter_t * zil_alloc_commit_waiter(void) { zil_commit_waiter_t *zcw = kmem_cache_alloc(zil_zcw_cache, KM_SLEEP); cv_init(&zcw->zcw_cv, NULL, CV_DEFAULT, NULL); mutex_init(&zcw->zcw_lock, NULL, MUTEX_DEFAULT, NULL); list_link_init(&zcw->zcw_node); zcw->zcw_lwb = NULL; zcw->zcw_done = B_FALSE; zcw->zcw_zio_error = 0; return (zcw); } static void zil_free_commit_waiter(zil_commit_waiter_t *zcw) { ASSERT(!list_link_active(&zcw->zcw_node)); ASSERT3P(zcw->zcw_lwb, ==, NULL); ASSERT3B(zcw->zcw_done, ==, B_TRUE); mutex_destroy(&zcw->zcw_lock); cv_destroy(&zcw->zcw_cv); kmem_cache_free(zil_zcw_cache, zcw); } /* * This function is used to create a TX_COMMIT itx and assign it. This * way, it will be linked into the ZIL's list of synchronous itxs, and * then later committed to an lwb (or skipped) when * zil_process_commit_list() is called. */ static void zil_commit_itx_assign(zilog_t *zilog, zil_commit_waiter_t *zcw) { dmu_tx_t *tx = dmu_tx_create(zilog->zl_os); VERIFY0(dmu_tx_assign(tx, TXG_WAIT)); itx_t *itx = zil_itx_create(TX_COMMIT, sizeof (lr_t)); itx->itx_sync = B_TRUE; itx->itx_private = zcw; zil_itx_assign(zilog, itx, tx); dmu_tx_commit(tx); } /* * Commit ZFS Intent Log transactions (itxs) to stable storage. * * When writing ZIL transactions to the on-disk representation of the * ZIL, the itxs are committed to a Log Write Block (lwb). Multiple * itxs can be committed to a single lwb. Once a lwb is written and * committed to stable storage (i.e. the lwb is written, and vdevs have * been flushed), each itx that was committed to that lwb is also * considered to be committed to stable storage. * * When an itx is committed to an lwb, the log record (lr_t) contained * by the itx is copied into the lwb's zio buffer, and once this buffer * is written to disk, it becomes an on-disk ZIL block. * * As itxs are generated, they're inserted into the ZIL's queue of * uncommitted itxs. The semantics of zil_commit() are such that it will * block until all itxs that were in the queue when it was called, are * committed to stable storage. * * If "foid" is zero, this means all "synchronous" and "asynchronous" * itxs, for all objects in the dataset, will be committed to stable * storage prior to zil_commit() returning. If "foid" is non-zero, all * "synchronous" itxs for all objects, but only "asynchronous" itxs * that correspond to the foid passed in, will be committed to stable * storage prior to zil_commit() returning. * * Generally speaking, when zil_commit() is called, the consumer doesn't * actually care about _all_ of the uncommitted itxs. Instead, they're * simply trying to waiting for a specific itx to be committed to disk, * but the interface(s) for interacting with the ZIL don't allow such * fine-grained communication. A better interface would allow a consumer * to create and assign an itx, and then pass a reference to this itx to * zil_commit(); such that zil_commit() would return as soon as that * specific itx was committed to disk (instead of waiting for _all_ * itxs to be committed). * * When a thread calls zil_commit() a special "commit itx" will be * generated, along with a corresponding "waiter" for this commit itx. * zil_commit() will wait on this waiter's CV, such that when the waiter * is marked done, and signaled, zil_commit() will return. * * This commit itx is inserted into the queue of uncommitted itxs. This * provides an easy mechanism for determining which itxs were in the * queue prior to zil_commit() having been called, and which itxs were * added after zil_commit() was called. * * The commit it is special; it doesn't have any on-disk representation. * When a commit itx is "committed" to an lwb, the waiter associated * with it is linked onto the lwb's list of waiters. Then, when that lwb * completes, each waiter on the lwb's list is marked done and signaled * -- allowing the thread waiting on the waiter to return from zil_commit(). * * It's important to point out a few critical factors that allow us * to make use of the commit itxs, commit waiters, per-lwb lists of * commit waiters, and zio completion callbacks like we're doing: * * 1. The list of waiters for each lwb is traversed, and each commit * waiter is marked "done" and signaled, in the zio completion * callback of the lwb's zio[*]. * * * Actually, the waiters are signaled in the zio completion * callback of the root zio for the DKIOCFLUSHWRITECACHE commands * that are sent to the vdevs upon completion of the lwb zio. * * 2. When the itxs are inserted into the ZIL's queue of uncommitted * itxs, the order in which they are inserted is preserved[*]; as * itxs are added to the queue, they are added to the tail of * in-memory linked lists. * * When committing the itxs to lwbs (to be written to disk), they * are committed in the same order in which the itxs were added to * the uncommitted queue's linked list(s); i.e. the linked list of * itxs to commit is traversed from head to tail, and each itx is * committed to an lwb in that order. * * * To clarify: * * - the order of "sync" itxs is preserved w.r.t. other * "sync" itxs, regardless of the corresponding objects. * - the order of "async" itxs is preserved w.r.t. other * "async" itxs corresponding to the same object. * - the order of "async" itxs is *not* preserved w.r.t. other * "async" itxs corresponding to different objects. * - the order of "sync" itxs w.r.t. "async" itxs (or vice * versa) is *not* preserved, even for itxs that correspond * to the same object. * * For more details, see: zil_itx_assign(), zil_async_to_sync(), * zil_get_commit_list(), and zil_process_commit_list(). * * 3. The lwbs represent a linked list of blocks on disk. Thus, any * lwb cannot be considered committed to stable storage, until its * "previous" lwb is also committed to stable storage. This fact, * coupled with the fact described above, means that itxs are * committed in (roughly) the order in which they were generated. * This is essential because itxs are dependent on prior itxs. * Thus, we *must not* deem an itx as being committed to stable * storage, until *all* prior itxs have also been committed to * stable storage. * * To enforce this ordering of lwb zio's, while still leveraging as * much of the underlying storage performance as possible, we rely * on two fundamental concepts: * * 1. The creation and issuance of lwb zio's is protected by * the zilog's "zl_issuer_lock", which ensures only a single * thread is creating and/or issuing lwb's at a time * 2. The "previous" lwb is a child of the "current" lwb * (leveraging the zio parent-child dependency graph) * * By relying on this parent-child zio relationship, we can have * many lwb zio's concurrently issued to the underlying storage, * but the order in which they complete will be the same order in * which they were created. */ void zil_commit(zilog_t *zilog, uint64_t foid) { /* * We should never attempt to call zil_commit on a snapshot for * a couple of reasons: * * 1. A snapshot may never be modified, thus it cannot have any * in-flight itxs that would have modified the dataset. * * 2. By design, when zil_commit() is called, a commit itx will * be assigned to this zilog; as a result, the zilog will be * dirtied. We must not dirty the zilog of a snapshot; there's * checks in the code that enforce this invariant, and will * cause a panic if it's not upheld. */ ASSERT3B(dmu_objset_is_snapshot(zilog->zl_os), ==, B_FALSE); if (zilog->zl_sync == ZFS_SYNC_DISABLED) return; if (!spa_writeable(zilog->zl_spa)) { /* * If the SPA is not writable, there should never be any * pending itxs waiting to be committed to disk. If that * weren't true, we'd skip writing those itxs out, and * would break the semantics of zil_commit(); thus, we're * verifying that truth before we return to the caller. */ ASSERT(list_is_empty(&zilog->zl_lwb_list)); ASSERT3P(zilog->zl_last_lwb_opened, ==, NULL); for (int i = 0; i < TXG_SIZE; i++) ASSERT3P(zilog->zl_itxg[i].itxg_itxs, ==, NULL); return; } /* * If the ZIL is suspended, we don't want to dirty it by calling * zil_commit_itx_assign() below, nor can we write out * lwbs like would be done in zil_commit_write(). Thus, we * simply rely on txg_wait_synced() to maintain the necessary * semantics, and avoid calling those functions altogether. */ if (zilog->zl_suspend > 0) { txg_wait_synced(zilog->zl_dmu_pool, 0); return; } zil_commit_impl(zilog, foid); } void zil_commit_impl(zilog_t *zilog, uint64_t foid) { ZIL_STAT_BUMP(zil_commit_count); /* * Move the "async" itxs for the specified foid to the "sync" * queues, such that they will be later committed (or skipped) * to an lwb when zil_process_commit_list() is called. * * Since these "async" itxs must be committed prior to this * call to zil_commit returning, we must perform this operation * before we call zil_commit_itx_assign(). */ zil_async_to_sync(zilog, foid); /* * We allocate a new "waiter" structure which will initially be * linked to the commit itx using the itx's "itx_private" field. * Since the commit itx doesn't represent any on-disk state, * when it's committed to an lwb, rather than copying the its * lr_t into the lwb's buffer, the commit itx's "waiter" will be * added to the lwb's list of waiters. Then, when the lwb is * committed to stable storage, each waiter in the lwb's list of * waiters will be marked "done", and signalled. * * We must create the waiter and assign the commit itx prior to * calling zil_commit_writer(), or else our specific commit itx * is not guaranteed to be committed to an lwb prior to calling * zil_commit_waiter(). */ zil_commit_waiter_t *zcw = zil_alloc_commit_waiter(); zil_commit_itx_assign(zilog, zcw); zil_commit_writer(zilog, zcw); zil_commit_waiter(zilog, zcw); if (zcw->zcw_zio_error != 0) { /* * If there was an error writing out the ZIL blocks that * this thread is waiting on, then we fallback to * relying on spa_sync() to write out the data this * thread is waiting on. Obviously this has performance * implications, but the expectation is for this to be * an exceptional case, and shouldn't occur often. */ DTRACE_PROBE2(zil__commit__io__error, zilog_t *, zilog, zil_commit_waiter_t *, zcw); txg_wait_synced(zilog->zl_dmu_pool, 0); } zil_free_commit_waiter(zcw); } /* * Called in syncing context to free committed log blocks and update log header. */ void zil_sync(zilog_t *zilog, dmu_tx_t *tx) { zil_header_t *zh = zil_header_in_syncing_context(zilog); uint64_t txg = dmu_tx_get_txg(tx); spa_t *spa = zilog->zl_spa; uint64_t *replayed_seq = &zilog->zl_replayed_seq[txg & TXG_MASK]; lwb_t *lwb; /* * We don't zero out zl_destroy_txg, so make sure we don't try * to destroy it twice. */ if (spa_sync_pass(spa) != 1) return; mutex_enter(&zilog->zl_lock); ASSERT(zilog->zl_stop_sync == 0); if (*replayed_seq != 0) { ASSERT(zh->zh_replay_seq < *replayed_seq); zh->zh_replay_seq = *replayed_seq; *replayed_seq = 0; } if (zilog->zl_destroy_txg == txg) { blkptr_t blk = zh->zh_log; ASSERT(list_head(&zilog->zl_lwb_list) == NULL); bzero(zh, sizeof (zil_header_t)); bzero(zilog->zl_replayed_seq, sizeof (zilog->zl_replayed_seq)); if (zilog->zl_keep_first) { /* * If this block was part of log chain that couldn't * be claimed because a device was missing during * zil_claim(), but that device later returns, * then this block could erroneously appear valid. * To guard against this, assign a new GUID to the new * log chain so it doesn't matter what blk points to. */ zil_init_log_chain(zilog, &blk); zh->zh_log = blk; } } while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { zh->zh_log = lwb->lwb_blk; if (lwb->lwb_buf != NULL || lwb->lwb_max_txg > txg) break; list_remove(&zilog->zl_lwb_list, lwb); zio_free(spa, txg, &lwb->lwb_blk); zil_free_lwb(zilog, lwb); /* * If we don't have anything left in the lwb list then * we've had an allocation failure and we need to zero * out the zil_header blkptr so that we don't end * up freeing the same block twice. */ if (list_head(&zilog->zl_lwb_list) == NULL) BP_ZERO(&zh->zh_log); } /* * Remove fastwrite on any blocks that have been pre-allocated for * the next commit. This prevents fastwrite counter pollution by * unused, long-lived LWBs. */ for (; lwb != NULL; lwb = list_next(&zilog->zl_lwb_list, lwb)) { if (lwb->lwb_fastwrite && !lwb->lwb_write_zio) { metaslab_fastwrite_unmark(zilog->zl_spa, &lwb->lwb_blk); lwb->lwb_fastwrite = 0; } } mutex_exit(&zilog->zl_lock); } /* ARGSUSED */ static int zil_lwb_cons(void *vbuf, void *unused, int kmflag) { lwb_t *lwb = vbuf; list_create(&lwb->lwb_itxs, sizeof (itx_t), offsetof(itx_t, itx_node)); list_create(&lwb->lwb_waiters, sizeof (zil_commit_waiter_t), offsetof(zil_commit_waiter_t, zcw_node)); avl_create(&lwb->lwb_vdev_tree, zil_lwb_vdev_compare, sizeof (zil_vdev_node_t), offsetof(zil_vdev_node_t, zv_node)); mutex_init(&lwb->lwb_vdev_lock, NULL, MUTEX_DEFAULT, NULL); return (0); } /* ARGSUSED */ static void zil_lwb_dest(void *vbuf, void *unused) { lwb_t *lwb = vbuf; mutex_destroy(&lwb->lwb_vdev_lock); avl_destroy(&lwb->lwb_vdev_tree); list_destroy(&lwb->lwb_waiters); list_destroy(&lwb->lwb_itxs); } void zil_init(void) { zil_lwb_cache = kmem_cache_create("zil_lwb_cache", sizeof (lwb_t), 0, zil_lwb_cons, zil_lwb_dest, NULL, NULL, NULL, 0); zil_zcw_cache = kmem_cache_create("zil_zcw_cache", sizeof (zil_commit_waiter_t), 0, NULL, NULL, NULL, NULL, NULL, 0); zil_ksp = kstat_create("zfs", 0, "zil", "misc", KSTAT_TYPE_NAMED, sizeof (zil_stats) / sizeof (kstat_named_t), KSTAT_FLAG_VIRTUAL); if (zil_ksp != NULL) { zil_ksp->ks_data = &zil_stats; kstat_install(zil_ksp); } } void zil_fini(void) { kmem_cache_destroy(zil_zcw_cache); kmem_cache_destroy(zil_lwb_cache); if (zil_ksp != NULL) { kstat_delete(zil_ksp); zil_ksp = NULL; } } void zil_set_sync(zilog_t *zilog, uint64_t sync) { zilog->zl_sync = sync; } void zil_set_logbias(zilog_t *zilog, uint64_t logbias) { zilog->zl_logbias = logbias; } zilog_t * zil_alloc(objset_t *os, zil_header_t *zh_phys) { zilog_t *zilog; zilog = kmem_zalloc(sizeof (zilog_t), KM_SLEEP); zilog->zl_header = zh_phys; zilog->zl_os = os; zilog->zl_spa = dmu_objset_spa(os); zilog->zl_dmu_pool = dmu_objset_pool(os); zilog->zl_destroy_txg = TXG_INITIAL - 1; zilog->zl_logbias = dmu_objset_logbias(os); zilog->zl_sync = dmu_objset_syncprop(os); zilog->zl_dirty_max_txg = 0; zilog->zl_last_lwb_opened = NULL; zilog->zl_last_lwb_latency = 0; zilog->zl_max_block_size = zil_maxblocksize; mutex_init(&zilog->zl_lock, NULL, MUTEX_DEFAULT, NULL); mutex_init(&zilog->zl_issuer_lock, NULL, MUTEX_DEFAULT, NULL); for (int i = 0; i < TXG_SIZE; i++) { mutex_init(&zilog->zl_itxg[i].itxg_lock, NULL, MUTEX_DEFAULT, NULL); } list_create(&zilog->zl_lwb_list, sizeof (lwb_t), offsetof(lwb_t, lwb_node)); list_create(&zilog->zl_itx_commit_list, sizeof (itx_t), offsetof(itx_t, itx_node)); cv_init(&zilog->zl_cv_suspend, NULL, CV_DEFAULT, NULL); return (zilog); } void zil_free(zilog_t *zilog) { int i; zilog->zl_stop_sync = 1; ASSERT0(zilog->zl_suspend); ASSERT0(zilog->zl_suspending); ASSERT(list_is_empty(&zilog->zl_lwb_list)); list_destroy(&zilog->zl_lwb_list); ASSERT(list_is_empty(&zilog->zl_itx_commit_list)); list_destroy(&zilog->zl_itx_commit_list); for (i = 0; i < TXG_SIZE; i++) { /* * It's possible for an itx to be generated that doesn't dirty * a txg (e.g. ztest TX_TRUNCATE). So there's no zil_clean() * callback to remove the entry. We remove those here. * * Also free up the ziltest itxs. */ if (zilog->zl_itxg[i].itxg_itxs) zil_itxg_clean(zilog->zl_itxg[i].itxg_itxs); mutex_destroy(&zilog->zl_itxg[i].itxg_lock); } mutex_destroy(&zilog->zl_issuer_lock); mutex_destroy(&zilog->zl_lock); cv_destroy(&zilog->zl_cv_suspend); kmem_free(zilog, sizeof (zilog_t)); } /* * Open an intent log. */ zilog_t * zil_open(objset_t *os, zil_get_data_t *get_data) { zilog_t *zilog = dmu_objset_zil(os); ASSERT3P(zilog->zl_get_data, ==, NULL); ASSERT3P(zilog->zl_last_lwb_opened, ==, NULL); ASSERT(list_is_empty(&zilog->zl_lwb_list)); zilog->zl_get_data = get_data; return (zilog); } /* * Close an intent log. */ void zil_close(zilog_t *zilog) { lwb_t *lwb; uint64_t txg; if (!dmu_objset_is_snapshot(zilog->zl_os)) { zil_commit(zilog, 0); } else { ASSERT3P(list_tail(&zilog->zl_lwb_list), ==, NULL); ASSERT0(zilog->zl_dirty_max_txg); ASSERT3B(zilog_is_dirty(zilog), ==, B_FALSE); } mutex_enter(&zilog->zl_lock); lwb = list_tail(&zilog->zl_lwb_list); if (lwb == NULL) txg = zilog->zl_dirty_max_txg; else txg = MAX(zilog->zl_dirty_max_txg, lwb->lwb_max_txg); mutex_exit(&zilog->zl_lock); /* * We need to use txg_wait_synced() to wait long enough for the * ZIL to be clean, and to wait for all pending lwbs to be * written out. */ if (txg != 0) txg_wait_synced(zilog->zl_dmu_pool, txg); if (zilog_is_dirty(zilog)) zfs_dbgmsg("zil (%px) is dirty, txg %llu", zilog, txg); if (txg < spa_freeze_txg(zilog->zl_spa)) VERIFY(!zilog_is_dirty(zilog)); zilog->zl_get_data = NULL; /* * We should have only one lwb left on the list; remove it now. */ mutex_enter(&zilog->zl_lock); lwb = list_head(&zilog->zl_lwb_list); if (lwb != NULL) { ASSERT3P(lwb, ==, list_tail(&zilog->zl_lwb_list)); ASSERT3S(lwb->lwb_state, !=, LWB_STATE_ISSUED); if (lwb->lwb_fastwrite) metaslab_fastwrite_unmark(zilog->zl_spa, &lwb->lwb_blk); list_remove(&zilog->zl_lwb_list, lwb); zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); zil_free_lwb(zilog, lwb); } mutex_exit(&zilog->zl_lock); } static char *suspend_tag = "zil suspending"; /* * Suspend an intent log. While in suspended mode, we still honor * synchronous semantics, but we rely on txg_wait_synced() to do it. * On old version pools, we suspend the log briefly when taking a * snapshot so that it will have an empty intent log. * * Long holds are not really intended to be used the way we do here -- * held for such a short time. A concurrent caller of dsl_dataset_long_held() * could fail. Therefore we take pains to only put a long hold if it is * actually necessary. Fortunately, it will only be necessary if the * objset is currently mounted (or the ZVOL equivalent). In that case it * will already have a long hold, so we are not really making things any worse. * * Ideally, we would locate the existing long-holder (i.e. the zfsvfs_t or * zvol_state_t), and use their mechanism to prevent their hold from being * dropped (e.g. VFS_HOLD()). However, that would be even more pain for * very little gain. * * if cookiep == NULL, this does both the suspend & resume. * Otherwise, it returns with the dataset "long held", and the cookie * should be passed into zil_resume(). */ int zil_suspend(const char *osname, void **cookiep) { objset_t *os; zilog_t *zilog; const zil_header_t *zh; int error; error = dmu_objset_hold(osname, suspend_tag, &os); if (error != 0) return (error); zilog = dmu_objset_zil(os); mutex_enter(&zilog->zl_lock); zh = zilog->zl_header; if (zh->zh_flags & ZIL_REPLAY_NEEDED) { /* unplayed log */ mutex_exit(&zilog->zl_lock); dmu_objset_rele(os, suspend_tag); return (SET_ERROR(EBUSY)); } /* * Don't put a long hold in the cases where we can avoid it. This * is when there is no cookie so we are doing a suspend & resume * (i.e. called from zil_vdev_offline()), and there's nothing to do * for the suspend because it's already suspended, or there's no ZIL. */ if (cookiep == NULL && !zilog->zl_suspending && (zilog->zl_suspend > 0 || BP_IS_HOLE(&zh->zh_log))) { mutex_exit(&zilog->zl_lock); dmu_objset_rele(os, suspend_tag); return (0); } dsl_dataset_long_hold(dmu_objset_ds(os), suspend_tag); dsl_pool_rele(dmu_objset_pool(os), suspend_tag); zilog->zl_suspend++; if (zilog->zl_suspend > 1) { /* * Someone else is already suspending it. * Just wait for them to finish. */ while (zilog->zl_suspending) cv_wait(&zilog->zl_cv_suspend, &zilog->zl_lock); mutex_exit(&zilog->zl_lock); if (cookiep == NULL) zil_resume(os); else *cookiep = os; return (0); } /* * If there is no pointer to an on-disk block, this ZIL must not * be active (e.g. filesystem not mounted), so there's nothing * to clean up. */ if (BP_IS_HOLE(&zh->zh_log)) { ASSERT(cookiep != NULL); /* fast path already handled */ *cookiep = os; mutex_exit(&zilog->zl_lock); return (0); } /* * The ZIL has work to do. Ensure that the associated encryption * key will remain mapped while we are committing the log by * grabbing a reference to it. If the key isn't loaded we have no * choice but to return an error until the wrapping key is loaded. */ if (os->os_encrypted && dsl_dataset_create_key_mapping(dmu_objset_ds(os)) != 0) { zilog->zl_suspend--; mutex_exit(&zilog->zl_lock); dsl_dataset_long_rele(dmu_objset_ds(os), suspend_tag); dsl_dataset_rele(dmu_objset_ds(os), suspend_tag); return (SET_ERROR(EACCES)); } zilog->zl_suspending = B_TRUE; mutex_exit(&zilog->zl_lock); /* * We need to use zil_commit_impl to ensure we wait for all * LWB_STATE_OPENED and LWB_STATE_ISSUED lwbs to be committed * to disk before proceeding. If we used zil_commit instead, it * would just call txg_wait_synced(), because zl_suspend is set. * txg_wait_synced() doesn't wait for these lwb's to be * LWB_STATE_FLUSH_DONE before returning. */ zil_commit_impl(zilog, 0); /* * Now that we've ensured all lwb's are LWB_STATE_FLUSH_DONE, we * use txg_wait_synced() to ensure the data from the zilog has * migrated to the main pool before calling zil_destroy(). */ txg_wait_synced(zilog->zl_dmu_pool, 0); zil_destroy(zilog, B_FALSE); mutex_enter(&zilog->zl_lock); zilog->zl_suspending = B_FALSE; cv_broadcast(&zilog->zl_cv_suspend); mutex_exit(&zilog->zl_lock); if (os->os_encrypted) dsl_dataset_remove_key_mapping(dmu_objset_ds(os)); if (cookiep == NULL) zil_resume(os); else *cookiep = os; return (0); } void zil_resume(void *cookie) { objset_t *os = cookie; zilog_t *zilog = dmu_objset_zil(os); mutex_enter(&zilog->zl_lock); ASSERT(zilog->zl_suspend != 0); zilog->zl_suspend--; mutex_exit(&zilog->zl_lock); dsl_dataset_long_rele(dmu_objset_ds(os), suspend_tag); dsl_dataset_rele(dmu_objset_ds(os), suspend_tag); } typedef struct zil_replay_arg { zil_replay_func_t **zr_replay; void *zr_arg; boolean_t zr_byteswap; char *zr_lr; } zil_replay_arg_t; static int zil_replay_error(zilog_t *zilog, const lr_t *lr, int error) { char name[ZFS_MAX_DATASET_NAME_LEN]; zilog->zl_replaying_seq--; /* didn't actually replay this one */ dmu_objset_name(zilog->zl_os, name); cmn_err(CE_WARN, "ZFS replay transaction error %d, " "dataset %s, seq 0x%llx, txtype %llu %s\n", error, name, (u_longlong_t)lr->lrc_seq, (u_longlong_t)(lr->lrc_txtype & ~TX_CI), (lr->lrc_txtype & TX_CI) ? "CI" : ""); return (error); } static int zil_replay_log_record(zilog_t *zilog, const lr_t *lr, void *zra, uint64_t claim_txg) { zil_replay_arg_t *zr = zra; const zil_header_t *zh = zilog->zl_header; uint64_t reclen = lr->lrc_reclen; uint64_t txtype = lr->lrc_txtype; int error = 0; zilog->zl_replaying_seq = lr->lrc_seq; if (lr->lrc_seq <= zh->zh_replay_seq) /* already replayed */ return (0); if (lr->lrc_txg < claim_txg) /* already committed */ return (0); /* Strip case-insensitive bit, still present in log record */ txtype &= ~TX_CI; if (txtype == 0 || txtype >= TX_MAX_TYPE) return (zil_replay_error(zilog, lr, EINVAL)); /* * If this record type can be logged out of order, the object * (lr_foid) may no longer exist. That's legitimate, not an error. */ if (TX_OOO(txtype)) { error = dmu_object_info(zilog->zl_os, LR_FOID_GET_OBJ(((lr_ooo_t *)lr)->lr_foid), NULL); if (error == ENOENT || error == EEXIST) return (0); } /* * Make a copy of the data so we can revise and extend it. */ bcopy(lr, zr->zr_lr, reclen); /* * If this is a TX_WRITE with a blkptr, suck in the data. */ if (txtype == TX_WRITE && reclen == sizeof (lr_write_t)) { error = zil_read_log_data(zilog, (lr_write_t *)lr, zr->zr_lr + reclen); if (error != 0) return (zil_replay_error(zilog, lr, error)); } /* * The log block containing this lr may have been byteswapped * so that we can easily examine common fields like lrc_txtype. * However, the log is a mix of different record types, and only the * replay vectors know how to byteswap their records. Therefore, if * the lr was byteswapped, undo it before invoking the replay vector. */ if (zr->zr_byteswap) byteswap_uint64_array(zr->zr_lr, reclen); /* * We must now do two things atomically: replay this log record, * and update the log header sequence number to reflect the fact that * we did so. At the end of each replay function the sequence number * is updated if we are in replay mode. */ error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, zr->zr_byteswap); if (error != 0) { /* * The DMU's dnode layer doesn't see removes until the txg * commits, so a subsequent claim can spuriously fail with * EEXIST. So if we receive any error we try syncing out * any removes then retry the transaction. Note that we * specify B_FALSE for byteswap now, so we don't do it twice. */ txg_wait_synced(spa_get_dsl(zilog->zl_spa), 0); error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, B_FALSE); if (error != 0) return (zil_replay_error(zilog, lr, error)); } return (0); } /* ARGSUSED */ static int zil_incr_blks(zilog_t *zilog, const blkptr_t *bp, void *arg, uint64_t claim_txg) { zilog->zl_replay_blks++; return (0); } /* * If this dataset has a non-empty intent log, replay it and destroy it. */ void zil_replay(objset_t *os, void *arg, zil_replay_func_t *replay_func[TX_MAX_TYPE]) { zilog_t *zilog = dmu_objset_zil(os); const zil_header_t *zh = zilog->zl_header; zil_replay_arg_t zr; if ((zh->zh_flags & ZIL_REPLAY_NEEDED) == 0) { zil_destroy(zilog, B_TRUE); return; } zr.zr_replay = replay_func; zr.zr_arg = arg; zr.zr_byteswap = BP_SHOULD_BYTESWAP(&zh->zh_log); zr.zr_lr = vmem_alloc(2 * SPA_MAXBLOCKSIZE, KM_SLEEP); /* * Wait for in-progress removes to sync before starting replay. */ txg_wait_synced(zilog->zl_dmu_pool, 0); zilog->zl_replay = B_TRUE; zilog->zl_replay_time = ddi_get_lbolt(); ASSERT(zilog->zl_replay_blks == 0); (void) zil_parse(zilog, zil_incr_blks, zil_replay_log_record, &zr, zh->zh_claim_txg, B_TRUE); vmem_free(zr.zr_lr, 2 * SPA_MAXBLOCKSIZE); zil_destroy(zilog, B_FALSE); txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); zilog->zl_replay = B_FALSE; } boolean_t zil_replaying(zilog_t *zilog, dmu_tx_t *tx) { if (zilog->zl_sync == ZFS_SYNC_DISABLED) return (B_TRUE); if (zilog->zl_replay) { dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); zilog->zl_replayed_seq[dmu_tx_get_txg(tx) & TXG_MASK] = zilog->zl_replaying_seq; return (B_TRUE); } return (B_FALSE); } /* ARGSUSED */ int zil_reset(const char *osname, void *arg) { int error; error = zil_suspend(osname, NULL); /* EACCES means crypto key not loaded */ if ((error == EACCES) || (error == EBUSY)) return (SET_ERROR(error)); if (error != 0) return (SET_ERROR(EEXIST)); return (0); } EXPORT_SYMBOL(zil_alloc); EXPORT_SYMBOL(zil_free); EXPORT_SYMBOL(zil_open); EXPORT_SYMBOL(zil_close); EXPORT_SYMBOL(zil_replay); EXPORT_SYMBOL(zil_replaying); EXPORT_SYMBOL(zil_destroy); EXPORT_SYMBOL(zil_destroy_sync); EXPORT_SYMBOL(zil_itx_create); EXPORT_SYMBOL(zil_itx_destroy); EXPORT_SYMBOL(zil_itx_assign); EXPORT_SYMBOL(zil_commit); EXPORT_SYMBOL(zil_claim); EXPORT_SYMBOL(zil_check_log_chain); EXPORT_SYMBOL(zil_sync); EXPORT_SYMBOL(zil_clean); EXPORT_SYMBOL(zil_suspend); EXPORT_SYMBOL(zil_resume); EXPORT_SYMBOL(zil_lwb_add_block); EXPORT_SYMBOL(zil_bp_tree_add); EXPORT_SYMBOL(zil_set_sync); EXPORT_SYMBOL(zil_set_logbias); /* BEGIN CSTYLED */ ZFS_MODULE_PARAM(zfs, zfs_, commit_timeout_pct, INT, ZMOD_RW, "ZIL block open timeout percentage"); ZFS_MODULE_PARAM(zfs_zil, zil_, replay_disable, INT, ZMOD_RW, "Disable intent logging replay"); ZFS_MODULE_PARAM(zfs_zil, zil_, nocacheflush, INT, ZMOD_RW, "Disable ZIL cache flushes"); ZFS_MODULE_PARAM(zfs_zil, zil_, slog_bulk, ULONG, ZMOD_RW, "Limit in bytes slog sync writes per commit"); ZFS_MODULE_PARAM(zfs_zil, zil_, maxblocksize, INT, ZMOD_RW, "Limit in bytes of ZIL log block size"); /* END CSTYLED */ diff --git a/module/zfs/zio.c b/module/zfs/zio.c index 3c2b731f7c4e..41b347b76a1a 100644 --- a/module/zfs/zio.c +++ b/module/zfs/zio.c @@ -1,4983 +1,4983 @@ /* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. * Copyright (c) 2011, 2020 by Delphix. All rights reserved. * Copyright (c) 2011 Nexenta Systems, Inc. All rights reserved. * Copyright (c) 2017, Intel Corporation. * Copyright (c) 2019, Klara Inc. * Copyright (c) 2019, Allan Jude */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * ========================================================================== * I/O type descriptions * ========================================================================== */ const char *zio_type_name[ZIO_TYPES] = { /* * Note: Linux kernel thread name length is limited * so these names will differ from upstream open zfs. */ "z_null", "z_rd", "z_wr", "z_fr", "z_cl", "z_ioctl", "z_trim" }; int zio_dva_throttle_enabled = B_TRUE; int zio_deadman_log_all = B_FALSE; /* * ========================================================================== * I/O kmem caches * ========================================================================== */ kmem_cache_t *zio_cache; kmem_cache_t *zio_link_cache; kmem_cache_t *zio_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; kmem_cache_t *zio_data_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; #if defined(ZFS_DEBUG) && !defined(_KERNEL) uint64_t zio_buf_cache_allocs[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; uint64_t zio_buf_cache_frees[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; #endif /* Mark IOs as "slow" if they take longer than 30 seconds */ int zio_slow_io_ms = (30 * MILLISEC); #define BP_SPANB(indblkshift, level) \ (((uint64_t)1) << ((level) * ((indblkshift) - SPA_BLKPTRSHIFT))) #define COMPARE_META_LEVEL 0x80000000ul /* * The following actions directly effect the spa's sync-to-convergence logic. * The values below define the sync pass when we start performing the action. * Care should be taken when changing these values as they directly impact * spa_sync() performance. Tuning these values may introduce subtle performance * pathologies and should only be done in the context of performance analysis. * These tunables will eventually be removed and replaced with #defines once * enough analysis has been done to determine optimal values. * * The 'zfs_sync_pass_deferred_free' pass must be greater than 1 to ensure that * regular blocks are not deferred. * * Starting in sync pass 8 (zfs_sync_pass_dont_compress), we disable * compression (including of metadata). In practice, we don't have this * many sync passes, so this has no effect. * * The original intent was that disabling compression would help the sync * passes to converge. However, in practice disabling compression increases * the average number of sync passes, because when we turn compression off, a * lot of block's size will change and thus we have to re-allocate (not * overwrite) them. It also increases the number of 128KB allocations (e.g. * for indirect blocks and spacemaps) because these will not be compressed. * The 128K allocations are especially detrimental to performance on highly * fragmented systems, which may have very few free segments of this size, * and may need to load new metaslabs to satisfy 128K allocations. */ int zfs_sync_pass_deferred_free = 2; /* defer frees starting in this pass */ int zfs_sync_pass_dont_compress = 8; /* don't compress starting in this pass */ int zfs_sync_pass_rewrite = 2; /* rewrite new bps starting in this pass */ /* * An allocating zio is one that either currently has the DVA allocate * stage set or will have it later in its lifetime. */ #define IO_IS_ALLOCATING(zio) ((zio)->io_orig_pipeline & ZIO_STAGE_DVA_ALLOCATE) /* * Enable smaller cores by excluding metadata * allocations as well. */ int zio_exclude_metadata = 0; int zio_requeue_io_start_cut_in_line = 1; #ifdef ZFS_DEBUG int zio_buf_debug_limit = 16384; #else int zio_buf_debug_limit = 0; #endif static inline void __zio_execute(zio_t *zio); static void zio_taskq_dispatch(zio_t *, zio_taskq_type_t, boolean_t); void zio_init(void) { size_t c; zio_cache = kmem_cache_create("zio_cache", sizeof (zio_t), 0, NULL, NULL, NULL, NULL, NULL, 0); zio_link_cache = kmem_cache_create("zio_link_cache", sizeof (zio_link_t), 0, NULL, NULL, NULL, NULL, NULL, 0); /* * For small buffers, we want a cache for each multiple of * SPA_MINBLOCKSIZE. For larger buffers, we want a cache * for each quarter-power of 2. */ for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { size_t size = (c + 1) << SPA_MINBLOCKSHIFT; size_t p2 = size; size_t align = 0; size_t data_cflags, cflags; data_cflags = KMC_NODEBUG; cflags = (zio_exclude_metadata || size > zio_buf_debug_limit) ? KMC_NODEBUG : 0; #if defined(_ILP32) && defined(_KERNEL) /* * Cache size limited to 1M on 32-bit platforms until ARC * buffers no longer require virtual address space. */ if (size > zfs_max_recordsize) break; #endif while (!ISP2(p2)) p2 &= p2 - 1; #ifndef _KERNEL /* * If we are using watchpoints, put each buffer on its own page, * to eliminate the performance overhead of trapping to the * kernel when modifying a non-watched buffer that shares the * page with a watched buffer. */ if (arc_watch && !IS_P2ALIGNED(size, PAGESIZE)) continue; /* * Here's the problem - on 4K native devices in userland on * Linux using O_DIRECT, buffers must be 4K aligned or I/O * will fail with EINVAL, causing zdb (and others) to coredump. * Since userland probably doesn't need optimized buffer caches, * we just force 4K alignment on everything. */ align = 8 * SPA_MINBLOCKSIZE; #else if (size < PAGESIZE) { align = SPA_MINBLOCKSIZE; } else if (IS_P2ALIGNED(size, p2 >> 2)) { align = PAGESIZE; } #endif if (align != 0) { char name[36]; (void) snprintf(name, sizeof (name), "zio_buf_%lu", (ulong_t)size); zio_buf_cache[c] = kmem_cache_create(name, size, align, NULL, NULL, NULL, NULL, NULL, cflags); (void) snprintf(name, sizeof (name), "zio_data_buf_%lu", (ulong_t)size); zio_data_buf_cache[c] = kmem_cache_create(name, size, align, NULL, NULL, NULL, NULL, NULL, data_cflags); } } while (--c != 0) { ASSERT(zio_buf_cache[c] != NULL); if (zio_buf_cache[c - 1] == NULL) zio_buf_cache[c - 1] = zio_buf_cache[c]; ASSERT(zio_data_buf_cache[c] != NULL); if (zio_data_buf_cache[c - 1] == NULL) zio_data_buf_cache[c - 1] = zio_data_buf_cache[c]; } zio_inject_init(); lz4_init(); } void zio_fini(void) { size_t c; kmem_cache_t *last_cache = NULL; kmem_cache_t *last_data_cache = NULL; for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { #ifdef _ILP32 /* * Cache size limited to 1M on 32-bit platforms until ARC * buffers no longer require virtual address space. */ if (((c + 1) << SPA_MINBLOCKSHIFT) > zfs_max_recordsize) break; #endif #if defined(ZFS_DEBUG) && !defined(_KERNEL) if (zio_buf_cache_allocs[c] != zio_buf_cache_frees[c]) (void) printf("zio_fini: [%d] %llu != %llu\n", (int)((c + 1) << SPA_MINBLOCKSHIFT), (long long unsigned)zio_buf_cache_allocs[c], (long long unsigned)zio_buf_cache_frees[c]); #endif if (zio_buf_cache[c] != last_cache) { last_cache = zio_buf_cache[c]; kmem_cache_destroy(zio_buf_cache[c]); } zio_buf_cache[c] = NULL; if (zio_data_buf_cache[c] != last_data_cache) { last_data_cache = zio_data_buf_cache[c]; kmem_cache_destroy(zio_data_buf_cache[c]); } zio_data_buf_cache[c] = NULL; } kmem_cache_destroy(zio_link_cache); kmem_cache_destroy(zio_cache); zio_inject_fini(); lz4_fini(); } /* * ========================================================================== * Allocate and free I/O buffers * ========================================================================== */ /* * Use zio_buf_alloc to allocate ZFS metadata. This data will appear in a * crashdump if the kernel panics, so use it judiciously. Obviously, it's * useful to inspect ZFS metadata, but if possible, we should avoid keeping * excess / transient data in-core during a crashdump. */ void * zio_buf_alloc(size_t size) { size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); #if defined(ZFS_DEBUG) && !defined(_KERNEL) atomic_add_64(&zio_buf_cache_allocs[c], 1); #endif return (kmem_cache_alloc(zio_buf_cache[c], KM_PUSHPAGE)); } /* * Use zio_data_buf_alloc to allocate data. The data will not appear in a * crashdump if the kernel panics. This exists so that we will limit the amount * of ZFS data that shows up in a kernel crashdump. (Thus reducing the amount * of kernel heap dumped to disk when the kernel panics) */ void * zio_data_buf_alloc(size_t size) { size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); return (kmem_cache_alloc(zio_data_buf_cache[c], KM_PUSHPAGE)); } void zio_buf_free(void *buf, size_t size) { size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); #if defined(ZFS_DEBUG) && !defined(_KERNEL) atomic_add_64(&zio_buf_cache_frees[c], 1); #endif kmem_cache_free(zio_buf_cache[c], buf); } void zio_data_buf_free(void *buf, size_t size) { size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); kmem_cache_free(zio_data_buf_cache[c], buf); } static void zio_abd_free(void *abd, size_t size) { abd_free((abd_t *)abd); } /* * ========================================================================== * Push and pop I/O transform buffers * ========================================================================== */ void zio_push_transform(zio_t *zio, abd_t *data, uint64_t size, uint64_t bufsize, zio_transform_func_t *transform) { zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP); zt->zt_orig_abd = zio->io_abd; zt->zt_orig_size = zio->io_size; zt->zt_bufsize = bufsize; zt->zt_transform = transform; zt->zt_next = zio->io_transform_stack; zio->io_transform_stack = zt; zio->io_abd = data; zio->io_size = size; } void zio_pop_transforms(zio_t *zio) { zio_transform_t *zt; while ((zt = zio->io_transform_stack) != NULL) { if (zt->zt_transform != NULL) zt->zt_transform(zio, zt->zt_orig_abd, zt->zt_orig_size); if (zt->zt_bufsize != 0) abd_free(zio->io_abd); zio->io_abd = zt->zt_orig_abd; zio->io_size = zt->zt_orig_size; zio->io_transform_stack = zt->zt_next; kmem_free(zt, sizeof (zio_transform_t)); } } /* * ========================================================================== * I/O transform callbacks for subblocks, decompression, and decryption * ========================================================================== */ static void zio_subblock(zio_t *zio, abd_t *data, uint64_t size) { ASSERT(zio->io_size > size); if (zio->io_type == ZIO_TYPE_READ) abd_copy(data, zio->io_abd, size); } static void zio_decompress(zio_t *zio, abd_t *data, uint64_t size) { if (zio->io_error == 0) { void *tmp = abd_borrow_buf(data, size); int ret = zio_decompress_data(BP_GET_COMPRESS(zio->io_bp), zio->io_abd, tmp, zio->io_size, size, &zio->io_prop.zp_complevel); abd_return_buf_copy(data, tmp, size); if (zio_injection_enabled && ret == 0) ret = zio_handle_fault_injection(zio, EINVAL); if (ret != 0) zio->io_error = SET_ERROR(EIO); } } static void zio_decrypt(zio_t *zio, abd_t *data, uint64_t size) { int ret; void *tmp; blkptr_t *bp = zio->io_bp; spa_t *spa = zio->io_spa; uint64_t dsobj = zio->io_bookmark.zb_objset; uint64_t lsize = BP_GET_LSIZE(bp); dmu_object_type_t ot = BP_GET_TYPE(bp); uint8_t salt[ZIO_DATA_SALT_LEN]; uint8_t iv[ZIO_DATA_IV_LEN]; uint8_t mac[ZIO_DATA_MAC_LEN]; boolean_t no_crypt = B_FALSE; ASSERT(BP_USES_CRYPT(bp)); ASSERT3U(size, !=, 0); if (zio->io_error != 0) return; /* * Verify the cksum of MACs stored in an indirect bp. It will always * be possible to verify this since it does not require an encryption * key. */ if (BP_HAS_INDIRECT_MAC_CKSUM(bp)) { zio_crypt_decode_mac_bp(bp, mac); if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF) { /* * We haven't decompressed the data yet, but * zio_crypt_do_indirect_mac_checksum() requires * decompressed data to be able to parse out the MACs * from the indirect block. We decompress it now and * throw away the result after we are finished. */ tmp = zio_buf_alloc(lsize); ret = zio_decompress_data(BP_GET_COMPRESS(bp), zio->io_abd, tmp, zio->io_size, lsize, &zio->io_prop.zp_complevel); if (ret != 0) { ret = SET_ERROR(EIO); goto error; } ret = zio_crypt_do_indirect_mac_checksum(B_FALSE, tmp, lsize, BP_SHOULD_BYTESWAP(bp), mac); zio_buf_free(tmp, lsize); } else { ret = zio_crypt_do_indirect_mac_checksum_abd(B_FALSE, zio->io_abd, size, BP_SHOULD_BYTESWAP(bp), mac); } abd_copy(data, zio->io_abd, size); if (zio_injection_enabled && ot != DMU_OT_DNODE && ret == 0) { ret = zio_handle_decrypt_injection(spa, &zio->io_bookmark, ot, ECKSUM); } if (ret != 0) goto error; return; } /* * If this is an authenticated block, just check the MAC. It would be * nice to separate this out into its own flag, but for the moment * enum zio_flag is out of bits. */ if (BP_IS_AUTHENTICATED(bp)) { if (ot == DMU_OT_OBJSET) { ret = spa_do_crypt_objset_mac_abd(B_FALSE, spa, dsobj, zio->io_abd, size, BP_SHOULD_BYTESWAP(bp)); } else { zio_crypt_decode_mac_bp(bp, mac); ret = spa_do_crypt_mac_abd(B_FALSE, spa, dsobj, zio->io_abd, size, mac); if (zio_injection_enabled && ret == 0) { ret = zio_handle_decrypt_injection(spa, &zio->io_bookmark, ot, ECKSUM); } } abd_copy(data, zio->io_abd, size); if (ret != 0) goto error; return; } zio_crypt_decode_params_bp(bp, salt, iv); if (ot == DMU_OT_INTENT_LOG) { tmp = abd_borrow_buf_copy(zio->io_abd, sizeof (zil_chain_t)); zio_crypt_decode_mac_zil(tmp, mac); abd_return_buf(zio->io_abd, tmp, sizeof (zil_chain_t)); } else { zio_crypt_decode_mac_bp(bp, mac); } ret = spa_do_crypt_abd(B_FALSE, spa, &zio->io_bookmark, BP_GET_TYPE(bp), BP_GET_DEDUP(bp), BP_SHOULD_BYTESWAP(bp), salt, iv, mac, size, data, zio->io_abd, &no_crypt); if (no_crypt) abd_copy(data, zio->io_abd, size); if (ret != 0) goto error; return; error: /* assert that the key was found unless this was speculative */ ASSERT(ret != EACCES || (zio->io_flags & ZIO_FLAG_SPECULATIVE)); /* * If there was a decryption / authentication error return EIO as * the io_error. If this was not a speculative zio, create an ereport. */ if (ret == ECKSUM) { zio->io_error = SET_ERROR(EIO); if ((zio->io_flags & ZIO_FLAG_SPECULATIVE) == 0) { spa_log_error(spa, &zio->io_bookmark); (void) zfs_ereport_post(FM_EREPORT_ZFS_AUTHENTICATION, spa, NULL, &zio->io_bookmark, zio, 0); } } else { zio->io_error = ret; } } /* * ========================================================================== * I/O parent/child relationships and pipeline interlocks * ========================================================================== */ zio_t * zio_walk_parents(zio_t *cio, zio_link_t **zl) { list_t *pl = &cio->io_parent_list; *zl = (*zl == NULL) ? list_head(pl) : list_next(pl, *zl); if (*zl == NULL) return (NULL); ASSERT((*zl)->zl_child == cio); return ((*zl)->zl_parent); } zio_t * zio_walk_children(zio_t *pio, zio_link_t **zl) { list_t *cl = &pio->io_child_list; ASSERT(MUTEX_HELD(&pio->io_lock)); *zl = (*zl == NULL) ? list_head(cl) : list_next(cl, *zl); if (*zl == NULL) return (NULL); ASSERT((*zl)->zl_parent == pio); return ((*zl)->zl_child); } zio_t * zio_unique_parent(zio_t *cio) { zio_link_t *zl = NULL; zio_t *pio = zio_walk_parents(cio, &zl); VERIFY3P(zio_walk_parents(cio, &zl), ==, NULL); return (pio); } void zio_add_child(zio_t *pio, zio_t *cio) { zio_link_t *zl = kmem_cache_alloc(zio_link_cache, KM_SLEEP); /* * Logical I/Os can have logical, gang, or vdev children. * Gang I/Os can have gang or vdev children. * Vdev I/Os can only have vdev children. * The following ASSERT captures all of these constraints. */ ASSERT3S(cio->io_child_type, <=, pio->io_child_type); zl->zl_parent = pio; zl->zl_child = cio; mutex_enter(&pio->io_lock); mutex_enter(&cio->io_lock); ASSERT(pio->io_state[ZIO_WAIT_DONE] == 0); for (int w = 0; w < ZIO_WAIT_TYPES; w++) pio->io_children[cio->io_child_type][w] += !cio->io_state[w]; list_insert_head(&pio->io_child_list, zl); list_insert_head(&cio->io_parent_list, zl); pio->io_child_count++; cio->io_parent_count++; mutex_exit(&cio->io_lock); mutex_exit(&pio->io_lock); } static void zio_remove_child(zio_t *pio, zio_t *cio, zio_link_t *zl) { ASSERT(zl->zl_parent == pio); ASSERT(zl->zl_child == cio); mutex_enter(&pio->io_lock); mutex_enter(&cio->io_lock); list_remove(&pio->io_child_list, zl); list_remove(&cio->io_parent_list, zl); pio->io_child_count--; cio->io_parent_count--; mutex_exit(&cio->io_lock); mutex_exit(&pio->io_lock); kmem_cache_free(zio_link_cache, zl); } static boolean_t zio_wait_for_children(zio_t *zio, uint8_t childbits, enum zio_wait_type wait) { boolean_t waiting = B_FALSE; mutex_enter(&zio->io_lock); ASSERT(zio->io_stall == NULL); for (int c = 0; c < ZIO_CHILD_TYPES; c++) { if (!(ZIO_CHILD_BIT_IS_SET(childbits, c))) continue; uint64_t *countp = &zio->io_children[c][wait]; if (*countp != 0) { zio->io_stage >>= 1; ASSERT3U(zio->io_stage, !=, ZIO_STAGE_OPEN); zio->io_stall = countp; waiting = B_TRUE; break; } } mutex_exit(&zio->io_lock); return (waiting); } __attribute__((always_inline)) static inline void zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait, zio_t **next_to_executep) { uint64_t *countp = &pio->io_children[zio->io_child_type][wait]; int *errorp = &pio->io_child_error[zio->io_child_type]; mutex_enter(&pio->io_lock); if (zio->io_error && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE)) *errorp = zio_worst_error(*errorp, zio->io_error); pio->io_reexecute |= zio->io_reexecute; ASSERT3U(*countp, >, 0); (*countp)--; if (*countp == 0 && pio->io_stall == countp) { zio_taskq_type_t type = pio->io_stage < ZIO_STAGE_VDEV_IO_START ? ZIO_TASKQ_ISSUE : ZIO_TASKQ_INTERRUPT; pio->io_stall = NULL; mutex_exit(&pio->io_lock); /* * If we can tell the caller to execute this parent next, do * so. Otherwise dispatch the parent zio as its own task. * * Having the caller execute the parent when possible reduces * locking on the zio taskq's, reduces context switch * overhead, and has no recursion penalty. Note that one * read from disk typically causes at least 3 zio's: a * zio_null(), the logical zio_read(), and then a physical * zio. When the physical ZIO completes, we are able to call * zio_done() on all 3 of these zio's from one invocation of * zio_execute() by returning the parent back to * zio_execute(). Since the parent isn't executed until this * thread returns back to zio_execute(), the caller should do * so promptly. * * In other cases, dispatching the parent prevents * overflowing the stack when we have deeply nested * parent-child relationships, as we do with the "mega zio" * of writes for spa_sync(), and the chain of ZIL blocks. */ if (next_to_executep != NULL && *next_to_executep == NULL) { *next_to_executep = pio; } else { zio_taskq_dispatch(pio, type, B_FALSE); } } else { mutex_exit(&pio->io_lock); } } static void zio_inherit_child_errors(zio_t *zio, enum zio_child c) { if (zio->io_child_error[c] != 0 && zio->io_error == 0) zio->io_error = zio->io_child_error[c]; } int zio_bookmark_compare(const void *x1, const void *x2) { const zio_t *z1 = x1; const zio_t *z2 = x2; if (z1->io_bookmark.zb_objset < z2->io_bookmark.zb_objset) return (-1); if (z1->io_bookmark.zb_objset > z2->io_bookmark.zb_objset) return (1); if (z1->io_bookmark.zb_object < z2->io_bookmark.zb_object) return (-1); if (z1->io_bookmark.zb_object > z2->io_bookmark.zb_object) return (1); if (z1->io_bookmark.zb_level < z2->io_bookmark.zb_level) return (-1); if (z1->io_bookmark.zb_level > z2->io_bookmark.zb_level) return (1); if (z1->io_bookmark.zb_blkid < z2->io_bookmark.zb_blkid) return (-1); if (z1->io_bookmark.zb_blkid > z2->io_bookmark.zb_blkid) return (1); if (z1 < z2) return (-1); if (z1 > z2) return (1); return (0); } /* * ========================================================================== * Create the various types of I/O (read, write, free, etc) * ========================================================================== */ static zio_t * zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, abd_t *data, uint64_t lsize, uint64_t psize, zio_done_func_t *done, void *private, zio_type_t type, zio_priority_t priority, enum zio_flag flags, vdev_t *vd, uint64_t offset, const zbookmark_phys_t *zb, enum zio_stage stage, enum zio_stage pipeline) { zio_t *zio; IMPLY(type != ZIO_TYPE_TRIM, psize <= SPA_MAXBLOCKSIZE); ASSERT(P2PHASE(psize, SPA_MINBLOCKSIZE) == 0); ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0); ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER)); ASSERT(!bp || !(flags & ZIO_FLAG_CONFIG_WRITER)); ASSERT(vd || stage == ZIO_STAGE_OPEN); IMPLY(lsize != psize, (flags & ZIO_FLAG_RAW_COMPRESS) != 0); zio = kmem_cache_alloc(zio_cache, KM_SLEEP); bzero(zio, sizeof (zio_t)); mutex_init(&zio->io_lock, NULL, MUTEX_NOLOCKDEP, NULL); cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL); list_create(&zio->io_parent_list, sizeof (zio_link_t), offsetof(zio_link_t, zl_parent_node)); list_create(&zio->io_child_list, sizeof (zio_link_t), offsetof(zio_link_t, zl_child_node)); metaslab_trace_init(&zio->io_alloc_list); if (vd != NULL) zio->io_child_type = ZIO_CHILD_VDEV; else if (flags & ZIO_FLAG_GANG_CHILD) zio->io_child_type = ZIO_CHILD_GANG; else if (flags & ZIO_FLAG_DDT_CHILD) zio->io_child_type = ZIO_CHILD_DDT; else zio->io_child_type = ZIO_CHILD_LOGICAL; if (bp != NULL) { zio->io_bp = (blkptr_t *)bp; zio->io_bp_copy = *bp; zio->io_bp_orig = *bp; if (type != ZIO_TYPE_WRITE || zio->io_child_type == ZIO_CHILD_DDT) zio->io_bp = &zio->io_bp_copy; /* so caller can free */ if (zio->io_child_type == ZIO_CHILD_LOGICAL) zio->io_logical = zio; if (zio->io_child_type > ZIO_CHILD_GANG && BP_IS_GANG(bp)) pipeline |= ZIO_GANG_STAGES; } zio->io_spa = spa; zio->io_txg = txg; zio->io_done = done; zio->io_private = private; zio->io_type = type; zio->io_priority = priority; zio->io_vd = vd; zio->io_offset = offset; zio->io_orig_abd = zio->io_abd = data; zio->io_orig_size = zio->io_size = psize; zio->io_lsize = lsize; zio->io_orig_flags = zio->io_flags = flags; zio->io_orig_stage = zio->io_stage = stage; zio->io_orig_pipeline = zio->io_pipeline = pipeline; zio->io_pipeline_trace = ZIO_STAGE_OPEN; zio->io_state[ZIO_WAIT_READY] = (stage >= ZIO_STAGE_READY); zio->io_state[ZIO_WAIT_DONE] = (stage >= ZIO_STAGE_DONE); if (zb != NULL) zio->io_bookmark = *zb; if (pio != NULL) { if (zio->io_metaslab_class == NULL) zio->io_metaslab_class = pio->io_metaslab_class; if (zio->io_logical == NULL) zio->io_logical = pio->io_logical; if (zio->io_child_type == ZIO_CHILD_GANG) zio->io_gang_leader = pio->io_gang_leader; zio_add_child(pio, zio); } taskq_init_ent(&zio->io_tqent); return (zio); } static void zio_destroy(zio_t *zio) { metaslab_trace_fini(&zio->io_alloc_list); list_destroy(&zio->io_parent_list); list_destroy(&zio->io_child_list); mutex_destroy(&zio->io_lock); cv_destroy(&zio->io_cv); kmem_cache_free(zio_cache, zio); } zio_t * zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, zio_done_func_t *done, void *private, enum zio_flag flags) { zio_t *zio; zio = zio_create(pio, spa, 0, NULL, NULL, 0, 0, done, private, ZIO_TYPE_NULL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL, ZIO_STAGE_OPEN, ZIO_INTERLOCK_PIPELINE); return (zio); } zio_t * zio_root(spa_t *spa, zio_done_func_t *done, void *private, enum zio_flag flags) { return (zio_null(NULL, spa, NULL, done, private, flags)); } static int zfs_blkptr_verify_log(spa_t *spa, const blkptr_t *bp, enum blk_verify_flag blk_verify, const char *fmt, ...) { va_list adx; char buf[256]; va_start(adx, fmt); (void) vsnprintf(buf, sizeof (buf), fmt, adx); va_end(adx); switch (blk_verify) { case BLK_VERIFY_HALT: dprintf_bp(bp, "blkptr at %p dprintf_bp():", bp); zfs_panic_recover("%s: %s", spa_name(spa), buf); break; case BLK_VERIFY_LOG: zfs_dbgmsg("%s: %s", spa_name(spa), buf); break; case BLK_VERIFY_ONLY: break; } return (1); } /* * Verify the block pointer fields contain reasonable values. This means * it only contains known object types, checksum/compression identifiers, * block sizes within the maximum allowed limits, valid DVAs, etc. * * If everything checks out B_TRUE is returned. The zfs_blkptr_verify * argument controls the behavior when an invalid field is detected. * * Modes for zfs_blkptr_verify: * 1) BLK_VERIFY_ONLY (evaluate the block) * 2) BLK_VERIFY_LOG (evaluate the block and log problems) * 3) BLK_VERIFY_HALT (call zfs_panic_recover on error) */ boolean_t zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp, boolean_t config_held, enum blk_verify_flag blk_verify) { int errors = 0; if (!DMU_OT_IS_VALID(BP_GET_TYPE(bp))) { errors += zfs_blkptr_verify_log(spa, bp, blk_verify, "blkptr at %p has invalid TYPE %llu", bp, (longlong_t)BP_GET_TYPE(bp)); } if (BP_GET_CHECKSUM(bp) >= ZIO_CHECKSUM_FUNCTIONS || BP_GET_CHECKSUM(bp) <= ZIO_CHECKSUM_ON) { errors += zfs_blkptr_verify_log(spa, bp, blk_verify, "blkptr at %p has invalid CHECKSUM %llu", bp, (longlong_t)BP_GET_CHECKSUM(bp)); } if (BP_GET_COMPRESS(bp) >= ZIO_COMPRESS_FUNCTIONS || BP_GET_COMPRESS(bp) <= ZIO_COMPRESS_ON) { errors += zfs_blkptr_verify_log(spa, bp, blk_verify, "blkptr at %p has invalid COMPRESS %llu", bp, (longlong_t)BP_GET_COMPRESS(bp)); } if (BP_GET_LSIZE(bp) > SPA_MAXBLOCKSIZE) { errors += zfs_blkptr_verify_log(spa, bp, blk_verify, "blkptr at %p has invalid LSIZE %llu", bp, (longlong_t)BP_GET_LSIZE(bp)); } if (BP_GET_PSIZE(bp) > SPA_MAXBLOCKSIZE) { errors += zfs_blkptr_verify_log(spa, bp, blk_verify, "blkptr at %p has invalid PSIZE %llu", bp, (longlong_t)BP_GET_PSIZE(bp)); } if (BP_IS_EMBEDDED(bp)) { if (BPE_GET_ETYPE(bp) >= NUM_BP_EMBEDDED_TYPES) { errors += zfs_blkptr_verify_log(spa, bp, blk_verify, "blkptr at %p has invalid ETYPE %llu", bp, (longlong_t)BPE_GET_ETYPE(bp)); } } /* * Do not verify individual DVAs if the config is not trusted. This * will be done once the zio is executed in vdev_mirror_map_alloc. */ if (!spa->spa_trust_config) return (B_TRUE); if (!config_held) spa_config_enter(spa, SCL_VDEV, bp, RW_READER); else ASSERT(spa_config_held(spa, SCL_VDEV, RW_WRITER)); /* * Pool-specific checks. * * Note: it would be nice to verify that the blk_birth and * BP_PHYSICAL_BIRTH() are not too large. However, spa_freeze() * allows the birth time of log blocks (and dmu_sync()-ed blocks * that are in the log) to be arbitrarily large. */ for (int i = 0; i < BP_GET_NDVAS(bp); i++) { uint64_t vdevid = DVA_GET_VDEV(&bp->blk_dva[i]); if (vdevid >= spa->spa_root_vdev->vdev_children) { errors += zfs_blkptr_verify_log(spa, bp, blk_verify, "blkptr at %p DVA %u has invalid VDEV %llu", bp, i, (longlong_t)vdevid); continue; } vdev_t *vd = spa->spa_root_vdev->vdev_child[vdevid]; if (vd == NULL) { errors += zfs_blkptr_verify_log(spa, bp, blk_verify, "blkptr at %p DVA %u has invalid VDEV %llu", bp, i, (longlong_t)vdevid); continue; } if (vd->vdev_ops == &vdev_hole_ops) { errors += zfs_blkptr_verify_log(spa, bp, blk_verify, "blkptr at %p DVA %u has hole VDEV %llu", bp, i, (longlong_t)vdevid); continue; } if (vd->vdev_ops == &vdev_missing_ops) { /* * "missing" vdevs are valid during import, but we * don't have their detailed info (e.g. asize), so * we can't perform any more checks on them. */ continue; } uint64_t offset = DVA_GET_OFFSET(&bp->blk_dva[i]); uint64_t asize = DVA_GET_ASIZE(&bp->blk_dva[i]); if (BP_IS_GANG(bp)) asize = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE); if (offset + asize > vd->vdev_asize) { errors += zfs_blkptr_verify_log(spa, bp, blk_verify, "blkptr at %p DVA %u has invalid OFFSET %llu", bp, i, (longlong_t)offset); } } if (errors > 0) dprintf_bp(bp, "blkptr at %p dprintf_bp():", bp); if (!config_held) spa_config_exit(spa, SCL_VDEV, bp); return (errors == 0); } boolean_t zfs_dva_valid(spa_t *spa, const dva_t *dva, const blkptr_t *bp) { uint64_t vdevid = DVA_GET_VDEV(dva); if (vdevid >= spa->spa_root_vdev->vdev_children) return (B_FALSE); vdev_t *vd = spa->spa_root_vdev->vdev_child[vdevid]; if (vd == NULL) return (B_FALSE); if (vd->vdev_ops == &vdev_hole_ops) return (B_FALSE); if (vd->vdev_ops == &vdev_missing_ops) { return (B_FALSE); } uint64_t offset = DVA_GET_OFFSET(dva); uint64_t asize = DVA_GET_ASIZE(dva); if (BP_IS_GANG(bp)) asize = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE); if (offset + asize > vd->vdev_asize) return (B_FALSE); return (B_TRUE); } zio_t * zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, abd_t *data, uint64_t size, zio_done_func_t *done, void *private, zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb) { zio_t *zio; (void) zfs_blkptr_verify(spa, bp, flags & ZIO_FLAG_CONFIG_WRITER, BLK_VERIFY_HALT); zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp, data, size, size, done, private, ZIO_TYPE_READ, priority, flags, NULL, 0, zb, ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? ZIO_DDT_CHILD_READ_PIPELINE : ZIO_READ_PIPELINE); return (zio); } zio_t * zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, abd_t *data, uint64_t lsize, uint64_t psize, const zio_prop_t *zp, zio_done_func_t *ready, zio_done_func_t *children_ready, zio_done_func_t *physdone, zio_done_func_t *done, void *private, zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb) { zio_t *zio; ASSERT(zp->zp_checksum >= ZIO_CHECKSUM_OFF && zp->zp_checksum < ZIO_CHECKSUM_FUNCTIONS && zp->zp_compress >= ZIO_COMPRESS_OFF && zp->zp_compress < ZIO_COMPRESS_FUNCTIONS && DMU_OT_IS_VALID(zp->zp_type) && zp->zp_level < 32 && zp->zp_copies > 0 && zp->zp_copies <= spa_max_replication(spa)); zio = zio_create(pio, spa, txg, bp, data, lsize, psize, done, private, ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? ZIO_DDT_CHILD_WRITE_PIPELINE : ZIO_WRITE_PIPELINE); zio->io_ready = ready; zio->io_children_ready = children_ready; zio->io_physdone = physdone; zio->io_prop = *zp; /* * Data can be NULL if we are going to call zio_write_override() to * provide the already-allocated BP. But we may need the data to * verify a dedup hit (if requested). In this case, don't try to * dedup (just take the already-allocated BP verbatim). Encrypted * dedup blocks need data as well so we also disable dedup in this * case. */ if (data == NULL && (zio->io_prop.zp_dedup_verify || zio->io_prop.zp_encrypt)) { zio->io_prop.zp_dedup = zio->io_prop.zp_dedup_verify = B_FALSE; } return (zio); } zio_t * zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, abd_t *data, uint64_t size, zio_done_func_t *done, void *private, zio_priority_t priority, enum zio_flag flags, zbookmark_phys_t *zb) { zio_t *zio; zio = zio_create(pio, spa, txg, bp, data, size, size, done, private, ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_IO_REWRITE, NULL, 0, zb, ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE); return (zio); } void zio_write_override(zio_t *zio, blkptr_t *bp, int copies, boolean_t nopwrite) { ASSERT(zio->io_type == ZIO_TYPE_WRITE); ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); ASSERT(zio->io_stage == ZIO_STAGE_OPEN); ASSERT(zio->io_txg == spa_syncing_txg(zio->io_spa)); /* * We must reset the io_prop to match the values that existed * when the bp was first written by dmu_sync() keeping in mind * that nopwrite and dedup are mutually exclusive. */ zio->io_prop.zp_dedup = nopwrite ? B_FALSE : zio->io_prop.zp_dedup; zio->io_prop.zp_nopwrite = nopwrite; zio->io_prop.zp_copies = copies; zio->io_bp_override = bp; } void zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp) { (void) zfs_blkptr_verify(spa, bp, B_FALSE, BLK_VERIFY_HALT); /* * The check for EMBEDDED is a performance optimization. We * process the free here (by ignoring it) rather than * putting it on the list and then processing it in zio_free_sync(). */ if (BP_IS_EMBEDDED(bp)) return; metaslab_check_free(spa, bp); /* * Frees that are for the currently-syncing txg, are not going to be * deferred, and which will not need to do a read (i.e. not GANG or * DEDUP), can be processed immediately. Otherwise, put them on the * in-memory list for later processing. * * Note that we only defer frees after zfs_sync_pass_deferred_free * when the log space map feature is disabled. [see relevant comment * in spa_sync_iterate_to_convergence()] */ if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp) || txg != spa->spa_syncing_txg || (spa_sync_pass(spa) >= zfs_sync_pass_deferred_free && !spa_feature_is_active(spa, SPA_FEATURE_LOG_SPACEMAP))) { bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp); } else { VERIFY3P(zio_free_sync(NULL, spa, txg, bp, 0), ==, NULL); } } /* * To improve performance, this function may return NULL if we were able * to do the free immediately. This avoids the cost of creating a zio * (and linking it to the parent, etc). */ zio_t * zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, enum zio_flag flags) { ASSERT(!BP_IS_HOLE(bp)); ASSERT(spa_syncing_txg(spa) == txg); if (BP_IS_EMBEDDED(bp)) return (NULL); metaslab_check_free(spa, bp); arc_freed(spa, bp); dsl_scan_freed(spa, bp); if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp)) { /* * GANG and DEDUP blocks can induce a read (for the gang block * header, or the DDT), so issue them asynchronously so that * this thread is not tied up. */ enum zio_stage stage = ZIO_FREE_PIPELINE | ZIO_STAGE_ISSUE_ASYNC; return (zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), BP_GET_PSIZE(bp), NULL, NULL, ZIO_TYPE_FREE, ZIO_PRIORITY_NOW, flags, NULL, 0, NULL, ZIO_STAGE_OPEN, stage)); } else { metaslab_free(spa, bp, txg, B_FALSE); return (NULL); } } zio_t * zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, zio_done_func_t *done, void *private, enum zio_flag flags) { zio_t *zio; (void) zfs_blkptr_verify(spa, bp, flags & ZIO_FLAG_CONFIG_WRITER, BLK_VERIFY_HALT); if (BP_IS_EMBEDDED(bp)) return (zio_null(pio, spa, NULL, NULL, NULL, 0)); /* * A claim is an allocation of a specific block. Claims are needed * to support immediate writes in the intent log. The issue is that * immediate writes contain committed data, but in a txg that was * *not* committed. Upon opening the pool after an unclean shutdown, * the intent log claims all blocks that contain immediate write data * so that the SPA knows they're in use. * * All claims *must* be resolved in the first txg -- before the SPA * starts allocating blocks -- so that nothing is allocated twice. * If txg == 0 we just verify that the block is claimable. */ ASSERT3U(spa->spa_uberblock.ub_rootbp.blk_birth, <, spa_min_claim_txg(spa)); ASSERT(txg == spa_min_claim_txg(spa) || txg == 0); ASSERT(!BP_GET_DEDUP(bp) || !spa_writeable(spa)); /* zdb(8) */ zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), BP_GET_PSIZE(bp), done, private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW, flags, NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE); ASSERT0(zio->io_queued_timestamp); return (zio); } zio_t * zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd, zio_done_func_t *done, void *private, enum zio_flag flags) { zio_t *zio; int c; if (vd->vdev_children == 0) { zio = zio_create(pio, spa, 0, NULL, NULL, 0, 0, done, private, ZIO_TYPE_IOCTL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL, ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE); zio->io_cmd = cmd; } else { zio = zio_null(pio, spa, NULL, NULL, NULL, flags); for (c = 0; c < vd->vdev_children; c++) zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd, done, private, flags)); } return (zio); } zio_t * zio_trim(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, zio_done_func_t *done, void *private, zio_priority_t priority, enum zio_flag flags, enum trim_flag trim_flags) { zio_t *zio; ASSERT0(vd->vdev_children); ASSERT0(P2PHASE(offset, 1ULL << vd->vdev_ashift)); ASSERT0(P2PHASE(size, 1ULL << vd->vdev_ashift)); ASSERT3U(size, !=, 0); zio = zio_create(pio, vd->vdev_spa, 0, NULL, NULL, size, size, done, private, ZIO_TYPE_TRIM, priority, flags | ZIO_FLAG_PHYSICAL, vd, offset, NULL, ZIO_STAGE_OPEN, ZIO_TRIM_PIPELINE); zio->io_trim_flags = trim_flags; return (zio); } zio_t * zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, abd_t *data, int checksum, zio_done_func_t *done, void *private, zio_priority_t priority, enum zio_flag flags, boolean_t labels) { zio_t *zio; ASSERT(vd->vdev_children == 0); ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); ASSERT3U(offset + size, <=, vd->vdev_psize); zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, size, done, private, ZIO_TYPE_READ, priority, flags | ZIO_FLAG_PHYSICAL, vd, offset, NULL, ZIO_STAGE_OPEN, ZIO_READ_PHYS_PIPELINE); zio->io_prop.zp_checksum = checksum; return (zio); } zio_t * zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, abd_t *data, int checksum, zio_done_func_t *done, void *private, zio_priority_t priority, enum zio_flag flags, boolean_t labels) { zio_t *zio; ASSERT(vd->vdev_children == 0); ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); ASSERT3U(offset + size, <=, vd->vdev_psize); zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, size, done, private, ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_PHYSICAL, vd, offset, NULL, ZIO_STAGE_OPEN, ZIO_WRITE_PHYS_PIPELINE); zio->io_prop.zp_checksum = checksum; if (zio_checksum_table[checksum].ci_flags & ZCHECKSUM_FLAG_EMBEDDED) { /* * zec checksums are necessarily destructive -- they modify * the end of the write buffer to hold the verifier/checksum. * Therefore, we must make a local copy in case the data is * being written to multiple places in parallel. */ abd_t *wbuf = abd_alloc_sametype(data, size); abd_copy(wbuf, data, size); zio_push_transform(zio, wbuf, size, size, NULL); } return (zio); } /* * Create a child I/O to do some work for us. */ zio_t * zio_vdev_child_io(zio_t *pio, blkptr_t *bp, vdev_t *vd, uint64_t offset, abd_t *data, uint64_t size, int type, zio_priority_t priority, enum zio_flag flags, zio_done_func_t *done, void *private) { enum zio_stage pipeline = ZIO_VDEV_CHILD_PIPELINE; zio_t *zio; /* * vdev child I/Os do not propagate their error to the parent. * Therefore, for correct operation the caller *must* check for * and handle the error in the child i/o's done callback. * The only exceptions are i/os that we don't care about * (OPTIONAL or REPAIR). */ ASSERT((flags & ZIO_FLAG_OPTIONAL) || (flags & ZIO_FLAG_IO_REPAIR) || done != NULL); if (type == ZIO_TYPE_READ && bp != NULL) { /* * If we have the bp, then the child should perform the * checksum and the parent need not. This pushes error * detection as close to the leaves as possible and * eliminates redundant checksums in the interior nodes. */ pipeline |= ZIO_STAGE_CHECKSUM_VERIFY; pio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; } if (vd->vdev_ops->vdev_op_leaf) { ASSERT0(vd->vdev_children); offset += VDEV_LABEL_START_SIZE; } flags |= ZIO_VDEV_CHILD_FLAGS(pio); /* * If we've decided to do a repair, the write is not speculative -- * even if the original read was. */ if (flags & ZIO_FLAG_IO_REPAIR) flags &= ~ZIO_FLAG_SPECULATIVE; /* * If we're creating a child I/O that is not associated with a * top-level vdev, then the child zio is not an allocating I/O. * If this is a retried I/O then we ignore it since we will * have already processed the original allocating I/O. */ if (flags & ZIO_FLAG_IO_ALLOCATING && (vd != vd->vdev_top || (flags & ZIO_FLAG_IO_RETRY))) { ASSERT(pio->io_metaslab_class != NULL); ASSERT(pio->io_metaslab_class->mc_alloc_throttle_enabled); ASSERT(type == ZIO_TYPE_WRITE); ASSERT(priority == ZIO_PRIORITY_ASYNC_WRITE); ASSERT(!(flags & ZIO_FLAG_IO_REPAIR)); ASSERT(!(pio->io_flags & ZIO_FLAG_IO_REWRITE) || pio->io_child_type == ZIO_CHILD_GANG); flags &= ~ZIO_FLAG_IO_ALLOCATING; } zio = zio_create(pio, pio->io_spa, pio->io_txg, bp, data, size, size, done, private, type, priority, flags, vd, offset, &pio->io_bookmark, ZIO_STAGE_VDEV_IO_START >> 1, pipeline); ASSERT3U(zio->io_child_type, ==, ZIO_CHILD_VDEV); zio->io_physdone = pio->io_physdone; if (vd->vdev_ops->vdev_op_leaf && zio->io_logical != NULL) zio->io_logical->io_phys_children++; return (zio); } zio_t * zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, abd_t *data, uint64_t size, zio_type_t type, zio_priority_t priority, enum zio_flag flags, zio_done_func_t *done, void *private) { zio_t *zio; ASSERT(vd->vdev_ops->vdev_op_leaf); zio = zio_create(NULL, vd->vdev_spa, 0, NULL, data, size, size, done, private, type, priority, flags | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY | ZIO_FLAG_DELEGATED, vd, offset, NULL, ZIO_STAGE_VDEV_IO_START >> 1, ZIO_VDEV_CHILD_PIPELINE); return (zio); } void zio_flush(zio_t *zio, vdev_t *vd) { zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE, NULL, NULL, ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY)); } void zio_shrink(zio_t *zio, uint64_t size) { ASSERT3P(zio->io_executor, ==, NULL); ASSERT3U(zio->io_orig_size, ==, zio->io_size); ASSERT3U(size, <=, zio->io_size); /* * We don't shrink for raidz because of problems with the * reconstruction when reading back less than the block size. * Note, BP_IS_RAIDZ() assumes no compression. */ ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); if (!BP_IS_RAIDZ(zio->io_bp)) { /* we are not doing a raw write */ ASSERT3U(zio->io_size, ==, zio->io_lsize); zio->io_orig_size = zio->io_size = zio->io_lsize = size; } } /* * ========================================================================== * Prepare to read and write logical blocks * ========================================================================== */ static zio_t * zio_read_bp_init(zio_t *zio) { blkptr_t *bp = zio->io_bp; uint64_t psize = BP_IS_EMBEDDED(bp) ? BPE_GET_PSIZE(bp) : BP_GET_PSIZE(bp); ASSERT3P(zio->io_bp, ==, &zio->io_bp_copy); if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF && zio->io_child_type == ZIO_CHILD_LOGICAL && !(zio->io_flags & ZIO_FLAG_RAW_COMPRESS)) { zio_push_transform(zio, abd_alloc_sametype(zio->io_abd, psize), psize, psize, zio_decompress); } if (((BP_IS_PROTECTED(bp) && !(zio->io_flags & ZIO_FLAG_RAW_ENCRYPT)) || BP_HAS_INDIRECT_MAC_CKSUM(bp)) && zio->io_child_type == ZIO_CHILD_LOGICAL) { zio_push_transform(zio, abd_alloc_sametype(zio->io_abd, psize), psize, psize, zio_decrypt); } if (BP_IS_EMBEDDED(bp) && BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA) { int psize = BPE_GET_PSIZE(bp); void *data = abd_borrow_buf(zio->io_abd, psize); zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; decode_embedded_bp_compressed(bp, data); abd_return_buf_copy(zio->io_abd, data, psize); } else { ASSERT(!BP_IS_EMBEDDED(bp)); ASSERT3P(zio->io_bp, ==, &zio->io_bp_copy); } if (!DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) && BP_GET_LEVEL(bp) == 0) zio->io_flags |= ZIO_FLAG_DONT_CACHE; if (BP_GET_TYPE(bp) == DMU_OT_DDT_ZAP) zio->io_flags |= ZIO_FLAG_DONT_CACHE; if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL) zio->io_pipeline = ZIO_DDT_READ_PIPELINE; return (zio); } static zio_t * zio_write_bp_init(zio_t *zio) { if (!IO_IS_ALLOCATING(zio)) return (zio); ASSERT(zio->io_child_type != ZIO_CHILD_DDT); if (zio->io_bp_override) { blkptr_t *bp = zio->io_bp; zio_prop_t *zp = &zio->io_prop; ASSERT(bp->blk_birth != zio->io_txg); ASSERT(BP_GET_DEDUP(zio->io_bp_override) == 0); *bp = *zio->io_bp_override; zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; if (BP_IS_EMBEDDED(bp)) return (zio); /* * If we've been overridden and nopwrite is set then * set the flag accordingly to indicate that a nopwrite * has already occurred. */ if (!BP_IS_HOLE(bp) && zp->zp_nopwrite) { ASSERT(!zp->zp_dedup); ASSERT3U(BP_GET_CHECKSUM(bp), ==, zp->zp_checksum); zio->io_flags |= ZIO_FLAG_NOPWRITE; return (zio); } ASSERT(!zp->zp_nopwrite); if (BP_IS_HOLE(bp) || !zp->zp_dedup) return (zio); ASSERT((zio_checksum_table[zp->zp_checksum].ci_flags & ZCHECKSUM_FLAG_DEDUP) || zp->zp_dedup_verify); if (BP_GET_CHECKSUM(bp) == zp->zp_checksum && !zp->zp_encrypt) { BP_SET_DEDUP(bp, 1); zio->io_pipeline |= ZIO_STAGE_DDT_WRITE; return (zio); } /* * We were unable to handle this as an override bp, treat * it as a regular write I/O. */ zio->io_bp_override = NULL; *bp = zio->io_bp_orig; zio->io_pipeline = zio->io_orig_pipeline; } return (zio); } static zio_t * zio_write_compress(zio_t *zio) { spa_t *spa = zio->io_spa; zio_prop_t *zp = &zio->io_prop; enum zio_compress compress = zp->zp_compress; blkptr_t *bp = zio->io_bp; uint64_t lsize = zio->io_lsize; uint64_t psize = zio->io_size; int pass = 1; /* * If our children haven't all reached the ready stage, * wait for them and then repeat this pipeline stage. */ if (zio_wait_for_children(zio, ZIO_CHILD_LOGICAL_BIT | ZIO_CHILD_GANG_BIT, ZIO_WAIT_READY)) { return (NULL); } if (!IO_IS_ALLOCATING(zio)) return (zio); if (zio->io_children_ready != NULL) { /* * Now that all our children are ready, run the callback * associated with this zio in case it wants to modify the * data to be written. */ ASSERT3U(zp->zp_level, >, 0); zio->io_children_ready(zio); } ASSERT(zio->io_child_type != ZIO_CHILD_DDT); ASSERT(zio->io_bp_override == NULL); if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg) { /* * We're rewriting an existing block, which means we're * working on behalf of spa_sync(). For spa_sync() to * converge, it must eventually be the case that we don't * have to allocate new blocks. But compression changes * the blocksize, which forces a reallocate, and makes * convergence take longer. Therefore, after the first * few passes, stop compressing to ensure convergence. */ pass = spa_sync_pass(spa); ASSERT(zio->io_txg == spa_syncing_txg(spa)); ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); ASSERT(!BP_GET_DEDUP(bp)); if (pass >= zfs_sync_pass_dont_compress) compress = ZIO_COMPRESS_OFF; /* Make sure someone doesn't change their mind on overwrites */ ASSERT(BP_IS_EMBEDDED(bp) || MIN(zp->zp_copies + BP_IS_GANG(bp), spa_max_replication(spa)) == BP_GET_NDVAS(bp)); } /* If it's a compressed write that is not raw, compress the buffer. */ if (compress != ZIO_COMPRESS_OFF && !(zio->io_flags & ZIO_FLAG_RAW_COMPRESS)) { void *cbuf = zio_buf_alloc(lsize); psize = zio_compress_data(compress, zio->io_abd, cbuf, lsize, zp->zp_complevel); if (psize == 0 || psize >= lsize) { compress = ZIO_COMPRESS_OFF; zio_buf_free(cbuf, lsize); } else if (!zp->zp_dedup && !zp->zp_encrypt && psize <= BPE_PAYLOAD_SIZE && zp->zp_level == 0 && !DMU_OT_HAS_FILL(zp->zp_type) && spa_feature_is_enabled(spa, SPA_FEATURE_EMBEDDED_DATA)) { encode_embedded_bp_compressed(bp, cbuf, compress, lsize, psize); BPE_SET_ETYPE(bp, BP_EMBEDDED_TYPE_DATA); BP_SET_TYPE(bp, zio->io_prop.zp_type); BP_SET_LEVEL(bp, zio->io_prop.zp_level); zio_buf_free(cbuf, lsize); bp->blk_birth = zio->io_txg; zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; ASSERT(spa_feature_is_active(spa, SPA_FEATURE_EMBEDDED_DATA)); return (zio); } else { /* * Round compressed size up to the minimum allocation * size of the smallest-ashift device, and zero the * tail. This ensures that the compressed size of the * BP (and thus compressratio property) are correct, * in that we charge for the padding used to fill out * the last sector. */ ASSERT3U(spa->spa_min_alloc, >=, SPA_MINBLOCKSHIFT); size_t rounded = (size_t)roundup(psize, spa->spa_min_alloc); if (rounded >= lsize) { compress = ZIO_COMPRESS_OFF; zio_buf_free(cbuf, lsize); psize = lsize; } else { abd_t *cdata = abd_get_from_buf(cbuf, lsize); abd_take_ownership_of_buf(cdata, B_TRUE); abd_zero_off(cdata, psize, rounded - psize); psize = rounded; zio_push_transform(zio, cdata, psize, lsize, NULL); } } /* * We were unable to handle this as an override bp, treat * it as a regular write I/O. */ zio->io_bp_override = NULL; *bp = zio->io_bp_orig; zio->io_pipeline = zio->io_orig_pipeline; } else if ((zio->io_flags & ZIO_FLAG_RAW_ENCRYPT) != 0 && zp->zp_type == DMU_OT_DNODE) { /* * The DMU actually relies on the zio layer's compression * to free metadnode blocks that have had all contained * dnodes freed. As a result, even when doing a raw * receive, we must check whether the block can be compressed * to a hole. */ psize = zio_compress_data(ZIO_COMPRESS_EMPTY, zio->io_abd, NULL, lsize, zp->zp_complevel); if (psize == 0 || psize >= lsize) compress = ZIO_COMPRESS_OFF; } else { ASSERT3U(psize, !=, 0); } /* * The final pass of spa_sync() must be all rewrites, but the first * few passes offer a trade-off: allocating blocks defers convergence, * but newly allocated blocks are sequential, so they can be written * to disk faster. Therefore, we allow the first few passes of * spa_sync() to allocate new blocks, but force rewrites after that. * There should only be a handful of blocks after pass 1 in any case. */ if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg && BP_GET_PSIZE(bp) == psize && pass >= zfs_sync_pass_rewrite) { VERIFY3U(psize, !=, 0); enum zio_stage gang_stages = zio->io_pipeline & ZIO_GANG_STAGES; zio->io_pipeline = ZIO_REWRITE_PIPELINE | gang_stages; zio->io_flags |= ZIO_FLAG_IO_REWRITE; } else { BP_ZERO(bp); zio->io_pipeline = ZIO_WRITE_PIPELINE; } if (psize == 0) { if (zio->io_bp_orig.blk_birth != 0 && spa_feature_is_active(spa, SPA_FEATURE_HOLE_BIRTH)) { BP_SET_LSIZE(bp, lsize); BP_SET_TYPE(bp, zp->zp_type); BP_SET_LEVEL(bp, zp->zp_level); BP_SET_BIRTH(bp, zio->io_txg, 0); } zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; } else { ASSERT(zp->zp_checksum != ZIO_CHECKSUM_GANG_HEADER); BP_SET_LSIZE(bp, lsize); BP_SET_TYPE(bp, zp->zp_type); BP_SET_LEVEL(bp, zp->zp_level); BP_SET_PSIZE(bp, psize); BP_SET_COMPRESS(bp, compress); BP_SET_CHECKSUM(bp, zp->zp_checksum); BP_SET_DEDUP(bp, zp->zp_dedup); BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER); if (zp->zp_dedup) { ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); ASSERT(!zp->zp_encrypt || DMU_OT_IS_ENCRYPTED(zp->zp_type)); zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE; } if (zp->zp_nopwrite) { ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); zio->io_pipeline |= ZIO_STAGE_NOP_WRITE; } } return (zio); } static zio_t * zio_free_bp_init(zio_t *zio) { blkptr_t *bp = zio->io_bp; if (zio->io_child_type == ZIO_CHILD_LOGICAL) { if (BP_GET_DEDUP(bp)) zio->io_pipeline = ZIO_DDT_FREE_PIPELINE; } ASSERT3P(zio->io_bp, ==, &zio->io_bp_copy); return (zio); } /* * ========================================================================== * Execute the I/O pipeline * ========================================================================== */ static void zio_taskq_dispatch(zio_t *zio, zio_taskq_type_t q, boolean_t cutinline) { spa_t *spa = zio->io_spa; zio_type_t t = zio->io_type; int flags = (cutinline ? TQ_FRONT : 0); /* * If we're a config writer or a probe, the normal issue and * interrupt threads may all be blocked waiting for the config lock. * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL. */ if (zio->io_flags & (ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_PROBE)) t = ZIO_TYPE_NULL; /* * A similar issue exists for the L2ARC write thread until L2ARC 2.0. */ if (t == ZIO_TYPE_WRITE && zio->io_vd && zio->io_vd->vdev_aux) t = ZIO_TYPE_NULL; /* * If this is a high priority I/O, then use the high priority taskq if * available. */ if ((zio->io_priority == ZIO_PRIORITY_NOW || zio->io_priority == ZIO_PRIORITY_SYNC_WRITE) && spa->spa_zio_taskq[t][q + 1].stqs_count != 0) q++; ASSERT3U(q, <, ZIO_TASKQ_TYPES); /* * NB: We are assuming that the zio can only be dispatched * to a single taskq at a time. It would be a grievous error * to dispatch the zio to another taskq at the same time. */ ASSERT(taskq_empty_ent(&zio->io_tqent)); spa_taskq_dispatch_ent(spa, t, q, (task_func_t *)zio_execute, zio, flags, &zio->io_tqent); } static boolean_t zio_taskq_member(zio_t *zio, zio_taskq_type_t q) { spa_t *spa = zio->io_spa; taskq_t *tq = taskq_of_curthread(); for (zio_type_t t = 0; t < ZIO_TYPES; t++) { spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q]; uint_t i; for (i = 0; i < tqs->stqs_count; i++) { if (tqs->stqs_taskq[i] == tq) return (B_TRUE); } } return (B_FALSE); } static zio_t * zio_issue_async(zio_t *zio) { zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); return (NULL); } void zio_interrupt(zio_t *zio) { zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE); } void zio_delay_interrupt(zio_t *zio) { /* * The timeout_generic() function isn't defined in userspace, so * rather than trying to implement the function, the zio delay * functionality has been disabled for userspace builds. */ #ifdef _KERNEL /* * If io_target_timestamp is zero, then no delay has been registered * for this IO, thus jump to the end of this function and "skip" the * delay; issuing it directly to the zio layer. */ if (zio->io_target_timestamp != 0) { hrtime_t now = gethrtime(); if (now >= zio->io_target_timestamp) { /* * This IO has already taken longer than the target * delay to complete, so we don't want to delay it * any longer; we "miss" the delay and issue it * directly to the zio layer. This is likely due to * the target latency being set to a value less than * the underlying hardware can satisfy (e.g. delay * set to 1ms, but the disks take 10ms to complete an * IO request). */ DTRACE_PROBE2(zio__delay__miss, zio_t *, zio, hrtime_t, now); zio_interrupt(zio); } else { taskqid_t tid; hrtime_t diff = zio->io_target_timestamp - now; clock_t expire_at_tick = ddi_get_lbolt() + NSEC_TO_TICK(diff); DTRACE_PROBE3(zio__delay__hit, zio_t *, zio, hrtime_t, now, hrtime_t, diff); if (NSEC_TO_TICK(diff) == 0) { /* Our delay is less than a jiffy - just spin */ zfs_sleep_until(zio->io_target_timestamp); zio_interrupt(zio); } else { /* * Use taskq_dispatch_delay() in the place of * OpenZFS's timeout_generic(). */ tid = taskq_dispatch_delay(system_taskq, (task_func_t *)zio_interrupt, zio, TQ_NOSLEEP, expire_at_tick); if (tid == TASKQID_INVALID) { /* * Couldn't allocate a task. Just * finish the zio without a delay. */ zio_interrupt(zio); } } } return; } #endif DTRACE_PROBE1(zio__delay__skip, zio_t *, zio); zio_interrupt(zio); } static void zio_deadman_impl(zio_t *pio, int ziodepth) { zio_t *cio, *cio_next; zio_link_t *zl = NULL; vdev_t *vd = pio->io_vd; if (zio_deadman_log_all || (vd != NULL && vd->vdev_ops->vdev_op_leaf)) { vdev_queue_t *vq = vd ? &vd->vdev_queue : NULL; zbookmark_phys_t *zb = &pio->io_bookmark; uint64_t delta = gethrtime() - pio->io_timestamp; uint64_t failmode = spa_get_deadman_failmode(pio->io_spa); zfs_dbgmsg("slow zio[%d]: zio=%px timestamp=%llu " "delta=%llu queued=%llu io=%llu " "path=%s last=%llu " "type=%d priority=%d flags=0x%x " "stage=0x%x pipeline=0x%x pipeline-trace=0x%x " "objset=%llu object=%llu level=%llu blkid=%llu " "offset=%llu size=%llu error=%d", ziodepth, pio, pio->io_timestamp, delta, pio->io_delta, pio->io_delay, vd ? vd->vdev_path : "NULL", vq ? vq->vq_io_complete_ts : 0, pio->io_type, pio->io_priority, pio->io_flags, pio->io_stage, pio->io_pipeline, pio->io_pipeline_trace, zb->zb_objset, zb->zb_object, zb->zb_level, zb->zb_blkid, pio->io_offset, pio->io_size, pio->io_error); (void) zfs_ereport_post(FM_EREPORT_ZFS_DEADMAN, pio->io_spa, vd, zb, pio, 0); if (failmode == ZIO_FAILURE_MODE_CONTINUE && taskq_empty_ent(&pio->io_tqent)) { zio_interrupt(pio); } } mutex_enter(&pio->io_lock); for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) { cio_next = zio_walk_children(pio, &zl); zio_deadman_impl(cio, ziodepth + 1); } mutex_exit(&pio->io_lock); } /* * Log the critical information describing this zio and all of its children * using the zfs_dbgmsg() interface then post deadman event for the ZED. */ void zio_deadman(zio_t *pio, char *tag) { spa_t *spa = pio->io_spa; char *name = spa_name(spa); if (!zfs_deadman_enabled || spa_suspended(spa)) return; zio_deadman_impl(pio, 0); switch (spa_get_deadman_failmode(spa)) { case ZIO_FAILURE_MODE_WAIT: zfs_dbgmsg("%s waiting for hung I/O to pool '%s'", tag, name); break; case ZIO_FAILURE_MODE_CONTINUE: zfs_dbgmsg("%s restarting hung I/O for pool '%s'", tag, name); break; case ZIO_FAILURE_MODE_PANIC: fm_panic("%s determined I/O to pool '%s' is hung.", tag, name); break; } } /* * Execute the I/O pipeline until one of the following occurs: * (1) the I/O completes; (2) the pipeline stalls waiting for * dependent child I/Os; (3) the I/O issues, so we're waiting * for an I/O completion interrupt; (4) the I/O is delegated by * vdev-level caching or aggregation; (5) the I/O is deferred * due to vdev-level queueing; (6) the I/O is handed off to * another thread. In all cases, the pipeline stops whenever * there's no CPU work; it never burns a thread in cv_wait_io(). * * There's no locking on io_stage because there's no legitimate way * for multiple threads to be attempting to process the same I/O. */ static zio_pipe_stage_t *zio_pipeline[]; /* * zio_execute() is a wrapper around the static function * __zio_execute() so that we can force __zio_execute() to be * inlined. This reduces stack overhead which is important * because __zio_execute() is called recursively in several zio * code paths. zio_execute() itself cannot be inlined because * it is externally visible. */ void zio_execute(zio_t *zio) { fstrans_cookie_t cookie; cookie = spl_fstrans_mark(); __zio_execute(zio); spl_fstrans_unmark(cookie); } /* * Used to determine if in the current context the stack is sized large * enough to allow zio_execute() to be called recursively. A minimum * stack size of 16K is required to avoid needing to re-dispatch the zio. */ static boolean_t zio_execute_stack_check(zio_t *zio) { #if !defined(HAVE_LARGE_STACKS) dsl_pool_t *dp = spa_get_dsl(zio->io_spa); /* Executing in txg_sync_thread() context. */ if (dp && curthread == dp->dp_tx.tx_sync_thread) return (B_TRUE); /* Pool initialization outside of zio_taskq context. */ if (dp && spa_is_initializing(dp->dp_spa) && !zio_taskq_member(zio, ZIO_TASKQ_ISSUE) && !zio_taskq_member(zio, ZIO_TASKQ_ISSUE_HIGH)) return (B_TRUE); #endif /* HAVE_LARGE_STACKS */ return (B_FALSE); } __attribute__((always_inline)) static inline void __zio_execute(zio_t *zio) { ASSERT3U(zio->io_queued_timestamp, >, 0); while (zio->io_stage < ZIO_STAGE_DONE) { enum zio_stage pipeline = zio->io_pipeline; enum zio_stage stage = zio->io_stage; zio->io_executor = curthread; ASSERT(!MUTEX_HELD(&zio->io_lock)); ASSERT(ISP2(stage)); ASSERT(zio->io_stall == NULL); do { stage <<= 1; } while ((stage & pipeline) == 0); ASSERT(stage <= ZIO_STAGE_DONE); /* * If we are in interrupt context and this pipeline stage * will grab a config lock that is held across I/O, * or may wait for an I/O that needs an interrupt thread * to complete, issue async to avoid deadlock. * * For VDEV_IO_START, we cut in line so that the io will * be sent to disk promptly. */ if ((stage & ZIO_BLOCKING_STAGES) && zio->io_vd == NULL && zio_taskq_member(zio, ZIO_TASKQ_INTERRUPT)) { boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ? zio_requeue_io_start_cut_in_line : B_FALSE; zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut); return; } /* * If the current context doesn't have large enough stacks * the zio must be issued asynchronously to prevent overflow. */ if (zio_execute_stack_check(zio)) { boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ? zio_requeue_io_start_cut_in_line : B_FALSE; zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut); return; } zio->io_stage = stage; zio->io_pipeline_trace |= zio->io_stage; /* * The zio pipeline stage returns the next zio to execute * (typically the same as this one), or NULL if we should * stop. */ zio = zio_pipeline[highbit64(stage) - 1](zio); if (zio == NULL) return; } } /* * ========================================================================== * Initiate I/O, either sync or async * ========================================================================== */ int zio_wait(zio_t *zio) { /* * Some routines, like zio_free_sync(), may return a NULL zio * to avoid the performance overhead of creating and then destroying * an unneeded zio. For the callers' simplicity, we accept a NULL * zio and ignore it. */ if (zio == NULL) return (0); long timeout = MSEC_TO_TICK(zfs_deadman_ziotime_ms); int error; ASSERT3S(zio->io_stage, ==, ZIO_STAGE_OPEN); ASSERT3P(zio->io_executor, ==, NULL); zio->io_waiter = curthread; ASSERT0(zio->io_queued_timestamp); zio->io_queued_timestamp = gethrtime(); __zio_execute(zio); mutex_enter(&zio->io_lock); while (zio->io_executor != NULL) { error = cv_timedwait_io(&zio->io_cv, &zio->io_lock, ddi_get_lbolt() + timeout); if (zfs_deadman_enabled && error == -1 && gethrtime() - zio->io_queued_timestamp > spa_deadman_ziotime(zio->io_spa)) { mutex_exit(&zio->io_lock); timeout = MSEC_TO_TICK(zfs_deadman_checktime_ms); zio_deadman(zio, FTAG); mutex_enter(&zio->io_lock); } } mutex_exit(&zio->io_lock); error = zio->io_error; zio_destroy(zio); return (error); } void zio_nowait(zio_t *zio) { /* * See comment in zio_wait(). */ if (zio == NULL) return; ASSERT3P(zio->io_executor, ==, NULL); if (zio->io_child_type == ZIO_CHILD_LOGICAL && zio_unique_parent(zio) == NULL) { zio_t *pio; /* * This is a logical async I/O with no parent to wait for it. * We add it to the spa_async_root_zio "Godfather" I/O which * will ensure they complete prior to unloading the pool. */ spa_t *spa = zio->io_spa; pio = spa->spa_async_zio_root[CPU_SEQID_UNSTABLE]; zio_add_child(pio, zio); } ASSERT0(zio->io_queued_timestamp); zio->io_queued_timestamp = gethrtime(); __zio_execute(zio); } /* * ========================================================================== * Reexecute, cancel, or suspend/resume failed I/O * ========================================================================== */ static void zio_reexecute(zio_t *pio) { zio_t *cio, *cio_next; ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL); ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN); ASSERT(pio->io_gang_leader == NULL); ASSERT(pio->io_gang_tree == NULL); pio->io_flags = pio->io_orig_flags; pio->io_stage = pio->io_orig_stage; pio->io_pipeline = pio->io_orig_pipeline; pio->io_reexecute = 0; pio->io_flags |= ZIO_FLAG_REEXECUTED; pio->io_pipeline_trace = 0; pio->io_error = 0; for (int w = 0; w < ZIO_WAIT_TYPES; w++) pio->io_state[w] = 0; for (int c = 0; c < ZIO_CHILD_TYPES; c++) pio->io_child_error[c] = 0; if (IO_IS_ALLOCATING(pio)) BP_ZERO(pio->io_bp); /* * As we reexecute pio's children, new children could be created. * New children go to the head of pio's io_child_list, however, * so we will (correctly) not reexecute them. The key is that * the remainder of pio's io_child_list, from 'cio_next' onward, * cannot be affected by any side effects of reexecuting 'cio'. */ zio_link_t *zl = NULL; mutex_enter(&pio->io_lock); for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) { cio_next = zio_walk_children(pio, &zl); for (int w = 0; w < ZIO_WAIT_TYPES; w++) pio->io_children[cio->io_child_type][w]++; mutex_exit(&pio->io_lock); zio_reexecute(cio); mutex_enter(&pio->io_lock); } mutex_exit(&pio->io_lock); /* * Now that all children have been reexecuted, execute the parent. * We don't reexecute "The Godfather" I/O here as it's the * responsibility of the caller to wait on it. */ if (!(pio->io_flags & ZIO_FLAG_GODFATHER)) { pio->io_queued_timestamp = gethrtime(); __zio_execute(pio); } } void zio_suspend(spa_t *spa, zio_t *zio, zio_suspend_reason_t reason) { if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC) fm_panic("Pool '%s' has encountered an uncorrectable I/O " "failure and the failure mode property for this pool " "is set to panic.", spa_name(spa)); cmn_err(CE_WARN, "Pool '%s' has encountered an uncorrectable I/O " "failure and has been suspended.\n", spa_name(spa)); (void) zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL, NULL, NULL, 0); mutex_enter(&spa->spa_suspend_lock); if (spa->spa_suspend_zio_root == NULL) spa->spa_suspend_zio_root = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_GODFATHER); spa->spa_suspended = reason; if (zio != NULL) { ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); ASSERT(zio != spa->spa_suspend_zio_root); ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); ASSERT(zio_unique_parent(zio) == NULL); ASSERT(zio->io_stage == ZIO_STAGE_DONE); zio_add_child(spa->spa_suspend_zio_root, zio); } mutex_exit(&spa->spa_suspend_lock); } int zio_resume(spa_t *spa) { zio_t *pio; /* * Reexecute all previously suspended i/o. */ mutex_enter(&spa->spa_suspend_lock); spa->spa_suspended = ZIO_SUSPEND_NONE; cv_broadcast(&spa->spa_suspend_cv); pio = spa->spa_suspend_zio_root; spa->spa_suspend_zio_root = NULL; mutex_exit(&spa->spa_suspend_lock); if (pio == NULL) return (0); zio_reexecute(pio); return (zio_wait(pio)); } void zio_resume_wait(spa_t *spa) { mutex_enter(&spa->spa_suspend_lock); while (spa_suspended(spa)) cv_wait(&spa->spa_suspend_cv, &spa->spa_suspend_lock); mutex_exit(&spa->spa_suspend_lock); } /* * ========================================================================== * Gang blocks. * * A gang block is a collection of small blocks that looks to the DMU * like one large block. When zio_dva_allocate() cannot find a block * of the requested size, due to either severe fragmentation or the pool * being nearly full, it calls zio_write_gang_block() to construct the * block from smaller fragments. * * A gang block consists of a gang header (zio_gbh_phys_t) and up to * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like * an indirect block: it's an array of block pointers. It consumes * only one sector and hence is allocatable regardless of fragmentation. * The gang header's bps point to its gang members, which hold the data. * * Gang blocks are self-checksumming, using the bp's * as the verifier to ensure uniqueness of the SHA256 checksum. * Critically, the gang block bp's blk_cksum is the checksum of the data, * not the gang header. This ensures that data block signatures (needed for * deduplication) are independent of how the block is physically stored. * * Gang blocks can be nested: a gang member may itself be a gang block. * Thus every gang block is a tree in which root and all interior nodes are * gang headers, and the leaves are normal blocks that contain user data. * The root of the gang tree is called the gang leader. * * To perform any operation (read, rewrite, free, claim) on a gang block, * zio_gang_assemble() first assembles the gang tree (minus data leaves) * in the io_gang_tree field of the original logical i/o by recursively * reading the gang leader and all gang headers below it. This yields * an in-core tree containing the contents of every gang header and the * bps for every constituent of the gang block. * * With the gang tree now assembled, zio_gang_issue() just walks the gang tree * and invokes a callback on each bp. To free a gang block, zio_gang_issue() * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp. * zio_claim_gang() provides a similarly trivial wrapper for zio_claim(). * zio_read_gang() is a wrapper around zio_read() that omits reading gang * headers, since we already have those in io_gang_tree. zio_rewrite_gang() * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite() * of the gang header plus zio_checksum_compute() of the data to update the * gang header's blk_cksum as described above. * * The two-phase assemble/issue model solves the problem of partial failure -- * what if you'd freed part of a gang block but then couldn't read the * gang header for another part? Assembling the entire gang tree first * ensures that all the necessary gang header I/O has succeeded before * starting the actual work of free, claim, or write. Once the gang tree * is assembled, free and claim are in-memory operations that cannot fail. * * In the event that a gang write fails, zio_dva_unallocate() walks the * gang tree to immediately free (i.e. insert back into the space map) * everything we've allocated. This ensures that we don't get ENOSPC * errors during repeated suspend/resume cycles due to a flaky device. * * Gang rewrites only happen during sync-to-convergence. If we can't assemble * the gang tree, we won't modify the block, so we can safely defer the free * (knowing that the block is still intact). If we *can* assemble the gang * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free * each constituent bp and we can allocate a new block on the next sync pass. * * In all cases, the gang tree allows complete recovery from partial failure. * ========================================================================== */ static void zio_gang_issue_func_done(zio_t *zio) { - abd_put(zio->io_abd); + abd_free(zio->io_abd); } static zio_t * zio_read_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data, uint64_t offset) { if (gn != NULL) return (pio); return (zio_read(pio, pio->io_spa, bp, abd_get_offset(data, offset), BP_GET_PSIZE(bp), zio_gang_issue_func_done, NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark)); } static zio_t * zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data, uint64_t offset) { zio_t *zio; if (gn != NULL) { abd_t *gbh_abd = abd_get_from_buf(gn->gn_gbh, SPA_GANGBLOCKSIZE); zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, gbh_abd, SPA_GANGBLOCKSIZE, zio_gang_issue_func_done, NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); /* * As we rewrite each gang header, the pipeline will compute * a new gang block header checksum for it; but no one will * compute a new data checksum, so we do that here. The one * exception is the gang leader: the pipeline already computed * its data checksum because that stage precedes gang assembly. * (Presently, nothing actually uses interior data checksums; * this is just good hygiene.) */ if (gn != pio->io_gang_leader->io_gang_tree) { abd_t *buf = abd_get_offset(data, offset); zio_checksum_compute(zio, BP_GET_CHECKSUM(bp), buf, BP_GET_PSIZE(bp)); - abd_put(buf); + abd_free(buf); } /* * If we are here to damage data for testing purposes, * leave the GBH alone so that we can detect the damage. */ if (pio->io_gang_leader->io_flags & ZIO_FLAG_INDUCE_DAMAGE) zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; } else { zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, abd_get_offset(data, offset), BP_GET_PSIZE(bp), zio_gang_issue_func_done, NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); } return (zio); } /* ARGSUSED */ static zio_t * zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data, uint64_t offset) { zio_t *zio = zio_free_sync(pio, pio->io_spa, pio->io_txg, bp, ZIO_GANG_CHILD_FLAGS(pio)); if (zio == NULL) { zio = zio_null(pio, pio->io_spa, NULL, NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio)); } return (zio); } /* ARGSUSED */ static zio_t * zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data, uint64_t offset) { return (zio_claim(pio, pio->io_spa, pio->io_txg, bp, NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio))); } static zio_gang_issue_func_t *zio_gang_issue_func[ZIO_TYPES] = { NULL, zio_read_gang, zio_rewrite_gang, zio_free_gang, zio_claim_gang, NULL }; static void zio_gang_tree_assemble_done(zio_t *zio); static zio_gang_node_t * zio_gang_node_alloc(zio_gang_node_t **gnpp) { zio_gang_node_t *gn; ASSERT(*gnpp == NULL); gn = kmem_zalloc(sizeof (*gn), KM_SLEEP); gn->gn_gbh = zio_buf_alloc(SPA_GANGBLOCKSIZE); *gnpp = gn; return (gn); } static void zio_gang_node_free(zio_gang_node_t **gnpp) { zio_gang_node_t *gn = *gnpp; for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) ASSERT(gn->gn_child[g] == NULL); zio_buf_free(gn->gn_gbh, SPA_GANGBLOCKSIZE); kmem_free(gn, sizeof (*gn)); *gnpp = NULL; } static void zio_gang_tree_free(zio_gang_node_t **gnpp) { zio_gang_node_t *gn = *gnpp; if (gn == NULL) return; for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) zio_gang_tree_free(&gn->gn_child[g]); zio_gang_node_free(gnpp); } static void zio_gang_tree_assemble(zio_t *gio, blkptr_t *bp, zio_gang_node_t **gnpp) { zio_gang_node_t *gn = zio_gang_node_alloc(gnpp); abd_t *gbh_abd = abd_get_from_buf(gn->gn_gbh, SPA_GANGBLOCKSIZE); ASSERT(gio->io_gang_leader == gio); ASSERT(BP_IS_GANG(bp)); zio_nowait(zio_read(gio, gio->io_spa, bp, gbh_abd, SPA_GANGBLOCKSIZE, zio_gang_tree_assemble_done, gn, gio->io_priority, ZIO_GANG_CHILD_FLAGS(gio), &gio->io_bookmark)); } static void zio_gang_tree_assemble_done(zio_t *zio) { zio_t *gio = zio->io_gang_leader; zio_gang_node_t *gn = zio->io_private; blkptr_t *bp = zio->io_bp; ASSERT(gio == zio_unique_parent(zio)); ASSERT(zio->io_child_count == 0); if (zio->io_error) return; /* this ABD was created from a linear buf in zio_gang_tree_assemble */ if (BP_SHOULD_BYTESWAP(bp)) byteswap_uint64_array(abd_to_buf(zio->io_abd), zio->io_size); ASSERT3P(abd_to_buf(zio->io_abd), ==, gn->gn_gbh); ASSERT(zio->io_size == SPA_GANGBLOCKSIZE); ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); - abd_put(zio->io_abd); + abd_free(zio->io_abd); for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; if (!BP_IS_GANG(gbp)) continue; zio_gang_tree_assemble(gio, gbp, &gn->gn_child[g]); } } static void zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, abd_t *data, uint64_t offset) { zio_t *gio = pio->io_gang_leader; zio_t *zio; ASSERT(BP_IS_GANG(bp) == !!gn); ASSERT(BP_GET_CHECKSUM(bp) == BP_GET_CHECKSUM(gio->io_bp)); ASSERT(BP_GET_LSIZE(bp) == BP_GET_PSIZE(bp) || gn == gio->io_gang_tree); /* * If you're a gang header, your data is in gn->gn_gbh. * If you're a gang member, your data is in 'data' and gn == NULL. */ zio = zio_gang_issue_func[gio->io_type](pio, bp, gn, data, offset); if (gn != NULL) { ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; if (BP_IS_HOLE(gbp)) continue; zio_gang_tree_issue(zio, gn->gn_child[g], gbp, data, offset); offset += BP_GET_PSIZE(gbp); } } if (gn == gio->io_gang_tree) ASSERT3U(gio->io_size, ==, offset); if (zio != pio) zio_nowait(zio); } static zio_t * zio_gang_assemble(zio_t *zio) { blkptr_t *bp = zio->io_bp; ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == NULL); ASSERT(zio->io_child_type > ZIO_CHILD_GANG); zio->io_gang_leader = zio; zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree); return (zio); } static zio_t * zio_gang_issue(zio_t *zio) { blkptr_t *bp = zio->io_bp; if (zio_wait_for_children(zio, ZIO_CHILD_GANG_BIT, ZIO_WAIT_DONE)) { return (NULL); } ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio); ASSERT(zio->io_child_type > ZIO_CHILD_GANG); if (zio->io_child_error[ZIO_CHILD_GANG] == 0) zio_gang_tree_issue(zio, zio->io_gang_tree, bp, zio->io_abd, 0); else zio_gang_tree_free(&zio->io_gang_tree); zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; return (zio); } static void zio_write_gang_member_ready(zio_t *zio) { zio_t *pio = zio_unique_parent(zio); dva_t *cdva = zio->io_bp->blk_dva; dva_t *pdva = pio->io_bp->blk_dva; uint64_t asize; zio_t *gio __maybe_unused = zio->io_gang_leader; if (BP_IS_HOLE(zio->io_bp)) return; ASSERT(BP_IS_HOLE(&zio->io_bp_orig)); ASSERT(zio->io_child_type == ZIO_CHILD_GANG); ASSERT3U(zio->io_prop.zp_copies, ==, gio->io_prop.zp_copies); ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp)); ASSERT3U(pio->io_prop.zp_copies, <=, BP_GET_NDVAS(pio->io_bp)); ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp)); mutex_enter(&pio->io_lock); for (int d = 0; d < BP_GET_NDVAS(zio->io_bp); d++) { ASSERT(DVA_GET_GANG(&pdva[d])); asize = DVA_GET_ASIZE(&pdva[d]); asize += DVA_GET_ASIZE(&cdva[d]); DVA_SET_ASIZE(&pdva[d], asize); } mutex_exit(&pio->io_lock); } static void zio_write_gang_done(zio_t *zio) { /* * The io_abd field will be NULL for a zio with no data. The io_flags * will initially have the ZIO_FLAG_NODATA bit flag set, but we can't * check for it here as it is cleared in zio_ready. */ if (zio->io_abd != NULL) - abd_put(zio->io_abd); + abd_free(zio->io_abd); } static zio_t * zio_write_gang_block(zio_t *pio) { spa_t *spa = pio->io_spa; metaslab_class_t *mc = spa_normal_class(spa); blkptr_t *bp = pio->io_bp; zio_t *gio = pio->io_gang_leader; zio_t *zio; zio_gang_node_t *gn, **gnpp; zio_gbh_phys_t *gbh; abd_t *gbh_abd; uint64_t txg = pio->io_txg; uint64_t resid = pio->io_size; uint64_t lsize; int copies = gio->io_prop.zp_copies; int gbh_copies; zio_prop_t zp; int error; boolean_t has_data = !(pio->io_flags & ZIO_FLAG_NODATA); /* * encrypted blocks need DVA[2] free so encrypted gang headers can't * have a third copy. */ gbh_copies = MIN(copies + 1, spa_max_replication(spa)); if (gio->io_prop.zp_encrypt && gbh_copies >= SPA_DVAS_PER_BP) gbh_copies = SPA_DVAS_PER_BP - 1; int flags = METASLAB_HINTBP_FAVOR | METASLAB_GANG_HEADER; if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) { ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); ASSERT(has_data); flags |= METASLAB_ASYNC_ALLOC; VERIFY(zfs_refcount_held(&mc->mc_allocator[pio->io_allocator]. mca_alloc_slots, pio)); /* * The logical zio has already placed a reservation for * 'copies' allocation slots but gang blocks may require * additional copies. These additional copies * (i.e. gbh_copies - copies) are guaranteed to succeed * since metaslab_class_throttle_reserve() always allows * additional reservations for gang blocks. */ VERIFY(metaslab_class_throttle_reserve(mc, gbh_copies - copies, pio->io_allocator, pio, flags)); } error = metaslab_alloc(spa, mc, SPA_GANGBLOCKSIZE, bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp, flags, &pio->io_alloc_list, pio, pio->io_allocator); if (error) { if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) { ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); ASSERT(has_data); /* * If we failed to allocate the gang block header then * we remove any additional allocation reservations that * we placed here. The original reservation will * be removed when the logical I/O goes to the ready * stage. */ metaslab_class_throttle_unreserve(mc, gbh_copies - copies, pio->io_allocator, pio); } pio->io_error = error; return (pio); } if (pio == gio) { gnpp = &gio->io_gang_tree; } else { gnpp = pio->io_private; ASSERT(pio->io_ready == zio_write_gang_member_ready); } gn = zio_gang_node_alloc(gnpp); gbh = gn->gn_gbh; bzero(gbh, SPA_GANGBLOCKSIZE); gbh_abd = abd_get_from_buf(gbh, SPA_GANGBLOCKSIZE); /* * Create the gang header. */ zio = zio_rewrite(pio, spa, txg, bp, gbh_abd, SPA_GANGBLOCKSIZE, zio_write_gang_done, NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); /* * Create and nowait the gang children. */ for (int g = 0; resid != 0; resid -= lsize, g++) { lsize = P2ROUNDUP(resid / (SPA_GBH_NBLKPTRS - g), SPA_MINBLOCKSIZE); ASSERT(lsize >= SPA_MINBLOCKSIZE && lsize <= resid); zp.zp_checksum = gio->io_prop.zp_checksum; zp.zp_compress = ZIO_COMPRESS_OFF; zp.zp_complevel = gio->io_prop.zp_complevel; zp.zp_type = DMU_OT_NONE; zp.zp_level = 0; zp.zp_copies = gio->io_prop.zp_copies; zp.zp_dedup = B_FALSE; zp.zp_dedup_verify = B_FALSE; zp.zp_nopwrite = B_FALSE; zp.zp_encrypt = gio->io_prop.zp_encrypt; zp.zp_byteorder = gio->io_prop.zp_byteorder; bzero(zp.zp_salt, ZIO_DATA_SALT_LEN); bzero(zp.zp_iv, ZIO_DATA_IV_LEN); bzero(zp.zp_mac, ZIO_DATA_MAC_LEN); zio_t *cio = zio_write(zio, spa, txg, &gbh->zg_blkptr[g], has_data ? abd_get_offset(pio->io_abd, pio->io_size - resid) : NULL, lsize, lsize, &zp, zio_write_gang_member_ready, NULL, NULL, zio_write_gang_done, &gn->gn_child[g], pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) { ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); ASSERT(has_data); /* * Gang children won't throttle but we should * account for their work, so reserve an allocation * slot for them here. */ VERIFY(metaslab_class_throttle_reserve(mc, zp.zp_copies, cio->io_allocator, cio, flags)); } zio_nowait(cio); } /* * Set pio's pipeline to just wait for zio to finish. */ pio->io_pipeline = ZIO_INTERLOCK_PIPELINE; /* * We didn't allocate this bp, so make sure it doesn't get unmarked. */ pio->io_flags &= ~ZIO_FLAG_FASTWRITE; zio_nowait(zio); return (pio); } /* * The zio_nop_write stage in the pipeline determines if allocating a * new bp is necessary. The nopwrite feature can handle writes in * either syncing or open context (i.e. zil writes) and as a result is * mutually exclusive with dedup. * * By leveraging a cryptographically secure checksum, such as SHA256, we * can compare the checksums of the new data and the old to determine if * allocating a new block is required. Note that our requirements for * cryptographic strength are fairly weak: there can't be any accidental * hash collisions, but we don't need to be secure against intentional * (malicious) collisions. To trigger a nopwrite, you have to be able * to write the file to begin with, and triggering an incorrect (hash * collision) nopwrite is no worse than simply writing to the file. * That said, there are no known attacks against the checksum algorithms * used for nopwrite, assuming that the salt and the checksums * themselves remain secret. */ static zio_t * zio_nop_write(zio_t *zio) { blkptr_t *bp = zio->io_bp; blkptr_t *bp_orig = &zio->io_bp_orig; zio_prop_t *zp = &zio->io_prop; ASSERT(BP_GET_LEVEL(bp) == 0); ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); ASSERT(zp->zp_nopwrite); ASSERT(!zp->zp_dedup); ASSERT(zio->io_bp_override == NULL); ASSERT(IO_IS_ALLOCATING(zio)); /* * Check to see if the original bp and the new bp have matching * characteristics (i.e. same checksum, compression algorithms, etc). * If they don't then just continue with the pipeline which will * allocate a new bp. */ if (BP_IS_HOLE(bp_orig) || !(zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_flags & ZCHECKSUM_FLAG_NOPWRITE) || BP_IS_ENCRYPTED(bp) || BP_IS_ENCRYPTED(bp_orig) || BP_GET_CHECKSUM(bp) != BP_GET_CHECKSUM(bp_orig) || BP_GET_COMPRESS(bp) != BP_GET_COMPRESS(bp_orig) || BP_GET_DEDUP(bp) != BP_GET_DEDUP(bp_orig) || zp->zp_copies != BP_GET_NDVAS(bp_orig)) return (zio); /* * If the checksums match then reset the pipeline so that we * avoid allocating a new bp and issuing any I/O. */ if (ZIO_CHECKSUM_EQUAL(bp->blk_cksum, bp_orig->blk_cksum)) { ASSERT(zio_checksum_table[zp->zp_checksum].ci_flags & ZCHECKSUM_FLAG_NOPWRITE); ASSERT3U(BP_GET_PSIZE(bp), ==, BP_GET_PSIZE(bp_orig)); ASSERT3U(BP_GET_LSIZE(bp), ==, BP_GET_LSIZE(bp_orig)); ASSERT(zp->zp_compress != ZIO_COMPRESS_OFF); ASSERT(bcmp(&bp->blk_prop, &bp_orig->blk_prop, sizeof (uint64_t)) == 0); /* * If we're overwriting a block that is currently on an * indirect vdev, then ignore the nopwrite request and * allow a new block to be allocated on a concrete vdev. */ spa_config_enter(zio->io_spa, SCL_VDEV, FTAG, RW_READER); vdev_t *tvd = vdev_lookup_top(zio->io_spa, DVA_GET_VDEV(&bp->blk_dva[0])); if (tvd->vdev_ops == &vdev_indirect_ops) { spa_config_exit(zio->io_spa, SCL_VDEV, FTAG); return (zio); } spa_config_exit(zio->io_spa, SCL_VDEV, FTAG); *bp = *bp_orig; zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; zio->io_flags |= ZIO_FLAG_NOPWRITE; } return (zio); } /* * ========================================================================== * Dedup * ========================================================================== */ static void zio_ddt_child_read_done(zio_t *zio) { blkptr_t *bp = zio->io_bp; ddt_entry_t *dde = zio->io_private; ddt_phys_t *ddp; zio_t *pio = zio_unique_parent(zio); mutex_enter(&pio->io_lock); ddp = ddt_phys_select(dde, bp); if (zio->io_error == 0) ddt_phys_clear(ddp); /* this ddp doesn't need repair */ if (zio->io_error == 0 && dde->dde_repair_abd == NULL) dde->dde_repair_abd = zio->io_abd; else abd_free(zio->io_abd); mutex_exit(&pio->io_lock); } static zio_t * zio_ddt_read_start(zio_t *zio) { blkptr_t *bp = zio->io_bp; ASSERT(BP_GET_DEDUP(bp)); ASSERT(BP_GET_PSIZE(bp) == zio->io_size); ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); if (zio->io_child_error[ZIO_CHILD_DDT]) { ddt_t *ddt = ddt_select(zio->io_spa, bp); ddt_entry_t *dde = ddt_repair_start(ddt, bp); ddt_phys_t *ddp = dde->dde_phys; ddt_phys_t *ddp_self = ddt_phys_select(dde, bp); blkptr_t blk; ASSERT(zio->io_vsd == NULL); zio->io_vsd = dde; if (ddp_self == NULL) return (zio); for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { if (ddp->ddp_phys_birth == 0 || ddp == ddp_self) continue; ddt_bp_create(ddt->ddt_checksum, &dde->dde_key, ddp, &blk); zio_nowait(zio_read(zio, zio->io_spa, &blk, abd_alloc_for_io(zio->io_size, B_TRUE), zio->io_size, zio_ddt_child_read_done, dde, zio->io_priority, ZIO_DDT_CHILD_FLAGS(zio) | ZIO_FLAG_DONT_PROPAGATE, &zio->io_bookmark)); } return (zio); } zio_nowait(zio_read(zio, zio->io_spa, bp, zio->io_abd, zio->io_size, NULL, NULL, zio->io_priority, ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark)); return (zio); } static zio_t * zio_ddt_read_done(zio_t *zio) { blkptr_t *bp = zio->io_bp; if (zio_wait_for_children(zio, ZIO_CHILD_DDT_BIT, ZIO_WAIT_DONE)) { return (NULL); } ASSERT(BP_GET_DEDUP(bp)); ASSERT(BP_GET_PSIZE(bp) == zio->io_size); ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); if (zio->io_child_error[ZIO_CHILD_DDT]) { ddt_t *ddt = ddt_select(zio->io_spa, bp); ddt_entry_t *dde = zio->io_vsd; if (ddt == NULL) { ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE); return (zio); } if (dde == NULL) { zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1; zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); return (NULL); } if (dde->dde_repair_abd != NULL) { abd_copy(zio->io_abd, dde->dde_repair_abd, zio->io_size); zio->io_child_error[ZIO_CHILD_DDT] = 0; } ddt_repair_done(ddt, dde); zio->io_vsd = NULL; } ASSERT(zio->io_vsd == NULL); return (zio); } static boolean_t zio_ddt_collision(zio_t *zio, ddt_t *ddt, ddt_entry_t *dde) { spa_t *spa = zio->io_spa; boolean_t do_raw = !!(zio->io_flags & ZIO_FLAG_RAW); ASSERT(!(zio->io_bp_override && do_raw)); /* * Note: we compare the original data, not the transformed data, * because when zio->io_bp is an override bp, we will not have * pushed the I/O transforms. That's an important optimization * because otherwise we'd compress/encrypt all dmu_sync() data twice. * However, we should never get a raw, override zio so in these * cases we can compare the io_abd directly. This is useful because * it allows us to do dedup verification even if we don't have access * to the original data (for instance, if the encryption keys aren't * loaded). */ for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { zio_t *lio = dde->dde_lead_zio[p]; if (lio != NULL && do_raw) { return (lio->io_size != zio->io_size || abd_cmp(zio->io_abd, lio->io_abd) != 0); } else if (lio != NULL) { return (lio->io_orig_size != zio->io_orig_size || abd_cmp(zio->io_orig_abd, lio->io_orig_abd) != 0); } } for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { ddt_phys_t *ddp = &dde->dde_phys[p]; if (ddp->ddp_phys_birth != 0 && do_raw) { blkptr_t blk = *zio->io_bp; uint64_t psize; abd_t *tmpabd; int error; ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth); psize = BP_GET_PSIZE(&blk); if (psize != zio->io_size) return (B_TRUE); ddt_exit(ddt); tmpabd = abd_alloc_for_io(psize, B_TRUE); error = zio_wait(zio_read(NULL, spa, &blk, tmpabd, psize, NULL, NULL, ZIO_PRIORITY_SYNC_READ, ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_RAW, &zio->io_bookmark)); if (error == 0) { if (abd_cmp(tmpabd, zio->io_abd) != 0) error = SET_ERROR(ENOENT); } abd_free(tmpabd); ddt_enter(ddt); return (error != 0); } else if (ddp->ddp_phys_birth != 0) { arc_buf_t *abuf = NULL; arc_flags_t aflags = ARC_FLAG_WAIT; blkptr_t blk = *zio->io_bp; int error; ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth); if (BP_GET_LSIZE(&blk) != zio->io_orig_size) return (B_TRUE); ddt_exit(ddt); error = arc_read(NULL, spa, &blk, arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ, ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, &aflags, &zio->io_bookmark); if (error == 0) { if (abd_cmp_buf(zio->io_orig_abd, abuf->b_data, zio->io_orig_size) != 0) error = SET_ERROR(ENOENT); arc_buf_destroy(abuf, &abuf); } ddt_enter(ddt); return (error != 0); } } return (B_FALSE); } static void zio_ddt_child_write_ready(zio_t *zio) { int p = zio->io_prop.zp_copies; ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); ddt_entry_t *dde = zio->io_private; ddt_phys_t *ddp = &dde->dde_phys[p]; zio_t *pio; if (zio->io_error) return; ddt_enter(ddt); ASSERT(dde->dde_lead_zio[p] == zio); ddt_phys_fill(ddp, zio->io_bp); zio_link_t *zl = NULL; while ((pio = zio_walk_parents(zio, &zl)) != NULL) ddt_bp_fill(ddp, pio->io_bp, zio->io_txg); ddt_exit(ddt); } static void zio_ddt_child_write_done(zio_t *zio) { int p = zio->io_prop.zp_copies; ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); ddt_entry_t *dde = zio->io_private; ddt_phys_t *ddp = &dde->dde_phys[p]; ddt_enter(ddt); ASSERT(ddp->ddp_refcnt == 0); ASSERT(dde->dde_lead_zio[p] == zio); dde->dde_lead_zio[p] = NULL; if (zio->io_error == 0) { zio_link_t *zl = NULL; while (zio_walk_parents(zio, &zl) != NULL) ddt_phys_addref(ddp); } else { ddt_phys_clear(ddp); } ddt_exit(ddt); } static zio_t * zio_ddt_write(zio_t *zio) { spa_t *spa = zio->io_spa; blkptr_t *bp = zio->io_bp; uint64_t txg = zio->io_txg; zio_prop_t *zp = &zio->io_prop; int p = zp->zp_copies; zio_t *cio = NULL; ddt_t *ddt = ddt_select(spa, bp); ddt_entry_t *dde; ddt_phys_t *ddp; ASSERT(BP_GET_DEDUP(bp)); ASSERT(BP_GET_CHECKSUM(bp) == zp->zp_checksum); ASSERT(BP_IS_HOLE(bp) || zio->io_bp_override); ASSERT(!(zio->io_bp_override && (zio->io_flags & ZIO_FLAG_RAW))); ddt_enter(ddt); dde = ddt_lookup(ddt, bp, B_TRUE); ddp = &dde->dde_phys[p]; if (zp->zp_dedup_verify && zio_ddt_collision(zio, ddt, dde)) { /* * If we're using a weak checksum, upgrade to a strong checksum * and try again. If we're already using a strong checksum, * we can't resolve it, so just convert to an ordinary write. * (And automatically e-mail a paper to Nature?) */ if (!(zio_checksum_table[zp->zp_checksum].ci_flags & ZCHECKSUM_FLAG_DEDUP)) { zp->zp_checksum = spa_dedup_checksum(spa); zio_pop_transforms(zio); zio->io_stage = ZIO_STAGE_OPEN; BP_ZERO(bp); } else { zp->zp_dedup = B_FALSE; BP_SET_DEDUP(bp, B_FALSE); } ASSERT(!BP_GET_DEDUP(bp)); zio->io_pipeline = ZIO_WRITE_PIPELINE; ddt_exit(ddt); return (zio); } if (ddp->ddp_phys_birth != 0 || dde->dde_lead_zio[p] != NULL) { if (ddp->ddp_phys_birth != 0) ddt_bp_fill(ddp, bp, txg); if (dde->dde_lead_zio[p] != NULL) zio_add_child(zio, dde->dde_lead_zio[p]); else ddt_phys_addref(ddp); } else if (zio->io_bp_override) { ASSERT(bp->blk_birth == txg); ASSERT(BP_EQUAL(bp, zio->io_bp_override)); ddt_phys_fill(ddp, bp); ddt_phys_addref(ddp); } else { cio = zio_write(zio, spa, txg, bp, zio->io_orig_abd, zio->io_orig_size, zio->io_orig_size, zp, zio_ddt_child_write_ready, NULL, NULL, zio_ddt_child_write_done, dde, zio->io_priority, ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); zio_push_transform(cio, zio->io_abd, zio->io_size, 0, NULL); dde->dde_lead_zio[p] = cio; } ddt_exit(ddt); zio_nowait(cio); return (zio); } ddt_entry_t *freedde; /* for debugging */ static zio_t * zio_ddt_free(zio_t *zio) { spa_t *spa = zio->io_spa; blkptr_t *bp = zio->io_bp; ddt_t *ddt = ddt_select(spa, bp); ddt_entry_t *dde; ddt_phys_t *ddp; ASSERT(BP_GET_DEDUP(bp)); ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); ddt_enter(ddt); freedde = dde = ddt_lookup(ddt, bp, B_TRUE); if (dde) { ddp = ddt_phys_select(dde, bp); if (ddp) ddt_phys_decref(ddp); } ddt_exit(ddt); return (zio); } /* * ========================================================================== * Allocate and free blocks * ========================================================================== */ static zio_t * zio_io_to_allocate(spa_t *spa, int allocator) { zio_t *zio; ASSERT(MUTEX_HELD(&spa->spa_alloc_locks[allocator])); zio = avl_first(&spa->spa_alloc_trees[allocator]); if (zio == NULL) return (NULL); ASSERT(IO_IS_ALLOCATING(zio)); /* * Try to place a reservation for this zio. If we're unable to * reserve then we throttle. */ ASSERT3U(zio->io_allocator, ==, allocator); if (!metaslab_class_throttle_reserve(zio->io_metaslab_class, zio->io_prop.zp_copies, zio->io_allocator, zio, 0)) { return (NULL); } avl_remove(&spa->spa_alloc_trees[allocator], zio); ASSERT3U(zio->io_stage, <, ZIO_STAGE_DVA_ALLOCATE); return (zio); } static zio_t * zio_dva_throttle(zio_t *zio) { spa_t *spa = zio->io_spa; zio_t *nio; metaslab_class_t *mc; /* locate an appropriate allocation class */ mc = spa_preferred_class(spa, zio->io_size, zio->io_prop.zp_type, zio->io_prop.zp_level, zio->io_prop.zp_zpl_smallblk); if (zio->io_priority == ZIO_PRIORITY_SYNC_WRITE || !mc->mc_alloc_throttle_enabled || zio->io_child_type == ZIO_CHILD_GANG || zio->io_flags & ZIO_FLAG_NODATA) { return (zio); } ASSERT(zio->io_child_type > ZIO_CHILD_GANG); ASSERT3U(zio->io_queued_timestamp, >, 0); ASSERT(zio->io_stage == ZIO_STAGE_DVA_THROTTLE); zbookmark_phys_t *bm = &zio->io_bookmark; /* * We want to try to use as many allocators as possible to help improve * performance, but we also want logically adjacent IOs to be physically * adjacent to improve sequential read performance. We chunk each object * into 2^20 block regions, and then hash based on the objset, object, * level, and region to accomplish both of these goals. */ zio->io_allocator = cityhash4(bm->zb_objset, bm->zb_object, bm->zb_level, bm->zb_blkid >> 20) % spa->spa_alloc_count; mutex_enter(&spa->spa_alloc_locks[zio->io_allocator]); ASSERT(zio->io_type == ZIO_TYPE_WRITE); zio->io_metaslab_class = mc; avl_add(&spa->spa_alloc_trees[zio->io_allocator], zio); nio = zio_io_to_allocate(spa, zio->io_allocator); mutex_exit(&spa->spa_alloc_locks[zio->io_allocator]); return (nio); } static void zio_allocate_dispatch(spa_t *spa, int allocator) { zio_t *zio; mutex_enter(&spa->spa_alloc_locks[allocator]); zio = zio_io_to_allocate(spa, allocator); mutex_exit(&spa->spa_alloc_locks[allocator]); if (zio == NULL) return; ASSERT3U(zio->io_stage, ==, ZIO_STAGE_DVA_THROTTLE); ASSERT0(zio->io_error); zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_TRUE); } static zio_t * zio_dva_allocate(zio_t *zio) { spa_t *spa = zio->io_spa; metaslab_class_t *mc; blkptr_t *bp = zio->io_bp; int error; int flags = 0; if (zio->io_gang_leader == NULL) { ASSERT(zio->io_child_type > ZIO_CHILD_GANG); zio->io_gang_leader = zio; } ASSERT(BP_IS_HOLE(bp)); ASSERT0(BP_GET_NDVAS(bp)); ASSERT3U(zio->io_prop.zp_copies, >, 0); ASSERT3U(zio->io_prop.zp_copies, <=, spa_max_replication(spa)); ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp)); flags |= (zio->io_flags & ZIO_FLAG_FASTWRITE) ? METASLAB_FASTWRITE : 0; if (zio->io_flags & ZIO_FLAG_NODATA) flags |= METASLAB_DONT_THROTTLE; if (zio->io_flags & ZIO_FLAG_GANG_CHILD) flags |= METASLAB_GANG_CHILD; if (zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE) flags |= METASLAB_ASYNC_ALLOC; /* * if not already chosen, locate an appropriate allocation class */ mc = zio->io_metaslab_class; if (mc == NULL) { mc = spa_preferred_class(spa, zio->io_size, zio->io_prop.zp_type, zio->io_prop.zp_level, zio->io_prop.zp_zpl_smallblk); zio->io_metaslab_class = mc; } error = metaslab_alloc(spa, mc, zio->io_size, bp, zio->io_prop.zp_copies, zio->io_txg, NULL, flags, &zio->io_alloc_list, zio, zio->io_allocator); /* * Fallback to normal class when an alloc class is full */ if (error == ENOSPC && mc != spa_normal_class(spa)) { /* * If throttling, transfer reservation over to normal class. * The io_allocator slot can remain the same even though we * are switching classes. */ if (mc->mc_alloc_throttle_enabled && (zio->io_flags & ZIO_FLAG_IO_ALLOCATING)) { metaslab_class_throttle_unreserve(mc, zio->io_prop.zp_copies, zio->io_allocator, zio); zio->io_flags &= ~ZIO_FLAG_IO_ALLOCATING; mc = spa_normal_class(spa); VERIFY(metaslab_class_throttle_reserve(mc, zio->io_prop.zp_copies, zio->io_allocator, zio, flags | METASLAB_MUST_RESERVE)); } else { mc = spa_normal_class(spa); } zio->io_metaslab_class = mc; error = metaslab_alloc(spa, mc, zio->io_size, bp, zio->io_prop.zp_copies, zio->io_txg, NULL, flags, &zio->io_alloc_list, zio, zio->io_allocator); } if (error != 0) { zfs_dbgmsg("%s: metaslab allocation failure: zio %px, " "size %llu, error %d", spa_name(spa), zio, zio->io_size, error); if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE) return (zio_write_gang_block(zio)); zio->io_error = error; } return (zio); } static zio_t * zio_dva_free(zio_t *zio) { metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE); return (zio); } static zio_t * zio_dva_claim(zio_t *zio) { int error; error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg); if (error) zio->io_error = error; return (zio); } /* * Undo an allocation. This is used by zio_done() when an I/O fails * and we want to give back the block we just allocated. * This handles both normal blocks and gang blocks. */ static void zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp) { ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp)); ASSERT(zio->io_bp_override == NULL); if (!BP_IS_HOLE(bp)) metaslab_free(zio->io_spa, bp, bp->blk_birth, B_TRUE); if (gn != NULL) { for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { zio_dva_unallocate(zio, gn->gn_child[g], &gn->gn_gbh->zg_blkptr[g]); } } } /* * Try to allocate an intent log block. Return 0 on success, errno on failure. */ int zio_alloc_zil(spa_t *spa, objset_t *os, uint64_t txg, blkptr_t *new_bp, uint64_t size, boolean_t *slog) { int error = 1; zio_alloc_list_t io_alloc_list; ASSERT(txg > spa_syncing_txg(spa)); metaslab_trace_init(&io_alloc_list); /* * Block pointer fields are useful to metaslabs for stats and debugging. * Fill in the obvious ones before calling into metaslab_alloc(). */ BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG); BP_SET_PSIZE(new_bp, size); BP_SET_LEVEL(new_bp, 0); /* * When allocating a zil block, we don't have information about * the final destination of the block except the objset it's part * of, so we just hash the objset ID to pick the allocator to get * some parallelism. */ int flags = METASLAB_FASTWRITE | METASLAB_ZIL; int allocator = cityhash4(0, 0, 0, os->os_dsl_dataset->ds_object) % spa->spa_alloc_count; error = metaslab_alloc(spa, spa_log_class(spa), size, new_bp, 1, txg, NULL, flags, &io_alloc_list, NULL, allocator); if (error == 0) { *slog = TRUE; } else { error = metaslab_alloc(spa, spa_normal_class(spa), size, new_bp, 1, txg, NULL, flags, &io_alloc_list, NULL, allocator); if (error == 0) *slog = FALSE; } metaslab_trace_fini(&io_alloc_list); if (error == 0) { BP_SET_LSIZE(new_bp, size); BP_SET_PSIZE(new_bp, size); BP_SET_COMPRESS(new_bp, ZIO_COMPRESS_OFF); BP_SET_CHECKSUM(new_bp, spa_version(spa) >= SPA_VERSION_SLIM_ZIL ? ZIO_CHECKSUM_ZILOG2 : ZIO_CHECKSUM_ZILOG); BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG); BP_SET_LEVEL(new_bp, 0); BP_SET_DEDUP(new_bp, 0); BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER); /* * encrypted blocks will require an IV and salt. We generate * these now since we will not be rewriting the bp at * rewrite time. */ if (os->os_encrypted) { uint8_t iv[ZIO_DATA_IV_LEN]; uint8_t salt[ZIO_DATA_SALT_LEN]; BP_SET_CRYPT(new_bp, B_TRUE); VERIFY0(spa_crypt_get_salt(spa, dmu_objset_id(os), salt)); VERIFY0(zio_crypt_generate_iv(iv)); zio_crypt_encode_params_bp(new_bp, salt, iv); } } else { zfs_dbgmsg("%s: zil block allocation failure: " "size %llu, error %d", spa_name(spa), size, error); } return (error); } /* * ========================================================================== * Read and write to physical devices * ========================================================================== */ /* * Issue an I/O to the underlying vdev. Typically the issue pipeline * stops after this stage and will resume upon I/O completion. * However, there are instances where the vdev layer may need to * continue the pipeline when an I/O was not issued. Since the I/O * that was sent to the vdev layer might be different than the one * currently active in the pipeline (see vdev_queue_io()), we explicitly * force the underlying vdev layers to call either zio_execute() or * zio_interrupt() to ensure that the pipeline continues with the correct I/O. */ static zio_t * zio_vdev_io_start(zio_t *zio) { vdev_t *vd = zio->io_vd; uint64_t align; spa_t *spa = zio->io_spa; zio->io_delay = 0; ASSERT(zio->io_error == 0); ASSERT(zio->io_child_error[ZIO_CHILD_VDEV] == 0); if (vd == NULL) { if (!(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) spa_config_enter(spa, SCL_ZIO, zio, RW_READER); /* * The mirror_ops handle multiple DVAs in a single BP. */ vdev_mirror_ops.vdev_op_io_start(zio); return (NULL); } ASSERT3P(zio->io_logical, !=, zio); if (zio->io_type == ZIO_TYPE_WRITE) { ASSERT(spa->spa_trust_config); /* * Note: the code can handle other kinds of writes, * but we don't expect them. */ if (zio->io_vd->vdev_removing) { ASSERT(zio->io_flags & (ZIO_FLAG_PHYSICAL | ZIO_FLAG_SELF_HEAL | ZIO_FLAG_RESILVER | ZIO_FLAG_INDUCE_DAMAGE)); } } align = 1ULL << vd->vdev_top->vdev_ashift; if (!(zio->io_flags & ZIO_FLAG_PHYSICAL) && P2PHASE(zio->io_size, align) != 0) { /* Transform logical writes to be a full physical block size. */ uint64_t asize = P2ROUNDUP(zio->io_size, align); abd_t *abuf = abd_alloc_sametype(zio->io_abd, asize); ASSERT(vd == vd->vdev_top); if (zio->io_type == ZIO_TYPE_WRITE) { abd_copy(abuf, zio->io_abd, zio->io_size); abd_zero_off(abuf, zio->io_size, asize - zio->io_size); } zio_push_transform(zio, abuf, asize, asize, zio_subblock); } /* * If this is not a physical io, make sure that it is properly aligned * before proceeding. */ if (!(zio->io_flags & ZIO_FLAG_PHYSICAL)) { ASSERT0(P2PHASE(zio->io_offset, align)); ASSERT0(P2PHASE(zio->io_size, align)); } else { /* * For physical writes, we allow 512b aligned writes and assume * the device will perform a read-modify-write as necessary. */ ASSERT0(P2PHASE(zio->io_offset, SPA_MINBLOCKSIZE)); ASSERT0(P2PHASE(zio->io_size, SPA_MINBLOCKSIZE)); } VERIFY(zio->io_type != ZIO_TYPE_WRITE || spa_writeable(spa)); /* * If this is a repair I/O, and there's no self-healing involved -- * that is, we're just resilvering what we expect to resilver -- * then don't do the I/O unless zio's txg is actually in vd's DTL. * This prevents spurious resilvering. * * There are a few ways that we can end up creating these spurious * resilver i/os: * * 1. A resilver i/o will be issued if any DVA in the BP has a * dirty DTL. The mirror code will issue resilver writes to * each DVA, including the one(s) that are not on vdevs with dirty * DTLs. * * 2. With nested replication, which happens when we have a * "replacing" or "spare" vdev that's a child of a mirror or raidz. * For example, given mirror(replacing(A+B), C), it's likely that * only A is out of date (it's the new device). In this case, we'll * read from C, then use the data to resilver A+B -- but we don't * actually want to resilver B, just A. The top-level mirror has no * way to know this, so instead we just discard unnecessary repairs * as we work our way down the vdev tree. * * 3. ZTEST also creates mirrors of mirrors, mirrors of raidz, etc. * The same logic applies to any form of nested replication: ditto * + mirror, RAID-Z + replacing, etc. * * However, indirect vdevs point off to other vdevs which may have * DTL's, so we never bypass them. The child i/os on concrete vdevs * will be properly bypassed instead. * * Leaf DTL_PARTIAL can be empty when a legitimate write comes from * a dRAID spare vdev. For example, when a dRAID spare is first * used, its spare blocks need to be written to but the leaf vdev's * of such blocks can have empty DTL_PARTIAL. * * There seemed no clean way to allow such writes while bypassing * spurious ones. At this point, just avoid all bypassing for dRAID * for correctness. */ if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) && !(zio->io_flags & ZIO_FLAG_SELF_HEAL) && zio->io_txg != 0 && /* not a delegated i/o */ vd->vdev_ops != &vdev_indirect_ops && vd->vdev_top->vdev_ops != &vdev_draid_ops && !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) { ASSERT(zio->io_type == ZIO_TYPE_WRITE); zio_vdev_io_bypass(zio); return (zio); } /* * Select the next best leaf I/O to process. Distributed spares are * excluded since they dispatch the I/O directly to a leaf vdev after * applying the dRAID mapping. */ if (vd->vdev_ops->vdev_op_leaf && vd->vdev_ops != &vdev_draid_spare_ops && (zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE || zio->io_type == ZIO_TYPE_TRIM)) { if (zio->io_type == ZIO_TYPE_READ && vdev_cache_read(zio)) return (zio); if ((zio = vdev_queue_io(zio)) == NULL) return (NULL); if (!vdev_accessible(vd, zio)) { zio->io_error = SET_ERROR(ENXIO); zio_interrupt(zio); return (NULL); } zio->io_delay = gethrtime(); } vd->vdev_ops->vdev_op_io_start(zio); return (NULL); } static zio_t * zio_vdev_io_done(zio_t *zio) { vdev_t *vd = zio->io_vd; vdev_ops_t *ops = vd ? vd->vdev_ops : &vdev_mirror_ops; boolean_t unexpected_error = B_FALSE; if (zio_wait_for_children(zio, ZIO_CHILD_VDEV_BIT, ZIO_WAIT_DONE)) { return (NULL); } ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE || zio->io_type == ZIO_TYPE_TRIM); if (zio->io_delay) zio->io_delay = gethrtime() - zio->io_delay; if (vd != NULL && vd->vdev_ops->vdev_op_leaf && vd->vdev_ops != &vdev_draid_spare_ops) { vdev_queue_io_done(zio); if (zio->io_type == ZIO_TYPE_WRITE) vdev_cache_write(zio); if (zio_injection_enabled && zio->io_error == 0) zio->io_error = zio_handle_device_injections(vd, zio, EIO, EILSEQ); if (zio_injection_enabled && zio->io_error == 0) zio->io_error = zio_handle_label_injection(zio, EIO); if (zio->io_error && zio->io_type != ZIO_TYPE_TRIM) { if (!vdev_accessible(vd, zio)) { zio->io_error = SET_ERROR(ENXIO); } else { unexpected_error = B_TRUE; } } } ops->vdev_op_io_done(zio); if (unexpected_error) VERIFY(vdev_probe(vd, zio) == NULL); return (zio); } /* * This function is used to change the priority of an existing zio that is * currently in-flight. This is used by the arc to upgrade priority in the * event that a demand read is made for a block that is currently queued * as a scrub or async read IO. Otherwise, the high priority read request * would end up having to wait for the lower priority IO. */ void zio_change_priority(zio_t *pio, zio_priority_t priority) { zio_t *cio, *cio_next; zio_link_t *zl = NULL; ASSERT3U(priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); if (pio->io_vd != NULL && pio->io_vd->vdev_ops->vdev_op_leaf) { vdev_queue_change_io_priority(pio, priority); } else { pio->io_priority = priority; } mutex_enter(&pio->io_lock); for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) { cio_next = zio_walk_children(pio, &zl); zio_change_priority(cio, priority); } mutex_exit(&pio->io_lock); } /* * For non-raidz ZIOs, we can just copy aside the bad data read from the * disk, and use that to finish the checksum ereport later. */ static void zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr, const abd_t *good_buf) { /* no processing needed */ zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE); } /*ARGSUSED*/ void zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *ignored) { void *abd = abd_alloc_sametype(zio->io_abd, zio->io_size); abd_copy(abd, zio->io_abd, zio->io_size); zcr->zcr_cbinfo = zio->io_size; zcr->zcr_cbdata = abd; zcr->zcr_finish = zio_vsd_default_cksum_finish; zcr->zcr_free = zio_abd_free; } static zio_t * zio_vdev_io_assess(zio_t *zio) { vdev_t *vd = zio->io_vd; if (zio_wait_for_children(zio, ZIO_CHILD_VDEV_BIT, ZIO_WAIT_DONE)) { return (NULL); } if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) spa_config_exit(zio->io_spa, SCL_ZIO, zio); if (zio->io_vsd != NULL) { zio->io_vsd_ops->vsd_free(zio); zio->io_vsd = NULL; } if (zio_injection_enabled && zio->io_error == 0) zio->io_error = zio_handle_fault_injection(zio, EIO); /* * If the I/O failed, determine whether we should attempt to retry it. * * On retry, we cut in line in the issue queue, since we don't want * compression/checksumming/etc. work to prevent our (cheap) IO reissue. */ if (zio->io_error && vd == NULL && !(zio->io_flags & (ZIO_FLAG_DONT_RETRY | ZIO_FLAG_IO_RETRY))) { ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_QUEUE)); /* not a leaf */ ASSERT(!(zio->io_flags & ZIO_FLAG_IO_BYPASS)); /* not a leaf */ zio->io_error = 0; zio->io_flags |= ZIO_FLAG_IO_RETRY | ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE; zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1; zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, zio_requeue_io_start_cut_in_line); return (NULL); } /* * If we got an error on a leaf device, convert it to ENXIO * if the device is not accessible at all. */ if (zio->io_error && vd != NULL && vd->vdev_ops->vdev_op_leaf && !vdev_accessible(vd, zio)) zio->io_error = SET_ERROR(ENXIO); /* * If we can't write to an interior vdev (mirror or RAID-Z), * set vdev_cant_write so that we stop trying to allocate from it. */ if (zio->io_error == ENXIO && zio->io_type == ZIO_TYPE_WRITE && vd != NULL && !vd->vdev_ops->vdev_op_leaf) { vd->vdev_cant_write = B_TRUE; } /* * If a cache flush returns ENOTSUP or ENOTTY, we know that no future * attempts will ever succeed. In this case we set a persistent * boolean flag so that we don't bother with it in the future. */ if ((zio->io_error == ENOTSUP || zio->io_error == ENOTTY) && zio->io_type == ZIO_TYPE_IOCTL && zio->io_cmd == DKIOCFLUSHWRITECACHE && vd != NULL) vd->vdev_nowritecache = B_TRUE; if (zio->io_error) zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; if (vd != NULL && vd->vdev_ops->vdev_op_leaf && zio->io_physdone != NULL) { ASSERT(!(zio->io_flags & ZIO_FLAG_DELEGATED)); ASSERT(zio->io_child_type == ZIO_CHILD_VDEV); zio->io_physdone(zio->io_logical); } return (zio); } void zio_vdev_io_reissue(zio_t *zio) { ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); ASSERT(zio->io_error == 0); zio->io_stage >>= 1; } void zio_vdev_io_redone(zio_t *zio) { ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE); zio->io_stage >>= 1; } void zio_vdev_io_bypass(zio_t *zio) { ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); ASSERT(zio->io_error == 0); zio->io_flags |= ZIO_FLAG_IO_BYPASS; zio->io_stage = ZIO_STAGE_VDEV_IO_ASSESS >> 1; } /* * ========================================================================== * Encrypt and store encryption parameters * ========================================================================== */ /* * This function is used for ZIO_STAGE_ENCRYPT. It is responsible for * managing the storage of encryption parameters and passing them to the * lower-level encryption functions. */ static zio_t * zio_encrypt(zio_t *zio) { zio_prop_t *zp = &zio->io_prop; spa_t *spa = zio->io_spa; blkptr_t *bp = zio->io_bp; uint64_t psize = BP_GET_PSIZE(bp); uint64_t dsobj = zio->io_bookmark.zb_objset; dmu_object_type_t ot = BP_GET_TYPE(bp); void *enc_buf = NULL; abd_t *eabd = NULL; uint8_t salt[ZIO_DATA_SALT_LEN]; uint8_t iv[ZIO_DATA_IV_LEN]; uint8_t mac[ZIO_DATA_MAC_LEN]; boolean_t no_crypt = B_FALSE; /* the root zio already encrypted the data */ if (zio->io_child_type == ZIO_CHILD_GANG) return (zio); /* only ZIL blocks are re-encrypted on rewrite */ if (!IO_IS_ALLOCATING(zio) && ot != DMU_OT_INTENT_LOG) return (zio); if (!(zp->zp_encrypt || BP_IS_ENCRYPTED(bp))) { BP_SET_CRYPT(bp, B_FALSE); return (zio); } /* if we are doing raw encryption set the provided encryption params */ if (zio->io_flags & ZIO_FLAG_RAW_ENCRYPT) { ASSERT0(BP_GET_LEVEL(bp)); BP_SET_CRYPT(bp, B_TRUE); BP_SET_BYTEORDER(bp, zp->zp_byteorder); if (ot != DMU_OT_OBJSET) zio_crypt_encode_mac_bp(bp, zp->zp_mac); /* dnode blocks must be written out in the provided byteorder */ if (zp->zp_byteorder != ZFS_HOST_BYTEORDER && ot == DMU_OT_DNODE) { void *bswap_buf = zio_buf_alloc(psize); abd_t *babd = abd_get_from_buf(bswap_buf, psize); ASSERT3U(BP_GET_COMPRESS(bp), ==, ZIO_COMPRESS_OFF); abd_copy_to_buf(bswap_buf, zio->io_abd, psize); dmu_ot_byteswap[DMU_OT_BYTESWAP(ot)].ob_func(bswap_buf, psize); abd_take_ownership_of_buf(babd, B_TRUE); zio_push_transform(zio, babd, psize, psize, NULL); } if (DMU_OT_IS_ENCRYPTED(ot)) zio_crypt_encode_params_bp(bp, zp->zp_salt, zp->zp_iv); return (zio); } /* indirect blocks only maintain a cksum of the lower level MACs */ if (BP_GET_LEVEL(bp) > 0) { BP_SET_CRYPT(bp, B_TRUE); VERIFY0(zio_crypt_do_indirect_mac_checksum_abd(B_TRUE, zio->io_orig_abd, BP_GET_LSIZE(bp), BP_SHOULD_BYTESWAP(bp), mac)); zio_crypt_encode_mac_bp(bp, mac); return (zio); } /* * Objset blocks are a special case since they have 2 256-bit MACs * embedded within them. */ if (ot == DMU_OT_OBJSET) { ASSERT0(DMU_OT_IS_ENCRYPTED(ot)); ASSERT3U(BP_GET_COMPRESS(bp), ==, ZIO_COMPRESS_OFF); BP_SET_CRYPT(bp, B_TRUE); VERIFY0(spa_do_crypt_objset_mac_abd(B_TRUE, spa, dsobj, zio->io_abd, psize, BP_SHOULD_BYTESWAP(bp))); return (zio); } /* unencrypted object types are only authenticated with a MAC */ if (!DMU_OT_IS_ENCRYPTED(ot)) { BP_SET_CRYPT(bp, B_TRUE); VERIFY0(spa_do_crypt_mac_abd(B_TRUE, spa, dsobj, zio->io_abd, psize, mac)); zio_crypt_encode_mac_bp(bp, mac); return (zio); } /* * Later passes of sync-to-convergence may decide to rewrite data * in place to avoid more disk reallocations. This presents a problem * for encryption because this constitutes rewriting the new data with * the same encryption key and IV. However, this only applies to blocks * in the MOS (particularly the spacemaps) and we do not encrypt the * MOS. We assert that the zio is allocating or an intent log write * to enforce this. */ ASSERT(IO_IS_ALLOCATING(zio) || ot == DMU_OT_INTENT_LOG); ASSERT(BP_GET_LEVEL(bp) == 0 || ot == DMU_OT_INTENT_LOG); ASSERT(spa_feature_is_active(spa, SPA_FEATURE_ENCRYPTION)); ASSERT3U(psize, !=, 0); enc_buf = zio_buf_alloc(psize); eabd = abd_get_from_buf(enc_buf, psize); abd_take_ownership_of_buf(eabd, B_TRUE); /* * For an explanation of what encryption parameters are stored * where, see the block comment in zio_crypt.c. */ if (ot == DMU_OT_INTENT_LOG) { zio_crypt_decode_params_bp(bp, salt, iv); } else { BP_SET_CRYPT(bp, B_TRUE); } /* Perform the encryption. This should not fail */ VERIFY0(spa_do_crypt_abd(B_TRUE, spa, &zio->io_bookmark, BP_GET_TYPE(bp), BP_GET_DEDUP(bp), BP_SHOULD_BYTESWAP(bp), salt, iv, mac, psize, zio->io_abd, eabd, &no_crypt)); /* encode encryption metadata into the bp */ if (ot == DMU_OT_INTENT_LOG) { /* * ZIL blocks store the MAC in the embedded checksum, so the * transform must always be applied. */ zio_crypt_encode_mac_zil(enc_buf, mac); zio_push_transform(zio, eabd, psize, psize, NULL); } else { BP_SET_CRYPT(bp, B_TRUE); zio_crypt_encode_params_bp(bp, salt, iv); zio_crypt_encode_mac_bp(bp, mac); if (no_crypt) { ASSERT3U(ot, ==, DMU_OT_DNODE); abd_free(eabd); } else { zio_push_transform(zio, eabd, psize, psize, NULL); } } return (zio); } /* * ========================================================================== * Generate and verify checksums * ========================================================================== */ static zio_t * zio_checksum_generate(zio_t *zio) { blkptr_t *bp = zio->io_bp; enum zio_checksum checksum; if (bp == NULL) { /* * This is zio_write_phys(). * We're either generating a label checksum, or none at all. */ checksum = zio->io_prop.zp_checksum; if (checksum == ZIO_CHECKSUM_OFF) return (zio); ASSERT(checksum == ZIO_CHECKSUM_LABEL); } else { if (BP_IS_GANG(bp) && zio->io_child_type == ZIO_CHILD_GANG) { ASSERT(!IO_IS_ALLOCATING(zio)); checksum = ZIO_CHECKSUM_GANG_HEADER; } else { checksum = BP_GET_CHECKSUM(bp); } } zio_checksum_compute(zio, checksum, zio->io_abd, zio->io_size); return (zio); } static zio_t * zio_checksum_verify(zio_t *zio) { zio_bad_cksum_t info; blkptr_t *bp = zio->io_bp; int error; ASSERT(zio->io_vd != NULL); if (bp == NULL) { /* * This is zio_read_phys(). * We're either verifying a label checksum, or nothing at all. */ if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF) return (zio); ASSERT3U(zio->io_prop.zp_checksum, ==, ZIO_CHECKSUM_LABEL); } if ((error = zio_checksum_error(zio, &info)) != 0) { zio->io_error = error; if (error == ECKSUM && !(zio->io_flags & ZIO_FLAG_SPECULATIVE)) { int ret = zfs_ereport_start_checksum(zio->io_spa, zio->io_vd, &zio->io_bookmark, zio, zio->io_offset, zio->io_size, NULL, &info); if (ret != EALREADY) { mutex_enter(&zio->io_vd->vdev_stat_lock); zio->io_vd->vdev_stat.vs_checksum_errors++; mutex_exit(&zio->io_vd->vdev_stat_lock); } } } return (zio); } /* * Called by RAID-Z to ensure we don't compute the checksum twice. */ void zio_checksum_verified(zio_t *zio) { zio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; } /* * ========================================================================== * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other. * An error of 0 indicates success. ENXIO indicates whole-device failure, * which may be transient (e.g. unplugged) or permanent. ECKSUM and EIO * indicate errors that are specific to one I/O, and most likely permanent. * Any other error is presumed to be worse because we weren't expecting it. * ========================================================================== */ int zio_worst_error(int e1, int e2) { static int zio_error_rank[] = { 0, ENXIO, ECKSUM, EIO }; int r1, r2; for (r1 = 0; r1 < sizeof (zio_error_rank) / sizeof (int); r1++) if (e1 == zio_error_rank[r1]) break; for (r2 = 0; r2 < sizeof (zio_error_rank) / sizeof (int); r2++) if (e2 == zio_error_rank[r2]) break; return (r1 > r2 ? e1 : e2); } /* * ========================================================================== * I/O completion * ========================================================================== */ static zio_t * zio_ready(zio_t *zio) { blkptr_t *bp = zio->io_bp; zio_t *pio, *pio_next; zio_link_t *zl = NULL; if (zio_wait_for_children(zio, ZIO_CHILD_GANG_BIT | ZIO_CHILD_DDT_BIT, ZIO_WAIT_READY)) { return (NULL); } if (zio->io_ready) { ASSERT(IO_IS_ALLOCATING(zio)); ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp) || (zio->io_flags & ZIO_FLAG_NOPWRITE)); ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0); zio->io_ready(zio); } if (bp != NULL && bp != &zio->io_bp_copy) zio->io_bp_copy = *bp; if (zio->io_error != 0) { zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING) { ASSERT(IO_IS_ALLOCATING(zio)); ASSERT(zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); ASSERT(zio->io_metaslab_class != NULL); /* * We were unable to allocate anything, unreserve and * issue the next I/O to allocate. */ metaslab_class_throttle_unreserve( zio->io_metaslab_class, zio->io_prop.zp_copies, zio->io_allocator, zio); zio_allocate_dispatch(zio->io_spa, zio->io_allocator); } } mutex_enter(&zio->io_lock); zio->io_state[ZIO_WAIT_READY] = 1; pio = zio_walk_parents(zio, &zl); mutex_exit(&zio->io_lock); /* * As we notify zio's parents, new parents could be added. * New parents go to the head of zio's io_parent_list, however, * so we will (correctly) not notify them. The remainder of zio's * io_parent_list, from 'pio_next' onward, cannot change because * all parents must wait for us to be done before they can be done. */ for (; pio != NULL; pio = pio_next) { pio_next = zio_walk_parents(zio, &zl); zio_notify_parent(pio, zio, ZIO_WAIT_READY, NULL); } if (zio->io_flags & ZIO_FLAG_NODATA) { if (BP_IS_GANG(bp)) { zio->io_flags &= ~ZIO_FLAG_NODATA; } else { ASSERT((uintptr_t)zio->io_abd < SPA_MAXBLOCKSIZE); zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; } } if (zio_injection_enabled && zio->io_spa->spa_syncing_txg == zio->io_txg) zio_handle_ignored_writes(zio); return (zio); } /* * Update the allocation throttle accounting. */ static void zio_dva_throttle_done(zio_t *zio) { zio_t *lio __maybe_unused = zio->io_logical; zio_t *pio = zio_unique_parent(zio); vdev_t *vd = zio->io_vd; int flags = METASLAB_ASYNC_ALLOC; ASSERT3P(zio->io_bp, !=, NULL); ASSERT3U(zio->io_type, ==, ZIO_TYPE_WRITE); ASSERT3U(zio->io_priority, ==, ZIO_PRIORITY_ASYNC_WRITE); ASSERT3U(zio->io_child_type, ==, ZIO_CHILD_VDEV); ASSERT(vd != NULL); ASSERT3P(vd, ==, vd->vdev_top); ASSERT(zio_injection_enabled || !(zio->io_flags & ZIO_FLAG_IO_RETRY)); ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REPAIR)); ASSERT(zio->io_flags & ZIO_FLAG_IO_ALLOCATING); ASSERT(!(lio->io_flags & ZIO_FLAG_IO_REWRITE)); ASSERT(!(lio->io_orig_flags & ZIO_FLAG_NODATA)); /* * Parents of gang children can have two flavors -- ones that * allocated the gang header (will have ZIO_FLAG_IO_REWRITE set) * and ones that allocated the constituent blocks. The allocation * throttle needs to know the allocating parent zio so we must find * it here. */ if (pio->io_child_type == ZIO_CHILD_GANG) { /* * If our parent is a rewrite gang child then our grandparent * would have been the one that performed the allocation. */ if (pio->io_flags & ZIO_FLAG_IO_REWRITE) pio = zio_unique_parent(pio); flags |= METASLAB_GANG_CHILD; } ASSERT(IO_IS_ALLOCATING(pio)); ASSERT3P(zio, !=, zio->io_logical); ASSERT(zio->io_logical != NULL); ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REPAIR)); ASSERT0(zio->io_flags & ZIO_FLAG_NOPWRITE); ASSERT(zio->io_metaslab_class != NULL); mutex_enter(&pio->io_lock); metaslab_group_alloc_decrement(zio->io_spa, vd->vdev_id, pio, flags, pio->io_allocator, B_TRUE); mutex_exit(&pio->io_lock); metaslab_class_throttle_unreserve(zio->io_metaslab_class, 1, pio->io_allocator, pio); /* * Call into the pipeline to see if there is more work that * needs to be done. If there is work to be done it will be * dispatched to another taskq thread. */ zio_allocate_dispatch(zio->io_spa, pio->io_allocator); } static zio_t * zio_done(zio_t *zio) { /* * Always attempt to keep stack usage minimal here since * we can be called recursively up to 19 levels deep. */ const uint64_t psize = zio->io_size; zio_t *pio, *pio_next; zio_link_t *zl = NULL; /* * If our children haven't all completed, * wait for them and then repeat this pipeline stage. */ if (zio_wait_for_children(zio, ZIO_CHILD_ALL_BITS, ZIO_WAIT_DONE)) { return (NULL); } /* * If the allocation throttle is enabled, then update the accounting. * We only track child I/Os that are part of an allocating async * write. We must do this since the allocation is performed * by the logical I/O but the actual write is done by child I/Os. */ if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING && zio->io_child_type == ZIO_CHILD_VDEV) { ASSERT(zio->io_metaslab_class != NULL); ASSERT(zio->io_metaslab_class->mc_alloc_throttle_enabled); zio_dva_throttle_done(zio); } /* * If the allocation throttle is enabled, verify that * we have decremented the refcounts for every I/O that was throttled. */ if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING) { ASSERT(zio->io_type == ZIO_TYPE_WRITE); ASSERT(zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); ASSERT(zio->io_bp != NULL); metaslab_group_alloc_verify(zio->io_spa, zio->io_bp, zio, zio->io_allocator); VERIFY(zfs_refcount_not_held(&zio->io_metaslab_class-> mc_allocator[zio->io_allocator].mca_alloc_slots, zio)); } for (int c = 0; c < ZIO_CHILD_TYPES; c++) for (int w = 0; w < ZIO_WAIT_TYPES; w++) ASSERT(zio->io_children[c][w] == 0); if (zio->io_bp != NULL && !BP_IS_EMBEDDED(zio->io_bp)) { ASSERT(zio->io_bp->blk_pad[0] == 0); ASSERT(zio->io_bp->blk_pad[1] == 0); ASSERT(bcmp(zio->io_bp, &zio->io_bp_copy, sizeof (blkptr_t)) == 0 || (zio->io_bp == zio_unique_parent(zio)->io_bp)); if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(zio->io_bp) && zio->io_bp_override == NULL && !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) { ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp)); ASSERT(BP_COUNT_GANG(zio->io_bp) == 0 || (BP_COUNT_GANG(zio->io_bp) == BP_GET_NDVAS(zio->io_bp))); } if (zio->io_flags & ZIO_FLAG_NOPWRITE) VERIFY(BP_EQUAL(zio->io_bp, &zio->io_bp_orig)); } /* * If there were child vdev/gang/ddt errors, they apply to us now. */ zio_inherit_child_errors(zio, ZIO_CHILD_VDEV); zio_inherit_child_errors(zio, ZIO_CHILD_GANG); zio_inherit_child_errors(zio, ZIO_CHILD_DDT); /* * If the I/O on the transformed data was successful, generate any * checksum reports now while we still have the transformed data. */ if (zio->io_error == 0) { while (zio->io_cksum_report != NULL) { zio_cksum_report_t *zcr = zio->io_cksum_report; uint64_t align = zcr->zcr_align; uint64_t asize = P2ROUNDUP(psize, align); abd_t *adata = zio->io_abd; if (asize != psize) { adata = abd_alloc(asize, B_TRUE); abd_copy(adata, zio->io_abd, psize); abd_zero_off(adata, psize, asize - psize); } zio->io_cksum_report = zcr->zcr_next; zcr->zcr_next = NULL; zcr->zcr_finish(zcr, adata); zfs_ereport_free_checksum(zcr); if (asize != psize) abd_free(adata); } } zio_pop_transforms(zio); /* note: may set zio->io_error */ vdev_stat_update(zio, psize); /* * If this I/O is attached to a particular vdev is slow, exceeding * 30 seconds to complete, post an error described the I/O delay. * We ignore these errors if the device is currently unavailable. */ if (zio->io_delay >= MSEC2NSEC(zio_slow_io_ms)) { if (zio->io_vd != NULL && !vdev_is_dead(zio->io_vd)) { /* * We want to only increment our slow IO counters if * the IO is valid (i.e. not if the drive is removed). * * zfs_ereport_post() will also do these checks, but * it can also ratelimit and have other failures, so we * need to increment the slow_io counters independent * of it. */ if (zfs_ereport_is_valid(FM_EREPORT_ZFS_DELAY, zio->io_spa, zio->io_vd, zio)) { mutex_enter(&zio->io_vd->vdev_stat_lock); zio->io_vd->vdev_stat.vs_slow_ios++; mutex_exit(&zio->io_vd->vdev_stat_lock); (void) zfs_ereport_post(FM_EREPORT_ZFS_DELAY, zio->io_spa, zio->io_vd, &zio->io_bookmark, zio, 0); } } } if (zio->io_error) { /* * If this I/O is attached to a particular vdev, * generate an error message describing the I/O failure * at the block level. We ignore these errors if the * device is currently unavailable. */ if (zio->io_error != ECKSUM && zio->io_vd != NULL && !vdev_is_dead(zio->io_vd)) { int ret = zfs_ereport_post(FM_EREPORT_ZFS_IO, zio->io_spa, zio->io_vd, &zio->io_bookmark, zio, 0); if (ret != EALREADY) { mutex_enter(&zio->io_vd->vdev_stat_lock); if (zio->io_type == ZIO_TYPE_READ) zio->io_vd->vdev_stat.vs_read_errors++; else if (zio->io_type == ZIO_TYPE_WRITE) zio->io_vd->vdev_stat.vs_write_errors++; mutex_exit(&zio->io_vd->vdev_stat_lock); } } if ((zio->io_error == EIO || !(zio->io_flags & (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) && zio == zio->io_logical) { /* * For logical I/O requests, tell the SPA to log the * error and generate a logical data ereport. */ spa_log_error(zio->io_spa, &zio->io_bookmark); (void) zfs_ereport_post(FM_EREPORT_ZFS_DATA, zio->io_spa, NULL, &zio->io_bookmark, zio, 0); } } if (zio->io_error && zio == zio->io_logical) { /* * Determine whether zio should be reexecuted. This will * propagate all the way to the root via zio_notify_parent(). */ ASSERT(zio->io_vd == NULL && zio->io_bp != NULL); ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); if (IO_IS_ALLOCATING(zio) && !(zio->io_flags & ZIO_FLAG_CANFAIL)) { if (zio->io_error != ENOSPC) zio->io_reexecute |= ZIO_REEXECUTE_NOW; else zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; } if ((zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_FREE) && !(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && zio->io_error == ENXIO && spa_load_state(zio->io_spa) == SPA_LOAD_NONE && spa_get_failmode(zio->io_spa) != ZIO_FAILURE_MODE_CONTINUE) zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; if (!(zio->io_flags & ZIO_FLAG_CANFAIL) && !zio->io_reexecute) zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; /* * Here is a possibly good place to attempt to do * either combinatorial reconstruction or error correction * based on checksums. It also might be a good place * to send out preliminary ereports before we suspend * processing. */ } /* * If there were logical child errors, they apply to us now. * We defer this until now to avoid conflating logical child * errors with errors that happened to the zio itself when * updating vdev stats and reporting FMA events above. */ zio_inherit_child_errors(zio, ZIO_CHILD_LOGICAL); if ((zio->io_error || zio->io_reexecute) && IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio && !(zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE))) zio_dva_unallocate(zio, zio->io_gang_tree, zio->io_bp); zio_gang_tree_free(&zio->io_gang_tree); /* * Godfather I/Os should never suspend. */ if ((zio->io_flags & ZIO_FLAG_GODFATHER) && (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) zio->io_reexecute &= ~ZIO_REEXECUTE_SUSPEND; if (zio->io_reexecute) { /* * This is a logical I/O that wants to reexecute. * * Reexecute is top-down. When an i/o fails, if it's not * the root, it simply notifies its parent and sticks around. * The parent, seeing that it still has children in zio_done(), * does the same. This percolates all the way up to the root. * The root i/o will reexecute or suspend the entire tree. * * This approach ensures that zio_reexecute() honors * all the original i/o dependency relationships, e.g. * parents not executing until children are ready. */ ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); zio->io_gang_leader = NULL; mutex_enter(&zio->io_lock); zio->io_state[ZIO_WAIT_DONE] = 1; mutex_exit(&zio->io_lock); /* * "The Godfather" I/O monitors its children but is * not a true parent to them. It will track them through * the pipeline but severs its ties whenever they get into * trouble (e.g. suspended). This allows "The Godfather" * I/O to return status without blocking. */ zl = NULL; for (pio = zio_walk_parents(zio, &zl); pio != NULL; pio = pio_next) { zio_link_t *remove_zl = zl; pio_next = zio_walk_parents(zio, &zl); if ((pio->io_flags & ZIO_FLAG_GODFATHER) && (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) { zio_remove_child(pio, zio, remove_zl); /* * This is a rare code path, so we don't * bother with "next_to_execute". */ zio_notify_parent(pio, zio, ZIO_WAIT_DONE, NULL); } } if ((pio = zio_unique_parent(zio)) != NULL) { /* * We're not a root i/o, so there's nothing to do * but notify our parent. Don't propagate errors * upward since we haven't permanently failed yet. */ ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE; /* * This is a rare code path, so we don't bother with * "next_to_execute". */ zio_notify_parent(pio, zio, ZIO_WAIT_DONE, NULL); } else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) { /* * We'd fail again if we reexecuted now, so suspend * until conditions improve (e.g. device comes online). */ zio_suspend(zio->io_spa, zio, ZIO_SUSPEND_IOERR); } else { /* * Reexecution is potentially a huge amount of work. * Hand it off to the otherwise-unused claim taskq. */ ASSERT(taskq_empty_ent(&zio->io_tqent)); spa_taskq_dispatch_ent(zio->io_spa, ZIO_TYPE_CLAIM, ZIO_TASKQ_ISSUE, (task_func_t *)zio_reexecute, zio, 0, &zio->io_tqent); } return (NULL); } ASSERT(zio->io_child_count == 0); ASSERT(zio->io_reexecute == 0); ASSERT(zio->io_error == 0 || (zio->io_flags & ZIO_FLAG_CANFAIL)); /* * Report any checksum errors, since the I/O is complete. */ while (zio->io_cksum_report != NULL) { zio_cksum_report_t *zcr = zio->io_cksum_report; zio->io_cksum_report = zcr->zcr_next; zcr->zcr_next = NULL; zcr->zcr_finish(zcr, NULL); zfs_ereport_free_checksum(zcr); } if (zio->io_flags & ZIO_FLAG_FASTWRITE && zio->io_bp && !BP_IS_HOLE(zio->io_bp) && !BP_IS_EMBEDDED(zio->io_bp) && !(zio->io_flags & ZIO_FLAG_NOPWRITE)) { metaslab_fastwrite_unmark(zio->io_spa, zio->io_bp); } /* * It is the responsibility of the done callback to ensure that this * particular zio is no longer discoverable for adoption, and as * such, cannot acquire any new parents. */ if (zio->io_done) zio->io_done(zio); mutex_enter(&zio->io_lock); zio->io_state[ZIO_WAIT_DONE] = 1; mutex_exit(&zio->io_lock); /* * We are done executing this zio. We may want to execute a parent * next. See the comment in zio_notify_parent(). */ zio_t *next_to_execute = NULL; zl = NULL; for (pio = zio_walk_parents(zio, &zl); pio != NULL; pio = pio_next) { zio_link_t *remove_zl = zl; pio_next = zio_walk_parents(zio, &zl); zio_remove_child(pio, zio, remove_zl); zio_notify_parent(pio, zio, ZIO_WAIT_DONE, &next_to_execute); } if (zio->io_waiter != NULL) { mutex_enter(&zio->io_lock); zio->io_executor = NULL; cv_broadcast(&zio->io_cv); mutex_exit(&zio->io_lock); } else { zio_destroy(zio); } return (next_to_execute); } /* * ========================================================================== * I/O pipeline definition * ========================================================================== */ static zio_pipe_stage_t *zio_pipeline[] = { NULL, zio_read_bp_init, zio_write_bp_init, zio_free_bp_init, zio_issue_async, zio_write_compress, zio_encrypt, zio_checksum_generate, zio_nop_write, zio_ddt_read_start, zio_ddt_read_done, zio_ddt_write, zio_ddt_free, zio_gang_assemble, zio_gang_issue, zio_dva_throttle, zio_dva_allocate, zio_dva_free, zio_dva_claim, zio_ready, zio_vdev_io_start, zio_vdev_io_done, zio_vdev_io_assess, zio_checksum_verify, zio_done }; /* * Compare two zbookmark_phys_t's to see which we would reach first in a * pre-order traversal of the object tree. * * This is simple in every case aside from the meta-dnode object. For all other * objects, we traverse them in order (object 1 before object 2, and so on). * However, all of these objects are traversed while traversing object 0, since * the data it points to is the list of objects. Thus, we need to convert to a * canonical representation so we can compare meta-dnode bookmarks to * non-meta-dnode bookmarks. * * We do this by calculating "equivalents" for each field of the zbookmark. * zbookmarks outside of the meta-dnode use their own object and level, and * calculate the level 0 equivalent (the first L0 blkid that is contained in the * blocks this bookmark refers to) by multiplying their blkid by their span * (the number of L0 blocks contained within one block at their level). * zbookmarks inside the meta-dnode calculate their object equivalent * (which is L0equiv * dnodes per data block), use 0 for their L0equiv, and use * level + 1<<31 (any value larger than a level could ever be) for their level. * This causes them to always compare before a bookmark in their object * equivalent, compare appropriately to bookmarks in other objects, and to * compare appropriately to other bookmarks in the meta-dnode. */ int zbookmark_compare(uint16_t dbss1, uint8_t ibs1, uint16_t dbss2, uint8_t ibs2, const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2) { /* * These variables represent the "equivalent" values for the zbookmark, * after converting zbookmarks inside the meta dnode to their * normal-object equivalents. */ uint64_t zb1obj, zb2obj; uint64_t zb1L0, zb2L0; uint64_t zb1level, zb2level; if (zb1->zb_object == zb2->zb_object && zb1->zb_level == zb2->zb_level && zb1->zb_blkid == zb2->zb_blkid) return (0); IMPLY(zb1->zb_level > 0, ibs1 >= SPA_MINBLOCKSHIFT); IMPLY(zb2->zb_level > 0, ibs2 >= SPA_MINBLOCKSHIFT); /* * BP_SPANB calculates the span in blocks. */ zb1L0 = (zb1->zb_blkid) * BP_SPANB(ibs1, zb1->zb_level); zb2L0 = (zb2->zb_blkid) * BP_SPANB(ibs2, zb2->zb_level); if (zb1->zb_object == DMU_META_DNODE_OBJECT) { zb1obj = zb1L0 * (dbss1 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT)); zb1L0 = 0; zb1level = zb1->zb_level + COMPARE_META_LEVEL; } else { zb1obj = zb1->zb_object; zb1level = zb1->zb_level; } if (zb2->zb_object == DMU_META_DNODE_OBJECT) { zb2obj = zb2L0 * (dbss2 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT)); zb2L0 = 0; zb2level = zb2->zb_level + COMPARE_META_LEVEL; } else { zb2obj = zb2->zb_object; zb2level = zb2->zb_level; } /* Now that we have a canonical representation, do the comparison. */ if (zb1obj != zb2obj) return (zb1obj < zb2obj ? -1 : 1); else if (zb1L0 != zb2L0) return (zb1L0 < zb2L0 ? -1 : 1); else if (zb1level != zb2level) return (zb1level > zb2level ? -1 : 1); /* * This can (theoretically) happen if the bookmarks have the same object * and level, but different blkids, if the block sizes are not the same. * There is presently no way to change the indirect block sizes */ return (0); } /* * This function checks the following: given that last_block is the place that * our traversal stopped last time, does that guarantee that we've visited * every node under subtree_root? Therefore, we can't just use the raw output * of zbookmark_compare. We have to pass in a modified version of * subtree_root; by incrementing the block id, and then checking whether * last_block is before or equal to that, we can tell whether or not having * visited last_block implies that all of subtree_root's children have been * visited. */ boolean_t zbookmark_subtree_completed(const dnode_phys_t *dnp, const zbookmark_phys_t *subtree_root, const zbookmark_phys_t *last_block) { zbookmark_phys_t mod_zb = *subtree_root; mod_zb.zb_blkid++; ASSERT(last_block->zb_level == 0); /* The objset_phys_t isn't before anything. */ if (dnp == NULL) return (B_FALSE); /* * We pass in 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT) for the * data block size in sectors, because that variable is only used if * the bookmark refers to a block in the meta-dnode. Since we don't * know without examining it what object it refers to, and there's no * harm in passing in this value in other cases, we always pass it in. * * We pass in 0 for the indirect block size shift because zb2 must be * level 0. The indirect block size is only used to calculate the span * of the bookmark, but since the bookmark must be level 0, the span is * always 1, so the math works out. * * If you make changes to how the zbookmark_compare code works, be sure * to make sure that this code still works afterwards. */ return (zbookmark_compare(dnp->dn_datablkszsec, dnp->dn_indblkshift, 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT), 0, &mod_zb, last_block) <= 0); } EXPORT_SYMBOL(zio_type_name); EXPORT_SYMBOL(zio_buf_alloc); EXPORT_SYMBOL(zio_data_buf_alloc); EXPORT_SYMBOL(zio_buf_free); EXPORT_SYMBOL(zio_data_buf_free); /* BEGIN CSTYLED */ ZFS_MODULE_PARAM(zfs_zio, zio_, slow_io_ms, INT, ZMOD_RW, "Max I/O completion time (milliseconds) before marking it as slow"); ZFS_MODULE_PARAM(zfs_zio, zio_, requeue_io_start_cut_in_line, INT, ZMOD_RW, "Prioritize requeued I/O"); ZFS_MODULE_PARAM(zfs, zfs_, sync_pass_deferred_free, INT, ZMOD_RW, "Defer frees starting in this pass"); ZFS_MODULE_PARAM(zfs, zfs_, sync_pass_dont_compress, INT, ZMOD_RW, "Don't compress starting in this pass"); ZFS_MODULE_PARAM(zfs, zfs_, sync_pass_rewrite, INT, ZMOD_RW, "Rewrite new bps starting in this pass"); ZFS_MODULE_PARAM(zfs_zio, zio_, dva_throttle_enabled, INT, ZMOD_RW, "Throttle block allocations in the ZIO pipeline"); ZFS_MODULE_PARAM(zfs_zio, zio_, deadman_log_all, INT, ZMOD_RW, "Log all slow ZIOs, not just those with vdevs"); /* END CSTYLED */