Index: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_raidz.c =================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_raidz.c (revision 320184) +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_raidz.c (revision 320185) @@ -1,2597 +1,2598 @@ /* * 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, 2017 by Delphix. All rights reserved. * Copyright (c) 2013, Joyent, Inc. All rights reserved. * Copyright (c) 2014 Integros [integros.com] */ #include #include #include #ifdef illumos #include #endif #include #include #include #include #include #include #include #include /* * 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 trival * 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. */ 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_abd; /* I/O data */ void *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? */ } raidz_col_t; typedef struct raidz_map { uint64_t rm_cols; /* Regular column count */ uint64_t rm_scols; /* Count including skipped columns */ uint64_t rm_bigcols; /* Number of oversized columns */ uint64_t rm_asize; /* Actual total I/O size */ uint64_t rm_missingdata; /* Count of missing data devices */ uint64_t rm_missingparity; /* Count of missing parity devices */ uint64_t rm_firstdatacol; /* First data column/parity count */ uint64_t rm_nskip; /* Skipped sectors for padding */ uint64_t rm_skipstart; /* Column index of padding start */ abd_t *rm_abd_copy; /* rm_asize-buffer of copied data */ uintptr_t rm_reports; /* # of referencing checksum reports */ uint8_t rm_freed; /* map no longer has referencing ZIO */ uint8_t rm_ecksuminjected; /* checksum error was injected */ raidz_col_t rm_col[1]; /* Flexible array of I/O columns */ } raidz_map_t; #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) & 0x1d1d1d1d1d1d1d1d); \ } #define VDEV_RAIDZ_64MUL_4(x, mask) \ { \ VDEV_RAIDZ_64MUL_2((x), mask); \ VDEV_RAIDZ_64MUL_2((x), mask); \ } #define VDEV_LABEL_OFFSET(x) (x + VDEV_LABEL_START_SIZE) /* * Force reconstruction to use the general purpose method. */ int vdev_raidz_default_to_general; /* Powers of 2 in the Galois field defined above. */ static const uint8_t vdev_raidz_pow2[256] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1d, 0x3a, 0x74, 0xe8, 0xcd, 0x87, 0x13, 0x26, 0x4c, 0x98, 0x2d, 0x5a, 0xb4, 0x75, 0xea, 0xc9, 0x8f, 0x03, 0x06, 0x0c, 0x18, 0x30, 0x60, 0xc0, 0x9d, 0x27, 0x4e, 0x9c, 0x25, 0x4a, 0x94, 0x35, 0x6a, 0xd4, 0xb5, 0x77, 0xee, 0xc1, 0x9f, 0x23, 0x46, 0x8c, 0x05, 0x0a, 0x14, 0x28, 0x50, 0xa0, 0x5d, 0xba, 0x69, 0xd2, 0xb9, 0x6f, 0xde, 0xa1, 0x5f, 0xbe, 0x61, 0xc2, 0x99, 0x2f, 0x5e, 0xbc, 0x65, 0xca, 0x89, 0x0f, 0x1e, 0x3c, 0x78, 0xf0, 0xfd, 0xe7, 0xd3, 0xbb, 0x6b, 0xd6, 0xb1, 0x7f, 0xfe, 0xe1, 0xdf, 0xa3, 0x5b, 0xb6, 0x71, 0xe2, 0xd9, 0xaf, 0x43, 0x86, 0x11, 0x22, 0x44, 0x88, 0x0d, 0x1a, 0x34, 0x68, 0xd0, 0xbd, 0x67, 0xce, 0x81, 0x1f, 0x3e, 0x7c, 0xf8, 0xed, 0xc7, 0x93, 0x3b, 0x76, 0xec, 0xc5, 0x97, 0x33, 0x66, 0xcc, 0x85, 0x17, 0x2e, 0x5c, 0xb8, 0x6d, 0xda, 0xa9, 0x4f, 0x9e, 0x21, 0x42, 0x84, 0x15, 0x2a, 0x54, 0xa8, 0x4d, 0x9a, 0x29, 0x52, 0xa4, 0x55, 0xaa, 0x49, 0x92, 0x39, 0x72, 0xe4, 0xd5, 0xb7, 0x73, 0xe6, 0xd1, 0xbf, 0x63, 0xc6, 0x91, 0x3f, 0x7e, 0xfc, 0xe5, 0xd7, 0xb3, 0x7b, 0xf6, 0xf1, 0xff, 0xe3, 0xdb, 0xab, 0x4b, 0x96, 0x31, 0x62, 0xc4, 0x95, 0x37, 0x6e, 0xdc, 0xa5, 0x57, 0xae, 0x41, 0x82, 0x19, 0x32, 0x64, 0xc8, 0x8d, 0x07, 0x0e, 0x1c, 0x38, 0x70, 0xe0, 0xdd, 0xa7, 0x53, 0xa6, 0x51, 0xa2, 0x59, 0xb2, 0x79, 0xf2, 0xf9, 0xef, 0xc3, 0x9b, 0x2b, 0x56, 0xac, 0x45, 0x8a, 0x09, 0x12, 0x24, 0x48, 0x90, 0x3d, 0x7a, 0xf4, 0xf5, 0xf7, 0xf3, 0xfb, 0xeb, 0xcb, 0x8b, 0x0b, 0x16, 0x2c, 0x58, 0xb0, 0x7d, 0xfa, 0xe9, 0xcf, 0x83, 0x1b, 0x36, 0x6c, 0xd8, 0xad, 0x47, 0x8e, 0x01 }; /* Logs of 2 in the Galois field defined above. */ static const uint8_t vdev_raidz_log2[256] = { 0x00, 0x00, 0x01, 0x19, 0x02, 0x32, 0x1a, 0xc6, 0x03, 0xdf, 0x33, 0xee, 0x1b, 0x68, 0xc7, 0x4b, 0x04, 0x64, 0xe0, 0x0e, 0x34, 0x8d, 0xef, 0x81, 0x1c, 0xc1, 0x69, 0xf8, 0xc8, 0x08, 0x4c, 0x71, 0x05, 0x8a, 0x65, 0x2f, 0xe1, 0x24, 0x0f, 0x21, 0x35, 0x93, 0x8e, 0xda, 0xf0, 0x12, 0x82, 0x45, 0x1d, 0xb5, 0xc2, 0x7d, 0x6a, 0x27, 0xf9, 0xb9, 0xc9, 0x9a, 0x09, 0x78, 0x4d, 0xe4, 0x72, 0xa6, 0x06, 0xbf, 0x8b, 0x62, 0x66, 0xdd, 0x30, 0xfd, 0xe2, 0x98, 0x25, 0xb3, 0x10, 0x91, 0x22, 0x88, 0x36, 0xd0, 0x94, 0xce, 0x8f, 0x96, 0xdb, 0xbd, 0xf1, 0xd2, 0x13, 0x5c, 0x83, 0x38, 0x46, 0x40, 0x1e, 0x42, 0xb6, 0xa3, 0xc3, 0x48, 0x7e, 0x6e, 0x6b, 0x3a, 0x28, 0x54, 0xfa, 0x85, 0xba, 0x3d, 0xca, 0x5e, 0x9b, 0x9f, 0x0a, 0x15, 0x79, 0x2b, 0x4e, 0xd4, 0xe5, 0xac, 0x73, 0xf3, 0xa7, 0x57, 0x07, 0x70, 0xc0, 0xf7, 0x8c, 0x80, 0x63, 0x0d, 0x67, 0x4a, 0xde, 0xed, 0x31, 0xc5, 0xfe, 0x18, 0xe3, 0xa5, 0x99, 0x77, 0x26, 0xb8, 0xb4, 0x7c, 0x11, 0x44, 0x92, 0xd9, 0x23, 0x20, 0x89, 0x2e, 0x37, 0x3f, 0xd1, 0x5b, 0x95, 0xbc, 0xcf, 0xcd, 0x90, 0x87, 0x97, 0xb2, 0xdc, 0xfc, 0xbe, 0x61, 0xf2, 0x56, 0xd3, 0xab, 0x14, 0x2a, 0x5d, 0x9e, 0x84, 0x3c, 0x39, 0x53, 0x47, 0x6d, 0x41, 0xa2, 0x1f, 0x2d, 0x43, 0xd8, 0xb7, 0x7b, 0xa4, 0x76, 0xc4, 0x17, 0x49, 0xec, 0x7f, 0x0c, 0x6f, 0xf6, 0x6c, 0xa1, 0x3b, 0x52, 0x29, 0x9d, 0x55, 0xaa, 0xfb, 0x60, 0x86, 0xb1, 0xbb, 0xcc, 0x3e, 0x5a, 0xcb, 0x59, 0x5f, 0xb0, 0x9c, 0xa9, 0xa0, 0x51, 0x0b, 0xf5, 0x16, 0xeb, 0x7a, 0x75, 0x2c, 0xd7, 0x4f, 0xae, 0xd5, 0xe9, 0xe6, 0xe7, 0xad, 0xe8, 0x74, 0xd6, 0xf4, 0xea, 0xa8, 0x50, 0x58, 0xaf, }; static void vdev_raidz_generate_parity(raidz_map_t *rm); /* * Multiply a given number by 2 raised to the given power. */ static uint8_t vdev_raidz_exp2(uint_t a, int exp) { if (a == 0) return (0); ASSERT(exp >= 0); ASSERT(vdev_raidz_log2[a] > 0 || a == 1); exp += vdev_raidz_log2[a]; if (exp > 255) exp -= 255; return (vdev_raidz_pow2[exp]); } static void vdev_raidz_map_free(raidz_map_t *rm) { int c; size_t size; for (c = 0; c < rm->rm_firstdatacol; c++) { if (rm->rm_col[c].rc_abd != NULL) abd_free(rm->rm_col[c].rc_abd); if (rm->rm_col[c].rc_gdata != NULL) zio_buf_free(rm->rm_col[c].rc_gdata, rm->rm_col[c].rc_size); } size = 0; for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) { - abd_put(rm->rm_col[c].rc_abd); + if (rm->rm_col[c].rc_abd != NULL) + abd_put(rm->rm_col[c].rc_abd); size += rm->rm_col[c].rc_size; } if (rm->rm_abd_copy != NULL) abd_free(rm->rm_abd_copy); kmem_free(rm, offsetof(raidz_map_t, rm_col[rm->rm_scols])); } static void vdev_raidz_map_free_vsd(zio_t *zio) { raidz_map_t *rm = zio->io_vsd; ASSERT0(rm->rm_freed); rm->rm_freed = 1; 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 != 0) vdev_raidz_map_free(rm); } static void vdev_raidz_cksum_finish(zio_cksum_report_t *zcr, const void *good_data) { raidz_map_t *rm = zcr->zcr_cbdata; size_t c = zcr->zcr_cbinfo; size_t x; const char *good = NULL; char *bad; if (good_data == NULL) { zfs_ereport_finish_checksum(zcr, NULL, NULL, B_FALSE); return; } if (c < rm->rm_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 (rm->rm_col[0].rc_gdata == NULL) { abd_t *bad_parity[VDEV_RAIDZ_MAXPARITY]; char *buf; int offset; /* * Set up the rm_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 < rm->rm_firstdatacol; x++) { bad_parity[x] = rm->rm_col[x].rc_abd; rm->rm_col[x].rc_gdata = zio_buf_alloc(rm->rm_col[x].rc_size); rm->rm_col[x].rc_abd = abd_get_from_buf(rm->rm_col[x].rc_gdata, rm->rm_col[x].rc_size); } /* fill in the data columns from good_data */ buf = (char *)good_data; for (; x < rm->rm_cols; x++) { abd_put(rm->rm_col[x].rc_abd); rm->rm_col[x].rc_abd = abd_get_from_buf(buf, rm->rm_col[x].rc_size); buf += rm->rm_col[x].rc_size; } /* * Construct the parity from the good data. */ vdev_raidz_generate_parity(rm); /* restore everything back to its original state */ for (x = 0; x < rm->rm_firstdatacol; x++) { abd_put(rm->rm_col[x].rc_abd); rm->rm_col[x].rc_abd = bad_parity[x]; } offset = 0; for (x = rm->rm_firstdatacol; x < rm->rm_cols; x++) { abd_put(rm->rm_col[x].rc_abd); rm->rm_col[x].rc_abd = abd_get_offset( rm->rm_abd_copy, offset); offset += rm->rm_col[x].rc_size; } } ASSERT3P(rm->rm_col[c].rc_gdata, !=, NULL); good = rm->rm_col[c].rc_gdata; } else { /* adjust good_data to point at the start of our column */ good = good_data; for (x = rm->rm_firstdatacol; x < c; x++) good += rm->rm_col[x].rc_size; } bad = abd_borrow_buf_copy(rm->rm_col[c].rc_abd, rm->rm_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_return_buf(rm->rm_col[c].rc_abd, bad, rm->rm_col[c].rc_size); } /* * 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; size_t offset; raidz_map_t *rm = zio->io_vsd; size_t size; /* 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); if (rm->rm_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. */ size = 0; for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) size += rm->rm_col[c].rc_size; rm->rm_abd_copy = abd_alloc_sametype(rm->rm_col[rm->rm_firstdatacol].rc_abd, size); for (offset = 0, c = rm->rm_firstdatacol; c < rm->rm_cols; c++) { raidz_col_t *col = &rm->rm_col[c]; abd_t *tmp = abd_get_offset(rm->rm_abd_copy, offset); abd_copy(tmp, col->rc_abd, col->rc_size); abd_put(col->rc_abd); col->rc_abd = tmp; offset += col->rc_size; } ASSERT3U(offset, ==, size); } static const zio_vsd_ops_t vdev_raidz_vsd_ops = { vdev_raidz_map_free_vsd, vdev_raidz_cksum_report }; /* * Divides the IO evenly across all child vdevs; usually, dcols is * the number of children in the target vdev. */ static raidz_map_t * vdev_raidz_map_alloc(abd_t *abd, uint64_t size, uint64_t offset, boolean_t dofree, uint64_t unit_shift, uint64_t dcols, uint64_t nparity) { raidz_map_t *rm; /* The starting RAIDZ (parent) vdev sector of the block. */ uint64_t b = offset >> unit_shift; /* The zio's size in units of the vdev's minimum sector size. */ uint64_t s = size >> unit_shift; /* The first column for this stripe. */ uint64_t f = b % dcols; /* The starting byte offset on each child vdev. */ uint64_t o = (b / dcols) << unit_shift; uint64_t q, r, c, bc, col, acols, scols, coff, devidx, asize, tot; uint64_t off = 0; /* * "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); rm = kmem_alloc(offsetof(raidz_map_t, rm_col[scols]), KM_SLEEP); rm->rm_cols = acols; rm->rm_scols = scols; rm->rm_bigcols = bc; rm->rm_skipstart = bc; rm->rm_missingdata = 0; rm->rm_missingparity = 0; rm->rm_firstdatacol = nparity; rm->rm_abd_copy = NULL; rm->rm_reports = 0; rm->rm_freed = 0; rm->rm_ecksuminjected = 0; asize = 0; for (c = 0; c < scols; c++) { col = f + c; coff = o; if (col >= dcols) { col -= dcols; coff += 1ULL << unit_shift; } rm->rm_col[c].rc_devidx = col; rm->rm_col[c].rc_offset = coff; rm->rm_col[c].rc_abd = NULL; rm->rm_col[c].rc_gdata = NULL; rm->rm_col[c].rc_error = 0; rm->rm_col[c].rc_tried = 0; rm->rm_col[c].rc_skipped = 0; if (c >= acols) rm->rm_col[c].rc_size = 0; else if (c < bc) rm->rm_col[c].rc_size = (q + 1) << unit_shift; else rm->rm_col[c].rc_size = q << unit_shift; asize += rm->rm_col[c].rc_size; } ASSERT3U(asize, ==, tot << unit_shift); rm->rm_asize = roundup(asize, (nparity + 1) << unit_shift); rm->rm_nskip = roundup(tot, nparity + 1) - tot; ASSERT3U(rm->rm_asize - asize, ==, rm->rm_nskip << unit_shift); ASSERT3U(rm->rm_nskip, <=, nparity); if (!dofree) { for (c = 0; c < rm->rm_firstdatacol; c++) { rm->rm_col[c].rc_abd = abd_alloc_linear(rm->rm_col[c].rc_size, B_TRUE); } rm->rm_col[c].rc_abd = abd_get_offset(abd, 0); off = rm->rm_col[c].rc_size; for (c = c + 1; c < acols; c++) { rm->rm_col[c].rc_abd = abd_get_offset(abd, off); off += rm->rm_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. */ ASSERT(rm->rm_cols >= 2); ASSERT(rm->rm_col[0].rc_size == rm->rm_col[1].rc_size); if (rm->rm_firstdatacol == 1 && (offset & (1ULL << 20))) { devidx = rm->rm_col[0].rc_devidx; o = rm->rm_col[0].rc_offset; rm->rm_col[0].rc_devidx = rm->rm_col[1].rc_devidx; rm->rm_col[0].rc_offset = rm->rm_col[1].rc_offset; rm->rm_col[1].rc_devidx = devidx; rm->rm_col[1].rc_offset = o; if (rm->rm_skipstart == 0) rm->rm_skipstart = 1; } 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_map_t *rm) { uint64_t *p; int c; abd_t *src; for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) { src = rm->rm_col[c].rc_abd; p = abd_to_buf(rm->rm_col[VDEV_RAIDZ_P].rc_abd); if (c == rm->rm_firstdatacol) { abd_copy_to_buf(p, src, rm->rm_col[c].rc_size); } else { struct pqr_struct pqr = { p, NULL, NULL }; (void) abd_iterate_func(src, 0, rm->rm_col[c].rc_size, vdev_raidz_p_func, &pqr); } } } static void vdev_raidz_generate_parity_pq(raidz_map_t *rm) { uint64_t *p, *q, pcnt, ccnt, mask, i; int c; abd_t *src; pcnt = rm->rm_col[VDEV_RAIDZ_P].rc_size / sizeof (p[0]); ASSERT(rm->rm_col[VDEV_RAIDZ_P].rc_size == rm->rm_col[VDEV_RAIDZ_Q].rc_size); for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) { src = rm->rm_col[c].rc_abd; p = abd_to_buf(rm->rm_col[VDEV_RAIDZ_P].rc_abd); q = abd_to_buf(rm->rm_col[VDEV_RAIDZ_Q].rc_abd); ccnt = rm->rm_col[c].rc_size / sizeof (p[0]); if (c == rm->rm_firstdatacol) { abd_copy_to_buf(p, src, rm->rm_col[c].rc_size); (void) memcpy(q, p, rm->rm_col[c].rc_size); } else { struct pqr_struct pqr = { p, q, NULL }; (void) abd_iterate_func(src, 0, rm->rm_col[c].rc_size, vdev_raidz_pq_func, &pqr); } if (c == rm->rm_firstdatacol) { for (i = ccnt; i < pcnt; i++) { p[i] = 0; q[i] = 0; } } else { /* * Treat short columns as though they are full of 0s. * Note that there's therefore nothing needed for P. */ for (i = ccnt; i < pcnt; i++) { VDEV_RAIDZ_64MUL_2(q[i], mask); } } } } static void vdev_raidz_generate_parity_pqr(raidz_map_t *rm) { uint64_t *p, *q, *r, pcnt, ccnt, mask, i; int c; abd_t *src; pcnt = rm->rm_col[VDEV_RAIDZ_P].rc_size / sizeof (p[0]); ASSERT(rm->rm_col[VDEV_RAIDZ_P].rc_size == rm->rm_col[VDEV_RAIDZ_Q].rc_size); ASSERT(rm->rm_col[VDEV_RAIDZ_P].rc_size == rm->rm_col[VDEV_RAIDZ_R].rc_size); for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) { src = rm->rm_col[c].rc_abd; p = abd_to_buf(rm->rm_col[VDEV_RAIDZ_P].rc_abd); q = abd_to_buf(rm->rm_col[VDEV_RAIDZ_Q].rc_abd); r = abd_to_buf(rm->rm_col[VDEV_RAIDZ_R].rc_abd); ccnt = rm->rm_col[c].rc_size / sizeof (p[0]); if (c == rm->rm_firstdatacol) { abd_copy_to_buf(p, src, rm->rm_col[c].rc_size); (void) memcpy(q, p, rm->rm_col[c].rc_size); (void) memcpy(r, p, rm->rm_col[c].rc_size); } else { struct pqr_struct pqr = { p, q, r }; (void) abd_iterate_func(src, 0, rm->rm_col[c].rc_size, vdev_raidz_pqr_func, &pqr); } if (c == rm->rm_firstdatacol) { for (i = ccnt; i < pcnt; i++) { p[i] = 0; q[i] = 0; r[i] = 0; } } else { /* * Treat short columns as though they are full of 0s. * Note that there's therefore nothing needed for P. */ for (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. */ static void vdev_raidz_generate_parity(raidz_map_t *rm) { switch (rm->rm_firstdatacol) { case 1: vdev_raidz_generate_parity_p(rm); break; case 2: vdev_raidz_generate_parity_pq(rm); break; case 3: vdev_raidz_generate_parity_pqr(rm); break; default: cmn_err(CE_PANIC, "invalid RAID-Z configuration"); } } /* 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++) { *dst ^= *rq->q; int j; uint8_t *b; 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_map_t *rm, int *tgts, int ntgts) { int x = tgts[0]; int c; abd_t *dst, *src; ASSERT(ntgts == 1); ASSERT(x >= rm->rm_firstdatacol); ASSERT(x < rm->rm_cols); ASSERT(rm->rm_col[x].rc_size <= rm->rm_col[VDEV_RAIDZ_P].rc_size); ASSERT(rm->rm_col[x].rc_size > 0); src = rm->rm_col[VDEV_RAIDZ_P].rc_abd; dst = rm->rm_col[x].rc_abd; abd_copy(dst, src, rm->rm_col[x].rc_size); for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) { uint64_t size = MIN(rm->rm_col[x].rc_size, rm->rm_col[c].rc_size); src = rm->rm_col[c].rc_abd; dst = rm->rm_col[x].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_map_t *rm, int *tgts, int ntgts) { int x = tgts[0]; int c, exp; abd_t *dst, *src; ASSERT(ntgts == 1); ASSERT(rm->rm_col[x].rc_size <= rm->rm_col[VDEV_RAIDZ_Q].rc_size); for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) { uint64_t size = (c == x) ? 0 : MIN(rm->rm_col[x].rc_size, rm->rm_col[c].rc_size); src = rm->rm_col[c].rc_abd; dst = rm->rm_col[x].rc_abd; if (c == rm->rm_firstdatacol) { abd_copy(dst, src, size); if (rm->rm_col[x].rc_size > size) abd_zero_off(dst, size, rm->rm_col[x].rc_size - size); } else { ASSERT3U(size, <=, rm->rm_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, rm->rm_col[x].rc_size - size, vdev_raidz_reconst_q_pre_tail_func, NULL); } } src = rm->rm_col[VDEV_RAIDZ_Q].rc_abd; dst = rm->rm_col[x].rc_abd; exp = 255 - (rm->rm_cols - 1 - x); struct reconst_q_struct rq = { abd_to_buf(src), exp }; (void) abd_iterate_func(dst, 0, rm->rm_col[x].rc_size, vdev_raidz_reconst_q_post_func, &rq); return (1 << VDEV_RAIDZ_Q); } static int vdev_raidz_reconstruct_pq(raidz_map_t *rm, 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 >= rm->rm_firstdatacol); ASSERT(y < rm->rm_cols); ASSERT(rm->rm_col[x].rc_size >= rm->rm_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 = rm->rm_col[VDEV_RAIDZ_P].rc_abd; qdata = rm->rm_col[VDEV_RAIDZ_Q].rc_abd; xsize = rm->rm_col[x].rc_size; ysize = rm->rm_col[y].rc_size; rm->rm_col[VDEV_RAIDZ_P].rc_abd = abd_alloc_linear(rm->rm_col[VDEV_RAIDZ_P].rc_size, B_TRUE); rm->rm_col[VDEV_RAIDZ_Q].rc_abd = abd_alloc_linear(rm->rm_col[VDEV_RAIDZ_Q].rc_size, B_TRUE); rm->rm_col[x].rc_size = 0; rm->rm_col[y].rc_size = 0; vdev_raidz_generate_parity_pq(rm); rm->rm_col[x].rc_size = xsize; rm->rm_col[y].rc_size = ysize; p = abd_to_buf(pdata); q = abd_to_buf(qdata); pxy = abd_to_buf(rm->rm_col[VDEV_RAIDZ_P].rc_abd); qxy = abd_to_buf(rm->rm_col[VDEV_RAIDZ_Q].rc_abd); xd = rm->rm_col[x].rc_abd; yd = rm->rm_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 - (rm->rm_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(rm->rm_col[VDEV_RAIDZ_P].rc_abd); abd_free(rm->rm_col[VDEV_RAIDZ_Q].rc_abd); /* * Restore the saved parity data. */ rm->rm_col[VDEV_RAIDZ_P].rc_abd = pdata; rm->rm_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 coeffecients 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 coeffecients 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 | * | 19 205 116 29 64 16 4 1 | * | 1 0 0 0 0 0 0 0 | * (V|I)' = | 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_map_t *rm, int n, int nmap, int *map, uint8_t **rows) { int i, j; int pow; ASSERT(n == rm->rm_cols - rm->rm_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_map_t *rm, 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], <, rm->rm_firstdatacol); } for (; i < n; i++) { ASSERT3S(used[i], >=, rm->rm_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], >=, rm->rm_firstdatacol); jj = used[j] - rm->rm_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_map_t *rm, 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]; uint64_t dcount[VDEV_RAIDZ_MAXPARITY]; 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, <, rm->rm_cols); src = abd_to_buf(rm->rm_col[c].rc_abd); ccount = rm->rm_col[c].rc_size; for (j = 0; j < nmissing; j++) { cc = missing[j] + rm->rm_firstdatacol; ASSERT3U(cc, >=, rm->rm_firstdatacol); ASSERT3U(cc, <, rm->rm_cols); ASSERT3U(cc, !=, c); dst[j] = abd_to_buf(rm->rm_col[cc].rc_abd); dcount[j] = rm->rm_col[cc].rc_size; } ASSERT(ccount >= rm->rm_col[missing[0]].rc_size || i > 0); 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_map_t *rm, 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 (!abd_is_linear(rm->rm_col[rm->rm_firstdatacol].rc_abd)) { bufs = kmem_alloc(rm->rm_cols * sizeof (abd_t *), KM_PUSHPAGE); for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) { raidz_col_t *col = &rm->rm_col[c]; bufs[c] = col->rc_abd; col->rc_abd = abd_alloc_linear(col->rc_size, B_TRUE); abd_copy(col->rc_abd, bufs[c], col->rc_size); } } n = rm->rm_cols - rm->rm_firstdatacol; /* * Figure out which data columns are missing. */ nmissing_rows = 0; for (t = 0; t < ntgts; t++) { if (tgts[t] >= rm->rm_firstdatacol) { missing_rows[nmissing_rows++] = tgts[t] - rm->rm_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 < rm->rm_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 = rm->rm_firstdatacol; c < rm->rm_cols; c++) { if (tt < nmissing_rows && c == missing_rows[tt] + rm->rm_firstdatacol) { tt++; continue; } ASSERT3S(i, <, n); used[i] = c; i++; } /* * Initialize the interesting rows of the matrix. */ vdev_raidz_matrix_init(rm, n, nmissing_rows, parity_map, rows); /* * Invert the matrix. */ vdev_raidz_matrix_invert(rm, n, nmissing_rows, missing_rows, rows, invrows, used); /* * Reconstruct the missing data using the generated matrix. */ vdev_raidz_matrix_reconstruct(rm, n, nmissing_rows, missing_rows, invrows, used); kmem_free(p, psize); /* * copy back from temporary linear abds and free them */ if (bufs) { for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) { raidz_col_t *col = &rm->rm_col[c]; abd_copy(bufs[c], col->rc_abd, col->rc_size); abd_free(col->rc_abd); col->rc_abd = bufs[c]; } kmem_free(bufs, rm->rm_cols * sizeof (abd_t *)); } return (code); } static int vdev_raidz_reconstruct(raidz_map_t *rm, int *t, int nt) { int tgts[VDEV_RAIDZ_MAXPARITY], *dt; int ntgts; int i, c; int code; int nbadparity, nbaddata; int parity_valid[VDEV_RAIDZ_MAXPARITY]; /* * The tgts list must already be sorted. */ for (i = 1; i < nt; i++) { ASSERT(t[i] > t[i - 1]); } nbadparity = rm->rm_firstdatacol; nbaddata = rm->rm_cols - nbadparity; ntgts = 0; for (i = 0, c = 0; c < rm->rm_cols; c++) { if (c < rm->rm_firstdatacol) parity_valid[c] = B_FALSE; if (i < nt && c == t[i]) { tgts[ntgts++] = c; i++; } else if (rm->rm_col[c].rc_error != 0) { tgts[ntgts++] = c; } else if (c >= rm->rm_firstdatacol) { nbaddata--; } else { parity_valid[c] = B_TRUE; nbadparity--; } } ASSERT(ntgts >= nt); ASSERT(nbaddata >= 0); ASSERT(nbaddata + nbadparity == ntgts); dt = &tgts[nbadparity]; /* * See if we can use any of our optimized reconstruction routines. */ if (!vdev_raidz_default_to_general) { switch (nbaddata) { case 1: if (parity_valid[VDEV_RAIDZ_P]) return (vdev_raidz_reconstruct_p(rm, dt, 1)); ASSERT(rm->rm_firstdatacol > 1); if (parity_valid[VDEV_RAIDZ_Q]) return (vdev_raidz_reconstruct_q(rm, dt, 1)); ASSERT(rm->rm_firstdatacol > 2); break; case 2: ASSERT(rm->rm_firstdatacol > 1); if (parity_valid[VDEV_RAIDZ_P] && parity_valid[VDEV_RAIDZ_Q]) return (vdev_raidz_reconstruct_pq(rm, dt, 2)); ASSERT(rm->rm_firstdatacol > 2); break; } } code = vdev_raidz_reconstruct_general(rm, 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_t *cvd; uint64_t nparity = vd->vdev_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++) { 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) { int c; for (c = 0; c < vd->vdev_children; c++) vdev_close(vd->vdev_child[c]); } #ifdef illumos /* * Handle a read or write I/O to a RAID-Z dump device. * * The dump device is in a unique situation compared to other ZFS datasets: * writing to this device should be as simple and fast as possible. In * addition, durability matters much less since the dump will be extracted * once the machine reboots. For that reason, this function eschews parity for * performance and simplicity. The dump device uses the checksum setting * ZIO_CHECKSUM_NOPARITY to indicate that parity is not maintained for this * dataset. * * Blocks of size 128 KB have been preallocated for this volume. I/Os less than * 128 KB will not fill an entire block; in addition, they may not be properly * aligned. In that case, this function uses the preallocated 128 KB block and * omits reading or writing any "empty" portions of that block, as opposed to * allocating a fresh appropriately-sized block. * * Looking at an example of a 32 KB I/O to a RAID-Z vdev with 5 child vdevs: * * vdev_raidz_io_start(data, size: 32 KB, offset: 64 KB) * * If this were a standard RAID-Z dataset, a block of at least 40 KB would be * allocated which spans all five child vdevs. 8 KB of data would be written to * each of four vdevs, with the fifth containing the parity bits. * * parity data data data data * | PP | XX | XX | XX | XX | * ^ ^ ^ ^ ^ * | | | | | * 8 KB parity ------8 KB data blocks------ * * However, when writing to the dump device, the behavior is different: * * vdev_raidz_physio(data, size: 32 KB, offset: 64 KB) * * Unlike the normal RAID-Z case in which the block is allocated based on the * I/O size, reads and writes here always use a 128 KB logical I/O size. If the * I/O size is less than 128 KB, only the actual portions of data are written. * In this example the data is written to the third data vdev since that vdev * contains the offset [64 KB, 96 KB). * * parity data data data data * | | | | XX | | * ^ * | * 32 KB data block * * As a result, an individual I/O may not span all child vdevs; moreover, a * small I/O may only operate on a single child vdev. * * Note that since there are no parity bits calculated or written, this format * remains the same no matter how many parity bits are used in a normal RAID-Z * stripe. On a RAID-Z3 configuration with seven child vdevs, the example above * would look like: * * parity parity parity data data data data * | | | | | | XX | | * ^ * | * 32 KB data block */ int vdev_raidz_physio(vdev_t *vd, caddr_t data, size_t size, uint64_t offset, uint64_t origoffset, boolean_t doread, boolean_t isdump) { vdev_t *tvd = vd->vdev_top; vdev_t *cvd; raidz_map_t *rm; raidz_col_t *rc; int c, err = 0; uint64_t start, end, colstart, colend; uint64_t coloffset, colsize, colskip; int flags = doread ? BIO_READ : BIO_WRITE; #ifdef _KERNEL /* * Don't write past the end of the block */ VERIFY3U(offset + size, <=, origoffset + SPA_OLD_MAXBLOCKSIZE); start = offset; end = start + size; /* * Allocate a RAID-Z map for this block. Note that this block starts * from the "original" offset, this is, the offset of the extent which * contains the requisite offset of the data being read or written. * * Even if this I/O operation doesn't span the full block size, let's * treat the on-disk format as if the only blocks are the complete 128 * KB size. */ abd_t *abd = abd_get_from_buf(data - (offset - origoffset), SPA_OLD_MAXBLOCKSIZE); rm = vdev_raidz_map_alloc(abd, SPA_OLD_MAXBLOCKSIZE, origoffset, B_FALSE, tvd->vdev_ashift, vd->vdev_children, vd->vdev_nparity); coloffset = origoffset; for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++, coloffset += rc->rc_size) { rc = &rm->rm_col[c]; cvd = vd->vdev_child[rc->rc_devidx]; /* * Find the start and end of this column in the RAID-Z map, * keeping in mind that the stated size and offset of the * operation may not fill the entire column for this vdev. * * If any portion of the data spans this column, issue the * appropriate operation to the vdev. */ if (coloffset + rc->rc_size <= start) continue; if (coloffset >= end) continue; colstart = MAX(coloffset, start); colend = MIN(end, coloffset + rc->rc_size); colsize = colend - colstart; colskip = colstart - coloffset; VERIFY3U(colsize, <=, rc->rc_size); VERIFY3U(colskip, <=, rc->rc_size); /* * Note that the child vdev will have a vdev label at the start * of its range of offsets, hence the need for * VDEV_LABEL_OFFSET(). See zio_vdev_child_io() for another * example of why this calculation is needed. */ if ((err = vdev_disk_physio(cvd, ((char *)abd_to_buf(rc->rc_abd)) + colskip, colsize, VDEV_LABEL_OFFSET(rc->rc_offset) + colskip, flags, isdump)) != 0) break; } vdev_raidz_map_free(rm); abd_put(abd); #endif /* KERNEL */ return (err); } #endif static uint64_t vdev_raidz_asize(vdev_t *vd, uint64_t psize) { uint64_t asize; uint64_t ashift = vd->vdev_top->vdev_ashift; uint64_t cols = vd->vdev_children; uint64_t nparity = vd->vdev_nparity; asize = ((psize - 1) >> ashift) + 1; asize += nparity * ((asize + cols - nparity - 1) / (cols - nparity)); asize = roundup(asize, nparity + 1) << ashift; return (asize); } static 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; } /* * 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_t *cvd; raidz_map_t *rm; raidz_col_t *rc; int c, i; rm = vdev_raidz_map_alloc(zio->io_abd, zio->io_size, zio->io_offset, zio->io_type == ZIO_TYPE_FREE, tvd->vdev_ashift, vd->vdev_children, vd->vdev_nparity); zio->io_vsd = rm; zio->io_vsd_ops = &vdev_raidz_vsd_ops; ASSERT3U(rm->rm_asize, ==, vdev_psize_to_asize(vd, zio->io_size)); if (zio->io_type == ZIO_TYPE_FREE) { for (c = 0; c < rm->rm_cols; c++) { rc = &rm->rm_col[c]; cvd = vd->vdev_child[rc->rc_devidx]; 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)); } zio_execute(zio); return; } if (zio->io_type == ZIO_TYPE_WRITE) { vdev_raidz_generate_parity(rm); for (c = 0; c < rm->rm_cols; c++) { rc = &rm->rm_col[c]; cvd = vd->vdev_child[rc->rc_devidx]; 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)); } /* * Generate optional I/Os for any skipped sectors to improve * aggregation contiguity. */ for (c = rm->rm_skipstart, i = 0; i < rm->rm_nskip; c++, i++) { ASSERT(c <= rm->rm_scols); if (c == rm->rm_scols) c = 0; rc = &rm->rm_col[c]; cvd = vd->vdev_child[rc->rc_devidx]; zio_nowait(zio_vdev_child_io(zio, NULL, cvd, rc->rc_offset + rc->rc_size, NULL, 1 << tvd->vdev_ashift, zio->io_type, zio->io_priority, ZIO_FLAG_NODATA | ZIO_FLAG_OPTIONAL, NULL, NULL)); } zio_execute(zio); return; } ASSERT(zio->io_type == ZIO_TYPE_READ); /* * 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 (c = rm->rm_cols - 1; c >= 0; c--) { rc = &rm->rm_col[c]; cvd = vd->vdev_child[rc->rc_devidx]; if (!vdev_readable(cvd)) { if (c >= rm->rm_firstdatacol) rm->rm_missingdata++; else rm->rm_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 >= rm->rm_firstdatacol) rm->rm_missingdata++; else rm->rm_missingparity++; rc->rc_error = SET_ERROR(ESTALE); rc->rc_skipped = 1; continue; } if (c >= rm->rm_firstdatacol || rm->rm_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)); } } 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, void *bad_data) { void *buf; vdev_t *vd = zio->io_vd->vdev_child[rc->rc_devidx]; if (!(zio->io_flags & ZIO_FLAG_SPECULATIVE)) { zio_bad_cksum_t zbc; raidz_map_t *rm = zio->io_vsd; mutex_enter(&vd->vdev_stat_lock); vd->vdev_stat.vs_checksum_errors++; mutex_exit(&vd->vdev_stat_lock); zbc.zbc_has_cksum = 0; zbc.zbc_injected = rm->rm_ecksuminjected; buf = abd_borrow_buf_copy(rc->rc_abd, rc->rc_size); zfs_ereport_post_checksum(zio->io_spa, vd, zio, rc->rc_offset, rc->rc_size, buf, bad_data, &zbc); abd_return_buf(rc->rc_abd, buf, rc->rc_size); } } /* * 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; 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 such failures. */ static int raidz_parity_verify(zio_t *zio, raidz_map_t *rm) { void *orig[VDEV_RAIDZ_MAXPARITY]; int c, ret = 0; 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); for (c = 0; c < rm->rm_firstdatacol; c++) { rc = &rm->rm_col[c]; if (!rc->rc_tried || rc->rc_error != 0) continue; orig[c] = zio_buf_alloc(rc->rc_size); abd_copy_to_buf(orig[c], rc->rc_abd, rc->rc_size); } vdev_raidz_generate_parity(rm); for (c = 0; c < rm->rm_firstdatacol; c++) { rc = &rm->rm_col[c]; if (!rc->rc_tried || rc->rc_error != 0) continue; if (abd_cmp_buf(rc->rc_abd, orig[c], rc->rc_size) != 0) { raidz_checksum_error(zio, rc, orig[c]); rc->rc_error = SET_ERROR(ECKSUM); ret++; } zio_buf_free(orig[c], rc->rc_size); } return (ret); } /* * Keep statistics on all the ways that we used parity to correct data. */ static uint64_t raidz_corrected[1 << VDEV_RAIDZ_MAXPARITY]; static int vdev_raidz_worst_error(raidz_map_t *rm) { int error = 0; for (int c = 0; c < rm->rm_cols; c++) error = zio_worst_error(error, rm->rm_col[c].rc_error); return (error); } /* * Iterate over all combinations of bad data 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. */ static int vdev_raidz_combrec(zio_t *zio, int total_errors, int data_errors) { raidz_map_t *rm = zio->io_vsd; raidz_col_t *rc; void *orig[VDEV_RAIDZ_MAXPARITY]; int tstore[VDEV_RAIDZ_MAXPARITY + 2]; int *tgts = &tstore[1]; int current, next, i, c, n; int code, ret = 0; ASSERT(total_errors < rm->rm_firstdatacol); /* * This simplifies one edge condition. */ tgts[-1] = -1; for (n = 1; n <= rm->rm_firstdatacol - total_errors; n++) { /* * Initialize the targets array by finding the first n columns * that contain no error. * * If there were no data errors, we need to ensure that we're * always explicitly attempting to reconstruct at least one * data column. To do this, we simply push the highest target * up into the data columns. */ for (c = 0, i = 0; i < n; i++) { if (i == n - 1 && data_errors == 0 && c < rm->rm_firstdatacol) { c = rm->rm_firstdatacol; } while (rm->rm_col[c].rc_error != 0) { c++; ASSERT3S(c, <, rm->rm_cols); } tgts[i] = c++; } /* * Setting tgts[n] simplifies the other edge condition. */ tgts[n] = rm->rm_cols; /* * These buffers were allocated in previous iterations. */ for (i = 0; i < n - 1; i++) { ASSERT(orig[i] != NULL); } orig[n - 1] = zio_buf_alloc(rm->rm_col[0].rc_size); current = 0; next = tgts[current]; while (current != n) { tgts[current] = next; current = 0; /* * Save off the original data that we're going to * attempt to reconstruct. */ for (i = 0; i < n; i++) { ASSERT(orig[i] != NULL); c = tgts[i]; ASSERT3S(c, >=, 0); ASSERT3S(c, <, rm->rm_cols); rc = &rm->rm_col[c]; abd_copy_to_buf(orig[i], rc->rc_abd, rc->rc_size); } /* * Attempt a reconstruction and exit the outer loop on * success. */ code = vdev_raidz_reconstruct(rm, tgts, n); if (raidz_checksum_verify(zio) == 0) { atomic_inc_64(&raidz_corrected[code]); for (i = 0; i < n; i++) { c = tgts[i]; rc = &rm->rm_col[c]; ASSERT(rc->rc_error == 0); if (rc->rc_tried) raidz_checksum_error(zio, rc, orig[i]); rc->rc_error = SET_ERROR(ECKSUM); } ret = code; goto done; } /* * Restore the original data. */ for (i = 0; i < n; i++) { c = tgts[i]; rc = &rm->rm_col[c]; abd_copy_from_buf(rc->rc_abd, orig[i], rc->rc_size); } do { /* * Find the next valid column after the current * position.. */ for (next = tgts[current] + 1; next < rm->rm_cols && rm->rm_col[next].rc_error != 0; next++) continue; ASSERT(next <= tgts[current + 1]); /* * If that spot is available, we're done here. */ if (next != tgts[current + 1]) break; /* * Otherwise, find the next valid column after * the previous position. */ for (c = tgts[current - 1] + 1; rm->rm_col[c].rc_error != 0; c++) continue; tgts[current] = c; current++; } while (current != n); } } n--; done: for (i = 0; i < n; i++) { zio_buf_free(orig[i], rm->rm_col[0].rc_size); } return (ret); } /* * Complete an IO operation on a RAIDZ VDev * * Outline: * - For write operations: * 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. * - For read operations: * 1. Check for errors on the child IOs. * 2. If data errors occurred: * a. Try to reassemble the data from the parity available. * b. If we haven't yet read the parity drives, read them now. * c. If all parity drives have been read but the data still doesn't * reassemble with a correct checksum, then try combinatorial * reconstruction. * d. If that doesn't work, return an error. * 3. If there were unexpected errors or this is a resilver operation, * rewrite the vdevs that had errors. */ static void vdev_raidz_io_done(zio_t *zio) { vdev_t *vd = zio->io_vd; vdev_t *cvd; raidz_map_t *rm = zio->io_vsd; raidz_col_t *rc; int unexpected_errors = 0; int parity_errors = 0; int parity_untried = 0; int data_errors = 0; int total_errors = 0; int n, c; int tgts[VDEV_RAIDZ_MAXPARITY]; int code; ASSERT(zio->io_bp != NULL); /* XXX need to add code to enforce this */ ASSERT(rm->rm_missingparity <= rm->rm_firstdatacol); ASSERT(rm->rm_missingdata <= rm->rm_cols - rm->rm_firstdatacol); for (c = 0; c < rm->rm_cols; c++) { rc = &rm->rm_col[c]; if (rc->rc_error) { ASSERT(rc->rc_error != ECKSUM); /* child has no bp */ if (c < rm->rm_firstdatacol) parity_errors++; else data_errors++; if (!rc->rc_skipped) unexpected_errors++; total_errors++; } else if (c < rm->rm_firstdatacol && !rc->rc_tried) { parity_untried++; } } if (zio->io_type == ZIO_TYPE_WRITE) { /* * XXX -- for now, 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. */ /* XXPOLICY */ if (total_errors > rm->rm_firstdatacol) zio->io_error = vdev_raidz_worst_error(rm); return; } else if (zio->io_type == ZIO_TYPE_FREE) { return; } ASSERT(zio->io_type == ZIO_TYPE_READ); /* * There are three potential phases for a read: * 1. produce valid data from the columns read * 2. read all disks and try again * 3. perform combinatorial reconstruction * * Each phase is progressively both more expensive and less likely to * occur. If we encounter more errors than we can repair or all phases * fail, we have no choice but to return an error. */ /* * If the number of errors we saw was correctable -- less than or equal * to the number of parity disks read -- attempt to produce data that * has a valid checksum. Naturally, this case applies in the absence of * any errors. */ if (total_errors <= rm->rm_firstdatacol - parity_untried) { if (data_errors == 0) { if (raidz_checksum_verify(zio) == 0) { /* * If we read parity information (unnecessarily * as it happens since no reconstruction was * needed) regenerate and verify the parity. * We also regenerate parity when resilvering * so we can write it out to the failed device * later. */ if (parity_errors + parity_untried < rm->rm_firstdatacol || (zio->io_flags & ZIO_FLAG_RESILVER)) { n = raidz_parity_verify(zio, rm); unexpected_errors += n; ASSERT(parity_errors + n <= rm->rm_firstdatacol); } goto done; } } else { /* * 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 < rm->rm_firstdatacol); /* * Identify the data columns that reported an error. */ n = 0; for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) { rc = &rm->rm_col[c]; if (rc->rc_error != 0) { ASSERT(n < VDEV_RAIDZ_MAXPARITY); tgts[n++] = c; } } ASSERT(rm->rm_firstdatacol >= n); code = vdev_raidz_reconstruct(rm, tgts, n); if (raidz_checksum_verify(zio) == 0) { atomic_inc_64(&raidz_corrected[code]); /* * If we read more parity disks than were used * for reconstruction, confirm that the other * parity disks produced correct data. This * routine is suboptimal in that it regenerates * the parity that we already used in addition * to the parity that we're attempting to * verify, but this should be a relatively * uncommon case, and can be optimized if it * becomes a problem. Note that we regenerate * parity when resilvering so we can write it * out to failed devices later. */ if (parity_errors < rm->rm_firstdatacol - n || (zio->io_flags & ZIO_FLAG_RESILVER)) { n = raidz_parity_verify(zio, rm); unexpected_errors += n; ASSERT(parity_errors + n <= rm->rm_firstdatacol); } goto done; } } } /* * 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. */ unexpected_errors = 1; rm->rm_missingdata = 0; rm->rm_missingparity = 0; for (c = 0; c < rm->rm_cols; c++) { if (rm->rm_col[c].rc_tried) continue; zio_vdev_io_redone(zio); do { rc = &rm->rm_col[c]; if (rc->rc_tried) 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)); } while (++c < rm->rm_cols); return; } /* * At this point we've attempted to reconstruct the data given the * errors we detected, and we've attempted to read all columns. There * must, therefore, be one or more additional problems -- silent errors * resulting in invalid data rather than explicit I/O errors resulting * in absent data. We check if there is enough additional data to * possibly reconstruct the data and then perform combinatorial * reconstruction over all possible combinations. If that fails, * we're cooked. */ if (total_errors > rm->rm_firstdatacol) { zio->io_error = vdev_raidz_worst_error(rm); } else if (total_errors < rm->rm_firstdatacol && (code = vdev_raidz_combrec(zio, total_errors, data_errors)) != 0) { /* * If we didn't use all the available parity for the * combinatorial reconstruction, verify that the remaining * parity is correct. */ if (code != (1 << rm->rm_firstdatacol) - 1) (void) raidz_parity_verify(zio, rm); } else { /* * We're here because either: * * total_errors == rm_first_datacol, or * vdev_raidz_combrec() failed * * In either case, there is enough bad data to prevent * reconstruction. * * Start checksum ereports for all children which haven't * failed, and the IO wasn't speculative. */ zio->io_error = SET_ERROR(ECKSUM); if (!(zio->io_flags & ZIO_FLAG_SPECULATIVE)) { for (c = 0; c < rm->rm_cols; c++) { rc = &rm->rm_col[c]; if (rc->rc_error == 0) { zio_bad_cksum_t zbc; zbc.zbc_has_cksum = 0; zbc.zbc_injected = rm->rm_ecksuminjected; zfs_ereport_start_checksum( zio->io_spa, vd->vdev_child[rc->rc_devidx], zio, rc->rc_offset, rc->rc_size, (void *)(uintptr_t)c, &zbc); } } } } done: zio_checksum_verified(zio); if (zio->io_error == 0 && spa_writeable(zio->io_spa) && (unexpected_errors || (zio->io_flags & ZIO_FLAG_RESILVER))) { /* * Use the good data we have in hand to repair damaged children. */ for (c = 0; c < rm->rm_cols; c++) { rc = &rm->rm_col[c]; cvd = vd->vdev_child[rc->rc_devidx]; if (rc->rc_error == 0) continue; zio_nowait(zio_vdev_child_io(zio, NULL, cvd, rc->rc_offset, rc->rc_abd, rc->rc_size, ZIO_TYPE_WRITE, ZIO_PRIORITY_ASYNC_WRITE, ZIO_FLAG_IO_REPAIR | (unexpected_errors ? ZIO_FLAG_SELF_HEAL : 0), NULL, NULL)); } } } static void vdev_raidz_state_change(vdev_t *vd, int faulted, int degraded) { if (faulted > vd->vdev_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); } vdev_ops_t vdev_raidz_ops = { vdev_raidz_open, vdev_raidz_close, vdev_raidz_asize, vdev_raidz_io_start, vdev_raidz_io_done, vdev_raidz_state_change, NULL, NULL, VDEV_TYPE_RAIDZ, /* name of this vdev type */ B_FALSE /* not a leaf vdev */ }; Index: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c =================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c (revision 320184) +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c (revision 320185) @@ -1,4134 +1,4139 @@ /* * 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, 2017 by Delphix. All rights reserved. * Copyright (c) 2011 Nexenta Systems, Inc. All rights reserved. * Copyright (c) 2014 Integros [integros.com] */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include SYSCTL_DECL(_vfs_zfs); SYSCTL_NODE(_vfs_zfs, OID_AUTO, zio, CTLFLAG_RW, 0, "ZFS ZIO"); #if defined(__amd64__) static int zio_use_uma = 1; #else static int zio_use_uma = 0; #endif SYSCTL_INT(_vfs_zfs_zio, OID_AUTO, use_uma, CTLFLAG_RDTUN, &zio_use_uma, 0, "Use uma(9) for ZIO allocations"); static int zio_exclude_metadata = 0; SYSCTL_INT(_vfs_zfs_zio, OID_AUTO, exclude_metadata, CTLFLAG_RDTUN, &zio_exclude_metadata, 0, "Exclude metadata buffers from dumps as well"); zio_trim_stats_t zio_trim_stats = { { "bytes", KSTAT_DATA_UINT64, "Number of bytes successfully TRIMmed" }, { "success", KSTAT_DATA_UINT64, "Number of successful TRIM requests" }, { "unsupported", KSTAT_DATA_UINT64, "Number of TRIM requests that failed because TRIM is not supported" }, { "failed", KSTAT_DATA_UINT64, "Number of TRIM requests that failed for reasons other than not supported" }, }; static kstat_t *zio_trim_ksp; /* * ========================================================================== * I/O type descriptions * ========================================================================== */ const char *zio_type_name[ZIO_TYPES] = { "zio_null", "zio_read", "zio_write", "zio_free", "zio_claim", "zio_ioctl" }; boolean_t zio_dva_throttle_enabled = B_TRUE; SYSCTL_INT(_vfs_zfs_zio, OID_AUTO, dva_throttle_enabled, CTLFLAG_RDTUN, &zio_dva_throttle_enabled, 0, ""); /* * ========================================================================== * 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]; #ifdef _KERNEL extern vmem_t *zio_alloc_arena; #endif #define ZIO_PIPELINE_CONTINUE 0x100 #define ZIO_PIPELINE_STOP 0x101 #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. */ int zfs_sync_pass_deferred_free = 2; /* defer frees starting in this pass */ SYSCTL_INT(_vfs_zfs, OID_AUTO, sync_pass_deferred_free, CTLFLAG_RDTUN, &zfs_sync_pass_deferred_free, 0, "defer frees starting in this pass"); int zfs_sync_pass_dont_compress = 5; /* don't compress starting in this pass */ SYSCTL_INT(_vfs_zfs, OID_AUTO, sync_pass_dont_compress, CTLFLAG_RDTUN, &zfs_sync_pass_dont_compress, 0, "don't compress starting in this pass"); int zfs_sync_pass_rewrite = 2; /* rewrite new bps starting in this pass */ SYSCTL_INT(_vfs_zfs, OID_AUTO, sync_pass_rewrite, CTLFLAG_RDTUN, &zfs_sync_pass_rewrite, 0, "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) boolean_t zio_requeue_io_start_cut_in_line = B_TRUE; #ifdef illumos #ifdef ZFS_DEBUG int zio_buf_debug_limit = 16384; #else int zio_buf_debug_limit = 0; #endif #endif 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); if (!zio_use_uma) goto out; /* * 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; int cflags = zio_exclude_metadata ? KMC_NODEBUG : 0; while (!ISP2(p2)) p2 &= p2 - 1; #ifdef illumos #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; #endif #endif /* illumos */ if (size <= 4 * SPA_MINBLOCKSIZE) { align = SPA_MINBLOCKSIZE; } else if (IS_P2ALIGNED(size, p2 >> 2)) { align = MIN(p2 >> 2, PAGESIZE); } if (align != 0) { char name[36]; (void) sprintf(name, "zio_buf_%lu", (ulong_t)size); zio_buf_cache[c] = kmem_cache_create(name, size, align, NULL, NULL, NULL, NULL, NULL, cflags); /* * Since zio_data bufs do not appear in crash dumps, we * pass KMC_NOTOUCH so that no allocator metadata is * stored with the buffers. */ (void) sprintf(name, "zio_data_buf_%lu", (ulong_t)size); zio_data_buf_cache[c] = kmem_cache_create(name, size, align, NULL, NULL, NULL, NULL, NULL, cflags | KMC_NOTOUCH | KMC_NODEBUG); } } 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]; } out: zio_inject_init(); zio_trim_ksp = kstat_create("zfs", 0, "zio_trim", "misc", KSTAT_TYPE_NAMED, sizeof(zio_trim_stats) / sizeof(kstat_named_t), KSTAT_FLAG_VIRTUAL); if (zio_trim_ksp != NULL) { zio_trim_ksp->ks_data = &zio_trim_stats; kstat_install(zio_trim_ksp); } } 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++) { 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(); if (zio_trim_ksp != NULL) { kstat_delete(zio_trim_ksp); zio_trim_ksp = NULL; } } /* * ========================================================================== * 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; int flags = zio_exclude_metadata ? KM_NODEBUG : 0; VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); if (zio_use_uma) return (kmem_cache_alloc(zio_buf_cache[c], KM_PUSHPAGE)); else return (kmem_alloc(size, KM_SLEEP|flags)); } /* * 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); if (zio_use_uma) return (kmem_cache_alloc(zio_data_buf_cache[c], KM_PUSHPAGE)); else return (kmem_alloc(size, KM_SLEEP | KM_NODEBUG)); } void zio_buf_free(void *buf, size_t size) { size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); if (zio_use_uma) kmem_cache_free(zio_buf_cache[c], buf); else kmem_free(buf, size); } void zio_data_buf_free(void *buf, size_t size) { size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); if (zio_use_uma) kmem_cache_free(zio_data_buf_cache[c], buf); else kmem_free(buf, size); } /* * ========================================================================== * 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); /* * Ensure that anyone expecting this zio to contain a linear ABD isn't * going to get a nasty surprise when they try to access the data. */ +#ifdef illumos IMPLY(abd_is_linear(zio->io_abd), abd_is_linear(data)); +#else + IMPLY(zio->io_abd != NULL && abd_is_linear(zio->io_abd), + abd_is_linear(data)); +#endif 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 and decompression * ========================================================================== */ 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); abd_return_buf_copy(data, tmp, size); if (ret != 0) zio->io_error = SET_ERROR(EIO); } } /* * ========================================================================== * 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; *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. */ ASSERT(cio->io_child_type <= pio->io_child_type); zl->zl_parent = pio; zl->zl_child = cio; mutex_enter(&cio->io_lock); mutex_enter(&pio->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(&pio->io_lock); mutex_exit(&cio->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(&cio->io_lock); mutex_enter(&pio->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(&pio->io_lock); mutex_exit(&cio->io_lock); kmem_cache_free(zio_link_cache, zl); } static boolean_t zio_wait_for_children(zio_t *zio, enum zio_child child, enum zio_wait_type wait) { uint64_t *countp = &zio->io_children[child][wait]; boolean_t waiting = B_FALSE; mutex_enter(&zio->io_lock); ASSERT(zio->io_stall == NULL); if (*countp != 0) { zio->io_stage >>= 1; ASSERT3U(zio->io_stage, !=, ZIO_STAGE_OPEN); zio->io_stall = countp; waiting = B_TRUE; } mutex_exit(&zio->io_lock); return (waiting); } static void zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait) { 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); /* * Dispatch the parent zio in its own taskq so that * the child can continue to make progress. This also * prevents overflowing the stack when we have deeply nested * parent-child relationships. */ 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; ASSERT3U(type == ZIO_TYPE_FREE || 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) != 0); zio = kmem_cache_alloc(zio_cache, KM_SLEEP); bzero(zio, sizeof (zio_t)); mutex_init(&zio->io_lock, NULL, MUTEX_DEFAULT, 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_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); } 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)); } void zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp) { if (!DMU_OT_IS_VALID(BP_GET_TYPE(bp))) { zfs_panic_recover("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) { zfs_panic_recover("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) { zfs_panic_recover("blkptr at %p has invalid COMPRESS %llu", bp, (longlong_t)BP_GET_COMPRESS(bp)); } if (BP_GET_LSIZE(bp) > SPA_MAXBLOCKSIZE) { zfs_panic_recover("blkptr at %p has invalid LSIZE %llu", bp, (longlong_t)BP_GET_LSIZE(bp)); } if (BP_GET_PSIZE(bp) > SPA_MAXBLOCKSIZE) { zfs_panic_recover("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) { zfs_panic_recover("blkptr at %p has invalid ETYPE %llu", bp, (longlong_t)BPE_GET_ETYPE(bp)); } } /* * 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) { zfs_panic_recover("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) { zfs_panic_recover("blkptr at %p DVA %u has invalid " "VDEV %llu", bp, i, (longlong_t)vdevid); continue; } if (vd->vdev_ops == &vdev_hole_ops) { zfs_panic_recover("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) { zfs_panic_recover("blkptr at %p DVA %u has invalid " "OFFSET %llu", bp, i, (longlong_t)offset); } } } 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; zfs_blkptr_verify(spa, bp); 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). */ if (data == NULL && zio->io_prop.zp_dedup_verify) { 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) { /* * 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. */ if (zfs_trim_enabled || BP_IS_GANG(bp) || BP_GET_DEDUP(bp) || txg != spa->spa_syncing_txg || spa_sync_pass(spa) >= zfs_sync_pass_deferred_free) { bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp); } else { VERIFY0(zio_wait(zio_free_sync(NULL, spa, txg, bp, BP_GET_PSIZE(bp), 0))); } } zio_t * zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, uint64_t size, enum zio_flag flags) { zio_t *zio; enum zio_stage stage = ZIO_FREE_PIPELINE; ASSERT(!BP_IS_HOLE(bp)); ASSERT(spa_syncing_txg(spa) == txg); ASSERT(spa_sync_pass(spa) < zfs_sync_pass_deferred_free); if (BP_IS_EMBEDDED(bp)) return (zio_null(pio, spa, NULL, NULL, NULL, 0)); metaslab_check_free(spa, bp); arc_freed(spa, bp); if (zfs_trim_enabled) stage |= ZIO_STAGE_ISSUE_ASYNC | ZIO_STAGE_VDEV_IO_START | ZIO_STAGE_VDEV_IO_ASSESS; /* * 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. */ else if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp)) stage |= ZIO_STAGE_ISSUE_ASYNC; flags |= ZIO_FLAG_DONT_QUEUE; zio = zio_create(pio, spa, txg, bp, NULL, size, size, NULL, NULL, ZIO_TYPE_FREE, ZIO_PRIORITY_NOW, flags, NULL, 0, NULL, ZIO_STAGE_OPEN, stage); return (zio); } 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; dprintf_bp(bp, "claiming in txg %llu", txg); 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_first_txg(spa)); ASSERT(txg == spa_first_txg(spa) || txg == 0); ASSERT(!BP_GET_DEDUP(bp) || !spa_writeable(spa)); /* zdb(1M) */ 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, uint64_t offset, uint64_t size, zio_done_func_t *done, void *private, zio_priority_t priority, 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, offset, size, done, private, priority, 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; ASSERT(vd->vdev_parent == (pio->io_vd ? pio->io_vd : pio->io_spa->spa_root_vdev)); 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; } /* Not all IO types require vdev io done stage e.g. free */ if (!(pio->io_pipeline & ZIO_STAGE_VDEV_IO_DONE)) pipeline &= ~ZIO_STAGE_VDEV_IO_DONE; if (vd->vdev_children == 0) offset += VDEV_LABEL_START_SIZE; flags |= ZIO_VDEV_CHILD_FLAGS(pio) | ZIO_FLAG_DONT_PROPAGATE; /* * 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))) { metaslab_class_t *mc = spa_normal_class(pio->io_spa); ASSERT(mc->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, int 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, 0, 0, NULL, NULL, ZIO_PRIORITY_NOW, ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY)); } zio_t * zio_trim(zio_t *zio, spa_t *spa, vdev_t *vd, uint64_t offset, uint64_t size) { ASSERT(vd->vdev_ops->vdev_op_leaf); return (zio_create(zio, spa, 0, NULL, NULL, size, size, NULL, NULL, ZIO_TYPE_FREE, ZIO_PRIORITY_TRIM, ZIO_FLAG_DONT_AGGREGATE | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY, vd, offset, NULL, ZIO_STAGE_OPEN, ZIO_FREE_PHYS_PIPELINE)); } void zio_shrink(zio_t *zio, uint64_t size) { ASSERT(zio->io_executor == NULL); ASSERT(zio->io_orig_size == zio->io_size); ASSERT(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 int zio_read_bp_init(zio_t *zio) { blkptr_t *bp = zio->io_bp; if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF && zio->io_child_type == ZIO_CHILD_LOGICAL && !(zio->io_flags & ZIO_FLAG_RAW)) { uint64_t psize = BP_IS_EMBEDDED(bp) ? BPE_GET_PSIZE(bp) : BP_GET_PSIZE(bp); zio_push_transform(zio, abd_alloc_sametype(zio->io_abd, psize), psize, psize, zio_decompress); } if (BP_IS_EMBEDDED(bp) && BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA) { zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; int psize = BPE_GET_PSIZE(bp); void *data = abd_borrow_buf(zio->io_abd, psize); decode_embedded_bp_compressed(bp, data); abd_return_buf_copy(zio->io_abd, data, psize); } else { ASSERT(!BP_IS_EMBEDDED(bp)); } 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_PIPELINE_CONTINUE); } static int zio_write_bp_init(zio_t *zio) { if (!IO_IS_ALLOCATING(zio)) return (ZIO_PIPELINE_CONTINUE); 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_PIPELINE_CONTINUE); /* * 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_PIPELINE_CONTINUE); } ASSERT(!zp->zp_nopwrite); if (BP_IS_HOLE(bp) || !zp->zp_dedup) return (ZIO_PIPELINE_CONTINUE); ASSERT((zio_checksum_table[zp->zp_checksum].ci_flags & ZCHECKSUM_FLAG_DEDUP) || zp->zp_dedup_verify); if (BP_GET_CHECKSUM(bp) == zp->zp_checksum) { BP_SET_DEDUP(bp, 1); zio->io_pipeline |= ZIO_STAGE_DDT_WRITE; return (ZIO_PIPELINE_CONTINUE); } /* * 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_PIPELINE_CONTINUE); } static int 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; EQUIV(lsize != psize, (zio->io_flags & ZIO_FLAG_RAW) != 0); /* * 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_GANG, ZIO_WAIT_READY) || zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_READY)) return (ZIO_PIPELINE_STOP); if (!IO_IS_ALLOCATING(zio)) return (ZIO_PIPELINE_CONTINUE); 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 && psize == lsize) { void *cbuf = zio_buf_alloc(lsize); psize = zio_compress_data(compress, zio->io_abd, cbuf, lsize); if (psize == 0 || psize == lsize) { compress = ZIO_COMPRESS_OFF; zio_buf_free(cbuf, lsize); } else if (!zp->zp_dedup && 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_PIPELINE_CONTINUE); } else { /* * Round up compressed size up to the ashift * 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_ashift, >=, SPA_MINBLOCKSHIFT); size_t rounded = (size_t)P2ROUNDUP(psize, 1ULL << spa->spa_min_ashift); 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 { 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) { ASSERT(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)); 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_PIPELINE_CONTINUE); } static int 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; } return (ZIO_PIPELINE_CONTINUE); } /* * ========================================================================== * 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); ASSERT(q == ZIO_TASKQ_ISSUE || q == ZIO_TASKQ_INTERRUPT); /* * 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 && 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. */ #if defined(illumos) || !defined(_KERNEL) ASSERT(zio->io_tqent.tqent_next == NULL); #else ASSERT(zio->io_tqent.tqent_task.ta_pending == 0); #endif 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) { kthread_t *executor = zio->io_executor; spa_t *spa = zio->io_spa; 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 (taskq_member(tqs->stqs_taskq[i], executor)) return (B_TRUE); } } return (B_FALSE); } static int zio_issue_async(zio_t *zio) { zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); return (ZIO_PIPELINE_STOP); } 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 { hrtime_t diff = zio->io_target_timestamp - now; DTRACE_PROBE3(zio__delay__hit, zio_t *, zio, hrtime_t, now, hrtime_t, diff); (void) timeout_generic(CALLOUT_NORMAL, (void (*)(void *))zio_interrupt, zio, diff, 1, 0); } return; } #endif DTRACE_PROBE1(zio__delay__skip, zio_t *, zio); zio_interrupt(zio); } /* * 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(). * * 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[]; void zio_execute(zio_t *zio) { zio->io_executor = curthread; 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; int rv; 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; } zio->io_stage = stage; zio->io_pipeline_trace |= zio->io_stage; rv = zio_pipeline[highbit64(stage) - 1](zio); if (rv == ZIO_PIPELINE_STOP) return; ASSERT(rv == ZIO_PIPELINE_CONTINUE); } } /* * ========================================================================== * Initiate I/O, either sync or async * ========================================================================== */ int zio_wait(zio_t *zio) { int error; ASSERT(zio->io_stage == ZIO_STAGE_OPEN); ASSERT(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) cv_wait(&zio->io_cv, &zio->io_lock); mutex_exit(&zio->io_lock); error = zio->io_error; zio_destroy(zio); return (error); } void zio_nowait(zio_t *zio) { ASSERT(zio->io_executor == NULL); if (zio->io_child_type == ZIO_CHILD_LOGICAL && zio_unique_parent(zio) == NULL) { /* * 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; zio_add_child(spa->spa_async_zio_root[CPU_SEQID], zio); } ASSERT0(zio->io_queued_timestamp); zio->io_queued_timestamp = gethrtime(); zio_execute(zio); } /* * ========================================================================== * Reexecute 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; for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) { cio_next = zio_walk_children(pio, &zl); mutex_enter(&pio->io_lock); 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); } /* * 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 him. */ if (!(pio->io_flags & ZIO_FLAG_GODFATHER)) { pio->io_queued_timestamp = gethrtime(); zio_execute(pio); } } void zio_suspend(spa_t *spa, zio_t *zio) { 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)); zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL, NULL, 0, 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 = B_TRUE; 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 = B_FALSE; 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); } 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); } /* * 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) { return (zio_free_sync(pio, pio->io_spa, pio->io_txg, bp, BP_IS_GANG(bp) ? SPA_GANGBLOCKSIZE : BP_GET_PSIZE(bp), ZIO_GANG_CHILD_FLAGS(pio))); } /* 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); 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 && gio->io_abd != NULL) ASSERT3U(gio->io_size, ==, offset); if (zio != pio) zio_nowait(zio); } static int 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_PIPELINE_CONTINUE); } static int zio_gang_issue(zio_t *zio) { blkptr_t *bp = zio->io_bp; if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE)) return (ZIO_PIPELINE_STOP); 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_PIPELINE_CONTINUE); } static void zio_write_gang_member_ready(zio_t *zio) { zio_t *pio = zio_unique_parent(zio); zio_t *gio = zio->io_gang_leader; dva_t *cdva = zio->io_bp->blk_dva; dva_t *pdva = pio->io_bp->blk_dva; uint64_t asize; 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) { abd_put(zio->io_abd); } static int 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 = MIN(copies + 1, spa_max_replication(spa)); zio_prop_t zp; int error; 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(!(pio->io_flags & ZIO_FLAG_NODATA)); flags |= METASLAB_ASYNC_ALLOC; VERIFY(refcount_held(&mc->mc_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, flags)); } error = metaslab_alloc(spa, mc, SPA_GANGBLOCKSIZE, bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp, flags, &pio->io_alloc_list, pio); if (error) { if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) { ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); ASSERT(!(pio->io_flags & ZIO_FLAG_NODATA)); /* * 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); } pio->io_error = error; return (ZIO_PIPELINE_CONTINUE); } 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_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; zio_t *cio = zio_write(zio, spa, txg, &gbh->zg_blkptr[g], abd_get_offset(pio->io_abd, pio->io_size - resid), 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(!(pio->io_flags & ZIO_FLAG_NODATA)); /* * 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, flags)); } zio_nowait(cio); } /* * Set pio's pipeline to just wait for zio to finish. */ pio->io_pipeline = ZIO_INTERLOCK_PIPELINE; zio_nowait(zio); return (ZIO_PIPELINE_CONTINUE); } /* * 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 int 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_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_PIPELINE_CONTINUE); /* * 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); *bp = *bp_orig; zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; zio->io_flags |= ZIO_FLAG_NOPWRITE; } return (ZIO_PIPELINE_CONTINUE); } /* * ========================================================================== * 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 int 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_PIPELINE_CONTINUE); 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_PIPELINE_CONTINUE); } 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_PIPELINE_CONTINUE); } static int zio_ddt_read_done(zio_t *zio) { blkptr_t *bp = zio->io_bp; if (zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE)) return (ZIO_PIPELINE_STOP); 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_PIPELINE_CONTINUE); } if (dde == NULL) { zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1; zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); return (ZIO_PIPELINE_STOP); } 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_PIPELINE_CONTINUE); } 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); /* We should never get a raw, override zio */ 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. */ for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { zio_t *lio = dde->dde_lead_zio[p]; if (lio != NULL) { return (lio->io_orig_size != zio->io_orig_size || abd_cmp(zio->io_orig_abd, lio->io_orig_abd, zio->io_orig_size) != 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) { arc_buf_t *abuf = NULL; arc_flags_t aflags = ARC_FLAG_WAIT; int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE; blkptr_t blk = *zio->io_bp; int error; ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth); ddt_exit(ddt); /* * Intuitively, it would make more sense to compare * io_abd than io_orig_abd in the raw case since you * don't want to look at any transformations that have * happened to the data. However, for raw I/Os the * data will actually be the same in io_abd and * io_orig_abd, so all we have to do is issue this as * a raw ARC read. */ if (do_raw) { zio_flags |= ZIO_FLAG_RAW; ASSERT3U(zio->io_size, ==, zio->io_orig_size); ASSERT0(abd_cmp(zio->io_abd, zio->io_orig_abd, zio->io_size)); ASSERT3P(zio->io_transform_stack, ==, NULL); } error = arc_read(NULL, spa, &blk, arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zio->io_bookmark); if (error == 0) { if (arc_buf_size(abuf) != zio->io_orig_size || abd_cmp_buf(zio->io_orig_abd, abuf->b_data, zio->io_orig_size) != 0) error = SET_ERROR(EEXIST); 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 void zio_ddt_ditto_write_done(zio_t *zio) { int p = DDT_PHYS_DITTO; zio_prop_t *zp = &zio->io_prop; blkptr_t *bp = zio->io_bp; ddt_t *ddt = ddt_select(zio->io_spa, bp); ddt_entry_t *dde = zio->io_private; ddt_phys_t *ddp = &dde->dde_phys[p]; ddt_key_t *ddk = &dde->dde_key; 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) { ASSERT(ZIO_CHECKSUM_EQUAL(bp->blk_cksum, ddk->ddk_cksum)); ASSERT(zp->zp_copies < SPA_DVAS_PER_BP); ASSERT(zp->zp_copies == BP_GET_NDVAS(bp) - BP_IS_GANG(bp)); if (ddp->ddp_phys_birth != 0) ddt_phys_free(ddt, ddk, ddp, zio->io_txg); ddt_phys_fill(ddp, bp); } ddt_exit(ddt); } static int 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; int ditto_copies; zio_t *cio = NULL; zio_t *dio = 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_PIPELINE_CONTINUE); } ditto_copies = ddt_ditto_copies_needed(ddt, dde, ddp); ASSERT(ditto_copies < SPA_DVAS_PER_BP); if (ditto_copies > ddt_ditto_copies_present(dde) && dde->dde_lead_zio[DDT_PHYS_DITTO] == NULL) { zio_prop_t czp = *zp; czp.zp_copies = ditto_copies; /* * If we arrived here with an override bp, we won't have run * the transform stack, so we won't have the data we need to * generate a child i/o. So, toss the override bp and restart. * This is safe, because using the override bp is just an * optimization; and it's rare, so the cost doesn't matter. */ if (zio->io_bp_override) { zio_pop_transforms(zio); zio->io_stage = ZIO_STAGE_OPEN; zio->io_pipeline = ZIO_WRITE_PIPELINE; zio->io_bp_override = NULL; BP_ZERO(bp); ddt_exit(ddt); return (ZIO_PIPELINE_CONTINUE); } dio = zio_write(zio, spa, txg, bp, zio->io_orig_abd, zio->io_orig_size, zio->io_orig_size, &czp, NULL, NULL, NULL, zio_ddt_ditto_write_done, dde, zio->io_priority, ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); zio_push_transform(dio, zio->io_abd, zio->io_size, 0, NULL); dde->dde_lead_zio[DDT_PHYS_DITTO] = dio; } 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); if (cio) zio_nowait(cio); if (dio) zio_nowait(dio); return (ZIO_PIPELINE_CONTINUE); } ddt_entry_t *freedde; /* for debugging */ static int 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); ddp = ddt_phys_select(dde, bp); ddt_phys_decref(ddp); ddt_exit(ddt); return (ZIO_PIPELINE_CONTINUE); } /* * ========================================================================== * Allocate and free blocks * ========================================================================== */ static zio_t * zio_io_to_allocate(spa_t *spa) { zio_t *zio; ASSERT(MUTEX_HELD(&spa->spa_alloc_lock)); zio = avl_first(&spa->spa_alloc_tree); 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. */ if (!metaslab_class_throttle_reserve(spa_normal_class(spa), zio->io_prop.zp_copies, zio, 0)) { return (NULL); } avl_remove(&spa->spa_alloc_tree, zio); ASSERT3U(zio->io_stage, <, ZIO_STAGE_DVA_ALLOCATE); return (zio); } static int zio_dva_throttle(zio_t *zio) { spa_t *spa = zio->io_spa; zio_t *nio; if (zio->io_priority == ZIO_PRIORITY_SYNC_WRITE || !spa_normal_class(zio->io_spa)->mc_alloc_throttle_enabled || zio->io_child_type == ZIO_CHILD_GANG || zio->io_flags & ZIO_FLAG_NODATA) { return (ZIO_PIPELINE_CONTINUE); } ASSERT(zio->io_child_type > ZIO_CHILD_GANG); ASSERT3U(zio->io_queued_timestamp, >, 0); ASSERT(zio->io_stage == ZIO_STAGE_DVA_THROTTLE); mutex_enter(&spa->spa_alloc_lock); ASSERT(zio->io_type == ZIO_TYPE_WRITE); avl_add(&spa->spa_alloc_tree, zio); nio = zio_io_to_allocate(zio->io_spa); mutex_exit(&spa->spa_alloc_lock); if (nio == zio) return (ZIO_PIPELINE_CONTINUE); if (nio != NULL) { ASSERT(nio->io_stage == ZIO_STAGE_DVA_THROTTLE); /* * We are passing control to a new zio so make sure that * it is processed by a different thread. We do this to * avoid stack overflows that can occur when parents are * throttled and children are making progress. We allow * it to go to the head of the taskq since it's already * been waiting. */ zio_taskq_dispatch(nio, ZIO_TASKQ_ISSUE, B_TRUE); } return (ZIO_PIPELINE_STOP); } void zio_allocate_dispatch(spa_t *spa) { zio_t *zio; mutex_enter(&spa->spa_alloc_lock); zio = zio_io_to_allocate(spa); mutex_exit(&spa->spa_alloc_lock); 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 int zio_dva_allocate(zio_t *zio) { spa_t *spa = zio->io_spa; metaslab_class_t *mc = spa_normal_class(spa); 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)); 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; } error = metaslab_alloc(spa, mc, zio->io_size, bp, zio->io_prop.zp_copies, zio->io_txg, NULL, flags, &zio->io_alloc_list, zio); if (error != 0) { spa_dbgmsg(spa, "%s: metaslab allocation failure: zio %p, " "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_PIPELINE_CONTINUE); } static int zio_dva_free(zio_t *zio) { metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE); return (ZIO_PIPELINE_CONTINUE); } static int 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_PIPELINE_CONTINUE); } /* * 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, uint64_t txg, blkptr_t *new_bp, blkptr_t *old_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); error = metaslab_alloc(spa, spa_log_class(spa), size, new_bp, 1, txg, old_bp, METASLAB_HINTBP_AVOID, &io_alloc_list, NULL); if (error == 0) { *slog = TRUE; } else { error = metaslab_alloc(spa, spa_normal_class(spa), size, new_bp, 1, txg, old_bp, METASLAB_HINTBP_AVOID, &io_alloc_list, NULL); 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); } return (error); } /* * Free an intent log block. */ void zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp) { ASSERT(BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG); ASSERT(!BP_IS_GANG(bp)); zio_free(spa, txg, bp); } /* * ========================================================================== * Read, write and delete 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 int zio_vdev_io_start(zio_t *zio) { vdev_t *vd = zio->io_vd; uint64_t align; spa_t *spa = zio->io_spa; int ret; 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 (ZIO_PIPELINE_STOP); } if (vd->vdev_ops->vdev_op_leaf && zio->io_type == ZIO_TYPE_FREE && zio->io_priority == ZIO_PRIORITY_NOW) { trim_map_free(vd, zio->io_offset, zio->io_size, zio->io_txg); return (ZIO_PIPELINE_CONTINUE); } ASSERT3P(zio->io_logical, !=, zio); /* * We keep track of time-sensitive I/Os so that the scan thread * can quickly react to certain workloads. In particular, we care * about non-scrubbing, top-level reads and writes with the following * characteristics: * - synchronous writes of user data to non-slog devices * - any reads of user data * When these conditions are met, adjust the timestamp of spa_last_io * which allows the scan thread to adjust its workload accordingly. */ if (!(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && zio->io_bp != NULL && vd == vd->vdev_top && !vd->vdev_islog && zio->io_bookmark.zb_objset != DMU_META_OBJSET && zio->io_txg != spa_syncing_txg(spa)) { uint64_t old = spa->spa_last_io; uint64_t new = ddi_get_lbolt64(); if (old != new) (void) atomic_cas_64(&spa->spa_last_io, old, new); } 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_t *abuf = NULL; if (zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE) 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, abuf ? asize : 0, 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 the physical io we allow alignment * to a logical block size. */ uint64_t log_align = 1ULL << vd->vdev_top->vdev_logical_ashift; ASSERT0(P2PHASE(zio->io_offset, log_align)); ASSERT0(P2PHASE(zio->io_size, log_align)); } VERIFY(zio->io_type == ZIO_TYPE_READ || 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 with nested replication. * For example, given a mirror of mirrors, (A+B)+(C+D), if only * A is out of date, we'll read from C+D, 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. * The same logic applies to any form of nested replication: * ditto + mirror, RAID-Z + replacing, etc. This covers them all. */ if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) && !(zio->io_flags & ZIO_FLAG_SELF_HEAL) && zio->io_txg != 0 && /* not a delegated i/o */ !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) { ASSERT(zio->io_type == ZIO_TYPE_WRITE); zio_vdev_io_bypass(zio); return (ZIO_PIPELINE_CONTINUE); } if (vd->vdev_ops->vdev_op_leaf) { switch (zio->io_type) { case ZIO_TYPE_READ: if (vdev_cache_read(zio)) return (ZIO_PIPELINE_CONTINUE); /* FALLTHROUGH */ case ZIO_TYPE_WRITE: case ZIO_TYPE_FREE: if ((zio = vdev_queue_io(zio)) == NULL) return (ZIO_PIPELINE_STOP); if (!vdev_accessible(vd, zio)) { zio->io_error = SET_ERROR(ENXIO); zio_interrupt(zio); return (ZIO_PIPELINE_STOP); } break; } /* * Note that we ignore repair writes for TRIM because they can * conflict with normal writes. This isn't an issue because, by * definition, we only repair blocks that aren't freed. */ if (zio->io_type == ZIO_TYPE_WRITE && !(zio->io_flags & ZIO_FLAG_IO_REPAIR) && !trim_map_write_start(zio)) return (ZIO_PIPELINE_STOP); } vd->vdev_ops->vdev_op_io_start(zio); return (ZIO_PIPELINE_STOP); } static int 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, ZIO_WAIT_DONE)) return (ZIO_PIPELINE_STOP); ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE || zio->io_type == ZIO_TYPE_FREE); if (vd != NULL && vd->vdev_ops->vdev_op_leaf && (zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE || zio->io_type == ZIO_TYPE_FREE)) { if (zio->io_type == ZIO_TYPE_WRITE && !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) trim_map_write_done(zio); 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_injection(vd, zio, EIO); if (zio_injection_enabled && zio->io_error == 0) zio->io_error = zio_handle_label_injection(zio, EIO); if (zio->io_error) { if (zio->io_error == ENOTSUP && zio->io_type == ZIO_TYPE_FREE) { /* Not all devices support TRIM. */ } else 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_PIPELINE_CONTINUE); } /* * 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 void *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 *buf = zio_buf_alloc(zio->io_size); abd_copy_to_buf(buf, zio->io_abd, zio->io_size); zcr->zcr_cbinfo = zio->io_size; zcr->zcr_cbdata = buf; zcr->zcr_finish = zio_vsd_default_cksum_finish; zcr->zcr_free = zio_buf_free; } static int zio_vdev_io_assess(zio_t *zio) { vdev_t *vd = zio->io_vd; if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) return (ZIO_PIPELINE_STOP); 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 (zio->io_type == ZIO_TYPE_FREE && zio->io_priority != ZIO_PRIORITY_NOW) { switch (zio->io_error) { case 0: ZIO_TRIM_STAT_INCR(bytes, zio->io_size); ZIO_TRIM_STAT_BUMP(success); break; case EOPNOTSUPP: ZIO_TRIM_STAT_BUMP(unsupported); break; default: ZIO_TRIM_STAT_BUMP(failed); break; } } /* * 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 (ZIO_PIPELINE_STOP); } /* * 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 bit 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_PIPELINE_CONTINUE); } 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; } /* * ========================================================================== * Generate and verify checksums * ========================================================================== */ static int 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_PIPELINE_CONTINUE); 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_PIPELINE_CONTINUE); } static int 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_PIPELINE_CONTINUE); ASSERT(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)) { zfs_ereport_start_checksum(zio->io_spa, zio->io_vd, zio, zio->io_offset, zio->io_size, NULL, &info); } } return (ZIO_PIPELINE_CONTINUE); } /* * 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 permament. 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 int 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, ZIO_WAIT_READY) || zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_READY)) return (ZIO_PIPELINE_STOP); 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); /* * We were unable to allocate anything, unreserve and * issue the next I/O to allocate. */ metaslab_class_throttle_unreserve( spa_normal_class(zio->io_spa), zio->io_prop.zp_copies, zio); zio_allocate_dispatch(zio->io_spa); } } 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); } 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_PIPELINE_CONTINUE); } /* * Update the allocation throttle accounting. */ static void zio_dva_throttle_done(zio_t *zio) { zio_t *lio = 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->io_flags & (ZIO_FLAG_IO_REPAIR | ZIO_FLAG_IO_RETRY))); 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); mutex_enter(&pio->io_lock); metaslab_group_alloc_decrement(zio->io_spa, vd->vdev_id, pio, flags); mutex_exit(&pio->io_lock); metaslab_class_throttle_unreserve(spa_normal_class(zio->io_spa), 1, 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); } static int zio_done(zio_t *zio) { spa_t *spa = zio->io_spa; zio_t *lio = zio->io_logical; blkptr_t *bp = zio->io_bp; vdev_t *vd = zio->io_vd; uint64_t psize = zio->io_size; zio_t *pio, *pio_next; metaslab_class_t *mc = spa_normal_class(spa); 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_VDEV, ZIO_WAIT_DONE) || zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE) || zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE) || zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_DONE)) return (ZIO_PIPELINE_STOP); /* * 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(mc->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(bp != NULL); metaslab_group_alloc_verify(spa, zio->io_bp, zio); VERIFY(refcount_not_held(&mc->mc_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 (bp != NULL && !BP_IS_EMBEDDED(bp)) { ASSERT(bp->blk_pad[0] == 0); ASSERT(bp->blk_pad[1] == 0); ASSERT(bcmp(bp, &zio->io_bp_copy, sizeof (blkptr_t)) == 0 || (bp == zio_unique_parent(zio)->io_bp)); if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(bp) && zio->io_bp_override == NULL && !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) { ASSERT(!BP_SHOULD_BYTESWAP(bp)); ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(bp)); ASSERT(BP_COUNT_GANG(bp) == 0 || (BP_COUNT_GANG(bp) == BP_GET_NDVAS(bp))); } if (zio->io_flags & ZIO_FLAG_NOPWRITE) VERIFY(BP_EQUAL(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); char *abuf = NULL; abd_t *adata = zio->io_abd; if (asize != psize) { adata = abd_alloc_linear(asize, B_TRUE); abd_copy(adata, zio->io_abd, psize); abd_zero_off(adata, psize, asize - psize); } if (adata != NULL) abuf = abd_borrow_buf_copy(adata, asize); zio->io_cksum_report = zcr->zcr_next; zcr->zcr_next = NULL; zcr->zcr_finish(zcr, abuf); zfs_ereport_free_checksum(zcr); if (adata != NULL) abd_return_buf(adata, abuf, asize); if (asize != psize) abd_free(adata); } } zio_pop_transforms(zio); /* note: may set zio->io_error */ vdev_stat_update(zio, psize); 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 && vd != NULL && !vdev_is_dead(vd)) zfs_ereport_post(FM_EREPORT_ZFS_IO, spa, vd, zio, 0, 0); if ((zio->io_error == EIO || !(zio->io_flags & (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) && zio == lio) { /* * For logical I/O requests, tell the SPA to log the * error and generate a logical data ereport. */ spa_log_error(spa, zio); zfs_ereport_post(FM_EREPORT_ZFS_DATA, spa, NULL, zio, 0, 0); } } if (zio->io_error && zio == lio) { /* * Determine whether zio should be reexecuted. This will * propagate all the way to the root via zio_notify_parent(). */ ASSERT(vd == NULL && 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(spa) == SPA_LOAD_NONE && spa_get_failmode(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, 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 = 0; 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); zio_notify_parent(pio, zio, ZIO_WAIT_DONE); } } 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; zio_notify_parent(pio, zio, ZIO_WAIT_DONE); } 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(spa, zio); } else { /* * Reexecution is potentially a huge amount of work. * Hand it off to the otherwise-unused claim taskq. */ #if defined(illumos) || !defined(_KERNEL) ASSERT(zio->io_tqent.tqent_next == NULL); #else ASSERT(zio->io_tqent.tqent_task.ta_pending == 0); #endif spa_taskq_dispatch_ent(spa, ZIO_TYPE_CLAIM, ZIO_TASKQ_ISSUE, (task_func_t *)zio_reexecute, zio, 0, &zio->io_tqent); } return (ZIO_PIPELINE_STOP); } 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); } /* * 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); 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); } 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 (ZIO_PIPELINE_STOP); } /* * ========================================================================== * 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_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); /* * 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); }