Index: head/sys/cddl/boot/zfs/zfssubr.c =================================================================== --- head/sys/cddl/boot/zfs/zfssubr.c (revision 304752) +++ head/sys/cddl/boot/zfs/zfssubr.c (revision 304753) @@ -1,1784 +1,1787 @@ /* * 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 2007 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ #include __FBSDID("$FreeBSD$"); static uint64_t zfs_crc64_table[256]; #define ECKSUM 666 #define ASSERT3S(x, y, z) ((void)0) #define ASSERT3U(x, y, z) ((void)0) #define ASSERT3P(x, y, z) ((void)0) #define ASSERT0(x) ((void)0) #define ASSERT(x) ((void)0) #define panic(...) do { \ printf(__VA_ARGS__); \ for (;;) ; \ } while (0) #define kmem_alloc(size, flag) zfs_alloc((size)) #define kmem_free(ptr, size) zfs_free((ptr), (size)) static void zfs_init_crc(void) { int i, j; uint64_t *ct; /* * Calculate the crc64 table (used for the zap hash * function). */ if (zfs_crc64_table[128] != ZFS_CRC64_POLY) { memset(zfs_crc64_table, 0, sizeof(zfs_crc64_table)); for (i = 0; i < 256; i++) for (ct = zfs_crc64_table + i, *ct = i, j = 8; j > 0; j--) *ct = (*ct >> 1) ^ (-(*ct & 1) & ZFS_CRC64_POLY); } } static void zio_checksum_off(const void *buf, uint64_t size, const void *ctx_template, zio_cksum_t *zcp) { ZIO_SET_CHECKSUM(zcp, 0, 0, 0, 0); } /* * Signature for checksum functions. */ typedef void zio_checksum_t(const void *data, uint64_t size, const void *ctx_template, zio_cksum_t *zcp); typedef void *zio_checksum_tmpl_init_t(const zio_cksum_salt_t *salt); typedef void zio_checksum_tmpl_free_t(void *ctx_template); typedef enum zio_checksum_flags { /* Strong enough for metadata? */ ZCHECKSUM_FLAG_METADATA = (1 << 1), /* ZIO embedded checksum */ ZCHECKSUM_FLAG_EMBEDDED = (1 << 2), /* Strong enough for dedup (without verification)? */ ZCHECKSUM_FLAG_DEDUP = (1 << 3), /* Uses salt value */ ZCHECKSUM_FLAG_SALTED = (1 << 4), /* Strong enough for nopwrite? */ ZCHECKSUM_FLAG_NOPWRITE = (1 << 5) } zio_checksum_flags_t; /* * Information about each checksum function. */ typedef struct zio_checksum_info { /* checksum function for each byteorder */ zio_checksum_t *ci_func[2]; zio_checksum_tmpl_init_t *ci_tmpl_init; zio_checksum_tmpl_free_t *ci_tmpl_free; zio_checksum_flags_t ci_flags; const char *ci_name; /* descriptive name */ } zio_checksum_info_t; #include "blkptr.c" #include "fletcher.c" #include "sha256.c" #include "skein_zfs.c" static zio_checksum_info_t zio_checksum_table[ZIO_CHECKSUM_FUNCTIONS] = { {{NULL, NULL}, NULL, NULL, 0, "inherit"}, {{NULL, NULL}, NULL, NULL, 0, "on"}, {{zio_checksum_off, zio_checksum_off}, NULL, NULL, 0, "off"}, {{zio_checksum_SHA256, zio_checksum_SHA256}, NULL, NULL, ZCHECKSUM_FLAG_METADATA | ZCHECKSUM_FLAG_EMBEDDED, "label"}, {{zio_checksum_SHA256, zio_checksum_SHA256}, NULL, NULL, ZCHECKSUM_FLAG_METADATA | ZCHECKSUM_FLAG_EMBEDDED, "gang_header"}, {{fletcher_2_native, fletcher_2_byteswap}, NULL, NULL, ZCHECKSUM_FLAG_EMBEDDED, "zilog"}, {{fletcher_2_native, fletcher_2_byteswap}, NULL, NULL, 0, "fletcher2"}, {{fletcher_4_native, fletcher_4_byteswap}, NULL, NULL, ZCHECKSUM_FLAG_METADATA, "fletcher4"}, {{zio_checksum_SHA256, zio_checksum_SHA256}, NULL, NULL, ZCHECKSUM_FLAG_METADATA | ZCHECKSUM_FLAG_DEDUP | ZCHECKSUM_FLAG_NOPWRITE, "SHA256"}, {{fletcher_4_native, fletcher_4_byteswap}, NULL, NULL, ZCHECKSUM_FLAG_EMBEDDED, "zillog2"}, {{zio_checksum_off, zio_checksum_off}, NULL, NULL, 0, "noparity"}, {{zio_checksum_SHA512_native, zio_checksum_SHA512_byteswap}, NULL, NULL, ZCHECKSUM_FLAG_METADATA | ZCHECKSUM_FLAG_DEDUP | ZCHECKSUM_FLAG_NOPWRITE, "SHA512"}, {{zio_checksum_skein_native, zio_checksum_skein_byteswap}, zio_checksum_skein_tmpl_init, zio_checksum_skein_tmpl_free, ZCHECKSUM_FLAG_METADATA | ZCHECKSUM_FLAG_DEDUP | ZCHECKSUM_FLAG_SALTED | ZCHECKSUM_FLAG_NOPWRITE, "skein"}, /* no edonr for now */ {{NULL, NULL}, NULL, NULL, ZCHECKSUM_FLAG_METADATA | ZCHECKSUM_FLAG_SALTED | ZCHECKSUM_FLAG_NOPWRITE, "edonr"} }; /* * Common signature for all zio compress/decompress functions. */ typedef size_t zio_compress_func_t(void *src, void *dst, size_t s_len, size_t d_len, int); typedef int zio_decompress_func_t(void *src, void *dst, size_t s_len, size_t d_len, int); /* * Information about each compression function. */ typedef struct zio_compress_info { zio_compress_func_t *ci_compress; /* compression function */ zio_decompress_func_t *ci_decompress; /* decompression function */ int ci_level; /* level parameter */ const char *ci_name; /* algorithm name */ } zio_compress_info_t; #include "lzjb.c" #include "zle.c" #include "lz4.c" /* * Compression vectors. */ static zio_compress_info_t zio_compress_table[ZIO_COMPRESS_FUNCTIONS] = { {NULL, NULL, 0, "inherit"}, {NULL, NULL, 0, "on"}, {NULL, NULL, 0, "uncompressed"}, {NULL, lzjb_decompress, 0, "lzjb"}, {NULL, NULL, 0, "empty"}, {NULL, NULL, 1, "gzip-1"}, {NULL, NULL, 2, "gzip-2"}, {NULL, NULL, 3, "gzip-3"}, {NULL, NULL, 4, "gzip-4"}, {NULL, NULL, 5, "gzip-5"}, {NULL, NULL, 6, "gzip-6"}, {NULL, NULL, 7, "gzip-7"}, {NULL, NULL, 8, "gzip-8"}, {NULL, NULL, 9, "gzip-9"}, {NULL, zle_decompress, 64, "zle"}, {NULL, lz4_decompress, 0, "lz4"}, }; static void byteswap_uint64_array(void *vbuf, size_t size) { uint64_t *buf = vbuf; size_t count = size >> 3; int i; ASSERT((size & 7) == 0); for (i = 0; i < count; i++) buf[i] = BSWAP_64(buf[i]); } /* * Set the external verifier for a gang block based on , * a tuple which is guaranteed to be unique for the life of the pool. */ static void zio_checksum_gang_verifier(zio_cksum_t *zcp, const blkptr_t *bp) { const dva_t *dva = BP_IDENTITY(bp); uint64_t txg = BP_PHYSICAL_BIRTH(bp); ASSERT(BP_IS_GANG(bp)); ZIO_SET_CHECKSUM(zcp, DVA_GET_VDEV(dva), DVA_GET_OFFSET(dva), txg, 0); } /* * Set the external verifier for a label block based on its offset. * The vdev is implicit, and the txg is unknowable at pool open time -- * hence the logic in vdev_uberblock_load() to find the most recent copy. */ static void zio_checksum_label_verifier(zio_cksum_t *zcp, uint64_t offset) { ZIO_SET_CHECKSUM(zcp, offset, 0, 0, 0); } /* * Calls the template init function of a checksum which supports context * templates and installs the template into the spa_t. */ static void zio_checksum_template_init(enum zio_checksum checksum, spa_t *spa) { zio_checksum_info_t *ci = &zio_checksum_table[checksum]; if (ci->ci_tmpl_init == NULL) return; if (spa->spa_cksum_tmpls[checksum] != NULL) return; if (spa->spa_cksum_tmpls[checksum] == NULL) { spa->spa_cksum_tmpls[checksum] = ci->ci_tmpl_init(&spa->spa_cksum_salt); } } /* * Called by a spa_t that's about to be deallocated. This steps through * all of the checksum context templates and deallocates any that were * initialized using the algorithm-specific template init function. */ void zio_checksum_templates_free(spa_t *spa) { for (enum zio_checksum checksum = 0; checksum < ZIO_CHECKSUM_FUNCTIONS; checksum++) { if (spa->spa_cksum_tmpls[checksum] != NULL) { zio_checksum_info_t *ci = &zio_checksum_table[checksum]; ci->ci_tmpl_free(spa->spa_cksum_tmpls[checksum]); spa->spa_cksum_tmpls[checksum] = NULL; } } } static int zio_checksum_verify(const spa_t *spa, const blkptr_t *bp, void *data) { uint64_t size; unsigned int checksum; zio_checksum_info_t *ci; + void *ctx = NULL; zio_cksum_t actual_cksum, expected_cksum, verifier; int byteswap; checksum = BP_GET_CHECKSUM(bp); size = BP_GET_PSIZE(bp); if (checksum >= ZIO_CHECKSUM_FUNCTIONS) return (EINVAL); ci = &zio_checksum_table[checksum]; if (ci->ci_func[0] == NULL || ci->ci_func[1] == NULL) return (EINVAL); - zio_checksum_template_init(checksum, (spa_t *) spa); + if (spa != NULL) { + zio_checksum_template_init(checksum, (spa_t *) spa); + ctx = spa->spa_cksum_tmpls[checksum]; + } + if (ci->ci_flags & ZCHECKSUM_FLAG_EMBEDDED) { zio_eck_t *eck; ASSERT(checksum == ZIO_CHECKSUM_GANG_HEADER || checksum == ZIO_CHECKSUM_LABEL); eck = (zio_eck_t *)((char *)data + size) - 1; if (checksum == ZIO_CHECKSUM_GANG_HEADER) zio_checksum_gang_verifier(&verifier, bp); else if (checksum == ZIO_CHECKSUM_LABEL) zio_checksum_label_verifier(&verifier, DVA_GET_OFFSET(BP_IDENTITY(bp))); else verifier = bp->blk_cksum; byteswap = (eck->zec_magic == BSWAP_64(ZEC_MAGIC)); if (byteswap) byteswap_uint64_array(&verifier, sizeof (zio_cksum_t)); expected_cksum = eck->zec_cksum; eck->zec_cksum = verifier; - ci->ci_func[byteswap](data, size, - spa->spa_cksum_tmpls[checksum], &actual_cksum); + ci->ci_func[byteswap](data, size, ctx, &actual_cksum); eck->zec_cksum = expected_cksum; if (byteswap) byteswap_uint64_array(&expected_cksum, sizeof (zio_cksum_t)); } else { expected_cksum = bp->blk_cksum; - ci->ci_func[0](data, size, spa->spa_cksum_tmpls[checksum], - &actual_cksum); + ci->ci_func[0](data, size, ctx, &actual_cksum); } if (!ZIO_CHECKSUM_EQUAL(actual_cksum, expected_cksum)) { /*printf("ZFS: read checksum %s failed\n", ci->ci_name);*/ return (EIO); } return (0); } static int zio_decompress_data(int cpfunc, void *src, uint64_t srcsize, void *dest, uint64_t destsize) { zio_compress_info_t *ci; if (cpfunc >= ZIO_COMPRESS_FUNCTIONS) { printf("ZFS: unsupported compression algorithm %u\n", cpfunc); return (EIO); } ci = &zio_compress_table[cpfunc]; if (!ci->ci_decompress) { printf("ZFS: unsupported compression algorithm %s\n", ci->ci_name); return (EIO); } return (ci->ci_decompress(src, dest, srcsize, destsize, ci->ci_level)); } static uint64_t zap_hash(uint64_t salt, const char *name) { const uint8_t *cp; uint8_t c; uint64_t crc = salt; ASSERT(crc != 0); ASSERT(zfs_crc64_table[128] == ZFS_CRC64_POLY); for (cp = (const uint8_t *)name; (c = *cp) != '\0'; cp++) crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ c) & 0xFF]; /* * Only use 28 bits, since we need 4 bits in the cookie for the * collision differentiator. We MUST use the high bits, since * those are the onces that we first pay attention to when * chosing the bucket. */ crc &= ~((1ULL << (64 - ZAP_HASHBITS)) - 1); return (crc); } static void *zfs_alloc(size_t size); static void zfs_free(void *ptr, size_t size); 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 */ void *rc_data; /* I/O data */ 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 */ 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) & 0x1d1d1d1d1d1d1d1dULL); \ } #define VDEV_RAIDZ_64MUL_4(x, mask) \ { \ VDEV_RAIDZ_64MUL_2((x), mask); \ VDEV_RAIDZ_64MUL_2((x), mask); \ } /* * These two tables represent powers and logs of 2 in the Galois field defined * above. These values were computed by repeatedly multiplying by 2 as 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 }; 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, }; /* * Multiply a given number by 2 raised to the given power. */ static uint8_t vdev_raidz_exp2(uint8_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_generate_parity_p(raidz_map_t *rm) { uint64_t *p, *src, pcount, ccount, i; int c; pcount = rm->rm_col[VDEV_RAIDZ_P].rc_size / sizeof (src[0]); for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) { src = rm->rm_col[c].rc_data; p = rm->rm_col[VDEV_RAIDZ_P].rc_data; ccount = rm->rm_col[c].rc_size / sizeof (src[0]); if (c == rm->rm_firstdatacol) { ASSERT(ccount == pcount); for (i = 0; i < ccount; i++, src++, p++) { *p = *src; } } else { ASSERT(ccount <= pcount); for (i = 0; i < ccount; i++, src++, p++) { *p ^= *src; } } } } static void vdev_raidz_generate_parity_pq(raidz_map_t *rm) { uint64_t *p, *q, *src, pcnt, ccnt, mask, i; int c; pcnt = rm->rm_col[VDEV_RAIDZ_P].rc_size / sizeof (src[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_data; p = rm->rm_col[VDEV_RAIDZ_P].rc_data; q = rm->rm_col[VDEV_RAIDZ_Q].rc_data; ccnt = rm->rm_col[c].rc_size / sizeof (src[0]); if (c == rm->rm_firstdatacol) { ASSERT(ccnt == pcnt || ccnt == 0); for (i = 0; i < ccnt; i++, src++, p++, q++) { *p = *src; *q = *src; } for (; i < pcnt; i++, src++, p++, q++) { *p = 0; *q = 0; } } else { ASSERT(ccnt <= pcnt); /* * Apply the algorithm described above by multiplying * the previous result and adding in the new value. */ for (i = 0; i < ccnt; i++, src++, p++, q++) { *p ^= *src; VDEV_RAIDZ_64MUL_2(*q, mask); *q ^= *src; } /* * Treat short columns as though they are full of 0s. * Note that there's therefore nothing needed for P. */ for (; i < pcnt; i++, q++) { VDEV_RAIDZ_64MUL_2(*q, mask); } } } } static void vdev_raidz_generate_parity_pqr(raidz_map_t *rm) { uint64_t *p, *q, *r, *src, pcnt, ccnt, mask, i; int c; pcnt = rm->rm_col[VDEV_RAIDZ_P].rc_size / sizeof (src[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_data; p = rm->rm_col[VDEV_RAIDZ_P].rc_data; q = rm->rm_col[VDEV_RAIDZ_Q].rc_data; r = rm->rm_col[VDEV_RAIDZ_R].rc_data; ccnt = rm->rm_col[c].rc_size / sizeof (src[0]); if (c == rm->rm_firstdatacol) { ASSERT(ccnt == pcnt || ccnt == 0); for (i = 0; i < ccnt; i++, src++, p++, q++, r++) { *p = *src; *q = *src; *r = *src; } for (; i < pcnt; i++, src++, p++, q++, r++) { *p = 0; *q = 0; *r = 0; } } else { ASSERT(ccnt <= pcnt); /* * Apply the algorithm described above by multiplying * the previous result and adding in the new value. */ for (i = 0; i < ccnt; i++, src++, p++, q++, r++) { *p ^= *src; VDEV_RAIDZ_64MUL_2(*q, mask); *q ^= *src; VDEV_RAIDZ_64MUL_4(*r, mask); *r ^= *src; } /* * Treat short columns as though they are full of 0s. * Note that there's therefore nothing needed for P. */ for (; i < pcnt; i++, q++, r++) { VDEV_RAIDZ_64MUL_2(*q, mask); VDEV_RAIDZ_64MUL_4(*r, 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: panic("invalid RAID-Z configuration"); } } /* 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 | * | 128 64 32 16 8 4 2 1 | * | 19 205 116 29 64 16 4 1 | * | 1 0 0 0 0 0 0 0 | * | 0 1 0 0 0 0 0 0 | * (V|I)' = | 0 0 1 0 0 0 0 0 | * | 0 0 0 1 0 0 0 0 | * | 0 0 0 0 1 0 0 0 | * | 0 0 0 0 0 1 0 0 | * | 0 0 0 0 0 0 1 0 | * | 0 0 0 0 0 0 0 1 | * ~~ ~~ * * Here we employ Gauss-Jordan elimination to find the inverse of (V|I)'. We * have carefully chosen the seed values 1, 2, and 4 to ensure that this * matrix is not singular. * __ __ * | 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 | * | 19 205 116 29 64 16 4 1 0 1 0 0 0 0 0 0 | * | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 | * | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 | * | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 | * | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 | * | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 | * | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 | * ~~ ~~ * __ __ * | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 | * | 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 | * | 19 205 116 29 64 16 4 1 0 1 0 0 0 0 0 0 | * | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 | * | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 | * | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 | * | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 | * | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 | * ~~ ~~ * __ __ * | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 | * | 0 1 1 0 0 0 0 0 1 0 1 1 1 1 1 1 | * | 0 205 116 0 0 0 0 0 0 1 19 29 64 16 4 1 | * | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 | * | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 | * | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 | * | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 | * | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 | * ~~ ~~ * __ __ * | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 | * | 0 1 1 0 0 0 0 0 1 0 1 1 1 1 1 1 | * | 0 0 185 0 0 0 0 0 205 1 222 208 141 221 201 204 | * | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 | * | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 | * | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 | * | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 | * | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 | * ~~ ~~ * __ __ * | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 | * | 0 1 1 0 0 0 0 0 1 0 1 1 1 1 1 1 | * | 0 0 1 0 0 0 0 0 166 100 4 40 158 168 216 209 | * | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 | * | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 | * | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 | * | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 | * | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 | * ~~ ~~ * __ __ * | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 | * | 0 1 0 0 0 0 0 0 167 100 5 41 159 169 217 208 | * | 0 0 1 0 0 0 0 0 166 100 4 40 158 168 216 209 | * | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 | * | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 | * | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 | * | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 | * | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 | * ~~ ~~ * __ __ * | 0 0 1 0 0 0 0 0 | * | 167 100 5 41 159 169 217 208 | * | 166 100 4 40 158 168 216 209 | * (V|I)'^-1 = | 0 0 0 1 0 0 0 0 | * | 0 0 0 0 1 0 0 0 | * | 0 0 0 0 0 1 0 0 | * | 0 0 0 0 0 0 1 0 | * | 0 0 0 0 0 0 0 1 | * ~~ ~~ * * We can then simply compute D = (V|I)'^-1 x (d|p)' to discover the values * of the missing data. * * As is apparent from the example above, the only non-trivial rows in the * inverse matrix correspond to the data disks that we're trying to * reconstruct. Indeed, those are the only rows we need as the others would * only be useful for reconstructing data known or assumed to be valid. For * that reason, we only build the coefficients in the rows that correspond to * targeted columns. */ /* END CSTYLED */ static void vdev_raidz_matrix_init(raidz_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++) { ASSERT3U(rows[i][j], ==, 0); } 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 { ASSERT3U(rows[i][j], ==, 0); } } } } 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, val; int ll; uint8_t *invlog[VDEV_RAIDZ_MAXPARITY]; uint8_t *p, *pp; size_t psize; log = 0; /* gcc */ psize = sizeof (invlog[0][0]) * n * nmissing; p = zfs_alloc(psize); 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 = rm->rm_col[c].rc_data; 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] = rm->rm_col[cc].rc_data; 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; } } } zfs_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; int code = 0; 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); return (code); } static int vdev_raidz_reconstruct(raidz_map_t *rm, int *t, int nt) { int tgts[VDEV_RAIDZ_MAXPARITY]; int ntgts; int i, c; int code; int nbadparity, nbaddata; /* * 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 (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 { nbadparity--; } } ASSERT(ntgts >= nt); ASSERT(nbaddata >= 0); ASSERT(nbaddata + nbadparity == ntgts); code = vdev_raidz_reconstruct_general(rm, tgts, ntgts); ASSERT(code < (1 << VDEV_RAIDZ_MAXPARITY)); ASSERT(code > 0); return (code); } static raidz_map_t * vdev_raidz_map_alloc(void *data, off_t offset, size_t size, uint64_t unit_shift, uint64_t dcols, uint64_t nparity) { raidz_map_t *rm; uint64_t b = offset >> unit_shift; uint64_t s = size >> unit_shift; uint64_t f = b % dcols; uint64_t o = (b / dcols) << unit_shift; uint64_t q, r, c, bc, col, acols, scols, coff, devidx, asize, tot; q = s / (dcols - nparity); r = s - q * (dcols - nparity); bc = (r == 0 ? 0 : r + nparity); tot = s + nparity * (q + (r == 0 ? 0 : 1)); if (q == 0) { acols = bc; scols = MIN(dcols, roundup(bc, nparity + 1)); } else { acols = dcols; scols = dcols; } ASSERT3U(acols, <=, scols); rm = zfs_alloc(offsetof(raidz_map_t, rm_col[scols])); 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_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_data = 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); for (c = 0; c < rm->rm_firstdatacol; c++) rm->rm_col[c].rc_data = zfs_alloc(rm->rm_col[c].rc_size); rm->rm_col[c].rc_data = data; for (c = c + 1; c < acols; c++) rm->rm_col[c].rc_data = (char *)rm->rm_col[c - 1].rc_data + rm->rm_col[c - 1].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); } static void vdev_raidz_map_free(raidz_map_t *rm) { int c; for (c = rm->rm_firstdatacol - 1; c >= 0; c--) zfs_free(rm->rm_col[c].rc_data, rm->rm_col[c].rc_size); zfs_free(rm, offsetof(raidz_map_t, rm_col[rm->rm_scols])); } static vdev_t * vdev_child(vdev_t *pvd, uint64_t devidx) { vdev_t *cvd; STAILQ_FOREACH(cvd, &pvd->v_children, v_childlink) { if (cvd->v_id == devidx) break; } return (cvd); } /* * 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(const spa_t *spa, const blkptr_t *bp, void *data, uint64_t size) { return (zio_checksum_verify(spa, bp, data)); } /* * 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(raidz_map_t *rm) { void *orig[VDEV_RAIDZ_MAXPARITY]; int c, ret = 0; raidz_col_t *rc; for (c = 0; c < rm->rm_firstdatacol; c++) { rc = &rm->rm_col[c]; if (!rc->rc_tried || rc->rc_error != 0) continue; orig[c] = zfs_alloc(rc->rc_size); bcopy(rc->rc_data, orig[c], rc->rc_size); } vdev_raidz_generate_parity(rm); for (c = rm->rm_firstdatacol - 1; c >= 0; c--) { rc = &rm->rm_col[c]; if (!rc->rc_tried || rc->rc_error != 0) continue; if (bcmp(orig[c], rc->rc_data, rc->rc_size) != 0) { rc->rc_error = ECKSUM; ret++; } zfs_free(orig[c], rc->rc_size); } return (ret); } /* * 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(const spa_t *spa, raidz_map_t *rm, const blkptr_t *bp, void *data, off_t offset, uint64_t bytes, int total_errors, int data_errors) { 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] = zfs_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]; bcopy(rc->rc_data, orig[i], rc->rc_size); } /* * Attempt a reconstruction and exit the outer loop on * success. */ code = vdev_raidz_reconstruct(rm, tgts, n); if (raidz_checksum_verify(spa, bp, data, bytes) == 0) { for (i = 0; i < n; i++) { c = tgts[i]; rc = &rm->rm_col[c]; ASSERT(rc->rc_error == 0); rc->rc_error = ECKSUM; } ret = code; goto done; } /* * Restore the original data. */ for (i = 0; i < n; i++) { c = tgts[i]; rc = &rm->rm_col[c]; bcopy(orig[i], rc->rc_data, 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 = n - 1; i >= 0; i--) { zfs_free(orig[i], rm->rm_col[0].rc_size); } return (ret); } static int vdev_raidz_read(vdev_t *vd, const blkptr_t *bp, void *data, off_t offset, size_t bytes) { vdev_t *tvd = vd->v_top; vdev_t *cvd; raidz_map_t *rm; raidz_col_t *rc; int c, error; int unexpected_errors; int parity_errors; int parity_untried; int data_errors; int total_errors; int n; int tgts[VDEV_RAIDZ_MAXPARITY]; int code; rc = NULL; /* gcc */ error = 0; rm = vdev_raidz_map_alloc(data, offset, bytes, tvd->v_ashift, vd->v_nchildren, vd->v_nparity); /* * 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 = vdev_child(vd, rc->rc_devidx); if (cvd == NULL || cvd->v_state != VDEV_STATE_HEALTHY) { if (c >= rm->rm_firstdatacol) rm->rm_missingdata++; else rm->rm_missingparity++; rc->rc_error = ENXIO; rc->rc_tried = 1; /* don't even try */ rc->rc_skipped = 1; continue; } #if 0 /* XXX: Too hard for the boot code. */ 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 = ESTALE; rc->rc_skipped = 1; continue; } #endif if (c >= rm->rm_firstdatacol || rm->rm_missingdata > 0) { rc->rc_error = cvd->v_read(cvd, NULL, rc->rc_data, rc->rc_offset, rc->rc_size); rc->rc_tried = 1; rc->rc_skipped = 0; } } reconstruct: unexpected_errors = 0; parity_errors = 0; parity_untried = 0; data_errors = 0; total_errors = 0; 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++; } } /* * 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(vd->spa, bp, data, bytes) == 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) { n = raidz_parity_verify(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(vd->spa, bp, data, bytes) == 0) { /* * 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) { n = raidz_parity_verify(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; n = 0; for (c = 0; c < rm->rm_cols; c++) { rc = &rm->rm_col[c]; if (rc->rc_tried) continue; cvd = vdev_child(vd, rc->rc_devidx); ASSERT(cvd != NULL); rc->rc_error = cvd->v_read(cvd, NULL, rc->rc_data, rc->rc_offset, rc->rc_size); if (rc->rc_error == 0) n++; rc->rc_tried = 1; rc->rc_skipped = 0; } /* * If we managed to read anything more, retry the * reconstruction. */ if (n > 0) goto reconstruct; /* * 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) { error = EIO; } else if (total_errors < rm->rm_firstdatacol && (code = vdev_raidz_combrec(vd->spa, rm, bp, data, offset, bytes, 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(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. */ error = ECKSUM; } done: vdev_raidz_map_free(rm); return (error); }