1fa9e4066Sahrens /* 2fa9e4066Sahrens * CDDL HEADER START 3fa9e4066Sahrens * 4fa9e4066Sahrens * The contents of this file are subject to the terms of the 5ea8dc4b6Seschrock * Common Development and Distribution License (the "License"). 6ea8dc4b6Seschrock * You may not use this file except in compliance with the License. 7fa9e4066Sahrens * 8fa9e4066Sahrens * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9fa9e4066Sahrens * or http://www.opensolaris.org/os/licensing. 10fa9e4066Sahrens * See the License for the specific language governing permissions 11fa9e4066Sahrens * and limitations under the License. 12fa9e4066Sahrens * 13fa9e4066Sahrens * When distributing Covered Code, include this CDDL HEADER in each 14fa9e4066Sahrens * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15fa9e4066Sahrens * If applicable, add the following below this CDDL HEADER, with the 16fa9e4066Sahrens * fields enclosed by brackets "[]" replaced with your own identifying 17fa9e4066Sahrens * information: Portions Copyright [yyyy] [name of copyright owner] 18fa9e4066Sahrens * 19fa9e4066Sahrens * CDDL HEADER END 20fa9e4066Sahrens */ 21fa9e4066Sahrens /* 22*cde58dbcSMatthew Ahrens * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23fa9e4066Sahrens */ 24fa9e4066Sahrens 25fa9e4066Sahrens #include <sys/zfs_context.h> 26fa9e4066Sahrens #include <sys/spa.h> 27fa9e4066Sahrens #include <sys/zio.h> 28fa9e4066Sahrens #include <sys/zio_checksum.h> 296e1f5caaSNeil Perrin #include <sys/zil.h> 30*cde58dbcSMatthew Ahrens #include <zfs_fletcher.h> 31fa9e4066Sahrens 32fa9e4066Sahrens /* 33fa9e4066Sahrens * Checksum vectors. 34fa9e4066Sahrens * 35fa9e4066Sahrens * In the SPA, everything is checksummed. We support checksum vectors 36fa9e4066Sahrens * for three distinct reasons: 37fa9e4066Sahrens * 38fa9e4066Sahrens * 1. Different kinds of data need different levels of protection. 39fa9e4066Sahrens * For SPA metadata, we always want a very strong checksum. 40fa9e4066Sahrens * For user data, we let users make the trade-off between speed 41fa9e4066Sahrens * and checksum strength. 42fa9e4066Sahrens * 43fa9e4066Sahrens * 2. Cryptographic hash and MAC algorithms are an area of active research. 44fa9e4066Sahrens * It is likely that in future hash functions will be at least as strong 45fa9e4066Sahrens * as current best-of-breed, and may be substantially faster as well. 46fa9e4066Sahrens * We want the ability to take advantage of these new hashes as soon as 47fa9e4066Sahrens * they become available. 48fa9e4066Sahrens * 49fa9e4066Sahrens * 3. If someone develops hardware that can compute a strong hash quickly, 50fa9e4066Sahrens * we want the ability to take advantage of that hardware. 51fa9e4066Sahrens * 52fa9e4066Sahrens * Of course, we don't want a checksum upgrade to invalidate existing 53b24ab676SJeff Bonwick * data, so we store the checksum *function* in eight bits of the bp. 54b24ab676SJeff Bonwick * This gives us room for up to 256 different checksum functions. 55fa9e4066Sahrens * 56fa9e4066Sahrens * When writing a block, we always checksum it with the latest-and-greatest 57fa9e4066Sahrens * checksum function of the appropriate strength. When reading a block, 58fa9e4066Sahrens * we compare the expected checksum against the actual checksum, which we 59b24ab676SJeff Bonwick * compute via the checksum function specified by BP_GET_CHECKSUM(bp). 60fa9e4066Sahrens */ 61fa9e4066Sahrens 62fa9e4066Sahrens /*ARGSUSED*/ 63fa9e4066Sahrens static void 64fa9e4066Sahrens zio_checksum_off(const void *buf, uint64_t size, zio_cksum_t *zcp) 65fa9e4066Sahrens { 66fa9e4066Sahrens ZIO_SET_CHECKSUM(zcp, 0, 0, 0, 0); 67fa9e4066Sahrens } 68fa9e4066Sahrens 69fa9e4066Sahrens zio_checksum_info_t zio_checksum_table[ZIO_CHECKSUM_FUNCTIONS] = { 70b24ab676SJeff Bonwick {{NULL, NULL}, 0, 0, 0, "inherit"}, 71b24ab676SJeff Bonwick {{NULL, NULL}, 0, 0, 0, "on"}, 72b24ab676SJeff Bonwick {{zio_checksum_off, zio_checksum_off}, 0, 0, 0, "off"}, 73b24ab676SJeff Bonwick {{zio_checksum_SHA256, zio_checksum_SHA256}, 1, 1, 0, "label"}, 74b24ab676SJeff Bonwick {{zio_checksum_SHA256, zio_checksum_SHA256}, 1, 1, 0, "gang_header"}, 75b24ab676SJeff Bonwick {{fletcher_2_native, fletcher_2_byteswap}, 0, 1, 0, "zilog"}, 76b24ab676SJeff Bonwick {{fletcher_2_native, fletcher_2_byteswap}, 0, 0, 0, "fletcher2"}, 77b24ab676SJeff Bonwick {{fletcher_4_native, fletcher_4_byteswap}, 1, 0, 0, "fletcher4"}, 78b24ab676SJeff Bonwick {{zio_checksum_SHA256, zio_checksum_SHA256}, 1, 0, 1, "sha256"}, 796e1f5caaSNeil Perrin {{fletcher_4_native, fletcher_4_byteswap}, 0, 1, 0, "zilog2"}, 80fa9e4066Sahrens }; 81fa9e4066Sahrens 82b24ab676SJeff Bonwick enum zio_checksum 83b24ab676SJeff Bonwick zio_checksum_select(enum zio_checksum child, enum zio_checksum parent) 84fa9e4066Sahrens { 85fa9e4066Sahrens ASSERT(child < ZIO_CHECKSUM_FUNCTIONS); 86fa9e4066Sahrens ASSERT(parent < ZIO_CHECKSUM_FUNCTIONS); 87fa9e4066Sahrens ASSERT(parent != ZIO_CHECKSUM_INHERIT && parent != ZIO_CHECKSUM_ON); 88fa9e4066Sahrens 89fa9e4066Sahrens if (child == ZIO_CHECKSUM_INHERIT) 90fa9e4066Sahrens return (parent); 91fa9e4066Sahrens 92fa9e4066Sahrens if (child == ZIO_CHECKSUM_ON) 93fa9e4066Sahrens return (ZIO_CHECKSUM_ON_VALUE); 94fa9e4066Sahrens 95fa9e4066Sahrens return (child); 96fa9e4066Sahrens } 97fa9e4066Sahrens 98b24ab676SJeff Bonwick enum zio_checksum 99b24ab676SJeff Bonwick zio_checksum_dedup_select(spa_t *spa, enum zio_checksum child, 100b24ab676SJeff Bonwick enum zio_checksum parent) 101b24ab676SJeff Bonwick { 102b24ab676SJeff Bonwick ASSERT((child & ZIO_CHECKSUM_MASK) < ZIO_CHECKSUM_FUNCTIONS); 103b24ab676SJeff Bonwick ASSERT((parent & ZIO_CHECKSUM_MASK) < ZIO_CHECKSUM_FUNCTIONS); 104b24ab676SJeff Bonwick ASSERT(parent != ZIO_CHECKSUM_INHERIT && parent != ZIO_CHECKSUM_ON); 105b24ab676SJeff Bonwick 106b24ab676SJeff Bonwick if (child == ZIO_CHECKSUM_INHERIT) 107b24ab676SJeff Bonwick return (parent); 108b24ab676SJeff Bonwick 109b24ab676SJeff Bonwick if (child == ZIO_CHECKSUM_ON) 110b24ab676SJeff Bonwick return (spa_dedup_checksum(spa)); 111b24ab676SJeff Bonwick 112b24ab676SJeff Bonwick if (child == (ZIO_CHECKSUM_ON | ZIO_CHECKSUM_VERIFY)) 113b24ab676SJeff Bonwick return (spa_dedup_checksum(spa) | ZIO_CHECKSUM_VERIFY); 114b24ab676SJeff Bonwick 115b24ab676SJeff Bonwick ASSERT(zio_checksum_table[child & ZIO_CHECKSUM_MASK].ci_dedup || 116b24ab676SJeff Bonwick (child & ZIO_CHECKSUM_VERIFY) || child == ZIO_CHECKSUM_OFF); 117b24ab676SJeff Bonwick 118b24ab676SJeff Bonwick return (child); 119b24ab676SJeff Bonwick } 120b24ab676SJeff Bonwick 121e14bb325SJeff Bonwick /* 122e14bb325SJeff Bonwick * Set the external verifier for a gang block based on <vdev, offset, txg>, 123e14bb325SJeff Bonwick * a tuple which is guaranteed to be unique for the life of the pool. 124e14bb325SJeff Bonwick */ 125e14bb325SJeff Bonwick static void 126e14bb325SJeff Bonwick zio_checksum_gang_verifier(zio_cksum_t *zcp, blkptr_t *bp) 127e14bb325SJeff Bonwick { 128e14bb325SJeff Bonwick dva_t *dva = BP_IDENTITY(bp); 129b24ab676SJeff Bonwick uint64_t txg = BP_PHYSICAL_BIRTH(bp); 130e14bb325SJeff Bonwick 131e14bb325SJeff Bonwick ASSERT(BP_IS_GANG(bp)); 132e14bb325SJeff Bonwick 133e14bb325SJeff Bonwick ZIO_SET_CHECKSUM(zcp, DVA_GET_VDEV(dva), DVA_GET_OFFSET(dva), txg, 0); 134e14bb325SJeff Bonwick } 135e14bb325SJeff Bonwick 136e14bb325SJeff Bonwick /* 137e14bb325SJeff Bonwick * Set the external verifier for a label block based on its offset. 138e14bb325SJeff Bonwick * The vdev is implicit, and the txg is unknowable at pool open time -- 139e14bb325SJeff Bonwick * hence the logic in vdev_uberblock_load() to find the most recent copy. 140e14bb325SJeff Bonwick */ 141e14bb325SJeff Bonwick static void 142e14bb325SJeff Bonwick zio_checksum_label_verifier(zio_cksum_t *zcp, uint64_t offset) 143e14bb325SJeff Bonwick { 144e14bb325SJeff Bonwick ZIO_SET_CHECKSUM(zcp, offset, 0, 0, 0); 145e14bb325SJeff Bonwick } 146e14bb325SJeff Bonwick 147fa9e4066Sahrens /* 148fa9e4066Sahrens * Generate the checksum. 149fa9e4066Sahrens */ 150fa9e4066Sahrens void 151e14bb325SJeff Bonwick zio_checksum_compute(zio_t *zio, enum zio_checksum checksum, 152e14bb325SJeff Bonwick void *data, uint64_t size) 153fa9e4066Sahrens { 154e14bb325SJeff Bonwick blkptr_t *bp = zio->io_bp; 155e14bb325SJeff Bonwick uint64_t offset = zio->io_offset; 156fa9e4066Sahrens zio_checksum_info_t *ci = &zio_checksum_table[checksum]; 1576e1f5caaSNeil Perrin zio_cksum_t cksum; 158fa9e4066Sahrens 159e14bb325SJeff Bonwick ASSERT((uint_t)checksum < ZIO_CHECKSUM_FUNCTIONS); 160fa9e4066Sahrens ASSERT(ci->ci_func[0] != NULL); 161fa9e4066Sahrens 1626e1f5caaSNeil Perrin if (ci->ci_eck) { 1636e1f5caaSNeil Perrin zio_eck_t *eck; 1646e1f5caaSNeil Perrin 1656e1f5caaSNeil Perrin if (checksum == ZIO_CHECKSUM_ZILOG2) { 1666e1f5caaSNeil Perrin zil_chain_t *zilc = data; 1676e1f5caaSNeil Perrin 1686e1f5caaSNeil Perrin size = P2ROUNDUP_TYPED(zilc->zc_nused, ZIL_MIN_BLKSZ, 1696e1f5caaSNeil Perrin uint64_t); 1706e1f5caaSNeil Perrin eck = &zilc->zc_eck; 1716e1f5caaSNeil Perrin } else { 1726e1f5caaSNeil Perrin eck = (zio_eck_t *)((char *)data + size) - 1; 1736e1f5caaSNeil Perrin } 174e14bb325SJeff Bonwick if (checksum == ZIO_CHECKSUM_GANG_HEADER) 1756e1f5caaSNeil Perrin zio_checksum_gang_verifier(&eck->zec_cksum, bp); 176e14bb325SJeff Bonwick else if (checksum == ZIO_CHECKSUM_LABEL) 1776e1f5caaSNeil Perrin zio_checksum_label_verifier(&eck->zec_cksum, offset); 178e14bb325SJeff Bonwick else 1796e1f5caaSNeil Perrin bp->blk_cksum = eck->zec_cksum; 1806e1f5caaSNeil Perrin eck->zec_magic = ZEC_MAGIC; 1816e1f5caaSNeil Perrin ci->ci_func[0](data, size, &cksum); 1826e1f5caaSNeil Perrin eck->zec_cksum = cksum; 183fa9e4066Sahrens } else { 184e14bb325SJeff Bonwick ci->ci_func[0](data, size, &bp->blk_cksum); 185fa9e4066Sahrens } 186fa9e4066Sahrens } 187fa9e4066Sahrens 188fa9e4066Sahrens int 18922fe2c88SJonathan Adams zio_checksum_error(zio_t *zio, zio_bad_cksum_t *info) 190fa9e4066Sahrens { 191fa9e4066Sahrens blkptr_t *bp = zio->io_bp; 192e14bb325SJeff Bonwick uint_t checksum = (bp == NULL ? zio->io_prop.zp_checksum : 193e14bb325SJeff Bonwick (BP_IS_GANG(bp) ? ZIO_CHECKSUM_GANG_HEADER : BP_GET_CHECKSUM(bp))); 194e14bb325SJeff Bonwick int byteswap; 19522fe2c88SJonathan Adams int error; 196e14bb325SJeff Bonwick uint64_t size = (bp == NULL ? zio->io_size : 197e14bb325SJeff Bonwick (BP_IS_GANG(bp) ? SPA_GANGBLOCKSIZE : BP_GET_PSIZE(bp))); 198e14bb325SJeff Bonwick uint64_t offset = zio->io_offset; 19922fe2c88SJonathan Adams void *data = zio->io_data; 200fa9e4066Sahrens zio_checksum_info_t *ci = &zio_checksum_table[checksum]; 201e14bb325SJeff Bonwick zio_cksum_t actual_cksum, expected_cksum, verifier; 202fa9e4066Sahrens 203fa9e4066Sahrens if (checksum >= ZIO_CHECKSUM_FUNCTIONS || ci->ci_func[0] == NULL) 204fa9e4066Sahrens return (EINVAL); 205fa9e4066Sahrens 2066e1f5caaSNeil Perrin if (ci->ci_eck) { 2076e1f5caaSNeil Perrin zio_eck_t *eck; 2086e1f5caaSNeil Perrin 2096e1f5caaSNeil Perrin if (checksum == ZIO_CHECKSUM_ZILOG2) { 2106e1f5caaSNeil Perrin zil_chain_t *zilc = data; 2116e1f5caaSNeil Perrin uint64_t nused; 2126e1f5caaSNeil Perrin 2136e1f5caaSNeil Perrin eck = &zilc->zc_eck; 2146e1f5caaSNeil Perrin if (eck->zec_magic == ZEC_MAGIC) 2156e1f5caaSNeil Perrin nused = zilc->zc_nused; 2166e1f5caaSNeil Perrin else if (eck->zec_magic == BSWAP_64(ZEC_MAGIC)) 2176e1f5caaSNeil Perrin nused = BSWAP_64(zilc->zc_nused); 2186e1f5caaSNeil Perrin else 2196e1f5caaSNeil Perrin return (ECKSUM); 2206e1f5caaSNeil Perrin 2216e1f5caaSNeil Perrin if (nused > size) 2226e1f5caaSNeil Perrin return (ECKSUM); 2236e1f5caaSNeil Perrin 2246e1f5caaSNeil Perrin size = P2ROUNDUP_TYPED(nused, ZIL_MIN_BLKSZ, uint64_t); 2256e1f5caaSNeil Perrin } else { 2266e1f5caaSNeil Perrin eck = (zio_eck_t *)((char *)data + size) - 1; 2276e1f5caaSNeil Perrin } 2286e1f5caaSNeil Perrin 229fa9e4066Sahrens if (checksum == ZIO_CHECKSUM_GANG_HEADER) 230e14bb325SJeff Bonwick zio_checksum_gang_verifier(&verifier, bp); 231e14bb325SJeff Bonwick else if (checksum == ZIO_CHECKSUM_LABEL) 232e14bb325SJeff Bonwick zio_checksum_label_verifier(&verifier, offset); 233e14bb325SJeff Bonwick else 234e14bb325SJeff Bonwick verifier = bp->blk_cksum; 235e14bb325SJeff Bonwick 2366e1f5caaSNeil Perrin byteswap = (eck->zec_magic == BSWAP_64(ZEC_MAGIC)); 237fa9e4066Sahrens 238e14bb325SJeff Bonwick if (byteswap) 239e14bb325SJeff Bonwick byteswap_uint64_array(&verifier, sizeof (zio_cksum_t)); 240e14bb325SJeff Bonwick 2416e1f5caaSNeil Perrin expected_cksum = eck->zec_cksum; 2426e1f5caaSNeil Perrin eck->zec_cksum = verifier; 243e14bb325SJeff Bonwick ci->ci_func[byteswap](data, size, &actual_cksum); 2446e1f5caaSNeil Perrin eck->zec_cksum = expected_cksum; 245e14bb325SJeff Bonwick 246e14bb325SJeff Bonwick if (byteswap) 247fa9e4066Sahrens byteswap_uint64_array(&expected_cksum, 248fa9e4066Sahrens sizeof (zio_cksum_t)); 249fa9e4066Sahrens } else { 25044cd46caSbillm ASSERT(!BP_IS_GANG(bp)); 251e14bb325SJeff Bonwick byteswap = BP_SHOULD_BYTESWAP(bp); 252e14bb325SJeff Bonwick expected_cksum = bp->blk_cksum; 253fa9e4066Sahrens ci->ci_func[byteswap](data, size, &actual_cksum); 254fa9e4066Sahrens } 255fa9e4066Sahrens 25622fe2c88SJonathan Adams info->zbc_expected = expected_cksum; 25722fe2c88SJonathan Adams info->zbc_actual = actual_cksum; 25822fe2c88SJonathan Adams info->zbc_checksum_name = ci->ci_name; 25922fe2c88SJonathan Adams info->zbc_byteswapped = byteswap; 26022fe2c88SJonathan Adams info->zbc_injected = 0; 26122fe2c88SJonathan Adams info->zbc_has_cksum = 1; 26222fe2c88SJonathan Adams 263e14bb325SJeff Bonwick if (!ZIO_CHECKSUM_EQUAL(actual_cksum, expected_cksum)) 264fa9e4066Sahrens return (ECKSUM); 265fa9e4066Sahrens 26622fe2c88SJonathan Adams if (zio_injection_enabled && !zio->io_error && 26722fe2c88SJonathan Adams (error = zio_handle_fault_injection(zio, ECKSUM)) != 0) { 26822fe2c88SJonathan Adams 26922fe2c88SJonathan Adams info->zbc_injected = 1; 27022fe2c88SJonathan Adams return (error); 27122fe2c88SJonathan Adams } 272ea8dc4b6Seschrock 273fa9e4066Sahrens return (0); 274fa9e4066Sahrens } 275