/* * 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 2008 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ #include #include #include #include /* * Checksum vectors. * * In the SPA, everything is checksummed. We support checksum vectors * for three distinct reasons: * * 1. Different kinds of data need different levels of protection. * For SPA metadata, we always want a very strong checksum. * For user data, we let users make the trade-off between speed * and checksum strength. * * 2. Cryptographic hash and MAC algorithms are an area of active research. * It is likely that in future hash functions will be at least as strong * as current best-of-breed, and may be substantially faster as well. * We want the ability to take advantage of these new hashes as soon as * they become available. * * 3. If someone develops hardware that can compute a strong hash quickly, * we want the ability to take advantage of that hardware. * * Of course, we don't want a checksum upgrade to invalidate existing * data, so we store the checksum *function* in five bits of the DVA. * This gives us room for up to 32 different checksum functions. * * When writing a block, we always checksum it with the latest-and-greatest * checksum function of the appropriate strength. When reading a block, * we compare the expected checksum against the actual checksum, which we * compute via the checksum function specified in the DVA encoding. */ /*ARGSUSED*/ static void zio_checksum_off(const void *buf, uint64_t size, zio_cksum_t *zcp) { ZIO_SET_CHECKSUM(zcp, 0, 0, 0, 0); } zio_checksum_info_t zio_checksum_table[ZIO_CHECKSUM_FUNCTIONS] = { {{NULL, NULL}, 0, 0, "inherit"}, {{NULL, NULL}, 0, 0, "on"}, {{zio_checksum_off, zio_checksum_off}, 0, 0, "off"}, {{zio_checksum_SHA256, zio_checksum_SHA256}, 1, 1, "label"}, {{zio_checksum_SHA256, zio_checksum_SHA256}, 1, 1, "gang_header"}, {{fletcher_2_native, fletcher_2_byteswap}, 0, 1, "zilog"}, {{fletcher_2_native, fletcher_2_byteswap}, 0, 0, "fletcher2"}, {{fletcher_4_native, fletcher_4_byteswap}, 1, 0, "fletcher4"}, {{zio_checksum_SHA256, zio_checksum_SHA256}, 1, 0, "SHA256"}, }; uint8_t zio_checksum_select(uint8_t child, uint8_t parent) { ASSERT(child < ZIO_CHECKSUM_FUNCTIONS); ASSERT(parent < ZIO_CHECKSUM_FUNCTIONS); ASSERT(parent != ZIO_CHECKSUM_INHERIT && parent != ZIO_CHECKSUM_ON); if (child == ZIO_CHECKSUM_INHERIT) return (parent); if (child == ZIO_CHECKSUM_ON) return (ZIO_CHECKSUM_ON_VALUE); return (child); } /* * 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, blkptr_t *bp) { dva_t *dva = BP_IDENTITY(bp); uint64_t txg = bp->blk_birth; 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); } /* * Generate the checksum. */ void zio_checksum_compute(zio_t *zio, enum zio_checksum checksum, void *data, uint64_t size) { blkptr_t *bp = zio->io_bp; uint64_t offset = zio->io_offset; zio_block_tail_t *zbt = (zio_block_tail_t *)((char *)data + size) - 1; zio_checksum_info_t *ci = &zio_checksum_table[checksum]; zio_cksum_t zbt_cksum; ASSERT((uint_t)checksum < ZIO_CHECKSUM_FUNCTIONS); ASSERT(ci->ci_func[0] != NULL); if (ci->ci_zbt) { if (checksum == ZIO_CHECKSUM_GANG_HEADER) zio_checksum_gang_verifier(&zbt->zbt_cksum, bp); else if (checksum == ZIO_CHECKSUM_LABEL) zio_checksum_label_verifier(&zbt->zbt_cksum, offset); else bp->blk_cksum = zbt->zbt_cksum; zbt->zbt_magic = ZBT_MAGIC; ci->ci_func[0](data, size, &zbt_cksum); zbt->zbt_cksum = zbt_cksum; } else { ci->ci_func[0](data, size, &bp->blk_cksum); } } int zio_checksum_error(zio_t *zio) { blkptr_t *bp = zio->io_bp; uint_t checksum = (bp == NULL ? zio->io_prop.zp_checksum : (BP_IS_GANG(bp) ? ZIO_CHECKSUM_GANG_HEADER : BP_GET_CHECKSUM(bp))); int byteswap; void *data = zio->io_data; uint64_t size = (bp == NULL ? zio->io_size : (BP_IS_GANG(bp) ? SPA_GANGBLOCKSIZE : BP_GET_PSIZE(bp))); uint64_t offset = zio->io_offset; zio_block_tail_t *zbt = (zio_block_tail_t *)((char *)data + size) - 1; zio_checksum_info_t *ci = &zio_checksum_table[checksum]; zio_cksum_t actual_cksum, expected_cksum, verifier; if (checksum >= ZIO_CHECKSUM_FUNCTIONS || ci->ci_func[0] == NULL) return (EINVAL); if (ci->ci_zbt) { if (checksum == ZIO_CHECKSUM_GANG_HEADER) zio_checksum_gang_verifier(&verifier, bp); else if (checksum == ZIO_CHECKSUM_LABEL) zio_checksum_label_verifier(&verifier, offset); else verifier = bp->blk_cksum; byteswap = (zbt->zbt_magic == BSWAP_64(ZBT_MAGIC)); if (byteswap) byteswap_uint64_array(&verifier, sizeof (zio_cksum_t)); expected_cksum = zbt->zbt_cksum; zbt->zbt_cksum = verifier; ci->ci_func[byteswap](data, size, &actual_cksum); zbt->zbt_cksum = expected_cksum; if (byteswap) byteswap_uint64_array(&expected_cksum, sizeof (zio_cksum_t)); } else { ASSERT(!BP_IS_GANG(bp)); byteswap = BP_SHOULD_BYTESWAP(bp); expected_cksum = bp->blk_cksum; ci->ci_func[byteswap](data, size, &actual_cksum); } if (!ZIO_CHECKSUM_EQUAL(actual_cksum, expected_cksum)) return (ECKSUM); if (zio_injection_enabled && !zio->io_error) return (zio_handle_fault_injection(zio, ECKSUM)); return (0); }