module/zfs/zio_checksum.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  23  * Copyright (c) 2013, 2016 by Delphix. All rights reserved.
  24  * Copyright 2013 Saso Kiselkov. All rights reserved.
  25  */
  26
  27 #include <sys/zfs_context.h>
  28 #include <sys/spa.h>
  29 #include <sys/spa_impl.h>
  30 #include <sys/zio.h>
  31 #include <sys/zio_checksum.h>
  32 #include <sys/zil.h>
  33 #include <sys/abd.h>
  34 #include <zfs_fletcher.h>
  35
  36 /*
  37  * Checksum vectors.
  38  *
  39  * In the SPA, everything is checksummed.  We support checksum vectors
  40  * for three distinct reasons:
  41  *
  42  *   1. Different kinds of data need different levels of protection.
  43  *      For SPA metadata, we always want a very strong checksum.
  44  *      For user data, we let users make the trade-off between speed
  45  *      and checksum strength.
  46  *
  47  *   2. Cryptographic hash and MAC algorithms are an area of active research.
  48  *      It is likely that in future hash functions will be at least as strong
  49  *      as current best-of-breed, and may be substantially faster as well.
  50  *      We want the ability to take advantage of these new hashes as soon as
  51  *      they become available.
  52  *
  53  *   3. If someone develops hardware that can compute a strong hash quickly,
  54  *      we want the ability to take advantage of that hardware.
  55  *
  56  * Of course, we don't want a checksum upgrade to invalidate existing
  57  * data, so we store the checksum *function* in eight bits of the bp.
  58  * This gives us room for up to 256 different checksum functions.
  59  *
  60  * When writing a block, we always checksum it with the latest-and-greatest
  61  * checksum function of the appropriate strength.  When reading a block,
  62  * we compare the expected checksum against the actual checksum, which we
  63  * compute via the checksum function specified by BP_GET_CHECKSUM(bp).
  64  *
  65  * SALTED CHECKSUMS
  66  *
  67  * To enable the use of less secure hash algorithms with dedup, we
  68  * introduce the notion of salted checksums (MACs, really).  A salted
  69  * checksum is fed both a random 256-bit value (the salt) and the data
  70  * to be checksummed.  This salt is kept secret (stored on the pool, but
  71  * never shown to the user).  Thus even if an attacker knew of collision
  72  * weaknesses in the hash algorithm, they won't be able to mount a known
  73  * plaintext attack on the DDT, since the actual hash value cannot be
  74  * known ahead of time.  How the salt is used is algorithm-specific
  75  * (some might simply prefix it to the data block, others might need to
  76  * utilize a full-blown HMAC).  On disk the salt is stored in a ZAP
  77  * object in the MOS (DMU_POOL_CHECKSUM_SALT).
  78  *
  79  * CONTEXT TEMPLATES
  80  *
  81  * Some hashing algorithms need to perform a substantial amount of
  82  * initialization work (e.g. salted checksums above may need to pre-hash
  83  * the salt) before being able to process data.  Performing this
  84  * redundant work for each block would be wasteful, so we instead allow
  85  * a checksum algorithm to do the work once (the first time it's used)
  86  * and then keep this pre-initialized context as a template inside the
  87  * spa_t (spa_cksum_tmpls).  If the zio_checksum_info_t contains
  88  * non-NULL ci_tmpl_init and ci_tmpl_free callbacks, they are used to
  89  * construct and destruct the pre-initialized checksum context.  The
  90  * pre-initialized context is then reused during each checksum
  91  * invocation and passed to the checksum function.
  92  */
  93
  94 /*ARGSUSED*/
  95 static void
  96 abd_checksum_off(abd_t *abd, uint64_t size,
  97     const void *ctx_template, zio_cksum_t *zcp)
  98 {
  99         ZIO_SET_CHECKSUM(zcp, 0, 0, 0, 0);
 100 }
 101
 102 /*ARGSUSED*/
 103 void
 104 abd_fletcher_2_native(abd_t *abd, uint64_t size,
 105     const void *ctx_template, zio_cksum_t *zcp)
 106 {
 107         fletcher_init(zcp);
 108         (void) abd_iterate_func(abd, 0, size,
 109             fletcher_2_incremental_native, zcp);
 110 }
 111
 112 /*ARGSUSED*/
 113 void
 114 abd_fletcher_2_byteswap(abd_t *abd, uint64_t size,
 115     const void *ctx_template, zio_cksum_t *zcp)
 116 {
 117         fletcher_init(zcp);
 118         (void) abd_iterate_func(abd, 0, size,
 119             fletcher_2_incremental_byteswap, zcp);
 120 }
 121
 122 static inline void
 123 abd_fletcher_4_impl(abd_t *abd, uint64_t size, zio_abd_checksum_data_t *acdp)
 124 {
 125         fletcher_4_abd_ops.acf_init(acdp);
 126         abd_iterate_func(abd, 0, size, fletcher_4_abd_ops.acf_iter, acdp);
 127         fletcher_4_abd_ops.acf_fini(acdp);
 128 }
 129
 130 /*ARGSUSED*/
 131 void
 132 abd_fletcher_4_native(abd_t *abd, uint64_t size,
 133     const void *ctx_template, zio_cksum_t *zcp)
 134 {
 135         fletcher_4_ctx_t ctx;
 136
 137         zio_abd_checksum_data_t acd = {
 138                 .acd_byteorder  = ZIO_CHECKSUM_NATIVE,
 139                 .acd_zcp        = zcp,
 140                 .acd_ctx        = &ctx
 141         };
 142
 143         abd_fletcher_4_impl(abd, size, &acd);
 144
 145 }
 146
 147 /*ARGSUSED*/
 148 void
 149 abd_fletcher_4_byteswap(abd_t *abd, uint64_t size,
 150     const void *ctx_template, zio_cksum_t *zcp)
 151 {
 152         fletcher_4_ctx_t ctx;
 153
 154         zio_abd_checksum_data_t acd = {
 155                 .acd_byteorder  = ZIO_CHECKSUM_BYTESWAP,
 156                 .acd_zcp        = zcp,
 157                 .acd_ctx        = &ctx
 158         };
 159
 160         abd_fletcher_4_impl(abd, size, &acd);
 161 }
 162
 163 zio_checksum_info_t zio_checksum_table[ZIO_CHECKSUM_FUNCTIONS] = {
 164         {{NULL, NULL}, NULL, NULL, 0, "inherit"},
 165         {{NULL, NULL}, NULL, NULL, 0, "on"},
 166         {{abd_checksum_off,             abd_checksum_off},
 167             NULL, NULL, 0, "off"},
 168         {{abd_checksum_SHA256,          abd_checksum_SHA256},
 169             NULL, NULL, ZCHECKSUM_FLAG_METADATA | ZCHECKSUM_FLAG_EMBEDDED,
 170             "label"},
 171         {{abd_checksum_SHA256,          abd_checksum_SHA256},
 172             NULL, NULL, ZCHECKSUM_FLAG_METADATA | ZCHECKSUM_FLAG_EMBEDDED,
 173             "gang_header"},
 174         {{abd_fletcher_2_native,        abd_fletcher_2_byteswap},
 175             NULL, NULL, ZCHECKSUM_FLAG_EMBEDDED, "zilog"},
 176         {{abd_fletcher_2_native,        abd_fletcher_2_byteswap},
 177             NULL, NULL, 0, "fletcher2"},
 178         {{abd_fletcher_4_native,        abd_fletcher_4_byteswap},
 179             NULL, NULL, ZCHECKSUM_FLAG_METADATA, "fletcher4"},
 180         {{abd_checksum_SHA256,          abd_checksum_SHA256},
 181             NULL, NULL, ZCHECKSUM_FLAG_METADATA | ZCHECKSUM_FLAG_DEDUP |
 182             ZCHECKSUM_FLAG_NOPWRITE, "sha256"},
 183         {{abd_fletcher_4_native,        abd_fletcher_4_byteswap},
 184             NULL, NULL, ZCHECKSUM_FLAG_EMBEDDED, "zilog2"},
 185         {{abd_checksum_off,             abd_checksum_off},
 186             NULL, NULL, 0, "noparity"},
 187         {{abd_checksum_SHA512_native,   abd_checksum_SHA512_byteswap},
 188             NULL, NULL, ZCHECKSUM_FLAG_METADATA | ZCHECKSUM_FLAG_DEDUP |
 189             ZCHECKSUM_FLAG_NOPWRITE, "sha512"},
 190         {{abd_checksum_skein_native,    abd_checksum_skein_byteswap},
 191             abd_checksum_skein_tmpl_init, abd_checksum_skein_tmpl_free,
 192             ZCHECKSUM_FLAG_METADATA | ZCHECKSUM_FLAG_DEDUP |
 193             ZCHECKSUM_FLAG_SALTED | ZCHECKSUM_FLAG_NOPWRITE, "skein"},
 194         {{abd_checksum_edonr_native,    abd_checksum_edonr_byteswap},
 195             abd_checksum_edonr_tmpl_init, abd_checksum_edonr_tmpl_free,
 196             ZCHECKSUM_FLAG_METADATA | ZCHECKSUM_FLAG_SALTED |
 197             ZCHECKSUM_FLAG_NOPWRITE, "edonr"},
 198 };
 199
 200 /*
 201  * The flag corresponding to the "verify" in dedup=[checksum,]verify
 202  * must be cleared first, so callers should use ZIO_CHECKSUM_MASK.
 203  */
 204 spa_feature_t
 205 zio_checksum_to_feature(enum zio_checksum cksum)
 206 {
 207         VERIFY((cksum & ~ZIO_CHECKSUM_MASK) == 0);
 208
 209         switch (cksum) {
 210         case ZIO_CHECKSUM_SHA512:
 211                 return (SPA_FEATURE_SHA512);
 212         case ZIO_CHECKSUM_SKEIN:
 213                 return (SPA_FEATURE_SKEIN);
 214         case ZIO_CHECKSUM_EDONR:
 215                 return (SPA_FEATURE_EDONR);
 216         default:
 217                 return (SPA_FEATURE_NONE);
 218         }
 219 }
 220
 221 enum zio_checksum
 222 zio_checksum_select(enum zio_checksum child, enum zio_checksum parent)
 223 {
 224         ASSERT(child < ZIO_CHECKSUM_FUNCTIONS);
 225         ASSERT(parent < ZIO_CHECKSUM_FUNCTIONS);
 226         ASSERT(parent != ZIO_CHECKSUM_INHERIT && parent != ZIO_CHECKSUM_ON);
 227
 228         if (child == ZIO_CHECKSUM_INHERIT)
 229                 return (parent);
 230
 231         if (child == ZIO_CHECKSUM_ON)
 232                 return (ZIO_CHECKSUM_ON_VALUE);
 233
 234         return (child);
 235 }
 236
 237 enum zio_checksum
 238 zio_checksum_dedup_select(spa_t *spa, enum zio_checksum child,
 239     enum zio_checksum parent)
 240 {
 241         ASSERT((child & ZIO_CHECKSUM_MASK) < ZIO_CHECKSUM_FUNCTIONS);
 242         ASSERT((parent & ZIO_CHECKSUM_MASK) < ZIO_CHECKSUM_FUNCTIONS);
 243         ASSERT(parent != ZIO_CHECKSUM_INHERIT && parent != ZIO_CHECKSUM_ON);
 244
 245         if (child == ZIO_CHECKSUM_INHERIT)
 246                 return (parent);
 247
 248         if (child == ZIO_CHECKSUM_ON)
 249                 return (spa_dedup_checksum(spa));
 250
 251         if (child == (ZIO_CHECKSUM_ON | ZIO_CHECKSUM_VERIFY))
 252                 return (spa_dedup_checksum(spa) | ZIO_CHECKSUM_VERIFY);
 253
 254         ASSERT((zio_checksum_table[child & ZIO_CHECKSUM_MASK].ci_flags &
 255             ZCHECKSUM_FLAG_DEDUP) ||
 256             (child & ZIO_CHECKSUM_VERIFY) || child == ZIO_CHECKSUM_OFF);
 257
 258         return (child);
 259 }
 260
 261 /*
 262  * Set the external verifier for a gang block based on <vdev, offset, txg>,
 263  * a tuple which is guaranteed to be unique for the life of the pool.
 264  */
 265 static void
 266 zio_checksum_gang_verifier(zio_cksum_t *zcp, const blkptr_t *bp)
 267 {
 268         const dva_t *dva = BP_IDENTITY(bp);
 269         uint64_t txg = BP_PHYSICAL_BIRTH(bp);
 270
 271         ASSERT(BP_IS_GANG(bp));
 272
 273         ZIO_SET_CHECKSUM(zcp, DVA_GET_VDEV(dva), DVA_GET_OFFSET(dva), txg, 0);
 274 }
 275
 276 /*
 277  * Set the external verifier for a label block based on its offset.
 278  * The vdev is implicit, and the txg is unknowable at pool open time --
 279  * hence the logic in vdev_uberblock_load() to find the most recent copy.
 280  */
 281 static void
 282 zio_checksum_label_verifier(zio_cksum_t *zcp, uint64_t offset)
 283 {
 284         ZIO_SET_CHECKSUM(zcp, offset, 0, 0, 0);
 285 }
 286
 287 /*
 288  * Calls the template init function of a checksum which supports context
 289  * templates and installs the template into the spa_t.
 290  */
 291 static void
 292 zio_checksum_template_init(enum zio_checksum checksum, spa_t *spa)
 293 {
 294         zio_checksum_info_t *ci = &zio_checksum_table[checksum];
 295
 296         if (ci->ci_tmpl_init == NULL)
 297                 return;
 298         if (spa->spa_cksum_tmpls[checksum] != NULL)
 299                 return;
 300
 301         VERIFY(ci->ci_tmpl_free != NULL);
 302         mutex_enter(&spa->spa_cksum_tmpls_lock);
 303         if (spa->spa_cksum_tmpls[checksum] == NULL) {
 304                 spa->spa_cksum_tmpls[checksum] =
 305                     ci->ci_tmpl_init(&spa->spa_cksum_salt);
 306                 VERIFY(spa->spa_cksum_tmpls[checksum] != NULL);
 307         }
 308         mutex_exit(&spa->spa_cksum_tmpls_lock);
 309 }
 310
 311 /* convenience function to update a checksum to accomodate an encryption MAC */
 312 static void
 313 zio_checksum_handle_crypt(zio_cksum_t *cksum, zio_cksum_t *saved, boolean_t xor)
 314 {
 315         /*
 316          * Weak checksums do not have their entropy spread evenly
 317          * across the bits of the checksum. Therefore, when truncating
 318          * a weak checksum we XOR the first 2 words with the last 2 so
 319          * that we don't "lose" any entropy unnecessarily.
 320          */
 321         if (xor) {
 322                 cksum->zc_word[0] ^= cksum->zc_word[2];
 323                 cksum->zc_word[1] ^= cksum->zc_word[3];
 324         }
 325
 326         cksum->zc_word[2] = saved->zc_word[2];
 327         cksum->zc_word[3] = saved->zc_word[3];
 328 }
 329
 330 /*
 331  * Generate the checksum.
 332  */
 333 void
 334 zio_checksum_compute(zio_t *zio, enum zio_checksum checksum,
 335     abd_t *abd, uint64_t size)
 336 {
 337         static const uint64_t zec_magic = ZEC_MAGIC;
 338         blkptr_t *bp = zio->io_bp;
 339         uint64_t offset = zio->io_offset;
 340         zio_checksum_info_t *ci = &zio_checksum_table[checksum];
 341         zio_cksum_t cksum, saved;
 342         spa_t *spa = zio->io_spa;
 343         boolean_t insecure = (ci->ci_flags & ZCHECKSUM_FLAG_DEDUP) == 0;
 344
 345         ASSERT((uint_t)checksum < ZIO_CHECKSUM_FUNCTIONS);
 346         ASSERT(ci->ci_func[0] != NULL);
 347
 348         zio_checksum_template_init(checksum, spa);
 349
 350         if (ci->ci_flags & ZCHECKSUM_FLAG_EMBEDDED) {
 351                 zio_eck_t eck;
 352                 size_t eck_offset;
 353
 354                 bzero(&saved, sizeof (zio_cksum_t));
 355
 356                 if (checksum == ZIO_CHECKSUM_ZILOG2) {
 357                         zil_chain_t zilc;
 358                         abd_copy_to_buf(&zilc, abd, sizeof (zil_chain_t));
 359
 360                         size = P2ROUNDUP_TYPED(zilc.zc_nused, ZIL_MIN_BLKSZ,
 361                             uint64_t);
 362                         eck = zilc.zc_eck;
 363                         eck_offset = offsetof(zil_chain_t, zc_eck);
 364                 } else {
 365                         eck_offset = size - sizeof (zio_eck_t);
 366                         abd_copy_to_buf_off(&eck, abd, eck_offset,
 367                             sizeof (zio_eck_t));
 368                 }
 369
 370                 if (checksum == ZIO_CHECKSUM_GANG_HEADER) {
 371                         zio_checksum_gang_verifier(&eck.zec_cksum, bp);
 372                 } else if (checksum == ZIO_CHECKSUM_LABEL) {
 373                         zio_checksum_label_verifier(&eck.zec_cksum, offset);
 374                 } else {
 375                         saved = eck.zec_cksum;
 376                         eck.zec_cksum = bp->blk_cksum;
 377                 }
 378
 379                 abd_copy_from_buf_off(abd, &zec_magic,
 380                     eck_offset + offsetof(zio_eck_t, zec_magic),
 381                     sizeof (zec_magic));
 382                 abd_copy_from_buf_off(abd, &eck.zec_cksum,
 383                     eck_offset + offsetof(zio_eck_t, zec_cksum),
 384                     sizeof (zio_cksum_t));
 385
 386                 ci->ci_func[0](abd, size, spa->spa_cksum_tmpls[checksum],
 387                     &cksum);
 388                 if (bp != NULL && BP_USES_CRYPT(bp) &&
 389                     BP_GET_TYPE(bp) != DMU_OT_OBJSET)
 390                         zio_checksum_handle_crypt(&cksum, &saved, insecure);
 391
 392                 abd_copy_from_buf_off(abd, &cksum,
 393                     eck_offset + offsetof(zio_eck_t, zec_cksum),
 394                     sizeof (zio_cksum_t));
 395         } else {
 396                 saved = bp->blk_cksum;
 397                 ci->ci_func[0](abd, size, spa->spa_cksum_tmpls[checksum],
 398                     &cksum);
 399                 if (BP_USES_CRYPT(bp) && BP_GET_TYPE(bp) != DMU_OT_OBJSET)
 400                         zio_checksum_handle_crypt(&cksum, &saved, insecure);
 401                 bp->blk_cksum = cksum;
 402         }
 403 }
 404
 405 int
 406 zio_checksum_error_impl(spa_t *spa, const blkptr_t *bp,
 407     enum zio_checksum checksum, abd_t *abd, uint64_t size, uint64_t offset,
 408     zio_bad_cksum_t *info)
 409 {
 410         zio_checksum_info_t *ci = &zio_checksum_table[checksum];
 411         zio_cksum_t actual_cksum, expected_cksum;
 412         zio_eck_t eck;
 413         int byteswap;
 414
 415         if (checksum >= ZIO_CHECKSUM_FUNCTIONS || ci->ci_func[0] == NULL)
 416                 return (SET_ERROR(EINVAL));
 417
 418         zio_checksum_template_init(checksum, spa);
 419
 420         if (ci->ci_flags & ZCHECKSUM_FLAG_EMBEDDED) {
 421                 zio_cksum_t verifier;
 422                 size_t eck_offset;
 423
 424                 if (checksum == ZIO_CHECKSUM_ZILOG2) {
 425                         zil_chain_t zilc;
 426                         uint64_t nused;
 427
 428                         abd_copy_to_buf(&zilc, abd, sizeof (zil_chain_t));
 429
 430                         eck = zilc.zc_eck;
 431                         eck_offset = offsetof(zil_chain_t, zc_eck) +
 432                             offsetof(zio_eck_t, zec_cksum);
 433
 434                         if (eck.zec_magic == ZEC_MAGIC) {
 435                                 nused = zilc.zc_nused;
 436                         } else if (eck.zec_magic == BSWAP_64(ZEC_MAGIC)) {
 437                                 nused = BSWAP_64(zilc.zc_nused);
 438                         } else {
 439                                 return (SET_ERROR(ECKSUM));
 440                         }
 441
 442                         if (nused > size) {
 443                                 return (SET_ERROR(ECKSUM));
 444                         }
 445
 446                         size = P2ROUNDUP_TYPED(nused, ZIL_MIN_BLKSZ, uint64_t);
 447                 } else {
 448                         eck_offset = size - sizeof (zio_eck_t);
 449                         abd_copy_to_buf_off(&eck, abd, eck_offset,
 450                             sizeof (zio_eck_t));
 451                         eck_offset += offsetof(zio_eck_t, zec_cksum);
 452                 }
 453
 454                 if (checksum == ZIO_CHECKSUM_GANG_HEADER)
 455                         zio_checksum_gang_verifier(&verifier, bp);
 456                 else if (checksum == ZIO_CHECKSUM_LABEL)
 457                         zio_checksum_label_verifier(&verifier, offset);
 458                 else
 459                         verifier = bp->blk_cksum;
 460
 461                 byteswap = (eck.zec_magic == BSWAP_64(ZEC_MAGIC));
 462
 463                 if (byteswap)
 464                         byteswap_uint64_array(&verifier, sizeof (zio_cksum_t));
 465
 466                 expected_cksum = eck.zec_cksum;
 467
 468                 abd_copy_from_buf_off(abd, &verifier, eck_offset,
 469                     sizeof (zio_cksum_t));
 470
 471                 ci->ci_func[byteswap](abd, size,
 472                     spa->spa_cksum_tmpls[checksum], &actual_cksum);
 473
 474                 abd_copy_from_buf_off(abd, &expected_cksum, eck_offset,
 475                     sizeof (zio_cksum_t));
 476
 477                 if (byteswap) {
 478                         byteswap_uint64_array(&expected_cksum,
 479                             sizeof (zio_cksum_t));
 480                 }
 481         } else {
 482                 byteswap = BP_SHOULD_BYTESWAP(bp);
 483                 expected_cksum = bp->blk_cksum;
 484                 ci->ci_func[byteswap](abd, size,
 485                     spa->spa_cksum_tmpls[checksum], &actual_cksum);
 486         }
 487
 488         /*
 489          * MAC checksums are a special case since half of this checksum will
 490          * actually be the encryption MAC. This will be verified by the
 491          * decryption process, so we just check the truncated checksum now.
 492          * Objset blocks use embedded MACs so we don't truncate the checksum
 493          * for them.
 494          */
 495         if (bp != NULL && BP_USES_CRYPT(bp) &&
 496             BP_GET_TYPE(bp) != DMU_OT_OBJSET) {
 497                 if (!(ci->ci_flags & ZCHECKSUM_FLAG_DEDUP)) {
 498                         actual_cksum.zc_word[0] ^= actual_cksum.zc_word[2];
 499                         actual_cksum.zc_word[1] ^= actual_cksum.zc_word[3];
 500                 }
 501
 502                 actual_cksum.zc_word[2] = 0;
 503                 actual_cksum.zc_word[3] = 0;
 504                 expected_cksum.zc_word[2] = 0;
 505                 expected_cksum.zc_word[3] = 0;
 506         }
 507
 508         if (info != NULL) {
 509                 info->zbc_expected = expected_cksum;
 510                 info->zbc_actual = actual_cksum;
 511                 info->zbc_checksum_name = ci->ci_name;
 512                 info->zbc_byteswapped = byteswap;
 513                 info->zbc_injected = 0;
 514                 info->zbc_has_cksum = 1;
 515         }
 516
 517         if (!ZIO_CHECKSUM_EQUAL(actual_cksum, expected_cksum))
 518                 return (SET_ERROR(ECKSUM));
 519
 520         return (0);
 521 }
 522
 523 int
 524 zio_checksum_error(zio_t *zio, zio_bad_cksum_t *info)
 525 {
 526         blkptr_t *bp = zio->io_bp;
 527         uint_t checksum = (bp == NULL ? zio->io_prop.zp_checksum :
 528             (BP_IS_GANG(bp) ? ZIO_CHECKSUM_GANG_HEADER : BP_GET_CHECKSUM(bp)));
 529         int error;
 530         uint64_t size = (bp == NULL ? zio->io_size :
 531             (BP_IS_GANG(bp) ? SPA_GANGBLOCKSIZE : BP_GET_PSIZE(bp)));
 532         uint64_t offset = zio->io_offset;
 533         abd_t *data = zio->io_abd;
 534         spa_t *spa = zio->io_spa;
 535
 536         error = zio_checksum_error_impl(spa, bp, checksum, data, size,
 537             offset, info);
 538
 539         if (zio_injection_enabled && error == 0 && zio->io_error == 0) {
 540                 error = zio_handle_fault_injection(zio, ECKSUM);
 541                 if (error != 0)
 542                         info->zbc_injected = 1;
 543         }
 544
 545         return (error);
 546 }
 547
 548 /*
 549  * Called by a spa_t that's about to be deallocated. This steps through
 550  * all of the checksum context templates and deallocates any that were
 551  * initialized using the algorithm-specific template init function.
 552  */
 553 void
 554 zio_checksum_templates_free(spa_t *spa)
 555 {
 556         for (enum zio_checksum checksum = 0;
 557             checksum < ZIO_CHECKSUM_FUNCTIONS; checksum++) {
 558                 if (spa->spa_cksum_tmpls[checksum] != NULL) {
 559                         zio_checksum_info_t *ci = &zio_checksum_table[checksum];
 560
 561                         VERIFY(ci->ci_tmpl_free != NULL);
 562                         ci->ci_tmpl_free(spa->spa_cksum_tmpls[checksum]);
 563                         spa->spa_cksum_tmpls[checksum] = NULL;
 564                 }
 565         }
 566 }