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 (c) 2013, Joyent, Inc. All rights reserved. 25 * Copyright 2013 Saso Kiselkov. All rights reserved. 26 */ 27 28 #include <sys/zfs_context.h> 29 #include <sys/spa.h> 30 #include <sys/spa_impl.h> 31 #include <sys/zio.h> 32 #include <sys/zio_checksum.h> 33 #include <sys/zil.h> 34 #include <sys/abd.h> 35 #include <zfs_fletcher.h> 36 37 /* 38 * Checksum vectors. 39 * 40 * In the SPA, everything is checksummed. We support checksum vectors 41 * for three distinct reasons: 42 * 43 * 1. Different kinds of data need different levels of protection. 44 * For SPA metadata, we always want a very strong checksum. 45 * For user data, we let users make the trade-off between speed 46 * and checksum strength. 47 * 48 * 2. Cryptographic hash and MAC algorithms are an area of active research. 49 * It is likely that in future hash functions will be at least as strong 50 * as current best-of-breed, and may be substantially faster as well. 51 * We want the ability to take advantage of these new hashes as soon as 52 * they become available. 53 * 54 * 3. If someone develops hardware that can compute a strong hash quickly, 55 * we want the ability to take advantage of that hardware. 56 * 57 * Of course, we don't want a checksum upgrade to invalidate existing 58 * data, so we store the checksum *function* in eight bits of the bp. 59 * This gives us room for up to 256 different checksum functions. 60 * 61 * When writing a block, we always checksum it with the latest-and-greatest 62 * checksum function of the appropriate strength. When reading a block, 63 * we compare the expected checksum against the actual checksum, which we 64 * compute via the checksum function specified by BP_GET_CHECKSUM(bp). 65 * 66 * SALTED CHECKSUMS 67 * 68 * To enable the use of less secure hash algorithms with dedup, we 69 * introduce the notion of salted checksums (MACs, really). A salted 70 * checksum is fed both a random 256-bit value (the salt) and the data 71 * to be checksummed. This salt is kept secret (stored on the pool, but 72 * never shown to the user). Thus even if an attacker knew of collision 73 * weaknesses in the hash algorithm, they won't be able to mount a known 74 * plaintext attack on the DDT, since the actual hash value cannot be 75 * known ahead of time. How the salt is used is algorithm-specific 76 * (some might simply prefix it to the data block, others might need to 77 * utilize a full-blown HMAC). On disk the salt is stored in a ZAP 78 * object in the MOS (DMU_POOL_CHECKSUM_SALT). 79 * 80 * CONTEXT TEMPLATES 81 * 82 * Some hashing algorithms need to perform a substantial amount of 83 * initialization work (e.g. salted checksums above may need to pre-hash 84 * the salt) before being able to process data. Performing this 85 * redundant work for each block would be wasteful, so we instead allow 86 * a checksum algorithm to do the work once (the first time it's used) 87 * and then keep this pre-initialized context as a template inside the 88 * spa_t (spa_cksum_tmpls). If the zio_checksum_info_t contains 89 * non-NULL ci_tmpl_init and ci_tmpl_free callbacks, they are used to 90 * construct and destruct the pre-initialized checksum context. The 91 * pre-initialized context is then reused during each checksum 92 * invocation and passed to the checksum function. 93 */ 94 95 /*ARGSUSED*/ 96 static void 97 abd_checksum_off(abd_t *abd, uint64_t size, 98 const void *ctx_template, zio_cksum_t *zcp) 99 { 100 ZIO_SET_CHECKSUM(zcp, 0, 0, 0, 0); 101 } 102 103 /*ARGSUSED*/ 104 void 105 abd_fletcher_2_native(abd_t *abd, uint64_t size, 106 const void *ctx_template, zio_cksum_t *zcp) 107 { 108 fletcher_init(zcp); 109 (void) abd_iterate_func(abd, 0, size, 110 fletcher_2_incremental_native, zcp); 111 } 112 113 /*ARGSUSED*/ 114 void 115 abd_fletcher_2_byteswap(abd_t *abd, uint64_t size, 116 const void *ctx_template, zio_cksum_t *zcp) 117 { 118 fletcher_init(zcp); 119 (void) abd_iterate_func(abd, 0, size, 120 fletcher_2_incremental_byteswap, zcp); 121 } 122 123 static inline void 124 abd_fletcher_4_impl(abd_t *abd, uint64_t size, zio_abd_checksum_data_t *acdp) 125 { 126 fletcher_4_abd_ops.acf_init(acdp); 127 abd_iterate_func(abd, 0, size, fletcher_4_abd_ops.acf_iter, acdp); 128 fletcher_4_abd_ops.acf_fini(acdp); 129 } 130 131 /*ARGSUSED*/ 132 void 133 abd_fletcher_4_native(abd_t *abd, uint64_t size, 134 const void *ctx_template, zio_cksum_t *zcp) 135 { 136 fletcher_4_ctx_t ctx; 137 138 zio_abd_checksum_data_t acd = { 139 .acd_byteorder = ZIO_CHECKSUM_NATIVE, 140 .acd_zcp = zcp, 141 .acd_ctx = &ctx 142 }; 143 144 abd_fletcher_4_impl(abd, size, &acd); 145 146 } 147 148 /*ARGSUSED*/ 149 void 150 abd_fletcher_4_byteswap(abd_t *abd, uint64_t size, 151 const void *ctx_template, zio_cksum_t *zcp) 152 { 153 fletcher_4_ctx_t ctx; 154 155 zio_abd_checksum_data_t acd = { 156 .acd_byteorder = ZIO_CHECKSUM_BYTESWAP, 157 .acd_zcp = zcp, 158 .acd_ctx = &ctx 159 }; 160 161 abd_fletcher_4_impl(abd, size, &acd); 162 } 163 164 zio_checksum_info_t zio_checksum_table[ZIO_CHECKSUM_FUNCTIONS] = { 165 {{NULL, NULL}, NULL, NULL, 0, "inherit"}, 166 {{NULL, NULL}, NULL, NULL, 0, "on"}, 167 {{abd_checksum_off, abd_checksum_off}, 168 NULL, NULL, 0, "off"}, 169 {{abd_checksum_SHA256, abd_checksum_SHA256}, 170 NULL, NULL, ZCHECKSUM_FLAG_METADATA | ZCHECKSUM_FLAG_EMBEDDED, 171 "label"}, 172 {{abd_checksum_SHA256, abd_checksum_SHA256}, 173 NULL, NULL, ZCHECKSUM_FLAG_METADATA | ZCHECKSUM_FLAG_EMBEDDED, 174 "gang_header"}, 175 {{abd_fletcher_2_native, abd_fletcher_2_byteswap}, 176 NULL, NULL, ZCHECKSUM_FLAG_EMBEDDED, "zilog"}, 177 {{abd_fletcher_2_native, abd_fletcher_2_byteswap}, 178 NULL, NULL, 0, "fletcher2"}, 179 {{abd_fletcher_4_native, abd_fletcher_4_byteswap}, 180 NULL, NULL, ZCHECKSUM_FLAG_METADATA, "fletcher4"}, 181 {{abd_checksum_SHA256, abd_checksum_SHA256}, 182 NULL, NULL, ZCHECKSUM_FLAG_METADATA | ZCHECKSUM_FLAG_DEDUP | 183 ZCHECKSUM_FLAG_NOPWRITE, "sha256"}, 184 {{abd_fletcher_4_native, abd_fletcher_4_byteswap}, 185 NULL, NULL, ZCHECKSUM_FLAG_EMBEDDED, "zilog2"}, 186 {{abd_checksum_off, abd_checksum_off}, 187 NULL, NULL, 0, "noparity"}, 188 {{abd_checksum_SHA512_native, abd_checksum_SHA512_byteswap}, 189 NULL, NULL, ZCHECKSUM_FLAG_METADATA | ZCHECKSUM_FLAG_DEDUP | 190 ZCHECKSUM_FLAG_NOPWRITE, "sha512"}, 191 {{abd_checksum_skein_native, abd_checksum_skein_byteswap}, 192 abd_checksum_skein_tmpl_init, abd_checksum_skein_tmpl_free, 193 ZCHECKSUM_FLAG_METADATA | ZCHECKSUM_FLAG_DEDUP | 194 ZCHECKSUM_FLAG_SALTED | ZCHECKSUM_FLAG_NOPWRITE, "skein"}, 195 {{abd_checksum_edonr_native, abd_checksum_edonr_byteswap}, 196 abd_checksum_edonr_tmpl_init, abd_checksum_edonr_tmpl_free, 197 ZCHECKSUM_FLAG_METADATA | ZCHECKSUM_FLAG_SALTED | 198 ZCHECKSUM_FLAG_NOPWRITE, "edonr"}, 199 }; 200 201 /* 202 * The flag corresponding to the "verify" in dedup=[checksum,]verify 203 * must be cleared first, so callers should use ZIO_CHECKSUM_MASK. 204 */ 205 spa_feature_t 206 zio_checksum_to_feature(enum zio_checksum cksum) 207 { 208 VERIFY((cksum & ~ZIO_CHECKSUM_MASK) == 0); 209 210 switch (cksum) { 211 case ZIO_CHECKSUM_SHA512: 212 return (SPA_FEATURE_SHA512); 213 case ZIO_CHECKSUM_SKEIN: 214 return (SPA_FEATURE_SKEIN); 215 case ZIO_CHECKSUM_EDONR: 216 return (SPA_FEATURE_EDONR); 217 } 218 return (SPA_FEATURE_NONE); 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; 341 zio_cksum_t cksum, saved; 342 spa_t *spa = zio->io_spa; 343 boolean_t insecure; 344 345 ASSERT((uint_t)checksum < ZIO_CHECKSUM_FUNCTIONS); 346 ci = &zio_checksum_table[checksum]; 347 ASSERT(ci->ci_func[0] != NULL); 348 insecure = (ci->ci_flags & ZCHECKSUM_FLAG_DEDUP) == 0; 349 350 zio_checksum_template_init(checksum, spa); 351 352 if (ci->ci_flags & ZCHECKSUM_FLAG_EMBEDDED) { 353 zio_eck_t eck; 354 size_t eck_offset; 355 356 bzero(&saved, sizeof (zio_cksum_t)); 357 358 if (checksum == ZIO_CHECKSUM_ZILOG2) { 359 zil_chain_t zilc; 360 abd_copy_to_buf(&zilc, abd, sizeof (zil_chain_t)); 361 362 size = P2ROUNDUP_TYPED(zilc.zc_nused, ZIL_MIN_BLKSZ, 363 uint64_t); 364 eck = zilc.zc_eck; 365 eck_offset = offsetof(zil_chain_t, zc_eck); 366 } else { 367 eck_offset = size - sizeof (zio_eck_t); 368 abd_copy_to_buf_off(&eck, abd, eck_offset, 369 sizeof (zio_eck_t)); 370 } 371 372 if (checksum == ZIO_CHECKSUM_GANG_HEADER) { 373 zio_checksum_gang_verifier(&eck.zec_cksum, bp); 374 } else if (checksum == ZIO_CHECKSUM_LABEL) { 375 zio_checksum_label_verifier(&eck.zec_cksum, offset); 376 } else { 377 saved = eck.zec_cksum; 378 eck.zec_cksum = bp->blk_cksum; 379 } 380 381 abd_copy_from_buf_off(abd, &zec_magic, 382 eck_offset + offsetof(zio_eck_t, zec_magic), 383 sizeof (zec_magic)); 384 abd_copy_from_buf_off(abd, &eck.zec_cksum, 385 eck_offset + offsetof(zio_eck_t, zec_cksum), 386 sizeof (zio_cksum_t)); 387 388 ci->ci_func[0](abd, size, spa->spa_cksum_tmpls[checksum], 389 &cksum); 390 if (bp != NULL && BP_USES_CRYPT(bp) && 391 BP_GET_TYPE(bp) != DMU_OT_OBJSET) 392 zio_checksum_handle_crypt(&cksum, &saved, insecure); 393 394 abd_copy_from_buf_off(abd, &cksum, 395 eck_offset + offsetof(zio_eck_t, zec_cksum), 396 sizeof (zio_cksum_t)); 397 } else { 398 saved = bp->blk_cksum; 399 ci->ci_func[0](abd, size, spa->spa_cksum_tmpls[checksum], 400 &cksum); 401 if (BP_USES_CRYPT(bp) && BP_GET_TYPE(bp) != DMU_OT_OBJSET) 402 zio_checksum_handle_crypt(&cksum, &saved, insecure); 403 bp->blk_cksum = cksum; 404 } 405 } 406 407 int 408 zio_checksum_error_impl(spa_t *spa, const blkptr_t *bp, 409 enum zio_checksum checksum, abd_t *abd, uint64_t size, 410 uint64_t offset, zio_bad_cksum_t *info) 411 { 412 zio_checksum_info_t *ci; 413 zio_cksum_t actual_cksum, expected_cksum; 414 zio_eck_t eck; 415 int byteswap; 416 417 if (checksum >= ZIO_CHECKSUM_FUNCTIONS) 418 return (SET_ERROR(EINVAL)); 419 420 ci = &zio_checksum_table[checksum]; 421 422 if (ci->ci_func[0] == NULL) 423 return (SET_ERROR(EINVAL)); 424 425 zio_checksum_template_init(checksum, spa); 426 427 if (ci->ci_flags & ZCHECKSUM_FLAG_EMBEDDED) { 428 zio_cksum_t verifier; 429 size_t eck_offset; 430 431 if (checksum == ZIO_CHECKSUM_ZILOG2) { 432 zil_chain_t zilc; 433 uint64_t nused; 434 435 abd_copy_to_buf(&zilc, abd, sizeof (zil_chain_t)); 436 437 eck = zilc.zc_eck; 438 eck_offset = offsetof(zil_chain_t, zc_eck) + 439 offsetof(zio_eck_t, zec_cksum); 440 441 if (eck.zec_magic == ZEC_MAGIC) { 442 nused = zilc.zc_nused; 443 } else if (eck.zec_magic == BSWAP_64(ZEC_MAGIC)) { 444 nused = BSWAP_64(zilc.zc_nused); 445 } else { 446 return (SET_ERROR(ECKSUM)); 447 } 448 449 if (nused > size) { 450 return (SET_ERROR(ECKSUM)); 451 } 452 453 size = P2ROUNDUP_TYPED(nused, ZIL_MIN_BLKSZ, uint64_t); 454 } else { 455 eck_offset = size - sizeof (zio_eck_t); 456 abd_copy_to_buf_off(&eck, abd, eck_offset, 457 sizeof (zio_eck_t)); 458 eck_offset += offsetof(zio_eck_t, zec_cksum); 459 } 460 461 if (checksum == ZIO_CHECKSUM_GANG_HEADER) 462 zio_checksum_gang_verifier(&verifier, bp); 463 else if (checksum == ZIO_CHECKSUM_LABEL) 464 zio_checksum_label_verifier(&verifier, offset); 465 else 466 verifier = bp->blk_cksum; 467 468 byteswap = (eck.zec_magic == BSWAP_64(ZEC_MAGIC)); 469 470 if (byteswap) 471 byteswap_uint64_array(&verifier, sizeof (zio_cksum_t)); 472 473 expected_cksum = eck.zec_cksum; 474 475 abd_copy_from_buf_off(abd, &verifier, eck_offset, 476 sizeof (zio_cksum_t)); 477 478 ci->ci_func[byteswap](abd, size, 479 spa->spa_cksum_tmpls[checksum], &actual_cksum); 480 481 abd_copy_from_buf_off(abd, &expected_cksum, eck_offset, 482 sizeof (zio_cksum_t)); 483 484 if (byteswap) { 485 byteswap_uint64_array(&expected_cksum, 486 sizeof (zio_cksum_t)); 487 } 488 } else { 489 byteswap = BP_SHOULD_BYTESWAP(bp); 490 expected_cksum = bp->blk_cksum; 491 ci->ci_func[byteswap](abd, size, 492 spa->spa_cksum_tmpls[checksum], &actual_cksum); 493 } 494 495 /* 496 * MAC checksums are a special case since half of this checksum will 497 * actually be the encryption MAC. This will be verified by the 498 * decryption process, so we just check the truncated checksum now. 499 * Objset blocks use embedded MACs so we don't truncate the checksum 500 * for them. 501 */ 502 if (bp != NULL && BP_USES_CRYPT(bp) && 503 BP_GET_TYPE(bp) != DMU_OT_OBJSET) { 504 if (!(ci->ci_flags & ZCHECKSUM_FLAG_DEDUP)) { 505 actual_cksum.zc_word[0] ^= actual_cksum.zc_word[2]; 506 actual_cksum.zc_word[1] ^= actual_cksum.zc_word[3]; 507 } 508 509 actual_cksum.zc_word[2] = 0; 510 actual_cksum.zc_word[3] = 0; 511 expected_cksum.zc_word[2] = 0; 512 expected_cksum.zc_word[3] = 0; 513 } 514 515 if (info != NULL) { 516 info->zbc_expected = expected_cksum; 517 info->zbc_actual = actual_cksum; 518 info->zbc_checksum_name = ci->ci_name; 519 info->zbc_byteswapped = byteswap; 520 info->zbc_injected = 0; 521 info->zbc_has_cksum = 1; 522 } 523 if (!ZIO_CHECKSUM_EQUAL(actual_cksum, expected_cksum)) 524 return (SET_ERROR(ECKSUM)); 525 526 return (0); 527 } 528 529 int 530 zio_checksum_error(zio_t *zio, zio_bad_cksum_t *info) 531 { 532 blkptr_t *bp = zio->io_bp; 533 uint_t checksum = (bp == NULL ? zio->io_prop.zp_checksum : 534 (BP_IS_GANG(bp) ? ZIO_CHECKSUM_GANG_HEADER : BP_GET_CHECKSUM(bp))); 535 int error; 536 uint64_t size = (bp == NULL ? zio->io_size : 537 (BP_IS_GANG(bp) ? SPA_GANGBLOCKSIZE : BP_GET_PSIZE(bp))); 538 uint64_t offset = zio->io_offset; 539 abd_t *data = zio->io_abd; 540 spa_t *spa = zio->io_spa; 541 542 error = zio_checksum_error_impl(spa, bp, checksum, data, size, 543 offset, info); 544 545 if (zio_injection_enabled && error == 0 && zio->io_error == 0) { 546 error = zio_handle_fault_injection(zio, ECKSUM); 547 if (error != 0) 548 info->zbc_injected = 1; 549 } 550 551 return (error); 552 } 553 554 /* 555 * Called by a spa_t that's about to be deallocated. This steps through 556 * all of the checksum context templates and deallocates any that were 557 * initialized using the algorithm-specific template init function. 558 */ 559 void 560 zio_checksum_templates_free(spa_t *spa) 561 { 562 for (enum zio_checksum checksum = 0; 563 checksum < ZIO_CHECKSUM_FUNCTIONS; checksum++) { 564 if (spa->spa_cksum_tmpls[checksum] != NULL) { 565 zio_checksum_info_t *ci = &zio_checksum_table[checksum]; 566 567 VERIFY(ci->ci_tmpl_free != NULL); 568 ci->ci_tmpl_free(spa->spa_cksum_tmpls[checksum]); 569 spa->spa_cksum_tmpls[checksum] = NULL; 570 } 571 } 572 } 573