xref: /freebsd/sys/contrib/openzfs/module/zfs/zio_checksum.c (revision edf8578117e8844e02c0121147f45e4609b30680)
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 https://opensource.org/licenses/CDDL-1.0.
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 static void
95 abd_checksum_off(abd_t *abd, uint64_t size,
96     const void *ctx_template, zio_cksum_t *zcp)
97 {
98 	(void) abd, (void) size, (void) ctx_template;
99 	ZIO_SET_CHECKSUM(zcp, 0, 0, 0, 0);
100 }
101 
102 static void
103 abd_fletcher_2_native(abd_t *abd, uint64_t size,
104     const void *ctx_template, zio_cksum_t *zcp)
105 {
106 	(void) ctx_template;
107 	fletcher_init(zcp);
108 	(void) abd_iterate_func(abd, 0, size,
109 	    fletcher_2_incremental_native, zcp);
110 }
111 
112 static void
113 abd_fletcher_2_byteswap(abd_t *abd, uint64_t size,
114     const void *ctx_template, zio_cksum_t *zcp)
115 {
116 	(void) ctx_template;
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 void
131 abd_fletcher_4_native(abd_t *abd, uint64_t size,
132     const void *ctx_template, zio_cksum_t *zcp)
133 {
134 	(void) ctx_template;
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 void
148 abd_fletcher_4_byteswap(abd_t *abd, uint64_t size,
149     const void *ctx_template, zio_cksum_t *zcp)
150 {
151 	(void) ctx_template;
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 	{{abd_checksum_blake3_native,	abd_checksum_blake3_byteswap},
199 	    abd_checksum_blake3_tmpl_init, abd_checksum_blake3_tmpl_free,
200 	    ZCHECKSUM_FLAG_METADATA | ZCHECKSUM_FLAG_DEDUP |
201 	    ZCHECKSUM_FLAG_SALTED | ZCHECKSUM_FLAG_NOPWRITE, "blake3"},
202 };
203 
204 /*
205  * The flag corresponding to the "verify" in dedup=[checksum,]verify
206  * must be cleared first, so callers should use ZIO_CHECKSUM_MASK.
207  */
208 spa_feature_t
209 zio_checksum_to_feature(enum zio_checksum cksum)
210 {
211 	VERIFY((cksum & ~ZIO_CHECKSUM_MASK) == 0);
212 
213 	switch (cksum) {
214 	case ZIO_CHECKSUM_BLAKE3:
215 		return (SPA_FEATURE_BLAKE3);
216 	case ZIO_CHECKSUM_SHA512:
217 		return (SPA_FEATURE_SHA512);
218 	case ZIO_CHECKSUM_SKEIN:
219 		return (SPA_FEATURE_SKEIN);
220 	case ZIO_CHECKSUM_EDONR:
221 		return (SPA_FEATURE_EDONR);
222 	default:
223 		return (SPA_FEATURE_NONE);
224 	}
225 }
226 
227 enum zio_checksum
228 zio_checksum_select(enum zio_checksum child, enum zio_checksum parent)
229 {
230 	ASSERT(child < ZIO_CHECKSUM_FUNCTIONS);
231 	ASSERT(parent < ZIO_CHECKSUM_FUNCTIONS);
232 	ASSERT(parent != ZIO_CHECKSUM_INHERIT && parent != ZIO_CHECKSUM_ON);
233 
234 	if (child == ZIO_CHECKSUM_INHERIT)
235 		return (parent);
236 
237 	if (child == ZIO_CHECKSUM_ON)
238 		return (ZIO_CHECKSUM_ON_VALUE);
239 
240 	return (child);
241 }
242 
243 enum zio_checksum
244 zio_checksum_dedup_select(spa_t *spa, enum zio_checksum child,
245     enum zio_checksum parent)
246 {
247 	ASSERT((child & ZIO_CHECKSUM_MASK) < ZIO_CHECKSUM_FUNCTIONS);
248 	ASSERT((parent & ZIO_CHECKSUM_MASK) < ZIO_CHECKSUM_FUNCTIONS);
249 	ASSERT(parent != ZIO_CHECKSUM_INHERIT && parent != ZIO_CHECKSUM_ON);
250 
251 	if (child == ZIO_CHECKSUM_INHERIT)
252 		return (parent);
253 
254 	if (child == ZIO_CHECKSUM_ON)
255 		return (spa_dedup_checksum(spa));
256 
257 	if (child == (ZIO_CHECKSUM_ON | ZIO_CHECKSUM_VERIFY))
258 		return (spa_dedup_checksum(spa) | ZIO_CHECKSUM_VERIFY);
259 
260 	ASSERT((zio_checksum_table[child & ZIO_CHECKSUM_MASK].ci_flags &
261 	    ZCHECKSUM_FLAG_DEDUP) ||
262 	    (child & ZIO_CHECKSUM_VERIFY) || child == ZIO_CHECKSUM_OFF);
263 
264 	return (child);
265 }
266 
267 /*
268  * Set the external verifier for a gang block based on <vdev, offset, txg>,
269  * a tuple which is guaranteed to be unique for the life of the pool.
270  */
271 static void
272 zio_checksum_gang_verifier(zio_cksum_t *zcp, const blkptr_t *bp)
273 {
274 	const dva_t *dva = BP_IDENTITY(bp);
275 	uint64_t txg = BP_PHYSICAL_BIRTH(bp);
276 
277 	ASSERT(BP_IS_GANG(bp));
278 
279 	ZIO_SET_CHECKSUM(zcp, DVA_GET_VDEV(dva), DVA_GET_OFFSET(dva), txg, 0);
280 }
281 
282 /*
283  * Set the external verifier for a label block based on its offset.
284  * The vdev is implicit, and the txg is unknowable at pool open time --
285  * hence the logic in vdev_uberblock_load() to find the most recent copy.
286  */
287 static void
288 zio_checksum_label_verifier(zio_cksum_t *zcp, uint64_t offset)
289 {
290 	ZIO_SET_CHECKSUM(zcp, offset, 0, 0, 0);
291 }
292 
293 /*
294  * Calls the template init function of a checksum which supports context
295  * templates and installs the template into the spa_t.
296  */
297 static void
298 zio_checksum_template_init(enum zio_checksum checksum, spa_t *spa)
299 {
300 	zio_checksum_info_t *ci = &zio_checksum_table[checksum];
301 
302 	if (ci->ci_tmpl_init == NULL)
303 		return;
304 	if (spa->spa_cksum_tmpls[checksum] != NULL)
305 		return;
306 
307 	VERIFY(ci->ci_tmpl_free != NULL);
308 	mutex_enter(&spa->spa_cksum_tmpls_lock);
309 	if (spa->spa_cksum_tmpls[checksum] == NULL) {
310 		spa->spa_cksum_tmpls[checksum] =
311 		    ci->ci_tmpl_init(&spa->spa_cksum_salt);
312 		VERIFY(spa->spa_cksum_tmpls[checksum] != NULL);
313 	}
314 	mutex_exit(&spa->spa_cksum_tmpls_lock);
315 }
316 
317 /* convenience function to update a checksum to accommodate an encryption MAC */
318 static void
319 zio_checksum_handle_crypt(zio_cksum_t *cksum, zio_cksum_t *saved, boolean_t xor)
320 {
321 	/*
322 	 * Weak checksums do not have their entropy spread evenly
323 	 * across the bits of the checksum. Therefore, when truncating
324 	 * a weak checksum we XOR the first 2 words with the last 2 so
325 	 * that we don't "lose" any entropy unnecessarily.
326 	 */
327 	if (xor) {
328 		cksum->zc_word[0] ^= cksum->zc_word[2];
329 		cksum->zc_word[1] ^= cksum->zc_word[3];
330 	}
331 
332 	cksum->zc_word[2] = saved->zc_word[2];
333 	cksum->zc_word[3] = saved->zc_word[3];
334 }
335 
336 /*
337  * Generate the checksum.
338  */
339 void
340 zio_checksum_compute(zio_t *zio, enum zio_checksum checksum,
341     abd_t *abd, uint64_t size)
342 {
343 	static const uint64_t zec_magic = ZEC_MAGIC;
344 	blkptr_t *bp = zio->io_bp;
345 	uint64_t offset = zio->io_offset;
346 	zio_checksum_info_t *ci = &zio_checksum_table[checksum];
347 	zio_cksum_t cksum, saved;
348 	spa_t *spa = zio->io_spa;
349 	boolean_t insecure = (ci->ci_flags & ZCHECKSUM_FLAG_DEDUP) == 0;
350 
351 	ASSERT((uint_t)checksum < ZIO_CHECKSUM_FUNCTIONS);
352 	ASSERT(ci->ci_func[0] != NULL);
353 
354 	zio_checksum_template_init(checksum, spa);
355 
356 	if (ci->ci_flags & ZCHECKSUM_FLAG_EMBEDDED) {
357 		zio_eck_t eck;
358 		size_t eck_offset;
359 
360 		memset(&saved, 0, sizeof (zio_cksum_t));
361 
362 		if (checksum == ZIO_CHECKSUM_ZILOG2) {
363 			zil_chain_t zilc;
364 			abd_copy_to_buf(&zilc, abd, sizeof (zil_chain_t));
365 
366 			size = P2ROUNDUP_TYPED(zilc.zc_nused, ZIL_MIN_BLKSZ,
367 			    uint64_t);
368 			eck = zilc.zc_eck;
369 			eck_offset = offsetof(zil_chain_t, zc_eck);
370 		} else {
371 			eck_offset = size - sizeof (zio_eck_t);
372 			abd_copy_to_buf_off(&eck, abd, eck_offset,
373 			    sizeof (zio_eck_t));
374 		}
375 
376 		if (checksum == ZIO_CHECKSUM_GANG_HEADER) {
377 			zio_checksum_gang_verifier(&eck.zec_cksum, bp);
378 		} else if (checksum == ZIO_CHECKSUM_LABEL) {
379 			zio_checksum_label_verifier(&eck.zec_cksum, offset);
380 		} else {
381 			saved = eck.zec_cksum;
382 			eck.zec_cksum = bp->blk_cksum;
383 		}
384 
385 		abd_copy_from_buf_off(abd, &zec_magic,
386 		    eck_offset + offsetof(zio_eck_t, zec_magic),
387 		    sizeof (zec_magic));
388 		abd_copy_from_buf_off(abd, &eck.zec_cksum,
389 		    eck_offset + offsetof(zio_eck_t, zec_cksum),
390 		    sizeof (zio_cksum_t));
391 
392 		ci->ci_func[0](abd, size, spa->spa_cksum_tmpls[checksum],
393 		    &cksum);
394 		if (bp != NULL && BP_USES_CRYPT(bp) &&
395 		    BP_GET_TYPE(bp) != DMU_OT_OBJSET)
396 			zio_checksum_handle_crypt(&cksum, &saved, insecure);
397 
398 		abd_copy_from_buf_off(abd, &cksum,
399 		    eck_offset + offsetof(zio_eck_t, zec_cksum),
400 		    sizeof (zio_cksum_t));
401 	} else {
402 		saved = bp->blk_cksum;
403 		ci->ci_func[0](abd, size, spa->spa_cksum_tmpls[checksum],
404 		    &cksum);
405 		if (BP_USES_CRYPT(bp) && BP_GET_TYPE(bp) != DMU_OT_OBJSET)
406 			zio_checksum_handle_crypt(&cksum, &saved, insecure);
407 		bp->blk_cksum = cksum;
408 	}
409 }
410 
411 int
412 zio_checksum_error_impl(spa_t *spa, const blkptr_t *bp,
413     enum zio_checksum checksum, abd_t *abd, uint64_t size, uint64_t offset,
414     zio_bad_cksum_t *info)
415 {
416 	zio_checksum_info_t *ci = &zio_checksum_table[checksum];
417 	zio_cksum_t actual_cksum, expected_cksum;
418 	zio_eck_t eck;
419 	int byteswap;
420 
421 	if (checksum >= ZIO_CHECKSUM_FUNCTIONS || ci->ci_func[0] == NULL)
422 		return (SET_ERROR(EINVAL));
423 
424 	zio_checksum_template_init(checksum, spa);
425 
426 	IMPLY(bp == NULL, ci->ci_flags & ZCHECKSUM_FLAG_EMBEDDED);
427 	IMPLY(bp == NULL, checksum == ZIO_CHECKSUM_LABEL);
428 
429 	if (ci->ci_flags & ZCHECKSUM_FLAG_EMBEDDED) {
430 		zio_cksum_t verifier;
431 		size_t eck_offset;
432 
433 		if (checksum == ZIO_CHECKSUM_ZILOG2) {
434 			zil_chain_t zilc;
435 			uint64_t nused;
436 
437 			abd_copy_to_buf(&zilc, abd, sizeof (zil_chain_t));
438 
439 			eck = zilc.zc_eck;
440 			eck_offset = offsetof(zil_chain_t, zc_eck) +
441 			    offsetof(zio_eck_t, zec_cksum);
442 
443 			if (eck.zec_magic == ZEC_MAGIC) {
444 				nused = zilc.zc_nused;
445 			} else if (eck.zec_magic == BSWAP_64(ZEC_MAGIC)) {
446 				nused = BSWAP_64(zilc.zc_nused);
447 			} else {
448 				return (SET_ERROR(ECKSUM));
449 			}
450 
451 			if (nused > size) {
452 				return (SET_ERROR(ECKSUM));
453 			}
454 
455 			size = P2ROUNDUP_TYPED(nused, ZIL_MIN_BLKSZ, uint64_t);
456 		} else {
457 			eck_offset = size - sizeof (zio_eck_t);
458 			abd_copy_to_buf_off(&eck, abd, eck_offset,
459 			    sizeof (zio_eck_t));
460 			eck_offset += offsetof(zio_eck_t, zec_cksum);
461 		}
462 
463 		if (checksum == ZIO_CHECKSUM_GANG_HEADER)
464 			zio_checksum_gang_verifier(&verifier, bp);
465 		else if (checksum == ZIO_CHECKSUM_LABEL)
466 			zio_checksum_label_verifier(&verifier, offset);
467 		else
468 			verifier = bp->blk_cksum;
469 
470 		byteswap = (eck.zec_magic == BSWAP_64(ZEC_MAGIC));
471 
472 		if (byteswap)
473 			byteswap_uint64_array(&verifier, sizeof (zio_cksum_t));
474 
475 		expected_cksum = eck.zec_cksum;
476 
477 		abd_copy_from_buf_off(abd, &verifier, eck_offset,
478 		    sizeof (zio_cksum_t));
479 
480 		ci->ci_func[byteswap](abd, size,
481 		    spa->spa_cksum_tmpls[checksum], &actual_cksum);
482 
483 		abd_copy_from_buf_off(abd, &expected_cksum, eck_offset,
484 		    sizeof (zio_cksum_t));
485 
486 		if (byteswap) {
487 			byteswap_uint64_array(&expected_cksum,
488 			    sizeof (zio_cksum_t));
489 		}
490 	} else {
491 		byteswap = BP_SHOULD_BYTESWAP(bp);
492 		expected_cksum = bp->blk_cksum;
493 		ci->ci_func[byteswap](abd, size,
494 		    spa->spa_cksum_tmpls[checksum], &actual_cksum);
495 	}
496 
497 	/*
498 	 * MAC checksums are a special case since half of this checksum will
499 	 * actually be the encryption MAC. This will be verified by the
500 	 * decryption process, so we just check the truncated checksum now.
501 	 * Objset blocks use embedded MACs so we don't truncate the checksum
502 	 * for them.
503 	 */
504 	if (bp != NULL && BP_USES_CRYPT(bp) &&
505 	    BP_GET_TYPE(bp) != DMU_OT_OBJSET) {
506 		if (!(ci->ci_flags & ZCHECKSUM_FLAG_DEDUP)) {
507 			actual_cksum.zc_word[0] ^= actual_cksum.zc_word[2];
508 			actual_cksum.zc_word[1] ^= actual_cksum.zc_word[3];
509 		}
510 
511 		actual_cksum.zc_word[2] = 0;
512 		actual_cksum.zc_word[3] = 0;
513 		expected_cksum.zc_word[2] = 0;
514 		expected_cksum.zc_word[3] = 0;
515 	}
516 
517 	if (info != NULL) {
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 
524 	if (!ZIO_CHECKSUM_EQUAL(actual_cksum, expected_cksum))
525 		return (SET_ERROR(ECKSUM));
526 
527 	return (0);
528 }
529 
530 int
531 zio_checksum_error(zio_t *zio, zio_bad_cksum_t *info)
532 {
533 	blkptr_t *bp = zio->io_bp;
534 	uint_t checksum = (bp == NULL ? zio->io_prop.zp_checksum :
535 	    (BP_IS_GANG(bp) ? ZIO_CHECKSUM_GANG_HEADER : BP_GET_CHECKSUM(bp)));
536 	int error;
537 	uint64_t size = (bp == NULL ? zio->io_size :
538 	    (BP_IS_GANG(bp) ? SPA_GANGBLOCKSIZE : BP_GET_PSIZE(bp)));
539 	uint64_t offset = zio->io_offset;
540 	abd_t *data = zio->io_abd;
541 	spa_t *spa = zio->io_spa;
542 
543 	error = zio_checksum_error_impl(spa, bp, checksum, data, size,
544 	    offset, info);
545 
546 	if (zio_injection_enabled && error == 0 && zio->io_error == 0) {
547 		error = zio_handle_fault_injection(zio, ECKSUM);
548 		if (error != 0)
549 			info->zbc_injected = 1;
550 	}
551 
552 	return (error);
553 }
554 
555 /*
556  * Called by a spa_t that's about to be deallocated. This steps through
557  * all of the checksum context templates and deallocates any that were
558  * initialized using the algorithm-specific template init function.
559  */
560 void
561 zio_checksum_templates_free(spa_t *spa)
562 {
563 	for (enum zio_checksum checksum = 0;
564 	    checksum < ZIO_CHECKSUM_FUNCTIONS; checksum++) {
565 		if (spa->spa_cksum_tmpls[checksum] != NULL) {
566 			zio_checksum_info_t *ci = &zio_checksum_table[checksum];
567 
568 			VERIFY(ci->ci_tmpl_free != NULL);
569 			ci->ci_tmpl_free(spa->spa_cksum_tmpls[checksum]);
570 			spa->spa_cksum_tmpls[checksum] = NULL;
571 		}
572 	}
573 }
574