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.
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.
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]
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2011, 2020 by Delphix. All rights reserved.
24 * Copyright (c) 2011 Nexenta Systems, Inc. All rights reserved.
25 * Copyright (c) 2017, Intel Corporation.
26 * Copyright (c) 2019, Klara Inc.
27 * Copyright (c) 2019, Allan Jude
28 * Copyright (c) 2021, Datto, Inc.
31 #include <sys/sysmacros.h>
32 #include <sys/zfs_context.h>
33 #include <sys/fm/fs/zfs.h>
36 #include <sys/spa_impl.h>
37 #include <sys/vdev_impl.h>
38 #include <sys/vdev_trim.h>
39 #include <sys/zio_impl.h>
40 #include <sys/zio_compress.h>
41 #include <sys/zio_checksum.h>
42 #include <sys/dmu_objset.h>
45 #include <sys/blkptr.h>
46 #include <sys/zfeature.h>
47 #include <sys/dsl_scan.h>
48 #include <sys/metaslab_impl.h>
50 #include <sys/trace_zfs.h>
52 #include <sys/dsl_crypt.h>
56 * ==========================================================================
57 * I/O type descriptions
58 * ==========================================================================
60 const char *const zio_type_name[ZIO_TYPES] = {
62 * Note: Linux kernel thread name length is limited
63 * so these names will differ from upstream open zfs.
65 "z_null", "z_rd", "z_wr", "z_fr", "z_cl", "z_ioctl", "z_trim"
68 int zio_dva_throttle_enabled = B_TRUE;
69 static int zio_deadman_log_all = B_FALSE;
72 * ==========================================================================
74 * ==========================================================================
76 static kmem_cache_t *zio_cache;
77 static kmem_cache_t *zio_link_cache;
78 kmem_cache_t *zio_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT];
79 kmem_cache_t *zio_data_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT];
80 #if defined(ZFS_DEBUG) && !defined(_KERNEL)
81 static uint64_t zio_buf_cache_allocs[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT];
82 static uint64_t zio_buf_cache_frees[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT];
85 /* Mark IOs as "slow" if they take longer than 30 seconds */
86 static int zio_slow_io_ms = (30 * MILLISEC);
88 #define BP_SPANB(indblkshift, level) \
89 (((uint64_t)1) << ((level) * ((indblkshift) - SPA_BLKPTRSHIFT)))
90 #define COMPARE_META_LEVEL 0x80000000ul
92 * The following actions directly effect the spa's sync-to-convergence logic.
93 * The values below define the sync pass when we start performing the action.
94 * Care should be taken when changing these values as they directly impact
95 * spa_sync() performance. Tuning these values may introduce subtle performance
96 * pathologies and should only be done in the context of performance analysis.
97 * These tunables will eventually be removed and replaced with #defines once
98 * enough analysis has been done to determine optimal values.
100 * The 'zfs_sync_pass_deferred_free' pass must be greater than 1 to ensure that
101 * regular blocks are not deferred.
103 * Starting in sync pass 8 (zfs_sync_pass_dont_compress), we disable
104 * compression (including of metadata). In practice, we don't have this
105 * many sync passes, so this has no effect.
107 * The original intent was that disabling compression would help the sync
108 * passes to converge. However, in practice disabling compression increases
109 * the average number of sync passes, because when we turn compression off, a
110 * lot of block's size will change and thus we have to re-allocate (not
111 * overwrite) them. It also increases the number of 128KB allocations (e.g.
112 * for indirect blocks and spacemaps) because these will not be compressed.
113 * The 128K allocations are especially detrimental to performance on highly
114 * fragmented systems, which may have very few free segments of this size,
115 * and may need to load new metaslabs to satisfy 128K allocations.
117 int zfs_sync_pass_deferred_free = 2; /* defer frees starting in this pass */
118 static int zfs_sync_pass_dont_compress = 8; /* don't compress s. i. t. p. */
119 static int zfs_sync_pass_rewrite = 2; /* rewrite new bps s. i. t. p. */
122 * An allocating zio is one that either currently has the DVA allocate
123 * stage set or will have it later in its lifetime.
125 #define IO_IS_ALLOCATING(zio) ((zio)->io_orig_pipeline & ZIO_STAGE_DVA_ALLOCATE)
128 * Enable smaller cores by excluding metadata
129 * allocations as well.
131 int zio_exclude_metadata = 0;
132 static int zio_requeue_io_start_cut_in_line = 1;
135 static const int zio_buf_debug_limit = 16384;
137 static const int zio_buf_debug_limit = 0;
140 static inline void __zio_execute(zio_t *zio);
142 static void zio_taskq_dispatch(zio_t *, zio_taskq_type_t, boolean_t);
149 zio_cache = kmem_cache_create("zio_cache",
150 sizeof (zio_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
151 zio_link_cache = kmem_cache_create("zio_link_cache",
152 sizeof (zio_link_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
155 * For small buffers, we want a cache for each multiple of
156 * SPA_MINBLOCKSIZE. For larger buffers, we want a cache
157 * for each quarter-power of 2.
159 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) {
160 size_t size = (c + 1) << SPA_MINBLOCKSHIFT;
163 size_t data_cflags, cflags;
165 data_cflags = KMC_NODEBUG;
166 cflags = (zio_exclude_metadata || size > zio_buf_debug_limit) ?
169 #if defined(_ILP32) && defined(_KERNEL)
171 * Cache size limited to 1M on 32-bit platforms until ARC
172 * buffers no longer require virtual address space.
174 if (size > zfs_max_recordsize)
183 * If we are using watchpoints, put each buffer on its own page,
184 * to eliminate the performance overhead of trapping to the
185 * kernel when modifying a non-watched buffer that shares the
186 * page with a watched buffer.
188 if (arc_watch && !IS_P2ALIGNED(size, PAGESIZE))
191 * Here's the problem - on 4K native devices in userland on
192 * Linux using O_DIRECT, buffers must be 4K aligned or I/O
193 * will fail with EINVAL, causing zdb (and others) to coredump.
194 * Since userland probably doesn't need optimized buffer caches,
195 * we just force 4K alignment on everything.
197 align = 8 * SPA_MINBLOCKSIZE;
199 if (size < PAGESIZE) {
200 align = SPA_MINBLOCKSIZE;
201 } else if (IS_P2ALIGNED(size, p2 >> 2)) {
208 if (cflags == data_cflags) {
210 * Resulting kmem caches would be identical.
211 * Save memory by creating only one.
213 (void) snprintf(name, sizeof (name),
214 "zio_buf_comb_%lu", (ulong_t)size);
215 zio_buf_cache[c] = kmem_cache_create(name,
216 size, align, NULL, NULL, NULL, NULL, NULL,
218 zio_data_buf_cache[c] = zio_buf_cache[c];
221 (void) snprintf(name, sizeof (name), "zio_buf_%lu",
223 zio_buf_cache[c] = kmem_cache_create(name, size,
224 align, NULL, NULL, NULL, NULL, NULL, cflags);
226 (void) snprintf(name, sizeof (name), "zio_data_buf_%lu",
228 zio_data_buf_cache[c] = kmem_cache_create(name, size,
229 align, NULL, NULL, NULL, NULL, NULL, data_cflags);
234 ASSERT(zio_buf_cache[c] != NULL);
235 if (zio_buf_cache[c - 1] == NULL)
236 zio_buf_cache[c - 1] = zio_buf_cache[c];
238 ASSERT(zio_data_buf_cache[c] != NULL);
239 if (zio_data_buf_cache[c - 1] == NULL)
240 zio_data_buf_cache[c - 1] = zio_data_buf_cache[c];
251 size_t n = SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT;
253 #if defined(ZFS_DEBUG) && !defined(_KERNEL)
254 for (size_t i = 0; i < n; i++) {
255 if (zio_buf_cache_allocs[i] != zio_buf_cache_frees[i])
256 (void) printf("zio_fini: [%d] %llu != %llu\n",
257 (int)((i + 1) << SPA_MINBLOCKSHIFT),
258 (long long unsigned)zio_buf_cache_allocs[i],
259 (long long unsigned)zio_buf_cache_frees[i]);
264 * The same kmem cache can show up multiple times in both zio_buf_cache
265 * and zio_data_buf_cache. Do a wasteful but trivially correct scan to
268 for (size_t i = 0; i < n; i++) {
269 kmem_cache_t *cache = zio_buf_cache[i];
272 for (size_t j = i; j < n; j++) {
273 if (cache == zio_buf_cache[j])
274 zio_buf_cache[j] = NULL;
275 if (cache == zio_data_buf_cache[j])
276 zio_data_buf_cache[j] = NULL;
278 kmem_cache_destroy(cache);
281 for (size_t i = 0; i < n; i++) {
282 kmem_cache_t *cache = zio_data_buf_cache[i];
285 for (size_t j = i; j < n; j++) {
286 if (cache == zio_data_buf_cache[j])
287 zio_data_buf_cache[j] = NULL;
289 kmem_cache_destroy(cache);
292 for (size_t i = 0; i < n; i++) {
293 VERIFY3P(zio_buf_cache[i], ==, NULL);
294 VERIFY3P(zio_data_buf_cache[i], ==, NULL);
297 kmem_cache_destroy(zio_link_cache);
298 kmem_cache_destroy(zio_cache);
306 * ==========================================================================
307 * Allocate and free I/O buffers
308 * ==========================================================================
312 * Use zio_buf_alloc to allocate ZFS metadata. This data will appear in a
313 * crashdump if the kernel panics, so use it judiciously. Obviously, it's
314 * useful to inspect ZFS metadata, but if possible, we should avoid keeping
315 * excess / transient data in-core during a crashdump.
318 zio_buf_alloc(size_t size)
320 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
322 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
323 #if defined(ZFS_DEBUG) && !defined(_KERNEL)
324 atomic_add_64(&zio_buf_cache_allocs[c], 1);
327 return (kmem_cache_alloc(zio_buf_cache[c], KM_PUSHPAGE));
331 * Use zio_data_buf_alloc to allocate data. The data will not appear in a
332 * crashdump if the kernel panics. This exists so that we will limit the amount
333 * of ZFS data that shows up in a kernel crashdump. (Thus reducing the amount
334 * of kernel heap dumped to disk when the kernel panics)
337 zio_data_buf_alloc(size_t size)
339 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
341 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
343 return (kmem_cache_alloc(zio_data_buf_cache[c], KM_PUSHPAGE));
347 zio_buf_free(void *buf, size_t size)
349 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
351 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
352 #if defined(ZFS_DEBUG) && !defined(_KERNEL)
353 atomic_add_64(&zio_buf_cache_frees[c], 1);
356 kmem_cache_free(zio_buf_cache[c], buf);
360 zio_data_buf_free(void *buf, size_t size)
362 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
364 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
366 kmem_cache_free(zio_data_buf_cache[c], buf);
370 zio_abd_free(void *abd, size_t size)
373 abd_free((abd_t *)abd);
377 * ==========================================================================
378 * Push and pop I/O transform buffers
379 * ==========================================================================
382 zio_push_transform(zio_t *zio, abd_t *data, uint64_t size, uint64_t bufsize,
383 zio_transform_func_t *transform)
385 zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP);
387 zt->zt_orig_abd = zio->io_abd;
388 zt->zt_orig_size = zio->io_size;
389 zt->zt_bufsize = bufsize;
390 zt->zt_transform = transform;
392 zt->zt_next = zio->io_transform_stack;
393 zio->io_transform_stack = zt;
400 zio_pop_transforms(zio_t *zio)
404 while ((zt = zio->io_transform_stack) != NULL) {
405 if (zt->zt_transform != NULL)
406 zt->zt_transform(zio,
407 zt->zt_orig_abd, zt->zt_orig_size);
409 if (zt->zt_bufsize != 0)
410 abd_free(zio->io_abd);
412 zio->io_abd = zt->zt_orig_abd;
413 zio->io_size = zt->zt_orig_size;
414 zio->io_transform_stack = zt->zt_next;
416 kmem_free(zt, sizeof (zio_transform_t));
421 * ==========================================================================
422 * I/O transform callbacks for subblocks, decompression, and decryption
423 * ==========================================================================
426 zio_subblock(zio_t *zio, abd_t *data, uint64_t size)
428 ASSERT(zio->io_size > size);
430 if (zio->io_type == ZIO_TYPE_READ)
431 abd_copy(data, zio->io_abd, size);
435 zio_decompress(zio_t *zio, abd_t *data, uint64_t size)
437 if (zio->io_error == 0) {
438 void *tmp = abd_borrow_buf(data, size);
439 int ret = zio_decompress_data(BP_GET_COMPRESS(zio->io_bp),
440 zio->io_abd, tmp, zio->io_size, size,
441 &zio->io_prop.zp_complevel);
442 abd_return_buf_copy(data, tmp, size);
444 if (zio_injection_enabled && ret == 0)
445 ret = zio_handle_fault_injection(zio, EINVAL);
448 zio->io_error = SET_ERROR(EIO);
453 zio_decrypt(zio_t *zio, abd_t *data, uint64_t size)
457 blkptr_t *bp = zio->io_bp;
458 spa_t *spa = zio->io_spa;
459 uint64_t dsobj = zio->io_bookmark.zb_objset;
460 uint64_t lsize = BP_GET_LSIZE(bp);
461 dmu_object_type_t ot = BP_GET_TYPE(bp);
462 uint8_t salt[ZIO_DATA_SALT_LEN];
463 uint8_t iv[ZIO_DATA_IV_LEN];
464 uint8_t mac[ZIO_DATA_MAC_LEN];
465 boolean_t no_crypt = B_FALSE;
467 ASSERT(BP_USES_CRYPT(bp));
468 ASSERT3U(size, !=, 0);
470 if (zio->io_error != 0)
474 * Verify the cksum of MACs stored in an indirect bp. It will always
475 * be possible to verify this since it does not require an encryption
478 if (BP_HAS_INDIRECT_MAC_CKSUM(bp)) {
479 zio_crypt_decode_mac_bp(bp, mac);
481 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF) {
483 * We haven't decompressed the data yet, but
484 * zio_crypt_do_indirect_mac_checksum() requires
485 * decompressed data to be able to parse out the MACs
486 * from the indirect block. We decompress it now and
487 * throw away the result after we are finished.
489 tmp = zio_buf_alloc(lsize);
490 ret = zio_decompress_data(BP_GET_COMPRESS(bp),
491 zio->io_abd, tmp, zio->io_size, lsize,
492 &zio->io_prop.zp_complevel);
494 ret = SET_ERROR(EIO);
497 ret = zio_crypt_do_indirect_mac_checksum(B_FALSE,
498 tmp, lsize, BP_SHOULD_BYTESWAP(bp), mac);
499 zio_buf_free(tmp, lsize);
501 ret = zio_crypt_do_indirect_mac_checksum_abd(B_FALSE,
502 zio->io_abd, size, BP_SHOULD_BYTESWAP(bp), mac);
504 abd_copy(data, zio->io_abd, size);
506 if (zio_injection_enabled && ot != DMU_OT_DNODE && ret == 0) {
507 ret = zio_handle_decrypt_injection(spa,
508 &zio->io_bookmark, ot, ECKSUM);
517 * If this is an authenticated block, just check the MAC. It would be
518 * nice to separate this out into its own flag, but for the moment
519 * enum zio_flag is out of bits.
521 if (BP_IS_AUTHENTICATED(bp)) {
522 if (ot == DMU_OT_OBJSET) {
523 ret = spa_do_crypt_objset_mac_abd(B_FALSE, spa,
524 dsobj, zio->io_abd, size, BP_SHOULD_BYTESWAP(bp));
526 zio_crypt_decode_mac_bp(bp, mac);
527 ret = spa_do_crypt_mac_abd(B_FALSE, spa, dsobj,
528 zio->io_abd, size, mac);
529 if (zio_injection_enabled && ret == 0) {
530 ret = zio_handle_decrypt_injection(spa,
531 &zio->io_bookmark, ot, ECKSUM);
534 abd_copy(data, zio->io_abd, size);
542 zio_crypt_decode_params_bp(bp, salt, iv);
544 if (ot == DMU_OT_INTENT_LOG) {
545 tmp = abd_borrow_buf_copy(zio->io_abd, sizeof (zil_chain_t));
546 zio_crypt_decode_mac_zil(tmp, mac);
547 abd_return_buf(zio->io_abd, tmp, sizeof (zil_chain_t));
549 zio_crypt_decode_mac_bp(bp, mac);
552 ret = spa_do_crypt_abd(B_FALSE, spa, &zio->io_bookmark, BP_GET_TYPE(bp),
553 BP_GET_DEDUP(bp), BP_SHOULD_BYTESWAP(bp), salt, iv, mac, size, data,
554 zio->io_abd, &no_crypt);
556 abd_copy(data, zio->io_abd, size);
564 /* assert that the key was found unless this was speculative */
565 ASSERT(ret != EACCES || (zio->io_flags & ZIO_FLAG_SPECULATIVE));
568 * If there was a decryption / authentication error return EIO as
569 * the io_error. If this was not a speculative zio, create an ereport.
572 zio->io_error = SET_ERROR(EIO);
573 if ((zio->io_flags & ZIO_FLAG_SPECULATIVE) == 0) {
574 spa_log_error(spa, &zio->io_bookmark);
575 (void) zfs_ereport_post(FM_EREPORT_ZFS_AUTHENTICATION,
576 spa, NULL, &zio->io_bookmark, zio, 0);
584 * ==========================================================================
585 * I/O parent/child relationships and pipeline interlocks
586 * ==========================================================================
589 zio_walk_parents(zio_t *cio, zio_link_t **zl)
591 list_t *pl = &cio->io_parent_list;
593 *zl = (*zl == NULL) ? list_head(pl) : list_next(pl, *zl);
597 ASSERT((*zl)->zl_child == cio);
598 return ((*zl)->zl_parent);
602 zio_walk_children(zio_t *pio, zio_link_t **zl)
604 list_t *cl = &pio->io_child_list;
606 ASSERT(MUTEX_HELD(&pio->io_lock));
608 *zl = (*zl == NULL) ? list_head(cl) : list_next(cl, *zl);
612 ASSERT((*zl)->zl_parent == pio);
613 return ((*zl)->zl_child);
617 zio_unique_parent(zio_t *cio)
619 zio_link_t *zl = NULL;
620 zio_t *pio = zio_walk_parents(cio, &zl);
622 VERIFY3P(zio_walk_parents(cio, &zl), ==, NULL);
627 zio_add_child(zio_t *pio, zio_t *cio)
629 zio_link_t *zl = kmem_cache_alloc(zio_link_cache, KM_SLEEP);
632 * Logical I/Os can have logical, gang, or vdev children.
633 * Gang I/Os can have gang or vdev children.
634 * Vdev I/Os can only have vdev children.
635 * The following ASSERT captures all of these constraints.
637 ASSERT3S(cio->io_child_type, <=, pio->io_child_type);
642 mutex_enter(&pio->io_lock);
643 mutex_enter(&cio->io_lock);
645 ASSERT(pio->io_state[ZIO_WAIT_DONE] == 0);
647 for (int w = 0; w < ZIO_WAIT_TYPES; w++)
648 pio->io_children[cio->io_child_type][w] += !cio->io_state[w];
650 list_insert_head(&pio->io_child_list, zl);
651 list_insert_head(&cio->io_parent_list, zl);
653 pio->io_child_count++;
654 cio->io_parent_count++;
656 mutex_exit(&cio->io_lock);
657 mutex_exit(&pio->io_lock);
661 zio_remove_child(zio_t *pio, zio_t *cio, zio_link_t *zl)
663 ASSERT(zl->zl_parent == pio);
664 ASSERT(zl->zl_child == cio);
666 mutex_enter(&pio->io_lock);
667 mutex_enter(&cio->io_lock);
669 list_remove(&pio->io_child_list, zl);
670 list_remove(&cio->io_parent_list, zl);
672 pio->io_child_count--;
673 cio->io_parent_count--;
675 mutex_exit(&cio->io_lock);
676 mutex_exit(&pio->io_lock);
677 kmem_cache_free(zio_link_cache, zl);
681 zio_wait_for_children(zio_t *zio, uint8_t childbits, enum zio_wait_type wait)
683 boolean_t waiting = B_FALSE;
685 mutex_enter(&zio->io_lock);
686 ASSERT(zio->io_stall == NULL);
687 for (int c = 0; c < ZIO_CHILD_TYPES; c++) {
688 if (!(ZIO_CHILD_BIT_IS_SET(childbits, c)))
691 uint64_t *countp = &zio->io_children[c][wait];
694 ASSERT3U(zio->io_stage, !=, ZIO_STAGE_OPEN);
695 zio->io_stall = countp;
700 mutex_exit(&zio->io_lock);
704 __attribute__((always_inline))
706 zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait,
707 zio_t **next_to_executep)
709 uint64_t *countp = &pio->io_children[zio->io_child_type][wait];
710 int *errorp = &pio->io_child_error[zio->io_child_type];
712 mutex_enter(&pio->io_lock);
713 if (zio->io_error && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE))
714 *errorp = zio_worst_error(*errorp, zio->io_error);
715 pio->io_reexecute |= zio->io_reexecute;
716 ASSERT3U(*countp, >, 0);
720 if (*countp == 0 && pio->io_stall == countp) {
721 zio_taskq_type_t type =
722 pio->io_stage < ZIO_STAGE_VDEV_IO_START ? ZIO_TASKQ_ISSUE :
724 pio->io_stall = NULL;
725 mutex_exit(&pio->io_lock);
728 * If we can tell the caller to execute this parent next, do
729 * so. Otherwise dispatch the parent zio as its own task.
731 * Having the caller execute the parent when possible reduces
732 * locking on the zio taskq's, reduces context switch
733 * overhead, and has no recursion penalty. Note that one
734 * read from disk typically causes at least 3 zio's: a
735 * zio_null(), the logical zio_read(), and then a physical
736 * zio. When the physical ZIO completes, we are able to call
737 * zio_done() on all 3 of these zio's from one invocation of
738 * zio_execute() by returning the parent back to
739 * zio_execute(). Since the parent isn't executed until this
740 * thread returns back to zio_execute(), the caller should do
743 * In other cases, dispatching the parent prevents
744 * overflowing the stack when we have deeply nested
745 * parent-child relationships, as we do with the "mega zio"
746 * of writes for spa_sync(), and the chain of ZIL blocks.
748 if (next_to_executep != NULL && *next_to_executep == NULL) {
749 *next_to_executep = pio;
751 zio_taskq_dispatch(pio, type, B_FALSE);
754 mutex_exit(&pio->io_lock);
759 zio_inherit_child_errors(zio_t *zio, enum zio_child c)
761 if (zio->io_child_error[c] != 0 && zio->io_error == 0)
762 zio->io_error = zio->io_child_error[c];
766 zio_bookmark_compare(const void *x1, const void *x2)
768 const zio_t *z1 = x1;
769 const zio_t *z2 = x2;
771 if (z1->io_bookmark.zb_objset < z2->io_bookmark.zb_objset)
773 if (z1->io_bookmark.zb_objset > z2->io_bookmark.zb_objset)
776 if (z1->io_bookmark.zb_object < z2->io_bookmark.zb_object)
778 if (z1->io_bookmark.zb_object > z2->io_bookmark.zb_object)
781 if (z1->io_bookmark.zb_level < z2->io_bookmark.zb_level)
783 if (z1->io_bookmark.zb_level > z2->io_bookmark.zb_level)
786 if (z1->io_bookmark.zb_blkid < z2->io_bookmark.zb_blkid)
788 if (z1->io_bookmark.zb_blkid > z2->io_bookmark.zb_blkid)
800 * ==========================================================================
801 * Create the various types of I/O (read, write, free, etc)
802 * ==========================================================================
805 zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp,
806 abd_t *data, uint64_t lsize, uint64_t psize, zio_done_func_t *done,
807 void *private, zio_type_t type, zio_priority_t priority,
808 enum zio_flag flags, vdev_t *vd, uint64_t offset,
809 const zbookmark_phys_t *zb, enum zio_stage stage,
810 enum zio_stage pipeline)
814 IMPLY(type != ZIO_TYPE_TRIM, psize <= SPA_MAXBLOCKSIZE);
815 ASSERT(P2PHASE(psize, SPA_MINBLOCKSIZE) == 0);
816 ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0);
818 ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER));
819 ASSERT(!bp || !(flags & ZIO_FLAG_CONFIG_WRITER));
820 ASSERT(vd || stage == ZIO_STAGE_OPEN);
822 IMPLY(lsize != psize, (flags & ZIO_FLAG_RAW_COMPRESS) != 0);
824 zio = kmem_cache_alloc(zio_cache, KM_SLEEP);
825 bzero(zio, sizeof (zio_t));
827 mutex_init(&zio->io_lock, NULL, MUTEX_NOLOCKDEP, NULL);
828 cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL);
830 list_create(&zio->io_parent_list, sizeof (zio_link_t),
831 offsetof(zio_link_t, zl_parent_node));
832 list_create(&zio->io_child_list, sizeof (zio_link_t),
833 offsetof(zio_link_t, zl_child_node));
834 metaslab_trace_init(&zio->io_alloc_list);
837 zio->io_child_type = ZIO_CHILD_VDEV;
838 else if (flags & ZIO_FLAG_GANG_CHILD)
839 zio->io_child_type = ZIO_CHILD_GANG;
840 else if (flags & ZIO_FLAG_DDT_CHILD)
841 zio->io_child_type = ZIO_CHILD_DDT;
843 zio->io_child_type = ZIO_CHILD_LOGICAL;
846 zio->io_bp = (blkptr_t *)bp;
847 zio->io_bp_copy = *bp;
848 zio->io_bp_orig = *bp;
849 if (type != ZIO_TYPE_WRITE ||
850 zio->io_child_type == ZIO_CHILD_DDT)
851 zio->io_bp = &zio->io_bp_copy; /* so caller can free */
852 if (zio->io_child_type == ZIO_CHILD_LOGICAL)
853 zio->io_logical = zio;
854 if (zio->io_child_type > ZIO_CHILD_GANG && BP_IS_GANG(bp))
855 pipeline |= ZIO_GANG_STAGES;
861 zio->io_private = private;
863 zio->io_priority = priority;
865 zio->io_offset = offset;
866 zio->io_orig_abd = zio->io_abd = data;
867 zio->io_orig_size = zio->io_size = psize;
868 zio->io_lsize = lsize;
869 zio->io_orig_flags = zio->io_flags = flags;
870 zio->io_orig_stage = zio->io_stage = stage;
871 zio->io_orig_pipeline = zio->io_pipeline = pipeline;
872 zio->io_pipeline_trace = ZIO_STAGE_OPEN;
874 zio->io_state[ZIO_WAIT_READY] = (stage >= ZIO_STAGE_READY);
875 zio->io_state[ZIO_WAIT_DONE] = (stage >= ZIO_STAGE_DONE);
878 zio->io_bookmark = *zb;
881 zio->io_metaslab_class = pio->io_metaslab_class;
882 if (zio->io_logical == NULL)
883 zio->io_logical = pio->io_logical;
884 if (zio->io_child_type == ZIO_CHILD_GANG)
885 zio->io_gang_leader = pio->io_gang_leader;
886 zio_add_child(pio, zio);
889 taskq_init_ent(&zio->io_tqent);
895 zio_destroy(zio_t *zio)
897 metaslab_trace_fini(&zio->io_alloc_list);
898 list_destroy(&zio->io_parent_list);
899 list_destroy(&zio->io_child_list);
900 mutex_destroy(&zio->io_lock);
901 cv_destroy(&zio->io_cv);
902 kmem_cache_free(zio_cache, zio);
906 zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, zio_done_func_t *done,
907 void *private, enum zio_flag flags)
911 zio = zio_create(pio, spa, 0, NULL, NULL, 0, 0, done, private,
912 ZIO_TYPE_NULL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL,
913 ZIO_STAGE_OPEN, ZIO_INTERLOCK_PIPELINE);
919 zio_root(spa_t *spa, zio_done_func_t *done, void *private, enum zio_flag flags)
921 return (zio_null(NULL, spa, NULL, done, private, flags));
925 zfs_blkptr_verify_log(spa_t *spa, const blkptr_t *bp,
926 enum blk_verify_flag blk_verify, const char *fmt, ...)
932 (void) vsnprintf(buf, sizeof (buf), fmt, adx);
935 switch (blk_verify) {
936 case BLK_VERIFY_HALT:
937 dprintf_bp(bp, "blkptr at %p dprintf_bp():", bp);
938 zfs_panic_recover("%s: %s", spa_name(spa), buf);
941 zfs_dbgmsg("%s: %s", spa_name(spa), buf);
943 case BLK_VERIFY_ONLY:
951 * Verify the block pointer fields contain reasonable values. This means
952 * it only contains known object types, checksum/compression identifiers,
953 * block sizes within the maximum allowed limits, valid DVAs, etc.
955 * If everything checks out B_TRUE is returned. The zfs_blkptr_verify
956 * argument controls the behavior when an invalid field is detected.
958 * Modes for zfs_blkptr_verify:
959 * 1) BLK_VERIFY_ONLY (evaluate the block)
960 * 2) BLK_VERIFY_LOG (evaluate the block and log problems)
961 * 3) BLK_VERIFY_HALT (call zfs_panic_recover on error)
964 zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp, boolean_t config_held,
965 enum blk_verify_flag blk_verify)
969 if (!DMU_OT_IS_VALID(BP_GET_TYPE(bp))) {
970 errors += zfs_blkptr_verify_log(spa, bp, blk_verify,
971 "blkptr at %p has invalid TYPE %llu",
972 bp, (longlong_t)BP_GET_TYPE(bp));
974 if (BP_GET_CHECKSUM(bp) >= ZIO_CHECKSUM_FUNCTIONS ||
975 BP_GET_CHECKSUM(bp) <= ZIO_CHECKSUM_ON) {
976 errors += zfs_blkptr_verify_log(spa, bp, blk_verify,
977 "blkptr at %p has invalid CHECKSUM %llu",
978 bp, (longlong_t)BP_GET_CHECKSUM(bp));
980 if (BP_GET_COMPRESS(bp) >= ZIO_COMPRESS_FUNCTIONS ||
981 BP_GET_COMPRESS(bp) <= ZIO_COMPRESS_ON) {
982 errors += zfs_blkptr_verify_log(spa, bp, blk_verify,
983 "blkptr at %p has invalid COMPRESS %llu",
984 bp, (longlong_t)BP_GET_COMPRESS(bp));
986 if (BP_GET_LSIZE(bp) > SPA_MAXBLOCKSIZE) {
987 errors += zfs_blkptr_verify_log(spa, bp, blk_verify,
988 "blkptr at %p has invalid LSIZE %llu",
989 bp, (longlong_t)BP_GET_LSIZE(bp));
991 if (BP_GET_PSIZE(bp) > SPA_MAXBLOCKSIZE) {
992 errors += zfs_blkptr_verify_log(spa, bp, blk_verify,
993 "blkptr at %p has invalid PSIZE %llu",
994 bp, (longlong_t)BP_GET_PSIZE(bp));
997 if (BP_IS_EMBEDDED(bp)) {
998 if (BPE_GET_ETYPE(bp) >= NUM_BP_EMBEDDED_TYPES) {
999 errors += zfs_blkptr_verify_log(spa, bp, blk_verify,
1000 "blkptr at %p has invalid ETYPE %llu",
1001 bp, (longlong_t)BPE_GET_ETYPE(bp));
1006 * Do not verify individual DVAs if the config is not trusted. This
1007 * will be done once the zio is executed in vdev_mirror_map_alloc.
1009 if (!spa->spa_trust_config)
1010 return (errors == 0);
1013 spa_config_enter(spa, SCL_VDEV, bp, RW_READER);
1015 ASSERT(spa_config_held(spa, SCL_VDEV, RW_WRITER));
1017 * Pool-specific checks.
1019 * Note: it would be nice to verify that the blk_birth and
1020 * BP_PHYSICAL_BIRTH() are not too large. However, spa_freeze()
1021 * allows the birth time of log blocks (and dmu_sync()-ed blocks
1022 * that are in the log) to be arbitrarily large.
1024 for (int i = 0; i < BP_GET_NDVAS(bp); i++) {
1025 const dva_t *dva = &bp->blk_dva[i];
1026 uint64_t vdevid = DVA_GET_VDEV(dva);
1028 if (vdevid >= spa->spa_root_vdev->vdev_children) {
1029 errors += zfs_blkptr_verify_log(spa, bp, blk_verify,
1030 "blkptr at %p DVA %u has invalid VDEV %llu",
1031 bp, i, (longlong_t)vdevid);
1034 vdev_t *vd = spa->spa_root_vdev->vdev_child[vdevid];
1036 errors += zfs_blkptr_verify_log(spa, bp, blk_verify,
1037 "blkptr at %p DVA %u has invalid VDEV %llu",
1038 bp, i, (longlong_t)vdevid);
1041 if (vd->vdev_ops == &vdev_hole_ops) {
1042 errors += zfs_blkptr_verify_log(spa, bp, blk_verify,
1043 "blkptr at %p DVA %u has hole VDEV %llu",
1044 bp, i, (longlong_t)vdevid);
1047 if (vd->vdev_ops == &vdev_missing_ops) {
1049 * "missing" vdevs are valid during import, but we
1050 * don't have their detailed info (e.g. asize), so
1051 * we can't perform any more checks on them.
1055 uint64_t offset = DVA_GET_OFFSET(dva);
1056 uint64_t asize = DVA_GET_ASIZE(dva);
1057 if (DVA_GET_GANG(dva))
1058 asize = vdev_gang_header_asize(vd);
1059 if (offset + asize > vd->vdev_asize) {
1060 errors += zfs_blkptr_verify_log(spa, bp, blk_verify,
1061 "blkptr at %p DVA %u has invalid OFFSET %llu",
1062 bp, i, (longlong_t)offset);
1066 dprintf_bp(bp, "blkptr at %p dprintf_bp():", bp);
1068 spa_config_exit(spa, SCL_VDEV, bp);
1070 return (errors == 0);
1074 zfs_dva_valid(spa_t *spa, const dva_t *dva, const blkptr_t *bp)
1077 uint64_t vdevid = DVA_GET_VDEV(dva);
1079 if (vdevid >= spa->spa_root_vdev->vdev_children)
1082 vdev_t *vd = spa->spa_root_vdev->vdev_child[vdevid];
1086 if (vd->vdev_ops == &vdev_hole_ops)
1089 if (vd->vdev_ops == &vdev_missing_ops) {
1093 uint64_t offset = DVA_GET_OFFSET(dva);
1094 uint64_t asize = DVA_GET_ASIZE(dva);
1096 if (DVA_GET_GANG(dva))
1097 asize = vdev_gang_header_asize(vd);
1098 if (offset + asize > vd->vdev_asize)
1105 zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
1106 abd_t *data, uint64_t size, zio_done_func_t *done, void *private,
1107 zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb)
1111 zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp,
1112 data, size, size, done, private,
1113 ZIO_TYPE_READ, priority, flags, NULL, 0, zb,
1114 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ?
1115 ZIO_DDT_CHILD_READ_PIPELINE : ZIO_READ_PIPELINE);
1121 zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
1122 abd_t *data, uint64_t lsize, uint64_t psize, const zio_prop_t *zp,
1123 zio_done_func_t *ready, zio_done_func_t *children_ready,
1124 zio_done_func_t *physdone, zio_done_func_t *done,
1125 void *private, zio_priority_t priority, enum zio_flag flags,
1126 const zbookmark_phys_t *zb)
1130 ASSERT(zp->zp_checksum >= ZIO_CHECKSUM_OFF &&
1131 zp->zp_checksum < ZIO_CHECKSUM_FUNCTIONS &&
1132 zp->zp_compress >= ZIO_COMPRESS_OFF &&
1133 zp->zp_compress < ZIO_COMPRESS_FUNCTIONS &&
1134 DMU_OT_IS_VALID(zp->zp_type) &&
1135 zp->zp_level < 32 &&
1136 zp->zp_copies > 0 &&
1137 zp->zp_copies <= spa_max_replication(spa));
1139 zio = zio_create(pio, spa, txg, bp, data, lsize, psize, done, private,
1140 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb,
1141 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ?
1142 ZIO_DDT_CHILD_WRITE_PIPELINE : ZIO_WRITE_PIPELINE);
1144 zio->io_ready = ready;
1145 zio->io_children_ready = children_ready;
1146 zio->io_physdone = physdone;
1150 * Data can be NULL if we are going to call zio_write_override() to
1151 * provide the already-allocated BP. But we may need the data to
1152 * verify a dedup hit (if requested). In this case, don't try to
1153 * dedup (just take the already-allocated BP verbatim). Encrypted
1154 * dedup blocks need data as well so we also disable dedup in this
1158 (zio->io_prop.zp_dedup_verify || zio->io_prop.zp_encrypt)) {
1159 zio->io_prop.zp_dedup = zio->io_prop.zp_dedup_verify = B_FALSE;
1166 zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, abd_t *data,
1167 uint64_t size, zio_done_func_t *done, void *private,
1168 zio_priority_t priority, enum zio_flag flags, zbookmark_phys_t *zb)
1172 zio = zio_create(pio, spa, txg, bp, data, size, size, done, private,
1173 ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_IO_REWRITE, NULL, 0, zb,
1174 ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE);
1180 zio_write_override(zio_t *zio, blkptr_t *bp, int copies, boolean_t nopwrite)
1182 ASSERT(zio->io_type == ZIO_TYPE_WRITE);
1183 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1184 ASSERT(zio->io_stage == ZIO_STAGE_OPEN);
1185 ASSERT(zio->io_txg == spa_syncing_txg(zio->io_spa));
1188 * We must reset the io_prop to match the values that existed
1189 * when the bp was first written by dmu_sync() keeping in mind
1190 * that nopwrite and dedup are mutually exclusive.
1192 zio->io_prop.zp_dedup = nopwrite ? B_FALSE : zio->io_prop.zp_dedup;
1193 zio->io_prop.zp_nopwrite = nopwrite;
1194 zio->io_prop.zp_copies = copies;
1195 zio->io_bp_override = bp;
1199 zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp)
1202 (void) zfs_blkptr_verify(spa, bp, B_FALSE, BLK_VERIFY_HALT);
1205 * The check for EMBEDDED is a performance optimization. We
1206 * process the free here (by ignoring it) rather than
1207 * putting it on the list and then processing it in zio_free_sync().
1209 if (BP_IS_EMBEDDED(bp))
1211 metaslab_check_free(spa, bp);
1214 * Frees that are for the currently-syncing txg, are not going to be
1215 * deferred, and which will not need to do a read (i.e. not GANG or
1216 * DEDUP), can be processed immediately. Otherwise, put them on the
1217 * in-memory list for later processing.
1219 * Note that we only defer frees after zfs_sync_pass_deferred_free
1220 * when the log space map feature is disabled. [see relevant comment
1221 * in spa_sync_iterate_to_convergence()]
1223 if (BP_IS_GANG(bp) ||
1225 txg != spa->spa_syncing_txg ||
1226 (spa_sync_pass(spa) >= zfs_sync_pass_deferred_free &&
1227 !spa_feature_is_active(spa, SPA_FEATURE_LOG_SPACEMAP))) {
1228 bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp);
1230 VERIFY3P(zio_free_sync(NULL, spa, txg, bp, 0), ==, NULL);
1235 * To improve performance, this function may return NULL if we were able
1236 * to do the free immediately. This avoids the cost of creating a zio
1237 * (and linking it to the parent, etc).
1240 zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp,
1241 enum zio_flag flags)
1243 ASSERT(!BP_IS_HOLE(bp));
1244 ASSERT(spa_syncing_txg(spa) == txg);
1246 if (BP_IS_EMBEDDED(bp))
1249 metaslab_check_free(spa, bp);
1251 dsl_scan_freed(spa, bp);
1253 if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp)) {
1255 * GANG and DEDUP blocks can induce a read (for the gang block
1256 * header, or the DDT), so issue them asynchronously so that
1257 * this thread is not tied up.
1259 enum zio_stage stage =
1260 ZIO_FREE_PIPELINE | ZIO_STAGE_ISSUE_ASYNC;
1262 return (zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp),
1263 BP_GET_PSIZE(bp), NULL, NULL,
1264 ZIO_TYPE_FREE, ZIO_PRIORITY_NOW,
1265 flags, NULL, 0, NULL, ZIO_STAGE_OPEN, stage));
1267 metaslab_free(spa, bp, txg, B_FALSE);
1273 zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp,
1274 zio_done_func_t *done, void *private, enum zio_flag flags)
1278 (void) zfs_blkptr_verify(spa, bp, flags & ZIO_FLAG_CONFIG_WRITER,
1281 if (BP_IS_EMBEDDED(bp))
1282 return (zio_null(pio, spa, NULL, NULL, NULL, 0));
1285 * A claim is an allocation of a specific block. Claims are needed
1286 * to support immediate writes in the intent log. The issue is that
1287 * immediate writes contain committed data, but in a txg that was
1288 * *not* committed. Upon opening the pool after an unclean shutdown,
1289 * the intent log claims all blocks that contain immediate write data
1290 * so that the SPA knows they're in use.
1292 * All claims *must* be resolved in the first txg -- before the SPA
1293 * starts allocating blocks -- so that nothing is allocated twice.
1294 * If txg == 0 we just verify that the block is claimable.
1296 ASSERT3U(spa->spa_uberblock.ub_rootbp.blk_birth, <,
1297 spa_min_claim_txg(spa));
1298 ASSERT(txg == spa_min_claim_txg(spa) || txg == 0);
1299 ASSERT(!BP_GET_DEDUP(bp) || !spa_writeable(spa)); /* zdb(8) */
1301 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp),
1302 BP_GET_PSIZE(bp), done, private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW,
1303 flags, NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE);
1304 ASSERT0(zio->io_queued_timestamp);
1310 zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
1311 zio_done_func_t *done, void *private, enum zio_flag flags)
1316 if (vd->vdev_children == 0) {
1317 zio = zio_create(pio, spa, 0, NULL, NULL, 0, 0, done, private,
1318 ZIO_TYPE_IOCTL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL,
1319 ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE);
1323 zio = zio_null(pio, spa, NULL, NULL, NULL, flags);
1325 for (c = 0; c < vd->vdev_children; c++)
1326 zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd,
1327 done, private, flags));
1334 zio_trim(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size,
1335 zio_done_func_t *done, void *private, zio_priority_t priority,
1336 enum zio_flag flags, enum trim_flag trim_flags)
1340 ASSERT0(vd->vdev_children);
1341 ASSERT0(P2PHASE(offset, 1ULL << vd->vdev_ashift));
1342 ASSERT0(P2PHASE(size, 1ULL << vd->vdev_ashift));
1343 ASSERT3U(size, !=, 0);
1345 zio = zio_create(pio, vd->vdev_spa, 0, NULL, NULL, size, size, done,
1346 private, ZIO_TYPE_TRIM, priority, flags | ZIO_FLAG_PHYSICAL,
1347 vd, offset, NULL, ZIO_STAGE_OPEN, ZIO_TRIM_PIPELINE);
1348 zio->io_trim_flags = trim_flags;
1354 zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size,
1355 abd_t *data, int checksum, zio_done_func_t *done, void *private,
1356 zio_priority_t priority, enum zio_flag flags, boolean_t labels)
1360 ASSERT(vd->vdev_children == 0);
1361 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE ||
1362 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE);
1363 ASSERT3U(offset + size, <=, vd->vdev_psize);
1365 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, size, done,
1366 private, ZIO_TYPE_READ, priority, flags | ZIO_FLAG_PHYSICAL, vd,
1367 offset, NULL, ZIO_STAGE_OPEN, ZIO_READ_PHYS_PIPELINE);
1369 zio->io_prop.zp_checksum = checksum;
1375 zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size,
1376 abd_t *data, int checksum, zio_done_func_t *done, void *private,
1377 zio_priority_t priority, enum zio_flag flags, boolean_t labels)
1381 ASSERT(vd->vdev_children == 0);
1382 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE ||
1383 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE);
1384 ASSERT3U(offset + size, <=, vd->vdev_psize);
1386 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, size, done,
1387 private, ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_PHYSICAL, vd,
1388 offset, NULL, ZIO_STAGE_OPEN, ZIO_WRITE_PHYS_PIPELINE);
1390 zio->io_prop.zp_checksum = checksum;
1392 if (zio_checksum_table[checksum].ci_flags & ZCHECKSUM_FLAG_EMBEDDED) {
1394 * zec checksums are necessarily destructive -- they modify
1395 * the end of the write buffer to hold the verifier/checksum.
1396 * Therefore, we must make a local copy in case the data is
1397 * being written to multiple places in parallel.
1399 abd_t *wbuf = abd_alloc_sametype(data, size);
1400 abd_copy(wbuf, data, size);
1402 zio_push_transform(zio, wbuf, size, size, NULL);
1409 * Create a child I/O to do some work for us.
1412 zio_vdev_child_io(zio_t *pio, blkptr_t *bp, vdev_t *vd, uint64_t offset,
1413 abd_t *data, uint64_t size, int type, zio_priority_t priority,
1414 enum zio_flag flags, zio_done_func_t *done, void *private)
1416 enum zio_stage pipeline = ZIO_VDEV_CHILD_PIPELINE;
1420 * vdev child I/Os do not propagate their error to the parent.
1421 * Therefore, for correct operation the caller *must* check for
1422 * and handle the error in the child i/o's done callback.
1423 * The only exceptions are i/os that we don't care about
1424 * (OPTIONAL or REPAIR).
1426 ASSERT((flags & ZIO_FLAG_OPTIONAL) || (flags & ZIO_FLAG_IO_REPAIR) ||
1429 if (type == ZIO_TYPE_READ && bp != NULL) {
1431 * If we have the bp, then the child should perform the
1432 * checksum and the parent need not. This pushes error
1433 * detection as close to the leaves as possible and
1434 * eliminates redundant checksums in the interior nodes.
1436 pipeline |= ZIO_STAGE_CHECKSUM_VERIFY;
1437 pio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY;
1440 if (vd->vdev_ops->vdev_op_leaf) {
1441 ASSERT0(vd->vdev_children);
1442 offset += VDEV_LABEL_START_SIZE;
1445 flags |= ZIO_VDEV_CHILD_FLAGS(pio);
1448 * If we've decided to do a repair, the write is not speculative --
1449 * even if the original read was.
1451 if (flags & ZIO_FLAG_IO_REPAIR)
1452 flags &= ~ZIO_FLAG_SPECULATIVE;
1455 * If we're creating a child I/O that is not associated with a
1456 * top-level vdev, then the child zio is not an allocating I/O.
1457 * If this is a retried I/O then we ignore it since we will
1458 * have already processed the original allocating I/O.
1460 if (flags & ZIO_FLAG_IO_ALLOCATING &&
1461 (vd != vd->vdev_top || (flags & ZIO_FLAG_IO_RETRY))) {
1462 ASSERT(pio->io_metaslab_class != NULL);
1463 ASSERT(pio->io_metaslab_class->mc_alloc_throttle_enabled);
1464 ASSERT(type == ZIO_TYPE_WRITE);
1465 ASSERT(priority == ZIO_PRIORITY_ASYNC_WRITE);
1466 ASSERT(!(flags & ZIO_FLAG_IO_REPAIR));
1467 ASSERT(!(pio->io_flags & ZIO_FLAG_IO_REWRITE) ||
1468 pio->io_child_type == ZIO_CHILD_GANG);
1470 flags &= ~ZIO_FLAG_IO_ALLOCATING;
1474 zio = zio_create(pio, pio->io_spa, pio->io_txg, bp, data, size, size,
1475 done, private, type, priority, flags, vd, offset, &pio->io_bookmark,
1476 ZIO_STAGE_VDEV_IO_START >> 1, pipeline);
1477 ASSERT3U(zio->io_child_type, ==, ZIO_CHILD_VDEV);
1479 zio->io_physdone = pio->io_physdone;
1480 if (vd->vdev_ops->vdev_op_leaf && zio->io_logical != NULL)
1481 zio->io_logical->io_phys_children++;
1487 zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, abd_t *data, uint64_t size,
1488 zio_type_t type, zio_priority_t priority, enum zio_flag flags,
1489 zio_done_func_t *done, void *private)
1493 ASSERT(vd->vdev_ops->vdev_op_leaf);
1495 zio = zio_create(NULL, vd->vdev_spa, 0, NULL,
1496 data, size, size, done, private, type, priority,
1497 flags | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY | ZIO_FLAG_DELEGATED,
1499 ZIO_STAGE_VDEV_IO_START >> 1, ZIO_VDEV_CHILD_PIPELINE);
1505 zio_flush(zio_t *zio, vdev_t *vd)
1507 zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE,
1509 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY));
1513 zio_shrink(zio_t *zio, uint64_t size)
1515 ASSERT3P(zio->io_executor, ==, NULL);
1516 ASSERT3U(zio->io_orig_size, ==, zio->io_size);
1517 ASSERT3U(size, <=, zio->io_size);
1520 * We don't shrink for raidz because of problems with the
1521 * reconstruction when reading back less than the block size.
1522 * Note, BP_IS_RAIDZ() assumes no compression.
1524 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF);
1525 if (!BP_IS_RAIDZ(zio->io_bp)) {
1526 /* we are not doing a raw write */
1527 ASSERT3U(zio->io_size, ==, zio->io_lsize);
1528 zio->io_orig_size = zio->io_size = zio->io_lsize = size;
1533 * ==========================================================================
1534 * Prepare to read and write logical blocks
1535 * ==========================================================================
1539 zio_read_bp_init(zio_t *zio)
1541 blkptr_t *bp = zio->io_bp;
1543 BP_IS_EMBEDDED(bp) ? BPE_GET_PSIZE(bp) : BP_GET_PSIZE(bp);
1545 ASSERT3P(zio->io_bp, ==, &zio->io_bp_copy);
1547 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF &&
1548 zio->io_child_type == ZIO_CHILD_LOGICAL &&
1549 !(zio->io_flags & ZIO_FLAG_RAW_COMPRESS)) {
1550 zio_push_transform(zio, abd_alloc_sametype(zio->io_abd, psize),
1551 psize, psize, zio_decompress);
1554 if (((BP_IS_PROTECTED(bp) && !(zio->io_flags & ZIO_FLAG_RAW_ENCRYPT)) ||
1555 BP_HAS_INDIRECT_MAC_CKSUM(bp)) &&
1556 zio->io_child_type == ZIO_CHILD_LOGICAL) {
1557 zio_push_transform(zio, abd_alloc_sametype(zio->io_abd, psize),
1558 psize, psize, zio_decrypt);
1561 if (BP_IS_EMBEDDED(bp) && BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA) {
1562 int psize = BPE_GET_PSIZE(bp);
1563 void *data = abd_borrow_buf(zio->io_abd, psize);
1565 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
1566 decode_embedded_bp_compressed(bp, data);
1567 abd_return_buf_copy(zio->io_abd, data, psize);
1569 ASSERT(!BP_IS_EMBEDDED(bp));
1570 ASSERT3P(zio->io_bp, ==, &zio->io_bp_copy);
1573 if (!DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) && BP_GET_LEVEL(bp) == 0)
1574 zio->io_flags |= ZIO_FLAG_DONT_CACHE;
1576 if (BP_GET_TYPE(bp) == DMU_OT_DDT_ZAP)
1577 zio->io_flags |= ZIO_FLAG_DONT_CACHE;
1579 if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL)
1580 zio->io_pipeline = ZIO_DDT_READ_PIPELINE;
1586 zio_write_bp_init(zio_t *zio)
1588 if (!IO_IS_ALLOCATING(zio))
1591 ASSERT(zio->io_child_type != ZIO_CHILD_DDT);
1593 if (zio->io_bp_override) {
1594 blkptr_t *bp = zio->io_bp;
1595 zio_prop_t *zp = &zio->io_prop;
1597 ASSERT(bp->blk_birth != zio->io_txg);
1598 ASSERT(BP_GET_DEDUP(zio->io_bp_override) == 0);
1600 *bp = *zio->io_bp_override;
1601 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
1603 if (BP_IS_EMBEDDED(bp))
1607 * If we've been overridden and nopwrite is set then
1608 * set the flag accordingly to indicate that a nopwrite
1609 * has already occurred.
1611 if (!BP_IS_HOLE(bp) && zp->zp_nopwrite) {
1612 ASSERT(!zp->zp_dedup);
1613 ASSERT3U(BP_GET_CHECKSUM(bp), ==, zp->zp_checksum);
1614 zio->io_flags |= ZIO_FLAG_NOPWRITE;
1618 ASSERT(!zp->zp_nopwrite);
1620 if (BP_IS_HOLE(bp) || !zp->zp_dedup)
1623 ASSERT((zio_checksum_table[zp->zp_checksum].ci_flags &
1624 ZCHECKSUM_FLAG_DEDUP) || zp->zp_dedup_verify);
1626 if (BP_GET_CHECKSUM(bp) == zp->zp_checksum &&
1628 BP_SET_DEDUP(bp, 1);
1629 zio->io_pipeline |= ZIO_STAGE_DDT_WRITE;
1634 * We were unable to handle this as an override bp, treat
1635 * it as a regular write I/O.
1637 zio->io_bp_override = NULL;
1638 *bp = zio->io_bp_orig;
1639 zio->io_pipeline = zio->io_orig_pipeline;
1646 zio_write_compress(zio_t *zio)
1648 spa_t *spa = zio->io_spa;
1649 zio_prop_t *zp = &zio->io_prop;
1650 enum zio_compress compress = zp->zp_compress;
1651 blkptr_t *bp = zio->io_bp;
1652 uint64_t lsize = zio->io_lsize;
1653 uint64_t psize = zio->io_size;
1657 * If our children haven't all reached the ready stage,
1658 * wait for them and then repeat this pipeline stage.
1660 if (zio_wait_for_children(zio, ZIO_CHILD_LOGICAL_BIT |
1661 ZIO_CHILD_GANG_BIT, ZIO_WAIT_READY)) {
1665 if (!IO_IS_ALLOCATING(zio))
1668 if (zio->io_children_ready != NULL) {
1670 * Now that all our children are ready, run the callback
1671 * associated with this zio in case it wants to modify the
1672 * data to be written.
1674 ASSERT3U(zp->zp_level, >, 0);
1675 zio->io_children_ready(zio);
1678 ASSERT(zio->io_child_type != ZIO_CHILD_DDT);
1679 ASSERT(zio->io_bp_override == NULL);
1681 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg) {
1683 * We're rewriting an existing block, which means we're
1684 * working on behalf of spa_sync(). For spa_sync() to
1685 * converge, it must eventually be the case that we don't
1686 * have to allocate new blocks. But compression changes
1687 * the blocksize, which forces a reallocate, and makes
1688 * convergence take longer. Therefore, after the first
1689 * few passes, stop compressing to ensure convergence.
1691 pass = spa_sync_pass(spa);
1693 ASSERT(zio->io_txg == spa_syncing_txg(spa));
1694 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1695 ASSERT(!BP_GET_DEDUP(bp));
1697 if (pass >= zfs_sync_pass_dont_compress)
1698 compress = ZIO_COMPRESS_OFF;
1700 /* Make sure someone doesn't change their mind on overwrites */
1701 ASSERT(BP_IS_EMBEDDED(bp) || MIN(zp->zp_copies + BP_IS_GANG(bp),
1702 spa_max_replication(spa)) == BP_GET_NDVAS(bp));
1705 /* If it's a compressed write that is not raw, compress the buffer. */
1706 if (compress != ZIO_COMPRESS_OFF &&
1707 !(zio->io_flags & ZIO_FLAG_RAW_COMPRESS)) {
1708 void *cbuf = zio_buf_alloc(lsize);
1709 psize = zio_compress_data(compress, zio->io_abd, cbuf, lsize,
1711 if (psize == 0 || psize >= lsize) {
1712 compress = ZIO_COMPRESS_OFF;
1713 zio_buf_free(cbuf, lsize);
1714 } else if (!zp->zp_dedup && !zp->zp_encrypt &&
1715 psize <= BPE_PAYLOAD_SIZE &&
1716 zp->zp_level == 0 && !DMU_OT_HAS_FILL(zp->zp_type) &&
1717 spa_feature_is_enabled(spa, SPA_FEATURE_EMBEDDED_DATA)) {
1718 encode_embedded_bp_compressed(bp,
1719 cbuf, compress, lsize, psize);
1720 BPE_SET_ETYPE(bp, BP_EMBEDDED_TYPE_DATA);
1721 BP_SET_TYPE(bp, zio->io_prop.zp_type);
1722 BP_SET_LEVEL(bp, zio->io_prop.zp_level);
1723 zio_buf_free(cbuf, lsize);
1724 bp->blk_birth = zio->io_txg;
1725 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
1726 ASSERT(spa_feature_is_active(spa,
1727 SPA_FEATURE_EMBEDDED_DATA));
1731 * Round compressed size up to the minimum allocation
1732 * size of the smallest-ashift device, and zero the
1733 * tail. This ensures that the compressed size of the
1734 * BP (and thus compressratio property) are correct,
1735 * in that we charge for the padding used to fill out
1738 ASSERT3U(spa->spa_min_alloc, >=, SPA_MINBLOCKSHIFT);
1739 size_t rounded = (size_t)roundup(psize,
1740 spa->spa_min_alloc);
1741 if (rounded >= lsize) {
1742 compress = ZIO_COMPRESS_OFF;
1743 zio_buf_free(cbuf, lsize);
1746 abd_t *cdata = abd_get_from_buf(cbuf, lsize);
1747 abd_take_ownership_of_buf(cdata, B_TRUE);
1748 abd_zero_off(cdata, psize, rounded - psize);
1750 zio_push_transform(zio, cdata,
1751 psize, lsize, NULL);
1756 * We were unable to handle this as an override bp, treat
1757 * it as a regular write I/O.
1759 zio->io_bp_override = NULL;
1760 *bp = zio->io_bp_orig;
1761 zio->io_pipeline = zio->io_orig_pipeline;
1763 } else if ((zio->io_flags & ZIO_FLAG_RAW_ENCRYPT) != 0 &&
1764 zp->zp_type == DMU_OT_DNODE) {
1766 * The DMU actually relies on the zio layer's compression
1767 * to free metadnode blocks that have had all contained
1768 * dnodes freed. As a result, even when doing a raw
1769 * receive, we must check whether the block can be compressed
1772 psize = zio_compress_data(ZIO_COMPRESS_EMPTY,
1773 zio->io_abd, NULL, lsize, zp->zp_complevel);
1774 if (psize == 0 || psize >= lsize)
1775 compress = ZIO_COMPRESS_OFF;
1776 } else if (zio->io_flags & ZIO_FLAG_RAW_COMPRESS) {
1777 size_t rounded = MIN((size_t)roundup(psize,
1778 spa->spa_min_alloc), lsize);
1780 if (rounded != psize) {
1781 abd_t *cdata = abd_alloc_linear(rounded, B_TRUE);
1782 abd_zero_off(cdata, psize, rounded - psize);
1783 abd_copy_off(cdata, zio->io_abd, 0, 0, psize);
1785 zio_push_transform(zio, cdata,
1786 psize, rounded, NULL);
1789 ASSERT3U(psize, !=, 0);
1793 * The final pass of spa_sync() must be all rewrites, but the first
1794 * few passes offer a trade-off: allocating blocks defers convergence,
1795 * but newly allocated blocks are sequential, so they can be written
1796 * to disk faster. Therefore, we allow the first few passes of
1797 * spa_sync() to allocate new blocks, but force rewrites after that.
1798 * There should only be a handful of blocks after pass 1 in any case.
1800 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg &&
1801 BP_GET_PSIZE(bp) == psize &&
1802 pass >= zfs_sync_pass_rewrite) {
1803 VERIFY3U(psize, !=, 0);
1804 enum zio_stage gang_stages = zio->io_pipeline & ZIO_GANG_STAGES;
1806 zio->io_pipeline = ZIO_REWRITE_PIPELINE | gang_stages;
1807 zio->io_flags |= ZIO_FLAG_IO_REWRITE;
1810 zio->io_pipeline = ZIO_WRITE_PIPELINE;
1814 if (zio->io_bp_orig.blk_birth != 0 &&
1815 spa_feature_is_active(spa, SPA_FEATURE_HOLE_BIRTH)) {
1816 BP_SET_LSIZE(bp, lsize);
1817 BP_SET_TYPE(bp, zp->zp_type);
1818 BP_SET_LEVEL(bp, zp->zp_level);
1819 BP_SET_BIRTH(bp, zio->io_txg, 0);
1821 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
1823 ASSERT(zp->zp_checksum != ZIO_CHECKSUM_GANG_HEADER);
1824 BP_SET_LSIZE(bp, lsize);
1825 BP_SET_TYPE(bp, zp->zp_type);
1826 BP_SET_LEVEL(bp, zp->zp_level);
1827 BP_SET_PSIZE(bp, psize);
1828 BP_SET_COMPRESS(bp, compress);
1829 BP_SET_CHECKSUM(bp, zp->zp_checksum);
1830 BP_SET_DEDUP(bp, zp->zp_dedup);
1831 BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER);
1833 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1834 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE));
1835 ASSERT(!zp->zp_encrypt ||
1836 DMU_OT_IS_ENCRYPTED(zp->zp_type));
1837 zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE;
1839 if (zp->zp_nopwrite) {
1840 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1841 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE));
1842 zio->io_pipeline |= ZIO_STAGE_NOP_WRITE;
1849 zio_free_bp_init(zio_t *zio)
1851 blkptr_t *bp = zio->io_bp;
1853 if (zio->io_child_type == ZIO_CHILD_LOGICAL) {
1854 if (BP_GET_DEDUP(bp))
1855 zio->io_pipeline = ZIO_DDT_FREE_PIPELINE;
1858 ASSERT3P(zio->io_bp, ==, &zio->io_bp_copy);
1864 * ==========================================================================
1865 * Execute the I/O pipeline
1866 * ==========================================================================
1870 zio_taskq_dispatch(zio_t *zio, zio_taskq_type_t q, boolean_t cutinline)
1872 spa_t *spa = zio->io_spa;
1873 zio_type_t t = zio->io_type;
1874 int flags = (cutinline ? TQ_FRONT : 0);
1877 * If we're a config writer or a probe, the normal issue and
1878 * interrupt threads may all be blocked waiting for the config lock.
1879 * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL.
1881 if (zio->io_flags & (ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_PROBE))
1885 * A similar issue exists for the L2ARC write thread until L2ARC 2.0.
1887 if (t == ZIO_TYPE_WRITE && zio->io_vd && zio->io_vd->vdev_aux)
1891 * If this is a high priority I/O, then use the high priority taskq if
1894 if ((zio->io_priority == ZIO_PRIORITY_NOW ||
1895 zio->io_priority == ZIO_PRIORITY_SYNC_WRITE) &&
1896 spa->spa_zio_taskq[t][q + 1].stqs_count != 0)
1899 ASSERT3U(q, <, ZIO_TASKQ_TYPES);
1902 * NB: We are assuming that the zio can only be dispatched
1903 * to a single taskq at a time. It would be a grievous error
1904 * to dispatch the zio to another taskq at the same time.
1906 ASSERT(taskq_empty_ent(&zio->io_tqent));
1907 spa_taskq_dispatch_ent(spa, t, q, zio_execute, zio, flags,
1912 zio_taskq_member(zio_t *zio, zio_taskq_type_t q)
1914 spa_t *spa = zio->io_spa;
1916 taskq_t *tq = taskq_of_curthread();
1918 for (zio_type_t t = 0; t < ZIO_TYPES; t++) {
1919 spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
1921 for (i = 0; i < tqs->stqs_count; i++) {
1922 if (tqs->stqs_taskq[i] == tq)
1931 zio_issue_async(zio_t *zio)
1933 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE);
1939 zio_interrupt(void *zio)
1941 zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE);
1945 zio_delay_interrupt(zio_t *zio)
1948 * The timeout_generic() function isn't defined in userspace, so
1949 * rather than trying to implement the function, the zio delay
1950 * functionality has been disabled for userspace builds.
1955 * If io_target_timestamp is zero, then no delay has been registered
1956 * for this IO, thus jump to the end of this function and "skip" the
1957 * delay; issuing it directly to the zio layer.
1959 if (zio->io_target_timestamp != 0) {
1960 hrtime_t now = gethrtime();
1962 if (now >= zio->io_target_timestamp) {
1964 * This IO has already taken longer than the target
1965 * delay to complete, so we don't want to delay it
1966 * any longer; we "miss" the delay and issue it
1967 * directly to the zio layer. This is likely due to
1968 * the target latency being set to a value less than
1969 * the underlying hardware can satisfy (e.g. delay
1970 * set to 1ms, but the disks take 10ms to complete an
1974 DTRACE_PROBE2(zio__delay__miss, zio_t *, zio,
1980 hrtime_t diff = zio->io_target_timestamp - now;
1981 clock_t expire_at_tick = ddi_get_lbolt() +
1984 DTRACE_PROBE3(zio__delay__hit, zio_t *, zio,
1985 hrtime_t, now, hrtime_t, diff);
1987 if (NSEC_TO_TICK(diff) == 0) {
1988 /* Our delay is less than a jiffy - just spin */
1989 zfs_sleep_until(zio->io_target_timestamp);
1993 * Use taskq_dispatch_delay() in the place of
1994 * OpenZFS's timeout_generic().
1996 tid = taskq_dispatch_delay(system_taskq,
1997 zio_interrupt, zio, TQ_NOSLEEP,
1999 if (tid == TASKQID_INVALID) {
2001 * Couldn't allocate a task. Just
2002 * finish the zio without a delay.
2011 DTRACE_PROBE1(zio__delay__skip, zio_t *, zio);
2016 zio_deadman_impl(zio_t *pio, int ziodepth)
2018 zio_t *cio, *cio_next;
2019 zio_link_t *zl = NULL;
2020 vdev_t *vd = pio->io_vd;
2022 if (zio_deadman_log_all || (vd != NULL && vd->vdev_ops->vdev_op_leaf)) {
2023 vdev_queue_t *vq = vd ? &vd->vdev_queue : NULL;
2024 zbookmark_phys_t *zb = &pio->io_bookmark;
2025 uint64_t delta = gethrtime() - pio->io_timestamp;
2026 uint64_t failmode = spa_get_deadman_failmode(pio->io_spa);
2028 zfs_dbgmsg("slow zio[%d]: zio=%px timestamp=%llu "
2029 "delta=%llu queued=%llu io=%llu "
2031 "last=%llu type=%d "
2032 "priority=%d flags=0x%x stage=0x%x "
2033 "pipeline=0x%x pipeline-trace=0x%x "
2034 "objset=%llu object=%llu "
2035 "level=%llu blkid=%llu "
2036 "offset=%llu size=%llu "
2038 ziodepth, pio, pio->io_timestamp,
2039 (u_longlong_t)delta, pio->io_delta, pio->io_delay,
2040 vd ? vd->vdev_path : "NULL",
2041 vq ? vq->vq_io_complete_ts : 0, pio->io_type,
2042 pio->io_priority, pio->io_flags, pio->io_stage,
2043 pio->io_pipeline, pio->io_pipeline_trace,
2044 (u_longlong_t)zb->zb_objset, (u_longlong_t)zb->zb_object,
2045 (u_longlong_t)zb->zb_level, (u_longlong_t)zb->zb_blkid,
2046 (u_longlong_t)pio->io_offset, (u_longlong_t)pio->io_size,
2048 (void) zfs_ereport_post(FM_EREPORT_ZFS_DEADMAN,
2049 pio->io_spa, vd, zb, pio, 0);
2051 if (failmode == ZIO_FAILURE_MODE_CONTINUE &&
2052 taskq_empty_ent(&pio->io_tqent)) {
2057 mutex_enter(&pio->io_lock);
2058 for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) {
2059 cio_next = zio_walk_children(pio, &zl);
2060 zio_deadman_impl(cio, ziodepth + 1);
2062 mutex_exit(&pio->io_lock);
2066 * Log the critical information describing this zio and all of its children
2067 * using the zfs_dbgmsg() interface then post deadman event for the ZED.
2070 zio_deadman(zio_t *pio, char *tag)
2072 spa_t *spa = pio->io_spa;
2073 char *name = spa_name(spa);
2075 if (!zfs_deadman_enabled || spa_suspended(spa))
2078 zio_deadman_impl(pio, 0);
2080 switch (spa_get_deadman_failmode(spa)) {
2081 case ZIO_FAILURE_MODE_WAIT:
2082 zfs_dbgmsg("%s waiting for hung I/O to pool '%s'", tag, name);
2085 case ZIO_FAILURE_MODE_CONTINUE:
2086 zfs_dbgmsg("%s restarting hung I/O for pool '%s'", tag, name);
2089 case ZIO_FAILURE_MODE_PANIC:
2090 fm_panic("%s determined I/O to pool '%s' is hung.", tag, name);
2096 * Execute the I/O pipeline until one of the following occurs:
2097 * (1) the I/O completes; (2) the pipeline stalls waiting for
2098 * dependent child I/Os; (3) the I/O issues, so we're waiting
2099 * for an I/O completion interrupt; (4) the I/O is delegated by
2100 * vdev-level caching or aggregation; (5) the I/O is deferred
2101 * due to vdev-level queueing; (6) the I/O is handed off to
2102 * another thread. In all cases, the pipeline stops whenever
2103 * there's no CPU work; it never burns a thread in cv_wait_io().
2105 * There's no locking on io_stage because there's no legitimate way
2106 * for multiple threads to be attempting to process the same I/O.
2108 static zio_pipe_stage_t *zio_pipeline[];
2111 * zio_execute() is a wrapper around the static function
2112 * __zio_execute() so that we can force __zio_execute() to be
2113 * inlined. This reduces stack overhead which is important
2114 * because __zio_execute() is called recursively in several zio
2115 * code paths. zio_execute() itself cannot be inlined because
2116 * it is externally visible.
2119 zio_execute(void *zio)
2121 fstrans_cookie_t cookie;
2123 cookie = spl_fstrans_mark();
2125 spl_fstrans_unmark(cookie);
2129 * Used to determine if in the current context the stack is sized large
2130 * enough to allow zio_execute() to be called recursively. A minimum
2131 * stack size of 16K is required to avoid needing to re-dispatch the zio.
2134 zio_execute_stack_check(zio_t *zio)
2136 #if !defined(HAVE_LARGE_STACKS)
2137 dsl_pool_t *dp = spa_get_dsl(zio->io_spa);
2139 /* Executing in txg_sync_thread() context. */
2140 if (dp && curthread == dp->dp_tx.tx_sync_thread)
2143 /* Pool initialization outside of zio_taskq context. */
2144 if (dp && spa_is_initializing(dp->dp_spa) &&
2145 !zio_taskq_member(zio, ZIO_TASKQ_ISSUE) &&
2146 !zio_taskq_member(zio, ZIO_TASKQ_ISSUE_HIGH))
2150 #endif /* HAVE_LARGE_STACKS */
2155 __attribute__((always_inline))
2157 __zio_execute(zio_t *zio)
2159 ASSERT3U(zio->io_queued_timestamp, >, 0);
2161 while (zio->io_stage < ZIO_STAGE_DONE) {
2162 enum zio_stage pipeline = zio->io_pipeline;
2163 enum zio_stage stage = zio->io_stage;
2165 zio->io_executor = curthread;
2167 ASSERT(!MUTEX_HELD(&zio->io_lock));
2168 ASSERT(ISP2(stage));
2169 ASSERT(zio->io_stall == NULL);
2173 } while ((stage & pipeline) == 0);
2175 ASSERT(stage <= ZIO_STAGE_DONE);
2178 * If we are in interrupt context and this pipeline stage
2179 * will grab a config lock that is held across I/O,
2180 * or may wait for an I/O that needs an interrupt thread
2181 * to complete, issue async to avoid deadlock.
2183 * For VDEV_IO_START, we cut in line so that the io will
2184 * be sent to disk promptly.
2186 if ((stage & ZIO_BLOCKING_STAGES) && zio->io_vd == NULL &&
2187 zio_taskq_member(zio, ZIO_TASKQ_INTERRUPT)) {
2188 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ?
2189 zio_requeue_io_start_cut_in_line : B_FALSE;
2190 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut);
2195 * If the current context doesn't have large enough stacks
2196 * the zio must be issued asynchronously to prevent overflow.
2198 if (zio_execute_stack_check(zio)) {
2199 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ?
2200 zio_requeue_io_start_cut_in_line : B_FALSE;
2201 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut);
2205 zio->io_stage = stage;
2206 zio->io_pipeline_trace |= zio->io_stage;
2209 * The zio pipeline stage returns the next zio to execute
2210 * (typically the same as this one), or NULL if we should
2213 zio = zio_pipeline[highbit64(stage) - 1](zio);
2222 * ==========================================================================
2223 * Initiate I/O, either sync or async
2224 * ==========================================================================
2227 zio_wait(zio_t *zio)
2230 * Some routines, like zio_free_sync(), may return a NULL zio
2231 * to avoid the performance overhead of creating and then destroying
2232 * an unneeded zio. For the callers' simplicity, we accept a NULL
2233 * zio and ignore it.
2238 long timeout = MSEC_TO_TICK(zfs_deadman_ziotime_ms);
2241 ASSERT3S(zio->io_stage, ==, ZIO_STAGE_OPEN);
2242 ASSERT3P(zio->io_executor, ==, NULL);
2244 zio->io_waiter = curthread;
2245 ASSERT0(zio->io_queued_timestamp);
2246 zio->io_queued_timestamp = gethrtime();
2250 mutex_enter(&zio->io_lock);
2251 while (zio->io_executor != NULL) {
2252 error = cv_timedwait_io(&zio->io_cv, &zio->io_lock,
2253 ddi_get_lbolt() + timeout);
2255 if (zfs_deadman_enabled && error == -1 &&
2256 gethrtime() - zio->io_queued_timestamp >
2257 spa_deadman_ziotime(zio->io_spa)) {
2258 mutex_exit(&zio->io_lock);
2259 timeout = MSEC_TO_TICK(zfs_deadman_checktime_ms);
2260 zio_deadman(zio, FTAG);
2261 mutex_enter(&zio->io_lock);
2264 mutex_exit(&zio->io_lock);
2266 error = zio->io_error;
2273 zio_nowait(zio_t *zio)
2276 * See comment in zio_wait().
2281 ASSERT3P(zio->io_executor, ==, NULL);
2283 if (zio->io_child_type == ZIO_CHILD_LOGICAL &&
2284 zio_unique_parent(zio) == NULL) {
2288 * This is a logical async I/O with no parent to wait for it.
2289 * We add it to the spa_async_root_zio "Godfather" I/O which
2290 * will ensure they complete prior to unloading the pool.
2292 spa_t *spa = zio->io_spa;
2293 pio = spa->spa_async_zio_root[CPU_SEQID_UNSTABLE];
2295 zio_add_child(pio, zio);
2298 ASSERT0(zio->io_queued_timestamp);
2299 zio->io_queued_timestamp = gethrtime();
2304 * ==========================================================================
2305 * Reexecute, cancel, or suspend/resume failed I/O
2306 * ==========================================================================
2310 zio_reexecute(void *arg)
2313 zio_t *cio, *cio_next;
2315 ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL);
2316 ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN);
2317 ASSERT(pio->io_gang_leader == NULL);
2318 ASSERT(pio->io_gang_tree == NULL);
2320 pio->io_flags = pio->io_orig_flags;
2321 pio->io_stage = pio->io_orig_stage;
2322 pio->io_pipeline = pio->io_orig_pipeline;
2323 pio->io_reexecute = 0;
2324 pio->io_flags |= ZIO_FLAG_REEXECUTED;
2325 pio->io_pipeline_trace = 0;
2327 for (int w = 0; w < ZIO_WAIT_TYPES; w++)
2328 pio->io_state[w] = 0;
2329 for (int c = 0; c < ZIO_CHILD_TYPES; c++)
2330 pio->io_child_error[c] = 0;
2332 if (IO_IS_ALLOCATING(pio))
2333 BP_ZERO(pio->io_bp);
2336 * As we reexecute pio's children, new children could be created.
2337 * New children go to the head of pio's io_child_list, however,
2338 * so we will (correctly) not reexecute them. The key is that
2339 * the remainder of pio's io_child_list, from 'cio_next' onward,
2340 * cannot be affected by any side effects of reexecuting 'cio'.
2342 zio_link_t *zl = NULL;
2343 mutex_enter(&pio->io_lock);
2344 for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) {
2345 cio_next = zio_walk_children(pio, &zl);
2346 for (int w = 0; w < ZIO_WAIT_TYPES; w++)
2347 pio->io_children[cio->io_child_type][w]++;
2348 mutex_exit(&pio->io_lock);
2350 mutex_enter(&pio->io_lock);
2352 mutex_exit(&pio->io_lock);
2355 * Now that all children have been reexecuted, execute the parent.
2356 * We don't reexecute "The Godfather" I/O here as it's the
2357 * responsibility of the caller to wait on it.
2359 if (!(pio->io_flags & ZIO_FLAG_GODFATHER)) {
2360 pio->io_queued_timestamp = gethrtime();
2366 zio_suspend(spa_t *spa, zio_t *zio, zio_suspend_reason_t reason)
2368 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC)
2369 fm_panic("Pool '%s' has encountered an uncorrectable I/O "
2370 "failure and the failure mode property for this pool "
2371 "is set to panic.", spa_name(spa));
2373 cmn_err(CE_WARN, "Pool '%s' has encountered an uncorrectable I/O "
2374 "failure and has been suspended.\n", spa_name(spa));
2376 (void) zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL,
2379 mutex_enter(&spa->spa_suspend_lock);
2381 if (spa->spa_suspend_zio_root == NULL)
2382 spa->spa_suspend_zio_root = zio_root(spa, NULL, NULL,
2383 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
2384 ZIO_FLAG_GODFATHER);
2386 spa->spa_suspended = reason;
2389 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER));
2390 ASSERT(zio != spa->spa_suspend_zio_root);
2391 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
2392 ASSERT(zio_unique_parent(zio) == NULL);
2393 ASSERT(zio->io_stage == ZIO_STAGE_DONE);
2394 zio_add_child(spa->spa_suspend_zio_root, zio);
2397 mutex_exit(&spa->spa_suspend_lock);
2401 zio_resume(spa_t *spa)
2406 * Reexecute all previously suspended i/o.
2408 mutex_enter(&spa->spa_suspend_lock);
2409 spa->spa_suspended = ZIO_SUSPEND_NONE;
2410 cv_broadcast(&spa->spa_suspend_cv);
2411 pio = spa->spa_suspend_zio_root;
2412 spa->spa_suspend_zio_root = NULL;
2413 mutex_exit(&spa->spa_suspend_lock);
2419 return (zio_wait(pio));
2423 zio_resume_wait(spa_t *spa)
2425 mutex_enter(&spa->spa_suspend_lock);
2426 while (spa_suspended(spa))
2427 cv_wait(&spa->spa_suspend_cv, &spa->spa_suspend_lock);
2428 mutex_exit(&spa->spa_suspend_lock);
2432 * ==========================================================================
2435 * A gang block is a collection of small blocks that looks to the DMU
2436 * like one large block. When zio_dva_allocate() cannot find a block
2437 * of the requested size, due to either severe fragmentation or the pool
2438 * being nearly full, it calls zio_write_gang_block() to construct the
2439 * block from smaller fragments.
2441 * A gang block consists of a gang header (zio_gbh_phys_t) and up to
2442 * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like
2443 * an indirect block: it's an array of block pointers. It consumes
2444 * only one sector and hence is allocatable regardless of fragmentation.
2445 * The gang header's bps point to its gang members, which hold the data.
2447 * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg>
2448 * as the verifier to ensure uniqueness of the SHA256 checksum.
2449 * Critically, the gang block bp's blk_cksum is the checksum of the data,
2450 * not the gang header. This ensures that data block signatures (needed for
2451 * deduplication) are independent of how the block is physically stored.
2453 * Gang blocks can be nested: a gang member may itself be a gang block.
2454 * Thus every gang block is a tree in which root and all interior nodes are
2455 * gang headers, and the leaves are normal blocks that contain user data.
2456 * The root of the gang tree is called the gang leader.
2458 * To perform any operation (read, rewrite, free, claim) on a gang block,
2459 * zio_gang_assemble() first assembles the gang tree (minus data leaves)
2460 * in the io_gang_tree field of the original logical i/o by recursively
2461 * reading the gang leader and all gang headers below it. This yields
2462 * an in-core tree containing the contents of every gang header and the
2463 * bps for every constituent of the gang block.
2465 * With the gang tree now assembled, zio_gang_issue() just walks the gang tree
2466 * and invokes a callback on each bp. To free a gang block, zio_gang_issue()
2467 * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp.
2468 * zio_claim_gang() provides a similarly trivial wrapper for zio_claim().
2469 * zio_read_gang() is a wrapper around zio_read() that omits reading gang
2470 * headers, since we already have those in io_gang_tree. zio_rewrite_gang()
2471 * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite()
2472 * of the gang header plus zio_checksum_compute() of the data to update the
2473 * gang header's blk_cksum as described above.
2475 * The two-phase assemble/issue model solves the problem of partial failure --
2476 * what if you'd freed part of a gang block but then couldn't read the
2477 * gang header for another part? Assembling the entire gang tree first
2478 * ensures that all the necessary gang header I/O has succeeded before
2479 * starting the actual work of free, claim, or write. Once the gang tree
2480 * is assembled, free and claim are in-memory operations that cannot fail.
2482 * In the event that a gang write fails, zio_dva_unallocate() walks the
2483 * gang tree to immediately free (i.e. insert back into the space map)
2484 * everything we've allocated. This ensures that we don't get ENOSPC
2485 * errors during repeated suspend/resume cycles due to a flaky device.
2487 * Gang rewrites only happen during sync-to-convergence. If we can't assemble
2488 * the gang tree, we won't modify the block, so we can safely defer the free
2489 * (knowing that the block is still intact). If we *can* assemble the gang
2490 * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free
2491 * each constituent bp and we can allocate a new block on the next sync pass.
2493 * In all cases, the gang tree allows complete recovery from partial failure.
2494 * ==========================================================================
2498 zio_gang_issue_func_done(zio_t *zio)
2500 abd_free(zio->io_abd);
2504 zio_read_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data,
2510 return (zio_read(pio, pio->io_spa, bp, abd_get_offset(data, offset),
2511 BP_GET_PSIZE(bp), zio_gang_issue_func_done,
2512 NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio),
2513 &pio->io_bookmark));
2517 zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data,
2524 abd_get_from_buf(gn->gn_gbh, SPA_GANGBLOCKSIZE);
2525 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp,
2526 gbh_abd, SPA_GANGBLOCKSIZE, zio_gang_issue_func_done, NULL,
2527 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio),
2530 * As we rewrite each gang header, the pipeline will compute
2531 * a new gang block header checksum for it; but no one will
2532 * compute a new data checksum, so we do that here. The one
2533 * exception is the gang leader: the pipeline already computed
2534 * its data checksum because that stage precedes gang assembly.
2535 * (Presently, nothing actually uses interior data checksums;
2536 * this is just good hygiene.)
2538 if (gn != pio->io_gang_leader->io_gang_tree) {
2539 abd_t *buf = abd_get_offset(data, offset);
2541 zio_checksum_compute(zio, BP_GET_CHECKSUM(bp),
2542 buf, BP_GET_PSIZE(bp));
2547 * If we are here to damage data for testing purposes,
2548 * leave the GBH alone so that we can detect the damage.
2550 if (pio->io_gang_leader->io_flags & ZIO_FLAG_INDUCE_DAMAGE)
2551 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES;
2553 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp,
2554 abd_get_offset(data, offset), BP_GET_PSIZE(bp),
2555 zio_gang_issue_func_done, NULL, pio->io_priority,
2556 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark);
2563 zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data,
2566 (void) gn, (void) data, (void) offset;
2568 zio_t *zio = zio_free_sync(pio, pio->io_spa, pio->io_txg, bp,
2569 ZIO_GANG_CHILD_FLAGS(pio));
2571 zio = zio_null(pio, pio->io_spa,
2572 NULL, NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio));
2578 zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data,
2581 (void) gn, (void) data, (void) offset;
2582 return (zio_claim(pio, pio->io_spa, pio->io_txg, bp,
2583 NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio)));
2586 static zio_gang_issue_func_t *zio_gang_issue_func[ZIO_TYPES] = {
2595 static void zio_gang_tree_assemble_done(zio_t *zio);
2597 static zio_gang_node_t *
2598 zio_gang_node_alloc(zio_gang_node_t **gnpp)
2600 zio_gang_node_t *gn;
2602 ASSERT(*gnpp == NULL);
2604 gn = kmem_zalloc(sizeof (*gn), KM_SLEEP);
2605 gn->gn_gbh = zio_buf_alloc(SPA_GANGBLOCKSIZE);
2612 zio_gang_node_free(zio_gang_node_t **gnpp)
2614 zio_gang_node_t *gn = *gnpp;
2616 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++)
2617 ASSERT(gn->gn_child[g] == NULL);
2619 zio_buf_free(gn->gn_gbh, SPA_GANGBLOCKSIZE);
2620 kmem_free(gn, sizeof (*gn));
2625 zio_gang_tree_free(zio_gang_node_t **gnpp)
2627 zio_gang_node_t *gn = *gnpp;
2632 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++)
2633 zio_gang_tree_free(&gn->gn_child[g]);
2635 zio_gang_node_free(gnpp);
2639 zio_gang_tree_assemble(zio_t *gio, blkptr_t *bp, zio_gang_node_t **gnpp)
2641 zio_gang_node_t *gn = zio_gang_node_alloc(gnpp);
2642 abd_t *gbh_abd = abd_get_from_buf(gn->gn_gbh, SPA_GANGBLOCKSIZE);
2644 ASSERT(gio->io_gang_leader == gio);
2645 ASSERT(BP_IS_GANG(bp));
2647 zio_nowait(zio_read(gio, gio->io_spa, bp, gbh_abd, SPA_GANGBLOCKSIZE,
2648 zio_gang_tree_assemble_done, gn, gio->io_priority,
2649 ZIO_GANG_CHILD_FLAGS(gio), &gio->io_bookmark));
2653 zio_gang_tree_assemble_done(zio_t *zio)
2655 zio_t *gio = zio->io_gang_leader;
2656 zio_gang_node_t *gn = zio->io_private;
2657 blkptr_t *bp = zio->io_bp;
2659 ASSERT(gio == zio_unique_parent(zio));
2660 ASSERT(zio->io_child_count == 0);
2665 /* this ABD was created from a linear buf in zio_gang_tree_assemble */
2666 if (BP_SHOULD_BYTESWAP(bp))
2667 byteswap_uint64_array(abd_to_buf(zio->io_abd), zio->io_size);
2669 ASSERT3P(abd_to_buf(zio->io_abd), ==, gn->gn_gbh);
2670 ASSERT(zio->io_size == SPA_GANGBLOCKSIZE);
2671 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC);
2673 abd_free(zio->io_abd);
2675 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) {
2676 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g];
2677 if (!BP_IS_GANG(gbp))
2679 zio_gang_tree_assemble(gio, gbp, &gn->gn_child[g]);
2684 zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, abd_t *data,
2687 zio_t *gio = pio->io_gang_leader;
2690 ASSERT(BP_IS_GANG(bp) == !!gn);
2691 ASSERT(BP_GET_CHECKSUM(bp) == BP_GET_CHECKSUM(gio->io_bp));
2692 ASSERT(BP_GET_LSIZE(bp) == BP_GET_PSIZE(bp) || gn == gio->io_gang_tree);
2695 * If you're a gang header, your data is in gn->gn_gbh.
2696 * If you're a gang member, your data is in 'data' and gn == NULL.
2698 zio = zio_gang_issue_func[gio->io_type](pio, bp, gn, data, offset);
2701 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC);
2703 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) {
2704 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g];
2705 if (BP_IS_HOLE(gbp))
2707 zio_gang_tree_issue(zio, gn->gn_child[g], gbp, data,
2709 offset += BP_GET_PSIZE(gbp);
2713 if (gn == gio->io_gang_tree)
2714 ASSERT3U(gio->io_size, ==, offset);
2721 zio_gang_assemble(zio_t *zio)
2723 blkptr_t *bp = zio->io_bp;
2725 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == NULL);
2726 ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
2728 zio->io_gang_leader = zio;
2730 zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree);
2736 zio_gang_issue(zio_t *zio)
2738 blkptr_t *bp = zio->io_bp;
2740 if (zio_wait_for_children(zio, ZIO_CHILD_GANG_BIT, ZIO_WAIT_DONE)) {
2744 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio);
2745 ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
2747 if (zio->io_child_error[ZIO_CHILD_GANG] == 0)
2748 zio_gang_tree_issue(zio, zio->io_gang_tree, bp, zio->io_abd,
2751 zio_gang_tree_free(&zio->io_gang_tree);
2753 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
2759 zio_write_gang_member_ready(zio_t *zio)
2761 zio_t *pio = zio_unique_parent(zio);
2762 dva_t *cdva = zio->io_bp->blk_dva;
2763 dva_t *pdva = pio->io_bp->blk_dva;
2765 zio_t *gio __maybe_unused = zio->io_gang_leader;
2767 if (BP_IS_HOLE(zio->io_bp))
2770 ASSERT(BP_IS_HOLE(&zio->io_bp_orig));
2772 ASSERT(zio->io_child_type == ZIO_CHILD_GANG);
2773 ASSERT3U(zio->io_prop.zp_copies, ==, gio->io_prop.zp_copies);
2774 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp));
2775 ASSERT3U(pio->io_prop.zp_copies, <=, BP_GET_NDVAS(pio->io_bp));
2776 ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp));
2778 mutex_enter(&pio->io_lock);
2779 for (int d = 0; d < BP_GET_NDVAS(zio->io_bp); d++) {
2780 ASSERT(DVA_GET_GANG(&pdva[d]));
2781 asize = DVA_GET_ASIZE(&pdva[d]);
2782 asize += DVA_GET_ASIZE(&cdva[d]);
2783 DVA_SET_ASIZE(&pdva[d], asize);
2785 mutex_exit(&pio->io_lock);
2789 zio_write_gang_done(zio_t *zio)
2792 * The io_abd field will be NULL for a zio with no data. The io_flags
2793 * will initially have the ZIO_FLAG_NODATA bit flag set, but we can't
2794 * check for it here as it is cleared in zio_ready.
2796 if (zio->io_abd != NULL)
2797 abd_free(zio->io_abd);
2801 zio_write_gang_block(zio_t *pio, metaslab_class_t *mc)
2803 spa_t *spa = pio->io_spa;
2804 blkptr_t *bp = pio->io_bp;
2805 zio_t *gio = pio->io_gang_leader;
2807 zio_gang_node_t *gn, **gnpp;
2808 zio_gbh_phys_t *gbh;
2810 uint64_t txg = pio->io_txg;
2811 uint64_t resid = pio->io_size;
2813 int copies = gio->io_prop.zp_copies;
2817 boolean_t has_data = !(pio->io_flags & ZIO_FLAG_NODATA);
2820 * encrypted blocks need DVA[2] free so encrypted gang headers can't
2821 * have a third copy.
2823 gbh_copies = MIN(copies + 1, spa_max_replication(spa));
2824 if (gio->io_prop.zp_encrypt && gbh_copies >= SPA_DVAS_PER_BP)
2825 gbh_copies = SPA_DVAS_PER_BP - 1;
2827 int flags = METASLAB_HINTBP_FAVOR | METASLAB_GANG_HEADER;
2828 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) {
2829 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE);
2832 flags |= METASLAB_ASYNC_ALLOC;
2833 VERIFY(zfs_refcount_held(&mc->mc_allocator[pio->io_allocator].
2834 mca_alloc_slots, pio));
2837 * The logical zio has already placed a reservation for
2838 * 'copies' allocation slots but gang blocks may require
2839 * additional copies. These additional copies
2840 * (i.e. gbh_copies - copies) are guaranteed to succeed
2841 * since metaslab_class_throttle_reserve() always allows
2842 * additional reservations for gang blocks.
2844 VERIFY(metaslab_class_throttle_reserve(mc, gbh_copies - copies,
2845 pio->io_allocator, pio, flags));
2848 error = metaslab_alloc(spa, mc, SPA_GANGBLOCKSIZE,
2849 bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp, flags,
2850 &pio->io_alloc_list, pio, pio->io_allocator);
2852 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) {
2853 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE);
2857 * If we failed to allocate the gang block header then
2858 * we remove any additional allocation reservations that
2859 * we placed here. The original reservation will
2860 * be removed when the logical I/O goes to the ready
2863 metaslab_class_throttle_unreserve(mc,
2864 gbh_copies - copies, pio->io_allocator, pio);
2867 pio->io_error = error;
2872 gnpp = &gio->io_gang_tree;
2874 gnpp = pio->io_private;
2875 ASSERT(pio->io_ready == zio_write_gang_member_ready);
2878 gn = zio_gang_node_alloc(gnpp);
2880 bzero(gbh, SPA_GANGBLOCKSIZE);
2881 gbh_abd = abd_get_from_buf(gbh, SPA_GANGBLOCKSIZE);
2884 * Create the gang header.
2886 zio = zio_rewrite(pio, spa, txg, bp, gbh_abd, SPA_GANGBLOCKSIZE,
2887 zio_write_gang_done, NULL, pio->io_priority,
2888 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark);
2891 * Create and nowait the gang children.
2893 for (int g = 0; resid != 0; resid -= lsize, g++) {
2894 lsize = P2ROUNDUP(resid / (SPA_GBH_NBLKPTRS - g),
2896 ASSERT(lsize >= SPA_MINBLOCKSIZE && lsize <= resid);
2898 zp.zp_checksum = gio->io_prop.zp_checksum;
2899 zp.zp_compress = ZIO_COMPRESS_OFF;
2900 zp.zp_complevel = gio->io_prop.zp_complevel;
2901 zp.zp_type = DMU_OT_NONE;
2903 zp.zp_copies = gio->io_prop.zp_copies;
2904 zp.zp_dedup = B_FALSE;
2905 zp.zp_dedup_verify = B_FALSE;
2906 zp.zp_nopwrite = B_FALSE;
2907 zp.zp_encrypt = gio->io_prop.zp_encrypt;
2908 zp.zp_byteorder = gio->io_prop.zp_byteorder;
2909 bzero(zp.zp_salt, ZIO_DATA_SALT_LEN);
2910 bzero(zp.zp_iv, ZIO_DATA_IV_LEN);
2911 bzero(zp.zp_mac, ZIO_DATA_MAC_LEN);
2913 zio_t *cio = zio_write(zio, spa, txg, &gbh->zg_blkptr[g],
2914 has_data ? abd_get_offset(pio->io_abd, pio->io_size -
2915 resid) : NULL, lsize, lsize, &zp,
2916 zio_write_gang_member_ready, NULL, NULL,
2917 zio_write_gang_done, &gn->gn_child[g], pio->io_priority,
2918 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark);
2920 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) {
2921 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE);
2925 * Gang children won't throttle but we should
2926 * account for their work, so reserve an allocation
2927 * slot for them here.
2929 VERIFY(metaslab_class_throttle_reserve(mc,
2930 zp.zp_copies, cio->io_allocator, cio, flags));
2936 * Set pio's pipeline to just wait for zio to finish.
2938 pio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
2941 * We didn't allocate this bp, so make sure it doesn't get unmarked.
2943 pio->io_flags &= ~ZIO_FLAG_FASTWRITE;
2951 * The zio_nop_write stage in the pipeline determines if allocating a
2952 * new bp is necessary. The nopwrite feature can handle writes in
2953 * either syncing or open context (i.e. zil writes) and as a result is
2954 * mutually exclusive with dedup.
2956 * By leveraging a cryptographically secure checksum, such as SHA256, we
2957 * can compare the checksums of the new data and the old to determine if
2958 * allocating a new block is required. Note that our requirements for
2959 * cryptographic strength are fairly weak: there can't be any accidental
2960 * hash collisions, but we don't need to be secure against intentional
2961 * (malicious) collisions. To trigger a nopwrite, you have to be able
2962 * to write the file to begin with, and triggering an incorrect (hash
2963 * collision) nopwrite is no worse than simply writing to the file.
2964 * That said, there are no known attacks against the checksum algorithms
2965 * used for nopwrite, assuming that the salt and the checksums
2966 * themselves remain secret.
2969 zio_nop_write(zio_t *zio)
2971 blkptr_t *bp = zio->io_bp;
2972 blkptr_t *bp_orig = &zio->io_bp_orig;
2973 zio_prop_t *zp = &zio->io_prop;
2975 ASSERT(BP_GET_LEVEL(bp) == 0);
2976 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE));
2977 ASSERT(zp->zp_nopwrite);
2978 ASSERT(!zp->zp_dedup);
2979 ASSERT(zio->io_bp_override == NULL);
2980 ASSERT(IO_IS_ALLOCATING(zio));
2983 * Check to see if the original bp and the new bp have matching
2984 * characteristics (i.e. same checksum, compression algorithms, etc).
2985 * If they don't then just continue with the pipeline which will
2986 * allocate a new bp.
2988 if (BP_IS_HOLE(bp_orig) ||
2989 !(zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_flags &
2990 ZCHECKSUM_FLAG_NOPWRITE) ||
2991 BP_IS_ENCRYPTED(bp) || BP_IS_ENCRYPTED(bp_orig) ||
2992 BP_GET_CHECKSUM(bp) != BP_GET_CHECKSUM(bp_orig) ||
2993 BP_GET_COMPRESS(bp) != BP_GET_COMPRESS(bp_orig) ||
2994 BP_GET_DEDUP(bp) != BP_GET_DEDUP(bp_orig) ||
2995 zp->zp_copies != BP_GET_NDVAS(bp_orig))
2999 * If the checksums match then reset the pipeline so that we
3000 * avoid allocating a new bp and issuing any I/O.
3002 if (ZIO_CHECKSUM_EQUAL(bp->blk_cksum, bp_orig->blk_cksum)) {
3003 ASSERT(zio_checksum_table[zp->zp_checksum].ci_flags &
3004 ZCHECKSUM_FLAG_NOPWRITE);
3005 ASSERT3U(BP_GET_PSIZE(bp), ==, BP_GET_PSIZE(bp_orig));
3006 ASSERT3U(BP_GET_LSIZE(bp), ==, BP_GET_LSIZE(bp_orig));
3007 ASSERT(zp->zp_compress != ZIO_COMPRESS_OFF);
3008 ASSERT(bcmp(&bp->blk_prop, &bp_orig->blk_prop,
3009 sizeof (uint64_t)) == 0);
3012 * If we're overwriting a block that is currently on an
3013 * indirect vdev, then ignore the nopwrite request and
3014 * allow a new block to be allocated on a concrete vdev.
3016 spa_config_enter(zio->io_spa, SCL_VDEV, FTAG, RW_READER);
3017 vdev_t *tvd = vdev_lookup_top(zio->io_spa,
3018 DVA_GET_VDEV(&bp->blk_dva[0]));
3019 if (tvd->vdev_ops == &vdev_indirect_ops) {
3020 spa_config_exit(zio->io_spa, SCL_VDEV, FTAG);
3023 spa_config_exit(zio->io_spa, SCL_VDEV, FTAG);
3026 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
3027 zio->io_flags |= ZIO_FLAG_NOPWRITE;
3034 * ==========================================================================
3036 * ==========================================================================
3039 zio_ddt_child_read_done(zio_t *zio)
3041 blkptr_t *bp = zio->io_bp;
3042 ddt_entry_t *dde = zio->io_private;
3044 zio_t *pio = zio_unique_parent(zio);
3046 mutex_enter(&pio->io_lock);
3047 ddp = ddt_phys_select(dde, bp);
3048 if (zio->io_error == 0)
3049 ddt_phys_clear(ddp); /* this ddp doesn't need repair */
3051 if (zio->io_error == 0 && dde->dde_repair_abd == NULL)
3052 dde->dde_repair_abd = zio->io_abd;
3054 abd_free(zio->io_abd);
3055 mutex_exit(&pio->io_lock);
3059 zio_ddt_read_start(zio_t *zio)
3061 blkptr_t *bp = zio->io_bp;
3063 ASSERT(BP_GET_DEDUP(bp));
3064 ASSERT(BP_GET_PSIZE(bp) == zio->io_size);
3065 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
3067 if (zio->io_child_error[ZIO_CHILD_DDT]) {
3068 ddt_t *ddt = ddt_select(zio->io_spa, bp);
3069 ddt_entry_t *dde = ddt_repair_start(ddt, bp);
3070 ddt_phys_t *ddp = dde->dde_phys;
3071 ddt_phys_t *ddp_self = ddt_phys_select(dde, bp);
3074 ASSERT(zio->io_vsd == NULL);
3077 if (ddp_self == NULL)
3080 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
3081 if (ddp->ddp_phys_birth == 0 || ddp == ddp_self)
3083 ddt_bp_create(ddt->ddt_checksum, &dde->dde_key, ddp,
3085 zio_nowait(zio_read(zio, zio->io_spa, &blk,
3086 abd_alloc_for_io(zio->io_size, B_TRUE),
3087 zio->io_size, zio_ddt_child_read_done, dde,
3088 zio->io_priority, ZIO_DDT_CHILD_FLAGS(zio) |
3089 ZIO_FLAG_DONT_PROPAGATE, &zio->io_bookmark));
3094 zio_nowait(zio_read(zio, zio->io_spa, bp,
3095 zio->io_abd, zio->io_size, NULL, NULL, zio->io_priority,
3096 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark));
3102 zio_ddt_read_done(zio_t *zio)
3104 blkptr_t *bp = zio->io_bp;
3106 if (zio_wait_for_children(zio, ZIO_CHILD_DDT_BIT, ZIO_WAIT_DONE)) {
3110 ASSERT(BP_GET_DEDUP(bp));
3111 ASSERT(BP_GET_PSIZE(bp) == zio->io_size);
3112 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
3114 if (zio->io_child_error[ZIO_CHILD_DDT]) {
3115 ddt_t *ddt = ddt_select(zio->io_spa, bp);
3116 ddt_entry_t *dde = zio->io_vsd;
3118 ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE);
3122 zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1;
3123 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE);
3126 if (dde->dde_repair_abd != NULL) {
3127 abd_copy(zio->io_abd, dde->dde_repair_abd,
3129 zio->io_child_error[ZIO_CHILD_DDT] = 0;
3131 ddt_repair_done(ddt, dde);
3135 ASSERT(zio->io_vsd == NULL);
3141 zio_ddt_collision(zio_t *zio, ddt_t *ddt, ddt_entry_t *dde)
3143 spa_t *spa = zio->io_spa;
3144 boolean_t do_raw = !!(zio->io_flags & ZIO_FLAG_RAW);
3146 ASSERT(!(zio->io_bp_override && do_raw));
3149 * Note: we compare the original data, not the transformed data,
3150 * because when zio->io_bp is an override bp, we will not have
3151 * pushed the I/O transforms. That's an important optimization
3152 * because otherwise we'd compress/encrypt all dmu_sync() data twice.
3153 * However, we should never get a raw, override zio so in these
3154 * cases we can compare the io_abd directly. This is useful because
3155 * it allows us to do dedup verification even if we don't have access
3156 * to the original data (for instance, if the encryption keys aren't
3160 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) {
3161 zio_t *lio = dde->dde_lead_zio[p];
3163 if (lio != NULL && do_raw) {
3164 return (lio->io_size != zio->io_size ||
3165 abd_cmp(zio->io_abd, lio->io_abd) != 0);
3166 } else if (lio != NULL) {
3167 return (lio->io_orig_size != zio->io_orig_size ||
3168 abd_cmp(zio->io_orig_abd, lio->io_orig_abd) != 0);
3172 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) {
3173 ddt_phys_t *ddp = &dde->dde_phys[p];
3175 if (ddp->ddp_phys_birth != 0 && do_raw) {
3176 blkptr_t blk = *zio->io_bp;
3181 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth);
3182 psize = BP_GET_PSIZE(&blk);
3184 if (psize != zio->io_size)
3189 tmpabd = abd_alloc_for_io(psize, B_TRUE);
3191 error = zio_wait(zio_read(NULL, spa, &blk, tmpabd,
3192 psize, NULL, NULL, ZIO_PRIORITY_SYNC_READ,
3193 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
3194 ZIO_FLAG_RAW, &zio->io_bookmark));
3197 if (abd_cmp(tmpabd, zio->io_abd) != 0)
3198 error = SET_ERROR(ENOENT);
3203 return (error != 0);
3204 } else if (ddp->ddp_phys_birth != 0) {
3205 arc_buf_t *abuf = NULL;
3206 arc_flags_t aflags = ARC_FLAG_WAIT;
3207 blkptr_t blk = *zio->io_bp;
3210 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth);
3212 if (BP_GET_LSIZE(&blk) != zio->io_orig_size)
3217 error = arc_read(NULL, spa, &blk,
3218 arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ,
3219 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
3220 &aflags, &zio->io_bookmark);
3223 if (abd_cmp_buf(zio->io_orig_abd, abuf->b_data,
3224 zio->io_orig_size) != 0)
3225 error = SET_ERROR(ENOENT);
3226 arc_buf_destroy(abuf, &abuf);
3230 return (error != 0);
3238 zio_ddt_child_write_ready(zio_t *zio)
3240 int p = zio->io_prop.zp_copies;
3241 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp);
3242 ddt_entry_t *dde = zio->io_private;
3243 ddt_phys_t *ddp = &dde->dde_phys[p];
3251 ASSERT(dde->dde_lead_zio[p] == zio);
3253 ddt_phys_fill(ddp, zio->io_bp);
3255 zio_link_t *zl = NULL;
3256 while ((pio = zio_walk_parents(zio, &zl)) != NULL)
3257 ddt_bp_fill(ddp, pio->io_bp, zio->io_txg);
3263 zio_ddt_child_write_done(zio_t *zio)
3265 int p = zio->io_prop.zp_copies;
3266 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp);
3267 ddt_entry_t *dde = zio->io_private;
3268 ddt_phys_t *ddp = &dde->dde_phys[p];
3272 ASSERT(ddp->ddp_refcnt == 0);
3273 ASSERT(dde->dde_lead_zio[p] == zio);
3274 dde->dde_lead_zio[p] = NULL;
3276 if (zio->io_error == 0) {
3277 zio_link_t *zl = NULL;
3278 while (zio_walk_parents(zio, &zl) != NULL)
3279 ddt_phys_addref(ddp);
3281 ddt_phys_clear(ddp);
3288 zio_ddt_write(zio_t *zio)
3290 spa_t *spa = zio->io_spa;
3291 blkptr_t *bp = zio->io_bp;
3292 uint64_t txg = zio->io_txg;
3293 zio_prop_t *zp = &zio->io_prop;
3294 int p = zp->zp_copies;
3296 ddt_t *ddt = ddt_select(spa, bp);
3300 ASSERT(BP_GET_DEDUP(bp));
3301 ASSERT(BP_GET_CHECKSUM(bp) == zp->zp_checksum);
3302 ASSERT(BP_IS_HOLE(bp) || zio->io_bp_override);
3303 ASSERT(!(zio->io_bp_override && (zio->io_flags & ZIO_FLAG_RAW)));
3306 dde = ddt_lookup(ddt, bp, B_TRUE);
3307 ddp = &dde->dde_phys[p];
3309 if (zp->zp_dedup_verify && zio_ddt_collision(zio, ddt, dde)) {
3311 * If we're using a weak checksum, upgrade to a strong checksum
3312 * and try again. If we're already using a strong checksum,
3313 * we can't resolve it, so just convert to an ordinary write.
3314 * (And automatically e-mail a paper to Nature?)
3316 if (!(zio_checksum_table[zp->zp_checksum].ci_flags &
3317 ZCHECKSUM_FLAG_DEDUP)) {
3318 zp->zp_checksum = spa_dedup_checksum(spa);
3319 zio_pop_transforms(zio);
3320 zio->io_stage = ZIO_STAGE_OPEN;
3323 zp->zp_dedup = B_FALSE;
3324 BP_SET_DEDUP(bp, B_FALSE);
3326 ASSERT(!BP_GET_DEDUP(bp));
3327 zio->io_pipeline = ZIO_WRITE_PIPELINE;
3332 if (ddp->ddp_phys_birth != 0 || dde->dde_lead_zio[p] != NULL) {
3333 if (ddp->ddp_phys_birth != 0)
3334 ddt_bp_fill(ddp, bp, txg);
3335 if (dde->dde_lead_zio[p] != NULL)
3336 zio_add_child(zio, dde->dde_lead_zio[p]);
3338 ddt_phys_addref(ddp);
3339 } else if (zio->io_bp_override) {
3340 ASSERT(bp->blk_birth == txg);
3341 ASSERT(BP_EQUAL(bp, zio->io_bp_override));
3342 ddt_phys_fill(ddp, bp);
3343 ddt_phys_addref(ddp);
3345 cio = zio_write(zio, spa, txg, bp, zio->io_orig_abd,
3346 zio->io_orig_size, zio->io_orig_size, zp,
3347 zio_ddt_child_write_ready, NULL, NULL,
3348 zio_ddt_child_write_done, dde, zio->io_priority,
3349 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark);
3351 zio_push_transform(cio, zio->io_abd, zio->io_size, 0, NULL);
3352 dde->dde_lead_zio[p] = cio;
3362 ddt_entry_t *freedde; /* for debugging */
3365 zio_ddt_free(zio_t *zio)
3367 spa_t *spa = zio->io_spa;
3368 blkptr_t *bp = zio->io_bp;
3369 ddt_t *ddt = ddt_select(spa, bp);
3373 ASSERT(BP_GET_DEDUP(bp));
3374 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
3377 freedde = dde = ddt_lookup(ddt, bp, B_TRUE);
3379 ddp = ddt_phys_select(dde, bp);
3381 ddt_phys_decref(ddp);
3389 * ==========================================================================
3390 * Allocate and free blocks
3391 * ==========================================================================
3395 zio_io_to_allocate(spa_t *spa, int allocator)
3399 ASSERT(MUTEX_HELD(&spa->spa_allocs[allocator].spaa_lock));
3401 zio = avl_first(&spa->spa_allocs[allocator].spaa_tree);
3405 ASSERT(IO_IS_ALLOCATING(zio));
3408 * Try to place a reservation for this zio. If we're unable to
3409 * reserve then we throttle.
3411 ASSERT3U(zio->io_allocator, ==, allocator);
3412 if (!metaslab_class_throttle_reserve(zio->io_metaslab_class,
3413 zio->io_prop.zp_copies, allocator, zio, 0)) {
3417 avl_remove(&spa->spa_allocs[allocator].spaa_tree, zio);
3418 ASSERT3U(zio->io_stage, <, ZIO_STAGE_DVA_ALLOCATE);
3424 zio_dva_throttle(zio_t *zio)
3426 spa_t *spa = zio->io_spa;
3428 metaslab_class_t *mc;
3430 /* locate an appropriate allocation class */
3431 mc = spa_preferred_class(spa, zio->io_size, zio->io_prop.zp_type,
3432 zio->io_prop.zp_level, zio->io_prop.zp_zpl_smallblk);
3434 if (zio->io_priority == ZIO_PRIORITY_SYNC_WRITE ||
3435 !mc->mc_alloc_throttle_enabled ||
3436 zio->io_child_type == ZIO_CHILD_GANG ||
3437 zio->io_flags & ZIO_FLAG_NODATA) {
3441 ASSERT(zio->io_type == ZIO_TYPE_WRITE);
3442 ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
3443 ASSERT3U(zio->io_queued_timestamp, >, 0);
3444 ASSERT(zio->io_stage == ZIO_STAGE_DVA_THROTTLE);
3446 zbookmark_phys_t *bm = &zio->io_bookmark;
3448 * We want to try to use as many allocators as possible to help improve
3449 * performance, but we also want logically adjacent IOs to be physically
3450 * adjacent to improve sequential read performance. We chunk each object
3451 * into 2^20 block regions, and then hash based on the objset, object,
3452 * level, and region to accomplish both of these goals.
3454 int allocator = (uint_t)cityhash4(bm->zb_objset, bm->zb_object,
3455 bm->zb_level, bm->zb_blkid >> 20) % spa->spa_alloc_count;
3456 zio->io_allocator = allocator;
3457 zio->io_metaslab_class = mc;
3458 mutex_enter(&spa->spa_allocs[allocator].spaa_lock);
3459 avl_add(&spa->spa_allocs[allocator].spaa_tree, zio);
3460 nio = zio_io_to_allocate(spa, allocator);
3461 mutex_exit(&spa->spa_allocs[allocator].spaa_lock);
3466 zio_allocate_dispatch(spa_t *spa, int allocator)
3470 mutex_enter(&spa->spa_allocs[allocator].spaa_lock);
3471 zio = zio_io_to_allocate(spa, allocator);
3472 mutex_exit(&spa->spa_allocs[allocator].spaa_lock);
3476 ASSERT3U(zio->io_stage, ==, ZIO_STAGE_DVA_THROTTLE);
3477 ASSERT0(zio->io_error);
3478 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_TRUE);
3482 zio_dva_allocate(zio_t *zio)
3484 spa_t *spa = zio->io_spa;
3485 metaslab_class_t *mc;
3486 blkptr_t *bp = zio->io_bp;
3490 if (zio->io_gang_leader == NULL) {
3491 ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
3492 zio->io_gang_leader = zio;
3495 ASSERT(BP_IS_HOLE(bp));
3496 ASSERT0(BP_GET_NDVAS(bp));
3497 ASSERT3U(zio->io_prop.zp_copies, >, 0);
3498 ASSERT3U(zio->io_prop.zp_copies, <=, spa_max_replication(spa));
3499 ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp));
3501 flags |= (zio->io_flags & ZIO_FLAG_FASTWRITE) ? METASLAB_FASTWRITE : 0;
3502 if (zio->io_flags & ZIO_FLAG_NODATA)
3503 flags |= METASLAB_DONT_THROTTLE;
3504 if (zio->io_flags & ZIO_FLAG_GANG_CHILD)
3505 flags |= METASLAB_GANG_CHILD;
3506 if (zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE)
3507 flags |= METASLAB_ASYNC_ALLOC;
3510 * if not already chosen, locate an appropriate allocation class
3512 mc = zio->io_metaslab_class;
3514 mc = spa_preferred_class(spa, zio->io_size,
3515 zio->io_prop.zp_type, zio->io_prop.zp_level,
3516 zio->io_prop.zp_zpl_smallblk);
3517 zio->io_metaslab_class = mc;
3521 * Try allocating the block in the usual metaslab class.
3522 * If that's full, allocate it in the normal class.
3523 * If that's full, allocate as a gang block,
3524 * and if all are full, the allocation fails (which shouldn't happen).
3526 * Note that we do not fall back on embedded slog (ZIL) space, to
3527 * preserve unfragmented slog space, which is critical for decent
3528 * sync write performance. If a log allocation fails, we will fall
3529 * back to spa_sync() which is abysmal for performance.
3531 error = metaslab_alloc(spa, mc, zio->io_size, bp,
3532 zio->io_prop.zp_copies, zio->io_txg, NULL, flags,
3533 &zio->io_alloc_list, zio, zio->io_allocator);
3536 * Fallback to normal class when an alloc class is full
3538 if (error == ENOSPC && mc != spa_normal_class(spa)) {
3540 * If throttling, transfer reservation over to normal class.
3541 * The io_allocator slot can remain the same even though we
3542 * are switching classes.
3544 if (mc->mc_alloc_throttle_enabled &&
3545 (zio->io_flags & ZIO_FLAG_IO_ALLOCATING)) {
3546 metaslab_class_throttle_unreserve(mc,
3547 zio->io_prop.zp_copies, zio->io_allocator, zio);
3548 zio->io_flags &= ~ZIO_FLAG_IO_ALLOCATING;
3550 VERIFY(metaslab_class_throttle_reserve(
3551 spa_normal_class(spa),
3552 zio->io_prop.zp_copies, zio->io_allocator, zio,
3553 flags | METASLAB_MUST_RESERVE));
3555 zio->io_metaslab_class = mc = spa_normal_class(spa);
3556 if (zfs_flags & ZFS_DEBUG_METASLAB_ALLOC) {
3557 zfs_dbgmsg("%s: metaslab allocation failure, "
3558 "trying normal class: zio %px, size %llu, error %d",
3559 spa_name(spa), zio, (u_longlong_t)zio->io_size,
3563 error = metaslab_alloc(spa, mc, zio->io_size, bp,
3564 zio->io_prop.zp_copies, zio->io_txg, NULL, flags,
3565 &zio->io_alloc_list, zio, zio->io_allocator);
3568 if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE) {
3569 if (zfs_flags & ZFS_DEBUG_METASLAB_ALLOC) {
3570 zfs_dbgmsg("%s: metaslab allocation failure, "
3571 "trying ganging: zio %px, size %llu, error %d",
3572 spa_name(spa), zio, (u_longlong_t)zio->io_size,
3575 return (zio_write_gang_block(zio, mc));
3578 if (error != ENOSPC ||
3579 (zfs_flags & ZFS_DEBUG_METASLAB_ALLOC)) {
3580 zfs_dbgmsg("%s: metaslab allocation failure: zio %px, "
3581 "size %llu, error %d",
3582 spa_name(spa), zio, (u_longlong_t)zio->io_size,
3585 zio->io_error = error;
3592 zio_dva_free(zio_t *zio)
3594 metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE);
3600 zio_dva_claim(zio_t *zio)
3604 error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg);
3606 zio->io_error = error;
3612 * Undo an allocation. This is used by zio_done() when an I/O fails
3613 * and we want to give back the block we just allocated.
3614 * This handles both normal blocks and gang blocks.
3617 zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp)
3619 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp));
3620 ASSERT(zio->io_bp_override == NULL);
3622 if (!BP_IS_HOLE(bp))
3623 metaslab_free(zio->io_spa, bp, bp->blk_birth, B_TRUE);
3626 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) {
3627 zio_dva_unallocate(zio, gn->gn_child[g],
3628 &gn->gn_gbh->zg_blkptr[g]);
3634 * Try to allocate an intent log block. Return 0 on success, errno on failure.
3637 zio_alloc_zil(spa_t *spa, objset_t *os, uint64_t txg, blkptr_t *new_bp,
3638 uint64_t size, boolean_t *slog)
3641 zio_alloc_list_t io_alloc_list;
3643 ASSERT(txg > spa_syncing_txg(spa));
3645 metaslab_trace_init(&io_alloc_list);
3648 * Block pointer fields are useful to metaslabs for stats and debugging.
3649 * Fill in the obvious ones before calling into metaslab_alloc().
3651 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG);
3652 BP_SET_PSIZE(new_bp, size);
3653 BP_SET_LEVEL(new_bp, 0);
3656 * When allocating a zil block, we don't have information about
3657 * the final destination of the block except the objset it's part
3658 * of, so we just hash the objset ID to pick the allocator to get
3661 int flags = METASLAB_FASTWRITE | METASLAB_ZIL;
3662 int allocator = (uint_t)cityhash4(0, 0, 0,
3663 os->os_dsl_dataset->ds_object) % spa->spa_alloc_count;
3664 error = metaslab_alloc(spa, spa_log_class(spa), size, new_bp, 1,
3665 txg, NULL, flags, &io_alloc_list, NULL, allocator);
3666 *slog = (error == 0);
3668 error = metaslab_alloc(spa, spa_embedded_log_class(spa), size,
3669 new_bp, 1, txg, NULL, flags,
3670 &io_alloc_list, NULL, allocator);
3673 error = metaslab_alloc(spa, spa_normal_class(spa), size,
3674 new_bp, 1, txg, NULL, flags,
3675 &io_alloc_list, NULL, allocator);
3677 metaslab_trace_fini(&io_alloc_list);
3680 BP_SET_LSIZE(new_bp, size);
3681 BP_SET_PSIZE(new_bp, size);
3682 BP_SET_COMPRESS(new_bp, ZIO_COMPRESS_OFF);
3683 BP_SET_CHECKSUM(new_bp,
3684 spa_version(spa) >= SPA_VERSION_SLIM_ZIL
3685 ? ZIO_CHECKSUM_ZILOG2 : ZIO_CHECKSUM_ZILOG);
3686 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG);
3687 BP_SET_LEVEL(new_bp, 0);
3688 BP_SET_DEDUP(new_bp, 0);
3689 BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER);
3692 * encrypted blocks will require an IV and salt. We generate
3693 * these now since we will not be rewriting the bp at
3696 if (os->os_encrypted) {
3697 uint8_t iv[ZIO_DATA_IV_LEN];
3698 uint8_t salt[ZIO_DATA_SALT_LEN];
3700 BP_SET_CRYPT(new_bp, B_TRUE);
3701 VERIFY0(spa_crypt_get_salt(spa,
3702 dmu_objset_id(os), salt));
3703 VERIFY0(zio_crypt_generate_iv(iv));
3705 zio_crypt_encode_params_bp(new_bp, salt, iv);
3708 zfs_dbgmsg("%s: zil block allocation failure: "
3709 "size %llu, error %d", spa_name(spa), (u_longlong_t)size,
3717 * ==========================================================================
3718 * Read and write to physical devices
3719 * ==========================================================================
3723 * Issue an I/O to the underlying vdev. Typically the issue pipeline
3724 * stops after this stage and will resume upon I/O completion.
3725 * However, there are instances where the vdev layer may need to
3726 * continue the pipeline when an I/O was not issued. Since the I/O
3727 * that was sent to the vdev layer might be different than the one
3728 * currently active in the pipeline (see vdev_queue_io()), we explicitly
3729 * force the underlying vdev layers to call either zio_execute() or
3730 * zio_interrupt() to ensure that the pipeline continues with the correct I/O.
3733 zio_vdev_io_start(zio_t *zio)
3735 vdev_t *vd = zio->io_vd;
3737 spa_t *spa = zio->io_spa;
3741 ASSERT(zio->io_error == 0);
3742 ASSERT(zio->io_child_error[ZIO_CHILD_VDEV] == 0);
3745 if (!(zio->io_flags & ZIO_FLAG_CONFIG_WRITER))
3746 spa_config_enter(spa, SCL_ZIO, zio, RW_READER);
3749 * The mirror_ops handle multiple DVAs in a single BP.
3751 vdev_mirror_ops.vdev_op_io_start(zio);
3755 ASSERT3P(zio->io_logical, !=, zio);
3756 if (zio->io_type == ZIO_TYPE_WRITE) {
3757 ASSERT(spa->spa_trust_config);
3760 * Note: the code can handle other kinds of writes,
3761 * but we don't expect them.
3763 if (zio->io_vd->vdev_noalloc) {
3764 ASSERT(zio->io_flags &
3765 (ZIO_FLAG_PHYSICAL | ZIO_FLAG_SELF_HEAL |
3766 ZIO_FLAG_RESILVER | ZIO_FLAG_INDUCE_DAMAGE));
3770 align = 1ULL << vd->vdev_top->vdev_ashift;
3772 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL) &&
3773 P2PHASE(zio->io_size, align) != 0) {
3774 /* Transform logical writes to be a full physical block size. */
3775 uint64_t asize = P2ROUNDUP(zio->io_size, align);
3776 abd_t *abuf = abd_alloc_sametype(zio->io_abd, asize);
3777 ASSERT(vd == vd->vdev_top);
3778 if (zio->io_type == ZIO_TYPE_WRITE) {
3779 abd_copy(abuf, zio->io_abd, zio->io_size);
3780 abd_zero_off(abuf, zio->io_size, asize - zio->io_size);
3782 zio_push_transform(zio, abuf, asize, asize, zio_subblock);
3786 * If this is not a physical io, make sure that it is properly aligned
3787 * before proceeding.
3789 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL)) {
3790 ASSERT0(P2PHASE(zio->io_offset, align));
3791 ASSERT0(P2PHASE(zio->io_size, align));
3794 * For physical writes, we allow 512b aligned writes and assume
3795 * the device will perform a read-modify-write as necessary.
3797 ASSERT0(P2PHASE(zio->io_offset, SPA_MINBLOCKSIZE));
3798 ASSERT0(P2PHASE(zio->io_size, SPA_MINBLOCKSIZE));
3801 VERIFY(zio->io_type != ZIO_TYPE_WRITE || spa_writeable(spa));
3804 * If this is a repair I/O, and there's no self-healing involved --
3805 * that is, we're just resilvering what we expect to resilver --
3806 * then don't do the I/O unless zio's txg is actually in vd's DTL.
3807 * This prevents spurious resilvering.
3809 * There are a few ways that we can end up creating these spurious
3812 * 1. A resilver i/o will be issued if any DVA in the BP has a
3813 * dirty DTL. The mirror code will issue resilver writes to
3814 * each DVA, including the one(s) that are not on vdevs with dirty
3817 * 2. With nested replication, which happens when we have a
3818 * "replacing" or "spare" vdev that's a child of a mirror or raidz.
3819 * For example, given mirror(replacing(A+B), C), it's likely that
3820 * only A is out of date (it's the new device). In this case, we'll
3821 * read from C, then use the data to resilver A+B -- but we don't
3822 * actually want to resilver B, just A. The top-level mirror has no
3823 * way to know this, so instead we just discard unnecessary repairs
3824 * as we work our way down the vdev tree.
3826 * 3. ZTEST also creates mirrors of mirrors, mirrors of raidz, etc.
3827 * The same logic applies to any form of nested replication: ditto
3828 * + mirror, RAID-Z + replacing, etc.
3830 * However, indirect vdevs point off to other vdevs which may have
3831 * DTL's, so we never bypass them. The child i/os on concrete vdevs
3832 * will be properly bypassed instead.
3834 * Leaf DTL_PARTIAL can be empty when a legitimate write comes from
3835 * a dRAID spare vdev. For example, when a dRAID spare is first
3836 * used, its spare blocks need to be written to but the leaf vdev's
3837 * of such blocks can have empty DTL_PARTIAL.
3839 * There seemed no clean way to allow such writes while bypassing
3840 * spurious ones. At this point, just avoid all bypassing for dRAID
3843 if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) &&
3844 !(zio->io_flags & ZIO_FLAG_SELF_HEAL) &&
3845 zio->io_txg != 0 && /* not a delegated i/o */
3846 vd->vdev_ops != &vdev_indirect_ops &&
3847 vd->vdev_top->vdev_ops != &vdev_draid_ops &&
3848 !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) {
3849 ASSERT(zio->io_type == ZIO_TYPE_WRITE);
3850 zio_vdev_io_bypass(zio);
3855 * Select the next best leaf I/O to process. Distributed spares are
3856 * excluded since they dispatch the I/O directly to a leaf vdev after
3857 * applying the dRAID mapping.
3859 if (vd->vdev_ops->vdev_op_leaf &&
3860 vd->vdev_ops != &vdev_draid_spare_ops &&
3861 (zio->io_type == ZIO_TYPE_READ ||
3862 zio->io_type == ZIO_TYPE_WRITE ||
3863 zio->io_type == ZIO_TYPE_TRIM)) {
3865 if (zio->io_type == ZIO_TYPE_READ && vdev_cache_read(zio))
3868 if ((zio = vdev_queue_io(zio)) == NULL)
3871 if (!vdev_accessible(vd, zio)) {
3872 zio->io_error = SET_ERROR(ENXIO);
3876 zio->io_delay = gethrtime();
3879 vd->vdev_ops->vdev_op_io_start(zio);
3884 zio_vdev_io_done(zio_t *zio)
3886 vdev_t *vd = zio->io_vd;
3887 vdev_ops_t *ops = vd ? vd->vdev_ops : &vdev_mirror_ops;
3888 boolean_t unexpected_error = B_FALSE;
3890 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV_BIT, ZIO_WAIT_DONE)) {
3894 ASSERT(zio->io_type == ZIO_TYPE_READ ||
3895 zio->io_type == ZIO_TYPE_WRITE || zio->io_type == ZIO_TYPE_TRIM);
3898 zio->io_delay = gethrtime() - zio->io_delay;
3900 if (vd != NULL && vd->vdev_ops->vdev_op_leaf &&
3901 vd->vdev_ops != &vdev_draid_spare_ops) {
3902 vdev_queue_io_done(zio);
3904 if (zio->io_type == ZIO_TYPE_WRITE)
3905 vdev_cache_write(zio);
3907 if (zio_injection_enabled && zio->io_error == 0)
3908 zio->io_error = zio_handle_device_injections(vd, zio,
3911 if (zio_injection_enabled && zio->io_error == 0)
3912 zio->io_error = zio_handle_label_injection(zio, EIO);
3914 if (zio->io_error && zio->io_type != ZIO_TYPE_TRIM) {
3915 if (!vdev_accessible(vd, zio)) {
3916 zio->io_error = SET_ERROR(ENXIO);
3918 unexpected_error = B_TRUE;
3923 ops->vdev_op_io_done(zio);
3925 if (unexpected_error)
3926 VERIFY(vdev_probe(vd, zio) == NULL);
3932 * This function is used to change the priority of an existing zio that is
3933 * currently in-flight. This is used by the arc to upgrade priority in the
3934 * event that a demand read is made for a block that is currently queued
3935 * as a scrub or async read IO. Otherwise, the high priority read request
3936 * would end up having to wait for the lower priority IO.
3939 zio_change_priority(zio_t *pio, zio_priority_t priority)
3941 zio_t *cio, *cio_next;
3942 zio_link_t *zl = NULL;
3944 ASSERT3U(priority, <, ZIO_PRIORITY_NUM_QUEUEABLE);
3946 if (pio->io_vd != NULL && pio->io_vd->vdev_ops->vdev_op_leaf) {
3947 vdev_queue_change_io_priority(pio, priority);
3949 pio->io_priority = priority;
3952 mutex_enter(&pio->io_lock);
3953 for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) {
3954 cio_next = zio_walk_children(pio, &zl);
3955 zio_change_priority(cio, priority);
3957 mutex_exit(&pio->io_lock);
3961 * For non-raidz ZIOs, we can just copy aside the bad data read from the
3962 * disk, and use that to finish the checksum ereport later.
3965 zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr,
3966 const abd_t *good_buf)
3968 /* no processing needed */
3969 zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE);
3973 zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr)
3975 void *abd = abd_alloc_sametype(zio->io_abd, zio->io_size);
3977 abd_copy(abd, zio->io_abd, zio->io_size);
3979 zcr->zcr_cbinfo = zio->io_size;
3980 zcr->zcr_cbdata = abd;
3981 zcr->zcr_finish = zio_vsd_default_cksum_finish;
3982 zcr->zcr_free = zio_abd_free;
3986 zio_vdev_io_assess(zio_t *zio)
3988 vdev_t *vd = zio->io_vd;
3990 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV_BIT, ZIO_WAIT_DONE)) {
3994 if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER))
3995 spa_config_exit(zio->io_spa, SCL_ZIO, zio);
3997 if (zio->io_vsd != NULL) {
3998 zio->io_vsd_ops->vsd_free(zio);
4002 if (zio_injection_enabled && zio->io_error == 0)
4003 zio->io_error = zio_handle_fault_injection(zio, EIO);
4006 * If the I/O failed, determine whether we should attempt to retry it.
4008 * On retry, we cut in line in the issue queue, since we don't want
4009 * compression/checksumming/etc. work to prevent our (cheap) IO reissue.
4011 if (zio->io_error && vd == NULL &&
4012 !(zio->io_flags & (ZIO_FLAG_DONT_RETRY | ZIO_FLAG_IO_RETRY))) {
4013 ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_QUEUE)); /* not a leaf */
4014 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_BYPASS)); /* not a leaf */
4016 zio->io_flags |= ZIO_FLAG_IO_RETRY |
4017 ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE;
4018 zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1;
4019 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE,
4020 zio_requeue_io_start_cut_in_line);
4025 * If we got an error on a leaf device, convert it to ENXIO
4026 * if the device is not accessible at all.
4028 if (zio->io_error && vd != NULL && vd->vdev_ops->vdev_op_leaf &&
4029 !vdev_accessible(vd, zio))
4030 zio->io_error = SET_ERROR(ENXIO);
4033 * If we can't write to an interior vdev (mirror or RAID-Z),
4034 * set vdev_cant_write so that we stop trying to allocate from it.
4036 if (zio->io_error == ENXIO && zio->io_type == ZIO_TYPE_WRITE &&
4037 vd != NULL && !vd->vdev_ops->vdev_op_leaf) {
4038 vdev_dbgmsg(vd, "zio_vdev_io_assess(zio=%px) setting "
4039 "cant_write=TRUE due to write failure with ENXIO",
4041 vd->vdev_cant_write = B_TRUE;
4045 * If a cache flush returns ENOTSUP or ENOTTY, we know that no future
4046 * attempts will ever succeed. In this case we set a persistent
4047 * boolean flag so that we don't bother with it in the future.
4049 if ((zio->io_error == ENOTSUP || zio->io_error == ENOTTY) &&
4050 zio->io_type == ZIO_TYPE_IOCTL &&
4051 zio->io_cmd == DKIOCFLUSHWRITECACHE && vd != NULL)
4052 vd->vdev_nowritecache = B_TRUE;
4055 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
4057 if (vd != NULL && vd->vdev_ops->vdev_op_leaf &&
4058 zio->io_physdone != NULL) {
4059 ASSERT(!(zio->io_flags & ZIO_FLAG_DELEGATED));
4060 ASSERT(zio->io_child_type == ZIO_CHILD_VDEV);
4061 zio->io_physdone(zio->io_logical);
4068 zio_vdev_io_reissue(zio_t *zio)
4070 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START);
4071 ASSERT(zio->io_error == 0);
4073 zio->io_stage >>= 1;
4077 zio_vdev_io_redone(zio_t *zio)
4079 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE);
4081 zio->io_stage >>= 1;
4085 zio_vdev_io_bypass(zio_t *zio)
4087 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START);
4088 ASSERT(zio->io_error == 0);
4090 zio->io_flags |= ZIO_FLAG_IO_BYPASS;
4091 zio->io_stage = ZIO_STAGE_VDEV_IO_ASSESS >> 1;
4095 * ==========================================================================
4096 * Encrypt and store encryption parameters
4097 * ==========================================================================
4102 * This function is used for ZIO_STAGE_ENCRYPT. It is responsible for
4103 * managing the storage of encryption parameters and passing them to the
4104 * lower-level encryption functions.
4107 zio_encrypt(zio_t *zio)
4109 zio_prop_t *zp = &zio->io_prop;
4110 spa_t *spa = zio->io_spa;
4111 blkptr_t *bp = zio->io_bp;
4112 uint64_t psize = BP_GET_PSIZE(bp);
4113 uint64_t dsobj = zio->io_bookmark.zb_objset;
4114 dmu_object_type_t ot = BP_GET_TYPE(bp);
4115 void *enc_buf = NULL;
4117 uint8_t salt[ZIO_DATA_SALT_LEN];
4118 uint8_t iv[ZIO_DATA_IV_LEN];
4119 uint8_t mac[ZIO_DATA_MAC_LEN];
4120 boolean_t no_crypt = B_FALSE;
4122 /* the root zio already encrypted the data */
4123 if (zio->io_child_type == ZIO_CHILD_GANG)
4126 /* only ZIL blocks are re-encrypted on rewrite */
4127 if (!IO_IS_ALLOCATING(zio) && ot != DMU_OT_INTENT_LOG)
4130 if (!(zp->zp_encrypt || BP_IS_ENCRYPTED(bp))) {
4131 BP_SET_CRYPT(bp, B_FALSE);
4135 /* if we are doing raw encryption set the provided encryption params */
4136 if (zio->io_flags & ZIO_FLAG_RAW_ENCRYPT) {
4137 ASSERT0(BP_GET_LEVEL(bp));
4138 BP_SET_CRYPT(bp, B_TRUE);
4139 BP_SET_BYTEORDER(bp, zp->zp_byteorder);
4140 if (ot != DMU_OT_OBJSET)
4141 zio_crypt_encode_mac_bp(bp, zp->zp_mac);
4143 /* dnode blocks must be written out in the provided byteorder */
4144 if (zp->zp_byteorder != ZFS_HOST_BYTEORDER &&
4145 ot == DMU_OT_DNODE) {
4146 void *bswap_buf = zio_buf_alloc(psize);
4147 abd_t *babd = abd_get_from_buf(bswap_buf, psize);
4149 ASSERT3U(BP_GET_COMPRESS(bp), ==, ZIO_COMPRESS_OFF);
4150 abd_copy_to_buf(bswap_buf, zio->io_abd, psize);
4151 dmu_ot_byteswap[DMU_OT_BYTESWAP(ot)].ob_func(bswap_buf,
4154 abd_take_ownership_of_buf(babd, B_TRUE);
4155 zio_push_transform(zio, babd, psize, psize, NULL);
4158 if (DMU_OT_IS_ENCRYPTED(ot))
4159 zio_crypt_encode_params_bp(bp, zp->zp_salt, zp->zp_iv);
4163 /* indirect blocks only maintain a cksum of the lower level MACs */
4164 if (BP_GET_LEVEL(bp) > 0) {
4165 BP_SET_CRYPT(bp, B_TRUE);
4166 VERIFY0(zio_crypt_do_indirect_mac_checksum_abd(B_TRUE,
4167 zio->io_orig_abd, BP_GET_LSIZE(bp), BP_SHOULD_BYTESWAP(bp),
4169 zio_crypt_encode_mac_bp(bp, mac);
4174 * Objset blocks are a special case since they have 2 256-bit MACs
4175 * embedded within them.
4177 if (ot == DMU_OT_OBJSET) {
4178 ASSERT0(DMU_OT_IS_ENCRYPTED(ot));
4179 ASSERT3U(BP_GET_COMPRESS(bp), ==, ZIO_COMPRESS_OFF);
4180 BP_SET_CRYPT(bp, B_TRUE);
4181 VERIFY0(spa_do_crypt_objset_mac_abd(B_TRUE, spa, dsobj,
4182 zio->io_abd, psize, BP_SHOULD_BYTESWAP(bp)));
4186 /* unencrypted object types are only authenticated with a MAC */
4187 if (!DMU_OT_IS_ENCRYPTED(ot)) {
4188 BP_SET_CRYPT(bp, B_TRUE);
4189 VERIFY0(spa_do_crypt_mac_abd(B_TRUE, spa, dsobj,
4190 zio->io_abd, psize, mac));
4191 zio_crypt_encode_mac_bp(bp, mac);
4196 * Later passes of sync-to-convergence may decide to rewrite data
4197 * in place to avoid more disk reallocations. This presents a problem
4198 * for encryption because this constitutes rewriting the new data with
4199 * the same encryption key and IV. However, this only applies to blocks
4200 * in the MOS (particularly the spacemaps) and we do not encrypt the
4201 * MOS. We assert that the zio is allocating or an intent log write
4204 ASSERT(IO_IS_ALLOCATING(zio) || ot == DMU_OT_INTENT_LOG);
4205 ASSERT(BP_GET_LEVEL(bp) == 0 || ot == DMU_OT_INTENT_LOG);
4206 ASSERT(spa_feature_is_active(spa, SPA_FEATURE_ENCRYPTION));
4207 ASSERT3U(psize, !=, 0);
4209 enc_buf = zio_buf_alloc(psize);
4210 eabd = abd_get_from_buf(enc_buf, psize);
4211 abd_take_ownership_of_buf(eabd, B_TRUE);
4214 * For an explanation of what encryption parameters are stored
4215 * where, see the block comment in zio_crypt.c.
4217 if (ot == DMU_OT_INTENT_LOG) {
4218 zio_crypt_decode_params_bp(bp, salt, iv);
4220 BP_SET_CRYPT(bp, B_TRUE);
4223 /* Perform the encryption. This should not fail */
4224 VERIFY0(spa_do_crypt_abd(B_TRUE, spa, &zio->io_bookmark,
4225 BP_GET_TYPE(bp), BP_GET_DEDUP(bp), BP_SHOULD_BYTESWAP(bp),
4226 salt, iv, mac, psize, zio->io_abd, eabd, &no_crypt));
4228 /* encode encryption metadata into the bp */
4229 if (ot == DMU_OT_INTENT_LOG) {
4231 * ZIL blocks store the MAC in the embedded checksum, so the
4232 * transform must always be applied.
4234 zio_crypt_encode_mac_zil(enc_buf, mac);
4235 zio_push_transform(zio, eabd, psize, psize, NULL);
4237 BP_SET_CRYPT(bp, B_TRUE);
4238 zio_crypt_encode_params_bp(bp, salt, iv);
4239 zio_crypt_encode_mac_bp(bp, mac);
4242 ASSERT3U(ot, ==, DMU_OT_DNODE);
4245 zio_push_transform(zio, eabd, psize, psize, NULL);
4253 * ==========================================================================
4254 * Generate and verify checksums
4255 * ==========================================================================
4258 zio_checksum_generate(zio_t *zio)
4260 blkptr_t *bp = zio->io_bp;
4261 enum zio_checksum checksum;
4265 * This is zio_write_phys().
4266 * We're either generating a label checksum, or none at all.
4268 checksum = zio->io_prop.zp_checksum;
4270 if (checksum == ZIO_CHECKSUM_OFF)
4273 ASSERT(checksum == ZIO_CHECKSUM_LABEL);
4275 if (BP_IS_GANG(bp) && zio->io_child_type == ZIO_CHILD_GANG) {
4276 ASSERT(!IO_IS_ALLOCATING(zio));
4277 checksum = ZIO_CHECKSUM_GANG_HEADER;
4279 checksum = BP_GET_CHECKSUM(bp);
4283 zio_checksum_compute(zio, checksum, zio->io_abd, zio->io_size);
4289 zio_checksum_verify(zio_t *zio)
4291 zio_bad_cksum_t info;
4292 blkptr_t *bp = zio->io_bp;
4295 ASSERT(zio->io_vd != NULL);
4299 * This is zio_read_phys().
4300 * We're either verifying a label checksum, or nothing at all.
4302 if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF)
4305 ASSERT3U(zio->io_prop.zp_checksum, ==, ZIO_CHECKSUM_LABEL);
4308 if ((error = zio_checksum_error(zio, &info)) != 0) {
4309 zio->io_error = error;
4310 if (error == ECKSUM &&
4311 !(zio->io_flags & ZIO_FLAG_SPECULATIVE)) {
4312 (void) zfs_ereport_start_checksum(zio->io_spa,
4313 zio->io_vd, &zio->io_bookmark, zio,
4314 zio->io_offset, zio->io_size, &info);
4315 mutex_enter(&zio->io_vd->vdev_stat_lock);
4316 zio->io_vd->vdev_stat.vs_checksum_errors++;
4317 mutex_exit(&zio->io_vd->vdev_stat_lock);
4325 * Called by RAID-Z to ensure we don't compute the checksum twice.
4328 zio_checksum_verified(zio_t *zio)
4330 zio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY;
4334 * ==========================================================================
4335 * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other.
4336 * An error of 0 indicates success. ENXIO indicates whole-device failure,
4337 * which may be transient (e.g. unplugged) or permanent. ECKSUM and EIO
4338 * indicate errors that are specific to one I/O, and most likely permanent.
4339 * Any other error is presumed to be worse because we weren't expecting it.
4340 * ==========================================================================
4343 zio_worst_error(int e1, int e2)
4345 static int zio_error_rank[] = { 0, ENXIO, ECKSUM, EIO };
4348 for (r1 = 0; r1 < sizeof (zio_error_rank) / sizeof (int); r1++)
4349 if (e1 == zio_error_rank[r1])
4352 for (r2 = 0; r2 < sizeof (zio_error_rank) / sizeof (int); r2++)
4353 if (e2 == zio_error_rank[r2])
4356 return (r1 > r2 ? e1 : e2);
4360 * ==========================================================================
4362 * ==========================================================================
4365 zio_ready(zio_t *zio)
4367 blkptr_t *bp = zio->io_bp;
4368 zio_t *pio, *pio_next;
4369 zio_link_t *zl = NULL;
4371 if (zio_wait_for_children(zio, ZIO_CHILD_GANG_BIT | ZIO_CHILD_DDT_BIT,
4376 if (zio->io_ready) {
4377 ASSERT(IO_IS_ALLOCATING(zio));
4378 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp) ||
4379 (zio->io_flags & ZIO_FLAG_NOPWRITE));
4380 ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0);
4385 if (bp != NULL && bp != &zio->io_bp_copy)
4386 zio->io_bp_copy = *bp;
4388 if (zio->io_error != 0) {
4389 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
4391 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING) {
4392 ASSERT(IO_IS_ALLOCATING(zio));
4393 ASSERT(zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE);
4394 ASSERT(zio->io_metaslab_class != NULL);
4397 * We were unable to allocate anything, unreserve and
4398 * issue the next I/O to allocate.
4400 metaslab_class_throttle_unreserve(
4401 zio->io_metaslab_class, zio->io_prop.zp_copies,
4402 zio->io_allocator, zio);
4403 zio_allocate_dispatch(zio->io_spa, zio->io_allocator);
4407 mutex_enter(&zio->io_lock);
4408 zio->io_state[ZIO_WAIT_READY] = 1;
4409 pio = zio_walk_parents(zio, &zl);
4410 mutex_exit(&zio->io_lock);
4413 * As we notify zio's parents, new parents could be added.
4414 * New parents go to the head of zio's io_parent_list, however,
4415 * so we will (correctly) not notify them. The remainder of zio's
4416 * io_parent_list, from 'pio_next' onward, cannot change because
4417 * all parents must wait for us to be done before they can be done.
4419 for (; pio != NULL; pio = pio_next) {
4420 pio_next = zio_walk_parents(zio, &zl);
4421 zio_notify_parent(pio, zio, ZIO_WAIT_READY, NULL);
4424 if (zio->io_flags & ZIO_FLAG_NODATA) {
4425 if (BP_IS_GANG(bp)) {
4426 zio->io_flags &= ~ZIO_FLAG_NODATA;
4428 ASSERT((uintptr_t)zio->io_abd < SPA_MAXBLOCKSIZE);
4429 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES;
4433 if (zio_injection_enabled &&
4434 zio->io_spa->spa_syncing_txg == zio->io_txg)
4435 zio_handle_ignored_writes(zio);
4441 * Update the allocation throttle accounting.
4444 zio_dva_throttle_done(zio_t *zio)
4446 zio_t *lio __maybe_unused = zio->io_logical;
4447 zio_t *pio = zio_unique_parent(zio);
4448 vdev_t *vd = zio->io_vd;
4449 int flags = METASLAB_ASYNC_ALLOC;
4451 ASSERT3P(zio->io_bp, !=, NULL);
4452 ASSERT3U(zio->io_type, ==, ZIO_TYPE_WRITE);
4453 ASSERT3U(zio->io_priority, ==, ZIO_PRIORITY_ASYNC_WRITE);
4454 ASSERT3U(zio->io_child_type, ==, ZIO_CHILD_VDEV);
4456 ASSERT3P(vd, ==, vd->vdev_top);
4457 ASSERT(zio_injection_enabled || !(zio->io_flags & ZIO_FLAG_IO_RETRY));
4458 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REPAIR));
4459 ASSERT(zio->io_flags & ZIO_FLAG_IO_ALLOCATING);
4460 ASSERT(!(lio->io_flags & ZIO_FLAG_IO_REWRITE));
4461 ASSERT(!(lio->io_orig_flags & ZIO_FLAG_NODATA));
4464 * Parents of gang children can have two flavors -- ones that
4465 * allocated the gang header (will have ZIO_FLAG_IO_REWRITE set)
4466 * and ones that allocated the constituent blocks. The allocation
4467 * throttle needs to know the allocating parent zio so we must find
4470 if (pio->io_child_type == ZIO_CHILD_GANG) {
4472 * If our parent is a rewrite gang child then our grandparent
4473 * would have been the one that performed the allocation.
4475 if (pio->io_flags & ZIO_FLAG_IO_REWRITE)
4476 pio = zio_unique_parent(pio);
4477 flags |= METASLAB_GANG_CHILD;
4480 ASSERT(IO_IS_ALLOCATING(pio));
4481 ASSERT3P(zio, !=, zio->io_logical);
4482 ASSERT(zio->io_logical != NULL);
4483 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REPAIR));
4484 ASSERT0(zio->io_flags & ZIO_FLAG_NOPWRITE);
4485 ASSERT(zio->io_metaslab_class != NULL);
4487 mutex_enter(&pio->io_lock);
4488 metaslab_group_alloc_decrement(zio->io_spa, vd->vdev_id, pio, flags,
4489 pio->io_allocator, B_TRUE);
4490 mutex_exit(&pio->io_lock);
4492 metaslab_class_throttle_unreserve(zio->io_metaslab_class, 1,
4493 pio->io_allocator, pio);
4496 * Call into the pipeline to see if there is more work that
4497 * needs to be done. If there is work to be done it will be
4498 * dispatched to another taskq thread.
4500 zio_allocate_dispatch(zio->io_spa, pio->io_allocator);
4504 zio_done(zio_t *zio)
4507 * Always attempt to keep stack usage minimal here since
4508 * we can be called recursively up to 19 levels deep.
4510 const uint64_t psize = zio->io_size;
4511 zio_t *pio, *pio_next;
4512 zio_link_t *zl = NULL;
4515 * If our children haven't all completed,
4516 * wait for them and then repeat this pipeline stage.
4518 if (zio_wait_for_children(zio, ZIO_CHILD_ALL_BITS, ZIO_WAIT_DONE)) {
4523 * If the allocation throttle is enabled, then update the accounting.
4524 * We only track child I/Os that are part of an allocating async
4525 * write. We must do this since the allocation is performed
4526 * by the logical I/O but the actual write is done by child I/Os.
4528 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING &&
4529 zio->io_child_type == ZIO_CHILD_VDEV) {
4530 ASSERT(zio->io_metaslab_class != NULL);
4531 ASSERT(zio->io_metaslab_class->mc_alloc_throttle_enabled);
4532 zio_dva_throttle_done(zio);
4536 * If the allocation throttle is enabled, verify that
4537 * we have decremented the refcounts for every I/O that was throttled.
4539 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING) {
4540 ASSERT(zio->io_type == ZIO_TYPE_WRITE);
4541 ASSERT(zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE);
4542 ASSERT(zio->io_bp != NULL);
4544 metaslab_group_alloc_verify(zio->io_spa, zio->io_bp, zio,
4546 VERIFY(zfs_refcount_not_held(&zio->io_metaslab_class->
4547 mc_allocator[zio->io_allocator].mca_alloc_slots, zio));
4551 for (int c = 0; c < ZIO_CHILD_TYPES; c++)
4552 for (int w = 0; w < ZIO_WAIT_TYPES; w++)
4553 ASSERT(zio->io_children[c][w] == 0);
4555 if (zio->io_bp != NULL && !BP_IS_EMBEDDED(zio->io_bp)) {
4556 ASSERT(zio->io_bp->blk_pad[0] == 0);
4557 ASSERT(zio->io_bp->blk_pad[1] == 0);
4558 ASSERT(bcmp(zio->io_bp, &zio->io_bp_copy,
4559 sizeof (blkptr_t)) == 0 ||
4560 (zio->io_bp == zio_unique_parent(zio)->io_bp));
4561 if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(zio->io_bp) &&
4562 zio->io_bp_override == NULL &&
4563 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) {
4564 ASSERT3U(zio->io_prop.zp_copies, <=,
4565 BP_GET_NDVAS(zio->io_bp));
4566 ASSERT(BP_COUNT_GANG(zio->io_bp) == 0 ||
4567 (BP_COUNT_GANG(zio->io_bp) ==
4568 BP_GET_NDVAS(zio->io_bp)));
4570 if (zio->io_flags & ZIO_FLAG_NOPWRITE)
4571 VERIFY(BP_EQUAL(zio->io_bp, &zio->io_bp_orig));
4575 * If there were child vdev/gang/ddt errors, they apply to us now.
4577 zio_inherit_child_errors(zio, ZIO_CHILD_VDEV);
4578 zio_inherit_child_errors(zio, ZIO_CHILD_GANG);
4579 zio_inherit_child_errors(zio, ZIO_CHILD_DDT);
4582 * If the I/O on the transformed data was successful, generate any
4583 * checksum reports now while we still have the transformed data.
4585 if (zio->io_error == 0) {
4586 while (zio->io_cksum_report != NULL) {
4587 zio_cksum_report_t *zcr = zio->io_cksum_report;
4588 uint64_t align = zcr->zcr_align;
4589 uint64_t asize = P2ROUNDUP(psize, align);
4590 abd_t *adata = zio->io_abd;
4592 if (adata != NULL && asize != psize) {
4593 adata = abd_alloc(asize, B_TRUE);
4594 abd_copy(adata, zio->io_abd, psize);
4595 abd_zero_off(adata, psize, asize - psize);
4598 zio->io_cksum_report = zcr->zcr_next;
4599 zcr->zcr_next = NULL;
4600 zcr->zcr_finish(zcr, adata);
4601 zfs_ereport_free_checksum(zcr);
4603 if (adata != NULL && asize != psize)
4608 zio_pop_transforms(zio); /* note: may set zio->io_error */
4610 vdev_stat_update(zio, psize);
4613 * If this I/O is attached to a particular vdev is slow, exceeding
4614 * 30 seconds to complete, post an error described the I/O delay.
4615 * We ignore these errors if the device is currently unavailable.
4617 if (zio->io_delay >= MSEC2NSEC(zio_slow_io_ms)) {
4618 if (zio->io_vd != NULL && !vdev_is_dead(zio->io_vd)) {
4620 * We want to only increment our slow IO counters if
4621 * the IO is valid (i.e. not if the drive is removed).
4623 * zfs_ereport_post() will also do these checks, but
4624 * it can also ratelimit and have other failures, so we
4625 * need to increment the slow_io counters independent
4628 if (zfs_ereport_is_valid(FM_EREPORT_ZFS_DELAY,
4629 zio->io_spa, zio->io_vd, zio)) {
4630 mutex_enter(&zio->io_vd->vdev_stat_lock);
4631 zio->io_vd->vdev_stat.vs_slow_ios++;
4632 mutex_exit(&zio->io_vd->vdev_stat_lock);
4634 (void) zfs_ereport_post(FM_EREPORT_ZFS_DELAY,
4635 zio->io_spa, zio->io_vd, &zio->io_bookmark,
4641 if (zio->io_error) {
4643 * If this I/O is attached to a particular vdev,
4644 * generate an error message describing the I/O failure
4645 * at the block level. We ignore these errors if the
4646 * device is currently unavailable.
4648 if (zio->io_error != ECKSUM && zio->io_vd != NULL &&
4649 !vdev_is_dead(zio->io_vd)) {
4650 int ret = zfs_ereport_post(FM_EREPORT_ZFS_IO,
4651 zio->io_spa, zio->io_vd, &zio->io_bookmark, zio, 0);
4652 if (ret != EALREADY) {
4653 mutex_enter(&zio->io_vd->vdev_stat_lock);
4654 if (zio->io_type == ZIO_TYPE_READ)
4655 zio->io_vd->vdev_stat.vs_read_errors++;
4656 else if (zio->io_type == ZIO_TYPE_WRITE)
4657 zio->io_vd->vdev_stat.vs_write_errors++;
4658 mutex_exit(&zio->io_vd->vdev_stat_lock);
4662 if ((zio->io_error == EIO || !(zio->io_flags &
4663 (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) &&
4664 zio == zio->io_logical) {
4666 * For logical I/O requests, tell the SPA to log the
4667 * error and generate a logical data ereport.
4669 spa_log_error(zio->io_spa, &zio->io_bookmark);
4670 (void) zfs_ereport_post(FM_EREPORT_ZFS_DATA,
4671 zio->io_spa, NULL, &zio->io_bookmark, zio, 0);
4675 if (zio->io_error && zio == zio->io_logical) {
4677 * Determine whether zio should be reexecuted. This will
4678 * propagate all the way to the root via zio_notify_parent().
4680 ASSERT(zio->io_vd == NULL && zio->io_bp != NULL);
4681 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
4683 if (IO_IS_ALLOCATING(zio) &&
4684 !(zio->io_flags & ZIO_FLAG_CANFAIL)) {
4685 if (zio->io_error != ENOSPC)
4686 zio->io_reexecute |= ZIO_REEXECUTE_NOW;
4688 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND;
4691 if ((zio->io_type == ZIO_TYPE_READ ||
4692 zio->io_type == ZIO_TYPE_FREE) &&
4693 !(zio->io_flags & ZIO_FLAG_SCAN_THREAD) &&
4694 zio->io_error == ENXIO &&
4695 spa_load_state(zio->io_spa) == SPA_LOAD_NONE &&
4696 spa_get_failmode(zio->io_spa) != ZIO_FAILURE_MODE_CONTINUE)
4697 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND;
4699 if (!(zio->io_flags & ZIO_FLAG_CANFAIL) && !zio->io_reexecute)
4700 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND;
4703 * Here is a possibly good place to attempt to do
4704 * either combinatorial reconstruction or error correction
4705 * based on checksums. It also might be a good place
4706 * to send out preliminary ereports before we suspend
4712 * If there were logical child errors, they apply to us now.
4713 * We defer this until now to avoid conflating logical child
4714 * errors with errors that happened to the zio itself when
4715 * updating vdev stats and reporting FMA events above.
4717 zio_inherit_child_errors(zio, ZIO_CHILD_LOGICAL);
4719 if ((zio->io_error || zio->io_reexecute) &&
4720 IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio &&
4721 !(zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE)))
4722 zio_dva_unallocate(zio, zio->io_gang_tree, zio->io_bp);
4724 zio_gang_tree_free(&zio->io_gang_tree);
4727 * Godfather I/Os should never suspend.
4729 if ((zio->io_flags & ZIO_FLAG_GODFATHER) &&
4730 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND))
4731 zio->io_reexecute &= ~ZIO_REEXECUTE_SUSPEND;
4733 if (zio->io_reexecute) {
4735 * This is a logical I/O that wants to reexecute.
4737 * Reexecute is top-down. When an i/o fails, if it's not
4738 * the root, it simply notifies its parent and sticks around.
4739 * The parent, seeing that it still has children in zio_done(),
4740 * does the same. This percolates all the way up to the root.
4741 * The root i/o will reexecute or suspend the entire tree.
4743 * This approach ensures that zio_reexecute() honors
4744 * all the original i/o dependency relationships, e.g.
4745 * parents not executing until children are ready.
4747 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
4749 zio->io_gang_leader = NULL;
4751 mutex_enter(&zio->io_lock);
4752 zio->io_state[ZIO_WAIT_DONE] = 1;
4753 mutex_exit(&zio->io_lock);
4756 * "The Godfather" I/O monitors its children but is
4757 * not a true parent to them. It will track them through
4758 * the pipeline but severs its ties whenever they get into
4759 * trouble (e.g. suspended). This allows "The Godfather"
4760 * I/O to return status without blocking.
4763 for (pio = zio_walk_parents(zio, &zl); pio != NULL;
4765 zio_link_t *remove_zl = zl;
4766 pio_next = zio_walk_parents(zio, &zl);
4768 if ((pio->io_flags & ZIO_FLAG_GODFATHER) &&
4769 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) {
4770 zio_remove_child(pio, zio, remove_zl);
4772 * This is a rare code path, so we don't
4773 * bother with "next_to_execute".
4775 zio_notify_parent(pio, zio, ZIO_WAIT_DONE,
4780 if ((pio = zio_unique_parent(zio)) != NULL) {
4782 * We're not a root i/o, so there's nothing to do
4783 * but notify our parent. Don't propagate errors
4784 * upward since we haven't permanently failed yet.
4786 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER));
4787 zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE;
4789 * This is a rare code path, so we don't bother with
4790 * "next_to_execute".
4792 zio_notify_parent(pio, zio, ZIO_WAIT_DONE, NULL);
4793 } else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) {
4795 * We'd fail again if we reexecuted now, so suspend
4796 * until conditions improve (e.g. device comes online).
4798 zio_suspend(zio->io_spa, zio, ZIO_SUSPEND_IOERR);
4801 * Reexecution is potentially a huge amount of work.
4802 * Hand it off to the otherwise-unused claim taskq.
4804 ASSERT(taskq_empty_ent(&zio->io_tqent));
4805 spa_taskq_dispatch_ent(zio->io_spa,
4806 ZIO_TYPE_CLAIM, ZIO_TASKQ_ISSUE,
4807 zio_reexecute, zio, 0, &zio->io_tqent);
4812 ASSERT(zio->io_child_count == 0);
4813 ASSERT(zio->io_reexecute == 0);
4814 ASSERT(zio->io_error == 0 || (zio->io_flags & ZIO_FLAG_CANFAIL));
4817 * Report any checksum errors, since the I/O is complete.
4819 while (zio->io_cksum_report != NULL) {
4820 zio_cksum_report_t *zcr = zio->io_cksum_report;
4821 zio->io_cksum_report = zcr->zcr_next;
4822 zcr->zcr_next = NULL;
4823 zcr->zcr_finish(zcr, NULL);
4824 zfs_ereport_free_checksum(zcr);
4827 if (zio->io_flags & ZIO_FLAG_FASTWRITE && zio->io_bp &&
4828 !BP_IS_HOLE(zio->io_bp) && !BP_IS_EMBEDDED(zio->io_bp) &&
4829 !(zio->io_flags & ZIO_FLAG_NOPWRITE)) {
4830 metaslab_fastwrite_unmark(zio->io_spa, zio->io_bp);
4834 * It is the responsibility of the done callback to ensure that this
4835 * particular zio is no longer discoverable for adoption, and as
4836 * such, cannot acquire any new parents.
4841 mutex_enter(&zio->io_lock);
4842 zio->io_state[ZIO_WAIT_DONE] = 1;
4843 mutex_exit(&zio->io_lock);
4846 * We are done executing this zio. We may want to execute a parent
4847 * next. See the comment in zio_notify_parent().
4849 zio_t *next_to_execute = NULL;
4851 for (pio = zio_walk_parents(zio, &zl); pio != NULL; pio = pio_next) {
4852 zio_link_t *remove_zl = zl;
4853 pio_next = zio_walk_parents(zio, &zl);
4854 zio_remove_child(pio, zio, remove_zl);
4855 zio_notify_parent(pio, zio, ZIO_WAIT_DONE, &next_to_execute);
4858 if (zio->io_waiter != NULL) {
4859 mutex_enter(&zio->io_lock);
4860 zio->io_executor = NULL;
4861 cv_broadcast(&zio->io_cv);
4862 mutex_exit(&zio->io_lock);
4867 return (next_to_execute);
4871 * ==========================================================================
4872 * I/O pipeline definition
4873 * ==========================================================================
4875 static zio_pipe_stage_t *zio_pipeline[] = {
4883 zio_checksum_generate,
4899 zio_checksum_verify,
4907 * Compare two zbookmark_phys_t's to see which we would reach first in a
4908 * pre-order traversal of the object tree.
4910 * This is simple in every case aside from the meta-dnode object. For all other
4911 * objects, we traverse them in order (object 1 before object 2, and so on).
4912 * However, all of these objects are traversed while traversing object 0, since
4913 * the data it points to is the list of objects. Thus, we need to convert to a
4914 * canonical representation so we can compare meta-dnode bookmarks to
4915 * non-meta-dnode bookmarks.
4917 * We do this by calculating "equivalents" for each field of the zbookmark.
4918 * zbookmarks outside of the meta-dnode use their own object and level, and
4919 * calculate the level 0 equivalent (the first L0 blkid that is contained in the
4920 * blocks this bookmark refers to) by multiplying their blkid by their span
4921 * (the number of L0 blocks contained within one block at their level).
4922 * zbookmarks inside the meta-dnode calculate their object equivalent
4923 * (which is L0equiv * dnodes per data block), use 0 for their L0equiv, and use
4924 * level + 1<<31 (any value larger than a level could ever be) for their level.
4925 * This causes them to always compare before a bookmark in their object
4926 * equivalent, compare appropriately to bookmarks in other objects, and to
4927 * compare appropriately to other bookmarks in the meta-dnode.
4930 zbookmark_compare(uint16_t dbss1, uint8_t ibs1, uint16_t dbss2, uint8_t ibs2,
4931 const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2)
4934 * These variables represent the "equivalent" values for the zbookmark,
4935 * after converting zbookmarks inside the meta dnode to their
4936 * normal-object equivalents.
4938 uint64_t zb1obj, zb2obj;
4939 uint64_t zb1L0, zb2L0;
4940 uint64_t zb1level, zb2level;
4942 if (zb1->zb_object == zb2->zb_object &&
4943 zb1->zb_level == zb2->zb_level &&
4944 zb1->zb_blkid == zb2->zb_blkid)
4947 IMPLY(zb1->zb_level > 0, ibs1 >= SPA_MINBLOCKSHIFT);
4948 IMPLY(zb2->zb_level > 0, ibs2 >= SPA_MINBLOCKSHIFT);
4951 * BP_SPANB calculates the span in blocks.
4953 zb1L0 = (zb1->zb_blkid) * BP_SPANB(ibs1, zb1->zb_level);
4954 zb2L0 = (zb2->zb_blkid) * BP_SPANB(ibs2, zb2->zb_level);
4956 if (zb1->zb_object == DMU_META_DNODE_OBJECT) {
4957 zb1obj = zb1L0 * (dbss1 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT));
4959 zb1level = zb1->zb_level + COMPARE_META_LEVEL;
4961 zb1obj = zb1->zb_object;
4962 zb1level = zb1->zb_level;
4965 if (zb2->zb_object == DMU_META_DNODE_OBJECT) {
4966 zb2obj = zb2L0 * (dbss2 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT));
4968 zb2level = zb2->zb_level + COMPARE_META_LEVEL;
4970 zb2obj = zb2->zb_object;
4971 zb2level = zb2->zb_level;
4974 /* Now that we have a canonical representation, do the comparison. */
4975 if (zb1obj != zb2obj)
4976 return (zb1obj < zb2obj ? -1 : 1);
4977 else if (zb1L0 != zb2L0)
4978 return (zb1L0 < zb2L0 ? -1 : 1);
4979 else if (zb1level != zb2level)
4980 return (zb1level > zb2level ? -1 : 1);
4982 * This can (theoretically) happen if the bookmarks have the same object
4983 * and level, but different blkids, if the block sizes are not the same.
4984 * There is presently no way to change the indirect block sizes
4990 * This function checks the following: given that last_block is the place that
4991 * our traversal stopped last time, does that guarantee that we've visited
4992 * every node under subtree_root? Therefore, we can't just use the raw output
4993 * of zbookmark_compare. We have to pass in a modified version of
4994 * subtree_root; by incrementing the block id, and then checking whether
4995 * last_block is before or equal to that, we can tell whether or not having
4996 * visited last_block implies that all of subtree_root's children have been
5000 zbookmark_subtree_completed(const dnode_phys_t *dnp,
5001 const zbookmark_phys_t *subtree_root, const zbookmark_phys_t *last_block)
5003 zbookmark_phys_t mod_zb = *subtree_root;
5005 ASSERT(last_block->zb_level == 0);
5007 /* The objset_phys_t isn't before anything. */
5012 * We pass in 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT) for the
5013 * data block size in sectors, because that variable is only used if
5014 * the bookmark refers to a block in the meta-dnode. Since we don't
5015 * know without examining it what object it refers to, and there's no
5016 * harm in passing in this value in other cases, we always pass it in.
5018 * We pass in 0 for the indirect block size shift because zb2 must be
5019 * level 0. The indirect block size is only used to calculate the span
5020 * of the bookmark, but since the bookmark must be level 0, the span is
5021 * always 1, so the math works out.
5023 * If you make changes to how the zbookmark_compare code works, be sure
5024 * to make sure that this code still works afterwards.
5026 return (zbookmark_compare(dnp->dn_datablkszsec, dnp->dn_indblkshift,
5027 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT), 0, &mod_zb,
5031 EXPORT_SYMBOL(zio_type_name);
5032 EXPORT_SYMBOL(zio_buf_alloc);
5033 EXPORT_SYMBOL(zio_data_buf_alloc);
5034 EXPORT_SYMBOL(zio_buf_free);
5035 EXPORT_SYMBOL(zio_data_buf_free);
5038 ZFS_MODULE_PARAM(zfs_zio, zio_, slow_io_ms, INT, ZMOD_RW,
5039 "Max I/O completion time (milliseconds) before marking it as slow");
5041 ZFS_MODULE_PARAM(zfs_zio, zio_, requeue_io_start_cut_in_line, INT, ZMOD_RW,
5042 "Prioritize requeued I/O");
5044 ZFS_MODULE_PARAM(zfs, zfs_, sync_pass_deferred_free, INT, ZMOD_RW,
5045 "Defer frees starting in this pass");
5047 ZFS_MODULE_PARAM(zfs, zfs_, sync_pass_dont_compress, INT, ZMOD_RW,
5048 "Don't compress starting in this pass");
5050 ZFS_MODULE_PARAM(zfs, zfs_, sync_pass_rewrite, INT, ZMOD_RW,
5051 "Rewrite new bps starting in this pass");
5053 ZFS_MODULE_PARAM(zfs_zio, zio_, dva_throttle_enabled, INT, ZMOD_RW,
5054 "Throttle block allocations in the ZIO pipeline");
5056 ZFS_MODULE_PARAM(zfs_zio, zio_, deadman_log_all, INT, ZMOD_RW,
5057 "Log all slow ZIOs, not just those with vdevs");