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 *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 int zio_deadman_log_all = B_FALSE;
72 * ==========================================================================
74 * ==========================================================================
76 kmem_cache_t *zio_cache;
77 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 uint64_t zio_buf_cache_allocs[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT];
82 uint64_t zio_buf_cache_frees[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT];
85 /* Mark IOs as "slow" if they take longer than 30 seconds */
86 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 int zfs_sync_pass_dont_compress = 8; /* don't compress starting in this pass */
119 int zfs_sync_pass_rewrite = 2; /* rewrite new bps starting in this pass */
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 int zio_requeue_io_start_cut_in_line = 1;
135 int zio_buf_debug_limit = 16384;
137 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)
372 abd_free((abd_t *)abd);
376 * ==========================================================================
377 * Push and pop I/O transform buffers
378 * ==========================================================================
381 zio_push_transform(zio_t *zio, abd_t *data, uint64_t size, uint64_t bufsize,
382 zio_transform_func_t *transform)
384 zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP);
386 zt->zt_orig_abd = zio->io_abd;
387 zt->zt_orig_size = zio->io_size;
388 zt->zt_bufsize = bufsize;
389 zt->zt_transform = transform;
391 zt->zt_next = zio->io_transform_stack;
392 zio->io_transform_stack = zt;
399 zio_pop_transforms(zio_t *zio)
403 while ((zt = zio->io_transform_stack) != NULL) {
404 if (zt->zt_transform != NULL)
405 zt->zt_transform(zio,
406 zt->zt_orig_abd, zt->zt_orig_size);
408 if (zt->zt_bufsize != 0)
409 abd_free(zio->io_abd);
411 zio->io_abd = zt->zt_orig_abd;
412 zio->io_size = zt->zt_orig_size;
413 zio->io_transform_stack = zt->zt_next;
415 kmem_free(zt, sizeof (zio_transform_t));
420 * ==========================================================================
421 * I/O transform callbacks for subblocks, decompression, and decryption
422 * ==========================================================================
425 zio_subblock(zio_t *zio, abd_t *data, uint64_t size)
427 ASSERT(zio->io_size > size);
429 if (zio->io_type == ZIO_TYPE_READ)
430 abd_copy(data, zio->io_abd, size);
434 zio_decompress(zio_t *zio, abd_t *data, uint64_t size)
436 if (zio->io_error == 0) {
437 void *tmp = abd_borrow_buf(data, size);
438 int ret = zio_decompress_data(BP_GET_COMPRESS(zio->io_bp),
439 zio->io_abd, tmp, zio->io_size, size,
440 &zio->io_prop.zp_complevel);
441 abd_return_buf_copy(data, tmp, size);
443 if (zio_injection_enabled && ret == 0)
444 ret = zio_handle_fault_injection(zio, EINVAL);
447 zio->io_error = SET_ERROR(EIO);
452 zio_decrypt(zio_t *zio, abd_t *data, uint64_t size)
456 blkptr_t *bp = zio->io_bp;
457 spa_t *spa = zio->io_spa;
458 uint64_t dsobj = zio->io_bookmark.zb_objset;
459 uint64_t lsize = BP_GET_LSIZE(bp);
460 dmu_object_type_t ot = BP_GET_TYPE(bp);
461 uint8_t salt[ZIO_DATA_SALT_LEN];
462 uint8_t iv[ZIO_DATA_IV_LEN];
463 uint8_t mac[ZIO_DATA_MAC_LEN];
464 boolean_t no_crypt = B_FALSE;
466 ASSERT(BP_USES_CRYPT(bp));
467 ASSERT3U(size, !=, 0);
469 if (zio->io_error != 0)
473 * Verify the cksum of MACs stored in an indirect bp. It will always
474 * be possible to verify this since it does not require an encryption
477 if (BP_HAS_INDIRECT_MAC_CKSUM(bp)) {
478 zio_crypt_decode_mac_bp(bp, mac);
480 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF) {
482 * We haven't decompressed the data yet, but
483 * zio_crypt_do_indirect_mac_checksum() requires
484 * decompressed data to be able to parse out the MACs
485 * from the indirect block. We decompress it now and
486 * throw away the result after we are finished.
488 tmp = zio_buf_alloc(lsize);
489 ret = zio_decompress_data(BP_GET_COMPRESS(bp),
490 zio->io_abd, tmp, zio->io_size, lsize,
491 &zio->io_prop.zp_complevel);
493 ret = SET_ERROR(EIO);
496 ret = zio_crypt_do_indirect_mac_checksum(B_FALSE,
497 tmp, lsize, BP_SHOULD_BYTESWAP(bp), mac);
498 zio_buf_free(tmp, lsize);
500 ret = zio_crypt_do_indirect_mac_checksum_abd(B_FALSE,
501 zio->io_abd, size, BP_SHOULD_BYTESWAP(bp), mac);
503 abd_copy(data, zio->io_abd, size);
505 if (zio_injection_enabled && ot != DMU_OT_DNODE && ret == 0) {
506 ret = zio_handle_decrypt_injection(spa,
507 &zio->io_bookmark, ot, ECKSUM);
516 * If this is an authenticated block, just check the MAC. It would be
517 * nice to separate this out into its own flag, but for the moment
518 * enum zio_flag is out of bits.
520 if (BP_IS_AUTHENTICATED(bp)) {
521 if (ot == DMU_OT_OBJSET) {
522 ret = spa_do_crypt_objset_mac_abd(B_FALSE, spa,
523 dsobj, zio->io_abd, size, BP_SHOULD_BYTESWAP(bp));
525 zio_crypt_decode_mac_bp(bp, mac);
526 ret = spa_do_crypt_mac_abd(B_FALSE, spa, dsobj,
527 zio->io_abd, size, mac);
528 if (zio_injection_enabled && ret == 0) {
529 ret = zio_handle_decrypt_injection(spa,
530 &zio->io_bookmark, ot, ECKSUM);
533 abd_copy(data, zio->io_abd, size);
541 zio_crypt_decode_params_bp(bp, salt, iv);
543 if (ot == DMU_OT_INTENT_LOG) {
544 tmp = abd_borrow_buf_copy(zio->io_abd, sizeof (zil_chain_t));
545 zio_crypt_decode_mac_zil(tmp, mac);
546 abd_return_buf(zio->io_abd, tmp, sizeof (zil_chain_t));
548 zio_crypt_decode_mac_bp(bp, mac);
551 ret = spa_do_crypt_abd(B_FALSE, spa, &zio->io_bookmark, BP_GET_TYPE(bp),
552 BP_GET_DEDUP(bp), BP_SHOULD_BYTESWAP(bp), salt, iv, mac, size, data,
553 zio->io_abd, &no_crypt);
555 abd_copy(data, zio->io_abd, size);
563 /* assert that the key was found unless this was speculative */
564 ASSERT(ret != EACCES || (zio->io_flags & ZIO_FLAG_SPECULATIVE));
567 * If there was a decryption / authentication error return EIO as
568 * the io_error. If this was not a speculative zio, create an ereport.
571 zio->io_error = SET_ERROR(EIO);
572 if ((zio->io_flags & ZIO_FLAG_SPECULATIVE) == 0) {
573 spa_log_error(spa, &zio->io_bookmark);
574 (void) zfs_ereport_post(FM_EREPORT_ZFS_AUTHENTICATION,
575 spa, NULL, &zio->io_bookmark, zio, 0);
583 * ==========================================================================
584 * I/O parent/child relationships and pipeline interlocks
585 * ==========================================================================
588 zio_walk_parents(zio_t *cio, zio_link_t **zl)
590 list_t *pl = &cio->io_parent_list;
592 *zl = (*zl == NULL) ? list_head(pl) : list_next(pl, *zl);
596 ASSERT((*zl)->zl_child == cio);
597 return ((*zl)->zl_parent);
601 zio_walk_children(zio_t *pio, zio_link_t **zl)
603 list_t *cl = &pio->io_child_list;
605 ASSERT(MUTEX_HELD(&pio->io_lock));
607 *zl = (*zl == NULL) ? list_head(cl) : list_next(cl, *zl);
611 ASSERT((*zl)->zl_parent == pio);
612 return ((*zl)->zl_child);
616 zio_unique_parent(zio_t *cio)
618 zio_link_t *zl = NULL;
619 zio_t *pio = zio_walk_parents(cio, &zl);
621 VERIFY3P(zio_walk_parents(cio, &zl), ==, NULL);
626 zio_add_child(zio_t *pio, zio_t *cio)
628 zio_link_t *zl = kmem_cache_alloc(zio_link_cache, KM_SLEEP);
631 * Logical I/Os can have logical, gang, or vdev children.
632 * Gang I/Os can have gang or vdev children.
633 * Vdev I/Os can only have vdev children.
634 * The following ASSERT captures all of these constraints.
636 ASSERT3S(cio->io_child_type, <=, pio->io_child_type);
641 mutex_enter(&pio->io_lock);
642 mutex_enter(&cio->io_lock);
644 ASSERT(pio->io_state[ZIO_WAIT_DONE] == 0);
646 for (int w = 0; w < ZIO_WAIT_TYPES; w++)
647 pio->io_children[cio->io_child_type][w] += !cio->io_state[w];
649 list_insert_head(&pio->io_child_list, zl);
650 list_insert_head(&cio->io_parent_list, zl);
652 pio->io_child_count++;
653 cio->io_parent_count++;
655 mutex_exit(&cio->io_lock);
656 mutex_exit(&pio->io_lock);
660 zio_remove_child(zio_t *pio, zio_t *cio, zio_link_t *zl)
662 ASSERT(zl->zl_parent == pio);
663 ASSERT(zl->zl_child == cio);
665 mutex_enter(&pio->io_lock);
666 mutex_enter(&cio->io_lock);
668 list_remove(&pio->io_child_list, zl);
669 list_remove(&cio->io_parent_list, zl);
671 pio->io_child_count--;
672 cio->io_parent_count--;
674 mutex_exit(&cio->io_lock);
675 mutex_exit(&pio->io_lock);
676 kmem_cache_free(zio_link_cache, zl);
680 zio_wait_for_children(zio_t *zio, uint8_t childbits, enum zio_wait_type wait)
682 boolean_t waiting = B_FALSE;
684 mutex_enter(&zio->io_lock);
685 ASSERT(zio->io_stall == NULL);
686 for (int c = 0; c < ZIO_CHILD_TYPES; c++) {
687 if (!(ZIO_CHILD_BIT_IS_SET(childbits, c)))
690 uint64_t *countp = &zio->io_children[c][wait];
693 ASSERT3U(zio->io_stage, !=, ZIO_STAGE_OPEN);
694 zio->io_stall = countp;
699 mutex_exit(&zio->io_lock);
703 __attribute__((always_inline))
705 zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait,
706 zio_t **next_to_executep)
708 uint64_t *countp = &pio->io_children[zio->io_child_type][wait];
709 int *errorp = &pio->io_child_error[zio->io_child_type];
711 mutex_enter(&pio->io_lock);
712 if (zio->io_error && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE))
713 *errorp = zio_worst_error(*errorp, zio->io_error);
714 pio->io_reexecute |= zio->io_reexecute;
715 ASSERT3U(*countp, >, 0);
719 if (*countp == 0 && pio->io_stall == countp) {
720 zio_taskq_type_t type =
721 pio->io_stage < ZIO_STAGE_VDEV_IO_START ? ZIO_TASKQ_ISSUE :
723 pio->io_stall = NULL;
724 mutex_exit(&pio->io_lock);
727 * If we can tell the caller to execute this parent next, do
728 * so. Otherwise dispatch the parent zio as its own task.
730 * Having the caller execute the parent when possible reduces
731 * locking on the zio taskq's, reduces context switch
732 * overhead, and has no recursion penalty. Note that one
733 * read from disk typically causes at least 3 zio's: a
734 * zio_null(), the logical zio_read(), and then a physical
735 * zio. When the physical ZIO completes, we are able to call
736 * zio_done() on all 3 of these zio's from one invocation of
737 * zio_execute() by returning the parent back to
738 * zio_execute(). Since the parent isn't executed until this
739 * thread returns back to zio_execute(), the caller should do
742 * In other cases, dispatching the parent prevents
743 * overflowing the stack when we have deeply nested
744 * parent-child relationships, as we do with the "mega zio"
745 * of writes for spa_sync(), and the chain of ZIL blocks.
747 if (next_to_executep != NULL && *next_to_executep == NULL) {
748 *next_to_executep = pio;
750 zio_taskq_dispatch(pio, type, B_FALSE);
753 mutex_exit(&pio->io_lock);
758 zio_inherit_child_errors(zio_t *zio, enum zio_child c)
760 if (zio->io_child_error[c] != 0 && zio->io_error == 0)
761 zio->io_error = zio->io_child_error[c];
765 zio_bookmark_compare(const void *x1, const void *x2)
767 const zio_t *z1 = x1;
768 const zio_t *z2 = x2;
770 if (z1->io_bookmark.zb_objset < z2->io_bookmark.zb_objset)
772 if (z1->io_bookmark.zb_objset > z2->io_bookmark.zb_objset)
775 if (z1->io_bookmark.zb_object < z2->io_bookmark.zb_object)
777 if (z1->io_bookmark.zb_object > z2->io_bookmark.zb_object)
780 if (z1->io_bookmark.zb_level < z2->io_bookmark.zb_level)
782 if (z1->io_bookmark.zb_level > z2->io_bookmark.zb_level)
785 if (z1->io_bookmark.zb_blkid < z2->io_bookmark.zb_blkid)
787 if (z1->io_bookmark.zb_blkid > z2->io_bookmark.zb_blkid)
799 * ==========================================================================
800 * Create the various types of I/O (read, write, free, etc)
801 * ==========================================================================
804 zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp,
805 abd_t *data, uint64_t lsize, uint64_t psize, zio_done_func_t *done,
806 void *private, zio_type_t type, zio_priority_t priority,
807 enum zio_flag flags, vdev_t *vd, uint64_t offset,
808 const zbookmark_phys_t *zb, enum zio_stage stage,
809 enum zio_stage pipeline)
813 IMPLY(type != ZIO_TYPE_TRIM, psize <= SPA_MAXBLOCKSIZE);
814 ASSERT(P2PHASE(psize, SPA_MINBLOCKSIZE) == 0);
815 ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0);
817 ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER));
818 ASSERT(!bp || !(flags & ZIO_FLAG_CONFIG_WRITER));
819 ASSERT(vd || stage == ZIO_STAGE_OPEN);
821 IMPLY(lsize != psize, (flags & ZIO_FLAG_RAW_COMPRESS) != 0);
823 zio = kmem_cache_alloc(zio_cache, KM_SLEEP);
824 bzero(zio, sizeof (zio_t));
826 mutex_init(&zio->io_lock, NULL, MUTEX_NOLOCKDEP, NULL);
827 cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL);
829 list_create(&zio->io_parent_list, sizeof (zio_link_t),
830 offsetof(zio_link_t, zl_parent_node));
831 list_create(&zio->io_child_list, sizeof (zio_link_t),
832 offsetof(zio_link_t, zl_child_node));
833 metaslab_trace_init(&zio->io_alloc_list);
836 zio->io_child_type = ZIO_CHILD_VDEV;
837 else if (flags & ZIO_FLAG_GANG_CHILD)
838 zio->io_child_type = ZIO_CHILD_GANG;
839 else if (flags & ZIO_FLAG_DDT_CHILD)
840 zio->io_child_type = ZIO_CHILD_DDT;
842 zio->io_child_type = ZIO_CHILD_LOGICAL;
845 zio->io_bp = (blkptr_t *)bp;
846 zio->io_bp_copy = *bp;
847 zio->io_bp_orig = *bp;
848 if (type != ZIO_TYPE_WRITE ||
849 zio->io_child_type == ZIO_CHILD_DDT)
850 zio->io_bp = &zio->io_bp_copy; /* so caller can free */
851 if (zio->io_child_type == ZIO_CHILD_LOGICAL)
852 zio->io_logical = zio;
853 if (zio->io_child_type > ZIO_CHILD_GANG && BP_IS_GANG(bp))
854 pipeline |= ZIO_GANG_STAGES;
860 zio->io_private = private;
862 zio->io_priority = priority;
864 zio->io_offset = offset;
865 zio->io_orig_abd = zio->io_abd = data;
866 zio->io_orig_size = zio->io_size = psize;
867 zio->io_lsize = lsize;
868 zio->io_orig_flags = zio->io_flags = flags;
869 zio->io_orig_stage = zio->io_stage = stage;
870 zio->io_orig_pipeline = zio->io_pipeline = pipeline;
871 zio->io_pipeline_trace = ZIO_STAGE_OPEN;
873 zio->io_state[ZIO_WAIT_READY] = (stage >= ZIO_STAGE_READY);
874 zio->io_state[ZIO_WAIT_DONE] = (stage >= ZIO_STAGE_DONE);
877 zio->io_bookmark = *zb;
880 zio->io_metaslab_class = pio->io_metaslab_class;
881 if (zio->io_logical == NULL)
882 zio->io_logical = pio->io_logical;
883 if (zio->io_child_type == ZIO_CHILD_GANG)
884 zio->io_gang_leader = pio->io_gang_leader;
885 zio_add_child(pio, zio);
888 taskq_init_ent(&zio->io_tqent);
894 zio_destroy(zio_t *zio)
896 metaslab_trace_fini(&zio->io_alloc_list);
897 list_destroy(&zio->io_parent_list);
898 list_destroy(&zio->io_child_list);
899 mutex_destroy(&zio->io_lock);
900 cv_destroy(&zio->io_cv);
901 kmem_cache_free(zio_cache, zio);
905 zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, zio_done_func_t *done,
906 void *private, enum zio_flag flags)
910 zio = zio_create(pio, spa, 0, NULL, NULL, 0, 0, done, private,
911 ZIO_TYPE_NULL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL,
912 ZIO_STAGE_OPEN, ZIO_INTERLOCK_PIPELINE);
918 zio_root(spa_t *spa, zio_done_func_t *done, void *private, enum zio_flag flags)
920 return (zio_null(NULL, spa, NULL, done, private, flags));
924 zfs_blkptr_verify_log(spa_t *spa, const blkptr_t *bp,
925 enum blk_verify_flag blk_verify, const char *fmt, ...)
931 (void) vsnprintf(buf, sizeof (buf), fmt, adx);
934 switch (blk_verify) {
935 case BLK_VERIFY_HALT:
936 dprintf_bp(bp, "blkptr at %p dprintf_bp():", bp);
937 zfs_panic_recover("%s: %s", spa_name(spa), buf);
940 zfs_dbgmsg("%s: %s", spa_name(spa), buf);
942 case BLK_VERIFY_ONLY:
950 * Verify the block pointer fields contain reasonable values. This means
951 * it only contains known object types, checksum/compression identifiers,
952 * block sizes within the maximum allowed limits, valid DVAs, etc.
954 * If everything checks out B_TRUE is returned. The zfs_blkptr_verify
955 * argument controls the behavior when an invalid field is detected.
957 * Modes for zfs_blkptr_verify:
958 * 1) BLK_VERIFY_ONLY (evaluate the block)
959 * 2) BLK_VERIFY_LOG (evaluate the block and log problems)
960 * 3) BLK_VERIFY_HALT (call zfs_panic_recover on error)
963 zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp, boolean_t config_held,
964 enum blk_verify_flag blk_verify)
968 if (!DMU_OT_IS_VALID(BP_GET_TYPE(bp))) {
969 errors += zfs_blkptr_verify_log(spa, bp, blk_verify,
970 "blkptr at %p has invalid TYPE %llu",
971 bp, (longlong_t)BP_GET_TYPE(bp));
973 if (BP_GET_CHECKSUM(bp) >= ZIO_CHECKSUM_FUNCTIONS ||
974 BP_GET_CHECKSUM(bp) <= ZIO_CHECKSUM_ON) {
975 errors += zfs_blkptr_verify_log(spa, bp, blk_verify,
976 "blkptr at %p has invalid CHECKSUM %llu",
977 bp, (longlong_t)BP_GET_CHECKSUM(bp));
979 if (BP_GET_COMPRESS(bp) >= ZIO_COMPRESS_FUNCTIONS ||
980 BP_GET_COMPRESS(bp) <= ZIO_COMPRESS_ON) {
981 errors += zfs_blkptr_verify_log(spa, bp, blk_verify,
982 "blkptr at %p has invalid COMPRESS %llu",
983 bp, (longlong_t)BP_GET_COMPRESS(bp));
985 if (BP_GET_LSIZE(bp) > SPA_MAXBLOCKSIZE) {
986 errors += zfs_blkptr_verify_log(spa, bp, blk_verify,
987 "blkptr at %p has invalid LSIZE %llu",
988 bp, (longlong_t)BP_GET_LSIZE(bp));
990 if (BP_GET_PSIZE(bp) > SPA_MAXBLOCKSIZE) {
991 errors += zfs_blkptr_verify_log(spa, bp, blk_verify,
992 "blkptr at %p has invalid PSIZE %llu",
993 bp, (longlong_t)BP_GET_PSIZE(bp));
996 if (BP_IS_EMBEDDED(bp)) {
997 if (BPE_GET_ETYPE(bp) >= NUM_BP_EMBEDDED_TYPES) {
998 errors += zfs_blkptr_verify_log(spa, bp, blk_verify,
999 "blkptr at %p has invalid ETYPE %llu",
1000 bp, (longlong_t)BPE_GET_ETYPE(bp));
1005 * Do not verify individual DVAs if the config is not trusted. This
1006 * will be done once the zio is executed in vdev_mirror_map_alloc.
1008 if (!spa->spa_trust_config)
1009 return (errors == 0);
1012 spa_config_enter(spa, SCL_VDEV, bp, RW_READER);
1014 ASSERT(spa_config_held(spa, SCL_VDEV, RW_WRITER));
1016 * Pool-specific checks.
1018 * Note: it would be nice to verify that the blk_birth and
1019 * BP_PHYSICAL_BIRTH() are not too large. However, spa_freeze()
1020 * allows the birth time of log blocks (and dmu_sync()-ed blocks
1021 * that are in the log) to be arbitrarily large.
1023 for (int i = 0; i < BP_GET_NDVAS(bp); i++) {
1024 const dva_t *dva = &bp->blk_dva[i];
1025 uint64_t vdevid = DVA_GET_VDEV(dva);
1027 if (vdevid >= spa->spa_root_vdev->vdev_children) {
1028 errors += zfs_blkptr_verify_log(spa, bp, blk_verify,
1029 "blkptr at %p DVA %u has invalid VDEV %llu",
1030 bp, i, (longlong_t)vdevid);
1033 vdev_t *vd = spa->spa_root_vdev->vdev_child[vdevid];
1035 errors += zfs_blkptr_verify_log(spa, bp, blk_verify,
1036 "blkptr at %p DVA %u has invalid VDEV %llu",
1037 bp, i, (longlong_t)vdevid);
1040 if (vd->vdev_ops == &vdev_hole_ops) {
1041 errors += zfs_blkptr_verify_log(spa, bp, blk_verify,
1042 "blkptr at %p DVA %u has hole VDEV %llu",
1043 bp, i, (longlong_t)vdevid);
1046 if (vd->vdev_ops == &vdev_missing_ops) {
1048 * "missing" vdevs are valid during import, but we
1049 * don't have their detailed info (e.g. asize), so
1050 * we can't perform any more checks on them.
1054 uint64_t offset = DVA_GET_OFFSET(dva);
1055 uint64_t asize = DVA_GET_ASIZE(dva);
1056 if (DVA_GET_GANG(dva))
1057 asize = vdev_gang_header_asize(vd);
1058 if (offset + asize > vd->vdev_asize) {
1059 errors += zfs_blkptr_verify_log(spa, bp, blk_verify,
1060 "blkptr at %p DVA %u has invalid OFFSET %llu",
1061 bp, i, (longlong_t)offset);
1065 dprintf_bp(bp, "blkptr at %p dprintf_bp():", bp);
1067 spa_config_exit(spa, SCL_VDEV, bp);
1069 return (errors == 0);
1073 zfs_dva_valid(spa_t *spa, const dva_t *dva, const blkptr_t *bp)
1075 uint64_t vdevid = DVA_GET_VDEV(dva);
1077 if (vdevid >= spa->spa_root_vdev->vdev_children)
1080 vdev_t *vd = spa->spa_root_vdev->vdev_child[vdevid];
1084 if (vd->vdev_ops == &vdev_hole_ops)
1087 if (vd->vdev_ops == &vdev_missing_ops) {
1091 uint64_t offset = DVA_GET_OFFSET(dva);
1092 uint64_t asize = DVA_GET_ASIZE(dva);
1094 if (DVA_GET_GANG(dva))
1095 asize = vdev_gang_header_asize(vd);
1096 if (offset + asize > vd->vdev_asize)
1103 zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
1104 abd_t *data, uint64_t size, zio_done_func_t *done, void *private,
1105 zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb)
1109 zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp,
1110 data, size, size, done, private,
1111 ZIO_TYPE_READ, priority, flags, NULL, 0, zb,
1112 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ?
1113 ZIO_DDT_CHILD_READ_PIPELINE : ZIO_READ_PIPELINE);
1119 zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
1120 abd_t *data, uint64_t lsize, uint64_t psize, const zio_prop_t *zp,
1121 zio_done_func_t *ready, zio_done_func_t *children_ready,
1122 zio_done_func_t *physdone, zio_done_func_t *done,
1123 void *private, zio_priority_t priority, enum zio_flag flags,
1124 const zbookmark_phys_t *zb)
1128 ASSERT(zp->zp_checksum >= ZIO_CHECKSUM_OFF &&
1129 zp->zp_checksum < ZIO_CHECKSUM_FUNCTIONS &&
1130 zp->zp_compress >= ZIO_COMPRESS_OFF &&
1131 zp->zp_compress < ZIO_COMPRESS_FUNCTIONS &&
1132 DMU_OT_IS_VALID(zp->zp_type) &&
1133 zp->zp_level < 32 &&
1134 zp->zp_copies > 0 &&
1135 zp->zp_copies <= spa_max_replication(spa));
1137 zio = zio_create(pio, spa, txg, bp, data, lsize, psize, done, private,
1138 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb,
1139 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ?
1140 ZIO_DDT_CHILD_WRITE_PIPELINE : ZIO_WRITE_PIPELINE);
1142 zio->io_ready = ready;
1143 zio->io_children_ready = children_ready;
1144 zio->io_physdone = physdone;
1148 * Data can be NULL if we are going to call zio_write_override() to
1149 * provide the already-allocated BP. But we may need the data to
1150 * verify a dedup hit (if requested). In this case, don't try to
1151 * dedup (just take the already-allocated BP verbatim). Encrypted
1152 * dedup blocks need data as well so we also disable dedup in this
1156 (zio->io_prop.zp_dedup_verify || zio->io_prop.zp_encrypt)) {
1157 zio->io_prop.zp_dedup = zio->io_prop.zp_dedup_verify = B_FALSE;
1164 zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, abd_t *data,
1165 uint64_t size, zio_done_func_t *done, void *private,
1166 zio_priority_t priority, enum zio_flag flags, zbookmark_phys_t *zb)
1170 zio = zio_create(pio, spa, txg, bp, data, size, size, done, private,
1171 ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_IO_REWRITE, NULL, 0, zb,
1172 ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE);
1178 zio_write_override(zio_t *zio, blkptr_t *bp, int copies, boolean_t nopwrite)
1180 ASSERT(zio->io_type == ZIO_TYPE_WRITE);
1181 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1182 ASSERT(zio->io_stage == ZIO_STAGE_OPEN);
1183 ASSERT(zio->io_txg == spa_syncing_txg(zio->io_spa));
1186 * We must reset the io_prop to match the values that existed
1187 * when the bp was first written by dmu_sync() keeping in mind
1188 * that nopwrite and dedup are mutually exclusive.
1190 zio->io_prop.zp_dedup = nopwrite ? B_FALSE : zio->io_prop.zp_dedup;
1191 zio->io_prop.zp_nopwrite = nopwrite;
1192 zio->io_prop.zp_copies = copies;
1193 zio->io_bp_override = bp;
1197 zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp)
1200 (void) zfs_blkptr_verify(spa, bp, B_FALSE, BLK_VERIFY_HALT);
1203 * The check for EMBEDDED is a performance optimization. We
1204 * process the free here (by ignoring it) rather than
1205 * putting it on the list and then processing it in zio_free_sync().
1207 if (BP_IS_EMBEDDED(bp))
1209 metaslab_check_free(spa, bp);
1212 * Frees that are for the currently-syncing txg, are not going to be
1213 * deferred, and which will not need to do a read (i.e. not GANG or
1214 * DEDUP), can be processed immediately. Otherwise, put them on the
1215 * in-memory list for later processing.
1217 * Note that we only defer frees after zfs_sync_pass_deferred_free
1218 * when the log space map feature is disabled. [see relevant comment
1219 * in spa_sync_iterate_to_convergence()]
1221 if (BP_IS_GANG(bp) ||
1223 txg != spa->spa_syncing_txg ||
1224 (spa_sync_pass(spa) >= zfs_sync_pass_deferred_free &&
1225 !spa_feature_is_active(spa, SPA_FEATURE_LOG_SPACEMAP))) {
1226 bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp);
1228 VERIFY3P(zio_free_sync(NULL, spa, txg, bp, 0), ==, NULL);
1233 * To improve performance, this function may return NULL if we were able
1234 * to do the free immediately. This avoids the cost of creating a zio
1235 * (and linking it to the parent, etc).
1238 zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp,
1239 enum zio_flag flags)
1241 ASSERT(!BP_IS_HOLE(bp));
1242 ASSERT(spa_syncing_txg(spa) == txg);
1244 if (BP_IS_EMBEDDED(bp))
1247 metaslab_check_free(spa, bp);
1249 dsl_scan_freed(spa, bp);
1251 if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp)) {
1253 * GANG and DEDUP blocks can induce a read (for the gang block
1254 * header, or the DDT), so issue them asynchronously so that
1255 * this thread is not tied up.
1257 enum zio_stage stage =
1258 ZIO_FREE_PIPELINE | ZIO_STAGE_ISSUE_ASYNC;
1260 return (zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp),
1261 BP_GET_PSIZE(bp), NULL, NULL,
1262 ZIO_TYPE_FREE, ZIO_PRIORITY_NOW,
1263 flags, NULL, 0, NULL, ZIO_STAGE_OPEN, stage));
1265 metaslab_free(spa, bp, txg, B_FALSE);
1271 zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp,
1272 zio_done_func_t *done, void *private, enum zio_flag flags)
1276 (void) zfs_blkptr_verify(spa, bp, flags & ZIO_FLAG_CONFIG_WRITER,
1279 if (BP_IS_EMBEDDED(bp))
1280 return (zio_null(pio, spa, NULL, NULL, NULL, 0));
1283 * A claim is an allocation of a specific block. Claims are needed
1284 * to support immediate writes in the intent log. The issue is that
1285 * immediate writes contain committed data, but in a txg that was
1286 * *not* committed. Upon opening the pool after an unclean shutdown,
1287 * the intent log claims all blocks that contain immediate write data
1288 * so that the SPA knows they're in use.
1290 * All claims *must* be resolved in the first txg -- before the SPA
1291 * starts allocating blocks -- so that nothing is allocated twice.
1292 * If txg == 0 we just verify that the block is claimable.
1294 ASSERT3U(spa->spa_uberblock.ub_rootbp.blk_birth, <,
1295 spa_min_claim_txg(spa));
1296 ASSERT(txg == spa_min_claim_txg(spa) || txg == 0);
1297 ASSERT(!BP_GET_DEDUP(bp) || !spa_writeable(spa)); /* zdb(8) */
1299 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp),
1300 BP_GET_PSIZE(bp), done, private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW,
1301 flags, NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE);
1302 ASSERT0(zio->io_queued_timestamp);
1308 zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
1309 zio_done_func_t *done, void *private, enum zio_flag flags)
1314 if (vd->vdev_children == 0) {
1315 zio = zio_create(pio, spa, 0, NULL, NULL, 0, 0, done, private,
1316 ZIO_TYPE_IOCTL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL,
1317 ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE);
1321 zio = zio_null(pio, spa, NULL, NULL, NULL, flags);
1323 for (c = 0; c < vd->vdev_children; c++)
1324 zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd,
1325 done, private, flags));
1332 zio_trim(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size,
1333 zio_done_func_t *done, void *private, zio_priority_t priority,
1334 enum zio_flag flags, enum trim_flag trim_flags)
1338 ASSERT0(vd->vdev_children);
1339 ASSERT0(P2PHASE(offset, 1ULL << vd->vdev_ashift));
1340 ASSERT0(P2PHASE(size, 1ULL << vd->vdev_ashift));
1341 ASSERT3U(size, !=, 0);
1343 zio = zio_create(pio, vd->vdev_spa, 0, NULL, NULL, size, size, done,
1344 private, ZIO_TYPE_TRIM, priority, flags | ZIO_FLAG_PHYSICAL,
1345 vd, offset, NULL, ZIO_STAGE_OPEN, ZIO_TRIM_PIPELINE);
1346 zio->io_trim_flags = trim_flags;
1352 zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size,
1353 abd_t *data, int checksum, zio_done_func_t *done, void *private,
1354 zio_priority_t priority, enum zio_flag flags, boolean_t labels)
1358 ASSERT(vd->vdev_children == 0);
1359 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE ||
1360 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE);
1361 ASSERT3U(offset + size, <=, vd->vdev_psize);
1363 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, size, done,
1364 private, ZIO_TYPE_READ, priority, flags | ZIO_FLAG_PHYSICAL, vd,
1365 offset, NULL, ZIO_STAGE_OPEN, ZIO_READ_PHYS_PIPELINE);
1367 zio->io_prop.zp_checksum = checksum;
1373 zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size,
1374 abd_t *data, int checksum, zio_done_func_t *done, void *private,
1375 zio_priority_t priority, enum zio_flag flags, boolean_t labels)
1379 ASSERT(vd->vdev_children == 0);
1380 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE ||
1381 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE);
1382 ASSERT3U(offset + size, <=, vd->vdev_psize);
1384 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, size, done,
1385 private, ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_PHYSICAL, vd,
1386 offset, NULL, ZIO_STAGE_OPEN, ZIO_WRITE_PHYS_PIPELINE);
1388 zio->io_prop.zp_checksum = checksum;
1390 if (zio_checksum_table[checksum].ci_flags & ZCHECKSUM_FLAG_EMBEDDED) {
1392 * zec checksums are necessarily destructive -- they modify
1393 * the end of the write buffer to hold the verifier/checksum.
1394 * Therefore, we must make a local copy in case the data is
1395 * being written to multiple places in parallel.
1397 abd_t *wbuf = abd_alloc_sametype(data, size);
1398 abd_copy(wbuf, data, size);
1400 zio_push_transform(zio, wbuf, size, size, NULL);
1407 * Create a child I/O to do some work for us.
1410 zio_vdev_child_io(zio_t *pio, blkptr_t *bp, vdev_t *vd, uint64_t offset,
1411 abd_t *data, uint64_t size, int type, zio_priority_t priority,
1412 enum zio_flag flags, zio_done_func_t *done, void *private)
1414 enum zio_stage pipeline = ZIO_VDEV_CHILD_PIPELINE;
1418 * vdev child I/Os do not propagate their error to the parent.
1419 * Therefore, for correct operation the caller *must* check for
1420 * and handle the error in the child i/o's done callback.
1421 * The only exceptions are i/os that we don't care about
1422 * (OPTIONAL or REPAIR).
1424 ASSERT((flags & ZIO_FLAG_OPTIONAL) || (flags & ZIO_FLAG_IO_REPAIR) ||
1427 if (type == ZIO_TYPE_READ && bp != NULL) {
1429 * If we have the bp, then the child should perform the
1430 * checksum and the parent need not. This pushes error
1431 * detection as close to the leaves as possible and
1432 * eliminates redundant checksums in the interior nodes.
1434 pipeline |= ZIO_STAGE_CHECKSUM_VERIFY;
1435 pio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY;
1438 if (vd->vdev_ops->vdev_op_leaf) {
1439 ASSERT0(vd->vdev_children);
1440 offset += VDEV_LABEL_START_SIZE;
1443 flags |= ZIO_VDEV_CHILD_FLAGS(pio);
1446 * If we've decided to do a repair, the write is not speculative --
1447 * even if the original read was.
1449 if (flags & ZIO_FLAG_IO_REPAIR)
1450 flags &= ~ZIO_FLAG_SPECULATIVE;
1453 * If we're creating a child I/O that is not associated with a
1454 * top-level vdev, then the child zio is not an allocating I/O.
1455 * If this is a retried I/O then we ignore it since we will
1456 * have already processed the original allocating I/O.
1458 if (flags & ZIO_FLAG_IO_ALLOCATING &&
1459 (vd != vd->vdev_top || (flags & ZIO_FLAG_IO_RETRY))) {
1460 ASSERT(pio->io_metaslab_class != NULL);
1461 ASSERT(pio->io_metaslab_class->mc_alloc_throttle_enabled);
1462 ASSERT(type == ZIO_TYPE_WRITE);
1463 ASSERT(priority == ZIO_PRIORITY_ASYNC_WRITE);
1464 ASSERT(!(flags & ZIO_FLAG_IO_REPAIR));
1465 ASSERT(!(pio->io_flags & ZIO_FLAG_IO_REWRITE) ||
1466 pio->io_child_type == ZIO_CHILD_GANG);
1468 flags &= ~ZIO_FLAG_IO_ALLOCATING;
1472 zio = zio_create(pio, pio->io_spa, pio->io_txg, bp, data, size, size,
1473 done, private, type, priority, flags, vd, offset, &pio->io_bookmark,
1474 ZIO_STAGE_VDEV_IO_START >> 1, pipeline);
1475 ASSERT3U(zio->io_child_type, ==, ZIO_CHILD_VDEV);
1477 zio->io_physdone = pio->io_physdone;
1478 if (vd->vdev_ops->vdev_op_leaf && zio->io_logical != NULL)
1479 zio->io_logical->io_phys_children++;
1485 zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, abd_t *data, uint64_t size,
1486 zio_type_t type, zio_priority_t priority, enum zio_flag flags,
1487 zio_done_func_t *done, void *private)
1491 ASSERT(vd->vdev_ops->vdev_op_leaf);
1493 zio = zio_create(NULL, vd->vdev_spa, 0, NULL,
1494 data, size, size, done, private, type, priority,
1495 flags | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY | ZIO_FLAG_DELEGATED,
1497 ZIO_STAGE_VDEV_IO_START >> 1, ZIO_VDEV_CHILD_PIPELINE);
1503 zio_flush(zio_t *zio, vdev_t *vd)
1505 zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE,
1507 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY));
1511 zio_shrink(zio_t *zio, uint64_t size)
1513 ASSERT3P(zio->io_executor, ==, NULL);
1514 ASSERT3U(zio->io_orig_size, ==, zio->io_size);
1515 ASSERT3U(size, <=, zio->io_size);
1518 * We don't shrink for raidz because of problems with the
1519 * reconstruction when reading back less than the block size.
1520 * Note, BP_IS_RAIDZ() assumes no compression.
1522 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF);
1523 if (!BP_IS_RAIDZ(zio->io_bp)) {
1524 /* we are not doing a raw write */
1525 ASSERT3U(zio->io_size, ==, zio->io_lsize);
1526 zio->io_orig_size = zio->io_size = zio->io_lsize = size;
1531 * ==========================================================================
1532 * Prepare to read and write logical blocks
1533 * ==========================================================================
1537 zio_read_bp_init(zio_t *zio)
1539 blkptr_t *bp = zio->io_bp;
1541 BP_IS_EMBEDDED(bp) ? BPE_GET_PSIZE(bp) : BP_GET_PSIZE(bp);
1543 ASSERT3P(zio->io_bp, ==, &zio->io_bp_copy);
1545 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF &&
1546 zio->io_child_type == ZIO_CHILD_LOGICAL &&
1547 !(zio->io_flags & ZIO_FLAG_RAW_COMPRESS)) {
1548 zio_push_transform(zio, abd_alloc_sametype(zio->io_abd, psize),
1549 psize, psize, zio_decompress);
1552 if (((BP_IS_PROTECTED(bp) && !(zio->io_flags & ZIO_FLAG_RAW_ENCRYPT)) ||
1553 BP_HAS_INDIRECT_MAC_CKSUM(bp)) &&
1554 zio->io_child_type == ZIO_CHILD_LOGICAL) {
1555 zio_push_transform(zio, abd_alloc_sametype(zio->io_abd, psize),
1556 psize, psize, zio_decrypt);
1559 if (BP_IS_EMBEDDED(bp) && BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA) {
1560 int psize = BPE_GET_PSIZE(bp);
1561 void *data = abd_borrow_buf(zio->io_abd, psize);
1563 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
1564 decode_embedded_bp_compressed(bp, data);
1565 abd_return_buf_copy(zio->io_abd, data, psize);
1567 ASSERT(!BP_IS_EMBEDDED(bp));
1568 ASSERT3P(zio->io_bp, ==, &zio->io_bp_copy);
1571 if (!DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) && BP_GET_LEVEL(bp) == 0)
1572 zio->io_flags |= ZIO_FLAG_DONT_CACHE;
1574 if (BP_GET_TYPE(bp) == DMU_OT_DDT_ZAP)
1575 zio->io_flags |= ZIO_FLAG_DONT_CACHE;
1577 if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL)
1578 zio->io_pipeline = ZIO_DDT_READ_PIPELINE;
1584 zio_write_bp_init(zio_t *zio)
1586 if (!IO_IS_ALLOCATING(zio))
1589 ASSERT(zio->io_child_type != ZIO_CHILD_DDT);
1591 if (zio->io_bp_override) {
1592 blkptr_t *bp = zio->io_bp;
1593 zio_prop_t *zp = &zio->io_prop;
1595 ASSERT(bp->blk_birth != zio->io_txg);
1596 ASSERT(BP_GET_DEDUP(zio->io_bp_override) == 0);
1598 *bp = *zio->io_bp_override;
1599 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
1601 if (BP_IS_EMBEDDED(bp))
1605 * If we've been overridden and nopwrite is set then
1606 * set the flag accordingly to indicate that a nopwrite
1607 * has already occurred.
1609 if (!BP_IS_HOLE(bp) && zp->zp_nopwrite) {
1610 ASSERT(!zp->zp_dedup);
1611 ASSERT3U(BP_GET_CHECKSUM(bp), ==, zp->zp_checksum);
1612 zio->io_flags |= ZIO_FLAG_NOPWRITE;
1616 ASSERT(!zp->zp_nopwrite);
1618 if (BP_IS_HOLE(bp) || !zp->zp_dedup)
1621 ASSERT((zio_checksum_table[zp->zp_checksum].ci_flags &
1622 ZCHECKSUM_FLAG_DEDUP) || zp->zp_dedup_verify);
1624 if (BP_GET_CHECKSUM(bp) == zp->zp_checksum &&
1626 BP_SET_DEDUP(bp, 1);
1627 zio->io_pipeline |= ZIO_STAGE_DDT_WRITE;
1632 * We were unable to handle this as an override bp, treat
1633 * it as a regular write I/O.
1635 zio->io_bp_override = NULL;
1636 *bp = zio->io_bp_orig;
1637 zio->io_pipeline = zio->io_orig_pipeline;
1644 zio_write_compress(zio_t *zio)
1646 spa_t *spa = zio->io_spa;
1647 zio_prop_t *zp = &zio->io_prop;
1648 enum zio_compress compress = zp->zp_compress;
1649 blkptr_t *bp = zio->io_bp;
1650 uint64_t lsize = zio->io_lsize;
1651 uint64_t psize = zio->io_size;
1655 * If our children haven't all reached the ready stage,
1656 * wait for them and then repeat this pipeline stage.
1658 if (zio_wait_for_children(zio, ZIO_CHILD_LOGICAL_BIT |
1659 ZIO_CHILD_GANG_BIT, ZIO_WAIT_READY)) {
1663 if (!IO_IS_ALLOCATING(zio))
1666 if (zio->io_children_ready != NULL) {
1668 * Now that all our children are ready, run the callback
1669 * associated with this zio in case it wants to modify the
1670 * data to be written.
1672 ASSERT3U(zp->zp_level, >, 0);
1673 zio->io_children_ready(zio);
1676 ASSERT(zio->io_child_type != ZIO_CHILD_DDT);
1677 ASSERT(zio->io_bp_override == NULL);
1679 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg) {
1681 * We're rewriting an existing block, which means we're
1682 * working on behalf of spa_sync(). For spa_sync() to
1683 * converge, it must eventually be the case that we don't
1684 * have to allocate new blocks. But compression changes
1685 * the blocksize, which forces a reallocate, and makes
1686 * convergence take longer. Therefore, after the first
1687 * few passes, stop compressing to ensure convergence.
1689 pass = spa_sync_pass(spa);
1691 ASSERT(zio->io_txg == spa_syncing_txg(spa));
1692 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1693 ASSERT(!BP_GET_DEDUP(bp));
1695 if (pass >= zfs_sync_pass_dont_compress)
1696 compress = ZIO_COMPRESS_OFF;
1698 /* Make sure someone doesn't change their mind on overwrites */
1699 ASSERT(BP_IS_EMBEDDED(bp) || MIN(zp->zp_copies + BP_IS_GANG(bp),
1700 spa_max_replication(spa)) == BP_GET_NDVAS(bp));
1703 /* If it's a compressed write that is not raw, compress the buffer. */
1704 if (compress != ZIO_COMPRESS_OFF &&
1705 !(zio->io_flags & ZIO_FLAG_RAW_COMPRESS)) {
1706 void *cbuf = zio_buf_alloc(lsize);
1707 psize = zio_compress_data(compress, zio->io_abd, cbuf, lsize,
1709 if (psize == 0 || psize >= lsize) {
1710 compress = ZIO_COMPRESS_OFF;
1711 zio_buf_free(cbuf, lsize);
1712 } else if (!zp->zp_dedup && !zp->zp_encrypt &&
1713 psize <= BPE_PAYLOAD_SIZE &&
1714 zp->zp_level == 0 && !DMU_OT_HAS_FILL(zp->zp_type) &&
1715 spa_feature_is_enabled(spa, SPA_FEATURE_EMBEDDED_DATA)) {
1716 encode_embedded_bp_compressed(bp,
1717 cbuf, compress, lsize, psize);
1718 BPE_SET_ETYPE(bp, BP_EMBEDDED_TYPE_DATA);
1719 BP_SET_TYPE(bp, zio->io_prop.zp_type);
1720 BP_SET_LEVEL(bp, zio->io_prop.zp_level);
1721 zio_buf_free(cbuf, lsize);
1722 bp->blk_birth = zio->io_txg;
1723 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
1724 ASSERT(spa_feature_is_active(spa,
1725 SPA_FEATURE_EMBEDDED_DATA));
1729 * Round compressed size up to the minimum allocation
1730 * size of the smallest-ashift device, and zero the
1731 * tail. This ensures that the compressed size of the
1732 * BP (and thus compressratio property) are correct,
1733 * in that we charge for the padding used to fill out
1736 ASSERT3U(spa->spa_min_alloc, >=, SPA_MINBLOCKSHIFT);
1737 size_t rounded = (size_t)roundup(psize,
1738 spa->spa_min_alloc);
1739 if (rounded >= lsize) {
1740 compress = ZIO_COMPRESS_OFF;
1741 zio_buf_free(cbuf, lsize);
1744 abd_t *cdata = abd_get_from_buf(cbuf, lsize);
1745 abd_take_ownership_of_buf(cdata, B_TRUE);
1746 abd_zero_off(cdata, psize, rounded - psize);
1748 zio_push_transform(zio, cdata,
1749 psize, lsize, NULL);
1754 * We were unable to handle this as an override bp, treat
1755 * it as a regular write I/O.
1757 zio->io_bp_override = NULL;
1758 *bp = zio->io_bp_orig;
1759 zio->io_pipeline = zio->io_orig_pipeline;
1761 } else if ((zio->io_flags & ZIO_FLAG_RAW_ENCRYPT) != 0 &&
1762 zp->zp_type == DMU_OT_DNODE) {
1764 * The DMU actually relies on the zio layer's compression
1765 * to free metadnode blocks that have had all contained
1766 * dnodes freed. As a result, even when doing a raw
1767 * receive, we must check whether the block can be compressed
1770 psize = zio_compress_data(ZIO_COMPRESS_EMPTY,
1771 zio->io_abd, NULL, lsize, zp->zp_complevel);
1772 if (psize == 0 || psize >= lsize)
1773 compress = ZIO_COMPRESS_OFF;
1774 } else if (zio->io_flags & ZIO_FLAG_RAW_COMPRESS) {
1775 size_t rounded = MIN((size_t)roundup(psize,
1776 spa->spa_min_alloc), lsize);
1778 if (rounded != psize) {
1779 abd_t *cdata = abd_alloc_linear(rounded, B_TRUE);
1780 abd_zero_off(cdata, psize, rounded - psize);
1781 abd_copy_off(cdata, zio->io_abd, 0, 0, psize);
1783 zio_push_transform(zio, cdata,
1784 psize, rounded, NULL);
1787 ASSERT3U(psize, !=, 0);
1791 * The final pass of spa_sync() must be all rewrites, but the first
1792 * few passes offer a trade-off: allocating blocks defers convergence,
1793 * but newly allocated blocks are sequential, so they can be written
1794 * to disk faster. Therefore, we allow the first few passes of
1795 * spa_sync() to allocate new blocks, but force rewrites after that.
1796 * There should only be a handful of blocks after pass 1 in any case.
1798 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg &&
1799 BP_GET_PSIZE(bp) == psize &&
1800 pass >= zfs_sync_pass_rewrite) {
1801 VERIFY3U(psize, !=, 0);
1802 enum zio_stage gang_stages = zio->io_pipeline & ZIO_GANG_STAGES;
1804 zio->io_pipeline = ZIO_REWRITE_PIPELINE | gang_stages;
1805 zio->io_flags |= ZIO_FLAG_IO_REWRITE;
1808 zio->io_pipeline = ZIO_WRITE_PIPELINE;
1812 if (zio->io_bp_orig.blk_birth != 0 &&
1813 spa_feature_is_active(spa, SPA_FEATURE_HOLE_BIRTH)) {
1814 BP_SET_LSIZE(bp, lsize);
1815 BP_SET_TYPE(bp, zp->zp_type);
1816 BP_SET_LEVEL(bp, zp->zp_level);
1817 BP_SET_BIRTH(bp, zio->io_txg, 0);
1819 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
1821 ASSERT(zp->zp_checksum != ZIO_CHECKSUM_GANG_HEADER);
1822 BP_SET_LSIZE(bp, lsize);
1823 BP_SET_TYPE(bp, zp->zp_type);
1824 BP_SET_LEVEL(bp, zp->zp_level);
1825 BP_SET_PSIZE(bp, psize);
1826 BP_SET_COMPRESS(bp, compress);
1827 BP_SET_CHECKSUM(bp, zp->zp_checksum);
1828 BP_SET_DEDUP(bp, zp->zp_dedup);
1829 BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER);
1831 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1832 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE));
1833 ASSERT(!zp->zp_encrypt ||
1834 DMU_OT_IS_ENCRYPTED(zp->zp_type));
1835 zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE;
1837 if (zp->zp_nopwrite) {
1838 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1839 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE));
1840 zio->io_pipeline |= ZIO_STAGE_NOP_WRITE;
1847 zio_free_bp_init(zio_t *zio)
1849 blkptr_t *bp = zio->io_bp;
1851 if (zio->io_child_type == ZIO_CHILD_LOGICAL) {
1852 if (BP_GET_DEDUP(bp))
1853 zio->io_pipeline = ZIO_DDT_FREE_PIPELINE;
1856 ASSERT3P(zio->io_bp, ==, &zio->io_bp_copy);
1862 * ==========================================================================
1863 * Execute the I/O pipeline
1864 * ==========================================================================
1868 zio_taskq_dispatch(zio_t *zio, zio_taskq_type_t q, boolean_t cutinline)
1870 spa_t *spa = zio->io_spa;
1871 zio_type_t t = zio->io_type;
1872 int flags = (cutinline ? TQ_FRONT : 0);
1875 * If we're a config writer or a probe, the normal issue and
1876 * interrupt threads may all be blocked waiting for the config lock.
1877 * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL.
1879 if (zio->io_flags & (ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_PROBE))
1883 * A similar issue exists for the L2ARC write thread until L2ARC 2.0.
1885 if (t == ZIO_TYPE_WRITE && zio->io_vd && zio->io_vd->vdev_aux)
1889 * If this is a high priority I/O, then use the high priority taskq if
1892 if ((zio->io_priority == ZIO_PRIORITY_NOW ||
1893 zio->io_priority == ZIO_PRIORITY_SYNC_WRITE) &&
1894 spa->spa_zio_taskq[t][q + 1].stqs_count != 0)
1897 ASSERT3U(q, <, ZIO_TASKQ_TYPES);
1900 * NB: We are assuming that the zio can only be dispatched
1901 * to a single taskq at a time. It would be a grievous error
1902 * to dispatch the zio to another taskq at the same time.
1904 ASSERT(taskq_empty_ent(&zio->io_tqent));
1905 spa_taskq_dispatch_ent(spa, t, q, zio_execute, zio, flags,
1910 zio_taskq_member(zio_t *zio, zio_taskq_type_t q)
1912 spa_t *spa = zio->io_spa;
1914 taskq_t *tq = taskq_of_curthread();
1916 for (zio_type_t t = 0; t < ZIO_TYPES; t++) {
1917 spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
1919 for (i = 0; i < tqs->stqs_count; i++) {
1920 if (tqs->stqs_taskq[i] == tq)
1929 zio_issue_async(zio_t *zio)
1931 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE);
1937 zio_interrupt(void *zio)
1939 zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE);
1943 zio_delay_interrupt(zio_t *zio)
1946 * The timeout_generic() function isn't defined in userspace, so
1947 * rather than trying to implement the function, the zio delay
1948 * functionality has been disabled for userspace builds.
1953 * If io_target_timestamp is zero, then no delay has been registered
1954 * for this IO, thus jump to the end of this function and "skip" the
1955 * delay; issuing it directly to the zio layer.
1957 if (zio->io_target_timestamp != 0) {
1958 hrtime_t now = gethrtime();
1960 if (now >= zio->io_target_timestamp) {
1962 * This IO has already taken longer than the target
1963 * delay to complete, so we don't want to delay it
1964 * any longer; we "miss" the delay and issue it
1965 * directly to the zio layer. This is likely due to
1966 * the target latency being set to a value less than
1967 * the underlying hardware can satisfy (e.g. delay
1968 * set to 1ms, but the disks take 10ms to complete an
1972 DTRACE_PROBE2(zio__delay__miss, zio_t *, zio,
1978 hrtime_t diff = zio->io_target_timestamp - now;
1979 clock_t expire_at_tick = ddi_get_lbolt() +
1982 DTRACE_PROBE3(zio__delay__hit, zio_t *, zio,
1983 hrtime_t, now, hrtime_t, diff);
1985 if (NSEC_TO_TICK(diff) == 0) {
1986 /* Our delay is less than a jiffy - just spin */
1987 zfs_sleep_until(zio->io_target_timestamp);
1991 * Use taskq_dispatch_delay() in the place of
1992 * OpenZFS's timeout_generic().
1994 tid = taskq_dispatch_delay(system_taskq,
1995 zio_interrupt, zio, TQ_NOSLEEP,
1997 if (tid == TASKQID_INVALID) {
1999 * Couldn't allocate a task. Just
2000 * finish the zio without a delay.
2009 DTRACE_PROBE1(zio__delay__skip, zio_t *, zio);
2014 zio_deadman_impl(zio_t *pio, int ziodepth)
2016 zio_t *cio, *cio_next;
2017 zio_link_t *zl = NULL;
2018 vdev_t *vd = pio->io_vd;
2020 if (zio_deadman_log_all || (vd != NULL && vd->vdev_ops->vdev_op_leaf)) {
2021 vdev_queue_t *vq = vd ? &vd->vdev_queue : NULL;
2022 zbookmark_phys_t *zb = &pio->io_bookmark;
2023 uint64_t delta = gethrtime() - pio->io_timestamp;
2024 uint64_t failmode = spa_get_deadman_failmode(pio->io_spa);
2026 zfs_dbgmsg("slow zio[%d]: zio=%px timestamp=%llu "
2027 "delta=%llu queued=%llu io=%llu "
2029 "last=%llu type=%d "
2030 "priority=%d flags=0x%x stage=0x%x "
2031 "pipeline=0x%x pipeline-trace=0x%x "
2032 "objset=%llu object=%llu "
2033 "level=%llu blkid=%llu "
2034 "offset=%llu size=%llu "
2036 ziodepth, pio, pio->io_timestamp,
2037 (u_longlong_t)delta, pio->io_delta, pio->io_delay,
2038 vd ? vd->vdev_path : "NULL",
2039 vq ? vq->vq_io_complete_ts : 0, pio->io_type,
2040 pio->io_priority, pio->io_flags, pio->io_stage,
2041 pio->io_pipeline, pio->io_pipeline_trace,
2042 (u_longlong_t)zb->zb_objset, (u_longlong_t)zb->zb_object,
2043 (u_longlong_t)zb->zb_level, (u_longlong_t)zb->zb_blkid,
2044 (u_longlong_t)pio->io_offset, (u_longlong_t)pio->io_size,
2046 (void) zfs_ereport_post(FM_EREPORT_ZFS_DEADMAN,
2047 pio->io_spa, vd, zb, pio, 0);
2049 if (failmode == ZIO_FAILURE_MODE_CONTINUE &&
2050 taskq_empty_ent(&pio->io_tqent)) {
2055 mutex_enter(&pio->io_lock);
2056 for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) {
2057 cio_next = zio_walk_children(pio, &zl);
2058 zio_deadman_impl(cio, ziodepth + 1);
2060 mutex_exit(&pio->io_lock);
2064 * Log the critical information describing this zio and all of its children
2065 * using the zfs_dbgmsg() interface then post deadman event for the ZED.
2068 zio_deadman(zio_t *pio, char *tag)
2070 spa_t *spa = pio->io_spa;
2071 char *name = spa_name(spa);
2073 if (!zfs_deadman_enabled || spa_suspended(spa))
2076 zio_deadman_impl(pio, 0);
2078 switch (spa_get_deadman_failmode(spa)) {
2079 case ZIO_FAILURE_MODE_WAIT:
2080 zfs_dbgmsg("%s waiting for hung I/O to pool '%s'", tag, name);
2083 case ZIO_FAILURE_MODE_CONTINUE:
2084 zfs_dbgmsg("%s restarting hung I/O for pool '%s'", tag, name);
2087 case ZIO_FAILURE_MODE_PANIC:
2088 fm_panic("%s determined I/O to pool '%s' is hung.", tag, name);
2094 * Execute the I/O pipeline until one of the following occurs:
2095 * (1) the I/O completes; (2) the pipeline stalls waiting for
2096 * dependent child I/Os; (3) the I/O issues, so we're waiting
2097 * for an I/O completion interrupt; (4) the I/O is delegated by
2098 * vdev-level caching or aggregation; (5) the I/O is deferred
2099 * due to vdev-level queueing; (6) the I/O is handed off to
2100 * another thread. In all cases, the pipeline stops whenever
2101 * there's no CPU work; it never burns a thread in cv_wait_io().
2103 * There's no locking on io_stage because there's no legitimate way
2104 * for multiple threads to be attempting to process the same I/O.
2106 static zio_pipe_stage_t *zio_pipeline[];
2109 * zio_execute() is a wrapper around the static function
2110 * __zio_execute() so that we can force __zio_execute() to be
2111 * inlined. This reduces stack overhead which is important
2112 * because __zio_execute() is called recursively in several zio
2113 * code paths. zio_execute() itself cannot be inlined because
2114 * it is externally visible.
2117 zio_execute(void *zio)
2119 fstrans_cookie_t cookie;
2121 cookie = spl_fstrans_mark();
2123 spl_fstrans_unmark(cookie);
2127 * Used to determine if in the current context the stack is sized large
2128 * enough to allow zio_execute() to be called recursively. A minimum
2129 * stack size of 16K is required to avoid needing to re-dispatch the zio.
2132 zio_execute_stack_check(zio_t *zio)
2134 #if !defined(HAVE_LARGE_STACKS)
2135 dsl_pool_t *dp = spa_get_dsl(zio->io_spa);
2137 /* Executing in txg_sync_thread() context. */
2138 if (dp && curthread == dp->dp_tx.tx_sync_thread)
2141 /* Pool initialization outside of zio_taskq context. */
2142 if (dp && spa_is_initializing(dp->dp_spa) &&
2143 !zio_taskq_member(zio, ZIO_TASKQ_ISSUE) &&
2144 !zio_taskq_member(zio, ZIO_TASKQ_ISSUE_HIGH))
2146 #endif /* HAVE_LARGE_STACKS */
2151 __attribute__((always_inline))
2153 __zio_execute(zio_t *zio)
2155 ASSERT3U(zio->io_queued_timestamp, >, 0);
2157 while (zio->io_stage < ZIO_STAGE_DONE) {
2158 enum zio_stage pipeline = zio->io_pipeline;
2159 enum zio_stage stage = zio->io_stage;
2161 zio->io_executor = curthread;
2163 ASSERT(!MUTEX_HELD(&zio->io_lock));
2164 ASSERT(ISP2(stage));
2165 ASSERT(zio->io_stall == NULL);
2169 } while ((stage & pipeline) == 0);
2171 ASSERT(stage <= ZIO_STAGE_DONE);
2174 * If we are in interrupt context and this pipeline stage
2175 * will grab a config lock that is held across I/O,
2176 * or may wait for an I/O that needs an interrupt thread
2177 * to complete, issue async to avoid deadlock.
2179 * For VDEV_IO_START, we cut in line so that the io will
2180 * be sent to disk promptly.
2182 if ((stage & ZIO_BLOCKING_STAGES) && zio->io_vd == NULL &&
2183 zio_taskq_member(zio, ZIO_TASKQ_INTERRUPT)) {
2184 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ?
2185 zio_requeue_io_start_cut_in_line : B_FALSE;
2186 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut);
2191 * If the current context doesn't have large enough stacks
2192 * the zio must be issued asynchronously to prevent overflow.
2194 if (zio_execute_stack_check(zio)) {
2195 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ?
2196 zio_requeue_io_start_cut_in_line : B_FALSE;
2197 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut);
2201 zio->io_stage = stage;
2202 zio->io_pipeline_trace |= zio->io_stage;
2205 * The zio pipeline stage returns the next zio to execute
2206 * (typically the same as this one), or NULL if we should
2209 zio = zio_pipeline[highbit64(stage) - 1](zio);
2218 * ==========================================================================
2219 * Initiate I/O, either sync or async
2220 * ==========================================================================
2223 zio_wait(zio_t *zio)
2226 * Some routines, like zio_free_sync(), may return a NULL zio
2227 * to avoid the performance overhead of creating and then destroying
2228 * an unneeded zio. For the callers' simplicity, we accept a NULL
2229 * zio and ignore it.
2234 long timeout = MSEC_TO_TICK(zfs_deadman_ziotime_ms);
2237 ASSERT3S(zio->io_stage, ==, ZIO_STAGE_OPEN);
2238 ASSERT3P(zio->io_executor, ==, NULL);
2240 zio->io_waiter = curthread;
2241 ASSERT0(zio->io_queued_timestamp);
2242 zio->io_queued_timestamp = gethrtime();
2246 mutex_enter(&zio->io_lock);
2247 while (zio->io_executor != NULL) {
2248 error = cv_timedwait_io(&zio->io_cv, &zio->io_lock,
2249 ddi_get_lbolt() + timeout);
2251 if (zfs_deadman_enabled && error == -1 &&
2252 gethrtime() - zio->io_queued_timestamp >
2253 spa_deadman_ziotime(zio->io_spa)) {
2254 mutex_exit(&zio->io_lock);
2255 timeout = MSEC_TO_TICK(zfs_deadman_checktime_ms);
2256 zio_deadman(zio, FTAG);
2257 mutex_enter(&zio->io_lock);
2260 mutex_exit(&zio->io_lock);
2262 error = zio->io_error;
2269 zio_nowait(zio_t *zio)
2272 * See comment in zio_wait().
2277 ASSERT3P(zio->io_executor, ==, NULL);
2279 if (zio->io_child_type == ZIO_CHILD_LOGICAL &&
2280 zio_unique_parent(zio) == NULL) {
2284 * This is a logical async I/O with no parent to wait for it.
2285 * We add it to the spa_async_root_zio "Godfather" I/O which
2286 * will ensure they complete prior to unloading the pool.
2288 spa_t *spa = zio->io_spa;
2289 pio = spa->spa_async_zio_root[CPU_SEQID_UNSTABLE];
2291 zio_add_child(pio, zio);
2294 ASSERT0(zio->io_queued_timestamp);
2295 zio->io_queued_timestamp = gethrtime();
2300 * ==========================================================================
2301 * Reexecute, cancel, or suspend/resume failed I/O
2302 * ==========================================================================
2306 zio_reexecute(void *arg)
2309 zio_t *cio, *cio_next;
2311 ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL);
2312 ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN);
2313 ASSERT(pio->io_gang_leader == NULL);
2314 ASSERT(pio->io_gang_tree == NULL);
2316 pio->io_flags = pio->io_orig_flags;
2317 pio->io_stage = pio->io_orig_stage;
2318 pio->io_pipeline = pio->io_orig_pipeline;
2319 pio->io_reexecute = 0;
2320 pio->io_flags |= ZIO_FLAG_REEXECUTED;
2321 pio->io_pipeline_trace = 0;
2323 for (int w = 0; w < ZIO_WAIT_TYPES; w++)
2324 pio->io_state[w] = 0;
2325 for (int c = 0; c < ZIO_CHILD_TYPES; c++)
2326 pio->io_child_error[c] = 0;
2328 if (IO_IS_ALLOCATING(pio))
2329 BP_ZERO(pio->io_bp);
2332 * As we reexecute pio's children, new children could be created.
2333 * New children go to the head of pio's io_child_list, however,
2334 * so we will (correctly) not reexecute them. The key is that
2335 * the remainder of pio's io_child_list, from 'cio_next' onward,
2336 * cannot be affected by any side effects of reexecuting 'cio'.
2338 zio_link_t *zl = NULL;
2339 mutex_enter(&pio->io_lock);
2340 for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) {
2341 cio_next = zio_walk_children(pio, &zl);
2342 for (int w = 0; w < ZIO_WAIT_TYPES; w++)
2343 pio->io_children[cio->io_child_type][w]++;
2344 mutex_exit(&pio->io_lock);
2346 mutex_enter(&pio->io_lock);
2348 mutex_exit(&pio->io_lock);
2351 * Now that all children have been reexecuted, execute the parent.
2352 * We don't reexecute "The Godfather" I/O here as it's the
2353 * responsibility of the caller to wait on it.
2355 if (!(pio->io_flags & ZIO_FLAG_GODFATHER)) {
2356 pio->io_queued_timestamp = gethrtime();
2362 zio_suspend(spa_t *spa, zio_t *zio, zio_suspend_reason_t reason)
2364 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC)
2365 fm_panic("Pool '%s' has encountered an uncorrectable I/O "
2366 "failure and the failure mode property for this pool "
2367 "is set to panic.", spa_name(spa));
2369 cmn_err(CE_WARN, "Pool '%s' has encountered an uncorrectable I/O "
2370 "failure and has been suspended.\n", spa_name(spa));
2372 (void) zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL,
2375 mutex_enter(&spa->spa_suspend_lock);
2377 if (spa->spa_suspend_zio_root == NULL)
2378 spa->spa_suspend_zio_root = zio_root(spa, NULL, NULL,
2379 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
2380 ZIO_FLAG_GODFATHER);
2382 spa->spa_suspended = reason;
2385 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER));
2386 ASSERT(zio != spa->spa_suspend_zio_root);
2387 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
2388 ASSERT(zio_unique_parent(zio) == NULL);
2389 ASSERT(zio->io_stage == ZIO_STAGE_DONE);
2390 zio_add_child(spa->spa_suspend_zio_root, zio);
2393 mutex_exit(&spa->spa_suspend_lock);
2397 zio_resume(spa_t *spa)
2402 * Reexecute all previously suspended i/o.
2404 mutex_enter(&spa->spa_suspend_lock);
2405 spa->spa_suspended = ZIO_SUSPEND_NONE;
2406 cv_broadcast(&spa->spa_suspend_cv);
2407 pio = spa->spa_suspend_zio_root;
2408 spa->spa_suspend_zio_root = NULL;
2409 mutex_exit(&spa->spa_suspend_lock);
2415 return (zio_wait(pio));
2419 zio_resume_wait(spa_t *spa)
2421 mutex_enter(&spa->spa_suspend_lock);
2422 while (spa_suspended(spa))
2423 cv_wait(&spa->spa_suspend_cv, &spa->spa_suspend_lock);
2424 mutex_exit(&spa->spa_suspend_lock);
2428 * ==========================================================================
2431 * A gang block is a collection of small blocks that looks to the DMU
2432 * like one large block. When zio_dva_allocate() cannot find a block
2433 * of the requested size, due to either severe fragmentation or the pool
2434 * being nearly full, it calls zio_write_gang_block() to construct the
2435 * block from smaller fragments.
2437 * A gang block consists of a gang header (zio_gbh_phys_t) and up to
2438 * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like
2439 * an indirect block: it's an array of block pointers. It consumes
2440 * only one sector and hence is allocatable regardless of fragmentation.
2441 * The gang header's bps point to its gang members, which hold the data.
2443 * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg>
2444 * as the verifier to ensure uniqueness of the SHA256 checksum.
2445 * Critically, the gang block bp's blk_cksum is the checksum of the data,
2446 * not the gang header. This ensures that data block signatures (needed for
2447 * deduplication) are independent of how the block is physically stored.
2449 * Gang blocks can be nested: a gang member may itself be a gang block.
2450 * Thus every gang block is a tree in which root and all interior nodes are
2451 * gang headers, and the leaves are normal blocks that contain user data.
2452 * The root of the gang tree is called the gang leader.
2454 * To perform any operation (read, rewrite, free, claim) on a gang block,
2455 * zio_gang_assemble() first assembles the gang tree (minus data leaves)
2456 * in the io_gang_tree field of the original logical i/o by recursively
2457 * reading the gang leader and all gang headers below it. This yields
2458 * an in-core tree containing the contents of every gang header and the
2459 * bps for every constituent of the gang block.
2461 * With the gang tree now assembled, zio_gang_issue() just walks the gang tree
2462 * and invokes a callback on each bp. To free a gang block, zio_gang_issue()
2463 * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp.
2464 * zio_claim_gang() provides a similarly trivial wrapper for zio_claim().
2465 * zio_read_gang() is a wrapper around zio_read() that omits reading gang
2466 * headers, since we already have those in io_gang_tree. zio_rewrite_gang()
2467 * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite()
2468 * of the gang header plus zio_checksum_compute() of the data to update the
2469 * gang header's blk_cksum as described above.
2471 * The two-phase assemble/issue model solves the problem of partial failure --
2472 * what if you'd freed part of a gang block but then couldn't read the
2473 * gang header for another part? Assembling the entire gang tree first
2474 * ensures that all the necessary gang header I/O has succeeded before
2475 * starting the actual work of free, claim, or write. Once the gang tree
2476 * is assembled, free and claim are in-memory operations that cannot fail.
2478 * In the event that a gang write fails, zio_dva_unallocate() walks the
2479 * gang tree to immediately free (i.e. insert back into the space map)
2480 * everything we've allocated. This ensures that we don't get ENOSPC
2481 * errors during repeated suspend/resume cycles due to a flaky device.
2483 * Gang rewrites only happen during sync-to-convergence. If we can't assemble
2484 * the gang tree, we won't modify the block, so we can safely defer the free
2485 * (knowing that the block is still intact). If we *can* assemble the gang
2486 * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free
2487 * each constituent bp and we can allocate a new block on the next sync pass.
2489 * In all cases, the gang tree allows complete recovery from partial failure.
2490 * ==========================================================================
2494 zio_gang_issue_func_done(zio_t *zio)
2496 abd_free(zio->io_abd);
2500 zio_read_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data,
2506 return (zio_read(pio, pio->io_spa, bp, abd_get_offset(data, offset),
2507 BP_GET_PSIZE(bp), zio_gang_issue_func_done,
2508 NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio),
2509 &pio->io_bookmark));
2513 zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data,
2520 abd_get_from_buf(gn->gn_gbh, SPA_GANGBLOCKSIZE);
2521 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp,
2522 gbh_abd, SPA_GANGBLOCKSIZE, zio_gang_issue_func_done, NULL,
2523 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio),
2526 * As we rewrite each gang header, the pipeline will compute
2527 * a new gang block header checksum for it; but no one will
2528 * compute a new data checksum, so we do that here. The one
2529 * exception is the gang leader: the pipeline already computed
2530 * its data checksum because that stage precedes gang assembly.
2531 * (Presently, nothing actually uses interior data checksums;
2532 * this is just good hygiene.)
2534 if (gn != pio->io_gang_leader->io_gang_tree) {
2535 abd_t *buf = abd_get_offset(data, offset);
2537 zio_checksum_compute(zio, BP_GET_CHECKSUM(bp),
2538 buf, BP_GET_PSIZE(bp));
2543 * If we are here to damage data for testing purposes,
2544 * leave the GBH alone so that we can detect the damage.
2546 if (pio->io_gang_leader->io_flags & ZIO_FLAG_INDUCE_DAMAGE)
2547 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES;
2549 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp,
2550 abd_get_offset(data, offset), BP_GET_PSIZE(bp),
2551 zio_gang_issue_func_done, NULL, pio->io_priority,
2552 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark);
2560 zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data,
2563 zio_t *zio = zio_free_sync(pio, pio->io_spa, pio->io_txg, bp,
2564 ZIO_GANG_CHILD_FLAGS(pio));
2566 zio = zio_null(pio, pio->io_spa,
2567 NULL, NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio));
2574 zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data,
2577 return (zio_claim(pio, pio->io_spa, pio->io_txg, bp,
2578 NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio)));
2581 static zio_gang_issue_func_t *zio_gang_issue_func[ZIO_TYPES] = {
2590 static void zio_gang_tree_assemble_done(zio_t *zio);
2592 static zio_gang_node_t *
2593 zio_gang_node_alloc(zio_gang_node_t **gnpp)
2595 zio_gang_node_t *gn;
2597 ASSERT(*gnpp == NULL);
2599 gn = kmem_zalloc(sizeof (*gn), KM_SLEEP);
2600 gn->gn_gbh = zio_buf_alloc(SPA_GANGBLOCKSIZE);
2607 zio_gang_node_free(zio_gang_node_t **gnpp)
2609 zio_gang_node_t *gn = *gnpp;
2611 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++)
2612 ASSERT(gn->gn_child[g] == NULL);
2614 zio_buf_free(gn->gn_gbh, SPA_GANGBLOCKSIZE);
2615 kmem_free(gn, sizeof (*gn));
2620 zio_gang_tree_free(zio_gang_node_t **gnpp)
2622 zio_gang_node_t *gn = *gnpp;
2627 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++)
2628 zio_gang_tree_free(&gn->gn_child[g]);
2630 zio_gang_node_free(gnpp);
2634 zio_gang_tree_assemble(zio_t *gio, blkptr_t *bp, zio_gang_node_t **gnpp)
2636 zio_gang_node_t *gn = zio_gang_node_alloc(gnpp);
2637 abd_t *gbh_abd = abd_get_from_buf(gn->gn_gbh, SPA_GANGBLOCKSIZE);
2639 ASSERT(gio->io_gang_leader == gio);
2640 ASSERT(BP_IS_GANG(bp));
2642 zio_nowait(zio_read(gio, gio->io_spa, bp, gbh_abd, SPA_GANGBLOCKSIZE,
2643 zio_gang_tree_assemble_done, gn, gio->io_priority,
2644 ZIO_GANG_CHILD_FLAGS(gio), &gio->io_bookmark));
2648 zio_gang_tree_assemble_done(zio_t *zio)
2650 zio_t *gio = zio->io_gang_leader;
2651 zio_gang_node_t *gn = zio->io_private;
2652 blkptr_t *bp = zio->io_bp;
2654 ASSERT(gio == zio_unique_parent(zio));
2655 ASSERT(zio->io_child_count == 0);
2660 /* this ABD was created from a linear buf in zio_gang_tree_assemble */
2661 if (BP_SHOULD_BYTESWAP(bp))
2662 byteswap_uint64_array(abd_to_buf(zio->io_abd), zio->io_size);
2664 ASSERT3P(abd_to_buf(zio->io_abd), ==, gn->gn_gbh);
2665 ASSERT(zio->io_size == SPA_GANGBLOCKSIZE);
2666 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC);
2668 abd_free(zio->io_abd);
2670 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) {
2671 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g];
2672 if (!BP_IS_GANG(gbp))
2674 zio_gang_tree_assemble(gio, gbp, &gn->gn_child[g]);
2679 zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, abd_t *data,
2682 zio_t *gio = pio->io_gang_leader;
2685 ASSERT(BP_IS_GANG(bp) == !!gn);
2686 ASSERT(BP_GET_CHECKSUM(bp) == BP_GET_CHECKSUM(gio->io_bp));
2687 ASSERT(BP_GET_LSIZE(bp) == BP_GET_PSIZE(bp) || gn == gio->io_gang_tree);
2690 * If you're a gang header, your data is in gn->gn_gbh.
2691 * If you're a gang member, your data is in 'data' and gn == NULL.
2693 zio = zio_gang_issue_func[gio->io_type](pio, bp, gn, data, offset);
2696 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC);
2698 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) {
2699 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g];
2700 if (BP_IS_HOLE(gbp))
2702 zio_gang_tree_issue(zio, gn->gn_child[g], gbp, data,
2704 offset += BP_GET_PSIZE(gbp);
2708 if (gn == gio->io_gang_tree)
2709 ASSERT3U(gio->io_size, ==, offset);
2716 zio_gang_assemble(zio_t *zio)
2718 blkptr_t *bp = zio->io_bp;
2720 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == NULL);
2721 ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
2723 zio->io_gang_leader = zio;
2725 zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree);
2731 zio_gang_issue(zio_t *zio)
2733 blkptr_t *bp = zio->io_bp;
2735 if (zio_wait_for_children(zio, ZIO_CHILD_GANG_BIT, ZIO_WAIT_DONE)) {
2739 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio);
2740 ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
2742 if (zio->io_child_error[ZIO_CHILD_GANG] == 0)
2743 zio_gang_tree_issue(zio, zio->io_gang_tree, bp, zio->io_abd,
2746 zio_gang_tree_free(&zio->io_gang_tree);
2748 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
2754 zio_write_gang_member_ready(zio_t *zio)
2756 zio_t *pio = zio_unique_parent(zio);
2757 dva_t *cdva = zio->io_bp->blk_dva;
2758 dva_t *pdva = pio->io_bp->blk_dva;
2760 zio_t *gio __maybe_unused = zio->io_gang_leader;
2762 if (BP_IS_HOLE(zio->io_bp))
2765 ASSERT(BP_IS_HOLE(&zio->io_bp_orig));
2767 ASSERT(zio->io_child_type == ZIO_CHILD_GANG);
2768 ASSERT3U(zio->io_prop.zp_copies, ==, gio->io_prop.zp_copies);
2769 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp));
2770 ASSERT3U(pio->io_prop.zp_copies, <=, BP_GET_NDVAS(pio->io_bp));
2771 ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp));
2773 mutex_enter(&pio->io_lock);
2774 for (int d = 0; d < BP_GET_NDVAS(zio->io_bp); d++) {
2775 ASSERT(DVA_GET_GANG(&pdva[d]));
2776 asize = DVA_GET_ASIZE(&pdva[d]);
2777 asize += DVA_GET_ASIZE(&cdva[d]);
2778 DVA_SET_ASIZE(&pdva[d], asize);
2780 mutex_exit(&pio->io_lock);
2784 zio_write_gang_done(zio_t *zio)
2787 * The io_abd field will be NULL for a zio with no data. The io_flags
2788 * will initially have the ZIO_FLAG_NODATA bit flag set, but we can't
2789 * check for it here as it is cleared in zio_ready.
2791 if (zio->io_abd != NULL)
2792 abd_free(zio->io_abd);
2796 zio_write_gang_block(zio_t *pio, metaslab_class_t *mc)
2798 spa_t *spa = pio->io_spa;
2799 blkptr_t *bp = pio->io_bp;
2800 zio_t *gio = pio->io_gang_leader;
2802 zio_gang_node_t *gn, **gnpp;
2803 zio_gbh_phys_t *gbh;
2805 uint64_t txg = pio->io_txg;
2806 uint64_t resid = pio->io_size;
2808 int copies = gio->io_prop.zp_copies;
2812 boolean_t has_data = !(pio->io_flags & ZIO_FLAG_NODATA);
2815 * encrypted blocks need DVA[2] free so encrypted gang headers can't
2816 * have a third copy.
2818 gbh_copies = MIN(copies + 1, spa_max_replication(spa));
2819 if (gio->io_prop.zp_encrypt && gbh_copies >= SPA_DVAS_PER_BP)
2820 gbh_copies = SPA_DVAS_PER_BP - 1;
2822 int flags = METASLAB_HINTBP_FAVOR | METASLAB_GANG_HEADER;
2823 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) {
2824 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE);
2827 flags |= METASLAB_ASYNC_ALLOC;
2828 VERIFY(zfs_refcount_held(&mc->mc_allocator[pio->io_allocator].
2829 mca_alloc_slots, pio));
2832 * The logical zio has already placed a reservation for
2833 * 'copies' allocation slots but gang blocks may require
2834 * additional copies. These additional copies
2835 * (i.e. gbh_copies - copies) are guaranteed to succeed
2836 * since metaslab_class_throttle_reserve() always allows
2837 * additional reservations for gang blocks.
2839 VERIFY(metaslab_class_throttle_reserve(mc, gbh_copies - copies,
2840 pio->io_allocator, pio, flags));
2843 error = metaslab_alloc(spa, mc, SPA_GANGBLOCKSIZE,
2844 bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp, flags,
2845 &pio->io_alloc_list, pio, pio->io_allocator);
2847 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) {
2848 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE);
2852 * If we failed to allocate the gang block header then
2853 * we remove any additional allocation reservations that
2854 * we placed here. The original reservation will
2855 * be removed when the logical I/O goes to the ready
2858 metaslab_class_throttle_unreserve(mc,
2859 gbh_copies - copies, pio->io_allocator, pio);
2862 pio->io_error = error;
2867 gnpp = &gio->io_gang_tree;
2869 gnpp = pio->io_private;
2870 ASSERT(pio->io_ready == zio_write_gang_member_ready);
2873 gn = zio_gang_node_alloc(gnpp);
2875 bzero(gbh, SPA_GANGBLOCKSIZE);
2876 gbh_abd = abd_get_from_buf(gbh, SPA_GANGBLOCKSIZE);
2879 * Create the gang header.
2881 zio = zio_rewrite(pio, spa, txg, bp, gbh_abd, SPA_GANGBLOCKSIZE,
2882 zio_write_gang_done, NULL, pio->io_priority,
2883 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark);
2886 * Create and nowait the gang children.
2888 for (int g = 0; resid != 0; resid -= lsize, g++) {
2889 lsize = P2ROUNDUP(resid / (SPA_GBH_NBLKPTRS - g),
2891 ASSERT(lsize >= SPA_MINBLOCKSIZE && lsize <= resid);
2893 zp.zp_checksum = gio->io_prop.zp_checksum;
2894 zp.zp_compress = ZIO_COMPRESS_OFF;
2895 zp.zp_complevel = gio->io_prop.zp_complevel;
2896 zp.zp_type = DMU_OT_NONE;
2898 zp.zp_copies = gio->io_prop.zp_copies;
2899 zp.zp_dedup = B_FALSE;
2900 zp.zp_dedup_verify = B_FALSE;
2901 zp.zp_nopwrite = B_FALSE;
2902 zp.zp_encrypt = gio->io_prop.zp_encrypt;
2903 zp.zp_byteorder = gio->io_prop.zp_byteorder;
2904 bzero(zp.zp_salt, ZIO_DATA_SALT_LEN);
2905 bzero(zp.zp_iv, ZIO_DATA_IV_LEN);
2906 bzero(zp.zp_mac, ZIO_DATA_MAC_LEN);
2908 zio_t *cio = zio_write(zio, spa, txg, &gbh->zg_blkptr[g],
2909 has_data ? abd_get_offset(pio->io_abd, pio->io_size -
2910 resid) : NULL, lsize, lsize, &zp,
2911 zio_write_gang_member_ready, NULL, NULL,
2912 zio_write_gang_done, &gn->gn_child[g], pio->io_priority,
2913 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark);
2915 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) {
2916 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE);
2920 * Gang children won't throttle but we should
2921 * account for their work, so reserve an allocation
2922 * slot for them here.
2924 VERIFY(metaslab_class_throttle_reserve(mc,
2925 zp.zp_copies, cio->io_allocator, cio, flags));
2931 * Set pio's pipeline to just wait for zio to finish.
2933 pio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
2936 * We didn't allocate this bp, so make sure it doesn't get unmarked.
2938 pio->io_flags &= ~ZIO_FLAG_FASTWRITE;
2946 * The zio_nop_write stage in the pipeline determines if allocating a
2947 * new bp is necessary. The nopwrite feature can handle writes in
2948 * either syncing or open context (i.e. zil writes) and as a result is
2949 * mutually exclusive with dedup.
2951 * By leveraging a cryptographically secure checksum, such as SHA256, we
2952 * can compare the checksums of the new data and the old to determine if
2953 * allocating a new block is required. Note that our requirements for
2954 * cryptographic strength are fairly weak: there can't be any accidental
2955 * hash collisions, but we don't need to be secure against intentional
2956 * (malicious) collisions. To trigger a nopwrite, you have to be able
2957 * to write the file to begin with, and triggering an incorrect (hash
2958 * collision) nopwrite is no worse than simply writing to the file.
2959 * That said, there are no known attacks against the checksum algorithms
2960 * used for nopwrite, assuming that the salt and the checksums
2961 * themselves remain secret.
2964 zio_nop_write(zio_t *zio)
2966 blkptr_t *bp = zio->io_bp;
2967 blkptr_t *bp_orig = &zio->io_bp_orig;
2968 zio_prop_t *zp = &zio->io_prop;
2970 ASSERT(BP_GET_LEVEL(bp) == 0);
2971 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE));
2972 ASSERT(zp->zp_nopwrite);
2973 ASSERT(!zp->zp_dedup);
2974 ASSERT(zio->io_bp_override == NULL);
2975 ASSERT(IO_IS_ALLOCATING(zio));
2978 * Check to see if the original bp and the new bp have matching
2979 * characteristics (i.e. same checksum, compression algorithms, etc).
2980 * If they don't then just continue with the pipeline which will
2981 * allocate a new bp.
2983 if (BP_IS_HOLE(bp_orig) ||
2984 !(zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_flags &
2985 ZCHECKSUM_FLAG_NOPWRITE) ||
2986 BP_IS_ENCRYPTED(bp) || BP_IS_ENCRYPTED(bp_orig) ||
2987 BP_GET_CHECKSUM(bp) != BP_GET_CHECKSUM(bp_orig) ||
2988 BP_GET_COMPRESS(bp) != BP_GET_COMPRESS(bp_orig) ||
2989 BP_GET_DEDUP(bp) != BP_GET_DEDUP(bp_orig) ||
2990 zp->zp_copies != BP_GET_NDVAS(bp_orig))
2994 * If the checksums match then reset the pipeline so that we
2995 * avoid allocating a new bp and issuing any I/O.
2997 if (ZIO_CHECKSUM_EQUAL(bp->blk_cksum, bp_orig->blk_cksum)) {
2998 ASSERT(zio_checksum_table[zp->zp_checksum].ci_flags &
2999 ZCHECKSUM_FLAG_NOPWRITE);
3000 ASSERT3U(BP_GET_PSIZE(bp), ==, BP_GET_PSIZE(bp_orig));
3001 ASSERT3U(BP_GET_LSIZE(bp), ==, BP_GET_LSIZE(bp_orig));
3002 ASSERT(zp->zp_compress != ZIO_COMPRESS_OFF);
3003 ASSERT(bcmp(&bp->blk_prop, &bp_orig->blk_prop,
3004 sizeof (uint64_t)) == 0);
3007 * If we're overwriting a block that is currently on an
3008 * indirect vdev, then ignore the nopwrite request and
3009 * allow a new block to be allocated on a concrete vdev.
3011 spa_config_enter(zio->io_spa, SCL_VDEV, FTAG, RW_READER);
3012 vdev_t *tvd = vdev_lookup_top(zio->io_spa,
3013 DVA_GET_VDEV(&bp->blk_dva[0]));
3014 if (tvd->vdev_ops == &vdev_indirect_ops) {
3015 spa_config_exit(zio->io_spa, SCL_VDEV, FTAG);
3018 spa_config_exit(zio->io_spa, SCL_VDEV, FTAG);
3021 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
3022 zio->io_flags |= ZIO_FLAG_NOPWRITE;
3029 * ==========================================================================
3031 * ==========================================================================
3034 zio_ddt_child_read_done(zio_t *zio)
3036 blkptr_t *bp = zio->io_bp;
3037 ddt_entry_t *dde = zio->io_private;
3039 zio_t *pio = zio_unique_parent(zio);
3041 mutex_enter(&pio->io_lock);
3042 ddp = ddt_phys_select(dde, bp);
3043 if (zio->io_error == 0)
3044 ddt_phys_clear(ddp); /* this ddp doesn't need repair */
3046 if (zio->io_error == 0 && dde->dde_repair_abd == NULL)
3047 dde->dde_repair_abd = zio->io_abd;
3049 abd_free(zio->io_abd);
3050 mutex_exit(&pio->io_lock);
3054 zio_ddt_read_start(zio_t *zio)
3056 blkptr_t *bp = zio->io_bp;
3058 ASSERT(BP_GET_DEDUP(bp));
3059 ASSERT(BP_GET_PSIZE(bp) == zio->io_size);
3060 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
3062 if (zio->io_child_error[ZIO_CHILD_DDT]) {
3063 ddt_t *ddt = ddt_select(zio->io_spa, bp);
3064 ddt_entry_t *dde = ddt_repair_start(ddt, bp);
3065 ddt_phys_t *ddp = dde->dde_phys;
3066 ddt_phys_t *ddp_self = ddt_phys_select(dde, bp);
3069 ASSERT(zio->io_vsd == NULL);
3072 if (ddp_self == NULL)
3075 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
3076 if (ddp->ddp_phys_birth == 0 || ddp == ddp_self)
3078 ddt_bp_create(ddt->ddt_checksum, &dde->dde_key, ddp,
3080 zio_nowait(zio_read(zio, zio->io_spa, &blk,
3081 abd_alloc_for_io(zio->io_size, B_TRUE),
3082 zio->io_size, zio_ddt_child_read_done, dde,
3083 zio->io_priority, ZIO_DDT_CHILD_FLAGS(zio) |
3084 ZIO_FLAG_DONT_PROPAGATE, &zio->io_bookmark));
3089 zio_nowait(zio_read(zio, zio->io_spa, bp,
3090 zio->io_abd, zio->io_size, NULL, NULL, zio->io_priority,
3091 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark));
3097 zio_ddt_read_done(zio_t *zio)
3099 blkptr_t *bp = zio->io_bp;
3101 if (zio_wait_for_children(zio, ZIO_CHILD_DDT_BIT, ZIO_WAIT_DONE)) {
3105 ASSERT(BP_GET_DEDUP(bp));
3106 ASSERT(BP_GET_PSIZE(bp) == zio->io_size);
3107 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
3109 if (zio->io_child_error[ZIO_CHILD_DDT]) {
3110 ddt_t *ddt = ddt_select(zio->io_spa, bp);
3111 ddt_entry_t *dde = zio->io_vsd;
3113 ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE);
3117 zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1;
3118 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE);
3121 if (dde->dde_repair_abd != NULL) {
3122 abd_copy(zio->io_abd, dde->dde_repair_abd,
3124 zio->io_child_error[ZIO_CHILD_DDT] = 0;
3126 ddt_repair_done(ddt, dde);
3130 ASSERT(zio->io_vsd == NULL);
3136 zio_ddt_collision(zio_t *zio, ddt_t *ddt, ddt_entry_t *dde)
3138 spa_t *spa = zio->io_spa;
3139 boolean_t do_raw = !!(zio->io_flags & ZIO_FLAG_RAW);
3141 ASSERT(!(zio->io_bp_override && do_raw));
3144 * Note: we compare the original data, not the transformed data,
3145 * because when zio->io_bp is an override bp, we will not have
3146 * pushed the I/O transforms. That's an important optimization
3147 * because otherwise we'd compress/encrypt all dmu_sync() data twice.
3148 * However, we should never get a raw, override zio so in these
3149 * cases we can compare the io_abd directly. This is useful because
3150 * it allows us to do dedup verification even if we don't have access
3151 * to the original data (for instance, if the encryption keys aren't
3155 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) {
3156 zio_t *lio = dde->dde_lead_zio[p];
3158 if (lio != NULL && do_raw) {
3159 return (lio->io_size != zio->io_size ||
3160 abd_cmp(zio->io_abd, lio->io_abd) != 0);
3161 } else if (lio != NULL) {
3162 return (lio->io_orig_size != zio->io_orig_size ||
3163 abd_cmp(zio->io_orig_abd, lio->io_orig_abd) != 0);
3167 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) {
3168 ddt_phys_t *ddp = &dde->dde_phys[p];
3170 if (ddp->ddp_phys_birth != 0 && do_raw) {
3171 blkptr_t blk = *zio->io_bp;
3176 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth);
3177 psize = BP_GET_PSIZE(&blk);
3179 if (psize != zio->io_size)
3184 tmpabd = abd_alloc_for_io(psize, B_TRUE);
3186 error = zio_wait(zio_read(NULL, spa, &blk, tmpabd,
3187 psize, NULL, NULL, ZIO_PRIORITY_SYNC_READ,
3188 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
3189 ZIO_FLAG_RAW, &zio->io_bookmark));
3192 if (abd_cmp(tmpabd, zio->io_abd) != 0)
3193 error = SET_ERROR(ENOENT);
3198 return (error != 0);
3199 } else if (ddp->ddp_phys_birth != 0) {
3200 arc_buf_t *abuf = NULL;
3201 arc_flags_t aflags = ARC_FLAG_WAIT;
3202 blkptr_t blk = *zio->io_bp;
3205 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth);
3207 if (BP_GET_LSIZE(&blk) != zio->io_orig_size)
3212 error = arc_read(NULL, spa, &blk,
3213 arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ,
3214 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
3215 &aflags, &zio->io_bookmark);
3218 if (abd_cmp_buf(zio->io_orig_abd, abuf->b_data,
3219 zio->io_orig_size) != 0)
3220 error = SET_ERROR(ENOENT);
3221 arc_buf_destroy(abuf, &abuf);
3225 return (error != 0);
3233 zio_ddt_child_write_ready(zio_t *zio)
3235 int p = zio->io_prop.zp_copies;
3236 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp);
3237 ddt_entry_t *dde = zio->io_private;
3238 ddt_phys_t *ddp = &dde->dde_phys[p];
3246 ASSERT(dde->dde_lead_zio[p] == zio);
3248 ddt_phys_fill(ddp, zio->io_bp);
3250 zio_link_t *zl = NULL;
3251 while ((pio = zio_walk_parents(zio, &zl)) != NULL)
3252 ddt_bp_fill(ddp, pio->io_bp, zio->io_txg);
3258 zio_ddt_child_write_done(zio_t *zio)
3260 int p = zio->io_prop.zp_copies;
3261 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp);
3262 ddt_entry_t *dde = zio->io_private;
3263 ddt_phys_t *ddp = &dde->dde_phys[p];
3267 ASSERT(ddp->ddp_refcnt == 0);
3268 ASSERT(dde->dde_lead_zio[p] == zio);
3269 dde->dde_lead_zio[p] = NULL;
3271 if (zio->io_error == 0) {
3272 zio_link_t *zl = NULL;
3273 while (zio_walk_parents(zio, &zl) != NULL)
3274 ddt_phys_addref(ddp);
3276 ddt_phys_clear(ddp);
3283 zio_ddt_write(zio_t *zio)
3285 spa_t *spa = zio->io_spa;
3286 blkptr_t *bp = zio->io_bp;
3287 uint64_t txg = zio->io_txg;
3288 zio_prop_t *zp = &zio->io_prop;
3289 int p = zp->zp_copies;
3291 ddt_t *ddt = ddt_select(spa, bp);
3295 ASSERT(BP_GET_DEDUP(bp));
3296 ASSERT(BP_GET_CHECKSUM(bp) == zp->zp_checksum);
3297 ASSERT(BP_IS_HOLE(bp) || zio->io_bp_override);
3298 ASSERT(!(zio->io_bp_override && (zio->io_flags & ZIO_FLAG_RAW)));
3301 dde = ddt_lookup(ddt, bp, B_TRUE);
3302 ddp = &dde->dde_phys[p];
3304 if (zp->zp_dedup_verify && zio_ddt_collision(zio, ddt, dde)) {
3306 * If we're using a weak checksum, upgrade to a strong checksum
3307 * and try again. If we're already using a strong checksum,
3308 * we can't resolve it, so just convert to an ordinary write.
3309 * (And automatically e-mail a paper to Nature?)
3311 if (!(zio_checksum_table[zp->zp_checksum].ci_flags &
3312 ZCHECKSUM_FLAG_DEDUP)) {
3313 zp->zp_checksum = spa_dedup_checksum(spa);
3314 zio_pop_transforms(zio);
3315 zio->io_stage = ZIO_STAGE_OPEN;
3318 zp->zp_dedup = B_FALSE;
3319 BP_SET_DEDUP(bp, B_FALSE);
3321 ASSERT(!BP_GET_DEDUP(bp));
3322 zio->io_pipeline = ZIO_WRITE_PIPELINE;
3327 if (ddp->ddp_phys_birth != 0 || dde->dde_lead_zio[p] != NULL) {
3328 if (ddp->ddp_phys_birth != 0)
3329 ddt_bp_fill(ddp, bp, txg);
3330 if (dde->dde_lead_zio[p] != NULL)
3331 zio_add_child(zio, dde->dde_lead_zio[p]);
3333 ddt_phys_addref(ddp);
3334 } else if (zio->io_bp_override) {
3335 ASSERT(bp->blk_birth == txg);
3336 ASSERT(BP_EQUAL(bp, zio->io_bp_override));
3337 ddt_phys_fill(ddp, bp);
3338 ddt_phys_addref(ddp);
3340 cio = zio_write(zio, spa, txg, bp, zio->io_orig_abd,
3341 zio->io_orig_size, zio->io_orig_size, zp,
3342 zio_ddt_child_write_ready, NULL, NULL,
3343 zio_ddt_child_write_done, dde, zio->io_priority,
3344 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark);
3346 zio_push_transform(cio, zio->io_abd, zio->io_size, 0, NULL);
3347 dde->dde_lead_zio[p] = cio;
3357 ddt_entry_t *freedde; /* for debugging */
3360 zio_ddt_free(zio_t *zio)
3362 spa_t *spa = zio->io_spa;
3363 blkptr_t *bp = zio->io_bp;
3364 ddt_t *ddt = ddt_select(spa, bp);
3368 ASSERT(BP_GET_DEDUP(bp));
3369 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
3372 freedde = dde = ddt_lookup(ddt, bp, B_TRUE);
3374 ddp = ddt_phys_select(dde, bp);
3376 ddt_phys_decref(ddp);
3384 * ==========================================================================
3385 * Allocate and free blocks
3386 * ==========================================================================
3390 zio_io_to_allocate(spa_t *spa, int allocator)
3394 ASSERT(MUTEX_HELD(&spa->spa_allocs[allocator].spaa_lock));
3396 zio = avl_first(&spa->spa_allocs[allocator].spaa_tree);
3400 ASSERT(IO_IS_ALLOCATING(zio));
3403 * Try to place a reservation for this zio. If we're unable to
3404 * reserve then we throttle.
3406 ASSERT3U(zio->io_allocator, ==, allocator);
3407 if (!metaslab_class_throttle_reserve(zio->io_metaslab_class,
3408 zio->io_prop.zp_copies, allocator, zio, 0)) {
3412 avl_remove(&spa->spa_allocs[allocator].spaa_tree, zio);
3413 ASSERT3U(zio->io_stage, <, ZIO_STAGE_DVA_ALLOCATE);
3419 zio_dva_throttle(zio_t *zio)
3421 spa_t *spa = zio->io_spa;
3423 metaslab_class_t *mc;
3425 /* locate an appropriate allocation class */
3426 mc = spa_preferred_class(spa, zio->io_size, zio->io_prop.zp_type,
3427 zio->io_prop.zp_level, zio->io_prop.zp_zpl_smallblk);
3429 if (zio->io_priority == ZIO_PRIORITY_SYNC_WRITE ||
3430 !mc->mc_alloc_throttle_enabled ||
3431 zio->io_child_type == ZIO_CHILD_GANG ||
3432 zio->io_flags & ZIO_FLAG_NODATA) {
3436 ASSERT(zio->io_type == ZIO_TYPE_WRITE);
3437 ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
3438 ASSERT3U(zio->io_queued_timestamp, >, 0);
3439 ASSERT(zio->io_stage == ZIO_STAGE_DVA_THROTTLE);
3441 zbookmark_phys_t *bm = &zio->io_bookmark;
3443 * We want to try to use as many allocators as possible to help improve
3444 * performance, but we also want logically adjacent IOs to be physically
3445 * adjacent to improve sequential read performance. We chunk each object
3446 * into 2^20 block regions, and then hash based on the objset, object,
3447 * level, and region to accomplish both of these goals.
3449 int allocator = (uint_t)cityhash4(bm->zb_objset, bm->zb_object,
3450 bm->zb_level, bm->zb_blkid >> 20) % spa->spa_alloc_count;
3451 zio->io_allocator = allocator;
3452 zio->io_metaslab_class = mc;
3453 mutex_enter(&spa->spa_allocs[allocator].spaa_lock);
3454 avl_add(&spa->spa_allocs[allocator].spaa_tree, zio);
3455 nio = zio_io_to_allocate(spa, allocator);
3456 mutex_exit(&spa->spa_allocs[allocator].spaa_lock);
3461 zio_allocate_dispatch(spa_t *spa, int allocator)
3465 mutex_enter(&spa->spa_allocs[allocator].spaa_lock);
3466 zio = zio_io_to_allocate(spa, allocator);
3467 mutex_exit(&spa->spa_allocs[allocator].spaa_lock);
3471 ASSERT3U(zio->io_stage, ==, ZIO_STAGE_DVA_THROTTLE);
3472 ASSERT0(zio->io_error);
3473 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_TRUE);
3477 zio_dva_allocate(zio_t *zio)
3479 spa_t *spa = zio->io_spa;
3480 metaslab_class_t *mc;
3481 blkptr_t *bp = zio->io_bp;
3485 if (zio->io_gang_leader == NULL) {
3486 ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
3487 zio->io_gang_leader = zio;
3490 ASSERT(BP_IS_HOLE(bp));
3491 ASSERT0(BP_GET_NDVAS(bp));
3492 ASSERT3U(zio->io_prop.zp_copies, >, 0);
3493 ASSERT3U(zio->io_prop.zp_copies, <=, spa_max_replication(spa));
3494 ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp));
3496 flags |= (zio->io_flags & ZIO_FLAG_FASTWRITE) ? METASLAB_FASTWRITE : 0;
3497 if (zio->io_flags & ZIO_FLAG_NODATA)
3498 flags |= METASLAB_DONT_THROTTLE;
3499 if (zio->io_flags & ZIO_FLAG_GANG_CHILD)
3500 flags |= METASLAB_GANG_CHILD;
3501 if (zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE)
3502 flags |= METASLAB_ASYNC_ALLOC;
3505 * if not already chosen, locate an appropriate allocation class
3507 mc = zio->io_metaslab_class;
3509 mc = spa_preferred_class(spa, zio->io_size,
3510 zio->io_prop.zp_type, zio->io_prop.zp_level,
3511 zio->io_prop.zp_zpl_smallblk);
3512 zio->io_metaslab_class = mc;
3516 * Try allocating the block in the usual metaslab class.
3517 * If that's full, allocate it in the normal class.
3518 * If that's full, allocate as a gang block,
3519 * and if all are full, the allocation fails (which shouldn't happen).
3521 * Note that we do not fall back on embedded slog (ZIL) space, to
3522 * preserve unfragmented slog space, which is critical for decent
3523 * sync write performance. If a log allocation fails, we will fall
3524 * back to spa_sync() which is abysmal for performance.
3526 error = metaslab_alloc(spa, mc, zio->io_size, bp,
3527 zio->io_prop.zp_copies, zio->io_txg, NULL, flags,
3528 &zio->io_alloc_list, zio, zio->io_allocator);
3531 * Fallback to normal class when an alloc class is full
3533 if (error == ENOSPC && mc != spa_normal_class(spa)) {
3535 * If throttling, transfer reservation over to normal class.
3536 * The io_allocator slot can remain the same even though we
3537 * are switching classes.
3539 if (mc->mc_alloc_throttle_enabled &&
3540 (zio->io_flags & ZIO_FLAG_IO_ALLOCATING)) {
3541 metaslab_class_throttle_unreserve(mc,
3542 zio->io_prop.zp_copies, zio->io_allocator, zio);
3543 zio->io_flags &= ~ZIO_FLAG_IO_ALLOCATING;
3545 VERIFY(metaslab_class_throttle_reserve(
3546 spa_normal_class(spa),
3547 zio->io_prop.zp_copies, zio->io_allocator, zio,
3548 flags | METASLAB_MUST_RESERVE));
3550 zio->io_metaslab_class = mc = spa_normal_class(spa);
3551 if (zfs_flags & ZFS_DEBUG_METASLAB_ALLOC) {
3552 zfs_dbgmsg("%s: metaslab allocation failure, "
3553 "trying normal class: zio %px, size %llu, error %d",
3554 spa_name(spa), zio, (u_longlong_t)zio->io_size,
3558 error = metaslab_alloc(spa, mc, zio->io_size, bp,
3559 zio->io_prop.zp_copies, zio->io_txg, NULL, flags,
3560 &zio->io_alloc_list, zio, zio->io_allocator);
3563 if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE) {
3564 if (zfs_flags & ZFS_DEBUG_METASLAB_ALLOC) {
3565 zfs_dbgmsg("%s: metaslab allocation failure, "
3566 "trying ganging: zio %px, size %llu, error %d",
3567 spa_name(spa), zio, (u_longlong_t)zio->io_size,
3570 return (zio_write_gang_block(zio, mc));
3573 if (error != ENOSPC ||
3574 (zfs_flags & ZFS_DEBUG_METASLAB_ALLOC)) {
3575 zfs_dbgmsg("%s: metaslab allocation failure: zio %px, "
3576 "size %llu, error %d",
3577 spa_name(spa), zio, (u_longlong_t)zio->io_size,
3580 zio->io_error = error;
3587 zio_dva_free(zio_t *zio)
3589 metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE);
3595 zio_dva_claim(zio_t *zio)
3599 error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg);
3601 zio->io_error = error;
3607 * Undo an allocation. This is used by zio_done() when an I/O fails
3608 * and we want to give back the block we just allocated.
3609 * This handles both normal blocks and gang blocks.
3612 zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp)
3614 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp));
3615 ASSERT(zio->io_bp_override == NULL);
3617 if (!BP_IS_HOLE(bp))
3618 metaslab_free(zio->io_spa, bp, bp->blk_birth, B_TRUE);
3621 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) {
3622 zio_dva_unallocate(zio, gn->gn_child[g],
3623 &gn->gn_gbh->zg_blkptr[g]);
3629 * Try to allocate an intent log block. Return 0 on success, errno on failure.
3632 zio_alloc_zil(spa_t *spa, objset_t *os, uint64_t txg, blkptr_t *new_bp,
3633 uint64_t size, boolean_t *slog)
3636 zio_alloc_list_t io_alloc_list;
3638 ASSERT(txg > spa_syncing_txg(spa));
3640 metaslab_trace_init(&io_alloc_list);
3643 * Block pointer fields are useful to metaslabs for stats and debugging.
3644 * Fill in the obvious ones before calling into metaslab_alloc().
3646 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG);
3647 BP_SET_PSIZE(new_bp, size);
3648 BP_SET_LEVEL(new_bp, 0);
3651 * When allocating a zil block, we don't have information about
3652 * the final destination of the block except the objset it's part
3653 * of, so we just hash the objset ID to pick the allocator to get
3656 int flags = METASLAB_FASTWRITE | METASLAB_ZIL;
3657 int allocator = (uint_t)cityhash4(0, 0, 0,
3658 os->os_dsl_dataset->ds_object) % spa->spa_alloc_count;
3659 error = metaslab_alloc(spa, spa_log_class(spa), size, new_bp, 1,
3660 txg, NULL, flags, &io_alloc_list, NULL, allocator);
3661 *slog = (error == 0);
3663 error = metaslab_alloc(spa, spa_embedded_log_class(spa), size,
3664 new_bp, 1, txg, NULL, flags,
3665 &io_alloc_list, NULL, allocator);
3668 error = metaslab_alloc(spa, spa_normal_class(spa), size,
3669 new_bp, 1, txg, NULL, flags,
3670 &io_alloc_list, NULL, allocator);
3672 metaslab_trace_fini(&io_alloc_list);
3675 BP_SET_LSIZE(new_bp, size);
3676 BP_SET_PSIZE(new_bp, size);
3677 BP_SET_COMPRESS(new_bp, ZIO_COMPRESS_OFF);
3678 BP_SET_CHECKSUM(new_bp,
3679 spa_version(spa) >= SPA_VERSION_SLIM_ZIL
3680 ? ZIO_CHECKSUM_ZILOG2 : ZIO_CHECKSUM_ZILOG);
3681 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG);
3682 BP_SET_LEVEL(new_bp, 0);
3683 BP_SET_DEDUP(new_bp, 0);
3684 BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER);
3687 * encrypted blocks will require an IV and salt. We generate
3688 * these now since we will not be rewriting the bp at
3691 if (os->os_encrypted) {
3692 uint8_t iv[ZIO_DATA_IV_LEN];
3693 uint8_t salt[ZIO_DATA_SALT_LEN];
3695 BP_SET_CRYPT(new_bp, B_TRUE);
3696 VERIFY0(spa_crypt_get_salt(spa,
3697 dmu_objset_id(os), salt));
3698 VERIFY0(zio_crypt_generate_iv(iv));
3700 zio_crypt_encode_params_bp(new_bp, salt, iv);
3703 zfs_dbgmsg("%s: zil block allocation failure: "
3704 "size %llu, error %d", spa_name(spa), (u_longlong_t)size,
3712 * ==========================================================================
3713 * Read and write to physical devices
3714 * ==========================================================================
3718 * Issue an I/O to the underlying vdev. Typically the issue pipeline
3719 * stops after this stage and will resume upon I/O completion.
3720 * However, there are instances where the vdev layer may need to
3721 * continue the pipeline when an I/O was not issued. Since the I/O
3722 * that was sent to the vdev layer might be different than the one
3723 * currently active in the pipeline (see vdev_queue_io()), we explicitly
3724 * force the underlying vdev layers to call either zio_execute() or
3725 * zio_interrupt() to ensure that the pipeline continues with the correct I/O.
3728 zio_vdev_io_start(zio_t *zio)
3730 vdev_t *vd = zio->io_vd;
3732 spa_t *spa = zio->io_spa;
3736 ASSERT(zio->io_error == 0);
3737 ASSERT(zio->io_child_error[ZIO_CHILD_VDEV] == 0);
3740 if (!(zio->io_flags & ZIO_FLAG_CONFIG_WRITER))
3741 spa_config_enter(spa, SCL_ZIO, zio, RW_READER);
3744 * The mirror_ops handle multiple DVAs in a single BP.
3746 vdev_mirror_ops.vdev_op_io_start(zio);
3750 ASSERT3P(zio->io_logical, !=, zio);
3751 if (zio->io_type == ZIO_TYPE_WRITE) {
3752 ASSERT(spa->spa_trust_config);
3755 * Note: the code can handle other kinds of writes,
3756 * but we don't expect them.
3758 if (zio->io_vd->vdev_removing) {
3759 ASSERT(zio->io_flags &
3760 (ZIO_FLAG_PHYSICAL | ZIO_FLAG_SELF_HEAL |
3761 ZIO_FLAG_RESILVER | ZIO_FLAG_INDUCE_DAMAGE));
3765 align = 1ULL << vd->vdev_top->vdev_ashift;
3767 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL) &&
3768 P2PHASE(zio->io_size, align) != 0) {
3769 /* Transform logical writes to be a full physical block size. */
3770 uint64_t asize = P2ROUNDUP(zio->io_size, align);
3771 abd_t *abuf = abd_alloc_sametype(zio->io_abd, asize);
3772 ASSERT(vd == vd->vdev_top);
3773 if (zio->io_type == ZIO_TYPE_WRITE) {
3774 abd_copy(abuf, zio->io_abd, zio->io_size);
3775 abd_zero_off(abuf, zio->io_size, asize - zio->io_size);
3777 zio_push_transform(zio, abuf, asize, asize, zio_subblock);
3781 * If this is not a physical io, make sure that it is properly aligned
3782 * before proceeding.
3784 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL)) {
3785 ASSERT0(P2PHASE(zio->io_offset, align));
3786 ASSERT0(P2PHASE(zio->io_size, align));
3789 * For physical writes, we allow 512b aligned writes and assume
3790 * the device will perform a read-modify-write as necessary.
3792 ASSERT0(P2PHASE(zio->io_offset, SPA_MINBLOCKSIZE));
3793 ASSERT0(P2PHASE(zio->io_size, SPA_MINBLOCKSIZE));
3796 VERIFY(zio->io_type != ZIO_TYPE_WRITE || spa_writeable(spa));
3799 * If this is a repair I/O, and there's no self-healing involved --
3800 * that is, we're just resilvering what we expect to resilver --
3801 * then don't do the I/O unless zio's txg is actually in vd's DTL.
3802 * This prevents spurious resilvering.
3804 * There are a few ways that we can end up creating these spurious
3807 * 1. A resilver i/o will be issued if any DVA in the BP has a
3808 * dirty DTL. The mirror code will issue resilver writes to
3809 * each DVA, including the one(s) that are not on vdevs with dirty
3812 * 2. With nested replication, which happens when we have a
3813 * "replacing" or "spare" vdev that's a child of a mirror or raidz.
3814 * For example, given mirror(replacing(A+B), C), it's likely that
3815 * only A is out of date (it's the new device). In this case, we'll
3816 * read from C, then use the data to resilver A+B -- but we don't
3817 * actually want to resilver B, just A. The top-level mirror has no
3818 * way to know this, so instead we just discard unnecessary repairs
3819 * as we work our way down the vdev tree.
3821 * 3. ZTEST also creates mirrors of mirrors, mirrors of raidz, etc.
3822 * The same logic applies to any form of nested replication: ditto
3823 * + mirror, RAID-Z + replacing, etc.
3825 * However, indirect vdevs point off to other vdevs which may have
3826 * DTL's, so we never bypass them. The child i/os on concrete vdevs
3827 * will be properly bypassed instead.
3829 * Leaf DTL_PARTIAL can be empty when a legitimate write comes from
3830 * a dRAID spare vdev. For example, when a dRAID spare is first
3831 * used, its spare blocks need to be written to but the leaf vdev's
3832 * of such blocks can have empty DTL_PARTIAL.
3834 * There seemed no clean way to allow such writes while bypassing
3835 * spurious ones. At this point, just avoid all bypassing for dRAID
3838 if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) &&
3839 !(zio->io_flags & ZIO_FLAG_SELF_HEAL) &&
3840 zio->io_txg != 0 && /* not a delegated i/o */
3841 vd->vdev_ops != &vdev_indirect_ops &&
3842 vd->vdev_top->vdev_ops != &vdev_draid_ops &&
3843 !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) {
3844 ASSERT(zio->io_type == ZIO_TYPE_WRITE);
3845 zio_vdev_io_bypass(zio);
3850 * Select the next best leaf I/O to process. Distributed spares are
3851 * excluded since they dispatch the I/O directly to a leaf vdev after
3852 * applying the dRAID mapping.
3854 if (vd->vdev_ops->vdev_op_leaf &&
3855 vd->vdev_ops != &vdev_draid_spare_ops &&
3856 (zio->io_type == ZIO_TYPE_READ ||
3857 zio->io_type == ZIO_TYPE_WRITE ||
3858 zio->io_type == ZIO_TYPE_TRIM)) {
3860 if (zio->io_type == ZIO_TYPE_READ && vdev_cache_read(zio))
3863 if ((zio = vdev_queue_io(zio)) == NULL)
3866 if (!vdev_accessible(vd, zio)) {
3867 zio->io_error = SET_ERROR(ENXIO);
3871 zio->io_delay = gethrtime();
3874 vd->vdev_ops->vdev_op_io_start(zio);
3879 zio_vdev_io_done(zio_t *zio)
3881 vdev_t *vd = zio->io_vd;
3882 vdev_ops_t *ops = vd ? vd->vdev_ops : &vdev_mirror_ops;
3883 boolean_t unexpected_error = B_FALSE;
3885 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV_BIT, ZIO_WAIT_DONE)) {
3889 ASSERT(zio->io_type == ZIO_TYPE_READ ||
3890 zio->io_type == ZIO_TYPE_WRITE || zio->io_type == ZIO_TYPE_TRIM);
3893 zio->io_delay = gethrtime() - zio->io_delay;
3895 if (vd != NULL && vd->vdev_ops->vdev_op_leaf &&
3896 vd->vdev_ops != &vdev_draid_spare_ops) {
3897 vdev_queue_io_done(zio);
3899 if (zio->io_type == ZIO_TYPE_WRITE)
3900 vdev_cache_write(zio);
3902 if (zio_injection_enabled && zio->io_error == 0)
3903 zio->io_error = zio_handle_device_injections(vd, zio,
3906 if (zio_injection_enabled && zio->io_error == 0)
3907 zio->io_error = zio_handle_label_injection(zio, EIO);
3909 if (zio->io_error && zio->io_type != ZIO_TYPE_TRIM) {
3910 if (!vdev_accessible(vd, zio)) {
3911 zio->io_error = SET_ERROR(ENXIO);
3913 unexpected_error = B_TRUE;
3918 ops->vdev_op_io_done(zio);
3920 if (unexpected_error)
3921 VERIFY(vdev_probe(vd, zio) == NULL);
3927 * This function is used to change the priority of an existing zio that is
3928 * currently in-flight. This is used by the arc to upgrade priority in the
3929 * event that a demand read is made for a block that is currently queued
3930 * as a scrub or async read IO. Otherwise, the high priority read request
3931 * would end up having to wait for the lower priority IO.
3934 zio_change_priority(zio_t *pio, zio_priority_t priority)
3936 zio_t *cio, *cio_next;
3937 zio_link_t *zl = NULL;
3939 ASSERT3U(priority, <, ZIO_PRIORITY_NUM_QUEUEABLE);
3941 if (pio->io_vd != NULL && pio->io_vd->vdev_ops->vdev_op_leaf) {
3942 vdev_queue_change_io_priority(pio, priority);
3944 pio->io_priority = priority;
3947 mutex_enter(&pio->io_lock);
3948 for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) {
3949 cio_next = zio_walk_children(pio, &zl);
3950 zio_change_priority(cio, priority);
3952 mutex_exit(&pio->io_lock);
3956 * For non-raidz ZIOs, we can just copy aside the bad data read from the
3957 * disk, and use that to finish the checksum ereport later.
3960 zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr,
3961 const abd_t *good_buf)
3963 /* no processing needed */
3964 zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE);
3969 zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr)
3971 void *abd = abd_alloc_sametype(zio->io_abd, zio->io_size);
3973 abd_copy(abd, zio->io_abd, zio->io_size);
3975 zcr->zcr_cbinfo = zio->io_size;
3976 zcr->zcr_cbdata = abd;
3977 zcr->zcr_finish = zio_vsd_default_cksum_finish;
3978 zcr->zcr_free = zio_abd_free;
3982 zio_vdev_io_assess(zio_t *zio)
3984 vdev_t *vd = zio->io_vd;
3986 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV_BIT, ZIO_WAIT_DONE)) {
3990 if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER))
3991 spa_config_exit(zio->io_spa, SCL_ZIO, zio);
3993 if (zio->io_vsd != NULL) {
3994 zio->io_vsd_ops->vsd_free(zio);
3998 if (zio_injection_enabled && zio->io_error == 0)
3999 zio->io_error = zio_handle_fault_injection(zio, EIO);
4002 * If the I/O failed, determine whether we should attempt to retry it.
4004 * On retry, we cut in line in the issue queue, since we don't want
4005 * compression/checksumming/etc. work to prevent our (cheap) IO reissue.
4007 if (zio->io_error && vd == NULL &&
4008 !(zio->io_flags & (ZIO_FLAG_DONT_RETRY | ZIO_FLAG_IO_RETRY))) {
4009 ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_QUEUE)); /* not a leaf */
4010 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_BYPASS)); /* not a leaf */
4012 zio->io_flags |= ZIO_FLAG_IO_RETRY |
4013 ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE;
4014 zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1;
4015 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE,
4016 zio_requeue_io_start_cut_in_line);
4021 * If we got an error on a leaf device, convert it to ENXIO
4022 * if the device is not accessible at all.
4024 if (zio->io_error && vd != NULL && vd->vdev_ops->vdev_op_leaf &&
4025 !vdev_accessible(vd, zio))
4026 zio->io_error = SET_ERROR(ENXIO);
4029 * If we can't write to an interior vdev (mirror or RAID-Z),
4030 * set vdev_cant_write so that we stop trying to allocate from it.
4032 if (zio->io_error == ENXIO && zio->io_type == ZIO_TYPE_WRITE &&
4033 vd != NULL && !vd->vdev_ops->vdev_op_leaf) {
4034 vdev_dbgmsg(vd, "zio_vdev_io_assess(zio=%px) setting "
4035 "cant_write=TRUE due to write failure with ENXIO",
4037 vd->vdev_cant_write = B_TRUE;
4041 * If a cache flush returns ENOTSUP or ENOTTY, we know that no future
4042 * attempts will ever succeed. In this case we set a persistent
4043 * boolean flag so that we don't bother with it in the future.
4045 if ((zio->io_error == ENOTSUP || zio->io_error == ENOTTY) &&
4046 zio->io_type == ZIO_TYPE_IOCTL &&
4047 zio->io_cmd == DKIOCFLUSHWRITECACHE && vd != NULL)
4048 vd->vdev_nowritecache = B_TRUE;
4051 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
4053 if (vd != NULL && vd->vdev_ops->vdev_op_leaf &&
4054 zio->io_physdone != NULL) {
4055 ASSERT(!(zio->io_flags & ZIO_FLAG_DELEGATED));
4056 ASSERT(zio->io_child_type == ZIO_CHILD_VDEV);
4057 zio->io_physdone(zio->io_logical);
4064 zio_vdev_io_reissue(zio_t *zio)
4066 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START);
4067 ASSERT(zio->io_error == 0);
4069 zio->io_stage >>= 1;
4073 zio_vdev_io_redone(zio_t *zio)
4075 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE);
4077 zio->io_stage >>= 1;
4081 zio_vdev_io_bypass(zio_t *zio)
4083 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START);
4084 ASSERT(zio->io_error == 0);
4086 zio->io_flags |= ZIO_FLAG_IO_BYPASS;
4087 zio->io_stage = ZIO_STAGE_VDEV_IO_ASSESS >> 1;
4091 * ==========================================================================
4092 * Encrypt and store encryption parameters
4093 * ==========================================================================
4098 * This function is used for ZIO_STAGE_ENCRYPT. It is responsible for
4099 * managing the storage of encryption parameters and passing them to the
4100 * lower-level encryption functions.
4103 zio_encrypt(zio_t *zio)
4105 zio_prop_t *zp = &zio->io_prop;
4106 spa_t *spa = zio->io_spa;
4107 blkptr_t *bp = zio->io_bp;
4108 uint64_t psize = BP_GET_PSIZE(bp);
4109 uint64_t dsobj = zio->io_bookmark.zb_objset;
4110 dmu_object_type_t ot = BP_GET_TYPE(bp);
4111 void *enc_buf = NULL;
4113 uint8_t salt[ZIO_DATA_SALT_LEN];
4114 uint8_t iv[ZIO_DATA_IV_LEN];
4115 uint8_t mac[ZIO_DATA_MAC_LEN];
4116 boolean_t no_crypt = B_FALSE;
4118 /* the root zio already encrypted the data */
4119 if (zio->io_child_type == ZIO_CHILD_GANG)
4122 /* only ZIL blocks are re-encrypted on rewrite */
4123 if (!IO_IS_ALLOCATING(zio) && ot != DMU_OT_INTENT_LOG)
4126 if (!(zp->zp_encrypt || BP_IS_ENCRYPTED(bp))) {
4127 BP_SET_CRYPT(bp, B_FALSE);
4131 /* if we are doing raw encryption set the provided encryption params */
4132 if (zio->io_flags & ZIO_FLAG_RAW_ENCRYPT) {
4133 ASSERT0(BP_GET_LEVEL(bp));
4134 BP_SET_CRYPT(bp, B_TRUE);
4135 BP_SET_BYTEORDER(bp, zp->zp_byteorder);
4136 if (ot != DMU_OT_OBJSET)
4137 zio_crypt_encode_mac_bp(bp, zp->zp_mac);
4139 /* dnode blocks must be written out in the provided byteorder */
4140 if (zp->zp_byteorder != ZFS_HOST_BYTEORDER &&
4141 ot == DMU_OT_DNODE) {
4142 void *bswap_buf = zio_buf_alloc(psize);
4143 abd_t *babd = abd_get_from_buf(bswap_buf, psize);
4145 ASSERT3U(BP_GET_COMPRESS(bp), ==, ZIO_COMPRESS_OFF);
4146 abd_copy_to_buf(bswap_buf, zio->io_abd, psize);
4147 dmu_ot_byteswap[DMU_OT_BYTESWAP(ot)].ob_func(bswap_buf,
4150 abd_take_ownership_of_buf(babd, B_TRUE);
4151 zio_push_transform(zio, babd, psize, psize, NULL);
4154 if (DMU_OT_IS_ENCRYPTED(ot))
4155 zio_crypt_encode_params_bp(bp, zp->zp_salt, zp->zp_iv);
4159 /* indirect blocks only maintain a cksum of the lower level MACs */
4160 if (BP_GET_LEVEL(bp) > 0) {
4161 BP_SET_CRYPT(bp, B_TRUE);
4162 VERIFY0(zio_crypt_do_indirect_mac_checksum_abd(B_TRUE,
4163 zio->io_orig_abd, BP_GET_LSIZE(bp), BP_SHOULD_BYTESWAP(bp),
4165 zio_crypt_encode_mac_bp(bp, mac);
4170 * Objset blocks are a special case since they have 2 256-bit MACs
4171 * embedded within them.
4173 if (ot == DMU_OT_OBJSET) {
4174 ASSERT0(DMU_OT_IS_ENCRYPTED(ot));
4175 ASSERT3U(BP_GET_COMPRESS(bp), ==, ZIO_COMPRESS_OFF);
4176 BP_SET_CRYPT(bp, B_TRUE);
4177 VERIFY0(spa_do_crypt_objset_mac_abd(B_TRUE, spa, dsobj,
4178 zio->io_abd, psize, BP_SHOULD_BYTESWAP(bp)));
4182 /* unencrypted object types are only authenticated with a MAC */
4183 if (!DMU_OT_IS_ENCRYPTED(ot)) {
4184 BP_SET_CRYPT(bp, B_TRUE);
4185 VERIFY0(spa_do_crypt_mac_abd(B_TRUE, spa, dsobj,
4186 zio->io_abd, psize, mac));
4187 zio_crypt_encode_mac_bp(bp, mac);
4192 * Later passes of sync-to-convergence may decide to rewrite data
4193 * in place to avoid more disk reallocations. This presents a problem
4194 * for encryption because this constitutes rewriting the new data with
4195 * the same encryption key and IV. However, this only applies to blocks
4196 * in the MOS (particularly the spacemaps) and we do not encrypt the
4197 * MOS. We assert that the zio is allocating or an intent log write
4200 ASSERT(IO_IS_ALLOCATING(zio) || ot == DMU_OT_INTENT_LOG);
4201 ASSERT(BP_GET_LEVEL(bp) == 0 || ot == DMU_OT_INTENT_LOG);
4202 ASSERT(spa_feature_is_active(spa, SPA_FEATURE_ENCRYPTION));
4203 ASSERT3U(psize, !=, 0);
4205 enc_buf = zio_buf_alloc(psize);
4206 eabd = abd_get_from_buf(enc_buf, psize);
4207 abd_take_ownership_of_buf(eabd, B_TRUE);
4210 * For an explanation of what encryption parameters are stored
4211 * where, see the block comment in zio_crypt.c.
4213 if (ot == DMU_OT_INTENT_LOG) {
4214 zio_crypt_decode_params_bp(bp, salt, iv);
4216 BP_SET_CRYPT(bp, B_TRUE);
4219 /* Perform the encryption. This should not fail */
4220 VERIFY0(spa_do_crypt_abd(B_TRUE, spa, &zio->io_bookmark,
4221 BP_GET_TYPE(bp), BP_GET_DEDUP(bp), BP_SHOULD_BYTESWAP(bp),
4222 salt, iv, mac, psize, zio->io_abd, eabd, &no_crypt));
4224 /* encode encryption metadata into the bp */
4225 if (ot == DMU_OT_INTENT_LOG) {
4227 * ZIL blocks store the MAC in the embedded checksum, so the
4228 * transform must always be applied.
4230 zio_crypt_encode_mac_zil(enc_buf, mac);
4231 zio_push_transform(zio, eabd, psize, psize, NULL);
4233 BP_SET_CRYPT(bp, B_TRUE);
4234 zio_crypt_encode_params_bp(bp, salt, iv);
4235 zio_crypt_encode_mac_bp(bp, mac);
4238 ASSERT3U(ot, ==, DMU_OT_DNODE);
4241 zio_push_transform(zio, eabd, psize, psize, NULL);
4249 * ==========================================================================
4250 * Generate and verify checksums
4251 * ==========================================================================
4254 zio_checksum_generate(zio_t *zio)
4256 blkptr_t *bp = zio->io_bp;
4257 enum zio_checksum checksum;
4261 * This is zio_write_phys().
4262 * We're either generating a label checksum, or none at all.
4264 checksum = zio->io_prop.zp_checksum;
4266 if (checksum == ZIO_CHECKSUM_OFF)
4269 ASSERT(checksum == ZIO_CHECKSUM_LABEL);
4271 if (BP_IS_GANG(bp) && zio->io_child_type == ZIO_CHILD_GANG) {
4272 ASSERT(!IO_IS_ALLOCATING(zio));
4273 checksum = ZIO_CHECKSUM_GANG_HEADER;
4275 checksum = BP_GET_CHECKSUM(bp);
4279 zio_checksum_compute(zio, checksum, zio->io_abd, zio->io_size);
4285 zio_checksum_verify(zio_t *zio)
4287 zio_bad_cksum_t info;
4288 blkptr_t *bp = zio->io_bp;
4291 ASSERT(zio->io_vd != NULL);
4295 * This is zio_read_phys().
4296 * We're either verifying a label checksum, or nothing at all.
4298 if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF)
4301 ASSERT3U(zio->io_prop.zp_checksum, ==, ZIO_CHECKSUM_LABEL);
4304 if ((error = zio_checksum_error(zio, &info)) != 0) {
4305 zio->io_error = error;
4306 if (error == ECKSUM &&
4307 !(zio->io_flags & ZIO_FLAG_SPECULATIVE)) {
4308 (void) zfs_ereport_start_checksum(zio->io_spa,
4309 zio->io_vd, &zio->io_bookmark, zio,
4310 zio->io_offset, zio->io_size, &info);
4311 mutex_enter(&zio->io_vd->vdev_stat_lock);
4312 zio->io_vd->vdev_stat.vs_checksum_errors++;
4313 mutex_exit(&zio->io_vd->vdev_stat_lock);
4321 * Called by RAID-Z to ensure we don't compute the checksum twice.
4324 zio_checksum_verified(zio_t *zio)
4326 zio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY;
4330 * ==========================================================================
4331 * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other.
4332 * An error of 0 indicates success. ENXIO indicates whole-device failure,
4333 * which may be transient (e.g. unplugged) or permanent. ECKSUM and EIO
4334 * indicate errors that are specific to one I/O, and most likely permanent.
4335 * Any other error is presumed to be worse because we weren't expecting it.
4336 * ==========================================================================
4339 zio_worst_error(int e1, int e2)
4341 static int zio_error_rank[] = { 0, ENXIO, ECKSUM, EIO };
4344 for (r1 = 0; r1 < sizeof (zio_error_rank) / sizeof (int); r1++)
4345 if (e1 == zio_error_rank[r1])
4348 for (r2 = 0; r2 < sizeof (zio_error_rank) / sizeof (int); r2++)
4349 if (e2 == zio_error_rank[r2])
4352 return (r1 > r2 ? e1 : e2);
4356 * ==========================================================================
4358 * ==========================================================================
4361 zio_ready(zio_t *zio)
4363 blkptr_t *bp = zio->io_bp;
4364 zio_t *pio, *pio_next;
4365 zio_link_t *zl = NULL;
4367 if (zio_wait_for_children(zio, ZIO_CHILD_GANG_BIT | ZIO_CHILD_DDT_BIT,
4372 if (zio->io_ready) {
4373 ASSERT(IO_IS_ALLOCATING(zio));
4374 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp) ||
4375 (zio->io_flags & ZIO_FLAG_NOPWRITE));
4376 ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0);
4381 if (bp != NULL && bp != &zio->io_bp_copy)
4382 zio->io_bp_copy = *bp;
4384 if (zio->io_error != 0) {
4385 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
4387 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING) {
4388 ASSERT(IO_IS_ALLOCATING(zio));
4389 ASSERT(zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE);
4390 ASSERT(zio->io_metaslab_class != NULL);
4393 * We were unable to allocate anything, unreserve and
4394 * issue the next I/O to allocate.
4396 metaslab_class_throttle_unreserve(
4397 zio->io_metaslab_class, zio->io_prop.zp_copies,
4398 zio->io_allocator, zio);
4399 zio_allocate_dispatch(zio->io_spa, zio->io_allocator);
4403 mutex_enter(&zio->io_lock);
4404 zio->io_state[ZIO_WAIT_READY] = 1;
4405 pio = zio_walk_parents(zio, &zl);
4406 mutex_exit(&zio->io_lock);
4409 * As we notify zio's parents, new parents could be added.
4410 * New parents go to the head of zio's io_parent_list, however,
4411 * so we will (correctly) not notify them. The remainder of zio's
4412 * io_parent_list, from 'pio_next' onward, cannot change because
4413 * all parents must wait for us to be done before they can be done.
4415 for (; pio != NULL; pio = pio_next) {
4416 pio_next = zio_walk_parents(zio, &zl);
4417 zio_notify_parent(pio, zio, ZIO_WAIT_READY, NULL);
4420 if (zio->io_flags & ZIO_FLAG_NODATA) {
4421 if (BP_IS_GANG(bp)) {
4422 zio->io_flags &= ~ZIO_FLAG_NODATA;
4424 ASSERT((uintptr_t)zio->io_abd < SPA_MAXBLOCKSIZE);
4425 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES;
4429 if (zio_injection_enabled &&
4430 zio->io_spa->spa_syncing_txg == zio->io_txg)
4431 zio_handle_ignored_writes(zio);
4437 * Update the allocation throttle accounting.
4440 zio_dva_throttle_done(zio_t *zio)
4442 zio_t *lio __maybe_unused = zio->io_logical;
4443 zio_t *pio = zio_unique_parent(zio);
4444 vdev_t *vd = zio->io_vd;
4445 int flags = METASLAB_ASYNC_ALLOC;
4447 ASSERT3P(zio->io_bp, !=, NULL);
4448 ASSERT3U(zio->io_type, ==, ZIO_TYPE_WRITE);
4449 ASSERT3U(zio->io_priority, ==, ZIO_PRIORITY_ASYNC_WRITE);
4450 ASSERT3U(zio->io_child_type, ==, ZIO_CHILD_VDEV);
4452 ASSERT3P(vd, ==, vd->vdev_top);
4453 ASSERT(zio_injection_enabled || !(zio->io_flags & ZIO_FLAG_IO_RETRY));
4454 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REPAIR));
4455 ASSERT(zio->io_flags & ZIO_FLAG_IO_ALLOCATING);
4456 ASSERT(!(lio->io_flags & ZIO_FLAG_IO_REWRITE));
4457 ASSERT(!(lio->io_orig_flags & ZIO_FLAG_NODATA));
4460 * Parents of gang children can have two flavors -- ones that
4461 * allocated the gang header (will have ZIO_FLAG_IO_REWRITE set)
4462 * and ones that allocated the constituent blocks. The allocation
4463 * throttle needs to know the allocating parent zio so we must find
4466 if (pio->io_child_type == ZIO_CHILD_GANG) {
4468 * If our parent is a rewrite gang child then our grandparent
4469 * would have been the one that performed the allocation.
4471 if (pio->io_flags & ZIO_FLAG_IO_REWRITE)
4472 pio = zio_unique_parent(pio);
4473 flags |= METASLAB_GANG_CHILD;
4476 ASSERT(IO_IS_ALLOCATING(pio));
4477 ASSERT3P(zio, !=, zio->io_logical);
4478 ASSERT(zio->io_logical != NULL);
4479 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REPAIR));
4480 ASSERT0(zio->io_flags & ZIO_FLAG_NOPWRITE);
4481 ASSERT(zio->io_metaslab_class != NULL);
4483 mutex_enter(&pio->io_lock);
4484 metaslab_group_alloc_decrement(zio->io_spa, vd->vdev_id, pio, flags,
4485 pio->io_allocator, B_TRUE);
4486 mutex_exit(&pio->io_lock);
4488 metaslab_class_throttle_unreserve(zio->io_metaslab_class, 1,
4489 pio->io_allocator, pio);
4492 * Call into the pipeline to see if there is more work that
4493 * needs to be done. If there is work to be done it will be
4494 * dispatched to another taskq thread.
4496 zio_allocate_dispatch(zio->io_spa, pio->io_allocator);
4500 zio_done(zio_t *zio)
4503 * Always attempt to keep stack usage minimal here since
4504 * we can be called recursively up to 19 levels deep.
4506 const uint64_t psize = zio->io_size;
4507 zio_t *pio, *pio_next;
4508 zio_link_t *zl = NULL;
4511 * If our children haven't all completed,
4512 * wait for them and then repeat this pipeline stage.
4514 if (zio_wait_for_children(zio, ZIO_CHILD_ALL_BITS, ZIO_WAIT_DONE)) {
4519 * If the allocation throttle is enabled, then update the accounting.
4520 * We only track child I/Os that are part of an allocating async
4521 * write. We must do this since the allocation is performed
4522 * by the logical I/O but the actual write is done by child I/Os.
4524 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING &&
4525 zio->io_child_type == ZIO_CHILD_VDEV) {
4526 ASSERT(zio->io_metaslab_class != NULL);
4527 ASSERT(zio->io_metaslab_class->mc_alloc_throttle_enabled);
4528 zio_dva_throttle_done(zio);
4532 * If the allocation throttle is enabled, verify that
4533 * we have decremented the refcounts for every I/O that was throttled.
4535 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING) {
4536 ASSERT(zio->io_type == ZIO_TYPE_WRITE);
4537 ASSERT(zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE);
4538 ASSERT(zio->io_bp != NULL);
4540 metaslab_group_alloc_verify(zio->io_spa, zio->io_bp, zio,
4542 VERIFY(zfs_refcount_not_held(&zio->io_metaslab_class->
4543 mc_allocator[zio->io_allocator].mca_alloc_slots, zio));
4547 for (int c = 0; c < ZIO_CHILD_TYPES; c++)
4548 for (int w = 0; w < ZIO_WAIT_TYPES; w++)
4549 ASSERT(zio->io_children[c][w] == 0);
4551 if (zio->io_bp != NULL && !BP_IS_EMBEDDED(zio->io_bp)) {
4552 ASSERT(zio->io_bp->blk_pad[0] == 0);
4553 ASSERT(zio->io_bp->blk_pad[1] == 0);
4554 ASSERT(bcmp(zio->io_bp, &zio->io_bp_copy,
4555 sizeof (blkptr_t)) == 0 ||
4556 (zio->io_bp == zio_unique_parent(zio)->io_bp));
4557 if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(zio->io_bp) &&
4558 zio->io_bp_override == NULL &&
4559 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) {
4560 ASSERT3U(zio->io_prop.zp_copies, <=,
4561 BP_GET_NDVAS(zio->io_bp));
4562 ASSERT(BP_COUNT_GANG(zio->io_bp) == 0 ||
4563 (BP_COUNT_GANG(zio->io_bp) ==
4564 BP_GET_NDVAS(zio->io_bp)));
4566 if (zio->io_flags & ZIO_FLAG_NOPWRITE)
4567 VERIFY(BP_EQUAL(zio->io_bp, &zio->io_bp_orig));
4571 * If there were child vdev/gang/ddt errors, they apply to us now.
4573 zio_inherit_child_errors(zio, ZIO_CHILD_VDEV);
4574 zio_inherit_child_errors(zio, ZIO_CHILD_GANG);
4575 zio_inherit_child_errors(zio, ZIO_CHILD_DDT);
4578 * If the I/O on the transformed data was successful, generate any
4579 * checksum reports now while we still have the transformed data.
4581 if (zio->io_error == 0) {
4582 while (zio->io_cksum_report != NULL) {
4583 zio_cksum_report_t *zcr = zio->io_cksum_report;
4584 uint64_t align = zcr->zcr_align;
4585 uint64_t asize = P2ROUNDUP(psize, align);
4586 abd_t *adata = zio->io_abd;
4588 if (adata != NULL && asize != psize) {
4589 adata = abd_alloc(asize, B_TRUE);
4590 abd_copy(adata, zio->io_abd, psize);
4591 abd_zero_off(adata, psize, asize - psize);
4594 zio->io_cksum_report = zcr->zcr_next;
4595 zcr->zcr_next = NULL;
4596 zcr->zcr_finish(zcr, adata);
4597 zfs_ereport_free_checksum(zcr);
4599 if (adata != NULL && asize != psize)
4604 zio_pop_transforms(zio); /* note: may set zio->io_error */
4606 vdev_stat_update(zio, psize);
4609 * If this I/O is attached to a particular vdev is slow, exceeding
4610 * 30 seconds to complete, post an error described the I/O delay.
4611 * We ignore these errors if the device is currently unavailable.
4613 if (zio->io_delay >= MSEC2NSEC(zio_slow_io_ms)) {
4614 if (zio->io_vd != NULL && !vdev_is_dead(zio->io_vd)) {
4616 * We want to only increment our slow IO counters if
4617 * the IO is valid (i.e. not if the drive is removed).
4619 * zfs_ereport_post() will also do these checks, but
4620 * it can also ratelimit and have other failures, so we
4621 * need to increment the slow_io counters independent
4624 if (zfs_ereport_is_valid(FM_EREPORT_ZFS_DELAY,
4625 zio->io_spa, zio->io_vd, zio)) {
4626 mutex_enter(&zio->io_vd->vdev_stat_lock);
4627 zio->io_vd->vdev_stat.vs_slow_ios++;
4628 mutex_exit(&zio->io_vd->vdev_stat_lock);
4630 (void) zfs_ereport_post(FM_EREPORT_ZFS_DELAY,
4631 zio->io_spa, zio->io_vd, &zio->io_bookmark,
4637 if (zio->io_error) {
4639 * If this I/O is attached to a particular vdev,
4640 * generate an error message describing the I/O failure
4641 * at the block level. We ignore these errors if the
4642 * device is currently unavailable.
4644 if (zio->io_error != ECKSUM && zio->io_vd != NULL &&
4645 !vdev_is_dead(zio->io_vd)) {
4646 int ret = zfs_ereport_post(FM_EREPORT_ZFS_IO,
4647 zio->io_spa, zio->io_vd, &zio->io_bookmark, zio, 0);
4648 if (ret != EALREADY) {
4649 mutex_enter(&zio->io_vd->vdev_stat_lock);
4650 if (zio->io_type == ZIO_TYPE_READ)
4651 zio->io_vd->vdev_stat.vs_read_errors++;
4652 else if (zio->io_type == ZIO_TYPE_WRITE)
4653 zio->io_vd->vdev_stat.vs_write_errors++;
4654 mutex_exit(&zio->io_vd->vdev_stat_lock);
4658 if ((zio->io_error == EIO || !(zio->io_flags &
4659 (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) &&
4660 zio == zio->io_logical) {
4662 * For logical I/O requests, tell the SPA to log the
4663 * error and generate a logical data ereport.
4665 spa_log_error(zio->io_spa, &zio->io_bookmark);
4666 (void) zfs_ereport_post(FM_EREPORT_ZFS_DATA,
4667 zio->io_spa, NULL, &zio->io_bookmark, zio, 0);
4671 if (zio->io_error && zio == zio->io_logical) {
4673 * Determine whether zio should be reexecuted. This will
4674 * propagate all the way to the root via zio_notify_parent().
4676 ASSERT(zio->io_vd == NULL && zio->io_bp != NULL);
4677 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
4679 if (IO_IS_ALLOCATING(zio) &&
4680 !(zio->io_flags & ZIO_FLAG_CANFAIL)) {
4681 if (zio->io_error != ENOSPC)
4682 zio->io_reexecute |= ZIO_REEXECUTE_NOW;
4684 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND;
4687 if ((zio->io_type == ZIO_TYPE_READ ||
4688 zio->io_type == ZIO_TYPE_FREE) &&
4689 !(zio->io_flags & ZIO_FLAG_SCAN_THREAD) &&
4690 zio->io_error == ENXIO &&
4691 spa_load_state(zio->io_spa) == SPA_LOAD_NONE &&
4692 spa_get_failmode(zio->io_spa) != ZIO_FAILURE_MODE_CONTINUE)
4693 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND;
4695 if (!(zio->io_flags & ZIO_FLAG_CANFAIL) && !zio->io_reexecute)
4696 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND;
4699 * Here is a possibly good place to attempt to do
4700 * either combinatorial reconstruction or error correction
4701 * based on checksums. It also might be a good place
4702 * to send out preliminary ereports before we suspend
4708 * If there were logical child errors, they apply to us now.
4709 * We defer this until now to avoid conflating logical child
4710 * errors with errors that happened to the zio itself when
4711 * updating vdev stats and reporting FMA events above.
4713 zio_inherit_child_errors(zio, ZIO_CHILD_LOGICAL);
4715 if ((zio->io_error || zio->io_reexecute) &&
4716 IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio &&
4717 !(zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE)))
4718 zio_dva_unallocate(zio, zio->io_gang_tree, zio->io_bp);
4720 zio_gang_tree_free(&zio->io_gang_tree);
4723 * Godfather I/Os should never suspend.
4725 if ((zio->io_flags & ZIO_FLAG_GODFATHER) &&
4726 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND))
4727 zio->io_reexecute &= ~ZIO_REEXECUTE_SUSPEND;
4729 if (zio->io_reexecute) {
4731 * This is a logical I/O that wants to reexecute.
4733 * Reexecute is top-down. When an i/o fails, if it's not
4734 * the root, it simply notifies its parent and sticks around.
4735 * The parent, seeing that it still has children in zio_done(),
4736 * does the same. This percolates all the way up to the root.
4737 * The root i/o will reexecute or suspend the entire tree.
4739 * This approach ensures that zio_reexecute() honors
4740 * all the original i/o dependency relationships, e.g.
4741 * parents not executing until children are ready.
4743 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
4745 zio->io_gang_leader = NULL;
4747 mutex_enter(&zio->io_lock);
4748 zio->io_state[ZIO_WAIT_DONE] = 1;
4749 mutex_exit(&zio->io_lock);
4752 * "The Godfather" I/O monitors its children but is
4753 * not a true parent to them. It will track them through
4754 * the pipeline but severs its ties whenever they get into
4755 * trouble (e.g. suspended). This allows "The Godfather"
4756 * I/O to return status without blocking.
4759 for (pio = zio_walk_parents(zio, &zl); pio != NULL;
4761 zio_link_t *remove_zl = zl;
4762 pio_next = zio_walk_parents(zio, &zl);
4764 if ((pio->io_flags & ZIO_FLAG_GODFATHER) &&
4765 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) {
4766 zio_remove_child(pio, zio, remove_zl);
4768 * This is a rare code path, so we don't
4769 * bother with "next_to_execute".
4771 zio_notify_parent(pio, zio, ZIO_WAIT_DONE,
4776 if ((pio = zio_unique_parent(zio)) != NULL) {
4778 * We're not a root i/o, so there's nothing to do
4779 * but notify our parent. Don't propagate errors
4780 * upward since we haven't permanently failed yet.
4782 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER));
4783 zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE;
4785 * This is a rare code path, so we don't bother with
4786 * "next_to_execute".
4788 zio_notify_parent(pio, zio, ZIO_WAIT_DONE, NULL);
4789 } else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) {
4791 * We'd fail again if we reexecuted now, so suspend
4792 * until conditions improve (e.g. device comes online).
4794 zio_suspend(zio->io_spa, zio, ZIO_SUSPEND_IOERR);
4797 * Reexecution is potentially a huge amount of work.
4798 * Hand it off to the otherwise-unused claim taskq.
4800 ASSERT(taskq_empty_ent(&zio->io_tqent));
4801 spa_taskq_dispatch_ent(zio->io_spa,
4802 ZIO_TYPE_CLAIM, ZIO_TASKQ_ISSUE,
4803 zio_reexecute, zio, 0, &zio->io_tqent);
4808 ASSERT(zio->io_child_count == 0);
4809 ASSERT(zio->io_reexecute == 0);
4810 ASSERT(zio->io_error == 0 || (zio->io_flags & ZIO_FLAG_CANFAIL));
4813 * Report any checksum errors, since the I/O is complete.
4815 while (zio->io_cksum_report != NULL) {
4816 zio_cksum_report_t *zcr = zio->io_cksum_report;
4817 zio->io_cksum_report = zcr->zcr_next;
4818 zcr->zcr_next = NULL;
4819 zcr->zcr_finish(zcr, NULL);
4820 zfs_ereport_free_checksum(zcr);
4823 if (zio->io_flags & ZIO_FLAG_FASTWRITE && zio->io_bp &&
4824 !BP_IS_HOLE(zio->io_bp) && !BP_IS_EMBEDDED(zio->io_bp) &&
4825 !(zio->io_flags & ZIO_FLAG_NOPWRITE)) {
4826 metaslab_fastwrite_unmark(zio->io_spa, zio->io_bp);
4830 * It is the responsibility of the done callback to ensure that this
4831 * particular zio is no longer discoverable for adoption, and as
4832 * such, cannot acquire any new parents.
4837 mutex_enter(&zio->io_lock);
4838 zio->io_state[ZIO_WAIT_DONE] = 1;
4839 mutex_exit(&zio->io_lock);
4842 * We are done executing this zio. We may want to execute a parent
4843 * next. See the comment in zio_notify_parent().
4845 zio_t *next_to_execute = NULL;
4847 for (pio = zio_walk_parents(zio, &zl); pio != NULL; pio = pio_next) {
4848 zio_link_t *remove_zl = zl;
4849 pio_next = zio_walk_parents(zio, &zl);
4850 zio_remove_child(pio, zio, remove_zl);
4851 zio_notify_parent(pio, zio, ZIO_WAIT_DONE, &next_to_execute);
4854 if (zio->io_waiter != NULL) {
4855 mutex_enter(&zio->io_lock);
4856 zio->io_executor = NULL;
4857 cv_broadcast(&zio->io_cv);
4858 mutex_exit(&zio->io_lock);
4863 return (next_to_execute);
4867 * ==========================================================================
4868 * I/O pipeline definition
4869 * ==========================================================================
4871 static zio_pipe_stage_t *zio_pipeline[] = {
4879 zio_checksum_generate,
4895 zio_checksum_verify,
4903 * Compare two zbookmark_phys_t's to see which we would reach first in a
4904 * pre-order traversal of the object tree.
4906 * This is simple in every case aside from the meta-dnode object. For all other
4907 * objects, we traverse them in order (object 1 before object 2, and so on).
4908 * However, all of these objects are traversed while traversing object 0, since
4909 * the data it points to is the list of objects. Thus, we need to convert to a
4910 * canonical representation so we can compare meta-dnode bookmarks to
4911 * non-meta-dnode bookmarks.
4913 * We do this by calculating "equivalents" for each field of the zbookmark.
4914 * zbookmarks outside of the meta-dnode use their own object and level, and
4915 * calculate the level 0 equivalent (the first L0 blkid that is contained in the
4916 * blocks this bookmark refers to) by multiplying their blkid by their span
4917 * (the number of L0 blocks contained within one block at their level).
4918 * zbookmarks inside the meta-dnode calculate their object equivalent
4919 * (which is L0equiv * dnodes per data block), use 0 for their L0equiv, and use
4920 * level + 1<<31 (any value larger than a level could ever be) for their level.
4921 * This causes them to always compare before a bookmark in their object
4922 * equivalent, compare appropriately to bookmarks in other objects, and to
4923 * compare appropriately to other bookmarks in the meta-dnode.
4926 zbookmark_compare(uint16_t dbss1, uint8_t ibs1, uint16_t dbss2, uint8_t ibs2,
4927 const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2)
4930 * These variables represent the "equivalent" values for the zbookmark,
4931 * after converting zbookmarks inside the meta dnode to their
4932 * normal-object equivalents.
4934 uint64_t zb1obj, zb2obj;
4935 uint64_t zb1L0, zb2L0;
4936 uint64_t zb1level, zb2level;
4938 if (zb1->zb_object == zb2->zb_object &&
4939 zb1->zb_level == zb2->zb_level &&
4940 zb1->zb_blkid == zb2->zb_blkid)
4943 IMPLY(zb1->zb_level > 0, ibs1 >= SPA_MINBLOCKSHIFT);
4944 IMPLY(zb2->zb_level > 0, ibs2 >= SPA_MINBLOCKSHIFT);
4947 * BP_SPANB calculates the span in blocks.
4949 zb1L0 = (zb1->zb_blkid) * BP_SPANB(ibs1, zb1->zb_level);
4950 zb2L0 = (zb2->zb_blkid) * BP_SPANB(ibs2, zb2->zb_level);
4952 if (zb1->zb_object == DMU_META_DNODE_OBJECT) {
4953 zb1obj = zb1L0 * (dbss1 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT));
4955 zb1level = zb1->zb_level + COMPARE_META_LEVEL;
4957 zb1obj = zb1->zb_object;
4958 zb1level = zb1->zb_level;
4961 if (zb2->zb_object == DMU_META_DNODE_OBJECT) {
4962 zb2obj = zb2L0 * (dbss2 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT));
4964 zb2level = zb2->zb_level + COMPARE_META_LEVEL;
4966 zb2obj = zb2->zb_object;
4967 zb2level = zb2->zb_level;
4970 /* Now that we have a canonical representation, do the comparison. */
4971 if (zb1obj != zb2obj)
4972 return (zb1obj < zb2obj ? -1 : 1);
4973 else if (zb1L0 != zb2L0)
4974 return (zb1L0 < zb2L0 ? -1 : 1);
4975 else if (zb1level != zb2level)
4976 return (zb1level > zb2level ? -1 : 1);
4978 * This can (theoretically) happen if the bookmarks have the same object
4979 * and level, but different blkids, if the block sizes are not the same.
4980 * There is presently no way to change the indirect block sizes
4986 * This function checks the following: given that last_block is the place that
4987 * our traversal stopped last time, does that guarantee that we've visited
4988 * every node under subtree_root? Therefore, we can't just use the raw output
4989 * of zbookmark_compare. We have to pass in a modified version of
4990 * subtree_root; by incrementing the block id, and then checking whether
4991 * last_block is before or equal to that, we can tell whether or not having
4992 * visited last_block implies that all of subtree_root's children have been
4996 zbookmark_subtree_completed(const dnode_phys_t *dnp,
4997 const zbookmark_phys_t *subtree_root, const zbookmark_phys_t *last_block)
4999 zbookmark_phys_t mod_zb = *subtree_root;
5001 ASSERT(last_block->zb_level == 0);
5003 /* The objset_phys_t isn't before anything. */
5008 * We pass in 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT) for the
5009 * data block size in sectors, because that variable is only used if
5010 * the bookmark refers to a block in the meta-dnode. Since we don't
5011 * know without examining it what object it refers to, and there's no
5012 * harm in passing in this value in other cases, we always pass it in.
5014 * We pass in 0 for the indirect block size shift because zb2 must be
5015 * level 0. The indirect block size is only used to calculate the span
5016 * of the bookmark, but since the bookmark must be level 0, the span is
5017 * always 1, so the math works out.
5019 * If you make changes to how the zbookmark_compare code works, be sure
5020 * to make sure that this code still works afterwards.
5022 return (zbookmark_compare(dnp->dn_datablkszsec, dnp->dn_indblkshift,
5023 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT), 0, &mod_zb,
5027 EXPORT_SYMBOL(zio_type_name);
5028 EXPORT_SYMBOL(zio_buf_alloc);
5029 EXPORT_SYMBOL(zio_data_buf_alloc);
5030 EXPORT_SYMBOL(zio_buf_free);
5031 EXPORT_SYMBOL(zio_data_buf_free);
5034 ZFS_MODULE_PARAM(zfs_zio, zio_, slow_io_ms, INT, ZMOD_RW,
5035 "Max I/O completion time (milliseconds) before marking it as slow");
5037 ZFS_MODULE_PARAM(zfs_zio, zio_, requeue_io_start_cut_in_line, INT, ZMOD_RW,
5038 "Prioritize requeued I/O");
5040 ZFS_MODULE_PARAM(zfs, zfs_, sync_pass_deferred_free, INT, ZMOD_RW,
5041 "Defer frees starting in this pass");
5043 ZFS_MODULE_PARAM(zfs, zfs_, sync_pass_dont_compress, INT, ZMOD_RW,
5044 "Don't compress starting in this pass");
5046 ZFS_MODULE_PARAM(zfs, zfs_, sync_pass_rewrite, INT, ZMOD_RW,
5047 "Rewrite new bps starting in this pass");
5049 ZFS_MODULE_PARAM(zfs_zio, zio_, dva_throttle_enabled, INT, ZMOD_RW,
5050 "Throttle block allocations in the ZIO pipeline");
5052 ZFS_MODULE_PARAM(zfs_zio, zio_, deadman_log_all, INT, ZMOD_RW,
5053 "Log all slow ZIOs, not just those with vdevs");