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, 2018 by Delphix. All rights reserved.
24 * Copyright (c) 2011 Nexenta Systems, Inc. All rights reserved.
25 * Copyright (c) 2014 Integros [integros.com]
28 #include <sys/sysmacros.h>
29 #include <sys/zfs_context.h>
30 #include <sys/fm/fs/zfs.h>
33 #include <sys/spa_impl.h>
34 #include <sys/vdev_impl.h>
35 #include <sys/zio_impl.h>
36 #include <sys/zio_compress.h>
37 #include <sys/zio_checksum.h>
38 #include <sys/dmu_objset.h>
41 #include <sys/blkptr.h>
42 #include <sys/zfeature.h>
43 #include <sys/metaslab_impl.h>
45 #include <sys/cityhash.h>
48 * ==========================================================================
49 * I/O type descriptions
50 * ==========================================================================
52 const char *zio_type_name
[ZIO_TYPES
] = {
53 "zio_null", "zio_read", "zio_write", "zio_free", "zio_claim",
57 boolean_t zio_dva_throttle_enabled
= B_TRUE
;
60 * ==========================================================================
62 * ==========================================================================
64 kmem_cache_t
*zio_cache
;
65 kmem_cache_t
*zio_link_cache
;
66 kmem_cache_t
*zio_buf_cache
[SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
];
67 kmem_cache_t
*zio_data_buf_cache
[SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
];
70 extern vmem_t
*zio_alloc_arena
;
73 #define ZIO_PIPELINE_CONTINUE 0x100
74 #define ZIO_PIPELINE_STOP 0x101
76 #define BP_SPANB(indblkshift, level) \
77 (((uint64_t)1) << ((level) * ((indblkshift) - SPA_BLKPTRSHIFT)))
78 #define COMPARE_META_LEVEL 0x80000000ul
80 * The following actions directly effect the spa's sync-to-convergence logic.
81 * The values below define the sync pass when we start performing the action.
82 * Care should be taken when changing these values as they directly impact
83 * spa_sync() performance. Tuning these values may introduce subtle performance
84 * pathologies and should only be done in the context of performance analysis.
85 * These tunables will eventually be removed and replaced with #defines once
86 * enough analysis has been done to determine optimal values.
88 * The 'zfs_sync_pass_deferred_free' pass must be greater than 1 to ensure that
89 * regular blocks are not deferred.
91 int zfs_sync_pass_deferred_free
= 2; /* defer frees starting in this pass */
92 int zfs_sync_pass_dont_compress
= 5; /* don't compress starting in this pass */
93 int zfs_sync_pass_rewrite
= 2; /* rewrite new bps starting in this pass */
96 * An allocating zio is one that either currently has the DVA allocate
97 * stage set or will have it later in its lifetime.
99 #define IO_IS_ALLOCATING(zio) ((zio)->io_orig_pipeline & ZIO_STAGE_DVA_ALLOCATE)
101 boolean_t zio_requeue_io_start_cut_in_line
= B_TRUE
;
104 int zio_buf_debug_limit
= 16384;
106 int zio_buf_debug_limit
= 0;
109 static void zio_taskq_dispatch(zio_t
*, zio_taskq_type_t
, boolean_t
);
115 vmem_t
*data_alloc_arena
= NULL
;
118 data_alloc_arena
= zio_alloc_arena
;
120 zio_cache
= kmem_cache_create("zio_cache",
121 sizeof (zio_t
), 0, NULL
, NULL
, NULL
, NULL
, NULL
, 0);
122 zio_link_cache
= kmem_cache_create("zio_link_cache",
123 sizeof (zio_link_t
), 0, NULL
, NULL
, NULL
, NULL
, NULL
, 0);
126 * For small buffers, we want a cache for each multiple of
127 * SPA_MINBLOCKSIZE. For larger buffers, we want a cache
128 * for each quarter-power of 2.
130 for (c
= 0; c
< SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
; c
++) {
131 size_t size
= (c
+ 1) << SPA_MINBLOCKSHIFT
;
134 size_t cflags
= (size
> zio_buf_debug_limit
) ? KMC_NODEBUG
: 0;
141 * If we are using watchpoints, put each buffer on its own page,
142 * to eliminate the performance overhead of trapping to the
143 * kernel when modifying a non-watched buffer that shares the
144 * page with a watched buffer.
146 if (arc_watch
&& !IS_P2ALIGNED(size
, PAGESIZE
))
149 if (size
<= 4 * SPA_MINBLOCKSIZE
) {
150 align
= SPA_MINBLOCKSIZE
;
151 } else if (IS_P2ALIGNED(size
, p2
>> 2)) {
152 align
= MIN(p2
>> 2, PAGESIZE
);
157 (void) sprintf(name
, "zio_buf_%lu", (ulong_t
)size
);
158 zio_buf_cache
[c
] = kmem_cache_create(name
, size
,
159 align
, NULL
, NULL
, NULL
, NULL
, NULL
, cflags
);
162 * Since zio_data bufs do not appear in crash dumps, we
163 * pass KMC_NOTOUCH so that no allocator metadata is
164 * stored with the buffers.
166 (void) sprintf(name
, "zio_data_buf_%lu", (ulong_t
)size
);
167 zio_data_buf_cache
[c
] = kmem_cache_create(name
, size
,
168 align
, NULL
, NULL
, NULL
, NULL
, data_alloc_arena
,
169 cflags
| KMC_NOTOUCH
);
174 ASSERT(zio_buf_cache
[c
] != NULL
);
175 if (zio_buf_cache
[c
- 1] == NULL
)
176 zio_buf_cache
[c
- 1] = zio_buf_cache
[c
];
178 ASSERT(zio_data_buf_cache
[c
] != NULL
);
179 if (zio_data_buf_cache
[c
- 1] == NULL
)
180 zio_data_buf_cache
[c
- 1] = zio_data_buf_cache
[c
];
190 kmem_cache_t
*last_cache
= NULL
;
191 kmem_cache_t
*last_data_cache
= NULL
;
193 for (c
= 0; c
< SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
; c
++) {
194 if (zio_buf_cache
[c
] != last_cache
) {
195 last_cache
= zio_buf_cache
[c
];
196 kmem_cache_destroy(zio_buf_cache
[c
]);
198 zio_buf_cache
[c
] = NULL
;
200 if (zio_data_buf_cache
[c
] != last_data_cache
) {
201 last_data_cache
= zio_data_buf_cache
[c
];
202 kmem_cache_destroy(zio_data_buf_cache
[c
]);
204 zio_data_buf_cache
[c
] = NULL
;
207 kmem_cache_destroy(zio_link_cache
);
208 kmem_cache_destroy(zio_cache
);
214 * ==========================================================================
215 * Allocate and free I/O buffers
216 * ==========================================================================
220 * Use zio_buf_alloc to allocate ZFS metadata. This data will appear in a
221 * crashdump if the kernel panics, so use it judiciously. Obviously, it's
222 * useful to inspect ZFS metadata, but if possible, we should avoid keeping
223 * excess / transient data in-core during a crashdump.
226 zio_buf_alloc(size_t size
)
228 size_t c
= (size
- 1) >> SPA_MINBLOCKSHIFT
;
230 VERIFY3U(c
, <, SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
);
232 return (kmem_cache_alloc(zio_buf_cache
[c
], KM_PUSHPAGE
));
236 * Use zio_data_buf_alloc to allocate data. The data will not appear in a
237 * crashdump if the kernel panics. This exists so that we will limit the amount
238 * of ZFS data that shows up in a kernel crashdump. (Thus reducing the amount
239 * of kernel heap dumped to disk when the kernel panics)
242 zio_data_buf_alloc(size_t size
)
244 size_t c
= (size
- 1) >> SPA_MINBLOCKSHIFT
;
246 VERIFY3U(c
, <, SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
);
248 return (kmem_cache_alloc(zio_data_buf_cache
[c
], KM_PUSHPAGE
));
252 zio_buf_free(void *buf
, size_t size
)
254 size_t c
= (size
- 1) >> SPA_MINBLOCKSHIFT
;
256 VERIFY3U(c
, <, SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
);
258 kmem_cache_free(zio_buf_cache
[c
], buf
);
262 zio_data_buf_free(void *buf
, size_t size
)
264 size_t c
= (size
- 1) >> SPA_MINBLOCKSHIFT
;
266 VERIFY3U(c
, <, SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
);
268 kmem_cache_free(zio_data_buf_cache
[c
], buf
);
272 * ==========================================================================
273 * Push and pop I/O transform buffers
274 * ==========================================================================
277 zio_push_transform(zio_t
*zio
, abd_t
*data
, uint64_t size
, uint64_t bufsize
,
278 zio_transform_func_t
*transform
)
280 zio_transform_t
*zt
= kmem_alloc(sizeof (zio_transform_t
), KM_SLEEP
);
283 * Ensure that anyone expecting this zio to contain a linear ABD isn't
284 * going to get a nasty surprise when they try to access the data.
286 IMPLY(abd_is_linear(zio
->io_abd
), abd_is_linear(data
));
288 zt
->zt_orig_abd
= zio
->io_abd
;
289 zt
->zt_orig_size
= zio
->io_size
;
290 zt
->zt_bufsize
= bufsize
;
291 zt
->zt_transform
= transform
;
293 zt
->zt_next
= zio
->io_transform_stack
;
294 zio
->io_transform_stack
= zt
;
301 zio_pop_transforms(zio_t
*zio
)
305 while ((zt
= zio
->io_transform_stack
) != NULL
) {
306 if (zt
->zt_transform
!= NULL
)
307 zt
->zt_transform(zio
,
308 zt
->zt_orig_abd
, zt
->zt_orig_size
);
310 if (zt
->zt_bufsize
!= 0)
311 abd_free(zio
->io_abd
);
313 zio
->io_abd
= zt
->zt_orig_abd
;
314 zio
->io_size
= zt
->zt_orig_size
;
315 zio
->io_transform_stack
= zt
->zt_next
;
317 kmem_free(zt
, sizeof (zio_transform_t
));
322 * ==========================================================================
323 * I/O transform callbacks for subblocks and decompression
324 * ==========================================================================
327 zio_subblock(zio_t
*zio
, abd_t
*data
, uint64_t size
)
329 ASSERT(zio
->io_size
> size
);
331 if (zio
->io_type
== ZIO_TYPE_READ
)
332 abd_copy(data
, zio
->io_abd
, size
);
336 zio_decompress(zio_t
*zio
, abd_t
*data
, uint64_t size
)
338 if (zio
->io_error
== 0) {
339 void *tmp
= abd_borrow_buf(data
, size
);
340 int ret
= zio_decompress_data(BP_GET_COMPRESS(zio
->io_bp
),
341 zio
->io_abd
, tmp
, zio
->io_size
, size
);
342 abd_return_buf_copy(data
, tmp
, size
);
345 zio
->io_error
= SET_ERROR(EIO
);
350 * ==========================================================================
351 * I/O parent/child relationships and pipeline interlocks
352 * ==========================================================================
355 zio_walk_parents(zio_t
*cio
, zio_link_t
**zl
)
357 list_t
*pl
= &cio
->io_parent_list
;
359 *zl
= (*zl
== NULL
) ? list_head(pl
) : list_next(pl
, *zl
);
363 ASSERT((*zl
)->zl_child
== cio
);
364 return ((*zl
)->zl_parent
);
368 zio_walk_children(zio_t
*pio
, zio_link_t
**zl
)
370 list_t
*cl
= &pio
->io_child_list
;
372 *zl
= (*zl
== NULL
) ? list_head(cl
) : list_next(cl
, *zl
);
376 ASSERT((*zl
)->zl_parent
== pio
);
377 return ((*zl
)->zl_child
);
381 zio_unique_parent(zio_t
*cio
)
383 zio_link_t
*zl
= NULL
;
384 zio_t
*pio
= zio_walk_parents(cio
, &zl
);
386 VERIFY3P(zio_walk_parents(cio
, &zl
), ==, NULL
);
391 zio_add_child(zio_t
*pio
, zio_t
*cio
)
393 zio_link_t
*zl
= kmem_cache_alloc(zio_link_cache
, KM_SLEEP
);
396 * Logical I/Os can have logical, gang, or vdev children.
397 * Gang I/Os can have gang or vdev children.
398 * Vdev I/Os can only have vdev children.
399 * The following ASSERT captures all of these constraints.
401 ASSERT3S(cio
->io_child_type
, <=, pio
->io_child_type
);
406 mutex_enter(&cio
->io_lock
);
407 mutex_enter(&pio
->io_lock
);
409 ASSERT(pio
->io_state
[ZIO_WAIT_DONE
] == 0);
411 for (int w
= 0; w
< ZIO_WAIT_TYPES
; w
++)
412 pio
->io_children
[cio
->io_child_type
][w
] += !cio
->io_state
[w
];
414 list_insert_head(&pio
->io_child_list
, zl
);
415 list_insert_head(&cio
->io_parent_list
, zl
);
417 pio
->io_child_count
++;
418 cio
->io_parent_count
++;
420 mutex_exit(&pio
->io_lock
);
421 mutex_exit(&cio
->io_lock
);
425 zio_remove_child(zio_t
*pio
, zio_t
*cio
, zio_link_t
*zl
)
427 ASSERT(zl
->zl_parent
== pio
);
428 ASSERT(zl
->zl_child
== cio
);
430 mutex_enter(&cio
->io_lock
);
431 mutex_enter(&pio
->io_lock
);
433 list_remove(&pio
->io_child_list
, zl
);
434 list_remove(&cio
->io_parent_list
, zl
);
436 pio
->io_child_count
--;
437 cio
->io_parent_count
--;
439 mutex_exit(&pio
->io_lock
);
440 mutex_exit(&cio
->io_lock
);
442 kmem_cache_free(zio_link_cache
, zl
);
446 zio_wait_for_children(zio_t
*zio
, uint8_t childbits
, enum zio_wait_type wait
)
448 boolean_t waiting
= B_FALSE
;
450 mutex_enter(&zio
->io_lock
);
451 ASSERT(zio
->io_stall
== NULL
);
452 for (int c
= 0; c
< ZIO_CHILD_TYPES
; c
++) {
453 if (!(ZIO_CHILD_BIT_IS_SET(childbits
, c
)))
456 uint64_t *countp
= &zio
->io_children
[c
][wait
];
459 ASSERT3U(zio
->io_stage
, !=, ZIO_STAGE_OPEN
);
460 zio
->io_stall
= countp
;
465 mutex_exit(&zio
->io_lock
);
470 zio_notify_parent(zio_t
*pio
, zio_t
*zio
, enum zio_wait_type wait
)
472 uint64_t *countp
= &pio
->io_children
[zio
->io_child_type
][wait
];
473 int *errorp
= &pio
->io_child_error
[zio
->io_child_type
];
475 mutex_enter(&pio
->io_lock
);
476 if (zio
->io_error
&& !(zio
->io_flags
& ZIO_FLAG_DONT_PROPAGATE
))
477 *errorp
= zio_worst_error(*errorp
, zio
->io_error
);
478 pio
->io_reexecute
|= zio
->io_reexecute
;
479 ASSERT3U(*countp
, >, 0);
483 if (*countp
== 0 && pio
->io_stall
== countp
) {
484 zio_taskq_type_t type
=
485 pio
->io_stage
< ZIO_STAGE_VDEV_IO_START
? ZIO_TASKQ_ISSUE
:
487 pio
->io_stall
= NULL
;
488 mutex_exit(&pio
->io_lock
);
490 * Dispatch the parent zio in its own taskq so that
491 * the child can continue to make progress. This also
492 * prevents overflowing the stack when we have deeply nested
493 * parent-child relationships.
495 zio_taskq_dispatch(pio
, type
, B_FALSE
);
497 mutex_exit(&pio
->io_lock
);
502 zio_inherit_child_errors(zio_t
*zio
, enum zio_child c
)
504 if (zio
->io_child_error
[c
] != 0 && zio
->io_error
== 0)
505 zio
->io_error
= zio
->io_child_error
[c
];
509 zio_bookmark_compare(const void *x1
, const void *x2
)
511 const zio_t
*z1
= x1
;
512 const zio_t
*z2
= x2
;
514 if (z1
->io_bookmark
.zb_objset
< z2
->io_bookmark
.zb_objset
)
516 if (z1
->io_bookmark
.zb_objset
> z2
->io_bookmark
.zb_objset
)
519 if (z1
->io_bookmark
.zb_object
< z2
->io_bookmark
.zb_object
)
521 if (z1
->io_bookmark
.zb_object
> z2
->io_bookmark
.zb_object
)
524 if (z1
->io_bookmark
.zb_level
< z2
->io_bookmark
.zb_level
)
526 if (z1
->io_bookmark
.zb_level
> z2
->io_bookmark
.zb_level
)
529 if (z1
->io_bookmark
.zb_blkid
< z2
->io_bookmark
.zb_blkid
)
531 if (z1
->io_bookmark
.zb_blkid
> z2
->io_bookmark
.zb_blkid
)
543 * ==========================================================================
544 * Create the various types of I/O (read, write, free, etc)
545 * ==========================================================================
548 zio_create(zio_t
*pio
, spa_t
*spa
, uint64_t txg
, const blkptr_t
*bp
,
549 abd_t
*data
, uint64_t lsize
, uint64_t psize
, zio_done_func_t
*done
,
550 void *private, zio_type_t type
, zio_priority_t priority
,
551 enum zio_flag flags
, vdev_t
*vd
, uint64_t offset
,
552 const zbookmark_phys_t
*zb
, enum zio_stage stage
, enum zio_stage pipeline
)
556 ASSERT3U(psize
, <=, SPA_MAXBLOCKSIZE
);
557 ASSERT(P2PHASE(psize
, SPA_MINBLOCKSIZE
) == 0);
558 ASSERT(P2PHASE(offset
, SPA_MINBLOCKSIZE
) == 0);
560 ASSERT(!vd
|| spa_config_held(spa
, SCL_STATE_ALL
, RW_READER
));
561 ASSERT(!bp
|| !(flags
& ZIO_FLAG_CONFIG_WRITER
));
562 ASSERT(vd
|| stage
== ZIO_STAGE_OPEN
);
564 IMPLY(lsize
!= psize
, (flags
& ZIO_FLAG_RAW
) != 0);
566 zio
= kmem_cache_alloc(zio_cache
, KM_SLEEP
);
567 bzero(zio
, sizeof (zio_t
));
569 mutex_init(&zio
->io_lock
, NULL
, MUTEX_DEFAULT
, NULL
);
570 cv_init(&zio
->io_cv
, NULL
, CV_DEFAULT
, NULL
);
572 list_create(&zio
->io_parent_list
, sizeof (zio_link_t
),
573 offsetof(zio_link_t
, zl_parent_node
));
574 list_create(&zio
->io_child_list
, sizeof (zio_link_t
),
575 offsetof(zio_link_t
, zl_child_node
));
576 metaslab_trace_init(&zio
->io_alloc_list
);
579 zio
->io_child_type
= ZIO_CHILD_VDEV
;
580 else if (flags
& ZIO_FLAG_GANG_CHILD
)
581 zio
->io_child_type
= ZIO_CHILD_GANG
;
582 else if (flags
& ZIO_FLAG_DDT_CHILD
)
583 zio
->io_child_type
= ZIO_CHILD_DDT
;
585 zio
->io_child_type
= ZIO_CHILD_LOGICAL
;
588 zio
->io_bp
= (blkptr_t
*)bp
;
589 zio
->io_bp_copy
= *bp
;
590 zio
->io_bp_orig
= *bp
;
591 if (type
!= ZIO_TYPE_WRITE
||
592 zio
->io_child_type
== ZIO_CHILD_DDT
)
593 zio
->io_bp
= &zio
->io_bp_copy
; /* so caller can free */
594 if (zio
->io_child_type
== ZIO_CHILD_LOGICAL
)
595 zio
->io_logical
= zio
;
596 if (zio
->io_child_type
> ZIO_CHILD_GANG
&& BP_IS_GANG(bp
))
597 pipeline
|= ZIO_GANG_STAGES
;
603 zio
->io_private
= private;
605 zio
->io_priority
= priority
;
607 zio
->io_offset
= offset
;
608 zio
->io_orig_abd
= zio
->io_abd
= data
;
609 zio
->io_orig_size
= zio
->io_size
= psize
;
610 zio
->io_lsize
= lsize
;
611 zio
->io_orig_flags
= zio
->io_flags
= flags
;
612 zio
->io_orig_stage
= zio
->io_stage
= stage
;
613 zio
->io_orig_pipeline
= zio
->io_pipeline
= pipeline
;
614 zio
->io_pipeline_trace
= ZIO_STAGE_OPEN
;
616 zio
->io_state
[ZIO_WAIT_READY
] = (stage
>= ZIO_STAGE_READY
);
617 zio
->io_state
[ZIO_WAIT_DONE
] = (stage
>= ZIO_STAGE_DONE
);
620 zio
->io_bookmark
= *zb
;
623 if (zio
->io_logical
== NULL
)
624 zio
->io_logical
= pio
->io_logical
;
625 if (zio
->io_child_type
== ZIO_CHILD_GANG
)
626 zio
->io_gang_leader
= pio
->io_gang_leader
;
627 zio_add_child(pio
, zio
);
634 zio_destroy(zio_t
*zio
)
636 metaslab_trace_fini(&zio
->io_alloc_list
);
637 list_destroy(&zio
->io_parent_list
);
638 list_destroy(&zio
->io_child_list
);
639 mutex_destroy(&zio
->io_lock
);
640 cv_destroy(&zio
->io_cv
);
641 kmem_cache_free(zio_cache
, zio
);
645 zio_null(zio_t
*pio
, spa_t
*spa
, vdev_t
*vd
, zio_done_func_t
*done
,
646 void *private, enum zio_flag flags
)
650 zio
= zio_create(pio
, spa
, 0, NULL
, NULL
, 0, 0, done
, private,
651 ZIO_TYPE_NULL
, ZIO_PRIORITY_NOW
, flags
, vd
, 0, NULL
,
652 ZIO_STAGE_OPEN
, ZIO_INTERLOCK_PIPELINE
);
658 zio_root(spa_t
*spa
, zio_done_func_t
*done
, void *private, enum zio_flag flags
)
660 return (zio_null(NULL
, spa
, NULL
, done
, private, flags
));
664 zfs_blkptr_verify(spa_t
*spa
, const blkptr_t
*bp
)
666 if (!DMU_OT_IS_VALID(BP_GET_TYPE(bp
))) {
667 zfs_panic_recover("blkptr at %p has invalid TYPE %llu",
668 bp
, (longlong_t
)BP_GET_TYPE(bp
));
670 if (BP_GET_CHECKSUM(bp
) >= ZIO_CHECKSUM_FUNCTIONS
||
671 BP_GET_CHECKSUM(bp
) <= ZIO_CHECKSUM_ON
) {
672 zfs_panic_recover("blkptr at %p has invalid CHECKSUM %llu",
673 bp
, (longlong_t
)BP_GET_CHECKSUM(bp
));
675 if (BP_GET_COMPRESS(bp
) >= ZIO_COMPRESS_FUNCTIONS
||
676 BP_GET_COMPRESS(bp
) <= ZIO_COMPRESS_ON
) {
677 zfs_panic_recover("blkptr at %p has invalid COMPRESS %llu",
678 bp
, (longlong_t
)BP_GET_COMPRESS(bp
));
680 if (BP_GET_LSIZE(bp
) > SPA_MAXBLOCKSIZE
) {
681 zfs_panic_recover("blkptr at %p has invalid LSIZE %llu",
682 bp
, (longlong_t
)BP_GET_LSIZE(bp
));
684 if (BP_GET_PSIZE(bp
) > SPA_MAXBLOCKSIZE
) {
685 zfs_panic_recover("blkptr at %p has invalid PSIZE %llu",
686 bp
, (longlong_t
)BP_GET_PSIZE(bp
));
689 if (BP_IS_EMBEDDED(bp
)) {
690 if (BPE_GET_ETYPE(bp
) > NUM_BP_EMBEDDED_TYPES
) {
691 zfs_panic_recover("blkptr at %p has invalid ETYPE %llu",
692 bp
, (longlong_t
)BPE_GET_ETYPE(bp
));
697 * Do not verify individual DVAs if the config is not trusted. This
698 * will be done once the zio is executed in vdev_mirror_map_alloc.
700 if (!spa
->spa_trust_config
)
704 * Pool-specific checks.
706 * Note: it would be nice to verify that the blk_birth and
707 * BP_PHYSICAL_BIRTH() are not too large. However, spa_freeze()
708 * allows the birth time of log blocks (and dmu_sync()-ed blocks
709 * that are in the log) to be arbitrarily large.
711 for (int i
= 0; i
< BP_GET_NDVAS(bp
); i
++) {
712 uint64_t vdevid
= DVA_GET_VDEV(&bp
->blk_dva
[i
]);
713 if (vdevid
>= spa
->spa_root_vdev
->vdev_children
) {
714 zfs_panic_recover("blkptr at %p DVA %u has invalid "
716 bp
, i
, (longlong_t
)vdevid
);
719 vdev_t
*vd
= spa
->spa_root_vdev
->vdev_child
[vdevid
];
721 zfs_panic_recover("blkptr at %p DVA %u has invalid "
723 bp
, i
, (longlong_t
)vdevid
);
726 if (vd
->vdev_ops
== &vdev_hole_ops
) {
727 zfs_panic_recover("blkptr at %p DVA %u has hole "
729 bp
, i
, (longlong_t
)vdevid
);
732 if (vd
->vdev_ops
== &vdev_missing_ops
) {
734 * "missing" vdevs are valid during import, but we
735 * don't have their detailed info (e.g. asize), so
736 * we can't perform any more checks on them.
740 uint64_t offset
= DVA_GET_OFFSET(&bp
->blk_dva
[i
]);
741 uint64_t asize
= DVA_GET_ASIZE(&bp
->blk_dva
[i
]);
743 asize
= vdev_psize_to_asize(vd
, SPA_GANGBLOCKSIZE
);
744 if (offset
+ asize
> vd
->vdev_asize
) {
745 zfs_panic_recover("blkptr at %p DVA %u has invalid "
747 bp
, i
, (longlong_t
)offset
);
753 zfs_dva_valid(spa_t
*spa
, const dva_t
*dva
, const blkptr_t
*bp
)
755 uint64_t vdevid
= DVA_GET_VDEV(dva
);
757 if (vdevid
>= spa
->spa_root_vdev
->vdev_children
)
760 vdev_t
*vd
= spa
->spa_root_vdev
->vdev_child
[vdevid
];
764 if (vd
->vdev_ops
== &vdev_hole_ops
)
767 if (vd
->vdev_ops
== &vdev_missing_ops
) {
771 uint64_t offset
= DVA_GET_OFFSET(dva
);
772 uint64_t asize
= DVA_GET_ASIZE(dva
);
775 asize
= vdev_psize_to_asize(vd
, SPA_GANGBLOCKSIZE
);
776 if (offset
+ asize
> vd
->vdev_asize
)
783 zio_read(zio_t
*pio
, spa_t
*spa
, const blkptr_t
*bp
,
784 abd_t
*data
, uint64_t size
, zio_done_func_t
*done
, void *private,
785 zio_priority_t priority
, enum zio_flag flags
, const zbookmark_phys_t
*zb
)
789 zfs_blkptr_verify(spa
, bp
);
791 zio
= zio_create(pio
, spa
, BP_PHYSICAL_BIRTH(bp
), bp
,
792 data
, size
, size
, done
, private,
793 ZIO_TYPE_READ
, priority
, flags
, NULL
, 0, zb
,
794 ZIO_STAGE_OPEN
, (flags
& ZIO_FLAG_DDT_CHILD
) ?
795 ZIO_DDT_CHILD_READ_PIPELINE
: ZIO_READ_PIPELINE
);
801 zio_write(zio_t
*pio
, spa_t
*spa
, uint64_t txg
, blkptr_t
*bp
,
802 abd_t
*data
, uint64_t lsize
, uint64_t psize
, const zio_prop_t
*zp
,
803 zio_done_func_t
*ready
, zio_done_func_t
*children_ready
,
804 zio_done_func_t
*physdone
, zio_done_func_t
*done
,
805 void *private, zio_priority_t priority
, enum zio_flag flags
,
806 const zbookmark_phys_t
*zb
)
810 ASSERT(zp
->zp_checksum
>= ZIO_CHECKSUM_OFF
&&
811 zp
->zp_checksum
< ZIO_CHECKSUM_FUNCTIONS
&&
812 zp
->zp_compress
>= ZIO_COMPRESS_OFF
&&
813 zp
->zp_compress
< ZIO_COMPRESS_FUNCTIONS
&&
814 DMU_OT_IS_VALID(zp
->zp_type
) &&
817 zp
->zp_copies
<= spa_max_replication(spa
));
819 zio
= zio_create(pio
, spa
, txg
, bp
, data
, lsize
, psize
, done
, private,
820 ZIO_TYPE_WRITE
, priority
, flags
, NULL
, 0, zb
,
821 ZIO_STAGE_OPEN
, (flags
& ZIO_FLAG_DDT_CHILD
) ?
822 ZIO_DDT_CHILD_WRITE_PIPELINE
: ZIO_WRITE_PIPELINE
);
824 zio
->io_ready
= ready
;
825 zio
->io_children_ready
= children_ready
;
826 zio
->io_physdone
= physdone
;
830 * Data can be NULL if we are going to call zio_write_override() to
831 * provide the already-allocated BP. But we may need the data to
832 * verify a dedup hit (if requested). In this case, don't try to
833 * dedup (just take the already-allocated BP verbatim).
835 if (data
== NULL
&& zio
->io_prop
.zp_dedup_verify
) {
836 zio
->io_prop
.zp_dedup
= zio
->io_prop
.zp_dedup_verify
= B_FALSE
;
843 zio_rewrite(zio_t
*pio
, spa_t
*spa
, uint64_t txg
, blkptr_t
*bp
, abd_t
*data
,
844 uint64_t size
, zio_done_func_t
*done
, void *private,
845 zio_priority_t priority
, enum zio_flag flags
, zbookmark_phys_t
*zb
)
849 zio
= zio_create(pio
, spa
, txg
, bp
, data
, size
, size
, done
, private,
850 ZIO_TYPE_WRITE
, priority
, flags
| ZIO_FLAG_IO_REWRITE
, NULL
, 0, zb
,
851 ZIO_STAGE_OPEN
, ZIO_REWRITE_PIPELINE
);
857 zio_write_override(zio_t
*zio
, blkptr_t
*bp
, int copies
, boolean_t nopwrite
)
859 ASSERT(zio
->io_type
== ZIO_TYPE_WRITE
);
860 ASSERT(zio
->io_child_type
== ZIO_CHILD_LOGICAL
);
861 ASSERT(zio
->io_stage
== ZIO_STAGE_OPEN
);
862 ASSERT(zio
->io_txg
== spa_syncing_txg(zio
->io_spa
));
865 * We must reset the io_prop to match the values that existed
866 * when the bp was first written by dmu_sync() keeping in mind
867 * that nopwrite and dedup are mutually exclusive.
869 zio
->io_prop
.zp_dedup
= nopwrite
? B_FALSE
: zio
->io_prop
.zp_dedup
;
870 zio
->io_prop
.zp_nopwrite
= nopwrite
;
871 zio
->io_prop
.zp_copies
= copies
;
872 zio
->io_bp_override
= bp
;
876 zio_free(spa_t
*spa
, uint64_t txg
, const blkptr_t
*bp
)
879 zfs_blkptr_verify(spa
, bp
);
882 * The check for EMBEDDED is a performance optimization. We
883 * process the free here (by ignoring it) rather than
884 * putting it on the list and then processing it in zio_free_sync().
886 if (BP_IS_EMBEDDED(bp
))
888 metaslab_check_free(spa
, bp
);
891 * Frees that are for the currently-syncing txg, are not going to be
892 * deferred, and which will not need to do a read (i.e. not GANG or
893 * DEDUP), can be processed immediately. Otherwise, put them on the
894 * in-memory list for later processing.
896 if (BP_IS_GANG(bp
) || BP_GET_DEDUP(bp
) ||
897 txg
!= spa
->spa_syncing_txg
||
898 spa_sync_pass(spa
) >= zfs_sync_pass_deferred_free
) {
899 bplist_append(&spa
->spa_free_bplist
[txg
& TXG_MASK
], bp
);
901 VERIFY0(zio_wait(zio_free_sync(NULL
, spa
, txg
, bp
, 0)));
906 zio_free_sync(zio_t
*pio
, spa_t
*spa
, uint64_t txg
, const blkptr_t
*bp
,
910 enum zio_stage stage
= ZIO_FREE_PIPELINE
;
912 ASSERT(!BP_IS_HOLE(bp
));
913 ASSERT(spa_syncing_txg(spa
) == txg
);
914 ASSERT(spa_sync_pass(spa
) < zfs_sync_pass_deferred_free
);
916 if (BP_IS_EMBEDDED(bp
))
917 return (zio_null(pio
, spa
, NULL
, NULL
, NULL
, 0));
919 metaslab_check_free(spa
, bp
);
923 * GANG and DEDUP blocks can induce a read (for the gang block header,
924 * or the DDT), so issue them asynchronously so that this thread is
927 if (BP_IS_GANG(bp
) || BP_GET_DEDUP(bp
))
928 stage
|= ZIO_STAGE_ISSUE_ASYNC
;
930 zio
= zio_create(pio
, spa
, txg
, bp
, NULL
, BP_GET_PSIZE(bp
),
931 BP_GET_PSIZE(bp
), NULL
, NULL
, ZIO_TYPE_FREE
, ZIO_PRIORITY_NOW
,
932 flags
, NULL
, 0, NULL
, ZIO_STAGE_OPEN
, stage
);
938 zio_claim(zio_t
*pio
, spa_t
*spa
, uint64_t txg
, const blkptr_t
*bp
,
939 zio_done_func_t
*done
, void *private, enum zio_flag flags
)
943 zfs_blkptr_verify(spa
, bp
);
945 if (BP_IS_EMBEDDED(bp
))
946 return (zio_null(pio
, spa
, NULL
, NULL
, NULL
, 0));
949 * A claim is an allocation of a specific block. Claims are needed
950 * to support immediate writes in the intent log. The issue is that
951 * immediate writes contain committed data, but in a txg that was
952 * *not* committed. Upon opening the pool after an unclean shutdown,
953 * the intent log claims all blocks that contain immediate write data
954 * so that the SPA knows they're in use.
956 * All claims *must* be resolved in the first txg -- before the SPA
957 * starts allocating blocks -- so that nothing is allocated twice.
958 * If txg == 0 we just verify that the block is claimable.
960 ASSERT3U(spa
->spa_uberblock
.ub_rootbp
.blk_birth
, <,
961 spa_min_claim_txg(spa
));
962 ASSERT(txg
== spa_min_claim_txg(spa
) || txg
== 0);
963 ASSERT(!BP_GET_DEDUP(bp
) || !spa_writeable(spa
)); /* zdb(1M) */
965 zio
= zio_create(pio
, spa
, txg
, bp
, NULL
, BP_GET_PSIZE(bp
),
966 BP_GET_PSIZE(bp
), done
, private, ZIO_TYPE_CLAIM
, ZIO_PRIORITY_NOW
,
967 flags
, NULL
, 0, NULL
, ZIO_STAGE_OPEN
, ZIO_CLAIM_PIPELINE
);
968 ASSERT0(zio
->io_queued_timestamp
);
974 zio_ioctl(zio_t
*pio
, spa_t
*spa
, vdev_t
*vd
, int cmd
,
975 zio_done_func_t
*done
, void *private, enum zio_flag flags
)
980 if (vd
->vdev_children
== 0) {
981 zio
= zio_create(pio
, spa
, 0, NULL
, NULL
, 0, 0, done
, private,
982 ZIO_TYPE_IOCTL
, ZIO_PRIORITY_NOW
, flags
, vd
, 0, NULL
,
983 ZIO_STAGE_OPEN
, ZIO_IOCTL_PIPELINE
);
987 zio
= zio_null(pio
, spa
, NULL
, NULL
, NULL
, flags
);
989 for (c
= 0; c
< vd
->vdev_children
; c
++)
990 zio_nowait(zio_ioctl(zio
, spa
, vd
->vdev_child
[c
], cmd
,
991 done
, private, flags
));
998 zio_read_phys(zio_t
*pio
, vdev_t
*vd
, uint64_t offset
, uint64_t size
,
999 abd_t
*data
, int checksum
, zio_done_func_t
*done
, void *private,
1000 zio_priority_t priority
, enum zio_flag flags
, boolean_t labels
)
1004 ASSERT(vd
->vdev_children
== 0);
1005 ASSERT(!labels
|| offset
+ size
<= VDEV_LABEL_START_SIZE
||
1006 offset
>= vd
->vdev_psize
- VDEV_LABEL_END_SIZE
);
1007 ASSERT3U(offset
+ size
, <=, vd
->vdev_psize
);
1009 zio
= zio_create(pio
, vd
->vdev_spa
, 0, NULL
, data
, size
, size
, done
,
1010 private, ZIO_TYPE_READ
, priority
, flags
| ZIO_FLAG_PHYSICAL
, vd
,
1011 offset
, NULL
, ZIO_STAGE_OPEN
, ZIO_READ_PHYS_PIPELINE
);
1013 zio
->io_prop
.zp_checksum
= checksum
;
1019 zio_write_phys(zio_t
*pio
, vdev_t
*vd
, uint64_t offset
, uint64_t size
,
1020 abd_t
*data
, int checksum
, zio_done_func_t
*done
, void *private,
1021 zio_priority_t priority
, enum zio_flag flags
, boolean_t labels
)
1025 ASSERT(vd
->vdev_children
== 0);
1026 ASSERT(!labels
|| offset
+ size
<= VDEV_LABEL_START_SIZE
||
1027 offset
>= vd
->vdev_psize
- VDEV_LABEL_END_SIZE
);
1028 ASSERT3U(offset
+ size
, <=, vd
->vdev_psize
);
1030 zio
= zio_create(pio
, vd
->vdev_spa
, 0, NULL
, data
, size
, size
, done
,
1031 private, ZIO_TYPE_WRITE
, priority
, flags
| ZIO_FLAG_PHYSICAL
, vd
,
1032 offset
, NULL
, ZIO_STAGE_OPEN
, ZIO_WRITE_PHYS_PIPELINE
);
1034 zio
->io_prop
.zp_checksum
= checksum
;
1036 if (zio_checksum_table
[checksum
].ci_flags
& ZCHECKSUM_FLAG_EMBEDDED
) {
1038 * zec checksums are necessarily destructive -- they modify
1039 * the end of the write buffer to hold the verifier/checksum.
1040 * Therefore, we must make a local copy in case the data is
1041 * being written to multiple places in parallel.
1043 abd_t
*wbuf
= abd_alloc_sametype(data
, size
);
1044 abd_copy(wbuf
, data
, size
);
1046 zio_push_transform(zio
, wbuf
, size
, size
, NULL
);
1053 * Create a child I/O to do some work for us.
1056 zio_vdev_child_io(zio_t
*pio
, blkptr_t
*bp
, vdev_t
*vd
, uint64_t offset
,
1057 abd_t
*data
, uint64_t size
, int type
, zio_priority_t priority
,
1058 enum zio_flag flags
, zio_done_func_t
*done
, void *private)
1060 enum zio_stage pipeline
= ZIO_VDEV_CHILD_PIPELINE
;
1064 * vdev child I/Os do not propagate their error to the parent.
1065 * Therefore, for correct operation the caller *must* check for
1066 * and handle the error in the child i/o's done callback.
1067 * The only exceptions are i/os that we don't care about
1068 * (OPTIONAL or REPAIR).
1070 ASSERT((flags
& ZIO_FLAG_OPTIONAL
) || (flags
& ZIO_FLAG_IO_REPAIR
) ||
1074 * In the common case, where the parent zio was to a normal vdev,
1075 * the child zio must be to a child vdev of that vdev. Otherwise,
1076 * the child zio must be to a top-level vdev.
1078 if (pio
->io_vd
!= NULL
&& pio
->io_vd
->vdev_ops
!= &vdev_indirect_ops
) {
1079 ASSERT3P(vd
->vdev_parent
, ==, pio
->io_vd
);
1081 ASSERT3P(vd
, ==, vd
->vdev_top
);
1084 if (type
== ZIO_TYPE_READ
&& bp
!= NULL
) {
1086 * If we have the bp, then the child should perform the
1087 * checksum and the parent need not. This pushes error
1088 * detection as close to the leaves as possible and
1089 * eliminates redundant checksums in the interior nodes.
1091 pipeline
|= ZIO_STAGE_CHECKSUM_VERIFY
;
1092 pio
->io_pipeline
&= ~ZIO_STAGE_CHECKSUM_VERIFY
;
1095 if (vd
->vdev_ops
->vdev_op_leaf
) {
1096 ASSERT0(vd
->vdev_children
);
1097 offset
+= VDEV_LABEL_START_SIZE
;
1100 flags
|= ZIO_VDEV_CHILD_FLAGS(pio
);
1103 * If we've decided to do a repair, the write is not speculative --
1104 * even if the original read was.
1106 if (flags
& ZIO_FLAG_IO_REPAIR
)
1107 flags
&= ~ZIO_FLAG_SPECULATIVE
;
1110 * If we're creating a child I/O that is not associated with a
1111 * top-level vdev, then the child zio is not an allocating I/O.
1112 * If this is a retried I/O then we ignore it since we will
1113 * have already processed the original allocating I/O.
1115 if (flags
& ZIO_FLAG_IO_ALLOCATING
&&
1116 (vd
!= vd
->vdev_top
|| (flags
& ZIO_FLAG_IO_RETRY
))) {
1117 metaslab_class_t
*mc
= spa_normal_class(pio
->io_spa
);
1119 ASSERT(mc
->mc_alloc_throttle_enabled
);
1120 ASSERT(type
== ZIO_TYPE_WRITE
);
1121 ASSERT(priority
== ZIO_PRIORITY_ASYNC_WRITE
);
1122 ASSERT(!(flags
& ZIO_FLAG_IO_REPAIR
));
1123 ASSERT(!(pio
->io_flags
& ZIO_FLAG_IO_REWRITE
) ||
1124 pio
->io_child_type
== ZIO_CHILD_GANG
);
1126 flags
&= ~ZIO_FLAG_IO_ALLOCATING
;
1129 zio
= zio_create(pio
, pio
->io_spa
, pio
->io_txg
, bp
, data
, size
, size
,
1130 done
, private, type
, priority
, flags
, vd
, offset
, &pio
->io_bookmark
,
1131 ZIO_STAGE_VDEV_IO_START
>> 1, pipeline
);
1132 ASSERT3U(zio
->io_child_type
, ==, ZIO_CHILD_VDEV
);
1134 zio
->io_physdone
= pio
->io_physdone
;
1135 if (vd
->vdev_ops
->vdev_op_leaf
&& zio
->io_logical
!= NULL
)
1136 zio
->io_logical
->io_phys_children
++;
1142 zio_vdev_delegated_io(vdev_t
*vd
, uint64_t offset
, abd_t
*data
, uint64_t size
,
1143 int type
, zio_priority_t priority
, enum zio_flag flags
,
1144 zio_done_func_t
*done
, void *private)
1148 ASSERT(vd
->vdev_ops
->vdev_op_leaf
);
1150 zio
= zio_create(NULL
, vd
->vdev_spa
, 0, NULL
,
1151 data
, size
, size
, done
, private, type
, priority
,
1152 flags
| ZIO_FLAG_CANFAIL
| ZIO_FLAG_DONT_RETRY
| ZIO_FLAG_DELEGATED
,
1154 ZIO_STAGE_VDEV_IO_START
>> 1, ZIO_VDEV_CHILD_PIPELINE
);
1160 zio_flush(zio_t
*zio
, vdev_t
*vd
)
1162 zio_nowait(zio_ioctl(zio
, zio
->io_spa
, vd
, DKIOCFLUSHWRITECACHE
,
1164 ZIO_FLAG_CANFAIL
| ZIO_FLAG_DONT_PROPAGATE
| ZIO_FLAG_DONT_RETRY
));
1168 zio_shrink(zio_t
*zio
, uint64_t size
)
1170 ASSERT3P(zio
->io_executor
, ==, NULL
);
1171 ASSERT3P(zio
->io_orig_size
, ==, zio
->io_size
);
1172 ASSERT3U(size
, <=, zio
->io_size
);
1175 * We don't shrink for raidz because of problems with the
1176 * reconstruction when reading back less than the block size.
1177 * Note, BP_IS_RAIDZ() assumes no compression.
1179 ASSERT(BP_GET_COMPRESS(zio
->io_bp
) == ZIO_COMPRESS_OFF
);
1180 if (!BP_IS_RAIDZ(zio
->io_bp
)) {
1181 /* we are not doing a raw write */
1182 ASSERT3U(zio
->io_size
, ==, zio
->io_lsize
);
1183 zio
->io_orig_size
= zio
->io_size
= zio
->io_lsize
= size
;
1188 * ==========================================================================
1189 * Prepare to read and write logical blocks
1190 * ==========================================================================
1194 zio_read_bp_init(zio_t
*zio
)
1196 blkptr_t
*bp
= zio
->io_bp
;
1198 ASSERT3P(zio
->io_bp
, ==, &zio
->io_bp_copy
);
1200 if (BP_GET_COMPRESS(bp
) != ZIO_COMPRESS_OFF
&&
1201 zio
->io_child_type
== ZIO_CHILD_LOGICAL
&&
1202 !(zio
->io_flags
& ZIO_FLAG_RAW
)) {
1204 BP_IS_EMBEDDED(bp
) ? BPE_GET_PSIZE(bp
) : BP_GET_PSIZE(bp
);
1205 zio_push_transform(zio
, abd_alloc_sametype(zio
->io_abd
, psize
),
1206 psize
, psize
, zio_decompress
);
1209 if (BP_IS_EMBEDDED(bp
) && BPE_GET_ETYPE(bp
) == BP_EMBEDDED_TYPE_DATA
) {
1210 zio
->io_pipeline
= ZIO_INTERLOCK_PIPELINE
;
1212 int psize
= BPE_GET_PSIZE(bp
);
1213 void *data
= abd_borrow_buf(zio
->io_abd
, psize
);
1214 decode_embedded_bp_compressed(bp
, data
);
1215 abd_return_buf_copy(zio
->io_abd
, data
, psize
);
1217 ASSERT(!BP_IS_EMBEDDED(bp
));
1218 ASSERT3P(zio
->io_bp
, ==, &zio
->io_bp_copy
);
1221 if (!DMU_OT_IS_METADATA(BP_GET_TYPE(bp
)) && BP_GET_LEVEL(bp
) == 0)
1222 zio
->io_flags
|= ZIO_FLAG_DONT_CACHE
;
1224 if (BP_GET_TYPE(bp
) == DMU_OT_DDT_ZAP
)
1225 zio
->io_flags
|= ZIO_FLAG_DONT_CACHE
;
1227 if (BP_GET_DEDUP(bp
) && zio
->io_child_type
== ZIO_CHILD_LOGICAL
)
1228 zio
->io_pipeline
= ZIO_DDT_READ_PIPELINE
;
1230 return (ZIO_PIPELINE_CONTINUE
);
1234 zio_write_bp_init(zio_t
*zio
)
1236 if (!IO_IS_ALLOCATING(zio
))
1237 return (ZIO_PIPELINE_CONTINUE
);
1239 ASSERT(zio
->io_child_type
!= ZIO_CHILD_DDT
);
1241 if (zio
->io_bp_override
) {
1242 blkptr_t
*bp
= zio
->io_bp
;
1243 zio_prop_t
*zp
= &zio
->io_prop
;
1245 ASSERT(bp
->blk_birth
!= zio
->io_txg
);
1246 ASSERT(BP_GET_DEDUP(zio
->io_bp_override
) == 0);
1248 *bp
= *zio
->io_bp_override
;
1249 zio
->io_pipeline
= ZIO_INTERLOCK_PIPELINE
;
1251 if (BP_IS_EMBEDDED(bp
))
1252 return (ZIO_PIPELINE_CONTINUE
);
1255 * If we've been overridden and nopwrite is set then
1256 * set the flag accordingly to indicate that a nopwrite
1257 * has already occurred.
1259 if (!BP_IS_HOLE(bp
) && zp
->zp_nopwrite
) {
1260 ASSERT(!zp
->zp_dedup
);
1261 ASSERT3U(BP_GET_CHECKSUM(bp
), ==, zp
->zp_checksum
);
1262 zio
->io_flags
|= ZIO_FLAG_NOPWRITE
;
1263 return (ZIO_PIPELINE_CONTINUE
);
1266 ASSERT(!zp
->zp_nopwrite
);
1268 if (BP_IS_HOLE(bp
) || !zp
->zp_dedup
)
1269 return (ZIO_PIPELINE_CONTINUE
);
1271 ASSERT((zio_checksum_table
[zp
->zp_checksum
].ci_flags
&
1272 ZCHECKSUM_FLAG_DEDUP
) || zp
->zp_dedup_verify
);
1274 if (BP_GET_CHECKSUM(bp
) == zp
->zp_checksum
) {
1275 BP_SET_DEDUP(bp
, 1);
1276 zio
->io_pipeline
|= ZIO_STAGE_DDT_WRITE
;
1277 return (ZIO_PIPELINE_CONTINUE
);
1281 * We were unable to handle this as an override bp, treat
1282 * it as a regular write I/O.
1284 zio
->io_bp_override
= NULL
;
1285 *bp
= zio
->io_bp_orig
;
1286 zio
->io_pipeline
= zio
->io_orig_pipeline
;
1289 return (ZIO_PIPELINE_CONTINUE
);
1293 zio_write_compress(zio_t
*zio
)
1295 spa_t
*spa
= zio
->io_spa
;
1296 zio_prop_t
*zp
= &zio
->io_prop
;
1297 enum zio_compress compress
= zp
->zp_compress
;
1298 blkptr_t
*bp
= zio
->io_bp
;
1299 uint64_t lsize
= zio
->io_lsize
;
1300 uint64_t psize
= zio
->io_size
;
1303 EQUIV(lsize
!= psize
, (zio
->io_flags
& ZIO_FLAG_RAW
) != 0);
1306 * If our children haven't all reached the ready stage,
1307 * wait for them and then repeat this pipeline stage.
1309 if (zio_wait_for_children(zio
, ZIO_CHILD_LOGICAL_BIT
|
1310 ZIO_CHILD_GANG_BIT
, ZIO_WAIT_READY
)) {
1311 return (ZIO_PIPELINE_STOP
);
1314 if (!IO_IS_ALLOCATING(zio
))
1315 return (ZIO_PIPELINE_CONTINUE
);
1317 if (zio
->io_children_ready
!= NULL
) {
1319 * Now that all our children are ready, run the callback
1320 * associated with this zio in case it wants to modify the
1321 * data to be written.
1323 ASSERT3U(zp
->zp_level
, >, 0);
1324 zio
->io_children_ready(zio
);
1327 ASSERT(zio
->io_child_type
!= ZIO_CHILD_DDT
);
1328 ASSERT(zio
->io_bp_override
== NULL
);
1330 if (!BP_IS_HOLE(bp
) && bp
->blk_birth
== zio
->io_txg
) {
1332 * We're rewriting an existing block, which means we're
1333 * working on behalf of spa_sync(). For spa_sync() to
1334 * converge, it must eventually be the case that we don't
1335 * have to allocate new blocks. But compression changes
1336 * the blocksize, which forces a reallocate, and makes
1337 * convergence take longer. Therefore, after the first
1338 * few passes, stop compressing to ensure convergence.
1340 pass
= spa_sync_pass(spa
);
1342 ASSERT(zio
->io_txg
== spa_syncing_txg(spa
));
1343 ASSERT(zio
->io_child_type
== ZIO_CHILD_LOGICAL
);
1344 ASSERT(!BP_GET_DEDUP(bp
));
1346 if (pass
>= zfs_sync_pass_dont_compress
)
1347 compress
= ZIO_COMPRESS_OFF
;
1349 /* Make sure someone doesn't change their mind on overwrites */
1350 ASSERT(BP_IS_EMBEDDED(bp
) || MIN(zp
->zp_copies
+ BP_IS_GANG(bp
),
1351 spa_max_replication(spa
)) == BP_GET_NDVAS(bp
));
1354 /* If it's a compressed write that is not raw, compress the buffer. */
1355 if (compress
!= ZIO_COMPRESS_OFF
&& psize
== lsize
) {
1356 void *cbuf
= zio_buf_alloc(lsize
);
1357 psize
= zio_compress_data(compress
, zio
->io_abd
, cbuf
, lsize
);
1358 if (psize
== 0 || psize
== lsize
) {
1359 compress
= ZIO_COMPRESS_OFF
;
1360 zio_buf_free(cbuf
, lsize
);
1361 } else if (!zp
->zp_dedup
&& psize
<= BPE_PAYLOAD_SIZE
&&
1362 zp
->zp_level
== 0 && !DMU_OT_HAS_FILL(zp
->zp_type
) &&
1363 spa_feature_is_enabled(spa
, SPA_FEATURE_EMBEDDED_DATA
)) {
1364 encode_embedded_bp_compressed(bp
,
1365 cbuf
, compress
, lsize
, psize
);
1366 BPE_SET_ETYPE(bp
, BP_EMBEDDED_TYPE_DATA
);
1367 BP_SET_TYPE(bp
, zio
->io_prop
.zp_type
);
1368 BP_SET_LEVEL(bp
, zio
->io_prop
.zp_level
);
1369 zio_buf_free(cbuf
, lsize
);
1370 bp
->blk_birth
= zio
->io_txg
;
1371 zio
->io_pipeline
= ZIO_INTERLOCK_PIPELINE
;
1372 ASSERT(spa_feature_is_active(spa
,
1373 SPA_FEATURE_EMBEDDED_DATA
));
1374 return (ZIO_PIPELINE_CONTINUE
);
1377 * Round up compressed size up to the ashift
1378 * of the smallest-ashift device, and zero the tail.
1379 * This ensures that the compressed size of the BP
1380 * (and thus compressratio property) are correct,
1381 * in that we charge for the padding used to fill out
1384 ASSERT3U(spa
->spa_min_ashift
, >=, SPA_MINBLOCKSHIFT
);
1385 size_t rounded
= (size_t)P2ROUNDUP(psize
,
1386 1ULL << spa
->spa_min_ashift
);
1387 if (rounded
>= lsize
) {
1388 compress
= ZIO_COMPRESS_OFF
;
1389 zio_buf_free(cbuf
, lsize
);
1392 abd_t
*cdata
= abd_get_from_buf(cbuf
, lsize
);
1393 abd_take_ownership_of_buf(cdata
, B_TRUE
);
1394 abd_zero_off(cdata
, psize
, rounded
- psize
);
1396 zio_push_transform(zio
, cdata
,
1397 psize
, lsize
, NULL
);
1402 * We were unable to handle this as an override bp, treat
1403 * it as a regular write I/O.
1405 zio
->io_bp_override
= NULL
;
1406 *bp
= zio
->io_bp_orig
;
1407 zio
->io_pipeline
= zio
->io_orig_pipeline
;
1409 ASSERT3U(psize
, !=, 0);
1413 * The final pass of spa_sync() must be all rewrites, but the first
1414 * few passes offer a trade-off: allocating blocks defers convergence,
1415 * but newly allocated blocks are sequential, so they can be written
1416 * to disk faster. Therefore, we allow the first few passes of
1417 * spa_sync() to allocate new blocks, but force rewrites after that.
1418 * There should only be a handful of blocks after pass 1 in any case.
1420 if (!BP_IS_HOLE(bp
) && bp
->blk_birth
== zio
->io_txg
&&
1421 BP_GET_PSIZE(bp
) == psize
&&
1422 pass
>= zfs_sync_pass_rewrite
) {
1424 enum zio_stage gang_stages
= zio
->io_pipeline
& ZIO_GANG_STAGES
;
1425 zio
->io_pipeline
= ZIO_REWRITE_PIPELINE
| gang_stages
;
1426 zio
->io_flags
|= ZIO_FLAG_IO_REWRITE
;
1429 zio
->io_pipeline
= ZIO_WRITE_PIPELINE
;
1433 if (zio
->io_bp_orig
.blk_birth
!= 0 &&
1434 spa_feature_is_active(spa
, SPA_FEATURE_HOLE_BIRTH
)) {
1435 BP_SET_LSIZE(bp
, lsize
);
1436 BP_SET_TYPE(bp
, zp
->zp_type
);
1437 BP_SET_LEVEL(bp
, zp
->zp_level
);
1438 BP_SET_BIRTH(bp
, zio
->io_txg
, 0);
1440 zio
->io_pipeline
= ZIO_INTERLOCK_PIPELINE
;
1442 ASSERT(zp
->zp_checksum
!= ZIO_CHECKSUM_GANG_HEADER
);
1443 BP_SET_LSIZE(bp
, lsize
);
1444 BP_SET_TYPE(bp
, zp
->zp_type
);
1445 BP_SET_LEVEL(bp
, zp
->zp_level
);
1446 BP_SET_PSIZE(bp
, psize
);
1447 BP_SET_COMPRESS(bp
, compress
);
1448 BP_SET_CHECKSUM(bp
, zp
->zp_checksum
);
1449 BP_SET_DEDUP(bp
, zp
->zp_dedup
);
1450 BP_SET_BYTEORDER(bp
, ZFS_HOST_BYTEORDER
);
1452 ASSERT(zio
->io_child_type
== ZIO_CHILD_LOGICAL
);
1453 ASSERT(!(zio
->io_flags
& ZIO_FLAG_IO_REWRITE
));
1454 zio
->io_pipeline
= ZIO_DDT_WRITE_PIPELINE
;
1456 if (zp
->zp_nopwrite
) {
1457 ASSERT(zio
->io_child_type
== ZIO_CHILD_LOGICAL
);
1458 ASSERT(!(zio
->io_flags
& ZIO_FLAG_IO_REWRITE
));
1459 zio
->io_pipeline
|= ZIO_STAGE_NOP_WRITE
;
1462 return (ZIO_PIPELINE_CONTINUE
);
1466 zio_free_bp_init(zio_t
*zio
)
1468 blkptr_t
*bp
= zio
->io_bp
;
1470 if (zio
->io_child_type
== ZIO_CHILD_LOGICAL
) {
1471 if (BP_GET_DEDUP(bp
))
1472 zio
->io_pipeline
= ZIO_DDT_FREE_PIPELINE
;
1475 ASSERT3P(zio
->io_bp
, ==, &zio
->io_bp_copy
);
1477 return (ZIO_PIPELINE_CONTINUE
);
1481 * ==========================================================================
1482 * Execute the I/O pipeline
1483 * ==========================================================================
1487 zio_taskq_dispatch(zio_t
*zio
, zio_taskq_type_t q
, boolean_t cutinline
)
1489 spa_t
*spa
= zio
->io_spa
;
1490 zio_type_t t
= zio
->io_type
;
1491 int flags
= (cutinline
? TQ_FRONT
: 0);
1494 * If we're a config writer or a probe, the normal issue and
1495 * interrupt threads may all be blocked waiting for the config lock.
1496 * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL.
1498 if (zio
->io_flags
& (ZIO_FLAG_CONFIG_WRITER
| ZIO_FLAG_PROBE
))
1502 * A similar issue exists for the L2ARC write thread until L2ARC 2.0.
1504 if (t
== ZIO_TYPE_WRITE
&& zio
->io_vd
&& zio
->io_vd
->vdev_aux
)
1508 * If this is a high priority I/O, then use the high priority taskq if
1511 if (zio
->io_priority
== ZIO_PRIORITY_NOW
&&
1512 spa
->spa_zio_taskq
[t
][q
+ 1].stqs_count
!= 0)
1515 ASSERT3U(q
, <, ZIO_TASKQ_TYPES
);
1518 * NB: We are assuming that the zio can only be dispatched
1519 * to a single taskq at a time. It would be a grievous error
1520 * to dispatch the zio to another taskq at the same time.
1522 ASSERT(zio
->io_tqent
.tqent_next
== NULL
);
1523 spa_taskq_dispatch_ent(spa
, t
, q
, (task_func_t
*)zio_execute
, zio
,
1524 flags
, &zio
->io_tqent
);
1528 zio_taskq_member(zio_t
*zio
, zio_taskq_type_t q
)
1530 kthread_t
*executor
= zio
->io_executor
;
1531 spa_t
*spa
= zio
->io_spa
;
1533 for (zio_type_t t
= 0; t
< ZIO_TYPES
; t
++) {
1534 spa_taskqs_t
*tqs
= &spa
->spa_zio_taskq
[t
][q
];
1536 for (i
= 0; i
< tqs
->stqs_count
; i
++) {
1537 if (taskq_member(tqs
->stqs_taskq
[i
], executor
))
1546 zio_issue_async(zio_t
*zio
)
1548 zio_taskq_dispatch(zio
, ZIO_TASKQ_ISSUE
, B_FALSE
);
1550 return (ZIO_PIPELINE_STOP
);
1554 zio_interrupt(zio_t
*zio
)
1556 zio_taskq_dispatch(zio
, ZIO_TASKQ_INTERRUPT
, B_FALSE
);
1560 zio_delay_interrupt(zio_t
*zio
)
1563 * The timeout_generic() function isn't defined in userspace, so
1564 * rather than trying to implement the function, the zio delay
1565 * functionality has been disabled for userspace builds.
1570 * If io_target_timestamp is zero, then no delay has been registered
1571 * for this IO, thus jump to the end of this function and "skip" the
1572 * delay; issuing it directly to the zio layer.
1574 if (zio
->io_target_timestamp
!= 0) {
1575 hrtime_t now
= gethrtime();
1577 if (now
>= zio
->io_target_timestamp
) {
1579 * This IO has already taken longer than the target
1580 * delay to complete, so we don't want to delay it
1581 * any longer; we "miss" the delay and issue it
1582 * directly to the zio layer. This is likely due to
1583 * the target latency being set to a value less than
1584 * the underlying hardware can satisfy (e.g. delay
1585 * set to 1ms, but the disks take 10ms to complete an
1589 DTRACE_PROBE2(zio__delay__miss
, zio_t
*, zio
,
1594 hrtime_t diff
= zio
->io_target_timestamp
- now
;
1596 DTRACE_PROBE3(zio__delay__hit
, zio_t
*, zio
,
1597 hrtime_t
, now
, hrtime_t
, diff
);
1599 (void) timeout_generic(CALLOUT_NORMAL
,
1600 (void (*)(void *))zio_interrupt
, zio
, diff
, 1, 0);
1607 DTRACE_PROBE1(zio__delay__skip
, zio_t
*, zio
);
1612 * Execute the I/O pipeline until one of the following occurs:
1614 * (1) the I/O completes
1615 * (2) the pipeline stalls waiting for dependent child I/Os
1616 * (3) the I/O issues, so we're waiting for an I/O completion interrupt
1617 * (4) the I/O is delegated by vdev-level caching or aggregation
1618 * (5) the I/O is deferred due to vdev-level queueing
1619 * (6) the I/O is handed off to another thread.
1621 * In all cases, the pipeline stops whenever there's no CPU work; it never
1622 * burns a thread in cv_wait().
1624 * There's no locking on io_stage because there's no legitimate way
1625 * for multiple threads to be attempting to process the same I/O.
1627 static zio_pipe_stage_t
*zio_pipeline
[];
1630 zio_execute(zio_t
*zio
)
1632 zio
->io_executor
= curthread
;
1634 ASSERT3U(zio
->io_queued_timestamp
, >, 0);
1636 while (zio
->io_stage
< ZIO_STAGE_DONE
) {
1637 enum zio_stage pipeline
= zio
->io_pipeline
;
1638 enum zio_stage stage
= zio
->io_stage
;
1641 ASSERT(!MUTEX_HELD(&zio
->io_lock
));
1642 ASSERT(ISP2(stage
));
1643 ASSERT(zio
->io_stall
== NULL
);
1647 } while ((stage
& pipeline
) == 0);
1649 ASSERT(stage
<= ZIO_STAGE_DONE
);
1652 * If we are in interrupt context and this pipeline stage
1653 * will grab a config lock that is held across I/O,
1654 * or may wait for an I/O that needs an interrupt thread
1655 * to complete, issue async to avoid deadlock.
1657 * For VDEV_IO_START, we cut in line so that the io will
1658 * be sent to disk promptly.
1660 if ((stage
& ZIO_BLOCKING_STAGES
) && zio
->io_vd
== NULL
&&
1661 zio_taskq_member(zio
, ZIO_TASKQ_INTERRUPT
)) {
1662 boolean_t cut
= (stage
== ZIO_STAGE_VDEV_IO_START
) ?
1663 zio_requeue_io_start_cut_in_line
: B_FALSE
;
1664 zio_taskq_dispatch(zio
, ZIO_TASKQ_ISSUE
, cut
);
1668 zio
->io_stage
= stage
;
1669 zio
->io_pipeline_trace
|= zio
->io_stage
;
1670 rv
= zio_pipeline
[highbit64(stage
) - 1](zio
);
1672 if (rv
== ZIO_PIPELINE_STOP
)
1675 ASSERT(rv
== ZIO_PIPELINE_CONTINUE
);
1680 * ==========================================================================
1681 * Initiate I/O, either sync or async
1682 * ==========================================================================
1685 zio_wait(zio_t
*zio
)
1689 ASSERT3P(zio
->io_stage
, ==, ZIO_STAGE_OPEN
);
1690 ASSERT3P(zio
->io_executor
, ==, NULL
);
1692 zio
->io_waiter
= curthread
;
1693 ASSERT0(zio
->io_queued_timestamp
);
1694 zio
->io_queued_timestamp
= gethrtime();
1698 mutex_enter(&zio
->io_lock
);
1699 while (zio
->io_executor
!= NULL
)
1700 cv_wait(&zio
->io_cv
, &zio
->io_lock
);
1701 mutex_exit(&zio
->io_lock
);
1703 error
= zio
->io_error
;
1710 zio_nowait(zio_t
*zio
)
1712 ASSERT3P(zio
->io_executor
, ==, NULL
);
1714 if (zio
->io_child_type
== ZIO_CHILD_LOGICAL
&&
1715 zio_unique_parent(zio
) == NULL
) {
1717 * This is a logical async I/O with no parent to wait for it.
1718 * We add it to the spa_async_root_zio "Godfather" I/O which
1719 * will ensure they complete prior to unloading the pool.
1721 spa_t
*spa
= zio
->io_spa
;
1723 zio_add_child(spa
->spa_async_zio_root
[CPU_SEQID
], zio
);
1726 ASSERT0(zio
->io_queued_timestamp
);
1727 zio
->io_queued_timestamp
= gethrtime();
1732 * ==========================================================================
1733 * Reexecute, cancel, or suspend/resume failed I/O
1734 * ==========================================================================
1738 zio_reexecute(zio_t
*pio
)
1740 zio_t
*cio
, *cio_next
;
1742 ASSERT(pio
->io_child_type
== ZIO_CHILD_LOGICAL
);
1743 ASSERT(pio
->io_orig_stage
== ZIO_STAGE_OPEN
);
1744 ASSERT(pio
->io_gang_leader
== NULL
);
1745 ASSERT(pio
->io_gang_tree
== NULL
);
1747 pio
->io_flags
= pio
->io_orig_flags
;
1748 pio
->io_stage
= pio
->io_orig_stage
;
1749 pio
->io_pipeline
= pio
->io_orig_pipeline
;
1750 pio
->io_reexecute
= 0;
1751 pio
->io_flags
|= ZIO_FLAG_REEXECUTED
;
1752 pio
->io_pipeline_trace
= 0;
1754 for (int w
= 0; w
< ZIO_WAIT_TYPES
; w
++)
1755 pio
->io_state
[w
] = 0;
1756 for (int c
= 0; c
< ZIO_CHILD_TYPES
; c
++)
1757 pio
->io_child_error
[c
] = 0;
1759 if (IO_IS_ALLOCATING(pio
))
1760 BP_ZERO(pio
->io_bp
);
1763 * As we reexecute pio's children, new children could be created.
1764 * New children go to the head of pio's io_child_list, however,
1765 * so we will (correctly) not reexecute them. The key is that
1766 * the remainder of pio's io_child_list, from 'cio_next' onward,
1767 * cannot be affected by any side effects of reexecuting 'cio'.
1769 zio_link_t
*zl
= NULL
;
1770 for (cio
= zio_walk_children(pio
, &zl
); cio
!= NULL
; cio
= cio_next
) {
1771 cio_next
= zio_walk_children(pio
, &zl
);
1772 mutex_enter(&pio
->io_lock
);
1773 for (int w
= 0; w
< ZIO_WAIT_TYPES
; w
++)
1774 pio
->io_children
[cio
->io_child_type
][w
]++;
1775 mutex_exit(&pio
->io_lock
);
1780 * Now that all children have been reexecuted, execute the parent.
1781 * We don't reexecute "The Godfather" I/O here as it's the
1782 * responsibility of the caller to wait on it.
1784 if (!(pio
->io_flags
& ZIO_FLAG_GODFATHER
)) {
1785 pio
->io_queued_timestamp
= gethrtime();
1791 zio_suspend(spa_t
*spa
, zio_t
*zio
)
1793 if (spa_get_failmode(spa
) == ZIO_FAILURE_MODE_PANIC
)
1794 fm_panic("Pool '%s' has encountered an uncorrectable I/O "
1795 "failure and the failure mode property for this pool "
1796 "is set to panic.", spa_name(spa
));
1798 zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE
, spa
, NULL
, NULL
, 0, 0);
1800 mutex_enter(&spa
->spa_suspend_lock
);
1802 if (spa
->spa_suspend_zio_root
== NULL
)
1803 spa
->spa_suspend_zio_root
= zio_root(spa
, NULL
, NULL
,
1804 ZIO_FLAG_CANFAIL
| ZIO_FLAG_SPECULATIVE
|
1805 ZIO_FLAG_GODFATHER
);
1807 spa
->spa_suspended
= B_TRUE
;
1810 ASSERT(!(zio
->io_flags
& ZIO_FLAG_GODFATHER
));
1811 ASSERT(zio
!= spa
->spa_suspend_zio_root
);
1812 ASSERT(zio
->io_child_type
== ZIO_CHILD_LOGICAL
);
1813 ASSERT(zio_unique_parent(zio
) == NULL
);
1814 ASSERT(zio
->io_stage
== ZIO_STAGE_DONE
);
1815 zio_add_child(spa
->spa_suspend_zio_root
, zio
);
1818 mutex_exit(&spa
->spa_suspend_lock
);
1822 zio_resume(spa_t
*spa
)
1827 * Reexecute all previously suspended i/o.
1829 mutex_enter(&spa
->spa_suspend_lock
);
1830 spa
->spa_suspended
= B_FALSE
;
1831 cv_broadcast(&spa
->spa_suspend_cv
);
1832 pio
= spa
->spa_suspend_zio_root
;
1833 spa
->spa_suspend_zio_root
= NULL
;
1834 mutex_exit(&spa
->spa_suspend_lock
);
1840 return (zio_wait(pio
));
1844 zio_resume_wait(spa_t
*spa
)
1846 mutex_enter(&spa
->spa_suspend_lock
);
1847 while (spa_suspended(spa
))
1848 cv_wait(&spa
->spa_suspend_cv
, &spa
->spa_suspend_lock
);
1849 mutex_exit(&spa
->spa_suspend_lock
);
1853 * ==========================================================================
1856 * A gang block is a collection of small blocks that looks to the DMU
1857 * like one large block. When zio_dva_allocate() cannot find a block
1858 * of the requested size, due to either severe fragmentation or the pool
1859 * being nearly full, it calls zio_write_gang_block() to construct the
1860 * block from smaller fragments.
1862 * A gang block consists of a gang header (zio_gbh_phys_t) and up to
1863 * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like
1864 * an indirect block: it's an array of block pointers. It consumes
1865 * only one sector and hence is allocatable regardless of fragmentation.
1866 * The gang header's bps point to its gang members, which hold the data.
1868 * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg>
1869 * as the verifier to ensure uniqueness of the SHA256 checksum.
1870 * Critically, the gang block bp's blk_cksum is the checksum of the data,
1871 * not the gang header. This ensures that data block signatures (needed for
1872 * deduplication) are independent of how the block is physically stored.
1874 * Gang blocks can be nested: a gang member may itself be a gang block.
1875 * Thus every gang block is a tree in which root and all interior nodes are
1876 * gang headers, and the leaves are normal blocks that contain user data.
1877 * The root of the gang tree is called the gang leader.
1879 * To perform any operation (read, rewrite, free, claim) on a gang block,
1880 * zio_gang_assemble() first assembles the gang tree (minus data leaves)
1881 * in the io_gang_tree field of the original logical i/o by recursively
1882 * reading the gang leader and all gang headers below it. This yields
1883 * an in-core tree containing the contents of every gang header and the
1884 * bps for every constituent of the gang block.
1886 * With the gang tree now assembled, zio_gang_issue() just walks the gang tree
1887 * and invokes a callback on each bp. To free a gang block, zio_gang_issue()
1888 * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp.
1889 * zio_claim_gang() provides a similarly trivial wrapper for zio_claim().
1890 * zio_read_gang() is a wrapper around zio_read() that omits reading gang
1891 * headers, since we already have those in io_gang_tree. zio_rewrite_gang()
1892 * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite()
1893 * of the gang header plus zio_checksum_compute() of the data to update the
1894 * gang header's blk_cksum as described above.
1896 * The two-phase assemble/issue model solves the problem of partial failure --
1897 * what if you'd freed part of a gang block but then couldn't read the
1898 * gang header for another part? Assembling the entire gang tree first
1899 * ensures that all the necessary gang header I/O has succeeded before
1900 * starting the actual work of free, claim, or write. Once the gang tree
1901 * is assembled, free and claim are in-memory operations that cannot fail.
1903 * In the event that a gang write fails, zio_dva_unallocate() walks the
1904 * gang tree to immediately free (i.e. insert back into the space map)
1905 * everything we've allocated. This ensures that we don't get ENOSPC
1906 * errors during repeated suspend/resume cycles due to a flaky device.
1908 * Gang rewrites only happen during sync-to-convergence. If we can't assemble
1909 * the gang tree, we won't modify the block, so we can safely defer the free
1910 * (knowing that the block is still intact). If we *can* assemble the gang
1911 * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free
1912 * each constituent bp and we can allocate a new block on the next sync pass.
1914 * In all cases, the gang tree allows complete recovery from partial failure.
1915 * ==========================================================================
1919 zio_gang_issue_func_done(zio_t
*zio
)
1921 abd_put(zio
->io_abd
);
1925 zio_read_gang(zio_t
*pio
, blkptr_t
*bp
, zio_gang_node_t
*gn
, abd_t
*data
,
1931 return (zio_read(pio
, pio
->io_spa
, bp
, abd_get_offset(data
, offset
),
1932 BP_GET_PSIZE(bp
), zio_gang_issue_func_done
,
1933 NULL
, pio
->io_priority
, ZIO_GANG_CHILD_FLAGS(pio
),
1934 &pio
->io_bookmark
));
1938 zio_rewrite_gang(zio_t
*pio
, blkptr_t
*bp
, zio_gang_node_t
*gn
, abd_t
*data
,
1945 abd_get_from_buf(gn
->gn_gbh
, SPA_GANGBLOCKSIZE
);
1946 zio
= zio_rewrite(pio
, pio
->io_spa
, pio
->io_txg
, bp
,
1947 gbh_abd
, SPA_GANGBLOCKSIZE
, zio_gang_issue_func_done
, NULL
,
1948 pio
->io_priority
, ZIO_GANG_CHILD_FLAGS(pio
),
1951 * As we rewrite each gang header, the pipeline will compute
1952 * a new gang block header checksum for it; but no one will
1953 * compute a new data checksum, so we do that here. The one
1954 * exception is the gang leader: the pipeline already computed
1955 * its data checksum because that stage precedes gang assembly.
1956 * (Presently, nothing actually uses interior data checksums;
1957 * this is just good hygiene.)
1959 if (gn
!= pio
->io_gang_leader
->io_gang_tree
) {
1960 abd_t
*buf
= abd_get_offset(data
, offset
);
1962 zio_checksum_compute(zio
, BP_GET_CHECKSUM(bp
),
1963 buf
, BP_GET_PSIZE(bp
));
1968 * If we are here to damage data for testing purposes,
1969 * leave the GBH alone so that we can detect the damage.
1971 if (pio
->io_gang_leader
->io_flags
& ZIO_FLAG_INDUCE_DAMAGE
)
1972 zio
->io_pipeline
&= ~ZIO_VDEV_IO_STAGES
;
1974 zio
= zio_rewrite(pio
, pio
->io_spa
, pio
->io_txg
, bp
,
1975 abd_get_offset(data
, offset
), BP_GET_PSIZE(bp
),
1976 zio_gang_issue_func_done
, NULL
, pio
->io_priority
,
1977 ZIO_GANG_CHILD_FLAGS(pio
), &pio
->io_bookmark
);
1985 zio_free_gang(zio_t
*pio
, blkptr_t
*bp
, zio_gang_node_t
*gn
, abd_t
*data
,
1988 return (zio_free_sync(pio
, pio
->io_spa
, pio
->io_txg
, bp
,
1989 ZIO_GANG_CHILD_FLAGS(pio
)));
1994 zio_claim_gang(zio_t
*pio
, blkptr_t
*bp
, zio_gang_node_t
*gn
, abd_t
*data
,
1997 return (zio_claim(pio
, pio
->io_spa
, pio
->io_txg
, bp
,
1998 NULL
, NULL
, ZIO_GANG_CHILD_FLAGS(pio
)));
2001 static zio_gang_issue_func_t
*zio_gang_issue_func
[ZIO_TYPES
] = {
2010 static void zio_gang_tree_assemble_done(zio_t
*zio
);
2012 static zio_gang_node_t
*
2013 zio_gang_node_alloc(zio_gang_node_t
**gnpp
)
2015 zio_gang_node_t
*gn
;
2017 ASSERT(*gnpp
== NULL
);
2019 gn
= kmem_zalloc(sizeof (*gn
), KM_SLEEP
);
2020 gn
->gn_gbh
= zio_buf_alloc(SPA_GANGBLOCKSIZE
);
2027 zio_gang_node_free(zio_gang_node_t
**gnpp
)
2029 zio_gang_node_t
*gn
= *gnpp
;
2031 for (int g
= 0; g
< SPA_GBH_NBLKPTRS
; g
++)
2032 ASSERT(gn
->gn_child
[g
] == NULL
);
2034 zio_buf_free(gn
->gn_gbh
, SPA_GANGBLOCKSIZE
);
2035 kmem_free(gn
, sizeof (*gn
));
2040 zio_gang_tree_free(zio_gang_node_t
**gnpp
)
2042 zio_gang_node_t
*gn
= *gnpp
;
2047 for (int g
= 0; g
< SPA_GBH_NBLKPTRS
; g
++)
2048 zio_gang_tree_free(&gn
->gn_child
[g
]);
2050 zio_gang_node_free(gnpp
);
2054 zio_gang_tree_assemble(zio_t
*gio
, blkptr_t
*bp
, zio_gang_node_t
**gnpp
)
2056 zio_gang_node_t
*gn
= zio_gang_node_alloc(gnpp
);
2057 abd_t
*gbh_abd
= abd_get_from_buf(gn
->gn_gbh
, SPA_GANGBLOCKSIZE
);
2059 ASSERT(gio
->io_gang_leader
== gio
);
2060 ASSERT(BP_IS_GANG(bp
));
2062 zio_nowait(zio_read(gio
, gio
->io_spa
, bp
, gbh_abd
, SPA_GANGBLOCKSIZE
,
2063 zio_gang_tree_assemble_done
, gn
, gio
->io_priority
,
2064 ZIO_GANG_CHILD_FLAGS(gio
), &gio
->io_bookmark
));
2068 zio_gang_tree_assemble_done(zio_t
*zio
)
2070 zio_t
*gio
= zio
->io_gang_leader
;
2071 zio_gang_node_t
*gn
= zio
->io_private
;
2072 blkptr_t
*bp
= zio
->io_bp
;
2074 ASSERT(gio
== zio_unique_parent(zio
));
2075 ASSERT(zio
->io_child_count
== 0);
2080 /* this ABD was created from a linear buf in zio_gang_tree_assemble */
2081 if (BP_SHOULD_BYTESWAP(bp
))
2082 byteswap_uint64_array(abd_to_buf(zio
->io_abd
), zio
->io_size
);
2084 ASSERT3P(abd_to_buf(zio
->io_abd
), ==, gn
->gn_gbh
);
2085 ASSERT(zio
->io_size
== SPA_GANGBLOCKSIZE
);
2086 ASSERT(gn
->gn_gbh
->zg_tail
.zec_magic
== ZEC_MAGIC
);
2088 abd_put(zio
->io_abd
);
2090 for (int g
= 0; g
< SPA_GBH_NBLKPTRS
; g
++) {
2091 blkptr_t
*gbp
= &gn
->gn_gbh
->zg_blkptr
[g
];
2092 if (!BP_IS_GANG(gbp
))
2094 zio_gang_tree_assemble(gio
, gbp
, &gn
->gn_child
[g
]);
2099 zio_gang_tree_issue(zio_t
*pio
, zio_gang_node_t
*gn
, blkptr_t
*bp
, abd_t
*data
,
2102 zio_t
*gio
= pio
->io_gang_leader
;
2105 ASSERT(BP_IS_GANG(bp
) == !!gn
);
2106 ASSERT(BP_GET_CHECKSUM(bp
) == BP_GET_CHECKSUM(gio
->io_bp
));
2107 ASSERT(BP_GET_LSIZE(bp
) == BP_GET_PSIZE(bp
) || gn
== gio
->io_gang_tree
);
2110 * If you're a gang header, your data is in gn->gn_gbh.
2111 * If you're a gang member, your data is in 'data' and gn == NULL.
2113 zio
= zio_gang_issue_func
[gio
->io_type
](pio
, bp
, gn
, data
, offset
);
2116 ASSERT(gn
->gn_gbh
->zg_tail
.zec_magic
== ZEC_MAGIC
);
2118 for (int g
= 0; g
< SPA_GBH_NBLKPTRS
; g
++) {
2119 blkptr_t
*gbp
= &gn
->gn_gbh
->zg_blkptr
[g
];
2120 if (BP_IS_HOLE(gbp
))
2122 zio_gang_tree_issue(zio
, gn
->gn_child
[g
], gbp
, data
,
2124 offset
+= BP_GET_PSIZE(gbp
);
2128 if (gn
== gio
->io_gang_tree
)
2129 ASSERT3U(gio
->io_size
, ==, offset
);
2136 zio_gang_assemble(zio_t
*zio
)
2138 blkptr_t
*bp
= zio
->io_bp
;
2140 ASSERT(BP_IS_GANG(bp
) && zio
->io_gang_leader
== NULL
);
2141 ASSERT(zio
->io_child_type
> ZIO_CHILD_GANG
);
2143 zio
->io_gang_leader
= zio
;
2145 zio_gang_tree_assemble(zio
, bp
, &zio
->io_gang_tree
);
2147 return (ZIO_PIPELINE_CONTINUE
);
2151 zio_gang_issue(zio_t
*zio
)
2153 blkptr_t
*bp
= zio
->io_bp
;
2155 if (zio_wait_for_children(zio
, ZIO_CHILD_GANG_BIT
, ZIO_WAIT_DONE
)) {
2156 return (ZIO_PIPELINE_STOP
);
2159 ASSERT(BP_IS_GANG(bp
) && zio
->io_gang_leader
== zio
);
2160 ASSERT(zio
->io_child_type
> ZIO_CHILD_GANG
);
2162 if (zio
->io_child_error
[ZIO_CHILD_GANG
] == 0)
2163 zio_gang_tree_issue(zio
, zio
->io_gang_tree
, bp
, zio
->io_abd
,
2166 zio_gang_tree_free(&zio
->io_gang_tree
);
2168 zio
->io_pipeline
= ZIO_INTERLOCK_PIPELINE
;
2170 return (ZIO_PIPELINE_CONTINUE
);
2174 zio_write_gang_member_ready(zio_t
*zio
)
2176 zio_t
*pio
= zio_unique_parent(zio
);
2177 zio_t
*gio
= zio
->io_gang_leader
;
2178 dva_t
*cdva
= zio
->io_bp
->blk_dva
;
2179 dva_t
*pdva
= pio
->io_bp
->blk_dva
;
2182 if (BP_IS_HOLE(zio
->io_bp
))
2185 ASSERT(BP_IS_HOLE(&zio
->io_bp_orig
));
2187 ASSERT(zio
->io_child_type
== ZIO_CHILD_GANG
);
2188 ASSERT3U(zio
->io_prop
.zp_copies
, ==, gio
->io_prop
.zp_copies
);
2189 ASSERT3U(zio
->io_prop
.zp_copies
, <=, BP_GET_NDVAS(zio
->io_bp
));
2190 ASSERT3U(pio
->io_prop
.zp_copies
, <=, BP_GET_NDVAS(pio
->io_bp
));
2191 ASSERT3U(BP_GET_NDVAS(zio
->io_bp
), <=, BP_GET_NDVAS(pio
->io_bp
));
2193 mutex_enter(&pio
->io_lock
);
2194 for (int d
= 0; d
< BP_GET_NDVAS(zio
->io_bp
); d
++) {
2195 ASSERT(DVA_GET_GANG(&pdva
[d
]));
2196 asize
= DVA_GET_ASIZE(&pdva
[d
]);
2197 asize
+= DVA_GET_ASIZE(&cdva
[d
]);
2198 DVA_SET_ASIZE(&pdva
[d
], asize
);
2200 mutex_exit(&pio
->io_lock
);
2204 zio_write_gang_done(zio_t
*zio
)
2206 abd_put(zio
->io_abd
);
2210 zio_write_gang_block(zio_t
*pio
)
2212 spa_t
*spa
= pio
->io_spa
;
2213 metaslab_class_t
*mc
= spa_normal_class(spa
);
2214 blkptr_t
*bp
= pio
->io_bp
;
2215 zio_t
*gio
= pio
->io_gang_leader
;
2217 zio_gang_node_t
*gn
, **gnpp
;
2218 zio_gbh_phys_t
*gbh
;
2220 uint64_t txg
= pio
->io_txg
;
2221 uint64_t resid
= pio
->io_size
;
2223 int copies
= gio
->io_prop
.zp_copies
;
2224 int gbh_copies
= MIN(copies
+ 1, spa_max_replication(spa
));
2228 int flags
= METASLAB_HINTBP_FAVOR
| METASLAB_GANG_HEADER
;
2229 if (pio
->io_flags
& ZIO_FLAG_IO_ALLOCATING
) {
2230 ASSERT(pio
->io_priority
== ZIO_PRIORITY_ASYNC_WRITE
);
2231 ASSERT(!(pio
->io_flags
& ZIO_FLAG_NODATA
));
2233 flags
|= METASLAB_ASYNC_ALLOC
;
2234 VERIFY(refcount_held(&mc
->mc_alloc_slots
[pio
->io_allocator
],
2238 * The logical zio has already placed a reservation for
2239 * 'copies' allocation slots but gang blocks may require
2240 * additional copies. These additional copies
2241 * (i.e. gbh_copies - copies) are guaranteed to succeed
2242 * since metaslab_class_throttle_reserve() always allows
2243 * additional reservations for gang blocks.
2245 VERIFY(metaslab_class_throttle_reserve(mc
, gbh_copies
- copies
,
2246 pio
->io_allocator
, pio
, flags
));
2249 error
= metaslab_alloc(spa
, mc
, SPA_GANGBLOCKSIZE
,
2250 bp
, gbh_copies
, txg
, pio
== gio
? NULL
: gio
->io_bp
, flags
,
2251 &pio
->io_alloc_list
, pio
, pio
->io_allocator
);
2253 if (pio
->io_flags
& ZIO_FLAG_IO_ALLOCATING
) {
2254 ASSERT(pio
->io_priority
== ZIO_PRIORITY_ASYNC_WRITE
);
2255 ASSERT(!(pio
->io_flags
& ZIO_FLAG_NODATA
));
2258 * If we failed to allocate the gang block header then
2259 * we remove any additional allocation reservations that
2260 * we placed here. The original reservation will
2261 * be removed when the logical I/O goes to the ready
2264 metaslab_class_throttle_unreserve(mc
,
2265 gbh_copies
- copies
, pio
->io_allocator
, pio
);
2267 pio
->io_error
= error
;
2268 return (ZIO_PIPELINE_CONTINUE
);
2272 gnpp
= &gio
->io_gang_tree
;
2274 gnpp
= pio
->io_private
;
2275 ASSERT(pio
->io_ready
== zio_write_gang_member_ready
);
2278 gn
= zio_gang_node_alloc(gnpp
);
2280 bzero(gbh
, SPA_GANGBLOCKSIZE
);
2281 gbh_abd
= abd_get_from_buf(gbh
, SPA_GANGBLOCKSIZE
);
2284 * Create the gang header.
2286 zio
= zio_rewrite(pio
, spa
, txg
, bp
, gbh_abd
, SPA_GANGBLOCKSIZE
,
2287 zio_write_gang_done
, NULL
, pio
->io_priority
,
2288 ZIO_GANG_CHILD_FLAGS(pio
), &pio
->io_bookmark
);
2291 * Create and nowait the gang children.
2293 for (int g
= 0; resid
!= 0; resid
-= lsize
, g
++) {
2294 lsize
= P2ROUNDUP(resid
/ (SPA_GBH_NBLKPTRS
- g
),
2296 ASSERT(lsize
>= SPA_MINBLOCKSIZE
&& lsize
<= resid
);
2298 zp
.zp_checksum
= gio
->io_prop
.zp_checksum
;
2299 zp
.zp_compress
= ZIO_COMPRESS_OFF
;
2300 zp
.zp_type
= DMU_OT_NONE
;
2302 zp
.zp_copies
= gio
->io_prop
.zp_copies
;
2303 zp
.zp_dedup
= B_FALSE
;
2304 zp
.zp_dedup_verify
= B_FALSE
;
2305 zp
.zp_nopwrite
= B_FALSE
;
2307 zio_t
*cio
= zio_write(zio
, spa
, txg
, &gbh
->zg_blkptr
[g
],
2308 abd_get_offset(pio
->io_abd
, pio
->io_size
- resid
), lsize
,
2309 lsize
, &zp
, zio_write_gang_member_ready
, NULL
, NULL
,
2310 zio_write_gang_done
, &gn
->gn_child
[g
], pio
->io_priority
,
2311 ZIO_GANG_CHILD_FLAGS(pio
), &pio
->io_bookmark
);
2313 if (pio
->io_flags
& ZIO_FLAG_IO_ALLOCATING
) {
2314 ASSERT(pio
->io_priority
== ZIO_PRIORITY_ASYNC_WRITE
);
2315 ASSERT(!(pio
->io_flags
& ZIO_FLAG_NODATA
));
2318 * Gang children won't throttle but we should
2319 * account for their work, so reserve an allocation
2320 * slot for them here.
2322 VERIFY(metaslab_class_throttle_reserve(mc
,
2323 zp
.zp_copies
, cio
->io_allocator
, cio
, flags
));
2329 * Set pio's pipeline to just wait for zio to finish.
2331 pio
->io_pipeline
= ZIO_INTERLOCK_PIPELINE
;
2335 return (ZIO_PIPELINE_CONTINUE
);
2339 * The zio_nop_write stage in the pipeline determines if allocating a
2340 * new bp is necessary. The nopwrite feature can handle writes in
2341 * either syncing or open context (i.e. zil writes) and as a result is
2342 * mutually exclusive with dedup.
2344 * By leveraging a cryptographically secure checksum, such as SHA256, we
2345 * can compare the checksums of the new data and the old to determine if
2346 * allocating a new block is required. Note that our requirements for
2347 * cryptographic strength are fairly weak: there can't be any accidental
2348 * hash collisions, but we don't need to be secure against intentional
2349 * (malicious) collisions. To trigger a nopwrite, you have to be able
2350 * to write the file to begin with, and triggering an incorrect (hash
2351 * collision) nopwrite is no worse than simply writing to the file.
2352 * That said, there are no known attacks against the checksum algorithms
2353 * used for nopwrite, assuming that the salt and the checksums
2354 * themselves remain secret.
2357 zio_nop_write(zio_t
*zio
)
2359 blkptr_t
*bp
= zio
->io_bp
;
2360 blkptr_t
*bp_orig
= &zio
->io_bp_orig
;
2361 zio_prop_t
*zp
= &zio
->io_prop
;
2363 ASSERT(BP_GET_LEVEL(bp
) == 0);
2364 ASSERT(!(zio
->io_flags
& ZIO_FLAG_IO_REWRITE
));
2365 ASSERT(zp
->zp_nopwrite
);
2366 ASSERT(!zp
->zp_dedup
);
2367 ASSERT(zio
->io_bp_override
== NULL
);
2368 ASSERT(IO_IS_ALLOCATING(zio
));
2371 * Check to see if the original bp and the new bp have matching
2372 * characteristics (i.e. same checksum, compression algorithms, etc).
2373 * If they don't then just continue with the pipeline which will
2374 * allocate a new bp.
2376 if (BP_IS_HOLE(bp_orig
) ||
2377 !(zio_checksum_table
[BP_GET_CHECKSUM(bp
)].ci_flags
&
2378 ZCHECKSUM_FLAG_NOPWRITE
) ||
2379 BP_GET_CHECKSUM(bp
) != BP_GET_CHECKSUM(bp_orig
) ||
2380 BP_GET_COMPRESS(bp
) != BP_GET_COMPRESS(bp_orig
) ||
2381 BP_GET_DEDUP(bp
) != BP_GET_DEDUP(bp_orig
) ||
2382 zp
->zp_copies
!= BP_GET_NDVAS(bp_orig
))
2383 return (ZIO_PIPELINE_CONTINUE
);
2386 * If the checksums match then reset the pipeline so that we
2387 * avoid allocating a new bp and issuing any I/O.
2389 if (ZIO_CHECKSUM_EQUAL(bp
->blk_cksum
, bp_orig
->blk_cksum
)) {
2390 ASSERT(zio_checksum_table
[zp
->zp_checksum
].ci_flags
&
2391 ZCHECKSUM_FLAG_NOPWRITE
);
2392 ASSERT3U(BP_GET_PSIZE(bp
), ==, BP_GET_PSIZE(bp_orig
));
2393 ASSERT3U(BP_GET_LSIZE(bp
), ==, BP_GET_LSIZE(bp_orig
));
2394 ASSERT(zp
->zp_compress
!= ZIO_COMPRESS_OFF
);
2395 ASSERT(bcmp(&bp
->blk_prop
, &bp_orig
->blk_prop
,
2396 sizeof (uint64_t)) == 0);
2399 zio
->io_pipeline
= ZIO_INTERLOCK_PIPELINE
;
2400 zio
->io_flags
|= ZIO_FLAG_NOPWRITE
;
2403 return (ZIO_PIPELINE_CONTINUE
);
2407 * ==========================================================================
2409 * ==========================================================================
2412 zio_ddt_child_read_done(zio_t
*zio
)
2414 blkptr_t
*bp
= zio
->io_bp
;
2415 ddt_entry_t
*dde
= zio
->io_private
;
2417 zio_t
*pio
= zio_unique_parent(zio
);
2419 mutex_enter(&pio
->io_lock
);
2420 ddp
= ddt_phys_select(dde
, bp
);
2421 if (zio
->io_error
== 0)
2422 ddt_phys_clear(ddp
); /* this ddp doesn't need repair */
2424 if (zio
->io_error
== 0 && dde
->dde_repair_abd
== NULL
)
2425 dde
->dde_repair_abd
= zio
->io_abd
;
2427 abd_free(zio
->io_abd
);
2428 mutex_exit(&pio
->io_lock
);
2432 zio_ddt_read_start(zio_t
*zio
)
2434 blkptr_t
*bp
= zio
->io_bp
;
2436 ASSERT(BP_GET_DEDUP(bp
));
2437 ASSERT(BP_GET_PSIZE(bp
) == zio
->io_size
);
2438 ASSERT(zio
->io_child_type
== ZIO_CHILD_LOGICAL
);
2440 if (zio
->io_child_error
[ZIO_CHILD_DDT
]) {
2441 ddt_t
*ddt
= ddt_select(zio
->io_spa
, bp
);
2442 ddt_entry_t
*dde
= ddt_repair_start(ddt
, bp
);
2443 ddt_phys_t
*ddp
= dde
->dde_phys
;
2444 ddt_phys_t
*ddp_self
= ddt_phys_select(dde
, bp
);
2447 ASSERT(zio
->io_vsd
== NULL
);
2450 if (ddp_self
== NULL
)
2451 return (ZIO_PIPELINE_CONTINUE
);
2453 for (int p
= 0; p
< DDT_PHYS_TYPES
; p
++, ddp
++) {
2454 if (ddp
->ddp_phys_birth
== 0 || ddp
== ddp_self
)
2456 ddt_bp_create(ddt
->ddt_checksum
, &dde
->dde_key
, ddp
,
2458 zio_nowait(zio_read(zio
, zio
->io_spa
, &blk
,
2459 abd_alloc_for_io(zio
->io_size
, B_TRUE
),
2460 zio
->io_size
, zio_ddt_child_read_done
, dde
,
2461 zio
->io_priority
, ZIO_DDT_CHILD_FLAGS(zio
) |
2462 ZIO_FLAG_DONT_PROPAGATE
, &zio
->io_bookmark
));
2464 return (ZIO_PIPELINE_CONTINUE
);
2467 zio_nowait(zio_read(zio
, zio
->io_spa
, bp
,
2468 zio
->io_abd
, zio
->io_size
, NULL
, NULL
, zio
->io_priority
,
2469 ZIO_DDT_CHILD_FLAGS(zio
), &zio
->io_bookmark
));
2471 return (ZIO_PIPELINE_CONTINUE
);
2475 zio_ddt_read_done(zio_t
*zio
)
2477 blkptr_t
*bp
= zio
->io_bp
;
2479 if (zio_wait_for_children(zio
, ZIO_CHILD_DDT_BIT
, ZIO_WAIT_DONE
)) {
2480 return (ZIO_PIPELINE_STOP
);
2483 ASSERT(BP_GET_DEDUP(bp
));
2484 ASSERT(BP_GET_PSIZE(bp
) == zio
->io_size
);
2485 ASSERT(zio
->io_child_type
== ZIO_CHILD_LOGICAL
);
2487 if (zio
->io_child_error
[ZIO_CHILD_DDT
]) {
2488 ddt_t
*ddt
= ddt_select(zio
->io_spa
, bp
);
2489 ddt_entry_t
*dde
= zio
->io_vsd
;
2491 ASSERT(spa_load_state(zio
->io_spa
) != SPA_LOAD_NONE
);
2492 return (ZIO_PIPELINE_CONTINUE
);
2495 zio
->io_stage
= ZIO_STAGE_DDT_READ_START
>> 1;
2496 zio_taskq_dispatch(zio
, ZIO_TASKQ_ISSUE
, B_FALSE
);
2497 return (ZIO_PIPELINE_STOP
);
2499 if (dde
->dde_repair_abd
!= NULL
) {
2500 abd_copy(zio
->io_abd
, dde
->dde_repair_abd
,
2502 zio
->io_child_error
[ZIO_CHILD_DDT
] = 0;
2504 ddt_repair_done(ddt
, dde
);
2508 ASSERT(zio
->io_vsd
== NULL
);
2510 return (ZIO_PIPELINE_CONTINUE
);
2514 zio_ddt_collision(zio_t
*zio
, ddt_t
*ddt
, ddt_entry_t
*dde
)
2516 spa_t
*spa
= zio
->io_spa
;
2517 boolean_t do_raw
= (zio
->io_flags
& ZIO_FLAG_RAW
);
2519 /* We should never get a raw, override zio */
2520 ASSERT(!(zio
->io_bp_override
&& do_raw
));
2523 * Note: we compare the original data, not the transformed data,
2524 * because when zio->io_bp is an override bp, we will not have
2525 * pushed the I/O transforms. That's an important optimization
2526 * because otherwise we'd compress/encrypt all dmu_sync() data twice.
2528 for (int p
= DDT_PHYS_SINGLE
; p
<= DDT_PHYS_TRIPLE
; p
++) {
2529 zio_t
*lio
= dde
->dde_lead_zio
[p
];
2532 return (lio
->io_orig_size
!= zio
->io_orig_size
||
2533 abd_cmp(zio
->io_orig_abd
, lio
->io_orig_abd
,
2534 zio
->io_orig_size
) != 0);
2538 for (int p
= DDT_PHYS_SINGLE
; p
<= DDT_PHYS_TRIPLE
; p
++) {
2539 ddt_phys_t
*ddp
= &dde
->dde_phys
[p
];
2541 if (ddp
->ddp_phys_birth
!= 0) {
2542 arc_buf_t
*abuf
= NULL
;
2543 arc_flags_t aflags
= ARC_FLAG_WAIT
;
2544 int zio_flags
= ZIO_FLAG_CANFAIL
| ZIO_FLAG_SPECULATIVE
;
2545 blkptr_t blk
= *zio
->io_bp
;
2548 ddt_bp_fill(ddp
, &blk
, ddp
->ddp_phys_birth
);
2553 * Intuitively, it would make more sense to compare
2554 * io_abd than io_orig_abd in the raw case since you
2555 * don't want to look at any transformations that have
2556 * happened to the data. However, for raw I/Os the
2557 * data will actually be the same in io_abd and
2558 * io_orig_abd, so all we have to do is issue this as
2562 zio_flags
|= ZIO_FLAG_RAW
;
2563 ASSERT3U(zio
->io_size
, ==, zio
->io_orig_size
);
2564 ASSERT0(abd_cmp(zio
->io_abd
, zio
->io_orig_abd
,
2566 ASSERT3P(zio
->io_transform_stack
, ==, NULL
);
2569 error
= arc_read(NULL
, spa
, &blk
,
2570 arc_getbuf_func
, &abuf
, ZIO_PRIORITY_SYNC_READ
,
2571 zio_flags
, &aflags
, &zio
->io_bookmark
);
2574 if (arc_buf_size(abuf
) != zio
->io_orig_size
||
2575 abd_cmp_buf(zio
->io_orig_abd
, abuf
->b_data
,
2576 zio
->io_orig_size
) != 0)
2577 error
= SET_ERROR(EEXIST
);
2578 arc_buf_destroy(abuf
, &abuf
);
2582 return (error
!= 0);
2590 zio_ddt_child_write_ready(zio_t
*zio
)
2592 int p
= zio
->io_prop
.zp_copies
;
2593 ddt_t
*ddt
= ddt_select(zio
->io_spa
, zio
->io_bp
);
2594 ddt_entry_t
*dde
= zio
->io_private
;
2595 ddt_phys_t
*ddp
= &dde
->dde_phys
[p
];
2603 ASSERT(dde
->dde_lead_zio
[p
] == zio
);
2605 ddt_phys_fill(ddp
, zio
->io_bp
);
2607 zio_link_t
*zl
= NULL
;
2608 while ((pio
= zio_walk_parents(zio
, &zl
)) != NULL
)
2609 ddt_bp_fill(ddp
, pio
->io_bp
, zio
->io_txg
);
2615 zio_ddt_child_write_done(zio_t
*zio
)
2617 int p
= zio
->io_prop
.zp_copies
;
2618 ddt_t
*ddt
= ddt_select(zio
->io_spa
, zio
->io_bp
);
2619 ddt_entry_t
*dde
= zio
->io_private
;
2620 ddt_phys_t
*ddp
= &dde
->dde_phys
[p
];
2624 ASSERT(ddp
->ddp_refcnt
== 0);
2625 ASSERT(dde
->dde_lead_zio
[p
] == zio
);
2626 dde
->dde_lead_zio
[p
] = NULL
;
2628 if (zio
->io_error
== 0) {
2629 zio_link_t
*zl
= NULL
;
2630 while (zio_walk_parents(zio
, &zl
) != NULL
)
2631 ddt_phys_addref(ddp
);
2633 ddt_phys_clear(ddp
);
2640 zio_ddt_ditto_write_done(zio_t
*zio
)
2642 int p
= DDT_PHYS_DITTO
;
2643 zio_prop_t
*zp
= &zio
->io_prop
;
2644 blkptr_t
*bp
= zio
->io_bp
;
2645 ddt_t
*ddt
= ddt_select(zio
->io_spa
, bp
);
2646 ddt_entry_t
*dde
= zio
->io_private
;
2647 ddt_phys_t
*ddp
= &dde
->dde_phys
[p
];
2648 ddt_key_t
*ddk
= &dde
->dde_key
;
2652 ASSERT(ddp
->ddp_refcnt
== 0);
2653 ASSERT(dde
->dde_lead_zio
[p
] == zio
);
2654 dde
->dde_lead_zio
[p
] = NULL
;
2656 if (zio
->io_error
== 0) {
2657 ASSERT(ZIO_CHECKSUM_EQUAL(bp
->blk_cksum
, ddk
->ddk_cksum
));
2658 ASSERT(zp
->zp_copies
< SPA_DVAS_PER_BP
);
2659 ASSERT(zp
->zp_copies
== BP_GET_NDVAS(bp
) - BP_IS_GANG(bp
));
2660 if (ddp
->ddp_phys_birth
!= 0)
2661 ddt_phys_free(ddt
, ddk
, ddp
, zio
->io_txg
);
2662 ddt_phys_fill(ddp
, bp
);
2669 zio_ddt_write(zio_t
*zio
)
2671 spa_t
*spa
= zio
->io_spa
;
2672 blkptr_t
*bp
= zio
->io_bp
;
2673 uint64_t txg
= zio
->io_txg
;
2674 zio_prop_t
*zp
= &zio
->io_prop
;
2675 int p
= zp
->zp_copies
;
2679 ddt_t
*ddt
= ddt_select(spa
, bp
);
2683 ASSERT(BP_GET_DEDUP(bp
));
2684 ASSERT(BP_GET_CHECKSUM(bp
) == zp
->zp_checksum
);
2685 ASSERT(BP_IS_HOLE(bp
) || zio
->io_bp_override
);
2686 ASSERT(!(zio
->io_bp_override
&& (zio
->io_flags
& ZIO_FLAG_RAW
)));
2689 dde
= ddt_lookup(ddt
, bp
, B_TRUE
);
2690 ddp
= &dde
->dde_phys
[p
];
2692 if (zp
->zp_dedup_verify
&& zio_ddt_collision(zio
, ddt
, dde
)) {
2694 * If we're using a weak checksum, upgrade to a strong checksum
2695 * and try again. If we're already using a strong checksum,
2696 * we can't resolve it, so just convert to an ordinary write.
2697 * (And automatically e-mail a paper to Nature?)
2699 if (!(zio_checksum_table
[zp
->zp_checksum
].ci_flags
&
2700 ZCHECKSUM_FLAG_DEDUP
)) {
2701 zp
->zp_checksum
= spa_dedup_checksum(spa
);
2702 zio_pop_transforms(zio
);
2703 zio
->io_stage
= ZIO_STAGE_OPEN
;
2706 zp
->zp_dedup
= B_FALSE
;
2707 BP_SET_DEDUP(bp
, B_FALSE
);
2709 ASSERT(!BP_GET_DEDUP(bp
));
2710 zio
->io_pipeline
= ZIO_WRITE_PIPELINE
;
2712 return (ZIO_PIPELINE_CONTINUE
);
2715 ditto_copies
= ddt_ditto_copies_needed(ddt
, dde
, ddp
);
2716 ASSERT(ditto_copies
< SPA_DVAS_PER_BP
);
2718 if (ditto_copies
> ddt_ditto_copies_present(dde
) &&
2719 dde
->dde_lead_zio
[DDT_PHYS_DITTO
] == NULL
) {
2720 zio_prop_t czp
= *zp
;
2722 czp
.zp_copies
= ditto_copies
;
2725 * If we arrived here with an override bp, we won't have run
2726 * the transform stack, so we won't have the data we need to
2727 * generate a child i/o. So, toss the override bp and restart.
2728 * This is safe, because using the override bp is just an
2729 * optimization; and it's rare, so the cost doesn't matter.
2731 if (zio
->io_bp_override
) {
2732 zio_pop_transforms(zio
);
2733 zio
->io_stage
= ZIO_STAGE_OPEN
;
2734 zio
->io_pipeline
= ZIO_WRITE_PIPELINE
;
2735 zio
->io_bp_override
= NULL
;
2738 return (ZIO_PIPELINE_CONTINUE
);
2741 dio
= zio_write(zio
, spa
, txg
, bp
, zio
->io_orig_abd
,
2742 zio
->io_orig_size
, zio
->io_orig_size
, &czp
, NULL
, NULL
,
2743 NULL
, zio_ddt_ditto_write_done
, dde
, zio
->io_priority
,
2744 ZIO_DDT_CHILD_FLAGS(zio
), &zio
->io_bookmark
);
2746 zio_push_transform(dio
, zio
->io_abd
, zio
->io_size
, 0, NULL
);
2747 dde
->dde_lead_zio
[DDT_PHYS_DITTO
] = dio
;
2750 if (ddp
->ddp_phys_birth
!= 0 || dde
->dde_lead_zio
[p
] != NULL
) {
2751 if (ddp
->ddp_phys_birth
!= 0)
2752 ddt_bp_fill(ddp
, bp
, txg
);
2753 if (dde
->dde_lead_zio
[p
] != NULL
)
2754 zio_add_child(zio
, dde
->dde_lead_zio
[p
]);
2756 ddt_phys_addref(ddp
);
2757 } else if (zio
->io_bp_override
) {
2758 ASSERT(bp
->blk_birth
== txg
);
2759 ASSERT(BP_EQUAL(bp
, zio
->io_bp_override
));
2760 ddt_phys_fill(ddp
, bp
);
2761 ddt_phys_addref(ddp
);
2763 cio
= zio_write(zio
, spa
, txg
, bp
, zio
->io_orig_abd
,
2764 zio
->io_orig_size
, zio
->io_orig_size
, zp
,
2765 zio_ddt_child_write_ready
, NULL
, NULL
,
2766 zio_ddt_child_write_done
, dde
, zio
->io_priority
,
2767 ZIO_DDT_CHILD_FLAGS(zio
), &zio
->io_bookmark
);
2769 zio_push_transform(cio
, zio
->io_abd
, zio
->io_size
, 0, NULL
);
2770 dde
->dde_lead_zio
[p
] = cio
;
2780 return (ZIO_PIPELINE_CONTINUE
);
2783 ddt_entry_t
*freedde
; /* for debugging */
2786 zio_ddt_free(zio_t
*zio
)
2788 spa_t
*spa
= zio
->io_spa
;
2789 blkptr_t
*bp
= zio
->io_bp
;
2790 ddt_t
*ddt
= ddt_select(spa
, bp
);
2794 ASSERT(BP_GET_DEDUP(bp
));
2795 ASSERT(zio
->io_child_type
== ZIO_CHILD_LOGICAL
);
2798 freedde
= dde
= ddt_lookup(ddt
, bp
, B_TRUE
);
2799 ddp
= ddt_phys_select(dde
, bp
);
2800 ddt_phys_decref(ddp
);
2803 return (ZIO_PIPELINE_CONTINUE
);
2807 * ==========================================================================
2808 * Allocate and free blocks
2809 * ==========================================================================
2813 zio_io_to_allocate(spa_t
*spa
, int allocator
)
2817 ASSERT(MUTEX_HELD(&spa
->spa_alloc_locks
[allocator
]));
2819 zio
= avl_first(&spa
->spa_alloc_trees
[allocator
]);
2823 ASSERT(IO_IS_ALLOCATING(zio
));
2826 * Try to place a reservation for this zio. If we're unable to
2827 * reserve then we throttle.
2829 ASSERT3U(zio
->io_allocator
, ==, allocator
);
2830 if (!metaslab_class_throttle_reserve(spa_normal_class(spa
),
2831 zio
->io_prop
.zp_copies
, zio
->io_allocator
, zio
, 0)) {
2835 avl_remove(&spa
->spa_alloc_trees
[allocator
], zio
);
2836 ASSERT3U(zio
->io_stage
, <, ZIO_STAGE_DVA_ALLOCATE
);
2842 zio_dva_throttle(zio_t
*zio
)
2844 spa_t
*spa
= zio
->io_spa
;
2847 if (zio
->io_priority
== ZIO_PRIORITY_SYNC_WRITE
||
2848 !spa_normal_class(zio
->io_spa
)->mc_alloc_throttle_enabled
||
2849 zio
->io_child_type
== ZIO_CHILD_GANG
||
2850 zio
->io_flags
& ZIO_FLAG_NODATA
) {
2851 return (ZIO_PIPELINE_CONTINUE
);
2854 ASSERT(zio
->io_child_type
> ZIO_CHILD_GANG
);
2856 ASSERT3U(zio
->io_queued_timestamp
, >, 0);
2857 ASSERT(zio
->io_stage
== ZIO_STAGE_DVA_THROTTLE
);
2859 zbookmark_phys_t
*bm
= &zio
->io_bookmark
;
2861 * We want to try to use as many allocators as possible to help improve
2862 * performance, but we also want logically adjacent IOs to be physically
2863 * adjacent to improve sequential read performance. We chunk each object
2864 * into 2^20 block regions, and then hash based on the objset, object,
2865 * level, and region to accomplish both of these goals.
2867 zio
->io_allocator
= cityhash4(bm
->zb_objset
, bm
->zb_object
,
2868 bm
->zb_level
, bm
->zb_blkid
>> 20) % spa
->spa_alloc_count
;
2869 mutex_enter(&spa
->spa_alloc_locks
[zio
->io_allocator
]);
2871 ASSERT(zio
->io_type
== ZIO_TYPE_WRITE
);
2872 avl_add(&spa
->spa_alloc_trees
[zio
->io_allocator
], zio
);
2874 nio
= zio_io_to_allocate(zio
->io_spa
, zio
->io_allocator
);
2875 mutex_exit(&spa
->spa_alloc_locks
[zio
->io_allocator
]);
2878 return (ZIO_PIPELINE_CONTINUE
);
2881 ASSERT(nio
->io_stage
== ZIO_STAGE_DVA_THROTTLE
);
2883 * We are passing control to a new zio so make sure that
2884 * it is processed by a different thread. We do this to
2885 * avoid stack overflows that can occur when parents are
2886 * throttled and children are making progress. We allow
2887 * it to go to the head of the taskq since it's already
2890 zio_taskq_dispatch(nio
, ZIO_TASKQ_ISSUE
, B_TRUE
);
2892 return (ZIO_PIPELINE_STOP
);
2896 zio_allocate_dispatch(spa_t
*spa
, int allocator
)
2900 mutex_enter(&spa
->spa_alloc_locks
[allocator
]);
2901 zio
= zio_io_to_allocate(spa
, allocator
);
2902 mutex_exit(&spa
->spa_alloc_locks
[allocator
]);
2906 ASSERT3U(zio
->io_stage
, ==, ZIO_STAGE_DVA_THROTTLE
);
2907 ASSERT0(zio
->io_error
);
2908 zio_taskq_dispatch(zio
, ZIO_TASKQ_ISSUE
, B_TRUE
);
2912 zio_dva_allocate(zio_t
*zio
)
2914 spa_t
*spa
= zio
->io_spa
;
2915 metaslab_class_t
*mc
= spa_normal_class(spa
);
2916 blkptr_t
*bp
= zio
->io_bp
;
2920 if (zio
->io_gang_leader
== NULL
) {
2921 ASSERT(zio
->io_child_type
> ZIO_CHILD_GANG
);
2922 zio
->io_gang_leader
= zio
;
2925 ASSERT(BP_IS_HOLE(bp
));
2926 ASSERT0(BP_GET_NDVAS(bp
));
2927 ASSERT3U(zio
->io_prop
.zp_copies
, >, 0);
2928 ASSERT3U(zio
->io_prop
.zp_copies
, <=, spa_max_replication(spa
));
2929 ASSERT3U(zio
->io_size
, ==, BP_GET_PSIZE(bp
));
2931 if (zio
->io_flags
& ZIO_FLAG_NODATA
) {
2932 flags
|= METASLAB_DONT_THROTTLE
;
2934 if (zio
->io_flags
& ZIO_FLAG_GANG_CHILD
) {
2935 flags
|= METASLAB_GANG_CHILD
;
2937 if (zio
->io_priority
== ZIO_PRIORITY_ASYNC_WRITE
) {
2938 flags
|= METASLAB_ASYNC_ALLOC
;
2941 error
= metaslab_alloc(spa
, mc
, zio
->io_size
, bp
,
2942 zio
->io_prop
.zp_copies
, zio
->io_txg
, NULL
, flags
,
2943 &zio
->io_alloc_list
, zio
, zio
->io_allocator
);
2946 spa_dbgmsg(spa
, "%s: metaslab allocation failure: zio %p, "
2947 "size %llu, error %d", spa_name(spa
), zio
, zio
->io_size
,
2949 if (error
== ENOSPC
&& zio
->io_size
> SPA_MINBLOCKSIZE
)
2950 return (zio_write_gang_block(zio
));
2951 zio
->io_error
= error
;
2954 return (ZIO_PIPELINE_CONTINUE
);
2958 zio_dva_free(zio_t
*zio
)
2960 metaslab_free(zio
->io_spa
, zio
->io_bp
, zio
->io_txg
, B_FALSE
);
2962 return (ZIO_PIPELINE_CONTINUE
);
2966 zio_dva_claim(zio_t
*zio
)
2970 error
= metaslab_claim(zio
->io_spa
, zio
->io_bp
, zio
->io_txg
);
2972 zio
->io_error
= error
;
2974 return (ZIO_PIPELINE_CONTINUE
);
2978 * Undo an allocation. This is used by zio_done() when an I/O fails
2979 * and we want to give back the block we just allocated.
2980 * This handles both normal blocks and gang blocks.
2983 zio_dva_unallocate(zio_t
*zio
, zio_gang_node_t
*gn
, blkptr_t
*bp
)
2985 ASSERT(bp
->blk_birth
== zio
->io_txg
|| BP_IS_HOLE(bp
));
2986 ASSERT(zio
->io_bp_override
== NULL
);
2988 if (!BP_IS_HOLE(bp
))
2989 metaslab_free(zio
->io_spa
, bp
, bp
->blk_birth
, B_TRUE
);
2992 for (int g
= 0; g
< SPA_GBH_NBLKPTRS
; g
++) {
2993 zio_dva_unallocate(zio
, gn
->gn_child
[g
],
2994 &gn
->gn_gbh
->zg_blkptr
[g
]);
3000 * Try to allocate an intent log block. Return 0 on success, errno on failure.
3003 zio_alloc_zil(spa_t
*spa
, uint64_t objset
, uint64_t txg
, blkptr_t
*new_bp
,
3004 blkptr_t
*old_bp
, uint64_t size
, boolean_t
*slog
)
3007 zio_alloc_list_t io_alloc_list
;
3009 ASSERT(txg
> spa_syncing_txg(spa
));
3011 metaslab_trace_init(&io_alloc_list
);
3013 * When allocating a zil block, we don't have information about
3014 * the final destination of the block except the objset it's part
3015 * of, so we just hash the objset ID to pick the allocator to get
3018 error
= metaslab_alloc(spa
, spa_log_class(spa
), size
, new_bp
, 1,
3019 txg
, old_bp
, METASLAB_HINTBP_AVOID
, &io_alloc_list
, NULL
,
3020 cityhash4(0, 0, 0, objset
) % spa
->spa_alloc_count
);
3024 error
= metaslab_alloc(spa
, spa_normal_class(spa
), size
,
3025 new_bp
, 1, txg
, old_bp
, METASLAB_HINTBP_AVOID
,
3026 &io_alloc_list
, NULL
, cityhash4(0, 0, 0, objset
) %
3027 spa
->spa_alloc_count
);
3031 metaslab_trace_fini(&io_alloc_list
);
3034 BP_SET_LSIZE(new_bp
, size
);
3035 BP_SET_PSIZE(new_bp
, size
);
3036 BP_SET_COMPRESS(new_bp
, ZIO_COMPRESS_OFF
);
3037 BP_SET_CHECKSUM(new_bp
,
3038 spa_version(spa
) >= SPA_VERSION_SLIM_ZIL
3039 ? ZIO_CHECKSUM_ZILOG2
: ZIO_CHECKSUM_ZILOG
);
3040 BP_SET_TYPE(new_bp
, DMU_OT_INTENT_LOG
);
3041 BP_SET_LEVEL(new_bp
, 0);
3042 BP_SET_DEDUP(new_bp
, 0);
3043 BP_SET_BYTEORDER(new_bp
, ZFS_HOST_BYTEORDER
);
3045 zfs_dbgmsg("%s: zil block allocation failure: "
3046 "size %llu, error %d", spa_name(spa
), size
, error
);
3053 * ==========================================================================
3054 * Read and write to physical devices
3055 * ==========================================================================
3060 * Issue an I/O to the underlying vdev. Typically the issue pipeline
3061 * stops after this stage and will resume upon I/O completion.
3062 * However, there are instances where the vdev layer may need to
3063 * continue the pipeline when an I/O was not issued. Since the I/O
3064 * that was sent to the vdev layer might be different than the one
3065 * currently active in the pipeline (see vdev_queue_io()), we explicitly
3066 * force the underlying vdev layers to call either zio_execute() or
3067 * zio_interrupt() to ensure that the pipeline continues with the correct I/O.
3070 zio_vdev_io_start(zio_t
*zio
)
3072 vdev_t
*vd
= zio
->io_vd
;
3074 spa_t
*spa
= zio
->io_spa
;
3076 ASSERT(zio
->io_error
== 0);
3077 ASSERT(zio
->io_child_error
[ZIO_CHILD_VDEV
] == 0);
3080 if (!(zio
->io_flags
& ZIO_FLAG_CONFIG_WRITER
))
3081 spa_config_enter(spa
, SCL_ZIO
, zio
, RW_READER
);
3084 * The mirror_ops handle multiple DVAs in a single BP.
3086 vdev_mirror_ops
.vdev_op_io_start(zio
);
3087 return (ZIO_PIPELINE_STOP
);
3090 ASSERT3P(zio
->io_logical
, !=, zio
);
3091 if (zio
->io_type
== ZIO_TYPE_WRITE
) {
3092 ASSERT(spa
->spa_trust_config
);
3094 if (zio
->io_vd
->vdev_removing
) {
3095 ASSERT(zio
->io_flags
&
3096 (ZIO_FLAG_PHYSICAL
| ZIO_FLAG_SELF_HEAL
|
3097 ZIO_FLAG_INDUCE_DAMAGE
));
3102 * We keep track of time-sensitive I/Os so that the scan thread
3103 * can quickly react to certain workloads. In particular, we care
3104 * about non-scrubbing, top-level reads and writes with the following
3106 * - synchronous writes of user data to non-slog devices
3107 * - any reads of user data
3108 * When these conditions are met, adjust the timestamp of spa_last_io
3109 * which allows the scan thread to adjust its workload accordingly.
3111 if (!(zio
->io_flags
& ZIO_FLAG_SCAN_THREAD
) && zio
->io_bp
!= NULL
&&
3112 vd
== vd
->vdev_top
&& !vd
->vdev_islog
&&
3113 zio
->io_bookmark
.zb_objset
!= DMU_META_OBJSET
&&
3114 zio
->io_txg
!= spa_syncing_txg(spa
)) {
3115 uint64_t old
= spa
->spa_last_io
;
3116 uint64_t new = ddi_get_lbolt64();
3118 (void) atomic_cas_64(&spa
->spa_last_io
, old
, new);
3121 align
= 1ULL << vd
->vdev_top
->vdev_ashift
;
3123 if (!(zio
->io_flags
& ZIO_FLAG_PHYSICAL
) &&
3124 P2PHASE(zio
->io_size
, align
) != 0) {
3125 /* Transform logical writes to be a full physical block size. */
3126 uint64_t asize
= P2ROUNDUP(zio
->io_size
, align
);
3127 abd_t
*abuf
= abd_alloc_sametype(zio
->io_abd
, asize
);
3128 ASSERT(vd
== vd
->vdev_top
);
3129 if (zio
->io_type
== ZIO_TYPE_WRITE
) {
3130 abd_copy(abuf
, zio
->io_abd
, zio
->io_size
);
3131 abd_zero_off(abuf
, zio
->io_size
, asize
- zio
->io_size
);
3133 zio_push_transform(zio
, abuf
, asize
, asize
, zio_subblock
);
3137 * If this is not a physical io, make sure that it is properly aligned
3138 * before proceeding.
3140 if (!(zio
->io_flags
& ZIO_FLAG_PHYSICAL
)) {
3141 ASSERT0(P2PHASE(zio
->io_offset
, align
));
3142 ASSERT0(P2PHASE(zio
->io_size
, align
));
3145 * For physical writes, we allow 512b aligned writes and assume
3146 * the device will perform a read-modify-write as necessary.
3148 ASSERT0(P2PHASE(zio
->io_offset
, SPA_MINBLOCKSIZE
));
3149 ASSERT0(P2PHASE(zio
->io_size
, SPA_MINBLOCKSIZE
));
3152 VERIFY(zio
->io_type
!= ZIO_TYPE_WRITE
|| spa_writeable(spa
));
3155 * If this is a repair I/O, and there's no self-healing involved --
3156 * that is, we're just resilvering what we expect to resilver --
3157 * then don't do the I/O unless zio's txg is actually in vd's DTL.
3158 * This prevents spurious resilvering with nested replication.
3159 * For example, given a mirror of mirrors, (A+B)+(C+D), if only
3160 * A is out of date, we'll read from C+D, then use the data to
3161 * resilver A+B -- but we don't actually want to resilver B, just A.
3162 * The top-level mirror has no way to know this, so instead we just
3163 * discard unnecessary repairs as we work our way down the vdev tree.
3164 * The same logic applies to any form of nested replication:
3165 * ditto + mirror, RAID-Z + replacing, etc. This covers them all.
3167 if ((zio
->io_flags
& ZIO_FLAG_IO_REPAIR
) &&
3168 !(zio
->io_flags
& ZIO_FLAG_SELF_HEAL
) &&
3169 zio
->io_txg
!= 0 && /* not a delegated i/o */
3170 !vdev_dtl_contains(vd
, DTL_PARTIAL
, zio
->io_txg
, 1)) {
3171 ASSERT(zio
->io_type
== ZIO_TYPE_WRITE
);
3172 zio_vdev_io_bypass(zio
);
3173 return (ZIO_PIPELINE_CONTINUE
);
3176 if (vd
->vdev_ops
->vdev_op_leaf
&&
3177 (zio
->io_type
== ZIO_TYPE_READ
|| zio
->io_type
== ZIO_TYPE_WRITE
)) {
3179 if (zio
->io_type
== ZIO_TYPE_READ
&& vdev_cache_read(zio
))
3180 return (ZIO_PIPELINE_CONTINUE
);
3182 if ((zio
= vdev_queue_io(zio
)) == NULL
)
3183 return (ZIO_PIPELINE_STOP
);
3185 if (!vdev_accessible(vd
, zio
)) {
3186 zio
->io_error
= SET_ERROR(ENXIO
);
3188 return (ZIO_PIPELINE_STOP
);
3192 vd
->vdev_ops
->vdev_op_io_start(zio
);
3193 return (ZIO_PIPELINE_STOP
);
3197 zio_vdev_io_done(zio_t
*zio
)
3199 vdev_t
*vd
= zio
->io_vd
;
3200 vdev_ops_t
*ops
= vd
? vd
->vdev_ops
: &vdev_mirror_ops
;
3201 boolean_t unexpected_error
= B_FALSE
;
3203 if (zio_wait_for_children(zio
, ZIO_CHILD_VDEV_BIT
, ZIO_WAIT_DONE
)) {
3204 return (ZIO_PIPELINE_STOP
);
3207 ASSERT(zio
->io_type
== ZIO_TYPE_READ
|| zio
->io_type
== ZIO_TYPE_WRITE
);
3209 if (vd
!= NULL
&& vd
->vdev_ops
->vdev_op_leaf
) {
3211 vdev_queue_io_done(zio
);
3213 if (zio
->io_type
== ZIO_TYPE_WRITE
)
3214 vdev_cache_write(zio
);
3216 if (zio_injection_enabled
&& zio
->io_error
== 0)
3217 zio
->io_error
= zio_handle_device_injection(vd
,
3220 if (zio_injection_enabled
&& zio
->io_error
== 0)
3221 zio
->io_error
= zio_handle_label_injection(zio
, EIO
);
3223 if (zio
->io_error
) {
3224 if (!vdev_accessible(vd
, zio
)) {
3225 zio
->io_error
= SET_ERROR(ENXIO
);
3227 unexpected_error
= B_TRUE
;
3232 ops
->vdev_op_io_done(zio
);
3234 if (unexpected_error
)
3235 VERIFY(vdev_probe(vd
, zio
) == NULL
);
3237 return (ZIO_PIPELINE_CONTINUE
);
3241 * For non-raidz ZIOs, we can just copy aside the bad data read from the
3242 * disk, and use that to finish the checksum ereport later.
3245 zio_vsd_default_cksum_finish(zio_cksum_report_t
*zcr
,
3246 const void *good_buf
)
3248 /* no processing needed */
3249 zfs_ereport_finish_checksum(zcr
, good_buf
, zcr
->zcr_cbdata
, B_FALSE
);
3254 zio_vsd_default_cksum_report(zio_t
*zio
, zio_cksum_report_t
*zcr
, void *ignored
)
3256 void *buf
= zio_buf_alloc(zio
->io_size
);
3258 abd_copy_to_buf(buf
, zio
->io_abd
, zio
->io_size
);
3260 zcr
->zcr_cbinfo
= zio
->io_size
;
3261 zcr
->zcr_cbdata
= buf
;
3262 zcr
->zcr_finish
= zio_vsd_default_cksum_finish
;
3263 zcr
->zcr_free
= zio_buf_free
;
3267 zio_vdev_io_assess(zio_t
*zio
)
3269 vdev_t
*vd
= zio
->io_vd
;
3271 if (zio_wait_for_children(zio
, ZIO_CHILD_VDEV_BIT
, ZIO_WAIT_DONE
)) {
3272 return (ZIO_PIPELINE_STOP
);
3275 if (vd
== NULL
&& !(zio
->io_flags
& ZIO_FLAG_CONFIG_WRITER
))
3276 spa_config_exit(zio
->io_spa
, SCL_ZIO
, zio
);
3278 if (zio
->io_vsd
!= NULL
) {
3279 zio
->io_vsd_ops
->vsd_free(zio
);
3283 if (zio_injection_enabled
&& zio
->io_error
== 0)
3284 zio
->io_error
= zio_handle_fault_injection(zio
, EIO
);
3287 * If the I/O failed, determine whether we should attempt to retry it.
3289 * On retry, we cut in line in the issue queue, since we don't want
3290 * compression/checksumming/etc. work to prevent our (cheap) IO reissue.
3292 if (zio
->io_error
&& vd
== NULL
&&
3293 !(zio
->io_flags
& (ZIO_FLAG_DONT_RETRY
| ZIO_FLAG_IO_RETRY
))) {
3294 ASSERT(!(zio
->io_flags
& ZIO_FLAG_DONT_QUEUE
)); /* not a leaf */
3295 ASSERT(!(zio
->io_flags
& ZIO_FLAG_IO_BYPASS
)); /* not a leaf */
3297 zio
->io_flags
|= ZIO_FLAG_IO_RETRY
|
3298 ZIO_FLAG_DONT_CACHE
| ZIO_FLAG_DONT_AGGREGATE
;
3299 zio
->io_stage
= ZIO_STAGE_VDEV_IO_START
>> 1;
3300 zio_taskq_dispatch(zio
, ZIO_TASKQ_ISSUE
,
3301 zio_requeue_io_start_cut_in_line
);
3302 return (ZIO_PIPELINE_STOP
);
3306 * If we got an error on a leaf device, convert it to ENXIO
3307 * if the device is not accessible at all.
3309 if (zio
->io_error
&& vd
!= NULL
&& vd
->vdev_ops
->vdev_op_leaf
&&
3310 !vdev_accessible(vd
, zio
))
3311 zio
->io_error
= SET_ERROR(ENXIO
);
3314 * If we can't write to an interior vdev (mirror or RAID-Z),
3315 * set vdev_cant_write so that we stop trying to allocate from it.
3317 if (zio
->io_error
== ENXIO
&& zio
->io_type
== ZIO_TYPE_WRITE
&&
3318 vd
!= NULL
&& !vd
->vdev_ops
->vdev_op_leaf
) {
3319 vd
->vdev_cant_write
= B_TRUE
;
3323 * If a cache flush returns ENOTSUP or ENOTTY, we know that no future
3324 * attempts will ever succeed. In this case we set a persistent bit so
3325 * that we don't bother with it in the future.
3327 if ((zio
->io_error
== ENOTSUP
|| zio
->io_error
== ENOTTY
) &&
3328 zio
->io_type
== ZIO_TYPE_IOCTL
&&
3329 zio
->io_cmd
== DKIOCFLUSHWRITECACHE
&& vd
!= NULL
)
3330 vd
->vdev_nowritecache
= B_TRUE
;
3333 zio
->io_pipeline
= ZIO_INTERLOCK_PIPELINE
;
3335 if (vd
!= NULL
&& vd
->vdev_ops
->vdev_op_leaf
&&
3336 zio
->io_physdone
!= NULL
) {
3337 ASSERT(!(zio
->io_flags
& ZIO_FLAG_DELEGATED
));
3338 ASSERT(zio
->io_child_type
== ZIO_CHILD_VDEV
);
3339 zio
->io_physdone(zio
->io_logical
);
3342 return (ZIO_PIPELINE_CONTINUE
);
3346 zio_vdev_io_reissue(zio_t
*zio
)
3348 ASSERT(zio
->io_stage
== ZIO_STAGE_VDEV_IO_START
);
3349 ASSERT(zio
->io_error
== 0);
3351 zio
->io_stage
>>= 1;
3355 zio_vdev_io_redone(zio_t
*zio
)
3357 ASSERT(zio
->io_stage
== ZIO_STAGE_VDEV_IO_DONE
);
3359 zio
->io_stage
>>= 1;
3363 zio_vdev_io_bypass(zio_t
*zio
)
3365 ASSERT(zio
->io_stage
== ZIO_STAGE_VDEV_IO_START
);
3366 ASSERT(zio
->io_error
== 0);
3368 zio
->io_flags
|= ZIO_FLAG_IO_BYPASS
;
3369 zio
->io_stage
= ZIO_STAGE_VDEV_IO_ASSESS
>> 1;
3373 * ==========================================================================
3374 * Generate and verify checksums
3375 * ==========================================================================
3378 zio_checksum_generate(zio_t
*zio
)
3380 blkptr_t
*bp
= zio
->io_bp
;
3381 enum zio_checksum checksum
;
3385 * This is zio_write_phys().
3386 * We're either generating a label checksum, or none at all.
3388 checksum
= zio
->io_prop
.zp_checksum
;
3390 if (checksum
== ZIO_CHECKSUM_OFF
)
3391 return (ZIO_PIPELINE_CONTINUE
);
3393 ASSERT(checksum
== ZIO_CHECKSUM_LABEL
);
3395 if (BP_IS_GANG(bp
) && zio
->io_child_type
== ZIO_CHILD_GANG
) {
3396 ASSERT(!IO_IS_ALLOCATING(zio
));
3397 checksum
= ZIO_CHECKSUM_GANG_HEADER
;
3399 checksum
= BP_GET_CHECKSUM(bp
);
3403 zio_checksum_compute(zio
, checksum
, zio
->io_abd
, zio
->io_size
);
3405 return (ZIO_PIPELINE_CONTINUE
);
3409 zio_checksum_verify(zio_t
*zio
)
3411 zio_bad_cksum_t info
;
3412 blkptr_t
*bp
= zio
->io_bp
;
3415 ASSERT(zio
->io_vd
!= NULL
);
3419 * This is zio_read_phys().
3420 * We're either verifying a label checksum, or nothing at all.
3422 if (zio
->io_prop
.zp_checksum
== ZIO_CHECKSUM_OFF
)
3423 return (ZIO_PIPELINE_CONTINUE
);
3425 ASSERT(zio
->io_prop
.zp_checksum
== ZIO_CHECKSUM_LABEL
);
3428 if ((error
= zio_checksum_error(zio
, &info
)) != 0) {
3429 zio
->io_error
= error
;
3430 if (error
== ECKSUM
&&
3431 !(zio
->io_flags
& ZIO_FLAG_SPECULATIVE
)) {
3432 zfs_ereport_start_checksum(zio
->io_spa
,
3433 zio
->io_vd
, zio
, zio
->io_offset
,
3434 zio
->io_size
, NULL
, &info
);
3438 return (ZIO_PIPELINE_CONTINUE
);
3442 * Called by RAID-Z to ensure we don't compute the checksum twice.
3445 zio_checksum_verified(zio_t
*zio
)
3447 zio
->io_pipeline
&= ~ZIO_STAGE_CHECKSUM_VERIFY
;
3451 * ==========================================================================
3452 * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other.
3453 * An error of 0 indicates success. ENXIO indicates whole-device failure,
3454 * which may be transient (e.g. unplugged) or permament. ECKSUM and EIO
3455 * indicate errors that are specific to one I/O, and most likely permanent.
3456 * Any other error is presumed to be worse because we weren't expecting it.
3457 * ==========================================================================
3460 zio_worst_error(int e1
, int e2
)
3462 static int zio_error_rank
[] = { 0, ENXIO
, ECKSUM
, EIO
};
3465 for (r1
= 0; r1
< sizeof (zio_error_rank
) / sizeof (int); r1
++)
3466 if (e1
== zio_error_rank
[r1
])
3469 for (r2
= 0; r2
< sizeof (zio_error_rank
) / sizeof (int); r2
++)
3470 if (e2
== zio_error_rank
[r2
])
3473 return (r1
> r2
? e1
: e2
);
3477 * ==========================================================================
3479 * ==========================================================================
3482 zio_ready(zio_t
*zio
)
3484 blkptr_t
*bp
= zio
->io_bp
;
3485 zio_t
*pio
, *pio_next
;
3486 zio_link_t
*zl
= NULL
;
3488 if (zio_wait_for_children(zio
, ZIO_CHILD_GANG_BIT
| ZIO_CHILD_DDT_BIT
,
3490 return (ZIO_PIPELINE_STOP
);
3493 if (zio
->io_ready
) {
3494 ASSERT(IO_IS_ALLOCATING(zio
));
3495 ASSERT(bp
->blk_birth
== zio
->io_txg
|| BP_IS_HOLE(bp
) ||
3496 (zio
->io_flags
& ZIO_FLAG_NOPWRITE
));
3497 ASSERT(zio
->io_children
[ZIO_CHILD_GANG
][ZIO_WAIT_READY
] == 0);
3502 if (bp
!= NULL
&& bp
!= &zio
->io_bp_copy
)
3503 zio
->io_bp_copy
= *bp
;
3505 if (zio
->io_error
!= 0) {
3506 zio
->io_pipeline
= ZIO_INTERLOCK_PIPELINE
;
3508 if (zio
->io_flags
& ZIO_FLAG_IO_ALLOCATING
) {
3509 ASSERT(IO_IS_ALLOCATING(zio
));
3510 ASSERT(zio
->io_priority
== ZIO_PRIORITY_ASYNC_WRITE
);
3512 * We were unable to allocate anything, unreserve and
3513 * issue the next I/O to allocate.
3515 metaslab_class_throttle_unreserve(
3516 spa_normal_class(zio
->io_spa
),
3517 zio
->io_prop
.zp_copies
, zio
->io_allocator
, zio
);
3518 zio_allocate_dispatch(zio
->io_spa
, zio
->io_allocator
);
3522 mutex_enter(&zio
->io_lock
);
3523 zio
->io_state
[ZIO_WAIT_READY
] = 1;
3524 pio
= zio_walk_parents(zio
, &zl
);
3525 mutex_exit(&zio
->io_lock
);
3528 * As we notify zio's parents, new parents could be added.
3529 * New parents go to the head of zio's io_parent_list, however,
3530 * so we will (correctly) not notify them. The remainder of zio's
3531 * io_parent_list, from 'pio_next' onward, cannot change because
3532 * all parents must wait for us to be done before they can be done.
3534 for (; pio
!= NULL
; pio
= pio_next
) {
3535 pio_next
= zio_walk_parents(zio
, &zl
);
3536 zio_notify_parent(pio
, zio
, ZIO_WAIT_READY
);
3539 if (zio
->io_flags
& ZIO_FLAG_NODATA
) {
3540 if (BP_IS_GANG(bp
)) {
3541 zio
->io_flags
&= ~ZIO_FLAG_NODATA
;
3543 ASSERT((uintptr_t)zio
->io_abd
< SPA_MAXBLOCKSIZE
);
3544 zio
->io_pipeline
&= ~ZIO_VDEV_IO_STAGES
;
3548 if (zio_injection_enabled
&&
3549 zio
->io_spa
->spa_syncing_txg
== zio
->io_txg
)
3550 zio_handle_ignored_writes(zio
);
3552 return (ZIO_PIPELINE_CONTINUE
);
3556 * Update the allocation throttle accounting.
3559 zio_dva_throttle_done(zio_t
*zio
)
3561 zio_t
*lio
= zio
->io_logical
;
3562 zio_t
*pio
= zio_unique_parent(zio
);
3563 vdev_t
*vd
= zio
->io_vd
;
3564 int flags
= METASLAB_ASYNC_ALLOC
;
3566 ASSERT3P(zio
->io_bp
, !=, NULL
);
3567 ASSERT3U(zio
->io_type
, ==, ZIO_TYPE_WRITE
);
3568 ASSERT3U(zio
->io_priority
, ==, ZIO_PRIORITY_ASYNC_WRITE
);
3569 ASSERT3U(zio
->io_child_type
, ==, ZIO_CHILD_VDEV
);
3571 ASSERT3P(vd
, ==, vd
->vdev_top
);
3572 ASSERT(!(zio
->io_flags
& (ZIO_FLAG_IO_REPAIR
| ZIO_FLAG_IO_RETRY
)));
3573 ASSERT(zio
->io_flags
& ZIO_FLAG_IO_ALLOCATING
);
3574 ASSERT(!(lio
->io_flags
& ZIO_FLAG_IO_REWRITE
));
3575 ASSERT(!(lio
->io_orig_flags
& ZIO_FLAG_NODATA
));
3578 * Parents of gang children can have two flavors -- ones that
3579 * allocated the gang header (will have ZIO_FLAG_IO_REWRITE set)
3580 * and ones that allocated the constituent blocks. The allocation
3581 * throttle needs to know the allocating parent zio so we must find
3584 if (pio
->io_child_type
== ZIO_CHILD_GANG
) {
3586 * If our parent is a rewrite gang child then our grandparent
3587 * would have been the one that performed the allocation.
3589 if (pio
->io_flags
& ZIO_FLAG_IO_REWRITE
)
3590 pio
= zio_unique_parent(pio
);
3591 flags
|= METASLAB_GANG_CHILD
;
3594 ASSERT(IO_IS_ALLOCATING(pio
));
3595 ASSERT3P(zio
, !=, zio
->io_logical
);
3596 ASSERT(zio
->io_logical
!= NULL
);
3597 ASSERT(!(zio
->io_flags
& ZIO_FLAG_IO_REPAIR
));
3598 ASSERT0(zio
->io_flags
& ZIO_FLAG_NOPWRITE
);
3600 mutex_enter(&pio
->io_lock
);
3601 metaslab_group_alloc_decrement(zio
->io_spa
, vd
->vdev_id
, pio
, flags
,
3602 pio
->io_allocator
, B_TRUE
);
3603 mutex_exit(&pio
->io_lock
);
3605 metaslab_class_throttle_unreserve(spa_normal_class(zio
->io_spa
),
3606 1, pio
->io_allocator
, pio
);
3609 * Call into the pipeline to see if there is more work that
3610 * needs to be done. If there is work to be done it will be
3611 * dispatched to another taskq thread.
3613 zio_allocate_dispatch(zio
->io_spa
, pio
->io_allocator
);
3617 zio_done(zio_t
*zio
)
3619 spa_t
*spa
= zio
->io_spa
;
3620 zio_t
*lio
= zio
->io_logical
;
3621 blkptr_t
*bp
= zio
->io_bp
;
3622 vdev_t
*vd
= zio
->io_vd
;
3623 uint64_t psize
= zio
->io_size
;
3624 zio_t
*pio
, *pio_next
;
3625 metaslab_class_t
*mc
= spa_normal_class(spa
);
3626 zio_link_t
*zl
= NULL
;
3629 * If our children haven't all completed,
3630 * wait for them and then repeat this pipeline stage.
3632 if (zio_wait_for_children(zio
, ZIO_CHILD_ALL_BITS
, ZIO_WAIT_DONE
)) {
3633 return (ZIO_PIPELINE_STOP
);
3637 * If the allocation throttle is enabled, then update the accounting.
3638 * We only track child I/Os that are part of an allocating async
3639 * write. We must do this since the allocation is performed
3640 * by the logical I/O but the actual write is done by child I/Os.
3642 if (zio
->io_flags
& ZIO_FLAG_IO_ALLOCATING
&&
3643 zio
->io_child_type
== ZIO_CHILD_VDEV
) {
3644 ASSERT(mc
->mc_alloc_throttle_enabled
);
3645 zio_dva_throttle_done(zio
);
3649 * If the allocation throttle is enabled, verify that
3650 * we have decremented the refcounts for every I/O that was throttled.
3652 if (zio
->io_flags
& ZIO_FLAG_IO_ALLOCATING
) {
3653 ASSERT(zio
->io_type
== ZIO_TYPE_WRITE
);
3654 ASSERT(zio
->io_priority
== ZIO_PRIORITY_ASYNC_WRITE
);
3656 metaslab_group_alloc_verify(spa
, zio
->io_bp
, zio
,
3658 VERIFY(refcount_not_held(&mc
->mc_alloc_slots
[zio
->io_allocator
],
3662 for (int c
= 0; c
< ZIO_CHILD_TYPES
; c
++)
3663 for (int w
= 0; w
< ZIO_WAIT_TYPES
; w
++)
3664 ASSERT(zio
->io_children
[c
][w
] == 0);
3666 if (bp
!= NULL
&& !BP_IS_EMBEDDED(bp
)) {
3667 ASSERT(bp
->blk_pad
[0] == 0);
3668 ASSERT(bp
->blk_pad
[1] == 0);
3669 ASSERT(bcmp(bp
, &zio
->io_bp_copy
, sizeof (blkptr_t
)) == 0 ||
3670 (bp
== zio_unique_parent(zio
)->io_bp
));
3671 if (zio
->io_type
== ZIO_TYPE_WRITE
&& !BP_IS_HOLE(bp
) &&
3672 zio
->io_bp_override
== NULL
&&
3673 !(zio
->io_flags
& ZIO_FLAG_IO_REPAIR
)) {
3674 ASSERT(!BP_SHOULD_BYTESWAP(bp
));
3675 ASSERT3U(zio
->io_prop
.zp_copies
, <=, BP_GET_NDVAS(bp
));
3676 ASSERT(BP_COUNT_GANG(bp
) == 0 ||
3677 (BP_COUNT_GANG(bp
) == BP_GET_NDVAS(bp
)));
3679 if (zio
->io_flags
& ZIO_FLAG_NOPWRITE
)
3680 VERIFY(BP_EQUAL(bp
, &zio
->io_bp_orig
));
3684 * If there were child vdev/gang/ddt errors, they apply to us now.
3686 zio_inherit_child_errors(zio
, ZIO_CHILD_VDEV
);
3687 zio_inherit_child_errors(zio
, ZIO_CHILD_GANG
);
3688 zio_inherit_child_errors(zio
, ZIO_CHILD_DDT
);
3691 * If the I/O on the transformed data was successful, generate any
3692 * checksum reports now while we still have the transformed data.
3694 if (zio
->io_error
== 0) {
3695 while (zio
->io_cksum_report
!= NULL
) {
3696 zio_cksum_report_t
*zcr
= zio
->io_cksum_report
;
3697 uint64_t align
= zcr
->zcr_align
;
3698 uint64_t asize
= P2ROUNDUP(psize
, align
);
3700 abd_t
*adata
= zio
->io_abd
;
3702 if (asize
!= psize
) {
3703 adata
= abd_alloc_linear(asize
, B_TRUE
);
3704 abd_copy(adata
, zio
->io_abd
, psize
);
3705 abd_zero_off(adata
, psize
, asize
- psize
);
3709 abuf
= abd_borrow_buf_copy(adata
, asize
);
3711 zio
->io_cksum_report
= zcr
->zcr_next
;
3712 zcr
->zcr_next
= NULL
;
3713 zcr
->zcr_finish(zcr
, abuf
);
3714 zfs_ereport_free_checksum(zcr
);
3717 abd_return_buf(adata
, abuf
, asize
);
3724 zio_pop_transforms(zio
); /* note: may set zio->io_error */
3726 vdev_stat_update(zio
, psize
);
3728 if (zio
->io_error
) {
3730 * If this I/O is attached to a particular vdev,
3731 * generate an error message describing the I/O failure
3732 * at the block level. We ignore these errors if the
3733 * device is currently unavailable.
3735 if (zio
->io_error
!= ECKSUM
&& vd
!= NULL
&& !vdev_is_dead(vd
))
3736 zfs_ereport_post(FM_EREPORT_ZFS_IO
, spa
, vd
, zio
, 0, 0);
3738 if ((zio
->io_error
== EIO
|| !(zio
->io_flags
&
3739 (ZIO_FLAG_SPECULATIVE
| ZIO_FLAG_DONT_PROPAGATE
))) &&
3742 * For logical I/O requests, tell the SPA to log the
3743 * error and generate a logical data ereport.
3745 spa_log_error(spa
, zio
);
3746 zfs_ereport_post(FM_EREPORT_ZFS_DATA
, spa
, NULL
, zio
,
3751 if (zio
->io_error
&& zio
== lio
) {
3753 * Determine whether zio should be reexecuted. This will
3754 * propagate all the way to the root via zio_notify_parent().
3756 ASSERT(vd
== NULL
&& bp
!= NULL
);
3757 ASSERT(zio
->io_child_type
== ZIO_CHILD_LOGICAL
);
3759 if (IO_IS_ALLOCATING(zio
) &&
3760 !(zio
->io_flags
& ZIO_FLAG_CANFAIL
)) {
3761 if (zio
->io_error
!= ENOSPC
)
3762 zio
->io_reexecute
|= ZIO_REEXECUTE_NOW
;
3764 zio
->io_reexecute
|= ZIO_REEXECUTE_SUSPEND
;
3767 if ((zio
->io_type
== ZIO_TYPE_READ
||
3768 zio
->io_type
== ZIO_TYPE_FREE
) &&
3769 !(zio
->io_flags
& ZIO_FLAG_SCAN_THREAD
) &&
3770 zio
->io_error
== ENXIO
&&
3771 spa_load_state(spa
) == SPA_LOAD_NONE
&&
3772 spa_get_failmode(spa
) != ZIO_FAILURE_MODE_CONTINUE
)
3773 zio
->io_reexecute
|= ZIO_REEXECUTE_SUSPEND
;
3775 if (!(zio
->io_flags
& ZIO_FLAG_CANFAIL
) && !zio
->io_reexecute
)
3776 zio
->io_reexecute
|= ZIO_REEXECUTE_SUSPEND
;
3779 * Here is a possibly good place to attempt to do
3780 * either combinatorial reconstruction or error correction
3781 * based on checksums. It also might be a good place
3782 * to send out preliminary ereports before we suspend
3788 * If there were logical child errors, they apply to us now.
3789 * We defer this until now to avoid conflating logical child
3790 * errors with errors that happened to the zio itself when
3791 * updating vdev stats and reporting FMA events above.
3793 zio_inherit_child_errors(zio
, ZIO_CHILD_LOGICAL
);
3795 if ((zio
->io_error
|| zio
->io_reexecute
) &&
3796 IO_IS_ALLOCATING(zio
) && zio
->io_gang_leader
== zio
&&
3797 !(zio
->io_flags
& (ZIO_FLAG_IO_REWRITE
| ZIO_FLAG_NOPWRITE
)))
3798 zio_dva_unallocate(zio
, zio
->io_gang_tree
, bp
);
3800 zio_gang_tree_free(&zio
->io_gang_tree
);
3803 * Godfather I/Os should never suspend.
3805 if ((zio
->io_flags
& ZIO_FLAG_GODFATHER
) &&
3806 (zio
->io_reexecute
& ZIO_REEXECUTE_SUSPEND
))
3807 zio
->io_reexecute
= 0;
3809 if (zio
->io_reexecute
) {
3811 * This is a logical I/O that wants to reexecute.
3813 * Reexecute is top-down. When an i/o fails, if it's not
3814 * the root, it simply notifies its parent and sticks around.
3815 * The parent, seeing that it still has children in zio_done(),
3816 * does the same. This percolates all the way up to the root.
3817 * The root i/o will reexecute or suspend the entire tree.
3819 * This approach ensures that zio_reexecute() honors
3820 * all the original i/o dependency relationships, e.g.
3821 * parents not executing until children are ready.
3823 ASSERT(zio
->io_child_type
== ZIO_CHILD_LOGICAL
);
3825 zio
->io_gang_leader
= NULL
;
3827 mutex_enter(&zio
->io_lock
);
3828 zio
->io_state
[ZIO_WAIT_DONE
] = 1;
3829 mutex_exit(&zio
->io_lock
);
3832 * "The Godfather" I/O monitors its children but is
3833 * not a true parent to them. It will track them through
3834 * the pipeline but severs its ties whenever they get into
3835 * trouble (e.g. suspended). This allows "The Godfather"
3836 * I/O to return status without blocking.
3839 for (pio
= zio_walk_parents(zio
, &zl
); pio
!= NULL
;
3841 zio_link_t
*remove_zl
= zl
;
3842 pio_next
= zio_walk_parents(zio
, &zl
);
3844 if ((pio
->io_flags
& ZIO_FLAG_GODFATHER
) &&
3845 (zio
->io_reexecute
& ZIO_REEXECUTE_SUSPEND
)) {
3846 zio_remove_child(pio
, zio
, remove_zl
);
3847 zio_notify_parent(pio
, zio
, ZIO_WAIT_DONE
);
3851 if ((pio
= zio_unique_parent(zio
)) != NULL
) {
3853 * We're not a root i/o, so there's nothing to do
3854 * but notify our parent. Don't propagate errors
3855 * upward since we haven't permanently failed yet.
3857 ASSERT(!(zio
->io_flags
& ZIO_FLAG_GODFATHER
));
3858 zio
->io_flags
|= ZIO_FLAG_DONT_PROPAGATE
;
3859 zio_notify_parent(pio
, zio
, ZIO_WAIT_DONE
);
3860 } else if (zio
->io_reexecute
& ZIO_REEXECUTE_SUSPEND
) {
3862 * We'd fail again if we reexecuted now, so suspend
3863 * until conditions improve (e.g. device comes online).
3865 zio_suspend(spa
, zio
);
3868 * Reexecution is potentially a huge amount of work.
3869 * Hand it off to the otherwise-unused claim taskq.
3871 ASSERT(zio
->io_tqent
.tqent_next
== NULL
);
3872 spa_taskq_dispatch_ent(spa
, ZIO_TYPE_CLAIM
,
3873 ZIO_TASKQ_ISSUE
, (task_func_t
*)zio_reexecute
, zio
,
3876 return (ZIO_PIPELINE_STOP
);
3879 ASSERT(zio
->io_child_count
== 0);
3880 ASSERT(zio
->io_reexecute
== 0);
3881 ASSERT(zio
->io_error
== 0 || (zio
->io_flags
& ZIO_FLAG_CANFAIL
));
3884 * Report any checksum errors, since the I/O is complete.
3886 while (zio
->io_cksum_report
!= NULL
) {
3887 zio_cksum_report_t
*zcr
= zio
->io_cksum_report
;
3888 zio
->io_cksum_report
= zcr
->zcr_next
;
3889 zcr
->zcr_next
= NULL
;
3890 zcr
->zcr_finish(zcr
, NULL
);
3891 zfs_ereport_free_checksum(zcr
);
3895 * It is the responsibility of the done callback to ensure that this
3896 * particular zio is no longer discoverable for adoption, and as
3897 * such, cannot acquire any new parents.
3902 mutex_enter(&zio
->io_lock
);
3903 zio
->io_state
[ZIO_WAIT_DONE
] = 1;
3904 mutex_exit(&zio
->io_lock
);
3907 for (pio
= zio_walk_parents(zio
, &zl
); pio
!= NULL
; pio
= pio_next
) {
3908 zio_link_t
*remove_zl
= zl
;
3909 pio_next
= zio_walk_parents(zio
, &zl
);
3910 zio_remove_child(pio
, zio
, remove_zl
);
3911 zio_notify_parent(pio
, zio
, ZIO_WAIT_DONE
);
3914 if (zio
->io_waiter
!= NULL
) {
3915 mutex_enter(&zio
->io_lock
);
3916 zio
->io_executor
= NULL
;
3917 cv_broadcast(&zio
->io_cv
);
3918 mutex_exit(&zio
->io_lock
);
3923 return (ZIO_PIPELINE_STOP
);
3927 * ==========================================================================
3928 * I/O pipeline definition
3929 * ==========================================================================
3931 static zio_pipe_stage_t
*zio_pipeline
[] = {
3938 zio_checksum_generate
,
3954 zio_checksum_verify
,
3962 * Compare two zbookmark_phys_t's to see which we would reach first in a
3963 * pre-order traversal of the object tree.
3965 * This is simple in every case aside from the meta-dnode object. For all other
3966 * objects, we traverse them in order (object 1 before object 2, and so on).
3967 * However, all of these objects are traversed while traversing object 0, since
3968 * the data it points to is the list of objects. Thus, we need to convert to a
3969 * canonical representation so we can compare meta-dnode bookmarks to
3970 * non-meta-dnode bookmarks.
3972 * We do this by calculating "equivalents" for each field of the zbookmark.
3973 * zbookmarks outside of the meta-dnode use their own object and level, and
3974 * calculate the level 0 equivalent (the first L0 blkid that is contained in the
3975 * blocks this bookmark refers to) by multiplying their blkid by their span
3976 * (the number of L0 blocks contained within one block at their level).
3977 * zbookmarks inside the meta-dnode calculate their object equivalent
3978 * (which is L0equiv * dnodes per data block), use 0 for their L0equiv, and use
3979 * level + 1<<31 (any value larger than a level could ever be) for their level.
3980 * This causes them to always compare before a bookmark in their object
3981 * equivalent, compare appropriately to bookmarks in other objects, and to
3982 * compare appropriately to other bookmarks in the meta-dnode.
3985 zbookmark_compare(uint16_t dbss1
, uint8_t ibs1
, uint16_t dbss2
, uint8_t ibs2
,
3986 const zbookmark_phys_t
*zb1
, const zbookmark_phys_t
*zb2
)
3989 * These variables represent the "equivalent" values for the zbookmark,
3990 * after converting zbookmarks inside the meta dnode to their
3991 * normal-object equivalents.
3993 uint64_t zb1obj
, zb2obj
;
3994 uint64_t zb1L0
, zb2L0
;
3995 uint64_t zb1level
, zb2level
;
3997 if (zb1
->zb_object
== zb2
->zb_object
&&
3998 zb1
->zb_level
== zb2
->zb_level
&&
3999 zb1
->zb_blkid
== zb2
->zb_blkid
)
4003 * BP_SPANB calculates the span in blocks.
4005 zb1L0
= (zb1
->zb_blkid
) * BP_SPANB(ibs1
, zb1
->zb_level
);
4006 zb2L0
= (zb2
->zb_blkid
) * BP_SPANB(ibs2
, zb2
->zb_level
);
4008 if (zb1
->zb_object
== DMU_META_DNODE_OBJECT
) {
4009 zb1obj
= zb1L0
* (dbss1
<< (SPA_MINBLOCKSHIFT
- DNODE_SHIFT
));
4011 zb1level
= zb1
->zb_level
+ COMPARE_META_LEVEL
;
4013 zb1obj
= zb1
->zb_object
;
4014 zb1level
= zb1
->zb_level
;
4017 if (zb2
->zb_object
== DMU_META_DNODE_OBJECT
) {
4018 zb2obj
= zb2L0
* (dbss2
<< (SPA_MINBLOCKSHIFT
- DNODE_SHIFT
));
4020 zb2level
= zb2
->zb_level
+ COMPARE_META_LEVEL
;
4022 zb2obj
= zb2
->zb_object
;
4023 zb2level
= zb2
->zb_level
;
4026 /* Now that we have a canonical representation, do the comparison. */
4027 if (zb1obj
!= zb2obj
)
4028 return (zb1obj
< zb2obj
? -1 : 1);
4029 else if (zb1L0
!= zb2L0
)
4030 return (zb1L0
< zb2L0
? -1 : 1);
4031 else if (zb1level
!= zb2level
)
4032 return (zb1level
> zb2level
? -1 : 1);
4034 * This can (theoretically) happen if the bookmarks have the same object
4035 * and level, but different blkids, if the block sizes are not the same.
4036 * There is presently no way to change the indirect block sizes
4042 * This function checks the following: given that last_block is the place that
4043 * our traversal stopped last time, does that guarantee that we've visited
4044 * every node under subtree_root? Therefore, we can't just use the raw output
4045 * of zbookmark_compare. We have to pass in a modified version of
4046 * subtree_root; by incrementing the block id, and then checking whether
4047 * last_block is before or equal to that, we can tell whether or not having
4048 * visited last_block implies that all of subtree_root's children have been
4052 zbookmark_subtree_completed(const dnode_phys_t
*dnp
,
4053 const zbookmark_phys_t
*subtree_root
, const zbookmark_phys_t
*last_block
)
4055 zbookmark_phys_t mod_zb
= *subtree_root
;
4057 ASSERT(last_block
->zb_level
== 0);
4059 /* The objset_phys_t isn't before anything. */
4064 * We pass in 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT) for the
4065 * data block size in sectors, because that variable is only used if
4066 * the bookmark refers to a block in the meta-dnode. Since we don't
4067 * know without examining it what object it refers to, and there's no
4068 * harm in passing in this value in other cases, we always pass it in.
4070 * We pass in 0 for the indirect block size shift because zb2 must be
4071 * level 0. The indirect block size is only used to calculate the span
4072 * of the bookmark, but since the bookmark must be level 0, the span is
4073 * always 1, so the math works out.
4075 * If you make changes to how the zbookmark_compare code works, be sure
4076 * to make sure that this code still works afterwards.
4078 return (zbookmark_compare(dnp
->dn_datablkszsec
, dnp
->dn_indblkshift
,
4079 1ULL << (DNODE_BLOCK_SHIFT
- SPA_MINBLOCKSHIFT
), 0, &mod_zb
,