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 2008 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
26 #include <sys/zfs_context.h>
27 #include <sys/fm/fs/zfs.h>
30 #include <sys/spa_impl.h>
31 #include <sys/vdev_impl.h>
32 #include <sys/zio_impl.h>
33 #include <sys/zio_compress.h>
34 #include <sys/zio_checksum.h>
37 * ==========================================================================
39 * ==========================================================================
41 uint8_t zio_priority_table
[ZIO_PRIORITY_TABLE_SIZE
] = {
42 0, /* ZIO_PRIORITY_NOW */
43 0, /* ZIO_PRIORITY_SYNC_READ */
44 0, /* ZIO_PRIORITY_SYNC_WRITE */
45 6, /* ZIO_PRIORITY_ASYNC_READ */
46 4, /* ZIO_PRIORITY_ASYNC_WRITE */
47 4, /* ZIO_PRIORITY_FREE */
48 0, /* ZIO_PRIORITY_CACHE_FILL */
49 0, /* ZIO_PRIORITY_LOG_WRITE */
50 10, /* ZIO_PRIORITY_RESILVER */
51 20, /* ZIO_PRIORITY_SCRUB */
55 * ==========================================================================
56 * I/O type descriptions
57 * ==========================================================================
59 char *zio_type_name
[ZIO_TYPES
] = {
60 "null", "read", "write", "free", "claim", "ioctl" };
62 #define SYNC_PASS_DEFERRED_FREE 1 /* defer frees after this pass */
63 #define SYNC_PASS_DONT_COMPRESS 4 /* don't compress after this pass */
64 #define SYNC_PASS_REWRITE 1 /* rewrite new bps after this pass */
67 * ==========================================================================
69 * ==========================================================================
71 kmem_cache_t
*zio_cache
;
72 kmem_cache_t
*zio_buf_cache
[SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
];
73 kmem_cache_t
*zio_data_buf_cache
[SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
];
76 extern vmem_t
*zio_alloc_arena
;
80 * An allocating zio is one that either currently has the DVA allocate
81 * stage set or will have it later in its lifetime.
83 #define IO_IS_ALLOCATING(zio) \
84 ((zio)->io_orig_pipeline & (1U << ZIO_STAGE_DVA_ALLOCATE))
90 vmem_t
*data_alloc_arena
= NULL
;
93 data_alloc_arena
= zio_alloc_arena
;
95 zio_cache
= kmem_cache_create("zio_cache", sizeof (zio_t
), 0,
96 NULL
, NULL
, NULL
, NULL
, NULL
, 0);
99 * For small buffers, we want a cache for each multiple of
100 * SPA_MINBLOCKSIZE. For medium-size buffers, we want a cache
101 * for each quarter-power of 2. For large buffers, we want
102 * a cache for each multiple of PAGESIZE.
104 for (c
= 0; c
< SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
; c
++) {
105 size_t size
= (c
+ 1) << SPA_MINBLOCKSHIFT
;
109 while (p2
& (p2
- 1))
112 if (size
<= 4 * SPA_MINBLOCKSIZE
) {
113 align
= SPA_MINBLOCKSIZE
;
114 } else if (P2PHASE(size
, PAGESIZE
) == 0) {
116 } else if (P2PHASE(size
, p2
>> 2) == 0) {
122 (void) sprintf(name
, "zio_buf_%lu", (ulong_t
)size
);
123 zio_buf_cache
[c
] = kmem_cache_create(name
, size
,
124 align
, NULL
, NULL
, NULL
, NULL
, NULL
, KMC_NODEBUG
);
126 (void) sprintf(name
, "zio_data_buf_%lu", (ulong_t
)size
);
127 zio_data_buf_cache
[c
] = kmem_cache_create(name
, size
,
128 align
, NULL
, NULL
, NULL
, NULL
, data_alloc_arena
,
134 ASSERT(zio_buf_cache
[c
] != NULL
);
135 if (zio_buf_cache
[c
- 1] == NULL
)
136 zio_buf_cache
[c
- 1] = zio_buf_cache
[c
];
138 ASSERT(zio_data_buf_cache
[c
] != NULL
);
139 if (zio_data_buf_cache
[c
- 1] == NULL
)
140 zio_data_buf_cache
[c
- 1] = zio_data_buf_cache
[c
];
150 kmem_cache_t
*last_cache
= NULL
;
151 kmem_cache_t
*last_data_cache
= NULL
;
153 for (c
= 0; c
< SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
; c
++) {
154 if (zio_buf_cache
[c
] != last_cache
) {
155 last_cache
= zio_buf_cache
[c
];
156 kmem_cache_destroy(zio_buf_cache
[c
]);
158 zio_buf_cache
[c
] = NULL
;
160 if (zio_data_buf_cache
[c
] != last_data_cache
) {
161 last_data_cache
= zio_data_buf_cache
[c
];
162 kmem_cache_destroy(zio_data_buf_cache
[c
]);
164 zio_data_buf_cache
[c
] = NULL
;
167 kmem_cache_destroy(zio_cache
);
173 * ==========================================================================
174 * Allocate and free I/O buffers
175 * ==========================================================================
179 * Use zio_buf_alloc to allocate ZFS metadata. This data will appear in a
180 * crashdump if the kernel panics, so use it judiciously. Obviously, it's
181 * useful to inspect ZFS metadata, but if possible, we should avoid keeping
182 * excess / transient data in-core during a crashdump.
185 zio_buf_alloc(size_t size
)
187 size_t c
= (size
- 1) >> SPA_MINBLOCKSHIFT
;
189 ASSERT(c
< SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
);
191 return (kmem_cache_alloc(zio_buf_cache
[c
], KM_PUSHPAGE
));
195 * Use zio_data_buf_alloc to allocate data. The data will not appear in a
196 * crashdump if the kernel panics. This exists so that we will limit the amount
197 * of ZFS data that shows up in a kernel crashdump. (Thus reducing the amount
198 * of kernel heap dumped to disk when the kernel panics)
201 zio_data_buf_alloc(size_t size
)
203 size_t c
= (size
- 1) >> SPA_MINBLOCKSHIFT
;
205 ASSERT(c
< SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
);
207 return (kmem_cache_alloc(zio_data_buf_cache
[c
], KM_PUSHPAGE
));
211 zio_buf_free(void *buf
, size_t size
)
213 size_t c
= (size
- 1) >> SPA_MINBLOCKSHIFT
;
215 ASSERT(c
< SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
);
217 kmem_cache_free(zio_buf_cache
[c
], buf
);
221 zio_data_buf_free(void *buf
, size_t size
)
223 size_t c
= (size
- 1) >> SPA_MINBLOCKSHIFT
;
225 ASSERT(c
< SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
);
227 kmem_cache_free(zio_data_buf_cache
[c
], buf
);
231 * ==========================================================================
232 * Push and pop I/O transform buffers
233 * ==========================================================================
236 zio_push_transform(zio_t
*zio
, void *data
, uint64_t size
, uint64_t bufsize
,
237 zio_transform_func_t
*transform
)
239 zio_transform_t
*zt
= kmem_alloc(sizeof (zio_transform_t
), KM_SLEEP
);
241 zt
->zt_orig_data
= zio
->io_data
;
242 zt
->zt_orig_size
= zio
->io_size
;
243 zt
->zt_bufsize
= bufsize
;
244 zt
->zt_transform
= transform
;
246 zt
->zt_next
= zio
->io_transform_stack
;
247 zio
->io_transform_stack
= zt
;
254 zio_pop_transforms(zio_t
*zio
)
258 while ((zt
= zio
->io_transform_stack
) != NULL
) {
259 if (zt
->zt_transform
!= NULL
)
260 zt
->zt_transform(zio
,
261 zt
->zt_orig_data
, zt
->zt_orig_size
);
263 zio_buf_free(zio
->io_data
, zt
->zt_bufsize
);
265 zio
->io_data
= zt
->zt_orig_data
;
266 zio
->io_size
= zt
->zt_orig_size
;
267 zio
->io_transform_stack
= zt
->zt_next
;
269 kmem_free(zt
, sizeof (zio_transform_t
));
274 * ==========================================================================
275 * I/O transform callbacks for subblocks and decompression
276 * ==========================================================================
279 zio_subblock(zio_t
*zio
, void *data
, uint64_t size
)
281 ASSERT(zio
->io_size
> size
);
283 if (zio
->io_type
== ZIO_TYPE_READ
)
284 bcopy(zio
->io_data
, data
, size
);
288 zio_decompress(zio_t
*zio
, void *data
, uint64_t size
)
290 if (zio
->io_error
== 0 &&
291 zio_decompress_data(BP_GET_COMPRESS(zio
->io_bp
),
292 zio
->io_data
, zio
->io_size
, data
, size
) != 0)
297 * ==========================================================================
298 * I/O parent/child relationships and pipeline interlocks
299 * ==========================================================================
303 zio_add_child(zio_t
*pio
, zio_t
*zio
)
305 mutex_enter(&pio
->io_lock
);
306 if (zio
->io_stage
< ZIO_STAGE_READY
)
307 pio
->io_children
[zio
->io_child_type
][ZIO_WAIT_READY
]++;
308 if (zio
->io_stage
< ZIO_STAGE_DONE
)
309 pio
->io_children
[zio
->io_child_type
][ZIO_WAIT_DONE
]++;
310 zio
->io_sibling_prev
= NULL
;
311 zio
->io_sibling_next
= pio
->io_child
;
312 if (pio
->io_child
!= NULL
)
313 pio
->io_child
->io_sibling_prev
= zio
;
315 zio
->io_parent
= pio
;
316 mutex_exit(&pio
->io_lock
);
320 zio_remove_child(zio_t
*pio
, zio_t
*zio
)
324 ASSERT(zio
->io_parent
== pio
);
326 mutex_enter(&pio
->io_lock
);
327 next
= zio
->io_sibling_next
;
328 prev
= zio
->io_sibling_prev
;
330 next
->io_sibling_prev
= prev
;
332 prev
->io_sibling_next
= next
;
333 if (pio
->io_child
== zio
)
334 pio
->io_child
= next
;
335 mutex_exit(&pio
->io_lock
);
339 zio_wait_for_children(zio_t
*zio
, enum zio_child child
, enum zio_wait_type wait
)
341 uint64_t *countp
= &zio
->io_children
[child
][wait
];
342 boolean_t waiting
= B_FALSE
;
344 mutex_enter(&zio
->io_lock
);
345 ASSERT(zio
->io_stall
== NULL
);
348 zio
->io_stall
= countp
;
351 mutex_exit(&zio
->io_lock
);
357 zio_notify_parent(zio_t
*pio
, zio_t
*zio
, enum zio_wait_type wait
)
359 uint64_t *countp
= &pio
->io_children
[zio
->io_child_type
][wait
];
360 int *errorp
= &pio
->io_child_error
[zio
->io_child_type
];
362 mutex_enter(&pio
->io_lock
);
363 if (zio
->io_error
&& !(zio
->io_flags
& ZIO_FLAG_DONT_PROPAGATE
))
364 *errorp
= zio_worst_error(*errorp
, zio
->io_error
);
365 pio
->io_reexecute
|= zio
->io_reexecute
;
366 ASSERT3U(*countp
, >, 0);
367 if (--*countp
== 0 && pio
->io_stall
== countp
) {
368 pio
->io_stall
= NULL
;
369 mutex_exit(&pio
->io_lock
);
372 mutex_exit(&pio
->io_lock
);
377 zio_inherit_child_errors(zio_t
*zio
, enum zio_child c
)
379 if (zio
->io_child_error
[c
] != 0 && zio
->io_error
== 0)
380 zio
->io_error
= zio
->io_child_error
[c
];
384 * ==========================================================================
385 * Create the various types of I/O (read, write, free, etc)
386 * ==========================================================================
389 zio_create(zio_t
*pio
, spa_t
*spa
, uint64_t txg
, blkptr_t
*bp
,
390 void *data
, uint64_t size
, zio_done_func_t
*done
, void *private,
391 zio_type_t type
, int priority
, int flags
, vdev_t
*vd
, uint64_t offset
,
392 const zbookmark_t
*zb
, uint8_t stage
, uint32_t pipeline
)
396 ASSERT3U(size
, <=, SPA_MAXBLOCKSIZE
);
397 ASSERT(P2PHASE(size
, SPA_MINBLOCKSIZE
) == 0);
398 ASSERT(P2PHASE(offset
, SPA_MINBLOCKSIZE
) == 0);
400 ASSERT(!vd
|| spa_config_held(spa
, SCL_STATE_ALL
, RW_READER
));
401 ASSERT(!bp
|| !(flags
& ZIO_FLAG_CONFIG_WRITER
));
402 ASSERT(vd
|| stage
== ZIO_STAGE_OPEN
);
404 zio
= kmem_cache_alloc(zio_cache
, KM_SLEEP
);
405 bzero(zio
, sizeof (zio_t
));
407 mutex_init(&zio
->io_lock
, NULL
, MUTEX_DEFAULT
, NULL
);
408 cv_init(&zio
->io_cv
, NULL
, CV_DEFAULT
, NULL
);
411 zio
->io_child_type
= ZIO_CHILD_VDEV
;
412 else if (flags
& ZIO_FLAG_GANG_CHILD
)
413 zio
->io_child_type
= ZIO_CHILD_GANG
;
415 zio
->io_child_type
= ZIO_CHILD_LOGICAL
;
419 zio
->io_bp_copy
= *bp
;
420 zio
->io_bp_orig
= *bp
;
421 if (type
!= ZIO_TYPE_WRITE
)
422 zio
->io_bp
= &zio
->io_bp_copy
; /* so caller can free */
423 if (zio
->io_child_type
== ZIO_CHILD_LOGICAL
) {
425 pipeline
|= ZIO_GANG_STAGES
;
426 zio
->io_logical
= zio
;
435 zio
->io_private
= private;
437 zio
->io_priority
= priority
;
439 zio
->io_offset
= offset
;
440 zio
->io_orig_flags
= zio
->io_flags
= flags
;
441 zio
->io_orig_stage
= zio
->io_stage
= stage
;
442 zio
->io_orig_pipeline
= zio
->io_pipeline
= pipeline
;
445 zio
->io_bookmark
= *zb
;
449 * Logical I/Os can have logical, gang, or vdev children.
450 * Gang I/Os can have gang or vdev children.
451 * Vdev I/Os can only have vdev children.
452 * The following ASSERT captures all of these constraints.
454 ASSERT(zio
->io_child_type
<= pio
->io_child_type
);
455 if (zio
->io_logical
== NULL
)
456 zio
->io_logical
= pio
->io_logical
;
457 zio_add_child(pio
, zio
);
464 zio_destroy(zio_t
*zio
)
466 spa_t
*spa
= zio
->io_spa
;
467 uint8_t async_root
= zio
->io_async_root
;
469 mutex_destroy(&zio
->io_lock
);
470 cv_destroy(&zio
->io_cv
);
471 kmem_cache_free(zio_cache
, zio
);
474 mutex_enter(&spa
->spa_async_root_lock
);
475 if (--spa
->spa_async_root_count
== 0)
476 cv_broadcast(&spa
->spa_async_root_cv
);
477 mutex_exit(&spa
->spa_async_root_lock
);
482 zio_null(zio_t
*pio
, spa_t
*spa
, zio_done_func_t
*done
, void *private,
487 zio
= zio_create(pio
, spa
, 0, NULL
, NULL
, 0, done
, private,
488 ZIO_TYPE_NULL
, ZIO_PRIORITY_NOW
, flags
, NULL
, 0, NULL
,
489 ZIO_STAGE_OPEN
, ZIO_INTERLOCK_PIPELINE
);
495 zio_root(spa_t
*spa
, zio_done_func_t
*done
, void *private, int flags
)
497 return (zio_null(NULL
, spa
, done
, private, flags
));
501 zio_read(zio_t
*pio
, spa_t
*spa
, const blkptr_t
*bp
,
502 void *data
, uint64_t size
, zio_done_func_t
*done
, void *private,
503 int priority
, int flags
, const zbookmark_t
*zb
)
507 zio
= zio_create(pio
, spa
, bp
->blk_birth
, (blkptr_t
*)bp
,
508 data
, size
, done
, private,
509 ZIO_TYPE_READ
, priority
, flags
, NULL
, 0, zb
,
510 ZIO_STAGE_OPEN
, ZIO_READ_PIPELINE
);
516 zio_skip_write(zio_t
*zio
)
518 ASSERT(zio
->io_type
== ZIO_TYPE_WRITE
);
519 ASSERT(zio
->io_stage
== ZIO_STAGE_READY
);
520 ASSERT(!BP_IS_GANG(zio
->io_bp
));
522 zio
->io_pipeline
&= ~ZIO_VDEV_IO_STAGES
;
526 zio_write(zio_t
*pio
, spa_t
*spa
, uint64_t txg
, blkptr_t
*bp
,
527 void *data
, uint64_t size
, zio_prop_t
*zp
,
528 zio_done_func_t
*ready
, zio_done_func_t
*done
, void *private,
529 int priority
, int flags
, const zbookmark_t
*zb
)
533 ASSERT(zp
->zp_checksum
>= ZIO_CHECKSUM_OFF
&&
534 zp
->zp_checksum
< ZIO_CHECKSUM_FUNCTIONS
&&
535 zp
->zp_compress
>= ZIO_COMPRESS_OFF
&&
536 zp
->zp_compress
< ZIO_COMPRESS_FUNCTIONS
&&
537 zp
->zp_type
< DMU_OT_NUMTYPES
&&
540 zp
->zp_ndvas
<= spa_max_replication(spa
));
541 ASSERT(ready
!= NULL
);
543 zio
= zio_create(pio
, spa
, txg
, bp
, data
, size
, done
, private,
544 ZIO_TYPE_WRITE
, priority
, flags
, NULL
, 0, zb
,
545 ZIO_STAGE_OPEN
, ZIO_WRITE_PIPELINE
);
547 zio
->io_ready
= ready
;
554 zio_rewrite(zio_t
*pio
, spa_t
*spa
, uint64_t txg
, blkptr_t
*bp
, void *data
,
555 uint64_t size
, zio_done_func_t
*done
, void *private, int priority
,
556 int flags
, zbookmark_t
*zb
)
560 zio
= zio_create(pio
, spa
, txg
, bp
, data
, size
, done
, private,
561 ZIO_TYPE_WRITE
, priority
, flags
, NULL
, 0, zb
,
562 ZIO_STAGE_OPEN
, ZIO_REWRITE_PIPELINE
);
568 zio_free(zio_t
*pio
, spa_t
*spa
, uint64_t txg
, blkptr_t
*bp
,
569 zio_done_func_t
*done
, void *private, int flags
)
573 ASSERT(!BP_IS_HOLE(bp
));
575 if (bp
->blk_fill
== BLK_FILL_ALREADY_FREED
)
576 return (zio_null(pio
, spa
, NULL
, NULL
, flags
));
578 if (txg
== spa
->spa_syncing_txg
&&
579 spa_sync_pass(spa
) > SYNC_PASS_DEFERRED_FREE
) {
580 bplist_enqueue_deferred(&spa
->spa_sync_bplist
, bp
);
581 return (zio_null(pio
, spa
, NULL
, NULL
, flags
));
584 zio
= zio_create(pio
, spa
, txg
, bp
, NULL
, BP_GET_PSIZE(bp
),
585 done
, private, ZIO_TYPE_FREE
, ZIO_PRIORITY_FREE
, flags
,
586 NULL
, 0, NULL
, ZIO_STAGE_OPEN
, ZIO_FREE_PIPELINE
);
592 zio_claim(zio_t
*pio
, spa_t
*spa
, uint64_t txg
, blkptr_t
*bp
,
593 zio_done_func_t
*done
, void *private, int flags
)
598 * A claim is an allocation of a specific block. Claims are needed
599 * to support immediate writes in the intent log. The issue is that
600 * immediate writes contain committed data, but in a txg that was
601 * *not* committed. Upon opening the pool after an unclean shutdown,
602 * the intent log claims all blocks that contain immediate write data
603 * so that the SPA knows they're in use.
605 * All claims *must* be resolved in the first txg -- before the SPA
606 * starts allocating blocks -- so that nothing is allocated twice.
608 ASSERT3U(spa
->spa_uberblock
.ub_rootbp
.blk_birth
, <, spa_first_txg(spa
));
609 ASSERT3U(spa_first_txg(spa
), <=, txg
);
611 zio
= zio_create(pio
, spa
, txg
, bp
, NULL
, BP_GET_PSIZE(bp
),
612 done
, private, ZIO_TYPE_CLAIM
, ZIO_PRIORITY_NOW
, flags
,
613 NULL
, 0, NULL
, ZIO_STAGE_OPEN
, ZIO_CLAIM_PIPELINE
);
619 zio_ioctl(zio_t
*pio
, spa_t
*spa
, vdev_t
*vd
, int cmd
,
620 zio_done_func_t
*done
, void *private, int priority
, int flags
)
625 if (vd
->vdev_children
== 0) {
626 zio
= zio_create(pio
, spa
, 0, NULL
, NULL
, 0, done
, private,
627 ZIO_TYPE_IOCTL
, priority
, flags
, vd
, 0, NULL
,
628 ZIO_STAGE_OPEN
, ZIO_IOCTL_PIPELINE
);
632 zio
= zio_null(pio
, spa
, NULL
, NULL
, flags
);
634 for (c
= 0; c
< vd
->vdev_children
; c
++)
635 zio_nowait(zio_ioctl(zio
, spa
, vd
->vdev_child
[c
], cmd
,
636 done
, private, priority
, flags
));
643 zio_read_phys(zio_t
*pio
, vdev_t
*vd
, uint64_t offset
, uint64_t size
,
644 void *data
, int checksum
, zio_done_func_t
*done
, void *private,
645 int priority
, int flags
, boolean_t labels
)
649 ASSERT(vd
->vdev_children
== 0);
650 ASSERT(!labels
|| offset
+ size
<= VDEV_LABEL_START_SIZE
||
651 offset
>= vd
->vdev_psize
- VDEV_LABEL_END_SIZE
);
652 ASSERT3U(offset
+ size
, <=, vd
->vdev_psize
);
654 zio
= zio_create(pio
, vd
->vdev_spa
, 0, NULL
, data
, size
, done
, private,
655 ZIO_TYPE_READ
, priority
, flags
, vd
, offset
, NULL
,
656 ZIO_STAGE_OPEN
, ZIO_READ_PHYS_PIPELINE
);
658 zio
->io_prop
.zp_checksum
= checksum
;
664 zio_write_phys(zio_t
*pio
, vdev_t
*vd
, uint64_t offset
, uint64_t size
,
665 void *data
, int checksum
, zio_done_func_t
*done
, void *private,
666 int priority
, int flags
, boolean_t labels
)
670 ASSERT(vd
->vdev_children
== 0);
671 ASSERT(!labels
|| offset
+ size
<= VDEV_LABEL_START_SIZE
||
672 offset
>= vd
->vdev_psize
- VDEV_LABEL_END_SIZE
);
673 ASSERT3U(offset
+ size
, <=, vd
->vdev_psize
);
675 zio
= zio_create(pio
, vd
->vdev_spa
, 0, NULL
, data
, size
, done
, private,
676 ZIO_TYPE_WRITE
, priority
, flags
, vd
, offset
, NULL
,
677 ZIO_STAGE_OPEN
, ZIO_WRITE_PHYS_PIPELINE
);
679 zio
->io_prop
.zp_checksum
= checksum
;
681 if (zio_checksum_table
[checksum
].ci_zbt
) {
683 * zbt checksums are necessarily destructive -- they modify
684 * the end of the write buffer to hold the verifier/checksum.
685 * Therefore, we must make a local copy in case the data is
686 * being written to multiple places in parallel.
688 void *wbuf
= zio_buf_alloc(size
);
689 bcopy(data
, wbuf
, size
);
690 zio_push_transform(zio
, wbuf
, size
, size
, NULL
);
697 * Create a child I/O to do some work for us.
700 zio_vdev_child_io(zio_t
*pio
, blkptr_t
*bp
, vdev_t
*vd
, uint64_t offset
,
701 void *data
, uint64_t size
, int type
, int priority
, int flags
,
702 zio_done_func_t
*done
, void *private)
704 uint32_t pipeline
= ZIO_VDEV_CHILD_PIPELINE
;
707 ASSERT(vd
->vdev_parent
==
708 (pio
->io_vd
? pio
->io_vd
: pio
->io_spa
->spa_root_vdev
));
710 if (type
== ZIO_TYPE_READ
&& bp
!= NULL
) {
712 * If we have the bp, then the child should perform the
713 * checksum and the parent need not. This pushes error
714 * detection as close to the leaves as possible and
715 * eliminates redundant checksums in the interior nodes.
717 pipeline
|= 1U << ZIO_STAGE_CHECKSUM_VERIFY
;
718 pio
->io_pipeline
&= ~(1U << ZIO_STAGE_CHECKSUM_VERIFY
);
721 if (vd
->vdev_children
== 0)
722 offset
+= VDEV_LABEL_START_SIZE
;
724 zio
= zio_create(pio
, pio
->io_spa
, pio
->io_txg
, bp
, data
, size
,
725 done
, private, type
, priority
,
726 (pio
->io_flags
& ZIO_FLAG_VDEV_INHERIT
) |
727 ZIO_FLAG_CANFAIL
| ZIO_FLAG_DONT_PROPAGATE
| flags
,
728 vd
, offset
, &pio
->io_bookmark
,
729 ZIO_STAGE_VDEV_IO_START
- 1, pipeline
);
735 zio_vdev_delegated_io(vdev_t
*vd
, uint64_t offset
, void *data
, uint64_t size
,
736 int type
, int priority
, int flags
, zio_done_func_t
*done
, void *private)
740 ASSERT(vd
->vdev_ops
->vdev_op_leaf
);
742 zio
= zio_create(NULL
, vd
->vdev_spa
, 0, NULL
,
743 data
, size
, done
, private, type
, priority
,
744 flags
| ZIO_FLAG_CANFAIL
| ZIO_FLAG_DONT_RETRY
,
746 ZIO_STAGE_VDEV_IO_START
- 1, ZIO_VDEV_CHILD_PIPELINE
);
752 zio_flush(zio_t
*zio
, vdev_t
*vd
)
754 zio_nowait(zio_ioctl(zio
, zio
->io_spa
, vd
, DKIOCFLUSHWRITECACHE
,
755 NULL
, NULL
, ZIO_PRIORITY_NOW
,
756 ZIO_FLAG_CANFAIL
| ZIO_FLAG_DONT_PROPAGATE
| ZIO_FLAG_DONT_RETRY
));
760 * ==========================================================================
761 * Prepare to read and write logical blocks
762 * ==========================================================================
766 zio_read_bp_init(zio_t
*zio
)
768 blkptr_t
*bp
= zio
->io_bp
;
770 if (BP_GET_COMPRESS(bp
) != ZIO_COMPRESS_OFF
&& zio
->io_logical
== zio
) {
771 uint64_t csize
= BP_GET_PSIZE(bp
);
772 void *cbuf
= zio_buf_alloc(csize
);
774 zio_push_transform(zio
, cbuf
, csize
, csize
, zio_decompress
);
777 if (!dmu_ot
[BP_GET_TYPE(bp
)].ot_metadata
&& BP_GET_LEVEL(bp
) == 0)
778 zio
->io_flags
|= ZIO_FLAG_DONT_CACHE
;
780 return (ZIO_PIPELINE_CONTINUE
);
784 zio_write_bp_init(zio_t
*zio
)
786 zio_prop_t
*zp
= &zio
->io_prop
;
787 int compress
= zp
->zp_compress
;
788 blkptr_t
*bp
= zio
->io_bp
;
790 uint64_t lsize
= zio
->io_size
;
791 uint64_t csize
= lsize
;
792 uint64_t cbufsize
= 0;
796 * If our children haven't all reached the ready stage,
797 * wait for them and then repeat this pipeline stage.
799 if (zio_wait_for_children(zio
, ZIO_CHILD_GANG
, ZIO_WAIT_READY
) ||
800 zio_wait_for_children(zio
, ZIO_CHILD_LOGICAL
, ZIO_WAIT_READY
))
801 return (ZIO_PIPELINE_STOP
);
803 if (!IO_IS_ALLOCATING(zio
))
804 return (ZIO_PIPELINE_CONTINUE
);
806 ASSERT(compress
!= ZIO_COMPRESS_INHERIT
);
808 if (bp
->blk_birth
== zio
->io_txg
) {
810 * We're rewriting an existing block, which means we're
811 * working on behalf of spa_sync(). For spa_sync() to
812 * converge, it must eventually be the case that we don't
813 * have to allocate new blocks. But compression changes
814 * the blocksize, which forces a reallocate, and makes
815 * convergence take longer. Therefore, after the first
816 * few passes, stop compressing to ensure convergence.
818 pass
= spa_sync_pass(zio
->io_spa
);
821 if (pass
> SYNC_PASS_DONT_COMPRESS
)
822 compress
= ZIO_COMPRESS_OFF
;
825 * Only MOS (objset 0) data should need to be rewritten.
827 ASSERT(zio
->io_logical
->io_bookmark
.zb_objset
== 0);
829 /* Make sure someone doesn't change their mind on overwrites */
830 ASSERT(MIN(zp
->zp_ndvas
+ BP_IS_GANG(bp
),
831 spa_max_replication(zio
->io_spa
)) == BP_GET_NDVAS(bp
));
834 if (compress
!= ZIO_COMPRESS_OFF
) {
835 if (!zio_compress_data(compress
, zio
->io_data
, zio
->io_size
,
836 &cbuf
, &csize
, &cbufsize
)) {
837 compress
= ZIO_COMPRESS_OFF
;
838 } else if (csize
!= 0) {
839 zio_push_transform(zio
, cbuf
, csize
, cbufsize
, NULL
);
844 * The final pass of spa_sync() must be all rewrites, but the first
845 * few passes offer a trade-off: allocating blocks defers convergence,
846 * but newly allocated blocks are sequential, so they can be written
847 * to disk faster. Therefore, we allow the first few passes of
848 * spa_sync() to allocate new blocks, but force rewrites after that.
849 * There should only be a handful of blocks after pass 1 in any case.
851 if (bp
->blk_birth
== zio
->io_txg
&& BP_GET_PSIZE(bp
) == csize
&&
852 pass
> SYNC_PASS_REWRITE
) {
854 uint32_t gang_stages
= zio
->io_pipeline
& ZIO_GANG_STAGES
;
855 zio
->io_pipeline
= ZIO_REWRITE_PIPELINE
| gang_stages
;
856 zio
->io_flags
|= ZIO_FLAG_IO_REWRITE
;
859 zio
->io_pipeline
= ZIO_WRITE_PIPELINE
;
863 zio
->io_pipeline
= ZIO_INTERLOCK_PIPELINE
;
865 ASSERT(zp
->zp_checksum
!= ZIO_CHECKSUM_GANG_HEADER
);
866 BP_SET_LSIZE(bp
, lsize
);
867 BP_SET_PSIZE(bp
, csize
);
868 BP_SET_COMPRESS(bp
, compress
);
869 BP_SET_CHECKSUM(bp
, zp
->zp_checksum
);
870 BP_SET_TYPE(bp
, zp
->zp_type
);
871 BP_SET_LEVEL(bp
, zp
->zp_level
);
872 BP_SET_BYTEORDER(bp
, ZFS_HOST_BYTEORDER
);
875 return (ZIO_PIPELINE_CONTINUE
);
879 * ==========================================================================
880 * Execute the I/O pipeline
881 * ==========================================================================
885 zio_taskq_dispatch(zio_t
*zio
, enum zio_taskq_type q
)
887 zio_type_t t
= zio
->io_type
;
890 * If we're a config writer, the normal issue and interrupt threads
891 * may all be blocked waiting for the config lock. In this case,
892 * select the otherwise-unused taskq for ZIO_TYPE_NULL.
894 if (zio
->io_flags
& ZIO_FLAG_CONFIG_WRITER
)
898 * A similar issue exists for the L2ARC write thread until L2ARC 2.0.
900 if (t
== ZIO_TYPE_WRITE
&& zio
->io_vd
&& zio
->io_vd
->vdev_aux
)
903 (void) taskq_dispatch(zio
->io_spa
->spa_zio_taskq
[t
][q
],
904 (task_func_t
*)zio_execute
, zio
, TQ_SLEEP
);
908 zio_taskq_member(zio_t
*zio
, enum zio_taskq_type q
)
910 kthread_t
*executor
= zio
->io_executor
;
911 spa_t
*spa
= zio
->io_spa
;
913 for (zio_type_t t
= 0; t
< ZIO_TYPES
; t
++)
914 if (taskq_member(spa
->spa_zio_taskq
[t
][q
], executor
))
921 zio_issue_async(zio_t
*zio
)
923 zio_taskq_dispatch(zio
, ZIO_TASKQ_ISSUE
);
925 return (ZIO_PIPELINE_STOP
);
929 zio_interrupt(zio_t
*zio
)
931 zio_taskq_dispatch(zio
, ZIO_TASKQ_INTERRUPT
);
935 * Execute the I/O pipeline until one of the following occurs:
936 * (1) the I/O completes; (2) the pipeline stalls waiting for
937 * dependent child I/Os; (3) the I/O issues, so we're waiting
938 * for an I/O completion interrupt; (4) the I/O is delegated by
939 * vdev-level caching or aggregation; (5) the I/O is deferred
940 * due to vdev-level queueing; (6) the I/O is handed off to
941 * another thread. In all cases, the pipeline stops whenever
942 * there's no CPU work; it never burns a thread in cv_wait().
944 * There's no locking on io_stage because there's no legitimate way
945 * for multiple threads to be attempting to process the same I/O.
947 static zio_pipe_stage_t
*zio_pipeline
[ZIO_STAGES
];
950 zio_execute(zio_t
*zio
)
952 zio
->io_executor
= curthread
;
954 while (zio
->io_stage
< ZIO_STAGE_DONE
) {
955 uint32_t pipeline
= zio
->io_pipeline
;
956 zio_stage_t stage
= zio
->io_stage
;
959 ASSERT(!MUTEX_HELD(&zio
->io_lock
));
961 while (((1U << ++stage
) & pipeline
) == 0)
964 ASSERT(stage
<= ZIO_STAGE_DONE
);
965 ASSERT(zio
->io_stall
== NULL
);
968 * If we are in interrupt context and this pipeline stage
969 * will grab a config lock that is held across I/O,
970 * issue async to avoid deadlock.
972 if (((1U << stage
) & ZIO_CONFIG_LOCK_BLOCKING_STAGES
) &&
973 zio
->io_vd
== NULL
&&
974 zio_taskq_member(zio
, ZIO_TASKQ_INTERRUPT
)) {
975 zio_taskq_dispatch(zio
, ZIO_TASKQ_ISSUE
);
979 zio
->io_stage
= stage
;
980 rv
= zio_pipeline
[stage
](zio
);
982 if (rv
== ZIO_PIPELINE_STOP
)
985 ASSERT(rv
== ZIO_PIPELINE_CONTINUE
);
990 * ==========================================================================
991 * Initiate I/O, either sync or async
992 * ==========================================================================
999 ASSERT(zio
->io_stage
== ZIO_STAGE_OPEN
);
1000 ASSERT(zio
->io_executor
== NULL
);
1002 zio
->io_waiter
= curthread
;
1006 mutex_enter(&zio
->io_lock
);
1007 while (zio
->io_executor
!= NULL
)
1008 cv_wait(&zio
->io_cv
, &zio
->io_lock
);
1009 mutex_exit(&zio
->io_lock
);
1011 error
= zio
->io_error
;
1018 zio_nowait(zio_t
*zio
)
1020 ASSERT(zio
->io_executor
== NULL
);
1022 if (zio
->io_parent
== NULL
&& zio
->io_child_type
== ZIO_CHILD_LOGICAL
) {
1024 * This is a logical async I/O with no parent to wait for it.
1025 * Attach it to the pool's global async root zio so that
1026 * spa_unload() has a way of waiting for async I/O to finish.
1028 spa_t
*spa
= zio
->io_spa
;
1029 zio
->io_async_root
= B_TRUE
;
1030 mutex_enter(&spa
->spa_async_root_lock
);
1031 spa
->spa_async_root_count
++;
1032 mutex_exit(&spa
->spa_async_root_lock
);
1039 * ==========================================================================
1040 * Reexecute or suspend/resume failed I/O
1041 * ==========================================================================
1045 zio_reexecute(zio_t
*pio
)
1047 zio_t
*zio
, *zio_next
;
1049 pio
->io_flags
= pio
->io_orig_flags
;
1050 pio
->io_stage
= pio
->io_orig_stage
;
1051 pio
->io_pipeline
= pio
->io_orig_pipeline
;
1052 pio
->io_reexecute
= 0;
1054 for (int c
= 0; c
< ZIO_CHILD_TYPES
; c
++)
1055 pio
->io_child_error
[c
] = 0;
1057 if (IO_IS_ALLOCATING(pio
)) {
1059 * Remember the failed bp so that the io_ready() callback
1060 * can update its accounting upon reexecution. The block
1061 * was already freed in zio_done(); we indicate this with
1062 * a fill count of -1 so that zio_free() knows to skip it.
1064 blkptr_t
*bp
= pio
->io_bp
;
1065 ASSERT(bp
->blk_birth
== 0 || bp
->blk_birth
== pio
->io_txg
);
1066 bp
->blk_fill
= BLK_FILL_ALREADY_FREED
;
1067 pio
->io_bp_orig
= *bp
;
1072 * As we reexecute pio's children, new children could be created.
1073 * New children go to the head of the io_child list, however,
1074 * so we will (correctly) not reexecute them. The key is that
1075 * the remainder of the io_child list, from 'zio_next' onward,
1076 * cannot be affected by any side effects of reexecuting 'zio'.
1078 for (zio
= pio
->io_child
; zio
!= NULL
; zio
= zio_next
) {
1079 zio_next
= zio
->io_sibling_next
;
1080 mutex_enter(&pio
->io_lock
);
1081 pio
->io_children
[zio
->io_child_type
][ZIO_WAIT_READY
]++;
1082 pio
->io_children
[zio
->io_child_type
][ZIO_WAIT_DONE
]++;
1083 mutex_exit(&pio
->io_lock
);
1088 * Now that all children have been reexecuted, execute the parent.
1094 zio_suspend(spa_t
*spa
, zio_t
*zio
)
1096 if (spa_get_failmode(spa
) == ZIO_FAILURE_MODE_PANIC
)
1097 fm_panic("Pool '%s' has encountered an uncorrectable I/O "
1098 "failure and the failure mode property for this pool "
1099 "is set to panic.", spa_name(spa
));
1101 zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE
, spa
, NULL
, NULL
, 0, 0);
1103 mutex_enter(&spa
->spa_suspend_lock
);
1105 if (spa
->spa_suspend_zio_root
== NULL
)
1106 spa
->spa_suspend_zio_root
= zio_root(spa
, NULL
, NULL
, 0);
1108 spa
->spa_suspended
= B_TRUE
;
1111 ASSERT(zio
!= spa
->spa_suspend_zio_root
);
1112 ASSERT(zio
->io_child_type
== ZIO_CHILD_LOGICAL
);
1113 ASSERT(zio
->io_parent
== NULL
);
1114 ASSERT(zio
->io_stage
== ZIO_STAGE_DONE
);
1115 zio_add_child(spa
->spa_suspend_zio_root
, zio
);
1118 mutex_exit(&spa
->spa_suspend_lock
);
1122 zio_resume(spa_t
*spa
)
1127 * Reexecute all previously suspended i/o.
1129 mutex_enter(&spa
->spa_suspend_lock
);
1130 spa
->spa_suspended
= B_FALSE
;
1131 cv_broadcast(&spa
->spa_suspend_cv
);
1132 pio
= spa
->spa_suspend_zio_root
;
1133 spa
->spa_suspend_zio_root
= NULL
;
1134 mutex_exit(&spa
->spa_suspend_lock
);
1139 while ((zio
= pio
->io_child
) != NULL
) {
1140 zio_remove_child(pio
, zio
);
1141 zio
->io_parent
= NULL
;
1145 ASSERT(pio
->io_children
[ZIO_CHILD_LOGICAL
][ZIO_WAIT_DONE
] == 0);
1147 (void) zio_wait(pio
);
1151 zio_resume_wait(spa_t
*spa
)
1153 mutex_enter(&spa
->spa_suspend_lock
);
1154 while (spa_suspended(spa
))
1155 cv_wait(&spa
->spa_suspend_cv
, &spa
->spa_suspend_lock
);
1156 mutex_exit(&spa
->spa_suspend_lock
);
1160 * ==========================================================================
1163 * A gang block is a collection of small blocks that looks to the DMU
1164 * like one large block. When zio_dva_allocate() cannot find a block
1165 * of the requested size, due to either severe fragmentation or the pool
1166 * being nearly full, it calls zio_write_gang_block() to construct the
1167 * block from smaller fragments.
1169 * A gang block consists of a gang header (zio_gbh_phys_t) and up to
1170 * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like
1171 * an indirect block: it's an array of block pointers. It consumes
1172 * only one sector and hence is allocatable regardless of fragmentation.
1173 * The gang header's bps point to its gang members, which hold the data.
1175 * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg>
1176 * as the verifier to ensure uniqueness of the SHA256 checksum.
1177 * Critically, the gang block bp's blk_cksum is the checksum of the data,
1178 * not the gang header. This ensures that data block signatures (needed for
1179 * deduplication) are independent of how the block is physically stored.
1181 * Gang blocks can be nested: a gang member may itself be a gang block.
1182 * Thus every gang block is a tree in which root and all interior nodes are
1183 * gang headers, and the leaves are normal blocks that contain user data.
1184 * The root of the gang tree is called the gang leader.
1186 * To perform any operation (read, rewrite, free, claim) on a gang block,
1187 * zio_gang_assemble() first assembles the gang tree (minus data leaves)
1188 * in the io_gang_tree field of the original logical i/o by recursively
1189 * reading the gang leader and all gang headers below it. This yields
1190 * an in-core tree containing the contents of every gang header and the
1191 * bps for every constituent of the gang block.
1193 * With the gang tree now assembled, zio_gang_issue() just walks the gang tree
1194 * and invokes a callback on each bp. To free a gang block, zio_gang_issue()
1195 * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp.
1196 * zio_claim_gang() provides a similarly trivial wrapper for zio_claim().
1197 * zio_read_gang() is a wrapper around zio_read() that omits reading gang
1198 * headers, since we already have those in io_gang_tree. zio_rewrite_gang()
1199 * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite()
1200 * of the gang header plus zio_checksum_compute() of the data to update the
1201 * gang header's blk_cksum as described above.
1203 * The two-phase assemble/issue model solves the problem of partial failure --
1204 * what if you'd freed part of a gang block but then couldn't read the
1205 * gang header for another part? Assembling the entire gang tree first
1206 * ensures that all the necessary gang header I/O has succeeded before
1207 * starting the actual work of free, claim, or write. Once the gang tree
1208 * is assembled, free and claim are in-memory operations that cannot fail.
1210 * In the event that a gang write fails, zio_dva_unallocate() walks the
1211 * gang tree to immediately free (i.e. insert back into the space map)
1212 * everything we've allocated. This ensures that we don't get ENOSPC
1213 * errors during repeated suspend/resume cycles due to a flaky device.
1215 * Gang rewrites only happen during sync-to-convergence. If we can't assemble
1216 * the gang tree, we won't modify the block, so we can safely defer the free
1217 * (knowing that the block is still intact). If we *can* assemble the gang
1218 * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free
1219 * each constituent bp and we can allocate a new block on the next sync pass.
1221 * In all cases, the gang tree allows complete recovery from partial failure.
1222 * ==========================================================================
1226 zio_read_gang(zio_t
*pio
, blkptr_t
*bp
, zio_gang_node_t
*gn
, void *data
)
1231 return (zio_read(pio
, pio
->io_spa
, bp
, data
, BP_GET_PSIZE(bp
),
1232 NULL
, NULL
, pio
->io_priority
, ZIO_GANG_CHILD_FLAGS(pio
),
1233 &pio
->io_bookmark
));
1237 zio_rewrite_gang(zio_t
*pio
, blkptr_t
*bp
, zio_gang_node_t
*gn
, void *data
)
1242 zio
= zio_rewrite(pio
, pio
->io_spa
, pio
->io_txg
, bp
,
1243 gn
->gn_gbh
, SPA_GANGBLOCKSIZE
, NULL
, NULL
, pio
->io_priority
,
1244 ZIO_GANG_CHILD_FLAGS(pio
), &pio
->io_bookmark
);
1246 * As we rewrite each gang header, the pipeline will compute
1247 * a new gang block header checksum for it; but no one will
1248 * compute a new data checksum, so we do that here. The one
1249 * exception is the gang leader: the pipeline already computed
1250 * its data checksum because that stage precedes gang assembly.
1251 * (Presently, nothing actually uses interior data checksums;
1252 * this is just good hygiene.)
1254 if (gn
!= pio
->io_logical
->io_gang_tree
) {
1255 zio_checksum_compute(zio
, BP_GET_CHECKSUM(bp
),
1256 data
, BP_GET_PSIZE(bp
));
1259 zio
= zio_rewrite(pio
, pio
->io_spa
, pio
->io_txg
, bp
,
1260 data
, BP_GET_PSIZE(bp
), NULL
, NULL
, pio
->io_priority
,
1261 ZIO_GANG_CHILD_FLAGS(pio
), &pio
->io_bookmark
);
1269 zio_free_gang(zio_t
*pio
, blkptr_t
*bp
, zio_gang_node_t
*gn
, void *data
)
1271 return (zio_free(pio
, pio
->io_spa
, pio
->io_txg
, bp
,
1272 NULL
, NULL
, ZIO_GANG_CHILD_FLAGS(pio
)));
1277 zio_claim_gang(zio_t
*pio
, blkptr_t
*bp
, zio_gang_node_t
*gn
, void *data
)
1279 return (zio_claim(pio
, pio
->io_spa
, pio
->io_txg
, bp
,
1280 NULL
, NULL
, ZIO_GANG_CHILD_FLAGS(pio
)));
1283 static zio_gang_issue_func_t
*zio_gang_issue_func
[ZIO_TYPES
] = {
1292 static void zio_gang_tree_assemble_done(zio_t
*zio
);
1294 static zio_gang_node_t
*
1295 zio_gang_node_alloc(zio_gang_node_t
**gnpp
)
1297 zio_gang_node_t
*gn
;
1299 ASSERT(*gnpp
== NULL
);
1301 gn
= kmem_zalloc(sizeof (*gn
), KM_SLEEP
);
1302 gn
->gn_gbh
= zio_buf_alloc(SPA_GANGBLOCKSIZE
);
1309 zio_gang_node_free(zio_gang_node_t
**gnpp
)
1311 zio_gang_node_t
*gn
= *gnpp
;
1313 for (int g
= 0; g
< SPA_GBH_NBLKPTRS
; g
++)
1314 ASSERT(gn
->gn_child
[g
] == NULL
);
1316 zio_buf_free(gn
->gn_gbh
, SPA_GANGBLOCKSIZE
);
1317 kmem_free(gn
, sizeof (*gn
));
1322 zio_gang_tree_free(zio_gang_node_t
**gnpp
)
1324 zio_gang_node_t
*gn
= *gnpp
;
1329 for (int g
= 0; g
< SPA_GBH_NBLKPTRS
; g
++)
1330 zio_gang_tree_free(&gn
->gn_child
[g
]);
1332 zio_gang_node_free(gnpp
);
1336 zio_gang_tree_assemble(zio_t
*lio
, blkptr_t
*bp
, zio_gang_node_t
**gnpp
)
1338 zio_gang_node_t
*gn
= zio_gang_node_alloc(gnpp
);
1340 ASSERT(lio
->io_logical
== lio
);
1341 ASSERT(BP_IS_GANG(bp
));
1343 zio_nowait(zio_read(lio
, lio
->io_spa
, bp
, gn
->gn_gbh
,
1344 SPA_GANGBLOCKSIZE
, zio_gang_tree_assemble_done
, gn
,
1345 lio
->io_priority
, ZIO_GANG_CHILD_FLAGS(lio
), &lio
->io_bookmark
));
1349 zio_gang_tree_assemble_done(zio_t
*zio
)
1351 zio_t
*lio
= zio
->io_logical
;
1352 zio_gang_node_t
*gn
= zio
->io_private
;
1353 blkptr_t
*bp
= zio
->io_bp
;
1355 ASSERT(zio
->io_parent
== lio
);
1356 ASSERT(zio
->io_child
== NULL
);
1361 if (BP_SHOULD_BYTESWAP(bp
))
1362 byteswap_uint64_array(zio
->io_data
, zio
->io_size
);
1364 ASSERT(zio
->io_data
== gn
->gn_gbh
);
1365 ASSERT(zio
->io_size
== SPA_GANGBLOCKSIZE
);
1366 ASSERT(gn
->gn_gbh
->zg_tail
.zbt_magic
== ZBT_MAGIC
);
1368 for (int g
= 0; g
< SPA_GBH_NBLKPTRS
; g
++) {
1369 blkptr_t
*gbp
= &gn
->gn_gbh
->zg_blkptr
[g
];
1370 if (!BP_IS_GANG(gbp
))
1372 zio_gang_tree_assemble(lio
, gbp
, &gn
->gn_child
[g
]);
1377 zio_gang_tree_issue(zio_t
*pio
, zio_gang_node_t
*gn
, blkptr_t
*bp
, void *data
)
1379 zio_t
*lio
= pio
->io_logical
;
1382 ASSERT(BP_IS_GANG(bp
) == !!gn
);
1383 ASSERT(BP_GET_CHECKSUM(bp
) == BP_GET_CHECKSUM(lio
->io_bp
));
1384 ASSERT(BP_GET_LSIZE(bp
) == BP_GET_PSIZE(bp
) || gn
== lio
->io_gang_tree
);
1387 * If you're a gang header, your data is in gn->gn_gbh.
1388 * If you're a gang member, your data is in 'data' and gn == NULL.
1390 zio
= zio_gang_issue_func
[lio
->io_type
](pio
, bp
, gn
, data
);
1393 ASSERT(gn
->gn_gbh
->zg_tail
.zbt_magic
== ZBT_MAGIC
);
1395 for (int g
= 0; g
< SPA_GBH_NBLKPTRS
; g
++) {
1396 blkptr_t
*gbp
= &gn
->gn_gbh
->zg_blkptr
[g
];
1397 if (BP_IS_HOLE(gbp
))
1399 zio_gang_tree_issue(zio
, gn
->gn_child
[g
], gbp
, data
);
1400 data
= (char *)data
+ BP_GET_PSIZE(gbp
);
1404 if (gn
== lio
->io_gang_tree
)
1405 ASSERT3P((char *)lio
->io_data
+ lio
->io_size
, ==, data
);
1412 zio_gang_assemble(zio_t
*zio
)
1414 blkptr_t
*bp
= zio
->io_bp
;
1416 ASSERT(BP_IS_GANG(bp
) && zio
== zio
->io_logical
);
1418 zio_gang_tree_assemble(zio
, bp
, &zio
->io_gang_tree
);
1420 return (ZIO_PIPELINE_CONTINUE
);
1424 zio_gang_issue(zio_t
*zio
)
1426 zio_t
*lio
= zio
->io_logical
;
1427 blkptr_t
*bp
= zio
->io_bp
;
1429 if (zio_wait_for_children(zio
, ZIO_CHILD_GANG
, ZIO_WAIT_DONE
))
1430 return (ZIO_PIPELINE_STOP
);
1432 ASSERT(BP_IS_GANG(bp
) && zio
== lio
);
1434 if (zio
->io_child_error
[ZIO_CHILD_GANG
] == 0)
1435 zio_gang_tree_issue(lio
, lio
->io_gang_tree
, bp
, lio
->io_data
);
1437 zio_gang_tree_free(&lio
->io_gang_tree
);
1439 zio
->io_pipeline
= ZIO_INTERLOCK_PIPELINE
;
1441 return (ZIO_PIPELINE_CONTINUE
);
1445 zio_write_gang_member_ready(zio_t
*zio
)
1447 zio_t
*pio
= zio
->io_parent
;
1448 zio_t
*lio
= zio
->io_logical
;
1449 dva_t
*cdva
= zio
->io_bp
->blk_dva
;
1450 dva_t
*pdva
= pio
->io_bp
->blk_dva
;
1453 if (BP_IS_HOLE(zio
->io_bp
))
1456 ASSERT(BP_IS_HOLE(&zio
->io_bp_orig
));
1458 ASSERT(zio
->io_child_type
== ZIO_CHILD_GANG
);
1459 ASSERT3U(zio
->io_prop
.zp_ndvas
, ==, lio
->io_prop
.zp_ndvas
);
1460 ASSERT3U(zio
->io_prop
.zp_ndvas
, <=, BP_GET_NDVAS(zio
->io_bp
));
1461 ASSERT3U(pio
->io_prop
.zp_ndvas
, <=, BP_GET_NDVAS(pio
->io_bp
));
1462 ASSERT3U(BP_GET_NDVAS(zio
->io_bp
), <=, BP_GET_NDVAS(pio
->io_bp
));
1464 mutex_enter(&pio
->io_lock
);
1465 for (int d
= 0; d
< BP_GET_NDVAS(zio
->io_bp
); d
++) {
1466 ASSERT(DVA_GET_GANG(&pdva
[d
]));
1467 asize
= DVA_GET_ASIZE(&pdva
[d
]);
1468 asize
+= DVA_GET_ASIZE(&cdva
[d
]);
1469 DVA_SET_ASIZE(&pdva
[d
], asize
);
1471 mutex_exit(&pio
->io_lock
);
1475 zio_write_gang_block(zio_t
*pio
)
1477 spa_t
*spa
= pio
->io_spa
;
1478 blkptr_t
*bp
= pio
->io_bp
;
1479 zio_t
*lio
= pio
->io_logical
;
1481 zio_gang_node_t
*gn
, **gnpp
;
1482 zio_gbh_phys_t
*gbh
;
1483 uint64_t txg
= pio
->io_txg
;
1484 uint64_t resid
= pio
->io_size
;
1486 int ndvas
= lio
->io_prop
.zp_ndvas
;
1487 int gbh_ndvas
= MIN(ndvas
+ 1, spa_max_replication(spa
));
1491 error
= metaslab_alloc(spa
, spa
->spa_normal_class
, SPA_GANGBLOCKSIZE
,
1492 bp
, gbh_ndvas
, txg
, pio
== lio
? NULL
: lio
->io_bp
,
1493 METASLAB_HINTBP_FAVOR
| METASLAB_GANG_HEADER
);
1495 pio
->io_error
= error
;
1496 return (ZIO_PIPELINE_CONTINUE
);
1500 gnpp
= &lio
->io_gang_tree
;
1502 gnpp
= pio
->io_private
;
1503 ASSERT(pio
->io_ready
== zio_write_gang_member_ready
);
1506 gn
= zio_gang_node_alloc(gnpp
);
1508 bzero(gbh
, SPA_GANGBLOCKSIZE
);
1511 * Create the gang header.
1513 zio
= zio_rewrite(pio
, spa
, txg
, bp
, gbh
, SPA_GANGBLOCKSIZE
, NULL
, NULL
,
1514 pio
->io_priority
, ZIO_GANG_CHILD_FLAGS(pio
), &pio
->io_bookmark
);
1517 * Create and nowait the gang children.
1519 for (int g
= 0; resid
!= 0; resid
-= lsize
, g
++) {
1520 lsize
= P2ROUNDUP(resid
/ (SPA_GBH_NBLKPTRS
- g
),
1522 ASSERT(lsize
>= SPA_MINBLOCKSIZE
&& lsize
<= resid
);
1524 zp
.zp_checksum
= lio
->io_prop
.zp_checksum
;
1525 zp
.zp_compress
= ZIO_COMPRESS_OFF
;
1526 zp
.zp_type
= DMU_OT_NONE
;
1528 zp
.zp_ndvas
= lio
->io_prop
.zp_ndvas
;
1530 zio_nowait(zio_write(zio
, spa
, txg
, &gbh
->zg_blkptr
[g
],
1531 (char *)pio
->io_data
+ (pio
->io_size
- resid
), lsize
, &zp
,
1532 zio_write_gang_member_ready
, NULL
, &gn
->gn_child
[g
],
1533 pio
->io_priority
, ZIO_GANG_CHILD_FLAGS(pio
),
1534 &pio
->io_bookmark
));
1538 * Set pio's pipeline to just wait for zio to finish.
1540 pio
->io_pipeline
= ZIO_INTERLOCK_PIPELINE
;
1544 return (ZIO_PIPELINE_CONTINUE
);
1548 * ==========================================================================
1549 * Allocate and free blocks
1550 * ==========================================================================
1554 zio_dva_allocate(zio_t
*zio
)
1556 spa_t
*spa
= zio
->io_spa
;
1557 metaslab_class_t
*mc
= spa
->spa_normal_class
;
1558 blkptr_t
*bp
= zio
->io_bp
;
1561 ASSERT(BP_IS_HOLE(bp
));
1562 ASSERT3U(BP_GET_NDVAS(bp
), ==, 0);
1563 ASSERT3U(zio
->io_prop
.zp_ndvas
, >, 0);
1564 ASSERT3U(zio
->io_prop
.zp_ndvas
, <=, spa_max_replication(spa
));
1565 ASSERT3U(zio
->io_size
, ==, BP_GET_PSIZE(bp
));
1567 error
= metaslab_alloc(spa
, mc
, zio
->io_size
, bp
,
1568 zio
->io_prop
.zp_ndvas
, zio
->io_txg
, NULL
, 0);
1571 if (error
== ENOSPC
&& zio
->io_size
> SPA_MINBLOCKSIZE
)
1572 return (zio_write_gang_block(zio
));
1573 zio
->io_error
= error
;
1576 return (ZIO_PIPELINE_CONTINUE
);
1580 zio_dva_free(zio_t
*zio
)
1582 metaslab_free(zio
->io_spa
, zio
->io_bp
, zio
->io_txg
, B_FALSE
);
1584 return (ZIO_PIPELINE_CONTINUE
);
1588 zio_dva_claim(zio_t
*zio
)
1592 error
= metaslab_claim(zio
->io_spa
, zio
->io_bp
, zio
->io_txg
);
1594 zio
->io_error
= error
;
1596 return (ZIO_PIPELINE_CONTINUE
);
1600 * Undo an allocation. This is used by zio_done() when an I/O fails
1601 * and we want to give back the block we just allocated.
1602 * This handles both normal blocks and gang blocks.
1605 zio_dva_unallocate(zio_t
*zio
, zio_gang_node_t
*gn
, blkptr_t
*bp
)
1607 spa_t
*spa
= zio
->io_spa
;
1608 boolean_t now
= !(zio
->io_flags
& ZIO_FLAG_IO_REWRITE
);
1610 ASSERT(bp
->blk_birth
== zio
->io_txg
|| BP_IS_HOLE(bp
));
1612 if (zio
->io_bp
== bp
&& !now
) {
1614 * This is a rewrite for sync-to-convergence.
1615 * We can't do a metaslab_free(NOW) because bp wasn't allocated
1616 * during this sync pass, which means that metaslab_sync()
1617 * already committed the allocation.
1619 ASSERT(DVA_EQUAL(BP_IDENTITY(bp
),
1620 BP_IDENTITY(&zio
->io_bp_orig
)));
1621 ASSERT(spa_sync_pass(spa
) > 1);
1623 if (BP_IS_GANG(bp
) && gn
== NULL
) {
1625 * This is a gang leader whose gang header(s) we
1626 * couldn't read now, so defer the free until later.
1627 * The block should still be intact because without
1628 * the headers, we'd never even start the rewrite.
1630 bplist_enqueue_deferred(&spa
->spa_sync_bplist
, bp
);
1635 if (!BP_IS_HOLE(bp
))
1636 metaslab_free(spa
, bp
, bp
->blk_birth
, now
);
1639 for (int g
= 0; g
< SPA_GBH_NBLKPTRS
; g
++) {
1640 zio_dva_unallocate(zio
, gn
->gn_child
[g
],
1641 &gn
->gn_gbh
->zg_blkptr
[g
]);
1647 * Try to allocate an intent log block. Return 0 on success, errno on failure.
1650 zio_alloc_blk(spa_t
*spa
, uint64_t size
, blkptr_t
*new_bp
, blkptr_t
*old_bp
,
1655 error
= metaslab_alloc(spa
, spa
->spa_log_class
, size
,
1656 new_bp
, 1, txg
, old_bp
, METASLAB_HINTBP_AVOID
);
1659 error
= metaslab_alloc(spa
, spa
->spa_normal_class
, size
,
1660 new_bp
, 1, txg
, old_bp
, METASLAB_HINTBP_AVOID
);
1663 BP_SET_LSIZE(new_bp
, size
);
1664 BP_SET_PSIZE(new_bp
, size
);
1665 BP_SET_COMPRESS(new_bp
, ZIO_COMPRESS_OFF
);
1666 BP_SET_CHECKSUM(new_bp
, ZIO_CHECKSUM_ZILOG
);
1667 BP_SET_TYPE(new_bp
, DMU_OT_INTENT_LOG
);
1668 BP_SET_LEVEL(new_bp
, 0);
1669 BP_SET_BYTEORDER(new_bp
, ZFS_HOST_BYTEORDER
);
1676 * Free an intent log block. We know it can't be a gang block, so there's
1677 * nothing to do except metaslab_free() it.
1680 zio_free_blk(spa_t
*spa
, blkptr_t
*bp
, uint64_t txg
)
1682 ASSERT(!BP_IS_GANG(bp
));
1684 metaslab_free(spa
, bp
, txg
, B_FALSE
);
1688 * ==========================================================================
1689 * Read and write to physical devices
1690 * ==========================================================================
1694 zio_vdev_io_probe_done(zio_t
*zio
)
1697 vdev_t
*vd
= zio
->io_private
;
1699 mutex_enter(&vd
->vdev_probe_lock
);
1700 ASSERT(vd
->vdev_probe_zio
== zio
);
1701 vd
->vdev_probe_zio
= NULL
;
1702 mutex_exit(&vd
->vdev_probe_lock
);
1704 while ((dio
= zio
->io_delegate_list
) != NULL
) {
1705 zio
->io_delegate_list
= dio
->io_delegate_next
;
1706 dio
->io_delegate_next
= NULL
;
1707 if (!vdev_accessible(vd
, dio
))
1708 dio
->io_error
= ENXIO
;
1714 * Probe the device to determine whether I/O failure is specific to this
1715 * zio (e.g. a bad sector) or affects the entire vdev (e.g. unplugged).
1718 zio_vdev_io_probe(zio_t
*zio
)
1720 vdev_t
*vd
= zio
->io_vd
;
1722 boolean_t created_pio
= B_FALSE
;
1725 * Don't probe the probe.
1727 if (zio
->io_flags
& ZIO_FLAG_PROBE
)
1728 return (ZIO_PIPELINE_CONTINUE
);
1731 * To prevent 'probe storms' when a device fails, we create
1732 * just one probe i/o at a time. All zios that want to probe
1733 * this vdev will join the probe zio's io_delegate_list.
1735 mutex_enter(&vd
->vdev_probe_lock
);
1737 if ((pio
= vd
->vdev_probe_zio
) == NULL
) {
1738 vd
->vdev_probe_zio
= pio
= zio_root(zio
->io_spa
,
1739 zio_vdev_io_probe_done
, vd
, ZIO_FLAG_CANFAIL
);
1740 created_pio
= B_TRUE
;
1741 vd
->vdev_probe_wanted
= B_TRUE
;
1742 spa_async_request(zio
->io_spa
, SPA_ASYNC_PROBE
);
1745 zio
->io_delegate_next
= pio
->io_delegate_list
;
1746 pio
->io_delegate_list
= zio
;
1748 mutex_exit(&vd
->vdev_probe_lock
);
1751 zio_nowait(vdev_probe(vd
, pio
));
1755 return (ZIO_PIPELINE_STOP
);
1759 zio_vdev_io_start(zio_t
*zio
)
1761 vdev_t
*vd
= zio
->io_vd
;
1763 spa_t
*spa
= zio
->io_spa
;
1765 ASSERT(zio
->io_error
== 0);
1766 ASSERT(zio
->io_child_error
[ZIO_CHILD_VDEV
] == 0);
1769 if (!(zio
->io_flags
& ZIO_FLAG_CONFIG_WRITER
))
1770 spa_config_enter(spa
, SCL_ZIO
, zio
, RW_READER
);
1773 * The mirror_ops handle multiple DVAs in a single BP.
1775 return (vdev_mirror_ops
.vdev_op_io_start(zio
));
1778 align
= 1ULL << vd
->vdev_top
->vdev_ashift
;
1780 if (P2PHASE(zio
->io_size
, align
) != 0) {
1781 uint64_t asize
= P2ROUNDUP(zio
->io_size
, align
);
1782 char *abuf
= zio_buf_alloc(asize
);
1783 ASSERT(vd
== vd
->vdev_top
);
1784 if (zio
->io_type
== ZIO_TYPE_WRITE
) {
1785 bcopy(zio
->io_data
, abuf
, zio
->io_size
);
1786 bzero(abuf
+ zio
->io_size
, asize
- zio
->io_size
);
1788 zio_push_transform(zio
, abuf
, asize
, asize
, zio_subblock
);
1791 ASSERT(P2PHASE(zio
->io_offset
, align
) == 0);
1792 ASSERT(P2PHASE(zio
->io_size
, align
) == 0);
1793 ASSERT(zio
->io_type
!= ZIO_TYPE_WRITE
|| (spa_mode
& FWRITE
));
1795 if (vd
->vdev_ops
->vdev_op_leaf
&&
1796 (zio
->io_type
== ZIO_TYPE_READ
|| zio
->io_type
== ZIO_TYPE_WRITE
)) {
1798 if (zio
->io_type
== ZIO_TYPE_READ
&& vdev_cache_read(zio
) == 0)
1799 return (ZIO_PIPELINE_STOP
);
1801 if ((zio
= vdev_queue_io(zio
)) == NULL
)
1802 return (ZIO_PIPELINE_STOP
);
1804 if (!vdev_accessible(vd
, zio
)) {
1805 zio
->io_error
= ENXIO
;
1807 return (ZIO_PIPELINE_STOP
);
1812 return (vd
->vdev_ops
->vdev_op_io_start(zio
));
1816 zio_vdev_io_done(zio_t
*zio
)
1818 vdev_t
*vd
= zio
->io_vd
;
1819 vdev_ops_t
*ops
= vd
? vd
->vdev_ops
: &vdev_mirror_ops
;
1820 boolean_t unexpected_error
= B_FALSE
;
1822 if (zio_wait_for_children(zio
, ZIO_CHILD_VDEV
, ZIO_WAIT_DONE
))
1823 return (ZIO_PIPELINE_STOP
);
1825 ASSERT(zio
->io_type
== ZIO_TYPE_READ
|| zio
->io_type
== ZIO_TYPE_WRITE
);
1827 if (vd
!= NULL
&& vd
->vdev_ops
->vdev_op_leaf
) {
1829 vdev_queue_io_done(zio
);
1831 if (zio
->io_type
== ZIO_TYPE_WRITE
)
1832 vdev_cache_write(zio
);
1834 if (zio_injection_enabled
&& zio
->io_error
== 0)
1835 zio
->io_error
= zio_handle_device_injection(vd
, EIO
);
1837 if (zio_injection_enabled
&& zio
->io_error
== 0)
1838 zio
->io_error
= zio_handle_label_injection(zio
, EIO
);
1840 if (zio
->io_error
) {
1841 if (!vdev_accessible(vd
, zio
)) {
1842 zio
->io_error
= ENXIO
;
1844 unexpected_error
= B_TRUE
;
1849 ops
->vdev_op_io_done(zio
);
1851 if (unexpected_error
)
1852 return (zio_vdev_io_probe(zio
));
1854 return (ZIO_PIPELINE_CONTINUE
);
1858 zio_vdev_io_assess(zio_t
*zio
)
1860 vdev_t
*vd
= zio
->io_vd
;
1862 if (zio_wait_for_children(zio
, ZIO_CHILD_VDEV
, ZIO_WAIT_DONE
))
1863 return (ZIO_PIPELINE_STOP
);
1865 if (vd
== NULL
&& !(zio
->io_flags
& ZIO_FLAG_CONFIG_WRITER
))
1866 spa_config_exit(zio
->io_spa
, SCL_ZIO
, zio
);
1868 if (zio
->io_vsd
!= NULL
) {
1869 zio
->io_vsd_free(zio
);
1873 if (zio_injection_enabled
&& zio
->io_error
== 0)
1874 zio
->io_error
= zio_handle_fault_injection(zio
, EIO
);
1877 * If the I/O failed, determine whether we should attempt to retry it.
1879 if (zio
->io_error
&& vd
== NULL
&&
1880 !(zio
->io_flags
& (ZIO_FLAG_DONT_RETRY
| ZIO_FLAG_IO_RETRY
))) {
1881 ASSERT(!(zio
->io_flags
& ZIO_FLAG_DONT_QUEUE
)); /* not a leaf */
1882 ASSERT(!(zio
->io_flags
& ZIO_FLAG_IO_BYPASS
)); /* not a leaf */
1884 zio
->io_flags
|= ZIO_FLAG_IO_RETRY
|
1885 ZIO_FLAG_DONT_CACHE
| ZIO_FLAG_DONT_AGGREGATE
;
1886 zio
->io_stage
= ZIO_STAGE_VDEV_IO_START
- 1;
1887 zio_taskq_dispatch(zio
, ZIO_TASKQ_ISSUE
);
1888 return (ZIO_PIPELINE_STOP
);
1892 * If we got an error on a leaf device, convert it to ENXIO
1893 * if the device is not accessible at all.
1895 if (zio
->io_error
&& vd
!= NULL
&& vd
->vdev_ops
->vdev_op_leaf
&&
1896 !vdev_accessible(vd
, zio
))
1897 zio
->io_error
= ENXIO
;
1900 * If we can't write to an interior vdev (mirror or RAID-Z),
1901 * set vdev_cant_write so that we stop trying to allocate from it.
1903 if (zio
->io_error
== ENXIO
&& zio
->io_type
== ZIO_TYPE_WRITE
&&
1904 vd
!= NULL
&& !vd
->vdev_ops
->vdev_op_leaf
)
1905 vd
->vdev_cant_write
= B_TRUE
;
1908 zio
->io_pipeline
= ZIO_INTERLOCK_PIPELINE
;
1910 return (ZIO_PIPELINE_CONTINUE
);
1914 zio_vdev_io_reissue(zio_t
*zio
)
1916 ASSERT(zio
->io_stage
== ZIO_STAGE_VDEV_IO_START
);
1917 ASSERT(zio
->io_error
== 0);
1923 zio_vdev_io_redone(zio_t
*zio
)
1925 ASSERT(zio
->io_stage
== ZIO_STAGE_VDEV_IO_DONE
);
1931 zio_vdev_io_bypass(zio_t
*zio
)
1933 ASSERT(zio
->io_stage
== ZIO_STAGE_VDEV_IO_START
);
1934 ASSERT(zio
->io_error
== 0);
1936 zio
->io_flags
|= ZIO_FLAG_IO_BYPASS
;
1937 zio
->io_stage
= ZIO_STAGE_VDEV_IO_ASSESS
- 1;
1941 * ==========================================================================
1942 * Generate and verify checksums
1943 * ==========================================================================
1946 zio_checksum_generate(zio_t
*zio
)
1948 blkptr_t
*bp
= zio
->io_bp
;
1949 enum zio_checksum checksum
;
1953 * This is zio_write_phys().
1954 * We're either generating a label checksum, or none at all.
1956 checksum
= zio
->io_prop
.zp_checksum
;
1958 if (checksum
== ZIO_CHECKSUM_OFF
)
1959 return (ZIO_PIPELINE_CONTINUE
);
1961 ASSERT(checksum
== ZIO_CHECKSUM_LABEL
);
1963 if (BP_IS_GANG(bp
) && zio
->io_child_type
== ZIO_CHILD_GANG
) {
1964 ASSERT(!IO_IS_ALLOCATING(zio
));
1965 checksum
= ZIO_CHECKSUM_GANG_HEADER
;
1967 checksum
= BP_GET_CHECKSUM(bp
);
1971 zio_checksum_compute(zio
, checksum
, zio
->io_data
, zio
->io_size
);
1973 return (ZIO_PIPELINE_CONTINUE
);
1977 zio_checksum_verify(zio_t
*zio
)
1979 blkptr_t
*bp
= zio
->io_bp
;
1984 * This is zio_read_phys().
1985 * We're either verifying a label checksum, or nothing at all.
1987 if (zio
->io_prop
.zp_checksum
== ZIO_CHECKSUM_OFF
)
1988 return (ZIO_PIPELINE_CONTINUE
);
1990 ASSERT(zio
->io_prop
.zp_checksum
== ZIO_CHECKSUM_LABEL
);
1993 if ((error
= zio_checksum_error(zio
)) != 0) {
1994 zio
->io_error
= error
;
1995 if (!(zio
->io_flags
& ZIO_FLAG_SPECULATIVE
)) {
1996 zfs_ereport_post(FM_EREPORT_ZFS_CHECKSUM
,
1997 zio
->io_spa
, zio
->io_vd
, zio
, 0, 0);
2001 return (ZIO_PIPELINE_CONTINUE
);
2005 * Called by RAID-Z to ensure we don't compute the checksum twice.
2008 zio_checksum_verified(zio_t
*zio
)
2010 zio
->io_pipeline
&= ~(1U << ZIO_STAGE_CHECKSUM_VERIFY
);
2014 * ==========================================================================
2015 * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other.
2016 * An error of 0 indictes success. ENXIO indicates whole-device failure,
2017 * which may be transient (e.g. unplugged) or permament. ECKSUM and EIO
2018 * indicate errors that are specific to one I/O, and most likely permanent.
2019 * Any other error is presumed to be worse because we weren't expecting it.
2020 * ==========================================================================
2023 zio_worst_error(int e1
, int e2
)
2025 static int zio_error_rank
[] = { 0, ENXIO
, ECKSUM
, EIO
};
2028 for (r1
= 0; r1
< sizeof (zio_error_rank
) / sizeof (int); r1
++)
2029 if (e1
== zio_error_rank
[r1
])
2032 for (r2
= 0; r2
< sizeof (zio_error_rank
) / sizeof (int); r2
++)
2033 if (e2
== zio_error_rank
[r2
])
2036 return (r1
> r2
? e1
: e2
);
2040 * ==========================================================================
2042 * ==========================================================================
2045 zio_ready(zio_t
*zio
)
2047 blkptr_t
*bp
= zio
->io_bp
;
2048 zio_t
*pio
= zio
->io_parent
;
2050 if (zio
->io_ready
) {
2051 if (BP_IS_GANG(bp
) &&
2052 zio_wait_for_children(zio
, ZIO_CHILD_GANG
, ZIO_WAIT_READY
))
2053 return (ZIO_PIPELINE_STOP
);
2055 ASSERT(IO_IS_ALLOCATING(zio
));
2056 ASSERT(bp
->blk_birth
== zio
->io_txg
|| BP_IS_HOLE(bp
));
2057 ASSERT(zio
->io_children
[ZIO_CHILD_GANG
][ZIO_WAIT_READY
] == 0);
2062 if (bp
!= NULL
&& bp
!= &zio
->io_bp_copy
)
2063 zio
->io_bp_copy
= *bp
;
2066 zio
->io_pipeline
= ZIO_INTERLOCK_PIPELINE
;
2069 zio_notify_parent(pio
, zio
, ZIO_WAIT_READY
);
2071 return (ZIO_PIPELINE_CONTINUE
);
2075 zio_done(zio_t
*zio
)
2077 spa_t
*spa
= zio
->io_spa
;
2078 zio_t
*pio
= zio
->io_parent
;
2079 zio_t
*lio
= zio
->io_logical
;
2080 blkptr_t
*bp
= zio
->io_bp
;
2081 vdev_t
*vd
= zio
->io_vd
;
2082 uint64_t psize
= zio
->io_size
;
2085 * If our of children haven't all completed,
2086 * wait for them and then repeat this pipeline stage.
2088 if (zio_wait_for_children(zio
, ZIO_CHILD_VDEV
, ZIO_WAIT_DONE
) ||
2089 zio_wait_for_children(zio
, ZIO_CHILD_GANG
, ZIO_WAIT_DONE
) ||
2090 zio_wait_for_children(zio
, ZIO_CHILD_LOGICAL
, ZIO_WAIT_DONE
))
2091 return (ZIO_PIPELINE_STOP
);
2093 for (int c
= 0; c
< ZIO_CHILD_TYPES
; c
++)
2094 for (int w
= 0; w
< ZIO_WAIT_TYPES
; w
++)
2095 ASSERT(zio
->io_children
[c
][w
] == 0);
2098 ASSERT(bp
->blk_pad
[0] == 0);
2099 ASSERT(bp
->blk_pad
[1] == 0);
2100 ASSERT(bp
->blk_pad
[2] == 0);
2101 ASSERT(bcmp(bp
, &zio
->io_bp_copy
, sizeof (blkptr_t
)) == 0 ||
2102 (pio
!= NULL
&& bp
== pio
->io_bp
));
2103 if (zio
->io_type
== ZIO_TYPE_WRITE
&& !BP_IS_HOLE(bp
) &&
2104 !(zio
->io_flags
& ZIO_FLAG_IO_REPAIR
)) {
2105 ASSERT(!BP_SHOULD_BYTESWAP(bp
));
2106 ASSERT3U(zio
->io_prop
.zp_ndvas
, <=, BP_GET_NDVAS(bp
));
2107 ASSERT(BP_COUNT_GANG(bp
) == 0 ||
2108 (BP_COUNT_GANG(bp
) == BP_GET_NDVAS(bp
)));
2113 * If there were child vdev or gang errors, they apply to us now.
2115 zio_inherit_child_errors(zio
, ZIO_CHILD_VDEV
);
2116 zio_inherit_child_errors(zio
, ZIO_CHILD_GANG
);
2118 zio_pop_transforms(zio
); /* note: may set zio->io_error */
2120 vdev_stat_update(zio
, psize
);
2122 if (zio
->io_error
) {
2124 * If this I/O is attached to a particular vdev,
2125 * generate an error message describing the I/O failure
2126 * at the block level. We ignore these errors if the
2127 * device is currently unavailable.
2129 if (zio
->io_error
!= ECKSUM
&& vd
!= NULL
&& !vdev_is_dead(vd
))
2130 zfs_ereport_post(FM_EREPORT_ZFS_IO
, spa
, vd
, zio
, 0, 0);
2132 if ((zio
->io_error
== EIO
||
2133 !(zio
->io_flags
& ZIO_FLAG_SPECULATIVE
)) && zio
== lio
) {
2135 * For logical I/O requests, tell the SPA to log the
2136 * error and generate a logical data ereport.
2138 spa_log_error(spa
, zio
);
2139 zfs_ereport_post(FM_EREPORT_ZFS_DATA
, spa
, NULL
, zio
,
2144 if (zio
->io_error
&& zio
== lio
) {
2146 * Determine whether zio should be reexecuted. This will
2147 * propagate all the way to the root via zio_notify_parent().
2149 ASSERT(vd
== NULL
&& bp
!= NULL
);
2151 if (IO_IS_ALLOCATING(zio
))
2152 if (zio
->io_error
!= ENOSPC
)
2153 zio
->io_reexecute
|= ZIO_REEXECUTE_NOW
;
2155 zio
->io_reexecute
|= ZIO_REEXECUTE_SUSPEND
;
2157 if ((zio
->io_type
== ZIO_TYPE_READ
||
2158 zio
->io_type
== ZIO_TYPE_FREE
) &&
2159 zio
->io_error
== ENXIO
&&
2160 spa_get_failmode(spa
) != ZIO_FAILURE_MODE_CONTINUE
)
2161 zio
->io_reexecute
|= ZIO_REEXECUTE_SUSPEND
;
2163 if (!(zio
->io_flags
& ZIO_FLAG_CANFAIL
) && !zio
->io_reexecute
)
2164 zio
->io_reexecute
|= ZIO_REEXECUTE_SUSPEND
;
2168 * If there were logical child errors, they apply to us now.
2169 * We defer this until now to avoid conflating logical child
2170 * errors with errors that happened to the zio itself when
2171 * updating vdev stats and reporting FMA events above.
2173 zio_inherit_child_errors(zio
, ZIO_CHILD_LOGICAL
);
2175 if (zio
->io_reexecute
) {
2177 * This is a logical I/O that wants to reexecute.
2179 * Reexecute is top-down. When an i/o fails, if it's not
2180 * the root, it simply notifies its parent and sticks around.
2181 * The parent, seeing that it still has children in zio_done(),
2182 * does the same. This percolates all the way up to the root.
2183 * The root i/o will reexecute or suspend the entire tree.
2185 * This approach ensures that zio_reexecute() honors
2186 * all the original i/o dependency relationships, e.g.
2187 * parents not executing until children are ready.
2189 ASSERT(zio
->io_child_type
== ZIO_CHILD_LOGICAL
);
2191 if (IO_IS_ALLOCATING(zio
))
2192 zio_dva_unallocate(zio
, zio
->io_gang_tree
, bp
);
2194 zio_gang_tree_free(&zio
->io_gang_tree
);
2198 * We're not a root i/o, so there's nothing to do
2199 * but notify our parent. Don't propagate errors
2200 * upward since we haven't permanently failed yet.
2202 zio
->io_flags
|= ZIO_FLAG_DONT_PROPAGATE
;
2203 zio_notify_parent(pio
, zio
, ZIO_WAIT_DONE
);
2204 } else if (zio
->io_reexecute
& ZIO_REEXECUTE_SUSPEND
) {
2206 * We'd fail again if we reexecuted now, so suspend
2207 * until conditions improve (e.g. device comes online).
2209 zio_suspend(spa
, zio
);
2212 * Reexecution is potentially a huge amount of work.
2213 * Hand it off to the otherwise-unused claim taskq.
2215 (void) taskq_dispatch(
2216 spa
->spa_zio_taskq
[ZIO_TYPE_CLAIM
][ZIO_TASKQ_ISSUE
],
2217 (task_func_t
*)zio_reexecute
, zio
, TQ_SLEEP
);
2219 return (ZIO_PIPELINE_STOP
);
2222 ASSERT(zio
->io_child
== NULL
);
2223 ASSERT(zio
->io_reexecute
== 0);
2224 ASSERT(zio
->io_error
== 0 || (zio
->io_flags
& ZIO_FLAG_CANFAIL
));
2229 zio_gang_tree_free(&zio
->io_gang_tree
);
2231 ASSERT(zio
->io_delegate_list
== NULL
);
2232 ASSERT(zio
->io_delegate_next
== NULL
);
2235 zio_remove_child(pio
, zio
);
2236 zio_notify_parent(pio
, zio
, ZIO_WAIT_DONE
);
2239 if (zio
->io_waiter
!= NULL
) {
2240 mutex_enter(&zio
->io_lock
);
2241 zio
->io_executor
= NULL
;
2242 cv_broadcast(&zio
->io_cv
);
2243 mutex_exit(&zio
->io_lock
);
2248 return (ZIO_PIPELINE_STOP
);
2252 * ==========================================================================
2253 * I/O pipeline definition
2254 * ==========================================================================
2256 static zio_pipe_stage_t
*zio_pipeline
[ZIO_STAGES
] = {
2261 zio_checksum_generate
,
2271 zio_checksum_verify
,