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) 2012 by Delphix. All rights reserved.
24 * Copyright (c) 2011 Nexenta Systems, Inc. All rights reserved.
27 #include <sys/zfs_context.h>
28 #include <sys/fm/fs/zfs.h>
31 #include <sys/spa_impl.h>
32 #include <sys/vdev_impl.h>
33 #include <sys/zio_impl.h>
34 #include <sys/zio_compress.h>
35 #include <sys/zio_checksum.h>
36 #include <sys/dmu_objset.h>
41 * ==========================================================================
43 * ==========================================================================
45 uint8_t zio_priority_table
[ZIO_PRIORITY_TABLE_SIZE
] = {
46 0, /* ZIO_PRIORITY_NOW */
47 0, /* ZIO_PRIORITY_SYNC_READ */
48 0, /* ZIO_PRIORITY_SYNC_WRITE */
49 0, /* ZIO_PRIORITY_LOG_WRITE */
50 1, /* ZIO_PRIORITY_CACHE_FILL */
51 1, /* ZIO_PRIORITY_AGG */
52 4, /* ZIO_PRIORITY_FREE */
53 4, /* ZIO_PRIORITY_ASYNC_WRITE */
54 6, /* ZIO_PRIORITY_ASYNC_READ */
55 10, /* ZIO_PRIORITY_RESILVER */
56 20, /* ZIO_PRIORITY_SCRUB */
57 2, /* ZIO_PRIORITY_DDT_PREFETCH */
61 * ==========================================================================
62 * I/O type descriptions
63 * ==========================================================================
65 char *zio_type_name
[ZIO_TYPES
] = {
66 "z_null", "z_rd", "z_wr", "z_fr", "z_cl", "z_ioctl"
70 * ==========================================================================
72 * ==========================================================================
74 kmem_cache_t
*zio_cache
;
75 kmem_cache_t
*zio_link_cache
;
76 kmem_cache_t
*zio_buf_cache
[SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
];
77 kmem_cache_t
*zio_data_buf_cache
[SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
];
78 int zio_bulk_flags
= 0;
79 int zio_delay_max
= ZIO_DELAY_MAX
;
82 extern vmem_t
*zio_alloc_arena
;
84 extern int zfs_mg_alloc_failures
;
87 * An allocating zio is one that either currently has the DVA allocate
88 * stage set or will have it later in its lifetime.
90 #define IO_IS_ALLOCATING(zio) ((zio)->io_orig_pipeline & ZIO_STAGE_DVA_ALLOCATE)
92 int zio_requeue_io_start_cut_in_line
= 1;
95 int zio_buf_debug_limit
= 16384;
97 int zio_buf_debug_limit
= 0;
100 static inline void __zio_execute(zio_t
*zio
);
103 zio_cons(void *arg
, void *unused
, int kmflag
)
107 bzero(zio
, sizeof (zio_t
));
109 mutex_init(&zio
->io_lock
, NULL
, MUTEX_DEFAULT
, NULL
);
110 cv_init(&zio
->io_cv
, NULL
, CV_DEFAULT
, NULL
);
112 list_create(&zio
->io_parent_list
, sizeof (zio_link_t
),
113 offsetof(zio_link_t
, zl_parent_node
));
114 list_create(&zio
->io_child_list
, sizeof (zio_link_t
),
115 offsetof(zio_link_t
, zl_child_node
));
121 zio_dest(void *arg
, void *unused
)
125 mutex_destroy(&zio
->io_lock
);
126 cv_destroy(&zio
->io_cv
);
127 list_destroy(&zio
->io_parent_list
);
128 list_destroy(&zio
->io_child_list
);
135 vmem_t
*data_alloc_arena
= NULL
;
138 data_alloc_arena
= zio_alloc_arena
;
140 zio_cache
= kmem_cache_create("zio_cache", sizeof (zio_t
), 0,
141 zio_cons
, zio_dest
, NULL
, NULL
, NULL
, KMC_KMEM
);
142 zio_link_cache
= kmem_cache_create("zio_link_cache",
143 sizeof (zio_link_t
), 0, NULL
, NULL
, NULL
, NULL
, NULL
, KMC_KMEM
);
146 * For small buffers, we want a cache for each multiple of
147 * SPA_MINBLOCKSIZE. For medium-size buffers, we want a cache
148 * for each quarter-power of 2. For large buffers, we want
149 * a cache for each multiple of PAGESIZE.
151 for (c
= 0; c
< SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
; c
++) {
152 size_t size
= (c
+ 1) << SPA_MINBLOCKSHIFT
;
156 while (p2
& (p2
- 1))
159 if (size
<= 4 * SPA_MINBLOCKSIZE
) {
160 align
= SPA_MINBLOCKSIZE
;
161 } else if (P2PHASE(size
, PAGESIZE
) == 0) {
163 } else if (P2PHASE(size
, p2
>> 2) == 0) {
169 int flags
= zio_bulk_flags
;
172 * The smallest buffers (512b) are heavily used and
173 * experience a lot of churn. The slabs allocated
174 * for them are also relatively small (32K). Thus
175 * in over to avoid expensive calls to vmalloc() we
176 * make an exception to the usual slab allocation
177 * policy and force these buffers to be kmem backed.
179 if (size
== (1 << SPA_MINBLOCKSHIFT
))
182 (void) sprintf(name
, "zio_buf_%lu", (ulong_t
)size
);
183 zio_buf_cache
[c
] = kmem_cache_create(name
, size
,
184 align
, NULL
, NULL
, NULL
, NULL
, NULL
, flags
);
186 (void) sprintf(name
, "zio_data_buf_%lu", (ulong_t
)size
);
187 zio_data_buf_cache
[c
] = kmem_cache_create(name
, size
,
188 align
, NULL
, NULL
, NULL
, NULL
,
189 data_alloc_arena
, flags
);
194 ASSERT(zio_buf_cache
[c
] != NULL
);
195 if (zio_buf_cache
[c
- 1] == NULL
)
196 zio_buf_cache
[c
- 1] = zio_buf_cache
[c
];
198 ASSERT(zio_data_buf_cache
[c
] != NULL
);
199 if (zio_data_buf_cache
[c
- 1] == NULL
)
200 zio_data_buf_cache
[c
- 1] = zio_data_buf_cache
[c
];
204 * The zio write taskqs have 1 thread per cpu, allow 1/2 of the taskqs
205 * to fail 3 times per txg or 8 failures, whichever is greater.
207 zfs_mg_alloc_failures
= MAX((3 * max_ncpus
/ 2), 8);
216 kmem_cache_t
*last_cache
= NULL
;
217 kmem_cache_t
*last_data_cache
= NULL
;
219 for (c
= 0; c
< SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
; c
++) {
220 if (zio_buf_cache
[c
] != last_cache
) {
221 last_cache
= zio_buf_cache
[c
];
222 kmem_cache_destroy(zio_buf_cache
[c
]);
224 zio_buf_cache
[c
] = NULL
;
226 if (zio_data_buf_cache
[c
] != last_data_cache
) {
227 last_data_cache
= zio_data_buf_cache
[c
];
228 kmem_cache_destroy(zio_data_buf_cache
[c
]);
230 zio_data_buf_cache
[c
] = NULL
;
233 kmem_cache_destroy(zio_link_cache
);
234 kmem_cache_destroy(zio_cache
);
240 * ==========================================================================
241 * Allocate and free I/O buffers
242 * ==========================================================================
246 * Use zio_buf_alloc to allocate ZFS metadata. This data will appear in a
247 * crashdump if the kernel panics, so use it judiciously. Obviously, it's
248 * useful to inspect ZFS metadata, but if possible, we should avoid keeping
249 * excess / transient data in-core during a crashdump.
252 zio_buf_alloc(size_t size
)
254 size_t c
= (size
- 1) >> SPA_MINBLOCKSHIFT
;
256 ASSERT(c
< SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
);
258 return (kmem_cache_alloc(zio_buf_cache
[c
], KM_PUSHPAGE
));
262 * Use zio_data_buf_alloc to allocate data. The data will not appear in a
263 * crashdump if the kernel panics. This exists so that we will limit the amount
264 * of ZFS data that shows up in a kernel crashdump. (Thus reducing the amount
265 * of kernel heap dumped to disk when the kernel panics)
268 zio_data_buf_alloc(size_t size
)
270 size_t c
= (size
- 1) >> SPA_MINBLOCKSHIFT
;
272 ASSERT(c
< SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
);
274 return (kmem_cache_alloc(zio_data_buf_cache
[c
], KM_PUSHPAGE
));
278 zio_buf_free(void *buf
, size_t size
)
280 size_t c
= (size
- 1) >> SPA_MINBLOCKSHIFT
;
282 ASSERT(c
< SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
);
284 kmem_cache_free(zio_buf_cache
[c
], buf
);
288 zio_data_buf_free(void *buf
, size_t size
)
290 size_t c
= (size
- 1) >> SPA_MINBLOCKSHIFT
;
292 ASSERT(c
< SPA_MAXBLOCKSIZE
>> SPA_MINBLOCKSHIFT
);
294 kmem_cache_free(zio_data_buf_cache
[c
], buf
);
298 * ==========================================================================
299 * Push and pop I/O transform buffers
300 * ==========================================================================
303 zio_push_transform(zio_t
*zio
, void *data
, uint64_t size
, uint64_t bufsize
,
304 zio_transform_func_t
*transform
)
306 zio_transform_t
*zt
= kmem_alloc(sizeof (zio_transform_t
), KM_PUSHPAGE
);
308 zt
->zt_orig_data
= zio
->io_data
;
309 zt
->zt_orig_size
= zio
->io_size
;
310 zt
->zt_bufsize
= bufsize
;
311 zt
->zt_transform
= transform
;
313 zt
->zt_next
= zio
->io_transform_stack
;
314 zio
->io_transform_stack
= zt
;
321 zio_pop_transforms(zio_t
*zio
)
325 while ((zt
= zio
->io_transform_stack
) != NULL
) {
326 if (zt
->zt_transform
!= NULL
)
327 zt
->zt_transform(zio
,
328 zt
->zt_orig_data
, zt
->zt_orig_size
);
330 if (zt
->zt_bufsize
!= 0)
331 zio_buf_free(zio
->io_data
, zt
->zt_bufsize
);
333 zio
->io_data
= zt
->zt_orig_data
;
334 zio
->io_size
= zt
->zt_orig_size
;
335 zio
->io_transform_stack
= zt
->zt_next
;
337 kmem_free(zt
, sizeof (zio_transform_t
));
342 * ==========================================================================
343 * I/O transform callbacks for subblocks and decompression
344 * ==========================================================================
347 zio_subblock(zio_t
*zio
, void *data
, uint64_t size
)
349 ASSERT(zio
->io_size
> size
);
351 if (zio
->io_type
== ZIO_TYPE_READ
)
352 bcopy(zio
->io_data
, data
, size
);
356 zio_decompress(zio_t
*zio
, void *data
, uint64_t size
)
358 if (zio
->io_error
== 0 &&
359 zio_decompress_data(BP_GET_COMPRESS(zio
->io_bp
),
360 zio
->io_data
, data
, zio
->io_size
, size
) != 0)
365 * ==========================================================================
366 * I/O parent/child relationships and pipeline interlocks
367 * ==========================================================================
370 * NOTE - Callers to zio_walk_parents() and zio_walk_children must
371 * continue calling these functions until they return NULL.
372 * Otherwise, the next caller will pick up the list walk in
373 * some indeterminate state. (Otherwise every caller would
374 * have to pass in a cookie to keep the state represented by
375 * io_walk_link, which gets annoying.)
378 zio_walk_parents(zio_t
*cio
)
380 zio_link_t
*zl
= cio
->io_walk_link
;
381 list_t
*pl
= &cio
->io_parent_list
;
383 zl
= (zl
== NULL
) ? list_head(pl
) : list_next(pl
, zl
);
384 cio
->io_walk_link
= zl
;
389 ASSERT(zl
->zl_child
== cio
);
390 return (zl
->zl_parent
);
394 zio_walk_children(zio_t
*pio
)
396 zio_link_t
*zl
= pio
->io_walk_link
;
397 list_t
*cl
= &pio
->io_child_list
;
399 zl
= (zl
== NULL
) ? list_head(cl
) : list_next(cl
, zl
);
400 pio
->io_walk_link
= zl
;
405 ASSERT(zl
->zl_parent
== pio
);
406 return (zl
->zl_child
);
410 zio_unique_parent(zio_t
*cio
)
412 zio_t
*pio
= zio_walk_parents(cio
);
414 VERIFY(zio_walk_parents(cio
) == NULL
);
419 zio_add_child(zio_t
*pio
, zio_t
*cio
)
421 zio_link_t
*zl
= kmem_cache_alloc(zio_link_cache
, KM_PUSHPAGE
);
425 * Logical I/Os can have logical, gang, or vdev children.
426 * Gang I/Os can have gang or vdev children.
427 * Vdev I/Os can only have vdev children.
428 * The following ASSERT captures all of these constraints.
430 ASSERT(cio
->io_child_type
<= pio
->io_child_type
);
435 mutex_enter(&cio
->io_lock
);
436 mutex_enter(&pio
->io_lock
);
438 ASSERT(pio
->io_state
[ZIO_WAIT_DONE
] == 0);
440 for (w
= 0; w
< ZIO_WAIT_TYPES
; w
++)
441 pio
->io_children
[cio
->io_child_type
][w
] += !cio
->io_state
[w
];
443 list_insert_head(&pio
->io_child_list
, zl
);
444 list_insert_head(&cio
->io_parent_list
, zl
);
446 pio
->io_child_count
++;
447 cio
->io_parent_count
++;
449 mutex_exit(&pio
->io_lock
);
450 mutex_exit(&cio
->io_lock
);
454 zio_remove_child(zio_t
*pio
, zio_t
*cio
, zio_link_t
*zl
)
456 ASSERT(zl
->zl_parent
== pio
);
457 ASSERT(zl
->zl_child
== cio
);
459 mutex_enter(&cio
->io_lock
);
460 mutex_enter(&pio
->io_lock
);
462 list_remove(&pio
->io_child_list
, zl
);
463 list_remove(&cio
->io_parent_list
, zl
);
465 pio
->io_child_count
--;
466 cio
->io_parent_count
--;
468 mutex_exit(&pio
->io_lock
);
469 mutex_exit(&cio
->io_lock
);
471 kmem_cache_free(zio_link_cache
, zl
);
475 zio_wait_for_children(zio_t
*zio
, enum zio_child child
, enum zio_wait_type wait
)
477 uint64_t *countp
= &zio
->io_children
[child
][wait
];
478 boolean_t waiting
= B_FALSE
;
480 mutex_enter(&zio
->io_lock
);
481 ASSERT(zio
->io_stall
== NULL
);
484 zio
->io_stall
= countp
;
487 mutex_exit(&zio
->io_lock
);
492 __attribute__((always_inline
))
494 zio_notify_parent(zio_t
*pio
, zio_t
*zio
, enum zio_wait_type wait
)
496 uint64_t *countp
= &pio
->io_children
[zio
->io_child_type
][wait
];
497 int *errorp
= &pio
->io_child_error
[zio
->io_child_type
];
499 mutex_enter(&pio
->io_lock
);
500 if (zio
->io_error
&& !(zio
->io_flags
& ZIO_FLAG_DONT_PROPAGATE
))
501 *errorp
= zio_worst_error(*errorp
, zio
->io_error
);
502 pio
->io_reexecute
|= zio
->io_reexecute
;
503 ASSERT3U(*countp
, >, 0);
504 if (--*countp
== 0 && pio
->io_stall
== countp
) {
505 pio
->io_stall
= NULL
;
506 mutex_exit(&pio
->io_lock
);
509 mutex_exit(&pio
->io_lock
);
514 zio_inherit_child_errors(zio_t
*zio
, enum zio_child c
)
516 if (zio
->io_child_error
[c
] != 0 && zio
->io_error
== 0)
517 zio
->io_error
= zio
->io_child_error
[c
];
521 * ==========================================================================
522 * Create the various types of I/O (read, write, free, etc)
523 * ==========================================================================
526 zio_create(zio_t
*pio
, spa_t
*spa
, uint64_t txg
, const blkptr_t
*bp
,
527 void *data
, uint64_t size
, zio_done_func_t
*done
, void *private,
528 zio_type_t type
, int priority
, enum zio_flag flags
,
529 vdev_t
*vd
, uint64_t offset
, const zbookmark_t
*zb
,
530 enum zio_stage stage
, enum zio_stage pipeline
)
534 ASSERT3U(size
, <=, SPA_MAXBLOCKSIZE
);
535 ASSERT(P2PHASE(size
, SPA_MINBLOCKSIZE
) == 0);
536 ASSERT(P2PHASE(offset
, SPA_MINBLOCKSIZE
) == 0);
538 ASSERT(!vd
|| spa_config_held(spa
, SCL_STATE_ALL
, RW_READER
));
539 ASSERT(!bp
|| !(flags
& ZIO_FLAG_CONFIG_WRITER
));
540 ASSERT(vd
|| stage
== ZIO_STAGE_OPEN
);
542 zio
= kmem_cache_alloc(zio_cache
, KM_PUSHPAGE
);
545 zio
->io_child_type
= ZIO_CHILD_VDEV
;
546 else if (flags
& ZIO_FLAG_GANG_CHILD
)
547 zio
->io_child_type
= ZIO_CHILD_GANG
;
548 else if (flags
& ZIO_FLAG_DDT_CHILD
)
549 zio
->io_child_type
= ZIO_CHILD_DDT
;
551 zio
->io_child_type
= ZIO_CHILD_LOGICAL
;
554 zio
->io_logical
= NULL
;
555 zio
->io_bp
= (blkptr_t
*)bp
;
556 zio
->io_bp_copy
= *bp
;
557 zio
->io_bp_orig
= *bp
;
558 if (type
!= ZIO_TYPE_WRITE
||
559 zio
->io_child_type
== ZIO_CHILD_DDT
)
560 zio
->io_bp
= &zio
->io_bp_copy
; /* so caller can free */
561 if (zio
->io_child_type
== ZIO_CHILD_LOGICAL
)
562 zio
->io_logical
= zio
;
563 if (zio
->io_child_type
> ZIO_CHILD_GANG
&& BP_IS_GANG(bp
))
564 pipeline
|= ZIO_GANG_STAGES
;
566 zio
->io_logical
= NULL
;
568 bzero(&zio
->io_bp_copy
, sizeof (blkptr_t
));
569 bzero(&zio
->io_bp_orig
, sizeof (blkptr_t
));
574 zio
->io_ready
= NULL
;
576 zio
->io_private
= private;
577 zio
->io_prev_space_delta
= 0;
579 zio
->io_priority
= priority
;
582 zio
->io_vsd_ops
= NULL
;
583 zio
->io_offset
= offset
;
584 zio
->io_deadline
= 0;
585 zio
->io_orig_data
= zio
->io_data
= data
;
586 zio
->io_orig_size
= zio
->io_size
= size
;
587 zio
->io_orig_flags
= zio
->io_flags
= flags
;
588 zio
->io_orig_stage
= zio
->io_stage
= stage
;
589 zio
->io_orig_pipeline
= zio
->io_pipeline
= pipeline
;
590 bzero(&zio
->io_prop
, sizeof (zio_prop_t
));
592 zio
->io_reexecute
= 0;
593 zio
->io_bp_override
= NULL
;
594 zio
->io_walk_link
= NULL
;
595 zio
->io_transform_stack
= NULL
;
598 zio
->io_child_count
= 0;
599 zio
->io_parent_count
= 0;
600 zio
->io_stall
= NULL
;
601 zio
->io_gang_leader
= NULL
;
602 zio
->io_gang_tree
= NULL
;
603 zio
->io_executor
= NULL
;
604 zio
->io_waiter
= NULL
;
605 zio
->io_cksum_report
= NULL
;
607 bzero(zio
->io_child_error
, sizeof (int) * ZIO_CHILD_TYPES
);
608 bzero(zio
->io_children
,
609 sizeof (uint64_t) * ZIO_CHILD_TYPES
* ZIO_WAIT_TYPES
);
610 bzero(&zio
->io_bookmark
, sizeof (zbookmark_t
));
612 zio
->io_state
[ZIO_WAIT_READY
] = (stage
>= ZIO_STAGE_READY
);
613 zio
->io_state
[ZIO_WAIT_DONE
] = (stage
>= ZIO_STAGE_DONE
);
616 zio
->io_bookmark
= *zb
;
619 if (zio
->io_logical
== NULL
)
620 zio
->io_logical
= pio
->io_logical
;
621 if (zio
->io_child_type
== ZIO_CHILD_GANG
)
622 zio
->io_gang_leader
= pio
->io_gang_leader
;
623 zio_add_child(pio
, zio
);
626 taskq_init_ent(&zio
->io_tqent
);
632 zio_destroy(zio_t
*zio
)
634 kmem_cache_free(zio_cache
, zio
);
638 zio_null(zio_t
*pio
, spa_t
*spa
, vdev_t
*vd
, zio_done_func_t
*done
,
639 void *private, enum zio_flag flags
)
643 zio
= zio_create(pio
, spa
, 0, NULL
, NULL
, 0, done
, private,
644 ZIO_TYPE_NULL
, ZIO_PRIORITY_NOW
, flags
, vd
, 0, NULL
,
645 ZIO_STAGE_OPEN
, ZIO_INTERLOCK_PIPELINE
);
651 zio_root(spa_t
*spa
, zio_done_func_t
*done
, void *private, enum zio_flag flags
)
653 return (zio_null(NULL
, spa
, NULL
, done
, private, flags
));
657 zio_read(zio_t
*pio
, spa_t
*spa
, const blkptr_t
*bp
,
658 void *data
, uint64_t size
, zio_done_func_t
*done
, void *private,
659 int priority
, enum zio_flag flags
, const zbookmark_t
*zb
)
663 zio
= zio_create(pio
, spa
, BP_PHYSICAL_BIRTH(bp
), bp
,
664 data
, size
, done
, private,
665 ZIO_TYPE_READ
, priority
, flags
, NULL
, 0, zb
,
666 ZIO_STAGE_OPEN
, (flags
& ZIO_FLAG_DDT_CHILD
) ?
667 ZIO_DDT_CHILD_READ_PIPELINE
: ZIO_READ_PIPELINE
);
673 zio_write(zio_t
*pio
, spa_t
*spa
, uint64_t txg
, blkptr_t
*bp
,
674 void *data
, uint64_t size
, const zio_prop_t
*zp
,
675 zio_done_func_t
*ready
, zio_done_func_t
*done
, void *private,
676 int priority
, enum zio_flag flags
, const zbookmark_t
*zb
)
680 ASSERT(zp
->zp_checksum
>= ZIO_CHECKSUM_OFF
&&
681 zp
->zp_checksum
< ZIO_CHECKSUM_FUNCTIONS
&&
682 zp
->zp_compress
>= ZIO_COMPRESS_OFF
&&
683 zp
->zp_compress
< ZIO_COMPRESS_FUNCTIONS
&&
684 zp
->zp_type
< DMU_OT_NUMTYPES
&&
687 zp
->zp_copies
<= spa_max_replication(spa
) &&
689 zp
->zp_dedup_verify
<= 1);
691 zio
= zio_create(pio
, spa
, txg
, bp
, data
, size
, done
, private,
692 ZIO_TYPE_WRITE
, priority
, flags
, NULL
, 0, zb
,
693 ZIO_STAGE_OPEN
, (flags
& ZIO_FLAG_DDT_CHILD
) ?
694 ZIO_DDT_CHILD_WRITE_PIPELINE
: ZIO_WRITE_PIPELINE
);
696 zio
->io_ready
= ready
;
703 zio_rewrite(zio_t
*pio
, spa_t
*spa
, uint64_t txg
, blkptr_t
*bp
, void *data
,
704 uint64_t size
, zio_done_func_t
*done
, void *private, int priority
,
705 enum zio_flag flags
, zbookmark_t
*zb
)
709 zio
= zio_create(pio
, spa
, txg
, bp
, data
, size
, done
, private,
710 ZIO_TYPE_WRITE
, priority
, flags
, NULL
, 0, zb
,
711 ZIO_STAGE_OPEN
, ZIO_REWRITE_PIPELINE
);
717 zio_write_override(zio_t
*zio
, blkptr_t
*bp
, int copies
)
719 ASSERT(zio
->io_type
== ZIO_TYPE_WRITE
);
720 ASSERT(zio
->io_child_type
== ZIO_CHILD_LOGICAL
);
721 ASSERT(zio
->io_stage
== ZIO_STAGE_OPEN
);
722 ASSERT(zio
->io_txg
== spa_syncing_txg(zio
->io_spa
));
724 zio
->io_prop
.zp_copies
= copies
;
725 zio
->io_bp_override
= bp
;
729 zio_free(spa_t
*spa
, uint64_t txg
, const blkptr_t
*bp
)
731 bplist_append(&spa
->spa_free_bplist
[txg
& TXG_MASK
], bp
);
735 zio_free_sync(zio_t
*pio
, spa_t
*spa
, uint64_t txg
, const blkptr_t
*bp
,
740 dprintf_bp(bp
, "freeing in txg %llu, pass %u",
741 (longlong_t
)txg
, spa
->spa_sync_pass
);
743 ASSERT(!BP_IS_HOLE(bp
));
744 ASSERT(spa_syncing_txg(spa
) == txg
);
745 ASSERT(spa_sync_pass(spa
) <= SYNC_PASS_DEFERRED_FREE
);
747 zio
= zio_create(pio
, spa
, txg
, bp
, NULL
, BP_GET_PSIZE(bp
),
748 NULL
, NULL
, ZIO_TYPE_FREE
, ZIO_PRIORITY_FREE
, flags
,
749 NULL
, 0, NULL
, ZIO_STAGE_OPEN
, ZIO_FREE_PIPELINE
);
755 zio_claim(zio_t
*pio
, spa_t
*spa
, uint64_t txg
, const blkptr_t
*bp
,
756 zio_done_func_t
*done
, void *private, enum zio_flag flags
)
761 * A claim is an allocation of a specific block. Claims are needed
762 * to support immediate writes in the intent log. The issue is that
763 * immediate writes contain committed data, but in a txg that was
764 * *not* committed. Upon opening the pool after an unclean shutdown,
765 * the intent log claims all blocks that contain immediate write data
766 * so that the SPA knows they're in use.
768 * All claims *must* be resolved in the first txg -- before the SPA
769 * starts allocating blocks -- so that nothing is allocated twice.
770 * If txg == 0 we just verify that the block is claimable.
772 ASSERT3U(spa
->spa_uberblock
.ub_rootbp
.blk_birth
, <, spa_first_txg(spa
));
773 ASSERT(txg
== spa_first_txg(spa
) || txg
== 0);
774 ASSERT(!BP_GET_DEDUP(bp
) || !spa_writeable(spa
)); /* zdb(1M) */
776 zio
= zio_create(pio
, spa
, txg
, bp
, NULL
, BP_GET_PSIZE(bp
),
777 done
, private, ZIO_TYPE_CLAIM
, ZIO_PRIORITY_NOW
, flags
,
778 NULL
, 0, NULL
, ZIO_STAGE_OPEN
, ZIO_CLAIM_PIPELINE
);
784 zio_ioctl(zio_t
*pio
, spa_t
*spa
, vdev_t
*vd
, int cmd
,
785 zio_done_func_t
*done
, void *private, int priority
, enum zio_flag flags
)
790 if (vd
->vdev_children
== 0) {
791 zio
= zio_create(pio
, spa
, 0, NULL
, NULL
, 0, done
, private,
792 ZIO_TYPE_IOCTL
, priority
, flags
, vd
, 0, NULL
,
793 ZIO_STAGE_OPEN
, ZIO_IOCTL_PIPELINE
);
797 zio
= zio_null(pio
, spa
, NULL
, NULL
, NULL
, flags
);
799 for (c
= 0; c
< vd
->vdev_children
; c
++)
800 zio_nowait(zio_ioctl(zio
, spa
, vd
->vdev_child
[c
], cmd
,
801 done
, private, priority
, flags
));
808 zio_read_phys(zio_t
*pio
, vdev_t
*vd
, uint64_t offset
, uint64_t size
,
809 void *data
, int checksum
, zio_done_func_t
*done
, void *private,
810 int priority
, enum zio_flag flags
, boolean_t labels
)
814 ASSERT(vd
->vdev_children
== 0);
815 ASSERT(!labels
|| offset
+ size
<= VDEV_LABEL_START_SIZE
||
816 offset
>= vd
->vdev_psize
- VDEV_LABEL_END_SIZE
);
817 ASSERT3U(offset
+ size
, <=, vd
->vdev_psize
);
819 zio
= zio_create(pio
, vd
->vdev_spa
, 0, NULL
, data
, size
, done
, private,
820 ZIO_TYPE_READ
, priority
, flags
, vd
, offset
, NULL
,
821 ZIO_STAGE_OPEN
, ZIO_READ_PHYS_PIPELINE
);
823 zio
->io_prop
.zp_checksum
= checksum
;
829 zio_write_phys(zio_t
*pio
, vdev_t
*vd
, uint64_t offset
, uint64_t size
,
830 void *data
, int checksum
, zio_done_func_t
*done
, void *private,
831 int priority
, enum zio_flag flags
, boolean_t labels
)
835 ASSERT(vd
->vdev_children
== 0);
836 ASSERT(!labels
|| offset
+ size
<= VDEV_LABEL_START_SIZE
||
837 offset
>= vd
->vdev_psize
- VDEV_LABEL_END_SIZE
);
838 ASSERT3U(offset
+ size
, <=, vd
->vdev_psize
);
840 zio
= zio_create(pio
, vd
->vdev_spa
, 0, NULL
, data
, size
, done
, private,
841 ZIO_TYPE_WRITE
, priority
, flags
, vd
, offset
, NULL
,
842 ZIO_STAGE_OPEN
, ZIO_WRITE_PHYS_PIPELINE
);
844 zio
->io_prop
.zp_checksum
= checksum
;
846 if (zio_checksum_table
[checksum
].ci_eck
) {
848 * zec checksums are necessarily destructive -- they modify
849 * the end of the write buffer to hold the verifier/checksum.
850 * Therefore, we must make a local copy in case the data is
851 * being written to multiple places in parallel.
853 void *wbuf
= zio_buf_alloc(size
);
854 bcopy(data
, wbuf
, size
);
855 zio_push_transform(zio
, wbuf
, size
, size
, NULL
);
862 * Create a child I/O to do some work for us.
865 zio_vdev_child_io(zio_t
*pio
, blkptr_t
*bp
, vdev_t
*vd
, uint64_t offset
,
866 void *data
, uint64_t size
, int type
, int priority
, enum zio_flag flags
,
867 zio_done_func_t
*done
, void *private)
869 enum zio_stage pipeline
= ZIO_VDEV_CHILD_PIPELINE
;
872 ASSERT(vd
->vdev_parent
==
873 (pio
->io_vd
? pio
->io_vd
: pio
->io_spa
->spa_root_vdev
));
875 if (type
== ZIO_TYPE_READ
&& bp
!= NULL
) {
877 * If we have the bp, then the child should perform the
878 * checksum and the parent need not. This pushes error
879 * detection as close to the leaves as possible and
880 * eliminates redundant checksums in the interior nodes.
882 pipeline
|= ZIO_STAGE_CHECKSUM_VERIFY
;
883 pio
->io_pipeline
&= ~ZIO_STAGE_CHECKSUM_VERIFY
;
886 if (vd
->vdev_children
== 0)
887 offset
+= VDEV_LABEL_START_SIZE
;
889 flags
|= ZIO_VDEV_CHILD_FLAGS(pio
) | ZIO_FLAG_DONT_PROPAGATE
;
892 * If we've decided to do a repair, the write is not speculative --
893 * even if the original read was.
895 if (flags
& ZIO_FLAG_IO_REPAIR
)
896 flags
&= ~ZIO_FLAG_SPECULATIVE
;
898 zio
= zio_create(pio
, pio
->io_spa
, pio
->io_txg
, bp
, data
, size
,
899 done
, private, type
, priority
, flags
, vd
, offset
, &pio
->io_bookmark
,
900 ZIO_STAGE_VDEV_IO_START
>> 1, pipeline
);
906 zio_vdev_delegated_io(vdev_t
*vd
, uint64_t offset
, void *data
, uint64_t size
,
907 int type
, int priority
, enum zio_flag flags
,
908 zio_done_func_t
*done
, void *private)
912 ASSERT(vd
->vdev_ops
->vdev_op_leaf
);
914 zio
= zio_create(NULL
, vd
->vdev_spa
, 0, NULL
,
915 data
, size
, done
, private, type
, priority
,
916 flags
| ZIO_FLAG_CANFAIL
| ZIO_FLAG_DONT_RETRY
,
918 ZIO_STAGE_VDEV_IO_START
>> 1, ZIO_VDEV_CHILD_PIPELINE
);
924 zio_flush(zio_t
*zio
, vdev_t
*vd
)
926 zio_nowait(zio_ioctl(zio
, zio
->io_spa
, vd
, DKIOCFLUSHWRITECACHE
,
927 NULL
, NULL
, ZIO_PRIORITY_NOW
,
928 ZIO_FLAG_CANFAIL
| ZIO_FLAG_DONT_PROPAGATE
| ZIO_FLAG_DONT_RETRY
));
932 zio_shrink(zio_t
*zio
, uint64_t size
)
934 ASSERT(zio
->io_executor
== NULL
);
935 ASSERT(zio
->io_orig_size
== zio
->io_size
);
936 ASSERT(size
<= zio
->io_size
);
939 * We don't shrink for raidz because of problems with the
940 * reconstruction when reading back less than the block size.
941 * Note, BP_IS_RAIDZ() assumes no compression.
943 ASSERT(BP_GET_COMPRESS(zio
->io_bp
) == ZIO_COMPRESS_OFF
);
944 if (!BP_IS_RAIDZ(zio
->io_bp
))
945 zio
->io_orig_size
= zio
->io_size
= size
;
949 * ==========================================================================
950 * Prepare to read and write logical blocks
951 * ==========================================================================
955 zio_read_bp_init(zio_t
*zio
)
957 blkptr_t
*bp
= zio
->io_bp
;
959 if (BP_GET_COMPRESS(bp
) != ZIO_COMPRESS_OFF
&&
960 zio
->io_child_type
== ZIO_CHILD_LOGICAL
&&
961 !(zio
->io_flags
& ZIO_FLAG_RAW
)) {
962 uint64_t psize
= BP_GET_PSIZE(bp
);
963 void *cbuf
= zio_buf_alloc(psize
);
965 zio_push_transform(zio
, cbuf
, psize
, psize
, zio_decompress
);
968 if (!dmu_ot
[BP_GET_TYPE(bp
)].ot_metadata
&& BP_GET_LEVEL(bp
) == 0)
969 zio
->io_flags
|= ZIO_FLAG_DONT_CACHE
;
971 if (BP_GET_TYPE(bp
) == DMU_OT_DDT_ZAP
)
972 zio
->io_flags
|= ZIO_FLAG_DONT_CACHE
;
974 if (BP_GET_DEDUP(bp
) && zio
->io_child_type
== ZIO_CHILD_LOGICAL
)
975 zio
->io_pipeline
= ZIO_DDT_READ_PIPELINE
;
977 return (ZIO_PIPELINE_CONTINUE
);
981 zio_write_bp_init(zio_t
*zio
)
983 spa_t
*spa
= zio
->io_spa
;
984 zio_prop_t
*zp
= &zio
->io_prop
;
985 enum zio_compress compress
= zp
->zp_compress
;
986 blkptr_t
*bp
= zio
->io_bp
;
987 uint64_t lsize
= zio
->io_size
;
988 uint64_t psize
= lsize
;
992 * If our children haven't all reached the ready stage,
993 * wait for them and then repeat this pipeline stage.
995 if (zio_wait_for_children(zio
, ZIO_CHILD_GANG
, ZIO_WAIT_READY
) ||
996 zio_wait_for_children(zio
, ZIO_CHILD_LOGICAL
, ZIO_WAIT_READY
))
997 return (ZIO_PIPELINE_STOP
);
999 if (!IO_IS_ALLOCATING(zio
))
1000 return (ZIO_PIPELINE_CONTINUE
);
1002 ASSERT(zio
->io_child_type
!= ZIO_CHILD_DDT
);
1004 if (zio
->io_bp_override
) {
1005 ASSERT(bp
->blk_birth
!= zio
->io_txg
);
1006 ASSERT(BP_GET_DEDUP(zio
->io_bp_override
) == 0);
1008 *bp
= *zio
->io_bp_override
;
1009 zio
->io_pipeline
= ZIO_INTERLOCK_PIPELINE
;
1011 if (BP_IS_HOLE(bp
) || !zp
->zp_dedup
)
1012 return (ZIO_PIPELINE_CONTINUE
);
1014 ASSERT(zio_checksum_table
[zp
->zp_checksum
].ci_dedup
||
1015 zp
->zp_dedup_verify
);
1017 if (BP_GET_CHECKSUM(bp
) == zp
->zp_checksum
) {
1018 BP_SET_DEDUP(bp
, 1);
1019 zio
->io_pipeline
|= ZIO_STAGE_DDT_WRITE
;
1020 return (ZIO_PIPELINE_CONTINUE
);
1022 zio
->io_bp_override
= NULL
;
1026 if (bp
->blk_birth
== zio
->io_txg
) {
1028 * We're rewriting an existing block, which means we're
1029 * working on behalf of spa_sync(). For spa_sync() to
1030 * converge, it must eventually be the case that we don't
1031 * have to allocate new blocks. But compression changes
1032 * the blocksize, which forces a reallocate, and makes
1033 * convergence take longer. Therefore, after the first
1034 * few passes, stop compressing to ensure convergence.
1036 pass
= spa_sync_pass(spa
);
1038 ASSERT(zio
->io_txg
== spa_syncing_txg(spa
));
1039 ASSERT(zio
->io_child_type
== ZIO_CHILD_LOGICAL
);
1040 ASSERT(!BP_GET_DEDUP(bp
));
1042 if (pass
> SYNC_PASS_DONT_COMPRESS
)
1043 compress
= ZIO_COMPRESS_OFF
;
1045 /* Make sure someone doesn't change their mind on overwrites */
1046 ASSERT(MIN(zp
->zp_copies
+ BP_IS_GANG(bp
),
1047 spa_max_replication(spa
)) == BP_GET_NDVAS(bp
));
1050 if (compress
!= ZIO_COMPRESS_OFF
) {
1051 void *cbuf
= zio_buf_alloc(lsize
);
1052 psize
= zio_compress_data(compress
, zio
->io_data
, cbuf
, lsize
);
1053 if (psize
== 0 || psize
== lsize
) {
1054 compress
= ZIO_COMPRESS_OFF
;
1055 zio_buf_free(cbuf
, lsize
);
1057 ASSERT(psize
< lsize
);
1058 zio_push_transform(zio
, cbuf
, psize
, lsize
, NULL
);
1063 * The final pass of spa_sync() must be all rewrites, but the first
1064 * few passes offer a trade-off: allocating blocks defers convergence,
1065 * but newly allocated blocks are sequential, so they can be written
1066 * to disk faster. Therefore, we allow the first few passes of
1067 * spa_sync() to allocate new blocks, but force rewrites after that.
1068 * There should only be a handful of blocks after pass 1 in any case.
1070 if (bp
->blk_birth
== zio
->io_txg
&& BP_GET_PSIZE(bp
) == psize
&&
1071 pass
> SYNC_PASS_REWRITE
) {
1072 enum zio_stage gang_stages
= zio
->io_pipeline
& ZIO_GANG_STAGES
;
1074 zio
->io_pipeline
= ZIO_REWRITE_PIPELINE
| gang_stages
;
1075 zio
->io_flags
|= ZIO_FLAG_IO_REWRITE
;
1078 zio
->io_pipeline
= ZIO_WRITE_PIPELINE
;
1082 zio
->io_pipeline
= ZIO_INTERLOCK_PIPELINE
;
1084 ASSERT(zp
->zp_checksum
!= ZIO_CHECKSUM_GANG_HEADER
);
1085 BP_SET_LSIZE(bp
, lsize
);
1086 BP_SET_PSIZE(bp
, psize
);
1087 BP_SET_COMPRESS(bp
, compress
);
1088 BP_SET_CHECKSUM(bp
, zp
->zp_checksum
);
1089 BP_SET_TYPE(bp
, zp
->zp_type
);
1090 BP_SET_LEVEL(bp
, zp
->zp_level
);
1091 BP_SET_DEDUP(bp
, zp
->zp_dedup
);
1092 BP_SET_BYTEORDER(bp
, ZFS_HOST_BYTEORDER
);
1094 ASSERT(zio
->io_child_type
== ZIO_CHILD_LOGICAL
);
1095 ASSERT(!(zio
->io_flags
& ZIO_FLAG_IO_REWRITE
));
1096 zio
->io_pipeline
= ZIO_DDT_WRITE_PIPELINE
;
1100 return (ZIO_PIPELINE_CONTINUE
);
1104 zio_free_bp_init(zio_t
*zio
)
1106 blkptr_t
*bp
= zio
->io_bp
;
1108 if (zio
->io_child_type
== ZIO_CHILD_LOGICAL
) {
1109 if (BP_GET_DEDUP(bp
))
1110 zio
->io_pipeline
= ZIO_DDT_FREE_PIPELINE
;
1113 return (ZIO_PIPELINE_CONTINUE
);
1117 * ==========================================================================
1118 * Execute the I/O pipeline
1119 * ==========================================================================
1123 zio_taskq_dispatch(zio_t
*zio
, enum zio_taskq_type q
, boolean_t cutinline
)
1125 spa_t
*spa
= zio
->io_spa
;
1126 zio_type_t t
= zio
->io_type
;
1127 int flags
= (cutinline
? TQ_FRONT
: 0);
1130 * If we're a config writer or a probe, the normal issue and
1131 * interrupt threads may all be blocked waiting for the config lock.
1132 * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL.
1134 if (zio
->io_flags
& (ZIO_FLAG_CONFIG_WRITER
| ZIO_FLAG_PROBE
))
1138 * A similar issue exists for the L2ARC write thread until L2ARC 2.0.
1140 if (t
== ZIO_TYPE_WRITE
&& zio
->io_vd
&& zio
->io_vd
->vdev_aux
)
1144 * If this is a high priority I/O, then use the high priority taskq.
1146 if (zio
->io_priority
== ZIO_PRIORITY_NOW
&&
1147 spa
->spa_zio_taskq
[t
][q
+ 1] != NULL
)
1150 ASSERT3U(q
, <, ZIO_TASKQ_TYPES
);
1153 * NB: We are assuming that the zio can only be dispatched
1154 * to a single taskq at a time. It would be a grievous error
1155 * to dispatch the zio to another taskq at the same time.
1157 ASSERT(taskq_empty_ent(&zio
->io_tqent
));
1158 taskq_dispatch_ent(spa
->spa_zio_taskq
[t
][q
],
1159 (task_func_t
*)zio_execute
, zio
, flags
, &zio
->io_tqent
);
1163 zio_taskq_member(zio_t
*zio
, enum zio_taskq_type q
)
1165 kthread_t
*executor
= zio
->io_executor
;
1166 spa_t
*spa
= zio
->io_spa
;
1169 for (t
= 0; t
< ZIO_TYPES
; t
++)
1170 if (taskq_member(spa
->spa_zio_taskq
[t
][q
], executor
))
1177 zio_issue_async(zio_t
*zio
)
1179 zio_taskq_dispatch(zio
, ZIO_TASKQ_ISSUE
, B_FALSE
);
1181 return (ZIO_PIPELINE_STOP
);
1185 zio_interrupt(zio_t
*zio
)
1187 zio_taskq_dispatch(zio
, ZIO_TASKQ_INTERRUPT
, B_FALSE
);
1191 * Execute the I/O pipeline until one of the following occurs:
1192 * (1) the I/O completes; (2) the pipeline stalls waiting for
1193 * dependent child I/Os; (3) the I/O issues, so we're waiting
1194 * for an I/O completion interrupt; (4) the I/O is delegated by
1195 * vdev-level caching or aggregation; (5) the I/O is deferred
1196 * due to vdev-level queueing; (6) the I/O is handed off to
1197 * another thread. In all cases, the pipeline stops whenever
1198 * there's no CPU work; it never burns a thread in cv_wait().
1200 * There's no locking on io_stage because there's no legitimate way
1201 * for multiple threads to be attempting to process the same I/O.
1203 static zio_pipe_stage_t
*zio_pipeline
[];
1206 * zio_execute() is a wrapper around the static function
1207 * __zio_execute() so that we can force __zio_execute() to be
1208 * inlined. This reduces stack overhead which is important
1209 * because __zio_execute() is called recursively in several zio
1210 * code paths. zio_execute() itself cannot be inlined because
1211 * it is externally visible.
1214 zio_execute(zio_t
*zio
)
1219 __attribute__((always_inline
))
1221 __zio_execute(zio_t
*zio
)
1223 zio
->io_executor
= curthread
;
1225 while (zio
->io_stage
< ZIO_STAGE_DONE
) {
1226 enum zio_stage pipeline
= zio
->io_pipeline
;
1227 enum zio_stage stage
= zio
->io_stage
;
1232 ASSERT(!MUTEX_HELD(&zio
->io_lock
));
1233 ASSERT(ISP2(stage
));
1234 ASSERT(zio
->io_stall
== NULL
);
1238 } while ((stage
& pipeline
) == 0);
1240 ASSERT(stage
<= ZIO_STAGE_DONE
);
1242 dsl
= spa_get_dsl(zio
->io_spa
);
1243 cut
= (stage
== ZIO_STAGE_VDEV_IO_START
) ?
1244 zio_requeue_io_start_cut_in_line
: B_FALSE
;
1247 * If we are in interrupt context and this pipeline stage
1248 * will grab a config lock that is held across I/O,
1249 * or may wait for an I/O that needs an interrupt thread
1250 * to complete, issue async to avoid deadlock.
1252 * If we are in the txg_sync_thread or being called
1253 * during pool init issue async to minimize stack depth.
1254 * Both of these call paths may be recursively called.
1256 * For VDEV_IO_START, we cut in line so that the io will
1257 * be sent to disk promptly.
1259 if (((stage
& ZIO_BLOCKING_STAGES
) && zio
->io_vd
== NULL
&&
1260 zio_taskq_member(zio
, ZIO_TASKQ_INTERRUPT
)) ||
1261 (dsl
!= NULL
&& dsl_pool_sync_context(dsl
))) {
1262 zio_taskq_dispatch(zio
, ZIO_TASKQ_ISSUE
, cut
);
1266 zio
->io_stage
= stage
;
1267 rv
= zio_pipeline
[highbit(stage
) - 1](zio
);
1269 if (rv
== ZIO_PIPELINE_STOP
)
1272 ASSERT(rv
== ZIO_PIPELINE_CONTINUE
);
1278 * ==========================================================================
1279 * Initiate I/O, either sync or async
1280 * ==========================================================================
1283 zio_wait(zio_t
*zio
)
1287 ASSERT(zio
->io_stage
== ZIO_STAGE_OPEN
);
1288 ASSERT(zio
->io_executor
== NULL
);
1290 zio
->io_waiter
= curthread
;
1294 mutex_enter(&zio
->io_lock
);
1295 while (zio
->io_executor
!= NULL
)
1296 cv_wait(&zio
->io_cv
, &zio
->io_lock
);
1297 mutex_exit(&zio
->io_lock
);
1299 error
= zio
->io_error
;
1306 zio_nowait(zio_t
*zio
)
1308 ASSERT(zio
->io_executor
== NULL
);
1310 if (zio
->io_child_type
== ZIO_CHILD_LOGICAL
&&
1311 zio_unique_parent(zio
) == NULL
) {
1313 * This is a logical async I/O with no parent to wait for it.
1314 * We add it to the spa_async_root_zio "Godfather" I/O which
1315 * will ensure they complete prior to unloading the pool.
1317 spa_t
*spa
= zio
->io_spa
;
1319 zio_add_child(spa
->spa_async_zio_root
, zio
);
1326 * ==========================================================================
1327 * Reexecute or suspend/resume failed I/O
1328 * ==========================================================================
1332 zio_reexecute(zio_t
*pio
)
1334 zio_t
*cio
, *cio_next
;
1337 ASSERT(pio
->io_child_type
== ZIO_CHILD_LOGICAL
);
1338 ASSERT(pio
->io_orig_stage
== ZIO_STAGE_OPEN
);
1339 ASSERT(pio
->io_gang_leader
== NULL
);
1340 ASSERT(pio
->io_gang_tree
== NULL
);
1342 pio
->io_flags
= pio
->io_orig_flags
;
1343 pio
->io_stage
= pio
->io_orig_stage
;
1344 pio
->io_pipeline
= pio
->io_orig_pipeline
;
1345 pio
->io_reexecute
= 0;
1347 for (w
= 0; w
< ZIO_WAIT_TYPES
; w
++)
1348 pio
->io_state
[w
] = 0;
1349 for (c
= 0; c
< ZIO_CHILD_TYPES
; c
++)
1350 pio
->io_child_error
[c
] = 0;
1352 if (IO_IS_ALLOCATING(pio
))
1353 BP_ZERO(pio
->io_bp
);
1356 * As we reexecute pio's children, new children could be created.
1357 * New children go to the head of pio's io_child_list, however,
1358 * so we will (correctly) not reexecute them. The key is that
1359 * the remainder of pio's io_child_list, from 'cio_next' onward,
1360 * cannot be affected by any side effects of reexecuting 'cio'.
1362 for (cio
= zio_walk_children(pio
); cio
!= NULL
; cio
= cio_next
) {
1363 cio_next
= zio_walk_children(pio
);
1364 mutex_enter(&pio
->io_lock
);
1365 for (w
= 0; w
< ZIO_WAIT_TYPES
; w
++)
1366 pio
->io_children
[cio
->io_child_type
][w
]++;
1367 mutex_exit(&pio
->io_lock
);
1372 * Now that all children have been reexecuted, execute the parent.
1373 * We don't reexecute "The Godfather" I/O here as it's the
1374 * responsibility of the caller to wait on him.
1376 if (!(pio
->io_flags
& ZIO_FLAG_GODFATHER
))
1381 zio_suspend(spa_t
*spa
, zio_t
*zio
)
1383 if (spa_get_failmode(spa
) == ZIO_FAILURE_MODE_PANIC
)
1384 fm_panic("Pool '%s' has encountered an uncorrectable I/O "
1385 "failure and the failure mode property for this pool "
1386 "is set to panic.", spa_name(spa
));
1388 zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE
, spa
, NULL
, NULL
, 0, 0);
1390 mutex_enter(&spa
->spa_suspend_lock
);
1392 if (spa
->spa_suspend_zio_root
== NULL
)
1393 spa
->spa_suspend_zio_root
= zio_root(spa
, NULL
, NULL
,
1394 ZIO_FLAG_CANFAIL
| ZIO_FLAG_SPECULATIVE
|
1395 ZIO_FLAG_GODFATHER
);
1397 spa
->spa_suspended
= B_TRUE
;
1400 ASSERT(!(zio
->io_flags
& ZIO_FLAG_GODFATHER
));
1401 ASSERT(zio
!= spa
->spa_suspend_zio_root
);
1402 ASSERT(zio
->io_child_type
== ZIO_CHILD_LOGICAL
);
1403 ASSERT(zio_unique_parent(zio
) == NULL
);
1404 ASSERT(zio
->io_stage
== ZIO_STAGE_DONE
);
1405 zio_add_child(spa
->spa_suspend_zio_root
, zio
);
1408 mutex_exit(&spa
->spa_suspend_lock
);
1412 zio_resume(spa_t
*spa
)
1417 * Reexecute all previously suspended i/o.
1419 mutex_enter(&spa
->spa_suspend_lock
);
1420 spa
->spa_suspended
= B_FALSE
;
1421 cv_broadcast(&spa
->spa_suspend_cv
);
1422 pio
= spa
->spa_suspend_zio_root
;
1423 spa
->spa_suspend_zio_root
= NULL
;
1424 mutex_exit(&spa
->spa_suspend_lock
);
1430 return (zio_wait(pio
));
1434 zio_resume_wait(spa_t
*spa
)
1436 mutex_enter(&spa
->spa_suspend_lock
);
1437 while (spa_suspended(spa
))
1438 cv_wait(&spa
->spa_suspend_cv
, &spa
->spa_suspend_lock
);
1439 mutex_exit(&spa
->spa_suspend_lock
);
1443 * ==========================================================================
1446 * A gang block is a collection of small blocks that looks to the DMU
1447 * like one large block. When zio_dva_allocate() cannot find a block
1448 * of the requested size, due to either severe fragmentation or the pool
1449 * being nearly full, it calls zio_write_gang_block() to construct the
1450 * block from smaller fragments.
1452 * A gang block consists of a gang header (zio_gbh_phys_t) and up to
1453 * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like
1454 * an indirect block: it's an array of block pointers. It consumes
1455 * only one sector and hence is allocatable regardless of fragmentation.
1456 * The gang header's bps point to its gang members, which hold the data.
1458 * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg>
1459 * as the verifier to ensure uniqueness of the SHA256 checksum.
1460 * Critically, the gang block bp's blk_cksum is the checksum of the data,
1461 * not the gang header. This ensures that data block signatures (needed for
1462 * deduplication) are independent of how the block is physically stored.
1464 * Gang blocks can be nested: a gang member may itself be a gang block.
1465 * Thus every gang block is a tree in which root and all interior nodes are
1466 * gang headers, and the leaves are normal blocks that contain user data.
1467 * The root of the gang tree is called the gang leader.
1469 * To perform any operation (read, rewrite, free, claim) on a gang block,
1470 * zio_gang_assemble() first assembles the gang tree (minus data leaves)
1471 * in the io_gang_tree field of the original logical i/o by recursively
1472 * reading the gang leader and all gang headers below it. This yields
1473 * an in-core tree containing the contents of every gang header and the
1474 * bps for every constituent of the gang block.
1476 * With the gang tree now assembled, zio_gang_issue() just walks the gang tree
1477 * and invokes a callback on each bp. To free a gang block, zio_gang_issue()
1478 * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp.
1479 * zio_claim_gang() provides a similarly trivial wrapper for zio_claim().
1480 * zio_read_gang() is a wrapper around zio_read() that omits reading gang
1481 * headers, since we already have those in io_gang_tree. zio_rewrite_gang()
1482 * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite()
1483 * of the gang header plus zio_checksum_compute() of the data to update the
1484 * gang header's blk_cksum as described above.
1486 * The two-phase assemble/issue model solves the problem of partial failure --
1487 * what if you'd freed part of a gang block but then couldn't read the
1488 * gang header for another part? Assembling the entire gang tree first
1489 * ensures that all the necessary gang header I/O has succeeded before
1490 * starting the actual work of free, claim, or write. Once the gang tree
1491 * is assembled, free and claim are in-memory operations that cannot fail.
1493 * In the event that a gang write fails, zio_dva_unallocate() walks the
1494 * gang tree to immediately free (i.e. insert back into the space map)
1495 * everything we've allocated. This ensures that we don't get ENOSPC
1496 * errors during repeated suspend/resume cycles due to a flaky device.
1498 * Gang rewrites only happen during sync-to-convergence. If we can't assemble
1499 * the gang tree, we won't modify the block, so we can safely defer the free
1500 * (knowing that the block is still intact). If we *can* assemble the gang
1501 * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free
1502 * each constituent bp and we can allocate a new block on the next sync pass.
1504 * In all cases, the gang tree allows complete recovery from partial failure.
1505 * ==========================================================================
1509 zio_read_gang(zio_t
*pio
, blkptr_t
*bp
, zio_gang_node_t
*gn
, void *data
)
1514 return (zio_read(pio
, pio
->io_spa
, bp
, data
, BP_GET_PSIZE(bp
),
1515 NULL
, NULL
, pio
->io_priority
, ZIO_GANG_CHILD_FLAGS(pio
),
1516 &pio
->io_bookmark
));
1520 zio_rewrite_gang(zio_t
*pio
, blkptr_t
*bp
, zio_gang_node_t
*gn
, void *data
)
1525 zio
= zio_rewrite(pio
, pio
->io_spa
, pio
->io_txg
, bp
,
1526 gn
->gn_gbh
, SPA_GANGBLOCKSIZE
, NULL
, NULL
, pio
->io_priority
,
1527 ZIO_GANG_CHILD_FLAGS(pio
), &pio
->io_bookmark
);
1529 * As we rewrite each gang header, the pipeline will compute
1530 * a new gang block header checksum for it; but no one will
1531 * compute a new data checksum, so we do that here. The one
1532 * exception is the gang leader: the pipeline already computed
1533 * its data checksum because that stage precedes gang assembly.
1534 * (Presently, nothing actually uses interior data checksums;
1535 * this is just good hygiene.)
1537 if (gn
!= pio
->io_gang_leader
->io_gang_tree
) {
1538 zio_checksum_compute(zio
, BP_GET_CHECKSUM(bp
),
1539 data
, BP_GET_PSIZE(bp
));
1542 * If we are here to damage data for testing purposes,
1543 * leave the GBH alone so that we can detect the damage.
1545 if (pio
->io_gang_leader
->io_flags
& ZIO_FLAG_INDUCE_DAMAGE
)
1546 zio
->io_pipeline
&= ~ZIO_VDEV_IO_STAGES
;
1548 zio
= zio_rewrite(pio
, pio
->io_spa
, pio
->io_txg
, bp
,
1549 data
, BP_GET_PSIZE(bp
), NULL
, NULL
, pio
->io_priority
,
1550 ZIO_GANG_CHILD_FLAGS(pio
), &pio
->io_bookmark
);
1558 zio_free_gang(zio_t
*pio
, blkptr_t
*bp
, zio_gang_node_t
*gn
, void *data
)
1560 return (zio_free_sync(pio
, pio
->io_spa
, pio
->io_txg
, bp
,
1561 ZIO_GANG_CHILD_FLAGS(pio
)));
1566 zio_claim_gang(zio_t
*pio
, blkptr_t
*bp
, zio_gang_node_t
*gn
, void *data
)
1568 return (zio_claim(pio
, pio
->io_spa
, pio
->io_txg
, bp
,
1569 NULL
, NULL
, ZIO_GANG_CHILD_FLAGS(pio
)));
1572 static zio_gang_issue_func_t
*zio_gang_issue_func
[ZIO_TYPES
] = {
1581 static void zio_gang_tree_assemble_done(zio_t
*zio
);
1583 static zio_gang_node_t
*
1584 zio_gang_node_alloc(zio_gang_node_t
**gnpp
)
1586 zio_gang_node_t
*gn
;
1588 ASSERT(*gnpp
== NULL
);
1590 gn
= kmem_zalloc(sizeof (*gn
), KM_PUSHPAGE
);
1591 gn
->gn_gbh
= zio_buf_alloc(SPA_GANGBLOCKSIZE
);
1598 zio_gang_node_free(zio_gang_node_t
**gnpp
)
1600 zio_gang_node_t
*gn
= *gnpp
;
1603 for (g
= 0; g
< SPA_GBH_NBLKPTRS
; g
++)
1604 ASSERT(gn
->gn_child
[g
] == NULL
);
1606 zio_buf_free(gn
->gn_gbh
, SPA_GANGBLOCKSIZE
);
1607 kmem_free(gn
, sizeof (*gn
));
1612 zio_gang_tree_free(zio_gang_node_t
**gnpp
)
1614 zio_gang_node_t
*gn
= *gnpp
;
1620 for (g
= 0; g
< SPA_GBH_NBLKPTRS
; g
++)
1621 zio_gang_tree_free(&gn
->gn_child
[g
]);
1623 zio_gang_node_free(gnpp
);
1627 zio_gang_tree_assemble(zio_t
*gio
, blkptr_t
*bp
, zio_gang_node_t
**gnpp
)
1629 zio_gang_node_t
*gn
= zio_gang_node_alloc(gnpp
);
1631 ASSERT(gio
->io_gang_leader
== gio
);
1632 ASSERT(BP_IS_GANG(bp
));
1634 zio_nowait(zio_read(gio
, gio
->io_spa
, bp
, gn
->gn_gbh
,
1635 SPA_GANGBLOCKSIZE
, zio_gang_tree_assemble_done
, gn
,
1636 gio
->io_priority
, ZIO_GANG_CHILD_FLAGS(gio
), &gio
->io_bookmark
));
1640 zio_gang_tree_assemble_done(zio_t
*zio
)
1642 zio_t
*gio
= zio
->io_gang_leader
;
1643 zio_gang_node_t
*gn
= zio
->io_private
;
1644 blkptr_t
*bp
= zio
->io_bp
;
1647 ASSERT(gio
== zio_unique_parent(zio
));
1648 ASSERT(zio
->io_child_count
== 0);
1653 if (BP_SHOULD_BYTESWAP(bp
))
1654 byteswap_uint64_array(zio
->io_data
, zio
->io_size
);
1656 ASSERT(zio
->io_data
== gn
->gn_gbh
);
1657 ASSERT(zio
->io_size
== SPA_GANGBLOCKSIZE
);
1658 ASSERT(gn
->gn_gbh
->zg_tail
.zec_magic
== ZEC_MAGIC
);
1660 for (g
= 0; g
< SPA_GBH_NBLKPTRS
; g
++) {
1661 blkptr_t
*gbp
= &gn
->gn_gbh
->zg_blkptr
[g
];
1662 if (!BP_IS_GANG(gbp
))
1664 zio_gang_tree_assemble(gio
, gbp
, &gn
->gn_child
[g
]);
1669 zio_gang_tree_issue(zio_t
*pio
, zio_gang_node_t
*gn
, blkptr_t
*bp
, void *data
)
1671 zio_t
*gio
= pio
->io_gang_leader
;
1675 ASSERT(BP_IS_GANG(bp
) == !!gn
);
1676 ASSERT(BP_GET_CHECKSUM(bp
) == BP_GET_CHECKSUM(gio
->io_bp
));
1677 ASSERT(BP_GET_LSIZE(bp
) == BP_GET_PSIZE(bp
) || gn
== gio
->io_gang_tree
);
1680 * If you're a gang header, your data is in gn->gn_gbh.
1681 * If you're a gang member, your data is in 'data' and gn == NULL.
1683 zio
= zio_gang_issue_func
[gio
->io_type
](pio
, bp
, gn
, data
);
1686 ASSERT(gn
->gn_gbh
->zg_tail
.zec_magic
== ZEC_MAGIC
);
1688 for (g
= 0; g
< SPA_GBH_NBLKPTRS
; g
++) {
1689 blkptr_t
*gbp
= &gn
->gn_gbh
->zg_blkptr
[g
];
1690 if (BP_IS_HOLE(gbp
))
1692 zio_gang_tree_issue(zio
, gn
->gn_child
[g
], gbp
, data
);
1693 data
= (char *)data
+ BP_GET_PSIZE(gbp
);
1697 if (gn
== gio
->io_gang_tree
)
1698 ASSERT3P((char *)gio
->io_data
+ gio
->io_size
, ==, data
);
1705 zio_gang_assemble(zio_t
*zio
)
1707 blkptr_t
*bp
= zio
->io_bp
;
1709 ASSERT(BP_IS_GANG(bp
) && zio
->io_gang_leader
== NULL
);
1710 ASSERT(zio
->io_child_type
> ZIO_CHILD_GANG
);
1712 zio
->io_gang_leader
= zio
;
1714 zio_gang_tree_assemble(zio
, bp
, &zio
->io_gang_tree
);
1716 return (ZIO_PIPELINE_CONTINUE
);
1720 zio_gang_issue(zio_t
*zio
)
1722 blkptr_t
*bp
= zio
->io_bp
;
1724 if (zio_wait_for_children(zio
, ZIO_CHILD_GANG
, ZIO_WAIT_DONE
))
1725 return (ZIO_PIPELINE_STOP
);
1727 ASSERT(BP_IS_GANG(bp
) && zio
->io_gang_leader
== zio
);
1728 ASSERT(zio
->io_child_type
> ZIO_CHILD_GANG
);
1730 if (zio
->io_child_error
[ZIO_CHILD_GANG
] == 0)
1731 zio_gang_tree_issue(zio
, zio
->io_gang_tree
, bp
, zio
->io_data
);
1733 zio_gang_tree_free(&zio
->io_gang_tree
);
1735 zio
->io_pipeline
= ZIO_INTERLOCK_PIPELINE
;
1737 return (ZIO_PIPELINE_CONTINUE
);
1741 zio_write_gang_member_ready(zio_t
*zio
)
1743 zio_t
*pio
= zio_unique_parent(zio
);
1744 ASSERTV(zio_t
*gio
= zio
->io_gang_leader
;)
1745 dva_t
*cdva
= zio
->io_bp
->blk_dva
;
1746 dva_t
*pdva
= pio
->io_bp
->blk_dva
;
1750 if (BP_IS_HOLE(zio
->io_bp
))
1753 ASSERT(BP_IS_HOLE(&zio
->io_bp_orig
));
1755 ASSERT(zio
->io_child_type
== ZIO_CHILD_GANG
);
1756 ASSERT3U(zio
->io_prop
.zp_copies
, ==, gio
->io_prop
.zp_copies
);
1757 ASSERT3U(zio
->io_prop
.zp_copies
, <=, BP_GET_NDVAS(zio
->io_bp
));
1758 ASSERT3U(pio
->io_prop
.zp_copies
, <=, BP_GET_NDVAS(pio
->io_bp
));
1759 ASSERT3U(BP_GET_NDVAS(zio
->io_bp
), <=, BP_GET_NDVAS(pio
->io_bp
));
1761 mutex_enter(&pio
->io_lock
);
1762 for (d
= 0; d
< BP_GET_NDVAS(zio
->io_bp
); d
++) {
1763 ASSERT(DVA_GET_GANG(&pdva
[d
]));
1764 asize
= DVA_GET_ASIZE(&pdva
[d
]);
1765 asize
+= DVA_GET_ASIZE(&cdva
[d
]);
1766 DVA_SET_ASIZE(&pdva
[d
], asize
);
1768 mutex_exit(&pio
->io_lock
);
1772 zio_write_gang_block(zio_t
*pio
)
1774 spa_t
*spa
= pio
->io_spa
;
1775 blkptr_t
*bp
= pio
->io_bp
;
1776 zio_t
*gio
= pio
->io_gang_leader
;
1778 zio_gang_node_t
*gn
, **gnpp
;
1779 zio_gbh_phys_t
*gbh
;
1780 uint64_t txg
= pio
->io_txg
;
1781 uint64_t resid
= pio
->io_size
;
1783 int copies
= gio
->io_prop
.zp_copies
;
1784 int gbh_copies
= MIN(copies
+ 1, spa_max_replication(spa
));
1788 error
= metaslab_alloc(spa
, spa_normal_class(spa
), SPA_GANGBLOCKSIZE
,
1789 bp
, gbh_copies
, txg
, pio
== gio
? NULL
: gio
->io_bp
,
1790 METASLAB_HINTBP_FAVOR
| METASLAB_GANG_HEADER
);
1792 pio
->io_error
= error
;
1793 return (ZIO_PIPELINE_CONTINUE
);
1797 gnpp
= &gio
->io_gang_tree
;
1799 gnpp
= pio
->io_private
;
1800 ASSERT(pio
->io_ready
== zio_write_gang_member_ready
);
1803 gn
= zio_gang_node_alloc(gnpp
);
1805 bzero(gbh
, SPA_GANGBLOCKSIZE
);
1808 * Create the gang header.
1810 zio
= zio_rewrite(pio
, spa
, txg
, bp
, gbh
, SPA_GANGBLOCKSIZE
, NULL
, NULL
,
1811 pio
->io_priority
, ZIO_GANG_CHILD_FLAGS(pio
), &pio
->io_bookmark
);
1814 * Create and nowait the gang children.
1816 for (g
= 0; resid
!= 0; resid
-= lsize
, g
++) {
1817 lsize
= P2ROUNDUP(resid
/ (SPA_GBH_NBLKPTRS
- g
),
1819 ASSERT(lsize
>= SPA_MINBLOCKSIZE
&& lsize
<= resid
);
1821 zp
.zp_checksum
= gio
->io_prop
.zp_checksum
;
1822 zp
.zp_compress
= ZIO_COMPRESS_OFF
;
1823 zp
.zp_type
= DMU_OT_NONE
;
1825 zp
.zp_copies
= gio
->io_prop
.zp_copies
;
1827 zp
.zp_dedup_verify
= 0;
1829 zio_nowait(zio_write(zio
, spa
, txg
, &gbh
->zg_blkptr
[g
],
1830 (char *)pio
->io_data
+ (pio
->io_size
- resid
), lsize
, &zp
,
1831 zio_write_gang_member_ready
, NULL
, &gn
->gn_child
[g
],
1832 pio
->io_priority
, ZIO_GANG_CHILD_FLAGS(pio
),
1833 &pio
->io_bookmark
));
1837 * Set pio's pipeline to just wait for zio to finish.
1839 pio
->io_pipeline
= ZIO_INTERLOCK_PIPELINE
;
1843 return (ZIO_PIPELINE_CONTINUE
);
1847 * ==========================================================================
1849 * ==========================================================================
1852 zio_ddt_child_read_done(zio_t
*zio
)
1854 blkptr_t
*bp
= zio
->io_bp
;
1855 ddt_entry_t
*dde
= zio
->io_private
;
1857 zio_t
*pio
= zio_unique_parent(zio
);
1859 mutex_enter(&pio
->io_lock
);
1860 ddp
= ddt_phys_select(dde
, bp
);
1861 if (zio
->io_error
== 0)
1862 ddt_phys_clear(ddp
); /* this ddp doesn't need repair */
1863 if (zio
->io_error
== 0 && dde
->dde_repair_data
== NULL
)
1864 dde
->dde_repair_data
= zio
->io_data
;
1866 zio_buf_free(zio
->io_data
, zio
->io_size
);
1867 mutex_exit(&pio
->io_lock
);
1871 zio_ddt_read_start(zio_t
*zio
)
1873 blkptr_t
*bp
= zio
->io_bp
;
1876 ASSERT(BP_GET_DEDUP(bp
));
1877 ASSERT(BP_GET_PSIZE(bp
) == zio
->io_size
);
1878 ASSERT(zio
->io_child_type
== ZIO_CHILD_LOGICAL
);
1880 if (zio
->io_child_error
[ZIO_CHILD_DDT
]) {
1881 ddt_t
*ddt
= ddt_select(zio
->io_spa
, bp
);
1882 ddt_entry_t
*dde
= ddt_repair_start(ddt
, bp
);
1883 ddt_phys_t
*ddp
= dde
->dde_phys
;
1884 ddt_phys_t
*ddp_self
= ddt_phys_select(dde
, bp
);
1887 ASSERT(zio
->io_vsd
== NULL
);
1890 if (ddp_self
== NULL
)
1891 return (ZIO_PIPELINE_CONTINUE
);
1893 for (p
= 0; p
< DDT_PHYS_TYPES
; p
++, ddp
++) {
1894 if (ddp
->ddp_phys_birth
== 0 || ddp
== ddp_self
)
1896 ddt_bp_create(ddt
->ddt_checksum
, &dde
->dde_key
, ddp
,
1898 zio_nowait(zio_read(zio
, zio
->io_spa
, &blk
,
1899 zio_buf_alloc(zio
->io_size
), zio
->io_size
,
1900 zio_ddt_child_read_done
, dde
, zio
->io_priority
,
1901 ZIO_DDT_CHILD_FLAGS(zio
) | ZIO_FLAG_DONT_PROPAGATE
,
1902 &zio
->io_bookmark
));
1904 return (ZIO_PIPELINE_CONTINUE
);
1907 zio_nowait(zio_read(zio
, zio
->io_spa
, bp
,
1908 zio
->io_data
, zio
->io_size
, NULL
, NULL
, zio
->io_priority
,
1909 ZIO_DDT_CHILD_FLAGS(zio
), &zio
->io_bookmark
));
1911 return (ZIO_PIPELINE_CONTINUE
);
1915 zio_ddt_read_done(zio_t
*zio
)
1917 blkptr_t
*bp
= zio
->io_bp
;
1919 if (zio_wait_for_children(zio
, ZIO_CHILD_DDT
, ZIO_WAIT_DONE
))
1920 return (ZIO_PIPELINE_STOP
);
1922 ASSERT(BP_GET_DEDUP(bp
));
1923 ASSERT(BP_GET_PSIZE(bp
) == zio
->io_size
);
1924 ASSERT(zio
->io_child_type
== ZIO_CHILD_LOGICAL
);
1926 if (zio
->io_child_error
[ZIO_CHILD_DDT
]) {
1927 ddt_t
*ddt
= ddt_select(zio
->io_spa
, bp
);
1928 ddt_entry_t
*dde
= zio
->io_vsd
;
1930 ASSERT(spa_load_state(zio
->io_spa
) != SPA_LOAD_NONE
);
1931 return (ZIO_PIPELINE_CONTINUE
);
1934 zio
->io_stage
= ZIO_STAGE_DDT_READ_START
>> 1;
1935 zio_taskq_dispatch(zio
, ZIO_TASKQ_ISSUE
, B_FALSE
);
1936 return (ZIO_PIPELINE_STOP
);
1938 if (dde
->dde_repair_data
!= NULL
) {
1939 bcopy(dde
->dde_repair_data
, zio
->io_data
, zio
->io_size
);
1940 zio
->io_child_error
[ZIO_CHILD_DDT
] = 0;
1942 ddt_repair_done(ddt
, dde
);
1946 ASSERT(zio
->io_vsd
== NULL
);
1948 return (ZIO_PIPELINE_CONTINUE
);
1952 zio_ddt_collision(zio_t
*zio
, ddt_t
*ddt
, ddt_entry_t
*dde
)
1954 spa_t
*spa
= zio
->io_spa
;
1958 * Note: we compare the original data, not the transformed data,
1959 * because when zio->io_bp is an override bp, we will not have
1960 * pushed the I/O transforms. That's an important optimization
1961 * because otherwise we'd compress/encrypt all dmu_sync() data twice.
1963 for (p
= DDT_PHYS_SINGLE
; p
<= DDT_PHYS_TRIPLE
; p
++) {
1964 zio_t
*lio
= dde
->dde_lead_zio
[p
];
1967 return (lio
->io_orig_size
!= zio
->io_orig_size
||
1968 bcmp(zio
->io_orig_data
, lio
->io_orig_data
,
1969 zio
->io_orig_size
) != 0);
1973 for (p
= DDT_PHYS_SINGLE
; p
<= DDT_PHYS_TRIPLE
; p
++) {
1974 ddt_phys_t
*ddp
= &dde
->dde_phys
[p
];
1976 if (ddp
->ddp_phys_birth
!= 0) {
1977 arc_buf_t
*abuf
= NULL
;
1978 uint32_t aflags
= ARC_WAIT
;
1979 blkptr_t blk
= *zio
->io_bp
;
1982 ddt_bp_fill(ddp
, &blk
, ddp
->ddp_phys_birth
);
1986 error
= arc_read_nolock(NULL
, spa
, &blk
,
1987 arc_getbuf_func
, &abuf
, ZIO_PRIORITY_SYNC_READ
,
1988 ZIO_FLAG_CANFAIL
| ZIO_FLAG_SPECULATIVE
,
1989 &aflags
, &zio
->io_bookmark
);
1992 if (arc_buf_size(abuf
) != zio
->io_orig_size
||
1993 bcmp(abuf
->b_data
, zio
->io_orig_data
,
1994 zio
->io_orig_size
) != 0)
1996 VERIFY(arc_buf_remove_ref(abuf
, &abuf
) == 1);
2000 return (error
!= 0);
2008 zio_ddt_child_write_ready(zio_t
*zio
)
2010 int p
= zio
->io_prop
.zp_copies
;
2011 ddt_t
*ddt
= ddt_select(zio
->io_spa
, zio
->io_bp
);
2012 ddt_entry_t
*dde
= zio
->io_private
;
2013 ddt_phys_t
*ddp
= &dde
->dde_phys
[p
];
2021 ASSERT(dde
->dde_lead_zio
[p
] == zio
);
2023 ddt_phys_fill(ddp
, zio
->io_bp
);
2025 while ((pio
= zio_walk_parents(zio
)) != NULL
)
2026 ddt_bp_fill(ddp
, pio
->io_bp
, zio
->io_txg
);
2032 zio_ddt_child_write_done(zio_t
*zio
)
2034 int p
= zio
->io_prop
.zp_copies
;
2035 ddt_t
*ddt
= ddt_select(zio
->io_spa
, zio
->io_bp
);
2036 ddt_entry_t
*dde
= zio
->io_private
;
2037 ddt_phys_t
*ddp
= &dde
->dde_phys
[p
];
2041 ASSERT(ddp
->ddp_refcnt
== 0);
2042 ASSERT(dde
->dde_lead_zio
[p
] == zio
);
2043 dde
->dde_lead_zio
[p
] = NULL
;
2045 if (zio
->io_error
== 0) {
2046 while (zio_walk_parents(zio
) != NULL
)
2047 ddt_phys_addref(ddp
);
2049 ddt_phys_clear(ddp
);
2056 zio_ddt_ditto_write_done(zio_t
*zio
)
2058 int p
= DDT_PHYS_DITTO
;
2059 blkptr_t
*bp
= zio
->io_bp
;
2060 ddt_t
*ddt
= ddt_select(zio
->io_spa
, bp
);
2061 ddt_entry_t
*dde
= zio
->io_private
;
2062 ddt_phys_t
*ddp
= &dde
->dde_phys
[p
];
2063 ddt_key_t
*ddk
= &dde
->dde_key
;
2064 ASSERTV(zio_prop_t
*zp
= &zio
->io_prop
);
2068 ASSERT(ddp
->ddp_refcnt
== 0);
2069 ASSERT(dde
->dde_lead_zio
[p
] == zio
);
2070 dde
->dde_lead_zio
[p
] = NULL
;
2072 if (zio
->io_error
== 0) {
2073 ASSERT(ZIO_CHECKSUM_EQUAL(bp
->blk_cksum
, ddk
->ddk_cksum
));
2074 ASSERT(zp
->zp_copies
< SPA_DVAS_PER_BP
);
2075 ASSERT(zp
->zp_copies
== BP_GET_NDVAS(bp
) - BP_IS_GANG(bp
));
2076 if (ddp
->ddp_phys_birth
!= 0)
2077 ddt_phys_free(ddt
, ddk
, ddp
, zio
->io_txg
);
2078 ddt_phys_fill(ddp
, bp
);
2085 zio_ddt_write(zio_t
*zio
)
2087 spa_t
*spa
= zio
->io_spa
;
2088 blkptr_t
*bp
= zio
->io_bp
;
2089 uint64_t txg
= zio
->io_txg
;
2090 zio_prop_t
*zp
= &zio
->io_prop
;
2091 int p
= zp
->zp_copies
;
2095 ddt_t
*ddt
= ddt_select(spa
, bp
);
2099 ASSERT(BP_GET_DEDUP(bp
));
2100 ASSERT(BP_GET_CHECKSUM(bp
) == zp
->zp_checksum
);
2101 ASSERT(BP_IS_HOLE(bp
) || zio
->io_bp_override
);
2104 dde
= ddt_lookup(ddt
, bp
, B_TRUE
);
2105 ddp
= &dde
->dde_phys
[p
];
2107 if (zp
->zp_dedup_verify
&& zio_ddt_collision(zio
, ddt
, dde
)) {
2109 * If we're using a weak checksum, upgrade to a strong checksum
2110 * and try again. If we're already using a strong checksum,
2111 * we can't resolve it, so just convert to an ordinary write.
2112 * (And automatically e-mail a paper to Nature?)
2114 if (!zio_checksum_table
[zp
->zp_checksum
].ci_dedup
) {
2115 zp
->zp_checksum
= spa_dedup_checksum(spa
);
2116 zio_pop_transforms(zio
);
2117 zio
->io_stage
= ZIO_STAGE_OPEN
;
2122 zio
->io_pipeline
= ZIO_WRITE_PIPELINE
;
2124 return (ZIO_PIPELINE_CONTINUE
);
2127 ditto_copies
= ddt_ditto_copies_needed(ddt
, dde
, ddp
);
2128 ASSERT(ditto_copies
< SPA_DVAS_PER_BP
);
2130 if (ditto_copies
> ddt_ditto_copies_present(dde
) &&
2131 dde
->dde_lead_zio
[DDT_PHYS_DITTO
] == NULL
) {
2132 zio_prop_t czp
= *zp
;
2134 czp
.zp_copies
= ditto_copies
;
2137 * If we arrived here with an override bp, we won't have run
2138 * the transform stack, so we won't have the data we need to
2139 * generate a child i/o. So, toss the override bp and restart.
2140 * This is safe, because using the override bp is just an
2141 * optimization; and it's rare, so the cost doesn't matter.
2143 if (zio
->io_bp_override
) {
2144 zio_pop_transforms(zio
);
2145 zio
->io_stage
= ZIO_STAGE_OPEN
;
2146 zio
->io_pipeline
= ZIO_WRITE_PIPELINE
;
2147 zio
->io_bp_override
= NULL
;
2150 return (ZIO_PIPELINE_CONTINUE
);
2153 dio
= zio_write(zio
, spa
, txg
, bp
, zio
->io_orig_data
,
2154 zio
->io_orig_size
, &czp
, NULL
,
2155 zio_ddt_ditto_write_done
, dde
, zio
->io_priority
,
2156 ZIO_DDT_CHILD_FLAGS(zio
), &zio
->io_bookmark
);
2158 zio_push_transform(dio
, zio
->io_data
, zio
->io_size
, 0, NULL
);
2159 dde
->dde_lead_zio
[DDT_PHYS_DITTO
] = dio
;
2162 if (ddp
->ddp_phys_birth
!= 0 || dde
->dde_lead_zio
[p
] != NULL
) {
2163 if (ddp
->ddp_phys_birth
!= 0)
2164 ddt_bp_fill(ddp
, bp
, txg
);
2165 if (dde
->dde_lead_zio
[p
] != NULL
)
2166 zio_add_child(zio
, dde
->dde_lead_zio
[p
]);
2168 ddt_phys_addref(ddp
);
2169 } else if (zio
->io_bp_override
) {
2170 ASSERT(bp
->blk_birth
== txg
);
2171 ASSERT(BP_EQUAL(bp
, zio
->io_bp_override
));
2172 ddt_phys_fill(ddp
, bp
);
2173 ddt_phys_addref(ddp
);
2175 cio
= zio_write(zio
, spa
, txg
, bp
, zio
->io_orig_data
,
2176 zio
->io_orig_size
, zp
, zio_ddt_child_write_ready
,
2177 zio_ddt_child_write_done
, dde
, zio
->io_priority
,
2178 ZIO_DDT_CHILD_FLAGS(zio
), &zio
->io_bookmark
);
2180 zio_push_transform(cio
, zio
->io_data
, zio
->io_size
, 0, NULL
);
2181 dde
->dde_lead_zio
[p
] = cio
;
2191 return (ZIO_PIPELINE_CONTINUE
);
2194 ddt_entry_t
*freedde
; /* for debugging */
2197 zio_ddt_free(zio_t
*zio
)
2199 spa_t
*spa
= zio
->io_spa
;
2200 blkptr_t
*bp
= zio
->io_bp
;
2201 ddt_t
*ddt
= ddt_select(spa
, bp
);
2205 ASSERT(BP_GET_DEDUP(bp
));
2206 ASSERT(zio
->io_child_type
== ZIO_CHILD_LOGICAL
);
2209 freedde
= dde
= ddt_lookup(ddt
, bp
, B_TRUE
);
2210 ddp
= ddt_phys_select(dde
, bp
);
2211 ddt_phys_decref(ddp
);
2214 return (ZIO_PIPELINE_CONTINUE
);
2218 * ==========================================================================
2219 * Allocate and free blocks
2220 * ==========================================================================
2223 zio_dva_allocate(zio_t
*zio
)
2225 spa_t
*spa
= zio
->io_spa
;
2226 metaslab_class_t
*mc
= spa_normal_class(spa
);
2227 blkptr_t
*bp
= zio
->io_bp
;
2231 if (zio
->io_gang_leader
== NULL
) {
2232 ASSERT(zio
->io_child_type
> ZIO_CHILD_GANG
);
2233 zio
->io_gang_leader
= zio
;
2236 ASSERT(BP_IS_HOLE(bp
));
2237 ASSERT3U(BP_GET_NDVAS(bp
), ==, 0);
2238 ASSERT3U(zio
->io_prop
.zp_copies
, >, 0);
2239 ASSERT3U(zio
->io_prop
.zp_copies
, <=, spa_max_replication(spa
));
2240 ASSERT3U(zio
->io_size
, ==, BP_GET_PSIZE(bp
));
2243 * The dump device does not support gang blocks so allocation on
2244 * behalf of the dump device (i.e. ZIO_FLAG_NODATA) must avoid
2245 * the "fast" gang feature.
2247 flags
|= (zio
->io_flags
& ZIO_FLAG_NODATA
) ? METASLAB_GANG_AVOID
: 0;
2248 flags
|= (zio
->io_flags
& ZIO_FLAG_GANG_CHILD
) ?
2249 METASLAB_GANG_CHILD
: 0;
2250 error
= metaslab_alloc(spa
, mc
, zio
->io_size
, bp
,
2251 zio
->io_prop
.zp_copies
, zio
->io_txg
, NULL
, flags
);
2254 spa_dbgmsg(spa
, "%s: metaslab allocation failure: zio %p, "
2255 "size %llu, error %d", spa_name(spa
), zio
, zio
->io_size
,
2257 if (error
== ENOSPC
&& zio
->io_size
> SPA_MINBLOCKSIZE
)
2258 return (zio_write_gang_block(zio
));
2259 zio
->io_error
= error
;
2262 return (ZIO_PIPELINE_CONTINUE
);
2266 zio_dva_free(zio_t
*zio
)
2268 metaslab_free(zio
->io_spa
, zio
->io_bp
, zio
->io_txg
, B_FALSE
);
2270 return (ZIO_PIPELINE_CONTINUE
);
2274 zio_dva_claim(zio_t
*zio
)
2278 error
= metaslab_claim(zio
->io_spa
, zio
->io_bp
, zio
->io_txg
);
2280 zio
->io_error
= error
;
2282 return (ZIO_PIPELINE_CONTINUE
);
2286 * Undo an allocation. This is used by zio_done() when an I/O fails
2287 * and we want to give back the block we just allocated.
2288 * This handles both normal blocks and gang blocks.
2291 zio_dva_unallocate(zio_t
*zio
, zio_gang_node_t
*gn
, blkptr_t
*bp
)
2295 ASSERT(bp
->blk_birth
== zio
->io_txg
|| BP_IS_HOLE(bp
));
2296 ASSERT(zio
->io_bp_override
== NULL
);
2298 if (!BP_IS_HOLE(bp
))
2299 metaslab_free(zio
->io_spa
, bp
, bp
->blk_birth
, B_TRUE
);
2302 for (g
= 0; g
< SPA_GBH_NBLKPTRS
; g
++) {
2303 zio_dva_unallocate(zio
, gn
->gn_child
[g
],
2304 &gn
->gn_gbh
->zg_blkptr
[g
]);
2310 * Try to allocate an intent log block. Return 0 on success, errno on failure.
2313 zio_alloc_zil(spa_t
*spa
, uint64_t txg
, blkptr_t
*new_bp
, blkptr_t
*old_bp
,
2314 uint64_t size
, boolean_t use_slog
)
2318 ASSERT(txg
> spa_syncing_txg(spa
));
2321 * ZIL blocks are always contiguous (i.e. not gang blocks) so we
2322 * set the METASLAB_GANG_AVOID flag so that they don't "fast gang"
2323 * when allocating them.
2326 error
= metaslab_alloc(spa
, spa_log_class(spa
), size
,
2327 new_bp
, 1, txg
, old_bp
,
2328 METASLAB_HINTBP_AVOID
| METASLAB_GANG_AVOID
);
2332 error
= metaslab_alloc(spa
, spa_normal_class(spa
), size
,
2333 new_bp
, 1, txg
, old_bp
,
2334 METASLAB_HINTBP_AVOID
| METASLAB_GANG_AVOID
);
2338 BP_SET_LSIZE(new_bp
, size
);
2339 BP_SET_PSIZE(new_bp
, size
);
2340 BP_SET_COMPRESS(new_bp
, ZIO_COMPRESS_OFF
);
2341 BP_SET_CHECKSUM(new_bp
,
2342 spa_version(spa
) >= SPA_VERSION_SLIM_ZIL
2343 ? ZIO_CHECKSUM_ZILOG2
: ZIO_CHECKSUM_ZILOG
);
2344 BP_SET_TYPE(new_bp
, DMU_OT_INTENT_LOG
);
2345 BP_SET_LEVEL(new_bp
, 0);
2346 BP_SET_DEDUP(new_bp
, 0);
2347 BP_SET_BYTEORDER(new_bp
, ZFS_HOST_BYTEORDER
);
2354 * Free an intent log block.
2357 zio_free_zil(spa_t
*spa
, uint64_t txg
, blkptr_t
*bp
)
2359 ASSERT(BP_GET_TYPE(bp
) == DMU_OT_INTENT_LOG
);
2360 ASSERT(!BP_IS_GANG(bp
));
2362 zio_free(spa
, txg
, bp
);
2366 * ==========================================================================
2367 * Read and write to physical devices
2368 * ==========================================================================
2371 zio_vdev_io_start(zio_t
*zio
)
2373 vdev_t
*vd
= zio
->io_vd
;
2375 spa_t
*spa
= zio
->io_spa
;
2377 ASSERT(zio
->io_error
== 0);
2378 ASSERT(zio
->io_child_error
[ZIO_CHILD_VDEV
] == 0);
2381 if (!(zio
->io_flags
& ZIO_FLAG_CONFIG_WRITER
))
2382 spa_config_enter(spa
, SCL_ZIO
, zio
, RW_READER
);
2385 * The mirror_ops handle multiple DVAs in a single BP.
2387 return (vdev_mirror_ops
.vdev_op_io_start(zio
));
2391 * We keep track of time-sensitive I/Os so that the scan thread
2392 * can quickly react to certain workloads. In particular, we care
2393 * about non-scrubbing, top-level reads and writes with the following
2395 * - synchronous writes of user data to non-slog devices
2396 * - any reads of user data
2397 * When these conditions are met, adjust the timestamp of spa_last_io
2398 * which allows the scan thread to adjust its workload accordingly.
2400 if (!(zio
->io_flags
& ZIO_FLAG_SCAN_THREAD
) && zio
->io_bp
!= NULL
&&
2401 vd
== vd
->vdev_top
&& !vd
->vdev_islog
&&
2402 zio
->io_bookmark
.zb_objset
!= DMU_META_OBJSET
&&
2403 zio
->io_txg
!= spa_syncing_txg(spa
)) {
2404 uint64_t old
= spa
->spa_last_io
;
2405 uint64_t new = ddi_get_lbolt64();
2407 (void) atomic_cas_64(&spa
->spa_last_io
, old
, new);
2410 align
= 1ULL << vd
->vdev_top
->vdev_ashift
;
2412 if (P2PHASE(zio
->io_size
, align
) != 0) {
2413 uint64_t asize
= P2ROUNDUP(zio
->io_size
, align
);
2414 char *abuf
= zio_buf_alloc(asize
);
2415 ASSERT(vd
== vd
->vdev_top
);
2416 if (zio
->io_type
== ZIO_TYPE_WRITE
) {
2417 bcopy(zio
->io_data
, abuf
, zio
->io_size
);
2418 bzero(abuf
+ zio
->io_size
, asize
- zio
->io_size
);
2420 zio_push_transform(zio
, abuf
, asize
, asize
, zio_subblock
);
2423 ASSERT(P2PHASE(zio
->io_offset
, align
) == 0);
2424 ASSERT(P2PHASE(zio
->io_size
, align
) == 0);
2425 VERIFY(zio
->io_type
!= ZIO_TYPE_WRITE
|| spa_writeable(spa
));
2428 * If this is a repair I/O, and there's no self-healing involved --
2429 * that is, we're just resilvering what we expect to resilver --
2430 * then don't do the I/O unless zio's txg is actually in vd's DTL.
2431 * This prevents spurious resilvering with nested replication.
2432 * For example, given a mirror of mirrors, (A+B)+(C+D), if only
2433 * A is out of date, we'll read from C+D, then use the data to
2434 * resilver A+B -- but we don't actually want to resilver B, just A.
2435 * The top-level mirror has no way to know this, so instead we just
2436 * discard unnecessary repairs as we work our way down the vdev tree.
2437 * The same logic applies to any form of nested replication:
2438 * ditto + mirror, RAID-Z + replacing, etc. This covers them all.
2440 if ((zio
->io_flags
& ZIO_FLAG_IO_REPAIR
) &&
2441 !(zio
->io_flags
& ZIO_FLAG_SELF_HEAL
) &&
2442 zio
->io_txg
!= 0 && /* not a delegated i/o */
2443 !vdev_dtl_contains(vd
, DTL_PARTIAL
, zio
->io_txg
, 1)) {
2444 ASSERT(zio
->io_type
== ZIO_TYPE_WRITE
);
2445 zio_vdev_io_bypass(zio
);
2446 return (ZIO_PIPELINE_CONTINUE
);
2449 if (vd
->vdev_ops
->vdev_op_leaf
&&
2450 (zio
->io_type
== ZIO_TYPE_READ
|| zio
->io_type
== ZIO_TYPE_WRITE
)) {
2452 if (zio
->io_type
== ZIO_TYPE_READ
&& vdev_cache_read(zio
) == 0)
2453 return (ZIO_PIPELINE_CONTINUE
);
2455 if ((zio
= vdev_queue_io(zio
)) == NULL
)
2456 return (ZIO_PIPELINE_STOP
);
2458 if (!vdev_accessible(vd
, zio
)) {
2459 zio
->io_error
= ENXIO
;
2461 return (ZIO_PIPELINE_STOP
);
2465 return (vd
->vdev_ops
->vdev_op_io_start(zio
));
2469 zio_vdev_io_done(zio_t
*zio
)
2471 vdev_t
*vd
= zio
->io_vd
;
2472 vdev_ops_t
*ops
= vd
? vd
->vdev_ops
: &vdev_mirror_ops
;
2473 boolean_t unexpected_error
= B_FALSE
;
2475 if (zio_wait_for_children(zio
, ZIO_CHILD_VDEV
, ZIO_WAIT_DONE
))
2476 return (ZIO_PIPELINE_STOP
);
2478 ASSERT(zio
->io_type
== ZIO_TYPE_READ
|| zio
->io_type
== ZIO_TYPE_WRITE
);
2480 if (vd
!= NULL
&& vd
->vdev_ops
->vdev_op_leaf
) {
2482 vdev_queue_io_done(zio
);
2484 if (zio
->io_type
== ZIO_TYPE_WRITE
)
2485 vdev_cache_write(zio
);
2487 if (zio_injection_enabled
&& zio
->io_error
== 0)
2488 zio
->io_error
= zio_handle_device_injection(vd
,
2491 if (zio_injection_enabled
&& zio
->io_error
== 0)
2492 zio
->io_error
= zio_handle_label_injection(zio
, EIO
);
2494 if (zio
->io_error
) {
2495 if (!vdev_accessible(vd
, zio
)) {
2496 zio
->io_error
= ENXIO
;
2498 unexpected_error
= B_TRUE
;
2503 ops
->vdev_op_io_done(zio
);
2505 if (unexpected_error
)
2506 VERIFY(vdev_probe(vd
, zio
) == NULL
);
2508 return (ZIO_PIPELINE_CONTINUE
);
2512 * For non-raidz ZIOs, we can just copy aside the bad data read from the
2513 * disk, and use that to finish the checksum ereport later.
2516 zio_vsd_default_cksum_finish(zio_cksum_report_t
*zcr
,
2517 const void *good_buf
)
2519 /* no processing needed */
2520 zfs_ereport_finish_checksum(zcr
, good_buf
, zcr
->zcr_cbdata
, B_FALSE
);
2525 zio_vsd_default_cksum_report(zio_t
*zio
, zio_cksum_report_t
*zcr
, void *ignored
)
2527 void *buf
= zio_buf_alloc(zio
->io_size
);
2529 bcopy(zio
->io_data
, buf
, zio
->io_size
);
2531 zcr
->zcr_cbinfo
= zio
->io_size
;
2532 zcr
->zcr_cbdata
= buf
;
2533 zcr
->zcr_finish
= zio_vsd_default_cksum_finish
;
2534 zcr
->zcr_free
= zio_buf_free
;
2538 zio_vdev_io_assess(zio_t
*zio
)
2540 vdev_t
*vd
= zio
->io_vd
;
2542 if (zio_wait_for_children(zio
, ZIO_CHILD_VDEV
, ZIO_WAIT_DONE
))
2543 return (ZIO_PIPELINE_STOP
);
2545 if (vd
== NULL
&& !(zio
->io_flags
& ZIO_FLAG_CONFIG_WRITER
))
2546 spa_config_exit(zio
->io_spa
, SCL_ZIO
, zio
);
2548 if (zio
->io_vsd
!= NULL
) {
2549 zio
->io_vsd_ops
->vsd_free(zio
);
2553 if (zio_injection_enabled
&& zio
->io_error
== 0)
2554 zio
->io_error
= zio_handle_fault_injection(zio
, EIO
);
2557 * If the I/O failed, determine whether we should attempt to retry it.
2559 * On retry, we cut in line in the issue queue, since we don't want
2560 * compression/checksumming/etc. work to prevent our (cheap) IO reissue.
2562 if (zio
->io_error
&& vd
== NULL
&&
2563 !(zio
->io_flags
& (ZIO_FLAG_DONT_RETRY
| ZIO_FLAG_IO_RETRY
))) {
2564 ASSERT(!(zio
->io_flags
& ZIO_FLAG_DONT_QUEUE
)); /* not a leaf */
2565 ASSERT(!(zio
->io_flags
& ZIO_FLAG_IO_BYPASS
)); /* not a leaf */
2567 zio
->io_flags
|= ZIO_FLAG_IO_RETRY
|
2568 ZIO_FLAG_DONT_CACHE
| ZIO_FLAG_DONT_AGGREGATE
;
2569 zio
->io_stage
= ZIO_STAGE_VDEV_IO_START
>> 1;
2570 zio_taskq_dispatch(zio
, ZIO_TASKQ_ISSUE
,
2571 zio_requeue_io_start_cut_in_line
);
2572 return (ZIO_PIPELINE_STOP
);
2576 * If we got an error on a leaf device, convert it to ENXIO
2577 * if the device is not accessible at all.
2579 if (zio
->io_error
&& vd
!= NULL
&& vd
->vdev_ops
->vdev_op_leaf
&&
2580 !vdev_accessible(vd
, zio
))
2581 zio
->io_error
= ENXIO
;
2584 * If we can't write to an interior vdev (mirror or RAID-Z),
2585 * set vdev_cant_write so that we stop trying to allocate from it.
2587 if (zio
->io_error
== ENXIO
&& zio
->io_type
== ZIO_TYPE_WRITE
&&
2588 vd
!= NULL
&& !vd
->vdev_ops
->vdev_op_leaf
)
2589 vd
->vdev_cant_write
= B_TRUE
;
2592 zio
->io_pipeline
= ZIO_INTERLOCK_PIPELINE
;
2594 return (ZIO_PIPELINE_CONTINUE
);
2598 zio_vdev_io_reissue(zio_t
*zio
)
2600 ASSERT(zio
->io_stage
== ZIO_STAGE_VDEV_IO_START
);
2601 ASSERT(zio
->io_error
== 0);
2603 zio
->io_stage
>>= 1;
2607 zio_vdev_io_redone(zio_t
*zio
)
2609 ASSERT(zio
->io_stage
== ZIO_STAGE_VDEV_IO_DONE
);
2611 zio
->io_stage
>>= 1;
2615 zio_vdev_io_bypass(zio_t
*zio
)
2617 ASSERT(zio
->io_stage
== ZIO_STAGE_VDEV_IO_START
);
2618 ASSERT(zio
->io_error
== 0);
2620 zio
->io_flags
|= ZIO_FLAG_IO_BYPASS
;
2621 zio
->io_stage
= ZIO_STAGE_VDEV_IO_ASSESS
>> 1;
2625 * ==========================================================================
2626 * Generate and verify checksums
2627 * ==========================================================================
2630 zio_checksum_generate(zio_t
*zio
)
2632 blkptr_t
*bp
= zio
->io_bp
;
2633 enum zio_checksum checksum
;
2637 * This is zio_write_phys().
2638 * We're either generating a label checksum, or none at all.
2640 checksum
= zio
->io_prop
.zp_checksum
;
2642 if (checksum
== ZIO_CHECKSUM_OFF
)
2643 return (ZIO_PIPELINE_CONTINUE
);
2645 ASSERT(checksum
== ZIO_CHECKSUM_LABEL
);
2647 if (BP_IS_GANG(bp
) && zio
->io_child_type
== ZIO_CHILD_GANG
) {
2648 ASSERT(!IO_IS_ALLOCATING(zio
));
2649 checksum
= ZIO_CHECKSUM_GANG_HEADER
;
2651 checksum
= BP_GET_CHECKSUM(bp
);
2655 zio_checksum_compute(zio
, checksum
, zio
->io_data
, zio
->io_size
);
2657 return (ZIO_PIPELINE_CONTINUE
);
2661 zio_checksum_verify(zio_t
*zio
)
2663 zio_bad_cksum_t info
;
2664 blkptr_t
*bp
= zio
->io_bp
;
2667 ASSERT(zio
->io_vd
!= NULL
);
2671 * This is zio_read_phys().
2672 * We're either verifying a label checksum, or nothing at all.
2674 if (zio
->io_prop
.zp_checksum
== ZIO_CHECKSUM_OFF
)
2675 return (ZIO_PIPELINE_CONTINUE
);
2677 ASSERT(zio
->io_prop
.zp_checksum
== ZIO_CHECKSUM_LABEL
);
2680 if ((error
= zio_checksum_error(zio
, &info
)) != 0) {
2681 zio
->io_error
= error
;
2682 if (!(zio
->io_flags
& ZIO_FLAG_SPECULATIVE
)) {
2683 zfs_ereport_start_checksum(zio
->io_spa
,
2684 zio
->io_vd
, zio
, zio
->io_offset
,
2685 zio
->io_size
, NULL
, &info
);
2689 return (ZIO_PIPELINE_CONTINUE
);
2693 * Called by RAID-Z to ensure we don't compute the checksum twice.
2696 zio_checksum_verified(zio_t
*zio
)
2698 zio
->io_pipeline
&= ~ZIO_STAGE_CHECKSUM_VERIFY
;
2702 * ==========================================================================
2703 * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other.
2704 * An error of 0 indictes success. ENXIO indicates whole-device failure,
2705 * which may be transient (e.g. unplugged) or permament. ECKSUM and EIO
2706 * indicate errors that are specific to one I/O, and most likely permanent.
2707 * Any other error is presumed to be worse because we weren't expecting it.
2708 * ==========================================================================
2711 zio_worst_error(int e1
, int e2
)
2713 static int zio_error_rank
[] = { 0, ENXIO
, ECKSUM
, EIO
};
2716 for (r1
= 0; r1
< sizeof (zio_error_rank
) / sizeof (int); r1
++)
2717 if (e1
== zio_error_rank
[r1
])
2720 for (r2
= 0; r2
< sizeof (zio_error_rank
) / sizeof (int); r2
++)
2721 if (e2
== zio_error_rank
[r2
])
2724 return (r1
> r2
? e1
: e2
);
2728 * ==========================================================================
2730 * ==========================================================================
2733 zio_ready(zio_t
*zio
)
2735 blkptr_t
*bp
= zio
->io_bp
;
2736 zio_t
*pio
, *pio_next
;
2738 if (zio_wait_for_children(zio
, ZIO_CHILD_GANG
, ZIO_WAIT_READY
) ||
2739 zio_wait_for_children(zio
, ZIO_CHILD_DDT
, ZIO_WAIT_READY
))
2740 return (ZIO_PIPELINE_STOP
);
2742 if (zio
->io_ready
) {
2743 ASSERT(IO_IS_ALLOCATING(zio
));
2744 ASSERT(bp
->blk_birth
== zio
->io_txg
|| BP_IS_HOLE(bp
));
2745 ASSERT(zio
->io_children
[ZIO_CHILD_GANG
][ZIO_WAIT_READY
] == 0);
2750 if (bp
!= NULL
&& bp
!= &zio
->io_bp_copy
)
2751 zio
->io_bp_copy
= *bp
;
2754 zio
->io_pipeline
= ZIO_INTERLOCK_PIPELINE
;
2756 mutex_enter(&zio
->io_lock
);
2757 zio
->io_state
[ZIO_WAIT_READY
] = 1;
2758 pio
= zio_walk_parents(zio
);
2759 mutex_exit(&zio
->io_lock
);
2762 * As we notify zio's parents, new parents could be added.
2763 * New parents go to the head of zio's io_parent_list, however,
2764 * so we will (correctly) not notify them. The remainder of zio's
2765 * io_parent_list, from 'pio_next' onward, cannot change because
2766 * all parents must wait for us to be done before they can be done.
2768 for (; pio
!= NULL
; pio
= pio_next
) {
2769 pio_next
= zio_walk_parents(zio
);
2770 zio_notify_parent(pio
, zio
, ZIO_WAIT_READY
);
2773 if (zio
->io_flags
& ZIO_FLAG_NODATA
) {
2774 if (BP_IS_GANG(bp
)) {
2775 zio
->io_flags
&= ~ZIO_FLAG_NODATA
;
2777 ASSERT((uintptr_t)zio
->io_data
< SPA_MAXBLOCKSIZE
);
2778 zio
->io_pipeline
&= ~ZIO_VDEV_IO_STAGES
;
2782 if (zio_injection_enabled
&&
2783 zio
->io_spa
->spa_syncing_txg
== zio
->io_txg
)
2784 zio_handle_ignored_writes(zio
);
2786 return (ZIO_PIPELINE_CONTINUE
);
2790 zio_done(zio_t
*zio
)
2792 zio_t
*pio
, *pio_next
;
2796 * If our children haven't all completed,
2797 * wait for them and then repeat this pipeline stage.
2799 if (zio_wait_for_children(zio
, ZIO_CHILD_VDEV
, ZIO_WAIT_DONE
) ||
2800 zio_wait_for_children(zio
, ZIO_CHILD_GANG
, ZIO_WAIT_DONE
) ||
2801 zio_wait_for_children(zio
, ZIO_CHILD_DDT
, ZIO_WAIT_DONE
) ||
2802 zio_wait_for_children(zio
, ZIO_CHILD_LOGICAL
, ZIO_WAIT_DONE
))
2803 return (ZIO_PIPELINE_STOP
);
2805 for (c
= 0; c
< ZIO_CHILD_TYPES
; c
++)
2806 for (w
= 0; w
< ZIO_WAIT_TYPES
; w
++)
2807 ASSERT(zio
->io_children
[c
][w
] == 0);
2809 if (zio
->io_bp
!= NULL
) {
2810 ASSERT(zio
->io_bp
->blk_pad
[0] == 0);
2811 ASSERT(zio
->io_bp
->blk_pad
[1] == 0);
2812 ASSERT(bcmp(zio
->io_bp
, &zio
->io_bp_copy
, sizeof (blkptr_t
)) == 0 ||
2813 (zio
->io_bp
== zio_unique_parent(zio
)->io_bp
));
2814 if (zio
->io_type
== ZIO_TYPE_WRITE
&& !BP_IS_HOLE(zio
->io_bp
) &&
2815 zio
->io_bp_override
== NULL
&&
2816 !(zio
->io_flags
& ZIO_FLAG_IO_REPAIR
)) {
2817 ASSERT(!BP_SHOULD_BYTESWAP(zio
->io_bp
));
2818 ASSERT3U(zio
->io_prop
.zp_copies
, <=, BP_GET_NDVAS(zio
->io_bp
));
2819 ASSERT(BP_COUNT_GANG(zio
->io_bp
) == 0 ||
2820 (BP_COUNT_GANG(zio
->io_bp
) == BP_GET_NDVAS(zio
->io_bp
)));
2825 * If there were child vdev/gang/ddt errors, they apply to us now.
2827 zio_inherit_child_errors(zio
, ZIO_CHILD_VDEV
);
2828 zio_inherit_child_errors(zio
, ZIO_CHILD_GANG
);
2829 zio_inherit_child_errors(zio
, ZIO_CHILD_DDT
);
2832 * If the I/O on the transformed data was successful, generate any
2833 * checksum reports now while we still have the transformed data.
2835 if (zio
->io_error
== 0) {
2836 while (zio
->io_cksum_report
!= NULL
) {
2837 zio_cksum_report_t
*zcr
= zio
->io_cksum_report
;
2838 uint64_t align
= zcr
->zcr_align
;
2839 uint64_t asize
= P2ROUNDUP(zio
->io_size
, align
);
2840 char *abuf
= zio
->io_data
;
2842 if (asize
!= zio
->io_size
) {
2843 abuf
= zio_buf_alloc(asize
);
2844 bcopy(zio
->io_data
, abuf
, zio
->io_size
);
2845 bzero(abuf
+ zio
->io_size
, asize
- zio
->io_size
);
2848 zio
->io_cksum_report
= zcr
->zcr_next
;
2849 zcr
->zcr_next
= NULL
;
2850 zcr
->zcr_finish(zcr
, abuf
);
2851 zfs_ereport_free_checksum(zcr
);
2853 if (asize
!= zio
->io_size
)
2854 zio_buf_free(abuf
, asize
);
2858 zio_pop_transforms(zio
); /* note: may set zio->io_error */
2860 vdev_stat_update(zio
, zio
->io_size
);
2863 * If this I/O is attached to a particular vdev is slow, exeeding
2864 * 30 seconds to complete, post an error described the I/O delay.
2865 * We ignore these errors if the device is currently unavailable.
2867 if (zio
->io_delay
>= zio_delay_max
) {
2868 if (zio
->io_vd
!= NULL
&& !vdev_is_dead(zio
->io_vd
))
2869 zfs_ereport_post(FM_EREPORT_ZFS_DELAY
, zio
->io_spa
,
2870 zio
->io_vd
, zio
, 0, 0);
2873 if (zio
->io_error
) {
2875 * If this I/O is attached to a particular vdev,
2876 * generate an error message describing the I/O failure
2877 * at the block level. We ignore these errors if the
2878 * device is currently unavailable.
2880 if (zio
->io_error
!= ECKSUM
&& zio
->io_vd
!= NULL
&&
2881 !vdev_is_dead(zio
->io_vd
))
2882 zfs_ereport_post(FM_EREPORT_ZFS_IO
, zio
->io_spa
,
2883 zio
->io_vd
, zio
, 0, 0);
2885 if ((zio
->io_error
== EIO
|| !(zio
->io_flags
&
2886 (ZIO_FLAG_SPECULATIVE
| ZIO_FLAG_DONT_PROPAGATE
))) &&
2887 zio
== zio
->io_logical
) {
2889 * For logical I/O requests, tell the SPA to log the
2890 * error and generate a logical data ereport.
2892 spa_log_error(zio
->io_spa
, zio
);
2893 zfs_ereport_post(FM_EREPORT_ZFS_DATA
, zio
->io_spa
, NULL
, zio
,
2898 if (zio
->io_error
&& zio
== zio
->io_logical
) {
2900 * Determine whether zio should be reexecuted. This will
2901 * propagate all the way to the root via zio_notify_parent().
2903 ASSERT(zio
->io_vd
== NULL
&& zio
->io_bp
!= NULL
);
2904 ASSERT(zio
->io_child_type
== ZIO_CHILD_LOGICAL
);
2906 if (IO_IS_ALLOCATING(zio
) &&
2907 !(zio
->io_flags
& ZIO_FLAG_CANFAIL
)) {
2908 if (zio
->io_error
!= ENOSPC
)
2909 zio
->io_reexecute
|= ZIO_REEXECUTE_NOW
;
2911 zio
->io_reexecute
|= ZIO_REEXECUTE_SUSPEND
;
2914 if ((zio
->io_type
== ZIO_TYPE_READ
||
2915 zio
->io_type
== ZIO_TYPE_FREE
) &&
2916 !(zio
->io_flags
& ZIO_FLAG_SCAN_THREAD
) &&
2917 zio
->io_error
== ENXIO
&&
2918 spa_load_state(zio
->io_spa
) == SPA_LOAD_NONE
&&
2919 spa_get_failmode(zio
->io_spa
) != ZIO_FAILURE_MODE_CONTINUE
)
2920 zio
->io_reexecute
|= ZIO_REEXECUTE_SUSPEND
;
2922 if (!(zio
->io_flags
& ZIO_FLAG_CANFAIL
) && !zio
->io_reexecute
)
2923 zio
->io_reexecute
|= ZIO_REEXECUTE_SUSPEND
;
2926 * Here is a possibly good place to attempt to do
2927 * either combinatorial reconstruction or error correction
2928 * based on checksums. It also might be a good place
2929 * to send out preliminary ereports before we suspend
2935 * If there were logical child errors, they apply to us now.
2936 * We defer this until now to avoid conflating logical child
2937 * errors with errors that happened to the zio itself when
2938 * updating vdev stats and reporting FMA events above.
2940 zio_inherit_child_errors(zio
, ZIO_CHILD_LOGICAL
);
2942 if ((zio
->io_error
|| zio
->io_reexecute
) &&
2943 IO_IS_ALLOCATING(zio
) && zio
->io_gang_leader
== zio
&&
2944 !(zio
->io_flags
& ZIO_FLAG_IO_REWRITE
))
2945 zio_dva_unallocate(zio
, zio
->io_gang_tree
, zio
->io_bp
);
2947 zio_gang_tree_free(&zio
->io_gang_tree
);
2950 * Godfather I/Os should never suspend.
2952 if ((zio
->io_flags
& ZIO_FLAG_GODFATHER
) &&
2953 (zio
->io_reexecute
& ZIO_REEXECUTE_SUSPEND
))
2954 zio
->io_reexecute
= 0;
2956 if (zio
->io_reexecute
) {
2958 * This is a logical I/O that wants to reexecute.
2960 * Reexecute is top-down. When an i/o fails, if it's not
2961 * the root, it simply notifies its parent and sticks around.
2962 * The parent, seeing that it still has children in zio_done(),
2963 * does the same. This percolates all the way up to the root.
2964 * The root i/o will reexecute or suspend the entire tree.
2966 * This approach ensures that zio_reexecute() honors
2967 * all the original i/o dependency relationships, e.g.
2968 * parents not executing until children are ready.
2970 ASSERT(zio
->io_child_type
== ZIO_CHILD_LOGICAL
);
2972 zio
->io_gang_leader
= NULL
;
2974 mutex_enter(&zio
->io_lock
);
2975 zio
->io_state
[ZIO_WAIT_DONE
] = 1;
2976 mutex_exit(&zio
->io_lock
);
2979 * "The Godfather" I/O monitors its children but is
2980 * not a true parent to them. It will track them through
2981 * the pipeline but severs its ties whenever they get into
2982 * trouble (e.g. suspended). This allows "The Godfather"
2983 * I/O to return status without blocking.
2985 for (pio
= zio_walk_parents(zio
); pio
!= NULL
; pio
= pio_next
) {
2986 zio_link_t
*zl
= zio
->io_walk_link
;
2987 pio_next
= zio_walk_parents(zio
);
2989 if ((pio
->io_flags
& ZIO_FLAG_GODFATHER
) &&
2990 (zio
->io_reexecute
& ZIO_REEXECUTE_SUSPEND
)) {
2991 zio_remove_child(pio
, zio
, zl
);
2992 zio_notify_parent(pio
, zio
, ZIO_WAIT_DONE
);
2996 if ((pio
= zio_unique_parent(zio
)) != NULL
) {
2998 * We're not a root i/o, so there's nothing to do
2999 * but notify our parent. Don't propagate errors
3000 * upward since we haven't permanently failed yet.
3002 ASSERT(!(zio
->io_flags
& ZIO_FLAG_GODFATHER
));
3003 zio
->io_flags
|= ZIO_FLAG_DONT_PROPAGATE
;
3004 zio_notify_parent(pio
, zio
, ZIO_WAIT_DONE
);
3005 } else if (zio
->io_reexecute
& ZIO_REEXECUTE_SUSPEND
) {
3007 * We'd fail again if we reexecuted now, so suspend
3008 * until conditions improve (e.g. device comes online).
3010 zio_suspend(zio
->io_spa
, zio
);
3013 * Reexecution is potentially a huge amount of work.
3014 * Hand it off to the otherwise-unused claim taskq.
3016 ASSERT(taskq_empty_ent(&zio
->io_tqent
));
3017 (void) taskq_dispatch_ent(
3018 zio
->io_spa
->spa_zio_taskq
[ZIO_TYPE_CLAIM
][ZIO_TASKQ_ISSUE
],
3019 (task_func_t
*)zio_reexecute
, zio
, 0,
3022 return (ZIO_PIPELINE_STOP
);
3025 ASSERT(zio
->io_child_count
== 0);
3026 ASSERT(zio
->io_reexecute
== 0);
3027 ASSERT(zio
->io_error
== 0 || (zio
->io_flags
& ZIO_FLAG_CANFAIL
));
3030 * Report any checksum errors, since the I/O is complete.
3032 while (zio
->io_cksum_report
!= NULL
) {
3033 zio_cksum_report_t
*zcr
= zio
->io_cksum_report
;
3034 zio
->io_cksum_report
= zcr
->zcr_next
;
3035 zcr
->zcr_next
= NULL
;
3036 zcr
->zcr_finish(zcr
, NULL
);
3037 zfs_ereport_free_checksum(zcr
);
3041 * It is the responsibility of the done callback to ensure that this
3042 * particular zio is no longer discoverable for adoption, and as
3043 * such, cannot acquire any new parents.
3048 mutex_enter(&zio
->io_lock
);
3049 zio
->io_state
[ZIO_WAIT_DONE
] = 1;
3050 mutex_exit(&zio
->io_lock
);
3052 for (pio
= zio_walk_parents(zio
); pio
!= NULL
; pio
= pio_next
) {
3053 zio_link_t
*zl
= zio
->io_walk_link
;
3054 pio_next
= zio_walk_parents(zio
);
3055 zio_remove_child(pio
, zio
, zl
);
3056 zio_notify_parent(pio
, zio
, ZIO_WAIT_DONE
);
3059 if (zio
->io_waiter
!= NULL
) {
3060 mutex_enter(&zio
->io_lock
);
3061 zio
->io_executor
= NULL
;
3062 cv_broadcast(&zio
->io_cv
);
3063 mutex_exit(&zio
->io_lock
);
3068 return (ZIO_PIPELINE_STOP
);
3072 * ==========================================================================
3073 * I/O pipeline definition
3074 * ==========================================================================
3076 static zio_pipe_stage_t
*zio_pipeline
[] = {
3082 zio_checksum_generate
,
3096 zio_checksum_verify
,
3100 #if defined(_KERNEL) && defined(HAVE_SPL)
3101 /* Fault injection */
3102 EXPORT_SYMBOL(zio_injection_enabled
);
3103 EXPORT_SYMBOL(zio_inject_fault
);
3104 EXPORT_SYMBOL(zio_inject_list_next
);
3105 EXPORT_SYMBOL(zio_clear_fault
);
3106 EXPORT_SYMBOL(zio_handle_fault_injection
);
3107 EXPORT_SYMBOL(zio_handle_device_injection
);
3108 EXPORT_SYMBOL(zio_handle_label_injection
);
3109 EXPORT_SYMBOL(zio_priority_table
);
3110 EXPORT_SYMBOL(zio_type_name
);
3112 module_param(zio_bulk_flags
, int, 0644);
3113 MODULE_PARM_DESC(zio_bulk_flags
, "Additional flags to pass to bulk buffers");
3115 module_param(zio_delay_max
, int, 0644);
3116 MODULE_PARM_DESC(zio_delay_max
, "Max zio millisec delay before posting event");
3118 module_param(zio_requeue_io_start_cut_in_line
, int, 0644);
3119 MODULE_PARM_DESC(zio_requeue_io_start_cut_in_line
, "Prioritize requeued I/O");