4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2011, 2017 by Delphix. All rights reserved.
24 * Copyright (c) 2014 Integros [integros.com]
27 /* Portions Copyright 2010 Robert Milkowski */
29 #include <sys/zfs_context.h>
35 #include <sys/resource.h>
37 #include <sys/zil_impl.h>
38 #include <sys/dsl_dataset.h>
39 #include <sys/vdev_impl.h>
40 #include <sys/dmu_tx.h>
41 #include <sys/dsl_pool.h>
45 * The ZFS Intent Log (ZIL) saves "transaction records" (itxs) of system
46 * calls that change the file system. Each itx has enough information to
47 * be able to replay them after a system crash, power loss, or
48 * equivalent failure mode. These are stored in memory until either:
50 * 1. they are committed to the pool by the DMU transaction group
51 * (txg), at which point they can be discarded; or
52 * 2. they are committed to the on-disk ZIL for the dataset being
53 * modified (e.g. due to an fsync, O_DSYNC, or other synchronous
56 * In the event of a crash or power loss, the itxs contained by each
57 * dataset's on-disk ZIL will be replayed when that dataset is first
58 * instantianted (e.g. if the dataset is a normal fileystem, when it is
61 * As hinted at above, there is one ZIL per dataset (both the in-memory
62 * representation, and the on-disk representation). The on-disk format
63 * consists of 3 parts:
65 * - a single, per-dataset, ZIL header; which points to a chain of
66 * - zero or more ZIL blocks; each of which contains
67 * - zero or more ZIL records
69 * A ZIL record holds the information necessary to replay a single
70 * system call transaction. A ZIL block can hold many ZIL records, and
71 * the blocks are chained together, similarly to a singly linked list.
73 * Each ZIL block contains a block pointer (blkptr_t) to the next ZIL
74 * block in the chain, and the ZIL header points to the first block in
77 * Note, there is not a fixed place in the pool to hold these ZIL
78 * blocks; they are dynamically allocated and freed as needed from the
79 * blocks available on the pool, though they can be preferentially
80 * allocated from a dedicated "log" vdev.
84 * This controls the amount of time that a ZIL block (lwb) will remain
85 * "open" when it isn't "full", and it has a thread waiting for it to be
86 * committed to stable storage. Please refer to the zil_commit_waiter()
87 * function (and the comments within it) for more details.
89 int zfs_commit_timeout_pct
= 5;
92 * Disable intent logging replay. This global ZIL switch affects all pools.
94 int zil_replay_disable
= 0;
97 * Tunable parameter for debugging or performance analysis. Setting
98 * zfs_nocacheflush will cause corruption on power loss if a volatile
99 * out-of-order write cache is enabled.
101 boolean_t zfs_nocacheflush
= B_FALSE
;
104 * Limit SLOG write size per commit executed with synchronous priority.
105 * Any writes above that will be executed with lower (asynchronous) priority
106 * to limit potential SLOG device abuse by single active ZIL writer.
108 uint64_t zil_slog_bulk
= 768 * 1024;
110 static kmem_cache_t
*zil_lwb_cache
;
111 static kmem_cache_t
*zil_zcw_cache
;
113 static void zil_async_to_sync(zilog_t
*zilog
, uint64_t foid
);
115 #define LWB_EMPTY(lwb) ((BP_GET_LSIZE(&lwb->lwb_blk) - \
116 sizeof (zil_chain_t)) == (lwb->lwb_sz - lwb->lwb_nused))
119 zil_bp_compare(const void *x1
, const void *x2
)
121 const dva_t
*dva1
= &((zil_bp_node_t
*)x1
)->zn_dva
;
122 const dva_t
*dva2
= &((zil_bp_node_t
*)x2
)->zn_dva
;
124 if (DVA_GET_VDEV(dva1
) < DVA_GET_VDEV(dva2
))
126 if (DVA_GET_VDEV(dva1
) > DVA_GET_VDEV(dva2
))
129 if (DVA_GET_OFFSET(dva1
) < DVA_GET_OFFSET(dva2
))
131 if (DVA_GET_OFFSET(dva1
) > DVA_GET_OFFSET(dva2
))
138 zil_bp_tree_init(zilog_t
*zilog
)
140 avl_create(&zilog
->zl_bp_tree
, zil_bp_compare
,
141 sizeof (zil_bp_node_t
), offsetof(zil_bp_node_t
, zn_node
));
145 zil_bp_tree_fini(zilog_t
*zilog
)
147 avl_tree_t
*t
= &zilog
->zl_bp_tree
;
151 while ((zn
= avl_destroy_nodes(t
, &cookie
)) != NULL
)
152 kmem_free(zn
, sizeof (zil_bp_node_t
));
158 zil_bp_tree_add(zilog_t
*zilog
, const blkptr_t
*bp
)
160 avl_tree_t
*t
= &zilog
->zl_bp_tree
;
165 if (BP_IS_EMBEDDED(bp
))
168 dva
= BP_IDENTITY(bp
);
170 if (avl_find(t
, dva
, &where
) != NULL
)
171 return (SET_ERROR(EEXIST
));
173 zn
= kmem_alloc(sizeof (zil_bp_node_t
), KM_SLEEP
);
175 avl_insert(t
, zn
, where
);
180 static zil_header_t
*
181 zil_header_in_syncing_context(zilog_t
*zilog
)
183 return ((zil_header_t
*)zilog
->zl_header
);
187 zil_init_log_chain(zilog_t
*zilog
, blkptr_t
*bp
)
189 zio_cksum_t
*zc
= &bp
->blk_cksum
;
191 zc
->zc_word
[ZIL_ZC_GUID_0
] = spa_get_random(-1ULL);
192 zc
->zc_word
[ZIL_ZC_GUID_1
] = spa_get_random(-1ULL);
193 zc
->zc_word
[ZIL_ZC_OBJSET
] = dmu_objset_id(zilog
->zl_os
);
194 zc
->zc_word
[ZIL_ZC_SEQ
] = 1ULL;
198 * Read a log block and make sure it's valid.
201 zil_read_log_block(zilog_t
*zilog
, const blkptr_t
*bp
, blkptr_t
*nbp
, void *dst
,
204 enum zio_flag zio_flags
= ZIO_FLAG_CANFAIL
;
205 arc_flags_t aflags
= ARC_FLAG_WAIT
;
206 arc_buf_t
*abuf
= NULL
;
210 if (zilog
->zl_header
->zh_claim_txg
== 0)
211 zio_flags
|= ZIO_FLAG_SPECULATIVE
| ZIO_FLAG_SCRUB
;
213 if (!(zilog
->zl_header
->zh_flags
& ZIL_CLAIM_LR_SEQ_VALID
))
214 zio_flags
|= ZIO_FLAG_SPECULATIVE
;
216 SET_BOOKMARK(&zb
, bp
->blk_cksum
.zc_word
[ZIL_ZC_OBJSET
],
217 ZB_ZIL_OBJECT
, ZB_ZIL_LEVEL
, bp
->blk_cksum
.zc_word
[ZIL_ZC_SEQ
]);
219 error
= arc_read(NULL
, zilog
->zl_spa
, bp
, arc_getbuf_func
, &abuf
,
220 ZIO_PRIORITY_SYNC_READ
, zio_flags
, &aflags
, &zb
);
223 zio_cksum_t cksum
= bp
->blk_cksum
;
226 * Validate the checksummed log block.
228 * Sequence numbers should be... sequential. The checksum
229 * verifier for the next block should be bp's checksum plus 1.
231 * Also check the log chain linkage and size used.
233 cksum
.zc_word
[ZIL_ZC_SEQ
]++;
235 if (BP_GET_CHECKSUM(bp
) == ZIO_CHECKSUM_ZILOG2
) {
236 zil_chain_t
*zilc
= abuf
->b_data
;
237 char *lr
= (char *)(zilc
+ 1);
238 uint64_t len
= zilc
->zc_nused
- sizeof (zil_chain_t
);
240 if (bcmp(&cksum
, &zilc
->zc_next_blk
.blk_cksum
,
241 sizeof (cksum
)) || BP_IS_HOLE(&zilc
->zc_next_blk
)) {
242 error
= SET_ERROR(ECKSUM
);
244 ASSERT3U(len
, <=, SPA_OLD_MAXBLOCKSIZE
);
246 *end
= (char *)dst
+ len
;
247 *nbp
= zilc
->zc_next_blk
;
250 char *lr
= abuf
->b_data
;
251 uint64_t size
= BP_GET_LSIZE(bp
);
252 zil_chain_t
*zilc
= (zil_chain_t
*)(lr
+ size
) - 1;
254 if (bcmp(&cksum
, &zilc
->zc_next_blk
.blk_cksum
,
255 sizeof (cksum
)) || BP_IS_HOLE(&zilc
->zc_next_blk
) ||
256 (zilc
->zc_nused
> (size
- sizeof (*zilc
)))) {
257 error
= SET_ERROR(ECKSUM
);
259 ASSERT3U(zilc
->zc_nused
, <=,
260 SPA_OLD_MAXBLOCKSIZE
);
261 bcopy(lr
, dst
, zilc
->zc_nused
);
262 *end
= (char *)dst
+ zilc
->zc_nused
;
263 *nbp
= zilc
->zc_next_blk
;
267 arc_buf_destroy(abuf
, &abuf
);
274 * Read a TX_WRITE log data block.
277 zil_read_log_data(zilog_t
*zilog
, const lr_write_t
*lr
, void *wbuf
)
279 enum zio_flag zio_flags
= ZIO_FLAG_CANFAIL
;
280 const blkptr_t
*bp
= &lr
->lr_blkptr
;
281 arc_flags_t aflags
= ARC_FLAG_WAIT
;
282 arc_buf_t
*abuf
= NULL
;
286 if (BP_IS_HOLE(bp
)) {
288 bzero(wbuf
, MAX(BP_GET_LSIZE(bp
), lr
->lr_length
));
292 if (zilog
->zl_header
->zh_claim_txg
== 0)
293 zio_flags
|= ZIO_FLAG_SPECULATIVE
| ZIO_FLAG_SCRUB
;
295 SET_BOOKMARK(&zb
, dmu_objset_id(zilog
->zl_os
), lr
->lr_foid
,
296 ZB_ZIL_LEVEL
, lr
->lr_offset
/ BP_GET_LSIZE(bp
));
298 error
= arc_read(NULL
, zilog
->zl_spa
, bp
, arc_getbuf_func
, &abuf
,
299 ZIO_PRIORITY_SYNC_READ
, zio_flags
, &aflags
, &zb
);
303 bcopy(abuf
->b_data
, wbuf
, arc_buf_size(abuf
));
304 arc_buf_destroy(abuf
, &abuf
);
311 * Parse the intent log, and call parse_func for each valid record within.
314 zil_parse(zilog_t
*zilog
, zil_parse_blk_func_t
*parse_blk_func
,
315 zil_parse_lr_func_t
*parse_lr_func
, void *arg
, uint64_t txg
)
317 const zil_header_t
*zh
= zilog
->zl_header
;
318 boolean_t claimed
= !!zh
->zh_claim_txg
;
319 uint64_t claim_blk_seq
= claimed
? zh
->zh_claim_blk_seq
: UINT64_MAX
;
320 uint64_t claim_lr_seq
= claimed
? zh
->zh_claim_lr_seq
: UINT64_MAX
;
321 uint64_t max_blk_seq
= 0;
322 uint64_t max_lr_seq
= 0;
323 uint64_t blk_count
= 0;
324 uint64_t lr_count
= 0;
325 blkptr_t blk
, next_blk
;
330 * Old logs didn't record the maximum zh_claim_lr_seq.
332 if (!(zh
->zh_flags
& ZIL_CLAIM_LR_SEQ_VALID
))
333 claim_lr_seq
= UINT64_MAX
;
336 * Starting at the block pointed to by zh_log we read the log chain.
337 * For each block in the chain we strongly check that block to
338 * ensure its validity. We stop when an invalid block is found.
339 * For each block pointer in the chain we call parse_blk_func().
340 * For each record in each valid block we call parse_lr_func().
341 * If the log has been claimed, stop if we encounter a sequence
342 * number greater than the highest claimed sequence number.
344 lrbuf
= zio_buf_alloc(SPA_OLD_MAXBLOCKSIZE
);
345 zil_bp_tree_init(zilog
);
347 for (blk
= zh
->zh_log
; !BP_IS_HOLE(&blk
); blk
= next_blk
) {
348 uint64_t blk_seq
= blk
.blk_cksum
.zc_word
[ZIL_ZC_SEQ
];
352 if (blk_seq
> claim_blk_seq
)
354 if ((error
= parse_blk_func(zilog
, &blk
, arg
, txg
)) != 0)
356 ASSERT3U(max_blk_seq
, <, blk_seq
);
357 max_blk_seq
= blk_seq
;
360 if (max_lr_seq
== claim_lr_seq
&& max_blk_seq
== claim_blk_seq
)
363 error
= zil_read_log_block(zilog
, &blk
, &next_blk
, lrbuf
, &end
);
367 for (lrp
= lrbuf
; lrp
< end
; lrp
+= reclen
) {
368 lr_t
*lr
= (lr_t
*)lrp
;
369 reclen
= lr
->lrc_reclen
;
370 ASSERT3U(reclen
, >=, sizeof (lr_t
));
371 if (lr
->lrc_seq
> claim_lr_seq
)
373 if ((error
= parse_lr_func(zilog
, lr
, arg
, txg
)) != 0)
375 ASSERT3U(max_lr_seq
, <, lr
->lrc_seq
);
376 max_lr_seq
= lr
->lrc_seq
;
381 zilog
->zl_parse_error
= error
;
382 zilog
->zl_parse_blk_seq
= max_blk_seq
;
383 zilog
->zl_parse_lr_seq
= max_lr_seq
;
384 zilog
->zl_parse_blk_count
= blk_count
;
385 zilog
->zl_parse_lr_count
= lr_count
;
387 ASSERT(!claimed
|| !(zh
->zh_flags
& ZIL_CLAIM_LR_SEQ_VALID
) ||
388 (max_blk_seq
== claim_blk_seq
&& max_lr_seq
== claim_lr_seq
));
390 zil_bp_tree_fini(zilog
);
391 zio_buf_free(lrbuf
, SPA_OLD_MAXBLOCKSIZE
);
397 zil_claim_log_block(zilog_t
*zilog
, blkptr_t
*bp
, void *tx
, uint64_t first_txg
)
400 * Claim log block if not already committed and not already claimed.
401 * If tx == NULL, just verify that the block is claimable.
403 if (BP_IS_HOLE(bp
) || bp
->blk_birth
< first_txg
||
404 zil_bp_tree_add(zilog
, bp
) != 0)
407 return (zio_wait(zio_claim(NULL
, zilog
->zl_spa
,
408 tx
== NULL
? 0 : first_txg
, bp
, spa_claim_notify
, NULL
,
409 ZIO_FLAG_CANFAIL
| ZIO_FLAG_SPECULATIVE
| ZIO_FLAG_SCRUB
)));
413 zil_claim_log_record(zilog_t
*zilog
, lr_t
*lrc
, void *tx
, uint64_t first_txg
)
415 lr_write_t
*lr
= (lr_write_t
*)lrc
;
418 if (lrc
->lrc_txtype
!= TX_WRITE
)
422 * If the block is not readable, don't claim it. This can happen
423 * in normal operation when a log block is written to disk before
424 * some of the dmu_sync() blocks it points to. In this case, the
425 * transaction cannot have been committed to anyone (we would have
426 * waited for all writes to be stable first), so it is semantically
427 * correct to declare this the end of the log.
429 if (lr
->lr_blkptr
.blk_birth
>= first_txg
&&
430 (error
= zil_read_log_data(zilog
, lr
, NULL
)) != 0)
432 return (zil_claim_log_block(zilog
, &lr
->lr_blkptr
, tx
, first_txg
));
437 zil_free_log_block(zilog_t
*zilog
, blkptr_t
*bp
, void *tx
, uint64_t claim_txg
)
439 zio_free_zil(zilog
->zl_spa
, dmu_tx_get_txg(tx
), bp
);
445 zil_free_log_record(zilog_t
*zilog
, lr_t
*lrc
, void *tx
, uint64_t claim_txg
)
447 lr_write_t
*lr
= (lr_write_t
*)lrc
;
448 blkptr_t
*bp
= &lr
->lr_blkptr
;
451 * If we previously claimed it, we need to free it.
453 if (claim_txg
!= 0 && lrc
->lrc_txtype
== TX_WRITE
&&
454 bp
->blk_birth
>= claim_txg
&& zil_bp_tree_add(zilog
, bp
) == 0 &&
456 zio_free(zilog
->zl_spa
, dmu_tx_get_txg(tx
), bp
);
462 zil_lwb_vdev_compare(const void *x1
, const void *x2
)
464 const uint64_t v1
= ((zil_vdev_node_t
*)x1
)->zv_vdev
;
465 const uint64_t v2
= ((zil_vdev_node_t
*)x2
)->zv_vdev
;
476 zil_alloc_lwb(zilog_t
*zilog
, blkptr_t
*bp
, boolean_t slog
, uint64_t txg
)
480 lwb
= kmem_cache_alloc(zil_lwb_cache
, KM_SLEEP
);
481 lwb
->lwb_zilog
= zilog
;
483 lwb
->lwb_slog
= slog
;
484 lwb
->lwb_state
= LWB_STATE_CLOSED
;
485 lwb
->lwb_buf
= zio_buf_alloc(BP_GET_LSIZE(bp
));
486 lwb
->lwb_max_txg
= txg
;
487 lwb
->lwb_write_zio
= NULL
;
488 lwb
->lwb_root_zio
= NULL
;
490 lwb
->lwb_issued_timestamp
= 0;
491 if (BP_GET_CHECKSUM(bp
) == ZIO_CHECKSUM_ZILOG2
) {
492 lwb
->lwb_nused
= sizeof (zil_chain_t
);
493 lwb
->lwb_sz
= BP_GET_LSIZE(bp
);
496 lwb
->lwb_sz
= BP_GET_LSIZE(bp
) - sizeof (zil_chain_t
);
499 mutex_enter(&zilog
->zl_lock
);
500 list_insert_tail(&zilog
->zl_lwb_list
, lwb
);
501 mutex_exit(&zilog
->zl_lock
);
503 ASSERT(!MUTEX_HELD(&lwb
->lwb_vdev_lock
));
504 ASSERT(avl_is_empty(&lwb
->lwb_vdev_tree
));
505 VERIFY(list_is_empty(&lwb
->lwb_waiters
));
511 zil_free_lwb(zilog_t
*zilog
, lwb_t
*lwb
)
513 ASSERT(MUTEX_HELD(&zilog
->zl_lock
));
514 ASSERT(!MUTEX_HELD(&lwb
->lwb_vdev_lock
));
515 VERIFY(list_is_empty(&lwb
->lwb_waiters
));
516 ASSERT(avl_is_empty(&lwb
->lwb_vdev_tree
));
517 ASSERT3P(lwb
->lwb_write_zio
, ==, NULL
);
518 ASSERT3P(lwb
->lwb_root_zio
, ==, NULL
);
519 ASSERT3U(lwb
->lwb_max_txg
, <=, spa_syncing_txg(zilog
->zl_spa
));
520 ASSERT(lwb
->lwb_state
== LWB_STATE_CLOSED
||
521 lwb
->lwb_state
== LWB_STATE_DONE
);
524 * Clear the zilog's field to indicate this lwb is no longer
525 * valid, and prevent use-after-free errors.
527 if (zilog
->zl_last_lwb_opened
== lwb
)
528 zilog
->zl_last_lwb_opened
= NULL
;
530 kmem_cache_free(zil_lwb_cache
, lwb
);
534 * Called when we create in-memory log transactions so that we know
535 * to cleanup the itxs at the end of spa_sync().
538 zilog_dirty(zilog_t
*zilog
, uint64_t txg
)
540 dsl_pool_t
*dp
= zilog
->zl_dmu_pool
;
541 dsl_dataset_t
*ds
= dmu_objset_ds(zilog
->zl_os
);
543 ASSERT(spa_writeable(zilog
->zl_spa
));
545 if (ds
->ds_is_snapshot
)
546 panic("dirtying snapshot!");
548 if (txg_list_add(&dp
->dp_dirty_zilogs
, zilog
, txg
)) {
549 /* up the hold count until we can be written out */
550 dmu_buf_add_ref(ds
->ds_dbuf
, zilog
);
552 zilog
->zl_dirty_max_txg
= MAX(txg
, zilog
->zl_dirty_max_txg
);
557 * Determine if the zil is dirty in the specified txg. Callers wanting to
558 * ensure that the dirty state does not change must hold the itxg_lock for
559 * the specified txg. Holding the lock will ensure that the zil cannot be
560 * dirtied (zil_itx_assign) or cleaned (zil_clean) while we check its current
564 zilog_is_dirty_in_txg(zilog_t
*zilog
, uint64_t txg
)
566 dsl_pool_t
*dp
= zilog
->zl_dmu_pool
;
568 if (txg_list_member(&dp
->dp_dirty_zilogs
, zilog
, txg
& TXG_MASK
))
574 * Determine if the zil is dirty. The zil is considered dirty if it has
575 * any pending itx records that have not been cleaned by zil_clean().
578 zilog_is_dirty(zilog_t
*zilog
)
580 dsl_pool_t
*dp
= zilog
->zl_dmu_pool
;
582 for (int t
= 0; t
< TXG_SIZE
; t
++) {
583 if (txg_list_member(&dp
->dp_dirty_zilogs
, zilog
, t
))
590 * Create an on-disk intent log.
593 zil_create(zilog_t
*zilog
)
595 const zil_header_t
*zh
= zilog
->zl_header
;
601 boolean_t slog
= FALSE
;
604 * Wait for any previous destroy to complete.
606 txg_wait_synced(zilog
->zl_dmu_pool
, zilog
->zl_destroy_txg
);
608 ASSERT(zh
->zh_claim_txg
== 0);
609 ASSERT(zh
->zh_replay_seq
== 0);
614 * Allocate an initial log block if:
615 * - there isn't one already
616 * - the existing block is the wrong endianess
618 if (BP_IS_HOLE(&blk
) || BP_SHOULD_BYTESWAP(&blk
)) {
619 tx
= dmu_tx_create(zilog
->zl_os
);
620 VERIFY0(dmu_tx_assign(tx
, TXG_WAIT
));
621 dsl_dataset_dirty(dmu_objset_ds(zilog
->zl_os
), tx
);
622 txg
= dmu_tx_get_txg(tx
);
624 if (!BP_IS_HOLE(&blk
)) {
625 zio_free_zil(zilog
->zl_spa
, txg
, &blk
);
629 error
= zio_alloc_zil(zilog
->zl_spa
, txg
, &blk
, NULL
,
630 ZIL_MIN_BLKSZ
, &slog
);
633 zil_init_log_chain(zilog
, &blk
);
637 * Allocate a log write block (lwb) for the first log block.
640 lwb
= zil_alloc_lwb(zilog
, &blk
, slog
, txg
);
643 * If we just allocated the first log block, commit our transaction
644 * and wait for zil_sync() to stuff the block poiner into zh_log.
645 * (zh is part of the MOS, so we cannot modify it in open context.)
649 txg_wait_synced(zilog
->zl_dmu_pool
, txg
);
652 ASSERT(bcmp(&blk
, &zh
->zh_log
, sizeof (blk
)) == 0);
658 * In one tx, free all log blocks and clear the log header. If keep_first
659 * is set, then we're replaying a log with no content. We want to keep the
660 * first block, however, so that the first synchronous transaction doesn't
661 * require a txg_wait_synced() in zil_create(). We don't need to
662 * txg_wait_synced() here either when keep_first is set, because both
663 * zil_create() and zil_destroy() will wait for any in-progress destroys
667 zil_destroy(zilog_t
*zilog
, boolean_t keep_first
)
669 const zil_header_t
*zh
= zilog
->zl_header
;
675 * Wait for any previous destroy to complete.
677 txg_wait_synced(zilog
->zl_dmu_pool
, zilog
->zl_destroy_txg
);
679 zilog
->zl_old_header
= *zh
; /* debugging aid */
681 if (BP_IS_HOLE(&zh
->zh_log
))
684 tx
= dmu_tx_create(zilog
->zl_os
);
685 VERIFY0(dmu_tx_assign(tx
, TXG_WAIT
));
686 dsl_dataset_dirty(dmu_objset_ds(zilog
->zl_os
), tx
);
687 txg
= dmu_tx_get_txg(tx
);
689 mutex_enter(&zilog
->zl_lock
);
691 ASSERT3U(zilog
->zl_destroy_txg
, <, txg
);
692 zilog
->zl_destroy_txg
= txg
;
693 zilog
->zl_keep_first
= keep_first
;
695 if (!list_is_empty(&zilog
->zl_lwb_list
)) {
696 ASSERT(zh
->zh_claim_txg
== 0);
698 while ((lwb
= list_head(&zilog
->zl_lwb_list
)) != NULL
) {
699 list_remove(&zilog
->zl_lwb_list
, lwb
);
700 if (lwb
->lwb_buf
!= NULL
)
701 zio_buf_free(lwb
->lwb_buf
, lwb
->lwb_sz
);
702 zio_free(zilog
->zl_spa
, txg
, &lwb
->lwb_blk
);
703 zil_free_lwb(zilog
, lwb
);
705 } else if (!keep_first
) {
706 zil_destroy_sync(zilog
, tx
);
708 mutex_exit(&zilog
->zl_lock
);
714 zil_destroy_sync(zilog_t
*zilog
, dmu_tx_t
*tx
)
716 ASSERT(list_is_empty(&zilog
->zl_lwb_list
));
717 (void) zil_parse(zilog
, zil_free_log_block
,
718 zil_free_log_record
, tx
, zilog
->zl_header
->zh_claim_txg
);
722 zil_claim(dsl_pool_t
*dp
, dsl_dataset_t
*ds
, void *txarg
)
724 dmu_tx_t
*tx
= txarg
;
725 uint64_t first_txg
= dmu_tx_get_txg(tx
);
731 error
= dmu_objset_own_obj(dp
, ds
->ds_object
,
732 DMU_OST_ANY
, B_FALSE
, FTAG
, &os
);
735 * EBUSY indicates that the objset is inconsistent, in which
736 * case it can not have a ZIL.
738 if (error
!= EBUSY
) {
739 cmn_err(CE_WARN
, "can't open objset for %llu, error %u",
740 (unsigned long long)ds
->ds_object
, error
);
745 zilog
= dmu_objset_zil(os
);
746 zh
= zil_header_in_syncing_context(zilog
);
748 if (spa_get_log_state(zilog
->zl_spa
) == SPA_LOG_CLEAR
) {
749 if (!BP_IS_HOLE(&zh
->zh_log
))
750 zio_free_zil(zilog
->zl_spa
, first_txg
, &zh
->zh_log
);
751 BP_ZERO(&zh
->zh_log
);
752 dsl_dataset_dirty(dmu_objset_ds(os
), tx
);
753 dmu_objset_disown(os
, FTAG
);
758 * Claim all log blocks if we haven't already done so, and remember
759 * the highest claimed sequence number. This ensures that if we can
760 * read only part of the log now (e.g. due to a missing device),
761 * but we can read the entire log later, we will not try to replay
762 * or destroy beyond the last block we successfully claimed.
764 ASSERT3U(zh
->zh_claim_txg
, <=, first_txg
);
765 if (zh
->zh_claim_txg
== 0 && !BP_IS_HOLE(&zh
->zh_log
)) {
766 (void) zil_parse(zilog
, zil_claim_log_block
,
767 zil_claim_log_record
, tx
, first_txg
);
768 zh
->zh_claim_txg
= first_txg
;
769 zh
->zh_claim_blk_seq
= zilog
->zl_parse_blk_seq
;
770 zh
->zh_claim_lr_seq
= zilog
->zl_parse_lr_seq
;
771 if (zilog
->zl_parse_lr_count
|| zilog
->zl_parse_blk_count
> 1)
772 zh
->zh_flags
|= ZIL_REPLAY_NEEDED
;
773 zh
->zh_flags
|= ZIL_CLAIM_LR_SEQ_VALID
;
774 dsl_dataset_dirty(dmu_objset_ds(os
), tx
);
777 ASSERT3U(first_txg
, ==, (spa_last_synced_txg(zilog
->zl_spa
) + 1));
778 dmu_objset_disown(os
, FTAG
);
783 * Check the log by walking the log chain.
784 * Checksum errors are ok as they indicate the end of the chain.
785 * Any other error (no device or read failure) returns an error.
789 zil_check_log_chain(dsl_pool_t
*dp
, dsl_dataset_t
*ds
, void *tx
)
798 error
= dmu_objset_from_ds(ds
, &os
);
800 cmn_err(CE_WARN
, "can't open objset %llu, error %d",
801 (unsigned long long)ds
->ds_object
, error
);
805 zilog
= dmu_objset_zil(os
);
806 bp
= (blkptr_t
*)&zilog
->zl_header
->zh_log
;
809 * Check the first block and determine if it's on a log device
810 * which may have been removed or faulted prior to loading this
811 * pool. If so, there's no point in checking the rest of the log
812 * as its content should have already been synced to the pool.
814 if (!BP_IS_HOLE(bp
)) {
816 boolean_t valid
= B_TRUE
;
818 spa_config_enter(os
->os_spa
, SCL_STATE
, FTAG
, RW_READER
);
819 vd
= vdev_lookup_top(os
->os_spa
, DVA_GET_VDEV(&bp
->blk_dva
[0]));
820 if (vd
->vdev_islog
&& vdev_is_dead(vd
))
821 valid
= vdev_log_state_valid(vd
);
822 spa_config_exit(os
->os_spa
, SCL_STATE
, FTAG
);
829 * Because tx == NULL, zil_claim_log_block() will not actually claim
830 * any blocks, but just determine whether it is possible to do so.
831 * In addition to checking the log chain, zil_claim_log_block()
832 * will invoke zio_claim() with a done func of spa_claim_notify(),
833 * which will update spa_max_claim_txg. See spa_load() for details.
835 error
= zil_parse(zilog
, zil_claim_log_block
, zil_claim_log_record
, tx
,
836 zilog
->zl_header
->zh_claim_txg
? -1ULL : spa_first_txg(os
->os_spa
));
838 return ((error
== ECKSUM
|| error
== ENOENT
) ? 0 : error
);
842 * When an itx is "skipped", this function is used to properly mark the
843 * waiter as "done, and signal any thread(s) waiting on it. An itx can
844 * be skipped (and not committed to an lwb) for a variety of reasons,
845 * one of them being that the itx was committed via spa_sync(), prior to
846 * it being committed to an lwb; this can happen if a thread calling
847 * zil_commit() is racing with spa_sync().
850 zil_commit_waiter_skip(zil_commit_waiter_t
*zcw
)
852 mutex_enter(&zcw
->zcw_lock
);
853 ASSERT3B(zcw
->zcw_done
, ==, B_FALSE
);
854 zcw
->zcw_done
= B_TRUE
;
855 cv_broadcast(&zcw
->zcw_cv
);
856 mutex_exit(&zcw
->zcw_lock
);
860 * This function is used when the given waiter is to be linked into an
861 * lwb's "lwb_waiter" list; i.e. when the itx is committed to the lwb.
862 * At this point, the waiter will no longer be referenced by the itx,
863 * and instead, will be referenced by the lwb.
866 zil_commit_waiter_link_lwb(zil_commit_waiter_t
*zcw
, lwb_t
*lwb
)
869 * The lwb_waiters field of the lwb is protected by the zilog's
870 * zl_lock, thus it must be held when calling this function.
872 ASSERT(MUTEX_HELD(&lwb
->lwb_zilog
->zl_lock
));
874 mutex_enter(&zcw
->zcw_lock
);
875 ASSERT(!list_link_active(&zcw
->zcw_node
));
876 ASSERT3P(zcw
->zcw_lwb
, ==, NULL
);
877 ASSERT3P(lwb
, !=, NULL
);
878 ASSERT(lwb
->lwb_state
== LWB_STATE_OPENED
||
879 lwb
->lwb_state
== LWB_STATE_ISSUED
);
881 list_insert_tail(&lwb
->lwb_waiters
, zcw
);
883 mutex_exit(&zcw
->zcw_lock
);
887 * This function is used when zio_alloc_zil() fails to allocate a ZIL
888 * block, and the given waiter must be linked to the "nolwb waiters"
889 * list inside of zil_process_commit_list().
892 zil_commit_waiter_link_nolwb(zil_commit_waiter_t
*zcw
, list_t
*nolwb
)
894 mutex_enter(&zcw
->zcw_lock
);
895 ASSERT(!list_link_active(&zcw
->zcw_node
));
896 ASSERT3P(zcw
->zcw_lwb
, ==, NULL
);
897 list_insert_tail(nolwb
, zcw
);
898 mutex_exit(&zcw
->zcw_lock
);
902 zil_lwb_add_block(lwb_t
*lwb
, const blkptr_t
*bp
)
904 avl_tree_t
*t
= &lwb
->lwb_vdev_tree
;
906 zil_vdev_node_t
*zv
, zvsearch
;
907 int ndvas
= BP_GET_NDVAS(bp
);
910 if (zfs_nocacheflush
)
913 mutex_enter(&lwb
->lwb_vdev_lock
);
914 for (i
= 0; i
< ndvas
; i
++) {
915 zvsearch
.zv_vdev
= DVA_GET_VDEV(&bp
->blk_dva
[i
]);
916 if (avl_find(t
, &zvsearch
, &where
) == NULL
) {
917 zv
= kmem_alloc(sizeof (*zv
), KM_SLEEP
);
918 zv
->zv_vdev
= zvsearch
.zv_vdev
;
919 avl_insert(t
, zv
, where
);
922 mutex_exit(&lwb
->lwb_vdev_lock
);
926 zil_lwb_add_txg(lwb_t
*lwb
, uint64_t txg
)
928 lwb
->lwb_max_txg
= MAX(lwb
->lwb_max_txg
, txg
);
932 * This function is a called after all VDEVs associated with a given lwb
933 * write have completed their DKIOCFLUSHWRITECACHE command; or as soon
934 * as the lwb write completes, if "zfs_nocacheflush" is set.
936 * The intention is for this function to be called as soon as the
937 * contents of an lwb are considered "stable" on disk, and will survive
938 * any sudden loss of power. At this point, any threads waiting for the
939 * lwb to reach this state are signalled, and the "waiter" structures
943 zil_lwb_flush_vdevs_done(zio_t
*zio
)
945 lwb_t
*lwb
= zio
->io_private
;
946 zilog_t
*zilog
= lwb
->lwb_zilog
;
947 dmu_tx_t
*tx
= lwb
->lwb_tx
;
948 zil_commit_waiter_t
*zcw
;
950 spa_config_exit(zilog
->zl_spa
, SCL_STATE
, lwb
);
952 zio_buf_free(lwb
->lwb_buf
, lwb
->lwb_sz
);
954 mutex_enter(&zilog
->zl_lock
);
957 * Ensure the lwb buffer pointer is cleared before releasing the
958 * txg. If we have had an allocation failure and the txg is
959 * waiting to sync then we want zil_sync() to remove the lwb so
960 * that it's not picked up as the next new one in
961 * zil_process_commit_list(). zil_sync() will only remove the
962 * lwb if lwb_buf is null.
967 ASSERT3U(lwb
->lwb_issued_timestamp
, >, 0);
968 zilog
->zl_last_lwb_latency
= gethrtime() - lwb
->lwb_issued_timestamp
;
970 lwb
->lwb_root_zio
= NULL
;
971 lwb
->lwb_state
= LWB_STATE_DONE
;
973 if (zilog
->zl_last_lwb_opened
== lwb
) {
975 * Remember the highest committed log sequence number
976 * for ztest. We only update this value when all the log
977 * writes succeeded, because ztest wants to ASSERT that
978 * it got the whole log chain.
980 zilog
->zl_commit_lr_seq
= zilog
->zl_lr_seq
;
983 while ((zcw
= list_head(&lwb
->lwb_waiters
)) != NULL
) {
984 mutex_enter(&zcw
->zcw_lock
);
986 ASSERT(list_link_active(&zcw
->zcw_node
));
987 list_remove(&lwb
->lwb_waiters
, zcw
);
989 ASSERT3P(zcw
->zcw_lwb
, ==, lwb
);
992 zcw
->zcw_zio_error
= zio
->io_error
;
994 ASSERT3B(zcw
->zcw_done
, ==, B_FALSE
);
995 zcw
->zcw_done
= B_TRUE
;
996 cv_broadcast(&zcw
->zcw_cv
);
998 mutex_exit(&zcw
->zcw_lock
);
1001 mutex_exit(&zilog
->zl_lock
);
1004 * Now that we've written this log block, we have a stable pointer
1005 * to the next block in the chain, so it's OK to let the txg in
1006 * which we allocated the next block sync.
1012 * This is called when an lwb write completes. This means, this specific
1013 * lwb was written to disk, and all dependent lwb have also been
1016 * At this point, a DKIOCFLUSHWRITECACHE command hasn't been issued to
1017 * the VDEVs involved in writing out this specific lwb. The lwb will be
1018 * "done" once zil_lwb_flush_vdevs_done() is called, which occurs in the
1019 * zio completion callback for the lwb's root zio.
1022 zil_lwb_write_done(zio_t
*zio
)
1024 lwb_t
*lwb
= zio
->io_private
;
1025 spa_t
*spa
= zio
->io_spa
;
1026 zilog_t
*zilog
= lwb
->lwb_zilog
;
1027 avl_tree_t
*t
= &lwb
->lwb_vdev_tree
;
1028 void *cookie
= NULL
;
1029 zil_vdev_node_t
*zv
;
1031 ASSERT3S(spa_config_held(spa
, SCL_STATE
, RW_READER
), !=, 0);
1033 ASSERT(BP_GET_COMPRESS(zio
->io_bp
) == ZIO_COMPRESS_OFF
);
1034 ASSERT(BP_GET_TYPE(zio
->io_bp
) == DMU_OT_INTENT_LOG
);
1035 ASSERT(BP_GET_LEVEL(zio
->io_bp
) == 0);
1036 ASSERT(BP_GET_BYTEORDER(zio
->io_bp
) == ZFS_HOST_BYTEORDER
);
1037 ASSERT(!BP_IS_GANG(zio
->io_bp
));
1038 ASSERT(!BP_IS_HOLE(zio
->io_bp
));
1039 ASSERT(BP_GET_FILL(zio
->io_bp
) == 0);
1041 abd_put(zio
->io_abd
);
1043 ASSERT3S(lwb
->lwb_state
, ==, LWB_STATE_ISSUED
);
1045 mutex_enter(&zilog
->zl_lock
);
1046 lwb
->lwb_write_zio
= NULL
;
1047 mutex_exit(&zilog
->zl_lock
);
1049 if (avl_numnodes(t
) == 0)
1053 * If there was an IO error, we're not going to call zio_flush()
1054 * on these vdevs, so we simply empty the tree and free the
1055 * nodes. We avoid calling zio_flush() since there isn't any
1056 * good reason for doing so, after the lwb block failed to be
1059 if (zio
->io_error
!= 0) {
1060 while ((zv
= avl_destroy_nodes(t
, &cookie
)) != NULL
)
1061 kmem_free(zv
, sizeof (*zv
));
1065 while ((zv
= avl_destroy_nodes(t
, &cookie
)) != NULL
) {
1066 vdev_t
*vd
= vdev_lookup_top(spa
, zv
->zv_vdev
);
1068 zio_flush(lwb
->lwb_root_zio
, vd
);
1069 kmem_free(zv
, sizeof (*zv
));
1074 * This function's purpose is to "open" an lwb such that it is ready to
1075 * accept new itxs being committed to it. To do this, the lwb's zio
1076 * structures are created, and linked to the lwb. This function is
1077 * idempotent; if the passed in lwb has already been opened, this
1078 * function is essentially a no-op.
1081 zil_lwb_write_open(zilog_t
*zilog
, lwb_t
*lwb
)
1083 zbookmark_phys_t zb
;
1084 zio_priority_t prio
;
1086 ASSERT(MUTEX_HELD(&zilog
->zl_issuer_lock
));
1087 ASSERT3P(lwb
, !=, NULL
);
1088 EQUIV(lwb
->lwb_root_zio
== NULL
, lwb
->lwb_state
== LWB_STATE_CLOSED
);
1089 EQUIV(lwb
->lwb_root_zio
!= NULL
, lwb
->lwb_state
== LWB_STATE_OPENED
);
1091 SET_BOOKMARK(&zb
, lwb
->lwb_blk
.blk_cksum
.zc_word
[ZIL_ZC_OBJSET
],
1092 ZB_ZIL_OBJECT
, ZB_ZIL_LEVEL
,
1093 lwb
->lwb_blk
.blk_cksum
.zc_word
[ZIL_ZC_SEQ
]);
1095 if (lwb
->lwb_root_zio
== NULL
) {
1096 abd_t
*lwb_abd
= abd_get_from_buf(lwb
->lwb_buf
,
1097 BP_GET_LSIZE(&lwb
->lwb_blk
));
1099 if (!lwb
->lwb_slog
|| zilog
->zl_cur_used
<= zil_slog_bulk
)
1100 prio
= ZIO_PRIORITY_SYNC_WRITE
;
1102 prio
= ZIO_PRIORITY_ASYNC_WRITE
;
1104 lwb
->lwb_root_zio
= zio_root(zilog
->zl_spa
,
1105 zil_lwb_flush_vdevs_done
, lwb
, ZIO_FLAG_CANFAIL
);
1106 ASSERT3P(lwb
->lwb_root_zio
, !=, NULL
);
1108 lwb
->lwb_write_zio
= zio_rewrite(lwb
->lwb_root_zio
,
1109 zilog
->zl_spa
, 0, &lwb
->lwb_blk
, lwb_abd
,
1110 BP_GET_LSIZE(&lwb
->lwb_blk
), zil_lwb_write_done
, lwb
,
1111 prio
, ZIO_FLAG_CANFAIL
| ZIO_FLAG_DONT_PROPAGATE
, &zb
);
1112 ASSERT3P(lwb
->lwb_write_zio
, !=, NULL
);
1114 lwb
->lwb_state
= LWB_STATE_OPENED
;
1116 mutex_enter(&zilog
->zl_lock
);
1119 * The zilog's "zl_last_lwb_opened" field is used to
1120 * build the lwb/zio dependency chain, which is used to
1121 * preserve the ordering of lwb completions that is
1122 * required by the semantics of the ZIL. Each new lwb
1123 * zio becomes a parent of the "previous" lwb zio, such
1124 * that the new lwb's zio cannot complete until the
1125 * "previous" lwb's zio completes.
1127 * This is required by the semantics of zil_commit();
1128 * the commit waiters attached to the lwbs will be woken
1129 * in the lwb zio's completion callback, so this zio
1130 * dependency graph ensures the waiters are woken in the
1131 * correct order (the same order the lwbs were created).
1133 lwb_t
*last_lwb_opened
= zilog
->zl_last_lwb_opened
;
1134 if (last_lwb_opened
!= NULL
&&
1135 last_lwb_opened
->lwb_state
!= LWB_STATE_DONE
) {
1136 ASSERT(last_lwb_opened
->lwb_state
== LWB_STATE_OPENED
||
1137 last_lwb_opened
->lwb_state
== LWB_STATE_ISSUED
);
1138 ASSERT3P(last_lwb_opened
->lwb_root_zio
, !=, NULL
);
1139 zio_add_child(lwb
->lwb_root_zio
,
1140 last_lwb_opened
->lwb_root_zio
);
1142 zilog
->zl_last_lwb_opened
= lwb
;
1144 mutex_exit(&zilog
->zl_lock
);
1147 ASSERT3P(lwb
->lwb_root_zio
, !=, NULL
);
1148 ASSERT3P(lwb
->lwb_write_zio
, !=, NULL
);
1149 ASSERT3S(lwb
->lwb_state
, ==, LWB_STATE_OPENED
);
1153 * Define a limited set of intent log block sizes.
1155 * These must be a multiple of 4KB. Note only the amount used (again
1156 * aligned to 4KB) actually gets written. However, we can't always just
1157 * allocate SPA_OLD_MAXBLOCKSIZE as the slog space could be exhausted.
1159 uint64_t zil_block_buckets
[] = {
1160 4096, /* non TX_WRITE */
1161 8192+4096, /* data base */
1162 32*1024 + 4096, /* NFS writes */
1167 * Start a log block write and advance to the next log block.
1168 * Calls are serialized.
1171 zil_lwb_write_issue(zilog_t
*zilog
, lwb_t
*lwb
)
1175 spa_t
*spa
= zilog
->zl_spa
;
1179 uint64_t zil_blksz
, wsz
;
1183 ASSERT(MUTEX_HELD(&zilog
->zl_issuer_lock
));
1184 ASSERT3P(lwb
->lwb_root_zio
, !=, NULL
);
1185 ASSERT3P(lwb
->lwb_write_zio
, !=, NULL
);
1186 ASSERT3S(lwb
->lwb_state
, ==, LWB_STATE_OPENED
);
1188 if (BP_GET_CHECKSUM(&lwb
->lwb_blk
) == ZIO_CHECKSUM_ZILOG2
) {
1189 zilc
= (zil_chain_t
*)lwb
->lwb_buf
;
1190 bp
= &zilc
->zc_next_blk
;
1192 zilc
= (zil_chain_t
*)(lwb
->lwb_buf
+ lwb
->lwb_sz
);
1193 bp
= &zilc
->zc_next_blk
;
1196 ASSERT(lwb
->lwb_nused
<= lwb
->lwb_sz
);
1199 * Allocate the next block and save its address in this block
1200 * before writing it in order to establish the log chain.
1201 * Note that if the allocation of nlwb synced before we wrote
1202 * the block that points at it (lwb), we'd leak it if we crashed.
1203 * Therefore, we don't do dmu_tx_commit() until zil_lwb_write_done().
1204 * We dirty the dataset to ensure that zil_sync() will be called
1205 * to clean up in the event of allocation failure or I/O failure.
1208 tx
= dmu_tx_create(zilog
->zl_os
);
1211 * Since we are not going to create any new dirty data and we can even
1212 * help with clearing the existing dirty data, we should not be subject
1213 * to the dirty data based delays.
1214 * We (ab)use TXG_WAITED to bypass the delay mechanism.
1215 * One side effect from using TXG_WAITED is that dmu_tx_assign() can
1216 * fail if the pool is suspended. Those are dramatic circumstances,
1217 * so we return NULL to signal that the normal ZIL processing is not
1218 * possible and txg_wait_synced() should be used to ensure that the data
1221 error
= dmu_tx_assign(tx
, TXG_WAITED
);
1223 ASSERT3S(error
, ==, EIO
);
1227 dsl_dataset_dirty(dmu_objset_ds(zilog
->zl_os
), tx
);
1228 txg
= dmu_tx_get_txg(tx
);
1233 * Log blocks are pre-allocated. Here we select the size of the next
1234 * block, based on size used in the last block.
1235 * - first find the smallest bucket that will fit the block from a
1236 * limited set of block sizes. This is because it's faster to write
1237 * blocks allocated from the same metaslab as they are adjacent or
1239 * - next find the maximum from the new suggested size and an array of
1240 * previous sizes. This lessens a picket fence effect of wrongly
1241 * guesssing the size if we have a stream of say 2k, 64k, 2k, 64k
1244 * Note we only write what is used, but we can't just allocate
1245 * the maximum block size because we can exhaust the available
1248 zil_blksz
= zilog
->zl_cur_used
+ sizeof (zil_chain_t
);
1249 for (i
= 0; zil_blksz
> zil_block_buckets
[i
]; i
++)
1251 zil_blksz
= zil_block_buckets
[i
];
1252 if (zil_blksz
== UINT64_MAX
)
1253 zil_blksz
= SPA_OLD_MAXBLOCKSIZE
;
1254 zilog
->zl_prev_blks
[zilog
->zl_prev_rotor
] = zil_blksz
;
1255 for (i
= 0; i
< ZIL_PREV_BLKS
; i
++)
1256 zil_blksz
= MAX(zil_blksz
, zilog
->zl_prev_blks
[i
]);
1257 zilog
->zl_prev_rotor
= (zilog
->zl_prev_rotor
+ 1) & (ZIL_PREV_BLKS
- 1);
1261 /* pass the old blkptr in order to spread log blocks across devs */
1262 error
= zio_alloc_zil(spa
, txg
, bp
, &lwb
->lwb_blk
, zil_blksz
, &slog
);
1264 ASSERT3U(bp
->blk_birth
, ==, txg
);
1265 bp
->blk_cksum
= lwb
->lwb_blk
.blk_cksum
;
1266 bp
->blk_cksum
.zc_word
[ZIL_ZC_SEQ
]++;
1269 * Allocate a new log write block (lwb).
1271 nlwb
= zil_alloc_lwb(zilog
, bp
, slog
, txg
);
1274 if (BP_GET_CHECKSUM(&lwb
->lwb_blk
) == ZIO_CHECKSUM_ZILOG2
) {
1275 /* For Slim ZIL only write what is used. */
1276 wsz
= P2ROUNDUP_TYPED(lwb
->lwb_nused
, ZIL_MIN_BLKSZ
, uint64_t);
1277 ASSERT3U(wsz
, <=, lwb
->lwb_sz
);
1278 zio_shrink(lwb
->lwb_write_zio
, wsz
);
1285 zilc
->zc_nused
= lwb
->lwb_nused
;
1286 zilc
->zc_eck
.zec_cksum
= lwb
->lwb_blk
.blk_cksum
;
1289 * clear unused data for security
1291 bzero(lwb
->lwb_buf
+ lwb
->lwb_nused
, wsz
- lwb
->lwb_nused
);
1293 spa_config_enter(zilog
->zl_spa
, SCL_STATE
, lwb
, RW_READER
);
1295 zil_lwb_add_block(lwb
, &lwb
->lwb_blk
);
1296 lwb
->lwb_issued_timestamp
= gethrtime();
1297 lwb
->lwb_state
= LWB_STATE_ISSUED
;
1299 zio_nowait(lwb
->lwb_root_zio
);
1300 zio_nowait(lwb
->lwb_write_zio
);
1303 * If there was an allocation failure then nlwb will be null which
1304 * forces a txg_wait_synced().
1310 zil_lwb_commit(zilog_t
*zilog
, itx_t
*itx
, lwb_t
*lwb
)
1313 lr_write_t
*lrwb
, *lrw
;
1315 uint64_t dlen
, dnow
, lwb_sp
, reclen
, txg
;
1317 ASSERT(MUTEX_HELD(&zilog
->zl_issuer_lock
));
1318 ASSERT3P(lwb
, !=, NULL
);
1319 ASSERT3P(lwb
->lwb_buf
, !=, NULL
);
1321 zil_lwb_write_open(zilog
, lwb
);
1324 lrw
= (lr_write_t
*)lrc
;
1327 * A commit itx doesn't represent any on-disk state; instead
1328 * it's simply used as a place holder on the commit list, and
1329 * provides a mechanism for attaching a "commit waiter" onto the
1330 * correct lwb (such that the waiter can be signalled upon
1331 * completion of that lwb). Thus, we don't process this itx's
1332 * log record if it's a commit itx (these itx's don't have log
1333 * records), and instead link the itx's waiter onto the lwb's
1336 * For more details, see the comment above zil_commit().
1338 if (lrc
->lrc_txtype
== TX_COMMIT
) {
1339 mutex_enter(&zilog
->zl_lock
);
1340 zil_commit_waiter_link_lwb(itx
->itx_private
, lwb
);
1341 itx
->itx_private
= NULL
;
1342 mutex_exit(&zilog
->zl_lock
);
1346 if (lrc
->lrc_txtype
== TX_WRITE
&& itx
->itx_wr_state
== WR_NEED_COPY
) {
1347 dlen
= P2ROUNDUP_TYPED(
1348 lrw
->lr_length
, sizeof (uint64_t), uint64_t);
1352 reclen
= lrc
->lrc_reclen
;
1353 zilog
->zl_cur_used
+= (reclen
+ dlen
);
1356 ASSERT3U(zilog
->zl_cur_used
, <, UINT64_MAX
- (reclen
+ dlen
));
1360 * If this record won't fit in the current log block, start a new one.
1361 * For WR_NEED_COPY optimize layout for minimal number of chunks.
1363 lwb_sp
= lwb
->lwb_sz
- lwb
->lwb_nused
;
1364 if (reclen
> lwb_sp
|| (reclen
+ dlen
> lwb_sp
&&
1365 lwb_sp
< ZIL_MAX_WASTE_SPACE
&& (dlen
% ZIL_MAX_LOG_DATA
== 0 ||
1366 lwb_sp
< reclen
+ dlen
% ZIL_MAX_LOG_DATA
))) {
1367 lwb
= zil_lwb_write_issue(zilog
, lwb
);
1370 zil_lwb_write_open(zilog
, lwb
);
1371 ASSERT(LWB_EMPTY(lwb
));
1372 lwb_sp
= lwb
->lwb_sz
- lwb
->lwb_nused
;
1373 ASSERT3U(reclen
+ MIN(dlen
, sizeof (uint64_t)), <=, lwb_sp
);
1376 dnow
= MIN(dlen
, lwb_sp
- reclen
);
1377 lr_buf
= lwb
->lwb_buf
+ lwb
->lwb_nused
;
1378 bcopy(lrc
, lr_buf
, reclen
);
1379 lrcb
= (lr_t
*)lr_buf
; /* Like lrc, but inside lwb. */
1380 lrwb
= (lr_write_t
*)lrcb
; /* Like lrw, but inside lwb. */
1383 * If it's a write, fetch the data or get its blkptr as appropriate.
1385 if (lrc
->lrc_txtype
== TX_WRITE
) {
1386 if (txg
> spa_freeze_txg(zilog
->zl_spa
))
1387 txg_wait_synced(zilog
->zl_dmu_pool
, txg
);
1388 if (itx
->itx_wr_state
!= WR_COPIED
) {
1392 if (itx
->itx_wr_state
== WR_NEED_COPY
) {
1393 dbuf
= lr_buf
+ reclen
;
1394 lrcb
->lrc_reclen
+= dnow
;
1395 if (lrwb
->lr_length
> dnow
)
1396 lrwb
->lr_length
= dnow
;
1397 lrw
->lr_offset
+= dnow
;
1398 lrw
->lr_length
-= dnow
;
1400 ASSERT(itx
->itx_wr_state
== WR_INDIRECT
);
1405 * We pass in the "lwb_write_zio" rather than
1406 * "lwb_root_zio" so that the "lwb_write_zio"
1407 * becomes the parent of any zio's created by
1408 * the "zl_get_data" callback. The vdevs are
1409 * flushed after the "lwb_write_zio" completes,
1410 * so we want to make sure that completion
1411 * callback waits for these additional zio's,
1412 * such that the vdevs used by those zio's will
1413 * be included in the lwb's vdev tree, and those
1414 * vdevs will be properly flushed. If we passed
1415 * in "lwb_root_zio" here, then these additional
1416 * vdevs may not be flushed; e.g. if these zio's
1417 * completed after "lwb_write_zio" completed.
1419 error
= zilog
->zl_get_data(itx
->itx_private
,
1420 lrwb
, dbuf
, lwb
, lwb
->lwb_write_zio
);
1423 txg_wait_synced(zilog
->zl_dmu_pool
, txg
);
1427 ASSERT(error
== ENOENT
|| error
== EEXIST
||
1435 * We're actually making an entry, so update lrc_seq to be the
1436 * log record sequence number. Note that this is generally not
1437 * equal to the itx sequence number because not all transactions
1438 * are synchronous, and sometimes spa_sync() gets there first.
1440 lrcb
->lrc_seq
= ++zilog
->zl_lr_seq
;
1441 lwb
->lwb_nused
+= reclen
+ dnow
;
1443 zil_lwb_add_txg(lwb
, txg
);
1445 ASSERT3U(lwb
->lwb_nused
, <=, lwb
->lwb_sz
);
1446 ASSERT0(P2PHASE(lwb
->lwb_nused
, sizeof (uint64_t)));
1450 zilog
->zl_cur_used
+= reclen
;
1458 zil_itx_create(uint64_t txtype
, size_t lrsize
)
1462 lrsize
= P2ROUNDUP_TYPED(lrsize
, sizeof (uint64_t), size_t);
1464 itx
= kmem_alloc(offsetof(itx_t
, itx_lr
) + lrsize
, KM_SLEEP
);
1465 itx
->itx_lr
.lrc_txtype
= txtype
;
1466 itx
->itx_lr
.lrc_reclen
= lrsize
;
1467 itx
->itx_lr
.lrc_seq
= 0; /* defensive */
1468 itx
->itx_sync
= B_TRUE
; /* default is synchronous */
1474 zil_itx_destroy(itx_t
*itx
)
1476 kmem_free(itx
, offsetof(itx_t
, itx_lr
) + itx
->itx_lr
.lrc_reclen
);
1480 * Free up the sync and async itxs. The itxs_t has already been detached
1481 * so no locks are needed.
1484 zil_itxg_clean(itxs_t
*itxs
)
1490 itx_async_node_t
*ian
;
1492 list
= &itxs
->i_sync_list
;
1493 while ((itx
= list_head(list
)) != NULL
) {
1495 * In the general case, commit itxs will not be found
1496 * here, as they'll be committed to an lwb via
1497 * zil_lwb_commit(), and free'd in that function. Having
1498 * said that, it is still possible for commit itxs to be
1499 * found here, due to the following race:
1501 * - a thread calls zil_commit() which assigns the
1502 * commit itx to a per-txg i_sync_list
1503 * - zil_itxg_clean() is called (e.g. via spa_sync())
1504 * while the waiter is still on the i_sync_list
1506 * There's nothing to prevent syncing the txg while the
1507 * waiter is on the i_sync_list. This normally doesn't
1508 * happen because spa_sync() is slower than zil_commit(),
1509 * but if zil_commit() calls txg_wait_synced() (e.g.
1510 * because zil_create() or zil_commit_writer_stall() is
1511 * called) we will hit this case.
1513 if (itx
->itx_lr
.lrc_txtype
== TX_COMMIT
)
1514 zil_commit_waiter_skip(itx
->itx_private
);
1516 list_remove(list
, itx
);
1517 zil_itx_destroy(itx
);
1521 t
= &itxs
->i_async_tree
;
1522 while ((ian
= avl_destroy_nodes(t
, &cookie
)) != NULL
) {
1523 list
= &ian
->ia_list
;
1524 while ((itx
= list_head(list
)) != NULL
) {
1525 list_remove(list
, itx
);
1526 /* commit itxs should never be on the async lists. */
1527 ASSERT3U(itx
->itx_lr
.lrc_txtype
, !=, TX_COMMIT
);
1528 zil_itx_destroy(itx
);
1531 kmem_free(ian
, sizeof (itx_async_node_t
));
1535 kmem_free(itxs
, sizeof (itxs_t
));
1539 zil_aitx_compare(const void *x1
, const void *x2
)
1541 const uint64_t o1
= ((itx_async_node_t
*)x1
)->ia_foid
;
1542 const uint64_t o2
= ((itx_async_node_t
*)x2
)->ia_foid
;
1553 * Remove all async itx with the given oid.
1556 zil_remove_async(zilog_t
*zilog
, uint64_t oid
)
1559 itx_async_node_t
*ian
;
1566 list_create(&clean_list
, sizeof (itx_t
), offsetof(itx_t
, itx_node
));
1568 if (spa_freeze_txg(zilog
->zl_spa
) != UINT64_MAX
) /* ziltest support */
1571 otxg
= spa_last_synced_txg(zilog
->zl_spa
) + 1;
1573 for (txg
= otxg
; txg
< (otxg
+ TXG_CONCURRENT_STATES
); txg
++) {
1574 itxg_t
*itxg
= &zilog
->zl_itxg
[txg
& TXG_MASK
];
1576 mutex_enter(&itxg
->itxg_lock
);
1577 if (itxg
->itxg_txg
!= txg
) {
1578 mutex_exit(&itxg
->itxg_lock
);
1583 * Locate the object node and append its list.
1585 t
= &itxg
->itxg_itxs
->i_async_tree
;
1586 ian
= avl_find(t
, &oid
, &where
);
1588 list_move_tail(&clean_list
, &ian
->ia_list
);
1589 mutex_exit(&itxg
->itxg_lock
);
1591 while ((itx
= list_head(&clean_list
)) != NULL
) {
1592 list_remove(&clean_list
, itx
);
1593 /* commit itxs should never be on the async lists. */
1594 ASSERT3U(itx
->itx_lr
.lrc_txtype
, !=, TX_COMMIT
);
1595 zil_itx_destroy(itx
);
1597 list_destroy(&clean_list
);
1601 zil_itx_assign(zilog_t
*zilog
, itx_t
*itx
, dmu_tx_t
*tx
)
1605 itxs_t
*itxs
, *clean
= NULL
;
1608 * Object ids can be re-instantiated in the next txg so
1609 * remove any async transactions to avoid future leaks.
1610 * This can happen if a fsync occurs on the re-instantiated
1611 * object for a WR_INDIRECT or WR_NEED_COPY write, which gets
1612 * the new file data and flushes a write record for the old object.
1614 if ((itx
->itx_lr
.lrc_txtype
& ~TX_CI
) == TX_REMOVE
)
1615 zil_remove_async(zilog
, itx
->itx_oid
);
1618 * Ensure the data of a renamed file is committed before the rename.
1620 if ((itx
->itx_lr
.lrc_txtype
& ~TX_CI
) == TX_RENAME
)
1621 zil_async_to_sync(zilog
, itx
->itx_oid
);
1623 if (spa_freeze_txg(zilog
->zl_spa
) != UINT64_MAX
)
1626 txg
= dmu_tx_get_txg(tx
);
1628 itxg
= &zilog
->zl_itxg
[txg
& TXG_MASK
];
1629 mutex_enter(&itxg
->itxg_lock
);
1630 itxs
= itxg
->itxg_itxs
;
1631 if (itxg
->itxg_txg
!= txg
) {
1634 * The zil_clean callback hasn't got around to cleaning
1635 * this itxg. Save the itxs for release below.
1636 * This should be rare.
1638 zfs_dbgmsg("zil_itx_assign: missed itx cleanup for "
1639 "txg %llu", itxg
->itxg_txg
);
1640 clean
= itxg
->itxg_itxs
;
1642 itxg
->itxg_txg
= txg
;
1643 itxs
= itxg
->itxg_itxs
= kmem_zalloc(sizeof (itxs_t
), KM_SLEEP
);
1645 list_create(&itxs
->i_sync_list
, sizeof (itx_t
),
1646 offsetof(itx_t
, itx_node
));
1647 avl_create(&itxs
->i_async_tree
, zil_aitx_compare
,
1648 sizeof (itx_async_node_t
),
1649 offsetof(itx_async_node_t
, ia_node
));
1651 if (itx
->itx_sync
) {
1652 list_insert_tail(&itxs
->i_sync_list
, itx
);
1654 avl_tree_t
*t
= &itxs
->i_async_tree
;
1655 uint64_t foid
= ((lr_ooo_t
*)&itx
->itx_lr
)->lr_foid
;
1656 itx_async_node_t
*ian
;
1659 ian
= avl_find(t
, &foid
, &where
);
1661 ian
= kmem_alloc(sizeof (itx_async_node_t
), KM_SLEEP
);
1662 list_create(&ian
->ia_list
, sizeof (itx_t
),
1663 offsetof(itx_t
, itx_node
));
1664 ian
->ia_foid
= foid
;
1665 avl_insert(t
, ian
, where
);
1667 list_insert_tail(&ian
->ia_list
, itx
);
1670 itx
->itx_lr
.lrc_txg
= dmu_tx_get_txg(tx
);
1673 * We don't want to dirty the ZIL using ZILTEST_TXG, because
1674 * zil_clean() will never be called using ZILTEST_TXG. Thus, we
1675 * need to be careful to always dirty the ZIL using the "real"
1676 * TXG (not itxg_txg) even when the SPA is frozen.
1678 zilog_dirty(zilog
, dmu_tx_get_txg(tx
));
1679 mutex_exit(&itxg
->itxg_lock
);
1681 /* Release the old itxs now we've dropped the lock */
1683 zil_itxg_clean(clean
);
1687 * If there are any in-memory intent log transactions which have now been
1688 * synced then start up a taskq to free them. We should only do this after we
1689 * have written out the uberblocks (i.e. txg has been comitted) so that
1690 * don't inadvertently clean out in-memory log records that would be required
1694 zil_clean(zilog_t
*zilog
, uint64_t synced_txg
)
1696 itxg_t
*itxg
= &zilog
->zl_itxg
[synced_txg
& TXG_MASK
];
1699 ASSERT3U(synced_txg
, <, ZILTEST_TXG
);
1701 mutex_enter(&itxg
->itxg_lock
);
1702 if (itxg
->itxg_itxs
== NULL
|| itxg
->itxg_txg
== ZILTEST_TXG
) {
1703 mutex_exit(&itxg
->itxg_lock
);
1706 ASSERT3U(itxg
->itxg_txg
, <=, synced_txg
);
1707 ASSERT3U(itxg
->itxg_txg
, !=, 0);
1708 clean_me
= itxg
->itxg_itxs
;
1709 itxg
->itxg_itxs
= NULL
;
1711 mutex_exit(&itxg
->itxg_lock
);
1713 * Preferably start a task queue to free up the old itxs but
1714 * if taskq_dispatch can't allocate resources to do that then
1715 * free it in-line. This should be rare. Note, using TQ_SLEEP
1716 * created a bad performance problem.
1718 ASSERT3P(zilog
->zl_dmu_pool
, !=, NULL
);
1719 ASSERT3P(zilog
->zl_dmu_pool
->dp_zil_clean_taskq
, !=, NULL
);
1720 if (taskq_dispatch(zilog
->zl_dmu_pool
->dp_zil_clean_taskq
,
1721 (void (*)(void *))zil_itxg_clean
, clean_me
, TQ_NOSLEEP
) == NULL
)
1722 zil_itxg_clean(clean_me
);
1726 * This function will traverse the queue of itxs that need to be
1727 * committed, and move them onto the ZIL's zl_itx_commit_list.
1730 zil_get_commit_list(zilog_t
*zilog
)
1733 list_t
*commit_list
= &zilog
->zl_itx_commit_list
;
1735 ASSERT(MUTEX_HELD(&zilog
->zl_issuer_lock
));
1737 if (spa_freeze_txg(zilog
->zl_spa
) != UINT64_MAX
) /* ziltest support */
1740 otxg
= spa_last_synced_txg(zilog
->zl_spa
) + 1;
1743 * This is inherently racy, since there is nothing to prevent
1744 * the last synced txg from changing. That's okay since we'll
1745 * only commit things in the future.
1747 for (txg
= otxg
; txg
< (otxg
+ TXG_CONCURRENT_STATES
); txg
++) {
1748 itxg_t
*itxg
= &zilog
->zl_itxg
[txg
& TXG_MASK
];
1750 mutex_enter(&itxg
->itxg_lock
);
1751 if (itxg
->itxg_txg
!= txg
) {
1752 mutex_exit(&itxg
->itxg_lock
);
1757 * If we're adding itx records to the zl_itx_commit_list,
1758 * then the zil better be dirty in this "txg". We can assert
1759 * that here since we're holding the itxg_lock which will
1760 * prevent spa_sync from cleaning it. Once we add the itxs
1761 * to the zl_itx_commit_list we must commit it to disk even
1762 * if it's unnecessary (i.e. the txg was synced).
1764 ASSERT(zilog_is_dirty_in_txg(zilog
, txg
) ||
1765 spa_freeze_txg(zilog
->zl_spa
) != UINT64_MAX
);
1766 list_move_tail(commit_list
, &itxg
->itxg_itxs
->i_sync_list
);
1768 mutex_exit(&itxg
->itxg_lock
);
1773 * Move the async itxs for a specified object to commit into sync lists.
1776 zil_async_to_sync(zilog_t
*zilog
, uint64_t foid
)
1779 itx_async_node_t
*ian
;
1783 if (spa_freeze_txg(zilog
->zl_spa
) != UINT64_MAX
) /* ziltest support */
1786 otxg
= spa_last_synced_txg(zilog
->zl_spa
) + 1;
1789 * This is inherently racy, since there is nothing to prevent
1790 * the last synced txg from changing.
1792 for (txg
= otxg
; txg
< (otxg
+ TXG_CONCURRENT_STATES
); txg
++) {
1793 itxg_t
*itxg
= &zilog
->zl_itxg
[txg
& TXG_MASK
];
1795 mutex_enter(&itxg
->itxg_lock
);
1796 if (itxg
->itxg_txg
!= txg
) {
1797 mutex_exit(&itxg
->itxg_lock
);
1802 * If a foid is specified then find that node and append its
1803 * list. Otherwise walk the tree appending all the lists
1804 * to the sync list. We add to the end rather than the
1805 * beginning to ensure the create has happened.
1807 t
= &itxg
->itxg_itxs
->i_async_tree
;
1809 ian
= avl_find(t
, &foid
, &where
);
1811 list_move_tail(&itxg
->itxg_itxs
->i_sync_list
,
1815 void *cookie
= NULL
;
1817 while ((ian
= avl_destroy_nodes(t
, &cookie
)) != NULL
) {
1818 list_move_tail(&itxg
->itxg_itxs
->i_sync_list
,
1820 list_destroy(&ian
->ia_list
);
1821 kmem_free(ian
, sizeof (itx_async_node_t
));
1824 mutex_exit(&itxg
->itxg_lock
);
1829 * This function will prune commit itxs that are at the head of the
1830 * commit list (it won't prune past the first non-commit itx), and
1831 * either: a) attach them to the last lwb that's still pending
1832 * completion, or b) skip them altogether.
1834 * This is used as a performance optimization to prevent commit itxs
1835 * from generating new lwbs when it's unnecessary to do so.
1838 zil_prune_commit_list(zilog_t
*zilog
)
1842 ASSERT(MUTEX_HELD(&zilog
->zl_issuer_lock
));
1844 while (itx
= list_head(&zilog
->zl_itx_commit_list
)) {
1845 lr_t
*lrc
= &itx
->itx_lr
;
1846 if (lrc
->lrc_txtype
!= TX_COMMIT
)
1849 mutex_enter(&zilog
->zl_lock
);
1851 lwb_t
*last_lwb
= zilog
->zl_last_lwb_opened
;
1852 if (last_lwb
== NULL
|| last_lwb
->lwb_state
== LWB_STATE_DONE
) {
1854 * All of the itxs this waiter was waiting on
1855 * must have already completed (or there were
1856 * never any itx's for it to wait on), so it's
1857 * safe to skip this waiter and mark it done.
1859 zil_commit_waiter_skip(itx
->itx_private
);
1861 zil_commit_waiter_link_lwb(itx
->itx_private
, last_lwb
);
1862 itx
->itx_private
= NULL
;
1865 mutex_exit(&zilog
->zl_lock
);
1867 list_remove(&zilog
->zl_itx_commit_list
, itx
);
1868 zil_itx_destroy(itx
);
1871 IMPLY(itx
!= NULL
, itx
->itx_lr
.lrc_txtype
!= TX_COMMIT
);
1875 zil_commit_writer_stall(zilog_t
*zilog
)
1878 * When zio_alloc_zil() fails to allocate the next lwb block on
1879 * disk, we must call txg_wait_synced() to ensure all of the
1880 * lwbs in the zilog's zl_lwb_list are synced and then freed (in
1881 * zil_sync()), such that any subsequent ZIL writer (i.e. a call
1882 * to zil_process_commit_list()) will have to call zil_create(),
1883 * and start a new ZIL chain.
1885 * Since zil_alloc_zil() failed, the lwb that was previously
1886 * issued does not have a pointer to the "next" lwb on disk.
1887 * Thus, if another ZIL writer thread was to allocate the "next"
1888 * on-disk lwb, that block could be leaked in the event of a
1889 * crash (because the previous lwb on-disk would not point to
1892 * We must hold the zilog's zl_issuer_lock while we do this, to
1893 * ensure no new threads enter zil_process_commit_list() until
1894 * all lwb's in the zl_lwb_list have been synced and freed
1895 * (which is achieved via the txg_wait_synced() call).
1897 ASSERT(MUTEX_HELD(&zilog
->zl_issuer_lock
));
1898 txg_wait_synced(zilog
->zl_dmu_pool
, 0);
1899 ASSERT3P(list_tail(&zilog
->zl_lwb_list
), ==, NULL
);
1903 * This function will traverse the commit list, creating new lwbs as
1904 * needed, and committing the itxs from the commit list to these newly
1905 * created lwbs. Additionally, as a new lwb is created, the previous
1906 * lwb will be issued to the zio layer to be written to disk.
1909 zil_process_commit_list(zilog_t
*zilog
)
1911 spa_t
*spa
= zilog
->zl_spa
;
1912 list_t nolwb_waiters
;
1916 ASSERT(MUTEX_HELD(&zilog
->zl_issuer_lock
));
1919 * Return if there's nothing to commit before we dirty the fs by
1920 * calling zil_create().
1922 if (list_head(&zilog
->zl_itx_commit_list
) == NULL
)
1925 list_create(&nolwb_waiters
, sizeof (zil_commit_waiter_t
),
1926 offsetof(zil_commit_waiter_t
, zcw_node
));
1928 lwb
= list_tail(&zilog
->zl_lwb_list
);
1930 lwb
= zil_create(zilog
);
1932 ASSERT3S(lwb
->lwb_state
, !=, LWB_STATE_ISSUED
);
1933 ASSERT3S(lwb
->lwb_state
, !=, LWB_STATE_DONE
);
1936 while (itx
= list_head(&zilog
->zl_itx_commit_list
)) {
1937 lr_t
*lrc
= &itx
->itx_lr
;
1938 uint64_t txg
= lrc
->lrc_txg
;
1940 ASSERT3U(txg
, !=, 0);
1942 if (lrc
->lrc_txtype
== TX_COMMIT
) {
1943 DTRACE_PROBE2(zil__process__commit__itx
,
1944 zilog_t
*, zilog
, itx_t
*, itx
);
1946 DTRACE_PROBE2(zil__process__normal__itx
,
1947 zilog_t
*, zilog
, itx_t
*, itx
);
1950 boolean_t synced
= txg
<= spa_last_synced_txg(spa
);
1951 boolean_t frozen
= txg
> spa_freeze_txg(spa
);
1954 * If the txg of this itx has already been synced out, then
1955 * we don't need to commit this itx to an lwb. This is
1956 * because the data of this itx will have already been
1957 * written to the main pool. This is inherently racy, and
1958 * it's still ok to commit an itx whose txg has already
1959 * been synced; this will result in a write that's
1960 * unnecessary, but will do no harm.
1962 * With that said, we always want to commit TX_COMMIT itxs
1963 * to an lwb, regardless of whether or not that itx's txg
1964 * has been synced out. We do this to ensure any OPENED lwb
1965 * will always have at least one zil_commit_waiter_t linked
1968 * As a counter-example, if we skipped TX_COMMIT itx's
1969 * whose txg had already been synced, the following
1970 * situation could occur if we happened to be racing with
1973 * 1. we commit a non-TX_COMMIT itx to an lwb, where the
1974 * itx's txg is 10 and the last synced txg is 9.
1975 * 2. spa_sync finishes syncing out txg 10.
1976 * 3. we move to the next itx in the list, it's a TX_COMMIT
1977 * whose txg is 10, so we skip it rather than committing
1978 * it to the lwb used in (1).
1980 * If the itx that is skipped in (3) is the last TX_COMMIT
1981 * itx in the commit list, than it's possible for the lwb
1982 * used in (1) to remain in the OPENED state indefinitely.
1984 * To prevent the above scenario from occuring, ensuring
1985 * that once an lwb is OPENED it will transition to ISSUED
1986 * and eventually DONE, we always commit TX_COMMIT itx's to
1987 * an lwb here, even if that itx's txg has already been
1990 * Finally, if the pool is frozen, we _always_ commit the
1991 * itx. The point of freezing the pool is to prevent data
1992 * from being written to the main pool via spa_sync, and
1993 * instead rely solely on the ZIL to persistently store the
1994 * data; i.e. when the pool is frozen, the last synced txg
1995 * value can't be trusted.
1997 if (frozen
|| !synced
|| lrc
->lrc_txtype
== TX_COMMIT
) {
1999 lwb
= zil_lwb_commit(zilog
, itx
, lwb
);
2000 } else if (lrc
->lrc_txtype
== TX_COMMIT
) {
2001 ASSERT3P(lwb
, ==, NULL
);
2002 zil_commit_waiter_link_nolwb(
2003 itx
->itx_private
, &nolwb_waiters
);
2007 list_remove(&zilog
->zl_itx_commit_list
, itx
);
2008 zil_itx_destroy(itx
);
2013 * This indicates zio_alloc_zil() failed to allocate the
2014 * "next" lwb on-disk. When this happens, we must stall
2015 * the ZIL write pipeline; see the comment within
2016 * zil_commit_writer_stall() for more details.
2018 zil_commit_writer_stall(zilog
);
2021 * Additionally, we have to signal and mark the "nolwb"
2022 * waiters as "done" here, since without an lwb, we
2023 * can't do this via zil_lwb_flush_vdevs_done() like
2026 zil_commit_waiter_t
*zcw
;
2027 while (zcw
= list_head(&nolwb_waiters
)) {
2028 zil_commit_waiter_skip(zcw
);
2029 list_remove(&nolwb_waiters
, zcw
);
2032 ASSERT(list_is_empty(&nolwb_waiters
));
2033 ASSERT3P(lwb
, !=, NULL
);
2034 ASSERT3S(lwb
->lwb_state
, !=, LWB_STATE_ISSUED
);
2035 ASSERT3S(lwb
->lwb_state
, !=, LWB_STATE_DONE
);
2038 * At this point, the ZIL block pointed at by the "lwb"
2039 * variable is in one of the following states: "closed"
2042 * If its "closed", then no itxs have been committed to
2043 * it, so there's no point in issuing its zio (i.e.
2046 * If its "open" state, then it contains one or more
2047 * itxs that eventually need to be committed to stable
2048 * storage. In this case we intentionally do not issue
2049 * the lwb's zio to disk yet, and instead rely on one of
2050 * the following two mechanisms for issuing the zio:
2052 * 1. Ideally, there will be more ZIL activity occuring
2053 * on the system, such that this function will be
2054 * immediately called again (not necessarily by the same
2055 * thread) and this lwb's zio will be issued via
2056 * zil_lwb_commit(). This way, the lwb is guaranteed to
2057 * be "full" when it is issued to disk, and we'll make
2058 * use of the lwb's size the best we can.
2060 * 2. If there isn't sufficient ZIL activity occuring on
2061 * the system, such that this lwb's zio isn't issued via
2062 * zil_lwb_commit(), zil_commit_waiter() will issue the
2063 * lwb's zio. If this occurs, the lwb is not guaranteed
2064 * to be "full" by the time its zio is issued, and means
2065 * the size of the lwb was "too large" given the amount
2066 * of ZIL activity occuring on the system at that time.
2068 * We do this for a couple of reasons:
2070 * 1. To try and reduce the number of IOPs needed to
2071 * write the same number of itxs. If an lwb has space
2072 * available in it's buffer for more itxs, and more itxs
2073 * will be committed relatively soon (relative to the
2074 * latency of performing a write), then it's beneficial
2075 * to wait for these "next" itxs. This way, more itxs
2076 * can be committed to stable storage with fewer writes.
2078 * 2. To try and use the largest lwb block size that the
2079 * incoming rate of itxs can support. Again, this is to
2080 * try and pack as many itxs into as few lwbs as
2081 * possible, without significantly impacting the latency
2082 * of each individual itx.
2088 * This function is responsible for ensuring the passed in commit waiter
2089 * (and associated commit itx) is committed to an lwb. If the waiter is
2090 * not already committed to an lwb, all itxs in the zilog's queue of
2091 * itxs will be processed. The assumption is the passed in waiter's
2092 * commit itx will found in the queue just like the other non-commit
2093 * itxs, such that when the entire queue is processed, the waiter will
2094 * have been commited to an lwb.
2096 * The lwb associated with the passed in waiter is not guaranteed to
2097 * have been issued by the time this function completes. If the lwb is
2098 * not issued, we rely on future calls to zil_commit_writer() to issue
2099 * the lwb, or the timeout mechanism found in zil_commit_waiter().
2102 zil_commit_writer(zilog_t
*zilog
, zil_commit_waiter_t
*zcw
)
2104 ASSERT(!MUTEX_HELD(&zilog
->zl_lock
));
2105 ASSERT(spa_writeable(zilog
->zl_spa
));
2107 mutex_enter(&zilog
->zl_issuer_lock
);
2109 if (zcw
->zcw_lwb
!= NULL
|| zcw
->zcw_done
) {
2111 * It's possible that, while we were waiting to acquire
2112 * the "zl_issuer_lock", another thread committed this
2113 * waiter to an lwb. If that occurs, we bail out early,
2114 * without processing any of the zilog's queue of itxs.
2116 * On certain workloads and system configurations, the
2117 * "zl_issuer_lock" can become highly contended. In an
2118 * attempt to reduce this contention, we immediately drop
2119 * the lock if the waiter has already been processed.
2121 * We've measured this optimization to reduce CPU spent
2122 * contending on this lock by up to 5%, using a system
2123 * with 32 CPUs, low latency storage (~50 usec writes),
2124 * and 1024 threads performing sync writes.
2129 zil_get_commit_list(zilog
);
2130 zil_prune_commit_list(zilog
);
2131 zil_process_commit_list(zilog
);
2134 mutex_exit(&zilog
->zl_issuer_lock
);
2138 zil_commit_waiter_timeout(zilog_t
*zilog
, zil_commit_waiter_t
*zcw
)
2140 ASSERT(!MUTEX_HELD(&zilog
->zl_issuer_lock
));
2141 ASSERT(MUTEX_HELD(&zcw
->zcw_lock
));
2142 ASSERT3B(zcw
->zcw_done
, ==, B_FALSE
);
2144 lwb_t
*lwb
= zcw
->zcw_lwb
;
2145 ASSERT3P(lwb
, !=, NULL
);
2146 ASSERT3S(lwb
->lwb_state
, !=, LWB_STATE_CLOSED
);
2149 * If the lwb has already been issued by another thread, we can
2150 * immediately return since there's no work to be done (the
2151 * point of this function is to issue the lwb). Additionally, we
2152 * do this prior to acquiring the zl_issuer_lock, to avoid
2153 * acquiring it when it's not necessary to do so.
2155 if (lwb
->lwb_state
== LWB_STATE_ISSUED
||
2156 lwb
->lwb_state
== LWB_STATE_DONE
)
2160 * In order to call zil_lwb_write_issue() we must hold the
2161 * zilog's "zl_issuer_lock". We can't simply acquire that lock,
2162 * since we're already holding the commit waiter's "zcw_lock",
2163 * and those two locks are aquired in the opposite order
2166 mutex_exit(&zcw
->zcw_lock
);
2167 mutex_enter(&zilog
->zl_issuer_lock
);
2168 mutex_enter(&zcw
->zcw_lock
);
2171 * Since we just dropped and re-acquired the commit waiter's
2172 * lock, we have to re-check to see if the waiter was marked
2173 * "done" during that process. If the waiter was marked "done",
2174 * the "lwb" pointer is no longer valid (it can be free'd after
2175 * the waiter is marked "done"), so without this check we could
2176 * wind up with a use-after-free error below.
2181 ASSERT3P(lwb
, ==, zcw
->zcw_lwb
);
2184 * We've already checked this above, but since we hadn't acquired
2185 * the zilog's zl_issuer_lock, we have to perform this check a
2186 * second time while holding the lock.
2188 * We don't need to hold the zl_lock since the lwb cannot transition
2189 * from OPENED to ISSUED while we hold the zl_issuer_lock. The lwb
2190 * _can_ transition from ISSUED to DONE, but it's OK to race with
2191 * that transition since we treat the lwb the same, whether it's in
2192 * the ISSUED or DONE states.
2194 * The important thing, is we treat the lwb differently depending on
2195 * if it's ISSUED or OPENED, and block any other threads that might
2196 * attempt to issue this lwb. For that reason we hold the
2197 * zl_issuer_lock when checking the lwb_state; we must not call
2198 * zil_lwb_write_issue() if the lwb had already been issued.
2200 * See the comment above the lwb_state_t structure definition for
2201 * more details on the lwb states, and locking requirements.
2203 if (lwb
->lwb_state
== LWB_STATE_ISSUED
||
2204 lwb
->lwb_state
== LWB_STATE_DONE
)
2207 ASSERT3S(lwb
->lwb_state
, ==, LWB_STATE_OPENED
);
2210 * As described in the comments above zil_commit_waiter() and
2211 * zil_process_commit_list(), we need to issue this lwb's zio
2212 * since we've reached the commit waiter's timeout and it still
2213 * hasn't been issued.
2215 lwb_t
*nlwb
= zil_lwb_write_issue(zilog
, lwb
);
2217 ASSERT3S(lwb
->lwb_state
, !=, LWB_STATE_OPENED
);
2220 * Since the lwb's zio hadn't been issued by the time this thread
2221 * reached its timeout, we reset the zilog's "zl_cur_used" field
2222 * to influence the zil block size selection algorithm.
2224 * By having to issue the lwb's zio here, it means the size of the
2225 * lwb was too large, given the incoming throughput of itxs. By
2226 * setting "zl_cur_used" to zero, we communicate this fact to the
2227 * block size selection algorithm, so it can take this informaiton
2228 * into account, and potentially select a smaller size for the
2229 * next lwb block that is allocated.
2231 zilog
->zl_cur_used
= 0;
2235 * When zil_lwb_write_issue() returns NULL, this
2236 * indicates zio_alloc_zil() failed to allocate the
2237 * "next" lwb on-disk. When this occurs, the ZIL write
2238 * pipeline must be stalled; see the comment within the
2239 * zil_commit_writer_stall() function for more details.
2241 * We must drop the commit waiter's lock prior to
2242 * calling zil_commit_writer_stall() or else we can wind
2243 * up with the following deadlock:
2245 * - This thread is waiting for the txg to sync while
2246 * holding the waiter's lock; txg_wait_synced() is
2247 * used within txg_commit_writer_stall().
2249 * - The txg can't sync because it is waiting for this
2250 * lwb's zio callback to call dmu_tx_commit().
2252 * - The lwb's zio callback can't call dmu_tx_commit()
2253 * because it's blocked trying to acquire the waiter's
2254 * lock, which occurs prior to calling dmu_tx_commit()
2256 mutex_exit(&zcw
->zcw_lock
);
2257 zil_commit_writer_stall(zilog
);
2258 mutex_enter(&zcw
->zcw_lock
);
2262 mutex_exit(&zilog
->zl_issuer_lock
);
2263 ASSERT(MUTEX_HELD(&zcw
->zcw_lock
));
2267 * This function is responsible for performing the following two tasks:
2269 * 1. its primary responsibility is to block until the given "commit
2270 * waiter" is considered "done".
2272 * 2. its secondary responsibility is to issue the zio for the lwb that
2273 * the given "commit waiter" is waiting on, if this function has
2274 * waited "long enough" and the lwb is still in the "open" state.
2276 * Given a sufficient amount of itxs being generated and written using
2277 * the ZIL, the lwb's zio will be issued via the zil_lwb_commit()
2278 * function. If this does not occur, this secondary responsibility will
2279 * ensure the lwb is issued even if there is not other synchronous
2280 * activity on the system.
2282 * For more details, see zil_process_commit_list(); more specifically,
2283 * the comment at the bottom of that function.
2286 zil_commit_waiter(zilog_t
*zilog
, zil_commit_waiter_t
*zcw
)
2288 ASSERT(!MUTEX_HELD(&zilog
->zl_lock
));
2289 ASSERT(!MUTEX_HELD(&zilog
->zl_issuer_lock
));
2290 ASSERT(spa_writeable(zilog
->zl_spa
));
2292 mutex_enter(&zcw
->zcw_lock
);
2295 * The timeout is scaled based on the lwb latency to avoid
2296 * significantly impacting the latency of each individual itx.
2297 * For more details, see the comment at the bottom of the
2298 * zil_process_commit_list() function.
2300 int pct
= MAX(zfs_commit_timeout_pct
, 1);
2301 hrtime_t sleep
= (zilog
->zl_last_lwb_latency
* pct
) / 100;
2302 hrtime_t wakeup
= gethrtime() + sleep
;
2303 boolean_t timedout
= B_FALSE
;
2305 while (!zcw
->zcw_done
) {
2306 ASSERT(MUTEX_HELD(&zcw
->zcw_lock
));
2308 lwb_t
*lwb
= zcw
->zcw_lwb
;
2311 * Usually, the waiter will have a non-NULL lwb field here,
2312 * but it's possible for it to be NULL as a result of
2313 * zil_commit() racing with spa_sync().
2315 * When zil_clean() is called, it's possible for the itxg
2316 * list (which may be cleaned via a taskq) to contain
2317 * commit itxs. When this occurs, the commit waiters linked
2318 * off of these commit itxs will not be committed to an
2319 * lwb. Additionally, these commit waiters will not be
2320 * marked done until zil_commit_waiter_skip() is called via
2323 * Thus, it's possible for this commit waiter (i.e. the
2324 * "zcw" variable) to be found in this "in between" state;
2325 * where it's "zcw_lwb" field is NULL, and it hasn't yet
2326 * been skipped, so it's "zcw_done" field is still B_FALSE.
2328 IMPLY(lwb
!= NULL
, lwb
->lwb_state
!= LWB_STATE_CLOSED
);
2330 if (lwb
!= NULL
&& lwb
->lwb_state
== LWB_STATE_OPENED
) {
2331 ASSERT3B(timedout
, ==, B_FALSE
);
2334 * If the lwb hasn't been issued yet, then we
2335 * need to wait with a timeout, in case this
2336 * function needs to issue the lwb after the
2337 * timeout is reached; responsibility (2) from
2338 * the comment above this function.
2340 clock_t timeleft
= cv_timedwait_hires(&zcw
->zcw_cv
,
2341 &zcw
->zcw_lock
, wakeup
, USEC2NSEC(1),
2342 CALLOUT_FLAG_ABSOLUTE
);
2344 if (timeleft
>= 0 || zcw
->zcw_done
)
2348 zil_commit_waiter_timeout(zilog
, zcw
);
2350 if (!zcw
->zcw_done
) {
2352 * If the commit waiter has already been
2353 * marked "done", it's possible for the
2354 * waiter's lwb structure to have already
2355 * been freed. Thus, we can only reliably
2356 * make these assertions if the waiter
2359 ASSERT3P(lwb
, ==, zcw
->zcw_lwb
);
2360 ASSERT3S(lwb
->lwb_state
, !=, LWB_STATE_OPENED
);
2364 * If the lwb isn't open, then it must have already
2365 * been issued. In that case, there's no need to
2366 * use a timeout when waiting for the lwb to
2369 * Additionally, if the lwb is NULL, the waiter
2370 * will soon be signalled and marked done via
2371 * zil_clean() and zil_itxg_clean(), so no timeout
2376 lwb
->lwb_state
== LWB_STATE_ISSUED
||
2377 lwb
->lwb_state
== LWB_STATE_DONE
);
2378 cv_wait(&zcw
->zcw_cv
, &zcw
->zcw_lock
);
2382 mutex_exit(&zcw
->zcw_lock
);
2385 static zil_commit_waiter_t
*
2386 zil_alloc_commit_waiter()
2388 zil_commit_waiter_t
*zcw
= kmem_cache_alloc(zil_zcw_cache
, KM_SLEEP
);
2390 cv_init(&zcw
->zcw_cv
, NULL
, CV_DEFAULT
, NULL
);
2391 mutex_init(&zcw
->zcw_lock
, NULL
, MUTEX_DEFAULT
, NULL
);
2392 list_link_init(&zcw
->zcw_node
);
2393 zcw
->zcw_lwb
= NULL
;
2394 zcw
->zcw_done
= B_FALSE
;
2395 zcw
->zcw_zio_error
= 0;
2401 zil_free_commit_waiter(zil_commit_waiter_t
*zcw
)
2403 ASSERT(!list_link_active(&zcw
->zcw_node
));
2404 ASSERT3P(zcw
->zcw_lwb
, ==, NULL
);
2405 ASSERT3B(zcw
->zcw_done
, ==, B_TRUE
);
2406 mutex_destroy(&zcw
->zcw_lock
);
2407 cv_destroy(&zcw
->zcw_cv
);
2408 kmem_cache_free(zil_zcw_cache
, zcw
);
2412 * This function is used to create a TX_COMMIT itx and assign it. This
2413 * way, it will be linked into the ZIL's list of synchronous itxs, and
2414 * then later committed to an lwb (or skipped) when
2415 * zil_process_commit_list() is called.
2418 zil_commit_itx_assign(zilog_t
*zilog
, zil_commit_waiter_t
*zcw
)
2420 dmu_tx_t
*tx
= dmu_tx_create(zilog
->zl_os
);
2421 VERIFY0(dmu_tx_assign(tx
, TXG_WAIT
));
2423 itx_t
*itx
= zil_itx_create(TX_COMMIT
, sizeof (lr_t
));
2424 itx
->itx_sync
= B_TRUE
;
2425 itx
->itx_private
= zcw
;
2427 zil_itx_assign(zilog
, itx
, tx
);
2433 * Commit ZFS Intent Log transactions (itxs) to stable storage.
2435 * When writing ZIL transactions to the on-disk representation of the
2436 * ZIL, the itxs are committed to a Log Write Block (lwb). Multiple
2437 * itxs can be committed to a single lwb. Once a lwb is written and
2438 * committed to stable storage (i.e. the lwb is written, and vdevs have
2439 * been flushed), each itx that was committed to that lwb is also
2440 * considered to be committed to stable storage.
2442 * When an itx is committed to an lwb, the log record (lr_t) contained
2443 * by the itx is copied into the lwb's zio buffer, and once this buffer
2444 * is written to disk, it becomes an on-disk ZIL block.
2446 * As itxs are generated, they're inserted into the ZIL's queue of
2447 * uncommitted itxs. The semantics of zil_commit() are such that it will
2448 * block until all itxs that were in the queue when it was called, are
2449 * committed to stable storage.
2451 * If "foid" is zero, this means all "synchronous" and "asynchronous"
2452 * itxs, for all objects in the dataset, will be committed to stable
2453 * storage prior to zil_commit() returning. If "foid" is non-zero, all
2454 * "synchronous" itxs for all objects, but only "asynchronous" itxs
2455 * that correspond to the foid passed in, will be committed to stable
2456 * storage prior to zil_commit() returning.
2458 * Generally speaking, when zil_commit() is called, the consumer doesn't
2459 * actually care about _all_ of the uncommitted itxs. Instead, they're
2460 * simply trying to waiting for a specific itx to be committed to disk,
2461 * but the interface(s) for interacting with the ZIL don't allow such
2462 * fine-grained communication. A better interface would allow a consumer
2463 * to create and assign an itx, and then pass a reference to this itx to
2464 * zil_commit(); such that zil_commit() would return as soon as that
2465 * specific itx was committed to disk (instead of waiting for _all_
2466 * itxs to be committed).
2468 * When a thread calls zil_commit() a special "commit itx" will be
2469 * generated, along with a corresponding "waiter" for this commit itx.
2470 * zil_commit() will wait on this waiter's CV, such that when the waiter
2471 * is marked done, and signalled, zil_commit() will return.
2473 * This commit itx is inserted into the queue of uncommitted itxs. This
2474 * provides an easy mechanism for determining which itxs were in the
2475 * queue prior to zil_commit() having been called, and which itxs were
2476 * added after zil_commit() was called.
2478 * The commit it is special; it doesn't have any on-disk representation.
2479 * When a commit itx is "committed" to an lwb, the waiter associated
2480 * with it is linked onto the lwb's list of waiters. Then, when that lwb
2481 * completes, each waiter on the lwb's list is marked done and signalled
2482 * -- allowing the thread waiting on the waiter to return from zil_commit().
2484 * It's important to point out a few critical factors that allow us
2485 * to make use of the commit itxs, commit waiters, per-lwb lists of
2486 * commit waiters, and zio completion callbacks like we're doing:
2488 * 1. The list of waiters for each lwb is traversed, and each commit
2489 * waiter is marked "done" and signalled, in the zio completion
2490 * callback of the lwb's zio[*].
2492 * * Actually, the waiters are signalled in the zio completion
2493 * callback of the root zio for the DKIOCFLUSHWRITECACHE commands
2494 * that are sent to the vdevs upon completion of the lwb zio.
2496 * 2. When the itxs are inserted into the ZIL's queue of uncommitted
2497 * itxs, the order in which they are inserted is preserved[*]; as
2498 * itxs are added to the queue, they are added to the tail of
2499 * in-memory linked lists.
2501 * When committing the itxs to lwbs (to be written to disk), they
2502 * are committed in the same order in which the itxs were added to
2503 * the uncommitted queue's linked list(s); i.e. the linked list of
2504 * itxs to commit is traversed from head to tail, and each itx is
2505 * committed to an lwb in that order.
2509 * - the order of "sync" itxs is preserved w.r.t. other
2510 * "sync" itxs, regardless of the corresponding objects.
2511 * - the order of "async" itxs is preserved w.r.t. other
2512 * "async" itxs corresponding to the same object.
2513 * - the order of "async" itxs is *not* preserved w.r.t. other
2514 * "async" itxs corresponding to different objects.
2515 * - the order of "sync" itxs w.r.t. "async" itxs (or vice
2516 * versa) is *not* preserved, even for itxs that correspond
2517 * to the same object.
2519 * For more details, see: zil_itx_assign(), zil_async_to_sync(),
2520 * zil_get_commit_list(), and zil_process_commit_list().
2522 * 3. The lwbs represent a linked list of blocks on disk. Thus, any
2523 * lwb cannot be considered committed to stable storage, until its
2524 * "previous" lwb is also committed to stable storage. This fact,
2525 * coupled with the fact described above, means that itxs are
2526 * committed in (roughly) the order in which they were generated.
2527 * This is essential because itxs are dependent on prior itxs.
2528 * Thus, we *must not* deem an itx as being committed to stable
2529 * storage, until *all* prior itxs have also been committed to
2532 * To enforce this ordering of lwb zio's, while still leveraging as
2533 * much of the underlying storage performance as possible, we rely
2534 * on two fundamental concepts:
2536 * 1. The creation and issuance of lwb zio's is protected by
2537 * the zilog's "zl_issuer_lock", which ensures only a single
2538 * thread is creating and/or issuing lwb's at a time
2539 * 2. The "previous" lwb is a child of the "current" lwb
2540 * (leveraging the zio parent-child depenency graph)
2542 * By relying on this parent-child zio relationship, we can have
2543 * many lwb zio's concurrently issued to the underlying storage,
2544 * but the order in which they complete will be the same order in
2545 * which they were created.
2548 zil_commit(zilog_t
*zilog
, uint64_t foid
)
2551 * We should never attempt to call zil_commit on a snapshot for
2552 * a couple of reasons:
2554 * 1. A snapshot may never be modified, thus it cannot have any
2555 * in-flight itxs that would have modified the dataset.
2557 * 2. By design, when zil_commit() is called, a commit itx will
2558 * be assigned to this zilog; as a result, the zilog will be
2559 * dirtied. We must not dirty the zilog of a snapshot; there's
2560 * checks in the code that enforce this invariant, and will
2561 * cause a panic if it's not upheld.
2563 ASSERT3B(dmu_objset_is_snapshot(zilog
->zl_os
), ==, B_FALSE
);
2565 if (zilog
->zl_sync
== ZFS_SYNC_DISABLED
)
2568 if (!spa_writeable(zilog
->zl_spa
)) {
2570 * If the SPA is not writable, there should never be any
2571 * pending itxs waiting to be committed to disk. If that
2572 * weren't true, we'd skip writing those itxs out, and
2573 * would break the sematics of zil_commit(); thus, we're
2574 * verifying that truth before we return to the caller.
2576 ASSERT(list_is_empty(&zilog
->zl_lwb_list
));
2577 ASSERT3P(zilog
->zl_last_lwb_opened
, ==, NULL
);
2578 for (int i
= 0; i
< TXG_SIZE
; i
++)
2579 ASSERT3P(zilog
->zl_itxg
[i
].itxg_itxs
, ==, NULL
);
2584 * If the ZIL is suspended, we don't want to dirty it by calling
2585 * zil_commit_itx_assign() below, nor can we write out
2586 * lwbs like would be done in zil_commit_write(). Thus, we
2587 * simply rely on txg_wait_synced() to maintain the necessary
2588 * semantics, and avoid calling those functions altogether.
2590 if (zilog
->zl_suspend
> 0) {
2591 txg_wait_synced(zilog
->zl_dmu_pool
, 0);
2595 zil_commit_impl(zilog
, foid
);
2599 zil_commit_impl(zilog_t
*zilog
, uint64_t foid
)
2602 * Move the "async" itxs for the specified foid to the "sync"
2603 * queues, such that they will be later committed (or skipped)
2604 * to an lwb when zil_process_commit_list() is called.
2606 * Since these "async" itxs must be committed prior to this
2607 * call to zil_commit returning, we must perform this operation
2608 * before we call zil_commit_itx_assign().
2610 zil_async_to_sync(zilog
, foid
);
2613 * We allocate a new "waiter" structure which will initially be
2614 * linked to the commit itx using the itx's "itx_private" field.
2615 * Since the commit itx doesn't represent any on-disk state,
2616 * when it's committed to an lwb, rather than copying the its
2617 * lr_t into the lwb's buffer, the commit itx's "waiter" will be
2618 * added to the lwb's list of waiters. Then, when the lwb is
2619 * committed to stable storage, each waiter in the lwb's list of
2620 * waiters will be marked "done", and signalled.
2622 * We must create the waiter and assign the commit itx prior to
2623 * calling zil_commit_writer(), or else our specific commit itx
2624 * is not guaranteed to be committed to an lwb prior to calling
2625 * zil_commit_waiter().
2627 zil_commit_waiter_t
*zcw
= zil_alloc_commit_waiter();
2628 zil_commit_itx_assign(zilog
, zcw
);
2630 zil_commit_writer(zilog
, zcw
);
2631 zil_commit_waiter(zilog
, zcw
);
2633 if (zcw
->zcw_zio_error
!= 0) {
2635 * If there was an error writing out the ZIL blocks that
2636 * this thread is waiting on, then we fallback to
2637 * relying on spa_sync() to write out the data this
2638 * thread is waiting on. Obviously this has performance
2639 * implications, but the expectation is for this to be
2640 * an exceptional case, and shouldn't occur often.
2642 DTRACE_PROBE2(zil__commit__io__error
,
2643 zilog_t
*, zilog
, zil_commit_waiter_t
*, zcw
);
2644 txg_wait_synced(zilog
->zl_dmu_pool
, 0);
2647 zil_free_commit_waiter(zcw
);
2651 * Called in syncing context to free committed log blocks and update log header.
2654 zil_sync(zilog_t
*zilog
, dmu_tx_t
*tx
)
2656 zil_header_t
*zh
= zil_header_in_syncing_context(zilog
);
2657 uint64_t txg
= dmu_tx_get_txg(tx
);
2658 spa_t
*spa
= zilog
->zl_spa
;
2659 uint64_t *replayed_seq
= &zilog
->zl_replayed_seq
[txg
& TXG_MASK
];
2663 * We don't zero out zl_destroy_txg, so make sure we don't try
2664 * to destroy it twice.
2666 if (spa_sync_pass(spa
) != 1)
2669 mutex_enter(&zilog
->zl_lock
);
2671 ASSERT(zilog
->zl_stop_sync
== 0);
2673 if (*replayed_seq
!= 0) {
2674 ASSERT(zh
->zh_replay_seq
< *replayed_seq
);
2675 zh
->zh_replay_seq
= *replayed_seq
;
2679 if (zilog
->zl_destroy_txg
== txg
) {
2680 blkptr_t blk
= zh
->zh_log
;
2682 ASSERT(list_head(&zilog
->zl_lwb_list
) == NULL
);
2684 bzero(zh
, sizeof (zil_header_t
));
2685 bzero(zilog
->zl_replayed_seq
, sizeof (zilog
->zl_replayed_seq
));
2687 if (zilog
->zl_keep_first
) {
2689 * If this block was part of log chain that couldn't
2690 * be claimed because a device was missing during
2691 * zil_claim(), but that device later returns,
2692 * then this block could erroneously appear valid.
2693 * To guard against this, assign a new GUID to the new
2694 * log chain so it doesn't matter what blk points to.
2696 zil_init_log_chain(zilog
, &blk
);
2701 while ((lwb
= list_head(&zilog
->zl_lwb_list
)) != NULL
) {
2702 zh
->zh_log
= lwb
->lwb_blk
;
2703 if (lwb
->lwb_buf
!= NULL
|| lwb
->lwb_max_txg
> txg
)
2705 list_remove(&zilog
->zl_lwb_list
, lwb
);
2706 zio_free(spa
, txg
, &lwb
->lwb_blk
);
2707 zil_free_lwb(zilog
, lwb
);
2710 * If we don't have anything left in the lwb list then
2711 * we've had an allocation failure and we need to zero
2712 * out the zil_header blkptr so that we don't end
2713 * up freeing the same block twice.
2715 if (list_head(&zilog
->zl_lwb_list
) == NULL
)
2716 BP_ZERO(&zh
->zh_log
);
2718 mutex_exit(&zilog
->zl_lock
);
2723 zil_lwb_cons(void *vbuf
, void *unused
, int kmflag
)
2726 list_create(&lwb
->lwb_waiters
, sizeof (zil_commit_waiter_t
),
2727 offsetof(zil_commit_waiter_t
, zcw_node
));
2728 avl_create(&lwb
->lwb_vdev_tree
, zil_lwb_vdev_compare
,
2729 sizeof (zil_vdev_node_t
), offsetof(zil_vdev_node_t
, zv_node
));
2730 mutex_init(&lwb
->lwb_vdev_lock
, NULL
, MUTEX_DEFAULT
, NULL
);
2736 zil_lwb_dest(void *vbuf
, void *unused
)
2739 mutex_destroy(&lwb
->lwb_vdev_lock
);
2740 avl_destroy(&lwb
->lwb_vdev_tree
);
2741 list_destroy(&lwb
->lwb_waiters
);
2747 zil_lwb_cache
= kmem_cache_create("zil_lwb_cache",
2748 sizeof (lwb_t
), 0, zil_lwb_cons
, zil_lwb_dest
, NULL
, NULL
, NULL
, 0);
2750 zil_zcw_cache
= kmem_cache_create("zil_zcw_cache",
2751 sizeof (zil_commit_waiter_t
), 0, NULL
, NULL
, NULL
, NULL
, NULL
, 0);
2757 kmem_cache_destroy(zil_zcw_cache
);
2758 kmem_cache_destroy(zil_lwb_cache
);
2762 zil_set_sync(zilog_t
*zilog
, uint64_t sync
)
2764 zilog
->zl_sync
= sync
;
2768 zil_set_logbias(zilog_t
*zilog
, uint64_t logbias
)
2770 zilog
->zl_logbias
= logbias
;
2774 zil_alloc(objset_t
*os
, zil_header_t
*zh_phys
)
2778 zilog
= kmem_zalloc(sizeof (zilog_t
), KM_SLEEP
);
2780 zilog
->zl_header
= zh_phys
;
2782 zilog
->zl_spa
= dmu_objset_spa(os
);
2783 zilog
->zl_dmu_pool
= dmu_objset_pool(os
);
2784 zilog
->zl_destroy_txg
= TXG_INITIAL
- 1;
2785 zilog
->zl_logbias
= dmu_objset_logbias(os
);
2786 zilog
->zl_sync
= dmu_objset_syncprop(os
);
2787 zilog
->zl_dirty_max_txg
= 0;
2788 zilog
->zl_last_lwb_opened
= NULL
;
2789 zilog
->zl_last_lwb_latency
= 0;
2791 mutex_init(&zilog
->zl_lock
, NULL
, MUTEX_DEFAULT
, NULL
);
2792 mutex_init(&zilog
->zl_issuer_lock
, NULL
, MUTEX_DEFAULT
, NULL
);
2794 for (int i
= 0; i
< TXG_SIZE
; i
++) {
2795 mutex_init(&zilog
->zl_itxg
[i
].itxg_lock
, NULL
,
2796 MUTEX_DEFAULT
, NULL
);
2799 list_create(&zilog
->zl_lwb_list
, sizeof (lwb_t
),
2800 offsetof(lwb_t
, lwb_node
));
2802 list_create(&zilog
->zl_itx_commit_list
, sizeof (itx_t
),
2803 offsetof(itx_t
, itx_node
));
2805 cv_init(&zilog
->zl_cv_suspend
, NULL
, CV_DEFAULT
, NULL
);
2811 zil_free(zilog_t
*zilog
)
2813 zilog
->zl_stop_sync
= 1;
2815 ASSERT0(zilog
->zl_suspend
);
2816 ASSERT0(zilog
->zl_suspending
);
2818 ASSERT(list_is_empty(&zilog
->zl_lwb_list
));
2819 list_destroy(&zilog
->zl_lwb_list
);
2821 ASSERT(list_is_empty(&zilog
->zl_itx_commit_list
));
2822 list_destroy(&zilog
->zl_itx_commit_list
);
2824 for (int i
= 0; i
< TXG_SIZE
; i
++) {
2826 * It's possible for an itx to be generated that doesn't dirty
2827 * a txg (e.g. ztest TX_TRUNCATE). So there's no zil_clean()
2828 * callback to remove the entry. We remove those here.
2830 * Also free up the ziltest itxs.
2832 if (zilog
->zl_itxg
[i
].itxg_itxs
)
2833 zil_itxg_clean(zilog
->zl_itxg
[i
].itxg_itxs
);
2834 mutex_destroy(&zilog
->zl_itxg
[i
].itxg_lock
);
2837 mutex_destroy(&zilog
->zl_issuer_lock
);
2838 mutex_destroy(&zilog
->zl_lock
);
2840 cv_destroy(&zilog
->zl_cv_suspend
);
2842 kmem_free(zilog
, sizeof (zilog_t
));
2846 * Open an intent log.
2849 zil_open(objset_t
*os
, zil_get_data_t
*get_data
)
2851 zilog_t
*zilog
= dmu_objset_zil(os
);
2853 ASSERT3P(zilog
->zl_get_data
, ==, NULL
);
2854 ASSERT3P(zilog
->zl_last_lwb_opened
, ==, NULL
);
2855 ASSERT(list_is_empty(&zilog
->zl_lwb_list
));
2857 zilog
->zl_get_data
= get_data
;
2863 * Close an intent log.
2866 zil_close(zilog_t
*zilog
)
2871 if (!dmu_objset_is_snapshot(zilog
->zl_os
)) {
2872 zil_commit(zilog
, 0);
2874 ASSERT3P(list_tail(&zilog
->zl_lwb_list
), ==, NULL
);
2875 ASSERT0(zilog
->zl_dirty_max_txg
);
2876 ASSERT3B(zilog_is_dirty(zilog
), ==, B_FALSE
);
2879 mutex_enter(&zilog
->zl_lock
);
2880 lwb
= list_tail(&zilog
->zl_lwb_list
);
2882 txg
= zilog
->zl_dirty_max_txg
;
2884 txg
= MAX(zilog
->zl_dirty_max_txg
, lwb
->lwb_max_txg
);
2885 mutex_exit(&zilog
->zl_lock
);
2888 * We need to use txg_wait_synced() to wait long enough for the
2889 * ZIL to be clean, and to wait for all pending lwbs to be
2893 txg_wait_synced(zilog
->zl_dmu_pool
, txg
);
2895 if (zilog_is_dirty(zilog
))
2896 zfs_dbgmsg("zil (%p) is dirty, txg %llu", zilog
, txg
);
2897 VERIFY(!zilog_is_dirty(zilog
));
2899 zilog
->zl_get_data
= NULL
;
2902 * We should have only one lwb left on the list; remove it now.
2904 mutex_enter(&zilog
->zl_lock
);
2905 lwb
= list_head(&zilog
->zl_lwb_list
);
2907 ASSERT3P(lwb
, ==, list_tail(&zilog
->zl_lwb_list
));
2908 ASSERT3S(lwb
->lwb_state
, !=, LWB_STATE_ISSUED
);
2909 list_remove(&zilog
->zl_lwb_list
, lwb
);
2910 zio_buf_free(lwb
->lwb_buf
, lwb
->lwb_sz
);
2911 zil_free_lwb(zilog
, lwb
);
2913 mutex_exit(&zilog
->zl_lock
);
2916 static char *suspend_tag
= "zil suspending";
2919 * Suspend an intent log. While in suspended mode, we still honor
2920 * synchronous semantics, but we rely on txg_wait_synced() to do it.
2921 * On old version pools, we suspend the log briefly when taking a
2922 * snapshot so that it will have an empty intent log.
2924 * Long holds are not really intended to be used the way we do here --
2925 * held for such a short time. A concurrent caller of dsl_dataset_long_held()
2926 * could fail. Therefore we take pains to only put a long hold if it is
2927 * actually necessary. Fortunately, it will only be necessary if the
2928 * objset is currently mounted (or the ZVOL equivalent). In that case it
2929 * will already have a long hold, so we are not really making things any worse.
2931 * Ideally, we would locate the existing long-holder (i.e. the zfsvfs_t or
2932 * zvol_state_t), and use their mechanism to prevent their hold from being
2933 * dropped (e.g. VFS_HOLD()). However, that would be even more pain for
2936 * if cookiep == NULL, this does both the suspend & resume.
2937 * Otherwise, it returns with the dataset "long held", and the cookie
2938 * should be passed into zil_resume().
2941 zil_suspend(const char *osname
, void **cookiep
)
2945 const zil_header_t
*zh
;
2948 error
= dmu_objset_hold(osname
, suspend_tag
, &os
);
2951 zilog
= dmu_objset_zil(os
);
2953 mutex_enter(&zilog
->zl_lock
);
2954 zh
= zilog
->zl_header
;
2956 if (zh
->zh_flags
& ZIL_REPLAY_NEEDED
) { /* unplayed log */
2957 mutex_exit(&zilog
->zl_lock
);
2958 dmu_objset_rele(os
, suspend_tag
);
2959 return (SET_ERROR(EBUSY
));
2963 * Don't put a long hold in the cases where we can avoid it. This
2964 * is when there is no cookie so we are doing a suspend & resume
2965 * (i.e. called from zil_vdev_offline()), and there's nothing to do
2966 * for the suspend because it's already suspended, or there's no ZIL.
2968 if (cookiep
== NULL
&& !zilog
->zl_suspending
&&
2969 (zilog
->zl_suspend
> 0 || BP_IS_HOLE(&zh
->zh_log
))) {
2970 mutex_exit(&zilog
->zl_lock
);
2971 dmu_objset_rele(os
, suspend_tag
);
2975 dsl_dataset_long_hold(dmu_objset_ds(os
), suspend_tag
);
2976 dsl_pool_rele(dmu_objset_pool(os
), suspend_tag
);
2978 zilog
->zl_suspend
++;
2980 if (zilog
->zl_suspend
> 1) {
2982 * Someone else is already suspending it.
2983 * Just wait for them to finish.
2986 while (zilog
->zl_suspending
)
2987 cv_wait(&zilog
->zl_cv_suspend
, &zilog
->zl_lock
);
2988 mutex_exit(&zilog
->zl_lock
);
2990 if (cookiep
== NULL
)
2998 * If there is no pointer to an on-disk block, this ZIL must not
2999 * be active (e.g. filesystem not mounted), so there's nothing
3002 if (BP_IS_HOLE(&zh
->zh_log
)) {
3003 ASSERT(cookiep
!= NULL
); /* fast path already handled */
3006 mutex_exit(&zilog
->zl_lock
);
3010 zilog
->zl_suspending
= B_TRUE
;
3011 mutex_exit(&zilog
->zl_lock
);
3014 * We need to use zil_commit_impl to ensure we wait for all
3015 * LWB_STATE_OPENED and LWB_STATE_ISSUED lwb's to be committed
3016 * to disk before proceeding. If we used zil_commit instead, it
3017 * would just call txg_wait_synced(), because zl_suspend is set.
3018 * txg_wait_synced() doesn't wait for these lwb's to be
3019 * LWB_STATE_DONE before returning.
3021 zil_commit_impl(zilog
, 0);
3024 * Now that we've ensured all lwb's are LWB_STATE_DONE, we use
3025 * txg_wait_synced() to ensure the data from the zilog has
3026 * migrated to the main pool before calling zil_destroy().
3028 txg_wait_synced(zilog
->zl_dmu_pool
, 0);
3030 zil_destroy(zilog
, B_FALSE
);
3032 mutex_enter(&zilog
->zl_lock
);
3033 zilog
->zl_suspending
= B_FALSE
;
3034 cv_broadcast(&zilog
->zl_cv_suspend
);
3035 mutex_exit(&zilog
->zl_lock
);
3037 if (cookiep
== NULL
)
3045 zil_resume(void *cookie
)
3047 objset_t
*os
= cookie
;
3048 zilog_t
*zilog
= dmu_objset_zil(os
);
3050 mutex_enter(&zilog
->zl_lock
);
3051 ASSERT(zilog
->zl_suspend
!= 0);
3052 zilog
->zl_suspend
--;
3053 mutex_exit(&zilog
->zl_lock
);
3054 dsl_dataset_long_rele(dmu_objset_ds(os
), suspend_tag
);
3055 dsl_dataset_rele(dmu_objset_ds(os
), suspend_tag
);
3058 typedef struct zil_replay_arg
{
3059 zil_replay_func_t
**zr_replay
;
3061 boolean_t zr_byteswap
;
3066 zil_replay_error(zilog_t
*zilog
, lr_t
*lr
, int error
)
3068 char name
[ZFS_MAX_DATASET_NAME_LEN
];
3070 zilog
->zl_replaying_seq
--; /* didn't actually replay this one */
3072 dmu_objset_name(zilog
->zl_os
, name
);
3074 cmn_err(CE_WARN
, "ZFS replay transaction error %d, "
3075 "dataset %s, seq 0x%llx, txtype %llu %s\n", error
, name
,
3076 (u_longlong_t
)lr
->lrc_seq
,
3077 (u_longlong_t
)(lr
->lrc_txtype
& ~TX_CI
),
3078 (lr
->lrc_txtype
& TX_CI
) ? "CI" : "");
3084 zil_replay_log_record(zilog_t
*zilog
, lr_t
*lr
, void *zra
, uint64_t claim_txg
)
3086 zil_replay_arg_t
*zr
= zra
;
3087 const zil_header_t
*zh
= zilog
->zl_header
;
3088 uint64_t reclen
= lr
->lrc_reclen
;
3089 uint64_t txtype
= lr
->lrc_txtype
;
3092 zilog
->zl_replaying_seq
= lr
->lrc_seq
;
3094 if (lr
->lrc_seq
<= zh
->zh_replay_seq
) /* already replayed */
3097 if (lr
->lrc_txg
< claim_txg
) /* already committed */
3100 /* Strip case-insensitive bit, still present in log record */
3103 if (txtype
== 0 || txtype
>= TX_MAX_TYPE
)
3104 return (zil_replay_error(zilog
, lr
, EINVAL
));
3107 * If this record type can be logged out of order, the object
3108 * (lr_foid) may no longer exist. That's legitimate, not an error.
3110 if (TX_OOO(txtype
)) {
3111 error
= dmu_object_info(zilog
->zl_os
,
3112 ((lr_ooo_t
*)lr
)->lr_foid
, NULL
);
3113 if (error
== ENOENT
|| error
== EEXIST
)
3118 * Make a copy of the data so we can revise and extend it.
3120 bcopy(lr
, zr
->zr_lr
, reclen
);
3123 * If this is a TX_WRITE with a blkptr, suck in the data.
3125 if (txtype
== TX_WRITE
&& reclen
== sizeof (lr_write_t
)) {
3126 error
= zil_read_log_data(zilog
, (lr_write_t
*)lr
,
3127 zr
->zr_lr
+ reclen
);
3129 return (zil_replay_error(zilog
, lr
, error
));
3133 * The log block containing this lr may have been byteswapped
3134 * so that we can easily examine common fields like lrc_txtype.
3135 * However, the log is a mix of different record types, and only the
3136 * replay vectors know how to byteswap their records. Therefore, if
3137 * the lr was byteswapped, undo it before invoking the replay vector.
3139 if (zr
->zr_byteswap
)
3140 byteswap_uint64_array(zr
->zr_lr
, reclen
);
3143 * We must now do two things atomically: replay this log record,
3144 * and update the log header sequence number to reflect the fact that
3145 * we did so. At the end of each replay function the sequence number
3146 * is updated if we are in replay mode.
3148 error
= zr
->zr_replay
[txtype
](zr
->zr_arg
, zr
->zr_lr
, zr
->zr_byteswap
);
3151 * The DMU's dnode layer doesn't see removes until the txg
3152 * commits, so a subsequent claim can spuriously fail with
3153 * EEXIST. So if we receive any error we try syncing out
3154 * any removes then retry the transaction. Note that we
3155 * specify B_FALSE for byteswap now, so we don't do it twice.
3157 txg_wait_synced(spa_get_dsl(zilog
->zl_spa
), 0);
3158 error
= zr
->zr_replay
[txtype
](zr
->zr_arg
, zr
->zr_lr
, B_FALSE
);
3160 return (zil_replay_error(zilog
, lr
, error
));
3167 zil_incr_blks(zilog_t
*zilog
, blkptr_t
*bp
, void *arg
, uint64_t claim_txg
)
3169 zilog
->zl_replay_blks
++;
3175 * If this dataset has a non-empty intent log, replay it and destroy it.
3178 zil_replay(objset_t
*os
, void *arg
, zil_replay_func_t
*replay_func
[TX_MAX_TYPE
])
3180 zilog_t
*zilog
= dmu_objset_zil(os
);
3181 const zil_header_t
*zh
= zilog
->zl_header
;
3182 zil_replay_arg_t zr
;
3184 if ((zh
->zh_flags
& ZIL_REPLAY_NEEDED
) == 0) {
3185 zil_destroy(zilog
, B_TRUE
);
3189 zr
.zr_replay
= replay_func
;
3191 zr
.zr_byteswap
= BP_SHOULD_BYTESWAP(&zh
->zh_log
);
3192 zr
.zr_lr
= kmem_alloc(2 * SPA_MAXBLOCKSIZE
, KM_SLEEP
);
3195 * Wait for in-progress removes to sync before starting replay.
3197 txg_wait_synced(zilog
->zl_dmu_pool
, 0);
3199 zilog
->zl_replay
= B_TRUE
;
3200 zilog
->zl_replay_time
= ddi_get_lbolt();
3201 ASSERT(zilog
->zl_replay_blks
== 0);
3202 (void) zil_parse(zilog
, zil_incr_blks
, zil_replay_log_record
, &zr
,
3204 kmem_free(zr
.zr_lr
, 2 * SPA_MAXBLOCKSIZE
);
3206 zil_destroy(zilog
, B_FALSE
);
3207 txg_wait_synced(zilog
->zl_dmu_pool
, zilog
->zl_destroy_txg
);
3208 zilog
->zl_replay
= B_FALSE
;
3212 zil_replaying(zilog_t
*zilog
, dmu_tx_t
*tx
)
3214 if (zilog
->zl_sync
== ZFS_SYNC_DISABLED
)
3217 if (zilog
->zl_replay
) {
3218 dsl_dataset_dirty(dmu_objset_ds(zilog
->zl_os
), tx
);
3219 zilog
->zl_replayed_seq
[dmu_tx_get_txg(tx
) & TXG_MASK
] =
3220 zilog
->zl_replaying_seq
;
3229 zil_vdev_offline(const char *osname
, void *arg
)
3233 error
= zil_suspend(osname
, NULL
);
3235 return (SET_ERROR(EEXIST
));