4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2011, 2018 by Delphix. All rights reserved.
24 * Copyright (c) 2014 Integros [integros.com]
25 * Copyright (c) 2018 Datto Inc.
28 /* Portions Copyright 2010 Robert Milkowski */
30 #include <sys/zfs_context.h>
32 #include <sys/spa_impl.h>
38 #include <sys/zil_impl.h>
39 #include <sys/dsl_dataset.h>
40 #include <sys/vdev_impl.h>
41 #include <sys/dmu_tx.h>
42 #include <sys/dsl_pool.h>
43 #include <sys/metaslab.h>
44 #include <sys/trace_zfs.h>
48 * The ZFS Intent Log (ZIL) saves "transaction records" (itxs) of system
49 * calls that change the file system. Each itx has enough information to
50 * be able to replay them after a system crash, power loss, or
51 * equivalent failure mode. These are stored in memory until either:
53 * 1. they are committed to the pool by the DMU transaction group
54 * (txg), at which point they can be discarded; or
55 * 2. they are committed to the on-disk ZIL for the dataset being
56 * modified (e.g. due to an fsync, O_DSYNC, or other synchronous
59 * In the event of a crash or power loss, the itxs contained by each
60 * dataset's on-disk ZIL will be replayed when that dataset is first
61 * instantiated (e.g. if the dataset is a normal filesystem, when it is
64 * As hinted at above, there is one ZIL per dataset (both the in-memory
65 * representation, and the on-disk representation). The on-disk format
66 * consists of 3 parts:
68 * - a single, per-dataset, ZIL header; which points to a chain of
69 * - zero or more ZIL blocks; each of which contains
70 * - zero or more ZIL records
72 * A ZIL record holds the information necessary to replay a single
73 * system call transaction. A ZIL block can hold many ZIL records, and
74 * the blocks are chained together, similarly to a singly linked list.
76 * Each ZIL block contains a block pointer (blkptr_t) to the next ZIL
77 * block in the chain, and the ZIL header points to the first block in
80 * Note, there is not a fixed place in the pool to hold these ZIL
81 * blocks; they are dynamically allocated and freed as needed from the
82 * blocks available on the pool, though they can be preferentially
83 * allocated from a dedicated "log" vdev.
87 * This controls the amount of time that a ZIL block (lwb) will remain
88 * "open" when it isn't "full", and it has a thread waiting for it to be
89 * committed to stable storage. Please refer to the zil_commit_waiter()
90 * function (and the comments within it) for more details.
92 static int zfs_commit_timeout_pct
= 5;
95 * See zil.h for more information about these fields.
97 static zil_stats_t zil_stats
= {
98 { "zil_commit_count", KSTAT_DATA_UINT64
},
99 { "zil_commit_writer_count", KSTAT_DATA_UINT64
},
100 { "zil_itx_count", KSTAT_DATA_UINT64
},
101 { "zil_itx_indirect_count", KSTAT_DATA_UINT64
},
102 { "zil_itx_indirect_bytes", KSTAT_DATA_UINT64
},
103 { "zil_itx_copied_count", KSTAT_DATA_UINT64
},
104 { "zil_itx_copied_bytes", KSTAT_DATA_UINT64
},
105 { "zil_itx_needcopy_count", KSTAT_DATA_UINT64
},
106 { "zil_itx_needcopy_bytes", KSTAT_DATA_UINT64
},
107 { "zil_itx_metaslab_normal_count", KSTAT_DATA_UINT64
},
108 { "zil_itx_metaslab_normal_bytes", KSTAT_DATA_UINT64
},
109 { "zil_itx_metaslab_slog_count", KSTAT_DATA_UINT64
},
110 { "zil_itx_metaslab_slog_bytes", KSTAT_DATA_UINT64
},
113 static kstat_t
*zil_ksp
;
116 * Disable intent logging replay. This global ZIL switch affects all pools.
118 int zil_replay_disable
= 0;
121 * Disable the DKIOCFLUSHWRITECACHE commands that are normally sent to
122 * the disk(s) by the ZIL after an LWB write has completed. Setting this
123 * will cause ZIL corruption on power loss if a volatile out-of-order
124 * write cache is enabled.
126 static int zil_nocacheflush
= 0;
129 * Limit SLOG write size per commit executed with synchronous priority.
130 * Any writes above that will be executed with lower (asynchronous) priority
131 * to limit potential SLOG device abuse by single active ZIL writer.
133 static unsigned long zil_slog_bulk
= 768 * 1024;
135 static kmem_cache_t
*zil_lwb_cache
;
136 static kmem_cache_t
*zil_zcw_cache
;
138 #define LWB_EMPTY(lwb) ((BP_GET_LSIZE(&lwb->lwb_blk) - \
139 sizeof (zil_chain_t)) == (lwb->lwb_sz - lwb->lwb_nused))
142 zil_bp_compare(const void *x1
, const void *x2
)
144 const dva_t
*dva1
= &((zil_bp_node_t
*)x1
)->zn_dva
;
145 const dva_t
*dva2
= &((zil_bp_node_t
*)x2
)->zn_dva
;
147 int cmp
= TREE_CMP(DVA_GET_VDEV(dva1
), DVA_GET_VDEV(dva2
));
151 return (TREE_CMP(DVA_GET_OFFSET(dva1
), DVA_GET_OFFSET(dva2
)));
155 zil_bp_tree_init(zilog_t
*zilog
)
157 avl_create(&zilog
->zl_bp_tree
, zil_bp_compare
,
158 sizeof (zil_bp_node_t
), offsetof(zil_bp_node_t
, zn_node
));
162 zil_bp_tree_fini(zilog_t
*zilog
)
164 avl_tree_t
*t
= &zilog
->zl_bp_tree
;
168 while ((zn
= avl_destroy_nodes(t
, &cookie
)) != NULL
)
169 kmem_free(zn
, sizeof (zil_bp_node_t
));
175 zil_bp_tree_add(zilog_t
*zilog
, const blkptr_t
*bp
)
177 avl_tree_t
*t
= &zilog
->zl_bp_tree
;
182 if (BP_IS_EMBEDDED(bp
))
185 dva
= BP_IDENTITY(bp
);
187 if (avl_find(t
, dva
, &where
) != NULL
)
188 return (SET_ERROR(EEXIST
));
190 zn
= kmem_alloc(sizeof (zil_bp_node_t
), KM_SLEEP
);
192 avl_insert(t
, zn
, where
);
197 static zil_header_t
*
198 zil_header_in_syncing_context(zilog_t
*zilog
)
200 return ((zil_header_t
*)zilog
->zl_header
);
204 zil_init_log_chain(zilog_t
*zilog
, blkptr_t
*bp
)
206 zio_cksum_t
*zc
= &bp
->blk_cksum
;
208 (void) random_get_pseudo_bytes((void *)&zc
->zc_word
[ZIL_ZC_GUID_0
],
209 sizeof (zc
->zc_word
[ZIL_ZC_GUID_0
]));
210 (void) random_get_pseudo_bytes((void *)&zc
->zc_word
[ZIL_ZC_GUID_1
],
211 sizeof (zc
->zc_word
[ZIL_ZC_GUID_1
]));
212 zc
->zc_word
[ZIL_ZC_OBJSET
] = dmu_objset_id(zilog
->zl_os
);
213 zc
->zc_word
[ZIL_ZC_SEQ
] = 1ULL;
217 * Read a log block and make sure it's valid.
220 zil_read_log_block(zilog_t
*zilog
, boolean_t decrypt
, const blkptr_t
*bp
,
221 blkptr_t
*nbp
, void *dst
, char **end
)
223 enum zio_flag zio_flags
= ZIO_FLAG_CANFAIL
;
224 arc_flags_t aflags
= ARC_FLAG_WAIT
;
225 arc_buf_t
*abuf
= NULL
;
229 if (zilog
->zl_header
->zh_claim_txg
== 0)
230 zio_flags
|= ZIO_FLAG_SPECULATIVE
| ZIO_FLAG_SCRUB
;
232 if (!(zilog
->zl_header
->zh_flags
& ZIL_CLAIM_LR_SEQ_VALID
))
233 zio_flags
|= ZIO_FLAG_SPECULATIVE
;
236 zio_flags
|= ZIO_FLAG_RAW
;
238 SET_BOOKMARK(&zb
, bp
->blk_cksum
.zc_word
[ZIL_ZC_OBJSET
],
239 ZB_ZIL_OBJECT
, ZB_ZIL_LEVEL
, bp
->blk_cksum
.zc_word
[ZIL_ZC_SEQ
]);
241 error
= arc_read(NULL
, zilog
->zl_spa
, bp
, arc_getbuf_func
,
242 &abuf
, ZIO_PRIORITY_SYNC_READ
, zio_flags
, &aflags
, &zb
);
245 zio_cksum_t cksum
= bp
->blk_cksum
;
248 * Validate the checksummed log block.
250 * Sequence numbers should be... sequential. The checksum
251 * verifier for the next block should be bp's checksum plus 1.
253 * Also check the log chain linkage and size used.
255 cksum
.zc_word
[ZIL_ZC_SEQ
]++;
257 if (BP_GET_CHECKSUM(bp
) == ZIO_CHECKSUM_ZILOG2
) {
258 zil_chain_t
*zilc
= abuf
->b_data
;
259 char *lr
= (char *)(zilc
+ 1);
260 uint64_t len
= zilc
->zc_nused
- sizeof (zil_chain_t
);
262 if (memcmp(&cksum
, &zilc
->zc_next_blk
.blk_cksum
,
263 sizeof (cksum
)) || BP_IS_HOLE(&zilc
->zc_next_blk
)) {
264 error
= SET_ERROR(ECKSUM
);
266 ASSERT3U(len
, <=, SPA_OLD_MAXBLOCKSIZE
);
267 memcpy(dst
, lr
, len
);
268 *end
= (char *)dst
+ len
;
269 *nbp
= zilc
->zc_next_blk
;
272 char *lr
= abuf
->b_data
;
273 uint64_t size
= BP_GET_LSIZE(bp
);
274 zil_chain_t
*zilc
= (zil_chain_t
*)(lr
+ size
) - 1;
276 if (memcmp(&cksum
, &zilc
->zc_next_blk
.blk_cksum
,
277 sizeof (cksum
)) || BP_IS_HOLE(&zilc
->zc_next_blk
) ||
278 (zilc
->zc_nused
> (size
- sizeof (*zilc
)))) {
279 error
= SET_ERROR(ECKSUM
);
281 ASSERT3U(zilc
->zc_nused
, <=,
282 SPA_OLD_MAXBLOCKSIZE
);
283 memcpy(dst
, lr
, zilc
->zc_nused
);
284 *end
= (char *)dst
+ zilc
->zc_nused
;
285 *nbp
= zilc
->zc_next_blk
;
289 arc_buf_destroy(abuf
, &abuf
);
296 * Read a TX_WRITE log data block.
299 zil_read_log_data(zilog_t
*zilog
, const lr_write_t
*lr
, void *wbuf
)
301 enum zio_flag zio_flags
= ZIO_FLAG_CANFAIL
;
302 const blkptr_t
*bp
= &lr
->lr_blkptr
;
303 arc_flags_t aflags
= ARC_FLAG_WAIT
;
304 arc_buf_t
*abuf
= NULL
;
308 if (BP_IS_HOLE(bp
)) {
310 memset(wbuf
, 0, MAX(BP_GET_LSIZE(bp
), lr
->lr_length
));
314 if (zilog
->zl_header
->zh_claim_txg
== 0)
315 zio_flags
|= ZIO_FLAG_SPECULATIVE
| ZIO_FLAG_SCRUB
;
318 * If we are not using the resulting data, we are just checking that
319 * it hasn't been corrupted so we don't need to waste CPU time
320 * decompressing and decrypting it.
323 zio_flags
|= ZIO_FLAG_RAW
;
325 SET_BOOKMARK(&zb
, dmu_objset_id(zilog
->zl_os
), lr
->lr_foid
,
326 ZB_ZIL_LEVEL
, lr
->lr_offset
/ BP_GET_LSIZE(bp
));
328 error
= arc_read(NULL
, zilog
->zl_spa
, bp
, arc_getbuf_func
, &abuf
,
329 ZIO_PRIORITY_SYNC_READ
, zio_flags
, &aflags
, &zb
);
333 memcpy(wbuf
, abuf
->b_data
, arc_buf_size(abuf
));
334 arc_buf_destroy(abuf
, &abuf
);
341 * Parse the intent log, and call parse_func for each valid record within.
344 zil_parse(zilog_t
*zilog
, zil_parse_blk_func_t
*parse_blk_func
,
345 zil_parse_lr_func_t
*parse_lr_func
, void *arg
, uint64_t txg
,
348 const zil_header_t
*zh
= zilog
->zl_header
;
349 boolean_t claimed
= !!zh
->zh_claim_txg
;
350 uint64_t claim_blk_seq
= claimed
? zh
->zh_claim_blk_seq
: UINT64_MAX
;
351 uint64_t claim_lr_seq
= claimed
? zh
->zh_claim_lr_seq
: UINT64_MAX
;
352 uint64_t max_blk_seq
= 0;
353 uint64_t max_lr_seq
= 0;
354 uint64_t blk_count
= 0;
355 uint64_t lr_count
= 0;
356 blkptr_t blk
, next_blk
= {{{{0}}}};
361 * Old logs didn't record the maximum zh_claim_lr_seq.
363 if (!(zh
->zh_flags
& ZIL_CLAIM_LR_SEQ_VALID
))
364 claim_lr_seq
= UINT64_MAX
;
367 * Starting at the block pointed to by zh_log we read the log chain.
368 * For each block in the chain we strongly check that block to
369 * ensure its validity. We stop when an invalid block is found.
370 * For each block pointer in the chain we call parse_blk_func().
371 * For each record in each valid block we call parse_lr_func().
372 * If the log has been claimed, stop if we encounter a sequence
373 * number greater than the highest claimed sequence number.
375 lrbuf
= zio_buf_alloc(SPA_OLD_MAXBLOCKSIZE
);
376 zil_bp_tree_init(zilog
);
378 for (blk
= zh
->zh_log
; !BP_IS_HOLE(&blk
); blk
= next_blk
) {
379 uint64_t blk_seq
= blk
.blk_cksum
.zc_word
[ZIL_ZC_SEQ
];
383 if (blk_seq
> claim_blk_seq
)
386 error
= parse_blk_func(zilog
, &blk
, arg
, txg
);
389 ASSERT3U(max_blk_seq
, <, blk_seq
);
390 max_blk_seq
= blk_seq
;
393 if (max_lr_seq
== claim_lr_seq
&& max_blk_seq
== claim_blk_seq
)
396 error
= zil_read_log_block(zilog
, decrypt
, &blk
, &next_blk
,
401 for (lrp
= lrbuf
; lrp
< end
; lrp
+= reclen
) {
402 lr_t
*lr
= (lr_t
*)lrp
;
403 reclen
= lr
->lrc_reclen
;
404 ASSERT3U(reclen
, >=, sizeof (lr_t
));
405 if (lr
->lrc_seq
> claim_lr_seq
)
408 error
= parse_lr_func(zilog
, lr
, arg
, txg
);
411 ASSERT3U(max_lr_seq
, <, lr
->lrc_seq
);
412 max_lr_seq
= lr
->lrc_seq
;
417 zilog
->zl_parse_error
= error
;
418 zilog
->zl_parse_blk_seq
= max_blk_seq
;
419 zilog
->zl_parse_lr_seq
= max_lr_seq
;
420 zilog
->zl_parse_blk_count
= blk_count
;
421 zilog
->zl_parse_lr_count
= lr_count
;
423 ASSERT(!claimed
|| !(zh
->zh_flags
& ZIL_CLAIM_LR_SEQ_VALID
) ||
424 (max_blk_seq
== claim_blk_seq
&& max_lr_seq
== claim_lr_seq
) ||
425 (decrypt
&& error
== EIO
));
427 zil_bp_tree_fini(zilog
);
428 zio_buf_free(lrbuf
, SPA_OLD_MAXBLOCKSIZE
);
434 zil_clear_log_block(zilog_t
*zilog
, const blkptr_t
*bp
, void *tx
,
438 ASSERT(!BP_IS_HOLE(bp
));
441 * As we call this function from the context of a rewind to a
442 * checkpoint, each ZIL block whose txg is later than the txg
443 * that we rewind to is invalid. Thus, we return -1 so
444 * zil_parse() doesn't attempt to read it.
446 if (bp
->blk_birth
>= first_txg
)
449 if (zil_bp_tree_add(zilog
, bp
) != 0)
452 zio_free(zilog
->zl_spa
, first_txg
, bp
);
457 zil_noop_log_record(zilog_t
*zilog
, const lr_t
*lrc
, void *tx
,
460 (void) zilog
, (void) lrc
, (void) tx
, (void) first_txg
;
465 zil_claim_log_block(zilog_t
*zilog
, const blkptr_t
*bp
, void *tx
,
469 * Claim log block if not already committed and not already claimed.
470 * If tx == NULL, just verify that the block is claimable.
472 if (BP_IS_HOLE(bp
) || bp
->blk_birth
< first_txg
||
473 zil_bp_tree_add(zilog
, bp
) != 0)
476 return (zio_wait(zio_claim(NULL
, zilog
->zl_spa
,
477 tx
== NULL
? 0 : first_txg
, bp
, spa_claim_notify
, NULL
,
478 ZIO_FLAG_CANFAIL
| ZIO_FLAG_SPECULATIVE
| ZIO_FLAG_SCRUB
)));
482 zil_claim_log_record(zilog_t
*zilog
, const lr_t
*lrc
, void *tx
,
485 lr_write_t
*lr
= (lr_write_t
*)lrc
;
488 if (lrc
->lrc_txtype
!= TX_WRITE
)
492 * If the block is not readable, don't claim it. This can happen
493 * in normal operation when a log block is written to disk before
494 * some of the dmu_sync() blocks it points to. In this case, the
495 * transaction cannot have been committed to anyone (we would have
496 * waited for all writes to be stable first), so it is semantically
497 * correct to declare this the end of the log.
499 if (lr
->lr_blkptr
.blk_birth
>= first_txg
) {
500 error
= zil_read_log_data(zilog
, lr
, NULL
);
505 return (zil_claim_log_block(zilog
, &lr
->lr_blkptr
, tx
, first_txg
));
509 zil_free_log_block(zilog_t
*zilog
, const blkptr_t
*bp
, void *tx
,
514 zio_free(zilog
->zl_spa
, dmu_tx_get_txg(tx
), bp
);
520 zil_free_log_record(zilog_t
*zilog
, const lr_t
*lrc
, void *tx
,
523 lr_write_t
*lr
= (lr_write_t
*)lrc
;
524 blkptr_t
*bp
= &lr
->lr_blkptr
;
527 * If we previously claimed it, we need to free it.
529 if (claim_txg
!= 0 && lrc
->lrc_txtype
== TX_WRITE
&&
530 bp
->blk_birth
>= claim_txg
&& zil_bp_tree_add(zilog
, bp
) == 0 &&
532 zio_free(zilog
->zl_spa
, dmu_tx_get_txg(tx
), bp
);
538 zil_lwb_vdev_compare(const void *x1
, const void *x2
)
540 const uint64_t v1
= ((zil_vdev_node_t
*)x1
)->zv_vdev
;
541 const uint64_t v2
= ((zil_vdev_node_t
*)x2
)->zv_vdev
;
543 return (TREE_CMP(v1
, v2
));
547 zil_alloc_lwb(zilog_t
*zilog
, blkptr_t
*bp
, boolean_t slog
, uint64_t txg
,
552 lwb
= kmem_cache_alloc(zil_lwb_cache
, KM_SLEEP
);
553 lwb
->lwb_zilog
= zilog
;
555 lwb
->lwb_fastwrite
= fastwrite
;
556 lwb
->lwb_slog
= slog
;
557 lwb
->lwb_state
= LWB_STATE_CLOSED
;
558 lwb
->lwb_buf
= zio_buf_alloc(BP_GET_LSIZE(bp
));
559 lwb
->lwb_max_txg
= txg
;
560 lwb
->lwb_write_zio
= NULL
;
561 lwb
->lwb_root_zio
= NULL
;
563 lwb
->lwb_issued_timestamp
= 0;
564 if (BP_GET_CHECKSUM(bp
) == ZIO_CHECKSUM_ZILOG2
) {
565 lwb
->lwb_nused
= sizeof (zil_chain_t
);
566 lwb
->lwb_sz
= BP_GET_LSIZE(bp
);
569 lwb
->lwb_sz
= BP_GET_LSIZE(bp
) - sizeof (zil_chain_t
);
572 mutex_enter(&zilog
->zl_lock
);
573 list_insert_tail(&zilog
->zl_lwb_list
, lwb
);
574 mutex_exit(&zilog
->zl_lock
);
576 ASSERT(!MUTEX_HELD(&lwb
->lwb_vdev_lock
));
577 ASSERT(avl_is_empty(&lwb
->lwb_vdev_tree
));
578 VERIFY(list_is_empty(&lwb
->lwb_waiters
));
579 VERIFY(list_is_empty(&lwb
->lwb_itxs
));
585 zil_free_lwb(zilog_t
*zilog
, lwb_t
*lwb
)
587 ASSERT(MUTEX_HELD(&zilog
->zl_lock
));
588 ASSERT(!MUTEX_HELD(&lwb
->lwb_vdev_lock
));
589 VERIFY(list_is_empty(&lwb
->lwb_waiters
));
590 VERIFY(list_is_empty(&lwb
->lwb_itxs
));
591 ASSERT(avl_is_empty(&lwb
->lwb_vdev_tree
));
592 ASSERT3P(lwb
->lwb_write_zio
, ==, NULL
);
593 ASSERT3P(lwb
->lwb_root_zio
, ==, NULL
);
594 ASSERT3U(lwb
->lwb_max_txg
, <=, spa_syncing_txg(zilog
->zl_spa
));
595 ASSERT(lwb
->lwb_state
== LWB_STATE_CLOSED
||
596 lwb
->lwb_state
== LWB_STATE_FLUSH_DONE
);
599 * Clear the zilog's field to indicate this lwb is no longer
600 * valid, and prevent use-after-free errors.
602 if (zilog
->zl_last_lwb_opened
== lwb
)
603 zilog
->zl_last_lwb_opened
= NULL
;
605 kmem_cache_free(zil_lwb_cache
, lwb
);
609 * Called when we create in-memory log transactions so that we know
610 * to cleanup the itxs at the end of spa_sync().
613 zilog_dirty(zilog_t
*zilog
, uint64_t txg
)
615 dsl_pool_t
*dp
= zilog
->zl_dmu_pool
;
616 dsl_dataset_t
*ds
= dmu_objset_ds(zilog
->zl_os
);
618 ASSERT(spa_writeable(zilog
->zl_spa
));
620 if (ds
->ds_is_snapshot
)
621 panic("dirtying snapshot!");
623 if (txg_list_add(&dp
->dp_dirty_zilogs
, zilog
, txg
)) {
624 /* up the hold count until we can be written out */
625 dmu_buf_add_ref(ds
->ds_dbuf
, zilog
);
627 zilog
->zl_dirty_max_txg
= MAX(txg
, zilog
->zl_dirty_max_txg
);
632 * Determine if the zil is dirty in the specified txg. Callers wanting to
633 * ensure that the dirty state does not change must hold the itxg_lock for
634 * the specified txg. Holding the lock will ensure that the zil cannot be
635 * dirtied (zil_itx_assign) or cleaned (zil_clean) while we check its current
638 static boolean_t __maybe_unused
639 zilog_is_dirty_in_txg(zilog_t
*zilog
, uint64_t txg
)
641 dsl_pool_t
*dp
= zilog
->zl_dmu_pool
;
643 if (txg_list_member(&dp
->dp_dirty_zilogs
, zilog
, txg
& TXG_MASK
))
649 * Determine if the zil is dirty. The zil is considered dirty if it has
650 * any pending itx records that have not been cleaned by zil_clean().
653 zilog_is_dirty(zilog_t
*zilog
)
655 dsl_pool_t
*dp
= zilog
->zl_dmu_pool
;
657 for (int t
= 0; t
< TXG_SIZE
; t
++) {
658 if (txg_list_member(&dp
->dp_dirty_zilogs
, zilog
, t
))
665 * Its called in zil_commit context (zil_process_commit_list()/zil_create()).
666 * It activates SPA_FEATURE_ZILSAXATTR feature, if its enabled.
667 * Check dsl_dataset_feature_is_active to avoid txg_wait_synced() on every
671 zil_commit_activate_saxattr_feature(zilog_t
*zilog
)
673 dsl_dataset_t
*ds
= dmu_objset_ds(zilog
->zl_os
);
677 if (spa_feature_is_enabled(zilog
->zl_spa
,
678 SPA_FEATURE_ZILSAXATTR
) &&
679 dmu_objset_type(zilog
->zl_os
) != DMU_OST_ZVOL
&&
680 !dsl_dataset_feature_is_active(ds
,
681 SPA_FEATURE_ZILSAXATTR
)) {
682 tx
= dmu_tx_create(zilog
->zl_os
);
683 VERIFY0(dmu_tx_assign(tx
, TXG_WAIT
));
684 dsl_dataset_dirty(ds
, tx
);
685 txg
= dmu_tx_get_txg(tx
);
687 mutex_enter(&ds
->ds_lock
);
688 ds
->ds_feature_activation
[SPA_FEATURE_ZILSAXATTR
] =
690 mutex_exit(&ds
->ds_lock
);
692 txg_wait_synced(zilog
->zl_dmu_pool
, txg
);
697 * Create an on-disk intent log.
700 zil_create(zilog_t
*zilog
)
702 const zil_header_t
*zh
= zilog
->zl_header
;
708 boolean_t fastwrite
= FALSE
;
709 boolean_t slog
= FALSE
;
710 dsl_dataset_t
*ds
= dmu_objset_ds(zilog
->zl_os
);
714 * Wait for any previous destroy to complete.
716 txg_wait_synced(zilog
->zl_dmu_pool
, zilog
->zl_destroy_txg
);
718 ASSERT(zh
->zh_claim_txg
== 0);
719 ASSERT(zh
->zh_replay_seq
== 0);
724 * Allocate an initial log block if:
725 * - there isn't one already
726 * - the existing block is the wrong endianness
728 if (BP_IS_HOLE(&blk
) || BP_SHOULD_BYTESWAP(&blk
)) {
729 tx
= dmu_tx_create(zilog
->zl_os
);
730 VERIFY0(dmu_tx_assign(tx
, TXG_WAIT
));
731 dsl_dataset_dirty(dmu_objset_ds(zilog
->zl_os
), tx
);
732 txg
= dmu_tx_get_txg(tx
);
734 if (!BP_IS_HOLE(&blk
)) {
735 zio_free(zilog
->zl_spa
, txg
, &blk
);
739 error
= zio_alloc_zil(zilog
->zl_spa
, zilog
->zl_os
, txg
, &blk
,
740 ZIL_MIN_BLKSZ
, &slog
);
744 zil_init_log_chain(zilog
, &blk
);
748 * Allocate a log write block (lwb) for the first log block.
751 lwb
= zil_alloc_lwb(zilog
, &blk
, slog
, txg
, fastwrite
);
754 * If we just allocated the first log block, commit our transaction
755 * and wait for zil_sync() to stuff the block pointer into zh_log.
756 * (zh is part of the MOS, so we cannot modify it in open context.)
760 * If "zilsaxattr" feature is enabled on zpool, then activate
761 * it now when we're creating the ZIL chain. We can't wait with
762 * this until we write the first xattr log record because we
763 * need to wait for the feature activation to sync out.
765 if (spa_feature_is_enabled(zilog
->zl_spa
,
766 SPA_FEATURE_ZILSAXATTR
) && dmu_objset_type(zilog
->zl_os
) !=
768 mutex_enter(&ds
->ds_lock
);
769 ds
->ds_feature_activation
[SPA_FEATURE_ZILSAXATTR
] =
771 mutex_exit(&ds
->ds_lock
);
775 txg_wait_synced(zilog
->zl_dmu_pool
, txg
);
778 * This branch covers the case where we enable the feature on a
779 * zpool that has existing ZIL headers.
781 zil_commit_activate_saxattr_feature(zilog
);
783 IMPLY(spa_feature_is_enabled(zilog
->zl_spa
, SPA_FEATURE_ZILSAXATTR
) &&
784 dmu_objset_type(zilog
->zl_os
) != DMU_OST_ZVOL
,
785 dsl_dataset_feature_is_active(ds
, SPA_FEATURE_ZILSAXATTR
));
787 ASSERT(error
!= 0 || memcmp(&blk
, &zh
->zh_log
, sizeof (blk
)) == 0);
788 IMPLY(error
== 0, lwb
!= NULL
);
794 * In one tx, free all log blocks and clear the log header. If keep_first
795 * is set, then we're replaying a log with no content. We want to keep the
796 * first block, however, so that the first synchronous transaction doesn't
797 * require a txg_wait_synced() in zil_create(). We don't need to
798 * txg_wait_synced() here either when keep_first is set, because both
799 * zil_create() and zil_destroy() will wait for any in-progress destroys
803 zil_destroy(zilog_t
*zilog
, boolean_t keep_first
)
805 const zil_header_t
*zh
= zilog
->zl_header
;
811 * Wait for any previous destroy to complete.
813 txg_wait_synced(zilog
->zl_dmu_pool
, zilog
->zl_destroy_txg
);
815 zilog
->zl_old_header
= *zh
; /* debugging aid */
817 if (BP_IS_HOLE(&zh
->zh_log
))
820 tx
= dmu_tx_create(zilog
->zl_os
);
821 VERIFY0(dmu_tx_assign(tx
, TXG_WAIT
));
822 dsl_dataset_dirty(dmu_objset_ds(zilog
->zl_os
), tx
);
823 txg
= dmu_tx_get_txg(tx
);
825 mutex_enter(&zilog
->zl_lock
);
827 ASSERT3U(zilog
->zl_destroy_txg
, <, txg
);
828 zilog
->zl_destroy_txg
= txg
;
829 zilog
->zl_keep_first
= keep_first
;
831 if (!list_is_empty(&zilog
->zl_lwb_list
)) {
832 ASSERT(zh
->zh_claim_txg
== 0);
834 while ((lwb
= list_head(&zilog
->zl_lwb_list
)) != NULL
) {
835 if (lwb
->lwb_fastwrite
)
836 metaslab_fastwrite_unmark(zilog
->zl_spa
,
839 list_remove(&zilog
->zl_lwb_list
, lwb
);
840 if (lwb
->lwb_buf
!= NULL
)
841 zio_buf_free(lwb
->lwb_buf
, lwb
->lwb_sz
);
842 zio_free(zilog
->zl_spa
, txg
, &lwb
->lwb_blk
);
843 zil_free_lwb(zilog
, lwb
);
845 } else if (!keep_first
) {
846 zil_destroy_sync(zilog
, tx
);
848 mutex_exit(&zilog
->zl_lock
);
854 zil_destroy_sync(zilog_t
*zilog
, dmu_tx_t
*tx
)
856 ASSERT(list_is_empty(&zilog
->zl_lwb_list
));
857 (void) zil_parse(zilog
, zil_free_log_block
,
858 zil_free_log_record
, tx
, zilog
->zl_header
->zh_claim_txg
, B_FALSE
);
862 zil_claim(dsl_pool_t
*dp
, dsl_dataset_t
*ds
, void *txarg
)
864 dmu_tx_t
*tx
= txarg
;
871 error
= dmu_objset_own_obj(dp
, ds
->ds_object
,
872 DMU_OST_ANY
, B_FALSE
, B_FALSE
, FTAG
, &os
);
875 * EBUSY indicates that the objset is inconsistent, in which
876 * case it can not have a ZIL.
878 if (error
!= EBUSY
) {
879 cmn_err(CE_WARN
, "can't open objset for %llu, error %u",
880 (unsigned long long)ds
->ds_object
, error
);
886 zilog
= dmu_objset_zil(os
);
887 zh
= zil_header_in_syncing_context(zilog
);
888 ASSERT3U(tx
->tx_txg
, ==, spa_first_txg(zilog
->zl_spa
));
889 first_txg
= spa_min_claim_txg(zilog
->zl_spa
);
892 * If the spa_log_state is not set to be cleared, check whether
893 * the current uberblock is a checkpoint one and if the current
894 * header has been claimed before moving on.
896 * If the current uberblock is a checkpointed uberblock then
897 * one of the following scenarios took place:
899 * 1] We are currently rewinding to the checkpoint of the pool.
900 * 2] We crashed in the middle of a checkpoint rewind but we
901 * did manage to write the checkpointed uberblock to the
902 * vdev labels, so when we tried to import the pool again
903 * the checkpointed uberblock was selected from the import
906 * In both cases we want to zero out all the ZIL blocks, except
907 * the ones that have been claimed at the time of the checkpoint
908 * (their zh_claim_txg != 0). The reason is that these blocks
909 * may be corrupted since we may have reused their locations on
910 * disk after we took the checkpoint.
912 * We could try to set spa_log_state to SPA_LOG_CLEAR earlier
913 * when we first figure out whether the current uberblock is
914 * checkpointed or not. Unfortunately, that would discard all
915 * the logs, including the ones that are claimed, and we would
918 if (spa_get_log_state(zilog
->zl_spa
) == SPA_LOG_CLEAR
||
919 (zilog
->zl_spa
->spa_uberblock
.ub_checkpoint_txg
!= 0 &&
920 zh
->zh_claim_txg
== 0)) {
921 if (!BP_IS_HOLE(&zh
->zh_log
)) {
922 (void) zil_parse(zilog
, zil_clear_log_block
,
923 zil_noop_log_record
, tx
, first_txg
, B_FALSE
);
925 BP_ZERO(&zh
->zh_log
);
926 if (os
->os_encrypted
)
927 os
->os_next_write_raw
[tx
->tx_txg
& TXG_MASK
] = B_TRUE
;
928 dsl_dataset_dirty(dmu_objset_ds(os
), tx
);
929 dmu_objset_disown(os
, B_FALSE
, FTAG
);
934 * If we are not rewinding and opening the pool normally, then
935 * the min_claim_txg should be equal to the first txg of the pool.
937 ASSERT3U(first_txg
, ==, spa_first_txg(zilog
->zl_spa
));
940 * Claim all log blocks if we haven't already done so, and remember
941 * the highest claimed sequence number. This ensures that if we can
942 * read only part of the log now (e.g. due to a missing device),
943 * but we can read the entire log later, we will not try to replay
944 * or destroy beyond the last block we successfully claimed.
946 ASSERT3U(zh
->zh_claim_txg
, <=, first_txg
);
947 if (zh
->zh_claim_txg
== 0 && !BP_IS_HOLE(&zh
->zh_log
)) {
948 (void) zil_parse(zilog
, zil_claim_log_block
,
949 zil_claim_log_record
, tx
, first_txg
, B_FALSE
);
950 zh
->zh_claim_txg
= first_txg
;
951 zh
->zh_claim_blk_seq
= zilog
->zl_parse_blk_seq
;
952 zh
->zh_claim_lr_seq
= zilog
->zl_parse_lr_seq
;
953 if (zilog
->zl_parse_lr_count
|| zilog
->zl_parse_blk_count
> 1)
954 zh
->zh_flags
|= ZIL_REPLAY_NEEDED
;
955 zh
->zh_flags
|= ZIL_CLAIM_LR_SEQ_VALID
;
956 if (os
->os_encrypted
)
957 os
->os_next_write_raw
[tx
->tx_txg
& TXG_MASK
] = B_TRUE
;
958 dsl_dataset_dirty(dmu_objset_ds(os
), tx
);
961 ASSERT3U(first_txg
, ==, (spa_last_synced_txg(zilog
->zl_spa
) + 1));
962 dmu_objset_disown(os
, B_FALSE
, FTAG
);
967 * Check the log by walking the log chain.
968 * Checksum errors are ok as they indicate the end of the chain.
969 * Any other error (no device or read failure) returns an error.
972 zil_check_log_chain(dsl_pool_t
*dp
, dsl_dataset_t
*ds
, void *tx
)
982 error
= dmu_objset_from_ds(ds
, &os
);
984 cmn_err(CE_WARN
, "can't open objset %llu, error %d",
985 (unsigned long long)ds
->ds_object
, error
);
989 zilog
= dmu_objset_zil(os
);
990 bp
= (blkptr_t
*)&zilog
->zl_header
->zh_log
;
992 if (!BP_IS_HOLE(bp
)) {
994 boolean_t valid
= B_TRUE
;
997 * Check the first block and determine if it's on a log device
998 * which may have been removed or faulted prior to loading this
999 * pool. If so, there's no point in checking the rest of the
1000 * log as its content should have already been synced to the
1003 spa_config_enter(os
->os_spa
, SCL_STATE
, FTAG
, RW_READER
);
1004 vd
= vdev_lookup_top(os
->os_spa
, DVA_GET_VDEV(&bp
->blk_dva
[0]));
1005 if (vd
->vdev_islog
&& vdev_is_dead(vd
))
1006 valid
= vdev_log_state_valid(vd
);
1007 spa_config_exit(os
->os_spa
, SCL_STATE
, FTAG
);
1013 * Check whether the current uberblock is checkpointed (e.g.
1014 * we are rewinding) and whether the current header has been
1015 * claimed or not. If it hasn't then skip verifying it. We
1016 * do this because its ZIL blocks may be part of the pool's
1017 * state before the rewind, which is no longer valid.
1019 zil_header_t
*zh
= zil_header_in_syncing_context(zilog
);
1020 if (zilog
->zl_spa
->spa_uberblock
.ub_checkpoint_txg
!= 0 &&
1021 zh
->zh_claim_txg
== 0)
1026 * Because tx == NULL, zil_claim_log_block() will not actually claim
1027 * any blocks, but just determine whether it is possible to do so.
1028 * In addition to checking the log chain, zil_claim_log_block()
1029 * will invoke zio_claim() with a done func of spa_claim_notify(),
1030 * which will update spa_max_claim_txg. See spa_load() for details.
1032 error
= zil_parse(zilog
, zil_claim_log_block
, zil_claim_log_record
, tx
,
1033 zilog
->zl_header
->zh_claim_txg
? -1ULL :
1034 spa_min_claim_txg(os
->os_spa
), B_FALSE
);
1036 return ((error
== ECKSUM
|| error
== ENOENT
) ? 0 : error
);
1040 * When an itx is "skipped", this function is used to properly mark the
1041 * waiter as "done, and signal any thread(s) waiting on it. An itx can
1042 * be skipped (and not committed to an lwb) for a variety of reasons,
1043 * one of them being that the itx was committed via spa_sync(), prior to
1044 * it being committed to an lwb; this can happen if a thread calling
1045 * zil_commit() is racing with spa_sync().
1048 zil_commit_waiter_skip(zil_commit_waiter_t
*zcw
)
1050 mutex_enter(&zcw
->zcw_lock
);
1051 ASSERT3B(zcw
->zcw_done
, ==, B_FALSE
);
1052 zcw
->zcw_done
= B_TRUE
;
1053 cv_broadcast(&zcw
->zcw_cv
);
1054 mutex_exit(&zcw
->zcw_lock
);
1058 * This function is used when the given waiter is to be linked into an
1059 * lwb's "lwb_waiter" list; i.e. when the itx is committed to the lwb.
1060 * At this point, the waiter will no longer be referenced by the itx,
1061 * and instead, will be referenced by the lwb.
1064 zil_commit_waiter_link_lwb(zil_commit_waiter_t
*zcw
, lwb_t
*lwb
)
1067 * The lwb_waiters field of the lwb is protected by the zilog's
1068 * zl_lock, thus it must be held when calling this function.
1070 ASSERT(MUTEX_HELD(&lwb
->lwb_zilog
->zl_lock
));
1072 mutex_enter(&zcw
->zcw_lock
);
1073 ASSERT(!list_link_active(&zcw
->zcw_node
));
1074 ASSERT3P(zcw
->zcw_lwb
, ==, NULL
);
1075 ASSERT3P(lwb
, !=, NULL
);
1076 ASSERT(lwb
->lwb_state
== LWB_STATE_OPENED
||
1077 lwb
->lwb_state
== LWB_STATE_ISSUED
||
1078 lwb
->lwb_state
== LWB_STATE_WRITE_DONE
);
1080 list_insert_tail(&lwb
->lwb_waiters
, zcw
);
1082 mutex_exit(&zcw
->zcw_lock
);
1086 * This function is used when zio_alloc_zil() fails to allocate a ZIL
1087 * block, and the given waiter must be linked to the "nolwb waiters"
1088 * list inside of zil_process_commit_list().
1091 zil_commit_waiter_link_nolwb(zil_commit_waiter_t
*zcw
, list_t
*nolwb
)
1093 mutex_enter(&zcw
->zcw_lock
);
1094 ASSERT(!list_link_active(&zcw
->zcw_node
));
1095 ASSERT3P(zcw
->zcw_lwb
, ==, NULL
);
1096 list_insert_tail(nolwb
, zcw
);
1097 mutex_exit(&zcw
->zcw_lock
);
1101 zil_lwb_add_block(lwb_t
*lwb
, const blkptr_t
*bp
)
1103 avl_tree_t
*t
= &lwb
->lwb_vdev_tree
;
1105 zil_vdev_node_t
*zv
, zvsearch
;
1106 int ndvas
= BP_GET_NDVAS(bp
);
1109 if (zil_nocacheflush
)
1112 mutex_enter(&lwb
->lwb_vdev_lock
);
1113 for (i
= 0; i
< ndvas
; i
++) {
1114 zvsearch
.zv_vdev
= DVA_GET_VDEV(&bp
->blk_dva
[i
]);
1115 if (avl_find(t
, &zvsearch
, &where
) == NULL
) {
1116 zv
= kmem_alloc(sizeof (*zv
), KM_SLEEP
);
1117 zv
->zv_vdev
= zvsearch
.zv_vdev
;
1118 avl_insert(t
, zv
, where
);
1121 mutex_exit(&lwb
->lwb_vdev_lock
);
1125 zil_lwb_flush_defer(lwb_t
*lwb
, lwb_t
*nlwb
)
1127 avl_tree_t
*src
= &lwb
->lwb_vdev_tree
;
1128 avl_tree_t
*dst
= &nlwb
->lwb_vdev_tree
;
1129 void *cookie
= NULL
;
1130 zil_vdev_node_t
*zv
;
1132 ASSERT3S(lwb
->lwb_state
, ==, LWB_STATE_WRITE_DONE
);
1133 ASSERT3S(nlwb
->lwb_state
, !=, LWB_STATE_WRITE_DONE
);
1134 ASSERT3S(nlwb
->lwb_state
, !=, LWB_STATE_FLUSH_DONE
);
1137 * While 'lwb' is at a point in its lifetime where lwb_vdev_tree does
1138 * not need the protection of lwb_vdev_lock (it will only be modified
1139 * while holding zilog->zl_lock) as its writes and those of its
1140 * children have all completed. The younger 'nlwb' may be waiting on
1141 * future writes to additional vdevs.
1143 mutex_enter(&nlwb
->lwb_vdev_lock
);
1145 * Tear down the 'lwb' vdev tree, ensuring that entries which do not
1146 * exist in 'nlwb' are moved to it, freeing any would-be duplicates.
1148 while ((zv
= avl_destroy_nodes(src
, &cookie
)) != NULL
) {
1151 if (avl_find(dst
, zv
, &where
) == NULL
) {
1152 avl_insert(dst
, zv
, where
);
1154 kmem_free(zv
, sizeof (*zv
));
1157 mutex_exit(&nlwb
->lwb_vdev_lock
);
1161 zil_lwb_add_txg(lwb_t
*lwb
, uint64_t txg
)
1163 lwb
->lwb_max_txg
= MAX(lwb
->lwb_max_txg
, txg
);
1167 * This function is a called after all vdevs associated with a given lwb
1168 * write have completed their DKIOCFLUSHWRITECACHE command; or as soon
1169 * as the lwb write completes, if "zil_nocacheflush" is set. Further,
1170 * all "previous" lwb's will have completed before this function is
1171 * called; i.e. this function is called for all previous lwbs before
1172 * it's called for "this" lwb (enforced via zio the dependencies
1173 * configured in zil_lwb_set_zio_dependency()).
1175 * The intention is for this function to be called as soon as the
1176 * contents of an lwb are considered "stable" on disk, and will survive
1177 * any sudden loss of power. At this point, any threads waiting for the
1178 * lwb to reach this state are signalled, and the "waiter" structures
1179 * are marked "done".
1182 zil_lwb_flush_vdevs_done(zio_t
*zio
)
1184 lwb_t
*lwb
= zio
->io_private
;
1185 zilog_t
*zilog
= lwb
->lwb_zilog
;
1186 dmu_tx_t
*tx
= lwb
->lwb_tx
;
1187 zil_commit_waiter_t
*zcw
;
1190 spa_config_exit(zilog
->zl_spa
, SCL_STATE
, lwb
);
1192 zio_buf_free(lwb
->lwb_buf
, lwb
->lwb_sz
);
1194 mutex_enter(&zilog
->zl_lock
);
1197 * Ensure the lwb buffer pointer is cleared before releasing the
1198 * txg. If we have had an allocation failure and the txg is
1199 * waiting to sync then we want zil_sync() to remove the lwb so
1200 * that it's not picked up as the next new one in
1201 * zil_process_commit_list(). zil_sync() will only remove the
1202 * lwb if lwb_buf is null.
1204 lwb
->lwb_buf
= NULL
;
1207 ASSERT3U(lwb
->lwb_issued_timestamp
, >, 0);
1208 zilog
->zl_last_lwb_latency
= gethrtime() - lwb
->lwb_issued_timestamp
;
1210 lwb
->lwb_root_zio
= NULL
;
1212 ASSERT3S(lwb
->lwb_state
, ==, LWB_STATE_WRITE_DONE
);
1213 lwb
->lwb_state
= LWB_STATE_FLUSH_DONE
;
1215 if (zilog
->zl_last_lwb_opened
== lwb
) {
1217 * Remember the highest committed log sequence number
1218 * for ztest. We only update this value when all the log
1219 * writes succeeded, because ztest wants to ASSERT that
1220 * it got the whole log chain.
1222 zilog
->zl_commit_lr_seq
= zilog
->zl_lr_seq
;
1225 while ((itx
= list_head(&lwb
->lwb_itxs
)) != NULL
) {
1226 list_remove(&lwb
->lwb_itxs
, itx
);
1227 zil_itx_destroy(itx
);
1230 while ((zcw
= list_head(&lwb
->lwb_waiters
)) != NULL
) {
1231 mutex_enter(&zcw
->zcw_lock
);
1233 ASSERT(list_link_active(&zcw
->zcw_node
));
1234 list_remove(&lwb
->lwb_waiters
, zcw
);
1236 ASSERT3P(zcw
->zcw_lwb
, ==, lwb
);
1237 zcw
->zcw_lwb
= NULL
;
1239 * We expect any ZIO errors from child ZIOs to have been
1240 * propagated "up" to this specific LWB's root ZIO, in
1241 * order for this error handling to work correctly. This
1242 * includes ZIO errors from either this LWB's write or
1243 * flush, as well as any errors from other dependent LWBs
1244 * (e.g. a root LWB ZIO that might be a child of this LWB).
1246 * With that said, it's important to note that LWB flush
1247 * errors are not propagated up to the LWB root ZIO.
1248 * This is incorrect behavior, and results in VDEV flush
1249 * errors not being handled correctly here. See the
1250 * comment above the call to "zio_flush" for details.
1253 zcw
->zcw_zio_error
= zio
->io_error
;
1255 ASSERT3B(zcw
->zcw_done
, ==, B_FALSE
);
1256 zcw
->zcw_done
= B_TRUE
;
1257 cv_broadcast(&zcw
->zcw_cv
);
1259 mutex_exit(&zcw
->zcw_lock
);
1262 mutex_exit(&zilog
->zl_lock
);
1265 * Now that we've written this log block, we have a stable pointer
1266 * to the next block in the chain, so it's OK to let the txg in
1267 * which we allocated the next block sync.
1273 * This is called when an lwb's write zio completes. The callback's
1274 * purpose is to issue the DKIOCFLUSHWRITECACHE commands for the vdevs
1275 * in the lwb's lwb_vdev_tree. The tree will contain the vdevs involved
1276 * in writing out this specific lwb's data, and in the case that cache
1277 * flushes have been deferred, vdevs involved in writing the data for
1278 * previous lwbs. The writes corresponding to all the vdevs in the
1279 * lwb_vdev_tree will have completed by the time this is called, due to
1280 * the zio dependencies configured in zil_lwb_set_zio_dependency(),
1281 * which takes deferred flushes into account. The lwb will be "done"
1282 * once zil_lwb_flush_vdevs_done() is called, which occurs in the zio
1283 * completion callback for the lwb's root zio.
1286 zil_lwb_write_done(zio_t
*zio
)
1288 lwb_t
*lwb
= zio
->io_private
;
1289 spa_t
*spa
= zio
->io_spa
;
1290 zilog_t
*zilog
= lwb
->lwb_zilog
;
1291 avl_tree_t
*t
= &lwb
->lwb_vdev_tree
;
1292 void *cookie
= NULL
;
1293 zil_vdev_node_t
*zv
;
1296 ASSERT3S(spa_config_held(spa
, SCL_STATE
, RW_READER
), !=, 0);
1298 ASSERT(BP_GET_COMPRESS(zio
->io_bp
) == ZIO_COMPRESS_OFF
);
1299 ASSERT(BP_GET_TYPE(zio
->io_bp
) == DMU_OT_INTENT_LOG
);
1300 ASSERT(BP_GET_LEVEL(zio
->io_bp
) == 0);
1301 ASSERT(BP_GET_BYTEORDER(zio
->io_bp
) == ZFS_HOST_BYTEORDER
);
1302 ASSERT(!BP_IS_GANG(zio
->io_bp
));
1303 ASSERT(!BP_IS_HOLE(zio
->io_bp
));
1304 ASSERT(BP_GET_FILL(zio
->io_bp
) == 0);
1306 abd_free(zio
->io_abd
);
1308 mutex_enter(&zilog
->zl_lock
);
1309 ASSERT3S(lwb
->lwb_state
, ==, LWB_STATE_ISSUED
);
1310 lwb
->lwb_state
= LWB_STATE_WRITE_DONE
;
1311 lwb
->lwb_write_zio
= NULL
;
1312 lwb
->lwb_fastwrite
= FALSE
;
1313 nlwb
= list_next(&zilog
->zl_lwb_list
, lwb
);
1314 mutex_exit(&zilog
->zl_lock
);
1316 if (avl_numnodes(t
) == 0)
1320 * If there was an IO error, we're not going to call zio_flush()
1321 * on these vdevs, so we simply empty the tree and free the
1322 * nodes. We avoid calling zio_flush() since there isn't any
1323 * good reason for doing so, after the lwb block failed to be
1326 * Additionally, we don't perform any further error handling at
1327 * this point (e.g. setting "zcw_zio_error" appropriately), as
1328 * we expect that to occur in "zil_lwb_flush_vdevs_done" (thus,
1329 * we expect any error seen here, to have been propagated to
1332 if (zio
->io_error
!= 0) {
1333 while ((zv
= avl_destroy_nodes(t
, &cookie
)) != NULL
)
1334 kmem_free(zv
, sizeof (*zv
));
1339 * If this lwb does not have any threads waiting for it to
1340 * complete, we want to defer issuing the DKIOCFLUSHWRITECACHE
1341 * command to the vdevs written to by "this" lwb, and instead
1342 * rely on the "next" lwb to handle the DKIOCFLUSHWRITECACHE
1343 * command for those vdevs. Thus, we merge the vdev tree of
1344 * "this" lwb with the vdev tree of the "next" lwb in the list,
1345 * and assume the "next" lwb will handle flushing the vdevs (or
1346 * deferring the flush(s) again).
1348 * This is a useful performance optimization, especially for
1349 * workloads with lots of async write activity and few sync
1350 * write and/or fsync activity, as it has the potential to
1351 * coalesce multiple flush commands to a vdev into one.
1353 if (list_head(&lwb
->lwb_waiters
) == NULL
&& nlwb
!= NULL
) {
1354 zil_lwb_flush_defer(lwb
, nlwb
);
1355 ASSERT(avl_is_empty(&lwb
->lwb_vdev_tree
));
1359 while ((zv
= avl_destroy_nodes(t
, &cookie
)) != NULL
) {
1360 vdev_t
*vd
= vdev_lookup_top(spa
, zv
->zv_vdev
);
1363 * The "ZIO_FLAG_DONT_PROPAGATE" is currently
1364 * always used within "zio_flush". This means,
1365 * any errors when flushing the vdev(s), will
1366 * (unfortunately) not be handled correctly,
1367 * since these "zio_flush" errors will not be
1368 * propagated up to "zil_lwb_flush_vdevs_done".
1370 zio_flush(lwb
->lwb_root_zio
, vd
);
1372 kmem_free(zv
, sizeof (*zv
));
1377 zil_lwb_set_zio_dependency(zilog_t
*zilog
, lwb_t
*lwb
)
1379 lwb_t
*last_lwb_opened
= zilog
->zl_last_lwb_opened
;
1381 ASSERT(MUTEX_HELD(&zilog
->zl_issuer_lock
));
1382 ASSERT(MUTEX_HELD(&zilog
->zl_lock
));
1385 * The zilog's "zl_last_lwb_opened" field is used to build the
1386 * lwb/zio dependency chain, which is used to preserve the
1387 * ordering of lwb completions that is required by the semantics
1388 * of the ZIL. Each new lwb zio becomes a parent of the
1389 * "previous" lwb zio, such that the new lwb's zio cannot
1390 * complete until the "previous" lwb's zio completes.
1392 * This is required by the semantics of zil_commit(); the commit
1393 * waiters attached to the lwbs will be woken in the lwb zio's
1394 * completion callback, so this zio dependency graph ensures the
1395 * waiters are woken in the correct order (the same order the
1396 * lwbs were created).
1398 if (last_lwb_opened
!= NULL
&&
1399 last_lwb_opened
->lwb_state
!= LWB_STATE_FLUSH_DONE
) {
1400 ASSERT(last_lwb_opened
->lwb_state
== LWB_STATE_OPENED
||
1401 last_lwb_opened
->lwb_state
== LWB_STATE_ISSUED
||
1402 last_lwb_opened
->lwb_state
== LWB_STATE_WRITE_DONE
);
1404 ASSERT3P(last_lwb_opened
->lwb_root_zio
, !=, NULL
);
1405 zio_add_child(lwb
->lwb_root_zio
,
1406 last_lwb_opened
->lwb_root_zio
);
1409 * If the previous lwb's write hasn't already completed,
1410 * we also want to order the completion of the lwb write
1411 * zios (above, we only order the completion of the lwb
1412 * root zios). This is required because of how we can
1413 * defer the DKIOCFLUSHWRITECACHE commands for each lwb.
1415 * When the DKIOCFLUSHWRITECACHE commands are deferred,
1416 * the previous lwb will rely on this lwb to flush the
1417 * vdevs written to by that previous lwb. Thus, we need
1418 * to ensure this lwb doesn't issue the flush until
1419 * after the previous lwb's write completes. We ensure
1420 * this ordering by setting the zio parent/child
1421 * relationship here.
1423 * Without this relationship on the lwb's write zio,
1424 * it's possible for this lwb's write to complete prior
1425 * to the previous lwb's write completing; and thus, the
1426 * vdevs for the previous lwb would be flushed prior to
1427 * that lwb's data being written to those vdevs (the
1428 * vdevs are flushed in the lwb write zio's completion
1429 * handler, zil_lwb_write_done()).
1431 if (last_lwb_opened
->lwb_state
!= LWB_STATE_WRITE_DONE
) {
1432 ASSERT(last_lwb_opened
->lwb_state
== LWB_STATE_OPENED
||
1433 last_lwb_opened
->lwb_state
== LWB_STATE_ISSUED
);
1435 ASSERT3P(last_lwb_opened
->lwb_write_zio
, !=, NULL
);
1436 zio_add_child(lwb
->lwb_write_zio
,
1437 last_lwb_opened
->lwb_write_zio
);
1444 * This function's purpose is to "open" an lwb such that it is ready to
1445 * accept new itxs being committed to it. To do this, the lwb's zio
1446 * structures are created, and linked to the lwb. This function is
1447 * idempotent; if the passed in lwb has already been opened, this
1448 * function is essentially a no-op.
1451 zil_lwb_write_open(zilog_t
*zilog
, lwb_t
*lwb
)
1453 zbookmark_phys_t zb
;
1454 zio_priority_t prio
;
1456 ASSERT(MUTEX_HELD(&zilog
->zl_issuer_lock
));
1457 ASSERT3P(lwb
, !=, NULL
);
1458 EQUIV(lwb
->lwb_root_zio
== NULL
, lwb
->lwb_state
== LWB_STATE_CLOSED
);
1459 EQUIV(lwb
->lwb_root_zio
!= NULL
, lwb
->lwb_state
== LWB_STATE_OPENED
);
1461 SET_BOOKMARK(&zb
, lwb
->lwb_blk
.blk_cksum
.zc_word
[ZIL_ZC_OBJSET
],
1462 ZB_ZIL_OBJECT
, ZB_ZIL_LEVEL
,
1463 lwb
->lwb_blk
.blk_cksum
.zc_word
[ZIL_ZC_SEQ
]);
1465 /* Lock so zil_sync() doesn't fastwrite_unmark after zio is created */
1466 mutex_enter(&zilog
->zl_lock
);
1467 if (lwb
->lwb_root_zio
== NULL
) {
1468 abd_t
*lwb_abd
= abd_get_from_buf(lwb
->lwb_buf
,
1469 BP_GET_LSIZE(&lwb
->lwb_blk
));
1471 if (!lwb
->lwb_fastwrite
) {
1472 metaslab_fastwrite_mark(zilog
->zl_spa
, &lwb
->lwb_blk
);
1473 lwb
->lwb_fastwrite
= 1;
1476 if (!lwb
->lwb_slog
|| zilog
->zl_cur_used
<= zil_slog_bulk
)
1477 prio
= ZIO_PRIORITY_SYNC_WRITE
;
1479 prio
= ZIO_PRIORITY_ASYNC_WRITE
;
1481 lwb
->lwb_root_zio
= zio_root(zilog
->zl_spa
,
1482 zil_lwb_flush_vdevs_done
, lwb
, ZIO_FLAG_CANFAIL
);
1483 ASSERT3P(lwb
->lwb_root_zio
, !=, NULL
);
1485 lwb
->lwb_write_zio
= zio_rewrite(lwb
->lwb_root_zio
,
1486 zilog
->zl_spa
, 0, &lwb
->lwb_blk
, lwb_abd
,
1487 BP_GET_LSIZE(&lwb
->lwb_blk
), zil_lwb_write_done
, lwb
,
1488 prio
, ZIO_FLAG_CANFAIL
| ZIO_FLAG_FASTWRITE
, &zb
);
1489 ASSERT3P(lwb
->lwb_write_zio
, !=, NULL
);
1491 lwb
->lwb_state
= LWB_STATE_OPENED
;
1493 zil_lwb_set_zio_dependency(zilog
, lwb
);
1494 zilog
->zl_last_lwb_opened
= lwb
;
1496 mutex_exit(&zilog
->zl_lock
);
1498 ASSERT3P(lwb
->lwb_root_zio
, !=, NULL
);
1499 ASSERT3P(lwb
->lwb_write_zio
, !=, NULL
);
1500 ASSERT3S(lwb
->lwb_state
, ==, LWB_STATE_OPENED
);
1504 * Define a limited set of intent log block sizes.
1506 * These must be a multiple of 4KB. Note only the amount used (again
1507 * aligned to 4KB) actually gets written. However, we can't always just
1508 * allocate SPA_OLD_MAXBLOCKSIZE as the slog space could be exhausted.
1510 static const struct {
1513 } zil_block_buckets
[] = {
1514 { 4096, 4096 }, /* non TX_WRITE */
1515 { 8192 + 4096, 8192 + 4096 }, /* database */
1516 { 32768 + 4096, 32768 + 4096 }, /* NFS writes */
1517 { 65536 + 4096, 65536 + 4096 }, /* 64KB writes */
1518 { 131072, 131072 }, /* < 128KB writes */
1519 { 131072 +4096, 65536 + 4096 }, /* 128KB writes */
1520 { UINT64_MAX
, SPA_OLD_MAXBLOCKSIZE
}, /* > 128KB writes */
1524 * Maximum block size used by the ZIL. This is picked up when the ZIL is
1525 * initialized. Otherwise this should not be used directly; see
1526 * zl_max_block_size instead.
1528 static int zil_maxblocksize
= SPA_OLD_MAXBLOCKSIZE
;
1531 * Start a log block write and advance to the next log block.
1532 * Calls are serialized.
1535 zil_lwb_write_issue(zilog_t
*zilog
, lwb_t
*lwb
)
1539 spa_t
*spa
= zilog
->zl_spa
;
1543 uint64_t zil_blksz
, wsz
;
1547 ASSERT(MUTEX_HELD(&zilog
->zl_issuer_lock
));
1548 ASSERT3P(lwb
->lwb_root_zio
, !=, NULL
);
1549 ASSERT3P(lwb
->lwb_write_zio
, !=, NULL
);
1550 ASSERT3S(lwb
->lwb_state
, ==, LWB_STATE_OPENED
);
1552 if (BP_GET_CHECKSUM(&lwb
->lwb_blk
) == ZIO_CHECKSUM_ZILOG2
) {
1553 zilc
= (zil_chain_t
*)lwb
->lwb_buf
;
1554 bp
= &zilc
->zc_next_blk
;
1556 zilc
= (zil_chain_t
*)(lwb
->lwb_buf
+ lwb
->lwb_sz
);
1557 bp
= &zilc
->zc_next_blk
;
1560 ASSERT(lwb
->lwb_nused
<= lwb
->lwb_sz
);
1563 * Allocate the next block and save its address in this block
1564 * before writing it in order to establish the log chain.
1565 * Note that if the allocation of nlwb synced before we wrote
1566 * the block that points at it (lwb), we'd leak it if we crashed.
1567 * Therefore, we don't do dmu_tx_commit() until zil_lwb_write_done().
1568 * We dirty the dataset to ensure that zil_sync() will be called
1569 * to clean up in the event of allocation failure or I/O failure.
1572 tx
= dmu_tx_create(zilog
->zl_os
);
1575 * Since we are not going to create any new dirty data, and we
1576 * can even help with clearing the existing dirty data, we
1577 * should not be subject to the dirty data based delays. We
1578 * use TXG_NOTHROTTLE to bypass the delay mechanism.
1580 VERIFY0(dmu_tx_assign(tx
, TXG_WAIT
| TXG_NOTHROTTLE
));
1582 dsl_dataset_dirty(dmu_objset_ds(zilog
->zl_os
), tx
);
1583 txg
= dmu_tx_get_txg(tx
);
1588 * Log blocks are pre-allocated. Here we select the size of the next
1589 * block, based on size used in the last block.
1590 * - first find the smallest bucket that will fit the block from a
1591 * limited set of block sizes. This is because it's faster to write
1592 * blocks allocated from the same metaslab as they are adjacent or
1594 * - next find the maximum from the new suggested size and an array of
1595 * previous sizes. This lessens a picket fence effect of wrongly
1596 * guessing the size if we have a stream of say 2k, 64k, 2k, 64k
1599 * Note we only write what is used, but we can't just allocate
1600 * the maximum block size because we can exhaust the available
1603 zil_blksz
= zilog
->zl_cur_used
+ sizeof (zil_chain_t
);
1604 for (i
= 0; zil_blksz
> zil_block_buckets
[i
].limit
; i
++)
1606 zil_blksz
= MIN(zil_block_buckets
[i
].blksz
, zilog
->zl_max_block_size
);
1607 zilog
->zl_prev_blks
[zilog
->zl_prev_rotor
] = zil_blksz
;
1608 for (i
= 0; i
< ZIL_PREV_BLKS
; i
++)
1609 zil_blksz
= MAX(zil_blksz
, zilog
->zl_prev_blks
[i
]);
1610 zilog
->zl_prev_rotor
= (zilog
->zl_prev_rotor
+ 1) & (ZIL_PREV_BLKS
- 1);
1613 error
= zio_alloc_zil(spa
, zilog
->zl_os
, txg
, bp
, zil_blksz
, &slog
);
1615 ZIL_STAT_BUMP(zil_itx_metaslab_slog_count
);
1616 ZIL_STAT_INCR(zil_itx_metaslab_slog_bytes
, lwb
->lwb_nused
);
1618 ZIL_STAT_BUMP(zil_itx_metaslab_normal_count
);
1619 ZIL_STAT_INCR(zil_itx_metaslab_normal_bytes
, lwb
->lwb_nused
);
1622 ASSERT3U(bp
->blk_birth
, ==, txg
);
1623 bp
->blk_cksum
= lwb
->lwb_blk
.blk_cksum
;
1624 bp
->blk_cksum
.zc_word
[ZIL_ZC_SEQ
]++;
1627 * Allocate a new log write block (lwb).
1629 nlwb
= zil_alloc_lwb(zilog
, bp
, slog
, txg
, TRUE
);
1632 if (BP_GET_CHECKSUM(&lwb
->lwb_blk
) == ZIO_CHECKSUM_ZILOG2
) {
1633 /* For Slim ZIL only write what is used. */
1634 wsz
= P2ROUNDUP_TYPED(lwb
->lwb_nused
, ZIL_MIN_BLKSZ
, uint64_t);
1635 ASSERT3U(wsz
, <=, lwb
->lwb_sz
);
1636 zio_shrink(lwb
->lwb_write_zio
, wsz
);
1643 zilc
->zc_nused
= lwb
->lwb_nused
;
1644 zilc
->zc_eck
.zec_cksum
= lwb
->lwb_blk
.blk_cksum
;
1647 * clear unused data for security
1649 memset(lwb
->lwb_buf
+ lwb
->lwb_nused
, 0, wsz
- lwb
->lwb_nused
);
1651 spa_config_enter(zilog
->zl_spa
, SCL_STATE
, lwb
, RW_READER
);
1653 zil_lwb_add_block(lwb
, &lwb
->lwb_blk
);
1654 lwb
->lwb_issued_timestamp
= gethrtime();
1655 lwb
->lwb_state
= LWB_STATE_ISSUED
;
1657 zio_nowait(lwb
->lwb_root_zio
);
1658 zio_nowait(lwb
->lwb_write_zio
);
1661 * If there was an allocation failure then nlwb will be null which
1662 * forces a txg_wait_synced().
1668 * Maximum amount of write data that can be put into single log block.
1671 zil_max_log_data(zilog_t
*zilog
)
1673 return (zilog
->zl_max_block_size
-
1674 sizeof (zil_chain_t
) - sizeof (lr_write_t
));
1678 * Maximum amount of log space we agree to waste to reduce number of
1679 * WR_NEED_COPY chunks to reduce zl_get_data() overhead (~12%).
1681 static inline uint64_t
1682 zil_max_waste_space(zilog_t
*zilog
)
1684 return (zil_max_log_data(zilog
) / 8);
1688 * Maximum amount of write data for WR_COPIED. For correctness, consumers
1689 * must fall back to WR_NEED_COPY if we can't fit the entire record into one
1690 * maximum sized log block, because each WR_COPIED record must fit in a
1691 * single log block. For space efficiency, we want to fit two records into a
1692 * max-sized log block.
1695 zil_max_copied_data(zilog_t
*zilog
)
1697 return ((zilog
->zl_max_block_size
- sizeof (zil_chain_t
)) / 2 -
1698 sizeof (lr_write_t
));
1702 zil_lwb_commit(zilog_t
*zilog
, itx_t
*itx
, lwb_t
*lwb
)
1705 lr_write_t
*lrwb
, *lrw
;
1707 uint64_t dlen
, dnow
, dpad
, lwb_sp
, reclen
, txg
, max_log_data
;
1709 ASSERT(MUTEX_HELD(&zilog
->zl_issuer_lock
));
1710 ASSERT3P(lwb
, !=, NULL
);
1711 ASSERT3P(lwb
->lwb_buf
, !=, NULL
);
1713 zil_lwb_write_open(zilog
, lwb
);
1716 lrw
= (lr_write_t
*)lrc
;
1719 * A commit itx doesn't represent any on-disk state; instead
1720 * it's simply used as a place holder on the commit list, and
1721 * provides a mechanism for attaching a "commit waiter" onto the
1722 * correct lwb (such that the waiter can be signalled upon
1723 * completion of that lwb). Thus, we don't process this itx's
1724 * log record if it's a commit itx (these itx's don't have log
1725 * records), and instead link the itx's waiter onto the lwb's
1728 * For more details, see the comment above zil_commit().
1730 if (lrc
->lrc_txtype
== TX_COMMIT
) {
1731 mutex_enter(&zilog
->zl_lock
);
1732 zil_commit_waiter_link_lwb(itx
->itx_private
, lwb
);
1733 itx
->itx_private
= NULL
;
1734 mutex_exit(&zilog
->zl_lock
);
1738 if (lrc
->lrc_txtype
== TX_WRITE
&& itx
->itx_wr_state
== WR_NEED_COPY
) {
1739 dlen
= P2ROUNDUP_TYPED(
1740 lrw
->lr_length
, sizeof (uint64_t), uint64_t);
1741 dpad
= dlen
- lrw
->lr_length
;
1745 reclen
= lrc
->lrc_reclen
;
1746 zilog
->zl_cur_used
+= (reclen
+ dlen
);
1749 ASSERT3U(zilog
->zl_cur_used
, <, UINT64_MAX
- (reclen
+ dlen
));
1753 * If this record won't fit in the current log block, start a new one.
1754 * For WR_NEED_COPY optimize layout for minimal number of chunks.
1756 lwb_sp
= lwb
->lwb_sz
- lwb
->lwb_nused
;
1757 max_log_data
= zil_max_log_data(zilog
);
1758 if (reclen
> lwb_sp
|| (reclen
+ dlen
> lwb_sp
&&
1759 lwb_sp
< zil_max_waste_space(zilog
) &&
1760 (dlen
% max_log_data
== 0 ||
1761 lwb_sp
< reclen
+ dlen
% max_log_data
))) {
1762 lwb
= zil_lwb_write_issue(zilog
, lwb
);
1765 zil_lwb_write_open(zilog
, lwb
);
1766 ASSERT(LWB_EMPTY(lwb
));
1767 lwb_sp
= lwb
->lwb_sz
- lwb
->lwb_nused
;
1770 * There must be enough space in the new, empty log block to
1771 * hold reclen. For WR_COPIED, we need to fit the whole
1772 * record in one block, and reclen is the header size + the
1773 * data size. For WR_NEED_COPY, we can create multiple
1774 * records, splitting the data into multiple blocks, so we
1775 * only need to fit one word of data per block; in this case
1776 * reclen is just the header size (no data).
1778 ASSERT3U(reclen
+ MIN(dlen
, sizeof (uint64_t)), <=, lwb_sp
);
1781 dnow
= MIN(dlen
, lwb_sp
- reclen
);
1782 lr_buf
= lwb
->lwb_buf
+ lwb
->lwb_nused
;
1783 memcpy(lr_buf
, lrc
, reclen
);
1784 lrcb
= (lr_t
*)lr_buf
; /* Like lrc, but inside lwb. */
1785 lrwb
= (lr_write_t
*)lrcb
; /* Like lrw, but inside lwb. */
1787 ZIL_STAT_BUMP(zil_itx_count
);
1790 * If it's a write, fetch the data or get its blkptr as appropriate.
1792 if (lrc
->lrc_txtype
== TX_WRITE
) {
1793 if (txg
> spa_freeze_txg(zilog
->zl_spa
))
1794 txg_wait_synced(zilog
->zl_dmu_pool
, txg
);
1795 if (itx
->itx_wr_state
== WR_COPIED
) {
1796 ZIL_STAT_BUMP(zil_itx_copied_count
);
1797 ZIL_STAT_INCR(zil_itx_copied_bytes
, lrw
->lr_length
);
1802 if (itx
->itx_wr_state
== WR_NEED_COPY
) {
1803 dbuf
= lr_buf
+ reclen
;
1804 lrcb
->lrc_reclen
+= dnow
;
1805 if (lrwb
->lr_length
> dnow
)
1806 lrwb
->lr_length
= dnow
;
1807 lrw
->lr_offset
+= dnow
;
1808 lrw
->lr_length
-= dnow
;
1809 ZIL_STAT_BUMP(zil_itx_needcopy_count
);
1810 ZIL_STAT_INCR(zil_itx_needcopy_bytes
, dnow
);
1812 ASSERT3S(itx
->itx_wr_state
, ==, WR_INDIRECT
);
1814 ZIL_STAT_BUMP(zil_itx_indirect_count
);
1815 ZIL_STAT_INCR(zil_itx_indirect_bytes
,
1820 * We pass in the "lwb_write_zio" rather than
1821 * "lwb_root_zio" so that the "lwb_write_zio"
1822 * becomes the parent of any zio's created by
1823 * the "zl_get_data" callback. The vdevs are
1824 * flushed after the "lwb_write_zio" completes,
1825 * so we want to make sure that completion
1826 * callback waits for these additional zio's,
1827 * such that the vdevs used by those zio's will
1828 * be included in the lwb's vdev tree, and those
1829 * vdevs will be properly flushed. If we passed
1830 * in "lwb_root_zio" here, then these additional
1831 * vdevs may not be flushed; e.g. if these zio's
1832 * completed after "lwb_write_zio" completed.
1834 error
= zilog
->zl_get_data(itx
->itx_private
,
1835 itx
->itx_gen
, lrwb
, dbuf
, lwb
,
1836 lwb
->lwb_write_zio
);
1837 if (dbuf
!= NULL
&& error
== 0 && dnow
== dlen
)
1838 /* Zero any padding bytes in the last block. */
1839 memset((char *)dbuf
+ lrwb
->lr_length
, 0, dpad
);
1842 txg_wait_synced(zilog
->zl_dmu_pool
, txg
);
1846 ASSERT(error
== ENOENT
|| error
== EEXIST
||
1854 * We're actually making an entry, so update lrc_seq to be the
1855 * log record sequence number. Note that this is generally not
1856 * equal to the itx sequence number because not all transactions
1857 * are synchronous, and sometimes spa_sync() gets there first.
1859 lrcb
->lrc_seq
= ++zilog
->zl_lr_seq
;
1860 lwb
->lwb_nused
+= reclen
+ dnow
;
1862 zil_lwb_add_txg(lwb
, txg
);
1864 ASSERT3U(lwb
->lwb_nused
, <=, lwb
->lwb_sz
);
1865 ASSERT0(P2PHASE(lwb
->lwb_nused
, sizeof (uint64_t)));
1869 zilog
->zl_cur_used
+= reclen
;
1877 zil_itx_create(uint64_t txtype
, size_t olrsize
)
1879 size_t itxsize
, lrsize
;
1882 lrsize
= P2ROUNDUP_TYPED(olrsize
, sizeof (uint64_t), size_t);
1883 itxsize
= offsetof(itx_t
, itx_lr
) + lrsize
;
1885 itx
= zio_data_buf_alloc(itxsize
);
1886 itx
->itx_lr
.lrc_txtype
= txtype
;
1887 itx
->itx_lr
.lrc_reclen
= lrsize
;
1888 itx
->itx_lr
.lrc_seq
= 0; /* defensive */
1889 memset((char *)&itx
->itx_lr
+ olrsize
, 0, lrsize
- olrsize
);
1890 itx
->itx_sync
= B_TRUE
; /* default is synchronous */
1891 itx
->itx_callback
= NULL
;
1892 itx
->itx_callback_data
= NULL
;
1893 itx
->itx_size
= itxsize
;
1899 zil_itx_destroy(itx_t
*itx
)
1901 IMPLY(itx
->itx_lr
.lrc_txtype
== TX_COMMIT
, itx
->itx_callback
== NULL
);
1902 IMPLY(itx
->itx_callback
!= NULL
, itx
->itx_lr
.lrc_txtype
!= TX_COMMIT
);
1904 if (itx
->itx_callback
!= NULL
)
1905 itx
->itx_callback(itx
->itx_callback_data
);
1907 zio_data_buf_free(itx
, itx
->itx_size
);
1911 * Free up the sync and async itxs. The itxs_t has already been detached
1912 * so no locks are needed.
1915 zil_itxg_clean(void *arg
)
1922 itx_async_node_t
*ian
;
1924 list
= &itxs
->i_sync_list
;
1925 while ((itx
= list_head(list
)) != NULL
) {
1927 * In the general case, commit itxs will not be found
1928 * here, as they'll be committed to an lwb via
1929 * zil_lwb_commit(), and free'd in that function. Having
1930 * said that, it is still possible for commit itxs to be
1931 * found here, due to the following race:
1933 * - a thread calls zil_commit() which assigns the
1934 * commit itx to a per-txg i_sync_list
1935 * - zil_itxg_clean() is called (e.g. via spa_sync())
1936 * while the waiter is still on the i_sync_list
1938 * There's nothing to prevent syncing the txg while the
1939 * waiter is on the i_sync_list. This normally doesn't
1940 * happen because spa_sync() is slower than zil_commit(),
1941 * but if zil_commit() calls txg_wait_synced() (e.g.
1942 * because zil_create() or zil_commit_writer_stall() is
1943 * called) we will hit this case.
1945 if (itx
->itx_lr
.lrc_txtype
== TX_COMMIT
)
1946 zil_commit_waiter_skip(itx
->itx_private
);
1948 list_remove(list
, itx
);
1949 zil_itx_destroy(itx
);
1953 t
= &itxs
->i_async_tree
;
1954 while ((ian
= avl_destroy_nodes(t
, &cookie
)) != NULL
) {
1955 list
= &ian
->ia_list
;
1956 while ((itx
= list_head(list
)) != NULL
) {
1957 list_remove(list
, itx
);
1958 /* commit itxs should never be on the async lists. */
1959 ASSERT3U(itx
->itx_lr
.lrc_txtype
, !=, TX_COMMIT
);
1960 zil_itx_destroy(itx
);
1963 kmem_free(ian
, sizeof (itx_async_node_t
));
1967 kmem_free(itxs
, sizeof (itxs_t
));
1971 zil_aitx_compare(const void *x1
, const void *x2
)
1973 const uint64_t o1
= ((itx_async_node_t
*)x1
)->ia_foid
;
1974 const uint64_t o2
= ((itx_async_node_t
*)x2
)->ia_foid
;
1976 return (TREE_CMP(o1
, o2
));
1980 * Remove all async itx with the given oid.
1983 zil_remove_async(zilog_t
*zilog
, uint64_t oid
)
1986 itx_async_node_t
*ian
;
1993 list_create(&clean_list
, sizeof (itx_t
), offsetof(itx_t
, itx_node
));
1995 if (spa_freeze_txg(zilog
->zl_spa
) != UINT64_MAX
) /* ziltest support */
1998 otxg
= spa_last_synced_txg(zilog
->zl_spa
) + 1;
2000 for (txg
= otxg
; txg
< (otxg
+ TXG_CONCURRENT_STATES
); txg
++) {
2001 itxg_t
*itxg
= &zilog
->zl_itxg
[txg
& TXG_MASK
];
2003 mutex_enter(&itxg
->itxg_lock
);
2004 if (itxg
->itxg_txg
!= txg
) {
2005 mutex_exit(&itxg
->itxg_lock
);
2010 * Locate the object node and append its list.
2012 t
= &itxg
->itxg_itxs
->i_async_tree
;
2013 ian
= avl_find(t
, &oid
, &where
);
2015 list_move_tail(&clean_list
, &ian
->ia_list
);
2016 mutex_exit(&itxg
->itxg_lock
);
2018 while ((itx
= list_head(&clean_list
)) != NULL
) {
2019 list_remove(&clean_list
, itx
);
2020 /* commit itxs should never be on the async lists. */
2021 ASSERT3U(itx
->itx_lr
.lrc_txtype
, !=, TX_COMMIT
);
2022 zil_itx_destroy(itx
);
2024 list_destroy(&clean_list
);
2028 zil_itx_assign(zilog_t
*zilog
, itx_t
*itx
, dmu_tx_t
*tx
)
2032 itxs_t
*itxs
, *clean
= NULL
;
2035 * Ensure the data of a renamed file is committed before the rename.
2037 if ((itx
->itx_lr
.lrc_txtype
& ~TX_CI
) == TX_RENAME
)
2038 zil_async_to_sync(zilog
, itx
->itx_oid
);
2040 if (spa_freeze_txg(zilog
->zl_spa
) != UINT64_MAX
)
2043 txg
= dmu_tx_get_txg(tx
);
2045 itxg
= &zilog
->zl_itxg
[txg
& TXG_MASK
];
2046 mutex_enter(&itxg
->itxg_lock
);
2047 itxs
= itxg
->itxg_itxs
;
2048 if (itxg
->itxg_txg
!= txg
) {
2051 * The zil_clean callback hasn't got around to cleaning
2052 * this itxg. Save the itxs for release below.
2053 * This should be rare.
2055 zfs_dbgmsg("zil_itx_assign: missed itx cleanup for "
2056 "txg %llu", (u_longlong_t
)itxg
->itxg_txg
);
2057 clean
= itxg
->itxg_itxs
;
2059 itxg
->itxg_txg
= txg
;
2060 itxs
= itxg
->itxg_itxs
= kmem_zalloc(sizeof (itxs_t
),
2063 list_create(&itxs
->i_sync_list
, sizeof (itx_t
),
2064 offsetof(itx_t
, itx_node
));
2065 avl_create(&itxs
->i_async_tree
, zil_aitx_compare
,
2066 sizeof (itx_async_node_t
),
2067 offsetof(itx_async_node_t
, ia_node
));
2069 if (itx
->itx_sync
) {
2070 list_insert_tail(&itxs
->i_sync_list
, itx
);
2072 avl_tree_t
*t
= &itxs
->i_async_tree
;
2074 LR_FOID_GET_OBJ(((lr_ooo_t
*)&itx
->itx_lr
)->lr_foid
);
2075 itx_async_node_t
*ian
;
2078 ian
= avl_find(t
, &foid
, &where
);
2080 ian
= kmem_alloc(sizeof (itx_async_node_t
),
2082 list_create(&ian
->ia_list
, sizeof (itx_t
),
2083 offsetof(itx_t
, itx_node
));
2084 ian
->ia_foid
= foid
;
2085 avl_insert(t
, ian
, where
);
2087 list_insert_tail(&ian
->ia_list
, itx
);
2090 itx
->itx_lr
.lrc_txg
= dmu_tx_get_txg(tx
);
2093 * We don't want to dirty the ZIL using ZILTEST_TXG, because
2094 * zil_clean() will never be called using ZILTEST_TXG. Thus, we
2095 * need to be careful to always dirty the ZIL using the "real"
2096 * TXG (not itxg_txg) even when the SPA is frozen.
2098 zilog_dirty(zilog
, dmu_tx_get_txg(tx
));
2099 mutex_exit(&itxg
->itxg_lock
);
2101 /* Release the old itxs now we've dropped the lock */
2103 zil_itxg_clean(clean
);
2107 * If there are any in-memory intent log transactions which have now been
2108 * synced then start up a taskq to free them. We should only do this after we
2109 * have written out the uberblocks (i.e. txg has been committed) so that
2110 * don't inadvertently clean out in-memory log records that would be required
2114 zil_clean(zilog_t
*zilog
, uint64_t synced_txg
)
2116 itxg_t
*itxg
= &zilog
->zl_itxg
[synced_txg
& TXG_MASK
];
2119 ASSERT3U(synced_txg
, <, ZILTEST_TXG
);
2121 mutex_enter(&itxg
->itxg_lock
);
2122 if (itxg
->itxg_itxs
== NULL
|| itxg
->itxg_txg
== ZILTEST_TXG
) {
2123 mutex_exit(&itxg
->itxg_lock
);
2126 ASSERT3U(itxg
->itxg_txg
, <=, synced_txg
);
2127 ASSERT3U(itxg
->itxg_txg
, !=, 0);
2128 clean_me
= itxg
->itxg_itxs
;
2129 itxg
->itxg_itxs
= NULL
;
2131 mutex_exit(&itxg
->itxg_lock
);
2133 * Preferably start a task queue to free up the old itxs but
2134 * if taskq_dispatch can't allocate resources to do that then
2135 * free it in-line. This should be rare. Note, using TQ_SLEEP
2136 * created a bad performance problem.
2138 ASSERT3P(zilog
->zl_dmu_pool
, !=, NULL
);
2139 ASSERT3P(zilog
->zl_dmu_pool
->dp_zil_clean_taskq
, !=, NULL
);
2140 taskqid_t id
= taskq_dispatch(zilog
->zl_dmu_pool
->dp_zil_clean_taskq
,
2141 zil_itxg_clean
, clean_me
, TQ_NOSLEEP
);
2142 if (id
== TASKQID_INVALID
)
2143 zil_itxg_clean(clean_me
);
2147 * This function will traverse the queue of itxs that need to be
2148 * committed, and move them onto the ZIL's zl_itx_commit_list.
2151 zil_get_commit_list(zilog_t
*zilog
)
2154 list_t
*commit_list
= &zilog
->zl_itx_commit_list
;
2156 ASSERT(MUTEX_HELD(&zilog
->zl_issuer_lock
));
2158 if (spa_freeze_txg(zilog
->zl_spa
) != UINT64_MAX
) /* ziltest support */
2161 otxg
= spa_last_synced_txg(zilog
->zl_spa
) + 1;
2164 * This is inherently racy, since there is nothing to prevent
2165 * the last synced txg from changing. That's okay since we'll
2166 * only commit things in the future.
2168 for (txg
= otxg
; txg
< (otxg
+ TXG_CONCURRENT_STATES
); txg
++) {
2169 itxg_t
*itxg
= &zilog
->zl_itxg
[txg
& TXG_MASK
];
2171 mutex_enter(&itxg
->itxg_lock
);
2172 if (itxg
->itxg_txg
!= txg
) {
2173 mutex_exit(&itxg
->itxg_lock
);
2178 * If we're adding itx records to the zl_itx_commit_list,
2179 * then the zil better be dirty in this "txg". We can assert
2180 * that here since we're holding the itxg_lock which will
2181 * prevent spa_sync from cleaning it. Once we add the itxs
2182 * to the zl_itx_commit_list we must commit it to disk even
2183 * if it's unnecessary (i.e. the txg was synced).
2185 ASSERT(zilog_is_dirty_in_txg(zilog
, txg
) ||
2186 spa_freeze_txg(zilog
->zl_spa
) != UINT64_MAX
);
2187 list_move_tail(commit_list
, &itxg
->itxg_itxs
->i_sync_list
);
2189 mutex_exit(&itxg
->itxg_lock
);
2194 * Move the async itxs for a specified object to commit into sync lists.
2197 zil_async_to_sync(zilog_t
*zilog
, uint64_t foid
)
2200 itx_async_node_t
*ian
;
2204 if (spa_freeze_txg(zilog
->zl_spa
) != UINT64_MAX
) /* ziltest support */
2207 otxg
= spa_last_synced_txg(zilog
->zl_spa
) + 1;
2210 * This is inherently racy, since there is nothing to prevent
2211 * the last synced txg from changing.
2213 for (txg
= otxg
; txg
< (otxg
+ TXG_CONCURRENT_STATES
); txg
++) {
2214 itxg_t
*itxg
= &zilog
->zl_itxg
[txg
& TXG_MASK
];
2216 mutex_enter(&itxg
->itxg_lock
);
2217 if (itxg
->itxg_txg
!= txg
) {
2218 mutex_exit(&itxg
->itxg_lock
);
2223 * If a foid is specified then find that node and append its
2224 * list. Otherwise walk the tree appending all the lists
2225 * to the sync list. We add to the end rather than the
2226 * beginning to ensure the create has happened.
2228 t
= &itxg
->itxg_itxs
->i_async_tree
;
2230 ian
= avl_find(t
, &foid
, &where
);
2232 list_move_tail(&itxg
->itxg_itxs
->i_sync_list
,
2236 void *cookie
= NULL
;
2238 while ((ian
= avl_destroy_nodes(t
, &cookie
)) != NULL
) {
2239 list_move_tail(&itxg
->itxg_itxs
->i_sync_list
,
2241 list_destroy(&ian
->ia_list
);
2242 kmem_free(ian
, sizeof (itx_async_node_t
));
2245 mutex_exit(&itxg
->itxg_lock
);
2250 * This function will prune commit itxs that are at the head of the
2251 * commit list (it won't prune past the first non-commit itx), and
2252 * either: a) attach them to the last lwb that's still pending
2253 * completion, or b) skip them altogether.
2255 * This is used as a performance optimization to prevent commit itxs
2256 * from generating new lwbs when it's unnecessary to do so.
2259 zil_prune_commit_list(zilog_t
*zilog
)
2263 ASSERT(MUTEX_HELD(&zilog
->zl_issuer_lock
));
2265 while ((itx
= list_head(&zilog
->zl_itx_commit_list
)) != NULL
) {
2266 lr_t
*lrc
= &itx
->itx_lr
;
2267 if (lrc
->lrc_txtype
!= TX_COMMIT
)
2270 mutex_enter(&zilog
->zl_lock
);
2272 lwb_t
*last_lwb
= zilog
->zl_last_lwb_opened
;
2273 if (last_lwb
== NULL
||
2274 last_lwb
->lwb_state
== LWB_STATE_FLUSH_DONE
) {
2276 * All of the itxs this waiter was waiting on
2277 * must have already completed (or there were
2278 * never any itx's for it to wait on), so it's
2279 * safe to skip this waiter and mark it done.
2281 zil_commit_waiter_skip(itx
->itx_private
);
2283 zil_commit_waiter_link_lwb(itx
->itx_private
, last_lwb
);
2284 itx
->itx_private
= NULL
;
2287 mutex_exit(&zilog
->zl_lock
);
2289 list_remove(&zilog
->zl_itx_commit_list
, itx
);
2290 zil_itx_destroy(itx
);
2293 IMPLY(itx
!= NULL
, itx
->itx_lr
.lrc_txtype
!= TX_COMMIT
);
2297 zil_commit_writer_stall(zilog_t
*zilog
)
2300 * When zio_alloc_zil() fails to allocate the next lwb block on
2301 * disk, we must call txg_wait_synced() to ensure all of the
2302 * lwbs in the zilog's zl_lwb_list are synced and then freed (in
2303 * zil_sync()), such that any subsequent ZIL writer (i.e. a call
2304 * to zil_process_commit_list()) will have to call zil_create(),
2305 * and start a new ZIL chain.
2307 * Since zil_alloc_zil() failed, the lwb that was previously
2308 * issued does not have a pointer to the "next" lwb on disk.
2309 * Thus, if another ZIL writer thread was to allocate the "next"
2310 * on-disk lwb, that block could be leaked in the event of a
2311 * crash (because the previous lwb on-disk would not point to
2314 * We must hold the zilog's zl_issuer_lock while we do this, to
2315 * ensure no new threads enter zil_process_commit_list() until
2316 * all lwb's in the zl_lwb_list have been synced and freed
2317 * (which is achieved via the txg_wait_synced() call).
2319 ASSERT(MUTEX_HELD(&zilog
->zl_issuer_lock
));
2320 txg_wait_synced(zilog
->zl_dmu_pool
, 0);
2321 ASSERT3P(list_tail(&zilog
->zl_lwb_list
), ==, NULL
);
2325 * This function will traverse the commit list, creating new lwbs as
2326 * needed, and committing the itxs from the commit list to these newly
2327 * created lwbs. Additionally, as a new lwb is created, the previous
2328 * lwb will be issued to the zio layer to be written to disk.
2331 zil_process_commit_list(zilog_t
*zilog
)
2333 spa_t
*spa
= zilog
->zl_spa
;
2335 list_t nolwb_waiters
;
2339 ASSERT(MUTEX_HELD(&zilog
->zl_issuer_lock
));
2342 * Return if there's nothing to commit before we dirty the fs by
2343 * calling zil_create().
2345 if (list_head(&zilog
->zl_itx_commit_list
) == NULL
)
2348 list_create(&nolwb_itxs
, sizeof (itx_t
), offsetof(itx_t
, itx_node
));
2349 list_create(&nolwb_waiters
, sizeof (zil_commit_waiter_t
),
2350 offsetof(zil_commit_waiter_t
, zcw_node
));
2352 lwb
= list_tail(&zilog
->zl_lwb_list
);
2354 lwb
= zil_create(zilog
);
2357 * Activate SPA_FEATURE_ZILSAXATTR for the cases where ZIL will
2358 * have already been created (zl_lwb_list not empty).
2360 zil_commit_activate_saxattr_feature(zilog
);
2361 ASSERT3S(lwb
->lwb_state
, !=, LWB_STATE_ISSUED
);
2362 ASSERT3S(lwb
->lwb_state
, !=, LWB_STATE_WRITE_DONE
);
2363 ASSERT3S(lwb
->lwb_state
, !=, LWB_STATE_FLUSH_DONE
);
2366 while ((itx
= list_head(&zilog
->zl_itx_commit_list
)) != NULL
) {
2367 lr_t
*lrc
= &itx
->itx_lr
;
2368 uint64_t txg
= lrc
->lrc_txg
;
2370 ASSERT3U(txg
, !=, 0);
2372 if (lrc
->lrc_txtype
== TX_COMMIT
) {
2373 DTRACE_PROBE2(zil__process__commit__itx
,
2374 zilog_t
*, zilog
, itx_t
*, itx
);
2376 DTRACE_PROBE2(zil__process__normal__itx
,
2377 zilog_t
*, zilog
, itx_t
*, itx
);
2380 list_remove(&zilog
->zl_itx_commit_list
, itx
);
2382 boolean_t synced
= txg
<= spa_last_synced_txg(spa
);
2383 boolean_t frozen
= txg
> spa_freeze_txg(spa
);
2386 * If the txg of this itx has already been synced out, then
2387 * we don't need to commit this itx to an lwb. This is
2388 * because the data of this itx will have already been
2389 * written to the main pool. This is inherently racy, and
2390 * it's still ok to commit an itx whose txg has already
2391 * been synced; this will result in a write that's
2392 * unnecessary, but will do no harm.
2394 * With that said, we always want to commit TX_COMMIT itxs
2395 * to an lwb, regardless of whether or not that itx's txg
2396 * has been synced out. We do this to ensure any OPENED lwb
2397 * will always have at least one zil_commit_waiter_t linked
2400 * As a counter-example, if we skipped TX_COMMIT itx's
2401 * whose txg had already been synced, the following
2402 * situation could occur if we happened to be racing with
2405 * 1. We commit a non-TX_COMMIT itx to an lwb, where the
2406 * itx's txg is 10 and the last synced txg is 9.
2407 * 2. spa_sync finishes syncing out txg 10.
2408 * 3. We move to the next itx in the list, it's a TX_COMMIT
2409 * whose txg is 10, so we skip it rather than committing
2410 * it to the lwb used in (1).
2412 * If the itx that is skipped in (3) is the last TX_COMMIT
2413 * itx in the commit list, than it's possible for the lwb
2414 * used in (1) to remain in the OPENED state indefinitely.
2416 * To prevent the above scenario from occurring, ensuring
2417 * that once an lwb is OPENED it will transition to ISSUED
2418 * and eventually DONE, we always commit TX_COMMIT itx's to
2419 * an lwb here, even if that itx's txg has already been
2422 * Finally, if the pool is frozen, we _always_ commit the
2423 * itx. The point of freezing the pool is to prevent data
2424 * from being written to the main pool via spa_sync, and
2425 * instead rely solely on the ZIL to persistently store the
2426 * data; i.e. when the pool is frozen, the last synced txg
2427 * value can't be trusted.
2429 if (frozen
|| !synced
|| lrc
->lrc_txtype
== TX_COMMIT
) {
2431 lwb
= zil_lwb_commit(zilog
, itx
, lwb
);
2434 list_insert_tail(&nolwb_itxs
, itx
);
2436 list_insert_tail(&lwb
->lwb_itxs
, itx
);
2438 if (lrc
->lrc_txtype
== TX_COMMIT
) {
2439 zil_commit_waiter_link_nolwb(
2440 itx
->itx_private
, &nolwb_waiters
);
2443 list_insert_tail(&nolwb_itxs
, itx
);
2446 ASSERT3S(lrc
->lrc_txtype
, !=, TX_COMMIT
);
2447 zil_itx_destroy(itx
);
2453 * This indicates zio_alloc_zil() failed to allocate the
2454 * "next" lwb on-disk. When this happens, we must stall
2455 * the ZIL write pipeline; see the comment within
2456 * zil_commit_writer_stall() for more details.
2458 zil_commit_writer_stall(zilog
);
2461 * Additionally, we have to signal and mark the "nolwb"
2462 * waiters as "done" here, since without an lwb, we
2463 * can't do this via zil_lwb_flush_vdevs_done() like
2466 zil_commit_waiter_t
*zcw
;
2467 while ((zcw
= list_head(&nolwb_waiters
)) != NULL
) {
2468 zil_commit_waiter_skip(zcw
);
2469 list_remove(&nolwb_waiters
, zcw
);
2473 * And finally, we have to destroy the itx's that
2474 * couldn't be committed to an lwb; this will also call
2475 * the itx's callback if one exists for the itx.
2477 while ((itx
= list_head(&nolwb_itxs
)) != NULL
) {
2478 list_remove(&nolwb_itxs
, itx
);
2479 zil_itx_destroy(itx
);
2482 ASSERT(list_is_empty(&nolwb_waiters
));
2483 ASSERT3P(lwb
, !=, NULL
);
2484 ASSERT3S(lwb
->lwb_state
, !=, LWB_STATE_ISSUED
);
2485 ASSERT3S(lwb
->lwb_state
, !=, LWB_STATE_WRITE_DONE
);
2486 ASSERT3S(lwb
->lwb_state
, !=, LWB_STATE_FLUSH_DONE
);
2489 * At this point, the ZIL block pointed at by the "lwb"
2490 * variable is in one of the following states: "closed"
2493 * If it's "closed", then no itxs have been committed to
2494 * it, so there's no point in issuing its zio (i.e. it's
2497 * If it's "open", then it contains one or more itxs that
2498 * eventually need to be committed to stable storage. In
2499 * this case we intentionally do not issue the lwb's zio
2500 * to disk yet, and instead rely on one of the following
2501 * two mechanisms for issuing the zio:
2503 * 1. Ideally, there will be more ZIL activity occurring
2504 * on the system, such that this function will be
2505 * immediately called again (not necessarily by the same
2506 * thread) and this lwb's zio will be issued via
2507 * zil_lwb_commit(). This way, the lwb is guaranteed to
2508 * be "full" when it is issued to disk, and we'll make
2509 * use of the lwb's size the best we can.
2511 * 2. If there isn't sufficient ZIL activity occurring on
2512 * the system, such that this lwb's zio isn't issued via
2513 * zil_lwb_commit(), zil_commit_waiter() will issue the
2514 * lwb's zio. If this occurs, the lwb is not guaranteed
2515 * to be "full" by the time its zio is issued, and means
2516 * the size of the lwb was "too large" given the amount
2517 * of ZIL activity occurring on the system at that time.
2519 * We do this for a couple of reasons:
2521 * 1. To try and reduce the number of IOPs needed to
2522 * write the same number of itxs. If an lwb has space
2523 * available in its buffer for more itxs, and more itxs
2524 * will be committed relatively soon (relative to the
2525 * latency of performing a write), then it's beneficial
2526 * to wait for these "next" itxs. This way, more itxs
2527 * can be committed to stable storage with fewer writes.
2529 * 2. To try and use the largest lwb block size that the
2530 * incoming rate of itxs can support. Again, this is to
2531 * try and pack as many itxs into as few lwbs as
2532 * possible, without significantly impacting the latency
2533 * of each individual itx.
2539 * This function is responsible for ensuring the passed in commit waiter
2540 * (and associated commit itx) is committed to an lwb. If the waiter is
2541 * not already committed to an lwb, all itxs in the zilog's queue of
2542 * itxs will be processed. The assumption is the passed in waiter's
2543 * commit itx will found in the queue just like the other non-commit
2544 * itxs, such that when the entire queue is processed, the waiter will
2545 * have been committed to an lwb.
2547 * The lwb associated with the passed in waiter is not guaranteed to
2548 * have been issued by the time this function completes. If the lwb is
2549 * not issued, we rely on future calls to zil_commit_writer() to issue
2550 * the lwb, or the timeout mechanism found in zil_commit_waiter().
2553 zil_commit_writer(zilog_t
*zilog
, zil_commit_waiter_t
*zcw
)
2555 ASSERT(!MUTEX_HELD(&zilog
->zl_lock
));
2556 ASSERT(spa_writeable(zilog
->zl_spa
));
2558 mutex_enter(&zilog
->zl_issuer_lock
);
2560 if (zcw
->zcw_lwb
!= NULL
|| zcw
->zcw_done
) {
2562 * It's possible that, while we were waiting to acquire
2563 * the "zl_issuer_lock", another thread committed this
2564 * waiter to an lwb. If that occurs, we bail out early,
2565 * without processing any of the zilog's queue of itxs.
2567 * On certain workloads and system configurations, the
2568 * "zl_issuer_lock" can become highly contended. In an
2569 * attempt to reduce this contention, we immediately drop
2570 * the lock if the waiter has already been processed.
2572 * We've measured this optimization to reduce CPU spent
2573 * contending on this lock by up to 5%, using a system
2574 * with 32 CPUs, low latency storage (~50 usec writes),
2575 * and 1024 threads performing sync writes.
2580 ZIL_STAT_BUMP(zil_commit_writer_count
);
2582 zil_get_commit_list(zilog
);
2583 zil_prune_commit_list(zilog
);
2584 zil_process_commit_list(zilog
);
2587 mutex_exit(&zilog
->zl_issuer_lock
);
2591 zil_commit_waiter_timeout(zilog_t
*zilog
, zil_commit_waiter_t
*zcw
)
2593 ASSERT(!MUTEX_HELD(&zilog
->zl_issuer_lock
));
2594 ASSERT(MUTEX_HELD(&zcw
->zcw_lock
));
2595 ASSERT3B(zcw
->zcw_done
, ==, B_FALSE
);
2597 lwb_t
*lwb
= zcw
->zcw_lwb
;
2598 ASSERT3P(lwb
, !=, NULL
);
2599 ASSERT3S(lwb
->lwb_state
, !=, LWB_STATE_CLOSED
);
2602 * If the lwb has already been issued by another thread, we can
2603 * immediately return since there's no work to be done (the
2604 * point of this function is to issue the lwb). Additionally, we
2605 * do this prior to acquiring the zl_issuer_lock, to avoid
2606 * acquiring it when it's not necessary to do so.
2608 if (lwb
->lwb_state
== LWB_STATE_ISSUED
||
2609 lwb
->lwb_state
== LWB_STATE_WRITE_DONE
||
2610 lwb
->lwb_state
== LWB_STATE_FLUSH_DONE
)
2614 * In order to call zil_lwb_write_issue() we must hold the
2615 * zilog's "zl_issuer_lock". We can't simply acquire that lock,
2616 * since we're already holding the commit waiter's "zcw_lock",
2617 * and those two locks are acquired in the opposite order
2620 mutex_exit(&zcw
->zcw_lock
);
2621 mutex_enter(&zilog
->zl_issuer_lock
);
2622 mutex_enter(&zcw
->zcw_lock
);
2625 * Since we just dropped and re-acquired the commit waiter's
2626 * lock, we have to re-check to see if the waiter was marked
2627 * "done" during that process. If the waiter was marked "done",
2628 * the "lwb" pointer is no longer valid (it can be free'd after
2629 * the waiter is marked "done"), so without this check we could
2630 * wind up with a use-after-free error below.
2635 ASSERT3P(lwb
, ==, zcw
->zcw_lwb
);
2638 * We've already checked this above, but since we hadn't acquired
2639 * the zilog's zl_issuer_lock, we have to perform this check a
2640 * second time while holding the lock.
2642 * We don't need to hold the zl_lock since the lwb cannot transition
2643 * from OPENED to ISSUED while we hold the zl_issuer_lock. The lwb
2644 * _can_ transition from ISSUED to DONE, but it's OK to race with
2645 * that transition since we treat the lwb the same, whether it's in
2646 * the ISSUED or DONE states.
2648 * The important thing, is we treat the lwb differently depending on
2649 * if it's ISSUED or OPENED, and block any other threads that might
2650 * attempt to issue this lwb. For that reason we hold the
2651 * zl_issuer_lock when checking the lwb_state; we must not call
2652 * zil_lwb_write_issue() if the lwb had already been issued.
2654 * See the comment above the lwb_state_t structure definition for
2655 * more details on the lwb states, and locking requirements.
2657 if (lwb
->lwb_state
== LWB_STATE_ISSUED
||
2658 lwb
->lwb_state
== LWB_STATE_WRITE_DONE
||
2659 lwb
->lwb_state
== LWB_STATE_FLUSH_DONE
)
2662 ASSERT3S(lwb
->lwb_state
, ==, LWB_STATE_OPENED
);
2665 * As described in the comments above zil_commit_waiter() and
2666 * zil_process_commit_list(), we need to issue this lwb's zio
2667 * since we've reached the commit waiter's timeout and it still
2668 * hasn't been issued.
2670 lwb_t
*nlwb
= zil_lwb_write_issue(zilog
, lwb
);
2672 IMPLY(nlwb
!= NULL
, lwb
->lwb_state
!= LWB_STATE_OPENED
);
2675 * Since the lwb's zio hadn't been issued by the time this thread
2676 * reached its timeout, we reset the zilog's "zl_cur_used" field
2677 * to influence the zil block size selection algorithm.
2679 * By having to issue the lwb's zio here, it means the size of the
2680 * lwb was too large, given the incoming throughput of itxs. By
2681 * setting "zl_cur_used" to zero, we communicate this fact to the
2682 * block size selection algorithm, so it can take this information
2683 * into account, and potentially select a smaller size for the
2684 * next lwb block that is allocated.
2686 zilog
->zl_cur_used
= 0;
2690 * When zil_lwb_write_issue() returns NULL, this
2691 * indicates zio_alloc_zil() failed to allocate the
2692 * "next" lwb on-disk. When this occurs, the ZIL write
2693 * pipeline must be stalled; see the comment within the
2694 * zil_commit_writer_stall() function for more details.
2696 * We must drop the commit waiter's lock prior to
2697 * calling zil_commit_writer_stall() or else we can wind
2698 * up with the following deadlock:
2700 * - This thread is waiting for the txg to sync while
2701 * holding the waiter's lock; txg_wait_synced() is
2702 * used within txg_commit_writer_stall().
2704 * - The txg can't sync because it is waiting for this
2705 * lwb's zio callback to call dmu_tx_commit().
2707 * - The lwb's zio callback can't call dmu_tx_commit()
2708 * because it's blocked trying to acquire the waiter's
2709 * lock, which occurs prior to calling dmu_tx_commit()
2711 mutex_exit(&zcw
->zcw_lock
);
2712 zil_commit_writer_stall(zilog
);
2713 mutex_enter(&zcw
->zcw_lock
);
2717 mutex_exit(&zilog
->zl_issuer_lock
);
2718 ASSERT(MUTEX_HELD(&zcw
->zcw_lock
));
2722 * This function is responsible for performing the following two tasks:
2724 * 1. its primary responsibility is to block until the given "commit
2725 * waiter" is considered "done".
2727 * 2. its secondary responsibility is to issue the zio for the lwb that
2728 * the given "commit waiter" is waiting on, if this function has
2729 * waited "long enough" and the lwb is still in the "open" state.
2731 * Given a sufficient amount of itxs being generated and written using
2732 * the ZIL, the lwb's zio will be issued via the zil_lwb_commit()
2733 * function. If this does not occur, this secondary responsibility will
2734 * ensure the lwb is issued even if there is not other synchronous
2735 * activity on the system.
2737 * For more details, see zil_process_commit_list(); more specifically,
2738 * the comment at the bottom of that function.
2741 zil_commit_waiter(zilog_t
*zilog
, zil_commit_waiter_t
*zcw
)
2743 ASSERT(!MUTEX_HELD(&zilog
->zl_lock
));
2744 ASSERT(!MUTEX_HELD(&zilog
->zl_issuer_lock
));
2745 ASSERT(spa_writeable(zilog
->zl_spa
));
2747 mutex_enter(&zcw
->zcw_lock
);
2750 * The timeout is scaled based on the lwb latency to avoid
2751 * significantly impacting the latency of each individual itx.
2752 * For more details, see the comment at the bottom of the
2753 * zil_process_commit_list() function.
2755 int pct
= MAX(zfs_commit_timeout_pct
, 1);
2756 hrtime_t sleep
= (zilog
->zl_last_lwb_latency
* pct
) / 100;
2757 hrtime_t wakeup
= gethrtime() + sleep
;
2758 boolean_t timedout
= B_FALSE
;
2760 while (!zcw
->zcw_done
) {
2761 ASSERT(MUTEX_HELD(&zcw
->zcw_lock
));
2763 lwb_t
*lwb
= zcw
->zcw_lwb
;
2766 * Usually, the waiter will have a non-NULL lwb field here,
2767 * but it's possible for it to be NULL as a result of
2768 * zil_commit() racing with spa_sync().
2770 * When zil_clean() is called, it's possible for the itxg
2771 * list (which may be cleaned via a taskq) to contain
2772 * commit itxs. When this occurs, the commit waiters linked
2773 * off of these commit itxs will not be committed to an
2774 * lwb. Additionally, these commit waiters will not be
2775 * marked done until zil_commit_waiter_skip() is called via
2778 * Thus, it's possible for this commit waiter (i.e. the
2779 * "zcw" variable) to be found in this "in between" state;
2780 * where it's "zcw_lwb" field is NULL, and it hasn't yet
2781 * been skipped, so it's "zcw_done" field is still B_FALSE.
2783 IMPLY(lwb
!= NULL
, lwb
->lwb_state
!= LWB_STATE_CLOSED
);
2785 if (lwb
!= NULL
&& lwb
->lwb_state
== LWB_STATE_OPENED
) {
2786 ASSERT3B(timedout
, ==, B_FALSE
);
2789 * If the lwb hasn't been issued yet, then we
2790 * need to wait with a timeout, in case this
2791 * function needs to issue the lwb after the
2792 * timeout is reached; responsibility (2) from
2793 * the comment above this function.
2795 int rc
= cv_timedwait_hires(&zcw
->zcw_cv
,
2796 &zcw
->zcw_lock
, wakeup
, USEC2NSEC(1),
2797 CALLOUT_FLAG_ABSOLUTE
);
2799 if (rc
!= -1 || zcw
->zcw_done
)
2803 zil_commit_waiter_timeout(zilog
, zcw
);
2805 if (!zcw
->zcw_done
) {
2807 * If the commit waiter has already been
2808 * marked "done", it's possible for the
2809 * waiter's lwb structure to have already
2810 * been freed. Thus, we can only reliably
2811 * make these assertions if the waiter
2814 ASSERT3P(lwb
, ==, zcw
->zcw_lwb
);
2815 ASSERT3S(lwb
->lwb_state
, !=, LWB_STATE_OPENED
);
2819 * If the lwb isn't open, then it must have already
2820 * been issued. In that case, there's no need to
2821 * use a timeout when waiting for the lwb to
2824 * Additionally, if the lwb is NULL, the waiter
2825 * will soon be signaled and marked done via
2826 * zil_clean() and zil_itxg_clean(), so no timeout
2831 lwb
->lwb_state
== LWB_STATE_ISSUED
||
2832 lwb
->lwb_state
== LWB_STATE_WRITE_DONE
||
2833 lwb
->lwb_state
== LWB_STATE_FLUSH_DONE
);
2834 cv_wait(&zcw
->zcw_cv
, &zcw
->zcw_lock
);
2838 mutex_exit(&zcw
->zcw_lock
);
2841 static zil_commit_waiter_t
*
2842 zil_alloc_commit_waiter(void)
2844 zil_commit_waiter_t
*zcw
= kmem_cache_alloc(zil_zcw_cache
, KM_SLEEP
);
2846 cv_init(&zcw
->zcw_cv
, NULL
, CV_DEFAULT
, NULL
);
2847 mutex_init(&zcw
->zcw_lock
, NULL
, MUTEX_DEFAULT
, NULL
);
2848 list_link_init(&zcw
->zcw_node
);
2849 zcw
->zcw_lwb
= NULL
;
2850 zcw
->zcw_done
= B_FALSE
;
2851 zcw
->zcw_zio_error
= 0;
2857 zil_free_commit_waiter(zil_commit_waiter_t
*zcw
)
2859 ASSERT(!list_link_active(&zcw
->zcw_node
));
2860 ASSERT3P(zcw
->zcw_lwb
, ==, NULL
);
2861 ASSERT3B(zcw
->zcw_done
, ==, B_TRUE
);
2862 mutex_destroy(&zcw
->zcw_lock
);
2863 cv_destroy(&zcw
->zcw_cv
);
2864 kmem_cache_free(zil_zcw_cache
, zcw
);
2868 * This function is used to create a TX_COMMIT itx and assign it. This
2869 * way, it will be linked into the ZIL's list of synchronous itxs, and
2870 * then later committed to an lwb (or skipped) when
2871 * zil_process_commit_list() is called.
2874 zil_commit_itx_assign(zilog_t
*zilog
, zil_commit_waiter_t
*zcw
)
2876 dmu_tx_t
*tx
= dmu_tx_create(zilog
->zl_os
);
2877 VERIFY0(dmu_tx_assign(tx
, TXG_WAIT
));
2879 itx_t
*itx
= zil_itx_create(TX_COMMIT
, sizeof (lr_t
));
2880 itx
->itx_sync
= B_TRUE
;
2881 itx
->itx_private
= zcw
;
2883 zil_itx_assign(zilog
, itx
, tx
);
2889 * Commit ZFS Intent Log transactions (itxs) to stable storage.
2891 * When writing ZIL transactions to the on-disk representation of the
2892 * ZIL, the itxs are committed to a Log Write Block (lwb). Multiple
2893 * itxs can be committed to a single lwb. Once a lwb is written and
2894 * committed to stable storage (i.e. the lwb is written, and vdevs have
2895 * been flushed), each itx that was committed to that lwb is also
2896 * considered to be committed to stable storage.
2898 * When an itx is committed to an lwb, the log record (lr_t) contained
2899 * by the itx is copied into the lwb's zio buffer, and once this buffer
2900 * is written to disk, it becomes an on-disk ZIL block.
2902 * As itxs are generated, they're inserted into the ZIL's queue of
2903 * uncommitted itxs. The semantics of zil_commit() are such that it will
2904 * block until all itxs that were in the queue when it was called, are
2905 * committed to stable storage.
2907 * If "foid" is zero, this means all "synchronous" and "asynchronous"
2908 * itxs, for all objects in the dataset, will be committed to stable
2909 * storage prior to zil_commit() returning. If "foid" is non-zero, all
2910 * "synchronous" itxs for all objects, but only "asynchronous" itxs
2911 * that correspond to the foid passed in, will be committed to stable
2912 * storage prior to zil_commit() returning.
2914 * Generally speaking, when zil_commit() is called, the consumer doesn't
2915 * actually care about _all_ of the uncommitted itxs. Instead, they're
2916 * simply trying to waiting for a specific itx to be committed to disk,
2917 * but the interface(s) for interacting with the ZIL don't allow such
2918 * fine-grained communication. A better interface would allow a consumer
2919 * to create and assign an itx, and then pass a reference to this itx to
2920 * zil_commit(); such that zil_commit() would return as soon as that
2921 * specific itx was committed to disk (instead of waiting for _all_
2922 * itxs to be committed).
2924 * When a thread calls zil_commit() a special "commit itx" will be
2925 * generated, along with a corresponding "waiter" for this commit itx.
2926 * zil_commit() will wait on this waiter's CV, such that when the waiter
2927 * is marked done, and signaled, zil_commit() will return.
2929 * This commit itx is inserted into the queue of uncommitted itxs. This
2930 * provides an easy mechanism for determining which itxs were in the
2931 * queue prior to zil_commit() having been called, and which itxs were
2932 * added after zil_commit() was called.
2934 * The commit it is special; it doesn't have any on-disk representation.
2935 * When a commit itx is "committed" to an lwb, the waiter associated
2936 * with it is linked onto the lwb's list of waiters. Then, when that lwb
2937 * completes, each waiter on the lwb's list is marked done and signaled
2938 * -- allowing the thread waiting on the waiter to return from zil_commit().
2940 * It's important to point out a few critical factors that allow us
2941 * to make use of the commit itxs, commit waiters, per-lwb lists of
2942 * commit waiters, and zio completion callbacks like we're doing:
2944 * 1. The list of waiters for each lwb is traversed, and each commit
2945 * waiter is marked "done" and signaled, in the zio completion
2946 * callback of the lwb's zio[*].
2948 * * Actually, the waiters are signaled in the zio completion
2949 * callback of the root zio for the DKIOCFLUSHWRITECACHE commands
2950 * that are sent to the vdevs upon completion of the lwb zio.
2952 * 2. When the itxs are inserted into the ZIL's queue of uncommitted
2953 * itxs, the order in which they are inserted is preserved[*]; as
2954 * itxs are added to the queue, they are added to the tail of
2955 * in-memory linked lists.
2957 * When committing the itxs to lwbs (to be written to disk), they
2958 * are committed in the same order in which the itxs were added to
2959 * the uncommitted queue's linked list(s); i.e. the linked list of
2960 * itxs to commit is traversed from head to tail, and each itx is
2961 * committed to an lwb in that order.
2965 * - the order of "sync" itxs is preserved w.r.t. other
2966 * "sync" itxs, regardless of the corresponding objects.
2967 * - the order of "async" itxs is preserved w.r.t. other
2968 * "async" itxs corresponding to the same object.
2969 * - the order of "async" itxs is *not* preserved w.r.t. other
2970 * "async" itxs corresponding to different objects.
2971 * - the order of "sync" itxs w.r.t. "async" itxs (or vice
2972 * versa) is *not* preserved, even for itxs that correspond
2973 * to the same object.
2975 * For more details, see: zil_itx_assign(), zil_async_to_sync(),
2976 * zil_get_commit_list(), and zil_process_commit_list().
2978 * 3. The lwbs represent a linked list of blocks on disk. Thus, any
2979 * lwb cannot be considered committed to stable storage, until its
2980 * "previous" lwb is also committed to stable storage. This fact,
2981 * coupled with the fact described above, means that itxs are
2982 * committed in (roughly) the order in which they were generated.
2983 * This is essential because itxs are dependent on prior itxs.
2984 * Thus, we *must not* deem an itx as being committed to stable
2985 * storage, until *all* prior itxs have also been committed to
2988 * To enforce this ordering of lwb zio's, while still leveraging as
2989 * much of the underlying storage performance as possible, we rely
2990 * on two fundamental concepts:
2992 * 1. The creation and issuance of lwb zio's is protected by
2993 * the zilog's "zl_issuer_lock", which ensures only a single
2994 * thread is creating and/or issuing lwb's at a time
2995 * 2. The "previous" lwb is a child of the "current" lwb
2996 * (leveraging the zio parent-child dependency graph)
2998 * By relying on this parent-child zio relationship, we can have
2999 * many lwb zio's concurrently issued to the underlying storage,
3000 * but the order in which they complete will be the same order in
3001 * which they were created.
3004 zil_commit(zilog_t
*zilog
, uint64_t foid
)
3007 * We should never attempt to call zil_commit on a snapshot for
3008 * a couple of reasons:
3010 * 1. A snapshot may never be modified, thus it cannot have any
3011 * in-flight itxs that would have modified the dataset.
3013 * 2. By design, when zil_commit() is called, a commit itx will
3014 * be assigned to this zilog; as a result, the zilog will be
3015 * dirtied. We must not dirty the zilog of a snapshot; there's
3016 * checks in the code that enforce this invariant, and will
3017 * cause a panic if it's not upheld.
3019 ASSERT3B(dmu_objset_is_snapshot(zilog
->zl_os
), ==, B_FALSE
);
3021 if (zilog
->zl_sync
== ZFS_SYNC_DISABLED
)
3024 if (!spa_writeable(zilog
->zl_spa
)) {
3026 * If the SPA is not writable, there should never be any
3027 * pending itxs waiting to be committed to disk. If that
3028 * weren't true, we'd skip writing those itxs out, and
3029 * would break the semantics of zil_commit(); thus, we're
3030 * verifying that truth before we return to the caller.
3032 ASSERT(list_is_empty(&zilog
->zl_lwb_list
));
3033 ASSERT3P(zilog
->zl_last_lwb_opened
, ==, NULL
);
3034 for (int i
= 0; i
< TXG_SIZE
; i
++)
3035 ASSERT3P(zilog
->zl_itxg
[i
].itxg_itxs
, ==, NULL
);
3040 * If the ZIL is suspended, we don't want to dirty it by calling
3041 * zil_commit_itx_assign() below, nor can we write out
3042 * lwbs like would be done in zil_commit_write(). Thus, we
3043 * simply rely on txg_wait_synced() to maintain the necessary
3044 * semantics, and avoid calling those functions altogether.
3046 if (zilog
->zl_suspend
> 0) {
3047 txg_wait_synced(zilog
->zl_dmu_pool
, 0);
3051 zil_commit_impl(zilog
, foid
);
3055 zil_commit_impl(zilog_t
*zilog
, uint64_t foid
)
3057 ZIL_STAT_BUMP(zil_commit_count
);
3060 * Move the "async" itxs for the specified foid to the "sync"
3061 * queues, such that they will be later committed (or skipped)
3062 * to an lwb when zil_process_commit_list() is called.
3064 * Since these "async" itxs must be committed prior to this
3065 * call to zil_commit returning, we must perform this operation
3066 * before we call zil_commit_itx_assign().
3068 zil_async_to_sync(zilog
, foid
);
3071 * We allocate a new "waiter" structure which will initially be
3072 * linked to the commit itx using the itx's "itx_private" field.
3073 * Since the commit itx doesn't represent any on-disk state,
3074 * when it's committed to an lwb, rather than copying the its
3075 * lr_t into the lwb's buffer, the commit itx's "waiter" will be
3076 * added to the lwb's list of waiters. Then, when the lwb is
3077 * committed to stable storage, each waiter in the lwb's list of
3078 * waiters will be marked "done", and signalled.
3080 * We must create the waiter and assign the commit itx prior to
3081 * calling zil_commit_writer(), or else our specific commit itx
3082 * is not guaranteed to be committed to an lwb prior to calling
3083 * zil_commit_waiter().
3085 zil_commit_waiter_t
*zcw
= zil_alloc_commit_waiter();
3086 zil_commit_itx_assign(zilog
, zcw
);
3088 zil_commit_writer(zilog
, zcw
);
3089 zil_commit_waiter(zilog
, zcw
);
3091 if (zcw
->zcw_zio_error
!= 0) {
3093 * If there was an error writing out the ZIL blocks that
3094 * this thread is waiting on, then we fallback to
3095 * relying on spa_sync() to write out the data this
3096 * thread is waiting on. Obviously this has performance
3097 * implications, but the expectation is for this to be
3098 * an exceptional case, and shouldn't occur often.
3100 DTRACE_PROBE2(zil__commit__io__error
,
3101 zilog_t
*, zilog
, zil_commit_waiter_t
*, zcw
);
3102 txg_wait_synced(zilog
->zl_dmu_pool
, 0);
3105 zil_free_commit_waiter(zcw
);
3109 * Called in syncing context to free committed log blocks and update log header.
3112 zil_sync(zilog_t
*zilog
, dmu_tx_t
*tx
)
3114 zil_header_t
*zh
= zil_header_in_syncing_context(zilog
);
3115 uint64_t txg
= dmu_tx_get_txg(tx
);
3116 spa_t
*spa
= zilog
->zl_spa
;
3117 uint64_t *replayed_seq
= &zilog
->zl_replayed_seq
[txg
& TXG_MASK
];
3121 * We don't zero out zl_destroy_txg, so make sure we don't try
3122 * to destroy it twice.
3124 if (spa_sync_pass(spa
) != 1)
3127 mutex_enter(&zilog
->zl_lock
);
3129 ASSERT(zilog
->zl_stop_sync
== 0);
3131 if (*replayed_seq
!= 0) {
3132 ASSERT(zh
->zh_replay_seq
< *replayed_seq
);
3133 zh
->zh_replay_seq
= *replayed_seq
;
3137 if (zilog
->zl_destroy_txg
== txg
) {
3138 blkptr_t blk
= zh
->zh_log
;
3139 dsl_dataset_t
*ds
= dmu_objset_ds(zilog
->zl_os
);
3141 ASSERT(list_head(&zilog
->zl_lwb_list
) == NULL
);
3143 memset(zh
, 0, sizeof (zil_header_t
));
3144 memset(zilog
->zl_replayed_seq
, 0,
3145 sizeof (zilog
->zl_replayed_seq
));
3147 if (zilog
->zl_keep_first
) {
3149 * If this block was part of log chain that couldn't
3150 * be claimed because a device was missing during
3151 * zil_claim(), but that device later returns,
3152 * then this block could erroneously appear valid.
3153 * To guard against this, assign a new GUID to the new
3154 * log chain so it doesn't matter what blk points to.
3156 zil_init_log_chain(zilog
, &blk
);
3160 * A destroyed ZIL chain can't contain any TX_SETSAXATTR
3161 * records. So, deactivate the feature for this dataset.
3162 * We activate it again when we start a new ZIL chain.
3164 if (dsl_dataset_feature_is_active(ds
,
3165 SPA_FEATURE_ZILSAXATTR
))
3166 dsl_dataset_deactivate_feature(ds
,
3167 SPA_FEATURE_ZILSAXATTR
, tx
);
3171 while ((lwb
= list_head(&zilog
->zl_lwb_list
)) != NULL
) {
3172 zh
->zh_log
= lwb
->lwb_blk
;
3173 if (lwb
->lwb_buf
!= NULL
|| lwb
->lwb_max_txg
> txg
)
3175 list_remove(&zilog
->zl_lwb_list
, lwb
);
3176 zio_free(spa
, txg
, &lwb
->lwb_blk
);
3177 zil_free_lwb(zilog
, lwb
);
3180 * If we don't have anything left in the lwb list then
3181 * we've had an allocation failure and we need to zero
3182 * out the zil_header blkptr so that we don't end
3183 * up freeing the same block twice.
3185 if (list_head(&zilog
->zl_lwb_list
) == NULL
)
3186 BP_ZERO(&zh
->zh_log
);
3190 * Remove fastwrite on any blocks that have been pre-allocated for
3191 * the next commit. This prevents fastwrite counter pollution by
3192 * unused, long-lived LWBs.
3194 for (; lwb
!= NULL
; lwb
= list_next(&zilog
->zl_lwb_list
, lwb
)) {
3195 if (lwb
->lwb_fastwrite
&& !lwb
->lwb_write_zio
) {
3196 metaslab_fastwrite_unmark(zilog
->zl_spa
, &lwb
->lwb_blk
);
3197 lwb
->lwb_fastwrite
= 0;
3201 mutex_exit(&zilog
->zl_lock
);
3205 zil_lwb_cons(void *vbuf
, void *unused
, int kmflag
)
3207 (void) unused
, (void) kmflag
;
3209 list_create(&lwb
->lwb_itxs
, sizeof (itx_t
), offsetof(itx_t
, itx_node
));
3210 list_create(&lwb
->lwb_waiters
, sizeof (zil_commit_waiter_t
),
3211 offsetof(zil_commit_waiter_t
, zcw_node
));
3212 avl_create(&lwb
->lwb_vdev_tree
, zil_lwb_vdev_compare
,
3213 sizeof (zil_vdev_node_t
), offsetof(zil_vdev_node_t
, zv_node
));
3214 mutex_init(&lwb
->lwb_vdev_lock
, NULL
, MUTEX_DEFAULT
, NULL
);
3219 zil_lwb_dest(void *vbuf
, void *unused
)
3223 mutex_destroy(&lwb
->lwb_vdev_lock
);
3224 avl_destroy(&lwb
->lwb_vdev_tree
);
3225 list_destroy(&lwb
->lwb_waiters
);
3226 list_destroy(&lwb
->lwb_itxs
);
3232 zil_lwb_cache
= kmem_cache_create("zil_lwb_cache",
3233 sizeof (lwb_t
), 0, zil_lwb_cons
, zil_lwb_dest
, NULL
, NULL
, NULL
, 0);
3235 zil_zcw_cache
= kmem_cache_create("zil_zcw_cache",
3236 sizeof (zil_commit_waiter_t
), 0, NULL
, NULL
, NULL
, NULL
, NULL
, 0);
3238 zil_ksp
= kstat_create("zfs", 0, "zil", "misc",
3239 KSTAT_TYPE_NAMED
, sizeof (zil_stats
) / sizeof (kstat_named_t
),
3240 KSTAT_FLAG_VIRTUAL
);
3242 if (zil_ksp
!= NULL
) {
3243 zil_ksp
->ks_data
= &zil_stats
;
3244 kstat_install(zil_ksp
);
3251 kmem_cache_destroy(zil_zcw_cache
);
3252 kmem_cache_destroy(zil_lwb_cache
);
3254 if (zil_ksp
!= NULL
) {
3255 kstat_delete(zil_ksp
);
3261 zil_set_sync(zilog_t
*zilog
, uint64_t sync
)
3263 zilog
->zl_sync
= sync
;
3267 zil_set_logbias(zilog_t
*zilog
, uint64_t logbias
)
3269 zilog
->zl_logbias
= logbias
;
3273 zil_alloc(objset_t
*os
, zil_header_t
*zh_phys
)
3277 zilog
= kmem_zalloc(sizeof (zilog_t
), KM_SLEEP
);
3279 zilog
->zl_header
= zh_phys
;
3281 zilog
->zl_spa
= dmu_objset_spa(os
);
3282 zilog
->zl_dmu_pool
= dmu_objset_pool(os
);
3283 zilog
->zl_destroy_txg
= TXG_INITIAL
- 1;
3284 zilog
->zl_logbias
= dmu_objset_logbias(os
);
3285 zilog
->zl_sync
= dmu_objset_syncprop(os
);
3286 zilog
->zl_dirty_max_txg
= 0;
3287 zilog
->zl_last_lwb_opened
= NULL
;
3288 zilog
->zl_last_lwb_latency
= 0;
3289 zilog
->zl_max_block_size
= zil_maxblocksize
;
3291 mutex_init(&zilog
->zl_lock
, NULL
, MUTEX_DEFAULT
, NULL
);
3292 mutex_init(&zilog
->zl_issuer_lock
, NULL
, MUTEX_DEFAULT
, NULL
);
3294 for (int i
= 0; i
< TXG_SIZE
; i
++) {
3295 mutex_init(&zilog
->zl_itxg
[i
].itxg_lock
, NULL
,
3296 MUTEX_DEFAULT
, NULL
);
3299 list_create(&zilog
->zl_lwb_list
, sizeof (lwb_t
),
3300 offsetof(lwb_t
, lwb_node
));
3302 list_create(&zilog
->zl_itx_commit_list
, sizeof (itx_t
),
3303 offsetof(itx_t
, itx_node
));
3305 cv_init(&zilog
->zl_cv_suspend
, NULL
, CV_DEFAULT
, NULL
);
3311 zil_free(zilog_t
*zilog
)
3315 zilog
->zl_stop_sync
= 1;
3317 ASSERT0(zilog
->zl_suspend
);
3318 ASSERT0(zilog
->zl_suspending
);
3320 ASSERT(list_is_empty(&zilog
->zl_lwb_list
));
3321 list_destroy(&zilog
->zl_lwb_list
);
3323 ASSERT(list_is_empty(&zilog
->zl_itx_commit_list
));
3324 list_destroy(&zilog
->zl_itx_commit_list
);
3326 for (i
= 0; i
< TXG_SIZE
; i
++) {
3328 * It's possible for an itx to be generated that doesn't dirty
3329 * a txg (e.g. ztest TX_TRUNCATE). So there's no zil_clean()
3330 * callback to remove the entry. We remove those here.
3332 * Also free up the ziltest itxs.
3334 if (zilog
->zl_itxg
[i
].itxg_itxs
)
3335 zil_itxg_clean(zilog
->zl_itxg
[i
].itxg_itxs
);
3336 mutex_destroy(&zilog
->zl_itxg
[i
].itxg_lock
);
3339 mutex_destroy(&zilog
->zl_issuer_lock
);
3340 mutex_destroy(&zilog
->zl_lock
);
3342 cv_destroy(&zilog
->zl_cv_suspend
);
3344 kmem_free(zilog
, sizeof (zilog_t
));
3348 * Open an intent log.
3351 zil_open(objset_t
*os
, zil_get_data_t
*get_data
)
3353 zilog_t
*zilog
= dmu_objset_zil(os
);
3355 ASSERT3P(zilog
->zl_get_data
, ==, NULL
);
3356 ASSERT3P(zilog
->zl_last_lwb_opened
, ==, NULL
);
3357 ASSERT(list_is_empty(&zilog
->zl_lwb_list
));
3359 zilog
->zl_get_data
= get_data
;
3365 * Close an intent log.
3368 zil_close(zilog_t
*zilog
)
3373 if (!dmu_objset_is_snapshot(zilog
->zl_os
)) {
3374 zil_commit(zilog
, 0);
3376 ASSERT3P(list_tail(&zilog
->zl_lwb_list
), ==, NULL
);
3377 ASSERT0(zilog
->zl_dirty_max_txg
);
3378 ASSERT3B(zilog_is_dirty(zilog
), ==, B_FALSE
);
3381 mutex_enter(&zilog
->zl_lock
);
3382 lwb
= list_tail(&zilog
->zl_lwb_list
);
3384 txg
= zilog
->zl_dirty_max_txg
;
3386 txg
= MAX(zilog
->zl_dirty_max_txg
, lwb
->lwb_max_txg
);
3387 mutex_exit(&zilog
->zl_lock
);
3390 * We need to use txg_wait_synced() to wait long enough for the
3391 * ZIL to be clean, and to wait for all pending lwbs to be
3395 txg_wait_synced(zilog
->zl_dmu_pool
, txg
);
3397 if (zilog_is_dirty(zilog
))
3398 zfs_dbgmsg("zil (%px) is dirty, txg %llu", zilog
,
3400 if (txg
< spa_freeze_txg(zilog
->zl_spa
))
3401 VERIFY(!zilog_is_dirty(zilog
));
3403 zilog
->zl_get_data
= NULL
;
3406 * We should have only one lwb left on the list; remove it now.
3408 mutex_enter(&zilog
->zl_lock
);
3409 lwb
= list_head(&zilog
->zl_lwb_list
);
3411 ASSERT3P(lwb
, ==, list_tail(&zilog
->zl_lwb_list
));
3412 ASSERT3S(lwb
->lwb_state
, !=, LWB_STATE_ISSUED
);
3414 if (lwb
->lwb_fastwrite
)
3415 metaslab_fastwrite_unmark(zilog
->zl_spa
, &lwb
->lwb_blk
);
3417 list_remove(&zilog
->zl_lwb_list
, lwb
);
3418 zio_buf_free(lwb
->lwb_buf
, lwb
->lwb_sz
);
3419 zil_free_lwb(zilog
, lwb
);
3421 mutex_exit(&zilog
->zl_lock
);
3424 static char *suspend_tag
= "zil suspending";
3427 * Suspend an intent log. While in suspended mode, we still honor
3428 * synchronous semantics, but we rely on txg_wait_synced() to do it.
3429 * On old version pools, we suspend the log briefly when taking a
3430 * snapshot so that it will have an empty intent log.
3432 * Long holds are not really intended to be used the way we do here --
3433 * held for such a short time. A concurrent caller of dsl_dataset_long_held()
3434 * could fail. Therefore we take pains to only put a long hold if it is
3435 * actually necessary. Fortunately, it will only be necessary if the
3436 * objset is currently mounted (or the ZVOL equivalent). In that case it
3437 * will already have a long hold, so we are not really making things any worse.
3439 * Ideally, we would locate the existing long-holder (i.e. the zfsvfs_t or
3440 * zvol_state_t), and use their mechanism to prevent their hold from being
3441 * dropped (e.g. VFS_HOLD()). However, that would be even more pain for
3444 * if cookiep == NULL, this does both the suspend & resume.
3445 * Otherwise, it returns with the dataset "long held", and the cookie
3446 * should be passed into zil_resume().
3449 zil_suspend(const char *osname
, void **cookiep
)
3453 const zil_header_t
*zh
;
3456 error
= dmu_objset_hold(osname
, suspend_tag
, &os
);
3459 zilog
= dmu_objset_zil(os
);
3461 mutex_enter(&zilog
->zl_lock
);
3462 zh
= zilog
->zl_header
;
3464 if (zh
->zh_flags
& ZIL_REPLAY_NEEDED
) { /* unplayed log */
3465 mutex_exit(&zilog
->zl_lock
);
3466 dmu_objset_rele(os
, suspend_tag
);
3467 return (SET_ERROR(EBUSY
));
3471 * Don't put a long hold in the cases where we can avoid it. This
3472 * is when there is no cookie so we are doing a suspend & resume
3473 * (i.e. called from zil_vdev_offline()), and there's nothing to do
3474 * for the suspend because it's already suspended, or there's no ZIL.
3476 if (cookiep
== NULL
&& !zilog
->zl_suspending
&&
3477 (zilog
->zl_suspend
> 0 || BP_IS_HOLE(&zh
->zh_log
))) {
3478 mutex_exit(&zilog
->zl_lock
);
3479 dmu_objset_rele(os
, suspend_tag
);
3483 dsl_dataset_long_hold(dmu_objset_ds(os
), suspend_tag
);
3484 dsl_pool_rele(dmu_objset_pool(os
), suspend_tag
);
3486 zilog
->zl_suspend
++;
3488 if (zilog
->zl_suspend
> 1) {
3490 * Someone else is already suspending it.
3491 * Just wait for them to finish.
3494 while (zilog
->zl_suspending
)
3495 cv_wait(&zilog
->zl_cv_suspend
, &zilog
->zl_lock
);
3496 mutex_exit(&zilog
->zl_lock
);
3498 if (cookiep
== NULL
)
3506 * If there is no pointer to an on-disk block, this ZIL must not
3507 * be active (e.g. filesystem not mounted), so there's nothing
3510 if (BP_IS_HOLE(&zh
->zh_log
)) {
3511 ASSERT(cookiep
!= NULL
); /* fast path already handled */
3514 mutex_exit(&zilog
->zl_lock
);
3519 * The ZIL has work to do. Ensure that the associated encryption
3520 * key will remain mapped while we are committing the log by
3521 * grabbing a reference to it. If the key isn't loaded we have no
3522 * choice but to return an error until the wrapping key is loaded.
3524 if (os
->os_encrypted
&&
3525 dsl_dataset_create_key_mapping(dmu_objset_ds(os
)) != 0) {
3526 zilog
->zl_suspend
--;
3527 mutex_exit(&zilog
->zl_lock
);
3528 dsl_dataset_long_rele(dmu_objset_ds(os
), suspend_tag
);
3529 dsl_dataset_rele(dmu_objset_ds(os
), suspend_tag
);
3530 return (SET_ERROR(EACCES
));
3533 zilog
->zl_suspending
= B_TRUE
;
3534 mutex_exit(&zilog
->zl_lock
);
3537 * We need to use zil_commit_impl to ensure we wait for all
3538 * LWB_STATE_OPENED and LWB_STATE_ISSUED lwbs to be committed
3539 * to disk before proceeding. If we used zil_commit instead, it
3540 * would just call txg_wait_synced(), because zl_suspend is set.
3541 * txg_wait_synced() doesn't wait for these lwb's to be
3542 * LWB_STATE_FLUSH_DONE before returning.
3544 zil_commit_impl(zilog
, 0);
3547 * Now that we've ensured all lwb's are LWB_STATE_FLUSH_DONE, we
3548 * use txg_wait_synced() to ensure the data from the zilog has
3549 * migrated to the main pool before calling zil_destroy().
3551 txg_wait_synced(zilog
->zl_dmu_pool
, 0);
3553 zil_destroy(zilog
, B_FALSE
);
3555 mutex_enter(&zilog
->zl_lock
);
3556 zilog
->zl_suspending
= B_FALSE
;
3557 cv_broadcast(&zilog
->zl_cv_suspend
);
3558 mutex_exit(&zilog
->zl_lock
);
3560 if (os
->os_encrypted
)
3561 dsl_dataset_remove_key_mapping(dmu_objset_ds(os
));
3563 if (cookiep
== NULL
)
3571 zil_resume(void *cookie
)
3573 objset_t
*os
= cookie
;
3574 zilog_t
*zilog
= dmu_objset_zil(os
);
3576 mutex_enter(&zilog
->zl_lock
);
3577 ASSERT(zilog
->zl_suspend
!= 0);
3578 zilog
->zl_suspend
--;
3579 mutex_exit(&zilog
->zl_lock
);
3580 dsl_dataset_long_rele(dmu_objset_ds(os
), suspend_tag
);
3581 dsl_dataset_rele(dmu_objset_ds(os
), suspend_tag
);
3584 typedef struct zil_replay_arg
{
3585 zil_replay_func_t
*const *zr_replay
;
3587 boolean_t zr_byteswap
;
3592 zil_replay_error(zilog_t
*zilog
, const lr_t
*lr
, int error
)
3594 char name
[ZFS_MAX_DATASET_NAME_LEN
];
3596 zilog
->zl_replaying_seq
--; /* didn't actually replay this one */
3598 dmu_objset_name(zilog
->zl_os
, name
);
3600 cmn_err(CE_WARN
, "ZFS replay transaction error %d, "
3601 "dataset %s, seq 0x%llx, txtype %llu %s\n", error
, name
,
3602 (u_longlong_t
)lr
->lrc_seq
,
3603 (u_longlong_t
)(lr
->lrc_txtype
& ~TX_CI
),
3604 (lr
->lrc_txtype
& TX_CI
) ? "CI" : "");
3610 zil_replay_log_record(zilog_t
*zilog
, const lr_t
*lr
, void *zra
,
3613 zil_replay_arg_t
*zr
= zra
;
3614 const zil_header_t
*zh
= zilog
->zl_header
;
3615 uint64_t reclen
= lr
->lrc_reclen
;
3616 uint64_t txtype
= lr
->lrc_txtype
;
3619 zilog
->zl_replaying_seq
= lr
->lrc_seq
;
3621 if (lr
->lrc_seq
<= zh
->zh_replay_seq
) /* already replayed */
3624 if (lr
->lrc_txg
< claim_txg
) /* already committed */
3627 /* Strip case-insensitive bit, still present in log record */
3630 if (txtype
== 0 || txtype
>= TX_MAX_TYPE
)
3631 return (zil_replay_error(zilog
, lr
, EINVAL
));
3634 * If this record type can be logged out of order, the object
3635 * (lr_foid) may no longer exist. That's legitimate, not an error.
3637 if (TX_OOO(txtype
)) {
3638 error
= dmu_object_info(zilog
->zl_os
,
3639 LR_FOID_GET_OBJ(((lr_ooo_t
*)lr
)->lr_foid
), NULL
);
3640 if (error
== ENOENT
|| error
== EEXIST
)
3645 * Make a copy of the data so we can revise and extend it.
3647 memcpy(zr
->zr_lr
, lr
, reclen
);
3650 * If this is a TX_WRITE with a blkptr, suck in the data.
3652 if (txtype
== TX_WRITE
&& reclen
== sizeof (lr_write_t
)) {
3653 error
= zil_read_log_data(zilog
, (lr_write_t
*)lr
,
3654 zr
->zr_lr
+ reclen
);
3656 return (zil_replay_error(zilog
, lr
, error
));
3660 * The log block containing this lr may have been byteswapped
3661 * so that we can easily examine common fields like lrc_txtype.
3662 * However, the log is a mix of different record types, and only the
3663 * replay vectors know how to byteswap their records. Therefore, if
3664 * the lr was byteswapped, undo it before invoking the replay vector.
3666 if (zr
->zr_byteswap
)
3667 byteswap_uint64_array(zr
->zr_lr
, reclen
);
3670 * We must now do two things atomically: replay this log record,
3671 * and update the log header sequence number to reflect the fact that
3672 * we did so. At the end of each replay function the sequence number
3673 * is updated if we are in replay mode.
3675 error
= zr
->zr_replay
[txtype
](zr
->zr_arg
, zr
->zr_lr
, zr
->zr_byteswap
);
3678 * The DMU's dnode layer doesn't see removes until the txg
3679 * commits, so a subsequent claim can spuriously fail with
3680 * EEXIST. So if we receive any error we try syncing out
3681 * any removes then retry the transaction. Note that we
3682 * specify B_FALSE for byteswap now, so we don't do it twice.
3684 txg_wait_synced(spa_get_dsl(zilog
->zl_spa
), 0);
3685 error
= zr
->zr_replay
[txtype
](zr
->zr_arg
, zr
->zr_lr
, B_FALSE
);
3687 return (zil_replay_error(zilog
, lr
, error
));
3693 zil_incr_blks(zilog_t
*zilog
, const blkptr_t
*bp
, void *arg
, uint64_t claim_txg
)
3695 (void) bp
, (void) arg
, (void) claim_txg
;
3697 zilog
->zl_replay_blks
++;
3703 * If this dataset has a non-empty intent log, replay it and destroy it.
3706 zil_replay(objset_t
*os
, void *arg
,
3707 zil_replay_func_t
*const replay_func
[TX_MAX_TYPE
])
3709 zilog_t
*zilog
= dmu_objset_zil(os
);
3710 const zil_header_t
*zh
= zilog
->zl_header
;
3711 zil_replay_arg_t zr
;
3713 if ((zh
->zh_flags
& ZIL_REPLAY_NEEDED
) == 0) {
3714 zil_destroy(zilog
, B_TRUE
);
3718 zr
.zr_replay
= replay_func
;
3720 zr
.zr_byteswap
= BP_SHOULD_BYTESWAP(&zh
->zh_log
);
3721 zr
.zr_lr
= vmem_alloc(2 * SPA_MAXBLOCKSIZE
, KM_SLEEP
);
3724 * Wait for in-progress removes to sync before starting replay.
3726 txg_wait_synced(zilog
->zl_dmu_pool
, 0);
3728 zilog
->zl_replay
= B_TRUE
;
3729 zilog
->zl_replay_time
= ddi_get_lbolt();
3730 ASSERT(zilog
->zl_replay_blks
== 0);
3731 (void) zil_parse(zilog
, zil_incr_blks
, zil_replay_log_record
, &zr
,
3732 zh
->zh_claim_txg
, B_TRUE
);
3733 vmem_free(zr
.zr_lr
, 2 * SPA_MAXBLOCKSIZE
);
3735 zil_destroy(zilog
, B_FALSE
);
3736 txg_wait_synced(zilog
->zl_dmu_pool
, zilog
->zl_destroy_txg
);
3737 zilog
->zl_replay
= B_FALSE
;
3741 zil_replaying(zilog_t
*zilog
, dmu_tx_t
*tx
)
3743 if (zilog
->zl_sync
== ZFS_SYNC_DISABLED
)
3746 if (zilog
->zl_replay
) {
3747 dsl_dataset_dirty(dmu_objset_ds(zilog
->zl_os
), tx
);
3748 zilog
->zl_replayed_seq
[dmu_tx_get_txg(tx
) & TXG_MASK
] =
3749 zilog
->zl_replaying_seq
;
3757 zil_reset(const char *osname
, void *arg
)
3761 int error
= zil_suspend(osname
, NULL
);
3762 /* EACCES means crypto key not loaded */
3763 if ((error
== EACCES
) || (error
== EBUSY
))
3764 return (SET_ERROR(error
));
3766 return (SET_ERROR(EEXIST
));
3770 EXPORT_SYMBOL(zil_alloc
);
3771 EXPORT_SYMBOL(zil_free
);
3772 EXPORT_SYMBOL(zil_open
);
3773 EXPORT_SYMBOL(zil_close
);
3774 EXPORT_SYMBOL(zil_replay
);
3775 EXPORT_SYMBOL(zil_replaying
);
3776 EXPORT_SYMBOL(zil_destroy
);
3777 EXPORT_SYMBOL(zil_destroy_sync
);
3778 EXPORT_SYMBOL(zil_itx_create
);
3779 EXPORT_SYMBOL(zil_itx_destroy
);
3780 EXPORT_SYMBOL(zil_itx_assign
);
3781 EXPORT_SYMBOL(zil_commit
);
3782 EXPORT_SYMBOL(zil_claim
);
3783 EXPORT_SYMBOL(zil_check_log_chain
);
3784 EXPORT_SYMBOL(zil_sync
);
3785 EXPORT_SYMBOL(zil_clean
);
3786 EXPORT_SYMBOL(zil_suspend
);
3787 EXPORT_SYMBOL(zil_resume
);
3788 EXPORT_SYMBOL(zil_lwb_add_block
);
3789 EXPORT_SYMBOL(zil_bp_tree_add
);
3790 EXPORT_SYMBOL(zil_set_sync
);
3791 EXPORT_SYMBOL(zil_set_logbias
);
3793 ZFS_MODULE_PARAM(zfs
, zfs_
, commit_timeout_pct
, INT
, ZMOD_RW
,
3794 "ZIL block open timeout percentage");
3796 ZFS_MODULE_PARAM(zfs_zil
, zil_
, replay_disable
, INT
, ZMOD_RW
,
3797 "Disable intent logging replay");
3799 ZFS_MODULE_PARAM(zfs_zil
, zil_
, nocacheflush
, INT
, ZMOD_RW
,
3800 "Disable ZIL cache flushes");
3802 ZFS_MODULE_PARAM(zfs_zil
, zil_
, slog_bulk
, ULONG
, ZMOD_RW
,
3803 "Limit in bytes slog sync writes per commit");
3805 ZFS_MODULE_PARAM(zfs_zil
, zil_
, maxblocksize
, INT
, ZMOD_RW
,
3806 "Limit in bytes of ZIL log block size");