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
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15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
22 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
26 #include <sys/zfs_context.h>
32 #include <sys/resource.h>
34 #include <sys/zil_impl.h>
35 #include <sys/dsl_dataset.h>
37 #include <sys/dmu_tx.h>
40 * The zfs intent log (ZIL) saves transaction records of system calls
41 * that change the file system in memory with enough information
42 * to be able to replay them. These are stored in memory until
43 * either the DMU transaction group (txg) commits them to the stable pool
44 * and they can be discarded, or they are flushed to the stable log
45 * (also in the pool) due to a fsync, O_DSYNC or other synchronous
46 * requirement. In the event of a panic or power fail then those log
47 * records (transactions) are replayed.
49 * There is one ZIL per file system. Its on-disk (pool) format consists
56 * A log record holds a system call transaction. Log blocks can
57 * hold many log records and the blocks are chained together.
58 * Each ZIL block contains a block pointer (blkptr_t) to the next
59 * ZIL block in the chain. The ZIL header points to the first
60 * block in the chain. Note there is not a fixed place in the pool
61 * to hold blocks. They are dynamically allocated and freed as
62 * needed from the blocks available. Figure X shows the ZIL structure:
66 * This global ZIL switch affects all pools
68 int zil_disable = 0; /* disable intent logging */
69 SYSCTL_DECL(_vfs_zfs);
70 TUNABLE_INT("vfs.zfs.zil_disable", &zil_disable);
71 SYSCTL_INT(_vfs_zfs, OID_AUTO, zil_disable, CTLFLAG_RW, &zil_disable, 0,
72 "Disable ZFS Intent Log (ZIL)");
75 * Tunable parameter for debugging or performance analysis. Setting
76 * zfs_nocacheflush will cause corruption on power loss if a volatile
77 * out-of-order write cache is enabled.
79 boolean_t zfs_nocacheflush = B_FALSE;
80 TUNABLE_INT("vfs.zfs.cache_flush_disable", &zfs_nocacheflush);
81 SYSCTL_INT(_vfs_zfs, OID_AUTO, cache_flush_disable, CTLFLAG_RDTUN,
82 &zfs_nocacheflush, 0, "Disable cache flush");
84 static kmem_cache_t *zil_lwb_cache;
87 zil_dva_compare(const void *x1, const void *x2)
89 const dva_t *dva1 = x1;
90 const dva_t *dva2 = x2;
92 if (DVA_GET_VDEV(dva1) < DVA_GET_VDEV(dva2))
94 if (DVA_GET_VDEV(dva1) > DVA_GET_VDEV(dva2))
97 if (DVA_GET_OFFSET(dva1) < DVA_GET_OFFSET(dva2))
99 if (DVA_GET_OFFSET(dva1) > DVA_GET_OFFSET(dva2))
106 zil_dva_tree_init(avl_tree_t *t)
108 avl_create(t, zil_dva_compare, sizeof (zil_dva_node_t),
109 offsetof(zil_dva_node_t, zn_node));
113 zil_dva_tree_fini(avl_tree_t *t)
118 while ((zn = avl_destroy_nodes(t, &cookie)) != NULL)
119 kmem_free(zn, sizeof (zil_dva_node_t));
125 zil_dva_tree_add(avl_tree_t *t, dva_t *dva)
130 if (avl_find(t, dva, &where) != NULL)
133 zn = kmem_alloc(sizeof (zil_dva_node_t), KM_SLEEP);
135 avl_insert(t, zn, where);
140 static zil_header_t *
141 zil_header_in_syncing_context(zilog_t *zilog)
143 return ((zil_header_t *)zilog->zl_header);
147 zil_init_log_chain(zilog_t *zilog, blkptr_t *bp)
149 zio_cksum_t *zc = &bp->blk_cksum;
151 zc->zc_word[ZIL_ZC_GUID_0] = spa_get_random(-1ULL);
152 zc->zc_word[ZIL_ZC_GUID_1] = spa_get_random(-1ULL);
153 zc->zc_word[ZIL_ZC_OBJSET] = dmu_objset_id(zilog->zl_os);
154 zc->zc_word[ZIL_ZC_SEQ] = 1ULL;
158 * Read a log block, make sure it's valid, and byteswap it if necessary.
161 zil_read_log_block(zilog_t *zilog, const blkptr_t *bp, arc_buf_t **abufpp)
165 uint32_t aflags = ARC_WAIT;
168 zb.zb_objset = bp->blk_cksum.zc_word[ZIL_ZC_OBJSET];
171 zb.zb_blkid = bp->blk_cksum.zc_word[ZIL_ZC_SEQ];
176 * We shouldn't be doing any scrubbing while we're doing log
177 * replay, it's OK to not lock.
179 error = arc_read_nolock(NULL, zilog->zl_spa, &blk,
180 arc_getbuf_func, abufpp, ZIO_PRIORITY_SYNC_READ, ZIO_FLAG_CANFAIL |
181 ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB, &aflags, &zb);
184 char *data = (*abufpp)->b_data;
185 uint64_t blksz = BP_GET_LSIZE(bp);
186 zil_trailer_t *ztp = (zil_trailer_t *)(data + blksz) - 1;
187 zio_cksum_t cksum = bp->blk_cksum;
190 * Validate the checksummed log block.
192 * Sequence numbers should be... sequential. The checksum
193 * verifier for the next block should be bp's checksum plus 1.
195 * Also check the log chain linkage and size used.
197 cksum.zc_word[ZIL_ZC_SEQ]++;
199 if (bcmp(&cksum, &ztp->zit_next_blk.blk_cksum,
200 sizeof (cksum)) || BP_IS_HOLE(&ztp->zit_next_blk) ||
201 (ztp->zit_nused > (blksz - sizeof (zil_trailer_t)))) {
206 VERIFY(arc_buf_remove_ref(*abufpp, abufpp) == 1);
211 dprintf("error %d on %llu:%llu\n", error, zb.zb_objset, zb.zb_blkid);
217 * Parse the intent log, and call parse_func for each valid record within.
218 * Return the highest sequence number.
221 zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func,
222 zil_parse_lr_func_t *parse_lr_func, void *arg, uint64_t txg)
224 const zil_header_t *zh = zilog->zl_header;
225 uint64_t claim_seq = zh->zh_claim_seq;
227 uint64_t max_seq = 0;
228 blkptr_t blk = zh->zh_log;
234 if (BP_IS_HOLE(&blk))
238 * Starting at the block pointed to by zh_log we read the log chain.
239 * For each block in the chain we strongly check that block to
240 * ensure its validity. We stop when an invalid block is found.
241 * For each block pointer in the chain we call parse_blk_func().
242 * For each record in each valid block we call parse_lr_func().
243 * If the log has been claimed, stop if we encounter a sequence
244 * number greater than the highest claimed sequence number.
246 zil_dva_tree_init(&zilog->zl_dva_tree);
248 seq = blk.blk_cksum.zc_word[ZIL_ZC_SEQ];
250 if (claim_seq != 0 && seq > claim_seq)
253 ASSERT(max_seq < seq);
256 error = zil_read_log_block(zilog, &blk, &abuf);
258 if (parse_blk_func != NULL)
259 parse_blk_func(zilog, &blk, arg, txg);
264 lrbuf = abuf->b_data;
265 ztp = (zil_trailer_t *)(lrbuf + BP_GET_LSIZE(&blk)) - 1;
266 blk = ztp->zit_next_blk;
268 if (parse_lr_func == NULL) {
269 VERIFY(arc_buf_remove_ref(abuf, &abuf) == 1);
273 for (lrp = lrbuf; lrp < lrbuf + ztp->zit_nused; lrp += reclen) {
274 lr_t *lr = (lr_t *)lrp;
275 reclen = lr->lrc_reclen;
276 ASSERT3U(reclen, >=, sizeof (lr_t));
277 parse_lr_func(zilog, lr, arg, txg);
279 VERIFY(arc_buf_remove_ref(abuf, &abuf) == 1);
281 zil_dva_tree_fini(&zilog->zl_dva_tree);
288 zil_claim_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t first_txg)
290 spa_t *spa = zilog->zl_spa;
294 * Claim log block if not already committed and not already claimed.
296 if (bp->blk_birth >= first_txg &&
297 zil_dva_tree_add(&zilog->zl_dva_tree, BP_IDENTITY(bp)) == 0) {
298 err = zio_wait(zio_claim(NULL, spa, first_txg, bp, NULL, NULL,
299 ZIO_FLAG_MUSTSUCCEED));
305 zil_claim_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t first_txg)
307 if (lrc->lrc_txtype == TX_WRITE) {
308 lr_write_t *lr = (lr_write_t *)lrc;
309 zil_claim_log_block(zilog, &lr->lr_blkptr, tx, first_txg);
315 zil_free_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t claim_txg)
317 zio_free_blk(zilog->zl_spa, bp, dmu_tx_get_txg(tx));
321 zil_free_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t claim_txg)
324 * If we previously claimed it, we need to free it.
326 if (claim_txg != 0 && lrc->lrc_txtype == TX_WRITE) {
327 lr_write_t *lr = (lr_write_t *)lrc;
328 blkptr_t *bp = &lr->lr_blkptr;
329 if (bp->blk_birth >= claim_txg &&
330 !zil_dva_tree_add(&zilog->zl_dva_tree, BP_IDENTITY(bp))) {
331 (void) arc_free(NULL, zilog->zl_spa,
332 dmu_tx_get_txg(tx), bp, NULL, NULL, ARC_WAIT);
338 * Create an on-disk intent log.
341 zil_create(zilog_t *zilog)
343 const zil_header_t *zh = zilog->zl_header;
351 * Wait for any previous destroy to complete.
353 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg);
355 ASSERT(zh->zh_claim_txg == 0);
356 ASSERT(zh->zh_replay_seq == 0);
361 * If we don't already have an initial log block, allocate one now.
363 if (BP_IS_HOLE(&blk)) {
364 tx = dmu_tx_create(zilog->zl_os);
365 (void) dmu_tx_assign(tx, TXG_WAIT);
366 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
367 txg = dmu_tx_get_txg(tx);
369 error = zio_alloc_blk(zilog->zl_spa, ZIL_MIN_BLKSZ, &blk,
373 zil_init_log_chain(zilog, &blk);
377 * Allocate a log write buffer (lwb) for the first log block.
380 lwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP);
381 lwb->lwb_zilog = zilog;
384 lwb->lwb_sz = BP_GET_LSIZE(&lwb->lwb_blk);
385 lwb->lwb_buf = zio_buf_alloc(lwb->lwb_sz);
386 lwb->lwb_max_txg = txg;
389 mutex_enter(&zilog->zl_lock);
390 list_insert_tail(&zilog->zl_lwb_list, lwb);
391 mutex_exit(&zilog->zl_lock);
395 * If we just allocated the first log block, commit our transaction
396 * and wait for zil_sync() to stuff the block poiner into zh_log.
397 * (zh is part of the MOS, so we cannot modify it in open context.)
401 txg_wait_synced(zilog->zl_dmu_pool, txg);
404 ASSERT(bcmp(&blk, &zh->zh_log, sizeof (blk)) == 0);
408 * In one tx, free all log blocks and clear the log header.
409 * If keep_first is set, then we're replaying a log with no content.
410 * We want to keep the first block, however, so that the first
411 * synchronous transaction doesn't require a txg_wait_synced()
412 * in zil_create(). We don't need to txg_wait_synced() here either
413 * when keep_first is set, because both zil_create() and zil_destroy()
414 * will wait for any in-progress destroys to complete.
417 zil_destroy(zilog_t *zilog, boolean_t keep_first)
419 const zil_header_t *zh = zilog->zl_header;
425 * Wait for any previous destroy to complete.
427 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg);
429 if (BP_IS_HOLE(&zh->zh_log))
432 tx = dmu_tx_create(zilog->zl_os);
433 (void) dmu_tx_assign(tx, TXG_WAIT);
434 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
435 txg = dmu_tx_get_txg(tx);
437 mutex_enter(&zilog->zl_lock);
440 * It is possible for the ZIL to get the previously mounted zilog
441 * structure of the same dataset if quickly remounted and the dbuf
442 * eviction has not completed. In this case we can see a non
443 * empty lwb list and keep_first will be set. We fix this by
444 * clearing the keep_first. This will be slower but it's very rare.
446 if (!list_is_empty(&zilog->zl_lwb_list) && keep_first)
447 keep_first = B_FALSE;
449 ASSERT3U(zilog->zl_destroy_txg, <, txg);
450 zilog->zl_destroy_txg = txg;
451 zilog->zl_keep_first = keep_first;
453 if (!list_is_empty(&zilog->zl_lwb_list)) {
454 ASSERT(zh->zh_claim_txg == 0);
456 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) {
457 list_remove(&zilog->zl_lwb_list, lwb);
458 if (lwb->lwb_buf != NULL)
459 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
460 zio_free_blk(zilog->zl_spa, &lwb->lwb_blk, txg);
461 kmem_cache_free(zil_lwb_cache, lwb);
465 (void) zil_parse(zilog, zil_free_log_block,
466 zil_free_log_record, tx, zh->zh_claim_txg);
469 mutex_exit(&zilog->zl_lock);
475 * zil_rollback_destroy() is only called by the rollback code.
476 * We already have a syncing tx. Rollback has exclusive access to the
477 * dataset, so we don't have to worry about concurrent zil access.
478 * The actual freeing of any log blocks occurs in zil_sync() later in
479 * this txg syncing phase.
482 zil_rollback_destroy(zilog_t *zilog, dmu_tx_t *tx)
484 const zil_header_t *zh = zilog->zl_header;
487 if (BP_IS_HOLE(&zh->zh_log))
490 txg = dmu_tx_get_txg(tx);
491 ASSERT3U(zilog->zl_destroy_txg, <, txg);
492 zilog->zl_destroy_txg = txg;
493 zilog->zl_keep_first = B_FALSE;
496 * Ensure there's no outstanding ZIL IO. No lwbs or just the
497 * unused one that allocated in advance is ok.
499 ASSERT(zilog->zl_lwb_list.list_head.list_next ==
500 zilog->zl_lwb_list.list_head.list_prev);
501 (void) zil_parse(zilog, zil_free_log_block, zil_free_log_record,
502 tx, zh->zh_claim_txg);
506 zil_claim(char *osname, void *txarg)
508 dmu_tx_t *tx = txarg;
509 uint64_t first_txg = dmu_tx_get_txg(tx);
515 error = dmu_objset_open(osname, DMU_OST_ANY, DS_MODE_USER, &os);
517 cmn_err(CE_WARN, "can't open objset for %s", osname);
521 zilog = dmu_objset_zil(os);
522 zh = zil_header_in_syncing_context(zilog);
525 * Claim all log blocks if we haven't already done so, and remember
526 * the highest claimed sequence number. This ensures that if we can
527 * read only part of the log now (e.g. due to a missing device),
528 * but we can read the entire log later, we will not try to replay
529 * or destroy beyond the last block we successfully claimed.
531 ASSERT3U(zh->zh_claim_txg, <=, first_txg);
532 if (zh->zh_claim_txg == 0 && !BP_IS_HOLE(&zh->zh_log)) {
533 zh->zh_claim_txg = first_txg;
534 zh->zh_claim_seq = zil_parse(zilog, zil_claim_log_block,
535 zil_claim_log_record, tx, first_txg);
536 dsl_dataset_dirty(dmu_objset_ds(os), tx);
539 ASSERT3U(first_txg, ==, (spa_last_synced_txg(zilog->zl_spa) + 1));
540 dmu_objset_close(os);
545 * Check the log by walking the log chain.
546 * Checksum errors are ok as they indicate the end of the chain.
547 * Any other error (no device or read failure) returns an error.
551 zil_check_log_chain(char *osname, void *txarg)
562 error = dmu_objset_open(osname, DMU_OST_ANY, DS_MODE_USER, &os);
564 cmn_err(CE_WARN, "can't open objset for %s", osname);
568 zilog = dmu_objset_zil(os);
569 zh = zil_header_in_syncing_context(zilog);
571 if (BP_IS_HOLE(&blk)) {
572 dmu_objset_close(os);
573 return (0); /* no chain */
577 error = zil_read_log_block(zilog, &blk, &abuf);
580 lrbuf = abuf->b_data;
581 ztp = (zil_trailer_t *)(lrbuf + BP_GET_LSIZE(&blk)) - 1;
582 blk = ztp->zit_next_blk;
583 VERIFY(arc_buf_remove_ref(abuf, &abuf) == 1);
585 dmu_objset_close(os);
587 return (0); /* normal end of chain */
596 zil_clear_log_chain(char *osname, void *txarg)
604 error = dmu_objset_open(osname, DMU_OST_ANY, DS_MODE_USER, &os);
606 cmn_err(CE_WARN, "can't open objset for %s", osname);
610 zilog = dmu_objset_zil(os);
611 tx = dmu_tx_create(zilog->zl_os);
612 (void) dmu_tx_assign(tx, TXG_WAIT);
613 zh = zil_header_in_syncing_context(zilog);
614 BP_ZERO(&zh->zh_log);
615 dsl_dataset_dirty(dmu_objset_ds(os), tx);
617 dmu_objset_close(os);
622 zil_vdev_compare(const void *x1, const void *x2)
624 uint64_t v1 = ((zil_vdev_node_t *)x1)->zv_vdev;
625 uint64_t v2 = ((zil_vdev_node_t *)x2)->zv_vdev;
636 zil_add_block(zilog_t *zilog, blkptr_t *bp)
638 avl_tree_t *t = &zilog->zl_vdev_tree;
640 zil_vdev_node_t *zv, zvsearch;
641 int ndvas = BP_GET_NDVAS(bp);
644 if (zfs_nocacheflush)
647 ASSERT(zilog->zl_writer);
650 * Even though we're zl_writer, we still need a lock because the
651 * zl_get_data() callbacks may have dmu_sync() done callbacks
652 * that will run concurrently.
654 mutex_enter(&zilog->zl_vdev_lock);
655 for (i = 0; i < ndvas; i++) {
656 zvsearch.zv_vdev = DVA_GET_VDEV(&bp->blk_dva[i]);
657 if (avl_find(t, &zvsearch, &where) == NULL) {
658 zv = kmem_alloc(sizeof (*zv), KM_SLEEP);
659 zv->zv_vdev = zvsearch.zv_vdev;
660 avl_insert(t, zv, where);
663 mutex_exit(&zilog->zl_vdev_lock);
667 zil_flush_vdevs(zilog_t *zilog)
669 spa_t *spa = zilog->zl_spa;
670 avl_tree_t *t = &zilog->zl_vdev_tree;
675 ASSERT(zilog->zl_writer);
678 * We don't need zl_vdev_lock here because we're the zl_writer,
679 * and all zl_get_data() callbacks are done.
681 if (avl_numnodes(t) == 0)
684 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
686 zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
688 while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) {
689 vdev_t *vd = vdev_lookup_top(spa, zv->zv_vdev);
692 kmem_free(zv, sizeof (*zv));
696 * Wait for all the flushes to complete. Not all devices actually
697 * support the DKIOCFLUSHWRITECACHE ioctl, so it's OK if it fails.
699 (void) zio_wait(zio);
701 spa_config_exit(spa, SCL_STATE, FTAG);
705 * Function called when a log block write completes
708 zil_lwb_write_done(zio_t *zio)
710 lwb_t *lwb = zio->io_private;
711 zilog_t *zilog = lwb->lwb_zilog;
713 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF);
714 ASSERT(BP_GET_CHECKSUM(zio->io_bp) == ZIO_CHECKSUM_ZILOG);
715 ASSERT(BP_GET_TYPE(zio->io_bp) == DMU_OT_INTENT_LOG);
716 ASSERT(BP_GET_LEVEL(zio->io_bp) == 0);
717 ASSERT(BP_GET_BYTEORDER(zio->io_bp) == ZFS_HOST_BYTEORDER);
718 ASSERT(!BP_IS_GANG(zio->io_bp));
719 ASSERT(!BP_IS_HOLE(zio->io_bp));
720 ASSERT(zio->io_bp->blk_fill == 0);
723 * Now that we've written this log block, we have a stable pointer
724 * to the next block in the chain, so it's OK to let the txg in
725 * which we allocated the next block sync.
727 txg_rele_to_sync(&lwb->lwb_txgh);
729 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
730 mutex_enter(&zilog->zl_lock);
733 zilog->zl_log_error = B_TRUE;
734 mutex_exit(&zilog->zl_lock);
738 * Initialize the io for a log block.
741 zil_lwb_write_init(zilog_t *zilog, lwb_t *lwb)
745 zb.zb_objset = lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_OBJSET];
748 zb.zb_blkid = lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_SEQ];
750 if (zilog->zl_root_zio == NULL) {
751 zilog->zl_root_zio = zio_root(zilog->zl_spa, NULL, NULL,
754 if (lwb->lwb_zio == NULL) {
755 lwb->lwb_zio = zio_rewrite(zilog->zl_root_zio, zilog->zl_spa,
756 0, &lwb->lwb_blk, lwb->lwb_buf,
757 lwb->lwb_sz, zil_lwb_write_done, lwb,
758 ZIO_PRIORITY_LOG_WRITE, ZIO_FLAG_CANFAIL, &zb);
763 * Start a log block write and advance to the next log block.
764 * Calls are serialized.
767 zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb)
770 zil_trailer_t *ztp = (zil_trailer_t *)(lwb->lwb_buf + lwb->lwb_sz) - 1;
771 spa_t *spa = zilog->zl_spa;
772 blkptr_t *bp = &ztp->zit_next_blk;
777 ASSERT(lwb->lwb_nused <= ZIL_BLK_DATA_SZ(lwb));
780 * Allocate the next block and save its address in this block
781 * before writing it in order to establish the log chain.
782 * Note that if the allocation of nlwb synced before we wrote
783 * the block that points at it (lwb), we'd leak it if we crashed.
784 * Therefore, we don't do txg_rele_to_sync() until zil_lwb_write_done().
786 txg = txg_hold_open(zilog->zl_dmu_pool, &lwb->lwb_txgh);
787 txg_rele_to_quiesce(&lwb->lwb_txgh);
790 * Pick a ZIL blocksize. We request a size that is the
791 * maximum of the previous used size, the current used size and
792 * the amount waiting in the queue.
794 zil_blksz = MAX(zilog->zl_prev_used,
795 zilog->zl_cur_used + sizeof (*ztp));
796 zil_blksz = MAX(zil_blksz, zilog->zl_itx_list_sz + sizeof (*ztp));
797 zil_blksz = P2ROUNDUP_TYPED(zil_blksz, ZIL_MIN_BLKSZ, uint64_t);
798 if (zil_blksz > ZIL_MAX_BLKSZ)
799 zil_blksz = ZIL_MAX_BLKSZ;
802 /* pass the old blkptr in order to spread log blocks across devs */
803 error = zio_alloc_blk(spa, zil_blksz, bp, &lwb->lwb_blk, txg);
805 dmu_tx_t *tx = dmu_tx_create_assigned(zilog->zl_dmu_pool, txg);
808 * We dirty the dataset to ensure that zil_sync() will
809 * be called to remove this lwb from our zl_lwb_list.
810 * Failing to do so, may leave an lwb with a NULL lwb_buf
811 * hanging around on the zl_lwb_list.
813 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
817 * Since we've just experienced an allocation failure so we
818 * terminate the current lwb and send it on its way.
821 ztp->zit_nused = lwb->lwb_nused;
822 ztp->zit_bt.zbt_cksum = lwb->lwb_blk.blk_cksum;
823 zio_nowait(lwb->lwb_zio);
826 * By returning NULL the caller will call tx_wait_synced()
831 ASSERT3U(bp->blk_birth, ==, txg);
833 ztp->zit_nused = lwb->lwb_nused;
834 ztp->zit_bt.zbt_cksum = lwb->lwb_blk.blk_cksum;
835 bp->blk_cksum = lwb->lwb_blk.blk_cksum;
836 bp->blk_cksum.zc_word[ZIL_ZC_SEQ]++;
839 * Allocate a new log write buffer (lwb).
841 nlwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP);
843 nlwb->lwb_zilog = zilog;
846 nlwb->lwb_sz = BP_GET_LSIZE(&nlwb->lwb_blk);
847 nlwb->lwb_buf = zio_buf_alloc(nlwb->lwb_sz);
848 nlwb->lwb_max_txg = txg;
849 nlwb->lwb_zio = NULL;
852 * Put new lwb at the end of the log chain
854 mutex_enter(&zilog->zl_lock);
855 list_insert_tail(&zilog->zl_lwb_list, nlwb);
856 mutex_exit(&zilog->zl_lock);
858 /* Record the block for later vdev flushing */
859 zil_add_block(zilog, &lwb->lwb_blk);
862 * kick off the write for the old log block
864 dprintf_bp(&lwb->lwb_blk, "lwb %p txg %llu: ", lwb, txg);
865 ASSERT(lwb->lwb_zio);
866 zio_nowait(lwb->lwb_zio);
872 zil_lwb_commit(zilog_t *zilog, itx_t *itx, lwb_t *lwb)
874 lr_t *lrc = &itx->itx_lr; /* common log record */
875 lr_write_t *lr = (lr_write_t *)lrc;
876 uint64_t txg = lrc->lrc_txg;
877 uint64_t reclen = lrc->lrc_reclen;
882 ASSERT(lwb->lwb_buf != NULL);
884 if (lrc->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY)
885 dlen = P2ROUNDUP_TYPED(
886 lr->lr_length, sizeof (uint64_t), uint64_t);
890 zilog->zl_cur_used += (reclen + dlen);
892 zil_lwb_write_init(zilog, lwb);
895 * If this record won't fit in the current log block, start a new one.
897 if (lwb->lwb_nused + reclen + dlen > ZIL_BLK_DATA_SZ(lwb)) {
898 lwb = zil_lwb_write_start(zilog, lwb);
901 zil_lwb_write_init(zilog, lwb);
902 ASSERT(lwb->lwb_nused == 0);
903 if (reclen + dlen > ZIL_BLK_DATA_SZ(lwb)) {
904 txg_wait_synced(zilog->zl_dmu_pool, txg);
910 * Update the lrc_seq, to be log record sequence number. See zil.h
911 * Then copy the record to the log buffer.
913 lrc->lrc_seq = ++zilog->zl_lr_seq; /* we are single threaded */
914 bcopy(lrc, lwb->lwb_buf + lwb->lwb_nused, reclen);
917 * If it's a write, fetch the data or get its blkptr as appropriate.
919 if (lrc->lrc_txtype == TX_WRITE) {
920 if (txg > spa_freeze_txg(zilog->zl_spa))
921 txg_wait_synced(zilog->zl_dmu_pool, txg);
922 if (itx->itx_wr_state != WR_COPIED) {
926 /* alignment is guaranteed */
927 lr = (lr_write_t *)(lwb->lwb_buf + lwb->lwb_nused);
929 ASSERT(itx->itx_wr_state == WR_NEED_COPY);
930 dbuf = lwb->lwb_buf + lwb->lwb_nused + reclen;
931 lr->lr_common.lrc_reclen += dlen;
933 ASSERT(itx->itx_wr_state == WR_INDIRECT);
936 error = zilog->zl_get_data(
937 itx->itx_private, lr, dbuf, lwb->lwb_zio);
939 ASSERT(error == ENOENT || error == EEXIST ||
946 lwb->lwb_nused += reclen + dlen;
947 lwb->lwb_max_txg = MAX(lwb->lwb_max_txg, txg);
948 ASSERT3U(lwb->lwb_nused, <=, ZIL_BLK_DATA_SZ(lwb));
949 ASSERT3U(P2PHASE(lwb->lwb_nused, sizeof (uint64_t)), ==, 0);
955 zil_itx_create(uint64_t txtype, size_t lrsize)
959 lrsize = P2ROUNDUP_TYPED(lrsize, sizeof (uint64_t), size_t);
961 itx = kmem_alloc(offsetof(itx_t, itx_lr) + lrsize, KM_SLEEP);
962 itx->itx_lr.lrc_txtype = txtype;
963 itx->itx_lr.lrc_reclen = lrsize;
964 itx->itx_sod = lrsize; /* if write & WR_NEED_COPY will be increased */
965 itx->itx_lr.lrc_seq = 0; /* defensive */
971 zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx)
975 ASSERT(itx->itx_lr.lrc_seq == 0);
977 mutex_enter(&zilog->zl_lock);
978 list_insert_tail(&zilog->zl_itx_list, itx);
979 zilog->zl_itx_list_sz += itx->itx_sod;
980 itx->itx_lr.lrc_txg = dmu_tx_get_txg(tx);
981 itx->itx_lr.lrc_seq = seq = ++zilog->zl_itx_seq;
982 mutex_exit(&zilog->zl_lock);
988 * Free up all in-memory intent log transactions that have now been synced.
991 zil_itx_clean(zilog_t *zilog)
993 uint64_t synced_txg = spa_last_synced_txg(zilog->zl_spa);
994 uint64_t freeze_txg = spa_freeze_txg(zilog->zl_spa);
998 list_create(&clean_list, sizeof (itx_t), offsetof(itx_t, itx_node));
1000 mutex_enter(&zilog->zl_lock);
1001 /* wait for a log writer to finish walking list */
1002 while (zilog->zl_writer) {
1003 cv_wait(&zilog->zl_cv_writer, &zilog->zl_lock);
1007 * Move the sync'd log transactions to a separate list so we can call
1008 * kmem_free without holding the zl_lock.
1010 * There is no need to set zl_writer as we don't drop zl_lock here
1012 while ((itx = list_head(&zilog->zl_itx_list)) != NULL &&
1013 itx->itx_lr.lrc_txg <= MIN(synced_txg, freeze_txg)) {
1014 list_remove(&zilog->zl_itx_list, itx);
1015 zilog->zl_itx_list_sz -= itx->itx_sod;
1016 list_insert_tail(&clean_list, itx);
1018 cv_broadcast(&zilog->zl_cv_writer);
1019 mutex_exit(&zilog->zl_lock);
1021 /* destroy sync'd log transactions */
1022 while ((itx = list_head(&clean_list)) != NULL) {
1023 list_remove(&clean_list, itx);
1024 kmem_free(itx, offsetof(itx_t, itx_lr)
1025 + itx->itx_lr.lrc_reclen);
1027 list_destroy(&clean_list);
1031 * If there are any in-memory intent log transactions which have now been
1032 * synced then start up a taskq to free them.
1035 zil_clean(zilog_t *zilog)
1039 mutex_enter(&zilog->zl_lock);
1040 itx = list_head(&zilog->zl_itx_list);
1041 if ((itx != NULL) &&
1042 (itx->itx_lr.lrc_txg <= spa_last_synced_txg(zilog->zl_spa))) {
1043 (void) taskq_dispatch(zilog->zl_clean_taskq,
1044 (task_func_t *)zil_itx_clean, zilog, TQ_SLEEP);
1046 mutex_exit(&zilog->zl_lock);
1050 zil_commit_writer(zilog_t *zilog, uint64_t seq, uint64_t foid)
1053 uint64_t commit_seq = 0;
1054 itx_t *itx, *itx_next = (itx_t *)-1;
1058 zilog->zl_writer = B_TRUE;
1059 ASSERT(zilog->zl_root_zio == NULL);
1060 spa = zilog->zl_spa;
1062 if (zilog->zl_suspend) {
1065 lwb = list_tail(&zilog->zl_lwb_list);
1068 * Return if there's nothing to flush before we
1069 * dirty the fs by calling zil_create()
1071 if (list_is_empty(&zilog->zl_itx_list)) {
1072 zilog->zl_writer = B_FALSE;
1075 mutex_exit(&zilog->zl_lock);
1077 mutex_enter(&zilog->zl_lock);
1078 lwb = list_tail(&zilog->zl_lwb_list);
1082 /* Loop through in-memory log transactions filling log blocks. */
1083 DTRACE_PROBE1(zil__cw1, zilog_t *, zilog);
1086 * Find the next itx to push:
1087 * Push all transactions related to specified foid and all
1088 * other transactions except TX_WRITE, TX_TRUNCATE,
1089 * TX_SETATTR and TX_ACL for all other files.
1091 if (itx_next != (itx_t *)-1)
1094 itx = list_head(&zilog->zl_itx_list);
1095 for (; itx != NULL; itx = list_next(&zilog->zl_itx_list, itx)) {
1096 if (foid == 0) /* push all foids? */
1098 if (itx->itx_sync) /* push all O_[D]SYNC */
1100 switch (itx->itx_lr.lrc_txtype) {
1105 /* lr_foid is same offset for these records */
1106 if (((lr_write_t *)&itx->itx_lr)->lr_foid
1108 continue; /* skip this record */
1116 if ((itx->itx_lr.lrc_seq > seq) &&
1117 ((lwb == NULL) || (lwb->lwb_nused == 0) ||
1118 (lwb->lwb_nused + itx->itx_sod > ZIL_BLK_DATA_SZ(lwb)))) {
1123 * Save the next pointer. Even though we soon drop
1124 * zl_lock all threads that may change the list
1125 * (another writer or zil_itx_clean) can't do so until
1126 * they have zl_writer.
1128 itx_next = list_next(&zilog->zl_itx_list, itx);
1129 list_remove(&zilog->zl_itx_list, itx);
1130 zilog->zl_itx_list_sz -= itx->itx_sod;
1131 mutex_exit(&zilog->zl_lock);
1132 txg = itx->itx_lr.lrc_txg;
1135 if (txg > spa_last_synced_txg(spa) ||
1136 txg > spa_freeze_txg(spa))
1137 lwb = zil_lwb_commit(zilog, itx, lwb);
1138 kmem_free(itx, offsetof(itx_t, itx_lr)
1139 + itx->itx_lr.lrc_reclen);
1140 mutex_enter(&zilog->zl_lock);
1142 DTRACE_PROBE1(zil__cw2, zilog_t *, zilog);
1143 /* determine commit sequence number */
1144 itx = list_head(&zilog->zl_itx_list);
1146 commit_seq = itx->itx_lr.lrc_seq;
1148 commit_seq = zilog->zl_itx_seq;
1149 mutex_exit(&zilog->zl_lock);
1151 /* write the last block out */
1152 if (lwb != NULL && lwb->lwb_zio != NULL)
1153 lwb = zil_lwb_write_start(zilog, lwb);
1155 zilog->zl_prev_used = zilog->zl_cur_used;
1156 zilog->zl_cur_used = 0;
1159 * Wait if necessary for the log blocks to be on stable storage.
1161 if (zilog->zl_root_zio) {
1162 DTRACE_PROBE1(zil__cw3, zilog_t *, zilog);
1163 (void) zio_wait(zilog->zl_root_zio);
1164 zilog->zl_root_zio = NULL;
1165 DTRACE_PROBE1(zil__cw4, zilog_t *, zilog);
1166 zil_flush_vdevs(zilog);
1169 if (zilog->zl_log_error || lwb == NULL) {
1170 zilog->zl_log_error = 0;
1171 txg_wait_synced(zilog->zl_dmu_pool, 0);
1174 mutex_enter(&zilog->zl_lock);
1175 zilog->zl_writer = B_FALSE;
1177 ASSERT3U(commit_seq, >=, zilog->zl_commit_seq);
1178 zilog->zl_commit_seq = commit_seq;
1182 * Push zfs transactions to stable storage up to the supplied sequence number.
1183 * If foid is 0 push out all transactions, otherwise push only those
1184 * for that file or might have been used to create that file.
1187 zil_commit(zilog_t *zilog, uint64_t seq, uint64_t foid)
1189 if (zilog == NULL || seq == 0)
1192 mutex_enter(&zilog->zl_lock);
1194 seq = MIN(seq, zilog->zl_itx_seq); /* cap seq at largest itx seq */
1196 while (zilog->zl_writer) {
1197 cv_wait(&zilog->zl_cv_writer, &zilog->zl_lock);
1198 if (seq < zilog->zl_commit_seq) {
1199 mutex_exit(&zilog->zl_lock);
1203 zil_commit_writer(zilog, seq, foid); /* drops zl_lock */
1204 /* wake up others waiting on the commit */
1205 cv_broadcast(&zilog->zl_cv_writer);
1206 mutex_exit(&zilog->zl_lock);
1210 * Called in syncing context to free committed log blocks and update log header.
1213 zil_sync(zilog_t *zilog, dmu_tx_t *tx)
1215 zil_header_t *zh = zil_header_in_syncing_context(zilog);
1216 uint64_t txg = dmu_tx_get_txg(tx);
1217 spa_t *spa = zilog->zl_spa;
1220 mutex_enter(&zilog->zl_lock);
1222 ASSERT(zilog->zl_stop_sync == 0);
1224 zh->zh_replay_seq = zilog->zl_replay_seq[txg & TXG_MASK];
1226 if (zilog->zl_destroy_txg == txg) {
1227 blkptr_t blk = zh->zh_log;
1229 ASSERT(list_head(&zilog->zl_lwb_list) == NULL);
1230 ASSERT(spa_sync_pass(spa) == 1);
1232 bzero(zh, sizeof (zil_header_t));
1233 bzero(zilog->zl_replay_seq, sizeof (zilog->zl_replay_seq));
1235 if (zilog->zl_keep_first) {
1237 * If this block was part of log chain that couldn't
1238 * be claimed because a device was missing during
1239 * zil_claim(), but that device later returns,
1240 * then this block could erroneously appear valid.
1241 * To guard against this, assign a new GUID to the new
1242 * log chain so it doesn't matter what blk points to.
1244 zil_init_log_chain(zilog, &blk);
1250 lwb = list_head(&zilog->zl_lwb_list);
1252 mutex_exit(&zilog->zl_lock);
1255 zh->zh_log = lwb->lwb_blk;
1256 if (lwb->lwb_buf != NULL || lwb->lwb_max_txg > txg)
1258 list_remove(&zilog->zl_lwb_list, lwb);
1259 zio_free_blk(spa, &lwb->lwb_blk, txg);
1260 kmem_cache_free(zil_lwb_cache, lwb);
1263 * If we don't have anything left in the lwb list then
1264 * we've had an allocation failure and we need to zero
1265 * out the zil_header blkptr so that we don't end
1266 * up freeing the same block twice.
1268 if (list_head(&zilog->zl_lwb_list) == NULL)
1269 BP_ZERO(&zh->zh_log);
1271 mutex_exit(&zilog->zl_lock);
1277 zil_lwb_cache = kmem_cache_create("zil_lwb_cache",
1278 sizeof (struct lwb), 0, NULL, NULL, NULL, NULL, NULL, 0);
1284 kmem_cache_destroy(zil_lwb_cache);
1288 zil_alloc(objset_t *os, zil_header_t *zh_phys)
1292 zilog = kmem_zalloc(sizeof (zilog_t), KM_SLEEP);
1294 zilog->zl_header = zh_phys;
1296 zilog->zl_spa = dmu_objset_spa(os);
1297 zilog->zl_dmu_pool = dmu_objset_pool(os);
1298 zilog->zl_destroy_txg = TXG_INITIAL - 1;
1300 mutex_init(&zilog->zl_lock, NULL, MUTEX_DEFAULT, NULL);
1302 list_create(&zilog->zl_itx_list, sizeof (itx_t),
1303 offsetof(itx_t, itx_node));
1305 list_create(&zilog->zl_lwb_list, sizeof (lwb_t),
1306 offsetof(lwb_t, lwb_node));
1308 mutex_init(&zilog->zl_vdev_lock, NULL, MUTEX_DEFAULT, NULL);
1310 avl_create(&zilog->zl_vdev_tree, zil_vdev_compare,
1311 sizeof (zil_vdev_node_t), offsetof(zil_vdev_node_t, zv_node));
1313 cv_init(&zilog->zl_cv_writer, NULL, CV_DEFAULT, NULL);
1314 cv_init(&zilog->zl_cv_suspend, NULL, CV_DEFAULT, NULL);
1320 zil_free(zilog_t *zilog)
1324 zilog->zl_stop_sync = 1;
1326 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) {
1327 list_remove(&zilog->zl_lwb_list, lwb);
1328 if (lwb->lwb_buf != NULL)
1329 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
1330 kmem_cache_free(zil_lwb_cache, lwb);
1332 list_destroy(&zilog->zl_lwb_list);
1334 avl_destroy(&zilog->zl_vdev_tree);
1335 mutex_destroy(&zilog->zl_vdev_lock);
1337 ASSERT(list_head(&zilog->zl_itx_list) == NULL);
1338 list_destroy(&zilog->zl_itx_list);
1339 mutex_destroy(&zilog->zl_lock);
1341 cv_destroy(&zilog->zl_cv_writer);
1342 cv_destroy(&zilog->zl_cv_suspend);
1344 kmem_free(zilog, sizeof (zilog_t));
1348 * return true if the initial log block is not valid
1351 zil_empty(zilog_t *zilog)
1353 const zil_header_t *zh = zilog->zl_header;
1354 arc_buf_t *abuf = NULL;
1356 if (BP_IS_HOLE(&zh->zh_log))
1359 if (zil_read_log_block(zilog, &zh->zh_log, &abuf) != 0)
1362 VERIFY(arc_buf_remove_ref(abuf, &abuf) == 1);
1367 * Open an intent log.
1370 zil_open(objset_t *os, zil_get_data_t *get_data)
1372 zilog_t *zilog = dmu_objset_zil(os);
1374 zilog->zl_get_data = get_data;
1375 zilog->zl_clean_taskq = taskq_create("zil_clean", 1, minclsyspri,
1376 2, 2, TASKQ_PREPOPULATE);
1382 * Close an intent log.
1385 zil_close(zilog_t *zilog)
1388 * If the log isn't already committed, mark the objset dirty
1389 * (so zil_sync() will be called) and wait for that txg to sync.
1391 if (!zil_is_committed(zilog)) {
1393 dmu_tx_t *tx = dmu_tx_create(zilog->zl_os);
1394 (void) dmu_tx_assign(tx, TXG_WAIT);
1395 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
1396 txg = dmu_tx_get_txg(tx);
1398 txg_wait_synced(zilog->zl_dmu_pool, txg);
1401 taskq_destroy(zilog->zl_clean_taskq);
1402 zilog->zl_clean_taskq = NULL;
1403 zilog->zl_get_data = NULL;
1405 zil_itx_clean(zilog);
1406 ASSERT(list_head(&zilog->zl_itx_list) == NULL);
1410 * Suspend an intent log. While in suspended mode, we still honor
1411 * synchronous semantics, but we rely on txg_wait_synced() to do it.
1412 * We suspend the log briefly when taking a snapshot so that the snapshot
1413 * contains all the data it's supposed to, and has an empty intent log.
1416 zil_suspend(zilog_t *zilog)
1418 const zil_header_t *zh = zilog->zl_header;
1420 mutex_enter(&zilog->zl_lock);
1421 if (zh->zh_claim_txg != 0) { /* unplayed log */
1422 mutex_exit(&zilog->zl_lock);
1425 if (zilog->zl_suspend++ != 0) {
1427 * Someone else already began a suspend.
1428 * Just wait for them to finish.
1430 while (zilog->zl_suspending)
1431 cv_wait(&zilog->zl_cv_suspend, &zilog->zl_lock);
1432 mutex_exit(&zilog->zl_lock);
1435 zilog->zl_suspending = B_TRUE;
1436 mutex_exit(&zilog->zl_lock);
1438 zil_commit(zilog, UINT64_MAX, 0);
1441 * Wait for any in-flight log writes to complete.
1443 mutex_enter(&zilog->zl_lock);
1444 while (zilog->zl_writer)
1445 cv_wait(&zilog->zl_cv_writer, &zilog->zl_lock);
1446 mutex_exit(&zilog->zl_lock);
1448 zil_destroy(zilog, B_FALSE);
1450 mutex_enter(&zilog->zl_lock);
1451 zilog->zl_suspending = B_FALSE;
1452 cv_broadcast(&zilog->zl_cv_suspend);
1453 mutex_exit(&zilog->zl_lock);
1459 zil_resume(zilog_t *zilog)
1461 mutex_enter(&zilog->zl_lock);
1462 ASSERT(zilog->zl_suspend != 0);
1463 zilog->zl_suspend--;
1464 mutex_exit(&zilog->zl_lock);
1467 typedef struct zil_replay_arg {
1469 zil_replay_func_t **zr_replay;
1470 zil_replay_cleaner_t *zr_replay_cleaner;
1473 boolean_t zr_byteswap;
1478 zil_replay_log_record(zilog_t *zilog, lr_t *lr, void *zra, uint64_t claim_txg)
1480 zil_replay_arg_t *zr = zra;
1481 const zil_header_t *zh = zilog->zl_header;
1482 uint64_t reclen = lr->lrc_reclen;
1483 uint64_t txtype = lr->lrc_txtype;
1485 int pass, error, sunk;
1487 if (zilog->zl_stop_replay)
1490 if (lr->lrc_txg < claim_txg) /* already committed */
1493 if (lr->lrc_seq <= zh->zh_replay_seq) /* already replayed */
1496 /* Strip case-insensitive bit, still present in log record */
1500 * Make a copy of the data so we can revise and extend it.
1502 bcopy(lr, zr->zr_lrbuf, reclen);
1505 * The log block containing this lr may have been byteswapped
1506 * so that we can easily examine common fields like lrc_txtype.
1507 * However, the log is a mix of different data types, and only the
1508 * replay vectors know how to byteswap their records. Therefore, if
1509 * the lr was byteswapped, undo it before invoking the replay vector.
1511 if (zr->zr_byteswap)
1512 byteswap_uint64_array(zr->zr_lrbuf, reclen);
1515 * If this is a TX_WRITE with a blkptr, suck in the data.
1517 if (txtype == TX_WRITE && reclen == sizeof (lr_write_t)) {
1518 lr_write_t *lrw = (lr_write_t *)lr;
1519 blkptr_t *wbp = &lrw->lr_blkptr;
1520 uint64_t wlen = lrw->lr_length;
1521 char *wbuf = zr->zr_lrbuf + reclen;
1523 if (BP_IS_HOLE(wbp)) { /* compressed to a hole */
1527 * A subsequent write may have overwritten this block,
1528 * in which case wbp may have been been freed and
1529 * reallocated, and our read of wbp may fail with a
1530 * checksum error. We can safely ignore this because
1531 * the later write will provide the correct data.
1535 zb.zb_objset = dmu_objset_id(zilog->zl_os);
1536 zb.zb_object = lrw->lr_foid;
1538 zb.zb_blkid = lrw->lr_offset / BP_GET_LSIZE(wbp);
1540 (void) zio_wait(zio_read(NULL, zilog->zl_spa,
1541 wbp, wbuf, BP_GET_LSIZE(wbp), NULL, NULL,
1542 ZIO_PRIORITY_SYNC_READ,
1543 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, &zb));
1544 (void) memmove(wbuf, wbuf + lrw->lr_blkoff, wlen);
1549 * We must now do two things atomically: replay this log record,
1550 * and update the log header to reflect the fact that we did so.
1551 * We use the DMU's ability to assign into a specific txg to do this.
1553 for (pass = 1, sunk = B_FALSE; /* CONSTANTCONDITION */; pass++) {
1554 uint64_t replay_txg;
1555 dmu_tx_t *replay_tx;
1557 replay_tx = dmu_tx_create(zr->zr_os);
1558 error = dmu_tx_assign(replay_tx, TXG_WAIT);
1560 dmu_tx_abort(replay_tx);
1564 replay_txg = dmu_tx_get_txg(replay_tx);
1566 if (txtype == 0 || txtype >= TX_MAX_TYPE) {
1570 * On the first pass, arrange for the replay vector
1571 * to fail its dmu_tx_assign(). That's the only way
1572 * to ensure that those code paths remain well tested.
1574 * Only byteswap (if needed) on the 1st pass.
1576 *zr->zr_txgp = replay_txg - (pass == 1);
1577 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lrbuf,
1578 zr->zr_byteswap && pass == 1);
1579 *zr->zr_txgp = TXG_NOWAIT;
1583 dsl_dataset_dirty(dmu_objset_ds(zr->zr_os), replay_tx);
1584 zilog->zl_replay_seq[replay_txg & TXG_MASK] =
1588 dmu_tx_commit(replay_tx);
1594 * The DMU's dnode layer doesn't see removes until the txg
1595 * commits, so a subsequent claim can spuriously fail with
1596 * EEXIST. So if we receive any error other than ERESTART
1597 * we try syncing out any removes then retrying the
1600 if (error != ERESTART && !sunk) {
1601 if (zr->zr_replay_cleaner)
1602 zr->zr_replay_cleaner(zr->zr_arg);
1603 txg_wait_synced(spa_get_dsl(zilog->zl_spa), 0);
1605 continue; /* retry */
1608 if (error != ERESTART)
1612 txg_wait_open(spa_get_dsl(zilog->zl_spa),
1615 dprintf("pass %d, retrying\n", pass);
1618 ASSERT(error && error != ERESTART);
1619 name = kmem_alloc(MAXNAMELEN, KM_SLEEP);
1620 dmu_objset_name(zr->zr_os, name);
1621 cmn_err(CE_WARN, "ZFS replay transaction error %d, "
1622 "dataset %s, seq 0x%llx, txtype %llu %s\n",
1623 error, name, (u_longlong_t)lr->lrc_seq, (u_longlong_t)txtype,
1624 (lr->lrc_txtype & TX_CI) ? "CI" : "");
1625 zilog->zl_stop_replay = 1;
1626 kmem_free(name, MAXNAMELEN);
1631 zil_incr_blks(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg)
1633 zilog->zl_replay_blks++;
1637 * If this dataset has a non-empty intent log, replay it and destroy it.
1640 zil_replay(objset_t *os, void *arg, uint64_t *txgp,
1641 zil_replay_func_t *replay_func[TX_MAX_TYPE],
1642 zil_replay_cleaner_t *replay_cleaner)
1644 zilog_t *zilog = dmu_objset_zil(os);
1645 const zil_header_t *zh = zilog->zl_header;
1646 zil_replay_arg_t zr;
1648 if (zil_empty(zilog)) {
1649 zil_destroy(zilog, B_TRUE);
1652 //printf("ZFS: Replaying ZIL on %s...\n", os->os->os_spa->spa_name);
1655 zr.zr_replay = replay_func;
1656 zr.zr_replay_cleaner = replay_cleaner;
1659 zr.zr_byteswap = BP_SHOULD_BYTESWAP(&zh->zh_log);
1660 zr.zr_lrbuf = kmem_alloc(2 * SPA_MAXBLOCKSIZE, KM_SLEEP);
1663 * Wait for in-progress removes to sync before starting replay.
1665 txg_wait_synced(zilog->zl_dmu_pool, 0);
1667 zilog->zl_stop_replay = 0;
1668 zilog->zl_replay_time = LBOLT;
1669 ASSERT(zilog->zl_replay_blks == 0);
1670 (void) zil_parse(zilog, zil_incr_blks, zil_replay_log_record, &zr,
1672 kmem_free(zr.zr_lrbuf, 2 * SPA_MAXBLOCKSIZE);
1674 zil_destroy(zilog, B_FALSE);
1675 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg);
1676 //printf("ZFS: Replay of ZIL on %s finished.\n", os->os->os_spa->spa_name);
1680 * Report whether all transactions are committed
1683 zil_is_committed(zilog_t *zilog)
1688 mutex_enter(&zilog->zl_lock);
1689 while (zilog->zl_writer)
1690 cv_wait(&zilog->zl_cv_writer, &zilog->zl_lock);
1692 /* recent unpushed intent log transactions? */
1693 if (!list_is_empty(&zilog->zl_itx_list)) {
1698 /* intent log never used? */
1699 lwb = list_head(&zilog->zl_lwb_list);
1706 * more than 1 log buffer means zil_sync() hasn't yet freed
1707 * entries after a txg has committed
1709 if (list_next(&zilog->zl_lwb_list, lwb)) {
1714 ASSERT(zil_empty(zilog));
1717 cv_broadcast(&zilog->zl_cv_writer);
1718 mutex_exit(&zilog->zl_lock);