1 /*
2 * CDDL HEADER START
3 *
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.
7 *
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.
12 *
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]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2011, 2014 by Delphix. All rights reserved.
24 */
25
26 /* Portions Copyright 2010 Robert Milkowski */
27
28 #include <sys/zfs_context.h>
29 #include <sys/spa.h>
30 #include <sys/dmu.h>
31 #include <sys/zap.h>
32 #include <sys/arc.h>
33 #include <sys/stat.h>
34 #include <sys/resource.h>
35 #include <sys/zil.h>
36 #include <sys/zil_impl.h>
37 #include <sys/dsl_dataset.h>
38 #include <sys/vdev_impl.h>
39 #include <sys/dmu_tx.h>
40 #include <sys/dsl_pool.h>
41
42 /*
43 * The zfs intent log (ZIL) saves transaction records of system calls
44 * that change the file system in memory with enough information
45 * to be able to replay them. These are stored in memory until
46 * either the DMU transaction group (txg) commits them to the stable pool
47 * and they can be discarded, or they are flushed to the stable log
48 * (also in the pool) due to a fsync, O_DSYNC or other synchronous
49 * requirement. In the event of a panic or power fail then those log
50 * records (transactions) are replayed.
51 *
52 * There is one ZIL per file system. Its on-disk (pool) format consists
53 * of 3 parts:
54 *
55 * - ZIL header
56 * - ZIL blocks
57 * - ZIL records
58 *
59 * A log record holds a system call transaction. Log blocks can
60 * hold many log records and the blocks are chained together.
61 * Each ZIL block contains a block pointer (blkptr_t) to the next
62 * ZIL block in the chain. The ZIL header points to the first
63 * block in the chain. Note there is not a fixed place in the pool
64 * to hold blocks. They are dynamically allocated and freed as
65 * needed from the blocks available. Figure X shows the ZIL structure:
66 */
67
68 /*
69 * Disable intent logging replay. This global ZIL switch affects all pools.
70 */
71 int zil_replay_disable = 0;
72
73 /*
74 * Tunable parameter for debugging or performance analysis. Setting
75 * zfs_nocacheflush will cause corruption on power loss if a volatile
76 * out-of-order write cache is enabled.
77 */
78 boolean_t zfs_nocacheflush = B_FALSE;
79
80 static kmem_cache_t *zil_lwb_cache;
81
82 static void zil_async_to_sync(zilog_t *zilog, uint64_t foid);
83
84 #define LWB_EMPTY(lwb) ((BP_GET_LSIZE(&lwb->lwb_blk) - \
85 sizeof (zil_chain_t)) == (lwb->lwb_sz - lwb->lwb_nused))
86
87
88 /*
89 * ziltest is by and large an ugly hack, but very useful in
90 * checking replay without tedious work.
91 * When running ziltest we want to keep all itx's and so maintain
92 * a single list in the zl_itxg[] that uses a high txg: ZILTEST_TXG
93 * We subtract TXG_CONCURRENT_STATES to allow for common code.
94 */
95 #define ZILTEST_TXG (UINT64_MAX - TXG_CONCURRENT_STATES)
96
97 static int
98 zil_bp_compare(const void *x1, const void *x2)
99 {
100 const dva_t *dva1 = &((zil_bp_node_t *)x1)->zn_dva;
101 const dva_t *dva2 = &((zil_bp_node_t *)x2)->zn_dva;
102
103 if (DVA_GET_VDEV(dva1) < DVA_GET_VDEV(dva2))
104 return (-1);
105 if (DVA_GET_VDEV(dva1) > DVA_GET_VDEV(dva2))
106 return (1);
107
108 if (DVA_GET_OFFSET(dva1) < DVA_GET_OFFSET(dva2))
109 return (-1);
110 if (DVA_GET_OFFSET(dva1) > DVA_GET_OFFSET(dva2))
111 return (1);
112
113 return (0);
114 }
115
116 static void
117 zil_bp_tree_init(zilog_t *zilog)
118 {
119 avl_create(&zilog->zl_bp_tree, zil_bp_compare,
120 sizeof (zil_bp_node_t), offsetof(zil_bp_node_t, zn_node));
121 }
122
123 static void
124 zil_bp_tree_fini(zilog_t *zilog)
125 {
126 avl_tree_t *t = &zilog->zl_bp_tree;
127 zil_bp_node_t *zn;
128 void *cookie = NULL;
129
130 while ((zn = avl_destroy_nodes(t, &cookie)) != NULL)
131 kmem_free(zn, sizeof (zil_bp_node_t));
132
133 avl_destroy(t);
134 }
135
136 int
137 zil_bp_tree_add(zilog_t *zilog, const blkptr_t *bp)
138 {
139 avl_tree_t *t = &zilog->zl_bp_tree;
140 const dva_t *dva;
141 zil_bp_node_t *zn;
142 avl_index_t where;
143
144 if (BP_IS_EMBEDDED(bp))
145 return (0);
146
147 dva = BP_IDENTITY(bp);
148
149 if (avl_find(t, dva, &where) != NULL)
150 return (SET_ERROR(EEXIST));
151
152 zn = kmem_alloc(sizeof (zil_bp_node_t), KM_SLEEP);
153 zn->zn_dva = *dva;
154 avl_insert(t, zn, where);
155
156 return (0);
157 }
158
159 static zil_header_t *
160 zil_header_in_syncing_context(zilog_t *zilog)
161 {
162 return ((zil_header_t *)zilog->zl_header);
163 }
164
165 static void
166 zil_init_log_chain(zilog_t *zilog, blkptr_t *bp)
167 {
168 zio_cksum_t *zc = &bp->blk_cksum;
169
170 zc->zc_word[ZIL_ZC_GUID_0] = spa_get_random(-1ULL);
171 zc->zc_word[ZIL_ZC_GUID_1] = spa_get_random(-1ULL);
172 zc->zc_word[ZIL_ZC_OBJSET] = dmu_objset_id(zilog->zl_os);
173 zc->zc_word[ZIL_ZC_SEQ] = 1ULL;
174 }
175
176 /*
177 * Read a log block and make sure it's valid.
178 */
179 static int
180 zil_read_log_block(zilog_t *zilog, const blkptr_t *bp, blkptr_t *nbp, void *dst,
181 char **end)
182 {
183 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL;
184 arc_flags_t aflags = ARC_FLAG_WAIT;
185 arc_buf_t *abuf = NULL;
186 zbookmark_phys_t zb;
187 int error;
188
189 if (zilog->zl_header->zh_claim_txg == 0)
190 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB;
191
192 if (!(zilog->zl_header->zh_flags & ZIL_CLAIM_LR_SEQ_VALID))
193 zio_flags |= ZIO_FLAG_SPECULATIVE;
194
195 SET_BOOKMARK(&zb, bp->blk_cksum.zc_word[ZIL_ZC_OBJSET],
196 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]);
197
198 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf,
199 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb);
200
201 if (error == 0) {
202 zio_cksum_t cksum = bp->blk_cksum;
203
204 /*
205 * Validate the checksummed log block.
206 *
207 * Sequence numbers should be... sequential. The checksum
208 * verifier for the next block should be bp's checksum plus 1.
209 *
210 * Also check the log chain linkage and size used.
211 */
212 cksum.zc_word[ZIL_ZC_SEQ]++;
213
214 if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) {
215 zil_chain_t *zilc = abuf->b_data;
216 char *lr = (char *)(zilc + 1);
217 uint64_t len = zilc->zc_nused - sizeof (zil_chain_t);
218
219 if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum,
220 sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk)) {
221 error = SET_ERROR(ECKSUM);
222 } else {
223 ASSERT3U(len, <=, SPA_OLD_MAXBLOCKSIZE);
224 bcopy(lr, dst, len);
225 *end = (char *)dst + len;
226 *nbp = zilc->zc_next_blk;
227 }
228 } else {
229 char *lr = abuf->b_data;
230 uint64_t size = BP_GET_LSIZE(bp);
231 zil_chain_t *zilc = (zil_chain_t *)(lr + size) - 1;
232
233 if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum,
234 sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk) ||
235 (zilc->zc_nused > (size - sizeof (*zilc)))) {
236 error = SET_ERROR(ECKSUM);
237 } else {
238 ASSERT3U(zilc->zc_nused, <=,
239 SPA_OLD_MAXBLOCKSIZE);
240 bcopy(lr, dst, zilc->zc_nused);
241 *end = (char *)dst + zilc->zc_nused;
242 *nbp = zilc->zc_next_blk;
243 }
244 }
245
246 VERIFY(arc_buf_remove_ref(abuf, &abuf));
247 }
248
249 return (error);
250 }
251
252 /*
253 * Read a TX_WRITE log data block.
254 */
255 static int
256 zil_read_log_data(zilog_t *zilog, const lr_write_t *lr, void *wbuf)
257 {
258 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL;
259 const blkptr_t *bp = &lr->lr_blkptr;
260 arc_flags_t aflags = ARC_FLAG_WAIT;
261 arc_buf_t *abuf = NULL;
262 zbookmark_phys_t zb;
263 int error;
264
265 if (BP_IS_HOLE(bp)) {
266 if (wbuf != NULL)
267 bzero(wbuf, MAX(BP_GET_LSIZE(bp), lr->lr_length));
268 return (0);
269 }
270
271 if (zilog->zl_header->zh_claim_txg == 0)
272 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB;
273
274 SET_BOOKMARK(&zb, dmu_objset_id(zilog->zl_os), lr->lr_foid,
275 ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp));
276
277 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf,
278 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb);
279
280 if (error == 0) {
281 if (wbuf != NULL)
282 bcopy(abuf->b_data, wbuf, arc_buf_size(abuf));
283 (void) arc_buf_remove_ref(abuf, &abuf);
284 }
285
286 return (error);
287 }
288
289 /*
290 * Parse the intent log, and call parse_func for each valid record within.
291 */
292 int
293 zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func,
294 zil_parse_lr_func_t *parse_lr_func, void *arg, uint64_t txg)
295 {
296 const zil_header_t *zh = zilog->zl_header;
297 boolean_t claimed = !!zh->zh_claim_txg;
298 uint64_t claim_blk_seq = claimed ? zh->zh_claim_blk_seq : UINT64_MAX;
299 uint64_t claim_lr_seq = claimed ? zh->zh_claim_lr_seq : UINT64_MAX;
300 uint64_t max_blk_seq = 0;
301 uint64_t max_lr_seq = 0;
302 uint64_t blk_count = 0;
303 uint64_t lr_count = 0;
304 blkptr_t blk, next_blk;
305 char *lrbuf, *lrp;
306 int error = 0;
307
308 /*
309 * Old logs didn't record the maximum zh_claim_lr_seq.
310 */
311 if (!(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID))
312 claim_lr_seq = UINT64_MAX;
313
314 /*
315 * Starting at the block pointed to by zh_log we read the log chain.
316 * For each block in the chain we strongly check that block to
317 * ensure its validity. We stop when an invalid block is found.
318 * For each block pointer in the chain we call parse_blk_func().
319 * For each record in each valid block we call parse_lr_func().
320 * If the log has been claimed, stop if we encounter a sequence
321 * number greater than the highest claimed sequence number.
322 */
323 lrbuf = zio_buf_alloc(SPA_OLD_MAXBLOCKSIZE);
324 zil_bp_tree_init(zilog);
325
326 for (blk = zh->zh_log; !BP_IS_HOLE(&blk); blk = next_blk) {
327 uint64_t blk_seq = blk.blk_cksum.zc_word[ZIL_ZC_SEQ];
328 int reclen;
329 char *end;
330
331 if (blk_seq > claim_blk_seq)
332 break;
333 if ((error = parse_blk_func(zilog, &blk, arg, txg)) != 0)
334 break;
335 ASSERT3U(max_blk_seq, <, blk_seq);
336 max_blk_seq = blk_seq;
337 blk_count++;
338
339 if (max_lr_seq == claim_lr_seq && max_blk_seq == claim_blk_seq)
340 break;
341
342 error = zil_read_log_block(zilog, &blk, &next_blk, lrbuf, &end);
343 if (error != 0)
344 break;
345
346 for (lrp = lrbuf; lrp < end; lrp += reclen) {
347 lr_t *lr = (lr_t *)lrp;
348 reclen = lr->lrc_reclen;
349 ASSERT3U(reclen, >=, sizeof (lr_t));
350 if (lr->lrc_seq > claim_lr_seq)
351 goto done;
352 if ((error = parse_lr_func(zilog, lr, arg, txg)) != 0)
353 goto done;
354 ASSERT3U(max_lr_seq, <, lr->lrc_seq);
355 max_lr_seq = lr->lrc_seq;
356 lr_count++;
357 }
358 }
359 done:
360 zilog->zl_parse_error = error;
361 zilog->zl_parse_blk_seq = max_blk_seq;
362 zilog->zl_parse_lr_seq = max_lr_seq;
363 zilog->zl_parse_blk_count = blk_count;
364 zilog->zl_parse_lr_count = lr_count;
365
366 ASSERT(!claimed || !(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID) ||
367 (max_blk_seq == claim_blk_seq && max_lr_seq == claim_lr_seq));
368
369 zil_bp_tree_fini(zilog);
370 zio_buf_free(lrbuf, SPA_OLD_MAXBLOCKSIZE);
371
372 return (error);
373 }
374
375 static int
376 zil_claim_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t first_txg)
377 {
378 /*
379 * Claim log block if not already committed and not already claimed.
380 * If tx == NULL, just verify that the block is claimable.
381 */
382 if (BP_IS_HOLE(bp) || bp->blk_birth < first_txg ||
383 zil_bp_tree_add(zilog, bp) != 0)
384 return (0);
385
386 return (zio_wait(zio_claim(NULL, zilog->zl_spa,
387 tx == NULL ? 0 : first_txg, bp, spa_claim_notify, NULL,
388 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB)));
389 }
390
391 static int
392 zil_claim_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t first_txg)
393 {
394 lr_write_t *lr = (lr_write_t *)lrc;
395 int error;
396
397 if (lrc->lrc_txtype != TX_WRITE)
398 return (0);
399
400 /*
401 * If the block is not readable, don't claim it. This can happen
402 * in normal operation when a log block is written to disk before
403 * some of the dmu_sync() blocks it points to. In this case, the
404 * transaction cannot have been committed to anyone (we would have
405 * waited for all writes to be stable first), so it is semantically
406 * correct to declare this the end of the log.
407 */
408 if (lr->lr_blkptr.blk_birth >= first_txg &&
409 (error = zil_read_log_data(zilog, lr, NULL)) != 0)
410 return (error);
411 return (zil_claim_log_block(zilog, &lr->lr_blkptr, tx, first_txg));
412 }
413
414 /* ARGSUSED */
415 static int
416 zil_free_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t claim_txg)
417 {
418 zio_free_zil(zilog->zl_spa, dmu_tx_get_txg(tx), bp);
419
420 return (0);
421 }
422
423 static int
424 zil_free_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t claim_txg)
425 {
426 lr_write_t *lr = (lr_write_t *)lrc;
427 blkptr_t *bp = &lr->lr_blkptr;
428
429 /*
430 * If we previously claimed it, we need to free it.
431 */
432 if (claim_txg != 0 && lrc->lrc_txtype == TX_WRITE &&
433 bp->blk_birth >= claim_txg && zil_bp_tree_add(zilog, bp) == 0 &&
434 !BP_IS_HOLE(bp))
435 zio_free(zilog->zl_spa, dmu_tx_get_txg(tx), bp);
436
437 return (0);
438 }
439
440 static lwb_t *
441 zil_alloc_lwb(zilog_t *zilog, blkptr_t *bp, uint64_t txg)
442 {
443 lwb_t *lwb;
444
445 lwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP);
446 lwb->lwb_zilog = zilog;
447 lwb->lwb_blk = *bp;
448 lwb->lwb_buf = zio_buf_alloc(BP_GET_LSIZE(bp));
449 lwb->lwb_max_txg = txg;
450 lwb->lwb_zio = NULL;
451 lwb->lwb_tx = NULL;
452 if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) {
453 lwb->lwb_nused = sizeof (zil_chain_t);
454 lwb->lwb_sz = BP_GET_LSIZE(bp);
455 } else {
456 lwb->lwb_nused = 0;
457 lwb->lwb_sz = BP_GET_LSIZE(bp) - sizeof (zil_chain_t);
458 }
459
460 mutex_enter(&zilog->zl_lock);
461 list_insert_tail(&zilog->zl_lwb_list, lwb);
462 mutex_exit(&zilog->zl_lock);
463
464 return (lwb);
465 }
466
467 /*
468 * Called when we create in-memory log transactions so that we know
469 * to cleanup the itxs at the end of spa_sync().
470 */
471 void
472 zilog_dirty(zilog_t *zilog, uint64_t txg)
473 {
474 dsl_pool_t *dp = zilog->zl_dmu_pool;
475 dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os);
476
477 if (ds->ds_is_snapshot)
478 panic("dirtying snapshot!");
479
480 if (txg_list_add(&dp->dp_dirty_zilogs, zilog, txg)) {
481 /* up the hold count until we can be written out */
482 dmu_buf_add_ref(ds->ds_dbuf, zilog);
483 }
484 }
485
486 boolean_t
487 zilog_is_dirty(zilog_t *zilog)
488 {
489 dsl_pool_t *dp = zilog->zl_dmu_pool;
490
491 for (int t = 0; t < TXG_SIZE; t++) {
492 if (txg_list_member(&dp->dp_dirty_zilogs, zilog, t))
493 return (B_TRUE);
494 }
495 return (B_FALSE);
496 }
497
498 /*
499 * Create an on-disk intent log.
500 */
501 static lwb_t *
502 zil_create(zilog_t *zilog)
503 {
504 const zil_header_t *zh = zilog->zl_header;
505 lwb_t *lwb = NULL;
506 uint64_t txg = 0;
507 dmu_tx_t *tx = NULL;
508 blkptr_t blk;
509 int error = 0;
510
511 /*
512 * Wait for any previous destroy to complete.
513 */
514 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg);
515
516 ASSERT(zh->zh_claim_txg == 0);
517 ASSERT(zh->zh_replay_seq == 0);
518
519 blk = zh->zh_log;
520
521 /*
522 * Allocate an initial log block if:
523 * - there isn't one already
524 * - the existing block is the wrong endianess
525 */
526 if (BP_IS_HOLE(&blk) || BP_SHOULD_BYTESWAP(&blk)) {
527 tx = dmu_tx_create(zilog->zl_os);
528 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0);
529 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
530 txg = dmu_tx_get_txg(tx);
531
532 if (!BP_IS_HOLE(&blk)) {
533 zio_free_zil(zilog->zl_spa, txg, &blk);
534 BP_ZERO(&blk);
535 }
536
537 error = zio_alloc_zil(zilog->zl_spa, txg, &blk, NULL,
538 ZIL_MIN_BLKSZ, zilog->zl_logbias == ZFS_LOGBIAS_LATENCY);
539
540 if (error == 0)
541 zil_init_log_chain(zilog, &blk);
542 }
543
544 /*
545 * Allocate a log write buffer (lwb) for the first log block.
546 */
547 if (error == 0)
548 lwb = zil_alloc_lwb(zilog, &blk, txg);
549
550 /*
551 * If we just allocated the first log block, commit our transaction
552 * and wait for zil_sync() to stuff the block poiner into zh_log.
553 * (zh is part of the MOS, so we cannot modify it in open context.)
554 */
555 if (tx != NULL) {
556 dmu_tx_commit(tx);
557 txg_wait_synced(zilog->zl_dmu_pool, txg);
558 }
559
560 ASSERT(bcmp(&blk, &zh->zh_log, sizeof (blk)) == 0);
561
562 return (lwb);
563 }
564
565 /*
566 * In one tx, free all log blocks and clear the log header.
567 * If keep_first is set, then we're replaying a log with no content.
568 * We want to keep the first block, however, so that the first
569 * synchronous transaction doesn't require a txg_wait_synced()
570 * in zil_create(). We don't need to txg_wait_synced() here either
571 * when keep_first is set, because both zil_create() and zil_destroy()
572 * will wait for any in-progress destroys to complete.
573 */
574 void
575 zil_destroy(zilog_t *zilog, boolean_t keep_first)
576 {
577 const zil_header_t *zh = zilog->zl_header;
578 lwb_t *lwb;
579 dmu_tx_t *tx;
580 uint64_t txg;
581
582 /*
583 * Wait for any previous destroy to complete.
584 */
585 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg);
586
587 zilog->zl_old_header = *zh; /* debugging aid */
588
589 if (BP_IS_HOLE(&zh->zh_log))
590 return;
591
592 tx = dmu_tx_create(zilog->zl_os);
593 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0);
594 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
595 txg = dmu_tx_get_txg(tx);
596
597 mutex_enter(&zilog->zl_lock);
598
599 ASSERT3U(zilog->zl_destroy_txg, <, txg);
600 zilog->zl_destroy_txg = txg;
601 zilog->zl_keep_first = keep_first;
602
603 if (!list_is_empty(&zilog->zl_lwb_list)) {
604 ASSERT(zh->zh_claim_txg == 0);
605 VERIFY(!keep_first);
606 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) {
607 list_remove(&zilog->zl_lwb_list, lwb);
608 if (lwb->lwb_buf != NULL)
609 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
610 zio_free_zil(zilog->zl_spa, txg, &lwb->lwb_blk);
611 kmem_cache_free(zil_lwb_cache, lwb);
612 }
613 } else if (!keep_first) {
614 zil_destroy_sync(zilog, tx);
615 }
616 mutex_exit(&zilog->zl_lock);
617
618 dmu_tx_commit(tx);
619 }
620
621 void
622 zil_destroy_sync(zilog_t *zilog, dmu_tx_t *tx)
623 {
624 ASSERT(list_is_empty(&zilog->zl_lwb_list));
625 (void) zil_parse(zilog, zil_free_log_block,
626 zil_free_log_record, tx, zilog->zl_header->zh_claim_txg);
627 }
628
629 int
630 zil_claim(dsl_pool_t *dp, dsl_dataset_t *ds, void *txarg)
631 {
632 dmu_tx_t *tx = txarg;
633 uint64_t first_txg = dmu_tx_get_txg(tx);
634 zilog_t *zilog;
635 zil_header_t *zh;
636 objset_t *os;
637 int error;
638
639 error = dmu_objset_own_obj(dp, ds->ds_object,
640 DMU_OST_ANY, B_FALSE, FTAG, &os);
641 if (error != 0) {
642 /*
643 * EBUSY indicates that the objset is inconsistent, in which
644 * case it can not have a ZIL.
645 */
646 if (error != EBUSY) {
647 cmn_err(CE_WARN, "can't open objset for %llu, error %u",
648 (unsigned long long)ds->ds_object, error);
649 }
650 return (0);
651 }
652
653 zilog = dmu_objset_zil(os);
654 zh = zil_header_in_syncing_context(zilog);
655
656 if (spa_get_log_state(zilog->zl_spa) == SPA_LOG_CLEAR) {
657 if (!BP_IS_HOLE(&zh->zh_log))
658 zio_free_zil(zilog->zl_spa, first_txg, &zh->zh_log);
659 BP_ZERO(&zh->zh_log);
660 dsl_dataset_dirty(dmu_objset_ds(os), tx);
661 dmu_objset_disown(os, FTAG);
662 return (0);
663 }
664
665 /*
666 * Claim all log blocks if we haven't already done so, and remember
667 * the highest claimed sequence number. This ensures that if we can
668 * read only part of the log now (e.g. due to a missing device),
669 * but we can read the entire log later, we will not try to replay
670 * or destroy beyond the last block we successfully claimed.
671 */
672 ASSERT3U(zh->zh_claim_txg, <=, first_txg);
673 if (zh->zh_claim_txg == 0 && !BP_IS_HOLE(&zh->zh_log)) {
674 (void) zil_parse(zilog, zil_claim_log_block,
675 zil_claim_log_record, tx, first_txg);
676 zh->zh_claim_txg = first_txg;
677 zh->zh_claim_blk_seq = zilog->zl_parse_blk_seq;
678 zh->zh_claim_lr_seq = zilog->zl_parse_lr_seq;
679 if (zilog->zl_parse_lr_count || zilog->zl_parse_blk_count > 1)
680 zh->zh_flags |= ZIL_REPLAY_NEEDED;
681 zh->zh_flags |= ZIL_CLAIM_LR_SEQ_VALID;
682 dsl_dataset_dirty(dmu_objset_ds(os), tx);
683 }
684
685 ASSERT3U(first_txg, ==, (spa_last_synced_txg(zilog->zl_spa) + 1));
686 dmu_objset_disown(os, FTAG);
687 return (0);
688 }
689
690 /*
691 * Check the log by walking the log chain.
692 * Checksum errors are ok as they indicate the end of the chain.
693 * Any other error (no device or read failure) returns an error.
694 */
695 /* ARGSUSED */
696 int
697 zil_check_log_chain(dsl_pool_t *dp, dsl_dataset_t *ds, void *tx)
698 {
699 zilog_t *zilog;
700 objset_t *os;
701 blkptr_t *bp;
702 int error;
703
704 ASSERT(tx == NULL);
705
706 error = dmu_objset_from_ds(ds, &os);
707 if (error != 0) {
708 cmn_err(CE_WARN, "can't open objset %llu, error %d",
709 (unsigned long long)ds->ds_object, error);
710 return (0);
711 }
712
713 zilog = dmu_objset_zil(os);
714 bp = (blkptr_t *)&zilog->zl_header->zh_log;
715
716 /*
717 * Check the first block and determine if it's on a log device
718 * which may have been removed or faulted prior to loading this
719 * pool. If so, there's no point in checking the rest of the log
720 * as its content should have already been synced to the pool.
721 */
722 if (!BP_IS_HOLE(bp)) {
723 vdev_t *vd;
724 boolean_t valid = B_TRUE;
725
726 spa_config_enter(os->os_spa, SCL_STATE, FTAG, RW_READER);
727 vd = vdev_lookup_top(os->os_spa, DVA_GET_VDEV(&bp->blk_dva[0]));
728 if (vd->vdev_islog && vdev_is_dead(vd))
729 valid = vdev_log_state_valid(vd);
730 spa_config_exit(os->os_spa, SCL_STATE, FTAG);
731
732 if (!valid)
733 return (0);
734 }
735
736 /*
737 * Because tx == NULL, zil_claim_log_block() will not actually claim
738 * any blocks, but just determine whether it is possible to do so.
739 * In addition to checking the log chain, zil_claim_log_block()
740 * will invoke zio_claim() with a done func of spa_claim_notify(),
741 * which will update spa_max_claim_txg. See spa_load() for details.
742 */
743 error = zil_parse(zilog, zil_claim_log_block, zil_claim_log_record, tx,
744 zilog->zl_header->zh_claim_txg ? -1ULL : spa_first_txg(os->os_spa));
745
746 return ((error == ECKSUM || error == ENOENT) ? 0 : error);
747 }
748
749 static int
750 zil_vdev_compare(const void *x1, const void *x2)
751 {
752 const uint64_t v1 = ((zil_vdev_node_t *)x1)->zv_vdev;
753 const uint64_t v2 = ((zil_vdev_node_t *)x2)->zv_vdev;
754
755 if (v1 < v2)
756 return (-1);
757 if (v1 > v2)
758 return (1);
759
760 return (0);
761 }
762
763 void
764 zil_add_block(zilog_t *zilog, const blkptr_t *bp)
765 {
766 avl_tree_t *t = &zilog->zl_vdev_tree;
767 avl_index_t where;
768 zil_vdev_node_t *zv, zvsearch;
769 int ndvas = BP_GET_NDVAS(bp);
770 int i;
771
772 if (zfs_nocacheflush)
773 return;
774
775 ASSERT(zilog->zl_writer);
776
777 /*
778 * Even though we're zl_writer, we still need a lock because the
779 * zl_get_data() callbacks may have dmu_sync() done callbacks
780 * that will run concurrently.
781 */
782 mutex_enter(&zilog->zl_vdev_lock);
783 for (i = 0; i < ndvas; i++) {
784 zvsearch.zv_vdev = DVA_GET_VDEV(&bp->blk_dva[i]);
785 if (avl_find(t, &zvsearch, &where) == NULL) {
786 zv = kmem_alloc(sizeof (*zv), KM_SLEEP);
787 zv->zv_vdev = zvsearch.zv_vdev;
788 avl_insert(t, zv, where);
789 }
790 }
791 mutex_exit(&zilog->zl_vdev_lock);
792 }
793
794 static void
795 zil_flush_vdevs(zilog_t *zilog)
796 {
797 spa_t *spa = zilog->zl_spa;
798 avl_tree_t *t = &zilog->zl_vdev_tree;
799 void *cookie = NULL;
800 zil_vdev_node_t *zv;
801 zio_t *zio;
802
803 ASSERT(zilog->zl_writer);
804
805 /*
806 * We don't need zl_vdev_lock here because we're the zl_writer,
807 * and all zl_get_data() callbacks are done.
808 */
809 if (avl_numnodes(t) == 0)
810 return;
811
812 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
813
814 zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
815
816 while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) {
817 vdev_t *vd = vdev_lookup_top(spa, zv->zv_vdev);
818 if (vd != NULL)
819 zio_flush(zio, vd);
820 kmem_free(zv, sizeof (*zv));
821 }
822
823 /*
824 * Wait for all the flushes to complete. Not all devices actually
825 * support the DKIOCFLUSHWRITECACHE ioctl, so it's OK if it fails.
826 */
827 (void) zio_wait(zio);
828
829 spa_config_exit(spa, SCL_STATE, FTAG);
830 }
831
832 /*
833 * Function called when a log block write completes
834 */
835 static void
836 zil_lwb_write_done(zio_t *zio)
837 {
838 lwb_t *lwb = zio->io_private;
839 zilog_t *zilog = lwb->lwb_zilog;
840 dmu_tx_t *tx = lwb->lwb_tx;
841
842 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF);
843 ASSERT(BP_GET_TYPE(zio->io_bp) == DMU_OT_INTENT_LOG);
844 ASSERT(BP_GET_LEVEL(zio->io_bp) == 0);
845 ASSERT(BP_GET_BYTEORDER(zio->io_bp) == ZFS_HOST_BYTEORDER);
846 ASSERT(!BP_IS_GANG(zio->io_bp));
847 ASSERT(!BP_IS_HOLE(zio->io_bp));
848 ASSERT(BP_GET_FILL(zio->io_bp) == 0);
849
850 /*
851 * Ensure the lwb buffer pointer is cleared before releasing
852 * the txg. If we have had an allocation failure and
853 * the txg is waiting to sync then we want want zil_sync()
854 * to remove the lwb so that it's not picked up as the next new
855 * one in zil_commit_writer(). zil_sync() will only remove
856 * the lwb if lwb_buf is null.
857 */
858 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
859 mutex_enter(&zilog->zl_lock);
860 lwb->lwb_buf = NULL;
861 lwb->lwb_tx = NULL;
862 mutex_exit(&zilog->zl_lock);
863
864 /*
865 * Now that we've written this log block, we have a stable pointer
866 * to the next block in the chain, so it's OK to let the txg in
867 * which we allocated the next block sync.
868 */
869 dmu_tx_commit(tx);
870 }
871
872 /*
873 * Initialize the io for a log block.
874 */
875 static void
876 zil_lwb_write_init(zilog_t *zilog, lwb_t *lwb)
877 {
878 zbookmark_phys_t zb;
879
880 SET_BOOKMARK(&zb, lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_OBJSET],
881 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL,
882 lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_SEQ]);
883
884 if (zilog->zl_root_zio == NULL) {
885 zilog->zl_root_zio = zio_root(zilog->zl_spa, NULL, NULL,
886 ZIO_FLAG_CANFAIL);
887 }
888 if (lwb->lwb_zio == NULL) {
889 lwb->lwb_zio = zio_rewrite(zilog->zl_root_zio, zilog->zl_spa,
890 0, &lwb->lwb_blk, lwb->lwb_buf, BP_GET_LSIZE(&lwb->lwb_blk),
891 zil_lwb_write_done, lwb, ZIO_PRIORITY_SYNC_WRITE,
892 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE, &zb);
893 }
894 }
895
896 /*
897 * Define a limited set of intent log block sizes.
898 *
899 * These must be a multiple of 4KB. Note only the amount used (again
900 * aligned to 4KB) actually gets written. However, we can't always just
901 * allocate SPA_OLD_MAXBLOCKSIZE as the slog space could be exhausted.
902 */
903 uint64_t zil_block_buckets[] = {
904 4096, /* non TX_WRITE */
905 8192+4096, /* data base */
906 32*1024 + 4096, /* NFS writes */
907 UINT64_MAX
908 };
909
910 /*
911 * Use the slog as long as the logbias is 'latency' and the current commit size
912 * is less than the limit or the total list size is less than 2X the limit.
913 * Limit checking is disabled by setting zil_slog_limit to UINT64_MAX.
914 */
915 uint64_t zil_slog_limit = 1024 * 1024;
916 #define USE_SLOG(zilog) (((zilog)->zl_logbias == ZFS_LOGBIAS_LATENCY) && \
917 (((zilog)->zl_cur_used < zil_slog_limit) || \
918 ((zilog)->zl_itx_list_sz < (zil_slog_limit << 1))))
919
920 /*
921 * Start a log block write and advance to the next log block.
922 * Calls are serialized.
923 */
924 static lwb_t *
925 zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb)
926 {
927 lwb_t *nlwb = NULL;
928 zil_chain_t *zilc;
929 spa_t *spa = zilog->zl_spa;
930 blkptr_t *bp;
931 dmu_tx_t *tx;
932 uint64_t txg;
933 uint64_t zil_blksz, wsz;
934 int i, error;
935
936 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) {
937 zilc = (zil_chain_t *)lwb->lwb_buf;
938 bp = &zilc->zc_next_blk;
939 } else {
940 zilc = (zil_chain_t *)(lwb->lwb_buf + lwb->lwb_sz);
941 bp = &zilc->zc_next_blk;
942 }
943
944 ASSERT(lwb->lwb_nused <= lwb->lwb_sz);
945
946 /*
947 * Allocate the next block and save its address in this block
948 * before writing it in order to establish the log chain.
949 * Note that if the allocation of nlwb synced before we wrote
950 * the block that points at it (lwb), we'd leak it if we crashed.
951 * Therefore, we don't do dmu_tx_commit() until zil_lwb_write_done().
952 * We dirty the dataset to ensure that zil_sync() will be called
953 * to clean up in the event of allocation failure or I/O failure.
954 */
955 tx = dmu_tx_create(zilog->zl_os);
956 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0);
957 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
958 txg = dmu_tx_get_txg(tx);
959
960 lwb->lwb_tx = tx;
961
962 /*
963 * Log blocks are pre-allocated. Here we select the size of the next
964 * block, based on size used in the last block.
965 * - first find the smallest bucket that will fit the block from a
966 * limited set of block sizes. This is because it's faster to write
967 * blocks allocated from the same metaslab as they are adjacent or
968 * close.
969 * - next find the maximum from the new suggested size and an array of
970 * previous sizes. This lessens a picket fence effect of wrongly
971 * guesssing the size if we have a stream of say 2k, 64k, 2k, 64k
972 * requests.
973 *
974 * Note we only write what is used, but we can't just allocate
975 * the maximum block size because we can exhaust the available
976 * pool log space.
977 */
978 zil_blksz = zilog->zl_cur_used + sizeof (zil_chain_t);
979 for (i = 0; zil_blksz > zil_block_buckets[i]; i++)
980 continue;
981 zil_blksz = zil_block_buckets[i];
982 if (zil_blksz == UINT64_MAX)
983 zil_blksz = SPA_OLD_MAXBLOCKSIZE;
984 zilog->zl_prev_blks[zilog->zl_prev_rotor] = zil_blksz;
985 for (i = 0; i < ZIL_PREV_BLKS; i++)
986 zil_blksz = MAX(zil_blksz, zilog->zl_prev_blks[i]);
987 zilog->zl_prev_rotor = (zilog->zl_prev_rotor + 1) & (ZIL_PREV_BLKS - 1);
988
989 BP_ZERO(bp);
990 /* pass the old blkptr in order to spread log blocks across devs */
991 error = zio_alloc_zil(spa, txg, bp, &lwb->lwb_blk, zil_blksz,
992 USE_SLOG(zilog));
993 if (error == 0) {
994 ASSERT3U(bp->blk_birth, ==, txg);
995 bp->blk_cksum = lwb->lwb_blk.blk_cksum;
996 bp->blk_cksum.zc_word[ZIL_ZC_SEQ]++;
997
998 /*
999 * Allocate a new log write buffer (lwb).
1000 */
1001 nlwb = zil_alloc_lwb(zilog, bp, txg);
1002
1003 /* Record the block for later vdev flushing */
1004 zil_add_block(zilog, &lwb->lwb_blk);
1005 }
1006
1007 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) {
1008 /* For Slim ZIL only write what is used. */
1009 wsz = P2ROUNDUP_TYPED(lwb->lwb_nused, ZIL_MIN_BLKSZ, uint64_t);
1010 ASSERT3U(wsz, <=, lwb->lwb_sz);
1011 zio_shrink(lwb->lwb_zio, wsz);
1012
1013 } else {
1014 wsz = lwb->lwb_sz;
1015 }
1016
1017 zilc->zc_pad = 0;
1018 zilc->zc_nused = lwb->lwb_nused;
1019 zilc->zc_eck.zec_cksum = lwb->lwb_blk.blk_cksum;
1020
1021 /*
1022 * clear unused data for security
1023 */
1024 bzero(lwb->lwb_buf + lwb->lwb_nused, wsz - lwb->lwb_nused);
1025
1026 zio_nowait(lwb->lwb_zio); /* Kick off the write for the old log block */
1027
1028 /*
1029 * If there was an allocation failure then nlwb will be null which
1030 * forces a txg_wait_synced().
1031 */
1032 return (nlwb);
1033 }
1034
1035 static lwb_t *
1036 zil_lwb_commit(zilog_t *zilog, itx_t *itx, lwb_t *lwb)
1037 {
1038 lr_t *lrc = &itx->itx_lr; /* common log record */
1039 lr_write_t *lrw = (lr_write_t *)lrc;
1040 char *lr_buf;
1041 uint64_t txg = lrc->lrc_txg;
1042 uint64_t reclen = lrc->lrc_reclen;
1043 uint64_t dlen = 0;
1044
1045 if (lwb == NULL)
1046 return (NULL);
1047
1048 ASSERT(lwb->lwb_buf != NULL);
1049 ASSERT(zilog_is_dirty(zilog) ||
1050 spa_freeze_txg(zilog->zl_spa) != UINT64_MAX);
1051
1052 if (lrc->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY)
1053 dlen = P2ROUNDUP_TYPED(
1054 lrw->lr_length, sizeof (uint64_t), uint64_t);
1055
1056 zilog->zl_cur_used += (reclen + dlen);
1057
1058 zil_lwb_write_init(zilog, lwb);
1059
1060 /*
1061 * If this record won't fit in the current log block, start a new one.
1062 */
1063 if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) {
1064 lwb = zil_lwb_write_start(zilog, lwb);
1065 if (lwb == NULL)
1066 return (NULL);
1067 zil_lwb_write_init(zilog, lwb);
1068 ASSERT(LWB_EMPTY(lwb));
1069 if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) {
1070 txg_wait_synced(zilog->zl_dmu_pool, txg);
1071 return (lwb);
1072 }
1073 }
1074
1075 lr_buf = lwb->lwb_buf + lwb->lwb_nused;
1076 bcopy(lrc, lr_buf, reclen);
1077 lrc = (lr_t *)lr_buf;
1078 lrw = (lr_write_t *)lrc;
1079
1080 /*
1081 * If it's a write, fetch the data or get its blkptr as appropriate.
1082 */
1083 if (lrc->lrc_txtype == TX_WRITE) {
1084 if (txg > spa_freeze_txg(zilog->zl_spa))
1085 txg_wait_synced(zilog->zl_dmu_pool, txg);
1086 if (itx->itx_wr_state != WR_COPIED) {
1087 char *dbuf;
1088 int error;
1089
1090 if (dlen) {
1091 ASSERT(itx->itx_wr_state == WR_NEED_COPY);
1092 dbuf = lr_buf + reclen;
1093 lrw->lr_common.lrc_reclen += dlen;
1094 } else {
1095 ASSERT(itx->itx_wr_state == WR_INDIRECT);
1096 dbuf = NULL;
1097 }
1098 error = zilog->zl_get_data(
1099 itx->itx_private, lrw, dbuf, lwb->lwb_zio);
1100 if (error == EIO) {
1101 txg_wait_synced(zilog->zl_dmu_pool, txg);
1102 return (lwb);
1103 }
1104 if (error != 0) {
1105 ASSERT(error == ENOENT || error == EEXIST ||
1106 error == EALREADY);
1107 return (lwb);
1108 }
1109 }
1110 }
1111
1112 /*
1113 * We're actually making an entry, so update lrc_seq to be the
1114 * log record sequence number. Note that this is generally not
1115 * equal to the itx sequence number because not all transactions
1116 * are synchronous, and sometimes spa_sync() gets there first.
1117 */
1118 lrc->lrc_seq = ++zilog->zl_lr_seq; /* we are single threaded */
1119 lwb->lwb_nused += reclen + dlen;
1120 lwb->lwb_max_txg = MAX(lwb->lwb_max_txg, txg);
1121 ASSERT3U(lwb->lwb_nused, <=, lwb->lwb_sz);
1122 ASSERT0(P2PHASE(lwb->lwb_nused, sizeof (uint64_t)));
1123
1124 return (lwb);
1125 }
1126
1127 itx_t *
1128 zil_itx_create(uint64_t txtype, size_t lrsize)
1129 {
1130 itx_t *itx;
1131
1132 lrsize = P2ROUNDUP_TYPED(lrsize, sizeof (uint64_t), size_t);
1133
1134 itx = kmem_alloc(offsetof(itx_t, itx_lr) + lrsize, KM_SLEEP);
1135 itx->itx_lr.lrc_txtype = txtype;
1136 itx->itx_lr.lrc_reclen = lrsize;
1137 itx->itx_sod = lrsize; /* if write & WR_NEED_COPY will be increased */
1138 itx->itx_lr.lrc_seq = 0; /* defensive */
1139 itx->itx_sync = B_TRUE; /* default is synchronous */
1140
1141 return (itx);
1142 }
1143
1144 void
1145 zil_itx_destroy(itx_t *itx)
1146 {
1147 kmem_free(itx, offsetof(itx_t, itx_lr) + itx->itx_lr.lrc_reclen);
1148 }
1149
1150 /*
1151 * Free up the sync and async itxs. The itxs_t has already been detached
1152 * so no locks are needed.
1153 */
1154 static void
1155 zil_itxg_clean(itxs_t *itxs)
1156 {
1157 itx_t *itx;
1158 list_t *list;
1159 avl_tree_t *t;
1160 void *cookie;
1161 itx_async_node_t *ian;
1162
1163 list = &itxs->i_sync_list;
1164 while ((itx = list_head(list)) != NULL) {
1165 list_remove(list, itx);
1166 kmem_free(itx, offsetof(itx_t, itx_lr) +
1167 itx->itx_lr.lrc_reclen);
1168 }
1169
1170 cookie = NULL;
1171 t = &itxs->i_async_tree;
1172 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) {
1173 list = &ian->ia_list;
1174 while ((itx = list_head(list)) != NULL) {
1175 list_remove(list, itx);
1176 kmem_free(itx, offsetof(itx_t, itx_lr) +
1177 itx->itx_lr.lrc_reclen);
1178 }
1179 list_destroy(list);
1180 kmem_free(ian, sizeof (itx_async_node_t));
1181 }
1182 avl_destroy(t);
1183
1184 kmem_free(itxs, sizeof (itxs_t));
1185 }
1186
1187 static int
1188 zil_aitx_compare(const void *x1, const void *x2)
1189 {
1190 const uint64_t o1 = ((itx_async_node_t *)x1)->ia_foid;
1191 const uint64_t o2 = ((itx_async_node_t *)x2)->ia_foid;
1192
1193 if (o1 < o2)
1194 return (-1);
1195 if (o1 > o2)
1196 return (1);
1197
1198 return (0);
1199 }
1200
1201 /*
1202 * Remove all async itx with the given oid.
1203 */
1204 static void
1205 zil_remove_async(zilog_t *zilog, uint64_t oid)
1206 {
1207 uint64_t otxg, txg;
1208 itx_async_node_t *ian;
1209 avl_tree_t *t;
1210 avl_index_t where;
1211 list_t clean_list;
1212 itx_t *itx;
1213
1214 ASSERT(oid != 0);
1215 list_create(&clean_list, sizeof (itx_t), offsetof(itx_t, itx_node));
1216
1217 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */
1218 otxg = ZILTEST_TXG;
1219 else
1220 otxg = spa_last_synced_txg(zilog->zl_spa) + 1;
1221
1222 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) {
1223 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK];
1224
1225 mutex_enter(&itxg->itxg_lock);
1226 if (itxg->itxg_txg != txg) {
1227 mutex_exit(&itxg->itxg_lock);
1228 continue;
1229 }
1230
1231 /*
1232 * Locate the object node and append its list.
1233 */
1234 t = &itxg->itxg_itxs->i_async_tree;
1235 ian = avl_find(t, &oid, &where);
1236 if (ian != NULL)
1237 list_move_tail(&clean_list, &ian->ia_list);
1238 mutex_exit(&itxg->itxg_lock);
1239 }
1240 while ((itx = list_head(&clean_list)) != NULL) {
1241 list_remove(&clean_list, itx);
1242 kmem_free(itx, offsetof(itx_t, itx_lr) +
1243 itx->itx_lr.lrc_reclen);
1244 }
1245 list_destroy(&clean_list);
1246 }
1247
1248 void
1249 zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx)
1250 {
1251 uint64_t txg;
1252 itxg_t *itxg;
1253 itxs_t *itxs, *clean = NULL;
1254
1255 /*
1256 * Object ids can be re-instantiated in the next txg so
1257 * remove any async transactions to avoid future leaks.
1258 * This can happen if a fsync occurs on the re-instantiated
1259 * object for a WR_INDIRECT or WR_NEED_COPY write, which gets
1260 * the new file data and flushes a write record for the old object.
1261 */
1262 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_REMOVE)
1263 zil_remove_async(zilog, itx->itx_oid);
1264
1265 /*
1266 * Ensure the data of a renamed file is committed before the rename.
1267 */
1268 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_RENAME)
1269 zil_async_to_sync(zilog, itx->itx_oid);
1270
1271 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX)
1272 txg = ZILTEST_TXG;
1273 else
1274 txg = dmu_tx_get_txg(tx);
1275
1276 itxg = &zilog->zl_itxg[txg & TXG_MASK];
1277 mutex_enter(&itxg->itxg_lock);
1278 itxs = itxg->itxg_itxs;
1279 if (itxg->itxg_txg != txg) {
1280 if (itxs != NULL) {
1281 /*
1282 * The zil_clean callback hasn't got around to cleaning
1283 * this itxg. Save the itxs for release below.
1284 * This should be rare.
1285 */
1286 atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod);
1287 itxg->itxg_sod = 0;
1288 clean = itxg->itxg_itxs;
1289 }
1290 ASSERT(itxg->itxg_sod == 0);
1291 itxg->itxg_txg = txg;
1292 itxs = itxg->itxg_itxs = kmem_zalloc(sizeof (itxs_t), KM_SLEEP);
1293
1294 list_create(&itxs->i_sync_list, sizeof (itx_t),
1295 offsetof(itx_t, itx_node));
1296 avl_create(&itxs->i_async_tree, zil_aitx_compare,
1297 sizeof (itx_async_node_t),
1298 offsetof(itx_async_node_t, ia_node));
1299 }
1300 if (itx->itx_sync) {
1301 list_insert_tail(&itxs->i_sync_list, itx);
1302 atomic_add_64(&zilog->zl_itx_list_sz, itx->itx_sod);
1303 itxg->itxg_sod += itx->itx_sod;
1304 } else {
1305 avl_tree_t *t = &itxs->i_async_tree;
1306 uint64_t foid = ((lr_ooo_t *)&itx->itx_lr)->lr_foid;
1307 itx_async_node_t *ian;
1308 avl_index_t where;
1309
1310 ian = avl_find(t, &foid, &where);
1311 if (ian == NULL) {
1312 ian = kmem_alloc(sizeof (itx_async_node_t), KM_SLEEP);
1313 list_create(&ian->ia_list, sizeof (itx_t),
1314 offsetof(itx_t, itx_node));
1315 ian->ia_foid = foid;
1316 avl_insert(t, ian, where);
1317 }
1318 list_insert_tail(&ian->ia_list, itx);
1319 }
1320
1321 itx->itx_lr.lrc_txg = dmu_tx_get_txg(tx);
1322 zilog_dirty(zilog, txg);
1323 mutex_exit(&itxg->itxg_lock);
1324
1325 /* Release the old itxs now we've dropped the lock */
1326 if (clean != NULL)
1327 zil_itxg_clean(clean);
1328 }
1329
1330 /*
1331 * If there are any in-memory intent log transactions which have now been
1332 * synced then start up a taskq to free them. We should only do this after we
1333 * have written out the uberblocks (i.e. txg has been comitted) so that
1334 * don't inadvertently clean out in-memory log records that would be required
1335 * by zil_commit().
1336 */
1337 void
1338 zil_clean(zilog_t *zilog, uint64_t synced_txg)
1339 {
1340 itxg_t *itxg = &zilog->zl_itxg[synced_txg & TXG_MASK];
1341 itxs_t *clean_me;
1342
1343 mutex_enter(&itxg->itxg_lock);
1344 if (itxg->itxg_itxs == NULL || itxg->itxg_txg == ZILTEST_TXG) {
1345 mutex_exit(&itxg->itxg_lock);
1346 return;
1347 }
1348 ASSERT3U(itxg->itxg_txg, <=, synced_txg);
1349 ASSERT(itxg->itxg_txg != 0);
1350 ASSERT(zilog->zl_clean_taskq != NULL);
1351 atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod);
1352 itxg->itxg_sod = 0;
1353 clean_me = itxg->itxg_itxs;
1354 itxg->itxg_itxs = NULL;
1355 itxg->itxg_txg = 0;
1356 mutex_exit(&itxg->itxg_lock);
1357 /*
1358 * Preferably start a task queue to free up the old itxs but
1359 * if taskq_dispatch can't allocate resources to do that then
1360 * free it in-line. This should be rare. Note, using TQ_SLEEP
1361 * created a bad performance problem.
1362 */
1363 if (taskq_dispatch(zilog->zl_clean_taskq,
1364 (void (*)(void *))zil_itxg_clean, clean_me, TQ_NOSLEEP) == NULL)
1365 zil_itxg_clean(clean_me);
1366 }
1367
1368 /*
1369 * Get the list of itxs to commit into zl_itx_commit_list.
1370 */
1371 static void
1372 zil_get_commit_list(zilog_t *zilog)
1373 {
1374 uint64_t otxg, txg;
1375 list_t *commit_list = &zilog->zl_itx_commit_list;
1376 uint64_t push_sod = 0;
1377
1378 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */
1379 otxg = ZILTEST_TXG;
1380 else
1381 otxg = spa_last_synced_txg(zilog->zl_spa) + 1;
1382
1383 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) {
1384 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK];
1385
1386 mutex_enter(&itxg->itxg_lock);
1387 if (itxg->itxg_txg != txg) {
1388 mutex_exit(&itxg->itxg_lock);
1389 continue;
1390 }
1391
1392 list_move_tail(commit_list, &itxg->itxg_itxs->i_sync_list);
1393 push_sod += itxg->itxg_sod;
1394 itxg->itxg_sod = 0;
1395
1396 mutex_exit(&itxg->itxg_lock);
1397 }
1398 atomic_add_64(&zilog->zl_itx_list_sz, -push_sod);
1399 }
1400
1401 /*
1402 * Move the async itxs for a specified object to commit into sync lists.
1403 */
1404 static void
1405 zil_async_to_sync(zilog_t *zilog, uint64_t foid)
1406 {
1407 uint64_t otxg, txg;
1408 itx_async_node_t *ian;
1409 avl_tree_t *t;
1410 avl_index_t where;
1411
1412 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */
1413 otxg = ZILTEST_TXG;
1414 else
1415 otxg = spa_last_synced_txg(zilog->zl_spa) + 1;
1416
1417 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) {
1418 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK];
1419
1420 mutex_enter(&itxg->itxg_lock);
1421 if (itxg->itxg_txg != txg) {
1422 mutex_exit(&itxg->itxg_lock);
1423 continue;
1424 }
1425
1426 /*
1427 * If a foid is specified then find that node and append its
1428 * list. Otherwise walk the tree appending all the lists
1429 * to the sync list. We add to the end rather than the
1430 * beginning to ensure the create has happened.
1431 */
1432 t = &itxg->itxg_itxs->i_async_tree;
1433 if (foid != 0) {
1434 ian = avl_find(t, &foid, &where);
1435 if (ian != NULL) {
1436 list_move_tail(&itxg->itxg_itxs->i_sync_list,
1437 &ian->ia_list);
1438 }
1439 } else {
1440 void *cookie = NULL;
1441
1442 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) {
1443 list_move_tail(&itxg->itxg_itxs->i_sync_list,
1444 &ian->ia_list);
1445 list_destroy(&ian->ia_list);
1446 kmem_free(ian, sizeof (itx_async_node_t));
1447 }
1448 }
1449 mutex_exit(&itxg->itxg_lock);
1450 }
1451 }
1452
1453 static void
1454 zil_commit_writer(zilog_t *zilog)
1455 {
1456 uint64_t txg;
1457 itx_t *itx;
1458 lwb_t *lwb;
1459 spa_t *spa = zilog->zl_spa;
1460 int error = 0;
1461
1462 ASSERT(zilog->zl_root_zio == NULL);
1463
1464 mutex_exit(&zilog->zl_lock);
1465
1466 zil_get_commit_list(zilog);
1467
1468 /*
1469 * Return if there's nothing to commit before we dirty the fs by
1470 * calling zil_create().
1471 */
1472 if (list_head(&zilog->zl_itx_commit_list) == NULL) {
1473 mutex_enter(&zilog->zl_lock);
1474 return;
1475 }
1476
1477 if (zilog->zl_suspend) {
1478 lwb = NULL;
1479 } else {
1480 lwb = list_tail(&zilog->zl_lwb_list);
1481 if (lwb == NULL)
1482 lwb = zil_create(zilog);
1483 }
1484
1485 DTRACE_PROBE1(zil__cw1, zilog_t *, zilog);
1486 while (itx = list_head(&zilog->zl_itx_commit_list)) {
1487 txg = itx->itx_lr.lrc_txg;
1488 ASSERT(txg);
1489
1490 if (txg > spa_last_synced_txg(spa) || txg > spa_freeze_txg(spa))
1491 lwb = zil_lwb_commit(zilog, itx, lwb);
1492 list_remove(&zilog->zl_itx_commit_list, itx);
1493 kmem_free(itx, offsetof(itx_t, itx_lr)
1494 + itx->itx_lr.lrc_reclen);
1495 }
1496 DTRACE_PROBE1(zil__cw2, zilog_t *, zilog);
1497
1498 /* write the last block out */
1499 if (lwb != NULL && lwb->lwb_zio != NULL)
1500 lwb = zil_lwb_write_start(zilog, lwb);
1501
1502 zilog->zl_cur_used = 0;
1503
1504 /*
1505 * Wait if necessary for the log blocks to be on stable storage.
1506 */
1507 if (zilog->zl_root_zio) {
1508 error = zio_wait(zilog->zl_root_zio);
1509 zilog->zl_root_zio = NULL;
1510 zil_flush_vdevs(zilog);
1511 }
1512
1513 if (error || lwb == NULL)
1514 txg_wait_synced(zilog->zl_dmu_pool, 0);
1515
1516 mutex_enter(&zilog->zl_lock);
1517
1518 /*
1519 * Remember the highest committed log sequence number for ztest.
1520 * We only update this value when all the log writes succeeded,
1521 * because ztest wants to ASSERT that it got the whole log chain.
1522 */
1523 if (error == 0 && lwb != NULL)
1524 zilog->zl_commit_lr_seq = zilog->zl_lr_seq;
1525 }
1526
1527 /*
1528 * Commit zfs transactions to stable storage.
1529 * If foid is 0 push out all transactions, otherwise push only those
1530 * for that object or might reference that object.
1531 *
1532 * itxs are committed in batches. In a heavily stressed zil there will be
1533 * a commit writer thread who is writing out a bunch of itxs to the log
1534 * for a set of committing threads (cthreads) in the same batch as the writer.
1535 * Those cthreads are all waiting on the same cv for that batch.
1536 *
1537 * There will also be a different and growing batch of threads that are
1538 * waiting to commit (qthreads). When the committing batch completes
1539 * a transition occurs such that the cthreads exit and the qthreads become
1540 * cthreads. One of the new cthreads becomes the writer thread for the
1541 * batch. Any new threads arriving become new qthreads.
1542 *
1543 * Only 2 condition variables are needed and there's no transition
1544 * between the two cvs needed. They just flip-flop between qthreads
1545 * and cthreads.
1546 *
1547 * Using this scheme we can efficiently wakeup up only those threads
1548 * that have been committed.
1549 */
1550 void
1551 zil_commit(zilog_t *zilog, uint64_t foid)
1552 {
1553 uint64_t mybatch;
1554
1555 if (zilog->zl_sync == ZFS_SYNC_DISABLED)
1556 return;
1557
1558 /* move the async itxs for the foid to the sync queues */
1559 zil_async_to_sync(zilog, foid);
1560
1561 mutex_enter(&zilog->zl_lock);
1562 mybatch = zilog->zl_next_batch;
1563 while (zilog->zl_writer) {
1564 cv_wait(&zilog->zl_cv_batch[mybatch & 1], &zilog->zl_lock);
1565 if (mybatch <= zilog->zl_com_batch) {
1566 mutex_exit(&zilog->zl_lock);
1567 return;
1568 }
1569 }
1570
1571 zilog->zl_next_batch++;
1572 zilog->zl_writer = B_TRUE;
1573 zil_commit_writer(zilog);
1574 zilog->zl_com_batch = mybatch;
1575 zilog->zl_writer = B_FALSE;
1576 mutex_exit(&zilog->zl_lock);
1577
1578 /* wake up one thread to become the next writer */
1579 cv_signal(&zilog->zl_cv_batch[(mybatch+1) & 1]);
1580
1581 /* wake up all threads waiting for this batch to be committed */
1582 cv_broadcast(&zilog->zl_cv_batch[mybatch & 1]);
1583 }
1584
1585 /*
1586 * Called in syncing context to free committed log blocks and update log header.
1587 */
1588 void
1589 zil_sync(zilog_t *zilog, dmu_tx_t *tx)
1590 {
1591 zil_header_t *zh = zil_header_in_syncing_context(zilog);
1592 uint64_t txg = dmu_tx_get_txg(tx);
1593 spa_t *spa = zilog->zl_spa;
1594 uint64_t *replayed_seq = &zilog->zl_replayed_seq[txg & TXG_MASK];
1595 lwb_t *lwb;
1596
1597 /*
1598 * We don't zero out zl_destroy_txg, so make sure we don't try
1599 * to destroy it twice.
1600 */
1601 if (spa_sync_pass(spa) != 1)
1602 return;
1603
1604 mutex_enter(&zilog->zl_lock);
1605
1606 ASSERT(zilog->zl_stop_sync == 0);
1607
1608 if (*replayed_seq != 0) {
1609 ASSERT(zh->zh_replay_seq < *replayed_seq);
1610 zh->zh_replay_seq = *replayed_seq;
1611 *replayed_seq = 0;
1612 }
1613
1614 if (zilog->zl_destroy_txg == txg) {
1615 blkptr_t blk = zh->zh_log;
1616
1617 ASSERT(list_head(&zilog->zl_lwb_list) == NULL);
1618
1619 bzero(zh, sizeof (zil_header_t));
1620 bzero(zilog->zl_replayed_seq, sizeof (zilog->zl_replayed_seq));
1621
1622 if (zilog->zl_keep_first) {
1623 /*
1624 * If this block was part of log chain that couldn't
1625 * be claimed because a device was missing during
1626 * zil_claim(), but that device later returns,
1627 * then this block could erroneously appear valid.
1628 * To guard against this, assign a new GUID to the new
1629 * log chain so it doesn't matter what blk points to.
1630 */
1631 zil_init_log_chain(zilog, &blk);
1632 zh->zh_log = blk;
1633 }
1634 }
1635
1636 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) {
1637 zh->zh_log = lwb->lwb_blk;
1638 if (lwb->lwb_buf != NULL || lwb->lwb_max_txg > txg)
1639 break;
1640 list_remove(&zilog->zl_lwb_list, lwb);
1641 zio_free_zil(spa, txg, &lwb->lwb_blk);
1642 kmem_cache_free(zil_lwb_cache, lwb);
1643
1644 /*
1645 * If we don't have anything left in the lwb list then
1646 * we've had an allocation failure and we need to zero
1647 * out the zil_header blkptr so that we don't end
1648 * up freeing the same block twice.
1649 */
1650 if (list_head(&zilog->zl_lwb_list) == NULL)
1651 BP_ZERO(&zh->zh_log);
1652 }
1653 mutex_exit(&zilog->zl_lock);
1654 }
1655
1656 void
1657 zil_init(void)
1658 {
1659 zil_lwb_cache = kmem_cache_create("zil_lwb_cache",
1660 sizeof (struct lwb), 0, NULL, NULL, NULL, NULL, NULL, 0);
1661 }
1662
1663 void
1664 zil_fini(void)
1665 {
1666 kmem_cache_destroy(zil_lwb_cache);
1667 }
1668
1669 void
1670 zil_set_sync(zilog_t *zilog, uint64_t sync)
1671 {
1672 zilog->zl_sync = sync;
1673 }
1674
1675 void
1676 zil_set_logbias(zilog_t *zilog, uint64_t logbias)
1677 {
1678 zilog->zl_logbias = logbias;
1679 }
1680
1681 zilog_t *
1682 zil_alloc(objset_t *os, zil_header_t *zh_phys)
1683 {
1684 zilog_t *zilog;
1685
1686 zilog = kmem_zalloc(sizeof (zilog_t), KM_SLEEP);
1687
1688 zilog->zl_header = zh_phys;
1689 zilog->zl_os = os;
1690 zilog->zl_spa = dmu_objset_spa(os);
1691 zilog->zl_dmu_pool = dmu_objset_pool(os);
1692 zilog->zl_destroy_txg = TXG_INITIAL - 1;
1693 zilog->zl_logbias = dmu_objset_logbias(os);
1694 zilog->zl_sync = dmu_objset_syncprop(os);
1695 zilog->zl_next_batch = 1;
1696
1697 mutex_init(&zilog->zl_lock, NULL, MUTEX_DEFAULT, NULL);
1698
1699 for (int i = 0; i < TXG_SIZE; i++) {
1700 mutex_init(&zilog->zl_itxg[i].itxg_lock, NULL,
1701 MUTEX_DEFAULT, NULL);
1702 }
1703
1704 list_create(&zilog->zl_lwb_list, sizeof (lwb_t),
1705 offsetof(lwb_t, lwb_node));
1706
1707 list_create(&zilog->zl_itx_commit_list, sizeof (itx_t),
1708 offsetof(itx_t, itx_node));
1709
1710 mutex_init(&zilog->zl_vdev_lock, NULL, MUTEX_DEFAULT, NULL);
1711
1712 avl_create(&zilog->zl_vdev_tree, zil_vdev_compare,
1713 sizeof (zil_vdev_node_t), offsetof(zil_vdev_node_t, zv_node));
1714
1715 cv_init(&zilog->zl_cv_writer, NULL, CV_DEFAULT, NULL);
1716 cv_init(&zilog->zl_cv_suspend, NULL, CV_DEFAULT, NULL);
1717 cv_init(&zilog->zl_cv_batch[0], NULL, CV_DEFAULT, NULL);
1718 cv_init(&zilog->zl_cv_batch[1], NULL, CV_DEFAULT, NULL);
1719
1720 return (zilog);
1721 }
1722
1723 void
1724 zil_free(zilog_t *zilog)
1725 {
1726 zilog->zl_stop_sync = 1;
1727
1728 ASSERT0(zilog->zl_suspend);
1729 ASSERT0(zilog->zl_suspending);
1730
1731 ASSERT(list_is_empty(&zilog->zl_lwb_list));
1732 list_destroy(&zilog->zl_lwb_list);
1733
1734 avl_destroy(&zilog->zl_vdev_tree);
1735 mutex_destroy(&zilog->zl_vdev_lock);
1736
1737 ASSERT(list_is_empty(&zilog->zl_itx_commit_list));
1738 list_destroy(&zilog->zl_itx_commit_list);
1739
1740 for (int i = 0; i < TXG_SIZE; i++) {
1741 /*
1742 * It's possible for an itx to be generated that doesn't dirty
1743 * a txg (e.g. ztest TX_TRUNCATE). So there's no zil_clean()
1744 * callback to remove the entry. We remove those here.
1745 *
1746 * Also free up the ziltest itxs.
1747 */
1748 if (zilog->zl_itxg[i].itxg_itxs)
1749 zil_itxg_clean(zilog->zl_itxg[i].itxg_itxs);
1750 mutex_destroy(&zilog->zl_itxg[i].itxg_lock);
1751 }
1752
1753 mutex_destroy(&zilog->zl_lock);
1754
1755 cv_destroy(&zilog->zl_cv_writer);
1756 cv_destroy(&zilog->zl_cv_suspend);
1757 cv_destroy(&zilog->zl_cv_batch[0]);
1758 cv_destroy(&zilog->zl_cv_batch[1]);
1759
1760 kmem_free(zilog, sizeof (zilog_t));
1761 }
1762
1763 /*
1764 * Open an intent log.
1765 */
1766 zilog_t *
1767 zil_open(objset_t *os, zil_get_data_t *get_data)
1768 {
1769 zilog_t *zilog = dmu_objset_zil(os);
1770
1771 ASSERT(zilog->zl_clean_taskq == NULL);
1772 ASSERT(zilog->zl_get_data == NULL);
1773 ASSERT(list_is_empty(&zilog->zl_lwb_list));
1774
1775 zilog->zl_get_data = get_data;
1776 zilog->zl_clean_taskq = taskq_create("zil_clean", 1, minclsyspri,
1777 2, 2, TASKQ_PREPOPULATE);
1778
1779 return (zilog);
1780 }
1781
1782 /*
1783 * Close an intent log.
1784 */
1785 void
1786 zil_close(zilog_t *zilog)
1787 {
1788 lwb_t *lwb;
1789 uint64_t txg = 0;
1790
1791 zil_commit(zilog, 0); /* commit all itx */
1792
1793 /*
1794 * The lwb_max_txg for the stubby lwb will reflect the last activity
1795 * for the zil. After a txg_wait_synced() on the txg we know all the
1796 * callbacks have occurred that may clean the zil. Only then can we
1797 * destroy the zl_clean_taskq.
1798 */
1799 mutex_enter(&zilog->zl_lock);
1800 lwb = list_tail(&zilog->zl_lwb_list);
1801 if (lwb != NULL)
1802 txg = lwb->lwb_max_txg;
1803 mutex_exit(&zilog->zl_lock);
1804 if (txg)
1805 txg_wait_synced(zilog->zl_dmu_pool, txg);
1806 ASSERT(!zilog_is_dirty(zilog));
1807
1808 taskq_destroy(zilog->zl_clean_taskq);
1809 zilog->zl_clean_taskq = NULL;
1810 zilog->zl_get_data = NULL;
1811
1812 /*
1813 * We should have only one LWB left on the list; remove it now.
1814 */
1815 mutex_enter(&zilog->zl_lock);
1816 lwb = list_head(&zilog->zl_lwb_list);
1817 if (lwb != NULL) {
1818 ASSERT(lwb == list_tail(&zilog->zl_lwb_list));
1819 list_remove(&zilog->zl_lwb_list, lwb);
1820 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
1821 kmem_cache_free(zil_lwb_cache, lwb);
1822 }
1823 mutex_exit(&zilog->zl_lock);
1824 }
1825
1826 static char *suspend_tag = "zil suspending";
1827
1828 /*
1829 * Suspend an intent log. While in suspended mode, we still honor
1830 * synchronous semantics, but we rely on txg_wait_synced() to do it.
1831 * On old version pools, we suspend the log briefly when taking a
1832 * snapshot so that it will have an empty intent log.
1833 *
1834 * Long holds are not really intended to be used the way we do here --
1835 * held for such a short time. A concurrent caller of dsl_dataset_long_held()
1836 * could fail. Therefore we take pains to only put a long hold if it is
1837 * actually necessary. Fortunately, it will only be necessary if the
1838 * objset is currently mounted (or the ZVOL equivalent). In that case it
1839 * will already have a long hold, so we are not really making things any worse.
1840 *
1841 * Ideally, we would locate the existing long-holder (i.e. the zfsvfs_t or
1842 * zvol_state_t), and use their mechanism to prevent their hold from being
1843 * dropped (e.g. VFS_HOLD()). However, that would be even more pain for
1844 * very little gain.
1845 *
1846 * if cookiep == NULL, this does both the suspend & resume.
1847 * Otherwise, it returns with the dataset "long held", and the cookie
1848 * should be passed into zil_resume().
1849 */
1850 int
1851 zil_suspend(const char *osname, void **cookiep)
1852 {
1853 objset_t *os;
1854 zilog_t *zilog;
1855 const zil_header_t *zh;
1856 int error;
1857
1858 error = dmu_objset_hold(osname, suspend_tag, &os);
1859 if (error != 0)
1860 return (error);
1861 zilog = dmu_objset_zil(os);
1862
1863 mutex_enter(&zilog->zl_lock);
1864 zh = zilog->zl_header;
1865
1866 if (zh->zh_flags & ZIL_REPLAY_NEEDED) { /* unplayed log */
1867 mutex_exit(&zilog->zl_lock);
1868 dmu_objset_rele(os, suspend_tag);
1869 return (SET_ERROR(EBUSY));
1870 }
1871
1872 /*
1873 * Don't put a long hold in the cases where we can avoid it. This
1874 * is when there is no cookie so we are doing a suspend & resume
1875 * (i.e. called from zil_vdev_offline()), and there's nothing to do
1876 * for the suspend because it's already suspended, or there's no ZIL.
1877 */
1878 if (cookiep == NULL && !zilog->zl_suspending &&
1879 (zilog->zl_suspend > 0 || BP_IS_HOLE(&zh->zh_log))) {
1880 mutex_exit(&zilog->zl_lock);
1881 dmu_objset_rele(os, suspend_tag);
1882 return (0);
1883 }
1884
1885 dsl_dataset_long_hold(dmu_objset_ds(os), suspend_tag);
1886 dsl_pool_rele(dmu_objset_pool(os), suspend_tag);
1887
1888 zilog->zl_suspend++;
1889
1890 if (zilog->zl_suspend > 1) {
1891 /*
1892 * Someone else is already suspending it.
1893 * Just wait for them to finish.
1894 */
1895
1896 while (zilog->zl_suspending)
1897 cv_wait(&zilog->zl_cv_suspend, &zilog->zl_lock);
1898 mutex_exit(&zilog->zl_lock);
1899
1900 if (cookiep == NULL)
1901 zil_resume(os);
1902 else
1903 *cookiep = os;
1904 return (0);
1905 }
1906
1907 /*
1908 * If there is no pointer to an on-disk block, this ZIL must not
1909 * be active (e.g. filesystem not mounted), so there's nothing
1910 * to clean up.
1911 */
1912 if (BP_IS_HOLE(&zh->zh_log)) {
1913 ASSERT(cookiep != NULL); /* fast path already handled */
1914
1915 *cookiep = os;
1916 mutex_exit(&zilog->zl_lock);
1917 return (0);
1918 }
1919
1920 zilog->zl_suspending = B_TRUE;
1921 mutex_exit(&zilog->zl_lock);
1922
1923 zil_commit(zilog, 0);
1924
1925 zil_destroy(zilog, B_FALSE);
1926
1927 mutex_enter(&zilog->zl_lock);
1928 zilog->zl_suspending = B_FALSE;
1929 cv_broadcast(&zilog->zl_cv_suspend);
1930 mutex_exit(&zilog->zl_lock);
1931
1932 if (cookiep == NULL)
1933 zil_resume(os);
1934 else
1935 *cookiep = os;
1936 return (0);
1937 }
1938
1939 void
1940 zil_resume(void *cookie)
1941 {
1942 objset_t *os = cookie;
1943 zilog_t *zilog = dmu_objset_zil(os);
1944
1945 mutex_enter(&zilog->zl_lock);
1946 ASSERT(zilog->zl_suspend != 0);
1947 zilog->zl_suspend--;
1948 mutex_exit(&zilog->zl_lock);
1949 dsl_dataset_long_rele(dmu_objset_ds(os), suspend_tag);
1950 dsl_dataset_rele(dmu_objset_ds(os), suspend_tag);
1951 }
1952
1953 typedef struct zil_replay_arg {
1954 zil_replay_func_t **zr_replay;
1955 void *zr_arg;
1956 boolean_t zr_byteswap;
1957 char *zr_lr;
1958 } zil_replay_arg_t;
1959
1960 static int
1961 zil_replay_error(zilog_t *zilog, lr_t *lr, int error)
1962 {
1963 char name[MAXNAMELEN];
1964
1965 zilog->zl_replaying_seq--; /* didn't actually replay this one */
1966
1967 dmu_objset_name(zilog->zl_os, name);
1968
1969 cmn_err(CE_WARN, "ZFS replay transaction error %d, "
1970 "dataset %s, seq 0x%llx, txtype %llu %s\n", error, name,
1971 (u_longlong_t)lr->lrc_seq,
1972 (u_longlong_t)(lr->lrc_txtype & ~TX_CI),
1973 (lr->lrc_txtype & TX_CI) ? "CI" : "");
1974
1975 return (error);
1976 }
1977
1978 static int
1979 zil_replay_log_record(zilog_t *zilog, lr_t *lr, void *zra, uint64_t claim_txg)
1980 {
1981 zil_replay_arg_t *zr = zra;
1982 const zil_header_t *zh = zilog->zl_header;
1983 uint64_t reclen = lr->lrc_reclen;
1984 uint64_t txtype = lr->lrc_txtype;
1985 int error = 0;
1986
1987 zilog->zl_replaying_seq = lr->lrc_seq;
1988
1989 if (lr->lrc_seq <= zh->zh_replay_seq) /* already replayed */
1990 return (0);
1991
1992 if (lr->lrc_txg < claim_txg) /* already committed */
1993 return (0);
1994
1995 /* Strip case-insensitive bit, still present in log record */
1996 txtype &= ~TX_CI;
1997
1998 if (txtype == 0 || txtype >= TX_MAX_TYPE)
1999 return (zil_replay_error(zilog, lr, EINVAL));
2000
2001 /*
2002 * If this record type can be logged out of order, the object
2003 * (lr_foid) may no longer exist. That's legitimate, not an error.
2004 */
2005 if (TX_OOO(txtype)) {
2006 error = dmu_object_info(zilog->zl_os,
2007 ((lr_ooo_t *)lr)->lr_foid, NULL);
2008 if (error == ENOENT || error == EEXIST)
2009 return (0);
2010 }
2011
2012 /*
2013 * Make a copy of the data so we can revise and extend it.
2014 */
2015 bcopy(lr, zr->zr_lr, reclen);
2016
2017 /*
2018 * If this is a TX_WRITE with a blkptr, suck in the data.
2019 */
2020 if (txtype == TX_WRITE && reclen == sizeof (lr_write_t)) {
2021 error = zil_read_log_data(zilog, (lr_write_t *)lr,
2022 zr->zr_lr + reclen);
2023 if (error != 0)
2024 return (zil_replay_error(zilog, lr, error));
2025 }
2026
2027 /*
2028 * The log block containing this lr may have been byteswapped
2029 * so that we can easily examine common fields like lrc_txtype.
2030 * However, the log is a mix of different record types, and only the
2031 * replay vectors know how to byteswap their records. Therefore, if
2032 * the lr was byteswapped, undo it before invoking the replay vector.
2033 */
2034 if (zr->zr_byteswap)
2035 byteswap_uint64_array(zr->zr_lr, reclen);
2036
2037 /*
2038 * We must now do two things atomically: replay this log record,
2039 * and update the log header sequence number to reflect the fact that
2040 * we did so. At the end of each replay function the sequence number
2041 * is updated if we are in replay mode.
2042 */
2043 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, zr->zr_byteswap);
2044 if (error != 0) {
2045 /*
2046 * The DMU's dnode layer doesn't see removes until the txg
2047 * commits, so a subsequent claim can spuriously fail with
2048 * EEXIST. So if we receive any error we try syncing out
2049 * any removes then retry the transaction. Note that we
2050 * specify B_FALSE for byteswap now, so we don't do it twice.
2051 */
2052 txg_wait_synced(spa_get_dsl(zilog->zl_spa), 0);
2053 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, B_FALSE);
2054 if (error != 0)
2055 return (zil_replay_error(zilog, lr, error));
2056 }
2057 return (0);
2058 }
2059
2060 /* ARGSUSED */
2061 static int
2062 zil_incr_blks(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg)
2063 {
2064 zilog->zl_replay_blks++;
2065
2066 return (0);
2067 }
2068
2069 /*
2070 * If this dataset has a non-empty intent log, replay it and destroy it.
2071 */
2072 void
2073 zil_replay(objset_t *os, void *arg, zil_replay_func_t *replay_func[TX_MAX_TYPE])
2074 {
2075 zilog_t *zilog = dmu_objset_zil(os);
2076 const zil_header_t *zh = zilog->zl_header;
2077 zil_replay_arg_t zr;
2078
2079 if ((zh->zh_flags & ZIL_REPLAY_NEEDED) == 0) {
2080 zil_destroy(zilog, B_TRUE);
2081 return;
2082 }
2083
2084 zr.zr_replay = replay_func;
2085 zr.zr_arg = arg;
2086 zr.zr_byteswap = BP_SHOULD_BYTESWAP(&zh->zh_log);
2087 zr.zr_lr = kmem_alloc(2 * SPA_MAXBLOCKSIZE, KM_SLEEP);
2088
2089 /*
2090 * Wait for in-progress removes to sync before starting replay.
2091 */
2092 txg_wait_synced(zilog->zl_dmu_pool, 0);
2093
2094 zilog->zl_replay = B_TRUE;
2095 zilog->zl_replay_time = ddi_get_lbolt();
2096 ASSERT(zilog->zl_replay_blks == 0);
2097 (void) zil_parse(zilog, zil_incr_blks, zil_replay_log_record, &zr,
2098 zh->zh_claim_txg);
2099 kmem_free(zr.zr_lr, 2 * SPA_MAXBLOCKSIZE);
2100
2101 zil_destroy(zilog, B_FALSE);
2102 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg);
2103 zilog->zl_replay = B_FALSE;
2104 }
2105
2106 boolean_t
2107 zil_replaying(zilog_t *zilog, dmu_tx_t *tx)
2108 {
2109 if (zilog->zl_sync == ZFS_SYNC_DISABLED)
2110 return (B_TRUE);
2111
2112 if (zilog->zl_replay) {
2113 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
2114 zilog->zl_replayed_seq[dmu_tx_get_txg(tx) & TXG_MASK] =
2115 zilog->zl_replaying_seq;
2116 return (B_TRUE);
2117 }
2118
2119 return (B_FALSE);
2120 }
2121
2122 /* ARGSUSED */
2123 int
2124 zil_vdev_offline(const char *osname, void *arg)
2125 {
2126 int error;
2127
2128 error = zil_suspend(osname, NULL);
2129 if (error != 0)
2130 return (SET_ERROR(EEXIST));
2131 return (0);
2132 }