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(const char *osname, 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(osname, DMU_OST_ANY, B_FALSE, FTAG, &os);
640 if (error != 0) {
641 /*
642 * EBUSY indicates that the objset is inconsistent, in which
643 * case it can not have a ZIL.
644 */
645 if (error != EBUSY) {
646 cmn_err(CE_WARN, "can't open objset for %s, error %u",
647 osname, error);
648 }
649 return (0);
650 }
651
652 zilog = dmu_objset_zil(os);
653 zh = zil_header_in_syncing_context(zilog);
654
655 if (spa_get_log_state(zilog->zl_spa) == SPA_LOG_CLEAR) {
656 if (!BP_IS_HOLE(&zh->zh_log))
657 zio_free_zil(zilog->zl_spa, first_txg, &zh->zh_log);
658 BP_ZERO(&zh->zh_log);
659 dsl_dataset_dirty(dmu_objset_ds(os), tx);
660 dmu_objset_disown(os, FTAG);
661 return (0);
662 }
663
664 /*
665 * Claim all log blocks if we haven't already done so, and remember
666 * the highest claimed sequence number. This ensures that if we can
667 * read only part of the log now (e.g. due to a missing device),
668 * but we can read the entire log later, we will not try to replay
669 * or destroy beyond the last block we successfully claimed.
670 */
671 ASSERT3U(zh->zh_claim_txg, <=, first_txg);
672 if (zh->zh_claim_txg == 0 && !BP_IS_HOLE(&zh->zh_log)) {
673 (void) zil_parse(zilog, zil_claim_log_block,
674 zil_claim_log_record, tx, first_txg);
675 zh->zh_claim_txg = first_txg;
676 zh->zh_claim_blk_seq = zilog->zl_parse_blk_seq;
677 zh->zh_claim_lr_seq = zilog->zl_parse_lr_seq;
678 if (zilog->zl_parse_lr_count || zilog->zl_parse_blk_count > 1)
679 zh->zh_flags |= ZIL_REPLAY_NEEDED;
680 zh->zh_flags |= ZIL_CLAIM_LR_SEQ_VALID;
681 dsl_dataset_dirty(dmu_objset_ds(os), tx);
682 }
683
684 ASSERT3U(first_txg, ==, (spa_last_synced_txg(zilog->zl_spa) + 1));
685 dmu_objset_disown(os, FTAG);
686 return (0);
687 }
688
689 /*
690 * Check the log by walking the log chain.
691 * Checksum errors are ok as they indicate the end of the chain.
692 * Any other error (no device or read failure) returns an error.
693 */
694 int
695 zil_check_log_chain(const char *osname, void *tx)
696 {
697 zilog_t *zilog;
698 objset_t *os;
699 blkptr_t *bp;
700 int error;
701
702 ASSERT(tx == NULL);
703
704 error = dmu_objset_hold(osname, FTAG, &os);
705 if (error != 0) {
706 cmn_err(CE_WARN, "can't open objset for %s", osname);
707 return (0);
708 }
709
710 zilog = dmu_objset_zil(os);
711 bp = (blkptr_t *)&zilog->zl_header->zh_log;
712
713 /*
714 * Check the first block and determine if it's on a log device
715 * which may have been removed or faulted prior to loading this
716 * pool. If so, there's no point in checking the rest of the log
717 * as its content should have already been synced to the pool.
718 */
719 if (!BP_IS_HOLE(bp)) {
720 vdev_t *vd;
721 boolean_t valid = B_TRUE;
722
723 spa_config_enter(os->os_spa, SCL_STATE, FTAG, RW_READER);
724 vd = vdev_lookup_top(os->os_spa, DVA_GET_VDEV(&bp->blk_dva[0]));
725 if (vd->vdev_islog && vdev_is_dead(vd))
726 valid = vdev_log_state_valid(vd);
727 spa_config_exit(os->os_spa, SCL_STATE, FTAG);
728
729 if (!valid) {
730 dmu_objset_rele(os, FTAG);
731 return (0);
732 }
733 }
734
735 /*
736 * Because tx == NULL, zil_claim_log_block() will not actually claim
737 * any blocks, but just determine whether it is possible to do so.
738 * In addition to checking the log chain, zil_claim_log_block()
739 * will invoke zio_claim() with a done func of spa_claim_notify(),
740 * which will update spa_max_claim_txg. See spa_load() for details.
741 */
742 error = zil_parse(zilog, zil_claim_log_block, zil_claim_log_record, tx,
743 zilog->zl_header->zh_claim_txg ? -1ULL : spa_first_txg(os->os_spa));
744
745 dmu_objset_rele(os, FTAG);
746
747 return ((error == ECKSUM || error == ENOENT) ? 0 : error);
748 }
749
750 static int
751 zil_vdev_compare(const void *x1, const void *x2)
752 {
753 const uint64_t v1 = ((zil_vdev_node_t *)x1)->zv_vdev;
754 const uint64_t v2 = ((zil_vdev_node_t *)x2)->zv_vdev;
755
756 if (v1 < v2)
757 return (-1);
758 if (v1 > v2)
759 return (1);
760
761 return (0);
762 }
763
764 void
765 zil_add_block(zilog_t *zilog, const blkptr_t *bp)
766 {
767 avl_tree_t *t = &zilog->zl_vdev_tree;
768 avl_index_t where;
769 zil_vdev_node_t *zv, zvsearch;
770 int ndvas = BP_GET_NDVAS(bp);
771 int i;
772
773 if (zfs_nocacheflush)
774 return;
775
776 ASSERT(zilog->zl_writer);
777
778 /*
779 * Even though we're zl_writer, we still need a lock because the
780 * zl_get_data() callbacks may have dmu_sync() done callbacks
781 * that will run concurrently.
782 */
783 mutex_enter(&zilog->zl_vdev_lock);
784 for (i = 0; i < ndvas; i++) {
785 zvsearch.zv_vdev = DVA_GET_VDEV(&bp->blk_dva[i]);
786 if (avl_find(t, &zvsearch, &where) == NULL) {
787 zv = kmem_alloc(sizeof (*zv), KM_SLEEP);
788 zv->zv_vdev = zvsearch.zv_vdev;
789 avl_insert(t, zv, where);
790 }
791 }
792 mutex_exit(&zilog->zl_vdev_lock);
793 }
794
795 static void
796 zil_flush_vdevs(zilog_t *zilog)
797 {
798 spa_t *spa = zilog->zl_spa;
799 avl_tree_t *t = &zilog->zl_vdev_tree;
800 void *cookie = NULL;
801 zil_vdev_node_t *zv;
802 zio_t *zio;
803
804 ASSERT(zilog->zl_writer);
805
806 /*
807 * We don't need zl_vdev_lock here because we're the zl_writer,
808 * and all zl_get_data() callbacks are done.
809 */
810 if (avl_numnodes(t) == 0)
811 return;
812
813 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
814
815 zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
816
817 while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) {
818 vdev_t *vd = vdev_lookup_top(spa, zv->zv_vdev);
819 if (vd != NULL)
820 zio_flush(zio, vd);
821 kmem_free(zv, sizeof (*zv));
822 }
823
824 /*
825 * Wait for all the flushes to complete. Not all devices actually
826 * support the DKIOCFLUSHWRITECACHE ioctl, so it's OK if it fails.
827 */
828 (void) zio_wait(zio);
829
830 spa_config_exit(spa, SCL_STATE, FTAG);
831 }
832
833 /*
834 * Function called when a log block write completes
835 */
836 static void
837 zil_lwb_write_done(zio_t *zio)
838 {
839 lwb_t *lwb = zio->io_private;
840 zilog_t *zilog = lwb->lwb_zilog;
841 dmu_tx_t *tx = lwb->lwb_tx;
842
843 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF);
844 ASSERT(BP_GET_TYPE(zio->io_bp) == DMU_OT_INTENT_LOG);
845 ASSERT(BP_GET_LEVEL(zio->io_bp) == 0);
846 ASSERT(BP_GET_BYTEORDER(zio->io_bp) == ZFS_HOST_BYTEORDER);
847 ASSERT(!BP_IS_GANG(zio->io_bp));
848 ASSERT(!BP_IS_HOLE(zio->io_bp));
849 ASSERT(BP_GET_FILL(zio->io_bp) == 0);
850
851 /*
852 * Ensure the lwb buffer pointer is cleared before releasing
853 * the txg. If we have had an allocation failure and
854 * the txg is waiting to sync then we want want zil_sync()
855 * to remove the lwb so that it's not picked up as the next new
856 * one in zil_commit_writer(). zil_sync() will only remove
857 * the lwb if lwb_buf is null.
858 */
859 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
860 mutex_enter(&zilog->zl_lock);
861 lwb->lwb_buf = NULL;
862 lwb->lwb_tx = NULL;
863 mutex_exit(&zilog->zl_lock);
864
865 /*
866 * Now that we've written this log block, we have a stable pointer
867 * to the next block in the chain, so it's OK to let the txg in
868 * which we allocated the next block sync.
869 */
870 dmu_tx_commit(tx);
871 }
872
873 /*
874 * Initialize the io for a log block.
875 */
876 static void
877 zil_lwb_write_init(zilog_t *zilog, lwb_t *lwb)
878 {
879 zbookmark_phys_t zb;
880
881 SET_BOOKMARK(&zb, lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_OBJSET],
882 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL,
883 lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_SEQ]);
884
885 if (zilog->zl_root_zio == NULL) {
886 zilog->zl_root_zio = zio_root(zilog->zl_spa, NULL, NULL,
887 ZIO_FLAG_CANFAIL);
888 }
889 if (lwb->lwb_zio == NULL) {
890 lwb->lwb_zio = zio_rewrite(zilog->zl_root_zio, zilog->zl_spa,
891 0, &lwb->lwb_blk, lwb->lwb_buf, BP_GET_LSIZE(&lwb->lwb_blk),
892 zil_lwb_write_done, lwb, ZIO_PRIORITY_SYNC_WRITE,
893 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE, &zb);
894 }
895 }
896
897 /*
898 * Define a limited set of intent log block sizes.
899 *
900 * These must be a multiple of 4KB. Note only the amount used (again
901 * aligned to 4KB) actually gets written. However, we can't always just
902 * allocate SPA_OLD_MAXBLOCKSIZE as the slog space could be exhausted.
903 */
904 uint64_t zil_block_buckets[] = {
905 4096, /* non TX_WRITE */
906 8192+4096, /* data base */
907 32*1024 + 4096, /* NFS writes */
908 UINT64_MAX
909 };
910
911 /*
912 * Use the slog as long as the logbias is 'latency' and the current commit size
913 * is less than the limit or the total list size is less than 2X the limit.
914 * Limit checking is disabled by setting zil_slog_limit to UINT64_MAX.
915 */
916 uint64_t zil_slog_limit = 1024 * 1024;
917 #define USE_SLOG(zilog) (((zilog)->zl_logbias == ZFS_LOGBIAS_LATENCY) && \
918 (((zilog)->zl_cur_used < zil_slog_limit) || \
919 ((zilog)->zl_itx_list_sz < (zil_slog_limit << 1))))
920
921 /*
922 * Start a log block write and advance to the next log block.
923 * Calls are serialized.
924 */
925 static lwb_t *
926 zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb)
927 {
928 lwb_t *nlwb = NULL;
929 zil_chain_t *zilc;
930 spa_t *spa = zilog->zl_spa;
931 blkptr_t *bp;
932 dmu_tx_t *tx;
933 uint64_t txg;
934 uint64_t zil_blksz, wsz;
935 int i, error;
936
937 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) {
938 zilc = (zil_chain_t *)lwb->lwb_buf;
939 bp = &zilc->zc_next_blk;
940 } else {
941 zilc = (zil_chain_t *)(lwb->lwb_buf + lwb->lwb_sz);
942 bp = &zilc->zc_next_blk;
943 }
944
945 ASSERT(lwb->lwb_nused <= lwb->lwb_sz);
946
947 /*
948 * Allocate the next block and save its address in this block
949 * before writing it in order to establish the log chain.
950 * Note that if the allocation of nlwb synced before we wrote
951 * the block that points at it (lwb), we'd leak it if we crashed.
952 * Therefore, we don't do dmu_tx_commit() until zil_lwb_write_done().
953 * We dirty the dataset to ensure that zil_sync() will be called
954 * to clean up in the event of allocation failure or I/O failure.
955 */
956 tx = dmu_tx_create(zilog->zl_os);
957 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0);
958 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
959 txg = dmu_tx_get_txg(tx);
960
961 lwb->lwb_tx = tx;
962
963 /*
964 * Log blocks are pre-allocated. Here we select the size of the next
965 * block, based on size used in the last block.
966 * - first find the smallest bucket that will fit the block from a
967 * limited set of block sizes. This is because it's faster to write
968 * blocks allocated from the same metaslab as they are adjacent or
969 * close.
970 * - next find the maximum from the new suggested size and an array of
971 * previous sizes. This lessens a picket fence effect of wrongly
972 * guesssing the size if we have a stream of say 2k, 64k, 2k, 64k
973 * requests.
974 *
975 * Note we only write what is used, but we can't just allocate
976 * the maximum block size because we can exhaust the available
977 * pool log space.
978 */
979 zil_blksz = zilog->zl_cur_used + sizeof (zil_chain_t);
980 for (i = 0; zil_blksz > zil_block_buckets[i]; i++)
981 continue;
982 zil_blksz = zil_block_buckets[i];
983 if (zil_blksz == UINT64_MAX)
984 zil_blksz = SPA_OLD_MAXBLOCKSIZE;
985 zilog->zl_prev_blks[zilog->zl_prev_rotor] = zil_blksz;
986 for (i = 0; i < ZIL_PREV_BLKS; i++)
987 zil_blksz = MAX(zil_blksz, zilog->zl_prev_blks[i]);
988 zilog->zl_prev_rotor = (zilog->zl_prev_rotor + 1) & (ZIL_PREV_BLKS - 1);
989
990 BP_ZERO(bp);
991 /* pass the old blkptr in order to spread log blocks across devs */
992 error = zio_alloc_zil(spa, txg, bp, &lwb->lwb_blk, zil_blksz,
993 USE_SLOG(zilog));
994 if (error == 0) {
995 ASSERT3U(bp->blk_birth, ==, txg);
996 bp->blk_cksum = lwb->lwb_blk.blk_cksum;
997 bp->blk_cksum.zc_word[ZIL_ZC_SEQ]++;
998
999 /*
1000 * Allocate a new log write buffer (lwb).
1001 */
1002 nlwb = zil_alloc_lwb(zilog, bp, txg);
1003
1004 /* Record the block for later vdev flushing */
1005 zil_add_block(zilog, &lwb->lwb_blk);
1006 }
1007
1008 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) {
1009 /* For Slim ZIL only write what is used. */
1010 wsz = P2ROUNDUP_TYPED(lwb->lwb_nused, ZIL_MIN_BLKSZ, uint64_t);
1011 ASSERT3U(wsz, <=, lwb->lwb_sz);
1012 zio_shrink(lwb->lwb_zio, wsz);
1013
1014 } else {
1015 wsz = lwb->lwb_sz;
1016 }
1017
1018 zilc->zc_pad = 0;
1019 zilc->zc_nused = lwb->lwb_nused;
1020 zilc->zc_eck.zec_cksum = lwb->lwb_blk.blk_cksum;
1021
1022 /*
1023 * clear unused data for security
1024 */
1025 bzero(lwb->lwb_buf + lwb->lwb_nused, wsz - lwb->lwb_nused);
1026
1027 zio_nowait(lwb->lwb_zio); /* Kick off the write for the old log block */
1028
1029 /*
1030 * If there was an allocation failure then nlwb will be null which
1031 * forces a txg_wait_synced().
1032 */
1033 return (nlwb);
1034 }
1035
1036 static lwb_t *
1037 zil_lwb_commit(zilog_t *zilog, itx_t *itx, lwb_t *lwb)
1038 {
1039 lr_t *lrc = &itx->itx_lr; /* common log record */
1040 lr_write_t *lrw = (lr_write_t *)lrc;
1041 char *lr_buf;
1042 uint64_t txg = lrc->lrc_txg;
1043 uint64_t reclen = lrc->lrc_reclen;
1044 uint64_t dlen = 0;
1045
1046 if (lwb == NULL)
1047 return (NULL);
1048
1049 ASSERT(lwb->lwb_buf != NULL);
1050 ASSERT(zilog_is_dirty(zilog) ||
1051 spa_freeze_txg(zilog->zl_spa) != UINT64_MAX);
1052
1053 if (lrc->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY)
1054 dlen = P2ROUNDUP_TYPED(
1055 lrw->lr_length, sizeof (uint64_t), uint64_t);
1056
1057 zilog->zl_cur_used += (reclen + dlen);
1058
1059 zil_lwb_write_init(zilog, lwb);
1060
1061 /*
1062 * If this record won't fit in the current log block, start a new one.
1063 */
1064 if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) {
1065 lwb = zil_lwb_write_start(zilog, lwb);
1066 if (lwb == NULL)
1067 return (NULL);
1068 zil_lwb_write_init(zilog, lwb);
1069 ASSERT(LWB_EMPTY(lwb));
1070 if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) {
1071 txg_wait_synced(zilog->zl_dmu_pool, txg);
1072 return (lwb);
1073 }
1074 }
1075
1076 lr_buf = lwb->lwb_buf + lwb->lwb_nused;
1077 bcopy(lrc, lr_buf, reclen);
1078 lrc = (lr_t *)lr_buf;
1079 lrw = (lr_write_t *)lrc;
1080
1081 /*
1082 * If it's a write, fetch the data or get its blkptr as appropriate.
1083 */
1084 if (lrc->lrc_txtype == TX_WRITE) {
1085 if (txg > spa_freeze_txg(zilog->zl_spa))
1086 txg_wait_synced(zilog->zl_dmu_pool, txg);
1087 if (itx->itx_wr_state != WR_COPIED) {
1088 char *dbuf;
1089 int error;
1090
1091 if (dlen) {
1092 ASSERT(itx->itx_wr_state == WR_NEED_COPY);
1093 dbuf = lr_buf + reclen;
1094 lrw->lr_common.lrc_reclen += dlen;
1095 } else {
1096 ASSERT(itx->itx_wr_state == WR_INDIRECT);
1097 dbuf = NULL;
1098 }
1099 error = zilog->zl_get_data(
1100 itx->itx_private, lrw, dbuf, lwb->lwb_zio);
1101 if (error == EIO) {
1102 txg_wait_synced(zilog->zl_dmu_pool, txg);
1103 return (lwb);
1104 }
1105 if (error != 0) {
1106 ASSERT(error == ENOENT || error == EEXIST ||
1107 error == EALREADY);
1108 return (lwb);
1109 }
1110 }
1111 }
1112
1113 /*
1114 * We're actually making an entry, so update lrc_seq to be the
1115 * log record sequence number. Note that this is generally not
1116 * equal to the itx sequence number because not all transactions
1117 * are synchronous, and sometimes spa_sync() gets there first.
1118 */
1119 lrc->lrc_seq = ++zilog->zl_lr_seq; /* we are single threaded */
1120 lwb->lwb_nused += reclen + dlen;
1121 lwb->lwb_max_txg = MAX(lwb->lwb_max_txg, txg);
1122 ASSERT3U(lwb->lwb_nused, <=, lwb->lwb_sz);
1123 ASSERT0(P2PHASE(lwb->lwb_nused, sizeof (uint64_t)));
1124
1125 return (lwb);
1126 }
1127
1128 itx_t *
1129 zil_itx_create(uint64_t txtype, size_t lrsize)
1130 {
1131 itx_t *itx;
1132
1133 lrsize = P2ROUNDUP_TYPED(lrsize, sizeof (uint64_t), size_t);
1134
1135 itx = kmem_alloc(offsetof(itx_t, itx_lr) + lrsize, KM_SLEEP);
1136 itx->itx_lr.lrc_txtype = txtype;
1137 itx->itx_lr.lrc_reclen = lrsize;
1138 itx->itx_sod = lrsize; /* if write & WR_NEED_COPY will be increased */
1139 itx->itx_lr.lrc_seq = 0; /* defensive */
1140 itx->itx_sync = B_TRUE; /* default is synchronous */
1141
1142 return (itx);
1143 }
1144
1145 void
1146 zil_itx_destroy(itx_t *itx)
1147 {
1148 kmem_free(itx, offsetof(itx_t, itx_lr) + itx->itx_lr.lrc_reclen);
1149 }
1150
1151 /*
1152 * Free up the sync and async itxs. The itxs_t has already been detached
1153 * so no locks are needed.
1154 */
1155 static void
1156 zil_itxg_clean(itxs_t *itxs)
1157 {
1158 itx_t *itx;
1159 list_t *list;
1160 avl_tree_t *t;
1161 void *cookie;
1162 itx_async_node_t *ian;
1163
1164 list = &itxs->i_sync_list;
1165 while ((itx = list_head(list)) != NULL) {
1166 list_remove(list, itx);
1167 kmem_free(itx, offsetof(itx_t, itx_lr) +
1168 itx->itx_lr.lrc_reclen);
1169 }
1170
1171 cookie = NULL;
1172 t = &itxs->i_async_tree;
1173 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) {
1174 list = &ian->ia_list;
1175 while ((itx = list_head(list)) != NULL) {
1176 list_remove(list, itx);
1177 kmem_free(itx, offsetof(itx_t, itx_lr) +
1178 itx->itx_lr.lrc_reclen);
1179 }
1180 list_destroy(list);
1181 kmem_free(ian, sizeof (itx_async_node_t));
1182 }
1183 avl_destroy(t);
1184
1185 kmem_free(itxs, sizeof (itxs_t));
1186 }
1187
1188 static int
1189 zil_aitx_compare(const void *x1, const void *x2)
1190 {
1191 const uint64_t o1 = ((itx_async_node_t *)x1)->ia_foid;
1192 const uint64_t o2 = ((itx_async_node_t *)x2)->ia_foid;
1193
1194 if (o1 < o2)
1195 return (-1);
1196 if (o1 > o2)
1197 return (1);
1198
1199 return (0);
1200 }
1201
1202 /*
1203 * Remove all async itx with the given oid.
1204 */
1205 static void
1206 zil_remove_async(zilog_t *zilog, uint64_t oid)
1207 {
1208 uint64_t otxg, txg;
1209 itx_async_node_t *ian;
1210 avl_tree_t *t;
1211 avl_index_t where;
1212 list_t clean_list;
1213 itx_t *itx;
1214
1215 ASSERT(oid != 0);
1216 list_create(&clean_list, sizeof (itx_t), offsetof(itx_t, itx_node));
1217
1218 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */
1219 otxg = ZILTEST_TXG;
1220 else
1221 otxg = spa_last_synced_txg(zilog->zl_spa) + 1;
1222
1223 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) {
1224 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK];
1225
1226 mutex_enter(&itxg->itxg_lock);
1227 if (itxg->itxg_txg != txg) {
1228 mutex_exit(&itxg->itxg_lock);
1229 continue;
1230 }
1231
1232 /*
1233 * Locate the object node and append its list.
1234 */
1235 t = &itxg->itxg_itxs->i_async_tree;
1236 ian = avl_find(t, &oid, &where);
1237 if (ian != NULL)
1238 list_move_tail(&clean_list, &ian->ia_list);
1239 mutex_exit(&itxg->itxg_lock);
1240 }
1241 while ((itx = list_head(&clean_list)) != NULL) {
1242 list_remove(&clean_list, itx);
1243 kmem_free(itx, offsetof(itx_t, itx_lr) +
1244 itx->itx_lr.lrc_reclen);
1245 }
1246 list_destroy(&clean_list);
1247 }
1248
1249 void
1250 zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx)
1251 {
1252 uint64_t txg;
1253 itxg_t *itxg;
1254 itxs_t *itxs, *clean = NULL;
1255
1256 /*
1257 * Object ids can be re-instantiated in the next txg so
1258 * remove any async transactions to avoid future leaks.
1259 * This can happen if a fsync occurs on the re-instantiated
1260 * object for a WR_INDIRECT or WR_NEED_COPY write, which gets
1261 * the new file data and flushes a write record for the old object.
1262 */
1263 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_REMOVE)
1264 zil_remove_async(zilog, itx->itx_oid);
1265
1266 /*
1267 * Ensure the data of a renamed file is committed before the rename.
1268 */
1269 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_RENAME)
1270 zil_async_to_sync(zilog, itx->itx_oid);
1271
1272 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX)
1273 txg = ZILTEST_TXG;
1274 else
1275 txg = dmu_tx_get_txg(tx);
1276
1277 itxg = &zilog->zl_itxg[txg & TXG_MASK];
1278 mutex_enter(&itxg->itxg_lock);
1279 itxs = itxg->itxg_itxs;
1280 if (itxg->itxg_txg != txg) {
1281 if (itxs != NULL) {
1282 /*
1283 * The zil_clean callback hasn't got around to cleaning
1284 * this itxg. Save the itxs for release below.
1285 * This should be rare.
1286 */
1287 atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod);
1288 itxg->itxg_sod = 0;
1289 clean = itxg->itxg_itxs;
1290 }
1291 ASSERT(itxg->itxg_sod == 0);
1292 itxg->itxg_txg = txg;
1293 itxs = itxg->itxg_itxs = kmem_zalloc(sizeof (itxs_t), KM_SLEEP);
1294
1295 list_create(&itxs->i_sync_list, sizeof (itx_t),
1296 offsetof(itx_t, itx_node));
1297 avl_create(&itxs->i_async_tree, zil_aitx_compare,
1298 sizeof (itx_async_node_t),
1299 offsetof(itx_async_node_t, ia_node));
1300 }
1301 if (itx->itx_sync) {
1302 list_insert_tail(&itxs->i_sync_list, itx);
1303 atomic_add_64(&zilog->zl_itx_list_sz, itx->itx_sod);
1304 itxg->itxg_sod += itx->itx_sod;
1305 } else {
1306 avl_tree_t *t = &itxs->i_async_tree;
1307 uint64_t foid = ((lr_ooo_t *)&itx->itx_lr)->lr_foid;
1308 itx_async_node_t *ian;
1309 avl_index_t where;
1310
1311 ian = avl_find(t, &foid, &where);
1312 if (ian == NULL) {
1313 ian = kmem_alloc(sizeof (itx_async_node_t), KM_SLEEP);
1314 list_create(&ian->ia_list, sizeof (itx_t),
1315 offsetof(itx_t, itx_node));
1316 ian->ia_foid = foid;
1317 avl_insert(t, ian, where);
1318 }
1319 list_insert_tail(&ian->ia_list, itx);
1320 }
1321
1322 itx->itx_lr.lrc_txg = dmu_tx_get_txg(tx);
1323 zilog_dirty(zilog, txg);
1324 mutex_exit(&itxg->itxg_lock);
1325
1326 /* Release the old itxs now we've dropped the lock */
1327 if (clean != NULL)
1328 zil_itxg_clean(clean);
1329 }
1330
1331 /*
1332 * If there are any in-memory intent log transactions which have now been
1333 * synced then start up a taskq to free them. We should only do this after we
1334 * have written out the uberblocks (i.e. txg has been comitted) so that
1335 * don't inadvertently clean out in-memory log records that would be required
1336 * by zil_commit().
1337 */
1338 void
1339 zil_clean(zilog_t *zilog, uint64_t synced_txg)
1340 {
1341 itxg_t *itxg = &zilog->zl_itxg[synced_txg & TXG_MASK];
1342 itxs_t *clean_me;
1343
1344 mutex_enter(&itxg->itxg_lock);
1345 if (itxg->itxg_itxs == NULL || itxg->itxg_txg == ZILTEST_TXG) {
1346 mutex_exit(&itxg->itxg_lock);
1347 return;
1348 }
1349 ASSERT3U(itxg->itxg_txg, <=, synced_txg);
1350 ASSERT(itxg->itxg_txg != 0);
1351 ASSERT(zilog->zl_clean_taskq != NULL);
1352 atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod);
1353 itxg->itxg_sod = 0;
1354 clean_me = itxg->itxg_itxs;
1355 itxg->itxg_itxs = NULL;
1356 itxg->itxg_txg = 0;
1357 mutex_exit(&itxg->itxg_lock);
1358 /*
1359 * Preferably start a task queue to free up the old itxs but
1360 * if taskq_dispatch can't allocate resources to do that then
1361 * free it in-line. This should be rare. Note, using TQ_SLEEP
1362 * created a bad performance problem.
1363 */
1364 if (taskq_dispatch(zilog->zl_clean_taskq,
1365 (void (*)(void *))zil_itxg_clean, clean_me, TQ_NOSLEEP) == NULL)
1366 zil_itxg_clean(clean_me);
1367 }
1368
1369 /*
1370 * Get the list of itxs to commit into zl_itx_commit_list.
1371 */
1372 static void
1373 zil_get_commit_list(zilog_t *zilog)
1374 {
1375 uint64_t otxg, txg;
1376 list_t *commit_list = &zilog->zl_itx_commit_list;
1377 uint64_t push_sod = 0;
1378
1379 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */
1380 otxg = ZILTEST_TXG;
1381 else
1382 otxg = spa_last_synced_txg(zilog->zl_spa) + 1;
1383
1384 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) {
1385 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK];
1386
1387 mutex_enter(&itxg->itxg_lock);
1388 if (itxg->itxg_txg != txg) {
1389 mutex_exit(&itxg->itxg_lock);
1390 continue;
1391 }
1392
1393 list_move_tail(commit_list, &itxg->itxg_itxs->i_sync_list);
1394 push_sod += itxg->itxg_sod;
1395 itxg->itxg_sod = 0;
1396
1397 mutex_exit(&itxg->itxg_lock);
1398 }
1399 atomic_add_64(&zilog->zl_itx_list_sz, -push_sod);
1400 }
1401
1402 /*
1403 * Move the async itxs for a specified object to commit into sync lists.
1404 */
1405 static void
1406 zil_async_to_sync(zilog_t *zilog, uint64_t foid)
1407 {
1408 uint64_t otxg, txg;
1409 itx_async_node_t *ian;
1410 avl_tree_t *t;
1411 avl_index_t where;
1412
1413 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */
1414 otxg = ZILTEST_TXG;
1415 else
1416 otxg = spa_last_synced_txg(zilog->zl_spa) + 1;
1417
1418 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) {
1419 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK];
1420
1421 mutex_enter(&itxg->itxg_lock);
1422 if (itxg->itxg_txg != txg) {
1423 mutex_exit(&itxg->itxg_lock);
1424 continue;
1425 }
1426
1427 /*
1428 * If a foid is specified then find that node and append its
1429 * list. Otherwise walk the tree appending all the lists
1430 * to the sync list. We add to the end rather than the
1431 * beginning to ensure the create has happened.
1432 */
1433 t = &itxg->itxg_itxs->i_async_tree;
1434 if (foid != 0) {
1435 ian = avl_find(t, &foid, &where);
1436 if (ian != NULL) {
1437 list_move_tail(&itxg->itxg_itxs->i_sync_list,
1438 &ian->ia_list);
1439 }
1440 } else {
1441 void *cookie = NULL;
1442
1443 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) {
1444 list_move_tail(&itxg->itxg_itxs->i_sync_list,
1445 &ian->ia_list);
1446 list_destroy(&ian->ia_list);
1447 kmem_free(ian, sizeof (itx_async_node_t));
1448 }
1449 }
1450 mutex_exit(&itxg->itxg_lock);
1451 }
1452 }
1453
1454 static void
1455 zil_commit_writer(zilog_t *zilog)
1456 {
1457 uint64_t txg;
1458 itx_t *itx;
1459 lwb_t *lwb;
1460 spa_t *spa = zilog->zl_spa;
1461 int error = 0;
1462
1463 ASSERT(zilog->zl_root_zio == NULL);
1464
1465 mutex_exit(&zilog->zl_lock);
1466
1467 zil_get_commit_list(zilog);
1468
1469 /*
1470 * Return if there's nothing to commit before we dirty the fs by
1471 * calling zil_create().
1472 */
1473 if (list_head(&zilog->zl_itx_commit_list) == NULL) {
1474 mutex_enter(&zilog->zl_lock);
1475 return;
1476 }
1477
1478 if (zilog->zl_suspend) {
1479 lwb = NULL;
1480 } else {
1481 lwb = list_tail(&zilog->zl_lwb_list);
1482 if (lwb == NULL)
1483 lwb = zil_create(zilog);
1484 }
1485
1486 DTRACE_PROBE1(zil__cw1, zilog_t *, zilog);
1487 while (itx = list_head(&zilog->zl_itx_commit_list)) {
1488 txg = itx->itx_lr.lrc_txg;
1489 ASSERT(txg);
1490
1491 if (txg > spa_last_synced_txg(spa) || txg > spa_freeze_txg(spa))
1492 lwb = zil_lwb_commit(zilog, itx, lwb);
1493 list_remove(&zilog->zl_itx_commit_list, itx);
1494 kmem_free(itx, offsetof(itx_t, itx_lr)
1495 + itx->itx_lr.lrc_reclen);
1496 }
1497 DTRACE_PROBE1(zil__cw2, zilog_t *, zilog);
1498
1499 /* write the last block out */
1500 if (lwb != NULL && lwb->lwb_zio != NULL)
1501 lwb = zil_lwb_write_start(zilog, lwb);
1502
1503 zilog->zl_cur_used = 0;
1504
1505 /*
1506 * Wait if necessary for the log blocks to be on stable storage.
1507 */
1508 if (zilog->zl_root_zio) {
1509 error = zio_wait(zilog->zl_root_zio);
1510 zilog->zl_root_zio = NULL;
1511 zil_flush_vdevs(zilog);
1512 }
1513
1514 if (error || lwb == NULL)
1515 txg_wait_synced(zilog->zl_dmu_pool, 0);
1516
1517 mutex_enter(&zilog->zl_lock);
1518
1519 /*
1520 * Remember the highest committed log sequence number for ztest.
1521 * We only update this value when all the log writes succeeded,
1522 * because ztest wants to ASSERT that it got the whole log chain.
1523 */
1524 if (error == 0 && lwb != NULL)
1525 zilog->zl_commit_lr_seq = zilog->zl_lr_seq;
1526 }
1527
1528 /*
1529 * Commit zfs transactions to stable storage.
1530 * If foid is 0 push out all transactions, otherwise push only those
1531 * for that object or might reference that object.
1532 *
1533 * itxs are committed in batches. In a heavily stressed zil there will be
1534 * a commit writer thread who is writing out a bunch of itxs to the log
1535 * for a set of committing threads (cthreads) in the same batch as the writer.
1536 * Those cthreads are all waiting on the same cv for that batch.
1537 *
1538 * There will also be a different and growing batch of threads that are
1539 * waiting to commit (qthreads). When the committing batch completes
1540 * a transition occurs such that the cthreads exit and the qthreads become
1541 * cthreads. One of the new cthreads becomes the writer thread for the
1542 * batch. Any new threads arriving become new qthreads.
1543 *
1544 * Only 2 condition variables are needed and there's no transition
1545 * between the two cvs needed. They just flip-flop between qthreads
1546 * and cthreads.
1547 *
1548 * Using this scheme we can efficiently wakeup up only those threads
1549 * that have been committed.
1550 */
1551 void
1552 zil_commit(zilog_t *zilog, uint64_t foid)
1553 {
1554 uint64_t mybatch;
1555
1556 if (zilog->zl_sync == ZFS_SYNC_DISABLED)
1557 return;
1558
1559 /* move the async itxs for the foid to the sync queues */
1560 zil_async_to_sync(zilog, foid);
1561
1562 mutex_enter(&zilog->zl_lock);
1563 mybatch = zilog->zl_next_batch;
1564 while (zilog->zl_writer) {
1565 cv_wait(&zilog->zl_cv_batch[mybatch & 1], &zilog->zl_lock);
1566 if (mybatch <= zilog->zl_com_batch) {
1567 mutex_exit(&zilog->zl_lock);
1568 return;
1569 }
1570 }
1571
1572 zilog->zl_next_batch++;
1573 zilog->zl_writer = B_TRUE;
1574 zil_commit_writer(zilog);
1575 zilog->zl_com_batch = mybatch;
1576 zilog->zl_writer = B_FALSE;
1577 mutex_exit(&zilog->zl_lock);
1578
1579 /* wake up one thread to become the next writer */
1580 cv_signal(&zilog->zl_cv_batch[(mybatch+1) & 1]);
1581
1582 /* wake up all threads waiting for this batch to be committed */
1583 cv_broadcast(&zilog->zl_cv_batch[mybatch & 1]);
1584 }
1585
1586 /*
1587 * Called in syncing context to free committed log blocks and update log header.
1588 */
1589 void
1590 zil_sync(zilog_t *zilog, dmu_tx_t *tx)
1591 {
1592 zil_header_t *zh = zil_header_in_syncing_context(zilog);
1593 uint64_t txg = dmu_tx_get_txg(tx);
1594 spa_t *spa = zilog->zl_spa;
1595 uint64_t *replayed_seq = &zilog->zl_replayed_seq[txg & TXG_MASK];
1596 lwb_t *lwb;
1597
1598 /*
1599 * We don't zero out zl_destroy_txg, so make sure we don't try
1600 * to destroy it twice.
1601 */
1602 if (spa_sync_pass(spa) != 1)
1603 return;
1604
1605 mutex_enter(&zilog->zl_lock);
1606
1607 ASSERT(zilog->zl_stop_sync == 0);
1608
1609 if (*replayed_seq != 0) {
1610 ASSERT(zh->zh_replay_seq < *replayed_seq);
1611 zh->zh_replay_seq = *replayed_seq;
1612 *replayed_seq = 0;
1613 }
1614
1615 if (zilog->zl_destroy_txg == txg) {
1616 blkptr_t blk = zh->zh_log;
1617
1618 ASSERT(list_head(&zilog->zl_lwb_list) == NULL);
1619
1620 bzero(zh, sizeof (zil_header_t));
1621 bzero(zilog->zl_replayed_seq, sizeof (zilog->zl_replayed_seq));
1622
1623 if (zilog->zl_keep_first) {
1624 /*
1625 * If this block was part of log chain that couldn't
1626 * be claimed because a device was missing during
1627 * zil_claim(), but that device later returns,
1628 * then this block could erroneously appear valid.
1629 * To guard against this, assign a new GUID to the new
1630 * log chain so it doesn't matter what blk points to.
1631 */
1632 zil_init_log_chain(zilog, &blk);
1633 zh->zh_log = blk;
1634 }
1635 }
1636
1637 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) {
1638 zh->zh_log = lwb->lwb_blk;
1639 if (lwb->lwb_buf != NULL || lwb->lwb_max_txg > txg)
1640 break;
1641 list_remove(&zilog->zl_lwb_list, lwb);
1642 zio_free_zil(spa, txg, &lwb->lwb_blk);
1643 kmem_cache_free(zil_lwb_cache, lwb);
1644
1645 /*
1646 * If we don't have anything left in the lwb list then
1647 * we've had an allocation failure and we need to zero
1648 * out the zil_header blkptr so that we don't end
1649 * up freeing the same block twice.
1650 */
1651 if (list_head(&zilog->zl_lwb_list) == NULL)
1652 BP_ZERO(&zh->zh_log);
1653 }
1654 mutex_exit(&zilog->zl_lock);
1655 }
1656
1657 void
1658 zil_init(void)
1659 {
1660 zil_lwb_cache = kmem_cache_create("zil_lwb_cache",
1661 sizeof (struct lwb), 0, NULL, NULL, NULL, NULL, NULL, 0);
1662 }
1663
1664 void
1665 zil_fini(void)
1666 {
1667 kmem_cache_destroy(zil_lwb_cache);
1668 }
1669
1670 void
1671 zil_set_sync(zilog_t *zilog, uint64_t sync)
1672 {
1673 zilog->zl_sync = sync;
1674 }
1675
1676 void
1677 zil_set_logbias(zilog_t *zilog, uint64_t logbias)
1678 {
1679 zilog->zl_logbias = logbias;
1680 }
1681
1682 zilog_t *
1683 zil_alloc(objset_t *os, zil_header_t *zh_phys)
1684 {
1685 zilog_t *zilog;
1686
1687 zilog = kmem_zalloc(sizeof (zilog_t), KM_SLEEP);
1688
1689 zilog->zl_header = zh_phys;
1690 zilog->zl_os = os;
1691 zilog->zl_spa = dmu_objset_spa(os);
1692 zilog->zl_dmu_pool = dmu_objset_pool(os);
1693 zilog->zl_destroy_txg = TXG_INITIAL - 1;
1694 zilog->zl_logbias = dmu_objset_logbias(os);
1695 zilog->zl_sync = dmu_objset_syncprop(os);
1696 zilog->zl_next_batch = 1;
1697
1698 mutex_init(&zilog->zl_lock, NULL, MUTEX_DEFAULT, NULL);
1699
1700 for (int i = 0; i < TXG_SIZE; i++) {
1701 mutex_init(&zilog->zl_itxg[i].itxg_lock, NULL,
1702 MUTEX_DEFAULT, NULL);
1703 }
1704
1705 list_create(&zilog->zl_lwb_list, sizeof (lwb_t),
1706 offsetof(lwb_t, lwb_node));
1707
1708 list_create(&zilog->zl_itx_commit_list, sizeof (itx_t),
1709 offsetof(itx_t, itx_node));
1710
1711 mutex_init(&zilog->zl_vdev_lock, NULL, MUTEX_DEFAULT, NULL);
1712
1713 avl_create(&zilog->zl_vdev_tree, zil_vdev_compare,
1714 sizeof (zil_vdev_node_t), offsetof(zil_vdev_node_t, zv_node));
1715
1716 cv_init(&zilog->zl_cv_writer, NULL, CV_DEFAULT, NULL);
1717 cv_init(&zilog->zl_cv_suspend, NULL, CV_DEFAULT, NULL);
1718 cv_init(&zilog->zl_cv_batch[0], NULL, CV_DEFAULT, NULL);
1719 cv_init(&zilog->zl_cv_batch[1], NULL, CV_DEFAULT, NULL);
1720
1721 return (zilog);
1722 }
1723
1724 void
1725 zil_free(zilog_t *zilog)
1726 {
1727 zilog->zl_stop_sync = 1;
1728
1729 ASSERT0(zilog->zl_suspend);
1730 ASSERT0(zilog->zl_suspending);
1731
1732 ASSERT(list_is_empty(&zilog->zl_lwb_list));
1733 list_destroy(&zilog->zl_lwb_list);
1734
1735 avl_destroy(&zilog->zl_vdev_tree);
1736 mutex_destroy(&zilog->zl_vdev_lock);
1737
1738 ASSERT(list_is_empty(&zilog->zl_itx_commit_list));
1739 list_destroy(&zilog->zl_itx_commit_list);
1740
1741 for (int i = 0; i < TXG_SIZE; i++) {
1742 /*
1743 * It's possible for an itx to be generated that doesn't dirty
1744 * a txg (e.g. ztest TX_TRUNCATE). So there's no zil_clean()
1745 * callback to remove the entry. We remove those here.
1746 *
1747 * Also free up the ziltest itxs.
1748 */
1749 if (zilog->zl_itxg[i].itxg_itxs)
1750 zil_itxg_clean(zilog->zl_itxg[i].itxg_itxs);
1751 mutex_destroy(&zilog->zl_itxg[i].itxg_lock);
1752 }
1753
1754 mutex_destroy(&zilog->zl_lock);
1755
1756 cv_destroy(&zilog->zl_cv_writer);
1757 cv_destroy(&zilog->zl_cv_suspend);
1758 cv_destroy(&zilog->zl_cv_batch[0]);
1759 cv_destroy(&zilog->zl_cv_batch[1]);
1760
1761 kmem_free(zilog, sizeof (zilog_t));
1762 }
1763
1764 /*
1765 * Open an intent log.
1766 */
1767 zilog_t *
1768 zil_open(objset_t *os, zil_get_data_t *get_data)
1769 {
1770 zilog_t *zilog = dmu_objset_zil(os);
1771
1772 ASSERT(zilog->zl_clean_taskq == NULL);
1773 ASSERT(zilog->zl_get_data == NULL);
1774 ASSERT(list_is_empty(&zilog->zl_lwb_list));
1775
1776 zilog->zl_get_data = get_data;
1777 zilog->zl_clean_taskq = taskq_create("zil_clean", 1, minclsyspri,
1778 2, 2, TASKQ_PREPOPULATE);
1779
1780 return (zilog);
1781 }
1782
1783 /*
1784 * Close an intent log.
1785 */
1786 void
1787 zil_close(zilog_t *zilog)
1788 {
1789 lwb_t *lwb;
1790 uint64_t txg = 0;
1791
1792 zil_commit(zilog, 0); /* commit all itx */
1793
1794 /*
1795 * The lwb_max_txg for the stubby lwb will reflect the last activity
1796 * for the zil. After a txg_wait_synced() on the txg we know all the
1797 * callbacks have occurred that may clean the zil. Only then can we
1798 * destroy the zl_clean_taskq.
1799 */
1800 mutex_enter(&zilog->zl_lock);
1801 lwb = list_tail(&zilog->zl_lwb_list);
1802 if (lwb != NULL)
1803 txg = lwb->lwb_max_txg;
1804 mutex_exit(&zilog->zl_lock);
1805 if (txg)
1806 txg_wait_synced(zilog->zl_dmu_pool, txg);
1807 ASSERT(!zilog_is_dirty(zilog));
1808
1809 taskq_destroy(zilog->zl_clean_taskq);
1810 zilog->zl_clean_taskq = NULL;
1811 zilog->zl_get_data = NULL;
1812
1813 /*
1814 * We should have only one LWB left on the list; remove it now.
1815 */
1816 mutex_enter(&zilog->zl_lock);
1817 lwb = list_head(&zilog->zl_lwb_list);
1818 if (lwb != NULL) {
1819 ASSERT(lwb == list_tail(&zilog->zl_lwb_list));
1820 list_remove(&zilog->zl_lwb_list, lwb);
1821 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
1822 kmem_cache_free(zil_lwb_cache, lwb);
1823 }
1824 mutex_exit(&zilog->zl_lock);
1825 }
1826
1827 static char *suspend_tag = "zil suspending";
1828
1829 /*
1830 * Suspend an intent log. While in suspended mode, we still honor
1831 * synchronous semantics, but we rely on txg_wait_synced() to do it.
1832 * On old version pools, we suspend the log briefly when taking a
1833 * snapshot so that it will have an empty intent log.
1834 *
1835 * Long holds are not really intended to be used the way we do here --
1836 * held for such a short time. A concurrent caller of dsl_dataset_long_held()
1837 * could fail. Therefore we take pains to only put a long hold if it is
1838 * actually necessary. Fortunately, it will only be necessary if the
1839 * objset is currently mounted (or the ZVOL equivalent). In that case it
1840 * will already have a long hold, so we are not really making things any worse.
1841 *
1842 * Ideally, we would locate the existing long-holder (i.e. the zfsvfs_t or
1843 * zvol_state_t), and use their mechanism to prevent their hold from being
1844 * dropped (e.g. VFS_HOLD()). However, that would be even more pain for
1845 * very little gain.
1846 *
1847 * if cookiep == NULL, this does both the suspend & resume.
1848 * Otherwise, it returns with the dataset "long held", and the cookie
1849 * should be passed into zil_resume().
1850 */
1851 int
1852 zil_suspend(const char *osname, void **cookiep)
1853 {
1854 objset_t *os;
1855 zilog_t *zilog;
1856 const zil_header_t *zh;
1857 int error;
1858
1859 error = dmu_objset_hold(osname, suspend_tag, &os);
1860 if (error != 0)
1861 return (error);
1862 zilog = dmu_objset_zil(os);
1863
1864 mutex_enter(&zilog->zl_lock);
1865 zh = zilog->zl_header;
1866
1867 if (zh->zh_flags & ZIL_REPLAY_NEEDED) { /* unplayed log */
1868 mutex_exit(&zilog->zl_lock);
1869 dmu_objset_rele(os, suspend_tag);
1870 return (SET_ERROR(EBUSY));
1871 }
1872
1873 /*
1874 * Don't put a long hold in the cases where we can avoid it. This
1875 * is when there is no cookie so we are doing a suspend & resume
1876 * (i.e. called from zil_vdev_offline()), and there's nothing to do
1877 * for the suspend because it's already suspended, or there's no ZIL.
1878 */
1879 if (cookiep == NULL && !zilog->zl_suspending &&
1880 (zilog->zl_suspend > 0 || BP_IS_HOLE(&zh->zh_log))) {
1881 mutex_exit(&zilog->zl_lock);
1882 dmu_objset_rele(os, suspend_tag);
1883 return (0);
1884 }
1885
1886 dsl_dataset_long_hold(dmu_objset_ds(os), suspend_tag);
1887 dsl_pool_rele(dmu_objset_pool(os), suspend_tag);
1888
1889 zilog->zl_suspend++;
1890
1891 if (zilog->zl_suspend > 1) {
1892 /*
1893 * Someone else is already suspending it.
1894 * Just wait for them to finish.
1895 */
1896
1897 while (zilog->zl_suspending)
1898 cv_wait(&zilog->zl_cv_suspend, &zilog->zl_lock);
1899 mutex_exit(&zilog->zl_lock);
1900
1901 if (cookiep == NULL)
1902 zil_resume(os);
1903 else
1904 *cookiep = os;
1905 return (0);
1906 }
1907
1908 /*
1909 * If there is no pointer to an on-disk block, this ZIL must not
1910 * be active (e.g. filesystem not mounted), so there's nothing
1911 * to clean up.
1912 */
1913 if (BP_IS_HOLE(&zh->zh_log)) {
1914 ASSERT(cookiep != NULL); /* fast path already handled */
1915
1916 *cookiep = os;
1917 mutex_exit(&zilog->zl_lock);
1918 return (0);
1919 }
1920
1921 zilog->zl_suspending = B_TRUE;
1922 mutex_exit(&zilog->zl_lock);
1923
1924 zil_commit(zilog, 0);
1925
1926 zil_destroy(zilog, B_FALSE);
1927
1928 mutex_enter(&zilog->zl_lock);
1929 zilog->zl_suspending = B_FALSE;
1930 cv_broadcast(&zilog->zl_cv_suspend);
1931 mutex_exit(&zilog->zl_lock);
1932
1933 if (cookiep == NULL)
1934 zil_resume(os);
1935 else
1936 *cookiep = os;
1937 return (0);
1938 }
1939
1940 void
1941 zil_resume(void *cookie)
1942 {
1943 objset_t *os = cookie;
1944 zilog_t *zilog = dmu_objset_zil(os);
1945
1946 mutex_enter(&zilog->zl_lock);
1947 ASSERT(zilog->zl_suspend != 0);
1948 zilog->zl_suspend--;
1949 mutex_exit(&zilog->zl_lock);
1950 dsl_dataset_long_rele(dmu_objset_ds(os), suspend_tag);
1951 dsl_dataset_rele(dmu_objset_ds(os), suspend_tag);
1952 }
1953
1954 typedef struct zil_replay_arg {
1955 zil_replay_func_t **zr_replay;
1956 void *zr_arg;
1957 boolean_t zr_byteswap;
1958 char *zr_lr;
1959 } zil_replay_arg_t;
1960
1961 static int
1962 zil_replay_error(zilog_t *zilog, lr_t *lr, int error)
1963 {
1964 char name[MAXNAMELEN];
1965
1966 zilog->zl_replaying_seq--; /* didn't actually replay this one */
1967
1968 dmu_objset_name(zilog->zl_os, name);
1969
1970 cmn_err(CE_WARN, "ZFS replay transaction error %d, "
1971 "dataset %s, seq 0x%llx, txtype %llu %s\n", error, name,
1972 (u_longlong_t)lr->lrc_seq,
1973 (u_longlong_t)(lr->lrc_txtype & ~TX_CI),
1974 (lr->lrc_txtype & TX_CI) ? "CI" : "");
1975
1976 return (error);
1977 }
1978
1979 static int
1980 zil_replay_log_record(zilog_t *zilog, lr_t *lr, void *zra, uint64_t claim_txg)
1981 {
1982 zil_replay_arg_t *zr = zra;
1983 const zil_header_t *zh = zilog->zl_header;
1984 uint64_t reclen = lr->lrc_reclen;
1985 uint64_t txtype = lr->lrc_txtype;
1986 int error = 0;
1987
1988 zilog->zl_replaying_seq = lr->lrc_seq;
1989
1990 if (lr->lrc_seq <= zh->zh_replay_seq) /* already replayed */
1991 return (0);
1992
1993 if (lr->lrc_txg < claim_txg) /* already committed */
1994 return (0);
1995
1996 /* Strip case-insensitive bit, still present in log record */
1997 txtype &= ~TX_CI;
1998
1999 if (txtype == 0 || txtype >= TX_MAX_TYPE)
2000 return (zil_replay_error(zilog, lr, EINVAL));
2001
2002 /*
2003 * If this record type can be logged out of order, the object
2004 * (lr_foid) may no longer exist. That's legitimate, not an error.
2005 */
2006 if (TX_OOO(txtype)) {
2007 error = dmu_object_info(zilog->zl_os,
2008 ((lr_ooo_t *)lr)->lr_foid, NULL);
2009 if (error == ENOENT || error == EEXIST)
2010 return (0);
2011 }
2012
2013 /*
2014 * Make a copy of the data so we can revise and extend it.
2015 */
2016 bcopy(lr, zr->zr_lr, reclen);
2017
2018 /*
2019 * If this is a TX_WRITE with a blkptr, suck in the data.
2020 */
2021 if (txtype == TX_WRITE && reclen == sizeof (lr_write_t)) {
2022 error = zil_read_log_data(zilog, (lr_write_t *)lr,
2023 zr->zr_lr + reclen);
2024 if (error != 0)
2025 return (zil_replay_error(zilog, lr, error));
2026 }
2027
2028 /*
2029 * The log block containing this lr may have been byteswapped
2030 * so that we can easily examine common fields like lrc_txtype.
2031 * However, the log is a mix of different record types, and only the
2032 * replay vectors know how to byteswap their records. Therefore, if
2033 * the lr was byteswapped, undo it before invoking the replay vector.
2034 */
2035 if (zr->zr_byteswap)
2036 byteswap_uint64_array(zr->zr_lr, reclen);
2037
2038 /*
2039 * We must now do two things atomically: replay this log record,
2040 * and update the log header sequence number to reflect the fact that
2041 * we did so. At the end of each replay function the sequence number
2042 * is updated if we are in replay mode.
2043 */
2044 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, zr->zr_byteswap);
2045 if (error != 0) {
2046 /*
2047 * The DMU's dnode layer doesn't see removes until the txg
2048 * commits, so a subsequent claim can spuriously fail with
2049 * EEXIST. So if we receive any error we try syncing out
2050 * any removes then retry the transaction. Note that we
2051 * specify B_FALSE for byteswap now, so we don't do it twice.
2052 */
2053 txg_wait_synced(spa_get_dsl(zilog->zl_spa), 0);
2054 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, B_FALSE);
2055 if (error != 0)
2056 return (zil_replay_error(zilog, lr, error));
2057 }
2058 return (0);
2059 }
2060
2061 /* ARGSUSED */
2062 static int
2063 zil_incr_blks(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg)
2064 {
2065 zilog->zl_replay_blks++;
2066
2067 return (0);
2068 }
2069
2070 /*
2071 * If this dataset has a non-empty intent log, replay it and destroy it.
2072 */
2073 void
2074 zil_replay(objset_t *os, void *arg, zil_replay_func_t *replay_func[TX_MAX_TYPE])
2075 {
2076 zilog_t *zilog = dmu_objset_zil(os);
2077 const zil_header_t *zh = zilog->zl_header;
2078 zil_replay_arg_t zr;
2079
2080 if ((zh->zh_flags & ZIL_REPLAY_NEEDED) == 0) {
2081 zil_destroy(zilog, B_TRUE);
2082 return;
2083 }
2084
2085 zr.zr_replay = replay_func;
2086 zr.zr_arg = arg;
2087 zr.zr_byteswap = BP_SHOULD_BYTESWAP(&zh->zh_log);
2088 zr.zr_lr = kmem_alloc(2 * SPA_MAXBLOCKSIZE, KM_SLEEP);
2089
2090 /*
2091 * Wait for in-progress removes to sync before starting replay.
2092 */
2093 txg_wait_synced(zilog->zl_dmu_pool, 0);
2094
2095 zilog->zl_replay = B_TRUE;
2096 zilog->zl_replay_time = ddi_get_lbolt();
2097 ASSERT(zilog->zl_replay_blks == 0);
2098 (void) zil_parse(zilog, zil_incr_blks, zil_replay_log_record, &zr,
2099 zh->zh_claim_txg);
2100 kmem_free(zr.zr_lr, 2 * SPA_MAXBLOCKSIZE);
2101
2102 zil_destroy(zilog, B_FALSE);
2103 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg);
2104 zilog->zl_replay = B_FALSE;
2105 }
2106
2107 boolean_t
2108 zil_replaying(zilog_t *zilog, dmu_tx_t *tx)
2109 {
2110 if (zilog->zl_sync == ZFS_SYNC_DISABLED)
2111 return (B_TRUE);
2112
2113 if (zilog->zl_replay) {
2114 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
2115 zilog->zl_replayed_seq[dmu_tx_get_txg(tx) & TXG_MASK] =
2116 zilog->zl_replaying_seq;
2117 return (B_TRUE);
2118 }
2119
2120 return (B_FALSE);
2121 }
2122
2123 /* ARGSUSED */
2124 int
2125 zil_vdev_offline(const char *osname, void *arg)
2126 {
2127 int error;
2128
2129 error = zil_suspend(osname, NULL);
2130 if (error != 0)
2131 return (SET_ERROR(EEXIST));
2132 return (0);
2133 }