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) 2013 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 uint32_t aflags = ARC_WAIT;
185 arc_buf_t *abuf = NULL;
186 zbookmark_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 bcopy(lr, dst, len);
224 *end = (char *)dst + len;
225 *nbp = zilc->zc_next_blk;
226 }
227 } else {
228 char *lr = abuf->b_data;
229 uint64_t size = BP_GET_LSIZE(bp);
230 zil_chain_t *zilc = (zil_chain_t *)(lr + size) - 1;
231
232 if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum,
233 sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk) ||
234 (zilc->zc_nused > (size - sizeof (*zilc)))) {
235 error = SET_ERROR(ECKSUM);
236 } else {
237 bcopy(lr, dst, zilc->zc_nused);
238 *end = (char *)dst + zilc->zc_nused;
239 *nbp = zilc->zc_next_blk;
240 }
241 }
242
243 VERIFY(arc_buf_remove_ref(abuf, &abuf));
244 }
245
246 return (error);
247 }
248
249 /*
250 * Read a TX_WRITE log data block.
251 */
252 static int
253 zil_read_log_data(zilog_t *zilog, const lr_write_t *lr, void *wbuf)
254 {
255 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL;
256 const blkptr_t *bp = &lr->lr_blkptr;
257 uint32_t aflags = ARC_WAIT;
258 arc_buf_t *abuf = NULL;
259 zbookmark_t zb;
260 int error;
261
262 if (BP_IS_HOLE(bp)) {
263 if (wbuf != NULL)
264 bzero(wbuf, MAX(BP_GET_LSIZE(bp), lr->lr_length));
265 return (0);
266 }
267
268 if (zilog->zl_header->zh_claim_txg == 0)
269 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB;
270
271 SET_BOOKMARK(&zb, dmu_objset_id(zilog->zl_os), lr->lr_foid,
272 ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp));
273
274 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf,
275 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb);
276
277 if (error == 0) {
278 if (wbuf != NULL)
279 bcopy(abuf->b_data, wbuf, arc_buf_size(abuf));
280 (void) arc_buf_remove_ref(abuf, &abuf);
281 }
282
283 return (error);
284 }
285
286 /*
287 * Parse the intent log, and call parse_func for each valid record within.
288 */
289 int
290 zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func,
291 zil_parse_lr_func_t *parse_lr_func, void *arg, uint64_t txg)
292 {
293 const zil_header_t *zh = zilog->zl_header;
294 boolean_t claimed = !!zh->zh_claim_txg;
295 uint64_t claim_blk_seq = claimed ? zh->zh_claim_blk_seq : UINT64_MAX;
296 uint64_t claim_lr_seq = claimed ? zh->zh_claim_lr_seq : UINT64_MAX;
297 uint64_t max_blk_seq = 0;
298 uint64_t max_lr_seq = 0;
299 uint64_t blk_count = 0;
300 uint64_t lr_count = 0;
301 blkptr_t blk, next_blk;
302 char *lrbuf, *lrp;
303 int error = 0;
304
305 /*
306 * Old logs didn't record the maximum zh_claim_lr_seq.
307 */
308 if (!(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID))
309 claim_lr_seq = UINT64_MAX;
310
311 /*
312 * Starting at the block pointed to by zh_log we read the log chain.
313 * For each block in the chain we strongly check that block to
314 * ensure its validity. We stop when an invalid block is found.
315 * For each block pointer in the chain we call parse_blk_func().
316 * For each record in each valid block we call parse_lr_func().
317 * If the log has been claimed, stop if we encounter a sequence
318 * number greater than the highest claimed sequence number.
319 */
320 lrbuf = zio_buf_alloc(SPA_MAXBLOCKSIZE);
321 zil_bp_tree_init(zilog);
322
323 for (blk = zh->zh_log; !BP_IS_HOLE(&blk); blk = next_blk) {
324 uint64_t blk_seq = blk.blk_cksum.zc_word[ZIL_ZC_SEQ];
325 int reclen;
326 char *end;
327
328 if (blk_seq > claim_blk_seq)
329 break;
330 if ((error = parse_blk_func(zilog, &blk, arg, txg)) != 0)
331 break;
332 ASSERT3U(max_blk_seq, <, blk_seq);
333 max_blk_seq = blk_seq;
334 blk_count++;
335
336 if (max_lr_seq == claim_lr_seq && max_blk_seq == claim_blk_seq)
337 break;
338
339 error = zil_read_log_block(zilog, &blk, &next_blk, lrbuf, &end);
340 if (error != 0)
341 break;
342
343 for (lrp = lrbuf; lrp < end; lrp += reclen) {
344 lr_t *lr = (lr_t *)lrp;
345 reclen = lr->lrc_reclen;
346 ASSERT3U(reclen, >=, sizeof (lr_t));
347 if (lr->lrc_seq > claim_lr_seq)
348 goto done;
349 if ((error = parse_lr_func(zilog, lr, arg, txg)) != 0)
350 goto done;
351 ASSERT3U(max_lr_seq, <, lr->lrc_seq);
352 max_lr_seq = lr->lrc_seq;
353 lr_count++;
354 }
355 }
356 done:
357 zilog->zl_parse_error = error;
358 zilog->zl_parse_blk_seq = max_blk_seq;
359 zilog->zl_parse_lr_seq = max_lr_seq;
360 zilog->zl_parse_blk_count = blk_count;
361 zilog->zl_parse_lr_count = lr_count;
362
363 ASSERT(!claimed || !(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID) ||
364 (max_blk_seq == claim_blk_seq && max_lr_seq == claim_lr_seq));
365
366 zil_bp_tree_fini(zilog);
367 zio_buf_free(lrbuf, SPA_MAXBLOCKSIZE);
368
369 return (error);
370 }
371
372 static int
373 zil_claim_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t first_txg)
374 {
375 /*
376 * Claim log block if not already committed and not already claimed.
377 * If tx == NULL, just verify that the block is claimable.
378 */
379 if (BP_IS_HOLE(bp) || bp->blk_birth < first_txg ||
380 zil_bp_tree_add(zilog, bp) != 0)
381 return (0);
382
383 return (zio_wait(zio_claim(NULL, zilog->zl_spa,
384 tx == NULL ? 0 : first_txg, bp, spa_claim_notify, NULL,
385 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB)));
386 }
387
388 static int
389 zil_claim_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t first_txg)
390 {
391 lr_write_t *lr = (lr_write_t *)lrc;
392 int error;
393
394 if (lrc->lrc_txtype != TX_WRITE)
395 return (0);
396
397 /*
398 * If the block is not readable, don't claim it. This can happen
399 * in normal operation when a log block is written to disk before
400 * some of the dmu_sync() blocks it points to. In this case, the
401 * transaction cannot have been committed to anyone (we would have
402 * waited for all writes to be stable first), so it is semantically
403 * correct to declare this the end of the log.
404 */
405 if (lr->lr_blkptr.blk_birth >= first_txg &&
406 (error = zil_read_log_data(zilog, lr, NULL)) != 0)
407 return (error);
408 return (zil_claim_log_block(zilog, &lr->lr_blkptr, tx, first_txg));
409 }
410
411 /* ARGSUSED */
412 static int
413 zil_free_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t claim_txg)
414 {
415 zio_free_zil(zilog->zl_spa, dmu_tx_get_txg(tx), bp);
416
417 return (0);
418 }
419
420 static int
421 zil_free_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t claim_txg)
422 {
423 lr_write_t *lr = (lr_write_t *)lrc;
424 blkptr_t *bp = &lr->lr_blkptr;
425
426 /*
427 * If we previously claimed it, we need to free it.
428 */
429 if (claim_txg != 0 && lrc->lrc_txtype == TX_WRITE &&
430 bp->blk_birth >= claim_txg && zil_bp_tree_add(zilog, bp) == 0 &&
431 !BP_IS_HOLE(bp))
432 zio_free(zilog->zl_spa, dmu_tx_get_txg(tx), bp);
433
434 return (0);
435 }
436
437 static lwb_t *
438 zil_alloc_lwb(zilog_t *zilog, blkptr_t *bp, uint64_t txg)
439 {
440 lwb_t *lwb;
441
442 lwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP);
443 lwb->lwb_zilog = zilog;
444 lwb->lwb_blk = *bp;
445 lwb->lwb_buf = zio_buf_alloc(BP_GET_LSIZE(bp));
446 lwb->lwb_max_txg = txg;
447 lwb->lwb_zio = NULL;
448 lwb->lwb_tx = NULL;
449 if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) {
450 lwb->lwb_nused = sizeof (zil_chain_t);
451 lwb->lwb_sz = BP_GET_LSIZE(bp);
452 } else {
453 lwb->lwb_nused = 0;
454 lwb->lwb_sz = BP_GET_LSIZE(bp) - sizeof (zil_chain_t);
455 }
456
457 mutex_enter(&zilog->zl_lock);
458 list_insert_tail(&zilog->zl_lwb_list, lwb);
459 mutex_exit(&zilog->zl_lock);
460
461 return (lwb);
462 }
463
464 /*
465 * Called when we create in-memory log transactions so that we know
466 * to cleanup the itxs at the end of spa_sync().
467 */
468 void
469 zilog_dirty(zilog_t *zilog, uint64_t txg)
470 {
471 dsl_pool_t *dp = zilog->zl_dmu_pool;
472 dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os);
473
474 if (dsl_dataset_is_snapshot(ds))
475 panic("dirtying snapshot!");
476
477 if (txg_list_add(&dp->dp_dirty_zilogs, zilog, txg)) {
478 /* up the hold count until we can be written out */
479 dmu_buf_add_ref(ds->ds_dbuf, zilog);
480 }
481 }
482
483 boolean_t
484 zilog_is_dirty(zilog_t *zilog)
485 {
486 dsl_pool_t *dp = zilog->zl_dmu_pool;
487
488 for (int t = 0; t < TXG_SIZE; t++) {
489 if (txg_list_member(&dp->dp_dirty_zilogs, zilog, t))
490 return (B_TRUE);
491 }
492 return (B_FALSE);
493 }
494
495 /*
496 * Create an on-disk intent log.
497 */
498 static lwb_t *
499 zil_create(zilog_t *zilog)
500 {
501 const zil_header_t *zh = zilog->zl_header;
502 lwb_t *lwb = NULL;
503 uint64_t txg = 0;
504 dmu_tx_t *tx = NULL;
505 blkptr_t blk;
506 int error = 0;
507
508 /*
509 * Wait for any previous destroy to complete.
510 */
511 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg);
512
513 ASSERT(zh->zh_claim_txg == 0);
514 ASSERT(zh->zh_replay_seq == 0);
515
516 blk = zh->zh_log;
517
518 /*
519 * Allocate an initial log block if:
520 * - there isn't one already
521 * - the existing block is the wrong endianess
522 */
523 if (BP_IS_HOLE(&blk) || BP_SHOULD_BYTESWAP(&blk)) {
524 tx = dmu_tx_create(zilog->zl_os);
525 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0);
526 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
527 txg = dmu_tx_get_txg(tx);
528
529 if (!BP_IS_HOLE(&blk)) {
530 zio_free_zil(zilog->zl_spa, txg, &blk);
531 BP_ZERO(&blk);
532 }
533
534 error = zio_alloc_zil(zilog->zl_spa, txg, &blk, NULL,
535 ZIL_MIN_BLKSZ, zilog->zl_logbias == ZFS_LOGBIAS_LATENCY);
536
537 if (error == 0)
538 zil_init_log_chain(zilog, &blk);
539 }
540
541 /*
542 * Allocate a log write buffer (lwb) for the first log block.
543 */
544 if (error == 0)
545 lwb = zil_alloc_lwb(zilog, &blk, txg);
546
547 /*
548 * If we just allocated the first log block, commit our transaction
549 * and wait for zil_sync() to stuff the block poiner into zh_log.
550 * (zh is part of the MOS, so we cannot modify it in open context.)
551 */
552 if (tx != NULL) {
553 dmu_tx_commit(tx);
554 txg_wait_synced(zilog->zl_dmu_pool, txg);
555 }
556
557 ASSERT(bcmp(&blk, &zh->zh_log, sizeof (blk)) == 0);
558
559 return (lwb);
560 }
561
562 /*
563 * In one tx, free all log blocks and clear the log header.
564 * If keep_first is set, then we're replaying a log with no content.
565 * We want to keep the first block, however, so that the first
566 * synchronous transaction doesn't require a txg_wait_synced()
567 * in zil_create(). We don't need to txg_wait_synced() here either
568 * when keep_first is set, because both zil_create() and zil_destroy()
569 * will wait for any in-progress destroys to complete.
570 */
571 void
572 zil_destroy(zilog_t *zilog, boolean_t keep_first)
573 {
574 const zil_header_t *zh = zilog->zl_header;
575 lwb_t *lwb;
576 dmu_tx_t *tx;
577 uint64_t txg;
578
579 /*
580 * Wait for any previous destroy to complete.
581 */
582 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg);
583
584 zilog->zl_old_header = *zh; /* debugging aid */
585
586 if (BP_IS_HOLE(&zh->zh_log))
587 return;
588
589 tx = dmu_tx_create(zilog->zl_os);
590 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0);
591 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
592 txg = dmu_tx_get_txg(tx);
593
594 mutex_enter(&zilog->zl_lock);
595
596 ASSERT3U(zilog->zl_destroy_txg, <, txg);
597 zilog->zl_destroy_txg = txg;
598 zilog->zl_keep_first = keep_first;
599
600 if (!list_is_empty(&zilog->zl_lwb_list)) {
601 ASSERT(zh->zh_claim_txg == 0);
602 VERIFY(!keep_first);
603 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) {
604 list_remove(&zilog->zl_lwb_list, lwb);
605 if (lwb->lwb_buf != NULL)
606 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
607 zio_free_zil(zilog->zl_spa, txg, &lwb->lwb_blk);
608 kmem_cache_free(zil_lwb_cache, lwb);
609 }
610 } else if (!keep_first) {
611 zil_destroy_sync(zilog, tx);
612 }
613 mutex_exit(&zilog->zl_lock);
614
615 dmu_tx_commit(tx);
616 }
617
618 void
619 zil_destroy_sync(zilog_t *zilog, dmu_tx_t *tx)
620 {
621 ASSERT(list_is_empty(&zilog->zl_lwb_list));
622 (void) zil_parse(zilog, zil_free_log_block,
623 zil_free_log_record, tx, zilog->zl_header->zh_claim_txg);
624 }
625
626 int
627 zil_claim(const char *osname, void *txarg)
628 {
629 dmu_tx_t *tx = txarg;
630 uint64_t first_txg = dmu_tx_get_txg(tx);
631 zilog_t *zilog;
632 zil_header_t *zh;
633 objset_t *os;
634 int error;
635
636 error = dmu_objset_own(osname, DMU_OST_ANY, B_FALSE, FTAG, &os);
637 if (error != 0) {
638 cmn_err(CE_WARN, "can't open objset for %s", osname);
639 return (0);
640 }
641
642 zilog = dmu_objset_zil(os);
643 zh = zil_header_in_syncing_context(zilog);
644
645 if (spa_get_log_state(zilog->zl_spa) == SPA_LOG_CLEAR) {
646 if (!BP_IS_HOLE(&zh->zh_log))
647 zio_free_zil(zilog->zl_spa, first_txg, &zh->zh_log);
648 BP_ZERO(&zh->zh_log);
649 dsl_dataset_dirty(dmu_objset_ds(os), tx);
650 dmu_objset_disown(os, FTAG);
651 return (0);
652 }
653
654 /*
655 * Claim all log blocks if we haven't already done so, and remember
656 * the highest claimed sequence number. This ensures that if we can
657 * read only part of the log now (e.g. due to a missing device),
658 * but we can read the entire log later, we will not try to replay
659 * or destroy beyond the last block we successfully claimed.
660 */
661 ASSERT3U(zh->zh_claim_txg, <=, first_txg);
662 if (zh->zh_claim_txg == 0 && !BP_IS_HOLE(&zh->zh_log)) {
663 (void) zil_parse(zilog, zil_claim_log_block,
664 zil_claim_log_record, tx, first_txg);
665 zh->zh_claim_txg = first_txg;
666 zh->zh_claim_blk_seq = zilog->zl_parse_blk_seq;
667 zh->zh_claim_lr_seq = zilog->zl_parse_lr_seq;
668 if (zilog->zl_parse_lr_count || zilog->zl_parse_blk_count > 1)
669 zh->zh_flags |= ZIL_REPLAY_NEEDED;
670 zh->zh_flags |= ZIL_CLAIM_LR_SEQ_VALID;
671 dsl_dataset_dirty(dmu_objset_ds(os), tx);
672 }
673
674 ASSERT3U(first_txg, ==, (spa_last_synced_txg(zilog->zl_spa) + 1));
675 dmu_objset_disown(os, FTAG);
676 return (0);
677 }
678
679 /*
680 * Check the log by walking the log chain.
681 * Checksum errors are ok as they indicate the end of the chain.
682 * Any other error (no device or read failure) returns an error.
683 */
684 int
685 zil_check_log_chain(const char *osname, void *tx)
686 {
687 zilog_t *zilog;
688 objset_t *os;
689 blkptr_t *bp;
690 int error;
691
692 ASSERT(tx == NULL);
693
694 error = dmu_objset_hold(osname, FTAG, &os);
695 if (error != 0) {
696 cmn_err(CE_WARN, "can't open objset for %s", osname);
697 return (0);
698 }
699
700 zilog = dmu_objset_zil(os);
701 bp = (blkptr_t *)&zilog->zl_header->zh_log;
702
703 /*
704 * Check the first block and determine if it's on a log device
705 * which may have been removed or faulted prior to loading this
706 * pool. If so, there's no point in checking the rest of the log
707 * as its content should have already been synced to the pool.
708 */
709 if (!BP_IS_HOLE(bp)) {
710 vdev_t *vd;
711 boolean_t valid = B_TRUE;
712
713 spa_config_enter(os->os_spa, SCL_STATE, FTAG, RW_READER);
714 vd = vdev_lookup_top(os->os_spa, DVA_GET_VDEV(&bp->blk_dva[0]));
715 if (vd->vdev_islog && vdev_is_dead(vd))
716 valid = vdev_log_state_valid(vd);
717 spa_config_exit(os->os_spa, SCL_STATE, FTAG);
718
719 if (!valid) {
720 dmu_objset_rele(os, FTAG);
721 return (0);
722 }
723 }
724
725 /*
726 * Because tx == NULL, zil_claim_log_block() will not actually claim
727 * any blocks, but just determine whether it is possible to do so.
728 * In addition to checking the log chain, zil_claim_log_block()
729 * will invoke zio_claim() with a done func of spa_claim_notify(),
730 * which will update spa_max_claim_txg. See spa_load() for details.
731 */
732 error = zil_parse(zilog, zil_claim_log_block, zil_claim_log_record, tx,
733 zilog->zl_header->zh_claim_txg ? -1ULL : spa_first_txg(os->os_spa));
734
735 dmu_objset_rele(os, FTAG);
736
737 return ((error == ECKSUM || error == ENOENT) ? 0 : error);
738 }
739
740 static int
741 zil_vdev_compare(const void *x1, const void *x2)
742 {
743 const uint64_t v1 = ((zil_vdev_node_t *)x1)->zv_vdev;
744 const uint64_t v2 = ((zil_vdev_node_t *)x2)->zv_vdev;
745
746 if (v1 < v2)
747 return (-1);
748 if (v1 > v2)
749 return (1);
750
751 return (0);
752 }
753
754 void
755 zil_add_block(zilog_t *zilog, const blkptr_t *bp)
756 {
757 avl_tree_t *t = &zilog->zl_vdev_tree;
758 avl_index_t where;
759 zil_vdev_node_t *zv, zvsearch;
760 int ndvas = BP_GET_NDVAS(bp);
761 int i;
762
763 if (zfs_nocacheflush)
764 return;
765
766 ASSERT(zilog->zl_writer);
767
768 /*
769 * Even though we're zl_writer, we still need a lock because the
770 * zl_get_data() callbacks may have dmu_sync() done callbacks
771 * that will run concurrently.
772 */
773 mutex_enter(&zilog->zl_vdev_lock);
774 for (i = 0; i < ndvas; i++) {
775 zvsearch.zv_vdev = DVA_GET_VDEV(&bp->blk_dva[i]);
776 if (avl_find(t, &zvsearch, &where) == NULL) {
777 zv = kmem_alloc(sizeof (*zv), KM_SLEEP);
778 zv->zv_vdev = zvsearch.zv_vdev;
779 avl_insert(t, zv, where);
780 }
781 }
782 mutex_exit(&zilog->zl_vdev_lock);
783 }
784
785 static void
786 zil_flush_vdevs(zilog_t *zilog)
787 {
788 spa_t *spa = zilog->zl_spa;
789 avl_tree_t *t = &zilog->zl_vdev_tree;
790 void *cookie = NULL;
791 zil_vdev_node_t *zv;
792 zio_t *zio;
793
794 ASSERT(zilog->zl_writer);
795
796 /*
797 * We don't need zl_vdev_lock here because we're the zl_writer,
798 * and all zl_get_data() callbacks are done.
799 */
800 if (avl_numnodes(t) == 0)
801 return;
802
803 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
804
805 zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
806
807 while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) {
808 vdev_t *vd = vdev_lookup_top(spa, zv->zv_vdev);
809 if (vd != NULL)
810 zio_flush(zio, vd);
811 kmem_free(zv, sizeof (*zv));
812 }
813
814 /*
815 * Wait for all the flushes to complete. Not all devices actually
816 * support the DKIOCFLUSHWRITECACHE ioctl, so it's OK if it fails.
817 */
818 (void) zio_wait(zio);
819
820 spa_config_exit(spa, SCL_STATE, FTAG);
821 }
822
823 /*
824 * Function called when a log block write completes
825 */
826 static void
827 zil_lwb_write_done(zio_t *zio)
828 {
829 lwb_t *lwb = zio->io_private;
830 zilog_t *zilog = lwb->lwb_zilog;
831 dmu_tx_t *tx = lwb->lwb_tx;
832
833 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF);
834 ASSERT(BP_GET_TYPE(zio->io_bp) == DMU_OT_INTENT_LOG);
835 ASSERT(BP_GET_LEVEL(zio->io_bp) == 0);
836 ASSERT(BP_GET_BYTEORDER(zio->io_bp) == ZFS_HOST_BYTEORDER);
837 ASSERT(!BP_IS_GANG(zio->io_bp));
838 ASSERT(!BP_IS_HOLE(zio->io_bp));
839 ASSERT(BP_GET_FILL(zio->io_bp) == 0);
840
841 /*
842 * Ensure the lwb buffer pointer is cleared before releasing
843 * the txg. If we have had an allocation failure and
844 * the txg is waiting to sync then we want want zil_sync()
845 * to remove the lwb so that it's not picked up as the next new
846 * one in zil_commit_writer(). zil_sync() will only remove
847 * the lwb if lwb_buf is null.
848 */
849 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
850 mutex_enter(&zilog->zl_lock);
851 lwb->lwb_buf = NULL;
852 lwb->lwb_tx = NULL;
853 mutex_exit(&zilog->zl_lock);
854
855 /*
856 * Now that we've written this log block, we have a stable pointer
857 * to the next block in the chain, so it's OK to let the txg in
858 * which we allocated the next block sync.
859 */
860 dmu_tx_commit(tx);
861 }
862
863 /*
864 * Initialize the io for a log block.
865 */
866 static void
867 zil_lwb_write_init(zilog_t *zilog, lwb_t *lwb)
868 {
869 zbookmark_t zb;
870
871 SET_BOOKMARK(&zb, lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_OBJSET],
872 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL,
873 lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_SEQ]);
874
875 if (zilog->zl_root_zio == NULL) {
876 zilog->zl_root_zio = zio_root(zilog->zl_spa, NULL, NULL,
877 ZIO_FLAG_CANFAIL);
878 }
879 if (lwb->lwb_zio == NULL) {
880 lwb->lwb_zio = zio_rewrite(zilog->zl_root_zio, zilog->zl_spa,
881 0, &lwb->lwb_blk, lwb->lwb_buf, BP_GET_LSIZE(&lwb->lwb_blk),
882 zil_lwb_write_done, lwb, ZIO_PRIORITY_SYNC_WRITE,
883 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE, &zb);
884 }
885 }
886
887 /*
888 * Define a limited set of intent log block sizes.
889 *
890 * These must be a multiple of 4KB. Note only the amount used (again
891 * aligned to 4KB) actually gets written. However, we can't always just
892 * allocate SPA_MAXBLOCKSIZE as the slog space could be exhausted.
893 */
894 uint64_t zil_block_buckets[] = {
895 4096, /* non TX_WRITE */
896 8192+4096, /* data base */
897 32*1024 + 4096, /* NFS writes */
898 UINT64_MAX
899 };
900
901 /*
902 * Use the slog as long as the logbias is 'latency' and the current commit size
903 * is less than the limit or the total list size is less than 2X the limit.
904 * Limit checking is disabled by setting zil_slog_limit to UINT64_MAX.
905 */
906 uint64_t zil_slog_limit = 1024 * 1024;
907 #define USE_SLOG(zilog) (((zilog)->zl_logbias == ZFS_LOGBIAS_LATENCY) && \
908 (((zilog)->zl_cur_used < zil_slog_limit) || \
909 ((zilog)->zl_itx_list_sz < (zil_slog_limit << 1))))
910
911 /*
912 * Start a log block write and advance to the next log block.
913 * Calls are serialized.
914 */
915 static lwb_t *
916 zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb)
917 {
918 lwb_t *nlwb = NULL;
919 zil_chain_t *zilc;
920 spa_t *spa = zilog->zl_spa;
921 blkptr_t *bp;
922 dmu_tx_t *tx;
923 uint64_t txg;
924 uint64_t zil_blksz, wsz;
925 int i, error;
926
927 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) {
928 zilc = (zil_chain_t *)lwb->lwb_buf;
929 bp = &zilc->zc_next_blk;
930 } else {
931 zilc = (zil_chain_t *)(lwb->lwb_buf + lwb->lwb_sz);
932 bp = &zilc->zc_next_blk;
933 }
934
935 ASSERT(lwb->lwb_nused <= lwb->lwb_sz);
936
937 /*
938 * Allocate the next block and save its address in this block
939 * before writing it in order to establish the log chain.
940 * Note that if the allocation of nlwb synced before we wrote
941 * the block that points at it (lwb), we'd leak it if we crashed.
942 * Therefore, we don't do dmu_tx_commit() until zil_lwb_write_done().
943 * We dirty the dataset to ensure that zil_sync() will be called
944 * to clean up in the event of allocation failure or I/O failure.
945 */
946 tx = dmu_tx_create(zilog->zl_os);
947 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0);
948 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
949 txg = dmu_tx_get_txg(tx);
950
951 lwb->lwb_tx = tx;
952
953 /*
954 * Log blocks are pre-allocated. Here we select the size of the next
955 * block, based on size used in the last block.
956 * - first find the smallest bucket that will fit the block from a
957 * limited set of block sizes. This is because it's faster to write
958 * blocks allocated from the same metaslab as they are adjacent or
959 * close.
960 * - next find the maximum from the new suggested size and an array of
961 * previous sizes. This lessens a picket fence effect of wrongly
962 * guesssing the size if we have a stream of say 2k, 64k, 2k, 64k
963 * requests.
964 *
965 * Note we only write what is used, but we can't just allocate
966 * the maximum block size because we can exhaust the available
967 * pool log space.
968 */
969 zil_blksz = zilog->zl_cur_used + sizeof (zil_chain_t);
970 for (i = 0; zil_blksz > zil_block_buckets[i]; i++)
971 continue;
972 zil_blksz = zil_block_buckets[i];
973 if (zil_blksz == UINT64_MAX)
974 zil_blksz = SPA_MAXBLOCKSIZE;
975 zilog->zl_prev_blks[zilog->zl_prev_rotor] = zil_blksz;
976 for (i = 0; i < ZIL_PREV_BLKS; i++)
977 zil_blksz = MAX(zil_blksz, zilog->zl_prev_blks[i]);
978 zilog->zl_prev_rotor = (zilog->zl_prev_rotor + 1) & (ZIL_PREV_BLKS - 1);
979
980 BP_ZERO(bp);
981 /* pass the old blkptr in order to spread log blocks across devs */
982 error = zio_alloc_zil(spa, txg, bp, &lwb->lwb_blk, zil_blksz,
983 USE_SLOG(zilog));
984 if (error == 0) {
985 ASSERT3U(bp->blk_birth, ==, txg);
986 bp->blk_cksum = lwb->lwb_blk.blk_cksum;
987 bp->blk_cksum.zc_word[ZIL_ZC_SEQ]++;
988
989 /*
990 * Allocate a new log write buffer (lwb).
991 */
992 nlwb = zil_alloc_lwb(zilog, bp, txg);
993
994 /* Record the block for later vdev flushing */
995 zil_add_block(zilog, &lwb->lwb_blk);
996 }
997
998 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) {
999 /* For Slim ZIL only write what is used. */
1000 wsz = P2ROUNDUP_TYPED(lwb->lwb_nused, ZIL_MIN_BLKSZ, uint64_t);
1001 ASSERT3U(wsz, <=, lwb->lwb_sz);
1002 zio_shrink(lwb->lwb_zio, wsz);
1003
1004 } else {
1005 wsz = lwb->lwb_sz;
1006 }
1007
1008 zilc->zc_pad = 0;
1009 zilc->zc_nused = lwb->lwb_nused;
1010 zilc->zc_eck.zec_cksum = lwb->lwb_blk.blk_cksum;
1011
1012 /*
1013 * clear unused data for security
1014 */
1015 bzero(lwb->lwb_buf + lwb->lwb_nused, wsz - lwb->lwb_nused);
1016
1017 zio_nowait(lwb->lwb_zio); /* Kick off the write for the old log block */
1018
1019 /*
1020 * If there was an allocation failure then nlwb will be null which
1021 * forces a txg_wait_synced().
1022 */
1023 return (nlwb);
1024 }
1025
1026 static lwb_t *
1027 zil_lwb_commit(zilog_t *zilog, itx_t *itx, lwb_t *lwb)
1028 {
1029 lr_t *lrc = &itx->itx_lr; /* common log record */
1030 lr_write_t *lrw = (lr_write_t *)lrc;
1031 char *lr_buf;
1032 uint64_t txg = lrc->lrc_txg;
1033 uint64_t reclen = lrc->lrc_reclen;
1034 uint64_t dlen = 0;
1035
1036 if (lwb == NULL)
1037 return (NULL);
1038
1039 ASSERT(lwb->lwb_buf != NULL);
1040 ASSERT(zilog_is_dirty(zilog) ||
1041 spa_freeze_txg(zilog->zl_spa) != UINT64_MAX);
1042
1043 if (lrc->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY)
1044 dlen = P2ROUNDUP_TYPED(
1045 lrw->lr_length, sizeof (uint64_t), uint64_t);
1046
1047 zilog->zl_cur_used += (reclen + dlen);
1048
1049 zil_lwb_write_init(zilog, lwb);
1050
1051 /*
1052 * If this record won't fit in the current log block, start a new one.
1053 */
1054 if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) {
1055 lwb = zil_lwb_write_start(zilog, lwb);
1056 if (lwb == NULL)
1057 return (NULL);
1058 zil_lwb_write_init(zilog, lwb);
1059 ASSERT(LWB_EMPTY(lwb));
1060 if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) {
1061 txg_wait_synced(zilog->zl_dmu_pool, txg);
1062 return (lwb);
1063 }
1064 }
1065
1066 lr_buf = lwb->lwb_buf + lwb->lwb_nused;
1067 bcopy(lrc, lr_buf, reclen);
1068 lrc = (lr_t *)lr_buf;
1069 lrw = (lr_write_t *)lrc;
1070
1071 /*
1072 * If it's a write, fetch the data or get its blkptr as appropriate.
1073 */
1074 if (lrc->lrc_txtype == TX_WRITE) {
1075 if (txg > spa_freeze_txg(zilog->zl_spa))
1076 txg_wait_synced(zilog->zl_dmu_pool, txg);
1077 if (itx->itx_wr_state != WR_COPIED) {
1078 char *dbuf;
1079 int error;
1080
1081 if (dlen) {
1082 ASSERT(itx->itx_wr_state == WR_NEED_COPY);
1083 dbuf = lr_buf + reclen;
1084 lrw->lr_common.lrc_reclen += dlen;
1085 } else {
1086 ASSERT(itx->itx_wr_state == WR_INDIRECT);
1087 dbuf = NULL;
1088 }
1089 error = zilog->zl_get_data(
1090 itx->itx_private, lrw, dbuf, lwb->lwb_zio);
1091 if (error == EIO) {
1092 txg_wait_synced(zilog->zl_dmu_pool, txg);
1093 return (lwb);
1094 }
1095 if (error != 0) {
1096 ASSERT(error == ENOENT || error == EEXIST ||
1097 error == EALREADY);
1098 return (lwb);
1099 }
1100 }
1101 }
1102
1103 /*
1104 * We're actually making an entry, so update lrc_seq to be the
1105 * log record sequence number. Note that this is generally not
1106 * equal to the itx sequence number because not all transactions
1107 * are synchronous, and sometimes spa_sync() gets there first.
1108 */
1109 lrc->lrc_seq = ++zilog->zl_lr_seq; /* we are single threaded */
1110 lwb->lwb_nused += reclen + dlen;
1111 lwb->lwb_max_txg = MAX(lwb->lwb_max_txg, txg);
1112 ASSERT3U(lwb->lwb_nused, <=, lwb->lwb_sz);
1113 ASSERT0(P2PHASE(lwb->lwb_nused, sizeof (uint64_t)));
1114
1115 return (lwb);
1116 }
1117
1118 itx_t *
1119 zil_itx_create(uint64_t txtype, size_t lrsize)
1120 {
1121 itx_t *itx;
1122
1123 lrsize = P2ROUNDUP_TYPED(lrsize, sizeof (uint64_t), size_t);
1124
1125 itx = kmem_alloc(offsetof(itx_t, itx_lr) + lrsize, KM_SLEEP);
1126 itx->itx_lr.lrc_txtype = txtype;
1127 itx->itx_lr.lrc_reclen = lrsize;
1128 itx->itx_sod = lrsize; /* if write & WR_NEED_COPY will be increased */
1129 itx->itx_lr.lrc_seq = 0; /* defensive */
1130 itx->itx_sync = B_TRUE; /* default is synchronous */
1131
1132 return (itx);
1133 }
1134
1135 void
1136 zil_itx_destroy(itx_t *itx)
1137 {
1138 kmem_free(itx, offsetof(itx_t, itx_lr) + itx->itx_lr.lrc_reclen);
1139 }
1140
1141 /*
1142 * Free up the sync and async itxs. The itxs_t has already been detached
1143 * so no locks are needed.
1144 */
1145 static void
1146 zil_itxg_clean(itxs_t *itxs)
1147 {
1148 itx_t *itx;
1149 list_t *list;
1150 avl_tree_t *t;
1151 void *cookie;
1152 itx_async_node_t *ian;
1153
1154 list = &itxs->i_sync_list;
1155 while ((itx = list_head(list)) != NULL) {
1156 list_remove(list, itx);
1157 kmem_free(itx, offsetof(itx_t, itx_lr) +
1158 itx->itx_lr.lrc_reclen);
1159 }
1160
1161 cookie = NULL;
1162 t = &itxs->i_async_tree;
1163 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) {
1164 list = &ian->ia_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 list_destroy(list);
1171 kmem_free(ian, sizeof (itx_async_node_t));
1172 }
1173 avl_destroy(t);
1174
1175 kmem_free(itxs, sizeof (itxs_t));
1176 }
1177
1178 static int
1179 zil_aitx_compare(const void *x1, const void *x2)
1180 {
1181 const uint64_t o1 = ((itx_async_node_t *)x1)->ia_foid;
1182 const uint64_t o2 = ((itx_async_node_t *)x2)->ia_foid;
1183
1184 if (o1 < o2)
1185 return (-1);
1186 if (o1 > o2)
1187 return (1);
1188
1189 return (0);
1190 }
1191
1192 /*
1193 * Remove all async itx with the given oid.
1194 */
1195 static void
1196 zil_remove_async(zilog_t *zilog, uint64_t oid)
1197 {
1198 uint64_t otxg, txg;
1199 itx_async_node_t *ian;
1200 avl_tree_t *t;
1201 avl_index_t where;
1202 list_t clean_list;
1203 itx_t *itx;
1204
1205 ASSERT(oid != 0);
1206 list_create(&clean_list, sizeof (itx_t), offsetof(itx_t, itx_node));
1207
1208 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */
1209 otxg = ZILTEST_TXG;
1210 else
1211 otxg = spa_last_synced_txg(zilog->zl_spa) + 1;
1212
1213 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) {
1214 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK];
1215
1216 mutex_enter(&itxg->itxg_lock);
1217 if (itxg->itxg_txg != txg) {
1218 mutex_exit(&itxg->itxg_lock);
1219 continue;
1220 }
1221
1222 /*
1223 * Locate the object node and append its list.
1224 */
1225 t = &itxg->itxg_itxs->i_async_tree;
1226 ian = avl_find(t, &oid, &where);
1227 if (ian != NULL)
1228 list_move_tail(&clean_list, &ian->ia_list);
1229 mutex_exit(&itxg->itxg_lock);
1230 }
1231 while ((itx = list_head(&clean_list)) != NULL) {
1232 list_remove(&clean_list, itx);
1233 kmem_free(itx, offsetof(itx_t, itx_lr) +
1234 itx->itx_lr.lrc_reclen);
1235 }
1236 list_destroy(&clean_list);
1237 }
1238
1239 void
1240 zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx)
1241 {
1242 uint64_t txg;
1243 itxg_t *itxg;
1244 itxs_t *itxs, *clean = NULL;
1245
1246 /*
1247 * Object ids can be re-instantiated in the next txg so
1248 * remove any async transactions to avoid future leaks.
1249 * This can happen if a fsync occurs on the re-instantiated
1250 * object for a WR_INDIRECT or WR_NEED_COPY write, which gets
1251 * the new file data and flushes a write record for the old object.
1252 */
1253 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_REMOVE)
1254 zil_remove_async(zilog, itx->itx_oid);
1255
1256 /*
1257 * Ensure the data of a renamed file is committed before the rename.
1258 */
1259 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_RENAME)
1260 zil_async_to_sync(zilog, itx->itx_oid);
1261
1262 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX)
1263 txg = ZILTEST_TXG;
1264 else
1265 txg = dmu_tx_get_txg(tx);
1266
1267 itxg = &zilog->zl_itxg[txg & TXG_MASK];
1268 mutex_enter(&itxg->itxg_lock);
1269 itxs = itxg->itxg_itxs;
1270 if (itxg->itxg_txg != txg) {
1271 if (itxs != NULL) {
1272 /*
1273 * The zil_clean callback hasn't got around to cleaning
1274 * this itxg. Save the itxs for release below.
1275 * This should be rare.
1276 */
1277 atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod);
1278 itxg->itxg_sod = 0;
1279 clean = itxg->itxg_itxs;
1280 }
1281 ASSERT(itxg->itxg_sod == 0);
1282 itxg->itxg_txg = txg;
1283 itxs = itxg->itxg_itxs = kmem_zalloc(sizeof (itxs_t), KM_SLEEP);
1284
1285 list_create(&itxs->i_sync_list, sizeof (itx_t),
1286 offsetof(itx_t, itx_node));
1287 avl_create(&itxs->i_async_tree, zil_aitx_compare,
1288 sizeof (itx_async_node_t),
1289 offsetof(itx_async_node_t, ia_node));
1290 }
1291 if (itx->itx_sync) {
1292 list_insert_tail(&itxs->i_sync_list, itx);
1293 atomic_add_64(&zilog->zl_itx_list_sz, itx->itx_sod);
1294 itxg->itxg_sod += itx->itx_sod;
1295 } else {
1296 avl_tree_t *t = &itxs->i_async_tree;
1297 uint64_t foid = ((lr_ooo_t *)&itx->itx_lr)->lr_foid;
1298 itx_async_node_t *ian;
1299 avl_index_t where;
1300
1301 ian = avl_find(t, &foid, &where);
1302 if (ian == NULL) {
1303 ian = kmem_alloc(sizeof (itx_async_node_t), KM_SLEEP);
1304 list_create(&ian->ia_list, sizeof (itx_t),
1305 offsetof(itx_t, itx_node));
1306 ian->ia_foid = foid;
1307 avl_insert(t, ian, where);
1308 }
1309 list_insert_tail(&ian->ia_list, itx);
1310 }
1311
1312 itx->itx_lr.lrc_txg = dmu_tx_get_txg(tx);
1313 zilog_dirty(zilog, txg);
1314 mutex_exit(&itxg->itxg_lock);
1315
1316 /* Release the old itxs now we've dropped the lock */
1317 if (clean != NULL)
1318 zil_itxg_clean(clean);
1319 }
1320
1321 /*
1322 * If there are any in-memory intent log transactions which have now been
1323 * synced then start up a taskq to free them. We should only do this after we
1324 * have written out the uberblocks (i.e. txg has been comitted) so that
1325 * don't inadvertently clean out in-memory log records that would be required
1326 * by zil_commit().
1327 */
1328 void
1329 zil_clean(zilog_t *zilog, uint64_t synced_txg)
1330 {
1331 itxg_t *itxg = &zilog->zl_itxg[synced_txg & TXG_MASK];
1332 itxs_t *clean_me;
1333
1334 mutex_enter(&itxg->itxg_lock);
1335 if (itxg->itxg_itxs == NULL || itxg->itxg_txg == ZILTEST_TXG) {
1336 mutex_exit(&itxg->itxg_lock);
1337 return;
1338 }
1339 ASSERT3U(itxg->itxg_txg, <=, synced_txg);
1340 ASSERT(itxg->itxg_txg != 0);
1341 ASSERT(zilog->zl_clean_taskq != NULL);
1342 atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod);
1343 itxg->itxg_sod = 0;
1344 clean_me = itxg->itxg_itxs;
1345 itxg->itxg_itxs = NULL;
1346 itxg->itxg_txg = 0;
1347 mutex_exit(&itxg->itxg_lock);
1348 /*
1349 * Preferably start a task queue to free up the old itxs but
1350 * if taskq_dispatch can't allocate resources to do that then
1351 * free it in-line. This should be rare. Note, using TQ_SLEEP
1352 * created a bad performance problem.
1353 */
1354 if (taskq_dispatch(zilog->zl_clean_taskq,
1355 (void (*)(void *))zil_itxg_clean, clean_me, TQ_NOSLEEP) == NULL)
1356 zil_itxg_clean(clean_me);
1357 }
1358
1359 /*
1360 * Get the list of itxs to commit into zl_itx_commit_list.
1361 */
1362 static void
1363 zil_get_commit_list(zilog_t *zilog)
1364 {
1365 uint64_t otxg, txg;
1366 list_t *commit_list = &zilog->zl_itx_commit_list;
1367 uint64_t push_sod = 0;
1368
1369 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */
1370 otxg = ZILTEST_TXG;
1371 else
1372 otxg = spa_last_synced_txg(zilog->zl_spa) + 1;
1373
1374 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) {
1375 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK];
1376
1377 mutex_enter(&itxg->itxg_lock);
1378 if (itxg->itxg_txg != txg) {
1379 mutex_exit(&itxg->itxg_lock);
1380 continue;
1381 }
1382
1383 list_move_tail(commit_list, &itxg->itxg_itxs->i_sync_list);
1384 push_sod += itxg->itxg_sod;
1385 itxg->itxg_sod = 0;
1386
1387 mutex_exit(&itxg->itxg_lock);
1388 }
1389 atomic_add_64(&zilog->zl_itx_list_sz, -push_sod);
1390 }
1391
1392 /*
1393 * Move the async itxs for a specified object to commit into sync lists.
1394 */
1395 static void
1396 zil_async_to_sync(zilog_t *zilog, uint64_t foid)
1397 {
1398 uint64_t otxg, txg;
1399 itx_async_node_t *ian;
1400 avl_tree_t *t;
1401 avl_index_t where;
1402
1403 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */
1404 otxg = ZILTEST_TXG;
1405 else
1406 otxg = spa_last_synced_txg(zilog->zl_spa) + 1;
1407
1408 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) {
1409 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK];
1410
1411 mutex_enter(&itxg->itxg_lock);
1412 if (itxg->itxg_txg != txg) {
1413 mutex_exit(&itxg->itxg_lock);
1414 continue;
1415 }
1416
1417 /*
1418 * If a foid is specified then find that node and append its
1419 * list. Otherwise walk the tree appending all the lists
1420 * to the sync list. We add to the end rather than the
1421 * beginning to ensure the create has happened.
1422 */
1423 t = &itxg->itxg_itxs->i_async_tree;
1424 if (foid != 0) {
1425 ian = avl_find(t, &foid, &where);
1426 if (ian != NULL) {
1427 list_move_tail(&itxg->itxg_itxs->i_sync_list,
1428 &ian->ia_list);
1429 }
1430 } else {
1431 void *cookie = NULL;
1432
1433 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) {
1434 list_move_tail(&itxg->itxg_itxs->i_sync_list,
1435 &ian->ia_list);
1436 list_destroy(&ian->ia_list);
1437 kmem_free(ian, sizeof (itx_async_node_t));
1438 }
1439 }
1440 mutex_exit(&itxg->itxg_lock);
1441 }
1442 }
1443
1444 static void
1445 zil_commit_writer(zilog_t *zilog)
1446 {
1447 uint64_t txg;
1448 itx_t *itx;
1449 lwb_t *lwb;
1450 spa_t *spa = zilog->zl_spa;
1451 int error = 0;
1452
1453 ASSERT(zilog->zl_root_zio == NULL);
1454
1455 mutex_exit(&zilog->zl_lock);
1456
1457 zil_get_commit_list(zilog);
1458
1459 /*
1460 * Return if there's nothing to commit before we dirty the fs by
1461 * calling zil_create().
1462 */
1463 if (list_head(&zilog->zl_itx_commit_list) == NULL) {
1464 mutex_enter(&zilog->zl_lock);
1465 return;
1466 }
1467
1468 if (zilog->zl_suspend) {
1469 lwb = NULL;
1470 } else {
1471 lwb = list_tail(&zilog->zl_lwb_list);
1472 if (lwb == NULL)
1473 lwb = zil_create(zilog);
1474 }
1475
1476 DTRACE_PROBE1(zil__cw1, zilog_t *, zilog);
1477 while (itx = list_head(&zilog->zl_itx_commit_list)) {
1478 txg = itx->itx_lr.lrc_txg;
1479 ASSERT(txg);
1480
1481 if (txg > spa_last_synced_txg(spa) || txg > spa_freeze_txg(spa))
1482 lwb = zil_lwb_commit(zilog, itx, lwb);
1483 list_remove(&zilog->zl_itx_commit_list, itx);
1484 kmem_free(itx, offsetof(itx_t, itx_lr)
1485 + itx->itx_lr.lrc_reclen);
1486 }
1487 DTRACE_PROBE1(zil__cw2, zilog_t *, zilog);
1488
1489 /* write the last block out */
1490 if (lwb != NULL && lwb->lwb_zio != NULL)
1491 lwb = zil_lwb_write_start(zilog, lwb);
1492
1493 zilog->zl_cur_used = 0;
1494
1495 /*
1496 * Wait if necessary for the log blocks to be on stable storage.
1497 */
1498 if (zilog->zl_root_zio) {
1499 error = zio_wait(zilog->zl_root_zio);
1500 zilog->zl_root_zio = NULL;
1501 zil_flush_vdevs(zilog);
1502 }
1503
1504 if (error || lwb == NULL)
1505 txg_wait_synced(zilog->zl_dmu_pool, 0);
1506
1507 mutex_enter(&zilog->zl_lock);
1508
1509 /*
1510 * Remember the highest committed log sequence number for ztest.
1511 * We only update this value when all the log writes succeeded,
1512 * because ztest wants to ASSERT that it got the whole log chain.
1513 */
1514 if (error == 0 && lwb != NULL)
1515 zilog->zl_commit_lr_seq = zilog->zl_lr_seq;
1516 }
1517
1518 /*
1519 * Commit zfs transactions to stable storage.
1520 * If foid is 0 push out all transactions, otherwise push only those
1521 * for that object or might reference that object.
1522 *
1523 * itxs are committed in batches. In a heavily stressed zil there will be
1524 * a commit writer thread who is writing out a bunch of itxs to the log
1525 * for a set of committing threads (cthreads) in the same batch as the writer.
1526 * Those cthreads are all waiting on the same cv for that batch.
1527 *
1528 * There will also be a different and growing batch of threads that are
1529 * waiting to commit (qthreads). When the committing batch completes
1530 * a transition occurs such that the cthreads exit and the qthreads become
1531 * cthreads. One of the new cthreads becomes the writer thread for the
1532 * batch. Any new threads arriving become new qthreads.
1533 *
1534 * Only 2 condition variables are needed and there's no transition
1535 * between the two cvs needed. They just flip-flop between qthreads
1536 * and cthreads.
1537 *
1538 * Using this scheme we can efficiently wakeup up only those threads
1539 * that have been committed.
1540 */
1541 void
1542 zil_commit(zilog_t *zilog, uint64_t foid)
1543 {
1544 uint64_t mybatch;
1545
1546 if (zilog->zl_sync == ZFS_SYNC_DISABLED)
1547 return;
1548
1549 /* move the async itxs for the foid to the sync queues */
1550 zil_async_to_sync(zilog, foid);
1551
1552 mutex_enter(&zilog->zl_lock);
1553 mybatch = zilog->zl_next_batch;
1554 while (zilog->zl_writer) {
1555 cv_wait(&zilog->zl_cv_batch[mybatch & 1], &zilog->zl_lock);
1556 if (mybatch <= zilog->zl_com_batch) {
1557 mutex_exit(&zilog->zl_lock);
1558 return;
1559 }
1560 }
1561
1562 zilog->zl_next_batch++;
1563 zilog->zl_writer = B_TRUE;
1564 zil_commit_writer(zilog);
1565 zilog->zl_com_batch = mybatch;
1566 zilog->zl_writer = B_FALSE;
1567 mutex_exit(&zilog->zl_lock);
1568
1569 /* wake up one thread to become the next writer */
1570 cv_signal(&zilog->zl_cv_batch[(mybatch+1) & 1]);
1571
1572 /* wake up all threads waiting for this batch to be committed */
1573 cv_broadcast(&zilog->zl_cv_batch[mybatch & 1]);
1574 }
1575
1576 /*
1577 * Called in syncing context to free committed log blocks and update log header.
1578 */
1579 void
1580 zil_sync(zilog_t *zilog, dmu_tx_t *tx)
1581 {
1582 zil_header_t *zh = zil_header_in_syncing_context(zilog);
1583 uint64_t txg = dmu_tx_get_txg(tx);
1584 spa_t *spa = zilog->zl_spa;
1585 uint64_t *replayed_seq = &zilog->zl_replayed_seq[txg & TXG_MASK];
1586 lwb_t *lwb;
1587
1588 /*
1589 * We don't zero out zl_destroy_txg, so make sure we don't try
1590 * to destroy it twice.
1591 */
1592 if (spa_sync_pass(spa) != 1)
1593 return;
1594
1595 mutex_enter(&zilog->zl_lock);
1596
1597 ASSERT(zilog->zl_stop_sync == 0);
1598
1599 if (*replayed_seq != 0) {
1600 ASSERT(zh->zh_replay_seq < *replayed_seq);
1601 zh->zh_replay_seq = *replayed_seq;
1602 *replayed_seq = 0;
1603 }
1604
1605 if (zilog->zl_destroy_txg == txg) {
1606 blkptr_t blk = zh->zh_log;
1607
1608 ASSERT(list_head(&zilog->zl_lwb_list) == NULL);
1609
1610 bzero(zh, sizeof (zil_header_t));
1611 bzero(zilog->zl_replayed_seq, sizeof (zilog->zl_replayed_seq));
1612
1613 if (zilog->zl_keep_first) {
1614 /*
1615 * If this block was part of log chain that couldn't
1616 * be claimed because a device was missing during
1617 * zil_claim(), but that device later returns,
1618 * then this block could erroneously appear valid.
1619 * To guard against this, assign a new GUID to the new
1620 * log chain so it doesn't matter what blk points to.
1621 */
1622 zil_init_log_chain(zilog, &blk);
1623 zh->zh_log = blk;
1624 }
1625 }
1626
1627 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) {
1628 zh->zh_log = lwb->lwb_blk;
1629 if (lwb->lwb_buf != NULL || lwb->lwb_max_txg > txg)
1630 break;
1631 list_remove(&zilog->zl_lwb_list, lwb);
1632 zio_free_zil(spa, txg, &lwb->lwb_blk);
1633 kmem_cache_free(zil_lwb_cache, lwb);
1634
1635 /*
1636 * If we don't have anything left in the lwb list then
1637 * we've had an allocation failure and we need to zero
1638 * out the zil_header blkptr so that we don't end
1639 * up freeing the same block twice.
1640 */
1641 if (list_head(&zilog->zl_lwb_list) == NULL)
1642 BP_ZERO(&zh->zh_log);
1643 }
1644 mutex_exit(&zilog->zl_lock);
1645 }
1646
1647 void
1648 zil_init(void)
1649 {
1650 zil_lwb_cache = kmem_cache_create("zil_lwb_cache",
1651 sizeof (struct lwb), 0, NULL, NULL, NULL, NULL, NULL, 0);
1652 }
1653
1654 void
1655 zil_fini(void)
1656 {
1657 kmem_cache_destroy(zil_lwb_cache);
1658 }
1659
1660 void
1661 zil_set_sync(zilog_t *zilog, uint64_t sync)
1662 {
1663 zilog->zl_sync = sync;
1664 }
1665
1666 void
1667 zil_set_logbias(zilog_t *zilog, uint64_t logbias)
1668 {
1669 zilog->zl_logbias = logbias;
1670 }
1671
1672 zilog_t *
1673 zil_alloc(objset_t *os, zil_header_t *zh_phys)
1674 {
1675 zilog_t *zilog;
1676
1677 zilog = kmem_zalloc(sizeof (zilog_t), KM_SLEEP);
1678
1679 zilog->zl_header = zh_phys;
1680 zilog->zl_os = os;
1681 zilog->zl_spa = dmu_objset_spa(os);
1682 zilog->zl_dmu_pool = dmu_objset_pool(os);
1683 zilog->zl_destroy_txg = TXG_INITIAL - 1;
1684 zilog->zl_logbias = dmu_objset_logbias(os);
1685 zilog->zl_sync = dmu_objset_syncprop(os);
1686 zilog->zl_next_batch = 1;
1687
1688 mutex_init(&zilog->zl_lock, NULL, MUTEX_DEFAULT, NULL);
1689
1690 for (int i = 0; i < TXG_SIZE; i++) {
1691 mutex_init(&zilog->zl_itxg[i].itxg_lock, NULL,
1692 MUTEX_DEFAULT, NULL);
1693 }
1694
1695 list_create(&zilog->zl_lwb_list, sizeof (lwb_t),
1696 offsetof(lwb_t, lwb_node));
1697
1698 list_create(&zilog->zl_itx_commit_list, sizeof (itx_t),
1699 offsetof(itx_t, itx_node));
1700
1701 mutex_init(&zilog->zl_vdev_lock, NULL, MUTEX_DEFAULT, NULL);
1702
1703 avl_create(&zilog->zl_vdev_tree, zil_vdev_compare,
1704 sizeof (zil_vdev_node_t), offsetof(zil_vdev_node_t, zv_node));
1705
1706 cv_init(&zilog->zl_cv_writer, NULL, CV_DEFAULT, NULL);
1707 cv_init(&zilog->zl_cv_suspend, NULL, CV_DEFAULT, NULL);
1708 cv_init(&zilog->zl_cv_batch[0], NULL, CV_DEFAULT, NULL);
1709 cv_init(&zilog->zl_cv_batch[1], NULL, CV_DEFAULT, NULL);
1710
1711 return (zilog);
1712 }
1713
1714 void
1715 zil_free(zilog_t *zilog)
1716 {
1717 zilog->zl_stop_sync = 1;
1718
1719 ASSERT0(zilog->zl_suspend);
1720 ASSERT0(zilog->zl_suspending);
1721
1722 ASSERT(list_is_empty(&zilog->zl_lwb_list));
1723 list_destroy(&zilog->zl_lwb_list);
1724
1725 avl_destroy(&zilog->zl_vdev_tree);
1726 mutex_destroy(&zilog->zl_vdev_lock);
1727
1728 ASSERT(list_is_empty(&zilog->zl_itx_commit_list));
1729 list_destroy(&zilog->zl_itx_commit_list);
1730
1731 for (int i = 0; i < TXG_SIZE; i++) {
1732 /*
1733 * It's possible for an itx to be generated that doesn't dirty
1734 * a txg (e.g. ztest TX_TRUNCATE). So there's no zil_clean()
1735 * callback to remove the entry. We remove those here.
1736 *
1737 * Also free up the ziltest itxs.
1738 */
1739 if (zilog->zl_itxg[i].itxg_itxs)
1740 zil_itxg_clean(zilog->zl_itxg[i].itxg_itxs);
1741 mutex_destroy(&zilog->zl_itxg[i].itxg_lock);
1742 }
1743
1744 mutex_destroy(&zilog->zl_lock);
1745
1746 cv_destroy(&zilog->zl_cv_writer);
1747 cv_destroy(&zilog->zl_cv_suspend);
1748 cv_destroy(&zilog->zl_cv_batch[0]);
1749 cv_destroy(&zilog->zl_cv_batch[1]);
1750
1751 kmem_free(zilog, sizeof (zilog_t));
1752 }
1753
1754 /*
1755 * Open an intent log.
1756 */
1757 zilog_t *
1758 zil_open(objset_t *os, zil_get_data_t *get_data)
1759 {
1760 zilog_t *zilog = dmu_objset_zil(os);
1761
1762 ASSERT(zilog->zl_clean_taskq == NULL);
1763 ASSERT(zilog->zl_get_data == NULL);
1764 ASSERT(list_is_empty(&zilog->zl_lwb_list));
1765
1766 zilog->zl_get_data = get_data;
1767 zilog->zl_clean_taskq = taskq_create("zil_clean", 1, minclsyspri,
1768 2, 2, TASKQ_PREPOPULATE);
1769
1770 return (zilog);
1771 }
1772
1773 /*
1774 * Close an intent log.
1775 */
1776 void
1777 zil_close(zilog_t *zilog)
1778 {
1779 lwb_t *lwb;
1780 uint64_t txg = 0;
1781
1782 zil_commit(zilog, 0); /* commit all itx */
1783
1784 /*
1785 * The lwb_max_txg for the stubby lwb will reflect the last activity
1786 * for the zil. After a txg_wait_synced() on the txg we know all the
1787 * callbacks have occurred that may clean the zil. Only then can we
1788 * destroy the zl_clean_taskq.
1789 */
1790 mutex_enter(&zilog->zl_lock);
1791 lwb = list_tail(&zilog->zl_lwb_list);
1792 if (lwb != NULL)
1793 txg = lwb->lwb_max_txg;
1794 mutex_exit(&zilog->zl_lock);
1795 if (txg)
1796 txg_wait_synced(zilog->zl_dmu_pool, txg);
1797 ASSERT(!zilog_is_dirty(zilog));
1798
1799 taskq_destroy(zilog->zl_clean_taskq);
1800 zilog->zl_clean_taskq = NULL;
1801 zilog->zl_get_data = NULL;
1802
1803 /*
1804 * We should have only one LWB left on the list; remove it now.
1805 */
1806 mutex_enter(&zilog->zl_lock);
1807 lwb = list_head(&zilog->zl_lwb_list);
1808 if (lwb != NULL) {
1809 ASSERT(lwb == list_tail(&zilog->zl_lwb_list));
1810 list_remove(&zilog->zl_lwb_list, lwb);
1811 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
1812 kmem_cache_free(zil_lwb_cache, lwb);
1813 }
1814 mutex_exit(&zilog->zl_lock);
1815 }
1816
1817 static char *suspend_tag = "zil suspending";
1818
1819 /*
1820 * Suspend an intent log. While in suspended mode, we still honor
1821 * synchronous semantics, but we rely on txg_wait_synced() to do it.
1822 * On old version pools, we suspend the log briefly when taking a
1823 * snapshot so that it will have an empty intent log.
1824 *
1825 * Long holds are not really intended to be used the way we do here --
1826 * held for such a short time. A concurrent caller of dsl_dataset_long_held()
1827 * could fail. Therefore we take pains to only put a long hold if it is
1828 * actually necessary. Fortunately, it will only be necessary if the
1829 * objset is currently mounted (or the ZVOL equivalent). In that case it
1830 * will already have a long hold, so we are not really making things any worse.
1831 *
1832 * Ideally, we would locate the existing long-holder (i.e. the zfsvfs_t or
1833 * zvol_state_t), and use their mechanism to prevent their hold from being
1834 * dropped (e.g. VFS_HOLD()). However, that would be even more pain for
1835 * very little gain.
1836 *
1837 * if cookiep == NULL, this does both the suspend & resume.
1838 * Otherwise, it returns with the dataset "long held", and the cookie
1839 * should be passed into zil_resume().
1840 */
1841 int
1842 zil_suspend(const char *osname, void **cookiep)
1843 {
1844 objset_t *os;
1845 zilog_t *zilog;
1846 const zil_header_t *zh;
1847 int error;
1848
1849 error = dmu_objset_hold(osname, suspend_tag, &os);
1850 if (error != 0)
1851 return (error);
1852 zilog = dmu_objset_zil(os);
1853
1854 mutex_enter(&zilog->zl_lock);
1855 zh = zilog->zl_header;
1856
1857 if (zh->zh_flags & ZIL_REPLAY_NEEDED) { /* unplayed log */
1858 mutex_exit(&zilog->zl_lock);
1859 dmu_objset_rele(os, suspend_tag);
1860 return (SET_ERROR(EBUSY));
1861 }
1862
1863 /*
1864 * Don't put a long hold in the cases where we can avoid it. This
1865 * is when there is no cookie so we are doing a suspend & resume
1866 * (i.e. called from zil_vdev_offline()), and there's nothing to do
1867 * for the suspend because it's already suspended, or there's no ZIL.
1868 */
1869 if (cookiep == NULL && !zilog->zl_suspending &&
1870 (zilog->zl_suspend > 0 || BP_IS_HOLE(&zh->zh_log))) {
1871 mutex_exit(&zilog->zl_lock);
1872 dmu_objset_rele(os, suspend_tag);
1873 return (0);
1874 }
1875
1876 dsl_dataset_long_hold(dmu_objset_ds(os), suspend_tag);
1877 dsl_pool_rele(dmu_objset_pool(os), suspend_tag);
1878
1879 zilog->zl_suspend++;
1880
1881 if (zilog->zl_suspend > 1) {
1882 /*
1883 * Someone else is already suspending it.
1884 * Just wait for them to finish.
1885 */
1886
1887 while (zilog->zl_suspending)
1888 cv_wait(&zilog->zl_cv_suspend, &zilog->zl_lock);
1889 mutex_exit(&zilog->zl_lock);
1890
1891 if (cookiep == NULL)
1892 zil_resume(os);
1893 else
1894 *cookiep = os;
1895 return (0);
1896 }
1897
1898 /*
1899 * If there is no pointer to an on-disk block, this ZIL must not
1900 * be active (e.g. filesystem not mounted), so there's nothing
1901 * to clean up.
1902 */
1903 if (BP_IS_HOLE(&zh->zh_log)) {
1904 ASSERT(cookiep != NULL); /* fast path already handled */
1905
1906 *cookiep = os;
1907 mutex_exit(&zilog->zl_lock);
1908 return (0);
1909 }
1910
1911 zilog->zl_suspending = B_TRUE;
1912 mutex_exit(&zilog->zl_lock);
1913
1914 zil_commit(zilog, 0);
1915
1916 zil_destroy(zilog, B_FALSE);
1917
1918 mutex_enter(&zilog->zl_lock);
1919 zilog->zl_suspending = B_FALSE;
1920 cv_broadcast(&zilog->zl_cv_suspend);
1921 mutex_exit(&zilog->zl_lock);
1922
1923 if (cookiep == NULL)
1924 zil_resume(os);
1925 else
1926 *cookiep = os;
1927 return (0);
1928 }
1929
1930 void
1931 zil_resume(void *cookie)
1932 {
1933 objset_t *os = cookie;
1934 zilog_t *zilog = dmu_objset_zil(os);
1935
1936 mutex_enter(&zilog->zl_lock);
1937 ASSERT(zilog->zl_suspend != 0);
1938 zilog->zl_suspend--;
1939 mutex_exit(&zilog->zl_lock);
1940 dsl_dataset_long_rele(dmu_objset_ds(os), suspend_tag);
1941 dsl_dataset_rele(dmu_objset_ds(os), suspend_tag);
1942 }
1943
1944 typedef struct zil_replay_arg {
1945 zil_replay_func_t **zr_replay;
1946 void *zr_arg;
1947 boolean_t zr_byteswap;
1948 char *zr_lr;
1949 } zil_replay_arg_t;
1950
1951 static int
1952 zil_replay_error(zilog_t *zilog, lr_t *lr, int error)
1953 {
1954 char name[MAXNAMELEN];
1955
1956 zilog->zl_replaying_seq--; /* didn't actually replay this one */
1957
1958 dmu_objset_name(zilog->zl_os, name);
1959
1960 cmn_err(CE_WARN, "ZFS replay transaction error %d, "
1961 "dataset %s, seq 0x%llx, txtype %llu %s\n", error, name,
1962 (u_longlong_t)lr->lrc_seq,
1963 (u_longlong_t)(lr->lrc_txtype & ~TX_CI),
1964 (lr->lrc_txtype & TX_CI) ? "CI" : "");
1965
1966 return (error);
1967 }
1968
1969 static int
1970 zil_replay_log_record(zilog_t *zilog, lr_t *lr, void *zra, uint64_t claim_txg)
1971 {
1972 zil_replay_arg_t *zr = zra;
1973 const zil_header_t *zh = zilog->zl_header;
1974 uint64_t reclen = lr->lrc_reclen;
1975 uint64_t txtype = lr->lrc_txtype;
1976 int error = 0;
1977
1978 zilog->zl_replaying_seq = lr->lrc_seq;
1979
1980 if (lr->lrc_seq <= zh->zh_replay_seq) /* already replayed */
1981 return (0);
1982
1983 if (lr->lrc_txg < claim_txg) /* already committed */
1984 return (0);
1985
1986 /* Strip case-insensitive bit, still present in log record */
1987 txtype &= ~TX_CI;
1988
1989 if (txtype == 0 || txtype >= TX_MAX_TYPE)
1990 return (zil_replay_error(zilog, lr, EINVAL));
1991
1992 /*
1993 * If this record type can be logged out of order, the object
1994 * (lr_foid) may no longer exist. That's legitimate, not an error.
1995 */
1996 if (TX_OOO(txtype)) {
1997 error = dmu_object_info(zilog->zl_os,
1998 ((lr_ooo_t *)lr)->lr_foid, NULL);
1999 if (error == ENOENT || error == EEXIST)
2000 return (0);
2001 }
2002
2003 /*
2004 * Make a copy of the data so we can revise and extend it.
2005 */
2006 bcopy(lr, zr->zr_lr, reclen);
2007
2008 /*
2009 * If this is a TX_WRITE with a blkptr, suck in the data.
2010 */
2011 if (txtype == TX_WRITE && reclen == sizeof (lr_write_t)) {
2012 error = zil_read_log_data(zilog, (lr_write_t *)lr,
2013 zr->zr_lr + reclen);
2014 if (error != 0)
2015 return (zil_replay_error(zilog, lr, error));
2016 }
2017
2018 /*
2019 * The log block containing this lr may have been byteswapped
2020 * so that we can easily examine common fields like lrc_txtype.
2021 * However, the log is a mix of different record types, and only the
2022 * replay vectors know how to byteswap their records. Therefore, if
2023 * the lr was byteswapped, undo it before invoking the replay vector.
2024 */
2025 if (zr->zr_byteswap)
2026 byteswap_uint64_array(zr->zr_lr, reclen);
2027
2028 /*
2029 * We must now do two things atomically: replay this log record,
2030 * and update the log header sequence number to reflect the fact that
2031 * we did so. At the end of each replay function the sequence number
2032 * is updated if we are in replay mode.
2033 */
2034 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, zr->zr_byteswap);
2035 if (error != 0) {
2036 /*
2037 * The DMU's dnode layer doesn't see removes until the txg
2038 * commits, so a subsequent claim can spuriously fail with
2039 * EEXIST. So if we receive any error we try syncing out
2040 * any removes then retry the transaction. Note that we
2041 * specify B_FALSE for byteswap now, so we don't do it twice.
2042 */
2043 txg_wait_synced(spa_get_dsl(zilog->zl_spa), 0);
2044 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, B_FALSE);
2045 if (error != 0)
2046 return (zil_replay_error(zilog, lr, error));
2047 }
2048 return (0);
2049 }
2050
2051 /* ARGSUSED */
2052 static int
2053 zil_incr_blks(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg)
2054 {
2055 zilog->zl_replay_blks++;
2056
2057 return (0);
2058 }
2059
2060 /*
2061 * If this dataset has a non-empty intent log, replay it and destroy it.
2062 */
2063 void
2064 zil_replay(objset_t *os, void *arg, zil_replay_func_t *replay_func[TX_MAX_TYPE])
2065 {
2066 zilog_t *zilog = dmu_objset_zil(os);
2067 const zil_header_t *zh = zilog->zl_header;
2068 zil_replay_arg_t zr;
2069
2070 if ((zh->zh_flags & ZIL_REPLAY_NEEDED) == 0) {
2071 zil_destroy(zilog, B_TRUE);
2072 return;
2073 }
2074
2075 zr.zr_replay = replay_func;
2076 zr.zr_arg = arg;
2077 zr.zr_byteswap = BP_SHOULD_BYTESWAP(&zh->zh_log);
2078 zr.zr_lr = kmem_alloc(2 * SPA_MAXBLOCKSIZE, KM_SLEEP);
2079
2080 /*
2081 * Wait for in-progress removes to sync before starting replay.
2082 */
2083 txg_wait_synced(zilog->zl_dmu_pool, 0);
2084
2085 zilog->zl_replay = B_TRUE;
2086 zilog->zl_replay_time = ddi_get_lbolt();
2087 ASSERT(zilog->zl_replay_blks == 0);
2088 (void) zil_parse(zilog, zil_incr_blks, zil_replay_log_record, &zr,
2089 zh->zh_claim_txg);
2090 kmem_free(zr.zr_lr, 2 * SPA_MAXBLOCKSIZE);
2091
2092 zil_destroy(zilog, B_FALSE);
2093 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg);
2094 zilog->zl_replay = B_FALSE;
2095 }
2096
2097 boolean_t
2098 zil_replaying(zilog_t *zilog, dmu_tx_t *tx)
2099 {
2100 if (zilog->zl_sync == ZFS_SYNC_DISABLED)
2101 return (B_TRUE);
2102
2103 if (zilog->zl_replay) {
2104 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
2105 zilog->zl_replayed_seq[dmu_tx_get_txg(tx) & TXG_MASK] =
2106 zilog->zl_replaying_seq;
2107 return (B_TRUE);
2108 }
2109
2110 return (B_FALSE);
2111 }
2112
2113 /* ARGSUSED */
2114 int
2115 zil_vdev_offline(const char *osname, void *arg)
2116 {
2117 int error;
2118
2119 error = zil_suspend(osname, NULL);
2120 if (error != 0)
2121 return (SET_ERROR(EEXIST));
2122 return (0);
2123 }