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 * This global ZIL switch affects all pools
70 */
71 int zil_replay_disable = 0; /* disable intent logging replay */
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 = BP_IDENTITY(bp);
141 zil_bp_node_t *zn;
142 avl_index_t where;
143
144 if (avl_find(t, dva, &where) != NULL)
145 return (SET_ERROR(EEXIST));
146
147 zn = kmem_alloc(sizeof (zil_bp_node_t), KM_SLEEP);
148 zn->zn_dva = *dva;
149 avl_insert(t, zn, where);
150
151 return (0);
152 }
153
154 static zil_header_t *
155 zil_header_in_syncing_context(zilog_t *zilog)
156 {
157 return ((zil_header_t *)zilog->zl_header);
158 }
159
160 static void
161 zil_init_log_chain(zilog_t *zilog, blkptr_t *bp)
162 {
163 zio_cksum_t *zc = &bp->blk_cksum;
164
165 zc->zc_word[ZIL_ZC_GUID_0] = spa_get_random(-1ULL);
166 zc->zc_word[ZIL_ZC_GUID_1] = spa_get_random(-1ULL);
167 zc->zc_word[ZIL_ZC_OBJSET] = dmu_objset_id(zilog->zl_os);
168 zc->zc_word[ZIL_ZC_SEQ] = 1ULL;
169 }
170
171 /*
172 * Read a log block and make sure it's valid.
173 */
174 static int
175 zil_read_log_block(zilog_t *zilog, const blkptr_t *bp, blkptr_t *nbp, void *dst,
176 char **end)
177 {
178 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL;
179 uint32_t aflags = ARC_WAIT;
180 arc_buf_t *abuf = NULL;
181 zbookmark_t zb;
182 int error;
183
184 if (zilog->zl_header->zh_claim_txg == 0)
185 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB;
186
187 if (!(zilog->zl_header->zh_flags & ZIL_CLAIM_LR_SEQ_VALID))
188 zio_flags |= ZIO_FLAG_SPECULATIVE;
189
190 SET_BOOKMARK(&zb, bp->blk_cksum.zc_word[ZIL_ZC_OBJSET],
191 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]);
192
193 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf,
194 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb);
195
196 if (error == 0) {
197 zio_cksum_t cksum = bp->blk_cksum;
198
199 /*
200 * Validate the checksummed log block.
201 *
202 * Sequence numbers should be... sequential. The checksum
203 * verifier for the next block should be bp's checksum plus 1.
204 *
205 * Also check the log chain linkage and size used.
206 */
207 cksum.zc_word[ZIL_ZC_SEQ]++;
208
209 if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) {
210 zil_chain_t *zilc = abuf->b_data;
211 char *lr = (char *)(zilc + 1);
212 uint64_t len = zilc->zc_nused - sizeof (zil_chain_t);
213
214 if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum,
215 sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk)) {
216 error = SET_ERROR(ECKSUM);
217 } else {
218 bcopy(lr, dst, len);
219 *end = (char *)dst + len;
220 *nbp = zilc->zc_next_blk;
221 }
222 } else {
223 char *lr = abuf->b_data;
224 uint64_t size = BP_GET_LSIZE(bp);
225 zil_chain_t *zilc = (zil_chain_t *)(lr + size) - 1;
226
227 if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum,
228 sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk) ||
229 (zilc->zc_nused > (size - sizeof (*zilc)))) {
230 error = SET_ERROR(ECKSUM);
231 } else {
232 bcopy(lr, dst, zilc->zc_nused);
233 *end = (char *)dst + zilc->zc_nused;
234 *nbp = zilc->zc_next_blk;
235 }
236 }
237
238 VERIFY(arc_buf_remove_ref(abuf, &abuf));
239 }
240
241 return (error);
242 }
243
244 /*
245 * Read a TX_WRITE log data block.
246 */
247 static int
248 zil_read_log_data(zilog_t *zilog, const lr_write_t *lr, void *wbuf)
249 {
250 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL;
251 const blkptr_t *bp = &lr->lr_blkptr;
252 uint32_t aflags = ARC_WAIT;
253 arc_buf_t *abuf = NULL;
254 zbookmark_t zb;
255 int error;
256
257 if (BP_IS_HOLE(bp)) {
258 if (wbuf != NULL)
259 bzero(wbuf, MAX(BP_GET_LSIZE(bp), lr->lr_length));
260 return (0);
261 }
262
263 if (zilog->zl_header->zh_claim_txg == 0)
264 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB;
265
266 SET_BOOKMARK(&zb, dmu_objset_id(zilog->zl_os), lr->lr_foid,
267 ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp));
268
269 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf,
270 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb);
271
272 if (error == 0) {
273 if (wbuf != NULL)
274 bcopy(abuf->b_data, wbuf, arc_buf_size(abuf));
275 (void) arc_buf_remove_ref(abuf, &abuf);
276 }
277
278 return (error);
279 }
280
281 /*
282 * Parse the intent log, and call parse_func for each valid record within.
283 */
284 int
285 zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func,
286 zil_parse_lr_func_t *parse_lr_func, void *arg, uint64_t txg)
287 {
288 const zil_header_t *zh = zilog->zl_header;
289 boolean_t claimed = !!zh->zh_claim_txg;
290 uint64_t claim_blk_seq = claimed ? zh->zh_claim_blk_seq : UINT64_MAX;
291 uint64_t claim_lr_seq = claimed ? zh->zh_claim_lr_seq : UINT64_MAX;
292 uint64_t max_blk_seq = 0;
293 uint64_t max_lr_seq = 0;
294 uint64_t blk_count = 0;
295 uint64_t lr_count = 0;
296 blkptr_t blk, next_blk;
297 char *lrbuf, *lrp;
298 int error = 0;
299
300 /*
301 * Old logs didn't record the maximum zh_claim_lr_seq.
302 */
303 if (!(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID))
304 claim_lr_seq = UINT64_MAX;
305
306 /*
307 * Starting at the block pointed to by zh_log we read the log chain.
308 * For each block in the chain we strongly check that block to
309 * ensure its validity. We stop when an invalid block is found.
310 * For each block pointer in the chain we call parse_blk_func().
311 * For each record in each valid block we call parse_lr_func().
312 * If the log has been claimed, stop if we encounter a sequence
313 * number greater than the highest claimed sequence number.
314 */
315 lrbuf = zio_buf_alloc(SPA_MAXBLOCKSIZE);
316 zil_bp_tree_init(zilog);
317
318 for (blk = zh->zh_log; !BP_IS_HOLE(&blk); blk = next_blk) {
319 uint64_t blk_seq = blk.blk_cksum.zc_word[ZIL_ZC_SEQ];
320 int reclen;
321 char *end;
322
323 if (blk_seq > claim_blk_seq)
324 break;
325 if ((error = parse_blk_func(zilog, &blk, arg, txg)) != 0)
326 break;
327 ASSERT3U(max_blk_seq, <, blk_seq);
328 max_blk_seq = blk_seq;
329 blk_count++;
330
331 if (max_lr_seq == claim_lr_seq && max_blk_seq == claim_blk_seq)
332 break;
333
334 error = zil_read_log_block(zilog, &blk, &next_blk, lrbuf, &end);
335 if (error != 0)
336 break;
337
338 for (lrp = lrbuf; lrp < end; lrp += reclen) {
339 lr_t *lr = (lr_t *)lrp;
340 reclen = lr->lrc_reclen;
341 ASSERT3U(reclen, >=, sizeof (lr_t));
342 if (lr->lrc_seq > claim_lr_seq)
343 goto done;
344 if ((error = parse_lr_func(zilog, lr, arg, txg)) != 0)
345 goto done;
346 ASSERT3U(max_lr_seq, <, lr->lrc_seq);
347 max_lr_seq = lr->lrc_seq;
348 lr_count++;
349 }
350 }
351 done:
352 zilog->zl_parse_error = error;
353 zilog->zl_parse_blk_seq = max_blk_seq;
354 zilog->zl_parse_lr_seq = max_lr_seq;
355 zilog->zl_parse_blk_count = blk_count;
356 zilog->zl_parse_lr_count = lr_count;
357
358 ASSERT(!claimed || !(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID) ||
359 (max_blk_seq == claim_blk_seq && max_lr_seq == claim_lr_seq));
360
361 zil_bp_tree_fini(zilog);
362 zio_buf_free(lrbuf, SPA_MAXBLOCKSIZE);
363
364 return (error);
365 }
366
367 static int
368 zil_claim_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t first_txg)
369 {
370 /*
371 * Claim log block if not already committed and not already claimed.
372 * If tx == NULL, just verify that the block is claimable.
373 */
374 if (bp->blk_birth < first_txg || zil_bp_tree_add(zilog, bp) != 0)
375 return (0);
376
377 return (zio_wait(zio_claim(NULL, zilog->zl_spa,
378 tx == NULL ? 0 : first_txg, bp, spa_claim_notify, NULL,
379 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB)));
380 }
381
382 static int
383 zil_claim_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t first_txg)
384 {
385 lr_write_t *lr = (lr_write_t *)lrc;
386 int error;
387
388 if (lrc->lrc_txtype != TX_WRITE)
389 return (0);
390
391 /*
392 * If the block is not readable, don't claim it. This can happen
393 * in normal operation when a log block is written to disk before
394 * some of the dmu_sync() blocks it points to. In this case, the
395 * transaction cannot have been committed to anyone (we would have
396 * waited for all writes to be stable first), so it is semantically
397 * correct to declare this the end of the log.
398 */
399 if (lr->lr_blkptr.blk_birth >= first_txg &&
400 (error = zil_read_log_data(zilog, lr, NULL)) != 0)
401 return (error);
402 return (zil_claim_log_block(zilog, &lr->lr_blkptr, tx, first_txg));
403 }
404
405 /* ARGSUSED */
406 static int
407 zil_free_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t claim_txg)
408 {
409 zio_free_zil(zilog->zl_spa, dmu_tx_get_txg(tx), bp);
410
411 return (0);
412 }
413
414 static int
415 zil_free_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t claim_txg)
416 {
417 lr_write_t *lr = (lr_write_t *)lrc;
418 blkptr_t *bp = &lr->lr_blkptr;
419
420 /*
421 * If we previously claimed it, we need to free it.
422 */
423 if (claim_txg != 0 && lrc->lrc_txtype == TX_WRITE &&
424 bp->blk_birth >= claim_txg && zil_bp_tree_add(zilog, bp) == 0)
425 zio_free(zilog->zl_spa, dmu_tx_get_txg(tx), bp);
426
427 return (0);
428 }
429
430 static lwb_t *
431 zil_alloc_lwb(zilog_t *zilog, blkptr_t *bp, uint64_t txg)
432 {
433 lwb_t *lwb;
434
435 lwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP);
436 lwb->lwb_zilog = zilog;
437 lwb->lwb_blk = *bp;
438 lwb->lwb_buf = zio_buf_alloc(BP_GET_LSIZE(bp));
439 lwb->lwb_max_txg = txg;
440 lwb->lwb_zio = NULL;
441 lwb->lwb_tx = NULL;
442 if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) {
443 lwb->lwb_nused = sizeof (zil_chain_t);
444 lwb->lwb_sz = BP_GET_LSIZE(bp);
445 } else {
446 lwb->lwb_nused = 0;
447 lwb->lwb_sz = BP_GET_LSIZE(bp) - sizeof (zil_chain_t);
448 }
449
450 mutex_enter(&zilog->zl_lock);
451 list_insert_tail(&zilog->zl_lwb_list, lwb);
452 mutex_exit(&zilog->zl_lock);
453
454 return (lwb);
455 }
456
457 /*
458 * Called when we create in-memory log transactions so that we know
459 * to cleanup the itxs at the end of spa_sync().
460 */
461 void
462 zilog_dirty(zilog_t *zilog, uint64_t txg)
463 {
464 dsl_pool_t *dp = zilog->zl_dmu_pool;
465 dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os);
466
467 if (dsl_dataset_is_snapshot(ds))
468 panic("dirtying snapshot!");
469
470 if (txg_list_add(&dp->dp_dirty_zilogs, zilog, txg)) {
471 /* up the hold count until we can be written out */
472 dmu_buf_add_ref(ds->ds_dbuf, zilog);
473 }
474 }
475
476 boolean_t
477 zilog_is_dirty(zilog_t *zilog)
478 {
479 dsl_pool_t *dp = zilog->zl_dmu_pool;
480
481 for (int t = 0; t < TXG_SIZE; t++) {
482 if (txg_list_member(&dp->dp_dirty_zilogs, zilog, t))
483 return (B_TRUE);
484 }
485 return (B_FALSE);
486 }
487
488 /*
489 * Create an on-disk intent log.
490 */
491 static lwb_t *
492 zil_create(zilog_t *zilog)
493 {
494 const zil_header_t *zh = zilog->zl_header;
495 lwb_t *lwb = NULL;
496 uint64_t txg = 0;
497 dmu_tx_t *tx = NULL;
498 blkptr_t blk;
499 int error = 0;
500
501 /*
502 * Wait for any previous destroy to complete.
503 */
504 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg);
505
506 ASSERT(zh->zh_claim_txg == 0);
507 ASSERT(zh->zh_replay_seq == 0);
508
509 blk = zh->zh_log;
510
511 /*
512 * Allocate an initial log block if:
513 * - there isn't one already
514 * - the existing block is the wrong endianess
515 */
516 if (BP_IS_HOLE(&blk) || BP_SHOULD_BYTESWAP(&blk)) {
517 tx = dmu_tx_create(zilog->zl_os);
518 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0);
519 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
520 txg = dmu_tx_get_txg(tx);
521
522 if (!BP_IS_HOLE(&blk)) {
523 zio_free_zil(zilog->zl_spa, txg, &blk);
524 BP_ZERO(&blk);
525 }
526
527 error = zio_alloc_zil(zilog->zl_spa, txg, &blk, NULL,
528 ZIL_MIN_BLKSZ, zilog->zl_logbias == ZFS_LOGBIAS_LATENCY);
529
530 if (error == 0)
531 zil_init_log_chain(zilog, &blk);
532 }
533
534 /*
535 * Allocate a log write buffer (lwb) for the first log block.
536 */
537 if (error == 0)
538 lwb = zil_alloc_lwb(zilog, &blk, txg);
539
540 /*
541 * If we just allocated the first log block, commit our transaction
542 * and wait for zil_sync() to stuff the block poiner into zh_log.
543 * (zh is part of the MOS, so we cannot modify it in open context.)
544 */
545 if (tx != NULL) {
546 dmu_tx_commit(tx);
547 txg_wait_synced(zilog->zl_dmu_pool, txg);
548 }
549
550 ASSERT(bcmp(&blk, &zh->zh_log, sizeof (blk)) == 0);
551
552 return (lwb);
553 }
554
555 /*
556 * In one tx, free all log blocks and clear the log header.
557 * If keep_first is set, then we're replaying a log with no content.
558 * We want to keep the first block, however, so that the first
559 * synchronous transaction doesn't require a txg_wait_synced()
560 * in zil_create(). We don't need to txg_wait_synced() here either
561 * when keep_first is set, because both zil_create() and zil_destroy()
562 * will wait for any in-progress destroys to complete.
563 */
564 void
565 zil_destroy(zilog_t *zilog, boolean_t keep_first)
566 {
567 const zil_header_t *zh = zilog->zl_header;
568 lwb_t *lwb;
569 dmu_tx_t *tx;
570 uint64_t txg;
571
572 /*
573 * Wait for any previous destroy to complete.
574 */
575 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg);
576
577 zilog->zl_old_header = *zh; /* debugging aid */
578
579 if (BP_IS_HOLE(&zh->zh_log))
580 return;
581
582 tx = dmu_tx_create(zilog->zl_os);
583 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0);
584 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
585 txg = dmu_tx_get_txg(tx);
586
587 mutex_enter(&zilog->zl_lock);
588
589 ASSERT3U(zilog->zl_destroy_txg, <, txg);
590 zilog->zl_destroy_txg = txg;
591 zilog->zl_keep_first = keep_first;
592
593 if (!list_is_empty(&zilog->zl_lwb_list)) {
594 ASSERT(zh->zh_claim_txg == 0);
595 VERIFY(!keep_first);
596 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) {
597 list_remove(&zilog->zl_lwb_list, lwb);
598 if (lwb->lwb_buf != NULL)
599 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
600 zio_free_zil(zilog->zl_spa, txg, &lwb->lwb_blk);
601 kmem_cache_free(zil_lwb_cache, lwb);
602 }
603 } else if (!keep_first) {
604 zil_destroy_sync(zilog, tx);
605 }
606 mutex_exit(&zilog->zl_lock);
607
608 dmu_tx_commit(tx);
609 }
610
611 void
612 zil_destroy_sync(zilog_t *zilog, dmu_tx_t *tx)
613 {
614 ASSERT(list_is_empty(&zilog->zl_lwb_list));
615 (void) zil_parse(zilog, zil_free_log_block,
616 zil_free_log_record, tx, zilog->zl_header->zh_claim_txg);
617 }
618
619 int
620 zil_claim(const char *osname, void *txarg)
621 {
622 dmu_tx_t *tx = txarg;
623 uint64_t first_txg = dmu_tx_get_txg(tx);
624 zilog_t *zilog;
625 zil_header_t *zh;
626 objset_t *os;
627 int error;
628
629 error = dmu_objset_own(osname, DMU_OST_ANY, B_FALSE, FTAG, &os);
630 if (error != 0) {
631 cmn_err(CE_WARN, "can't open objset for %s", osname);
632 return (0);
633 }
634
635 zilog = dmu_objset_zil(os);
636 zh = zil_header_in_syncing_context(zilog);
637
638 if (spa_get_log_state(zilog->zl_spa) == SPA_LOG_CLEAR) {
639 if (!BP_IS_HOLE(&zh->zh_log))
640 zio_free_zil(zilog->zl_spa, first_txg, &zh->zh_log);
641 BP_ZERO(&zh->zh_log);
642 dsl_dataset_dirty(dmu_objset_ds(os), tx);
643 dmu_objset_disown(os, FTAG);
644 return (0);
645 }
646
647 /*
648 * Claim all log blocks if we haven't already done so, and remember
649 * the highest claimed sequence number. This ensures that if we can
650 * read only part of the log now (e.g. due to a missing device),
651 * but we can read the entire log later, we will not try to replay
652 * or destroy beyond the last block we successfully claimed.
653 */
654 ASSERT3U(zh->zh_claim_txg, <=, first_txg);
655 if (zh->zh_claim_txg == 0 && !BP_IS_HOLE(&zh->zh_log)) {
656 (void) zil_parse(zilog, zil_claim_log_block,
657 zil_claim_log_record, tx, first_txg);
658 zh->zh_claim_txg = first_txg;
659 zh->zh_claim_blk_seq = zilog->zl_parse_blk_seq;
660 zh->zh_claim_lr_seq = zilog->zl_parse_lr_seq;
661 if (zilog->zl_parse_lr_count || zilog->zl_parse_blk_count > 1)
662 zh->zh_flags |= ZIL_REPLAY_NEEDED;
663 zh->zh_flags |= ZIL_CLAIM_LR_SEQ_VALID;
664 dsl_dataset_dirty(dmu_objset_ds(os), tx);
665 }
666
667 ASSERT3U(first_txg, ==, (spa_last_synced_txg(zilog->zl_spa) + 1));
668 dmu_objset_disown(os, FTAG);
669 return (0);
670 }
671
672 /*
673 * Check the log by walking the log chain.
674 * Checksum errors are ok as they indicate the end of the chain.
675 * Any other error (no device or read failure) returns an error.
676 */
677 int
678 zil_check_log_chain(const char *osname, void *tx)
679 {
680 zilog_t *zilog;
681 objset_t *os;
682 blkptr_t *bp;
683 int error;
684
685 ASSERT(tx == NULL);
686
687 error = dmu_objset_hold(osname, FTAG, &os);
688 if (error != 0) {
689 cmn_err(CE_WARN, "can't open objset for %s", osname);
690 return (0);
691 }
692
693 zilog = dmu_objset_zil(os);
694 bp = (blkptr_t *)&zilog->zl_header->zh_log;
695
696 /*
697 * Check the first block and determine if it's on a log device
698 * which may have been removed or faulted prior to loading this
699 * pool. If so, there's no point in checking the rest of the log
700 * as its content should have already been synced to the pool.
701 */
702 if (!BP_IS_HOLE(bp)) {
703 vdev_t *vd;
704 boolean_t valid = B_TRUE;
705
706 spa_config_enter(os->os_spa, SCL_STATE, FTAG, RW_READER);
707 vd = vdev_lookup_top(os->os_spa, DVA_GET_VDEV(&bp->blk_dva[0]));
708 if (vd->vdev_islog && vdev_is_dead(vd))
709 valid = vdev_log_state_valid(vd);
710 spa_config_exit(os->os_spa, SCL_STATE, FTAG);
711
712 if (!valid) {
713 dmu_objset_rele(os, FTAG);
714 return (0);
715 }
716 }
717
718 /*
719 * Because tx == NULL, zil_claim_log_block() will not actually claim
720 * any blocks, but just determine whether it is possible to do so.
721 * In addition to checking the log chain, zil_claim_log_block()
722 * will invoke zio_claim() with a done func of spa_claim_notify(),
723 * which will update spa_max_claim_txg. See spa_load() for details.
724 */
725 error = zil_parse(zilog, zil_claim_log_block, zil_claim_log_record, tx,
726 zilog->zl_header->zh_claim_txg ? -1ULL : spa_first_txg(os->os_spa));
727
728 dmu_objset_rele(os, FTAG);
729
730 return ((error == ECKSUM || error == ENOENT) ? 0 : error);
731 }
732
733 static int
734 zil_vdev_compare(const void *x1, const void *x2)
735 {
736 const uint64_t v1 = ((zil_vdev_node_t *)x1)->zv_vdev;
737 const uint64_t v2 = ((zil_vdev_node_t *)x2)->zv_vdev;
738
739 if (v1 < v2)
740 return (-1);
741 if (v1 > v2)
742 return (1);
743
744 return (0);
745 }
746
747 void
748 zil_add_block(zilog_t *zilog, const blkptr_t *bp)
749 {
750 avl_tree_t *t = &zilog->zl_vdev_tree;
751 avl_index_t where;
752 zil_vdev_node_t *zv, zvsearch;
753 int ndvas = BP_GET_NDVAS(bp);
754 int i;
755
756 if (zfs_nocacheflush)
757 return;
758
759 ASSERT(zilog->zl_writer);
760
761 /*
762 * Even though we're zl_writer, we still need a lock because the
763 * zl_get_data() callbacks may have dmu_sync() done callbacks
764 * that will run concurrently.
765 */
766 mutex_enter(&zilog->zl_vdev_lock);
767 for (i = 0; i < ndvas; i++) {
768 zvsearch.zv_vdev = DVA_GET_VDEV(&bp->blk_dva[i]);
769 if (avl_find(t, &zvsearch, &where) == NULL) {
770 zv = kmem_alloc(sizeof (*zv), KM_SLEEP);
771 zv->zv_vdev = zvsearch.zv_vdev;
772 avl_insert(t, zv, where);
773 }
774 }
775 mutex_exit(&zilog->zl_vdev_lock);
776 }
777
778 static void
779 zil_flush_vdevs(zilog_t *zilog)
780 {
781 spa_t *spa = zilog->zl_spa;
782 avl_tree_t *t = &zilog->zl_vdev_tree;
783 void *cookie = NULL;
784 zil_vdev_node_t *zv;
785 zio_t *zio;
786
787 ASSERT(zilog->zl_writer);
788
789 /*
790 * We don't need zl_vdev_lock here because we're the zl_writer,
791 * and all zl_get_data() callbacks are done.
792 */
793 if (avl_numnodes(t) == 0)
794 return;
795
796 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER);
797
798 zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL);
799
800 while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) {
801 vdev_t *vd = vdev_lookup_top(spa, zv->zv_vdev);
802 if (vd != NULL)
803 zio_flush(zio, vd);
804 kmem_free(zv, sizeof (*zv));
805 }
806
807 /*
808 * Wait for all the flushes to complete. Not all devices actually
809 * support the DKIOCFLUSHWRITECACHE ioctl, so it's OK if it fails.
810 */
811 (void) zio_wait(zio);
812
813 spa_config_exit(spa, SCL_STATE, FTAG);
814 }
815
816 /*
817 * Function called when a log block write completes
818 */
819 static void
820 zil_lwb_write_done(zio_t *zio)
821 {
822 lwb_t *lwb = zio->io_private;
823 zilog_t *zilog = lwb->lwb_zilog;
824 dmu_tx_t *tx = lwb->lwb_tx;
825
826 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF);
827 ASSERT(BP_GET_TYPE(zio->io_bp) == DMU_OT_INTENT_LOG);
828 ASSERT(BP_GET_LEVEL(zio->io_bp) == 0);
829 ASSERT(BP_GET_BYTEORDER(zio->io_bp) == ZFS_HOST_BYTEORDER);
830 ASSERT(!BP_IS_GANG(zio->io_bp));
831 ASSERT(!BP_IS_HOLE(zio->io_bp));
832 ASSERT(zio->io_bp->blk_fill == 0);
833
834 /*
835 * Ensure the lwb buffer pointer is cleared before releasing
836 * the txg. If we have had an allocation failure and
837 * the txg is waiting to sync then we want want zil_sync()
838 * to remove the lwb so that it's not picked up as the next new
839 * one in zil_commit_writer(). zil_sync() will only remove
840 * the lwb if lwb_buf is null.
841 */
842 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
843 mutex_enter(&zilog->zl_lock);
844 lwb->lwb_buf = NULL;
845 lwb->lwb_tx = NULL;
846 mutex_exit(&zilog->zl_lock);
847
848 /*
849 * Now that we've written this log block, we have a stable pointer
850 * to the next block in the chain, so it's OK to let the txg in
851 * which we allocated the next block sync.
852 */
853 dmu_tx_commit(tx);
854 }
855
856 /*
857 * Initialize the io for a log block.
858 */
859 static void
860 zil_lwb_write_init(zilog_t *zilog, lwb_t *lwb)
861 {
862 zbookmark_t zb;
863
864 SET_BOOKMARK(&zb, lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_OBJSET],
865 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL,
866 lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_SEQ]);
867
868 if (zilog->zl_root_zio == NULL) {
869 zilog->zl_root_zio = zio_root(zilog->zl_spa, NULL, NULL,
870 ZIO_FLAG_CANFAIL);
871 }
872 if (lwb->lwb_zio == NULL) {
873 lwb->lwb_zio = zio_rewrite(zilog->zl_root_zio, zilog->zl_spa,
874 0, &lwb->lwb_blk, lwb->lwb_buf, BP_GET_LSIZE(&lwb->lwb_blk),
875 zil_lwb_write_done, lwb, ZIO_PRIORITY_LOG_WRITE,
876 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE, &zb);
877 }
878 }
879
880 /*
881 * Define a limited set of intent log block sizes.
882 * These must be a multiple of 4KB. Note only the amount used (again
883 * aligned to 4KB) actually gets written. However, we can't always just
884 * allocate SPA_MAXBLOCKSIZE as the slog space could be exhausted.
885 */
886 uint64_t zil_block_buckets[] = {
887 4096, /* non TX_WRITE */
888 8192+4096, /* data base */
889 32*1024 + 4096, /* NFS writes */
890 UINT64_MAX
891 };
892
893 /*
894 * Use the slog as long as the logbias is 'latency' and the current commit size
895 * is less than the limit or the total list size is less than 2X the limit.
896 * Limit checking is disabled by setting zil_slog_limit to UINT64_MAX.
897 */
898 uint64_t zil_slog_limit = 1024 * 1024;
899 #define USE_SLOG(zilog) (((zilog)->zl_logbias == ZFS_LOGBIAS_LATENCY) && \
900 (((zilog)->zl_cur_used < zil_slog_limit) || \
901 ((zilog)->zl_itx_list_sz < (zil_slog_limit << 1))))
902
903 /*
904 * Start a log block write and advance to the next log block.
905 * Calls are serialized.
906 */
907 static lwb_t *
908 zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb)
909 {
910 lwb_t *nlwb = NULL;
911 zil_chain_t *zilc;
912 spa_t *spa = zilog->zl_spa;
913 blkptr_t *bp;
914 dmu_tx_t *tx;
915 uint64_t txg;
916 uint64_t zil_blksz, wsz;
917 int i, error;
918
919 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) {
920 zilc = (zil_chain_t *)lwb->lwb_buf;
921 bp = &zilc->zc_next_blk;
922 } else {
923 zilc = (zil_chain_t *)(lwb->lwb_buf + lwb->lwb_sz);
924 bp = &zilc->zc_next_blk;
925 }
926
927 ASSERT(lwb->lwb_nused <= lwb->lwb_sz);
928
929 /*
930 * Allocate the next block and save its address in this block
931 * before writing it in order to establish the log chain.
932 * Note that if the allocation of nlwb synced before we wrote
933 * the block that points at it (lwb), we'd leak it if we crashed.
934 * Therefore, we don't do dmu_tx_commit() until zil_lwb_write_done().
935 * We dirty the dataset to ensure that zil_sync() will be called
936 * to clean up in the event of allocation failure or I/O failure.
937 */
938 tx = dmu_tx_create(zilog->zl_os);
939 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0);
940 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
941 txg = dmu_tx_get_txg(tx);
942
943 lwb->lwb_tx = tx;
944
945 /*
946 * Log blocks are pre-allocated. Here we select the size of the next
947 * block, based on size used in the last block.
948 * - first find the smallest bucket that will fit the block from a
949 * limited set of block sizes. This is because it's faster to write
950 * blocks allocated from the same metaslab as they are adjacent or
951 * close.
952 * - next find the maximum from the new suggested size and an array of
953 * previous sizes. This lessens a picket fence effect of wrongly
954 * guesssing the size if we have a stream of say 2k, 64k, 2k, 64k
955 * requests.
956 *
957 * Note we only write what is used, but we can't just allocate
958 * the maximum block size because we can exhaust the available
959 * pool log space.
960 */
961 zil_blksz = zilog->zl_cur_used + sizeof (zil_chain_t);
962 for (i = 0; zil_blksz > zil_block_buckets[i]; i++)
963 continue;
964 zil_blksz = zil_block_buckets[i];
965 if (zil_blksz == UINT64_MAX)
966 zil_blksz = SPA_MAXBLOCKSIZE;
967 zilog->zl_prev_blks[zilog->zl_prev_rotor] = zil_blksz;
968 for (i = 0; i < ZIL_PREV_BLKS; i++)
969 zil_blksz = MAX(zil_blksz, zilog->zl_prev_blks[i]);
970 zilog->zl_prev_rotor = (zilog->zl_prev_rotor + 1) & (ZIL_PREV_BLKS - 1);
971
972 BP_ZERO(bp);
973 /* pass the old blkptr in order to spread log blocks across devs */
974 error = zio_alloc_zil(spa, txg, bp, &lwb->lwb_blk, zil_blksz,
975 USE_SLOG(zilog));
976 if (error == 0) {
977 ASSERT3U(bp->blk_birth, ==, txg);
978 bp->blk_cksum = lwb->lwb_blk.blk_cksum;
979 bp->blk_cksum.zc_word[ZIL_ZC_SEQ]++;
980
981 /*
982 * Allocate a new log write buffer (lwb).
983 */
984 nlwb = zil_alloc_lwb(zilog, bp, txg);
985
986 /* Record the block for later vdev flushing */
987 zil_add_block(zilog, &lwb->lwb_blk);
988 }
989
990 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) {
991 /* For Slim ZIL only write what is used. */
992 wsz = P2ROUNDUP_TYPED(lwb->lwb_nused, ZIL_MIN_BLKSZ, uint64_t);
993 ASSERT3U(wsz, <=, lwb->lwb_sz);
994 zio_shrink(lwb->lwb_zio, wsz);
995
996 } else {
997 wsz = lwb->lwb_sz;
998 }
999
1000 zilc->zc_pad = 0;
1001 zilc->zc_nused = lwb->lwb_nused;
1002 zilc->zc_eck.zec_cksum = lwb->lwb_blk.blk_cksum;
1003
1004 /*
1005 * clear unused data for security
1006 */
1007 bzero(lwb->lwb_buf + lwb->lwb_nused, wsz - lwb->lwb_nused);
1008
1009 zio_nowait(lwb->lwb_zio); /* Kick off the write for the old log block */
1010
1011 /*
1012 * If there was an allocation failure then nlwb will be null which
1013 * forces a txg_wait_synced().
1014 */
1015 return (nlwb);
1016 }
1017
1018 static lwb_t *
1019 zil_lwb_commit(zilog_t *zilog, itx_t *itx, lwb_t *lwb)
1020 {
1021 lr_t *lrc = &itx->itx_lr; /* common log record */
1022 lr_write_t *lrw = (lr_write_t *)lrc;
1023 char *lr_buf;
1024 uint64_t txg = lrc->lrc_txg;
1025 uint64_t reclen = lrc->lrc_reclen;
1026 uint64_t dlen = 0;
1027
1028 if (lwb == NULL)
1029 return (NULL);
1030
1031 ASSERT(lwb->lwb_buf != NULL);
1032 ASSERT(zilog_is_dirty(zilog) ||
1033 spa_freeze_txg(zilog->zl_spa) != UINT64_MAX);
1034
1035 if (lrc->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY)
1036 dlen = P2ROUNDUP_TYPED(
1037 lrw->lr_length, sizeof (uint64_t), uint64_t);
1038
1039 zilog->zl_cur_used += (reclen + dlen);
1040
1041 zil_lwb_write_init(zilog, lwb);
1042
1043 /*
1044 * If this record won't fit in the current log block, start a new one.
1045 */
1046 if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) {
1047 lwb = zil_lwb_write_start(zilog, lwb);
1048 if (lwb == NULL)
1049 return (NULL);
1050 zil_lwb_write_init(zilog, lwb);
1051 ASSERT(LWB_EMPTY(lwb));
1052 if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) {
1053 txg_wait_synced(zilog->zl_dmu_pool, txg);
1054 return (lwb);
1055 }
1056 }
1057
1058 lr_buf = lwb->lwb_buf + lwb->lwb_nused;
1059 bcopy(lrc, lr_buf, reclen);
1060 lrc = (lr_t *)lr_buf;
1061 lrw = (lr_write_t *)lrc;
1062
1063 /*
1064 * If it's a write, fetch the data or get its blkptr as appropriate.
1065 */
1066 if (lrc->lrc_txtype == TX_WRITE) {
1067 if (txg > spa_freeze_txg(zilog->zl_spa))
1068 txg_wait_synced(zilog->zl_dmu_pool, txg);
1069 if (itx->itx_wr_state != WR_COPIED) {
1070 char *dbuf;
1071 int error;
1072
1073 if (dlen) {
1074 ASSERT(itx->itx_wr_state == WR_NEED_COPY);
1075 dbuf = lr_buf + reclen;
1076 lrw->lr_common.lrc_reclen += dlen;
1077 } else {
1078 ASSERT(itx->itx_wr_state == WR_INDIRECT);
1079 dbuf = NULL;
1080 }
1081 error = zilog->zl_get_data(
1082 itx->itx_private, lrw, dbuf, lwb->lwb_zio);
1083 if (error == EIO) {
1084 txg_wait_synced(zilog->zl_dmu_pool, txg);
1085 return (lwb);
1086 }
1087 if (error != 0) {
1088 ASSERT(error == ENOENT || error == EEXIST ||
1089 error == EALREADY);
1090 return (lwb);
1091 }
1092 }
1093 }
1094
1095 /*
1096 * We're actually making an entry, so update lrc_seq to be the
1097 * log record sequence number. Note that this is generally not
1098 * equal to the itx sequence number because not all transactions
1099 * are synchronous, and sometimes spa_sync() gets there first.
1100 */
1101 lrc->lrc_seq = ++zilog->zl_lr_seq; /* we are single threaded */
1102 lwb->lwb_nused += reclen + dlen;
1103 lwb->lwb_max_txg = MAX(lwb->lwb_max_txg, txg);
1104 ASSERT3U(lwb->lwb_nused, <=, lwb->lwb_sz);
1105 ASSERT0(P2PHASE(lwb->lwb_nused, sizeof (uint64_t)));
1106
1107 return (lwb);
1108 }
1109
1110 itx_t *
1111 zil_itx_create(uint64_t txtype, size_t lrsize)
1112 {
1113 itx_t *itx;
1114
1115 lrsize = P2ROUNDUP_TYPED(lrsize, sizeof (uint64_t), size_t);
1116
1117 itx = kmem_alloc(offsetof(itx_t, itx_lr) + lrsize, KM_SLEEP);
1118 itx->itx_lr.lrc_txtype = txtype;
1119 itx->itx_lr.lrc_reclen = lrsize;
1120 itx->itx_sod = lrsize; /* if write & WR_NEED_COPY will be increased */
1121 itx->itx_lr.lrc_seq = 0; /* defensive */
1122 itx->itx_sync = B_TRUE; /* default is synchronous */
1123
1124 return (itx);
1125 }
1126
1127 void
1128 zil_itx_destroy(itx_t *itx)
1129 {
1130 kmem_free(itx, offsetof(itx_t, itx_lr) + itx->itx_lr.lrc_reclen);
1131 }
1132
1133 /*
1134 * Free up the sync and async itxs. The itxs_t has already been detached
1135 * so no locks are needed.
1136 */
1137 static void
1138 zil_itxg_clean(itxs_t *itxs)
1139 {
1140 itx_t *itx;
1141 list_t *list;
1142 avl_tree_t *t;
1143 void *cookie;
1144 itx_async_node_t *ian;
1145
1146 list = &itxs->i_sync_list;
1147 while ((itx = list_head(list)) != NULL) {
1148 list_remove(list, itx);
1149 kmem_free(itx, offsetof(itx_t, itx_lr) +
1150 itx->itx_lr.lrc_reclen);
1151 }
1152
1153 cookie = NULL;
1154 t = &itxs->i_async_tree;
1155 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) {
1156 list = &ian->ia_list;
1157 while ((itx = list_head(list)) != NULL) {
1158 list_remove(list, itx);
1159 kmem_free(itx, offsetof(itx_t, itx_lr) +
1160 itx->itx_lr.lrc_reclen);
1161 }
1162 list_destroy(list);
1163 kmem_free(ian, sizeof (itx_async_node_t));
1164 }
1165 avl_destroy(t);
1166
1167 kmem_free(itxs, sizeof (itxs_t));
1168 }
1169
1170 static int
1171 zil_aitx_compare(const void *x1, const void *x2)
1172 {
1173 const uint64_t o1 = ((itx_async_node_t *)x1)->ia_foid;
1174 const uint64_t o2 = ((itx_async_node_t *)x2)->ia_foid;
1175
1176 if (o1 < o2)
1177 return (-1);
1178 if (o1 > o2)
1179 return (1);
1180
1181 return (0);
1182 }
1183
1184 /*
1185 * Remove all async itx with the given oid.
1186 */
1187 static void
1188 zil_remove_async(zilog_t *zilog, uint64_t oid)
1189 {
1190 uint64_t otxg, txg;
1191 itx_async_node_t *ian;
1192 avl_tree_t *t;
1193 avl_index_t where;
1194 list_t clean_list;
1195 itx_t *itx;
1196
1197 ASSERT(oid != 0);
1198 list_create(&clean_list, sizeof (itx_t), offsetof(itx_t, itx_node));
1199
1200 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */
1201 otxg = ZILTEST_TXG;
1202 else
1203 otxg = spa_last_synced_txg(zilog->zl_spa) + 1;
1204
1205 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) {
1206 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK];
1207
1208 mutex_enter(&itxg->itxg_lock);
1209 if (itxg->itxg_txg != txg) {
1210 mutex_exit(&itxg->itxg_lock);
1211 continue;
1212 }
1213
1214 /*
1215 * Locate the object node and append its list.
1216 */
1217 t = &itxg->itxg_itxs->i_async_tree;
1218 ian = avl_find(t, &oid, &where);
1219 if (ian != NULL)
1220 list_move_tail(&clean_list, &ian->ia_list);
1221 mutex_exit(&itxg->itxg_lock);
1222 }
1223 while ((itx = list_head(&clean_list)) != NULL) {
1224 list_remove(&clean_list, itx);
1225 kmem_free(itx, offsetof(itx_t, itx_lr) +
1226 itx->itx_lr.lrc_reclen);
1227 }
1228 list_destroy(&clean_list);
1229 }
1230
1231 void
1232 zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx)
1233 {
1234 uint64_t txg;
1235 itxg_t *itxg;
1236 itxs_t *itxs, *clean = NULL;
1237
1238 /*
1239 * Object ids can be re-instantiated in the next txg so
1240 * remove any async transactions to avoid future leaks.
1241 * This can happen if a fsync occurs on the re-instantiated
1242 * object for a WR_INDIRECT or WR_NEED_COPY write, which gets
1243 * the new file data and flushes a write record for the old object.
1244 */
1245 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_REMOVE)
1246 zil_remove_async(zilog, itx->itx_oid);
1247
1248 /*
1249 * Ensure the data of a renamed file is committed before the rename.
1250 */
1251 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_RENAME)
1252 zil_async_to_sync(zilog, itx->itx_oid);
1253
1254 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX)
1255 txg = ZILTEST_TXG;
1256 else
1257 txg = dmu_tx_get_txg(tx);
1258
1259 itxg = &zilog->zl_itxg[txg & TXG_MASK];
1260 mutex_enter(&itxg->itxg_lock);
1261 itxs = itxg->itxg_itxs;
1262 if (itxg->itxg_txg != txg) {
1263 if (itxs != NULL) {
1264 /*
1265 * The zil_clean callback hasn't got around to cleaning
1266 * this itxg. Save the itxs for release below.
1267 * This should be rare.
1268 */
1269 atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod);
1270 itxg->itxg_sod = 0;
1271 clean = itxg->itxg_itxs;
1272 }
1273 ASSERT(itxg->itxg_sod == 0);
1274 itxg->itxg_txg = txg;
1275 itxs = itxg->itxg_itxs = kmem_zalloc(sizeof (itxs_t), KM_SLEEP);
1276
1277 list_create(&itxs->i_sync_list, sizeof (itx_t),
1278 offsetof(itx_t, itx_node));
1279 avl_create(&itxs->i_async_tree, zil_aitx_compare,
1280 sizeof (itx_async_node_t),
1281 offsetof(itx_async_node_t, ia_node));
1282 }
1283 if (itx->itx_sync) {
1284 list_insert_tail(&itxs->i_sync_list, itx);
1285 atomic_add_64(&zilog->zl_itx_list_sz, itx->itx_sod);
1286 itxg->itxg_sod += itx->itx_sod;
1287 } else {
1288 avl_tree_t *t = &itxs->i_async_tree;
1289 uint64_t foid = ((lr_ooo_t *)&itx->itx_lr)->lr_foid;
1290 itx_async_node_t *ian;
1291 avl_index_t where;
1292
1293 ian = avl_find(t, &foid, &where);
1294 if (ian == NULL) {
1295 ian = kmem_alloc(sizeof (itx_async_node_t), KM_SLEEP);
1296 list_create(&ian->ia_list, sizeof (itx_t),
1297 offsetof(itx_t, itx_node));
1298 ian->ia_foid = foid;
1299 avl_insert(t, ian, where);
1300 }
1301 list_insert_tail(&ian->ia_list, itx);
1302 }
1303
1304 itx->itx_lr.lrc_txg = dmu_tx_get_txg(tx);
1305 zilog_dirty(zilog, txg);
1306 mutex_exit(&itxg->itxg_lock);
1307
1308 /* Release the old itxs now we've dropped the lock */
1309 if (clean != NULL)
1310 zil_itxg_clean(clean);
1311 }
1312
1313 /*
1314 * If there are any in-memory intent log transactions which have now been
1315 * synced then start up a taskq to free them. We should only do this after we
1316 * have written out the uberblocks (i.e. txg has been comitted) so that
1317 * don't inadvertently clean out in-memory log records that would be required
1318 * by zil_commit().
1319 */
1320 void
1321 zil_clean(zilog_t *zilog, uint64_t synced_txg)
1322 {
1323 itxg_t *itxg = &zilog->zl_itxg[synced_txg & TXG_MASK];
1324 itxs_t *clean_me;
1325
1326 mutex_enter(&itxg->itxg_lock);
1327 if (itxg->itxg_itxs == NULL || itxg->itxg_txg == ZILTEST_TXG) {
1328 mutex_exit(&itxg->itxg_lock);
1329 return;
1330 }
1331 ASSERT3U(itxg->itxg_txg, <=, synced_txg);
1332 ASSERT(itxg->itxg_txg != 0);
1333 ASSERT(zilog->zl_clean_taskq != NULL);
1334 atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod);
1335 itxg->itxg_sod = 0;
1336 clean_me = itxg->itxg_itxs;
1337 itxg->itxg_itxs = NULL;
1338 itxg->itxg_txg = 0;
1339 mutex_exit(&itxg->itxg_lock);
1340 /*
1341 * Preferably start a task queue to free up the old itxs but
1342 * if taskq_dispatch can't allocate resources to do that then
1343 * free it in-line. This should be rare. Note, using TQ_SLEEP
1344 * created a bad performance problem.
1345 */
1346 if (taskq_dispatch(zilog->zl_clean_taskq,
1347 (void (*)(void *))zil_itxg_clean, clean_me, TQ_NOSLEEP) == NULL)
1348 zil_itxg_clean(clean_me);
1349 }
1350
1351 /*
1352 * Get the list of itxs to commit into zl_itx_commit_list.
1353 */
1354 static void
1355 zil_get_commit_list(zilog_t *zilog)
1356 {
1357 uint64_t otxg, txg;
1358 list_t *commit_list = &zilog->zl_itx_commit_list;
1359 uint64_t push_sod = 0;
1360
1361 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */
1362 otxg = ZILTEST_TXG;
1363 else
1364 otxg = spa_last_synced_txg(zilog->zl_spa) + 1;
1365
1366 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) {
1367 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK];
1368
1369 mutex_enter(&itxg->itxg_lock);
1370 if (itxg->itxg_txg != txg) {
1371 mutex_exit(&itxg->itxg_lock);
1372 continue;
1373 }
1374
1375 list_move_tail(commit_list, &itxg->itxg_itxs->i_sync_list);
1376 push_sod += itxg->itxg_sod;
1377 itxg->itxg_sod = 0;
1378
1379 mutex_exit(&itxg->itxg_lock);
1380 }
1381 atomic_add_64(&zilog->zl_itx_list_sz, -push_sod);
1382 }
1383
1384 /*
1385 * Move the async itxs for a specified object to commit into sync lists.
1386 */
1387 static void
1388 zil_async_to_sync(zilog_t *zilog, uint64_t foid)
1389 {
1390 uint64_t otxg, txg;
1391 itx_async_node_t *ian;
1392 avl_tree_t *t;
1393 avl_index_t where;
1394
1395 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */
1396 otxg = ZILTEST_TXG;
1397 else
1398 otxg = spa_last_synced_txg(zilog->zl_spa) + 1;
1399
1400 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) {
1401 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK];
1402
1403 mutex_enter(&itxg->itxg_lock);
1404 if (itxg->itxg_txg != txg) {
1405 mutex_exit(&itxg->itxg_lock);
1406 continue;
1407 }
1408
1409 /*
1410 * If a foid is specified then find that node and append its
1411 * list. Otherwise walk the tree appending all the lists
1412 * to the sync list. We add to the end rather than the
1413 * beginning to ensure the create has happened.
1414 */
1415 t = &itxg->itxg_itxs->i_async_tree;
1416 if (foid != 0) {
1417 ian = avl_find(t, &foid, &where);
1418 if (ian != NULL) {
1419 list_move_tail(&itxg->itxg_itxs->i_sync_list,
1420 &ian->ia_list);
1421 }
1422 } else {
1423 void *cookie = NULL;
1424
1425 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) {
1426 list_move_tail(&itxg->itxg_itxs->i_sync_list,
1427 &ian->ia_list);
1428 list_destroy(&ian->ia_list);
1429 kmem_free(ian, sizeof (itx_async_node_t));
1430 }
1431 }
1432 mutex_exit(&itxg->itxg_lock);
1433 }
1434 }
1435
1436 static void
1437 zil_commit_writer(zilog_t *zilog)
1438 {
1439 uint64_t txg;
1440 itx_t *itx;
1441 lwb_t *lwb;
1442 spa_t *spa = zilog->zl_spa;
1443 int error = 0;
1444
1445 ASSERT(zilog->zl_root_zio == NULL);
1446
1447 mutex_exit(&zilog->zl_lock);
1448
1449 zil_get_commit_list(zilog);
1450
1451 /*
1452 * Return if there's nothing to commit before we dirty the fs by
1453 * calling zil_create().
1454 */
1455 if (list_head(&zilog->zl_itx_commit_list) == NULL) {
1456 mutex_enter(&zilog->zl_lock);
1457 return;
1458 }
1459
1460 if (zilog->zl_suspend) {
1461 lwb = NULL;
1462 } else {
1463 lwb = list_tail(&zilog->zl_lwb_list);
1464 if (lwb == NULL)
1465 lwb = zil_create(zilog);
1466 }
1467
1468 DTRACE_PROBE1(zil__cw1, zilog_t *, zilog);
1469 while (itx = list_head(&zilog->zl_itx_commit_list)) {
1470 txg = itx->itx_lr.lrc_txg;
1471 ASSERT(txg);
1472
1473 if (txg > spa_last_synced_txg(spa) || txg > spa_freeze_txg(spa))
1474 lwb = zil_lwb_commit(zilog, itx, lwb);
1475 list_remove(&zilog->zl_itx_commit_list, itx);
1476 kmem_free(itx, offsetof(itx_t, itx_lr)
1477 + itx->itx_lr.lrc_reclen);
1478 }
1479 DTRACE_PROBE1(zil__cw2, zilog_t *, zilog);
1480
1481 /* write the last block out */
1482 if (lwb != NULL && lwb->lwb_zio != NULL)
1483 lwb = zil_lwb_write_start(zilog, lwb);
1484
1485 zilog->zl_cur_used = 0;
1486
1487 /*
1488 * Wait if necessary for the log blocks to be on stable storage.
1489 */
1490 if (zilog->zl_root_zio) {
1491 error = zio_wait(zilog->zl_root_zio);
1492 zilog->zl_root_zio = NULL;
1493 zil_flush_vdevs(zilog);
1494 }
1495
1496 if (error || lwb == NULL)
1497 txg_wait_synced(zilog->zl_dmu_pool, 0);
1498
1499 mutex_enter(&zilog->zl_lock);
1500
1501 /*
1502 * Remember the highest committed log sequence number for ztest.
1503 * We only update this value when all the log writes succeeded,
1504 * because ztest wants to ASSERT that it got the whole log chain.
1505 */
1506 if (error == 0 && lwb != NULL)
1507 zilog->zl_commit_lr_seq = zilog->zl_lr_seq;
1508 }
1509
1510 /*
1511 * Commit zfs transactions to stable storage.
1512 * If foid is 0 push out all transactions, otherwise push only those
1513 * for that object or might reference that object.
1514 *
1515 * itxs are committed in batches. In a heavily stressed zil there will be
1516 * a commit writer thread who is writing out a bunch of itxs to the log
1517 * for a set of committing threads (cthreads) in the same batch as the writer.
1518 * Those cthreads are all waiting on the same cv for that batch.
1519 *
1520 * There will also be a different and growing batch of threads that are
1521 * waiting to commit (qthreads). When the committing batch completes
1522 * a transition occurs such that the cthreads exit and the qthreads become
1523 * cthreads. One of the new cthreads becomes the writer thread for the
1524 * batch. Any new threads arriving become new qthreads.
1525 *
1526 * Only 2 condition variables are needed and there's no transition
1527 * between the two cvs needed. They just flip-flop between qthreads
1528 * and cthreads.
1529 *
1530 * Using this scheme we can efficiently wakeup up only those threads
1531 * that have been committed.
1532 */
1533 void
1534 zil_commit(zilog_t *zilog, uint64_t foid)
1535 {
1536 uint64_t mybatch;
1537
1538 if (zilog->zl_sync == ZFS_SYNC_DISABLED)
1539 return;
1540
1541 /* move the async itxs for the foid to the sync queues */
1542 zil_async_to_sync(zilog, foid);
1543
1544 mutex_enter(&zilog->zl_lock);
1545 mybatch = zilog->zl_next_batch;
1546 while (zilog->zl_writer) {
1547 cv_wait(&zilog->zl_cv_batch[mybatch & 1], &zilog->zl_lock);
1548 if (mybatch <= zilog->zl_com_batch) {
1549 mutex_exit(&zilog->zl_lock);
1550 return;
1551 }
1552 }
1553
1554 zilog->zl_next_batch++;
1555 zilog->zl_writer = B_TRUE;
1556 zil_commit_writer(zilog);
1557 zilog->zl_com_batch = mybatch;
1558 zilog->zl_writer = B_FALSE;
1559 mutex_exit(&zilog->zl_lock);
1560
1561 /* wake up one thread to become the next writer */
1562 cv_signal(&zilog->zl_cv_batch[(mybatch+1) & 1]);
1563
1564 /* wake up all threads waiting for this batch to be committed */
1565 cv_broadcast(&zilog->zl_cv_batch[mybatch & 1]);
1566 }
1567
1568 /*
1569 * Called in syncing context to free committed log blocks and update log header.
1570 */
1571 void
1572 zil_sync(zilog_t *zilog, dmu_tx_t *tx)
1573 {
1574 zil_header_t *zh = zil_header_in_syncing_context(zilog);
1575 uint64_t txg = dmu_tx_get_txg(tx);
1576 spa_t *spa = zilog->zl_spa;
1577 uint64_t *replayed_seq = &zilog->zl_replayed_seq[txg & TXG_MASK];
1578 lwb_t *lwb;
1579
1580 /*
1581 * We don't zero out zl_destroy_txg, so make sure we don't try
1582 * to destroy it twice.
1583 */
1584 if (spa_sync_pass(spa) != 1)
1585 return;
1586
1587 mutex_enter(&zilog->zl_lock);
1588
1589 ASSERT(zilog->zl_stop_sync == 0);
1590
1591 if (*replayed_seq != 0) {
1592 ASSERT(zh->zh_replay_seq < *replayed_seq);
1593 zh->zh_replay_seq = *replayed_seq;
1594 *replayed_seq = 0;
1595 }
1596
1597 if (zilog->zl_destroy_txg == txg) {
1598 blkptr_t blk = zh->zh_log;
1599
1600 ASSERT(list_head(&zilog->zl_lwb_list) == NULL);
1601
1602 bzero(zh, sizeof (zil_header_t));
1603 bzero(zilog->zl_replayed_seq, sizeof (zilog->zl_replayed_seq));
1604
1605 if (zilog->zl_keep_first) {
1606 /*
1607 * If this block was part of log chain that couldn't
1608 * be claimed because a device was missing during
1609 * zil_claim(), but that device later returns,
1610 * then this block could erroneously appear valid.
1611 * To guard against this, assign a new GUID to the new
1612 * log chain so it doesn't matter what blk points to.
1613 */
1614 zil_init_log_chain(zilog, &blk);
1615 zh->zh_log = blk;
1616 }
1617 }
1618
1619 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) {
1620 zh->zh_log = lwb->lwb_blk;
1621 if (lwb->lwb_buf != NULL || lwb->lwb_max_txg > txg)
1622 break;
1623 list_remove(&zilog->zl_lwb_list, lwb);
1624 zio_free_zil(spa, txg, &lwb->lwb_blk);
1625 kmem_cache_free(zil_lwb_cache, lwb);
1626
1627 /*
1628 * If we don't have anything left in the lwb list then
1629 * we've had an allocation failure and we need to zero
1630 * out the zil_header blkptr so that we don't end
1631 * up freeing the same block twice.
1632 */
1633 if (list_head(&zilog->zl_lwb_list) == NULL)
1634 BP_ZERO(&zh->zh_log);
1635 }
1636 mutex_exit(&zilog->zl_lock);
1637 }
1638
1639 void
1640 zil_init(void)
1641 {
1642 zil_lwb_cache = kmem_cache_create("zil_lwb_cache",
1643 sizeof (struct lwb), 0, NULL, NULL, NULL, NULL, NULL, 0);
1644 }
1645
1646 void
1647 zil_fini(void)
1648 {
1649 kmem_cache_destroy(zil_lwb_cache);
1650 }
1651
1652 void
1653 zil_set_sync(zilog_t *zilog, uint64_t sync)
1654 {
1655 zilog->zl_sync = sync;
1656 }
1657
1658 void
1659 zil_set_logbias(zilog_t *zilog, uint64_t logbias)
1660 {
1661 zilog->zl_logbias = logbias;
1662 }
1663
1664 zilog_t *
1665 zil_alloc(objset_t *os, zil_header_t *zh_phys)
1666 {
1667 zilog_t *zilog;
1668
1669 zilog = kmem_zalloc(sizeof (zilog_t), KM_SLEEP);
1670
1671 zilog->zl_header = zh_phys;
1672 zilog->zl_os = os;
1673 zilog->zl_spa = dmu_objset_spa(os);
1674 zilog->zl_dmu_pool = dmu_objset_pool(os);
1675 zilog->zl_destroy_txg = TXG_INITIAL - 1;
1676 zilog->zl_logbias = dmu_objset_logbias(os);
1677 zilog->zl_sync = dmu_objset_syncprop(os);
1678 zilog->zl_next_batch = 1;
1679
1680 mutex_init(&zilog->zl_lock, NULL, MUTEX_DEFAULT, NULL);
1681
1682 for (int i = 0; i < TXG_SIZE; i++) {
1683 mutex_init(&zilog->zl_itxg[i].itxg_lock, NULL,
1684 MUTEX_DEFAULT, NULL);
1685 }
1686
1687 list_create(&zilog->zl_lwb_list, sizeof (lwb_t),
1688 offsetof(lwb_t, lwb_node));
1689
1690 list_create(&zilog->zl_itx_commit_list, sizeof (itx_t),
1691 offsetof(itx_t, itx_node));
1692
1693 mutex_init(&zilog->zl_vdev_lock, NULL, MUTEX_DEFAULT, NULL);
1694
1695 avl_create(&zilog->zl_vdev_tree, zil_vdev_compare,
1696 sizeof (zil_vdev_node_t), offsetof(zil_vdev_node_t, zv_node));
1697
1698 cv_init(&zilog->zl_cv_writer, NULL, CV_DEFAULT, NULL);
1699 cv_init(&zilog->zl_cv_suspend, NULL, CV_DEFAULT, NULL);
1700 cv_init(&zilog->zl_cv_batch[0], NULL, CV_DEFAULT, NULL);
1701 cv_init(&zilog->zl_cv_batch[1], NULL, CV_DEFAULT, NULL);
1702
1703 return (zilog);
1704 }
1705
1706 void
1707 zil_free(zilog_t *zilog)
1708 {
1709 zilog->zl_stop_sync = 1;
1710
1711 ASSERT0(zilog->zl_suspend);
1712 ASSERT0(zilog->zl_suspending);
1713
1714 ASSERT(list_is_empty(&zilog->zl_lwb_list));
1715 list_destroy(&zilog->zl_lwb_list);
1716
1717 avl_destroy(&zilog->zl_vdev_tree);
1718 mutex_destroy(&zilog->zl_vdev_lock);
1719
1720 ASSERT(list_is_empty(&zilog->zl_itx_commit_list));
1721 list_destroy(&zilog->zl_itx_commit_list);
1722
1723 for (int i = 0; i < TXG_SIZE; i++) {
1724 /*
1725 * It's possible for an itx to be generated that doesn't dirty
1726 * a txg (e.g. ztest TX_TRUNCATE). So there's no zil_clean()
1727 * callback to remove the entry. We remove those here.
1728 *
1729 * Also free up the ziltest itxs.
1730 */
1731 if (zilog->zl_itxg[i].itxg_itxs)
1732 zil_itxg_clean(zilog->zl_itxg[i].itxg_itxs);
1733 mutex_destroy(&zilog->zl_itxg[i].itxg_lock);
1734 }
1735
1736 mutex_destroy(&zilog->zl_lock);
1737
1738 cv_destroy(&zilog->zl_cv_writer);
1739 cv_destroy(&zilog->zl_cv_suspend);
1740 cv_destroy(&zilog->zl_cv_batch[0]);
1741 cv_destroy(&zilog->zl_cv_batch[1]);
1742
1743 kmem_free(zilog, sizeof (zilog_t));
1744 }
1745
1746 /*
1747 * Open an intent log.
1748 */
1749 zilog_t *
1750 zil_open(objset_t *os, zil_get_data_t *get_data)
1751 {
1752 zilog_t *zilog = dmu_objset_zil(os);
1753
1754 ASSERT(zilog->zl_clean_taskq == NULL);
1755 ASSERT(zilog->zl_get_data == NULL);
1756 ASSERT(list_is_empty(&zilog->zl_lwb_list));
1757
1758 zilog->zl_get_data = get_data;
1759 zilog->zl_clean_taskq = taskq_create("zil_clean", 1, minclsyspri,
1760 2, 2, TASKQ_PREPOPULATE);
1761
1762 return (zilog);
1763 }
1764
1765 /*
1766 * Close an intent log.
1767 */
1768 void
1769 zil_close(zilog_t *zilog)
1770 {
1771 lwb_t *lwb;
1772 uint64_t txg = 0;
1773
1774 zil_commit(zilog, 0); /* commit all itx */
1775
1776 /*
1777 * The lwb_max_txg for the stubby lwb will reflect the last activity
1778 * for the zil. After a txg_wait_synced() on the txg we know all the
1779 * callbacks have occurred that may clean the zil. Only then can we
1780 * destroy the zl_clean_taskq.
1781 */
1782 mutex_enter(&zilog->zl_lock);
1783 lwb = list_tail(&zilog->zl_lwb_list);
1784 if (lwb != NULL)
1785 txg = lwb->lwb_max_txg;
1786 mutex_exit(&zilog->zl_lock);
1787 if (txg)
1788 txg_wait_synced(zilog->zl_dmu_pool, txg);
1789 ASSERT(!zilog_is_dirty(zilog));
1790
1791 taskq_destroy(zilog->zl_clean_taskq);
1792 zilog->zl_clean_taskq = NULL;
1793 zilog->zl_get_data = NULL;
1794
1795 /*
1796 * We should have only one LWB left on the list; remove it now.
1797 */
1798 mutex_enter(&zilog->zl_lock);
1799 lwb = list_head(&zilog->zl_lwb_list);
1800 if (lwb != NULL) {
1801 ASSERT(lwb == list_tail(&zilog->zl_lwb_list));
1802 list_remove(&zilog->zl_lwb_list, lwb);
1803 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz);
1804 kmem_cache_free(zil_lwb_cache, lwb);
1805 }
1806 mutex_exit(&zilog->zl_lock);
1807 }
1808
1809 static char *suspend_tag = "zil suspending";
1810
1811 /*
1812 * Suspend an intent log. While in suspended mode, we still honor
1813 * synchronous semantics, but we rely on txg_wait_synced() to do it.
1814 * On old version pools, we suspend the log briefly when taking a
1815 * snapshot so that it will have an empty intent log.
1816 *
1817 * Long holds are not really intended to be used the way we do here --
1818 * held for such a short time. A concurrent caller of dsl_dataset_long_held()
1819 * could fail. Therefore we take pains to only put a long hold if it is
1820 * actually necessary. Fortunately, it will only be necessary if the
1821 * objset is currently mounted (or the ZVOL equivalent). In that case it
1822 * will already have a long hold, so we are not really making things any worse.
1823 *
1824 * Ideally, we would locate the existing long-holder (i.e. the zfsvfs_t or
1825 * zvol_state_t), and use their mechanism to prevent their hold from being
1826 * dropped (e.g. VFS_HOLD()). However, that would be even more pain for
1827 * very little gain.
1828 *
1829 * if cookiep == NULL, this does both the suspend & resume.
1830 * Otherwise, it returns with the dataset "long held", and the cookie
1831 * should be passed into zil_resume().
1832 */
1833 int
1834 zil_suspend(const char *osname, void **cookiep)
1835 {
1836 objset_t *os;
1837 zilog_t *zilog;
1838 const zil_header_t *zh;
1839 int error;
1840
1841 error = dmu_objset_hold(osname, suspend_tag, &os);
1842 if (error != 0)
1843 return (error);
1844 zilog = dmu_objset_zil(os);
1845
1846 mutex_enter(&zilog->zl_lock);
1847 zh = zilog->zl_header;
1848
1849 if (zh->zh_flags & ZIL_REPLAY_NEEDED) { /* unplayed log */
1850 mutex_exit(&zilog->zl_lock);
1851 dmu_objset_rele(os, suspend_tag);
1852 return (SET_ERROR(EBUSY));
1853 }
1854
1855 /*
1856 * Don't put a long hold in the cases where we can avoid it. This
1857 * is when there is no cookie so we are doing a suspend & resume
1858 * (i.e. called from zil_vdev_offline()), and there's nothing to do
1859 * for the suspend because it's already suspended, or there's no ZIL.
1860 */
1861 if (cookiep == NULL && !zilog->zl_suspending &&
1862 (zilog->zl_suspend > 0 || BP_IS_HOLE(&zh->zh_log))) {
1863 mutex_exit(&zilog->zl_lock);
1864 dmu_objset_rele(os, suspend_tag);
1865 return (0);
1866 }
1867
1868 dsl_dataset_long_hold(dmu_objset_ds(os), suspend_tag);
1869 dsl_pool_rele(dmu_objset_pool(os), suspend_tag);
1870
1871 zilog->zl_suspend++;
1872
1873 if (zilog->zl_suspend > 1) {
1874 /*
1875 * Someone else is already suspending it.
1876 * Just wait for them to finish.
1877 */
1878
1879 while (zilog->zl_suspending)
1880 cv_wait(&zilog->zl_cv_suspend, &zilog->zl_lock);
1881 mutex_exit(&zilog->zl_lock);
1882
1883 if (cookiep == NULL)
1884 zil_resume(os);
1885 else
1886 *cookiep = os;
1887 return (0);
1888 }
1889
1890 /*
1891 * If there is no pointer to an on-disk block, this ZIL must not
1892 * be active (e.g. filesystem not mounted), so there's nothing
1893 * to clean up.
1894 */
1895 if (BP_IS_HOLE(&zh->zh_log)) {
1896 ASSERT(cookiep != NULL); /* fast path already handled */
1897
1898 *cookiep = os;
1899 mutex_exit(&zilog->zl_lock);
1900 return (0);
1901 }
1902
1903 zilog->zl_suspending = B_TRUE;
1904 mutex_exit(&zilog->zl_lock);
1905
1906 zil_commit(zilog, 0);
1907
1908 zil_destroy(zilog, B_FALSE);
1909
1910 mutex_enter(&zilog->zl_lock);
1911 zilog->zl_suspending = B_FALSE;
1912 cv_broadcast(&zilog->zl_cv_suspend);
1913 mutex_exit(&zilog->zl_lock);
1914
1915 if (cookiep == NULL)
1916 zil_resume(os);
1917 else
1918 *cookiep = os;
1919 return (0);
1920 }
1921
1922 void
1923 zil_resume(void *cookie)
1924 {
1925 objset_t *os = cookie;
1926 zilog_t *zilog = dmu_objset_zil(os);
1927
1928 mutex_enter(&zilog->zl_lock);
1929 ASSERT(zilog->zl_suspend != 0);
1930 zilog->zl_suspend--;
1931 mutex_exit(&zilog->zl_lock);
1932 dsl_dataset_long_rele(dmu_objset_ds(os), suspend_tag);
1933 dsl_dataset_rele(dmu_objset_ds(os), suspend_tag);
1934 }
1935
1936 typedef struct zil_replay_arg {
1937 zil_replay_func_t **zr_replay;
1938 void *zr_arg;
1939 boolean_t zr_byteswap;
1940 char *zr_lr;
1941 } zil_replay_arg_t;
1942
1943 static int
1944 zil_replay_error(zilog_t *zilog, lr_t *lr, int error)
1945 {
1946 char name[MAXNAMELEN];
1947
1948 zilog->zl_replaying_seq--; /* didn't actually replay this one */
1949
1950 dmu_objset_name(zilog->zl_os, name);
1951
1952 cmn_err(CE_WARN, "ZFS replay transaction error %d, "
1953 "dataset %s, seq 0x%llx, txtype %llu %s\n", error, name,
1954 (u_longlong_t)lr->lrc_seq,
1955 (u_longlong_t)(lr->lrc_txtype & ~TX_CI),
1956 (lr->lrc_txtype & TX_CI) ? "CI" : "");
1957
1958 return (error);
1959 }
1960
1961 static int
1962 zil_replay_log_record(zilog_t *zilog, lr_t *lr, void *zra, uint64_t claim_txg)
1963 {
1964 zil_replay_arg_t *zr = zra;
1965 const zil_header_t *zh = zilog->zl_header;
1966 uint64_t reclen = lr->lrc_reclen;
1967 uint64_t txtype = lr->lrc_txtype;
1968 int error = 0;
1969
1970 zilog->zl_replaying_seq = lr->lrc_seq;
1971
1972 if (lr->lrc_seq <= zh->zh_replay_seq) /* already replayed */
1973 return (0);
1974
1975 if (lr->lrc_txg < claim_txg) /* already committed */
1976 return (0);
1977
1978 /* Strip case-insensitive bit, still present in log record */
1979 txtype &= ~TX_CI;
1980
1981 if (txtype == 0 || txtype >= TX_MAX_TYPE)
1982 return (zil_replay_error(zilog, lr, EINVAL));
1983
1984 /*
1985 * If this record type can be logged out of order, the object
1986 * (lr_foid) may no longer exist. That's legitimate, not an error.
1987 */
1988 if (TX_OOO(txtype)) {
1989 error = dmu_object_info(zilog->zl_os,
1990 ((lr_ooo_t *)lr)->lr_foid, NULL);
1991 if (error == ENOENT || error == EEXIST)
1992 return (0);
1993 }
1994
1995 /*
1996 * Make a copy of the data so we can revise and extend it.
1997 */
1998 bcopy(lr, zr->zr_lr, reclen);
1999
2000 /*
2001 * If this is a TX_WRITE with a blkptr, suck in the data.
2002 */
2003 if (txtype == TX_WRITE && reclen == sizeof (lr_write_t)) {
2004 error = zil_read_log_data(zilog, (lr_write_t *)lr,
2005 zr->zr_lr + reclen);
2006 if (error != 0)
2007 return (zil_replay_error(zilog, lr, error));
2008 }
2009
2010 /*
2011 * The log block containing this lr may have been byteswapped
2012 * so that we can easily examine common fields like lrc_txtype.
2013 * However, the log is a mix of different record types, and only the
2014 * replay vectors know how to byteswap their records. Therefore, if
2015 * the lr was byteswapped, undo it before invoking the replay vector.
2016 */
2017 if (zr->zr_byteswap)
2018 byteswap_uint64_array(zr->zr_lr, reclen);
2019
2020 /*
2021 * We must now do two things atomically: replay this log record,
2022 * and update the log header sequence number to reflect the fact that
2023 * we did so. At the end of each replay function the sequence number
2024 * is updated if we are in replay mode.
2025 */
2026 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, zr->zr_byteswap);
2027 if (error != 0) {
2028 /*
2029 * The DMU's dnode layer doesn't see removes until the txg
2030 * commits, so a subsequent claim can spuriously fail with
2031 * EEXIST. So if we receive any error we try syncing out
2032 * any removes then retry the transaction. Note that we
2033 * specify B_FALSE for byteswap now, so we don't do it twice.
2034 */
2035 txg_wait_synced(spa_get_dsl(zilog->zl_spa), 0);
2036 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, B_FALSE);
2037 if (error != 0)
2038 return (zil_replay_error(zilog, lr, error));
2039 }
2040 return (0);
2041 }
2042
2043 /* ARGSUSED */
2044 static int
2045 zil_incr_blks(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg)
2046 {
2047 zilog->zl_replay_blks++;
2048
2049 return (0);
2050 }
2051
2052 /*
2053 * If this dataset has a non-empty intent log, replay it and destroy it.
2054 */
2055 void
2056 zil_replay(objset_t *os, void *arg, zil_replay_func_t *replay_func[TX_MAX_TYPE])
2057 {
2058 zilog_t *zilog = dmu_objset_zil(os);
2059 const zil_header_t *zh = zilog->zl_header;
2060 zil_replay_arg_t zr;
2061
2062 if ((zh->zh_flags & ZIL_REPLAY_NEEDED) == 0) {
2063 zil_destroy(zilog, B_TRUE);
2064 return;
2065 }
2066
2067 zr.zr_replay = replay_func;
2068 zr.zr_arg = arg;
2069 zr.zr_byteswap = BP_SHOULD_BYTESWAP(&zh->zh_log);
2070 zr.zr_lr = kmem_alloc(2 * SPA_MAXBLOCKSIZE, KM_SLEEP);
2071
2072 /*
2073 * Wait for in-progress removes to sync before starting replay.
2074 */
2075 txg_wait_synced(zilog->zl_dmu_pool, 0);
2076
2077 zilog->zl_replay = B_TRUE;
2078 zilog->zl_replay_time = ddi_get_lbolt();
2079 ASSERT(zilog->zl_replay_blks == 0);
2080 (void) zil_parse(zilog, zil_incr_blks, zil_replay_log_record, &zr,
2081 zh->zh_claim_txg);
2082 kmem_free(zr.zr_lr, 2 * SPA_MAXBLOCKSIZE);
2083
2084 zil_destroy(zilog, B_FALSE);
2085 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg);
2086 zilog->zl_replay = B_FALSE;
2087 }
2088
2089 boolean_t
2090 zil_replaying(zilog_t *zilog, dmu_tx_t *tx)
2091 {
2092 if (zilog->zl_sync == ZFS_SYNC_DISABLED)
2093 return (B_TRUE);
2094
2095 if (zilog->zl_replay) {
2096 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx);
2097 zilog->zl_replayed_seq[dmu_tx_get_txg(tx) & TXG_MASK] =
2098 zilog->zl_replaying_seq;
2099 return (B_TRUE);
2100 }
2101
2102 return (B_FALSE);
2103 }
2104
2105 /* ARGSUSED */
2106 int
2107 zil_vdev_offline(const char *osname, void *arg)
2108 {
2109 int error;
2110
2111 error = zil_suspend(osname, NULL);
2112 if (error != 0)
2113 return (SET_ERROR(EEXIST));
2114 return (0);
2115 }