zil.c revision 307266
1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21/* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2011, 2015 by Delphix. All rights reserved. 24 * Copyright (c) 2011, 2014 by Delphix. All rights reserved. 25 * Copyright (c) 2014 Integros [integros.com] 26 */ 27 28/* Portions Copyright 2010 Robert Milkowski */ 29 30#include <sys/zfs_context.h> 31#include <sys/spa.h> 32#include <sys/dmu.h> 33#include <sys/zap.h> 34#include <sys/arc.h> 35#include <sys/stat.h> 36#include <sys/resource.h> 37#include <sys/zil.h> 38#include <sys/zil_impl.h> 39#include <sys/dsl_dataset.h> 40#include <sys/vdev_impl.h> 41#include <sys/dmu_tx.h> 42#include <sys/dsl_pool.h> 43 44/* 45 * The zfs intent log (ZIL) saves transaction records of system calls 46 * that change the file system in memory with enough information 47 * to be able to replay them. These are stored in memory until 48 * either the DMU transaction group (txg) commits them to the stable pool 49 * and they can be discarded, or they are flushed to the stable log 50 * (also in the pool) due to a fsync, O_DSYNC or other synchronous 51 * requirement. In the event of a panic or power fail then those log 52 * records (transactions) are replayed. 53 * 54 * There is one ZIL per file system. Its on-disk (pool) format consists 55 * of 3 parts: 56 * 57 * - ZIL header 58 * - ZIL blocks 59 * - ZIL records 60 * 61 * A log record holds a system call transaction. Log blocks can 62 * hold many log records and the blocks are chained together. 63 * Each ZIL block contains a block pointer (blkptr_t) to the next 64 * ZIL block in the chain. The ZIL header points to the first 65 * block in the chain. Note there is not a fixed place in the pool 66 * to hold blocks. They are dynamically allocated and freed as 67 * needed from the blocks available. Figure X shows the ZIL structure: 68 */ 69 70/* 71 * Disable intent logging replay. This global ZIL switch affects all pools. 72 */ 73int zil_replay_disable = 0; 74SYSCTL_DECL(_vfs_zfs); 75TUNABLE_INT("vfs.zfs.zil_replay_disable", &zil_replay_disable); 76SYSCTL_INT(_vfs_zfs, OID_AUTO, zil_replay_disable, CTLFLAG_RW, 77 &zil_replay_disable, 0, "Disable intent logging replay"); 78 79/* 80 * Tunable parameter for debugging or performance analysis. Setting 81 * zfs_nocacheflush will cause corruption on power loss if a volatile 82 * out-of-order write cache is enabled. 83 */ 84boolean_t zfs_nocacheflush = B_FALSE; 85TUNABLE_INT("vfs.zfs.cache_flush_disable", &zfs_nocacheflush); 86SYSCTL_INT(_vfs_zfs, OID_AUTO, cache_flush_disable, CTLFLAG_RDTUN, 87 &zfs_nocacheflush, 0, "Disable cache flush"); 88boolean_t zfs_trim_enabled = B_TRUE; 89SYSCTL_DECL(_vfs_zfs_trim); 90TUNABLE_INT("vfs.zfs.trim.enabled", &zfs_trim_enabled); 91SYSCTL_INT(_vfs_zfs_trim, OID_AUTO, enabled, CTLFLAG_RDTUN, &zfs_trim_enabled, 0, 92 "Enable ZFS TRIM"); 93 94static kmem_cache_t *zil_lwb_cache; 95 96static void zil_async_to_sync(zilog_t *zilog, uint64_t foid); 97 98#define LWB_EMPTY(lwb) ((BP_GET_LSIZE(&lwb->lwb_blk) - \ 99 sizeof (zil_chain_t)) == (lwb->lwb_sz - lwb->lwb_nused)) 100 101 102/* 103 * ziltest is by and large an ugly hack, but very useful in 104 * checking replay without tedious work. 105 * When running ziltest we want to keep all itx's and so maintain 106 * a single list in the zl_itxg[] that uses a high txg: ZILTEST_TXG 107 * We subtract TXG_CONCURRENT_STATES to allow for common code. 108 */ 109#define ZILTEST_TXG (UINT64_MAX - TXG_CONCURRENT_STATES) 110 111static int 112zil_bp_compare(const void *x1, const void *x2) 113{ 114 const dva_t *dva1 = &((zil_bp_node_t *)x1)->zn_dva; 115 const dva_t *dva2 = &((zil_bp_node_t *)x2)->zn_dva; 116 117 if (DVA_GET_VDEV(dva1) < DVA_GET_VDEV(dva2)) 118 return (-1); 119 if (DVA_GET_VDEV(dva1) > DVA_GET_VDEV(dva2)) 120 return (1); 121 122 if (DVA_GET_OFFSET(dva1) < DVA_GET_OFFSET(dva2)) 123 return (-1); 124 if (DVA_GET_OFFSET(dva1) > DVA_GET_OFFSET(dva2)) 125 return (1); 126 127 return (0); 128} 129 130static void 131zil_bp_tree_init(zilog_t *zilog) 132{ 133 avl_create(&zilog->zl_bp_tree, zil_bp_compare, 134 sizeof (zil_bp_node_t), offsetof(zil_bp_node_t, zn_node)); 135} 136 137static void 138zil_bp_tree_fini(zilog_t *zilog) 139{ 140 avl_tree_t *t = &zilog->zl_bp_tree; 141 zil_bp_node_t *zn; 142 void *cookie = NULL; 143 144 while ((zn = avl_destroy_nodes(t, &cookie)) != NULL) 145 kmem_free(zn, sizeof (zil_bp_node_t)); 146 147 avl_destroy(t); 148} 149 150int 151zil_bp_tree_add(zilog_t *zilog, const blkptr_t *bp) 152{ 153 avl_tree_t *t = &zilog->zl_bp_tree; 154 const dva_t *dva; 155 zil_bp_node_t *zn; 156 avl_index_t where; 157 158 if (BP_IS_EMBEDDED(bp)) 159 return (0); 160 161 dva = BP_IDENTITY(bp); 162 163 if (avl_find(t, dva, &where) != NULL) 164 return (SET_ERROR(EEXIST)); 165 166 zn = kmem_alloc(sizeof (zil_bp_node_t), KM_SLEEP); 167 zn->zn_dva = *dva; 168 avl_insert(t, zn, where); 169 170 return (0); 171} 172 173static zil_header_t * 174zil_header_in_syncing_context(zilog_t *zilog) 175{ 176 return ((zil_header_t *)zilog->zl_header); 177} 178 179static void 180zil_init_log_chain(zilog_t *zilog, blkptr_t *bp) 181{ 182 zio_cksum_t *zc = &bp->blk_cksum; 183 184 zc->zc_word[ZIL_ZC_GUID_0] = spa_get_random(-1ULL); 185 zc->zc_word[ZIL_ZC_GUID_1] = spa_get_random(-1ULL); 186 zc->zc_word[ZIL_ZC_OBJSET] = dmu_objset_id(zilog->zl_os); 187 zc->zc_word[ZIL_ZC_SEQ] = 1ULL; 188} 189 190/* 191 * Read a log block and make sure it's valid. 192 */ 193static int 194zil_read_log_block(zilog_t *zilog, const blkptr_t *bp, blkptr_t *nbp, void *dst, 195 char **end) 196{ 197 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL; 198 arc_flags_t aflags = ARC_FLAG_WAIT; 199 arc_buf_t *abuf = NULL; 200 zbookmark_phys_t zb; 201 int error; 202 203 if (zilog->zl_header->zh_claim_txg == 0) 204 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; 205 206 if (!(zilog->zl_header->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) 207 zio_flags |= ZIO_FLAG_SPECULATIVE; 208 209 SET_BOOKMARK(&zb, bp->blk_cksum.zc_word[ZIL_ZC_OBJSET], 210 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]); 211 212 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf, 213 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); 214 215 if (error == 0) { 216 zio_cksum_t cksum = bp->blk_cksum; 217 218 /* 219 * Validate the checksummed log block. 220 * 221 * Sequence numbers should be... sequential. The checksum 222 * verifier for the next block should be bp's checksum plus 1. 223 * 224 * Also check the log chain linkage and size used. 225 */ 226 cksum.zc_word[ZIL_ZC_SEQ]++; 227 228 if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) { 229 zil_chain_t *zilc = abuf->b_data; 230 char *lr = (char *)(zilc + 1); 231 uint64_t len = zilc->zc_nused - sizeof (zil_chain_t); 232 233 if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum, 234 sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk)) { 235 error = SET_ERROR(ECKSUM); 236 } else { 237 ASSERT3U(len, <=, SPA_OLD_MAXBLOCKSIZE); 238 bcopy(lr, dst, len); 239 *end = (char *)dst + len; 240 *nbp = zilc->zc_next_blk; 241 } 242 } else { 243 char *lr = abuf->b_data; 244 uint64_t size = BP_GET_LSIZE(bp); 245 zil_chain_t *zilc = (zil_chain_t *)(lr + size) - 1; 246 247 if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum, 248 sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk) || 249 (zilc->zc_nused > (size - sizeof (*zilc)))) { 250 error = SET_ERROR(ECKSUM); 251 } else { 252 ASSERT3U(zilc->zc_nused, <=, 253 SPA_OLD_MAXBLOCKSIZE); 254 bcopy(lr, dst, zilc->zc_nused); 255 *end = (char *)dst + zilc->zc_nused; 256 *nbp = zilc->zc_next_blk; 257 } 258 } 259 260 arc_buf_destroy(abuf, &abuf); 261 } 262 263 return (error); 264} 265 266/* 267 * Read a TX_WRITE log data block. 268 */ 269static int 270zil_read_log_data(zilog_t *zilog, const lr_write_t *lr, void *wbuf) 271{ 272 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL; 273 const blkptr_t *bp = &lr->lr_blkptr; 274 arc_flags_t aflags = ARC_FLAG_WAIT; 275 arc_buf_t *abuf = NULL; 276 zbookmark_phys_t zb; 277 int error; 278 279 if (BP_IS_HOLE(bp)) { 280 if (wbuf != NULL) 281 bzero(wbuf, MAX(BP_GET_LSIZE(bp), lr->lr_length)); 282 return (0); 283 } 284 285 if (zilog->zl_header->zh_claim_txg == 0) 286 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; 287 288 SET_BOOKMARK(&zb, dmu_objset_id(zilog->zl_os), lr->lr_foid, 289 ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp)); 290 291 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf, 292 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); 293 294 if (error == 0) { 295 if (wbuf != NULL) 296 bcopy(abuf->b_data, wbuf, arc_buf_size(abuf)); 297 arc_buf_destroy(abuf, &abuf); 298 } 299 300 return (error); 301} 302 303/* 304 * Parse the intent log, and call parse_func for each valid record within. 305 */ 306int 307zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func, 308 zil_parse_lr_func_t *parse_lr_func, void *arg, uint64_t txg) 309{ 310 const zil_header_t *zh = zilog->zl_header; 311 boolean_t claimed = !!zh->zh_claim_txg; 312 uint64_t claim_blk_seq = claimed ? zh->zh_claim_blk_seq : UINT64_MAX; 313 uint64_t claim_lr_seq = claimed ? zh->zh_claim_lr_seq : UINT64_MAX; 314 uint64_t max_blk_seq = 0; 315 uint64_t max_lr_seq = 0; 316 uint64_t blk_count = 0; 317 uint64_t lr_count = 0; 318 blkptr_t blk, next_blk; 319 char *lrbuf, *lrp; 320 int error = 0; 321 322 /* 323 * Old logs didn't record the maximum zh_claim_lr_seq. 324 */ 325 if (!(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) 326 claim_lr_seq = UINT64_MAX; 327 328 /* 329 * Starting at the block pointed to by zh_log we read the log chain. 330 * For each block in the chain we strongly check that block to 331 * ensure its validity. We stop when an invalid block is found. 332 * For each block pointer in the chain we call parse_blk_func(). 333 * For each record in each valid block we call parse_lr_func(). 334 * If the log has been claimed, stop if we encounter a sequence 335 * number greater than the highest claimed sequence number. 336 */ 337 lrbuf = zio_buf_alloc(SPA_OLD_MAXBLOCKSIZE); 338 zil_bp_tree_init(zilog); 339 340 for (blk = zh->zh_log; !BP_IS_HOLE(&blk); blk = next_blk) { 341 uint64_t blk_seq = blk.blk_cksum.zc_word[ZIL_ZC_SEQ]; 342 int reclen; 343 char *end; 344 345 if (blk_seq > claim_blk_seq) 346 break; 347 if ((error = parse_blk_func(zilog, &blk, arg, txg)) != 0) 348 break; 349 ASSERT3U(max_blk_seq, <, blk_seq); 350 max_blk_seq = blk_seq; 351 blk_count++; 352 353 if (max_lr_seq == claim_lr_seq && max_blk_seq == claim_blk_seq) 354 break; 355 356 error = zil_read_log_block(zilog, &blk, &next_blk, lrbuf, &end); 357 if (error != 0) 358 break; 359 360 for (lrp = lrbuf; lrp < end; lrp += reclen) { 361 lr_t *lr = (lr_t *)lrp; 362 reclen = lr->lrc_reclen; 363 ASSERT3U(reclen, >=, sizeof (lr_t)); 364 if (lr->lrc_seq > claim_lr_seq) 365 goto done; 366 if ((error = parse_lr_func(zilog, lr, arg, txg)) != 0) 367 goto done; 368 ASSERT3U(max_lr_seq, <, lr->lrc_seq); 369 max_lr_seq = lr->lrc_seq; 370 lr_count++; 371 } 372 } 373done: 374 zilog->zl_parse_error = error; 375 zilog->zl_parse_blk_seq = max_blk_seq; 376 zilog->zl_parse_lr_seq = max_lr_seq; 377 zilog->zl_parse_blk_count = blk_count; 378 zilog->zl_parse_lr_count = lr_count; 379 380 ASSERT(!claimed || !(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID) || 381 (max_blk_seq == claim_blk_seq && max_lr_seq == claim_lr_seq)); 382 383 zil_bp_tree_fini(zilog); 384 zio_buf_free(lrbuf, SPA_OLD_MAXBLOCKSIZE); 385 386 return (error); 387} 388 389static int 390zil_claim_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t first_txg) 391{ 392 /* 393 * Claim log block if not already committed and not already claimed. 394 * If tx == NULL, just verify that the block is claimable. 395 */ 396 if (BP_IS_HOLE(bp) || bp->blk_birth < first_txg || 397 zil_bp_tree_add(zilog, bp) != 0) 398 return (0); 399 400 return (zio_wait(zio_claim(NULL, zilog->zl_spa, 401 tx == NULL ? 0 : first_txg, bp, spa_claim_notify, NULL, 402 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB))); 403} 404 405static int 406zil_claim_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t first_txg) 407{ 408 lr_write_t *lr = (lr_write_t *)lrc; 409 int error; 410 411 if (lrc->lrc_txtype != TX_WRITE) 412 return (0); 413 414 /* 415 * If the block is not readable, don't claim it. This can happen 416 * in normal operation when a log block is written to disk before 417 * some of the dmu_sync() blocks it points to. In this case, the 418 * transaction cannot have been committed to anyone (we would have 419 * waited for all writes to be stable first), so it is semantically 420 * correct to declare this the end of the log. 421 */ 422 if (lr->lr_blkptr.blk_birth >= first_txg && 423 (error = zil_read_log_data(zilog, lr, NULL)) != 0) 424 return (error); 425 return (zil_claim_log_block(zilog, &lr->lr_blkptr, tx, first_txg)); 426} 427 428/* ARGSUSED */ 429static int 430zil_free_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t claim_txg) 431{ 432 zio_free_zil(zilog->zl_spa, dmu_tx_get_txg(tx), bp); 433 434 return (0); 435} 436 437static int 438zil_free_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t claim_txg) 439{ 440 lr_write_t *lr = (lr_write_t *)lrc; 441 blkptr_t *bp = &lr->lr_blkptr; 442 443 /* 444 * If we previously claimed it, we need to free it. 445 */ 446 if (claim_txg != 0 && lrc->lrc_txtype == TX_WRITE && 447 bp->blk_birth >= claim_txg && zil_bp_tree_add(zilog, bp) == 0 && 448 !BP_IS_HOLE(bp)) 449 zio_free(zilog->zl_spa, dmu_tx_get_txg(tx), bp); 450 451 return (0); 452} 453 454static lwb_t * 455zil_alloc_lwb(zilog_t *zilog, blkptr_t *bp, uint64_t txg) 456{ 457 lwb_t *lwb; 458 459 lwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP); 460 lwb->lwb_zilog = zilog; 461 lwb->lwb_blk = *bp; 462 lwb->lwb_buf = zio_buf_alloc(BP_GET_LSIZE(bp)); 463 lwb->lwb_max_txg = txg; 464 lwb->lwb_zio = NULL; 465 lwb->lwb_tx = NULL; 466 if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) { 467 lwb->lwb_nused = sizeof (zil_chain_t); 468 lwb->lwb_sz = BP_GET_LSIZE(bp); 469 } else { 470 lwb->lwb_nused = 0; 471 lwb->lwb_sz = BP_GET_LSIZE(bp) - sizeof (zil_chain_t); 472 } 473 474 mutex_enter(&zilog->zl_lock); 475 list_insert_tail(&zilog->zl_lwb_list, lwb); 476 mutex_exit(&zilog->zl_lock); 477 478 return (lwb); 479} 480 481/* 482 * Called when we create in-memory log transactions so that we know 483 * to cleanup the itxs at the end of spa_sync(). 484 */ 485void 486zilog_dirty(zilog_t *zilog, uint64_t txg) 487{ 488 dsl_pool_t *dp = zilog->zl_dmu_pool; 489 dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os); 490 491 if (ds->ds_is_snapshot) 492 panic("dirtying snapshot!"); 493 494 if (txg_list_add(&dp->dp_dirty_zilogs, zilog, txg)) { 495 /* up the hold count until we can be written out */ 496 dmu_buf_add_ref(ds->ds_dbuf, zilog); 497 } 498} 499 500boolean_t 501zilog_is_dirty(zilog_t *zilog) 502{ 503 dsl_pool_t *dp = zilog->zl_dmu_pool; 504 505 for (int t = 0; t < TXG_SIZE; t++) { 506 if (txg_list_member(&dp->dp_dirty_zilogs, zilog, t)) 507 return (B_TRUE); 508 } 509 return (B_FALSE); 510} 511 512/* 513 * Create an on-disk intent log. 514 */ 515static lwb_t * 516zil_create(zilog_t *zilog) 517{ 518 const zil_header_t *zh = zilog->zl_header; 519 lwb_t *lwb = NULL; 520 uint64_t txg = 0; 521 dmu_tx_t *tx = NULL; 522 blkptr_t blk; 523 int error = 0; 524 525 /* 526 * Wait for any previous destroy to complete. 527 */ 528 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 529 530 ASSERT(zh->zh_claim_txg == 0); 531 ASSERT(zh->zh_replay_seq == 0); 532 533 blk = zh->zh_log; 534 535 /* 536 * Allocate an initial log block if: 537 * - there isn't one already 538 * - the existing block is the wrong endianess 539 */ 540 if (BP_IS_HOLE(&blk) || BP_SHOULD_BYTESWAP(&blk)) { 541 tx = dmu_tx_create(zilog->zl_os); 542 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 543 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 544 txg = dmu_tx_get_txg(tx); 545 546 if (!BP_IS_HOLE(&blk)) { 547 zio_free_zil(zilog->zl_spa, txg, &blk); 548 BP_ZERO(&blk); 549 } 550 551 error = zio_alloc_zil(zilog->zl_spa, txg, &blk, NULL, 552 ZIL_MIN_BLKSZ, zilog->zl_logbias == ZFS_LOGBIAS_LATENCY); 553 554 if (error == 0) 555 zil_init_log_chain(zilog, &blk); 556 } 557 558 /* 559 * Allocate a log write buffer (lwb) for the first log block. 560 */ 561 if (error == 0) 562 lwb = zil_alloc_lwb(zilog, &blk, txg); 563 564 /* 565 * If we just allocated the first log block, commit our transaction 566 * and wait for zil_sync() to stuff the block poiner into zh_log. 567 * (zh is part of the MOS, so we cannot modify it in open context.) 568 */ 569 if (tx != NULL) { 570 dmu_tx_commit(tx); 571 txg_wait_synced(zilog->zl_dmu_pool, txg); 572 } 573 574 ASSERT(bcmp(&blk, &zh->zh_log, sizeof (blk)) == 0); 575 576 return (lwb); 577} 578 579/* 580 * In one tx, free all log blocks and clear the log header. 581 * If keep_first is set, then we're replaying a log with no content. 582 * We want to keep the first block, however, so that the first 583 * synchronous transaction doesn't require a txg_wait_synced() 584 * in zil_create(). We don't need to txg_wait_synced() here either 585 * when keep_first is set, because both zil_create() and zil_destroy() 586 * will wait for any in-progress destroys to complete. 587 */ 588void 589zil_destroy(zilog_t *zilog, boolean_t keep_first) 590{ 591 const zil_header_t *zh = zilog->zl_header; 592 lwb_t *lwb; 593 dmu_tx_t *tx; 594 uint64_t txg; 595 596 /* 597 * Wait for any previous destroy to complete. 598 */ 599 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 600 601 zilog->zl_old_header = *zh; /* debugging aid */ 602 603 if (BP_IS_HOLE(&zh->zh_log)) 604 return; 605 606 tx = dmu_tx_create(zilog->zl_os); 607 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 608 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 609 txg = dmu_tx_get_txg(tx); 610 611 mutex_enter(&zilog->zl_lock); 612 613 ASSERT3U(zilog->zl_destroy_txg, <, txg); 614 zilog->zl_destroy_txg = txg; 615 zilog->zl_keep_first = keep_first; 616 617 if (!list_is_empty(&zilog->zl_lwb_list)) { 618 ASSERT(zh->zh_claim_txg == 0); 619 VERIFY(!keep_first); 620 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { 621 list_remove(&zilog->zl_lwb_list, lwb); 622 if (lwb->lwb_buf != NULL) 623 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 624 zio_free_zil(zilog->zl_spa, txg, &lwb->lwb_blk); 625 kmem_cache_free(zil_lwb_cache, lwb); 626 } 627 } else if (!keep_first) { 628 zil_destroy_sync(zilog, tx); 629 } 630 mutex_exit(&zilog->zl_lock); 631 632 dmu_tx_commit(tx); 633} 634 635void 636zil_destroy_sync(zilog_t *zilog, dmu_tx_t *tx) 637{ 638 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 639 (void) zil_parse(zilog, zil_free_log_block, 640 zil_free_log_record, tx, zilog->zl_header->zh_claim_txg); 641} 642 643int 644zil_claim(dsl_pool_t *dp, dsl_dataset_t *ds, void *txarg) 645{ 646 dmu_tx_t *tx = txarg; 647 uint64_t first_txg = dmu_tx_get_txg(tx); 648 zilog_t *zilog; 649 zil_header_t *zh; 650 objset_t *os; 651 int error; 652 653 error = dmu_objset_own_obj(dp, ds->ds_object, 654 DMU_OST_ANY, B_FALSE, FTAG, &os); 655 if (error != 0) { 656 /* 657 * EBUSY indicates that the objset is inconsistent, in which 658 * case it can not have a ZIL. 659 */ 660 if (error != EBUSY) { 661 cmn_err(CE_WARN, "can't open objset for %llu, error %u", 662 (unsigned long long)ds->ds_object, error); 663 } 664 return (0); 665 } 666 667 zilog = dmu_objset_zil(os); 668 zh = zil_header_in_syncing_context(zilog); 669 670 if (spa_get_log_state(zilog->zl_spa) == SPA_LOG_CLEAR) { 671 if (!BP_IS_HOLE(&zh->zh_log)) 672 zio_free_zil(zilog->zl_spa, first_txg, &zh->zh_log); 673 BP_ZERO(&zh->zh_log); 674 dsl_dataset_dirty(dmu_objset_ds(os), tx); 675 dmu_objset_disown(os, FTAG); 676 return (0); 677 } 678 679 /* 680 * Claim all log blocks if we haven't already done so, and remember 681 * the highest claimed sequence number. This ensures that if we can 682 * read only part of the log now (e.g. due to a missing device), 683 * but we can read the entire log later, we will not try to replay 684 * or destroy beyond the last block we successfully claimed. 685 */ 686 ASSERT3U(zh->zh_claim_txg, <=, first_txg); 687 if (zh->zh_claim_txg == 0 && !BP_IS_HOLE(&zh->zh_log)) { 688 (void) zil_parse(zilog, zil_claim_log_block, 689 zil_claim_log_record, tx, first_txg); 690 zh->zh_claim_txg = first_txg; 691 zh->zh_claim_blk_seq = zilog->zl_parse_blk_seq; 692 zh->zh_claim_lr_seq = zilog->zl_parse_lr_seq; 693 if (zilog->zl_parse_lr_count || zilog->zl_parse_blk_count > 1) 694 zh->zh_flags |= ZIL_REPLAY_NEEDED; 695 zh->zh_flags |= ZIL_CLAIM_LR_SEQ_VALID; 696 dsl_dataset_dirty(dmu_objset_ds(os), tx); 697 } 698 699 ASSERT3U(first_txg, ==, (spa_last_synced_txg(zilog->zl_spa) + 1)); 700 dmu_objset_disown(os, FTAG); 701 return (0); 702} 703 704/* 705 * Check the log by walking the log chain. 706 * Checksum errors are ok as they indicate the end of the chain. 707 * Any other error (no device or read failure) returns an error. 708 */ 709/* ARGSUSED */ 710int 711zil_check_log_chain(dsl_pool_t *dp, dsl_dataset_t *ds, void *tx) 712{ 713 zilog_t *zilog; 714 objset_t *os; 715 blkptr_t *bp; 716 int error; 717 718 ASSERT(tx == NULL); 719 720 error = dmu_objset_from_ds(ds, &os); 721 if (error != 0) { 722 cmn_err(CE_WARN, "can't open objset %llu, error %d", 723 (unsigned long long)ds->ds_object, error); 724 return (0); 725 } 726 727 zilog = dmu_objset_zil(os); 728 bp = (blkptr_t *)&zilog->zl_header->zh_log; 729 730 /* 731 * Check the first block and determine if it's on a log device 732 * which may have been removed or faulted prior to loading this 733 * pool. If so, there's no point in checking the rest of the log 734 * as its content should have already been synced to the pool. 735 */ 736 if (!BP_IS_HOLE(bp)) { 737 vdev_t *vd; 738 boolean_t valid = B_TRUE; 739 740 spa_config_enter(os->os_spa, SCL_STATE, FTAG, RW_READER); 741 vd = vdev_lookup_top(os->os_spa, DVA_GET_VDEV(&bp->blk_dva[0])); 742 if (vd->vdev_islog && vdev_is_dead(vd)) 743 valid = vdev_log_state_valid(vd); 744 spa_config_exit(os->os_spa, SCL_STATE, FTAG); 745 746 if (!valid) 747 return (0); 748 } 749 750 /* 751 * Because tx == NULL, zil_claim_log_block() will not actually claim 752 * any blocks, but just determine whether it is possible to do so. 753 * In addition to checking the log chain, zil_claim_log_block() 754 * will invoke zio_claim() with a done func of spa_claim_notify(), 755 * which will update spa_max_claim_txg. See spa_load() for details. 756 */ 757 error = zil_parse(zilog, zil_claim_log_block, zil_claim_log_record, tx, 758 zilog->zl_header->zh_claim_txg ? -1ULL : spa_first_txg(os->os_spa)); 759 760 return ((error == ECKSUM || error == ENOENT) ? 0 : error); 761} 762 763static int 764zil_vdev_compare(const void *x1, const void *x2) 765{ 766 const uint64_t v1 = ((zil_vdev_node_t *)x1)->zv_vdev; 767 const uint64_t v2 = ((zil_vdev_node_t *)x2)->zv_vdev; 768 769 if (v1 < v2) 770 return (-1); 771 if (v1 > v2) 772 return (1); 773 774 return (0); 775} 776 777void 778zil_add_block(zilog_t *zilog, const blkptr_t *bp) 779{ 780 avl_tree_t *t = &zilog->zl_vdev_tree; 781 avl_index_t where; 782 zil_vdev_node_t *zv, zvsearch; 783 int ndvas = BP_GET_NDVAS(bp); 784 int i; 785 786 if (zfs_nocacheflush) 787 return; 788 789 ASSERT(zilog->zl_writer); 790 791 /* 792 * Even though we're zl_writer, we still need a lock because the 793 * zl_get_data() callbacks may have dmu_sync() done callbacks 794 * that will run concurrently. 795 */ 796 mutex_enter(&zilog->zl_vdev_lock); 797 for (i = 0; i < ndvas; i++) { 798 zvsearch.zv_vdev = DVA_GET_VDEV(&bp->blk_dva[i]); 799 if (avl_find(t, &zvsearch, &where) == NULL) { 800 zv = kmem_alloc(sizeof (*zv), KM_SLEEP); 801 zv->zv_vdev = zvsearch.zv_vdev; 802 avl_insert(t, zv, where); 803 } 804 } 805 mutex_exit(&zilog->zl_vdev_lock); 806} 807 808static void 809zil_flush_vdevs(zilog_t *zilog) 810{ 811 spa_t *spa = zilog->zl_spa; 812 avl_tree_t *t = &zilog->zl_vdev_tree; 813 void *cookie = NULL; 814 zil_vdev_node_t *zv; 815 zio_t *zio; 816 817 ASSERT(zilog->zl_writer); 818 819 /* 820 * We don't need zl_vdev_lock here because we're the zl_writer, 821 * and all zl_get_data() callbacks are done. 822 */ 823 if (avl_numnodes(t) == 0) 824 return; 825 826 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER); 827 828 zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL); 829 830 while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) { 831 vdev_t *vd = vdev_lookup_top(spa, zv->zv_vdev); 832 if (vd != NULL) 833 zio_flush(zio, vd); 834 kmem_free(zv, sizeof (*zv)); 835 } 836 837 /* 838 * Wait for all the flushes to complete. Not all devices actually 839 * support the DKIOCFLUSHWRITECACHE ioctl, so it's OK if it fails. 840 */ 841 (void) zio_wait(zio); 842 843 spa_config_exit(spa, SCL_STATE, FTAG); 844} 845 846/* 847 * Function called when a log block write completes 848 */ 849static void 850zil_lwb_write_done(zio_t *zio) 851{ 852 lwb_t *lwb = zio->io_private; 853 zilog_t *zilog = lwb->lwb_zilog; 854 dmu_tx_t *tx = lwb->lwb_tx; 855 856 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 857 ASSERT(BP_GET_TYPE(zio->io_bp) == DMU_OT_INTENT_LOG); 858 ASSERT(BP_GET_LEVEL(zio->io_bp) == 0); 859 ASSERT(BP_GET_BYTEORDER(zio->io_bp) == ZFS_HOST_BYTEORDER); 860 ASSERT(!BP_IS_GANG(zio->io_bp)); 861 ASSERT(!BP_IS_HOLE(zio->io_bp)); 862 ASSERT(BP_GET_FILL(zio->io_bp) == 0); 863 864 /* 865 * Ensure the lwb buffer pointer is cleared before releasing 866 * the txg. If we have had an allocation failure and 867 * the txg is waiting to sync then we want want zil_sync() 868 * to remove the lwb so that it's not picked up as the next new 869 * one in zil_commit_writer(). zil_sync() will only remove 870 * the lwb if lwb_buf is null. 871 */ 872 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 873 mutex_enter(&zilog->zl_lock); 874 lwb->lwb_buf = NULL; 875 lwb->lwb_tx = NULL; 876 mutex_exit(&zilog->zl_lock); 877 878 /* 879 * Now that we've written this log block, we have a stable pointer 880 * to the next block in the chain, so it's OK to let the txg in 881 * which we allocated the next block sync. 882 */ 883 dmu_tx_commit(tx); 884} 885 886/* 887 * Initialize the io for a log block. 888 */ 889static void 890zil_lwb_write_init(zilog_t *zilog, lwb_t *lwb) 891{ 892 zbookmark_phys_t zb; 893 894 SET_BOOKMARK(&zb, lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_OBJSET], 895 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, 896 lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_SEQ]); 897 898 if (zilog->zl_root_zio == NULL) { 899 zilog->zl_root_zio = zio_root(zilog->zl_spa, NULL, NULL, 900 ZIO_FLAG_CANFAIL); 901 } 902 if (lwb->lwb_zio == NULL) { 903 lwb->lwb_zio = zio_rewrite(zilog->zl_root_zio, zilog->zl_spa, 904 0, &lwb->lwb_blk, lwb->lwb_buf, BP_GET_LSIZE(&lwb->lwb_blk), 905 zil_lwb_write_done, lwb, ZIO_PRIORITY_SYNC_WRITE, 906 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE, &zb); 907 } 908} 909 910/* 911 * Define a limited set of intent log block sizes. 912 * 913 * These must be a multiple of 4KB. Note only the amount used (again 914 * aligned to 4KB) actually gets written. However, we can't always just 915 * allocate SPA_OLD_MAXBLOCKSIZE as the slog space could be exhausted. 916 */ 917uint64_t zil_block_buckets[] = { 918 4096, /* non TX_WRITE */ 919 8192+4096, /* data base */ 920 32*1024 + 4096, /* NFS writes */ 921 UINT64_MAX 922}; 923 924/* 925 * Use the slog as long as the logbias is 'latency' and the current commit size 926 * is less than the limit or the total list size is less than 2X the limit. 927 * Limit checking is disabled by setting zil_slog_limit to UINT64_MAX. 928 */ 929uint64_t zil_slog_limit = 1024 * 1024; 930#define USE_SLOG(zilog) (((zilog)->zl_logbias == ZFS_LOGBIAS_LATENCY) && \ 931 (((zilog)->zl_cur_used < zil_slog_limit) || \ 932 ((zilog)->zl_itx_list_sz < (zil_slog_limit << 1)))) 933 934/* 935 * Start a log block write and advance to the next log block. 936 * Calls are serialized. 937 */ 938static lwb_t * 939zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb) 940{ 941 lwb_t *nlwb = NULL; 942 zil_chain_t *zilc; 943 spa_t *spa = zilog->zl_spa; 944 blkptr_t *bp; 945 dmu_tx_t *tx; 946 uint64_t txg; 947 uint64_t zil_blksz, wsz; 948 int i, error; 949 950 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) { 951 zilc = (zil_chain_t *)lwb->lwb_buf; 952 bp = &zilc->zc_next_blk; 953 } else { 954 zilc = (zil_chain_t *)(lwb->lwb_buf + lwb->lwb_sz); 955 bp = &zilc->zc_next_blk; 956 } 957 958 ASSERT(lwb->lwb_nused <= lwb->lwb_sz); 959 960 /* 961 * Allocate the next block and save its address in this block 962 * before writing it in order to establish the log chain. 963 * Note that if the allocation of nlwb synced before we wrote 964 * the block that points at it (lwb), we'd leak it if we crashed. 965 * Therefore, we don't do dmu_tx_commit() until zil_lwb_write_done(). 966 * We dirty the dataset to ensure that zil_sync() will be called 967 * to clean up in the event of allocation failure or I/O failure. 968 */ 969 tx = dmu_tx_create(zilog->zl_os); 970 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 971 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 972 txg = dmu_tx_get_txg(tx); 973 974 lwb->lwb_tx = tx; 975 976 /* 977 * Log blocks are pre-allocated. Here we select the size of the next 978 * block, based on size used in the last block. 979 * - first find the smallest bucket that will fit the block from a 980 * limited set of block sizes. This is because it's faster to write 981 * blocks allocated from the same metaslab as they are adjacent or 982 * close. 983 * - next find the maximum from the new suggested size and an array of 984 * previous sizes. This lessens a picket fence effect of wrongly 985 * guesssing the size if we have a stream of say 2k, 64k, 2k, 64k 986 * requests. 987 * 988 * Note we only write what is used, but we can't just allocate 989 * the maximum block size because we can exhaust the available 990 * pool log space. 991 */ 992 zil_blksz = zilog->zl_cur_used + sizeof (zil_chain_t); 993 for (i = 0; zil_blksz > zil_block_buckets[i]; i++) 994 continue; 995 zil_blksz = zil_block_buckets[i]; 996 if (zil_blksz == UINT64_MAX) 997 zil_blksz = SPA_OLD_MAXBLOCKSIZE; 998 zilog->zl_prev_blks[zilog->zl_prev_rotor] = zil_blksz; 999 for (i = 0; i < ZIL_PREV_BLKS; i++) 1000 zil_blksz = MAX(zil_blksz, zilog->zl_prev_blks[i]); 1001 zilog->zl_prev_rotor = (zilog->zl_prev_rotor + 1) & (ZIL_PREV_BLKS - 1); 1002 1003 BP_ZERO(bp); 1004 /* pass the old blkptr in order to spread log blocks across devs */ 1005 error = zio_alloc_zil(spa, txg, bp, &lwb->lwb_blk, zil_blksz, 1006 USE_SLOG(zilog)); 1007 if (error == 0) { 1008 ASSERT3U(bp->blk_birth, ==, txg); 1009 bp->blk_cksum = lwb->lwb_blk.blk_cksum; 1010 bp->blk_cksum.zc_word[ZIL_ZC_SEQ]++; 1011 1012 /* 1013 * Allocate a new log write buffer (lwb). 1014 */ 1015 nlwb = zil_alloc_lwb(zilog, bp, txg); 1016 1017 /* Record the block for later vdev flushing */ 1018 zil_add_block(zilog, &lwb->lwb_blk); 1019 } 1020 1021 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) { 1022 /* For Slim ZIL only write what is used. */ 1023 wsz = P2ROUNDUP_TYPED(lwb->lwb_nused, ZIL_MIN_BLKSZ, uint64_t); 1024 ASSERT3U(wsz, <=, lwb->lwb_sz); 1025 zio_shrink(lwb->lwb_zio, wsz); 1026 1027 } else { 1028 wsz = lwb->lwb_sz; 1029 } 1030 1031 zilc->zc_pad = 0; 1032 zilc->zc_nused = lwb->lwb_nused; 1033 zilc->zc_eck.zec_cksum = lwb->lwb_blk.blk_cksum; 1034 1035 /* 1036 * clear unused data for security 1037 */ 1038 bzero(lwb->lwb_buf + lwb->lwb_nused, wsz - lwb->lwb_nused); 1039 1040 zio_nowait(lwb->lwb_zio); /* Kick off the write for the old log block */ 1041 1042 /* 1043 * If there was an allocation failure then nlwb will be null which 1044 * forces a txg_wait_synced(). 1045 */ 1046 return (nlwb); 1047} 1048 1049static lwb_t * 1050zil_lwb_commit(zilog_t *zilog, itx_t *itx, lwb_t *lwb) 1051{ 1052 lr_t *lrc = &itx->itx_lr; /* common log record */ 1053 lr_write_t *lrw = (lr_write_t *)lrc; 1054 char *lr_buf; 1055 uint64_t txg = lrc->lrc_txg; 1056 uint64_t reclen = lrc->lrc_reclen; 1057 uint64_t dlen = 0; 1058 1059 if (lwb == NULL) 1060 return (NULL); 1061 1062 ASSERT(lwb->lwb_buf != NULL); 1063 ASSERT(zilog_is_dirty(zilog) || 1064 spa_freeze_txg(zilog->zl_spa) != UINT64_MAX); 1065 1066 if (lrc->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY) 1067 dlen = P2ROUNDUP_TYPED( 1068 lrw->lr_length, sizeof (uint64_t), uint64_t); 1069 1070 zilog->zl_cur_used += (reclen + dlen); 1071 1072 zil_lwb_write_init(zilog, lwb); 1073 1074 /* 1075 * If this record won't fit in the current log block, start a new one. 1076 */ 1077 if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) { 1078 lwb = zil_lwb_write_start(zilog, lwb); 1079 if (lwb == NULL) 1080 return (NULL); 1081 zil_lwb_write_init(zilog, lwb); 1082 ASSERT(LWB_EMPTY(lwb)); 1083 if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) { 1084 txg_wait_synced(zilog->zl_dmu_pool, txg); 1085 return (lwb); 1086 } 1087 } 1088 1089 lr_buf = lwb->lwb_buf + lwb->lwb_nused; 1090 bcopy(lrc, lr_buf, reclen); 1091 lrc = (lr_t *)lr_buf; 1092 lrw = (lr_write_t *)lrc; 1093 1094 /* 1095 * If it's a write, fetch the data or get its blkptr as appropriate. 1096 */ 1097 if (lrc->lrc_txtype == TX_WRITE) { 1098 if (txg > spa_freeze_txg(zilog->zl_spa)) 1099 txg_wait_synced(zilog->zl_dmu_pool, txg); 1100 if (itx->itx_wr_state != WR_COPIED) { 1101 char *dbuf; 1102 int error; 1103 1104 if (dlen) { 1105 ASSERT(itx->itx_wr_state == WR_NEED_COPY); 1106 dbuf = lr_buf + reclen; 1107 lrw->lr_common.lrc_reclen += dlen; 1108 } else { 1109 ASSERT(itx->itx_wr_state == WR_INDIRECT); 1110 dbuf = NULL; 1111 } 1112 error = zilog->zl_get_data( 1113 itx->itx_private, lrw, dbuf, lwb->lwb_zio); 1114 if (error == EIO) { 1115 txg_wait_synced(zilog->zl_dmu_pool, txg); 1116 return (lwb); 1117 } 1118 if (error != 0) { 1119 ASSERT(error == ENOENT || error == EEXIST || 1120 error == EALREADY); 1121 return (lwb); 1122 } 1123 } 1124 } 1125 1126 /* 1127 * We're actually making an entry, so update lrc_seq to be the 1128 * log record sequence number. Note that this is generally not 1129 * equal to the itx sequence number because not all transactions 1130 * are synchronous, and sometimes spa_sync() gets there first. 1131 */ 1132 lrc->lrc_seq = ++zilog->zl_lr_seq; /* we are single threaded */ 1133 lwb->lwb_nused += reclen + dlen; 1134 lwb->lwb_max_txg = MAX(lwb->lwb_max_txg, txg); 1135 ASSERT3U(lwb->lwb_nused, <=, lwb->lwb_sz); 1136 ASSERT0(P2PHASE(lwb->lwb_nused, sizeof (uint64_t))); 1137 1138 return (lwb); 1139} 1140 1141itx_t * 1142zil_itx_create(uint64_t txtype, size_t lrsize) 1143{ 1144 itx_t *itx; 1145 1146 lrsize = P2ROUNDUP_TYPED(lrsize, sizeof (uint64_t), size_t); 1147 1148 itx = kmem_alloc(offsetof(itx_t, itx_lr) + lrsize, KM_SLEEP); 1149 itx->itx_lr.lrc_txtype = txtype; 1150 itx->itx_lr.lrc_reclen = lrsize; 1151 itx->itx_sod = lrsize; /* if write & WR_NEED_COPY will be increased */ 1152 itx->itx_lr.lrc_seq = 0; /* defensive */ 1153 itx->itx_sync = B_TRUE; /* default is synchronous */ 1154 1155 return (itx); 1156} 1157 1158void 1159zil_itx_destroy(itx_t *itx) 1160{ 1161 kmem_free(itx, offsetof(itx_t, itx_lr) + itx->itx_lr.lrc_reclen); 1162} 1163 1164/* 1165 * Free up the sync and async itxs. The itxs_t has already been detached 1166 * so no locks are needed. 1167 */ 1168static void 1169zil_itxg_clean(itxs_t *itxs) 1170{ 1171 itx_t *itx; 1172 list_t *list; 1173 avl_tree_t *t; 1174 void *cookie; 1175 itx_async_node_t *ian; 1176 1177 list = &itxs->i_sync_list; 1178 while ((itx = list_head(list)) != NULL) { 1179 list_remove(list, itx); 1180 kmem_free(itx, offsetof(itx_t, itx_lr) + 1181 itx->itx_lr.lrc_reclen); 1182 } 1183 1184 cookie = NULL; 1185 t = &itxs->i_async_tree; 1186 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) { 1187 list = &ian->ia_list; 1188 while ((itx = list_head(list)) != NULL) { 1189 list_remove(list, itx); 1190 kmem_free(itx, offsetof(itx_t, itx_lr) + 1191 itx->itx_lr.lrc_reclen); 1192 } 1193 list_destroy(list); 1194 kmem_free(ian, sizeof (itx_async_node_t)); 1195 } 1196 avl_destroy(t); 1197 1198 kmem_free(itxs, sizeof (itxs_t)); 1199} 1200 1201static int 1202zil_aitx_compare(const void *x1, const void *x2) 1203{ 1204 const uint64_t o1 = ((itx_async_node_t *)x1)->ia_foid; 1205 const uint64_t o2 = ((itx_async_node_t *)x2)->ia_foid; 1206 1207 if (o1 < o2) 1208 return (-1); 1209 if (o1 > o2) 1210 return (1); 1211 1212 return (0); 1213} 1214 1215/* 1216 * Remove all async itx with the given oid. 1217 */ 1218static void 1219zil_remove_async(zilog_t *zilog, uint64_t oid) 1220{ 1221 uint64_t otxg, txg; 1222 itx_async_node_t *ian; 1223 avl_tree_t *t; 1224 avl_index_t where; 1225 list_t clean_list; 1226 itx_t *itx; 1227 1228 ASSERT(oid != 0); 1229 list_create(&clean_list, sizeof (itx_t), offsetof(itx_t, itx_node)); 1230 1231 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1232 otxg = ZILTEST_TXG; 1233 else 1234 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1235 1236 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1237 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1238 1239 mutex_enter(&itxg->itxg_lock); 1240 if (itxg->itxg_txg != txg) { 1241 mutex_exit(&itxg->itxg_lock); 1242 continue; 1243 } 1244 1245 /* 1246 * Locate the object node and append its list. 1247 */ 1248 t = &itxg->itxg_itxs->i_async_tree; 1249 ian = avl_find(t, &oid, &where); 1250 if (ian != NULL) 1251 list_move_tail(&clean_list, &ian->ia_list); 1252 mutex_exit(&itxg->itxg_lock); 1253 } 1254 while ((itx = list_head(&clean_list)) != NULL) { 1255 list_remove(&clean_list, itx); 1256 kmem_free(itx, offsetof(itx_t, itx_lr) + 1257 itx->itx_lr.lrc_reclen); 1258 } 1259 list_destroy(&clean_list); 1260} 1261 1262void 1263zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx) 1264{ 1265 uint64_t txg; 1266 itxg_t *itxg; 1267 itxs_t *itxs, *clean = NULL; 1268 1269 /* 1270 * Object ids can be re-instantiated in the next txg so 1271 * remove any async transactions to avoid future leaks. 1272 * This can happen if a fsync occurs on the re-instantiated 1273 * object for a WR_INDIRECT or WR_NEED_COPY write, which gets 1274 * the new file data and flushes a write record for the old object. 1275 */ 1276 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_REMOVE) 1277 zil_remove_async(zilog, itx->itx_oid); 1278 1279 /* 1280 * Ensure the data of a renamed file is committed before the rename. 1281 */ 1282 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_RENAME) 1283 zil_async_to_sync(zilog, itx->itx_oid); 1284 1285 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) 1286 txg = ZILTEST_TXG; 1287 else 1288 txg = dmu_tx_get_txg(tx); 1289 1290 itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1291 mutex_enter(&itxg->itxg_lock); 1292 itxs = itxg->itxg_itxs; 1293 if (itxg->itxg_txg != txg) { 1294 if (itxs != NULL) { 1295 /* 1296 * The zil_clean callback hasn't got around to cleaning 1297 * this itxg. Save the itxs for release below. 1298 * This should be rare. 1299 */ 1300 atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod); 1301 itxg->itxg_sod = 0; 1302 clean = itxg->itxg_itxs; 1303 } 1304 ASSERT(itxg->itxg_sod == 0); 1305 itxg->itxg_txg = txg; 1306 itxs = itxg->itxg_itxs = kmem_zalloc(sizeof (itxs_t), KM_SLEEP); 1307 1308 list_create(&itxs->i_sync_list, sizeof (itx_t), 1309 offsetof(itx_t, itx_node)); 1310 avl_create(&itxs->i_async_tree, zil_aitx_compare, 1311 sizeof (itx_async_node_t), 1312 offsetof(itx_async_node_t, ia_node)); 1313 } 1314 if (itx->itx_sync) { 1315 list_insert_tail(&itxs->i_sync_list, itx); 1316 atomic_add_64(&zilog->zl_itx_list_sz, itx->itx_sod); 1317 itxg->itxg_sod += itx->itx_sod; 1318 } else { 1319 avl_tree_t *t = &itxs->i_async_tree; 1320 uint64_t foid = ((lr_ooo_t *)&itx->itx_lr)->lr_foid; 1321 itx_async_node_t *ian; 1322 avl_index_t where; 1323 1324 ian = avl_find(t, &foid, &where); 1325 if (ian == NULL) { 1326 ian = kmem_alloc(sizeof (itx_async_node_t), KM_SLEEP); 1327 list_create(&ian->ia_list, sizeof (itx_t), 1328 offsetof(itx_t, itx_node)); 1329 ian->ia_foid = foid; 1330 avl_insert(t, ian, where); 1331 } 1332 list_insert_tail(&ian->ia_list, itx); 1333 } 1334 1335 itx->itx_lr.lrc_txg = dmu_tx_get_txg(tx); 1336 zilog_dirty(zilog, txg); 1337 mutex_exit(&itxg->itxg_lock); 1338 1339 /* Release the old itxs now we've dropped the lock */ 1340 if (clean != NULL) 1341 zil_itxg_clean(clean); 1342} 1343 1344/* 1345 * If there are any in-memory intent log transactions which have now been 1346 * synced then start up a taskq to free them. We should only do this after we 1347 * have written out the uberblocks (i.e. txg has been comitted) so that 1348 * don't inadvertently clean out in-memory log records that would be required 1349 * by zil_commit(). 1350 */ 1351void 1352zil_clean(zilog_t *zilog, uint64_t synced_txg) 1353{ 1354 itxg_t *itxg = &zilog->zl_itxg[synced_txg & TXG_MASK]; 1355 itxs_t *clean_me; 1356 1357 mutex_enter(&itxg->itxg_lock); 1358 if (itxg->itxg_itxs == NULL || itxg->itxg_txg == ZILTEST_TXG) { 1359 mutex_exit(&itxg->itxg_lock); 1360 return; 1361 } 1362 ASSERT3U(itxg->itxg_txg, <=, synced_txg); 1363 ASSERT(itxg->itxg_txg != 0); 1364 ASSERT(zilog->zl_clean_taskq != NULL); 1365 atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod); 1366 itxg->itxg_sod = 0; 1367 clean_me = itxg->itxg_itxs; 1368 itxg->itxg_itxs = NULL; 1369 itxg->itxg_txg = 0; 1370 mutex_exit(&itxg->itxg_lock); 1371 /* 1372 * Preferably start a task queue to free up the old itxs but 1373 * if taskq_dispatch can't allocate resources to do that then 1374 * free it in-line. This should be rare. Note, using TQ_SLEEP 1375 * created a bad performance problem. 1376 */ 1377 if (taskq_dispatch(zilog->zl_clean_taskq, 1378 (void (*)(void *))zil_itxg_clean, clean_me, TQ_NOSLEEP) == 0) 1379 zil_itxg_clean(clean_me); 1380} 1381 1382/* 1383 * Get the list of itxs to commit into zl_itx_commit_list. 1384 */ 1385static void 1386zil_get_commit_list(zilog_t *zilog) 1387{ 1388 uint64_t otxg, txg; 1389 list_t *commit_list = &zilog->zl_itx_commit_list; 1390 uint64_t push_sod = 0; 1391 1392 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1393 otxg = ZILTEST_TXG; 1394 else 1395 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1396 1397 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1398 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1399 1400 mutex_enter(&itxg->itxg_lock); 1401 if (itxg->itxg_txg != txg) { 1402 mutex_exit(&itxg->itxg_lock); 1403 continue; 1404 } 1405 1406 list_move_tail(commit_list, &itxg->itxg_itxs->i_sync_list); 1407 push_sod += itxg->itxg_sod; 1408 itxg->itxg_sod = 0; 1409 1410 mutex_exit(&itxg->itxg_lock); 1411 } 1412 atomic_add_64(&zilog->zl_itx_list_sz, -push_sod); 1413} 1414 1415/* 1416 * Move the async itxs for a specified object to commit into sync lists. 1417 */ 1418static void 1419zil_async_to_sync(zilog_t *zilog, uint64_t foid) 1420{ 1421 uint64_t otxg, txg; 1422 itx_async_node_t *ian; 1423 avl_tree_t *t; 1424 avl_index_t where; 1425 1426 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1427 otxg = ZILTEST_TXG; 1428 else 1429 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1430 1431 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1432 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1433 1434 mutex_enter(&itxg->itxg_lock); 1435 if (itxg->itxg_txg != txg) { 1436 mutex_exit(&itxg->itxg_lock); 1437 continue; 1438 } 1439 1440 /* 1441 * If a foid is specified then find that node and append its 1442 * list. Otherwise walk the tree appending all the lists 1443 * to the sync list. We add to the end rather than the 1444 * beginning to ensure the create has happened. 1445 */ 1446 t = &itxg->itxg_itxs->i_async_tree; 1447 if (foid != 0) { 1448 ian = avl_find(t, &foid, &where); 1449 if (ian != NULL) { 1450 list_move_tail(&itxg->itxg_itxs->i_sync_list, 1451 &ian->ia_list); 1452 } 1453 } else { 1454 void *cookie = NULL; 1455 1456 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) { 1457 list_move_tail(&itxg->itxg_itxs->i_sync_list, 1458 &ian->ia_list); 1459 list_destroy(&ian->ia_list); 1460 kmem_free(ian, sizeof (itx_async_node_t)); 1461 } 1462 } 1463 mutex_exit(&itxg->itxg_lock); 1464 } 1465} 1466 1467static void 1468zil_commit_writer(zilog_t *zilog) 1469{ 1470 uint64_t txg; 1471 itx_t *itx; 1472 lwb_t *lwb; 1473 spa_t *spa = zilog->zl_spa; 1474 int error = 0; 1475 1476 ASSERT(zilog->zl_root_zio == NULL); 1477 1478 mutex_exit(&zilog->zl_lock); 1479 1480 zil_get_commit_list(zilog); 1481 1482 /* 1483 * Return if there's nothing to commit before we dirty the fs by 1484 * calling zil_create(). 1485 */ 1486 if (list_head(&zilog->zl_itx_commit_list) == NULL) { 1487 mutex_enter(&zilog->zl_lock); 1488 return; 1489 } 1490 1491 if (zilog->zl_suspend) { 1492 lwb = NULL; 1493 } else { 1494 lwb = list_tail(&zilog->zl_lwb_list); 1495 if (lwb == NULL) 1496 lwb = zil_create(zilog); 1497 } 1498 1499 DTRACE_PROBE1(zil__cw1, zilog_t *, zilog); 1500 while (itx = list_head(&zilog->zl_itx_commit_list)) { 1501 txg = itx->itx_lr.lrc_txg; 1502 ASSERT(txg); 1503 1504 if (txg > spa_last_synced_txg(spa) || txg > spa_freeze_txg(spa)) 1505 lwb = zil_lwb_commit(zilog, itx, lwb); 1506 list_remove(&zilog->zl_itx_commit_list, itx); 1507 kmem_free(itx, offsetof(itx_t, itx_lr) 1508 + itx->itx_lr.lrc_reclen); 1509 } 1510 DTRACE_PROBE1(zil__cw2, zilog_t *, zilog); 1511 1512 /* write the last block out */ 1513 if (lwb != NULL && lwb->lwb_zio != NULL) 1514 lwb = zil_lwb_write_start(zilog, lwb); 1515 1516 zilog->zl_cur_used = 0; 1517 1518 /* 1519 * Wait if necessary for the log blocks to be on stable storage. 1520 */ 1521 if (zilog->zl_root_zio) { 1522 error = zio_wait(zilog->zl_root_zio); 1523 zilog->zl_root_zio = NULL; 1524 zil_flush_vdevs(zilog); 1525 } 1526 1527 if (error || lwb == NULL) 1528 txg_wait_synced(zilog->zl_dmu_pool, 0); 1529 1530 mutex_enter(&zilog->zl_lock); 1531 1532 /* 1533 * Remember the highest committed log sequence number for ztest. 1534 * We only update this value when all the log writes succeeded, 1535 * because ztest wants to ASSERT that it got the whole log chain. 1536 */ 1537 if (error == 0 && lwb != NULL) 1538 zilog->zl_commit_lr_seq = zilog->zl_lr_seq; 1539} 1540 1541/* 1542 * Commit zfs transactions to stable storage. 1543 * If foid is 0 push out all transactions, otherwise push only those 1544 * for that object or might reference that object. 1545 * 1546 * itxs are committed in batches. In a heavily stressed zil there will be 1547 * a commit writer thread who is writing out a bunch of itxs to the log 1548 * for a set of committing threads (cthreads) in the same batch as the writer. 1549 * Those cthreads are all waiting on the same cv for that batch. 1550 * 1551 * There will also be a different and growing batch of threads that are 1552 * waiting to commit (qthreads). When the committing batch completes 1553 * a transition occurs such that the cthreads exit and the qthreads become 1554 * cthreads. One of the new cthreads becomes the writer thread for the 1555 * batch. Any new threads arriving become new qthreads. 1556 * 1557 * Only 2 condition variables are needed and there's no transition 1558 * between the two cvs needed. They just flip-flop between qthreads 1559 * and cthreads. 1560 * 1561 * Using this scheme we can efficiently wakeup up only those threads 1562 * that have been committed. 1563 */ 1564void 1565zil_commit(zilog_t *zilog, uint64_t foid) 1566{ 1567 uint64_t mybatch; 1568 1569 if (zilog->zl_sync == ZFS_SYNC_DISABLED) 1570 return; 1571 1572 /* move the async itxs for the foid to the sync queues */ 1573 zil_async_to_sync(zilog, foid); 1574 1575 mutex_enter(&zilog->zl_lock); 1576 mybatch = zilog->zl_next_batch; 1577 while (zilog->zl_writer) { 1578 cv_wait(&zilog->zl_cv_batch[mybatch & 1], &zilog->zl_lock); 1579 if (mybatch <= zilog->zl_com_batch) { 1580 mutex_exit(&zilog->zl_lock); 1581 return; 1582 } 1583 } 1584 1585 zilog->zl_next_batch++; 1586 zilog->zl_writer = B_TRUE; 1587 zil_commit_writer(zilog); 1588 zilog->zl_com_batch = mybatch; 1589 zilog->zl_writer = B_FALSE; 1590 mutex_exit(&zilog->zl_lock); 1591 1592 /* wake up one thread to become the next writer */ 1593 cv_signal(&zilog->zl_cv_batch[(mybatch+1) & 1]); 1594 1595 /* wake up all threads waiting for this batch to be committed */ 1596 cv_broadcast(&zilog->zl_cv_batch[mybatch & 1]); 1597} 1598 1599/* 1600 * Called in syncing context to free committed log blocks and update log header. 1601 */ 1602void 1603zil_sync(zilog_t *zilog, dmu_tx_t *tx) 1604{ 1605 zil_header_t *zh = zil_header_in_syncing_context(zilog); 1606 uint64_t txg = dmu_tx_get_txg(tx); 1607 spa_t *spa = zilog->zl_spa; 1608 uint64_t *replayed_seq = &zilog->zl_replayed_seq[txg & TXG_MASK]; 1609 lwb_t *lwb; 1610 1611 /* 1612 * We don't zero out zl_destroy_txg, so make sure we don't try 1613 * to destroy it twice. 1614 */ 1615 if (spa_sync_pass(spa) != 1) 1616 return; 1617 1618 mutex_enter(&zilog->zl_lock); 1619 1620 ASSERT(zilog->zl_stop_sync == 0); 1621 1622 if (*replayed_seq != 0) { 1623 ASSERT(zh->zh_replay_seq < *replayed_seq); 1624 zh->zh_replay_seq = *replayed_seq; 1625 *replayed_seq = 0; 1626 } 1627 1628 if (zilog->zl_destroy_txg == txg) { 1629 blkptr_t blk = zh->zh_log; 1630 1631 ASSERT(list_head(&zilog->zl_lwb_list) == NULL); 1632 1633 bzero(zh, sizeof (zil_header_t)); 1634 bzero(zilog->zl_replayed_seq, sizeof (zilog->zl_replayed_seq)); 1635 1636 if (zilog->zl_keep_first) { 1637 /* 1638 * If this block was part of log chain that couldn't 1639 * be claimed because a device was missing during 1640 * zil_claim(), but that device later returns, 1641 * then this block could erroneously appear valid. 1642 * To guard against this, assign a new GUID to the new 1643 * log chain so it doesn't matter what blk points to. 1644 */ 1645 zil_init_log_chain(zilog, &blk); 1646 zh->zh_log = blk; 1647 } 1648 } 1649 1650 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { 1651 zh->zh_log = lwb->lwb_blk; 1652 if (lwb->lwb_buf != NULL || lwb->lwb_max_txg > txg) 1653 break; 1654 list_remove(&zilog->zl_lwb_list, lwb); 1655 zio_free_zil(spa, txg, &lwb->lwb_blk); 1656 kmem_cache_free(zil_lwb_cache, lwb); 1657 1658 /* 1659 * If we don't have anything left in the lwb list then 1660 * we've had an allocation failure and we need to zero 1661 * out the zil_header blkptr so that we don't end 1662 * up freeing the same block twice. 1663 */ 1664 if (list_head(&zilog->zl_lwb_list) == NULL) 1665 BP_ZERO(&zh->zh_log); 1666 } 1667 mutex_exit(&zilog->zl_lock); 1668} 1669 1670void 1671zil_init(void) 1672{ 1673 zil_lwb_cache = kmem_cache_create("zil_lwb_cache", 1674 sizeof (struct lwb), 0, NULL, NULL, NULL, NULL, NULL, 0); 1675} 1676 1677void 1678zil_fini(void) 1679{ 1680 kmem_cache_destroy(zil_lwb_cache); 1681} 1682 1683void 1684zil_set_sync(zilog_t *zilog, uint64_t sync) 1685{ 1686 zilog->zl_sync = sync; 1687} 1688 1689void 1690zil_set_logbias(zilog_t *zilog, uint64_t logbias) 1691{ 1692 zilog->zl_logbias = logbias; 1693} 1694 1695zilog_t * 1696zil_alloc(objset_t *os, zil_header_t *zh_phys) 1697{ 1698 zilog_t *zilog; 1699 1700 zilog = kmem_zalloc(sizeof (zilog_t), KM_SLEEP); 1701 1702 zilog->zl_header = zh_phys; 1703 zilog->zl_os = os; 1704 zilog->zl_spa = dmu_objset_spa(os); 1705 zilog->zl_dmu_pool = dmu_objset_pool(os); 1706 zilog->zl_destroy_txg = TXG_INITIAL - 1; 1707 zilog->zl_logbias = dmu_objset_logbias(os); 1708 zilog->zl_sync = dmu_objset_syncprop(os); 1709 zilog->zl_next_batch = 1; 1710 1711 mutex_init(&zilog->zl_lock, NULL, MUTEX_DEFAULT, NULL); 1712 1713 for (int i = 0; i < TXG_SIZE; i++) { 1714 mutex_init(&zilog->zl_itxg[i].itxg_lock, NULL, 1715 MUTEX_DEFAULT, NULL); 1716 } 1717 1718 list_create(&zilog->zl_lwb_list, sizeof (lwb_t), 1719 offsetof(lwb_t, lwb_node)); 1720 1721 list_create(&zilog->zl_itx_commit_list, sizeof (itx_t), 1722 offsetof(itx_t, itx_node)); 1723 1724 mutex_init(&zilog->zl_vdev_lock, NULL, MUTEX_DEFAULT, NULL); 1725 1726 avl_create(&zilog->zl_vdev_tree, zil_vdev_compare, 1727 sizeof (zil_vdev_node_t), offsetof(zil_vdev_node_t, zv_node)); 1728 1729 cv_init(&zilog->zl_cv_writer, NULL, CV_DEFAULT, NULL); 1730 cv_init(&zilog->zl_cv_suspend, NULL, CV_DEFAULT, NULL); 1731 cv_init(&zilog->zl_cv_batch[0], NULL, CV_DEFAULT, NULL); 1732 cv_init(&zilog->zl_cv_batch[1], NULL, CV_DEFAULT, NULL); 1733 1734 return (zilog); 1735} 1736 1737void 1738zil_free(zilog_t *zilog) 1739{ 1740 zilog->zl_stop_sync = 1; 1741 1742 ASSERT0(zilog->zl_suspend); 1743 ASSERT0(zilog->zl_suspending); 1744 1745 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 1746 list_destroy(&zilog->zl_lwb_list); 1747 1748 avl_destroy(&zilog->zl_vdev_tree); 1749 mutex_destroy(&zilog->zl_vdev_lock); 1750 1751 ASSERT(list_is_empty(&zilog->zl_itx_commit_list)); 1752 list_destroy(&zilog->zl_itx_commit_list); 1753 1754 for (int i = 0; i < TXG_SIZE; i++) { 1755 /* 1756 * It's possible for an itx to be generated that doesn't dirty 1757 * a txg (e.g. ztest TX_TRUNCATE). So there's no zil_clean() 1758 * callback to remove the entry. We remove those here. 1759 * 1760 * Also free up the ziltest itxs. 1761 */ 1762 if (zilog->zl_itxg[i].itxg_itxs) 1763 zil_itxg_clean(zilog->zl_itxg[i].itxg_itxs); 1764 mutex_destroy(&zilog->zl_itxg[i].itxg_lock); 1765 } 1766 1767 mutex_destroy(&zilog->zl_lock); 1768 1769 cv_destroy(&zilog->zl_cv_writer); 1770 cv_destroy(&zilog->zl_cv_suspend); 1771 cv_destroy(&zilog->zl_cv_batch[0]); 1772 cv_destroy(&zilog->zl_cv_batch[1]); 1773 1774 kmem_free(zilog, sizeof (zilog_t)); 1775} 1776 1777/* 1778 * Open an intent log. 1779 */ 1780zilog_t * 1781zil_open(objset_t *os, zil_get_data_t *get_data) 1782{ 1783 zilog_t *zilog = dmu_objset_zil(os); 1784 1785 ASSERT(zilog->zl_clean_taskq == NULL); 1786 ASSERT(zilog->zl_get_data == NULL); 1787 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 1788 1789 zilog->zl_get_data = get_data; 1790 zilog->zl_clean_taskq = taskq_create("zil_clean", 1, minclsyspri, 1791 2, 2, TASKQ_PREPOPULATE); 1792 1793 return (zilog); 1794} 1795 1796/* 1797 * Close an intent log. 1798 */ 1799void 1800zil_close(zilog_t *zilog) 1801{ 1802 lwb_t *lwb; 1803 uint64_t txg = 0; 1804 1805 zil_commit(zilog, 0); /* commit all itx */ 1806 1807 /* 1808 * The lwb_max_txg for the stubby lwb will reflect the last activity 1809 * for the zil. After a txg_wait_synced() on the txg we know all the 1810 * callbacks have occurred that may clean the zil. Only then can we 1811 * destroy the zl_clean_taskq. 1812 */ 1813 mutex_enter(&zilog->zl_lock); 1814 lwb = list_tail(&zilog->zl_lwb_list); 1815 if (lwb != NULL) 1816 txg = lwb->lwb_max_txg; 1817 mutex_exit(&zilog->zl_lock); 1818 if (txg) 1819 txg_wait_synced(zilog->zl_dmu_pool, txg); 1820 ASSERT(!zilog_is_dirty(zilog)); 1821 1822 taskq_destroy(zilog->zl_clean_taskq); 1823 zilog->zl_clean_taskq = NULL; 1824 zilog->zl_get_data = NULL; 1825 1826 /* 1827 * We should have only one LWB left on the list; remove it now. 1828 */ 1829 mutex_enter(&zilog->zl_lock); 1830 lwb = list_head(&zilog->zl_lwb_list); 1831 if (lwb != NULL) { 1832 ASSERT(lwb == list_tail(&zilog->zl_lwb_list)); 1833 list_remove(&zilog->zl_lwb_list, lwb); 1834 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 1835 kmem_cache_free(zil_lwb_cache, lwb); 1836 } 1837 mutex_exit(&zilog->zl_lock); 1838} 1839 1840static char *suspend_tag = "zil suspending"; 1841 1842/* 1843 * Suspend an intent log. While in suspended mode, we still honor 1844 * synchronous semantics, but we rely on txg_wait_synced() to do it. 1845 * On old version pools, we suspend the log briefly when taking a 1846 * snapshot so that it will have an empty intent log. 1847 * 1848 * Long holds are not really intended to be used the way we do here -- 1849 * held for such a short time. A concurrent caller of dsl_dataset_long_held() 1850 * could fail. Therefore we take pains to only put a long hold if it is 1851 * actually necessary. Fortunately, it will only be necessary if the 1852 * objset is currently mounted (or the ZVOL equivalent). In that case it 1853 * will already have a long hold, so we are not really making things any worse. 1854 * 1855 * Ideally, we would locate the existing long-holder (i.e. the zfsvfs_t or 1856 * zvol_state_t), and use their mechanism to prevent their hold from being 1857 * dropped (e.g. VFS_HOLD()). However, that would be even more pain for 1858 * very little gain. 1859 * 1860 * if cookiep == NULL, this does both the suspend & resume. 1861 * Otherwise, it returns with the dataset "long held", and the cookie 1862 * should be passed into zil_resume(). 1863 */ 1864int 1865zil_suspend(const char *osname, void **cookiep) 1866{ 1867 objset_t *os; 1868 zilog_t *zilog; 1869 const zil_header_t *zh; 1870 int error; 1871 1872 error = dmu_objset_hold(osname, suspend_tag, &os); 1873 if (error != 0) 1874 return (error); 1875 zilog = dmu_objset_zil(os); 1876 1877 mutex_enter(&zilog->zl_lock); 1878 zh = zilog->zl_header; 1879 1880 if (zh->zh_flags & ZIL_REPLAY_NEEDED) { /* unplayed log */ 1881 mutex_exit(&zilog->zl_lock); 1882 dmu_objset_rele(os, suspend_tag); 1883 return (SET_ERROR(EBUSY)); 1884 } 1885 1886 /* 1887 * Don't put a long hold in the cases where we can avoid it. This 1888 * is when there is no cookie so we are doing a suspend & resume 1889 * (i.e. called from zil_vdev_offline()), and there's nothing to do 1890 * for the suspend because it's already suspended, or there's no ZIL. 1891 */ 1892 if (cookiep == NULL && !zilog->zl_suspending && 1893 (zilog->zl_suspend > 0 || BP_IS_HOLE(&zh->zh_log))) { 1894 mutex_exit(&zilog->zl_lock); 1895 dmu_objset_rele(os, suspend_tag); 1896 return (0); 1897 } 1898 1899 dsl_dataset_long_hold(dmu_objset_ds(os), suspend_tag); 1900 dsl_pool_rele(dmu_objset_pool(os), suspend_tag); 1901 1902 zilog->zl_suspend++; 1903 1904 if (zilog->zl_suspend > 1) { 1905 /* 1906 * Someone else is already suspending it. 1907 * Just wait for them to finish. 1908 */ 1909 1910 while (zilog->zl_suspending) 1911 cv_wait(&zilog->zl_cv_suspend, &zilog->zl_lock); 1912 mutex_exit(&zilog->zl_lock); 1913 1914 if (cookiep == NULL) 1915 zil_resume(os); 1916 else 1917 *cookiep = os; 1918 return (0); 1919 } 1920 1921 /* 1922 * If there is no pointer to an on-disk block, this ZIL must not 1923 * be active (e.g. filesystem not mounted), so there's nothing 1924 * to clean up. 1925 */ 1926 if (BP_IS_HOLE(&zh->zh_log)) { 1927 ASSERT(cookiep != NULL); /* fast path already handled */ 1928 1929 *cookiep = os; 1930 mutex_exit(&zilog->zl_lock); 1931 return (0); 1932 } 1933 1934 zilog->zl_suspending = B_TRUE; 1935 mutex_exit(&zilog->zl_lock); 1936 1937 zil_commit(zilog, 0); 1938 1939 zil_destroy(zilog, B_FALSE); 1940 1941 mutex_enter(&zilog->zl_lock); 1942 zilog->zl_suspending = B_FALSE; 1943 cv_broadcast(&zilog->zl_cv_suspend); 1944 mutex_exit(&zilog->zl_lock); 1945 1946 if (cookiep == NULL) 1947 zil_resume(os); 1948 else 1949 *cookiep = os; 1950 return (0); 1951} 1952 1953void 1954zil_resume(void *cookie) 1955{ 1956 objset_t *os = cookie; 1957 zilog_t *zilog = dmu_objset_zil(os); 1958 1959 mutex_enter(&zilog->zl_lock); 1960 ASSERT(zilog->zl_suspend != 0); 1961 zilog->zl_suspend--; 1962 mutex_exit(&zilog->zl_lock); 1963 dsl_dataset_long_rele(dmu_objset_ds(os), suspend_tag); 1964 dsl_dataset_rele(dmu_objset_ds(os), suspend_tag); 1965} 1966 1967typedef struct zil_replay_arg { 1968 zil_replay_func_t **zr_replay; 1969 void *zr_arg; 1970 boolean_t zr_byteswap; 1971 char *zr_lr; 1972} zil_replay_arg_t; 1973 1974static int 1975zil_replay_error(zilog_t *zilog, lr_t *lr, int error) 1976{ 1977 char name[ZFS_MAX_DATASET_NAME_LEN]; 1978 1979 zilog->zl_replaying_seq--; /* didn't actually replay this one */ 1980 1981 dmu_objset_name(zilog->zl_os, name); 1982 1983 cmn_err(CE_WARN, "ZFS replay transaction error %d, " 1984 "dataset %s, seq 0x%llx, txtype %llu %s\n", error, name, 1985 (u_longlong_t)lr->lrc_seq, 1986 (u_longlong_t)(lr->lrc_txtype & ~TX_CI), 1987 (lr->lrc_txtype & TX_CI) ? "CI" : ""); 1988 1989 return (error); 1990} 1991 1992static int 1993zil_replay_log_record(zilog_t *zilog, lr_t *lr, void *zra, uint64_t claim_txg) 1994{ 1995 zil_replay_arg_t *zr = zra; 1996 const zil_header_t *zh = zilog->zl_header; 1997 uint64_t reclen = lr->lrc_reclen; 1998 uint64_t txtype = lr->lrc_txtype; 1999 int error = 0; 2000 2001 zilog->zl_replaying_seq = lr->lrc_seq; 2002 2003 if (lr->lrc_seq <= zh->zh_replay_seq) /* already replayed */ 2004 return (0); 2005 2006 if (lr->lrc_txg < claim_txg) /* already committed */ 2007 return (0); 2008 2009 /* Strip case-insensitive bit, still present in log record */ 2010 txtype &= ~TX_CI; 2011 2012 if (txtype == 0 || txtype >= TX_MAX_TYPE) 2013 return (zil_replay_error(zilog, lr, EINVAL)); 2014 2015 /* 2016 * If this record type can be logged out of order, the object 2017 * (lr_foid) may no longer exist. That's legitimate, not an error. 2018 */ 2019 if (TX_OOO(txtype)) { 2020 error = dmu_object_info(zilog->zl_os, 2021 ((lr_ooo_t *)lr)->lr_foid, NULL); 2022 if (error == ENOENT || error == EEXIST) 2023 return (0); 2024 } 2025 2026 /* 2027 * Make a copy of the data so we can revise and extend it. 2028 */ 2029 bcopy(lr, zr->zr_lr, reclen); 2030 2031 /* 2032 * If this is a TX_WRITE with a blkptr, suck in the data. 2033 */ 2034 if (txtype == TX_WRITE && reclen == sizeof (lr_write_t)) { 2035 error = zil_read_log_data(zilog, (lr_write_t *)lr, 2036 zr->zr_lr + reclen); 2037 if (error != 0) 2038 return (zil_replay_error(zilog, lr, error)); 2039 } 2040 2041 /* 2042 * The log block containing this lr may have been byteswapped 2043 * so that we can easily examine common fields like lrc_txtype. 2044 * However, the log is a mix of different record types, and only the 2045 * replay vectors know how to byteswap their records. Therefore, if 2046 * the lr was byteswapped, undo it before invoking the replay vector. 2047 */ 2048 if (zr->zr_byteswap) 2049 byteswap_uint64_array(zr->zr_lr, reclen); 2050 2051 /* 2052 * We must now do two things atomically: replay this log record, 2053 * and update the log header sequence number to reflect the fact that 2054 * we did so. At the end of each replay function the sequence number 2055 * is updated if we are in replay mode. 2056 */ 2057 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, zr->zr_byteswap); 2058 if (error != 0) { 2059 /* 2060 * The DMU's dnode layer doesn't see removes until the txg 2061 * commits, so a subsequent claim can spuriously fail with 2062 * EEXIST. So if we receive any error we try syncing out 2063 * any removes then retry the transaction. Note that we 2064 * specify B_FALSE for byteswap now, so we don't do it twice. 2065 */ 2066 txg_wait_synced(spa_get_dsl(zilog->zl_spa), 0); 2067 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, B_FALSE); 2068 if (error != 0) 2069 return (zil_replay_error(zilog, lr, error)); 2070 } 2071 return (0); 2072} 2073 2074/* ARGSUSED */ 2075static int 2076zil_incr_blks(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg) 2077{ 2078 zilog->zl_replay_blks++; 2079 2080 return (0); 2081} 2082 2083/* 2084 * If this dataset has a non-empty intent log, replay it and destroy it. 2085 */ 2086void 2087zil_replay(objset_t *os, void *arg, zil_replay_func_t *replay_func[TX_MAX_TYPE]) 2088{ 2089 zilog_t *zilog = dmu_objset_zil(os); 2090 const zil_header_t *zh = zilog->zl_header; 2091 zil_replay_arg_t zr; 2092 2093 if ((zh->zh_flags & ZIL_REPLAY_NEEDED) == 0) { 2094 zil_destroy(zilog, B_TRUE); 2095 return; 2096 } 2097 2098 zr.zr_replay = replay_func; 2099 zr.zr_arg = arg; 2100 zr.zr_byteswap = BP_SHOULD_BYTESWAP(&zh->zh_log); 2101 zr.zr_lr = kmem_alloc(2 * SPA_MAXBLOCKSIZE, KM_SLEEP); 2102 2103 /* 2104 * Wait for in-progress removes to sync before starting replay. 2105 */ 2106 txg_wait_synced(zilog->zl_dmu_pool, 0); 2107 2108 zilog->zl_replay = B_TRUE; 2109 zilog->zl_replay_time = ddi_get_lbolt(); 2110 ASSERT(zilog->zl_replay_blks == 0); 2111 (void) zil_parse(zilog, zil_incr_blks, zil_replay_log_record, &zr, 2112 zh->zh_claim_txg); 2113 kmem_free(zr.zr_lr, 2 * SPA_MAXBLOCKSIZE); 2114 2115 zil_destroy(zilog, B_FALSE); 2116 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 2117 zilog->zl_replay = B_FALSE; 2118} 2119 2120boolean_t 2121zil_replaying(zilog_t *zilog, dmu_tx_t *tx) 2122{ 2123 if (zilog->zl_sync == ZFS_SYNC_DISABLED) 2124 return (B_TRUE); 2125 2126 if (zilog->zl_replay) { 2127 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 2128 zilog->zl_replayed_seq[dmu_tx_get_txg(tx) & TXG_MASK] = 2129 zilog->zl_replaying_seq; 2130 return (B_TRUE); 2131 } 2132 2133 return (B_FALSE); 2134} 2135 2136/* ARGSUSED */ 2137int 2138zil_vdev_offline(const char *osname, void *arg) 2139{ 2140 int error; 2141 2142 error = zil_suspend(osname, NULL); 2143 if (error != 0) 2144 return (SET_ERROR(EEXIST)); 2145 return (0); 2146} 2147