zil.c revision 288569
1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21/* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2011, 2014 by Delphix. All rights reserved. 24 */ 25 26/* Portions Copyright 2010 Robert Milkowski */ 27 28#include <sys/zfs_context.h> 29#include <sys/spa.h> 30#include <sys/dmu.h> 31#include <sys/zap.h> 32#include <sys/arc.h> 33#include <sys/stat.h> 34#include <sys/resource.h> 35#include <sys/zil.h> 36#include <sys/zil_impl.h> 37#include <sys/dsl_dataset.h> 38#include <sys/vdev_impl.h> 39#include <sys/dmu_tx.h> 40#include <sys/dsl_pool.h> 41 42/* 43 * The zfs intent log (ZIL) saves transaction records of system calls 44 * that change the file system in memory with enough information 45 * to be able to replay them. These are stored in memory until 46 * either the DMU transaction group (txg) commits them to the stable pool 47 * and they can be discarded, or they are flushed to the stable log 48 * (also in the pool) due to a fsync, O_DSYNC or other synchronous 49 * requirement. In the event of a panic or power fail then those log 50 * records (transactions) are replayed. 51 * 52 * There is one ZIL per file system. Its on-disk (pool) format consists 53 * of 3 parts: 54 * 55 * - ZIL header 56 * - ZIL blocks 57 * - ZIL records 58 * 59 * A log record holds a system call transaction. Log blocks can 60 * hold many log records and the blocks are chained together. 61 * Each ZIL block contains a block pointer (blkptr_t) to the next 62 * ZIL block in the chain. The ZIL header points to the first 63 * block in the chain. Note there is not a fixed place in the pool 64 * to hold blocks. They are dynamically allocated and freed as 65 * needed from the blocks available. Figure X shows the ZIL structure: 66 */ 67 68/* 69 * Disable intent logging replay. This global ZIL switch affects all pools. 70 */ 71int zil_replay_disable = 0; 72SYSCTL_DECL(_vfs_zfs); 73TUNABLE_INT("vfs.zfs.zil_replay_disable", &zil_replay_disable); 74SYSCTL_INT(_vfs_zfs, OID_AUTO, zil_replay_disable, CTLFLAG_RW, 75 &zil_replay_disable, 0, "Disable intent logging replay"); 76 77/* 78 * Tunable parameter for debugging or performance analysis. Setting 79 * zfs_nocacheflush will cause corruption on power loss if a volatile 80 * out-of-order write cache is enabled. 81 */ 82boolean_t zfs_nocacheflush = B_FALSE; 83TUNABLE_INT("vfs.zfs.cache_flush_disable", &zfs_nocacheflush); 84SYSCTL_INT(_vfs_zfs, OID_AUTO, cache_flush_disable, CTLFLAG_RDTUN, 85 &zfs_nocacheflush, 0, "Disable cache flush"); 86boolean_t zfs_trim_enabled = B_TRUE; 87SYSCTL_DECL(_vfs_zfs_trim); 88TUNABLE_INT("vfs.zfs.trim.enabled", &zfs_trim_enabled); 89SYSCTL_INT(_vfs_zfs_trim, OID_AUTO, enabled, CTLFLAG_RDTUN, &zfs_trim_enabled, 0, 90 "Enable ZFS TRIM"); 91 92static kmem_cache_t *zil_lwb_cache; 93 94static void zil_async_to_sync(zilog_t *zilog, uint64_t foid); 95 96#define LWB_EMPTY(lwb) ((BP_GET_LSIZE(&lwb->lwb_blk) - \ 97 sizeof (zil_chain_t)) == (lwb->lwb_sz - lwb->lwb_nused)) 98 99 100/* 101 * ziltest is by and large an ugly hack, but very useful in 102 * checking replay without tedious work. 103 * When running ziltest we want to keep all itx's and so maintain 104 * a single list in the zl_itxg[] that uses a high txg: ZILTEST_TXG 105 * We subtract TXG_CONCURRENT_STATES to allow for common code. 106 */ 107#define ZILTEST_TXG (UINT64_MAX - TXG_CONCURRENT_STATES) 108 109static int 110zil_bp_compare(const void *x1, const void *x2) 111{ 112 const dva_t *dva1 = &((zil_bp_node_t *)x1)->zn_dva; 113 const dva_t *dva2 = &((zil_bp_node_t *)x2)->zn_dva; 114 115 if (DVA_GET_VDEV(dva1) < DVA_GET_VDEV(dva2)) 116 return (-1); 117 if (DVA_GET_VDEV(dva1) > DVA_GET_VDEV(dva2)) 118 return (1); 119 120 if (DVA_GET_OFFSET(dva1) < DVA_GET_OFFSET(dva2)) 121 return (-1); 122 if (DVA_GET_OFFSET(dva1) > DVA_GET_OFFSET(dva2)) 123 return (1); 124 125 return (0); 126} 127 128static void 129zil_bp_tree_init(zilog_t *zilog) 130{ 131 avl_create(&zilog->zl_bp_tree, zil_bp_compare, 132 sizeof (zil_bp_node_t), offsetof(zil_bp_node_t, zn_node)); 133} 134 135static void 136zil_bp_tree_fini(zilog_t *zilog) 137{ 138 avl_tree_t *t = &zilog->zl_bp_tree; 139 zil_bp_node_t *zn; 140 void *cookie = NULL; 141 142 while ((zn = avl_destroy_nodes(t, &cookie)) != NULL) 143 kmem_free(zn, sizeof (zil_bp_node_t)); 144 145 avl_destroy(t); 146} 147 148int 149zil_bp_tree_add(zilog_t *zilog, const blkptr_t *bp) 150{ 151 avl_tree_t *t = &zilog->zl_bp_tree; 152 const dva_t *dva; 153 zil_bp_node_t *zn; 154 avl_index_t where; 155 156 if (BP_IS_EMBEDDED(bp)) 157 return (0); 158 159 dva = BP_IDENTITY(bp); 160 161 if (avl_find(t, dva, &where) != NULL) 162 return (SET_ERROR(EEXIST)); 163 164 zn = kmem_alloc(sizeof (zil_bp_node_t), KM_SLEEP); 165 zn->zn_dva = *dva; 166 avl_insert(t, zn, where); 167 168 return (0); 169} 170 171static zil_header_t * 172zil_header_in_syncing_context(zilog_t *zilog) 173{ 174 return ((zil_header_t *)zilog->zl_header); 175} 176 177static void 178zil_init_log_chain(zilog_t *zilog, blkptr_t *bp) 179{ 180 zio_cksum_t *zc = &bp->blk_cksum; 181 182 zc->zc_word[ZIL_ZC_GUID_0] = spa_get_random(-1ULL); 183 zc->zc_word[ZIL_ZC_GUID_1] = spa_get_random(-1ULL); 184 zc->zc_word[ZIL_ZC_OBJSET] = dmu_objset_id(zilog->zl_os); 185 zc->zc_word[ZIL_ZC_SEQ] = 1ULL; 186} 187 188/* 189 * Read a log block and make sure it's valid. 190 */ 191static int 192zil_read_log_block(zilog_t *zilog, const blkptr_t *bp, blkptr_t *nbp, void *dst, 193 char **end) 194{ 195 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL; 196 arc_flags_t aflags = ARC_FLAG_WAIT; 197 arc_buf_t *abuf = NULL; 198 zbookmark_phys_t zb; 199 int error; 200 201 if (zilog->zl_header->zh_claim_txg == 0) 202 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; 203 204 if (!(zilog->zl_header->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) 205 zio_flags |= ZIO_FLAG_SPECULATIVE; 206 207 SET_BOOKMARK(&zb, bp->blk_cksum.zc_word[ZIL_ZC_OBJSET], 208 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]); 209 210 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf, 211 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); 212 213 if (error == 0) { 214 zio_cksum_t cksum = bp->blk_cksum; 215 216 /* 217 * Validate the checksummed log block. 218 * 219 * Sequence numbers should be... sequential. The checksum 220 * verifier for the next block should be bp's checksum plus 1. 221 * 222 * Also check the log chain linkage and size used. 223 */ 224 cksum.zc_word[ZIL_ZC_SEQ]++; 225 226 if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) { 227 zil_chain_t *zilc = abuf->b_data; 228 char *lr = (char *)(zilc + 1); 229 uint64_t len = zilc->zc_nused - sizeof (zil_chain_t); 230 231 if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum, 232 sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk)) { 233 error = SET_ERROR(ECKSUM); 234 } else { 235 ASSERT3U(len, <=, SPA_OLD_MAXBLOCKSIZE); 236 bcopy(lr, dst, len); 237 *end = (char *)dst + len; 238 *nbp = zilc->zc_next_blk; 239 } 240 } else { 241 char *lr = abuf->b_data; 242 uint64_t size = BP_GET_LSIZE(bp); 243 zil_chain_t *zilc = (zil_chain_t *)(lr + size) - 1; 244 245 if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum, 246 sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk) || 247 (zilc->zc_nused > (size - sizeof (*zilc)))) { 248 error = SET_ERROR(ECKSUM); 249 } else { 250 ASSERT3U(zilc->zc_nused, <=, 251 SPA_OLD_MAXBLOCKSIZE); 252 bcopy(lr, dst, zilc->zc_nused); 253 *end = (char *)dst + zilc->zc_nused; 254 *nbp = zilc->zc_next_blk; 255 } 256 } 257 258 VERIFY(arc_buf_remove_ref(abuf, &abuf)); 259 } 260 261 return (error); 262} 263 264/* 265 * Read a TX_WRITE log data block. 266 */ 267static int 268zil_read_log_data(zilog_t *zilog, const lr_write_t *lr, void *wbuf) 269{ 270 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL; 271 const blkptr_t *bp = &lr->lr_blkptr; 272 arc_flags_t aflags = ARC_FLAG_WAIT; 273 arc_buf_t *abuf = NULL; 274 zbookmark_phys_t zb; 275 int error; 276 277 if (BP_IS_HOLE(bp)) { 278 if (wbuf != NULL) 279 bzero(wbuf, MAX(BP_GET_LSIZE(bp), lr->lr_length)); 280 return (0); 281 } 282 283 if (zilog->zl_header->zh_claim_txg == 0) 284 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; 285 286 SET_BOOKMARK(&zb, dmu_objset_id(zilog->zl_os), lr->lr_foid, 287 ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp)); 288 289 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf, 290 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); 291 292 if (error == 0) { 293 if (wbuf != NULL) 294 bcopy(abuf->b_data, wbuf, arc_buf_size(abuf)); 295 (void) arc_buf_remove_ref(abuf, &abuf); 296 } 297 298 return (error); 299} 300 301/* 302 * Parse the intent log, and call parse_func for each valid record within. 303 */ 304int 305zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func, 306 zil_parse_lr_func_t *parse_lr_func, void *arg, uint64_t txg) 307{ 308 const zil_header_t *zh = zilog->zl_header; 309 boolean_t claimed = !!zh->zh_claim_txg; 310 uint64_t claim_blk_seq = claimed ? zh->zh_claim_blk_seq : UINT64_MAX; 311 uint64_t claim_lr_seq = claimed ? zh->zh_claim_lr_seq : UINT64_MAX; 312 uint64_t max_blk_seq = 0; 313 uint64_t max_lr_seq = 0; 314 uint64_t blk_count = 0; 315 uint64_t lr_count = 0; 316 blkptr_t blk, next_blk; 317 char *lrbuf, *lrp; 318 int error = 0; 319 320 /* 321 * Old logs didn't record the maximum zh_claim_lr_seq. 322 */ 323 if (!(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) 324 claim_lr_seq = UINT64_MAX; 325 326 /* 327 * Starting at the block pointed to by zh_log we read the log chain. 328 * For each block in the chain we strongly check that block to 329 * ensure its validity. We stop when an invalid block is found. 330 * For each block pointer in the chain we call parse_blk_func(). 331 * For each record in each valid block we call parse_lr_func(). 332 * If the log has been claimed, stop if we encounter a sequence 333 * number greater than the highest claimed sequence number. 334 */ 335 lrbuf = zio_buf_alloc(SPA_OLD_MAXBLOCKSIZE); 336 zil_bp_tree_init(zilog); 337 338 for (blk = zh->zh_log; !BP_IS_HOLE(&blk); blk = next_blk) { 339 uint64_t blk_seq = blk.blk_cksum.zc_word[ZIL_ZC_SEQ]; 340 int reclen; 341 char *end; 342 343 if (blk_seq > claim_blk_seq) 344 break; 345 if ((error = parse_blk_func(zilog, &blk, arg, txg)) != 0) 346 break; 347 ASSERT3U(max_blk_seq, <, blk_seq); 348 max_blk_seq = blk_seq; 349 blk_count++; 350 351 if (max_lr_seq == claim_lr_seq && max_blk_seq == claim_blk_seq) 352 break; 353 354 error = zil_read_log_block(zilog, &blk, &next_blk, lrbuf, &end); 355 if (error != 0) 356 break; 357 358 for (lrp = lrbuf; lrp < end; lrp += reclen) { 359 lr_t *lr = (lr_t *)lrp; 360 reclen = lr->lrc_reclen; 361 ASSERT3U(reclen, >=, sizeof (lr_t)); 362 if (lr->lrc_seq > claim_lr_seq) 363 goto done; 364 if ((error = parse_lr_func(zilog, lr, arg, txg)) != 0) 365 goto done; 366 ASSERT3U(max_lr_seq, <, lr->lrc_seq); 367 max_lr_seq = lr->lrc_seq; 368 lr_count++; 369 } 370 } 371done: 372 zilog->zl_parse_error = error; 373 zilog->zl_parse_blk_seq = max_blk_seq; 374 zilog->zl_parse_lr_seq = max_lr_seq; 375 zilog->zl_parse_blk_count = blk_count; 376 zilog->zl_parse_lr_count = lr_count; 377 378 ASSERT(!claimed || !(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID) || 379 (max_blk_seq == claim_blk_seq && max_lr_seq == claim_lr_seq)); 380 381 zil_bp_tree_fini(zilog); 382 zio_buf_free(lrbuf, SPA_OLD_MAXBLOCKSIZE); 383 384 return (error); 385} 386 387static int 388zil_claim_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t first_txg) 389{ 390 /* 391 * Claim log block if not already committed and not already claimed. 392 * If tx == NULL, just verify that the block is claimable. 393 */ 394 if (BP_IS_HOLE(bp) || bp->blk_birth < first_txg || 395 zil_bp_tree_add(zilog, bp) != 0) 396 return (0); 397 398 return (zio_wait(zio_claim(NULL, zilog->zl_spa, 399 tx == NULL ? 0 : first_txg, bp, spa_claim_notify, NULL, 400 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB))); 401} 402 403static int 404zil_claim_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t first_txg) 405{ 406 lr_write_t *lr = (lr_write_t *)lrc; 407 int error; 408 409 if (lrc->lrc_txtype != TX_WRITE) 410 return (0); 411 412 /* 413 * If the block is not readable, don't claim it. This can happen 414 * in normal operation when a log block is written to disk before 415 * some of the dmu_sync() blocks it points to. In this case, the 416 * transaction cannot have been committed to anyone (we would have 417 * waited for all writes to be stable first), so it is semantically 418 * correct to declare this the end of the log. 419 */ 420 if (lr->lr_blkptr.blk_birth >= first_txg && 421 (error = zil_read_log_data(zilog, lr, NULL)) != 0) 422 return (error); 423 return (zil_claim_log_block(zilog, &lr->lr_blkptr, tx, first_txg)); 424} 425 426/* ARGSUSED */ 427static int 428zil_free_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t claim_txg) 429{ 430 zio_free_zil(zilog->zl_spa, dmu_tx_get_txg(tx), bp); 431 432 return (0); 433} 434 435static int 436zil_free_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t claim_txg) 437{ 438 lr_write_t *lr = (lr_write_t *)lrc; 439 blkptr_t *bp = &lr->lr_blkptr; 440 441 /* 442 * If we previously claimed it, we need to free it. 443 */ 444 if (claim_txg != 0 && lrc->lrc_txtype == TX_WRITE && 445 bp->blk_birth >= claim_txg && zil_bp_tree_add(zilog, bp) == 0 && 446 !BP_IS_HOLE(bp)) 447 zio_free(zilog->zl_spa, dmu_tx_get_txg(tx), bp); 448 449 return (0); 450} 451 452static lwb_t * 453zil_alloc_lwb(zilog_t *zilog, blkptr_t *bp, uint64_t txg) 454{ 455 lwb_t *lwb; 456 457 lwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP); 458 lwb->lwb_zilog = zilog; 459 lwb->lwb_blk = *bp; 460 lwb->lwb_buf = zio_buf_alloc(BP_GET_LSIZE(bp)); 461 lwb->lwb_max_txg = txg; 462 lwb->lwb_zio = NULL; 463 lwb->lwb_tx = NULL; 464 if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) { 465 lwb->lwb_nused = sizeof (zil_chain_t); 466 lwb->lwb_sz = BP_GET_LSIZE(bp); 467 } else { 468 lwb->lwb_nused = 0; 469 lwb->lwb_sz = BP_GET_LSIZE(bp) - sizeof (zil_chain_t); 470 } 471 472 mutex_enter(&zilog->zl_lock); 473 list_insert_tail(&zilog->zl_lwb_list, lwb); 474 mutex_exit(&zilog->zl_lock); 475 476 return (lwb); 477} 478 479/* 480 * Called when we create in-memory log transactions so that we know 481 * to cleanup the itxs at the end of spa_sync(). 482 */ 483void 484zilog_dirty(zilog_t *zilog, uint64_t txg) 485{ 486 dsl_pool_t *dp = zilog->zl_dmu_pool; 487 dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os); 488 489 if (ds->ds_is_snapshot) 490 panic("dirtying snapshot!"); 491 492 if (txg_list_add(&dp->dp_dirty_zilogs, zilog, txg)) { 493 /* up the hold count until we can be written out */ 494 dmu_buf_add_ref(ds->ds_dbuf, zilog); 495 } 496} 497 498boolean_t 499zilog_is_dirty(zilog_t *zilog) 500{ 501 dsl_pool_t *dp = zilog->zl_dmu_pool; 502 503 for (int t = 0; t < TXG_SIZE; t++) { 504 if (txg_list_member(&dp->dp_dirty_zilogs, zilog, t)) 505 return (B_TRUE); 506 } 507 return (B_FALSE); 508} 509 510/* 511 * Create an on-disk intent log. 512 */ 513static lwb_t * 514zil_create(zilog_t *zilog) 515{ 516 const zil_header_t *zh = zilog->zl_header; 517 lwb_t *lwb = NULL; 518 uint64_t txg = 0; 519 dmu_tx_t *tx = NULL; 520 blkptr_t blk; 521 int error = 0; 522 523 /* 524 * Wait for any previous destroy to complete. 525 */ 526 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 527 528 ASSERT(zh->zh_claim_txg == 0); 529 ASSERT(zh->zh_replay_seq == 0); 530 531 blk = zh->zh_log; 532 533 /* 534 * Allocate an initial log block if: 535 * - there isn't one already 536 * - the existing block is the wrong endianess 537 */ 538 if (BP_IS_HOLE(&blk) || BP_SHOULD_BYTESWAP(&blk)) { 539 tx = dmu_tx_create(zilog->zl_os); 540 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 541 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 542 txg = dmu_tx_get_txg(tx); 543 544 if (!BP_IS_HOLE(&blk)) { 545 zio_free_zil(zilog->zl_spa, txg, &blk); 546 BP_ZERO(&blk); 547 } 548 549 error = zio_alloc_zil(zilog->zl_spa, txg, &blk, NULL, 550 ZIL_MIN_BLKSZ, zilog->zl_logbias == ZFS_LOGBIAS_LATENCY); 551 552 if (error == 0) 553 zil_init_log_chain(zilog, &blk); 554 } 555 556 /* 557 * Allocate a log write buffer (lwb) for the first log block. 558 */ 559 if (error == 0) 560 lwb = zil_alloc_lwb(zilog, &blk, txg); 561 562 /* 563 * If we just allocated the first log block, commit our transaction 564 * and wait for zil_sync() to stuff the block poiner into zh_log. 565 * (zh is part of the MOS, so we cannot modify it in open context.) 566 */ 567 if (tx != NULL) { 568 dmu_tx_commit(tx); 569 txg_wait_synced(zilog->zl_dmu_pool, txg); 570 } 571 572 ASSERT(bcmp(&blk, &zh->zh_log, sizeof (blk)) == 0); 573 574 return (lwb); 575} 576 577/* 578 * In one tx, free all log blocks and clear the log header. 579 * If keep_first is set, then we're replaying a log with no content. 580 * We want to keep the first block, however, so that the first 581 * synchronous transaction doesn't require a txg_wait_synced() 582 * in zil_create(). We don't need to txg_wait_synced() here either 583 * when keep_first is set, because both zil_create() and zil_destroy() 584 * will wait for any in-progress destroys to complete. 585 */ 586void 587zil_destroy(zilog_t *zilog, boolean_t keep_first) 588{ 589 const zil_header_t *zh = zilog->zl_header; 590 lwb_t *lwb; 591 dmu_tx_t *tx; 592 uint64_t txg; 593 594 /* 595 * Wait for any previous destroy to complete. 596 */ 597 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 598 599 zilog->zl_old_header = *zh; /* debugging aid */ 600 601 if (BP_IS_HOLE(&zh->zh_log)) 602 return; 603 604 tx = dmu_tx_create(zilog->zl_os); 605 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 606 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 607 txg = dmu_tx_get_txg(tx); 608 609 mutex_enter(&zilog->zl_lock); 610 611 ASSERT3U(zilog->zl_destroy_txg, <, txg); 612 zilog->zl_destroy_txg = txg; 613 zilog->zl_keep_first = keep_first; 614 615 if (!list_is_empty(&zilog->zl_lwb_list)) { 616 ASSERT(zh->zh_claim_txg == 0); 617 VERIFY(!keep_first); 618 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { 619 list_remove(&zilog->zl_lwb_list, lwb); 620 if (lwb->lwb_buf != NULL) 621 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 622 zio_free_zil(zilog->zl_spa, txg, &lwb->lwb_blk); 623 kmem_cache_free(zil_lwb_cache, lwb); 624 } 625 } else if (!keep_first) { 626 zil_destroy_sync(zilog, tx); 627 } 628 mutex_exit(&zilog->zl_lock); 629 630 dmu_tx_commit(tx); 631} 632 633void 634zil_destroy_sync(zilog_t *zilog, dmu_tx_t *tx) 635{ 636 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 637 (void) zil_parse(zilog, zil_free_log_block, 638 zil_free_log_record, tx, zilog->zl_header->zh_claim_txg); 639} 640 641int 642zil_claim(dsl_pool_t *dp, dsl_dataset_t *ds, void *txarg) 643{ 644 dmu_tx_t *tx = txarg; 645 uint64_t first_txg = dmu_tx_get_txg(tx); 646 zilog_t *zilog; 647 zil_header_t *zh; 648 objset_t *os; 649 int error; 650 651 error = dmu_objset_own_obj(dp, ds->ds_object, 652 DMU_OST_ANY, B_FALSE, FTAG, &os); 653 if (error != 0) { 654 /* 655 * EBUSY indicates that the objset is inconsistent, in which 656 * case it can not have a ZIL. 657 */ 658 if (error != EBUSY) { 659 cmn_err(CE_WARN, "can't open objset for %llu, error %u", 660 (unsigned long long)ds->ds_object, error); 661 } 662 return (0); 663 } 664 665 zilog = dmu_objset_zil(os); 666 zh = zil_header_in_syncing_context(zilog); 667 668 if (spa_get_log_state(zilog->zl_spa) == SPA_LOG_CLEAR) { 669 if (!BP_IS_HOLE(&zh->zh_log)) 670 zio_free_zil(zilog->zl_spa, first_txg, &zh->zh_log); 671 BP_ZERO(&zh->zh_log); 672 dsl_dataset_dirty(dmu_objset_ds(os), tx); 673 dmu_objset_disown(os, FTAG); 674 return (0); 675 } 676 677 /* 678 * Claim all log blocks if we haven't already done so, and remember 679 * the highest claimed sequence number. This ensures that if we can 680 * read only part of the log now (e.g. due to a missing device), 681 * but we can read the entire log later, we will not try to replay 682 * or destroy beyond the last block we successfully claimed. 683 */ 684 ASSERT3U(zh->zh_claim_txg, <=, first_txg); 685 if (zh->zh_claim_txg == 0 && !BP_IS_HOLE(&zh->zh_log)) { 686 (void) zil_parse(zilog, zil_claim_log_block, 687 zil_claim_log_record, tx, first_txg); 688 zh->zh_claim_txg = first_txg; 689 zh->zh_claim_blk_seq = zilog->zl_parse_blk_seq; 690 zh->zh_claim_lr_seq = zilog->zl_parse_lr_seq; 691 if (zilog->zl_parse_lr_count || zilog->zl_parse_blk_count > 1) 692 zh->zh_flags |= ZIL_REPLAY_NEEDED; 693 zh->zh_flags |= ZIL_CLAIM_LR_SEQ_VALID; 694 dsl_dataset_dirty(dmu_objset_ds(os), tx); 695 } 696 697 ASSERT3U(first_txg, ==, (spa_last_synced_txg(zilog->zl_spa) + 1)); 698 dmu_objset_disown(os, FTAG); 699 return (0); 700} 701 702/* 703 * Check the log by walking the log chain. 704 * Checksum errors are ok as they indicate the end of the chain. 705 * Any other error (no device or read failure) returns an error. 706 */ 707/* ARGSUSED */ 708int 709zil_check_log_chain(dsl_pool_t *dp, dsl_dataset_t *ds, void *tx) 710{ 711 zilog_t *zilog; 712 objset_t *os; 713 blkptr_t *bp; 714 int error; 715 716 ASSERT(tx == NULL); 717 718 error = dmu_objset_from_ds(ds, &os); 719 if (error != 0) { 720 cmn_err(CE_WARN, "can't open objset %llu, error %d", 721 (unsigned long long)ds->ds_object, error); 722 return (0); 723 } 724 725 zilog = dmu_objset_zil(os); 726 bp = (blkptr_t *)&zilog->zl_header->zh_log; 727 728 /* 729 * Check the first block and determine if it's on a log device 730 * which may have been removed or faulted prior to loading this 731 * pool. If so, there's no point in checking the rest of the log 732 * as its content should have already been synced to the pool. 733 */ 734 if (!BP_IS_HOLE(bp)) { 735 vdev_t *vd; 736 boolean_t valid = B_TRUE; 737 738 spa_config_enter(os->os_spa, SCL_STATE, FTAG, RW_READER); 739 vd = vdev_lookup_top(os->os_spa, DVA_GET_VDEV(&bp->blk_dva[0])); 740 if (vd->vdev_islog && vdev_is_dead(vd)) 741 valid = vdev_log_state_valid(vd); 742 spa_config_exit(os->os_spa, SCL_STATE, FTAG); 743 744 if (!valid) 745 return (0); 746 } 747 748 /* 749 * Because tx == NULL, zil_claim_log_block() will not actually claim 750 * any blocks, but just determine whether it is possible to do so. 751 * In addition to checking the log chain, zil_claim_log_block() 752 * will invoke zio_claim() with a done func of spa_claim_notify(), 753 * which will update spa_max_claim_txg. See spa_load() for details. 754 */ 755 error = zil_parse(zilog, zil_claim_log_block, zil_claim_log_record, tx, 756 zilog->zl_header->zh_claim_txg ? -1ULL : spa_first_txg(os->os_spa)); 757 758 return ((error == ECKSUM || error == ENOENT) ? 0 : error); 759} 760 761static int 762zil_vdev_compare(const void *x1, const void *x2) 763{ 764 const uint64_t v1 = ((zil_vdev_node_t *)x1)->zv_vdev; 765 const uint64_t v2 = ((zil_vdev_node_t *)x2)->zv_vdev; 766 767 if (v1 < v2) 768 return (-1); 769 if (v1 > v2) 770 return (1); 771 772 return (0); 773} 774 775void 776zil_add_block(zilog_t *zilog, const blkptr_t *bp) 777{ 778 avl_tree_t *t = &zilog->zl_vdev_tree; 779 avl_index_t where; 780 zil_vdev_node_t *zv, zvsearch; 781 int ndvas = BP_GET_NDVAS(bp); 782 int i; 783 784 if (zfs_nocacheflush) 785 return; 786 787 ASSERT(zilog->zl_writer); 788 789 /* 790 * Even though we're zl_writer, we still need a lock because the 791 * zl_get_data() callbacks may have dmu_sync() done callbacks 792 * that will run concurrently. 793 */ 794 mutex_enter(&zilog->zl_vdev_lock); 795 for (i = 0; i < ndvas; i++) { 796 zvsearch.zv_vdev = DVA_GET_VDEV(&bp->blk_dva[i]); 797 if (avl_find(t, &zvsearch, &where) == NULL) { 798 zv = kmem_alloc(sizeof (*zv), KM_SLEEP); 799 zv->zv_vdev = zvsearch.zv_vdev; 800 avl_insert(t, zv, where); 801 } 802 } 803 mutex_exit(&zilog->zl_vdev_lock); 804} 805 806static void 807zil_flush_vdevs(zilog_t *zilog) 808{ 809 spa_t *spa = zilog->zl_spa; 810 avl_tree_t *t = &zilog->zl_vdev_tree; 811 void *cookie = NULL; 812 zil_vdev_node_t *zv; 813 zio_t *zio; 814 815 ASSERT(zilog->zl_writer); 816 817 /* 818 * We don't need zl_vdev_lock here because we're the zl_writer, 819 * and all zl_get_data() callbacks are done. 820 */ 821 if (avl_numnodes(t) == 0) 822 return; 823 824 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER); 825 826 zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL); 827 828 while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) { 829 vdev_t *vd = vdev_lookup_top(spa, zv->zv_vdev); 830 if (vd != NULL) 831 zio_flush(zio, vd); 832 kmem_free(zv, sizeof (*zv)); 833 } 834 835 /* 836 * Wait for all the flushes to complete. Not all devices actually 837 * support the DKIOCFLUSHWRITECACHE ioctl, so it's OK if it fails. 838 */ 839 (void) zio_wait(zio); 840 841 spa_config_exit(spa, SCL_STATE, FTAG); 842} 843 844/* 845 * Function called when a log block write completes 846 */ 847static void 848zil_lwb_write_done(zio_t *zio) 849{ 850 lwb_t *lwb = zio->io_private; 851 zilog_t *zilog = lwb->lwb_zilog; 852 dmu_tx_t *tx = lwb->lwb_tx; 853 854 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 855 ASSERT(BP_GET_TYPE(zio->io_bp) == DMU_OT_INTENT_LOG); 856 ASSERT(BP_GET_LEVEL(zio->io_bp) == 0); 857 ASSERT(BP_GET_BYTEORDER(zio->io_bp) == ZFS_HOST_BYTEORDER); 858 ASSERT(!BP_IS_GANG(zio->io_bp)); 859 ASSERT(!BP_IS_HOLE(zio->io_bp)); 860 ASSERT(BP_GET_FILL(zio->io_bp) == 0); 861 862 /* 863 * Ensure the lwb buffer pointer is cleared before releasing 864 * the txg. If we have had an allocation failure and 865 * the txg is waiting to sync then we want want zil_sync() 866 * to remove the lwb so that it's not picked up as the next new 867 * one in zil_commit_writer(). zil_sync() will only remove 868 * the lwb if lwb_buf is null. 869 */ 870 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 871 mutex_enter(&zilog->zl_lock); 872 lwb->lwb_buf = NULL; 873 lwb->lwb_tx = NULL; 874 mutex_exit(&zilog->zl_lock); 875 876 /* 877 * Now that we've written this log block, we have a stable pointer 878 * to the next block in the chain, so it's OK to let the txg in 879 * which we allocated the next block sync. 880 */ 881 dmu_tx_commit(tx); 882} 883 884/* 885 * Initialize the io for a log block. 886 */ 887static void 888zil_lwb_write_init(zilog_t *zilog, lwb_t *lwb) 889{ 890 zbookmark_phys_t zb; 891 892 SET_BOOKMARK(&zb, lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_OBJSET], 893 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, 894 lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_SEQ]); 895 896 if (zilog->zl_root_zio == NULL) { 897 zilog->zl_root_zio = zio_root(zilog->zl_spa, NULL, NULL, 898 ZIO_FLAG_CANFAIL); 899 } 900 if (lwb->lwb_zio == NULL) { 901 lwb->lwb_zio = zio_rewrite(zilog->zl_root_zio, zilog->zl_spa, 902 0, &lwb->lwb_blk, lwb->lwb_buf, BP_GET_LSIZE(&lwb->lwb_blk), 903 zil_lwb_write_done, lwb, ZIO_PRIORITY_SYNC_WRITE, 904 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE, &zb); 905 } 906} 907 908/* 909 * Define a limited set of intent log block sizes. 910 * 911 * These must be a multiple of 4KB. Note only the amount used (again 912 * aligned to 4KB) actually gets written. However, we can't always just 913 * allocate SPA_OLD_MAXBLOCKSIZE as the slog space could be exhausted. 914 */ 915uint64_t zil_block_buckets[] = { 916 4096, /* non TX_WRITE */ 917 8192+4096, /* data base */ 918 32*1024 + 4096, /* NFS writes */ 919 UINT64_MAX 920}; 921 922/* 923 * Use the slog as long as the logbias is 'latency' and the current commit size 924 * is less than the limit or the total list size is less than 2X the limit. 925 * Limit checking is disabled by setting zil_slog_limit to UINT64_MAX. 926 */ 927uint64_t zil_slog_limit = 1024 * 1024; 928#define USE_SLOG(zilog) (((zilog)->zl_logbias == ZFS_LOGBIAS_LATENCY) && \ 929 (((zilog)->zl_cur_used < zil_slog_limit) || \ 930 ((zilog)->zl_itx_list_sz < (zil_slog_limit << 1)))) 931 932/* 933 * Start a log block write and advance to the next log block. 934 * Calls are serialized. 935 */ 936static lwb_t * 937zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb) 938{ 939 lwb_t *nlwb = NULL; 940 zil_chain_t *zilc; 941 spa_t *spa = zilog->zl_spa; 942 blkptr_t *bp; 943 dmu_tx_t *tx; 944 uint64_t txg; 945 uint64_t zil_blksz, wsz; 946 int i, error; 947 948 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) { 949 zilc = (zil_chain_t *)lwb->lwb_buf; 950 bp = &zilc->zc_next_blk; 951 } else { 952 zilc = (zil_chain_t *)(lwb->lwb_buf + lwb->lwb_sz); 953 bp = &zilc->zc_next_blk; 954 } 955 956 ASSERT(lwb->lwb_nused <= lwb->lwb_sz); 957 958 /* 959 * Allocate the next block and save its address in this block 960 * before writing it in order to establish the log chain. 961 * Note that if the allocation of nlwb synced before we wrote 962 * the block that points at it (lwb), we'd leak it if we crashed. 963 * Therefore, we don't do dmu_tx_commit() until zil_lwb_write_done(). 964 * We dirty the dataset to ensure that zil_sync() will be called 965 * to clean up in the event of allocation failure or I/O failure. 966 */ 967 tx = dmu_tx_create(zilog->zl_os); 968 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 969 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 970 txg = dmu_tx_get_txg(tx); 971 972 lwb->lwb_tx = tx; 973 974 /* 975 * Log blocks are pre-allocated. Here we select the size of the next 976 * block, based on size used in the last block. 977 * - first find the smallest bucket that will fit the block from a 978 * limited set of block sizes. This is because it's faster to write 979 * blocks allocated from the same metaslab as they are adjacent or 980 * close. 981 * - next find the maximum from the new suggested size and an array of 982 * previous sizes. This lessens a picket fence effect of wrongly 983 * guesssing the size if we have a stream of say 2k, 64k, 2k, 64k 984 * requests. 985 * 986 * Note we only write what is used, but we can't just allocate 987 * the maximum block size because we can exhaust the available 988 * pool log space. 989 */ 990 zil_blksz = zilog->zl_cur_used + sizeof (zil_chain_t); 991 for (i = 0; zil_blksz > zil_block_buckets[i]; i++) 992 continue; 993 zil_blksz = zil_block_buckets[i]; 994 if (zil_blksz == UINT64_MAX) 995 zil_blksz = SPA_OLD_MAXBLOCKSIZE; 996 zilog->zl_prev_blks[zilog->zl_prev_rotor] = zil_blksz; 997 for (i = 0; i < ZIL_PREV_BLKS; i++) 998 zil_blksz = MAX(zil_blksz, zilog->zl_prev_blks[i]); 999 zilog->zl_prev_rotor = (zilog->zl_prev_rotor + 1) & (ZIL_PREV_BLKS - 1); 1000 1001 BP_ZERO(bp); 1002 /* pass the old blkptr in order to spread log blocks across devs */ 1003 error = zio_alloc_zil(spa, txg, bp, &lwb->lwb_blk, zil_blksz, 1004 USE_SLOG(zilog)); 1005 if (error == 0) { 1006 ASSERT3U(bp->blk_birth, ==, txg); 1007 bp->blk_cksum = lwb->lwb_blk.blk_cksum; 1008 bp->blk_cksum.zc_word[ZIL_ZC_SEQ]++; 1009 1010 /* 1011 * Allocate a new log write buffer (lwb). 1012 */ 1013 nlwb = zil_alloc_lwb(zilog, bp, txg); 1014 1015 /* Record the block for later vdev flushing */ 1016 zil_add_block(zilog, &lwb->lwb_blk); 1017 } 1018 1019 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) { 1020 /* For Slim ZIL only write what is used. */ 1021 wsz = P2ROUNDUP_TYPED(lwb->lwb_nused, ZIL_MIN_BLKSZ, uint64_t); 1022 ASSERT3U(wsz, <=, lwb->lwb_sz); 1023 zio_shrink(lwb->lwb_zio, wsz); 1024 1025 } else { 1026 wsz = lwb->lwb_sz; 1027 } 1028 1029 zilc->zc_pad = 0; 1030 zilc->zc_nused = lwb->lwb_nused; 1031 zilc->zc_eck.zec_cksum = lwb->lwb_blk.blk_cksum; 1032 1033 /* 1034 * clear unused data for security 1035 */ 1036 bzero(lwb->lwb_buf + lwb->lwb_nused, wsz - lwb->lwb_nused); 1037 1038 zio_nowait(lwb->lwb_zio); /* Kick off the write for the old log block */ 1039 1040 /* 1041 * If there was an allocation failure then nlwb will be null which 1042 * forces a txg_wait_synced(). 1043 */ 1044 return (nlwb); 1045} 1046 1047static lwb_t * 1048zil_lwb_commit(zilog_t *zilog, itx_t *itx, lwb_t *lwb) 1049{ 1050 lr_t *lrc = &itx->itx_lr; /* common log record */ 1051 lr_write_t *lrw = (lr_write_t *)lrc; 1052 char *lr_buf; 1053 uint64_t txg = lrc->lrc_txg; 1054 uint64_t reclen = lrc->lrc_reclen; 1055 uint64_t dlen = 0; 1056 1057 if (lwb == NULL) 1058 return (NULL); 1059 1060 ASSERT(lwb->lwb_buf != NULL); 1061 ASSERT(zilog_is_dirty(zilog) || 1062 spa_freeze_txg(zilog->zl_spa) != UINT64_MAX); 1063 1064 if (lrc->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY) 1065 dlen = P2ROUNDUP_TYPED( 1066 lrw->lr_length, sizeof (uint64_t), uint64_t); 1067 1068 zilog->zl_cur_used += (reclen + dlen); 1069 1070 zil_lwb_write_init(zilog, lwb); 1071 1072 /* 1073 * If this record won't fit in the current log block, start a new one. 1074 */ 1075 if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) { 1076 lwb = zil_lwb_write_start(zilog, lwb); 1077 if (lwb == NULL) 1078 return (NULL); 1079 zil_lwb_write_init(zilog, lwb); 1080 ASSERT(LWB_EMPTY(lwb)); 1081 if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) { 1082 txg_wait_synced(zilog->zl_dmu_pool, txg); 1083 return (lwb); 1084 } 1085 } 1086 1087 lr_buf = lwb->lwb_buf + lwb->lwb_nused; 1088 bcopy(lrc, lr_buf, reclen); 1089 lrc = (lr_t *)lr_buf; 1090 lrw = (lr_write_t *)lrc; 1091 1092 /* 1093 * If it's a write, fetch the data or get its blkptr as appropriate. 1094 */ 1095 if (lrc->lrc_txtype == TX_WRITE) { 1096 if (txg > spa_freeze_txg(zilog->zl_spa)) 1097 txg_wait_synced(zilog->zl_dmu_pool, txg); 1098 if (itx->itx_wr_state != WR_COPIED) { 1099 char *dbuf; 1100 int error; 1101 1102 if (dlen) { 1103 ASSERT(itx->itx_wr_state == WR_NEED_COPY); 1104 dbuf = lr_buf + reclen; 1105 lrw->lr_common.lrc_reclen += dlen; 1106 } else { 1107 ASSERT(itx->itx_wr_state == WR_INDIRECT); 1108 dbuf = NULL; 1109 } 1110 error = zilog->zl_get_data( 1111 itx->itx_private, lrw, dbuf, lwb->lwb_zio); 1112 if (error == EIO) { 1113 txg_wait_synced(zilog->zl_dmu_pool, txg); 1114 return (lwb); 1115 } 1116 if (error != 0) { 1117 ASSERT(error == ENOENT || error == EEXIST || 1118 error == EALREADY); 1119 return (lwb); 1120 } 1121 } 1122 } 1123 1124 /* 1125 * We're actually making an entry, so update lrc_seq to be the 1126 * log record sequence number. Note that this is generally not 1127 * equal to the itx sequence number because not all transactions 1128 * are synchronous, and sometimes spa_sync() gets there first. 1129 */ 1130 lrc->lrc_seq = ++zilog->zl_lr_seq; /* we are single threaded */ 1131 lwb->lwb_nused += reclen + dlen; 1132 lwb->lwb_max_txg = MAX(lwb->lwb_max_txg, txg); 1133 ASSERT3U(lwb->lwb_nused, <=, lwb->lwb_sz); 1134 ASSERT0(P2PHASE(lwb->lwb_nused, sizeof (uint64_t))); 1135 1136 return (lwb); 1137} 1138 1139itx_t * 1140zil_itx_create(uint64_t txtype, size_t lrsize) 1141{ 1142 itx_t *itx; 1143 1144 lrsize = P2ROUNDUP_TYPED(lrsize, sizeof (uint64_t), size_t); 1145 1146 itx = kmem_alloc(offsetof(itx_t, itx_lr) + lrsize, KM_SLEEP); 1147 itx->itx_lr.lrc_txtype = txtype; 1148 itx->itx_lr.lrc_reclen = lrsize; 1149 itx->itx_sod = lrsize; /* if write & WR_NEED_COPY will be increased */ 1150 itx->itx_lr.lrc_seq = 0; /* defensive */ 1151 itx->itx_sync = B_TRUE; /* default is synchronous */ 1152 1153 return (itx); 1154} 1155 1156void 1157zil_itx_destroy(itx_t *itx) 1158{ 1159 kmem_free(itx, offsetof(itx_t, itx_lr) + itx->itx_lr.lrc_reclen); 1160} 1161 1162/* 1163 * Free up the sync and async itxs. The itxs_t has already been detached 1164 * so no locks are needed. 1165 */ 1166static void 1167zil_itxg_clean(itxs_t *itxs) 1168{ 1169 itx_t *itx; 1170 list_t *list; 1171 avl_tree_t *t; 1172 void *cookie; 1173 itx_async_node_t *ian; 1174 1175 list = &itxs->i_sync_list; 1176 while ((itx = list_head(list)) != NULL) { 1177 list_remove(list, itx); 1178 kmem_free(itx, offsetof(itx_t, itx_lr) + 1179 itx->itx_lr.lrc_reclen); 1180 } 1181 1182 cookie = NULL; 1183 t = &itxs->i_async_tree; 1184 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) { 1185 list = &ian->ia_list; 1186 while ((itx = list_head(list)) != NULL) { 1187 list_remove(list, itx); 1188 kmem_free(itx, offsetof(itx_t, itx_lr) + 1189 itx->itx_lr.lrc_reclen); 1190 } 1191 list_destroy(list); 1192 kmem_free(ian, sizeof (itx_async_node_t)); 1193 } 1194 avl_destroy(t); 1195 1196 kmem_free(itxs, sizeof (itxs_t)); 1197} 1198 1199static int 1200zil_aitx_compare(const void *x1, const void *x2) 1201{ 1202 const uint64_t o1 = ((itx_async_node_t *)x1)->ia_foid; 1203 const uint64_t o2 = ((itx_async_node_t *)x2)->ia_foid; 1204 1205 if (o1 < o2) 1206 return (-1); 1207 if (o1 > o2) 1208 return (1); 1209 1210 return (0); 1211} 1212 1213/* 1214 * Remove all async itx with the given oid. 1215 */ 1216static void 1217zil_remove_async(zilog_t *zilog, uint64_t oid) 1218{ 1219 uint64_t otxg, txg; 1220 itx_async_node_t *ian; 1221 avl_tree_t *t; 1222 avl_index_t where; 1223 list_t clean_list; 1224 itx_t *itx; 1225 1226 ASSERT(oid != 0); 1227 list_create(&clean_list, sizeof (itx_t), offsetof(itx_t, itx_node)); 1228 1229 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1230 otxg = ZILTEST_TXG; 1231 else 1232 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1233 1234 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1235 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1236 1237 mutex_enter(&itxg->itxg_lock); 1238 if (itxg->itxg_txg != txg) { 1239 mutex_exit(&itxg->itxg_lock); 1240 continue; 1241 } 1242 1243 /* 1244 * Locate the object node and append its list. 1245 */ 1246 t = &itxg->itxg_itxs->i_async_tree; 1247 ian = avl_find(t, &oid, &where); 1248 if (ian != NULL) 1249 list_move_tail(&clean_list, &ian->ia_list); 1250 mutex_exit(&itxg->itxg_lock); 1251 } 1252 while ((itx = list_head(&clean_list)) != NULL) { 1253 list_remove(&clean_list, itx); 1254 kmem_free(itx, offsetof(itx_t, itx_lr) + 1255 itx->itx_lr.lrc_reclen); 1256 } 1257 list_destroy(&clean_list); 1258} 1259 1260void 1261zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx) 1262{ 1263 uint64_t txg; 1264 itxg_t *itxg; 1265 itxs_t *itxs, *clean = NULL; 1266 1267 /* 1268 * Object ids can be re-instantiated in the next txg so 1269 * remove any async transactions to avoid future leaks. 1270 * This can happen if a fsync occurs on the re-instantiated 1271 * object for a WR_INDIRECT or WR_NEED_COPY write, which gets 1272 * the new file data and flushes a write record for the old object. 1273 */ 1274 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_REMOVE) 1275 zil_remove_async(zilog, itx->itx_oid); 1276 1277 /* 1278 * Ensure the data of a renamed file is committed before the rename. 1279 */ 1280 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_RENAME) 1281 zil_async_to_sync(zilog, itx->itx_oid); 1282 1283 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) 1284 txg = ZILTEST_TXG; 1285 else 1286 txg = dmu_tx_get_txg(tx); 1287 1288 itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1289 mutex_enter(&itxg->itxg_lock); 1290 itxs = itxg->itxg_itxs; 1291 if (itxg->itxg_txg != txg) { 1292 if (itxs != NULL) { 1293 /* 1294 * The zil_clean callback hasn't got around to cleaning 1295 * this itxg. Save the itxs for release below. 1296 * This should be rare. 1297 */ 1298 atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod); 1299 itxg->itxg_sod = 0; 1300 clean = itxg->itxg_itxs; 1301 } 1302 ASSERT(itxg->itxg_sod == 0); 1303 itxg->itxg_txg = txg; 1304 itxs = itxg->itxg_itxs = kmem_zalloc(sizeof (itxs_t), KM_SLEEP); 1305 1306 list_create(&itxs->i_sync_list, sizeof (itx_t), 1307 offsetof(itx_t, itx_node)); 1308 avl_create(&itxs->i_async_tree, zil_aitx_compare, 1309 sizeof (itx_async_node_t), 1310 offsetof(itx_async_node_t, ia_node)); 1311 } 1312 if (itx->itx_sync) { 1313 list_insert_tail(&itxs->i_sync_list, itx); 1314 atomic_add_64(&zilog->zl_itx_list_sz, itx->itx_sod); 1315 itxg->itxg_sod += itx->itx_sod; 1316 } else { 1317 avl_tree_t *t = &itxs->i_async_tree; 1318 uint64_t foid = ((lr_ooo_t *)&itx->itx_lr)->lr_foid; 1319 itx_async_node_t *ian; 1320 avl_index_t where; 1321 1322 ian = avl_find(t, &foid, &where); 1323 if (ian == NULL) { 1324 ian = kmem_alloc(sizeof (itx_async_node_t), KM_SLEEP); 1325 list_create(&ian->ia_list, sizeof (itx_t), 1326 offsetof(itx_t, itx_node)); 1327 ian->ia_foid = foid; 1328 avl_insert(t, ian, where); 1329 } 1330 list_insert_tail(&ian->ia_list, itx); 1331 } 1332 1333 itx->itx_lr.lrc_txg = dmu_tx_get_txg(tx); 1334 zilog_dirty(zilog, txg); 1335 mutex_exit(&itxg->itxg_lock); 1336 1337 /* Release the old itxs now we've dropped the lock */ 1338 if (clean != NULL) 1339 zil_itxg_clean(clean); 1340} 1341 1342/* 1343 * If there are any in-memory intent log transactions which have now been 1344 * synced then start up a taskq to free them. We should only do this after we 1345 * have written out the uberblocks (i.e. txg has been comitted) so that 1346 * don't inadvertently clean out in-memory log records that would be required 1347 * by zil_commit(). 1348 */ 1349void 1350zil_clean(zilog_t *zilog, uint64_t synced_txg) 1351{ 1352 itxg_t *itxg = &zilog->zl_itxg[synced_txg & TXG_MASK]; 1353 itxs_t *clean_me; 1354 1355 mutex_enter(&itxg->itxg_lock); 1356 if (itxg->itxg_itxs == NULL || itxg->itxg_txg == ZILTEST_TXG) { 1357 mutex_exit(&itxg->itxg_lock); 1358 return; 1359 } 1360 ASSERT3U(itxg->itxg_txg, <=, synced_txg); 1361 ASSERT(itxg->itxg_txg != 0); 1362 ASSERT(zilog->zl_clean_taskq != NULL); 1363 atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod); 1364 itxg->itxg_sod = 0; 1365 clean_me = itxg->itxg_itxs; 1366 itxg->itxg_itxs = NULL; 1367 itxg->itxg_txg = 0; 1368 mutex_exit(&itxg->itxg_lock); 1369 /* 1370 * Preferably start a task queue to free up the old itxs but 1371 * if taskq_dispatch can't allocate resources to do that then 1372 * free it in-line. This should be rare. Note, using TQ_SLEEP 1373 * created a bad performance problem. 1374 */ 1375 if (taskq_dispatch(zilog->zl_clean_taskq, 1376 (void (*)(void *))zil_itxg_clean, clean_me, TQ_NOSLEEP) == 0) 1377 zil_itxg_clean(clean_me); 1378} 1379 1380/* 1381 * Get the list of itxs to commit into zl_itx_commit_list. 1382 */ 1383static void 1384zil_get_commit_list(zilog_t *zilog) 1385{ 1386 uint64_t otxg, txg; 1387 list_t *commit_list = &zilog->zl_itx_commit_list; 1388 uint64_t push_sod = 0; 1389 1390 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1391 otxg = ZILTEST_TXG; 1392 else 1393 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1394 1395 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1396 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1397 1398 mutex_enter(&itxg->itxg_lock); 1399 if (itxg->itxg_txg != txg) { 1400 mutex_exit(&itxg->itxg_lock); 1401 continue; 1402 } 1403 1404 list_move_tail(commit_list, &itxg->itxg_itxs->i_sync_list); 1405 push_sod += itxg->itxg_sod; 1406 itxg->itxg_sod = 0; 1407 1408 mutex_exit(&itxg->itxg_lock); 1409 } 1410 atomic_add_64(&zilog->zl_itx_list_sz, -push_sod); 1411} 1412 1413/* 1414 * Move the async itxs for a specified object to commit into sync lists. 1415 */ 1416static void 1417zil_async_to_sync(zilog_t *zilog, uint64_t foid) 1418{ 1419 uint64_t otxg, txg; 1420 itx_async_node_t *ian; 1421 avl_tree_t *t; 1422 avl_index_t where; 1423 1424 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1425 otxg = ZILTEST_TXG; 1426 else 1427 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1428 1429 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1430 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1431 1432 mutex_enter(&itxg->itxg_lock); 1433 if (itxg->itxg_txg != txg) { 1434 mutex_exit(&itxg->itxg_lock); 1435 continue; 1436 } 1437 1438 /* 1439 * If a foid is specified then find that node and append its 1440 * list. Otherwise walk the tree appending all the lists 1441 * to the sync list. We add to the end rather than the 1442 * beginning to ensure the create has happened. 1443 */ 1444 t = &itxg->itxg_itxs->i_async_tree; 1445 if (foid != 0) { 1446 ian = avl_find(t, &foid, &where); 1447 if (ian != NULL) { 1448 list_move_tail(&itxg->itxg_itxs->i_sync_list, 1449 &ian->ia_list); 1450 } 1451 } else { 1452 void *cookie = NULL; 1453 1454 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) { 1455 list_move_tail(&itxg->itxg_itxs->i_sync_list, 1456 &ian->ia_list); 1457 list_destroy(&ian->ia_list); 1458 kmem_free(ian, sizeof (itx_async_node_t)); 1459 } 1460 } 1461 mutex_exit(&itxg->itxg_lock); 1462 } 1463} 1464 1465static void 1466zil_commit_writer(zilog_t *zilog) 1467{ 1468 uint64_t txg; 1469 itx_t *itx; 1470 lwb_t *lwb; 1471 spa_t *spa = zilog->zl_spa; 1472 int error = 0; 1473 1474 ASSERT(zilog->zl_root_zio == NULL); 1475 1476 mutex_exit(&zilog->zl_lock); 1477 1478 zil_get_commit_list(zilog); 1479 1480 /* 1481 * Return if there's nothing to commit before we dirty the fs by 1482 * calling zil_create(). 1483 */ 1484 if (list_head(&zilog->zl_itx_commit_list) == NULL) { 1485 mutex_enter(&zilog->zl_lock); 1486 return; 1487 } 1488 1489 if (zilog->zl_suspend) { 1490 lwb = NULL; 1491 } else { 1492 lwb = list_tail(&zilog->zl_lwb_list); 1493 if (lwb == NULL) 1494 lwb = zil_create(zilog); 1495 } 1496 1497 DTRACE_PROBE1(zil__cw1, zilog_t *, zilog); 1498 while (itx = list_head(&zilog->zl_itx_commit_list)) { 1499 txg = itx->itx_lr.lrc_txg; 1500 ASSERT(txg); 1501 1502 if (txg > spa_last_synced_txg(spa) || txg > spa_freeze_txg(spa)) 1503 lwb = zil_lwb_commit(zilog, itx, lwb); 1504 list_remove(&zilog->zl_itx_commit_list, itx); 1505 kmem_free(itx, offsetof(itx_t, itx_lr) 1506 + itx->itx_lr.lrc_reclen); 1507 } 1508 DTRACE_PROBE1(zil__cw2, zilog_t *, zilog); 1509 1510 /* write the last block out */ 1511 if (lwb != NULL && lwb->lwb_zio != NULL) 1512 lwb = zil_lwb_write_start(zilog, lwb); 1513 1514 zilog->zl_cur_used = 0; 1515 1516 /* 1517 * Wait if necessary for the log blocks to be on stable storage. 1518 */ 1519 if (zilog->zl_root_zio) { 1520 error = zio_wait(zilog->zl_root_zio); 1521 zilog->zl_root_zio = NULL; 1522 zil_flush_vdevs(zilog); 1523 } 1524 1525 if (error || lwb == NULL) 1526 txg_wait_synced(zilog->zl_dmu_pool, 0); 1527 1528 mutex_enter(&zilog->zl_lock); 1529 1530 /* 1531 * Remember the highest committed log sequence number for ztest. 1532 * We only update this value when all the log writes succeeded, 1533 * because ztest wants to ASSERT that it got the whole log chain. 1534 */ 1535 if (error == 0 && lwb != NULL) 1536 zilog->zl_commit_lr_seq = zilog->zl_lr_seq; 1537} 1538 1539/* 1540 * Commit zfs transactions to stable storage. 1541 * If foid is 0 push out all transactions, otherwise push only those 1542 * for that object or might reference that object. 1543 * 1544 * itxs are committed in batches. In a heavily stressed zil there will be 1545 * a commit writer thread who is writing out a bunch of itxs to the log 1546 * for a set of committing threads (cthreads) in the same batch as the writer. 1547 * Those cthreads are all waiting on the same cv for that batch. 1548 * 1549 * There will also be a different and growing batch of threads that are 1550 * waiting to commit (qthreads). When the committing batch completes 1551 * a transition occurs such that the cthreads exit and the qthreads become 1552 * cthreads. One of the new cthreads becomes the writer thread for the 1553 * batch. Any new threads arriving become new qthreads. 1554 * 1555 * Only 2 condition variables are needed and there's no transition 1556 * between the two cvs needed. They just flip-flop between qthreads 1557 * and cthreads. 1558 * 1559 * Using this scheme we can efficiently wakeup up only those threads 1560 * that have been committed. 1561 */ 1562void 1563zil_commit(zilog_t *zilog, uint64_t foid) 1564{ 1565 uint64_t mybatch; 1566 1567 if (zilog->zl_sync == ZFS_SYNC_DISABLED) 1568 return; 1569 1570 /* move the async itxs for the foid to the sync queues */ 1571 zil_async_to_sync(zilog, foid); 1572 1573 mutex_enter(&zilog->zl_lock); 1574 mybatch = zilog->zl_next_batch; 1575 while (zilog->zl_writer) { 1576 cv_wait(&zilog->zl_cv_batch[mybatch & 1], &zilog->zl_lock); 1577 if (mybatch <= zilog->zl_com_batch) { 1578 mutex_exit(&zilog->zl_lock); 1579 return; 1580 } 1581 } 1582 1583 zilog->zl_next_batch++; 1584 zilog->zl_writer = B_TRUE; 1585 zil_commit_writer(zilog); 1586 zilog->zl_com_batch = mybatch; 1587 zilog->zl_writer = B_FALSE; 1588 mutex_exit(&zilog->zl_lock); 1589 1590 /* wake up one thread to become the next writer */ 1591 cv_signal(&zilog->zl_cv_batch[(mybatch+1) & 1]); 1592 1593 /* wake up all threads waiting for this batch to be committed */ 1594 cv_broadcast(&zilog->zl_cv_batch[mybatch & 1]); 1595} 1596 1597/* 1598 * Called in syncing context to free committed log blocks and update log header. 1599 */ 1600void 1601zil_sync(zilog_t *zilog, dmu_tx_t *tx) 1602{ 1603 zil_header_t *zh = zil_header_in_syncing_context(zilog); 1604 uint64_t txg = dmu_tx_get_txg(tx); 1605 spa_t *spa = zilog->zl_spa; 1606 uint64_t *replayed_seq = &zilog->zl_replayed_seq[txg & TXG_MASK]; 1607 lwb_t *lwb; 1608 1609 /* 1610 * We don't zero out zl_destroy_txg, so make sure we don't try 1611 * to destroy it twice. 1612 */ 1613 if (spa_sync_pass(spa) != 1) 1614 return; 1615 1616 mutex_enter(&zilog->zl_lock); 1617 1618 ASSERT(zilog->zl_stop_sync == 0); 1619 1620 if (*replayed_seq != 0) { 1621 ASSERT(zh->zh_replay_seq < *replayed_seq); 1622 zh->zh_replay_seq = *replayed_seq; 1623 *replayed_seq = 0; 1624 } 1625 1626 if (zilog->zl_destroy_txg == txg) { 1627 blkptr_t blk = zh->zh_log; 1628 1629 ASSERT(list_head(&zilog->zl_lwb_list) == NULL); 1630 1631 bzero(zh, sizeof (zil_header_t)); 1632 bzero(zilog->zl_replayed_seq, sizeof (zilog->zl_replayed_seq)); 1633 1634 if (zilog->zl_keep_first) { 1635 /* 1636 * If this block was part of log chain that couldn't 1637 * be claimed because a device was missing during 1638 * zil_claim(), but that device later returns, 1639 * then this block could erroneously appear valid. 1640 * To guard against this, assign a new GUID to the new 1641 * log chain so it doesn't matter what blk points to. 1642 */ 1643 zil_init_log_chain(zilog, &blk); 1644 zh->zh_log = blk; 1645 } 1646 } 1647 1648 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { 1649 zh->zh_log = lwb->lwb_blk; 1650 if (lwb->lwb_buf != NULL || lwb->lwb_max_txg > txg) 1651 break; 1652 list_remove(&zilog->zl_lwb_list, lwb); 1653 zio_free_zil(spa, txg, &lwb->lwb_blk); 1654 kmem_cache_free(zil_lwb_cache, lwb); 1655 1656 /* 1657 * If we don't have anything left in the lwb list then 1658 * we've had an allocation failure and we need to zero 1659 * out the zil_header blkptr so that we don't end 1660 * up freeing the same block twice. 1661 */ 1662 if (list_head(&zilog->zl_lwb_list) == NULL) 1663 BP_ZERO(&zh->zh_log); 1664 } 1665 mutex_exit(&zilog->zl_lock); 1666} 1667 1668void 1669zil_init(void) 1670{ 1671 zil_lwb_cache = kmem_cache_create("zil_lwb_cache", 1672 sizeof (struct lwb), 0, NULL, NULL, NULL, NULL, NULL, 0); 1673} 1674 1675void 1676zil_fini(void) 1677{ 1678 kmem_cache_destroy(zil_lwb_cache); 1679} 1680 1681void 1682zil_set_sync(zilog_t *zilog, uint64_t sync) 1683{ 1684 zilog->zl_sync = sync; 1685} 1686 1687void 1688zil_set_logbias(zilog_t *zilog, uint64_t logbias) 1689{ 1690 zilog->zl_logbias = logbias; 1691} 1692 1693zilog_t * 1694zil_alloc(objset_t *os, zil_header_t *zh_phys) 1695{ 1696 zilog_t *zilog; 1697 1698 zilog = kmem_zalloc(sizeof (zilog_t), KM_SLEEP); 1699 1700 zilog->zl_header = zh_phys; 1701 zilog->zl_os = os; 1702 zilog->zl_spa = dmu_objset_spa(os); 1703 zilog->zl_dmu_pool = dmu_objset_pool(os); 1704 zilog->zl_destroy_txg = TXG_INITIAL - 1; 1705 zilog->zl_logbias = dmu_objset_logbias(os); 1706 zilog->zl_sync = dmu_objset_syncprop(os); 1707 zilog->zl_next_batch = 1; 1708 1709 mutex_init(&zilog->zl_lock, NULL, MUTEX_DEFAULT, NULL); 1710 1711 for (int i = 0; i < TXG_SIZE; i++) { 1712 mutex_init(&zilog->zl_itxg[i].itxg_lock, NULL, 1713 MUTEX_DEFAULT, NULL); 1714 } 1715 1716 list_create(&zilog->zl_lwb_list, sizeof (lwb_t), 1717 offsetof(lwb_t, lwb_node)); 1718 1719 list_create(&zilog->zl_itx_commit_list, sizeof (itx_t), 1720 offsetof(itx_t, itx_node)); 1721 1722 mutex_init(&zilog->zl_vdev_lock, NULL, MUTEX_DEFAULT, NULL); 1723 1724 avl_create(&zilog->zl_vdev_tree, zil_vdev_compare, 1725 sizeof (zil_vdev_node_t), offsetof(zil_vdev_node_t, zv_node)); 1726 1727 cv_init(&zilog->zl_cv_writer, NULL, CV_DEFAULT, NULL); 1728 cv_init(&zilog->zl_cv_suspend, NULL, CV_DEFAULT, NULL); 1729 cv_init(&zilog->zl_cv_batch[0], NULL, CV_DEFAULT, NULL); 1730 cv_init(&zilog->zl_cv_batch[1], NULL, CV_DEFAULT, NULL); 1731 1732 return (zilog); 1733} 1734 1735void 1736zil_free(zilog_t *zilog) 1737{ 1738 zilog->zl_stop_sync = 1; 1739 1740 ASSERT0(zilog->zl_suspend); 1741 ASSERT0(zilog->zl_suspending); 1742 1743 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 1744 list_destroy(&zilog->zl_lwb_list); 1745 1746 avl_destroy(&zilog->zl_vdev_tree); 1747 mutex_destroy(&zilog->zl_vdev_lock); 1748 1749 ASSERT(list_is_empty(&zilog->zl_itx_commit_list)); 1750 list_destroy(&zilog->zl_itx_commit_list); 1751 1752 for (int i = 0; i < TXG_SIZE; i++) { 1753 /* 1754 * It's possible for an itx to be generated that doesn't dirty 1755 * a txg (e.g. ztest TX_TRUNCATE). So there's no zil_clean() 1756 * callback to remove the entry. We remove those here. 1757 * 1758 * Also free up the ziltest itxs. 1759 */ 1760 if (zilog->zl_itxg[i].itxg_itxs) 1761 zil_itxg_clean(zilog->zl_itxg[i].itxg_itxs); 1762 mutex_destroy(&zilog->zl_itxg[i].itxg_lock); 1763 } 1764 1765 mutex_destroy(&zilog->zl_lock); 1766 1767 cv_destroy(&zilog->zl_cv_writer); 1768 cv_destroy(&zilog->zl_cv_suspend); 1769 cv_destroy(&zilog->zl_cv_batch[0]); 1770 cv_destroy(&zilog->zl_cv_batch[1]); 1771 1772 kmem_free(zilog, sizeof (zilog_t)); 1773} 1774 1775/* 1776 * Open an intent log. 1777 */ 1778zilog_t * 1779zil_open(objset_t *os, zil_get_data_t *get_data) 1780{ 1781 zilog_t *zilog = dmu_objset_zil(os); 1782 1783 ASSERT(zilog->zl_clean_taskq == NULL); 1784 ASSERT(zilog->zl_get_data == NULL); 1785 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 1786 1787 zilog->zl_get_data = get_data; 1788 zilog->zl_clean_taskq = taskq_create("zil_clean", 1, minclsyspri, 1789 2, 2, TASKQ_PREPOPULATE); 1790 1791 return (zilog); 1792} 1793 1794/* 1795 * Close an intent log. 1796 */ 1797void 1798zil_close(zilog_t *zilog) 1799{ 1800 lwb_t *lwb; 1801 uint64_t txg = 0; 1802 1803 zil_commit(zilog, 0); /* commit all itx */ 1804 1805 /* 1806 * The lwb_max_txg for the stubby lwb will reflect the last activity 1807 * for the zil. After a txg_wait_synced() on the txg we know all the 1808 * callbacks have occurred that may clean the zil. Only then can we 1809 * destroy the zl_clean_taskq. 1810 */ 1811 mutex_enter(&zilog->zl_lock); 1812 lwb = list_tail(&zilog->zl_lwb_list); 1813 if (lwb != NULL) 1814 txg = lwb->lwb_max_txg; 1815 mutex_exit(&zilog->zl_lock); 1816 if (txg) 1817 txg_wait_synced(zilog->zl_dmu_pool, txg); 1818 ASSERT(!zilog_is_dirty(zilog)); 1819 1820 taskq_destroy(zilog->zl_clean_taskq); 1821 zilog->zl_clean_taskq = NULL; 1822 zilog->zl_get_data = NULL; 1823 1824 /* 1825 * We should have only one LWB left on the list; remove it now. 1826 */ 1827 mutex_enter(&zilog->zl_lock); 1828 lwb = list_head(&zilog->zl_lwb_list); 1829 if (lwb != NULL) { 1830 ASSERT(lwb == list_tail(&zilog->zl_lwb_list)); 1831 list_remove(&zilog->zl_lwb_list, lwb); 1832 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 1833 kmem_cache_free(zil_lwb_cache, lwb); 1834 } 1835 mutex_exit(&zilog->zl_lock); 1836} 1837 1838static char *suspend_tag = "zil suspending"; 1839 1840/* 1841 * Suspend an intent log. While in suspended mode, we still honor 1842 * synchronous semantics, but we rely on txg_wait_synced() to do it. 1843 * On old version pools, we suspend the log briefly when taking a 1844 * snapshot so that it will have an empty intent log. 1845 * 1846 * Long holds are not really intended to be used the way we do here -- 1847 * held for such a short time. A concurrent caller of dsl_dataset_long_held() 1848 * could fail. Therefore we take pains to only put a long hold if it is 1849 * actually necessary. Fortunately, it will only be necessary if the 1850 * objset is currently mounted (or the ZVOL equivalent). In that case it 1851 * will already have a long hold, so we are not really making things any worse. 1852 * 1853 * Ideally, we would locate the existing long-holder (i.e. the zfsvfs_t or 1854 * zvol_state_t), and use their mechanism to prevent their hold from being 1855 * dropped (e.g. VFS_HOLD()). However, that would be even more pain for 1856 * very little gain. 1857 * 1858 * if cookiep == NULL, this does both the suspend & resume. 1859 * Otherwise, it returns with the dataset "long held", and the cookie 1860 * should be passed into zil_resume(). 1861 */ 1862int 1863zil_suspend(const char *osname, void **cookiep) 1864{ 1865 objset_t *os; 1866 zilog_t *zilog; 1867 const zil_header_t *zh; 1868 int error; 1869 1870 error = dmu_objset_hold(osname, suspend_tag, &os); 1871 if (error != 0) 1872 return (error); 1873 zilog = dmu_objset_zil(os); 1874 1875 mutex_enter(&zilog->zl_lock); 1876 zh = zilog->zl_header; 1877 1878 if (zh->zh_flags & ZIL_REPLAY_NEEDED) { /* unplayed log */ 1879 mutex_exit(&zilog->zl_lock); 1880 dmu_objset_rele(os, suspend_tag); 1881 return (SET_ERROR(EBUSY)); 1882 } 1883 1884 /* 1885 * Don't put a long hold in the cases where we can avoid it. This 1886 * is when there is no cookie so we are doing a suspend & resume 1887 * (i.e. called from zil_vdev_offline()), and there's nothing to do 1888 * for the suspend because it's already suspended, or there's no ZIL. 1889 */ 1890 if (cookiep == NULL && !zilog->zl_suspending && 1891 (zilog->zl_suspend > 0 || BP_IS_HOLE(&zh->zh_log))) { 1892 mutex_exit(&zilog->zl_lock); 1893 dmu_objset_rele(os, suspend_tag); 1894 return (0); 1895 } 1896 1897 dsl_dataset_long_hold(dmu_objset_ds(os), suspend_tag); 1898 dsl_pool_rele(dmu_objset_pool(os), suspend_tag); 1899 1900 zilog->zl_suspend++; 1901 1902 if (zilog->zl_suspend > 1) { 1903 /* 1904 * Someone else is already suspending it. 1905 * Just wait for them to finish. 1906 */ 1907 1908 while (zilog->zl_suspending) 1909 cv_wait(&zilog->zl_cv_suspend, &zilog->zl_lock); 1910 mutex_exit(&zilog->zl_lock); 1911 1912 if (cookiep == NULL) 1913 zil_resume(os); 1914 else 1915 *cookiep = os; 1916 return (0); 1917 } 1918 1919 /* 1920 * If there is no pointer to an on-disk block, this ZIL must not 1921 * be active (e.g. filesystem not mounted), so there's nothing 1922 * to clean up. 1923 */ 1924 if (BP_IS_HOLE(&zh->zh_log)) { 1925 ASSERT(cookiep != NULL); /* fast path already handled */ 1926 1927 *cookiep = os; 1928 mutex_exit(&zilog->zl_lock); 1929 return (0); 1930 } 1931 1932 zilog->zl_suspending = B_TRUE; 1933 mutex_exit(&zilog->zl_lock); 1934 1935 zil_commit(zilog, 0); 1936 1937 zil_destroy(zilog, B_FALSE); 1938 1939 mutex_enter(&zilog->zl_lock); 1940 zilog->zl_suspending = B_FALSE; 1941 cv_broadcast(&zilog->zl_cv_suspend); 1942 mutex_exit(&zilog->zl_lock); 1943 1944 if (cookiep == NULL) 1945 zil_resume(os); 1946 else 1947 *cookiep = os; 1948 return (0); 1949} 1950 1951void 1952zil_resume(void *cookie) 1953{ 1954 objset_t *os = cookie; 1955 zilog_t *zilog = dmu_objset_zil(os); 1956 1957 mutex_enter(&zilog->zl_lock); 1958 ASSERT(zilog->zl_suspend != 0); 1959 zilog->zl_suspend--; 1960 mutex_exit(&zilog->zl_lock); 1961 dsl_dataset_long_rele(dmu_objset_ds(os), suspend_tag); 1962 dsl_dataset_rele(dmu_objset_ds(os), suspend_tag); 1963} 1964 1965typedef struct zil_replay_arg { 1966 zil_replay_func_t **zr_replay; 1967 void *zr_arg; 1968 boolean_t zr_byteswap; 1969 char *zr_lr; 1970} zil_replay_arg_t; 1971 1972static int 1973zil_replay_error(zilog_t *zilog, lr_t *lr, int error) 1974{ 1975 char name[MAXNAMELEN]; 1976 1977 zilog->zl_replaying_seq--; /* didn't actually replay this one */ 1978 1979 dmu_objset_name(zilog->zl_os, name); 1980 1981 cmn_err(CE_WARN, "ZFS replay transaction error %d, " 1982 "dataset %s, seq 0x%llx, txtype %llu %s\n", error, name, 1983 (u_longlong_t)lr->lrc_seq, 1984 (u_longlong_t)(lr->lrc_txtype & ~TX_CI), 1985 (lr->lrc_txtype & TX_CI) ? "CI" : ""); 1986 1987 return (error); 1988} 1989 1990static int 1991zil_replay_log_record(zilog_t *zilog, lr_t *lr, void *zra, uint64_t claim_txg) 1992{ 1993 zil_replay_arg_t *zr = zra; 1994 const zil_header_t *zh = zilog->zl_header; 1995 uint64_t reclen = lr->lrc_reclen; 1996 uint64_t txtype = lr->lrc_txtype; 1997 int error = 0; 1998 1999 zilog->zl_replaying_seq = lr->lrc_seq; 2000 2001 if (lr->lrc_seq <= zh->zh_replay_seq) /* already replayed */ 2002 return (0); 2003 2004 if (lr->lrc_txg < claim_txg) /* already committed */ 2005 return (0); 2006 2007 /* Strip case-insensitive bit, still present in log record */ 2008 txtype &= ~TX_CI; 2009 2010 if (txtype == 0 || txtype >= TX_MAX_TYPE) 2011 return (zil_replay_error(zilog, lr, EINVAL)); 2012 2013 /* 2014 * If this record type can be logged out of order, the object 2015 * (lr_foid) may no longer exist. That's legitimate, not an error. 2016 */ 2017 if (TX_OOO(txtype)) { 2018 error = dmu_object_info(zilog->zl_os, 2019 ((lr_ooo_t *)lr)->lr_foid, NULL); 2020 if (error == ENOENT || error == EEXIST) 2021 return (0); 2022 } 2023 2024 /* 2025 * Make a copy of the data so we can revise and extend it. 2026 */ 2027 bcopy(lr, zr->zr_lr, reclen); 2028 2029 /* 2030 * If this is a TX_WRITE with a blkptr, suck in the data. 2031 */ 2032 if (txtype == TX_WRITE && reclen == sizeof (lr_write_t)) { 2033 error = zil_read_log_data(zilog, (lr_write_t *)lr, 2034 zr->zr_lr + reclen); 2035 if (error != 0) 2036 return (zil_replay_error(zilog, lr, error)); 2037 } 2038 2039 /* 2040 * The log block containing this lr may have been byteswapped 2041 * so that we can easily examine common fields like lrc_txtype. 2042 * However, the log is a mix of different record types, and only the 2043 * replay vectors know how to byteswap their records. Therefore, if 2044 * the lr was byteswapped, undo it before invoking the replay vector. 2045 */ 2046 if (zr->zr_byteswap) 2047 byteswap_uint64_array(zr->zr_lr, reclen); 2048 2049 /* 2050 * We must now do two things atomically: replay this log record, 2051 * and update the log header sequence number to reflect the fact that 2052 * we did so. At the end of each replay function the sequence number 2053 * is updated if we are in replay mode. 2054 */ 2055 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, zr->zr_byteswap); 2056 if (error != 0) { 2057 /* 2058 * The DMU's dnode layer doesn't see removes until the txg 2059 * commits, so a subsequent claim can spuriously fail with 2060 * EEXIST. So if we receive any error we try syncing out 2061 * any removes then retry the transaction. Note that we 2062 * specify B_FALSE for byteswap now, so we don't do it twice. 2063 */ 2064 txg_wait_synced(spa_get_dsl(zilog->zl_spa), 0); 2065 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, B_FALSE); 2066 if (error != 0) 2067 return (zil_replay_error(zilog, lr, error)); 2068 } 2069 return (0); 2070} 2071 2072/* ARGSUSED */ 2073static int 2074zil_incr_blks(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg) 2075{ 2076 zilog->zl_replay_blks++; 2077 2078 return (0); 2079} 2080 2081/* 2082 * If this dataset has a non-empty intent log, replay it and destroy it. 2083 */ 2084void 2085zil_replay(objset_t *os, void *arg, zil_replay_func_t *replay_func[TX_MAX_TYPE]) 2086{ 2087 zilog_t *zilog = dmu_objset_zil(os); 2088 const zil_header_t *zh = zilog->zl_header; 2089 zil_replay_arg_t zr; 2090 2091 if ((zh->zh_flags & ZIL_REPLAY_NEEDED) == 0) { 2092 zil_destroy(zilog, B_TRUE); 2093 return; 2094 } 2095 //printf("ZFS: Replaying ZIL on %s...\n", os->os->os_spa->spa_name); 2096 2097 zr.zr_replay = replay_func; 2098 zr.zr_arg = arg; 2099 zr.zr_byteswap = BP_SHOULD_BYTESWAP(&zh->zh_log); 2100 zr.zr_lr = kmem_alloc(2 * SPA_MAXBLOCKSIZE, KM_SLEEP); 2101 2102 /* 2103 * Wait for in-progress removes to sync before starting replay. 2104 */ 2105 txg_wait_synced(zilog->zl_dmu_pool, 0); 2106 2107 zilog->zl_replay = B_TRUE; 2108 zilog->zl_replay_time = ddi_get_lbolt(); 2109 ASSERT(zilog->zl_replay_blks == 0); 2110 (void) zil_parse(zilog, zil_incr_blks, zil_replay_log_record, &zr, 2111 zh->zh_claim_txg); 2112 kmem_free(zr.zr_lr, 2 * SPA_MAXBLOCKSIZE); 2113 2114 zil_destroy(zilog, B_FALSE); 2115 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 2116 zilog->zl_replay = B_FALSE; 2117 //printf("ZFS: Replay of ZIL on %s finished.\n", os->os->os_spa->spa_name); 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