zil.c revision 263397
1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21/* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2013 by Delphix. All rights reserved. 24 */ 25 26/* Portions Copyright 2010 Robert Milkowski */ 27 28#include <sys/zfs_context.h> 29#include <sys/spa.h> 30#include <sys/dmu.h> 31#include <sys/zap.h> 32#include <sys/arc.h> 33#include <sys/stat.h> 34#include <sys/resource.h> 35#include <sys/zil.h> 36#include <sys/zil_impl.h> 37#include <sys/dsl_dataset.h> 38#include <sys/vdev_impl.h> 39#include <sys/dmu_tx.h> 40#include <sys/dsl_pool.h> 41 42/* 43 * The zfs intent log (ZIL) saves transaction records of system calls 44 * that change the file system in memory with enough information 45 * to be able to replay them. These are stored in memory until 46 * either the DMU transaction group (txg) commits them to the stable pool 47 * and they can be discarded, or they are flushed to the stable log 48 * (also in the pool) due to a fsync, O_DSYNC or other synchronous 49 * requirement. In the event of a panic or power fail then those log 50 * records (transactions) are replayed. 51 * 52 * There is one ZIL per file system. Its on-disk (pool) format consists 53 * of 3 parts: 54 * 55 * - ZIL header 56 * - ZIL blocks 57 * - ZIL records 58 * 59 * A log record holds a system call transaction. Log blocks can 60 * hold many log records and the blocks are chained together. 61 * Each ZIL block contains a block pointer (blkptr_t) to the next 62 * ZIL block in the chain. The ZIL header points to the first 63 * block in the chain. Note there is not a fixed place in the pool 64 * to hold blocks. They are dynamically allocated and freed as 65 * needed from the blocks available. Figure X shows the ZIL structure: 66 */ 67 68/* 69 * Disable intent logging replay. This global ZIL switch affects all pools. 70 */ 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 = BP_IDENTITY(bp); 153 zil_bp_node_t *zn; 154 avl_index_t where; 155 156 if (avl_find(t, dva, &where) != NULL) 157 return (SET_ERROR(EEXIST)); 158 159 zn = kmem_alloc(sizeof (zil_bp_node_t), KM_SLEEP); 160 zn->zn_dva = *dva; 161 avl_insert(t, zn, where); 162 163 return (0); 164} 165 166static zil_header_t * 167zil_header_in_syncing_context(zilog_t *zilog) 168{ 169 return ((zil_header_t *)zilog->zl_header); 170} 171 172static void 173zil_init_log_chain(zilog_t *zilog, blkptr_t *bp) 174{ 175 zio_cksum_t *zc = &bp->blk_cksum; 176 177 zc->zc_word[ZIL_ZC_GUID_0] = spa_get_random(-1ULL); 178 zc->zc_word[ZIL_ZC_GUID_1] = spa_get_random(-1ULL); 179 zc->zc_word[ZIL_ZC_OBJSET] = dmu_objset_id(zilog->zl_os); 180 zc->zc_word[ZIL_ZC_SEQ] = 1ULL; 181} 182 183/* 184 * Read a log block and make sure it's valid. 185 */ 186static int 187zil_read_log_block(zilog_t *zilog, const blkptr_t *bp, blkptr_t *nbp, void *dst, 188 char **end) 189{ 190 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL; 191 uint32_t aflags = ARC_WAIT; 192 arc_buf_t *abuf = NULL; 193 zbookmark_t zb; 194 int error; 195 196 if (zilog->zl_header->zh_claim_txg == 0) 197 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; 198 199 if (!(zilog->zl_header->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) 200 zio_flags |= ZIO_FLAG_SPECULATIVE; 201 202 SET_BOOKMARK(&zb, bp->blk_cksum.zc_word[ZIL_ZC_OBJSET], 203 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]); 204 205 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf, 206 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); 207 208 if (error == 0) { 209 zio_cksum_t cksum = bp->blk_cksum; 210 211 /* 212 * Validate the checksummed log block. 213 * 214 * Sequence numbers should be... sequential. The checksum 215 * verifier for the next block should be bp's checksum plus 1. 216 * 217 * Also check the log chain linkage and size used. 218 */ 219 cksum.zc_word[ZIL_ZC_SEQ]++; 220 221 if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) { 222 zil_chain_t *zilc = abuf->b_data; 223 char *lr = (char *)(zilc + 1); 224 uint64_t len = zilc->zc_nused - sizeof (zil_chain_t); 225 226 if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum, 227 sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk)) { 228 error = SET_ERROR(ECKSUM); 229 } else { 230 bcopy(lr, dst, len); 231 *end = (char *)dst + len; 232 *nbp = zilc->zc_next_blk; 233 } 234 } else { 235 char *lr = abuf->b_data; 236 uint64_t size = BP_GET_LSIZE(bp); 237 zil_chain_t *zilc = (zil_chain_t *)(lr + size) - 1; 238 239 if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum, 240 sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk) || 241 (zilc->zc_nused > (size - sizeof (*zilc)))) { 242 error = SET_ERROR(ECKSUM); 243 } else { 244 bcopy(lr, dst, zilc->zc_nused); 245 *end = (char *)dst + zilc->zc_nused; 246 *nbp = zilc->zc_next_blk; 247 } 248 } 249 250 VERIFY(arc_buf_remove_ref(abuf, &abuf)); 251 } 252 253 return (error); 254} 255 256/* 257 * Read a TX_WRITE log data block. 258 */ 259static int 260zil_read_log_data(zilog_t *zilog, const lr_write_t *lr, void *wbuf) 261{ 262 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL; 263 const blkptr_t *bp = &lr->lr_blkptr; 264 uint32_t aflags = ARC_WAIT; 265 arc_buf_t *abuf = NULL; 266 zbookmark_t zb; 267 int error; 268 269 if (BP_IS_HOLE(bp)) { 270 if (wbuf != NULL) 271 bzero(wbuf, MAX(BP_GET_LSIZE(bp), lr->lr_length)); 272 return (0); 273 } 274 275 if (zilog->zl_header->zh_claim_txg == 0) 276 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; 277 278 SET_BOOKMARK(&zb, dmu_objset_id(zilog->zl_os), lr->lr_foid, 279 ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp)); 280 281 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf, 282 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); 283 284 if (error == 0) { 285 if (wbuf != NULL) 286 bcopy(abuf->b_data, wbuf, arc_buf_size(abuf)); 287 (void) arc_buf_remove_ref(abuf, &abuf); 288 } 289 290 return (error); 291} 292 293/* 294 * Parse the intent log, and call parse_func for each valid record within. 295 */ 296int 297zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func, 298 zil_parse_lr_func_t *parse_lr_func, void *arg, uint64_t txg) 299{ 300 const zil_header_t *zh = zilog->zl_header; 301 boolean_t claimed = !!zh->zh_claim_txg; 302 uint64_t claim_blk_seq = claimed ? zh->zh_claim_blk_seq : UINT64_MAX; 303 uint64_t claim_lr_seq = claimed ? zh->zh_claim_lr_seq : UINT64_MAX; 304 uint64_t max_blk_seq = 0; 305 uint64_t max_lr_seq = 0; 306 uint64_t blk_count = 0; 307 uint64_t lr_count = 0; 308 blkptr_t blk, next_blk; 309 char *lrbuf, *lrp; 310 int error = 0; 311 312 /* 313 * Old logs didn't record the maximum zh_claim_lr_seq. 314 */ 315 if (!(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) 316 claim_lr_seq = UINT64_MAX; 317 318 /* 319 * Starting at the block pointed to by zh_log we read the log chain. 320 * For each block in the chain we strongly check that block to 321 * ensure its validity. We stop when an invalid block is found. 322 * For each block pointer in the chain we call parse_blk_func(). 323 * For each record in each valid block we call parse_lr_func(). 324 * If the log has been claimed, stop if we encounter a sequence 325 * number greater than the highest claimed sequence number. 326 */ 327 lrbuf = zio_buf_alloc(SPA_MAXBLOCKSIZE); 328 zil_bp_tree_init(zilog); 329 330 for (blk = zh->zh_log; !BP_IS_HOLE(&blk); blk = next_blk) { 331 uint64_t blk_seq = blk.blk_cksum.zc_word[ZIL_ZC_SEQ]; 332 int reclen; 333 char *end; 334 335 if (blk_seq > claim_blk_seq) 336 break; 337 if ((error = parse_blk_func(zilog, &blk, arg, txg)) != 0) 338 break; 339 ASSERT3U(max_blk_seq, <, blk_seq); 340 max_blk_seq = blk_seq; 341 blk_count++; 342 343 if (max_lr_seq == claim_lr_seq && max_blk_seq == claim_blk_seq) 344 break; 345 346 error = zil_read_log_block(zilog, &blk, &next_blk, lrbuf, &end); 347 if (error != 0) 348 break; 349 350 for (lrp = lrbuf; lrp < end; lrp += reclen) { 351 lr_t *lr = (lr_t *)lrp; 352 reclen = lr->lrc_reclen; 353 ASSERT3U(reclen, >=, sizeof (lr_t)); 354 if (lr->lrc_seq > claim_lr_seq) 355 goto done; 356 if ((error = parse_lr_func(zilog, lr, arg, txg)) != 0) 357 goto done; 358 ASSERT3U(max_lr_seq, <, lr->lrc_seq); 359 max_lr_seq = lr->lrc_seq; 360 lr_count++; 361 } 362 } 363done: 364 zilog->zl_parse_error = error; 365 zilog->zl_parse_blk_seq = max_blk_seq; 366 zilog->zl_parse_lr_seq = max_lr_seq; 367 zilog->zl_parse_blk_count = blk_count; 368 zilog->zl_parse_lr_count = lr_count; 369 370 ASSERT(!claimed || !(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID) || 371 (max_blk_seq == claim_blk_seq && max_lr_seq == claim_lr_seq)); 372 373 zil_bp_tree_fini(zilog); 374 zio_buf_free(lrbuf, SPA_MAXBLOCKSIZE); 375 376 return (error); 377} 378 379static int 380zil_claim_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t first_txg) 381{ 382 /* 383 * Claim log block if not already committed and not already claimed. 384 * If tx == NULL, just verify that the block is claimable. 385 */ 386 if (BP_IS_HOLE(bp) || bp->blk_birth < first_txg || 387 zil_bp_tree_add(zilog, bp) != 0) 388 return (0); 389 390 return (zio_wait(zio_claim(NULL, zilog->zl_spa, 391 tx == NULL ? 0 : first_txg, bp, spa_claim_notify, NULL, 392 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB))); 393} 394 395static int 396zil_claim_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t first_txg) 397{ 398 lr_write_t *lr = (lr_write_t *)lrc; 399 int error; 400 401 if (lrc->lrc_txtype != TX_WRITE) 402 return (0); 403 404 /* 405 * If the block is not readable, don't claim it. This can happen 406 * in normal operation when a log block is written to disk before 407 * some of the dmu_sync() blocks it points to. In this case, the 408 * transaction cannot have been committed to anyone (we would have 409 * waited for all writes to be stable first), so it is semantically 410 * correct to declare this the end of the log. 411 */ 412 if (lr->lr_blkptr.blk_birth >= first_txg && 413 (error = zil_read_log_data(zilog, lr, NULL)) != 0) 414 return (error); 415 return (zil_claim_log_block(zilog, &lr->lr_blkptr, tx, first_txg)); 416} 417 418/* ARGSUSED */ 419static int 420zil_free_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t claim_txg) 421{ 422 zio_free_zil(zilog->zl_spa, dmu_tx_get_txg(tx), bp); 423 424 return (0); 425} 426 427static int 428zil_free_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t claim_txg) 429{ 430 lr_write_t *lr = (lr_write_t *)lrc; 431 blkptr_t *bp = &lr->lr_blkptr; 432 433 /* 434 * If we previously claimed it, we need to free it. 435 */ 436 if (claim_txg != 0 && lrc->lrc_txtype == TX_WRITE && 437 bp->blk_birth >= claim_txg && zil_bp_tree_add(zilog, bp) == 0 && 438 !BP_IS_HOLE(bp)) 439 zio_free(zilog->zl_spa, dmu_tx_get_txg(tx), bp); 440 441 return (0); 442} 443 444static lwb_t * 445zil_alloc_lwb(zilog_t *zilog, blkptr_t *bp, uint64_t txg) 446{ 447 lwb_t *lwb; 448 449 lwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP); 450 lwb->lwb_zilog = zilog; 451 lwb->lwb_blk = *bp; 452 lwb->lwb_buf = zio_buf_alloc(BP_GET_LSIZE(bp)); 453 lwb->lwb_max_txg = txg; 454 lwb->lwb_zio = NULL; 455 lwb->lwb_tx = NULL; 456 if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) { 457 lwb->lwb_nused = sizeof (zil_chain_t); 458 lwb->lwb_sz = BP_GET_LSIZE(bp); 459 } else { 460 lwb->lwb_nused = 0; 461 lwb->lwb_sz = BP_GET_LSIZE(bp) - sizeof (zil_chain_t); 462 } 463 464 mutex_enter(&zilog->zl_lock); 465 list_insert_tail(&zilog->zl_lwb_list, lwb); 466 mutex_exit(&zilog->zl_lock); 467 468 return (lwb); 469} 470 471/* 472 * Called when we create in-memory log transactions so that we know 473 * to cleanup the itxs at the end of spa_sync(). 474 */ 475void 476zilog_dirty(zilog_t *zilog, uint64_t txg) 477{ 478 dsl_pool_t *dp = zilog->zl_dmu_pool; 479 dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os); 480 481 if (dsl_dataset_is_snapshot(ds)) 482 panic("dirtying snapshot!"); 483 484 if (txg_list_add(&dp->dp_dirty_zilogs, zilog, txg)) { 485 /* up the hold count until we can be written out */ 486 dmu_buf_add_ref(ds->ds_dbuf, zilog); 487 } 488} 489 490boolean_t 491zilog_is_dirty(zilog_t *zilog) 492{ 493 dsl_pool_t *dp = zilog->zl_dmu_pool; 494 495 for (int t = 0; t < TXG_SIZE; t++) { 496 if (txg_list_member(&dp->dp_dirty_zilogs, zilog, t)) 497 return (B_TRUE); 498 } 499 return (B_FALSE); 500} 501 502/* 503 * Create an on-disk intent log. 504 */ 505static lwb_t * 506zil_create(zilog_t *zilog) 507{ 508 const zil_header_t *zh = zilog->zl_header; 509 lwb_t *lwb = NULL; 510 uint64_t txg = 0; 511 dmu_tx_t *tx = NULL; 512 blkptr_t blk; 513 int error = 0; 514 515 /* 516 * Wait for any previous destroy to complete. 517 */ 518 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 519 520 ASSERT(zh->zh_claim_txg == 0); 521 ASSERT(zh->zh_replay_seq == 0); 522 523 blk = zh->zh_log; 524 525 /* 526 * Allocate an initial log block if: 527 * - there isn't one already 528 * - the existing block is the wrong endianess 529 */ 530 if (BP_IS_HOLE(&blk) || BP_SHOULD_BYTESWAP(&blk)) { 531 tx = dmu_tx_create(zilog->zl_os); 532 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 533 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 534 txg = dmu_tx_get_txg(tx); 535 536 if (!BP_IS_HOLE(&blk)) { 537 zio_free_zil(zilog->zl_spa, txg, &blk); 538 BP_ZERO(&blk); 539 } 540 541 error = zio_alloc_zil(zilog->zl_spa, txg, &blk, NULL, 542 ZIL_MIN_BLKSZ, zilog->zl_logbias == ZFS_LOGBIAS_LATENCY); 543 544 if (error == 0) 545 zil_init_log_chain(zilog, &blk); 546 } 547 548 /* 549 * Allocate a log write buffer (lwb) for the first log block. 550 */ 551 if (error == 0) 552 lwb = zil_alloc_lwb(zilog, &blk, txg); 553 554 /* 555 * If we just allocated the first log block, commit our transaction 556 * and wait for zil_sync() to stuff the block poiner into zh_log. 557 * (zh is part of the MOS, so we cannot modify it in open context.) 558 */ 559 if (tx != NULL) { 560 dmu_tx_commit(tx); 561 txg_wait_synced(zilog->zl_dmu_pool, txg); 562 } 563 564 ASSERT(bcmp(&blk, &zh->zh_log, sizeof (blk)) == 0); 565 566 return (lwb); 567} 568 569/* 570 * In one tx, free all log blocks and clear the log header. 571 * If keep_first is set, then we're replaying a log with no content. 572 * We want to keep the first block, however, so that the first 573 * synchronous transaction doesn't require a txg_wait_synced() 574 * in zil_create(). We don't need to txg_wait_synced() here either 575 * when keep_first is set, because both zil_create() and zil_destroy() 576 * will wait for any in-progress destroys to complete. 577 */ 578void 579zil_destroy(zilog_t *zilog, boolean_t keep_first) 580{ 581 const zil_header_t *zh = zilog->zl_header; 582 lwb_t *lwb; 583 dmu_tx_t *tx; 584 uint64_t txg; 585 586 /* 587 * Wait for any previous destroy to complete. 588 */ 589 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 590 591 zilog->zl_old_header = *zh; /* debugging aid */ 592 593 if (BP_IS_HOLE(&zh->zh_log)) 594 return; 595 596 tx = dmu_tx_create(zilog->zl_os); 597 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 598 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 599 txg = dmu_tx_get_txg(tx); 600 601 mutex_enter(&zilog->zl_lock); 602 603 ASSERT3U(zilog->zl_destroy_txg, <, txg); 604 zilog->zl_destroy_txg = txg; 605 zilog->zl_keep_first = keep_first; 606 607 if (!list_is_empty(&zilog->zl_lwb_list)) { 608 ASSERT(zh->zh_claim_txg == 0); 609 VERIFY(!keep_first); 610 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { 611 list_remove(&zilog->zl_lwb_list, lwb); 612 if (lwb->lwb_buf != NULL) 613 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 614 zio_free_zil(zilog->zl_spa, txg, &lwb->lwb_blk); 615 kmem_cache_free(zil_lwb_cache, lwb); 616 } 617 } else if (!keep_first) { 618 zil_destroy_sync(zilog, tx); 619 } 620 mutex_exit(&zilog->zl_lock); 621 622 dmu_tx_commit(tx); 623} 624 625void 626zil_destroy_sync(zilog_t *zilog, dmu_tx_t *tx) 627{ 628 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 629 (void) zil_parse(zilog, zil_free_log_block, 630 zil_free_log_record, tx, zilog->zl_header->zh_claim_txg); 631} 632 633int 634zil_claim(const char *osname, void *txarg) 635{ 636 dmu_tx_t *tx = txarg; 637 uint64_t first_txg = dmu_tx_get_txg(tx); 638 zilog_t *zilog; 639 zil_header_t *zh; 640 objset_t *os; 641 int error; 642 643 error = dmu_objset_own(osname, DMU_OST_ANY, B_FALSE, FTAG, &os); 644 if (error != 0) { 645 cmn_err(CE_WARN, "can't open objset for %s", osname); 646 return (0); 647 } 648 649 zilog = dmu_objset_zil(os); 650 zh = zil_header_in_syncing_context(zilog); 651 652 if (spa_get_log_state(zilog->zl_spa) == SPA_LOG_CLEAR) { 653 if (!BP_IS_HOLE(&zh->zh_log)) 654 zio_free_zil(zilog->zl_spa, first_txg, &zh->zh_log); 655 BP_ZERO(&zh->zh_log); 656 dsl_dataset_dirty(dmu_objset_ds(os), tx); 657 dmu_objset_disown(os, FTAG); 658 return (0); 659 } 660 661 /* 662 * Claim all log blocks if we haven't already done so, and remember 663 * the highest claimed sequence number. This ensures that if we can 664 * read only part of the log now (e.g. due to a missing device), 665 * but we can read the entire log later, we will not try to replay 666 * or destroy beyond the last block we successfully claimed. 667 */ 668 ASSERT3U(zh->zh_claim_txg, <=, first_txg); 669 if (zh->zh_claim_txg == 0 && !BP_IS_HOLE(&zh->zh_log)) { 670 (void) zil_parse(zilog, zil_claim_log_block, 671 zil_claim_log_record, tx, first_txg); 672 zh->zh_claim_txg = first_txg; 673 zh->zh_claim_blk_seq = zilog->zl_parse_blk_seq; 674 zh->zh_claim_lr_seq = zilog->zl_parse_lr_seq; 675 if (zilog->zl_parse_lr_count || zilog->zl_parse_blk_count > 1) 676 zh->zh_flags |= ZIL_REPLAY_NEEDED; 677 zh->zh_flags |= ZIL_CLAIM_LR_SEQ_VALID; 678 dsl_dataset_dirty(dmu_objset_ds(os), tx); 679 } 680 681 ASSERT3U(first_txg, ==, (spa_last_synced_txg(zilog->zl_spa) + 1)); 682 dmu_objset_disown(os, FTAG); 683 return (0); 684} 685 686/* 687 * Check the log by walking the log chain. 688 * Checksum errors are ok as they indicate the end of the chain. 689 * Any other error (no device or read failure) returns an error. 690 */ 691int 692zil_check_log_chain(const char *osname, void *tx) 693{ 694 zilog_t *zilog; 695 objset_t *os; 696 blkptr_t *bp; 697 int error; 698 699 ASSERT(tx == NULL); 700 701 error = dmu_objset_hold(osname, FTAG, &os); 702 if (error != 0) { 703 cmn_err(CE_WARN, "can't open objset for %s", osname); 704 return (0); 705 } 706 707 zilog = dmu_objset_zil(os); 708 bp = (blkptr_t *)&zilog->zl_header->zh_log; 709 710 /* 711 * Check the first block and determine if it's on a log device 712 * which may have been removed or faulted prior to loading this 713 * pool. If so, there's no point in checking the rest of the log 714 * as its content should have already been synced to the pool. 715 */ 716 if (!BP_IS_HOLE(bp)) { 717 vdev_t *vd; 718 boolean_t valid = B_TRUE; 719 720 spa_config_enter(os->os_spa, SCL_STATE, FTAG, RW_READER); 721 vd = vdev_lookup_top(os->os_spa, DVA_GET_VDEV(&bp->blk_dva[0])); 722 if (vd->vdev_islog && vdev_is_dead(vd)) 723 valid = vdev_log_state_valid(vd); 724 spa_config_exit(os->os_spa, SCL_STATE, FTAG); 725 726 if (!valid) { 727 dmu_objset_rele(os, FTAG); 728 return (0); 729 } 730 } 731 732 /* 733 * Because tx == NULL, zil_claim_log_block() will not actually claim 734 * any blocks, but just determine whether it is possible to do so. 735 * In addition to checking the log chain, zil_claim_log_block() 736 * will invoke zio_claim() with a done func of spa_claim_notify(), 737 * which will update spa_max_claim_txg. See spa_load() for details. 738 */ 739 error = zil_parse(zilog, zil_claim_log_block, zil_claim_log_record, tx, 740 zilog->zl_header->zh_claim_txg ? -1ULL : spa_first_txg(os->os_spa)); 741 742 dmu_objset_rele(os, FTAG); 743 744 return ((error == ECKSUM || error == ENOENT) ? 0 : error); 745} 746 747static int 748zil_vdev_compare(const void *x1, const void *x2) 749{ 750 const uint64_t v1 = ((zil_vdev_node_t *)x1)->zv_vdev; 751 const uint64_t v2 = ((zil_vdev_node_t *)x2)->zv_vdev; 752 753 if (v1 < v2) 754 return (-1); 755 if (v1 > v2) 756 return (1); 757 758 return (0); 759} 760 761void 762zil_add_block(zilog_t *zilog, const blkptr_t *bp) 763{ 764 avl_tree_t *t = &zilog->zl_vdev_tree; 765 avl_index_t where; 766 zil_vdev_node_t *zv, zvsearch; 767 int ndvas = BP_GET_NDVAS(bp); 768 int i; 769 770 if (zfs_nocacheflush) 771 return; 772 773 ASSERT(zilog->zl_writer); 774 775 /* 776 * Even though we're zl_writer, we still need a lock because the 777 * zl_get_data() callbacks may have dmu_sync() done callbacks 778 * that will run concurrently. 779 */ 780 mutex_enter(&zilog->zl_vdev_lock); 781 for (i = 0; i < ndvas; i++) { 782 zvsearch.zv_vdev = DVA_GET_VDEV(&bp->blk_dva[i]); 783 if (avl_find(t, &zvsearch, &where) == NULL) { 784 zv = kmem_alloc(sizeof (*zv), KM_SLEEP); 785 zv->zv_vdev = zvsearch.zv_vdev; 786 avl_insert(t, zv, where); 787 } 788 } 789 mutex_exit(&zilog->zl_vdev_lock); 790} 791 792static void 793zil_flush_vdevs(zilog_t *zilog) 794{ 795 spa_t *spa = zilog->zl_spa; 796 avl_tree_t *t = &zilog->zl_vdev_tree; 797 void *cookie = NULL; 798 zil_vdev_node_t *zv; 799 zio_t *zio; 800 801 ASSERT(zilog->zl_writer); 802 803 /* 804 * We don't need zl_vdev_lock here because we're the zl_writer, 805 * and all zl_get_data() callbacks are done. 806 */ 807 if (avl_numnodes(t) == 0) 808 return; 809 810 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER); 811 812 zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL); 813 814 while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) { 815 vdev_t *vd = vdev_lookup_top(spa, zv->zv_vdev); 816 if (vd != NULL) 817 zio_flush(zio, vd); 818 kmem_free(zv, sizeof (*zv)); 819 } 820 821 /* 822 * Wait for all the flushes to complete. Not all devices actually 823 * support the DKIOCFLUSHWRITECACHE ioctl, so it's OK if it fails. 824 */ 825 (void) zio_wait(zio); 826 827 spa_config_exit(spa, SCL_STATE, FTAG); 828} 829 830/* 831 * Function called when a log block write completes 832 */ 833static void 834zil_lwb_write_done(zio_t *zio) 835{ 836 lwb_t *lwb = zio->io_private; 837 zilog_t *zilog = lwb->lwb_zilog; 838 dmu_tx_t *tx = lwb->lwb_tx; 839 840 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 841 ASSERT(BP_GET_TYPE(zio->io_bp) == DMU_OT_INTENT_LOG); 842 ASSERT(BP_GET_LEVEL(zio->io_bp) == 0); 843 ASSERT(BP_GET_BYTEORDER(zio->io_bp) == ZFS_HOST_BYTEORDER); 844 ASSERT(!BP_IS_GANG(zio->io_bp)); 845 ASSERT(!BP_IS_HOLE(zio->io_bp)); 846 ASSERT(zio->io_bp->blk_fill == 0); 847 848 /* 849 * Ensure the lwb buffer pointer is cleared before releasing 850 * the txg. If we have had an allocation failure and 851 * the txg is waiting to sync then we want want zil_sync() 852 * to remove the lwb so that it's not picked up as the next new 853 * one in zil_commit_writer(). zil_sync() will only remove 854 * the lwb if lwb_buf is null. 855 */ 856 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 857 mutex_enter(&zilog->zl_lock); 858 lwb->lwb_buf = NULL; 859 lwb->lwb_tx = NULL; 860 mutex_exit(&zilog->zl_lock); 861 862 /* 863 * Now that we've written this log block, we have a stable pointer 864 * to the next block in the chain, so it's OK to let the txg in 865 * which we allocated the next block sync. 866 */ 867 dmu_tx_commit(tx); 868} 869 870/* 871 * Initialize the io for a log block. 872 */ 873static void 874zil_lwb_write_init(zilog_t *zilog, lwb_t *lwb) 875{ 876 zbookmark_t zb; 877 878 SET_BOOKMARK(&zb, lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_OBJSET], 879 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, 880 lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_SEQ]); 881 882 if (zilog->zl_root_zio == NULL) { 883 zilog->zl_root_zio = zio_root(zilog->zl_spa, NULL, NULL, 884 ZIO_FLAG_CANFAIL); 885 } 886 if (lwb->lwb_zio == NULL) { 887 lwb->lwb_zio = zio_rewrite(zilog->zl_root_zio, zilog->zl_spa, 888 0, &lwb->lwb_blk, lwb->lwb_buf, BP_GET_LSIZE(&lwb->lwb_blk), 889 zil_lwb_write_done, lwb, ZIO_PRIORITY_SYNC_WRITE, 890 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE, &zb); 891 } 892} 893 894/* 895 * Define a limited set of intent log block sizes. 896 * 897 * These must be a multiple of 4KB. Note only the amount used (again 898 * aligned to 4KB) actually gets written. However, we can't always just 899 * allocate SPA_MAXBLOCKSIZE as the slog space could be exhausted. 900 */ 901uint64_t zil_block_buckets[] = { 902 4096, /* non TX_WRITE */ 903 8192+4096, /* data base */ 904 32*1024 + 4096, /* NFS writes */ 905 UINT64_MAX 906}; 907 908/* 909 * Use the slog as long as the logbias is 'latency' and the current commit size 910 * is less than the limit or the total list size is less than 2X the limit. 911 * Limit checking is disabled by setting zil_slog_limit to UINT64_MAX. 912 */ 913uint64_t zil_slog_limit = 1024 * 1024; 914#define USE_SLOG(zilog) (((zilog)->zl_logbias == ZFS_LOGBIAS_LATENCY) && \ 915 (((zilog)->zl_cur_used < zil_slog_limit) || \ 916 ((zilog)->zl_itx_list_sz < (zil_slog_limit << 1)))) 917 918/* 919 * Start a log block write and advance to the next log block. 920 * Calls are serialized. 921 */ 922static lwb_t * 923zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb) 924{ 925 lwb_t *nlwb = NULL; 926 zil_chain_t *zilc; 927 spa_t *spa = zilog->zl_spa; 928 blkptr_t *bp; 929 dmu_tx_t *tx; 930 uint64_t txg; 931 uint64_t zil_blksz, wsz; 932 int i, error; 933 934 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) { 935 zilc = (zil_chain_t *)lwb->lwb_buf; 936 bp = &zilc->zc_next_blk; 937 } else { 938 zilc = (zil_chain_t *)(lwb->lwb_buf + lwb->lwb_sz); 939 bp = &zilc->zc_next_blk; 940 } 941 942 ASSERT(lwb->lwb_nused <= lwb->lwb_sz); 943 944 /* 945 * Allocate the next block and save its address in this block 946 * before writing it in order to establish the log chain. 947 * Note that if the allocation of nlwb synced before we wrote 948 * the block that points at it (lwb), we'd leak it if we crashed. 949 * Therefore, we don't do dmu_tx_commit() until zil_lwb_write_done(). 950 * We dirty the dataset to ensure that zil_sync() will be called 951 * to clean up in the event of allocation failure or I/O failure. 952 */ 953 tx = dmu_tx_create(zilog->zl_os); 954 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 955 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 956 txg = dmu_tx_get_txg(tx); 957 958 lwb->lwb_tx = tx; 959 960 /* 961 * Log blocks are pre-allocated. Here we select the size of the next 962 * block, based on size used in the last block. 963 * - first find the smallest bucket that will fit the block from a 964 * limited set of block sizes. This is because it's faster to write 965 * blocks allocated from the same metaslab as they are adjacent or 966 * close. 967 * - next find the maximum from the new suggested size and an array of 968 * previous sizes. This lessens a picket fence effect of wrongly 969 * guesssing the size if we have a stream of say 2k, 64k, 2k, 64k 970 * requests. 971 * 972 * Note we only write what is used, but we can't just allocate 973 * the maximum block size because we can exhaust the available 974 * pool log space. 975 */ 976 zil_blksz = zilog->zl_cur_used + sizeof (zil_chain_t); 977 for (i = 0; zil_blksz > zil_block_buckets[i]; i++) 978 continue; 979 zil_blksz = zil_block_buckets[i]; 980 if (zil_blksz == UINT64_MAX) 981 zil_blksz = SPA_MAXBLOCKSIZE; 982 zilog->zl_prev_blks[zilog->zl_prev_rotor] = zil_blksz; 983 for (i = 0; i < ZIL_PREV_BLKS; i++) 984 zil_blksz = MAX(zil_blksz, zilog->zl_prev_blks[i]); 985 zilog->zl_prev_rotor = (zilog->zl_prev_rotor + 1) & (ZIL_PREV_BLKS - 1); 986 987 BP_ZERO(bp); 988 /* pass the old blkptr in order to spread log blocks across devs */ 989 error = zio_alloc_zil(spa, txg, bp, &lwb->lwb_blk, zil_blksz, 990 USE_SLOG(zilog)); 991 if (error == 0) { 992 ASSERT3U(bp->blk_birth, ==, txg); 993 bp->blk_cksum = lwb->lwb_blk.blk_cksum; 994 bp->blk_cksum.zc_word[ZIL_ZC_SEQ]++; 995 996 /* 997 * Allocate a new log write buffer (lwb). 998 */ 999 nlwb = zil_alloc_lwb(zilog, bp, txg); 1000 1001 /* Record the block for later vdev flushing */ 1002 zil_add_block(zilog, &lwb->lwb_blk); 1003 } 1004 1005 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) { 1006 /* For Slim ZIL only write what is used. */ 1007 wsz = P2ROUNDUP_TYPED(lwb->lwb_nused, ZIL_MIN_BLKSZ, uint64_t); 1008 ASSERT3U(wsz, <=, lwb->lwb_sz); 1009 zio_shrink(lwb->lwb_zio, wsz); 1010 1011 } else { 1012 wsz = lwb->lwb_sz; 1013 } 1014 1015 zilc->zc_pad = 0; 1016 zilc->zc_nused = lwb->lwb_nused; 1017 zilc->zc_eck.zec_cksum = lwb->lwb_blk.blk_cksum; 1018 1019 /* 1020 * clear unused data for security 1021 */ 1022 bzero(lwb->lwb_buf + lwb->lwb_nused, wsz - lwb->lwb_nused); 1023 1024 zio_nowait(lwb->lwb_zio); /* Kick off the write for the old log block */ 1025 1026 /* 1027 * If there was an allocation failure then nlwb will be null which 1028 * forces a txg_wait_synced(). 1029 */ 1030 return (nlwb); 1031} 1032 1033static lwb_t * 1034zil_lwb_commit(zilog_t *zilog, itx_t *itx, lwb_t *lwb) 1035{ 1036 lr_t *lrc = &itx->itx_lr; /* common log record */ 1037 lr_write_t *lrw = (lr_write_t *)lrc; 1038 char *lr_buf; 1039 uint64_t txg = lrc->lrc_txg; 1040 uint64_t reclen = lrc->lrc_reclen; 1041 uint64_t dlen = 0; 1042 1043 if (lwb == NULL) 1044 return (NULL); 1045 1046 ASSERT(lwb->lwb_buf != NULL); 1047 ASSERT(zilog_is_dirty(zilog) || 1048 spa_freeze_txg(zilog->zl_spa) != UINT64_MAX); 1049 1050 if (lrc->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY) 1051 dlen = P2ROUNDUP_TYPED( 1052 lrw->lr_length, sizeof (uint64_t), uint64_t); 1053 1054 zilog->zl_cur_used += (reclen + dlen); 1055 1056 zil_lwb_write_init(zilog, lwb); 1057 1058 /* 1059 * If this record won't fit in the current log block, start a new one. 1060 */ 1061 if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) { 1062 lwb = zil_lwb_write_start(zilog, lwb); 1063 if (lwb == NULL) 1064 return (NULL); 1065 zil_lwb_write_init(zilog, lwb); 1066 ASSERT(LWB_EMPTY(lwb)); 1067 if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) { 1068 txg_wait_synced(zilog->zl_dmu_pool, txg); 1069 return (lwb); 1070 } 1071 } 1072 1073 lr_buf = lwb->lwb_buf + lwb->lwb_nused; 1074 bcopy(lrc, lr_buf, reclen); 1075 lrc = (lr_t *)lr_buf; 1076 lrw = (lr_write_t *)lrc; 1077 1078 /* 1079 * If it's a write, fetch the data or get its blkptr as appropriate. 1080 */ 1081 if (lrc->lrc_txtype == TX_WRITE) { 1082 if (txg > spa_freeze_txg(zilog->zl_spa)) 1083 txg_wait_synced(zilog->zl_dmu_pool, txg); 1084 if (itx->itx_wr_state != WR_COPIED) { 1085 char *dbuf; 1086 int error; 1087 1088 if (dlen) { 1089 ASSERT(itx->itx_wr_state == WR_NEED_COPY); 1090 dbuf = lr_buf + reclen; 1091 lrw->lr_common.lrc_reclen += dlen; 1092 } else { 1093 ASSERT(itx->itx_wr_state == WR_INDIRECT); 1094 dbuf = NULL; 1095 } 1096 error = zilog->zl_get_data( 1097 itx->itx_private, lrw, dbuf, lwb->lwb_zio); 1098 if (error == EIO) { 1099 txg_wait_synced(zilog->zl_dmu_pool, txg); 1100 return (lwb); 1101 } 1102 if (error != 0) { 1103 ASSERT(error == ENOENT || error == EEXIST || 1104 error == EALREADY); 1105 return (lwb); 1106 } 1107 } 1108 } 1109 1110 /* 1111 * We're actually making an entry, so update lrc_seq to be the 1112 * log record sequence number. Note that this is generally not 1113 * equal to the itx sequence number because not all transactions 1114 * are synchronous, and sometimes spa_sync() gets there first. 1115 */ 1116 lrc->lrc_seq = ++zilog->zl_lr_seq; /* we are single threaded */ 1117 lwb->lwb_nused += reclen + dlen; 1118 lwb->lwb_max_txg = MAX(lwb->lwb_max_txg, txg); 1119 ASSERT3U(lwb->lwb_nused, <=, lwb->lwb_sz); 1120 ASSERT0(P2PHASE(lwb->lwb_nused, sizeof (uint64_t))); 1121 1122 return (lwb); 1123} 1124 1125itx_t * 1126zil_itx_create(uint64_t txtype, size_t lrsize) 1127{ 1128 itx_t *itx; 1129 1130 lrsize = P2ROUNDUP_TYPED(lrsize, sizeof (uint64_t), size_t); 1131 1132 itx = kmem_alloc(offsetof(itx_t, itx_lr) + lrsize, KM_SLEEP); 1133 itx->itx_lr.lrc_txtype = txtype; 1134 itx->itx_lr.lrc_reclen = lrsize; 1135 itx->itx_sod = lrsize; /* if write & WR_NEED_COPY will be increased */ 1136 itx->itx_lr.lrc_seq = 0; /* defensive */ 1137 itx->itx_sync = B_TRUE; /* default is synchronous */ 1138 1139 return (itx); 1140} 1141 1142void 1143zil_itx_destroy(itx_t *itx) 1144{ 1145 kmem_free(itx, offsetof(itx_t, itx_lr) + itx->itx_lr.lrc_reclen); 1146} 1147 1148/* 1149 * Free up the sync and async itxs. The itxs_t has already been detached 1150 * so no locks are needed. 1151 */ 1152static void 1153zil_itxg_clean(itxs_t *itxs) 1154{ 1155 itx_t *itx; 1156 list_t *list; 1157 avl_tree_t *t; 1158 void *cookie; 1159 itx_async_node_t *ian; 1160 1161 list = &itxs->i_sync_list; 1162 while ((itx = list_head(list)) != NULL) { 1163 list_remove(list, itx); 1164 kmem_free(itx, offsetof(itx_t, itx_lr) + 1165 itx->itx_lr.lrc_reclen); 1166 } 1167 1168 cookie = NULL; 1169 t = &itxs->i_async_tree; 1170 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) { 1171 list = &ian->ia_list; 1172 while ((itx = list_head(list)) != NULL) { 1173 list_remove(list, itx); 1174 kmem_free(itx, offsetof(itx_t, itx_lr) + 1175 itx->itx_lr.lrc_reclen); 1176 } 1177 list_destroy(list); 1178 kmem_free(ian, sizeof (itx_async_node_t)); 1179 } 1180 avl_destroy(t); 1181 1182 kmem_free(itxs, sizeof (itxs_t)); 1183} 1184 1185static int 1186zil_aitx_compare(const void *x1, const void *x2) 1187{ 1188 const uint64_t o1 = ((itx_async_node_t *)x1)->ia_foid; 1189 const uint64_t o2 = ((itx_async_node_t *)x2)->ia_foid; 1190 1191 if (o1 < o2) 1192 return (-1); 1193 if (o1 > o2) 1194 return (1); 1195 1196 return (0); 1197} 1198 1199/* 1200 * Remove all async itx with the given oid. 1201 */ 1202static void 1203zil_remove_async(zilog_t *zilog, uint64_t oid) 1204{ 1205 uint64_t otxg, txg; 1206 itx_async_node_t *ian; 1207 avl_tree_t *t; 1208 avl_index_t where; 1209 list_t clean_list; 1210 itx_t *itx; 1211 1212 ASSERT(oid != 0); 1213 list_create(&clean_list, sizeof (itx_t), offsetof(itx_t, itx_node)); 1214 1215 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1216 otxg = ZILTEST_TXG; 1217 else 1218 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1219 1220 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1221 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1222 1223 mutex_enter(&itxg->itxg_lock); 1224 if (itxg->itxg_txg != txg) { 1225 mutex_exit(&itxg->itxg_lock); 1226 continue; 1227 } 1228 1229 /* 1230 * Locate the object node and append its list. 1231 */ 1232 t = &itxg->itxg_itxs->i_async_tree; 1233 ian = avl_find(t, &oid, &where); 1234 if (ian != NULL) 1235 list_move_tail(&clean_list, &ian->ia_list); 1236 mutex_exit(&itxg->itxg_lock); 1237 } 1238 while ((itx = list_head(&clean_list)) != NULL) { 1239 list_remove(&clean_list, itx); 1240 kmem_free(itx, offsetof(itx_t, itx_lr) + 1241 itx->itx_lr.lrc_reclen); 1242 } 1243 list_destroy(&clean_list); 1244} 1245 1246void 1247zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx) 1248{ 1249 uint64_t txg; 1250 itxg_t *itxg; 1251 itxs_t *itxs, *clean = NULL; 1252 1253 /* 1254 * Object ids can be re-instantiated in the next txg so 1255 * remove any async transactions to avoid future leaks. 1256 * This can happen if a fsync occurs on the re-instantiated 1257 * object for a WR_INDIRECT or WR_NEED_COPY write, which gets 1258 * the new file data and flushes a write record for the old object. 1259 */ 1260 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_REMOVE) 1261 zil_remove_async(zilog, itx->itx_oid); 1262 1263 /* 1264 * Ensure the data of a renamed file is committed before the rename. 1265 */ 1266 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_RENAME) 1267 zil_async_to_sync(zilog, itx->itx_oid); 1268 1269 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) 1270 txg = ZILTEST_TXG; 1271 else 1272 txg = dmu_tx_get_txg(tx); 1273 1274 itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1275 mutex_enter(&itxg->itxg_lock); 1276 itxs = itxg->itxg_itxs; 1277 if (itxg->itxg_txg != txg) { 1278 if (itxs != NULL) { 1279 /* 1280 * The zil_clean callback hasn't got around to cleaning 1281 * this itxg. Save the itxs for release below. 1282 * This should be rare. 1283 */ 1284 atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod); 1285 itxg->itxg_sod = 0; 1286 clean = itxg->itxg_itxs; 1287 } 1288 ASSERT(itxg->itxg_sod == 0); 1289 itxg->itxg_txg = txg; 1290 itxs = itxg->itxg_itxs = kmem_zalloc(sizeof (itxs_t), KM_SLEEP); 1291 1292 list_create(&itxs->i_sync_list, sizeof (itx_t), 1293 offsetof(itx_t, itx_node)); 1294 avl_create(&itxs->i_async_tree, zil_aitx_compare, 1295 sizeof (itx_async_node_t), 1296 offsetof(itx_async_node_t, ia_node)); 1297 } 1298 if (itx->itx_sync) { 1299 list_insert_tail(&itxs->i_sync_list, itx); 1300 atomic_add_64(&zilog->zl_itx_list_sz, itx->itx_sod); 1301 itxg->itxg_sod += itx->itx_sod; 1302 } else { 1303 avl_tree_t *t = &itxs->i_async_tree; 1304 uint64_t foid = ((lr_ooo_t *)&itx->itx_lr)->lr_foid; 1305 itx_async_node_t *ian; 1306 avl_index_t where; 1307 1308 ian = avl_find(t, &foid, &where); 1309 if (ian == NULL) { 1310 ian = kmem_alloc(sizeof (itx_async_node_t), KM_SLEEP); 1311 list_create(&ian->ia_list, sizeof (itx_t), 1312 offsetof(itx_t, itx_node)); 1313 ian->ia_foid = foid; 1314 avl_insert(t, ian, where); 1315 } 1316 list_insert_tail(&ian->ia_list, itx); 1317 } 1318 1319 itx->itx_lr.lrc_txg = dmu_tx_get_txg(tx); 1320 zilog_dirty(zilog, txg); 1321 mutex_exit(&itxg->itxg_lock); 1322 1323 /* Release the old itxs now we've dropped the lock */ 1324 if (clean != NULL) 1325 zil_itxg_clean(clean); 1326} 1327 1328/* 1329 * If there are any in-memory intent log transactions which have now been 1330 * synced then start up a taskq to free them. We should only do this after we 1331 * have written out the uberblocks (i.e. txg has been comitted) so that 1332 * don't inadvertently clean out in-memory log records that would be required 1333 * by zil_commit(). 1334 */ 1335void 1336zil_clean(zilog_t *zilog, uint64_t synced_txg) 1337{ 1338 itxg_t *itxg = &zilog->zl_itxg[synced_txg & TXG_MASK]; 1339 itxs_t *clean_me; 1340 1341 mutex_enter(&itxg->itxg_lock); 1342 if (itxg->itxg_itxs == NULL || itxg->itxg_txg == ZILTEST_TXG) { 1343 mutex_exit(&itxg->itxg_lock); 1344 return; 1345 } 1346 ASSERT3U(itxg->itxg_txg, <=, synced_txg); 1347 ASSERT(itxg->itxg_txg != 0); 1348 ASSERT(zilog->zl_clean_taskq != NULL); 1349 atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod); 1350 itxg->itxg_sod = 0; 1351 clean_me = itxg->itxg_itxs; 1352 itxg->itxg_itxs = NULL; 1353 itxg->itxg_txg = 0; 1354 mutex_exit(&itxg->itxg_lock); 1355 /* 1356 * Preferably start a task queue to free up the old itxs but 1357 * if taskq_dispatch can't allocate resources to do that then 1358 * free it in-line. This should be rare. Note, using TQ_SLEEP 1359 * created a bad performance problem. 1360 */ 1361 if (taskq_dispatch(zilog->zl_clean_taskq, 1362 (void (*)(void *))zil_itxg_clean, clean_me, TQ_NOSLEEP) == 0) 1363 zil_itxg_clean(clean_me); 1364} 1365 1366/* 1367 * Get the list of itxs to commit into zl_itx_commit_list. 1368 */ 1369static void 1370zil_get_commit_list(zilog_t *zilog) 1371{ 1372 uint64_t otxg, txg; 1373 list_t *commit_list = &zilog->zl_itx_commit_list; 1374 uint64_t push_sod = 0; 1375 1376 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1377 otxg = ZILTEST_TXG; 1378 else 1379 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1380 1381 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1382 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1383 1384 mutex_enter(&itxg->itxg_lock); 1385 if (itxg->itxg_txg != txg) { 1386 mutex_exit(&itxg->itxg_lock); 1387 continue; 1388 } 1389 1390 list_move_tail(commit_list, &itxg->itxg_itxs->i_sync_list); 1391 push_sod += itxg->itxg_sod; 1392 itxg->itxg_sod = 0; 1393 1394 mutex_exit(&itxg->itxg_lock); 1395 } 1396 atomic_add_64(&zilog->zl_itx_list_sz, -push_sod); 1397} 1398 1399/* 1400 * Move the async itxs for a specified object to commit into sync lists. 1401 */ 1402static void 1403zil_async_to_sync(zilog_t *zilog, uint64_t foid) 1404{ 1405 uint64_t otxg, txg; 1406 itx_async_node_t *ian; 1407 avl_tree_t *t; 1408 avl_index_t where; 1409 1410 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1411 otxg = ZILTEST_TXG; 1412 else 1413 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1414 1415 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1416 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1417 1418 mutex_enter(&itxg->itxg_lock); 1419 if (itxg->itxg_txg != txg) { 1420 mutex_exit(&itxg->itxg_lock); 1421 continue; 1422 } 1423 1424 /* 1425 * If a foid is specified then find that node and append its 1426 * list. Otherwise walk the tree appending all the lists 1427 * to the sync list. We add to the end rather than the 1428 * beginning to ensure the create has happened. 1429 */ 1430 t = &itxg->itxg_itxs->i_async_tree; 1431 if (foid != 0) { 1432 ian = avl_find(t, &foid, &where); 1433 if (ian != NULL) { 1434 list_move_tail(&itxg->itxg_itxs->i_sync_list, 1435 &ian->ia_list); 1436 } 1437 } else { 1438 void *cookie = NULL; 1439 1440 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) { 1441 list_move_tail(&itxg->itxg_itxs->i_sync_list, 1442 &ian->ia_list); 1443 list_destroy(&ian->ia_list); 1444 kmem_free(ian, sizeof (itx_async_node_t)); 1445 } 1446 } 1447 mutex_exit(&itxg->itxg_lock); 1448 } 1449} 1450 1451static void 1452zil_commit_writer(zilog_t *zilog) 1453{ 1454 uint64_t txg; 1455 itx_t *itx; 1456 lwb_t *lwb; 1457 spa_t *spa = zilog->zl_spa; 1458 int error = 0; 1459 1460 ASSERT(zilog->zl_root_zio == NULL); 1461 1462 mutex_exit(&zilog->zl_lock); 1463 1464 zil_get_commit_list(zilog); 1465 1466 /* 1467 * Return if there's nothing to commit before we dirty the fs by 1468 * calling zil_create(). 1469 */ 1470 if (list_head(&zilog->zl_itx_commit_list) == NULL) { 1471 mutex_enter(&zilog->zl_lock); 1472 return; 1473 } 1474 1475 if (zilog->zl_suspend) { 1476 lwb = NULL; 1477 } else { 1478 lwb = list_tail(&zilog->zl_lwb_list); 1479 if (lwb == NULL) 1480 lwb = zil_create(zilog); 1481 } 1482 1483 DTRACE_PROBE1(zil__cw1, zilog_t *, zilog); 1484 while (itx = list_head(&zilog->zl_itx_commit_list)) { 1485 txg = itx->itx_lr.lrc_txg; 1486 ASSERT(txg); 1487 1488 if (txg > spa_last_synced_txg(spa) || txg > spa_freeze_txg(spa)) 1489 lwb = zil_lwb_commit(zilog, itx, lwb); 1490 list_remove(&zilog->zl_itx_commit_list, itx); 1491 kmem_free(itx, offsetof(itx_t, itx_lr) 1492 + itx->itx_lr.lrc_reclen); 1493 } 1494 DTRACE_PROBE1(zil__cw2, zilog_t *, zilog); 1495 1496 /* write the last block out */ 1497 if (lwb != NULL && lwb->lwb_zio != NULL) 1498 lwb = zil_lwb_write_start(zilog, lwb); 1499 1500 zilog->zl_cur_used = 0; 1501 1502 /* 1503 * Wait if necessary for the log blocks to be on stable storage. 1504 */ 1505 if (zilog->zl_root_zio) { 1506 error = zio_wait(zilog->zl_root_zio); 1507 zilog->zl_root_zio = NULL; 1508 zil_flush_vdevs(zilog); 1509 } 1510 1511 if (error || lwb == NULL) 1512 txg_wait_synced(zilog->zl_dmu_pool, 0); 1513 1514 mutex_enter(&zilog->zl_lock); 1515 1516 /* 1517 * Remember the highest committed log sequence number for ztest. 1518 * We only update this value when all the log writes succeeded, 1519 * because ztest wants to ASSERT that it got the whole log chain. 1520 */ 1521 if (error == 0 && lwb != NULL) 1522 zilog->zl_commit_lr_seq = zilog->zl_lr_seq; 1523} 1524 1525/* 1526 * Commit zfs transactions to stable storage. 1527 * If foid is 0 push out all transactions, otherwise push only those 1528 * for that object or might reference that object. 1529 * 1530 * itxs are committed in batches. In a heavily stressed zil there will be 1531 * a commit writer thread who is writing out a bunch of itxs to the log 1532 * for a set of committing threads (cthreads) in the same batch as the writer. 1533 * Those cthreads are all waiting on the same cv for that batch. 1534 * 1535 * There will also be a different and growing batch of threads that are 1536 * waiting to commit (qthreads). When the committing batch completes 1537 * a transition occurs such that the cthreads exit and the qthreads become 1538 * cthreads. One of the new cthreads becomes the writer thread for the 1539 * batch. Any new threads arriving become new qthreads. 1540 * 1541 * Only 2 condition variables are needed and there's no transition 1542 * between the two cvs needed. They just flip-flop between qthreads 1543 * and cthreads. 1544 * 1545 * Using this scheme we can efficiently wakeup up only those threads 1546 * that have been committed. 1547 */ 1548void 1549zil_commit(zilog_t *zilog, uint64_t foid) 1550{ 1551 uint64_t mybatch; 1552 1553 if (zilog->zl_sync == ZFS_SYNC_DISABLED) 1554 return; 1555 1556 /* move the async itxs for the foid to the sync queues */ 1557 zil_async_to_sync(zilog, foid); 1558 1559 mutex_enter(&zilog->zl_lock); 1560 mybatch = zilog->zl_next_batch; 1561 while (zilog->zl_writer) { 1562 cv_wait(&zilog->zl_cv_batch[mybatch & 1], &zilog->zl_lock); 1563 if (mybatch <= zilog->zl_com_batch) { 1564 mutex_exit(&zilog->zl_lock); 1565 return; 1566 } 1567 } 1568 1569 zilog->zl_next_batch++; 1570 zilog->zl_writer = B_TRUE; 1571 zil_commit_writer(zilog); 1572 zilog->zl_com_batch = mybatch; 1573 zilog->zl_writer = B_FALSE; 1574 mutex_exit(&zilog->zl_lock); 1575 1576 /* wake up one thread to become the next writer */ 1577 cv_signal(&zilog->zl_cv_batch[(mybatch+1) & 1]); 1578 1579 /* wake up all threads waiting for this batch to be committed */ 1580 cv_broadcast(&zilog->zl_cv_batch[mybatch & 1]); 1581} 1582 1583/* 1584 * Called in syncing context to free committed log blocks and update log header. 1585 */ 1586void 1587zil_sync(zilog_t *zilog, dmu_tx_t *tx) 1588{ 1589 zil_header_t *zh = zil_header_in_syncing_context(zilog); 1590 uint64_t txg = dmu_tx_get_txg(tx); 1591 spa_t *spa = zilog->zl_spa; 1592 uint64_t *replayed_seq = &zilog->zl_replayed_seq[txg & TXG_MASK]; 1593 lwb_t *lwb; 1594 1595 /* 1596 * We don't zero out zl_destroy_txg, so make sure we don't try 1597 * to destroy it twice. 1598 */ 1599 if (spa_sync_pass(spa) != 1) 1600 return; 1601 1602 mutex_enter(&zilog->zl_lock); 1603 1604 ASSERT(zilog->zl_stop_sync == 0); 1605 1606 if (*replayed_seq != 0) { 1607 ASSERT(zh->zh_replay_seq < *replayed_seq); 1608 zh->zh_replay_seq = *replayed_seq; 1609 *replayed_seq = 0; 1610 } 1611 1612 if (zilog->zl_destroy_txg == txg) { 1613 blkptr_t blk = zh->zh_log; 1614 1615 ASSERT(list_head(&zilog->zl_lwb_list) == NULL); 1616 1617 bzero(zh, sizeof (zil_header_t)); 1618 bzero(zilog->zl_replayed_seq, sizeof (zilog->zl_replayed_seq)); 1619 1620 if (zilog->zl_keep_first) { 1621 /* 1622 * If this block was part of log chain that couldn't 1623 * be claimed because a device was missing during 1624 * zil_claim(), but that device later returns, 1625 * then this block could erroneously appear valid. 1626 * To guard against this, assign a new GUID to the new 1627 * log chain so it doesn't matter what blk points to. 1628 */ 1629 zil_init_log_chain(zilog, &blk); 1630 zh->zh_log = blk; 1631 } 1632 } 1633 1634 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { 1635 zh->zh_log = lwb->lwb_blk; 1636 if (lwb->lwb_buf != NULL || lwb->lwb_max_txg > txg) 1637 break; 1638 list_remove(&zilog->zl_lwb_list, lwb); 1639 zio_free_zil(spa, txg, &lwb->lwb_blk); 1640 kmem_cache_free(zil_lwb_cache, lwb); 1641 1642 /* 1643 * If we don't have anything left in the lwb list then 1644 * we've had an allocation failure and we need to zero 1645 * out the zil_header blkptr so that we don't end 1646 * up freeing the same block twice. 1647 */ 1648 if (list_head(&zilog->zl_lwb_list) == NULL) 1649 BP_ZERO(&zh->zh_log); 1650 } 1651 mutex_exit(&zilog->zl_lock); 1652} 1653 1654void 1655zil_init(void) 1656{ 1657 zil_lwb_cache = kmem_cache_create("zil_lwb_cache", 1658 sizeof (struct lwb), 0, NULL, NULL, NULL, NULL, NULL, 0); 1659} 1660 1661void 1662zil_fini(void) 1663{ 1664 kmem_cache_destroy(zil_lwb_cache); 1665} 1666 1667void 1668zil_set_sync(zilog_t *zilog, uint64_t sync) 1669{ 1670 zilog->zl_sync = sync; 1671} 1672 1673void 1674zil_set_logbias(zilog_t *zilog, uint64_t logbias) 1675{ 1676 zilog->zl_logbias = logbias; 1677} 1678 1679zilog_t * 1680zil_alloc(objset_t *os, zil_header_t *zh_phys) 1681{ 1682 zilog_t *zilog; 1683 1684 zilog = kmem_zalloc(sizeof (zilog_t), KM_SLEEP); 1685 1686 zilog->zl_header = zh_phys; 1687 zilog->zl_os = os; 1688 zilog->zl_spa = dmu_objset_spa(os); 1689 zilog->zl_dmu_pool = dmu_objset_pool(os); 1690 zilog->zl_destroy_txg = TXG_INITIAL - 1; 1691 zilog->zl_logbias = dmu_objset_logbias(os); 1692 zilog->zl_sync = dmu_objset_syncprop(os); 1693 zilog->zl_next_batch = 1; 1694 1695 mutex_init(&zilog->zl_lock, NULL, MUTEX_DEFAULT, NULL); 1696 1697 for (int i = 0; i < TXG_SIZE; i++) { 1698 mutex_init(&zilog->zl_itxg[i].itxg_lock, NULL, 1699 MUTEX_DEFAULT, NULL); 1700 } 1701 1702 list_create(&zilog->zl_lwb_list, sizeof (lwb_t), 1703 offsetof(lwb_t, lwb_node)); 1704 1705 list_create(&zilog->zl_itx_commit_list, sizeof (itx_t), 1706 offsetof(itx_t, itx_node)); 1707 1708 mutex_init(&zilog->zl_vdev_lock, NULL, MUTEX_DEFAULT, NULL); 1709 1710 avl_create(&zilog->zl_vdev_tree, zil_vdev_compare, 1711 sizeof (zil_vdev_node_t), offsetof(zil_vdev_node_t, zv_node)); 1712 1713 cv_init(&zilog->zl_cv_writer, NULL, CV_DEFAULT, NULL); 1714 cv_init(&zilog->zl_cv_suspend, NULL, CV_DEFAULT, NULL); 1715 cv_init(&zilog->zl_cv_batch[0], NULL, CV_DEFAULT, NULL); 1716 cv_init(&zilog->zl_cv_batch[1], NULL, CV_DEFAULT, NULL); 1717 1718 return (zilog); 1719} 1720 1721void 1722zil_free(zilog_t *zilog) 1723{ 1724 zilog->zl_stop_sync = 1; 1725 1726 ASSERT0(zilog->zl_suspend); 1727 ASSERT0(zilog->zl_suspending); 1728 1729 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 1730 list_destroy(&zilog->zl_lwb_list); 1731 1732 avl_destroy(&zilog->zl_vdev_tree); 1733 mutex_destroy(&zilog->zl_vdev_lock); 1734 1735 ASSERT(list_is_empty(&zilog->zl_itx_commit_list)); 1736 list_destroy(&zilog->zl_itx_commit_list); 1737 1738 for (int i = 0; i < TXG_SIZE; i++) { 1739 /* 1740 * It's possible for an itx to be generated that doesn't dirty 1741 * a txg (e.g. ztest TX_TRUNCATE). So there's no zil_clean() 1742 * callback to remove the entry. We remove those here. 1743 * 1744 * Also free up the ziltest itxs. 1745 */ 1746 if (zilog->zl_itxg[i].itxg_itxs) 1747 zil_itxg_clean(zilog->zl_itxg[i].itxg_itxs); 1748 mutex_destroy(&zilog->zl_itxg[i].itxg_lock); 1749 } 1750 1751 mutex_destroy(&zilog->zl_lock); 1752 1753 cv_destroy(&zilog->zl_cv_writer); 1754 cv_destroy(&zilog->zl_cv_suspend); 1755 cv_destroy(&zilog->zl_cv_batch[0]); 1756 cv_destroy(&zilog->zl_cv_batch[1]); 1757 1758 kmem_free(zilog, sizeof (zilog_t)); 1759} 1760 1761/* 1762 * Open an intent log. 1763 */ 1764zilog_t * 1765zil_open(objset_t *os, zil_get_data_t *get_data) 1766{ 1767 zilog_t *zilog = dmu_objset_zil(os); 1768 1769 ASSERT(zilog->zl_clean_taskq == NULL); 1770 ASSERT(zilog->zl_get_data == NULL); 1771 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 1772 1773 zilog->zl_get_data = get_data; 1774 zilog->zl_clean_taskq = taskq_create("zil_clean", 1, minclsyspri, 1775 2, 2, TASKQ_PREPOPULATE); 1776 1777 return (zilog); 1778} 1779 1780/* 1781 * Close an intent log. 1782 */ 1783void 1784zil_close(zilog_t *zilog) 1785{ 1786 lwb_t *lwb; 1787 uint64_t txg = 0; 1788 1789 zil_commit(zilog, 0); /* commit all itx */ 1790 1791 /* 1792 * The lwb_max_txg for the stubby lwb will reflect the last activity 1793 * for the zil. After a txg_wait_synced() on the txg we know all the 1794 * callbacks have occurred that may clean the zil. Only then can we 1795 * destroy the zl_clean_taskq. 1796 */ 1797 mutex_enter(&zilog->zl_lock); 1798 lwb = list_tail(&zilog->zl_lwb_list); 1799 if (lwb != NULL) 1800 txg = lwb->lwb_max_txg; 1801 mutex_exit(&zilog->zl_lock); 1802 if (txg) 1803 txg_wait_synced(zilog->zl_dmu_pool, txg); 1804 ASSERT(!zilog_is_dirty(zilog)); 1805 1806 taskq_destroy(zilog->zl_clean_taskq); 1807 zilog->zl_clean_taskq = NULL; 1808 zilog->zl_get_data = NULL; 1809 1810 /* 1811 * We should have only one LWB left on the list; remove it now. 1812 */ 1813 mutex_enter(&zilog->zl_lock); 1814 lwb = list_head(&zilog->zl_lwb_list); 1815 if (lwb != NULL) { 1816 ASSERT(lwb == list_tail(&zilog->zl_lwb_list)); 1817 list_remove(&zilog->zl_lwb_list, lwb); 1818 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 1819 kmem_cache_free(zil_lwb_cache, lwb); 1820 } 1821 mutex_exit(&zilog->zl_lock); 1822} 1823 1824static char *suspend_tag = "zil suspending"; 1825 1826/* 1827 * Suspend an intent log. While in suspended mode, we still honor 1828 * synchronous semantics, but we rely on txg_wait_synced() to do it. 1829 * On old version pools, we suspend the log briefly when taking a 1830 * snapshot so that it will have an empty intent log. 1831 * 1832 * Long holds are not really intended to be used the way we do here -- 1833 * held for such a short time. A concurrent caller of dsl_dataset_long_held() 1834 * could fail. Therefore we take pains to only put a long hold if it is 1835 * actually necessary. Fortunately, it will only be necessary if the 1836 * objset is currently mounted (or the ZVOL equivalent). In that case it 1837 * will already have a long hold, so we are not really making things any worse. 1838 * 1839 * Ideally, we would locate the existing long-holder (i.e. the zfsvfs_t or 1840 * zvol_state_t), and use their mechanism to prevent their hold from being 1841 * dropped (e.g. VFS_HOLD()). However, that would be even more pain for 1842 * very little gain. 1843 * 1844 * if cookiep == NULL, this does both the suspend & resume. 1845 * Otherwise, it returns with the dataset "long held", and the cookie 1846 * should be passed into zil_resume(). 1847 */ 1848int 1849zil_suspend(const char *osname, void **cookiep) 1850{ 1851 objset_t *os; 1852 zilog_t *zilog; 1853 const zil_header_t *zh; 1854 int error; 1855 1856 error = dmu_objset_hold(osname, suspend_tag, &os); 1857 if (error != 0) 1858 return (error); 1859 zilog = dmu_objset_zil(os); 1860 1861 mutex_enter(&zilog->zl_lock); 1862 zh = zilog->zl_header; 1863 1864 if (zh->zh_flags & ZIL_REPLAY_NEEDED) { /* unplayed log */ 1865 mutex_exit(&zilog->zl_lock); 1866 dmu_objset_rele(os, suspend_tag); 1867 return (SET_ERROR(EBUSY)); 1868 } 1869 1870 /* 1871 * Don't put a long hold in the cases where we can avoid it. This 1872 * is when there is no cookie so we are doing a suspend & resume 1873 * (i.e. called from zil_vdev_offline()), and there's nothing to do 1874 * for the suspend because it's already suspended, or there's no ZIL. 1875 */ 1876 if (cookiep == NULL && !zilog->zl_suspending && 1877 (zilog->zl_suspend > 0 || BP_IS_HOLE(&zh->zh_log))) { 1878 mutex_exit(&zilog->zl_lock); 1879 dmu_objset_rele(os, suspend_tag); 1880 return (0); 1881 } 1882 1883 dsl_dataset_long_hold(dmu_objset_ds(os), suspend_tag); 1884 dsl_pool_rele(dmu_objset_pool(os), suspend_tag); 1885 1886 zilog->zl_suspend++; 1887 1888 if (zilog->zl_suspend > 1) { 1889 /* 1890 * Someone else is already suspending it. 1891 * Just wait for them to finish. 1892 */ 1893 1894 while (zilog->zl_suspending) 1895 cv_wait(&zilog->zl_cv_suspend, &zilog->zl_lock); 1896 mutex_exit(&zilog->zl_lock); 1897 1898 if (cookiep == NULL) 1899 zil_resume(os); 1900 else 1901 *cookiep = os; 1902 return (0); 1903 } 1904 1905 /* 1906 * If there is no pointer to an on-disk block, this ZIL must not 1907 * be active (e.g. filesystem not mounted), so there's nothing 1908 * to clean up. 1909 */ 1910 if (BP_IS_HOLE(&zh->zh_log)) { 1911 ASSERT(cookiep != NULL); /* fast path already handled */ 1912 1913 *cookiep = os; 1914 mutex_exit(&zilog->zl_lock); 1915 return (0); 1916 } 1917 1918 zilog->zl_suspending = B_TRUE; 1919 mutex_exit(&zilog->zl_lock); 1920 1921 zil_commit(zilog, 0); 1922 1923 zil_destroy(zilog, B_FALSE); 1924 1925 mutex_enter(&zilog->zl_lock); 1926 zilog->zl_suspending = B_FALSE; 1927 cv_broadcast(&zilog->zl_cv_suspend); 1928 mutex_exit(&zilog->zl_lock); 1929 1930 if (cookiep == NULL) 1931 zil_resume(os); 1932 else 1933 *cookiep = os; 1934 return (0); 1935} 1936 1937void 1938zil_resume(void *cookie) 1939{ 1940 objset_t *os = cookie; 1941 zilog_t *zilog = dmu_objset_zil(os); 1942 1943 mutex_enter(&zilog->zl_lock); 1944 ASSERT(zilog->zl_suspend != 0); 1945 zilog->zl_suspend--; 1946 mutex_exit(&zilog->zl_lock); 1947 dsl_dataset_long_rele(dmu_objset_ds(os), suspend_tag); 1948 dsl_dataset_rele(dmu_objset_ds(os), suspend_tag); 1949} 1950 1951typedef struct zil_replay_arg { 1952 zil_replay_func_t **zr_replay; 1953 void *zr_arg; 1954 boolean_t zr_byteswap; 1955 char *zr_lr; 1956} zil_replay_arg_t; 1957 1958static int 1959zil_replay_error(zilog_t *zilog, lr_t *lr, int error) 1960{ 1961 char name[MAXNAMELEN]; 1962 1963 zilog->zl_replaying_seq--; /* didn't actually replay this one */ 1964 1965 dmu_objset_name(zilog->zl_os, name); 1966 1967 cmn_err(CE_WARN, "ZFS replay transaction error %d, " 1968 "dataset %s, seq 0x%llx, txtype %llu %s\n", error, name, 1969 (u_longlong_t)lr->lrc_seq, 1970 (u_longlong_t)(lr->lrc_txtype & ~TX_CI), 1971 (lr->lrc_txtype & TX_CI) ? "CI" : ""); 1972 1973 return (error); 1974} 1975 1976static int 1977zil_replay_log_record(zilog_t *zilog, lr_t *lr, void *zra, uint64_t claim_txg) 1978{ 1979 zil_replay_arg_t *zr = zra; 1980 const zil_header_t *zh = zilog->zl_header; 1981 uint64_t reclen = lr->lrc_reclen; 1982 uint64_t txtype = lr->lrc_txtype; 1983 int error = 0; 1984 1985 zilog->zl_replaying_seq = lr->lrc_seq; 1986 1987 if (lr->lrc_seq <= zh->zh_replay_seq) /* already replayed */ 1988 return (0); 1989 1990 if (lr->lrc_txg < claim_txg) /* already committed */ 1991 return (0); 1992 1993 /* Strip case-insensitive bit, still present in log record */ 1994 txtype &= ~TX_CI; 1995 1996 if (txtype == 0 || txtype >= TX_MAX_TYPE) 1997 return (zil_replay_error(zilog, lr, EINVAL)); 1998 1999 /* 2000 * If this record type can be logged out of order, the object 2001 * (lr_foid) may no longer exist. That's legitimate, not an error. 2002 */ 2003 if (TX_OOO(txtype)) { 2004 error = dmu_object_info(zilog->zl_os, 2005 ((lr_ooo_t *)lr)->lr_foid, NULL); 2006 if (error == ENOENT || error == EEXIST) 2007 return (0); 2008 } 2009 2010 /* 2011 * Make a copy of the data so we can revise and extend it. 2012 */ 2013 bcopy(lr, zr->zr_lr, reclen); 2014 2015 /* 2016 * If this is a TX_WRITE with a blkptr, suck in the data. 2017 */ 2018 if (txtype == TX_WRITE && reclen == sizeof (lr_write_t)) { 2019 error = zil_read_log_data(zilog, (lr_write_t *)lr, 2020 zr->zr_lr + reclen); 2021 if (error != 0) 2022 return (zil_replay_error(zilog, lr, error)); 2023 } 2024 2025 /* 2026 * The log block containing this lr may have been byteswapped 2027 * so that we can easily examine common fields like lrc_txtype. 2028 * However, the log is a mix of different record types, and only the 2029 * replay vectors know how to byteswap their records. Therefore, if 2030 * the lr was byteswapped, undo it before invoking the replay vector. 2031 */ 2032 if (zr->zr_byteswap) 2033 byteswap_uint64_array(zr->zr_lr, reclen); 2034 2035 /* 2036 * We must now do two things atomically: replay this log record, 2037 * and update the log header sequence number to reflect the fact that 2038 * we did so. At the end of each replay function the sequence number 2039 * is updated if we are in replay mode. 2040 */ 2041 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, zr->zr_byteswap); 2042 if (error != 0) { 2043 /* 2044 * The DMU's dnode layer doesn't see removes until the txg 2045 * commits, so a subsequent claim can spuriously fail with 2046 * EEXIST. So if we receive any error we try syncing out 2047 * any removes then retry the transaction. Note that we 2048 * specify B_FALSE for byteswap now, so we don't do it twice. 2049 */ 2050 txg_wait_synced(spa_get_dsl(zilog->zl_spa), 0); 2051 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, B_FALSE); 2052 if (error != 0) 2053 return (zil_replay_error(zilog, lr, error)); 2054 } 2055 return (0); 2056} 2057 2058/* ARGSUSED */ 2059static int 2060zil_incr_blks(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg) 2061{ 2062 zilog->zl_replay_blks++; 2063 2064 return (0); 2065} 2066 2067/* 2068 * If this dataset has a non-empty intent log, replay it and destroy it. 2069 */ 2070void 2071zil_replay(objset_t *os, void *arg, zil_replay_func_t *replay_func[TX_MAX_TYPE]) 2072{ 2073 zilog_t *zilog = dmu_objset_zil(os); 2074 const zil_header_t *zh = zilog->zl_header; 2075 zil_replay_arg_t zr; 2076 2077 if ((zh->zh_flags & ZIL_REPLAY_NEEDED) == 0) { 2078 zil_destroy(zilog, B_TRUE); 2079 return; 2080 } 2081 //printf("ZFS: Replaying ZIL on %s...\n", os->os->os_spa->spa_name); 2082 2083 zr.zr_replay = replay_func; 2084 zr.zr_arg = arg; 2085 zr.zr_byteswap = BP_SHOULD_BYTESWAP(&zh->zh_log); 2086 zr.zr_lr = kmem_alloc(2 * SPA_MAXBLOCKSIZE, KM_SLEEP); 2087 2088 /* 2089 * Wait for in-progress removes to sync before starting replay. 2090 */ 2091 txg_wait_synced(zilog->zl_dmu_pool, 0); 2092 2093 zilog->zl_replay = B_TRUE; 2094 zilog->zl_replay_time = ddi_get_lbolt(); 2095 ASSERT(zilog->zl_replay_blks == 0); 2096 (void) zil_parse(zilog, zil_incr_blks, zil_replay_log_record, &zr, 2097 zh->zh_claim_txg); 2098 kmem_free(zr.zr_lr, 2 * SPA_MAXBLOCKSIZE); 2099 2100 zil_destroy(zilog, B_FALSE); 2101 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 2102 zilog->zl_replay = B_FALSE; 2103 //printf("ZFS: Replay of ZIL on %s finished.\n", os->os->os_spa->spa_name); 2104} 2105 2106boolean_t 2107zil_replaying(zilog_t *zilog, dmu_tx_t *tx) 2108{ 2109 if (zilog->zl_sync == ZFS_SYNC_DISABLED) 2110 return (B_TRUE); 2111 2112 if (zilog->zl_replay) { 2113 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 2114 zilog->zl_replayed_seq[dmu_tx_get_txg(tx) & TXG_MASK] = 2115 zilog->zl_replaying_seq; 2116 return (B_TRUE); 2117 } 2118 2119 return (B_FALSE); 2120} 2121 2122/* ARGSUSED */ 2123int 2124zil_vdev_offline(const char *osname, void *arg) 2125{ 2126 int error; 2127 2128 error = zil_suspend(osname, NULL); 2129 if (error != 0) 2130 return (SET_ERROR(EEXIST)); 2131 return (0); 2132} 2133