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, 2016 by Delphix. All rights reserved. 24 * Copyright (c) 2014 Integros [integros.com] 25 */ 26 27/* Portions Copyright 2010 Robert Milkowski */ 28 29#include <sys/zfs_context.h> 30#include <sys/spa.h> 31#include <sys/dmu.h> 32#include <sys/zap.h> 33#include <sys/arc.h> 34#include <sys/stat.h> 35#include <sys/resource.h> 36#include <sys/zil.h> 37#include <sys/zil_impl.h> 38#include <sys/dsl_dataset.h> 39#include <sys/vdev_impl.h> 40#include <sys/dmu_tx.h> 41#include <sys/dsl_pool.h> 42 43/* 44 * The zfs intent log (ZIL) saves transaction records of system calls 45 * that change the file system in memory with enough information 46 * to be able to replay them. These are stored in memory until 47 * either the DMU transaction group (txg) commits them to the stable pool 48 * and they can be discarded, or they are flushed to the stable log 49 * (also in the pool) due to a fsync, O_DSYNC or other synchronous 50 * requirement. In the event of a panic or power fail then those log 51 * records (transactions) are replayed. 52 * 53 * There is one ZIL per file system. Its on-disk (pool) format consists 54 * of 3 parts: 55 * 56 * - ZIL header 57 * - ZIL blocks 58 * - ZIL records 59 * 60 * A log record holds a system call transaction. Log blocks can 61 * hold many log records and the blocks are chained together. 62 * Each ZIL block contains a block pointer (blkptr_t) to the next 63 * ZIL block in the chain. The ZIL header points to the first 64 * block in the chain. Note there is not a fixed place in the pool 65 * to hold blocks. They are dynamically allocated and freed as 66 * needed from the blocks available. Figure X shows the ZIL structure: 67 */ 68 69/* 70 * Disable intent logging replay. This global ZIL switch affects all pools. 71 */ 72int zil_replay_disable = 0; 73SYSCTL_DECL(_vfs_zfs); 74SYSCTL_INT(_vfs_zfs, OID_AUTO, zil_replay_disable, CTLFLAG_RWTUN, 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; 83SYSCTL_INT(_vfs_zfs, OID_AUTO, cache_flush_disable, CTLFLAG_RDTUN, 84 &zfs_nocacheflush, 0, "Disable cache flush"); 85boolean_t zfs_trim_enabled = B_TRUE; 86SYSCTL_DECL(_vfs_zfs_trim); 87SYSCTL_INT(_vfs_zfs_trim, OID_AUTO, enabled, CTLFLAG_RDTUN, &zfs_trim_enabled, 0, 88 "Enable ZFS TRIM"); 89 90/* 91 * Limit SLOG write size per commit executed with synchronous priority. 92 * Any writes above that executed with lower (asynchronous) priority to 93 * limit potential SLOG device abuse by single active ZIL writer. 94 */ 95uint64_t zil_slog_limit = 768 * 1024; 96SYSCTL_QUAD(_vfs_zfs, OID_AUTO, zil_slog_limit, CTLFLAG_RWTUN, 97 &zil_slog_limit, 0, "Maximal SLOG commit size with sync priority"); 98 99static kmem_cache_t *zil_lwb_cache; 100 101#define LWB_EMPTY(lwb) ((BP_GET_LSIZE(&lwb->lwb_blk) - \ 102 sizeof (zil_chain_t)) == (lwb->lwb_sz - lwb->lwb_nused)) 103 104 105/* 106 * ziltest is by and large an ugly hack, but very useful in 107 * checking replay without tedious work. 108 * When running ziltest we want to keep all itx's and so maintain 109 * a single list in the zl_itxg[] that uses a high txg: ZILTEST_TXG 110 * We subtract TXG_CONCURRENT_STATES to allow for common code. 111 */ 112#define ZILTEST_TXG (UINT64_MAX - TXG_CONCURRENT_STATES) 113 114static int 115zil_bp_compare(const void *x1, const void *x2) 116{ 117 const dva_t *dva1 = &((zil_bp_node_t *)x1)->zn_dva; 118 const dva_t *dva2 = &((zil_bp_node_t *)x2)->zn_dva; 119 120 if (DVA_GET_VDEV(dva1) < DVA_GET_VDEV(dva2)) 121 return (-1); 122 if (DVA_GET_VDEV(dva1) > DVA_GET_VDEV(dva2)) 123 return (1); 124 125 if (DVA_GET_OFFSET(dva1) < DVA_GET_OFFSET(dva2)) 126 return (-1); 127 if (DVA_GET_OFFSET(dva1) > DVA_GET_OFFSET(dva2)) 128 return (1); 129 130 return (0); 131} 132 133static void 134zil_bp_tree_init(zilog_t *zilog) 135{ 136 avl_create(&zilog->zl_bp_tree, zil_bp_compare, 137 sizeof (zil_bp_node_t), offsetof(zil_bp_node_t, zn_node)); 138} 139 140static void 141zil_bp_tree_fini(zilog_t *zilog) 142{ 143 avl_tree_t *t = &zilog->zl_bp_tree; 144 zil_bp_node_t *zn; 145 void *cookie = NULL; 146 147 while ((zn = avl_destroy_nodes(t, &cookie)) != NULL) 148 kmem_free(zn, sizeof (zil_bp_node_t)); 149 150 avl_destroy(t); 151} 152 153int 154zil_bp_tree_add(zilog_t *zilog, const blkptr_t *bp) 155{ 156 avl_tree_t *t = &zilog->zl_bp_tree; 157 const dva_t *dva; 158 zil_bp_node_t *zn; 159 avl_index_t where; 160 161 if (BP_IS_EMBEDDED(bp)) 162 return (0); 163 164 dva = BP_IDENTITY(bp); 165 166 if (avl_find(t, dva, &where) != NULL) 167 return (SET_ERROR(EEXIST)); 168 169 zn = kmem_alloc(sizeof (zil_bp_node_t), KM_SLEEP); 170 zn->zn_dva = *dva; 171 avl_insert(t, zn, where); 172 173 return (0); 174} 175 176static zil_header_t * 177zil_header_in_syncing_context(zilog_t *zilog) 178{ 179 return ((zil_header_t *)zilog->zl_header); 180} 181 182static void 183zil_init_log_chain(zilog_t *zilog, blkptr_t *bp) 184{ 185 zio_cksum_t *zc = &bp->blk_cksum; 186 187 zc->zc_word[ZIL_ZC_GUID_0] = spa_get_random(-1ULL); 188 zc->zc_word[ZIL_ZC_GUID_1] = spa_get_random(-1ULL); 189 zc->zc_word[ZIL_ZC_OBJSET] = dmu_objset_id(zilog->zl_os); 190 zc->zc_word[ZIL_ZC_SEQ] = 1ULL; 191} 192 193/* 194 * Read a log block and make sure it's valid. 195 */ 196static int 197zil_read_log_block(zilog_t *zilog, const blkptr_t *bp, blkptr_t *nbp, void *dst, 198 char **end) 199{ 200 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL; 201 arc_flags_t aflags = ARC_FLAG_WAIT; 202 arc_buf_t *abuf = NULL; 203 zbookmark_phys_t zb; 204 int error; 205 206 if (zilog->zl_header->zh_claim_txg == 0) 207 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; 208 209 if (!(zilog->zl_header->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) 210 zio_flags |= ZIO_FLAG_SPECULATIVE; 211 212 SET_BOOKMARK(&zb, bp->blk_cksum.zc_word[ZIL_ZC_OBJSET], 213 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]); 214 215 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf, 216 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); 217 218 if (error == 0) { 219 zio_cksum_t cksum = bp->blk_cksum; 220 221 /* 222 * Validate the checksummed log block. 223 * 224 * Sequence numbers should be... sequential. The checksum 225 * verifier for the next block should be bp's checksum plus 1. 226 * 227 * Also check the log chain linkage and size used. 228 */ 229 cksum.zc_word[ZIL_ZC_SEQ]++; 230 231 if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) { 232 zil_chain_t *zilc = abuf->b_data; 233 char *lr = (char *)(zilc + 1); 234 uint64_t len = zilc->zc_nused - sizeof (zil_chain_t); 235 236 if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum, 237 sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk)) { 238 error = SET_ERROR(ECKSUM); 239 } else { 240 ASSERT3U(len, <=, SPA_OLD_MAXBLOCKSIZE); 241 bcopy(lr, dst, len); 242 *end = (char *)dst + len; 243 *nbp = zilc->zc_next_blk; 244 } 245 } else { 246 char *lr = abuf->b_data; 247 uint64_t size = BP_GET_LSIZE(bp); 248 zil_chain_t *zilc = (zil_chain_t *)(lr + size) - 1; 249 250 if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum, 251 sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk) || 252 (zilc->zc_nused > (size - sizeof (*zilc)))) { 253 error = SET_ERROR(ECKSUM); 254 } else { 255 ASSERT3U(zilc->zc_nused, <=, 256 SPA_OLD_MAXBLOCKSIZE); 257 bcopy(lr, dst, zilc->zc_nused); 258 *end = (char *)dst + zilc->zc_nused; 259 *nbp = zilc->zc_next_blk; 260 } 261 } 262 263 arc_buf_destroy(abuf, &abuf); 264 } 265 266 return (error); 267} 268 269/* 270 * Read a TX_WRITE log data block. 271 */ 272static int 273zil_read_log_data(zilog_t *zilog, const lr_write_t *lr, void *wbuf) 274{ 275 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL; 276 const blkptr_t *bp = &lr->lr_blkptr; 277 arc_flags_t aflags = ARC_FLAG_WAIT; 278 arc_buf_t *abuf = NULL; 279 zbookmark_phys_t zb; 280 int error; 281 282 if (BP_IS_HOLE(bp)) { 283 if (wbuf != NULL) 284 bzero(wbuf, MAX(BP_GET_LSIZE(bp), lr->lr_length)); 285 return (0); 286 } 287 288 if (zilog->zl_header->zh_claim_txg == 0) 289 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; 290 291 SET_BOOKMARK(&zb, dmu_objset_id(zilog->zl_os), lr->lr_foid, 292 ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp)); 293 294 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf, 295 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); 296 297 if (error == 0) { 298 if (wbuf != NULL) 299 bcopy(abuf->b_data, wbuf, arc_buf_size(abuf)); 300 arc_buf_destroy(abuf, &abuf); 301 } 302 303 return (error); 304} 305 306/* 307 * Parse the intent log, and call parse_func for each valid record within. 308 */ 309int 310zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func, 311 zil_parse_lr_func_t *parse_lr_func, void *arg, uint64_t txg) 312{ 313 const zil_header_t *zh = zilog->zl_header; 314 boolean_t claimed = !!zh->zh_claim_txg; 315 uint64_t claim_blk_seq = claimed ? zh->zh_claim_blk_seq : UINT64_MAX; 316 uint64_t claim_lr_seq = claimed ? zh->zh_claim_lr_seq : UINT64_MAX; 317 uint64_t max_blk_seq = 0; 318 uint64_t max_lr_seq = 0; 319 uint64_t blk_count = 0; 320 uint64_t lr_count = 0; 321 blkptr_t blk, next_blk; 322 char *lrbuf, *lrp; 323 int error = 0; 324 325 /* 326 * Old logs didn't record the maximum zh_claim_lr_seq. 327 */ 328 if (!(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) 329 claim_lr_seq = UINT64_MAX; 330 331 /* 332 * Starting at the block pointed to by zh_log we read the log chain. 333 * For each block in the chain we strongly check that block to 334 * ensure its validity. We stop when an invalid block is found. 335 * For each block pointer in the chain we call parse_blk_func(). 336 * For each record in each valid block we call parse_lr_func(). 337 * If the log has been claimed, stop if we encounter a sequence 338 * number greater than the highest claimed sequence number. 339 */ 340 lrbuf = zio_buf_alloc(SPA_OLD_MAXBLOCKSIZE); 341 zil_bp_tree_init(zilog); 342 343 for (blk = zh->zh_log; !BP_IS_HOLE(&blk); blk = next_blk) { 344 uint64_t blk_seq = blk.blk_cksum.zc_word[ZIL_ZC_SEQ]; 345 int reclen; 346 char *end; 347 348 if (blk_seq > claim_blk_seq) 349 break; 350 if ((error = parse_blk_func(zilog, &blk, arg, txg)) != 0) 351 break; 352 ASSERT3U(max_blk_seq, <, blk_seq); 353 max_blk_seq = blk_seq; 354 blk_count++; 355 356 if (max_lr_seq == claim_lr_seq && max_blk_seq == claim_blk_seq) 357 break; 358 359 error = zil_read_log_block(zilog, &blk, &next_blk, lrbuf, &end); 360 if (error != 0) 361 break; 362 363 for (lrp = lrbuf; lrp < end; lrp += reclen) { 364 lr_t *lr = (lr_t *)lrp; 365 reclen = lr->lrc_reclen; 366 ASSERT3U(reclen, >=, sizeof (lr_t)); 367 if (lr->lrc_seq > claim_lr_seq) 368 goto done; 369 if ((error = parse_lr_func(zilog, lr, arg, txg)) != 0) 370 goto done; 371 ASSERT3U(max_lr_seq, <, lr->lrc_seq); 372 max_lr_seq = lr->lrc_seq; 373 lr_count++; 374 } 375 } 376done: 377 zilog->zl_parse_error = error; 378 zilog->zl_parse_blk_seq = max_blk_seq; 379 zilog->zl_parse_lr_seq = max_lr_seq; 380 zilog->zl_parse_blk_count = blk_count; 381 zilog->zl_parse_lr_count = lr_count; 382 383 ASSERT(!claimed || !(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID) || 384 (max_blk_seq == claim_blk_seq && max_lr_seq == claim_lr_seq)); 385 386 zil_bp_tree_fini(zilog); 387 zio_buf_free(lrbuf, SPA_OLD_MAXBLOCKSIZE); 388 389 return (error); 390} 391 392static int 393zil_claim_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t first_txg) 394{ 395 /* 396 * Claim log block if not already committed and not already claimed. 397 * If tx == NULL, just verify that the block is claimable. 398 */ 399 if (BP_IS_HOLE(bp) || bp->blk_birth < first_txg || 400 zil_bp_tree_add(zilog, bp) != 0) 401 return (0); 402 403 return (zio_wait(zio_claim(NULL, zilog->zl_spa, 404 tx == NULL ? 0 : first_txg, bp, spa_claim_notify, NULL, 405 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB))); 406} 407 408static int 409zil_claim_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t first_txg) 410{ 411 lr_write_t *lr = (lr_write_t *)lrc; 412 int error; 413 414 if (lrc->lrc_txtype != TX_WRITE) 415 return (0); 416 417 /* 418 * If the block is not readable, don't claim it. This can happen 419 * in normal operation when a log block is written to disk before 420 * some of the dmu_sync() blocks it points to. In this case, the 421 * transaction cannot have been committed to anyone (we would have 422 * waited for all writes to be stable first), so it is semantically 423 * correct to declare this the end of the log. 424 */ 425 if (lr->lr_blkptr.blk_birth >= first_txg && 426 (error = zil_read_log_data(zilog, lr, NULL)) != 0) 427 return (error); 428 return (zil_claim_log_block(zilog, &lr->lr_blkptr, tx, first_txg)); 429} 430 431/* ARGSUSED */ 432static int 433zil_free_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t claim_txg) 434{ 435 zio_free_zil(zilog->zl_spa, dmu_tx_get_txg(tx), bp); 436 437 return (0); 438} 439 440static int 441zil_free_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t claim_txg) 442{ 443 lr_write_t *lr = (lr_write_t *)lrc; 444 blkptr_t *bp = &lr->lr_blkptr; 445 446 /* 447 * If we previously claimed it, we need to free it. 448 */ 449 if (claim_txg != 0 && lrc->lrc_txtype == TX_WRITE && 450 bp->blk_birth >= claim_txg && zil_bp_tree_add(zilog, bp) == 0 && 451 !BP_IS_HOLE(bp)) 452 zio_free(zilog->zl_spa, dmu_tx_get_txg(tx), bp); 453 454 return (0); 455} 456 457static lwb_t * 458zil_alloc_lwb(zilog_t *zilog, blkptr_t *bp, boolean_t slog, uint64_t txg) 459{ 460 lwb_t *lwb; 461 462 lwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP); 463 lwb->lwb_zilog = zilog; 464 lwb->lwb_blk = *bp; 465 lwb->lwb_slog = slog; 466 lwb->lwb_buf = zio_buf_alloc(BP_GET_LSIZE(bp)); 467 lwb->lwb_max_txg = txg; 468 lwb->lwb_zio = NULL; 469 lwb->lwb_tx = NULL; 470 if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) { 471 lwb->lwb_nused = sizeof (zil_chain_t); 472 lwb->lwb_sz = BP_GET_LSIZE(bp); 473 } else { 474 lwb->lwb_nused = 0; 475 lwb->lwb_sz = BP_GET_LSIZE(bp) - sizeof (zil_chain_t); 476 } 477 478 mutex_enter(&zilog->zl_lock); 479 list_insert_tail(&zilog->zl_lwb_list, lwb); 480 mutex_exit(&zilog->zl_lock); 481 482 return (lwb); 483} 484 485/* 486 * Called when we create in-memory log transactions so that we know 487 * to cleanup the itxs at the end of spa_sync(). 488 */ 489void 490zilog_dirty(zilog_t *zilog, uint64_t txg) 491{ 492 dsl_pool_t *dp = zilog->zl_dmu_pool; 493 dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os); 494 495 if (ds->ds_is_snapshot) 496 panic("dirtying snapshot!"); 497 498 if (txg_list_add(&dp->dp_dirty_zilogs, zilog, txg)) { 499 /* up the hold count until we can be written out */ 500 dmu_buf_add_ref(ds->ds_dbuf, zilog); 501 } 502} 503 504/* 505 * Determine if the zil is dirty in the specified txg. Callers wanting to 506 * ensure that the dirty state does not change must hold the itxg_lock for 507 * the specified txg. Holding the lock will ensure that the zil cannot be 508 * dirtied (zil_itx_assign) or cleaned (zil_clean) while we check its current 509 * state. 510 */ 511boolean_t 512zilog_is_dirty_in_txg(zilog_t *zilog, uint64_t txg) 513{ 514 dsl_pool_t *dp = zilog->zl_dmu_pool; 515 516 if (txg_list_member(&dp->dp_dirty_zilogs, zilog, txg & TXG_MASK)) 517 return (B_TRUE); 518 return (B_FALSE); 519} 520 521/* 522 * Determine if the zil is dirty. The zil is considered dirty if it has 523 * any pending itx records that have not been cleaned by zil_clean(). 524 */ 525boolean_t 526zilog_is_dirty(zilog_t *zilog) 527{ 528 dsl_pool_t *dp = zilog->zl_dmu_pool; 529 530 for (int t = 0; t < TXG_SIZE; t++) { 531 if (txg_list_member(&dp->dp_dirty_zilogs, zilog, t)) 532 return (B_TRUE); 533 } 534 return (B_FALSE); 535} 536 537/* 538 * Create an on-disk intent log. 539 */ 540static lwb_t * 541zil_create(zilog_t *zilog) 542{ 543 const zil_header_t *zh = zilog->zl_header; 544 lwb_t *lwb = NULL; 545 uint64_t txg = 0; 546 dmu_tx_t *tx = NULL; 547 blkptr_t blk; 548 int error = 0; 549 boolean_t slog = FALSE; 550 551 /* 552 * Wait for any previous destroy to complete. 553 */ 554 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 555 556 ASSERT(zh->zh_claim_txg == 0); 557 ASSERT(zh->zh_replay_seq == 0); 558 559 blk = zh->zh_log; 560 561 /* 562 * Allocate an initial log block if: 563 * - there isn't one already 564 * - the existing block is the wrong endianess 565 */ 566 if (BP_IS_HOLE(&blk) || BP_SHOULD_BYTESWAP(&blk)) { 567 tx = dmu_tx_create(zilog->zl_os); 568 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 569 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 570 txg = dmu_tx_get_txg(tx); 571 572 if (!BP_IS_HOLE(&blk)) { 573 zio_free_zil(zilog->zl_spa, txg, &blk); 574 BP_ZERO(&blk); 575 } 576 577 error = zio_alloc_zil(zilog->zl_spa, txg, &blk, NULL, 578 ZIL_MIN_BLKSZ, &slog); 579 580 if (error == 0) 581 zil_init_log_chain(zilog, &blk); 582 } 583 584 /* 585 * Allocate a log write buffer (lwb) for the first log block. 586 */ 587 if (error == 0) 588 lwb = zil_alloc_lwb(zilog, &blk, slog, txg); 589 590 /* 591 * If we just allocated the first log block, commit our transaction 592 * and wait for zil_sync() to stuff the block poiner into zh_log. 593 * (zh is part of the MOS, so we cannot modify it in open context.) 594 */ 595 if (tx != NULL) { 596 dmu_tx_commit(tx); 597 txg_wait_synced(zilog->zl_dmu_pool, txg); 598 } 599 600 ASSERT(bcmp(&blk, &zh->zh_log, sizeof (blk)) == 0); 601 602 return (lwb); 603} 604 605/* 606 * In one tx, free all log blocks and clear the log header. 607 * If keep_first is set, then we're replaying a log with no content. 608 * We want to keep the first block, however, so that the first 609 * synchronous transaction doesn't require a txg_wait_synced() 610 * in zil_create(). We don't need to txg_wait_synced() here either 611 * when keep_first is set, because both zil_create() and zil_destroy() 612 * will wait for any in-progress destroys to complete. 613 */ 614void 615zil_destroy(zilog_t *zilog, boolean_t keep_first) 616{ 617 const zil_header_t *zh = zilog->zl_header; 618 lwb_t *lwb; 619 dmu_tx_t *tx; 620 uint64_t txg; 621 622 /* 623 * Wait for any previous destroy to complete. 624 */ 625 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 626 627 zilog->zl_old_header = *zh; /* debugging aid */ 628 629 if (BP_IS_HOLE(&zh->zh_log)) 630 return; 631 632 tx = dmu_tx_create(zilog->zl_os); 633 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 634 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 635 txg = dmu_tx_get_txg(tx); 636 637 mutex_enter(&zilog->zl_lock); 638 639 ASSERT3U(zilog->zl_destroy_txg, <, txg); 640 zilog->zl_destroy_txg = txg; 641 zilog->zl_keep_first = keep_first; 642 643 if (!list_is_empty(&zilog->zl_lwb_list)) { 644 ASSERT(zh->zh_claim_txg == 0); 645 VERIFY(!keep_first); 646 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { 647 list_remove(&zilog->zl_lwb_list, lwb); 648 if (lwb->lwb_buf != NULL) 649 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 650 zio_free_zil(zilog->zl_spa, txg, &lwb->lwb_blk); 651 kmem_cache_free(zil_lwb_cache, lwb); 652 } 653 } else if (!keep_first) { 654 zil_destroy_sync(zilog, tx); 655 } 656 mutex_exit(&zilog->zl_lock); 657 658 dmu_tx_commit(tx); 659} 660 661void 662zil_destroy_sync(zilog_t *zilog, dmu_tx_t *tx) 663{ 664 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 665 (void) zil_parse(zilog, zil_free_log_block, 666 zil_free_log_record, tx, zilog->zl_header->zh_claim_txg); 667} 668 669int 670zil_claim(dsl_pool_t *dp, dsl_dataset_t *ds, void *txarg) 671{ 672 dmu_tx_t *tx = txarg; 673 uint64_t first_txg = dmu_tx_get_txg(tx); 674 zilog_t *zilog; 675 zil_header_t *zh; 676 objset_t *os; 677 int error; 678 679 error = dmu_objset_own_obj(dp, ds->ds_object, 680 DMU_OST_ANY, B_FALSE, FTAG, &os); 681 if (error != 0) { 682 /* 683 * EBUSY indicates that the objset is inconsistent, in which 684 * case it can not have a ZIL. 685 */ 686 if (error != EBUSY) { 687 cmn_err(CE_WARN, "can't open objset for %llu, error %u", 688 (unsigned long long)ds->ds_object, error); 689 } 690 return (0); 691 } 692 693 zilog = dmu_objset_zil(os); 694 zh = zil_header_in_syncing_context(zilog); 695 696 if (spa_get_log_state(zilog->zl_spa) == SPA_LOG_CLEAR) { 697 if (!BP_IS_HOLE(&zh->zh_log)) 698 zio_free_zil(zilog->zl_spa, first_txg, &zh->zh_log); 699 BP_ZERO(&zh->zh_log); 700 dsl_dataset_dirty(dmu_objset_ds(os), tx); 701 dmu_objset_disown(os, FTAG); 702 return (0); 703 } 704 705 /* 706 * Claim all log blocks if we haven't already done so, and remember 707 * the highest claimed sequence number. This ensures that if we can 708 * read only part of the log now (e.g. due to a missing device), 709 * but we can read the entire log later, we will not try to replay 710 * or destroy beyond the last block we successfully claimed. 711 */ 712 ASSERT3U(zh->zh_claim_txg, <=, first_txg); 713 if (zh->zh_claim_txg == 0 && !BP_IS_HOLE(&zh->zh_log)) { 714 (void) zil_parse(zilog, zil_claim_log_block, 715 zil_claim_log_record, tx, first_txg); 716 zh->zh_claim_txg = first_txg; 717 zh->zh_claim_blk_seq = zilog->zl_parse_blk_seq; 718 zh->zh_claim_lr_seq = zilog->zl_parse_lr_seq; 719 if (zilog->zl_parse_lr_count || zilog->zl_parse_blk_count > 1) 720 zh->zh_flags |= ZIL_REPLAY_NEEDED; 721 zh->zh_flags |= ZIL_CLAIM_LR_SEQ_VALID; 722 dsl_dataset_dirty(dmu_objset_ds(os), tx); 723 } 724 725 ASSERT3U(first_txg, ==, (spa_last_synced_txg(zilog->zl_spa) + 1)); 726 dmu_objset_disown(os, FTAG); 727 return (0); 728} 729 730/* 731 * Check the log by walking the log chain. 732 * Checksum errors are ok as they indicate the end of the chain. 733 * Any other error (no device or read failure) returns an error. 734 */ 735/* ARGSUSED */ 736int 737zil_check_log_chain(dsl_pool_t *dp, dsl_dataset_t *ds, void *tx) 738{ 739 zilog_t *zilog; 740 objset_t *os; 741 blkptr_t *bp; 742 int error; 743 744 ASSERT(tx == NULL); 745 746 error = dmu_objset_from_ds(ds, &os); 747 if (error != 0) { 748 cmn_err(CE_WARN, "can't open objset %llu, error %d", 749 (unsigned long long)ds->ds_object, error); 750 return (0); 751 } 752 753 zilog = dmu_objset_zil(os); 754 bp = (blkptr_t *)&zilog->zl_header->zh_log; 755 756 /* 757 * Check the first block and determine if it's on a log device 758 * which may have been removed or faulted prior to loading this 759 * pool. If so, there's no point in checking the rest of the log 760 * as its content should have already been synced to the pool. 761 */ 762 if (!BP_IS_HOLE(bp)) { 763 vdev_t *vd; 764 boolean_t valid = B_TRUE; 765 766 spa_config_enter(os->os_spa, SCL_STATE, FTAG, RW_READER); 767 vd = vdev_lookup_top(os->os_spa, DVA_GET_VDEV(&bp->blk_dva[0])); 768 if (vd->vdev_islog && vdev_is_dead(vd)) 769 valid = vdev_log_state_valid(vd); 770 spa_config_exit(os->os_spa, SCL_STATE, FTAG); 771 772 if (!valid) 773 return (0); 774 } 775 776 /* 777 * Because tx == NULL, zil_claim_log_block() will not actually claim 778 * any blocks, but just determine whether it is possible to do so. 779 * In addition to checking the log chain, zil_claim_log_block() 780 * will invoke zio_claim() with a done func of spa_claim_notify(), 781 * which will update spa_max_claim_txg. See spa_load() for details. 782 */ 783 error = zil_parse(zilog, zil_claim_log_block, zil_claim_log_record, tx, 784 zilog->zl_header->zh_claim_txg ? -1ULL : spa_first_txg(os->os_spa)); 785 786 return ((error == ECKSUM || error == ENOENT) ? 0 : error); 787} 788 789static int 790zil_vdev_compare(const void *x1, const void *x2) 791{ 792 const uint64_t v1 = ((zil_vdev_node_t *)x1)->zv_vdev; 793 const uint64_t v2 = ((zil_vdev_node_t *)x2)->zv_vdev; 794 795 if (v1 < v2) 796 return (-1); 797 if (v1 > v2) 798 return (1); 799 800 return (0); 801} 802 803void 804zil_add_block(zilog_t *zilog, const blkptr_t *bp) 805{ 806 avl_tree_t *t = &zilog->zl_vdev_tree; 807 avl_index_t where; 808 zil_vdev_node_t *zv, zvsearch; 809 int ndvas = BP_GET_NDVAS(bp); 810 int i; 811 812 if (zfs_nocacheflush) 813 return; 814 815 ASSERT(zilog->zl_writer); 816 817 /* 818 * Even though we're zl_writer, we still need a lock because the 819 * zl_get_data() callbacks may have dmu_sync() done callbacks 820 * that will run concurrently. 821 */ 822 mutex_enter(&zilog->zl_vdev_lock); 823 for (i = 0; i < ndvas; i++) { 824 zvsearch.zv_vdev = DVA_GET_VDEV(&bp->blk_dva[i]); 825 if (avl_find(t, &zvsearch, &where) == NULL) { 826 zv = kmem_alloc(sizeof (*zv), KM_SLEEP); 827 zv->zv_vdev = zvsearch.zv_vdev; 828 avl_insert(t, zv, where); 829 } 830 } 831 mutex_exit(&zilog->zl_vdev_lock); 832} 833 834static void 835zil_flush_vdevs(zilog_t *zilog) 836{ 837 spa_t *spa = zilog->zl_spa; 838 avl_tree_t *t = &zilog->zl_vdev_tree; 839 void *cookie = NULL; 840 zil_vdev_node_t *zv; 841 zio_t *zio = NULL; 842 843 ASSERT(zilog->zl_writer); 844 845 /* 846 * We don't need zl_vdev_lock here because we're the zl_writer, 847 * and all zl_get_data() callbacks are done. 848 */ 849 if (avl_numnodes(t) == 0) 850 return; 851 852 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER); 853 854 while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) { 855 vdev_t *vd = vdev_lookup_top(spa, zv->zv_vdev); 856 if (vd != NULL && !vd->vdev_nowritecache) { 857 if (zio == NULL) 858 zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL); 859 zio_flush(zio, vd); 860 } 861 kmem_free(zv, sizeof (*zv)); 862 } 863 864 /* 865 * Wait for all the flushes to complete. Not all devices actually 866 * support the DKIOCFLUSHWRITECACHE ioctl, so it's OK if it fails. 867 */ 868 if (zio) 869 (void) zio_wait(zio); 870 871 spa_config_exit(spa, SCL_STATE, FTAG); 872} 873 874/* 875 * Function called when a log block write completes 876 */ 877static void 878zil_lwb_write_done(zio_t *zio) 879{ 880 lwb_t *lwb = zio->io_private; 881 zilog_t *zilog = lwb->lwb_zilog; 882 dmu_tx_t *tx = lwb->lwb_tx; 883 884 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 885 ASSERT(BP_GET_TYPE(zio->io_bp) == DMU_OT_INTENT_LOG); 886 ASSERT(BP_GET_LEVEL(zio->io_bp) == 0); 887 ASSERT(BP_GET_BYTEORDER(zio->io_bp) == ZFS_HOST_BYTEORDER); 888 ASSERT(!BP_IS_GANG(zio->io_bp)); 889 ASSERT(!BP_IS_HOLE(zio->io_bp)); 890 ASSERT(BP_GET_FILL(zio->io_bp) == 0); 891 892 /* 893 * Ensure the lwb buffer pointer is cleared before releasing 894 * the txg. If we have had an allocation failure and 895 * the txg is waiting to sync then we want want zil_sync() 896 * to remove the lwb so that it's not picked up as the next new 897 * one in zil_commit_writer(). zil_sync() will only remove 898 * the lwb if lwb_buf is null. 899 */ 900 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 901 mutex_enter(&zilog->zl_lock); 902 lwb->lwb_buf = NULL; 903 lwb->lwb_tx = NULL; 904 mutex_exit(&zilog->zl_lock); 905 906 /* 907 * Now that we've written this log block, we have a stable pointer 908 * to the next block in the chain, so it's OK to let the txg in 909 * which we allocated the next block sync. 910 */ 911 dmu_tx_commit(tx); 912} 913 914/* 915 * Initialize the io for a log block. 916 */ 917static void 918zil_lwb_write_init(zilog_t *zilog, lwb_t *lwb) 919{ 920 zbookmark_phys_t zb; 921 zio_priority_t prio; 922 923 SET_BOOKMARK(&zb, lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_OBJSET], 924 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, 925 lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_SEQ]); 926 927 if (zilog->zl_root_zio == NULL) { 928 zilog->zl_root_zio = zio_root(zilog->zl_spa, NULL, NULL, 929 ZIO_FLAG_CANFAIL); 930 } 931 if (lwb->lwb_zio == NULL) { 932 if (zilog->zl_cur_used <= zil_slog_limit || !lwb->lwb_slog) 933 prio = ZIO_PRIORITY_SYNC_WRITE; 934 else 935 prio = ZIO_PRIORITY_ASYNC_WRITE; 936 lwb->lwb_zio = zio_rewrite(zilog->zl_root_zio, zilog->zl_spa, 937 0, &lwb->lwb_blk, lwb->lwb_buf, BP_GET_LSIZE(&lwb->lwb_blk), 938 zil_lwb_write_done, lwb, prio, 939 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE, &zb); 940 } 941} 942 943/* 944 * Define a limited set of intent log block sizes. 945 * 946 * These must be a multiple of 4KB. Note only the amount used (again 947 * aligned to 4KB) actually gets written. However, we can't always just 948 * allocate SPA_OLD_MAXBLOCKSIZE as the slog space could be exhausted. 949 */ 950uint64_t zil_block_buckets[] = { 951 4096, /* non TX_WRITE */ 952 8192+4096, /* data base */ 953 32*1024 + 4096, /* NFS writes */ 954 UINT64_MAX 955}; 956 957/* 958 * Start a log block write and advance to the next log block. 959 * Calls are serialized. 960 */ 961static lwb_t * 962zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb, boolean_t last) 963{ 964 lwb_t *nlwb = NULL; 965 zil_chain_t *zilc; 966 spa_t *spa = zilog->zl_spa; 967 blkptr_t *bp; 968 dmu_tx_t *tx; 969 uint64_t txg; 970 uint64_t zil_blksz, wsz; 971 int i, error; 972 boolean_t slog; 973 974 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) { 975 zilc = (zil_chain_t *)lwb->lwb_buf; 976 bp = &zilc->zc_next_blk; 977 } else { 978 zilc = (zil_chain_t *)(lwb->lwb_buf + lwb->lwb_sz); 979 bp = &zilc->zc_next_blk; 980 } 981 982 ASSERT(lwb->lwb_nused <= lwb->lwb_sz); 983 984 /* 985 * Allocate the next block and save its address in this block 986 * before writing it in order to establish the log chain. 987 * Note that if the allocation of nlwb synced before we wrote 988 * the block that points at it (lwb), we'd leak it if we crashed. 989 * Therefore, we don't do dmu_tx_commit() until zil_lwb_write_done(). 990 * We dirty the dataset to ensure that zil_sync() will be called 991 * to clean up in the event of allocation failure or I/O failure. 992 */ 993 tx = dmu_tx_create(zilog->zl_os); 994 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 995 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 996 txg = dmu_tx_get_txg(tx); 997 998 lwb->lwb_tx = tx; 999 1000 /* 1001 * Log blocks are pre-allocated. Here we select the size of the next 1002 * block, based on size used in the last block. 1003 * - first find the smallest bucket that will fit the block from a 1004 * limited set of block sizes. This is because it's faster to write 1005 * blocks allocated from the same metaslab as they are adjacent or 1006 * close. 1007 * - next find the maximum from the new suggested size and an array of 1008 * previous sizes. This lessens a picket fence effect of wrongly 1009 * guesssing the size if we have a stream of say 2k, 64k, 2k, 64k 1010 * requests. 1011 * 1012 * Note we only write what is used, but we can't just allocate 1013 * the maximum block size because we can exhaust the available 1014 * pool log space. 1015 */ 1016 zil_blksz = zilog->zl_cur_used + sizeof (zil_chain_t); 1017 for (i = 0; zil_blksz > zil_block_buckets[i]; i++) 1018 continue; 1019 zil_blksz = zil_block_buckets[i]; 1020 if (zil_blksz == UINT64_MAX) 1021 zil_blksz = SPA_OLD_MAXBLOCKSIZE; 1022 zilog->zl_prev_blks[zilog->zl_prev_rotor] = zil_blksz; 1023 for (i = 0; i < ZIL_PREV_BLKS; i++) 1024 zil_blksz = MAX(zil_blksz, zilog->zl_prev_blks[i]); 1025 zilog->zl_prev_rotor = (zilog->zl_prev_rotor + 1) & (ZIL_PREV_BLKS - 1); 1026 1027 BP_ZERO(bp); 1028 /* pass the old blkptr in order to spread log blocks across devs */ 1029 error = zio_alloc_zil(spa, txg, bp, &lwb->lwb_blk, zil_blksz, &slog); 1030 if (error == 0) { 1031 ASSERT3U(bp->blk_birth, ==, txg); 1032 bp->blk_cksum = lwb->lwb_blk.blk_cksum; 1033 bp->blk_cksum.zc_word[ZIL_ZC_SEQ]++; 1034 1035 /* 1036 * Allocate a new log write buffer (lwb). 1037 */ 1038 nlwb = zil_alloc_lwb(zilog, bp, slog, txg); 1039 1040 /* Record the block for later vdev flushing */ 1041 zil_add_block(zilog, &lwb->lwb_blk); 1042 } 1043 1044 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) { 1045 /* For Slim ZIL only write what is used. */ 1046 wsz = P2ROUNDUP_TYPED(lwb->lwb_nused, ZIL_MIN_BLKSZ, uint64_t); 1047 ASSERT3U(wsz, <=, lwb->lwb_sz); 1048 zio_shrink(lwb->lwb_zio, wsz); 1049 1050 } else { 1051 wsz = lwb->lwb_sz; 1052 } 1053 1054 zilc->zc_pad = 0; 1055 zilc->zc_nused = lwb->lwb_nused; 1056 zilc->zc_eck.zec_cksum = lwb->lwb_blk.blk_cksum; 1057 1058 /* 1059 * clear unused data for security 1060 */ 1061 bzero(lwb->lwb_buf + lwb->lwb_nused, wsz - lwb->lwb_nused); 1062 1063 if (last) 1064 lwb->lwb_zio->io_pipeline &= ~ZIO_STAGE_ISSUE_ASYNC; 1065 zio_nowait(lwb->lwb_zio); /* Kick off the write for the old log block */ 1066 1067 /* 1068 * If there was an allocation failure then nlwb will be null which 1069 * forces a txg_wait_synced(). 1070 */ 1071 return (nlwb); 1072} 1073 1074static lwb_t * 1075zil_lwb_commit(zilog_t *zilog, itx_t *itx, lwb_t *lwb) 1076{ 1077 lr_t *lrcb, *lrc = &itx->itx_lr; /* common log record */ 1078 lr_write_t *lrwb, *lrw = (lr_write_t *)lrc; 1079 char *lr_buf; 1080 uint64_t txg = lrc->lrc_txg; 1081 uint64_t reclen = lrc->lrc_reclen; 1082 uint64_t dlen = 0; 1083 uint64_t dnow, lwb_sp; 1084 1085 if (lwb == NULL) 1086 return (NULL); 1087 1088 ASSERT(lwb->lwb_buf != NULL); 1089 1090 if (lrc->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY) 1091 dlen = P2ROUNDUP_TYPED( 1092 lrw->lr_length, sizeof (uint64_t), uint64_t); 1093 1094 zilog->zl_cur_used += (reclen + dlen); 1095 1096 zil_lwb_write_init(zilog, lwb); 1097 1098cont: 1099 /* 1100 * If this record won't fit in the current log block, start a new one. 1101 * For WR_NEED_COPY optimize layout for minimal number of chunks, but 1102 * try to keep wasted space withing reasonable range (12%). 1103 */ 1104 lwb_sp = lwb->lwb_sz - lwb->lwb_nused; 1105 if (reclen > lwb_sp || (reclen + dlen > lwb_sp && 1106 lwb_sp < ZIL_MAX_LOG_DATA / 8 && (dlen % ZIL_MAX_LOG_DATA == 0 || 1107 lwb_sp < reclen + dlen % ZIL_MAX_LOG_DATA))) { 1108 lwb = zil_lwb_write_start(zilog, lwb, B_FALSE); 1109 if (lwb == NULL) 1110 return (NULL); 1111 zil_lwb_write_init(zilog, lwb); 1112 ASSERT(LWB_EMPTY(lwb)); 1113 lwb_sp = lwb->lwb_sz - lwb->lwb_nused; 1114 ASSERT3U(reclen + MIN(dlen, sizeof(uint64_t)), <=, lwb_sp); 1115 } 1116 1117 dnow = MIN(dlen, lwb_sp - reclen); 1118 lr_buf = lwb->lwb_buf + lwb->lwb_nused; 1119 bcopy(lrc, lr_buf, reclen); 1120 lrcb = (lr_t *)lr_buf; 1121 lrwb = (lr_write_t *)lrcb; 1122 1123 /* 1124 * If it's a write, fetch the data or get its blkptr as appropriate. 1125 */ 1126 if (lrc->lrc_txtype == TX_WRITE) { 1127 if (txg > spa_freeze_txg(zilog->zl_spa)) 1128 txg_wait_synced(zilog->zl_dmu_pool, txg); 1129 if (itx->itx_wr_state != WR_COPIED) { 1130 char *dbuf; 1131 int error; 1132 1133 if (itx->itx_wr_state == WR_NEED_COPY) { 1134 dbuf = lr_buf + reclen; 1135 lrcb->lrc_reclen += dnow; 1136 if (lrwb->lr_length > dnow) 1137 lrwb->lr_length = dnow; 1138 lrw->lr_offset += dnow; 1139 lrw->lr_length -= dnow; 1140 } else { 1141 ASSERT(itx->itx_wr_state == WR_INDIRECT); 1142 dbuf = NULL; 1143 } 1144 error = zilog->zl_get_data( 1145 itx->itx_private, lrwb, dbuf, lwb->lwb_zio); 1146 if (error == EIO) { 1147 txg_wait_synced(zilog->zl_dmu_pool, txg); 1148 return (lwb); 1149 } 1150 if (error != 0) { 1151 ASSERT(error == ENOENT || error == EEXIST || 1152 error == EALREADY); 1153 return (lwb); 1154 } 1155 } 1156 } 1157 1158 /* 1159 * We're actually making an entry, so update lrc_seq to be the 1160 * log record sequence number. Note that this is generally not 1161 * equal to the itx sequence number because not all transactions 1162 * are synchronous, and sometimes spa_sync() gets there first. 1163 */ 1164 lrcb->lrc_seq = ++zilog->zl_lr_seq; /* we are single threaded */ 1165 lwb->lwb_nused += reclen + dnow; 1166 lwb->lwb_max_txg = MAX(lwb->lwb_max_txg, txg); 1167 ASSERT3U(lwb->lwb_nused, <=, lwb->lwb_sz); 1168 ASSERT0(P2PHASE(lwb->lwb_nused, sizeof (uint64_t))); 1169 1170 dlen -= dnow; 1171 if (dlen > 0) { 1172 zilog->zl_cur_used += reclen; 1173 goto cont; 1174 } 1175 1176 return (lwb); 1177} 1178 1179itx_t * 1180zil_itx_create(uint64_t txtype, size_t lrsize) 1181{ 1182 itx_t *itx; 1183 1184 lrsize = P2ROUNDUP_TYPED(lrsize, sizeof (uint64_t), size_t); 1185 1186 itx = kmem_alloc(offsetof(itx_t, itx_lr) + lrsize, KM_SLEEP); 1187 itx->itx_lr.lrc_txtype = txtype; 1188 itx->itx_lr.lrc_reclen = lrsize; 1189 itx->itx_lr.lrc_seq = 0; /* defensive */ 1190 itx->itx_sync = B_TRUE; /* default is synchronous */ 1191 1192 return (itx); 1193} 1194 1195void 1196zil_itx_destroy(itx_t *itx) 1197{ 1198 kmem_free(itx, offsetof(itx_t, itx_lr) + itx->itx_lr.lrc_reclen); 1199} 1200 1201/* 1202 * Free up the sync and async itxs. The itxs_t has already been detached 1203 * so no locks are needed. 1204 */ 1205static void 1206zil_itxg_clean(itxs_t *itxs) 1207{ 1208 itx_t *itx; 1209 list_t *list; 1210 avl_tree_t *t; 1211 void *cookie; 1212 itx_async_node_t *ian; 1213 1214 list = &itxs->i_sync_list; 1215 while ((itx = list_head(list)) != NULL) { 1216 list_remove(list, itx); 1217 kmem_free(itx, offsetof(itx_t, itx_lr) + 1218 itx->itx_lr.lrc_reclen); 1219 } 1220 1221 cookie = NULL; 1222 t = &itxs->i_async_tree; 1223 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) { 1224 list = &ian->ia_list; 1225 while ((itx = list_head(list)) != NULL) { 1226 list_remove(list, itx); 1227 kmem_free(itx, offsetof(itx_t, itx_lr) + 1228 itx->itx_lr.lrc_reclen); 1229 } 1230 list_destroy(list); 1231 kmem_free(ian, sizeof (itx_async_node_t)); 1232 } 1233 avl_destroy(t); 1234 1235 kmem_free(itxs, sizeof (itxs_t)); 1236} 1237 1238static int 1239zil_aitx_compare(const void *x1, const void *x2) 1240{ 1241 const uint64_t o1 = ((itx_async_node_t *)x1)->ia_foid; 1242 const uint64_t o2 = ((itx_async_node_t *)x2)->ia_foid; 1243 1244 if (o1 < o2) 1245 return (-1); 1246 if (o1 > o2) 1247 return (1); 1248 1249 return (0); 1250} 1251 1252/* 1253 * Remove all async itx with the given oid. 1254 */ 1255static void 1256zil_remove_async(zilog_t *zilog, uint64_t oid) 1257{ 1258 uint64_t otxg, txg; 1259 itx_async_node_t *ian; 1260 avl_tree_t *t; 1261 avl_index_t where; 1262 list_t clean_list; 1263 itx_t *itx; 1264 1265 ASSERT(oid != 0); 1266 list_create(&clean_list, sizeof (itx_t), offsetof(itx_t, itx_node)); 1267 1268 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1269 otxg = ZILTEST_TXG; 1270 else 1271 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1272 1273 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1274 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1275 1276 mutex_enter(&itxg->itxg_lock); 1277 if (itxg->itxg_txg != txg) { 1278 mutex_exit(&itxg->itxg_lock); 1279 continue; 1280 } 1281 1282 /* 1283 * Locate the object node and append its list. 1284 */ 1285 t = &itxg->itxg_itxs->i_async_tree; 1286 ian = avl_find(t, &oid, &where); 1287 if (ian != NULL) 1288 list_move_tail(&clean_list, &ian->ia_list); 1289 mutex_exit(&itxg->itxg_lock); 1290 } 1291 while ((itx = list_head(&clean_list)) != NULL) { 1292 list_remove(&clean_list, itx); 1293 kmem_free(itx, offsetof(itx_t, itx_lr) + 1294 itx->itx_lr.lrc_reclen); 1295 } 1296 list_destroy(&clean_list); 1297} 1298 1299void 1300zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx) 1301{ 1302 uint64_t txg; 1303 itxg_t *itxg; 1304 itxs_t *itxs, *clean = NULL; 1305 1306 /* 1307 * Object ids can be re-instantiated in the next txg so 1308 * remove any async transactions to avoid future leaks. 1309 * This can happen if a fsync occurs on the re-instantiated 1310 * object for a WR_INDIRECT or WR_NEED_COPY write, which gets 1311 * the new file data and flushes a write record for the old object. 1312 */ 1313 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_REMOVE) 1314 zil_remove_async(zilog, itx->itx_oid); 1315 1316 /* 1317 * Ensure the data of a renamed file is committed before the rename. 1318 */ 1319 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_RENAME) 1320 zil_async_to_sync(zilog, itx->itx_oid); 1321 1322 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) 1323 txg = ZILTEST_TXG; 1324 else 1325 txg = dmu_tx_get_txg(tx); 1326 1327 itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1328 mutex_enter(&itxg->itxg_lock); 1329 itxs = itxg->itxg_itxs; 1330 if (itxg->itxg_txg != txg) { 1331 if (itxs != NULL) { 1332 /* 1333 * The zil_clean callback hasn't got around to cleaning 1334 * this itxg. Save the itxs for release below. 1335 * This should be rare. 1336 */ 1337 clean = itxg->itxg_itxs; 1338 } 1339 itxg->itxg_txg = txg; 1340 itxs = itxg->itxg_itxs = kmem_zalloc(sizeof (itxs_t), KM_SLEEP); 1341 1342 list_create(&itxs->i_sync_list, sizeof (itx_t), 1343 offsetof(itx_t, itx_node)); 1344 avl_create(&itxs->i_async_tree, zil_aitx_compare, 1345 sizeof (itx_async_node_t), 1346 offsetof(itx_async_node_t, ia_node)); 1347 } 1348 if (itx->itx_sync) { 1349 list_insert_tail(&itxs->i_sync_list, itx); 1350 } else { 1351 avl_tree_t *t = &itxs->i_async_tree; 1352 uint64_t foid = ((lr_ooo_t *)&itx->itx_lr)->lr_foid; 1353 itx_async_node_t *ian; 1354 avl_index_t where; 1355 1356 ian = avl_find(t, &foid, &where); 1357 if (ian == NULL) { 1358 ian = kmem_alloc(sizeof (itx_async_node_t), KM_SLEEP); 1359 list_create(&ian->ia_list, sizeof (itx_t), 1360 offsetof(itx_t, itx_node)); 1361 ian->ia_foid = foid; 1362 avl_insert(t, ian, where); 1363 } 1364 list_insert_tail(&ian->ia_list, itx); 1365 } 1366 1367 itx->itx_lr.lrc_txg = dmu_tx_get_txg(tx); 1368 zilog_dirty(zilog, txg); 1369 mutex_exit(&itxg->itxg_lock); 1370 1371 /* Release the old itxs now we've dropped the lock */ 1372 if (clean != NULL) 1373 zil_itxg_clean(clean); 1374} 1375 1376/* 1377 * If there are any in-memory intent log transactions which have now been 1378 * synced then start up a taskq to free them. We should only do this after we 1379 * have written out the uberblocks (i.e. txg has been comitted) so that 1380 * don't inadvertently clean out in-memory log records that would be required 1381 * by zil_commit(). 1382 */ 1383void 1384zil_clean(zilog_t *zilog, uint64_t synced_txg) 1385{ 1386 itxg_t *itxg = &zilog->zl_itxg[synced_txg & TXG_MASK]; 1387 itxs_t *clean_me; 1388 1389 mutex_enter(&itxg->itxg_lock); 1390 if (itxg->itxg_itxs == NULL || itxg->itxg_txg == ZILTEST_TXG) { 1391 mutex_exit(&itxg->itxg_lock); 1392 return; 1393 } 1394 ASSERT3U(itxg->itxg_txg, <=, synced_txg); 1395 ASSERT(itxg->itxg_txg != 0); 1396 ASSERT(zilog->zl_clean_taskq != NULL); 1397 clean_me = itxg->itxg_itxs; 1398 itxg->itxg_itxs = NULL; 1399 itxg->itxg_txg = 0; 1400 mutex_exit(&itxg->itxg_lock); 1401 /* 1402 * Preferably start a task queue to free up the old itxs but 1403 * if taskq_dispatch can't allocate resources to do that then 1404 * free it in-line. This should be rare. Note, using TQ_SLEEP 1405 * created a bad performance problem. 1406 */ 1407 if (taskq_dispatch(zilog->zl_clean_taskq, 1408 (void (*)(void *))zil_itxg_clean, clean_me, TQ_NOSLEEP) == 0) 1409 zil_itxg_clean(clean_me); 1410} 1411 1412/* 1413 * Get the list of itxs to commit into zl_itx_commit_list. 1414 */ 1415static void 1416zil_get_commit_list(zilog_t *zilog) 1417{ 1418 uint64_t otxg, txg; 1419 list_t *commit_list = &zilog->zl_itx_commit_list; 1420 1421 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1422 otxg = ZILTEST_TXG; 1423 else 1424 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1425 1426 /* 1427 * This is inherently racy, since there is nothing to prevent 1428 * the last synced txg from changing. That's okay since we'll 1429 * only commit things in the future. 1430 */ 1431 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1432 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1433 1434 mutex_enter(&itxg->itxg_lock); 1435 if (itxg->itxg_txg != txg) { 1436 mutex_exit(&itxg->itxg_lock); 1437 continue; 1438 } 1439 1440 /* 1441 * If we're adding itx records to the zl_itx_commit_list, 1442 * then the zil better be dirty in this "txg". We can assert 1443 * that here since we're holding the itxg_lock which will 1444 * prevent spa_sync from cleaning it. Once we add the itxs 1445 * to the zl_itx_commit_list we must commit it to disk even 1446 * if it's unnecessary (i.e. the txg was synced). 1447 */ 1448 ASSERT(zilog_is_dirty_in_txg(zilog, txg) || 1449 spa_freeze_txg(zilog->zl_spa) != UINT64_MAX); 1450 list_move_tail(commit_list, &itxg->itxg_itxs->i_sync_list); 1451 1452 mutex_exit(&itxg->itxg_lock); 1453 } 1454} 1455 1456/* 1457 * Move the async itxs for a specified object to commit into sync lists. 1458 */ 1459void 1460zil_async_to_sync(zilog_t *zilog, uint64_t foid) 1461{ 1462 uint64_t otxg, txg; 1463 itx_async_node_t *ian; 1464 avl_tree_t *t; 1465 avl_index_t where; 1466 1467 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1468 otxg = ZILTEST_TXG; 1469 else 1470 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1471 1472 /* 1473 * This is inherently racy, since there is nothing to prevent 1474 * the last synced txg from changing. 1475 */ 1476 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1477 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1478 1479 mutex_enter(&itxg->itxg_lock); 1480 if (itxg->itxg_txg != txg) { 1481 mutex_exit(&itxg->itxg_lock); 1482 continue; 1483 } 1484 1485 /* 1486 * If a foid is specified then find that node and append its 1487 * list. Otherwise walk the tree appending all the lists 1488 * to the sync list. We add to the end rather than the 1489 * beginning to ensure the create has happened. 1490 */ 1491 t = &itxg->itxg_itxs->i_async_tree; 1492 if (foid != 0) { 1493 ian = avl_find(t, &foid, &where); 1494 if (ian != NULL) { 1495 list_move_tail(&itxg->itxg_itxs->i_sync_list, 1496 &ian->ia_list); 1497 } 1498 } else { 1499 void *cookie = NULL; 1500 1501 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) { 1502 list_move_tail(&itxg->itxg_itxs->i_sync_list, 1503 &ian->ia_list); 1504 list_destroy(&ian->ia_list); 1505 kmem_free(ian, sizeof (itx_async_node_t)); 1506 } 1507 } 1508 mutex_exit(&itxg->itxg_lock); 1509 } 1510} 1511 1512static void 1513zil_commit_writer(zilog_t *zilog) 1514{ 1515 uint64_t txg; 1516 itx_t *itx; 1517 lwb_t *lwb; 1518 spa_t *spa = zilog->zl_spa; 1519 int error = 0; 1520 1521 ASSERT(zilog->zl_root_zio == NULL); 1522 1523 mutex_exit(&zilog->zl_lock); 1524 1525 zil_get_commit_list(zilog); 1526 1527 /* 1528 * Return if there's nothing to commit before we dirty the fs by 1529 * calling zil_create(). 1530 */ 1531 if (list_head(&zilog->zl_itx_commit_list) == NULL) { 1532 mutex_enter(&zilog->zl_lock); 1533 return; 1534 } 1535 1536 if (zilog->zl_suspend) { 1537 lwb = NULL; 1538 } else { 1539 lwb = list_tail(&zilog->zl_lwb_list); 1540 if (lwb == NULL) 1541 lwb = zil_create(zilog); 1542 } 1543 1544 DTRACE_PROBE1(zil__cw1, zilog_t *, zilog); 1545 while (itx = list_head(&zilog->zl_itx_commit_list)) { 1546 txg = itx->itx_lr.lrc_txg; 1547 ASSERT3U(txg, !=, 0); 1548 1549 /* 1550 * This is inherently racy and may result in us writing 1551 * out a log block for a txg that was just synced. This is 1552 * ok since we'll end cleaning up that log block the next 1553 * time we call zil_sync(). 1554 */ 1555 if (txg > spa_last_synced_txg(spa) || txg > spa_freeze_txg(spa)) 1556 lwb = zil_lwb_commit(zilog, itx, lwb); 1557 list_remove(&zilog->zl_itx_commit_list, itx); 1558 kmem_free(itx, offsetof(itx_t, itx_lr) 1559 + itx->itx_lr.lrc_reclen); 1560 } 1561 DTRACE_PROBE1(zil__cw2, zilog_t *, zilog); 1562 1563 /* write the last block out */ 1564 if (lwb != NULL && lwb->lwb_zio != NULL) 1565 lwb = zil_lwb_write_start(zilog, lwb, B_TRUE); 1566 1567 zilog->zl_cur_used = 0; 1568 1569 /* 1570 * Wait if necessary for the log blocks to be on stable storage. 1571 */ 1572 if (zilog->zl_root_zio) { 1573 error = zio_wait(zilog->zl_root_zio); 1574 zilog->zl_root_zio = NULL; 1575 zil_flush_vdevs(zilog); 1576 } 1577 1578 if (error || lwb == NULL) 1579 txg_wait_synced(zilog->zl_dmu_pool, 0); 1580 1581 mutex_enter(&zilog->zl_lock); 1582 1583 /* 1584 * Remember the highest committed log sequence number for ztest. 1585 * We only update this value when all the log writes succeeded, 1586 * because ztest wants to ASSERT that it got the whole log chain. 1587 */ 1588 if (error == 0 && lwb != NULL) 1589 zilog->zl_commit_lr_seq = zilog->zl_lr_seq; 1590} 1591 1592/* 1593 * Commit zfs transactions to stable storage. 1594 * If foid is 0 push out all transactions, otherwise push only those 1595 * for that object or might reference that object. 1596 * 1597 * itxs are committed in batches. In a heavily stressed zil there will be 1598 * a commit writer thread who is writing out a bunch of itxs to the log 1599 * for a set of committing threads (cthreads) in the same batch as the writer. 1600 * Those cthreads are all waiting on the same cv for that batch. 1601 * 1602 * There will also be a different and growing batch of threads that are 1603 * waiting to commit (qthreads). When the committing batch completes 1604 * a transition occurs such that the cthreads exit and the qthreads become 1605 * cthreads. One of the new cthreads becomes the writer thread for the 1606 * batch. Any new threads arriving become new qthreads. 1607 * 1608 * Only 2 condition variables are needed and there's no transition 1609 * between the two cvs needed. They just flip-flop between qthreads 1610 * and cthreads. 1611 * 1612 * Using this scheme we can efficiently wakeup up only those threads 1613 * that have been committed. 1614 */ 1615void 1616zil_commit(zilog_t *zilog, uint64_t foid) 1617{ 1618 uint64_t mybatch; 1619 1620 if (zilog->zl_sync == ZFS_SYNC_DISABLED) 1621 return; 1622 1623 /* move the async itxs for the foid to the sync queues */ 1624 zil_async_to_sync(zilog, foid); 1625 1626 mutex_enter(&zilog->zl_lock); 1627 mybatch = zilog->zl_next_batch; 1628 while (zilog->zl_writer) { 1629 cv_wait(&zilog->zl_cv_batch[mybatch & 1], &zilog->zl_lock); 1630 if (mybatch <= zilog->zl_com_batch) { 1631 mutex_exit(&zilog->zl_lock); 1632 return; 1633 } 1634 } 1635 1636 zilog->zl_next_batch++; 1637 zilog->zl_writer = B_TRUE; 1638 zil_commit_writer(zilog); 1639 zilog->zl_com_batch = mybatch; 1640 zilog->zl_writer = B_FALSE; 1641 mutex_exit(&zilog->zl_lock); 1642 1643 /* wake up one thread to become the next writer */ 1644 cv_signal(&zilog->zl_cv_batch[(mybatch+1) & 1]); 1645 1646 /* wake up all threads waiting for this batch to be committed */ 1647 cv_broadcast(&zilog->zl_cv_batch[mybatch & 1]); 1648} 1649 1650/* 1651 * Called in syncing context to free committed log blocks and update log header. 1652 */ 1653void 1654zil_sync(zilog_t *zilog, dmu_tx_t *tx) 1655{ 1656 zil_header_t *zh = zil_header_in_syncing_context(zilog); 1657 uint64_t txg = dmu_tx_get_txg(tx); 1658 spa_t *spa = zilog->zl_spa; 1659 uint64_t *replayed_seq = &zilog->zl_replayed_seq[txg & TXG_MASK]; 1660 lwb_t *lwb; 1661 1662 /* 1663 * We don't zero out zl_destroy_txg, so make sure we don't try 1664 * to destroy it twice. 1665 */ 1666 if (spa_sync_pass(spa) != 1) 1667 return; 1668 1669 mutex_enter(&zilog->zl_lock); 1670 1671 ASSERT(zilog->zl_stop_sync == 0); 1672 1673 if (*replayed_seq != 0) { 1674 ASSERT(zh->zh_replay_seq < *replayed_seq); 1675 zh->zh_replay_seq = *replayed_seq; 1676 *replayed_seq = 0; 1677 } 1678 1679 if (zilog->zl_destroy_txg == txg) { 1680 blkptr_t blk = zh->zh_log; 1681 1682 ASSERT(list_head(&zilog->zl_lwb_list) == NULL); 1683 1684 bzero(zh, sizeof (zil_header_t)); 1685 bzero(zilog->zl_replayed_seq, sizeof (zilog->zl_replayed_seq)); 1686 1687 if (zilog->zl_keep_first) { 1688 /* 1689 * If this block was part of log chain that couldn't 1690 * be claimed because a device was missing during 1691 * zil_claim(), but that device later returns, 1692 * then this block could erroneously appear valid. 1693 * To guard against this, assign a new GUID to the new 1694 * log chain so it doesn't matter what blk points to. 1695 */ 1696 zil_init_log_chain(zilog, &blk); 1697 zh->zh_log = blk; 1698 } 1699 } 1700 1701 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { 1702 zh->zh_log = lwb->lwb_blk; 1703 if (lwb->lwb_buf != NULL || lwb->lwb_max_txg > txg) 1704 break; 1705 list_remove(&zilog->zl_lwb_list, lwb); 1706 zio_free_zil(spa, txg, &lwb->lwb_blk); 1707 kmem_cache_free(zil_lwb_cache, lwb); 1708 1709 /* 1710 * If we don't have anything left in the lwb list then 1711 * we've had an allocation failure and we need to zero 1712 * out the zil_header blkptr so that we don't end 1713 * up freeing the same block twice. 1714 */ 1715 if (list_head(&zilog->zl_lwb_list) == NULL) 1716 BP_ZERO(&zh->zh_log); 1717 } 1718 mutex_exit(&zilog->zl_lock); 1719} 1720 1721void 1722zil_init(void) 1723{ 1724 zil_lwb_cache = kmem_cache_create("zil_lwb_cache", 1725 sizeof (struct lwb), 0, NULL, NULL, NULL, NULL, NULL, 0); 1726} 1727 1728void 1729zil_fini(void) 1730{ 1731 kmem_cache_destroy(zil_lwb_cache); 1732} 1733 1734void 1735zil_set_sync(zilog_t *zilog, uint64_t sync) 1736{ 1737 zilog->zl_sync = sync; 1738} 1739 1740void 1741zil_set_logbias(zilog_t *zilog, uint64_t logbias) 1742{ 1743 zilog->zl_logbias = logbias; 1744} 1745 1746zilog_t * 1747zil_alloc(objset_t *os, zil_header_t *zh_phys) 1748{ 1749 zilog_t *zilog; 1750 1751 zilog = kmem_zalloc(sizeof (zilog_t), KM_SLEEP); 1752 1753 zilog->zl_header = zh_phys; 1754 zilog->zl_os = os; 1755 zilog->zl_spa = dmu_objset_spa(os); 1756 zilog->zl_dmu_pool = dmu_objset_pool(os); 1757 zilog->zl_destroy_txg = TXG_INITIAL - 1; 1758 zilog->zl_logbias = dmu_objset_logbias(os); 1759 zilog->zl_sync = dmu_objset_syncprop(os); 1760 zilog->zl_next_batch = 1; 1761 1762 mutex_init(&zilog->zl_lock, NULL, MUTEX_DEFAULT, NULL); 1763 1764 for (int i = 0; i < TXG_SIZE; i++) { 1765 mutex_init(&zilog->zl_itxg[i].itxg_lock, NULL, 1766 MUTEX_DEFAULT, NULL); 1767 } 1768 1769 list_create(&zilog->zl_lwb_list, sizeof (lwb_t), 1770 offsetof(lwb_t, lwb_node)); 1771 1772 list_create(&zilog->zl_itx_commit_list, sizeof (itx_t), 1773 offsetof(itx_t, itx_node)); 1774 1775 mutex_init(&zilog->zl_vdev_lock, NULL, MUTEX_DEFAULT, NULL); 1776 1777 avl_create(&zilog->zl_vdev_tree, zil_vdev_compare, 1778 sizeof (zil_vdev_node_t), offsetof(zil_vdev_node_t, zv_node)); 1779 1780 cv_init(&zilog->zl_cv_writer, NULL, CV_DEFAULT, NULL); 1781 cv_init(&zilog->zl_cv_suspend, NULL, CV_DEFAULT, NULL); 1782 cv_init(&zilog->zl_cv_batch[0], NULL, CV_DEFAULT, NULL); 1783 cv_init(&zilog->zl_cv_batch[1], NULL, CV_DEFAULT, NULL); 1784 1785 return (zilog); 1786} 1787 1788void 1789zil_free(zilog_t *zilog) 1790{ 1791 zilog->zl_stop_sync = 1; 1792 1793 ASSERT0(zilog->zl_suspend); 1794 ASSERT0(zilog->zl_suspending); 1795 1796 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 1797 list_destroy(&zilog->zl_lwb_list); 1798 1799 avl_destroy(&zilog->zl_vdev_tree); 1800 mutex_destroy(&zilog->zl_vdev_lock); 1801 1802 ASSERT(list_is_empty(&zilog->zl_itx_commit_list)); 1803 list_destroy(&zilog->zl_itx_commit_list); 1804 1805 for (int i = 0; i < TXG_SIZE; i++) { 1806 /* 1807 * It's possible for an itx to be generated that doesn't dirty 1808 * a txg (e.g. ztest TX_TRUNCATE). So there's no zil_clean() 1809 * callback to remove the entry. We remove those here. 1810 * 1811 * Also free up the ziltest itxs. 1812 */ 1813 if (zilog->zl_itxg[i].itxg_itxs) 1814 zil_itxg_clean(zilog->zl_itxg[i].itxg_itxs); 1815 mutex_destroy(&zilog->zl_itxg[i].itxg_lock); 1816 } 1817 1818 mutex_destroy(&zilog->zl_lock); 1819 1820 cv_destroy(&zilog->zl_cv_writer); 1821 cv_destroy(&zilog->zl_cv_suspend); 1822 cv_destroy(&zilog->zl_cv_batch[0]); 1823 cv_destroy(&zilog->zl_cv_batch[1]); 1824 1825 kmem_free(zilog, sizeof (zilog_t)); 1826} 1827 1828/* 1829 * Open an intent log. 1830 */ 1831zilog_t * 1832zil_open(objset_t *os, zil_get_data_t *get_data) 1833{ 1834 zilog_t *zilog = dmu_objset_zil(os); 1835 1836 ASSERT(zilog->zl_clean_taskq == NULL); 1837 ASSERT(zilog->zl_get_data == NULL); 1838 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 1839 1840 zilog->zl_get_data = get_data; 1841 zilog->zl_clean_taskq = taskq_create("zil_clean", 1, minclsyspri, 1842 2, 2, TASKQ_PREPOPULATE); 1843 1844 return (zilog); 1845} 1846 1847/* 1848 * Close an intent log. 1849 */ 1850void 1851zil_close(zilog_t *zilog) 1852{ 1853 lwb_t *lwb; 1854 uint64_t txg = 0; 1855 1856 zil_commit(zilog, 0); /* commit all itx */ 1857 1858 /* 1859 * The lwb_max_txg for the stubby lwb will reflect the last activity 1860 * for the zil. After a txg_wait_synced() on the txg we know all the 1861 * callbacks have occurred that may clean the zil. Only then can we 1862 * destroy the zl_clean_taskq. 1863 */ 1864 mutex_enter(&zilog->zl_lock); 1865 lwb = list_tail(&zilog->zl_lwb_list); 1866 if (lwb != NULL) 1867 txg = lwb->lwb_max_txg; 1868 mutex_exit(&zilog->zl_lock); 1869 if (txg) 1870 txg_wait_synced(zilog->zl_dmu_pool, txg); 1871 1872 if (zilog_is_dirty(zilog)) 1873 zfs_dbgmsg("zil (%p) is dirty, txg %llu", zilog, txg); 1874 VERIFY(!zilog_is_dirty(zilog)); 1875 1876 taskq_destroy(zilog->zl_clean_taskq); 1877 zilog->zl_clean_taskq = NULL; 1878 zilog->zl_get_data = NULL; 1879 1880 /* 1881 * We should have only one LWB left on the list; remove it now. 1882 */ 1883 mutex_enter(&zilog->zl_lock); 1884 lwb = list_head(&zilog->zl_lwb_list); 1885 if (lwb != NULL) { 1886 ASSERT(lwb == list_tail(&zilog->zl_lwb_list)); 1887 list_remove(&zilog->zl_lwb_list, lwb); 1888 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 1889 kmem_cache_free(zil_lwb_cache, lwb); 1890 } 1891 mutex_exit(&zilog->zl_lock); 1892} 1893 1894static char *suspend_tag = "zil suspending"; 1895 1896/* 1897 * Suspend an intent log. While in suspended mode, we still honor 1898 * synchronous semantics, but we rely on txg_wait_synced() to do it. 1899 * On old version pools, we suspend the log briefly when taking a 1900 * snapshot so that it will have an empty intent log. 1901 * 1902 * Long holds are not really intended to be used the way we do here -- 1903 * held for such a short time. A concurrent caller of dsl_dataset_long_held() 1904 * could fail. Therefore we take pains to only put a long hold if it is 1905 * actually necessary. Fortunately, it will only be necessary if the 1906 * objset is currently mounted (or the ZVOL equivalent). In that case it 1907 * will already have a long hold, so we are not really making things any worse. 1908 * 1909 * Ideally, we would locate the existing long-holder (i.e. the zfsvfs_t or 1910 * zvol_state_t), and use their mechanism to prevent their hold from being 1911 * dropped (e.g. VFS_HOLD()). However, that would be even more pain for 1912 * very little gain. 1913 * 1914 * if cookiep == NULL, this does both the suspend & resume. 1915 * Otherwise, it returns with the dataset "long held", and the cookie 1916 * should be passed into zil_resume(). 1917 */ 1918int 1919zil_suspend(const char *osname, void **cookiep) 1920{ 1921 objset_t *os; 1922 zilog_t *zilog; 1923 const zil_header_t *zh; 1924 int error; 1925 1926 error = dmu_objset_hold(osname, suspend_tag, &os); 1927 if (error != 0) 1928 return (error); 1929 zilog = dmu_objset_zil(os); 1930 1931 mutex_enter(&zilog->zl_lock); 1932 zh = zilog->zl_header; 1933 1934 if (zh->zh_flags & ZIL_REPLAY_NEEDED) { /* unplayed log */ 1935 mutex_exit(&zilog->zl_lock); 1936 dmu_objset_rele(os, suspend_tag); 1937 return (SET_ERROR(EBUSY)); 1938 } 1939 1940 /* 1941 * Don't put a long hold in the cases where we can avoid it. This 1942 * is when there is no cookie so we are doing a suspend & resume 1943 * (i.e. called from zil_vdev_offline()), and there's nothing to do 1944 * for the suspend because it's already suspended, or there's no ZIL. 1945 */ 1946 if (cookiep == NULL && !zilog->zl_suspending && 1947 (zilog->zl_suspend > 0 || BP_IS_HOLE(&zh->zh_log))) { 1948 mutex_exit(&zilog->zl_lock); 1949 dmu_objset_rele(os, suspend_tag); 1950 return (0); 1951 } 1952 1953 dsl_dataset_long_hold(dmu_objset_ds(os), suspend_tag); 1954 dsl_pool_rele(dmu_objset_pool(os), suspend_tag); 1955 1956 zilog->zl_suspend++; 1957 1958 if (zilog->zl_suspend > 1) { 1959 /* 1960 * Someone else is already suspending it. 1961 * Just wait for them to finish. 1962 */ 1963 1964 while (zilog->zl_suspending) 1965 cv_wait(&zilog->zl_cv_suspend, &zilog->zl_lock); 1966 mutex_exit(&zilog->zl_lock); 1967 1968 if (cookiep == NULL) 1969 zil_resume(os); 1970 else 1971 *cookiep = os; 1972 return (0); 1973 } 1974 1975 /* 1976 * If there is no pointer to an on-disk block, this ZIL must not 1977 * be active (e.g. filesystem not mounted), so there's nothing 1978 * to clean up. 1979 */ 1980 if (BP_IS_HOLE(&zh->zh_log)) { 1981 ASSERT(cookiep != NULL); /* fast path already handled */ 1982 1983 *cookiep = os; 1984 mutex_exit(&zilog->zl_lock); 1985 return (0); 1986 } 1987 1988 zilog->zl_suspending = B_TRUE; 1989 mutex_exit(&zilog->zl_lock); 1990 1991 zil_commit(zilog, 0); 1992 1993 zil_destroy(zilog, B_FALSE); 1994 1995 mutex_enter(&zilog->zl_lock); 1996 zilog->zl_suspending = B_FALSE; 1997 cv_broadcast(&zilog->zl_cv_suspend); 1998 mutex_exit(&zilog->zl_lock); 1999 2000 if (cookiep == NULL) 2001 zil_resume(os); 2002 else 2003 *cookiep = os; 2004 return (0); 2005} 2006 2007void 2008zil_resume(void *cookie) 2009{ 2010 objset_t *os = cookie; 2011 zilog_t *zilog = dmu_objset_zil(os); 2012 2013 mutex_enter(&zilog->zl_lock); 2014 ASSERT(zilog->zl_suspend != 0); 2015 zilog->zl_suspend--; 2016 mutex_exit(&zilog->zl_lock); 2017 dsl_dataset_long_rele(dmu_objset_ds(os), suspend_tag); 2018 dsl_dataset_rele(dmu_objset_ds(os), suspend_tag); 2019} 2020 2021typedef struct zil_replay_arg { 2022 zil_replay_func_t **zr_replay; 2023 void *zr_arg; 2024 boolean_t zr_byteswap; 2025 char *zr_lr; 2026} zil_replay_arg_t; 2027 2028static int 2029zil_replay_error(zilog_t *zilog, lr_t *lr, int error) 2030{ 2031 char name[ZFS_MAX_DATASET_NAME_LEN]; 2032 2033 zilog->zl_replaying_seq--; /* didn't actually replay this one */ 2034 2035 dmu_objset_name(zilog->zl_os, name); 2036 2037 cmn_err(CE_WARN, "ZFS replay transaction error %d, " 2038 "dataset %s, seq 0x%llx, txtype %llu %s\n", error, name, 2039 (u_longlong_t)lr->lrc_seq, 2040 (u_longlong_t)(lr->lrc_txtype & ~TX_CI), 2041 (lr->lrc_txtype & TX_CI) ? "CI" : ""); 2042 2043 return (error); 2044} 2045 2046static int 2047zil_replay_log_record(zilog_t *zilog, lr_t *lr, void *zra, uint64_t claim_txg) 2048{ 2049 zil_replay_arg_t *zr = zra; 2050 const zil_header_t *zh = zilog->zl_header; 2051 uint64_t reclen = lr->lrc_reclen; 2052 uint64_t txtype = lr->lrc_txtype; 2053 int error = 0; 2054 2055 zilog->zl_replaying_seq = lr->lrc_seq; 2056 2057 if (lr->lrc_seq <= zh->zh_replay_seq) /* already replayed */ 2058 return (0); 2059 2060 if (lr->lrc_txg < claim_txg) /* already committed */ 2061 return (0); 2062 2063 /* Strip case-insensitive bit, still present in log record */ 2064 txtype &= ~TX_CI; 2065 2066 if (txtype == 0 || txtype >= TX_MAX_TYPE) 2067 return (zil_replay_error(zilog, lr, EINVAL)); 2068 2069 /* 2070 * If this record type can be logged out of order, the object 2071 * (lr_foid) may no longer exist. That's legitimate, not an error. 2072 */ 2073 if (TX_OOO(txtype)) { 2074 error = dmu_object_info(zilog->zl_os, 2075 ((lr_ooo_t *)lr)->lr_foid, NULL); 2076 if (error == ENOENT || error == EEXIST) 2077 return (0); 2078 } 2079 2080 /* 2081 * Make a copy of the data so we can revise and extend it. 2082 */ 2083 bcopy(lr, zr->zr_lr, reclen); 2084 2085 /* 2086 * If this is a TX_WRITE with a blkptr, suck in the data. 2087 */ 2088 if (txtype == TX_WRITE && reclen == sizeof (lr_write_t)) { 2089 error = zil_read_log_data(zilog, (lr_write_t *)lr, 2090 zr->zr_lr + reclen); 2091 if (error != 0) 2092 return (zil_replay_error(zilog, lr, error)); 2093 } 2094 2095 /* 2096 * The log block containing this lr may have been byteswapped 2097 * so that we can easily examine common fields like lrc_txtype. 2098 * However, the log is a mix of different record types, and only the 2099 * replay vectors know how to byteswap their records. Therefore, if 2100 * the lr was byteswapped, undo it before invoking the replay vector. 2101 */ 2102 if (zr->zr_byteswap) 2103 byteswap_uint64_array(zr->zr_lr, reclen); 2104 2105 /* 2106 * We must now do two things atomically: replay this log record, 2107 * and update the log header sequence number to reflect the fact that 2108 * we did so. At the end of each replay function the sequence number 2109 * is updated if we are in replay mode. 2110 */ 2111 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, zr->zr_byteswap); 2112 if (error != 0) { 2113 /* 2114 * The DMU's dnode layer doesn't see removes until the txg 2115 * commits, so a subsequent claim can spuriously fail with 2116 * EEXIST. So if we receive any error we try syncing out 2117 * any removes then retry the transaction. Note that we 2118 * specify B_FALSE for byteswap now, so we don't do it twice. 2119 */ 2120 txg_wait_synced(spa_get_dsl(zilog->zl_spa), 0); 2121 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, B_FALSE); 2122 if (error != 0) 2123 return (zil_replay_error(zilog, lr, error)); 2124 } 2125 return (0); 2126} 2127 2128/* ARGSUSED */ 2129static int 2130zil_incr_blks(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg) 2131{ 2132 zilog->zl_replay_blks++; 2133 2134 return (0); 2135} 2136 2137/* 2138 * If this dataset has a non-empty intent log, replay it and destroy it. 2139 */ 2140void 2141zil_replay(objset_t *os, void *arg, zil_replay_func_t *replay_func[TX_MAX_TYPE]) 2142{ 2143 zilog_t *zilog = dmu_objset_zil(os); 2144 const zil_header_t *zh = zilog->zl_header; 2145 zil_replay_arg_t zr; 2146 2147 if ((zh->zh_flags & ZIL_REPLAY_NEEDED) == 0) { 2148 zil_destroy(zilog, B_TRUE); 2149 return; 2150 } 2151 2152 zr.zr_replay = replay_func; 2153 zr.zr_arg = arg; 2154 zr.zr_byteswap = BP_SHOULD_BYTESWAP(&zh->zh_log); 2155 zr.zr_lr = kmem_alloc(2 * SPA_MAXBLOCKSIZE, KM_SLEEP); 2156 2157 /* 2158 * Wait for in-progress removes to sync before starting replay. 2159 */ 2160 txg_wait_synced(zilog->zl_dmu_pool, 0); 2161 2162 zilog->zl_replay = B_TRUE; 2163 zilog->zl_replay_time = ddi_get_lbolt(); 2164 ASSERT(zilog->zl_replay_blks == 0); 2165 (void) zil_parse(zilog, zil_incr_blks, zil_replay_log_record, &zr, 2166 zh->zh_claim_txg); 2167 kmem_free(zr.zr_lr, 2 * SPA_MAXBLOCKSIZE); 2168 2169 zil_destroy(zilog, B_FALSE); 2170 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 2171 zilog->zl_replay = B_FALSE; 2172} 2173 2174boolean_t 2175zil_replaying(zilog_t *zilog, dmu_tx_t *tx) 2176{ 2177 if (zilog->zl_sync == ZFS_SYNC_DISABLED) 2178 return (B_TRUE); 2179 2180 if (zilog->zl_replay) { 2181 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 2182 zilog->zl_replayed_seq[dmu_tx_get_txg(tx) & TXG_MASK] = 2183 zilog->zl_replaying_seq; 2184 return (B_TRUE); 2185 } 2186 2187 return (B_FALSE); 2188} 2189 2190/* ARGSUSED */ 2191int 2192zil_vdev_offline(const char *osname, void *arg) 2193{ 2194 int error; 2195 2196 error = zil_suspend(osname, NULL); 2197 if (error != 0) 2198 return (SET_ERROR(EEXIST)); 2199 return (0); 2200} 2201