zil.c revision 248571
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) 2012 by Delphix. All rights reserved. 24 */ 25 26/* Portions Copyright 2010 Robert Milkowski */ 27 28#include <sys/zfs_context.h> 29#include <sys/spa.h> 30#include <sys/dmu.h> 31#include <sys/zap.h> 32#include <sys/arc.h> 33#include <sys/stat.h> 34#include <sys/resource.h> 35#include <sys/zil.h> 36#include <sys/zil_impl.h> 37#include <sys/dsl_dataset.h> 38#include <sys/vdev_impl.h> 39#include <sys/dmu_tx.h> 40#include <sys/dsl_pool.h> 41 42/* 43 * The zfs intent log (ZIL) saves transaction records of system calls 44 * that change the file system in memory with enough information 45 * to be able to replay them. These are stored in memory until 46 * either the DMU transaction group (txg) commits them to the stable pool 47 * and they can be discarded, or they are flushed to the stable log 48 * (also in the pool) due to a fsync, O_DSYNC or other synchronous 49 * requirement. In the event of a panic or power fail then those log 50 * records (transactions) are replayed. 51 * 52 * There is one ZIL per file system. Its on-disk (pool) format consists 53 * of 3 parts: 54 * 55 * - ZIL header 56 * - ZIL blocks 57 * - ZIL records 58 * 59 * A log record holds a system call transaction. Log blocks can 60 * hold many log records and the blocks are chained together. 61 * Each ZIL block contains a block pointer (blkptr_t) to the next 62 * ZIL block in the chain. The ZIL header points to the first 63 * block in the chain. Note there is not a fixed place in the pool 64 * to hold blocks. They are dynamically allocated and freed as 65 * needed from the blocks available. Figure X shows the ZIL structure: 66 */ 67 68/* 69 * This global ZIL switch affects all pools 70 */ 71int zil_replay_disable = 0; /* disable intent logging replay */ 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_notrim = B_TRUE; 87TUNABLE_INT("vfs.zfs.trim_disable", &zfs_notrim); 88SYSCTL_INT(_vfs_zfs, OID_AUTO, trim_disable, CTLFLAG_RDTUN, &zfs_notrim, 0, 89 "Disable trim"); 90 91static kmem_cache_t *zil_lwb_cache; 92 93static void zil_async_to_sync(zilog_t *zilog, uint64_t foid); 94 95#define LWB_EMPTY(lwb) ((BP_GET_LSIZE(&lwb->lwb_blk) - \ 96 sizeof (zil_chain_t)) == (lwb->lwb_sz - lwb->lwb_nused)) 97 98 99/* 100 * ziltest is by and large an ugly hack, but very useful in 101 * checking replay without tedious work. 102 * When running ziltest we want to keep all itx's and so maintain 103 * a single list in the zl_itxg[] that uses a high txg: ZILTEST_TXG 104 * We subtract TXG_CONCURRENT_STATES to allow for common code. 105 */ 106#define ZILTEST_TXG (UINT64_MAX - TXG_CONCURRENT_STATES) 107 108static int 109zil_bp_compare(const void *x1, const void *x2) 110{ 111 const dva_t *dva1 = &((zil_bp_node_t *)x1)->zn_dva; 112 const dva_t *dva2 = &((zil_bp_node_t *)x2)->zn_dva; 113 114 if (DVA_GET_VDEV(dva1) < DVA_GET_VDEV(dva2)) 115 return (-1); 116 if (DVA_GET_VDEV(dva1) > DVA_GET_VDEV(dva2)) 117 return (1); 118 119 if (DVA_GET_OFFSET(dva1) < DVA_GET_OFFSET(dva2)) 120 return (-1); 121 if (DVA_GET_OFFSET(dva1) > DVA_GET_OFFSET(dva2)) 122 return (1); 123 124 return (0); 125} 126 127static void 128zil_bp_tree_init(zilog_t *zilog) 129{ 130 avl_create(&zilog->zl_bp_tree, zil_bp_compare, 131 sizeof (zil_bp_node_t), offsetof(zil_bp_node_t, zn_node)); 132} 133 134static void 135zil_bp_tree_fini(zilog_t *zilog) 136{ 137 avl_tree_t *t = &zilog->zl_bp_tree; 138 zil_bp_node_t *zn; 139 void *cookie = NULL; 140 141 while ((zn = avl_destroy_nodes(t, &cookie)) != NULL) 142 kmem_free(zn, sizeof (zil_bp_node_t)); 143 144 avl_destroy(t); 145} 146 147int 148zil_bp_tree_add(zilog_t *zilog, const blkptr_t *bp) 149{ 150 avl_tree_t *t = &zilog->zl_bp_tree; 151 const dva_t *dva = BP_IDENTITY(bp); 152 zil_bp_node_t *zn; 153 avl_index_t where; 154 155 if (avl_find(t, dva, &where) != NULL) 156 return (EEXIST); 157 158 zn = kmem_alloc(sizeof (zil_bp_node_t), KM_SLEEP); 159 zn->zn_dva = *dva; 160 avl_insert(t, zn, where); 161 162 return (0); 163} 164 165static zil_header_t * 166zil_header_in_syncing_context(zilog_t *zilog) 167{ 168 return ((zil_header_t *)zilog->zl_header); 169} 170 171static void 172zil_init_log_chain(zilog_t *zilog, blkptr_t *bp) 173{ 174 zio_cksum_t *zc = &bp->blk_cksum; 175 176 zc->zc_word[ZIL_ZC_GUID_0] = spa_get_random(-1ULL); 177 zc->zc_word[ZIL_ZC_GUID_1] = spa_get_random(-1ULL); 178 zc->zc_word[ZIL_ZC_OBJSET] = dmu_objset_id(zilog->zl_os); 179 zc->zc_word[ZIL_ZC_SEQ] = 1ULL; 180} 181 182/* 183 * Read a log block and make sure it's valid. 184 */ 185static int 186zil_read_log_block(zilog_t *zilog, const blkptr_t *bp, blkptr_t *nbp, void *dst, 187 char **end) 188{ 189 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL; 190 uint32_t aflags = ARC_WAIT; 191 arc_buf_t *abuf = NULL; 192 zbookmark_t zb; 193 int error; 194 195 if (zilog->zl_header->zh_claim_txg == 0) 196 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; 197 198 if (!(zilog->zl_header->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) 199 zio_flags |= ZIO_FLAG_SPECULATIVE; 200 201 SET_BOOKMARK(&zb, bp->blk_cksum.zc_word[ZIL_ZC_OBJSET], 202 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]); 203 204 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf, 205 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); 206 207 if (error == 0) { 208 zio_cksum_t cksum = bp->blk_cksum; 209 210 /* 211 * Validate the checksummed log block. 212 * 213 * Sequence numbers should be... sequential. The checksum 214 * verifier for the next block should be bp's checksum plus 1. 215 * 216 * Also check the log chain linkage and size used. 217 */ 218 cksum.zc_word[ZIL_ZC_SEQ]++; 219 220 if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) { 221 zil_chain_t *zilc = abuf->b_data; 222 char *lr = (char *)(zilc + 1); 223 uint64_t len = zilc->zc_nused - sizeof (zil_chain_t); 224 225 if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum, 226 sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk)) { 227 error = ECKSUM; 228 } else { 229 bcopy(lr, dst, len); 230 *end = (char *)dst + len; 231 *nbp = zilc->zc_next_blk; 232 } 233 } else { 234 char *lr = abuf->b_data; 235 uint64_t size = BP_GET_LSIZE(bp); 236 zil_chain_t *zilc = (zil_chain_t *)(lr + size) - 1; 237 238 if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum, 239 sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk) || 240 (zilc->zc_nused > (size - sizeof (*zilc)))) { 241 error = ECKSUM; 242 } else { 243 bcopy(lr, dst, zilc->zc_nused); 244 *end = (char *)dst + zilc->zc_nused; 245 *nbp = zilc->zc_next_blk; 246 } 247 } 248 249 VERIFY(arc_buf_remove_ref(abuf, &abuf)); 250 } 251 252 return (error); 253} 254 255/* 256 * Read a TX_WRITE log data block. 257 */ 258static int 259zil_read_log_data(zilog_t *zilog, const lr_write_t *lr, void *wbuf) 260{ 261 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL; 262 const blkptr_t *bp = &lr->lr_blkptr; 263 uint32_t aflags = ARC_WAIT; 264 arc_buf_t *abuf = NULL; 265 zbookmark_t zb; 266 int error; 267 268 if (BP_IS_HOLE(bp)) { 269 if (wbuf != NULL) 270 bzero(wbuf, MAX(BP_GET_LSIZE(bp), lr->lr_length)); 271 return (0); 272 } 273 274 if (zilog->zl_header->zh_claim_txg == 0) 275 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; 276 277 SET_BOOKMARK(&zb, dmu_objset_id(zilog->zl_os), lr->lr_foid, 278 ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp)); 279 280 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf, 281 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); 282 283 if (error == 0) { 284 if (wbuf != NULL) 285 bcopy(abuf->b_data, wbuf, arc_buf_size(abuf)); 286 (void) arc_buf_remove_ref(abuf, &abuf); 287 } 288 289 return (error); 290} 291 292/* 293 * Parse the intent log, and call parse_func for each valid record within. 294 */ 295int 296zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func, 297 zil_parse_lr_func_t *parse_lr_func, void *arg, uint64_t txg) 298{ 299 const zil_header_t *zh = zilog->zl_header; 300 boolean_t claimed = !!zh->zh_claim_txg; 301 uint64_t claim_blk_seq = claimed ? zh->zh_claim_blk_seq : UINT64_MAX; 302 uint64_t claim_lr_seq = claimed ? zh->zh_claim_lr_seq : UINT64_MAX; 303 uint64_t max_blk_seq = 0; 304 uint64_t max_lr_seq = 0; 305 uint64_t blk_count = 0; 306 uint64_t lr_count = 0; 307 blkptr_t blk, next_blk; 308 char *lrbuf, *lrp; 309 int error = 0; 310 311 /* 312 * Old logs didn't record the maximum zh_claim_lr_seq. 313 */ 314 if (!(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) 315 claim_lr_seq = UINT64_MAX; 316 317 /* 318 * Starting at the block pointed to by zh_log we read the log chain. 319 * For each block in the chain we strongly check that block to 320 * ensure its validity. We stop when an invalid block is found. 321 * For each block pointer in the chain we call parse_blk_func(). 322 * For each record in each valid block we call parse_lr_func(). 323 * If the log has been claimed, stop if we encounter a sequence 324 * number greater than the highest claimed sequence number. 325 */ 326 lrbuf = zio_buf_alloc(SPA_MAXBLOCKSIZE); 327 zil_bp_tree_init(zilog); 328 329 for (blk = zh->zh_log; !BP_IS_HOLE(&blk); blk = next_blk) { 330 uint64_t blk_seq = blk.blk_cksum.zc_word[ZIL_ZC_SEQ]; 331 int reclen; 332 char *end; 333 334 if (blk_seq > claim_blk_seq) 335 break; 336 if ((error = parse_blk_func(zilog, &blk, arg, txg)) != 0) 337 break; 338 ASSERT3U(max_blk_seq, <, blk_seq); 339 max_blk_seq = blk_seq; 340 blk_count++; 341 342 if (max_lr_seq == claim_lr_seq && max_blk_seq == claim_blk_seq) 343 break; 344 345 error = zil_read_log_block(zilog, &blk, &next_blk, lrbuf, &end); 346 if (error != 0) 347 break; 348 349 for (lrp = lrbuf; lrp < end; lrp += reclen) { 350 lr_t *lr = (lr_t *)lrp; 351 reclen = lr->lrc_reclen; 352 ASSERT3U(reclen, >=, sizeof (lr_t)); 353 if (lr->lrc_seq > claim_lr_seq) 354 goto done; 355 if ((error = parse_lr_func(zilog, lr, arg, txg)) != 0) 356 goto done; 357 ASSERT3U(max_lr_seq, <, lr->lrc_seq); 358 max_lr_seq = lr->lrc_seq; 359 lr_count++; 360 } 361 } 362done: 363 zilog->zl_parse_error = error; 364 zilog->zl_parse_blk_seq = max_blk_seq; 365 zilog->zl_parse_lr_seq = max_lr_seq; 366 zilog->zl_parse_blk_count = blk_count; 367 zilog->zl_parse_lr_count = lr_count; 368 369 ASSERT(!claimed || !(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID) || 370 (max_blk_seq == claim_blk_seq && max_lr_seq == claim_lr_seq)); 371 372 zil_bp_tree_fini(zilog); 373 zio_buf_free(lrbuf, SPA_MAXBLOCKSIZE); 374 375 return (error); 376} 377 378static int 379zil_claim_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t first_txg) 380{ 381 /* 382 * Claim log block if not already committed and not already claimed. 383 * If tx == NULL, just verify that the block is claimable. 384 */ 385 if (bp->blk_birth < first_txg || zil_bp_tree_add(zilog, bp) != 0) 386 return (0); 387 388 return (zio_wait(zio_claim(NULL, zilog->zl_spa, 389 tx == NULL ? 0 : first_txg, bp, spa_claim_notify, NULL, 390 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB))); 391} 392 393static int 394zil_claim_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t first_txg) 395{ 396 lr_write_t *lr = (lr_write_t *)lrc; 397 int error; 398 399 if (lrc->lrc_txtype != TX_WRITE) 400 return (0); 401 402 /* 403 * If the block is not readable, don't claim it. This can happen 404 * in normal operation when a log block is written to disk before 405 * some of the dmu_sync() blocks it points to. In this case, the 406 * transaction cannot have been committed to anyone (we would have 407 * waited for all writes to be stable first), so it is semantically 408 * correct to declare this the end of the log. 409 */ 410 if (lr->lr_blkptr.blk_birth >= first_txg && 411 (error = zil_read_log_data(zilog, lr, NULL)) != 0) 412 return (error); 413 return (zil_claim_log_block(zilog, &lr->lr_blkptr, tx, first_txg)); 414} 415 416/* ARGSUSED */ 417static int 418zil_free_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t claim_txg) 419{ 420 zio_free_zil(zilog->zl_spa, dmu_tx_get_txg(tx), bp); 421 422 return (0); 423} 424 425static int 426zil_free_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t claim_txg) 427{ 428 lr_write_t *lr = (lr_write_t *)lrc; 429 blkptr_t *bp = &lr->lr_blkptr; 430 431 /* 432 * If we previously claimed it, we need to free it. 433 */ 434 if (claim_txg != 0 && lrc->lrc_txtype == TX_WRITE && 435 bp->blk_birth >= claim_txg && zil_bp_tree_add(zilog, bp) == 0) 436 zio_free(zilog->zl_spa, dmu_tx_get_txg(tx), bp); 437 438 return (0); 439} 440 441static lwb_t * 442zil_alloc_lwb(zilog_t *zilog, blkptr_t *bp, uint64_t txg) 443{ 444 lwb_t *lwb; 445 446 lwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP); 447 lwb->lwb_zilog = zilog; 448 lwb->lwb_blk = *bp; 449 lwb->lwb_buf = zio_buf_alloc(BP_GET_LSIZE(bp)); 450 lwb->lwb_max_txg = txg; 451 lwb->lwb_zio = NULL; 452 lwb->lwb_tx = NULL; 453 if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) { 454 lwb->lwb_nused = sizeof (zil_chain_t); 455 lwb->lwb_sz = BP_GET_LSIZE(bp); 456 } else { 457 lwb->lwb_nused = 0; 458 lwb->lwb_sz = BP_GET_LSIZE(bp) - sizeof (zil_chain_t); 459 } 460 461 mutex_enter(&zilog->zl_lock); 462 list_insert_tail(&zilog->zl_lwb_list, lwb); 463 mutex_exit(&zilog->zl_lock); 464 465 return (lwb); 466} 467 468/* 469 * Called when we create in-memory log transactions so that we know 470 * to cleanup the itxs at the end of spa_sync(). 471 */ 472void 473zilog_dirty(zilog_t *zilog, uint64_t txg) 474{ 475 dsl_pool_t *dp = zilog->zl_dmu_pool; 476 dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os); 477 478 if (dsl_dataset_is_snapshot(ds)) 479 panic("dirtying snapshot!"); 480 481 if (txg_list_add(&dp->dp_dirty_zilogs, zilog, txg)) { 482 /* up the hold count until we can be written out */ 483 dmu_buf_add_ref(ds->ds_dbuf, zilog); 484 } 485} 486 487boolean_t 488zilog_is_dirty(zilog_t *zilog) 489{ 490 dsl_pool_t *dp = zilog->zl_dmu_pool; 491 492 for (int t = 0; t < TXG_SIZE; t++) { 493 if (txg_list_member(&dp->dp_dirty_zilogs, zilog, t)) 494 return (B_TRUE); 495 } 496 return (B_FALSE); 497} 498 499/* 500 * Create an on-disk intent log. 501 */ 502static lwb_t * 503zil_create(zilog_t *zilog) 504{ 505 const zil_header_t *zh = zilog->zl_header; 506 lwb_t *lwb = NULL; 507 uint64_t txg = 0; 508 dmu_tx_t *tx = NULL; 509 blkptr_t blk; 510 int error = 0; 511 512 /* 513 * Wait for any previous destroy to complete. 514 */ 515 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 516 517 ASSERT(zh->zh_claim_txg == 0); 518 ASSERT(zh->zh_replay_seq == 0); 519 520 blk = zh->zh_log; 521 522 /* 523 * Allocate an initial log block if: 524 * - there isn't one already 525 * - the existing block is the wrong endianess 526 */ 527 if (BP_IS_HOLE(&blk) || BP_SHOULD_BYTESWAP(&blk)) { 528 tx = dmu_tx_create(zilog->zl_os); 529 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 530 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 531 txg = dmu_tx_get_txg(tx); 532 533 if (!BP_IS_HOLE(&blk)) { 534 zio_free_zil(zilog->zl_spa, txg, &blk); 535 BP_ZERO(&blk); 536 } 537 538 error = zio_alloc_zil(zilog->zl_spa, txg, &blk, NULL, 539 ZIL_MIN_BLKSZ, zilog->zl_logbias == ZFS_LOGBIAS_LATENCY); 540 541 if (error == 0) 542 zil_init_log_chain(zilog, &blk); 543 } 544 545 /* 546 * Allocate a log write buffer (lwb) for the first log block. 547 */ 548 if (error == 0) 549 lwb = zil_alloc_lwb(zilog, &blk, txg); 550 551 /* 552 * If we just allocated the first log block, commit our transaction 553 * and wait for zil_sync() to stuff the block poiner into zh_log. 554 * (zh is part of the MOS, so we cannot modify it in open context.) 555 */ 556 if (tx != NULL) { 557 dmu_tx_commit(tx); 558 txg_wait_synced(zilog->zl_dmu_pool, txg); 559 } 560 561 ASSERT(bcmp(&blk, &zh->zh_log, sizeof (blk)) == 0); 562 563 return (lwb); 564} 565 566/* 567 * In one tx, free all log blocks and clear the log header. 568 * If keep_first is set, then we're replaying a log with no content. 569 * We want to keep the first block, however, so that the first 570 * synchronous transaction doesn't require a txg_wait_synced() 571 * in zil_create(). We don't need to txg_wait_synced() here either 572 * when keep_first is set, because both zil_create() and zil_destroy() 573 * will wait for any in-progress destroys to complete. 574 */ 575void 576zil_destroy(zilog_t *zilog, boolean_t keep_first) 577{ 578 const zil_header_t *zh = zilog->zl_header; 579 lwb_t *lwb; 580 dmu_tx_t *tx; 581 uint64_t txg; 582 583 /* 584 * Wait for any previous destroy to complete. 585 */ 586 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 587 588 zilog->zl_old_header = *zh; /* debugging aid */ 589 590 if (BP_IS_HOLE(&zh->zh_log)) 591 return; 592 593 tx = dmu_tx_create(zilog->zl_os); 594 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 595 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 596 txg = dmu_tx_get_txg(tx); 597 598 mutex_enter(&zilog->zl_lock); 599 600 ASSERT3U(zilog->zl_destroy_txg, <, txg); 601 zilog->zl_destroy_txg = txg; 602 zilog->zl_keep_first = keep_first; 603 604 if (!list_is_empty(&zilog->zl_lwb_list)) { 605 ASSERT(zh->zh_claim_txg == 0); 606 VERIFY(!keep_first); 607 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { 608 list_remove(&zilog->zl_lwb_list, lwb); 609 if (lwb->lwb_buf != NULL) 610 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 611 zio_free_zil(zilog->zl_spa, txg, &lwb->lwb_blk); 612 kmem_cache_free(zil_lwb_cache, lwb); 613 } 614 } else if (!keep_first) { 615 zil_destroy_sync(zilog, tx); 616 } 617 mutex_exit(&zilog->zl_lock); 618 619 dmu_tx_commit(tx); 620} 621 622void 623zil_destroy_sync(zilog_t *zilog, dmu_tx_t *tx) 624{ 625 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 626 (void) zil_parse(zilog, zil_free_log_block, 627 zil_free_log_record, tx, zilog->zl_header->zh_claim_txg); 628} 629 630int 631zil_claim(const char *osname, void *txarg) 632{ 633 dmu_tx_t *tx = txarg; 634 uint64_t first_txg = dmu_tx_get_txg(tx); 635 zilog_t *zilog; 636 zil_header_t *zh; 637 objset_t *os; 638 int error; 639 640 error = dmu_objset_own(osname, DMU_OST_ANY, B_FALSE, FTAG, &os); 641 if (error != 0) { 642 cmn_err(CE_WARN, "can't open objset for %s", osname); 643 return (0); 644 } 645 646 zilog = dmu_objset_zil(os); 647 zh = zil_header_in_syncing_context(zilog); 648 649 if (spa_get_log_state(zilog->zl_spa) == SPA_LOG_CLEAR) { 650 if (!BP_IS_HOLE(&zh->zh_log)) 651 zio_free_zil(zilog->zl_spa, first_txg, &zh->zh_log); 652 BP_ZERO(&zh->zh_log); 653 dsl_dataset_dirty(dmu_objset_ds(os), tx); 654 dmu_objset_disown(os, FTAG); 655 return (0); 656 } 657 658 /* 659 * Claim all log blocks if we haven't already done so, and remember 660 * the highest claimed sequence number. This ensures that if we can 661 * read only part of the log now (e.g. due to a missing device), 662 * but we can read the entire log later, we will not try to replay 663 * or destroy beyond the last block we successfully claimed. 664 */ 665 ASSERT3U(zh->zh_claim_txg, <=, first_txg); 666 if (zh->zh_claim_txg == 0 && !BP_IS_HOLE(&zh->zh_log)) { 667 (void) zil_parse(zilog, zil_claim_log_block, 668 zil_claim_log_record, tx, first_txg); 669 zh->zh_claim_txg = first_txg; 670 zh->zh_claim_blk_seq = zilog->zl_parse_blk_seq; 671 zh->zh_claim_lr_seq = zilog->zl_parse_lr_seq; 672 if (zilog->zl_parse_lr_count || zilog->zl_parse_blk_count > 1) 673 zh->zh_flags |= ZIL_REPLAY_NEEDED; 674 zh->zh_flags |= ZIL_CLAIM_LR_SEQ_VALID; 675 dsl_dataset_dirty(dmu_objset_ds(os), tx); 676 } 677 678 ASSERT3U(first_txg, ==, (spa_last_synced_txg(zilog->zl_spa) + 1)); 679 dmu_objset_disown(os, FTAG); 680 return (0); 681} 682 683/* 684 * Check the log by walking the log chain. 685 * Checksum errors are ok as they indicate the end of the chain. 686 * Any other error (no device or read failure) returns an error. 687 */ 688int 689zil_check_log_chain(const char *osname, void *tx) 690{ 691 zilog_t *zilog; 692 objset_t *os; 693 blkptr_t *bp; 694 int error; 695 696 ASSERT(tx == NULL); 697 698 error = dmu_objset_hold(osname, FTAG, &os); 699 if (error != 0) { 700 cmn_err(CE_WARN, "can't open objset for %s", osname); 701 return (0); 702 } 703 704 zilog = dmu_objset_zil(os); 705 bp = (blkptr_t *)&zilog->zl_header->zh_log; 706 707 /* 708 * Check the first block and determine if it's on a log device 709 * which may have been removed or faulted prior to loading this 710 * pool. If so, there's no point in checking the rest of the log 711 * as its content should have already been synced to the pool. 712 */ 713 if (!BP_IS_HOLE(bp)) { 714 vdev_t *vd; 715 boolean_t valid = B_TRUE; 716 717 spa_config_enter(os->os_spa, SCL_STATE, FTAG, RW_READER); 718 vd = vdev_lookup_top(os->os_spa, DVA_GET_VDEV(&bp->blk_dva[0])); 719 if (vd->vdev_islog && vdev_is_dead(vd)) 720 valid = vdev_log_state_valid(vd); 721 spa_config_exit(os->os_spa, SCL_STATE, FTAG); 722 723 if (!valid) { 724 dmu_objset_rele(os, FTAG); 725 return (0); 726 } 727 } 728 729 /* 730 * Because tx == NULL, zil_claim_log_block() will not actually claim 731 * any blocks, but just determine whether it is possible to do so. 732 * In addition to checking the log chain, zil_claim_log_block() 733 * will invoke zio_claim() with a done func of spa_claim_notify(), 734 * which will update spa_max_claim_txg. See spa_load() for details. 735 */ 736 error = zil_parse(zilog, zil_claim_log_block, zil_claim_log_record, tx, 737 zilog->zl_header->zh_claim_txg ? -1ULL : spa_first_txg(os->os_spa)); 738 739 dmu_objset_rele(os, FTAG); 740 741 return ((error == ECKSUM || error == ENOENT) ? 0 : error); 742} 743 744static int 745zil_vdev_compare(const void *x1, const void *x2) 746{ 747 const uint64_t v1 = ((zil_vdev_node_t *)x1)->zv_vdev; 748 const uint64_t v2 = ((zil_vdev_node_t *)x2)->zv_vdev; 749 750 if (v1 < v2) 751 return (-1); 752 if (v1 > v2) 753 return (1); 754 755 return (0); 756} 757 758void 759zil_add_block(zilog_t *zilog, const blkptr_t *bp) 760{ 761 avl_tree_t *t = &zilog->zl_vdev_tree; 762 avl_index_t where; 763 zil_vdev_node_t *zv, zvsearch; 764 int ndvas = BP_GET_NDVAS(bp); 765 int i; 766 767 if (zfs_nocacheflush) 768 return; 769 770 ASSERT(zilog->zl_writer); 771 772 /* 773 * Even though we're zl_writer, we still need a lock because the 774 * zl_get_data() callbacks may have dmu_sync() done callbacks 775 * that will run concurrently. 776 */ 777 mutex_enter(&zilog->zl_vdev_lock); 778 for (i = 0; i < ndvas; i++) { 779 zvsearch.zv_vdev = DVA_GET_VDEV(&bp->blk_dva[i]); 780 if (avl_find(t, &zvsearch, &where) == NULL) { 781 zv = kmem_alloc(sizeof (*zv), KM_SLEEP); 782 zv->zv_vdev = zvsearch.zv_vdev; 783 avl_insert(t, zv, where); 784 } 785 } 786 mutex_exit(&zilog->zl_vdev_lock); 787} 788 789static void 790zil_flush_vdevs(zilog_t *zilog) 791{ 792 spa_t *spa = zilog->zl_spa; 793 avl_tree_t *t = &zilog->zl_vdev_tree; 794 void *cookie = NULL; 795 zil_vdev_node_t *zv; 796 zio_t *zio; 797 798 ASSERT(zilog->zl_writer); 799 800 /* 801 * We don't need zl_vdev_lock here because we're the zl_writer, 802 * and all zl_get_data() callbacks are done. 803 */ 804 if (avl_numnodes(t) == 0) 805 return; 806 807 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER); 808 809 zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL); 810 811 while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) { 812 vdev_t *vd = vdev_lookup_top(spa, zv->zv_vdev); 813 if (vd != NULL) 814 zio_flush(zio, vd); 815 kmem_free(zv, sizeof (*zv)); 816 } 817 818 /* 819 * Wait for all the flushes to complete. Not all devices actually 820 * support the DKIOCFLUSHWRITECACHE ioctl, so it's OK if it fails. 821 */ 822 (void) zio_wait(zio); 823 824 spa_config_exit(spa, SCL_STATE, FTAG); 825} 826 827/* 828 * Function called when a log block write completes 829 */ 830static void 831zil_lwb_write_done(zio_t *zio) 832{ 833 lwb_t *lwb = zio->io_private; 834 zilog_t *zilog = lwb->lwb_zilog; 835 dmu_tx_t *tx = lwb->lwb_tx; 836 837 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 838 ASSERT(BP_GET_TYPE(zio->io_bp) == DMU_OT_INTENT_LOG); 839 ASSERT(BP_GET_LEVEL(zio->io_bp) == 0); 840 ASSERT(BP_GET_BYTEORDER(zio->io_bp) == ZFS_HOST_BYTEORDER); 841 ASSERT(!BP_IS_GANG(zio->io_bp)); 842 ASSERT(!BP_IS_HOLE(zio->io_bp)); 843 ASSERT(zio->io_bp->blk_fill == 0); 844 845 /* 846 * Ensure the lwb buffer pointer is cleared before releasing 847 * the txg. If we have had an allocation failure and 848 * the txg is waiting to sync then we want want zil_sync() 849 * to remove the lwb so that it's not picked up as the next new 850 * one in zil_commit_writer(). zil_sync() will only remove 851 * the lwb if lwb_buf is null. 852 */ 853 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 854 mutex_enter(&zilog->zl_lock); 855 lwb->lwb_buf = NULL; 856 lwb->lwb_tx = NULL; 857 mutex_exit(&zilog->zl_lock); 858 859 /* 860 * Now that we've written this log block, we have a stable pointer 861 * to the next block in the chain, so it's OK to let the txg in 862 * which we allocated the next block sync. 863 */ 864 dmu_tx_commit(tx); 865} 866 867/* 868 * Initialize the io for a log block. 869 */ 870static void 871zil_lwb_write_init(zilog_t *zilog, lwb_t *lwb) 872{ 873 zbookmark_t zb; 874 875 SET_BOOKMARK(&zb, lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_OBJSET], 876 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, 877 lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_SEQ]); 878 879 if (zilog->zl_root_zio == NULL) { 880 zilog->zl_root_zio = zio_root(zilog->zl_spa, NULL, NULL, 881 ZIO_FLAG_CANFAIL); 882 } 883 if (lwb->lwb_zio == NULL) { 884 lwb->lwb_zio = zio_rewrite(zilog->zl_root_zio, zilog->zl_spa, 885 0, &lwb->lwb_blk, lwb->lwb_buf, BP_GET_LSIZE(&lwb->lwb_blk), 886 zil_lwb_write_done, lwb, ZIO_PRIORITY_LOG_WRITE, 887 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE, &zb); 888 } 889} 890 891/* 892 * Define a limited set of intent log block sizes. 893 * These must be a multiple of 4KB. Note only the amount used (again 894 * aligned to 4KB) actually gets written. However, we can't always just 895 * allocate SPA_MAXBLOCKSIZE as the slog space could be exhausted. 896 */ 897uint64_t zil_block_buckets[] = { 898 4096, /* non TX_WRITE */ 899 8192+4096, /* data base */ 900 32*1024 + 4096, /* NFS writes */ 901 UINT64_MAX 902}; 903 904/* 905 * Use the slog as long as the logbias is 'latency' and the current commit size 906 * is less than the limit or the total list size is less than 2X the limit. 907 * Limit checking is disabled by setting zil_slog_limit to UINT64_MAX. 908 */ 909uint64_t zil_slog_limit = 1024 * 1024; 910#define USE_SLOG(zilog) (((zilog)->zl_logbias == ZFS_LOGBIAS_LATENCY) && \ 911 (((zilog)->zl_cur_used < zil_slog_limit) || \ 912 ((zilog)->zl_itx_list_sz < (zil_slog_limit << 1)))) 913 914/* 915 * Start a log block write and advance to the next log block. 916 * Calls are serialized. 917 */ 918static lwb_t * 919zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb) 920{ 921 lwb_t *nlwb = NULL; 922 zil_chain_t *zilc; 923 spa_t *spa = zilog->zl_spa; 924 blkptr_t *bp; 925 dmu_tx_t *tx; 926 uint64_t txg; 927 uint64_t zil_blksz, wsz; 928 int i, error; 929 930 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) { 931 zilc = (zil_chain_t *)lwb->lwb_buf; 932 bp = &zilc->zc_next_blk; 933 } else { 934 zilc = (zil_chain_t *)(lwb->lwb_buf + lwb->lwb_sz); 935 bp = &zilc->zc_next_blk; 936 } 937 938 ASSERT(lwb->lwb_nused <= lwb->lwb_sz); 939 940 /* 941 * Allocate the next block and save its address in this block 942 * before writing it in order to establish the log chain. 943 * Note that if the allocation of nlwb synced before we wrote 944 * the block that points at it (lwb), we'd leak it if we crashed. 945 * Therefore, we don't do dmu_tx_commit() until zil_lwb_write_done(). 946 * We dirty the dataset to ensure that zil_sync() will be called 947 * to clean up in the event of allocation failure or I/O failure. 948 */ 949 tx = dmu_tx_create(zilog->zl_os); 950 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 951 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 952 txg = dmu_tx_get_txg(tx); 953 954 lwb->lwb_tx = tx; 955 956 /* 957 * Log blocks are pre-allocated. Here we select the size of the next 958 * block, based on size used in the last block. 959 * - first find the smallest bucket that will fit the block from a 960 * limited set of block sizes. This is because it's faster to write 961 * blocks allocated from the same metaslab as they are adjacent or 962 * close. 963 * - next find the maximum from the new suggested size and an array of 964 * previous sizes. This lessens a picket fence effect of wrongly 965 * guesssing the size if we have a stream of say 2k, 64k, 2k, 64k 966 * requests. 967 * 968 * Note we only write what is used, but we can't just allocate 969 * the maximum block size because we can exhaust the available 970 * pool log space. 971 */ 972 zil_blksz = zilog->zl_cur_used + sizeof (zil_chain_t); 973 for (i = 0; zil_blksz > zil_block_buckets[i]; i++) 974 continue; 975 zil_blksz = zil_block_buckets[i]; 976 if (zil_blksz == UINT64_MAX) 977 zil_blksz = SPA_MAXBLOCKSIZE; 978 zilog->zl_prev_blks[zilog->zl_prev_rotor] = zil_blksz; 979 for (i = 0; i < ZIL_PREV_BLKS; i++) 980 zil_blksz = MAX(zil_blksz, zilog->zl_prev_blks[i]); 981 zilog->zl_prev_rotor = (zilog->zl_prev_rotor + 1) & (ZIL_PREV_BLKS - 1); 982 983 BP_ZERO(bp); 984 /* pass the old blkptr in order to spread log blocks across devs */ 985 error = zio_alloc_zil(spa, txg, bp, &lwb->lwb_blk, zil_blksz, 986 USE_SLOG(zilog)); 987 if (error == 0) { 988 ASSERT3U(bp->blk_birth, ==, txg); 989 bp->blk_cksum = lwb->lwb_blk.blk_cksum; 990 bp->blk_cksum.zc_word[ZIL_ZC_SEQ]++; 991 992 /* 993 * Allocate a new log write buffer (lwb). 994 */ 995 nlwb = zil_alloc_lwb(zilog, bp, txg); 996 997 /* Record the block for later vdev flushing */ 998 zil_add_block(zilog, &lwb->lwb_blk); 999 } 1000 1001 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) { 1002 /* For Slim ZIL only write what is used. */ 1003 wsz = P2ROUNDUP_TYPED(lwb->lwb_nused, ZIL_MIN_BLKSZ, uint64_t); 1004 ASSERT3U(wsz, <=, lwb->lwb_sz); 1005 zio_shrink(lwb->lwb_zio, wsz); 1006 1007 } else { 1008 wsz = lwb->lwb_sz; 1009 } 1010 1011 zilc->zc_pad = 0; 1012 zilc->zc_nused = lwb->lwb_nused; 1013 zilc->zc_eck.zec_cksum = lwb->lwb_blk.blk_cksum; 1014 1015 /* 1016 * clear unused data for security 1017 */ 1018 bzero(lwb->lwb_buf + lwb->lwb_nused, wsz - lwb->lwb_nused); 1019 1020 zio_nowait(lwb->lwb_zio); /* Kick off the write for the old log block */ 1021 1022 /* 1023 * If there was an allocation failure then nlwb will be null which 1024 * forces a txg_wait_synced(). 1025 */ 1026 return (nlwb); 1027} 1028 1029static lwb_t * 1030zil_lwb_commit(zilog_t *zilog, itx_t *itx, lwb_t *lwb) 1031{ 1032 lr_t *lrc = &itx->itx_lr; /* common log record */ 1033 lr_write_t *lrw = (lr_write_t *)lrc; 1034 char *lr_buf; 1035 uint64_t txg = lrc->lrc_txg; 1036 uint64_t reclen = lrc->lrc_reclen; 1037 uint64_t dlen = 0; 1038 1039 if (lwb == NULL) 1040 return (NULL); 1041 1042 ASSERT(lwb->lwb_buf != NULL); 1043 ASSERT(zilog_is_dirty(zilog) || 1044 spa_freeze_txg(zilog->zl_spa) != UINT64_MAX); 1045 1046 if (lrc->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY) 1047 dlen = P2ROUNDUP_TYPED( 1048 lrw->lr_length, sizeof (uint64_t), uint64_t); 1049 1050 zilog->zl_cur_used += (reclen + dlen); 1051 1052 zil_lwb_write_init(zilog, lwb); 1053 1054 /* 1055 * If this record won't fit in the current log block, start a new one. 1056 */ 1057 if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) { 1058 lwb = zil_lwb_write_start(zilog, lwb); 1059 if (lwb == NULL) 1060 return (NULL); 1061 zil_lwb_write_init(zilog, lwb); 1062 ASSERT(LWB_EMPTY(lwb)); 1063 if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) { 1064 txg_wait_synced(zilog->zl_dmu_pool, txg); 1065 return (lwb); 1066 } 1067 } 1068 1069 lr_buf = lwb->lwb_buf + lwb->lwb_nused; 1070 bcopy(lrc, lr_buf, reclen); 1071 lrc = (lr_t *)lr_buf; 1072 lrw = (lr_write_t *)lrc; 1073 1074 /* 1075 * If it's a write, fetch the data or get its blkptr as appropriate. 1076 */ 1077 if (lrc->lrc_txtype == TX_WRITE) { 1078 if (txg > spa_freeze_txg(zilog->zl_spa)) 1079 txg_wait_synced(zilog->zl_dmu_pool, txg); 1080 if (itx->itx_wr_state != WR_COPIED) { 1081 char *dbuf; 1082 int error; 1083 1084 if (dlen) { 1085 ASSERT(itx->itx_wr_state == WR_NEED_COPY); 1086 dbuf = lr_buf + reclen; 1087 lrw->lr_common.lrc_reclen += dlen; 1088 } else { 1089 ASSERT(itx->itx_wr_state == WR_INDIRECT); 1090 dbuf = NULL; 1091 } 1092 error = zilog->zl_get_data( 1093 itx->itx_private, lrw, dbuf, lwb->lwb_zio); 1094 if (error == EIO) { 1095 txg_wait_synced(zilog->zl_dmu_pool, txg); 1096 return (lwb); 1097 } 1098 if (error != 0) { 1099 ASSERT(error == ENOENT || error == EEXIST || 1100 error == EALREADY); 1101 return (lwb); 1102 } 1103 } 1104 } 1105 1106 /* 1107 * We're actually making an entry, so update lrc_seq to be the 1108 * log record sequence number. Note that this is generally not 1109 * equal to the itx sequence number because not all transactions 1110 * are synchronous, and sometimes spa_sync() gets there first. 1111 */ 1112 lrc->lrc_seq = ++zilog->zl_lr_seq; /* we are single threaded */ 1113 lwb->lwb_nused += reclen + dlen; 1114 lwb->lwb_max_txg = MAX(lwb->lwb_max_txg, txg); 1115 ASSERT3U(lwb->lwb_nused, <=, lwb->lwb_sz); 1116 ASSERT0(P2PHASE(lwb->lwb_nused, sizeof (uint64_t))); 1117 1118 return (lwb); 1119} 1120 1121itx_t * 1122zil_itx_create(uint64_t txtype, size_t lrsize) 1123{ 1124 itx_t *itx; 1125 1126 lrsize = P2ROUNDUP_TYPED(lrsize, sizeof (uint64_t), size_t); 1127 1128 itx = kmem_alloc(offsetof(itx_t, itx_lr) + lrsize, KM_SLEEP); 1129 itx->itx_lr.lrc_txtype = txtype; 1130 itx->itx_lr.lrc_reclen = lrsize; 1131 itx->itx_sod = lrsize; /* if write & WR_NEED_COPY will be increased */ 1132 itx->itx_lr.lrc_seq = 0; /* defensive */ 1133 itx->itx_sync = B_TRUE; /* default is synchronous */ 1134 1135 return (itx); 1136} 1137 1138void 1139zil_itx_destroy(itx_t *itx) 1140{ 1141 kmem_free(itx, offsetof(itx_t, itx_lr) + itx->itx_lr.lrc_reclen); 1142} 1143 1144/* 1145 * Free up the sync and async itxs. The itxs_t has already been detached 1146 * so no locks are needed. 1147 */ 1148static void 1149zil_itxg_clean(itxs_t *itxs) 1150{ 1151 itx_t *itx; 1152 list_t *list; 1153 avl_tree_t *t; 1154 void *cookie; 1155 itx_async_node_t *ian; 1156 1157 list = &itxs->i_sync_list; 1158 while ((itx = list_head(list)) != NULL) { 1159 list_remove(list, itx); 1160 kmem_free(itx, offsetof(itx_t, itx_lr) + 1161 itx->itx_lr.lrc_reclen); 1162 } 1163 1164 cookie = NULL; 1165 t = &itxs->i_async_tree; 1166 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) { 1167 list = &ian->ia_list; 1168 while ((itx = list_head(list)) != NULL) { 1169 list_remove(list, itx); 1170 kmem_free(itx, offsetof(itx_t, itx_lr) + 1171 itx->itx_lr.lrc_reclen); 1172 } 1173 list_destroy(list); 1174 kmem_free(ian, sizeof (itx_async_node_t)); 1175 } 1176 avl_destroy(t); 1177 1178 kmem_free(itxs, sizeof (itxs_t)); 1179} 1180 1181static int 1182zil_aitx_compare(const void *x1, const void *x2) 1183{ 1184 const uint64_t o1 = ((itx_async_node_t *)x1)->ia_foid; 1185 const uint64_t o2 = ((itx_async_node_t *)x2)->ia_foid; 1186 1187 if (o1 < o2) 1188 return (-1); 1189 if (o1 > o2) 1190 return (1); 1191 1192 return (0); 1193} 1194 1195/* 1196 * Remove all async itx with the given oid. 1197 */ 1198static void 1199zil_remove_async(zilog_t *zilog, uint64_t oid) 1200{ 1201 uint64_t otxg, txg; 1202 itx_async_node_t *ian; 1203 avl_tree_t *t; 1204 avl_index_t where; 1205 list_t clean_list; 1206 itx_t *itx; 1207 1208 ASSERT(oid != 0); 1209 list_create(&clean_list, sizeof (itx_t), offsetof(itx_t, itx_node)); 1210 1211 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1212 otxg = ZILTEST_TXG; 1213 else 1214 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1215 1216 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1217 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1218 1219 mutex_enter(&itxg->itxg_lock); 1220 if (itxg->itxg_txg != txg) { 1221 mutex_exit(&itxg->itxg_lock); 1222 continue; 1223 } 1224 1225 /* 1226 * Locate the object node and append its list. 1227 */ 1228 t = &itxg->itxg_itxs->i_async_tree; 1229 ian = avl_find(t, &oid, &where); 1230 if (ian != NULL) 1231 list_move_tail(&clean_list, &ian->ia_list); 1232 mutex_exit(&itxg->itxg_lock); 1233 } 1234 while ((itx = list_head(&clean_list)) != NULL) { 1235 list_remove(&clean_list, itx); 1236 kmem_free(itx, offsetof(itx_t, itx_lr) + 1237 itx->itx_lr.lrc_reclen); 1238 } 1239 list_destroy(&clean_list); 1240} 1241 1242void 1243zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx) 1244{ 1245 uint64_t txg; 1246 itxg_t *itxg; 1247 itxs_t *itxs, *clean = NULL; 1248 1249 /* 1250 * Object ids can be re-instantiated in the next txg so 1251 * remove any async transactions to avoid future leaks. 1252 * This can happen if a fsync occurs on the re-instantiated 1253 * object for a WR_INDIRECT or WR_NEED_COPY write, which gets 1254 * the new file data and flushes a write record for the old object. 1255 */ 1256 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_REMOVE) 1257 zil_remove_async(zilog, itx->itx_oid); 1258 1259 /* 1260 * Ensure the data of a renamed file is committed before the rename. 1261 */ 1262 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_RENAME) 1263 zil_async_to_sync(zilog, itx->itx_oid); 1264 1265 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) 1266 txg = ZILTEST_TXG; 1267 else 1268 txg = dmu_tx_get_txg(tx); 1269 1270 itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1271 mutex_enter(&itxg->itxg_lock); 1272 itxs = itxg->itxg_itxs; 1273 if (itxg->itxg_txg != txg) { 1274 if (itxs != NULL) { 1275 /* 1276 * The zil_clean callback hasn't got around to cleaning 1277 * this itxg. Save the itxs for release below. 1278 * This should be rare. 1279 */ 1280 atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod); 1281 itxg->itxg_sod = 0; 1282 clean = itxg->itxg_itxs; 1283 } 1284 ASSERT(itxg->itxg_sod == 0); 1285 itxg->itxg_txg = txg; 1286 itxs = itxg->itxg_itxs = kmem_zalloc(sizeof (itxs_t), KM_SLEEP); 1287 1288 list_create(&itxs->i_sync_list, sizeof (itx_t), 1289 offsetof(itx_t, itx_node)); 1290 avl_create(&itxs->i_async_tree, zil_aitx_compare, 1291 sizeof (itx_async_node_t), 1292 offsetof(itx_async_node_t, ia_node)); 1293 } 1294 if (itx->itx_sync) { 1295 list_insert_tail(&itxs->i_sync_list, itx); 1296 atomic_add_64(&zilog->zl_itx_list_sz, itx->itx_sod); 1297 itxg->itxg_sod += itx->itx_sod; 1298 } else { 1299 avl_tree_t *t = &itxs->i_async_tree; 1300 uint64_t foid = ((lr_ooo_t *)&itx->itx_lr)->lr_foid; 1301 itx_async_node_t *ian; 1302 avl_index_t where; 1303 1304 ian = avl_find(t, &foid, &where); 1305 if (ian == NULL) { 1306 ian = kmem_alloc(sizeof (itx_async_node_t), KM_SLEEP); 1307 list_create(&ian->ia_list, sizeof (itx_t), 1308 offsetof(itx_t, itx_node)); 1309 ian->ia_foid = foid; 1310 avl_insert(t, ian, where); 1311 } 1312 list_insert_tail(&ian->ia_list, itx); 1313 } 1314 1315 itx->itx_lr.lrc_txg = dmu_tx_get_txg(tx); 1316 zilog_dirty(zilog, txg); 1317 mutex_exit(&itxg->itxg_lock); 1318 1319 /* Release the old itxs now we've dropped the lock */ 1320 if (clean != NULL) 1321 zil_itxg_clean(clean); 1322} 1323 1324/* 1325 * If there are any in-memory intent log transactions which have now been 1326 * synced then start up a taskq to free them. We should only do this after we 1327 * have written out the uberblocks (i.e. txg has been comitted) so that 1328 * don't inadvertently clean out in-memory log records that would be required 1329 * by zil_commit(). 1330 */ 1331void 1332zil_clean(zilog_t *zilog, uint64_t synced_txg) 1333{ 1334 itxg_t *itxg = &zilog->zl_itxg[synced_txg & TXG_MASK]; 1335 itxs_t *clean_me; 1336 1337 mutex_enter(&itxg->itxg_lock); 1338 if (itxg->itxg_itxs == NULL || itxg->itxg_txg == ZILTEST_TXG) { 1339 mutex_exit(&itxg->itxg_lock); 1340 return; 1341 } 1342 ASSERT3U(itxg->itxg_txg, <=, synced_txg); 1343 ASSERT(itxg->itxg_txg != 0); 1344 ASSERT(zilog->zl_clean_taskq != NULL); 1345 atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod); 1346 itxg->itxg_sod = 0; 1347 clean_me = itxg->itxg_itxs; 1348 itxg->itxg_itxs = NULL; 1349 itxg->itxg_txg = 0; 1350 mutex_exit(&itxg->itxg_lock); 1351 /* 1352 * Preferably start a task queue to free up the old itxs but 1353 * if taskq_dispatch can't allocate resources to do that then 1354 * free it in-line. This should be rare. Note, using TQ_SLEEP 1355 * created a bad performance problem. 1356 */ 1357 if (taskq_dispatch(zilog->zl_clean_taskq, 1358 (void (*)(void *))zil_itxg_clean, clean_me, TQ_NOSLEEP) == 0) 1359 zil_itxg_clean(clean_me); 1360} 1361 1362/* 1363 * Get the list of itxs to commit into zl_itx_commit_list. 1364 */ 1365static void 1366zil_get_commit_list(zilog_t *zilog) 1367{ 1368 uint64_t otxg, txg; 1369 list_t *commit_list = &zilog->zl_itx_commit_list; 1370 uint64_t push_sod = 0; 1371 1372 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1373 otxg = ZILTEST_TXG; 1374 else 1375 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1376 1377 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1378 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1379 1380 mutex_enter(&itxg->itxg_lock); 1381 if (itxg->itxg_txg != txg) { 1382 mutex_exit(&itxg->itxg_lock); 1383 continue; 1384 } 1385 1386 list_move_tail(commit_list, &itxg->itxg_itxs->i_sync_list); 1387 push_sod += itxg->itxg_sod; 1388 itxg->itxg_sod = 0; 1389 1390 mutex_exit(&itxg->itxg_lock); 1391 } 1392 atomic_add_64(&zilog->zl_itx_list_sz, -push_sod); 1393} 1394 1395/* 1396 * Move the async itxs for a specified object to commit into sync lists. 1397 */ 1398static void 1399zil_async_to_sync(zilog_t *zilog, uint64_t foid) 1400{ 1401 uint64_t otxg, txg; 1402 itx_async_node_t *ian; 1403 avl_tree_t *t; 1404 avl_index_t where; 1405 1406 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1407 otxg = ZILTEST_TXG; 1408 else 1409 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1410 1411 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1412 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1413 1414 mutex_enter(&itxg->itxg_lock); 1415 if (itxg->itxg_txg != txg) { 1416 mutex_exit(&itxg->itxg_lock); 1417 continue; 1418 } 1419 1420 /* 1421 * If a foid is specified then find that node and append its 1422 * list. Otherwise walk the tree appending all the lists 1423 * to the sync list. We add to the end rather than the 1424 * beginning to ensure the create has happened. 1425 */ 1426 t = &itxg->itxg_itxs->i_async_tree; 1427 if (foid != 0) { 1428 ian = avl_find(t, &foid, &where); 1429 if (ian != NULL) { 1430 list_move_tail(&itxg->itxg_itxs->i_sync_list, 1431 &ian->ia_list); 1432 } 1433 } else { 1434 void *cookie = NULL; 1435 1436 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) { 1437 list_move_tail(&itxg->itxg_itxs->i_sync_list, 1438 &ian->ia_list); 1439 list_destroy(&ian->ia_list); 1440 kmem_free(ian, sizeof (itx_async_node_t)); 1441 } 1442 } 1443 mutex_exit(&itxg->itxg_lock); 1444 } 1445} 1446 1447static void 1448zil_commit_writer(zilog_t *zilog) 1449{ 1450 uint64_t txg; 1451 itx_t *itx; 1452 lwb_t *lwb; 1453 spa_t *spa = zilog->zl_spa; 1454 int error = 0; 1455 1456 ASSERT(zilog->zl_root_zio == NULL); 1457 1458 mutex_exit(&zilog->zl_lock); 1459 1460 zil_get_commit_list(zilog); 1461 1462 /* 1463 * Return if there's nothing to commit before we dirty the fs by 1464 * calling zil_create(). 1465 */ 1466 if (list_head(&zilog->zl_itx_commit_list) == NULL) { 1467 mutex_enter(&zilog->zl_lock); 1468 return; 1469 } 1470 1471 if (zilog->zl_suspend) { 1472 lwb = NULL; 1473 } else { 1474 lwb = list_tail(&zilog->zl_lwb_list); 1475 if (lwb == NULL) 1476 lwb = zil_create(zilog); 1477 } 1478 1479 DTRACE_PROBE1(zil__cw1, zilog_t *, zilog); 1480 while (itx = list_head(&zilog->zl_itx_commit_list)) { 1481 txg = itx->itx_lr.lrc_txg; 1482 ASSERT(txg); 1483 1484 if (txg > spa_last_synced_txg(spa) || txg > spa_freeze_txg(spa)) 1485 lwb = zil_lwb_commit(zilog, itx, lwb); 1486 list_remove(&zilog->zl_itx_commit_list, itx); 1487 kmem_free(itx, offsetof(itx_t, itx_lr) 1488 + itx->itx_lr.lrc_reclen); 1489 } 1490 DTRACE_PROBE1(zil__cw2, zilog_t *, zilog); 1491 1492 /* write the last block out */ 1493 if (lwb != NULL && lwb->lwb_zio != NULL) 1494 lwb = zil_lwb_write_start(zilog, lwb); 1495 1496 zilog->zl_cur_used = 0; 1497 1498 /* 1499 * Wait if necessary for the log blocks to be on stable storage. 1500 */ 1501 if (zilog->zl_root_zio) { 1502 error = zio_wait(zilog->zl_root_zio); 1503 zilog->zl_root_zio = NULL; 1504 zil_flush_vdevs(zilog); 1505 } 1506 1507 if (error || lwb == NULL) 1508 txg_wait_synced(zilog->zl_dmu_pool, 0); 1509 1510 mutex_enter(&zilog->zl_lock); 1511 1512 /* 1513 * Remember the highest committed log sequence number for ztest. 1514 * We only update this value when all the log writes succeeded, 1515 * because ztest wants to ASSERT that it got the whole log chain. 1516 */ 1517 if (error == 0 && lwb != NULL) 1518 zilog->zl_commit_lr_seq = zilog->zl_lr_seq; 1519} 1520 1521/* 1522 * Commit zfs transactions to stable storage. 1523 * If foid is 0 push out all transactions, otherwise push only those 1524 * for that object or might reference that object. 1525 * 1526 * itxs are committed in batches. In a heavily stressed zil there will be 1527 * a commit writer thread who is writing out a bunch of itxs to the log 1528 * for a set of committing threads (cthreads) in the same batch as the writer. 1529 * Those cthreads are all waiting on the same cv for that batch. 1530 * 1531 * There will also be a different and growing batch of threads that are 1532 * waiting to commit (qthreads). When the committing batch completes 1533 * a transition occurs such that the cthreads exit and the qthreads become 1534 * cthreads. One of the new cthreads becomes the writer thread for the 1535 * batch. Any new threads arriving become new qthreads. 1536 * 1537 * Only 2 condition variables are needed and there's no transition 1538 * between the two cvs needed. They just flip-flop between qthreads 1539 * and cthreads. 1540 * 1541 * Using this scheme we can efficiently wakeup up only those threads 1542 * that have been committed. 1543 */ 1544void 1545zil_commit(zilog_t *zilog, uint64_t foid) 1546{ 1547 uint64_t mybatch; 1548 1549 if (zilog->zl_sync == ZFS_SYNC_DISABLED) 1550 return; 1551 1552 /* move the async itxs for the foid to the sync queues */ 1553 zil_async_to_sync(zilog, foid); 1554 1555 mutex_enter(&zilog->zl_lock); 1556 mybatch = zilog->zl_next_batch; 1557 while (zilog->zl_writer) { 1558 cv_wait(&zilog->zl_cv_batch[mybatch & 1], &zilog->zl_lock); 1559 if (mybatch <= zilog->zl_com_batch) { 1560 mutex_exit(&zilog->zl_lock); 1561 return; 1562 } 1563 } 1564 1565 zilog->zl_next_batch++; 1566 zilog->zl_writer = B_TRUE; 1567 zil_commit_writer(zilog); 1568 zilog->zl_com_batch = mybatch; 1569 zilog->zl_writer = B_FALSE; 1570 mutex_exit(&zilog->zl_lock); 1571 1572 /* wake up one thread to become the next writer */ 1573 cv_signal(&zilog->zl_cv_batch[(mybatch+1) & 1]); 1574 1575 /* wake up all threads waiting for this batch to be committed */ 1576 cv_broadcast(&zilog->zl_cv_batch[mybatch & 1]); 1577} 1578 1579/* 1580 * Called in syncing context to free committed log blocks and update log header. 1581 */ 1582void 1583zil_sync(zilog_t *zilog, dmu_tx_t *tx) 1584{ 1585 zil_header_t *zh = zil_header_in_syncing_context(zilog); 1586 uint64_t txg = dmu_tx_get_txg(tx); 1587 spa_t *spa = zilog->zl_spa; 1588 uint64_t *replayed_seq = &zilog->zl_replayed_seq[txg & TXG_MASK]; 1589 lwb_t *lwb; 1590 1591 /* 1592 * We don't zero out zl_destroy_txg, so make sure we don't try 1593 * to destroy it twice. 1594 */ 1595 if (spa_sync_pass(spa) != 1) 1596 return; 1597 1598 mutex_enter(&zilog->zl_lock); 1599 1600 ASSERT(zilog->zl_stop_sync == 0); 1601 1602 if (*replayed_seq != 0) { 1603 ASSERT(zh->zh_replay_seq < *replayed_seq); 1604 zh->zh_replay_seq = *replayed_seq; 1605 *replayed_seq = 0; 1606 } 1607 1608 if (zilog->zl_destroy_txg == txg) { 1609 blkptr_t blk = zh->zh_log; 1610 1611 ASSERT(list_head(&zilog->zl_lwb_list) == NULL); 1612 1613 bzero(zh, sizeof (zil_header_t)); 1614 bzero(zilog->zl_replayed_seq, sizeof (zilog->zl_replayed_seq)); 1615 1616 if (zilog->zl_keep_first) { 1617 /* 1618 * If this block was part of log chain that couldn't 1619 * be claimed because a device was missing during 1620 * zil_claim(), but that device later returns, 1621 * then this block could erroneously appear valid. 1622 * To guard against this, assign a new GUID to the new 1623 * log chain so it doesn't matter what blk points to. 1624 */ 1625 zil_init_log_chain(zilog, &blk); 1626 zh->zh_log = blk; 1627 } 1628 } 1629 1630 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { 1631 zh->zh_log = lwb->lwb_blk; 1632 if (lwb->lwb_buf != NULL || lwb->lwb_max_txg > txg) 1633 break; 1634 list_remove(&zilog->zl_lwb_list, lwb); 1635 zio_free_zil(spa, txg, &lwb->lwb_blk); 1636 kmem_cache_free(zil_lwb_cache, lwb); 1637 1638 /* 1639 * If we don't have anything left in the lwb list then 1640 * we've had an allocation failure and we need to zero 1641 * out the zil_header blkptr so that we don't end 1642 * up freeing the same block twice. 1643 */ 1644 if (list_head(&zilog->zl_lwb_list) == NULL) 1645 BP_ZERO(&zh->zh_log); 1646 } 1647 mutex_exit(&zilog->zl_lock); 1648} 1649 1650void 1651zil_init(void) 1652{ 1653 zil_lwb_cache = kmem_cache_create("zil_lwb_cache", 1654 sizeof (struct lwb), 0, NULL, NULL, NULL, NULL, NULL, 0); 1655} 1656 1657void 1658zil_fini(void) 1659{ 1660 kmem_cache_destroy(zil_lwb_cache); 1661} 1662 1663void 1664zil_set_sync(zilog_t *zilog, uint64_t sync) 1665{ 1666 zilog->zl_sync = sync; 1667} 1668 1669void 1670zil_set_logbias(zilog_t *zilog, uint64_t logbias) 1671{ 1672 zilog->zl_logbias = logbias; 1673} 1674 1675zilog_t * 1676zil_alloc(objset_t *os, zil_header_t *zh_phys) 1677{ 1678 zilog_t *zilog; 1679 1680 zilog = kmem_zalloc(sizeof (zilog_t), KM_SLEEP); 1681 1682 zilog->zl_header = zh_phys; 1683 zilog->zl_os = os; 1684 zilog->zl_spa = dmu_objset_spa(os); 1685 zilog->zl_dmu_pool = dmu_objset_pool(os); 1686 zilog->zl_destroy_txg = TXG_INITIAL - 1; 1687 zilog->zl_logbias = dmu_objset_logbias(os); 1688 zilog->zl_sync = dmu_objset_syncprop(os); 1689 zilog->zl_next_batch = 1; 1690 1691 mutex_init(&zilog->zl_lock, NULL, MUTEX_DEFAULT, NULL); 1692 1693 for (int i = 0; i < TXG_SIZE; i++) { 1694 mutex_init(&zilog->zl_itxg[i].itxg_lock, NULL, 1695 MUTEX_DEFAULT, NULL); 1696 } 1697 1698 list_create(&zilog->zl_lwb_list, sizeof (lwb_t), 1699 offsetof(lwb_t, lwb_node)); 1700 1701 list_create(&zilog->zl_itx_commit_list, sizeof (itx_t), 1702 offsetof(itx_t, itx_node)); 1703 1704 mutex_init(&zilog->zl_vdev_lock, NULL, MUTEX_DEFAULT, NULL); 1705 1706 avl_create(&zilog->zl_vdev_tree, zil_vdev_compare, 1707 sizeof (zil_vdev_node_t), offsetof(zil_vdev_node_t, zv_node)); 1708 1709 cv_init(&zilog->zl_cv_writer, NULL, CV_DEFAULT, NULL); 1710 cv_init(&zilog->zl_cv_suspend, NULL, CV_DEFAULT, NULL); 1711 cv_init(&zilog->zl_cv_batch[0], NULL, CV_DEFAULT, NULL); 1712 cv_init(&zilog->zl_cv_batch[1], NULL, CV_DEFAULT, NULL); 1713 1714 return (zilog); 1715} 1716 1717void 1718zil_free(zilog_t *zilog) 1719{ 1720 zilog->zl_stop_sync = 1; 1721 1722 ASSERT0(zilog->zl_suspend); 1723 ASSERT0(zilog->zl_suspending); 1724 1725 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 1726 list_destroy(&zilog->zl_lwb_list); 1727 1728 avl_destroy(&zilog->zl_vdev_tree); 1729 mutex_destroy(&zilog->zl_vdev_lock); 1730 1731 ASSERT(list_is_empty(&zilog->zl_itx_commit_list)); 1732 list_destroy(&zilog->zl_itx_commit_list); 1733 1734 for (int i = 0; i < TXG_SIZE; i++) { 1735 /* 1736 * It's possible for an itx to be generated that doesn't dirty 1737 * a txg (e.g. ztest TX_TRUNCATE). So there's no zil_clean() 1738 * callback to remove the entry. We remove those here. 1739 * 1740 * Also free up the ziltest itxs. 1741 */ 1742 if (zilog->zl_itxg[i].itxg_itxs) 1743 zil_itxg_clean(zilog->zl_itxg[i].itxg_itxs); 1744 mutex_destroy(&zilog->zl_itxg[i].itxg_lock); 1745 } 1746 1747 mutex_destroy(&zilog->zl_lock); 1748 1749 cv_destroy(&zilog->zl_cv_writer); 1750 cv_destroy(&zilog->zl_cv_suspend); 1751 cv_destroy(&zilog->zl_cv_batch[0]); 1752 cv_destroy(&zilog->zl_cv_batch[1]); 1753 1754 kmem_free(zilog, sizeof (zilog_t)); 1755} 1756 1757/* 1758 * Open an intent log. 1759 */ 1760zilog_t * 1761zil_open(objset_t *os, zil_get_data_t *get_data) 1762{ 1763 zilog_t *zilog = dmu_objset_zil(os); 1764 1765 ASSERT(zilog->zl_clean_taskq == NULL); 1766 ASSERT(zilog->zl_get_data == NULL); 1767 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 1768 1769 zilog->zl_get_data = get_data; 1770 zilog->zl_clean_taskq = taskq_create("zil_clean", 1, minclsyspri, 1771 2, 2, TASKQ_PREPOPULATE); 1772 1773 return (zilog); 1774} 1775 1776/* 1777 * Close an intent log. 1778 */ 1779void 1780zil_close(zilog_t *zilog) 1781{ 1782 lwb_t *lwb; 1783 uint64_t txg = 0; 1784 1785 zil_commit(zilog, 0); /* commit all itx */ 1786 1787 /* 1788 * The lwb_max_txg for the stubby lwb will reflect the last activity 1789 * for the zil. After a txg_wait_synced() on the txg we know all the 1790 * callbacks have occurred that may clean the zil. Only then can we 1791 * destroy the zl_clean_taskq. 1792 */ 1793 mutex_enter(&zilog->zl_lock); 1794 lwb = list_tail(&zilog->zl_lwb_list); 1795 if (lwb != NULL) 1796 txg = lwb->lwb_max_txg; 1797 mutex_exit(&zilog->zl_lock); 1798 if (txg) 1799 txg_wait_synced(zilog->zl_dmu_pool, txg); 1800 ASSERT(!zilog_is_dirty(zilog)); 1801 1802 taskq_destroy(zilog->zl_clean_taskq); 1803 zilog->zl_clean_taskq = NULL; 1804 zilog->zl_get_data = NULL; 1805 1806 /* 1807 * We should have only one LWB left on the list; remove it now. 1808 */ 1809 mutex_enter(&zilog->zl_lock); 1810 lwb = list_head(&zilog->zl_lwb_list); 1811 if (lwb != NULL) { 1812 ASSERT(lwb == list_tail(&zilog->zl_lwb_list)); 1813 list_remove(&zilog->zl_lwb_list, lwb); 1814 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 1815 kmem_cache_free(zil_lwb_cache, lwb); 1816 } 1817 mutex_exit(&zilog->zl_lock); 1818} 1819 1820static char *suspend_tag = "zil suspending"; 1821 1822/* 1823 * Suspend an intent log. While in suspended mode, we still honor 1824 * synchronous semantics, but we rely on txg_wait_synced() to do it. 1825 * On old version pools, we suspend the log briefly when taking a 1826 * snapshot so that it will have an empty intent log. 1827 * 1828 * Long holds are not really intended to be used the way we do here -- 1829 * held for such a short time. A concurrent caller of dsl_dataset_long_held() 1830 * could fail. Therefore we take pains to only put a long hold if it is 1831 * actually necessary. Fortunately, it will only be necessary if the 1832 * objset is currently mounted (or the ZVOL equivalent). In that case it 1833 * will already have a long hold, so we are not really making things any worse. 1834 * 1835 * Ideally, we would locate the existing long-holder (i.e. the zfsvfs_t or 1836 * zvol_state_t), and use their mechanism to prevent their hold from being 1837 * dropped (e.g. VFS_HOLD()). However, that would be even more pain for 1838 * very little gain. 1839 * 1840 * if cookiep == NULL, this does both the suspend & resume. 1841 * Otherwise, it returns with the dataset "long held", and the cookie 1842 * should be passed into zil_resume(). 1843 */ 1844int 1845zil_suspend(const char *osname, void **cookiep) 1846{ 1847 objset_t *os; 1848 zilog_t *zilog; 1849 const zil_header_t *zh; 1850 int error; 1851 1852 error = dmu_objset_hold(osname, suspend_tag, &os); 1853 if (error != 0) 1854 return (error); 1855 zilog = dmu_objset_zil(os); 1856 1857 mutex_enter(&zilog->zl_lock); 1858 zh = zilog->zl_header; 1859 1860 if (zh->zh_flags & ZIL_REPLAY_NEEDED) { /* unplayed log */ 1861 mutex_exit(&zilog->zl_lock); 1862 dmu_objset_rele(os, suspend_tag); 1863 return (EBUSY); 1864 } 1865 1866 /* 1867 * Don't put a long hold in the cases where we can avoid it. This 1868 * is when there is no cookie so we are doing a suspend & resume 1869 * (i.e. called from zil_vdev_offline()), and there's nothing to do 1870 * for the suspend because it's already suspended, or there's no ZIL. 1871 */ 1872 if (cookiep == NULL && !zilog->zl_suspending && 1873 (zilog->zl_suspend > 0 || BP_IS_HOLE(&zh->zh_log))) { 1874 mutex_exit(&zilog->zl_lock); 1875 dmu_objset_rele(os, suspend_tag); 1876 return (0); 1877 } 1878 1879 dsl_dataset_long_hold(dmu_objset_ds(os), suspend_tag); 1880 dsl_pool_rele(dmu_objset_pool(os), suspend_tag); 1881 1882 zilog->zl_suspend++; 1883 1884 if (zilog->zl_suspend > 1) { 1885 /* 1886 * Someone else is already suspending it. 1887 * Just wait for them to finish. 1888 */ 1889 1890 while (zilog->zl_suspending) 1891 cv_wait(&zilog->zl_cv_suspend, &zilog->zl_lock); 1892 mutex_exit(&zilog->zl_lock); 1893 1894 if (cookiep == NULL) 1895 zil_resume(os); 1896 else 1897 *cookiep = os; 1898 return (0); 1899 } 1900 1901 /* 1902 * If there is no pointer to an on-disk block, this ZIL must not 1903 * be active (e.g. filesystem not mounted), so there's nothing 1904 * to clean up. 1905 */ 1906 if (BP_IS_HOLE(&zh->zh_log)) { 1907 ASSERT(cookiep != NULL); /* fast path already handled */ 1908 1909 *cookiep = os; 1910 mutex_exit(&zilog->zl_lock); 1911 return (0); 1912 } 1913 1914 zilog->zl_suspending = B_TRUE; 1915 mutex_exit(&zilog->zl_lock); 1916 1917 zil_commit(zilog, 0); 1918 1919 zil_destroy(zilog, B_FALSE); 1920 1921 mutex_enter(&zilog->zl_lock); 1922 zilog->zl_suspending = B_FALSE; 1923 cv_broadcast(&zilog->zl_cv_suspend); 1924 mutex_exit(&zilog->zl_lock); 1925 1926 if (cookiep == NULL) 1927 zil_resume(os); 1928 else 1929 *cookiep = os; 1930 return (0); 1931} 1932 1933void 1934zil_resume(void *cookie) 1935{ 1936 objset_t *os = cookie; 1937 zilog_t *zilog = dmu_objset_zil(os); 1938 1939 mutex_enter(&zilog->zl_lock); 1940 ASSERT(zilog->zl_suspend != 0); 1941 zilog->zl_suspend--; 1942 mutex_exit(&zilog->zl_lock); 1943 dsl_dataset_long_rele(dmu_objset_ds(os), suspend_tag); 1944 dsl_dataset_rele(dmu_objset_ds(os), suspend_tag); 1945} 1946 1947typedef struct zil_replay_arg { 1948 zil_replay_func_t **zr_replay; 1949 void *zr_arg; 1950 boolean_t zr_byteswap; 1951 char *zr_lr; 1952} zil_replay_arg_t; 1953 1954static int 1955zil_replay_error(zilog_t *zilog, lr_t *lr, int error) 1956{ 1957 char name[MAXNAMELEN]; 1958 1959 zilog->zl_replaying_seq--; /* didn't actually replay this one */ 1960 1961 dmu_objset_name(zilog->zl_os, name); 1962 1963 cmn_err(CE_WARN, "ZFS replay transaction error %d, " 1964 "dataset %s, seq 0x%llx, txtype %llu %s\n", error, name, 1965 (u_longlong_t)lr->lrc_seq, 1966 (u_longlong_t)(lr->lrc_txtype & ~TX_CI), 1967 (lr->lrc_txtype & TX_CI) ? "CI" : ""); 1968 1969 return (error); 1970} 1971 1972static int 1973zil_replay_log_record(zilog_t *zilog, lr_t *lr, void *zra, uint64_t claim_txg) 1974{ 1975 zil_replay_arg_t *zr = zra; 1976 const zil_header_t *zh = zilog->zl_header; 1977 uint64_t reclen = lr->lrc_reclen; 1978 uint64_t txtype = lr->lrc_txtype; 1979 int error = 0; 1980 1981 zilog->zl_replaying_seq = lr->lrc_seq; 1982 1983 if (lr->lrc_seq <= zh->zh_replay_seq) /* already replayed */ 1984 return (0); 1985 1986 if (lr->lrc_txg < claim_txg) /* already committed */ 1987 return (0); 1988 1989 /* Strip case-insensitive bit, still present in log record */ 1990 txtype &= ~TX_CI; 1991 1992 if (txtype == 0 || txtype >= TX_MAX_TYPE) 1993 return (zil_replay_error(zilog, lr, EINVAL)); 1994 1995 /* 1996 * If this record type can be logged out of order, the object 1997 * (lr_foid) may no longer exist. That's legitimate, not an error. 1998 */ 1999 if (TX_OOO(txtype)) { 2000 error = dmu_object_info(zilog->zl_os, 2001 ((lr_ooo_t *)lr)->lr_foid, NULL); 2002 if (error == ENOENT || error == EEXIST) 2003 return (0); 2004 } 2005 2006 /* 2007 * Make a copy of the data so we can revise and extend it. 2008 */ 2009 bcopy(lr, zr->zr_lr, reclen); 2010 2011 /* 2012 * If this is a TX_WRITE with a blkptr, suck in the data. 2013 */ 2014 if (txtype == TX_WRITE && reclen == sizeof (lr_write_t)) { 2015 error = zil_read_log_data(zilog, (lr_write_t *)lr, 2016 zr->zr_lr + reclen); 2017 if (error != 0) 2018 return (zil_replay_error(zilog, lr, error)); 2019 } 2020 2021 /* 2022 * The log block containing this lr may have been byteswapped 2023 * so that we can easily examine common fields like lrc_txtype. 2024 * However, the log is a mix of different record types, and only the 2025 * replay vectors know how to byteswap their records. Therefore, if 2026 * the lr was byteswapped, undo it before invoking the replay vector. 2027 */ 2028 if (zr->zr_byteswap) 2029 byteswap_uint64_array(zr->zr_lr, reclen); 2030 2031 /* 2032 * We must now do two things atomically: replay this log record, 2033 * and update the log header sequence number to reflect the fact that 2034 * we did so. At the end of each replay function the sequence number 2035 * is updated if we are in replay mode. 2036 */ 2037 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, zr->zr_byteswap); 2038 if (error != 0) { 2039 /* 2040 * The DMU's dnode layer doesn't see removes until the txg 2041 * commits, so a subsequent claim can spuriously fail with 2042 * EEXIST. So if we receive any error we try syncing out 2043 * any removes then retry the transaction. Note that we 2044 * specify B_FALSE for byteswap now, so we don't do it twice. 2045 */ 2046 txg_wait_synced(spa_get_dsl(zilog->zl_spa), 0); 2047 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, B_FALSE); 2048 if (error != 0) 2049 return (zil_replay_error(zilog, lr, error)); 2050 } 2051 return (0); 2052} 2053 2054/* ARGSUSED */ 2055static int 2056zil_incr_blks(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg) 2057{ 2058 zilog->zl_replay_blks++; 2059 2060 return (0); 2061} 2062 2063/* 2064 * If this dataset has a non-empty intent log, replay it and destroy it. 2065 */ 2066void 2067zil_replay(objset_t *os, void *arg, zil_replay_func_t *replay_func[TX_MAX_TYPE]) 2068{ 2069 zilog_t *zilog = dmu_objset_zil(os); 2070 const zil_header_t *zh = zilog->zl_header; 2071 zil_replay_arg_t zr; 2072 2073 if ((zh->zh_flags & ZIL_REPLAY_NEEDED) == 0) { 2074 zil_destroy(zilog, B_TRUE); 2075 return; 2076 } 2077 //printf("ZFS: Replaying ZIL on %s...\n", os->os->os_spa->spa_name); 2078 2079 zr.zr_replay = replay_func; 2080 zr.zr_arg = arg; 2081 zr.zr_byteswap = BP_SHOULD_BYTESWAP(&zh->zh_log); 2082 zr.zr_lr = kmem_alloc(2 * SPA_MAXBLOCKSIZE, KM_SLEEP); 2083 2084 /* 2085 * Wait for in-progress removes to sync before starting replay. 2086 */ 2087 txg_wait_synced(zilog->zl_dmu_pool, 0); 2088 2089 zilog->zl_replay = B_TRUE; 2090 zilog->zl_replay_time = ddi_get_lbolt(); 2091 ASSERT(zilog->zl_replay_blks == 0); 2092 (void) zil_parse(zilog, zil_incr_blks, zil_replay_log_record, &zr, 2093 zh->zh_claim_txg); 2094 kmem_free(zr.zr_lr, 2 * SPA_MAXBLOCKSIZE); 2095 2096 zil_destroy(zilog, B_FALSE); 2097 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 2098 zilog->zl_replay = B_FALSE; 2099 //printf("ZFS: Replay of ZIL on %s finished.\n", os->os->os_spa->spa_name); 2100} 2101 2102boolean_t 2103zil_replaying(zilog_t *zilog, dmu_tx_t *tx) 2104{ 2105 if (zilog->zl_sync == ZFS_SYNC_DISABLED) 2106 return (B_TRUE); 2107 2108 if (zilog->zl_replay) { 2109 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 2110 zilog->zl_replayed_seq[dmu_tx_get_txg(tx) & TXG_MASK] = 2111 zilog->zl_replaying_seq; 2112 return (B_TRUE); 2113 } 2114 2115 return (B_FALSE); 2116} 2117 2118/* ARGSUSED */ 2119int 2120zil_vdev_offline(const char *osname, void *arg) 2121{ 2122 int error; 2123 2124 error = zil_suspend(osname, NULL); 2125 if (error != 0) 2126 return (EEXIST); 2127 return (0); 2128} 2129