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, 2017 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 #include <sys/abd.h> 43 44 /* 45 * The zfs intent log (ZIL) saves transaction records of system calls 46 * that change the file system in memory with enough information 47 * to be able to replay them. These are stored in memory until 48 * either the DMU transaction group (txg) commits them to the stable pool 49 * and they can be discarded, or they are flushed to the stable log 50 * (also in the pool) due to a fsync, O_DSYNC or other synchronous 51 * requirement. In the event of a panic or power fail then those log 52 * records (transactions) are replayed. 53 * 54 * There is one ZIL per file system. Its on-disk (pool) format consists 55 * of 3 parts: 56 * 57 * - ZIL header 58 * - ZIL blocks 59 * - ZIL records 60 * 61 * A log record holds a system call transaction. Log blocks can 62 * hold many log records and the blocks are chained together. 63 * Each ZIL block contains a block pointer (blkptr_t) to the next 64 * ZIL block in the chain. The ZIL header points to the first 65 * block in the chain. Note there is not a fixed place in the pool 66 * to hold blocks. They are dynamically allocated and freed as 67 * needed from the blocks available. Figure X shows the ZIL structure: 68 */ 69 70 /* 71 * Disable intent logging replay. This global ZIL switch affects all pools. 72 */ 73 int zil_replay_disable = 0; 74 75 /* 76 * Tunable parameter for debugging or performance analysis. Setting 77 * zfs_nocacheflush will cause corruption on power loss if a volatile 78 * out-of-order write cache is enabled. 79 */ 80 boolean_t zfs_nocacheflush = B_FALSE; 81 82 /* 83 * Limit SLOG write size per commit executed with synchronous priority. 84 * Any writes above that will be executed with lower (asynchronous) priority 85 * to limit potential SLOG device abuse by single active ZIL writer. 86 */ 87 uint64_t zil_slog_bulk = 768 * 1024; 88 89 static kmem_cache_t *zil_lwb_cache; 90 91 static void zil_async_to_sync(zilog_t *zilog, uint64_t foid); 92 93 #define LWB_EMPTY(lwb) ((BP_GET_LSIZE(&lwb->lwb_blk) - \ 94 sizeof (zil_chain_t)) == (lwb->lwb_sz - lwb->lwb_nused)) 95 96 static int 97 zil_bp_compare(const void *x1, const void *x2) 98 { 99 const dva_t *dva1 = &((zil_bp_node_t *)x1)->zn_dva; 100 const dva_t *dva2 = &((zil_bp_node_t *)x2)->zn_dva; 101 102 if (DVA_GET_VDEV(dva1) < DVA_GET_VDEV(dva2)) 103 return (-1); 104 if (DVA_GET_VDEV(dva1) > DVA_GET_VDEV(dva2)) 105 return (1); 106 107 if (DVA_GET_OFFSET(dva1) < DVA_GET_OFFSET(dva2)) 108 return (-1); 109 if (DVA_GET_OFFSET(dva1) > DVA_GET_OFFSET(dva2)) 110 return (1); 111 112 return (0); 113 } 114 115 static void 116 zil_bp_tree_init(zilog_t *zilog) 117 { 118 avl_create(&zilog->zl_bp_tree, zil_bp_compare, 119 sizeof (zil_bp_node_t), offsetof(zil_bp_node_t, zn_node)); 120 } 121 122 static void 123 zil_bp_tree_fini(zilog_t *zilog) 124 { 125 avl_tree_t *t = &zilog->zl_bp_tree; 126 zil_bp_node_t *zn; 127 void *cookie = NULL; 128 129 while ((zn = avl_destroy_nodes(t, &cookie)) != NULL) 130 kmem_free(zn, sizeof (zil_bp_node_t)); 131 132 avl_destroy(t); 133 } 134 135 int 136 zil_bp_tree_add(zilog_t *zilog, const blkptr_t *bp) 137 { 138 avl_tree_t *t = &zilog->zl_bp_tree; 139 const dva_t *dva; 140 zil_bp_node_t *zn; 141 avl_index_t where; 142 143 if (BP_IS_EMBEDDED(bp)) 144 return (0); 145 146 dva = BP_IDENTITY(bp); 147 148 if (avl_find(t, dva, &where) != NULL) 149 return (SET_ERROR(EEXIST)); 150 151 zn = kmem_alloc(sizeof (zil_bp_node_t), KM_SLEEP); 152 zn->zn_dva = *dva; 153 avl_insert(t, zn, where); 154 155 return (0); 156 } 157 158 static zil_header_t * 159 zil_header_in_syncing_context(zilog_t *zilog) 160 { 161 return ((zil_header_t *)zilog->zl_header); 162 } 163 164 static void 165 zil_init_log_chain(zilog_t *zilog, blkptr_t *bp) 166 { 167 zio_cksum_t *zc = &bp->blk_cksum; 168 169 zc->zc_word[ZIL_ZC_GUID_0] = spa_get_random(-1ULL); 170 zc->zc_word[ZIL_ZC_GUID_1] = spa_get_random(-1ULL); 171 zc->zc_word[ZIL_ZC_OBJSET] = dmu_objset_id(zilog->zl_os); 172 zc->zc_word[ZIL_ZC_SEQ] = 1ULL; 173 } 174 175 /* 176 * Read a log block and make sure it's valid. 177 */ 178 static int 179 zil_read_log_block(zilog_t *zilog, const blkptr_t *bp, blkptr_t *nbp, void *dst, 180 char **end) 181 { 182 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL; 183 arc_flags_t aflags = ARC_FLAG_WAIT; 184 arc_buf_t *abuf = NULL; 185 zbookmark_phys_t zb; 186 int error; 187 188 if (zilog->zl_header->zh_claim_txg == 0) 189 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; 190 191 if (!(zilog->zl_header->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) 192 zio_flags |= ZIO_FLAG_SPECULATIVE; 193 194 SET_BOOKMARK(&zb, bp->blk_cksum.zc_word[ZIL_ZC_OBJSET], 195 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]); 196 197 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf, 198 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); 199 200 if (error == 0) { 201 zio_cksum_t cksum = bp->blk_cksum; 202 203 /* 204 * Validate the checksummed log block. 205 * 206 * Sequence numbers should be... sequential. The checksum 207 * verifier for the next block should be bp's checksum plus 1. 208 * 209 * Also check the log chain linkage and size used. 210 */ 211 cksum.zc_word[ZIL_ZC_SEQ]++; 212 213 if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) { 214 zil_chain_t *zilc = abuf->b_data; 215 char *lr = (char *)(zilc + 1); 216 uint64_t len = zilc->zc_nused - sizeof (zil_chain_t); 217 218 if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum, 219 sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk)) { 220 error = SET_ERROR(ECKSUM); 221 } else { 222 ASSERT3U(len, <=, SPA_OLD_MAXBLOCKSIZE); 223 bcopy(lr, dst, len); 224 *end = (char *)dst + len; 225 *nbp = zilc->zc_next_blk; 226 } 227 } else { 228 char *lr = abuf->b_data; 229 uint64_t size = BP_GET_LSIZE(bp); 230 zil_chain_t *zilc = (zil_chain_t *)(lr + size) - 1; 231 232 if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum, 233 sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk) || 234 (zilc->zc_nused > (size - sizeof (*zilc)))) { 235 error = SET_ERROR(ECKSUM); 236 } else { 237 ASSERT3U(zilc->zc_nused, <=, 238 SPA_OLD_MAXBLOCKSIZE); 239 bcopy(lr, dst, zilc->zc_nused); 240 *end = (char *)dst + zilc->zc_nused; 241 *nbp = zilc->zc_next_blk; 242 } 243 } 244 245 arc_buf_destroy(abuf, &abuf); 246 } 247 248 return (error); 249 } 250 251 /* 252 * Read a TX_WRITE log data block. 253 */ 254 static int 255 zil_read_log_data(zilog_t *zilog, const lr_write_t *lr, void *wbuf) 256 { 257 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL; 258 const blkptr_t *bp = &lr->lr_blkptr; 259 arc_flags_t aflags = ARC_FLAG_WAIT; 260 arc_buf_t *abuf = NULL; 261 zbookmark_phys_t zb; 262 int error; 263 264 if (BP_IS_HOLE(bp)) { 265 if (wbuf != NULL) 266 bzero(wbuf, MAX(BP_GET_LSIZE(bp), lr->lr_length)); 267 return (0); 268 } 269 270 if (zilog->zl_header->zh_claim_txg == 0) 271 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; 272 273 SET_BOOKMARK(&zb, dmu_objset_id(zilog->zl_os), lr->lr_foid, 274 ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp)); 275 276 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf, 277 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); 278 279 if (error == 0) { 280 if (wbuf != NULL) 281 bcopy(abuf->b_data, wbuf, arc_buf_size(abuf)); 282 arc_buf_destroy(abuf, &abuf); 283 } 284 285 return (error); 286 } 287 288 /* 289 * Parse the intent log, and call parse_func for each valid record within. 290 */ 291 int 292 zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func, 293 zil_parse_lr_func_t *parse_lr_func, void *arg, uint64_t txg) 294 { 295 const zil_header_t *zh = zilog->zl_header; 296 boolean_t claimed = !!zh->zh_claim_txg; 297 uint64_t claim_blk_seq = claimed ? zh->zh_claim_blk_seq : UINT64_MAX; 298 uint64_t claim_lr_seq = claimed ? zh->zh_claim_lr_seq : UINT64_MAX; 299 uint64_t max_blk_seq = 0; 300 uint64_t max_lr_seq = 0; 301 uint64_t blk_count = 0; 302 uint64_t lr_count = 0; 303 blkptr_t blk, next_blk; 304 char *lrbuf, *lrp; 305 int error = 0; 306 307 /* 308 * Old logs didn't record the maximum zh_claim_lr_seq. 309 */ 310 if (!(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) 311 claim_lr_seq = UINT64_MAX; 312 313 /* 314 * Starting at the block pointed to by zh_log we read the log chain. 315 * For each block in the chain we strongly check that block to 316 * ensure its validity. We stop when an invalid block is found. 317 * For each block pointer in the chain we call parse_blk_func(). 318 * For each record in each valid block we call parse_lr_func(). 319 * If the log has been claimed, stop if we encounter a sequence 320 * number greater than the highest claimed sequence number. 321 */ 322 lrbuf = zio_buf_alloc(SPA_OLD_MAXBLOCKSIZE); 323 zil_bp_tree_init(zilog); 324 325 for (blk = zh->zh_log; !BP_IS_HOLE(&blk); blk = next_blk) { 326 uint64_t blk_seq = blk.blk_cksum.zc_word[ZIL_ZC_SEQ]; 327 int reclen; 328 char *end; 329 330 if (blk_seq > claim_blk_seq) 331 break; 332 if ((error = parse_blk_func(zilog, &blk, arg, txg)) != 0) 333 break; 334 ASSERT3U(max_blk_seq, <, blk_seq); 335 max_blk_seq = blk_seq; 336 blk_count++; 337 338 if (max_lr_seq == claim_lr_seq && max_blk_seq == claim_blk_seq) 339 break; 340 341 error = zil_read_log_block(zilog, &blk, &next_blk, lrbuf, &end); 342 if (error != 0) 343 break; 344 345 for (lrp = lrbuf; lrp < end; lrp += reclen) { 346 lr_t *lr = (lr_t *)lrp; 347 reclen = lr->lrc_reclen; 348 ASSERT3U(reclen, >=, sizeof (lr_t)); 349 if (lr->lrc_seq > claim_lr_seq) 350 goto done; 351 if ((error = parse_lr_func(zilog, lr, arg, txg)) != 0) 352 goto done; 353 ASSERT3U(max_lr_seq, <, lr->lrc_seq); 354 max_lr_seq = lr->lrc_seq; 355 lr_count++; 356 } 357 } 358 done: 359 zilog->zl_parse_error = error; 360 zilog->zl_parse_blk_seq = max_blk_seq; 361 zilog->zl_parse_lr_seq = max_lr_seq; 362 zilog->zl_parse_blk_count = blk_count; 363 zilog->zl_parse_lr_count = lr_count; 364 365 ASSERT(!claimed || !(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID) || 366 (max_blk_seq == claim_blk_seq && max_lr_seq == claim_lr_seq)); 367 368 zil_bp_tree_fini(zilog); 369 zio_buf_free(lrbuf, SPA_OLD_MAXBLOCKSIZE); 370 371 return (error); 372 } 373 374 static int 375 zil_claim_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t first_txg) 376 { 377 /* 378 * Claim log block if not already committed and not already claimed. 379 * If tx == NULL, just verify that the block is claimable. 380 */ 381 if (BP_IS_HOLE(bp) || bp->blk_birth < first_txg || 382 zil_bp_tree_add(zilog, bp) != 0) 383 return (0); 384 385 return (zio_wait(zio_claim(NULL, zilog->zl_spa, 386 tx == NULL ? 0 : first_txg, bp, spa_claim_notify, NULL, 387 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB))); 388 } 389 390 static int 391 zil_claim_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t first_txg) 392 { 393 lr_write_t *lr = (lr_write_t *)lrc; 394 int error; 395 396 if (lrc->lrc_txtype != TX_WRITE) 397 return (0); 398 399 /* 400 * If the block is not readable, don't claim it. This can happen 401 * in normal operation when a log block is written to disk before 402 * some of the dmu_sync() blocks it points to. In this case, the 403 * transaction cannot have been committed to anyone (we would have 404 * waited for all writes to be stable first), so it is semantically 405 * correct to declare this the end of the log. 406 */ 407 if (lr->lr_blkptr.blk_birth >= first_txg && 408 (error = zil_read_log_data(zilog, lr, NULL)) != 0) 409 return (error); 410 return (zil_claim_log_block(zilog, &lr->lr_blkptr, tx, first_txg)); 411 } 412 413 /* ARGSUSED */ 414 static int 415 zil_free_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t claim_txg) 416 { 417 zio_free_zil(zilog->zl_spa, dmu_tx_get_txg(tx), bp); 418 419 return (0); 420 } 421 422 static int 423 zil_free_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t claim_txg) 424 { 425 lr_write_t *lr = (lr_write_t *)lrc; 426 blkptr_t *bp = &lr->lr_blkptr; 427 428 /* 429 * If we previously claimed it, we need to free it. 430 */ 431 if (claim_txg != 0 && lrc->lrc_txtype == TX_WRITE && 432 bp->blk_birth >= claim_txg && zil_bp_tree_add(zilog, bp) == 0 && 433 !BP_IS_HOLE(bp)) 434 zio_free(zilog->zl_spa, dmu_tx_get_txg(tx), bp); 435 436 return (0); 437 } 438 439 static lwb_t * 440 zil_alloc_lwb(zilog_t *zilog, blkptr_t *bp, boolean_t slog, uint64_t txg) 441 { 442 lwb_t *lwb; 443 444 lwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP); 445 lwb->lwb_zilog = zilog; 446 lwb->lwb_blk = *bp; 447 lwb->lwb_slog = slog; 448 lwb->lwb_buf = zio_buf_alloc(BP_GET_LSIZE(bp)); 449 lwb->lwb_max_txg = txg; 450 lwb->lwb_zio = NULL; 451 lwb->lwb_tx = NULL; 452 if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) { 453 lwb->lwb_nused = sizeof (zil_chain_t); 454 lwb->lwb_sz = BP_GET_LSIZE(bp); 455 } else { 456 lwb->lwb_nused = 0; 457 lwb->lwb_sz = BP_GET_LSIZE(bp) - sizeof (zil_chain_t); 458 } 459 460 mutex_enter(&zilog->zl_lock); 461 list_insert_tail(&zilog->zl_lwb_list, lwb); 462 mutex_exit(&zilog->zl_lock); 463 464 return (lwb); 465 } 466 467 /* 468 * Called when we create in-memory log transactions so that we know 469 * to cleanup the itxs at the end of spa_sync(). 470 */ 471 void 472 zilog_dirty(zilog_t *zilog, uint64_t txg) 473 { 474 dsl_pool_t *dp = zilog->zl_dmu_pool; 475 dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os); 476 477 if (ds->ds_is_snapshot) 478 panic("dirtying snapshot!"); 479 480 if (txg_list_add(&dp->dp_dirty_zilogs, zilog, txg)) { 481 /* up the hold count until we can be written out */ 482 dmu_buf_add_ref(ds->ds_dbuf, zilog); 483 } 484 } 485 486 /* 487 * Determine if the zil is dirty in the specified txg. Callers wanting to 488 * ensure that the dirty state does not change must hold the itxg_lock for 489 * the specified txg. Holding the lock will ensure that the zil cannot be 490 * dirtied (zil_itx_assign) or cleaned (zil_clean) while we check its current 491 * state. 492 */ 493 boolean_t 494 zilog_is_dirty_in_txg(zilog_t *zilog, uint64_t txg) 495 { 496 dsl_pool_t *dp = zilog->zl_dmu_pool; 497 498 if (txg_list_member(&dp->dp_dirty_zilogs, zilog, txg & TXG_MASK)) 499 return (B_TRUE); 500 return (B_FALSE); 501 } 502 503 /* 504 * Determine if the zil is dirty. The zil is considered dirty if it has 505 * any pending itx records that have not been cleaned by zil_clean(). 506 */ 507 boolean_t 508 zilog_is_dirty(zilog_t *zilog) 509 { 510 dsl_pool_t *dp = zilog->zl_dmu_pool; 511 512 for (int t = 0; t < TXG_SIZE; t++) { 513 if (txg_list_member(&dp->dp_dirty_zilogs, zilog, t)) 514 return (B_TRUE); 515 } 516 return (B_FALSE); 517 } 518 519 /* 520 * Create an on-disk intent log. 521 */ 522 static lwb_t * 523 zil_create(zilog_t *zilog) 524 { 525 const zil_header_t *zh = zilog->zl_header; 526 lwb_t *lwb = NULL; 527 uint64_t txg = 0; 528 dmu_tx_t *tx = NULL; 529 blkptr_t blk; 530 int error = 0; 531 boolean_t slog = FALSE; 532 533 /* 534 * Wait for any previous destroy to complete. 535 */ 536 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 537 538 ASSERT(zh->zh_claim_txg == 0); 539 ASSERT(zh->zh_replay_seq == 0); 540 541 blk = zh->zh_log; 542 543 /* 544 * Allocate an initial log block if: 545 * - there isn't one already 546 * - the existing block is the wrong endianess 547 */ 548 if (BP_IS_HOLE(&blk) || BP_SHOULD_BYTESWAP(&blk)) { 549 tx = dmu_tx_create(zilog->zl_os); 550 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 551 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 552 txg = dmu_tx_get_txg(tx); 553 554 if (!BP_IS_HOLE(&blk)) { 555 zio_free_zil(zilog->zl_spa, txg, &blk); 556 BP_ZERO(&blk); 557 } 558 559 error = zio_alloc_zil(zilog->zl_spa, txg, &blk, NULL, 560 ZIL_MIN_BLKSZ, &slog); 561 562 if (error == 0) 563 zil_init_log_chain(zilog, &blk); 564 } 565 566 /* 567 * Allocate a log write buffer (lwb) for the first log block. 568 */ 569 if (error == 0) 570 lwb = zil_alloc_lwb(zilog, &blk, slog, txg); 571 572 /* 573 * If we just allocated the first log block, commit our transaction 574 * and wait for zil_sync() to stuff the block poiner into zh_log. 575 * (zh is part of the MOS, so we cannot modify it in open context.) 576 */ 577 if (tx != NULL) { 578 dmu_tx_commit(tx); 579 txg_wait_synced(zilog->zl_dmu_pool, txg); 580 } 581 582 ASSERT(bcmp(&blk, &zh->zh_log, sizeof (blk)) == 0); 583 584 return (lwb); 585 } 586 587 /* 588 * In one tx, free all log blocks and clear the log header. 589 * If keep_first is set, then we're replaying a log with no content. 590 * We want to keep the first block, however, so that the first 591 * synchronous transaction doesn't require a txg_wait_synced() 592 * in zil_create(). We don't need to txg_wait_synced() here either 593 * when keep_first is set, because both zil_create() and zil_destroy() 594 * will wait for any in-progress destroys to complete. 595 */ 596 void 597 zil_destroy(zilog_t *zilog, boolean_t keep_first) 598 { 599 const zil_header_t *zh = zilog->zl_header; 600 lwb_t *lwb; 601 dmu_tx_t *tx; 602 uint64_t txg; 603 604 /* 605 * Wait for any previous destroy to complete. 606 */ 607 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 608 609 zilog->zl_old_header = *zh; /* debugging aid */ 610 611 if (BP_IS_HOLE(&zh->zh_log)) 612 return; 613 614 tx = dmu_tx_create(zilog->zl_os); 615 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 616 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 617 txg = dmu_tx_get_txg(tx); 618 619 mutex_enter(&zilog->zl_lock); 620 621 ASSERT3U(zilog->zl_destroy_txg, <, txg); 622 zilog->zl_destroy_txg = txg; 623 zilog->zl_keep_first = keep_first; 624 625 if (!list_is_empty(&zilog->zl_lwb_list)) { 626 ASSERT(zh->zh_claim_txg == 0); 627 VERIFY(!keep_first); 628 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { 629 list_remove(&zilog->zl_lwb_list, lwb); 630 if (lwb->lwb_buf != NULL) 631 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 632 zio_free_zil(zilog->zl_spa, txg, &lwb->lwb_blk); 633 kmem_cache_free(zil_lwb_cache, lwb); 634 } 635 } else if (!keep_first) { 636 zil_destroy_sync(zilog, tx); 637 } 638 mutex_exit(&zilog->zl_lock); 639 640 dmu_tx_commit(tx); 641 } 642 643 void 644 zil_destroy_sync(zilog_t *zilog, dmu_tx_t *tx) 645 { 646 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 647 (void) zil_parse(zilog, zil_free_log_block, 648 zil_free_log_record, tx, zilog->zl_header->zh_claim_txg); 649 } 650 651 int 652 zil_claim(dsl_pool_t *dp, dsl_dataset_t *ds, void *txarg) 653 { 654 dmu_tx_t *tx = txarg; 655 uint64_t first_txg = dmu_tx_get_txg(tx); 656 zilog_t *zilog; 657 zil_header_t *zh; 658 objset_t *os; 659 int error; 660 661 error = dmu_objset_own_obj(dp, ds->ds_object, 662 DMU_OST_ANY, B_FALSE, FTAG, &os); 663 if (error != 0) { 664 /* 665 * EBUSY indicates that the objset is inconsistent, in which 666 * case it can not have a ZIL. 667 */ 668 if (error != EBUSY) { 669 cmn_err(CE_WARN, "can't open objset for %llu, error %u", 670 (unsigned long long)ds->ds_object, error); 671 } 672 return (0); 673 } 674 675 zilog = dmu_objset_zil(os); 676 zh = zil_header_in_syncing_context(zilog); 677 678 if (spa_get_log_state(zilog->zl_spa) == SPA_LOG_CLEAR) { 679 if (!BP_IS_HOLE(&zh->zh_log)) 680 zio_free_zil(zilog->zl_spa, first_txg, &zh->zh_log); 681 BP_ZERO(&zh->zh_log); 682 dsl_dataset_dirty(dmu_objset_ds(os), tx); 683 dmu_objset_disown(os, FTAG); 684 return (0); 685 } 686 687 /* 688 * Claim all log blocks if we haven't already done so, and remember 689 * the highest claimed sequence number. This ensures that if we can 690 * read only part of the log now (e.g. due to a missing device), 691 * but we can read the entire log later, we will not try to replay 692 * or destroy beyond the last block we successfully claimed. 693 */ 694 ASSERT3U(zh->zh_claim_txg, <=, first_txg); 695 if (zh->zh_claim_txg == 0 && !BP_IS_HOLE(&zh->zh_log)) { 696 (void) zil_parse(zilog, zil_claim_log_block, 697 zil_claim_log_record, tx, first_txg); 698 zh->zh_claim_txg = first_txg; 699 zh->zh_claim_blk_seq = zilog->zl_parse_blk_seq; 700 zh->zh_claim_lr_seq = zilog->zl_parse_lr_seq; 701 if (zilog->zl_parse_lr_count || zilog->zl_parse_blk_count > 1) 702 zh->zh_flags |= ZIL_REPLAY_NEEDED; 703 zh->zh_flags |= ZIL_CLAIM_LR_SEQ_VALID; 704 dsl_dataset_dirty(dmu_objset_ds(os), tx); 705 } 706 707 ASSERT3U(first_txg, ==, (spa_last_synced_txg(zilog->zl_spa) + 1)); 708 dmu_objset_disown(os, FTAG); 709 return (0); 710 } 711 712 /* 713 * Check the log by walking the log chain. 714 * Checksum errors are ok as they indicate the end of the chain. 715 * Any other error (no device or read failure) returns an error. 716 */ 717 /* ARGSUSED */ 718 int 719 zil_check_log_chain(dsl_pool_t *dp, dsl_dataset_t *ds, void *tx) 720 { 721 zilog_t *zilog; 722 objset_t *os; 723 blkptr_t *bp; 724 int error; 725 726 ASSERT(tx == NULL); 727 728 error = dmu_objset_from_ds(ds, &os); 729 if (error != 0) { 730 cmn_err(CE_WARN, "can't open objset %llu, error %d", 731 (unsigned long long)ds->ds_object, error); 732 return (0); 733 } 734 735 zilog = dmu_objset_zil(os); 736 bp = (blkptr_t *)&zilog->zl_header->zh_log; 737 738 /* 739 * Check the first block and determine if it's on a log device 740 * which may have been removed or faulted prior to loading this 741 * pool. If so, there's no point in checking the rest of the log 742 * as its content should have already been synced to the pool. 743 */ 744 if (!BP_IS_HOLE(bp)) { 745 vdev_t *vd; 746 boolean_t valid = B_TRUE; 747 748 spa_config_enter(os->os_spa, SCL_STATE, FTAG, RW_READER); 749 vd = vdev_lookup_top(os->os_spa, DVA_GET_VDEV(&bp->blk_dva[0])); 750 if (vd->vdev_islog && vdev_is_dead(vd)) 751 valid = vdev_log_state_valid(vd); 752 spa_config_exit(os->os_spa, SCL_STATE, FTAG); 753 754 if (!valid) 755 return (0); 756 } 757 758 /* 759 * Because tx == NULL, zil_claim_log_block() will not actually claim 760 * any blocks, but just determine whether it is possible to do so. 761 * In addition to checking the log chain, zil_claim_log_block() 762 * will invoke zio_claim() with a done func of spa_claim_notify(), 763 * which will update spa_max_claim_txg. See spa_load() for details. 764 */ 765 error = zil_parse(zilog, zil_claim_log_block, zil_claim_log_record, tx, 766 zilog->zl_header->zh_claim_txg ? -1ULL : spa_first_txg(os->os_spa)); 767 768 return ((error == ECKSUM || error == ENOENT) ? 0 : error); 769 } 770 771 static int 772 zil_vdev_compare(const void *x1, const void *x2) 773 { 774 const uint64_t v1 = ((zil_vdev_node_t *)x1)->zv_vdev; 775 const uint64_t v2 = ((zil_vdev_node_t *)x2)->zv_vdev; 776 777 if (v1 < v2) 778 return (-1); 779 if (v1 > v2) 780 return (1); 781 782 return (0); 783 } 784 785 void 786 zil_add_block(zilog_t *zilog, const blkptr_t *bp) 787 { 788 avl_tree_t *t = &zilog->zl_vdev_tree; 789 avl_index_t where; 790 zil_vdev_node_t *zv, zvsearch; 791 int ndvas = BP_GET_NDVAS(bp); 792 int i; 793 794 if (zfs_nocacheflush) 795 return; 796 797 ASSERT(zilog->zl_writer); 798 799 /* 800 * Even though we're zl_writer, we still need a lock because the 801 * zl_get_data() callbacks may have dmu_sync() done callbacks 802 * that will run concurrently. 803 */ 804 mutex_enter(&zilog->zl_vdev_lock); 805 for (i = 0; i < ndvas; i++) { 806 zvsearch.zv_vdev = DVA_GET_VDEV(&bp->blk_dva[i]); 807 if (avl_find(t, &zvsearch, &where) == NULL) { 808 zv = kmem_alloc(sizeof (*zv), KM_SLEEP); 809 zv->zv_vdev = zvsearch.zv_vdev; 810 avl_insert(t, zv, where); 811 } 812 } 813 mutex_exit(&zilog->zl_vdev_lock); 814 } 815 816 static void 817 zil_flush_vdevs(zilog_t *zilog) 818 { 819 spa_t *spa = zilog->zl_spa; 820 avl_tree_t *t = &zilog->zl_vdev_tree; 821 void *cookie = NULL; 822 zil_vdev_node_t *zv; 823 zio_t *zio; 824 825 ASSERT(zilog->zl_writer); 826 827 /* 828 * We don't need zl_vdev_lock here because we're the zl_writer, 829 * and all zl_get_data() callbacks are done. 830 */ 831 if (avl_numnodes(t) == 0) 832 return; 833 834 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER); 835 836 zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL); 837 838 while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) { 839 vdev_t *vd = vdev_lookup_top(spa, zv->zv_vdev); 840 if (vd != NULL) 841 zio_flush(zio, vd); 842 kmem_free(zv, sizeof (*zv)); 843 } 844 845 /* 846 * Wait for all the flushes to complete. Not all devices actually 847 * support the DKIOCFLUSHWRITECACHE ioctl, so it's OK if it fails. 848 */ 849 (void) zio_wait(zio); 850 851 spa_config_exit(spa, SCL_STATE, FTAG); 852 } 853 854 /* 855 * Function called when a log block write completes 856 */ 857 static void 858 zil_lwb_write_done(zio_t *zio) 859 { 860 lwb_t *lwb = zio->io_private; 861 zilog_t *zilog = lwb->lwb_zilog; 862 dmu_tx_t *tx = lwb->lwb_tx; 863 864 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 865 ASSERT(BP_GET_TYPE(zio->io_bp) == DMU_OT_INTENT_LOG); 866 ASSERT(BP_GET_LEVEL(zio->io_bp) == 0); 867 ASSERT(BP_GET_BYTEORDER(zio->io_bp) == ZFS_HOST_BYTEORDER); 868 ASSERT(!BP_IS_GANG(zio->io_bp)); 869 ASSERT(!BP_IS_HOLE(zio->io_bp)); 870 ASSERT(BP_GET_FILL(zio->io_bp) == 0); 871 872 /* 873 * Ensure the lwb buffer pointer is cleared before releasing 874 * the txg. If we have had an allocation failure and 875 * the txg is waiting to sync then we want want zil_sync() 876 * to remove the lwb so that it's not picked up as the next new 877 * one in zil_commit_writer(). zil_sync() will only remove 878 * the lwb if lwb_buf is null. 879 */ 880 abd_put(zio->io_abd); 881 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 882 mutex_enter(&zilog->zl_lock); 883 lwb->lwb_buf = NULL; 884 lwb->lwb_tx = NULL; 885 mutex_exit(&zilog->zl_lock); 886 887 /* 888 * Now that we've written this log block, we have a stable pointer 889 * to the next block in the chain, so it's OK to let the txg in 890 * which we allocated the next block sync. 891 */ 892 dmu_tx_commit(tx); 893 } 894 895 /* 896 * Initialize the io for a log block. 897 */ 898 static void 899 zil_lwb_write_init(zilog_t *zilog, lwb_t *lwb) 900 { 901 zbookmark_phys_t zb; 902 zio_priority_t prio; 903 904 SET_BOOKMARK(&zb, lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_OBJSET], 905 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, 906 lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_SEQ]); 907 908 if (zilog->zl_root_zio == NULL) { 909 zilog->zl_root_zio = zio_root(zilog->zl_spa, NULL, NULL, 910 ZIO_FLAG_CANFAIL); 911 } 912 if (lwb->lwb_zio == NULL) { 913 abd_t *lwb_abd = abd_get_from_buf(lwb->lwb_buf, 914 BP_GET_LSIZE(&lwb->lwb_blk)); 915 if (!lwb->lwb_slog || zilog->zl_cur_used <= zil_slog_bulk) 916 prio = ZIO_PRIORITY_SYNC_WRITE; 917 else 918 prio = ZIO_PRIORITY_ASYNC_WRITE; 919 lwb->lwb_zio = zio_rewrite(zilog->zl_root_zio, zilog->zl_spa, 920 0, &lwb->lwb_blk, lwb_abd, BP_GET_LSIZE(&lwb->lwb_blk), 921 zil_lwb_write_done, lwb, prio, 922 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE, &zb); 923 } 924 } 925 926 /* 927 * Define a limited set of intent log block sizes. 928 * 929 * These must be a multiple of 4KB. Note only the amount used (again 930 * aligned to 4KB) actually gets written. However, we can't always just 931 * allocate SPA_OLD_MAXBLOCKSIZE as the slog space could be exhausted. 932 */ 933 uint64_t zil_block_buckets[] = { 934 4096, /* non TX_WRITE */ 935 8192+4096, /* data base */ 936 32*1024 + 4096, /* NFS writes */ 937 UINT64_MAX 938 }; 939 940 /* 941 * Start a log block write and advance to the next log block. 942 * Calls are serialized. 943 */ 944 static lwb_t * 945 zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb) 946 { 947 lwb_t *nlwb = NULL; 948 zil_chain_t *zilc; 949 spa_t *spa = zilog->zl_spa; 950 blkptr_t *bp; 951 dmu_tx_t *tx; 952 uint64_t txg; 953 uint64_t zil_blksz, wsz; 954 int i, error; 955 boolean_t slog; 956 957 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) { 958 zilc = (zil_chain_t *)lwb->lwb_buf; 959 bp = &zilc->zc_next_blk; 960 } else { 961 zilc = (zil_chain_t *)(lwb->lwb_buf + lwb->lwb_sz); 962 bp = &zilc->zc_next_blk; 963 } 964 965 ASSERT(lwb->lwb_nused <= lwb->lwb_sz); 966 967 /* 968 * Allocate the next block and save its address in this block 969 * before writing it in order to establish the log chain. 970 * Note that if the allocation of nlwb synced before we wrote 971 * the block that points at it (lwb), we'd leak it if we crashed. 972 * Therefore, we don't do dmu_tx_commit() until zil_lwb_write_done(). 973 * We dirty the dataset to ensure that zil_sync() will be called 974 * to clean up in the event of allocation failure or I/O failure. 975 */ 976 tx = dmu_tx_create(zilog->zl_os); 977 978 /* 979 * Since we are not going to create any new dirty data and we can even 980 * help with clearing the existing dirty data, we should not be subject 981 * to the dirty data based delays. 982 * We (ab)use TXG_WAITED to bypass the delay mechanism. 983 * One side effect from using TXG_WAITED is that dmu_tx_assign() can 984 * fail if the pool is suspended. Those are dramatic circumstances, 985 * so we return NULL to signal that the normal ZIL processing is not 986 * possible and txg_wait_synced() should be used to ensure that the data 987 * is on disk. 988 */ 989 error = dmu_tx_assign(tx, TXG_WAITED); 990 if (error != 0) { 991 ASSERT3S(error, ==, EIO); 992 dmu_tx_abort(tx); 993 return (NULL); 994 } 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 zio_nowait(lwb->lwb_zio); /* Kick off the write for the old log block */ 1064 1065 /* 1066 * If there was an allocation failure then nlwb will be null which 1067 * forces a txg_wait_synced(). 1068 */ 1069 return (nlwb); 1070 } 1071 1072 static lwb_t * 1073 zil_lwb_commit(zilog_t *zilog, itx_t *itx, lwb_t *lwb) 1074 { 1075 lr_t *lrcb, *lrc; 1076 lr_write_t *lrwb, *lrw; 1077 char *lr_buf; 1078 uint64_t dlen, dnow, lwb_sp, reclen, txg; 1079 1080 if (lwb == NULL) 1081 return (NULL); 1082 1083 ASSERT(lwb->lwb_buf != NULL); 1084 1085 lrc = &itx->itx_lr; /* Common log record inside itx. */ 1086 lrw = (lr_write_t *)lrc; /* Write log record inside itx. */ 1087 if (lrc->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY) { 1088 dlen = P2ROUNDUP_TYPED( 1089 lrw->lr_length, sizeof (uint64_t), uint64_t); 1090 } else { 1091 dlen = 0; 1092 } 1093 reclen = lrc->lrc_reclen; 1094 zilog->zl_cur_used += (reclen + dlen); 1095 txg = lrc->lrc_txg; 1096 1097 zil_lwb_write_init(zilog, lwb); 1098 1099 cont: 1100 /* 1101 * If this record won't fit in the current log block, start a new one. 1102 * For WR_NEED_COPY optimize layout for minimal number of chunks. 1103 */ 1104 lwb_sp = lwb->lwb_sz - lwb->lwb_nused; 1105 if (reclen > lwb_sp || (reclen + dlen > lwb_sp && 1106 lwb_sp < ZIL_MAX_WASTE_SPACE && (dlen % ZIL_MAX_LOG_DATA == 0 || 1107 lwb_sp < reclen + dlen % ZIL_MAX_LOG_DATA))) { 1108 lwb = zil_lwb_write_start(zilog, lwb); 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; /* Like lrc, but inside lwb. */ 1121 lrwb = (lr_write_t *)lrcb; /* Like lrw, but inside lwb. */ 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 1179 itx_t * 1180 zil_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 1195 void 1196 zil_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 */ 1205 static void 1206 zil_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 1238 static int 1239 zil_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 */ 1255 static void 1256 zil_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 1299 void 1300 zil_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 zfs_dbgmsg("zil_itx_assign: missed itx cleanup for " 1338 "txg %llu", itxg->itxg_txg); 1339 clean = itxg->itxg_itxs; 1340 } 1341 itxg->itxg_txg = txg; 1342 itxs = itxg->itxg_itxs = kmem_zalloc(sizeof (itxs_t), KM_SLEEP); 1343 1344 list_create(&itxs->i_sync_list, sizeof (itx_t), 1345 offsetof(itx_t, itx_node)); 1346 avl_create(&itxs->i_async_tree, zil_aitx_compare, 1347 sizeof (itx_async_node_t), 1348 offsetof(itx_async_node_t, ia_node)); 1349 } 1350 if (itx->itx_sync) { 1351 list_insert_tail(&itxs->i_sync_list, itx); 1352 } else { 1353 avl_tree_t *t = &itxs->i_async_tree; 1354 uint64_t foid = ((lr_ooo_t *)&itx->itx_lr)->lr_foid; 1355 itx_async_node_t *ian; 1356 avl_index_t where; 1357 1358 ian = avl_find(t, &foid, &where); 1359 if (ian == NULL) { 1360 ian = kmem_alloc(sizeof (itx_async_node_t), KM_SLEEP); 1361 list_create(&ian->ia_list, sizeof (itx_t), 1362 offsetof(itx_t, itx_node)); 1363 ian->ia_foid = foid; 1364 avl_insert(t, ian, where); 1365 } 1366 list_insert_tail(&ian->ia_list, itx); 1367 } 1368 1369 itx->itx_lr.lrc_txg = dmu_tx_get_txg(tx); 1370 zilog_dirty(zilog, txg); 1371 mutex_exit(&itxg->itxg_lock); 1372 1373 /* Release the old itxs now we've dropped the lock */ 1374 if (clean != NULL) 1375 zil_itxg_clean(clean); 1376 } 1377 1378 /* 1379 * If there are any in-memory intent log transactions which have now been 1380 * synced then start up a taskq to free them. We should only do this after we 1381 * have written out the uberblocks (i.e. txg has been comitted) so that 1382 * don't inadvertently clean out in-memory log records that would be required 1383 * by zil_commit(). 1384 */ 1385 void 1386 zil_clean(zilog_t *zilog, uint64_t synced_txg) 1387 { 1388 itxg_t *itxg = &zilog->zl_itxg[synced_txg & TXG_MASK]; 1389 itxs_t *clean_me; 1390 1391 mutex_enter(&itxg->itxg_lock); 1392 if (itxg->itxg_itxs == NULL || itxg->itxg_txg == ZILTEST_TXG) { 1393 mutex_exit(&itxg->itxg_lock); 1394 return; 1395 } 1396 ASSERT3U(itxg->itxg_txg, <=, synced_txg); 1397 ASSERT(itxg->itxg_txg != 0); 1398 ASSERT(zilog->zl_clean_taskq != NULL); 1399 clean_me = itxg->itxg_itxs; 1400 itxg->itxg_itxs = NULL; 1401 itxg->itxg_txg = 0; 1402 mutex_exit(&itxg->itxg_lock); 1403 /* 1404 * Preferably start a task queue to free up the old itxs but 1405 * if taskq_dispatch can't allocate resources to do that then 1406 * free it in-line. This should be rare. Note, using TQ_SLEEP 1407 * created a bad performance problem. 1408 */ 1409 if (taskq_dispatch(zilog->zl_clean_taskq, 1410 (void (*)(void *))zil_itxg_clean, clean_me, TQ_NOSLEEP) == NULL) 1411 zil_itxg_clean(clean_me); 1412 } 1413 1414 /* 1415 * Get the list of itxs to commit into zl_itx_commit_list. 1416 */ 1417 static void 1418 zil_get_commit_list(zilog_t *zilog) 1419 { 1420 uint64_t otxg, txg; 1421 list_t *commit_list = &zilog->zl_itx_commit_list; 1422 1423 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1424 otxg = ZILTEST_TXG; 1425 else 1426 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1427 1428 /* 1429 * This is inherently racy, since there is nothing to prevent 1430 * the last synced txg from changing. That's okay since we'll 1431 * only commit things in the future. 1432 */ 1433 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1434 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1435 1436 mutex_enter(&itxg->itxg_lock); 1437 if (itxg->itxg_txg != txg) { 1438 mutex_exit(&itxg->itxg_lock); 1439 continue; 1440 } 1441 1442 /* 1443 * If we're adding itx records to the zl_itx_commit_list, 1444 * then the zil better be dirty in this "txg". We can assert 1445 * that here since we're holding the itxg_lock which will 1446 * prevent spa_sync from cleaning it. Once we add the itxs 1447 * to the zl_itx_commit_list we must commit it to disk even 1448 * if it's unnecessary (i.e. the txg was synced). 1449 */ 1450 ASSERT(zilog_is_dirty_in_txg(zilog, txg) || 1451 spa_freeze_txg(zilog->zl_spa) != UINT64_MAX); 1452 list_move_tail(commit_list, &itxg->itxg_itxs->i_sync_list); 1453 1454 mutex_exit(&itxg->itxg_lock); 1455 } 1456 } 1457 1458 /* 1459 * Move the async itxs for a specified object to commit into sync lists. 1460 */ 1461 static void 1462 zil_async_to_sync(zilog_t *zilog, uint64_t foid) 1463 { 1464 uint64_t otxg, txg; 1465 itx_async_node_t *ian; 1466 avl_tree_t *t; 1467 avl_index_t where; 1468 1469 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1470 otxg = ZILTEST_TXG; 1471 else 1472 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1473 1474 /* 1475 * This is inherently racy, since there is nothing to prevent 1476 * the last synced txg from changing. 1477 */ 1478 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1479 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1480 1481 mutex_enter(&itxg->itxg_lock); 1482 if (itxg->itxg_txg != txg) { 1483 mutex_exit(&itxg->itxg_lock); 1484 continue; 1485 } 1486 1487 /* 1488 * If a foid is specified then find that node and append its 1489 * list. Otherwise walk the tree appending all the lists 1490 * to the sync list. We add to the end rather than the 1491 * beginning to ensure the create has happened. 1492 */ 1493 t = &itxg->itxg_itxs->i_async_tree; 1494 if (foid != 0) { 1495 ian = avl_find(t, &foid, &where); 1496 if (ian != NULL) { 1497 list_move_tail(&itxg->itxg_itxs->i_sync_list, 1498 &ian->ia_list); 1499 } 1500 } else { 1501 void *cookie = NULL; 1502 1503 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) { 1504 list_move_tail(&itxg->itxg_itxs->i_sync_list, 1505 &ian->ia_list); 1506 list_destroy(&ian->ia_list); 1507 kmem_free(ian, sizeof (itx_async_node_t)); 1508 } 1509 } 1510 mutex_exit(&itxg->itxg_lock); 1511 } 1512 } 1513 1514 static void 1515 zil_commit_writer(zilog_t *zilog) 1516 { 1517 uint64_t txg; 1518 itx_t *itx; 1519 lwb_t *lwb; 1520 spa_t *spa = zilog->zl_spa; 1521 int error = 0; 1522 1523 ASSERT(zilog->zl_root_zio == NULL); 1524 1525 mutex_exit(&zilog->zl_lock); 1526 1527 zil_get_commit_list(zilog); 1528 1529 /* 1530 * Return if there's nothing to commit before we dirty the fs by 1531 * calling zil_create(). 1532 */ 1533 if (list_head(&zilog->zl_itx_commit_list) == NULL) { 1534 mutex_enter(&zilog->zl_lock); 1535 return; 1536 } 1537 1538 if (zilog->zl_suspend) { 1539 lwb = NULL; 1540 } else { 1541 lwb = list_tail(&zilog->zl_lwb_list); 1542 if (lwb == NULL) 1543 lwb = zil_create(zilog); 1544 } 1545 1546 DTRACE_PROBE1(zil__cw1, zilog_t *, zilog); 1547 while (itx = list_head(&zilog->zl_itx_commit_list)) { 1548 txg = itx->itx_lr.lrc_txg; 1549 ASSERT3U(txg, !=, 0); 1550 1551 /* 1552 * This is inherently racy and may result in us writing 1553 * out a log block for a txg that was just synced. This is 1554 * ok since we'll end cleaning up that log block the next 1555 * time we call zil_sync(). 1556 */ 1557 if (txg > spa_last_synced_txg(spa) || txg > spa_freeze_txg(spa)) 1558 lwb = zil_lwb_commit(zilog, itx, lwb); 1559 list_remove(&zilog->zl_itx_commit_list, itx); 1560 kmem_free(itx, offsetof(itx_t, itx_lr) 1561 + itx->itx_lr.lrc_reclen); 1562 } 1563 DTRACE_PROBE1(zil__cw2, zilog_t *, zilog); 1564 1565 /* write the last block out */ 1566 if (lwb != NULL && lwb->lwb_zio != NULL) 1567 lwb = zil_lwb_write_start(zilog, lwb); 1568 1569 zilog->zl_cur_used = 0; 1570 1571 /* 1572 * Wait if necessary for the log blocks to be on stable storage. 1573 */ 1574 if (zilog->zl_root_zio) { 1575 error = zio_wait(zilog->zl_root_zio); 1576 zilog->zl_root_zio = NULL; 1577 zil_flush_vdevs(zilog); 1578 } 1579 1580 if (error || lwb == NULL) 1581 txg_wait_synced(zilog->zl_dmu_pool, 0); 1582 1583 mutex_enter(&zilog->zl_lock); 1584 1585 /* 1586 * Remember the highest committed log sequence number for ztest. 1587 * We only update this value when all the log writes succeeded, 1588 * because ztest wants to ASSERT that it got the whole log chain. 1589 */ 1590 if (error == 0 && lwb != NULL) 1591 zilog->zl_commit_lr_seq = zilog->zl_lr_seq; 1592 } 1593 1594 /* 1595 * Commit zfs transactions to stable storage. 1596 * If foid is 0 push out all transactions, otherwise push only those 1597 * for that object or might reference that object. 1598 * 1599 * itxs are committed in batches. In a heavily stressed zil there will be 1600 * a commit writer thread who is writing out a bunch of itxs to the log 1601 * for a set of committing threads (cthreads) in the same batch as the writer. 1602 * Those cthreads are all waiting on the same cv for that batch. 1603 * 1604 * There will also be a different and growing batch of threads that are 1605 * waiting to commit (qthreads). When the committing batch completes 1606 * a transition occurs such that the cthreads exit and the qthreads become 1607 * cthreads. One of the new cthreads becomes the writer thread for the 1608 * batch. Any new threads arriving become new qthreads. 1609 * 1610 * Only 2 condition variables are needed and there's no transition 1611 * between the two cvs needed. They just flip-flop between qthreads 1612 * and cthreads. 1613 * 1614 * Using this scheme we can efficiently wakeup up only those threads 1615 * that have been committed. 1616 */ 1617 void 1618 zil_commit(zilog_t *zilog, uint64_t foid) 1619 { 1620 uint64_t mybatch; 1621 1622 if (zilog->zl_sync == ZFS_SYNC_DISABLED) 1623 return; 1624 1625 /* move the async itxs for the foid to the sync queues */ 1626 zil_async_to_sync(zilog, foid); 1627 1628 mutex_enter(&zilog->zl_lock); 1629 mybatch = zilog->zl_next_batch; 1630 while (zilog->zl_writer) { 1631 cv_wait(&zilog->zl_cv_batch[mybatch & 1], &zilog->zl_lock); 1632 if (mybatch <= zilog->zl_com_batch) { 1633 mutex_exit(&zilog->zl_lock); 1634 return; 1635 } 1636 } 1637 1638 zilog->zl_next_batch++; 1639 zilog->zl_writer = B_TRUE; 1640 zil_commit_writer(zilog); 1641 zilog->zl_com_batch = mybatch; 1642 zilog->zl_writer = B_FALSE; 1643 mutex_exit(&zilog->zl_lock); 1644 1645 /* wake up one thread to become the next writer */ 1646 cv_signal(&zilog->zl_cv_batch[(mybatch+1) & 1]); 1647 1648 /* wake up all threads waiting for this batch to be committed */ 1649 cv_broadcast(&zilog->zl_cv_batch[mybatch & 1]); 1650 } 1651 1652 /* 1653 * Called in syncing context to free committed log blocks and update log header. 1654 */ 1655 void 1656 zil_sync(zilog_t *zilog, dmu_tx_t *tx) 1657 { 1658 zil_header_t *zh = zil_header_in_syncing_context(zilog); 1659 uint64_t txg = dmu_tx_get_txg(tx); 1660 spa_t *spa = zilog->zl_spa; 1661 uint64_t *replayed_seq = &zilog->zl_replayed_seq[txg & TXG_MASK]; 1662 lwb_t *lwb; 1663 1664 /* 1665 * We don't zero out zl_destroy_txg, so make sure we don't try 1666 * to destroy it twice. 1667 */ 1668 if (spa_sync_pass(spa) != 1) 1669 return; 1670 1671 mutex_enter(&zilog->zl_lock); 1672 1673 ASSERT(zilog->zl_stop_sync == 0); 1674 1675 if (*replayed_seq != 0) { 1676 ASSERT(zh->zh_replay_seq < *replayed_seq); 1677 zh->zh_replay_seq = *replayed_seq; 1678 *replayed_seq = 0; 1679 } 1680 1681 if (zilog->zl_destroy_txg == txg) { 1682 blkptr_t blk = zh->zh_log; 1683 1684 ASSERT(list_head(&zilog->zl_lwb_list) == NULL); 1685 1686 bzero(zh, sizeof (zil_header_t)); 1687 bzero(zilog->zl_replayed_seq, sizeof (zilog->zl_replayed_seq)); 1688 1689 if (zilog->zl_keep_first) { 1690 /* 1691 * If this block was part of log chain that couldn't 1692 * be claimed because a device was missing during 1693 * zil_claim(), but that device later returns, 1694 * then this block could erroneously appear valid. 1695 * To guard against this, assign a new GUID to the new 1696 * log chain so it doesn't matter what blk points to. 1697 */ 1698 zil_init_log_chain(zilog, &blk); 1699 zh->zh_log = blk; 1700 } 1701 } 1702 1703 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { 1704 zh->zh_log = lwb->lwb_blk; 1705 if (lwb->lwb_buf != NULL || lwb->lwb_max_txg > txg) 1706 break; 1707 list_remove(&zilog->zl_lwb_list, lwb); 1708 zio_free_zil(spa, txg, &lwb->lwb_blk); 1709 kmem_cache_free(zil_lwb_cache, lwb); 1710 1711 /* 1712 * If we don't have anything left in the lwb list then 1713 * we've had an allocation failure and we need to zero 1714 * out the zil_header blkptr so that we don't end 1715 * up freeing the same block twice. 1716 */ 1717 if (list_head(&zilog->zl_lwb_list) == NULL) 1718 BP_ZERO(&zh->zh_log); 1719 } 1720 mutex_exit(&zilog->zl_lock); 1721 } 1722 1723 void 1724 zil_init(void) 1725 { 1726 zil_lwb_cache = kmem_cache_create("zil_lwb_cache", 1727 sizeof (struct lwb), 0, NULL, NULL, NULL, NULL, NULL, 0); 1728 } 1729 1730 void 1731 zil_fini(void) 1732 { 1733 kmem_cache_destroy(zil_lwb_cache); 1734 } 1735 1736 void 1737 zil_set_sync(zilog_t *zilog, uint64_t sync) 1738 { 1739 zilog->zl_sync = sync; 1740 } 1741 1742 void 1743 zil_set_logbias(zilog_t *zilog, uint64_t logbias) 1744 { 1745 zilog->zl_logbias = logbias; 1746 } 1747 1748 zilog_t * 1749 zil_alloc(objset_t *os, zil_header_t *zh_phys) 1750 { 1751 zilog_t *zilog; 1752 1753 zilog = kmem_zalloc(sizeof (zilog_t), KM_SLEEP); 1754 1755 zilog->zl_header = zh_phys; 1756 zilog->zl_os = os; 1757 zilog->zl_spa = dmu_objset_spa(os); 1758 zilog->zl_dmu_pool = dmu_objset_pool(os); 1759 zilog->zl_destroy_txg = TXG_INITIAL - 1; 1760 zilog->zl_logbias = dmu_objset_logbias(os); 1761 zilog->zl_sync = dmu_objset_syncprop(os); 1762 zilog->zl_next_batch = 1; 1763 1764 mutex_init(&zilog->zl_lock, NULL, MUTEX_DEFAULT, NULL); 1765 1766 for (int i = 0; i < TXG_SIZE; i++) { 1767 mutex_init(&zilog->zl_itxg[i].itxg_lock, NULL, 1768 MUTEX_DEFAULT, NULL); 1769 } 1770 1771 list_create(&zilog->zl_lwb_list, sizeof (lwb_t), 1772 offsetof(lwb_t, lwb_node)); 1773 1774 list_create(&zilog->zl_itx_commit_list, sizeof (itx_t), 1775 offsetof(itx_t, itx_node)); 1776 1777 mutex_init(&zilog->zl_vdev_lock, NULL, MUTEX_DEFAULT, NULL); 1778 1779 avl_create(&zilog->zl_vdev_tree, zil_vdev_compare, 1780 sizeof (zil_vdev_node_t), offsetof(zil_vdev_node_t, zv_node)); 1781 1782 cv_init(&zilog->zl_cv_writer, NULL, CV_DEFAULT, NULL); 1783 cv_init(&zilog->zl_cv_suspend, NULL, CV_DEFAULT, NULL); 1784 cv_init(&zilog->zl_cv_batch[0], NULL, CV_DEFAULT, NULL); 1785 cv_init(&zilog->zl_cv_batch[1], NULL, CV_DEFAULT, NULL); 1786 1787 return (zilog); 1788 } 1789 1790 void 1791 zil_free(zilog_t *zilog) 1792 { 1793 zilog->zl_stop_sync = 1; 1794 1795 ASSERT0(zilog->zl_suspend); 1796 ASSERT0(zilog->zl_suspending); 1797 1798 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 1799 list_destroy(&zilog->zl_lwb_list); 1800 1801 avl_destroy(&zilog->zl_vdev_tree); 1802 mutex_destroy(&zilog->zl_vdev_lock); 1803 1804 ASSERT(list_is_empty(&zilog->zl_itx_commit_list)); 1805 list_destroy(&zilog->zl_itx_commit_list); 1806 1807 for (int i = 0; i < TXG_SIZE; i++) { 1808 /* 1809 * It's possible for an itx to be generated that doesn't dirty 1810 * a txg (e.g. ztest TX_TRUNCATE). So there's no zil_clean() 1811 * callback to remove the entry. We remove those here. 1812 * 1813 * Also free up the ziltest itxs. 1814 */ 1815 if (zilog->zl_itxg[i].itxg_itxs) 1816 zil_itxg_clean(zilog->zl_itxg[i].itxg_itxs); 1817 mutex_destroy(&zilog->zl_itxg[i].itxg_lock); 1818 } 1819 1820 mutex_destroy(&zilog->zl_lock); 1821 1822 cv_destroy(&zilog->zl_cv_writer); 1823 cv_destroy(&zilog->zl_cv_suspend); 1824 cv_destroy(&zilog->zl_cv_batch[0]); 1825 cv_destroy(&zilog->zl_cv_batch[1]); 1826 1827 kmem_free(zilog, sizeof (zilog_t)); 1828 } 1829 1830 /* 1831 * Open an intent log. 1832 */ 1833 zilog_t * 1834 zil_open(objset_t *os, zil_get_data_t *get_data) 1835 { 1836 zilog_t *zilog = dmu_objset_zil(os); 1837 1838 ASSERT(zilog->zl_clean_taskq == NULL); 1839 ASSERT(zilog->zl_get_data == NULL); 1840 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 1841 1842 zilog->zl_get_data = get_data; 1843 zilog->zl_clean_taskq = taskq_create("zil_clean", 1, minclsyspri, 1844 2, 2, TASKQ_PREPOPULATE); 1845 1846 return (zilog); 1847 } 1848 1849 /* 1850 * Close an intent log. 1851 */ 1852 void 1853 zil_close(zilog_t *zilog) 1854 { 1855 lwb_t *lwb; 1856 uint64_t txg = 0; 1857 1858 zil_commit(zilog, 0); /* commit all itx */ 1859 1860 /* 1861 * The lwb_max_txg for the stubby lwb will reflect the last activity 1862 * for the zil. After a txg_wait_synced() on the txg we know all the 1863 * callbacks have occurred that may clean the zil. Only then can we 1864 * destroy the zl_clean_taskq. 1865 */ 1866 mutex_enter(&zilog->zl_lock); 1867 lwb = list_tail(&zilog->zl_lwb_list); 1868 if (lwb != NULL) 1869 txg = lwb->lwb_max_txg; 1870 mutex_exit(&zilog->zl_lock); 1871 if (txg) 1872 txg_wait_synced(zilog->zl_dmu_pool, txg); 1873 1874 if (zilog_is_dirty(zilog)) 1875 zfs_dbgmsg("zil (%p) is dirty, txg %llu", zilog, txg); 1876 VERIFY(!zilog_is_dirty(zilog)); 1877 1878 taskq_destroy(zilog->zl_clean_taskq); 1879 zilog->zl_clean_taskq = NULL; 1880 zilog->zl_get_data = NULL; 1881 1882 /* 1883 * We should have only one LWB left on the list; remove it now. 1884 */ 1885 mutex_enter(&zilog->zl_lock); 1886 lwb = list_head(&zilog->zl_lwb_list); 1887 if (lwb != NULL) { 1888 ASSERT(lwb == list_tail(&zilog->zl_lwb_list)); 1889 list_remove(&zilog->zl_lwb_list, lwb); 1890 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 1891 kmem_cache_free(zil_lwb_cache, lwb); 1892 } 1893 mutex_exit(&zilog->zl_lock); 1894 } 1895 1896 static char *suspend_tag = "zil suspending"; 1897 1898 /* 1899 * Suspend an intent log. While in suspended mode, we still honor 1900 * synchronous semantics, but we rely on txg_wait_synced() to do it. 1901 * On old version pools, we suspend the log briefly when taking a 1902 * snapshot so that it will have an empty intent log. 1903 * 1904 * Long holds are not really intended to be used the way we do here -- 1905 * held for such a short time. A concurrent caller of dsl_dataset_long_held() 1906 * could fail. Therefore we take pains to only put a long hold if it is 1907 * actually necessary. Fortunately, it will only be necessary if the 1908 * objset is currently mounted (or the ZVOL equivalent). In that case it 1909 * will already have a long hold, so we are not really making things any worse. 1910 * 1911 * Ideally, we would locate the existing long-holder (i.e. the zfsvfs_t or 1912 * zvol_state_t), and use their mechanism to prevent their hold from being 1913 * dropped (e.g. VFS_HOLD()). However, that would be even more pain for 1914 * very little gain. 1915 * 1916 * if cookiep == NULL, this does both the suspend & resume. 1917 * Otherwise, it returns with the dataset "long held", and the cookie 1918 * should be passed into zil_resume(). 1919 */ 1920 int 1921 zil_suspend(const char *osname, void **cookiep) 1922 { 1923 objset_t *os; 1924 zilog_t *zilog; 1925 const zil_header_t *zh; 1926 int error; 1927 1928 error = dmu_objset_hold(osname, suspend_tag, &os); 1929 if (error != 0) 1930 return (error); 1931 zilog = dmu_objset_zil(os); 1932 1933 mutex_enter(&zilog->zl_lock); 1934 zh = zilog->zl_header; 1935 1936 if (zh->zh_flags & ZIL_REPLAY_NEEDED) { /* unplayed log */ 1937 mutex_exit(&zilog->zl_lock); 1938 dmu_objset_rele(os, suspend_tag); 1939 return (SET_ERROR(EBUSY)); 1940 } 1941 1942 /* 1943 * Don't put a long hold in the cases where we can avoid it. This 1944 * is when there is no cookie so we are doing a suspend & resume 1945 * (i.e. called from zil_vdev_offline()), and there's nothing to do 1946 * for the suspend because it's already suspended, or there's no ZIL. 1947 */ 1948 if (cookiep == NULL && !zilog->zl_suspending && 1949 (zilog->zl_suspend > 0 || BP_IS_HOLE(&zh->zh_log))) { 1950 mutex_exit(&zilog->zl_lock); 1951 dmu_objset_rele(os, suspend_tag); 1952 return (0); 1953 } 1954 1955 dsl_dataset_long_hold(dmu_objset_ds(os), suspend_tag); 1956 dsl_pool_rele(dmu_objset_pool(os), suspend_tag); 1957 1958 zilog->zl_suspend++; 1959 1960 if (zilog->zl_suspend > 1) { 1961 /* 1962 * Someone else is already suspending it. 1963 * Just wait for them to finish. 1964 */ 1965 1966 while (zilog->zl_suspending) 1967 cv_wait(&zilog->zl_cv_suspend, &zilog->zl_lock); 1968 mutex_exit(&zilog->zl_lock); 1969 1970 if (cookiep == NULL) 1971 zil_resume(os); 1972 else 1973 *cookiep = os; 1974 return (0); 1975 } 1976 1977 /* 1978 * If there is no pointer to an on-disk block, this ZIL must not 1979 * be active (e.g. filesystem not mounted), so there's nothing 1980 * to clean up. 1981 */ 1982 if (BP_IS_HOLE(&zh->zh_log)) { 1983 ASSERT(cookiep != NULL); /* fast path already handled */ 1984 1985 *cookiep = os; 1986 mutex_exit(&zilog->zl_lock); 1987 return (0); 1988 } 1989 1990 zilog->zl_suspending = B_TRUE; 1991 mutex_exit(&zilog->zl_lock); 1992 1993 zil_commit(zilog, 0); 1994 1995 zil_destroy(zilog, B_FALSE); 1996 1997 mutex_enter(&zilog->zl_lock); 1998 zilog->zl_suspending = B_FALSE; 1999 cv_broadcast(&zilog->zl_cv_suspend); 2000 mutex_exit(&zilog->zl_lock); 2001 2002 if (cookiep == NULL) 2003 zil_resume(os); 2004 else 2005 *cookiep = os; 2006 return (0); 2007 } 2008 2009 void 2010 zil_resume(void *cookie) 2011 { 2012 objset_t *os = cookie; 2013 zilog_t *zilog = dmu_objset_zil(os); 2014 2015 mutex_enter(&zilog->zl_lock); 2016 ASSERT(zilog->zl_suspend != 0); 2017 zilog->zl_suspend--; 2018 mutex_exit(&zilog->zl_lock); 2019 dsl_dataset_long_rele(dmu_objset_ds(os), suspend_tag); 2020 dsl_dataset_rele(dmu_objset_ds(os), suspend_tag); 2021 } 2022 2023 typedef struct zil_replay_arg { 2024 zil_replay_func_t **zr_replay; 2025 void *zr_arg; 2026 boolean_t zr_byteswap; 2027 char *zr_lr; 2028 } zil_replay_arg_t; 2029 2030 static int 2031 zil_replay_error(zilog_t *zilog, lr_t *lr, int error) 2032 { 2033 char name[ZFS_MAX_DATASET_NAME_LEN]; 2034 2035 zilog->zl_replaying_seq--; /* didn't actually replay this one */ 2036 2037 dmu_objset_name(zilog->zl_os, name); 2038 2039 cmn_err(CE_WARN, "ZFS replay transaction error %d, " 2040 "dataset %s, seq 0x%llx, txtype %llu %s\n", error, name, 2041 (u_longlong_t)lr->lrc_seq, 2042 (u_longlong_t)(lr->lrc_txtype & ~TX_CI), 2043 (lr->lrc_txtype & TX_CI) ? "CI" : ""); 2044 2045 return (error); 2046 } 2047 2048 static int 2049 zil_replay_log_record(zilog_t *zilog, lr_t *lr, void *zra, uint64_t claim_txg) 2050 { 2051 zil_replay_arg_t *zr = zra; 2052 const zil_header_t *zh = zilog->zl_header; 2053 uint64_t reclen = lr->lrc_reclen; 2054 uint64_t txtype = lr->lrc_txtype; 2055 int error = 0; 2056 2057 zilog->zl_replaying_seq = lr->lrc_seq; 2058 2059 if (lr->lrc_seq <= zh->zh_replay_seq) /* already replayed */ 2060 return (0); 2061 2062 if (lr->lrc_txg < claim_txg) /* already committed */ 2063 return (0); 2064 2065 /* Strip case-insensitive bit, still present in log record */ 2066 txtype &= ~TX_CI; 2067 2068 if (txtype == 0 || txtype >= TX_MAX_TYPE) 2069 return (zil_replay_error(zilog, lr, EINVAL)); 2070 2071 /* 2072 * If this record type can be logged out of order, the object 2073 * (lr_foid) may no longer exist. That's legitimate, not an error. 2074 */ 2075 if (TX_OOO(txtype)) { 2076 error = dmu_object_info(zilog->zl_os, 2077 ((lr_ooo_t *)lr)->lr_foid, NULL); 2078 if (error == ENOENT || error == EEXIST) 2079 return (0); 2080 } 2081 2082 /* 2083 * Make a copy of the data so we can revise and extend it. 2084 */ 2085 bcopy(lr, zr->zr_lr, reclen); 2086 2087 /* 2088 * If this is a TX_WRITE with a blkptr, suck in the data. 2089 */ 2090 if (txtype == TX_WRITE && reclen == sizeof (lr_write_t)) { 2091 error = zil_read_log_data(zilog, (lr_write_t *)lr, 2092 zr->zr_lr + reclen); 2093 if (error != 0) 2094 return (zil_replay_error(zilog, lr, error)); 2095 } 2096 2097 /* 2098 * The log block containing this lr may have been byteswapped 2099 * so that we can easily examine common fields like lrc_txtype. 2100 * However, the log is a mix of different record types, and only the 2101 * replay vectors know how to byteswap their records. Therefore, if 2102 * the lr was byteswapped, undo it before invoking the replay vector. 2103 */ 2104 if (zr->zr_byteswap) 2105 byteswap_uint64_array(zr->zr_lr, reclen); 2106 2107 /* 2108 * We must now do two things atomically: replay this log record, 2109 * and update the log header sequence number to reflect the fact that 2110 * we did so. At the end of each replay function the sequence number 2111 * is updated if we are in replay mode. 2112 */ 2113 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, zr->zr_byteswap); 2114 if (error != 0) { 2115 /* 2116 * The DMU's dnode layer doesn't see removes until the txg 2117 * commits, so a subsequent claim can spuriously fail with 2118 * EEXIST. So if we receive any error we try syncing out 2119 * any removes then retry the transaction. Note that we 2120 * specify B_FALSE for byteswap now, so we don't do it twice. 2121 */ 2122 txg_wait_synced(spa_get_dsl(zilog->zl_spa), 0); 2123 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, B_FALSE); 2124 if (error != 0) 2125 return (zil_replay_error(zilog, lr, error)); 2126 } 2127 return (0); 2128 } 2129 2130 /* ARGSUSED */ 2131 static int 2132 zil_incr_blks(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg) 2133 { 2134 zilog->zl_replay_blks++; 2135 2136 return (0); 2137 } 2138 2139 /* 2140 * If this dataset has a non-empty intent log, replay it and destroy it. 2141 */ 2142 void 2143 zil_replay(objset_t *os, void *arg, zil_replay_func_t *replay_func[TX_MAX_TYPE]) 2144 { 2145 zilog_t *zilog = dmu_objset_zil(os); 2146 const zil_header_t *zh = zilog->zl_header; 2147 zil_replay_arg_t zr; 2148 2149 if ((zh->zh_flags & ZIL_REPLAY_NEEDED) == 0) { 2150 zil_destroy(zilog, B_TRUE); 2151 return; 2152 } 2153 2154 zr.zr_replay = replay_func; 2155 zr.zr_arg = arg; 2156 zr.zr_byteswap = BP_SHOULD_BYTESWAP(&zh->zh_log); 2157 zr.zr_lr = kmem_alloc(2 * SPA_MAXBLOCKSIZE, KM_SLEEP); 2158 2159 /* 2160 * Wait for in-progress removes to sync before starting replay. 2161 */ 2162 txg_wait_synced(zilog->zl_dmu_pool, 0); 2163 2164 zilog->zl_replay = B_TRUE; 2165 zilog->zl_replay_time = ddi_get_lbolt(); 2166 ASSERT(zilog->zl_replay_blks == 0); 2167 (void) zil_parse(zilog, zil_incr_blks, zil_replay_log_record, &zr, 2168 zh->zh_claim_txg); 2169 kmem_free(zr.zr_lr, 2 * SPA_MAXBLOCKSIZE); 2170 2171 zil_destroy(zilog, B_FALSE); 2172 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 2173 zilog->zl_replay = B_FALSE; 2174 } 2175 2176 boolean_t 2177 zil_replaying(zilog_t *zilog, dmu_tx_t *tx) 2178 { 2179 if (zilog->zl_sync == ZFS_SYNC_DISABLED) 2180 return (B_TRUE); 2181 2182 if (zilog->zl_replay) { 2183 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 2184 zilog->zl_replayed_seq[dmu_tx_get_txg(tx) & TXG_MASK] = 2185 zilog->zl_replaying_seq; 2186 return (B_TRUE); 2187 } 2188 2189 return (B_FALSE); 2190 } 2191 2192 /* ARGSUSED */ 2193 int 2194 zil_vdev_offline(const char *osname, void *arg) 2195 { 2196 int error; 2197 2198 error = zil_suspend(osname, NULL); 2199 if (error != 0) 2200 return (SET_ERROR(EEXIST)); 2201 return (0); 2202 } 2203