1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2011, 2016 by Delphix. All rights reserved. 24 * Copyright (c) 2014 Integros [integros.com] 25 */ 26 27 /* Portions Copyright 2010 Robert Milkowski */ 28 29 #include <sys/zfs_context.h> 30 #include <sys/spa.h> 31 #include <sys/dmu.h> 32 #include <sys/zap.h> 33 #include <sys/arc.h> 34 #include <sys/stat.h> 35 #include <sys/resource.h> 36 #include <sys/zil.h> 37 #include <sys/zil_impl.h> 38 #include <sys/dsl_dataset.h> 39 #include <sys/vdev_impl.h> 40 #include <sys/dmu_tx.h> 41 #include <sys/dsl_pool.h> 42 43 /* 44 * The zfs intent log (ZIL) saves transaction records of system calls 45 * that change the file system in memory with enough information 46 * to be able to replay them. These are stored in memory until 47 * either the DMU transaction group (txg) commits them to the stable pool 48 * and they can be discarded, or they are flushed to the stable log 49 * (also in the pool) due to a fsync, O_DSYNC or other synchronous 50 * requirement. In the event of a panic or power fail then those log 51 * records (transactions) are replayed. 52 * 53 * There is one ZIL per file system. Its on-disk (pool) format consists 54 * of 3 parts: 55 * 56 * - ZIL header 57 * - ZIL blocks 58 * - ZIL records 59 * 60 * A log record holds a system call transaction. Log blocks can 61 * hold many log records and the blocks are chained together. 62 * Each ZIL block contains a block pointer (blkptr_t) to the next 63 * ZIL block in the chain. The ZIL header points to the first 64 * block in the chain. Note there is not a fixed place in the pool 65 * to hold blocks. They are dynamically allocated and freed as 66 * needed from the blocks available. Figure X shows the ZIL structure: 67 */ 68 69 /* 70 * Disable intent logging replay. This global ZIL switch affects all pools. 71 */ 72 int zil_replay_disable = 0; 73 74 /* 75 * Tunable parameter for debugging or performance analysis. Setting 76 * zfs_nocacheflush will cause corruption on power loss if a volatile 77 * out-of-order write cache is enabled. 78 */ 79 boolean_t zfs_nocacheflush = B_FALSE; 80 81 static kmem_cache_t *zil_lwb_cache; 82 83 static void zil_async_to_sync(zilog_t *zilog, uint64_t foid); 84 85 #define LWB_EMPTY(lwb) ((BP_GET_LSIZE(&lwb->lwb_blk) - \ 86 sizeof (zil_chain_t)) == (lwb->lwb_sz - lwb->lwb_nused)) 87 88 89 /* 90 * ziltest is by and large an ugly hack, but very useful in 91 * checking replay without tedious work. 92 * When running ziltest we want to keep all itx's and so maintain 93 * a single list in the zl_itxg[] that uses a high txg: ZILTEST_TXG 94 * We subtract TXG_CONCURRENT_STATES to allow for common code. 95 */ 96 #define ZILTEST_TXG (UINT64_MAX - TXG_CONCURRENT_STATES) 97 98 static int 99 zil_bp_compare(const void *x1, const void *x2) 100 { 101 const dva_t *dva1 = &((zil_bp_node_t *)x1)->zn_dva; 102 const dva_t *dva2 = &((zil_bp_node_t *)x2)->zn_dva; 103 104 if (DVA_GET_VDEV(dva1) < DVA_GET_VDEV(dva2)) 105 return (-1); 106 if (DVA_GET_VDEV(dva1) > DVA_GET_VDEV(dva2)) 107 return (1); 108 109 if (DVA_GET_OFFSET(dva1) < DVA_GET_OFFSET(dva2)) 110 return (-1); 111 if (DVA_GET_OFFSET(dva1) > DVA_GET_OFFSET(dva2)) 112 return (1); 113 114 return (0); 115 } 116 117 static void 118 zil_bp_tree_init(zilog_t *zilog) 119 { 120 avl_create(&zilog->zl_bp_tree, zil_bp_compare, 121 sizeof (zil_bp_node_t), offsetof(zil_bp_node_t, zn_node)); 122 } 123 124 static void 125 zil_bp_tree_fini(zilog_t *zilog) 126 { 127 avl_tree_t *t = &zilog->zl_bp_tree; 128 zil_bp_node_t *zn; 129 void *cookie = NULL; 130 131 while ((zn = avl_destroy_nodes(t, &cookie)) != NULL) 132 kmem_free(zn, sizeof (zil_bp_node_t)); 133 134 avl_destroy(t); 135 } 136 137 int 138 zil_bp_tree_add(zilog_t *zilog, const blkptr_t *bp) 139 { 140 avl_tree_t *t = &zilog->zl_bp_tree; 141 const dva_t *dva; 142 zil_bp_node_t *zn; 143 avl_index_t where; 144 145 if (BP_IS_EMBEDDED(bp)) 146 return (0); 147 148 dva = BP_IDENTITY(bp); 149 150 if (avl_find(t, dva, &where) != NULL) 151 return (SET_ERROR(EEXIST)); 152 153 zn = kmem_alloc(sizeof (zil_bp_node_t), KM_SLEEP); 154 zn->zn_dva = *dva; 155 avl_insert(t, zn, where); 156 157 return (0); 158 } 159 160 static zil_header_t * 161 zil_header_in_syncing_context(zilog_t *zilog) 162 { 163 return ((zil_header_t *)zilog->zl_header); 164 } 165 166 static void 167 zil_init_log_chain(zilog_t *zilog, blkptr_t *bp) 168 { 169 zio_cksum_t *zc = &bp->blk_cksum; 170 171 zc->zc_word[ZIL_ZC_GUID_0] = spa_get_random(-1ULL); 172 zc->zc_word[ZIL_ZC_GUID_1] = spa_get_random(-1ULL); 173 zc->zc_word[ZIL_ZC_OBJSET] = dmu_objset_id(zilog->zl_os); 174 zc->zc_word[ZIL_ZC_SEQ] = 1ULL; 175 } 176 177 /* 178 * Read a log block and make sure it's valid. 179 */ 180 static int 181 zil_read_log_block(zilog_t *zilog, const blkptr_t *bp, blkptr_t *nbp, void *dst, 182 char **end) 183 { 184 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL; 185 arc_flags_t aflags = ARC_FLAG_WAIT; 186 arc_buf_t *abuf = NULL; 187 zbookmark_phys_t zb; 188 int error; 189 190 if (zilog->zl_header->zh_claim_txg == 0) 191 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; 192 193 if (!(zilog->zl_header->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) 194 zio_flags |= ZIO_FLAG_SPECULATIVE; 195 196 SET_BOOKMARK(&zb, bp->blk_cksum.zc_word[ZIL_ZC_OBJSET], 197 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]); 198 199 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf, 200 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); 201 202 if (error == 0) { 203 zio_cksum_t cksum = bp->blk_cksum; 204 205 /* 206 * Validate the checksummed log block. 207 * 208 * Sequence numbers should be... sequential. The checksum 209 * verifier for the next block should be bp's checksum plus 1. 210 * 211 * Also check the log chain linkage and size used. 212 */ 213 cksum.zc_word[ZIL_ZC_SEQ]++; 214 215 if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) { 216 zil_chain_t *zilc = abuf->b_data; 217 char *lr = (char *)(zilc + 1); 218 uint64_t len = zilc->zc_nused - sizeof (zil_chain_t); 219 220 if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum, 221 sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk)) { 222 error = SET_ERROR(ECKSUM); 223 } else { 224 ASSERT3U(len, <=, SPA_OLD_MAXBLOCKSIZE); 225 bcopy(lr, dst, len); 226 *end = (char *)dst + len; 227 *nbp = zilc->zc_next_blk; 228 } 229 } else { 230 char *lr = abuf->b_data; 231 uint64_t size = BP_GET_LSIZE(bp); 232 zil_chain_t *zilc = (zil_chain_t *)(lr + size) - 1; 233 234 if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum, 235 sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk) || 236 (zilc->zc_nused > (size - sizeof (*zilc)))) { 237 error = SET_ERROR(ECKSUM); 238 } else { 239 ASSERT3U(zilc->zc_nused, <=, 240 SPA_OLD_MAXBLOCKSIZE); 241 bcopy(lr, dst, zilc->zc_nused); 242 *end = (char *)dst + zilc->zc_nused; 243 *nbp = zilc->zc_next_blk; 244 } 245 } 246 247 arc_buf_destroy(abuf, &abuf); 248 } 249 250 return (error); 251 } 252 253 /* 254 * Read a TX_WRITE log data block. 255 */ 256 static int 257 zil_read_log_data(zilog_t *zilog, const lr_write_t *lr, void *wbuf) 258 { 259 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL; 260 const blkptr_t *bp = &lr->lr_blkptr; 261 arc_flags_t aflags = ARC_FLAG_WAIT; 262 arc_buf_t *abuf = NULL; 263 zbookmark_phys_t zb; 264 int error; 265 266 if (BP_IS_HOLE(bp)) { 267 if (wbuf != NULL) 268 bzero(wbuf, MAX(BP_GET_LSIZE(bp), lr->lr_length)); 269 return (0); 270 } 271 272 if (zilog->zl_header->zh_claim_txg == 0) 273 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; 274 275 SET_BOOKMARK(&zb, dmu_objset_id(zilog->zl_os), lr->lr_foid, 276 ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp)); 277 278 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf, 279 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); 280 281 if (error == 0) { 282 if (wbuf != NULL) 283 bcopy(abuf->b_data, wbuf, arc_buf_size(abuf)); 284 arc_buf_destroy(abuf, &abuf); 285 } 286 287 return (error); 288 } 289 290 /* 291 * Parse the intent log, and call parse_func for each valid record within. 292 */ 293 int 294 zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func, 295 zil_parse_lr_func_t *parse_lr_func, void *arg, uint64_t txg) 296 { 297 const zil_header_t *zh = zilog->zl_header; 298 boolean_t claimed = !!zh->zh_claim_txg; 299 uint64_t claim_blk_seq = claimed ? zh->zh_claim_blk_seq : UINT64_MAX; 300 uint64_t claim_lr_seq = claimed ? zh->zh_claim_lr_seq : UINT64_MAX; 301 uint64_t max_blk_seq = 0; 302 uint64_t max_lr_seq = 0; 303 uint64_t blk_count = 0; 304 uint64_t lr_count = 0; 305 blkptr_t blk, next_blk; 306 char *lrbuf, *lrp; 307 int error = 0; 308 309 /* 310 * Old logs didn't record the maximum zh_claim_lr_seq. 311 */ 312 if (!(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) 313 claim_lr_seq = UINT64_MAX; 314 315 /* 316 * Starting at the block pointed to by zh_log we read the log chain. 317 * For each block in the chain we strongly check that block to 318 * ensure its validity. We stop when an invalid block is found. 319 * For each block pointer in the chain we call parse_blk_func(). 320 * For each record in each valid block we call parse_lr_func(). 321 * If the log has been claimed, stop if we encounter a sequence 322 * number greater than the highest claimed sequence number. 323 */ 324 lrbuf = zio_buf_alloc(SPA_OLD_MAXBLOCKSIZE); 325 zil_bp_tree_init(zilog); 326 327 for (blk = zh->zh_log; !BP_IS_HOLE(&blk); blk = next_blk) { 328 uint64_t blk_seq = blk.blk_cksum.zc_word[ZIL_ZC_SEQ]; 329 int reclen; 330 char *end; 331 332 if (blk_seq > claim_blk_seq) 333 break; 334 if ((error = parse_blk_func(zilog, &blk, arg, txg)) != 0) 335 break; 336 ASSERT3U(max_blk_seq, <, blk_seq); 337 max_blk_seq = blk_seq; 338 blk_count++; 339 340 if (max_lr_seq == claim_lr_seq && max_blk_seq == claim_blk_seq) 341 break; 342 343 error = zil_read_log_block(zilog, &blk, &next_blk, lrbuf, &end); 344 if (error != 0) 345 break; 346 347 for (lrp = lrbuf; lrp < end; lrp += reclen) { 348 lr_t *lr = (lr_t *)lrp; 349 reclen = lr->lrc_reclen; 350 ASSERT3U(reclen, >=, sizeof (lr_t)); 351 if (lr->lrc_seq > claim_lr_seq) 352 goto done; 353 if ((error = parse_lr_func(zilog, lr, arg, txg)) != 0) 354 goto done; 355 ASSERT3U(max_lr_seq, <, lr->lrc_seq); 356 max_lr_seq = lr->lrc_seq; 357 lr_count++; 358 } 359 } 360 done: 361 zilog->zl_parse_error = error; 362 zilog->zl_parse_blk_seq = max_blk_seq; 363 zilog->zl_parse_lr_seq = max_lr_seq; 364 zilog->zl_parse_blk_count = blk_count; 365 zilog->zl_parse_lr_count = lr_count; 366 367 ASSERT(!claimed || !(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID) || 368 (max_blk_seq == claim_blk_seq && max_lr_seq == claim_lr_seq)); 369 370 zil_bp_tree_fini(zilog); 371 zio_buf_free(lrbuf, SPA_OLD_MAXBLOCKSIZE); 372 373 return (error); 374 } 375 376 static int 377 zil_claim_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t first_txg) 378 { 379 /* 380 * Claim log block if not already committed and not already claimed. 381 * If tx == NULL, just verify that the block is claimable. 382 */ 383 if (BP_IS_HOLE(bp) || bp->blk_birth < first_txg || 384 zil_bp_tree_add(zilog, bp) != 0) 385 return (0); 386 387 return (zio_wait(zio_claim(NULL, zilog->zl_spa, 388 tx == NULL ? 0 : first_txg, bp, spa_claim_notify, NULL, 389 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB))); 390 } 391 392 static int 393 zil_claim_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t first_txg) 394 { 395 lr_write_t *lr = (lr_write_t *)lrc; 396 int error; 397 398 if (lrc->lrc_txtype != TX_WRITE) 399 return (0); 400 401 /* 402 * If the block is not readable, don't claim it. This can happen 403 * in normal operation when a log block is written to disk before 404 * some of the dmu_sync() blocks it points to. In this case, the 405 * transaction cannot have been committed to anyone (we would have 406 * waited for all writes to be stable first), so it is semantically 407 * correct to declare this the end of the log. 408 */ 409 if (lr->lr_blkptr.blk_birth >= first_txg && 410 (error = zil_read_log_data(zilog, lr, NULL)) != 0) 411 return (error); 412 return (zil_claim_log_block(zilog, &lr->lr_blkptr, tx, first_txg)); 413 } 414 415 /* ARGSUSED */ 416 static int 417 zil_free_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t claim_txg) 418 { 419 zio_free_zil(zilog->zl_spa, dmu_tx_get_txg(tx), bp); 420 421 return (0); 422 } 423 424 static int 425 zil_free_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t claim_txg) 426 { 427 lr_write_t *lr = (lr_write_t *)lrc; 428 blkptr_t *bp = &lr->lr_blkptr; 429 430 /* 431 * If we previously claimed it, we need to free it. 432 */ 433 if (claim_txg != 0 && lrc->lrc_txtype == TX_WRITE && 434 bp->blk_birth >= claim_txg && zil_bp_tree_add(zilog, bp) == 0 && 435 !BP_IS_HOLE(bp)) 436 zio_free(zilog->zl_spa, dmu_tx_get_txg(tx), bp); 437 438 return (0); 439 } 440 441 static lwb_t * 442 zil_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 */ 472 void 473 zilog_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 (ds->ds_is_snapshot) 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 } 486 487 /* 488 * Determine if the zil is dirty in the specified txg. Callers wanting to 489 * ensure that the dirty state does not change must hold the itxg_lock for 490 * the specified txg. Holding the lock will ensure that the zil cannot be 491 * dirtied (zil_itx_assign) or cleaned (zil_clean) while we check its current 492 * state. 493 */ 494 boolean_t 495 zilog_is_dirty_in_txg(zilog_t *zilog, uint64_t txg) 496 { 497 dsl_pool_t *dp = zilog->zl_dmu_pool; 498 499 if (txg_list_member(&dp->dp_dirty_zilogs, zilog, txg & TXG_MASK)) 500 return (B_TRUE); 501 return (B_FALSE); 502 } 503 504 /* 505 * Determine if the zil is dirty. The zil is considered dirty if it has 506 * any pending itx records that have not been cleaned by zil_clean(). 507 */ 508 boolean_t 509 zilog_is_dirty(zilog_t *zilog) 510 { 511 dsl_pool_t *dp = zilog->zl_dmu_pool; 512 513 for (int t = 0; t < TXG_SIZE; t++) { 514 if (txg_list_member(&dp->dp_dirty_zilogs, zilog, t)) 515 return (B_TRUE); 516 } 517 return (B_FALSE); 518 } 519 520 /* 521 * Create an on-disk intent log. 522 */ 523 static lwb_t * 524 zil_create(zilog_t *zilog) 525 { 526 const zil_header_t *zh = zilog->zl_header; 527 lwb_t *lwb = NULL; 528 uint64_t txg = 0; 529 dmu_tx_t *tx = NULL; 530 blkptr_t blk; 531 int error = 0; 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, zilog->zl_logbias == ZFS_LOGBIAS_LATENCY); 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, 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 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 881 mutex_enter(&zilog->zl_lock); 882 lwb->lwb_buf = NULL; 883 lwb->lwb_tx = NULL; 884 mutex_exit(&zilog->zl_lock); 885 886 /* 887 * Now that we've written this log block, we have a stable pointer 888 * to the next block in the chain, so it's OK to let the txg in 889 * which we allocated the next block sync. 890 */ 891 dmu_tx_commit(tx); 892 } 893 894 /* 895 * Initialize the io for a log block. 896 */ 897 static void 898 zil_lwb_write_init(zilog_t *zilog, lwb_t *lwb) 899 { 900 zbookmark_phys_t zb; 901 902 SET_BOOKMARK(&zb, lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_OBJSET], 903 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, 904 lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_SEQ]); 905 906 if (zilog->zl_root_zio == NULL) { 907 zilog->zl_root_zio = zio_root(zilog->zl_spa, NULL, NULL, 908 ZIO_FLAG_CANFAIL); 909 } 910 if (lwb->lwb_zio == NULL) { 911 lwb->lwb_zio = zio_rewrite(zilog->zl_root_zio, zilog->zl_spa, 912 0, &lwb->lwb_blk, lwb->lwb_buf, BP_GET_LSIZE(&lwb->lwb_blk), 913 zil_lwb_write_done, lwb, ZIO_PRIORITY_SYNC_WRITE, 914 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE, &zb); 915 } 916 } 917 918 /* 919 * Define a limited set of intent log block sizes. 920 * 921 * These must be a multiple of 4KB. Note only the amount used (again 922 * aligned to 4KB) actually gets written. However, we can't always just 923 * allocate SPA_OLD_MAXBLOCKSIZE as the slog space could be exhausted. 924 */ 925 uint64_t zil_block_buckets[] = { 926 4096, /* non TX_WRITE */ 927 8192+4096, /* data base */ 928 32*1024 + 4096, /* NFS writes */ 929 UINT64_MAX 930 }; 931 932 /* 933 * Use the slog as long as the logbias is 'latency' and the current commit size 934 * is less than the limit or the total list size is less than 2X the limit. 935 * Limit checking is disabled by setting zil_slog_limit to UINT64_MAX. 936 */ 937 uint64_t zil_slog_limit = 1024 * 1024; 938 #define USE_SLOG(zilog) (((zilog)->zl_logbias == ZFS_LOGBIAS_LATENCY) && \ 939 (((zilog)->zl_cur_used < zil_slog_limit) || \ 940 ((zilog)->zl_itx_list_sz < (zil_slog_limit << 1)))) 941 942 /* 943 * Start a log block write and advance to the next log block. 944 * Calls are serialized. 945 */ 946 static lwb_t * 947 zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb) 948 { 949 lwb_t *nlwb = NULL; 950 zil_chain_t *zilc; 951 spa_t *spa = zilog->zl_spa; 952 blkptr_t *bp; 953 dmu_tx_t *tx; 954 uint64_t txg; 955 uint64_t zil_blksz, wsz; 956 int i, error; 957 958 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) { 959 zilc = (zil_chain_t *)lwb->lwb_buf; 960 bp = &zilc->zc_next_blk; 961 } else { 962 zilc = (zil_chain_t *)(lwb->lwb_buf + lwb->lwb_sz); 963 bp = &zilc->zc_next_blk; 964 } 965 966 ASSERT(lwb->lwb_nused <= lwb->lwb_sz); 967 968 /* 969 * Allocate the next block and save its address in this block 970 * before writing it in order to establish the log chain. 971 * Note that if the allocation of nlwb synced before we wrote 972 * the block that points at it (lwb), we'd leak it if we crashed. 973 * Therefore, we don't do dmu_tx_commit() until zil_lwb_write_done(). 974 * We dirty the dataset to ensure that zil_sync() will be called 975 * to clean up in the event of allocation failure or I/O failure. 976 */ 977 tx = dmu_tx_create(zilog->zl_os); 978 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 979 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 980 txg = dmu_tx_get_txg(tx); 981 982 lwb->lwb_tx = tx; 983 984 /* 985 * Log blocks are pre-allocated. Here we select the size of the next 986 * block, based on size used in the last block. 987 * - first find the smallest bucket that will fit the block from a 988 * limited set of block sizes. This is because it's faster to write 989 * blocks allocated from the same metaslab as they are adjacent or 990 * close. 991 * - next find the maximum from the new suggested size and an array of 992 * previous sizes. This lessens a picket fence effect of wrongly 993 * guesssing the size if we have a stream of say 2k, 64k, 2k, 64k 994 * requests. 995 * 996 * Note we only write what is used, but we can't just allocate 997 * the maximum block size because we can exhaust the available 998 * pool log space. 999 */ 1000 zil_blksz = zilog->zl_cur_used + sizeof (zil_chain_t); 1001 for (i = 0; zil_blksz > zil_block_buckets[i]; i++) 1002 continue; 1003 zil_blksz = zil_block_buckets[i]; 1004 if (zil_blksz == UINT64_MAX) 1005 zil_blksz = SPA_OLD_MAXBLOCKSIZE; 1006 zilog->zl_prev_blks[zilog->zl_prev_rotor] = zil_blksz; 1007 for (i = 0; i < ZIL_PREV_BLKS; i++) 1008 zil_blksz = MAX(zil_blksz, zilog->zl_prev_blks[i]); 1009 zilog->zl_prev_rotor = (zilog->zl_prev_rotor + 1) & (ZIL_PREV_BLKS - 1); 1010 1011 BP_ZERO(bp); 1012 /* pass the old blkptr in order to spread log blocks across devs */ 1013 error = zio_alloc_zil(spa, txg, bp, &lwb->lwb_blk, zil_blksz, 1014 USE_SLOG(zilog)); 1015 if (error == 0) { 1016 ASSERT3U(bp->blk_birth, ==, txg); 1017 bp->blk_cksum = lwb->lwb_blk.blk_cksum; 1018 bp->blk_cksum.zc_word[ZIL_ZC_SEQ]++; 1019 1020 /* 1021 * Allocate a new log write buffer (lwb). 1022 */ 1023 nlwb = zil_alloc_lwb(zilog, bp, txg); 1024 1025 /* Record the block for later vdev flushing */ 1026 zil_add_block(zilog, &lwb->lwb_blk); 1027 } 1028 1029 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) { 1030 /* For Slim ZIL only write what is used. */ 1031 wsz = P2ROUNDUP_TYPED(lwb->lwb_nused, ZIL_MIN_BLKSZ, uint64_t); 1032 ASSERT3U(wsz, <=, lwb->lwb_sz); 1033 zio_shrink(lwb->lwb_zio, wsz); 1034 1035 } else { 1036 wsz = lwb->lwb_sz; 1037 } 1038 1039 zilc->zc_pad = 0; 1040 zilc->zc_nused = lwb->lwb_nused; 1041 zilc->zc_eck.zec_cksum = lwb->lwb_blk.blk_cksum; 1042 1043 /* 1044 * clear unused data for security 1045 */ 1046 bzero(lwb->lwb_buf + lwb->lwb_nused, wsz - lwb->lwb_nused); 1047 1048 zio_nowait(lwb->lwb_zio); /* Kick off the write for the old log block */ 1049 1050 /* 1051 * If there was an allocation failure then nlwb will be null which 1052 * forces a txg_wait_synced(). 1053 */ 1054 return (nlwb); 1055 } 1056 1057 static lwb_t * 1058 zil_lwb_commit(zilog_t *zilog, itx_t *itx, lwb_t *lwb) 1059 { 1060 lr_t *lrc = &itx->itx_lr; /* common log record */ 1061 lr_write_t *lrw = (lr_write_t *)lrc; 1062 char *lr_buf; 1063 uint64_t txg = lrc->lrc_txg; 1064 uint64_t reclen = lrc->lrc_reclen; 1065 uint64_t dlen = 0; 1066 1067 if (lwb == NULL) 1068 return (NULL); 1069 1070 ASSERT(lwb->lwb_buf != NULL); 1071 1072 if (lrc->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY) 1073 dlen = P2ROUNDUP_TYPED( 1074 lrw->lr_length, sizeof (uint64_t), uint64_t); 1075 1076 zilog->zl_cur_used += (reclen + dlen); 1077 1078 zil_lwb_write_init(zilog, lwb); 1079 1080 /* 1081 * If this record won't fit in the current log block, start a new one. 1082 */ 1083 if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) { 1084 lwb = zil_lwb_write_start(zilog, lwb); 1085 if (lwb == NULL) 1086 return (NULL); 1087 zil_lwb_write_init(zilog, lwb); 1088 ASSERT(LWB_EMPTY(lwb)); 1089 if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) { 1090 txg_wait_synced(zilog->zl_dmu_pool, txg); 1091 return (lwb); 1092 } 1093 } 1094 1095 lr_buf = lwb->lwb_buf + lwb->lwb_nused; 1096 bcopy(lrc, lr_buf, reclen); 1097 lrc = (lr_t *)lr_buf; 1098 lrw = (lr_write_t *)lrc; 1099 1100 /* 1101 * If it's a write, fetch the data or get its blkptr as appropriate. 1102 */ 1103 if (lrc->lrc_txtype == TX_WRITE) { 1104 if (txg > spa_freeze_txg(zilog->zl_spa)) 1105 txg_wait_synced(zilog->zl_dmu_pool, txg); 1106 if (itx->itx_wr_state != WR_COPIED) { 1107 char *dbuf; 1108 int error; 1109 1110 if (dlen) { 1111 ASSERT(itx->itx_wr_state == WR_NEED_COPY); 1112 dbuf = lr_buf + reclen; 1113 lrw->lr_common.lrc_reclen += dlen; 1114 } else { 1115 ASSERT(itx->itx_wr_state == WR_INDIRECT); 1116 dbuf = NULL; 1117 } 1118 error = zilog->zl_get_data( 1119 itx->itx_private, lrw, dbuf, lwb->lwb_zio); 1120 if (error == EIO) { 1121 txg_wait_synced(zilog->zl_dmu_pool, txg); 1122 return (lwb); 1123 } 1124 if (error != 0) { 1125 ASSERT(error == ENOENT || error == EEXIST || 1126 error == EALREADY); 1127 return (lwb); 1128 } 1129 } 1130 } 1131 1132 /* 1133 * We're actually making an entry, so update lrc_seq to be the 1134 * log record sequence number. Note that this is generally not 1135 * equal to the itx sequence number because not all transactions 1136 * are synchronous, and sometimes spa_sync() gets there first. 1137 */ 1138 lrc->lrc_seq = ++zilog->zl_lr_seq; /* we are single threaded */ 1139 lwb->lwb_nused += reclen + dlen; 1140 lwb->lwb_max_txg = MAX(lwb->lwb_max_txg, txg); 1141 ASSERT3U(lwb->lwb_nused, <=, lwb->lwb_sz); 1142 ASSERT0(P2PHASE(lwb->lwb_nused, sizeof (uint64_t))); 1143 1144 return (lwb); 1145 } 1146 1147 itx_t * 1148 zil_itx_create(uint64_t txtype, size_t lrsize) 1149 { 1150 itx_t *itx; 1151 1152 lrsize = P2ROUNDUP_TYPED(lrsize, sizeof (uint64_t), size_t); 1153 1154 itx = kmem_alloc(offsetof(itx_t, itx_lr) + lrsize, KM_SLEEP); 1155 itx->itx_lr.lrc_txtype = txtype; 1156 itx->itx_lr.lrc_reclen = lrsize; 1157 itx->itx_sod = lrsize; /* if write & WR_NEED_COPY will be increased */ 1158 itx->itx_lr.lrc_seq = 0; /* defensive */ 1159 itx->itx_sync = B_TRUE; /* default is synchronous */ 1160 1161 return (itx); 1162 } 1163 1164 void 1165 zil_itx_destroy(itx_t *itx) 1166 { 1167 kmem_free(itx, offsetof(itx_t, itx_lr) + itx->itx_lr.lrc_reclen); 1168 } 1169 1170 /* 1171 * Free up the sync and async itxs. The itxs_t has already been detached 1172 * so no locks are needed. 1173 */ 1174 static void 1175 zil_itxg_clean(itxs_t *itxs) 1176 { 1177 itx_t *itx; 1178 list_t *list; 1179 avl_tree_t *t; 1180 void *cookie; 1181 itx_async_node_t *ian; 1182 1183 list = &itxs->i_sync_list; 1184 while ((itx = list_head(list)) != NULL) { 1185 list_remove(list, itx); 1186 kmem_free(itx, offsetof(itx_t, itx_lr) + 1187 itx->itx_lr.lrc_reclen); 1188 } 1189 1190 cookie = NULL; 1191 t = &itxs->i_async_tree; 1192 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) { 1193 list = &ian->ia_list; 1194 while ((itx = list_head(list)) != NULL) { 1195 list_remove(list, itx); 1196 kmem_free(itx, offsetof(itx_t, itx_lr) + 1197 itx->itx_lr.lrc_reclen); 1198 } 1199 list_destroy(list); 1200 kmem_free(ian, sizeof (itx_async_node_t)); 1201 } 1202 avl_destroy(t); 1203 1204 kmem_free(itxs, sizeof (itxs_t)); 1205 } 1206 1207 static int 1208 zil_aitx_compare(const void *x1, const void *x2) 1209 { 1210 const uint64_t o1 = ((itx_async_node_t *)x1)->ia_foid; 1211 const uint64_t o2 = ((itx_async_node_t *)x2)->ia_foid; 1212 1213 if (o1 < o2) 1214 return (-1); 1215 if (o1 > o2) 1216 return (1); 1217 1218 return (0); 1219 } 1220 1221 /* 1222 * Remove all async itx with the given oid. 1223 */ 1224 static void 1225 zil_remove_async(zilog_t *zilog, uint64_t oid) 1226 { 1227 uint64_t otxg, txg; 1228 itx_async_node_t *ian; 1229 avl_tree_t *t; 1230 avl_index_t where; 1231 list_t clean_list; 1232 itx_t *itx; 1233 1234 ASSERT(oid != 0); 1235 list_create(&clean_list, sizeof (itx_t), offsetof(itx_t, itx_node)); 1236 1237 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1238 otxg = ZILTEST_TXG; 1239 else 1240 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1241 1242 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1243 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1244 1245 mutex_enter(&itxg->itxg_lock); 1246 if (itxg->itxg_txg != txg) { 1247 mutex_exit(&itxg->itxg_lock); 1248 continue; 1249 } 1250 1251 /* 1252 * Locate the object node and append its list. 1253 */ 1254 t = &itxg->itxg_itxs->i_async_tree; 1255 ian = avl_find(t, &oid, &where); 1256 if (ian != NULL) 1257 list_move_tail(&clean_list, &ian->ia_list); 1258 mutex_exit(&itxg->itxg_lock); 1259 } 1260 while ((itx = list_head(&clean_list)) != NULL) { 1261 list_remove(&clean_list, itx); 1262 kmem_free(itx, offsetof(itx_t, itx_lr) + 1263 itx->itx_lr.lrc_reclen); 1264 } 1265 list_destroy(&clean_list); 1266 } 1267 1268 void 1269 zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx) 1270 { 1271 uint64_t txg; 1272 itxg_t *itxg; 1273 itxs_t *itxs, *clean = NULL; 1274 1275 /* 1276 * Object ids can be re-instantiated in the next txg so 1277 * remove any async transactions to avoid future leaks. 1278 * This can happen if a fsync occurs on the re-instantiated 1279 * object for a WR_INDIRECT or WR_NEED_COPY write, which gets 1280 * the new file data and flushes a write record for the old object. 1281 */ 1282 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_REMOVE) 1283 zil_remove_async(zilog, itx->itx_oid); 1284 1285 /* 1286 * Ensure the data of a renamed file is committed before the rename. 1287 */ 1288 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_RENAME) 1289 zil_async_to_sync(zilog, itx->itx_oid); 1290 1291 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) 1292 txg = ZILTEST_TXG; 1293 else 1294 txg = dmu_tx_get_txg(tx); 1295 1296 itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1297 mutex_enter(&itxg->itxg_lock); 1298 itxs = itxg->itxg_itxs; 1299 if (itxg->itxg_txg != txg) { 1300 if (itxs != NULL) { 1301 /* 1302 * The zil_clean callback hasn't got around to cleaning 1303 * this itxg. Save the itxs for release below. 1304 * This should be rare. 1305 */ 1306 zfs_dbgmsg("zil_itx_assign: missed itx cleanup for " 1307 "txg %llu", itxg->itxg_txg); 1308 atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod); 1309 itxg->itxg_sod = 0; 1310 clean = itxg->itxg_itxs; 1311 } 1312 ASSERT(itxg->itxg_sod == 0); 1313 itxg->itxg_txg = txg; 1314 itxs = itxg->itxg_itxs = kmem_zalloc(sizeof (itxs_t), KM_SLEEP); 1315 1316 list_create(&itxs->i_sync_list, sizeof (itx_t), 1317 offsetof(itx_t, itx_node)); 1318 avl_create(&itxs->i_async_tree, zil_aitx_compare, 1319 sizeof (itx_async_node_t), 1320 offsetof(itx_async_node_t, ia_node)); 1321 } 1322 if (itx->itx_sync) { 1323 list_insert_tail(&itxs->i_sync_list, itx); 1324 atomic_add_64(&zilog->zl_itx_list_sz, itx->itx_sod); 1325 itxg->itxg_sod += itx->itx_sod; 1326 } else { 1327 avl_tree_t *t = &itxs->i_async_tree; 1328 uint64_t foid = ((lr_ooo_t *)&itx->itx_lr)->lr_foid; 1329 itx_async_node_t *ian; 1330 avl_index_t where; 1331 1332 ian = avl_find(t, &foid, &where); 1333 if (ian == NULL) { 1334 ian = kmem_alloc(sizeof (itx_async_node_t), KM_SLEEP); 1335 list_create(&ian->ia_list, sizeof (itx_t), 1336 offsetof(itx_t, itx_node)); 1337 ian->ia_foid = foid; 1338 avl_insert(t, ian, where); 1339 } 1340 list_insert_tail(&ian->ia_list, itx); 1341 } 1342 1343 itx->itx_lr.lrc_txg = dmu_tx_get_txg(tx); 1344 zilog_dirty(zilog, txg); 1345 mutex_exit(&itxg->itxg_lock); 1346 1347 /* Release the old itxs now we've dropped the lock */ 1348 if (clean != NULL) 1349 zil_itxg_clean(clean); 1350 } 1351 1352 /* 1353 * If there are any in-memory intent log transactions which have now been 1354 * synced then start up a taskq to free them. We should only do this after we 1355 * have written out the uberblocks (i.e. txg has been comitted) so that 1356 * don't inadvertently clean out in-memory log records that would be required 1357 * by zil_commit(). 1358 */ 1359 void 1360 zil_clean(zilog_t *zilog, uint64_t synced_txg) 1361 { 1362 itxg_t *itxg = &zilog->zl_itxg[synced_txg & TXG_MASK]; 1363 itxs_t *clean_me; 1364 1365 mutex_enter(&itxg->itxg_lock); 1366 if (itxg->itxg_itxs == NULL || itxg->itxg_txg == ZILTEST_TXG) { 1367 mutex_exit(&itxg->itxg_lock); 1368 return; 1369 } 1370 ASSERT3U(itxg->itxg_txg, <=, synced_txg); 1371 ASSERT(itxg->itxg_txg != 0); 1372 ASSERT(zilog->zl_clean_taskq != NULL); 1373 atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod); 1374 itxg->itxg_sod = 0; 1375 clean_me = itxg->itxg_itxs; 1376 itxg->itxg_itxs = NULL; 1377 itxg->itxg_txg = 0; 1378 mutex_exit(&itxg->itxg_lock); 1379 /* 1380 * Preferably start a task queue to free up the old itxs but 1381 * if taskq_dispatch can't allocate resources to do that then 1382 * free it in-line. This should be rare. Note, using TQ_SLEEP 1383 * created a bad performance problem. 1384 */ 1385 if (taskq_dispatch(zilog->zl_clean_taskq, 1386 (void (*)(void *))zil_itxg_clean, clean_me, TQ_NOSLEEP) == NULL) 1387 zil_itxg_clean(clean_me); 1388 } 1389 1390 /* 1391 * Get the list of itxs to commit into zl_itx_commit_list. 1392 */ 1393 static void 1394 zil_get_commit_list(zilog_t *zilog) 1395 { 1396 uint64_t otxg, txg; 1397 list_t *commit_list = &zilog->zl_itx_commit_list; 1398 uint64_t push_sod = 0; 1399 1400 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1401 otxg = ZILTEST_TXG; 1402 else 1403 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1404 1405 /* 1406 * This is inherently racy, since there is nothing to prevent 1407 * the last synced txg from changing. That's okay since we'll 1408 * only commit things in the future. 1409 */ 1410 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1411 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1412 1413 mutex_enter(&itxg->itxg_lock); 1414 if (itxg->itxg_txg != txg) { 1415 mutex_exit(&itxg->itxg_lock); 1416 continue; 1417 } 1418 1419 /* 1420 * If we're adding itx records to the zl_itx_commit_list, 1421 * then the zil better be dirty in this "txg". We can assert 1422 * that here since we're holding the itxg_lock which will 1423 * prevent spa_sync from cleaning it. Once we add the itxs 1424 * to the zl_itx_commit_list we must commit it to disk even 1425 * if it's unnecessary (i.e. the txg was synced). 1426 */ 1427 ASSERT(zilog_is_dirty_in_txg(zilog, txg) || 1428 spa_freeze_txg(zilog->zl_spa) != UINT64_MAX); 1429 list_move_tail(commit_list, &itxg->itxg_itxs->i_sync_list); 1430 push_sod += itxg->itxg_sod; 1431 itxg->itxg_sod = 0; 1432 1433 mutex_exit(&itxg->itxg_lock); 1434 } 1435 atomic_add_64(&zilog->zl_itx_list_sz, -push_sod); 1436 } 1437 1438 /* 1439 * Move the async itxs for a specified object to commit into sync lists. 1440 */ 1441 static void 1442 zil_async_to_sync(zilog_t *zilog, uint64_t foid) 1443 { 1444 uint64_t otxg, txg; 1445 itx_async_node_t *ian; 1446 avl_tree_t *t; 1447 avl_index_t where; 1448 1449 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1450 otxg = ZILTEST_TXG; 1451 else 1452 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1453 1454 /* 1455 * This is inherently racy, since there is nothing to prevent 1456 * the last synced txg from changing. 1457 */ 1458 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1459 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1460 1461 mutex_enter(&itxg->itxg_lock); 1462 if (itxg->itxg_txg != txg) { 1463 mutex_exit(&itxg->itxg_lock); 1464 continue; 1465 } 1466 1467 /* 1468 * If a foid is specified then find that node and append its 1469 * list. Otherwise walk the tree appending all the lists 1470 * to the sync list. We add to the end rather than the 1471 * beginning to ensure the create has happened. 1472 */ 1473 t = &itxg->itxg_itxs->i_async_tree; 1474 if (foid != 0) { 1475 ian = avl_find(t, &foid, &where); 1476 if (ian != NULL) { 1477 list_move_tail(&itxg->itxg_itxs->i_sync_list, 1478 &ian->ia_list); 1479 } 1480 } else { 1481 void *cookie = NULL; 1482 1483 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) { 1484 list_move_tail(&itxg->itxg_itxs->i_sync_list, 1485 &ian->ia_list); 1486 list_destroy(&ian->ia_list); 1487 kmem_free(ian, sizeof (itx_async_node_t)); 1488 } 1489 } 1490 mutex_exit(&itxg->itxg_lock); 1491 } 1492 } 1493 1494 static void 1495 zil_commit_writer(zilog_t *zilog) 1496 { 1497 uint64_t txg; 1498 itx_t *itx; 1499 lwb_t *lwb; 1500 spa_t *spa = zilog->zl_spa; 1501 int error = 0; 1502 1503 ASSERT(zilog->zl_root_zio == NULL); 1504 1505 mutex_exit(&zilog->zl_lock); 1506 1507 zil_get_commit_list(zilog); 1508 1509 /* 1510 * Return if there's nothing to commit before we dirty the fs by 1511 * calling zil_create(). 1512 */ 1513 if (list_head(&zilog->zl_itx_commit_list) == NULL) { 1514 mutex_enter(&zilog->zl_lock); 1515 return; 1516 } 1517 1518 if (zilog->zl_suspend) { 1519 lwb = NULL; 1520 } else { 1521 lwb = list_tail(&zilog->zl_lwb_list); 1522 if (lwb == NULL) 1523 lwb = zil_create(zilog); 1524 } 1525 1526 DTRACE_PROBE1(zil__cw1, zilog_t *, zilog); 1527 while (itx = list_head(&zilog->zl_itx_commit_list)) { 1528 txg = itx->itx_lr.lrc_txg; 1529 ASSERT3U(txg, !=, 0); 1530 1531 /* 1532 * This is inherently racy and may result in us writing 1533 * out a log block for a txg that was just synced. This is 1534 * ok since we'll end cleaning up that log block the next 1535 * time we call zil_sync(). 1536 */ 1537 if (txg > spa_last_synced_txg(spa) || txg > spa_freeze_txg(spa)) 1538 lwb = zil_lwb_commit(zilog, itx, lwb); 1539 list_remove(&zilog->zl_itx_commit_list, itx); 1540 kmem_free(itx, offsetof(itx_t, itx_lr) 1541 + itx->itx_lr.lrc_reclen); 1542 } 1543 DTRACE_PROBE1(zil__cw2, zilog_t *, zilog); 1544 1545 /* write the last block out */ 1546 if (lwb != NULL && lwb->lwb_zio != NULL) 1547 lwb = zil_lwb_write_start(zilog, lwb); 1548 1549 zilog->zl_cur_used = 0; 1550 1551 /* 1552 * Wait if necessary for the log blocks to be on stable storage. 1553 */ 1554 if (zilog->zl_root_zio) { 1555 error = zio_wait(zilog->zl_root_zio); 1556 zilog->zl_root_zio = NULL; 1557 zil_flush_vdevs(zilog); 1558 } 1559 1560 if (error || lwb == NULL) 1561 txg_wait_synced(zilog->zl_dmu_pool, 0); 1562 1563 mutex_enter(&zilog->zl_lock); 1564 1565 /* 1566 * Remember the highest committed log sequence number for ztest. 1567 * We only update this value when all the log writes succeeded, 1568 * because ztest wants to ASSERT that it got the whole log chain. 1569 */ 1570 if (error == 0 && lwb != NULL) 1571 zilog->zl_commit_lr_seq = zilog->zl_lr_seq; 1572 } 1573 1574 /* 1575 * Commit zfs transactions to stable storage. 1576 * If foid is 0 push out all transactions, otherwise push only those 1577 * for that object or might reference that object. 1578 * 1579 * itxs are committed in batches. In a heavily stressed zil there will be 1580 * a commit writer thread who is writing out a bunch of itxs to the log 1581 * for a set of committing threads (cthreads) in the same batch as the writer. 1582 * Those cthreads are all waiting on the same cv for that batch. 1583 * 1584 * There will also be a different and growing batch of threads that are 1585 * waiting to commit (qthreads). When the committing batch completes 1586 * a transition occurs such that the cthreads exit and the qthreads become 1587 * cthreads. One of the new cthreads becomes the writer thread for the 1588 * batch. Any new threads arriving become new qthreads. 1589 * 1590 * Only 2 condition variables are needed and there's no transition 1591 * between the two cvs needed. They just flip-flop between qthreads 1592 * and cthreads. 1593 * 1594 * Using this scheme we can efficiently wakeup up only those threads 1595 * that have been committed. 1596 */ 1597 void 1598 zil_commit(zilog_t *zilog, uint64_t foid) 1599 { 1600 uint64_t mybatch; 1601 1602 if (zilog->zl_sync == ZFS_SYNC_DISABLED) 1603 return; 1604 1605 /* move the async itxs for the foid to the sync queues */ 1606 zil_async_to_sync(zilog, foid); 1607 1608 mutex_enter(&zilog->zl_lock); 1609 mybatch = zilog->zl_next_batch; 1610 while (zilog->zl_writer) { 1611 cv_wait(&zilog->zl_cv_batch[mybatch & 1], &zilog->zl_lock); 1612 if (mybatch <= zilog->zl_com_batch) { 1613 mutex_exit(&zilog->zl_lock); 1614 return; 1615 } 1616 } 1617 1618 zilog->zl_next_batch++; 1619 zilog->zl_writer = B_TRUE; 1620 zil_commit_writer(zilog); 1621 zilog->zl_com_batch = mybatch; 1622 zilog->zl_writer = B_FALSE; 1623 mutex_exit(&zilog->zl_lock); 1624 1625 /* wake up one thread to become the next writer */ 1626 cv_signal(&zilog->zl_cv_batch[(mybatch+1) & 1]); 1627 1628 /* wake up all threads waiting for this batch to be committed */ 1629 cv_broadcast(&zilog->zl_cv_batch[mybatch & 1]); 1630 } 1631 1632 /* 1633 * Called in syncing context to free committed log blocks and update log header. 1634 */ 1635 void 1636 zil_sync(zilog_t *zilog, dmu_tx_t *tx) 1637 { 1638 zil_header_t *zh = zil_header_in_syncing_context(zilog); 1639 uint64_t txg = dmu_tx_get_txg(tx); 1640 spa_t *spa = zilog->zl_spa; 1641 uint64_t *replayed_seq = &zilog->zl_replayed_seq[txg & TXG_MASK]; 1642 lwb_t *lwb; 1643 1644 /* 1645 * We don't zero out zl_destroy_txg, so make sure we don't try 1646 * to destroy it twice. 1647 */ 1648 if (spa_sync_pass(spa) != 1) 1649 return; 1650 1651 mutex_enter(&zilog->zl_lock); 1652 1653 ASSERT(zilog->zl_stop_sync == 0); 1654 1655 if (*replayed_seq != 0) { 1656 ASSERT(zh->zh_replay_seq < *replayed_seq); 1657 zh->zh_replay_seq = *replayed_seq; 1658 *replayed_seq = 0; 1659 } 1660 1661 if (zilog->zl_destroy_txg == txg) { 1662 blkptr_t blk = zh->zh_log; 1663 1664 ASSERT(list_head(&zilog->zl_lwb_list) == NULL); 1665 1666 bzero(zh, sizeof (zil_header_t)); 1667 bzero(zilog->zl_replayed_seq, sizeof (zilog->zl_replayed_seq)); 1668 1669 if (zilog->zl_keep_first) { 1670 /* 1671 * If this block was part of log chain that couldn't 1672 * be claimed because a device was missing during 1673 * zil_claim(), but that device later returns, 1674 * then this block could erroneously appear valid. 1675 * To guard against this, assign a new GUID to the new 1676 * log chain so it doesn't matter what blk points to. 1677 */ 1678 zil_init_log_chain(zilog, &blk); 1679 zh->zh_log = blk; 1680 } 1681 } 1682 1683 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { 1684 zh->zh_log = lwb->lwb_blk; 1685 if (lwb->lwb_buf != NULL || lwb->lwb_max_txg > txg) 1686 break; 1687 list_remove(&zilog->zl_lwb_list, lwb); 1688 zio_free_zil(spa, txg, &lwb->lwb_blk); 1689 kmem_cache_free(zil_lwb_cache, lwb); 1690 1691 /* 1692 * If we don't have anything left in the lwb list then 1693 * we've had an allocation failure and we need to zero 1694 * out the zil_header blkptr so that we don't end 1695 * up freeing the same block twice. 1696 */ 1697 if (list_head(&zilog->zl_lwb_list) == NULL) 1698 BP_ZERO(&zh->zh_log); 1699 } 1700 mutex_exit(&zilog->zl_lock); 1701 } 1702 1703 void 1704 zil_init(void) 1705 { 1706 zil_lwb_cache = kmem_cache_create("zil_lwb_cache", 1707 sizeof (struct lwb), 0, NULL, NULL, NULL, NULL, NULL, 0); 1708 } 1709 1710 void 1711 zil_fini(void) 1712 { 1713 kmem_cache_destroy(zil_lwb_cache); 1714 } 1715 1716 void 1717 zil_set_sync(zilog_t *zilog, uint64_t sync) 1718 { 1719 zilog->zl_sync = sync; 1720 } 1721 1722 void 1723 zil_set_logbias(zilog_t *zilog, uint64_t logbias) 1724 { 1725 zilog->zl_logbias = logbias; 1726 } 1727 1728 zilog_t * 1729 zil_alloc(objset_t *os, zil_header_t *zh_phys) 1730 { 1731 zilog_t *zilog; 1732 1733 zilog = kmem_zalloc(sizeof (zilog_t), KM_SLEEP); 1734 1735 zilog->zl_header = zh_phys; 1736 zilog->zl_os = os; 1737 zilog->zl_spa = dmu_objset_spa(os); 1738 zilog->zl_dmu_pool = dmu_objset_pool(os); 1739 zilog->zl_destroy_txg = TXG_INITIAL - 1; 1740 zilog->zl_logbias = dmu_objset_logbias(os); 1741 zilog->zl_sync = dmu_objset_syncprop(os); 1742 zilog->zl_next_batch = 1; 1743 1744 mutex_init(&zilog->zl_lock, NULL, MUTEX_DEFAULT, NULL); 1745 1746 for (int i = 0; i < TXG_SIZE; i++) { 1747 mutex_init(&zilog->zl_itxg[i].itxg_lock, NULL, 1748 MUTEX_DEFAULT, NULL); 1749 } 1750 1751 list_create(&zilog->zl_lwb_list, sizeof (lwb_t), 1752 offsetof(lwb_t, lwb_node)); 1753 1754 list_create(&zilog->zl_itx_commit_list, sizeof (itx_t), 1755 offsetof(itx_t, itx_node)); 1756 1757 mutex_init(&zilog->zl_vdev_lock, NULL, MUTEX_DEFAULT, NULL); 1758 1759 avl_create(&zilog->zl_vdev_tree, zil_vdev_compare, 1760 sizeof (zil_vdev_node_t), offsetof(zil_vdev_node_t, zv_node)); 1761 1762 cv_init(&zilog->zl_cv_writer, NULL, CV_DEFAULT, NULL); 1763 cv_init(&zilog->zl_cv_suspend, NULL, CV_DEFAULT, NULL); 1764 cv_init(&zilog->zl_cv_batch[0], NULL, CV_DEFAULT, NULL); 1765 cv_init(&zilog->zl_cv_batch[1], NULL, CV_DEFAULT, NULL); 1766 1767 return (zilog); 1768 } 1769 1770 void 1771 zil_free(zilog_t *zilog) 1772 { 1773 zilog->zl_stop_sync = 1; 1774 1775 ASSERT0(zilog->zl_suspend); 1776 ASSERT0(zilog->zl_suspending); 1777 1778 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 1779 list_destroy(&zilog->zl_lwb_list); 1780 1781 avl_destroy(&zilog->zl_vdev_tree); 1782 mutex_destroy(&zilog->zl_vdev_lock); 1783 1784 ASSERT(list_is_empty(&zilog->zl_itx_commit_list)); 1785 list_destroy(&zilog->zl_itx_commit_list); 1786 1787 for (int i = 0; i < TXG_SIZE; i++) { 1788 /* 1789 * It's possible for an itx to be generated that doesn't dirty 1790 * a txg (e.g. ztest TX_TRUNCATE). So there's no zil_clean() 1791 * callback to remove the entry. We remove those here. 1792 * 1793 * Also free up the ziltest itxs. 1794 */ 1795 if (zilog->zl_itxg[i].itxg_itxs) 1796 zil_itxg_clean(zilog->zl_itxg[i].itxg_itxs); 1797 mutex_destroy(&zilog->zl_itxg[i].itxg_lock); 1798 } 1799 1800 mutex_destroy(&zilog->zl_lock); 1801 1802 cv_destroy(&zilog->zl_cv_writer); 1803 cv_destroy(&zilog->zl_cv_suspend); 1804 cv_destroy(&zilog->zl_cv_batch[0]); 1805 cv_destroy(&zilog->zl_cv_batch[1]); 1806 1807 kmem_free(zilog, sizeof (zilog_t)); 1808 } 1809 1810 /* 1811 * Open an intent log. 1812 */ 1813 zilog_t * 1814 zil_open(objset_t *os, zil_get_data_t *get_data) 1815 { 1816 zilog_t *zilog = dmu_objset_zil(os); 1817 1818 ASSERT(zilog->zl_clean_taskq == NULL); 1819 ASSERT(zilog->zl_get_data == NULL); 1820 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 1821 1822 zilog->zl_get_data = get_data; 1823 zilog->zl_clean_taskq = taskq_create("zil_clean", 1, minclsyspri, 1824 2, 2, TASKQ_PREPOPULATE); 1825 1826 return (zilog); 1827 } 1828 1829 /* 1830 * Close an intent log. 1831 */ 1832 void 1833 zil_close(zilog_t *zilog) 1834 { 1835 lwb_t *lwb; 1836 uint64_t txg = 0; 1837 1838 zil_commit(zilog, 0); /* commit all itx */ 1839 1840 /* 1841 * The lwb_max_txg for the stubby lwb will reflect the last activity 1842 * for the zil. After a txg_wait_synced() on the txg we know all the 1843 * callbacks have occurred that may clean the zil. Only then can we 1844 * destroy the zl_clean_taskq. 1845 */ 1846 mutex_enter(&zilog->zl_lock); 1847 lwb = list_tail(&zilog->zl_lwb_list); 1848 if (lwb != NULL) 1849 txg = lwb->lwb_max_txg; 1850 mutex_exit(&zilog->zl_lock); 1851 if (txg) 1852 txg_wait_synced(zilog->zl_dmu_pool, txg); 1853 1854 if (zilog_is_dirty(zilog)) 1855 zfs_dbgmsg("zil (%p) is dirty, txg %llu", zilog, txg); 1856 VERIFY(!zilog_is_dirty(zilog)); 1857 1858 taskq_destroy(zilog->zl_clean_taskq); 1859 zilog->zl_clean_taskq = NULL; 1860 zilog->zl_get_data = NULL; 1861 1862 /* 1863 * We should have only one LWB left on the list; remove it now. 1864 */ 1865 mutex_enter(&zilog->zl_lock); 1866 lwb = list_head(&zilog->zl_lwb_list); 1867 if (lwb != NULL) { 1868 ASSERT(lwb == list_tail(&zilog->zl_lwb_list)); 1869 list_remove(&zilog->zl_lwb_list, lwb); 1870 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 1871 kmem_cache_free(zil_lwb_cache, lwb); 1872 } 1873 mutex_exit(&zilog->zl_lock); 1874 } 1875 1876 static char *suspend_tag = "zil suspending"; 1877 1878 /* 1879 * Suspend an intent log. While in suspended mode, we still honor 1880 * synchronous semantics, but we rely on txg_wait_synced() to do it. 1881 * On old version pools, we suspend the log briefly when taking a 1882 * snapshot so that it will have an empty intent log. 1883 * 1884 * Long holds are not really intended to be used the way we do here -- 1885 * held for such a short time. A concurrent caller of dsl_dataset_long_held() 1886 * could fail. Therefore we take pains to only put a long hold if it is 1887 * actually necessary. Fortunately, it will only be necessary if the 1888 * objset is currently mounted (or the ZVOL equivalent). In that case it 1889 * will already have a long hold, so we are not really making things any worse. 1890 * 1891 * Ideally, we would locate the existing long-holder (i.e. the zfsvfs_t or 1892 * zvol_state_t), and use their mechanism to prevent their hold from being 1893 * dropped (e.g. VFS_HOLD()). However, that would be even more pain for 1894 * very little gain. 1895 * 1896 * if cookiep == NULL, this does both the suspend & resume. 1897 * Otherwise, it returns with the dataset "long held", and the cookie 1898 * should be passed into zil_resume(). 1899 */ 1900 int 1901 zil_suspend(const char *osname, void **cookiep) 1902 { 1903 objset_t *os; 1904 zilog_t *zilog; 1905 const zil_header_t *zh; 1906 int error; 1907 1908 error = dmu_objset_hold(osname, suspend_tag, &os); 1909 if (error != 0) 1910 return (error); 1911 zilog = dmu_objset_zil(os); 1912 1913 mutex_enter(&zilog->zl_lock); 1914 zh = zilog->zl_header; 1915 1916 if (zh->zh_flags & ZIL_REPLAY_NEEDED) { /* unplayed log */ 1917 mutex_exit(&zilog->zl_lock); 1918 dmu_objset_rele(os, suspend_tag); 1919 return (SET_ERROR(EBUSY)); 1920 } 1921 1922 /* 1923 * Don't put a long hold in the cases where we can avoid it. This 1924 * is when there is no cookie so we are doing a suspend & resume 1925 * (i.e. called from zil_vdev_offline()), and there's nothing to do 1926 * for the suspend because it's already suspended, or there's no ZIL. 1927 */ 1928 if (cookiep == NULL && !zilog->zl_suspending && 1929 (zilog->zl_suspend > 0 || BP_IS_HOLE(&zh->zh_log))) { 1930 mutex_exit(&zilog->zl_lock); 1931 dmu_objset_rele(os, suspend_tag); 1932 return (0); 1933 } 1934 1935 dsl_dataset_long_hold(dmu_objset_ds(os), suspend_tag); 1936 dsl_pool_rele(dmu_objset_pool(os), suspend_tag); 1937 1938 zilog->zl_suspend++; 1939 1940 if (zilog->zl_suspend > 1) { 1941 /* 1942 * Someone else is already suspending it. 1943 * Just wait for them to finish. 1944 */ 1945 1946 while (zilog->zl_suspending) 1947 cv_wait(&zilog->zl_cv_suspend, &zilog->zl_lock); 1948 mutex_exit(&zilog->zl_lock); 1949 1950 if (cookiep == NULL) 1951 zil_resume(os); 1952 else 1953 *cookiep = os; 1954 return (0); 1955 } 1956 1957 /* 1958 * If there is no pointer to an on-disk block, this ZIL must not 1959 * be active (e.g. filesystem not mounted), so there's nothing 1960 * to clean up. 1961 */ 1962 if (BP_IS_HOLE(&zh->zh_log)) { 1963 ASSERT(cookiep != NULL); /* fast path already handled */ 1964 1965 *cookiep = os; 1966 mutex_exit(&zilog->zl_lock); 1967 return (0); 1968 } 1969 1970 zilog->zl_suspending = B_TRUE; 1971 mutex_exit(&zilog->zl_lock); 1972 1973 zil_commit(zilog, 0); 1974 1975 zil_destroy(zilog, B_FALSE); 1976 1977 mutex_enter(&zilog->zl_lock); 1978 zilog->zl_suspending = B_FALSE; 1979 cv_broadcast(&zilog->zl_cv_suspend); 1980 mutex_exit(&zilog->zl_lock); 1981 1982 if (cookiep == NULL) 1983 zil_resume(os); 1984 else 1985 *cookiep = os; 1986 return (0); 1987 } 1988 1989 void 1990 zil_resume(void *cookie) 1991 { 1992 objset_t *os = cookie; 1993 zilog_t *zilog = dmu_objset_zil(os); 1994 1995 mutex_enter(&zilog->zl_lock); 1996 ASSERT(zilog->zl_suspend != 0); 1997 zilog->zl_suspend--; 1998 mutex_exit(&zilog->zl_lock); 1999 dsl_dataset_long_rele(dmu_objset_ds(os), suspend_tag); 2000 dsl_dataset_rele(dmu_objset_ds(os), suspend_tag); 2001 } 2002 2003 typedef struct zil_replay_arg { 2004 zil_replay_func_t **zr_replay; 2005 void *zr_arg; 2006 boolean_t zr_byteswap; 2007 char *zr_lr; 2008 } zil_replay_arg_t; 2009 2010 static int 2011 zil_replay_error(zilog_t *zilog, lr_t *lr, int error) 2012 { 2013 char name[ZFS_MAX_DATASET_NAME_LEN]; 2014 2015 zilog->zl_replaying_seq--; /* didn't actually replay this one */ 2016 2017 dmu_objset_name(zilog->zl_os, name); 2018 2019 cmn_err(CE_WARN, "ZFS replay transaction error %d, " 2020 "dataset %s, seq 0x%llx, txtype %llu %s\n", error, name, 2021 (u_longlong_t)lr->lrc_seq, 2022 (u_longlong_t)(lr->lrc_txtype & ~TX_CI), 2023 (lr->lrc_txtype & TX_CI) ? "CI" : ""); 2024 2025 return (error); 2026 } 2027 2028 static int 2029 zil_replay_log_record(zilog_t *zilog, lr_t *lr, void *zra, uint64_t claim_txg) 2030 { 2031 zil_replay_arg_t *zr = zra; 2032 const zil_header_t *zh = zilog->zl_header; 2033 uint64_t reclen = lr->lrc_reclen; 2034 uint64_t txtype = lr->lrc_txtype; 2035 int error = 0; 2036 2037 zilog->zl_replaying_seq = lr->lrc_seq; 2038 2039 if (lr->lrc_seq <= zh->zh_replay_seq) /* already replayed */ 2040 return (0); 2041 2042 if (lr->lrc_txg < claim_txg) /* already committed */ 2043 return (0); 2044 2045 /* Strip case-insensitive bit, still present in log record */ 2046 txtype &= ~TX_CI; 2047 2048 if (txtype == 0 || txtype >= TX_MAX_TYPE) 2049 return (zil_replay_error(zilog, lr, EINVAL)); 2050 2051 /* 2052 * If this record type can be logged out of order, the object 2053 * (lr_foid) may no longer exist. That's legitimate, not an error. 2054 */ 2055 if (TX_OOO(txtype)) { 2056 error = dmu_object_info(zilog->zl_os, 2057 ((lr_ooo_t *)lr)->lr_foid, NULL); 2058 if (error == ENOENT || error == EEXIST) 2059 return (0); 2060 } 2061 2062 /* 2063 * Make a copy of the data so we can revise and extend it. 2064 */ 2065 bcopy(lr, zr->zr_lr, reclen); 2066 2067 /* 2068 * If this is a TX_WRITE with a blkptr, suck in the data. 2069 */ 2070 if (txtype == TX_WRITE && reclen == sizeof (lr_write_t)) { 2071 error = zil_read_log_data(zilog, (lr_write_t *)lr, 2072 zr->zr_lr + reclen); 2073 if (error != 0) 2074 return (zil_replay_error(zilog, lr, error)); 2075 } 2076 2077 /* 2078 * The log block containing this lr may have been byteswapped 2079 * so that we can easily examine common fields like lrc_txtype. 2080 * However, the log is a mix of different record types, and only the 2081 * replay vectors know how to byteswap their records. Therefore, if 2082 * the lr was byteswapped, undo it before invoking the replay vector. 2083 */ 2084 if (zr->zr_byteswap) 2085 byteswap_uint64_array(zr->zr_lr, reclen); 2086 2087 /* 2088 * We must now do two things atomically: replay this log record, 2089 * and update the log header sequence number to reflect the fact that 2090 * we did so. At the end of each replay function the sequence number 2091 * is updated if we are in replay mode. 2092 */ 2093 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, zr->zr_byteswap); 2094 if (error != 0) { 2095 /* 2096 * The DMU's dnode layer doesn't see removes until the txg 2097 * commits, so a subsequent claim can spuriously fail with 2098 * EEXIST. So if we receive any error we try syncing out 2099 * any removes then retry the transaction. Note that we 2100 * specify B_FALSE for byteswap now, so we don't do it twice. 2101 */ 2102 txg_wait_synced(spa_get_dsl(zilog->zl_spa), 0); 2103 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, B_FALSE); 2104 if (error != 0) 2105 return (zil_replay_error(zilog, lr, error)); 2106 } 2107 return (0); 2108 } 2109 2110 /* ARGSUSED */ 2111 static int 2112 zil_incr_blks(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg) 2113 { 2114 zilog->zl_replay_blks++; 2115 2116 return (0); 2117 } 2118 2119 /* 2120 * If this dataset has a non-empty intent log, replay it and destroy it. 2121 */ 2122 void 2123 zil_replay(objset_t *os, void *arg, zil_replay_func_t *replay_func[TX_MAX_TYPE]) 2124 { 2125 zilog_t *zilog = dmu_objset_zil(os); 2126 const zil_header_t *zh = zilog->zl_header; 2127 zil_replay_arg_t zr; 2128 2129 if ((zh->zh_flags & ZIL_REPLAY_NEEDED) == 0) { 2130 zil_destroy(zilog, B_TRUE); 2131 return; 2132 } 2133 2134 zr.zr_replay = replay_func; 2135 zr.zr_arg = arg; 2136 zr.zr_byteswap = BP_SHOULD_BYTESWAP(&zh->zh_log); 2137 zr.zr_lr = kmem_alloc(2 * SPA_MAXBLOCKSIZE, KM_SLEEP); 2138 2139 /* 2140 * Wait for in-progress removes to sync before starting replay. 2141 */ 2142 txg_wait_synced(zilog->zl_dmu_pool, 0); 2143 2144 zilog->zl_replay = B_TRUE; 2145 zilog->zl_replay_time = ddi_get_lbolt(); 2146 ASSERT(zilog->zl_replay_blks == 0); 2147 (void) zil_parse(zilog, zil_incr_blks, zil_replay_log_record, &zr, 2148 zh->zh_claim_txg); 2149 kmem_free(zr.zr_lr, 2 * SPA_MAXBLOCKSIZE); 2150 2151 zil_destroy(zilog, B_FALSE); 2152 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 2153 zilog->zl_replay = B_FALSE; 2154 } 2155 2156 boolean_t 2157 zil_replaying(zilog_t *zilog, dmu_tx_t *tx) 2158 { 2159 if (zilog->zl_sync == ZFS_SYNC_DISABLED) 2160 return (B_TRUE); 2161 2162 if (zilog->zl_replay) { 2163 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 2164 zilog->zl_replayed_seq[dmu_tx_get_txg(tx) & TXG_MASK] = 2165 zilog->zl_replaying_seq; 2166 return (B_TRUE); 2167 } 2168 2169 return (B_FALSE); 2170 } 2171 2172 /* ARGSUSED */ 2173 int 2174 zil_vdev_offline(const char *osname, void *arg) 2175 { 2176 int error; 2177 2178 error = zil_suspend(osname, NULL); 2179 if (error != 0) 2180 return (SET_ERROR(EEXIST)); 2181 return (0); 2182 } 2183