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 2009 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #include <sys/zfs_context.h> 27 #include <sys/spa.h> 28 #include <sys/dmu.h> 29 #include <sys/zap.h> 30 #include <sys/arc.h> 31 #include <sys/stat.h> 32 #include <sys/resource.h> 33 #include <sys/zil.h> 34 #include <sys/zil_impl.h> 35 #include <sys/dsl_dataset.h> 36 #include <sys/vdev.h> 37 #include <sys/dmu_tx.h> 38 39 /* 40 * The zfs intent log (ZIL) saves transaction records of system calls 41 * that change the file system in memory with enough information 42 * to be able to replay them. These are stored in memory until 43 * either the DMU transaction group (txg) commits them to the stable pool 44 * and they can be discarded, or they are flushed to the stable log 45 * (also in the pool) due to a fsync, O_DSYNC or other synchronous 46 * requirement. In the event of a panic or power fail then those log 47 * records (transactions) are replayed. 48 * 49 * There is one ZIL per file system. Its on-disk (pool) format consists 50 * of 3 parts: 51 * 52 * - ZIL header 53 * - ZIL blocks 54 * - ZIL records 55 * 56 * A log record holds a system call transaction. Log blocks can 57 * hold many log records and the blocks are chained together. 58 * Each ZIL block contains a block pointer (blkptr_t) to the next 59 * ZIL block in the chain. The ZIL header points to the first 60 * block in the chain. Note there is not a fixed place in the pool 61 * to hold blocks. They are dynamically allocated and freed as 62 * needed from the blocks available. Figure X shows the ZIL structure: 63 */ 64 65 /* 66 * This global ZIL switch affects all pools 67 */ 68 int zil_disable = 0; /* disable intent logging */ 69 70 /* 71 * Tunable parameter for debugging or performance analysis. Setting 72 * zfs_nocacheflush will cause corruption on power loss if a volatile 73 * out-of-order write cache is enabled. 74 */ 75 boolean_t zfs_nocacheflush = B_FALSE; 76 77 static kmem_cache_t *zil_lwb_cache; 78 79 static boolean_t zil_empty(zilog_t *zilog); 80 81 static int 82 zil_bp_compare(const void *x1, const void *x2) 83 { 84 const dva_t *dva1 = &((zil_bp_node_t *)x1)->zn_dva; 85 const dva_t *dva2 = &((zil_bp_node_t *)x2)->zn_dva; 86 87 if (DVA_GET_VDEV(dva1) < DVA_GET_VDEV(dva2)) 88 return (-1); 89 if (DVA_GET_VDEV(dva1) > DVA_GET_VDEV(dva2)) 90 return (1); 91 92 if (DVA_GET_OFFSET(dva1) < DVA_GET_OFFSET(dva2)) 93 return (-1); 94 if (DVA_GET_OFFSET(dva1) > DVA_GET_OFFSET(dva2)) 95 return (1); 96 97 return (0); 98 } 99 100 static void 101 zil_bp_tree_init(zilog_t *zilog) 102 { 103 avl_create(&zilog->zl_bp_tree, zil_bp_compare, 104 sizeof (zil_bp_node_t), offsetof(zil_bp_node_t, zn_node)); 105 } 106 107 static void 108 zil_bp_tree_fini(zilog_t *zilog) 109 { 110 avl_tree_t *t = &zilog->zl_bp_tree; 111 zil_bp_node_t *zn; 112 void *cookie = NULL; 113 114 while ((zn = avl_destroy_nodes(t, &cookie)) != NULL) 115 kmem_free(zn, sizeof (zil_bp_node_t)); 116 117 avl_destroy(t); 118 } 119 120 int 121 zil_bp_tree_add(zilog_t *zilog, const blkptr_t *bp) 122 { 123 avl_tree_t *t = &zilog->zl_bp_tree; 124 const dva_t *dva = BP_IDENTITY(bp); 125 zil_bp_node_t *zn; 126 avl_index_t where; 127 128 if (avl_find(t, dva, &where) != NULL) 129 return (EEXIST); 130 131 zn = kmem_alloc(sizeof (zil_bp_node_t), KM_SLEEP); 132 zn->zn_dva = *dva; 133 avl_insert(t, zn, where); 134 135 return (0); 136 } 137 138 static zil_header_t * 139 zil_header_in_syncing_context(zilog_t *zilog) 140 { 141 return ((zil_header_t *)zilog->zl_header); 142 } 143 144 static void 145 zil_init_log_chain(zilog_t *zilog, blkptr_t *bp) 146 { 147 zio_cksum_t *zc = &bp->blk_cksum; 148 149 zc->zc_word[ZIL_ZC_GUID_0] = spa_get_random(-1ULL); 150 zc->zc_word[ZIL_ZC_GUID_1] = spa_get_random(-1ULL); 151 zc->zc_word[ZIL_ZC_OBJSET] = dmu_objset_id(zilog->zl_os); 152 zc->zc_word[ZIL_ZC_SEQ] = 1ULL; 153 } 154 155 /* 156 * Read a log block and make sure it's valid. 157 */ 158 static int 159 zil_read_log_block(zilog_t *zilog, const blkptr_t *bp, blkptr_t *nbp, void *dst) 160 { 161 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL; 162 uint32_t aflags = ARC_WAIT; 163 arc_buf_t *abuf = NULL; 164 zbookmark_t zb; 165 int error; 166 167 if (zilog->zl_header->zh_claim_txg == 0) 168 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; 169 170 if (!(zilog->zl_header->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) 171 zio_flags |= ZIO_FLAG_SPECULATIVE; 172 173 SET_BOOKMARK(&zb, bp->blk_cksum.zc_word[ZIL_ZC_OBJSET], 174 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]); 175 176 error = arc_read_nolock(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf, 177 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); 178 179 if (error == 0) { 180 char *data = abuf->b_data; 181 uint64_t size = BP_GET_LSIZE(bp); 182 zil_trailer_t *ztp = (zil_trailer_t *)(data + size) - 1; 183 zio_cksum_t cksum = bp->blk_cksum; 184 185 bcopy(data, dst, size); 186 *nbp = ztp->zit_next_blk; 187 188 /* 189 * Validate the checksummed log block. 190 * 191 * Sequence numbers should be... sequential. The checksum 192 * verifier for the next block should be bp's checksum plus 1. 193 * 194 * Also check the log chain linkage and size used. 195 */ 196 cksum.zc_word[ZIL_ZC_SEQ]++; 197 198 if (bcmp(&cksum, &ztp->zit_next_blk.blk_cksum, 199 sizeof (cksum)) || BP_IS_HOLE(&ztp->zit_next_blk) || 200 (ztp->zit_nused > (size - sizeof (zil_trailer_t)))) 201 error = ECKSUM; 202 203 VERIFY(arc_buf_remove_ref(abuf, &abuf) == 1); 204 } 205 206 return (error); 207 } 208 209 /* 210 * Read a TX_WRITE log data block. 211 */ 212 static int 213 zil_read_log_data(zilog_t *zilog, const lr_write_t *lr, void *wbuf) 214 { 215 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL; 216 const blkptr_t *bp = &lr->lr_blkptr; 217 uint32_t aflags = ARC_WAIT; 218 arc_buf_t *abuf = NULL; 219 zbookmark_t zb; 220 int error; 221 222 if (BP_IS_HOLE(bp)) { 223 if (wbuf != NULL) 224 bzero(wbuf, MAX(BP_GET_LSIZE(bp), lr->lr_length)); 225 return (0); 226 } 227 228 if (zilog->zl_header->zh_claim_txg == 0) 229 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; 230 231 SET_BOOKMARK(&zb, dmu_objset_id(zilog->zl_os), lr->lr_foid, 232 ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp)); 233 234 error = arc_read_nolock(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf, 235 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); 236 237 if (error == 0) { 238 if (wbuf != NULL) 239 bcopy(abuf->b_data, wbuf, arc_buf_size(abuf)); 240 (void) arc_buf_remove_ref(abuf, &abuf); 241 } 242 243 return (error); 244 } 245 246 /* 247 * Parse the intent log, and call parse_func for each valid record within. 248 */ 249 int 250 zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func, 251 zil_parse_lr_func_t *parse_lr_func, void *arg, uint64_t txg) 252 { 253 const zil_header_t *zh = zilog->zl_header; 254 boolean_t claimed = !!zh->zh_claim_txg; 255 uint64_t claim_blk_seq = claimed ? zh->zh_claim_blk_seq : UINT64_MAX; 256 uint64_t claim_lr_seq = claimed ? zh->zh_claim_lr_seq : UINT64_MAX; 257 uint64_t max_blk_seq = 0; 258 uint64_t max_lr_seq = 0; 259 uint64_t blk_count = 0; 260 uint64_t lr_count = 0; 261 blkptr_t blk, next_blk; 262 char *lrbuf, *lrp; 263 int error = 0; 264 265 /* 266 * Old logs didn't record the maximum zh_claim_lr_seq. 267 */ 268 if (!(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) 269 claim_lr_seq = UINT64_MAX; 270 271 /* 272 * Starting at the block pointed to by zh_log we read the log chain. 273 * For each block in the chain we strongly check that block to 274 * ensure its validity. We stop when an invalid block is found. 275 * For each block pointer in the chain we call parse_blk_func(). 276 * For each record in each valid block we call parse_lr_func(). 277 * If the log has been claimed, stop if we encounter a sequence 278 * number greater than the highest claimed sequence number. 279 */ 280 lrbuf = zio_buf_alloc(SPA_MAXBLOCKSIZE); 281 zil_bp_tree_init(zilog); 282 283 for (blk = zh->zh_log; !BP_IS_HOLE(&blk); blk = next_blk) { 284 zil_trailer_t *ztp = 285 (zil_trailer_t *)(lrbuf + BP_GET_LSIZE(&blk)) - 1; 286 uint64_t blk_seq = blk.blk_cksum.zc_word[ZIL_ZC_SEQ]; 287 int reclen; 288 289 if (blk_seq > claim_blk_seq) 290 break; 291 if ((error = parse_blk_func(zilog, &blk, arg, txg)) != 0) 292 break; 293 ASSERT(max_blk_seq < blk_seq); 294 max_blk_seq = blk_seq; 295 blk_count++; 296 297 if (max_lr_seq == claim_lr_seq && max_blk_seq == claim_blk_seq) 298 break; 299 300 error = zil_read_log_block(zilog, &blk, &next_blk, lrbuf); 301 if (error) 302 break; 303 304 for (lrp = lrbuf; lrp < lrbuf + ztp->zit_nused; lrp += reclen) { 305 lr_t *lr = (lr_t *)lrp; 306 reclen = lr->lrc_reclen; 307 ASSERT3U(reclen, >=, sizeof (lr_t)); 308 if (lr->lrc_seq > claim_lr_seq) 309 goto done; 310 if ((error = parse_lr_func(zilog, lr, arg, txg)) != 0) 311 goto done; 312 ASSERT(max_lr_seq < lr->lrc_seq); 313 max_lr_seq = lr->lrc_seq; 314 lr_count++; 315 } 316 } 317 done: 318 zilog->zl_parse_error = error; 319 zilog->zl_parse_blk_seq = max_blk_seq; 320 zilog->zl_parse_lr_seq = max_lr_seq; 321 zilog->zl_parse_blk_count = blk_count; 322 zilog->zl_parse_lr_count = lr_count; 323 324 ASSERT(!claimed || !(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID) || 325 (max_blk_seq == claim_blk_seq && max_lr_seq == claim_lr_seq)); 326 327 zil_bp_tree_fini(zilog); 328 zio_buf_free(lrbuf, SPA_MAXBLOCKSIZE); 329 330 return (error); 331 } 332 333 static int 334 zil_claim_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t first_txg) 335 { 336 /* 337 * Claim log block if not already committed and not already claimed. 338 * If tx == NULL, just verify that the block is claimable. 339 */ 340 if (bp->blk_birth < first_txg || zil_bp_tree_add(zilog, bp) != 0) 341 return (0); 342 343 return (zio_wait(zio_claim(NULL, zilog->zl_spa, 344 tx == NULL ? 0 : first_txg, bp, spa_claim_notify, NULL, 345 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB))); 346 } 347 348 static int 349 zil_claim_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t first_txg) 350 { 351 lr_write_t *lr = (lr_write_t *)lrc; 352 int error; 353 354 if (lrc->lrc_txtype != TX_WRITE) 355 return (0); 356 357 /* 358 * If the block is not readable, don't claim it. This can happen 359 * in normal operation when a log block is written to disk before 360 * some of the dmu_sync() blocks it points to. In this case, the 361 * transaction cannot have been committed to anyone (we would have 362 * waited for all writes to be stable first), so it is semantically 363 * correct to declare this the end of the log. 364 */ 365 if (lr->lr_blkptr.blk_birth >= first_txg && 366 (error = zil_read_log_data(zilog, lr, NULL)) != 0) 367 return (error); 368 369 return (zil_claim_log_block(zilog, &lr->lr_blkptr, tx, first_txg)); 370 } 371 372 /* ARGSUSED */ 373 static int 374 zil_free_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t claim_txg) 375 { 376 zio_free_zil(zilog->zl_spa, dmu_tx_get_txg(tx), bp); 377 378 return (0); 379 } 380 381 static int 382 zil_free_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t claim_txg) 383 { 384 lr_write_t *lr = (lr_write_t *)lrc; 385 blkptr_t *bp = &lr->lr_blkptr; 386 387 /* 388 * If we previously claimed it, we need to free it. 389 */ 390 if (claim_txg != 0 && lrc->lrc_txtype == TX_WRITE && 391 bp->blk_birth >= claim_txg && zil_bp_tree_add(zilog, bp) == 0) 392 zio_free(zilog->zl_spa, dmu_tx_get_txg(tx), bp); 393 394 return (0); 395 } 396 397 /* 398 * Create an on-disk intent log. 399 */ 400 static void 401 zil_create(zilog_t *zilog) 402 { 403 const zil_header_t *zh = zilog->zl_header; 404 lwb_t *lwb; 405 uint64_t txg = 0; 406 dmu_tx_t *tx = NULL; 407 blkptr_t blk; 408 int error = 0; 409 410 /* 411 * Wait for any previous destroy to complete. 412 */ 413 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 414 415 ASSERT(zh->zh_claim_txg == 0); 416 ASSERT(zh->zh_replay_seq == 0); 417 418 blk = zh->zh_log; 419 420 /* 421 * If we don't already have an initial log block or we have one 422 * but it's the wrong endianness then allocate one. 423 */ 424 if (BP_IS_HOLE(&blk) || BP_SHOULD_BYTESWAP(&blk)) { 425 tx = dmu_tx_create(zilog->zl_os); 426 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 427 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 428 txg = dmu_tx_get_txg(tx); 429 430 if (!BP_IS_HOLE(&blk)) { 431 zio_free_zil(zilog->zl_spa, txg, &blk); 432 BP_ZERO(&blk); 433 } 434 435 error = zio_alloc_zil(zilog->zl_spa, txg, &blk, NULL, 436 ZIL_MIN_BLKSZ, zilog->zl_logbias == ZFS_LOGBIAS_LATENCY); 437 438 if (error == 0) 439 zil_init_log_chain(zilog, &blk); 440 } 441 442 /* 443 * Allocate a log write buffer (lwb) for the first log block. 444 */ 445 if (error == 0) { 446 lwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP); 447 lwb->lwb_zilog = zilog; 448 lwb->lwb_blk = blk; 449 lwb->lwb_nused = 0; 450 lwb->lwb_sz = BP_GET_LSIZE(&lwb->lwb_blk); 451 lwb->lwb_buf = zio_buf_alloc(lwb->lwb_sz); 452 lwb->lwb_max_txg = txg; 453 lwb->lwb_zio = NULL; 454 lwb->lwb_tx = NULL; 455 456 mutex_enter(&zilog->zl_lock); 457 list_insert_tail(&zilog->zl_lwb_list, lwb); 458 mutex_exit(&zilog->zl_lock); 459 } 460 461 /* 462 * If we just allocated the first log block, commit our transaction 463 * and wait for zil_sync() to stuff the block poiner into zh_log. 464 * (zh is part of the MOS, so we cannot modify it in open context.) 465 */ 466 if (tx != NULL) { 467 dmu_tx_commit(tx); 468 txg_wait_synced(zilog->zl_dmu_pool, txg); 469 } 470 471 ASSERT(bcmp(&blk, &zh->zh_log, sizeof (blk)) == 0); 472 } 473 474 /* 475 * In one tx, free all log blocks and clear the log header. 476 * If keep_first is set, then we're replaying a log with no content. 477 * We want to keep the first block, however, so that the first 478 * synchronous transaction doesn't require a txg_wait_synced() 479 * in zil_create(). We don't need to txg_wait_synced() here either 480 * when keep_first is set, because both zil_create() and zil_destroy() 481 * will wait for any in-progress destroys to complete. 482 */ 483 void 484 zil_destroy(zilog_t *zilog, boolean_t keep_first) 485 { 486 const zil_header_t *zh = zilog->zl_header; 487 lwb_t *lwb; 488 dmu_tx_t *tx; 489 uint64_t txg; 490 491 /* 492 * Wait for any previous destroy to complete. 493 */ 494 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 495 496 zilog->zl_old_header = *zh; /* debugging aid */ 497 498 if (BP_IS_HOLE(&zh->zh_log)) 499 return; 500 501 tx = dmu_tx_create(zilog->zl_os); 502 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 503 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 504 txg = dmu_tx_get_txg(tx); 505 506 mutex_enter(&zilog->zl_lock); 507 508 ASSERT3U(zilog->zl_destroy_txg, <, txg); 509 zilog->zl_destroy_txg = txg; 510 zilog->zl_keep_first = keep_first; 511 512 if (!list_is_empty(&zilog->zl_lwb_list)) { 513 ASSERT(zh->zh_claim_txg == 0); 514 ASSERT(!keep_first); 515 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { 516 list_remove(&zilog->zl_lwb_list, lwb); 517 if (lwb->lwb_buf != NULL) 518 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 519 zio_free_zil(zilog->zl_spa, txg, &lwb->lwb_blk); 520 kmem_cache_free(zil_lwb_cache, lwb); 521 } 522 } else if (!keep_first) { 523 (void) zil_parse(zilog, zil_free_log_block, 524 zil_free_log_record, tx, zh->zh_claim_txg); 525 } 526 mutex_exit(&zilog->zl_lock); 527 528 dmu_tx_commit(tx); 529 } 530 531 int 532 zil_claim(char *osname, void *txarg) 533 { 534 dmu_tx_t *tx = txarg; 535 uint64_t first_txg = dmu_tx_get_txg(tx); 536 zilog_t *zilog; 537 zil_header_t *zh; 538 objset_t *os; 539 int error; 540 541 error = dmu_objset_hold(osname, FTAG, &os); 542 if (error) { 543 cmn_err(CE_WARN, "can't open objset for %s", osname); 544 return (0); 545 } 546 547 zilog = dmu_objset_zil(os); 548 zh = zil_header_in_syncing_context(zilog); 549 550 if (spa_get_log_state(zilog->zl_spa) == SPA_LOG_CLEAR) { 551 if (!BP_IS_HOLE(&zh->zh_log)) 552 zio_free_zil(zilog->zl_spa, first_txg, &zh->zh_log); 553 BP_ZERO(&zh->zh_log); 554 dsl_dataset_dirty(dmu_objset_ds(os), tx); 555 dmu_objset_rele(os, FTAG); 556 return (0); 557 } 558 559 /* 560 * Claim all log blocks if we haven't already done so, and remember 561 * the highest claimed sequence number. This ensures that if we can 562 * read only part of the log now (e.g. due to a missing device), 563 * but we can read the entire log later, we will not try to replay 564 * or destroy beyond the last block we successfully claimed. 565 */ 566 ASSERT3U(zh->zh_claim_txg, <=, first_txg); 567 if (zh->zh_claim_txg == 0 && !BP_IS_HOLE(&zh->zh_log)) { 568 (void) zil_parse(zilog, zil_claim_log_block, 569 zil_claim_log_record, tx, first_txg); 570 zh->zh_claim_txg = first_txg; 571 zh->zh_claim_blk_seq = zilog->zl_parse_blk_seq; 572 zh->zh_claim_lr_seq = zilog->zl_parse_lr_seq; 573 if (zilog->zl_parse_lr_count || zilog->zl_parse_blk_count > 1) 574 zh->zh_flags |= ZIL_REPLAY_NEEDED; 575 zh->zh_flags |= ZIL_CLAIM_LR_SEQ_VALID; 576 dsl_dataset_dirty(dmu_objset_ds(os), tx); 577 } 578 579 ASSERT3U(first_txg, ==, (spa_last_synced_txg(zilog->zl_spa) + 1)); 580 dmu_objset_rele(os, FTAG); 581 return (0); 582 } 583 584 /* 585 * Check the log by walking the log chain. 586 * Checksum errors are ok as they indicate the end of the chain. 587 * Any other error (no device or read failure) returns an error. 588 */ 589 int 590 zil_check_log_chain(char *osname, void *tx) 591 { 592 zilog_t *zilog; 593 objset_t *os; 594 int error; 595 596 ASSERT(tx == NULL); 597 598 error = dmu_objset_hold(osname, FTAG, &os); 599 if (error) { 600 cmn_err(CE_WARN, "can't open objset for %s", osname); 601 return (0); 602 } 603 604 zilog = dmu_objset_zil(os); 605 606 /* 607 * Because tx == NULL, zil_claim_log_block() will not actually claim 608 * any blocks, but just determine whether it is possible to do so. 609 * In addition to checking the log chain, zil_claim_log_block() 610 * will invoke zio_claim() with a done func of spa_claim_notify(), 611 * which will update spa_max_claim_txg. See spa_load() for details. 612 */ 613 error = zil_parse(zilog, zil_claim_log_block, zil_claim_log_record, tx, 614 zilog->zl_header->zh_claim_txg ? -1ULL : spa_first_txg(os->os_spa)); 615 616 dmu_objset_rele(os, FTAG); 617 618 return ((error == ECKSUM || error == ENOENT) ? 0 : error); 619 } 620 621 static int 622 zil_vdev_compare(const void *x1, const void *x2) 623 { 624 uint64_t v1 = ((zil_vdev_node_t *)x1)->zv_vdev; 625 uint64_t v2 = ((zil_vdev_node_t *)x2)->zv_vdev; 626 627 if (v1 < v2) 628 return (-1); 629 if (v1 > v2) 630 return (1); 631 632 return (0); 633 } 634 635 void 636 zil_add_block(zilog_t *zilog, const blkptr_t *bp) 637 { 638 avl_tree_t *t = &zilog->zl_vdev_tree; 639 avl_index_t where; 640 zil_vdev_node_t *zv, zvsearch; 641 int ndvas = BP_GET_NDVAS(bp); 642 int i; 643 644 if (zfs_nocacheflush) 645 return; 646 647 ASSERT(zilog->zl_writer); 648 649 /* 650 * Even though we're zl_writer, we still need a lock because the 651 * zl_get_data() callbacks may have dmu_sync() done callbacks 652 * that will run concurrently. 653 */ 654 mutex_enter(&zilog->zl_vdev_lock); 655 for (i = 0; i < ndvas; i++) { 656 zvsearch.zv_vdev = DVA_GET_VDEV(&bp->blk_dva[i]); 657 if (avl_find(t, &zvsearch, &where) == NULL) { 658 zv = kmem_alloc(sizeof (*zv), KM_SLEEP); 659 zv->zv_vdev = zvsearch.zv_vdev; 660 avl_insert(t, zv, where); 661 } 662 } 663 mutex_exit(&zilog->zl_vdev_lock); 664 } 665 666 void 667 zil_flush_vdevs(zilog_t *zilog) 668 { 669 spa_t *spa = zilog->zl_spa; 670 avl_tree_t *t = &zilog->zl_vdev_tree; 671 void *cookie = NULL; 672 zil_vdev_node_t *zv; 673 zio_t *zio; 674 675 ASSERT(zilog->zl_writer); 676 677 /* 678 * We don't need zl_vdev_lock here because we're the zl_writer, 679 * and all zl_get_data() callbacks are done. 680 */ 681 if (avl_numnodes(t) == 0) 682 return; 683 684 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER); 685 686 zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL); 687 688 while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) { 689 vdev_t *vd = vdev_lookup_top(spa, zv->zv_vdev); 690 if (vd != NULL) 691 zio_flush(zio, vd); 692 kmem_free(zv, sizeof (*zv)); 693 } 694 695 /* 696 * Wait for all the flushes to complete. Not all devices actually 697 * support the DKIOCFLUSHWRITECACHE ioctl, so it's OK if it fails. 698 */ 699 (void) zio_wait(zio); 700 701 spa_config_exit(spa, SCL_STATE, FTAG); 702 } 703 704 /* 705 * Function called when a log block write completes 706 */ 707 static void 708 zil_lwb_write_done(zio_t *zio) 709 { 710 lwb_t *lwb = zio->io_private; 711 zilog_t *zilog = lwb->lwb_zilog; 712 dmu_tx_t *tx = lwb->lwb_tx; 713 714 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 715 ASSERT(BP_GET_CHECKSUM(zio->io_bp) == ZIO_CHECKSUM_ZILOG); 716 ASSERT(BP_GET_TYPE(zio->io_bp) == DMU_OT_INTENT_LOG); 717 ASSERT(BP_GET_LEVEL(zio->io_bp) == 0); 718 ASSERT(BP_GET_BYTEORDER(zio->io_bp) == ZFS_HOST_BYTEORDER); 719 ASSERT(!BP_IS_GANG(zio->io_bp)); 720 ASSERT(!BP_IS_HOLE(zio->io_bp)); 721 ASSERT(zio->io_bp->blk_fill == 0); 722 723 /* 724 * Ensure the lwb buffer pointer is cleared before releasing 725 * the txg. If we have had an allocation failure and 726 * the txg is waiting to sync then we want want zil_sync() 727 * to remove the lwb so that it's not picked up as the next new 728 * one in zil_commit_writer(). zil_sync() will only remove 729 * the lwb if lwb_buf is null. 730 */ 731 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 732 mutex_enter(&zilog->zl_lock); 733 lwb->lwb_buf = NULL; 734 lwb->lwb_tx = NULL; 735 mutex_exit(&zilog->zl_lock); 736 737 /* 738 * Now that we've written this log block, we have a stable pointer 739 * to the next block in the chain, so it's OK to let the txg in 740 * which we allocated the next block sync. 741 */ 742 dmu_tx_commit(tx); 743 } 744 745 /* 746 * Initialize the io for a log block. 747 */ 748 static void 749 zil_lwb_write_init(zilog_t *zilog, lwb_t *lwb) 750 { 751 zbookmark_t zb; 752 753 SET_BOOKMARK(&zb, lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_OBJSET], 754 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, 755 lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_SEQ]); 756 757 if (zilog->zl_root_zio == NULL) { 758 zilog->zl_root_zio = zio_root(zilog->zl_spa, NULL, NULL, 759 ZIO_FLAG_CANFAIL); 760 } 761 if (lwb->lwb_zio == NULL) { 762 lwb->lwb_zio = zio_rewrite(zilog->zl_root_zio, zilog->zl_spa, 763 0, &lwb->lwb_blk, lwb->lwb_buf, lwb->lwb_sz, 764 zil_lwb_write_done, lwb, ZIO_PRIORITY_LOG_WRITE, 765 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE, &zb); 766 } 767 } 768 769 /* 770 * Use the slog as long as the logbias is 'latency' and the current commit size 771 * is less than the limit or the total list size is less than 2X the limit. 772 * Limit checking is disabled by setting zil_slog_limit to UINT64_MAX. 773 */ 774 uint64_t zil_slog_limit = 1024 * 1024; 775 #define USE_SLOG(zilog) (((zilog)->zl_logbias == ZFS_LOGBIAS_LATENCY) && \ 776 (((zilog)->zl_cur_used < zil_slog_limit) || \ 777 ((zilog)->zl_itx_list_sz < (zil_slog_limit << 1)))) 778 779 /* 780 * Start a log block write and advance to the next log block. 781 * Calls are serialized. 782 */ 783 static lwb_t * 784 zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb) 785 { 786 lwb_t *nlwb; 787 zil_trailer_t *ztp = (zil_trailer_t *)(lwb->lwb_buf + lwb->lwb_sz) - 1; 788 spa_t *spa = zilog->zl_spa; 789 blkptr_t *bp = &ztp->zit_next_blk; 790 dmu_tx_t *tx; 791 uint64_t txg; 792 uint64_t zil_blksz; 793 int error; 794 795 ASSERT(lwb->lwb_nused <= ZIL_BLK_DATA_SZ(lwb)); 796 797 /* 798 * Allocate the next block and save its address in this block 799 * before writing it in order to establish the log chain. 800 * Note that if the allocation of nlwb synced before we wrote 801 * the block that points at it (lwb), we'd leak it if we crashed. 802 * Therefore, we don't do dmu_tx_commit() until zil_lwb_write_done(). 803 * We dirty the dataset to ensure that zil_sync() will be called 804 * to clean up in the event of allocation failure or I/O failure. 805 */ 806 tx = dmu_tx_create(zilog->zl_os); 807 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 808 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 809 txg = dmu_tx_get_txg(tx); 810 811 lwb->lwb_tx = tx; 812 813 /* 814 * Pick a ZIL blocksize. We request a size that is the 815 * maximum of the previous used size, the current used size and 816 * the amount waiting in the queue. 817 */ 818 zil_blksz = MAX(zilog->zl_prev_used, 819 zilog->zl_cur_used + sizeof (*ztp)); 820 zil_blksz = MAX(zil_blksz, zilog->zl_itx_list_sz + sizeof (*ztp)); 821 zil_blksz = P2ROUNDUP_TYPED(zil_blksz, ZIL_MIN_BLKSZ, uint64_t); 822 if (zil_blksz > ZIL_MAX_BLKSZ) 823 zil_blksz = ZIL_MAX_BLKSZ; 824 825 BP_ZERO(bp); 826 /* pass the old blkptr in order to spread log blocks across devs */ 827 error = zio_alloc_zil(spa, txg, bp, &lwb->lwb_blk, zil_blksz, 828 USE_SLOG(zilog)); 829 if (error) { 830 /* 831 * Since we've just experienced an allocation failure, 832 * terminate the current lwb and send it on its way. 833 */ 834 ztp->zit_pad = 0; 835 ztp->zit_nused = lwb->lwb_nused; 836 ztp->zit_bt.zbt_cksum = lwb->lwb_blk.blk_cksum; 837 zio_nowait(lwb->lwb_zio); 838 839 /* 840 * By returning NULL the caller will call tx_wait_synced() 841 */ 842 return (NULL); 843 } 844 845 ASSERT3U(bp->blk_birth, ==, txg); 846 ztp->zit_pad = 0; 847 ztp->zit_nused = lwb->lwb_nused; 848 ztp->zit_bt.zbt_cksum = lwb->lwb_blk.blk_cksum; 849 bp->blk_cksum = lwb->lwb_blk.blk_cksum; 850 bp->blk_cksum.zc_word[ZIL_ZC_SEQ]++; 851 852 /* 853 * Allocate a new log write buffer (lwb). 854 */ 855 nlwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP); 856 nlwb->lwb_zilog = zilog; 857 nlwb->lwb_blk = *bp; 858 nlwb->lwb_nused = 0; 859 nlwb->lwb_sz = BP_GET_LSIZE(&nlwb->lwb_blk); 860 nlwb->lwb_buf = zio_buf_alloc(nlwb->lwb_sz); 861 nlwb->lwb_max_txg = txg; 862 nlwb->lwb_zio = NULL; 863 nlwb->lwb_tx = NULL; 864 865 /* 866 * Put new lwb at the end of the log chain 867 */ 868 mutex_enter(&zilog->zl_lock); 869 list_insert_tail(&zilog->zl_lwb_list, nlwb); 870 mutex_exit(&zilog->zl_lock); 871 872 /* Record the block for later vdev flushing */ 873 zil_add_block(zilog, &lwb->lwb_blk); 874 875 /* 876 * kick off the write for the old log block 877 */ 878 ASSERT(lwb->lwb_zio); 879 zio_nowait(lwb->lwb_zio); 880 881 return (nlwb); 882 } 883 884 static lwb_t * 885 zil_lwb_commit(zilog_t *zilog, itx_t *itx, lwb_t *lwb) 886 { 887 lr_t *lrc = &itx->itx_lr; /* common log record */ 888 lr_write_t *lrw = (lr_write_t *)lrc; 889 char *lr_buf; 890 uint64_t txg = lrc->lrc_txg; 891 uint64_t reclen = lrc->lrc_reclen; 892 uint64_t dlen = 0; 893 894 if (lwb == NULL) 895 return (NULL); 896 897 ASSERT(lwb->lwb_buf != NULL); 898 899 if (lrc->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY) 900 dlen = P2ROUNDUP_TYPED( 901 lrw->lr_length, sizeof (uint64_t), uint64_t); 902 903 zilog->zl_cur_used += (reclen + dlen); 904 905 zil_lwb_write_init(zilog, lwb); 906 907 /* 908 * If this record won't fit in the current log block, start a new one. 909 */ 910 if (lwb->lwb_nused + reclen + dlen > ZIL_BLK_DATA_SZ(lwb)) { 911 lwb = zil_lwb_write_start(zilog, lwb); 912 if (lwb == NULL) 913 return (NULL); 914 zil_lwb_write_init(zilog, lwb); 915 ASSERT(lwb->lwb_nused == 0); 916 if (reclen + dlen > ZIL_BLK_DATA_SZ(lwb)) { 917 txg_wait_synced(zilog->zl_dmu_pool, txg); 918 return (lwb); 919 } 920 } 921 922 lr_buf = lwb->lwb_buf + lwb->lwb_nused; 923 bcopy(lrc, lr_buf, reclen); 924 lrc = (lr_t *)lr_buf; 925 lrw = (lr_write_t *)lrc; 926 927 /* 928 * If it's a write, fetch the data or get its blkptr as appropriate. 929 */ 930 if (lrc->lrc_txtype == TX_WRITE) { 931 if (txg > spa_freeze_txg(zilog->zl_spa)) 932 txg_wait_synced(zilog->zl_dmu_pool, txg); 933 if (itx->itx_wr_state != WR_COPIED) { 934 char *dbuf; 935 int error; 936 937 if (dlen) { 938 ASSERT(itx->itx_wr_state == WR_NEED_COPY); 939 dbuf = lr_buf + reclen; 940 lrw->lr_common.lrc_reclen += dlen; 941 } else { 942 ASSERT(itx->itx_wr_state == WR_INDIRECT); 943 dbuf = NULL; 944 } 945 error = zilog->zl_get_data( 946 itx->itx_private, lrw, dbuf, lwb->lwb_zio); 947 if (error == EIO) { 948 txg_wait_synced(zilog->zl_dmu_pool, txg); 949 return (lwb); 950 } 951 if (error) { 952 ASSERT(error == ENOENT || error == EEXIST || 953 error == EALREADY); 954 return (lwb); 955 } 956 } 957 } 958 959 /* 960 * We're actually making an entry, so update lrc_seq to be the 961 * log record sequence number. Note that this is generally not 962 * equal to the itx sequence number because not all transactions 963 * are synchronous, and sometimes spa_sync() gets there first. 964 */ 965 lrc->lrc_seq = ++zilog->zl_lr_seq; /* we are single threaded */ 966 lwb->lwb_nused += reclen + dlen; 967 lwb->lwb_max_txg = MAX(lwb->lwb_max_txg, txg); 968 ASSERT3U(lwb->lwb_nused, <=, ZIL_BLK_DATA_SZ(lwb)); 969 ASSERT3U(P2PHASE(lwb->lwb_nused, sizeof (uint64_t)), ==, 0); 970 971 return (lwb); 972 } 973 974 itx_t * 975 zil_itx_create(uint64_t txtype, size_t lrsize) 976 { 977 itx_t *itx; 978 979 lrsize = P2ROUNDUP_TYPED(lrsize, sizeof (uint64_t), size_t); 980 981 itx = kmem_alloc(offsetof(itx_t, itx_lr) + lrsize, KM_SLEEP); 982 itx->itx_lr.lrc_txtype = txtype; 983 itx->itx_lr.lrc_reclen = lrsize; 984 itx->itx_sod = lrsize; /* if write & WR_NEED_COPY will be increased */ 985 itx->itx_lr.lrc_seq = 0; /* defensive */ 986 987 return (itx); 988 } 989 990 void 991 zil_itx_destroy(itx_t *itx) 992 { 993 kmem_free(itx, offsetof(itx_t, itx_lr) + itx->itx_lr.lrc_reclen); 994 } 995 996 uint64_t 997 zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx) 998 { 999 uint64_t seq; 1000 1001 ASSERT(itx->itx_lr.lrc_seq == 0); 1002 ASSERT(!zilog->zl_replay); 1003 1004 mutex_enter(&zilog->zl_lock); 1005 list_insert_tail(&zilog->zl_itx_list, itx); 1006 zilog->zl_itx_list_sz += itx->itx_sod; 1007 itx->itx_lr.lrc_txg = dmu_tx_get_txg(tx); 1008 itx->itx_lr.lrc_seq = seq = ++zilog->zl_itx_seq; 1009 mutex_exit(&zilog->zl_lock); 1010 1011 return (seq); 1012 } 1013 1014 /* 1015 * Free up all in-memory intent log transactions that have now been synced. 1016 */ 1017 static void 1018 zil_itx_clean(zilog_t *zilog) 1019 { 1020 uint64_t synced_txg = spa_last_synced_txg(zilog->zl_spa); 1021 uint64_t freeze_txg = spa_freeze_txg(zilog->zl_spa); 1022 list_t clean_list; 1023 itx_t *itx; 1024 1025 list_create(&clean_list, sizeof (itx_t), offsetof(itx_t, itx_node)); 1026 1027 mutex_enter(&zilog->zl_lock); 1028 /* wait for a log writer to finish walking list */ 1029 while (zilog->zl_writer) { 1030 cv_wait(&zilog->zl_cv_writer, &zilog->zl_lock); 1031 } 1032 1033 /* 1034 * Move the sync'd log transactions to a separate list so we can call 1035 * kmem_free without holding the zl_lock. 1036 * 1037 * There is no need to set zl_writer as we don't drop zl_lock here 1038 */ 1039 while ((itx = list_head(&zilog->zl_itx_list)) != NULL && 1040 itx->itx_lr.lrc_txg <= MIN(synced_txg, freeze_txg)) { 1041 list_remove(&zilog->zl_itx_list, itx); 1042 zilog->zl_itx_list_sz -= itx->itx_sod; 1043 list_insert_tail(&clean_list, itx); 1044 } 1045 cv_broadcast(&zilog->zl_cv_writer); 1046 mutex_exit(&zilog->zl_lock); 1047 1048 /* destroy sync'd log transactions */ 1049 while ((itx = list_head(&clean_list)) != NULL) { 1050 list_remove(&clean_list, itx); 1051 zil_itx_destroy(itx); 1052 } 1053 list_destroy(&clean_list); 1054 } 1055 1056 /* 1057 * If there are any in-memory intent log transactions which have now been 1058 * synced then start up a taskq to free them. 1059 */ 1060 void 1061 zil_clean(zilog_t *zilog) 1062 { 1063 itx_t *itx; 1064 1065 mutex_enter(&zilog->zl_lock); 1066 itx = list_head(&zilog->zl_itx_list); 1067 if ((itx != NULL) && 1068 (itx->itx_lr.lrc_txg <= spa_last_synced_txg(zilog->zl_spa))) { 1069 (void) taskq_dispatch(zilog->zl_clean_taskq, 1070 (task_func_t *)zil_itx_clean, zilog, TQ_NOSLEEP); 1071 } 1072 mutex_exit(&zilog->zl_lock); 1073 } 1074 1075 static void 1076 zil_commit_writer(zilog_t *zilog, uint64_t seq, uint64_t foid) 1077 { 1078 uint64_t txg; 1079 uint64_t commit_seq = 0; 1080 itx_t *itx, *itx_next; 1081 lwb_t *lwb; 1082 spa_t *spa; 1083 int error = 0; 1084 1085 zilog->zl_writer = B_TRUE; 1086 ASSERT(zilog->zl_root_zio == NULL); 1087 spa = zilog->zl_spa; 1088 1089 if (zilog->zl_suspend) { 1090 lwb = NULL; 1091 } else { 1092 lwb = list_tail(&zilog->zl_lwb_list); 1093 if (lwb == NULL) { 1094 /* 1095 * Return if there's nothing to flush before we 1096 * dirty the fs by calling zil_create() 1097 */ 1098 if (list_is_empty(&zilog->zl_itx_list)) { 1099 zilog->zl_writer = B_FALSE; 1100 return; 1101 } 1102 mutex_exit(&zilog->zl_lock); 1103 zil_create(zilog); 1104 mutex_enter(&zilog->zl_lock); 1105 lwb = list_tail(&zilog->zl_lwb_list); 1106 } 1107 } 1108 1109 /* Loop through in-memory log transactions filling log blocks. */ 1110 DTRACE_PROBE1(zil__cw1, zilog_t *, zilog); 1111 1112 for (itx = list_head(&zilog->zl_itx_list); itx; itx = itx_next) { 1113 /* 1114 * Save the next pointer. Even though we drop zl_lock below, 1115 * all threads that can remove itx list entries (other writers 1116 * and zil_itx_clean()) can't do so until they have zl_writer. 1117 */ 1118 itx_next = list_next(&zilog->zl_itx_list, itx); 1119 1120 /* 1121 * Determine whether to push this itx. 1122 * Push all transactions related to specified foid and 1123 * all other transactions except those that can be logged 1124 * out of order (TX_WRITE, TX_TRUNCATE, TX_SETATTR, TX_ACL) 1125 * for all other files. 1126 * 1127 * If foid == 0 (meaning "push all foids") or 1128 * itx->itx_sync is set (meaning O_[D]SYNC), push regardless. 1129 */ 1130 if (foid != 0 && !itx->itx_sync && 1131 TX_OOO(itx->itx_lr.lrc_txtype) && 1132 ((lr_ooo_t *)&itx->itx_lr)->lr_foid != foid) 1133 continue; /* skip this record */ 1134 1135 if ((itx->itx_lr.lrc_seq > seq) && 1136 ((lwb == NULL) || (lwb->lwb_nused == 0) || 1137 (lwb->lwb_nused + itx->itx_sod > ZIL_BLK_DATA_SZ(lwb)))) 1138 break; 1139 1140 list_remove(&zilog->zl_itx_list, itx); 1141 zilog->zl_itx_list_sz -= itx->itx_sod; 1142 1143 mutex_exit(&zilog->zl_lock); 1144 1145 txg = itx->itx_lr.lrc_txg; 1146 ASSERT(txg); 1147 1148 if (txg > spa_last_synced_txg(spa) || 1149 txg > spa_freeze_txg(spa)) 1150 lwb = zil_lwb_commit(zilog, itx, lwb); 1151 1152 zil_itx_destroy(itx); 1153 1154 mutex_enter(&zilog->zl_lock); 1155 } 1156 DTRACE_PROBE1(zil__cw2, zilog_t *, zilog); 1157 /* determine commit sequence number */ 1158 itx = list_head(&zilog->zl_itx_list); 1159 if (itx) 1160 commit_seq = itx->itx_lr.lrc_seq - 1; 1161 else 1162 commit_seq = zilog->zl_itx_seq; 1163 mutex_exit(&zilog->zl_lock); 1164 1165 /* write the last block out */ 1166 if (lwb != NULL && lwb->lwb_zio != NULL) 1167 lwb = zil_lwb_write_start(zilog, lwb); 1168 1169 zilog->zl_prev_used = zilog->zl_cur_used; 1170 zilog->zl_cur_used = 0; 1171 1172 /* 1173 * Wait if necessary for the log blocks to be on stable storage. 1174 */ 1175 if (zilog->zl_root_zio) { 1176 DTRACE_PROBE1(zil__cw3, zilog_t *, zilog); 1177 error = zio_wait(zilog->zl_root_zio); 1178 zilog->zl_root_zio = NULL; 1179 DTRACE_PROBE1(zil__cw4, zilog_t *, zilog); 1180 zil_flush_vdevs(zilog); 1181 } 1182 1183 if (error || lwb == NULL) 1184 txg_wait_synced(zilog->zl_dmu_pool, 0); 1185 1186 mutex_enter(&zilog->zl_lock); 1187 zilog->zl_writer = B_FALSE; 1188 1189 ASSERT3U(commit_seq, >=, zilog->zl_commit_seq); 1190 zilog->zl_commit_seq = commit_seq; 1191 1192 /* 1193 * Remember the highest committed log sequence number for ztest. 1194 * We only update this value when all the log writes succeeded, 1195 * because ztest wants to ASSERT that it got the whole log chain. 1196 */ 1197 if (error == 0 && lwb != NULL) 1198 zilog->zl_commit_lr_seq = zilog->zl_lr_seq; 1199 } 1200 1201 /* 1202 * Push zfs transactions to stable storage up to the supplied sequence number. 1203 * If foid is 0 push out all transactions, otherwise push only those 1204 * for that file or might have been used to create that file. 1205 */ 1206 void 1207 zil_commit(zilog_t *zilog, uint64_t seq, uint64_t foid) 1208 { 1209 if (zilog == NULL || seq == 0) 1210 return; 1211 1212 mutex_enter(&zilog->zl_lock); 1213 1214 seq = MIN(seq, zilog->zl_itx_seq); /* cap seq at largest itx seq */ 1215 1216 while (zilog->zl_writer) { 1217 cv_wait(&zilog->zl_cv_writer, &zilog->zl_lock); 1218 if (seq <= zilog->zl_commit_seq) { 1219 mutex_exit(&zilog->zl_lock); 1220 return; 1221 } 1222 } 1223 zil_commit_writer(zilog, seq, foid); /* drops zl_lock */ 1224 /* wake up others waiting on the commit */ 1225 cv_broadcast(&zilog->zl_cv_writer); 1226 mutex_exit(&zilog->zl_lock); 1227 } 1228 1229 /* 1230 * Report whether all transactions are committed. 1231 */ 1232 static boolean_t 1233 zil_is_committed(zilog_t *zilog) 1234 { 1235 lwb_t *lwb; 1236 boolean_t committed; 1237 1238 mutex_enter(&zilog->zl_lock); 1239 1240 while (zilog->zl_writer) 1241 cv_wait(&zilog->zl_cv_writer, &zilog->zl_lock); 1242 1243 if (!list_is_empty(&zilog->zl_itx_list)) 1244 committed = B_FALSE; /* unpushed transactions */ 1245 else if ((lwb = list_head(&zilog->zl_lwb_list)) == NULL) 1246 committed = B_TRUE; /* intent log never used */ 1247 else if (list_next(&zilog->zl_lwb_list, lwb) != NULL) 1248 committed = B_FALSE; /* zil_sync() not done yet */ 1249 else 1250 committed = B_TRUE; /* everything synced */ 1251 1252 mutex_exit(&zilog->zl_lock); 1253 return (committed); 1254 } 1255 1256 /* 1257 * Called in syncing context to free committed log blocks and update log header. 1258 */ 1259 void 1260 zil_sync(zilog_t *zilog, dmu_tx_t *tx) 1261 { 1262 zil_header_t *zh = zil_header_in_syncing_context(zilog); 1263 uint64_t txg = dmu_tx_get_txg(tx); 1264 spa_t *spa = zilog->zl_spa; 1265 uint64_t *replayed_seq = &zilog->zl_replayed_seq[txg & TXG_MASK]; 1266 lwb_t *lwb; 1267 1268 /* 1269 * We don't zero out zl_destroy_txg, so make sure we don't try 1270 * to destroy it twice. 1271 */ 1272 if (spa_sync_pass(spa) != 1) 1273 return; 1274 1275 mutex_enter(&zilog->zl_lock); 1276 1277 ASSERT(zilog->zl_stop_sync == 0); 1278 1279 if (*replayed_seq != 0) { 1280 ASSERT(zh->zh_replay_seq < *replayed_seq); 1281 zh->zh_replay_seq = *replayed_seq; 1282 *replayed_seq = 0; 1283 } 1284 1285 if (zilog->zl_destroy_txg == txg) { 1286 blkptr_t blk = zh->zh_log; 1287 1288 ASSERT(list_head(&zilog->zl_lwb_list) == NULL); 1289 1290 bzero(zh, sizeof (zil_header_t)); 1291 bzero(zilog->zl_replayed_seq, sizeof (zilog->zl_replayed_seq)); 1292 1293 if (zilog->zl_keep_first) { 1294 /* 1295 * If this block was part of log chain that couldn't 1296 * be claimed because a device was missing during 1297 * zil_claim(), but that device later returns, 1298 * then this block could erroneously appear valid. 1299 * To guard against this, assign a new GUID to the new 1300 * log chain so it doesn't matter what blk points to. 1301 */ 1302 zil_init_log_chain(zilog, &blk); 1303 zh->zh_log = blk; 1304 } 1305 } 1306 1307 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { 1308 zh->zh_log = lwb->lwb_blk; 1309 if (lwb->lwb_buf != NULL || lwb->lwb_max_txg > txg) 1310 break; 1311 list_remove(&zilog->zl_lwb_list, lwb); 1312 zio_free_zil(spa, txg, &lwb->lwb_blk); 1313 kmem_cache_free(zil_lwb_cache, lwb); 1314 1315 /* 1316 * If we don't have anything left in the lwb list then 1317 * we've had an allocation failure and we need to zero 1318 * out the zil_header blkptr so that we don't end 1319 * up freeing the same block twice. 1320 */ 1321 if (list_head(&zilog->zl_lwb_list) == NULL) 1322 BP_ZERO(&zh->zh_log); 1323 } 1324 mutex_exit(&zilog->zl_lock); 1325 } 1326 1327 void 1328 zil_init(void) 1329 { 1330 zil_lwb_cache = kmem_cache_create("zil_lwb_cache", 1331 sizeof (struct lwb), 0, NULL, NULL, NULL, NULL, NULL, 0); 1332 } 1333 1334 void 1335 zil_fini(void) 1336 { 1337 kmem_cache_destroy(zil_lwb_cache); 1338 } 1339 1340 void 1341 zil_set_logbias(zilog_t *zilog, uint64_t logbias) 1342 { 1343 zilog->zl_logbias = logbias; 1344 } 1345 1346 zilog_t * 1347 zil_alloc(objset_t *os, zil_header_t *zh_phys) 1348 { 1349 zilog_t *zilog; 1350 1351 zilog = kmem_zalloc(sizeof (zilog_t), KM_SLEEP); 1352 1353 zilog->zl_header = zh_phys; 1354 zilog->zl_os = os; 1355 zilog->zl_spa = dmu_objset_spa(os); 1356 zilog->zl_dmu_pool = dmu_objset_pool(os); 1357 zilog->zl_destroy_txg = TXG_INITIAL - 1; 1358 zilog->zl_logbias = dmu_objset_logbias(os); 1359 1360 mutex_init(&zilog->zl_lock, NULL, MUTEX_DEFAULT, NULL); 1361 1362 list_create(&zilog->zl_itx_list, sizeof (itx_t), 1363 offsetof(itx_t, itx_node)); 1364 1365 list_create(&zilog->zl_lwb_list, sizeof (lwb_t), 1366 offsetof(lwb_t, lwb_node)); 1367 1368 mutex_init(&zilog->zl_vdev_lock, NULL, MUTEX_DEFAULT, NULL); 1369 1370 avl_create(&zilog->zl_vdev_tree, zil_vdev_compare, 1371 sizeof (zil_vdev_node_t), offsetof(zil_vdev_node_t, zv_node)); 1372 1373 cv_init(&zilog->zl_cv_writer, NULL, CV_DEFAULT, NULL); 1374 cv_init(&zilog->zl_cv_suspend, NULL, CV_DEFAULT, NULL); 1375 1376 return (zilog); 1377 } 1378 1379 void 1380 zil_free(zilog_t *zilog) 1381 { 1382 lwb_t *lwb; 1383 1384 zilog->zl_stop_sync = 1; 1385 1386 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { 1387 list_remove(&zilog->zl_lwb_list, lwb); 1388 if (lwb->lwb_buf != NULL) 1389 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 1390 kmem_cache_free(zil_lwb_cache, lwb); 1391 } 1392 list_destroy(&zilog->zl_lwb_list); 1393 1394 avl_destroy(&zilog->zl_vdev_tree); 1395 mutex_destroy(&zilog->zl_vdev_lock); 1396 1397 ASSERT(list_head(&zilog->zl_itx_list) == NULL); 1398 list_destroy(&zilog->zl_itx_list); 1399 mutex_destroy(&zilog->zl_lock); 1400 1401 cv_destroy(&zilog->zl_cv_writer); 1402 cv_destroy(&zilog->zl_cv_suspend); 1403 1404 kmem_free(zilog, sizeof (zilog_t)); 1405 } 1406 1407 /* 1408 * Open an intent log. 1409 */ 1410 zilog_t * 1411 zil_open(objset_t *os, zil_get_data_t *get_data) 1412 { 1413 zilog_t *zilog = dmu_objset_zil(os); 1414 1415 zilog->zl_get_data = get_data; 1416 zilog->zl_clean_taskq = taskq_create("zil_clean", 1, minclsyspri, 1417 2, 2, TASKQ_PREPOPULATE); 1418 1419 return (zilog); 1420 } 1421 1422 /* 1423 * Close an intent log. 1424 */ 1425 void 1426 zil_close(zilog_t *zilog) 1427 { 1428 /* 1429 * If the log isn't already committed, mark the objset dirty 1430 * (so zil_sync() will be called) and wait for that txg to sync. 1431 */ 1432 if (!zil_is_committed(zilog)) { 1433 uint64_t txg; 1434 dmu_tx_t *tx = dmu_tx_create(zilog->zl_os); 1435 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 1436 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 1437 txg = dmu_tx_get_txg(tx); 1438 dmu_tx_commit(tx); 1439 txg_wait_synced(zilog->zl_dmu_pool, txg); 1440 } 1441 1442 taskq_destroy(zilog->zl_clean_taskq); 1443 zilog->zl_clean_taskq = NULL; 1444 zilog->zl_get_data = NULL; 1445 1446 zil_itx_clean(zilog); 1447 ASSERT(list_head(&zilog->zl_itx_list) == NULL); 1448 } 1449 1450 /* 1451 * Suspend an intent log. While in suspended mode, we still honor 1452 * synchronous semantics, but we rely on txg_wait_synced() to do it. 1453 * We suspend the log briefly when taking a snapshot so that the snapshot 1454 * contains all the data it's supposed to, and has an empty intent log. 1455 */ 1456 int 1457 zil_suspend(zilog_t *zilog) 1458 { 1459 const zil_header_t *zh = zilog->zl_header; 1460 1461 mutex_enter(&zilog->zl_lock); 1462 if (zh->zh_flags & ZIL_REPLAY_NEEDED) { /* unplayed log */ 1463 mutex_exit(&zilog->zl_lock); 1464 return (EBUSY); 1465 } 1466 if (zilog->zl_suspend++ != 0) { 1467 /* 1468 * Someone else already began a suspend. 1469 * Just wait for them to finish. 1470 */ 1471 while (zilog->zl_suspending) 1472 cv_wait(&zilog->zl_cv_suspend, &zilog->zl_lock); 1473 mutex_exit(&zilog->zl_lock); 1474 return (0); 1475 } 1476 zilog->zl_suspending = B_TRUE; 1477 mutex_exit(&zilog->zl_lock); 1478 1479 zil_commit(zilog, UINT64_MAX, 0); 1480 1481 /* 1482 * Wait for any in-flight log writes to complete. 1483 */ 1484 mutex_enter(&zilog->zl_lock); 1485 while (zilog->zl_writer) 1486 cv_wait(&zilog->zl_cv_writer, &zilog->zl_lock); 1487 mutex_exit(&zilog->zl_lock); 1488 1489 zil_destroy(zilog, B_FALSE); 1490 1491 mutex_enter(&zilog->zl_lock); 1492 zilog->zl_suspending = B_FALSE; 1493 cv_broadcast(&zilog->zl_cv_suspend); 1494 mutex_exit(&zilog->zl_lock); 1495 1496 return (0); 1497 } 1498 1499 void 1500 zil_resume(zilog_t *zilog) 1501 { 1502 mutex_enter(&zilog->zl_lock); 1503 ASSERT(zilog->zl_suspend != 0); 1504 zilog->zl_suspend--; 1505 mutex_exit(&zilog->zl_lock); 1506 } 1507 1508 typedef struct zil_replay_arg { 1509 zil_replay_func_t **zr_replay; 1510 void *zr_arg; 1511 boolean_t zr_byteswap; 1512 char *zr_lr; 1513 } zil_replay_arg_t; 1514 1515 static int 1516 zil_replay_error(zilog_t *zilog, lr_t *lr, int error) 1517 { 1518 char name[MAXNAMELEN]; 1519 1520 zilog->zl_replaying_seq--; /* didn't actually replay this one */ 1521 1522 dmu_objset_name(zilog->zl_os, name); 1523 1524 cmn_err(CE_WARN, "ZFS replay transaction error %d, " 1525 "dataset %s, seq 0x%llx, txtype %llu %s\n", error, name, 1526 (u_longlong_t)lr->lrc_seq, 1527 (u_longlong_t)(lr->lrc_txtype & ~TX_CI), 1528 (lr->lrc_txtype & TX_CI) ? "CI" : ""); 1529 1530 return (error); 1531 } 1532 1533 static int 1534 zil_replay_log_record(zilog_t *zilog, lr_t *lr, void *zra, uint64_t claim_txg) 1535 { 1536 zil_replay_arg_t *zr = zra; 1537 const zil_header_t *zh = zilog->zl_header; 1538 uint64_t reclen = lr->lrc_reclen; 1539 uint64_t txtype = lr->lrc_txtype; 1540 int error = 0; 1541 1542 zilog->zl_replaying_seq = lr->lrc_seq; 1543 1544 if (lr->lrc_seq <= zh->zh_replay_seq) /* already replayed */ 1545 return (0); 1546 1547 if (lr->lrc_txg < claim_txg) /* already committed */ 1548 return (0); 1549 1550 /* Strip case-insensitive bit, still present in log record */ 1551 txtype &= ~TX_CI; 1552 1553 if (txtype == 0 || txtype >= TX_MAX_TYPE) 1554 return (zil_replay_error(zilog, lr, EINVAL)); 1555 1556 /* 1557 * If this record type can be logged out of order, the object 1558 * (lr_foid) may no longer exist. That's legitimate, not an error. 1559 */ 1560 if (TX_OOO(txtype)) { 1561 error = dmu_object_info(zilog->zl_os, 1562 ((lr_ooo_t *)lr)->lr_foid, NULL); 1563 if (error == ENOENT || error == EEXIST) 1564 return (0); 1565 } 1566 1567 /* 1568 * Make a copy of the data so we can revise and extend it. 1569 */ 1570 bcopy(lr, zr->zr_lr, reclen); 1571 1572 /* 1573 * If this is a TX_WRITE with a blkptr, suck in the data. 1574 */ 1575 if (txtype == TX_WRITE && reclen == sizeof (lr_write_t)) { 1576 error = zil_read_log_data(zilog, (lr_write_t *)lr, 1577 zr->zr_lr + reclen); 1578 if (error) 1579 return (zil_replay_error(zilog, lr, error)); 1580 } 1581 1582 /* 1583 * The log block containing this lr may have been byteswapped 1584 * so that we can easily examine common fields like lrc_txtype. 1585 * However, the log is a mix of different record types, and only the 1586 * replay vectors know how to byteswap their records. Therefore, if 1587 * the lr was byteswapped, undo it before invoking the replay vector. 1588 */ 1589 if (zr->zr_byteswap) 1590 byteswap_uint64_array(zr->zr_lr, reclen); 1591 1592 /* 1593 * We must now do two things atomically: replay this log record, 1594 * and update the log header sequence number to reflect the fact that 1595 * we did so. At the end of each replay function the sequence number 1596 * is updated if we are in replay mode. 1597 */ 1598 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, zr->zr_byteswap); 1599 if (error) { 1600 /* 1601 * The DMU's dnode layer doesn't see removes until the txg 1602 * commits, so a subsequent claim can spuriously fail with 1603 * EEXIST. So if we receive any error we try syncing out 1604 * any removes then retry the transaction. Note that we 1605 * specify B_FALSE for byteswap now, so we don't do it twice. 1606 */ 1607 txg_wait_synced(spa_get_dsl(zilog->zl_spa), 0); 1608 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, B_FALSE); 1609 if (error) 1610 return (zil_replay_error(zilog, lr, error)); 1611 } 1612 return (0); 1613 } 1614 1615 /* ARGSUSED */ 1616 static int 1617 zil_incr_blks(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg) 1618 { 1619 zilog->zl_replay_blks++; 1620 1621 return (0); 1622 } 1623 1624 /* 1625 * If this dataset has a non-empty intent log, replay it and destroy it. 1626 */ 1627 void 1628 zil_replay(objset_t *os, void *arg, zil_replay_func_t *replay_func[TX_MAX_TYPE]) 1629 { 1630 zilog_t *zilog = dmu_objset_zil(os); 1631 const zil_header_t *zh = zilog->zl_header; 1632 zil_replay_arg_t zr; 1633 1634 if ((zh->zh_flags & ZIL_REPLAY_NEEDED) == 0) { 1635 zil_destroy(zilog, B_TRUE); 1636 return; 1637 } 1638 1639 zr.zr_replay = replay_func; 1640 zr.zr_arg = arg; 1641 zr.zr_byteswap = BP_SHOULD_BYTESWAP(&zh->zh_log); 1642 zr.zr_lr = kmem_alloc(2 * SPA_MAXBLOCKSIZE, KM_SLEEP); 1643 1644 /* 1645 * Wait for in-progress removes to sync before starting replay. 1646 */ 1647 txg_wait_synced(zilog->zl_dmu_pool, 0); 1648 1649 zilog->zl_replay = B_TRUE; 1650 zilog->zl_replay_time = lbolt; 1651 ASSERT(zilog->zl_replay_blks == 0); 1652 (void) zil_parse(zilog, zil_incr_blks, zil_replay_log_record, &zr, 1653 zh->zh_claim_txg); 1654 kmem_free(zr.zr_lr, 2 * SPA_MAXBLOCKSIZE); 1655 1656 zil_destroy(zilog, B_FALSE); 1657 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 1658 zilog->zl_replay = B_FALSE; 1659 } 1660 1661 boolean_t 1662 zil_replaying(zilog_t *zilog, dmu_tx_t *tx) 1663 { 1664 if (zilog == NULL) 1665 return (B_TRUE); 1666 1667 if (zilog->zl_replay) { 1668 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 1669 zilog->zl_replayed_seq[dmu_tx_get_txg(tx) & TXG_MASK] = 1670 zilog->zl_replaying_seq; 1671 return (B_TRUE); 1672 } 1673 1674 return (B_FALSE); 1675 } 1676 1677 /* ARGSUSED */ 1678 int 1679 zil_vdev_offline(char *osname, void *arg) 1680 { 1681 objset_t *os; 1682 zilog_t *zilog; 1683 int error; 1684 1685 error = dmu_objset_hold(osname, FTAG, &os); 1686 if (error) 1687 return (error); 1688 1689 zilog = dmu_objset_zil(os); 1690 if (zil_suspend(zilog) != 0) 1691 error = EEXIST; 1692 else 1693 zil_resume(zilog); 1694 dmu_objset_rele(os, FTAG); 1695 return (error); 1696 } 1697