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) 2013 by Delphix. All rights reserved. 24 */ 25 26 /* Portions Copyright 2010 Robert Milkowski */ 27 28 #include <sys/zfs_context.h> 29 #include <sys/spa.h> 30 #include <sys/dmu.h> 31 #include <sys/zap.h> 32 #include <sys/arc.h> 33 #include <sys/stat.h> 34 #include <sys/resource.h> 35 #include <sys/zil.h> 36 #include <sys/zil_impl.h> 37 #include <sys/dsl_dataset.h> 38 #include <sys/vdev_impl.h> 39 #include <sys/dmu_tx.h> 40 #include <sys/dsl_pool.h> 41 42 /* 43 * The zfs intent log (ZIL) saves transaction records of system calls 44 * that change the file system in memory with enough information 45 * to be able to replay them. These are stored in memory until 46 * either the DMU transaction group (txg) commits them to the stable pool 47 * and they can be discarded, or they are flushed to the stable log 48 * (also in the pool) due to a fsync, O_DSYNC or other synchronous 49 * requirement. In the event of a panic or power fail then those log 50 * records (transactions) are replayed. 51 * 52 * There is one ZIL per file system. Its on-disk (pool) format consists 53 * of 3 parts: 54 * 55 * - ZIL header 56 * - ZIL blocks 57 * - ZIL records 58 * 59 * A log record holds a system call transaction. Log blocks can 60 * hold many log records and the blocks are chained together. 61 * Each ZIL block contains a block pointer (blkptr_t) to the next 62 * ZIL block in the chain. The ZIL header points to the first 63 * block in the chain. Note there is not a fixed place in the pool 64 * to hold blocks. They are dynamically allocated and freed as 65 * needed from the blocks available. Figure X shows the ZIL structure: 66 */ 67 68 /* 69 * Disable intent logging replay. This global ZIL switch affects all pools. 70 */ 71 int zil_replay_disable = 0; 72 73 /* 74 * Tunable parameter for debugging or performance analysis. Setting 75 * zfs_nocacheflush will cause corruption on power loss if a volatile 76 * out-of-order write cache is enabled. 77 */ 78 boolean_t zfs_nocacheflush = B_FALSE; 79 80 static kmem_cache_t *zil_lwb_cache; 81 82 static void zil_async_to_sync(zilog_t *zilog, uint64_t foid); 83 84 #define LWB_EMPTY(lwb) ((BP_GET_LSIZE(&lwb->lwb_blk) - \ 85 sizeof (zil_chain_t)) == (lwb->lwb_sz - lwb->lwb_nused)) 86 87 88 /* 89 * ziltest is by and large an ugly hack, but very useful in 90 * checking replay without tedious work. 91 * When running ziltest we want to keep all itx's and so maintain 92 * a single list in the zl_itxg[] that uses a high txg: ZILTEST_TXG 93 * We subtract TXG_CONCURRENT_STATES to allow for common code. 94 */ 95 #define ZILTEST_TXG (UINT64_MAX - TXG_CONCURRENT_STATES) 96 97 static int 98 zil_bp_compare(const void *x1, const void *x2) 99 { 100 const dva_t *dva1 = &((zil_bp_node_t *)x1)->zn_dva; 101 const dva_t *dva2 = &((zil_bp_node_t *)x2)->zn_dva; 102 103 if (DVA_GET_VDEV(dva1) < DVA_GET_VDEV(dva2)) 104 return (-1); 105 if (DVA_GET_VDEV(dva1) > DVA_GET_VDEV(dva2)) 106 return (1); 107 108 if (DVA_GET_OFFSET(dva1) < DVA_GET_OFFSET(dva2)) 109 return (-1); 110 if (DVA_GET_OFFSET(dva1) > DVA_GET_OFFSET(dva2)) 111 return (1); 112 113 return (0); 114 } 115 116 static void 117 zil_bp_tree_init(zilog_t *zilog) 118 { 119 avl_create(&zilog->zl_bp_tree, zil_bp_compare, 120 sizeof (zil_bp_node_t), offsetof(zil_bp_node_t, zn_node)); 121 } 122 123 static void 124 zil_bp_tree_fini(zilog_t *zilog) 125 { 126 avl_tree_t *t = &zilog->zl_bp_tree; 127 zil_bp_node_t *zn; 128 void *cookie = NULL; 129 130 while ((zn = avl_destroy_nodes(t, &cookie)) != NULL) 131 kmem_free(zn, sizeof (zil_bp_node_t)); 132 133 avl_destroy(t); 134 } 135 136 int 137 zil_bp_tree_add(zilog_t *zilog, const blkptr_t *bp) 138 { 139 avl_tree_t *t = &zilog->zl_bp_tree; 140 const dva_t *dva; 141 zil_bp_node_t *zn; 142 avl_index_t where; 143 144 if (BP_IS_EMBEDDED(bp)) 145 return (0); 146 147 dva = BP_IDENTITY(bp); 148 149 if (avl_find(t, dva, &where) != NULL) 150 return (SET_ERROR(EEXIST)); 151 152 zn = kmem_alloc(sizeof (zil_bp_node_t), KM_SLEEP); 153 zn->zn_dva = *dva; 154 avl_insert(t, zn, where); 155 156 return (0); 157 } 158 159 static zil_header_t * 160 zil_header_in_syncing_context(zilog_t *zilog) 161 { 162 return ((zil_header_t *)zilog->zl_header); 163 } 164 165 static void 166 zil_init_log_chain(zilog_t *zilog, blkptr_t *bp) 167 { 168 zio_cksum_t *zc = &bp->blk_cksum; 169 170 zc->zc_word[ZIL_ZC_GUID_0] = spa_get_random(-1ULL); 171 zc->zc_word[ZIL_ZC_GUID_1] = spa_get_random(-1ULL); 172 zc->zc_word[ZIL_ZC_OBJSET] = dmu_objset_id(zilog->zl_os); 173 zc->zc_word[ZIL_ZC_SEQ] = 1ULL; 174 } 175 176 /* 177 * Read a log block and make sure it's valid. 178 */ 179 static int 180 zil_read_log_block(zilog_t *zilog, const blkptr_t *bp, blkptr_t *nbp, void *dst, 181 char **end) 182 { 183 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL; 184 uint32_t aflags = ARC_WAIT; 185 arc_buf_t *abuf = NULL; 186 zbookmark_t zb; 187 int error; 188 189 if (zilog->zl_header->zh_claim_txg == 0) 190 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; 191 192 if (!(zilog->zl_header->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) 193 zio_flags |= ZIO_FLAG_SPECULATIVE; 194 195 SET_BOOKMARK(&zb, bp->blk_cksum.zc_word[ZIL_ZC_OBJSET], 196 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]); 197 198 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf, 199 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); 200 201 if (error == 0) { 202 zio_cksum_t cksum = bp->blk_cksum; 203 204 /* 205 * Validate the checksummed log block. 206 * 207 * Sequence numbers should be... sequential. The checksum 208 * verifier for the next block should be bp's checksum plus 1. 209 * 210 * Also check the log chain linkage and size used. 211 */ 212 cksum.zc_word[ZIL_ZC_SEQ]++; 213 214 if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) { 215 zil_chain_t *zilc = abuf->b_data; 216 char *lr = (char *)(zilc + 1); 217 uint64_t len = zilc->zc_nused - sizeof (zil_chain_t); 218 219 if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum, 220 sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk)) { 221 error = SET_ERROR(ECKSUM); 222 } else { 223 bcopy(lr, dst, len); 224 *end = (char *)dst + len; 225 *nbp = zilc->zc_next_blk; 226 } 227 } else { 228 char *lr = abuf->b_data; 229 uint64_t size = BP_GET_LSIZE(bp); 230 zil_chain_t *zilc = (zil_chain_t *)(lr + size) - 1; 231 232 if (bcmp(&cksum, &zilc->zc_next_blk.blk_cksum, 233 sizeof (cksum)) || BP_IS_HOLE(&zilc->zc_next_blk) || 234 (zilc->zc_nused > (size - sizeof (*zilc)))) { 235 error = SET_ERROR(ECKSUM); 236 } else { 237 bcopy(lr, dst, zilc->zc_nused); 238 *end = (char *)dst + zilc->zc_nused; 239 *nbp = zilc->zc_next_blk; 240 } 241 } 242 243 VERIFY(arc_buf_remove_ref(abuf, &abuf)); 244 } 245 246 return (error); 247 } 248 249 /* 250 * Read a TX_WRITE log data block. 251 */ 252 static int 253 zil_read_log_data(zilog_t *zilog, const lr_write_t *lr, void *wbuf) 254 { 255 enum zio_flag zio_flags = ZIO_FLAG_CANFAIL; 256 const blkptr_t *bp = &lr->lr_blkptr; 257 uint32_t aflags = ARC_WAIT; 258 arc_buf_t *abuf = NULL; 259 zbookmark_t zb; 260 int error; 261 262 if (BP_IS_HOLE(bp)) { 263 if (wbuf != NULL) 264 bzero(wbuf, MAX(BP_GET_LSIZE(bp), lr->lr_length)); 265 return (0); 266 } 267 268 if (zilog->zl_header->zh_claim_txg == 0) 269 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; 270 271 SET_BOOKMARK(&zb, dmu_objset_id(zilog->zl_os), lr->lr_foid, 272 ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp)); 273 274 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf, 275 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); 276 277 if (error == 0) { 278 if (wbuf != NULL) 279 bcopy(abuf->b_data, wbuf, arc_buf_size(abuf)); 280 (void) arc_buf_remove_ref(abuf, &abuf); 281 } 282 283 return (error); 284 } 285 286 /* 287 * Parse the intent log, and call parse_func for each valid record within. 288 */ 289 int 290 zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func, 291 zil_parse_lr_func_t *parse_lr_func, void *arg, uint64_t txg) 292 { 293 const zil_header_t *zh = zilog->zl_header; 294 boolean_t claimed = !!zh->zh_claim_txg; 295 uint64_t claim_blk_seq = claimed ? zh->zh_claim_blk_seq : UINT64_MAX; 296 uint64_t claim_lr_seq = claimed ? zh->zh_claim_lr_seq : UINT64_MAX; 297 uint64_t max_blk_seq = 0; 298 uint64_t max_lr_seq = 0; 299 uint64_t blk_count = 0; 300 uint64_t lr_count = 0; 301 blkptr_t blk, next_blk; 302 char *lrbuf, *lrp; 303 int error = 0; 304 305 /* 306 * Old logs didn't record the maximum zh_claim_lr_seq. 307 */ 308 if (!(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) 309 claim_lr_seq = UINT64_MAX; 310 311 /* 312 * Starting at the block pointed to by zh_log we read the log chain. 313 * For each block in the chain we strongly check that block to 314 * ensure its validity. We stop when an invalid block is found. 315 * For each block pointer in the chain we call parse_blk_func(). 316 * For each record in each valid block we call parse_lr_func(). 317 * If the log has been claimed, stop if we encounter a sequence 318 * number greater than the highest claimed sequence number. 319 */ 320 lrbuf = zio_buf_alloc(SPA_MAXBLOCKSIZE); 321 zil_bp_tree_init(zilog); 322 323 for (blk = zh->zh_log; !BP_IS_HOLE(&blk); blk = next_blk) { 324 uint64_t blk_seq = blk.blk_cksum.zc_word[ZIL_ZC_SEQ]; 325 int reclen; 326 char *end; 327 328 if (blk_seq > claim_blk_seq) 329 break; 330 if ((error = parse_blk_func(zilog, &blk, arg, txg)) != 0) 331 break; 332 ASSERT3U(max_blk_seq, <, blk_seq); 333 max_blk_seq = blk_seq; 334 blk_count++; 335 336 if (max_lr_seq == claim_lr_seq && max_blk_seq == claim_blk_seq) 337 break; 338 339 error = zil_read_log_block(zilog, &blk, &next_blk, lrbuf, &end); 340 if (error != 0) 341 break; 342 343 for (lrp = lrbuf; lrp < end; lrp += reclen) { 344 lr_t *lr = (lr_t *)lrp; 345 reclen = lr->lrc_reclen; 346 ASSERT3U(reclen, >=, sizeof (lr_t)); 347 if (lr->lrc_seq > claim_lr_seq) 348 goto done; 349 if ((error = parse_lr_func(zilog, lr, arg, txg)) != 0) 350 goto done; 351 ASSERT3U(max_lr_seq, <, lr->lrc_seq); 352 max_lr_seq = lr->lrc_seq; 353 lr_count++; 354 } 355 } 356 done: 357 zilog->zl_parse_error = error; 358 zilog->zl_parse_blk_seq = max_blk_seq; 359 zilog->zl_parse_lr_seq = max_lr_seq; 360 zilog->zl_parse_blk_count = blk_count; 361 zilog->zl_parse_lr_count = lr_count; 362 363 ASSERT(!claimed || !(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID) || 364 (max_blk_seq == claim_blk_seq && max_lr_seq == claim_lr_seq)); 365 366 zil_bp_tree_fini(zilog); 367 zio_buf_free(lrbuf, SPA_MAXBLOCKSIZE); 368 369 return (error); 370 } 371 372 static int 373 zil_claim_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t first_txg) 374 { 375 /* 376 * Claim log block if not already committed and not already claimed. 377 * If tx == NULL, just verify that the block is claimable. 378 */ 379 if (BP_IS_HOLE(bp) || bp->blk_birth < first_txg || 380 zil_bp_tree_add(zilog, bp) != 0) 381 return (0); 382 383 return (zio_wait(zio_claim(NULL, zilog->zl_spa, 384 tx == NULL ? 0 : first_txg, bp, spa_claim_notify, NULL, 385 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB))); 386 } 387 388 static int 389 zil_claim_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t first_txg) 390 { 391 lr_write_t *lr = (lr_write_t *)lrc; 392 int error; 393 394 if (lrc->lrc_txtype != TX_WRITE) 395 return (0); 396 397 /* 398 * If the block is not readable, don't claim it. This can happen 399 * in normal operation when a log block is written to disk before 400 * some of the dmu_sync() blocks it points to. In this case, the 401 * transaction cannot have been committed to anyone (we would have 402 * waited for all writes to be stable first), so it is semantically 403 * correct to declare this the end of the log. 404 */ 405 if (lr->lr_blkptr.blk_birth >= first_txg && 406 (error = zil_read_log_data(zilog, lr, NULL)) != 0) 407 return (error); 408 return (zil_claim_log_block(zilog, &lr->lr_blkptr, tx, first_txg)); 409 } 410 411 /* ARGSUSED */ 412 static int 413 zil_free_log_block(zilog_t *zilog, blkptr_t *bp, void *tx, uint64_t claim_txg) 414 { 415 zio_free_zil(zilog->zl_spa, dmu_tx_get_txg(tx), bp); 416 417 return (0); 418 } 419 420 static int 421 zil_free_log_record(zilog_t *zilog, lr_t *lrc, void *tx, uint64_t claim_txg) 422 { 423 lr_write_t *lr = (lr_write_t *)lrc; 424 blkptr_t *bp = &lr->lr_blkptr; 425 426 /* 427 * If we previously claimed it, we need to free it. 428 */ 429 if (claim_txg != 0 && lrc->lrc_txtype == TX_WRITE && 430 bp->blk_birth >= claim_txg && zil_bp_tree_add(zilog, bp) == 0 && 431 !BP_IS_HOLE(bp)) 432 zio_free(zilog->zl_spa, dmu_tx_get_txg(tx), bp); 433 434 return (0); 435 } 436 437 static lwb_t * 438 zil_alloc_lwb(zilog_t *zilog, blkptr_t *bp, uint64_t txg) 439 { 440 lwb_t *lwb; 441 442 lwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP); 443 lwb->lwb_zilog = zilog; 444 lwb->lwb_blk = *bp; 445 lwb->lwb_buf = zio_buf_alloc(BP_GET_LSIZE(bp)); 446 lwb->lwb_max_txg = txg; 447 lwb->lwb_zio = NULL; 448 lwb->lwb_tx = NULL; 449 if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) { 450 lwb->lwb_nused = sizeof (zil_chain_t); 451 lwb->lwb_sz = BP_GET_LSIZE(bp); 452 } else { 453 lwb->lwb_nused = 0; 454 lwb->lwb_sz = BP_GET_LSIZE(bp) - sizeof (zil_chain_t); 455 } 456 457 mutex_enter(&zilog->zl_lock); 458 list_insert_tail(&zilog->zl_lwb_list, lwb); 459 mutex_exit(&zilog->zl_lock); 460 461 return (lwb); 462 } 463 464 /* 465 * Called when we create in-memory log transactions so that we know 466 * to cleanup the itxs at the end of spa_sync(). 467 */ 468 void 469 zilog_dirty(zilog_t *zilog, uint64_t txg) 470 { 471 dsl_pool_t *dp = zilog->zl_dmu_pool; 472 dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os); 473 474 if (dsl_dataset_is_snapshot(ds)) 475 panic("dirtying snapshot!"); 476 477 if (txg_list_add(&dp->dp_dirty_zilogs, zilog, txg)) { 478 /* up the hold count until we can be written out */ 479 dmu_buf_add_ref(ds->ds_dbuf, zilog); 480 } 481 } 482 483 boolean_t 484 zilog_is_dirty(zilog_t *zilog) 485 { 486 dsl_pool_t *dp = zilog->zl_dmu_pool; 487 488 for (int t = 0; t < TXG_SIZE; t++) { 489 if (txg_list_member(&dp->dp_dirty_zilogs, zilog, t)) 490 return (B_TRUE); 491 } 492 return (B_FALSE); 493 } 494 495 /* 496 * Create an on-disk intent log. 497 */ 498 static lwb_t * 499 zil_create(zilog_t *zilog) 500 { 501 const zil_header_t *zh = zilog->zl_header; 502 lwb_t *lwb = NULL; 503 uint64_t txg = 0; 504 dmu_tx_t *tx = NULL; 505 blkptr_t blk; 506 int error = 0; 507 508 /* 509 * Wait for any previous destroy to complete. 510 */ 511 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 512 513 ASSERT(zh->zh_claim_txg == 0); 514 ASSERT(zh->zh_replay_seq == 0); 515 516 blk = zh->zh_log; 517 518 /* 519 * Allocate an initial log block if: 520 * - there isn't one already 521 * - the existing block is the wrong endianess 522 */ 523 if (BP_IS_HOLE(&blk) || BP_SHOULD_BYTESWAP(&blk)) { 524 tx = dmu_tx_create(zilog->zl_os); 525 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 526 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 527 txg = dmu_tx_get_txg(tx); 528 529 if (!BP_IS_HOLE(&blk)) { 530 zio_free_zil(zilog->zl_spa, txg, &blk); 531 BP_ZERO(&blk); 532 } 533 534 error = zio_alloc_zil(zilog->zl_spa, txg, &blk, NULL, 535 ZIL_MIN_BLKSZ, zilog->zl_logbias == ZFS_LOGBIAS_LATENCY); 536 537 if (error == 0) 538 zil_init_log_chain(zilog, &blk); 539 } 540 541 /* 542 * Allocate a log write buffer (lwb) for the first log block. 543 */ 544 if (error == 0) 545 lwb = zil_alloc_lwb(zilog, &blk, txg); 546 547 /* 548 * If we just allocated the first log block, commit our transaction 549 * and wait for zil_sync() to stuff the block poiner into zh_log. 550 * (zh is part of the MOS, so we cannot modify it in open context.) 551 */ 552 if (tx != NULL) { 553 dmu_tx_commit(tx); 554 txg_wait_synced(zilog->zl_dmu_pool, txg); 555 } 556 557 ASSERT(bcmp(&blk, &zh->zh_log, sizeof (blk)) == 0); 558 559 return (lwb); 560 } 561 562 /* 563 * In one tx, free all log blocks and clear the log header. 564 * If keep_first is set, then we're replaying a log with no content. 565 * We want to keep the first block, however, so that the first 566 * synchronous transaction doesn't require a txg_wait_synced() 567 * in zil_create(). We don't need to txg_wait_synced() here either 568 * when keep_first is set, because both zil_create() and zil_destroy() 569 * will wait for any in-progress destroys to complete. 570 */ 571 void 572 zil_destroy(zilog_t *zilog, boolean_t keep_first) 573 { 574 const zil_header_t *zh = zilog->zl_header; 575 lwb_t *lwb; 576 dmu_tx_t *tx; 577 uint64_t txg; 578 579 /* 580 * Wait for any previous destroy to complete. 581 */ 582 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 583 584 zilog->zl_old_header = *zh; /* debugging aid */ 585 586 if (BP_IS_HOLE(&zh->zh_log)) 587 return; 588 589 tx = dmu_tx_create(zilog->zl_os); 590 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 591 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 592 txg = dmu_tx_get_txg(tx); 593 594 mutex_enter(&zilog->zl_lock); 595 596 ASSERT3U(zilog->zl_destroy_txg, <, txg); 597 zilog->zl_destroy_txg = txg; 598 zilog->zl_keep_first = keep_first; 599 600 if (!list_is_empty(&zilog->zl_lwb_list)) { 601 ASSERT(zh->zh_claim_txg == 0); 602 VERIFY(!keep_first); 603 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { 604 list_remove(&zilog->zl_lwb_list, lwb); 605 if (lwb->lwb_buf != NULL) 606 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 607 zio_free_zil(zilog->zl_spa, txg, &lwb->lwb_blk); 608 kmem_cache_free(zil_lwb_cache, lwb); 609 } 610 } else if (!keep_first) { 611 zil_destroy_sync(zilog, tx); 612 } 613 mutex_exit(&zilog->zl_lock); 614 615 dmu_tx_commit(tx); 616 } 617 618 void 619 zil_destroy_sync(zilog_t *zilog, dmu_tx_t *tx) 620 { 621 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 622 (void) zil_parse(zilog, zil_free_log_block, 623 zil_free_log_record, tx, zilog->zl_header->zh_claim_txg); 624 } 625 626 int 627 zil_claim(const char *osname, void *txarg) 628 { 629 dmu_tx_t *tx = txarg; 630 uint64_t first_txg = dmu_tx_get_txg(tx); 631 zilog_t *zilog; 632 zil_header_t *zh; 633 objset_t *os; 634 int error; 635 636 error = dmu_objset_own(osname, DMU_OST_ANY, B_FALSE, FTAG, &os); 637 if (error != 0) { 638 cmn_err(CE_WARN, "can't open objset for %s", osname); 639 return (0); 640 } 641 642 zilog = dmu_objset_zil(os); 643 zh = zil_header_in_syncing_context(zilog); 644 645 if (spa_get_log_state(zilog->zl_spa) == SPA_LOG_CLEAR) { 646 if (!BP_IS_HOLE(&zh->zh_log)) 647 zio_free_zil(zilog->zl_spa, first_txg, &zh->zh_log); 648 BP_ZERO(&zh->zh_log); 649 dsl_dataset_dirty(dmu_objset_ds(os), tx); 650 dmu_objset_disown(os, FTAG); 651 return (0); 652 } 653 654 /* 655 * Claim all log blocks if we haven't already done so, and remember 656 * the highest claimed sequence number. This ensures that if we can 657 * read only part of the log now (e.g. due to a missing device), 658 * but we can read the entire log later, we will not try to replay 659 * or destroy beyond the last block we successfully claimed. 660 */ 661 ASSERT3U(zh->zh_claim_txg, <=, first_txg); 662 if (zh->zh_claim_txg == 0 && !BP_IS_HOLE(&zh->zh_log)) { 663 (void) zil_parse(zilog, zil_claim_log_block, 664 zil_claim_log_record, tx, first_txg); 665 zh->zh_claim_txg = first_txg; 666 zh->zh_claim_blk_seq = zilog->zl_parse_blk_seq; 667 zh->zh_claim_lr_seq = zilog->zl_parse_lr_seq; 668 if (zilog->zl_parse_lr_count || zilog->zl_parse_blk_count > 1) 669 zh->zh_flags |= ZIL_REPLAY_NEEDED; 670 zh->zh_flags |= ZIL_CLAIM_LR_SEQ_VALID; 671 dsl_dataset_dirty(dmu_objset_ds(os), tx); 672 } 673 674 ASSERT3U(first_txg, ==, (spa_last_synced_txg(zilog->zl_spa) + 1)); 675 dmu_objset_disown(os, FTAG); 676 return (0); 677 } 678 679 /* 680 * Check the log by walking the log chain. 681 * Checksum errors are ok as they indicate the end of the chain. 682 * Any other error (no device or read failure) returns an error. 683 */ 684 int 685 zil_check_log_chain(const char *osname, void *tx) 686 { 687 zilog_t *zilog; 688 objset_t *os; 689 blkptr_t *bp; 690 int error; 691 692 ASSERT(tx == NULL); 693 694 error = dmu_objset_hold(osname, FTAG, &os); 695 if (error != 0) { 696 cmn_err(CE_WARN, "can't open objset for %s", osname); 697 return (0); 698 } 699 700 zilog = dmu_objset_zil(os); 701 bp = (blkptr_t *)&zilog->zl_header->zh_log; 702 703 /* 704 * Check the first block and determine if it's on a log device 705 * which may have been removed or faulted prior to loading this 706 * pool. If so, there's no point in checking the rest of the log 707 * as its content should have already been synced to the pool. 708 */ 709 if (!BP_IS_HOLE(bp)) { 710 vdev_t *vd; 711 boolean_t valid = B_TRUE; 712 713 spa_config_enter(os->os_spa, SCL_STATE, FTAG, RW_READER); 714 vd = vdev_lookup_top(os->os_spa, DVA_GET_VDEV(&bp->blk_dva[0])); 715 if (vd->vdev_islog && vdev_is_dead(vd)) 716 valid = vdev_log_state_valid(vd); 717 spa_config_exit(os->os_spa, SCL_STATE, FTAG); 718 719 if (!valid) { 720 dmu_objset_rele(os, FTAG); 721 return (0); 722 } 723 } 724 725 /* 726 * Because tx == NULL, zil_claim_log_block() will not actually claim 727 * any blocks, but just determine whether it is possible to do so. 728 * In addition to checking the log chain, zil_claim_log_block() 729 * will invoke zio_claim() with a done func of spa_claim_notify(), 730 * which will update spa_max_claim_txg. See spa_load() for details. 731 */ 732 error = zil_parse(zilog, zil_claim_log_block, zil_claim_log_record, tx, 733 zilog->zl_header->zh_claim_txg ? -1ULL : spa_first_txg(os->os_spa)); 734 735 dmu_objset_rele(os, FTAG); 736 737 return ((error == ECKSUM || error == ENOENT) ? 0 : error); 738 } 739 740 static int 741 zil_vdev_compare(const void *x1, const void *x2) 742 { 743 const uint64_t v1 = ((zil_vdev_node_t *)x1)->zv_vdev; 744 const uint64_t v2 = ((zil_vdev_node_t *)x2)->zv_vdev; 745 746 if (v1 < v2) 747 return (-1); 748 if (v1 > v2) 749 return (1); 750 751 return (0); 752 } 753 754 void 755 zil_add_block(zilog_t *zilog, const blkptr_t *bp) 756 { 757 avl_tree_t *t = &zilog->zl_vdev_tree; 758 avl_index_t where; 759 zil_vdev_node_t *zv, zvsearch; 760 int ndvas = BP_GET_NDVAS(bp); 761 int i; 762 763 if (zfs_nocacheflush) 764 return; 765 766 ASSERT(zilog->zl_writer); 767 768 /* 769 * Even though we're zl_writer, we still need a lock because the 770 * zl_get_data() callbacks may have dmu_sync() done callbacks 771 * that will run concurrently. 772 */ 773 mutex_enter(&zilog->zl_vdev_lock); 774 for (i = 0; i < ndvas; i++) { 775 zvsearch.zv_vdev = DVA_GET_VDEV(&bp->blk_dva[i]); 776 if (avl_find(t, &zvsearch, &where) == NULL) { 777 zv = kmem_alloc(sizeof (*zv), KM_SLEEP); 778 zv->zv_vdev = zvsearch.zv_vdev; 779 avl_insert(t, zv, where); 780 } 781 } 782 mutex_exit(&zilog->zl_vdev_lock); 783 } 784 785 static void 786 zil_flush_vdevs(zilog_t *zilog) 787 { 788 spa_t *spa = zilog->zl_spa; 789 avl_tree_t *t = &zilog->zl_vdev_tree; 790 void *cookie = NULL; 791 zil_vdev_node_t *zv; 792 zio_t *zio; 793 794 ASSERT(zilog->zl_writer); 795 796 /* 797 * We don't need zl_vdev_lock here because we're the zl_writer, 798 * and all zl_get_data() callbacks are done. 799 */ 800 if (avl_numnodes(t) == 0) 801 return; 802 803 spa_config_enter(spa, SCL_STATE, FTAG, RW_READER); 804 805 zio = zio_root(spa, NULL, NULL, ZIO_FLAG_CANFAIL); 806 807 while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) { 808 vdev_t *vd = vdev_lookup_top(spa, zv->zv_vdev); 809 if (vd != NULL) 810 zio_flush(zio, vd); 811 kmem_free(zv, sizeof (*zv)); 812 } 813 814 /* 815 * Wait for all the flushes to complete. Not all devices actually 816 * support the DKIOCFLUSHWRITECACHE ioctl, so it's OK if it fails. 817 */ 818 (void) zio_wait(zio); 819 820 spa_config_exit(spa, SCL_STATE, FTAG); 821 } 822 823 /* 824 * Function called when a log block write completes 825 */ 826 static void 827 zil_lwb_write_done(zio_t *zio) 828 { 829 lwb_t *lwb = zio->io_private; 830 zilog_t *zilog = lwb->lwb_zilog; 831 dmu_tx_t *tx = lwb->lwb_tx; 832 833 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 834 ASSERT(BP_GET_TYPE(zio->io_bp) == DMU_OT_INTENT_LOG); 835 ASSERT(BP_GET_LEVEL(zio->io_bp) == 0); 836 ASSERT(BP_GET_BYTEORDER(zio->io_bp) == ZFS_HOST_BYTEORDER); 837 ASSERT(!BP_IS_GANG(zio->io_bp)); 838 ASSERT(!BP_IS_HOLE(zio->io_bp)); 839 ASSERT(BP_GET_FILL(zio->io_bp) == 0); 840 841 /* 842 * Ensure the lwb buffer pointer is cleared before releasing 843 * the txg. If we have had an allocation failure and 844 * the txg is waiting to sync then we want want zil_sync() 845 * to remove the lwb so that it's not picked up as the next new 846 * one in zil_commit_writer(). zil_sync() will only remove 847 * the lwb if lwb_buf is null. 848 */ 849 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 850 mutex_enter(&zilog->zl_lock); 851 lwb->lwb_buf = NULL; 852 lwb->lwb_tx = NULL; 853 mutex_exit(&zilog->zl_lock); 854 855 /* 856 * Now that we've written this log block, we have a stable pointer 857 * to the next block in the chain, so it's OK to let the txg in 858 * which we allocated the next block sync. 859 */ 860 dmu_tx_commit(tx); 861 } 862 863 /* 864 * Initialize the io for a log block. 865 */ 866 static void 867 zil_lwb_write_init(zilog_t *zilog, lwb_t *lwb) 868 { 869 zbookmark_t zb; 870 871 SET_BOOKMARK(&zb, lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_OBJSET], 872 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, 873 lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_SEQ]); 874 875 if (zilog->zl_root_zio == NULL) { 876 zilog->zl_root_zio = zio_root(zilog->zl_spa, NULL, NULL, 877 ZIO_FLAG_CANFAIL); 878 } 879 if (lwb->lwb_zio == NULL) { 880 lwb->lwb_zio = zio_rewrite(zilog->zl_root_zio, zilog->zl_spa, 881 0, &lwb->lwb_blk, lwb->lwb_buf, BP_GET_LSIZE(&lwb->lwb_blk), 882 zil_lwb_write_done, lwb, ZIO_PRIORITY_SYNC_WRITE, 883 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE, &zb); 884 } 885 } 886 887 /* 888 * Define a limited set of intent log block sizes. 889 * 890 * These must be a multiple of 4KB. Note only the amount used (again 891 * aligned to 4KB) actually gets written. However, we can't always just 892 * allocate SPA_MAXBLOCKSIZE as the slog space could be exhausted. 893 */ 894 uint64_t zil_block_buckets[] = { 895 4096, /* non TX_WRITE */ 896 8192+4096, /* data base */ 897 32*1024 + 4096, /* NFS writes */ 898 UINT64_MAX 899 }; 900 901 /* 902 * Use the slog as long as the logbias is 'latency' and the current commit size 903 * is less than the limit or the total list size is less than 2X the limit. 904 * Limit checking is disabled by setting zil_slog_limit to UINT64_MAX. 905 */ 906 uint64_t zil_slog_limit = 1024 * 1024; 907 #define USE_SLOG(zilog) (((zilog)->zl_logbias == ZFS_LOGBIAS_LATENCY) && \ 908 (((zilog)->zl_cur_used < zil_slog_limit) || \ 909 ((zilog)->zl_itx_list_sz < (zil_slog_limit << 1)))) 910 911 /* 912 * Start a log block write and advance to the next log block. 913 * Calls are serialized. 914 */ 915 static lwb_t * 916 zil_lwb_write_start(zilog_t *zilog, lwb_t *lwb) 917 { 918 lwb_t *nlwb = NULL; 919 zil_chain_t *zilc; 920 spa_t *spa = zilog->zl_spa; 921 blkptr_t *bp; 922 dmu_tx_t *tx; 923 uint64_t txg; 924 uint64_t zil_blksz, wsz; 925 int i, error; 926 927 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) { 928 zilc = (zil_chain_t *)lwb->lwb_buf; 929 bp = &zilc->zc_next_blk; 930 } else { 931 zilc = (zil_chain_t *)(lwb->lwb_buf + lwb->lwb_sz); 932 bp = &zilc->zc_next_blk; 933 } 934 935 ASSERT(lwb->lwb_nused <= lwb->lwb_sz); 936 937 /* 938 * Allocate the next block and save its address in this block 939 * before writing it in order to establish the log chain. 940 * Note that if the allocation of nlwb synced before we wrote 941 * the block that points at it (lwb), we'd leak it if we crashed. 942 * Therefore, we don't do dmu_tx_commit() until zil_lwb_write_done(). 943 * We dirty the dataset to ensure that zil_sync() will be called 944 * to clean up in the event of allocation failure or I/O failure. 945 */ 946 tx = dmu_tx_create(zilog->zl_os); 947 VERIFY(dmu_tx_assign(tx, TXG_WAIT) == 0); 948 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 949 txg = dmu_tx_get_txg(tx); 950 951 lwb->lwb_tx = tx; 952 953 /* 954 * Log blocks are pre-allocated. Here we select the size of the next 955 * block, based on size used in the last block. 956 * - first find the smallest bucket that will fit the block from a 957 * limited set of block sizes. This is because it's faster to write 958 * blocks allocated from the same metaslab as they are adjacent or 959 * close. 960 * - next find the maximum from the new suggested size and an array of 961 * previous sizes. This lessens a picket fence effect of wrongly 962 * guesssing the size if we have a stream of say 2k, 64k, 2k, 64k 963 * requests. 964 * 965 * Note we only write what is used, but we can't just allocate 966 * the maximum block size because we can exhaust the available 967 * pool log space. 968 */ 969 zil_blksz = zilog->zl_cur_used + sizeof (zil_chain_t); 970 for (i = 0; zil_blksz > zil_block_buckets[i]; i++) 971 continue; 972 zil_blksz = zil_block_buckets[i]; 973 if (zil_blksz == UINT64_MAX) 974 zil_blksz = SPA_MAXBLOCKSIZE; 975 zilog->zl_prev_blks[zilog->zl_prev_rotor] = zil_blksz; 976 for (i = 0; i < ZIL_PREV_BLKS; i++) 977 zil_blksz = MAX(zil_blksz, zilog->zl_prev_blks[i]); 978 zilog->zl_prev_rotor = (zilog->zl_prev_rotor + 1) & (ZIL_PREV_BLKS - 1); 979 980 BP_ZERO(bp); 981 /* pass the old blkptr in order to spread log blocks across devs */ 982 error = zio_alloc_zil(spa, txg, bp, &lwb->lwb_blk, zil_blksz, 983 USE_SLOG(zilog)); 984 if (error == 0) { 985 ASSERT3U(bp->blk_birth, ==, txg); 986 bp->blk_cksum = lwb->lwb_blk.blk_cksum; 987 bp->blk_cksum.zc_word[ZIL_ZC_SEQ]++; 988 989 /* 990 * Allocate a new log write buffer (lwb). 991 */ 992 nlwb = zil_alloc_lwb(zilog, bp, txg); 993 994 /* Record the block for later vdev flushing */ 995 zil_add_block(zilog, &lwb->lwb_blk); 996 } 997 998 if (BP_GET_CHECKSUM(&lwb->lwb_blk) == ZIO_CHECKSUM_ZILOG2) { 999 /* For Slim ZIL only write what is used. */ 1000 wsz = P2ROUNDUP_TYPED(lwb->lwb_nused, ZIL_MIN_BLKSZ, uint64_t); 1001 ASSERT3U(wsz, <=, lwb->lwb_sz); 1002 zio_shrink(lwb->lwb_zio, wsz); 1003 1004 } else { 1005 wsz = lwb->lwb_sz; 1006 } 1007 1008 zilc->zc_pad = 0; 1009 zilc->zc_nused = lwb->lwb_nused; 1010 zilc->zc_eck.zec_cksum = lwb->lwb_blk.blk_cksum; 1011 1012 /* 1013 * clear unused data for security 1014 */ 1015 bzero(lwb->lwb_buf + lwb->lwb_nused, wsz - lwb->lwb_nused); 1016 1017 zio_nowait(lwb->lwb_zio); /* Kick off the write for the old log block */ 1018 1019 /* 1020 * If there was an allocation failure then nlwb will be null which 1021 * forces a txg_wait_synced(). 1022 */ 1023 return (nlwb); 1024 } 1025 1026 static lwb_t * 1027 zil_lwb_commit(zilog_t *zilog, itx_t *itx, lwb_t *lwb) 1028 { 1029 lr_t *lrc = &itx->itx_lr; /* common log record */ 1030 lr_write_t *lrw = (lr_write_t *)lrc; 1031 char *lr_buf; 1032 uint64_t txg = lrc->lrc_txg; 1033 uint64_t reclen = lrc->lrc_reclen; 1034 uint64_t dlen = 0; 1035 1036 if (lwb == NULL) 1037 return (NULL); 1038 1039 ASSERT(lwb->lwb_buf != NULL); 1040 ASSERT(zilog_is_dirty(zilog) || 1041 spa_freeze_txg(zilog->zl_spa) != UINT64_MAX); 1042 1043 if (lrc->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY) 1044 dlen = P2ROUNDUP_TYPED( 1045 lrw->lr_length, sizeof (uint64_t), uint64_t); 1046 1047 zilog->zl_cur_used += (reclen + dlen); 1048 1049 zil_lwb_write_init(zilog, lwb); 1050 1051 /* 1052 * If this record won't fit in the current log block, start a new one. 1053 */ 1054 if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) { 1055 lwb = zil_lwb_write_start(zilog, lwb); 1056 if (lwb == NULL) 1057 return (NULL); 1058 zil_lwb_write_init(zilog, lwb); 1059 ASSERT(LWB_EMPTY(lwb)); 1060 if (lwb->lwb_nused + reclen + dlen > lwb->lwb_sz) { 1061 txg_wait_synced(zilog->zl_dmu_pool, txg); 1062 return (lwb); 1063 } 1064 } 1065 1066 lr_buf = lwb->lwb_buf + lwb->lwb_nused; 1067 bcopy(lrc, lr_buf, reclen); 1068 lrc = (lr_t *)lr_buf; 1069 lrw = (lr_write_t *)lrc; 1070 1071 /* 1072 * If it's a write, fetch the data or get its blkptr as appropriate. 1073 */ 1074 if (lrc->lrc_txtype == TX_WRITE) { 1075 if (txg > spa_freeze_txg(zilog->zl_spa)) 1076 txg_wait_synced(zilog->zl_dmu_pool, txg); 1077 if (itx->itx_wr_state != WR_COPIED) { 1078 char *dbuf; 1079 int error; 1080 1081 if (dlen) { 1082 ASSERT(itx->itx_wr_state == WR_NEED_COPY); 1083 dbuf = lr_buf + reclen; 1084 lrw->lr_common.lrc_reclen += dlen; 1085 } else { 1086 ASSERT(itx->itx_wr_state == WR_INDIRECT); 1087 dbuf = NULL; 1088 } 1089 error = zilog->zl_get_data( 1090 itx->itx_private, lrw, dbuf, lwb->lwb_zio); 1091 if (error == EIO) { 1092 txg_wait_synced(zilog->zl_dmu_pool, txg); 1093 return (lwb); 1094 } 1095 if (error != 0) { 1096 ASSERT(error == ENOENT || error == EEXIST || 1097 error == EALREADY); 1098 return (lwb); 1099 } 1100 } 1101 } 1102 1103 /* 1104 * We're actually making an entry, so update lrc_seq to be the 1105 * log record sequence number. Note that this is generally not 1106 * equal to the itx sequence number because not all transactions 1107 * are synchronous, and sometimes spa_sync() gets there first. 1108 */ 1109 lrc->lrc_seq = ++zilog->zl_lr_seq; /* we are single threaded */ 1110 lwb->lwb_nused += reclen + dlen; 1111 lwb->lwb_max_txg = MAX(lwb->lwb_max_txg, txg); 1112 ASSERT3U(lwb->lwb_nused, <=, lwb->lwb_sz); 1113 ASSERT0(P2PHASE(lwb->lwb_nused, sizeof (uint64_t))); 1114 1115 return (lwb); 1116 } 1117 1118 itx_t * 1119 zil_itx_create(uint64_t txtype, size_t lrsize) 1120 { 1121 itx_t *itx; 1122 1123 lrsize = P2ROUNDUP_TYPED(lrsize, sizeof (uint64_t), size_t); 1124 1125 itx = kmem_alloc(offsetof(itx_t, itx_lr) + lrsize, KM_SLEEP); 1126 itx->itx_lr.lrc_txtype = txtype; 1127 itx->itx_lr.lrc_reclen = lrsize; 1128 itx->itx_sod = lrsize; /* if write & WR_NEED_COPY will be increased */ 1129 itx->itx_lr.lrc_seq = 0; /* defensive */ 1130 itx->itx_sync = B_TRUE; /* default is synchronous */ 1131 1132 return (itx); 1133 } 1134 1135 void 1136 zil_itx_destroy(itx_t *itx) 1137 { 1138 kmem_free(itx, offsetof(itx_t, itx_lr) + itx->itx_lr.lrc_reclen); 1139 } 1140 1141 /* 1142 * Free up the sync and async itxs. The itxs_t has already been detached 1143 * so no locks are needed. 1144 */ 1145 static void 1146 zil_itxg_clean(itxs_t *itxs) 1147 { 1148 itx_t *itx; 1149 list_t *list; 1150 avl_tree_t *t; 1151 void *cookie; 1152 itx_async_node_t *ian; 1153 1154 list = &itxs->i_sync_list; 1155 while ((itx = list_head(list)) != NULL) { 1156 list_remove(list, itx); 1157 kmem_free(itx, offsetof(itx_t, itx_lr) + 1158 itx->itx_lr.lrc_reclen); 1159 } 1160 1161 cookie = NULL; 1162 t = &itxs->i_async_tree; 1163 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) { 1164 list = &ian->ia_list; 1165 while ((itx = list_head(list)) != NULL) { 1166 list_remove(list, itx); 1167 kmem_free(itx, offsetof(itx_t, itx_lr) + 1168 itx->itx_lr.lrc_reclen); 1169 } 1170 list_destroy(list); 1171 kmem_free(ian, sizeof (itx_async_node_t)); 1172 } 1173 avl_destroy(t); 1174 1175 kmem_free(itxs, sizeof (itxs_t)); 1176 } 1177 1178 static int 1179 zil_aitx_compare(const void *x1, const void *x2) 1180 { 1181 const uint64_t o1 = ((itx_async_node_t *)x1)->ia_foid; 1182 const uint64_t o2 = ((itx_async_node_t *)x2)->ia_foid; 1183 1184 if (o1 < o2) 1185 return (-1); 1186 if (o1 > o2) 1187 return (1); 1188 1189 return (0); 1190 } 1191 1192 /* 1193 * Remove all async itx with the given oid. 1194 */ 1195 static void 1196 zil_remove_async(zilog_t *zilog, uint64_t oid) 1197 { 1198 uint64_t otxg, txg; 1199 itx_async_node_t *ian; 1200 avl_tree_t *t; 1201 avl_index_t where; 1202 list_t clean_list; 1203 itx_t *itx; 1204 1205 ASSERT(oid != 0); 1206 list_create(&clean_list, sizeof (itx_t), offsetof(itx_t, itx_node)); 1207 1208 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1209 otxg = ZILTEST_TXG; 1210 else 1211 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1212 1213 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1214 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1215 1216 mutex_enter(&itxg->itxg_lock); 1217 if (itxg->itxg_txg != txg) { 1218 mutex_exit(&itxg->itxg_lock); 1219 continue; 1220 } 1221 1222 /* 1223 * Locate the object node and append its list. 1224 */ 1225 t = &itxg->itxg_itxs->i_async_tree; 1226 ian = avl_find(t, &oid, &where); 1227 if (ian != NULL) 1228 list_move_tail(&clean_list, &ian->ia_list); 1229 mutex_exit(&itxg->itxg_lock); 1230 } 1231 while ((itx = list_head(&clean_list)) != NULL) { 1232 list_remove(&clean_list, itx); 1233 kmem_free(itx, offsetof(itx_t, itx_lr) + 1234 itx->itx_lr.lrc_reclen); 1235 } 1236 list_destroy(&clean_list); 1237 } 1238 1239 void 1240 zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx) 1241 { 1242 uint64_t txg; 1243 itxg_t *itxg; 1244 itxs_t *itxs, *clean = NULL; 1245 1246 /* 1247 * Object ids can be re-instantiated in the next txg so 1248 * remove any async transactions to avoid future leaks. 1249 * This can happen if a fsync occurs on the re-instantiated 1250 * object for a WR_INDIRECT or WR_NEED_COPY write, which gets 1251 * the new file data and flushes a write record for the old object. 1252 */ 1253 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_REMOVE) 1254 zil_remove_async(zilog, itx->itx_oid); 1255 1256 /* 1257 * Ensure the data of a renamed file is committed before the rename. 1258 */ 1259 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_RENAME) 1260 zil_async_to_sync(zilog, itx->itx_oid); 1261 1262 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) 1263 txg = ZILTEST_TXG; 1264 else 1265 txg = dmu_tx_get_txg(tx); 1266 1267 itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1268 mutex_enter(&itxg->itxg_lock); 1269 itxs = itxg->itxg_itxs; 1270 if (itxg->itxg_txg != txg) { 1271 if (itxs != NULL) { 1272 /* 1273 * The zil_clean callback hasn't got around to cleaning 1274 * this itxg. Save the itxs for release below. 1275 * This should be rare. 1276 */ 1277 atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod); 1278 itxg->itxg_sod = 0; 1279 clean = itxg->itxg_itxs; 1280 } 1281 ASSERT(itxg->itxg_sod == 0); 1282 itxg->itxg_txg = txg; 1283 itxs = itxg->itxg_itxs = kmem_zalloc(sizeof (itxs_t), KM_SLEEP); 1284 1285 list_create(&itxs->i_sync_list, sizeof (itx_t), 1286 offsetof(itx_t, itx_node)); 1287 avl_create(&itxs->i_async_tree, zil_aitx_compare, 1288 sizeof (itx_async_node_t), 1289 offsetof(itx_async_node_t, ia_node)); 1290 } 1291 if (itx->itx_sync) { 1292 list_insert_tail(&itxs->i_sync_list, itx); 1293 atomic_add_64(&zilog->zl_itx_list_sz, itx->itx_sod); 1294 itxg->itxg_sod += itx->itx_sod; 1295 } else { 1296 avl_tree_t *t = &itxs->i_async_tree; 1297 uint64_t foid = ((lr_ooo_t *)&itx->itx_lr)->lr_foid; 1298 itx_async_node_t *ian; 1299 avl_index_t where; 1300 1301 ian = avl_find(t, &foid, &where); 1302 if (ian == NULL) { 1303 ian = kmem_alloc(sizeof (itx_async_node_t), KM_SLEEP); 1304 list_create(&ian->ia_list, sizeof (itx_t), 1305 offsetof(itx_t, itx_node)); 1306 ian->ia_foid = foid; 1307 avl_insert(t, ian, where); 1308 } 1309 list_insert_tail(&ian->ia_list, itx); 1310 } 1311 1312 itx->itx_lr.lrc_txg = dmu_tx_get_txg(tx); 1313 zilog_dirty(zilog, txg); 1314 mutex_exit(&itxg->itxg_lock); 1315 1316 /* Release the old itxs now we've dropped the lock */ 1317 if (clean != NULL) 1318 zil_itxg_clean(clean); 1319 } 1320 1321 /* 1322 * If there are any in-memory intent log transactions which have now been 1323 * synced then start up a taskq to free them. We should only do this after we 1324 * have written out the uberblocks (i.e. txg has been comitted) so that 1325 * don't inadvertently clean out in-memory log records that would be required 1326 * by zil_commit(). 1327 */ 1328 void 1329 zil_clean(zilog_t *zilog, uint64_t synced_txg) 1330 { 1331 itxg_t *itxg = &zilog->zl_itxg[synced_txg & TXG_MASK]; 1332 itxs_t *clean_me; 1333 1334 mutex_enter(&itxg->itxg_lock); 1335 if (itxg->itxg_itxs == NULL || itxg->itxg_txg == ZILTEST_TXG) { 1336 mutex_exit(&itxg->itxg_lock); 1337 return; 1338 } 1339 ASSERT3U(itxg->itxg_txg, <=, synced_txg); 1340 ASSERT(itxg->itxg_txg != 0); 1341 ASSERT(zilog->zl_clean_taskq != NULL); 1342 atomic_add_64(&zilog->zl_itx_list_sz, -itxg->itxg_sod); 1343 itxg->itxg_sod = 0; 1344 clean_me = itxg->itxg_itxs; 1345 itxg->itxg_itxs = NULL; 1346 itxg->itxg_txg = 0; 1347 mutex_exit(&itxg->itxg_lock); 1348 /* 1349 * Preferably start a task queue to free up the old itxs but 1350 * if taskq_dispatch can't allocate resources to do that then 1351 * free it in-line. This should be rare. Note, using TQ_SLEEP 1352 * created a bad performance problem. 1353 */ 1354 if (taskq_dispatch(zilog->zl_clean_taskq, 1355 (void (*)(void *))zil_itxg_clean, clean_me, TQ_NOSLEEP) == NULL) 1356 zil_itxg_clean(clean_me); 1357 } 1358 1359 /* 1360 * Get the list of itxs to commit into zl_itx_commit_list. 1361 */ 1362 static void 1363 zil_get_commit_list(zilog_t *zilog) 1364 { 1365 uint64_t otxg, txg; 1366 list_t *commit_list = &zilog->zl_itx_commit_list; 1367 uint64_t push_sod = 0; 1368 1369 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1370 otxg = ZILTEST_TXG; 1371 else 1372 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1373 1374 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1375 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1376 1377 mutex_enter(&itxg->itxg_lock); 1378 if (itxg->itxg_txg != txg) { 1379 mutex_exit(&itxg->itxg_lock); 1380 continue; 1381 } 1382 1383 list_move_tail(commit_list, &itxg->itxg_itxs->i_sync_list); 1384 push_sod += itxg->itxg_sod; 1385 itxg->itxg_sod = 0; 1386 1387 mutex_exit(&itxg->itxg_lock); 1388 } 1389 atomic_add_64(&zilog->zl_itx_list_sz, -push_sod); 1390 } 1391 1392 /* 1393 * Move the async itxs for a specified object to commit into sync lists. 1394 */ 1395 static void 1396 zil_async_to_sync(zilog_t *zilog, uint64_t foid) 1397 { 1398 uint64_t otxg, txg; 1399 itx_async_node_t *ian; 1400 avl_tree_t *t; 1401 avl_index_t where; 1402 1403 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 1404 otxg = ZILTEST_TXG; 1405 else 1406 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 1407 1408 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 1409 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 1410 1411 mutex_enter(&itxg->itxg_lock); 1412 if (itxg->itxg_txg != txg) { 1413 mutex_exit(&itxg->itxg_lock); 1414 continue; 1415 } 1416 1417 /* 1418 * If a foid is specified then find that node and append its 1419 * list. Otherwise walk the tree appending all the lists 1420 * to the sync list. We add to the end rather than the 1421 * beginning to ensure the create has happened. 1422 */ 1423 t = &itxg->itxg_itxs->i_async_tree; 1424 if (foid != 0) { 1425 ian = avl_find(t, &foid, &where); 1426 if (ian != NULL) { 1427 list_move_tail(&itxg->itxg_itxs->i_sync_list, 1428 &ian->ia_list); 1429 } 1430 } else { 1431 void *cookie = NULL; 1432 1433 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) { 1434 list_move_tail(&itxg->itxg_itxs->i_sync_list, 1435 &ian->ia_list); 1436 list_destroy(&ian->ia_list); 1437 kmem_free(ian, sizeof (itx_async_node_t)); 1438 } 1439 } 1440 mutex_exit(&itxg->itxg_lock); 1441 } 1442 } 1443 1444 static void 1445 zil_commit_writer(zilog_t *zilog) 1446 { 1447 uint64_t txg; 1448 itx_t *itx; 1449 lwb_t *lwb; 1450 spa_t *spa = zilog->zl_spa; 1451 int error = 0; 1452 1453 ASSERT(zilog->zl_root_zio == NULL); 1454 1455 mutex_exit(&zilog->zl_lock); 1456 1457 zil_get_commit_list(zilog); 1458 1459 /* 1460 * Return if there's nothing to commit before we dirty the fs by 1461 * calling zil_create(). 1462 */ 1463 if (list_head(&zilog->zl_itx_commit_list) == NULL) { 1464 mutex_enter(&zilog->zl_lock); 1465 return; 1466 } 1467 1468 if (zilog->zl_suspend) { 1469 lwb = NULL; 1470 } else { 1471 lwb = list_tail(&zilog->zl_lwb_list); 1472 if (lwb == NULL) 1473 lwb = zil_create(zilog); 1474 } 1475 1476 DTRACE_PROBE1(zil__cw1, zilog_t *, zilog); 1477 while (itx = list_head(&zilog->zl_itx_commit_list)) { 1478 txg = itx->itx_lr.lrc_txg; 1479 ASSERT(txg); 1480 1481 if (txg > spa_last_synced_txg(spa) || txg > spa_freeze_txg(spa)) 1482 lwb = zil_lwb_commit(zilog, itx, lwb); 1483 list_remove(&zilog->zl_itx_commit_list, itx); 1484 kmem_free(itx, offsetof(itx_t, itx_lr) 1485 + itx->itx_lr.lrc_reclen); 1486 } 1487 DTRACE_PROBE1(zil__cw2, zilog_t *, zilog); 1488 1489 /* write the last block out */ 1490 if (lwb != NULL && lwb->lwb_zio != NULL) 1491 lwb = zil_lwb_write_start(zilog, lwb); 1492 1493 zilog->zl_cur_used = 0; 1494 1495 /* 1496 * Wait if necessary for the log blocks to be on stable storage. 1497 */ 1498 if (zilog->zl_root_zio) { 1499 error = zio_wait(zilog->zl_root_zio); 1500 zilog->zl_root_zio = NULL; 1501 zil_flush_vdevs(zilog); 1502 } 1503 1504 if (error || lwb == NULL) 1505 txg_wait_synced(zilog->zl_dmu_pool, 0); 1506 1507 mutex_enter(&zilog->zl_lock); 1508 1509 /* 1510 * Remember the highest committed log sequence number for ztest. 1511 * We only update this value when all the log writes succeeded, 1512 * because ztest wants to ASSERT that it got the whole log chain. 1513 */ 1514 if (error == 0 && lwb != NULL) 1515 zilog->zl_commit_lr_seq = zilog->zl_lr_seq; 1516 } 1517 1518 /* 1519 * Commit zfs transactions to stable storage. 1520 * If foid is 0 push out all transactions, otherwise push only those 1521 * for that object or might reference that object. 1522 * 1523 * itxs are committed in batches. In a heavily stressed zil there will be 1524 * a commit writer thread who is writing out a bunch of itxs to the log 1525 * for a set of committing threads (cthreads) in the same batch as the writer. 1526 * Those cthreads are all waiting on the same cv for that batch. 1527 * 1528 * There will also be a different and growing batch of threads that are 1529 * waiting to commit (qthreads). When the committing batch completes 1530 * a transition occurs such that the cthreads exit and the qthreads become 1531 * cthreads. One of the new cthreads becomes the writer thread for the 1532 * batch. Any new threads arriving become new qthreads. 1533 * 1534 * Only 2 condition variables are needed and there's no transition 1535 * between the two cvs needed. They just flip-flop between qthreads 1536 * and cthreads. 1537 * 1538 * Using this scheme we can efficiently wakeup up only those threads 1539 * that have been committed. 1540 */ 1541 void 1542 zil_commit(zilog_t *zilog, uint64_t foid) 1543 { 1544 uint64_t mybatch; 1545 1546 if (zilog->zl_sync == ZFS_SYNC_DISABLED) 1547 return; 1548 1549 /* move the async itxs for the foid to the sync queues */ 1550 zil_async_to_sync(zilog, foid); 1551 1552 mutex_enter(&zilog->zl_lock); 1553 mybatch = zilog->zl_next_batch; 1554 while (zilog->zl_writer) { 1555 cv_wait(&zilog->zl_cv_batch[mybatch & 1], &zilog->zl_lock); 1556 if (mybatch <= zilog->zl_com_batch) { 1557 mutex_exit(&zilog->zl_lock); 1558 return; 1559 } 1560 } 1561 1562 zilog->zl_next_batch++; 1563 zilog->zl_writer = B_TRUE; 1564 zil_commit_writer(zilog); 1565 zilog->zl_com_batch = mybatch; 1566 zilog->zl_writer = B_FALSE; 1567 mutex_exit(&zilog->zl_lock); 1568 1569 /* wake up one thread to become the next writer */ 1570 cv_signal(&zilog->zl_cv_batch[(mybatch+1) & 1]); 1571 1572 /* wake up all threads waiting for this batch to be committed */ 1573 cv_broadcast(&zilog->zl_cv_batch[mybatch & 1]); 1574 } 1575 1576 /* 1577 * Called in syncing context to free committed log blocks and update log header. 1578 */ 1579 void 1580 zil_sync(zilog_t *zilog, dmu_tx_t *tx) 1581 { 1582 zil_header_t *zh = zil_header_in_syncing_context(zilog); 1583 uint64_t txg = dmu_tx_get_txg(tx); 1584 spa_t *spa = zilog->zl_spa; 1585 uint64_t *replayed_seq = &zilog->zl_replayed_seq[txg & TXG_MASK]; 1586 lwb_t *lwb; 1587 1588 /* 1589 * We don't zero out zl_destroy_txg, so make sure we don't try 1590 * to destroy it twice. 1591 */ 1592 if (spa_sync_pass(spa) != 1) 1593 return; 1594 1595 mutex_enter(&zilog->zl_lock); 1596 1597 ASSERT(zilog->zl_stop_sync == 0); 1598 1599 if (*replayed_seq != 0) { 1600 ASSERT(zh->zh_replay_seq < *replayed_seq); 1601 zh->zh_replay_seq = *replayed_seq; 1602 *replayed_seq = 0; 1603 } 1604 1605 if (zilog->zl_destroy_txg == txg) { 1606 blkptr_t blk = zh->zh_log; 1607 1608 ASSERT(list_head(&zilog->zl_lwb_list) == NULL); 1609 1610 bzero(zh, sizeof (zil_header_t)); 1611 bzero(zilog->zl_replayed_seq, sizeof (zilog->zl_replayed_seq)); 1612 1613 if (zilog->zl_keep_first) { 1614 /* 1615 * If this block was part of log chain that couldn't 1616 * be claimed because a device was missing during 1617 * zil_claim(), but that device later returns, 1618 * then this block could erroneously appear valid. 1619 * To guard against this, assign a new GUID to the new 1620 * log chain so it doesn't matter what blk points to. 1621 */ 1622 zil_init_log_chain(zilog, &blk); 1623 zh->zh_log = blk; 1624 } 1625 } 1626 1627 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { 1628 zh->zh_log = lwb->lwb_blk; 1629 if (lwb->lwb_buf != NULL || lwb->lwb_max_txg > txg) 1630 break; 1631 list_remove(&zilog->zl_lwb_list, lwb); 1632 zio_free_zil(spa, txg, &lwb->lwb_blk); 1633 kmem_cache_free(zil_lwb_cache, lwb); 1634 1635 /* 1636 * If we don't have anything left in the lwb list then 1637 * we've had an allocation failure and we need to zero 1638 * out the zil_header blkptr so that we don't end 1639 * up freeing the same block twice. 1640 */ 1641 if (list_head(&zilog->zl_lwb_list) == NULL) 1642 BP_ZERO(&zh->zh_log); 1643 } 1644 mutex_exit(&zilog->zl_lock); 1645 } 1646 1647 void 1648 zil_init(void) 1649 { 1650 zil_lwb_cache = kmem_cache_create("zil_lwb_cache", 1651 sizeof (struct lwb), 0, NULL, NULL, NULL, NULL, NULL, 0); 1652 } 1653 1654 void 1655 zil_fini(void) 1656 { 1657 kmem_cache_destroy(zil_lwb_cache); 1658 } 1659 1660 void 1661 zil_set_sync(zilog_t *zilog, uint64_t sync) 1662 { 1663 zilog->zl_sync = sync; 1664 } 1665 1666 void 1667 zil_set_logbias(zilog_t *zilog, uint64_t logbias) 1668 { 1669 zilog->zl_logbias = logbias; 1670 } 1671 1672 zilog_t * 1673 zil_alloc(objset_t *os, zil_header_t *zh_phys) 1674 { 1675 zilog_t *zilog; 1676 1677 zilog = kmem_zalloc(sizeof (zilog_t), KM_SLEEP); 1678 1679 zilog->zl_header = zh_phys; 1680 zilog->zl_os = os; 1681 zilog->zl_spa = dmu_objset_spa(os); 1682 zilog->zl_dmu_pool = dmu_objset_pool(os); 1683 zilog->zl_destroy_txg = TXG_INITIAL - 1; 1684 zilog->zl_logbias = dmu_objset_logbias(os); 1685 zilog->zl_sync = dmu_objset_syncprop(os); 1686 zilog->zl_next_batch = 1; 1687 1688 mutex_init(&zilog->zl_lock, NULL, MUTEX_DEFAULT, NULL); 1689 1690 for (int i = 0; i < TXG_SIZE; i++) { 1691 mutex_init(&zilog->zl_itxg[i].itxg_lock, NULL, 1692 MUTEX_DEFAULT, NULL); 1693 } 1694 1695 list_create(&zilog->zl_lwb_list, sizeof (lwb_t), 1696 offsetof(lwb_t, lwb_node)); 1697 1698 list_create(&zilog->zl_itx_commit_list, sizeof (itx_t), 1699 offsetof(itx_t, itx_node)); 1700 1701 mutex_init(&zilog->zl_vdev_lock, NULL, MUTEX_DEFAULT, NULL); 1702 1703 avl_create(&zilog->zl_vdev_tree, zil_vdev_compare, 1704 sizeof (zil_vdev_node_t), offsetof(zil_vdev_node_t, zv_node)); 1705 1706 cv_init(&zilog->zl_cv_writer, NULL, CV_DEFAULT, NULL); 1707 cv_init(&zilog->zl_cv_suspend, NULL, CV_DEFAULT, NULL); 1708 cv_init(&zilog->zl_cv_batch[0], NULL, CV_DEFAULT, NULL); 1709 cv_init(&zilog->zl_cv_batch[1], NULL, CV_DEFAULT, NULL); 1710 1711 return (zilog); 1712 } 1713 1714 void 1715 zil_free(zilog_t *zilog) 1716 { 1717 zilog->zl_stop_sync = 1; 1718 1719 ASSERT0(zilog->zl_suspend); 1720 ASSERT0(zilog->zl_suspending); 1721 1722 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 1723 list_destroy(&zilog->zl_lwb_list); 1724 1725 avl_destroy(&zilog->zl_vdev_tree); 1726 mutex_destroy(&zilog->zl_vdev_lock); 1727 1728 ASSERT(list_is_empty(&zilog->zl_itx_commit_list)); 1729 list_destroy(&zilog->zl_itx_commit_list); 1730 1731 for (int i = 0; i < TXG_SIZE; i++) { 1732 /* 1733 * It's possible for an itx to be generated that doesn't dirty 1734 * a txg (e.g. ztest TX_TRUNCATE). So there's no zil_clean() 1735 * callback to remove the entry. We remove those here. 1736 * 1737 * Also free up the ziltest itxs. 1738 */ 1739 if (zilog->zl_itxg[i].itxg_itxs) 1740 zil_itxg_clean(zilog->zl_itxg[i].itxg_itxs); 1741 mutex_destroy(&zilog->zl_itxg[i].itxg_lock); 1742 } 1743 1744 mutex_destroy(&zilog->zl_lock); 1745 1746 cv_destroy(&zilog->zl_cv_writer); 1747 cv_destroy(&zilog->zl_cv_suspend); 1748 cv_destroy(&zilog->zl_cv_batch[0]); 1749 cv_destroy(&zilog->zl_cv_batch[1]); 1750 1751 kmem_free(zilog, sizeof (zilog_t)); 1752 } 1753 1754 /* 1755 * Open an intent log. 1756 */ 1757 zilog_t * 1758 zil_open(objset_t *os, zil_get_data_t *get_data) 1759 { 1760 zilog_t *zilog = dmu_objset_zil(os); 1761 1762 ASSERT(zilog->zl_clean_taskq == NULL); 1763 ASSERT(zilog->zl_get_data == NULL); 1764 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 1765 1766 zilog->zl_get_data = get_data; 1767 zilog->zl_clean_taskq = taskq_create("zil_clean", 1, minclsyspri, 1768 2, 2, TASKQ_PREPOPULATE); 1769 1770 return (zilog); 1771 } 1772 1773 /* 1774 * Close an intent log. 1775 */ 1776 void 1777 zil_close(zilog_t *zilog) 1778 { 1779 lwb_t *lwb; 1780 uint64_t txg = 0; 1781 1782 zil_commit(zilog, 0); /* commit all itx */ 1783 1784 /* 1785 * The lwb_max_txg for the stubby lwb will reflect the last activity 1786 * for the zil. After a txg_wait_synced() on the txg we know all the 1787 * callbacks have occurred that may clean the zil. Only then can we 1788 * destroy the zl_clean_taskq. 1789 */ 1790 mutex_enter(&zilog->zl_lock); 1791 lwb = list_tail(&zilog->zl_lwb_list); 1792 if (lwb != NULL) 1793 txg = lwb->lwb_max_txg; 1794 mutex_exit(&zilog->zl_lock); 1795 if (txg) 1796 txg_wait_synced(zilog->zl_dmu_pool, txg); 1797 ASSERT(!zilog_is_dirty(zilog)); 1798 1799 taskq_destroy(zilog->zl_clean_taskq); 1800 zilog->zl_clean_taskq = NULL; 1801 zilog->zl_get_data = NULL; 1802 1803 /* 1804 * We should have only one LWB left on the list; remove it now. 1805 */ 1806 mutex_enter(&zilog->zl_lock); 1807 lwb = list_head(&zilog->zl_lwb_list); 1808 if (lwb != NULL) { 1809 ASSERT(lwb == list_tail(&zilog->zl_lwb_list)); 1810 list_remove(&zilog->zl_lwb_list, lwb); 1811 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 1812 kmem_cache_free(zil_lwb_cache, lwb); 1813 } 1814 mutex_exit(&zilog->zl_lock); 1815 } 1816 1817 static char *suspend_tag = "zil suspending"; 1818 1819 /* 1820 * Suspend an intent log. While in suspended mode, we still honor 1821 * synchronous semantics, but we rely on txg_wait_synced() to do it. 1822 * On old version pools, we suspend the log briefly when taking a 1823 * snapshot so that it will have an empty intent log. 1824 * 1825 * Long holds are not really intended to be used the way we do here -- 1826 * held for such a short time. A concurrent caller of dsl_dataset_long_held() 1827 * could fail. Therefore we take pains to only put a long hold if it is 1828 * actually necessary. Fortunately, it will only be necessary if the 1829 * objset is currently mounted (or the ZVOL equivalent). In that case it 1830 * will already have a long hold, so we are not really making things any worse. 1831 * 1832 * Ideally, we would locate the existing long-holder (i.e. the zfsvfs_t or 1833 * zvol_state_t), and use their mechanism to prevent their hold from being 1834 * dropped (e.g. VFS_HOLD()). However, that would be even more pain for 1835 * very little gain. 1836 * 1837 * if cookiep == NULL, this does both the suspend & resume. 1838 * Otherwise, it returns with the dataset "long held", and the cookie 1839 * should be passed into zil_resume(). 1840 */ 1841 int 1842 zil_suspend(const char *osname, void **cookiep) 1843 { 1844 objset_t *os; 1845 zilog_t *zilog; 1846 const zil_header_t *zh; 1847 int error; 1848 1849 error = dmu_objset_hold(osname, suspend_tag, &os); 1850 if (error != 0) 1851 return (error); 1852 zilog = dmu_objset_zil(os); 1853 1854 mutex_enter(&zilog->zl_lock); 1855 zh = zilog->zl_header; 1856 1857 if (zh->zh_flags & ZIL_REPLAY_NEEDED) { /* unplayed log */ 1858 mutex_exit(&zilog->zl_lock); 1859 dmu_objset_rele(os, suspend_tag); 1860 return (SET_ERROR(EBUSY)); 1861 } 1862 1863 /* 1864 * Don't put a long hold in the cases where we can avoid it. This 1865 * is when there is no cookie so we are doing a suspend & resume 1866 * (i.e. called from zil_vdev_offline()), and there's nothing to do 1867 * for the suspend because it's already suspended, or there's no ZIL. 1868 */ 1869 if (cookiep == NULL && !zilog->zl_suspending && 1870 (zilog->zl_suspend > 0 || BP_IS_HOLE(&zh->zh_log))) { 1871 mutex_exit(&zilog->zl_lock); 1872 dmu_objset_rele(os, suspend_tag); 1873 return (0); 1874 } 1875 1876 dsl_dataset_long_hold(dmu_objset_ds(os), suspend_tag); 1877 dsl_pool_rele(dmu_objset_pool(os), suspend_tag); 1878 1879 zilog->zl_suspend++; 1880 1881 if (zilog->zl_suspend > 1) { 1882 /* 1883 * Someone else is already suspending it. 1884 * Just wait for them to finish. 1885 */ 1886 1887 while (zilog->zl_suspending) 1888 cv_wait(&zilog->zl_cv_suspend, &zilog->zl_lock); 1889 mutex_exit(&zilog->zl_lock); 1890 1891 if (cookiep == NULL) 1892 zil_resume(os); 1893 else 1894 *cookiep = os; 1895 return (0); 1896 } 1897 1898 /* 1899 * If there is no pointer to an on-disk block, this ZIL must not 1900 * be active (e.g. filesystem not mounted), so there's nothing 1901 * to clean up. 1902 */ 1903 if (BP_IS_HOLE(&zh->zh_log)) { 1904 ASSERT(cookiep != NULL); /* fast path already handled */ 1905 1906 *cookiep = os; 1907 mutex_exit(&zilog->zl_lock); 1908 return (0); 1909 } 1910 1911 zilog->zl_suspending = B_TRUE; 1912 mutex_exit(&zilog->zl_lock); 1913 1914 zil_commit(zilog, 0); 1915 1916 zil_destroy(zilog, B_FALSE); 1917 1918 mutex_enter(&zilog->zl_lock); 1919 zilog->zl_suspending = B_FALSE; 1920 cv_broadcast(&zilog->zl_cv_suspend); 1921 mutex_exit(&zilog->zl_lock); 1922 1923 if (cookiep == NULL) 1924 zil_resume(os); 1925 else 1926 *cookiep = os; 1927 return (0); 1928 } 1929 1930 void 1931 zil_resume(void *cookie) 1932 { 1933 objset_t *os = cookie; 1934 zilog_t *zilog = dmu_objset_zil(os); 1935 1936 mutex_enter(&zilog->zl_lock); 1937 ASSERT(zilog->zl_suspend != 0); 1938 zilog->zl_suspend--; 1939 mutex_exit(&zilog->zl_lock); 1940 dsl_dataset_long_rele(dmu_objset_ds(os), suspend_tag); 1941 dsl_dataset_rele(dmu_objset_ds(os), suspend_tag); 1942 } 1943 1944 typedef struct zil_replay_arg { 1945 zil_replay_func_t **zr_replay; 1946 void *zr_arg; 1947 boolean_t zr_byteswap; 1948 char *zr_lr; 1949 } zil_replay_arg_t; 1950 1951 static int 1952 zil_replay_error(zilog_t *zilog, lr_t *lr, int error) 1953 { 1954 char name[MAXNAMELEN]; 1955 1956 zilog->zl_replaying_seq--; /* didn't actually replay this one */ 1957 1958 dmu_objset_name(zilog->zl_os, name); 1959 1960 cmn_err(CE_WARN, "ZFS replay transaction error %d, " 1961 "dataset %s, seq 0x%llx, txtype %llu %s\n", error, name, 1962 (u_longlong_t)lr->lrc_seq, 1963 (u_longlong_t)(lr->lrc_txtype & ~TX_CI), 1964 (lr->lrc_txtype & TX_CI) ? "CI" : ""); 1965 1966 return (error); 1967 } 1968 1969 static int 1970 zil_replay_log_record(zilog_t *zilog, lr_t *lr, void *zra, uint64_t claim_txg) 1971 { 1972 zil_replay_arg_t *zr = zra; 1973 const zil_header_t *zh = zilog->zl_header; 1974 uint64_t reclen = lr->lrc_reclen; 1975 uint64_t txtype = lr->lrc_txtype; 1976 int error = 0; 1977 1978 zilog->zl_replaying_seq = lr->lrc_seq; 1979 1980 if (lr->lrc_seq <= zh->zh_replay_seq) /* already replayed */ 1981 return (0); 1982 1983 if (lr->lrc_txg < claim_txg) /* already committed */ 1984 return (0); 1985 1986 /* Strip case-insensitive bit, still present in log record */ 1987 txtype &= ~TX_CI; 1988 1989 if (txtype == 0 || txtype >= TX_MAX_TYPE) 1990 return (zil_replay_error(zilog, lr, EINVAL)); 1991 1992 /* 1993 * If this record type can be logged out of order, the object 1994 * (lr_foid) may no longer exist. That's legitimate, not an error. 1995 */ 1996 if (TX_OOO(txtype)) { 1997 error = dmu_object_info(zilog->zl_os, 1998 ((lr_ooo_t *)lr)->lr_foid, NULL); 1999 if (error == ENOENT || error == EEXIST) 2000 return (0); 2001 } 2002 2003 /* 2004 * Make a copy of the data so we can revise and extend it. 2005 */ 2006 bcopy(lr, zr->zr_lr, reclen); 2007 2008 /* 2009 * If this is a TX_WRITE with a blkptr, suck in the data. 2010 */ 2011 if (txtype == TX_WRITE && reclen == sizeof (lr_write_t)) { 2012 error = zil_read_log_data(zilog, (lr_write_t *)lr, 2013 zr->zr_lr + reclen); 2014 if (error != 0) 2015 return (zil_replay_error(zilog, lr, error)); 2016 } 2017 2018 /* 2019 * The log block containing this lr may have been byteswapped 2020 * so that we can easily examine common fields like lrc_txtype. 2021 * However, the log is a mix of different record types, and only the 2022 * replay vectors know how to byteswap their records. Therefore, if 2023 * the lr was byteswapped, undo it before invoking the replay vector. 2024 */ 2025 if (zr->zr_byteswap) 2026 byteswap_uint64_array(zr->zr_lr, reclen); 2027 2028 /* 2029 * We must now do two things atomically: replay this log record, 2030 * and update the log header sequence number to reflect the fact that 2031 * we did so. At the end of each replay function the sequence number 2032 * is updated if we are in replay mode. 2033 */ 2034 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, zr->zr_byteswap); 2035 if (error != 0) { 2036 /* 2037 * The DMU's dnode layer doesn't see removes until the txg 2038 * commits, so a subsequent claim can spuriously fail with 2039 * EEXIST. So if we receive any error we try syncing out 2040 * any removes then retry the transaction. Note that we 2041 * specify B_FALSE for byteswap now, so we don't do it twice. 2042 */ 2043 txg_wait_synced(spa_get_dsl(zilog->zl_spa), 0); 2044 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, B_FALSE); 2045 if (error != 0) 2046 return (zil_replay_error(zilog, lr, error)); 2047 } 2048 return (0); 2049 } 2050 2051 /* ARGSUSED */ 2052 static int 2053 zil_incr_blks(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg) 2054 { 2055 zilog->zl_replay_blks++; 2056 2057 return (0); 2058 } 2059 2060 /* 2061 * If this dataset has a non-empty intent log, replay it and destroy it. 2062 */ 2063 void 2064 zil_replay(objset_t *os, void *arg, zil_replay_func_t *replay_func[TX_MAX_TYPE]) 2065 { 2066 zilog_t *zilog = dmu_objset_zil(os); 2067 const zil_header_t *zh = zilog->zl_header; 2068 zil_replay_arg_t zr; 2069 2070 if ((zh->zh_flags & ZIL_REPLAY_NEEDED) == 0) { 2071 zil_destroy(zilog, B_TRUE); 2072 return; 2073 } 2074 2075 zr.zr_replay = replay_func; 2076 zr.zr_arg = arg; 2077 zr.zr_byteswap = BP_SHOULD_BYTESWAP(&zh->zh_log); 2078 zr.zr_lr = kmem_alloc(2 * SPA_MAXBLOCKSIZE, KM_SLEEP); 2079 2080 /* 2081 * Wait for in-progress removes to sync before starting replay. 2082 */ 2083 txg_wait_synced(zilog->zl_dmu_pool, 0); 2084 2085 zilog->zl_replay = B_TRUE; 2086 zilog->zl_replay_time = ddi_get_lbolt(); 2087 ASSERT(zilog->zl_replay_blks == 0); 2088 (void) zil_parse(zilog, zil_incr_blks, zil_replay_log_record, &zr, 2089 zh->zh_claim_txg); 2090 kmem_free(zr.zr_lr, 2 * SPA_MAXBLOCKSIZE); 2091 2092 zil_destroy(zilog, B_FALSE); 2093 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 2094 zilog->zl_replay = B_FALSE; 2095 } 2096 2097 boolean_t 2098 zil_replaying(zilog_t *zilog, dmu_tx_t *tx) 2099 { 2100 if (zilog->zl_sync == ZFS_SYNC_DISABLED) 2101 return (B_TRUE); 2102 2103 if (zilog->zl_replay) { 2104 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 2105 zilog->zl_replayed_seq[dmu_tx_get_txg(tx) & TXG_MASK] = 2106 zilog->zl_replaying_seq; 2107 return (B_TRUE); 2108 } 2109 2110 return (B_FALSE); 2111 } 2112 2113 /* ARGSUSED */ 2114 int 2115 zil_vdev_offline(const char *osname, void *arg) 2116 { 2117 int error; 2118 2119 error = zil_suspend(osname, NULL); 2120 if (error != 0) 2121 return (SET_ERROR(EEXIST)); 2122 return (0); 2123 }