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 https://opensource.org/licenses/CDDL-1.0. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2011, 2018 by Delphix. All rights reserved. 24 * Copyright (c) 2014 Integros [integros.com] 25 * Copyright (c) 2018 Datto Inc. 26 */ 27 28 /* Portions Copyright 2010 Robert Milkowski */ 29 30 #include <sys/zfs_context.h> 31 #include <sys/spa.h> 32 #include <sys/spa_impl.h> 33 #include <sys/dmu.h> 34 #include <sys/zap.h> 35 #include <sys/arc.h> 36 #include <sys/stat.h> 37 #include <sys/zil.h> 38 #include <sys/zil_impl.h> 39 #include <sys/dsl_dataset.h> 40 #include <sys/vdev_impl.h> 41 #include <sys/dmu_tx.h> 42 #include <sys/dsl_pool.h> 43 #include <sys/metaslab.h> 44 #include <sys/trace_zfs.h> 45 #include <sys/abd.h> 46 #include <sys/brt.h> 47 #include <sys/wmsum.h> 48 49 /* 50 * The ZFS Intent Log (ZIL) saves "transaction records" (itxs) of system 51 * calls that change the file system. Each itx has enough information to 52 * be able to replay them after a system crash, power loss, or 53 * equivalent failure mode. These are stored in memory until either: 54 * 55 * 1. they are committed to the pool by the DMU transaction group 56 * (txg), at which point they can be discarded; or 57 * 2. they are committed to the on-disk ZIL for the dataset being 58 * modified (e.g. due to an fsync, O_DSYNC, or other synchronous 59 * requirement). 60 * 61 * In the event of a crash or power loss, the itxs contained by each 62 * dataset's on-disk ZIL will be replayed when that dataset is first 63 * instantiated (e.g. if the dataset is a normal filesystem, when it is 64 * first mounted). 65 * 66 * As hinted at above, there is one ZIL per dataset (both the in-memory 67 * representation, and the on-disk representation). The on-disk format 68 * consists of 3 parts: 69 * 70 * - a single, per-dataset, ZIL header; which points to a chain of 71 * - zero or more ZIL blocks; each of which contains 72 * - zero or more ZIL records 73 * 74 * A ZIL record holds the information necessary to replay a single 75 * system call transaction. A ZIL block can hold many ZIL records, and 76 * the blocks are chained together, similarly to a singly linked list. 77 * 78 * Each ZIL block contains a block pointer (blkptr_t) to the next ZIL 79 * block in the chain, and the ZIL header points to the first block in 80 * the chain. 81 * 82 * Note, there is not a fixed place in the pool to hold these ZIL 83 * blocks; they are dynamically allocated and freed as needed from the 84 * blocks available on the pool, though they can be preferentially 85 * allocated from a dedicated "log" vdev. 86 */ 87 88 /* 89 * This controls the amount of time that a ZIL block (lwb) will remain 90 * "open" when it isn't "full", and it has a thread waiting for it to be 91 * committed to stable storage. Please refer to the zil_commit_waiter() 92 * function (and the comments within it) for more details. 93 */ 94 static uint_t zfs_commit_timeout_pct = 5; 95 96 /* 97 * Minimal time we care to delay commit waiting for more ZIL records. 98 * At least FreeBSD kernel can't sleep for less than 2us at its best. 99 * So requests to sleep for less then 5us is a waste of CPU time with 100 * a risk of significant log latency increase due to oversleep. 101 */ 102 static uint64_t zil_min_commit_timeout = 5000; 103 104 /* 105 * See zil.h for more information about these fields. 106 */ 107 static zil_kstat_values_t zil_stats = { 108 { "zil_commit_count", KSTAT_DATA_UINT64 }, 109 { "zil_commit_writer_count", KSTAT_DATA_UINT64 }, 110 { "zil_itx_count", KSTAT_DATA_UINT64 }, 111 { "zil_itx_indirect_count", KSTAT_DATA_UINT64 }, 112 { "zil_itx_indirect_bytes", KSTAT_DATA_UINT64 }, 113 { "zil_itx_copied_count", KSTAT_DATA_UINT64 }, 114 { "zil_itx_copied_bytes", KSTAT_DATA_UINT64 }, 115 { "zil_itx_needcopy_count", KSTAT_DATA_UINT64 }, 116 { "zil_itx_needcopy_bytes", KSTAT_DATA_UINT64 }, 117 { "zil_itx_metaslab_normal_count", KSTAT_DATA_UINT64 }, 118 { "zil_itx_metaslab_normal_bytes", KSTAT_DATA_UINT64 }, 119 { "zil_itx_metaslab_normal_write", KSTAT_DATA_UINT64 }, 120 { "zil_itx_metaslab_normal_alloc", KSTAT_DATA_UINT64 }, 121 { "zil_itx_metaslab_slog_count", KSTAT_DATA_UINT64 }, 122 { "zil_itx_metaslab_slog_bytes", KSTAT_DATA_UINT64 }, 123 { "zil_itx_metaslab_slog_write", KSTAT_DATA_UINT64 }, 124 { "zil_itx_metaslab_slog_alloc", KSTAT_DATA_UINT64 }, 125 }; 126 127 static zil_sums_t zil_sums_global; 128 static kstat_t *zil_kstats_global; 129 130 /* 131 * Disable intent logging replay. This global ZIL switch affects all pools. 132 */ 133 int zil_replay_disable = 0; 134 135 /* 136 * Disable the DKIOCFLUSHWRITECACHE commands that are normally sent to 137 * the disk(s) by the ZIL after an LWB write has completed. Setting this 138 * will cause ZIL corruption on power loss if a volatile out-of-order 139 * write cache is enabled. 140 */ 141 static int zil_nocacheflush = 0; 142 143 /* 144 * Limit SLOG write size per commit executed with synchronous priority. 145 * Any writes above that will be executed with lower (asynchronous) priority 146 * to limit potential SLOG device abuse by single active ZIL writer. 147 */ 148 static uint64_t zil_slog_bulk = 768 * 1024; 149 150 static kmem_cache_t *zil_lwb_cache; 151 static kmem_cache_t *zil_zcw_cache; 152 153 static void zil_lwb_commit(zilog_t *zilog, lwb_t *lwb, itx_t *itx); 154 static itx_t *zil_itx_clone(itx_t *oitx); 155 156 static int 157 zil_bp_compare(const void *x1, const void *x2) 158 { 159 const dva_t *dva1 = &((zil_bp_node_t *)x1)->zn_dva; 160 const dva_t *dva2 = &((zil_bp_node_t *)x2)->zn_dva; 161 162 int cmp = TREE_CMP(DVA_GET_VDEV(dva1), DVA_GET_VDEV(dva2)); 163 if (likely(cmp)) 164 return (cmp); 165 166 return (TREE_CMP(DVA_GET_OFFSET(dva1), DVA_GET_OFFSET(dva2))); 167 } 168 169 static void 170 zil_bp_tree_init(zilog_t *zilog) 171 { 172 avl_create(&zilog->zl_bp_tree, zil_bp_compare, 173 sizeof (zil_bp_node_t), offsetof(zil_bp_node_t, zn_node)); 174 } 175 176 static void 177 zil_bp_tree_fini(zilog_t *zilog) 178 { 179 avl_tree_t *t = &zilog->zl_bp_tree; 180 zil_bp_node_t *zn; 181 void *cookie = NULL; 182 183 while ((zn = avl_destroy_nodes(t, &cookie)) != NULL) 184 kmem_free(zn, sizeof (zil_bp_node_t)); 185 186 avl_destroy(t); 187 } 188 189 int 190 zil_bp_tree_add(zilog_t *zilog, const blkptr_t *bp) 191 { 192 avl_tree_t *t = &zilog->zl_bp_tree; 193 const dva_t *dva; 194 zil_bp_node_t *zn; 195 avl_index_t where; 196 197 if (BP_IS_EMBEDDED(bp)) 198 return (0); 199 200 dva = BP_IDENTITY(bp); 201 202 if (avl_find(t, dva, &where) != NULL) 203 return (SET_ERROR(EEXIST)); 204 205 zn = kmem_alloc(sizeof (zil_bp_node_t), KM_SLEEP); 206 zn->zn_dva = *dva; 207 avl_insert(t, zn, where); 208 209 return (0); 210 } 211 212 static zil_header_t * 213 zil_header_in_syncing_context(zilog_t *zilog) 214 { 215 return ((zil_header_t *)zilog->zl_header); 216 } 217 218 static void 219 zil_init_log_chain(zilog_t *zilog, blkptr_t *bp) 220 { 221 zio_cksum_t *zc = &bp->blk_cksum; 222 223 (void) random_get_pseudo_bytes((void *)&zc->zc_word[ZIL_ZC_GUID_0], 224 sizeof (zc->zc_word[ZIL_ZC_GUID_0])); 225 (void) random_get_pseudo_bytes((void *)&zc->zc_word[ZIL_ZC_GUID_1], 226 sizeof (zc->zc_word[ZIL_ZC_GUID_1])); 227 zc->zc_word[ZIL_ZC_OBJSET] = dmu_objset_id(zilog->zl_os); 228 zc->zc_word[ZIL_ZC_SEQ] = 1ULL; 229 } 230 231 static int 232 zil_kstats_global_update(kstat_t *ksp, int rw) 233 { 234 zil_kstat_values_t *zs = ksp->ks_data; 235 ASSERT3P(&zil_stats, ==, zs); 236 237 if (rw == KSTAT_WRITE) { 238 return (SET_ERROR(EACCES)); 239 } 240 241 zil_kstat_values_update(zs, &zil_sums_global); 242 243 return (0); 244 } 245 246 /* 247 * Read a log block and make sure it's valid. 248 */ 249 static int 250 zil_read_log_block(zilog_t *zilog, boolean_t decrypt, const blkptr_t *bp, 251 blkptr_t *nbp, char **begin, char **end, arc_buf_t **abuf) 252 { 253 zio_flag_t zio_flags = ZIO_FLAG_CANFAIL; 254 arc_flags_t aflags = ARC_FLAG_WAIT; 255 zbookmark_phys_t zb; 256 int error; 257 258 if (zilog->zl_header->zh_claim_txg == 0) 259 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; 260 261 if (!(zilog->zl_header->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) 262 zio_flags |= ZIO_FLAG_SPECULATIVE; 263 264 if (!decrypt) 265 zio_flags |= ZIO_FLAG_RAW; 266 267 SET_BOOKMARK(&zb, bp->blk_cksum.zc_word[ZIL_ZC_OBJSET], 268 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]); 269 270 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, 271 abuf, ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); 272 273 if (error == 0) { 274 zio_cksum_t cksum = bp->blk_cksum; 275 276 /* 277 * Validate the checksummed log block. 278 * 279 * Sequence numbers should be... sequential. The checksum 280 * verifier for the next block should be bp's checksum plus 1. 281 * 282 * Also check the log chain linkage and size used. 283 */ 284 cksum.zc_word[ZIL_ZC_SEQ]++; 285 286 uint64_t size = BP_GET_LSIZE(bp); 287 if (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2) { 288 zil_chain_t *zilc = (*abuf)->b_data; 289 char *lr = (char *)(zilc + 1); 290 291 if (memcmp(&cksum, &zilc->zc_next_blk.blk_cksum, 292 sizeof (cksum)) || 293 zilc->zc_nused < sizeof (*zilc) || 294 zilc->zc_nused > size) { 295 error = SET_ERROR(ECKSUM); 296 } else { 297 *begin = lr; 298 *end = lr + zilc->zc_nused - sizeof (*zilc); 299 *nbp = zilc->zc_next_blk; 300 } 301 } else { 302 char *lr = (*abuf)->b_data; 303 zil_chain_t *zilc = (zil_chain_t *)(lr + size) - 1; 304 305 if (memcmp(&cksum, &zilc->zc_next_blk.blk_cksum, 306 sizeof (cksum)) || 307 (zilc->zc_nused > (size - sizeof (*zilc)))) { 308 error = SET_ERROR(ECKSUM); 309 } else { 310 *begin = lr; 311 *end = lr + zilc->zc_nused; 312 *nbp = zilc->zc_next_blk; 313 } 314 } 315 } 316 317 return (error); 318 } 319 320 /* 321 * Read a TX_WRITE log data block. 322 */ 323 static int 324 zil_read_log_data(zilog_t *zilog, const lr_write_t *lr, void *wbuf) 325 { 326 zio_flag_t zio_flags = ZIO_FLAG_CANFAIL; 327 const blkptr_t *bp = &lr->lr_blkptr; 328 arc_flags_t aflags = ARC_FLAG_WAIT; 329 arc_buf_t *abuf = NULL; 330 zbookmark_phys_t zb; 331 int error; 332 333 if (BP_IS_HOLE(bp)) { 334 if (wbuf != NULL) 335 memset(wbuf, 0, MAX(BP_GET_LSIZE(bp), lr->lr_length)); 336 return (0); 337 } 338 339 if (zilog->zl_header->zh_claim_txg == 0) 340 zio_flags |= ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB; 341 342 /* 343 * If we are not using the resulting data, we are just checking that 344 * it hasn't been corrupted so we don't need to waste CPU time 345 * decompressing and decrypting it. 346 */ 347 if (wbuf == NULL) 348 zio_flags |= ZIO_FLAG_RAW; 349 350 ASSERT3U(BP_GET_LSIZE(bp), !=, 0); 351 SET_BOOKMARK(&zb, dmu_objset_id(zilog->zl_os), lr->lr_foid, 352 ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp)); 353 354 error = arc_read(NULL, zilog->zl_spa, bp, arc_getbuf_func, &abuf, 355 ZIO_PRIORITY_SYNC_READ, zio_flags, &aflags, &zb); 356 357 if (error == 0) { 358 if (wbuf != NULL) 359 memcpy(wbuf, abuf->b_data, arc_buf_size(abuf)); 360 arc_buf_destroy(abuf, &abuf); 361 } 362 363 return (error); 364 } 365 366 void 367 zil_sums_init(zil_sums_t *zs) 368 { 369 wmsum_init(&zs->zil_commit_count, 0); 370 wmsum_init(&zs->zil_commit_writer_count, 0); 371 wmsum_init(&zs->zil_itx_count, 0); 372 wmsum_init(&zs->zil_itx_indirect_count, 0); 373 wmsum_init(&zs->zil_itx_indirect_bytes, 0); 374 wmsum_init(&zs->zil_itx_copied_count, 0); 375 wmsum_init(&zs->zil_itx_copied_bytes, 0); 376 wmsum_init(&zs->zil_itx_needcopy_count, 0); 377 wmsum_init(&zs->zil_itx_needcopy_bytes, 0); 378 wmsum_init(&zs->zil_itx_metaslab_normal_count, 0); 379 wmsum_init(&zs->zil_itx_metaslab_normal_bytes, 0); 380 wmsum_init(&zs->zil_itx_metaslab_normal_write, 0); 381 wmsum_init(&zs->zil_itx_metaslab_normal_alloc, 0); 382 wmsum_init(&zs->zil_itx_metaslab_slog_count, 0); 383 wmsum_init(&zs->zil_itx_metaslab_slog_bytes, 0); 384 wmsum_init(&zs->zil_itx_metaslab_slog_write, 0); 385 wmsum_init(&zs->zil_itx_metaslab_slog_alloc, 0); 386 } 387 388 void 389 zil_sums_fini(zil_sums_t *zs) 390 { 391 wmsum_fini(&zs->zil_commit_count); 392 wmsum_fini(&zs->zil_commit_writer_count); 393 wmsum_fini(&zs->zil_itx_count); 394 wmsum_fini(&zs->zil_itx_indirect_count); 395 wmsum_fini(&zs->zil_itx_indirect_bytes); 396 wmsum_fini(&zs->zil_itx_copied_count); 397 wmsum_fini(&zs->zil_itx_copied_bytes); 398 wmsum_fini(&zs->zil_itx_needcopy_count); 399 wmsum_fini(&zs->zil_itx_needcopy_bytes); 400 wmsum_fini(&zs->zil_itx_metaslab_normal_count); 401 wmsum_fini(&zs->zil_itx_metaslab_normal_bytes); 402 wmsum_fini(&zs->zil_itx_metaslab_normal_write); 403 wmsum_fini(&zs->zil_itx_metaslab_normal_alloc); 404 wmsum_fini(&zs->zil_itx_metaslab_slog_count); 405 wmsum_fini(&zs->zil_itx_metaslab_slog_bytes); 406 wmsum_fini(&zs->zil_itx_metaslab_slog_write); 407 wmsum_fini(&zs->zil_itx_metaslab_slog_alloc); 408 } 409 410 void 411 zil_kstat_values_update(zil_kstat_values_t *zs, zil_sums_t *zil_sums) 412 { 413 zs->zil_commit_count.value.ui64 = 414 wmsum_value(&zil_sums->zil_commit_count); 415 zs->zil_commit_writer_count.value.ui64 = 416 wmsum_value(&zil_sums->zil_commit_writer_count); 417 zs->zil_itx_count.value.ui64 = 418 wmsum_value(&zil_sums->zil_itx_count); 419 zs->zil_itx_indirect_count.value.ui64 = 420 wmsum_value(&zil_sums->zil_itx_indirect_count); 421 zs->zil_itx_indirect_bytes.value.ui64 = 422 wmsum_value(&zil_sums->zil_itx_indirect_bytes); 423 zs->zil_itx_copied_count.value.ui64 = 424 wmsum_value(&zil_sums->zil_itx_copied_count); 425 zs->zil_itx_copied_bytes.value.ui64 = 426 wmsum_value(&zil_sums->zil_itx_copied_bytes); 427 zs->zil_itx_needcopy_count.value.ui64 = 428 wmsum_value(&zil_sums->zil_itx_needcopy_count); 429 zs->zil_itx_needcopy_bytes.value.ui64 = 430 wmsum_value(&zil_sums->zil_itx_needcopy_bytes); 431 zs->zil_itx_metaslab_normal_count.value.ui64 = 432 wmsum_value(&zil_sums->zil_itx_metaslab_normal_count); 433 zs->zil_itx_metaslab_normal_bytes.value.ui64 = 434 wmsum_value(&zil_sums->zil_itx_metaslab_normal_bytes); 435 zs->zil_itx_metaslab_normal_write.value.ui64 = 436 wmsum_value(&zil_sums->zil_itx_metaslab_normal_write); 437 zs->zil_itx_metaslab_normal_alloc.value.ui64 = 438 wmsum_value(&zil_sums->zil_itx_metaslab_normal_alloc); 439 zs->zil_itx_metaslab_slog_count.value.ui64 = 440 wmsum_value(&zil_sums->zil_itx_metaslab_slog_count); 441 zs->zil_itx_metaslab_slog_bytes.value.ui64 = 442 wmsum_value(&zil_sums->zil_itx_metaslab_slog_bytes); 443 zs->zil_itx_metaslab_slog_write.value.ui64 = 444 wmsum_value(&zil_sums->zil_itx_metaslab_slog_write); 445 zs->zil_itx_metaslab_slog_alloc.value.ui64 = 446 wmsum_value(&zil_sums->zil_itx_metaslab_slog_alloc); 447 } 448 449 /* 450 * Parse the intent log, and call parse_func for each valid record within. 451 */ 452 int 453 zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func, 454 zil_parse_lr_func_t *parse_lr_func, void *arg, uint64_t txg, 455 boolean_t decrypt) 456 { 457 const zil_header_t *zh = zilog->zl_header; 458 boolean_t claimed = !!zh->zh_claim_txg; 459 uint64_t claim_blk_seq = claimed ? zh->zh_claim_blk_seq : UINT64_MAX; 460 uint64_t claim_lr_seq = claimed ? zh->zh_claim_lr_seq : UINT64_MAX; 461 uint64_t max_blk_seq = 0; 462 uint64_t max_lr_seq = 0; 463 uint64_t blk_count = 0; 464 uint64_t lr_count = 0; 465 blkptr_t blk, next_blk = {{{{0}}}}; 466 int error = 0; 467 468 /* 469 * Old logs didn't record the maximum zh_claim_lr_seq. 470 */ 471 if (!(zh->zh_flags & ZIL_CLAIM_LR_SEQ_VALID)) 472 claim_lr_seq = UINT64_MAX; 473 474 /* 475 * Starting at the block pointed to by zh_log we read the log chain. 476 * For each block in the chain we strongly check that block to 477 * ensure its validity. We stop when an invalid block is found. 478 * For each block pointer in the chain we call parse_blk_func(). 479 * For each record in each valid block we call parse_lr_func(). 480 * If the log has been claimed, stop if we encounter a sequence 481 * number greater than the highest claimed sequence number. 482 */ 483 zil_bp_tree_init(zilog); 484 485 for (blk = zh->zh_log; !BP_IS_HOLE(&blk); blk = next_blk) { 486 uint64_t blk_seq = blk.blk_cksum.zc_word[ZIL_ZC_SEQ]; 487 int reclen; 488 char *lrp, *end; 489 arc_buf_t *abuf = NULL; 490 491 if (blk_seq > claim_blk_seq) 492 break; 493 494 error = parse_blk_func(zilog, &blk, arg, txg); 495 if (error != 0) 496 break; 497 ASSERT3U(max_blk_seq, <, blk_seq); 498 max_blk_seq = blk_seq; 499 blk_count++; 500 501 if (max_lr_seq == claim_lr_seq && max_blk_seq == claim_blk_seq) 502 break; 503 504 error = zil_read_log_block(zilog, decrypt, &blk, &next_blk, 505 &lrp, &end, &abuf); 506 if (error != 0) { 507 if (abuf) 508 arc_buf_destroy(abuf, &abuf); 509 if (claimed) { 510 char name[ZFS_MAX_DATASET_NAME_LEN]; 511 512 dmu_objset_name(zilog->zl_os, name); 513 514 cmn_err(CE_WARN, "ZFS read log block error %d, " 515 "dataset %s, seq 0x%llx\n", error, name, 516 (u_longlong_t)blk_seq); 517 } 518 break; 519 } 520 521 for (; lrp < end; lrp += reclen) { 522 lr_t *lr = (lr_t *)lrp; 523 reclen = lr->lrc_reclen; 524 ASSERT3U(reclen, >=, sizeof (lr_t)); 525 if (lr->lrc_seq > claim_lr_seq) { 526 arc_buf_destroy(abuf, &abuf); 527 goto done; 528 } 529 530 error = parse_lr_func(zilog, lr, arg, txg); 531 if (error != 0) { 532 arc_buf_destroy(abuf, &abuf); 533 goto done; 534 } 535 ASSERT3U(max_lr_seq, <, lr->lrc_seq); 536 max_lr_seq = lr->lrc_seq; 537 lr_count++; 538 } 539 arc_buf_destroy(abuf, &abuf); 540 } 541 done: 542 zilog->zl_parse_error = error; 543 zilog->zl_parse_blk_seq = max_blk_seq; 544 zilog->zl_parse_lr_seq = max_lr_seq; 545 zilog->zl_parse_blk_count = blk_count; 546 zilog->zl_parse_lr_count = lr_count; 547 548 zil_bp_tree_fini(zilog); 549 550 return (error); 551 } 552 553 static int 554 zil_clear_log_block(zilog_t *zilog, const blkptr_t *bp, void *tx, 555 uint64_t first_txg) 556 { 557 (void) tx; 558 ASSERT(!BP_IS_HOLE(bp)); 559 560 /* 561 * As we call this function from the context of a rewind to a 562 * checkpoint, each ZIL block whose txg is later than the txg 563 * that we rewind to is invalid. Thus, we return -1 so 564 * zil_parse() doesn't attempt to read it. 565 */ 566 if (bp->blk_birth >= first_txg) 567 return (-1); 568 569 if (zil_bp_tree_add(zilog, bp) != 0) 570 return (0); 571 572 zio_free(zilog->zl_spa, first_txg, bp); 573 return (0); 574 } 575 576 static int 577 zil_noop_log_record(zilog_t *zilog, const lr_t *lrc, void *tx, 578 uint64_t first_txg) 579 { 580 (void) zilog, (void) lrc, (void) tx, (void) first_txg; 581 return (0); 582 } 583 584 static int 585 zil_claim_log_block(zilog_t *zilog, const blkptr_t *bp, void *tx, 586 uint64_t first_txg) 587 { 588 /* 589 * Claim log block if not already committed and not already claimed. 590 * If tx == NULL, just verify that the block is claimable. 591 */ 592 if (BP_IS_HOLE(bp) || bp->blk_birth < first_txg || 593 zil_bp_tree_add(zilog, bp) != 0) 594 return (0); 595 596 return (zio_wait(zio_claim(NULL, zilog->zl_spa, 597 tx == NULL ? 0 : first_txg, bp, spa_claim_notify, NULL, 598 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | ZIO_FLAG_SCRUB))); 599 } 600 601 static int 602 zil_claim_write(zilog_t *zilog, const lr_t *lrc, void *tx, uint64_t first_txg) 603 { 604 lr_write_t *lr = (lr_write_t *)lrc; 605 int error; 606 607 ASSERT(lrc->lrc_txtype == TX_WRITE); 608 609 /* 610 * If the block is not readable, don't claim it. This can happen 611 * in normal operation when a log block is written to disk before 612 * some of the dmu_sync() blocks it points to. In this case, the 613 * transaction cannot have been committed to anyone (we would have 614 * waited for all writes to be stable first), so it is semantically 615 * correct to declare this the end of the log. 616 */ 617 if (lr->lr_blkptr.blk_birth >= first_txg) { 618 error = zil_read_log_data(zilog, lr, NULL); 619 if (error != 0) 620 return (error); 621 } 622 623 return (zil_claim_log_block(zilog, &lr->lr_blkptr, tx, first_txg)); 624 } 625 626 static int 627 zil_claim_clone_range(zilog_t *zilog, const lr_t *lrc, void *tx) 628 { 629 const lr_clone_range_t *lr = (const lr_clone_range_t *)lrc; 630 const blkptr_t *bp; 631 spa_t *spa; 632 uint_t ii; 633 634 ASSERT(lrc->lrc_txtype == TX_CLONE_RANGE); 635 636 if (tx == NULL) { 637 return (0); 638 } 639 640 /* 641 * XXX: Do we need to byteswap lr? 642 */ 643 644 spa = zilog->zl_spa; 645 646 for (ii = 0; ii < lr->lr_nbps; ii++) { 647 bp = &lr->lr_bps[ii]; 648 649 /* 650 * When data in embedded into BP there is no need to create 651 * BRT entry as there is no data block. Just copy the BP as 652 * it contains the data. 653 */ 654 if (!BP_IS_HOLE(bp) && !BP_IS_EMBEDDED(bp)) { 655 brt_pending_add(spa, bp, tx); 656 } 657 } 658 659 return (0); 660 } 661 662 static int 663 zil_claim_log_record(zilog_t *zilog, const lr_t *lrc, void *tx, 664 uint64_t first_txg) 665 { 666 667 switch (lrc->lrc_txtype) { 668 case TX_WRITE: 669 return (zil_claim_write(zilog, lrc, tx, first_txg)); 670 case TX_CLONE_RANGE: 671 return (zil_claim_clone_range(zilog, lrc, tx)); 672 default: 673 return (0); 674 } 675 } 676 677 static int 678 zil_free_log_block(zilog_t *zilog, const blkptr_t *bp, void *tx, 679 uint64_t claim_txg) 680 { 681 (void) claim_txg; 682 683 zio_free(zilog->zl_spa, dmu_tx_get_txg(tx), bp); 684 685 return (0); 686 } 687 688 static int 689 zil_free_write(zilog_t *zilog, const lr_t *lrc, void *tx, uint64_t claim_txg) 690 { 691 lr_write_t *lr = (lr_write_t *)lrc; 692 blkptr_t *bp = &lr->lr_blkptr; 693 694 ASSERT(lrc->lrc_txtype == TX_WRITE); 695 696 /* 697 * If we previously claimed it, we need to free it. 698 */ 699 if (bp->blk_birth >= claim_txg && zil_bp_tree_add(zilog, bp) == 0 && 700 !BP_IS_HOLE(bp)) { 701 zio_free(zilog->zl_spa, dmu_tx_get_txg(tx), bp); 702 } 703 704 return (0); 705 } 706 707 static int 708 zil_free_clone_range(zilog_t *zilog, const lr_t *lrc, void *tx) 709 { 710 const lr_clone_range_t *lr = (const lr_clone_range_t *)lrc; 711 const blkptr_t *bp; 712 spa_t *spa; 713 uint_t ii; 714 715 ASSERT(lrc->lrc_txtype == TX_CLONE_RANGE); 716 717 if (tx == NULL) { 718 return (0); 719 } 720 721 spa = zilog->zl_spa; 722 723 for (ii = 0; ii < lr->lr_nbps; ii++) { 724 bp = &lr->lr_bps[ii]; 725 726 if (!BP_IS_HOLE(bp)) { 727 zio_free(spa, dmu_tx_get_txg(tx), bp); 728 } 729 } 730 731 return (0); 732 } 733 734 static int 735 zil_free_log_record(zilog_t *zilog, const lr_t *lrc, void *tx, 736 uint64_t claim_txg) 737 { 738 739 if (claim_txg == 0) { 740 return (0); 741 } 742 743 switch (lrc->lrc_txtype) { 744 case TX_WRITE: 745 return (zil_free_write(zilog, lrc, tx, claim_txg)); 746 case TX_CLONE_RANGE: 747 return (zil_free_clone_range(zilog, lrc, tx)); 748 default: 749 return (0); 750 } 751 } 752 753 static int 754 zil_lwb_vdev_compare(const void *x1, const void *x2) 755 { 756 const uint64_t v1 = ((zil_vdev_node_t *)x1)->zv_vdev; 757 const uint64_t v2 = ((zil_vdev_node_t *)x2)->zv_vdev; 758 759 return (TREE_CMP(v1, v2)); 760 } 761 762 /* 763 * Allocate a new lwb. We may already have a block pointer for it, in which 764 * case we get size and version from there. Or we may not yet, in which case 765 * we choose them here and later make the block allocation match. 766 */ 767 static lwb_t * 768 zil_alloc_lwb(zilog_t *zilog, int sz, blkptr_t *bp, boolean_t slog, 769 uint64_t txg, lwb_state_t state) 770 { 771 lwb_t *lwb; 772 773 lwb = kmem_cache_alloc(zil_lwb_cache, KM_SLEEP); 774 lwb->lwb_zilog = zilog; 775 if (bp) { 776 lwb->lwb_blk = *bp; 777 lwb->lwb_slim = (BP_GET_CHECKSUM(bp) == ZIO_CHECKSUM_ZILOG2); 778 sz = BP_GET_LSIZE(bp); 779 } else { 780 BP_ZERO(&lwb->lwb_blk); 781 lwb->lwb_slim = (spa_version(zilog->zl_spa) >= 782 SPA_VERSION_SLIM_ZIL); 783 } 784 lwb->lwb_slog = slog; 785 lwb->lwb_error = 0; 786 if (lwb->lwb_slim) { 787 lwb->lwb_nmax = sz; 788 lwb->lwb_nused = lwb->lwb_nfilled = sizeof (zil_chain_t); 789 } else { 790 lwb->lwb_nmax = sz - sizeof (zil_chain_t); 791 lwb->lwb_nused = lwb->lwb_nfilled = 0; 792 } 793 lwb->lwb_sz = sz; 794 lwb->lwb_state = state; 795 lwb->lwb_buf = zio_buf_alloc(sz); 796 lwb->lwb_child_zio = NULL; 797 lwb->lwb_write_zio = NULL; 798 lwb->lwb_root_zio = NULL; 799 lwb->lwb_issued_timestamp = 0; 800 lwb->lwb_issued_txg = 0; 801 lwb->lwb_alloc_txg = txg; 802 lwb->lwb_max_txg = 0; 803 804 mutex_enter(&zilog->zl_lock); 805 list_insert_tail(&zilog->zl_lwb_list, lwb); 806 if (state != LWB_STATE_NEW) 807 zilog->zl_last_lwb_opened = lwb; 808 mutex_exit(&zilog->zl_lock); 809 810 return (lwb); 811 } 812 813 static void 814 zil_free_lwb(zilog_t *zilog, lwb_t *lwb) 815 { 816 ASSERT(MUTEX_HELD(&zilog->zl_lock)); 817 ASSERT(lwb->lwb_state == LWB_STATE_NEW || 818 lwb->lwb_state == LWB_STATE_FLUSH_DONE); 819 ASSERT3P(lwb->lwb_child_zio, ==, NULL); 820 ASSERT3P(lwb->lwb_write_zio, ==, NULL); 821 ASSERT3P(lwb->lwb_root_zio, ==, NULL); 822 ASSERT3U(lwb->lwb_alloc_txg, <=, spa_syncing_txg(zilog->zl_spa)); 823 ASSERT3U(lwb->lwb_max_txg, <=, spa_syncing_txg(zilog->zl_spa)); 824 VERIFY(list_is_empty(&lwb->lwb_itxs)); 825 VERIFY(list_is_empty(&lwb->lwb_waiters)); 826 ASSERT(avl_is_empty(&lwb->lwb_vdev_tree)); 827 ASSERT(!MUTEX_HELD(&lwb->lwb_vdev_lock)); 828 829 /* 830 * Clear the zilog's field to indicate this lwb is no longer 831 * valid, and prevent use-after-free errors. 832 */ 833 if (zilog->zl_last_lwb_opened == lwb) 834 zilog->zl_last_lwb_opened = NULL; 835 836 kmem_cache_free(zil_lwb_cache, lwb); 837 } 838 839 /* 840 * Called when we create in-memory log transactions so that we know 841 * to cleanup the itxs at the end of spa_sync(). 842 */ 843 static void 844 zilog_dirty(zilog_t *zilog, uint64_t txg) 845 { 846 dsl_pool_t *dp = zilog->zl_dmu_pool; 847 dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os); 848 849 ASSERT(spa_writeable(zilog->zl_spa)); 850 851 if (ds->ds_is_snapshot) 852 panic("dirtying snapshot!"); 853 854 if (txg_list_add(&dp->dp_dirty_zilogs, zilog, txg)) { 855 /* up the hold count until we can be written out */ 856 dmu_buf_add_ref(ds->ds_dbuf, zilog); 857 858 zilog->zl_dirty_max_txg = MAX(txg, zilog->zl_dirty_max_txg); 859 } 860 } 861 862 /* 863 * Determine if the zil is dirty in the specified txg. Callers wanting to 864 * ensure that the dirty state does not change must hold the itxg_lock for 865 * the specified txg. Holding the lock will ensure that the zil cannot be 866 * dirtied (zil_itx_assign) or cleaned (zil_clean) while we check its current 867 * state. 868 */ 869 static boolean_t __maybe_unused 870 zilog_is_dirty_in_txg(zilog_t *zilog, uint64_t txg) 871 { 872 dsl_pool_t *dp = zilog->zl_dmu_pool; 873 874 if (txg_list_member(&dp->dp_dirty_zilogs, zilog, txg & TXG_MASK)) 875 return (B_TRUE); 876 return (B_FALSE); 877 } 878 879 /* 880 * Determine if the zil is dirty. The zil is considered dirty if it has 881 * any pending itx records that have not been cleaned by zil_clean(). 882 */ 883 static boolean_t 884 zilog_is_dirty(zilog_t *zilog) 885 { 886 dsl_pool_t *dp = zilog->zl_dmu_pool; 887 888 for (int t = 0; t < TXG_SIZE; t++) { 889 if (txg_list_member(&dp->dp_dirty_zilogs, zilog, t)) 890 return (B_TRUE); 891 } 892 return (B_FALSE); 893 } 894 895 /* 896 * Its called in zil_commit context (zil_process_commit_list()/zil_create()). 897 * It activates SPA_FEATURE_ZILSAXATTR feature, if its enabled. 898 * Check dsl_dataset_feature_is_active to avoid txg_wait_synced() on every 899 * zil_commit. 900 */ 901 static void 902 zil_commit_activate_saxattr_feature(zilog_t *zilog) 903 { 904 dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os); 905 uint64_t txg = 0; 906 dmu_tx_t *tx = NULL; 907 908 if (spa_feature_is_enabled(zilog->zl_spa, SPA_FEATURE_ZILSAXATTR) && 909 dmu_objset_type(zilog->zl_os) != DMU_OST_ZVOL && 910 !dsl_dataset_feature_is_active(ds, SPA_FEATURE_ZILSAXATTR)) { 911 tx = dmu_tx_create(zilog->zl_os); 912 VERIFY0(dmu_tx_assign(tx, TXG_WAIT)); 913 dsl_dataset_dirty(ds, tx); 914 txg = dmu_tx_get_txg(tx); 915 916 mutex_enter(&ds->ds_lock); 917 ds->ds_feature_activation[SPA_FEATURE_ZILSAXATTR] = 918 (void *)B_TRUE; 919 mutex_exit(&ds->ds_lock); 920 dmu_tx_commit(tx); 921 txg_wait_synced(zilog->zl_dmu_pool, txg); 922 } 923 } 924 925 /* 926 * Create an on-disk intent log. 927 */ 928 static lwb_t * 929 zil_create(zilog_t *zilog) 930 { 931 const zil_header_t *zh = zilog->zl_header; 932 lwb_t *lwb = NULL; 933 uint64_t txg = 0; 934 dmu_tx_t *tx = NULL; 935 blkptr_t blk; 936 int error = 0; 937 boolean_t slog = FALSE; 938 dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os); 939 940 941 /* 942 * Wait for any previous destroy to complete. 943 */ 944 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 945 946 ASSERT(zh->zh_claim_txg == 0); 947 ASSERT(zh->zh_replay_seq == 0); 948 949 blk = zh->zh_log; 950 951 /* 952 * Allocate an initial log block if: 953 * - there isn't one already 954 * - the existing block is the wrong endianness 955 */ 956 if (BP_IS_HOLE(&blk) || BP_SHOULD_BYTESWAP(&blk)) { 957 tx = dmu_tx_create(zilog->zl_os); 958 VERIFY0(dmu_tx_assign(tx, TXG_WAIT)); 959 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 960 txg = dmu_tx_get_txg(tx); 961 962 if (!BP_IS_HOLE(&blk)) { 963 zio_free(zilog->zl_spa, txg, &blk); 964 BP_ZERO(&blk); 965 } 966 967 error = zio_alloc_zil(zilog->zl_spa, zilog->zl_os, txg, &blk, 968 ZIL_MIN_BLKSZ, &slog); 969 if (error == 0) 970 zil_init_log_chain(zilog, &blk); 971 } 972 973 /* 974 * Allocate a log write block (lwb) for the first log block. 975 */ 976 if (error == 0) 977 lwb = zil_alloc_lwb(zilog, 0, &blk, slog, txg, LWB_STATE_NEW); 978 979 /* 980 * If we just allocated the first log block, commit our transaction 981 * and wait for zil_sync() to stuff the block pointer into zh_log. 982 * (zh is part of the MOS, so we cannot modify it in open context.) 983 */ 984 if (tx != NULL) { 985 /* 986 * If "zilsaxattr" feature is enabled on zpool, then activate 987 * it now when we're creating the ZIL chain. We can't wait with 988 * this until we write the first xattr log record because we 989 * need to wait for the feature activation to sync out. 990 */ 991 if (spa_feature_is_enabled(zilog->zl_spa, 992 SPA_FEATURE_ZILSAXATTR) && dmu_objset_type(zilog->zl_os) != 993 DMU_OST_ZVOL) { 994 mutex_enter(&ds->ds_lock); 995 ds->ds_feature_activation[SPA_FEATURE_ZILSAXATTR] = 996 (void *)B_TRUE; 997 mutex_exit(&ds->ds_lock); 998 } 999 1000 dmu_tx_commit(tx); 1001 txg_wait_synced(zilog->zl_dmu_pool, txg); 1002 } else { 1003 /* 1004 * This branch covers the case where we enable the feature on a 1005 * zpool that has existing ZIL headers. 1006 */ 1007 zil_commit_activate_saxattr_feature(zilog); 1008 } 1009 IMPLY(spa_feature_is_enabled(zilog->zl_spa, SPA_FEATURE_ZILSAXATTR) && 1010 dmu_objset_type(zilog->zl_os) != DMU_OST_ZVOL, 1011 dsl_dataset_feature_is_active(ds, SPA_FEATURE_ZILSAXATTR)); 1012 1013 ASSERT(error != 0 || memcmp(&blk, &zh->zh_log, sizeof (blk)) == 0); 1014 IMPLY(error == 0, lwb != NULL); 1015 1016 return (lwb); 1017 } 1018 1019 /* 1020 * In one tx, free all log blocks and clear the log header. If keep_first 1021 * is set, then we're replaying a log with no content. We want to keep the 1022 * first block, however, so that the first synchronous transaction doesn't 1023 * require a txg_wait_synced() in zil_create(). We don't need to 1024 * txg_wait_synced() here either when keep_first is set, because both 1025 * zil_create() and zil_destroy() will wait for any in-progress destroys 1026 * to complete. 1027 * Return B_TRUE if there were any entries to replay. 1028 */ 1029 boolean_t 1030 zil_destroy(zilog_t *zilog, boolean_t keep_first) 1031 { 1032 const zil_header_t *zh = zilog->zl_header; 1033 lwb_t *lwb; 1034 dmu_tx_t *tx; 1035 uint64_t txg; 1036 1037 /* 1038 * Wait for any previous destroy to complete. 1039 */ 1040 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 1041 1042 zilog->zl_old_header = *zh; /* debugging aid */ 1043 1044 if (BP_IS_HOLE(&zh->zh_log)) 1045 return (B_FALSE); 1046 1047 tx = dmu_tx_create(zilog->zl_os); 1048 VERIFY0(dmu_tx_assign(tx, TXG_WAIT)); 1049 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 1050 txg = dmu_tx_get_txg(tx); 1051 1052 mutex_enter(&zilog->zl_lock); 1053 1054 ASSERT3U(zilog->zl_destroy_txg, <, txg); 1055 zilog->zl_destroy_txg = txg; 1056 zilog->zl_keep_first = keep_first; 1057 1058 if (!list_is_empty(&zilog->zl_lwb_list)) { 1059 ASSERT(zh->zh_claim_txg == 0); 1060 VERIFY(!keep_first); 1061 while ((lwb = list_remove_head(&zilog->zl_lwb_list)) != NULL) { 1062 if (lwb->lwb_buf != NULL) 1063 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 1064 if (!BP_IS_HOLE(&lwb->lwb_blk)) 1065 zio_free(zilog->zl_spa, txg, &lwb->lwb_blk); 1066 zil_free_lwb(zilog, lwb); 1067 } 1068 } else if (!keep_first) { 1069 zil_destroy_sync(zilog, tx); 1070 } 1071 mutex_exit(&zilog->zl_lock); 1072 1073 dmu_tx_commit(tx); 1074 1075 return (B_TRUE); 1076 } 1077 1078 void 1079 zil_destroy_sync(zilog_t *zilog, dmu_tx_t *tx) 1080 { 1081 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 1082 (void) zil_parse(zilog, zil_free_log_block, 1083 zil_free_log_record, tx, zilog->zl_header->zh_claim_txg, B_FALSE); 1084 } 1085 1086 int 1087 zil_claim(dsl_pool_t *dp, dsl_dataset_t *ds, void *txarg) 1088 { 1089 dmu_tx_t *tx = txarg; 1090 zilog_t *zilog; 1091 uint64_t first_txg; 1092 zil_header_t *zh; 1093 objset_t *os; 1094 int error; 1095 1096 error = dmu_objset_own_obj(dp, ds->ds_object, 1097 DMU_OST_ANY, B_FALSE, B_FALSE, FTAG, &os); 1098 if (error != 0) { 1099 /* 1100 * EBUSY indicates that the objset is inconsistent, in which 1101 * case it can not have a ZIL. 1102 */ 1103 if (error != EBUSY) { 1104 cmn_err(CE_WARN, "can't open objset for %llu, error %u", 1105 (unsigned long long)ds->ds_object, error); 1106 } 1107 1108 return (0); 1109 } 1110 1111 zilog = dmu_objset_zil(os); 1112 zh = zil_header_in_syncing_context(zilog); 1113 ASSERT3U(tx->tx_txg, ==, spa_first_txg(zilog->zl_spa)); 1114 first_txg = spa_min_claim_txg(zilog->zl_spa); 1115 1116 /* 1117 * If the spa_log_state is not set to be cleared, check whether 1118 * the current uberblock is a checkpoint one and if the current 1119 * header has been claimed before moving on. 1120 * 1121 * If the current uberblock is a checkpointed uberblock then 1122 * one of the following scenarios took place: 1123 * 1124 * 1] We are currently rewinding to the checkpoint of the pool. 1125 * 2] We crashed in the middle of a checkpoint rewind but we 1126 * did manage to write the checkpointed uberblock to the 1127 * vdev labels, so when we tried to import the pool again 1128 * the checkpointed uberblock was selected from the import 1129 * procedure. 1130 * 1131 * In both cases we want to zero out all the ZIL blocks, except 1132 * the ones that have been claimed at the time of the checkpoint 1133 * (their zh_claim_txg != 0). The reason is that these blocks 1134 * may be corrupted since we may have reused their locations on 1135 * disk after we took the checkpoint. 1136 * 1137 * We could try to set spa_log_state to SPA_LOG_CLEAR earlier 1138 * when we first figure out whether the current uberblock is 1139 * checkpointed or not. Unfortunately, that would discard all 1140 * the logs, including the ones that are claimed, and we would 1141 * leak space. 1142 */ 1143 if (spa_get_log_state(zilog->zl_spa) == SPA_LOG_CLEAR || 1144 (zilog->zl_spa->spa_uberblock.ub_checkpoint_txg != 0 && 1145 zh->zh_claim_txg == 0)) { 1146 if (!BP_IS_HOLE(&zh->zh_log)) { 1147 (void) zil_parse(zilog, zil_clear_log_block, 1148 zil_noop_log_record, tx, first_txg, B_FALSE); 1149 } 1150 BP_ZERO(&zh->zh_log); 1151 if (os->os_encrypted) 1152 os->os_next_write_raw[tx->tx_txg & TXG_MASK] = B_TRUE; 1153 dsl_dataset_dirty(dmu_objset_ds(os), tx); 1154 dmu_objset_disown(os, B_FALSE, FTAG); 1155 return (0); 1156 } 1157 1158 /* 1159 * If we are not rewinding and opening the pool normally, then 1160 * the min_claim_txg should be equal to the first txg of the pool. 1161 */ 1162 ASSERT3U(first_txg, ==, spa_first_txg(zilog->zl_spa)); 1163 1164 /* 1165 * Claim all log blocks if we haven't already done so, and remember 1166 * the highest claimed sequence number. This ensures that if we can 1167 * read only part of the log now (e.g. due to a missing device), 1168 * but we can read the entire log later, we will not try to replay 1169 * or destroy beyond the last block we successfully claimed. 1170 */ 1171 ASSERT3U(zh->zh_claim_txg, <=, first_txg); 1172 if (zh->zh_claim_txg == 0 && !BP_IS_HOLE(&zh->zh_log)) { 1173 (void) zil_parse(zilog, zil_claim_log_block, 1174 zil_claim_log_record, tx, first_txg, B_FALSE); 1175 zh->zh_claim_txg = first_txg; 1176 zh->zh_claim_blk_seq = zilog->zl_parse_blk_seq; 1177 zh->zh_claim_lr_seq = zilog->zl_parse_lr_seq; 1178 if (zilog->zl_parse_lr_count || zilog->zl_parse_blk_count > 1) 1179 zh->zh_flags |= ZIL_REPLAY_NEEDED; 1180 zh->zh_flags |= ZIL_CLAIM_LR_SEQ_VALID; 1181 if (os->os_encrypted) 1182 os->os_next_write_raw[tx->tx_txg & TXG_MASK] = B_TRUE; 1183 dsl_dataset_dirty(dmu_objset_ds(os), tx); 1184 } 1185 1186 ASSERT3U(first_txg, ==, (spa_last_synced_txg(zilog->zl_spa) + 1)); 1187 dmu_objset_disown(os, B_FALSE, FTAG); 1188 return (0); 1189 } 1190 1191 /* 1192 * Check the log by walking the log chain. 1193 * Checksum errors are ok as they indicate the end of the chain. 1194 * Any other error (no device or read failure) returns an error. 1195 */ 1196 int 1197 zil_check_log_chain(dsl_pool_t *dp, dsl_dataset_t *ds, void *tx) 1198 { 1199 (void) dp; 1200 zilog_t *zilog; 1201 objset_t *os; 1202 blkptr_t *bp; 1203 int error; 1204 1205 ASSERT(tx == NULL); 1206 1207 error = dmu_objset_from_ds(ds, &os); 1208 if (error != 0) { 1209 cmn_err(CE_WARN, "can't open objset %llu, error %d", 1210 (unsigned long long)ds->ds_object, error); 1211 return (0); 1212 } 1213 1214 zilog = dmu_objset_zil(os); 1215 bp = (blkptr_t *)&zilog->zl_header->zh_log; 1216 1217 if (!BP_IS_HOLE(bp)) { 1218 vdev_t *vd; 1219 boolean_t valid = B_TRUE; 1220 1221 /* 1222 * Check the first block and determine if it's on a log device 1223 * which may have been removed or faulted prior to loading this 1224 * pool. If so, there's no point in checking the rest of the 1225 * log as its content should have already been synced to the 1226 * pool. 1227 */ 1228 spa_config_enter(os->os_spa, SCL_STATE, FTAG, RW_READER); 1229 vd = vdev_lookup_top(os->os_spa, DVA_GET_VDEV(&bp->blk_dva[0])); 1230 if (vd->vdev_islog && vdev_is_dead(vd)) 1231 valid = vdev_log_state_valid(vd); 1232 spa_config_exit(os->os_spa, SCL_STATE, FTAG); 1233 1234 if (!valid) 1235 return (0); 1236 1237 /* 1238 * Check whether the current uberblock is checkpointed (e.g. 1239 * we are rewinding) and whether the current header has been 1240 * claimed or not. If it hasn't then skip verifying it. We 1241 * do this because its ZIL blocks may be part of the pool's 1242 * state before the rewind, which is no longer valid. 1243 */ 1244 zil_header_t *zh = zil_header_in_syncing_context(zilog); 1245 if (zilog->zl_spa->spa_uberblock.ub_checkpoint_txg != 0 && 1246 zh->zh_claim_txg == 0) 1247 return (0); 1248 } 1249 1250 /* 1251 * Because tx == NULL, zil_claim_log_block() will not actually claim 1252 * any blocks, but just determine whether it is possible to do so. 1253 * In addition to checking the log chain, zil_claim_log_block() 1254 * will invoke zio_claim() with a done func of spa_claim_notify(), 1255 * which will update spa_max_claim_txg. See spa_load() for details. 1256 */ 1257 error = zil_parse(zilog, zil_claim_log_block, zil_claim_log_record, tx, 1258 zilog->zl_header->zh_claim_txg ? -1ULL : 1259 spa_min_claim_txg(os->os_spa), B_FALSE); 1260 1261 return ((error == ECKSUM || error == ENOENT) ? 0 : error); 1262 } 1263 1264 /* 1265 * When an itx is "skipped", this function is used to properly mark the 1266 * waiter as "done, and signal any thread(s) waiting on it. An itx can 1267 * be skipped (and not committed to an lwb) for a variety of reasons, 1268 * one of them being that the itx was committed via spa_sync(), prior to 1269 * it being committed to an lwb; this can happen if a thread calling 1270 * zil_commit() is racing with spa_sync(). 1271 */ 1272 static void 1273 zil_commit_waiter_skip(zil_commit_waiter_t *zcw) 1274 { 1275 mutex_enter(&zcw->zcw_lock); 1276 ASSERT3B(zcw->zcw_done, ==, B_FALSE); 1277 zcw->zcw_done = B_TRUE; 1278 cv_broadcast(&zcw->zcw_cv); 1279 mutex_exit(&zcw->zcw_lock); 1280 } 1281 1282 /* 1283 * This function is used when the given waiter is to be linked into an 1284 * lwb's "lwb_waiter" list; i.e. when the itx is committed to the lwb. 1285 * At this point, the waiter will no longer be referenced by the itx, 1286 * and instead, will be referenced by the lwb. 1287 */ 1288 static void 1289 zil_commit_waiter_link_lwb(zil_commit_waiter_t *zcw, lwb_t *lwb) 1290 { 1291 /* 1292 * The lwb_waiters field of the lwb is protected by the zilog's 1293 * zl_issuer_lock while the lwb is open and zl_lock otherwise. 1294 * zl_issuer_lock also protects leaving the open state. 1295 * zcw_lwb setting is protected by zl_issuer_lock and state != 1296 * flush_done, which transition is protected by zl_lock. 1297 */ 1298 ASSERT(MUTEX_HELD(&lwb->lwb_zilog->zl_issuer_lock)); 1299 IMPLY(lwb->lwb_state != LWB_STATE_OPENED, 1300 MUTEX_HELD(&lwb->lwb_zilog->zl_lock)); 1301 ASSERT3S(lwb->lwb_state, !=, LWB_STATE_NEW); 1302 ASSERT3S(lwb->lwb_state, !=, LWB_STATE_FLUSH_DONE); 1303 1304 ASSERT(!list_link_active(&zcw->zcw_node)); 1305 list_insert_tail(&lwb->lwb_waiters, zcw); 1306 ASSERT3P(zcw->zcw_lwb, ==, NULL); 1307 zcw->zcw_lwb = lwb; 1308 } 1309 1310 /* 1311 * This function is used when zio_alloc_zil() fails to allocate a ZIL 1312 * block, and the given waiter must be linked to the "nolwb waiters" 1313 * list inside of zil_process_commit_list(). 1314 */ 1315 static void 1316 zil_commit_waiter_link_nolwb(zil_commit_waiter_t *zcw, list_t *nolwb) 1317 { 1318 ASSERT(!list_link_active(&zcw->zcw_node)); 1319 list_insert_tail(nolwb, zcw); 1320 ASSERT3P(zcw->zcw_lwb, ==, NULL); 1321 } 1322 1323 void 1324 zil_lwb_add_block(lwb_t *lwb, const blkptr_t *bp) 1325 { 1326 avl_tree_t *t = &lwb->lwb_vdev_tree; 1327 avl_index_t where; 1328 zil_vdev_node_t *zv, zvsearch; 1329 int ndvas = BP_GET_NDVAS(bp); 1330 int i; 1331 1332 ASSERT3S(lwb->lwb_state, !=, LWB_STATE_WRITE_DONE); 1333 ASSERT3S(lwb->lwb_state, !=, LWB_STATE_FLUSH_DONE); 1334 1335 if (zil_nocacheflush) 1336 return; 1337 1338 mutex_enter(&lwb->lwb_vdev_lock); 1339 for (i = 0; i < ndvas; i++) { 1340 zvsearch.zv_vdev = DVA_GET_VDEV(&bp->blk_dva[i]); 1341 if (avl_find(t, &zvsearch, &where) == NULL) { 1342 zv = kmem_alloc(sizeof (*zv), KM_SLEEP); 1343 zv->zv_vdev = zvsearch.zv_vdev; 1344 avl_insert(t, zv, where); 1345 } 1346 } 1347 mutex_exit(&lwb->lwb_vdev_lock); 1348 } 1349 1350 static void 1351 zil_lwb_flush_defer(lwb_t *lwb, lwb_t *nlwb) 1352 { 1353 avl_tree_t *src = &lwb->lwb_vdev_tree; 1354 avl_tree_t *dst = &nlwb->lwb_vdev_tree; 1355 void *cookie = NULL; 1356 zil_vdev_node_t *zv; 1357 1358 ASSERT3S(lwb->lwb_state, ==, LWB_STATE_WRITE_DONE); 1359 ASSERT3S(nlwb->lwb_state, !=, LWB_STATE_WRITE_DONE); 1360 ASSERT3S(nlwb->lwb_state, !=, LWB_STATE_FLUSH_DONE); 1361 1362 /* 1363 * While 'lwb' is at a point in its lifetime where lwb_vdev_tree does 1364 * not need the protection of lwb_vdev_lock (it will only be modified 1365 * while holding zilog->zl_lock) as its writes and those of its 1366 * children have all completed. The younger 'nlwb' may be waiting on 1367 * future writes to additional vdevs. 1368 */ 1369 mutex_enter(&nlwb->lwb_vdev_lock); 1370 /* 1371 * Tear down the 'lwb' vdev tree, ensuring that entries which do not 1372 * exist in 'nlwb' are moved to it, freeing any would-be duplicates. 1373 */ 1374 while ((zv = avl_destroy_nodes(src, &cookie)) != NULL) { 1375 avl_index_t where; 1376 1377 if (avl_find(dst, zv, &where) == NULL) { 1378 avl_insert(dst, zv, where); 1379 } else { 1380 kmem_free(zv, sizeof (*zv)); 1381 } 1382 } 1383 mutex_exit(&nlwb->lwb_vdev_lock); 1384 } 1385 1386 void 1387 zil_lwb_add_txg(lwb_t *lwb, uint64_t txg) 1388 { 1389 lwb->lwb_max_txg = MAX(lwb->lwb_max_txg, txg); 1390 } 1391 1392 /* 1393 * This function is a called after all vdevs associated with a given lwb 1394 * write have completed their DKIOCFLUSHWRITECACHE command; or as soon 1395 * as the lwb write completes, if "zil_nocacheflush" is set. Further, 1396 * all "previous" lwb's will have completed before this function is 1397 * called; i.e. this function is called for all previous lwbs before 1398 * it's called for "this" lwb (enforced via zio the dependencies 1399 * configured in zil_lwb_set_zio_dependency()). 1400 * 1401 * The intention is for this function to be called as soon as the 1402 * contents of an lwb are considered "stable" on disk, and will survive 1403 * any sudden loss of power. At this point, any threads waiting for the 1404 * lwb to reach this state are signalled, and the "waiter" structures 1405 * are marked "done". 1406 */ 1407 static void 1408 zil_lwb_flush_vdevs_done(zio_t *zio) 1409 { 1410 lwb_t *lwb = zio->io_private; 1411 zilog_t *zilog = lwb->lwb_zilog; 1412 zil_commit_waiter_t *zcw; 1413 itx_t *itx; 1414 1415 spa_config_exit(zilog->zl_spa, SCL_STATE, lwb); 1416 1417 hrtime_t t = gethrtime() - lwb->lwb_issued_timestamp; 1418 1419 mutex_enter(&zilog->zl_lock); 1420 1421 zilog->zl_last_lwb_latency = (zilog->zl_last_lwb_latency * 7 + t) / 8; 1422 1423 lwb->lwb_root_zio = NULL; 1424 1425 ASSERT3S(lwb->lwb_state, ==, LWB_STATE_WRITE_DONE); 1426 lwb->lwb_state = LWB_STATE_FLUSH_DONE; 1427 1428 if (zilog->zl_last_lwb_opened == lwb) { 1429 /* 1430 * Remember the highest committed log sequence number 1431 * for ztest. We only update this value when all the log 1432 * writes succeeded, because ztest wants to ASSERT that 1433 * it got the whole log chain. 1434 */ 1435 zilog->zl_commit_lr_seq = zilog->zl_lr_seq; 1436 } 1437 1438 while ((itx = list_remove_head(&lwb->lwb_itxs)) != NULL) 1439 zil_itx_destroy(itx); 1440 1441 while ((zcw = list_remove_head(&lwb->lwb_waiters)) != NULL) { 1442 mutex_enter(&zcw->zcw_lock); 1443 1444 ASSERT3P(zcw->zcw_lwb, ==, lwb); 1445 zcw->zcw_lwb = NULL; 1446 /* 1447 * We expect any ZIO errors from child ZIOs to have been 1448 * propagated "up" to this specific LWB's root ZIO, in 1449 * order for this error handling to work correctly. This 1450 * includes ZIO errors from either this LWB's write or 1451 * flush, as well as any errors from other dependent LWBs 1452 * (e.g. a root LWB ZIO that might be a child of this LWB). 1453 * 1454 * With that said, it's important to note that LWB flush 1455 * errors are not propagated up to the LWB root ZIO. 1456 * This is incorrect behavior, and results in VDEV flush 1457 * errors not being handled correctly here. See the 1458 * comment above the call to "zio_flush" for details. 1459 */ 1460 1461 zcw->zcw_zio_error = zio->io_error; 1462 1463 ASSERT3B(zcw->zcw_done, ==, B_FALSE); 1464 zcw->zcw_done = B_TRUE; 1465 cv_broadcast(&zcw->zcw_cv); 1466 1467 mutex_exit(&zcw->zcw_lock); 1468 } 1469 1470 uint64_t txg = lwb->lwb_issued_txg; 1471 1472 /* Once we drop the lock, lwb may be freed by zil_sync(). */ 1473 mutex_exit(&zilog->zl_lock); 1474 1475 mutex_enter(&zilog->zl_lwb_io_lock); 1476 ASSERT3U(zilog->zl_lwb_inflight[txg & TXG_MASK], >, 0); 1477 zilog->zl_lwb_inflight[txg & TXG_MASK]--; 1478 if (zilog->zl_lwb_inflight[txg & TXG_MASK] == 0) 1479 cv_broadcast(&zilog->zl_lwb_io_cv); 1480 mutex_exit(&zilog->zl_lwb_io_lock); 1481 } 1482 1483 /* 1484 * Wait for the completion of all issued write/flush of that txg provided. 1485 * It guarantees zil_lwb_flush_vdevs_done() is called and returned. 1486 */ 1487 static void 1488 zil_lwb_flush_wait_all(zilog_t *zilog, uint64_t txg) 1489 { 1490 ASSERT3U(txg, ==, spa_syncing_txg(zilog->zl_spa)); 1491 1492 mutex_enter(&zilog->zl_lwb_io_lock); 1493 while (zilog->zl_lwb_inflight[txg & TXG_MASK] > 0) 1494 cv_wait(&zilog->zl_lwb_io_cv, &zilog->zl_lwb_io_lock); 1495 mutex_exit(&zilog->zl_lwb_io_lock); 1496 1497 #ifdef ZFS_DEBUG 1498 mutex_enter(&zilog->zl_lock); 1499 mutex_enter(&zilog->zl_lwb_io_lock); 1500 lwb_t *lwb = list_head(&zilog->zl_lwb_list); 1501 while (lwb != NULL) { 1502 if (lwb->lwb_issued_txg <= txg) { 1503 ASSERT(lwb->lwb_state != LWB_STATE_ISSUED); 1504 ASSERT(lwb->lwb_state != LWB_STATE_WRITE_DONE); 1505 IMPLY(lwb->lwb_issued_txg > 0, 1506 lwb->lwb_state == LWB_STATE_FLUSH_DONE); 1507 } 1508 IMPLY(lwb->lwb_state == LWB_STATE_WRITE_DONE || 1509 lwb->lwb_state == LWB_STATE_FLUSH_DONE, 1510 lwb->lwb_buf == NULL); 1511 lwb = list_next(&zilog->zl_lwb_list, lwb); 1512 } 1513 mutex_exit(&zilog->zl_lwb_io_lock); 1514 mutex_exit(&zilog->zl_lock); 1515 #endif 1516 } 1517 1518 /* 1519 * This is called when an lwb's write zio completes. The callback's 1520 * purpose is to issue the DKIOCFLUSHWRITECACHE commands for the vdevs 1521 * in the lwb's lwb_vdev_tree. The tree will contain the vdevs involved 1522 * in writing out this specific lwb's data, and in the case that cache 1523 * flushes have been deferred, vdevs involved in writing the data for 1524 * previous lwbs. The writes corresponding to all the vdevs in the 1525 * lwb_vdev_tree will have completed by the time this is called, due to 1526 * the zio dependencies configured in zil_lwb_set_zio_dependency(), 1527 * which takes deferred flushes into account. The lwb will be "done" 1528 * once zil_lwb_flush_vdevs_done() is called, which occurs in the zio 1529 * completion callback for the lwb's root zio. 1530 */ 1531 static void 1532 zil_lwb_write_done(zio_t *zio) 1533 { 1534 lwb_t *lwb = zio->io_private; 1535 spa_t *spa = zio->io_spa; 1536 zilog_t *zilog = lwb->lwb_zilog; 1537 avl_tree_t *t = &lwb->lwb_vdev_tree; 1538 void *cookie = NULL; 1539 zil_vdev_node_t *zv; 1540 lwb_t *nlwb; 1541 1542 ASSERT3S(spa_config_held(spa, SCL_STATE, RW_READER), !=, 0); 1543 1544 abd_free(zio->io_abd); 1545 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 1546 lwb->lwb_buf = NULL; 1547 1548 mutex_enter(&zilog->zl_lock); 1549 ASSERT3S(lwb->lwb_state, ==, LWB_STATE_ISSUED); 1550 lwb->lwb_state = LWB_STATE_WRITE_DONE; 1551 lwb->lwb_child_zio = NULL; 1552 lwb->lwb_write_zio = NULL; 1553 1554 /* 1555 * If nlwb is not yet issued, zil_lwb_set_zio_dependency() is not 1556 * called for it yet, and when it will be, it won't be able to make 1557 * its write ZIO a parent this ZIO. In such case we can not defer 1558 * our flushes or below may be a race between the done callbacks. 1559 */ 1560 nlwb = list_next(&zilog->zl_lwb_list, lwb); 1561 if (nlwb && nlwb->lwb_state != LWB_STATE_ISSUED) 1562 nlwb = NULL; 1563 mutex_exit(&zilog->zl_lock); 1564 1565 if (avl_numnodes(t) == 0) 1566 return; 1567 1568 /* 1569 * If there was an IO error, we're not going to call zio_flush() 1570 * on these vdevs, so we simply empty the tree and free the 1571 * nodes. We avoid calling zio_flush() since there isn't any 1572 * good reason for doing so, after the lwb block failed to be 1573 * written out. 1574 * 1575 * Additionally, we don't perform any further error handling at 1576 * this point (e.g. setting "zcw_zio_error" appropriately), as 1577 * we expect that to occur in "zil_lwb_flush_vdevs_done" (thus, 1578 * we expect any error seen here, to have been propagated to 1579 * that function). 1580 */ 1581 if (zio->io_error != 0) { 1582 while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) 1583 kmem_free(zv, sizeof (*zv)); 1584 return; 1585 } 1586 1587 /* 1588 * If this lwb does not have any threads waiting for it to 1589 * complete, we want to defer issuing the DKIOCFLUSHWRITECACHE 1590 * command to the vdevs written to by "this" lwb, and instead 1591 * rely on the "next" lwb to handle the DKIOCFLUSHWRITECACHE 1592 * command for those vdevs. Thus, we merge the vdev tree of 1593 * "this" lwb with the vdev tree of the "next" lwb in the list, 1594 * and assume the "next" lwb will handle flushing the vdevs (or 1595 * deferring the flush(s) again). 1596 * 1597 * This is a useful performance optimization, especially for 1598 * workloads with lots of async write activity and few sync 1599 * write and/or fsync activity, as it has the potential to 1600 * coalesce multiple flush commands to a vdev into one. 1601 */ 1602 if (list_is_empty(&lwb->lwb_waiters) && nlwb != NULL) { 1603 zil_lwb_flush_defer(lwb, nlwb); 1604 ASSERT(avl_is_empty(&lwb->lwb_vdev_tree)); 1605 return; 1606 } 1607 1608 while ((zv = avl_destroy_nodes(t, &cookie)) != NULL) { 1609 vdev_t *vd = vdev_lookup_top(spa, zv->zv_vdev); 1610 if (vd != NULL && !vd->vdev_nowritecache) { 1611 /* 1612 * The "ZIO_FLAG_DONT_PROPAGATE" is currently 1613 * always used within "zio_flush". This means, 1614 * any errors when flushing the vdev(s), will 1615 * (unfortunately) not be handled correctly, 1616 * since these "zio_flush" errors will not be 1617 * propagated up to "zil_lwb_flush_vdevs_done". 1618 */ 1619 zio_flush(lwb->lwb_root_zio, vd); 1620 } 1621 kmem_free(zv, sizeof (*zv)); 1622 } 1623 } 1624 1625 /* 1626 * Build the zio dependency chain, which is used to preserve the ordering of 1627 * lwb completions that is required by the semantics of the ZIL. Each new lwb 1628 * zio becomes a parent of the previous lwb zio, such that the new lwb's zio 1629 * cannot complete until the previous lwb's zio completes. 1630 * 1631 * This is required by the semantics of zil_commit(): the commit waiters 1632 * attached to the lwbs will be woken in the lwb zio's completion callback, 1633 * so this zio dependency graph ensures the waiters are woken in the correct 1634 * order (the same order the lwbs were created). 1635 */ 1636 static void 1637 zil_lwb_set_zio_dependency(zilog_t *zilog, lwb_t *lwb) 1638 { 1639 ASSERT(MUTEX_HELD(&zilog->zl_lock)); 1640 1641 lwb_t *prev_lwb = list_prev(&zilog->zl_lwb_list, lwb); 1642 if (prev_lwb == NULL || 1643 prev_lwb->lwb_state == LWB_STATE_FLUSH_DONE) 1644 return; 1645 1646 /* 1647 * If the previous lwb's write hasn't already completed, we also want 1648 * to order the completion of the lwb write zios (above, we only order 1649 * the completion of the lwb root zios). This is required because of 1650 * how we can defer the DKIOCFLUSHWRITECACHE commands for each lwb. 1651 * 1652 * When the DKIOCFLUSHWRITECACHE commands are deferred, the previous 1653 * lwb will rely on this lwb to flush the vdevs written to by that 1654 * previous lwb. Thus, we need to ensure this lwb doesn't issue the 1655 * flush until after the previous lwb's write completes. We ensure 1656 * this ordering by setting the zio parent/child relationship here. 1657 * 1658 * Without this relationship on the lwb's write zio, it's possible 1659 * for this lwb's write to complete prior to the previous lwb's write 1660 * completing; and thus, the vdevs for the previous lwb would be 1661 * flushed prior to that lwb's data being written to those vdevs (the 1662 * vdevs are flushed in the lwb write zio's completion handler, 1663 * zil_lwb_write_done()). 1664 */ 1665 if (prev_lwb->lwb_state == LWB_STATE_ISSUED) { 1666 ASSERT3P(prev_lwb->lwb_write_zio, !=, NULL); 1667 zio_add_child(lwb->lwb_write_zio, prev_lwb->lwb_write_zio); 1668 } else { 1669 ASSERT3S(prev_lwb->lwb_state, ==, LWB_STATE_WRITE_DONE); 1670 } 1671 1672 ASSERT3P(prev_lwb->lwb_root_zio, !=, NULL); 1673 zio_add_child(lwb->lwb_root_zio, prev_lwb->lwb_root_zio); 1674 } 1675 1676 1677 /* 1678 * This function's purpose is to "open" an lwb such that it is ready to 1679 * accept new itxs being committed to it. This function is idempotent; if 1680 * the passed in lwb has already been opened, it is essentially a no-op. 1681 */ 1682 static void 1683 zil_lwb_write_open(zilog_t *zilog, lwb_t *lwb) 1684 { 1685 ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); 1686 1687 if (lwb->lwb_state != LWB_STATE_NEW) { 1688 ASSERT3S(lwb->lwb_state, ==, LWB_STATE_OPENED); 1689 return; 1690 } 1691 1692 mutex_enter(&zilog->zl_lock); 1693 lwb->lwb_state = LWB_STATE_OPENED; 1694 zilog->zl_last_lwb_opened = lwb; 1695 mutex_exit(&zilog->zl_lock); 1696 } 1697 1698 /* 1699 * Define a limited set of intent log block sizes. 1700 * 1701 * These must be a multiple of 4KB. Note only the amount used (again 1702 * aligned to 4KB) actually gets written. However, we can't always just 1703 * allocate SPA_OLD_MAXBLOCKSIZE as the slog space could be exhausted. 1704 */ 1705 static const struct { 1706 uint64_t limit; 1707 uint64_t blksz; 1708 } zil_block_buckets[] = { 1709 { 4096, 4096 }, /* non TX_WRITE */ 1710 { 8192 + 4096, 8192 + 4096 }, /* database */ 1711 { 32768 + 4096, 32768 + 4096 }, /* NFS writes */ 1712 { 65536 + 4096, 65536 + 4096 }, /* 64KB writes */ 1713 { 131072, 131072 }, /* < 128KB writes */ 1714 { 131072 +4096, 65536 + 4096 }, /* 128KB writes */ 1715 { UINT64_MAX, SPA_OLD_MAXBLOCKSIZE}, /* > 128KB writes */ 1716 }; 1717 1718 /* 1719 * Maximum block size used by the ZIL. This is picked up when the ZIL is 1720 * initialized. Otherwise this should not be used directly; see 1721 * zl_max_block_size instead. 1722 */ 1723 static uint_t zil_maxblocksize = SPA_OLD_MAXBLOCKSIZE; 1724 1725 /* 1726 * Close the log block for being issued and allocate the next one. 1727 * Has to be called under zl_issuer_lock to chain more lwbs. 1728 */ 1729 static lwb_t * 1730 zil_lwb_write_close(zilog_t *zilog, lwb_t *lwb, lwb_state_t state) 1731 { 1732 int i; 1733 1734 ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); 1735 ASSERT3S(lwb->lwb_state, ==, LWB_STATE_OPENED); 1736 lwb->lwb_state = LWB_STATE_CLOSED; 1737 1738 /* 1739 * If there was an allocation failure then returned NULL will trigger 1740 * zil_commit_writer_stall() at the caller. This is inherently racy, 1741 * since allocation may not have happened yet. 1742 */ 1743 if (lwb->lwb_error != 0) 1744 return (NULL); 1745 1746 /* 1747 * Log blocks are pre-allocated. Here we select the size of the next 1748 * block, based on size used in the last block. 1749 * - first find the smallest bucket that will fit the block from a 1750 * limited set of block sizes. This is because it's faster to write 1751 * blocks allocated from the same metaslab as they are adjacent or 1752 * close. 1753 * - next find the maximum from the new suggested size and an array of 1754 * previous sizes. This lessens a picket fence effect of wrongly 1755 * guessing the size if we have a stream of say 2k, 64k, 2k, 64k 1756 * requests. 1757 * 1758 * Note we only write what is used, but we can't just allocate 1759 * the maximum block size because we can exhaust the available 1760 * pool log space. 1761 */ 1762 uint64_t zil_blksz = zilog->zl_cur_used + sizeof (zil_chain_t); 1763 for (i = 0; zil_blksz > zil_block_buckets[i].limit; i++) 1764 continue; 1765 zil_blksz = MIN(zil_block_buckets[i].blksz, zilog->zl_max_block_size); 1766 zilog->zl_prev_blks[zilog->zl_prev_rotor] = zil_blksz; 1767 for (i = 0; i < ZIL_PREV_BLKS; i++) 1768 zil_blksz = MAX(zil_blksz, zilog->zl_prev_blks[i]); 1769 DTRACE_PROBE3(zil__block__size, zilog_t *, zilog, 1770 uint64_t, zil_blksz, 1771 uint64_t, zilog->zl_prev_blks[zilog->zl_prev_rotor]); 1772 zilog->zl_prev_rotor = (zilog->zl_prev_rotor + 1) & (ZIL_PREV_BLKS - 1); 1773 1774 return (zil_alloc_lwb(zilog, zil_blksz, NULL, 0, 0, state)); 1775 } 1776 1777 /* 1778 * Finalize previously closed block and issue the write zio. 1779 */ 1780 static void 1781 zil_lwb_write_issue(zilog_t *zilog, lwb_t *lwb) 1782 { 1783 spa_t *spa = zilog->zl_spa; 1784 zil_chain_t *zilc; 1785 boolean_t slog; 1786 zbookmark_phys_t zb; 1787 zio_priority_t prio; 1788 int error; 1789 1790 ASSERT3S(lwb->lwb_state, ==, LWB_STATE_CLOSED); 1791 1792 /* Actually fill the lwb with the data. */ 1793 for (itx_t *itx = list_head(&lwb->lwb_itxs); itx; 1794 itx = list_next(&lwb->lwb_itxs, itx)) 1795 zil_lwb_commit(zilog, lwb, itx); 1796 lwb->lwb_nused = lwb->lwb_nfilled; 1797 1798 lwb->lwb_root_zio = zio_root(spa, zil_lwb_flush_vdevs_done, lwb, 1799 ZIO_FLAG_CANFAIL); 1800 1801 /* 1802 * The lwb is now ready to be issued, but it can be only if it already 1803 * got its block pointer allocated or the allocation has failed. 1804 * Otherwise leave it as-is, relying on some other thread to issue it 1805 * after allocating its block pointer via calling zil_lwb_write_issue() 1806 * for the previous lwb(s) in the chain. 1807 */ 1808 mutex_enter(&zilog->zl_lock); 1809 lwb->lwb_state = LWB_STATE_READY; 1810 if (BP_IS_HOLE(&lwb->lwb_blk) && lwb->lwb_error == 0) { 1811 mutex_exit(&zilog->zl_lock); 1812 return; 1813 } 1814 mutex_exit(&zilog->zl_lock); 1815 1816 next_lwb: 1817 if (lwb->lwb_slim) 1818 zilc = (zil_chain_t *)lwb->lwb_buf; 1819 else 1820 zilc = (zil_chain_t *)(lwb->lwb_buf + lwb->lwb_nmax); 1821 int wsz = lwb->lwb_sz; 1822 if (lwb->lwb_error == 0) { 1823 abd_t *lwb_abd = abd_get_from_buf(lwb->lwb_buf, lwb->lwb_sz); 1824 if (!lwb->lwb_slog || zilog->zl_cur_used <= zil_slog_bulk) 1825 prio = ZIO_PRIORITY_SYNC_WRITE; 1826 else 1827 prio = ZIO_PRIORITY_ASYNC_WRITE; 1828 SET_BOOKMARK(&zb, lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_OBJSET], 1829 ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, 1830 lwb->lwb_blk.blk_cksum.zc_word[ZIL_ZC_SEQ]); 1831 lwb->lwb_write_zio = zio_rewrite(lwb->lwb_root_zio, spa, 0, 1832 &lwb->lwb_blk, lwb_abd, lwb->lwb_sz, zil_lwb_write_done, 1833 lwb, prio, ZIO_FLAG_CANFAIL, &zb); 1834 zil_lwb_add_block(lwb, &lwb->lwb_blk); 1835 1836 if (lwb->lwb_slim) { 1837 /* For Slim ZIL only write what is used. */ 1838 wsz = P2ROUNDUP_TYPED(lwb->lwb_nused, ZIL_MIN_BLKSZ, 1839 int); 1840 ASSERT3S(wsz, <=, lwb->lwb_sz); 1841 zio_shrink(lwb->lwb_write_zio, wsz); 1842 wsz = lwb->lwb_write_zio->io_size; 1843 } 1844 memset(lwb->lwb_buf + lwb->lwb_nused, 0, wsz - lwb->lwb_nused); 1845 zilc->zc_pad = 0; 1846 zilc->zc_nused = lwb->lwb_nused; 1847 zilc->zc_eck.zec_cksum = lwb->lwb_blk.blk_cksum; 1848 } else { 1849 /* 1850 * We can't write the lwb if there was an allocation failure, 1851 * so create a null zio instead just to maintain dependencies. 1852 */ 1853 lwb->lwb_write_zio = zio_null(lwb->lwb_root_zio, spa, NULL, 1854 zil_lwb_write_done, lwb, ZIO_FLAG_CANFAIL); 1855 lwb->lwb_write_zio->io_error = lwb->lwb_error; 1856 } 1857 if (lwb->lwb_child_zio) 1858 zio_add_child(lwb->lwb_write_zio, lwb->lwb_child_zio); 1859 1860 /* 1861 * Open transaction to allocate the next block pointer. 1862 */ 1863 dmu_tx_t *tx = dmu_tx_create(zilog->zl_os); 1864 VERIFY0(dmu_tx_assign(tx, TXG_WAIT | TXG_NOTHROTTLE)); 1865 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 1866 uint64_t txg = dmu_tx_get_txg(tx); 1867 1868 /* 1869 * Allocate next the block pointer unless we are already in error. 1870 */ 1871 lwb_t *nlwb = list_next(&zilog->zl_lwb_list, lwb); 1872 blkptr_t *bp = &zilc->zc_next_blk; 1873 BP_ZERO(bp); 1874 error = lwb->lwb_error; 1875 if (error == 0) { 1876 error = zio_alloc_zil(spa, zilog->zl_os, txg, bp, nlwb->lwb_sz, 1877 &slog); 1878 } 1879 if (error == 0) { 1880 ASSERT3U(bp->blk_birth, ==, txg); 1881 BP_SET_CHECKSUM(bp, nlwb->lwb_slim ? ZIO_CHECKSUM_ZILOG2 : 1882 ZIO_CHECKSUM_ZILOG); 1883 bp->blk_cksum = lwb->lwb_blk.blk_cksum; 1884 bp->blk_cksum.zc_word[ZIL_ZC_SEQ]++; 1885 } 1886 1887 /* 1888 * Reduce TXG open time by incrementing inflight counter and committing 1889 * the transaciton. zil_sync() will wait for it to return to zero. 1890 */ 1891 mutex_enter(&zilog->zl_lwb_io_lock); 1892 lwb->lwb_issued_txg = txg; 1893 zilog->zl_lwb_inflight[txg & TXG_MASK]++; 1894 zilog->zl_lwb_max_issued_txg = MAX(txg, zilog->zl_lwb_max_issued_txg); 1895 mutex_exit(&zilog->zl_lwb_io_lock); 1896 dmu_tx_commit(tx); 1897 1898 spa_config_enter(spa, SCL_STATE, lwb, RW_READER); 1899 1900 /* 1901 * We've completed all potentially blocking operations. Update the 1902 * nlwb and allow it proceed without possible lock order reversals. 1903 */ 1904 mutex_enter(&zilog->zl_lock); 1905 zil_lwb_set_zio_dependency(zilog, lwb); 1906 lwb->lwb_state = LWB_STATE_ISSUED; 1907 1908 if (nlwb) { 1909 nlwb->lwb_blk = *bp; 1910 nlwb->lwb_error = error; 1911 nlwb->lwb_slog = slog; 1912 nlwb->lwb_alloc_txg = txg; 1913 if (nlwb->lwb_state != LWB_STATE_READY) 1914 nlwb = NULL; 1915 } 1916 mutex_exit(&zilog->zl_lock); 1917 1918 if (lwb->lwb_slog) { 1919 ZIL_STAT_BUMP(zilog, zil_itx_metaslab_slog_count); 1920 ZIL_STAT_INCR(zilog, zil_itx_metaslab_slog_bytes, 1921 lwb->lwb_nused); 1922 ZIL_STAT_INCR(zilog, zil_itx_metaslab_slog_write, 1923 wsz); 1924 ZIL_STAT_INCR(zilog, zil_itx_metaslab_slog_alloc, 1925 BP_GET_LSIZE(&lwb->lwb_blk)); 1926 } else { 1927 ZIL_STAT_BUMP(zilog, zil_itx_metaslab_normal_count); 1928 ZIL_STAT_INCR(zilog, zil_itx_metaslab_normal_bytes, 1929 lwb->lwb_nused); 1930 ZIL_STAT_INCR(zilog, zil_itx_metaslab_normal_write, 1931 wsz); 1932 ZIL_STAT_INCR(zilog, zil_itx_metaslab_normal_alloc, 1933 BP_GET_LSIZE(&lwb->lwb_blk)); 1934 } 1935 lwb->lwb_issued_timestamp = gethrtime(); 1936 if (lwb->lwb_child_zio) 1937 zio_nowait(lwb->lwb_child_zio); 1938 zio_nowait(lwb->lwb_write_zio); 1939 zio_nowait(lwb->lwb_root_zio); 1940 1941 /* 1942 * If nlwb was ready when we gave it the block pointer, 1943 * it is on us to issue it and possibly following ones. 1944 */ 1945 lwb = nlwb; 1946 if (lwb) 1947 goto next_lwb; 1948 } 1949 1950 /* 1951 * Maximum amount of data that can be put into single log block. 1952 */ 1953 uint64_t 1954 zil_max_log_data(zilog_t *zilog, size_t hdrsize) 1955 { 1956 return (zilog->zl_max_block_size - sizeof (zil_chain_t) - hdrsize); 1957 } 1958 1959 /* 1960 * Maximum amount of log space we agree to waste to reduce number of 1961 * WR_NEED_COPY chunks to reduce zl_get_data() overhead (~12%). 1962 */ 1963 static inline uint64_t 1964 zil_max_waste_space(zilog_t *zilog) 1965 { 1966 return (zil_max_log_data(zilog, sizeof (lr_write_t)) / 8); 1967 } 1968 1969 /* 1970 * Maximum amount of write data for WR_COPIED. For correctness, consumers 1971 * must fall back to WR_NEED_COPY if we can't fit the entire record into one 1972 * maximum sized log block, because each WR_COPIED record must fit in a 1973 * single log block. For space efficiency, we want to fit two records into a 1974 * max-sized log block. 1975 */ 1976 uint64_t 1977 zil_max_copied_data(zilog_t *zilog) 1978 { 1979 return ((zilog->zl_max_block_size - sizeof (zil_chain_t)) / 2 - 1980 sizeof (lr_write_t)); 1981 } 1982 1983 /* 1984 * Estimate space needed in the lwb for the itx. Allocate more lwbs or 1985 * split the itx as needed, but don't touch the actual transaction data. 1986 * Has to be called under zl_issuer_lock to call zil_lwb_write_close() 1987 * to chain more lwbs. 1988 */ 1989 static lwb_t * 1990 zil_lwb_assign(zilog_t *zilog, lwb_t *lwb, itx_t *itx, list_t *ilwbs) 1991 { 1992 itx_t *citx; 1993 lr_t *lr, *clr; 1994 lr_write_t *lrw; 1995 uint64_t dlen, dnow, lwb_sp, reclen, max_log_data; 1996 1997 ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); 1998 ASSERT3P(lwb, !=, NULL); 1999 ASSERT3P(lwb->lwb_buf, !=, NULL); 2000 2001 zil_lwb_write_open(zilog, lwb); 2002 2003 lr = &itx->itx_lr; 2004 lrw = (lr_write_t *)lr; 2005 2006 /* 2007 * A commit itx doesn't represent any on-disk state; instead 2008 * it's simply used as a place holder on the commit list, and 2009 * provides a mechanism for attaching a "commit waiter" onto the 2010 * correct lwb (such that the waiter can be signalled upon 2011 * completion of that lwb). Thus, we don't process this itx's 2012 * log record if it's a commit itx (these itx's don't have log 2013 * records), and instead link the itx's waiter onto the lwb's 2014 * list of waiters. 2015 * 2016 * For more details, see the comment above zil_commit(). 2017 */ 2018 if (lr->lrc_txtype == TX_COMMIT) { 2019 zil_commit_waiter_link_lwb(itx->itx_private, lwb); 2020 list_insert_tail(&lwb->lwb_itxs, itx); 2021 return (lwb); 2022 } 2023 2024 if (lr->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY) { 2025 dlen = P2ROUNDUP_TYPED( 2026 lrw->lr_length, sizeof (uint64_t), uint64_t); 2027 } else { 2028 dlen = 0; 2029 } 2030 reclen = lr->lrc_reclen; 2031 zilog->zl_cur_used += (reclen + dlen); 2032 2033 cont: 2034 /* 2035 * If this record won't fit in the current log block, start a new one. 2036 * For WR_NEED_COPY optimize layout for minimal number of chunks. 2037 */ 2038 lwb_sp = lwb->lwb_nmax - lwb->lwb_nused; 2039 max_log_data = zil_max_log_data(zilog, sizeof (lr_write_t)); 2040 if (reclen > lwb_sp || (reclen + dlen > lwb_sp && 2041 lwb_sp < zil_max_waste_space(zilog) && 2042 (dlen % max_log_data == 0 || 2043 lwb_sp < reclen + dlen % max_log_data))) { 2044 list_insert_tail(ilwbs, lwb); 2045 lwb = zil_lwb_write_close(zilog, lwb, LWB_STATE_OPENED); 2046 if (lwb == NULL) 2047 return (NULL); 2048 lwb_sp = lwb->lwb_nmax - lwb->lwb_nused; 2049 2050 /* 2051 * There must be enough space in the new, empty log block to 2052 * hold reclen. For WR_COPIED, we need to fit the whole 2053 * record in one block, and reclen is the header size + the 2054 * data size. For WR_NEED_COPY, we can create multiple 2055 * records, splitting the data into multiple blocks, so we 2056 * only need to fit one word of data per block; in this case 2057 * reclen is just the header size (no data). 2058 */ 2059 ASSERT3U(reclen + MIN(dlen, sizeof (uint64_t)), <=, lwb_sp); 2060 } 2061 2062 dnow = MIN(dlen, lwb_sp - reclen); 2063 if (dlen > dnow) { 2064 ASSERT3U(lr->lrc_txtype, ==, TX_WRITE); 2065 ASSERT3U(itx->itx_wr_state, ==, WR_NEED_COPY); 2066 citx = zil_itx_clone(itx); 2067 clr = &citx->itx_lr; 2068 lr_write_t *clrw = (lr_write_t *)clr; 2069 clrw->lr_length = dnow; 2070 lrw->lr_offset += dnow; 2071 lrw->lr_length -= dnow; 2072 } else { 2073 citx = itx; 2074 clr = lr; 2075 } 2076 2077 /* 2078 * We're actually making an entry, so update lrc_seq to be the 2079 * log record sequence number. Note that this is generally not 2080 * equal to the itx sequence number because not all transactions 2081 * are synchronous, and sometimes spa_sync() gets there first. 2082 */ 2083 clr->lrc_seq = ++zilog->zl_lr_seq; 2084 2085 lwb->lwb_nused += reclen + dnow; 2086 ASSERT3U(lwb->lwb_nused, <=, lwb->lwb_nmax); 2087 ASSERT0(P2PHASE(lwb->lwb_nused, sizeof (uint64_t))); 2088 2089 zil_lwb_add_txg(lwb, lr->lrc_txg); 2090 list_insert_tail(&lwb->lwb_itxs, citx); 2091 2092 dlen -= dnow; 2093 if (dlen > 0) { 2094 zilog->zl_cur_used += reclen; 2095 goto cont; 2096 } 2097 2098 if (lr->lrc_txtype == TX_WRITE && 2099 lr->lrc_txg > spa_freeze_txg(zilog->zl_spa)) 2100 txg_wait_synced(zilog->zl_dmu_pool, lr->lrc_txg); 2101 2102 return (lwb); 2103 } 2104 2105 /* 2106 * Fill the actual transaction data into the lwb, following zil_lwb_assign(). 2107 * Does not require locking. 2108 */ 2109 static void 2110 zil_lwb_commit(zilog_t *zilog, lwb_t *lwb, itx_t *itx) 2111 { 2112 lr_t *lr, *lrb; 2113 lr_write_t *lrw, *lrwb; 2114 char *lr_buf; 2115 uint64_t dlen, reclen; 2116 2117 lr = &itx->itx_lr; 2118 lrw = (lr_write_t *)lr; 2119 2120 if (lr->lrc_txtype == TX_COMMIT) 2121 return; 2122 2123 if (lr->lrc_txtype == TX_WRITE && itx->itx_wr_state == WR_NEED_COPY) { 2124 dlen = P2ROUNDUP_TYPED( 2125 lrw->lr_length, sizeof (uint64_t), uint64_t); 2126 } else { 2127 dlen = 0; 2128 } 2129 reclen = lr->lrc_reclen; 2130 ASSERT3U(reclen + dlen, <=, lwb->lwb_nused - lwb->lwb_nfilled); 2131 2132 lr_buf = lwb->lwb_buf + lwb->lwb_nfilled; 2133 memcpy(lr_buf, lr, reclen); 2134 lrb = (lr_t *)lr_buf; /* Like lr, but inside lwb. */ 2135 lrwb = (lr_write_t *)lrb; /* Like lrw, but inside lwb. */ 2136 2137 ZIL_STAT_BUMP(zilog, zil_itx_count); 2138 2139 /* 2140 * If it's a write, fetch the data or get its blkptr as appropriate. 2141 */ 2142 if (lr->lrc_txtype == TX_WRITE) { 2143 if (itx->itx_wr_state == WR_COPIED) { 2144 ZIL_STAT_BUMP(zilog, zil_itx_copied_count); 2145 ZIL_STAT_INCR(zilog, zil_itx_copied_bytes, 2146 lrw->lr_length); 2147 } else { 2148 char *dbuf; 2149 int error; 2150 2151 if (itx->itx_wr_state == WR_NEED_COPY) { 2152 dbuf = lr_buf + reclen; 2153 lrb->lrc_reclen += dlen; 2154 ZIL_STAT_BUMP(zilog, zil_itx_needcopy_count); 2155 ZIL_STAT_INCR(zilog, zil_itx_needcopy_bytes, 2156 dlen); 2157 } else { 2158 ASSERT3S(itx->itx_wr_state, ==, WR_INDIRECT); 2159 dbuf = NULL; 2160 ZIL_STAT_BUMP(zilog, zil_itx_indirect_count); 2161 ZIL_STAT_INCR(zilog, zil_itx_indirect_bytes, 2162 lrw->lr_length); 2163 if (lwb->lwb_child_zio == NULL) { 2164 lwb->lwb_child_zio = zio_root( 2165 zilog->zl_spa, NULL, NULL, 2166 ZIO_FLAG_CANFAIL); 2167 } 2168 } 2169 2170 /* 2171 * The "lwb_child_zio" we pass in will become a child of 2172 * "lwb_write_zio", when one is created, so one will be 2173 * a parent of any zio's created by the "zl_get_data". 2174 * This way "lwb_write_zio" will first wait for children 2175 * block pointers before own writing, and then for their 2176 * writing completion before the vdev cache flushing. 2177 */ 2178 error = zilog->zl_get_data(itx->itx_private, 2179 itx->itx_gen, lrwb, dbuf, lwb, 2180 lwb->lwb_child_zio); 2181 if (dbuf != NULL && error == 0) { 2182 /* Zero any padding bytes in the last block. */ 2183 memset((char *)dbuf + lrwb->lr_length, 0, 2184 dlen - lrwb->lr_length); 2185 } 2186 2187 /* 2188 * Typically, the only return values we should see from 2189 * ->zl_get_data() are 0, EIO, ENOENT, EEXIST or 2190 * EALREADY. However, it is also possible to see other 2191 * error values such as ENOSPC or EINVAL from 2192 * dmu_read() -> dnode_hold() -> dnode_hold_impl() or 2193 * ENXIO as well as a multitude of others from the 2194 * block layer through dmu_buf_hold() -> dbuf_read() 2195 * -> zio_wait(), as well as through dmu_read() -> 2196 * dnode_hold() -> dnode_hold_impl() -> dbuf_read() -> 2197 * zio_wait(). When these errors happen, we can assume 2198 * that neither an immediate write nor an indirect 2199 * write occurred, so we need to fall back to 2200 * txg_wait_synced(). This is unusual, so we print to 2201 * dmesg whenever one of these errors occurs. 2202 */ 2203 switch (error) { 2204 case 0: 2205 break; 2206 default: 2207 cmn_err(CE_WARN, "zil_lwb_commit() received " 2208 "unexpected error %d from ->zl_get_data()" 2209 ". Falling back to txg_wait_synced().", 2210 error); 2211 zfs_fallthrough; 2212 case EIO: 2213 txg_wait_synced(zilog->zl_dmu_pool, 2214 lr->lrc_txg); 2215 zfs_fallthrough; 2216 case ENOENT: 2217 zfs_fallthrough; 2218 case EEXIST: 2219 zfs_fallthrough; 2220 case EALREADY: 2221 return; 2222 } 2223 } 2224 } 2225 2226 lwb->lwb_nfilled += reclen + dlen; 2227 ASSERT3S(lwb->lwb_nfilled, <=, lwb->lwb_nused); 2228 ASSERT0(P2PHASE(lwb->lwb_nfilled, sizeof (uint64_t))); 2229 } 2230 2231 itx_t * 2232 zil_itx_create(uint64_t txtype, size_t olrsize) 2233 { 2234 size_t itxsize, lrsize; 2235 itx_t *itx; 2236 2237 lrsize = P2ROUNDUP_TYPED(olrsize, sizeof (uint64_t), size_t); 2238 itxsize = offsetof(itx_t, itx_lr) + lrsize; 2239 2240 itx = zio_data_buf_alloc(itxsize); 2241 itx->itx_lr.lrc_txtype = txtype; 2242 itx->itx_lr.lrc_reclen = lrsize; 2243 itx->itx_lr.lrc_seq = 0; /* defensive */ 2244 memset((char *)&itx->itx_lr + olrsize, 0, lrsize - olrsize); 2245 itx->itx_sync = B_TRUE; /* default is synchronous */ 2246 itx->itx_callback = NULL; 2247 itx->itx_callback_data = NULL; 2248 itx->itx_size = itxsize; 2249 2250 return (itx); 2251 } 2252 2253 static itx_t * 2254 zil_itx_clone(itx_t *oitx) 2255 { 2256 itx_t *itx = zio_data_buf_alloc(oitx->itx_size); 2257 memcpy(itx, oitx, oitx->itx_size); 2258 itx->itx_callback = NULL; 2259 itx->itx_callback_data = NULL; 2260 return (itx); 2261 } 2262 2263 void 2264 zil_itx_destroy(itx_t *itx) 2265 { 2266 IMPLY(itx->itx_lr.lrc_txtype == TX_COMMIT, itx->itx_callback == NULL); 2267 IMPLY(itx->itx_callback != NULL, itx->itx_lr.lrc_txtype != TX_COMMIT); 2268 2269 if (itx->itx_callback != NULL) 2270 itx->itx_callback(itx->itx_callback_data); 2271 2272 zio_data_buf_free(itx, itx->itx_size); 2273 } 2274 2275 /* 2276 * Free up the sync and async itxs. The itxs_t has already been detached 2277 * so no locks are needed. 2278 */ 2279 static void 2280 zil_itxg_clean(void *arg) 2281 { 2282 itx_t *itx; 2283 list_t *list; 2284 avl_tree_t *t; 2285 void *cookie; 2286 itxs_t *itxs = arg; 2287 itx_async_node_t *ian; 2288 2289 list = &itxs->i_sync_list; 2290 while ((itx = list_remove_head(list)) != NULL) { 2291 /* 2292 * In the general case, commit itxs will not be found 2293 * here, as they'll be committed to an lwb via 2294 * zil_lwb_assign(), and free'd in that function. Having 2295 * said that, it is still possible for commit itxs to be 2296 * found here, due to the following race: 2297 * 2298 * - a thread calls zil_commit() which assigns the 2299 * commit itx to a per-txg i_sync_list 2300 * - zil_itxg_clean() is called (e.g. via spa_sync()) 2301 * while the waiter is still on the i_sync_list 2302 * 2303 * There's nothing to prevent syncing the txg while the 2304 * waiter is on the i_sync_list. This normally doesn't 2305 * happen because spa_sync() is slower than zil_commit(), 2306 * but if zil_commit() calls txg_wait_synced() (e.g. 2307 * because zil_create() or zil_commit_writer_stall() is 2308 * called) we will hit this case. 2309 */ 2310 if (itx->itx_lr.lrc_txtype == TX_COMMIT) 2311 zil_commit_waiter_skip(itx->itx_private); 2312 2313 zil_itx_destroy(itx); 2314 } 2315 2316 cookie = NULL; 2317 t = &itxs->i_async_tree; 2318 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) { 2319 list = &ian->ia_list; 2320 while ((itx = list_remove_head(list)) != NULL) { 2321 /* commit itxs should never be on the async lists. */ 2322 ASSERT3U(itx->itx_lr.lrc_txtype, !=, TX_COMMIT); 2323 zil_itx_destroy(itx); 2324 } 2325 list_destroy(list); 2326 kmem_free(ian, sizeof (itx_async_node_t)); 2327 } 2328 avl_destroy(t); 2329 2330 kmem_free(itxs, sizeof (itxs_t)); 2331 } 2332 2333 static int 2334 zil_aitx_compare(const void *x1, const void *x2) 2335 { 2336 const uint64_t o1 = ((itx_async_node_t *)x1)->ia_foid; 2337 const uint64_t o2 = ((itx_async_node_t *)x2)->ia_foid; 2338 2339 return (TREE_CMP(o1, o2)); 2340 } 2341 2342 /* 2343 * Remove all async itx with the given oid. 2344 */ 2345 void 2346 zil_remove_async(zilog_t *zilog, uint64_t oid) 2347 { 2348 uint64_t otxg, txg; 2349 itx_async_node_t *ian; 2350 avl_tree_t *t; 2351 avl_index_t where; 2352 list_t clean_list; 2353 itx_t *itx; 2354 2355 ASSERT(oid != 0); 2356 list_create(&clean_list, sizeof (itx_t), offsetof(itx_t, itx_node)); 2357 2358 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 2359 otxg = ZILTEST_TXG; 2360 else 2361 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 2362 2363 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 2364 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 2365 2366 mutex_enter(&itxg->itxg_lock); 2367 if (itxg->itxg_txg != txg) { 2368 mutex_exit(&itxg->itxg_lock); 2369 continue; 2370 } 2371 2372 /* 2373 * Locate the object node and append its list. 2374 */ 2375 t = &itxg->itxg_itxs->i_async_tree; 2376 ian = avl_find(t, &oid, &where); 2377 if (ian != NULL) 2378 list_move_tail(&clean_list, &ian->ia_list); 2379 mutex_exit(&itxg->itxg_lock); 2380 } 2381 while ((itx = list_remove_head(&clean_list)) != NULL) { 2382 /* commit itxs should never be on the async lists. */ 2383 ASSERT3U(itx->itx_lr.lrc_txtype, !=, TX_COMMIT); 2384 zil_itx_destroy(itx); 2385 } 2386 list_destroy(&clean_list); 2387 } 2388 2389 void 2390 zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx) 2391 { 2392 uint64_t txg; 2393 itxg_t *itxg; 2394 itxs_t *itxs, *clean = NULL; 2395 2396 /* 2397 * Ensure the data of a renamed file is committed before the rename. 2398 */ 2399 if ((itx->itx_lr.lrc_txtype & ~TX_CI) == TX_RENAME) 2400 zil_async_to_sync(zilog, itx->itx_oid); 2401 2402 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) 2403 txg = ZILTEST_TXG; 2404 else 2405 txg = dmu_tx_get_txg(tx); 2406 2407 itxg = &zilog->zl_itxg[txg & TXG_MASK]; 2408 mutex_enter(&itxg->itxg_lock); 2409 itxs = itxg->itxg_itxs; 2410 if (itxg->itxg_txg != txg) { 2411 if (itxs != NULL) { 2412 /* 2413 * The zil_clean callback hasn't got around to cleaning 2414 * this itxg. Save the itxs for release below. 2415 * This should be rare. 2416 */ 2417 zfs_dbgmsg("zil_itx_assign: missed itx cleanup for " 2418 "txg %llu", (u_longlong_t)itxg->itxg_txg); 2419 clean = itxg->itxg_itxs; 2420 } 2421 itxg->itxg_txg = txg; 2422 itxs = itxg->itxg_itxs = kmem_zalloc(sizeof (itxs_t), 2423 KM_SLEEP); 2424 2425 list_create(&itxs->i_sync_list, sizeof (itx_t), 2426 offsetof(itx_t, itx_node)); 2427 avl_create(&itxs->i_async_tree, zil_aitx_compare, 2428 sizeof (itx_async_node_t), 2429 offsetof(itx_async_node_t, ia_node)); 2430 } 2431 if (itx->itx_sync) { 2432 list_insert_tail(&itxs->i_sync_list, itx); 2433 } else { 2434 avl_tree_t *t = &itxs->i_async_tree; 2435 uint64_t foid = 2436 LR_FOID_GET_OBJ(((lr_ooo_t *)&itx->itx_lr)->lr_foid); 2437 itx_async_node_t *ian; 2438 avl_index_t where; 2439 2440 ian = avl_find(t, &foid, &where); 2441 if (ian == NULL) { 2442 ian = kmem_alloc(sizeof (itx_async_node_t), 2443 KM_SLEEP); 2444 list_create(&ian->ia_list, sizeof (itx_t), 2445 offsetof(itx_t, itx_node)); 2446 ian->ia_foid = foid; 2447 avl_insert(t, ian, where); 2448 } 2449 list_insert_tail(&ian->ia_list, itx); 2450 } 2451 2452 itx->itx_lr.lrc_txg = dmu_tx_get_txg(tx); 2453 2454 /* 2455 * We don't want to dirty the ZIL using ZILTEST_TXG, because 2456 * zil_clean() will never be called using ZILTEST_TXG. Thus, we 2457 * need to be careful to always dirty the ZIL using the "real" 2458 * TXG (not itxg_txg) even when the SPA is frozen. 2459 */ 2460 zilog_dirty(zilog, dmu_tx_get_txg(tx)); 2461 mutex_exit(&itxg->itxg_lock); 2462 2463 /* Release the old itxs now we've dropped the lock */ 2464 if (clean != NULL) 2465 zil_itxg_clean(clean); 2466 } 2467 2468 /* 2469 * If there are any in-memory intent log transactions which have now been 2470 * synced then start up a taskq to free them. We should only do this after we 2471 * have written out the uberblocks (i.e. txg has been committed) so that 2472 * don't inadvertently clean out in-memory log records that would be required 2473 * by zil_commit(). 2474 */ 2475 void 2476 zil_clean(zilog_t *zilog, uint64_t synced_txg) 2477 { 2478 itxg_t *itxg = &zilog->zl_itxg[synced_txg & TXG_MASK]; 2479 itxs_t *clean_me; 2480 2481 ASSERT3U(synced_txg, <, ZILTEST_TXG); 2482 2483 mutex_enter(&itxg->itxg_lock); 2484 if (itxg->itxg_itxs == NULL || itxg->itxg_txg == ZILTEST_TXG) { 2485 mutex_exit(&itxg->itxg_lock); 2486 return; 2487 } 2488 ASSERT3U(itxg->itxg_txg, <=, synced_txg); 2489 ASSERT3U(itxg->itxg_txg, !=, 0); 2490 clean_me = itxg->itxg_itxs; 2491 itxg->itxg_itxs = NULL; 2492 itxg->itxg_txg = 0; 2493 mutex_exit(&itxg->itxg_lock); 2494 /* 2495 * Preferably start a task queue to free up the old itxs but 2496 * if taskq_dispatch can't allocate resources to do that then 2497 * free it in-line. This should be rare. Note, using TQ_SLEEP 2498 * created a bad performance problem. 2499 */ 2500 ASSERT3P(zilog->zl_dmu_pool, !=, NULL); 2501 ASSERT3P(zilog->zl_dmu_pool->dp_zil_clean_taskq, !=, NULL); 2502 taskqid_t id = taskq_dispatch(zilog->zl_dmu_pool->dp_zil_clean_taskq, 2503 zil_itxg_clean, clean_me, TQ_NOSLEEP); 2504 if (id == TASKQID_INVALID) 2505 zil_itxg_clean(clean_me); 2506 } 2507 2508 /* 2509 * This function will traverse the queue of itxs that need to be 2510 * committed, and move them onto the ZIL's zl_itx_commit_list. 2511 */ 2512 static uint64_t 2513 zil_get_commit_list(zilog_t *zilog) 2514 { 2515 uint64_t otxg, txg, wtxg = 0; 2516 list_t *commit_list = &zilog->zl_itx_commit_list; 2517 2518 ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); 2519 2520 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 2521 otxg = ZILTEST_TXG; 2522 else 2523 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 2524 2525 /* 2526 * This is inherently racy, since there is nothing to prevent 2527 * the last synced txg from changing. That's okay since we'll 2528 * only commit things in the future. 2529 */ 2530 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 2531 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 2532 2533 mutex_enter(&itxg->itxg_lock); 2534 if (itxg->itxg_txg != txg) { 2535 mutex_exit(&itxg->itxg_lock); 2536 continue; 2537 } 2538 2539 /* 2540 * If we're adding itx records to the zl_itx_commit_list, 2541 * then the zil better be dirty in this "txg". We can assert 2542 * that here since we're holding the itxg_lock which will 2543 * prevent spa_sync from cleaning it. Once we add the itxs 2544 * to the zl_itx_commit_list we must commit it to disk even 2545 * if it's unnecessary (i.e. the txg was synced). 2546 */ 2547 ASSERT(zilog_is_dirty_in_txg(zilog, txg) || 2548 spa_freeze_txg(zilog->zl_spa) != UINT64_MAX); 2549 list_t *sync_list = &itxg->itxg_itxs->i_sync_list; 2550 if (unlikely(zilog->zl_suspend > 0)) { 2551 /* 2552 * ZIL was just suspended, but we lost the race. 2553 * Allow all earlier itxs to be committed, but ask 2554 * caller to do txg_wait_synced(txg) for any new. 2555 */ 2556 if (!list_is_empty(sync_list)) 2557 wtxg = MAX(wtxg, txg); 2558 } else { 2559 list_move_tail(commit_list, sync_list); 2560 } 2561 2562 mutex_exit(&itxg->itxg_lock); 2563 } 2564 return (wtxg); 2565 } 2566 2567 /* 2568 * Move the async itxs for a specified object to commit into sync lists. 2569 */ 2570 void 2571 zil_async_to_sync(zilog_t *zilog, uint64_t foid) 2572 { 2573 uint64_t otxg, txg; 2574 itx_async_node_t *ian; 2575 avl_tree_t *t; 2576 avl_index_t where; 2577 2578 if (spa_freeze_txg(zilog->zl_spa) != UINT64_MAX) /* ziltest support */ 2579 otxg = ZILTEST_TXG; 2580 else 2581 otxg = spa_last_synced_txg(zilog->zl_spa) + 1; 2582 2583 /* 2584 * This is inherently racy, since there is nothing to prevent 2585 * the last synced txg from changing. 2586 */ 2587 for (txg = otxg; txg < (otxg + TXG_CONCURRENT_STATES); txg++) { 2588 itxg_t *itxg = &zilog->zl_itxg[txg & TXG_MASK]; 2589 2590 mutex_enter(&itxg->itxg_lock); 2591 if (itxg->itxg_txg != txg) { 2592 mutex_exit(&itxg->itxg_lock); 2593 continue; 2594 } 2595 2596 /* 2597 * If a foid is specified then find that node and append its 2598 * list. Otherwise walk the tree appending all the lists 2599 * to the sync list. We add to the end rather than the 2600 * beginning to ensure the create has happened. 2601 */ 2602 t = &itxg->itxg_itxs->i_async_tree; 2603 if (foid != 0) { 2604 ian = avl_find(t, &foid, &where); 2605 if (ian != NULL) { 2606 list_move_tail(&itxg->itxg_itxs->i_sync_list, 2607 &ian->ia_list); 2608 } 2609 } else { 2610 void *cookie = NULL; 2611 2612 while ((ian = avl_destroy_nodes(t, &cookie)) != NULL) { 2613 list_move_tail(&itxg->itxg_itxs->i_sync_list, 2614 &ian->ia_list); 2615 list_destroy(&ian->ia_list); 2616 kmem_free(ian, sizeof (itx_async_node_t)); 2617 } 2618 } 2619 mutex_exit(&itxg->itxg_lock); 2620 } 2621 } 2622 2623 /* 2624 * This function will prune commit itxs that are at the head of the 2625 * commit list (it won't prune past the first non-commit itx), and 2626 * either: a) attach them to the last lwb that's still pending 2627 * completion, or b) skip them altogether. 2628 * 2629 * This is used as a performance optimization to prevent commit itxs 2630 * from generating new lwbs when it's unnecessary to do so. 2631 */ 2632 static void 2633 zil_prune_commit_list(zilog_t *zilog) 2634 { 2635 itx_t *itx; 2636 2637 ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); 2638 2639 while ((itx = list_head(&zilog->zl_itx_commit_list)) != NULL) { 2640 lr_t *lrc = &itx->itx_lr; 2641 if (lrc->lrc_txtype != TX_COMMIT) 2642 break; 2643 2644 mutex_enter(&zilog->zl_lock); 2645 2646 lwb_t *last_lwb = zilog->zl_last_lwb_opened; 2647 if (last_lwb == NULL || 2648 last_lwb->lwb_state == LWB_STATE_FLUSH_DONE) { 2649 /* 2650 * All of the itxs this waiter was waiting on 2651 * must have already completed (or there were 2652 * never any itx's for it to wait on), so it's 2653 * safe to skip this waiter and mark it done. 2654 */ 2655 zil_commit_waiter_skip(itx->itx_private); 2656 } else { 2657 zil_commit_waiter_link_lwb(itx->itx_private, last_lwb); 2658 } 2659 2660 mutex_exit(&zilog->zl_lock); 2661 2662 list_remove(&zilog->zl_itx_commit_list, itx); 2663 zil_itx_destroy(itx); 2664 } 2665 2666 IMPLY(itx != NULL, itx->itx_lr.lrc_txtype != TX_COMMIT); 2667 } 2668 2669 static void 2670 zil_commit_writer_stall(zilog_t *zilog) 2671 { 2672 /* 2673 * When zio_alloc_zil() fails to allocate the next lwb block on 2674 * disk, we must call txg_wait_synced() to ensure all of the 2675 * lwbs in the zilog's zl_lwb_list are synced and then freed (in 2676 * zil_sync()), such that any subsequent ZIL writer (i.e. a call 2677 * to zil_process_commit_list()) will have to call zil_create(), 2678 * and start a new ZIL chain. 2679 * 2680 * Since zil_alloc_zil() failed, the lwb that was previously 2681 * issued does not have a pointer to the "next" lwb on disk. 2682 * Thus, if another ZIL writer thread was to allocate the "next" 2683 * on-disk lwb, that block could be leaked in the event of a 2684 * crash (because the previous lwb on-disk would not point to 2685 * it). 2686 * 2687 * We must hold the zilog's zl_issuer_lock while we do this, to 2688 * ensure no new threads enter zil_process_commit_list() until 2689 * all lwb's in the zl_lwb_list have been synced and freed 2690 * (which is achieved via the txg_wait_synced() call). 2691 */ 2692 ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); 2693 txg_wait_synced(zilog->zl_dmu_pool, 0); 2694 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 2695 } 2696 2697 /* 2698 * This function will traverse the commit list, creating new lwbs as 2699 * needed, and committing the itxs from the commit list to these newly 2700 * created lwbs. Additionally, as a new lwb is created, the previous 2701 * lwb will be issued to the zio layer to be written to disk. 2702 */ 2703 static void 2704 zil_process_commit_list(zilog_t *zilog, zil_commit_waiter_t *zcw, list_t *ilwbs) 2705 { 2706 spa_t *spa = zilog->zl_spa; 2707 list_t nolwb_itxs; 2708 list_t nolwb_waiters; 2709 lwb_t *lwb, *plwb; 2710 itx_t *itx; 2711 boolean_t first = B_TRUE; 2712 2713 ASSERT(MUTEX_HELD(&zilog->zl_issuer_lock)); 2714 2715 /* 2716 * Return if there's nothing to commit before we dirty the fs by 2717 * calling zil_create(). 2718 */ 2719 if (list_is_empty(&zilog->zl_itx_commit_list)) 2720 return; 2721 2722 list_create(&nolwb_itxs, sizeof (itx_t), offsetof(itx_t, itx_node)); 2723 list_create(&nolwb_waiters, sizeof (zil_commit_waiter_t), 2724 offsetof(zil_commit_waiter_t, zcw_node)); 2725 2726 lwb = list_tail(&zilog->zl_lwb_list); 2727 if (lwb == NULL) { 2728 lwb = zil_create(zilog); 2729 } else { 2730 /* 2731 * Activate SPA_FEATURE_ZILSAXATTR for the cases where ZIL will 2732 * have already been created (zl_lwb_list not empty). 2733 */ 2734 zil_commit_activate_saxattr_feature(zilog); 2735 ASSERT(lwb->lwb_state == LWB_STATE_NEW || 2736 lwb->lwb_state == LWB_STATE_OPENED); 2737 first = (lwb->lwb_state == LWB_STATE_NEW) && 2738 ((plwb = list_prev(&zilog->zl_lwb_list, lwb)) == NULL || 2739 plwb->lwb_state == LWB_STATE_FLUSH_DONE); 2740 } 2741 2742 while ((itx = list_remove_head(&zilog->zl_itx_commit_list)) != NULL) { 2743 lr_t *lrc = &itx->itx_lr; 2744 uint64_t txg = lrc->lrc_txg; 2745 2746 ASSERT3U(txg, !=, 0); 2747 2748 if (lrc->lrc_txtype == TX_COMMIT) { 2749 DTRACE_PROBE2(zil__process__commit__itx, 2750 zilog_t *, zilog, itx_t *, itx); 2751 } else { 2752 DTRACE_PROBE2(zil__process__normal__itx, 2753 zilog_t *, zilog, itx_t *, itx); 2754 } 2755 2756 boolean_t synced = txg <= spa_last_synced_txg(spa); 2757 boolean_t frozen = txg > spa_freeze_txg(spa); 2758 2759 /* 2760 * If the txg of this itx has already been synced out, then 2761 * we don't need to commit this itx to an lwb. This is 2762 * because the data of this itx will have already been 2763 * written to the main pool. This is inherently racy, and 2764 * it's still ok to commit an itx whose txg has already 2765 * been synced; this will result in a write that's 2766 * unnecessary, but will do no harm. 2767 * 2768 * With that said, we always want to commit TX_COMMIT itxs 2769 * to an lwb, regardless of whether or not that itx's txg 2770 * has been synced out. We do this to ensure any OPENED lwb 2771 * will always have at least one zil_commit_waiter_t linked 2772 * to the lwb. 2773 * 2774 * As a counter-example, if we skipped TX_COMMIT itx's 2775 * whose txg had already been synced, the following 2776 * situation could occur if we happened to be racing with 2777 * spa_sync: 2778 * 2779 * 1. We commit a non-TX_COMMIT itx to an lwb, where the 2780 * itx's txg is 10 and the last synced txg is 9. 2781 * 2. spa_sync finishes syncing out txg 10. 2782 * 3. We move to the next itx in the list, it's a TX_COMMIT 2783 * whose txg is 10, so we skip it rather than committing 2784 * it to the lwb used in (1). 2785 * 2786 * If the itx that is skipped in (3) is the last TX_COMMIT 2787 * itx in the commit list, than it's possible for the lwb 2788 * used in (1) to remain in the OPENED state indefinitely. 2789 * 2790 * To prevent the above scenario from occurring, ensuring 2791 * that once an lwb is OPENED it will transition to ISSUED 2792 * and eventually DONE, we always commit TX_COMMIT itx's to 2793 * an lwb here, even if that itx's txg has already been 2794 * synced. 2795 * 2796 * Finally, if the pool is frozen, we _always_ commit the 2797 * itx. The point of freezing the pool is to prevent data 2798 * from being written to the main pool via spa_sync, and 2799 * instead rely solely on the ZIL to persistently store the 2800 * data; i.e. when the pool is frozen, the last synced txg 2801 * value can't be trusted. 2802 */ 2803 if (frozen || !synced || lrc->lrc_txtype == TX_COMMIT) { 2804 if (lwb != NULL) { 2805 lwb = zil_lwb_assign(zilog, lwb, itx, ilwbs); 2806 if (lwb == NULL) { 2807 list_insert_tail(&nolwb_itxs, itx); 2808 } else if ((zcw->zcw_lwb != NULL && 2809 zcw->zcw_lwb != lwb) || zcw->zcw_done) { 2810 /* 2811 * Our lwb is done, leave the rest of 2812 * itx list to somebody else who care. 2813 */ 2814 first = B_FALSE; 2815 break; 2816 } 2817 } else { 2818 if (lrc->lrc_txtype == TX_COMMIT) { 2819 zil_commit_waiter_link_nolwb( 2820 itx->itx_private, &nolwb_waiters); 2821 } 2822 list_insert_tail(&nolwb_itxs, itx); 2823 } 2824 } else { 2825 ASSERT3S(lrc->lrc_txtype, !=, TX_COMMIT); 2826 zil_itx_destroy(itx); 2827 } 2828 } 2829 2830 if (lwb == NULL) { 2831 /* 2832 * This indicates zio_alloc_zil() failed to allocate the 2833 * "next" lwb on-disk. When this happens, we must stall 2834 * the ZIL write pipeline; see the comment within 2835 * zil_commit_writer_stall() for more details. 2836 */ 2837 while ((lwb = list_remove_head(ilwbs)) != NULL) 2838 zil_lwb_write_issue(zilog, lwb); 2839 zil_commit_writer_stall(zilog); 2840 2841 /* 2842 * Additionally, we have to signal and mark the "nolwb" 2843 * waiters as "done" here, since without an lwb, we 2844 * can't do this via zil_lwb_flush_vdevs_done() like 2845 * normal. 2846 */ 2847 zil_commit_waiter_t *zcw; 2848 while ((zcw = list_remove_head(&nolwb_waiters)) != NULL) 2849 zil_commit_waiter_skip(zcw); 2850 2851 /* 2852 * And finally, we have to destroy the itx's that 2853 * couldn't be committed to an lwb; this will also call 2854 * the itx's callback if one exists for the itx. 2855 */ 2856 while ((itx = list_remove_head(&nolwb_itxs)) != NULL) 2857 zil_itx_destroy(itx); 2858 } else { 2859 ASSERT(list_is_empty(&nolwb_waiters)); 2860 ASSERT3P(lwb, !=, NULL); 2861 ASSERT(lwb->lwb_state == LWB_STATE_NEW || 2862 lwb->lwb_state == LWB_STATE_OPENED); 2863 2864 /* 2865 * At this point, the ZIL block pointed at by the "lwb" 2866 * variable is in "new" or "opened" state. 2867 * 2868 * If it's "new", then no itxs have been committed to it, so 2869 * there's no point in issuing its zio (i.e. it's "empty"). 2870 * 2871 * If it's "opened", then it contains one or more itxs that 2872 * eventually need to be committed to stable storage. In 2873 * this case we intentionally do not issue the lwb's zio 2874 * to disk yet, and instead rely on one of the following 2875 * two mechanisms for issuing the zio: 2876 * 2877 * 1. Ideally, there will be more ZIL activity occurring on 2878 * the system, such that this function will be immediately 2879 * called again by different thread and this lwb will be 2880 * closed by zil_lwb_assign(). This way, the lwb will be 2881 * "full" when it is issued to disk, and we'll make use of 2882 * the lwb's size the best we can. 2883 * 2884 * 2. If there isn't sufficient ZIL activity occurring on 2885 * the system, zil_commit_waiter() will close it and issue 2886 * the zio. If this occurs, the lwb is not guaranteed 2887 * to be "full" by the time its zio is issued, and means 2888 * the size of the lwb was "too large" given the amount 2889 * of ZIL activity occurring on the system at that time. 2890 * 2891 * We do this for a couple of reasons: 2892 * 2893 * 1. To try and reduce the number of IOPs needed to 2894 * write the same number of itxs. If an lwb has space 2895 * available in its buffer for more itxs, and more itxs 2896 * will be committed relatively soon (relative to the 2897 * latency of performing a write), then it's beneficial 2898 * to wait for these "next" itxs. This way, more itxs 2899 * can be committed to stable storage with fewer writes. 2900 * 2901 * 2. To try and use the largest lwb block size that the 2902 * incoming rate of itxs can support. Again, this is to 2903 * try and pack as many itxs into as few lwbs as 2904 * possible, without significantly impacting the latency 2905 * of each individual itx. 2906 * 2907 * If we had no already running or open LWBs, it can be 2908 * the workload is single-threaded. And if the ZIL write 2909 * latency is very small or if the LWB is almost full, it 2910 * may be cheaper to bypass the delay. 2911 */ 2912 if (lwb->lwb_state == LWB_STATE_OPENED && first) { 2913 hrtime_t sleep = zilog->zl_last_lwb_latency * 2914 zfs_commit_timeout_pct / 100; 2915 if (sleep < zil_min_commit_timeout || 2916 lwb->lwb_nmax - lwb->lwb_nused < 2917 lwb->lwb_nmax / 8) { 2918 list_insert_tail(ilwbs, lwb); 2919 lwb = zil_lwb_write_close(zilog, lwb, 2920 LWB_STATE_NEW); 2921 zilog->zl_cur_used = 0; 2922 if (lwb == NULL) { 2923 while ((lwb = list_remove_head(ilwbs)) 2924 != NULL) 2925 zil_lwb_write_issue(zilog, lwb); 2926 zil_commit_writer_stall(zilog); 2927 } 2928 } 2929 } 2930 } 2931 } 2932 2933 /* 2934 * This function is responsible for ensuring the passed in commit waiter 2935 * (and associated commit itx) is committed to an lwb. If the waiter is 2936 * not already committed to an lwb, all itxs in the zilog's queue of 2937 * itxs will be processed. The assumption is the passed in waiter's 2938 * commit itx will found in the queue just like the other non-commit 2939 * itxs, such that when the entire queue is processed, the waiter will 2940 * have been committed to an lwb. 2941 * 2942 * The lwb associated with the passed in waiter is not guaranteed to 2943 * have been issued by the time this function completes. If the lwb is 2944 * not issued, we rely on future calls to zil_commit_writer() to issue 2945 * the lwb, or the timeout mechanism found in zil_commit_waiter(). 2946 */ 2947 static uint64_t 2948 zil_commit_writer(zilog_t *zilog, zil_commit_waiter_t *zcw) 2949 { 2950 list_t ilwbs; 2951 lwb_t *lwb; 2952 uint64_t wtxg = 0; 2953 2954 ASSERT(!MUTEX_HELD(&zilog->zl_lock)); 2955 ASSERT(spa_writeable(zilog->zl_spa)); 2956 2957 list_create(&ilwbs, sizeof (lwb_t), offsetof(lwb_t, lwb_issue_node)); 2958 mutex_enter(&zilog->zl_issuer_lock); 2959 2960 if (zcw->zcw_lwb != NULL || zcw->zcw_done) { 2961 /* 2962 * It's possible that, while we were waiting to acquire 2963 * the "zl_issuer_lock", another thread committed this 2964 * waiter to an lwb. If that occurs, we bail out early, 2965 * without processing any of the zilog's queue of itxs. 2966 * 2967 * On certain workloads and system configurations, the 2968 * "zl_issuer_lock" can become highly contended. In an 2969 * attempt to reduce this contention, we immediately drop 2970 * the lock if the waiter has already been processed. 2971 * 2972 * We've measured this optimization to reduce CPU spent 2973 * contending on this lock by up to 5%, using a system 2974 * with 32 CPUs, low latency storage (~50 usec writes), 2975 * and 1024 threads performing sync writes. 2976 */ 2977 goto out; 2978 } 2979 2980 ZIL_STAT_BUMP(zilog, zil_commit_writer_count); 2981 2982 wtxg = zil_get_commit_list(zilog); 2983 zil_prune_commit_list(zilog); 2984 zil_process_commit_list(zilog, zcw, &ilwbs); 2985 2986 out: 2987 mutex_exit(&zilog->zl_issuer_lock); 2988 while ((lwb = list_remove_head(&ilwbs)) != NULL) 2989 zil_lwb_write_issue(zilog, lwb); 2990 list_destroy(&ilwbs); 2991 return (wtxg); 2992 } 2993 2994 static void 2995 zil_commit_waiter_timeout(zilog_t *zilog, zil_commit_waiter_t *zcw) 2996 { 2997 ASSERT(!MUTEX_HELD(&zilog->zl_issuer_lock)); 2998 ASSERT(MUTEX_HELD(&zcw->zcw_lock)); 2999 ASSERT3B(zcw->zcw_done, ==, B_FALSE); 3000 3001 lwb_t *lwb = zcw->zcw_lwb; 3002 ASSERT3P(lwb, !=, NULL); 3003 ASSERT3S(lwb->lwb_state, !=, LWB_STATE_NEW); 3004 3005 /* 3006 * If the lwb has already been issued by another thread, we can 3007 * immediately return since there's no work to be done (the 3008 * point of this function is to issue the lwb). Additionally, we 3009 * do this prior to acquiring the zl_issuer_lock, to avoid 3010 * acquiring it when it's not necessary to do so. 3011 */ 3012 if (lwb->lwb_state != LWB_STATE_OPENED) 3013 return; 3014 3015 /* 3016 * In order to call zil_lwb_write_close() we must hold the 3017 * zilog's "zl_issuer_lock". We can't simply acquire that lock, 3018 * since we're already holding the commit waiter's "zcw_lock", 3019 * and those two locks are acquired in the opposite order 3020 * elsewhere. 3021 */ 3022 mutex_exit(&zcw->zcw_lock); 3023 mutex_enter(&zilog->zl_issuer_lock); 3024 mutex_enter(&zcw->zcw_lock); 3025 3026 /* 3027 * Since we just dropped and re-acquired the commit waiter's 3028 * lock, we have to re-check to see if the waiter was marked 3029 * "done" during that process. If the waiter was marked "done", 3030 * the "lwb" pointer is no longer valid (it can be free'd after 3031 * the waiter is marked "done"), so without this check we could 3032 * wind up with a use-after-free error below. 3033 */ 3034 if (zcw->zcw_done) { 3035 mutex_exit(&zilog->zl_issuer_lock); 3036 return; 3037 } 3038 3039 ASSERT3P(lwb, ==, zcw->zcw_lwb); 3040 3041 /* 3042 * We've already checked this above, but since we hadn't acquired 3043 * the zilog's zl_issuer_lock, we have to perform this check a 3044 * second time while holding the lock. 3045 * 3046 * We don't need to hold the zl_lock since the lwb cannot transition 3047 * from OPENED to CLOSED while we hold the zl_issuer_lock. The lwb 3048 * _can_ transition from CLOSED to DONE, but it's OK to race with 3049 * that transition since we treat the lwb the same, whether it's in 3050 * the CLOSED, ISSUED or DONE states. 3051 * 3052 * The important thing, is we treat the lwb differently depending on 3053 * if it's OPENED or CLOSED, and block any other threads that might 3054 * attempt to close/issue this lwb. For that reason we hold the 3055 * zl_issuer_lock when checking the lwb_state; we must not call 3056 * zil_lwb_write_close() if the lwb had already been closed/issued. 3057 * 3058 * See the comment above the lwb_state_t structure definition for 3059 * more details on the lwb states, and locking requirements. 3060 */ 3061 if (lwb->lwb_state != LWB_STATE_OPENED) { 3062 mutex_exit(&zilog->zl_issuer_lock); 3063 return; 3064 } 3065 3066 /* 3067 * We do not need zcw_lock once we hold zl_issuer_lock and know lwb 3068 * is still open. But we have to drop it to avoid a deadlock in case 3069 * callback of zio issued by zil_lwb_write_issue() try to get it, 3070 * while zil_lwb_write_issue() is blocked on attempt to issue next 3071 * lwb it found in LWB_STATE_READY state. 3072 */ 3073 mutex_exit(&zcw->zcw_lock); 3074 3075 /* 3076 * As described in the comments above zil_commit_waiter() and 3077 * zil_process_commit_list(), we need to issue this lwb's zio 3078 * since we've reached the commit waiter's timeout and it still 3079 * hasn't been issued. 3080 */ 3081 lwb_t *nlwb = zil_lwb_write_close(zilog, lwb, LWB_STATE_NEW); 3082 3083 ASSERT3S(lwb->lwb_state, ==, LWB_STATE_CLOSED); 3084 3085 /* 3086 * Since the lwb's zio hadn't been issued by the time this thread 3087 * reached its timeout, we reset the zilog's "zl_cur_used" field 3088 * to influence the zil block size selection algorithm. 3089 * 3090 * By having to issue the lwb's zio here, it means the size of the 3091 * lwb was too large, given the incoming throughput of itxs. By 3092 * setting "zl_cur_used" to zero, we communicate this fact to the 3093 * block size selection algorithm, so it can take this information 3094 * into account, and potentially select a smaller size for the 3095 * next lwb block that is allocated. 3096 */ 3097 zilog->zl_cur_used = 0; 3098 3099 if (nlwb == NULL) { 3100 /* 3101 * When zil_lwb_write_close() returns NULL, this 3102 * indicates zio_alloc_zil() failed to allocate the 3103 * "next" lwb on-disk. When this occurs, the ZIL write 3104 * pipeline must be stalled; see the comment within the 3105 * zil_commit_writer_stall() function for more details. 3106 */ 3107 zil_lwb_write_issue(zilog, lwb); 3108 zil_commit_writer_stall(zilog); 3109 mutex_exit(&zilog->zl_issuer_lock); 3110 } else { 3111 mutex_exit(&zilog->zl_issuer_lock); 3112 zil_lwb_write_issue(zilog, lwb); 3113 } 3114 mutex_enter(&zcw->zcw_lock); 3115 } 3116 3117 /* 3118 * This function is responsible for performing the following two tasks: 3119 * 3120 * 1. its primary responsibility is to block until the given "commit 3121 * waiter" is considered "done". 3122 * 3123 * 2. its secondary responsibility is to issue the zio for the lwb that 3124 * the given "commit waiter" is waiting on, if this function has 3125 * waited "long enough" and the lwb is still in the "open" state. 3126 * 3127 * Given a sufficient amount of itxs being generated and written using 3128 * the ZIL, the lwb's zio will be issued via the zil_lwb_assign() 3129 * function. If this does not occur, this secondary responsibility will 3130 * ensure the lwb is issued even if there is not other synchronous 3131 * activity on the system. 3132 * 3133 * For more details, see zil_process_commit_list(); more specifically, 3134 * the comment at the bottom of that function. 3135 */ 3136 static void 3137 zil_commit_waiter(zilog_t *zilog, zil_commit_waiter_t *zcw) 3138 { 3139 ASSERT(!MUTEX_HELD(&zilog->zl_lock)); 3140 ASSERT(!MUTEX_HELD(&zilog->zl_issuer_lock)); 3141 ASSERT(spa_writeable(zilog->zl_spa)); 3142 3143 mutex_enter(&zcw->zcw_lock); 3144 3145 /* 3146 * The timeout is scaled based on the lwb latency to avoid 3147 * significantly impacting the latency of each individual itx. 3148 * For more details, see the comment at the bottom of the 3149 * zil_process_commit_list() function. 3150 */ 3151 int pct = MAX(zfs_commit_timeout_pct, 1); 3152 hrtime_t sleep = (zilog->zl_last_lwb_latency * pct) / 100; 3153 hrtime_t wakeup = gethrtime() + sleep; 3154 boolean_t timedout = B_FALSE; 3155 3156 while (!zcw->zcw_done) { 3157 ASSERT(MUTEX_HELD(&zcw->zcw_lock)); 3158 3159 lwb_t *lwb = zcw->zcw_lwb; 3160 3161 /* 3162 * Usually, the waiter will have a non-NULL lwb field here, 3163 * but it's possible for it to be NULL as a result of 3164 * zil_commit() racing with spa_sync(). 3165 * 3166 * When zil_clean() is called, it's possible for the itxg 3167 * list (which may be cleaned via a taskq) to contain 3168 * commit itxs. When this occurs, the commit waiters linked 3169 * off of these commit itxs will not be committed to an 3170 * lwb. Additionally, these commit waiters will not be 3171 * marked done until zil_commit_waiter_skip() is called via 3172 * zil_itxg_clean(). 3173 * 3174 * Thus, it's possible for this commit waiter (i.e. the 3175 * "zcw" variable) to be found in this "in between" state; 3176 * where it's "zcw_lwb" field is NULL, and it hasn't yet 3177 * been skipped, so it's "zcw_done" field is still B_FALSE. 3178 */ 3179 IMPLY(lwb != NULL, lwb->lwb_state != LWB_STATE_NEW); 3180 3181 if (lwb != NULL && lwb->lwb_state == LWB_STATE_OPENED) { 3182 ASSERT3B(timedout, ==, B_FALSE); 3183 3184 /* 3185 * If the lwb hasn't been issued yet, then we 3186 * need to wait with a timeout, in case this 3187 * function needs to issue the lwb after the 3188 * timeout is reached; responsibility (2) from 3189 * the comment above this function. 3190 */ 3191 int rc = cv_timedwait_hires(&zcw->zcw_cv, 3192 &zcw->zcw_lock, wakeup, USEC2NSEC(1), 3193 CALLOUT_FLAG_ABSOLUTE); 3194 3195 if (rc != -1 || zcw->zcw_done) 3196 continue; 3197 3198 timedout = B_TRUE; 3199 zil_commit_waiter_timeout(zilog, zcw); 3200 3201 if (!zcw->zcw_done) { 3202 /* 3203 * If the commit waiter has already been 3204 * marked "done", it's possible for the 3205 * waiter's lwb structure to have already 3206 * been freed. Thus, we can only reliably 3207 * make these assertions if the waiter 3208 * isn't done. 3209 */ 3210 ASSERT3P(lwb, ==, zcw->zcw_lwb); 3211 ASSERT3S(lwb->lwb_state, !=, LWB_STATE_OPENED); 3212 } 3213 } else { 3214 /* 3215 * If the lwb isn't open, then it must have already 3216 * been issued. In that case, there's no need to 3217 * use a timeout when waiting for the lwb to 3218 * complete. 3219 * 3220 * Additionally, if the lwb is NULL, the waiter 3221 * will soon be signaled and marked done via 3222 * zil_clean() and zil_itxg_clean(), so no timeout 3223 * is required. 3224 */ 3225 3226 IMPLY(lwb != NULL, 3227 lwb->lwb_state == LWB_STATE_CLOSED || 3228 lwb->lwb_state == LWB_STATE_READY || 3229 lwb->lwb_state == LWB_STATE_ISSUED || 3230 lwb->lwb_state == LWB_STATE_WRITE_DONE || 3231 lwb->lwb_state == LWB_STATE_FLUSH_DONE); 3232 cv_wait(&zcw->zcw_cv, &zcw->zcw_lock); 3233 } 3234 } 3235 3236 mutex_exit(&zcw->zcw_lock); 3237 } 3238 3239 static zil_commit_waiter_t * 3240 zil_alloc_commit_waiter(void) 3241 { 3242 zil_commit_waiter_t *zcw = kmem_cache_alloc(zil_zcw_cache, KM_SLEEP); 3243 3244 cv_init(&zcw->zcw_cv, NULL, CV_DEFAULT, NULL); 3245 mutex_init(&zcw->zcw_lock, NULL, MUTEX_DEFAULT, NULL); 3246 list_link_init(&zcw->zcw_node); 3247 zcw->zcw_lwb = NULL; 3248 zcw->zcw_done = B_FALSE; 3249 zcw->zcw_zio_error = 0; 3250 3251 return (zcw); 3252 } 3253 3254 static void 3255 zil_free_commit_waiter(zil_commit_waiter_t *zcw) 3256 { 3257 ASSERT(!list_link_active(&zcw->zcw_node)); 3258 ASSERT3P(zcw->zcw_lwb, ==, NULL); 3259 ASSERT3B(zcw->zcw_done, ==, B_TRUE); 3260 mutex_destroy(&zcw->zcw_lock); 3261 cv_destroy(&zcw->zcw_cv); 3262 kmem_cache_free(zil_zcw_cache, zcw); 3263 } 3264 3265 /* 3266 * This function is used to create a TX_COMMIT itx and assign it. This 3267 * way, it will be linked into the ZIL's list of synchronous itxs, and 3268 * then later committed to an lwb (or skipped) when 3269 * zil_process_commit_list() is called. 3270 */ 3271 static void 3272 zil_commit_itx_assign(zilog_t *zilog, zil_commit_waiter_t *zcw) 3273 { 3274 dmu_tx_t *tx = dmu_tx_create(zilog->zl_os); 3275 3276 /* 3277 * Since we are not going to create any new dirty data, and we 3278 * can even help with clearing the existing dirty data, we 3279 * should not be subject to the dirty data based delays. We 3280 * use TXG_NOTHROTTLE to bypass the delay mechanism. 3281 */ 3282 VERIFY0(dmu_tx_assign(tx, TXG_WAIT | TXG_NOTHROTTLE)); 3283 3284 itx_t *itx = zil_itx_create(TX_COMMIT, sizeof (lr_t)); 3285 itx->itx_sync = B_TRUE; 3286 itx->itx_private = zcw; 3287 3288 zil_itx_assign(zilog, itx, tx); 3289 3290 dmu_tx_commit(tx); 3291 } 3292 3293 /* 3294 * Commit ZFS Intent Log transactions (itxs) to stable storage. 3295 * 3296 * When writing ZIL transactions to the on-disk representation of the 3297 * ZIL, the itxs are committed to a Log Write Block (lwb). Multiple 3298 * itxs can be committed to a single lwb. Once a lwb is written and 3299 * committed to stable storage (i.e. the lwb is written, and vdevs have 3300 * been flushed), each itx that was committed to that lwb is also 3301 * considered to be committed to stable storage. 3302 * 3303 * When an itx is committed to an lwb, the log record (lr_t) contained 3304 * by the itx is copied into the lwb's zio buffer, and once this buffer 3305 * is written to disk, it becomes an on-disk ZIL block. 3306 * 3307 * As itxs are generated, they're inserted into the ZIL's queue of 3308 * uncommitted itxs. The semantics of zil_commit() are such that it will 3309 * block until all itxs that were in the queue when it was called, are 3310 * committed to stable storage. 3311 * 3312 * If "foid" is zero, this means all "synchronous" and "asynchronous" 3313 * itxs, for all objects in the dataset, will be committed to stable 3314 * storage prior to zil_commit() returning. If "foid" is non-zero, all 3315 * "synchronous" itxs for all objects, but only "asynchronous" itxs 3316 * that correspond to the foid passed in, will be committed to stable 3317 * storage prior to zil_commit() returning. 3318 * 3319 * Generally speaking, when zil_commit() is called, the consumer doesn't 3320 * actually care about _all_ of the uncommitted itxs. Instead, they're 3321 * simply trying to waiting for a specific itx to be committed to disk, 3322 * but the interface(s) for interacting with the ZIL don't allow such 3323 * fine-grained communication. A better interface would allow a consumer 3324 * to create and assign an itx, and then pass a reference to this itx to 3325 * zil_commit(); such that zil_commit() would return as soon as that 3326 * specific itx was committed to disk (instead of waiting for _all_ 3327 * itxs to be committed). 3328 * 3329 * When a thread calls zil_commit() a special "commit itx" will be 3330 * generated, along with a corresponding "waiter" for this commit itx. 3331 * zil_commit() will wait on this waiter's CV, such that when the waiter 3332 * is marked done, and signaled, zil_commit() will return. 3333 * 3334 * This commit itx is inserted into the queue of uncommitted itxs. This 3335 * provides an easy mechanism for determining which itxs were in the 3336 * queue prior to zil_commit() having been called, and which itxs were 3337 * added after zil_commit() was called. 3338 * 3339 * The commit itx is special; it doesn't have any on-disk representation. 3340 * When a commit itx is "committed" to an lwb, the waiter associated 3341 * with it is linked onto the lwb's list of waiters. Then, when that lwb 3342 * completes, each waiter on the lwb's list is marked done and signaled 3343 * -- allowing the thread waiting on the waiter to return from zil_commit(). 3344 * 3345 * It's important to point out a few critical factors that allow us 3346 * to make use of the commit itxs, commit waiters, per-lwb lists of 3347 * commit waiters, and zio completion callbacks like we're doing: 3348 * 3349 * 1. The list of waiters for each lwb is traversed, and each commit 3350 * waiter is marked "done" and signaled, in the zio completion 3351 * callback of the lwb's zio[*]. 3352 * 3353 * * Actually, the waiters are signaled in the zio completion 3354 * callback of the root zio for the DKIOCFLUSHWRITECACHE commands 3355 * that are sent to the vdevs upon completion of the lwb zio. 3356 * 3357 * 2. When the itxs are inserted into the ZIL's queue of uncommitted 3358 * itxs, the order in which they are inserted is preserved[*]; as 3359 * itxs are added to the queue, they are added to the tail of 3360 * in-memory linked lists. 3361 * 3362 * When committing the itxs to lwbs (to be written to disk), they 3363 * are committed in the same order in which the itxs were added to 3364 * the uncommitted queue's linked list(s); i.e. the linked list of 3365 * itxs to commit is traversed from head to tail, and each itx is 3366 * committed to an lwb in that order. 3367 * 3368 * * To clarify: 3369 * 3370 * - the order of "sync" itxs is preserved w.r.t. other 3371 * "sync" itxs, regardless of the corresponding objects. 3372 * - the order of "async" itxs is preserved w.r.t. other 3373 * "async" itxs corresponding to the same object. 3374 * - the order of "async" itxs is *not* preserved w.r.t. other 3375 * "async" itxs corresponding to different objects. 3376 * - the order of "sync" itxs w.r.t. "async" itxs (or vice 3377 * versa) is *not* preserved, even for itxs that correspond 3378 * to the same object. 3379 * 3380 * For more details, see: zil_itx_assign(), zil_async_to_sync(), 3381 * zil_get_commit_list(), and zil_process_commit_list(). 3382 * 3383 * 3. The lwbs represent a linked list of blocks on disk. Thus, any 3384 * lwb cannot be considered committed to stable storage, until its 3385 * "previous" lwb is also committed to stable storage. This fact, 3386 * coupled with the fact described above, means that itxs are 3387 * committed in (roughly) the order in which they were generated. 3388 * This is essential because itxs are dependent on prior itxs. 3389 * Thus, we *must not* deem an itx as being committed to stable 3390 * storage, until *all* prior itxs have also been committed to 3391 * stable storage. 3392 * 3393 * To enforce this ordering of lwb zio's, while still leveraging as 3394 * much of the underlying storage performance as possible, we rely 3395 * on two fundamental concepts: 3396 * 3397 * 1. The creation and issuance of lwb zio's is protected by 3398 * the zilog's "zl_issuer_lock", which ensures only a single 3399 * thread is creating and/or issuing lwb's at a time 3400 * 2. The "previous" lwb is a child of the "current" lwb 3401 * (leveraging the zio parent-child dependency graph) 3402 * 3403 * By relying on this parent-child zio relationship, we can have 3404 * many lwb zio's concurrently issued to the underlying storage, 3405 * but the order in which they complete will be the same order in 3406 * which they were created. 3407 */ 3408 void 3409 zil_commit(zilog_t *zilog, uint64_t foid) 3410 { 3411 /* 3412 * We should never attempt to call zil_commit on a snapshot for 3413 * a couple of reasons: 3414 * 3415 * 1. A snapshot may never be modified, thus it cannot have any 3416 * in-flight itxs that would have modified the dataset. 3417 * 3418 * 2. By design, when zil_commit() is called, a commit itx will 3419 * be assigned to this zilog; as a result, the zilog will be 3420 * dirtied. We must not dirty the zilog of a snapshot; there's 3421 * checks in the code that enforce this invariant, and will 3422 * cause a panic if it's not upheld. 3423 */ 3424 ASSERT3B(dmu_objset_is_snapshot(zilog->zl_os), ==, B_FALSE); 3425 3426 if (zilog->zl_sync == ZFS_SYNC_DISABLED) 3427 return; 3428 3429 if (!spa_writeable(zilog->zl_spa)) { 3430 /* 3431 * If the SPA is not writable, there should never be any 3432 * pending itxs waiting to be committed to disk. If that 3433 * weren't true, we'd skip writing those itxs out, and 3434 * would break the semantics of zil_commit(); thus, we're 3435 * verifying that truth before we return to the caller. 3436 */ 3437 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 3438 ASSERT3P(zilog->zl_last_lwb_opened, ==, NULL); 3439 for (int i = 0; i < TXG_SIZE; i++) 3440 ASSERT3P(zilog->zl_itxg[i].itxg_itxs, ==, NULL); 3441 return; 3442 } 3443 3444 /* 3445 * If the ZIL is suspended, we don't want to dirty it by calling 3446 * zil_commit_itx_assign() below, nor can we write out 3447 * lwbs like would be done in zil_commit_write(). Thus, we 3448 * simply rely on txg_wait_synced() to maintain the necessary 3449 * semantics, and avoid calling those functions altogether. 3450 */ 3451 if (zilog->zl_suspend > 0) { 3452 txg_wait_synced(zilog->zl_dmu_pool, 0); 3453 return; 3454 } 3455 3456 zil_commit_impl(zilog, foid); 3457 } 3458 3459 void 3460 zil_commit_impl(zilog_t *zilog, uint64_t foid) 3461 { 3462 ZIL_STAT_BUMP(zilog, zil_commit_count); 3463 3464 /* 3465 * Move the "async" itxs for the specified foid to the "sync" 3466 * queues, such that they will be later committed (or skipped) 3467 * to an lwb when zil_process_commit_list() is called. 3468 * 3469 * Since these "async" itxs must be committed prior to this 3470 * call to zil_commit returning, we must perform this operation 3471 * before we call zil_commit_itx_assign(). 3472 */ 3473 zil_async_to_sync(zilog, foid); 3474 3475 /* 3476 * We allocate a new "waiter" structure which will initially be 3477 * linked to the commit itx using the itx's "itx_private" field. 3478 * Since the commit itx doesn't represent any on-disk state, 3479 * when it's committed to an lwb, rather than copying the its 3480 * lr_t into the lwb's buffer, the commit itx's "waiter" will be 3481 * added to the lwb's list of waiters. Then, when the lwb is 3482 * committed to stable storage, each waiter in the lwb's list of 3483 * waiters will be marked "done", and signalled. 3484 * 3485 * We must create the waiter and assign the commit itx prior to 3486 * calling zil_commit_writer(), or else our specific commit itx 3487 * is not guaranteed to be committed to an lwb prior to calling 3488 * zil_commit_waiter(). 3489 */ 3490 zil_commit_waiter_t *zcw = zil_alloc_commit_waiter(); 3491 zil_commit_itx_assign(zilog, zcw); 3492 3493 uint64_t wtxg = zil_commit_writer(zilog, zcw); 3494 zil_commit_waiter(zilog, zcw); 3495 3496 if (zcw->zcw_zio_error != 0) { 3497 /* 3498 * If there was an error writing out the ZIL blocks that 3499 * this thread is waiting on, then we fallback to 3500 * relying on spa_sync() to write out the data this 3501 * thread is waiting on. Obviously this has performance 3502 * implications, but the expectation is for this to be 3503 * an exceptional case, and shouldn't occur often. 3504 */ 3505 DTRACE_PROBE2(zil__commit__io__error, 3506 zilog_t *, zilog, zil_commit_waiter_t *, zcw); 3507 txg_wait_synced(zilog->zl_dmu_pool, 0); 3508 } else if (wtxg != 0) { 3509 txg_wait_synced(zilog->zl_dmu_pool, wtxg); 3510 } 3511 3512 zil_free_commit_waiter(zcw); 3513 } 3514 3515 /* 3516 * Called in syncing context to free committed log blocks and update log header. 3517 */ 3518 void 3519 zil_sync(zilog_t *zilog, dmu_tx_t *tx) 3520 { 3521 zil_header_t *zh = zil_header_in_syncing_context(zilog); 3522 uint64_t txg = dmu_tx_get_txg(tx); 3523 spa_t *spa = zilog->zl_spa; 3524 uint64_t *replayed_seq = &zilog->zl_replayed_seq[txg & TXG_MASK]; 3525 lwb_t *lwb; 3526 3527 /* 3528 * We don't zero out zl_destroy_txg, so make sure we don't try 3529 * to destroy it twice. 3530 */ 3531 if (spa_sync_pass(spa) != 1) 3532 return; 3533 3534 zil_lwb_flush_wait_all(zilog, txg); 3535 3536 mutex_enter(&zilog->zl_lock); 3537 3538 ASSERT(zilog->zl_stop_sync == 0); 3539 3540 if (*replayed_seq != 0) { 3541 ASSERT(zh->zh_replay_seq < *replayed_seq); 3542 zh->zh_replay_seq = *replayed_seq; 3543 *replayed_seq = 0; 3544 } 3545 3546 if (zilog->zl_destroy_txg == txg) { 3547 blkptr_t blk = zh->zh_log; 3548 dsl_dataset_t *ds = dmu_objset_ds(zilog->zl_os); 3549 3550 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 3551 3552 memset(zh, 0, sizeof (zil_header_t)); 3553 memset(zilog->zl_replayed_seq, 0, 3554 sizeof (zilog->zl_replayed_seq)); 3555 3556 if (zilog->zl_keep_first) { 3557 /* 3558 * If this block was part of log chain that couldn't 3559 * be claimed because a device was missing during 3560 * zil_claim(), but that device later returns, 3561 * then this block could erroneously appear valid. 3562 * To guard against this, assign a new GUID to the new 3563 * log chain so it doesn't matter what blk points to. 3564 */ 3565 zil_init_log_chain(zilog, &blk); 3566 zh->zh_log = blk; 3567 } else { 3568 /* 3569 * A destroyed ZIL chain can't contain any TX_SETSAXATTR 3570 * records. So, deactivate the feature for this dataset. 3571 * We activate it again when we start a new ZIL chain. 3572 */ 3573 if (dsl_dataset_feature_is_active(ds, 3574 SPA_FEATURE_ZILSAXATTR)) 3575 dsl_dataset_deactivate_feature(ds, 3576 SPA_FEATURE_ZILSAXATTR, tx); 3577 } 3578 } 3579 3580 while ((lwb = list_head(&zilog->zl_lwb_list)) != NULL) { 3581 zh->zh_log = lwb->lwb_blk; 3582 if (lwb->lwb_state != LWB_STATE_FLUSH_DONE || 3583 lwb->lwb_alloc_txg > txg || lwb->lwb_max_txg > txg) 3584 break; 3585 list_remove(&zilog->zl_lwb_list, lwb); 3586 if (!BP_IS_HOLE(&lwb->lwb_blk)) 3587 zio_free(spa, txg, &lwb->lwb_blk); 3588 zil_free_lwb(zilog, lwb); 3589 3590 /* 3591 * If we don't have anything left in the lwb list then 3592 * we've had an allocation failure and we need to zero 3593 * out the zil_header blkptr so that we don't end 3594 * up freeing the same block twice. 3595 */ 3596 if (list_is_empty(&zilog->zl_lwb_list)) 3597 BP_ZERO(&zh->zh_log); 3598 } 3599 3600 mutex_exit(&zilog->zl_lock); 3601 } 3602 3603 static int 3604 zil_lwb_cons(void *vbuf, void *unused, int kmflag) 3605 { 3606 (void) unused, (void) kmflag; 3607 lwb_t *lwb = vbuf; 3608 list_create(&lwb->lwb_itxs, sizeof (itx_t), offsetof(itx_t, itx_node)); 3609 list_create(&lwb->lwb_waiters, sizeof (zil_commit_waiter_t), 3610 offsetof(zil_commit_waiter_t, zcw_node)); 3611 avl_create(&lwb->lwb_vdev_tree, zil_lwb_vdev_compare, 3612 sizeof (zil_vdev_node_t), offsetof(zil_vdev_node_t, zv_node)); 3613 mutex_init(&lwb->lwb_vdev_lock, NULL, MUTEX_DEFAULT, NULL); 3614 return (0); 3615 } 3616 3617 static void 3618 zil_lwb_dest(void *vbuf, void *unused) 3619 { 3620 (void) unused; 3621 lwb_t *lwb = vbuf; 3622 mutex_destroy(&lwb->lwb_vdev_lock); 3623 avl_destroy(&lwb->lwb_vdev_tree); 3624 list_destroy(&lwb->lwb_waiters); 3625 list_destroy(&lwb->lwb_itxs); 3626 } 3627 3628 void 3629 zil_init(void) 3630 { 3631 zil_lwb_cache = kmem_cache_create("zil_lwb_cache", 3632 sizeof (lwb_t), 0, zil_lwb_cons, zil_lwb_dest, NULL, NULL, NULL, 0); 3633 3634 zil_zcw_cache = kmem_cache_create("zil_zcw_cache", 3635 sizeof (zil_commit_waiter_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 3636 3637 zil_sums_init(&zil_sums_global); 3638 zil_kstats_global = kstat_create("zfs", 0, "zil", "misc", 3639 KSTAT_TYPE_NAMED, sizeof (zil_stats) / sizeof (kstat_named_t), 3640 KSTAT_FLAG_VIRTUAL); 3641 3642 if (zil_kstats_global != NULL) { 3643 zil_kstats_global->ks_data = &zil_stats; 3644 zil_kstats_global->ks_update = zil_kstats_global_update; 3645 zil_kstats_global->ks_private = NULL; 3646 kstat_install(zil_kstats_global); 3647 } 3648 } 3649 3650 void 3651 zil_fini(void) 3652 { 3653 kmem_cache_destroy(zil_zcw_cache); 3654 kmem_cache_destroy(zil_lwb_cache); 3655 3656 if (zil_kstats_global != NULL) { 3657 kstat_delete(zil_kstats_global); 3658 zil_kstats_global = NULL; 3659 } 3660 3661 zil_sums_fini(&zil_sums_global); 3662 } 3663 3664 void 3665 zil_set_sync(zilog_t *zilog, uint64_t sync) 3666 { 3667 zilog->zl_sync = sync; 3668 } 3669 3670 void 3671 zil_set_logbias(zilog_t *zilog, uint64_t logbias) 3672 { 3673 zilog->zl_logbias = logbias; 3674 } 3675 3676 zilog_t * 3677 zil_alloc(objset_t *os, zil_header_t *zh_phys) 3678 { 3679 zilog_t *zilog; 3680 3681 zilog = kmem_zalloc(sizeof (zilog_t), KM_SLEEP); 3682 3683 zilog->zl_header = zh_phys; 3684 zilog->zl_os = os; 3685 zilog->zl_spa = dmu_objset_spa(os); 3686 zilog->zl_dmu_pool = dmu_objset_pool(os); 3687 zilog->zl_destroy_txg = TXG_INITIAL - 1; 3688 zilog->zl_logbias = dmu_objset_logbias(os); 3689 zilog->zl_sync = dmu_objset_syncprop(os); 3690 zilog->zl_dirty_max_txg = 0; 3691 zilog->zl_last_lwb_opened = NULL; 3692 zilog->zl_last_lwb_latency = 0; 3693 zilog->zl_max_block_size = zil_maxblocksize; 3694 3695 mutex_init(&zilog->zl_lock, NULL, MUTEX_DEFAULT, NULL); 3696 mutex_init(&zilog->zl_issuer_lock, NULL, MUTEX_DEFAULT, NULL); 3697 mutex_init(&zilog->zl_lwb_io_lock, NULL, MUTEX_DEFAULT, NULL); 3698 3699 for (int i = 0; i < TXG_SIZE; i++) { 3700 mutex_init(&zilog->zl_itxg[i].itxg_lock, NULL, 3701 MUTEX_DEFAULT, NULL); 3702 } 3703 3704 list_create(&zilog->zl_lwb_list, sizeof (lwb_t), 3705 offsetof(lwb_t, lwb_node)); 3706 3707 list_create(&zilog->zl_itx_commit_list, sizeof (itx_t), 3708 offsetof(itx_t, itx_node)); 3709 3710 cv_init(&zilog->zl_cv_suspend, NULL, CV_DEFAULT, NULL); 3711 cv_init(&zilog->zl_lwb_io_cv, NULL, CV_DEFAULT, NULL); 3712 3713 return (zilog); 3714 } 3715 3716 void 3717 zil_free(zilog_t *zilog) 3718 { 3719 int i; 3720 3721 zilog->zl_stop_sync = 1; 3722 3723 ASSERT0(zilog->zl_suspend); 3724 ASSERT0(zilog->zl_suspending); 3725 3726 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 3727 list_destroy(&zilog->zl_lwb_list); 3728 3729 ASSERT(list_is_empty(&zilog->zl_itx_commit_list)); 3730 list_destroy(&zilog->zl_itx_commit_list); 3731 3732 for (i = 0; i < TXG_SIZE; i++) { 3733 /* 3734 * It's possible for an itx to be generated that doesn't dirty 3735 * a txg (e.g. ztest TX_TRUNCATE). So there's no zil_clean() 3736 * callback to remove the entry. We remove those here. 3737 * 3738 * Also free up the ziltest itxs. 3739 */ 3740 if (zilog->zl_itxg[i].itxg_itxs) 3741 zil_itxg_clean(zilog->zl_itxg[i].itxg_itxs); 3742 mutex_destroy(&zilog->zl_itxg[i].itxg_lock); 3743 } 3744 3745 mutex_destroy(&zilog->zl_issuer_lock); 3746 mutex_destroy(&zilog->zl_lock); 3747 mutex_destroy(&zilog->zl_lwb_io_lock); 3748 3749 cv_destroy(&zilog->zl_cv_suspend); 3750 cv_destroy(&zilog->zl_lwb_io_cv); 3751 3752 kmem_free(zilog, sizeof (zilog_t)); 3753 } 3754 3755 /* 3756 * Open an intent log. 3757 */ 3758 zilog_t * 3759 zil_open(objset_t *os, zil_get_data_t *get_data, zil_sums_t *zil_sums) 3760 { 3761 zilog_t *zilog = dmu_objset_zil(os); 3762 3763 ASSERT3P(zilog->zl_get_data, ==, NULL); 3764 ASSERT3P(zilog->zl_last_lwb_opened, ==, NULL); 3765 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 3766 3767 zilog->zl_get_data = get_data; 3768 zilog->zl_sums = zil_sums; 3769 3770 return (zilog); 3771 } 3772 3773 /* 3774 * Close an intent log. 3775 */ 3776 void 3777 zil_close(zilog_t *zilog) 3778 { 3779 lwb_t *lwb; 3780 uint64_t txg; 3781 3782 if (!dmu_objset_is_snapshot(zilog->zl_os)) { 3783 zil_commit(zilog, 0); 3784 } else { 3785 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 3786 ASSERT0(zilog->zl_dirty_max_txg); 3787 ASSERT3B(zilog_is_dirty(zilog), ==, B_FALSE); 3788 } 3789 3790 mutex_enter(&zilog->zl_lock); 3791 txg = zilog->zl_dirty_max_txg; 3792 lwb = list_tail(&zilog->zl_lwb_list); 3793 if (lwb != NULL) { 3794 txg = MAX(txg, lwb->lwb_alloc_txg); 3795 txg = MAX(txg, lwb->lwb_max_txg); 3796 } 3797 mutex_exit(&zilog->zl_lock); 3798 3799 /* 3800 * zl_lwb_max_issued_txg may be larger than lwb_max_txg. It depends 3801 * on the time when the dmu_tx transaction is assigned in 3802 * zil_lwb_write_issue(). 3803 */ 3804 mutex_enter(&zilog->zl_lwb_io_lock); 3805 txg = MAX(zilog->zl_lwb_max_issued_txg, txg); 3806 mutex_exit(&zilog->zl_lwb_io_lock); 3807 3808 /* 3809 * We need to use txg_wait_synced() to wait until that txg is synced. 3810 * zil_sync() will guarantee all lwbs up to that txg have been 3811 * written out, flushed, and cleaned. 3812 */ 3813 if (txg != 0) 3814 txg_wait_synced(zilog->zl_dmu_pool, txg); 3815 3816 if (zilog_is_dirty(zilog)) 3817 zfs_dbgmsg("zil (%px) is dirty, txg %llu", zilog, 3818 (u_longlong_t)txg); 3819 if (txg < spa_freeze_txg(zilog->zl_spa)) 3820 VERIFY(!zilog_is_dirty(zilog)); 3821 3822 zilog->zl_get_data = NULL; 3823 3824 /* 3825 * We should have only one lwb left on the list; remove it now. 3826 */ 3827 mutex_enter(&zilog->zl_lock); 3828 lwb = list_remove_head(&zilog->zl_lwb_list); 3829 if (lwb != NULL) { 3830 ASSERT(list_is_empty(&zilog->zl_lwb_list)); 3831 ASSERT3S(lwb->lwb_state, ==, LWB_STATE_NEW); 3832 zio_buf_free(lwb->lwb_buf, lwb->lwb_sz); 3833 zil_free_lwb(zilog, lwb); 3834 } 3835 mutex_exit(&zilog->zl_lock); 3836 } 3837 3838 static const char *suspend_tag = "zil suspending"; 3839 3840 /* 3841 * Suspend an intent log. While in suspended mode, we still honor 3842 * synchronous semantics, but we rely on txg_wait_synced() to do it. 3843 * On old version pools, we suspend the log briefly when taking a 3844 * snapshot so that it will have an empty intent log. 3845 * 3846 * Long holds are not really intended to be used the way we do here -- 3847 * held for such a short time. A concurrent caller of dsl_dataset_long_held() 3848 * could fail. Therefore we take pains to only put a long hold if it is 3849 * actually necessary. Fortunately, it will only be necessary if the 3850 * objset is currently mounted (or the ZVOL equivalent). In that case it 3851 * will already have a long hold, so we are not really making things any worse. 3852 * 3853 * Ideally, we would locate the existing long-holder (i.e. the zfsvfs_t or 3854 * zvol_state_t), and use their mechanism to prevent their hold from being 3855 * dropped (e.g. VFS_HOLD()). However, that would be even more pain for 3856 * very little gain. 3857 * 3858 * if cookiep == NULL, this does both the suspend & resume. 3859 * Otherwise, it returns with the dataset "long held", and the cookie 3860 * should be passed into zil_resume(). 3861 */ 3862 int 3863 zil_suspend(const char *osname, void **cookiep) 3864 { 3865 objset_t *os; 3866 zilog_t *zilog; 3867 const zil_header_t *zh; 3868 int error; 3869 3870 error = dmu_objset_hold(osname, suspend_tag, &os); 3871 if (error != 0) 3872 return (error); 3873 zilog = dmu_objset_zil(os); 3874 3875 mutex_enter(&zilog->zl_lock); 3876 zh = zilog->zl_header; 3877 3878 if (zh->zh_flags & ZIL_REPLAY_NEEDED) { /* unplayed log */ 3879 mutex_exit(&zilog->zl_lock); 3880 dmu_objset_rele(os, suspend_tag); 3881 return (SET_ERROR(EBUSY)); 3882 } 3883 3884 /* 3885 * Don't put a long hold in the cases where we can avoid it. This 3886 * is when there is no cookie so we are doing a suspend & resume 3887 * (i.e. called from zil_vdev_offline()), and there's nothing to do 3888 * for the suspend because it's already suspended, or there's no ZIL. 3889 */ 3890 if (cookiep == NULL && !zilog->zl_suspending && 3891 (zilog->zl_suspend > 0 || BP_IS_HOLE(&zh->zh_log))) { 3892 mutex_exit(&zilog->zl_lock); 3893 dmu_objset_rele(os, suspend_tag); 3894 return (0); 3895 } 3896 3897 dsl_dataset_long_hold(dmu_objset_ds(os), suspend_tag); 3898 dsl_pool_rele(dmu_objset_pool(os), suspend_tag); 3899 3900 zilog->zl_suspend++; 3901 3902 if (zilog->zl_suspend > 1) { 3903 /* 3904 * Someone else is already suspending it. 3905 * Just wait for them to finish. 3906 */ 3907 3908 while (zilog->zl_suspending) 3909 cv_wait(&zilog->zl_cv_suspend, &zilog->zl_lock); 3910 mutex_exit(&zilog->zl_lock); 3911 3912 if (cookiep == NULL) 3913 zil_resume(os); 3914 else 3915 *cookiep = os; 3916 return (0); 3917 } 3918 3919 /* 3920 * If there is no pointer to an on-disk block, this ZIL must not 3921 * be active (e.g. filesystem not mounted), so there's nothing 3922 * to clean up. 3923 */ 3924 if (BP_IS_HOLE(&zh->zh_log)) { 3925 ASSERT(cookiep != NULL); /* fast path already handled */ 3926 3927 *cookiep = os; 3928 mutex_exit(&zilog->zl_lock); 3929 return (0); 3930 } 3931 3932 /* 3933 * The ZIL has work to do. Ensure that the associated encryption 3934 * key will remain mapped while we are committing the log by 3935 * grabbing a reference to it. If the key isn't loaded we have no 3936 * choice but to return an error until the wrapping key is loaded. 3937 */ 3938 if (os->os_encrypted && 3939 dsl_dataset_create_key_mapping(dmu_objset_ds(os)) != 0) { 3940 zilog->zl_suspend--; 3941 mutex_exit(&zilog->zl_lock); 3942 dsl_dataset_long_rele(dmu_objset_ds(os), suspend_tag); 3943 dsl_dataset_rele(dmu_objset_ds(os), suspend_tag); 3944 return (SET_ERROR(EACCES)); 3945 } 3946 3947 zilog->zl_suspending = B_TRUE; 3948 mutex_exit(&zilog->zl_lock); 3949 3950 /* 3951 * We need to use zil_commit_impl to ensure we wait for all 3952 * LWB_STATE_OPENED, _CLOSED and _READY lwbs to be committed 3953 * to disk before proceeding. If we used zil_commit instead, it 3954 * would just call txg_wait_synced(), because zl_suspend is set. 3955 * txg_wait_synced() doesn't wait for these lwb's to be 3956 * LWB_STATE_FLUSH_DONE before returning. 3957 */ 3958 zil_commit_impl(zilog, 0); 3959 3960 /* 3961 * Now that we've ensured all lwb's are LWB_STATE_FLUSH_DONE, we 3962 * use txg_wait_synced() to ensure the data from the zilog has 3963 * migrated to the main pool before calling zil_destroy(). 3964 */ 3965 txg_wait_synced(zilog->zl_dmu_pool, 0); 3966 3967 zil_destroy(zilog, B_FALSE); 3968 3969 mutex_enter(&zilog->zl_lock); 3970 zilog->zl_suspending = B_FALSE; 3971 cv_broadcast(&zilog->zl_cv_suspend); 3972 mutex_exit(&zilog->zl_lock); 3973 3974 if (os->os_encrypted) 3975 dsl_dataset_remove_key_mapping(dmu_objset_ds(os)); 3976 3977 if (cookiep == NULL) 3978 zil_resume(os); 3979 else 3980 *cookiep = os; 3981 return (0); 3982 } 3983 3984 void 3985 zil_resume(void *cookie) 3986 { 3987 objset_t *os = cookie; 3988 zilog_t *zilog = dmu_objset_zil(os); 3989 3990 mutex_enter(&zilog->zl_lock); 3991 ASSERT(zilog->zl_suspend != 0); 3992 zilog->zl_suspend--; 3993 mutex_exit(&zilog->zl_lock); 3994 dsl_dataset_long_rele(dmu_objset_ds(os), suspend_tag); 3995 dsl_dataset_rele(dmu_objset_ds(os), suspend_tag); 3996 } 3997 3998 typedef struct zil_replay_arg { 3999 zil_replay_func_t *const *zr_replay; 4000 void *zr_arg; 4001 boolean_t zr_byteswap; 4002 char *zr_lr; 4003 } zil_replay_arg_t; 4004 4005 static int 4006 zil_replay_error(zilog_t *zilog, const lr_t *lr, int error) 4007 { 4008 char name[ZFS_MAX_DATASET_NAME_LEN]; 4009 4010 zilog->zl_replaying_seq--; /* didn't actually replay this one */ 4011 4012 dmu_objset_name(zilog->zl_os, name); 4013 4014 cmn_err(CE_WARN, "ZFS replay transaction error %d, " 4015 "dataset %s, seq 0x%llx, txtype %llu %s\n", error, name, 4016 (u_longlong_t)lr->lrc_seq, 4017 (u_longlong_t)(lr->lrc_txtype & ~TX_CI), 4018 (lr->lrc_txtype & TX_CI) ? "CI" : ""); 4019 4020 return (error); 4021 } 4022 4023 static int 4024 zil_replay_log_record(zilog_t *zilog, const lr_t *lr, void *zra, 4025 uint64_t claim_txg) 4026 { 4027 zil_replay_arg_t *zr = zra; 4028 const zil_header_t *zh = zilog->zl_header; 4029 uint64_t reclen = lr->lrc_reclen; 4030 uint64_t txtype = lr->lrc_txtype; 4031 int error = 0; 4032 4033 zilog->zl_replaying_seq = lr->lrc_seq; 4034 4035 if (lr->lrc_seq <= zh->zh_replay_seq) /* already replayed */ 4036 return (0); 4037 4038 if (lr->lrc_txg < claim_txg) /* already committed */ 4039 return (0); 4040 4041 /* Strip case-insensitive bit, still present in log record */ 4042 txtype &= ~TX_CI; 4043 4044 if (txtype == 0 || txtype >= TX_MAX_TYPE) 4045 return (zil_replay_error(zilog, lr, EINVAL)); 4046 4047 /* 4048 * If this record type can be logged out of order, the object 4049 * (lr_foid) may no longer exist. That's legitimate, not an error. 4050 */ 4051 if (TX_OOO(txtype)) { 4052 error = dmu_object_info(zilog->zl_os, 4053 LR_FOID_GET_OBJ(((lr_ooo_t *)lr)->lr_foid), NULL); 4054 if (error == ENOENT || error == EEXIST) 4055 return (0); 4056 } 4057 4058 /* 4059 * Make a copy of the data so we can revise and extend it. 4060 */ 4061 memcpy(zr->zr_lr, lr, reclen); 4062 4063 /* 4064 * If this is a TX_WRITE with a blkptr, suck in the data. 4065 */ 4066 if (txtype == TX_WRITE && reclen == sizeof (lr_write_t)) { 4067 error = zil_read_log_data(zilog, (lr_write_t *)lr, 4068 zr->zr_lr + reclen); 4069 if (error != 0) 4070 return (zil_replay_error(zilog, lr, error)); 4071 } 4072 4073 /* 4074 * The log block containing this lr may have been byteswapped 4075 * so that we can easily examine common fields like lrc_txtype. 4076 * However, the log is a mix of different record types, and only the 4077 * replay vectors know how to byteswap their records. Therefore, if 4078 * the lr was byteswapped, undo it before invoking the replay vector. 4079 */ 4080 if (zr->zr_byteswap) 4081 byteswap_uint64_array(zr->zr_lr, reclen); 4082 4083 /* 4084 * We must now do two things atomically: replay this log record, 4085 * and update the log header sequence number to reflect the fact that 4086 * we did so. At the end of each replay function the sequence number 4087 * is updated if we are in replay mode. 4088 */ 4089 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, zr->zr_byteswap); 4090 if (error != 0) { 4091 /* 4092 * The DMU's dnode layer doesn't see removes until the txg 4093 * commits, so a subsequent claim can spuriously fail with 4094 * EEXIST. So if we receive any error we try syncing out 4095 * any removes then retry the transaction. Note that we 4096 * specify B_FALSE for byteswap now, so we don't do it twice. 4097 */ 4098 txg_wait_synced(spa_get_dsl(zilog->zl_spa), 0); 4099 error = zr->zr_replay[txtype](zr->zr_arg, zr->zr_lr, B_FALSE); 4100 if (error != 0) 4101 return (zil_replay_error(zilog, lr, error)); 4102 } 4103 return (0); 4104 } 4105 4106 static int 4107 zil_incr_blks(zilog_t *zilog, const blkptr_t *bp, void *arg, uint64_t claim_txg) 4108 { 4109 (void) bp, (void) arg, (void) claim_txg; 4110 4111 zilog->zl_replay_blks++; 4112 4113 return (0); 4114 } 4115 4116 /* 4117 * If this dataset has a non-empty intent log, replay it and destroy it. 4118 * Return B_TRUE if there were any entries to replay. 4119 */ 4120 boolean_t 4121 zil_replay(objset_t *os, void *arg, 4122 zil_replay_func_t *const replay_func[TX_MAX_TYPE]) 4123 { 4124 zilog_t *zilog = dmu_objset_zil(os); 4125 const zil_header_t *zh = zilog->zl_header; 4126 zil_replay_arg_t zr; 4127 4128 if ((zh->zh_flags & ZIL_REPLAY_NEEDED) == 0) { 4129 return (zil_destroy(zilog, B_TRUE)); 4130 } 4131 4132 zr.zr_replay = replay_func; 4133 zr.zr_arg = arg; 4134 zr.zr_byteswap = BP_SHOULD_BYTESWAP(&zh->zh_log); 4135 zr.zr_lr = vmem_alloc(2 * SPA_MAXBLOCKSIZE, KM_SLEEP); 4136 4137 /* 4138 * Wait for in-progress removes to sync before starting replay. 4139 */ 4140 txg_wait_synced(zilog->zl_dmu_pool, 0); 4141 4142 zilog->zl_replay = B_TRUE; 4143 zilog->zl_replay_time = ddi_get_lbolt(); 4144 ASSERT(zilog->zl_replay_blks == 0); 4145 (void) zil_parse(zilog, zil_incr_blks, zil_replay_log_record, &zr, 4146 zh->zh_claim_txg, B_TRUE); 4147 vmem_free(zr.zr_lr, 2 * SPA_MAXBLOCKSIZE); 4148 4149 zil_destroy(zilog, B_FALSE); 4150 txg_wait_synced(zilog->zl_dmu_pool, zilog->zl_destroy_txg); 4151 zilog->zl_replay = B_FALSE; 4152 4153 return (B_TRUE); 4154 } 4155 4156 boolean_t 4157 zil_replaying(zilog_t *zilog, dmu_tx_t *tx) 4158 { 4159 if (zilog->zl_sync == ZFS_SYNC_DISABLED) 4160 return (B_TRUE); 4161 4162 if (zilog->zl_replay) { 4163 dsl_dataset_dirty(dmu_objset_ds(zilog->zl_os), tx); 4164 zilog->zl_replayed_seq[dmu_tx_get_txg(tx) & TXG_MASK] = 4165 zilog->zl_replaying_seq; 4166 return (B_TRUE); 4167 } 4168 4169 return (B_FALSE); 4170 } 4171 4172 int 4173 zil_reset(const char *osname, void *arg) 4174 { 4175 (void) arg; 4176 4177 int error = zil_suspend(osname, NULL); 4178 /* EACCES means crypto key not loaded */ 4179 if ((error == EACCES) || (error == EBUSY)) 4180 return (SET_ERROR(error)); 4181 if (error != 0) 4182 return (SET_ERROR(EEXIST)); 4183 return (0); 4184 } 4185 4186 EXPORT_SYMBOL(zil_alloc); 4187 EXPORT_SYMBOL(zil_free); 4188 EXPORT_SYMBOL(zil_open); 4189 EXPORT_SYMBOL(zil_close); 4190 EXPORT_SYMBOL(zil_replay); 4191 EXPORT_SYMBOL(zil_replaying); 4192 EXPORT_SYMBOL(zil_destroy); 4193 EXPORT_SYMBOL(zil_destroy_sync); 4194 EXPORT_SYMBOL(zil_itx_create); 4195 EXPORT_SYMBOL(zil_itx_destroy); 4196 EXPORT_SYMBOL(zil_itx_assign); 4197 EXPORT_SYMBOL(zil_commit); 4198 EXPORT_SYMBOL(zil_claim); 4199 EXPORT_SYMBOL(zil_check_log_chain); 4200 EXPORT_SYMBOL(zil_sync); 4201 EXPORT_SYMBOL(zil_clean); 4202 EXPORT_SYMBOL(zil_suspend); 4203 EXPORT_SYMBOL(zil_resume); 4204 EXPORT_SYMBOL(zil_lwb_add_block); 4205 EXPORT_SYMBOL(zil_bp_tree_add); 4206 EXPORT_SYMBOL(zil_set_sync); 4207 EXPORT_SYMBOL(zil_set_logbias); 4208 EXPORT_SYMBOL(zil_sums_init); 4209 EXPORT_SYMBOL(zil_sums_fini); 4210 EXPORT_SYMBOL(zil_kstat_values_update); 4211 4212 ZFS_MODULE_PARAM(zfs, zfs_, commit_timeout_pct, UINT, ZMOD_RW, 4213 "ZIL block open timeout percentage"); 4214 4215 ZFS_MODULE_PARAM(zfs_zil, zil_, min_commit_timeout, U64, ZMOD_RW, 4216 "Minimum delay we care for ZIL block commit"); 4217 4218 ZFS_MODULE_PARAM(zfs_zil, zil_, replay_disable, INT, ZMOD_RW, 4219 "Disable intent logging replay"); 4220 4221 ZFS_MODULE_PARAM(zfs_zil, zil_, nocacheflush, INT, ZMOD_RW, 4222 "Disable ZIL cache flushes"); 4223 4224 ZFS_MODULE_PARAM(zfs_zil, zil_, slog_bulk, U64, ZMOD_RW, 4225 "Limit in bytes slog sync writes per commit"); 4226 4227 ZFS_MODULE_PARAM(zfs_zil, zil_, maxblocksize, UINT, ZMOD_RW, 4228 "Limit in bytes of ZIL log block size"); 4229