1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2011 by Delphix. All rights reserved. 24 * Copyright (c) 2011 Nexenta Systems, Inc. All rights reserved. 25 */ 26 27 #include <sys/zfs_context.h> 28 #include <sys/fm/fs/zfs.h> 29 #include <sys/spa.h> 30 #include <sys/txg.h> 31 #include <sys/spa_impl.h> 32 #include <sys/vdev_impl.h> 33 #include <sys/zio_impl.h> 34 #include <sys/zio_compress.h> 35 #include <sys/zio_checksum.h> 36 #include <sys/dmu_objset.h> 37 #include <sys/arc.h> 38 #include <sys/ddt.h> 39 40 /* 41 * ========================================================================== 42 * I/O priority table 43 * ========================================================================== 44 */ 45 uint8_t zio_priority_table[ZIO_PRIORITY_TABLE_SIZE] = { 46 0, /* ZIO_PRIORITY_NOW */ 47 0, /* ZIO_PRIORITY_SYNC_READ */ 48 0, /* ZIO_PRIORITY_SYNC_WRITE */ 49 0, /* ZIO_PRIORITY_LOG_WRITE */ 50 1, /* ZIO_PRIORITY_CACHE_FILL */ 51 1, /* ZIO_PRIORITY_AGG */ 52 4, /* ZIO_PRIORITY_FREE */ 53 4, /* ZIO_PRIORITY_ASYNC_WRITE */ 54 6, /* ZIO_PRIORITY_ASYNC_READ */ 55 10, /* ZIO_PRIORITY_RESILVER */ 56 20, /* ZIO_PRIORITY_SCRUB */ 57 2, /* ZIO_PRIORITY_DDT_PREFETCH */ 58 }; 59 60 /* 61 * ========================================================================== 62 * I/O type descriptions 63 * ========================================================================== 64 */ 65 char *zio_type_name[ZIO_TYPES] = { 66 "zio_null", "zio_read", "zio_write", "zio_free", "zio_claim", 67 "zio_ioctl" 68 }; 69 70 /* 71 * ========================================================================== 72 * I/O kmem caches 73 * ========================================================================== 74 */ 75 kmem_cache_t *zio_cache; 76 kmem_cache_t *zio_link_cache; 77 kmem_cache_t *zio_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; 78 kmem_cache_t *zio_data_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; 79 80 #ifdef _KERNEL 81 extern vmem_t *zio_alloc_arena; 82 #endif 83 extern int zfs_mg_alloc_failures; 84 85 /* 86 * An allocating zio is one that either currently has the DVA allocate 87 * stage set or will have it later in its lifetime. 88 */ 89 #define IO_IS_ALLOCATING(zio) ((zio)->io_orig_pipeline & ZIO_STAGE_DVA_ALLOCATE) 90 91 boolean_t zio_requeue_io_start_cut_in_line = B_TRUE; 92 93 #ifdef ZFS_DEBUG 94 int zio_buf_debug_limit = 16384; 95 #else 96 int zio_buf_debug_limit = 0; 97 #endif 98 99 void 100 zio_init(void) 101 { 102 size_t c; 103 vmem_t *data_alloc_arena = NULL; 104 105 #ifdef _KERNEL 106 data_alloc_arena = zio_alloc_arena; 107 #endif 108 zio_cache = kmem_cache_create("zio_cache", 109 sizeof (zio_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 110 zio_link_cache = kmem_cache_create("zio_link_cache", 111 sizeof (zio_link_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 112 113 /* 114 * For small buffers, we want a cache for each multiple of 115 * SPA_MINBLOCKSIZE. For medium-size buffers, we want a cache 116 * for each quarter-power of 2. For large buffers, we want 117 * a cache for each multiple of PAGESIZE. 118 */ 119 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { 120 size_t size = (c + 1) << SPA_MINBLOCKSHIFT; 121 size_t p2 = size; 122 size_t align = 0; 123 size_t cflags = (size > zio_buf_debug_limit) ? KMC_NODEBUG : 0; 124 125 while (p2 & (p2 - 1)) 126 p2 &= p2 - 1; 127 128 if (size <= 4 * SPA_MINBLOCKSIZE) { 129 align = SPA_MINBLOCKSIZE; 130 } else if (P2PHASE(size, PAGESIZE) == 0) { 131 align = PAGESIZE; 132 } else if (P2PHASE(size, p2 >> 2) == 0) { 133 align = p2 >> 2; 134 } 135 136 if (align != 0) { 137 char name[36]; 138 (void) sprintf(name, "zio_buf_%lu", (ulong_t)size); 139 zio_buf_cache[c] = kmem_cache_create(name, size, 140 align, NULL, NULL, NULL, NULL, NULL, cflags); 141 142 /* 143 * Since zio_data bufs do not appear in crash dumps, we 144 * pass KMC_NOTOUCH so that no allocator metadata is 145 * stored with the buffers. 146 */ 147 (void) sprintf(name, "zio_data_buf_%lu", (ulong_t)size); 148 zio_data_buf_cache[c] = kmem_cache_create(name, size, 149 align, NULL, NULL, NULL, NULL, data_alloc_arena, 150 cflags | KMC_NOTOUCH); 151 } 152 } 153 154 while (--c != 0) { 155 ASSERT(zio_buf_cache[c] != NULL); 156 if (zio_buf_cache[c - 1] == NULL) 157 zio_buf_cache[c - 1] = zio_buf_cache[c]; 158 159 ASSERT(zio_data_buf_cache[c] != NULL); 160 if (zio_data_buf_cache[c - 1] == NULL) 161 zio_data_buf_cache[c - 1] = zio_data_buf_cache[c]; 162 } 163 164 /* 165 * The zio write taskqs have 1 thread per cpu, allow 1/2 of the taskqs 166 * to fail 3 times per txg or 8 failures, whichever is greater. 167 */ 168 zfs_mg_alloc_failures = MAX((3 * max_ncpus / 2), 8); 169 170 zio_inject_init(); 171 } 172 173 void 174 zio_fini(void) 175 { 176 size_t c; 177 kmem_cache_t *last_cache = NULL; 178 kmem_cache_t *last_data_cache = NULL; 179 180 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { 181 if (zio_buf_cache[c] != last_cache) { 182 last_cache = zio_buf_cache[c]; 183 kmem_cache_destroy(zio_buf_cache[c]); 184 } 185 zio_buf_cache[c] = NULL; 186 187 if (zio_data_buf_cache[c] != last_data_cache) { 188 last_data_cache = zio_data_buf_cache[c]; 189 kmem_cache_destroy(zio_data_buf_cache[c]); 190 } 191 zio_data_buf_cache[c] = NULL; 192 } 193 194 kmem_cache_destroy(zio_link_cache); 195 kmem_cache_destroy(zio_cache); 196 197 zio_inject_fini(); 198 } 199 200 /* 201 * ========================================================================== 202 * Allocate and free I/O buffers 203 * ========================================================================== 204 */ 205 206 /* 207 * Use zio_buf_alloc to allocate ZFS metadata. This data will appear in a 208 * crashdump if the kernel panics, so use it judiciously. Obviously, it's 209 * useful to inspect ZFS metadata, but if possible, we should avoid keeping 210 * excess / transient data in-core during a crashdump. 211 */ 212 void * 213 zio_buf_alloc(size_t size) 214 { 215 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 216 217 ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 218 219 return (kmem_cache_alloc(zio_buf_cache[c], KM_PUSHPAGE)); 220 } 221 222 /* 223 * Use zio_data_buf_alloc to allocate data. The data will not appear in a 224 * crashdump if the kernel panics. This exists so that we will limit the amount 225 * of ZFS data that shows up in a kernel crashdump. (Thus reducing the amount 226 * of kernel heap dumped to disk when the kernel panics) 227 */ 228 void * 229 zio_data_buf_alloc(size_t size) 230 { 231 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 232 233 ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 234 235 return (kmem_cache_alloc(zio_data_buf_cache[c], KM_PUSHPAGE)); 236 } 237 238 void 239 zio_buf_free(void *buf, size_t size) 240 { 241 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 242 243 ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 244 245 kmem_cache_free(zio_buf_cache[c], buf); 246 } 247 248 void 249 zio_data_buf_free(void *buf, size_t size) 250 { 251 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 252 253 ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 254 255 kmem_cache_free(zio_data_buf_cache[c], buf); 256 } 257 258 /* 259 * ========================================================================== 260 * Push and pop I/O transform buffers 261 * ========================================================================== 262 */ 263 static void 264 zio_push_transform(zio_t *zio, void *data, uint64_t size, uint64_t bufsize, 265 zio_transform_func_t *transform) 266 { 267 zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP); 268 269 zt->zt_orig_data = zio->io_data; 270 zt->zt_orig_size = zio->io_size; 271 zt->zt_bufsize = bufsize; 272 zt->zt_transform = transform; 273 274 zt->zt_next = zio->io_transform_stack; 275 zio->io_transform_stack = zt; 276 277 zio->io_data = data; 278 zio->io_size = size; 279 } 280 281 static void 282 zio_pop_transforms(zio_t *zio) 283 { 284 zio_transform_t *zt; 285 286 while ((zt = zio->io_transform_stack) != NULL) { 287 if (zt->zt_transform != NULL) 288 zt->zt_transform(zio, 289 zt->zt_orig_data, zt->zt_orig_size); 290 291 if (zt->zt_bufsize != 0) 292 zio_buf_free(zio->io_data, zt->zt_bufsize); 293 294 zio->io_data = zt->zt_orig_data; 295 zio->io_size = zt->zt_orig_size; 296 zio->io_transform_stack = zt->zt_next; 297 298 kmem_free(zt, sizeof (zio_transform_t)); 299 } 300 } 301 302 /* 303 * ========================================================================== 304 * I/O transform callbacks for subblocks and decompression 305 * ========================================================================== 306 */ 307 static void 308 zio_subblock(zio_t *zio, void *data, uint64_t size) 309 { 310 ASSERT(zio->io_size > size); 311 312 if (zio->io_type == ZIO_TYPE_READ) 313 bcopy(zio->io_data, data, size); 314 } 315 316 static void 317 zio_decompress(zio_t *zio, void *data, uint64_t size) 318 { 319 if (zio->io_error == 0 && 320 zio_decompress_data(BP_GET_COMPRESS(zio->io_bp), 321 zio->io_data, data, zio->io_size, size) != 0) 322 zio->io_error = EIO; 323 } 324 325 /* 326 * ========================================================================== 327 * I/O parent/child relationships and pipeline interlocks 328 * ========================================================================== 329 */ 330 /* 331 * NOTE - Callers to zio_walk_parents() and zio_walk_children must 332 * continue calling these functions until they return NULL. 333 * Otherwise, the next caller will pick up the list walk in 334 * some indeterminate state. (Otherwise every caller would 335 * have to pass in a cookie to keep the state represented by 336 * io_walk_link, which gets annoying.) 337 */ 338 zio_t * 339 zio_walk_parents(zio_t *cio) 340 { 341 zio_link_t *zl = cio->io_walk_link; 342 list_t *pl = &cio->io_parent_list; 343 344 zl = (zl == NULL) ? list_head(pl) : list_next(pl, zl); 345 cio->io_walk_link = zl; 346 347 if (zl == NULL) 348 return (NULL); 349 350 ASSERT(zl->zl_child == cio); 351 return (zl->zl_parent); 352 } 353 354 zio_t * 355 zio_walk_children(zio_t *pio) 356 { 357 zio_link_t *zl = pio->io_walk_link; 358 list_t *cl = &pio->io_child_list; 359 360 zl = (zl == NULL) ? list_head(cl) : list_next(cl, zl); 361 pio->io_walk_link = zl; 362 363 if (zl == NULL) 364 return (NULL); 365 366 ASSERT(zl->zl_parent == pio); 367 return (zl->zl_child); 368 } 369 370 zio_t * 371 zio_unique_parent(zio_t *cio) 372 { 373 zio_t *pio = zio_walk_parents(cio); 374 375 VERIFY(zio_walk_parents(cio) == NULL); 376 return (pio); 377 } 378 379 void 380 zio_add_child(zio_t *pio, zio_t *cio) 381 { 382 zio_link_t *zl = kmem_cache_alloc(zio_link_cache, KM_SLEEP); 383 384 /* 385 * Logical I/Os can have logical, gang, or vdev children. 386 * Gang I/Os can have gang or vdev children. 387 * Vdev I/Os can only have vdev children. 388 * The following ASSERT captures all of these constraints. 389 */ 390 ASSERT(cio->io_child_type <= pio->io_child_type); 391 392 zl->zl_parent = pio; 393 zl->zl_child = cio; 394 395 mutex_enter(&cio->io_lock); 396 mutex_enter(&pio->io_lock); 397 398 ASSERT(pio->io_state[ZIO_WAIT_DONE] == 0); 399 400 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 401 pio->io_children[cio->io_child_type][w] += !cio->io_state[w]; 402 403 list_insert_head(&pio->io_child_list, zl); 404 list_insert_head(&cio->io_parent_list, zl); 405 406 pio->io_child_count++; 407 cio->io_parent_count++; 408 409 mutex_exit(&pio->io_lock); 410 mutex_exit(&cio->io_lock); 411 } 412 413 static void 414 zio_remove_child(zio_t *pio, zio_t *cio, zio_link_t *zl) 415 { 416 ASSERT(zl->zl_parent == pio); 417 ASSERT(zl->zl_child == cio); 418 419 mutex_enter(&cio->io_lock); 420 mutex_enter(&pio->io_lock); 421 422 list_remove(&pio->io_child_list, zl); 423 list_remove(&cio->io_parent_list, zl); 424 425 pio->io_child_count--; 426 cio->io_parent_count--; 427 428 mutex_exit(&pio->io_lock); 429 mutex_exit(&cio->io_lock); 430 431 kmem_cache_free(zio_link_cache, zl); 432 } 433 434 static boolean_t 435 zio_wait_for_children(zio_t *zio, enum zio_child child, enum zio_wait_type wait) 436 { 437 uint64_t *countp = &zio->io_children[child][wait]; 438 boolean_t waiting = B_FALSE; 439 440 mutex_enter(&zio->io_lock); 441 ASSERT(zio->io_stall == NULL); 442 if (*countp != 0) { 443 zio->io_stage >>= 1; 444 zio->io_stall = countp; 445 waiting = B_TRUE; 446 } 447 mutex_exit(&zio->io_lock); 448 449 return (waiting); 450 } 451 452 static void 453 zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait) 454 { 455 uint64_t *countp = &pio->io_children[zio->io_child_type][wait]; 456 int *errorp = &pio->io_child_error[zio->io_child_type]; 457 458 mutex_enter(&pio->io_lock); 459 if (zio->io_error && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE)) 460 *errorp = zio_worst_error(*errorp, zio->io_error); 461 pio->io_reexecute |= zio->io_reexecute; 462 ASSERT3U(*countp, >, 0); 463 if (--*countp == 0 && pio->io_stall == countp) { 464 pio->io_stall = NULL; 465 mutex_exit(&pio->io_lock); 466 zio_execute(pio); 467 } else { 468 mutex_exit(&pio->io_lock); 469 } 470 } 471 472 static void 473 zio_inherit_child_errors(zio_t *zio, enum zio_child c) 474 { 475 if (zio->io_child_error[c] != 0 && zio->io_error == 0) 476 zio->io_error = zio->io_child_error[c]; 477 } 478 479 /* 480 * ========================================================================== 481 * Create the various types of I/O (read, write, free, etc) 482 * ========================================================================== 483 */ 484 static zio_t * 485 zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 486 void *data, uint64_t size, zio_done_func_t *done, void *private, 487 zio_type_t type, int priority, enum zio_flag flags, 488 vdev_t *vd, uint64_t offset, const zbookmark_t *zb, 489 enum zio_stage stage, enum zio_stage pipeline) 490 { 491 zio_t *zio; 492 493 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 494 ASSERT(P2PHASE(size, SPA_MINBLOCKSIZE) == 0); 495 ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0); 496 497 ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER)); 498 ASSERT(!bp || !(flags & ZIO_FLAG_CONFIG_WRITER)); 499 ASSERT(vd || stage == ZIO_STAGE_OPEN); 500 501 zio = kmem_cache_alloc(zio_cache, KM_SLEEP); 502 bzero(zio, sizeof (zio_t)); 503 504 mutex_init(&zio->io_lock, NULL, MUTEX_DEFAULT, NULL); 505 cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL); 506 507 list_create(&zio->io_parent_list, sizeof (zio_link_t), 508 offsetof(zio_link_t, zl_parent_node)); 509 list_create(&zio->io_child_list, sizeof (zio_link_t), 510 offsetof(zio_link_t, zl_child_node)); 511 512 if (vd != NULL) 513 zio->io_child_type = ZIO_CHILD_VDEV; 514 else if (flags & ZIO_FLAG_GANG_CHILD) 515 zio->io_child_type = ZIO_CHILD_GANG; 516 else if (flags & ZIO_FLAG_DDT_CHILD) 517 zio->io_child_type = ZIO_CHILD_DDT; 518 else 519 zio->io_child_type = ZIO_CHILD_LOGICAL; 520 521 if (bp != NULL) { 522 zio->io_bp = (blkptr_t *)bp; 523 zio->io_bp_copy = *bp; 524 zio->io_bp_orig = *bp; 525 if (type != ZIO_TYPE_WRITE || 526 zio->io_child_type == ZIO_CHILD_DDT) 527 zio->io_bp = &zio->io_bp_copy; /* so caller can free */ 528 if (zio->io_child_type == ZIO_CHILD_LOGICAL) 529 zio->io_logical = zio; 530 if (zio->io_child_type > ZIO_CHILD_GANG && BP_IS_GANG(bp)) 531 pipeline |= ZIO_GANG_STAGES; 532 } 533 534 zio->io_spa = spa; 535 zio->io_txg = txg; 536 zio->io_done = done; 537 zio->io_private = private; 538 zio->io_type = type; 539 zio->io_priority = priority; 540 zio->io_vd = vd; 541 zio->io_offset = offset; 542 zio->io_orig_data = zio->io_data = data; 543 zio->io_orig_size = zio->io_size = size; 544 zio->io_orig_flags = zio->io_flags = flags; 545 zio->io_orig_stage = zio->io_stage = stage; 546 zio->io_orig_pipeline = zio->io_pipeline = pipeline; 547 548 zio->io_state[ZIO_WAIT_READY] = (stage >= ZIO_STAGE_READY); 549 zio->io_state[ZIO_WAIT_DONE] = (stage >= ZIO_STAGE_DONE); 550 551 if (zb != NULL) 552 zio->io_bookmark = *zb; 553 554 if (pio != NULL) { 555 if (zio->io_logical == NULL) 556 zio->io_logical = pio->io_logical; 557 if (zio->io_child_type == ZIO_CHILD_GANG) 558 zio->io_gang_leader = pio->io_gang_leader; 559 zio_add_child(pio, zio); 560 } 561 562 return (zio); 563 } 564 565 static void 566 zio_destroy(zio_t *zio) 567 { 568 list_destroy(&zio->io_parent_list); 569 list_destroy(&zio->io_child_list); 570 mutex_destroy(&zio->io_lock); 571 cv_destroy(&zio->io_cv); 572 kmem_cache_free(zio_cache, zio); 573 } 574 575 zio_t * 576 zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, zio_done_func_t *done, 577 void *private, enum zio_flag flags) 578 { 579 zio_t *zio; 580 581 zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private, 582 ZIO_TYPE_NULL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL, 583 ZIO_STAGE_OPEN, ZIO_INTERLOCK_PIPELINE); 584 585 return (zio); 586 } 587 588 zio_t * 589 zio_root(spa_t *spa, zio_done_func_t *done, void *private, enum zio_flag flags) 590 { 591 return (zio_null(NULL, spa, NULL, done, private, flags)); 592 } 593 594 zio_t * 595 zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, 596 void *data, uint64_t size, zio_done_func_t *done, void *private, 597 int priority, enum zio_flag flags, const zbookmark_t *zb) 598 { 599 zio_t *zio; 600 601 zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp, 602 data, size, done, private, 603 ZIO_TYPE_READ, priority, flags, NULL, 0, zb, 604 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 605 ZIO_DDT_CHILD_READ_PIPELINE : ZIO_READ_PIPELINE); 606 607 return (zio); 608 } 609 610 zio_t * 611 zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, 612 void *data, uint64_t size, const zio_prop_t *zp, 613 zio_done_func_t *ready, zio_done_func_t *done, void *private, 614 int priority, enum zio_flag flags, const zbookmark_t *zb) 615 { 616 zio_t *zio; 617 618 ASSERT(zp->zp_checksum >= ZIO_CHECKSUM_OFF && 619 zp->zp_checksum < ZIO_CHECKSUM_FUNCTIONS && 620 zp->zp_compress >= ZIO_COMPRESS_OFF && 621 zp->zp_compress < ZIO_COMPRESS_FUNCTIONS && 622 zp->zp_type < DMU_OT_NUMTYPES && 623 zp->zp_level < 32 && 624 zp->zp_copies > 0 && 625 zp->zp_copies <= spa_max_replication(spa) && 626 zp->zp_dedup <= 1 && 627 zp->zp_dedup_verify <= 1); 628 629 zio = zio_create(pio, spa, txg, bp, data, size, done, private, 630 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 631 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 632 ZIO_DDT_CHILD_WRITE_PIPELINE : ZIO_WRITE_PIPELINE); 633 634 zio->io_ready = ready; 635 zio->io_prop = *zp; 636 637 return (zio); 638 } 639 640 zio_t * 641 zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, void *data, 642 uint64_t size, zio_done_func_t *done, void *private, int priority, 643 enum zio_flag flags, zbookmark_t *zb) 644 { 645 zio_t *zio; 646 647 zio = zio_create(pio, spa, txg, bp, data, size, done, private, 648 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 649 ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE); 650 651 return (zio); 652 } 653 654 void 655 zio_write_override(zio_t *zio, blkptr_t *bp, int copies) 656 { 657 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 658 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 659 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 660 ASSERT(zio->io_txg == spa_syncing_txg(zio->io_spa)); 661 662 zio->io_prop.zp_copies = copies; 663 zio->io_bp_override = bp; 664 } 665 666 void 667 zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp) 668 { 669 bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp); 670 } 671 672 zio_t * 673 zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 674 enum zio_flag flags) 675 { 676 zio_t *zio; 677 678 dprintf_bp(bp, "freeing in txg %llu, pass %u", 679 (longlong_t)txg, spa->spa_sync_pass); 680 681 ASSERT(!BP_IS_HOLE(bp)); 682 ASSERT(spa_syncing_txg(spa) == txg); 683 ASSERT(spa_sync_pass(spa) <= SYNC_PASS_DEFERRED_FREE); 684 685 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 686 NULL, NULL, ZIO_TYPE_FREE, ZIO_PRIORITY_FREE, flags, 687 NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_FREE_PIPELINE); 688 689 return (zio); 690 } 691 692 zio_t * 693 zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 694 zio_done_func_t *done, void *private, enum zio_flag flags) 695 { 696 zio_t *zio; 697 698 /* 699 * A claim is an allocation of a specific block. Claims are needed 700 * to support immediate writes in the intent log. The issue is that 701 * immediate writes contain committed data, but in a txg that was 702 * *not* committed. Upon opening the pool after an unclean shutdown, 703 * the intent log claims all blocks that contain immediate write data 704 * so that the SPA knows they're in use. 705 * 706 * All claims *must* be resolved in the first txg -- before the SPA 707 * starts allocating blocks -- so that nothing is allocated twice. 708 * If txg == 0 we just verify that the block is claimable. 709 */ 710 ASSERT3U(spa->spa_uberblock.ub_rootbp.blk_birth, <, spa_first_txg(spa)); 711 ASSERT(txg == spa_first_txg(spa) || txg == 0); 712 ASSERT(!BP_GET_DEDUP(bp) || !spa_writeable(spa)); /* zdb(1M) */ 713 714 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 715 done, private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW, flags, 716 NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE); 717 718 return (zio); 719 } 720 721 zio_t * 722 zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd, 723 zio_done_func_t *done, void *private, int priority, enum zio_flag flags) 724 { 725 zio_t *zio; 726 int c; 727 728 if (vd->vdev_children == 0) { 729 zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private, 730 ZIO_TYPE_IOCTL, priority, flags, vd, 0, NULL, 731 ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE); 732 733 zio->io_cmd = cmd; 734 } else { 735 zio = zio_null(pio, spa, NULL, NULL, NULL, flags); 736 737 for (c = 0; c < vd->vdev_children; c++) 738 zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd, 739 done, private, priority, flags)); 740 } 741 742 return (zio); 743 } 744 745 zio_t * 746 zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 747 void *data, int checksum, zio_done_func_t *done, void *private, 748 int priority, enum zio_flag flags, boolean_t labels) 749 { 750 zio_t *zio; 751 752 ASSERT(vd->vdev_children == 0); 753 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 754 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 755 ASSERT3U(offset + size, <=, vd->vdev_psize); 756 757 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private, 758 ZIO_TYPE_READ, priority, flags, vd, offset, NULL, 759 ZIO_STAGE_OPEN, ZIO_READ_PHYS_PIPELINE); 760 761 zio->io_prop.zp_checksum = checksum; 762 763 return (zio); 764 } 765 766 zio_t * 767 zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 768 void *data, int checksum, zio_done_func_t *done, void *private, 769 int priority, enum zio_flag flags, boolean_t labels) 770 { 771 zio_t *zio; 772 773 ASSERT(vd->vdev_children == 0); 774 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 775 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 776 ASSERT3U(offset + size, <=, vd->vdev_psize); 777 778 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private, 779 ZIO_TYPE_WRITE, priority, flags, vd, offset, NULL, 780 ZIO_STAGE_OPEN, ZIO_WRITE_PHYS_PIPELINE); 781 782 zio->io_prop.zp_checksum = checksum; 783 784 if (zio_checksum_table[checksum].ci_eck) { 785 /* 786 * zec checksums are necessarily destructive -- they modify 787 * the end of the write buffer to hold the verifier/checksum. 788 * Therefore, we must make a local copy in case the data is 789 * being written to multiple places in parallel. 790 */ 791 void *wbuf = zio_buf_alloc(size); 792 bcopy(data, wbuf, size); 793 zio_push_transform(zio, wbuf, size, size, NULL); 794 } 795 796 return (zio); 797 } 798 799 /* 800 * Create a child I/O to do some work for us. 801 */ 802 zio_t * 803 zio_vdev_child_io(zio_t *pio, blkptr_t *bp, vdev_t *vd, uint64_t offset, 804 void *data, uint64_t size, int type, int priority, enum zio_flag flags, 805 zio_done_func_t *done, void *private) 806 { 807 enum zio_stage pipeline = ZIO_VDEV_CHILD_PIPELINE; 808 zio_t *zio; 809 810 ASSERT(vd->vdev_parent == 811 (pio->io_vd ? pio->io_vd : pio->io_spa->spa_root_vdev)); 812 813 if (type == ZIO_TYPE_READ && bp != NULL) { 814 /* 815 * If we have the bp, then the child should perform the 816 * checksum and the parent need not. This pushes error 817 * detection as close to the leaves as possible and 818 * eliminates redundant checksums in the interior nodes. 819 */ 820 pipeline |= ZIO_STAGE_CHECKSUM_VERIFY; 821 pio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 822 } 823 824 if (vd->vdev_children == 0) 825 offset += VDEV_LABEL_START_SIZE; 826 827 flags |= ZIO_VDEV_CHILD_FLAGS(pio) | ZIO_FLAG_DONT_PROPAGATE; 828 829 /* 830 * If we've decided to do a repair, the write is not speculative -- 831 * even if the original read was. 832 */ 833 if (flags & ZIO_FLAG_IO_REPAIR) 834 flags &= ~ZIO_FLAG_SPECULATIVE; 835 836 zio = zio_create(pio, pio->io_spa, pio->io_txg, bp, data, size, 837 done, private, type, priority, flags, vd, offset, &pio->io_bookmark, 838 ZIO_STAGE_VDEV_IO_START >> 1, pipeline); 839 840 return (zio); 841 } 842 843 zio_t * 844 zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, void *data, uint64_t size, 845 int type, int priority, enum zio_flag flags, 846 zio_done_func_t *done, void *private) 847 { 848 zio_t *zio; 849 850 ASSERT(vd->vdev_ops->vdev_op_leaf); 851 852 zio = zio_create(NULL, vd->vdev_spa, 0, NULL, 853 data, size, done, private, type, priority, 854 flags | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY, 855 vd, offset, NULL, 856 ZIO_STAGE_VDEV_IO_START >> 1, ZIO_VDEV_CHILD_PIPELINE); 857 858 return (zio); 859 } 860 861 void 862 zio_flush(zio_t *zio, vdev_t *vd) 863 { 864 zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE, 865 NULL, NULL, ZIO_PRIORITY_NOW, 866 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY)); 867 } 868 869 void 870 zio_shrink(zio_t *zio, uint64_t size) 871 { 872 ASSERT(zio->io_executor == NULL); 873 ASSERT(zio->io_orig_size == zio->io_size); 874 ASSERT(size <= zio->io_size); 875 876 /* 877 * We don't shrink for raidz because of problems with the 878 * reconstruction when reading back less than the block size. 879 * Note, BP_IS_RAIDZ() assumes no compression. 880 */ 881 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 882 if (!BP_IS_RAIDZ(zio->io_bp)) 883 zio->io_orig_size = zio->io_size = size; 884 } 885 886 /* 887 * ========================================================================== 888 * Prepare to read and write logical blocks 889 * ========================================================================== 890 */ 891 892 static int 893 zio_read_bp_init(zio_t *zio) 894 { 895 blkptr_t *bp = zio->io_bp; 896 897 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF && 898 zio->io_child_type == ZIO_CHILD_LOGICAL && 899 !(zio->io_flags & ZIO_FLAG_RAW)) { 900 uint64_t psize = BP_GET_PSIZE(bp); 901 void *cbuf = zio_buf_alloc(psize); 902 903 zio_push_transform(zio, cbuf, psize, psize, zio_decompress); 904 } 905 906 if (!dmu_ot[BP_GET_TYPE(bp)].ot_metadata && BP_GET_LEVEL(bp) == 0) 907 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 908 909 if (BP_GET_TYPE(bp) == DMU_OT_DDT_ZAP) 910 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 911 912 if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL) 913 zio->io_pipeline = ZIO_DDT_READ_PIPELINE; 914 915 return (ZIO_PIPELINE_CONTINUE); 916 } 917 918 static int 919 zio_write_bp_init(zio_t *zio) 920 { 921 spa_t *spa = zio->io_spa; 922 zio_prop_t *zp = &zio->io_prop; 923 enum zio_compress compress = zp->zp_compress; 924 blkptr_t *bp = zio->io_bp; 925 uint64_t lsize = zio->io_size; 926 uint64_t psize = lsize; 927 int pass = 1; 928 929 /* 930 * If our children haven't all reached the ready stage, 931 * wait for them and then repeat this pipeline stage. 932 */ 933 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 934 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_READY)) 935 return (ZIO_PIPELINE_STOP); 936 937 if (!IO_IS_ALLOCATING(zio)) 938 return (ZIO_PIPELINE_CONTINUE); 939 940 ASSERT(zio->io_child_type != ZIO_CHILD_DDT); 941 942 if (zio->io_bp_override) { 943 ASSERT(bp->blk_birth != zio->io_txg); 944 ASSERT(BP_GET_DEDUP(zio->io_bp_override) == 0); 945 946 *bp = *zio->io_bp_override; 947 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 948 949 if (BP_IS_HOLE(bp) || !zp->zp_dedup) 950 return (ZIO_PIPELINE_CONTINUE); 951 952 ASSERT(zio_checksum_table[zp->zp_checksum].ci_dedup || 953 zp->zp_dedup_verify); 954 955 if (BP_GET_CHECKSUM(bp) == zp->zp_checksum) { 956 BP_SET_DEDUP(bp, 1); 957 zio->io_pipeline |= ZIO_STAGE_DDT_WRITE; 958 return (ZIO_PIPELINE_CONTINUE); 959 } 960 zio->io_bp_override = NULL; 961 BP_ZERO(bp); 962 } 963 964 if (bp->blk_birth == zio->io_txg) { 965 /* 966 * We're rewriting an existing block, which means we're 967 * working on behalf of spa_sync(). For spa_sync() to 968 * converge, it must eventually be the case that we don't 969 * have to allocate new blocks. But compression changes 970 * the blocksize, which forces a reallocate, and makes 971 * convergence take longer. Therefore, after the first 972 * few passes, stop compressing to ensure convergence. 973 */ 974 pass = spa_sync_pass(spa); 975 976 ASSERT(zio->io_txg == spa_syncing_txg(spa)); 977 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 978 ASSERT(!BP_GET_DEDUP(bp)); 979 980 if (pass > SYNC_PASS_DONT_COMPRESS) 981 compress = ZIO_COMPRESS_OFF; 982 983 /* Make sure someone doesn't change their mind on overwrites */ 984 ASSERT(MIN(zp->zp_copies + BP_IS_GANG(bp), 985 spa_max_replication(spa)) == BP_GET_NDVAS(bp)); 986 } 987 988 if (compress != ZIO_COMPRESS_OFF) { 989 void *cbuf = zio_buf_alloc(lsize); 990 psize = zio_compress_data(compress, zio->io_data, cbuf, lsize); 991 if (psize == 0 || psize == lsize) { 992 compress = ZIO_COMPRESS_OFF; 993 zio_buf_free(cbuf, lsize); 994 } else { 995 ASSERT(psize < lsize); 996 zio_push_transform(zio, cbuf, psize, lsize, NULL); 997 } 998 } 999 1000 /* 1001 * The final pass of spa_sync() must be all rewrites, but the first 1002 * few passes offer a trade-off: allocating blocks defers convergence, 1003 * but newly allocated blocks are sequential, so they can be written 1004 * to disk faster. Therefore, we allow the first few passes of 1005 * spa_sync() to allocate new blocks, but force rewrites after that. 1006 * There should only be a handful of blocks after pass 1 in any case. 1007 */ 1008 if (bp->blk_birth == zio->io_txg && BP_GET_PSIZE(bp) == psize && 1009 pass > SYNC_PASS_REWRITE) { 1010 ASSERT(psize != 0); 1011 enum zio_stage gang_stages = zio->io_pipeline & ZIO_GANG_STAGES; 1012 zio->io_pipeline = ZIO_REWRITE_PIPELINE | gang_stages; 1013 zio->io_flags |= ZIO_FLAG_IO_REWRITE; 1014 } else { 1015 BP_ZERO(bp); 1016 zio->io_pipeline = ZIO_WRITE_PIPELINE; 1017 } 1018 1019 if (psize == 0) { 1020 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1021 } else { 1022 ASSERT(zp->zp_checksum != ZIO_CHECKSUM_GANG_HEADER); 1023 BP_SET_LSIZE(bp, lsize); 1024 BP_SET_PSIZE(bp, psize); 1025 BP_SET_COMPRESS(bp, compress); 1026 BP_SET_CHECKSUM(bp, zp->zp_checksum); 1027 BP_SET_TYPE(bp, zp->zp_type); 1028 BP_SET_LEVEL(bp, zp->zp_level); 1029 BP_SET_DEDUP(bp, zp->zp_dedup); 1030 BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER); 1031 if (zp->zp_dedup) { 1032 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1033 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1034 zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE; 1035 } 1036 } 1037 1038 return (ZIO_PIPELINE_CONTINUE); 1039 } 1040 1041 static int 1042 zio_free_bp_init(zio_t *zio) 1043 { 1044 blkptr_t *bp = zio->io_bp; 1045 1046 if (zio->io_child_type == ZIO_CHILD_LOGICAL) { 1047 if (BP_GET_DEDUP(bp)) 1048 zio->io_pipeline = ZIO_DDT_FREE_PIPELINE; 1049 } 1050 1051 return (ZIO_PIPELINE_CONTINUE); 1052 } 1053 1054 /* 1055 * ========================================================================== 1056 * Execute the I/O pipeline 1057 * ========================================================================== 1058 */ 1059 1060 static void 1061 zio_taskq_dispatch(zio_t *zio, enum zio_taskq_type q, boolean_t cutinline) 1062 { 1063 spa_t *spa = zio->io_spa; 1064 zio_type_t t = zio->io_type; 1065 int flags = (cutinline ? TQ_FRONT : 0); 1066 1067 /* 1068 * If we're a config writer or a probe, the normal issue and 1069 * interrupt threads may all be blocked waiting for the config lock. 1070 * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL. 1071 */ 1072 if (zio->io_flags & (ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_PROBE)) 1073 t = ZIO_TYPE_NULL; 1074 1075 /* 1076 * A similar issue exists for the L2ARC write thread until L2ARC 2.0. 1077 */ 1078 if (t == ZIO_TYPE_WRITE && zio->io_vd && zio->io_vd->vdev_aux) 1079 t = ZIO_TYPE_NULL; 1080 1081 /* 1082 * If this is a high priority I/O, then use the high priority taskq. 1083 */ 1084 if (zio->io_priority == ZIO_PRIORITY_NOW && 1085 spa->spa_zio_taskq[t][q + 1] != NULL) 1086 q++; 1087 1088 ASSERT3U(q, <, ZIO_TASKQ_TYPES); 1089 1090 /* 1091 * NB: We are assuming that the zio can only be dispatched 1092 * to a single taskq at a time. It would be a grievous error 1093 * to dispatch the zio to another taskq at the same time. 1094 */ 1095 ASSERT(zio->io_tqent.tqent_next == NULL); 1096 taskq_dispatch_ent(spa->spa_zio_taskq[t][q], 1097 (task_func_t *)zio_execute, zio, flags, &zio->io_tqent); 1098 } 1099 1100 static boolean_t 1101 zio_taskq_member(zio_t *zio, enum zio_taskq_type q) 1102 { 1103 kthread_t *executor = zio->io_executor; 1104 spa_t *spa = zio->io_spa; 1105 1106 for (zio_type_t t = 0; t < ZIO_TYPES; t++) 1107 if (taskq_member(spa->spa_zio_taskq[t][q], executor)) 1108 return (B_TRUE); 1109 1110 return (B_FALSE); 1111 } 1112 1113 static int 1114 zio_issue_async(zio_t *zio) 1115 { 1116 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 1117 1118 return (ZIO_PIPELINE_STOP); 1119 } 1120 1121 void 1122 zio_interrupt(zio_t *zio) 1123 { 1124 zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE); 1125 } 1126 1127 /* 1128 * Execute the I/O pipeline until one of the following occurs: 1129 * (1) the I/O completes; (2) the pipeline stalls waiting for 1130 * dependent child I/Os; (3) the I/O issues, so we're waiting 1131 * for an I/O completion interrupt; (4) the I/O is delegated by 1132 * vdev-level caching or aggregation; (5) the I/O is deferred 1133 * due to vdev-level queueing; (6) the I/O is handed off to 1134 * another thread. In all cases, the pipeline stops whenever 1135 * there's no CPU work; it never burns a thread in cv_wait(). 1136 * 1137 * There's no locking on io_stage because there's no legitimate way 1138 * for multiple threads to be attempting to process the same I/O. 1139 */ 1140 static zio_pipe_stage_t *zio_pipeline[]; 1141 1142 void 1143 zio_execute(zio_t *zio) 1144 { 1145 zio->io_executor = curthread; 1146 1147 while (zio->io_stage < ZIO_STAGE_DONE) { 1148 enum zio_stage pipeline = zio->io_pipeline; 1149 enum zio_stage stage = zio->io_stage; 1150 int rv; 1151 1152 ASSERT(!MUTEX_HELD(&zio->io_lock)); 1153 ASSERT(ISP2(stage)); 1154 ASSERT(zio->io_stall == NULL); 1155 1156 do { 1157 stage <<= 1; 1158 } while ((stage & pipeline) == 0); 1159 1160 ASSERT(stage <= ZIO_STAGE_DONE); 1161 1162 /* 1163 * If we are in interrupt context and this pipeline stage 1164 * will grab a config lock that is held across I/O, 1165 * or may wait for an I/O that needs an interrupt thread 1166 * to complete, issue async to avoid deadlock. 1167 * 1168 * For VDEV_IO_START, we cut in line so that the io will 1169 * be sent to disk promptly. 1170 */ 1171 if ((stage & ZIO_BLOCKING_STAGES) && zio->io_vd == NULL && 1172 zio_taskq_member(zio, ZIO_TASKQ_INTERRUPT)) { 1173 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ? 1174 zio_requeue_io_start_cut_in_line : B_FALSE; 1175 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut); 1176 return; 1177 } 1178 1179 zio->io_stage = stage; 1180 rv = zio_pipeline[highbit(stage) - 1](zio); 1181 1182 if (rv == ZIO_PIPELINE_STOP) 1183 return; 1184 1185 ASSERT(rv == ZIO_PIPELINE_CONTINUE); 1186 } 1187 } 1188 1189 /* 1190 * ========================================================================== 1191 * Initiate I/O, either sync or async 1192 * ========================================================================== 1193 */ 1194 int 1195 zio_wait(zio_t *zio) 1196 { 1197 int error; 1198 1199 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 1200 ASSERT(zio->io_executor == NULL); 1201 1202 zio->io_waiter = curthread; 1203 1204 zio_execute(zio); 1205 1206 mutex_enter(&zio->io_lock); 1207 while (zio->io_executor != NULL) 1208 cv_wait(&zio->io_cv, &zio->io_lock); 1209 mutex_exit(&zio->io_lock); 1210 1211 error = zio->io_error; 1212 zio_destroy(zio); 1213 1214 return (error); 1215 } 1216 1217 void 1218 zio_nowait(zio_t *zio) 1219 { 1220 ASSERT(zio->io_executor == NULL); 1221 1222 if (zio->io_child_type == ZIO_CHILD_LOGICAL && 1223 zio_unique_parent(zio) == NULL) { 1224 /* 1225 * This is a logical async I/O with no parent to wait for it. 1226 * We add it to the spa_async_root_zio "Godfather" I/O which 1227 * will ensure they complete prior to unloading the pool. 1228 */ 1229 spa_t *spa = zio->io_spa; 1230 1231 zio_add_child(spa->spa_async_zio_root, zio); 1232 } 1233 1234 zio_execute(zio); 1235 } 1236 1237 /* 1238 * ========================================================================== 1239 * Reexecute or suspend/resume failed I/O 1240 * ========================================================================== 1241 */ 1242 1243 static void 1244 zio_reexecute(zio_t *pio) 1245 { 1246 zio_t *cio, *cio_next; 1247 1248 ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL); 1249 ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN); 1250 ASSERT(pio->io_gang_leader == NULL); 1251 ASSERT(pio->io_gang_tree == NULL); 1252 1253 pio->io_flags = pio->io_orig_flags; 1254 pio->io_stage = pio->io_orig_stage; 1255 pio->io_pipeline = pio->io_orig_pipeline; 1256 pio->io_reexecute = 0; 1257 pio->io_error = 0; 1258 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1259 pio->io_state[w] = 0; 1260 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 1261 pio->io_child_error[c] = 0; 1262 1263 if (IO_IS_ALLOCATING(pio)) 1264 BP_ZERO(pio->io_bp); 1265 1266 /* 1267 * As we reexecute pio's children, new children could be created. 1268 * New children go to the head of pio's io_child_list, however, 1269 * so we will (correctly) not reexecute them. The key is that 1270 * the remainder of pio's io_child_list, from 'cio_next' onward, 1271 * cannot be affected by any side effects of reexecuting 'cio'. 1272 */ 1273 for (cio = zio_walk_children(pio); cio != NULL; cio = cio_next) { 1274 cio_next = zio_walk_children(pio); 1275 mutex_enter(&pio->io_lock); 1276 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1277 pio->io_children[cio->io_child_type][w]++; 1278 mutex_exit(&pio->io_lock); 1279 zio_reexecute(cio); 1280 } 1281 1282 /* 1283 * Now that all children have been reexecuted, execute the parent. 1284 * We don't reexecute "The Godfather" I/O here as it's the 1285 * responsibility of the caller to wait on him. 1286 */ 1287 if (!(pio->io_flags & ZIO_FLAG_GODFATHER)) 1288 zio_execute(pio); 1289 } 1290 1291 void 1292 zio_suspend(spa_t *spa, zio_t *zio) 1293 { 1294 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC) 1295 fm_panic("Pool '%s' has encountered an uncorrectable I/O " 1296 "failure and the failure mode property for this pool " 1297 "is set to panic.", spa_name(spa)); 1298 1299 zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL, NULL, 0, 0); 1300 1301 mutex_enter(&spa->spa_suspend_lock); 1302 1303 if (spa->spa_suspend_zio_root == NULL) 1304 spa->spa_suspend_zio_root = zio_root(spa, NULL, NULL, 1305 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | 1306 ZIO_FLAG_GODFATHER); 1307 1308 spa->spa_suspended = B_TRUE; 1309 1310 if (zio != NULL) { 1311 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 1312 ASSERT(zio != spa->spa_suspend_zio_root); 1313 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1314 ASSERT(zio_unique_parent(zio) == NULL); 1315 ASSERT(zio->io_stage == ZIO_STAGE_DONE); 1316 zio_add_child(spa->spa_suspend_zio_root, zio); 1317 } 1318 1319 mutex_exit(&spa->spa_suspend_lock); 1320 } 1321 1322 int 1323 zio_resume(spa_t *spa) 1324 { 1325 zio_t *pio; 1326 1327 /* 1328 * Reexecute all previously suspended i/o. 1329 */ 1330 mutex_enter(&spa->spa_suspend_lock); 1331 spa->spa_suspended = B_FALSE; 1332 cv_broadcast(&spa->spa_suspend_cv); 1333 pio = spa->spa_suspend_zio_root; 1334 spa->spa_suspend_zio_root = NULL; 1335 mutex_exit(&spa->spa_suspend_lock); 1336 1337 if (pio == NULL) 1338 return (0); 1339 1340 zio_reexecute(pio); 1341 return (zio_wait(pio)); 1342 } 1343 1344 void 1345 zio_resume_wait(spa_t *spa) 1346 { 1347 mutex_enter(&spa->spa_suspend_lock); 1348 while (spa_suspended(spa)) 1349 cv_wait(&spa->spa_suspend_cv, &spa->spa_suspend_lock); 1350 mutex_exit(&spa->spa_suspend_lock); 1351 } 1352 1353 /* 1354 * ========================================================================== 1355 * Gang blocks. 1356 * 1357 * A gang block is a collection of small blocks that looks to the DMU 1358 * like one large block. When zio_dva_allocate() cannot find a block 1359 * of the requested size, due to either severe fragmentation or the pool 1360 * being nearly full, it calls zio_write_gang_block() to construct the 1361 * block from smaller fragments. 1362 * 1363 * A gang block consists of a gang header (zio_gbh_phys_t) and up to 1364 * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like 1365 * an indirect block: it's an array of block pointers. It consumes 1366 * only one sector and hence is allocatable regardless of fragmentation. 1367 * The gang header's bps point to its gang members, which hold the data. 1368 * 1369 * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg> 1370 * as the verifier to ensure uniqueness of the SHA256 checksum. 1371 * Critically, the gang block bp's blk_cksum is the checksum of the data, 1372 * not the gang header. This ensures that data block signatures (needed for 1373 * deduplication) are independent of how the block is physically stored. 1374 * 1375 * Gang blocks can be nested: a gang member may itself be a gang block. 1376 * Thus every gang block is a tree in which root and all interior nodes are 1377 * gang headers, and the leaves are normal blocks that contain user data. 1378 * The root of the gang tree is called the gang leader. 1379 * 1380 * To perform any operation (read, rewrite, free, claim) on a gang block, 1381 * zio_gang_assemble() first assembles the gang tree (minus data leaves) 1382 * in the io_gang_tree field of the original logical i/o by recursively 1383 * reading the gang leader and all gang headers below it. This yields 1384 * an in-core tree containing the contents of every gang header and the 1385 * bps for every constituent of the gang block. 1386 * 1387 * With the gang tree now assembled, zio_gang_issue() just walks the gang tree 1388 * and invokes a callback on each bp. To free a gang block, zio_gang_issue() 1389 * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp. 1390 * zio_claim_gang() provides a similarly trivial wrapper for zio_claim(). 1391 * zio_read_gang() is a wrapper around zio_read() that omits reading gang 1392 * headers, since we already have those in io_gang_tree. zio_rewrite_gang() 1393 * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite() 1394 * of the gang header plus zio_checksum_compute() of the data to update the 1395 * gang header's blk_cksum as described above. 1396 * 1397 * The two-phase assemble/issue model solves the problem of partial failure -- 1398 * what if you'd freed part of a gang block but then couldn't read the 1399 * gang header for another part? Assembling the entire gang tree first 1400 * ensures that all the necessary gang header I/O has succeeded before 1401 * starting the actual work of free, claim, or write. Once the gang tree 1402 * is assembled, free and claim are in-memory operations that cannot fail. 1403 * 1404 * In the event that a gang write fails, zio_dva_unallocate() walks the 1405 * gang tree to immediately free (i.e. insert back into the space map) 1406 * everything we've allocated. This ensures that we don't get ENOSPC 1407 * errors during repeated suspend/resume cycles due to a flaky device. 1408 * 1409 * Gang rewrites only happen during sync-to-convergence. If we can't assemble 1410 * the gang tree, we won't modify the block, so we can safely defer the free 1411 * (knowing that the block is still intact). If we *can* assemble the gang 1412 * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free 1413 * each constituent bp and we can allocate a new block on the next sync pass. 1414 * 1415 * In all cases, the gang tree allows complete recovery from partial failure. 1416 * ========================================================================== 1417 */ 1418 1419 static zio_t * 1420 zio_read_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1421 { 1422 if (gn != NULL) 1423 return (pio); 1424 1425 return (zio_read(pio, pio->io_spa, bp, data, BP_GET_PSIZE(bp), 1426 NULL, NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 1427 &pio->io_bookmark)); 1428 } 1429 1430 zio_t * 1431 zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1432 { 1433 zio_t *zio; 1434 1435 if (gn != NULL) { 1436 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1437 gn->gn_gbh, SPA_GANGBLOCKSIZE, NULL, NULL, pio->io_priority, 1438 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1439 /* 1440 * As we rewrite each gang header, the pipeline will compute 1441 * a new gang block header checksum for it; but no one will 1442 * compute a new data checksum, so we do that here. The one 1443 * exception is the gang leader: the pipeline already computed 1444 * its data checksum because that stage precedes gang assembly. 1445 * (Presently, nothing actually uses interior data checksums; 1446 * this is just good hygiene.) 1447 */ 1448 if (gn != pio->io_gang_leader->io_gang_tree) { 1449 zio_checksum_compute(zio, BP_GET_CHECKSUM(bp), 1450 data, BP_GET_PSIZE(bp)); 1451 } 1452 /* 1453 * If we are here to damage data for testing purposes, 1454 * leave the GBH alone so that we can detect the damage. 1455 */ 1456 if (pio->io_gang_leader->io_flags & ZIO_FLAG_INDUCE_DAMAGE) 1457 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 1458 } else { 1459 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1460 data, BP_GET_PSIZE(bp), NULL, NULL, pio->io_priority, 1461 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1462 } 1463 1464 return (zio); 1465 } 1466 1467 /* ARGSUSED */ 1468 zio_t * 1469 zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1470 { 1471 return (zio_free_sync(pio, pio->io_spa, pio->io_txg, bp, 1472 ZIO_GANG_CHILD_FLAGS(pio))); 1473 } 1474 1475 /* ARGSUSED */ 1476 zio_t * 1477 zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1478 { 1479 return (zio_claim(pio, pio->io_spa, pio->io_txg, bp, 1480 NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio))); 1481 } 1482 1483 static zio_gang_issue_func_t *zio_gang_issue_func[ZIO_TYPES] = { 1484 NULL, 1485 zio_read_gang, 1486 zio_rewrite_gang, 1487 zio_free_gang, 1488 zio_claim_gang, 1489 NULL 1490 }; 1491 1492 static void zio_gang_tree_assemble_done(zio_t *zio); 1493 1494 static zio_gang_node_t * 1495 zio_gang_node_alloc(zio_gang_node_t **gnpp) 1496 { 1497 zio_gang_node_t *gn; 1498 1499 ASSERT(*gnpp == NULL); 1500 1501 gn = kmem_zalloc(sizeof (*gn), KM_SLEEP); 1502 gn->gn_gbh = zio_buf_alloc(SPA_GANGBLOCKSIZE); 1503 *gnpp = gn; 1504 1505 return (gn); 1506 } 1507 1508 static void 1509 zio_gang_node_free(zio_gang_node_t **gnpp) 1510 { 1511 zio_gang_node_t *gn = *gnpp; 1512 1513 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 1514 ASSERT(gn->gn_child[g] == NULL); 1515 1516 zio_buf_free(gn->gn_gbh, SPA_GANGBLOCKSIZE); 1517 kmem_free(gn, sizeof (*gn)); 1518 *gnpp = NULL; 1519 } 1520 1521 static void 1522 zio_gang_tree_free(zio_gang_node_t **gnpp) 1523 { 1524 zio_gang_node_t *gn = *gnpp; 1525 1526 if (gn == NULL) 1527 return; 1528 1529 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 1530 zio_gang_tree_free(&gn->gn_child[g]); 1531 1532 zio_gang_node_free(gnpp); 1533 } 1534 1535 static void 1536 zio_gang_tree_assemble(zio_t *gio, blkptr_t *bp, zio_gang_node_t **gnpp) 1537 { 1538 zio_gang_node_t *gn = zio_gang_node_alloc(gnpp); 1539 1540 ASSERT(gio->io_gang_leader == gio); 1541 ASSERT(BP_IS_GANG(bp)); 1542 1543 zio_nowait(zio_read(gio, gio->io_spa, bp, gn->gn_gbh, 1544 SPA_GANGBLOCKSIZE, zio_gang_tree_assemble_done, gn, 1545 gio->io_priority, ZIO_GANG_CHILD_FLAGS(gio), &gio->io_bookmark)); 1546 } 1547 1548 static void 1549 zio_gang_tree_assemble_done(zio_t *zio) 1550 { 1551 zio_t *gio = zio->io_gang_leader; 1552 zio_gang_node_t *gn = zio->io_private; 1553 blkptr_t *bp = zio->io_bp; 1554 1555 ASSERT(gio == zio_unique_parent(zio)); 1556 ASSERT(zio->io_child_count == 0); 1557 1558 if (zio->io_error) 1559 return; 1560 1561 if (BP_SHOULD_BYTESWAP(bp)) 1562 byteswap_uint64_array(zio->io_data, zio->io_size); 1563 1564 ASSERT(zio->io_data == gn->gn_gbh); 1565 ASSERT(zio->io_size == SPA_GANGBLOCKSIZE); 1566 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 1567 1568 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 1569 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 1570 if (!BP_IS_GANG(gbp)) 1571 continue; 1572 zio_gang_tree_assemble(gio, gbp, &gn->gn_child[g]); 1573 } 1574 } 1575 1576 static void 1577 zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, void *data) 1578 { 1579 zio_t *gio = pio->io_gang_leader; 1580 zio_t *zio; 1581 1582 ASSERT(BP_IS_GANG(bp) == !!gn); 1583 ASSERT(BP_GET_CHECKSUM(bp) == BP_GET_CHECKSUM(gio->io_bp)); 1584 ASSERT(BP_GET_LSIZE(bp) == BP_GET_PSIZE(bp) || gn == gio->io_gang_tree); 1585 1586 /* 1587 * If you're a gang header, your data is in gn->gn_gbh. 1588 * If you're a gang member, your data is in 'data' and gn == NULL. 1589 */ 1590 zio = zio_gang_issue_func[gio->io_type](pio, bp, gn, data); 1591 1592 if (gn != NULL) { 1593 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 1594 1595 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 1596 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 1597 if (BP_IS_HOLE(gbp)) 1598 continue; 1599 zio_gang_tree_issue(zio, gn->gn_child[g], gbp, data); 1600 data = (char *)data + BP_GET_PSIZE(gbp); 1601 } 1602 } 1603 1604 if (gn == gio->io_gang_tree) 1605 ASSERT3P((char *)gio->io_data + gio->io_size, ==, data); 1606 1607 if (zio != pio) 1608 zio_nowait(zio); 1609 } 1610 1611 static int 1612 zio_gang_assemble(zio_t *zio) 1613 { 1614 blkptr_t *bp = zio->io_bp; 1615 1616 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == NULL); 1617 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 1618 1619 zio->io_gang_leader = zio; 1620 1621 zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree); 1622 1623 return (ZIO_PIPELINE_CONTINUE); 1624 } 1625 1626 static int 1627 zio_gang_issue(zio_t *zio) 1628 { 1629 blkptr_t *bp = zio->io_bp; 1630 1631 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE)) 1632 return (ZIO_PIPELINE_STOP); 1633 1634 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio); 1635 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 1636 1637 if (zio->io_child_error[ZIO_CHILD_GANG] == 0) 1638 zio_gang_tree_issue(zio, zio->io_gang_tree, bp, zio->io_data); 1639 else 1640 zio_gang_tree_free(&zio->io_gang_tree); 1641 1642 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1643 1644 return (ZIO_PIPELINE_CONTINUE); 1645 } 1646 1647 static void 1648 zio_write_gang_member_ready(zio_t *zio) 1649 { 1650 zio_t *pio = zio_unique_parent(zio); 1651 zio_t *gio = zio->io_gang_leader; 1652 dva_t *cdva = zio->io_bp->blk_dva; 1653 dva_t *pdva = pio->io_bp->blk_dva; 1654 uint64_t asize; 1655 1656 if (BP_IS_HOLE(zio->io_bp)) 1657 return; 1658 1659 ASSERT(BP_IS_HOLE(&zio->io_bp_orig)); 1660 1661 ASSERT(zio->io_child_type == ZIO_CHILD_GANG); 1662 ASSERT3U(zio->io_prop.zp_copies, ==, gio->io_prop.zp_copies); 1663 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp)); 1664 ASSERT3U(pio->io_prop.zp_copies, <=, BP_GET_NDVAS(pio->io_bp)); 1665 ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp)); 1666 1667 mutex_enter(&pio->io_lock); 1668 for (int d = 0; d < BP_GET_NDVAS(zio->io_bp); d++) { 1669 ASSERT(DVA_GET_GANG(&pdva[d])); 1670 asize = DVA_GET_ASIZE(&pdva[d]); 1671 asize += DVA_GET_ASIZE(&cdva[d]); 1672 DVA_SET_ASIZE(&pdva[d], asize); 1673 } 1674 mutex_exit(&pio->io_lock); 1675 } 1676 1677 static int 1678 zio_write_gang_block(zio_t *pio) 1679 { 1680 spa_t *spa = pio->io_spa; 1681 blkptr_t *bp = pio->io_bp; 1682 zio_t *gio = pio->io_gang_leader; 1683 zio_t *zio; 1684 zio_gang_node_t *gn, **gnpp; 1685 zio_gbh_phys_t *gbh; 1686 uint64_t txg = pio->io_txg; 1687 uint64_t resid = pio->io_size; 1688 uint64_t lsize; 1689 int copies = gio->io_prop.zp_copies; 1690 int gbh_copies = MIN(copies + 1, spa_max_replication(spa)); 1691 zio_prop_t zp; 1692 int error; 1693 1694 error = metaslab_alloc(spa, spa_normal_class(spa), SPA_GANGBLOCKSIZE, 1695 bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp, 1696 METASLAB_HINTBP_FAVOR | METASLAB_GANG_HEADER); 1697 if (error) { 1698 pio->io_error = error; 1699 return (ZIO_PIPELINE_CONTINUE); 1700 } 1701 1702 if (pio == gio) { 1703 gnpp = &gio->io_gang_tree; 1704 } else { 1705 gnpp = pio->io_private; 1706 ASSERT(pio->io_ready == zio_write_gang_member_ready); 1707 } 1708 1709 gn = zio_gang_node_alloc(gnpp); 1710 gbh = gn->gn_gbh; 1711 bzero(gbh, SPA_GANGBLOCKSIZE); 1712 1713 /* 1714 * Create the gang header. 1715 */ 1716 zio = zio_rewrite(pio, spa, txg, bp, gbh, SPA_GANGBLOCKSIZE, NULL, NULL, 1717 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1718 1719 /* 1720 * Create and nowait the gang children. 1721 */ 1722 for (int g = 0; resid != 0; resid -= lsize, g++) { 1723 lsize = P2ROUNDUP(resid / (SPA_GBH_NBLKPTRS - g), 1724 SPA_MINBLOCKSIZE); 1725 ASSERT(lsize >= SPA_MINBLOCKSIZE && lsize <= resid); 1726 1727 zp.zp_checksum = gio->io_prop.zp_checksum; 1728 zp.zp_compress = ZIO_COMPRESS_OFF; 1729 zp.zp_type = DMU_OT_NONE; 1730 zp.zp_level = 0; 1731 zp.zp_copies = gio->io_prop.zp_copies; 1732 zp.zp_dedup = 0; 1733 zp.zp_dedup_verify = 0; 1734 1735 zio_nowait(zio_write(zio, spa, txg, &gbh->zg_blkptr[g], 1736 (char *)pio->io_data + (pio->io_size - resid), lsize, &zp, 1737 zio_write_gang_member_ready, NULL, &gn->gn_child[g], 1738 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 1739 &pio->io_bookmark)); 1740 } 1741 1742 /* 1743 * Set pio's pipeline to just wait for zio to finish. 1744 */ 1745 pio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1746 1747 zio_nowait(zio); 1748 1749 return (ZIO_PIPELINE_CONTINUE); 1750 } 1751 1752 /* 1753 * ========================================================================== 1754 * Dedup 1755 * ========================================================================== 1756 */ 1757 static void 1758 zio_ddt_child_read_done(zio_t *zio) 1759 { 1760 blkptr_t *bp = zio->io_bp; 1761 ddt_entry_t *dde = zio->io_private; 1762 ddt_phys_t *ddp; 1763 zio_t *pio = zio_unique_parent(zio); 1764 1765 mutex_enter(&pio->io_lock); 1766 ddp = ddt_phys_select(dde, bp); 1767 if (zio->io_error == 0) 1768 ddt_phys_clear(ddp); /* this ddp doesn't need repair */ 1769 if (zio->io_error == 0 && dde->dde_repair_data == NULL) 1770 dde->dde_repair_data = zio->io_data; 1771 else 1772 zio_buf_free(zio->io_data, zio->io_size); 1773 mutex_exit(&pio->io_lock); 1774 } 1775 1776 static int 1777 zio_ddt_read_start(zio_t *zio) 1778 { 1779 blkptr_t *bp = zio->io_bp; 1780 1781 ASSERT(BP_GET_DEDUP(bp)); 1782 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 1783 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1784 1785 if (zio->io_child_error[ZIO_CHILD_DDT]) { 1786 ddt_t *ddt = ddt_select(zio->io_spa, bp); 1787 ddt_entry_t *dde = ddt_repair_start(ddt, bp); 1788 ddt_phys_t *ddp = dde->dde_phys; 1789 ddt_phys_t *ddp_self = ddt_phys_select(dde, bp); 1790 blkptr_t blk; 1791 1792 ASSERT(zio->io_vsd == NULL); 1793 zio->io_vsd = dde; 1794 1795 if (ddp_self == NULL) 1796 return (ZIO_PIPELINE_CONTINUE); 1797 1798 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { 1799 if (ddp->ddp_phys_birth == 0 || ddp == ddp_self) 1800 continue; 1801 ddt_bp_create(ddt->ddt_checksum, &dde->dde_key, ddp, 1802 &blk); 1803 zio_nowait(zio_read(zio, zio->io_spa, &blk, 1804 zio_buf_alloc(zio->io_size), zio->io_size, 1805 zio_ddt_child_read_done, dde, zio->io_priority, 1806 ZIO_DDT_CHILD_FLAGS(zio) | ZIO_FLAG_DONT_PROPAGATE, 1807 &zio->io_bookmark)); 1808 } 1809 return (ZIO_PIPELINE_CONTINUE); 1810 } 1811 1812 zio_nowait(zio_read(zio, zio->io_spa, bp, 1813 zio->io_data, zio->io_size, NULL, NULL, zio->io_priority, 1814 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark)); 1815 1816 return (ZIO_PIPELINE_CONTINUE); 1817 } 1818 1819 static int 1820 zio_ddt_read_done(zio_t *zio) 1821 { 1822 blkptr_t *bp = zio->io_bp; 1823 1824 if (zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE)) 1825 return (ZIO_PIPELINE_STOP); 1826 1827 ASSERT(BP_GET_DEDUP(bp)); 1828 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 1829 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1830 1831 if (zio->io_child_error[ZIO_CHILD_DDT]) { 1832 ddt_t *ddt = ddt_select(zio->io_spa, bp); 1833 ddt_entry_t *dde = zio->io_vsd; 1834 if (ddt == NULL) { 1835 ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE); 1836 return (ZIO_PIPELINE_CONTINUE); 1837 } 1838 if (dde == NULL) { 1839 zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1; 1840 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 1841 return (ZIO_PIPELINE_STOP); 1842 } 1843 if (dde->dde_repair_data != NULL) { 1844 bcopy(dde->dde_repair_data, zio->io_data, zio->io_size); 1845 zio->io_child_error[ZIO_CHILD_DDT] = 0; 1846 } 1847 ddt_repair_done(ddt, dde); 1848 zio->io_vsd = NULL; 1849 } 1850 1851 ASSERT(zio->io_vsd == NULL); 1852 1853 return (ZIO_PIPELINE_CONTINUE); 1854 } 1855 1856 static boolean_t 1857 zio_ddt_collision(zio_t *zio, ddt_t *ddt, ddt_entry_t *dde) 1858 { 1859 spa_t *spa = zio->io_spa; 1860 1861 /* 1862 * Note: we compare the original data, not the transformed data, 1863 * because when zio->io_bp is an override bp, we will not have 1864 * pushed the I/O transforms. That's an important optimization 1865 * because otherwise we'd compress/encrypt all dmu_sync() data twice. 1866 */ 1867 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 1868 zio_t *lio = dde->dde_lead_zio[p]; 1869 1870 if (lio != NULL) { 1871 return (lio->io_orig_size != zio->io_orig_size || 1872 bcmp(zio->io_orig_data, lio->io_orig_data, 1873 zio->io_orig_size) != 0); 1874 } 1875 } 1876 1877 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 1878 ddt_phys_t *ddp = &dde->dde_phys[p]; 1879 1880 if (ddp->ddp_phys_birth != 0) { 1881 arc_buf_t *abuf = NULL; 1882 uint32_t aflags = ARC_WAIT; 1883 blkptr_t blk = *zio->io_bp; 1884 int error; 1885 1886 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth); 1887 1888 ddt_exit(ddt); 1889 1890 error = arc_read_nolock(NULL, spa, &blk, 1891 arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ, 1892 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, 1893 &aflags, &zio->io_bookmark); 1894 1895 if (error == 0) { 1896 if (arc_buf_size(abuf) != zio->io_orig_size || 1897 bcmp(abuf->b_data, zio->io_orig_data, 1898 zio->io_orig_size) != 0) 1899 error = EEXIST; 1900 VERIFY(arc_buf_remove_ref(abuf, &abuf) == 1); 1901 } 1902 1903 ddt_enter(ddt); 1904 return (error != 0); 1905 } 1906 } 1907 1908 return (B_FALSE); 1909 } 1910 1911 static void 1912 zio_ddt_child_write_ready(zio_t *zio) 1913 { 1914 int p = zio->io_prop.zp_copies; 1915 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 1916 ddt_entry_t *dde = zio->io_private; 1917 ddt_phys_t *ddp = &dde->dde_phys[p]; 1918 zio_t *pio; 1919 1920 if (zio->io_error) 1921 return; 1922 1923 ddt_enter(ddt); 1924 1925 ASSERT(dde->dde_lead_zio[p] == zio); 1926 1927 ddt_phys_fill(ddp, zio->io_bp); 1928 1929 while ((pio = zio_walk_parents(zio)) != NULL) 1930 ddt_bp_fill(ddp, pio->io_bp, zio->io_txg); 1931 1932 ddt_exit(ddt); 1933 } 1934 1935 static void 1936 zio_ddt_child_write_done(zio_t *zio) 1937 { 1938 int p = zio->io_prop.zp_copies; 1939 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 1940 ddt_entry_t *dde = zio->io_private; 1941 ddt_phys_t *ddp = &dde->dde_phys[p]; 1942 1943 ddt_enter(ddt); 1944 1945 ASSERT(ddp->ddp_refcnt == 0); 1946 ASSERT(dde->dde_lead_zio[p] == zio); 1947 dde->dde_lead_zio[p] = NULL; 1948 1949 if (zio->io_error == 0) { 1950 while (zio_walk_parents(zio) != NULL) 1951 ddt_phys_addref(ddp); 1952 } else { 1953 ddt_phys_clear(ddp); 1954 } 1955 1956 ddt_exit(ddt); 1957 } 1958 1959 static void 1960 zio_ddt_ditto_write_done(zio_t *zio) 1961 { 1962 int p = DDT_PHYS_DITTO; 1963 zio_prop_t *zp = &zio->io_prop; 1964 blkptr_t *bp = zio->io_bp; 1965 ddt_t *ddt = ddt_select(zio->io_spa, bp); 1966 ddt_entry_t *dde = zio->io_private; 1967 ddt_phys_t *ddp = &dde->dde_phys[p]; 1968 ddt_key_t *ddk = &dde->dde_key; 1969 1970 ddt_enter(ddt); 1971 1972 ASSERT(ddp->ddp_refcnt == 0); 1973 ASSERT(dde->dde_lead_zio[p] == zio); 1974 dde->dde_lead_zio[p] = NULL; 1975 1976 if (zio->io_error == 0) { 1977 ASSERT(ZIO_CHECKSUM_EQUAL(bp->blk_cksum, ddk->ddk_cksum)); 1978 ASSERT(zp->zp_copies < SPA_DVAS_PER_BP); 1979 ASSERT(zp->zp_copies == BP_GET_NDVAS(bp) - BP_IS_GANG(bp)); 1980 if (ddp->ddp_phys_birth != 0) 1981 ddt_phys_free(ddt, ddk, ddp, zio->io_txg); 1982 ddt_phys_fill(ddp, bp); 1983 } 1984 1985 ddt_exit(ddt); 1986 } 1987 1988 static int 1989 zio_ddt_write(zio_t *zio) 1990 { 1991 spa_t *spa = zio->io_spa; 1992 blkptr_t *bp = zio->io_bp; 1993 uint64_t txg = zio->io_txg; 1994 zio_prop_t *zp = &zio->io_prop; 1995 int p = zp->zp_copies; 1996 int ditto_copies; 1997 zio_t *cio = NULL; 1998 zio_t *dio = NULL; 1999 ddt_t *ddt = ddt_select(spa, bp); 2000 ddt_entry_t *dde; 2001 ddt_phys_t *ddp; 2002 2003 ASSERT(BP_GET_DEDUP(bp)); 2004 ASSERT(BP_GET_CHECKSUM(bp) == zp->zp_checksum); 2005 ASSERT(BP_IS_HOLE(bp) || zio->io_bp_override); 2006 2007 ddt_enter(ddt); 2008 dde = ddt_lookup(ddt, bp, B_TRUE); 2009 ddp = &dde->dde_phys[p]; 2010 2011 if (zp->zp_dedup_verify && zio_ddt_collision(zio, ddt, dde)) { 2012 /* 2013 * If we're using a weak checksum, upgrade to a strong checksum 2014 * and try again. If we're already using a strong checksum, 2015 * we can't resolve it, so just convert to an ordinary write. 2016 * (And automatically e-mail a paper to Nature?) 2017 */ 2018 if (!zio_checksum_table[zp->zp_checksum].ci_dedup) { 2019 zp->zp_checksum = spa_dedup_checksum(spa); 2020 zio_pop_transforms(zio); 2021 zio->io_stage = ZIO_STAGE_OPEN; 2022 BP_ZERO(bp); 2023 } else { 2024 zp->zp_dedup = 0; 2025 } 2026 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2027 ddt_exit(ddt); 2028 return (ZIO_PIPELINE_CONTINUE); 2029 } 2030 2031 ditto_copies = ddt_ditto_copies_needed(ddt, dde, ddp); 2032 ASSERT(ditto_copies < SPA_DVAS_PER_BP); 2033 2034 if (ditto_copies > ddt_ditto_copies_present(dde) && 2035 dde->dde_lead_zio[DDT_PHYS_DITTO] == NULL) { 2036 zio_prop_t czp = *zp; 2037 2038 czp.zp_copies = ditto_copies; 2039 2040 /* 2041 * If we arrived here with an override bp, we won't have run 2042 * the transform stack, so we won't have the data we need to 2043 * generate a child i/o. So, toss the override bp and restart. 2044 * This is safe, because using the override bp is just an 2045 * optimization; and it's rare, so the cost doesn't matter. 2046 */ 2047 if (zio->io_bp_override) { 2048 zio_pop_transforms(zio); 2049 zio->io_stage = ZIO_STAGE_OPEN; 2050 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2051 zio->io_bp_override = NULL; 2052 BP_ZERO(bp); 2053 ddt_exit(ddt); 2054 return (ZIO_PIPELINE_CONTINUE); 2055 } 2056 2057 dio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2058 zio->io_orig_size, &czp, NULL, 2059 zio_ddt_ditto_write_done, dde, zio->io_priority, 2060 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2061 2062 zio_push_transform(dio, zio->io_data, zio->io_size, 0, NULL); 2063 dde->dde_lead_zio[DDT_PHYS_DITTO] = dio; 2064 } 2065 2066 if (ddp->ddp_phys_birth != 0 || dde->dde_lead_zio[p] != NULL) { 2067 if (ddp->ddp_phys_birth != 0) 2068 ddt_bp_fill(ddp, bp, txg); 2069 if (dde->dde_lead_zio[p] != NULL) 2070 zio_add_child(zio, dde->dde_lead_zio[p]); 2071 else 2072 ddt_phys_addref(ddp); 2073 } else if (zio->io_bp_override) { 2074 ASSERT(bp->blk_birth == txg); 2075 ASSERT(BP_EQUAL(bp, zio->io_bp_override)); 2076 ddt_phys_fill(ddp, bp); 2077 ddt_phys_addref(ddp); 2078 } else { 2079 cio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2080 zio->io_orig_size, zp, zio_ddt_child_write_ready, 2081 zio_ddt_child_write_done, dde, zio->io_priority, 2082 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2083 2084 zio_push_transform(cio, zio->io_data, zio->io_size, 0, NULL); 2085 dde->dde_lead_zio[p] = cio; 2086 } 2087 2088 ddt_exit(ddt); 2089 2090 if (cio) 2091 zio_nowait(cio); 2092 if (dio) 2093 zio_nowait(dio); 2094 2095 return (ZIO_PIPELINE_CONTINUE); 2096 } 2097 2098 ddt_entry_t *freedde; /* for debugging */ 2099 2100 static int 2101 zio_ddt_free(zio_t *zio) 2102 { 2103 spa_t *spa = zio->io_spa; 2104 blkptr_t *bp = zio->io_bp; 2105 ddt_t *ddt = ddt_select(spa, bp); 2106 ddt_entry_t *dde; 2107 ddt_phys_t *ddp; 2108 2109 ASSERT(BP_GET_DEDUP(bp)); 2110 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2111 2112 ddt_enter(ddt); 2113 freedde = dde = ddt_lookup(ddt, bp, B_TRUE); 2114 ddp = ddt_phys_select(dde, bp); 2115 ddt_phys_decref(ddp); 2116 ddt_exit(ddt); 2117 2118 return (ZIO_PIPELINE_CONTINUE); 2119 } 2120 2121 /* 2122 * ========================================================================== 2123 * Allocate and free blocks 2124 * ========================================================================== 2125 */ 2126 static int 2127 zio_dva_allocate(zio_t *zio) 2128 { 2129 spa_t *spa = zio->io_spa; 2130 metaslab_class_t *mc = spa_normal_class(spa); 2131 blkptr_t *bp = zio->io_bp; 2132 int error; 2133 int flags = 0; 2134 2135 if (zio->io_gang_leader == NULL) { 2136 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2137 zio->io_gang_leader = zio; 2138 } 2139 2140 ASSERT(BP_IS_HOLE(bp)); 2141 ASSERT3U(BP_GET_NDVAS(bp), ==, 0); 2142 ASSERT3U(zio->io_prop.zp_copies, >, 0); 2143 ASSERT3U(zio->io_prop.zp_copies, <=, spa_max_replication(spa)); 2144 ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp)); 2145 2146 /* 2147 * The dump device does not support gang blocks so allocation on 2148 * behalf of the dump device (i.e. ZIO_FLAG_NODATA) must avoid 2149 * the "fast" gang feature. 2150 */ 2151 flags |= (zio->io_flags & ZIO_FLAG_NODATA) ? METASLAB_GANG_AVOID : 0; 2152 flags |= (zio->io_flags & ZIO_FLAG_GANG_CHILD) ? 2153 METASLAB_GANG_CHILD : 0; 2154 error = metaslab_alloc(spa, mc, zio->io_size, bp, 2155 zio->io_prop.zp_copies, zio->io_txg, NULL, flags); 2156 2157 if (error) { 2158 spa_dbgmsg(spa, "%s: metaslab allocation failure: zio %p, " 2159 "size %llu, error %d", spa_name(spa), zio, zio->io_size, 2160 error); 2161 if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE) 2162 return (zio_write_gang_block(zio)); 2163 zio->io_error = error; 2164 } 2165 2166 return (ZIO_PIPELINE_CONTINUE); 2167 } 2168 2169 static int 2170 zio_dva_free(zio_t *zio) 2171 { 2172 metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE); 2173 2174 return (ZIO_PIPELINE_CONTINUE); 2175 } 2176 2177 static int 2178 zio_dva_claim(zio_t *zio) 2179 { 2180 int error; 2181 2182 error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg); 2183 if (error) 2184 zio->io_error = error; 2185 2186 return (ZIO_PIPELINE_CONTINUE); 2187 } 2188 2189 /* 2190 * Undo an allocation. This is used by zio_done() when an I/O fails 2191 * and we want to give back the block we just allocated. 2192 * This handles both normal blocks and gang blocks. 2193 */ 2194 static void 2195 zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp) 2196 { 2197 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp)); 2198 ASSERT(zio->io_bp_override == NULL); 2199 2200 if (!BP_IS_HOLE(bp)) 2201 metaslab_free(zio->io_spa, bp, bp->blk_birth, B_TRUE); 2202 2203 if (gn != NULL) { 2204 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 2205 zio_dva_unallocate(zio, gn->gn_child[g], 2206 &gn->gn_gbh->zg_blkptr[g]); 2207 } 2208 } 2209 } 2210 2211 /* 2212 * Try to allocate an intent log block. Return 0 on success, errno on failure. 2213 */ 2214 int 2215 zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp, blkptr_t *old_bp, 2216 uint64_t size, boolean_t use_slog) 2217 { 2218 int error = 1; 2219 2220 ASSERT(txg > spa_syncing_txg(spa)); 2221 2222 if (use_slog) 2223 error = metaslab_alloc(spa, spa_log_class(spa), size, 2224 new_bp, 1, txg, old_bp, METASLAB_HINTBP_AVOID); 2225 2226 if (error) 2227 error = metaslab_alloc(spa, spa_normal_class(spa), size, 2228 new_bp, 1, txg, old_bp, METASLAB_HINTBP_AVOID); 2229 2230 if (error == 0) { 2231 BP_SET_LSIZE(new_bp, size); 2232 BP_SET_PSIZE(new_bp, size); 2233 BP_SET_COMPRESS(new_bp, ZIO_COMPRESS_OFF); 2234 BP_SET_CHECKSUM(new_bp, 2235 spa_version(spa) >= SPA_VERSION_SLIM_ZIL 2236 ? ZIO_CHECKSUM_ZILOG2 : ZIO_CHECKSUM_ZILOG); 2237 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG); 2238 BP_SET_LEVEL(new_bp, 0); 2239 BP_SET_DEDUP(new_bp, 0); 2240 BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER); 2241 } 2242 2243 return (error); 2244 } 2245 2246 /* 2247 * Free an intent log block. 2248 */ 2249 void 2250 zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp) 2251 { 2252 ASSERT(BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG); 2253 ASSERT(!BP_IS_GANG(bp)); 2254 2255 zio_free(spa, txg, bp); 2256 } 2257 2258 /* 2259 * ========================================================================== 2260 * Read and write to physical devices 2261 * ========================================================================== 2262 */ 2263 static int 2264 zio_vdev_io_start(zio_t *zio) 2265 { 2266 vdev_t *vd = zio->io_vd; 2267 uint64_t align; 2268 spa_t *spa = zio->io_spa; 2269 2270 ASSERT(zio->io_error == 0); 2271 ASSERT(zio->io_child_error[ZIO_CHILD_VDEV] == 0); 2272 2273 if (vd == NULL) { 2274 if (!(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 2275 spa_config_enter(spa, SCL_ZIO, zio, RW_READER); 2276 2277 /* 2278 * The mirror_ops handle multiple DVAs in a single BP. 2279 */ 2280 return (vdev_mirror_ops.vdev_op_io_start(zio)); 2281 } 2282 2283 /* 2284 * We keep track of time-sensitive I/Os so that the scan thread 2285 * can quickly react to certain workloads. In particular, we care 2286 * about non-scrubbing, top-level reads and writes with the following 2287 * characteristics: 2288 * - synchronous writes of user data to non-slog devices 2289 * - any reads of user data 2290 * When these conditions are met, adjust the timestamp of spa_last_io 2291 * which allows the scan thread to adjust its workload accordingly. 2292 */ 2293 if (!(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && zio->io_bp != NULL && 2294 vd == vd->vdev_top && !vd->vdev_islog && 2295 zio->io_bookmark.zb_objset != DMU_META_OBJSET && 2296 zio->io_txg != spa_syncing_txg(spa)) { 2297 uint64_t old = spa->spa_last_io; 2298 uint64_t new = ddi_get_lbolt64(); 2299 if (old != new) 2300 (void) atomic_cas_64(&spa->spa_last_io, old, new); 2301 } 2302 2303 align = 1ULL << vd->vdev_top->vdev_ashift; 2304 2305 if (P2PHASE(zio->io_size, align) != 0) { 2306 uint64_t asize = P2ROUNDUP(zio->io_size, align); 2307 char *abuf = zio_buf_alloc(asize); 2308 ASSERT(vd == vd->vdev_top); 2309 if (zio->io_type == ZIO_TYPE_WRITE) { 2310 bcopy(zio->io_data, abuf, zio->io_size); 2311 bzero(abuf + zio->io_size, asize - zio->io_size); 2312 } 2313 zio_push_transform(zio, abuf, asize, asize, zio_subblock); 2314 } 2315 2316 ASSERT(P2PHASE(zio->io_offset, align) == 0); 2317 ASSERT(P2PHASE(zio->io_size, align) == 0); 2318 VERIFY(zio->io_type != ZIO_TYPE_WRITE || spa_writeable(spa)); 2319 2320 /* 2321 * If this is a repair I/O, and there's no self-healing involved -- 2322 * that is, we're just resilvering what we expect to resilver -- 2323 * then don't do the I/O unless zio's txg is actually in vd's DTL. 2324 * This prevents spurious resilvering with nested replication. 2325 * For example, given a mirror of mirrors, (A+B)+(C+D), if only 2326 * A is out of date, we'll read from C+D, then use the data to 2327 * resilver A+B -- but we don't actually want to resilver B, just A. 2328 * The top-level mirror has no way to know this, so instead we just 2329 * discard unnecessary repairs as we work our way down the vdev tree. 2330 * The same logic applies to any form of nested replication: 2331 * ditto + mirror, RAID-Z + replacing, etc. This covers them all. 2332 */ 2333 if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) && 2334 !(zio->io_flags & ZIO_FLAG_SELF_HEAL) && 2335 zio->io_txg != 0 && /* not a delegated i/o */ 2336 !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) { 2337 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 2338 zio_vdev_io_bypass(zio); 2339 return (ZIO_PIPELINE_CONTINUE); 2340 } 2341 2342 if (vd->vdev_ops->vdev_op_leaf && 2343 (zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE)) { 2344 2345 if (zio->io_type == ZIO_TYPE_READ && vdev_cache_read(zio) == 0) 2346 return (ZIO_PIPELINE_CONTINUE); 2347 2348 if ((zio = vdev_queue_io(zio)) == NULL) 2349 return (ZIO_PIPELINE_STOP); 2350 2351 if (!vdev_accessible(vd, zio)) { 2352 zio->io_error = ENXIO; 2353 zio_interrupt(zio); 2354 return (ZIO_PIPELINE_STOP); 2355 } 2356 } 2357 2358 return (vd->vdev_ops->vdev_op_io_start(zio)); 2359 } 2360 2361 static int 2362 zio_vdev_io_done(zio_t *zio) 2363 { 2364 vdev_t *vd = zio->io_vd; 2365 vdev_ops_t *ops = vd ? vd->vdev_ops : &vdev_mirror_ops; 2366 boolean_t unexpected_error = B_FALSE; 2367 2368 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 2369 return (ZIO_PIPELINE_STOP); 2370 2371 ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE); 2372 2373 if (vd != NULL && vd->vdev_ops->vdev_op_leaf) { 2374 2375 vdev_queue_io_done(zio); 2376 2377 if (zio->io_type == ZIO_TYPE_WRITE) 2378 vdev_cache_write(zio); 2379 2380 if (zio_injection_enabled && zio->io_error == 0) 2381 zio->io_error = zio_handle_device_injection(vd, 2382 zio, EIO); 2383 2384 if (zio_injection_enabled && zio->io_error == 0) 2385 zio->io_error = zio_handle_label_injection(zio, EIO); 2386 2387 if (zio->io_error) { 2388 if (!vdev_accessible(vd, zio)) { 2389 zio->io_error = ENXIO; 2390 } else { 2391 unexpected_error = B_TRUE; 2392 } 2393 } 2394 } 2395 2396 ops->vdev_op_io_done(zio); 2397 2398 if (unexpected_error) 2399 VERIFY(vdev_probe(vd, zio) == NULL); 2400 2401 return (ZIO_PIPELINE_CONTINUE); 2402 } 2403 2404 /* 2405 * For non-raidz ZIOs, we can just copy aside the bad data read from the 2406 * disk, and use that to finish the checksum ereport later. 2407 */ 2408 static void 2409 zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr, 2410 const void *good_buf) 2411 { 2412 /* no processing needed */ 2413 zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE); 2414 } 2415 2416 /*ARGSUSED*/ 2417 void 2418 zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *ignored) 2419 { 2420 void *buf = zio_buf_alloc(zio->io_size); 2421 2422 bcopy(zio->io_data, buf, zio->io_size); 2423 2424 zcr->zcr_cbinfo = zio->io_size; 2425 zcr->zcr_cbdata = buf; 2426 zcr->zcr_finish = zio_vsd_default_cksum_finish; 2427 zcr->zcr_free = zio_buf_free; 2428 } 2429 2430 static int 2431 zio_vdev_io_assess(zio_t *zio) 2432 { 2433 vdev_t *vd = zio->io_vd; 2434 2435 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 2436 return (ZIO_PIPELINE_STOP); 2437 2438 if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 2439 spa_config_exit(zio->io_spa, SCL_ZIO, zio); 2440 2441 if (zio->io_vsd != NULL) { 2442 zio->io_vsd_ops->vsd_free(zio); 2443 zio->io_vsd = NULL; 2444 } 2445 2446 if (zio_injection_enabled && zio->io_error == 0) 2447 zio->io_error = zio_handle_fault_injection(zio, EIO); 2448 2449 /* 2450 * If the I/O failed, determine whether we should attempt to retry it. 2451 * 2452 * On retry, we cut in line in the issue queue, since we don't want 2453 * compression/checksumming/etc. work to prevent our (cheap) IO reissue. 2454 */ 2455 if (zio->io_error && vd == NULL && 2456 !(zio->io_flags & (ZIO_FLAG_DONT_RETRY | ZIO_FLAG_IO_RETRY))) { 2457 ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_QUEUE)); /* not a leaf */ 2458 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_BYPASS)); /* not a leaf */ 2459 zio->io_error = 0; 2460 zio->io_flags |= ZIO_FLAG_IO_RETRY | 2461 ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE; 2462 zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1; 2463 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, 2464 zio_requeue_io_start_cut_in_line); 2465 return (ZIO_PIPELINE_STOP); 2466 } 2467 2468 /* 2469 * If we got an error on a leaf device, convert it to ENXIO 2470 * if the device is not accessible at all. 2471 */ 2472 if (zio->io_error && vd != NULL && vd->vdev_ops->vdev_op_leaf && 2473 !vdev_accessible(vd, zio)) 2474 zio->io_error = ENXIO; 2475 2476 /* 2477 * If we can't write to an interior vdev (mirror or RAID-Z), 2478 * set vdev_cant_write so that we stop trying to allocate from it. 2479 */ 2480 if (zio->io_error == ENXIO && zio->io_type == ZIO_TYPE_WRITE && 2481 vd != NULL && !vd->vdev_ops->vdev_op_leaf) 2482 vd->vdev_cant_write = B_TRUE; 2483 2484 if (zio->io_error) 2485 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2486 2487 return (ZIO_PIPELINE_CONTINUE); 2488 } 2489 2490 void 2491 zio_vdev_io_reissue(zio_t *zio) 2492 { 2493 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 2494 ASSERT(zio->io_error == 0); 2495 2496 zio->io_stage >>= 1; 2497 } 2498 2499 void 2500 zio_vdev_io_redone(zio_t *zio) 2501 { 2502 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE); 2503 2504 zio->io_stage >>= 1; 2505 } 2506 2507 void 2508 zio_vdev_io_bypass(zio_t *zio) 2509 { 2510 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 2511 ASSERT(zio->io_error == 0); 2512 2513 zio->io_flags |= ZIO_FLAG_IO_BYPASS; 2514 zio->io_stage = ZIO_STAGE_VDEV_IO_ASSESS >> 1; 2515 } 2516 2517 /* 2518 * ========================================================================== 2519 * Generate and verify checksums 2520 * ========================================================================== 2521 */ 2522 static int 2523 zio_checksum_generate(zio_t *zio) 2524 { 2525 blkptr_t *bp = zio->io_bp; 2526 enum zio_checksum checksum; 2527 2528 if (bp == NULL) { 2529 /* 2530 * This is zio_write_phys(). 2531 * We're either generating a label checksum, or none at all. 2532 */ 2533 checksum = zio->io_prop.zp_checksum; 2534 2535 if (checksum == ZIO_CHECKSUM_OFF) 2536 return (ZIO_PIPELINE_CONTINUE); 2537 2538 ASSERT(checksum == ZIO_CHECKSUM_LABEL); 2539 } else { 2540 if (BP_IS_GANG(bp) && zio->io_child_type == ZIO_CHILD_GANG) { 2541 ASSERT(!IO_IS_ALLOCATING(zio)); 2542 checksum = ZIO_CHECKSUM_GANG_HEADER; 2543 } else { 2544 checksum = BP_GET_CHECKSUM(bp); 2545 } 2546 } 2547 2548 zio_checksum_compute(zio, checksum, zio->io_data, zio->io_size); 2549 2550 return (ZIO_PIPELINE_CONTINUE); 2551 } 2552 2553 static int 2554 zio_checksum_verify(zio_t *zio) 2555 { 2556 zio_bad_cksum_t info; 2557 blkptr_t *bp = zio->io_bp; 2558 int error; 2559 2560 ASSERT(zio->io_vd != NULL); 2561 2562 if (bp == NULL) { 2563 /* 2564 * This is zio_read_phys(). 2565 * We're either verifying a label checksum, or nothing at all. 2566 */ 2567 if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF) 2568 return (ZIO_PIPELINE_CONTINUE); 2569 2570 ASSERT(zio->io_prop.zp_checksum == ZIO_CHECKSUM_LABEL); 2571 } 2572 2573 if ((error = zio_checksum_error(zio, &info)) != 0) { 2574 zio->io_error = error; 2575 if (!(zio->io_flags & ZIO_FLAG_SPECULATIVE)) { 2576 zfs_ereport_start_checksum(zio->io_spa, 2577 zio->io_vd, zio, zio->io_offset, 2578 zio->io_size, NULL, &info); 2579 } 2580 } 2581 2582 return (ZIO_PIPELINE_CONTINUE); 2583 } 2584 2585 /* 2586 * Called by RAID-Z to ensure we don't compute the checksum twice. 2587 */ 2588 void 2589 zio_checksum_verified(zio_t *zio) 2590 { 2591 zio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 2592 } 2593 2594 /* 2595 * ========================================================================== 2596 * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other. 2597 * An error of 0 indictes success. ENXIO indicates whole-device failure, 2598 * which may be transient (e.g. unplugged) or permament. ECKSUM and EIO 2599 * indicate errors that are specific to one I/O, and most likely permanent. 2600 * Any other error is presumed to be worse because we weren't expecting it. 2601 * ========================================================================== 2602 */ 2603 int 2604 zio_worst_error(int e1, int e2) 2605 { 2606 static int zio_error_rank[] = { 0, ENXIO, ECKSUM, EIO }; 2607 int r1, r2; 2608 2609 for (r1 = 0; r1 < sizeof (zio_error_rank) / sizeof (int); r1++) 2610 if (e1 == zio_error_rank[r1]) 2611 break; 2612 2613 for (r2 = 0; r2 < sizeof (zio_error_rank) / sizeof (int); r2++) 2614 if (e2 == zio_error_rank[r2]) 2615 break; 2616 2617 return (r1 > r2 ? e1 : e2); 2618 } 2619 2620 /* 2621 * ========================================================================== 2622 * I/O completion 2623 * ========================================================================== 2624 */ 2625 static int 2626 zio_ready(zio_t *zio) 2627 { 2628 blkptr_t *bp = zio->io_bp; 2629 zio_t *pio, *pio_next; 2630 2631 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 2632 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_READY)) 2633 return (ZIO_PIPELINE_STOP); 2634 2635 if (zio->io_ready) { 2636 ASSERT(IO_IS_ALLOCATING(zio)); 2637 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp)); 2638 ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0); 2639 2640 zio->io_ready(zio); 2641 } 2642 2643 if (bp != NULL && bp != &zio->io_bp_copy) 2644 zio->io_bp_copy = *bp; 2645 2646 if (zio->io_error) 2647 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2648 2649 mutex_enter(&zio->io_lock); 2650 zio->io_state[ZIO_WAIT_READY] = 1; 2651 pio = zio_walk_parents(zio); 2652 mutex_exit(&zio->io_lock); 2653 2654 /* 2655 * As we notify zio's parents, new parents could be added. 2656 * New parents go to the head of zio's io_parent_list, however, 2657 * so we will (correctly) not notify them. The remainder of zio's 2658 * io_parent_list, from 'pio_next' onward, cannot change because 2659 * all parents must wait for us to be done before they can be done. 2660 */ 2661 for (; pio != NULL; pio = pio_next) { 2662 pio_next = zio_walk_parents(zio); 2663 zio_notify_parent(pio, zio, ZIO_WAIT_READY); 2664 } 2665 2666 if (zio->io_flags & ZIO_FLAG_NODATA) { 2667 if (BP_IS_GANG(bp)) { 2668 zio->io_flags &= ~ZIO_FLAG_NODATA; 2669 } else { 2670 ASSERT((uintptr_t)zio->io_data < SPA_MAXBLOCKSIZE); 2671 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 2672 } 2673 } 2674 2675 if (zio_injection_enabled && 2676 zio->io_spa->spa_syncing_txg == zio->io_txg) 2677 zio_handle_ignored_writes(zio); 2678 2679 return (ZIO_PIPELINE_CONTINUE); 2680 } 2681 2682 static int 2683 zio_done(zio_t *zio) 2684 { 2685 spa_t *spa = zio->io_spa; 2686 zio_t *lio = zio->io_logical; 2687 blkptr_t *bp = zio->io_bp; 2688 vdev_t *vd = zio->io_vd; 2689 uint64_t psize = zio->io_size; 2690 zio_t *pio, *pio_next; 2691 2692 /* 2693 * If our children haven't all completed, 2694 * wait for them and then repeat this pipeline stage. 2695 */ 2696 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE) || 2697 zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE) || 2698 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE) || 2699 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_DONE)) 2700 return (ZIO_PIPELINE_STOP); 2701 2702 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 2703 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 2704 ASSERT(zio->io_children[c][w] == 0); 2705 2706 if (bp != NULL) { 2707 ASSERT(bp->blk_pad[0] == 0); 2708 ASSERT(bp->blk_pad[1] == 0); 2709 ASSERT(bcmp(bp, &zio->io_bp_copy, sizeof (blkptr_t)) == 0 || 2710 (bp == zio_unique_parent(zio)->io_bp)); 2711 if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(bp) && 2712 zio->io_bp_override == NULL && 2713 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) { 2714 ASSERT(!BP_SHOULD_BYTESWAP(bp)); 2715 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(bp)); 2716 ASSERT(BP_COUNT_GANG(bp) == 0 || 2717 (BP_COUNT_GANG(bp) == BP_GET_NDVAS(bp))); 2718 } 2719 } 2720 2721 /* 2722 * If there were child vdev/gang/ddt errors, they apply to us now. 2723 */ 2724 zio_inherit_child_errors(zio, ZIO_CHILD_VDEV); 2725 zio_inherit_child_errors(zio, ZIO_CHILD_GANG); 2726 zio_inherit_child_errors(zio, ZIO_CHILD_DDT); 2727 2728 /* 2729 * If the I/O on the transformed data was successful, generate any 2730 * checksum reports now while we still have the transformed data. 2731 */ 2732 if (zio->io_error == 0) { 2733 while (zio->io_cksum_report != NULL) { 2734 zio_cksum_report_t *zcr = zio->io_cksum_report; 2735 uint64_t align = zcr->zcr_align; 2736 uint64_t asize = P2ROUNDUP(psize, align); 2737 char *abuf = zio->io_data; 2738 2739 if (asize != psize) { 2740 abuf = zio_buf_alloc(asize); 2741 bcopy(zio->io_data, abuf, psize); 2742 bzero(abuf + psize, asize - psize); 2743 } 2744 2745 zio->io_cksum_report = zcr->zcr_next; 2746 zcr->zcr_next = NULL; 2747 zcr->zcr_finish(zcr, abuf); 2748 zfs_ereport_free_checksum(zcr); 2749 2750 if (asize != psize) 2751 zio_buf_free(abuf, asize); 2752 } 2753 } 2754 2755 zio_pop_transforms(zio); /* note: may set zio->io_error */ 2756 2757 vdev_stat_update(zio, psize); 2758 2759 if (zio->io_error) { 2760 /* 2761 * If this I/O is attached to a particular vdev, 2762 * generate an error message describing the I/O failure 2763 * at the block level. We ignore these errors if the 2764 * device is currently unavailable. 2765 */ 2766 if (zio->io_error != ECKSUM && vd != NULL && !vdev_is_dead(vd)) 2767 zfs_ereport_post(FM_EREPORT_ZFS_IO, spa, vd, zio, 0, 0); 2768 2769 if ((zio->io_error == EIO || !(zio->io_flags & 2770 (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) && 2771 zio == lio) { 2772 /* 2773 * For logical I/O requests, tell the SPA to log the 2774 * error and generate a logical data ereport. 2775 */ 2776 spa_log_error(spa, zio); 2777 zfs_ereport_post(FM_EREPORT_ZFS_DATA, spa, NULL, zio, 2778 0, 0); 2779 } 2780 } 2781 2782 if (zio->io_error && zio == lio) { 2783 /* 2784 * Determine whether zio should be reexecuted. This will 2785 * propagate all the way to the root via zio_notify_parent(). 2786 */ 2787 ASSERT(vd == NULL && bp != NULL); 2788 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2789 2790 if (IO_IS_ALLOCATING(zio) && 2791 !(zio->io_flags & ZIO_FLAG_CANFAIL)) { 2792 if (zio->io_error != ENOSPC) 2793 zio->io_reexecute |= ZIO_REEXECUTE_NOW; 2794 else 2795 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 2796 } 2797 2798 if ((zio->io_type == ZIO_TYPE_READ || 2799 zio->io_type == ZIO_TYPE_FREE) && 2800 !(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && 2801 zio->io_error == ENXIO && 2802 spa_load_state(spa) == SPA_LOAD_NONE && 2803 spa_get_failmode(spa) != ZIO_FAILURE_MODE_CONTINUE) 2804 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 2805 2806 if (!(zio->io_flags & ZIO_FLAG_CANFAIL) && !zio->io_reexecute) 2807 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 2808 2809 /* 2810 * Here is a possibly good place to attempt to do 2811 * either combinatorial reconstruction or error correction 2812 * based on checksums. It also might be a good place 2813 * to send out preliminary ereports before we suspend 2814 * processing. 2815 */ 2816 } 2817 2818 /* 2819 * If there were logical child errors, they apply to us now. 2820 * We defer this until now to avoid conflating logical child 2821 * errors with errors that happened to the zio itself when 2822 * updating vdev stats and reporting FMA events above. 2823 */ 2824 zio_inherit_child_errors(zio, ZIO_CHILD_LOGICAL); 2825 2826 if ((zio->io_error || zio->io_reexecute) && 2827 IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio && 2828 !(zio->io_flags & ZIO_FLAG_IO_REWRITE)) 2829 zio_dva_unallocate(zio, zio->io_gang_tree, bp); 2830 2831 zio_gang_tree_free(&zio->io_gang_tree); 2832 2833 /* 2834 * Godfather I/Os should never suspend. 2835 */ 2836 if ((zio->io_flags & ZIO_FLAG_GODFATHER) && 2837 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) 2838 zio->io_reexecute = 0; 2839 2840 if (zio->io_reexecute) { 2841 /* 2842 * This is a logical I/O that wants to reexecute. 2843 * 2844 * Reexecute is top-down. When an i/o fails, if it's not 2845 * the root, it simply notifies its parent and sticks around. 2846 * The parent, seeing that it still has children in zio_done(), 2847 * does the same. This percolates all the way up to the root. 2848 * The root i/o will reexecute or suspend the entire tree. 2849 * 2850 * This approach ensures that zio_reexecute() honors 2851 * all the original i/o dependency relationships, e.g. 2852 * parents not executing until children are ready. 2853 */ 2854 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2855 2856 zio->io_gang_leader = NULL; 2857 2858 mutex_enter(&zio->io_lock); 2859 zio->io_state[ZIO_WAIT_DONE] = 1; 2860 mutex_exit(&zio->io_lock); 2861 2862 /* 2863 * "The Godfather" I/O monitors its children but is 2864 * not a true parent to them. It will track them through 2865 * the pipeline but severs its ties whenever they get into 2866 * trouble (e.g. suspended). This allows "The Godfather" 2867 * I/O to return status without blocking. 2868 */ 2869 for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) { 2870 zio_link_t *zl = zio->io_walk_link; 2871 pio_next = zio_walk_parents(zio); 2872 2873 if ((pio->io_flags & ZIO_FLAG_GODFATHER) && 2874 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) { 2875 zio_remove_child(pio, zio, zl); 2876 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 2877 } 2878 } 2879 2880 if ((pio = zio_unique_parent(zio)) != NULL) { 2881 /* 2882 * We're not a root i/o, so there's nothing to do 2883 * but notify our parent. Don't propagate errors 2884 * upward since we haven't permanently failed yet. 2885 */ 2886 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 2887 zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE; 2888 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 2889 } else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) { 2890 /* 2891 * We'd fail again if we reexecuted now, so suspend 2892 * until conditions improve (e.g. device comes online). 2893 */ 2894 zio_suspend(spa, zio); 2895 } else { 2896 /* 2897 * Reexecution is potentially a huge amount of work. 2898 * Hand it off to the otherwise-unused claim taskq. 2899 */ 2900 ASSERT(zio->io_tqent.tqent_next == NULL); 2901 (void) taskq_dispatch_ent( 2902 spa->spa_zio_taskq[ZIO_TYPE_CLAIM][ZIO_TASKQ_ISSUE], 2903 (task_func_t *)zio_reexecute, zio, 0, 2904 &zio->io_tqent); 2905 } 2906 return (ZIO_PIPELINE_STOP); 2907 } 2908 2909 ASSERT(zio->io_child_count == 0); 2910 ASSERT(zio->io_reexecute == 0); 2911 ASSERT(zio->io_error == 0 || (zio->io_flags & ZIO_FLAG_CANFAIL)); 2912 2913 /* 2914 * Report any checksum errors, since the I/O is complete. 2915 */ 2916 while (zio->io_cksum_report != NULL) { 2917 zio_cksum_report_t *zcr = zio->io_cksum_report; 2918 zio->io_cksum_report = zcr->zcr_next; 2919 zcr->zcr_next = NULL; 2920 zcr->zcr_finish(zcr, NULL); 2921 zfs_ereport_free_checksum(zcr); 2922 } 2923 2924 /* 2925 * It is the responsibility of the done callback to ensure that this 2926 * particular zio is no longer discoverable for adoption, and as 2927 * such, cannot acquire any new parents. 2928 */ 2929 if (zio->io_done) 2930 zio->io_done(zio); 2931 2932 mutex_enter(&zio->io_lock); 2933 zio->io_state[ZIO_WAIT_DONE] = 1; 2934 mutex_exit(&zio->io_lock); 2935 2936 for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) { 2937 zio_link_t *zl = zio->io_walk_link; 2938 pio_next = zio_walk_parents(zio); 2939 zio_remove_child(pio, zio, zl); 2940 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 2941 } 2942 2943 if (zio->io_waiter != NULL) { 2944 mutex_enter(&zio->io_lock); 2945 zio->io_executor = NULL; 2946 cv_broadcast(&zio->io_cv); 2947 mutex_exit(&zio->io_lock); 2948 } else { 2949 zio_destroy(zio); 2950 } 2951 2952 return (ZIO_PIPELINE_STOP); 2953 } 2954 2955 /* 2956 * ========================================================================== 2957 * I/O pipeline definition 2958 * ========================================================================== 2959 */ 2960 static zio_pipe_stage_t *zio_pipeline[] = { 2961 NULL, 2962 zio_read_bp_init, 2963 zio_free_bp_init, 2964 zio_issue_async, 2965 zio_write_bp_init, 2966 zio_checksum_generate, 2967 zio_ddt_read_start, 2968 zio_ddt_read_done, 2969 zio_ddt_write, 2970 zio_ddt_free, 2971 zio_gang_assemble, 2972 zio_gang_issue, 2973 zio_dva_allocate, 2974 zio_dva_free, 2975 zio_dva_claim, 2976 zio_ready, 2977 zio_vdev_io_start, 2978 zio_vdev_io_done, 2979 zio_vdev_io_assess, 2980 zio_checksum_verify, 2981 zio_done 2982 }; 2983