1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2013 by Delphix. All rights reserved. 24 * 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 * The following actions directly effect the spa's sync-to-convergence logic. 87 * The values below define the sync pass when we start performing the action. 88 * Care should be taken when changing these values as they directly impact 89 * spa_sync() performance. Tuning these values may introduce subtle performance 90 * pathologies and should only be done in the context of performance analysis. 91 * These tunables will eventually be removed and replaced with #defines once 92 * enough analysis has been done to determine optimal values. 93 * 94 * The 'zfs_sync_pass_deferred_free' pass must be greater than 1 to ensure that 95 * regular blocks are not deferred. 96 */ 97 int zfs_sync_pass_deferred_free = 2; /* defer frees starting in this pass */ 98 int zfs_sync_pass_dont_compress = 5; /* don't compress starting in this pass */ 99 int zfs_sync_pass_rewrite = 2; /* rewrite new bps starting in this pass */ 100 101 /* 102 * An allocating zio is one that either currently has the DVA allocate 103 * stage set or will have it later in its lifetime. 104 */ 105 #define IO_IS_ALLOCATING(zio) ((zio)->io_orig_pipeline & ZIO_STAGE_DVA_ALLOCATE) 106 107 boolean_t zio_requeue_io_start_cut_in_line = B_TRUE; 108 109 #ifdef ZFS_DEBUG 110 int zio_buf_debug_limit = 16384; 111 #else 112 int zio_buf_debug_limit = 0; 113 #endif 114 115 void 116 zio_init(void) 117 { 118 size_t c; 119 vmem_t *data_alloc_arena = NULL; 120 121 #ifdef _KERNEL 122 data_alloc_arena = zio_alloc_arena; 123 #endif 124 zio_cache = kmem_cache_create("zio_cache", 125 sizeof (zio_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 126 zio_link_cache = kmem_cache_create("zio_link_cache", 127 sizeof (zio_link_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 128 129 /* 130 * For small buffers, we want a cache for each multiple of 131 * SPA_MINBLOCKSIZE. For medium-size buffers, we want a cache 132 * for each quarter-power of 2. For large buffers, we want 133 * a cache for each multiple of PAGESIZE. 134 */ 135 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { 136 size_t size = (c + 1) << SPA_MINBLOCKSHIFT; 137 size_t p2 = size; 138 size_t align = 0; 139 size_t cflags = (size > zio_buf_debug_limit) ? KMC_NODEBUG : 0; 140 141 while (p2 & (p2 - 1)) 142 p2 &= p2 - 1; 143 144 #ifndef _KERNEL 145 /* 146 * If we are using watchpoints, put each buffer on its own page, 147 * to eliminate the performance overhead of trapping to the 148 * kernel when modifying a non-watched buffer that shares the 149 * page with a watched buffer. 150 */ 151 if (arc_watch && !IS_P2ALIGNED(size, PAGESIZE)) 152 continue; 153 #endif 154 if (size <= 4 * SPA_MINBLOCKSIZE) { 155 align = SPA_MINBLOCKSIZE; 156 } else if (IS_P2ALIGNED(size, PAGESIZE)) { 157 align = PAGESIZE; 158 } else if (IS_P2ALIGNED(size, p2 >> 2)) { 159 align = p2 >> 2; 160 } 161 162 if (align != 0) { 163 char name[36]; 164 (void) sprintf(name, "zio_buf_%lu", (ulong_t)size); 165 zio_buf_cache[c] = kmem_cache_create(name, size, 166 align, NULL, NULL, NULL, NULL, NULL, cflags); 167 168 /* 169 * Since zio_data bufs do not appear in crash dumps, we 170 * pass KMC_NOTOUCH so that no allocator metadata is 171 * stored with the buffers. 172 */ 173 (void) sprintf(name, "zio_data_buf_%lu", (ulong_t)size); 174 zio_data_buf_cache[c] = kmem_cache_create(name, size, 175 align, NULL, NULL, NULL, NULL, data_alloc_arena, 176 cflags | KMC_NOTOUCH); 177 } 178 } 179 180 while (--c != 0) { 181 ASSERT(zio_buf_cache[c] != NULL); 182 if (zio_buf_cache[c - 1] == NULL) 183 zio_buf_cache[c - 1] = zio_buf_cache[c]; 184 185 ASSERT(zio_data_buf_cache[c] != NULL); 186 if (zio_data_buf_cache[c - 1] == NULL) 187 zio_data_buf_cache[c - 1] = zio_data_buf_cache[c]; 188 } 189 190 /* 191 * The zio write taskqs have 1 thread per cpu, allow 1/2 of the taskqs 192 * to fail 3 times per txg or 8 failures, whichever is greater. 193 */ 194 zfs_mg_alloc_failures = MAX((3 * max_ncpus / 2), 8); 195 196 zio_inject_init(); 197 } 198 199 void 200 zio_fini(void) 201 { 202 size_t c; 203 kmem_cache_t *last_cache = NULL; 204 kmem_cache_t *last_data_cache = NULL; 205 206 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { 207 if (zio_buf_cache[c] != last_cache) { 208 last_cache = zio_buf_cache[c]; 209 kmem_cache_destroy(zio_buf_cache[c]); 210 } 211 zio_buf_cache[c] = NULL; 212 213 if (zio_data_buf_cache[c] != last_data_cache) { 214 last_data_cache = zio_data_buf_cache[c]; 215 kmem_cache_destroy(zio_data_buf_cache[c]); 216 } 217 zio_data_buf_cache[c] = NULL; 218 } 219 220 kmem_cache_destroy(zio_link_cache); 221 kmem_cache_destroy(zio_cache); 222 223 zio_inject_fini(); 224 } 225 226 /* 227 * ========================================================================== 228 * Allocate and free I/O buffers 229 * ========================================================================== 230 */ 231 232 /* 233 * Use zio_buf_alloc to allocate ZFS metadata. This data will appear in a 234 * crashdump if the kernel panics, so use it judiciously. Obviously, it's 235 * useful to inspect ZFS metadata, but if possible, we should avoid keeping 236 * excess / transient data in-core during a crashdump. 237 */ 238 void * 239 zio_buf_alloc(size_t size) 240 { 241 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 242 243 ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 244 245 return (kmem_cache_alloc(zio_buf_cache[c], KM_PUSHPAGE)); 246 } 247 248 /* 249 * Use zio_data_buf_alloc to allocate data. The data will not appear in a 250 * crashdump if the kernel panics. This exists so that we will limit the amount 251 * of ZFS data that shows up in a kernel crashdump. (Thus reducing the amount 252 * of kernel heap dumped to disk when the kernel panics) 253 */ 254 void * 255 zio_data_buf_alloc(size_t size) 256 { 257 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 258 259 ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 260 261 return (kmem_cache_alloc(zio_data_buf_cache[c], KM_PUSHPAGE)); 262 } 263 264 void 265 zio_buf_free(void *buf, size_t size) 266 { 267 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 268 269 ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 270 271 kmem_cache_free(zio_buf_cache[c], buf); 272 } 273 274 void 275 zio_data_buf_free(void *buf, size_t size) 276 { 277 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 278 279 ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 280 281 kmem_cache_free(zio_data_buf_cache[c], buf); 282 } 283 284 /* 285 * ========================================================================== 286 * Push and pop I/O transform buffers 287 * ========================================================================== 288 */ 289 static void 290 zio_push_transform(zio_t *zio, void *data, uint64_t size, uint64_t bufsize, 291 zio_transform_func_t *transform) 292 { 293 zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP); 294 295 zt->zt_orig_data = zio->io_data; 296 zt->zt_orig_size = zio->io_size; 297 zt->zt_bufsize = bufsize; 298 zt->zt_transform = transform; 299 300 zt->zt_next = zio->io_transform_stack; 301 zio->io_transform_stack = zt; 302 303 zio->io_data = data; 304 zio->io_size = size; 305 } 306 307 static void 308 zio_pop_transforms(zio_t *zio) 309 { 310 zio_transform_t *zt; 311 312 while ((zt = zio->io_transform_stack) != NULL) { 313 if (zt->zt_transform != NULL) 314 zt->zt_transform(zio, 315 zt->zt_orig_data, zt->zt_orig_size); 316 317 if (zt->zt_bufsize != 0) 318 zio_buf_free(zio->io_data, zt->zt_bufsize); 319 320 zio->io_data = zt->zt_orig_data; 321 zio->io_size = zt->zt_orig_size; 322 zio->io_transform_stack = zt->zt_next; 323 324 kmem_free(zt, sizeof (zio_transform_t)); 325 } 326 } 327 328 /* 329 * ========================================================================== 330 * I/O transform callbacks for subblocks and decompression 331 * ========================================================================== 332 */ 333 static void 334 zio_subblock(zio_t *zio, void *data, uint64_t size) 335 { 336 ASSERT(zio->io_size > size); 337 338 if (zio->io_type == ZIO_TYPE_READ) 339 bcopy(zio->io_data, data, size); 340 } 341 342 static void 343 zio_decompress(zio_t *zio, void *data, uint64_t size) 344 { 345 if (zio->io_error == 0 && 346 zio_decompress_data(BP_GET_COMPRESS(zio->io_bp), 347 zio->io_data, data, zio->io_size, size) != 0) 348 zio->io_error = SET_ERROR(EIO); 349 } 350 351 /* 352 * ========================================================================== 353 * I/O parent/child relationships and pipeline interlocks 354 * ========================================================================== 355 */ 356 /* 357 * NOTE - Callers to zio_walk_parents() and zio_walk_children must 358 * continue calling these functions until they return NULL. 359 * Otherwise, the next caller will pick up the list walk in 360 * some indeterminate state. (Otherwise every caller would 361 * have to pass in a cookie to keep the state represented by 362 * io_walk_link, which gets annoying.) 363 */ 364 zio_t * 365 zio_walk_parents(zio_t *cio) 366 { 367 zio_link_t *zl = cio->io_walk_link; 368 list_t *pl = &cio->io_parent_list; 369 370 zl = (zl == NULL) ? list_head(pl) : list_next(pl, zl); 371 cio->io_walk_link = zl; 372 373 if (zl == NULL) 374 return (NULL); 375 376 ASSERT(zl->zl_child == cio); 377 return (zl->zl_parent); 378 } 379 380 zio_t * 381 zio_walk_children(zio_t *pio) 382 { 383 zio_link_t *zl = pio->io_walk_link; 384 list_t *cl = &pio->io_child_list; 385 386 zl = (zl == NULL) ? list_head(cl) : list_next(cl, zl); 387 pio->io_walk_link = zl; 388 389 if (zl == NULL) 390 return (NULL); 391 392 ASSERT(zl->zl_parent == pio); 393 return (zl->zl_child); 394 } 395 396 zio_t * 397 zio_unique_parent(zio_t *cio) 398 { 399 zio_t *pio = zio_walk_parents(cio); 400 401 VERIFY(zio_walk_parents(cio) == NULL); 402 return (pio); 403 } 404 405 void 406 zio_add_child(zio_t *pio, zio_t *cio) 407 { 408 zio_link_t *zl = kmem_cache_alloc(zio_link_cache, KM_SLEEP); 409 410 /* 411 * Logical I/Os can have logical, gang, or vdev children. 412 * Gang I/Os can have gang or vdev children. 413 * Vdev I/Os can only have vdev children. 414 * The following ASSERT captures all of these constraints. 415 */ 416 ASSERT(cio->io_child_type <= pio->io_child_type); 417 418 zl->zl_parent = pio; 419 zl->zl_child = cio; 420 421 mutex_enter(&cio->io_lock); 422 mutex_enter(&pio->io_lock); 423 424 ASSERT(pio->io_state[ZIO_WAIT_DONE] == 0); 425 426 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 427 pio->io_children[cio->io_child_type][w] += !cio->io_state[w]; 428 429 list_insert_head(&pio->io_child_list, zl); 430 list_insert_head(&cio->io_parent_list, zl); 431 432 pio->io_child_count++; 433 cio->io_parent_count++; 434 435 mutex_exit(&pio->io_lock); 436 mutex_exit(&cio->io_lock); 437 } 438 439 static void 440 zio_remove_child(zio_t *pio, zio_t *cio, zio_link_t *zl) 441 { 442 ASSERT(zl->zl_parent == pio); 443 ASSERT(zl->zl_child == cio); 444 445 mutex_enter(&cio->io_lock); 446 mutex_enter(&pio->io_lock); 447 448 list_remove(&pio->io_child_list, zl); 449 list_remove(&cio->io_parent_list, zl); 450 451 pio->io_child_count--; 452 cio->io_parent_count--; 453 454 mutex_exit(&pio->io_lock); 455 mutex_exit(&cio->io_lock); 456 457 kmem_cache_free(zio_link_cache, zl); 458 } 459 460 static boolean_t 461 zio_wait_for_children(zio_t *zio, enum zio_child child, enum zio_wait_type wait) 462 { 463 uint64_t *countp = &zio->io_children[child][wait]; 464 boolean_t waiting = B_FALSE; 465 466 mutex_enter(&zio->io_lock); 467 ASSERT(zio->io_stall == NULL); 468 if (*countp != 0) { 469 zio->io_stage >>= 1; 470 zio->io_stall = countp; 471 waiting = B_TRUE; 472 } 473 mutex_exit(&zio->io_lock); 474 475 return (waiting); 476 } 477 478 static void 479 zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait) 480 { 481 uint64_t *countp = &pio->io_children[zio->io_child_type][wait]; 482 int *errorp = &pio->io_child_error[zio->io_child_type]; 483 484 mutex_enter(&pio->io_lock); 485 if (zio->io_error && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE)) 486 *errorp = zio_worst_error(*errorp, zio->io_error); 487 pio->io_reexecute |= zio->io_reexecute; 488 ASSERT3U(*countp, >, 0); 489 if (--*countp == 0 && pio->io_stall == countp) { 490 pio->io_stall = NULL; 491 mutex_exit(&pio->io_lock); 492 zio_execute(pio); 493 } else { 494 mutex_exit(&pio->io_lock); 495 } 496 } 497 498 static void 499 zio_inherit_child_errors(zio_t *zio, enum zio_child c) 500 { 501 if (zio->io_child_error[c] != 0 && zio->io_error == 0) 502 zio->io_error = zio->io_child_error[c]; 503 } 504 505 /* 506 * ========================================================================== 507 * Create the various types of I/O (read, write, free, etc) 508 * ========================================================================== 509 */ 510 static zio_t * 511 zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 512 void *data, uint64_t size, zio_done_func_t *done, void *private, 513 zio_type_t type, int priority, enum zio_flag flags, 514 vdev_t *vd, uint64_t offset, const zbookmark_t *zb, 515 enum zio_stage stage, enum zio_stage pipeline) 516 { 517 zio_t *zio; 518 519 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 520 ASSERT(P2PHASE(size, SPA_MINBLOCKSIZE) == 0); 521 ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0); 522 523 ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER)); 524 ASSERT(!bp || !(flags & ZIO_FLAG_CONFIG_WRITER)); 525 ASSERT(vd || stage == ZIO_STAGE_OPEN); 526 527 zio = kmem_cache_alloc(zio_cache, KM_SLEEP); 528 bzero(zio, sizeof (zio_t)); 529 530 mutex_init(&zio->io_lock, NULL, MUTEX_DEFAULT, NULL); 531 cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL); 532 533 list_create(&zio->io_parent_list, sizeof (zio_link_t), 534 offsetof(zio_link_t, zl_parent_node)); 535 list_create(&zio->io_child_list, sizeof (zio_link_t), 536 offsetof(zio_link_t, zl_child_node)); 537 538 if (vd != NULL) 539 zio->io_child_type = ZIO_CHILD_VDEV; 540 else if (flags & ZIO_FLAG_GANG_CHILD) 541 zio->io_child_type = ZIO_CHILD_GANG; 542 else if (flags & ZIO_FLAG_DDT_CHILD) 543 zio->io_child_type = ZIO_CHILD_DDT; 544 else 545 zio->io_child_type = ZIO_CHILD_LOGICAL; 546 547 if (bp != NULL) { 548 zio->io_bp = (blkptr_t *)bp; 549 zio->io_bp_copy = *bp; 550 zio->io_bp_orig = *bp; 551 if (type != ZIO_TYPE_WRITE || 552 zio->io_child_type == ZIO_CHILD_DDT) 553 zio->io_bp = &zio->io_bp_copy; /* so caller can free */ 554 if (zio->io_child_type == ZIO_CHILD_LOGICAL) 555 zio->io_logical = zio; 556 if (zio->io_child_type > ZIO_CHILD_GANG && BP_IS_GANG(bp)) 557 pipeline |= ZIO_GANG_STAGES; 558 } 559 560 zio->io_spa = spa; 561 zio->io_txg = txg; 562 zio->io_done = done; 563 zio->io_private = private; 564 zio->io_type = type; 565 zio->io_priority = priority; 566 zio->io_vd = vd; 567 zio->io_offset = offset; 568 zio->io_orig_data = zio->io_data = data; 569 zio->io_orig_size = zio->io_size = size; 570 zio->io_orig_flags = zio->io_flags = flags; 571 zio->io_orig_stage = zio->io_stage = stage; 572 zio->io_orig_pipeline = zio->io_pipeline = pipeline; 573 574 zio->io_state[ZIO_WAIT_READY] = (stage >= ZIO_STAGE_READY); 575 zio->io_state[ZIO_WAIT_DONE] = (stage >= ZIO_STAGE_DONE); 576 577 if (zb != NULL) 578 zio->io_bookmark = *zb; 579 580 if (pio != NULL) { 581 if (zio->io_logical == NULL) 582 zio->io_logical = pio->io_logical; 583 if (zio->io_child_type == ZIO_CHILD_GANG) 584 zio->io_gang_leader = pio->io_gang_leader; 585 zio_add_child(pio, zio); 586 } 587 588 return (zio); 589 } 590 591 static void 592 zio_destroy(zio_t *zio) 593 { 594 list_destroy(&zio->io_parent_list); 595 list_destroy(&zio->io_child_list); 596 mutex_destroy(&zio->io_lock); 597 cv_destroy(&zio->io_cv); 598 kmem_cache_free(zio_cache, zio); 599 } 600 601 zio_t * 602 zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, zio_done_func_t *done, 603 void *private, enum zio_flag flags) 604 { 605 zio_t *zio; 606 607 zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private, 608 ZIO_TYPE_NULL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL, 609 ZIO_STAGE_OPEN, ZIO_INTERLOCK_PIPELINE); 610 611 return (zio); 612 } 613 614 zio_t * 615 zio_root(spa_t *spa, zio_done_func_t *done, void *private, enum zio_flag flags) 616 { 617 return (zio_null(NULL, spa, NULL, done, private, flags)); 618 } 619 620 zio_t * 621 zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, 622 void *data, uint64_t size, zio_done_func_t *done, void *private, 623 int priority, enum zio_flag flags, const zbookmark_t *zb) 624 { 625 zio_t *zio; 626 627 zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp, 628 data, size, done, private, 629 ZIO_TYPE_READ, priority, flags, NULL, 0, zb, 630 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 631 ZIO_DDT_CHILD_READ_PIPELINE : ZIO_READ_PIPELINE); 632 633 return (zio); 634 } 635 636 zio_t * 637 zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, 638 void *data, uint64_t size, const zio_prop_t *zp, 639 zio_done_func_t *ready, zio_done_func_t *done, void *private, 640 int priority, enum zio_flag flags, const zbookmark_t *zb) 641 { 642 zio_t *zio; 643 644 ASSERT(zp->zp_checksum >= ZIO_CHECKSUM_OFF && 645 zp->zp_checksum < ZIO_CHECKSUM_FUNCTIONS && 646 zp->zp_compress >= ZIO_COMPRESS_OFF && 647 zp->zp_compress < ZIO_COMPRESS_FUNCTIONS && 648 DMU_OT_IS_VALID(zp->zp_type) && 649 zp->zp_level < 32 && 650 zp->zp_copies > 0 && 651 zp->zp_copies <= spa_max_replication(spa)); 652 653 zio = zio_create(pio, spa, txg, bp, data, size, done, private, 654 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 655 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 656 ZIO_DDT_CHILD_WRITE_PIPELINE : ZIO_WRITE_PIPELINE); 657 658 zio->io_ready = ready; 659 zio->io_prop = *zp; 660 661 return (zio); 662 } 663 664 zio_t * 665 zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, void *data, 666 uint64_t size, zio_done_func_t *done, void *private, int priority, 667 enum zio_flag flags, zbookmark_t *zb) 668 { 669 zio_t *zio; 670 671 zio = zio_create(pio, spa, txg, bp, data, size, done, private, 672 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 673 ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE); 674 675 return (zio); 676 } 677 678 void 679 zio_write_override(zio_t *zio, blkptr_t *bp, int copies, boolean_t nopwrite) 680 { 681 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 682 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 683 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 684 ASSERT(zio->io_txg == spa_syncing_txg(zio->io_spa)); 685 686 /* 687 * We must reset the io_prop to match the values that existed 688 * when the bp was first written by dmu_sync() keeping in mind 689 * that nopwrite and dedup are mutually exclusive. 690 */ 691 zio->io_prop.zp_dedup = nopwrite ? B_FALSE : zio->io_prop.zp_dedup; 692 zio->io_prop.zp_nopwrite = nopwrite; 693 zio->io_prop.zp_copies = copies; 694 zio->io_bp_override = bp; 695 } 696 697 void 698 zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp) 699 { 700 metaslab_check_free(spa, bp); 701 bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp); 702 } 703 704 zio_t * 705 zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 706 enum zio_flag flags) 707 { 708 zio_t *zio; 709 710 dprintf_bp(bp, "freeing in txg %llu, pass %u", 711 (longlong_t)txg, spa->spa_sync_pass); 712 713 ASSERT(!BP_IS_HOLE(bp)); 714 ASSERT(spa_syncing_txg(spa) == txg); 715 ASSERT(spa_sync_pass(spa) < zfs_sync_pass_deferred_free); 716 717 metaslab_check_free(spa, bp); 718 719 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 720 NULL, NULL, ZIO_TYPE_FREE, ZIO_PRIORITY_FREE, flags, 721 NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_FREE_PIPELINE); 722 723 return (zio); 724 } 725 726 zio_t * 727 zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 728 zio_done_func_t *done, void *private, enum zio_flag flags) 729 { 730 zio_t *zio; 731 732 /* 733 * A claim is an allocation of a specific block. Claims are needed 734 * to support immediate writes in the intent log. The issue is that 735 * immediate writes contain committed data, but in a txg that was 736 * *not* committed. Upon opening the pool after an unclean shutdown, 737 * the intent log claims all blocks that contain immediate write data 738 * so that the SPA knows they're in use. 739 * 740 * All claims *must* be resolved in the first txg -- before the SPA 741 * starts allocating blocks -- so that nothing is allocated twice. 742 * If txg == 0 we just verify that the block is claimable. 743 */ 744 ASSERT3U(spa->spa_uberblock.ub_rootbp.blk_birth, <, spa_first_txg(spa)); 745 ASSERT(txg == spa_first_txg(spa) || txg == 0); 746 ASSERT(!BP_GET_DEDUP(bp) || !spa_writeable(spa)); /* zdb(1M) */ 747 748 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 749 done, private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW, flags, 750 NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE); 751 752 return (zio); 753 } 754 755 zio_t * 756 zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd, 757 zio_done_func_t *done, void *private, int priority, enum zio_flag flags) 758 { 759 zio_t *zio; 760 int c; 761 762 if (vd->vdev_children == 0) { 763 zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private, 764 ZIO_TYPE_IOCTL, priority, flags, vd, 0, NULL, 765 ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE); 766 767 zio->io_cmd = cmd; 768 } else { 769 zio = zio_null(pio, spa, NULL, NULL, NULL, flags); 770 771 for (c = 0; c < vd->vdev_children; c++) 772 zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd, 773 done, private, priority, flags)); 774 } 775 776 return (zio); 777 } 778 779 zio_t * 780 zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 781 void *data, int checksum, zio_done_func_t *done, void *private, 782 int priority, enum zio_flag flags, boolean_t labels) 783 { 784 zio_t *zio; 785 786 ASSERT(vd->vdev_children == 0); 787 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 788 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 789 ASSERT3U(offset + size, <=, vd->vdev_psize); 790 791 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private, 792 ZIO_TYPE_READ, priority, flags, vd, offset, NULL, 793 ZIO_STAGE_OPEN, ZIO_READ_PHYS_PIPELINE); 794 795 zio->io_prop.zp_checksum = checksum; 796 797 return (zio); 798 } 799 800 zio_t * 801 zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 802 void *data, int checksum, zio_done_func_t *done, void *private, 803 int priority, enum zio_flag flags, boolean_t labels) 804 { 805 zio_t *zio; 806 807 ASSERT(vd->vdev_children == 0); 808 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 809 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 810 ASSERT3U(offset + size, <=, vd->vdev_psize); 811 812 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private, 813 ZIO_TYPE_WRITE, priority, flags, vd, offset, NULL, 814 ZIO_STAGE_OPEN, ZIO_WRITE_PHYS_PIPELINE); 815 816 zio->io_prop.zp_checksum = checksum; 817 818 if (zio_checksum_table[checksum].ci_eck) { 819 /* 820 * zec checksums are necessarily destructive -- they modify 821 * the end of the write buffer to hold the verifier/checksum. 822 * Therefore, we must make a local copy in case the data is 823 * being written to multiple places in parallel. 824 */ 825 void *wbuf = zio_buf_alloc(size); 826 bcopy(data, wbuf, size); 827 zio_push_transform(zio, wbuf, size, size, NULL); 828 } 829 830 return (zio); 831 } 832 833 /* 834 * Create a child I/O to do some work for us. 835 */ 836 zio_t * 837 zio_vdev_child_io(zio_t *pio, blkptr_t *bp, vdev_t *vd, uint64_t offset, 838 void *data, uint64_t size, int type, int priority, enum zio_flag flags, 839 zio_done_func_t *done, void *private) 840 { 841 enum zio_stage pipeline = ZIO_VDEV_CHILD_PIPELINE; 842 zio_t *zio; 843 844 ASSERT(vd->vdev_parent == 845 (pio->io_vd ? pio->io_vd : pio->io_spa->spa_root_vdev)); 846 847 if (type == ZIO_TYPE_READ && bp != NULL) { 848 /* 849 * If we have the bp, then the child should perform the 850 * checksum and the parent need not. This pushes error 851 * detection as close to the leaves as possible and 852 * eliminates redundant checksums in the interior nodes. 853 */ 854 pipeline |= ZIO_STAGE_CHECKSUM_VERIFY; 855 pio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 856 } 857 858 if (vd->vdev_children == 0) 859 offset += VDEV_LABEL_START_SIZE; 860 861 flags |= ZIO_VDEV_CHILD_FLAGS(pio) | ZIO_FLAG_DONT_PROPAGATE; 862 863 /* 864 * If we've decided to do a repair, the write is not speculative -- 865 * even if the original read was. 866 */ 867 if (flags & ZIO_FLAG_IO_REPAIR) 868 flags &= ~ZIO_FLAG_SPECULATIVE; 869 870 zio = zio_create(pio, pio->io_spa, pio->io_txg, bp, data, size, 871 done, private, type, priority, flags, vd, offset, &pio->io_bookmark, 872 ZIO_STAGE_VDEV_IO_START >> 1, pipeline); 873 874 return (zio); 875 } 876 877 zio_t * 878 zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, void *data, uint64_t size, 879 int type, int priority, enum zio_flag flags, 880 zio_done_func_t *done, void *private) 881 { 882 zio_t *zio; 883 884 ASSERT(vd->vdev_ops->vdev_op_leaf); 885 886 zio = zio_create(NULL, vd->vdev_spa, 0, NULL, 887 data, size, done, private, type, priority, 888 flags | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY, 889 vd, offset, NULL, 890 ZIO_STAGE_VDEV_IO_START >> 1, ZIO_VDEV_CHILD_PIPELINE); 891 892 return (zio); 893 } 894 895 void 896 zio_flush(zio_t *zio, vdev_t *vd) 897 { 898 zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE, 899 NULL, NULL, ZIO_PRIORITY_NOW, 900 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY)); 901 } 902 903 void 904 zio_shrink(zio_t *zio, uint64_t size) 905 { 906 ASSERT(zio->io_executor == NULL); 907 ASSERT(zio->io_orig_size == zio->io_size); 908 ASSERT(size <= zio->io_size); 909 910 /* 911 * We don't shrink for raidz because of problems with the 912 * reconstruction when reading back less than the block size. 913 * Note, BP_IS_RAIDZ() assumes no compression. 914 */ 915 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 916 if (!BP_IS_RAIDZ(zio->io_bp)) 917 zio->io_orig_size = zio->io_size = size; 918 } 919 920 /* 921 * ========================================================================== 922 * Prepare to read and write logical blocks 923 * ========================================================================== 924 */ 925 926 static int 927 zio_read_bp_init(zio_t *zio) 928 { 929 blkptr_t *bp = zio->io_bp; 930 931 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF && 932 zio->io_child_type == ZIO_CHILD_LOGICAL && 933 !(zio->io_flags & ZIO_FLAG_RAW)) { 934 uint64_t psize = BP_GET_PSIZE(bp); 935 void *cbuf = zio_buf_alloc(psize); 936 937 zio_push_transform(zio, cbuf, psize, psize, zio_decompress); 938 } 939 940 if (!DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) && BP_GET_LEVEL(bp) == 0) 941 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 942 943 if (BP_GET_TYPE(bp) == DMU_OT_DDT_ZAP) 944 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 945 946 if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL) 947 zio->io_pipeline = ZIO_DDT_READ_PIPELINE; 948 949 return (ZIO_PIPELINE_CONTINUE); 950 } 951 952 static int 953 zio_write_bp_init(zio_t *zio) 954 { 955 spa_t *spa = zio->io_spa; 956 zio_prop_t *zp = &zio->io_prop; 957 enum zio_compress compress = zp->zp_compress; 958 blkptr_t *bp = zio->io_bp; 959 uint64_t lsize = zio->io_size; 960 uint64_t psize = lsize; 961 int pass = 1; 962 963 /* 964 * If our children haven't all reached the ready stage, 965 * wait for them and then repeat this pipeline stage. 966 */ 967 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 968 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_READY)) 969 return (ZIO_PIPELINE_STOP); 970 971 if (!IO_IS_ALLOCATING(zio)) 972 return (ZIO_PIPELINE_CONTINUE); 973 974 ASSERT(zio->io_child_type != ZIO_CHILD_DDT); 975 976 if (zio->io_bp_override) { 977 ASSERT(bp->blk_birth != zio->io_txg); 978 ASSERT(BP_GET_DEDUP(zio->io_bp_override) == 0); 979 980 *bp = *zio->io_bp_override; 981 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 982 983 /* 984 * If we've been overridden and nopwrite is set then 985 * set the flag accordingly to indicate that a nopwrite 986 * has already occurred. 987 */ 988 if (!BP_IS_HOLE(bp) && zp->zp_nopwrite) { 989 ASSERT(!zp->zp_dedup); 990 zio->io_flags |= ZIO_FLAG_NOPWRITE; 991 return (ZIO_PIPELINE_CONTINUE); 992 } 993 994 ASSERT(!zp->zp_nopwrite); 995 996 if (BP_IS_HOLE(bp) || !zp->zp_dedup) 997 return (ZIO_PIPELINE_CONTINUE); 998 999 ASSERT(zio_checksum_table[zp->zp_checksum].ci_dedup || 1000 zp->zp_dedup_verify); 1001 1002 if (BP_GET_CHECKSUM(bp) == zp->zp_checksum) { 1003 BP_SET_DEDUP(bp, 1); 1004 zio->io_pipeline |= ZIO_STAGE_DDT_WRITE; 1005 return (ZIO_PIPELINE_CONTINUE); 1006 } 1007 zio->io_bp_override = NULL; 1008 BP_ZERO(bp); 1009 } 1010 1011 if (bp->blk_birth == zio->io_txg) { 1012 /* 1013 * We're rewriting an existing block, which means we're 1014 * working on behalf of spa_sync(). For spa_sync() to 1015 * converge, it must eventually be the case that we don't 1016 * have to allocate new blocks. But compression changes 1017 * the blocksize, which forces a reallocate, and makes 1018 * convergence take longer. Therefore, after the first 1019 * few passes, stop compressing to ensure convergence. 1020 */ 1021 pass = spa_sync_pass(spa); 1022 1023 ASSERT(zio->io_txg == spa_syncing_txg(spa)); 1024 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1025 ASSERT(!BP_GET_DEDUP(bp)); 1026 1027 if (pass >= zfs_sync_pass_dont_compress) 1028 compress = ZIO_COMPRESS_OFF; 1029 1030 /* Make sure someone doesn't change their mind on overwrites */ 1031 ASSERT(MIN(zp->zp_copies + BP_IS_GANG(bp), 1032 spa_max_replication(spa)) == BP_GET_NDVAS(bp)); 1033 } 1034 1035 if (compress != ZIO_COMPRESS_OFF) { 1036 void *cbuf = zio_buf_alloc(lsize); 1037 psize = zio_compress_data(compress, zio->io_data, cbuf, lsize); 1038 if (psize == 0 || psize == lsize) { 1039 compress = ZIO_COMPRESS_OFF; 1040 zio_buf_free(cbuf, lsize); 1041 } else { 1042 ASSERT(psize < lsize); 1043 zio_push_transform(zio, cbuf, psize, lsize, NULL); 1044 } 1045 } 1046 1047 /* 1048 * The final pass of spa_sync() must be all rewrites, but the first 1049 * few passes offer a trade-off: allocating blocks defers convergence, 1050 * but newly allocated blocks are sequential, so they can be written 1051 * to disk faster. Therefore, we allow the first few passes of 1052 * spa_sync() to allocate new blocks, but force rewrites after that. 1053 * There should only be a handful of blocks after pass 1 in any case. 1054 */ 1055 if (bp->blk_birth == zio->io_txg && BP_GET_PSIZE(bp) == psize && 1056 pass >= zfs_sync_pass_rewrite) { 1057 ASSERT(psize != 0); 1058 enum zio_stage gang_stages = zio->io_pipeline & ZIO_GANG_STAGES; 1059 zio->io_pipeline = ZIO_REWRITE_PIPELINE | gang_stages; 1060 zio->io_flags |= ZIO_FLAG_IO_REWRITE; 1061 } else { 1062 BP_ZERO(bp); 1063 zio->io_pipeline = ZIO_WRITE_PIPELINE; 1064 } 1065 1066 if (psize == 0) { 1067 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1068 } else { 1069 ASSERT(zp->zp_checksum != ZIO_CHECKSUM_GANG_HEADER); 1070 BP_SET_LSIZE(bp, lsize); 1071 BP_SET_PSIZE(bp, psize); 1072 BP_SET_COMPRESS(bp, compress); 1073 BP_SET_CHECKSUM(bp, zp->zp_checksum); 1074 BP_SET_TYPE(bp, zp->zp_type); 1075 BP_SET_LEVEL(bp, zp->zp_level); 1076 BP_SET_DEDUP(bp, zp->zp_dedup); 1077 BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER); 1078 if (zp->zp_dedup) { 1079 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1080 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1081 zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE; 1082 } 1083 if (zp->zp_nopwrite) { 1084 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1085 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1086 zio->io_pipeline |= ZIO_STAGE_NOP_WRITE; 1087 } 1088 } 1089 1090 return (ZIO_PIPELINE_CONTINUE); 1091 } 1092 1093 static int 1094 zio_free_bp_init(zio_t *zio) 1095 { 1096 blkptr_t *bp = zio->io_bp; 1097 1098 if (zio->io_child_type == ZIO_CHILD_LOGICAL) { 1099 if (BP_GET_DEDUP(bp)) 1100 zio->io_pipeline = ZIO_DDT_FREE_PIPELINE; 1101 } 1102 1103 return (ZIO_PIPELINE_CONTINUE); 1104 } 1105 1106 /* 1107 * ========================================================================== 1108 * Execute the I/O pipeline 1109 * ========================================================================== 1110 */ 1111 1112 static void 1113 zio_taskq_dispatch(zio_t *zio, zio_taskq_type_t q, boolean_t cutinline) 1114 { 1115 spa_t *spa = zio->io_spa; 1116 zio_type_t t = zio->io_type; 1117 int flags = (cutinline ? TQ_FRONT : 0); 1118 1119 /* 1120 * If we're a config writer or a probe, the normal issue and 1121 * interrupt threads may all be blocked waiting for the config lock. 1122 * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL. 1123 */ 1124 if (zio->io_flags & (ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_PROBE)) 1125 t = ZIO_TYPE_NULL; 1126 1127 /* 1128 * A similar issue exists for the L2ARC write thread until L2ARC 2.0. 1129 */ 1130 if (t == ZIO_TYPE_WRITE && zio->io_vd && zio->io_vd->vdev_aux) 1131 t = ZIO_TYPE_NULL; 1132 1133 /* 1134 * If this is a high priority I/O, then use the high priority taskq if 1135 * available. 1136 */ 1137 if (zio->io_priority == ZIO_PRIORITY_NOW && 1138 spa->spa_zio_taskq[t][q + 1].stqs_count != 0) 1139 q++; 1140 1141 ASSERT3U(q, <, ZIO_TASKQ_TYPES); 1142 1143 /* 1144 * NB: We are assuming that the zio can only be dispatched 1145 * to a single taskq at a time. It would be a grievous error 1146 * to dispatch the zio to another taskq at the same time. 1147 */ 1148 ASSERT(zio->io_tqent.tqent_next == NULL); 1149 spa_taskq_dispatch_ent(spa, t, q, (task_func_t *)zio_execute, zio, 1150 flags, &zio->io_tqent); 1151 } 1152 1153 static boolean_t 1154 zio_taskq_member(zio_t *zio, zio_taskq_type_t q) 1155 { 1156 kthread_t *executor = zio->io_executor; 1157 spa_t *spa = zio->io_spa; 1158 1159 for (zio_type_t t = 0; t < ZIO_TYPES; t++) { 1160 spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q]; 1161 uint_t i; 1162 for (i = 0; i < tqs->stqs_count; i++) { 1163 if (taskq_member(tqs->stqs_taskq[i], executor)) 1164 return (B_TRUE); 1165 } 1166 } 1167 1168 return (B_FALSE); 1169 } 1170 1171 static int 1172 zio_issue_async(zio_t *zio) 1173 { 1174 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 1175 1176 return (ZIO_PIPELINE_STOP); 1177 } 1178 1179 void 1180 zio_interrupt(zio_t *zio) 1181 { 1182 zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE); 1183 } 1184 1185 /* 1186 * Execute the I/O pipeline until one of the following occurs: 1187 * 1188 * (1) the I/O completes 1189 * (2) the pipeline stalls waiting for dependent child I/Os 1190 * (3) the I/O issues, so we're waiting for an I/O completion interrupt 1191 * (4) the I/O is delegated by vdev-level caching or aggregation 1192 * (5) the I/O is deferred due to vdev-level queueing 1193 * (6) the I/O is handed off to another thread. 1194 * 1195 * In all cases, the pipeline stops whenever there's no CPU work; it never 1196 * burns a thread in cv_wait(). 1197 * 1198 * There's no locking on io_stage because there's no legitimate way 1199 * for multiple threads to be attempting to process the same I/O. 1200 */ 1201 static zio_pipe_stage_t *zio_pipeline[]; 1202 1203 void 1204 zio_execute(zio_t *zio) 1205 { 1206 zio->io_executor = curthread; 1207 1208 while (zio->io_stage < ZIO_STAGE_DONE) { 1209 enum zio_stage pipeline = zio->io_pipeline; 1210 enum zio_stage stage = zio->io_stage; 1211 int rv; 1212 1213 ASSERT(!MUTEX_HELD(&zio->io_lock)); 1214 ASSERT(ISP2(stage)); 1215 ASSERT(zio->io_stall == NULL); 1216 1217 do { 1218 stage <<= 1; 1219 } while ((stage & pipeline) == 0); 1220 1221 ASSERT(stage <= ZIO_STAGE_DONE); 1222 1223 /* 1224 * If we are in interrupt context and this pipeline stage 1225 * will grab a config lock that is held across I/O, 1226 * or may wait for an I/O that needs an interrupt thread 1227 * to complete, issue async to avoid deadlock. 1228 * 1229 * For VDEV_IO_START, we cut in line so that the io will 1230 * be sent to disk promptly. 1231 */ 1232 if ((stage & ZIO_BLOCKING_STAGES) && zio->io_vd == NULL && 1233 zio_taskq_member(zio, ZIO_TASKQ_INTERRUPT)) { 1234 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ? 1235 zio_requeue_io_start_cut_in_line : B_FALSE; 1236 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut); 1237 return; 1238 } 1239 1240 zio->io_stage = stage; 1241 rv = zio_pipeline[highbit(stage) - 1](zio); 1242 1243 if (rv == ZIO_PIPELINE_STOP) 1244 return; 1245 1246 ASSERT(rv == ZIO_PIPELINE_CONTINUE); 1247 } 1248 } 1249 1250 /* 1251 * ========================================================================== 1252 * Initiate I/O, either sync or async 1253 * ========================================================================== 1254 */ 1255 int 1256 zio_wait(zio_t *zio) 1257 { 1258 int error; 1259 1260 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 1261 ASSERT(zio->io_executor == NULL); 1262 1263 zio->io_waiter = curthread; 1264 1265 zio_execute(zio); 1266 1267 mutex_enter(&zio->io_lock); 1268 while (zio->io_executor != NULL) 1269 cv_wait(&zio->io_cv, &zio->io_lock); 1270 mutex_exit(&zio->io_lock); 1271 1272 error = zio->io_error; 1273 zio_destroy(zio); 1274 1275 return (error); 1276 } 1277 1278 void 1279 zio_nowait(zio_t *zio) 1280 { 1281 ASSERT(zio->io_executor == NULL); 1282 1283 if (zio->io_child_type == ZIO_CHILD_LOGICAL && 1284 zio_unique_parent(zio) == NULL) { 1285 /* 1286 * This is a logical async I/O with no parent to wait for it. 1287 * We add it to the spa_async_root_zio "Godfather" I/O which 1288 * will ensure they complete prior to unloading the pool. 1289 */ 1290 spa_t *spa = zio->io_spa; 1291 1292 zio_add_child(spa->spa_async_zio_root, zio); 1293 } 1294 1295 zio_execute(zio); 1296 } 1297 1298 /* 1299 * ========================================================================== 1300 * Reexecute or suspend/resume failed I/O 1301 * ========================================================================== 1302 */ 1303 1304 static void 1305 zio_reexecute(zio_t *pio) 1306 { 1307 zio_t *cio, *cio_next; 1308 1309 ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL); 1310 ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN); 1311 ASSERT(pio->io_gang_leader == NULL); 1312 ASSERT(pio->io_gang_tree == NULL); 1313 1314 pio->io_flags = pio->io_orig_flags; 1315 pio->io_stage = pio->io_orig_stage; 1316 pio->io_pipeline = pio->io_orig_pipeline; 1317 pio->io_reexecute = 0; 1318 pio->io_flags |= ZIO_FLAG_REEXECUTED; 1319 pio->io_error = 0; 1320 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1321 pio->io_state[w] = 0; 1322 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 1323 pio->io_child_error[c] = 0; 1324 1325 if (IO_IS_ALLOCATING(pio)) 1326 BP_ZERO(pio->io_bp); 1327 1328 /* 1329 * As we reexecute pio's children, new children could be created. 1330 * New children go to the head of pio's io_child_list, however, 1331 * so we will (correctly) not reexecute them. The key is that 1332 * the remainder of pio's io_child_list, from 'cio_next' onward, 1333 * cannot be affected by any side effects of reexecuting 'cio'. 1334 */ 1335 for (cio = zio_walk_children(pio); cio != NULL; cio = cio_next) { 1336 cio_next = zio_walk_children(pio); 1337 mutex_enter(&pio->io_lock); 1338 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1339 pio->io_children[cio->io_child_type][w]++; 1340 mutex_exit(&pio->io_lock); 1341 zio_reexecute(cio); 1342 } 1343 1344 /* 1345 * Now that all children have been reexecuted, execute the parent. 1346 * We don't reexecute "The Godfather" I/O here as it's the 1347 * responsibility of the caller to wait on him. 1348 */ 1349 if (!(pio->io_flags & ZIO_FLAG_GODFATHER)) 1350 zio_execute(pio); 1351 } 1352 1353 void 1354 zio_suspend(spa_t *spa, zio_t *zio) 1355 { 1356 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC) 1357 fm_panic("Pool '%s' has encountered an uncorrectable I/O " 1358 "failure and the failure mode property for this pool " 1359 "is set to panic.", spa_name(spa)); 1360 1361 zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL, NULL, 0, 0); 1362 1363 mutex_enter(&spa->spa_suspend_lock); 1364 1365 if (spa->spa_suspend_zio_root == NULL) 1366 spa->spa_suspend_zio_root = zio_root(spa, NULL, NULL, 1367 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | 1368 ZIO_FLAG_GODFATHER); 1369 1370 spa->spa_suspended = B_TRUE; 1371 1372 if (zio != NULL) { 1373 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 1374 ASSERT(zio != spa->spa_suspend_zio_root); 1375 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1376 ASSERT(zio_unique_parent(zio) == NULL); 1377 ASSERT(zio->io_stage == ZIO_STAGE_DONE); 1378 zio_add_child(spa->spa_suspend_zio_root, zio); 1379 } 1380 1381 mutex_exit(&spa->spa_suspend_lock); 1382 } 1383 1384 int 1385 zio_resume(spa_t *spa) 1386 { 1387 zio_t *pio; 1388 1389 /* 1390 * Reexecute all previously suspended i/o. 1391 */ 1392 mutex_enter(&spa->spa_suspend_lock); 1393 spa->spa_suspended = B_FALSE; 1394 cv_broadcast(&spa->spa_suspend_cv); 1395 pio = spa->spa_suspend_zio_root; 1396 spa->spa_suspend_zio_root = NULL; 1397 mutex_exit(&spa->spa_suspend_lock); 1398 1399 if (pio == NULL) 1400 return (0); 1401 1402 zio_reexecute(pio); 1403 return (zio_wait(pio)); 1404 } 1405 1406 void 1407 zio_resume_wait(spa_t *spa) 1408 { 1409 mutex_enter(&spa->spa_suspend_lock); 1410 while (spa_suspended(spa)) 1411 cv_wait(&spa->spa_suspend_cv, &spa->spa_suspend_lock); 1412 mutex_exit(&spa->spa_suspend_lock); 1413 } 1414 1415 /* 1416 * ========================================================================== 1417 * Gang blocks. 1418 * 1419 * A gang block is a collection of small blocks that looks to the DMU 1420 * like one large block. When zio_dva_allocate() cannot find a block 1421 * of the requested size, due to either severe fragmentation or the pool 1422 * being nearly full, it calls zio_write_gang_block() to construct the 1423 * block from smaller fragments. 1424 * 1425 * A gang block consists of a gang header (zio_gbh_phys_t) and up to 1426 * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like 1427 * an indirect block: it's an array of block pointers. It consumes 1428 * only one sector and hence is allocatable regardless of fragmentation. 1429 * The gang header's bps point to its gang members, which hold the data. 1430 * 1431 * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg> 1432 * as the verifier to ensure uniqueness of the SHA256 checksum. 1433 * Critically, the gang block bp's blk_cksum is the checksum of the data, 1434 * not the gang header. This ensures that data block signatures (needed for 1435 * deduplication) are independent of how the block is physically stored. 1436 * 1437 * Gang blocks can be nested: a gang member may itself be a gang block. 1438 * Thus every gang block is a tree in which root and all interior nodes are 1439 * gang headers, and the leaves are normal blocks that contain user data. 1440 * The root of the gang tree is called the gang leader. 1441 * 1442 * To perform any operation (read, rewrite, free, claim) on a gang block, 1443 * zio_gang_assemble() first assembles the gang tree (minus data leaves) 1444 * in the io_gang_tree field of the original logical i/o by recursively 1445 * reading the gang leader and all gang headers below it. This yields 1446 * an in-core tree containing the contents of every gang header and the 1447 * bps for every constituent of the gang block. 1448 * 1449 * With the gang tree now assembled, zio_gang_issue() just walks the gang tree 1450 * and invokes a callback on each bp. To free a gang block, zio_gang_issue() 1451 * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp. 1452 * zio_claim_gang() provides a similarly trivial wrapper for zio_claim(). 1453 * zio_read_gang() is a wrapper around zio_read() that omits reading gang 1454 * headers, since we already have those in io_gang_tree. zio_rewrite_gang() 1455 * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite() 1456 * of the gang header plus zio_checksum_compute() of the data to update the 1457 * gang header's blk_cksum as described above. 1458 * 1459 * The two-phase assemble/issue model solves the problem of partial failure -- 1460 * what if you'd freed part of a gang block but then couldn't read the 1461 * gang header for another part? Assembling the entire gang tree first 1462 * ensures that all the necessary gang header I/O has succeeded before 1463 * starting the actual work of free, claim, or write. Once the gang tree 1464 * is assembled, free and claim are in-memory operations that cannot fail. 1465 * 1466 * In the event that a gang write fails, zio_dva_unallocate() walks the 1467 * gang tree to immediately free (i.e. insert back into the space map) 1468 * everything we've allocated. This ensures that we don't get ENOSPC 1469 * errors during repeated suspend/resume cycles due to a flaky device. 1470 * 1471 * Gang rewrites only happen during sync-to-convergence. If we can't assemble 1472 * the gang tree, we won't modify the block, so we can safely defer the free 1473 * (knowing that the block is still intact). If we *can* assemble the gang 1474 * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free 1475 * each constituent bp and we can allocate a new block on the next sync pass. 1476 * 1477 * In all cases, the gang tree allows complete recovery from partial failure. 1478 * ========================================================================== 1479 */ 1480 1481 static zio_t * 1482 zio_read_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1483 { 1484 if (gn != NULL) 1485 return (pio); 1486 1487 return (zio_read(pio, pio->io_spa, bp, data, BP_GET_PSIZE(bp), 1488 NULL, NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 1489 &pio->io_bookmark)); 1490 } 1491 1492 zio_t * 1493 zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1494 { 1495 zio_t *zio; 1496 1497 if (gn != NULL) { 1498 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1499 gn->gn_gbh, SPA_GANGBLOCKSIZE, NULL, NULL, pio->io_priority, 1500 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1501 /* 1502 * As we rewrite each gang header, the pipeline will compute 1503 * a new gang block header checksum for it; but no one will 1504 * compute a new data checksum, so we do that here. The one 1505 * exception is the gang leader: the pipeline already computed 1506 * its data checksum because that stage precedes gang assembly. 1507 * (Presently, nothing actually uses interior data checksums; 1508 * this is just good hygiene.) 1509 */ 1510 if (gn != pio->io_gang_leader->io_gang_tree) { 1511 zio_checksum_compute(zio, BP_GET_CHECKSUM(bp), 1512 data, BP_GET_PSIZE(bp)); 1513 } 1514 /* 1515 * If we are here to damage data for testing purposes, 1516 * leave the GBH alone so that we can detect the damage. 1517 */ 1518 if (pio->io_gang_leader->io_flags & ZIO_FLAG_INDUCE_DAMAGE) 1519 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 1520 } else { 1521 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1522 data, BP_GET_PSIZE(bp), NULL, NULL, pio->io_priority, 1523 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1524 } 1525 1526 return (zio); 1527 } 1528 1529 /* ARGSUSED */ 1530 zio_t * 1531 zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1532 { 1533 return (zio_free_sync(pio, pio->io_spa, pio->io_txg, bp, 1534 ZIO_GANG_CHILD_FLAGS(pio))); 1535 } 1536 1537 /* ARGSUSED */ 1538 zio_t * 1539 zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1540 { 1541 return (zio_claim(pio, pio->io_spa, pio->io_txg, bp, 1542 NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio))); 1543 } 1544 1545 static zio_gang_issue_func_t *zio_gang_issue_func[ZIO_TYPES] = { 1546 NULL, 1547 zio_read_gang, 1548 zio_rewrite_gang, 1549 zio_free_gang, 1550 zio_claim_gang, 1551 NULL 1552 }; 1553 1554 static void zio_gang_tree_assemble_done(zio_t *zio); 1555 1556 static zio_gang_node_t * 1557 zio_gang_node_alloc(zio_gang_node_t **gnpp) 1558 { 1559 zio_gang_node_t *gn; 1560 1561 ASSERT(*gnpp == NULL); 1562 1563 gn = kmem_zalloc(sizeof (*gn), KM_SLEEP); 1564 gn->gn_gbh = zio_buf_alloc(SPA_GANGBLOCKSIZE); 1565 *gnpp = gn; 1566 1567 return (gn); 1568 } 1569 1570 static void 1571 zio_gang_node_free(zio_gang_node_t **gnpp) 1572 { 1573 zio_gang_node_t *gn = *gnpp; 1574 1575 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 1576 ASSERT(gn->gn_child[g] == NULL); 1577 1578 zio_buf_free(gn->gn_gbh, SPA_GANGBLOCKSIZE); 1579 kmem_free(gn, sizeof (*gn)); 1580 *gnpp = NULL; 1581 } 1582 1583 static void 1584 zio_gang_tree_free(zio_gang_node_t **gnpp) 1585 { 1586 zio_gang_node_t *gn = *gnpp; 1587 1588 if (gn == NULL) 1589 return; 1590 1591 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 1592 zio_gang_tree_free(&gn->gn_child[g]); 1593 1594 zio_gang_node_free(gnpp); 1595 } 1596 1597 static void 1598 zio_gang_tree_assemble(zio_t *gio, blkptr_t *bp, zio_gang_node_t **gnpp) 1599 { 1600 zio_gang_node_t *gn = zio_gang_node_alloc(gnpp); 1601 1602 ASSERT(gio->io_gang_leader == gio); 1603 ASSERT(BP_IS_GANG(bp)); 1604 1605 zio_nowait(zio_read(gio, gio->io_spa, bp, gn->gn_gbh, 1606 SPA_GANGBLOCKSIZE, zio_gang_tree_assemble_done, gn, 1607 gio->io_priority, ZIO_GANG_CHILD_FLAGS(gio), &gio->io_bookmark)); 1608 } 1609 1610 static void 1611 zio_gang_tree_assemble_done(zio_t *zio) 1612 { 1613 zio_t *gio = zio->io_gang_leader; 1614 zio_gang_node_t *gn = zio->io_private; 1615 blkptr_t *bp = zio->io_bp; 1616 1617 ASSERT(gio == zio_unique_parent(zio)); 1618 ASSERT(zio->io_child_count == 0); 1619 1620 if (zio->io_error) 1621 return; 1622 1623 if (BP_SHOULD_BYTESWAP(bp)) 1624 byteswap_uint64_array(zio->io_data, zio->io_size); 1625 1626 ASSERT(zio->io_data == gn->gn_gbh); 1627 ASSERT(zio->io_size == SPA_GANGBLOCKSIZE); 1628 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 1629 1630 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 1631 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 1632 if (!BP_IS_GANG(gbp)) 1633 continue; 1634 zio_gang_tree_assemble(gio, gbp, &gn->gn_child[g]); 1635 } 1636 } 1637 1638 static void 1639 zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, void *data) 1640 { 1641 zio_t *gio = pio->io_gang_leader; 1642 zio_t *zio; 1643 1644 ASSERT(BP_IS_GANG(bp) == !!gn); 1645 ASSERT(BP_GET_CHECKSUM(bp) == BP_GET_CHECKSUM(gio->io_bp)); 1646 ASSERT(BP_GET_LSIZE(bp) == BP_GET_PSIZE(bp) || gn == gio->io_gang_tree); 1647 1648 /* 1649 * If you're a gang header, your data is in gn->gn_gbh. 1650 * If you're a gang member, your data is in 'data' and gn == NULL. 1651 */ 1652 zio = zio_gang_issue_func[gio->io_type](pio, bp, gn, data); 1653 1654 if (gn != NULL) { 1655 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 1656 1657 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 1658 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 1659 if (BP_IS_HOLE(gbp)) 1660 continue; 1661 zio_gang_tree_issue(zio, gn->gn_child[g], gbp, data); 1662 data = (char *)data + BP_GET_PSIZE(gbp); 1663 } 1664 } 1665 1666 if (gn == gio->io_gang_tree) 1667 ASSERT3P((char *)gio->io_data + gio->io_size, ==, data); 1668 1669 if (zio != pio) 1670 zio_nowait(zio); 1671 } 1672 1673 static int 1674 zio_gang_assemble(zio_t *zio) 1675 { 1676 blkptr_t *bp = zio->io_bp; 1677 1678 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == NULL); 1679 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 1680 1681 zio->io_gang_leader = zio; 1682 1683 zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree); 1684 1685 return (ZIO_PIPELINE_CONTINUE); 1686 } 1687 1688 static int 1689 zio_gang_issue(zio_t *zio) 1690 { 1691 blkptr_t *bp = zio->io_bp; 1692 1693 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE)) 1694 return (ZIO_PIPELINE_STOP); 1695 1696 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio); 1697 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 1698 1699 if (zio->io_child_error[ZIO_CHILD_GANG] == 0) 1700 zio_gang_tree_issue(zio, zio->io_gang_tree, bp, zio->io_data); 1701 else 1702 zio_gang_tree_free(&zio->io_gang_tree); 1703 1704 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1705 1706 return (ZIO_PIPELINE_CONTINUE); 1707 } 1708 1709 static void 1710 zio_write_gang_member_ready(zio_t *zio) 1711 { 1712 zio_t *pio = zio_unique_parent(zio); 1713 zio_t *gio = zio->io_gang_leader; 1714 dva_t *cdva = zio->io_bp->blk_dva; 1715 dva_t *pdva = pio->io_bp->blk_dva; 1716 uint64_t asize; 1717 1718 if (BP_IS_HOLE(zio->io_bp)) 1719 return; 1720 1721 ASSERT(BP_IS_HOLE(&zio->io_bp_orig)); 1722 1723 ASSERT(zio->io_child_type == ZIO_CHILD_GANG); 1724 ASSERT3U(zio->io_prop.zp_copies, ==, gio->io_prop.zp_copies); 1725 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp)); 1726 ASSERT3U(pio->io_prop.zp_copies, <=, BP_GET_NDVAS(pio->io_bp)); 1727 ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp)); 1728 1729 mutex_enter(&pio->io_lock); 1730 for (int d = 0; d < BP_GET_NDVAS(zio->io_bp); d++) { 1731 ASSERT(DVA_GET_GANG(&pdva[d])); 1732 asize = DVA_GET_ASIZE(&pdva[d]); 1733 asize += DVA_GET_ASIZE(&cdva[d]); 1734 DVA_SET_ASIZE(&pdva[d], asize); 1735 } 1736 mutex_exit(&pio->io_lock); 1737 } 1738 1739 static int 1740 zio_write_gang_block(zio_t *pio) 1741 { 1742 spa_t *spa = pio->io_spa; 1743 blkptr_t *bp = pio->io_bp; 1744 zio_t *gio = pio->io_gang_leader; 1745 zio_t *zio; 1746 zio_gang_node_t *gn, **gnpp; 1747 zio_gbh_phys_t *gbh; 1748 uint64_t txg = pio->io_txg; 1749 uint64_t resid = pio->io_size; 1750 uint64_t lsize; 1751 int copies = gio->io_prop.zp_copies; 1752 int gbh_copies = MIN(copies + 1, spa_max_replication(spa)); 1753 zio_prop_t zp; 1754 int error; 1755 1756 error = metaslab_alloc(spa, spa_normal_class(spa), SPA_GANGBLOCKSIZE, 1757 bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp, 1758 METASLAB_HINTBP_FAVOR | METASLAB_GANG_HEADER); 1759 if (error) { 1760 pio->io_error = error; 1761 return (ZIO_PIPELINE_CONTINUE); 1762 } 1763 1764 if (pio == gio) { 1765 gnpp = &gio->io_gang_tree; 1766 } else { 1767 gnpp = pio->io_private; 1768 ASSERT(pio->io_ready == zio_write_gang_member_ready); 1769 } 1770 1771 gn = zio_gang_node_alloc(gnpp); 1772 gbh = gn->gn_gbh; 1773 bzero(gbh, SPA_GANGBLOCKSIZE); 1774 1775 /* 1776 * Create the gang header. 1777 */ 1778 zio = zio_rewrite(pio, spa, txg, bp, gbh, SPA_GANGBLOCKSIZE, NULL, NULL, 1779 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1780 1781 /* 1782 * Create and nowait the gang children. 1783 */ 1784 for (int g = 0; resid != 0; resid -= lsize, g++) { 1785 lsize = P2ROUNDUP(resid / (SPA_GBH_NBLKPTRS - g), 1786 SPA_MINBLOCKSIZE); 1787 ASSERT(lsize >= SPA_MINBLOCKSIZE && lsize <= resid); 1788 1789 zp.zp_checksum = gio->io_prop.zp_checksum; 1790 zp.zp_compress = ZIO_COMPRESS_OFF; 1791 zp.zp_type = DMU_OT_NONE; 1792 zp.zp_level = 0; 1793 zp.zp_copies = gio->io_prop.zp_copies; 1794 zp.zp_dedup = B_FALSE; 1795 zp.zp_dedup_verify = B_FALSE; 1796 zp.zp_nopwrite = B_FALSE; 1797 1798 zio_nowait(zio_write(zio, spa, txg, &gbh->zg_blkptr[g], 1799 (char *)pio->io_data + (pio->io_size - resid), lsize, &zp, 1800 zio_write_gang_member_ready, NULL, &gn->gn_child[g], 1801 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 1802 &pio->io_bookmark)); 1803 } 1804 1805 /* 1806 * Set pio's pipeline to just wait for zio to finish. 1807 */ 1808 pio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1809 1810 zio_nowait(zio); 1811 1812 return (ZIO_PIPELINE_CONTINUE); 1813 } 1814 1815 /* 1816 * The zio_nop_write stage in the pipeline determines if allocating 1817 * a new bp is necessary. By leveraging a cryptographically secure checksum, 1818 * such as SHA256, we can compare the checksums of the new data and the old 1819 * to determine if allocating a new block is required. The nopwrite 1820 * feature can handle writes in either syncing or open context (i.e. zil 1821 * writes) and as a result is mutually exclusive with dedup. 1822 */ 1823 static int 1824 zio_nop_write(zio_t *zio) 1825 { 1826 blkptr_t *bp = zio->io_bp; 1827 blkptr_t *bp_orig = &zio->io_bp_orig; 1828 zio_prop_t *zp = &zio->io_prop; 1829 1830 ASSERT(BP_GET_LEVEL(bp) == 0); 1831 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1832 ASSERT(zp->zp_nopwrite); 1833 ASSERT(!zp->zp_dedup); 1834 ASSERT(zio->io_bp_override == NULL); 1835 ASSERT(IO_IS_ALLOCATING(zio)); 1836 1837 /* 1838 * Check to see if the original bp and the new bp have matching 1839 * characteristics (i.e. same checksum, compression algorithms, etc). 1840 * If they don't then just continue with the pipeline which will 1841 * allocate a new bp. 1842 */ 1843 if (BP_IS_HOLE(bp_orig) || 1844 !zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_dedup || 1845 BP_GET_CHECKSUM(bp) != BP_GET_CHECKSUM(bp_orig) || 1846 BP_GET_COMPRESS(bp) != BP_GET_COMPRESS(bp_orig) || 1847 BP_GET_DEDUP(bp) != BP_GET_DEDUP(bp_orig) || 1848 zp->zp_copies != BP_GET_NDVAS(bp_orig)) 1849 return (ZIO_PIPELINE_CONTINUE); 1850 1851 /* 1852 * If the checksums match then reset the pipeline so that we 1853 * avoid allocating a new bp and issuing any I/O. 1854 */ 1855 if (ZIO_CHECKSUM_EQUAL(bp->blk_cksum, bp_orig->blk_cksum)) { 1856 ASSERT(zio_checksum_table[zp->zp_checksum].ci_dedup); 1857 ASSERT3U(BP_GET_PSIZE(bp), ==, BP_GET_PSIZE(bp_orig)); 1858 ASSERT3U(BP_GET_LSIZE(bp), ==, BP_GET_LSIZE(bp_orig)); 1859 ASSERT(zp->zp_compress != ZIO_COMPRESS_OFF); 1860 ASSERT(bcmp(&bp->blk_prop, &bp_orig->blk_prop, 1861 sizeof (uint64_t)) == 0); 1862 1863 *bp = *bp_orig; 1864 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1865 zio->io_flags |= ZIO_FLAG_NOPWRITE; 1866 } 1867 1868 return (ZIO_PIPELINE_CONTINUE); 1869 } 1870 1871 /* 1872 * ========================================================================== 1873 * Dedup 1874 * ========================================================================== 1875 */ 1876 static void 1877 zio_ddt_child_read_done(zio_t *zio) 1878 { 1879 blkptr_t *bp = zio->io_bp; 1880 ddt_entry_t *dde = zio->io_private; 1881 ddt_phys_t *ddp; 1882 zio_t *pio = zio_unique_parent(zio); 1883 1884 mutex_enter(&pio->io_lock); 1885 ddp = ddt_phys_select(dde, bp); 1886 if (zio->io_error == 0) 1887 ddt_phys_clear(ddp); /* this ddp doesn't need repair */ 1888 if (zio->io_error == 0 && dde->dde_repair_data == NULL) 1889 dde->dde_repair_data = zio->io_data; 1890 else 1891 zio_buf_free(zio->io_data, zio->io_size); 1892 mutex_exit(&pio->io_lock); 1893 } 1894 1895 static int 1896 zio_ddt_read_start(zio_t *zio) 1897 { 1898 blkptr_t *bp = zio->io_bp; 1899 1900 ASSERT(BP_GET_DEDUP(bp)); 1901 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 1902 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1903 1904 if (zio->io_child_error[ZIO_CHILD_DDT]) { 1905 ddt_t *ddt = ddt_select(zio->io_spa, bp); 1906 ddt_entry_t *dde = ddt_repair_start(ddt, bp); 1907 ddt_phys_t *ddp = dde->dde_phys; 1908 ddt_phys_t *ddp_self = ddt_phys_select(dde, bp); 1909 blkptr_t blk; 1910 1911 ASSERT(zio->io_vsd == NULL); 1912 zio->io_vsd = dde; 1913 1914 if (ddp_self == NULL) 1915 return (ZIO_PIPELINE_CONTINUE); 1916 1917 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { 1918 if (ddp->ddp_phys_birth == 0 || ddp == ddp_self) 1919 continue; 1920 ddt_bp_create(ddt->ddt_checksum, &dde->dde_key, ddp, 1921 &blk); 1922 zio_nowait(zio_read(zio, zio->io_spa, &blk, 1923 zio_buf_alloc(zio->io_size), zio->io_size, 1924 zio_ddt_child_read_done, dde, zio->io_priority, 1925 ZIO_DDT_CHILD_FLAGS(zio) | ZIO_FLAG_DONT_PROPAGATE, 1926 &zio->io_bookmark)); 1927 } 1928 return (ZIO_PIPELINE_CONTINUE); 1929 } 1930 1931 zio_nowait(zio_read(zio, zio->io_spa, bp, 1932 zio->io_data, zio->io_size, NULL, NULL, zio->io_priority, 1933 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark)); 1934 1935 return (ZIO_PIPELINE_CONTINUE); 1936 } 1937 1938 static int 1939 zio_ddt_read_done(zio_t *zio) 1940 { 1941 blkptr_t *bp = zio->io_bp; 1942 1943 if (zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE)) 1944 return (ZIO_PIPELINE_STOP); 1945 1946 ASSERT(BP_GET_DEDUP(bp)); 1947 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 1948 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1949 1950 if (zio->io_child_error[ZIO_CHILD_DDT]) { 1951 ddt_t *ddt = ddt_select(zio->io_spa, bp); 1952 ddt_entry_t *dde = zio->io_vsd; 1953 if (ddt == NULL) { 1954 ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE); 1955 return (ZIO_PIPELINE_CONTINUE); 1956 } 1957 if (dde == NULL) { 1958 zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1; 1959 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 1960 return (ZIO_PIPELINE_STOP); 1961 } 1962 if (dde->dde_repair_data != NULL) { 1963 bcopy(dde->dde_repair_data, zio->io_data, zio->io_size); 1964 zio->io_child_error[ZIO_CHILD_DDT] = 0; 1965 } 1966 ddt_repair_done(ddt, dde); 1967 zio->io_vsd = NULL; 1968 } 1969 1970 ASSERT(zio->io_vsd == NULL); 1971 1972 return (ZIO_PIPELINE_CONTINUE); 1973 } 1974 1975 static boolean_t 1976 zio_ddt_collision(zio_t *zio, ddt_t *ddt, ddt_entry_t *dde) 1977 { 1978 spa_t *spa = zio->io_spa; 1979 1980 /* 1981 * Note: we compare the original data, not the transformed data, 1982 * because when zio->io_bp is an override bp, we will not have 1983 * pushed the I/O transforms. That's an important optimization 1984 * because otherwise we'd compress/encrypt all dmu_sync() data twice. 1985 */ 1986 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 1987 zio_t *lio = dde->dde_lead_zio[p]; 1988 1989 if (lio != NULL) { 1990 return (lio->io_orig_size != zio->io_orig_size || 1991 bcmp(zio->io_orig_data, lio->io_orig_data, 1992 zio->io_orig_size) != 0); 1993 } 1994 } 1995 1996 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 1997 ddt_phys_t *ddp = &dde->dde_phys[p]; 1998 1999 if (ddp->ddp_phys_birth != 0) { 2000 arc_buf_t *abuf = NULL; 2001 uint32_t aflags = ARC_WAIT; 2002 blkptr_t blk = *zio->io_bp; 2003 int error; 2004 2005 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth); 2006 2007 ddt_exit(ddt); 2008 2009 error = arc_read(NULL, spa, &blk, 2010 arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ, 2011 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, 2012 &aflags, &zio->io_bookmark); 2013 2014 if (error == 0) { 2015 if (arc_buf_size(abuf) != zio->io_orig_size || 2016 bcmp(abuf->b_data, zio->io_orig_data, 2017 zio->io_orig_size) != 0) 2018 error = SET_ERROR(EEXIST); 2019 VERIFY(arc_buf_remove_ref(abuf, &abuf)); 2020 } 2021 2022 ddt_enter(ddt); 2023 return (error != 0); 2024 } 2025 } 2026 2027 return (B_FALSE); 2028 } 2029 2030 static void 2031 zio_ddt_child_write_ready(zio_t *zio) 2032 { 2033 int p = zio->io_prop.zp_copies; 2034 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 2035 ddt_entry_t *dde = zio->io_private; 2036 ddt_phys_t *ddp = &dde->dde_phys[p]; 2037 zio_t *pio; 2038 2039 if (zio->io_error) 2040 return; 2041 2042 ddt_enter(ddt); 2043 2044 ASSERT(dde->dde_lead_zio[p] == zio); 2045 2046 ddt_phys_fill(ddp, zio->io_bp); 2047 2048 while ((pio = zio_walk_parents(zio)) != NULL) 2049 ddt_bp_fill(ddp, pio->io_bp, zio->io_txg); 2050 2051 ddt_exit(ddt); 2052 } 2053 2054 static void 2055 zio_ddt_child_write_done(zio_t *zio) 2056 { 2057 int p = zio->io_prop.zp_copies; 2058 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 2059 ddt_entry_t *dde = zio->io_private; 2060 ddt_phys_t *ddp = &dde->dde_phys[p]; 2061 2062 ddt_enter(ddt); 2063 2064 ASSERT(ddp->ddp_refcnt == 0); 2065 ASSERT(dde->dde_lead_zio[p] == zio); 2066 dde->dde_lead_zio[p] = NULL; 2067 2068 if (zio->io_error == 0) { 2069 while (zio_walk_parents(zio) != NULL) 2070 ddt_phys_addref(ddp); 2071 } else { 2072 ddt_phys_clear(ddp); 2073 } 2074 2075 ddt_exit(ddt); 2076 } 2077 2078 static void 2079 zio_ddt_ditto_write_done(zio_t *zio) 2080 { 2081 int p = DDT_PHYS_DITTO; 2082 zio_prop_t *zp = &zio->io_prop; 2083 blkptr_t *bp = zio->io_bp; 2084 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2085 ddt_entry_t *dde = zio->io_private; 2086 ddt_phys_t *ddp = &dde->dde_phys[p]; 2087 ddt_key_t *ddk = &dde->dde_key; 2088 2089 ddt_enter(ddt); 2090 2091 ASSERT(ddp->ddp_refcnt == 0); 2092 ASSERT(dde->dde_lead_zio[p] == zio); 2093 dde->dde_lead_zio[p] = NULL; 2094 2095 if (zio->io_error == 0) { 2096 ASSERT(ZIO_CHECKSUM_EQUAL(bp->blk_cksum, ddk->ddk_cksum)); 2097 ASSERT(zp->zp_copies < SPA_DVAS_PER_BP); 2098 ASSERT(zp->zp_copies == BP_GET_NDVAS(bp) - BP_IS_GANG(bp)); 2099 if (ddp->ddp_phys_birth != 0) 2100 ddt_phys_free(ddt, ddk, ddp, zio->io_txg); 2101 ddt_phys_fill(ddp, bp); 2102 } 2103 2104 ddt_exit(ddt); 2105 } 2106 2107 static int 2108 zio_ddt_write(zio_t *zio) 2109 { 2110 spa_t *spa = zio->io_spa; 2111 blkptr_t *bp = zio->io_bp; 2112 uint64_t txg = zio->io_txg; 2113 zio_prop_t *zp = &zio->io_prop; 2114 int p = zp->zp_copies; 2115 int ditto_copies; 2116 zio_t *cio = NULL; 2117 zio_t *dio = NULL; 2118 ddt_t *ddt = ddt_select(spa, bp); 2119 ddt_entry_t *dde; 2120 ddt_phys_t *ddp; 2121 2122 ASSERT(BP_GET_DEDUP(bp)); 2123 ASSERT(BP_GET_CHECKSUM(bp) == zp->zp_checksum); 2124 ASSERT(BP_IS_HOLE(bp) || zio->io_bp_override); 2125 2126 ddt_enter(ddt); 2127 dde = ddt_lookup(ddt, bp, B_TRUE); 2128 ddp = &dde->dde_phys[p]; 2129 2130 if (zp->zp_dedup_verify && zio_ddt_collision(zio, ddt, dde)) { 2131 /* 2132 * If we're using a weak checksum, upgrade to a strong checksum 2133 * and try again. If we're already using a strong checksum, 2134 * we can't resolve it, so just convert to an ordinary write. 2135 * (And automatically e-mail a paper to Nature?) 2136 */ 2137 if (!zio_checksum_table[zp->zp_checksum].ci_dedup) { 2138 zp->zp_checksum = spa_dedup_checksum(spa); 2139 zio_pop_transforms(zio); 2140 zio->io_stage = ZIO_STAGE_OPEN; 2141 BP_ZERO(bp); 2142 } else { 2143 zp->zp_dedup = B_FALSE; 2144 } 2145 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2146 ddt_exit(ddt); 2147 return (ZIO_PIPELINE_CONTINUE); 2148 } 2149 2150 ditto_copies = ddt_ditto_copies_needed(ddt, dde, ddp); 2151 ASSERT(ditto_copies < SPA_DVAS_PER_BP); 2152 2153 if (ditto_copies > ddt_ditto_copies_present(dde) && 2154 dde->dde_lead_zio[DDT_PHYS_DITTO] == NULL) { 2155 zio_prop_t czp = *zp; 2156 2157 czp.zp_copies = ditto_copies; 2158 2159 /* 2160 * If we arrived here with an override bp, we won't have run 2161 * the transform stack, so we won't have the data we need to 2162 * generate a child i/o. So, toss the override bp and restart. 2163 * This is safe, because using the override bp is just an 2164 * optimization; and it's rare, so the cost doesn't matter. 2165 */ 2166 if (zio->io_bp_override) { 2167 zio_pop_transforms(zio); 2168 zio->io_stage = ZIO_STAGE_OPEN; 2169 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2170 zio->io_bp_override = NULL; 2171 BP_ZERO(bp); 2172 ddt_exit(ddt); 2173 return (ZIO_PIPELINE_CONTINUE); 2174 } 2175 2176 dio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2177 zio->io_orig_size, &czp, NULL, 2178 zio_ddt_ditto_write_done, dde, zio->io_priority, 2179 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2180 2181 zio_push_transform(dio, zio->io_data, zio->io_size, 0, NULL); 2182 dde->dde_lead_zio[DDT_PHYS_DITTO] = dio; 2183 } 2184 2185 if (ddp->ddp_phys_birth != 0 || dde->dde_lead_zio[p] != NULL) { 2186 if (ddp->ddp_phys_birth != 0) 2187 ddt_bp_fill(ddp, bp, txg); 2188 if (dde->dde_lead_zio[p] != NULL) 2189 zio_add_child(zio, dde->dde_lead_zio[p]); 2190 else 2191 ddt_phys_addref(ddp); 2192 } else if (zio->io_bp_override) { 2193 ASSERT(bp->blk_birth == txg); 2194 ASSERT(BP_EQUAL(bp, zio->io_bp_override)); 2195 ddt_phys_fill(ddp, bp); 2196 ddt_phys_addref(ddp); 2197 } else { 2198 cio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2199 zio->io_orig_size, zp, zio_ddt_child_write_ready, 2200 zio_ddt_child_write_done, dde, zio->io_priority, 2201 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2202 2203 zio_push_transform(cio, zio->io_data, zio->io_size, 0, NULL); 2204 dde->dde_lead_zio[p] = cio; 2205 } 2206 2207 ddt_exit(ddt); 2208 2209 if (cio) 2210 zio_nowait(cio); 2211 if (dio) 2212 zio_nowait(dio); 2213 2214 return (ZIO_PIPELINE_CONTINUE); 2215 } 2216 2217 ddt_entry_t *freedde; /* for debugging */ 2218 2219 static int 2220 zio_ddt_free(zio_t *zio) 2221 { 2222 spa_t *spa = zio->io_spa; 2223 blkptr_t *bp = zio->io_bp; 2224 ddt_t *ddt = ddt_select(spa, bp); 2225 ddt_entry_t *dde; 2226 ddt_phys_t *ddp; 2227 2228 ASSERT(BP_GET_DEDUP(bp)); 2229 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2230 2231 ddt_enter(ddt); 2232 freedde = dde = ddt_lookup(ddt, bp, B_TRUE); 2233 ddp = ddt_phys_select(dde, bp); 2234 ddt_phys_decref(ddp); 2235 ddt_exit(ddt); 2236 2237 return (ZIO_PIPELINE_CONTINUE); 2238 } 2239 2240 /* 2241 * ========================================================================== 2242 * Allocate and free blocks 2243 * ========================================================================== 2244 */ 2245 static int 2246 zio_dva_allocate(zio_t *zio) 2247 { 2248 spa_t *spa = zio->io_spa; 2249 metaslab_class_t *mc = spa_normal_class(spa); 2250 blkptr_t *bp = zio->io_bp; 2251 int error; 2252 int flags = 0; 2253 2254 if (zio->io_gang_leader == NULL) { 2255 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2256 zio->io_gang_leader = zio; 2257 } 2258 2259 ASSERT(BP_IS_HOLE(bp)); 2260 ASSERT0(BP_GET_NDVAS(bp)); 2261 ASSERT3U(zio->io_prop.zp_copies, >, 0); 2262 ASSERT3U(zio->io_prop.zp_copies, <=, spa_max_replication(spa)); 2263 ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp)); 2264 2265 /* 2266 * The dump device does not support gang blocks so allocation on 2267 * behalf of the dump device (i.e. ZIO_FLAG_NODATA) must avoid 2268 * the "fast" gang feature. 2269 */ 2270 flags |= (zio->io_flags & ZIO_FLAG_NODATA) ? METASLAB_GANG_AVOID : 0; 2271 flags |= (zio->io_flags & ZIO_FLAG_GANG_CHILD) ? 2272 METASLAB_GANG_CHILD : 0; 2273 error = metaslab_alloc(spa, mc, zio->io_size, bp, 2274 zio->io_prop.zp_copies, zio->io_txg, NULL, flags); 2275 2276 if (error) { 2277 spa_dbgmsg(spa, "%s: metaslab allocation failure: zio %p, " 2278 "size %llu, error %d", spa_name(spa), zio, zio->io_size, 2279 error); 2280 if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE) 2281 return (zio_write_gang_block(zio)); 2282 zio->io_error = error; 2283 } 2284 2285 return (ZIO_PIPELINE_CONTINUE); 2286 } 2287 2288 static int 2289 zio_dva_free(zio_t *zio) 2290 { 2291 metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE); 2292 2293 return (ZIO_PIPELINE_CONTINUE); 2294 } 2295 2296 static int 2297 zio_dva_claim(zio_t *zio) 2298 { 2299 int error; 2300 2301 error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg); 2302 if (error) 2303 zio->io_error = error; 2304 2305 return (ZIO_PIPELINE_CONTINUE); 2306 } 2307 2308 /* 2309 * Undo an allocation. This is used by zio_done() when an I/O fails 2310 * and we want to give back the block we just allocated. 2311 * This handles both normal blocks and gang blocks. 2312 */ 2313 static void 2314 zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp) 2315 { 2316 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp)); 2317 ASSERT(zio->io_bp_override == NULL); 2318 2319 if (!BP_IS_HOLE(bp)) 2320 metaslab_free(zio->io_spa, bp, bp->blk_birth, B_TRUE); 2321 2322 if (gn != NULL) { 2323 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 2324 zio_dva_unallocate(zio, gn->gn_child[g], 2325 &gn->gn_gbh->zg_blkptr[g]); 2326 } 2327 } 2328 } 2329 2330 /* 2331 * Try to allocate an intent log block. Return 0 on success, errno on failure. 2332 */ 2333 int 2334 zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp, blkptr_t *old_bp, 2335 uint64_t size, boolean_t use_slog) 2336 { 2337 int error = 1; 2338 2339 ASSERT(txg > spa_syncing_txg(spa)); 2340 2341 /* 2342 * ZIL blocks are always contiguous (i.e. not gang blocks) so we 2343 * set the METASLAB_GANG_AVOID flag so that they don't "fast gang" 2344 * when allocating them. 2345 */ 2346 if (use_slog) { 2347 error = metaslab_alloc(spa, spa_log_class(spa), size, 2348 new_bp, 1, txg, old_bp, 2349 METASLAB_HINTBP_AVOID | METASLAB_GANG_AVOID); 2350 } 2351 2352 if (error) { 2353 error = metaslab_alloc(spa, spa_normal_class(spa), size, 2354 new_bp, 1, txg, old_bp, 2355 METASLAB_HINTBP_AVOID | METASLAB_GANG_AVOID); 2356 } 2357 2358 if (error == 0) { 2359 BP_SET_LSIZE(new_bp, size); 2360 BP_SET_PSIZE(new_bp, size); 2361 BP_SET_COMPRESS(new_bp, ZIO_COMPRESS_OFF); 2362 BP_SET_CHECKSUM(new_bp, 2363 spa_version(spa) >= SPA_VERSION_SLIM_ZIL 2364 ? ZIO_CHECKSUM_ZILOG2 : ZIO_CHECKSUM_ZILOG); 2365 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG); 2366 BP_SET_LEVEL(new_bp, 0); 2367 BP_SET_DEDUP(new_bp, 0); 2368 BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER); 2369 } 2370 2371 return (error); 2372 } 2373 2374 /* 2375 * Free an intent log block. 2376 */ 2377 void 2378 zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp) 2379 { 2380 ASSERT(BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG); 2381 ASSERT(!BP_IS_GANG(bp)); 2382 2383 zio_free(spa, txg, bp); 2384 } 2385 2386 /* 2387 * ========================================================================== 2388 * Read and write to physical devices 2389 * ========================================================================== 2390 */ 2391 static int 2392 zio_vdev_io_start(zio_t *zio) 2393 { 2394 vdev_t *vd = zio->io_vd; 2395 uint64_t align; 2396 spa_t *spa = zio->io_spa; 2397 2398 ASSERT(zio->io_error == 0); 2399 ASSERT(zio->io_child_error[ZIO_CHILD_VDEV] == 0); 2400 2401 if (vd == NULL) { 2402 if (!(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 2403 spa_config_enter(spa, SCL_ZIO, zio, RW_READER); 2404 2405 /* 2406 * The mirror_ops handle multiple DVAs in a single BP. 2407 */ 2408 return (vdev_mirror_ops.vdev_op_io_start(zio)); 2409 } 2410 2411 /* 2412 * We keep track of time-sensitive I/Os so that the scan thread 2413 * can quickly react to certain workloads. In particular, we care 2414 * about non-scrubbing, top-level reads and writes with the following 2415 * characteristics: 2416 * - synchronous writes of user data to non-slog devices 2417 * - any reads of user data 2418 * When these conditions are met, adjust the timestamp of spa_last_io 2419 * which allows the scan thread to adjust its workload accordingly. 2420 */ 2421 if (!(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && zio->io_bp != NULL && 2422 vd == vd->vdev_top && !vd->vdev_islog && 2423 zio->io_bookmark.zb_objset != DMU_META_OBJSET && 2424 zio->io_txg != spa_syncing_txg(spa)) { 2425 uint64_t old = spa->spa_last_io; 2426 uint64_t new = ddi_get_lbolt64(); 2427 if (old != new) 2428 (void) atomic_cas_64(&spa->spa_last_io, old, new); 2429 } 2430 2431 align = 1ULL << vd->vdev_top->vdev_ashift; 2432 2433 if (P2PHASE(zio->io_size, align) != 0) { 2434 uint64_t asize = P2ROUNDUP(zio->io_size, align); 2435 char *abuf = zio_buf_alloc(asize); 2436 ASSERT(vd == vd->vdev_top); 2437 if (zio->io_type == ZIO_TYPE_WRITE) { 2438 bcopy(zio->io_data, abuf, zio->io_size); 2439 bzero(abuf + zio->io_size, asize - zio->io_size); 2440 } 2441 zio_push_transform(zio, abuf, asize, asize, zio_subblock); 2442 } 2443 2444 ASSERT(P2PHASE(zio->io_offset, align) == 0); 2445 ASSERT(P2PHASE(zio->io_size, align) == 0); 2446 VERIFY(zio->io_type != ZIO_TYPE_WRITE || spa_writeable(spa)); 2447 2448 /* 2449 * If this is a repair I/O, and there's no self-healing involved -- 2450 * that is, we're just resilvering what we expect to resilver -- 2451 * then don't do the I/O unless zio's txg is actually in vd's DTL. 2452 * This prevents spurious resilvering with nested replication. 2453 * For example, given a mirror of mirrors, (A+B)+(C+D), if only 2454 * A is out of date, we'll read from C+D, then use the data to 2455 * resilver A+B -- but we don't actually want to resilver B, just A. 2456 * The top-level mirror has no way to know this, so instead we just 2457 * discard unnecessary repairs as we work our way down the vdev tree. 2458 * The same logic applies to any form of nested replication: 2459 * ditto + mirror, RAID-Z + replacing, etc. This covers them all. 2460 */ 2461 if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) && 2462 !(zio->io_flags & ZIO_FLAG_SELF_HEAL) && 2463 zio->io_txg != 0 && /* not a delegated i/o */ 2464 !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) { 2465 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 2466 zio_vdev_io_bypass(zio); 2467 return (ZIO_PIPELINE_CONTINUE); 2468 } 2469 2470 if (vd->vdev_ops->vdev_op_leaf && 2471 (zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE)) { 2472 2473 if (zio->io_type == ZIO_TYPE_READ && vdev_cache_read(zio) == 0) 2474 return (ZIO_PIPELINE_CONTINUE); 2475 2476 if ((zio = vdev_queue_io(zio)) == NULL) 2477 return (ZIO_PIPELINE_STOP); 2478 2479 if (!vdev_accessible(vd, zio)) { 2480 zio->io_error = SET_ERROR(ENXIO); 2481 zio_interrupt(zio); 2482 return (ZIO_PIPELINE_STOP); 2483 } 2484 } 2485 2486 return (vd->vdev_ops->vdev_op_io_start(zio)); 2487 } 2488 2489 static int 2490 zio_vdev_io_done(zio_t *zio) 2491 { 2492 vdev_t *vd = zio->io_vd; 2493 vdev_ops_t *ops = vd ? vd->vdev_ops : &vdev_mirror_ops; 2494 boolean_t unexpected_error = B_FALSE; 2495 2496 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 2497 return (ZIO_PIPELINE_STOP); 2498 2499 ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE); 2500 2501 if (vd != NULL && vd->vdev_ops->vdev_op_leaf) { 2502 2503 vdev_queue_io_done(zio); 2504 2505 if (zio->io_type == ZIO_TYPE_WRITE) 2506 vdev_cache_write(zio); 2507 2508 if (zio_injection_enabled && zio->io_error == 0) 2509 zio->io_error = zio_handle_device_injection(vd, 2510 zio, EIO); 2511 2512 if (zio_injection_enabled && zio->io_error == 0) 2513 zio->io_error = zio_handle_label_injection(zio, EIO); 2514 2515 if (zio->io_error) { 2516 if (!vdev_accessible(vd, zio)) { 2517 zio->io_error = SET_ERROR(ENXIO); 2518 } else { 2519 unexpected_error = B_TRUE; 2520 } 2521 } 2522 } 2523 2524 ops->vdev_op_io_done(zio); 2525 2526 if (unexpected_error) 2527 VERIFY(vdev_probe(vd, zio) == NULL); 2528 2529 return (ZIO_PIPELINE_CONTINUE); 2530 } 2531 2532 /* 2533 * For non-raidz ZIOs, we can just copy aside the bad data read from the 2534 * disk, and use that to finish the checksum ereport later. 2535 */ 2536 static void 2537 zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr, 2538 const void *good_buf) 2539 { 2540 /* no processing needed */ 2541 zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE); 2542 } 2543 2544 /*ARGSUSED*/ 2545 void 2546 zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *ignored) 2547 { 2548 void *buf = zio_buf_alloc(zio->io_size); 2549 2550 bcopy(zio->io_data, buf, zio->io_size); 2551 2552 zcr->zcr_cbinfo = zio->io_size; 2553 zcr->zcr_cbdata = buf; 2554 zcr->zcr_finish = zio_vsd_default_cksum_finish; 2555 zcr->zcr_free = zio_buf_free; 2556 } 2557 2558 static int 2559 zio_vdev_io_assess(zio_t *zio) 2560 { 2561 vdev_t *vd = zio->io_vd; 2562 2563 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 2564 return (ZIO_PIPELINE_STOP); 2565 2566 if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 2567 spa_config_exit(zio->io_spa, SCL_ZIO, zio); 2568 2569 if (zio->io_vsd != NULL) { 2570 zio->io_vsd_ops->vsd_free(zio); 2571 zio->io_vsd = NULL; 2572 } 2573 2574 if (zio_injection_enabled && zio->io_error == 0) 2575 zio->io_error = zio_handle_fault_injection(zio, EIO); 2576 2577 /* 2578 * If the I/O failed, determine whether we should attempt to retry it. 2579 * 2580 * On retry, we cut in line in the issue queue, since we don't want 2581 * compression/checksumming/etc. work to prevent our (cheap) IO reissue. 2582 */ 2583 if (zio->io_error && vd == NULL && 2584 !(zio->io_flags & (ZIO_FLAG_DONT_RETRY | ZIO_FLAG_IO_RETRY))) { 2585 ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_QUEUE)); /* not a leaf */ 2586 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_BYPASS)); /* not a leaf */ 2587 zio->io_error = 0; 2588 zio->io_flags |= ZIO_FLAG_IO_RETRY | 2589 ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE; 2590 zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1; 2591 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, 2592 zio_requeue_io_start_cut_in_line); 2593 return (ZIO_PIPELINE_STOP); 2594 } 2595 2596 /* 2597 * If we got an error on a leaf device, convert it to ENXIO 2598 * if the device is not accessible at all. 2599 */ 2600 if (zio->io_error && vd != NULL && vd->vdev_ops->vdev_op_leaf && 2601 !vdev_accessible(vd, zio)) 2602 zio->io_error = SET_ERROR(ENXIO); 2603 2604 /* 2605 * If we can't write to an interior vdev (mirror or RAID-Z), 2606 * set vdev_cant_write so that we stop trying to allocate from it. 2607 */ 2608 if (zio->io_error == ENXIO && zio->io_type == ZIO_TYPE_WRITE && 2609 vd != NULL && !vd->vdev_ops->vdev_op_leaf) { 2610 vd->vdev_cant_write = B_TRUE; 2611 } 2612 2613 if (zio->io_error) 2614 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2615 2616 return (ZIO_PIPELINE_CONTINUE); 2617 } 2618 2619 void 2620 zio_vdev_io_reissue(zio_t *zio) 2621 { 2622 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 2623 ASSERT(zio->io_error == 0); 2624 2625 zio->io_stage >>= 1; 2626 } 2627 2628 void 2629 zio_vdev_io_redone(zio_t *zio) 2630 { 2631 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE); 2632 2633 zio->io_stage >>= 1; 2634 } 2635 2636 void 2637 zio_vdev_io_bypass(zio_t *zio) 2638 { 2639 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 2640 ASSERT(zio->io_error == 0); 2641 2642 zio->io_flags |= ZIO_FLAG_IO_BYPASS; 2643 zio->io_stage = ZIO_STAGE_VDEV_IO_ASSESS >> 1; 2644 } 2645 2646 /* 2647 * ========================================================================== 2648 * Generate and verify checksums 2649 * ========================================================================== 2650 */ 2651 static int 2652 zio_checksum_generate(zio_t *zio) 2653 { 2654 blkptr_t *bp = zio->io_bp; 2655 enum zio_checksum checksum; 2656 2657 if (bp == NULL) { 2658 /* 2659 * This is zio_write_phys(). 2660 * We're either generating a label checksum, or none at all. 2661 */ 2662 checksum = zio->io_prop.zp_checksum; 2663 2664 if (checksum == ZIO_CHECKSUM_OFF) 2665 return (ZIO_PIPELINE_CONTINUE); 2666 2667 ASSERT(checksum == ZIO_CHECKSUM_LABEL); 2668 } else { 2669 if (BP_IS_GANG(bp) && zio->io_child_type == ZIO_CHILD_GANG) { 2670 ASSERT(!IO_IS_ALLOCATING(zio)); 2671 checksum = ZIO_CHECKSUM_GANG_HEADER; 2672 } else { 2673 checksum = BP_GET_CHECKSUM(bp); 2674 } 2675 } 2676 2677 zio_checksum_compute(zio, checksum, zio->io_data, zio->io_size); 2678 2679 return (ZIO_PIPELINE_CONTINUE); 2680 } 2681 2682 static int 2683 zio_checksum_verify(zio_t *zio) 2684 { 2685 zio_bad_cksum_t info; 2686 blkptr_t *bp = zio->io_bp; 2687 int error; 2688 2689 ASSERT(zio->io_vd != NULL); 2690 2691 if (bp == NULL) { 2692 /* 2693 * This is zio_read_phys(). 2694 * We're either verifying a label checksum, or nothing at all. 2695 */ 2696 if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF) 2697 return (ZIO_PIPELINE_CONTINUE); 2698 2699 ASSERT(zio->io_prop.zp_checksum == ZIO_CHECKSUM_LABEL); 2700 } 2701 2702 if ((error = zio_checksum_error(zio, &info)) != 0) { 2703 zio->io_error = error; 2704 if (!(zio->io_flags & ZIO_FLAG_SPECULATIVE)) { 2705 zfs_ereport_start_checksum(zio->io_spa, 2706 zio->io_vd, zio, zio->io_offset, 2707 zio->io_size, NULL, &info); 2708 } 2709 } 2710 2711 return (ZIO_PIPELINE_CONTINUE); 2712 } 2713 2714 /* 2715 * Called by RAID-Z to ensure we don't compute the checksum twice. 2716 */ 2717 void 2718 zio_checksum_verified(zio_t *zio) 2719 { 2720 zio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 2721 } 2722 2723 /* 2724 * ========================================================================== 2725 * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other. 2726 * An error of 0 indictes success. ENXIO indicates whole-device failure, 2727 * which may be transient (e.g. unplugged) or permament. ECKSUM and EIO 2728 * indicate errors that are specific to one I/O, and most likely permanent. 2729 * Any other error is presumed to be worse because we weren't expecting it. 2730 * ========================================================================== 2731 */ 2732 int 2733 zio_worst_error(int e1, int e2) 2734 { 2735 static int zio_error_rank[] = { 0, ENXIO, ECKSUM, EIO }; 2736 int r1, r2; 2737 2738 for (r1 = 0; r1 < sizeof (zio_error_rank) / sizeof (int); r1++) 2739 if (e1 == zio_error_rank[r1]) 2740 break; 2741 2742 for (r2 = 0; r2 < sizeof (zio_error_rank) / sizeof (int); r2++) 2743 if (e2 == zio_error_rank[r2]) 2744 break; 2745 2746 return (r1 > r2 ? e1 : e2); 2747 } 2748 2749 /* 2750 * ========================================================================== 2751 * I/O completion 2752 * ========================================================================== 2753 */ 2754 static int 2755 zio_ready(zio_t *zio) 2756 { 2757 blkptr_t *bp = zio->io_bp; 2758 zio_t *pio, *pio_next; 2759 2760 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 2761 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_READY)) 2762 return (ZIO_PIPELINE_STOP); 2763 2764 if (zio->io_ready) { 2765 ASSERT(IO_IS_ALLOCATING(zio)); 2766 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp) || 2767 (zio->io_flags & ZIO_FLAG_NOPWRITE)); 2768 ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0); 2769 2770 zio->io_ready(zio); 2771 } 2772 2773 if (bp != NULL && bp != &zio->io_bp_copy) 2774 zio->io_bp_copy = *bp; 2775 2776 if (zio->io_error) 2777 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2778 2779 mutex_enter(&zio->io_lock); 2780 zio->io_state[ZIO_WAIT_READY] = 1; 2781 pio = zio_walk_parents(zio); 2782 mutex_exit(&zio->io_lock); 2783 2784 /* 2785 * As we notify zio's parents, new parents could be added. 2786 * New parents go to the head of zio's io_parent_list, however, 2787 * so we will (correctly) not notify them. The remainder of zio's 2788 * io_parent_list, from 'pio_next' onward, cannot change because 2789 * all parents must wait for us to be done before they can be done. 2790 */ 2791 for (; pio != NULL; pio = pio_next) { 2792 pio_next = zio_walk_parents(zio); 2793 zio_notify_parent(pio, zio, ZIO_WAIT_READY); 2794 } 2795 2796 if (zio->io_flags & ZIO_FLAG_NODATA) { 2797 if (BP_IS_GANG(bp)) { 2798 zio->io_flags &= ~ZIO_FLAG_NODATA; 2799 } else { 2800 ASSERT((uintptr_t)zio->io_data < SPA_MAXBLOCKSIZE); 2801 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 2802 } 2803 } 2804 2805 if (zio_injection_enabled && 2806 zio->io_spa->spa_syncing_txg == zio->io_txg) 2807 zio_handle_ignored_writes(zio); 2808 2809 return (ZIO_PIPELINE_CONTINUE); 2810 } 2811 2812 static int 2813 zio_done(zio_t *zio) 2814 { 2815 spa_t *spa = zio->io_spa; 2816 zio_t *lio = zio->io_logical; 2817 blkptr_t *bp = zio->io_bp; 2818 vdev_t *vd = zio->io_vd; 2819 uint64_t psize = zio->io_size; 2820 zio_t *pio, *pio_next; 2821 2822 /* 2823 * If our children haven't all completed, 2824 * wait for them and then repeat this pipeline stage. 2825 */ 2826 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE) || 2827 zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE) || 2828 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE) || 2829 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_DONE)) 2830 return (ZIO_PIPELINE_STOP); 2831 2832 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 2833 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 2834 ASSERT(zio->io_children[c][w] == 0); 2835 2836 if (bp != NULL) { 2837 ASSERT(bp->blk_pad[0] == 0); 2838 ASSERT(bp->blk_pad[1] == 0); 2839 ASSERT(bcmp(bp, &zio->io_bp_copy, sizeof (blkptr_t)) == 0 || 2840 (bp == zio_unique_parent(zio)->io_bp)); 2841 if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(bp) && 2842 zio->io_bp_override == NULL && 2843 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) { 2844 ASSERT(!BP_SHOULD_BYTESWAP(bp)); 2845 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(bp)); 2846 ASSERT(BP_COUNT_GANG(bp) == 0 || 2847 (BP_COUNT_GANG(bp) == BP_GET_NDVAS(bp))); 2848 } 2849 if (zio->io_flags & ZIO_FLAG_NOPWRITE) 2850 VERIFY(BP_EQUAL(bp, &zio->io_bp_orig)); 2851 } 2852 2853 /* 2854 * If there were child vdev/gang/ddt errors, they apply to us now. 2855 */ 2856 zio_inherit_child_errors(zio, ZIO_CHILD_VDEV); 2857 zio_inherit_child_errors(zio, ZIO_CHILD_GANG); 2858 zio_inherit_child_errors(zio, ZIO_CHILD_DDT); 2859 2860 /* 2861 * If the I/O on the transformed data was successful, generate any 2862 * checksum reports now while we still have the transformed data. 2863 */ 2864 if (zio->io_error == 0) { 2865 while (zio->io_cksum_report != NULL) { 2866 zio_cksum_report_t *zcr = zio->io_cksum_report; 2867 uint64_t align = zcr->zcr_align; 2868 uint64_t asize = P2ROUNDUP(psize, align); 2869 char *abuf = zio->io_data; 2870 2871 if (asize != psize) { 2872 abuf = zio_buf_alloc(asize); 2873 bcopy(zio->io_data, abuf, psize); 2874 bzero(abuf + psize, asize - psize); 2875 } 2876 2877 zio->io_cksum_report = zcr->zcr_next; 2878 zcr->zcr_next = NULL; 2879 zcr->zcr_finish(zcr, abuf); 2880 zfs_ereport_free_checksum(zcr); 2881 2882 if (asize != psize) 2883 zio_buf_free(abuf, asize); 2884 } 2885 } 2886 2887 zio_pop_transforms(zio); /* note: may set zio->io_error */ 2888 2889 vdev_stat_update(zio, psize); 2890 2891 if (zio->io_error) { 2892 /* 2893 * If this I/O is attached to a particular vdev, 2894 * generate an error message describing the I/O failure 2895 * at the block level. We ignore these errors if the 2896 * device is currently unavailable. 2897 */ 2898 if (zio->io_error != ECKSUM && vd != NULL && !vdev_is_dead(vd)) 2899 zfs_ereport_post(FM_EREPORT_ZFS_IO, spa, vd, zio, 0, 0); 2900 2901 if ((zio->io_error == EIO || !(zio->io_flags & 2902 (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) && 2903 zio == lio) { 2904 /* 2905 * For logical I/O requests, tell the SPA to log the 2906 * error and generate a logical data ereport. 2907 */ 2908 spa_log_error(spa, zio); 2909 zfs_ereport_post(FM_EREPORT_ZFS_DATA, spa, NULL, zio, 2910 0, 0); 2911 } 2912 } 2913 2914 if (zio->io_error && zio == lio) { 2915 /* 2916 * Determine whether zio should be reexecuted. This will 2917 * propagate all the way to the root via zio_notify_parent(). 2918 */ 2919 ASSERT(vd == NULL && bp != NULL); 2920 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2921 2922 if (IO_IS_ALLOCATING(zio) && 2923 !(zio->io_flags & ZIO_FLAG_CANFAIL)) { 2924 if (zio->io_error != ENOSPC) 2925 zio->io_reexecute |= ZIO_REEXECUTE_NOW; 2926 else 2927 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 2928 } 2929 2930 if ((zio->io_type == ZIO_TYPE_READ || 2931 zio->io_type == ZIO_TYPE_FREE) && 2932 !(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && 2933 zio->io_error == ENXIO && 2934 spa_load_state(spa) == SPA_LOAD_NONE && 2935 spa_get_failmode(spa) != ZIO_FAILURE_MODE_CONTINUE) 2936 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 2937 2938 if (!(zio->io_flags & ZIO_FLAG_CANFAIL) && !zio->io_reexecute) 2939 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 2940 2941 /* 2942 * Here is a possibly good place to attempt to do 2943 * either combinatorial reconstruction or error correction 2944 * based on checksums. It also might be a good place 2945 * to send out preliminary ereports before we suspend 2946 * processing. 2947 */ 2948 } 2949 2950 /* 2951 * If there were logical child errors, they apply to us now. 2952 * We defer this until now to avoid conflating logical child 2953 * errors with errors that happened to the zio itself when 2954 * updating vdev stats and reporting FMA events above. 2955 */ 2956 zio_inherit_child_errors(zio, ZIO_CHILD_LOGICAL); 2957 2958 if ((zio->io_error || zio->io_reexecute) && 2959 IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio && 2960 !(zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE))) 2961 zio_dva_unallocate(zio, zio->io_gang_tree, bp); 2962 2963 zio_gang_tree_free(&zio->io_gang_tree); 2964 2965 /* 2966 * Godfather I/Os should never suspend. 2967 */ 2968 if ((zio->io_flags & ZIO_FLAG_GODFATHER) && 2969 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) 2970 zio->io_reexecute = 0; 2971 2972 if (zio->io_reexecute) { 2973 /* 2974 * This is a logical I/O that wants to reexecute. 2975 * 2976 * Reexecute is top-down. When an i/o fails, if it's not 2977 * the root, it simply notifies its parent and sticks around. 2978 * The parent, seeing that it still has children in zio_done(), 2979 * does the same. This percolates all the way up to the root. 2980 * The root i/o will reexecute or suspend the entire tree. 2981 * 2982 * This approach ensures that zio_reexecute() honors 2983 * all the original i/o dependency relationships, e.g. 2984 * parents not executing until children are ready. 2985 */ 2986 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2987 2988 zio->io_gang_leader = NULL; 2989 2990 mutex_enter(&zio->io_lock); 2991 zio->io_state[ZIO_WAIT_DONE] = 1; 2992 mutex_exit(&zio->io_lock); 2993 2994 /* 2995 * "The Godfather" I/O monitors its children but is 2996 * not a true parent to them. It will track them through 2997 * the pipeline but severs its ties whenever they get into 2998 * trouble (e.g. suspended). This allows "The Godfather" 2999 * I/O to return status without blocking. 3000 */ 3001 for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) { 3002 zio_link_t *zl = zio->io_walk_link; 3003 pio_next = zio_walk_parents(zio); 3004 3005 if ((pio->io_flags & ZIO_FLAG_GODFATHER) && 3006 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) { 3007 zio_remove_child(pio, zio, zl); 3008 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3009 } 3010 } 3011 3012 if ((pio = zio_unique_parent(zio)) != NULL) { 3013 /* 3014 * We're not a root i/o, so there's nothing to do 3015 * but notify our parent. Don't propagate errors 3016 * upward since we haven't permanently failed yet. 3017 */ 3018 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 3019 zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE; 3020 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3021 } else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) { 3022 /* 3023 * We'd fail again if we reexecuted now, so suspend 3024 * until conditions improve (e.g. device comes online). 3025 */ 3026 zio_suspend(spa, zio); 3027 } else { 3028 /* 3029 * Reexecution is potentially a huge amount of work. 3030 * Hand it off to the otherwise-unused claim taskq. 3031 */ 3032 ASSERT(zio->io_tqent.tqent_next == NULL); 3033 spa_taskq_dispatch_ent(spa, ZIO_TYPE_CLAIM, 3034 ZIO_TASKQ_ISSUE, (task_func_t *)zio_reexecute, zio, 3035 0, &zio->io_tqent); 3036 } 3037 return (ZIO_PIPELINE_STOP); 3038 } 3039 3040 ASSERT(zio->io_child_count == 0); 3041 ASSERT(zio->io_reexecute == 0); 3042 ASSERT(zio->io_error == 0 || (zio->io_flags & ZIO_FLAG_CANFAIL)); 3043 3044 /* 3045 * Report any checksum errors, since the I/O is complete. 3046 */ 3047 while (zio->io_cksum_report != NULL) { 3048 zio_cksum_report_t *zcr = zio->io_cksum_report; 3049 zio->io_cksum_report = zcr->zcr_next; 3050 zcr->zcr_next = NULL; 3051 zcr->zcr_finish(zcr, NULL); 3052 zfs_ereport_free_checksum(zcr); 3053 } 3054 3055 /* 3056 * It is the responsibility of the done callback to ensure that this 3057 * particular zio is no longer discoverable for adoption, and as 3058 * such, cannot acquire any new parents. 3059 */ 3060 if (zio->io_done) 3061 zio->io_done(zio); 3062 3063 mutex_enter(&zio->io_lock); 3064 zio->io_state[ZIO_WAIT_DONE] = 1; 3065 mutex_exit(&zio->io_lock); 3066 3067 for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) { 3068 zio_link_t *zl = zio->io_walk_link; 3069 pio_next = zio_walk_parents(zio); 3070 zio_remove_child(pio, zio, zl); 3071 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3072 } 3073 3074 if (zio->io_waiter != NULL) { 3075 mutex_enter(&zio->io_lock); 3076 zio->io_executor = NULL; 3077 cv_broadcast(&zio->io_cv); 3078 mutex_exit(&zio->io_lock); 3079 } else { 3080 zio_destroy(zio); 3081 } 3082 3083 return (ZIO_PIPELINE_STOP); 3084 } 3085 3086 /* 3087 * ========================================================================== 3088 * I/O pipeline definition 3089 * ========================================================================== 3090 */ 3091 static zio_pipe_stage_t *zio_pipeline[] = { 3092 NULL, 3093 zio_read_bp_init, 3094 zio_free_bp_init, 3095 zio_issue_async, 3096 zio_write_bp_init, 3097 zio_checksum_generate, 3098 zio_nop_write, 3099 zio_ddt_read_start, 3100 zio_ddt_read_done, 3101 zio_ddt_write, 3102 zio_ddt_free, 3103 zio_gang_assemble, 3104 zio_gang_issue, 3105 zio_dva_allocate, 3106 zio_dva_free, 3107 zio_dva_claim, 3108 zio_ready, 3109 zio_vdev_io_start, 3110 zio_vdev_io_done, 3111 zio_vdev_io_assess, 3112 zio_checksum_verify, 3113 zio_done 3114 }; 3115 3116 /* dnp is the dnode for zb1->zb_object */ 3117 boolean_t 3118 zbookmark_is_before(const dnode_phys_t *dnp, const zbookmark_t *zb1, 3119 const zbookmark_t *zb2) 3120 { 3121 uint64_t zb1nextL0, zb2thisobj; 3122 3123 ASSERT(zb1->zb_objset == zb2->zb_objset); 3124 ASSERT(zb2->zb_level == 0); 3125 3126 /* 3127 * A bookmark in the deadlist is considered to be after 3128 * everything else. 3129 */ 3130 if (zb2->zb_object == DMU_DEADLIST_OBJECT) 3131 return (B_TRUE); 3132 3133 /* The objset_phys_t isn't before anything. */ 3134 if (dnp == NULL) 3135 return (B_FALSE); 3136 3137 zb1nextL0 = (zb1->zb_blkid + 1) << 3138 ((zb1->zb_level) * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT)); 3139 3140 zb2thisobj = zb2->zb_object ? zb2->zb_object : 3141 zb2->zb_blkid << (DNODE_BLOCK_SHIFT - DNODE_SHIFT); 3142 3143 if (zb1->zb_object == DMU_META_DNODE_OBJECT) { 3144 uint64_t nextobj = zb1nextL0 * 3145 (dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT) >> DNODE_SHIFT; 3146 return (nextobj <= zb2thisobj); 3147 } 3148 3149 if (zb1->zb_object < zb2thisobj) 3150 return (B_TRUE); 3151 if (zb1->zb_object > zb2thisobj) 3152 return (B_FALSE); 3153 if (zb2->zb_object == DMU_META_DNODE_OBJECT) 3154 return (B_FALSE); 3155 return (zb1nextL0 <= zb2->zb_blkid); 3156 }