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