1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2011, 2014 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 #include <sys/blkptr.h> 40 #include <sys/zfeature.h> 41 42 /* 43 * ========================================================================== 44 * I/O type descriptions 45 * ========================================================================== 46 */ 47 const char *zio_type_name[ZIO_TYPES] = { 48 "zio_null", "zio_read", "zio_write", "zio_free", "zio_claim", 49 "zio_ioctl" 50 }; 51 52 /* 53 * ========================================================================== 54 * I/O kmem caches 55 * ========================================================================== 56 */ 57 kmem_cache_t *zio_cache; 58 kmem_cache_t *zio_link_cache; 59 kmem_cache_t *zio_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; 60 kmem_cache_t *zio_data_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; 61 62 #ifdef _KERNEL 63 extern vmem_t *zio_alloc_arena; 64 #endif 65 66 /* 67 * The following actions directly effect the spa's sync-to-convergence logic. 68 * The values below define the sync pass when we start performing the action. 69 * Care should be taken when changing these values as they directly impact 70 * spa_sync() performance. Tuning these values may introduce subtle performance 71 * pathologies and should only be done in the context of performance analysis. 72 * These tunables will eventually be removed and replaced with #defines once 73 * enough analysis has been done to determine optimal values. 74 * 75 * The 'zfs_sync_pass_deferred_free' pass must be greater than 1 to ensure that 76 * regular blocks are not deferred. 77 */ 78 int zfs_sync_pass_deferred_free = 2; /* defer frees starting in this pass */ 79 int zfs_sync_pass_dont_compress = 5; /* don't compress starting in this pass */ 80 int zfs_sync_pass_rewrite = 2; /* rewrite new bps starting in this pass */ 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 size_t cflags = (size > zio_buf_debug_limit) ? KMC_NODEBUG : 0; 121 122 while (p2 & (p2 - 1)) 123 p2 &= p2 - 1; 124 125 #ifndef _KERNEL 126 /* 127 * If we are using watchpoints, put each buffer on its own page, 128 * to eliminate the performance overhead of trapping to the 129 * kernel when modifying a non-watched buffer that shares the 130 * page with a watched buffer. 131 */ 132 if (arc_watch && !IS_P2ALIGNED(size, PAGESIZE)) 133 continue; 134 #endif 135 if (size <= 4 * SPA_MINBLOCKSIZE) { 136 align = SPA_MINBLOCKSIZE; 137 } else if (IS_P2ALIGNED(size, PAGESIZE)) { 138 align = PAGESIZE; 139 } else if (IS_P2ALIGNED(size, p2 >> 2)) { 140 align = p2 >> 2; 141 } 142 143 if (align != 0) { 144 char name[36]; 145 (void) sprintf(name, "zio_buf_%lu", (ulong_t)size); 146 zio_buf_cache[c] = kmem_cache_create(name, size, 147 align, NULL, NULL, NULL, NULL, NULL, cflags); 148 149 /* 150 * Since zio_data bufs do not appear in crash dumps, we 151 * pass KMC_NOTOUCH so that no allocator metadata is 152 * stored with the buffers. 153 */ 154 (void) sprintf(name, "zio_data_buf_%lu", (ulong_t)size); 155 zio_data_buf_cache[c] = kmem_cache_create(name, size, 156 align, NULL, NULL, NULL, NULL, data_alloc_arena, 157 cflags | KMC_NOTOUCH); 158 } 159 } 160 161 while (--c != 0) { 162 ASSERT(zio_buf_cache[c] != NULL); 163 if (zio_buf_cache[c - 1] == NULL) 164 zio_buf_cache[c - 1] = zio_buf_cache[c]; 165 166 ASSERT(zio_data_buf_cache[c] != NULL); 167 if (zio_data_buf_cache[c - 1] == NULL) 168 zio_data_buf_cache[c - 1] = zio_data_buf_cache[c]; 169 } 170 171 zio_inject_init(); 172 } 173 174 void 175 zio_fini(void) 176 { 177 size_t c; 178 kmem_cache_t *last_cache = NULL; 179 kmem_cache_t *last_data_cache = NULL; 180 181 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { 182 if (zio_buf_cache[c] != last_cache) { 183 last_cache = zio_buf_cache[c]; 184 kmem_cache_destroy(zio_buf_cache[c]); 185 } 186 zio_buf_cache[c] = NULL; 187 188 if (zio_data_buf_cache[c] != last_data_cache) { 189 last_data_cache = zio_data_buf_cache[c]; 190 kmem_cache_destroy(zio_data_buf_cache[c]); 191 } 192 zio_data_buf_cache[c] = NULL; 193 } 194 195 kmem_cache_destroy(zio_link_cache); 196 kmem_cache_destroy(zio_cache); 197 198 zio_inject_fini(); 199 } 200 201 /* 202 * ========================================================================== 203 * Allocate and free I/O buffers 204 * ========================================================================== 205 */ 206 207 /* 208 * Use zio_buf_alloc to allocate ZFS metadata. This data will appear in a 209 * crashdump if the kernel panics, so use it judiciously. Obviously, it's 210 * useful to inspect ZFS metadata, but if possible, we should avoid keeping 211 * excess / transient data in-core during a crashdump. 212 */ 213 void * 214 zio_buf_alloc(size_t size) 215 { 216 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 217 218 ASSERT3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 219 220 return (kmem_cache_alloc(zio_buf_cache[c], KM_PUSHPAGE)); 221 } 222 223 /* 224 * Use zio_data_buf_alloc to allocate data. The data will not appear in a 225 * crashdump if the kernel panics. This exists so that we will limit the amount 226 * of ZFS data that shows up in a kernel crashdump. (Thus reducing the amount 227 * of kernel heap dumped to disk when the kernel panics) 228 */ 229 void * 230 zio_data_buf_alloc(size_t size) 231 { 232 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 233 234 ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 235 236 return (kmem_cache_alloc(zio_data_buf_cache[c], KM_PUSHPAGE)); 237 } 238 239 void 240 zio_buf_free(void *buf, size_t size) 241 { 242 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 243 244 ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 245 246 kmem_cache_free(zio_buf_cache[c], buf); 247 } 248 249 void 250 zio_data_buf_free(void *buf, size_t size) 251 { 252 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 253 254 ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 255 256 kmem_cache_free(zio_data_buf_cache[c], buf); 257 } 258 259 /* 260 * ========================================================================== 261 * Push and pop I/O transform buffers 262 * ========================================================================== 263 */ 264 static void 265 zio_push_transform(zio_t *zio, void *data, uint64_t size, uint64_t bufsize, 266 zio_transform_func_t *transform) 267 { 268 zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP); 269 270 zt->zt_orig_data = zio->io_data; 271 zt->zt_orig_size = zio->io_size; 272 zt->zt_bufsize = bufsize; 273 zt->zt_transform = transform; 274 275 zt->zt_next = zio->io_transform_stack; 276 zio->io_transform_stack = zt; 277 278 zio->io_data = data; 279 zio->io_size = size; 280 } 281 282 static void 283 zio_pop_transforms(zio_t *zio) 284 { 285 zio_transform_t *zt; 286 287 while ((zt = zio->io_transform_stack) != NULL) { 288 if (zt->zt_transform != NULL) 289 zt->zt_transform(zio, 290 zt->zt_orig_data, zt->zt_orig_size); 291 292 if (zt->zt_bufsize != 0) 293 zio_buf_free(zio->io_data, zt->zt_bufsize); 294 295 zio->io_data = zt->zt_orig_data; 296 zio->io_size = zt->zt_orig_size; 297 zio->io_transform_stack = zt->zt_next; 298 299 kmem_free(zt, sizeof (zio_transform_t)); 300 } 301 } 302 303 /* 304 * ========================================================================== 305 * I/O transform callbacks for subblocks and decompression 306 * ========================================================================== 307 */ 308 static void 309 zio_subblock(zio_t *zio, void *data, uint64_t size) 310 { 311 ASSERT(zio->io_size > size); 312 313 if (zio->io_type == ZIO_TYPE_READ) 314 bcopy(zio->io_data, data, size); 315 } 316 317 static void 318 zio_decompress(zio_t *zio, void *data, uint64_t size) 319 { 320 if (zio->io_error == 0 && 321 zio_decompress_data(BP_GET_COMPRESS(zio->io_bp), 322 zio->io_data, data, zio->io_size, size) != 0) 323 zio->io_error = SET_ERROR(EIO); 324 } 325 326 /* 327 * ========================================================================== 328 * I/O parent/child relationships and pipeline interlocks 329 * ========================================================================== 330 */ 331 /* 332 * NOTE - Callers to zio_walk_parents() and zio_walk_children must 333 * continue calling these functions until they return NULL. 334 * Otherwise, the next caller will pick up the list walk in 335 * some indeterminate state. (Otherwise every caller would 336 * have to pass in a cookie to keep the state represented by 337 * io_walk_link, which gets annoying.) 338 */ 339 zio_t * 340 zio_walk_parents(zio_t *cio) 341 { 342 zio_link_t *zl = cio->io_walk_link; 343 list_t *pl = &cio->io_parent_list; 344 345 zl = (zl == NULL) ? list_head(pl) : list_next(pl, zl); 346 cio->io_walk_link = zl; 347 348 if (zl == NULL) 349 return (NULL); 350 351 ASSERT(zl->zl_child == cio); 352 return (zl->zl_parent); 353 } 354 355 zio_t * 356 zio_walk_children(zio_t *pio) 357 { 358 zio_link_t *zl = pio->io_walk_link; 359 list_t *cl = &pio->io_child_list; 360 361 zl = (zl == NULL) ? list_head(cl) : list_next(cl, zl); 362 pio->io_walk_link = zl; 363 364 if (zl == NULL) 365 return (NULL); 366 367 ASSERT(zl->zl_parent == pio); 368 return (zl->zl_child); 369 } 370 371 zio_t * 372 zio_unique_parent(zio_t *cio) 373 { 374 zio_t *pio = zio_walk_parents(cio); 375 376 VERIFY(zio_walk_parents(cio) == NULL); 377 return (pio); 378 } 379 380 void 381 zio_add_child(zio_t *pio, zio_t *cio) 382 { 383 zio_link_t *zl = kmem_cache_alloc(zio_link_cache, KM_SLEEP); 384 385 /* 386 * Logical I/Os can have logical, gang, or vdev children. 387 * Gang I/Os can have gang or vdev children. 388 * Vdev I/Os can only have vdev children. 389 * The following ASSERT captures all of these constraints. 390 */ 391 ASSERT(cio->io_child_type <= pio->io_child_type); 392 393 zl->zl_parent = pio; 394 zl->zl_child = cio; 395 396 mutex_enter(&cio->io_lock); 397 mutex_enter(&pio->io_lock); 398 399 ASSERT(pio->io_state[ZIO_WAIT_DONE] == 0); 400 401 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 402 pio->io_children[cio->io_child_type][w] += !cio->io_state[w]; 403 404 list_insert_head(&pio->io_child_list, zl); 405 list_insert_head(&cio->io_parent_list, zl); 406 407 pio->io_child_count++; 408 cio->io_parent_count++; 409 410 mutex_exit(&pio->io_lock); 411 mutex_exit(&cio->io_lock); 412 } 413 414 static void 415 zio_remove_child(zio_t *pio, zio_t *cio, zio_link_t *zl) 416 { 417 ASSERT(zl->zl_parent == pio); 418 ASSERT(zl->zl_child == cio); 419 420 mutex_enter(&cio->io_lock); 421 mutex_enter(&pio->io_lock); 422 423 list_remove(&pio->io_child_list, zl); 424 list_remove(&cio->io_parent_list, zl); 425 426 pio->io_child_count--; 427 cio->io_parent_count--; 428 429 mutex_exit(&pio->io_lock); 430 mutex_exit(&cio->io_lock); 431 432 kmem_cache_free(zio_link_cache, zl); 433 } 434 435 static boolean_t 436 zio_wait_for_children(zio_t *zio, enum zio_child child, enum zio_wait_type wait) 437 { 438 uint64_t *countp = &zio->io_children[child][wait]; 439 boolean_t waiting = B_FALSE; 440 441 mutex_enter(&zio->io_lock); 442 ASSERT(zio->io_stall == NULL); 443 if (*countp != 0) { 444 zio->io_stage >>= 1; 445 zio->io_stall = countp; 446 waiting = B_TRUE; 447 } 448 mutex_exit(&zio->io_lock); 449 450 return (waiting); 451 } 452 453 static void 454 zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait) 455 { 456 uint64_t *countp = &pio->io_children[zio->io_child_type][wait]; 457 int *errorp = &pio->io_child_error[zio->io_child_type]; 458 459 mutex_enter(&pio->io_lock); 460 if (zio->io_error && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE)) 461 *errorp = zio_worst_error(*errorp, zio->io_error); 462 pio->io_reexecute |= zio->io_reexecute; 463 ASSERT3U(*countp, >, 0); 464 465 (*countp)--; 466 467 if (*countp == 0 && pio->io_stall == countp) { 468 pio->io_stall = NULL; 469 mutex_exit(&pio->io_lock); 470 zio_execute(pio); 471 } else { 472 mutex_exit(&pio->io_lock); 473 } 474 } 475 476 static void 477 zio_inherit_child_errors(zio_t *zio, enum zio_child c) 478 { 479 if (zio->io_child_error[c] != 0 && zio->io_error == 0) 480 zio->io_error = zio->io_child_error[c]; 481 } 482 483 /* 484 * ========================================================================== 485 * Create the various types of I/O (read, write, free, etc) 486 * ========================================================================== 487 */ 488 static zio_t * 489 zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 490 void *data, uint64_t size, zio_done_func_t *done, void *private, 491 zio_type_t type, zio_priority_t priority, enum zio_flag flags, 492 vdev_t *vd, uint64_t offset, const zbookmark_t *zb, 493 enum zio_stage stage, enum zio_stage pipeline) 494 { 495 zio_t *zio; 496 497 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 498 ASSERT(P2PHASE(size, SPA_MINBLOCKSIZE) == 0); 499 ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0); 500 501 ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER)); 502 ASSERT(!bp || !(flags & ZIO_FLAG_CONFIG_WRITER)); 503 ASSERT(vd || stage == ZIO_STAGE_OPEN); 504 505 zio = kmem_cache_alloc(zio_cache, KM_SLEEP); 506 bzero(zio, sizeof (zio_t)); 507 508 mutex_init(&zio->io_lock, NULL, MUTEX_DEFAULT, NULL); 509 cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL); 510 511 list_create(&zio->io_parent_list, sizeof (zio_link_t), 512 offsetof(zio_link_t, zl_parent_node)); 513 list_create(&zio->io_child_list, sizeof (zio_link_t), 514 offsetof(zio_link_t, zl_child_node)); 515 516 if (vd != NULL) 517 zio->io_child_type = ZIO_CHILD_VDEV; 518 else if (flags & ZIO_FLAG_GANG_CHILD) 519 zio->io_child_type = ZIO_CHILD_GANG; 520 else if (flags & ZIO_FLAG_DDT_CHILD) 521 zio->io_child_type = ZIO_CHILD_DDT; 522 else 523 zio->io_child_type = ZIO_CHILD_LOGICAL; 524 525 if (bp != NULL) { 526 zio->io_bp = (blkptr_t *)bp; 527 zio->io_bp_copy = *bp; 528 zio->io_bp_orig = *bp; 529 if (type != ZIO_TYPE_WRITE || 530 zio->io_child_type == ZIO_CHILD_DDT) 531 zio->io_bp = &zio->io_bp_copy; /* so caller can free */ 532 if (zio->io_child_type == ZIO_CHILD_LOGICAL) 533 zio->io_logical = zio; 534 if (zio->io_child_type > ZIO_CHILD_GANG && BP_IS_GANG(bp)) 535 pipeline |= ZIO_GANG_STAGES; 536 } 537 538 zio->io_spa = spa; 539 zio->io_txg = txg; 540 zio->io_done = done; 541 zio->io_private = private; 542 zio->io_type = type; 543 zio->io_priority = priority; 544 zio->io_vd = vd; 545 zio->io_offset = offset; 546 zio->io_orig_data = zio->io_data = data; 547 zio->io_orig_size = zio->io_size = size; 548 zio->io_orig_flags = zio->io_flags = flags; 549 zio->io_orig_stage = zio->io_stage = stage; 550 zio->io_orig_pipeline = zio->io_pipeline = pipeline; 551 552 zio->io_state[ZIO_WAIT_READY] = (stage >= ZIO_STAGE_READY); 553 zio->io_state[ZIO_WAIT_DONE] = (stage >= ZIO_STAGE_DONE); 554 555 if (zb != NULL) 556 zio->io_bookmark = *zb; 557 558 if (pio != NULL) { 559 if (zio->io_logical == NULL) 560 zio->io_logical = pio->io_logical; 561 if (zio->io_child_type == ZIO_CHILD_GANG) 562 zio->io_gang_leader = pio->io_gang_leader; 563 zio_add_child(pio, zio); 564 } 565 566 return (zio); 567 } 568 569 static void 570 zio_destroy(zio_t *zio) 571 { 572 list_destroy(&zio->io_parent_list); 573 list_destroy(&zio->io_child_list); 574 mutex_destroy(&zio->io_lock); 575 cv_destroy(&zio->io_cv); 576 kmem_cache_free(zio_cache, zio); 577 } 578 579 zio_t * 580 zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, zio_done_func_t *done, 581 void *private, enum zio_flag flags) 582 { 583 zio_t *zio; 584 585 zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private, 586 ZIO_TYPE_NULL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL, 587 ZIO_STAGE_OPEN, ZIO_INTERLOCK_PIPELINE); 588 589 return (zio); 590 } 591 592 zio_t * 593 zio_root(spa_t *spa, zio_done_func_t *done, void *private, enum zio_flag flags) 594 { 595 return (zio_null(NULL, spa, NULL, done, private, flags)); 596 } 597 598 zio_t * 599 zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, 600 void *data, uint64_t size, zio_done_func_t *done, void *private, 601 zio_priority_t priority, enum zio_flag flags, const zbookmark_t *zb) 602 { 603 zio_t *zio; 604 605 zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp, 606 data, size, done, private, 607 ZIO_TYPE_READ, priority, flags, NULL, 0, zb, 608 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 609 ZIO_DDT_CHILD_READ_PIPELINE : ZIO_READ_PIPELINE); 610 611 return (zio); 612 } 613 614 zio_t * 615 zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, 616 void *data, uint64_t size, const zio_prop_t *zp, 617 zio_done_func_t *ready, zio_done_func_t *physdone, zio_done_func_t *done, 618 void *private, 619 zio_priority_t priority, enum zio_flag flags, const zbookmark_t *zb) 620 { 621 zio_t *zio; 622 623 ASSERT(zp->zp_checksum >= ZIO_CHECKSUM_OFF && 624 zp->zp_checksum < ZIO_CHECKSUM_FUNCTIONS && 625 zp->zp_compress >= ZIO_COMPRESS_OFF && 626 zp->zp_compress < ZIO_COMPRESS_FUNCTIONS && 627 DMU_OT_IS_VALID(zp->zp_type) && 628 zp->zp_level < 32 && 629 zp->zp_copies > 0 && 630 zp->zp_copies <= spa_max_replication(spa)); 631 632 zio = zio_create(pio, spa, txg, bp, data, size, done, private, 633 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 634 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 635 ZIO_DDT_CHILD_WRITE_PIPELINE : ZIO_WRITE_PIPELINE); 636 637 zio->io_ready = ready; 638 zio->io_physdone = physdone; 639 zio->io_prop = *zp; 640 641 /* 642 * Data can be NULL if we are going to call zio_write_override() to 643 * provide the already-allocated BP. But we may need the data to 644 * verify a dedup hit (if requested). In this case, don't try to 645 * dedup (just take the already-allocated BP verbatim). 646 */ 647 if (data == NULL && zio->io_prop.zp_dedup_verify) { 648 zio->io_prop.zp_dedup = zio->io_prop.zp_dedup_verify = B_FALSE; 649 } 650 651 return (zio); 652 } 653 654 zio_t * 655 zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, void *data, 656 uint64_t size, zio_done_func_t *done, void *private, 657 zio_priority_t priority, enum zio_flag flags, zbookmark_t *zb) 658 { 659 zio_t *zio; 660 661 zio = zio_create(pio, spa, txg, bp, data, size, done, private, 662 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 663 ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE); 664 665 return (zio); 666 } 667 668 void 669 zio_write_override(zio_t *zio, blkptr_t *bp, int copies, boolean_t nopwrite) 670 { 671 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 672 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 673 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 674 ASSERT(zio->io_txg == spa_syncing_txg(zio->io_spa)); 675 676 /* 677 * We must reset the io_prop to match the values that existed 678 * when the bp was first written by dmu_sync() keeping in mind 679 * that nopwrite and dedup are mutually exclusive. 680 */ 681 zio->io_prop.zp_dedup = nopwrite ? B_FALSE : zio->io_prop.zp_dedup; 682 zio->io_prop.zp_nopwrite = nopwrite; 683 zio->io_prop.zp_copies = copies; 684 zio->io_bp_override = bp; 685 } 686 687 void 688 zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp) 689 { 690 691 /* 692 * The check for EMBEDDED is a performance optimization. We 693 * process the free here (by ignoring it) rather than 694 * putting it on the list and then processing it in zio_free_sync(). 695 */ 696 if (BP_IS_EMBEDDED(bp)) 697 return; 698 metaslab_check_free(spa, bp); 699 700 /* 701 * Frees that are for the currently-syncing txg, are not going to be 702 * deferred, and which will not need to do a read (i.e. not GANG or 703 * DEDUP), can be processed immediately. Otherwise, put them on the 704 * in-memory list for later processing. 705 */ 706 if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp) || 707 txg != spa->spa_syncing_txg || 708 spa_sync_pass(spa) >= zfs_sync_pass_deferred_free) { 709 bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp); 710 } else { 711 VERIFY0(zio_wait(zio_free_sync(NULL, spa, txg, bp, 0))); 712 } 713 } 714 715 zio_t * 716 zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 717 enum zio_flag flags) 718 { 719 zio_t *zio; 720 enum zio_stage stage = ZIO_FREE_PIPELINE; 721 722 ASSERT(!BP_IS_HOLE(bp)); 723 ASSERT(spa_syncing_txg(spa) == txg); 724 ASSERT(spa_sync_pass(spa) < zfs_sync_pass_deferred_free); 725 726 if (BP_IS_EMBEDDED(bp)) 727 return (zio_null(pio, spa, NULL, NULL, NULL, 0)); 728 729 metaslab_check_free(spa, bp); 730 arc_freed(spa, bp); 731 732 /* 733 * GANG and DEDUP blocks can induce a read (for the gang block header, 734 * or the DDT), so issue them asynchronously so that this thread is 735 * not tied up. 736 */ 737 if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp)) 738 stage |= ZIO_STAGE_ISSUE_ASYNC; 739 740 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 741 NULL, NULL, ZIO_TYPE_FREE, ZIO_PRIORITY_NOW, flags, 742 NULL, 0, NULL, ZIO_STAGE_OPEN, stage); 743 744 return (zio); 745 } 746 747 zio_t * 748 zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 749 zio_done_func_t *done, void *private, enum zio_flag flags) 750 { 751 zio_t *zio; 752 753 dprintf_bp(bp, "claiming in txg %llu", txg); 754 755 if (BP_IS_EMBEDDED(bp)) 756 return (zio_null(pio, spa, NULL, NULL, NULL, 0)); 757 758 /* 759 * A claim is an allocation of a specific block. Claims are needed 760 * to support immediate writes in the intent log. The issue is that 761 * immediate writes contain committed data, but in a txg that was 762 * *not* committed. Upon opening the pool after an unclean shutdown, 763 * the intent log claims all blocks that contain immediate write data 764 * so that the SPA knows they're in use. 765 * 766 * All claims *must* be resolved in the first txg -- before the SPA 767 * starts allocating blocks -- so that nothing is allocated twice. 768 * If txg == 0 we just verify that the block is claimable. 769 */ 770 ASSERT3U(spa->spa_uberblock.ub_rootbp.blk_birth, <, spa_first_txg(spa)); 771 ASSERT(txg == spa_first_txg(spa) || txg == 0); 772 ASSERT(!BP_GET_DEDUP(bp) || !spa_writeable(spa)); /* zdb(1M) */ 773 774 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 775 done, private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW, flags, 776 NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE); 777 778 return (zio); 779 } 780 781 zio_t * 782 zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd, 783 zio_done_func_t *done, void *private, enum zio_flag flags) 784 { 785 zio_t *zio; 786 int c; 787 788 if (vd->vdev_children == 0) { 789 zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private, 790 ZIO_TYPE_IOCTL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL, 791 ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE); 792 793 zio->io_cmd = cmd; 794 } else { 795 zio = zio_null(pio, spa, NULL, NULL, NULL, flags); 796 797 for (c = 0; c < vd->vdev_children; c++) 798 zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd, 799 done, private, flags)); 800 } 801 802 return (zio); 803 } 804 805 zio_t * 806 zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 807 void *data, int checksum, zio_done_func_t *done, void *private, 808 zio_priority_t priority, enum zio_flag flags, boolean_t labels) 809 { 810 zio_t *zio; 811 812 ASSERT(vd->vdev_children == 0); 813 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 814 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 815 ASSERT3U(offset + size, <=, vd->vdev_psize); 816 817 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private, 818 ZIO_TYPE_READ, priority, flags, vd, offset, NULL, 819 ZIO_STAGE_OPEN, ZIO_READ_PHYS_PIPELINE); 820 821 zio->io_prop.zp_checksum = checksum; 822 823 return (zio); 824 } 825 826 zio_t * 827 zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 828 void *data, int checksum, zio_done_func_t *done, void *private, 829 zio_priority_t priority, enum zio_flag flags, boolean_t labels) 830 { 831 zio_t *zio; 832 833 ASSERT(vd->vdev_children == 0); 834 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 835 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 836 ASSERT3U(offset + size, <=, vd->vdev_psize); 837 838 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private, 839 ZIO_TYPE_WRITE, priority, flags, vd, offset, NULL, 840 ZIO_STAGE_OPEN, ZIO_WRITE_PHYS_PIPELINE); 841 842 zio->io_prop.zp_checksum = checksum; 843 844 if (zio_checksum_table[checksum].ci_eck) { 845 /* 846 * zec checksums are necessarily destructive -- they modify 847 * the end of the write buffer to hold the verifier/checksum. 848 * Therefore, we must make a local copy in case the data is 849 * being written to multiple places in parallel. 850 */ 851 void *wbuf = zio_buf_alloc(size); 852 bcopy(data, wbuf, size); 853 zio_push_transform(zio, wbuf, size, size, NULL); 854 } 855 856 return (zio); 857 } 858 859 /* 860 * Create a child I/O to do some work for us. 861 */ 862 zio_t * 863 zio_vdev_child_io(zio_t *pio, blkptr_t *bp, vdev_t *vd, uint64_t offset, 864 void *data, uint64_t size, int type, zio_priority_t priority, 865 enum zio_flag flags, zio_done_func_t *done, void *private) 866 { 867 enum zio_stage pipeline = ZIO_VDEV_CHILD_PIPELINE; 868 zio_t *zio; 869 870 ASSERT(vd->vdev_parent == 871 (pio->io_vd ? pio->io_vd : pio->io_spa->spa_root_vdev)); 872 873 if (type == ZIO_TYPE_READ && bp != NULL) { 874 /* 875 * If we have the bp, then the child should perform the 876 * checksum and the parent need not. This pushes error 877 * detection as close to the leaves as possible and 878 * eliminates redundant checksums in the interior nodes. 879 */ 880 pipeline |= ZIO_STAGE_CHECKSUM_VERIFY; 881 pio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 882 } 883 884 if (vd->vdev_children == 0) 885 offset += VDEV_LABEL_START_SIZE; 886 887 flags |= ZIO_VDEV_CHILD_FLAGS(pio) | ZIO_FLAG_DONT_PROPAGATE; 888 889 /* 890 * If we've decided to do a repair, the write is not speculative -- 891 * even if the original read was. 892 */ 893 if (flags & ZIO_FLAG_IO_REPAIR) 894 flags &= ~ZIO_FLAG_SPECULATIVE; 895 896 zio = zio_create(pio, pio->io_spa, pio->io_txg, bp, data, size, 897 done, private, type, priority, flags, vd, offset, &pio->io_bookmark, 898 ZIO_STAGE_VDEV_IO_START >> 1, pipeline); 899 900 zio->io_physdone = pio->io_physdone; 901 if (vd->vdev_ops->vdev_op_leaf && zio->io_logical != NULL) 902 zio->io_logical->io_phys_children++; 903 904 return (zio); 905 } 906 907 zio_t * 908 zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, void *data, uint64_t size, 909 int type, zio_priority_t priority, enum zio_flag flags, 910 zio_done_func_t *done, void *private) 911 { 912 zio_t *zio; 913 914 ASSERT(vd->vdev_ops->vdev_op_leaf); 915 916 zio = zio_create(NULL, vd->vdev_spa, 0, NULL, 917 data, size, done, private, type, priority, 918 flags | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY | ZIO_FLAG_DELEGATED, 919 vd, offset, NULL, 920 ZIO_STAGE_VDEV_IO_START >> 1, ZIO_VDEV_CHILD_PIPELINE); 921 922 return (zio); 923 } 924 925 void 926 zio_flush(zio_t *zio, vdev_t *vd) 927 { 928 zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE, 929 NULL, NULL, 930 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY)); 931 } 932 933 void 934 zio_shrink(zio_t *zio, uint64_t size) 935 { 936 ASSERT(zio->io_executor == NULL); 937 ASSERT(zio->io_orig_size == zio->io_size); 938 ASSERT(size <= zio->io_size); 939 940 /* 941 * We don't shrink for raidz because of problems with the 942 * reconstruction when reading back less than the block size. 943 * Note, BP_IS_RAIDZ() assumes no compression. 944 */ 945 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 946 if (!BP_IS_RAIDZ(zio->io_bp)) 947 zio->io_orig_size = zio->io_size = size; 948 } 949 950 /* 951 * ========================================================================== 952 * Prepare to read and write logical blocks 953 * ========================================================================== 954 */ 955 956 static int 957 zio_read_bp_init(zio_t *zio) 958 { 959 blkptr_t *bp = zio->io_bp; 960 961 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF && 962 zio->io_child_type == ZIO_CHILD_LOGICAL && 963 !(zio->io_flags & ZIO_FLAG_RAW)) { 964 uint64_t psize = 965 BP_IS_EMBEDDED(bp) ? BPE_GET_PSIZE(bp) : BP_GET_PSIZE(bp); 966 void *cbuf = zio_buf_alloc(psize); 967 968 zio_push_transform(zio, cbuf, psize, psize, zio_decompress); 969 } 970 971 if (BP_IS_EMBEDDED(bp) && BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA) { 972 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 973 decode_embedded_bp_compressed(bp, zio->io_data); 974 } else { 975 ASSERT(!BP_IS_EMBEDDED(bp)); 976 } 977 978 if (!DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) && BP_GET_LEVEL(bp) == 0) 979 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 980 981 if (BP_GET_TYPE(bp) == DMU_OT_DDT_ZAP) 982 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 983 984 if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL) 985 zio->io_pipeline = ZIO_DDT_READ_PIPELINE; 986 987 return (ZIO_PIPELINE_CONTINUE); 988 } 989 990 static int 991 zio_write_bp_init(zio_t *zio) 992 { 993 spa_t *spa = zio->io_spa; 994 zio_prop_t *zp = &zio->io_prop; 995 enum zio_compress compress = zp->zp_compress; 996 blkptr_t *bp = zio->io_bp; 997 uint64_t lsize = zio->io_size; 998 uint64_t psize = lsize; 999 int pass = 1; 1000 1001 /* 1002 * If our children haven't all reached the ready stage, 1003 * wait for them and then repeat this pipeline stage. 1004 */ 1005 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 1006 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_READY)) 1007 return (ZIO_PIPELINE_STOP); 1008 1009 if (!IO_IS_ALLOCATING(zio)) 1010 return (ZIO_PIPELINE_CONTINUE); 1011 1012 ASSERT(zio->io_child_type != ZIO_CHILD_DDT); 1013 1014 if (zio->io_bp_override) { 1015 ASSERT(bp->blk_birth != zio->io_txg); 1016 ASSERT(BP_GET_DEDUP(zio->io_bp_override) == 0); 1017 1018 *bp = *zio->io_bp_override; 1019 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1020 1021 if (BP_IS_EMBEDDED(bp)) 1022 return (ZIO_PIPELINE_CONTINUE); 1023 1024 /* 1025 * If we've been overridden and nopwrite is set then 1026 * set the flag accordingly to indicate that a nopwrite 1027 * has already occurred. 1028 */ 1029 if (!BP_IS_HOLE(bp) && zp->zp_nopwrite) { 1030 ASSERT(!zp->zp_dedup); 1031 zio->io_flags |= ZIO_FLAG_NOPWRITE; 1032 return (ZIO_PIPELINE_CONTINUE); 1033 } 1034 1035 ASSERT(!zp->zp_nopwrite); 1036 1037 if (BP_IS_HOLE(bp) || !zp->zp_dedup) 1038 return (ZIO_PIPELINE_CONTINUE); 1039 1040 ASSERT(zio_checksum_table[zp->zp_checksum].ci_dedup || 1041 zp->zp_dedup_verify); 1042 1043 if (BP_GET_CHECKSUM(bp) == zp->zp_checksum) { 1044 BP_SET_DEDUP(bp, 1); 1045 zio->io_pipeline |= ZIO_STAGE_DDT_WRITE; 1046 return (ZIO_PIPELINE_CONTINUE); 1047 } 1048 zio->io_bp_override = NULL; 1049 BP_ZERO(bp); 1050 } 1051 1052 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg) { 1053 /* 1054 * We're rewriting an existing block, which means we're 1055 * working on behalf of spa_sync(). For spa_sync() to 1056 * converge, it must eventually be the case that we don't 1057 * have to allocate new blocks. But compression changes 1058 * the blocksize, which forces a reallocate, and makes 1059 * convergence take longer. Therefore, after the first 1060 * few passes, stop compressing to ensure convergence. 1061 */ 1062 pass = spa_sync_pass(spa); 1063 1064 ASSERT(zio->io_txg == spa_syncing_txg(spa)); 1065 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1066 ASSERT(!BP_GET_DEDUP(bp)); 1067 1068 if (pass >= zfs_sync_pass_dont_compress) 1069 compress = ZIO_COMPRESS_OFF; 1070 1071 /* Make sure someone doesn't change their mind on overwrites */ 1072 ASSERT(BP_IS_EMBEDDED(bp) || MIN(zp->zp_copies + BP_IS_GANG(bp), 1073 spa_max_replication(spa)) == BP_GET_NDVAS(bp)); 1074 } 1075 1076 if (compress != ZIO_COMPRESS_OFF) { 1077 void *cbuf = zio_buf_alloc(lsize); 1078 psize = zio_compress_data(compress, zio->io_data, cbuf, lsize); 1079 if (psize == 0 || psize == lsize) { 1080 compress = ZIO_COMPRESS_OFF; 1081 zio_buf_free(cbuf, lsize); 1082 } else if (!zp->zp_dedup && psize <= BPE_PAYLOAD_SIZE && 1083 zp->zp_level == 0 && !DMU_OT_HAS_FILL(zp->zp_type) && 1084 spa_feature_is_enabled(spa, SPA_FEATURE_EMBEDDED_DATA)) { 1085 encode_embedded_bp_compressed(bp, 1086 cbuf, compress, lsize, psize); 1087 BPE_SET_ETYPE(bp, BP_EMBEDDED_TYPE_DATA); 1088 BP_SET_TYPE(bp, zio->io_prop.zp_type); 1089 BP_SET_LEVEL(bp, zio->io_prop.zp_level); 1090 zio_buf_free(cbuf, lsize); 1091 bp->blk_birth = zio->io_txg; 1092 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1093 ASSERT(spa_feature_is_active(spa, 1094 SPA_FEATURE_EMBEDDED_DATA)); 1095 return (ZIO_PIPELINE_CONTINUE); 1096 } else { 1097 /* 1098 * Round up compressed size to MINBLOCKSIZE and 1099 * zero the tail. 1100 */ 1101 size_t rounded = 1102 P2ROUNDUP(psize, (size_t)SPA_MINBLOCKSIZE); 1103 if (rounded > psize) { 1104 bzero((char *)cbuf + psize, rounded - psize); 1105 psize = rounded; 1106 } 1107 if (psize == lsize) { 1108 compress = ZIO_COMPRESS_OFF; 1109 zio_buf_free(cbuf, lsize); 1110 } else { 1111 zio_push_transform(zio, cbuf, 1112 psize, lsize, NULL); 1113 } 1114 } 1115 } 1116 1117 /* 1118 * The final pass of spa_sync() must be all rewrites, but the first 1119 * few passes offer a trade-off: allocating blocks defers convergence, 1120 * but newly allocated blocks are sequential, so they can be written 1121 * to disk faster. Therefore, we allow the first few passes of 1122 * spa_sync() to allocate new blocks, but force rewrites after that. 1123 * There should only be a handful of blocks after pass 1 in any case. 1124 */ 1125 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg && 1126 BP_GET_PSIZE(bp) == psize && 1127 pass >= zfs_sync_pass_rewrite) { 1128 ASSERT(psize != 0); 1129 enum zio_stage gang_stages = zio->io_pipeline & ZIO_GANG_STAGES; 1130 zio->io_pipeline = ZIO_REWRITE_PIPELINE | gang_stages; 1131 zio->io_flags |= ZIO_FLAG_IO_REWRITE; 1132 } else { 1133 BP_ZERO(bp); 1134 zio->io_pipeline = ZIO_WRITE_PIPELINE; 1135 } 1136 1137 if (psize == 0) { 1138 if (zio->io_bp_orig.blk_birth != 0 && 1139 spa_feature_is_active(spa, SPA_FEATURE_HOLE_BIRTH)) { 1140 BP_SET_LSIZE(bp, lsize); 1141 BP_SET_TYPE(bp, zp->zp_type); 1142 BP_SET_LEVEL(bp, zp->zp_level); 1143 BP_SET_BIRTH(bp, zio->io_txg, 0); 1144 } 1145 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1146 } else { 1147 ASSERT(zp->zp_checksum != ZIO_CHECKSUM_GANG_HEADER); 1148 BP_SET_LSIZE(bp, lsize); 1149 BP_SET_TYPE(bp, zp->zp_type); 1150 BP_SET_LEVEL(bp, zp->zp_level); 1151 BP_SET_PSIZE(bp, psize); 1152 BP_SET_COMPRESS(bp, compress); 1153 BP_SET_CHECKSUM(bp, zp->zp_checksum); 1154 BP_SET_DEDUP(bp, zp->zp_dedup); 1155 BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER); 1156 if (zp->zp_dedup) { 1157 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1158 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1159 zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE; 1160 } 1161 if (zp->zp_nopwrite) { 1162 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1163 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1164 zio->io_pipeline |= ZIO_STAGE_NOP_WRITE; 1165 } 1166 } 1167 1168 return (ZIO_PIPELINE_CONTINUE); 1169 } 1170 1171 static int 1172 zio_free_bp_init(zio_t *zio) 1173 { 1174 blkptr_t *bp = zio->io_bp; 1175 1176 if (zio->io_child_type == ZIO_CHILD_LOGICAL) { 1177 if (BP_GET_DEDUP(bp)) 1178 zio->io_pipeline = ZIO_DDT_FREE_PIPELINE; 1179 } 1180 1181 return (ZIO_PIPELINE_CONTINUE); 1182 } 1183 1184 /* 1185 * ========================================================================== 1186 * Execute the I/O pipeline 1187 * ========================================================================== 1188 */ 1189 1190 static void 1191 zio_taskq_dispatch(zio_t *zio, zio_taskq_type_t q, boolean_t cutinline) 1192 { 1193 spa_t *spa = zio->io_spa; 1194 zio_type_t t = zio->io_type; 1195 int flags = (cutinline ? TQ_FRONT : 0); 1196 1197 /* 1198 * If we're a config writer or a probe, the normal issue and 1199 * interrupt threads may all be blocked waiting for the config lock. 1200 * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL. 1201 */ 1202 if (zio->io_flags & (ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_PROBE)) 1203 t = ZIO_TYPE_NULL; 1204 1205 /* 1206 * A similar issue exists for the L2ARC write thread until L2ARC 2.0. 1207 */ 1208 if (t == ZIO_TYPE_WRITE && zio->io_vd && zio->io_vd->vdev_aux) 1209 t = ZIO_TYPE_NULL; 1210 1211 /* 1212 * If this is a high priority I/O, then use the high priority taskq if 1213 * available. 1214 */ 1215 if (zio->io_priority == ZIO_PRIORITY_NOW && 1216 spa->spa_zio_taskq[t][q + 1].stqs_count != 0) 1217 q++; 1218 1219 ASSERT3U(q, <, ZIO_TASKQ_TYPES); 1220 1221 /* 1222 * NB: We are assuming that the zio can only be dispatched 1223 * to a single taskq at a time. It would be a grievous error 1224 * to dispatch the zio to another taskq at the same time. 1225 */ 1226 ASSERT(zio->io_tqent.tqent_next == NULL); 1227 spa_taskq_dispatch_ent(spa, t, q, (task_func_t *)zio_execute, zio, 1228 flags, &zio->io_tqent); 1229 } 1230 1231 static boolean_t 1232 zio_taskq_member(zio_t *zio, zio_taskq_type_t q) 1233 { 1234 kthread_t *executor = zio->io_executor; 1235 spa_t *spa = zio->io_spa; 1236 1237 for (zio_type_t t = 0; t < ZIO_TYPES; t++) { 1238 spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q]; 1239 uint_t i; 1240 for (i = 0; i < tqs->stqs_count; i++) { 1241 if (taskq_member(tqs->stqs_taskq[i], executor)) 1242 return (B_TRUE); 1243 } 1244 } 1245 1246 return (B_FALSE); 1247 } 1248 1249 static int 1250 zio_issue_async(zio_t *zio) 1251 { 1252 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 1253 1254 return (ZIO_PIPELINE_STOP); 1255 } 1256 1257 void 1258 zio_interrupt(zio_t *zio) 1259 { 1260 zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE); 1261 } 1262 1263 /* 1264 * Execute the I/O pipeline until one of the following occurs: 1265 * 1266 * (1) the I/O completes 1267 * (2) the pipeline stalls waiting for dependent child I/Os 1268 * (3) the I/O issues, so we're waiting for an I/O completion interrupt 1269 * (4) the I/O is delegated by vdev-level caching or aggregation 1270 * (5) the I/O is deferred due to vdev-level queueing 1271 * (6) the I/O is handed off to another thread. 1272 * 1273 * In all cases, the pipeline stops whenever there's no CPU work; it never 1274 * burns a thread in cv_wait(). 1275 * 1276 * There's no locking on io_stage because there's no legitimate way 1277 * for multiple threads to be attempting to process the same I/O. 1278 */ 1279 static zio_pipe_stage_t *zio_pipeline[]; 1280 1281 void 1282 zio_execute(zio_t *zio) 1283 { 1284 zio->io_executor = curthread; 1285 1286 while (zio->io_stage < ZIO_STAGE_DONE) { 1287 enum zio_stage pipeline = zio->io_pipeline; 1288 enum zio_stage stage = zio->io_stage; 1289 int rv; 1290 1291 ASSERT(!MUTEX_HELD(&zio->io_lock)); 1292 ASSERT(ISP2(stage)); 1293 ASSERT(zio->io_stall == NULL); 1294 1295 do { 1296 stage <<= 1; 1297 } while ((stage & pipeline) == 0); 1298 1299 ASSERT(stage <= ZIO_STAGE_DONE); 1300 1301 /* 1302 * If we are in interrupt context and this pipeline stage 1303 * will grab a config lock that is held across I/O, 1304 * or may wait for an I/O that needs an interrupt thread 1305 * to complete, issue async to avoid deadlock. 1306 * 1307 * For VDEV_IO_START, we cut in line so that the io will 1308 * be sent to disk promptly. 1309 */ 1310 if ((stage & ZIO_BLOCKING_STAGES) && zio->io_vd == NULL && 1311 zio_taskq_member(zio, ZIO_TASKQ_INTERRUPT)) { 1312 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ? 1313 zio_requeue_io_start_cut_in_line : B_FALSE; 1314 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut); 1315 return; 1316 } 1317 1318 zio->io_stage = stage; 1319 rv = zio_pipeline[highbit64(stage) - 1](zio); 1320 1321 if (rv == ZIO_PIPELINE_STOP) 1322 return; 1323 1324 ASSERT(rv == ZIO_PIPELINE_CONTINUE); 1325 } 1326 } 1327 1328 /* 1329 * ========================================================================== 1330 * Initiate I/O, either sync or async 1331 * ========================================================================== 1332 */ 1333 int 1334 zio_wait(zio_t *zio) 1335 { 1336 int error; 1337 1338 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 1339 ASSERT(zio->io_executor == NULL); 1340 1341 zio->io_waiter = curthread; 1342 1343 zio_execute(zio); 1344 1345 mutex_enter(&zio->io_lock); 1346 while (zio->io_executor != NULL) 1347 cv_wait(&zio->io_cv, &zio->io_lock); 1348 mutex_exit(&zio->io_lock); 1349 1350 error = zio->io_error; 1351 zio_destroy(zio); 1352 1353 return (error); 1354 } 1355 1356 void 1357 zio_nowait(zio_t *zio) 1358 { 1359 ASSERT(zio->io_executor == NULL); 1360 1361 if (zio->io_child_type == ZIO_CHILD_LOGICAL && 1362 zio_unique_parent(zio) == NULL) { 1363 /* 1364 * This is a logical async I/O with no parent to wait for it. 1365 * We add it to the spa_async_root_zio "Godfather" I/O which 1366 * will ensure they complete prior to unloading the pool. 1367 */ 1368 spa_t *spa = zio->io_spa; 1369 1370 zio_add_child(spa->spa_async_zio_root, zio); 1371 } 1372 1373 zio_execute(zio); 1374 } 1375 1376 /* 1377 * ========================================================================== 1378 * Reexecute or suspend/resume failed I/O 1379 * ========================================================================== 1380 */ 1381 1382 static void 1383 zio_reexecute(zio_t *pio) 1384 { 1385 zio_t *cio, *cio_next; 1386 1387 ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL); 1388 ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN); 1389 ASSERT(pio->io_gang_leader == NULL); 1390 ASSERT(pio->io_gang_tree == NULL); 1391 1392 pio->io_flags = pio->io_orig_flags; 1393 pio->io_stage = pio->io_orig_stage; 1394 pio->io_pipeline = pio->io_orig_pipeline; 1395 pio->io_reexecute = 0; 1396 pio->io_flags |= ZIO_FLAG_REEXECUTED; 1397 pio->io_error = 0; 1398 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1399 pio->io_state[w] = 0; 1400 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 1401 pio->io_child_error[c] = 0; 1402 1403 if (IO_IS_ALLOCATING(pio)) 1404 BP_ZERO(pio->io_bp); 1405 1406 /* 1407 * As we reexecute pio's children, new children could be created. 1408 * New children go to the head of pio's io_child_list, however, 1409 * so we will (correctly) not reexecute them. The key is that 1410 * the remainder of pio's io_child_list, from 'cio_next' onward, 1411 * cannot be affected by any side effects of reexecuting 'cio'. 1412 */ 1413 for (cio = zio_walk_children(pio); cio != NULL; cio = cio_next) { 1414 cio_next = zio_walk_children(pio); 1415 mutex_enter(&pio->io_lock); 1416 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1417 pio->io_children[cio->io_child_type][w]++; 1418 mutex_exit(&pio->io_lock); 1419 zio_reexecute(cio); 1420 } 1421 1422 /* 1423 * Now that all children have been reexecuted, execute the parent. 1424 * We don't reexecute "The Godfather" I/O here as it's the 1425 * responsibility of the caller to wait on him. 1426 */ 1427 if (!(pio->io_flags & ZIO_FLAG_GODFATHER)) 1428 zio_execute(pio); 1429 } 1430 1431 void 1432 zio_suspend(spa_t *spa, zio_t *zio) 1433 { 1434 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC) 1435 fm_panic("Pool '%s' has encountered an uncorrectable I/O " 1436 "failure and the failure mode property for this pool " 1437 "is set to panic.", spa_name(spa)); 1438 1439 zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL, NULL, 0, 0); 1440 1441 mutex_enter(&spa->spa_suspend_lock); 1442 1443 if (spa->spa_suspend_zio_root == NULL) 1444 spa->spa_suspend_zio_root = zio_root(spa, NULL, NULL, 1445 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | 1446 ZIO_FLAG_GODFATHER); 1447 1448 spa->spa_suspended = B_TRUE; 1449 1450 if (zio != NULL) { 1451 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 1452 ASSERT(zio != spa->spa_suspend_zio_root); 1453 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1454 ASSERT(zio_unique_parent(zio) == NULL); 1455 ASSERT(zio->io_stage == ZIO_STAGE_DONE); 1456 zio_add_child(spa->spa_suspend_zio_root, zio); 1457 } 1458 1459 mutex_exit(&spa->spa_suspend_lock); 1460 } 1461 1462 int 1463 zio_resume(spa_t *spa) 1464 { 1465 zio_t *pio; 1466 1467 /* 1468 * Reexecute all previously suspended i/o. 1469 */ 1470 mutex_enter(&spa->spa_suspend_lock); 1471 spa->spa_suspended = B_FALSE; 1472 cv_broadcast(&spa->spa_suspend_cv); 1473 pio = spa->spa_suspend_zio_root; 1474 spa->spa_suspend_zio_root = NULL; 1475 mutex_exit(&spa->spa_suspend_lock); 1476 1477 if (pio == NULL) 1478 return (0); 1479 1480 zio_reexecute(pio); 1481 return (zio_wait(pio)); 1482 } 1483 1484 void 1485 zio_resume_wait(spa_t *spa) 1486 { 1487 mutex_enter(&spa->spa_suspend_lock); 1488 while (spa_suspended(spa)) 1489 cv_wait(&spa->spa_suspend_cv, &spa->spa_suspend_lock); 1490 mutex_exit(&spa->spa_suspend_lock); 1491 } 1492 1493 /* 1494 * ========================================================================== 1495 * Gang blocks. 1496 * 1497 * A gang block is a collection of small blocks that looks to the DMU 1498 * like one large block. When zio_dva_allocate() cannot find a block 1499 * of the requested size, due to either severe fragmentation or the pool 1500 * being nearly full, it calls zio_write_gang_block() to construct the 1501 * block from smaller fragments. 1502 * 1503 * A gang block consists of a gang header (zio_gbh_phys_t) and up to 1504 * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like 1505 * an indirect block: it's an array of block pointers. It consumes 1506 * only one sector and hence is allocatable regardless of fragmentation. 1507 * The gang header's bps point to its gang members, which hold the data. 1508 * 1509 * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg> 1510 * as the verifier to ensure uniqueness of the SHA256 checksum. 1511 * Critically, the gang block bp's blk_cksum is the checksum of the data, 1512 * not the gang header. This ensures that data block signatures (needed for 1513 * deduplication) are independent of how the block is physically stored. 1514 * 1515 * Gang blocks can be nested: a gang member may itself be a gang block. 1516 * Thus every gang block is a tree in which root and all interior nodes are 1517 * gang headers, and the leaves are normal blocks that contain user data. 1518 * The root of the gang tree is called the gang leader. 1519 * 1520 * To perform any operation (read, rewrite, free, claim) on a gang block, 1521 * zio_gang_assemble() first assembles the gang tree (minus data leaves) 1522 * in the io_gang_tree field of the original logical i/o by recursively 1523 * reading the gang leader and all gang headers below it. This yields 1524 * an in-core tree containing the contents of every gang header and the 1525 * bps for every constituent of the gang block. 1526 * 1527 * With the gang tree now assembled, zio_gang_issue() just walks the gang tree 1528 * and invokes a callback on each bp. To free a gang block, zio_gang_issue() 1529 * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp. 1530 * zio_claim_gang() provides a similarly trivial wrapper for zio_claim(). 1531 * zio_read_gang() is a wrapper around zio_read() that omits reading gang 1532 * headers, since we already have those in io_gang_tree. zio_rewrite_gang() 1533 * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite() 1534 * of the gang header plus zio_checksum_compute() of the data to update the 1535 * gang header's blk_cksum as described above. 1536 * 1537 * The two-phase assemble/issue model solves the problem of partial failure -- 1538 * what if you'd freed part of a gang block but then couldn't read the 1539 * gang header for another part? Assembling the entire gang tree first 1540 * ensures that all the necessary gang header I/O has succeeded before 1541 * starting the actual work of free, claim, or write. Once the gang tree 1542 * is assembled, free and claim are in-memory operations that cannot fail. 1543 * 1544 * In the event that a gang write fails, zio_dva_unallocate() walks the 1545 * gang tree to immediately free (i.e. insert back into the space map) 1546 * everything we've allocated. This ensures that we don't get ENOSPC 1547 * errors during repeated suspend/resume cycles due to a flaky device. 1548 * 1549 * Gang rewrites only happen during sync-to-convergence. If we can't assemble 1550 * the gang tree, we won't modify the block, so we can safely defer the free 1551 * (knowing that the block is still intact). If we *can* assemble the gang 1552 * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free 1553 * each constituent bp and we can allocate a new block on the next sync pass. 1554 * 1555 * In all cases, the gang tree allows complete recovery from partial failure. 1556 * ========================================================================== 1557 */ 1558 1559 static zio_t * 1560 zio_read_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1561 { 1562 if (gn != NULL) 1563 return (pio); 1564 1565 return (zio_read(pio, pio->io_spa, bp, data, BP_GET_PSIZE(bp), 1566 NULL, NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 1567 &pio->io_bookmark)); 1568 } 1569 1570 zio_t * 1571 zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1572 { 1573 zio_t *zio; 1574 1575 if (gn != NULL) { 1576 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1577 gn->gn_gbh, SPA_GANGBLOCKSIZE, NULL, NULL, pio->io_priority, 1578 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1579 /* 1580 * As we rewrite each gang header, the pipeline will compute 1581 * a new gang block header checksum for it; but no one will 1582 * compute a new data checksum, so we do that here. The one 1583 * exception is the gang leader: the pipeline already computed 1584 * its data checksum because that stage precedes gang assembly. 1585 * (Presently, nothing actually uses interior data checksums; 1586 * this is just good hygiene.) 1587 */ 1588 if (gn != pio->io_gang_leader->io_gang_tree) { 1589 zio_checksum_compute(zio, BP_GET_CHECKSUM(bp), 1590 data, BP_GET_PSIZE(bp)); 1591 } 1592 /* 1593 * If we are here to damage data for testing purposes, 1594 * leave the GBH alone so that we can detect the damage. 1595 */ 1596 if (pio->io_gang_leader->io_flags & ZIO_FLAG_INDUCE_DAMAGE) 1597 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 1598 } else { 1599 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1600 data, BP_GET_PSIZE(bp), NULL, NULL, pio->io_priority, 1601 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1602 } 1603 1604 return (zio); 1605 } 1606 1607 /* ARGSUSED */ 1608 zio_t * 1609 zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1610 { 1611 return (zio_free_sync(pio, pio->io_spa, pio->io_txg, bp, 1612 ZIO_GANG_CHILD_FLAGS(pio))); 1613 } 1614 1615 /* ARGSUSED */ 1616 zio_t * 1617 zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1618 { 1619 return (zio_claim(pio, pio->io_spa, pio->io_txg, bp, 1620 NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio))); 1621 } 1622 1623 static zio_gang_issue_func_t *zio_gang_issue_func[ZIO_TYPES] = { 1624 NULL, 1625 zio_read_gang, 1626 zio_rewrite_gang, 1627 zio_free_gang, 1628 zio_claim_gang, 1629 NULL 1630 }; 1631 1632 static void zio_gang_tree_assemble_done(zio_t *zio); 1633 1634 static zio_gang_node_t * 1635 zio_gang_node_alloc(zio_gang_node_t **gnpp) 1636 { 1637 zio_gang_node_t *gn; 1638 1639 ASSERT(*gnpp == NULL); 1640 1641 gn = kmem_zalloc(sizeof (*gn), KM_SLEEP); 1642 gn->gn_gbh = zio_buf_alloc(SPA_GANGBLOCKSIZE); 1643 *gnpp = gn; 1644 1645 return (gn); 1646 } 1647 1648 static void 1649 zio_gang_node_free(zio_gang_node_t **gnpp) 1650 { 1651 zio_gang_node_t *gn = *gnpp; 1652 1653 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 1654 ASSERT(gn->gn_child[g] == NULL); 1655 1656 zio_buf_free(gn->gn_gbh, SPA_GANGBLOCKSIZE); 1657 kmem_free(gn, sizeof (*gn)); 1658 *gnpp = NULL; 1659 } 1660 1661 static void 1662 zio_gang_tree_free(zio_gang_node_t **gnpp) 1663 { 1664 zio_gang_node_t *gn = *gnpp; 1665 1666 if (gn == NULL) 1667 return; 1668 1669 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 1670 zio_gang_tree_free(&gn->gn_child[g]); 1671 1672 zio_gang_node_free(gnpp); 1673 } 1674 1675 static void 1676 zio_gang_tree_assemble(zio_t *gio, blkptr_t *bp, zio_gang_node_t **gnpp) 1677 { 1678 zio_gang_node_t *gn = zio_gang_node_alloc(gnpp); 1679 1680 ASSERT(gio->io_gang_leader == gio); 1681 ASSERT(BP_IS_GANG(bp)); 1682 1683 zio_nowait(zio_read(gio, gio->io_spa, bp, gn->gn_gbh, 1684 SPA_GANGBLOCKSIZE, zio_gang_tree_assemble_done, gn, 1685 gio->io_priority, ZIO_GANG_CHILD_FLAGS(gio), &gio->io_bookmark)); 1686 } 1687 1688 static void 1689 zio_gang_tree_assemble_done(zio_t *zio) 1690 { 1691 zio_t *gio = zio->io_gang_leader; 1692 zio_gang_node_t *gn = zio->io_private; 1693 blkptr_t *bp = zio->io_bp; 1694 1695 ASSERT(gio == zio_unique_parent(zio)); 1696 ASSERT(zio->io_child_count == 0); 1697 1698 if (zio->io_error) 1699 return; 1700 1701 if (BP_SHOULD_BYTESWAP(bp)) 1702 byteswap_uint64_array(zio->io_data, zio->io_size); 1703 1704 ASSERT(zio->io_data == gn->gn_gbh); 1705 ASSERT(zio->io_size == SPA_GANGBLOCKSIZE); 1706 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 1707 1708 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 1709 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 1710 if (!BP_IS_GANG(gbp)) 1711 continue; 1712 zio_gang_tree_assemble(gio, gbp, &gn->gn_child[g]); 1713 } 1714 } 1715 1716 static void 1717 zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, void *data) 1718 { 1719 zio_t *gio = pio->io_gang_leader; 1720 zio_t *zio; 1721 1722 ASSERT(BP_IS_GANG(bp) == !!gn); 1723 ASSERT(BP_GET_CHECKSUM(bp) == BP_GET_CHECKSUM(gio->io_bp)); 1724 ASSERT(BP_GET_LSIZE(bp) == BP_GET_PSIZE(bp) || gn == gio->io_gang_tree); 1725 1726 /* 1727 * If you're a gang header, your data is in gn->gn_gbh. 1728 * If you're a gang member, your data is in 'data' and gn == NULL. 1729 */ 1730 zio = zio_gang_issue_func[gio->io_type](pio, bp, gn, data); 1731 1732 if (gn != NULL) { 1733 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 1734 1735 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 1736 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 1737 if (BP_IS_HOLE(gbp)) 1738 continue; 1739 zio_gang_tree_issue(zio, gn->gn_child[g], gbp, data); 1740 data = (char *)data + BP_GET_PSIZE(gbp); 1741 } 1742 } 1743 1744 if (gn == gio->io_gang_tree) 1745 ASSERT3P((char *)gio->io_data + gio->io_size, ==, data); 1746 1747 if (zio != pio) 1748 zio_nowait(zio); 1749 } 1750 1751 static int 1752 zio_gang_assemble(zio_t *zio) 1753 { 1754 blkptr_t *bp = zio->io_bp; 1755 1756 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == NULL); 1757 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 1758 1759 zio->io_gang_leader = zio; 1760 1761 zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree); 1762 1763 return (ZIO_PIPELINE_CONTINUE); 1764 } 1765 1766 static int 1767 zio_gang_issue(zio_t *zio) 1768 { 1769 blkptr_t *bp = zio->io_bp; 1770 1771 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE)) 1772 return (ZIO_PIPELINE_STOP); 1773 1774 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio); 1775 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 1776 1777 if (zio->io_child_error[ZIO_CHILD_GANG] == 0) 1778 zio_gang_tree_issue(zio, zio->io_gang_tree, bp, zio->io_data); 1779 else 1780 zio_gang_tree_free(&zio->io_gang_tree); 1781 1782 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1783 1784 return (ZIO_PIPELINE_CONTINUE); 1785 } 1786 1787 static void 1788 zio_write_gang_member_ready(zio_t *zio) 1789 { 1790 zio_t *pio = zio_unique_parent(zio); 1791 zio_t *gio = zio->io_gang_leader; 1792 dva_t *cdva = zio->io_bp->blk_dva; 1793 dva_t *pdva = pio->io_bp->blk_dva; 1794 uint64_t asize; 1795 1796 if (BP_IS_HOLE(zio->io_bp)) 1797 return; 1798 1799 ASSERT(BP_IS_HOLE(&zio->io_bp_orig)); 1800 1801 ASSERT(zio->io_child_type == ZIO_CHILD_GANG); 1802 ASSERT3U(zio->io_prop.zp_copies, ==, gio->io_prop.zp_copies); 1803 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp)); 1804 ASSERT3U(pio->io_prop.zp_copies, <=, BP_GET_NDVAS(pio->io_bp)); 1805 ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp)); 1806 1807 mutex_enter(&pio->io_lock); 1808 for (int d = 0; d < BP_GET_NDVAS(zio->io_bp); d++) { 1809 ASSERT(DVA_GET_GANG(&pdva[d])); 1810 asize = DVA_GET_ASIZE(&pdva[d]); 1811 asize += DVA_GET_ASIZE(&cdva[d]); 1812 DVA_SET_ASIZE(&pdva[d], asize); 1813 } 1814 mutex_exit(&pio->io_lock); 1815 } 1816 1817 static int 1818 zio_write_gang_block(zio_t *pio) 1819 { 1820 spa_t *spa = pio->io_spa; 1821 blkptr_t *bp = pio->io_bp; 1822 zio_t *gio = pio->io_gang_leader; 1823 zio_t *zio; 1824 zio_gang_node_t *gn, **gnpp; 1825 zio_gbh_phys_t *gbh; 1826 uint64_t txg = pio->io_txg; 1827 uint64_t resid = pio->io_size; 1828 uint64_t lsize; 1829 int copies = gio->io_prop.zp_copies; 1830 int gbh_copies = MIN(copies + 1, spa_max_replication(spa)); 1831 zio_prop_t zp; 1832 int error; 1833 1834 error = metaslab_alloc(spa, spa_normal_class(spa), SPA_GANGBLOCKSIZE, 1835 bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp, 1836 METASLAB_HINTBP_FAVOR | METASLAB_GANG_HEADER); 1837 if (error) { 1838 pio->io_error = error; 1839 return (ZIO_PIPELINE_CONTINUE); 1840 } 1841 1842 if (pio == gio) { 1843 gnpp = &gio->io_gang_tree; 1844 } else { 1845 gnpp = pio->io_private; 1846 ASSERT(pio->io_ready == zio_write_gang_member_ready); 1847 } 1848 1849 gn = zio_gang_node_alloc(gnpp); 1850 gbh = gn->gn_gbh; 1851 bzero(gbh, SPA_GANGBLOCKSIZE); 1852 1853 /* 1854 * Create the gang header. 1855 */ 1856 zio = zio_rewrite(pio, spa, txg, bp, gbh, SPA_GANGBLOCKSIZE, NULL, NULL, 1857 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1858 1859 /* 1860 * Create and nowait the gang children. 1861 */ 1862 for (int g = 0; resid != 0; resid -= lsize, g++) { 1863 lsize = P2ROUNDUP(resid / (SPA_GBH_NBLKPTRS - g), 1864 SPA_MINBLOCKSIZE); 1865 ASSERT(lsize >= SPA_MINBLOCKSIZE && lsize <= resid); 1866 1867 zp.zp_checksum = gio->io_prop.zp_checksum; 1868 zp.zp_compress = ZIO_COMPRESS_OFF; 1869 zp.zp_type = DMU_OT_NONE; 1870 zp.zp_level = 0; 1871 zp.zp_copies = gio->io_prop.zp_copies; 1872 zp.zp_dedup = B_FALSE; 1873 zp.zp_dedup_verify = B_FALSE; 1874 zp.zp_nopwrite = B_FALSE; 1875 1876 zio_nowait(zio_write(zio, spa, txg, &gbh->zg_blkptr[g], 1877 (char *)pio->io_data + (pio->io_size - resid), lsize, &zp, 1878 zio_write_gang_member_ready, NULL, NULL, &gn->gn_child[g], 1879 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 1880 &pio->io_bookmark)); 1881 } 1882 1883 /* 1884 * Set pio's pipeline to just wait for zio to finish. 1885 */ 1886 pio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1887 1888 zio_nowait(zio); 1889 1890 return (ZIO_PIPELINE_CONTINUE); 1891 } 1892 1893 /* 1894 * The zio_nop_write stage in the pipeline determines if allocating 1895 * a new bp is necessary. By leveraging a cryptographically secure checksum, 1896 * such as SHA256, we can compare the checksums of the new data and the old 1897 * to determine if allocating a new block is required. The nopwrite 1898 * feature can handle writes in either syncing or open context (i.e. zil 1899 * writes) and as a result is mutually exclusive with dedup. 1900 */ 1901 static int 1902 zio_nop_write(zio_t *zio) 1903 { 1904 blkptr_t *bp = zio->io_bp; 1905 blkptr_t *bp_orig = &zio->io_bp_orig; 1906 zio_prop_t *zp = &zio->io_prop; 1907 1908 ASSERT(BP_GET_LEVEL(bp) == 0); 1909 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1910 ASSERT(zp->zp_nopwrite); 1911 ASSERT(!zp->zp_dedup); 1912 ASSERT(zio->io_bp_override == NULL); 1913 ASSERT(IO_IS_ALLOCATING(zio)); 1914 1915 /* 1916 * Check to see if the original bp and the new bp have matching 1917 * characteristics (i.e. same checksum, compression algorithms, etc). 1918 * If they don't then just continue with the pipeline which will 1919 * allocate a new bp. 1920 */ 1921 if (BP_IS_HOLE(bp_orig) || 1922 !zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_dedup || 1923 BP_GET_CHECKSUM(bp) != BP_GET_CHECKSUM(bp_orig) || 1924 BP_GET_COMPRESS(bp) != BP_GET_COMPRESS(bp_orig) || 1925 BP_GET_DEDUP(bp) != BP_GET_DEDUP(bp_orig) || 1926 zp->zp_copies != BP_GET_NDVAS(bp_orig)) 1927 return (ZIO_PIPELINE_CONTINUE); 1928 1929 /* 1930 * If the checksums match then reset the pipeline so that we 1931 * avoid allocating a new bp and issuing any I/O. 1932 */ 1933 if (ZIO_CHECKSUM_EQUAL(bp->blk_cksum, bp_orig->blk_cksum)) { 1934 ASSERT(zio_checksum_table[zp->zp_checksum].ci_dedup); 1935 ASSERT3U(BP_GET_PSIZE(bp), ==, BP_GET_PSIZE(bp_orig)); 1936 ASSERT3U(BP_GET_LSIZE(bp), ==, BP_GET_LSIZE(bp_orig)); 1937 ASSERT(zp->zp_compress != ZIO_COMPRESS_OFF); 1938 ASSERT(bcmp(&bp->blk_prop, &bp_orig->blk_prop, 1939 sizeof (uint64_t)) == 0); 1940 1941 *bp = *bp_orig; 1942 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1943 zio->io_flags |= ZIO_FLAG_NOPWRITE; 1944 } 1945 1946 return (ZIO_PIPELINE_CONTINUE); 1947 } 1948 1949 /* 1950 * ========================================================================== 1951 * Dedup 1952 * ========================================================================== 1953 */ 1954 static void 1955 zio_ddt_child_read_done(zio_t *zio) 1956 { 1957 blkptr_t *bp = zio->io_bp; 1958 ddt_entry_t *dde = zio->io_private; 1959 ddt_phys_t *ddp; 1960 zio_t *pio = zio_unique_parent(zio); 1961 1962 mutex_enter(&pio->io_lock); 1963 ddp = ddt_phys_select(dde, bp); 1964 if (zio->io_error == 0) 1965 ddt_phys_clear(ddp); /* this ddp doesn't need repair */ 1966 if (zio->io_error == 0 && dde->dde_repair_data == NULL) 1967 dde->dde_repair_data = zio->io_data; 1968 else 1969 zio_buf_free(zio->io_data, zio->io_size); 1970 mutex_exit(&pio->io_lock); 1971 } 1972 1973 static int 1974 zio_ddt_read_start(zio_t *zio) 1975 { 1976 blkptr_t *bp = zio->io_bp; 1977 1978 ASSERT(BP_GET_DEDUP(bp)); 1979 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 1980 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1981 1982 if (zio->io_child_error[ZIO_CHILD_DDT]) { 1983 ddt_t *ddt = ddt_select(zio->io_spa, bp); 1984 ddt_entry_t *dde = ddt_repair_start(ddt, bp); 1985 ddt_phys_t *ddp = dde->dde_phys; 1986 ddt_phys_t *ddp_self = ddt_phys_select(dde, bp); 1987 blkptr_t blk; 1988 1989 ASSERT(zio->io_vsd == NULL); 1990 zio->io_vsd = dde; 1991 1992 if (ddp_self == NULL) 1993 return (ZIO_PIPELINE_CONTINUE); 1994 1995 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { 1996 if (ddp->ddp_phys_birth == 0 || ddp == ddp_self) 1997 continue; 1998 ddt_bp_create(ddt->ddt_checksum, &dde->dde_key, ddp, 1999 &blk); 2000 zio_nowait(zio_read(zio, zio->io_spa, &blk, 2001 zio_buf_alloc(zio->io_size), zio->io_size, 2002 zio_ddt_child_read_done, dde, zio->io_priority, 2003 ZIO_DDT_CHILD_FLAGS(zio) | ZIO_FLAG_DONT_PROPAGATE, 2004 &zio->io_bookmark)); 2005 } 2006 return (ZIO_PIPELINE_CONTINUE); 2007 } 2008 2009 zio_nowait(zio_read(zio, zio->io_spa, bp, 2010 zio->io_data, zio->io_size, NULL, NULL, zio->io_priority, 2011 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark)); 2012 2013 return (ZIO_PIPELINE_CONTINUE); 2014 } 2015 2016 static int 2017 zio_ddt_read_done(zio_t *zio) 2018 { 2019 blkptr_t *bp = zio->io_bp; 2020 2021 if (zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE)) 2022 return (ZIO_PIPELINE_STOP); 2023 2024 ASSERT(BP_GET_DEDUP(bp)); 2025 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 2026 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2027 2028 if (zio->io_child_error[ZIO_CHILD_DDT]) { 2029 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2030 ddt_entry_t *dde = zio->io_vsd; 2031 if (ddt == NULL) { 2032 ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE); 2033 return (ZIO_PIPELINE_CONTINUE); 2034 } 2035 if (dde == NULL) { 2036 zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1; 2037 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 2038 return (ZIO_PIPELINE_STOP); 2039 } 2040 if (dde->dde_repair_data != NULL) { 2041 bcopy(dde->dde_repair_data, zio->io_data, zio->io_size); 2042 zio->io_child_error[ZIO_CHILD_DDT] = 0; 2043 } 2044 ddt_repair_done(ddt, dde); 2045 zio->io_vsd = NULL; 2046 } 2047 2048 ASSERT(zio->io_vsd == NULL); 2049 2050 return (ZIO_PIPELINE_CONTINUE); 2051 } 2052 2053 static boolean_t 2054 zio_ddt_collision(zio_t *zio, ddt_t *ddt, ddt_entry_t *dde) 2055 { 2056 spa_t *spa = zio->io_spa; 2057 2058 /* 2059 * Note: we compare the original data, not the transformed data, 2060 * because when zio->io_bp is an override bp, we will not have 2061 * pushed the I/O transforms. That's an important optimization 2062 * because otherwise we'd compress/encrypt all dmu_sync() data twice. 2063 */ 2064 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 2065 zio_t *lio = dde->dde_lead_zio[p]; 2066 2067 if (lio != NULL) { 2068 return (lio->io_orig_size != zio->io_orig_size || 2069 bcmp(zio->io_orig_data, lio->io_orig_data, 2070 zio->io_orig_size) != 0); 2071 } 2072 } 2073 2074 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 2075 ddt_phys_t *ddp = &dde->dde_phys[p]; 2076 2077 if (ddp->ddp_phys_birth != 0) { 2078 arc_buf_t *abuf = NULL; 2079 uint32_t aflags = ARC_WAIT; 2080 blkptr_t blk = *zio->io_bp; 2081 int error; 2082 2083 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth); 2084 2085 ddt_exit(ddt); 2086 2087 error = arc_read(NULL, spa, &blk, 2088 arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ, 2089 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, 2090 &aflags, &zio->io_bookmark); 2091 2092 if (error == 0) { 2093 if (arc_buf_size(abuf) != zio->io_orig_size || 2094 bcmp(abuf->b_data, zio->io_orig_data, 2095 zio->io_orig_size) != 0) 2096 error = SET_ERROR(EEXIST); 2097 VERIFY(arc_buf_remove_ref(abuf, &abuf)); 2098 } 2099 2100 ddt_enter(ddt); 2101 return (error != 0); 2102 } 2103 } 2104 2105 return (B_FALSE); 2106 } 2107 2108 static void 2109 zio_ddt_child_write_ready(zio_t *zio) 2110 { 2111 int p = zio->io_prop.zp_copies; 2112 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 2113 ddt_entry_t *dde = zio->io_private; 2114 ddt_phys_t *ddp = &dde->dde_phys[p]; 2115 zio_t *pio; 2116 2117 if (zio->io_error) 2118 return; 2119 2120 ddt_enter(ddt); 2121 2122 ASSERT(dde->dde_lead_zio[p] == zio); 2123 2124 ddt_phys_fill(ddp, zio->io_bp); 2125 2126 while ((pio = zio_walk_parents(zio)) != NULL) 2127 ddt_bp_fill(ddp, pio->io_bp, zio->io_txg); 2128 2129 ddt_exit(ddt); 2130 } 2131 2132 static void 2133 zio_ddt_child_write_done(zio_t *zio) 2134 { 2135 int p = zio->io_prop.zp_copies; 2136 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 2137 ddt_entry_t *dde = zio->io_private; 2138 ddt_phys_t *ddp = &dde->dde_phys[p]; 2139 2140 ddt_enter(ddt); 2141 2142 ASSERT(ddp->ddp_refcnt == 0); 2143 ASSERT(dde->dde_lead_zio[p] == zio); 2144 dde->dde_lead_zio[p] = NULL; 2145 2146 if (zio->io_error == 0) { 2147 while (zio_walk_parents(zio) != NULL) 2148 ddt_phys_addref(ddp); 2149 } else { 2150 ddt_phys_clear(ddp); 2151 } 2152 2153 ddt_exit(ddt); 2154 } 2155 2156 static void 2157 zio_ddt_ditto_write_done(zio_t *zio) 2158 { 2159 int p = DDT_PHYS_DITTO; 2160 zio_prop_t *zp = &zio->io_prop; 2161 blkptr_t *bp = zio->io_bp; 2162 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2163 ddt_entry_t *dde = zio->io_private; 2164 ddt_phys_t *ddp = &dde->dde_phys[p]; 2165 ddt_key_t *ddk = &dde->dde_key; 2166 2167 ddt_enter(ddt); 2168 2169 ASSERT(ddp->ddp_refcnt == 0); 2170 ASSERT(dde->dde_lead_zio[p] == zio); 2171 dde->dde_lead_zio[p] = NULL; 2172 2173 if (zio->io_error == 0) { 2174 ASSERT(ZIO_CHECKSUM_EQUAL(bp->blk_cksum, ddk->ddk_cksum)); 2175 ASSERT(zp->zp_copies < SPA_DVAS_PER_BP); 2176 ASSERT(zp->zp_copies == BP_GET_NDVAS(bp) - BP_IS_GANG(bp)); 2177 if (ddp->ddp_phys_birth != 0) 2178 ddt_phys_free(ddt, ddk, ddp, zio->io_txg); 2179 ddt_phys_fill(ddp, bp); 2180 } 2181 2182 ddt_exit(ddt); 2183 } 2184 2185 static int 2186 zio_ddt_write(zio_t *zio) 2187 { 2188 spa_t *spa = zio->io_spa; 2189 blkptr_t *bp = zio->io_bp; 2190 uint64_t txg = zio->io_txg; 2191 zio_prop_t *zp = &zio->io_prop; 2192 int p = zp->zp_copies; 2193 int ditto_copies; 2194 zio_t *cio = NULL; 2195 zio_t *dio = NULL; 2196 ddt_t *ddt = ddt_select(spa, bp); 2197 ddt_entry_t *dde; 2198 ddt_phys_t *ddp; 2199 2200 ASSERT(BP_GET_DEDUP(bp)); 2201 ASSERT(BP_GET_CHECKSUM(bp) == zp->zp_checksum); 2202 ASSERT(BP_IS_HOLE(bp) || zio->io_bp_override); 2203 2204 ddt_enter(ddt); 2205 dde = ddt_lookup(ddt, bp, B_TRUE); 2206 ddp = &dde->dde_phys[p]; 2207 2208 if (zp->zp_dedup_verify && zio_ddt_collision(zio, ddt, dde)) { 2209 /* 2210 * If we're using a weak checksum, upgrade to a strong checksum 2211 * and try again. If we're already using a strong checksum, 2212 * we can't resolve it, so just convert to an ordinary write. 2213 * (And automatically e-mail a paper to Nature?) 2214 */ 2215 if (!zio_checksum_table[zp->zp_checksum].ci_dedup) { 2216 zp->zp_checksum = spa_dedup_checksum(spa); 2217 zio_pop_transforms(zio); 2218 zio->io_stage = ZIO_STAGE_OPEN; 2219 BP_ZERO(bp); 2220 } else { 2221 zp->zp_dedup = B_FALSE; 2222 } 2223 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2224 ddt_exit(ddt); 2225 return (ZIO_PIPELINE_CONTINUE); 2226 } 2227 2228 ditto_copies = ddt_ditto_copies_needed(ddt, dde, ddp); 2229 ASSERT(ditto_copies < SPA_DVAS_PER_BP); 2230 2231 if (ditto_copies > ddt_ditto_copies_present(dde) && 2232 dde->dde_lead_zio[DDT_PHYS_DITTO] == NULL) { 2233 zio_prop_t czp = *zp; 2234 2235 czp.zp_copies = ditto_copies; 2236 2237 /* 2238 * If we arrived here with an override bp, we won't have run 2239 * the transform stack, so we won't have the data we need to 2240 * generate a child i/o. So, toss the override bp and restart. 2241 * This is safe, because using the override bp is just an 2242 * optimization; and it's rare, so the cost doesn't matter. 2243 */ 2244 if (zio->io_bp_override) { 2245 zio_pop_transforms(zio); 2246 zio->io_stage = ZIO_STAGE_OPEN; 2247 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2248 zio->io_bp_override = NULL; 2249 BP_ZERO(bp); 2250 ddt_exit(ddt); 2251 return (ZIO_PIPELINE_CONTINUE); 2252 } 2253 2254 dio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2255 zio->io_orig_size, &czp, NULL, NULL, 2256 zio_ddt_ditto_write_done, dde, zio->io_priority, 2257 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2258 2259 zio_push_transform(dio, zio->io_data, zio->io_size, 0, NULL); 2260 dde->dde_lead_zio[DDT_PHYS_DITTO] = dio; 2261 } 2262 2263 if (ddp->ddp_phys_birth != 0 || dde->dde_lead_zio[p] != NULL) { 2264 if (ddp->ddp_phys_birth != 0) 2265 ddt_bp_fill(ddp, bp, txg); 2266 if (dde->dde_lead_zio[p] != NULL) 2267 zio_add_child(zio, dde->dde_lead_zio[p]); 2268 else 2269 ddt_phys_addref(ddp); 2270 } else if (zio->io_bp_override) { 2271 ASSERT(bp->blk_birth == txg); 2272 ASSERT(BP_EQUAL(bp, zio->io_bp_override)); 2273 ddt_phys_fill(ddp, bp); 2274 ddt_phys_addref(ddp); 2275 } else { 2276 cio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2277 zio->io_orig_size, zp, zio_ddt_child_write_ready, NULL, 2278 zio_ddt_child_write_done, dde, zio->io_priority, 2279 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2280 2281 zio_push_transform(cio, zio->io_data, zio->io_size, 0, NULL); 2282 dde->dde_lead_zio[p] = cio; 2283 } 2284 2285 ddt_exit(ddt); 2286 2287 if (cio) 2288 zio_nowait(cio); 2289 if (dio) 2290 zio_nowait(dio); 2291 2292 return (ZIO_PIPELINE_CONTINUE); 2293 } 2294 2295 ddt_entry_t *freedde; /* for debugging */ 2296 2297 static int 2298 zio_ddt_free(zio_t *zio) 2299 { 2300 spa_t *spa = zio->io_spa; 2301 blkptr_t *bp = zio->io_bp; 2302 ddt_t *ddt = ddt_select(spa, bp); 2303 ddt_entry_t *dde; 2304 ddt_phys_t *ddp; 2305 2306 ASSERT(BP_GET_DEDUP(bp)); 2307 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2308 2309 ddt_enter(ddt); 2310 freedde = dde = ddt_lookup(ddt, bp, B_TRUE); 2311 ddp = ddt_phys_select(dde, bp); 2312 ddt_phys_decref(ddp); 2313 ddt_exit(ddt); 2314 2315 return (ZIO_PIPELINE_CONTINUE); 2316 } 2317 2318 /* 2319 * ========================================================================== 2320 * Allocate and free blocks 2321 * ========================================================================== 2322 */ 2323 static int 2324 zio_dva_allocate(zio_t *zio) 2325 { 2326 spa_t *spa = zio->io_spa; 2327 metaslab_class_t *mc = spa_normal_class(spa); 2328 blkptr_t *bp = zio->io_bp; 2329 int error; 2330 int flags = 0; 2331 2332 if (zio->io_gang_leader == NULL) { 2333 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2334 zio->io_gang_leader = zio; 2335 } 2336 2337 ASSERT(BP_IS_HOLE(bp)); 2338 ASSERT0(BP_GET_NDVAS(bp)); 2339 ASSERT3U(zio->io_prop.zp_copies, >, 0); 2340 ASSERT3U(zio->io_prop.zp_copies, <=, spa_max_replication(spa)); 2341 ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp)); 2342 2343 /* 2344 * The dump device does not support gang blocks so allocation on 2345 * behalf of the dump device (i.e. ZIO_FLAG_NODATA) must avoid 2346 * the "fast" gang feature. 2347 */ 2348 flags |= (zio->io_flags & ZIO_FLAG_NODATA) ? METASLAB_GANG_AVOID : 0; 2349 flags |= (zio->io_flags & ZIO_FLAG_GANG_CHILD) ? 2350 METASLAB_GANG_CHILD : 0; 2351 error = metaslab_alloc(spa, mc, zio->io_size, bp, 2352 zio->io_prop.zp_copies, zio->io_txg, NULL, flags); 2353 2354 if (error) { 2355 spa_dbgmsg(spa, "%s: metaslab allocation failure: zio %p, " 2356 "size %llu, error %d", spa_name(spa), zio, zio->io_size, 2357 error); 2358 if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE) 2359 return (zio_write_gang_block(zio)); 2360 zio->io_error = error; 2361 } 2362 2363 return (ZIO_PIPELINE_CONTINUE); 2364 } 2365 2366 static int 2367 zio_dva_free(zio_t *zio) 2368 { 2369 metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE); 2370 2371 return (ZIO_PIPELINE_CONTINUE); 2372 } 2373 2374 static int 2375 zio_dva_claim(zio_t *zio) 2376 { 2377 int error; 2378 2379 error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg); 2380 if (error) 2381 zio->io_error = error; 2382 2383 return (ZIO_PIPELINE_CONTINUE); 2384 } 2385 2386 /* 2387 * Undo an allocation. This is used by zio_done() when an I/O fails 2388 * and we want to give back the block we just allocated. 2389 * This handles both normal blocks and gang blocks. 2390 */ 2391 static void 2392 zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp) 2393 { 2394 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp)); 2395 ASSERT(zio->io_bp_override == NULL); 2396 2397 if (!BP_IS_HOLE(bp)) 2398 metaslab_free(zio->io_spa, bp, bp->blk_birth, B_TRUE); 2399 2400 if (gn != NULL) { 2401 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 2402 zio_dva_unallocate(zio, gn->gn_child[g], 2403 &gn->gn_gbh->zg_blkptr[g]); 2404 } 2405 } 2406 } 2407 2408 /* 2409 * Try to allocate an intent log block. Return 0 on success, errno on failure. 2410 */ 2411 int 2412 zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp, blkptr_t *old_bp, 2413 uint64_t size, boolean_t use_slog) 2414 { 2415 int error = 1; 2416 2417 ASSERT(txg > spa_syncing_txg(spa)); 2418 2419 /* 2420 * ZIL blocks are always contiguous (i.e. not gang blocks) so we 2421 * set the METASLAB_GANG_AVOID flag so that they don't "fast gang" 2422 * when allocating them. 2423 */ 2424 if (use_slog) { 2425 error = metaslab_alloc(spa, spa_log_class(spa), size, 2426 new_bp, 1, txg, old_bp, 2427 METASLAB_HINTBP_AVOID | METASLAB_GANG_AVOID); 2428 } 2429 2430 if (error) { 2431 error = metaslab_alloc(spa, spa_normal_class(spa), size, 2432 new_bp, 1, txg, old_bp, 2433 METASLAB_HINTBP_AVOID); 2434 } 2435 2436 if (error == 0) { 2437 BP_SET_LSIZE(new_bp, size); 2438 BP_SET_PSIZE(new_bp, size); 2439 BP_SET_COMPRESS(new_bp, ZIO_COMPRESS_OFF); 2440 BP_SET_CHECKSUM(new_bp, 2441 spa_version(spa) >= SPA_VERSION_SLIM_ZIL 2442 ? ZIO_CHECKSUM_ZILOG2 : ZIO_CHECKSUM_ZILOG); 2443 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG); 2444 BP_SET_LEVEL(new_bp, 0); 2445 BP_SET_DEDUP(new_bp, 0); 2446 BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER); 2447 } 2448 2449 return (error); 2450 } 2451 2452 /* 2453 * Free an intent log block. 2454 */ 2455 void 2456 zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp) 2457 { 2458 ASSERT(BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG); 2459 ASSERT(!BP_IS_GANG(bp)); 2460 2461 zio_free(spa, txg, bp); 2462 } 2463 2464 /* 2465 * ========================================================================== 2466 * Read and write to physical devices 2467 * ========================================================================== 2468 */ 2469 static int 2470 zio_vdev_io_start(zio_t *zio) 2471 { 2472 vdev_t *vd = zio->io_vd; 2473 uint64_t align; 2474 spa_t *spa = zio->io_spa; 2475 2476 ASSERT(zio->io_error == 0); 2477 ASSERT(zio->io_child_error[ZIO_CHILD_VDEV] == 0); 2478 2479 if (vd == NULL) { 2480 if (!(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 2481 spa_config_enter(spa, SCL_ZIO, zio, RW_READER); 2482 2483 /* 2484 * The mirror_ops handle multiple DVAs in a single BP. 2485 */ 2486 return (vdev_mirror_ops.vdev_op_io_start(zio)); 2487 } 2488 2489 /* 2490 * We keep track of time-sensitive I/Os so that the scan thread 2491 * can quickly react to certain workloads. In particular, we care 2492 * about non-scrubbing, top-level reads and writes with the following 2493 * characteristics: 2494 * - synchronous writes of user data to non-slog devices 2495 * - any reads of user data 2496 * When these conditions are met, adjust the timestamp of spa_last_io 2497 * which allows the scan thread to adjust its workload accordingly. 2498 */ 2499 if (!(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && zio->io_bp != NULL && 2500 vd == vd->vdev_top && !vd->vdev_islog && 2501 zio->io_bookmark.zb_objset != DMU_META_OBJSET && 2502 zio->io_txg != spa_syncing_txg(spa)) { 2503 uint64_t old = spa->spa_last_io; 2504 uint64_t new = ddi_get_lbolt64(); 2505 if (old != new) 2506 (void) atomic_cas_64(&spa->spa_last_io, old, new); 2507 } 2508 2509 align = 1ULL << vd->vdev_top->vdev_ashift; 2510 2511 if (P2PHASE(zio->io_size, align) != 0) { 2512 uint64_t asize = P2ROUNDUP(zio->io_size, align); 2513 char *abuf = zio_buf_alloc(asize); 2514 ASSERT(vd == vd->vdev_top); 2515 if (zio->io_type == ZIO_TYPE_WRITE) { 2516 bcopy(zio->io_data, abuf, zio->io_size); 2517 bzero(abuf + zio->io_size, asize - zio->io_size); 2518 } 2519 zio_push_transform(zio, abuf, asize, asize, zio_subblock); 2520 } 2521 2522 ASSERT(P2PHASE(zio->io_offset, align) == 0); 2523 ASSERT(P2PHASE(zio->io_size, align) == 0); 2524 VERIFY(zio->io_type != ZIO_TYPE_WRITE || spa_writeable(spa)); 2525 2526 /* 2527 * If this is a repair I/O, and there's no self-healing involved -- 2528 * that is, we're just resilvering what we expect to resilver -- 2529 * then don't do the I/O unless zio's txg is actually in vd's DTL. 2530 * This prevents spurious resilvering with nested replication. 2531 * For example, given a mirror of mirrors, (A+B)+(C+D), if only 2532 * A is out of date, we'll read from C+D, then use the data to 2533 * resilver A+B -- but we don't actually want to resilver B, just A. 2534 * The top-level mirror has no way to know this, so instead we just 2535 * discard unnecessary repairs as we work our way down the vdev tree. 2536 * The same logic applies to any form of nested replication: 2537 * ditto + mirror, RAID-Z + replacing, etc. This covers them all. 2538 */ 2539 if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) && 2540 !(zio->io_flags & ZIO_FLAG_SELF_HEAL) && 2541 zio->io_txg != 0 && /* not a delegated i/o */ 2542 !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) { 2543 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 2544 zio_vdev_io_bypass(zio); 2545 return (ZIO_PIPELINE_CONTINUE); 2546 } 2547 2548 if (vd->vdev_ops->vdev_op_leaf && 2549 (zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE)) { 2550 2551 if (zio->io_type == ZIO_TYPE_READ && vdev_cache_read(zio)) 2552 return (ZIO_PIPELINE_CONTINUE); 2553 2554 if ((zio = vdev_queue_io(zio)) == NULL) 2555 return (ZIO_PIPELINE_STOP); 2556 2557 if (!vdev_accessible(vd, zio)) { 2558 zio->io_error = SET_ERROR(ENXIO); 2559 zio_interrupt(zio); 2560 return (ZIO_PIPELINE_STOP); 2561 } 2562 } 2563 2564 return (vd->vdev_ops->vdev_op_io_start(zio)); 2565 } 2566 2567 static int 2568 zio_vdev_io_done(zio_t *zio) 2569 { 2570 vdev_t *vd = zio->io_vd; 2571 vdev_ops_t *ops = vd ? vd->vdev_ops : &vdev_mirror_ops; 2572 boolean_t unexpected_error = B_FALSE; 2573 2574 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 2575 return (ZIO_PIPELINE_STOP); 2576 2577 ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE); 2578 2579 if (vd != NULL && vd->vdev_ops->vdev_op_leaf) { 2580 2581 vdev_queue_io_done(zio); 2582 2583 if (zio->io_type == ZIO_TYPE_WRITE) 2584 vdev_cache_write(zio); 2585 2586 if (zio_injection_enabled && zio->io_error == 0) 2587 zio->io_error = zio_handle_device_injection(vd, 2588 zio, EIO); 2589 2590 if (zio_injection_enabled && zio->io_error == 0) 2591 zio->io_error = zio_handle_label_injection(zio, EIO); 2592 2593 if (zio->io_error) { 2594 if (!vdev_accessible(vd, zio)) { 2595 zio->io_error = SET_ERROR(ENXIO); 2596 } else { 2597 unexpected_error = B_TRUE; 2598 } 2599 } 2600 } 2601 2602 ops->vdev_op_io_done(zio); 2603 2604 if (unexpected_error) 2605 VERIFY(vdev_probe(vd, zio) == NULL); 2606 2607 return (ZIO_PIPELINE_CONTINUE); 2608 } 2609 2610 /* 2611 * For non-raidz ZIOs, we can just copy aside the bad data read from the 2612 * disk, and use that to finish the checksum ereport later. 2613 */ 2614 static void 2615 zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr, 2616 const void *good_buf) 2617 { 2618 /* no processing needed */ 2619 zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE); 2620 } 2621 2622 /*ARGSUSED*/ 2623 void 2624 zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *ignored) 2625 { 2626 void *buf = zio_buf_alloc(zio->io_size); 2627 2628 bcopy(zio->io_data, buf, zio->io_size); 2629 2630 zcr->zcr_cbinfo = zio->io_size; 2631 zcr->zcr_cbdata = buf; 2632 zcr->zcr_finish = zio_vsd_default_cksum_finish; 2633 zcr->zcr_free = zio_buf_free; 2634 } 2635 2636 static int 2637 zio_vdev_io_assess(zio_t *zio) 2638 { 2639 vdev_t *vd = zio->io_vd; 2640 2641 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 2642 return (ZIO_PIPELINE_STOP); 2643 2644 if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 2645 spa_config_exit(zio->io_spa, SCL_ZIO, zio); 2646 2647 if (zio->io_vsd != NULL) { 2648 zio->io_vsd_ops->vsd_free(zio); 2649 zio->io_vsd = NULL; 2650 } 2651 2652 if (zio_injection_enabled && zio->io_error == 0) 2653 zio->io_error = zio_handle_fault_injection(zio, EIO); 2654 2655 /* 2656 * If the I/O failed, determine whether we should attempt to retry it. 2657 * 2658 * On retry, we cut in line in the issue queue, since we don't want 2659 * compression/checksumming/etc. work to prevent our (cheap) IO reissue. 2660 */ 2661 if (zio->io_error && vd == NULL && 2662 !(zio->io_flags & (ZIO_FLAG_DONT_RETRY | ZIO_FLAG_IO_RETRY))) { 2663 ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_QUEUE)); /* not a leaf */ 2664 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_BYPASS)); /* not a leaf */ 2665 zio->io_error = 0; 2666 zio->io_flags |= ZIO_FLAG_IO_RETRY | 2667 ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE; 2668 zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1; 2669 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, 2670 zio_requeue_io_start_cut_in_line); 2671 return (ZIO_PIPELINE_STOP); 2672 } 2673 2674 /* 2675 * If we got an error on a leaf device, convert it to ENXIO 2676 * if the device is not accessible at all. 2677 */ 2678 if (zio->io_error && vd != NULL && vd->vdev_ops->vdev_op_leaf && 2679 !vdev_accessible(vd, zio)) 2680 zio->io_error = SET_ERROR(ENXIO); 2681 2682 /* 2683 * If we can't write to an interior vdev (mirror or RAID-Z), 2684 * set vdev_cant_write so that we stop trying to allocate from it. 2685 */ 2686 if (zio->io_error == ENXIO && zio->io_type == ZIO_TYPE_WRITE && 2687 vd != NULL && !vd->vdev_ops->vdev_op_leaf) { 2688 vd->vdev_cant_write = B_TRUE; 2689 } 2690 2691 if (zio->io_error) 2692 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2693 2694 if (vd != NULL && vd->vdev_ops->vdev_op_leaf && 2695 zio->io_physdone != NULL) { 2696 ASSERT(!(zio->io_flags & ZIO_FLAG_DELEGATED)); 2697 ASSERT(zio->io_child_type == ZIO_CHILD_VDEV); 2698 zio->io_physdone(zio->io_logical); 2699 } 2700 2701 return (ZIO_PIPELINE_CONTINUE); 2702 } 2703 2704 void 2705 zio_vdev_io_reissue(zio_t *zio) 2706 { 2707 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 2708 ASSERT(zio->io_error == 0); 2709 2710 zio->io_stage >>= 1; 2711 } 2712 2713 void 2714 zio_vdev_io_redone(zio_t *zio) 2715 { 2716 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE); 2717 2718 zio->io_stage >>= 1; 2719 } 2720 2721 void 2722 zio_vdev_io_bypass(zio_t *zio) 2723 { 2724 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 2725 ASSERT(zio->io_error == 0); 2726 2727 zio->io_flags |= ZIO_FLAG_IO_BYPASS; 2728 zio->io_stage = ZIO_STAGE_VDEV_IO_ASSESS >> 1; 2729 } 2730 2731 /* 2732 * ========================================================================== 2733 * Generate and verify checksums 2734 * ========================================================================== 2735 */ 2736 static int 2737 zio_checksum_generate(zio_t *zio) 2738 { 2739 blkptr_t *bp = zio->io_bp; 2740 enum zio_checksum checksum; 2741 2742 if (bp == NULL) { 2743 /* 2744 * This is zio_write_phys(). 2745 * We're either generating a label checksum, or none at all. 2746 */ 2747 checksum = zio->io_prop.zp_checksum; 2748 2749 if (checksum == ZIO_CHECKSUM_OFF) 2750 return (ZIO_PIPELINE_CONTINUE); 2751 2752 ASSERT(checksum == ZIO_CHECKSUM_LABEL); 2753 } else { 2754 if (BP_IS_GANG(bp) && zio->io_child_type == ZIO_CHILD_GANG) { 2755 ASSERT(!IO_IS_ALLOCATING(zio)); 2756 checksum = ZIO_CHECKSUM_GANG_HEADER; 2757 } else { 2758 checksum = BP_GET_CHECKSUM(bp); 2759 } 2760 } 2761 2762 zio_checksum_compute(zio, checksum, zio->io_data, zio->io_size); 2763 2764 return (ZIO_PIPELINE_CONTINUE); 2765 } 2766 2767 static int 2768 zio_checksum_verify(zio_t *zio) 2769 { 2770 zio_bad_cksum_t info; 2771 blkptr_t *bp = zio->io_bp; 2772 int error; 2773 2774 ASSERT(zio->io_vd != NULL); 2775 2776 if (bp == NULL) { 2777 /* 2778 * This is zio_read_phys(). 2779 * We're either verifying a label checksum, or nothing at all. 2780 */ 2781 if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF) 2782 return (ZIO_PIPELINE_CONTINUE); 2783 2784 ASSERT(zio->io_prop.zp_checksum == ZIO_CHECKSUM_LABEL); 2785 } 2786 2787 if ((error = zio_checksum_error(zio, &info)) != 0) { 2788 zio->io_error = error; 2789 if (!(zio->io_flags & ZIO_FLAG_SPECULATIVE)) { 2790 zfs_ereport_start_checksum(zio->io_spa, 2791 zio->io_vd, zio, zio->io_offset, 2792 zio->io_size, NULL, &info); 2793 } 2794 } 2795 2796 return (ZIO_PIPELINE_CONTINUE); 2797 } 2798 2799 /* 2800 * Called by RAID-Z to ensure we don't compute the checksum twice. 2801 */ 2802 void 2803 zio_checksum_verified(zio_t *zio) 2804 { 2805 zio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 2806 } 2807 2808 /* 2809 * ========================================================================== 2810 * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other. 2811 * An error of 0 indicates success. ENXIO indicates whole-device failure, 2812 * which may be transient (e.g. unplugged) or permament. ECKSUM and EIO 2813 * indicate errors that are specific to one I/O, and most likely permanent. 2814 * Any other error is presumed to be worse because we weren't expecting it. 2815 * ========================================================================== 2816 */ 2817 int 2818 zio_worst_error(int e1, int e2) 2819 { 2820 static int zio_error_rank[] = { 0, ENXIO, ECKSUM, EIO }; 2821 int r1, r2; 2822 2823 for (r1 = 0; r1 < sizeof (zio_error_rank) / sizeof (int); r1++) 2824 if (e1 == zio_error_rank[r1]) 2825 break; 2826 2827 for (r2 = 0; r2 < sizeof (zio_error_rank) / sizeof (int); r2++) 2828 if (e2 == zio_error_rank[r2]) 2829 break; 2830 2831 return (r1 > r2 ? e1 : e2); 2832 } 2833 2834 /* 2835 * ========================================================================== 2836 * I/O completion 2837 * ========================================================================== 2838 */ 2839 static int 2840 zio_ready(zio_t *zio) 2841 { 2842 blkptr_t *bp = zio->io_bp; 2843 zio_t *pio, *pio_next; 2844 2845 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 2846 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_READY)) 2847 return (ZIO_PIPELINE_STOP); 2848 2849 if (zio->io_ready) { 2850 ASSERT(IO_IS_ALLOCATING(zio)); 2851 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp) || 2852 (zio->io_flags & ZIO_FLAG_NOPWRITE)); 2853 ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0); 2854 2855 zio->io_ready(zio); 2856 } 2857 2858 if (bp != NULL && bp != &zio->io_bp_copy) 2859 zio->io_bp_copy = *bp; 2860 2861 if (zio->io_error) 2862 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2863 2864 mutex_enter(&zio->io_lock); 2865 zio->io_state[ZIO_WAIT_READY] = 1; 2866 pio = zio_walk_parents(zio); 2867 mutex_exit(&zio->io_lock); 2868 2869 /* 2870 * As we notify zio's parents, new parents could be added. 2871 * New parents go to the head of zio's io_parent_list, however, 2872 * so we will (correctly) not notify them. The remainder of zio's 2873 * io_parent_list, from 'pio_next' onward, cannot change because 2874 * all parents must wait for us to be done before they can be done. 2875 */ 2876 for (; pio != NULL; pio = pio_next) { 2877 pio_next = zio_walk_parents(zio); 2878 zio_notify_parent(pio, zio, ZIO_WAIT_READY); 2879 } 2880 2881 if (zio->io_flags & ZIO_FLAG_NODATA) { 2882 if (BP_IS_GANG(bp)) { 2883 zio->io_flags &= ~ZIO_FLAG_NODATA; 2884 } else { 2885 ASSERT((uintptr_t)zio->io_data < SPA_MAXBLOCKSIZE); 2886 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 2887 } 2888 } 2889 2890 if (zio_injection_enabled && 2891 zio->io_spa->spa_syncing_txg == zio->io_txg) 2892 zio_handle_ignored_writes(zio); 2893 2894 return (ZIO_PIPELINE_CONTINUE); 2895 } 2896 2897 static int 2898 zio_done(zio_t *zio) 2899 { 2900 spa_t *spa = zio->io_spa; 2901 zio_t *lio = zio->io_logical; 2902 blkptr_t *bp = zio->io_bp; 2903 vdev_t *vd = zio->io_vd; 2904 uint64_t psize = zio->io_size; 2905 zio_t *pio, *pio_next; 2906 2907 /* 2908 * If our children haven't all completed, 2909 * wait for them and then repeat this pipeline stage. 2910 */ 2911 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE) || 2912 zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE) || 2913 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE) || 2914 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_DONE)) 2915 return (ZIO_PIPELINE_STOP); 2916 2917 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 2918 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 2919 ASSERT(zio->io_children[c][w] == 0); 2920 2921 if (bp != NULL && !BP_IS_EMBEDDED(bp)) { 2922 ASSERT(bp->blk_pad[0] == 0); 2923 ASSERT(bp->blk_pad[1] == 0); 2924 ASSERT(bcmp(bp, &zio->io_bp_copy, sizeof (blkptr_t)) == 0 || 2925 (bp == zio_unique_parent(zio)->io_bp)); 2926 if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(bp) && 2927 zio->io_bp_override == NULL && 2928 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) { 2929 ASSERT(!BP_SHOULD_BYTESWAP(bp)); 2930 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(bp)); 2931 ASSERT(BP_COUNT_GANG(bp) == 0 || 2932 (BP_COUNT_GANG(bp) == BP_GET_NDVAS(bp))); 2933 } 2934 if (zio->io_flags & ZIO_FLAG_NOPWRITE) 2935 VERIFY(BP_EQUAL(bp, &zio->io_bp_orig)); 2936 } 2937 2938 /* 2939 * If there were child vdev/gang/ddt errors, they apply to us now. 2940 */ 2941 zio_inherit_child_errors(zio, ZIO_CHILD_VDEV); 2942 zio_inherit_child_errors(zio, ZIO_CHILD_GANG); 2943 zio_inherit_child_errors(zio, ZIO_CHILD_DDT); 2944 2945 /* 2946 * If the I/O on the transformed data was successful, generate any 2947 * checksum reports now while we still have the transformed data. 2948 */ 2949 if (zio->io_error == 0) { 2950 while (zio->io_cksum_report != NULL) { 2951 zio_cksum_report_t *zcr = zio->io_cksum_report; 2952 uint64_t align = zcr->zcr_align; 2953 uint64_t asize = P2ROUNDUP(psize, align); 2954 char *abuf = zio->io_data; 2955 2956 if (asize != psize) { 2957 abuf = zio_buf_alloc(asize); 2958 bcopy(zio->io_data, abuf, psize); 2959 bzero(abuf + psize, asize - psize); 2960 } 2961 2962 zio->io_cksum_report = zcr->zcr_next; 2963 zcr->zcr_next = NULL; 2964 zcr->zcr_finish(zcr, abuf); 2965 zfs_ereport_free_checksum(zcr); 2966 2967 if (asize != psize) 2968 zio_buf_free(abuf, asize); 2969 } 2970 } 2971 2972 zio_pop_transforms(zio); /* note: may set zio->io_error */ 2973 2974 vdev_stat_update(zio, psize); 2975 2976 if (zio->io_error) { 2977 /* 2978 * If this I/O is attached to a particular vdev, 2979 * generate an error message describing the I/O failure 2980 * at the block level. We ignore these errors if the 2981 * device is currently unavailable. 2982 */ 2983 if (zio->io_error != ECKSUM && vd != NULL && !vdev_is_dead(vd)) 2984 zfs_ereport_post(FM_EREPORT_ZFS_IO, spa, vd, zio, 0, 0); 2985 2986 if ((zio->io_error == EIO || !(zio->io_flags & 2987 (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) && 2988 zio == lio) { 2989 /* 2990 * For logical I/O requests, tell the SPA to log the 2991 * error and generate a logical data ereport. 2992 */ 2993 spa_log_error(spa, zio); 2994 zfs_ereport_post(FM_EREPORT_ZFS_DATA, spa, NULL, zio, 2995 0, 0); 2996 } 2997 } 2998 2999 if (zio->io_error && zio == lio) { 3000 /* 3001 * Determine whether zio should be reexecuted. This will 3002 * propagate all the way to the root via zio_notify_parent(). 3003 */ 3004 ASSERT(vd == NULL && bp != NULL); 3005 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3006 3007 if (IO_IS_ALLOCATING(zio) && 3008 !(zio->io_flags & ZIO_FLAG_CANFAIL)) { 3009 if (zio->io_error != ENOSPC) 3010 zio->io_reexecute |= ZIO_REEXECUTE_NOW; 3011 else 3012 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3013 } 3014 3015 if ((zio->io_type == ZIO_TYPE_READ || 3016 zio->io_type == ZIO_TYPE_FREE) && 3017 !(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && 3018 zio->io_error == ENXIO && 3019 spa_load_state(spa) == SPA_LOAD_NONE && 3020 spa_get_failmode(spa) != ZIO_FAILURE_MODE_CONTINUE) 3021 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3022 3023 if (!(zio->io_flags & ZIO_FLAG_CANFAIL) && !zio->io_reexecute) 3024 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3025 3026 /* 3027 * Here is a possibly good place to attempt to do 3028 * either combinatorial reconstruction or error correction 3029 * based on checksums. It also might be a good place 3030 * to send out preliminary ereports before we suspend 3031 * processing. 3032 */ 3033 } 3034 3035 /* 3036 * If there were logical child errors, they apply to us now. 3037 * We defer this until now to avoid conflating logical child 3038 * errors with errors that happened to the zio itself when 3039 * updating vdev stats and reporting FMA events above. 3040 */ 3041 zio_inherit_child_errors(zio, ZIO_CHILD_LOGICAL); 3042 3043 if ((zio->io_error || zio->io_reexecute) && 3044 IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio && 3045 !(zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE))) 3046 zio_dva_unallocate(zio, zio->io_gang_tree, bp); 3047 3048 zio_gang_tree_free(&zio->io_gang_tree); 3049 3050 /* 3051 * Godfather I/Os should never suspend. 3052 */ 3053 if ((zio->io_flags & ZIO_FLAG_GODFATHER) && 3054 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) 3055 zio->io_reexecute = 0; 3056 3057 if (zio->io_reexecute) { 3058 /* 3059 * This is a logical I/O that wants to reexecute. 3060 * 3061 * Reexecute is top-down. When an i/o fails, if it's not 3062 * the root, it simply notifies its parent and sticks around. 3063 * The parent, seeing that it still has children in zio_done(), 3064 * does the same. This percolates all the way up to the root. 3065 * The root i/o will reexecute or suspend the entire tree. 3066 * 3067 * This approach ensures that zio_reexecute() honors 3068 * all the original i/o dependency relationships, e.g. 3069 * parents not executing until children are ready. 3070 */ 3071 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3072 3073 zio->io_gang_leader = NULL; 3074 3075 mutex_enter(&zio->io_lock); 3076 zio->io_state[ZIO_WAIT_DONE] = 1; 3077 mutex_exit(&zio->io_lock); 3078 3079 /* 3080 * "The Godfather" I/O monitors its children but is 3081 * not a true parent to them. It will track them through 3082 * the pipeline but severs its ties whenever they get into 3083 * trouble (e.g. suspended). This allows "The Godfather" 3084 * I/O to return status without blocking. 3085 */ 3086 for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) { 3087 zio_link_t *zl = zio->io_walk_link; 3088 pio_next = zio_walk_parents(zio); 3089 3090 if ((pio->io_flags & ZIO_FLAG_GODFATHER) && 3091 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) { 3092 zio_remove_child(pio, zio, zl); 3093 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3094 } 3095 } 3096 3097 if ((pio = zio_unique_parent(zio)) != NULL) { 3098 /* 3099 * We're not a root i/o, so there's nothing to do 3100 * but notify our parent. Don't propagate errors 3101 * upward since we haven't permanently failed yet. 3102 */ 3103 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 3104 zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE; 3105 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3106 } else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) { 3107 /* 3108 * We'd fail again if we reexecuted now, so suspend 3109 * until conditions improve (e.g. device comes online). 3110 */ 3111 zio_suspend(spa, zio); 3112 } else { 3113 /* 3114 * Reexecution is potentially a huge amount of work. 3115 * Hand it off to the otherwise-unused claim taskq. 3116 */ 3117 ASSERT(zio->io_tqent.tqent_next == NULL); 3118 spa_taskq_dispatch_ent(spa, ZIO_TYPE_CLAIM, 3119 ZIO_TASKQ_ISSUE, (task_func_t *)zio_reexecute, zio, 3120 0, &zio->io_tqent); 3121 } 3122 return (ZIO_PIPELINE_STOP); 3123 } 3124 3125 ASSERT(zio->io_child_count == 0); 3126 ASSERT(zio->io_reexecute == 0); 3127 ASSERT(zio->io_error == 0 || (zio->io_flags & ZIO_FLAG_CANFAIL)); 3128 3129 /* 3130 * Report any checksum errors, since the I/O is complete. 3131 */ 3132 while (zio->io_cksum_report != NULL) { 3133 zio_cksum_report_t *zcr = zio->io_cksum_report; 3134 zio->io_cksum_report = zcr->zcr_next; 3135 zcr->zcr_next = NULL; 3136 zcr->zcr_finish(zcr, NULL); 3137 zfs_ereport_free_checksum(zcr); 3138 } 3139 3140 /* 3141 * It is the responsibility of the done callback to ensure that this 3142 * particular zio is no longer discoverable for adoption, and as 3143 * such, cannot acquire any new parents. 3144 */ 3145 if (zio->io_done) 3146 zio->io_done(zio); 3147 3148 mutex_enter(&zio->io_lock); 3149 zio->io_state[ZIO_WAIT_DONE] = 1; 3150 mutex_exit(&zio->io_lock); 3151 3152 for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) { 3153 zio_link_t *zl = zio->io_walk_link; 3154 pio_next = zio_walk_parents(zio); 3155 zio_remove_child(pio, zio, zl); 3156 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3157 } 3158 3159 if (zio->io_waiter != NULL) { 3160 mutex_enter(&zio->io_lock); 3161 zio->io_executor = NULL; 3162 cv_broadcast(&zio->io_cv); 3163 mutex_exit(&zio->io_lock); 3164 } else { 3165 zio_destroy(zio); 3166 } 3167 3168 return (ZIO_PIPELINE_STOP); 3169 } 3170 3171 /* 3172 * ========================================================================== 3173 * I/O pipeline definition 3174 * ========================================================================== 3175 */ 3176 static zio_pipe_stage_t *zio_pipeline[] = { 3177 NULL, 3178 zio_read_bp_init, 3179 zio_free_bp_init, 3180 zio_issue_async, 3181 zio_write_bp_init, 3182 zio_checksum_generate, 3183 zio_nop_write, 3184 zio_ddt_read_start, 3185 zio_ddt_read_done, 3186 zio_ddt_write, 3187 zio_ddt_free, 3188 zio_gang_assemble, 3189 zio_gang_issue, 3190 zio_dva_allocate, 3191 zio_dva_free, 3192 zio_dva_claim, 3193 zio_ready, 3194 zio_vdev_io_start, 3195 zio_vdev_io_done, 3196 zio_vdev_io_assess, 3197 zio_checksum_verify, 3198 zio_done 3199 }; 3200 3201 /* dnp is the dnode for zb1->zb_object */ 3202 boolean_t 3203 zbookmark_is_before(const dnode_phys_t *dnp, const zbookmark_t *zb1, 3204 const zbookmark_t *zb2) 3205 { 3206 uint64_t zb1nextL0, zb2thisobj; 3207 3208 ASSERT(zb1->zb_objset == zb2->zb_objset); 3209 ASSERT(zb2->zb_level == 0); 3210 3211 /* The objset_phys_t isn't before anything. */ 3212 if (dnp == NULL) 3213 return (B_FALSE); 3214 3215 zb1nextL0 = (zb1->zb_blkid + 1) << 3216 ((zb1->zb_level) * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT)); 3217 3218 zb2thisobj = zb2->zb_object ? zb2->zb_object : 3219 zb2->zb_blkid << (DNODE_BLOCK_SHIFT - DNODE_SHIFT); 3220 3221 if (zb1->zb_object == DMU_META_DNODE_OBJECT) { 3222 uint64_t nextobj = zb1nextL0 * 3223 (dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT) >> DNODE_SHIFT; 3224 return (nextobj <= zb2thisobj); 3225 } 3226 3227 if (zb1->zb_object < zb2thisobj) 3228 return (B_TRUE); 3229 if (zb1->zb_object > zb2thisobj) 3230 return (B_FALSE); 3231 if (zb2->zb_object == DMU_META_DNODE_OBJECT) 3232 return (B_FALSE); 3233 return (zb1nextL0 <= zb2->zb_blkid); 3234 } 3235