zio.c revision 297108
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, 2015 by Delphix. All rights reserved. 24 * Copyright (c) 2011 Nexenta Systems, Inc. All rights reserved. 25 */ 26 27#include <sys/sysmacros.h> 28#include <sys/zfs_context.h> 29#include <sys/fm/fs/zfs.h> 30#include <sys/spa.h> 31#include <sys/txg.h> 32#include <sys/spa_impl.h> 33#include <sys/vdev_impl.h> 34#include <sys/zio_impl.h> 35#include <sys/zio_compress.h> 36#include <sys/zio_checksum.h> 37#include <sys/dmu_objset.h> 38#include <sys/arc.h> 39#include <sys/ddt.h> 40#include <sys/trim_map.h> 41#include <sys/blkptr.h> 42#include <sys/zfeature.h> 43 44SYSCTL_DECL(_vfs_zfs); 45SYSCTL_NODE(_vfs_zfs, OID_AUTO, zio, CTLFLAG_RW, 0, "ZFS ZIO"); 46#if defined(__amd64__) 47static int zio_use_uma = 1; 48#else 49static int zio_use_uma = 0; 50#endif 51TUNABLE_INT("vfs.zfs.zio.use_uma", &zio_use_uma); 52SYSCTL_INT(_vfs_zfs_zio, OID_AUTO, use_uma, CTLFLAG_RDTUN, &zio_use_uma, 0, 53 "Use uma(9) for ZIO allocations"); 54static int zio_exclude_metadata = 0; 55TUNABLE_INT("vfs.zfs.zio.exclude_metadata", &zio_exclude_metadata); 56SYSCTL_INT(_vfs_zfs_zio, OID_AUTO, exclude_metadata, CTLFLAG_RDTUN, &zio_exclude_metadata, 0, 57 "Exclude metadata buffers from dumps as well"); 58 59zio_trim_stats_t zio_trim_stats = { 60 { "bytes", KSTAT_DATA_UINT64, 61 "Number of bytes successfully TRIMmed" }, 62 { "success", KSTAT_DATA_UINT64, 63 "Number of successful TRIM requests" }, 64 { "unsupported", KSTAT_DATA_UINT64, 65 "Number of TRIM requests that failed because TRIM is not supported" }, 66 { "failed", KSTAT_DATA_UINT64, 67 "Number of TRIM requests that failed for reasons other than not supported" }, 68}; 69 70static kstat_t *zio_trim_ksp; 71 72/* 73 * ========================================================================== 74 * I/O type descriptions 75 * ========================================================================== 76 */ 77const char *zio_type_name[ZIO_TYPES] = { 78 "zio_null", "zio_read", "zio_write", "zio_free", "zio_claim", 79 "zio_ioctl" 80}; 81 82/* 83 * ========================================================================== 84 * I/O kmem caches 85 * ========================================================================== 86 */ 87kmem_cache_t *zio_cache; 88kmem_cache_t *zio_link_cache; 89kmem_cache_t *zio_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; 90kmem_cache_t *zio_data_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; 91 92#ifdef _KERNEL 93extern vmem_t *zio_alloc_arena; 94#endif 95 96#define ZIO_PIPELINE_CONTINUE 0x100 97#define ZIO_PIPELINE_STOP 0x101 98 99#define BP_SPANB(indblkshift, level) \ 100 (((uint64_t)1) << ((level) * ((indblkshift) - SPA_BLKPTRSHIFT))) 101#define COMPARE_META_LEVEL 0x80000000ul 102/* 103 * The following actions directly effect the spa's sync-to-convergence logic. 104 * The values below define the sync pass when we start performing the action. 105 * Care should be taken when changing these values as they directly impact 106 * spa_sync() performance. Tuning these values may introduce subtle performance 107 * pathologies and should only be done in the context of performance analysis. 108 * These tunables will eventually be removed and replaced with #defines once 109 * enough analysis has been done to determine optimal values. 110 * 111 * The 'zfs_sync_pass_deferred_free' pass must be greater than 1 to ensure that 112 * regular blocks are not deferred. 113 */ 114int zfs_sync_pass_deferred_free = 2; /* defer frees starting in this pass */ 115TUNABLE_INT("vfs.zfs.sync_pass_deferred_free", &zfs_sync_pass_deferred_free); 116SYSCTL_INT(_vfs_zfs, OID_AUTO, sync_pass_deferred_free, CTLFLAG_RDTUN, 117 &zfs_sync_pass_deferred_free, 0, "defer frees starting in this pass"); 118int zfs_sync_pass_dont_compress = 5; /* don't compress starting in this pass */ 119TUNABLE_INT("vfs.zfs.sync_pass_dont_compress", &zfs_sync_pass_dont_compress); 120SYSCTL_INT(_vfs_zfs, OID_AUTO, sync_pass_dont_compress, CTLFLAG_RDTUN, 121 &zfs_sync_pass_dont_compress, 0, "don't compress starting in this pass"); 122int zfs_sync_pass_rewrite = 2; /* rewrite new bps starting in this pass */ 123TUNABLE_INT("vfs.zfs.sync_pass_rewrite", &zfs_sync_pass_rewrite); 124SYSCTL_INT(_vfs_zfs, OID_AUTO, sync_pass_rewrite, CTLFLAG_RDTUN, 125 &zfs_sync_pass_rewrite, 0, "rewrite new bps starting in this pass"); 126 127/* 128 * An allocating zio is one that either currently has the DVA allocate 129 * stage set or will have it later in its lifetime. 130 */ 131#define IO_IS_ALLOCATING(zio) ((zio)->io_orig_pipeline & ZIO_STAGE_DVA_ALLOCATE) 132 133boolean_t zio_requeue_io_start_cut_in_line = B_TRUE; 134 135#ifdef ZFS_DEBUG 136int zio_buf_debug_limit = 16384; 137#else 138int zio_buf_debug_limit = 0; 139#endif 140 141void 142zio_init(void) 143{ 144 size_t c; 145 zio_cache = kmem_cache_create("zio_cache", 146 sizeof (zio_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 147 zio_link_cache = kmem_cache_create("zio_link_cache", 148 sizeof (zio_link_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 149 if (!zio_use_uma) 150 goto out; 151 152 /* 153 * For small buffers, we want a cache for each multiple of 154 * SPA_MINBLOCKSIZE. For larger buffers, we want a cache 155 * for each quarter-power of 2. 156 */ 157 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { 158 size_t size = (c + 1) << SPA_MINBLOCKSHIFT; 159 size_t p2 = size; 160 size_t align = 0; 161 size_t cflags = (size > zio_buf_debug_limit) ? KMC_NODEBUG : 0; 162 163 while (!ISP2(p2)) 164 p2 &= p2 - 1; 165 166#ifdef illumos 167#ifndef _KERNEL 168 /* 169 * If we are using watchpoints, put each buffer on its own page, 170 * to eliminate the performance overhead of trapping to the 171 * kernel when modifying a non-watched buffer that shares the 172 * page with a watched buffer. 173 */ 174 if (arc_watch && !IS_P2ALIGNED(size, PAGESIZE)) 175 continue; 176#endif 177#endif /* illumos */ 178 if (size <= 4 * SPA_MINBLOCKSIZE) { 179 align = SPA_MINBLOCKSIZE; 180 } else if (IS_P2ALIGNED(size, p2 >> 2)) { 181 align = MIN(p2 >> 2, PAGESIZE); 182 } 183 184 if (align != 0) { 185 char name[36]; 186 (void) sprintf(name, "zio_buf_%lu", (ulong_t)size); 187 zio_buf_cache[c] = kmem_cache_create(name, size, 188 align, NULL, NULL, NULL, NULL, NULL, cflags); 189 190 /* 191 * Since zio_data bufs do not appear in crash dumps, we 192 * pass KMC_NOTOUCH so that no allocator metadata is 193 * stored with the buffers. 194 */ 195 (void) sprintf(name, "zio_data_buf_%lu", (ulong_t)size); 196 zio_data_buf_cache[c] = kmem_cache_create(name, size, 197 align, NULL, NULL, NULL, NULL, NULL, 198 cflags | KMC_NOTOUCH | KMC_NODEBUG); 199 } 200 } 201 202 while (--c != 0) { 203 ASSERT(zio_buf_cache[c] != NULL); 204 if (zio_buf_cache[c - 1] == NULL) 205 zio_buf_cache[c - 1] = zio_buf_cache[c]; 206 207 ASSERT(zio_data_buf_cache[c] != NULL); 208 if (zio_data_buf_cache[c - 1] == NULL) 209 zio_data_buf_cache[c - 1] = zio_data_buf_cache[c]; 210 } 211out: 212 213 zio_inject_init(); 214 215 zio_trim_ksp = kstat_create("zfs", 0, "zio_trim", "misc", 216 KSTAT_TYPE_NAMED, 217 sizeof(zio_trim_stats) / sizeof(kstat_named_t), 218 KSTAT_FLAG_VIRTUAL); 219 220 if (zio_trim_ksp != NULL) { 221 zio_trim_ksp->ks_data = &zio_trim_stats; 222 kstat_install(zio_trim_ksp); 223 } 224} 225 226void 227zio_fini(void) 228{ 229 size_t c; 230 kmem_cache_t *last_cache = NULL; 231 kmem_cache_t *last_data_cache = NULL; 232 233 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { 234 if (zio_buf_cache[c] != last_cache) { 235 last_cache = zio_buf_cache[c]; 236 kmem_cache_destroy(zio_buf_cache[c]); 237 } 238 zio_buf_cache[c] = NULL; 239 240 if (zio_data_buf_cache[c] != last_data_cache) { 241 last_data_cache = zio_data_buf_cache[c]; 242 kmem_cache_destroy(zio_data_buf_cache[c]); 243 } 244 zio_data_buf_cache[c] = NULL; 245 } 246 247 kmem_cache_destroy(zio_link_cache); 248 kmem_cache_destroy(zio_cache); 249 250 zio_inject_fini(); 251 252 if (zio_trim_ksp != NULL) { 253 kstat_delete(zio_trim_ksp); 254 zio_trim_ksp = NULL; 255 } 256} 257 258/* 259 * ========================================================================== 260 * Allocate and free I/O buffers 261 * ========================================================================== 262 */ 263 264/* 265 * Use zio_buf_alloc to allocate ZFS metadata. This data will appear in a 266 * crashdump if the kernel panics, so use it judiciously. Obviously, it's 267 * useful to inspect ZFS metadata, but if possible, we should avoid keeping 268 * excess / transient data in-core during a crashdump. 269 */ 270void * 271zio_buf_alloc(size_t size) 272{ 273 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 274 int flags = zio_exclude_metadata ? KM_NODEBUG : 0; 275 276 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 277 278 if (zio_use_uma) 279 return (kmem_cache_alloc(zio_buf_cache[c], KM_PUSHPAGE)); 280 else 281 return (kmem_alloc(size, KM_SLEEP|flags)); 282} 283 284/* 285 * Use zio_data_buf_alloc to allocate data. The data will not appear in a 286 * crashdump if the kernel panics. This exists so that we will limit the amount 287 * of ZFS data that shows up in a kernel crashdump. (Thus reducing the amount 288 * of kernel heap dumped to disk when the kernel panics) 289 */ 290void * 291zio_data_buf_alloc(size_t size) 292{ 293 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 294 295 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 296 297 if (zio_use_uma) 298 return (kmem_cache_alloc(zio_data_buf_cache[c], KM_PUSHPAGE)); 299 else 300 return (kmem_alloc(size, KM_SLEEP | KM_NODEBUG)); 301} 302 303void 304zio_buf_free(void *buf, size_t size) 305{ 306 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 307 308 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 309 310 if (zio_use_uma) 311 kmem_cache_free(zio_buf_cache[c], buf); 312 else 313 kmem_free(buf, size); 314} 315 316void 317zio_data_buf_free(void *buf, size_t size) 318{ 319 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 320 321 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 322 323 if (zio_use_uma) 324 kmem_cache_free(zio_data_buf_cache[c], buf); 325 else 326 kmem_free(buf, size); 327} 328 329/* 330 * ========================================================================== 331 * Push and pop I/O transform buffers 332 * ========================================================================== 333 */ 334static void 335zio_push_transform(zio_t *zio, void *data, uint64_t size, uint64_t bufsize, 336 zio_transform_func_t *transform) 337{ 338 zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP); 339 340 zt->zt_orig_data = zio->io_data; 341 zt->zt_orig_size = zio->io_size; 342 zt->zt_bufsize = bufsize; 343 zt->zt_transform = transform; 344 345 zt->zt_next = zio->io_transform_stack; 346 zio->io_transform_stack = zt; 347 348 zio->io_data = data; 349 zio->io_size = size; 350} 351 352static void 353zio_pop_transforms(zio_t *zio) 354{ 355 zio_transform_t *zt; 356 357 while ((zt = zio->io_transform_stack) != NULL) { 358 if (zt->zt_transform != NULL) 359 zt->zt_transform(zio, 360 zt->zt_orig_data, zt->zt_orig_size); 361 362 if (zt->zt_bufsize != 0) 363 zio_buf_free(zio->io_data, zt->zt_bufsize); 364 365 zio->io_data = zt->zt_orig_data; 366 zio->io_size = zt->zt_orig_size; 367 zio->io_transform_stack = zt->zt_next; 368 369 kmem_free(zt, sizeof (zio_transform_t)); 370 } 371} 372 373/* 374 * ========================================================================== 375 * I/O transform callbacks for subblocks and decompression 376 * ========================================================================== 377 */ 378static void 379zio_subblock(zio_t *zio, void *data, uint64_t size) 380{ 381 ASSERT(zio->io_size > size); 382 383 if (zio->io_type == ZIO_TYPE_READ) 384 bcopy(zio->io_data, data, size); 385} 386 387static void 388zio_decompress(zio_t *zio, void *data, uint64_t size) 389{ 390 if (zio->io_error == 0 && 391 zio_decompress_data(BP_GET_COMPRESS(zio->io_bp), 392 zio->io_data, data, zio->io_size, size) != 0) 393 zio->io_error = SET_ERROR(EIO); 394} 395 396/* 397 * ========================================================================== 398 * I/O parent/child relationships and pipeline interlocks 399 * ========================================================================== 400 */ 401/* 402 * NOTE - Callers to zio_walk_parents() and zio_walk_children must 403 * continue calling these functions until they return NULL. 404 * Otherwise, the next caller will pick up the list walk in 405 * some indeterminate state. (Otherwise every caller would 406 * have to pass in a cookie to keep the state represented by 407 * io_walk_link, which gets annoying.) 408 */ 409zio_t * 410zio_walk_parents(zio_t *cio) 411{ 412 zio_link_t *zl = cio->io_walk_link; 413 list_t *pl = &cio->io_parent_list; 414 415 zl = (zl == NULL) ? list_head(pl) : list_next(pl, zl); 416 cio->io_walk_link = zl; 417 418 if (zl == NULL) 419 return (NULL); 420 421 ASSERT(zl->zl_child == cio); 422 return (zl->zl_parent); 423} 424 425zio_t * 426zio_walk_children(zio_t *pio) 427{ 428 zio_link_t *zl = pio->io_walk_link; 429 list_t *cl = &pio->io_child_list; 430 431 zl = (zl == NULL) ? list_head(cl) : list_next(cl, zl); 432 pio->io_walk_link = zl; 433 434 if (zl == NULL) 435 return (NULL); 436 437 ASSERT(zl->zl_parent == pio); 438 return (zl->zl_child); 439} 440 441zio_t * 442zio_unique_parent(zio_t *cio) 443{ 444 zio_t *pio = zio_walk_parents(cio); 445 446 VERIFY(zio_walk_parents(cio) == NULL); 447 return (pio); 448} 449 450void 451zio_add_child(zio_t *pio, zio_t *cio) 452{ 453 zio_link_t *zl = kmem_cache_alloc(zio_link_cache, KM_SLEEP); 454 455 /* 456 * Logical I/Os can have logical, gang, or vdev children. 457 * Gang I/Os can have gang or vdev children. 458 * Vdev I/Os can only have vdev children. 459 * The following ASSERT captures all of these constraints. 460 */ 461 ASSERT(cio->io_child_type <= pio->io_child_type); 462 463 zl->zl_parent = pio; 464 zl->zl_child = cio; 465 466 mutex_enter(&cio->io_lock); 467 mutex_enter(&pio->io_lock); 468 469 ASSERT(pio->io_state[ZIO_WAIT_DONE] == 0); 470 471 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 472 pio->io_children[cio->io_child_type][w] += !cio->io_state[w]; 473 474 list_insert_head(&pio->io_child_list, zl); 475 list_insert_head(&cio->io_parent_list, zl); 476 477 pio->io_child_count++; 478 cio->io_parent_count++; 479 480 mutex_exit(&pio->io_lock); 481 mutex_exit(&cio->io_lock); 482} 483 484static void 485zio_remove_child(zio_t *pio, zio_t *cio, zio_link_t *zl) 486{ 487 ASSERT(zl->zl_parent == pio); 488 ASSERT(zl->zl_child == cio); 489 490 mutex_enter(&cio->io_lock); 491 mutex_enter(&pio->io_lock); 492 493 list_remove(&pio->io_child_list, zl); 494 list_remove(&cio->io_parent_list, zl); 495 496 pio->io_child_count--; 497 cio->io_parent_count--; 498 499 mutex_exit(&pio->io_lock); 500 mutex_exit(&cio->io_lock); 501 502 kmem_cache_free(zio_link_cache, zl); 503} 504 505static boolean_t 506zio_wait_for_children(zio_t *zio, enum zio_child child, enum zio_wait_type wait) 507{ 508 uint64_t *countp = &zio->io_children[child][wait]; 509 boolean_t waiting = B_FALSE; 510 511 mutex_enter(&zio->io_lock); 512 ASSERT(zio->io_stall == NULL); 513 if (*countp != 0) { 514 zio->io_stage >>= 1; 515 zio->io_stall = countp; 516 waiting = B_TRUE; 517 } 518 mutex_exit(&zio->io_lock); 519 520 return (waiting); 521} 522 523static void 524zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait) 525{ 526 uint64_t *countp = &pio->io_children[zio->io_child_type][wait]; 527 int *errorp = &pio->io_child_error[zio->io_child_type]; 528 529 mutex_enter(&pio->io_lock); 530 if (zio->io_error && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE)) 531 *errorp = zio_worst_error(*errorp, zio->io_error); 532 pio->io_reexecute |= zio->io_reexecute; 533 ASSERT3U(*countp, >, 0); 534 535 (*countp)--; 536 537 if (*countp == 0 && pio->io_stall == countp) { 538 pio->io_stall = NULL; 539 mutex_exit(&pio->io_lock); 540 zio_execute(pio); 541 } else { 542 mutex_exit(&pio->io_lock); 543 } 544} 545 546static void 547zio_inherit_child_errors(zio_t *zio, enum zio_child c) 548{ 549 if (zio->io_child_error[c] != 0 && zio->io_error == 0) 550 zio->io_error = zio->io_child_error[c]; 551} 552 553/* 554 * ========================================================================== 555 * Create the various types of I/O (read, write, free, etc) 556 * ========================================================================== 557 */ 558static zio_t * 559zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 560 void *data, uint64_t size, zio_done_func_t *done, void *private, 561 zio_type_t type, zio_priority_t priority, enum zio_flag flags, 562 vdev_t *vd, uint64_t offset, const zbookmark_phys_t *zb, 563 enum zio_stage stage, enum zio_stage pipeline) 564{ 565 zio_t *zio; 566 567 ASSERT3U(type == ZIO_TYPE_FREE || size, <=, SPA_MAXBLOCKSIZE); 568 ASSERT(P2PHASE(size, SPA_MINBLOCKSIZE) == 0); 569 ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0); 570 571 ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER)); 572 ASSERT(!bp || !(flags & ZIO_FLAG_CONFIG_WRITER)); 573 ASSERT(vd || stage == ZIO_STAGE_OPEN); 574 575 zio = kmem_cache_alloc(zio_cache, KM_SLEEP); 576 bzero(zio, sizeof (zio_t)); 577 578 mutex_init(&zio->io_lock, NULL, MUTEX_DEFAULT, NULL); 579 cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL); 580 581 list_create(&zio->io_parent_list, sizeof (zio_link_t), 582 offsetof(zio_link_t, zl_parent_node)); 583 list_create(&zio->io_child_list, sizeof (zio_link_t), 584 offsetof(zio_link_t, zl_child_node)); 585 586 if (vd != NULL) 587 zio->io_child_type = ZIO_CHILD_VDEV; 588 else if (flags & ZIO_FLAG_GANG_CHILD) 589 zio->io_child_type = ZIO_CHILD_GANG; 590 else if (flags & ZIO_FLAG_DDT_CHILD) 591 zio->io_child_type = ZIO_CHILD_DDT; 592 else 593 zio->io_child_type = ZIO_CHILD_LOGICAL; 594 595 if (bp != NULL) { 596 zio->io_bp = (blkptr_t *)bp; 597 zio->io_bp_copy = *bp; 598 zio->io_bp_orig = *bp; 599 if (type != ZIO_TYPE_WRITE || 600 zio->io_child_type == ZIO_CHILD_DDT) 601 zio->io_bp = &zio->io_bp_copy; /* so caller can free */ 602 if (zio->io_child_type == ZIO_CHILD_LOGICAL) 603 zio->io_logical = zio; 604 if (zio->io_child_type > ZIO_CHILD_GANG && BP_IS_GANG(bp)) 605 pipeline |= ZIO_GANG_STAGES; 606 } 607 608 zio->io_spa = spa; 609 zio->io_txg = txg; 610 zio->io_done = done; 611 zio->io_private = private; 612 zio->io_type = type; 613 zio->io_priority = priority; 614 zio->io_vd = vd; 615 zio->io_offset = offset; 616 zio->io_orig_data = zio->io_data = data; 617 zio->io_orig_size = zio->io_size = size; 618 zio->io_orig_flags = zio->io_flags = flags; 619 zio->io_orig_stage = zio->io_stage = stage; 620 zio->io_orig_pipeline = zio->io_pipeline = pipeline; 621 622 zio->io_state[ZIO_WAIT_READY] = (stage >= ZIO_STAGE_READY); 623 zio->io_state[ZIO_WAIT_DONE] = (stage >= ZIO_STAGE_DONE); 624 625 if (zb != NULL) 626 zio->io_bookmark = *zb; 627 628 if (pio != NULL) { 629 if (zio->io_logical == NULL) 630 zio->io_logical = pio->io_logical; 631 if (zio->io_child_type == ZIO_CHILD_GANG) 632 zio->io_gang_leader = pio->io_gang_leader; 633 zio_add_child(pio, zio); 634 } 635 636 return (zio); 637} 638 639static void 640zio_destroy(zio_t *zio) 641{ 642 list_destroy(&zio->io_parent_list); 643 list_destroy(&zio->io_child_list); 644 mutex_destroy(&zio->io_lock); 645 cv_destroy(&zio->io_cv); 646 kmem_cache_free(zio_cache, zio); 647} 648 649zio_t * 650zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, zio_done_func_t *done, 651 void *private, enum zio_flag flags) 652{ 653 zio_t *zio; 654 655 zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private, 656 ZIO_TYPE_NULL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL, 657 ZIO_STAGE_OPEN, ZIO_INTERLOCK_PIPELINE); 658 659 return (zio); 660} 661 662zio_t * 663zio_root(spa_t *spa, zio_done_func_t *done, void *private, enum zio_flag flags) 664{ 665 return (zio_null(NULL, spa, NULL, done, private, flags)); 666} 667 668void 669zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp) 670{ 671 if (!DMU_OT_IS_VALID(BP_GET_TYPE(bp))) { 672 zfs_panic_recover("blkptr at %p has invalid TYPE %llu", 673 bp, (longlong_t)BP_GET_TYPE(bp)); 674 } 675 if (BP_GET_CHECKSUM(bp) >= ZIO_CHECKSUM_FUNCTIONS || 676 BP_GET_CHECKSUM(bp) <= ZIO_CHECKSUM_ON) { 677 zfs_panic_recover("blkptr at %p has invalid CHECKSUM %llu", 678 bp, (longlong_t)BP_GET_CHECKSUM(bp)); 679 } 680 if (BP_GET_COMPRESS(bp) >= ZIO_COMPRESS_FUNCTIONS || 681 BP_GET_COMPRESS(bp) <= ZIO_COMPRESS_ON) { 682 zfs_panic_recover("blkptr at %p has invalid COMPRESS %llu", 683 bp, (longlong_t)BP_GET_COMPRESS(bp)); 684 } 685 if (BP_GET_LSIZE(bp) > SPA_MAXBLOCKSIZE) { 686 zfs_panic_recover("blkptr at %p has invalid LSIZE %llu", 687 bp, (longlong_t)BP_GET_LSIZE(bp)); 688 } 689 if (BP_GET_PSIZE(bp) > SPA_MAXBLOCKSIZE) { 690 zfs_panic_recover("blkptr at %p has invalid PSIZE %llu", 691 bp, (longlong_t)BP_GET_PSIZE(bp)); 692 } 693 694 if (BP_IS_EMBEDDED(bp)) { 695 if (BPE_GET_ETYPE(bp) > NUM_BP_EMBEDDED_TYPES) { 696 zfs_panic_recover("blkptr at %p has invalid ETYPE %llu", 697 bp, (longlong_t)BPE_GET_ETYPE(bp)); 698 } 699 } 700 701 /* 702 * Pool-specific checks. 703 * 704 * Note: it would be nice to verify that the blk_birth and 705 * BP_PHYSICAL_BIRTH() are not too large. However, spa_freeze() 706 * allows the birth time of log blocks (and dmu_sync()-ed blocks 707 * that are in the log) to be arbitrarily large. 708 */ 709 for (int i = 0; i < BP_GET_NDVAS(bp); i++) { 710 uint64_t vdevid = DVA_GET_VDEV(&bp->blk_dva[i]); 711 if (vdevid >= spa->spa_root_vdev->vdev_children) { 712 zfs_panic_recover("blkptr at %p DVA %u has invalid " 713 "VDEV %llu", 714 bp, i, (longlong_t)vdevid); 715 continue; 716 } 717 vdev_t *vd = spa->spa_root_vdev->vdev_child[vdevid]; 718 if (vd == NULL) { 719 zfs_panic_recover("blkptr at %p DVA %u has invalid " 720 "VDEV %llu", 721 bp, i, (longlong_t)vdevid); 722 continue; 723 } 724 if (vd->vdev_ops == &vdev_hole_ops) { 725 zfs_panic_recover("blkptr at %p DVA %u has hole " 726 "VDEV %llu", 727 bp, i, (longlong_t)vdevid); 728 continue; 729 } 730 if (vd->vdev_ops == &vdev_missing_ops) { 731 /* 732 * "missing" vdevs are valid during import, but we 733 * don't have their detailed info (e.g. asize), so 734 * we can't perform any more checks on them. 735 */ 736 continue; 737 } 738 uint64_t offset = DVA_GET_OFFSET(&bp->blk_dva[i]); 739 uint64_t asize = DVA_GET_ASIZE(&bp->blk_dva[i]); 740 if (BP_IS_GANG(bp)) 741 asize = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE); 742 if (offset + asize > vd->vdev_asize) { 743 zfs_panic_recover("blkptr at %p DVA %u has invalid " 744 "OFFSET %llu", 745 bp, i, (longlong_t)offset); 746 } 747 } 748} 749 750zio_t * 751zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, 752 void *data, uint64_t size, zio_done_func_t *done, void *private, 753 zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb) 754{ 755 zio_t *zio; 756 757 zfs_blkptr_verify(spa, bp); 758 759 zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp, 760 data, size, done, private, 761 ZIO_TYPE_READ, priority, flags, NULL, 0, zb, 762 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 763 ZIO_DDT_CHILD_READ_PIPELINE : ZIO_READ_PIPELINE); 764 765 return (zio); 766} 767 768zio_t * 769zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, 770 void *data, uint64_t size, const zio_prop_t *zp, 771 zio_done_func_t *ready, zio_done_func_t *physdone, zio_done_func_t *done, 772 void *private, 773 zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb) 774{ 775 zio_t *zio; 776 777 ASSERT(zp->zp_checksum >= ZIO_CHECKSUM_OFF && 778 zp->zp_checksum < ZIO_CHECKSUM_FUNCTIONS && 779 zp->zp_compress >= ZIO_COMPRESS_OFF && 780 zp->zp_compress < ZIO_COMPRESS_FUNCTIONS && 781 DMU_OT_IS_VALID(zp->zp_type) && 782 zp->zp_level < 32 && 783 zp->zp_copies > 0 && 784 zp->zp_copies <= spa_max_replication(spa)); 785 786 zio = zio_create(pio, spa, txg, bp, data, size, done, private, 787 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 788 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 789 ZIO_DDT_CHILD_WRITE_PIPELINE : ZIO_WRITE_PIPELINE); 790 791 zio->io_ready = ready; 792 zio->io_physdone = physdone; 793 zio->io_prop = *zp; 794 795 /* 796 * Data can be NULL if we are going to call zio_write_override() to 797 * provide the already-allocated BP. But we may need the data to 798 * verify a dedup hit (if requested). In this case, don't try to 799 * dedup (just take the already-allocated BP verbatim). 800 */ 801 if (data == NULL && zio->io_prop.zp_dedup_verify) { 802 zio->io_prop.zp_dedup = zio->io_prop.zp_dedup_verify = B_FALSE; 803 } 804 805 return (zio); 806} 807 808zio_t * 809zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, void *data, 810 uint64_t size, zio_done_func_t *done, void *private, 811 zio_priority_t priority, enum zio_flag flags, zbookmark_phys_t *zb) 812{ 813 zio_t *zio; 814 815 zio = zio_create(pio, spa, txg, bp, data, size, done, private, 816 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 817 ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE); 818 819 return (zio); 820} 821 822void 823zio_write_override(zio_t *zio, blkptr_t *bp, int copies, boolean_t nopwrite) 824{ 825 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 826 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 827 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 828 ASSERT(zio->io_txg == spa_syncing_txg(zio->io_spa)); 829 830 /* 831 * We must reset the io_prop to match the values that existed 832 * when the bp was first written by dmu_sync() keeping in mind 833 * that nopwrite and dedup are mutually exclusive. 834 */ 835 zio->io_prop.zp_dedup = nopwrite ? B_FALSE : zio->io_prop.zp_dedup; 836 zio->io_prop.zp_nopwrite = nopwrite; 837 zio->io_prop.zp_copies = copies; 838 zio->io_bp_override = bp; 839} 840 841void 842zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp) 843{ 844 845 /* 846 * The check for EMBEDDED is a performance optimization. We 847 * process the free here (by ignoring it) rather than 848 * putting it on the list and then processing it in zio_free_sync(). 849 */ 850 if (BP_IS_EMBEDDED(bp)) 851 return; 852 metaslab_check_free(spa, bp); 853 854 /* 855 * Frees that are for the currently-syncing txg, are not going to be 856 * deferred, and which will not need to do a read (i.e. not GANG or 857 * DEDUP), can be processed immediately. Otherwise, put them on the 858 * in-memory list for later processing. 859 */ 860 if (zfs_trim_enabled || BP_IS_GANG(bp) || BP_GET_DEDUP(bp) || 861 txg != spa->spa_syncing_txg || 862 spa_sync_pass(spa) >= zfs_sync_pass_deferred_free) { 863 bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp); 864 } else { 865 VERIFY0(zio_wait(zio_free_sync(NULL, spa, txg, bp, 866 BP_GET_PSIZE(bp), 0))); 867 } 868} 869 870zio_t * 871zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 872 uint64_t size, enum zio_flag flags) 873{ 874 zio_t *zio; 875 enum zio_stage stage = ZIO_FREE_PIPELINE; 876 877 ASSERT(!BP_IS_HOLE(bp)); 878 ASSERT(spa_syncing_txg(spa) == txg); 879 ASSERT(spa_sync_pass(spa) < zfs_sync_pass_deferred_free); 880 881 if (BP_IS_EMBEDDED(bp)) 882 return (zio_null(pio, spa, NULL, NULL, NULL, 0)); 883 884 metaslab_check_free(spa, bp); 885 arc_freed(spa, bp); 886 887 if (zfs_trim_enabled) 888 stage |= ZIO_STAGE_ISSUE_ASYNC | ZIO_STAGE_VDEV_IO_START | 889 ZIO_STAGE_VDEV_IO_ASSESS; 890 /* 891 * GANG and DEDUP blocks can induce a read (for the gang block header, 892 * or the DDT), so issue them asynchronously so that this thread is 893 * not tied up. 894 */ 895 else if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp)) 896 stage |= ZIO_STAGE_ISSUE_ASYNC; 897 898 flags |= ZIO_FLAG_DONT_QUEUE; 899 900 zio = zio_create(pio, spa, txg, bp, NULL, size, 901 NULL, NULL, ZIO_TYPE_FREE, ZIO_PRIORITY_NOW, flags, 902 NULL, 0, NULL, ZIO_STAGE_OPEN, stage); 903 904 return (zio); 905} 906 907zio_t * 908zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 909 zio_done_func_t *done, void *private, enum zio_flag flags) 910{ 911 zio_t *zio; 912 913 dprintf_bp(bp, "claiming in txg %llu", txg); 914 915 if (BP_IS_EMBEDDED(bp)) 916 return (zio_null(pio, spa, NULL, NULL, NULL, 0)); 917 918 /* 919 * A claim is an allocation of a specific block. Claims are needed 920 * to support immediate writes in the intent log. The issue is that 921 * immediate writes contain committed data, but in a txg that was 922 * *not* committed. Upon opening the pool after an unclean shutdown, 923 * the intent log claims all blocks that contain immediate write data 924 * so that the SPA knows they're in use. 925 * 926 * All claims *must* be resolved in the first txg -- before the SPA 927 * starts allocating blocks -- so that nothing is allocated twice. 928 * If txg == 0 we just verify that the block is claimable. 929 */ 930 ASSERT3U(spa->spa_uberblock.ub_rootbp.blk_birth, <, spa_first_txg(spa)); 931 ASSERT(txg == spa_first_txg(spa) || txg == 0); 932 ASSERT(!BP_GET_DEDUP(bp) || !spa_writeable(spa)); /* zdb(1M) */ 933 934 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 935 done, private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW, flags, 936 NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE); 937 938 return (zio); 939} 940 941zio_t * 942zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd, uint64_t offset, 943 uint64_t size, zio_done_func_t *done, void *private, 944 zio_priority_t priority, enum zio_flag flags) 945{ 946 zio_t *zio; 947 int c; 948 949 if (vd->vdev_children == 0) { 950 zio = zio_create(pio, spa, 0, NULL, NULL, size, done, private, 951 ZIO_TYPE_IOCTL, priority, flags, vd, offset, NULL, 952 ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE); 953 954 zio->io_cmd = cmd; 955 } else { 956 zio = zio_null(pio, spa, NULL, NULL, NULL, flags); 957 958 for (c = 0; c < vd->vdev_children; c++) 959 zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd, 960 offset, size, done, private, priority, flags)); 961 } 962 963 return (zio); 964} 965 966zio_t * 967zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 968 void *data, int checksum, zio_done_func_t *done, void *private, 969 zio_priority_t priority, enum zio_flag flags, boolean_t labels) 970{ 971 zio_t *zio; 972 973 ASSERT(vd->vdev_children == 0); 974 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 975 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 976 ASSERT3U(offset + size, <=, vd->vdev_psize); 977 978 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private, 979 ZIO_TYPE_READ, priority, flags | ZIO_FLAG_PHYSICAL, vd, offset, 980 NULL, ZIO_STAGE_OPEN, ZIO_READ_PHYS_PIPELINE); 981 982 zio->io_prop.zp_checksum = checksum; 983 984 return (zio); 985} 986 987zio_t * 988zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 989 void *data, int checksum, zio_done_func_t *done, void *private, 990 zio_priority_t priority, enum zio_flag flags, boolean_t labels) 991{ 992 zio_t *zio; 993 994 ASSERT(vd->vdev_children == 0); 995 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 996 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 997 ASSERT3U(offset + size, <=, vd->vdev_psize); 998 999 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private, 1000 ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_PHYSICAL, vd, offset, 1001 NULL, ZIO_STAGE_OPEN, ZIO_WRITE_PHYS_PIPELINE); 1002 1003 zio->io_prop.zp_checksum = checksum; 1004 1005 if (zio_checksum_table[checksum].ci_flags & ZCHECKSUM_FLAG_EMBEDDED) { 1006 /* 1007 * zec checksums are necessarily destructive -- they modify 1008 * the end of the write buffer to hold the verifier/checksum. 1009 * Therefore, we must make a local copy in case the data is 1010 * being written to multiple places in parallel. 1011 */ 1012 void *wbuf = zio_buf_alloc(size); 1013 bcopy(data, wbuf, size); 1014 zio_push_transform(zio, wbuf, size, size, NULL); 1015 } 1016 1017 return (zio); 1018} 1019 1020/* 1021 * Create a child I/O to do some work for us. 1022 */ 1023zio_t * 1024zio_vdev_child_io(zio_t *pio, blkptr_t *bp, vdev_t *vd, uint64_t offset, 1025 void *data, uint64_t size, int type, zio_priority_t priority, 1026 enum zio_flag flags, zio_done_func_t *done, void *private) 1027{ 1028 enum zio_stage pipeline = ZIO_VDEV_CHILD_PIPELINE; 1029 zio_t *zio; 1030 1031 ASSERT(vd->vdev_parent == 1032 (pio->io_vd ? pio->io_vd : pio->io_spa->spa_root_vdev)); 1033 1034 if (type == ZIO_TYPE_READ && bp != NULL) { 1035 /* 1036 * If we have the bp, then the child should perform the 1037 * checksum and the parent need not. This pushes error 1038 * detection as close to the leaves as possible and 1039 * eliminates redundant checksums in the interior nodes. 1040 */ 1041 pipeline |= ZIO_STAGE_CHECKSUM_VERIFY; 1042 pio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 1043 } 1044 1045 /* Not all IO types require vdev io done stage e.g. free */ 1046 if (!(pio->io_pipeline & ZIO_STAGE_VDEV_IO_DONE)) 1047 pipeline &= ~ZIO_STAGE_VDEV_IO_DONE; 1048 1049 if (vd->vdev_children == 0) 1050 offset += VDEV_LABEL_START_SIZE; 1051 1052 flags |= ZIO_VDEV_CHILD_FLAGS(pio) | ZIO_FLAG_DONT_PROPAGATE; 1053 1054 /* 1055 * If we've decided to do a repair, the write is not speculative -- 1056 * even if the original read was. 1057 */ 1058 if (flags & ZIO_FLAG_IO_REPAIR) 1059 flags &= ~ZIO_FLAG_SPECULATIVE; 1060 1061 zio = zio_create(pio, pio->io_spa, pio->io_txg, bp, data, size, 1062 done, private, type, priority, flags, vd, offset, &pio->io_bookmark, 1063 ZIO_STAGE_VDEV_IO_START >> 1, pipeline); 1064 1065 zio->io_physdone = pio->io_physdone; 1066 if (vd->vdev_ops->vdev_op_leaf && zio->io_logical != NULL) 1067 zio->io_logical->io_phys_children++; 1068 1069 return (zio); 1070} 1071 1072zio_t * 1073zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, void *data, uint64_t size, 1074 int type, zio_priority_t priority, enum zio_flag flags, 1075 zio_done_func_t *done, void *private) 1076{ 1077 zio_t *zio; 1078 1079 ASSERT(vd->vdev_ops->vdev_op_leaf); 1080 1081 zio = zio_create(NULL, vd->vdev_spa, 0, NULL, 1082 data, size, done, private, type, priority, 1083 flags | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY | ZIO_FLAG_DELEGATED, 1084 vd, offset, NULL, 1085 ZIO_STAGE_VDEV_IO_START >> 1, ZIO_VDEV_CHILD_PIPELINE); 1086 1087 return (zio); 1088} 1089 1090void 1091zio_flush(zio_t *zio, vdev_t *vd) 1092{ 1093 zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE, 0, 0, 1094 NULL, NULL, ZIO_PRIORITY_NOW, 1095 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY)); 1096} 1097 1098zio_t * 1099zio_trim(zio_t *zio, spa_t *spa, vdev_t *vd, uint64_t offset, uint64_t size) 1100{ 1101 1102 ASSERT(vd->vdev_ops->vdev_op_leaf); 1103 1104 return (zio_create(zio, spa, 0, NULL, NULL, size, NULL, NULL, 1105 ZIO_TYPE_FREE, ZIO_PRIORITY_TRIM, ZIO_FLAG_DONT_AGGREGATE | 1106 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY, 1107 vd, offset, NULL, ZIO_STAGE_OPEN, ZIO_FREE_PHYS_PIPELINE)); 1108} 1109 1110void 1111zio_shrink(zio_t *zio, uint64_t size) 1112{ 1113 ASSERT(zio->io_executor == NULL); 1114 ASSERT(zio->io_orig_size == zio->io_size); 1115 ASSERT(size <= zio->io_size); 1116 1117 /* 1118 * We don't shrink for raidz because of problems with the 1119 * reconstruction when reading back less than the block size. 1120 * Note, BP_IS_RAIDZ() assumes no compression. 1121 */ 1122 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 1123 if (!BP_IS_RAIDZ(zio->io_bp)) 1124 zio->io_orig_size = zio->io_size = size; 1125} 1126 1127/* 1128 * ========================================================================== 1129 * Prepare to read and write logical blocks 1130 * ========================================================================== 1131 */ 1132 1133static int 1134zio_read_bp_init(zio_t *zio) 1135{ 1136 blkptr_t *bp = zio->io_bp; 1137 1138 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF && 1139 zio->io_child_type == ZIO_CHILD_LOGICAL && 1140 !(zio->io_flags & ZIO_FLAG_RAW)) { 1141 uint64_t psize = 1142 BP_IS_EMBEDDED(bp) ? BPE_GET_PSIZE(bp) : BP_GET_PSIZE(bp); 1143 void *cbuf = zio_buf_alloc(psize); 1144 1145 zio_push_transform(zio, cbuf, psize, psize, zio_decompress); 1146 } 1147 1148 if (BP_IS_EMBEDDED(bp) && BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA) { 1149 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1150 decode_embedded_bp_compressed(bp, zio->io_data); 1151 } else { 1152 ASSERT(!BP_IS_EMBEDDED(bp)); 1153 } 1154 1155 if (!DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) && BP_GET_LEVEL(bp) == 0) 1156 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 1157 1158 if (BP_GET_TYPE(bp) == DMU_OT_DDT_ZAP) 1159 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 1160 1161 if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL) 1162 zio->io_pipeline = ZIO_DDT_READ_PIPELINE; 1163 1164 return (ZIO_PIPELINE_CONTINUE); 1165} 1166 1167static int 1168zio_write_bp_init(zio_t *zio) 1169{ 1170 spa_t *spa = zio->io_spa; 1171 zio_prop_t *zp = &zio->io_prop; 1172 enum zio_compress compress = zp->zp_compress; 1173 blkptr_t *bp = zio->io_bp; 1174 uint64_t lsize = zio->io_size; 1175 uint64_t psize = lsize; 1176 int pass = 1; 1177 1178 /* 1179 * If our children haven't all reached the ready stage, 1180 * wait for them and then repeat this pipeline stage. 1181 */ 1182 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 1183 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_READY)) 1184 return (ZIO_PIPELINE_STOP); 1185 1186 if (!IO_IS_ALLOCATING(zio)) 1187 return (ZIO_PIPELINE_CONTINUE); 1188 1189 ASSERT(zio->io_child_type != ZIO_CHILD_DDT); 1190 1191 if (zio->io_bp_override) { 1192 ASSERT(bp->blk_birth != zio->io_txg); 1193 ASSERT(BP_GET_DEDUP(zio->io_bp_override) == 0); 1194 1195 *bp = *zio->io_bp_override; 1196 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1197 1198 if (BP_IS_EMBEDDED(bp)) 1199 return (ZIO_PIPELINE_CONTINUE); 1200 1201 /* 1202 * If we've been overridden and nopwrite is set then 1203 * set the flag accordingly to indicate that a nopwrite 1204 * has already occurred. 1205 */ 1206 if (!BP_IS_HOLE(bp) && zp->zp_nopwrite) { 1207 ASSERT(!zp->zp_dedup); 1208 zio->io_flags |= ZIO_FLAG_NOPWRITE; 1209 return (ZIO_PIPELINE_CONTINUE); 1210 } 1211 1212 ASSERT(!zp->zp_nopwrite); 1213 1214 if (BP_IS_HOLE(bp) || !zp->zp_dedup) 1215 return (ZIO_PIPELINE_CONTINUE); 1216 1217 ASSERT((zio_checksum_table[zp->zp_checksum].ci_flags & 1218 ZCHECKSUM_FLAG_DEDUP) || zp->zp_dedup_verify); 1219 1220 if (BP_GET_CHECKSUM(bp) == zp->zp_checksum) { 1221 BP_SET_DEDUP(bp, 1); 1222 zio->io_pipeline |= ZIO_STAGE_DDT_WRITE; 1223 return (ZIO_PIPELINE_CONTINUE); 1224 } 1225 zio->io_bp_override = NULL; 1226 BP_ZERO(bp); 1227 } 1228 1229 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg) { 1230 /* 1231 * We're rewriting an existing block, which means we're 1232 * working on behalf of spa_sync(). For spa_sync() to 1233 * converge, it must eventually be the case that we don't 1234 * have to allocate new blocks. But compression changes 1235 * the blocksize, which forces a reallocate, and makes 1236 * convergence take longer. Therefore, after the first 1237 * few passes, stop compressing to ensure convergence. 1238 */ 1239 pass = spa_sync_pass(spa); 1240 1241 ASSERT(zio->io_txg == spa_syncing_txg(spa)); 1242 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1243 ASSERT(!BP_GET_DEDUP(bp)); 1244 1245 if (pass >= zfs_sync_pass_dont_compress) 1246 compress = ZIO_COMPRESS_OFF; 1247 1248 /* Make sure someone doesn't change their mind on overwrites */ 1249 ASSERT(BP_IS_EMBEDDED(bp) || MIN(zp->zp_copies + BP_IS_GANG(bp), 1250 spa_max_replication(spa)) == BP_GET_NDVAS(bp)); 1251 } 1252 1253 if (compress != ZIO_COMPRESS_OFF) { 1254 void *cbuf = zio_buf_alloc(lsize); 1255 psize = zio_compress_data(compress, zio->io_data, cbuf, lsize); 1256 if (psize == 0 || psize == lsize) { 1257 compress = ZIO_COMPRESS_OFF; 1258 zio_buf_free(cbuf, lsize); 1259 } else if (!zp->zp_dedup && psize <= BPE_PAYLOAD_SIZE && 1260 zp->zp_level == 0 && !DMU_OT_HAS_FILL(zp->zp_type) && 1261 spa_feature_is_enabled(spa, SPA_FEATURE_EMBEDDED_DATA)) { 1262 encode_embedded_bp_compressed(bp, 1263 cbuf, compress, lsize, psize); 1264 BPE_SET_ETYPE(bp, BP_EMBEDDED_TYPE_DATA); 1265 BP_SET_TYPE(bp, zio->io_prop.zp_type); 1266 BP_SET_LEVEL(bp, zio->io_prop.zp_level); 1267 zio_buf_free(cbuf, lsize); 1268 bp->blk_birth = zio->io_txg; 1269 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1270 ASSERT(spa_feature_is_active(spa, 1271 SPA_FEATURE_EMBEDDED_DATA)); 1272 return (ZIO_PIPELINE_CONTINUE); 1273 } else { 1274 /* 1275 * Round up compressed size up to the ashift 1276 * of the smallest-ashift device, and zero the tail. 1277 * This ensures that the compressed size of the BP 1278 * (and thus compressratio property) are correct, 1279 * in that we charge for the padding used to fill out 1280 * the last sector. 1281 */ 1282 ASSERT3U(spa->spa_min_ashift, >=, SPA_MINBLOCKSHIFT); 1283 size_t rounded = (size_t)P2ROUNDUP(psize, 1284 1ULL << spa->spa_min_ashift); 1285 if (rounded >= lsize) { 1286 compress = ZIO_COMPRESS_OFF; 1287 zio_buf_free(cbuf, lsize); 1288 psize = lsize; 1289 } else { 1290 bzero((char *)cbuf + psize, rounded - psize); 1291 psize = rounded; 1292 zio_push_transform(zio, cbuf, 1293 psize, lsize, NULL); 1294 } 1295 } 1296 } 1297 1298 /* 1299 * The final pass of spa_sync() must be all rewrites, but the first 1300 * few passes offer a trade-off: allocating blocks defers convergence, 1301 * but newly allocated blocks are sequential, so they can be written 1302 * to disk faster. Therefore, we allow the first few passes of 1303 * spa_sync() to allocate new blocks, but force rewrites after that. 1304 * There should only be a handful of blocks after pass 1 in any case. 1305 */ 1306 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg && 1307 BP_GET_PSIZE(bp) == psize && 1308 pass >= zfs_sync_pass_rewrite) { 1309 ASSERT(psize != 0); 1310 enum zio_stage gang_stages = zio->io_pipeline & ZIO_GANG_STAGES; 1311 zio->io_pipeline = ZIO_REWRITE_PIPELINE | gang_stages; 1312 zio->io_flags |= ZIO_FLAG_IO_REWRITE; 1313 } else { 1314 BP_ZERO(bp); 1315 zio->io_pipeline = ZIO_WRITE_PIPELINE; 1316 } 1317 1318 if (psize == 0) { 1319 if (zio->io_bp_orig.blk_birth != 0 && 1320 spa_feature_is_active(spa, SPA_FEATURE_HOLE_BIRTH)) { 1321 BP_SET_LSIZE(bp, lsize); 1322 BP_SET_TYPE(bp, zp->zp_type); 1323 BP_SET_LEVEL(bp, zp->zp_level); 1324 BP_SET_BIRTH(bp, zio->io_txg, 0); 1325 } 1326 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1327 } else { 1328 ASSERT(zp->zp_checksum != ZIO_CHECKSUM_GANG_HEADER); 1329 BP_SET_LSIZE(bp, lsize); 1330 BP_SET_TYPE(bp, zp->zp_type); 1331 BP_SET_LEVEL(bp, zp->zp_level); 1332 BP_SET_PSIZE(bp, psize); 1333 BP_SET_COMPRESS(bp, compress); 1334 BP_SET_CHECKSUM(bp, zp->zp_checksum); 1335 BP_SET_DEDUP(bp, zp->zp_dedup); 1336 BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER); 1337 if (zp->zp_dedup) { 1338 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1339 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1340 zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE; 1341 } 1342 if (zp->zp_nopwrite) { 1343 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1344 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1345 zio->io_pipeline |= ZIO_STAGE_NOP_WRITE; 1346 } 1347 } 1348 1349 return (ZIO_PIPELINE_CONTINUE); 1350} 1351 1352static int 1353zio_free_bp_init(zio_t *zio) 1354{ 1355 blkptr_t *bp = zio->io_bp; 1356 1357 if (zio->io_child_type == ZIO_CHILD_LOGICAL) { 1358 if (BP_GET_DEDUP(bp)) 1359 zio->io_pipeline = ZIO_DDT_FREE_PIPELINE; 1360 } 1361 1362 return (ZIO_PIPELINE_CONTINUE); 1363} 1364 1365/* 1366 * ========================================================================== 1367 * Execute the I/O pipeline 1368 * ========================================================================== 1369 */ 1370 1371static void 1372zio_taskq_dispatch(zio_t *zio, zio_taskq_type_t q, boolean_t cutinline) 1373{ 1374 spa_t *spa = zio->io_spa; 1375 zio_type_t t = zio->io_type; 1376 int flags = (cutinline ? TQ_FRONT : 0); 1377 1378 ASSERT(q == ZIO_TASKQ_ISSUE || q == ZIO_TASKQ_INTERRUPT); 1379 1380 /* 1381 * If we're a config writer or a probe, the normal issue and 1382 * interrupt threads may all be blocked waiting for the config lock. 1383 * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL. 1384 */ 1385 if (zio->io_flags & (ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_PROBE)) 1386 t = ZIO_TYPE_NULL; 1387 1388 /* 1389 * A similar issue exists for the L2ARC write thread until L2ARC 2.0. 1390 */ 1391 if (t == ZIO_TYPE_WRITE && zio->io_vd && zio->io_vd->vdev_aux) 1392 t = ZIO_TYPE_NULL; 1393 1394 /* 1395 * If this is a high priority I/O, then use the high priority taskq if 1396 * available. 1397 */ 1398 if (zio->io_priority == ZIO_PRIORITY_NOW && 1399 spa->spa_zio_taskq[t][q + 1].stqs_count != 0) 1400 q++; 1401 1402 ASSERT3U(q, <, ZIO_TASKQ_TYPES); 1403 1404 /* 1405 * NB: We are assuming that the zio can only be dispatched 1406 * to a single taskq at a time. It would be a grievous error 1407 * to dispatch the zio to another taskq at the same time. 1408 */ 1409#if defined(illumos) || !defined(_KERNEL) 1410 ASSERT(zio->io_tqent.tqent_next == NULL); 1411#else 1412 ASSERT(zio->io_tqent.tqent_task.ta_pending == 0); 1413#endif 1414 spa_taskq_dispatch_ent(spa, t, q, (task_func_t *)zio_execute, zio, 1415 flags, &zio->io_tqent); 1416} 1417 1418static boolean_t 1419zio_taskq_member(zio_t *zio, zio_taskq_type_t q) 1420{ 1421 kthread_t *executor = zio->io_executor; 1422 spa_t *spa = zio->io_spa; 1423 1424 for (zio_type_t t = 0; t < ZIO_TYPES; t++) { 1425 spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q]; 1426 uint_t i; 1427 for (i = 0; i < tqs->stqs_count; i++) { 1428 if (taskq_member(tqs->stqs_taskq[i], executor)) 1429 return (B_TRUE); 1430 } 1431 } 1432 1433 return (B_FALSE); 1434} 1435 1436static int 1437zio_issue_async(zio_t *zio) 1438{ 1439 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 1440 1441 return (ZIO_PIPELINE_STOP); 1442} 1443 1444void 1445zio_interrupt(zio_t *zio) 1446{ 1447 zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE); 1448} 1449 1450void 1451zio_delay_interrupt(zio_t *zio) 1452{ 1453 /* 1454 * The timeout_generic() function isn't defined in userspace, so 1455 * rather than trying to implement the function, the zio delay 1456 * functionality has been disabled for userspace builds. 1457 */ 1458 1459#ifdef _KERNEL 1460 /* 1461 * If io_target_timestamp is zero, then no delay has been registered 1462 * for this IO, thus jump to the end of this function and "skip" the 1463 * delay; issuing it directly to the zio layer. 1464 */ 1465 if (zio->io_target_timestamp != 0) { 1466 hrtime_t now = gethrtime(); 1467 1468 if (now >= zio->io_target_timestamp) { 1469 /* 1470 * This IO has already taken longer than the target 1471 * delay to complete, so we don't want to delay it 1472 * any longer; we "miss" the delay and issue it 1473 * directly to the zio layer. This is likely due to 1474 * the target latency being set to a value less than 1475 * the underlying hardware can satisfy (e.g. delay 1476 * set to 1ms, but the disks take 10ms to complete an 1477 * IO request). 1478 */ 1479 1480 DTRACE_PROBE2(zio__delay__miss, zio_t *, zio, 1481 hrtime_t, now); 1482 1483 zio_interrupt(zio); 1484 } else { 1485 hrtime_t diff = zio->io_target_timestamp - now; 1486 1487 DTRACE_PROBE3(zio__delay__hit, zio_t *, zio, 1488 hrtime_t, now, hrtime_t, diff); 1489 1490 (void) timeout_generic(CALLOUT_NORMAL, 1491 (void (*)(void *))zio_interrupt, zio, diff, 1, 0); 1492 } 1493 1494 return; 1495 } 1496#endif 1497 1498 DTRACE_PROBE1(zio__delay__skip, zio_t *, zio); 1499 zio_interrupt(zio); 1500} 1501 1502/* 1503 * Execute the I/O pipeline until one of the following occurs: 1504 * 1505 * (1) the I/O completes 1506 * (2) the pipeline stalls waiting for dependent child I/Os 1507 * (3) the I/O issues, so we're waiting for an I/O completion interrupt 1508 * (4) the I/O is delegated by vdev-level caching or aggregation 1509 * (5) the I/O is deferred due to vdev-level queueing 1510 * (6) the I/O is handed off to another thread. 1511 * 1512 * In all cases, the pipeline stops whenever there's no CPU work; it never 1513 * burns a thread in cv_wait(). 1514 * 1515 * There's no locking on io_stage because there's no legitimate way 1516 * for multiple threads to be attempting to process the same I/O. 1517 */ 1518static zio_pipe_stage_t *zio_pipeline[]; 1519 1520void 1521zio_execute(zio_t *zio) 1522{ 1523 zio->io_executor = curthread; 1524 1525 while (zio->io_stage < ZIO_STAGE_DONE) { 1526 enum zio_stage pipeline = zio->io_pipeline; 1527 enum zio_stage stage = zio->io_stage; 1528 int rv; 1529 1530 ASSERT(!MUTEX_HELD(&zio->io_lock)); 1531 ASSERT(ISP2(stage)); 1532 ASSERT(zio->io_stall == NULL); 1533 1534 do { 1535 stage <<= 1; 1536 } while ((stage & pipeline) == 0); 1537 1538 ASSERT(stage <= ZIO_STAGE_DONE); 1539 1540 /* 1541 * If we are in interrupt context and this pipeline stage 1542 * will grab a config lock that is held across I/O, 1543 * or may wait for an I/O that needs an interrupt thread 1544 * to complete, issue async to avoid deadlock. 1545 * 1546 * For VDEV_IO_START, we cut in line so that the io will 1547 * be sent to disk promptly. 1548 */ 1549 if ((stage & ZIO_BLOCKING_STAGES) && zio->io_vd == NULL && 1550 zio_taskq_member(zio, ZIO_TASKQ_INTERRUPT)) { 1551 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ? 1552 zio_requeue_io_start_cut_in_line : B_FALSE; 1553 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut); 1554 return; 1555 } 1556 1557 zio->io_stage = stage; 1558 rv = zio_pipeline[highbit64(stage) - 1](zio); 1559 1560 if (rv == ZIO_PIPELINE_STOP) 1561 return; 1562 1563 ASSERT(rv == ZIO_PIPELINE_CONTINUE); 1564 } 1565} 1566 1567/* 1568 * ========================================================================== 1569 * Initiate I/O, either sync or async 1570 * ========================================================================== 1571 */ 1572int 1573zio_wait(zio_t *zio) 1574{ 1575 int error; 1576 1577 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 1578 ASSERT(zio->io_executor == NULL); 1579 1580 zio->io_waiter = curthread; 1581 1582 zio_execute(zio); 1583 1584 mutex_enter(&zio->io_lock); 1585 while (zio->io_executor != NULL) 1586 cv_wait(&zio->io_cv, &zio->io_lock); 1587 mutex_exit(&zio->io_lock); 1588 1589 error = zio->io_error; 1590 zio_destroy(zio); 1591 1592 return (error); 1593} 1594 1595void 1596zio_nowait(zio_t *zio) 1597{ 1598 ASSERT(zio->io_executor == NULL); 1599 1600 if (zio->io_child_type == ZIO_CHILD_LOGICAL && 1601 zio_unique_parent(zio) == NULL) { 1602 /* 1603 * This is a logical async I/O with no parent to wait for it. 1604 * We add it to the spa_async_root_zio "Godfather" I/O which 1605 * will ensure they complete prior to unloading the pool. 1606 */ 1607 spa_t *spa = zio->io_spa; 1608 1609 zio_add_child(spa->spa_async_zio_root[CPU_SEQID], zio); 1610 } 1611 1612 zio_execute(zio); 1613} 1614 1615/* 1616 * ========================================================================== 1617 * Reexecute or suspend/resume failed I/O 1618 * ========================================================================== 1619 */ 1620 1621static void 1622zio_reexecute(zio_t *pio) 1623{ 1624 zio_t *cio, *cio_next; 1625 1626 ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL); 1627 ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN); 1628 ASSERT(pio->io_gang_leader == NULL); 1629 ASSERT(pio->io_gang_tree == NULL); 1630 1631 pio->io_flags = pio->io_orig_flags; 1632 pio->io_stage = pio->io_orig_stage; 1633 pio->io_pipeline = pio->io_orig_pipeline; 1634 pio->io_reexecute = 0; 1635 pio->io_flags |= ZIO_FLAG_REEXECUTED; 1636 pio->io_error = 0; 1637 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1638 pio->io_state[w] = 0; 1639 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 1640 pio->io_child_error[c] = 0; 1641 1642 if (IO_IS_ALLOCATING(pio)) 1643 BP_ZERO(pio->io_bp); 1644 1645 /* 1646 * As we reexecute pio's children, new children could be created. 1647 * New children go to the head of pio's io_child_list, however, 1648 * so we will (correctly) not reexecute them. The key is that 1649 * the remainder of pio's io_child_list, from 'cio_next' onward, 1650 * cannot be affected by any side effects of reexecuting 'cio'. 1651 */ 1652 for (cio = zio_walk_children(pio); cio != NULL; cio = cio_next) { 1653 cio_next = zio_walk_children(pio); 1654 mutex_enter(&pio->io_lock); 1655 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1656 pio->io_children[cio->io_child_type][w]++; 1657 mutex_exit(&pio->io_lock); 1658 zio_reexecute(cio); 1659 } 1660 1661 /* 1662 * Now that all children have been reexecuted, execute the parent. 1663 * We don't reexecute "The Godfather" I/O here as it's the 1664 * responsibility of the caller to wait on him. 1665 */ 1666 if (!(pio->io_flags & ZIO_FLAG_GODFATHER)) 1667 zio_execute(pio); 1668} 1669 1670void 1671zio_suspend(spa_t *spa, zio_t *zio) 1672{ 1673 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC) 1674 fm_panic("Pool '%s' has encountered an uncorrectable I/O " 1675 "failure and the failure mode property for this pool " 1676 "is set to panic.", spa_name(spa)); 1677 1678 zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL, NULL, 0, 0); 1679 1680 mutex_enter(&spa->spa_suspend_lock); 1681 1682 if (spa->spa_suspend_zio_root == NULL) 1683 spa->spa_suspend_zio_root = zio_root(spa, NULL, NULL, 1684 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | 1685 ZIO_FLAG_GODFATHER); 1686 1687 spa->spa_suspended = B_TRUE; 1688 1689 if (zio != NULL) { 1690 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 1691 ASSERT(zio != spa->spa_suspend_zio_root); 1692 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1693 ASSERT(zio_unique_parent(zio) == NULL); 1694 ASSERT(zio->io_stage == ZIO_STAGE_DONE); 1695 zio_add_child(spa->spa_suspend_zio_root, zio); 1696 } 1697 1698 mutex_exit(&spa->spa_suspend_lock); 1699} 1700 1701int 1702zio_resume(spa_t *spa) 1703{ 1704 zio_t *pio; 1705 1706 /* 1707 * Reexecute all previously suspended i/o. 1708 */ 1709 mutex_enter(&spa->spa_suspend_lock); 1710 spa->spa_suspended = B_FALSE; 1711 cv_broadcast(&spa->spa_suspend_cv); 1712 pio = spa->spa_suspend_zio_root; 1713 spa->spa_suspend_zio_root = NULL; 1714 mutex_exit(&spa->spa_suspend_lock); 1715 1716 if (pio == NULL) 1717 return (0); 1718 1719 zio_reexecute(pio); 1720 return (zio_wait(pio)); 1721} 1722 1723void 1724zio_resume_wait(spa_t *spa) 1725{ 1726 mutex_enter(&spa->spa_suspend_lock); 1727 while (spa_suspended(spa)) 1728 cv_wait(&spa->spa_suspend_cv, &spa->spa_suspend_lock); 1729 mutex_exit(&spa->spa_suspend_lock); 1730} 1731 1732/* 1733 * ========================================================================== 1734 * Gang blocks. 1735 * 1736 * A gang block is a collection of small blocks that looks to the DMU 1737 * like one large block. When zio_dva_allocate() cannot find a block 1738 * of the requested size, due to either severe fragmentation or the pool 1739 * being nearly full, it calls zio_write_gang_block() to construct the 1740 * block from smaller fragments. 1741 * 1742 * A gang block consists of a gang header (zio_gbh_phys_t) and up to 1743 * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like 1744 * an indirect block: it's an array of block pointers. It consumes 1745 * only one sector and hence is allocatable regardless of fragmentation. 1746 * The gang header's bps point to its gang members, which hold the data. 1747 * 1748 * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg> 1749 * as the verifier to ensure uniqueness of the SHA256 checksum. 1750 * Critically, the gang block bp's blk_cksum is the checksum of the data, 1751 * not the gang header. This ensures that data block signatures (needed for 1752 * deduplication) are independent of how the block is physically stored. 1753 * 1754 * Gang blocks can be nested: a gang member may itself be a gang block. 1755 * Thus every gang block is a tree in which root and all interior nodes are 1756 * gang headers, and the leaves are normal blocks that contain user data. 1757 * The root of the gang tree is called the gang leader. 1758 * 1759 * To perform any operation (read, rewrite, free, claim) on a gang block, 1760 * zio_gang_assemble() first assembles the gang tree (minus data leaves) 1761 * in the io_gang_tree field of the original logical i/o by recursively 1762 * reading the gang leader and all gang headers below it. This yields 1763 * an in-core tree containing the contents of every gang header and the 1764 * bps for every constituent of the gang block. 1765 * 1766 * With the gang tree now assembled, zio_gang_issue() just walks the gang tree 1767 * and invokes a callback on each bp. To free a gang block, zio_gang_issue() 1768 * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp. 1769 * zio_claim_gang() provides a similarly trivial wrapper for zio_claim(). 1770 * zio_read_gang() is a wrapper around zio_read() that omits reading gang 1771 * headers, since we already have those in io_gang_tree. zio_rewrite_gang() 1772 * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite() 1773 * of the gang header plus zio_checksum_compute() of the data to update the 1774 * gang header's blk_cksum as described above. 1775 * 1776 * The two-phase assemble/issue model solves the problem of partial failure -- 1777 * what if you'd freed part of a gang block but then couldn't read the 1778 * gang header for another part? Assembling the entire gang tree first 1779 * ensures that all the necessary gang header I/O has succeeded before 1780 * starting the actual work of free, claim, or write. Once the gang tree 1781 * is assembled, free and claim are in-memory operations that cannot fail. 1782 * 1783 * In the event that a gang write fails, zio_dva_unallocate() walks the 1784 * gang tree to immediately free (i.e. insert back into the space map) 1785 * everything we've allocated. This ensures that we don't get ENOSPC 1786 * errors during repeated suspend/resume cycles due to a flaky device. 1787 * 1788 * Gang rewrites only happen during sync-to-convergence. If we can't assemble 1789 * the gang tree, we won't modify the block, so we can safely defer the free 1790 * (knowing that the block is still intact). If we *can* assemble the gang 1791 * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free 1792 * each constituent bp and we can allocate a new block on the next sync pass. 1793 * 1794 * In all cases, the gang tree allows complete recovery from partial failure. 1795 * ========================================================================== 1796 */ 1797 1798static zio_t * 1799zio_read_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1800{ 1801 if (gn != NULL) 1802 return (pio); 1803 1804 return (zio_read(pio, pio->io_spa, bp, data, BP_GET_PSIZE(bp), 1805 NULL, NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 1806 &pio->io_bookmark)); 1807} 1808 1809zio_t * 1810zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1811{ 1812 zio_t *zio; 1813 1814 if (gn != NULL) { 1815 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1816 gn->gn_gbh, SPA_GANGBLOCKSIZE, NULL, NULL, pio->io_priority, 1817 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1818 /* 1819 * As we rewrite each gang header, the pipeline will compute 1820 * a new gang block header checksum for it; but no one will 1821 * compute a new data checksum, so we do that here. The one 1822 * exception is the gang leader: the pipeline already computed 1823 * its data checksum because that stage precedes gang assembly. 1824 * (Presently, nothing actually uses interior data checksums; 1825 * this is just good hygiene.) 1826 */ 1827 if (gn != pio->io_gang_leader->io_gang_tree) { 1828 zio_checksum_compute(zio, BP_GET_CHECKSUM(bp), 1829 data, BP_GET_PSIZE(bp)); 1830 } 1831 /* 1832 * If we are here to damage data for testing purposes, 1833 * leave the GBH alone so that we can detect the damage. 1834 */ 1835 if (pio->io_gang_leader->io_flags & ZIO_FLAG_INDUCE_DAMAGE) 1836 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 1837 } else { 1838 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1839 data, BP_GET_PSIZE(bp), NULL, NULL, pio->io_priority, 1840 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1841 } 1842 1843 return (zio); 1844} 1845 1846/* ARGSUSED */ 1847zio_t * 1848zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1849{ 1850 return (zio_free_sync(pio, pio->io_spa, pio->io_txg, bp, 1851 BP_IS_GANG(bp) ? SPA_GANGBLOCKSIZE : BP_GET_PSIZE(bp), 1852 ZIO_GANG_CHILD_FLAGS(pio))); 1853} 1854 1855/* ARGSUSED */ 1856zio_t * 1857zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1858{ 1859 return (zio_claim(pio, pio->io_spa, pio->io_txg, bp, 1860 NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio))); 1861} 1862 1863static zio_gang_issue_func_t *zio_gang_issue_func[ZIO_TYPES] = { 1864 NULL, 1865 zio_read_gang, 1866 zio_rewrite_gang, 1867 zio_free_gang, 1868 zio_claim_gang, 1869 NULL 1870}; 1871 1872static void zio_gang_tree_assemble_done(zio_t *zio); 1873 1874static zio_gang_node_t * 1875zio_gang_node_alloc(zio_gang_node_t **gnpp) 1876{ 1877 zio_gang_node_t *gn; 1878 1879 ASSERT(*gnpp == NULL); 1880 1881 gn = kmem_zalloc(sizeof (*gn), KM_SLEEP); 1882 gn->gn_gbh = zio_buf_alloc(SPA_GANGBLOCKSIZE); 1883 *gnpp = gn; 1884 1885 return (gn); 1886} 1887 1888static void 1889zio_gang_node_free(zio_gang_node_t **gnpp) 1890{ 1891 zio_gang_node_t *gn = *gnpp; 1892 1893 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 1894 ASSERT(gn->gn_child[g] == NULL); 1895 1896 zio_buf_free(gn->gn_gbh, SPA_GANGBLOCKSIZE); 1897 kmem_free(gn, sizeof (*gn)); 1898 *gnpp = NULL; 1899} 1900 1901static void 1902zio_gang_tree_free(zio_gang_node_t **gnpp) 1903{ 1904 zio_gang_node_t *gn = *gnpp; 1905 1906 if (gn == NULL) 1907 return; 1908 1909 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 1910 zio_gang_tree_free(&gn->gn_child[g]); 1911 1912 zio_gang_node_free(gnpp); 1913} 1914 1915static void 1916zio_gang_tree_assemble(zio_t *gio, blkptr_t *bp, zio_gang_node_t **gnpp) 1917{ 1918 zio_gang_node_t *gn = zio_gang_node_alloc(gnpp); 1919 1920 ASSERT(gio->io_gang_leader == gio); 1921 ASSERT(BP_IS_GANG(bp)); 1922 1923 zio_nowait(zio_read(gio, gio->io_spa, bp, gn->gn_gbh, 1924 SPA_GANGBLOCKSIZE, zio_gang_tree_assemble_done, gn, 1925 gio->io_priority, ZIO_GANG_CHILD_FLAGS(gio), &gio->io_bookmark)); 1926} 1927 1928static void 1929zio_gang_tree_assemble_done(zio_t *zio) 1930{ 1931 zio_t *gio = zio->io_gang_leader; 1932 zio_gang_node_t *gn = zio->io_private; 1933 blkptr_t *bp = zio->io_bp; 1934 1935 ASSERT(gio == zio_unique_parent(zio)); 1936 ASSERT(zio->io_child_count == 0); 1937 1938 if (zio->io_error) 1939 return; 1940 1941 if (BP_SHOULD_BYTESWAP(bp)) 1942 byteswap_uint64_array(zio->io_data, zio->io_size); 1943 1944 ASSERT(zio->io_data == gn->gn_gbh); 1945 ASSERT(zio->io_size == SPA_GANGBLOCKSIZE); 1946 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 1947 1948 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 1949 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 1950 if (!BP_IS_GANG(gbp)) 1951 continue; 1952 zio_gang_tree_assemble(gio, gbp, &gn->gn_child[g]); 1953 } 1954} 1955 1956static void 1957zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, void *data) 1958{ 1959 zio_t *gio = pio->io_gang_leader; 1960 zio_t *zio; 1961 1962 ASSERT(BP_IS_GANG(bp) == !!gn); 1963 ASSERT(BP_GET_CHECKSUM(bp) == BP_GET_CHECKSUM(gio->io_bp)); 1964 ASSERT(BP_GET_LSIZE(bp) == BP_GET_PSIZE(bp) || gn == gio->io_gang_tree); 1965 1966 /* 1967 * If you're a gang header, your data is in gn->gn_gbh. 1968 * If you're a gang member, your data is in 'data' and gn == NULL. 1969 */ 1970 zio = zio_gang_issue_func[gio->io_type](pio, bp, gn, data); 1971 1972 if (gn != NULL) { 1973 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 1974 1975 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 1976 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 1977 if (BP_IS_HOLE(gbp)) 1978 continue; 1979 zio_gang_tree_issue(zio, gn->gn_child[g], gbp, data); 1980 data = (char *)data + BP_GET_PSIZE(gbp); 1981 } 1982 } 1983 1984 if (gn == gio->io_gang_tree && gio->io_data != NULL) 1985 ASSERT3P((char *)gio->io_data + gio->io_size, ==, data); 1986 1987 if (zio != pio) 1988 zio_nowait(zio); 1989} 1990 1991static int 1992zio_gang_assemble(zio_t *zio) 1993{ 1994 blkptr_t *bp = zio->io_bp; 1995 1996 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == NULL); 1997 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 1998 1999 zio->io_gang_leader = zio; 2000 2001 zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree); 2002 2003 return (ZIO_PIPELINE_CONTINUE); 2004} 2005 2006static int 2007zio_gang_issue(zio_t *zio) 2008{ 2009 blkptr_t *bp = zio->io_bp; 2010 2011 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE)) 2012 return (ZIO_PIPELINE_STOP); 2013 2014 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio); 2015 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2016 2017 if (zio->io_child_error[ZIO_CHILD_GANG] == 0) 2018 zio_gang_tree_issue(zio, zio->io_gang_tree, bp, zio->io_data); 2019 else 2020 zio_gang_tree_free(&zio->io_gang_tree); 2021 2022 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2023 2024 return (ZIO_PIPELINE_CONTINUE); 2025} 2026 2027static void 2028zio_write_gang_member_ready(zio_t *zio) 2029{ 2030 zio_t *pio = zio_unique_parent(zio); 2031 zio_t *gio = zio->io_gang_leader; 2032 dva_t *cdva = zio->io_bp->blk_dva; 2033 dva_t *pdva = pio->io_bp->blk_dva; 2034 uint64_t asize; 2035 2036 if (BP_IS_HOLE(zio->io_bp)) 2037 return; 2038 2039 ASSERT(BP_IS_HOLE(&zio->io_bp_orig)); 2040 2041 ASSERT(zio->io_child_type == ZIO_CHILD_GANG); 2042 ASSERT3U(zio->io_prop.zp_copies, ==, gio->io_prop.zp_copies); 2043 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp)); 2044 ASSERT3U(pio->io_prop.zp_copies, <=, BP_GET_NDVAS(pio->io_bp)); 2045 ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp)); 2046 2047 mutex_enter(&pio->io_lock); 2048 for (int d = 0; d < BP_GET_NDVAS(zio->io_bp); d++) { 2049 ASSERT(DVA_GET_GANG(&pdva[d])); 2050 asize = DVA_GET_ASIZE(&pdva[d]); 2051 asize += DVA_GET_ASIZE(&cdva[d]); 2052 DVA_SET_ASIZE(&pdva[d], asize); 2053 } 2054 mutex_exit(&pio->io_lock); 2055} 2056 2057static int 2058zio_write_gang_block(zio_t *pio) 2059{ 2060 spa_t *spa = pio->io_spa; 2061 blkptr_t *bp = pio->io_bp; 2062 zio_t *gio = pio->io_gang_leader; 2063 zio_t *zio; 2064 zio_gang_node_t *gn, **gnpp; 2065 zio_gbh_phys_t *gbh; 2066 uint64_t txg = pio->io_txg; 2067 uint64_t resid = pio->io_size; 2068 uint64_t lsize; 2069 int copies = gio->io_prop.zp_copies; 2070 int gbh_copies = MIN(copies + 1, spa_max_replication(spa)); 2071 zio_prop_t zp; 2072 int error; 2073 2074 error = metaslab_alloc(spa, spa_normal_class(spa), SPA_GANGBLOCKSIZE, 2075 bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp, 2076 METASLAB_HINTBP_FAVOR | METASLAB_GANG_HEADER); 2077 if (error) { 2078 pio->io_error = error; 2079 return (ZIO_PIPELINE_CONTINUE); 2080 } 2081 2082 if (pio == gio) { 2083 gnpp = &gio->io_gang_tree; 2084 } else { 2085 gnpp = pio->io_private; 2086 ASSERT(pio->io_ready == zio_write_gang_member_ready); 2087 } 2088 2089 gn = zio_gang_node_alloc(gnpp); 2090 gbh = gn->gn_gbh; 2091 bzero(gbh, SPA_GANGBLOCKSIZE); 2092 2093 /* 2094 * Create the gang header. 2095 */ 2096 zio = zio_rewrite(pio, spa, txg, bp, gbh, SPA_GANGBLOCKSIZE, NULL, NULL, 2097 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 2098 2099 /* 2100 * Create and nowait the gang children. 2101 */ 2102 for (int g = 0; resid != 0; resid -= lsize, g++) { 2103 lsize = P2ROUNDUP(resid / (SPA_GBH_NBLKPTRS - g), 2104 SPA_MINBLOCKSIZE); 2105 ASSERT(lsize >= SPA_MINBLOCKSIZE && lsize <= resid); 2106 2107 zp.zp_checksum = gio->io_prop.zp_checksum; 2108 zp.zp_compress = ZIO_COMPRESS_OFF; 2109 zp.zp_type = DMU_OT_NONE; 2110 zp.zp_level = 0; 2111 zp.zp_copies = gio->io_prop.zp_copies; 2112 zp.zp_dedup = B_FALSE; 2113 zp.zp_dedup_verify = B_FALSE; 2114 zp.zp_nopwrite = B_FALSE; 2115 2116 zio_nowait(zio_write(zio, spa, txg, &gbh->zg_blkptr[g], 2117 (char *)pio->io_data + (pio->io_size - resid), lsize, &zp, 2118 zio_write_gang_member_ready, NULL, NULL, &gn->gn_child[g], 2119 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 2120 &pio->io_bookmark)); 2121 } 2122 2123 /* 2124 * Set pio's pipeline to just wait for zio to finish. 2125 */ 2126 pio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2127 2128 zio_nowait(zio); 2129 2130 return (ZIO_PIPELINE_CONTINUE); 2131} 2132 2133/* 2134 * The zio_nop_write stage in the pipeline determines if allocating a 2135 * new bp is necessary. The nopwrite feature can handle writes in 2136 * either syncing or open context (i.e. zil writes) and as a result is 2137 * mutually exclusive with dedup. 2138 * 2139 * By leveraging a cryptographically secure checksum, such as SHA256, we 2140 * can compare the checksums of the new data and the old to determine if 2141 * allocating a new block is required. Note that our requirements for 2142 * cryptographic strength are fairly weak: there can't be any accidental 2143 * hash collisions, but we don't need to be secure against intentional 2144 * (malicious) collisions. To trigger a nopwrite, you have to be able 2145 * to write the file to begin with, and triggering an incorrect (hash 2146 * collision) nopwrite is no worse than simply writing to the file. 2147 * That said, there are no known attacks against the checksum algorithms 2148 * used for nopwrite, assuming that the salt and the checksums 2149 * themselves remain secret. 2150 */ 2151static int 2152zio_nop_write(zio_t *zio) 2153{ 2154 blkptr_t *bp = zio->io_bp; 2155 blkptr_t *bp_orig = &zio->io_bp_orig; 2156 zio_prop_t *zp = &zio->io_prop; 2157 2158 ASSERT(BP_GET_LEVEL(bp) == 0); 2159 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 2160 ASSERT(zp->zp_nopwrite); 2161 ASSERT(!zp->zp_dedup); 2162 ASSERT(zio->io_bp_override == NULL); 2163 ASSERT(IO_IS_ALLOCATING(zio)); 2164 2165 /* 2166 * Check to see if the original bp and the new bp have matching 2167 * characteristics (i.e. same checksum, compression algorithms, etc). 2168 * If they don't then just continue with the pipeline which will 2169 * allocate a new bp. 2170 */ 2171 if (BP_IS_HOLE(bp_orig) || 2172 !(zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_flags & 2173 ZCHECKSUM_FLAG_NOPWRITE) || 2174 BP_GET_CHECKSUM(bp) != BP_GET_CHECKSUM(bp_orig) || 2175 BP_GET_COMPRESS(bp) != BP_GET_COMPRESS(bp_orig) || 2176 BP_GET_DEDUP(bp) != BP_GET_DEDUP(bp_orig) || 2177 zp->zp_copies != BP_GET_NDVAS(bp_orig)) 2178 return (ZIO_PIPELINE_CONTINUE); 2179 2180 /* 2181 * If the checksums match then reset the pipeline so that we 2182 * avoid allocating a new bp and issuing any I/O. 2183 */ 2184 if (ZIO_CHECKSUM_EQUAL(bp->blk_cksum, bp_orig->blk_cksum)) { 2185 ASSERT(zio_checksum_table[zp->zp_checksum].ci_flags & 2186 ZCHECKSUM_FLAG_NOPWRITE); 2187 ASSERT3U(BP_GET_PSIZE(bp), ==, BP_GET_PSIZE(bp_orig)); 2188 ASSERT3U(BP_GET_LSIZE(bp), ==, BP_GET_LSIZE(bp_orig)); 2189 ASSERT(zp->zp_compress != ZIO_COMPRESS_OFF); 2190 ASSERT(bcmp(&bp->blk_prop, &bp_orig->blk_prop, 2191 sizeof (uint64_t)) == 0); 2192 2193 *bp = *bp_orig; 2194 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2195 zio->io_flags |= ZIO_FLAG_NOPWRITE; 2196 } 2197 2198 return (ZIO_PIPELINE_CONTINUE); 2199} 2200 2201/* 2202 * ========================================================================== 2203 * Dedup 2204 * ========================================================================== 2205 */ 2206static void 2207zio_ddt_child_read_done(zio_t *zio) 2208{ 2209 blkptr_t *bp = zio->io_bp; 2210 ddt_entry_t *dde = zio->io_private; 2211 ddt_phys_t *ddp; 2212 zio_t *pio = zio_unique_parent(zio); 2213 2214 mutex_enter(&pio->io_lock); 2215 ddp = ddt_phys_select(dde, bp); 2216 if (zio->io_error == 0) 2217 ddt_phys_clear(ddp); /* this ddp doesn't need repair */ 2218 if (zio->io_error == 0 && dde->dde_repair_data == NULL) 2219 dde->dde_repair_data = zio->io_data; 2220 else 2221 zio_buf_free(zio->io_data, zio->io_size); 2222 mutex_exit(&pio->io_lock); 2223} 2224 2225static int 2226zio_ddt_read_start(zio_t *zio) 2227{ 2228 blkptr_t *bp = zio->io_bp; 2229 2230 ASSERT(BP_GET_DEDUP(bp)); 2231 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 2232 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2233 2234 if (zio->io_child_error[ZIO_CHILD_DDT]) { 2235 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2236 ddt_entry_t *dde = ddt_repair_start(ddt, bp); 2237 ddt_phys_t *ddp = dde->dde_phys; 2238 ddt_phys_t *ddp_self = ddt_phys_select(dde, bp); 2239 blkptr_t blk; 2240 2241 ASSERT(zio->io_vsd == NULL); 2242 zio->io_vsd = dde; 2243 2244 if (ddp_self == NULL) 2245 return (ZIO_PIPELINE_CONTINUE); 2246 2247 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { 2248 if (ddp->ddp_phys_birth == 0 || ddp == ddp_self) 2249 continue; 2250 ddt_bp_create(ddt->ddt_checksum, &dde->dde_key, ddp, 2251 &blk); 2252 zio_nowait(zio_read(zio, zio->io_spa, &blk, 2253 zio_buf_alloc(zio->io_size), zio->io_size, 2254 zio_ddt_child_read_done, dde, zio->io_priority, 2255 ZIO_DDT_CHILD_FLAGS(zio) | ZIO_FLAG_DONT_PROPAGATE, 2256 &zio->io_bookmark)); 2257 } 2258 return (ZIO_PIPELINE_CONTINUE); 2259 } 2260 2261 zio_nowait(zio_read(zio, zio->io_spa, bp, 2262 zio->io_data, zio->io_size, NULL, NULL, zio->io_priority, 2263 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark)); 2264 2265 return (ZIO_PIPELINE_CONTINUE); 2266} 2267 2268static int 2269zio_ddt_read_done(zio_t *zio) 2270{ 2271 blkptr_t *bp = zio->io_bp; 2272 2273 if (zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE)) 2274 return (ZIO_PIPELINE_STOP); 2275 2276 ASSERT(BP_GET_DEDUP(bp)); 2277 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 2278 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2279 2280 if (zio->io_child_error[ZIO_CHILD_DDT]) { 2281 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2282 ddt_entry_t *dde = zio->io_vsd; 2283 if (ddt == NULL) { 2284 ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE); 2285 return (ZIO_PIPELINE_CONTINUE); 2286 } 2287 if (dde == NULL) { 2288 zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1; 2289 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 2290 return (ZIO_PIPELINE_STOP); 2291 } 2292 if (dde->dde_repair_data != NULL) { 2293 bcopy(dde->dde_repair_data, zio->io_data, zio->io_size); 2294 zio->io_child_error[ZIO_CHILD_DDT] = 0; 2295 } 2296 ddt_repair_done(ddt, dde); 2297 zio->io_vsd = NULL; 2298 } 2299 2300 ASSERT(zio->io_vsd == NULL); 2301 2302 return (ZIO_PIPELINE_CONTINUE); 2303} 2304 2305static boolean_t 2306zio_ddt_collision(zio_t *zio, ddt_t *ddt, ddt_entry_t *dde) 2307{ 2308 spa_t *spa = zio->io_spa; 2309 2310 /* 2311 * Note: we compare the original data, not the transformed data, 2312 * because when zio->io_bp is an override bp, we will not have 2313 * pushed the I/O transforms. That's an important optimization 2314 * because otherwise we'd compress/encrypt all dmu_sync() data twice. 2315 */ 2316 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 2317 zio_t *lio = dde->dde_lead_zio[p]; 2318 2319 if (lio != NULL) { 2320 return (lio->io_orig_size != zio->io_orig_size || 2321 bcmp(zio->io_orig_data, lio->io_orig_data, 2322 zio->io_orig_size) != 0); 2323 } 2324 } 2325 2326 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 2327 ddt_phys_t *ddp = &dde->dde_phys[p]; 2328 2329 if (ddp->ddp_phys_birth != 0) { 2330 arc_buf_t *abuf = NULL; 2331 arc_flags_t aflags = ARC_FLAG_WAIT; 2332 blkptr_t blk = *zio->io_bp; 2333 int error; 2334 2335 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth); 2336 2337 ddt_exit(ddt); 2338 2339 error = arc_read(NULL, spa, &blk, 2340 arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ, 2341 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, 2342 &aflags, &zio->io_bookmark); 2343 2344 if (error == 0) { 2345 if (arc_buf_size(abuf) != zio->io_orig_size || 2346 bcmp(abuf->b_data, zio->io_orig_data, 2347 zio->io_orig_size) != 0) 2348 error = SET_ERROR(EEXIST); 2349 VERIFY(arc_buf_remove_ref(abuf, &abuf)); 2350 } 2351 2352 ddt_enter(ddt); 2353 return (error != 0); 2354 } 2355 } 2356 2357 return (B_FALSE); 2358} 2359 2360static void 2361zio_ddt_child_write_ready(zio_t *zio) 2362{ 2363 int p = zio->io_prop.zp_copies; 2364 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 2365 ddt_entry_t *dde = zio->io_private; 2366 ddt_phys_t *ddp = &dde->dde_phys[p]; 2367 zio_t *pio; 2368 2369 if (zio->io_error) 2370 return; 2371 2372 ddt_enter(ddt); 2373 2374 ASSERT(dde->dde_lead_zio[p] == zio); 2375 2376 ddt_phys_fill(ddp, zio->io_bp); 2377 2378 while ((pio = zio_walk_parents(zio)) != NULL) 2379 ddt_bp_fill(ddp, pio->io_bp, zio->io_txg); 2380 2381 ddt_exit(ddt); 2382} 2383 2384static void 2385zio_ddt_child_write_done(zio_t *zio) 2386{ 2387 int p = zio->io_prop.zp_copies; 2388 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 2389 ddt_entry_t *dde = zio->io_private; 2390 ddt_phys_t *ddp = &dde->dde_phys[p]; 2391 2392 ddt_enter(ddt); 2393 2394 ASSERT(ddp->ddp_refcnt == 0); 2395 ASSERT(dde->dde_lead_zio[p] == zio); 2396 dde->dde_lead_zio[p] = NULL; 2397 2398 if (zio->io_error == 0) { 2399 while (zio_walk_parents(zio) != NULL) 2400 ddt_phys_addref(ddp); 2401 } else { 2402 ddt_phys_clear(ddp); 2403 } 2404 2405 ddt_exit(ddt); 2406} 2407 2408static void 2409zio_ddt_ditto_write_done(zio_t *zio) 2410{ 2411 int p = DDT_PHYS_DITTO; 2412 zio_prop_t *zp = &zio->io_prop; 2413 blkptr_t *bp = zio->io_bp; 2414 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2415 ddt_entry_t *dde = zio->io_private; 2416 ddt_phys_t *ddp = &dde->dde_phys[p]; 2417 ddt_key_t *ddk = &dde->dde_key; 2418 2419 ddt_enter(ddt); 2420 2421 ASSERT(ddp->ddp_refcnt == 0); 2422 ASSERT(dde->dde_lead_zio[p] == zio); 2423 dde->dde_lead_zio[p] = NULL; 2424 2425 if (zio->io_error == 0) { 2426 ASSERT(ZIO_CHECKSUM_EQUAL(bp->blk_cksum, ddk->ddk_cksum)); 2427 ASSERT(zp->zp_copies < SPA_DVAS_PER_BP); 2428 ASSERT(zp->zp_copies == BP_GET_NDVAS(bp) - BP_IS_GANG(bp)); 2429 if (ddp->ddp_phys_birth != 0) 2430 ddt_phys_free(ddt, ddk, ddp, zio->io_txg); 2431 ddt_phys_fill(ddp, bp); 2432 } 2433 2434 ddt_exit(ddt); 2435} 2436 2437static int 2438zio_ddt_write(zio_t *zio) 2439{ 2440 spa_t *spa = zio->io_spa; 2441 blkptr_t *bp = zio->io_bp; 2442 uint64_t txg = zio->io_txg; 2443 zio_prop_t *zp = &zio->io_prop; 2444 int p = zp->zp_copies; 2445 int ditto_copies; 2446 zio_t *cio = NULL; 2447 zio_t *dio = NULL; 2448 ddt_t *ddt = ddt_select(spa, bp); 2449 ddt_entry_t *dde; 2450 ddt_phys_t *ddp; 2451 2452 ASSERT(BP_GET_DEDUP(bp)); 2453 ASSERT(BP_GET_CHECKSUM(bp) == zp->zp_checksum); 2454 ASSERT(BP_IS_HOLE(bp) || zio->io_bp_override); 2455 2456 ddt_enter(ddt); 2457 dde = ddt_lookup(ddt, bp, B_TRUE); 2458 ddp = &dde->dde_phys[p]; 2459 2460 if (zp->zp_dedup_verify && zio_ddt_collision(zio, ddt, dde)) { 2461 /* 2462 * If we're using a weak checksum, upgrade to a strong checksum 2463 * and try again. If we're already using a strong checksum, 2464 * we can't resolve it, so just convert to an ordinary write. 2465 * (And automatically e-mail a paper to Nature?) 2466 */ 2467 if (!(zio_checksum_table[zp->zp_checksum].ci_flags & 2468 ZCHECKSUM_FLAG_DEDUP)) { 2469 zp->zp_checksum = spa_dedup_checksum(spa); 2470 zio_pop_transforms(zio); 2471 zio->io_stage = ZIO_STAGE_OPEN; 2472 BP_ZERO(bp); 2473 } else { 2474 zp->zp_dedup = B_FALSE; 2475 } 2476 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2477 ddt_exit(ddt); 2478 return (ZIO_PIPELINE_CONTINUE); 2479 } 2480 2481 ditto_copies = ddt_ditto_copies_needed(ddt, dde, ddp); 2482 ASSERT(ditto_copies < SPA_DVAS_PER_BP); 2483 2484 if (ditto_copies > ddt_ditto_copies_present(dde) && 2485 dde->dde_lead_zio[DDT_PHYS_DITTO] == NULL) { 2486 zio_prop_t czp = *zp; 2487 2488 czp.zp_copies = ditto_copies; 2489 2490 /* 2491 * If we arrived here with an override bp, we won't have run 2492 * the transform stack, so we won't have the data we need to 2493 * generate a child i/o. So, toss the override bp and restart. 2494 * This is safe, because using the override bp is just an 2495 * optimization; and it's rare, so the cost doesn't matter. 2496 */ 2497 if (zio->io_bp_override) { 2498 zio_pop_transforms(zio); 2499 zio->io_stage = ZIO_STAGE_OPEN; 2500 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2501 zio->io_bp_override = NULL; 2502 BP_ZERO(bp); 2503 ddt_exit(ddt); 2504 return (ZIO_PIPELINE_CONTINUE); 2505 } 2506 2507 dio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2508 zio->io_orig_size, &czp, NULL, NULL, 2509 zio_ddt_ditto_write_done, dde, zio->io_priority, 2510 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2511 2512 zio_push_transform(dio, zio->io_data, zio->io_size, 0, NULL); 2513 dde->dde_lead_zio[DDT_PHYS_DITTO] = dio; 2514 } 2515 2516 if (ddp->ddp_phys_birth != 0 || dde->dde_lead_zio[p] != NULL) { 2517 if (ddp->ddp_phys_birth != 0) 2518 ddt_bp_fill(ddp, bp, txg); 2519 if (dde->dde_lead_zio[p] != NULL) 2520 zio_add_child(zio, dde->dde_lead_zio[p]); 2521 else 2522 ddt_phys_addref(ddp); 2523 } else if (zio->io_bp_override) { 2524 ASSERT(bp->blk_birth == txg); 2525 ASSERT(BP_EQUAL(bp, zio->io_bp_override)); 2526 ddt_phys_fill(ddp, bp); 2527 ddt_phys_addref(ddp); 2528 } else { 2529 cio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2530 zio->io_orig_size, zp, zio_ddt_child_write_ready, NULL, 2531 zio_ddt_child_write_done, dde, zio->io_priority, 2532 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2533 2534 zio_push_transform(cio, zio->io_data, zio->io_size, 0, NULL); 2535 dde->dde_lead_zio[p] = cio; 2536 } 2537 2538 ddt_exit(ddt); 2539 2540 if (cio) 2541 zio_nowait(cio); 2542 if (dio) 2543 zio_nowait(dio); 2544 2545 return (ZIO_PIPELINE_CONTINUE); 2546} 2547 2548ddt_entry_t *freedde; /* for debugging */ 2549 2550static int 2551zio_ddt_free(zio_t *zio) 2552{ 2553 spa_t *spa = zio->io_spa; 2554 blkptr_t *bp = zio->io_bp; 2555 ddt_t *ddt = ddt_select(spa, bp); 2556 ddt_entry_t *dde; 2557 ddt_phys_t *ddp; 2558 2559 ASSERT(BP_GET_DEDUP(bp)); 2560 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2561 2562 ddt_enter(ddt); 2563 freedde = dde = ddt_lookup(ddt, bp, B_TRUE); 2564 ddp = ddt_phys_select(dde, bp); 2565 ddt_phys_decref(ddp); 2566 ddt_exit(ddt); 2567 2568 return (ZIO_PIPELINE_CONTINUE); 2569} 2570 2571/* 2572 * ========================================================================== 2573 * Allocate and free blocks 2574 * ========================================================================== 2575 */ 2576static int 2577zio_dva_allocate(zio_t *zio) 2578{ 2579 spa_t *spa = zio->io_spa; 2580 metaslab_class_t *mc = spa_normal_class(spa); 2581 blkptr_t *bp = zio->io_bp; 2582 int error; 2583 int flags = 0; 2584 2585 if (zio->io_gang_leader == NULL) { 2586 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2587 zio->io_gang_leader = zio; 2588 } 2589 2590 ASSERT(BP_IS_HOLE(bp)); 2591 ASSERT0(BP_GET_NDVAS(bp)); 2592 ASSERT3U(zio->io_prop.zp_copies, >, 0); 2593 ASSERT3U(zio->io_prop.zp_copies, <=, spa_max_replication(spa)); 2594 ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp)); 2595 2596 /* 2597 * The dump device does not support gang blocks so allocation on 2598 * behalf of the dump device (i.e. ZIO_FLAG_NODATA) must avoid 2599 * the "fast" gang feature. 2600 */ 2601 flags |= (zio->io_flags & ZIO_FLAG_NODATA) ? METASLAB_GANG_AVOID : 0; 2602 flags |= (zio->io_flags & ZIO_FLAG_GANG_CHILD) ? 2603 METASLAB_GANG_CHILD : 0; 2604 error = metaslab_alloc(spa, mc, zio->io_size, bp, 2605 zio->io_prop.zp_copies, zio->io_txg, NULL, flags); 2606 2607 if (error) { 2608 spa_dbgmsg(spa, "%s: metaslab allocation failure: zio %p, " 2609 "size %llu, error %d", spa_name(spa), zio, zio->io_size, 2610 error); 2611 if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE) 2612 return (zio_write_gang_block(zio)); 2613 zio->io_error = error; 2614 } 2615 2616 return (ZIO_PIPELINE_CONTINUE); 2617} 2618 2619static int 2620zio_dva_free(zio_t *zio) 2621{ 2622 metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE); 2623 2624 return (ZIO_PIPELINE_CONTINUE); 2625} 2626 2627static int 2628zio_dva_claim(zio_t *zio) 2629{ 2630 int error; 2631 2632 error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg); 2633 if (error) 2634 zio->io_error = error; 2635 2636 return (ZIO_PIPELINE_CONTINUE); 2637} 2638 2639/* 2640 * Undo an allocation. This is used by zio_done() when an I/O fails 2641 * and we want to give back the block we just allocated. 2642 * This handles both normal blocks and gang blocks. 2643 */ 2644static void 2645zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp) 2646{ 2647 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp)); 2648 ASSERT(zio->io_bp_override == NULL); 2649 2650 if (!BP_IS_HOLE(bp)) 2651 metaslab_free(zio->io_spa, bp, bp->blk_birth, B_TRUE); 2652 2653 if (gn != NULL) { 2654 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 2655 zio_dva_unallocate(zio, gn->gn_child[g], 2656 &gn->gn_gbh->zg_blkptr[g]); 2657 } 2658 } 2659} 2660 2661/* 2662 * Try to allocate an intent log block. Return 0 on success, errno on failure. 2663 */ 2664int 2665zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp, blkptr_t *old_bp, 2666 uint64_t size, boolean_t use_slog) 2667{ 2668 int error = 1; 2669 2670 ASSERT(txg > spa_syncing_txg(spa)); 2671 2672 /* 2673 * ZIL blocks are always contiguous (i.e. not gang blocks) so we 2674 * set the METASLAB_GANG_AVOID flag so that they don't "fast gang" 2675 * when allocating them. 2676 */ 2677 if (use_slog) { 2678 error = metaslab_alloc(spa, spa_log_class(spa), size, 2679 new_bp, 1, txg, old_bp, 2680 METASLAB_HINTBP_AVOID | METASLAB_GANG_AVOID); 2681 } 2682 2683 if (error) { 2684 error = metaslab_alloc(spa, spa_normal_class(spa), size, 2685 new_bp, 1, txg, old_bp, 2686 METASLAB_HINTBP_AVOID); 2687 } 2688 2689 if (error == 0) { 2690 BP_SET_LSIZE(new_bp, size); 2691 BP_SET_PSIZE(new_bp, size); 2692 BP_SET_COMPRESS(new_bp, ZIO_COMPRESS_OFF); 2693 BP_SET_CHECKSUM(new_bp, 2694 spa_version(spa) >= SPA_VERSION_SLIM_ZIL 2695 ? ZIO_CHECKSUM_ZILOG2 : ZIO_CHECKSUM_ZILOG); 2696 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG); 2697 BP_SET_LEVEL(new_bp, 0); 2698 BP_SET_DEDUP(new_bp, 0); 2699 BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER); 2700 } 2701 2702 return (error); 2703} 2704 2705/* 2706 * Free an intent log block. 2707 */ 2708void 2709zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp) 2710{ 2711 ASSERT(BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG); 2712 ASSERT(!BP_IS_GANG(bp)); 2713 2714 zio_free(spa, txg, bp); 2715} 2716 2717/* 2718 * ========================================================================== 2719 * Read, write and delete to physical devices 2720 * ========================================================================== 2721 */ 2722 2723 2724/* 2725 * Issue an I/O to the underlying vdev. Typically the issue pipeline 2726 * stops after this stage and will resume upon I/O completion. 2727 * However, there are instances where the vdev layer may need to 2728 * continue the pipeline when an I/O was not issued. Since the I/O 2729 * that was sent to the vdev layer might be different than the one 2730 * currently active in the pipeline (see vdev_queue_io()), we explicitly 2731 * force the underlying vdev layers to call either zio_execute() or 2732 * zio_interrupt() to ensure that the pipeline continues with the correct I/O. 2733 */ 2734static int 2735zio_vdev_io_start(zio_t *zio) 2736{ 2737 vdev_t *vd = zio->io_vd; 2738 uint64_t align; 2739 spa_t *spa = zio->io_spa; 2740 int ret; 2741 2742 ASSERT(zio->io_error == 0); 2743 ASSERT(zio->io_child_error[ZIO_CHILD_VDEV] == 0); 2744 2745 if (vd == NULL) { 2746 if (!(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 2747 spa_config_enter(spa, SCL_ZIO, zio, RW_READER); 2748 2749 /* 2750 * The mirror_ops handle multiple DVAs in a single BP. 2751 */ 2752 vdev_mirror_ops.vdev_op_io_start(zio); 2753 return (ZIO_PIPELINE_STOP); 2754 } 2755 2756 if (vd->vdev_ops->vdev_op_leaf && zio->io_type == ZIO_TYPE_FREE && 2757 zio->io_priority == ZIO_PRIORITY_NOW) { 2758 trim_map_free(vd, zio->io_offset, zio->io_size, zio->io_txg); 2759 return (ZIO_PIPELINE_CONTINUE); 2760 } 2761 2762 /* 2763 * We keep track of time-sensitive I/Os so that the scan thread 2764 * can quickly react to certain workloads. In particular, we care 2765 * about non-scrubbing, top-level reads and writes with the following 2766 * characteristics: 2767 * - synchronous writes of user data to non-slog devices 2768 * - any reads of user data 2769 * When these conditions are met, adjust the timestamp of spa_last_io 2770 * which allows the scan thread to adjust its workload accordingly. 2771 */ 2772 if (!(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && zio->io_bp != NULL && 2773 vd == vd->vdev_top && !vd->vdev_islog && 2774 zio->io_bookmark.zb_objset != DMU_META_OBJSET && 2775 zio->io_txg != spa_syncing_txg(spa)) { 2776 uint64_t old = spa->spa_last_io; 2777 uint64_t new = ddi_get_lbolt64(); 2778 if (old != new) 2779 (void) atomic_cas_64(&spa->spa_last_io, old, new); 2780 } 2781 2782 align = 1ULL << vd->vdev_top->vdev_ashift; 2783 2784 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL) && 2785 P2PHASE(zio->io_size, align) != 0) { 2786 /* Transform logical writes to be a full physical block size. */ 2787 uint64_t asize = P2ROUNDUP(zio->io_size, align); 2788 char *abuf = NULL; 2789 if (zio->io_type == ZIO_TYPE_READ || 2790 zio->io_type == ZIO_TYPE_WRITE) 2791 abuf = zio_buf_alloc(asize); 2792 ASSERT(vd == vd->vdev_top); 2793 if (zio->io_type == ZIO_TYPE_WRITE) { 2794 bcopy(zio->io_data, abuf, zio->io_size); 2795 bzero(abuf + zio->io_size, asize - zio->io_size); 2796 } 2797 zio_push_transform(zio, abuf, asize, abuf ? asize : 0, 2798 zio_subblock); 2799 } 2800 2801 /* 2802 * If this is not a physical io, make sure that it is properly aligned 2803 * before proceeding. 2804 */ 2805 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL)) { 2806 ASSERT0(P2PHASE(zio->io_offset, align)); 2807 ASSERT0(P2PHASE(zio->io_size, align)); 2808 } else { 2809 /* 2810 * For physical writes, we allow 512b aligned writes and assume 2811 * the device will perform a read-modify-write as necessary. 2812 */ 2813 ASSERT0(P2PHASE(zio->io_offset, SPA_MINBLOCKSIZE)); 2814 ASSERT0(P2PHASE(zio->io_size, SPA_MINBLOCKSIZE)); 2815 } 2816 2817 VERIFY(zio->io_type == ZIO_TYPE_READ || spa_writeable(spa)); 2818 2819 /* 2820 * If this is a repair I/O, and there's no self-healing involved -- 2821 * that is, we're just resilvering what we expect to resilver -- 2822 * then don't do the I/O unless zio's txg is actually in vd's DTL. 2823 * This prevents spurious resilvering with nested replication. 2824 * For example, given a mirror of mirrors, (A+B)+(C+D), if only 2825 * A is out of date, we'll read from C+D, then use the data to 2826 * resilver A+B -- but we don't actually want to resilver B, just A. 2827 * The top-level mirror has no way to know this, so instead we just 2828 * discard unnecessary repairs as we work our way down the vdev tree. 2829 * The same logic applies to any form of nested replication: 2830 * ditto + mirror, RAID-Z + replacing, etc. This covers them all. 2831 */ 2832 if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) && 2833 !(zio->io_flags & ZIO_FLAG_SELF_HEAL) && 2834 zio->io_txg != 0 && /* not a delegated i/o */ 2835 !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) { 2836 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 2837 zio_vdev_io_bypass(zio); 2838 return (ZIO_PIPELINE_CONTINUE); 2839 } 2840 2841 if (vd->vdev_ops->vdev_op_leaf) { 2842 switch (zio->io_type) { 2843 case ZIO_TYPE_READ: 2844 if (vdev_cache_read(zio)) 2845 return (ZIO_PIPELINE_CONTINUE); 2846 /* FALLTHROUGH */ 2847 case ZIO_TYPE_WRITE: 2848 case ZIO_TYPE_FREE: 2849 if ((zio = vdev_queue_io(zio)) == NULL) 2850 return (ZIO_PIPELINE_STOP); 2851 2852 if (!vdev_accessible(vd, zio)) { 2853 zio->io_error = SET_ERROR(ENXIO); 2854 zio_interrupt(zio); 2855 return (ZIO_PIPELINE_STOP); 2856 } 2857 break; 2858 } 2859 /* 2860 * Note that we ignore repair writes for TRIM because they can 2861 * conflict with normal writes. This isn't an issue because, by 2862 * definition, we only repair blocks that aren't freed. 2863 */ 2864 if (zio->io_type == ZIO_TYPE_WRITE && 2865 !(zio->io_flags & ZIO_FLAG_IO_REPAIR) && 2866 !trim_map_write_start(zio)) 2867 return (ZIO_PIPELINE_STOP); 2868 } 2869 2870 vd->vdev_ops->vdev_op_io_start(zio); 2871 return (ZIO_PIPELINE_STOP); 2872} 2873 2874static int 2875zio_vdev_io_done(zio_t *zio) 2876{ 2877 vdev_t *vd = zio->io_vd; 2878 vdev_ops_t *ops = vd ? vd->vdev_ops : &vdev_mirror_ops; 2879 boolean_t unexpected_error = B_FALSE; 2880 2881 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 2882 return (ZIO_PIPELINE_STOP); 2883 2884 ASSERT(zio->io_type == ZIO_TYPE_READ || 2885 zio->io_type == ZIO_TYPE_WRITE || zio->io_type == ZIO_TYPE_FREE); 2886 2887 if (vd != NULL && vd->vdev_ops->vdev_op_leaf && 2888 (zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE || 2889 zio->io_type == ZIO_TYPE_FREE)) { 2890 2891 if (zio->io_type == ZIO_TYPE_WRITE && 2892 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) 2893 trim_map_write_done(zio); 2894 2895 vdev_queue_io_done(zio); 2896 2897 if (zio->io_type == ZIO_TYPE_WRITE) 2898 vdev_cache_write(zio); 2899 2900 if (zio_injection_enabled && zio->io_error == 0) 2901 zio->io_error = zio_handle_device_injection(vd, 2902 zio, EIO); 2903 2904 if (zio_injection_enabled && zio->io_error == 0) 2905 zio->io_error = zio_handle_label_injection(zio, EIO); 2906 2907 if (zio->io_error) { 2908 if (zio->io_error == ENOTSUP && 2909 zio->io_type == ZIO_TYPE_FREE) { 2910 /* Not all devices support TRIM. */ 2911 } else if (!vdev_accessible(vd, zio)) { 2912 zio->io_error = SET_ERROR(ENXIO); 2913 } else { 2914 unexpected_error = B_TRUE; 2915 } 2916 } 2917 } 2918 2919 ops->vdev_op_io_done(zio); 2920 2921 if (unexpected_error) 2922 VERIFY(vdev_probe(vd, zio) == NULL); 2923 2924 return (ZIO_PIPELINE_CONTINUE); 2925} 2926 2927/* 2928 * For non-raidz ZIOs, we can just copy aside the bad data read from the 2929 * disk, and use that to finish the checksum ereport later. 2930 */ 2931static void 2932zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr, 2933 const void *good_buf) 2934{ 2935 /* no processing needed */ 2936 zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE); 2937} 2938 2939/*ARGSUSED*/ 2940void 2941zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *ignored) 2942{ 2943 void *buf = zio_buf_alloc(zio->io_size); 2944 2945 bcopy(zio->io_data, buf, zio->io_size); 2946 2947 zcr->zcr_cbinfo = zio->io_size; 2948 zcr->zcr_cbdata = buf; 2949 zcr->zcr_finish = zio_vsd_default_cksum_finish; 2950 zcr->zcr_free = zio_buf_free; 2951} 2952 2953static int 2954zio_vdev_io_assess(zio_t *zio) 2955{ 2956 vdev_t *vd = zio->io_vd; 2957 2958 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 2959 return (ZIO_PIPELINE_STOP); 2960 2961 if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 2962 spa_config_exit(zio->io_spa, SCL_ZIO, zio); 2963 2964 if (zio->io_vsd != NULL) { 2965 zio->io_vsd_ops->vsd_free(zio); 2966 zio->io_vsd = NULL; 2967 } 2968 2969 if (zio_injection_enabled && zio->io_error == 0) 2970 zio->io_error = zio_handle_fault_injection(zio, EIO); 2971 2972 if (zio->io_type == ZIO_TYPE_FREE && 2973 zio->io_priority != ZIO_PRIORITY_NOW) { 2974 switch (zio->io_error) { 2975 case 0: 2976 ZIO_TRIM_STAT_INCR(bytes, zio->io_size); 2977 ZIO_TRIM_STAT_BUMP(success); 2978 break; 2979 case EOPNOTSUPP: 2980 ZIO_TRIM_STAT_BUMP(unsupported); 2981 break; 2982 default: 2983 ZIO_TRIM_STAT_BUMP(failed); 2984 break; 2985 } 2986 } 2987 2988 /* 2989 * If the I/O failed, determine whether we should attempt to retry it. 2990 * 2991 * On retry, we cut in line in the issue queue, since we don't want 2992 * compression/checksumming/etc. work to prevent our (cheap) IO reissue. 2993 */ 2994 if (zio->io_error && vd == NULL && 2995 !(zio->io_flags & (ZIO_FLAG_DONT_RETRY | ZIO_FLAG_IO_RETRY))) { 2996 ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_QUEUE)); /* not a leaf */ 2997 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_BYPASS)); /* not a leaf */ 2998 zio->io_error = 0; 2999 zio->io_flags |= ZIO_FLAG_IO_RETRY | 3000 ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE; 3001 zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1; 3002 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, 3003 zio_requeue_io_start_cut_in_line); 3004 return (ZIO_PIPELINE_STOP); 3005 } 3006 3007 /* 3008 * If we got an error on a leaf device, convert it to ENXIO 3009 * if the device is not accessible at all. 3010 */ 3011 if (zio->io_error && vd != NULL && vd->vdev_ops->vdev_op_leaf && 3012 !vdev_accessible(vd, zio)) 3013 zio->io_error = SET_ERROR(ENXIO); 3014 3015 /* 3016 * If we can't write to an interior vdev (mirror or RAID-Z), 3017 * set vdev_cant_write so that we stop trying to allocate from it. 3018 */ 3019 if (zio->io_error == ENXIO && zio->io_type == ZIO_TYPE_WRITE && 3020 vd != NULL && !vd->vdev_ops->vdev_op_leaf) { 3021 vd->vdev_cant_write = B_TRUE; 3022 } 3023 3024 if (zio->io_error) 3025 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 3026 3027 if (vd != NULL && vd->vdev_ops->vdev_op_leaf && 3028 zio->io_physdone != NULL) { 3029 ASSERT(!(zio->io_flags & ZIO_FLAG_DELEGATED)); 3030 ASSERT(zio->io_child_type == ZIO_CHILD_VDEV); 3031 zio->io_physdone(zio->io_logical); 3032 } 3033 3034 return (ZIO_PIPELINE_CONTINUE); 3035} 3036 3037void 3038zio_vdev_io_reissue(zio_t *zio) 3039{ 3040 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 3041 ASSERT(zio->io_error == 0); 3042 3043 zio->io_stage >>= 1; 3044} 3045 3046void 3047zio_vdev_io_redone(zio_t *zio) 3048{ 3049 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE); 3050 3051 zio->io_stage >>= 1; 3052} 3053 3054void 3055zio_vdev_io_bypass(zio_t *zio) 3056{ 3057 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 3058 ASSERT(zio->io_error == 0); 3059 3060 zio->io_flags |= ZIO_FLAG_IO_BYPASS; 3061 zio->io_stage = ZIO_STAGE_VDEV_IO_ASSESS >> 1; 3062} 3063 3064/* 3065 * ========================================================================== 3066 * Generate and verify checksums 3067 * ========================================================================== 3068 */ 3069static int 3070zio_checksum_generate(zio_t *zio) 3071{ 3072 blkptr_t *bp = zio->io_bp; 3073 enum zio_checksum checksum; 3074 3075 if (bp == NULL) { 3076 /* 3077 * This is zio_write_phys(). 3078 * We're either generating a label checksum, or none at all. 3079 */ 3080 checksum = zio->io_prop.zp_checksum; 3081 3082 if (checksum == ZIO_CHECKSUM_OFF) 3083 return (ZIO_PIPELINE_CONTINUE); 3084 3085 ASSERT(checksum == ZIO_CHECKSUM_LABEL); 3086 } else { 3087 if (BP_IS_GANG(bp) && zio->io_child_type == ZIO_CHILD_GANG) { 3088 ASSERT(!IO_IS_ALLOCATING(zio)); 3089 checksum = ZIO_CHECKSUM_GANG_HEADER; 3090 } else { 3091 checksum = BP_GET_CHECKSUM(bp); 3092 } 3093 } 3094 3095 zio_checksum_compute(zio, checksum, zio->io_data, zio->io_size); 3096 3097 return (ZIO_PIPELINE_CONTINUE); 3098} 3099 3100static int 3101zio_checksum_verify(zio_t *zio) 3102{ 3103 zio_bad_cksum_t info; 3104 blkptr_t *bp = zio->io_bp; 3105 int error; 3106 3107 ASSERT(zio->io_vd != NULL); 3108 3109 if (bp == NULL) { 3110 /* 3111 * This is zio_read_phys(). 3112 * We're either verifying a label checksum, or nothing at all. 3113 */ 3114 if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF) 3115 return (ZIO_PIPELINE_CONTINUE); 3116 3117 ASSERT(zio->io_prop.zp_checksum == ZIO_CHECKSUM_LABEL); 3118 } 3119 3120 if ((error = zio_checksum_error(zio, &info)) != 0) { 3121 zio->io_error = error; 3122 if (error == ECKSUM && 3123 !(zio->io_flags & ZIO_FLAG_SPECULATIVE)) { 3124 zfs_ereport_start_checksum(zio->io_spa, 3125 zio->io_vd, zio, zio->io_offset, 3126 zio->io_size, NULL, &info); 3127 } 3128 } 3129 3130 return (ZIO_PIPELINE_CONTINUE); 3131} 3132 3133/* 3134 * Called by RAID-Z to ensure we don't compute the checksum twice. 3135 */ 3136void 3137zio_checksum_verified(zio_t *zio) 3138{ 3139 zio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 3140} 3141 3142/* 3143 * ========================================================================== 3144 * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other. 3145 * An error of 0 indicates success. ENXIO indicates whole-device failure, 3146 * which may be transient (e.g. unplugged) or permament. ECKSUM and EIO 3147 * indicate errors that are specific to one I/O, and most likely permanent. 3148 * Any other error is presumed to be worse because we weren't expecting it. 3149 * ========================================================================== 3150 */ 3151int 3152zio_worst_error(int e1, int e2) 3153{ 3154 static int zio_error_rank[] = { 0, ENXIO, ECKSUM, EIO }; 3155 int r1, r2; 3156 3157 for (r1 = 0; r1 < sizeof (zio_error_rank) / sizeof (int); r1++) 3158 if (e1 == zio_error_rank[r1]) 3159 break; 3160 3161 for (r2 = 0; r2 < sizeof (zio_error_rank) / sizeof (int); r2++) 3162 if (e2 == zio_error_rank[r2]) 3163 break; 3164 3165 return (r1 > r2 ? e1 : e2); 3166} 3167 3168/* 3169 * ========================================================================== 3170 * I/O completion 3171 * ========================================================================== 3172 */ 3173static int 3174zio_ready(zio_t *zio) 3175{ 3176 blkptr_t *bp = zio->io_bp; 3177 zio_t *pio, *pio_next; 3178 3179 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 3180 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_READY)) 3181 return (ZIO_PIPELINE_STOP); 3182 3183 if (zio->io_ready) { 3184 ASSERT(IO_IS_ALLOCATING(zio)); 3185 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp) || 3186 (zio->io_flags & ZIO_FLAG_NOPWRITE)); 3187 ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0); 3188 3189 zio->io_ready(zio); 3190 } 3191 3192 if (bp != NULL && bp != &zio->io_bp_copy) 3193 zio->io_bp_copy = *bp; 3194 3195 if (zio->io_error) 3196 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 3197 3198 mutex_enter(&zio->io_lock); 3199 zio->io_state[ZIO_WAIT_READY] = 1; 3200 pio = zio_walk_parents(zio); 3201 mutex_exit(&zio->io_lock); 3202 3203 /* 3204 * As we notify zio's parents, new parents could be added. 3205 * New parents go to the head of zio's io_parent_list, however, 3206 * so we will (correctly) not notify them. The remainder of zio's 3207 * io_parent_list, from 'pio_next' onward, cannot change because 3208 * all parents must wait for us to be done before they can be done. 3209 */ 3210 for (; pio != NULL; pio = pio_next) { 3211 pio_next = zio_walk_parents(zio); 3212 zio_notify_parent(pio, zio, ZIO_WAIT_READY); 3213 } 3214 3215 if (zio->io_flags & ZIO_FLAG_NODATA) { 3216 if (BP_IS_GANG(bp)) { 3217 zio->io_flags &= ~ZIO_FLAG_NODATA; 3218 } else { 3219 ASSERT((uintptr_t)zio->io_data < SPA_MAXBLOCKSIZE); 3220 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 3221 } 3222 } 3223 3224 if (zio_injection_enabled && 3225 zio->io_spa->spa_syncing_txg == zio->io_txg) 3226 zio_handle_ignored_writes(zio); 3227 3228 return (ZIO_PIPELINE_CONTINUE); 3229} 3230 3231static int 3232zio_done(zio_t *zio) 3233{ 3234 spa_t *spa = zio->io_spa; 3235 zio_t *lio = zio->io_logical; 3236 blkptr_t *bp = zio->io_bp; 3237 vdev_t *vd = zio->io_vd; 3238 uint64_t psize = zio->io_size; 3239 zio_t *pio, *pio_next; 3240 3241 /* 3242 * If our children haven't all completed, 3243 * wait for them and then repeat this pipeline stage. 3244 */ 3245 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE) || 3246 zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE) || 3247 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE) || 3248 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_DONE)) 3249 return (ZIO_PIPELINE_STOP); 3250 3251 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 3252 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 3253 ASSERT(zio->io_children[c][w] == 0); 3254 3255 if (bp != NULL && !BP_IS_EMBEDDED(bp)) { 3256 ASSERT(bp->blk_pad[0] == 0); 3257 ASSERT(bp->blk_pad[1] == 0); 3258 ASSERT(bcmp(bp, &zio->io_bp_copy, sizeof (blkptr_t)) == 0 || 3259 (bp == zio_unique_parent(zio)->io_bp)); 3260 if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(bp) && 3261 zio->io_bp_override == NULL && 3262 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) { 3263 ASSERT(!BP_SHOULD_BYTESWAP(bp)); 3264 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(bp)); 3265 ASSERT(BP_COUNT_GANG(bp) == 0 || 3266 (BP_COUNT_GANG(bp) == BP_GET_NDVAS(bp))); 3267 } 3268 if (zio->io_flags & ZIO_FLAG_NOPWRITE) 3269 VERIFY(BP_EQUAL(bp, &zio->io_bp_orig)); 3270 } 3271 3272 /* 3273 * If there were child vdev/gang/ddt errors, they apply to us now. 3274 */ 3275 zio_inherit_child_errors(zio, ZIO_CHILD_VDEV); 3276 zio_inherit_child_errors(zio, ZIO_CHILD_GANG); 3277 zio_inherit_child_errors(zio, ZIO_CHILD_DDT); 3278 3279 /* 3280 * If the I/O on the transformed data was successful, generate any 3281 * checksum reports now while we still have the transformed data. 3282 */ 3283 if (zio->io_error == 0) { 3284 while (zio->io_cksum_report != NULL) { 3285 zio_cksum_report_t *zcr = zio->io_cksum_report; 3286 uint64_t align = zcr->zcr_align; 3287 uint64_t asize = P2ROUNDUP(psize, align); 3288 char *abuf = zio->io_data; 3289 3290 if (asize != psize) { 3291 abuf = zio_buf_alloc(asize); 3292 bcopy(zio->io_data, abuf, psize); 3293 bzero(abuf + psize, asize - psize); 3294 } 3295 3296 zio->io_cksum_report = zcr->zcr_next; 3297 zcr->zcr_next = NULL; 3298 zcr->zcr_finish(zcr, abuf); 3299 zfs_ereport_free_checksum(zcr); 3300 3301 if (asize != psize) 3302 zio_buf_free(abuf, asize); 3303 } 3304 } 3305 3306 zio_pop_transforms(zio); /* note: may set zio->io_error */ 3307 3308 vdev_stat_update(zio, psize); 3309 3310 if (zio->io_error) { 3311 /* 3312 * If this I/O is attached to a particular vdev, 3313 * generate an error message describing the I/O failure 3314 * at the block level. We ignore these errors if the 3315 * device is currently unavailable. 3316 */ 3317 if (zio->io_error != ECKSUM && vd != NULL && !vdev_is_dead(vd)) 3318 zfs_ereport_post(FM_EREPORT_ZFS_IO, spa, vd, zio, 0, 0); 3319 3320 if ((zio->io_error == EIO || !(zio->io_flags & 3321 (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) && 3322 zio == lio) { 3323 /* 3324 * For logical I/O requests, tell the SPA to log the 3325 * error and generate a logical data ereport. 3326 */ 3327 spa_log_error(spa, zio); 3328 zfs_ereport_post(FM_EREPORT_ZFS_DATA, spa, NULL, zio, 3329 0, 0); 3330 } 3331 } 3332 3333 if (zio->io_error && zio == lio) { 3334 /* 3335 * Determine whether zio should be reexecuted. This will 3336 * propagate all the way to the root via zio_notify_parent(). 3337 */ 3338 ASSERT(vd == NULL && bp != NULL); 3339 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3340 3341 if (IO_IS_ALLOCATING(zio) && 3342 !(zio->io_flags & ZIO_FLAG_CANFAIL)) { 3343 if (zio->io_error != ENOSPC) 3344 zio->io_reexecute |= ZIO_REEXECUTE_NOW; 3345 else 3346 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3347 } 3348 3349 if ((zio->io_type == ZIO_TYPE_READ || 3350 zio->io_type == ZIO_TYPE_FREE) && 3351 !(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && 3352 zio->io_error == ENXIO && 3353 spa_load_state(spa) == SPA_LOAD_NONE && 3354 spa_get_failmode(spa) != ZIO_FAILURE_MODE_CONTINUE) 3355 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3356 3357 if (!(zio->io_flags & ZIO_FLAG_CANFAIL) && !zio->io_reexecute) 3358 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3359 3360 /* 3361 * Here is a possibly good place to attempt to do 3362 * either combinatorial reconstruction or error correction 3363 * based on checksums. It also might be a good place 3364 * to send out preliminary ereports before we suspend 3365 * processing. 3366 */ 3367 } 3368 3369 /* 3370 * If there were logical child errors, they apply to us now. 3371 * We defer this until now to avoid conflating logical child 3372 * errors with errors that happened to the zio itself when 3373 * updating vdev stats and reporting FMA events above. 3374 */ 3375 zio_inherit_child_errors(zio, ZIO_CHILD_LOGICAL); 3376 3377 if ((zio->io_error || zio->io_reexecute) && 3378 IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio && 3379 !(zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE))) 3380 zio_dva_unallocate(zio, zio->io_gang_tree, bp); 3381 3382 zio_gang_tree_free(&zio->io_gang_tree); 3383 3384 /* 3385 * Godfather I/Os should never suspend. 3386 */ 3387 if ((zio->io_flags & ZIO_FLAG_GODFATHER) && 3388 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) 3389 zio->io_reexecute = 0; 3390 3391 if (zio->io_reexecute) { 3392 /* 3393 * This is a logical I/O that wants to reexecute. 3394 * 3395 * Reexecute is top-down. When an i/o fails, if it's not 3396 * the root, it simply notifies its parent and sticks around. 3397 * The parent, seeing that it still has children in zio_done(), 3398 * does the same. This percolates all the way up to the root. 3399 * The root i/o will reexecute or suspend the entire tree. 3400 * 3401 * This approach ensures that zio_reexecute() honors 3402 * all the original i/o dependency relationships, e.g. 3403 * parents not executing until children are ready. 3404 */ 3405 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3406 3407 zio->io_gang_leader = NULL; 3408 3409 mutex_enter(&zio->io_lock); 3410 zio->io_state[ZIO_WAIT_DONE] = 1; 3411 mutex_exit(&zio->io_lock); 3412 3413 /* 3414 * "The Godfather" I/O monitors its children but is 3415 * not a true parent to them. It will track them through 3416 * the pipeline but severs its ties whenever they get into 3417 * trouble (e.g. suspended). This allows "The Godfather" 3418 * I/O to return status without blocking. 3419 */ 3420 for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) { 3421 zio_link_t *zl = zio->io_walk_link; 3422 pio_next = zio_walk_parents(zio); 3423 3424 if ((pio->io_flags & ZIO_FLAG_GODFATHER) && 3425 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) { 3426 zio_remove_child(pio, zio, zl); 3427 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3428 } 3429 } 3430 3431 if ((pio = zio_unique_parent(zio)) != NULL) { 3432 /* 3433 * We're not a root i/o, so there's nothing to do 3434 * but notify our parent. Don't propagate errors 3435 * upward since we haven't permanently failed yet. 3436 */ 3437 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 3438 zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE; 3439 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3440 } else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) { 3441 /* 3442 * We'd fail again if we reexecuted now, so suspend 3443 * until conditions improve (e.g. device comes online). 3444 */ 3445 zio_suspend(spa, zio); 3446 } else { 3447 /* 3448 * Reexecution is potentially a huge amount of work. 3449 * Hand it off to the otherwise-unused claim taskq. 3450 */ 3451#if defined(illumos) || !defined(_KERNEL) 3452 ASSERT(zio->io_tqent.tqent_next == NULL); 3453#else 3454 ASSERT(zio->io_tqent.tqent_task.ta_pending == 0); 3455#endif 3456 spa_taskq_dispatch_ent(spa, ZIO_TYPE_CLAIM, 3457 ZIO_TASKQ_ISSUE, (task_func_t *)zio_reexecute, zio, 3458 0, &zio->io_tqent); 3459 } 3460 return (ZIO_PIPELINE_STOP); 3461 } 3462 3463 ASSERT(zio->io_child_count == 0); 3464 ASSERT(zio->io_reexecute == 0); 3465 ASSERT(zio->io_error == 0 || (zio->io_flags & ZIO_FLAG_CANFAIL)); 3466 3467 /* 3468 * Report any checksum errors, since the I/O is complete. 3469 */ 3470 while (zio->io_cksum_report != NULL) { 3471 zio_cksum_report_t *zcr = zio->io_cksum_report; 3472 zio->io_cksum_report = zcr->zcr_next; 3473 zcr->zcr_next = NULL; 3474 zcr->zcr_finish(zcr, NULL); 3475 zfs_ereport_free_checksum(zcr); 3476 } 3477 3478 /* 3479 * It is the responsibility of the done callback to ensure that this 3480 * particular zio is no longer discoverable for adoption, and as 3481 * such, cannot acquire any new parents. 3482 */ 3483 if (zio->io_done) 3484 zio->io_done(zio); 3485 3486 mutex_enter(&zio->io_lock); 3487 zio->io_state[ZIO_WAIT_DONE] = 1; 3488 mutex_exit(&zio->io_lock); 3489 3490 for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) { 3491 zio_link_t *zl = zio->io_walk_link; 3492 pio_next = zio_walk_parents(zio); 3493 zio_remove_child(pio, zio, zl); 3494 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3495 } 3496 3497 if (zio->io_waiter != NULL) { 3498 mutex_enter(&zio->io_lock); 3499 zio->io_executor = NULL; 3500 cv_broadcast(&zio->io_cv); 3501 mutex_exit(&zio->io_lock); 3502 } else { 3503 zio_destroy(zio); 3504 } 3505 3506 return (ZIO_PIPELINE_STOP); 3507} 3508 3509/* 3510 * ========================================================================== 3511 * I/O pipeline definition 3512 * ========================================================================== 3513 */ 3514static zio_pipe_stage_t *zio_pipeline[] = { 3515 NULL, 3516 zio_read_bp_init, 3517 zio_free_bp_init, 3518 zio_issue_async, 3519 zio_write_bp_init, 3520 zio_checksum_generate, 3521 zio_nop_write, 3522 zio_ddt_read_start, 3523 zio_ddt_read_done, 3524 zio_ddt_write, 3525 zio_ddt_free, 3526 zio_gang_assemble, 3527 zio_gang_issue, 3528 zio_dva_allocate, 3529 zio_dva_free, 3530 zio_dva_claim, 3531 zio_ready, 3532 zio_vdev_io_start, 3533 zio_vdev_io_done, 3534 zio_vdev_io_assess, 3535 zio_checksum_verify, 3536 zio_done 3537}; 3538 3539 3540 3541 3542/* 3543 * Compare two zbookmark_phys_t's to see which we would reach first in a 3544 * pre-order traversal of the object tree. 3545 * 3546 * This is simple in every case aside from the meta-dnode object. For all other 3547 * objects, we traverse them in order (object 1 before object 2, and so on). 3548 * However, all of these objects are traversed while traversing object 0, since 3549 * the data it points to is the list of objects. Thus, we need to convert to a 3550 * canonical representation so we can compare meta-dnode bookmarks to 3551 * non-meta-dnode bookmarks. 3552 * 3553 * We do this by calculating "equivalents" for each field of the zbookmark. 3554 * zbookmarks outside of the meta-dnode use their own object and level, and 3555 * calculate the level 0 equivalent (the first L0 blkid that is contained in the 3556 * blocks this bookmark refers to) by multiplying their blkid by their span 3557 * (the number of L0 blocks contained within one block at their level). 3558 * zbookmarks inside the meta-dnode calculate their object equivalent 3559 * (which is L0equiv * dnodes per data block), use 0 for their L0equiv, and use 3560 * level + 1<<31 (any value larger than a level could ever be) for their level. 3561 * This causes them to always compare before a bookmark in their object 3562 * equivalent, compare appropriately to bookmarks in other objects, and to 3563 * compare appropriately to other bookmarks in the meta-dnode. 3564 */ 3565int 3566zbookmark_compare(uint16_t dbss1, uint8_t ibs1, uint16_t dbss2, uint8_t ibs2, 3567 const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2) 3568{ 3569 /* 3570 * These variables represent the "equivalent" values for the zbookmark, 3571 * after converting zbookmarks inside the meta dnode to their 3572 * normal-object equivalents. 3573 */ 3574 uint64_t zb1obj, zb2obj; 3575 uint64_t zb1L0, zb2L0; 3576 uint64_t zb1level, zb2level; 3577 3578 if (zb1->zb_object == zb2->zb_object && 3579 zb1->zb_level == zb2->zb_level && 3580 zb1->zb_blkid == zb2->zb_blkid) 3581 return (0); 3582 3583 /* 3584 * BP_SPANB calculates the span in blocks. 3585 */ 3586 zb1L0 = (zb1->zb_blkid) * BP_SPANB(ibs1, zb1->zb_level); 3587 zb2L0 = (zb2->zb_blkid) * BP_SPANB(ibs2, zb2->zb_level); 3588 3589 if (zb1->zb_object == DMU_META_DNODE_OBJECT) { 3590 zb1obj = zb1L0 * (dbss1 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT)); 3591 zb1L0 = 0; 3592 zb1level = zb1->zb_level + COMPARE_META_LEVEL; 3593 } else { 3594 zb1obj = zb1->zb_object; 3595 zb1level = zb1->zb_level; 3596 } 3597 3598 if (zb2->zb_object == DMU_META_DNODE_OBJECT) { 3599 zb2obj = zb2L0 * (dbss2 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT)); 3600 zb2L0 = 0; 3601 zb2level = zb2->zb_level + COMPARE_META_LEVEL; 3602 } else { 3603 zb2obj = zb2->zb_object; 3604 zb2level = zb2->zb_level; 3605 } 3606 3607 /* Now that we have a canonical representation, do the comparison. */ 3608 if (zb1obj != zb2obj) 3609 return (zb1obj < zb2obj ? -1 : 1); 3610 else if (zb1L0 != zb2L0) 3611 return (zb1L0 < zb2L0 ? -1 : 1); 3612 else if (zb1level != zb2level) 3613 return (zb1level > zb2level ? -1 : 1); 3614 /* 3615 * This can (theoretically) happen if the bookmarks have the same object 3616 * and level, but different blkids, if the block sizes are not the same. 3617 * There is presently no way to change the indirect block sizes 3618 */ 3619 return (0); 3620} 3621 3622/* 3623 * This function checks the following: given that last_block is the place that 3624 * our traversal stopped last time, does that guarantee that we've visited 3625 * every node under subtree_root? Therefore, we can't just use the raw output 3626 * of zbookmark_compare. We have to pass in a modified version of 3627 * subtree_root; by incrementing the block id, and then checking whether 3628 * last_block is before or equal to that, we can tell whether or not having 3629 * visited last_block implies that all of subtree_root's children have been 3630 * visited. 3631 */ 3632boolean_t 3633zbookmark_subtree_completed(const dnode_phys_t *dnp, 3634 const zbookmark_phys_t *subtree_root, const zbookmark_phys_t *last_block) 3635{ 3636 zbookmark_phys_t mod_zb = *subtree_root; 3637 mod_zb.zb_blkid++; 3638 ASSERT(last_block->zb_level == 0); 3639 3640 /* The objset_phys_t isn't before anything. */ 3641 if (dnp == NULL) 3642 return (B_FALSE); 3643 3644 /* 3645 * We pass in 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT) for the 3646 * data block size in sectors, because that variable is only used if 3647 * the bookmark refers to a block in the meta-dnode. Since we don't 3648 * know without examining it what object it refers to, and there's no 3649 * harm in passing in this value in other cases, we always pass it in. 3650 * 3651 * We pass in 0 for the indirect block size shift because zb2 must be 3652 * level 0. The indirect block size is only used to calculate the span 3653 * of the bookmark, but since the bookmark must be level 0, the span is 3654 * always 1, so the math works out. 3655 * 3656 * If you make changes to how the zbookmark_compare code works, be sure 3657 * to make sure that this code still works afterwards. 3658 */ 3659 return (zbookmark_compare(dnp->dn_datablkszsec, dnp->dn_indblkshift, 3660 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT), 0, &mod_zb, 3661 last_block) <= 0); 3662} 3663