zio.c revision 288571
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 BP_SPANB(indblkshift, level) \ 97 (((uint64_t)1) << ((level) * ((indblkshift) - SPA_BLKPTRSHIFT))) 98#define COMPARE_META_LEVEL 0x80000000ul 99/* 100 * The following actions directly effect the spa's sync-to-convergence logic. 101 * The values below define the sync pass when we start performing the action. 102 * Care should be taken when changing these values as they directly impact 103 * spa_sync() performance. Tuning these values may introduce subtle performance 104 * pathologies and should only be done in the context of performance analysis. 105 * These tunables will eventually be removed and replaced with #defines once 106 * enough analysis has been done to determine optimal values. 107 * 108 * The 'zfs_sync_pass_deferred_free' pass must be greater than 1 to ensure that 109 * regular blocks are not deferred. 110 */ 111int zfs_sync_pass_deferred_free = 2; /* defer frees starting in this pass */ 112TUNABLE_INT("vfs.zfs.sync_pass_deferred_free", &zfs_sync_pass_deferred_free); 113SYSCTL_INT(_vfs_zfs, OID_AUTO, sync_pass_deferred_free, CTLFLAG_RDTUN, 114 &zfs_sync_pass_deferred_free, 0, "defer frees starting in this pass"); 115int zfs_sync_pass_dont_compress = 5; /* don't compress starting in this pass */ 116TUNABLE_INT("vfs.zfs.sync_pass_dont_compress", &zfs_sync_pass_dont_compress); 117SYSCTL_INT(_vfs_zfs, OID_AUTO, sync_pass_dont_compress, CTLFLAG_RDTUN, 118 &zfs_sync_pass_dont_compress, 0, "don't compress starting in this pass"); 119int zfs_sync_pass_rewrite = 2; /* rewrite new bps starting in this pass */ 120TUNABLE_INT("vfs.zfs.sync_pass_rewrite", &zfs_sync_pass_rewrite); 121SYSCTL_INT(_vfs_zfs, OID_AUTO, sync_pass_rewrite, CTLFLAG_RDTUN, 122 &zfs_sync_pass_rewrite, 0, "rewrite new bps starting in this pass"); 123 124/* 125 * An allocating zio is one that either currently has the DVA allocate 126 * stage set or will have it later in its lifetime. 127 */ 128#define IO_IS_ALLOCATING(zio) ((zio)->io_orig_pipeline & ZIO_STAGE_DVA_ALLOCATE) 129 130boolean_t zio_requeue_io_start_cut_in_line = B_TRUE; 131 132#ifdef ZFS_DEBUG 133int zio_buf_debug_limit = 16384; 134#else 135int zio_buf_debug_limit = 0; 136#endif 137 138void 139zio_init(void) 140{ 141 size_t c; 142 zio_cache = kmem_cache_create("zio_cache", 143 sizeof (zio_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 144 zio_link_cache = kmem_cache_create("zio_link_cache", 145 sizeof (zio_link_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 146 if (!zio_use_uma) 147 goto out; 148 149 /* 150 * For small buffers, we want a cache for each multiple of 151 * SPA_MINBLOCKSIZE. For larger buffers, we want a cache 152 * for each quarter-power of 2. 153 */ 154 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { 155 size_t size = (c + 1) << SPA_MINBLOCKSHIFT; 156 size_t p2 = size; 157 size_t align = 0; 158 size_t cflags = (size > zio_buf_debug_limit) ? KMC_NODEBUG : 0; 159 160 while (!ISP2(p2)) 161 p2 &= p2 - 1; 162 163#ifdef illumos 164#ifndef _KERNEL 165 /* 166 * If we are using watchpoints, put each buffer on its own page, 167 * to eliminate the performance overhead of trapping to the 168 * kernel when modifying a non-watched buffer that shares the 169 * page with a watched buffer. 170 */ 171 if (arc_watch && !IS_P2ALIGNED(size, PAGESIZE)) 172 continue; 173#endif 174#endif /* illumos */ 175 if (size <= 4 * SPA_MINBLOCKSIZE) { 176 align = SPA_MINBLOCKSIZE; 177 } else if (IS_P2ALIGNED(size, p2 >> 2)) { 178 align = MIN(p2 >> 2, PAGESIZE); 179 } 180 181 if (align != 0) { 182 char name[36]; 183 (void) sprintf(name, "zio_buf_%lu", (ulong_t)size); 184 zio_buf_cache[c] = kmem_cache_create(name, size, 185 align, NULL, NULL, NULL, NULL, NULL, cflags); 186 187 /* 188 * Since zio_data bufs do not appear in crash dumps, we 189 * pass KMC_NOTOUCH so that no allocator metadata is 190 * stored with the buffers. 191 */ 192 (void) sprintf(name, "zio_data_buf_%lu", (ulong_t)size); 193 zio_data_buf_cache[c] = kmem_cache_create(name, size, 194 align, NULL, NULL, NULL, NULL, NULL, 195 cflags | KMC_NOTOUCH | KMC_NODEBUG); 196 } 197 } 198 199 while (--c != 0) { 200 ASSERT(zio_buf_cache[c] != NULL); 201 if (zio_buf_cache[c - 1] == NULL) 202 zio_buf_cache[c - 1] = zio_buf_cache[c]; 203 204 ASSERT(zio_data_buf_cache[c] != NULL); 205 if (zio_data_buf_cache[c - 1] == NULL) 206 zio_data_buf_cache[c - 1] = zio_data_buf_cache[c]; 207 } 208out: 209 210 zio_inject_init(); 211 212 zio_trim_ksp = kstat_create("zfs", 0, "zio_trim", "misc", 213 KSTAT_TYPE_NAMED, 214 sizeof(zio_trim_stats) / sizeof(kstat_named_t), 215 KSTAT_FLAG_VIRTUAL); 216 217 if (zio_trim_ksp != NULL) { 218 zio_trim_ksp->ks_data = &zio_trim_stats; 219 kstat_install(zio_trim_ksp); 220 } 221} 222 223void 224zio_fini(void) 225{ 226 size_t c; 227 kmem_cache_t *last_cache = NULL; 228 kmem_cache_t *last_data_cache = NULL; 229 230 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { 231 if (zio_buf_cache[c] != last_cache) { 232 last_cache = zio_buf_cache[c]; 233 kmem_cache_destroy(zio_buf_cache[c]); 234 } 235 zio_buf_cache[c] = NULL; 236 237 if (zio_data_buf_cache[c] != last_data_cache) { 238 last_data_cache = zio_data_buf_cache[c]; 239 kmem_cache_destroy(zio_data_buf_cache[c]); 240 } 241 zio_data_buf_cache[c] = NULL; 242 } 243 244 kmem_cache_destroy(zio_link_cache); 245 kmem_cache_destroy(zio_cache); 246 247 zio_inject_fini(); 248 249 if (zio_trim_ksp != NULL) { 250 kstat_delete(zio_trim_ksp); 251 zio_trim_ksp = NULL; 252 } 253} 254 255/* 256 * ========================================================================== 257 * Allocate and free I/O buffers 258 * ========================================================================== 259 */ 260 261/* 262 * Use zio_buf_alloc to allocate ZFS metadata. This data will appear in a 263 * crashdump if the kernel panics, so use it judiciously. Obviously, it's 264 * useful to inspect ZFS metadata, but if possible, we should avoid keeping 265 * excess / transient data in-core during a crashdump. 266 */ 267void * 268zio_buf_alloc(size_t size) 269{ 270 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 271 int flags = zio_exclude_metadata ? KM_NODEBUG : 0; 272 273 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 274 275 if (zio_use_uma) 276 return (kmem_cache_alloc(zio_buf_cache[c], KM_PUSHPAGE)); 277 else 278 return (kmem_alloc(size, KM_SLEEP|flags)); 279} 280 281/* 282 * Use zio_data_buf_alloc to allocate data. The data will not appear in a 283 * crashdump if the kernel panics. This exists so that we will limit the amount 284 * of ZFS data that shows up in a kernel crashdump. (Thus reducing the amount 285 * of kernel heap dumped to disk when the kernel panics) 286 */ 287void * 288zio_data_buf_alloc(size_t size) 289{ 290 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 291 292 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 293 294 if (zio_use_uma) 295 return (kmem_cache_alloc(zio_data_buf_cache[c], KM_PUSHPAGE)); 296 else 297 return (kmem_alloc(size, KM_SLEEP | KM_NODEBUG)); 298} 299 300void 301zio_buf_free(void *buf, size_t size) 302{ 303 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 304 305 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 306 307 if (zio_use_uma) 308 kmem_cache_free(zio_buf_cache[c], buf); 309 else 310 kmem_free(buf, size); 311} 312 313void 314zio_data_buf_free(void *buf, size_t size) 315{ 316 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 317 318 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 319 320 if (zio_use_uma) 321 kmem_cache_free(zio_data_buf_cache[c], buf); 322 else 323 kmem_free(buf, size); 324} 325 326/* 327 * ========================================================================== 328 * Push and pop I/O transform buffers 329 * ========================================================================== 330 */ 331static void 332zio_push_transform(zio_t *zio, void *data, uint64_t size, uint64_t bufsize, 333 zio_transform_func_t *transform) 334{ 335 zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP); 336 337 zt->zt_orig_data = zio->io_data; 338 zt->zt_orig_size = zio->io_size; 339 zt->zt_bufsize = bufsize; 340 zt->zt_transform = transform; 341 342 zt->zt_next = zio->io_transform_stack; 343 zio->io_transform_stack = zt; 344 345 zio->io_data = data; 346 zio->io_size = size; 347} 348 349static void 350zio_pop_transforms(zio_t *zio) 351{ 352 zio_transform_t *zt; 353 354 while ((zt = zio->io_transform_stack) != NULL) { 355 if (zt->zt_transform != NULL) 356 zt->zt_transform(zio, 357 zt->zt_orig_data, zt->zt_orig_size); 358 359 if (zt->zt_bufsize != 0) 360 zio_buf_free(zio->io_data, zt->zt_bufsize); 361 362 zio->io_data = zt->zt_orig_data; 363 zio->io_size = zt->zt_orig_size; 364 zio->io_transform_stack = zt->zt_next; 365 366 kmem_free(zt, sizeof (zio_transform_t)); 367 } 368} 369 370/* 371 * ========================================================================== 372 * I/O transform callbacks for subblocks and decompression 373 * ========================================================================== 374 */ 375static void 376zio_subblock(zio_t *zio, void *data, uint64_t size) 377{ 378 ASSERT(zio->io_size > size); 379 380 if (zio->io_type == ZIO_TYPE_READ) 381 bcopy(zio->io_data, data, size); 382} 383 384static void 385zio_decompress(zio_t *zio, void *data, uint64_t size) 386{ 387 if (zio->io_error == 0 && 388 zio_decompress_data(BP_GET_COMPRESS(zio->io_bp), 389 zio->io_data, data, zio->io_size, size) != 0) 390 zio->io_error = SET_ERROR(EIO); 391} 392 393/* 394 * ========================================================================== 395 * I/O parent/child relationships and pipeline interlocks 396 * ========================================================================== 397 */ 398/* 399 * NOTE - Callers to zio_walk_parents() and zio_walk_children must 400 * continue calling these functions until they return NULL. 401 * Otherwise, the next caller will pick up the list walk in 402 * some indeterminate state. (Otherwise every caller would 403 * have to pass in a cookie to keep the state represented by 404 * io_walk_link, which gets annoying.) 405 */ 406zio_t * 407zio_walk_parents(zio_t *cio) 408{ 409 zio_link_t *zl = cio->io_walk_link; 410 list_t *pl = &cio->io_parent_list; 411 412 zl = (zl == NULL) ? list_head(pl) : list_next(pl, zl); 413 cio->io_walk_link = zl; 414 415 if (zl == NULL) 416 return (NULL); 417 418 ASSERT(zl->zl_child == cio); 419 return (zl->zl_parent); 420} 421 422zio_t * 423zio_walk_children(zio_t *pio) 424{ 425 zio_link_t *zl = pio->io_walk_link; 426 list_t *cl = &pio->io_child_list; 427 428 zl = (zl == NULL) ? list_head(cl) : list_next(cl, zl); 429 pio->io_walk_link = zl; 430 431 if (zl == NULL) 432 return (NULL); 433 434 ASSERT(zl->zl_parent == pio); 435 return (zl->zl_child); 436} 437 438zio_t * 439zio_unique_parent(zio_t *cio) 440{ 441 zio_t *pio = zio_walk_parents(cio); 442 443 VERIFY(zio_walk_parents(cio) == NULL); 444 return (pio); 445} 446 447void 448zio_add_child(zio_t *pio, zio_t *cio) 449{ 450 zio_link_t *zl = kmem_cache_alloc(zio_link_cache, KM_SLEEP); 451 452 /* 453 * Logical I/Os can have logical, gang, or vdev children. 454 * Gang I/Os can have gang or vdev children. 455 * Vdev I/Os can only have vdev children. 456 * The following ASSERT captures all of these constraints. 457 */ 458 ASSERT(cio->io_child_type <= pio->io_child_type); 459 460 zl->zl_parent = pio; 461 zl->zl_child = cio; 462 463 mutex_enter(&cio->io_lock); 464 mutex_enter(&pio->io_lock); 465 466 ASSERT(pio->io_state[ZIO_WAIT_DONE] == 0); 467 468 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 469 pio->io_children[cio->io_child_type][w] += !cio->io_state[w]; 470 471 list_insert_head(&pio->io_child_list, zl); 472 list_insert_head(&cio->io_parent_list, zl); 473 474 pio->io_child_count++; 475 cio->io_parent_count++; 476 477 mutex_exit(&pio->io_lock); 478 mutex_exit(&cio->io_lock); 479} 480 481static void 482zio_remove_child(zio_t *pio, zio_t *cio, zio_link_t *zl) 483{ 484 ASSERT(zl->zl_parent == pio); 485 ASSERT(zl->zl_child == cio); 486 487 mutex_enter(&cio->io_lock); 488 mutex_enter(&pio->io_lock); 489 490 list_remove(&pio->io_child_list, zl); 491 list_remove(&cio->io_parent_list, zl); 492 493 pio->io_child_count--; 494 cio->io_parent_count--; 495 496 mutex_exit(&pio->io_lock); 497 mutex_exit(&cio->io_lock); 498 499 kmem_cache_free(zio_link_cache, zl); 500} 501 502static boolean_t 503zio_wait_for_children(zio_t *zio, enum zio_child child, enum zio_wait_type wait) 504{ 505 uint64_t *countp = &zio->io_children[child][wait]; 506 boolean_t waiting = B_FALSE; 507 508 mutex_enter(&zio->io_lock); 509 ASSERT(zio->io_stall == NULL); 510 if (*countp != 0) { 511 zio->io_stage >>= 1; 512 zio->io_stall = countp; 513 waiting = B_TRUE; 514 } 515 mutex_exit(&zio->io_lock); 516 517 return (waiting); 518} 519 520static void 521zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait) 522{ 523 uint64_t *countp = &pio->io_children[zio->io_child_type][wait]; 524 int *errorp = &pio->io_child_error[zio->io_child_type]; 525 526 mutex_enter(&pio->io_lock); 527 if (zio->io_error && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE)) 528 *errorp = zio_worst_error(*errorp, zio->io_error); 529 pio->io_reexecute |= zio->io_reexecute; 530 ASSERT3U(*countp, >, 0); 531 532 (*countp)--; 533 534 if (*countp == 0 && pio->io_stall == countp) { 535 pio->io_stall = NULL; 536 mutex_exit(&pio->io_lock); 537 zio_execute(pio); 538 } else { 539 mutex_exit(&pio->io_lock); 540 } 541} 542 543static void 544zio_inherit_child_errors(zio_t *zio, enum zio_child c) 545{ 546 if (zio->io_child_error[c] != 0 && zio->io_error == 0) 547 zio->io_error = zio->io_child_error[c]; 548} 549 550/* 551 * ========================================================================== 552 * Create the various types of I/O (read, write, free, etc) 553 * ========================================================================== 554 */ 555static zio_t * 556zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 557 void *data, uint64_t size, zio_done_func_t *done, void *private, 558 zio_type_t type, zio_priority_t priority, enum zio_flag flags, 559 vdev_t *vd, uint64_t offset, const zbookmark_phys_t *zb, 560 enum zio_stage stage, enum zio_stage pipeline) 561{ 562 zio_t *zio; 563 564 ASSERT3U(type == ZIO_TYPE_FREE || size, <=, SPA_MAXBLOCKSIZE); 565 ASSERT(P2PHASE(size, SPA_MINBLOCKSIZE) == 0); 566 ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0); 567 568 ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER)); 569 ASSERT(!bp || !(flags & ZIO_FLAG_CONFIG_WRITER)); 570 ASSERT(vd || stage == ZIO_STAGE_OPEN); 571 572 zio = kmem_cache_alloc(zio_cache, KM_SLEEP); 573 bzero(zio, sizeof (zio_t)); 574 575 mutex_init(&zio->io_lock, NULL, MUTEX_DEFAULT, NULL); 576 cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL); 577 578 list_create(&zio->io_parent_list, sizeof (zio_link_t), 579 offsetof(zio_link_t, zl_parent_node)); 580 list_create(&zio->io_child_list, sizeof (zio_link_t), 581 offsetof(zio_link_t, zl_child_node)); 582 583 if (vd != NULL) 584 zio->io_child_type = ZIO_CHILD_VDEV; 585 else if (flags & ZIO_FLAG_GANG_CHILD) 586 zio->io_child_type = ZIO_CHILD_GANG; 587 else if (flags & ZIO_FLAG_DDT_CHILD) 588 zio->io_child_type = ZIO_CHILD_DDT; 589 else 590 zio->io_child_type = ZIO_CHILD_LOGICAL; 591 592 if (bp != NULL) { 593 zio->io_bp = (blkptr_t *)bp; 594 zio->io_bp_copy = *bp; 595 zio->io_bp_orig = *bp; 596 if (type != ZIO_TYPE_WRITE || 597 zio->io_child_type == ZIO_CHILD_DDT) 598 zio->io_bp = &zio->io_bp_copy; /* so caller can free */ 599 if (zio->io_child_type == ZIO_CHILD_LOGICAL) 600 zio->io_logical = zio; 601 if (zio->io_child_type > ZIO_CHILD_GANG && BP_IS_GANG(bp)) 602 pipeline |= ZIO_GANG_STAGES; 603 } 604 605 zio->io_spa = spa; 606 zio->io_txg = txg; 607 zio->io_done = done; 608 zio->io_private = private; 609 zio->io_type = type; 610 zio->io_priority = priority; 611 zio->io_vd = vd; 612 zio->io_offset = offset; 613 zio->io_orig_data = zio->io_data = data; 614 zio->io_orig_size = zio->io_size = size; 615 zio->io_orig_flags = zio->io_flags = flags; 616 zio->io_orig_stage = zio->io_stage = stage; 617 zio->io_orig_pipeline = zio->io_pipeline = pipeline; 618 619 zio->io_state[ZIO_WAIT_READY] = (stage >= ZIO_STAGE_READY); 620 zio->io_state[ZIO_WAIT_DONE] = (stage >= ZIO_STAGE_DONE); 621 622 if (zb != NULL) 623 zio->io_bookmark = *zb; 624 625 if (pio != NULL) { 626 if (zio->io_logical == NULL) 627 zio->io_logical = pio->io_logical; 628 if (zio->io_child_type == ZIO_CHILD_GANG) 629 zio->io_gang_leader = pio->io_gang_leader; 630 zio_add_child(pio, zio); 631 } 632 633 return (zio); 634} 635 636static void 637zio_destroy(zio_t *zio) 638{ 639 list_destroy(&zio->io_parent_list); 640 list_destroy(&zio->io_child_list); 641 mutex_destroy(&zio->io_lock); 642 cv_destroy(&zio->io_cv); 643 kmem_cache_free(zio_cache, zio); 644} 645 646zio_t * 647zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, zio_done_func_t *done, 648 void *private, enum zio_flag flags) 649{ 650 zio_t *zio; 651 652 zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private, 653 ZIO_TYPE_NULL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL, 654 ZIO_STAGE_OPEN, ZIO_INTERLOCK_PIPELINE); 655 656 return (zio); 657} 658 659zio_t * 660zio_root(spa_t *spa, zio_done_func_t *done, void *private, enum zio_flag flags) 661{ 662 return (zio_null(NULL, spa, NULL, done, private, flags)); 663} 664 665void 666zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp) 667{ 668 if (!DMU_OT_IS_VALID(BP_GET_TYPE(bp))) { 669 zfs_panic_recover("blkptr at %p has invalid TYPE %llu", 670 bp, (longlong_t)BP_GET_TYPE(bp)); 671 } 672 if (BP_GET_CHECKSUM(bp) >= ZIO_CHECKSUM_FUNCTIONS || 673 BP_GET_CHECKSUM(bp) <= ZIO_CHECKSUM_ON) { 674 zfs_panic_recover("blkptr at %p has invalid CHECKSUM %llu", 675 bp, (longlong_t)BP_GET_CHECKSUM(bp)); 676 } 677 if (BP_GET_COMPRESS(bp) >= ZIO_COMPRESS_FUNCTIONS || 678 BP_GET_COMPRESS(bp) <= ZIO_COMPRESS_ON) { 679 zfs_panic_recover("blkptr at %p has invalid COMPRESS %llu", 680 bp, (longlong_t)BP_GET_COMPRESS(bp)); 681 } 682 if (BP_GET_LSIZE(bp) > SPA_MAXBLOCKSIZE) { 683 zfs_panic_recover("blkptr at %p has invalid LSIZE %llu", 684 bp, (longlong_t)BP_GET_LSIZE(bp)); 685 } 686 if (BP_GET_PSIZE(bp) > SPA_MAXBLOCKSIZE) { 687 zfs_panic_recover("blkptr at %p has invalid PSIZE %llu", 688 bp, (longlong_t)BP_GET_PSIZE(bp)); 689 } 690 691 if (BP_IS_EMBEDDED(bp)) { 692 if (BPE_GET_ETYPE(bp) > NUM_BP_EMBEDDED_TYPES) { 693 zfs_panic_recover("blkptr at %p has invalid ETYPE %llu", 694 bp, (longlong_t)BPE_GET_ETYPE(bp)); 695 } 696 } 697 698 /* 699 * Pool-specific checks. 700 * 701 * Note: it would be nice to verify that the blk_birth and 702 * BP_PHYSICAL_BIRTH() are not too large. However, spa_freeze() 703 * allows the birth time of log blocks (and dmu_sync()-ed blocks 704 * that are in the log) to be arbitrarily large. 705 */ 706 for (int i = 0; i < BP_GET_NDVAS(bp); i++) { 707 uint64_t vdevid = DVA_GET_VDEV(&bp->blk_dva[i]); 708 if (vdevid >= spa->spa_root_vdev->vdev_children) { 709 zfs_panic_recover("blkptr at %p DVA %u has invalid " 710 "VDEV %llu", 711 bp, i, (longlong_t)vdevid); 712 continue; 713 } 714 vdev_t *vd = spa->spa_root_vdev->vdev_child[vdevid]; 715 if (vd == NULL) { 716 zfs_panic_recover("blkptr at %p DVA %u has invalid " 717 "VDEV %llu", 718 bp, i, (longlong_t)vdevid); 719 continue; 720 } 721 if (vd->vdev_ops == &vdev_hole_ops) { 722 zfs_panic_recover("blkptr at %p DVA %u has hole " 723 "VDEV %llu", 724 bp, i, (longlong_t)vdevid); 725 continue; 726 } 727 if (vd->vdev_ops == &vdev_missing_ops) { 728 /* 729 * "missing" vdevs are valid during import, but we 730 * don't have their detailed info (e.g. asize), so 731 * we can't perform any more checks on them. 732 */ 733 continue; 734 } 735 uint64_t offset = DVA_GET_OFFSET(&bp->blk_dva[i]); 736 uint64_t asize = DVA_GET_ASIZE(&bp->blk_dva[i]); 737 if (BP_IS_GANG(bp)) 738 asize = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE); 739 if (offset + asize > vd->vdev_asize) { 740 zfs_panic_recover("blkptr at %p DVA %u has invalid " 741 "OFFSET %llu", 742 bp, i, (longlong_t)offset); 743 } 744 } 745} 746 747zio_t * 748zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, 749 void *data, uint64_t size, zio_done_func_t *done, void *private, 750 zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb) 751{ 752 zio_t *zio; 753 754 zfs_blkptr_verify(spa, bp); 755 756 zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp, 757 data, size, done, private, 758 ZIO_TYPE_READ, priority, flags, NULL, 0, zb, 759 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 760 ZIO_DDT_CHILD_READ_PIPELINE : ZIO_READ_PIPELINE); 761 762 return (zio); 763} 764 765zio_t * 766zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, 767 void *data, uint64_t size, const zio_prop_t *zp, 768 zio_done_func_t *ready, zio_done_func_t *physdone, zio_done_func_t *done, 769 void *private, 770 zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb) 771{ 772 zio_t *zio; 773 774 ASSERT(zp->zp_checksum >= ZIO_CHECKSUM_OFF && 775 zp->zp_checksum < ZIO_CHECKSUM_FUNCTIONS && 776 zp->zp_compress >= ZIO_COMPRESS_OFF && 777 zp->zp_compress < ZIO_COMPRESS_FUNCTIONS && 778 DMU_OT_IS_VALID(zp->zp_type) && 779 zp->zp_level < 32 && 780 zp->zp_copies > 0 && 781 zp->zp_copies <= spa_max_replication(spa)); 782 783 zio = zio_create(pio, spa, txg, bp, data, size, done, private, 784 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 785 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 786 ZIO_DDT_CHILD_WRITE_PIPELINE : ZIO_WRITE_PIPELINE); 787 788 zio->io_ready = ready; 789 zio->io_physdone = physdone; 790 zio->io_prop = *zp; 791 792 /* 793 * Data can be NULL if we are going to call zio_write_override() to 794 * provide the already-allocated BP. But we may need the data to 795 * verify a dedup hit (if requested). In this case, don't try to 796 * dedup (just take the already-allocated BP verbatim). 797 */ 798 if (data == NULL && zio->io_prop.zp_dedup_verify) { 799 zio->io_prop.zp_dedup = zio->io_prop.zp_dedup_verify = B_FALSE; 800 } 801 802 return (zio); 803} 804 805zio_t * 806zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, void *data, 807 uint64_t size, zio_done_func_t *done, void *private, 808 zio_priority_t priority, enum zio_flag flags, zbookmark_phys_t *zb) 809{ 810 zio_t *zio; 811 812 zio = zio_create(pio, spa, txg, bp, data, size, done, private, 813 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 814 ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE); 815 816 return (zio); 817} 818 819void 820zio_write_override(zio_t *zio, blkptr_t *bp, int copies, boolean_t nopwrite) 821{ 822 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 823 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 824 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 825 ASSERT(zio->io_txg == spa_syncing_txg(zio->io_spa)); 826 827 /* 828 * We must reset the io_prop to match the values that existed 829 * when the bp was first written by dmu_sync() keeping in mind 830 * that nopwrite and dedup are mutually exclusive. 831 */ 832 zio->io_prop.zp_dedup = nopwrite ? B_FALSE : zio->io_prop.zp_dedup; 833 zio->io_prop.zp_nopwrite = nopwrite; 834 zio->io_prop.zp_copies = copies; 835 zio->io_bp_override = bp; 836} 837 838void 839zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp) 840{ 841 842 /* 843 * The check for EMBEDDED is a performance optimization. We 844 * process the free here (by ignoring it) rather than 845 * putting it on the list and then processing it in zio_free_sync(). 846 */ 847 if (BP_IS_EMBEDDED(bp)) 848 return; 849 metaslab_check_free(spa, bp); 850 851 /* 852 * Frees that are for the currently-syncing txg, are not going to be 853 * deferred, and which will not need to do a read (i.e. not GANG or 854 * DEDUP), can be processed immediately. Otherwise, put them on the 855 * in-memory list for later processing. 856 */ 857 if (zfs_trim_enabled || BP_IS_GANG(bp) || BP_GET_DEDUP(bp) || 858 txg != spa->spa_syncing_txg || 859 spa_sync_pass(spa) >= zfs_sync_pass_deferred_free) { 860 bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp); 861 } else { 862 VERIFY0(zio_wait(zio_free_sync(NULL, spa, txg, bp, 863 BP_GET_PSIZE(bp), 0))); 864 } 865} 866 867zio_t * 868zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 869 uint64_t size, enum zio_flag flags) 870{ 871 zio_t *zio; 872 enum zio_stage stage = ZIO_FREE_PIPELINE; 873 874 ASSERT(!BP_IS_HOLE(bp)); 875 ASSERT(spa_syncing_txg(spa) == txg); 876 ASSERT(spa_sync_pass(spa) < zfs_sync_pass_deferred_free); 877 878 if (BP_IS_EMBEDDED(bp)) 879 return (zio_null(pio, spa, NULL, NULL, NULL, 0)); 880 881 metaslab_check_free(spa, bp); 882 arc_freed(spa, bp); 883 884 if (zfs_trim_enabled) 885 stage |= ZIO_STAGE_ISSUE_ASYNC | ZIO_STAGE_VDEV_IO_START | 886 ZIO_STAGE_VDEV_IO_ASSESS; 887 /* 888 * GANG and DEDUP blocks can induce a read (for the gang block header, 889 * or the DDT), so issue them asynchronously so that this thread is 890 * not tied up. 891 */ 892 else if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp)) 893 stage |= ZIO_STAGE_ISSUE_ASYNC; 894 895 flags |= ZIO_FLAG_DONT_QUEUE; 896 897 zio = zio_create(pio, spa, txg, bp, NULL, size, 898 NULL, NULL, ZIO_TYPE_FREE, ZIO_PRIORITY_NOW, flags, 899 NULL, 0, NULL, ZIO_STAGE_OPEN, stage); 900 901 return (zio); 902} 903 904zio_t * 905zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 906 zio_done_func_t *done, void *private, enum zio_flag flags) 907{ 908 zio_t *zio; 909 910 dprintf_bp(bp, "claiming in txg %llu", txg); 911 912 if (BP_IS_EMBEDDED(bp)) 913 return (zio_null(pio, spa, NULL, NULL, NULL, 0)); 914 915 /* 916 * A claim is an allocation of a specific block. Claims are needed 917 * to support immediate writes in the intent log. The issue is that 918 * immediate writes contain committed data, but in a txg that was 919 * *not* committed. Upon opening the pool after an unclean shutdown, 920 * the intent log claims all blocks that contain immediate write data 921 * so that the SPA knows they're in use. 922 * 923 * All claims *must* be resolved in the first txg -- before the SPA 924 * starts allocating blocks -- so that nothing is allocated twice. 925 * If txg == 0 we just verify that the block is claimable. 926 */ 927 ASSERT3U(spa->spa_uberblock.ub_rootbp.blk_birth, <, spa_first_txg(spa)); 928 ASSERT(txg == spa_first_txg(spa) || txg == 0); 929 ASSERT(!BP_GET_DEDUP(bp) || !spa_writeable(spa)); /* zdb(1M) */ 930 931 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 932 done, private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW, flags, 933 NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE); 934 935 return (zio); 936} 937 938zio_t * 939zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd, uint64_t offset, 940 uint64_t size, zio_done_func_t *done, void *private, 941 zio_priority_t priority, enum zio_flag flags) 942{ 943 zio_t *zio; 944 int c; 945 946 if (vd->vdev_children == 0) { 947 zio = zio_create(pio, spa, 0, NULL, NULL, size, done, private, 948 ZIO_TYPE_IOCTL, priority, flags, vd, offset, NULL, 949 ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE); 950 951 zio->io_cmd = cmd; 952 } else { 953 zio = zio_null(pio, spa, NULL, NULL, NULL, flags); 954 955 for (c = 0; c < vd->vdev_children; c++) 956 zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd, 957 offset, size, done, private, priority, flags)); 958 } 959 960 return (zio); 961} 962 963zio_t * 964zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 965 void *data, int checksum, zio_done_func_t *done, void *private, 966 zio_priority_t priority, enum zio_flag flags, boolean_t labels) 967{ 968 zio_t *zio; 969 970 ASSERT(vd->vdev_children == 0); 971 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 972 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 973 ASSERT3U(offset + size, <=, vd->vdev_psize); 974 975 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private, 976 ZIO_TYPE_READ, priority, flags | ZIO_FLAG_PHYSICAL, vd, offset, 977 NULL, ZIO_STAGE_OPEN, ZIO_READ_PHYS_PIPELINE); 978 979 zio->io_prop.zp_checksum = checksum; 980 981 return (zio); 982} 983 984zio_t * 985zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 986 void *data, int checksum, zio_done_func_t *done, void *private, 987 zio_priority_t priority, enum zio_flag flags, boolean_t labels) 988{ 989 zio_t *zio; 990 991 ASSERT(vd->vdev_children == 0); 992 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 993 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 994 ASSERT3U(offset + size, <=, vd->vdev_psize); 995 996 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private, 997 ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_PHYSICAL, vd, offset, 998 NULL, ZIO_STAGE_OPEN, ZIO_WRITE_PHYS_PIPELINE); 999 1000 zio->io_prop.zp_checksum = checksum; 1001 1002 if (zio_checksum_table[checksum].ci_eck) { 1003 /* 1004 * zec checksums are necessarily destructive -- they modify 1005 * the end of the write buffer to hold the verifier/checksum. 1006 * Therefore, we must make a local copy in case the data is 1007 * being written to multiple places in parallel. 1008 */ 1009 void *wbuf = zio_buf_alloc(size); 1010 bcopy(data, wbuf, size); 1011 zio_push_transform(zio, wbuf, size, size, NULL); 1012 } 1013 1014 return (zio); 1015} 1016 1017/* 1018 * Create a child I/O to do some work for us. 1019 */ 1020zio_t * 1021zio_vdev_child_io(zio_t *pio, blkptr_t *bp, vdev_t *vd, uint64_t offset, 1022 void *data, uint64_t size, int type, zio_priority_t priority, 1023 enum zio_flag flags, zio_done_func_t *done, void *private) 1024{ 1025 enum zio_stage pipeline = ZIO_VDEV_CHILD_PIPELINE; 1026 zio_t *zio; 1027 1028 ASSERT(vd->vdev_parent == 1029 (pio->io_vd ? pio->io_vd : pio->io_spa->spa_root_vdev)); 1030 1031 if (type == ZIO_TYPE_READ && bp != NULL) { 1032 /* 1033 * If we have the bp, then the child should perform the 1034 * checksum and the parent need not. This pushes error 1035 * detection as close to the leaves as possible and 1036 * eliminates redundant checksums in the interior nodes. 1037 */ 1038 pipeline |= ZIO_STAGE_CHECKSUM_VERIFY; 1039 pio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 1040 } 1041 1042 /* Not all IO types require vdev io done stage e.g. free */ 1043 if (!(pio->io_pipeline & ZIO_STAGE_VDEV_IO_DONE)) 1044 pipeline &= ~ZIO_STAGE_VDEV_IO_DONE; 1045 1046 if (vd->vdev_children == 0) 1047 offset += VDEV_LABEL_START_SIZE; 1048 1049 flags |= ZIO_VDEV_CHILD_FLAGS(pio) | ZIO_FLAG_DONT_PROPAGATE; 1050 1051 /* 1052 * If we've decided to do a repair, the write is not speculative -- 1053 * even if the original read was. 1054 */ 1055 if (flags & ZIO_FLAG_IO_REPAIR) 1056 flags &= ~ZIO_FLAG_SPECULATIVE; 1057 1058 zio = zio_create(pio, pio->io_spa, pio->io_txg, bp, data, size, 1059 done, private, type, priority, flags, vd, offset, &pio->io_bookmark, 1060 ZIO_STAGE_VDEV_IO_START >> 1, pipeline); 1061 1062 zio->io_physdone = pio->io_physdone; 1063 if (vd->vdev_ops->vdev_op_leaf && zio->io_logical != NULL) 1064 zio->io_logical->io_phys_children++; 1065 1066 return (zio); 1067} 1068 1069zio_t * 1070zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, void *data, uint64_t size, 1071 int type, zio_priority_t priority, enum zio_flag flags, 1072 zio_done_func_t *done, void *private) 1073{ 1074 zio_t *zio; 1075 1076 ASSERT(vd->vdev_ops->vdev_op_leaf); 1077 1078 zio = zio_create(NULL, vd->vdev_spa, 0, NULL, 1079 data, size, done, private, type, priority, 1080 flags | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY | ZIO_FLAG_DELEGATED, 1081 vd, offset, NULL, 1082 ZIO_STAGE_VDEV_IO_START >> 1, ZIO_VDEV_CHILD_PIPELINE); 1083 1084 return (zio); 1085} 1086 1087void 1088zio_flush(zio_t *zio, vdev_t *vd) 1089{ 1090 zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE, 0, 0, 1091 NULL, NULL, ZIO_PRIORITY_NOW, 1092 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY)); 1093} 1094 1095zio_t * 1096zio_trim(zio_t *zio, spa_t *spa, vdev_t *vd, uint64_t offset, uint64_t size) 1097{ 1098 1099 ASSERT(vd->vdev_ops->vdev_op_leaf); 1100 1101 return (zio_create(zio, spa, 0, NULL, NULL, size, NULL, NULL, 1102 ZIO_TYPE_FREE, ZIO_PRIORITY_TRIM, ZIO_FLAG_DONT_AGGREGATE | 1103 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY, 1104 vd, offset, NULL, ZIO_STAGE_OPEN, ZIO_FREE_PHYS_PIPELINE)); 1105} 1106 1107void 1108zio_shrink(zio_t *zio, uint64_t size) 1109{ 1110 ASSERT(zio->io_executor == NULL); 1111 ASSERT(zio->io_orig_size == zio->io_size); 1112 ASSERT(size <= zio->io_size); 1113 1114 /* 1115 * We don't shrink for raidz because of problems with the 1116 * reconstruction when reading back less than the block size. 1117 * Note, BP_IS_RAIDZ() assumes no compression. 1118 */ 1119 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 1120 if (!BP_IS_RAIDZ(zio->io_bp)) 1121 zio->io_orig_size = zio->io_size = size; 1122} 1123 1124/* 1125 * ========================================================================== 1126 * Prepare to read and write logical blocks 1127 * ========================================================================== 1128 */ 1129 1130static int 1131zio_read_bp_init(zio_t *zio) 1132{ 1133 blkptr_t *bp = zio->io_bp; 1134 1135 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF && 1136 zio->io_child_type == ZIO_CHILD_LOGICAL && 1137 !(zio->io_flags & ZIO_FLAG_RAW)) { 1138 uint64_t psize = 1139 BP_IS_EMBEDDED(bp) ? BPE_GET_PSIZE(bp) : BP_GET_PSIZE(bp); 1140 void *cbuf = zio_buf_alloc(psize); 1141 1142 zio_push_transform(zio, cbuf, psize, psize, zio_decompress); 1143 } 1144 1145 if (BP_IS_EMBEDDED(bp) && BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA) { 1146 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1147 decode_embedded_bp_compressed(bp, zio->io_data); 1148 } else { 1149 ASSERT(!BP_IS_EMBEDDED(bp)); 1150 } 1151 1152 if (!DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) && BP_GET_LEVEL(bp) == 0) 1153 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 1154 1155 if (BP_GET_TYPE(bp) == DMU_OT_DDT_ZAP) 1156 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 1157 1158 if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL) 1159 zio->io_pipeline = ZIO_DDT_READ_PIPELINE; 1160 1161 return (ZIO_PIPELINE_CONTINUE); 1162} 1163 1164static int 1165zio_write_bp_init(zio_t *zio) 1166{ 1167 spa_t *spa = zio->io_spa; 1168 zio_prop_t *zp = &zio->io_prop; 1169 enum zio_compress compress = zp->zp_compress; 1170 blkptr_t *bp = zio->io_bp; 1171 uint64_t lsize = zio->io_size; 1172 uint64_t psize = lsize; 1173 int pass = 1; 1174 1175 /* 1176 * If our children haven't all reached the ready stage, 1177 * wait for them and then repeat this pipeline stage. 1178 */ 1179 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 1180 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_READY)) 1181 return (ZIO_PIPELINE_STOP); 1182 1183 if (!IO_IS_ALLOCATING(zio)) 1184 return (ZIO_PIPELINE_CONTINUE); 1185 1186 ASSERT(zio->io_child_type != ZIO_CHILD_DDT); 1187 1188 if (zio->io_bp_override) { 1189 ASSERT(bp->blk_birth != zio->io_txg); 1190 ASSERT(BP_GET_DEDUP(zio->io_bp_override) == 0); 1191 1192 *bp = *zio->io_bp_override; 1193 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1194 1195 if (BP_IS_EMBEDDED(bp)) 1196 return (ZIO_PIPELINE_CONTINUE); 1197 1198 /* 1199 * If we've been overridden and nopwrite is set then 1200 * set the flag accordingly to indicate that a nopwrite 1201 * has already occurred. 1202 */ 1203 if (!BP_IS_HOLE(bp) && zp->zp_nopwrite) { 1204 ASSERT(!zp->zp_dedup); 1205 zio->io_flags |= ZIO_FLAG_NOPWRITE; 1206 return (ZIO_PIPELINE_CONTINUE); 1207 } 1208 1209 ASSERT(!zp->zp_nopwrite); 1210 1211 if (BP_IS_HOLE(bp) || !zp->zp_dedup) 1212 return (ZIO_PIPELINE_CONTINUE); 1213 1214 ASSERT(zio_checksum_table[zp->zp_checksum].ci_dedup || 1215 zp->zp_dedup_verify); 1216 1217 if (BP_GET_CHECKSUM(bp) == zp->zp_checksum) { 1218 BP_SET_DEDUP(bp, 1); 1219 zio->io_pipeline |= ZIO_STAGE_DDT_WRITE; 1220 return (ZIO_PIPELINE_CONTINUE); 1221 } 1222 } 1223 1224 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg) { 1225 /* 1226 * We're rewriting an existing block, which means we're 1227 * working on behalf of spa_sync(). For spa_sync() to 1228 * converge, it must eventually be the case that we don't 1229 * have to allocate new blocks. But compression changes 1230 * the blocksize, which forces a reallocate, and makes 1231 * convergence take longer. Therefore, after the first 1232 * few passes, stop compressing to ensure convergence. 1233 */ 1234 pass = spa_sync_pass(spa); 1235 1236 ASSERT(zio->io_txg == spa_syncing_txg(spa)); 1237 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1238 ASSERT(!BP_GET_DEDUP(bp)); 1239 1240 if (pass >= zfs_sync_pass_dont_compress) 1241 compress = ZIO_COMPRESS_OFF; 1242 1243 /* Make sure someone doesn't change their mind on overwrites */ 1244 ASSERT(BP_IS_EMBEDDED(bp) || MIN(zp->zp_copies + BP_IS_GANG(bp), 1245 spa_max_replication(spa)) == BP_GET_NDVAS(bp)); 1246 } 1247 1248 if (compress != ZIO_COMPRESS_OFF) { 1249 void *cbuf = zio_buf_alloc(lsize); 1250 psize = zio_compress_data(compress, zio->io_data, cbuf, lsize); 1251 if (psize == 0 || psize == lsize) { 1252 compress = ZIO_COMPRESS_OFF; 1253 zio_buf_free(cbuf, lsize); 1254 } else if (!zp->zp_dedup && psize <= BPE_PAYLOAD_SIZE && 1255 zp->zp_level == 0 && !DMU_OT_HAS_FILL(zp->zp_type) && 1256 spa_feature_is_enabled(spa, SPA_FEATURE_EMBEDDED_DATA)) { 1257 encode_embedded_bp_compressed(bp, 1258 cbuf, compress, lsize, psize); 1259 BPE_SET_ETYPE(bp, BP_EMBEDDED_TYPE_DATA); 1260 BP_SET_TYPE(bp, zio->io_prop.zp_type); 1261 BP_SET_LEVEL(bp, zio->io_prop.zp_level); 1262 zio_buf_free(cbuf, lsize); 1263 bp->blk_birth = zio->io_txg; 1264 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1265 ASSERT(spa_feature_is_active(spa, 1266 SPA_FEATURE_EMBEDDED_DATA)); 1267 return (ZIO_PIPELINE_CONTINUE); 1268 } else { 1269 /* 1270 * Round up compressed size up to the ashift 1271 * of the smallest-ashift device, and zero the tail. 1272 * This ensures that the compressed size of the BP 1273 * (and thus compressratio property) are correct, 1274 * in that we charge for the padding used to fill out 1275 * the last sector. 1276 */ 1277 ASSERT3U(spa->spa_min_ashift, >=, SPA_MINBLOCKSHIFT); 1278 size_t rounded = (size_t)P2ROUNDUP(psize, 1279 1ULL << spa->spa_min_ashift); 1280 if (rounded >= lsize) { 1281 compress = ZIO_COMPRESS_OFF; 1282 zio_buf_free(cbuf, lsize); 1283 psize = lsize; 1284 } else { 1285 bzero((char *)cbuf + psize, rounded - psize); 1286 psize = rounded; 1287 zio_push_transform(zio, cbuf, 1288 psize, lsize, NULL); 1289 } 1290 } 1291 } 1292 1293 /* 1294 * The final pass of spa_sync() must be all rewrites, but the first 1295 * few passes offer a trade-off: allocating blocks defers convergence, 1296 * but newly allocated blocks are sequential, so they can be written 1297 * to disk faster. Therefore, we allow the first few passes of 1298 * spa_sync() to allocate new blocks, but force rewrites after that. 1299 * There should only be a handful of blocks after pass 1 in any case. 1300 */ 1301 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg && 1302 BP_GET_PSIZE(bp) == psize && 1303 pass >= zfs_sync_pass_rewrite) { 1304 ASSERT(psize != 0); 1305 enum zio_stage gang_stages = zio->io_pipeline & ZIO_GANG_STAGES; 1306 zio->io_pipeline = ZIO_REWRITE_PIPELINE | gang_stages; 1307 zio->io_flags |= ZIO_FLAG_IO_REWRITE; 1308 } else { 1309 BP_ZERO(bp); 1310 zio->io_pipeline = ZIO_WRITE_PIPELINE; 1311 } 1312 1313 if (psize == 0) { 1314 if (zio->io_bp_orig.blk_birth != 0 && 1315 spa_feature_is_active(spa, SPA_FEATURE_HOLE_BIRTH)) { 1316 BP_SET_LSIZE(bp, lsize); 1317 BP_SET_TYPE(bp, zp->zp_type); 1318 BP_SET_LEVEL(bp, zp->zp_level); 1319 BP_SET_BIRTH(bp, zio->io_txg, 0); 1320 } 1321 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1322 } else { 1323 ASSERT(zp->zp_checksum != ZIO_CHECKSUM_GANG_HEADER); 1324 BP_SET_LSIZE(bp, lsize); 1325 BP_SET_TYPE(bp, zp->zp_type); 1326 BP_SET_LEVEL(bp, zp->zp_level); 1327 BP_SET_PSIZE(bp, psize); 1328 BP_SET_COMPRESS(bp, compress); 1329 BP_SET_CHECKSUM(bp, zp->zp_checksum); 1330 BP_SET_DEDUP(bp, zp->zp_dedup); 1331 BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER); 1332 if (zp->zp_dedup) { 1333 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1334 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1335 zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE; 1336 } 1337 if (zp->zp_nopwrite) { 1338 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1339 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1340 zio->io_pipeline |= ZIO_STAGE_NOP_WRITE; 1341 } 1342 } 1343 1344 return (ZIO_PIPELINE_CONTINUE); 1345} 1346 1347static int 1348zio_free_bp_init(zio_t *zio) 1349{ 1350 blkptr_t *bp = zio->io_bp; 1351 1352 if (zio->io_child_type == ZIO_CHILD_LOGICAL) { 1353 if (BP_GET_DEDUP(bp)) 1354 zio->io_pipeline = ZIO_DDT_FREE_PIPELINE; 1355 } 1356 1357 return (ZIO_PIPELINE_CONTINUE); 1358} 1359 1360/* 1361 * ========================================================================== 1362 * Execute the I/O pipeline 1363 * ========================================================================== 1364 */ 1365 1366static void 1367zio_taskq_dispatch(zio_t *zio, zio_taskq_type_t q, boolean_t cutinline) 1368{ 1369 spa_t *spa = zio->io_spa; 1370 zio_type_t t = zio->io_type; 1371 int flags = (cutinline ? TQ_FRONT : 0); 1372 1373 ASSERT(q == ZIO_TASKQ_ISSUE || q == ZIO_TASKQ_INTERRUPT); 1374 1375 /* 1376 * If we're a config writer or a probe, the normal issue and 1377 * interrupt threads may all be blocked waiting for the config lock. 1378 * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL. 1379 */ 1380 if (zio->io_flags & (ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_PROBE)) 1381 t = ZIO_TYPE_NULL; 1382 1383 /* 1384 * A similar issue exists for the L2ARC write thread until L2ARC 2.0. 1385 */ 1386 if (t == ZIO_TYPE_WRITE && zio->io_vd && zio->io_vd->vdev_aux) 1387 t = ZIO_TYPE_NULL; 1388 1389 /* 1390 * If this is a high priority I/O, then use the high priority taskq if 1391 * available. 1392 */ 1393 if (zio->io_priority == ZIO_PRIORITY_NOW && 1394 spa->spa_zio_taskq[t][q + 1].stqs_count != 0) 1395 q++; 1396 1397 ASSERT3U(q, <, ZIO_TASKQ_TYPES); 1398 1399 /* 1400 * NB: We are assuming that the zio can only be dispatched 1401 * to a single taskq at a time. It would be a grievous error 1402 * to dispatch the zio to another taskq at the same time. 1403 */ 1404#if defined(illumos) || !defined(_KERNEL) 1405 ASSERT(zio->io_tqent.tqent_next == NULL); 1406#else 1407 ASSERT(zio->io_tqent.tqent_task.ta_pending == 0); 1408#endif 1409 spa_taskq_dispatch_ent(spa, t, q, (task_func_t *)zio_execute, zio, 1410 flags, &zio->io_tqent); 1411} 1412 1413static boolean_t 1414zio_taskq_member(zio_t *zio, zio_taskq_type_t q) 1415{ 1416 kthread_t *executor = zio->io_executor; 1417 spa_t *spa = zio->io_spa; 1418 1419 for (zio_type_t t = 0; t < ZIO_TYPES; t++) { 1420 spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q]; 1421 uint_t i; 1422 for (i = 0; i < tqs->stqs_count; i++) { 1423 if (taskq_member(tqs->stqs_taskq[i], executor)) 1424 return (B_TRUE); 1425 } 1426 } 1427 1428 return (B_FALSE); 1429} 1430 1431static int 1432zio_issue_async(zio_t *zio) 1433{ 1434 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 1435 1436 return (ZIO_PIPELINE_STOP); 1437} 1438 1439void 1440zio_interrupt(zio_t *zio) 1441{ 1442 zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE); 1443} 1444 1445/* 1446 * Execute the I/O pipeline until one of the following occurs: 1447 * 1448 * (1) the I/O completes 1449 * (2) the pipeline stalls waiting for dependent child I/Os 1450 * (3) the I/O issues, so we're waiting for an I/O completion interrupt 1451 * (4) the I/O is delegated by vdev-level caching or aggregation 1452 * (5) the I/O is deferred due to vdev-level queueing 1453 * (6) the I/O is handed off to another thread. 1454 * 1455 * In all cases, the pipeline stops whenever there's no CPU work; it never 1456 * burns a thread in cv_wait(). 1457 * 1458 * There's no locking on io_stage because there's no legitimate way 1459 * for multiple threads to be attempting to process the same I/O. 1460 */ 1461static zio_pipe_stage_t *zio_pipeline[]; 1462 1463void 1464zio_execute(zio_t *zio) 1465{ 1466 zio->io_executor = curthread; 1467 1468 while (zio->io_stage < ZIO_STAGE_DONE) { 1469 enum zio_stage pipeline = zio->io_pipeline; 1470 enum zio_stage stage = zio->io_stage; 1471 int rv; 1472 1473 ASSERT(!MUTEX_HELD(&zio->io_lock)); 1474 ASSERT(ISP2(stage)); 1475 ASSERT(zio->io_stall == NULL); 1476 1477 do { 1478 stage <<= 1; 1479 } while ((stage & pipeline) == 0); 1480 1481 ASSERT(stage <= ZIO_STAGE_DONE); 1482 1483 /* 1484 * If we are in interrupt context and this pipeline stage 1485 * will grab a config lock that is held across I/O, 1486 * or may wait for an I/O that needs an interrupt thread 1487 * to complete, issue async to avoid deadlock. 1488 * 1489 * For VDEV_IO_START, we cut in line so that the io will 1490 * be sent to disk promptly. 1491 */ 1492 if ((stage & ZIO_BLOCKING_STAGES) && zio->io_vd == NULL && 1493 zio_taskq_member(zio, ZIO_TASKQ_INTERRUPT)) { 1494 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ? 1495 zio_requeue_io_start_cut_in_line : B_FALSE; 1496 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut); 1497 return; 1498 } 1499 1500 zio->io_stage = stage; 1501 rv = zio_pipeline[highbit64(stage) - 1](zio); 1502 1503 if (rv == ZIO_PIPELINE_STOP) 1504 return; 1505 1506 ASSERT(rv == ZIO_PIPELINE_CONTINUE); 1507 } 1508} 1509 1510/* 1511 * ========================================================================== 1512 * Initiate I/O, either sync or async 1513 * ========================================================================== 1514 */ 1515int 1516zio_wait(zio_t *zio) 1517{ 1518 int error; 1519 1520 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 1521 ASSERT(zio->io_executor == NULL); 1522 1523 zio->io_waiter = curthread; 1524 1525 zio_execute(zio); 1526 1527 mutex_enter(&zio->io_lock); 1528 while (zio->io_executor != NULL) 1529 cv_wait(&zio->io_cv, &zio->io_lock); 1530 mutex_exit(&zio->io_lock); 1531 1532 error = zio->io_error; 1533 zio_destroy(zio); 1534 1535 return (error); 1536} 1537 1538void 1539zio_nowait(zio_t *zio) 1540{ 1541 ASSERT(zio->io_executor == NULL); 1542 1543 if (zio->io_child_type == ZIO_CHILD_LOGICAL && 1544 zio_unique_parent(zio) == NULL) { 1545 /* 1546 * This is a logical async I/O with no parent to wait for it. 1547 * We add it to the spa_async_root_zio "Godfather" I/O which 1548 * will ensure they complete prior to unloading the pool. 1549 */ 1550 spa_t *spa = zio->io_spa; 1551 1552 zio_add_child(spa->spa_async_zio_root[CPU_SEQID], zio); 1553 } 1554 1555 zio_execute(zio); 1556} 1557 1558/* 1559 * ========================================================================== 1560 * Reexecute or suspend/resume failed I/O 1561 * ========================================================================== 1562 */ 1563 1564static void 1565zio_reexecute(zio_t *pio) 1566{ 1567 zio_t *cio, *cio_next; 1568 1569 ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL); 1570 ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN); 1571 ASSERT(pio->io_gang_leader == NULL); 1572 ASSERT(pio->io_gang_tree == NULL); 1573 1574 pio->io_flags = pio->io_orig_flags; 1575 pio->io_stage = pio->io_orig_stage; 1576 pio->io_pipeline = pio->io_orig_pipeline; 1577 pio->io_reexecute = 0; 1578 pio->io_flags |= ZIO_FLAG_REEXECUTED; 1579 pio->io_error = 0; 1580 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1581 pio->io_state[w] = 0; 1582 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 1583 pio->io_child_error[c] = 0; 1584 1585 if (IO_IS_ALLOCATING(pio)) 1586 BP_ZERO(pio->io_bp); 1587 1588 /* 1589 * As we reexecute pio's children, new children could be created. 1590 * New children go to the head of pio's io_child_list, however, 1591 * so we will (correctly) not reexecute them. The key is that 1592 * the remainder of pio's io_child_list, from 'cio_next' onward, 1593 * cannot be affected by any side effects of reexecuting 'cio'. 1594 */ 1595 for (cio = zio_walk_children(pio); cio != NULL; cio = cio_next) { 1596 cio_next = zio_walk_children(pio); 1597 mutex_enter(&pio->io_lock); 1598 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1599 pio->io_children[cio->io_child_type][w]++; 1600 mutex_exit(&pio->io_lock); 1601 zio_reexecute(cio); 1602 } 1603 1604 /* 1605 * Now that all children have been reexecuted, execute the parent. 1606 * We don't reexecute "The Godfather" I/O here as it's the 1607 * responsibility of the caller to wait on him. 1608 */ 1609 if (!(pio->io_flags & ZIO_FLAG_GODFATHER)) 1610 zio_execute(pio); 1611} 1612 1613void 1614zio_suspend(spa_t *spa, zio_t *zio) 1615{ 1616 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC) 1617 fm_panic("Pool '%s' has encountered an uncorrectable I/O " 1618 "failure and the failure mode property for this pool " 1619 "is set to panic.", spa_name(spa)); 1620 1621 zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL, NULL, 0, 0); 1622 1623 mutex_enter(&spa->spa_suspend_lock); 1624 1625 if (spa->spa_suspend_zio_root == NULL) 1626 spa->spa_suspend_zio_root = zio_root(spa, NULL, NULL, 1627 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | 1628 ZIO_FLAG_GODFATHER); 1629 1630 spa->spa_suspended = B_TRUE; 1631 1632 if (zio != NULL) { 1633 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 1634 ASSERT(zio != spa->spa_suspend_zio_root); 1635 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1636 ASSERT(zio_unique_parent(zio) == NULL); 1637 ASSERT(zio->io_stage == ZIO_STAGE_DONE); 1638 zio_add_child(spa->spa_suspend_zio_root, zio); 1639 } 1640 1641 mutex_exit(&spa->spa_suspend_lock); 1642} 1643 1644int 1645zio_resume(spa_t *spa) 1646{ 1647 zio_t *pio; 1648 1649 /* 1650 * Reexecute all previously suspended i/o. 1651 */ 1652 mutex_enter(&spa->spa_suspend_lock); 1653 spa->spa_suspended = B_FALSE; 1654 cv_broadcast(&spa->spa_suspend_cv); 1655 pio = spa->spa_suspend_zio_root; 1656 spa->spa_suspend_zio_root = NULL; 1657 mutex_exit(&spa->spa_suspend_lock); 1658 1659 if (pio == NULL) 1660 return (0); 1661 1662 zio_reexecute(pio); 1663 return (zio_wait(pio)); 1664} 1665 1666void 1667zio_resume_wait(spa_t *spa) 1668{ 1669 mutex_enter(&spa->spa_suspend_lock); 1670 while (spa_suspended(spa)) 1671 cv_wait(&spa->spa_suspend_cv, &spa->spa_suspend_lock); 1672 mutex_exit(&spa->spa_suspend_lock); 1673} 1674 1675/* 1676 * ========================================================================== 1677 * Gang blocks. 1678 * 1679 * A gang block is a collection of small blocks that looks to the DMU 1680 * like one large block. When zio_dva_allocate() cannot find a block 1681 * of the requested size, due to either severe fragmentation or the pool 1682 * being nearly full, it calls zio_write_gang_block() to construct the 1683 * block from smaller fragments. 1684 * 1685 * A gang block consists of a gang header (zio_gbh_phys_t) and up to 1686 * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like 1687 * an indirect block: it's an array of block pointers. It consumes 1688 * only one sector and hence is allocatable regardless of fragmentation. 1689 * The gang header's bps point to its gang members, which hold the data. 1690 * 1691 * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg> 1692 * as the verifier to ensure uniqueness of the SHA256 checksum. 1693 * Critically, the gang block bp's blk_cksum is the checksum of the data, 1694 * not the gang header. This ensures that data block signatures (needed for 1695 * deduplication) are independent of how the block is physically stored. 1696 * 1697 * Gang blocks can be nested: a gang member may itself be a gang block. 1698 * Thus every gang block is a tree in which root and all interior nodes are 1699 * gang headers, and the leaves are normal blocks that contain user data. 1700 * The root of the gang tree is called the gang leader. 1701 * 1702 * To perform any operation (read, rewrite, free, claim) on a gang block, 1703 * zio_gang_assemble() first assembles the gang tree (minus data leaves) 1704 * in the io_gang_tree field of the original logical i/o by recursively 1705 * reading the gang leader and all gang headers below it. This yields 1706 * an in-core tree containing the contents of every gang header and the 1707 * bps for every constituent of the gang block. 1708 * 1709 * With the gang tree now assembled, zio_gang_issue() just walks the gang tree 1710 * and invokes a callback on each bp. To free a gang block, zio_gang_issue() 1711 * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp. 1712 * zio_claim_gang() provides a similarly trivial wrapper for zio_claim(). 1713 * zio_read_gang() is a wrapper around zio_read() that omits reading gang 1714 * headers, since we already have those in io_gang_tree. zio_rewrite_gang() 1715 * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite() 1716 * of the gang header plus zio_checksum_compute() of the data to update the 1717 * gang header's blk_cksum as described above. 1718 * 1719 * The two-phase assemble/issue model solves the problem of partial failure -- 1720 * what if you'd freed part of a gang block but then couldn't read the 1721 * gang header for another part? Assembling the entire gang tree first 1722 * ensures that all the necessary gang header I/O has succeeded before 1723 * starting the actual work of free, claim, or write. Once the gang tree 1724 * is assembled, free and claim are in-memory operations that cannot fail. 1725 * 1726 * In the event that a gang write fails, zio_dva_unallocate() walks the 1727 * gang tree to immediately free (i.e. insert back into the space map) 1728 * everything we've allocated. This ensures that we don't get ENOSPC 1729 * errors during repeated suspend/resume cycles due to a flaky device. 1730 * 1731 * Gang rewrites only happen during sync-to-convergence. If we can't assemble 1732 * the gang tree, we won't modify the block, so we can safely defer the free 1733 * (knowing that the block is still intact). If we *can* assemble the gang 1734 * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free 1735 * each constituent bp and we can allocate a new block on the next sync pass. 1736 * 1737 * In all cases, the gang tree allows complete recovery from partial failure. 1738 * ========================================================================== 1739 */ 1740 1741static zio_t * 1742zio_read_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1743{ 1744 if (gn != NULL) 1745 return (pio); 1746 1747 return (zio_read(pio, pio->io_spa, bp, data, BP_GET_PSIZE(bp), 1748 NULL, NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 1749 &pio->io_bookmark)); 1750} 1751 1752zio_t * 1753zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1754{ 1755 zio_t *zio; 1756 1757 if (gn != NULL) { 1758 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1759 gn->gn_gbh, SPA_GANGBLOCKSIZE, NULL, NULL, pio->io_priority, 1760 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1761 /* 1762 * As we rewrite each gang header, the pipeline will compute 1763 * a new gang block header checksum for it; but no one will 1764 * compute a new data checksum, so we do that here. The one 1765 * exception is the gang leader: the pipeline already computed 1766 * its data checksum because that stage precedes gang assembly. 1767 * (Presently, nothing actually uses interior data checksums; 1768 * this is just good hygiene.) 1769 */ 1770 if (gn != pio->io_gang_leader->io_gang_tree) { 1771 zio_checksum_compute(zio, BP_GET_CHECKSUM(bp), 1772 data, BP_GET_PSIZE(bp)); 1773 } 1774 /* 1775 * If we are here to damage data for testing purposes, 1776 * leave the GBH alone so that we can detect the damage. 1777 */ 1778 if (pio->io_gang_leader->io_flags & ZIO_FLAG_INDUCE_DAMAGE) 1779 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 1780 } else { 1781 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1782 data, BP_GET_PSIZE(bp), NULL, NULL, pio->io_priority, 1783 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1784 } 1785 1786 return (zio); 1787} 1788 1789/* ARGSUSED */ 1790zio_t * 1791zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1792{ 1793 return (zio_free_sync(pio, pio->io_spa, pio->io_txg, bp, 1794 BP_IS_GANG(bp) ? SPA_GANGBLOCKSIZE : BP_GET_PSIZE(bp), 1795 ZIO_GANG_CHILD_FLAGS(pio))); 1796} 1797 1798/* ARGSUSED */ 1799zio_t * 1800zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1801{ 1802 return (zio_claim(pio, pio->io_spa, pio->io_txg, bp, 1803 NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio))); 1804} 1805 1806static zio_gang_issue_func_t *zio_gang_issue_func[ZIO_TYPES] = { 1807 NULL, 1808 zio_read_gang, 1809 zio_rewrite_gang, 1810 zio_free_gang, 1811 zio_claim_gang, 1812 NULL 1813}; 1814 1815static void zio_gang_tree_assemble_done(zio_t *zio); 1816 1817static zio_gang_node_t * 1818zio_gang_node_alloc(zio_gang_node_t **gnpp) 1819{ 1820 zio_gang_node_t *gn; 1821 1822 ASSERT(*gnpp == NULL); 1823 1824 gn = kmem_zalloc(sizeof (*gn), KM_SLEEP); 1825 gn->gn_gbh = zio_buf_alloc(SPA_GANGBLOCKSIZE); 1826 *gnpp = gn; 1827 1828 return (gn); 1829} 1830 1831static void 1832zio_gang_node_free(zio_gang_node_t **gnpp) 1833{ 1834 zio_gang_node_t *gn = *gnpp; 1835 1836 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 1837 ASSERT(gn->gn_child[g] == NULL); 1838 1839 zio_buf_free(gn->gn_gbh, SPA_GANGBLOCKSIZE); 1840 kmem_free(gn, sizeof (*gn)); 1841 *gnpp = NULL; 1842} 1843 1844static void 1845zio_gang_tree_free(zio_gang_node_t **gnpp) 1846{ 1847 zio_gang_node_t *gn = *gnpp; 1848 1849 if (gn == NULL) 1850 return; 1851 1852 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 1853 zio_gang_tree_free(&gn->gn_child[g]); 1854 1855 zio_gang_node_free(gnpp); 1856} 1857 1858static void 1859zio_gang_tree_assemble(zio_t *gio, blkptr_t *bp, zio_gang_node_t **gnpp) 1860{ 1861 zio_gang_node_t *gn = zio_gang_node_alloc(gnpp); 1862 1863 ASSERT(gio->io_gang_leader == gio); 1864 ASSERT(BP_IS_GANG(bp)); 1865 1866 zio_nowait(zio_read(gio, gio->io_spa, bp, gn->gn_gbh, 1867 SPA_GANGBLOCKSIZE, zio_gang_tree_assemble_done, gn, 1868 gio->io_priority, ZIO_GANG_CHILD_FLAGS(gio), &gio->io_bookmark)); 1869} 1870 1871static void 1872zio_gang_tree_assemble_done(zio_t *zio) 1873{ 1874 zio_t *gio = zio->io_gang_leader; 1875 zio_gang_node_t *gn = zio->io_private; 1876 blkptr_t *bp = zio->io_bp; 1877 1878 ASSERT(gio == zio_unique_parent(zio)); 1879 ASSERT(zio->io_child_count == 0); 1880 1881 if (zio->io_error) 1882 return; 1883 1884 if (BP_SHOULD_BYTESWAP(bp)) 1885 byteswap_uint64_array(zio->io_data, zio->io_size); 1886 1887 ASSERT(zio->io_data == gn->gn_gbh); 1888 ASSERT(zio->io_size == SPA_GANGBLOCKSIZE); 1889 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 1890 1891 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 1892 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 1893 if (!BP_IS_GANG(gbp)) 1894 continue; 1895 zio_gang_tree_assemble(gio, gbp, &gn->gn_child[g]); 1896 } 1897} 1898 1899static void 1900zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, void *data) 1901{ 1902 zio_t *gio = pio->io_gang_leader; 1903 zio_t *zio; 1904 1905 ASSERT(BP_IS_GANG(bp) == !!gn); 1906 ASSERT(BP_GET_CHECKSUM(bp) == BP_GET_CHECKSUM(gio->io_bp)); 1907 ASSERT(BP_GET_LSIZE(bp) == BP_GET_PSIZE(bp) || gn == gio->io_gang_tree); 1908 1909 /* 1910 * If you're a gang header, your data is in gn->gn_gbh. 1911 * If you're a gang member, your data is in 'data' and gn == NULL. 1912 */ 1913 zio = zio_gang_issue_func[gio->io_type](pio, bp, gn, data); 1914 1915 if (gn != NULL) { 1916 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 1917 1918 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 1919 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 1920 if (BP_IS_HOLE(gbp)) 1921 continue; 1922 zio_gang_tree_issue(zio, gn->gn_child[g], gbp, data); 1923 data = (char *)data + BP_GET_PSIZE(gbp); 1924 } 1925 } 1926 1927 if (gn == gio->io_gang_tree && gio->io_data != NULL) 1928 ASSERT3P((char *)gio->io_data + gio->io_size, ==, data); 1929 1930 if (zio != pio) 1931 zio_nowait(zio); 1932} 1933 1934static int 1935zio_gang_assemble(zio_t *zio) 1936{ 1937 blkptr_t *bp = zio->io_bp; 1938 1939 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == NULL); 1940 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 1941 1942 zio->io_gang_leader = zio; 1943 1944 zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree); 1945 1946 return (ZIO_PIPELINE_CONTINUE); 1947} 1948 1949static int 1950zio_gang_issue(zio_t *zio) 1951{ 1952 blkptr_t *bp = zio->io_bp; 1953 1954 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE)) 1955 return (ZIO_PIPELINE_STOP); 1956 1957 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio); 1958 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 1959 1960 if (zio->io_child_error[ZIO_CHILD_GANG] == 0) 1961 zio_gang_tree_issue(zio, zio->io_gang_tree, bp, zio->io_data); 1962 else 1963 zio_gang_tree_free(&zio->io_gang_tree); 1964 1965 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1966 1967 return (ZIO_PIPELINE_CONTINUE); 1968} 1969 1970static void 1971zio_write_gang_member_ready(zio_t *zio) 1972{ 1973 zio_t *pio = zio_unique_parent(zio); 1974 zio_t *gio = zio->io_gang_leader; 1975 dva_t *cdva = zio->io_bp->blk_dva; 1976 dva_t *pdva = pio->io_bp->blk_dva; 1977 uint64_t asize; 1978 1979 if (BP_IS_HOLE(zio->io_bp)) 1980 return; 1981 1982 ASSERT(BP_IS_HOLE(&zio->io_bp_orig)); 1983 1984 ASSERT(zio->io_child_type == ZIO_CHILD_GANG); 1985 ASSERT3U(zio->io_prop.zp_copies, ==, gio->io_prop.zp_copies); 1986 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp)); 1987 ASSERT3U(pio->io_prop.zp_copies, <=, BP_GET_NDVAS(pio->io_bp)); 1988 ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp)); 1989 1990 mutex_enter(&pio->io_lock); 1991 for (int d = 0; d < BP_GET_NDVAS(zio->io_bp); d++) { 1992 ASSERT(DVA_GET_GANG(&pdva[d])); 1993 asize = DVA_GET_ASIZE(&pdva[d]); 1994 asize += DVA_GET_ASIZE(&cdva[d]); 1995 DVA_SET_ASIZE(&pdva[d], asize); 1996 } 1997 mutex_exit(&pio->io_lock); 1998} 1999 2000static int 2001zio_write_gang_block(zio_t *pio) 2002{ 2003 spa_t *spa = pio->io_spa; 2004 blkptr_t *bp = pio->io_bp; 2005 zio_t *gio = pio->io_gang_leader; 2006 zio_t *zio; 2007 zio_gang_node_t *gn, **gnpp; 2008 zio_gbh_phys_t *gbh; 2009 uint64_t txg = pio->io_txg; 2010 uint64_t resid = pio->io_size; 2011 uint64_t lsize; 2012 int copies = gio->io_prop.zp_copies; 2013 int gbh_copies = MIN(copies + 1, spa_max_replication(spa)); 2014 zio_prop_t zp; 2015 int error; 2016 2017 error = metaslab_alloc(spa, spa_normal_class(spa), SPA_GANGBLOCKSIZE, 2018 bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp, 2019 METASLAB_HINTBP_FAVOR | METASLAB_GANG_HEADER); 2020 if (error) { 2021 pio->io_error = error; 2022 return (ZIO_PIPELINE_CONTINUE); 2023 } 2024 2025 if (pio == gio) { 2026 gnpp = &gio->io_gang_tree; 2027 } else { 2028 gnpp = pio->io_private; 2029 ASSERT(pio->io_ready == zio_write_gang_member_ready); 2030 } 2031 2032 gn = zio_gang_node_alloc(gnpp); 2033 gbh = gn->gn_gbh; 2034 bzero(gbh, SPA_GANGBLOCKSIZE); 2035 2036 /* 2037 * Create the gang header. 2038 */ 2039 zio = zio_rewrite(pio, spa, txg, bp, gbh, SPA_GANGBLOCKSIZE, NULL, NULL, 2040 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 2041 2042 /* 2043 * Create and nowait the gang children. 2044 */ 2045 for (int g = 0; resid != 0; resid -= lsize, g++) { 2046 lsize = P2ROUNDUP(resid / (SPA_GBH_NBLKPTRS - g), 2047 SPA_MINBLOCKSIZE); 2048 ASSERT(lsize >= SPA_MINBLOCKSIZE && lsize <= resid); 2049 2050 zp.zp_checksum = gio->io_prop.zp_checksum; 2051 zp.zp_compress = ZIO_COMPRESS_OFF; 2052 zp.zp_type = DMU_OT_NONE; 2053 zp.zp_level = 0; 2054 zp.zp_copies = gio->io_prop.zp_copies; 2055 zp.zp_dedup = B_FALSE; 2056 zp.zp_dedup_verify = B_FALSE; 2057 zp.zp_nopwrite = B_FALSE; 2058 2059 zio_nowait(zio_write(zio, spa, txg, &gbh->zg_blkptr[g], 2060 (char *)pio->io_data + (pio->io_size - resid), lsize, &zp, 2061 zio_write_gang_member_ready, NULL, NULL, &gn->gn_child[g], 2062 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 2063 &pio->io_bookmark)); 2064 } 2065 2066 /* 2067 * Set pio's pipeline to just wait for zio to finish. 2068 */ 2069 pio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2070 2071 zio_nowait(zio); 2072 2073 return (ZIO_PIPELINE_CONTINUE); 2074} 2075 2076/* 2077 * The zio_nop_write stage in the pipeline determines if allocating 2078 * a new bp is necessary. By leveraging a cryptographically secure checksum, 2079 * such as SHA256, we can compare the checksums of the new data and the old 2080 * to determine if allocating a new block is required. The nopwrite 2081 * feature can handle writes in either syncing or open context (i.e. zil 2082 * writes) and as a result is mutually exclusive with dedup. 2083 */ 2084static int 2085zio_nop_write(zio_t *zio) 2086{ 2087 blkptr_t *bp = zio->io_bp; 2088 blkptr_t *bp_orig = &zio->io_bp_orig; 2089 zio_prop_t *zp = &zio->io_prop; 2090 2091 ASSERT(BP_GET_LEVEL(bp) == 0); 2092 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 2093 ASSERT(zp->zp_nopwrite); 2094 ASSERT(!zp->zp_dedup); 2095 ASSERT(zio->io_bp_override == NULL); 2096 ASSERT(IO_IS_ALLOCATING(zio)); 2097 2098 /* 2099 * Check to see if the original bp and the new bp have matching 2100 * characteristics (i.e. same checksum, compression algorithms, etc). 2101 * If they don't then just continue with the pipeline which will 2102 * allocate a new bp. 2103 */ 2104 if (BP_IS_HOLE(bp_orig) || 2105 !zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_dedup || 2106 BP_GET_CHECKSUM(bp) != BP_GET_CHECKSUM(bp_orig) || 2107 BP_GET_COMPRESS(bp) != BP_GET_COMPRESS(bp_orig) || 2108 BP_GET_DEDUP(bp) != BP_GET_DEDUP(bp_orig) || 2109 zp->zp_copies != BP_GET_NDVAS(bp_orig)) 2110 return (ZIO_PIPELINE_CONTINUE); 2111 2112 /* 2113 * If the checksums match then reset the pipeline so that we 2114 * avoid allocating a new bp and issuing any I/O. 2115 */ 2116 if (ZIO_CHECKSUM_EQUAL(bp->blk_cksum, bp_orig->blk_cksum)) { 2117 ASSERT(zio_checksum_table[zp->zp_checksum].ci_dedup); 2118 ASSERT3U(BP_GET_PSIZE(bp), ==, BP_GET_PSIZE(bp_orig)); 2119 ASSERT3U(BP_GET_LSIZE(bp), ==, BP_GET_LSIZE(bp_orig)); 2120 ASSERT(zp->zp_compress != ZIO_COMPRESS_OFF); 2121 ASSERT(bcmp(&bp->blk_prop, &bp_orig->blk_prop, 2122 sizeof (uint64_t)) == 0); 2123 2124 *bp = *bp_orig; 2125 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2126 zio->io_flags |= ZIO_FLAG_NOPWRITE; 2127 } 2128 2129 return (ZIO_PIPELINE_CONTINUE); 2130} 2131 2132/* 2133 * ========================================================================== 2134 * Dedup 2135 * ========================================================================== 2136 */ 2137static void 2138zio_ddt_child_read_done(zio_t *zio) 2139{ 2140 blkptr_t *bp = zio->io_bp; 2141 ddt_entry_t *dde = zio->io_private; 2142 ddt_phys_t *ddp; 2143 zio_t *pio = zio_unique_parent(zio); 2144 2145 mutex_enter(&pio->io_lock); 2146 ddp = ddt_phys_select(dde, bp); 2147 if (zio->io_error == 0) 2148 ddt_phys_clear(ddp); /* this ddp doesn't need repair */ 2149 if (zio->io_error == 0 && dde->dde_repair_data == NULL) 2150 dde->dde_repair_data = zio->io_data; 2151 else 2152 zio_buf_free(zio->io_data, zio->io_size); 2153 mutex_exit(&pio->io_lock); 2154} 2155 2156static int 2157zio_ddt_read_start(zio_t *zio) 2158{ 2159 blkptr_t *bp = zio->io_bp; 2160 2161 ASSERT(BP_GET_DEDUP(bp)); 2162 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 2163 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2164 2165 if (zio->io_child_error[ZIO_CHILD_DDT]) { 2166 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2167 ddt_entry_t *dde = ddt_repair_start(ddt, bp); 2168 ddt_phys_t *ddp = dde->dde_phys; 2169 ddt_phys_t *ddp_self = ddt_phys_select(dde, bp); 2170 blkptr_t blk; 2171 2172 ASSERT(zio->io_vsd == NULL); 2173 zio->io_vsd = dde; 2174 2175 if (ddp_self == NULL) 2176 return (ZIO_PIPELINE_CONTINUE); 2177 2178 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { 2179 if (ddp->ddp_phys_birth == 0 || ddp == ddp_self) 2180 continue; 2181 ddt_bp_create(ddt->ddt_checksum, &dde->dde_key, ddp, 2182 &blk); 2183 zio_nowait(zio_read(zio, zio->io_spa, &blk, 2184 zio_buf_alloc(zio->io_size), zio->io_size, 2185 zio_ddt_child_read_done, dde, zio->io_priority, 2186 ZIO_DDT_CHILD_FLAGS(zio) | ZIO_FLAG_DONT_PROPAGATE, 2187 &zio->io_bookmark)); 2188 } 2189 return (ZIO_PIPELINE_CONTINUE); 2190 } 2191 2192 zio_nowait(zio_read(zio, zio->io_spa, bp, 2193 zio->io_data, zio->io_size, NULL, NULL, zio->io_priority, 2194 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark)); 2195 2196 return (ZIO_PIPELINE_CONTINUE); 2197} 2198 2199static int 2200zio_ddt_read_done(zio_t *zio) 2201{ 2202 blkptr_t *bp = zio->io_bp; 2203 2204 if (zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE)) 2205 return (ZIO_PIPELINE_STOP); 2206 2207 ASSERT(BP_GET_DEDUP(bp)); 2208 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 2209 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2210 2211 if (zio->io_child_error[ZIO_CHILD_DDT]) { 2212 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2213 ddt_entry_t *dde = zio->io_vsd; 2214 if (ddt == NULL) { 2215 ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE); 2216 return (ZIO_PIPELINE_CONTINUE); 2217 } 2218 if (dde == NULL) { 2219 zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1; 2220 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 2221 return (ZIO_PIPELINE_STOP); 2222 } 2223 if (dde->dde_repair_data != NULL) { 2224 bcopy(dde->dde_repair_data, zio->io_data, zio->io_size); 2225 zio->io_child_error[ZIO_CHILD_DDT] = 0; 2226 } 2227 ddt_repair_done(ddt, dde); 2228 zio->io_vsd = NULL; 2229 } 2230 2231 ASSERT(zio->io_vsd == NULL); 2232 2233 return (ZIO_PIPELINE_CONTINUE); 2234} 2235 2236static boolean_t 2237zio_ddt_collision(zio_t *zio, ddt_t *ddt, ddt_entry_t *dde) 2238{ 2239 spa_t *spa = zio->io_spa; 2240 2241 /* 2242 * Note: we compare the original data, not the transformed data, 2243 * because when zio->io_bp is an override bp, we will not have 2244 * pushed the I/O transforms. That's an important optimization 2245 * because otherwise we'd compress/encrypt all dmu_sync() data twice. 2246 */ 2247 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 2248 zio_t *lio = dde->dde_lead_zio[p]; 2249 2250 if (lio != NULL) { 2251 return (lio->io_orig_size != zio->io_orig_size || 2252 bcmp(zio->io_orig_data, lio->io_orig_data, 2253 zio->io_orig_size) != 0); 2254 } 2255 } 2256 2257 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 2258 ddt_phys_t *ddp = &dde->dde_phys[p]; 2259 2260 if (ddp->ddp_phys_birth != 0) { 2261 arc_buf_t *abuf = NULL; 2262 arc_flags_t aflags = ARC_FLAG_WAIT; 2263 blkptr_t blk = *zio->io_bp; 2264 int error; 2265 2266 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth); 2267 2268 ddt_exit(ddt); 2269 2270 error = arc_read(NULL, spa, &blk, 2271 arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ, 2272 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, 2273 &aflags, &zio->io_bookmark); 2274 2275 if (error == 0) { 2276 if (arc_buf_size(abuf) != zio->io_orig_size || 2277 bcmp(abuf->b_data, zio->io_orig_data, 2278 zio->io_orig_size) != 0) 2279 error = SET_ERROR(EEXIST); 2280 VERIFY(arc_buf_remove_ref(abuf, &abuf)); 2281 } 2282 2283 ddt_enter(ddt); 2284 return (error != 0); 2285 } 2286 } 2287 2288 return (B_FALSE); 2289} 2290 2291static void 2292zio_ddt_child_write_ready(zio_t *zio) 2293{ 2294 int p = zio->io_prop.zp_copies; 2295 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 2296 ddt_entry_t *dde = zio->io_private; 2297 ddt_phys_t *ddp = &dde->dde_phys[p]; 2298 zio_t *pio; 2299 2300 if (zio->io_error) 2301 return; 2302 2303 ddt_enter(ddt); 2304 2305 ASSERT(dde->dde_lead_zio[p] == zio); 2306 2307 ddt_phys_fill(ddp, zio->io_bp); 2308 2309 while ((pio = zio_walk_parents(zio)) != NULL) 2310 ddt_bp_fill(ddp, pio->io_bp, zio->io_txg); 2311 2312 ddt_exit(ddt); 2313} 2314 2315static void 2316zio_ddt_child_write_done(zio_t *zio) 2317{ 2318 int p = zio->io_prop.zp_copies; 2319 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 2320 ddt_entry_t *dde = zio->io_private; 2321 ddt_phys_t *ddp = &dde->dde_phys[p]; 2322 2323 ddt_enter(ddt); 2324 2325 ASSERT(ddp->ddp_refcnt == 0); 2326 ASSERT(dde->dde_lead_zio[p] == zio); 2327 dde->dde_lead_zio[p] = NULL; 2328 2329 if (zio->io_error == 0) { 2330 while (zio_walk_parents(zio) != NULL) 2331 ddt_phys_addref(ddp); 2332 } else { 2333 ddt_phys_clear(ddp); 2334 } 2335 2336 ddt_exit(ddt); 2337} 2338 2339static void 2340zio_ddt_ditto_write_done(zio_t *zio) 2341{ 2342 int p = DDT_PHYS_DITTO; 2343 zio_prop_t *zp = &zio->io_prop; 2344 blkptr_t *bp = zio->io_bp; 2345 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2346 ddt_entry_t *dde = zio->io_private; 2347 ddt_phys_t *ddp = &dde->dde_phys[p]; 2348 ddt_key_t *ddk = &dde->dde_key; 2349 2350 ddt_enter(ddt); 2351 2352 ASSERT(ddp->ddp_refcnt == 0); 2353 ASSERT(dde->dde_lead_zio[p] == zio); 2354 dde->dde_lead_zio[p] = NULL; 2355 2356 if (zio->io_error == 0) { 2357 ASSERT(ZIO_CHECKSUM_EQUAL(bp->blk_cksum, ddk->ddk_cksum)); 2358 ASSERT(zp->zp_copies < SPA_DVAS_PER_BP); 2359 ASSERT(zp->zp_copies == BP_GET_NDVAS(bp) - BP_IS_GANG(bp)); 2360 if (ddp->ddp_phys_birth != 0) 2361 ddt_phys_free(ddt, ddk, ddp, zio->io_txg); 2362 ddt_phys_fill(ddp, bp); 2363 } 2364 2365 ddt_exit(ddt); 2366} 2367 2368static int 2369zio_ddt_write(zio_t *zio) 2370{ 2371 spa_t *spa = zio->io_spa; 2372 blkptr_t *bp = zio->io_bp; 2373 uint64_t txg = zio->io_txg; 2374 zio_prop_t *zp = &zio->io_prop; 2375 int p = zp->zp_copies; 2376 int ditto_copies; 2377 zio_t *cio = NULL; 2378 zio_t *dio = NULL; 2379 ddt_t *ddt = ddt_select(spa, bp); 2380 ddt_entry_t *dde; 2381 ddt_phys_t *ddp; 2382 2383 ASSERT(BP_GET_DEDUP(bp)); 2384 ASSERT(BP_GET_CHECKSUM(bp) == zp->zp_checksum); 2385 ASSERT(BP_IS_HOLE(bp) || zio->io_bp_override); 2386 2387 ddt_enter(ddt); 2388 dde = ddt_lookup(ddt, bp, B_TRUE); 2389 ddp = &dde->dde_phys[p]; 2390 2391 if (zp->zp_dedup_verify && zio_ddt_collision(zio, ddt, dde)) { 2392 /* 2393 * If we're using a weak checksum, upgrade to a strong checksum 2394 * and try again. If we're already using a strong checksum, 2395 * we can't resolve it, so just convert to an ordinary write. 2396 * (And automatically e-mail a paper to Nature?) 2397 */ 2398 if (!zio_checksum_table[zp->zp_checksum].ci_dedup) { 2399 zp->zp_checksum = spa_dedup_checksum(spa); 2400 zio_pop_transforms(zio); 2401 zio->io_stage = ZIO_STAGE_OPEN; 2402 BP_ZERO(bp); 2403 } else { 2404 zp->zp_dedup = B_FALSE; 2405 } 2406 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2407 ddt_exit(ddt); 2408 return (ZIO_PIPELINE_CONTINUE); 2409 } 2410 2411 ditto_copies = ddt_ditto_copies_needed(ddt, dde, ddp); 2412 ASSERT(ditto_copies < SPA_DVAS_PER_BP); 2413 2414 if (ditto_copies > ddt_ditto_copies_present(dde) && 2415 dde->dde_lead_zio[DDT_PHYS_DITTO] == NULL) { 2416 zio_prop_t czp = *zp; 2417 2418 czp.zp_copies = ditto_copies; 2419 2420 /* 2421 * If we arrived here with an override bp, we won't have run 2422 * the transform stack, so we won't have the data we need to 2423 * generate a child i/o. So, toss the override bp and restart. 2424 * This is safe, because using the override bp is just an 2425 * optimization; and it's rare, so the cost doesn't matter. 2426 */ 2427 if (zio->io_bp_override) { 2428 zio_pop_transforms(zio); 2429 zio->io_stage = ZIO_STAGE_OPEN; 2430 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2431 zio->io_bp_override = NULL; 2432 BP_ZERO(bp); 2433 ddt_exit(ddt); 2434 return (ZIO_PIPELINE_CONTINUE); 2435 } 2436 2437 dio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2438 zio->io_orig_size, &czp, NULL, NULL, 2439 zio_ddt_ditto_write_done, dde, zio->io_priority, 2440 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2441 2442 zio_push_transform(dio, zio->io_data, zio->io_size, 0, NULL); 2443 dde->dde_lead_zio[DDT_PHYS_DITTO] = dio; 2444 } 2445 2446 if (ddp->ddp_phys_birth != 0 || dde->dde_lead_zio[p] != NULL) { 2447 if (ddp->ddp_phys_birth != 0) 2448 ddt_bp_fill(ddp, bp, txg); 2449 if (dde->dde_lead_zio[p] != NULL) 2450 zio_add_child(zio, dde->dde_lead_zio[p]); 2451 else 2452 ddt_phys_addref(ddp); 2453 } else if (zio->io_bp_override) { 2454 ASSERT(bp->blk_birth == txg); 2455 ASSERT(BP_EQUAL(bp, zio->io_bp_override)); 2456 ddt_phys_fill(ddp, bp); 2457 ddt_phys_addref(ddp); 2458 } else { 2459 cio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2460 zio->io_orig_size, zp, zio_ddt_child_write_ready, NULL, 2461 zio_ddt_child_write_done, dde, zio->io_priority, 2462 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2463 2464 zio_push_transform(cio, zio->io_data, zio->io_size, 0, NULL); 2465 dde->dde_lead_zio[p] = cio; 2466 } 2467 2468 ddt_exit(ddt); 2469 2470 if (cio) 2471 zio_nowait(cio); 2472 if (dio) 2473 zio_nowait(dio); 2474 2475 return (ZIO_PIPELINE_CONTINUE); 2476} 2477 2478ddt_entry_t *freedde; /* for debugging */ 2479 2480static int 2481zio_ddt_free(zio_t *zio) 2482{ 2483 spa_t *spa = zio->io_spa; 2484 blkptr_t *bp = zio->io_bp; 2485 ddt_t *ddt = ddt_select(spa, bp); 2486 ddt_entry_t *dde; 2487 ddt_phys_t *ddp; 2488 2489 ASSERT(BP_GET_DEDUP(bp)); 2490 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2491 2492 ddt_enter(ddt); 2493 freedde = dde = ddt_lookup(ddt, bp, B_TRUE); 2494 ddp = ddt_phys_select(dde, bp); 2495 ddt_phys_decref(ddp); 2496 ddt_exit(ddt); 2497 2498 return (ZIO_PIPELINE_CONTINUE); 2499} 2500 2501/* 2502 * ========================================================================== 2503 * Allocate and free blocks 2504 * ========================================================================== 2505 */ 2506static int 2507zio_dva_allocate(zio_t *zio) 2508{ 2509 spa_t *spa = zio->io_spa; 2510 metaslab_class_t *mc = spa_normal_class(spa); 2511 blkptr_t *bp = zio->io_bp; 2512 int error; 2513 int flags = 0; 2514 2515 if (zio->io_gang_leader == NULL) { 2516 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2517 zio->io_gang_leader = zio; 2518 } 2519 2520 ASSERT(BP_IS_HOLE(bp)); 2521 ASSERT0(BP_GET_NDVAS(bp)); 2522 ASSERT3U(zio->io_prop.zp_copies, >, 0); 2523 ASSERT3U(zio->io_prop.zp_copies, <=, spa_max_replication(spa)); 2524 ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp)); 2525 2526 /* 2527 * The dump device does not support gang blocks so allocation on 2528 * behalf of the dump device (i.e. ZIO_FLAG_NODATA) must avoid 2529 * the "fast" gang feature. 2530 */ 2531 flags |= (zio->io_flags & ZIO_FLAG_NODATA) ? METASLAB_GANG_AVOID : 0; 2532 flags |= (zio->io_flags & ZIO_FLAG_GANG_CHILD) ? 2533 METASLAB_GANG_CHILD : 0; 2534 error = metaslab_alloc(spa, mc, zio->io_size, bp, 2535 zio->io_prop.zp_copies, zio->io_txg, NULL, flags); 2536 2537 if (error) { 2538 spa_dbgmsg(spa, "%s: metaslab allocation failure: zio %p, " 2539 "size %llu, error %d", spa_name(spa), zio, zio->io_size, 2540 error); 2541 if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE) 2542 return (zio_write_gang_block(zio)); 2543 zio->io_error = error; 2544 } 2545 2546 return (ZIO_PIPELINE_CONTINUE); 2547} 2548 2549static int 2550zio_dva_free(zio_t *zio) 2551{ 2552 metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE); 2553 2554 return (ZIO_PIPELINE_CONTINUE); 2555} 2556 2557static int 2558zio_dva_claim(zio_t *zio) 2559{ 2560 int error; 2561 2562 error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg); 2563 if (error) 2564 zio->io_error = error; 2565 2566 return (ZIO_PIPELINE_CONTINUE); 2567} 2568 2569/* 2570 * Undo an allocation. This is used by zio_done() when an I/O fails 2571 * and we want to give back the block we just allocated. 2572 * This handles both normal blocks and gang blocks. 2573 */ 2574static void 2575zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp) 2576{ 2577 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp)); 2578 ASSERT(zio->io_bp_override == NULL); 2579 2580 if (!BP_IS_HOLE(bp)) 2581 metaslab_free(zio->io_spa, bp, bp->blk_birth, B_TRUE); 2582 2583 if (gn != NULL) { 2584 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 2585 zio_dva_unallocate(zio, gn->gn_child[g], 2586 &gn->gn_gbh->zg_blkptr[g]); 2587 } 2588 } 2589} 2590 2591/* 2592 * Try to allocate an intent log block. Return 0 on success, errno on failure. 2593 */ 2594int 2595zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp, blkptr_t *old_bp, 2596 uint64_t size, boolean_t use_slog) 2597{ 2598 int error = 1; 2599 2600 ASSERT(txg > spa_syncing_txg(spa)); 2601 2602 /* 2603 * ZIL blocks are always contiguous (i.e. not gang blocks) so we 2604 * set the METASLAB_GANG_AVOID flag so that they don't "fast gang" 2605 * when allocating them. 2606 */ 2607 if (use_slog) { 2608 error = metaslab_alloc(spa, spa_log_class(spa), size, 2609 new_bp, 1, txg, old_bp, 2610 METASLAB_HINTBP_AVOID | METASLAB_GANG_AVOID); 2611 } 2612 2613 if (error) { 2614 error = metaslab_alloc(spa, spa_normal_class(spa), size, 2615 new_bp, 1, txg, old_bp, 2616 METASLAB_HINTBP_AVOID); 2617 } 2618 2619 if (error == 0) { 2620 BP_SET_LSIZE(new_bp, size); 2621 BP_SET_PSIZE(new_bp, size); 2622 BP_SET_COMPRESS(new_bp, ZIO_COMPRESS_OFF); 2623 BP_SET_CHECKSUM(new_bp, 2624 spa_version(spa) >= SPA_VERSION_SLIM_ZIL 2625 ? ZIO_CHECKSUM_ZILOG2 : ZIO_CHECKSUM_ZILOG); 2626 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG); 2627 BP_SET_LEVEL(new_bp, 0); 2628 BP_SET_DEDUP(new_bp, 0); 2629 BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER); 2630 } 2631 2632 return (error); 2633} 2634 2635/* 2636 * Free an intent log block. 2637 */ 2638void 2639zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp) 2640{ 2641 ASSERT(BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG); 2642 ASSERT(!BP_IS_GANG(bp)); 2643 2644 zio_free(spa, txg, bp); 2645} 2646 2647/* 2648 * ========================================================================== 2649 * Read, write and delete to physical devices 2650 * ========================================================================== 2651 */ 2652static int 2653zio_vdev_io_start(zio_t *zio) 2654{ 2655 vdev_t *vd = zio->io_vd; 2656 uint64_t align; 2657 spa_t *spa = zio->io_spa; 2658 int ret; 2659 2660 ASSERT(zio->io_error == 0); 2661 ASSERT(zio->io_child_error[ZIO_CHILD_VDEV] == 0); 2662 2663 if (vd == NULL) { 2664 if (!(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 2665 spa_config_enter(spa, SCL_ZIO, zio, RW_READER); 2666 2667 /* 2668 * The mirror_ops handle multiple DVAs in a single BP. 2669 */ 2670 return (vdev_mirror_ops.vdev_op_io_start(zio)); 2671 } 2672 2673 if (vd->vdev_ops->vdev_op_leaf && zio->io_type == ZIO_TYPE_FREE && 2674 zio->io_priority == ZIO_PRIORITY_NOW) { 2675 trim_map_free(vd, zio->io_offset, zio->io_size, zio->io_txg); 2676 return (ZIO_PIPELINE_CONTINUE); 2677 } 2678 2679 /* 2680 * We keep track of time-sensitive I/Os so that the scan thread 2681 * can quickly react to certain workloads. In particular, we care 2682 * about non-scrubbing, top-level reads and writes with the following 2683 * characteristics: 2684 * - synchronous writes of user data to non-slog devices 2685 * - any reads of user data 2686 * When these conditions are met, adjust the timestamp of spa_last_io 2687 * which allows the scan thread to adjust its workload accordingly. 2688 */ 2689 if (!(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && zio->io_bp != NULL && 2690 vd == vd->vdev_top && !vd->vdev_islog && 2691 zio->io_bookmark.zb_objset != DMU_META_OBJSET && 2692 zio->io_txg != spa_syncing_txg(spa)) { 2693 uint64_t old = spa->spa_last_io; 2694 uint64_t new = ddi_get_lbolt64(); 2695 if (old != new) 2696 (void) atomic_cas_64(&spa->spa_last_io, old, new); 2697 } 2698 2699 align = 1ULL << vd->vdev_top->vdev_ashift; 2700 2701 if ((!(zio->io_flags & ZIO_FLAG_PHYSICAL) || 2702 (vd->vdev_top->vdev_physical_ashift > SPA_MINBLOCKSHIFT)) && 2703 P2PHASE(zio->io_size, align) != 0) { 2704 /* Transform logical writes to be a full physical block size. */ 2705 uint64_t asize = P2ROUNDUP(zio->io_size, align); 2706 char *abuf = NULL; 2707 if (zio->io_type == ZIO_TYPE_READ || 2708 zio->io_type == ZIO_TYPE_WRITE) 2709 abuf = zio_buf_alloc(asize); 2710 ASSERT(vd == vd->vdev_top); 2711 if (zio->io_type == ZIO_TYPE_WRITE) { 2712 bcopy(zio->io_data, abuf, zio->io_size); 2713 bzero(abuf + zio->io_size, asize - zio->io_size); 2714 } 2715 zio_push_transform(zio, abuf, asize, abuf ? asize : 0, 2716 zio_subblock); 2717 } 2718 2719 /* 2720 * If this is not a physical io, make sure that it is properly aligned 2721 * before proceeding. 2722 */ 2723 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL)) { 2724 ASSERT0(P2PHASE(zio->io_offset, align)); 2725 ASSERT0(P2PHASE(zio->io_size, align)); 2726 } else { 2727 /* 2728 * For physical writes, we allow 512b aligned writes and assume 2729 * the device will perform a read-modify-write as necessary. 2730 */ 2731 ASSERT0(P2PHASE(zio->io_offset, SPA_MINBLOCKSIZE)); 2732 ASSERT0(P2PHASE(zio->io_size, SPA_MINBLOCKSIZE)); 2733 } 2734 2735 VERIFY(zio->io_type == ZIO_TYPE_READ || spa_writeable(spa)); 2736 2737 /* 2738 * If this is a repair I/O, and there's no self-healing involved -- 2739 * that is, we're just resilvering what we expect to resilver -- 2740 * then don't do the I/O unless zio's txg is actually in vd's DTL. 2741 * This prevents spurious resilvering with nested replication. 2742 * For example, given a mirror of mirrors, (A+B)+(C+D), if only 2743 * A is out of date, we'll read from C+D, then use the data to 2744 * resilver A+B -- but we don't actually want to resilver B, just A. 2745 * The top-level mirror has no way to know this, so instead we just 2746 * discard unnecessary repairs as we work our way down the vdev tree. 2747 * The same logic applies to any form of nested replication: 2748 * ditto + mirror, RAID-Z + replacing, etc. This covers them all. 2749 */ 2750 if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) && 2751 !(zio->io_flags & ZIO_FLAG_SELF_HEAL) && 2752 zio->io_txg != 0 && /* not a delegated i/o */ 2753 !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) { 2754 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 2755 zio_vdev_io_bypass(zio); 2756 return (ZIO_PIPELINE_CONTINUE); 2757 } 2758 2759 if (vd->vdev_ops->vdev_op_leaf) { 2760 switch (zio->io_type) { 2761 case ZIO_TYPE_READ: 2762 if (vdev_cache_read(zio)) 2763 return (ZIO_PIPELINE_CONTINUE); 2764 /* FALLTHROUGH */ 2765 case ZIO_TYPE_WRITE: 2766 case ZIO_TYPE_FREE: 2767 if ((zio = vdev_queue_io(zio)) == NULL) 2768 return (ZIO_PIPELINE_STOP); 2769 2770 if (!vdev_accessible(vd, zio)) { 2771 zio->io_error = SET_ERROR(ENXIO); 2772 zio_interrupt(zio); 2773 return (ZIO_PIPELINE_STOP); 2774 } 2775 break; 2776 } 2777 /* 2778 * Note that we ignore repair writes for TRIM because they can 2779 * conflict with normal writes. This isn't an issue because, by 2780 * definition, we only repair blocks that aren't freed. 2781 */ 2782 if (zio->io_type == ZIO_TYPE_WRITE && 2783 !(zio->io_flags & ZIO_FLAG_IO_REPAIR) && 2784 !trim_map_write_start(zio)) 2785 return (ZIO_PIPELINE_STOP); 2786 } 2787 2788 ret = vd->vdev_ops->vdev_op_io_start(zio); 2789 ASSERT(ret == ZIO_PIPELINE_STOP); 2790 2791 return (ret); 2792} 2793 2794static int 2795zio_vdev_io_done(zio_t *zio) 2796{ 2797 vdev_t *vd = zio->io_vd; 2798 vdev_ops_t *ops = vd ? vd->vdev_ops : &vdev_mirror_ops; 2799 boolean_t unexpected_error = B_FALSE; 2800 2801 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 2802 return (ZIO_PIPELINE_STOP); 2803 2804 ASSERT(zio->io_type == ZIO_TYPE_READ || 2805 zio->io_type == ZIO_TYPE_WRITE || zio->io_type == ZIO_TYPE_FREE); 2806 2807 if (vd != NULL && vd->vdev_ops->vdev_op_leaf && 2808 (zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE || 2809 zio->io_type == ZIO_TYPE_FREE)) { 2810 2811 if (zio->io_type == ZIO_TYPE_WRITE && 2812 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) 2813 trim_map_write_done(zio); 2814 2815 vdev_queue_io_done(zio); 2816 2817 if (zio->io_type == ZIO_TYPE_WRITE) 2818 vdev_cache_write(zio); 2819 2820 if (zio_injection_enabled && zio->io_error == 0) 2821 zio->io_error = zio_handle_device_injection(vd, 2822 zio, EIO); 2823 2824 if (zio_injection_enabled && zio->io_error == 0) 2825 zio->io_error = zio_handle_label_injection(zio, EIO); 2826 2827 if (zio->io_error) { 2828 if (zio->io_error == ENOTSUP && 2829 zio->io_type == ZIO_TYPE_FREE) { 2830 /* Not all devices support TRIM. */ 2831 } else if (!vdev_accessible(vd, zio)) { 2832 zio->io_error = SET_ERROR(ENXIO); 2833 } else { 2834 unexpected_error = B_TRUE; 2835 } 2836 } 2837 } 2838 2839 ops->vdev_op_io_done(zio); 2840 2841 if (unexpected_error) 2842 VERIFY(vdev_probe(vd, zio) == NULL); 2843 2844 return (ZIO_PIPELINE_CONTINUE); 2845} 2846 2847/* 2848 * For non-raidz ZIOs, we can just copy aside the bad data read from the 2849 * disk, and use that to finish the checksum ereport later. 2850 */ 2851static void 2852zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr, 2853 const void *good_buf) 2854{ 2855 /* no processing needed */ 2856 zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE); 2857} 2858 2859/*ARGSUSED*/ 2860void 2861zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *ignored) 2862{ 2863 void *buf = zio_buf_alloc(zio->io_size); 2864 2865 bcopy(zio->io_data, buf, zio->io_size); 2866 2867 zcr->zcr_cbinfo = zio->io_size; 2868 zcr->zcr_cbdata = buf; 2869 zcr->zcr_finish = zio_vsd_default_cksum_finish; 2870 zcr->zcr_free = zio_buf_free; 2871} 2872 2873static int 2874zio_vdev_io_assess(zio_t *zio) 2875{ 2876 vdev_t *vd = zio->io_vd; 2877 2878 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 2879 return (ZIO_PIPELINE_STOP); 2880 2881 if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 2882 spa_config_exit(zio->io_spa, SCL_ZIO, zio); 2883 2884 if (zio->io_vsd != NULL) { 2885 zio->io_vsd_ops->vsd_free(zio); 2886 zio->io_vsd = NULL; 2887 } 2888 2889 if (zio_injection_enabled && zio->io_error == 0) 2890 zio->io_error = zio_handle_fault_injection(zio, EIO); 2891 2892 if (zio->io_type == ZIO_TYPE_FREE && 2893 zio->io_priority != ZIO_PRIORITY_NOW) { 2894 switch (zio->io_error) { 2895 case 0: 2896 ZIO_TRIM_STAT_INCR(bytes, zio->io_size); 2897 ZIO_TRIM_STAT_BUMP(success); 2898 break; 2899 case EOPNOTSUPP: 2900 ZIO_TRIM_STAT_BUMP(unsupported); 2901 break; 2902 default: 2903 ZIO_TRIM_STAT_BUMP(failed); 2904 break; 2905 } 2906 } 2907 2908 /* 2909 * If the I/O failed, determine whether we should attempt to retry it. 2910 * 2911 * On retry, we cut in line in the issue queue, since we don't want 2912 * compression/checksumming/etc. work to prevent our (cheap) IO reissue. 2913 */ 2914 if (zio->io_error && vd == NULL && 2915 !(zio->io_flags & (ZIO_FLAG_DONT_RETRY | ZIO_FLAG_IO_RETRY))) { 2916 ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_QUEUE)); /* not a leaf */ 2917 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_BYPASS)); /* not a leaf */ 2918 zio->io_error = 0; 2919 zio->io_flags |= ZIO_FLAG_IO_RETRY | 2920 ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE; 2921 zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1; 2922 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, 2923 zio_requeue_io_start_cut_in_line); 2924 return (ZIO_PIPELINE_STOP); 2925 } 2926 2927 /* 2928 * If we got an error on a leaf device, convert it to ENXIO 2929 * if the device is not accessible at all. 2930 */ 2931 if (zio->io_error && vd != NULL && vd->vdev_ops->vdev_op_leaf && 2932 !vdev_accessible(vd, zio)) 2933 zio->io_error = SET_ERROR(ENXIO); 2934 2935 /* 2936 * If we can't write to an interior vdev (mirror or RAID-Z), 2937 * set vdev_cant_write so that we stop trying to allocate from it. 2938 */ 2939 if (zio->io_error == ENXIO && zio->io_type == ZIO_TYPE_WRITE && 2940 vd != NULL && !vd->vdev_ops->vdev_op_leaf) { 2941 vd->vdev_cant_write = B_TRUE; 2942 } 2943 2944 if (zio->io_error) 2945 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2946 2947 if (vd != NULL && vd->vdev_ops->vdev_op_leaf && 2948 zio->io_physdone != NULL) { 2949 ASSERT(!(zio->io_flags & ZIO_FLAG_DELEGATED)); 2950 ASSERT(zio->io_child_type == ZIO_CHILD_VDEV); 2951 zio->io_physdone(zio->io_logical); 2952 } 2953 2954 return (ZIO_PIPELINE_CONTINUE); 2955} 2956 2957void 2958zio_vdev_io_reissue(zio_t *zio) 2959{ 2960 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 2961 ASSERT(zio->io_error == 0); 2962 2963 zio->io_stage >>= 1; 2964} 2965 2966void 2967zio_vdev_io_redone(zio_t *zio) 2968{ 2969 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE); 2970 2971 zio->io_stage >>= 1; 2972} 2973 2974void 2975zio_vdev_io_bypass(zio_t *zio) 2976{ 2977 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 2978 ASSERT(zio->io_error == 0); 2979 2980 zio->io_flags |= ZIO_FLAG_IO_BYPASS; 2981 zio->io_stage = ZIO_STAGE_VDEV_IO_ASSESS >> 1; 2982} 2983 2984/* 2985 * ========================================================================== 2986 * Generate and verify checksums 2987 * ========================================================================== 2988 */ 2989static int 2990zio_checksum_generate(zio_t *zio) 2991{ 2992 blkptr_t *bp = zio->io_bp; 2993 enum zio_checksum checksum; 2994 2995 if (bp == NULL) { 2996 /* 2997 * This is zio_write_phys(). 2998 * We're either generating a label checksum, or none at all. 2999 */ 3000 checksum = zio->io_prop.zp_checksum; 3001 3002 if (checksum == ZIO_CHECKSUM_OFF) 3003 return (ZIO_PIPELINE_CONTINUE); 3004 3005 ASSERT(checksum == ZIO_CHECKSUM_LABEL); 3006 } else { 3007 if (BP_IS_GANG(bp) && zio->io_child_type == ZIO_CHILD_GANG) { 3008 ASSERT(!IO_IS_ALLOCATING(zio)); 3009 checksum = ZIO_CHECKSUM_GANG_HEADER; 3010 } else { 3011 checksum = BP_GET_CHECKSUM(bp); 3012 } 3013 } 3014 3015 zio_checksum_compute(zio, checksum, zio->io_data, zio->io_size); 3016 3017 return (ZIO_PIPELINE_CONTINUE); 3018} 3019 3020static int 3021zio_checksum_verify(zio_t *zio) 3022{ 3023 zio_bad_cksum_t info; 3024 blkptr_t *bp = zio->io_bp; 3025 int error; 3026 3027 ASSERT(zio->io_vd != NULL); 3028 3029 if (bp == NULL) { 3030 /* 3031 * This is zio_read_phys(). 3032 * We're either verifying a label checksum, or nothing at all. 3033 */ 3034 if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF) 3035 return (ZIO_PIPELINE_CONTINUE); 3036 3037 ASSERT(zio->io_prop.zp_checksum == ZIO_CHECKSUM_LABEL); 3038 } 3039 3040 if ((error = zio_checksum_error(zio, &info)) != 0) { 3041 zio->io_error = error; 3042 if (error == ECKSUM && 3043 !(zio->io_flags & ZIO_FLAG_SPECULATIVE)) { 3044 zfs_ereport_start_checksum(zio->io_spa, 3045 zio->io_vd, zio, zio->io_offset, 3046 zio->io_size, NULL, &info); 3047 } 3048 } 3049 3050 return (ZIO_PIPELINE_CONTINUE); 3051} 3052 3053/* 3054 * Called by RAID-Z to ensure we don't compute the checksum twice. 3055 */ 3056void 3057zio_checksum_verified(zio_t *zio) 3058{ 3059 zio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 3060} 3061 3062/* 3063 * ========================================================================== 3064 * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other. 3065 * An error of 0 indicates success. ENXIO indicates whole-device failure, 3066 * which may be transient (e.g. unplugged) or permament. ECKSUM and EIO 3067 * indicate errors that are specific to one I/O, and most likely permanent. 3068 * Any other error is presumed to be worse because we weren't expecting it. 3069 * ========================================================================== 3070 */ 3071int 3072zio_worst_error(int e1, int e2) 3073{ 3074 static int zio_error_rank[] = { 0, ENXIO, ECKSUM, EIO }; 3075 int r1, r2; 3076 3077 for (r1 = 0; r1 < sizeof (zio_error_rank) / sizeof (int); r1++) 3078 if (e1 == zio_error_rank[r1]) 3079 break; 3080 3081 for (r2 = 0; r2 < sizeof (zio_error_rank) / sizeof (int); r2++) 3082 if (e2 == zio_error_rank[r2]) 3083 break; 3084 3085 return (r1 > r2 ? e1 : e2); 3086} 3087 3088/* 3089 * ========================================================================== 3090 * I/O completion 3091 * ========================================================================== 3092 */ 3093static int 3094zio_ready(zio_t *zio) 3095{ 3096 blkptr_t *bp = zio->io_bp; 3097 zio_t *pio, *pio_next; 3098 3099 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 3100 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_READY)) 3101 return (ZIO_PIPELINE_STOP); 3102 3103 if (zio->io_ready) { 3104 ASSERT(IO_IS_ALLOCATING(zio)); 3105 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp) || 3106 (zio->io_flags & ZIO_FLAG_NOPWRITE)); 3107 ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0); 3108 3109 zio->io_ready(zio); 3110 } 3111 3112 if (bp != NULL && bp != &zio->io_bp_copy) 3113 zio->io_bp_copy = *bp; 3114 3115 if (zio->io_error) 3116 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 3117 3118 mutex_enter(&zio->io_lock); 3119 zio->io_state[ZIO_WAIT_READY] = 1; 3120 pio = zio_walk_parents(zio); 3121 mutex_exit(&zio->io_lock); 3122 3123 /* 3124 * As we notify zio's parents, new parents could be added. 3125 * New parents go to the head of zio's io_parent_list, however, 3126 * so we will (correctly) not notify them. The remainder of zio's 3127 * io_parent_list, from 'pio_next' onward, cannot change because 3128 * all parents must wait for us to be done before they can be done. 3129 */ 3130 for (; pio != NULL; pio = pio_next) { 3131 pio_next = zio_walk_parents(zio); 3132 zio_notify_parent(pio, zio, ZIO_WAIT_READY); 3133 } 3134 3135 if (zio->io_flags & ZIO_FLAG_NODATA) { 3136 if (BP_IS_GANG(bp)) { 3137 zio->io_flags &= ~ZIO_FLAG_NODATA; 3138 } else { 3139 ASSERT((uintptr_t)zio->io_data < SPA_MAXBLOCKSIZE); 3140 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 3141 } 3142 } 3143 3144 if (zio_injection_enabled && 3145 zio->io_spa->spa_syncing_txg == zio->io_txg) 3146 zio_handle_ignored_writes(zio); 3147 3148 return (ZIO_PIPELINE_CONTINUE); 3149} 3150 3151static int 3152zio_done(zio_t *zio) 3153{ 3154 spa_t *spa = zio->io_spa; 3155 zio_t *lio = zio->io_logical; 3156 blkptr_t *bp = zio->io_bp; 3157 vdev_t *vd = zio->io_vd; 3158 uint64_t psize = zio->io_size; 3159 zio_t *pio, *pio_next; 3160 3161 /* 3162 * If our children haven't all completed, 3163 * wait for them and then repeat this pipeline stage. 3164 */ 3165 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE) || 3166 zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE) || 3167 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE) || 3168 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_DONE)) 3169 return (ZIO_PIPELINE_STOP); 3170 3171 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 3172 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 3173 ASSERT(zio->io_children[c][w] == 0); 3174 3175 if (bp != NULL && !BP_IS_EMBEDDED(bp)) { 3176 ASSERT(bp->blk_pad[0] == 0); 3177 ASSERT(bp->blk_pad[1] == 0); 3178 ASSERT(bcmp(bp, &zio->io_bp_copy, sizeof (blkptr_t)) == 0 || 3179 (bp == zio_unique_parent(zio)->io_bp)); 3180 if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(bp) && 3181 zio->io_bp_override == NULL && 3182 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) { 3183 ASSERT(!BP_SHOULD_BYTESWAP(bp)); 3184 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(bp)); 3185 ASSERT(BP_COUNT_GANG(bp) == 0 || 3186 (BP_COUNT_GANG(bp) == BP_GET_NDVAS(bp))); 3187 } 3188 if (zio->io_flags & ZIO_FLAG_NOPWRITE) 3189 VERIFY(BP_EQUAL(bp, &zio->io_bp_orig)); 3190 } 3191 3192 /* 3193 * If there were child vdev/gang/ddt errors, they apply to us now. 3194 */ 3195 zio_inherit_child_errors(zio, ZIO_CHILD_VDEV); 3196 zio_inherit_child_errors(zio, ZIO_CHILD_GANG); 3197 zio_inherit_child_errors(zio, ZIO_CHILD_DDT); 3198 3199 /* 3200 * If the I/O on the transformed data was successful, generate any 3201 * checksum reports now while we still have the transformed data. 3202 */ 3203 if (zio->io_error == 0) { 3204 while (zio->io_cksum_report != NULL) { 3205 zio_cksum_report_t *zcr = zio->io_cksum_report; 3206 uint64_t align = zcr->zcr_align; 3207 uint64_t asize = P2ROUNDUP(psize, align); 3208 char *abuf = zio->io_data; 3209 3210 if (asize != psize) { 3211 abuf = zio_buf_alloc(asize); 3212 bcopy(zio->io_data, abuf, psize); 3213 bzero(abuf + psize, asize - psize); 3214 } 3215 3216 zio->io_cksum_report = zcr->zcr_next; 3217 zcr->zcr_next = NULL; 3218 zcr->zcr_finish(zcr, abuf); 3219 zfs_ereport_free_checksum(zcr); 3220 3221 if (asize != psize) 3222 zio_buf_free(abuf, asize); 3223 } 3224 } 3225 3226 zio_pop_transforms(zio); /* note: may set zio->io_error */ 3227 3228 vdev_stat_update(zio, psize); 3229 3230 if (zio->io_error) { 3231 /* 3232 * If this I/O is attached to a particular vdev, 3233 * generate an error message describing the I/O failure 3234 * at the block level. We ignore these errors if the 3235 * device is currently unavailable. 3236 */ 3237 if (zio->io_error != ECKSUM && vd != NULL && !vdev_is_dead(vd)) 3238 zfs_ereport_post(FM_EREPORT_ZFS_IO, spa, vd, zio, 0, 0); 3239 3240 if ((zio->io_error == EIO || !(zio->io_flags & 3241 (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) && 3242 zio == lio) { 3243 /* 3244 * For logical I/O requests, tell the SPA to log the 3245 * error and generate a logical data ereport. 3246 */ 3247 spa_log_error(spa, zio); 3248 zfs_ereport_post(FM_EREPORT_ZFS_DATA, spa, NULL, zio, 3249 0, 0); 3250 } 3251 } 3252 3253 if (zio->io_error && zio == lio) { 3254 /* 3255 * Determine whether zio should be reexecuted. This will 3256 * propagate all the way to the root via zio_notify_parent(). 3257 */ 3258 ASSERT(vd == NULL && bp != NULL); 3259 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3260 3261 if (IO_IS_ALLOCATING(zio) && 3262 !(zio->io_flags & ZIO_FLAG_CANFAIL)) { 3263 if (zio->io_error != ENOSPC) 3264 zio->io_reexecute |= ZIO_REEXECUTE_NOW; 3265 else 3266 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3267 } 3268 3269 if ((zio->io_type == ZIO_TYPE_READ || 3270 zio->io_type == ZIO_TYPE_FREE) && 3271 !(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && 3272 zio->io_error == ENXIO && 3273 spa_load_state(spa) == SPA_LOAD_NONE && 3274 spa_get_failmode(spa) != ZIO_FAILURE_MODE_CONTINUE) 3275 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3276 3277 if (!(zio->io_flags & ZIO_FLAG_CANFAIL) && !zio->io_reexecute) 3278 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3279 3280 /* 3281 * Here is a possibly good place to attempt to do 3282 * either combinatorial reconstruction or error correction 3283 * based on checksums. It also might be a good place 3284 * to send out preliminary ereports before we suspend 3285 * processing. 3286 */ 3287 } 3288 3289 /* 3290 * If there were logical child errors, they apply to us now. 3291 * We defer this until now to avoid conflating logical child 3292 * errors with errors that happened to the zio itself when 3293 * updating vdev stats and reporting FMA events above. 3294 */ 3295 zio_inherit_child_errors(zio, ZIO_CHILD_LOGICAL); 3296 3297 if ((zio->io_error || zio->io_reexecute) && 3298 IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio && 3299 !(zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE))) 3300 zio_dva_unallocate(zio, zio->io_gang_tree, bp); 3301 3302 zio_gang_tree_free(&zio->io_gang_tree); 3303 3304 /* 3305 * Godfather I/Os should never suspend. 3306 */ 3307 if ((zio->io_flags & ZIO_FLAG_GODFATHER) && 3308 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) 3309 zio->io_reexecute = 0; 3310 3311 if (zio->io_reexecute) { 3312 /* 3313 * This is a logical I/O that wants to reexecute. 3314 * 3315 * Reexecute is top-down. When an i/o fails, if it's not 3316 * the root, it simply notifies its parent and sticks around. 3317 * The parent, seeing that it still has children in zio_done(), 3318 * does the same. This percolates all the way up to the root. 3319 * The root i/o will reexecute or suspend the entire tree. 3320 * 3321 * This approach ensures that zio_reexecute() honors 3322 * all the original i/o dependency relationships, e.g. 3323 * parents not executing until children are ready. 3324 */ 3325 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3326 3327 zio->io_gang_leader = NULL; 3328 3329 mutex_enter(&zio->io_lock); 3330 zio->io_state[ZIO_WAIT_DONE] = 1; 3331 mutex_exit(&zio->io_lock); 3332 3333 /* 3334 * "The Godfather" I/O monitors its children but is 3335 * not a true parent to them. It will track them through 3336 * the pipeline but severs its ties whenever they get into 3337 * trouble (e.g. suspended). This allows "The Godfather" 3338 * I/O to return status without blocking. 3339 */ 3340 for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) { 3341 zio_link_t *zl = zio->io_walk_link; 3342 pio_next = zio_walk_parents(zio); 3343 3344 if ((pio->io_flags & ZIO_FLAG_GODFATHER) && 3345 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) { 3346 zio_remove_child(pio, zio, zl); 3347 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3348 } 3349 } 3350 3351 if ((pio = zio_unique_parent(zio)) != NULL) { 3352 /* 3353 * We're not a root i/o, so there's nothing to do 3354 * but notify our parent. Don't propagate errors 3355 * upward since we haven't permanently failed yet. 3356 */ 3357 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 3358 zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE; 3359 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3360 } else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) { 3361 /* 3362 * We'd fail again if we reexecuted now, so suspend 3363 * until conditions improve (e.g. device comes online). 3364 */ 3365 zio_suspend(spa, zio); 3366 } else { 3367 /* 3368 * Reexecution is potentially a huge amount of work. 3369 * Hand it off to the otherwise-unused claim taskq. 3370 */ 3371#if defined(illumos) || !defined(_KERNEL) 3372 ASSERT(zio->io_tqent.tqent_next == NULL); 3373#else 3374 ASSERT(zio->io_tqent.tqent_task.ta_pending == 0); 3375#endif 3376 spa_taskq_dispatch_ent(spa, ZIO_TYPE_CLAIM, 3377 ZIO_TASKQ_ISSUE, (task_func_t *)zio_reexecute, zio, 3378 0, &zio->io_tqent); 3379 } 3380 return (ZIO_PIPELINE_STOP); 3381 } 3382 3383 ASSERT(zio->io_child_count == 0); 3384 ASSERT(zio->io_reexecute == 0); 3385 ASSERT(zio->io_error == 0 || (zio->io_flags & ZIO_FLAG_CANFAIL)); 3386 3387 /* 3388 * Report any checksum errors, since the I/O is complete. 3389 */ 3390 while (zio->io_cksum_report != NULL) { 3391 zio_cksum_report_t *zcr = zio->io_cksum_report; 3392 zio->io_cksum_report = zcr->zcr_next; 3393 zcr->zcr_next = NULL; 3394 zcr->zcr_finish(zcr, NULL); 3395 zfs_ereport_free_checksum(zcr); 3396 } 3397 3398 /* 3399 * It is the responsibility of the done callback to ensure that this 3400 * particular zio is no longer discoverable for adoption, and as 3401 * such, cannot acquire any new parents. 3402 */ 3403 if (zio->io_done) 3404 zio->io_done(zio); 3405 3406 mutex_enter(&zio->io_lock); 3407 zio->io_state[ZIO_WAIT_DONE] = 1; 3408 mutex_exit(&zio->io_lock); 3409 3410 for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) { 3411 zio_link_t *zl = zio->io_walk_link; 3412 pio_next = zio_walk_parents(zio); 3413 zio_remove_child(pio, zio, zl); 3414 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3415 } 3416 3417 if (zio->io_waiter != NULL) { 3418 mutex_enter(&zio->io_lock); 3419 zio->io_executor = NULL; 3420 cv_broadcast(&zio->io_cv); 3421 mutex_exit(&zio->io_lock); 3422 } else { 3423 zio_destroy(zio); 3424 } 3425 3426 return (ZIO_PIPELINE_STOP); 3427} 3428 3429/* 3430 * ========================================================================== 3431 * I/O pipeline definition 3432 * ========================================================================== 3433 */ 3434static zio_pipe_stage_t *zio_pipeline[] = { 3435 NULL, 3436 zio_read_bp_init, 3437 zio_free_bp_init, 3438 zio_issue_async, 3439 zio_write_bp_init, 3440 zio_checksum_generate, 3441 zio_nop_write, 3442 zio_ddt_read_start, 3443 zio_ddt_read_done, 3444 zio_ddt_write, 3445 zio_ddt_free, 3446 zio_gang_assemble, 3447 zio_gang_issue, 3448 zio_dva_allocate, 3449 zio_dva_free, 3450 zio_dva_claim, 3451 zio_ready, 3452 zio_vdev_io_start, 3453 zio_vdev_io_done, 3454 zio_vdev_io_assess, 3455 zio_checksum_verify, 3456 zio_done 3457}; 3458 3459 3460 3461 3462/* 3463 * Compare two zbookmark_phys_t's to see which we would reach first in a 3464 * pre-order traversal of the object tree. 3465 * 3466 * This is simple in every case aside from the meta-dnode object. For all other 3467 * objects, we traverse them in order (object 1 before object 2, and so on). 3468 * However, all of these objects are traversed while traversing object 0, since 3469 * the data it points to is the list of objects. Thus, we need to convert to a 3470 * canonical representation so we can compare meta-dnode bookmarks to 3471 * non-meta-dnode bookmarks. 3472 * 3473 * We do this by calculating "equivalents" for each field of the zbookmark. 3474 * zbookmarks outside of the meta-dnode use their own object and level, and 3475 * calculate the level 0 equivalent (the first L0 blkid that is contained in the 3476 * blocks this bookmark refers to) by multiplying their blkid by their span 3477 * (the number of L0 blocks contained within one block at their level). 3478 * zbookmarks inside the meta-dnode calculate their object equivalent 3479 * (which is L0equiv * dnodes per data block), use 0 for their L0equiv, and use 3480 * level + 1<<31 (any value larger than a level could ever be) for their level. 3481 * This causes them to always compare before a bookmark in their object 3482 * equivalent, compare appropriately to bookmarks in other objects, and to 3483 * compare appropriately to other bookmarks in the meta-dnode. 3484 */ 3485int 3486zbookmark_compare(uint16_t dbss1, uint8_t ibs1, uint16_t dbss2, uint8_t ibs2, 3487 const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2) 3488{ 3489 /* 3490 * These variables represent the "equivalent" values for the zbookmark, 3491 * after converting zbookmarks inside the meta dnode to their 3492 * normal-object equivalents. 3493 */ 3494 uint64_t zb1obj, zb2obj; 3495 uint64_t zb1L0, zb2L0; 3496 uint64_t zb1level, zb2level; 3497 3498 if (zb1->zb_object == zb2->zb_object && 3499 zb1->zb_level == zb2->zb_level && 3500 zb1->zb_blkid == zb2->zb_blkid) 3501 return (0); 3502 3503 /* 3504 * BP_SPANB calculates the span in blocks. 3505 */ 3506 zb1L0 = (zb1->zb_blkid) * BP_SPANB(ibs1, zb1->zb_level); 3507 zb2L0 = (zb2->zb_blkid) * BP_SPANB(ibs2, zb2->zb_level); 3508 3509 if (zb1->zb_object == DMU_META_DNODE_OBJECT) { 3510 zb1obj = zb1L0 * (dbss1 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT)); 3511 zb1L0 = 0; 3512 zb1level = zb1->zb_level + COMPARE_META_LEVEL; 3513 } else { 3514 zb1obj = zb1->zb_object; 3515 zb1level = zb1->zb_level; 3516 } 3517 3518 if (zb2->zb_object == DMU_META_DNODE_OBJECT) { 3519 zb2obj = zb2L0 * (dbss2 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT)); 3520 zb2L0 = 0; 3521 zb2level = zb2->zb_level + COMPARE_META_LEVEL; 3522 } else { 3523 zb2obj = zb2->zb_object; 3524 zb2level = zb2->zb_level; 3525 } 3526 3527 /* Now that we have a canonical representation, do the comparison. */ 3528 if (zb1obj != zb2obj) 3529 return (zb1obj < zb2obj ? -1 : 1); 3530 else if (zb1L0 != zb2L0) 3531 return (zb1L0 < zb2L0 ? -1 : 1); 3532 else if (zb1level != zb2level) 3533 return (zb1level > zb2level ? -1 : 1); 3534 /* 3535 * This can (theoretically) happen if the bookmarks have the same object 3536 * and level, but different blkids, if the block sizes are not the same. 3537 * There is presently no way to change the indirect block sizes 3538 */ 3539 return (0); 3540} 3541 3542/* 3543 * This function checks the following: given that last_block is the place that 3544 * our traversal stopped last time, does that guarantee that we've visited 3545 * every node under subtree_root? Therefore, we can't just use the raw output 3546 * of zbookmark_compare. We have to pass in a modified version of 3547 * subtree_root; by incrementing the block id, and then checking whether 3548 * last_block is before or equal to that, we can tell whether or not having 3549 * visited last_block implies that all of subtree_root's children have been 3550 * visited. 3551 */ 3552boolean_t 3553zbookmark_subtree_completed(const dnode_phys_t *dnp, 3554 const zbookmark_phys_t *subtree_root, const zbookmark_phys_t *last_block) 3555{ 3556 zbookmark_phys_t mod_zb = *subtree_root; 3557 mod_zb.zb_blkid++; 3558 ASSERT(last_block->zb_level == 0); 3559 3560 /* The objset_phys_t isn't before anything. */ 3561 if (dnp == NULL) 3562 return (B_FALSE); 3563 3564 /* 3565 * We pass in 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT) for the 3566 * data block size in sectors, because that variable is only used if 3567 * the bookmark refers to a block in the meta-dnode. Since we don't 3568 * know without examining it what object it refers to, and there's no 3569 * harm in passing in this value in other cases, we always pass it in. 3570 * 3571 * We pass in 0 for the indirect block size shift because zb2 must be 3572 * level 0. The indirect block size is only used to calculate the span 3573 * of the bookmark, but since the bookmark must be level 0, the span is 3574 * always 1, so the math works out. 3575 * 3576 * If you make changes to how the zbookmark_compare code works, be sure 3577 * to make sure that this code still works afterwards. 3578 */ 3579 return (zbookmark_compare(dnp->dn_datablkszsec, dnp->dn_indblkshift, 3580 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT), 0, &mod_zb, 3581 last_block) <= 0); 3582} 3583