zio.c revision 329486
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, 2017 by Delphix. All rights reserved. 24 * Copyright (c) 2011 Nexenta Systems, Inc. All rights reserved. 25 * Copyright (c) 2014 Integros [integros.com] 26 */ 27 28#include <sys/sysmacros.h> 29#include <sys/zfs_context.h> 30#include <sys/fm/fs/zfs.h> 31#include <sys/spa.h> 32#include <sys/txg.h> 33#include <sys/spa_impl.h> 34#include <sys/vdev_impl.h> 35#include <sys/zio_impl.h> 36#include <sys/zio_compress.h> 37#include <sys/zio_checksum.h> 38#include <sys/dmu_objset.h> 39#include <sys/arc.h> 40#include <sys/ddt.h> 41#include <sys/trim_map.h> 42#include <sys/blkptr.h> 43#include <sys/zfeature.h> 44#include <sys/metaslab_impl.h> 45#include <sys/abd.h> 46 47SYSCTL_DECL(_vfs_zfs); 48SYSCTL_NODE(_vfs_zfs, OID_AUTO, zio, CTLFLAG_RW, 0, "ZFS ZIO"); 49#if defined(__amd64__) 50static int zio_use_uma = 1; 51#else 52static int zio_use_uma = 0; 53#endif 54SYSCTL_INT(_vfs_zfs_zio, OID_AUTO, use_uma, CTLFLAG_RDTUN, &zio_use_uma, 0, 55 "Use uma(9) for ZIO allocations"); 56static int zio_exclude_metadata = 0; 57SYSCTL_INT(_vfs_zfs_zio, OID_AUTO, exclude_metadata, CTLFLAG_RDTUN, &zio_exclude_metadata, 0, 58 "Exclude metadata buffers from dumps as well"); 59 60zio_trim_stats_t zio_trim_stats = { 61 { "bytes", KSTAT_DATA_UINT64, 62 "Number of bytes successfully TRIMmed" }, 63 { "success", KSTAT_DATA_UINT64, 64 "Number of successful TRIM requests" }, 65 { "unsupported", KSTAT_DATA_UINT64, 66 "Number of TRIM requests that failed because TRIM is not supported" }, 67 { "failed", KSTAT_DATA_UINT64, 68 "Number of TRIM requests that failed for reasons other than not supported" }, 69}; 70 71static kstat_t *zio_trim_ksp; 72 73/* 74 * ========================================================================== 75 * I/O type descriptions 76 * ========================================================================== 77 */ 78const char *zio_type_name[ZIO_TYPES] = { 79 "zio_null", "zio_read", "zio_write", "zio_free", "zio_claim", 80 "zio_ioctl" 81}; 82 83boolean_t zio_dva_throttle_enabled = B_TRUE; 84SYSCTL_INT(_vfs_zfs_zio, OID_AUTO, dva_throttle_enabled, CTLFLAG_RDTUN, 85 &zio_dva_throttle_enabled, 0, ""); 86 87/* 88 * ========================================================================== 89 * I/O kmem caches 90 * ========================================================================== 91 */ 92kmem_cache_t *zio_cache; 93kmem_cache_t *zio_link_cache; 94kmem_cache_t *zio_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; 95kmem_cache_t *zio_data_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; 96 97#ifdef _KERNEL 98extern vmem_t *zio_alloc_arena; 99#endif 100 101#define ZIO_PIPELINE_CONTINUE 0x100 102#define ZIO_PIPELINE_STOP 0x101 103 104#define BP_SPANB(indblkshift, level) \ 105 (((uint64_t)1) << ((level) * ((indblkshift) - SPA_BLKPTRSHIFT))) 106#define COMPARE_META_LEVEL 0x80000000ul 107/* 108 * The following actions directly effect the spa's sync-to-convergence logic. 109 * The values below define the sync pass when we start performing the action. 110 * Care should be taken when changing these values as they directly impact 111 * spa_sync() performance. Tuning these values may introduce subtle performance 112 * pathologies and should only be done in the context of performance analysis. 113 * These tunables will eventually be removed and replaced with #defines once 114 * enough analysis has been done to determine optimal values. 115 * 116 * The 'zfs_sync_pass_deferred_free' pass must be greater than 1 to ensure that 117 * regular blocks are not deferred. 118 */ 119int zfs_sync_pass_deferred_free = 2; /* defer frees starting in this pass */ 120SYSCTL_INT(_vfs_zfs, OID_AUTO, sync_pass_deferred_free, CTLFLAG_RDTUN, 121 &zfs_sync_pass_deferred_free, 0, "defer frees starting in this pass"); 122int zfs_sync_pass_dont_compress = 5; /* don't compress starting in this pass */ 123SYSCTL_INT(_vfs_zfs, OID_AUTO, sync_pass_dont_compress, CTLFLAG_RDTUN, 124 &zfs_sync_pass_dont_compress, 0, "don't compress starting in this pass"); 125int zfs_sync_pass_rewrite = 2; /* rewrite new bps starting in this pass */ 126SYSCTL_INT(_vfs_zfs, OID_AUTO, sync_pass_rewrite, CTLFLAG_RDTUN, 127 &zfs_sync_pass_rewrite, 0, "rewrite new bps starting in this pass"); 128 129/* 130 * An allocating zio is one that either currently has the DVA allocate 131 * stage set or will have it later in its lifetime. 132 */ 133#define IO_IS_ALLOCATING(zio) ((zio)->io_orig_pipeline & ZIO_STAGE_DVA_ALLOCATE) 134 135boolean_t zio_requeue_io_start_cut_in_line = B_TRUE; 136 137#ifdef illumos 138#ifdef ZFS_DEBUG 139int zio_buf_debug_limit = 16384; 140#else 141int zio_buf_debug_limit = 0; 142#endif 143#endif 144 145static void zio_taskq_dispatch(zio_t *, zio_taskq_type_t, boolean_t); 146 147void 148zio_init(void) 149{ 150 size_t c; 151 zio_cache = kmem_cache_create("zio_cache", 152 sizeof (zio_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 153 zio_link_cache = kmem_cache_create("zio_link_cache", 154 sizeof (zio_link_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 155 if (!zio_use_uma) 156 goto out; 157 158 /* 159 * For small buffers, we want a cache for each multiple of 160 * SPA_MINBLOCKSIZE. For larger buffers, we want a cache 161 * for each quarter-power of 2. 162 */ 163 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { 164 size_t size = (c + 1) << SPA_MINBLOCKSHIFT; 165 size_t p2 = size; 166 size_t align = 0; 167 int cflags = zio_exclude_metadata ? KMC_NODEBUG : 0; 168 169 while (!ISP2(p2)) 170 p2 &= p2 - 1; 171 172#ifdef illumos 173#ifndef _KERNEL 174 /* 175 * If we are using watchpoints, put each buffer on its own page, 176 * to eliminate the performance overhead of trapping to the 177 * kernel when modifying a non-watched buffer that shares the 178 * page with a watched buffer. 179 */ 180 if (arc_watch && !IS_P2ALIGNED(size, PAGESIZE)) 181 continue; 182#endif 183#endif /* illumos */ 184 if (size <= 4 * SPA_MINBLOCKSIZE) { 185 align = SPA_MINBLOCKSIZE; 186 } else if (IS_P2ALIGNED(size, p2 >> 2)) { 187 align = MIN(p2 >> 2, PAGESIZE); 188 } 189 190 if (align != 0) { 191 char name[36]; 192 (void) sprintf(name, "zio_buf_%lu", (ulong_t)size); 193 zio_buf_cache[c] = kmem_cache_create(name, size, 194 align, NULL, NULL, NULL, NULL, NULL, cflags); 195 196 /* 197 * Since zio_data bufs do not appear in crash dumps, we 198 * pass KMC_NOTOUCH so that no allocator metadata is 199 * stored with the buffers. 200 */ 201 (void) sprintf(name, "zio_data_buf_%lu", (ulong_t)size); 202 zio_data_buf_cache[c] = kmem_cache_create(name, size, 203 align, NULL, NULL, NULL, NULL, NULL, 204 cflags | KMC_NOTOUCH | KMC_NODEBUG); 205 } 206 } 207 208 while (--c != 0) { 209 ASSERT(zio_buf_cache[c] != NULL); 210 if (zio_buf_cache[c - 1] == NULL) 211 zio_buf_cache[c - 1] = zio_buf_cache[c]; 212 213 ASSERT(zio_data_buf_cache[c] != NULL); 214 if (zio_data_buf_cache[c - 1] == NULL) 215 zio_data_buf_cache[c - 1] = zio_data_buf_cache[c]; 216 } 217out: 218 219 zio_inject_init(); 220 221 zio_trim_ksp = kstat_create("zfs", 0, "zio_trim", "misc", 222 KSTAT_TYPE_NAMED, 223 sizeof(zio_trim_stats) / sizeof(kstat_named_t), 224 KSTAT_FLAG_VIRTUAL); 225 226 if (zio_trim_ksp != NULL) { 227 zio_trim_ksp->ks_data = &zio_trim_stats; 228 kstat_install(zio_trim_ksp); 229 } 230} 231 232void 233zio_fini(void) 234{ 235 size_t c; 236 kmem_cache_t *last_cache = NULL; 237 kmem_cache_t *last_data_cache = NULL; 238 239 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { 240 if (zio_buf_cache[c] != last_cache) { 241 last_cache = zio_buf_cache[c]; 242 kmem_cache_destroy(zio_buf_cache[c]); 243 } 244 zio_buf_cache[c] = NULL; 245 246 if (zio_data_buf_cache[c] != last_data_cache) { 247 last_data_cache = zio_data_buf_cache[c]; 248 kmem_cache_destroy(zio_data_buf_cache[c]); 249 } 250 zio_data_buf_cache[c] = NULL; 251 } 252 253 kmem_cache_destroy(zio_link_cache); 254 kmem_cache_destroy(zio_cache); 255 256 zio_inject_fini(); 257 258 if (zio_trim_ksp != NULL) { 259 kstat_delete(zio_trim_ksp); 260 zio_trim_ksp = NULL; 261 } 262} 263 264/* 265 * ========================================================================== 266 * Allocate and free I/O buffers 267 * ========================================================================== 268 */ 269 270/* 271 * Use zio_buf_alloc to allocate ZFS metadata. This data will appear in a 272 * crashdump if the kernel panics, so use it judiciously. Obviously, it's 273 * useful to inspect ZFS metadata, but if possible, we should avoid keeping 274 * excess / transient data in-core during a crashdump. 275 */ 276void * 277zio_buf_alloc(size_t size) 278{ 279 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 280 int flags = zio_exclude_metadata ? KM_NODEBUG : 0; 281 282 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 283 284 if (zio_use_uma) 285 return (kmem_cache_alloc(zio_buf_cache[c], KM_PUSHPAGE)); 286 else 287 return (kmem_alloc(size, KM_SLEEP|flags)); 288} 289 290/* 291 * Use zio_data_buf_alloc to allocate data. The data will not appear in a 292 * crashdump if the kernel panics. This exists so that we will limit the amount 293 * of ZFS data that shows up in a kernel crashdump. (Thus reducing the amount 294 * of kernel heap dumped to disk when the kernel panics) 295 */ 296void * 297zio_data_buf_alloc(size_t size) 298{ 299 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 300 301 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 302 303 if (zio_use_uma) 304 return (kmem_cache_alloc(zio_data_buf_cache[c], KM_PUSHPAGE)); 305 else 306 return (kmem_alloc(size, KM_SLEEP | KM_NODEBUG)); 307} 308 309void 310zio_buf_free(void *buf, size_t size) 311{ 312 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 313 314 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 315 316 if (zio_use_uma) 317 kmem_cache_free(zio_buf_cache[c], buf); 318 else 319 kmem_free(buf, size); 320} 321 322void 323zio_data_buf_free(void *buf, size_t size) 324{ 325 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 326 327 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 328 329 if (zio_use_uma) 330 kmem_cache_free(zio_data_buf_cache[c], buf); 331 else 332 kmem_free(buf, size); 333} 334 335/* 336 * ========================================================================== 337 * Push and pop I/O transform buffers 338 * ========================================================================== 339 */ 340void 341zio_push_transform(zio_t *zio, abd_t *data, uint64_t size, uint64_t bufsize, 342 zio_transform_func_t *transform) 343{ 344 zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP); 345 346 /* 347 * Ensure that anyone expecting this zio to contain a linear ABD isn't 348 * going to get a nasty surprise when they try to access the data. 349 */ 350#ifdef illumos 351 IMPLY(abd_is_linear(zio->io_abd), abd_is_linear(data)); 352#else 353 IMPLY(zio->io_abd != NULL && abd_is_linear(zio->io_abd), 354 abd_is_linear(data)); 355#endif 356 357 zt->zt_orig_abd = zio->io_abd; 358 zt->zt_orig_size = zio->io_size; 359 zt->zt_bufsize = bufsize; 360 zt->zt_transform = transform; 361 362 zt->zt_next = zio->io_transform_stack; 363 zio->io_transform_stack = zt; 364 365 zio->io_abd = data; 366 zio->io_size = size; 367} 368 369void 370zio_pop_transforms(zio_t *zio) 371{ 372 zio_transform_t *zt; 373 374 while ((zt = zio->io_transform_stack) != NULL) { 375 if (zt->zt_transform != NULL) 376 zt->zt_transform(zio, 377 zt->zt_orig_abd, zt->zt_orig_size); 378 379 if (zt->zt_bufsize != 0) 380 abd_free(zio->io_abd); 381 382 zio->io_abd = zt->zt_orig_abd; 383 zio->io_size = zt->zt_orig_size; 384 zio->io_transform_stack = zt->zt_next; 385 386 kmem_free(zt, sizeof (zio_transform_t)); 387 } 388} 389 390/* 391 * ========================================================================== 392 * I/O transform callbacks for subblocks and decompression 393 * ========================================================================== 394 */ 395static void 396zio_subblock(zio_t *zio, abd_t *data, uint64_t size) 397{ 398 ASSERT(zio->io_size > size); 399 400 if (zio->io_type == ZIO_TYPE_READ) 401 abd_copy(data, zio->io_abd, size); 402} 403 404static void 405zio_decompress(zio_t *zio, abd_t *data, uint64_t size) 406{ 407 if (zio->io_error == 0) { 408 void *tmp = abd_borrow_buf(data, size); 409 int ret = zio_decompress_data(BP_GET_COMPRESS(zio->io_bp), 410 zio->io_abd, tmp, zio->io_size, size); 411 abd_return_buf_copy(data, tmp, size); 412 413 if (ret != 0) 414 zio->io_error = SET_ERROR(EIO); 415 } 416} 417 418/* 419 * ========================================================================== 420 * I/O parent/child relationships and pipeline interlocks 421 * ========================================================================== 422 */ 423zio_t * 424zio_walk_parents(zio_t *cio, zio_link_t **zl) 425{ 426 list_t *pl = &cio->io_parent_list; 427 428 *zl = (*zl == NULL) ? list_head(pl) : list_next(pl, *zl); 429 if (*zl == NULL) 430 return (NULL); 431 432 ASSERT((*zl)->zl_child == cio); 433 return ((*zl)->zl_parent); 434} 435 436zio_t * 437zio_walk_children(zio_t *pio, zio_link_t **zl) 438{ 439 list_t *cl = &pio->io_child_list; 440 441 *zl = (*zl == NULL) ? list_head(cl) : list_next(cl, *zl); 442 if (*zl == NULL) 443 return (NULL); 444 445 ASSERT((*zl)->zl_parent == pio); 446 return ((*zl)->zl_child); 447} 448 449zio_t * 450zio_unique_parent(zio_t *cio) 451{ 452 zio_link_t *zl = NULL; 453 zio_t *pio = zio_walk_parents(cio, &zl); 454 455 VERIFY3P(zio_walk_parents(cio, &zl), ==, NULL); 456 return (pio); 457} 458 459void 460zio_add_child(zio_t *pio, zio_t *cio) 461{ 462 zio_link_t *zl = kmem_cache_alloc(zio_link_cache, KM_SLEEP); 463 464 /* 465 * Logical I/Os can have logical, gang, or vdev children. 466 * Gang I/Os can have gang or vdev children. 467 * Vdev I/Os can only have vdev children. 468 * The following ASSERT captures all of these constraints. 469 */ 470 ASSERT3S(cio->io_child_type, <=, pio->io_child_type); 471 472 zl->zl_parent = pio; 473 zl->zl_child = cio; 474 475 mutex_enter(&cio->io_lock); 476 mutex_enter(&pio->io_lock); 477 478 ASSERT(pio->io_state[ZIO_WAIT_DONE] == 0); 479 480 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 481 pio->io_children[cio->io_child_type][w] += !cio->io_state[w]; 482 483 list_insert_head(&pio->io_child_list, zl); 484 list_insert_head(&cio->io_parent_list, zl); 485 486 pio->io_child_count++; 487 cio->io_parent_count++; 488 489 mutex_exit(&pio->io_lock); 490 mutex_exit(&cio->io_lock); 491} 492 493static void 494zio_remove_child(zio_t *pio, zio_t *cio, zio_link_t *zl) 495{ 496 ASSERT(zl->zl_parent == pio); 497 ASSERT(zl->zl_child == cio); 498 499 mutex_enter(&cio->io_lock); 500 mutex_enter(&pio->io_lock); 501 502 list_remove(&pio->io_child_list, zl); 503 list_remove(&cio->io_parent_list, zl); 504 505 pio->io_child_count--; 506 cio->io_parent_count--; 507 508 mutex_exit(&pio->io_lock); 509 mutex_exit(&cio->io_lock); 510 511 kmem_cache_free(zio_link_cache, zl); 512} 513 514static boolean_t 515zio_wait_for_children(zio_t *zio, enum zio_child child, enum zio_wait_type wait) 516{ 517 uint64_t *countp = &zio->io_children[child][wait]; 518 boolean_t waiting = B_FALSE; 519 520 mutex_enter(&zio->io_lock); 521 ASSERT(zio->io_stall == NULL); 522 if (*countp != 0) { 523 zio->io_stage >>= 1; 524 ASSERT3U(zio->io_stage, !=, ZIO_STAGE_OPEN); 525 zio->io_stall = countp; 526 waiting = B_TRUE; 527 } 528 mutex_exit(&zio->io_lock); 529 530 return (waiting); 531} 532 533static void 534zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait) 535{ 536 uint64_t *countp = &pio->io_children[zio->io_child_type][wait]; 537 int *errorp = &pio->io_child_error[zio->io_child_type]; 538 539 mutex_enter(&pio->io_lock); 540 if (zio->io_error && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE)) 541 *errorp = zio_worst_error(*errorp, zio->io_error); 542 pio->io_reexecute |= zio->io_reexecute; 543 ASSERT3U(*countp, >, 0); 544 545 (*countp)--; 546 547 if (*countp == 0 && pio->io_stall == countp) { 548 zio_taskq_type_t type = 549 pio->io_stage < ZIO_STAGE_VDEV_IO_START ? ZIO_TASKQ_ISSUE : 550 ZIO_TASKQ_INTERRUPT; 551 pio->io_stall = NULL; 552 mutex_exit(&pio->io_lock); 553 /* 554 * Dispatch the parent zio in its own taskq so that 555 * the child can continue to make progress. This also 556 * prevents overflowing the stack when we have deeply nested 557 * parent-child relationships. 558 */ 559 zio_taskq_dispatch(pio, type, B_FALSE); 560 } else { 561 mutex_exit(&pio->io_lock); 562 } 563} 564 565static void 566zio_inherit_child_errors(zio_t *zio, enum zio_child c) 567{ 568 if (zio->io_child_error[c] != 0 && zio->io_error == 0) 569 zio->io_error = zio->io_child_error[c]; 570} 571 572int 573zio_bookmark_compare(const void *x1, const void *x2) 574{ 575 const zio_t *z1 = x1; 576 const zio_t *z2 = x2; 577 578 if (z1->io_bookmark.zb_objset < z2->io_bookmark.zb_objset) 579 return (-1); 580 if (z1->io_bookmark.zb_objset > z2->io_bookmark.zb_objset) 581 return (1); 582 583 if (z1->io_bookmark.zb_object < z2->io_bookmark.zb_object) 584 return (-1); 585 if (z1->io_bookmark.zb_object > z2->io_bookmark.zb_object) 586 return (1); 587 588 if (z1->io_bookmark.zb_level < z2->io_bookmark.zb_level) 589 return (-1); 590 if (z1->io_bookmark.zb_level > z2->io_bookmark.zb_level) 591 return (1); 592 593 if (z1->io_bookmark.zb_blkid < z2->io_bookmark.zb_blkid) 594 return (-1); 595 if (z1->io_bookmark.zb_blkid > z2->io_bookmark.zb_blkid) 596 return (1); 597 598 if (z1 < z2) 599 return (-1); 600 if (z1 > z2) 601 return (1); 602 603 return (0); 604} 605 606/* 607 * ========================================================================== 608 * Create the various types of I/O (read, write, free, etc) 609 * ========================================================================== 610 */ 611static zio_t * 612zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 613 abd_t *data, uint64_t lsize, uint64_t psize, zio_done_func_t *done, 614 void *private, zio_type_t type, zio_priority_t priority, 615 enum zio_flag flags, vdev_t *vd, uint64_t offset, 616 const zbookmark_phys_t *zb, enum zio_stage stage, enum zio_stage pipeline) 617{ 618 zio_t *zio; 619 620 ASSERT3U(type == ZIO_TYPE_FREE || psize, <=, SPA_MAXBLOCKSIZE); 621 ASSERT(P2PHASE(psize, SPA_MINBLOCKSIZE) == 0); 622 ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0); 623 624 ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER)); 625 ASSERT(!bp || !(flags & ZIO_FLAG_CONFIG_WRITER)); 626 ASSERT(vd || stage == ZIO_STAGE_OPEN); 627 628 IMPLY(lsize != psize, (flags & ZIO_FLAG_RAW) != 0); 629 630 zio = kmem_cache_alloc(zio_cache, KM_SLEEP); 631 bzero(zio, sizeof (zio_t)); 632 633 mutex_init(&zio->io_lock, NULL, MUTEX_DEFAULT, NULL); 634 cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL); 635 636 list_create(&zio->io_parent_list, sizeof (zio_link_t), 637 offsetof(zio_link_t, zl_parent_node)); 638 list_create(&zio->io_child_list, sizeof (zio_link_t), 639 offsetof(zio_link_t, zl_child_node)); 640 metaslab_trace_init(&zio->io_alloc_list); 641 642 if (vd != NULL) 643 zio->io_child_type = ZIO_CHILD_VDEV; 644 else if (flags & ZIO_FLAG_GANG_CHILD) 645 zio->io_child_type = ZIO_CHILD_GANG; 646 else if (flags & ZIO_FLAG_DDT_CHILD) 647 zio->io_child_type = ZIO_CHILD_DDT; 648 else 649 zio->io_child_type = ZIO_CHILD_LOGICAL; 650 651 if (bp != NULL) { 652 zio->io_bp = (blkptr_t *)bp; 653 zio->io_bp_copy = *bp; 654 zio->io_bp_orig = *bp; 655 if (type != ZIO_TYPE_WRITE || 656 zio->io_child_type == ZIO_CHILD_DDT) 657 zio->io_bp = &zio->io_bp_copy; /* so caller can free */ 658 if (zio->io_child_type == ZIO_CHILD_LOGICAL) 659 zio->io_logical = zio; 660 if (zio->io_child_type > ZIO_CHILD_GANG && BP_IS_GANG(bp)) 661 pipeline |= ZIO_GANG_STAGES; 662 } 663 664 zio->io_spa = spa; 665 zio->io_txg = txg; 666 zio->io_done = done; 667 zio->io_private = private; 668 zio->io_type = type; 669 zio->io_priority = priority; 670 zio->io_vd = vd; 671 zio->io_offset = offset; 672 zio->io_orig_abd = zio->io_abd = data; 673 zio->io_orig_size = zio->io_size = psize; 674 zio->io_lsize = lsize; 675 zio->io_orig_flags = zio->io_flags = flags; 676 zio->io_orig_stage = zio->io_stage = stage; 677 zio->io_orig_pipeline = zio->io_pipeline = pipeline; 678 zio->io_pipeline_trace = ZIO_STAGE_OPEN; 679 680 zio->io_state[ZIO_WAIT_READY] = (stage >= ZIO_STAGE_READY); 681 zio->io_state[ZIO_WAIT_DONE] = (stage >= ZIO_STAGE_DONE); 682 683 if (zb != NULL) 684 zio->io_bookmark = *zb; 685 686 if (pio != NULL) { 687 if (zio->io_logical == NULL) 688 zio->io_logical = pio->io_logical; 689 if (zio->io_child_type == ZIO_CHILD_GANG) 690 zio->io_gang_leader = pio->io_gang_leader; 691 zio_add_child(pio, zio); 692 } 693 694 return (zio); 695} 696 697static void 698zio_destroy(zio_t *zio) 699{ 700 metaslab_trace_fini(&zio->io_alloc_list); 701 list_destroy(&zio->io_parent_list); 702 list_destroy(&zio->io_child_list); 703 mutex_destroy(&zio->io_lock); 704 cv_destroy(&zio->io_cv); 705 kmem_cache_free(zio_cache, zio); 706} 707 708zio_t * 709zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, zio_done_func_t *done, 710 void *private, enum zio_flag flags) 711{ 712 zio_t *zio; 713 714 zio = zio_create(pio, spa, 0, NULL, NULL, 0, 0, done, private, 715 ZIO_TYPE_NULL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL, 716 ZIO_STAGE_OPEN, ZIO_INTERLOCK_PIPELINE); 717 718 return (zio); 719} 720 721zio_t * 722zio_root(spa_t *spa, zio_done_func_t *done, void *private, enum zio_flag flags) 723{ 724 return (zio_null(NULL, spa, NULL, done, private, flags)); 725} 726 727void 728zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp) 729{ 730 if (!DMU_OT_IS_VALID(BP_GET_TYPE(bp))) { 731 zfs_panic_recover("blkptr at %p has invalid TYPE %llu", 732 bp, (longlong_t)BP_GET_TYPE(bp)); 733 } 734 if (BP_GET_CHECKSUM(bp) >= ZIO_CHECKSUM_FUNCTIONS || 735 BP_GET_CHECKSUM(bp) <= ZIO_CHECKSUM_ON) { 736 zfs_panic_recover("blkptr at %p has invalid CHECKSUM %llu", 737 bp, (longlong_t)BP_GET_CHECKSUM(bp)); 738 } 739 if (BP_GET_COMPRESS(bp) >= ZIO_COMPRESS_FUNCTIONS || 740 BP_GET_COMPRESS(bp) <= ZIO_COMPRESS_ON) { 741 zfs_panic_recover("blkptr at %p has invalid COMPRESS %llu", 742 bp, (longlong_t)BP_GET_COMPRESS(bp)); 743 } 744 if (BP_GET_LSIZE(bp) > SPA_MAXBLOCKSIZE) { 745 zfs_panic_recover("blkptr at %p has invalid LSIZE %llu", 746 bp, (longlong_t)BP_GET_LSIZE(bp)); 747 } 748 if (BP_GET_PSIZE(bp) > SPA_MAXBLOCKSIZE) { 749 zfs_panic_recover("blkptr at %p has invalid PSIZE %llu", 750 bp, (longlong_t)BP_GET_PSIZE(bp)); 751 } 752 753 if (BP_IS_EMBEDDED(bp)) { 754 if (BPE_GET_ETYPE(bp) > NUM_BP_EMBEDDED_TYPES) { 755 zfs_panic_recover("blkptr at %p has invalid ETYPE %llu", 756 bp, (longlong_t)BPE_GET_ETYPE(bp)); 757 } 758 } 759 760 /* 761 * Pool-specific checks. 762 * 763 * Note: it would be nice to verify that the blk_birth and 764 * BP_PHYSICAL_BIRTH() are not too large. However, spa_freeze() 765 * allows the birth time of log blocks (and dmu_sync()-ed blocks 766 * that are in the log) to be arbitrarily large. 767 */ 768 for (int i = 0; i < BP_GET_NDVAS(bp); i++) { 769 uint64_t vdevid = DVA_GET_VDEV(&bp->blk_dva[i]); 770 if (vdevid >= spa->spa_root_vdev->vdev_children) { 771 zfs_panic_recover("blkptr at %p DVA %u has invalid " 772 "VDEV %llu", 773 bp, i, (longlong_t)vdevid); 774 continue; 775 } 776 vdev_t *vd = spa->spa_root_vdev->vdev_child[vdevid]; 777 if (vd == NULL) { 778 zfs_panic_recover("blkptr at %p DVA %u has invalid " 779 "VDEV %llu", 780 bp, i, (longlong_t)vdevid); 781 continue; 782 } 783 if (vd->vdev_ops == &vdev_hole_ops) { 784 zfs_panic_recover("blkptr at %p DVA %u has hole " 785 "VDEV %llu", 786 bp, i, (longlong_t)vdevid); 787 continue; 788 } 789 if (vd->vdev_ops == &vdev_missing_ops) { 790 /* 791 * "missing" vdevs are valid during import, but we 792 * don't have their detailed info (e.g. asize), so 793 * we can't perform any more checks on them. 794 */ 795 continue; 796 } 797 uint64_t offset = DVA_GET_OFFSET(&bp->blk_dva[i]); 798 uint64_t asize = DVA_GET_ASIZE(&bp->blk_dva[i]); 799 if (BP_IS_GANG(bp)) 800 asize = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE); 801 if (offset + asize > vd->vdev_asize) { 802 zfs_panic_recover("blkptr at %p DVA %u has invalid " 803 "OFFSET %llu", 804 bp, i, (longlong_t)offset); 805 } 806 } 807} 808 809zio_t * 810zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, 811 abd_t *data, uint64_t size, zio_done_func_t *done, void *private, 812 zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb) 813{ 814 zio_t *zio; 815 816 zfs_blkptr_verify(spa, bp); 817 818 zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp, 819 data, size, size, done, private, 820 ZIO_TYPE_READ, priority, flags, NULL, 0, zb, 821 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 822 ZIO_DDT_CHILD_READ_PIPELINE : ZIO_READ_PIPELINE); 823 824 return (zio); 825} 826 827zio_t * 828zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, 829 abd_t *data, uint64_t lsize, uint64_t psize, const zio_prop_t *zp, 830 zio_done_func_t *ready, zio_done_func_t *children_ready, 831 zio_done_func_t *physdone, zio_done_func_t *done, 832 void *private, zio_priority_t priority, enum zio_flag flags, 833 const zbookmark_phys_t *zb) 834{ 835 zio_t *zio; 836 837 ASSERT(zp->zp_checksum >= ZIO_CHECKSUM_OFF && 838 zp->zp_checksum < ZIO_CHECKSUM_FUNCTIONS && 839 zp->zp_compress >= ZIO_COMPRESS_OFF && 840 zp->zp_compress < ZIO_COMPRESS_FUNCTIONS && 841 DMU_OT_IS_VALID(zp->zp_type) && 842 zp->zp_level < 32 && 843 zp->zp_copies > 0 && 844 zp->zp_copies <= spa_max_replication(spa)); 845 846 zio = zio_create(pio, spa, txg, bp, data, lsize, psize, done, private, 847 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 848 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 849 ZIO_DDT_CHILD_WRITE_PIPELINE : ZIO_WRITE_PIPELINE); 850 851 zio->io_ready = ready; 852 zio->io_children_ready = children_ready; 853 zio->io_physdone = physdone; 854 zio->io_prop = *zp; 855 856 /* 857 * Data can be NULL if we are going to call zio_write_override() to 858 * provide the already-allocated BP. But we may need the data to 859 * verify a dedup hit (if requested). In this case, don't try to 860 * dedup (just take the already-allocated BP verbatim). 861 */ 862 if (data == NULL && zio->io_prop.zp_dedup_verify) { 863 zio->io_prop.zp_dedup = zio->io_prop.zp_dedup_verify = B_FALSE; 864 } 865 866 return (zio); 867} 868 869zio_t * 870zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, abd_t *data, 871 uint64_t size, zio_done_func_t *done, void *private, 872 zio_priority_t priority, enum zio_flag flags, zbookmark_phys_t *zb) 873{ 874 zio_t *zio; 875 876 zio = zio_create(pio, spa, txg, bp, data, size, size, done, private, 877 ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_IO_REWRITE, NULL, 0, zb, 878 ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE); 879 880 return (zio); 881} 882 883void 884zio_write_override(zio_t *zio, blkptr_t *bp, int copies, boolean_t nopwrite) 885{ 886 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 887 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 888 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 889 ASSERT(zio->io_txg == spa_syncing_txg(zio->io_spa)); 890 891 /* 892 * We must reset the io_prop to match the values that existed 893 * when the bp was first written by dmu_sync() keeping in mind 894 * that nopwrite and dedup are mutually exclusive. 895 */ 896 zio->io_prop.zp_dedup = nopwrite ? B_FALSE : zio->io_prop.zp_dedup; 897 zio->io_prop.zp_nopwrite = nopwrite; 898 zio->io_prop.zp_copies = copies; 899 zio->io_bp_override = bp; 900} 901 902void 903zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp) 904{ 905 906 /* 907 * The check for EMBEDDED is a performance optimization. We 908 * process the free here (by ignoring it) rather than 909 * putting it on the list and then processing it in zio_free_sync(). 910 */ 911 if (BP_IS_EMBEDDED(bp)) 912 return; 913 metaslab_check_free(spa, bp); 914 915 /* 916 * Frees that are for the currently-syncing txg, are not going to be 917 * deferred, and which will not need to do a read (i.e. not GANG or 918 * DEDUP), can be processed immediately. Otherwise, put them on the 919 * in-memory list for later processing. 920 */ 921 if (zfs_trim_enabled || BP_IS_GANG(bp) || BP_GET_DEDUP(bp) || 922 txg != spa->spa_syncing_txg || 923 spa_sync_pass(spa) >= zfs_sync_pass_deferred_free) { 924 bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp); 925 } else { 926 VERIFY0(zio_wait(zio_free_sync(NULL, spa, txg, bp, 927 BP_GET_PSIZE(bp), 0))); 928 } 929} 930 931zio_t * 932zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 933 uint64_t size, enum zio_flag flags) 934{ 935 zio_t *zio; 936 enum zio_stage stage = ZIO_FREE_PIPELINE; 937 938 ASSERT(!BP_IS_HOLE(bp)); 939 ASSERT(spa_syncing_txg(spa) == txg); 940 ASSERT(spa_sync_pass(spa) < zfs_sync_pass_deferred_free); 941 942 if (BP_IS_EMBEDDED(bp)) 943 return (zio_null(pio, spa, NULL, NULL, NULL, 0)); 944 945 metaslab_check_free(spa, bp); 946 arc_freed(spa, bp); 947 948 if (zfs_trim_enabled) 949 stage |= ZIO_STAGE_ISSUE_ASYNC | ZIO_STAGE_VDEV_IO_START | 950 ZIO_STAGE_VDEV_IO_ASSESS; 951 /* 952 * GANG and DEDUP blocks can induce a read (for the gang block header, 953 * or the DDT), so issue them asynchronously so that this thread is 954 * not tied up. 955 */ 956 else if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp)) 957 stage |= ZIO_STAGE_ISSUE_ASYNC; 958 959 flags |= ZIO_FLAG_DONT_QUEUE; 960 961 zio = zio_create(pio, spa, txg, bp, NULL, size, 962 size, NULL, NULL, ZIO_TYPE_FREE, ZIO_PRIORITY_NOW, 963 flags, NULL, 0, NULL, ZIO_STAGE_OPEN, stage); 964 965 return (zio); 966} 967 968zio_t * 969zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 970 zio_done_func_t *done, void *private, enum zio_flag flags) 971{ 972 zio_t *zio; 973 974 dprintf_bp(bp, "claiming in txg %llu", txg); 975 976 if (BP_IS_EMBEDDED(bp)) 977 return (zio_null(pio, spa, NULL, NULL, NULL, 0)); 978 979 /* 980 * A claim is an allocation of a specific block. Claims are needed 981 * to support immediate writes in the intent log. The issue is that 982 * immediate writes contain committed data, but in a txg that was 983 * *not* committed. Upon opening the pool after an unclean shutdown, 984 * the intent log claims all blocks that contain immediate write data 985 * so that the SPA knows they're in use. 986 * 987 * All claims *must* be resolved in the first txg -- before the SPA 988 * starts allocating blocks -- so that nothing is allocated twice. 989 * If txg == 0 we just verify that the block is claimable. 990 */ 991 ASSERT3U(spa->spa_uberblock.ub_rootbp.blk_birth, <, spa_first_txg(spa)); 992 ASSERT(txg == spa_first_txg(spa) || txg == 0); 993 ASSERT(!BP_GET_DEDUP(bp) || !spa_writeable(spa)); /* zdb(1M) */ 994 995 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 996 BP_GET_PSIZE(bp), done, private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW, 997 flags, NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE); 998 ASSERT0(zio->io_queued_timestamp); 999 1000 return (zio); 1001} 1002 1003zio_t * 1004zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd, uint64_t offset, 1005 uint64_t size, zio_done_func_t *done, void *private, 1006 zio_priority_t priority, enum zio_flag flags) 1007{ 1008 zio_t *zio; 1009 int c; 1010 1011 if (vd->vdev_children == 0) { 1012 zio = zio_create(pio, spa, 0, NULL, NULL, 0, 0, done, private, 1013 ZIO_TYPE_IOCTL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL, 1014 ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE); 1015 1016 zio->io_cmd = cmd; 1017 } else { 1018 zio = zio_null(pio, spa, NULL, NULL, NULL, flags); 1019 1020 for (c = 0; c < vd->vdev_children; c++) 1021 zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd, 1022 offset, size, done, private, priority, flags)); 1023 } 1024 1025 return (zio); 1026} 1027 1028zio_t * 1029zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 1030 abd_t *data, int checksum, zio_done_func_t *done, void *private, 1031 zio_priority_t priority, enum zio_flag flags, boolean_t labels) 1032{ 1033 zio_t *zio; 1034 1035 ASSERT(vd->vdev_children == 0); 1036 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 1037 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 1038 ASSERT3U(offset + size, <=, vd->vdev_psize); 1039 1040 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, size, done, 1041 private, ZIO_TYPE_READ, priority, flags | ZIO_FLAG_PHYSICAL, vd, 1042 offset, NULL, ZIO_STAGE_OPEN, ZIO_READ_PHYS_PIPELINE); 1043 1044 zio->io_prop.zp_checksum = checksum; 1045 1046 return (zio); 1047} 1048 1049zio_t * 1050zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 1051 abd_t *data, int checksum, zio_done_func_t *done, void *private, 1052 zio_priority_t priority, enum zio_flag flags, boolean_t labels) 1053{ 1054 zio_t *zio; 1055 1056 ASSERT(vd->vdev_children == 0); 1057 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 1058 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 1059 ASSERT3U(offset + size, <=, vd->vdev_psize); 1060 1061 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, size, done, 1062 private, ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_PHYSICAL, vd, 1063 offset, NULL, ZIO_STAGE_OPEN, ZIO_WRITE_PHYS_PIPELINE); 1064 1065 zio->io_prop.zp_checksum = checksum; 1066 1067 if (zio_checksum_table[checksum].ci_flags & ZCHECKSUM_FLAG_EMBEDDED) { 1068 /* 1069 * zec checksums are necessarily destructive -- they modify 1070 * the end of the write buffer to hold the verifier/checksum. 1071 * Therefore, we must make a local copy in case the data is 1072 * being written to multiple places in parallel. 1073 */ 1074 abd_t *wbuf = abd_alloc_sametype(data, size); 1075 abd_copy(wbuf, data, size); 1076 1077 zio_push_transform(zio, wbuf, size, size, NULL); 1078 } 1079 1080 return (zio); 1081} 1082 1083/* 1084 * Create a child I/O to do some work for us. 1085 */ 1086zio_t * 1087zio_vdev_child_io(zio_t *pio, blkptr_t *bp, vdev_t *vd, uint64_t offset, 1088 abd_t *data, uint64_t size, int type, zio_priority_t priority, 1089 enum zio_flag flags, zio_done_func_t *done, void *private) 1090{ 1091 enum zio_stage pipeline = ZIO_VDEV_CHILD_PIPELINE; 1092 zio_t *zio; 1093 1094 ASSERT(vd->vdev_parent == 1095 (pio->io_vd ? pio->io_vd : pio->io_spa->spa_root_vdev)); 1096 1097 if (type == ZIO_TYPE_READ && bp != NULL) { 1098 /* 1099 * If we have the bp, then the child should perform the 1100 * checksum and the parent need not. This pushes error 1101 * detection as close to the leaves as possible and 1102 * eliminates redundant checksums in the interior nodes. 1103 */ 1104 pipeline |= ZIO_STAGE_CHECKSUM_VERIFY; 1105 pio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 1106 } 1107 1108 /* Not all IO types require vdev io done stage e.g. free */ 1109 if (!(pio->io_pipeline & ZIO_STAGE_VDEV_IO_DONE)) 1110 pipeline &= ~ZIO_STAGE_VDEV_IO_DONE; 1111 1112 if (vd->vdev_children == 0) 1113 offset += VDEV_LABEL_START_SIZE; 1114 1115 flags |= ZIO_VDEV_CHILD_FLAGS(pio) | ZIO_FLAG_DONT_PROPAGATE; 1116 1117 /* 1118 * If we've decided to do a repair, the write is not speculative -- 1119 * even if the original read was. 1120 */ 1121 if (flags & ZIO_FLAG_IO_REPAIR) 1122 flags &= ~ZIO_FLAG_SPECULATIVE; 1123 1124 /* 1125 * If we're creating a child I/O that is not associated with a 1126 * top-level vdev, then the child zio is not an allocating I/O. 1127 * If this is a retried I/O then we ignore it since we will 1128 * have already processed the original allocating I/O. 1129 */ 1130 if (flags & ZIO_FLAG_IO_ALLOCATING && 1131 (vd != vd->vdev_top || (flags & ZIO_FLAG_IO_RETRY))) { 1132 metaslab_class_t *mc = spa_normal_class(pio->io_spa); 1133 1134 ASSERT(mc->mc_alloc_throttle_enabled); 1135 ASSERT(type == ZIO_TYPE_WRITE); 1136 ASSERT(priority == ZIO_PRIORITY_ASYNC_WRITE); 1137 ASSERT(!(flags & ZIO_FLAG_IO_REPAIR)); 1138 ASSERT(!(pio->io_flags & ZIO_FLAG_IO_REWRITE) || 1139 pio->io_child_type == ZIO_CHILD_GANG); 1140 1141 flags &= ~ZIO_FLAG_IO_ALLOCATING; 1142 } 1143 1144 zio = zio_create(pio, pio->io_spa, pio->io_txg, bp, data, size, size, 1145 done, private, type, priority, flags, vd, offset, &pio->io_bookmark, 1146 ZIO_STAGE_VDEV_IO_START >> 1, pipeline); 1147 ASSERT3U(zio->io_child_type, ==, ZIO_CHILD_VDEV); 1148 1149 zio->io_physdone = pio->io_physdone; 1150 if (vd->vdev_ops->vdev_op_leaf && zio->io_logical != NULL) 1151 zio->io_logical->io_phys_children++; 1152 1153 return (zio); 1154} 1155 1156zio_t * 1157zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, abd_t *data, uint64_t size, 1158 int type, zio_priority_t priority, enum zio_flag flags, 1159 zio_done_func_t *done, void *private) 1160{ 1161 zio_t *zio; 1162 1163 ASSERT(vd->vdev_ops->vdev_op_leaf); 1164 1165 zio = zio_create(NULL, vd->vdev_spa, 0, NULL, 1166 data, size, size, done, private, type, priority, 1167 flags | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY | ZIO_FLAG_DELEGATED, 1168 vd, offset, NULL, 1169 ZIO_STAGE_VDEV_IO_START >> 1, ZIO_VDEV_CHILD_PIPELINE); 1170 1171 return (zio); 1172} 1173 1174void 1175zio_flush(zio_t *zio, vdev_t *vd) 1176{ 1177 zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE, 0, 0, 1178 NULL, NULL, ZIO_PRIORITY_NOW, 1179 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY)); 1180} 1181 1182zio_t * 1183zio_trim(zio_t *zio, spa_t *spa, vdev_t *vd, uint64_t offset, uint64_t size) 1184{ 1185 1186 ASSERT(vd->vdev_ops->vdev_op_leaf); 1187 1188 return (zio_create(zio, spa, 0, NULL, NULL, size, size, NULL, NULL, 1189 ZIO_TYPE_FREE, ZIO_PRIORITY_TRIM, ZIO_FLAG_DONT_AGGREGATE | 1190 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY, 1191 vd, offset, NULL, ZIO_STAGE_OPEN, ZIO_FREE_PHYS_PIPELINE)); 1192} 1193 1194void 1195zio_shrink(zio_t *zio, uint64_t size) 1196{ 1197 ASSERT3P(zio->io_executor, ==, NULL); 1198 ASSERT3P(zio->io_orig_size, ==, zio->io_size); 1199 ASSERT3U(size, <=, zio->io_size); 1200 1201 /* 1202 * We don't shrink for raidz because of problems with the 1203 * reconstruction when reading back less than the block size. 1204 * Note, BP_IS_RAIDZ() assumes no compression. 1205 */ 1206 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 1207 if (!BP_IS_RAIDZ(zio->io_bp)) { 1208 /* we are not doing a raw write */ 1209 ASSERT3U(zio->io_size, ==, zio->io_lsize); 1210 zio->io_orig_size = zio->io_size = zio->io_lsize = size; 1211 } 1212} 1213 1214/* 1215 * ========================================================================== 1216 * Prepare to read and write logical blocks 1217 * ========================================================================== 1218 */ 1219 1220static int 1221zio_read_bp_init(zio_t *zio) 1222{ 1223 blkptr_t *bp = zio->io_bp; 1224 1225 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF && 1226 zio->io_child_type == ZIO_CHILD_LOGICAL && 1227 !(zio->io_flags & ZIO_FLAG_RAW)) { 1228 uint64_t psize = 1229 BP_IS_EMBEDDED(bp) ? BPE_GET_PSIZE(bp) : BP_GET_PSIZE(bp); 1230 zio_push_transform(zio, abd_alloc_sametype(zio->io_abd, psize), 1231 psize, psize, zio_decompress); 1232 } 1233 1234 if (BP_IS_EMBEDDED(bp) && BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA) { 1235 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1236 1237 int psize = BPE_GET_PSIZE(bp); 1238 void *data = abd_borrow_buf(zio->io_abd, psize); 1239 decode_embedded_bp_compressed(bp, data); 1240 abd_return_buf_copy(zio->io_abd, data, psize); 1241 } else { 1242 ASSERT(!BP_IS_EMBEDDED(bp)); 1243 } 1244 1245 if (!DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) && BP_GET_LEVEL(bp) == 0) 1246 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 1247 1248 if (BP_GET_TYPE(bp) == DMU_OT_DDT_ZAP) 1249 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 1250 1251 if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL) 1252 zio->io_pipeline = ZIO_DDT_READ_PIPELINE; 1253 1254 return (ZIO_PIPELINE_CONTINUE); 1255} 1256 1257static int 1258zio_write_bp_init(zio_t *zio) 1259{ 1260 if (!IO_IS_ALLOCATING(zio)) 1261 return (ZIO_PIPELINE_CONTINUE); 1262 1263 ASSERT(zio->io_child_type != ZIO_CHILD_DDT); 1264 1265 if (zio->io_bp_override) { 1266 blkptr_t *bp = zio->io_bp; 1267 zio_prop_t *zp = &zio->io_prop; 1268 1269 ASSERT(bp->blk_birth != zio->io_txg); 1270 ASSERT(BP_GET_DEDUP(zio->io_bp_override) == 0); 1271 1272 *bp = *zio->io_bp_override; 1273 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1274 1275 if (BP_IS_EMBEDDED(bp)) 1276 return (ZIO_PIPELINE_CONTINUE); 1277 1278 /* 1279 * If we've been overridden and nopwrite is set then 1280 * set the flag accordingly to indicate that a nopwrite 1281 * has already occurred. 1282 */ 1283 if (!BP_IS_HOLE(bp) && zp->zp_nopwrite) { 1284 ASSERT(!zp->zp_dedup); 1285 ASSERT3U(BP_GET_CHECKSUM(bp), ==, zp->zp_checksum); 1286 zio->io_flags |= ZIO_FLAG_NOPWRITE; 1287 return (ZIO_PIPELINE_CONTINUE); 1288 } 1289 1290 ASSERT(!zp->zp_nopwrite); 1291 1292 if (BP_IS_HOLE(bp) || !zp->zp_dedup) 1293 return (ZIO_PIPELINE_CONTINUE); 1294 1295 ASSERT((zio_checksum_table[zp->zp_checksum].ci_flags & 1296 ZCHECKSUM_FLAG_DEDUP) || zp->zp_dedup_verify); 1297 1298 if (BP_GET_CHECKSUM(bp) == zp->zp_checksum) { 1299 BP_SET_DEDUP(bp, 1); 1300 zio->io_pipeline |= ZIO_STAGE_DDT_WRITE; 1301 return (ZIO_PIPELINE_CONTINUE); 1302 } 1303 1304 /* 1305 * We were unable to handle this as an override bp, treat 1306 * it as a regular write I/O. 1307 */ 1308 zio->io_bp_override = NULL; 1309 *bp = zio->io_bp_orig; 1310 zio->io_pipeline = zio->io_orig_pipeline; 1311 } 1312 1313 return (ZIO_PIPELINE_CONTINUE); 1314} 1315 1316static int 1317zio_write_compress(zio_t *zio) 1318{ 1319 spa_t *spa = zio->io_spa; 1320 zio_prop_t *zp = &zio->io_prop; 1321 enum zio_compress compress = zp->zp_compress; 1322 blkptr_t *bp = zio->io_bp; 1323 uint64_t lsize = zio->io_lsize; 1324 uint64_t psize = zio->io_size; 1325 int pass = 1; 1326 1327 EQUIV(lsize != psize, (zio->io_flags & ZIO_FLAG_RAW) != 0); 1328 1329 /* 1330 * If our children haven't all reached the ready stage, 1331 * wait for them and then repeat this pipeline stage. 1332 */ 1333 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 1334 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_READY)) 1335 return (ZIO_PIPELINE_STOP); 1336 1337 if (!IO_IS_ALLOCATING(zio)) 1338 return (ZIO_PIPELINE_CONTINUE); 1339 1340 if (zio->io_children_ready != NULL) { 1341 /* 1342 * Now that all our children are ready, run the callback 1343 * associated with this zio in case it wants to modify the 1344 * data to be written. 1345 */ 1346 ASSERT3U(zp->zp_level, >, 0); 1347 zio->io_children_ready(zio); 1348 } 1349 1350 ASSERT(zio->io_child_type != ZIO_CHILD_DDT); 1351 ASSERT(zio->io_bp_override == NULL); 1352 1353 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg) { 1354 /* 1355 * We're rewriting an existing block, which means we're 1356 * working on behalf of spa_sync(). For spa_sync() to 1357 * converge, it must eventually be the case that we don't 1358 * have to allocate new blocks. But compression changes 1359 * the blocksize, which forces a reallocate, and makes 1360 * convergence take longer. Therefore, after the first 1361 * few passes, stop compressing to ensure convergence. 1362 */ 1363 pass = spa_sync_pass(spa); 1364 1365 ASSERT(zio->io_txg == spa_syncing_txg(spa)); 1366 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1367 ASSERT(!BP_GET_DEDUP(bp)); 1368 1369 if (pass >= zfs_sync_pass_dont_compress) 1370 compress = ZIO_COMPRESS_OFF; 1371 1372 /* Make sure someone doesn't change their mind on overwrites */ 1373 ASSERT(BP_IS_EMBEDDED(bp) || MIN(zp->zp_copies + BP_IS_GANG(bp), 1374 spa_max_replication(spa)) == BP_GET_NDVAS(bp)); 1375 } 1376 1377 /* If it's a compressed write that is not raw, compress the buffer. */ 1378 if (compress != ZIO_COMPRESS_OFF && psize == lsize) { 1379 void *cbuf = zio_buf_alloc(lsize); 1380 psize = zio_compress_data(compress, zio->io_abd, cbuf, lsize); 1381 if (psize == 0 || psize == lsize) { 1382 compress = ZIO_COMPRESS_OFF; 1383 zio_buf_free(cbuf, lsize); 1384 } else if (!zp->zp_dedup && psize <= BPE_PAYLOAD_SIZE && 1385 zp->zp_level == 0 && !DMU_OT_HAS_FILL(zp->zp_type) && 1386 spa_feature_is_enabled(spa, SPA_FEATURE_EMBEDDED_DATA)) { 1387 encode_embedded_bp_compressed(bp, 1388 cbuf, compress, lsize, psize); 1389 BPE_SET_ETYPE(bp, BP_EMBEDDED_TYPE_DATA); 1390 BP_SET_TYPE(bp, zio->io_prop.zp_type); 1391 BP_SET_LEVEL(bp, zio->io_prop.zp_level); 1392 zio_buf_free(cbuf, lsize); 1393 bp->blk_birth = zio->io_txg; 1394 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1395 ASSERT(spa_feature_is_active(spa, 1396 SPA_FEATURE_EMBEDDED_DATA)); 1397 return (ZIO_PIPELINE_CONTINUE); 1398 } else { 1399 /* 1400 * Round up compressed size up to the ashift 1401 * of the smallest-ashift device, and zero the tail. 1402 * This ensures that the compressed size of the BP 1403 * (and thus compressratio property) are correct, 1404 * in that we charge for the padding used to fill out 1405 * the last sector. 1406 */ 1407 ASSERT3U(spa->spa_min_ashift, >=, SPA_MINBLOCKSHIFT); 1408 size_t rounded = (size_t)P2ROUNDUP(psize, 1409 1ULL << spa->spa_min_ashift); 1410 if (rounded >= lsize) { 1411 compress = ZIO_COMPRESS_OFF; 1412 zio_buf_free(cbuf, lsize); 1413 psize = lsize; 1414 } else { 1415 abd_t *cdata = abd_get_from_buf(cbuf, lsize); 1416 abd_take_ownership_of_buf(cdata, B_TRUE); 1417 abd_zero_off(cdata, psize, rounded - psize); 1418 psize = rounded; 1419 zio_push_transform(zio, cdata, 1420 psize, lsize, NULL); 1421 } 1422 } 1423 1424 /* 1425 * We were unable to handle this as an override bp, treat 1426 * it as a regular write I/O. 1427 */ 1428 zio->io_bp_override = NULL; 1429 *bp = zio->io_bp_orig; 1430 zio->io_pipeline = zio->io_orig_pipeline; 1431 } else { 1432 ASSERT3U(psize, !=, 0); 1433 } 1434 1435 /* 1436 * The final pass of spa_sync() must be all rewrites, but the first 1437 * few passes offer a trade-off: allocating blocks defers convergence, 1438 * but newly allocated blocks are sequential, so they can be written 1439 * to disk faster. Therefore, we allow the first few passes of 1440 * spa_sync() to allocate new blocks, but force rewrites after that. 1441 * There should only be a handful of blocks after pass 1 in any case. 1442 */ 1443 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg && 1444 BP_GET_PSIZE(bp) == psize && 1445 pass >= zfs_sync_pass_rewrite) { 1446 ASSERT(psize != 0); 1447 enum zio_stage gang_stages = zio->io_pipeline & ZIO_GANG_STAGES; 1448 zio->io_pipeline = ZIO_REWRITE_PIPELINE | gang_stages; 1449 zio->io_flags |= ZIO_FLAG_IO_REWRITE; 1450 } else { 1451 BP_ZERO(bp); 1452 zio->io_pipeline = ZIO_WRITE_PIPELINE; 1453 } 1454 1455 if (psize == 0) { 1456 if (zio->io_bp_orig.blk_birth != 0 && 1457 spa_feature_is_active(spa, SPA_FEATURE_HOLE_BIRTH)) { 1458 BP_SET_LSIZE(bp, lsize); 1459 BP_SET_TYPE(bp, zp->zp_type); 1460 BP_SET_LEVEL(bp, zp->zp_level); 1461 BP_SET_BIRTH(bp, zio->io_txg, 0); 1462 } 1463 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1464 } else { 1465 ASSERT(zp->zp_checksum != ZIO_CHECKSUM_GANG_HEADER); 1466 BP_SET_LSIZE(bp, lsize); 1467 BP_SET_TYPE(bp, zp->zp_type); 1468 BP_SET_LEVEL(bp, zp->zp_level); 1469 BP_SET_PSIZE(bp, psize); 1470 BP_SET_COMPRESS(bp, compress); 1471 BP_SET_CHECKSUM(bp, zp->zp_checksum); 1472 BP_SET_DEDUP(bp, zp->zp_dedup); 1473 BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER); 1474 if (zp->zp_dedup) { 1475 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1476 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1477 zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE; 1478 } 1479 if (zp->zp_nopwrite) { 1480 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1481 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1482 zio->io_pipeline |= ZIO_STAGE_NOP_WRITE; 1483 } 1484 } 1485 return (ZIO_PIPELINE_CONTINUE); 1486} 1487 1488static int 1489zio_free_bp_init(zio_t *zio) 1490{ 1491 blkptr_t *bp = zio->io_bp; 1492 1493 if (zio->io_child_type == ZIO_CHILD_LOGICAL) { 1494 if (BP_GET_DEDUP(bp)) 1495 zio->io_pipeline = ZIO_DDT_FREE_PIPELINE; 1496 } 1497 1498 return (ZIO_PIPELINE_CONTINUE); 1499} 1500 1501/* 1502 * ========================================================================== 1503 * Execute the I/O pipeline 1504 * ========================================================================== 1505 */ 1506 1507static void 1508zio_taskq_dispatch(zio_t *zio, zio_taskq_type_t q, boolean_t cutinline) 1509{ 1510 spa_t *spa = zio->io_spa; 1511 zio_type_t t = zio->io_type; 1512 int flags = (cutinline ? TQ_FRONT : 0); 1513 1514 ASSERT(q == ZIO_TASKQ_ISSUE || q == ZIO_TASKQ_INTERRUPT); 1515 1516 /* 1517 * If we're a config writer or a probe, the normal issue and 1518 * interrupt threads may all be blocked waiting for the config lock. 1519 * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL. 1520 */ 1521 if (zio->io_flags & (ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_PROBE)) 1522 t = ZIO_TYPE_NULL; 1523 1524 /* 1525 * A similar issue exists for the L2ARC write thread until L2ARC 2.0. 1526 */ 1527 if (t == ZIO_TYPE_WRITE && zio->io_vd && zio->io_vd->vdev_aux) 1528 t = ZIO_TYPE_NULL; 1529 1530 /* 1531 * If this is a high priority I/O, then use the high priority taskq if 1532 * available. 1533 */ 1534 if (zio->io_priority == ZIO_PRIORITY_NOW && 1535 spa->spa_zio_taskq[t][q + 1].stqs_count != 0) 1536 q++; 1537 1538 ASSERT3U(q, <, ZIO_TASKQ_TYPES); 1539 1540 /* 1541 * NB: We are assuming that the zio can only be dispatched 1542 * to a single taskq at a time. It would be a grievous error 1543 * to dispatch the zio to another taskq at the same time. 1544 */ 1545#if defined(illumos) || !defined(_KERNEL) 1546 ASSERT(zio->io_tqent.tqent_next == NULL); 1547#else 1548 ASSERT(zio->io_tqent.tqent_task.ta_pending == 0); 1549#endif 1550 spa_taskq_dispatch_ent(spa, t, q, (task_func_t *)zio_execute, zio, 1551 flags, &zio->io_tqent); 1552} 1553 1554static boolean_t 1555zio_taskq_member(zio_t *zio, zio_taskq_type_t q) 1556{ 1557 kthread_t *executor = zio->io_executor; 1558 spa_t *spa = zio->io_spa; 1559 1560 for (zio_type_t t = 0; t < ZIO_TYPES; t++) { 1561 spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q]; 1562 uint_t i; 1563 for (i = 0; i < tqs->stqs_count; i++) { 1564 if (taskq_member(tqs->stqs_taskq[i], executor)) 1565 return (B_TRUE); 1566 } 1567 } 1568 1569 return (B_FALSE); 1570} 1571 1572static int 1573zio_issue_async(zio_t *zio) 1574{ 1575 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 1576 1577 return (ZIO_PIPELINE_STOP); 1578} 1579 1580void 1581zio_interrupt(zio_t *zio) 1582{ 1583 zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE); 1584} 1585 1586void 1587zio_delay_interrupt(zio_t *zio) 1588{ 1589 /* 1590 * The timeout_generic() function isn't defined in userspace, so 1591 * rather than trying to implement the function, the zio delay 1592 * functionality has been disabled for userspace builds. 1593 */ 1594 1595#ifdef _KERNEL 1596 /* 1597 * If io_target_timestamp is zero, then no delay has been registered 1598 * for this IO, thus jump to the end of this function and "skip" the 1599 * delay; issuing it directly to the zio layer. 1600 */ 1601 if (zio->io_target_timestamp != 0) { 1602 hrtime_t now = gethrtime(); 1603 1604 if (now >= zio->io_target_timestamp) { 1605 /* 1606 * This IO has already taken longer than the target 1607 * delay to complete, so we don't want to delay it 1608 * any longer; we "miss" the delay and issue it 1609 * directly to the zio layer. This is likely due to 1610 * the target latency being set to a value less than 1611 * the underlying hardware can satisfy (e.g. delay 1612 * set to 1ms, but the disks take 10ms to complete an 1613 * IO request). 1614 */ 1615 1616 DTRACE_PROBE2(zio__delay__miss, zio_t *, zio, 1617 hrtime_t, now); 1618 1619 zio_interrupt(zio); 1620 } else { 1621 hrtime_t diff = zio->io_target_timestamp - now; 1622 1623 DTRACE_PROBE3(zio__delay__hit, zio_t *, zio, 1624 hrtime_t, now, hrtime_t, diff); 1625 1626 (void) timeout_generic(CALLOUT_NORMAL, 1627 (void (*)(void *))zio_interrupt, zio, diff, 1, 0); 1628 } 1629 1630 return; 1631 } 1632#endif 1633 1634 DTRACE_PROBE1(zio__delay__skip, zio_t *, zio); 1635 zio_interrupt(zio); 1636} 1637 1638/* 1639 * Execute the I/O pipeline until one of the following occurs: 1640 * 1641 * (1) the I/O completes 1642 * (2) the pipeline stalls waiting for dependent child I/Os 1643 * (3) the I/O issues, so we're waiting for an I/O completion interrupt 1644 * (4) the I/O is delegated by vdev-level caching or aggregation 1645 * (5) the I/O is deferred due to vdev-level queueing 1646 * (6) the I/O is handed off to another thread. 1647 * 1648 * In all cases, the pipeline stops whenever there's no CPU work; it never 1649 * burns a thread in cv_wait(). 1650 * 1651 * There's no locking on io_stage because there's no legitimate way 1652 * for multiple threads to be attempting to process the same I/O. 1653 */ 1654static zio_pipe_stage_t *zio_pipeline[]; 1655 1656void 1657zio_execute(zio_t *zio) 1658{ 1659 zio->io_executor = curthread; 1660 1661 ASSERT3U(zio->io_queued_timestamp, >, 0); 1662 1663 while (zio->io_stage < ZIO_STAGE_DONE) { 1664 enum zio_stage pipeline = zio->io_pipeline; 1665 enum zio_stage stage = zio->io_stage; 1666 int rv; 1667 1668 ASSERT(!MUTEX_HELD(&zio->io_lock)); 1669 ASSERT(ISP2(stage)); 1670 ASSERT(zio->io_stall == NULL); 1671 1672 do { 1673 stage <<= 1; 1674 } while ((stage & pipeline) == 0); 1675 1676 ASSERT(stage <= ZIO_STAGE_DONE); 1677 1678 /* 1679 * If we are in interrupt context and this pipeline stage 1680 * will grab a config lock that is held across I/O, 1681 * or may wait for an I/O that needs an interrupt thread 1682 * to complete, issue async to avoid deadlock. 1683 * 1684 * For VDEV_IO_START, we cut in line so that the io will 1685 * be sent to disk promptly. 1686 */ 1687 if ((stage & ZIO_BLOCKING_STAGES) && zio->io_vd == NULL && 1688 zio_taskq_member(zio, ZIO_TASKQ_INTERRUPT)) { 1689 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ? 1690 zio_requeue_io_start_cut_in_line : B_FALSE; 1691 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut); 1692 return; 1693 } 1694 1695 zio->io_stage = stage; 1696 zio->io_pipeline_trace |= zio->io_stage; 1697 rv = zio_pipeline[highbit64(stage) - 1](zio); 1698 1699 if (rv == ZIO_PIPELINE_STOP) 1700 return; 1701 1702 ASSERT(rv == ZIO_PIPELINE_CONTINUE); 1703 } 1704} 1705 1706/* 1707 * ========================================================================== 1708 * Initiate I/O, either sync or async 1709 * ========================================================================== 1710 */ 1711int 1712zio_wait(zio_t *zio) 1713{ 1714 int error; 1715 1716 ASSERT3P(zio->io_stage, ==, ZIO_STAGE_OPEN); 1717 ASSERT3P(zio->io_executor, ==, NULL); 1718 1719 zio->io_waiter = curthread; 1720 ASSERT0(zio->io_queued_timestamp); 1721 zio->io_queued_timestamp = gethrtime(); 1722 1723 zio_execute(zio); 1724 1725 mutex_enter(&zio->io_lock); 1726 while (zio->io_executor != NULL) 1727 cv_wait(&zio->io_cv, &zio->io_lock); 1728 mutex_exit(&zio->io_lock); 1729 1730 error = zio->io_error; 1731 zio_destroy(zio); 1732 1733 return (error); 1734} 1735 1736void 1737zio_nowait(zio_t *zio) 1738{ 1739 ASSERT3P(zio->io_executor, ==, NULL); 1740 1741 if (zio->io_child_type == ZIO_CHILD_LOGICAL && 1742 zio_unique_parent(zio) == NULL) { 1743 /* 1744 * This is a logical async I/O with no parent to wait for it. 1745 * We add it to the spa_async_root_zio "Godfather" I/O which 1746 * will ensure they complete prior to unloading the pool. 1747 */ 1748 spa_t *spa = zio->io_spa; 1749 1750 zio_add_child(spa->spa_async_zio_root[CPU_SEQID], zio); 1751 } 1752 1753 ASSERT0(zio->io_queued_timestamp); 1754 zio->io_queued_timestamp = gethrtime(); 1755 zio_execute(zio); 1756} 1757 1758/* 1759 * ========================================================================== 1760 * Reexecute, cancel, or suspend/resume failed I/O 1761 * ========================================================================== 1762 */ 1763 1764static void 1765zio_reexecute(zio_t *pio) 1766{ 1767 zio_t *cio, *cio_next; 1768 1769 ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL); 1770 ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN); 1771 ASSERT(pio->io_gang_leader == NULL); 1772 ASSERT(pio->io_gang_tree == NULL); 1773 1774 pio->io_flags = pio->io_orig_flags; 1775 pio->io_stage = pio->io_orig_stage; 1776 pio->io_pipeline = pio->io_orig_pipeline; 1777 pio->io_reexecute = 0; 1778 pio->io_flags |= ZIO_FLAG_REEXECUTED; 1779 pio->io_pipeline_trace = 0; 1780 pio->io_error = 0; 1781 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1782 pio->io_state[w] = 0; 1783 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 1784 pio->io_child_error[c] = 0; 1785 1786 if (IO_IS_ALLOCATING(pio)) 1787 BP_ZERO(pio->io_bp); 1788 1789 /* 1790 * As we reexecute pio's children, new children could be created. 1791 * New children go to the head of pio's io_child_list, however, 1792 * so we will (correctly) not reexecute them. The key is that 1793 * the remainder of pio's io_child_list, from 'cio_next' onward, 1794 * cannot be affected by any side effects of reexecuting 'cio'. 1795 */ 1796 zio_link_t *zl = NULL; 1797 for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) { 1798 cio_next = zio_walk_children(pio, &zl); 1799 mutex_enter(&pio->io_lock); 1800 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1801 pio->io_children[cio->io_child_type][w]++; 1802 mutex_exit(&pio->io_lock); 1803 zio_reexecute(cio); 1804 } 1805 1806 /* 1807 * Now that all children have been reexecuted, execute the parent. 1808 * We don't reexecute "The Godfather" I/O here as it's the 1809 * responsibility of the caller to wait on him. 1810 */ 1811 if (!(pio->io_flags & ZIO_FLAG_GODFATHER)) { 1812 pio->io_queued_timestamp = gethrtime(); 1813 zio_execute(pio); 1814 } 1815} 1816 1817void 1818zio_suspend(spa_t *spa, zio_t *zio) 1819{ 1820 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC) 1821 fm_panic("Pool '%s' has encountered an uncorrectable I/O " 1822 "failure and the failure mode property for this pool " 1823 "is set to panic.", spa_name(spa)); 1824 1825 zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL, NULL, 0, 0); 1826 1827 mutex_enter(&spa->spa_suspend_lock); 1828 1829 if (spa->spa_suspend_zio_root == NULL) 1830 spa->spa_suspend_zio_root = zio_root(spa, NULL, NULL, 1831 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | 1832 ZIO_FLAG_GODFATHER); 1833 1834 spa->spa_suspended = B_TRUE; 1835 1836 if (zio != NULL) { 1837 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 1838 ASSERT(zio != spa->spa_suspend_zio_root); 1839 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1840 ASSERT(zio_unique_parent(zio) == NULL); 1841 ASSERT(zio->io_stage == ZIO_STAGE_DONE); 1842 zio_add_child(spa->spa_suspend_zio_root, zio); 1843 } 1844 1845 mutex_exit(&spa->spa_suspend_lock); 1846} 1847 1848int 1849zio_resume(spa_t *spa) 1850{ 1851 zio_t *pio; 1852 1853 /* 1854 * Reexecute all previously suspended i/o. 1855 */ 1856 mutex_enter(&spa->spa_suspend_lock); 1857 spa->spa_suspended = B_FALSE; 1858 cv_broadcast(&spa->spa_suspend_cv); 1859 pio = spa->spa_suspend_zio_root; 1860 spa->spa_suspend_zio_root = NULL; 1861 mutex_exit(&spa->spa_suspend_lock); 1862 1863 if (pio == NULL) 1864 return (0); 1865 1866 zio_reexecute(pio); 1867 return (zio_wait(pio)); 1868} 1869 1870void 1871zio_resume_wait(spa_t *spa) 1872{ 1873 mutex_enter(&spa->spa_suspend_lock); 1874 while (spa_suspended(spa)) 1875 cv_wait(&spa->spa_suspend_cv, &spa->spa_suspend_lock); 1876 mutex_exit(&spa->spa_suspend_lock); 1877} 1878 1879/* 1880 * ========================================================================== 1881 * Gang blocks. 1882 * 1883 * A gang block is a collection of small blocks that looks to the DMU 1884 * like one large block. When zio_dva_allocate() cannot find a block 1885 * of the requested size, due to either severe fragmentation or the pool 1886 * being nearly full, it calls zio_write_gang_block() to construct the 1887 * block from smaller fragments. 1888 * 1889 * A gang block consists of a gang header (zio_gbh_phys_t) and up to 1890 * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like 1891 * an indirect block: it's an array of block pointers. It consumes 1892 * only one sector and hence is allocatable regardless of fragmentation. 1893 * The gang header's bps point to its gang members, which hold the data. 1894 * 1895 * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg> 1896 * as the verifier to ensure uniqueness of the SHA256 checksum. 1897 * Critically, the gang block bp's blk_cksum is the checksum of the data, 1898 * not the gang header. This ensures that data block signatures (needed for 1899 * deduplication) are independent of how the block is physically stored. 1900 * 1901 * Gang blocks can be nested: a gang member may itself be a gang block. 1902 * Thus every gang block is a tree in which root and all interior nodes are 1903 * gang headers, and the leaves are normal blocks that contain user data. 1904 * The root of the gang tree is called the gang leader. 1905 * 1906 * To perform any operation (read, rewrite, free, claim) on a gang block, 1907 * zio_gang_assemble() first assembles the gang tree (minus data leaves) 1908 * in the io_gang_tree field of the original logical i/o by recursively 1909 * reading the gang leader and all gang headers below it. This yields 1910 * an in-core tree containing the contents of every gang header and the 1911 * bps for every constituent of the gang block. 1912 * 1913 * With the gang tree now assembled, zio_gang_issue() just walks the gang tree 1914 * and invokes a callback on each bp. To free a gang block, zio_gang_issue() 1915 * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp. 1916 * zio_claim_gang() provides a similarly trivial wrapper for zio_claim(). 1917 * zio_read_gang() is a wrapper around zio_read() that omits reading gang 1918 * headers, since we already have those in io_gang_tree. zio_rewrite_gang() 1919 * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite() 1920 * of the gang header plus zio_checksum_compute() of the data to update the 1921 * gang header's blk_cksum as described above. 1922 * 1923 * The two-phase assemble/issue model solves the problem of partial failure -- 1924 * what if you'd freed part of a gang block but then couldn't read the 1925 * gang header for another part? Assembling the entire gang tree first 1926 * ensures that all the necessary gang header I/O has succeeded before 1927 * starting the actual work of free, claim, or write. Once the gang tree 1928 * is assembled, free and claim are in-memory operations that cannot fail. 1929 * 1930 * In the event that a gang write fails, zio_dva_unallocate() walks the 1931 * gang tree to immediately free (i.e. insert back into the space map) 1932 * everything we've allocated. This ensures that we don't get ENOSPC 1933 * errors during repeated suspend/resume cycles due to a flaky device. 1934 * 1935 * Gang rewrites only happen during sync-to-convergence. If we can't assemble 1936 * the gang tree, we won't modify the block, so we can safely defer the free 1937 * (knowing that the block is still intact). If we *can* assemble the gang 1938 * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free 1939 * each constituent bp and we can allocate a new block on the next sync pass. 1940 * 1941 * In all cases, the gang tree allows complete recovery from partial failure. 1942 * ========================================================================== 1943 */ 1944 1945static void 1946zio_gang_issue_func_done(zio_t *zio) 1947{ 1948 abd_put(zio->io_abd); 1949} 1950 1951static zio_t * 1952zio_read_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data, 1953 uint64_t offset) 1954{ 1955 if (gn != NULL) 1956 return (pio); 1957 1958 return (zio_read(pio, pio->io_spa, bp, abd_get_offset(data, offset), 1959 BP_GET_PSIZE(bp), zio_gang_issue_func_done, 1960 NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 1961 &pio->io_bookmark)); 1962} 1963 1964static zio_t * 1965zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data, 1966 uint64_t offset) 1967{ 1968 zio_t *zio; 1969 1970 if (gn != NULL) { 1971 abd_t *gbh_abd = 1972 abd_get_from_buf(gn->gn_gbh, SPA_GANGBLOCKSIZE); 1973 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1974 gbh_abd, SPA_GANGBLOCKSIZE, zio_gang_issue_func_done, NULL, 1975 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 1976 &pio->io_bookmark); 1977 /* 1978 * As we rewrite each gang header, the pipeline will compute 1979 * a new gang block header checksum for it; but no one will 1980 * compute a new data checksum, so we do that here. The one 1981 * exception is the gang leader: the pipeline already computed 1982 * its data checksum because that stage precedes gang assembly. 1983 * (Presently, nothing actually uses interior data checksums; 1984 * this is just good hygiene.) 1985 */ 1986 if (gn != pio->io_gang_leader->io_gang_tree) { 1987 abd_t *buf = abd_get_offset(data, offset); 1988 1989 zio_checksum_compute(zio, BP_GET_CHECKSUM(bp), 1990 buf, BP_GET_PSIZE(bp)); 1991 1992 abd_put(buf); 1993 } 1994 /* 1995 * If we are here to damage data for testing purposes, 1996 * leave the GBH alone so that we can detect the damage. 1997 */ 1998 if (pio->io_gang_leader->io_flags & ZIO_FLAG_INDUCE_DAMAGE) 1999 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 2000 } else { 2001 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 2002 abd_get_offset(data, offset), BP_GET_PSIZE(bp), 2003 zio_gang_issue_func_done, NULL, pio->io_priority, 2004 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 2005 } 2006 2007 return (zio); 2008} 2009 2010/* ARGSUSED */ 2011static zio_t * 2012zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data, 2013 uint64_t offset) 2014{ 2015 return (zio_free_sync(pio, pio->io_spa, pio->io_txg, bp, 2016 BP_IS_GANG(bp) ? SPA_GANGBLOCKSIZE : BP_GET_PSIZE(bp), 2017 ZIO_GANG_CHILD_FLAGS(pio))); 2018} 2019 2020/* ARGSUSED */ 2021static zio_t * 2022zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data, 2023 uint64_t offset) 2024{ 2025 return (zio_claim(pio, pio->io_spa, pio->io_txg, bp, 2026 NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio))); 2027} 2028 2029static zio_gang_issue_func_t *zio_gang_issue_func[ZIO_TYPES] = { 2030 NULL, 2031 zio_read_gang, 2032 zio_rewrite_gang, 2033 zio_free_gang, 2034 zio_claim_gang, 2035 NULL 2036}; 2037 2038static void zio_gang_tree_assemble_done(zio_t *zio); 2039 2040static zio_gang_node_t * 2041zio_gang_node_alloc(zio_gang_node_t **gnpp) 2042{ 2043 zio_gang_node_t *gn; 2044 2045 ASSERT(*gnpp == NULL); 2046 2047 gn = kmem_zalloc(sizeof (*gn), KM_SLEEP); 2048 gn->gn_gbh = zio_buf_alloc(SPA_GANGBLOCKSIZE); 2049 *gnpp = gn; 2050 2051 return (gn); 2052} 2053 2054static void 2055zio_gang_node_free(zio_gang_node_t **gnpp) 2056{ 2057 zio_gang_node_t *gn = *gnpp; 2058 2059 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 2060 ASSERT(gn->gn_child[g] == NULL); 2061 2062 zio_buf_free(gn->gn_gbh, SPA_GANGBLOCKSIZE); 2063 kmem_free(gn, sizeof (*gn)); 2064 *gnpp = NULL; 2065} 2066 2067static void 2068zio_gang_tree_free(zio_gang_node_t **gnpp) 2069{ 2070 zio_gang_node_t *gn = *gnpp; 2071 2072 if (gn == NULL) 2073 return; 2074 2075 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 2076 zio_gang_tree_free(&gn->gn_child[g]); 2077 2078 zio_gang_node_free(gnpp); 2079} 2080 2081static void 2082zio_gang_tree_assemble(zio_t *gio, blkptr_t *bp, zio_gang_node_t **gnpp) 2083{ 2084 zio_gang_node_t *gn = zio_gang_node_alloc(gnpp); 2085 abd_t *gbh_abd = abd_get_from_buf(gn->gn_gbh, SPA_GANGBLOCKSIZE); 2086 2087 ASSERT(gio->io_gang_leader == gio); 2088 ASSERT(BP_IS_GANG(bp)); 2089 2090 zio_nowait(zio_read(gio, gio->io_spa, bp, gbh_abd, SPA_GANGBLOCKSIZE, 2091 zio_gang_tree_assemble_done, gn, gio->io_priority, 2092 ZIO_GANG_CHILD_FLAGS(gio), &gio->io_bookmark)); 2093} 2094 2095static void 2096zio_gang_tree_assemble_done(zio_t *zio) 2097{ 2098 zio_t *gio = zio->io_gang_leader; 2099 zio_gang_node_t *gn = zio->io_private; 2100 blkptr_t *bp = zio->io_bp; 2101 2102 ASSERT(gio == zio_unique_parent(zio)); 2103 ASSERT(zio->io_child_count == 0); 2104 2105 if (zio->io_error) 2106 return; 2107 2108 /* this ABD was created from a linear buf in zio_gang_tree_assemble */ 2109 if (BP_SHOULD_BYTESWAP(bp)) 2110 byteswap_uint64_array(abd_to_buf(zio->io_abd), zio->io_size); 2111 2112 ASSERT3P(abd_to_buf(zio->io_abd), ==, gn->gn_gbh); 2113 ASSERT(zio->io_size == SPA_GANGBLOCKSIZE); 2114 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 2115 2116 abd_put(zio->io_abd); 2117 2118 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 2119 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 2120 if (!BP_IS_GANG(gbp)) 2121 continue; 2122 zio_gang_tree_assemble(gio, gbp, &gn->gn_child[g]); 2123 } 2124} 2125 2126static void 2127zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, abd_t *data, 2128 uint64_t offset) 2129{ 2130 zio_t *gio = pio->io_gang_leader; 2131 zio_t *zio; 2132 2133 ASSERT(BP_IS_GANG(bp) == !!gn); 2134 ASSERT(BP_GET_CHECKSUM(bp) == BP_GET_CHECKSUM(gio->io_bp)); 2135 ASSERT(BP_GET_LSIZE(bp) == BP_GET_PSIZE(bp) || gn == gio->io_gang_tree); 2136 2137 /* 2138 * If you're a gang header, your data is in gn->gn_gbh. 2139 * If you're a gang member, your data is in 'data' and gn == NULL. 2140 */ 2141 zio = zio_gang_issue_func[gio->io_type](pio, bp, gn, data, offset); 2142 2143 if (gn != NULL) { 2144 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 2145 2146 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 2147 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 2148 if (BP_IS_HOLE(gbp)) 2149 continue; 2150 zio_gang_tree_issue(zio, gn->gn_child[g], gbp, data, 2151 offset); 2152 offset += BP_GET_PSIZE(gbp); 2153 } 2154 } 2155 2156 if (gn == gio->io_gang_tree && gio->io_abd != NULL) 2157 ASSERT3U(gio->io_size, ==, offset); 2158 2159 if (zio != pio) 2160 zio_nowait(zio); 2161} 2162 2163static int 2164zio_gang_assemble(zio_t *zio) 2165{ 2166 blkptr_t *bp = zio->io_bp; 2167 2168 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == NULL); 2169 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2170 2171 zio->io_gang_leader = zio; 2172 2173 zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree); 2174 2175 return (ZIO_PIPELINE_CONTINUE); 2176} 2177 2178static int 2179zio_gang_issue(zio_t *zio) 2180{ 2181 blkptr_t *bp = zio->io_bp; 2182 2183 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE)) 2184 return (ZIO_PIPELINE_STOP); 2185 2186 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio); 2187 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2188 2189 if (zio->io_child_error[ZIO_CHILD_GANG] == 0) 2190 zio_gang_tree_issue(zio, zio->io_gang_tree, bp, zio->io_abd, 2191 0); 2192 else 2193 zio_gang_tree_free(&zio->io_gang_tree); 2194 2195 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2196 2197 return (ZIO_PIPELINE_CONTINUE); 2198} 2199 2200static void 2201zio_write_gang_member_ready(zio_t *zio) 2202{ 2203 zio_t *pio = zio_unique_parent(zio); 2204 zio_t *gio = zio->io_gang_leader; 2205 dva_t *cdva = zio->io_bp->blk_dva; 2206 dva_t *pdva = pio->io_bp->blk_dva; 2207 uint64_t asize; 2208 2209 if (BP_IS_HOLE(zio->io_bp)) 2210 return; 2211 2212 ASSERT(BP_IS_HOLE(&zio->io_bp_orig)); 2213 2214 ASSERT(zio->io_child_type == ZIO_CHILD_GANG); 2215 ASSERT3U(zio->io_prop.zp_copies, ==, gio->io_prop.zp_copies); 2216 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp)); 2217 ASSERT3U(pio->io_prop.zp_copies, <=, BP_GET_NDVAS(pio->io_bp)); 2218 ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp)); 2219 2220 mutex_enter(&pio->io_lock); 2221 for (int d = 0; d < BP_GET_NDVAS(zio->io_bp); d++) { 2222 ASSERT(DVA_GET_GANG(&pdva[d])); 2223 asize = DVA_GET_ASIZE(&pdva[d]); 2224 asize += DVA_GET_ASIZE(&cdva[d]); 2225 DVA_SET_ASIZE(&pdva[d], asize); 2226 } 2227 mutex_exit(&pio->io_lock); 2228} 2229 2230static void 2231zio_write_gang_done(zio_t *zio) 2232{ 2233 abd_put(zio->io_abd); 2234} 2235 2236static int 2237zio_write_gang_block(zio_t *pio) 2238{ 2239 spa_t *spa = pio->io_spa; 2240 metaslab_class_t *mc = spa_normal_class(spa); 2241 blkptr_t *bp = pio->io_bp; 2242 zio_t *gio = pio->io_gang_leader; 2243 zio_t *zio; 2244 zio_gang_node_t *gn, **gnpp; 2245 zio_gbh_phys_t *gbh; 2246 abd_t *gbh_abd; 2247 uint64_t txg = pio->io_txg; 2248 uint64_t resid = pio->io_size; 2249 uint64_t lsize; 2250 int copies = gio->io_prop.zp_copies; 2251 int gbh_copies = MIN(copies + 1, spa_max_replication(spa)); 2252 zio_prop_t zp; 2253 int error; 2254 2255 int flags = METASLAB_HINTBP_FAVOR | METASLAB_GANG_HEADER; 2256 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 2257 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 2258 ASSERT(!(pio->io_flags & ZIO_FLAG_NODATA)); 2259 2260 flags |= METASLAB_ASYNC_ALLOC; 2261 VERIFY(refcount_held(&mc->mc_alloc_slots, pio)); 2262 2263 /* 2264 * The logical zio has already placed a reservation for 2265 * 'copies' allocation slots but gang blocks may require 2266 * additional copies. These additional copies 2267 * (i.e. gbh_copies - copies) are guaranteed to succeed 2268 * since metaslab_class_throttle_reserve() always allows 2269 * additional reservations for gang blocks. 2270 */ 2271 VERIFY(metaslab_class_throttle_reserve(mc, gbh_copies - copies, 2272 pio, flags)); 2273 } 2274 2275 error = metaslab_alloc(spa, mc, SPA_GANGBLOCKSIZE, 2276 bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp, flags, 2277 &pio->io_alloc_list, pio); 2278 if (error) { 2279 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 2280 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 2281 ASSERT(!(pio->io_flags & ZIO_FLAG_NODATA)); 2282 2283 /* 2284 * If we failed to allocate the gang block header then 2285 * we remove any additional allocation reservations that 2286 * we placed here. The original reservation will 2287 * be removed when the logical I/O goes to the ready 2288 * stage. 2289 */ 2290 metaslab_class_throttle_unreserve(mc, 2291 gbh_copies - copies, pio); 2292 } 2293 pio->io_error = error; 2294 return (ZIO_PIPELINE_CONTINUE); 2295 } 2296 2297 if (pio == gio) { 2298 gnpp = &gio->io_gang_tree; 2299 } else { 2300 gnpp = pio->io_private; 2301 ASSERT(pio->io_ready == zio_write_gang_member_ready); 2302 } 2303 2304 gn = zio_gang_node_alloc(gnpp); 2305 gbh = gn->gn_gbh; 2306 bzero(gbh, SPA_GANGBLOCKSIZE); 2307 gbh_abd = abd_get_from_buf(gbh, SPA_GANGBLOCKSIZE); 2308 2309 /* 2310 * Create the gang header. 2311 */ 2312 zio = zio_rewrite(pio, spa, txg, bp, gbh_abd, SPA_GANGBLOCKSIZE, 2313 zio_write_gang_done, NULL, pio->io_priority, 2314 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 2315 2316 /* 2317 * Create and nowait the gang children. 2318 */ 2319 for (int g = 0; resid != 0; resid -= lsize, g++) { 2320 lsize = P2ROUNDUP(resid / (SPA_GBH_NBLKPTRS - g), 2321 SPA_MINBLOCKSIZE); 2322 ASSERT(lsize >= SPA_MINBLOCKSIZE && lsize <= resid); 2323 2324 zp.zp_checksum = gio->io_prop.zp_checksum; 2325 zp.zp_compress = ZIO_COMPRESS_OFF; 2326 zp.zp_type = DMU_OT_NONE; 2327 zp.zp_level = 0; 2328 zp.zp_copies = gio->io_prop.zp_copies; 2329 zp.zp_dedup = B_FALSE; 2330 zp.zp_dedup_verify = B_FALSE; 2331 zp.zp_nopwrite = B_FALSE; 2332 2333 zio_t *cio = zio_write(zio, spa, txg, &gbh->zg_blkptr[g], 2334 abd_get_offset(pio->io_abd, pio->io_size - resid), lsize, 2335 lsize, &zp, zio_write_gang_member_ready, NULL, NULL, 2336 zio_write_gang_done, &gn->gn_child[g], pio->io_priority, 2337 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 2338 2339 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 2340 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 2341 ASSERT(!(pio->io_flags & ZIO_FLAG_NODATA)); 2342 2343 /* 2344 * Gang children won't throttle but we should 2345 * account for their work, so reserve an allocation 2346 * slot for them here. 2347 */ 2348 VERIFY(metaslab_class_throttle_reserve(mc, 2349 zp.zp_copies, cio, flags)); 2350 } 2351 zio_nowait(cio); 2352 } 2353 2354 /* 2355 * Set pio's pipeline to just wait for zio to finish. 2356 */ 2357 pio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2358 2359 zio_nowait(zio); 2360 2361 return (ZIO_PIPELINE_CONTINUE); 2362} 2363 2364/* 2365 * The zio_nop_write stage in the pipeline determines if allocating a 2366 * new bp is necessary. The nopwrite feature can handle writes in 2367 * either syncing or open context (i.e. zil writes) and as a result is 2368 * mutually exclusive with dedup. 2369 * 2370 * By leveraging a cryptographically secure checksum, such as SHA256, we 2371 * can compare the checksums of the new data and the old to determine if 2372 * allocating a new block is required. Note that our requirements for 2373 * cryptographic strength are fairly weak: there can't be any accidental 2374 * hash collisions, but we don't need to be secure against intentional 2375 * (malicious) collisions. To trigger a nopwrite, you have to be able 2376 * to write the file to begin with, and triggering an incorrect (hash 2377 * collision) nopwrite is no worse than simply writing to the file. 2378 * That said, there are no known attacks against the checksum algorithms 2379 * used for nopwrite, assuming that the salt and the checksums 2380 * themselves remain secret. 2381 */ 2382static int 2383zio_nop_write(zio_t *zio) 2384{ 2385 blkptr_t *bp = zio->io_bp; 2386 blkptr_t *bp_orig = &zio->io_bp_orig; 2387 zio_prop_t *zp = &zio->io_prop; 2388 2389 ASSERT(BP_GET_LEVEL(bp) == 0); 2390 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 2391 ASSERT(zp->zp_nopwrite); 2392 ASSERT(!zp->zp_dedup); 2393 ASSERT(zio->io_bp_override == NULL); 2394 ASSERT(IO_IS_ALLOCATING(zio)); 2395 2396 /* 2397 * Check to see if the original bp and the new bp have matching 2398 * characteristics (i.e. same checksum, compression algorithms, etc). 2399 * If they don't then just continue with the pipeline which will 2400 * allocate a new bp. 2401 */ 2402 if (BP_IS_HOLE(bp_orig) || 2403 !(zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_flags & 2404 ZCHECKSUM_FLAG_NOPWRITE) || 2405 BP_GET_CHECKSUM(bp) != BP_GET_CHECKSUM(bp_orig) || 2406 BP_GET_COMPRESS(bp) != BP_GET_COMPRESS(bp_orig) || 2407 BP_GET_DEDUP(bp) != BP_GET_DEDUP(bp_orig) || 2408 zp->zp_copies != BP_GET_NDVAS(bp_orig)) 2409 return (ZIO_PIPELINE_CONTINUE); 2410 2411 /* 2412 * If the checksums match then reset the pipeline so that we 2413 * avoid allocating a new bp and issuing any I/O. 2414 */ 2415 if (ZIO_CHECKSUM_EQUAL(bp->blk_cksum, bp_orig->blk_cksum)) { 2416 ASSERT(zio_checksum_table[zp->zp_checksum].ci_flags & 2417 ZCHECKSUM_FLAG_NOPWRITE); 2418 ASSERT3U(BP_GET_PSIZE(bp), ==, BP_GET_PSIZE(bp_orig)); 2419 ASSERT3U(BP_GET_LSIZE(bp), ==, BP_GET_LSIZE(bp_orig)); 2420 ASSERT(zp->zp_compress != ZIO_COMPRESS_OFF); 2421 ASSERT(bcmp(&bp->blk_prop, &bp_orig->blk_prop, 2422 sizeof (uint64_t)) == 0); 2423 2424 *bp = *bp_orig; 2425 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2426 zio->io_flags |= ZIO_FLAG_NOPWRITE; 2427 } 2428 2429 return (ZIO_PIPELINE_CONTINUE); 2430} 2431 2432/* 2433 * ========================================================================== 2434 * Dedup 2435 * ========================================================================== 2436 */ 2437static void 2438zio_ddt_child_read_done(zio_t *zio) 2439{ 2440 blkptr_t *bp = zio->io_bp; 2441 ddt_entry_t *dde = zio->io_private; 2442 ddt_phys_t *ddp; 2443 zio_t *pio = zio_unique_parent(zio); 2444 2445 mutex_enter(&pio->io_lock); 2446 ddp = ddt_phys_select(dde, bp); 2447 if (zio->io_error == 0) 2448 ddt_phys_clear(ddp); /* this ddp doesn't need repair */ 2449 2450 if (zio->io_error == 0 && dde->dde_repair_abd == NULL) 2451 dde->dde_repair_abd = zio->io_abd; 2452 else 2453 abd_free(zio->io_abd); 2454 mutex_exit(&pio->io_lock); 2455} 2456 2457static int 2458zio_ddt_read_start(zio_t *zio) 2459{ 2460 blkptr_t *bp = zio->io_bp; 2461 2462 ASSERT(BP_GET_DEDUP(bp)); 2463 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 2464 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2465 2466 if (zio->io_child_error[ZIO_CHILD_DDT]) { 2467 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2468 ddt_entry_t *dde = ddt_repair_start(ddt, bp); 2469 ddt_phys_t *ddp = dde->dde_phys; 2470 ddt_phys_t *ddp_self = ddt_phys_select(dde, bp); 2471 blkptr_t blk; 2472 2473 ASSERT(zio->io_vsd == NULL); 2474 zio->io_vsd = dde; 2475 2476 if (ddp_self == NULL) 2477 return (ZIO_PIPELINE_CONTINUE); 2478 2479 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { 2480 if (ddp->ddp_phys_birth == 0 || ddp == ddp_self) 2481 continue; 2482 ddt_bp_create(ddt->ddt_checksum, &dde->dde_key, ddp, 2483 &blk); 2484 zio_nowait(zio_read(zio, zio->io_spa, &blk, 2485 abd_alloc_for_io(zio->io_size, B_TRUE), 2486 zio->io_size, zio_ddt_child_read_done, dde, 2487 zio->io_priority, ZIO_DDT_CHILD_FLAGS(zio) | 2488 ZIO_FLAG_DONT_PROPAGATE, &zio->io_bookmark)); 2489 } 2490 return (ZIO_PIPELINE_CONTINUE); 2491 } 2492 2493 zio_nowait(zio_read(zio, zio->io_spa, bp, 2494 zio->io_abd, zio->io_size, NULL, NULL, zio->io_priority, 2495 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark)); 2496 2497 return (ZIO_PIPELINE_CONTINUE); 2498} 2499 2500static int 2501zio_ddt_read_done(zio_t *zio) 2502{ 2503 blkptr_t *bp = zio->io_bp; 2504 2505 if (zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE)) 2506 return (ZIO_PIPELINE_STOP); 2507 2508 ASSERT(BP_GET_DEDUP(bp)); 2509 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 2510 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2511 2512 if (zio->io_child_error[ZIO_CHILD_DDT]) { 2513 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2514 ddt_entry_t *dde = zio->io_vsd; 2515 if (ddt == NULL) { 2516 ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE); 2517 return (ZIO_PIPELINE_CONTINUE); 2518 } 2519 if (dde == NULL) { 2520 zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1; 2521 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 2522 return (ZIO_PIPELINE_STOP); 2523 } 2524 if (dde->dde_repair_abd != NULL) { 2525 abd_copy(zio->io_abd, dde->dde_repair_abd, 2526 zio->io_size); 2527 zio->io_child_error[ZIO_CHILD_DDT] = 0; 2528 } 2529 ddt_repair_done(ddt, dde); 2530 zio->io_vsd = NULL; 2531 } 2532 2533 ASSERT(zio->io_vsd == NULL); 2534 2535 return (ZIO_PIPELINE_CONTINUE); 2536} 2537 2538static boolean_t 2539zio_ddt_collision(zio_t *zio, ddt_t *ddt, ddt_entry_t *dde) 2540{ 2541 spa_t *spa = zio->io_spa; 2542 boolean_t do_raw = (zio->io_flags & ZIO_FLAG_RAW); 2543 2544 /* We should never get a raw, override zio */ 2545 ASSERT(!(zio->io_bp_override && do_raw)); 2546 2547 /* 2548 * Note: we compare the original data, not the transformed data, 2549 * because when zio->io_bp is an override bp, we will not have 2550 * pushed the I/O transforms. That's an important optimization 2551 * because otherwise we'd compress/encrypt all dmu_sync() data twice. 2552 */ 2553 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 2554 zio_t *lio = dde->dde_lead_zio[p]; 2555 2556 if (lio != NULL) { 2557 return (lio->io_orig_size != zio->io_orig_size || 2558 abd_cmp(zio->io_orig_abd, lio->io_orig_abd, 2559 zio->io_orig_size) != 0); 2560 } 2561 } 2562 2563 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 2564 ddt_phys_t *ddp = &dde->dde_phys[p]; 2565 2566 if (ddp->ddp_phys_birth != 0) { 2567 arc_buf_t *abuf = NULL; 2568 arc_flags_t aflags = ARC_FLAG_WAIT; 2569 int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE; 2570 blkptr_t blk = *zio->io_bp; 2571 int error; 2572 2573 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth); 2574 2575 ddt_exit(ddt); 2576 2577 /* 2578 * Intuitively, it would make more sense to compare 2579 * io_abd than io_orig_abd in the raw case since you 2580 * don't want to look at any transformations that have 2581 * happened to the data. However, for raw I/Os the 2582 * data will actually be the same in io_abd and 2583 * io_orig_abd, so all we have to do is issue this as 2584 * a raw ARC read. 2585 */ 2586 if (do_raw) { 2587 zio_flags |= ZIO_FLAG_RAW; 2588 ASSERT3U(zio->io_size, ==, zio->io_orig_size); 2589 ASSERT0(abd_cmp(zio->io_abd, zio->io_orig_abd, 2590 zio->io_size)); 2591 ASSERT3P(zio->io_transform_stack, ==, NULL); 2592 } 2593 2594 error = arc_read(NULL, spa, &blk, 2595 arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ, 2596 zio_flags, &aflags, &zio->io_bookmark); 2597 2598 if (error == 0) { 2599 if (arc_buf_size(abuf) != zio->io_orig_size || 2600 abd_cmp_buf(zio->io_orig_abd, abuf->b_data, 2601 zio->io_orig_size) != 0) 2602 error = SET_ERROR(EEXIST); 2603 arc_buf_destroy(abuf, &abuf); 2604 } 2605 2606 ddt_enter(ddt); 2607 return (error != 0); 2608 } 2609 } 2610 2611 return (B_FALSE); 2612} 2613 2614static void 2615zio_ddt_child_write_ready(zio_t *zio) 2616{ 2617 int p = zio->io_prop.zp_copies; 2618 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 2619 ddt_entry_t *dde = zio->io_private; 2620 ddt_phys_t *ddp = &dde->dde_phys[p]; 2621 zio_t *pio; 2622 2623 if (zio->io_error) 2624 return; 2625 2626 ddt_enter(ddt); 2627 2628 ASSERT(dde->dde_lead_zio[p] == zio); 2629 2630 ddt_phys_fill(ddp, zio->io_bp); 2631 2632 zio_link_t *zl = NULL; 2633 while ((pio = zio_walk_parents(zio, &zl)) != NULL) 2634 ddt_bp_fill(ddp, pio->io_bp, zio->io_txg); 2635 2636 ddt_exit(ddt); 2637} 2638 2639static void 2640zio_ddt_child_write_done(zio_t *zio) 2641{ 2642 int p = zio->io_prop.zp_copies; 2643 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 2644 ddt_entry_t *dde = zio->io_private; 2645 ddt_phys_t *ddp = &dde->dde_phys[p]; 2646 2647 ddt_enter(ddt); 2648 2649 ASSERT(ddp->ddp_refcnt == 0); 2650 ASSERT(dde->dde_lead_zio[p] == zio); 2651 dde->dde_lead_zio[p] = NULL; 2652 2653 if (zio->io_error == 0) { 2654 zio_link_t *zl = NULL; 2655 while (zio_walk_parents(zio, &zl) != NULL) 2656 ddt_phys_addref(ddp); 2657 } else { 2658 ddt_phys_clear(ddp); 2659 } 2660 2661 ddt_exit(ddt); 2662} 2663 2664static void 2665zio_ddt_ditto_write_done(zio_t *zio) 2666{ 2667 int p = DDT_PHYS_DITTO; 2668 zio_prop_t *zp = &zio->io_prop; 2669 blkptr_t *bp = zio->io_bp; 2670 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2671 ddt_entry_t *dde = zio->io_private; 2672 ddt_phys_t *ddp = &dde->dde_phys[p]; 2673 ddt_key_t *ddk = &dde->dde_key; 2674 2675 ddt_enter(ddt); 2676 2677 ASSERT(ddp->ddp_refcnt == 0); 2678 ASSERT(dde->dde_lead_zio[p] == zio); 2679 dde->dde_lead_zio[p] = NULL; 2680 2681 if (zio->io_error == 0) { 2682 ASSERT(ZIO_CHECKSUM_EQUAL(bp->blk_cksum, ddk->ddk_cksum)); 2683 ASSERT(zp->zp_copies < SPA_DVAS_PER_BP); 2684 ASSERT(zp->zp_copies == BP_GET_NDVAS(bp) - BP_IS_GANG(bp)); 2685 if (ddp->ddp_phys_birth != 0) 2686 ddt_phys_free(ddt, ddk, ddp, zio->io_txg); 2687 ddt_phys_fill(ddp, bp); 2688 } 2689 2690 ddt_exit(ddt); 2691} 2692 2693static int 2694zio_ddt_write(zio_t *zio) 2695{ 2696 spa_t *spa = zio->io_spa; 2697 blkptr_t *bp = zio->io_bp; 2698 uint64_t txg = zio->io_txg; 2699 zio_prop_t *zp = &zio->io_prop; 2700 int p = zp->zp_copies; 2701 int ditto_copies; 2702 zio_t *cio = NULL; 2703 zio_t *dio = NULL; 2704 ddt_t *ddt = ddt_select(spa, bp); 2705 ddt_entry_t *dde; 2706 ddt_phys_t *ddp; 2707 2708 ASSERT(BP_GET_DEDUP(bp)); 2709 ASSERT(BP_GET_CHECKSUM(bp) == zp->zp_checksum); 2710 ASSERT(BP_IS_HOLE(bp) || zio->io_bp_override); 2711 ASSERT(!(zio->io_bp_override && (zio->io_flags & ZIO_FLAG_RAW))); 2712 2713 ddt_enter(ddt); 2714 dde = ddt_lookup(ddt, bp, B_TRUE); 2715 ddp = &dde->dde_phys[p]; 2716 2717 if (zp->zp_dedup_verify && zio_ddt_collision(zio, ddt, dde)) { 2718 /* 2719 * If we're using a weak checksum, upgrade to a strong checksum 2720 * and try again. If we're already using a strong checksum, 2721 * we can't resolve it, so just convert to an ordinary write. 2722 * (And automatically e-mail a paper to Nature?) 2723 */ 2724 if (!(zio_checksum_table[zp->zp_checksum].ci_flags & 2725 ZCHECKSUM_FLAG_DEDUP)) { 2726 zp->zp_checksum = spa_dedup_checksum(spa); 2727 zio_pop_transforms(zio); 2728 zio->io_stage = ZIO_STAGE_OPEN; 2729 BP_ZERO(bp); 2730 } else { 2731 zp->zp_dedup = B_FALSE; 2732 BP_SET_DEDUP(bp, B_FALSE); 2733 } 2734 ASSERT(!BP_GET_DEDUP(bp)); 2735 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2736 ddt_exit(ddt); 2737 return (ZIO_PIPELINE_CONTINUE); 2738 } 2739 2740 ditto_copies = ddt_ditto_copies_needed(ddt, dde, ddp); 2741 ASSERT(ditto_copies < SPA_DVAS_PER_BP); 2742 2743 if (ditto_copies > ddt_ditto_copies_present(dde) && 2744 dde->dde_lead_zio[DDT_PHYS_DITTO] == NULL) { 2745 zio_prop_t czp = *zp; 2746 2747 czp.zp_copies = ditto_copies; 2748 2749 /* 2750 * If we arrived here with an override bp, we won't have run 2751 * the transform stack, so we won't have the data we need to 2752 * generate a child i/o. So, toss the override bp and restart. 2753 * This is safe, because using the override bp is just an 2754 * optimization; and it's rare, so the cost doesn't matter. 2755 */ 2756 if (zio->io_bp_override) { 2757 zio_pop_transforms(zio); 2758 zio->io_stage = ZIO_STAGE_OPEN; 2759 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2760 zio->io_bp_override = NULL; 2761 BP_ZERO(bp); 2762 ddt_exit(ddt); 2763 return (ZIO_PIPELINE_CONTINUE); 2764 } 2765 2766 dio = zio_write(zio, spa, txg, bp, zio->io_orig_abd, 2767 zio->io_orig_size, zio->io_orig_size, &czp, NULL, NULL, 2768 NULL, zio_ddt_ditto_write_done, dde, zio->io_priority, 2769 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2770 2771 zio_push_transform(dio, zio->io_abd, zio->io_size, 0, NULL); 2772 dde->dde_lead_zio[DDT_PHYS_DITTO] = dio; 2773 } 2774 2775 if (ddp->ddp_phys_birth != 0 || dde->dde_lead_zio[p] != NULL) { 2776 if (ddp->ddp_phys_birth != 0) 2777 ddt_bp_fill(ddp, bp, txg); 2778 if (dde->dde_lead_zio[p] != NULL) 2779 zio_add_child(zio, dde->dde_lead_zio[p]); 2780 else 2781 ddt_phys_addref(ddp); 2782 } else if (zio->io_bp_override) { 2783 ASSERT(bp->blk_birth == txg); 2784 ASSERT(BP_EQUAL(bp, zio->io_bp_override)); 2785 ddt_phys_fill(ddp, bp); 2786 ddt_phys_addref(ddp); 2787 } else { 2788 cio = zio_write(zio, spa, txg, bp, zio->io_orig_abd, 2789 zio->io_orig_size, zio->io_orig_size, zp, 2790 zio_ddt_child_write_ready, NULL, NULL, 2791 zio_ddt_child_write_done, dde, zio->io_priority, 2792 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2793 2794 zio_push_transform(cio, zio->io_abd, zio->io_size, 0, NULL); 2795 dde->dde_lead_zio[p] = cio; 2796 } 2797 2798 ddt_exit(ddt); 2799 2800 if (cio) 2801 zio_nowait(cio); 2802 if (dio) 2803 zio_nowait(dio); 2804 2805 return (ZIO_PIPELINE_CONTINUE); 2806} 2807 2808ddt_entry_t *freedde; /* for debugging */ 2809 2810static int 2811zio_ddt_free(zio_t *zio) 2812{ 2813 spa_t *spa = zio->io_spa; 2814 blkptr_t *bp = zio->io_bp; 2815 ddt_t *ddt = ddt_select(spa, bp); 2816 ddt_entry_t *dde; 2817 ddt_phys_t *ddp; 2818 2819 ASSERT(BP_GET_DEDUP(bp)); 2820 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2821 2822 ddt_enter(ddt); 2823 freedde = dde = ddt_lookup(ddt, bp, B_TRUE); 2824 ddp = ddt_phys_select(dde, bp); 2825 ddt_phys_decref(ddp); 2826 ddt_exit(ddt); 2827 2828 return (ZIO_PIPELINE_CONTINUE); 2829} 2830 2831/* 2832 * ========================================================================== 2833 * Allocate and free blocks 2834 * ========================================================================== 2835 */ 2836 2837static zio_t * 2838zio_io_to_allocate(spa_t *spa) 2839{ 2840 zio_t *zio; 2841 2842 ASSERT(MUTEX_HELD(&spa->spa_alloc_lock)); 2843 2844 zio = avl_first(&spa->spa_alloc_tree); 2845 if (zio == NULL) 2846 return (NULL); 2847 2848 ASSERT(IO_IS_ALLOCATING(zio)); 2849 2850 /* 2851 * Try to place a reservation for this zio. If we're unable to 2852 * reserve then we throttle. 2853 */ 2854 if (!metaslab_class_throttle_reserve(spa_normal_class(spa), 2855 zio->io_prop.zp_copies, zio, 0)) { 2856 return (NULL); 2857 } 2858 2859 avl_remove(&spa->spa_alloc_tree, zio); 2860 ASSERT3U(zio->io_stage, <, ZIO_STAGE_DVA_ALLOCATE); 2861 2862 return (zio); 2863} 2864 2865static int 2866zio_dva_throttle(zio_t *zio) 2867{ 2868 spa_t *spa = zio->io_spa; 2869 zio_t *nio; 2870 2871 if (zio->io_priority == ZIO_PRIORITY_SYNC_WRITE || 2872 !spa_normal_class(zio->io_spa)->mc_alloc_throttle_enabled || 2873 zio->io_child_type == ZIO_CHILD_GANG || 2874 zio->io_flags & ZIO_FLAG_NODATA) { 2875 return (ZIO_PIPELINE_CONTINUE); 2876 } 2877 2878 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2879 2880 ASSERT3U(zio->io_queued_timestamp, >, 0); 2881 ASSERT(zio->io_stage == ZIO_STAGE_DVA_THROTTLE); 2882 2883 mutex_enter(&spa->spa_alloc_lock); 2884 2885 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 2886 avl_add(&spa->spa_alloc_tree, zio); 2887 2888 nio = zio_io_to_allocate(zio->io_spa); 2889 mutex_exit(&spa->spa_alloc_lock); 2890 2891 if (nio == zio) 2892 return (ZIO_PIPELINE_CONTINUE); 2893 2894 if (nio != NULL) { 2895 ASSERT(nio->io_stage == ZIO_STAGE_DVA_THROTTLE); 2896 /* 2897 * We are passing control to a new zio so make sure that 2898 * it is processed by a different thread. We do this to 2899 * avoid stack overflows that can occur when parents are 2900 * throttled and children are making progress. We allow 2901 * it to go to the head of the taskq since it's already 2902 * been waiting. 2903 */ 2904 zio_taskq_dispatch(nio, ZIO_TASKQ_ISSUE, B_TRUE); 2905 } 2906 return (ZIO_PIPELINE_STOP); 2907} 2908 2909void 2910zio_allocate_dispatch(spa_t *spa) 2911{ 2912 zio_t *zio; 2913 2914 mutex_enter(&spa->spa_alloc_lock); 2915 zio = zio_io_to_allocate(spa); 2916 mutex_exit(&spa->spa_alloc_lock); 2917 if (zio == NULL) 2918 return; 2919 2920 ASSERT3U(zio->io_stage, ==, ZIO_STAGE_DVA_THROTTLE); 2921 ASSERT0(zio->io_error); 2922 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_TRUE); 2923} 2924 2925static int 2926zio_dva_allocate(zio_t *zio) 2927{ 2928 spa_t *spa = zio->io_spa; 2929 metaslab_class_t *mc = spa_normal_class(spa); 2930 blkptr_t *bp = zio->io_bp; 2931 int error; 2932 int flags = 0; 2933 2934 if (zio->io_gang_leader == NULL) { 2935 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2936 zio->io_gang_leader = zio; 2937 } 2938 2939 ASSERT(BP_IS_HOLE(bp)); 2940 ASSERT0(BP_GET_NDVAS(bp)); 2941 ASSERT3U(zio->io_prop.zp_copies, >, 0); 2942 ASSERT3U(zio->io_prop.zp_copies, <=, spa_max_replication(spa)); 2943 ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp)); 2944 2945 if (zio->io_flags & ZIO_FLAG_NODATA) { 2946 flags |= METASLAB_DONT_THROTTLE; 2947 } 2948 if (zio->io_flags & ZIO_FLAG_GANG_CHILD) { 2949 flags |= METASLAB_GANG_CHILD; 2950 } 2951 if (zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE) { 2952 flags |= METASLAB_ASYNC_ALLOC; 2953 } 2954 2955 error = metaslab_alloc(spa, mc, zio->io_size, bp, 2956 zio->io_prop.zp_copies, zio->io_txg, NULL, flags, 2957 &zio->io_alloc_list, zio); 2958 2959 if (error != 0) { 2960 spa_dbgmsg(spa, "%s: metaslab allocation failure: zio %p, " 2961 "size %llu, error %d", spa_name(spa), zio, zio->io_size, 2962 error); 2963 if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE) 2964 return (zio_write_gang_block(zio)); 2965 zio->io_error = error; 2966 } 2967 2968 return (ZIO_PIPELINE_CONTINUE); 2969} 2970 2971static int 2972zio_dva_free(zio_t *zio) 2973{ 2974 metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE); 2975 2976 return (ZIO_PIPELINE_CONTINUE); 2977} 2978 2979static int 2980zio_dva_claim(zio_t *zio) 2981{ 2982 int error; 2983 2984 error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg); 2985 if (error) 2986 zio->io_error = error; 2987 2988 return (ZIO_PIPELINE_CONTINUE); 2989} 2990 2991/* 2992 * Undo an allocation. This is used by zio_done() when an I/O fails 2993 * and we want to give back the block we just allocated. 2994 * This handles both normal blocks and gang blocks. 2995 */ 2996static void 2997zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp) 2998{ 2999 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp)); 3000 ASSERT(zio->io_bp_override == NULL); 3001 3002 if (!BP_IS_HOLE(bp)) 3003 metaslab_free(zio->io_spa, bp, bp->blk_birth, B_TRUE); 3004 3005 if (gn != NULL) { 3006 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 3007 zio_dva_unallocate(zio, gn->gn_child[g], 3008 &gn->gn_gbh->zg_blkptr[g]); 3009 } 3010 } 3011} 3012 3013/* 3014 * Try to allocate an intent log block. Return 0 on success, errno on failure. 3015 */ 3016int 3017zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp, blkptr_t *old_bp, 3018 uint64_t size, boolean_t *slog) 3019{ 3020 int error = 1; 3021 zio_alloc_list_t io_alloc_list; 3022 3023 ASSERT(txg > spa_syncing_txg(spa)); 3024 3025 metaslab_trace_init(&io_alloc_list); 3026 error = metaslab_alloc(spa, spa_log_class(spa), size, new_bp, 1, 3027 txg, old_bp, METASLAB_HINTBP_AVOID, &io_alloc_list, NULL); 3028 if (error == 0) { 3029 *slog = TRUE; 3030 } else { 3031 error = metaslab_alloc(spa, spa_normal_class(spa), size, 3032 new_bp, 1, txg, old_bp, METASLAB_HINTBP_AVOID, 3033 &io_alloc_list, NULL); 3034 if (error == 0) 3035 *slog = FALSE; 3036 } 3037 metaslab_trace_fini(&io_alloc_list); 3038 3039 if (error == 0) { 3040 BP_SET_LSIZE(new_bp, size); 3041 BP_SET_PSIZE(new_bp, size); 3042 BP_SET_COMPRESS(new_bp, ZIO_COMPRESS_OFF); 3043 BP_SET_CHECKSUM(new_bp, 3044 spa_version(spa) >= SPA_VERSION_SLIM_ZIL 3045 ? ZIO_CHECKSUM_ZILOG2 : ZIO_CHECKSUM_ZILOG); 3046 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG); 3047 BP_SET_LEVEL(new_bp, 0); 3048 BP_SET_DEDUP(new_bp, 0); 3049 BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER); 3050 } else { 3051 zfs_dbgmsg("%s: zil block allocation failure: " 3052 "size %llu, error %d", spa_name(spa), size, error); 3053 } 3054 3055 return (error); 3056} 3057 3058/* 3059 * Free an intent log block. 3060 */ 3061void 3062zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp) 3063{ 3064 ASSERT(BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG); 3065 ASSERT(!BP_IS_GANG(bp)); 3066 3067 zio_free(spa, txg, bp); 3068} 3069 3070/* 3071 * ========================================================================== 3072 * Read, write and delete to physical devices 3073 * ========================================================================== 3074 */ 3075 3076 3077/* 3078 * Issue an I/O to the underlying vdev. Typically the issue pipeline 3079 * stops after this stage and will resume upon I/O completion. 3080 * However, there are instances where the vdev layer may need to 3081 * continue the pipeline when an I/O was not issued. Since the I/O 3082 * that was sent to the vdev layer might be different than the one 3083 * currently active in the pipeline (see vdev_queue_io()), we explicitly 3084 * force the underlying vdev layers to call either zio_execute() or 3085 * zio_interrupt() to ensure that the pipeline continues with the correct I/O. 3086 */ 3087static int 3088zio_vdev_io_start(zio_t *zio) 3089{ 3090 vdev_t *vd = zio->io_vd; 3091 uint64_t align; 3092 spa_t *spa = zio->io_spa; 3093 int ret; 3094 3095 ASSERT(zio->io_error == 0); 3096 ASSERT(zio->io_child_error[ZIO_CHILD_VDEV] == 0); 3097 3098 if (vd == NULL) { 3099 if (!(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 3100 spa_config_enter(spa, SCL_ZIO, zio, RW_READER); 3101 3102 /* 3103 * The mirror_ops handle multiple DVAs in a single BP. 3104 */ 3105 vdev_mirror_ops.vdev_op_io_start(zio); 3106 return (ZIO_PIPELINE_STOP); 3107 } 3108 3109 if (vd->vdev_ops->vdev_op_leaf && zio->io_type == ZIO_TYPE_FREE && 3110 zio->io_priority == ZIO_PRIORITY_NOW) { 3111 trim_map_free(vd, zio->io_offset, zio->io_size, zio->io_txg); 3112 return (ZIO_PIPELINE_CONTINUE); 3113 } 3114 3115 ASSERT3P(zio->io_logical, !=, zio); 3116 3117 /* 3118 * We keep track of time-sensitive I/Os so that the scan thread 3119 * can quickly react to certain workloads. In particular, we care 3120 * about non-scrubbing, top-level reads and writes with the following 3121 * characteristics: 3122 * - synchronous writes of user data to non-slog devices 3123 * - any reads of user data 3124 * When these conditions are met, adjust the timestamp of spa_last_io 3125 * which allows the scan thread to adjust its workload accordingly. 3126 */ 3127 if (!(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && zio->io_bp != NULL && 3128 vd == vd->vdev_top && !vd->vdev_islog && 3129 zio->io_bookmark.zb_objset != DMU_META_OBJSET && 3130 zio->io_txg != spa_syncing_txg(spa)) { 3131 uint64_t old = spa->spa_last_io; 3132 uint64_t new = ddi_get_lbolt64(); 3133 if (old != new) 3134 (void) atomic_cas_64(&spa->spa_last_io, old, new); 3135 } 3136 3137 align = 1ULL << vd->vdev_top->vdev_ashift; 3138 3139 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL) && 3140 P2PHASE(zio->io_size, align) != 0) { 3141 /* Transform logical writes to be a full physical block size. */ 3142 uint64_t asize = P2ROUNDUP(zio->io_size, align); 3143 abd_t *abuf = NULL; 3144 if (zio->io_type == ZIO_TYPE_READ || 3145 zio->io_type == ZIO_TYPE_WRITE) 3146 abuf = abd_alloc_sametype(zio->io_abd, asize); 3147 ASSERT(vd == vd->vdev_top); 3148 if (zio->io_type == ZIO_TYPE_WRITE) { 3149 abd_copy(abuf, zio->io_abd, zio->io_size); 3150 abd_zero_off(abuf, zio->io_size, asize - zio->io_size); 3151 } 3152 zio_push_transform(zio, abuf, asize, abuf ? asize : 0, 3153 zio_subblock); 3154 } 3155 3156 /* 3157 * If this is not a physical io, make sure that it is properly aligned 3158 * before proceeding. 3159 */ 3160 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL)) { 3161 ASSERT0(P2PHASE(zio->io_offset, align)); 3162 ASSERT0(P2PHASE(zio->io_size, align)); 3163 } else { 3164 /* 3165 * For the physical io we allow alignment 3166 * to a logical block size. 3167 */ 3168 uint64_t log_align = 3169 1ULL << vd->vdev_top->vdev_logical_ashift; 3170 ASSERT0(P2PHASE(zio->io_offset, log_align)); 3171 ASSERT0(P2PHASE(zio->io_size, log_align)); 3172 } 3173 3174 VERIFY(zio->io_type == ZIO_TYPE_READ || spa_writeable(spa)); 3175 3176 /* 3177 * If this is a repair I/O, and there's no self-healing involved -- 3178 * that is, we're just resilvering what we expect to resilver -- 3179 * then don't do the I/O unless zio's txg is actually in vd's DTL. 3180 * This prevents spurious resilvering with nested replication. 3181 * For example, given a mirror of mirrors, (A+B)+(C+D), if only 3182 * A is out of date, we'll read from C+D, then use the data to 3183 * resilver A+B -- but we don't actually want to resilver B, just A. 3184 * The top-level mirror has no way to know this, so instead we just 3185 * discard unnecessary repairs as we work our way down the vdev tree. 3186 * The same logic applies to any form of nested replication: 3187 * ditto + mirror, RAID-Z + replacing, etc. This covers them all. 3188 */ 3189 if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) && 3190 !(zio->io_flags & ZIO_FLAG_SELF_HEAL) && 3191 zio->io_txg != 0 && /* not a delegated i/o */ 3192 !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) { 3193 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 3194 zio_vdev_io_bypass(zio); 3195 return (ZIO_PIPELINE_CONTINUE); 3196 } 3197 3198 if (vd->vdev_ops->vdev_op_leaf) { 3199 switch (zio->io_type) { 3200 case ZIO_TYPE_READ: 3201 if (vdev_cache_read(zio)) 3202 return (ZIO_PIPELINE_CONTINUE); 3203 /* FALLTHROUGH */ 3204 case ZIO_TYPE_WRITE: 3205 case ZIO_TYPE_FREE: 3206 if ((zio = vdev_queue_io(zio)) == NULL) 3207 return (ZIO_PIPELINE_STOP); 3208 3209 if (!vdev_accessible(vd, zio)) { 3210 zio->io_error = SET_ERROR(ENXIO); 3211 zio_interrupt(zio); 3212 return (ZIO_PIPELINE_STOP); 3213 } 3214 break; 3215 } 3216 /* 3217 * Note that we ignore repair writes for TRIM because they can 3218 * conflict with normal writes. This isn't an issue because, by 3219 * definition, we only repair blocks that aren't freed. 3220 */ 3221 if (zio->io_type == ZIO_TYPE_WRITE && 3222 !(zio->io_flags & ZIO_FLAG_IO_REPAIR) && 3223 !trim_map_write_start(zio)) 3224 return (ZIO_PIPELINE_STOP); 3225 } 3226 3227 vd->vdev_ops->vdev_op_io_start(zio); 3228 return (ZIO_PIPELINE_STOP); 3229} 3230 3231static int 3232zio_vdev_io_done(zio_t *zio) 3233{ 3234 vdev_t *vd = zio->io_vd; 3235 vdev_ops_t *ops = vd ? vd->vdev_ops : &vdev_mirror_ops; 3236 boolean_t unexpected_error = B_FALSE; 3237 3238 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 3239 return (ZIO_PIPELINE_STOP); 3240 3241 ASSERT(zio->io_type == ZIO_TYPE_READ || 3242 zio->io_type == ZIO_TYPE_WRITE || zio->io_type == ZIO_TYPE_FREE); 3243 3244 if (vd != NULL && vd->vdev_ops->vdev_op_leaf && 3245 (zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE || 3246 zio->io_type == ZIO_TYPE_FREE)) { 3247 3248 if (zio->io_type == ZIO_TYPE_WRITE && 3249 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) 3250 trim_map_write_done(zio); 3251 3252 vdev_queue_io_done(zio); 3253 3254 if (zio->io_type == ZIO_TYPE_WRITE) 3255 vdev_cache_write(zio); 3256 3257 if (zio_injection_enabled && zio->io_error == 0) 3258 zio->io_error = zio_handle_device_injection(vd, 3259 zio, EIO); 3260 3261 if (zio_injection_enabled && zio->io_error == 0) 3262 zio->io_error = zio_handle_label_injection(zio, EIO); 3263 3264 if (zio->io_error) { 3265 if (zio->io_error == ENOTSUP && 3266 zio->io_type == ZIO_TYPE_FREE) { 3267 /* Not all devices support TRIM. */ 3268 } else if (!vdev_accessible(vd, zio)) { 3269 zio->io_error = SET_ERROR(ENXIO); 3270 } else { 3271 unexpected_error = B_TRUE; 3272 } 3273 } 3274 } 3275 3276 ops->vdev_op_io_done(zio); 3277 3278 if (unexpected_error) 3279 VERIFY(vdev_probe(vd, zio) == NULL); 3280 3281 return (ZIO_PIPELINE_CONTINUE); 3282} 3283 3284/* 3285 * For non-raidz ZIOs, we can just copy aside the bad data read from the 3286 * disk, and use that to finish the checksum ereport later. 3287 */ 3288static void 3289zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr, 3290 const void *good_buf) 3291{ 3292 /* no processing needed */ 3293 zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE); 3294} 3295 3296/*ARGSUSED*/ 3297void 3298zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *ignored) 3299{ 3300 void *buf = zio_buf_alloc(zio->io_size); 3301 3302 abd_copy_to_buf(buf, zio->io_abd, zio->io_size); 3303 3304 zcr->zcr_cbinfo = zio->io_size; 3305 zcr->zcr_cbdata = buf; 3306 zcr->zcr_finish = zio_vsd_default_cksum_finish; 3307 zcr->zcr_free = zio_buf_free; 3308} 3309 3310static int 3311zio_vdev_io_assess(zio_t *zio) 3312{ 3313 vdev_t *vd = zio->io_vd; 3314 3315 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 3316 return (ZIO_PIPELINE_STOP); 3317 3318 if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 3319 spa_config_exit(zio->io_spa, SCL_ZIO, zio); 3320 3321 if (zio->io_vsd != NULL) { 3322 zio->io_vsd_ops->vsd_free(zio); 3323 zio->io_vsd = NULL; 3324 } 3325 3326 if (zio_injection_enabled && zio->io_error == 0) 3327 zio->io_error = zio_handle_fault_injection(zio, EIO); 3328 3329 if (zio->io_type == ZIO_TYPE_FREE && 3330 zio->io_priority != ZIO_PRIORITY_NOW) { 3331 switch (zio->io_error) { 3332 case 0: 3333 ZIO_TRIM_STAT_INCR(bytes, zio->io_size); 3334 ZIO_TRIM_STAT_BUMP(success); 3335 break; 3336 case EOPNOTSUPP: 3337 ZIO_TRIM_STAT_BUMP(unsupported); 3338 break; 3339 default: 3340 ZIO_TRIM_STAT_BUMP(failed); 3341 break; 3342 } 3343 } 3344 3345 /* 3346 * If the I/O failed, determine whether we should attempt to retry it. 3347 * 3348 * On retry, we cut in line in the issue queue, since we don't want 3349 * compression/checksumming/etc. work to prevent our (cheap) IO reissue. 3350 */ 3351 if (zio->io_error && vd == NULL && 3352 !(zio->io_flags & (ZIO_FLAG_DONT_RETRY | ZIO_FLAG_IO_RETRY))) { 3353 ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_QUEUE)); /* not a leaf */ 3354 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_BYPASS)); /* not a leaf */ 3355 zio->io_error = 0; 3356 zio->io_flags |= ZIO_FLAG_IO_RETRY | 3357 ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE; 3358 zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1; 3359 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, 3360 zio_requeue_io_start_cut_in_line); 3361 return (ZIO_PIPELINE_STOP); 3362 } 3363 3364 /* 3365 * If we got an error on a leaf device, convert it to ENXIO 3366 * if the device is not accessible at all. 3367 */ 3368 if (zio->io_error && vd != NULL && vd->vdev_ops->vdev_op_leaf && 3369 !vdev_accessible(vd, zio)) 3370 zio->io_error = SET_ERROR(ENXIO); 3371 3372 /* 3373 * If we can't write to an interior vdev (mirror or RAID-Z), 3374 * set vdev_cant_write so that we stop trying to allocate from it. 3375 */ 3376 if (zio->io_error == ENXIO && zio->io_type == ZIO_TYPE_WRITE && 3377 vd != NULL && !vd->vdev_ops->vdev_op_leaf) { 3378 vd->vdev_cant_write = B_TRUE; 3379 } 3380 3381 /* 3382 * If a cache flush returns ENOTSUP or ENOTTY, we know that no future 3383 * attempts will ever succeed. In this case we set a persistent bit so 3384 * that we don't bother with it in the future. 3385 */ 3386 if ((zio->io_error == ENOTSUP || zio->io_error == ENOTTY) && 3387 zio->io_type == ZIO_TYPE_IOCTL && 3388 zio->io_cmd == DKIOCFLUSHWRITECACHE && vd != NULL) 3389 vd->vdev_nowritecache = B_TRUE; 3390 3391 if (zio->io_error) 3392 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 3393 3394 if (vd != NULL && vd->vdev_ops->vdev_op_leaf && 3395 zio->io_physdone != NULL) { 3396 ASSERT(!(zio->io_flags & ZIO_FLAG_DELEGATED)); 3397 ASSERT(zio->io_child_type == ZIO_CHILD_VDEV); 3398 zio->io_physdone(zio->io_logical); 3399 } 3400 3401 return (ZIO_PIPELINE_CONTINUE); 3402} 3403 3404void 3405zio_vdev_io_reissue(zio_t *zio) 3406{ 3407 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 3408 ASSERT(zio->io_error == 0); 3409 3410 zio->io_stage >>= 1; 3411} 3412 3413void 3414zio_vdev_io_redone(zio_t *zio) 3415{ 3416 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE); 3417 3418 zio->io_stage >>= 1; 3419} 3420 3421void 3422zio_vdev_io_bypass(zio_t *zio) 3423{ 3424 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 3425 ASSERT(zio->io_error == 0); 3426 3427 zio->io_flags |= ZIO_FLAG_IO_BYPASS; 3428 zio->io_stage = ZIO_STAGE_VDEV_IO_ASSESS >> 1; 3429} 3430 3431/* 3432 * ========================================================================== 3433 * Generate and verify checksums 3434 * ========================================================================== 3435 */ 3436static int 3437zio_checksum_generate(zio_t *zio) 3438{ 3439 blkptr_t *bp = zio->io_bp; 3440 enum zio_checksum checksum; 3441 3442 if (bp == NULL) { 3443 /* 3444 * This is zio_write_phys(). 3445 * We're either generating a label checksum, or none at all. 3446 */ 3447 checksum = zio->io_prop.zp_checksum; 3448 3449 if (checksum == ZIO_CHECKSUM_OFF) 3450 return (ZIO_PIPELINE_CONTINUE); 3451 3452 ASSERT(checksum == ZIO_CHECKSUM_LABEL); 3453 } else { 3454 if (BP_IS_GANG(bp) && zio->io_child_type == ZIO_CHILD_GANG) { 3455 ASSERT(!IO_IS_ALLOCATING(zio)); 3456 checksum = ZIO_CHECKSUM_GANG_HEADER; 3457 } else { 3458 checksum = BP_GET_CHECKSUM(bp); 3459 } 3460 } 3461 3462 zio_checksum_compute(zio, checksum, zio->io_abd, zio->io_size); 3463 3464 return (ZIO_PIPELINE_CONTINUE); 3465} 3466 3467static int 3468zio_checksum_verify(zio_t *zio) 3469{ 3470 zio_bad_cksum_t info; 3471 blkptr_t *bp = zio->io_bp; 3472 int error; 3473 3474 ASSERT(zio->io_vd != NULL); 3475 3476 if (bp == NULL) { 3477 /* 3478 * This is zio_read_phys(). 3479 * We're either verifying a label checksum, or nothing at all. 3480 */ 3481 if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF) 3482 return (ZIO_PIPELINE_CONTINUE); 3483 3484 ASSERT(zio->io_prop.zp_checksum == ZIO_CHECKSUM_LABEL); 3485 } 3486 3487 if ((error = zio_checksum_error(zio, &info)) != 0) { 3488 zio->io_error = error; 3489 if (error == ECKSUM && 3490 !(zio->io_flags & ZIO_FLAG_SPECULATIVE)) { 3491 zfs_ereport_start_checksum(zio->io_spa, 3492 zio->io_vd, zio, zio->io_offset, 3493 zio->io_size, NULL, &info); 3494 } 3495 } 3496 3497 return (ZIO_PIPELINE_CONTINUE); 3498} 3499 3500/* 3501 * Called by RAID-Z to ensure we don't compute the checksum twice. 3502 */ 3503void 3504zio_checksum_verified(zio_t *zio) 3505{ 3506 zio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 3507} 3508 3509/* 3510 * ========================================================================== 3511 * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other. 3512 * An error of 0 indicates success. ENXIO indicates whole-device failure, 3513 * which may be transient (e.g. unplugged) or permament. ECKSUM and EIO 3514 * indicate errors that are specific to one I/O, and most likely permanent. 3515 * Any other error is presumed to be worse because we weren't expecting it. 3516 * ========================================================================== 3517 */ 3518int 3519zio_worst_error(int e1, int e2) 3520{ 3521 static int zio_error_rank[] = { 0, ENXIO, ECKSUM, EIO }; 3522 int r1, r2; 3523 3524 for (r1 = 0; r1 < sizeof (zio_error_rank) / sizeof (int); r1++) 3525 if (e1 == zio_error_rank[r1]) 3526 break; 3527 3528 for (r2 = 0; r2 < sizeof (zio_error_rank) / sizeof (int); r2++) 3529 if (e2 == zio_error_rank[r2]) 3530 break; 3531 3532 return (r1 > r2 ? e1 : e2); 3533} 3534 3535/* 3536 * ========================================================================== 3537 * I/O completion 3538 * ========================================================================== 3539 */ 3540static int 3541zio_ready(zio_t *zio) 3542{ 3543 blkptr_t *bp = zio->io_bp; 3544 zio_t *pio, *pio_next; 3545 zio_link_t *zl = NULL; 3546 3547 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 3548 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_READY)) 3549 return (ZIO_PIPELINE_STOP); 3550 3551 if (zio->io_ready) { 3552 ASSERT(IO_IS_ALLOCATING(zio)); 3553 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp) || 3554 (zio->io_flags & ZIO_FLAG_NOPWRITE)); 3555 ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0); 3556 3557 zio->io_ready(zio); 3558 } 3559 3560 if (bp != NULL && bp != &zio->io_bp_copy) 3561 zio->io_bp_copy = *bp; 3562 3563 if (zio->io_error != 0) { 3564 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 3565 3566 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 3567 ASSERT(IO_IS_ALLOCATING(zio)); 3568 ASSERT(zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 3569 /* 3570 * We were unable to allocate anything, unreserve and 3571 * issue the next I/O to allocate. 3572 */ 3573 metaslab_class_throttle_unreserve( 3574 spa_normal_class(zio->io_spa), 3575 zio->io_prop.zp_copies, zio); 3576 zio_allocate_dispatch(zio->io_spa); 3577 } 3578 } 3579 3580 mutex_enter(&zio->io_lock); 3581 zio->io_state[ZIO_WAIT_READY] = 1; 3582 pio = zio_walk_parents(zio, &zl); 3583 mutex_exit(&zio->io_lock); 3584 3585 /* 3586 * As we notify zio's parents, new parents could be added. 3587 * New parents go to the head of zio's io_parent_list, however, 3588 * so we will (correctly) not notify them. The remainder of zio's 3589 * io_parent_list, from 'pio_next' onward, cannot change because 3590 * all parents must wait for us to be done before they can be done. 3591 */ 3592 for (; pio != NULL; pio = pio_next) { 3593 pio_next = zio_walk_parents(zio, &zl); 3594 zio_notify_parent(pio, zio, ZIO_WAIT_READY); 3595 } 3596 3597 if (zio->io_flags & ZIO_FLAG_NODATA) { 3598 if (BP_IS_GANG(bp)) { 3599 zio->io_flags &= ~ZIO_FLAG_NODATA; 3600 } else { 3601 ASSERT((uintptr_t)zio->io_abd < SPA_MAXBLOCKSIZE); 3602 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 3603 } 3604 } 3605 3606 if (zio_injection_enabled && 3607 zio->io_spa->spa_syncing_txg == zio->io_txg) 3608 zio_handle_ignored_writes(zio); 3609 3610 return (ZIO_PIPELINE_CONTINUE); 3611} 3612 3613/* 3614 * Update the allocation throttle accounting. 3615 */ 3616static void 3617zio_dva_throttle_done(zio_t *zio) 3618{ 3619 zio_t *lio = zio->io_logical; 3620 zio_t *pio = zio_unique_parent(zio); 3621 vdev_t *vd = zio->io_vd; 3622 int flags = METASLAB_ASYNC_ALLOC; 3623 3624 ASSERT3P(zio->io_bp, !=, NULL); 3625 ASSERT3U(zio->io_type, ==, ZIO_TYPE_WRITE); 3626 ASSERT3U(zio->io_priority, ==, ZIO_PRIORITY_ASYNC_WRITE); 3627 ASSERT3U(zio->io_child_type, ==, ZIO_CHILD_VDEV); 3628 ASSERT(vd != NULL); 3629 ASSERT3P(vd, ==, vd->vdev_top); 3630 ASSERT(!(zio->io_flags & (ZIO_FLAG_IO_REPAIR | ZIO_FLAG_IO_RETRY))); 3631 ASSERT(zio->io_flags & ZIO_FLAG_IO_ALLOCATING); 3632 ASSERT(!(lio->io_flags & ZIO_FLAG_IO_REWRITE)); 3633 ASSERT(!(lio->io_orig_flags & ZIO_FLAG_NODATA)); 3634 3635 /* 3636 * Parents of gang children can have two flavors -- ones that 3637 * allocated the gang header (will have ZIO_FLAG_IO_REWRITE set) 3638 * and ones that allocated the constituent blocks. The allocation 3639 * throttle needs to know the allocating parent zio so we must find 3640 * it here. 3641 */ 3642 if (pio->io_child_type == ZIO_CHILD_GANG) { 3643 /* 3644 * If our parent is a rewrite gang child then our grandparent 3645 * would have been the one that performed the allocation. 3646 */ 3647 if (pio->io_flags & ZIO_FLAG_IO_REWRITE) 3648 pio = zio_unique_parent(pio); 3649 flags |= METASLAB_GANG_CHILD; 3650 } 3651 3652 ASSERT(IO_IS_ALLOCATING(pio)); 3653 ASSERT3P(zio, !=, zio->io_logical); 3654 ASSERT(zio->io_logical != NULL); 3655 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REPAIR)); 3656 ASSERT0(zio->io_flags & ZIO_FLAG_NOPWRITE); 3657 3658 mutex_enter(&pio->io_lock); 3659 metaslab_group_alloc_decrement(zio->io_spa, vd->vdev_id, pio, flags); 3660 mutex_exit(&pio->io_lock); 3661 3662 metaslab_class_throttle_unreserve(spa_normal_class(zio->io_spa), 3663 1, pio); 3664 3665 /* 3666 * Call into the pipeline to see if there is more work that 3667 * needs to be done. If there is work to be done it will be 3668 * dispatched to another taskq thread. 3669 */ 3670 zio_allocate_dispatch(zio->io_spa); 3671} 3672 3673static int 3674zio_done(zio_t *zio) 3675{ 3676 spa_t *spa = zio->io_spa; 3677 zio_t *lio = zio->io_logical; 3678 blkptr_t *bp = zio->io_bp; 3679 vdev_t *vd = zio->io_vd; 3680 uint64_t psize = zio->io_size; 3681 zio_t *pio, *pio_next; 3682 metaslab_class_t *mc = spa_normal_class(spa); 3683 zio_link_t *zl = NULL; 3684 3685 /* 3686 * If our children haven't all completed, 3687 * wait for them and then repeat this pipeline stage. 3688 */ 3689 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE) || 3690 zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE) || 3691 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE) || 3692 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_DONE)) 3693 return (ZIO_PIPELINE_STOP); 3694 3695 /* 3696 * If the allocation throttle is enabled, then update the accounting. 3697 * We only track child I/Os that are part of an allocating async 3698 * write. We must do this since the allocation is performed 3699 * by the logical I/O but the actual write is done by child I/Os. 3700 */ 3701 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING && 3702 zio->io_child_type == ZIO_CHILD_VDEV) { 3703 ASSERT(mc->mc_alloc_throttle_enabled); 3704 zio_dva_throttle_done(zio); 3705 } 3706 3707 /* 3708 * If the allocation throttle is enabled, verify that 3709 * we have decremented the refcounts for every I/O that was throttled. 3710 */ 3711 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 3712 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 3713 ASSERT(zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 3714 ASSERT(bp != NULL); 3715 metaslab_group_alloc_verify(spa, zio->io_bp, zio); 3716 VERIFY(refcount_not_held(&mc->mc_alloc_slots, zio)); 3717 } 3718 3719 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 3720 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 3721 ASSERT(zio->io_children[c][w] == 0); 3722 3723 if (bp != NULL && !BP_IS_EMBEDDED(bp)) { 3724 ASSERT(bp->blk_pad[0] == 0); 3725 ASSERT(bp->blk_pad[1] == 0); 3726 ASSERT(bcmp(bp, &zio->io_bp_copy, sizeof (blkptr_t)) == 0 || 3727 (bp == zio_unique_parent(zio)->io_bp)); 3728 if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(bp) && 3729 zio->io_bp_override == NULL && 3730 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) { 3731 ASSERT(!BP_SHOULD_BYTESWAP(bp)); 3732 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(bp)); 3733 ASSERT(BP_COUNT_GANG(bp) == 0 || 3734 (BP_COUNT_GANG(bp) == BP_GET_NDVAS(bp))); 3735 } 3736 if (zio->io_flags & ZIO_FLAG_NOPWRITE) 3737 VERIFY(BP_EQUAL(bp, &zio->io_bp_orig)); 3738 } 3739 3740 /* 3741 * If there were child vdev/gang/ddt errors, they apply to us now. 3742 */ 3743 zio_inherit_child_errors(zio, ZIO_CHILD_VDEV); 3744 zio_inherit_child_errors(zio, ZIO_CHILD_GANG); 3745 zio_inherit_child_errors(zio, ZIO_CHILD_DDT); 3746 3747 /* 3748 * If the I/O on the transformed data was successful, generate any 3749 * checksum reports now while we still have the transformed data. 3750 */ 3751 if (zio->io_error == 0) { 3752 while (zio->io_cksum_report != NULL) { 3753 zio_cksum_report_t *zcr = zio->io_cksum_report; 3754 uint64_t align = zcr->zcr_align; 3755 uint64_t asize = P2ROUNDUP(psize, align); 3756 char *abuf = NULL; 3757 abd_t *adata = zio->io_abd; 3758 3759 if (asize != psize) { 3760 adata = abd_alloc_linear(asize, B_TRUE); 3761 abd_copy(adata, zio->io_abd, psize); 3762 abd_zero_off(adata, psize, asize - psize); 3763 } 3764 3765 if (adata != NULL) 3766 abuf = abd_borrow_buf_copy(adata, asize); 3767 3768 zio->io_cksum_report = zcr->zcr_next; 3769 zcr->zcr_next = NULL; 3770 zcr->zcr_finish(zcr, abuf); 3771 zfs_ereport_free_checksum(zcr); 3772 3773 if (adata != NULL) 3774 abd_return_buf(adata, abuf, asize); 3775 3776 if (asize != psize) 3777 abd_free(adata); 3778 } 3779 } 3780 3781 zio_pop_transforms(zio); /* note: may set zio->io_error */ 3782 3783 vdev_stat_update(zio, psize); 3784 3785 if (zio->io_error) { 3786 /* 3787 * If this I/O is attached to a particular vdev, 3788 * generate an error message describing the I/O failure 3789 * at the block level. We ignore these errors if the 3790 * device is currently unavailable. 3791 */ 3792 if (zio->io_error != ECKSUM && vd != NULL && !vdev_is_dead(vd)) 3793 zfs_ereport_post(FM_EREPORT_ZFS_IO, spa, vd, zio, 0, 0); 3794 3795 if ((zio->io_error == EIO || !(zio->io_flags & 3796 (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) && 3797 zio == lio) { 3798 /* 3799 * For logical I/O requests, tell the SPA to log the 3800 * error and generate a logical data ereport. 3801 */ 3802 spa_log_error(spa, zio); 3803 zfs_ereport_post(FM_EREPORT_ZFS_DATA, spa, NULL, zio, 3804 0, 0); 3805 } 3806 } 3807 3808 if (zio->io_error && zio == lio) { 3809 /* 3810 * Determine whether zio should be reexecuted. This will 3811 * propagate all the way to the root via zio_notify_parent(). 3812 */ 3813 ASSERT(vd == NULL && bp != NULL); 3814 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3815 3816 if (IO_IS_ALLOCATING(zio) && 3817 !(zio->io_flags & ZIO_FLAG_CANFAIL)) { 3818 if (zio->io_error != ENOSPC) 3819 zio->io_reexecute |= ZIO_REEXECUTE_NOW; 3820 else 3821 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3822 } 3823 3824 if ((zio->io_type == ZIO_TYPE_READ || 3825 zio->io_type == ZIO_TYPE_FREE) && 3826 !(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && 3827 zio->io_error == ENXIO && 3828 spa_load_state(spa) == SPA_LOAD_NONE && 3829 spa_get_failmode(spa) != ZIO_FAILURE_MODE_CONTINUE) 3830 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3831 3832 if (!(zio->io_flags & ZIO_FLAG_CANFAIL) && !zio->io_reexecute) 3833 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3834 3835 /* 3836 * Here is a possibly good place to attempt to do 3837 * either combinatorial reconstruction or error correction 3838 * based on checksums. It also might be a good place 3839 * to send out preliminary ereports before we suspend 3840 * processing. 3841 */ 3842 } 3843 3844 /* 3845 * If there were logical child errors, they apply to us now. 3846 * We defer this until now to avoid conflating logical child 3847 * errors with errors that happened to the zio itself when 3848 * updating vdev stats and reporting FMA events above. 3849 */ 3850 zio_inherit_child_errors(zio, ZIO_CHILD_LOGICAL); 3851 3852 if ((zio->io_error || zio->io_reexecute) && 3853 IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio && 3854 !(zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE))) 3855 zio_dva_unallocate(zio, zio->io_gang_tree, bp); 3856 3857 zio_gang_tree_free(&zio->io_gang_tree); 3858 3859 /* 3860 * Godfather I/Os should never suspend. 3861 */ 3862 if ((zio->io_flags & ZIO_FLAG_GODFATHER) && 3863 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) 3864 zio->io_reexecute = 0; 3865 3866 if (zio->io_reexecute) { 3867 /* 3868 * This is a logical I/O that wants to reexecute. 3869 * 3870 * Reexecute is top-down. When an i/o fails, if it's not 3871 * the root, it simply notifies its parent and sticks around. 3872 * The parent, seeing that it still has children in zio_done(), 3873 * does the same. This percolates all the way up to the root. 3874 * The root i/o will reexecute or suspend the entire tree. 3875 * 3876 * This approach ensures that zio_reexecute() honors 3877 * all the original i/o dependency relationships, e.g. 3878 * parents not executing until children are ready. 3879 */ 3880 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3881 3882 zio->io_gang_leader = NULL; 3883 3884 mutex_enter(&zio->io_lock); 3885 zio->io_state[ZIO_WAIT_DONE] = 1; 3886 mutex_exit(&zio->io_lock); 3887 3888 /* 3889 * "The Godfather" I/O monitors its children but is 3890 * not a true parent to them. It will track them through 3891 * the pipeline but severs its ties whenever they get into 3892 * trouble (e.g. suspended). This allows "The Godfather" 3893 * I/O to return status without blocking. 3894 */ 3895 zl = NULL; 3896 for (pio = zio_walk_parents(zio, &zl); pio != NULL; 3897 pio = pio_next) { 3898 zio_link_t *remove_zl = zl; 3899 pio_next = zio_walk_parents(zio, &zl); 3900 3901 if ((pio->io_flags & ZIO_FLAG_GODFATHER) && 3902 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) { 3903 zio_remove_child(pio, zio, remove_zl); 3904 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3905 } 3906 } 3907 3908 if ((pio = zio_unique_parent(zio)) != NULL) { 3909 /* 3910 * We're not a root i/o, so there's nothing to do 3911 * but notify our parent. Don't propagate errors 3912 * upward since we haven't permanently failed yet. 3913 */ 3914 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 3915 zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE; 3916 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3917 } else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) { 3918 /* 3919 * We'd fail again if we reexecuted now, so suspend 3920 * until conditions improve (e.g. device comes online). 3921 */ 3922 zio_suspend(spa, zio); 3923 } else { 3924 /* 3925 * Reexecution is potentially a huge amount of work. 3926 * Hand it off to the otherwise-unused claim taskq. 3927 */ 3928#if defined(illumos) || !defined(_KERNEL) 3929 ASSERT(zio->io_tqent.tqent_next == NULL); 3930#else 3931 ASSERT(zio->io_tqent.tqent_task.ta_pending == 0); 3932#endif 3933 spa_taskq_dispatch_ent(spa, ZIO_TYPE_CLAIM, 3934 ZIO_TASKQ_ISSUE, (task_func_t *)zio_reexecute, zio, 3935 0, &zio->io_tqent); 3936 } 3937 return (ZIO_PIPELINE_STOP); 3938 } 3939 3940 ASSERT(zio->io_child_count == 0); 3941 ASSERT(zio->io_reexecute == 0); 3942 ASSERT(zio->io_error == 0 || (zio->io_flags & ZIO_FLAG_CANFAIL)); 3943 3944 /* 3945 * Report any checksum errors, since the I/O is complete. 3946 */ 3947 while (zio->io_cksum_report != NULL) { 3948 zio_cksum_report_t *zcr = zio->io_cksum_report; 3949 zio->io_cksum_report = zcr->zcr_next; 3950 zcr->zcr_next = NULL; 3951 zcr->zcr_finish(zcr, NULL); 3952 zfs_ereport_free_checksum(zcr); 3953 } 3954 3955 /* 3956 * It is the responsibility of the done callback to ensure that this 3957 * particular zio is no longer discoverable for adoption, and as 3958 * such, cannot acquire any new parents. 3959 */ 3960 if (zio->io_done) 3961 zio->io_done(zio); 3962 3963 mutex_enter(&zio->io_lock); 3964 zio->io_state[ZIO_WAIT_DONE] = 1; 3965 mutex_exit(&zio->io_lock); 3966 3967 zl = NULL; 3968 for (pio = zio_walk_parents(zio, &zl); pio != NULL; pio = pio_next) { 3969 zio_link_t *remove_zl = zl; 3970 pio_next = zio_walk_parents(zio, &zl); 3971 zio_remove_child(pio, zio, remove_zl); 3972 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3973 } 3974 3975 if (zio->io_waiter != NULL) { 3976 mutex_enter(&zio->io_lock); 3977 zio->io_executor = NULL; 3978 cv_broadcast(&zio->io_cv); 3979 mutex_exit(&zio->io_lock); 3980 } else { 3981 zio_destroy(zio); 3982 } 3983 3984 return (ZIO_PIPELINE_STOP); 3985} 3986 3987/* 3988 * ========================================================================== 3989 * I/O pipeline definition 3990 * ========================================================================== 3991 */ 3992static zio_pipe_stage_t *zio_pipeline[] = { 3993 NULL, 3994 zio_read_bp_init, 3995 zio_write_bp_init, 3996 zio_free_bp_init, 3997 zio_issue_async, 3998 zio_write_compress, 3999 zio_checksum_generate, 4000 zio_nop_write, 4001 zio_ddt_read_start, 4002 zio_ddt_read_done, 4003 zio_ddt_write, 4004 zio_ddt_free, 4005 zio_gang_assemble, 4006 zio_gang_issue, 4007 zio_dva_throttle, 4008 zio_dva_allocate, 4009 zio_dva_free, 4010 zio_dva_claim, 4011 zio_ready, 4012 zio_vdev_io_start, 4013 zio_vdev_io_done, 4014 zio_vdev_io_assess, 4015 zio_checksum_verify, 4016 zio_done 4017}; 4018 4019 4020 4021 4022/* 4023 * Compare two zbookmark_phys_t's to see which we would reach first in a 4024 * pre-order traversal of the object tree. 4025 * 4026 * This is simple in every case aside from the meta-dnode object. For all other 4027 * objects, we traverse them in order (object 1 before object 2, and so on). 4028 * However, all of these objects are traversed while traversing object 0, since 4029 * the data it points to is the list of objects. Thus, we need to convert to a 4030 * canonical representation so we can compare meta-dnode bookmarks to 4031 * non-meta-dnode bookmarks. 4032 * 4033 * We do this by calculating "equivalents" for each field of the zbookmark. 4034 * zbookmarks outside of the meta-dnode use their own object and level, and 4035 * calculate the level 0 equivalent (the first L0 blkid that is contained in the 4036 * blocks this bookmark refers to) by multiplying their blkid by their span 4037 * (the number of L0 blocks contained within one block at their level). 4038 * zbookmarks inside the meta-dnode calculate their object equivalent 4039 * (which is L0equiv * dnodes per data block), use 0 for their L0equiv, and use 4040 * level + 1<<31 (any value larger than a level could ever be) for their level. 4041 * This causes them to always compare before a bookmark in their object 4042 * equivalent, compare appropriately to bookmarks in other objects, and to 4043 * compare appropriately to other bookmarks in the meta-dnode. 4044 */ 4045int 4046zbookmark_compare(uint16_t dbss1, uint8_t ibs1, uint16_t dbss2, uint8_t ibs2, 4047 const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2) 4048{ 4049 /* 4050 * These variables represent the "equivalent" values for the zbookmark, 4051 * after converting zbookmarks inside the meta dnode to their 4052 * normal-object equivalents. 4053 */ 4054 uint64_t zb1obj, zb2obj; 4055 uint64_t zb1L0, zb2L0; 4056 uint64_t zb1level, zb2level; 4057 4058 if (zb1->zb_object == zb2->zb_object && 4059 zb1->zb_level == zb2->zb_level && 4060 zb1->zb_blkid == zb2->zb_blkid) 4061 return (0); 4062 4063 /* 4064 * BP_SPANB calculates the span in blocks. 4065 */ 4066 zb1L0 = (zb1->zb_blkid) * BP_SPANB(ibs1, zb1->zb_level); 4067 zb2L0 = (zb2->zb_blkid) * BP_SPANB(ibs2, zb2->zb_level); 4068 4069 if (zb1->zb_object == DMU_META_DNODE_OBJECT) { 4070 zb1obj = zb1L0 * (dbss1 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT)); 4071 zb1L0 = 0; 4072 zb1level = zb1->zb_level + COMPARE_META_LEVEL; 4073 } else { 4074 zb1obj = zb1->zb_object; 4075 zb1level = zb1->zb_level; 4076 } 4077 4078 if (zb2->zb_object == DMU_META_DNODE_OBJECT) { 4079 zb2obj = zb2L0 * (dbss2 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT)); 4080 zb2L0 = 0; 4081 zb2level = zb2->zb_level + COMPARE_META_LEVEL; 4082 } else { 4083 zb2obj = zb2->zb_object; 4084 zb2level = zb2->zb_level; 4085 } 4086 4087 /* Now that we have a canonical representation, do the comparison. */ 4088 if (zb1obj != zb2obj) 4089 return (zb1obj < zb2obj ? -1 : 1); 4090 else if (zb1L0 != zb2L0) 4091 return (zb1L0 < zb2L0 ? -1 : 1); 4092 else if (zb1level != zb2level) 4093 return (zb1level > zb2level ? -1 : 1); 4094 /* 4095 * This can (theoretically) happen if the bookmarks have the same object 4096 * and level, but different blkids, if the block sizes are not the same. 4097 * There is presently no way to change the indirect block sizes 4098 */ 4099 return (0); 4100} 4101 4102/* 4103 * This function checks the following: given that last_block is the place that 4104 * our traversal stopped last time, does that guarantee that we've visited 4105 * every node under subtree_root? Therefore, we can't just use the raw output 4106 * of zbookmark_compare. We have to pass in a modified version of 4107 * subtree_root; by incrementing the block id, and then checking whether 4108 * last_block is before or equal to that, we can tell whether or not having 4109 * visited last_block implies that all of subtree_root's children have been 4110 * visited. 4111 */ 4112boolean_t 4113zbookmark_subtree_completed(const dnode_phys_t *dnp, 4114 const zbookmark_phys_t *subtree_root, const zbookmark_phys_t *last_block) 4115{ 4116 zbookmark_phys_t mod_zb = *subtree_root; 4117 mod_zb.zb_blkid++; 4118 ASSERT(last_block->zb_level == 0); 4119 4120 /* The objset_phys_t isn't before anything. */ 4121 if (dnp == NULL) 4122 return (B_FALSE); 4123 4124 /* 4125 * We pass in 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT) for the 4126 * data block size in sectors, because that variable is only used if 4127 * the bookmark refers to a block in the meta-dnode. Since we don't 4128 * know without examining it what object it refers to, and there's no 4129 * harm in passing in this value in other cases, we always pass it in. 4130 * 4131 * We pass in 0 for the indirect block size shift because zb2 must be 4132 * level 0. The indirect block size is only used to calculate the span 4133 * of the bookmark, but since the bookmark must be level 0, the span is 4134 * always 1, so the math works out. 4135 * 4136 * If you make changes to how the zbookmark_compare code works, be sure 4137 * to make sure that this code still works afterwards. 4138 */ 4139 return (zbookmark_compare(dnp->dn_datablkszsec, dnp->dn_indblkshift, 4140 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT), 0, &mod_zb, 4141 last_block) <= 0); 4142} 4143