zio.c revision 321529
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, 2016 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 46SYSCTL_DECL(_vfs_zfs); 47SYSCTL_NODE(_vfs_zfs, OID_AUTO, zio, CTLFLAG_RW, 0, "ZFS ZIO"); 48#if defined(__amd64__) 49static int zio_use_uma = 1; 50#else 51static int zio_use_uma = 0; 52#endif 53SYSCTL_INT(_vfs_zfs_zio, OID_AUTO, use_uma, CTLFLAG_RDTUN, &zio_use_uma, 0, 54 "Use uma(9) for ZIO allocations"); 55static int zio_exclude_metadata = 0; 56SYSCTL_INT(_vfs_zfs_zio, OID_AUTO, exclude_metadata, CTLFLAG_RDTUN, &zio_exclude_metadata, 0, 57 "Exclude metadata buffers from dumps as well"); 58 59zio_trim_stats_t zio_trim_stats = { 60 { "bytes", KSTAT_DATA_UINT64, 61 "Number of bytes successfully TRIMmed" }, 62 { "success", KSTAT_DATA_UINT64, 63 "Number of successful TRIM requests" }, 64 { "unsupported", KSTAT_DATA_UINT64, 65 "Number of TRIM requests that failed because TRIM is not supported" }, 66 { "failed", KSTAT_DATA_UINT64, 67 "Number of TRIM requests that failed for reasons other than not supported" }, 68}; 69 70static kstat_t *zio_trim_ksp; 71 72/* 73 * ========================================================================== 74 * I/O type descriptions 75 * ========================================================================== 76 */ 77const char *zio_type_name[ZIO_TYPES] = { 78 "zio_null", "zio_read", "zio_write", "zio_free", "zio_claim", 79 "zio_ioctl" 80}; 81 82boolean_t zio_dva_throttle_enabled = B_TRUE; 83SYSCTL_INT(_vfs_zfs_zio, OID_AUTO, dva_throttle_enabled, CTLFLAG_RDTUN, 84 &zio_dva_throttle_enabled, 0, ""); 85 86/* 87 * ========================================================================== 88 * I/O kmem caches 89 * ========================================================================== 90 */ 91kmem_cache_t *zio_cache; 92kmem_cache_t *zio_link_cache; 93kmem_cache_t *zio_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; 94kmem_cache_t *zio_data_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; 95 96#ifdef _KERNEL 97extern vmem_t *zio_alloc_arena; 98#endif 99 100#define ZIO_PIPELINE_CONTINUE 0x100 101#define ZIO_PIPELINE_STOP 0x101 102 103#define BP_SPANB(indblkshift, level) \ 104 (((uint64_t)1) << ((level) * ((indblkshift) - SPA_BLKPTRSHIFT))) 105#define COMPARE_META_LEVEL 0x80000000ul 106/* 107 * The following actions directly effect the spa's sync-to-convergence logic. 108 * The values below define the sync pass when we start performing the action. 109 * Care should be taken when changing these values as they directly impact 110 * spa_sync() performance. Tuning these values may introduce subtle performance 111 * pathologies and should only be done in the context of performance analysis. 112 * These tunables will eventually be removed and replaced with #defines once 113 * enough analysis has been done to determine optimal values. 114 * 115 * The 'zfs_sync_pass_deferred_free' pass must be greater than 1 to ensure that 116 * regular blocks are not deferred. 117 */ 118int zfs_sync_pass_deferred_free = 2; /* defer frees starting in this pass */ 119SYSCTL_INT(_vfs_zfs, OID_AUTO, sync_pass_deferred_free, CTLFLAG_RDTUN, 120 &zfs_sync_pass_deferred_free, 0, "defer frees starting in this pass"); 121int zfs_sync_pass_dont_compress = 5; /* don't compress starting in this pass */ 122SYSCTL_INT(_vfs_zfs, OID_AUTO, sync_pass_dont_compress, CTLFLAG_RDTUN, 123 &zfs_sync_pass_dont_compress, 0, "don't compress starting in this pass"); 124int zfs_sync_pass_rewrite = 2; /* rewrite new bps starting in this pass */ 125SYSCTL_INT(_vfs_zfs, OID_AUTO, sync_pass_rewrite, CTLFLAG_RDTUN, 126 &zfs_sync_pass_rewrite, 0, "rewrite new bps starting in this pass"); 127 128/* 129 * An allocating zio is one that either currently has the DVA allocate 130 * stage set or will have it later in its lifetime. 131 */ 132#define IO_IS_ALLOCATING(zio) ((zio)->io_orig_pipeline & ZIO_STAGE_DVA_ALLOCATE) 133 134boolean_t zio_requeue_io_start_cut_in_line = B_TRUE; 135 136#ifdef illumos 137#ifdef ZFS_DEBUG 138int zio_buf_debug_limit = 16384; 139#else 140int zio_buf_debug_limit = 0; 141#endif 142#endif 143 144static void zio_taskq_dispatch(zio_t *, zio_taskq_type_t, boolean_t); 145 146void 147zio_init(void) 148{ 149 size_t c; 150 zio_cache = kmem_cache_create("zio_cache", 151 sizeof (zio_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 152 zio_link_cache = kmem_cache_create("zio_link_cache", 153 sizeof (zio_link_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 154 if (!zio_use_uma) 155 goto out; 156 157 /* 158 * For small buffers, we want a cache for each multiple of 159 * SPA_MINBLOCKSIZE. For larger buffers, we want a cache 160 * for each quarter-power of 2. 161 */ 162 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { 163 size_t size = (c + 1) << SPA_MINBLOCKSHIFT; 164 size_t p2 = size; 165 size_t align = 0; 166 int cflags = zio_exclude_metadata ? KMC_NODEBUG : 0; 167 168 while (!ISP2(p2)) 169 p2 &= p2 - 1; 170 171#ifdef illumos 172#ifndef _KERNEL 173 /* 174 * If we are using watchpoints, put each buffer on its own page, 175 * to eliminate the performance overhead of trapping to the 176 * kernel when modifying a non-watched buffer that shares the 177 * page with a watched buffer. 178 */ 179 if (arc_watch && !IS_P2ALIGNED(size, PAGESIZE)) 180 continue; 181#endif 182#endif /* illumos */ 183 if (size <= 4 * SPA_MINBLOCKSIZE) { 184 align = SPA_MINBLOCKSIZE; 185 } else if (IS_P2ALIGNED(size, p2 >> 2)) { 186 align = MIN(p2 >> 2, PAGESIZE); 187 } 188 189 if (align != 0) { 190 char name[36]; 191 (void) sprintf(name, "zio_buf_%lu", (ulong_t)size); 192 zio_buf_cache[c] = kmem_cache_create(name, size, 193 align, NULL, NULL, NULL, NULL, NULL, cflags); 194 195 /* 196 * Since zio_data bufs do not appear in crash dumps, we 197 * pass KMC_NOTOUCH so that no allocator metadata is 198 * stored with the buffers. 199 */ 200 (void) sprintf(name, "zio_data_buf_%lu", (ulong_t)size); 201 zio_data_buf_cache[c] = kmem_cache_create(name, size, 202 align, NULL, NULL, NULL, NULL, NULL, 203 cflags | KMC_NOTOUCH | KMC_NODEBUG); 204 } 205 } 206 207 while (--c != 0) { 208 ASSERT(zio_buf_cache[c] != NULL); 209 if (zio_buf_cache[c - 1] == NULL) 210 zio_buf_cache[c - 1] = zio_buf_cache[c]; 211 212 ASSERT(zio_data_buf_cache[c] != NULL); 213 if (zio_data_buf_cache[c - 1] == NULL) 214 zio_data_buf_cache[c - 1] = zio_data_buf_cache[c]; 215 } 216out: 217 218 zio_inject_init(); 219 220 zio_trim_ksp = kstat_create("zfs", 0, "zio_trim", "misc", 221 KSTAT_TYPE_NAMED, 222 sizeof(zio_trim_stats) / sizeof(kstat_named_t), 223 KSTAT_FLAG_VIRTUAL); 224 225 if (zio_trim_ksp != NULL) { 226 zio_trim_ksp->ks_data = &zio_trim_stats; 227 kstat_install(zio_trim_ksp); 228 } 229} 230 231void 232zio_fini(void) 233{ 234 size_t c; 235 kmem_cache_t *last_cache = NULL; 236 kmem_cache_t *last_data_cache = NULL; 237 238 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { 239 if (zio_buf_cache[c] != last_cache) { 240 last_cache = zio_buf_cache[c]; 241 kmem_cache_destroy(zio_buf_cache[c]); 242 } 243 zio_buf_cache[c] = NULL; 244 245 if (zio_data_buf_cache[c] != last_data_cache) { 246 last_data_cache = zio_data_buf_cache[c]; 247 kmem_cache_destroy(zio_data_buf_cache[c]); 248 } 249 zio_data_buf_cache[c] = NULL; 250 } 251 252 kmem_cache_destroy(zio_link_cache); 253 kmem_cache_destroy(zio_cache); 254 255 zio_inject_fini(); 256 257 if (zio_trim_ksp != NULL) { 258 kstat_delete(zio_trim_ksp); 259 zio_trim_ksp = NULL; 260 } 261} 262 263/* 264 * ========================================================================== 265 * Allocate and free I/O buffers 266 * ========================================================================== 267 */ 268 269/* 270 * Use zio_buf_alloc to allocate ZFS metadata. This data will appear in a 271 * crashdump if the kernel panics, so use it judiciously. Obviously, it's 272 * useful to inspect ZFS metadata, but if possible, we should avoid keeping 273 * excess / transient data in-core during a crashdump. 274 */ 275static void * 276zio_buf_alloc_impl(size_t size, boolean_t canwait) 277{ 278 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 279 int flags = zio_exclude_metadata ? KM_NODEBUG : 0; 280 281 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 282 283 if (zio_use_uma) { 284 return (kmem_cache_alloc(zio_buf_cache[c], 285 canwait ? KM_PUSHPAGE : KM_NOSLEEP)); 286 } else { 287 return (kmem_alloc(size, 288 (canwait ? KM_SLEEP : KM_NOSLEEP) | flags)); 289 } 290} 291 292void * 293zio_buf_alloc(size_t size) 294{ 295 return (zio_buf_alloc_impl(size, B_TRUE)); 296} 297 298void * 299zio_buf_alloc_nowait(size_t size) 300{ 301 return (zio_buf_alloc_impl(size, B_FALSE)); 302} 303 304/* 305 * Use zio_data_buf_alloc to allocate data. The data will not appear in a 306 * crashdump if the kernel panics. This exists so that we will limit the amount 307 * of ZFS data that shows up in a kernel crashdump. (Thus reducing the amount 308 * of kernel heap dumped to disk when the kernel panics) 309 */ 310void * 311zio_data_buf_alloc(size_t size) 312{ 313 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 314 315 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 316 317 if (zio_use_uma) 318 return (kmem_cache_alloc(zio_data_buf_cache[c], KM_PUSHPAGE)); 319 else 320 return (kmem_alloc(size, KM_SLEEP | KM_NODEBUG)); 321} 322 323void 324zio_buf_free(void *buf, size_t size) 325{ 326 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 327 328 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 329 330 if (zio_use_uma) 331 kmem_cache_free(zio_buf_cache[c], buf); 332 else 333 kmem_free(buf, size); 334} 335 336void 337zio_data_buf_free(void *buf, size_t size) 338{ 339 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 340 341 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 342 343 if (zio_use_uma) 344 kmem_cache_free(zio_data_buf_cache[c], buf); 345 else 346 kmem_free(buf, size); 347} 348 349/* 350 * ========================================================================== 351 * Push and pop I/O transform buffers 352 * ========================================================================== 353 */ 354void 355zio_push_transform(zio_t *zio, void *data, uint64_t size, uint64_t bufsize, 356 zio_transform_func_t *transform) 357{ 358 zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP); 359 360 zt->zt_orig_data = zio->io_data; 361 zt->zt_orig_size = zio->io_size; 362 zt->zt_bufsize = bufsize; 363 zt->zt_transform = transform; 364 365 zt->zt_next = zio->io_transform_stack; 366 zio->io_transform_stack = zt; 367 368 zio->io_data = data; 369 zio->io_size = size; 370} 371 372void 373zio_pop_transforms(zio_t *zio) 374{ 375 zio_transform_t *zt; 376 377 while ((zt = zio->io_transform_stack) != NULL) { 378 if (zt->zt_transform != NULL) 379 zt->zt_transform(zio, 380 zt->zt_orig_data, zt->zt_orig_size); 381 382 if (zt->zt_bufsize != 0) 383 zio_buf_free(zio->io_data, zt->zt_bufsize); 384 385 zio->io_data = zt->zt_orig_data; 386 zio->io_size = zt->zt_orig_size; 387 zio->io_transform_stack = zt->zt_next; 388 389 kmem_free(zt, sizeof (zio_transform_t)); 390 } 391} 392 393/* 394 * ========================================================================== 395 * I/O transform callbacks for subblocks and decompression 396 * ========================================================================== 397 */ 398static void 399zio_subblock(zio_t *zio, void *data, uint64_t size) 400{ 401 ASSERT(zio->io_size > size); 402 403 if (zio->io_type == ZIO_TYPE_READ) 404 bcopy(zio->io_data, data, size); 405} 406 407static void 408zio_decompress(zio_t *zio, void *data, uint64_t size) 409{ 410 if (zio->io_error == 0 && 411 zio_decompress_data(BP_GET_COMPRESS(zio->io_bp), 412 zio->io_data, data, zio->io_size, size) != 0) 413 zio->io_error = SET_ERROR(EIO); 414} 415 416/* 417 * ========================================================================== 418 * I/O parent/child relationships and pipeline interlocks 419 * ========================================================================== 420 */ 421zio_t * 422zio_walk_parents(zio_t *cio, zio_link_t **zl) 423{ 424 list_t *pl = &cio->io_parent_list; 425 426 *zl = (*zl == NULL) ? list_head(pl) : list_next(pl, *zl); 427 if (*zl == NULL) 428 return (NULL); 429 430 ASSERT((*zl)->zl_child == cio); 431 return ((*zl)->zl_parent); 432} 433 434zio_t * 435zio_walk_children(zio_t *pio, zio_link_t **zl) 436{ 437 list_t *cl = &pio->io_child_list; 438 439 *zl = (*zl == NULL) ? list_head(cl) : list_next(cl, *zl); 440 if (*zl == NULL) 441 return (NULL); 442 443 ASSERT((*zl)->zl_parent == pio); 444 return ((*zl)->zl_child); 445} 446 447zio_t * 448zio_unique_parent(zio_t *cio) 449{ 450 zio_link_t *zl = NULL; 451 zio_t *pio = zio_walk_parents(cio, &zl); 452 453 VERIFY3P(zio_walk_parents(cio, &zl), ==, NULL); 454 return (pio); 455} 456 457void 458zio_add_child(zio_t *pio, zio_t *cio) 459{ 460 zio_link_t *zl = kmem_cache_alloc(zio_link_cache, KM_SLEEP); 461 462 /* 463 * Logical I/Os can have logical, gang, or vdev children. 464 * Gang I/Os can have gang or vdev children. 465 * Vdev I/Os can only have vdev children. 466 * The following ASSERT captures all of these constraints. 467 */ 468 ASSERT(cio->io_child_type <= pio->io_child_type); 469 470 zl->zl_parent = pio; 471 zl->zl_child = cio; 472 473 mutex_enter(&cio->io_lock); 474 mutex_enter(&pio->io_lock); 475 476 ASSERT(pio->io_state[ZIO_WAIT_DONE] == 0); 477 478 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 479 pio->io_children[cio->io_child_type][w] += !cio->io_state[w]; 480 481 list_insert_head(&pio->io_child_list, zl); 482 list_insert_head(&cio->io_parent_list, zl); 483 484 pio->io_child_count++; 485 cio->io_parent_count++; 486 487 mutex_exit(&pio->io_lock); 488 mutex_exit(&cio->io_lock); 489} 490 491static void 492zio_remove_child(zio_t *pio, zio_t *cio, zio_link_t *zl) 493{ 494 ASSERT(zl->zl_parent == pio); 495 ASSERT(zl->zl_child == cio); 496 497 mutex_enter(&cio->io_lock); 498 mutex_enter(&pio->io_lock); 499 500 list_remove(&pio->io_child_list, zl); 501 list_remove(&cio->io_parent_list, zl); 502 503 pio->io_child_count--; 504 cio->io_parent_count--; 505 506 mutex_exit(&pio->io_lock); 507 mutex_exit(&cio->io_lock); 508 509 kmem_cache_free(zio_link_cache, zl); 510} 511 512static boolean_t 513zio_wait_for_children(zio_t *zio, enum zio_child child, enum zio_wait_type wait) 514{ 515 uint64_t *countp = &zio->io_children[child][wait]; 516 boolean_t waiting = B_FALSE; 517 518 mutex_enter(&zio->io_lock); 519 ASSERT(zio->io_stall == NULL); 520 if (*countp != 0) { 521 zio->io_stage >>= 1; 522 ASSERT3U(zio->io_stage, !=, ZIO_STAGE_OPEN); 523 zio->io_stall = countp; 524 waiting = B_TRUE; 525 } 526 mutex_exit(&zio->io_lock); 527 528 return (waiting); 529} 530 531static void 532zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait) 533{ 534 uint64_t *countp = &pio->io_children[zio->io_child_type][wait]; 535 int *errorp = &pio->io_child_error[zio->io_child_type]; 536 537 mutex_enter(&pio->io_lock); 538 if (zio->io_error && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE)) 539 *errorp = zio_worst_error(*errorp, zio->io_error); 540 pio->io_reexecute |= zio->io_reexecute; 541 ASSERT3U(*countp, >, 0); 542 543 (*countp)--; 544 545 if (*countp == 0 && pio->io_stall == countp) { 546 zio_taskq_type_t type = 547 pio->io_stage < ZIO_STAGE_VDEV_IO_START ? ZIO_TASKQ_ISSUE : 548 ZIO_TASKQ_INTERRUPT; 549 pio->io_stall = NULL; 550 mutex_exit(&pio->io_lock); 551 /* 552 * Dispatch the parent zio in its own taskq so that 553 * the child can continue to make progress. This also 554 * prevents overflowing the stack when we have deeply nested 555 * parent-child relationships. 556 */ 557 zio_taskq_dispatch(pio, type, B_FALSE); 558 } else { 559 mutex_exit(&pio->io_lock); 560 } 561} 562 563static void 564zio_inherit_child_errors(zio_t *zio, enum zio_child c) 565{ 566 if (zio->io_child_error[c] != 0 && zio->io_error == 0) 567 zio->io_error = zio->io_child_error[c]; 568} 569 570int 571zio_timestamp_compare(const void *x1, const void *x2) 572{ 573 const zio_t *z1 = x1; 574 const zio_t *z2 = x2; 575 576 if (z1->io_queued_timestamp < z2->io_queued_timestamp) 577 return (-1); 578 if (z1->io_queued_timestamp > z2->io_queued_timestamp) 579 return (1); 580 581 if (z1->io_bookmark.zb_objset < z2->io_bookmark.zb_objset) 582 return (-1); 583 if (z1->io_bookmark.zb_objset > z2->io_bookmark.zb_objset) 584 return (1); 585 586 if (z1->io_bookmark.zb_object < z2->io_bookmark.zb_object) 587 return (-1); 588 if (z1->io_bookmark.zb_object > z2->io_bookmark.zb_object) 589 return (1); 590 591 if (z1->io_bookmark.zb_level < z2->io_bookmark.zb_level) 592 return (-1); 593 if (z1->io_bookmark.zb_level > z2->io_bookmark.zb_level) 594 return (1); 595 596 if (z1->io_bookmark.zb_blkid < z2->io_bookmark.zb_blkid) 597 return (-1); 598 if (z1->io_bookmark.zb_blkid > z2->io_bookmark.zb_blkid) 599 return (1); 600 601 if (z1 < z2) 602 return (-1); 603 if (z1 > z2) 604 return (1); 605 606 return (0); 607} 608 609/* 610 * ========================================================================== 611 * Create the various types of I/O (read, write, free, etc) 612 * ========================================================================== 613 */ 614static zio_t * 615zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 616 void *data, uint64_t size, zio_done_func_t *done, void *private, 617 zio_type_t type, zio_priority_t priority, enum zio_flag flags, 618 vdev_t *vd, uint64_t offset, const zbookmark_phys_t *zb, 619 enum zio_stage stage, enum zio_stage pipeline) 620{ 621 zio_t *zio; 622 623 ASSERT3U(type == ZIO_TYPE_FREE || size, <=, SPA_MAXBLOCKSIZE); 624 ASSERT(P2PHASE(size, SPA_MINBLOCKSIZE) == 0); 625 ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0); 626 627 ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER)); 628 ASSERT(!bp || !(flags & ZIO_FLAG_CONFIG_WRITER)); 629 ASSERT(vd || stage == ZIO_STAGE_OPEN); 630 631 zio = kmem_cache_alloc(zio_cache, KM_SLEEP); 632 bzero(zio, sizeof (zio_t)); 633 634 mutex_init(&zio->io_lock, NULL, MUTEX_DEFAULT, NULL); 635 cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL); 636 637 list_create(&zio->io_parent_list, sizeof (zio_link_t), 638 offsetof(zio_link_t, zl_parent_node)); 639 list_create(&zio->io_child_list, sizeof (zio_link_t), 640 offsetof(zio_link_t, zl_child_node)); 641 metaslab_trace_init(&zio->io_alloc_list); 642 643 if (vd != NULL) 644 zio->io_child_type = ZIO_CHILD_VDEV; 645 else if (flags & ZIO_FLAG_GANG_CHILD) 646 zio->io_child_type = ZIO_CHILD_GANG; 647 else if (flags & ZIO_FLAG_DDT_CHILD) 648 zio->io_child_type = ZIO_CHILD_DDT; 649 else 650 zio->io_child_type = ZIO_CHILD_LOGICAL; 651 652 if (bp != NULL) { 653 zio->io_bp = (blkptr_t *)bp; 654 zio->io_bp_copy = *bp; 655 zio->io_bp_orig = *bp; 656 if (type != ZIO_TYPE_WRITE || 657 zio->io_child_type == ZIO_CHILD_DDT) 658 zio->io_bp = &zio->io_bp_copy; /* so caller can free */ 659 if (zio->io_child_type == ZIO_CHILD_LOGICAL) 660 zio->io_logical = zio; 661 if (zio->io_child_type > ZIO_CHILD_GANG && BP_IS_GANG(bp)) 662 pipeline |= ZIO_GANG_STAGES; 663 } 664 665 zio->io_spa = spa; 666 zio->io_txg = txg; 667 zio->io_done = done; 668 zio->io_private = private; 669 zio->io_type = type; 670 zio->io_priority = priority; 671 zio->io_vd = vd; 672 zio->io_offset = offset; 673 zio->io_orig_data = zio->io_data = data; 674 zio->io_orig_size = zio->io_size = size; 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, 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 void *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, 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 void *data, uint64_t size, 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, size, 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, void *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, 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 NULL, NULL, ZIO_TYPE_FREE, ZIO_PRIORITY_NOW, flags, 963 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 done, private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW, flags, 997 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, size, done, private, 1013 ZIO_TYPE_IOCTL, priority, flags, vd, offset, 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 void *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, done, private, 1041 ZIO_TYPE_READ, priority, flags | ZIO_FLAG_PHYSICAL, vd, offset, 1042 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 void *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, done, private, 1062 ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_PHYSICAL, vd, offset, 1063 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 void *wbuf = zio_buf_alloc(size); 1075 bcopy(data, wbuf, size); 1076 zio_push_transform(zio, wbuf, size, size, NULL); 1077 } 1078 1079 return (zio); 1080} 1081 1082/* 1083 * Create a child I/O to do some work for us. 1084 */ 1085zio_t * 1086zio_vdev_child_io(zio_t *pio, blkptr_t *bp, vdev_t *vd, uint64_t offset, 1087 void *data, uint64_t size, int type, zio_priority_t priority, 1088 enum zio_flag flags, zio_done_func_t *done, void *private) 1089{ 1090 enum zio_stage pipeline = ZIO_VDEV_CHILD_PIPELINE; 1091 zio_t *zio; 1092 1093 ASSERT(vd->vdev_parent == 1094 (pio->io_vd ? pio->io_vd : pio->io_spa->spa_root_vdev)); 1095 1096 if (type == ZIO_TYPE_READ && bp != NULL) { 1097 /* 1098 * If we have the bp, then the child should perform the 1099 * checksum and the parent need not. This pushes error 1100 * detection as close to the leaves as possible and 1101 * eliminates redundant checksums in the interior nodes. 1102 */ 1103 pipeline |= ZIO_STAGE_CHECKSUM_VERIFY; 1104 pio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 1105 } 1106 1107 /* Not all IO types require vdev io done stage e.g. free */ 1108 if (!(pio->io_pipeline & ZIO_STAGE_VDEV_IO_DONE)) 1109 pipeline &= ~ZIO_STAGE_VDEV_IO_DONE; 1110 1111 if (vd->vdev_children == 0) 1112 offset += VDEV_LABEL_START_SIZE; 1113 1114 flags |= ZIO_VDEV_CHILD_FLAGS(pio) | ZIO_FLAG_DONT_PROPAGATE; 1115 1116 /* 1117 * If we've decided to do a repair, the write is not speculative -- 1118 * even if the original read was. 1119 */ 1120 if (flags & ZIO_FLAG_IO_REPAIR) 1121 flags &= ~ZIO_FLAG_SPECULATIVE; 1122 1123 /* 1124 * If we're creating a child I/O that is not associated with a 1125 * top-level vdev, then the child zio is not an allocating I/O. 1126 * If this is a retried I/O then we ignore it since we will 1127 * have already processed the original allocating I/O. 1128 */ 1129 if (flags & ZIO_FLAG_IO_ALLOCATING && 1130 (vd != vd->vdev_top || (flags & ZIO_FLAG_IO_RETRY))) { 1131 metaslab_class_t *mc = spa_normal_class(pio->io_spa); 1132 1133 ASSERT(mc->mc_alloc_throttle_enabled); 1134 ASSERT(type == ZIO_TYPE_WRITE); 1135 ASSERT(priority == ZIO_PRIORITY_ASYNC_WRITE); 1136 ASSERT(!(flags & ZIO_FLAG_IO_REPAIR)); 1137 ASSERT(!(pio->io_flags & ZIO_FLAG_IO_REWRITE) || 1138 pio->io_child_type == ZIO_CHILD_GANG); 1139 1140 flags &= ~ZIO_FLAG_IO_ALLOCATING; 1141 } 1142 1143 zio = zio_create(pio, pio->io_spa, pio->io_txg, bp, data, size, 1144 done, private, type, priority, flags, vd, offset, &pio->io_bookmark, 1145 ZIO_STAGE_VDEV_IO_START >> 1, pipeline); 1146 ASSERT3U(zio->io_child_type, ==, ZIO_CHILD_VDEV); 1147 1148 zio->io_physdone = pio->io_physdone; 1149 if (vd->vdev_ops->vdev_op_leaf && zio->io_logical != NULL) 1150 zio->io_logical->io_phys_children++; 1151 1152 return (zio); 1153} 1154 1155zio_t * 1156zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, void *data, uint64_t size, 1157 int type, zio_priority_t priority, enum zio_flag flags, 1158 zio_done_func_t *done, void *private) 1159{ 1160 zio_t *zio; 1161 1162 ASSERT(vd->vdev_ops->vdev_op_leaf); 1163 1164 zio = zio_create(NULL, vd->vdev_spa, 0, NULL, 1165 data, size, done, private, type, priority, 1166 flags | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY | ZIO_FLAG_DELEGATED, 1167 vd, offset, NULL, 1168 ZIO_STAGE_VDEV_IO_START >> 1, ZIO_VDEV_CHILD_PIPELINE); 1169 1170 return (zio); 1171} 1172 1173void 1174zio_flush(zio_t *zio, vdev_t *vd) 1175{ 1176 zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE, 0, 0, 1177 NULL, NULL, ZIO_PRIORITY_NOW, 1178 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY)); 1179} 1180 1181zio_t * 1182zio_trim(zio_t *zio, spa_t *spa, vdev_t *vd, uint64_t offset, uint64_t size) 1183{ 1184 1185 ASSERT(vd->vdev_ops->vdev_op_leaf); 1186 1187 return (zio_create(zio, spa, 0, NULL, NULL, size, NULL, NULL, 1188 ZIO_TYPE_FREE, ZIO_PRIORITY_TRIM, ZIO_FLAG_DONT_AGGREGATE | 1189 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY, 1190 vd, offset, NULL, ZIO_STAGE_OPEN, ZIO_FREE_PHYS_PIPELINE)); 1191} 1192 1193void 1194zio_shrink(zio_t *zio, uint64_t size) 1195{ 1196 ASSERT(zio->io_executor == NULL); 1197 ASSERT(zio->io_orig_size == zio->io_size); 1198 ASSERT(size <= zio->io_size); 1199 1200 /* 1201 * We don't shrink for raidz because of problems with the 1202 * reconstruction when reading back less than the block size. 1203 * Note, BP_IS_RAIDZ() assumes no compression. 1204 */ 1205 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 1206 if (!BP_IS_RAIDZ(zio->io_bp)) 1207 zio->io_orig_size = zio->io_size = size; 1208} 1209 1210/* 1211 * ========================================================================== 1212 * Prepare to read and write logical blocks 1213 * ========================================================================== 1214 */ 1215 1216static int 1217zio_read_bp_init(zio_t *zio) 1218{ 1219 blkptr_t *bp = zio->io_bp; 1220 1221 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF && 1222 zio->io_child_type == ZIO_CHILD_LOGICAL && 1223 !(zio->io_flags & ZIO_FLAG_RAW)) { 1224 uint64_t psize = 1225 BP_IS_EMBEDDED(bp) ? BPE_GET_PSIZE(bp) : BP_GET_PSIZE(bp); 1226 void *cbuf = zio_buf_alloc(psize); 1227 1228 zio_push_transform(zio, cbuf, psize, psize, zio_decompress); 1229 } 1230 1231 if (BP_IS_EMBEDDED(bp) && BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA) { 1232 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1233 decode_embedded_bp_compressed(bp, zio->io_data); 1234 } else { 1235 ASSERT(!BP_IS_EMBEDDED(bp)); 1236 } 1237 1238 if (!DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) && BP_GET_LEVEL(bp) == 0) 1239 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 1240 1241 if (BP_GET_TYPE(bp) == DMU_OT_DDT_ZAP) 1242 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 1243 1244 if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL) 1245 zio->io_pipeline = ZIO_DDT_READ_PIPELINE; 1246 1247 return (ZIO_PIPELINE_CONTINUE); 1248} 1249 1250static int 1251zio_write_bp_init(zio_t *zio) 1252{ 1253 if (!IO_IS_ALLOCATING(zio)) 1254 return (ZIO_PIPELINE_CONTINUE); 1255 1256 ASSERT(zio->io_child_type != ZIO_CHILD_DDT); 1257 1258 if (zio->io_bp_override) { 1259 blkptr_t *bp = zio->io_bp; 1260 zio_prop_t *zp = &zio->io_prop; 1261 1262 ASSERT(bp->blk_birth != zio->io_txg); 1263 ASSERT(BP_GET_DEDUP(zio->io_bp_override) == 0); 1264 1265 *bp = *zio->io_bp_override; 1266 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1267 1268 if (BP_IS_EMBEDDED(bp)) 1269 return (ZIO_PIPELINE_CONTINUE); 1270 1271 /* 1272 * If we've been overridden and nopwrite is set then 1273 * set the flag accordingly to indicate that a nopwrite 1274 * has already occurred. 1275 */ 1276 if (!BP_IS_HOLE(bp) && zp->zp_nopwrite) { 1277 ASSERT(!zp->zp_dedup); 1278 ASSERT3U(BP_GET_CHECKSUM(bp), ==, zp->zp_checksum); 1279 zio->io_flags |= ZIO_FLAG_NOPWRITE; 1280 return (ZIO_PIPELINE_CONTINUE); 1281 } 1282 1283 ASSERT(!zp->zp_nopwrite); 1284 1285 if (BP_IS_HOLE(bp) || !zp->zp_dedup) 1286 return (ZIO_PIPELINE_CONTINUE); 1287 1288 ASSERT((zio_checksum_table[zp->zp_checksum].ci_flags & 1289 ZCHECKSUM_FLAG_DEDUP) || zp->zp_dedup_verify); 1290 1291 if (BP_GET_CHECKSUM(bp) == zp->zp_checksum) { 1292 BP_SET_DEDUP(bp, 1); 1293 zio->io_pipeline |= ZIO_STAGE_DDT_WRITE; 1294 return (ZIO_PIPELINE_CONTINUE); 1295 } 1296 1297 /* 1298 * We were unable to handle this as an override bp, treat 1299 * it as a regular write I/O. 1300 */ 1301 zio->io_bp_override = NULL; 1302 *bp = zio->io_bp_orig; 1303 zio->io_pipeline = zio->io_orig_pipeline; 1304 } 1305 1306 return (ZIO_PIPELINE_CONTINUE); 1307} 1308 1309static int 1310zio_write_compress(zio_t *zio) 1311{ 1312 spa_t *spa = zio->io_spa; 1313 zio_prop_t *zp = &zio->io_prop; 1314 enum zio_compress compress = zp->zp_compress; 1315 blkptr_t *bp = zio->io_bp; 1316 uint64_t lsize = zio->io_size; 1317 uint64_t psize = lsize; 1318 int pass = 1; 1319 1320 /* 1321 * If our children haven't all reached the ready stage, 1322 * wait for them and then repeat this pipeline stage. 1323 */ 1324 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 1325 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_READY)) 1326 return (ZIO_PIPELINE_STOP); 1327 1328 if (!IO_IS_ALLOCATING(zio)) 1329 return (ZIO_PIPELINE_CONTINUE); 1330 1331 if (zio->io_children_ready != NULL) { 1332 /* 1333 * Now that all our children are ready, run the callback 1334 * associated with this zio in case it wants to modify the 1335 * data to be written. 1336 */ 1337 ASSERT3U(zp->zp_level, >, 0); 1338 zio->io_children_ready(zio); 1339 } 1340 1341 ASSERT(zio->io_child_type != ZIO_CHILD_DDT); 1342 ASSERT(zio->io_bp_override == NULL); 1343 1344 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg) { 1345 /* 1346 * We're rewriting an existing block, which means we're 1347 * working on behalf of spa_sync(). For spa_sync() to 1348 * converge, it must eventually be the case that we don't 1349 * have to allocate new blocks. But compression changes 1350 * the blocksize, which forces a reallocate, and makes 1351 * convergence take longer. Therefore, after the first 1352 * few passes, stop compressing to ensure convergence. 1353 */ 1354 pass = spa_sync_pass(spa); 1355 1356 ASSERT(zio->io_txg == spa_syncing_txg(spa)); 1357 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1358 ASSERT(!BP_GET_DEDUP(bp)); 1359 1360 if (pass >= zfs_sync_pass_dont_compress) 1361 compress = ZIO_COMPRESS_OFF; 1362 1363 /* Make sure someone doesn't change their mind on overwrites */ 1364 ASSERT(BP_IS_EMBEDDED(bp) || MIN(zp->zp_copies + BP_IS_GANG(bp), 1365 spa_max_replication(spa)) == BP_GET_NDVAS(bp)); 1366 } 1367 1368 if (compress != ZIO_COMPRESS_OFF) { 1369 void *cbuf = zio_buf_alloc(lsize); 1370 psize = zio_compress_data(compress, zio->io_data, cbuf, lsize); 1371 if (psize == 0 || psize == lsize) { 1372 compress = ZIO_COMPRESS_OFF; 1373 zio_buf_free(cbuf, lsize); 1374 } else if (!zp->zp_dedup && psize <= BPE_PAYLOAD_SIZE && 1375 zp->zp_level == 0 && !DMU_OT_HAS_FILL(zp->zp_type) && 1376 spa_feature_is_enabled(spa, SPA_FEATURE_EMBEDDED_DATA)) { 1377 encode_embedded_bp_compressed(bp, 1378 cbuf, compress, lsize, psize); 1379 BPE_SET_ETYPE(bp, BP_EMBEDDED_TYPE_DATA); 1380 BP_SET_TYPE(bp, zio->io_prop.zp_type); 1381 BP_SET_LEVEL(bp, zio->io_prop.zp_level); 1382 zio_buf_free(cbuf, lsize); 1383 bp->blk_birth = zio->io_txg; 1384 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1385 ASSERT(spa_feature_is_active(spa, 1386 SPA_FEATURE_EMBEDDED_DATA)); 1387 return (ZIO_PIPELINE_CONTINUE); 1388 } else { 1389 /* 1390 * Round up compressed size up to the ashift 1391 * of the smallest-ashift device, and zero the tail. 1392 * This ensures that the compressed size of the BP 1393 * (and thus compressratio property) are correct, 1394 * in that we charge for the padding used to fill out 1395 * the last sector. 1396 */ 1397 ASSERT3U(spa->spa_min_ashift, >=, SPA_MINBLOCKSHIFT); 1398 size_t rounded = (size_t)P2ROUNDUP(psize, 1399 1ULL << spa->spa_min_ashift); 1400 if (rounded >= lsize) { 1401 compress = ZIO_COMPRESS_OFF; 1402 zio_buf_free(cbuf, lsize); 1403 psize = lsize; 1404 } else { 1405 bzero((char *)cbuf + psize, rounded - psize); 1406 psize = rounded; 1407 zio_push_transform(zio, cbuf, 1408 psize, lsize, NULL); 1409 } 1410 } 1411 1412 /* 1413 * We were unable to handle this as an override bp, treat 1414 * it as a regular write I/O. 1415 */ 1416 zio->io_bp_override = NULL; 1417 *bp = zio->io_bp_orig; 1418 zio->io_pipeline = zio->io_orig_pipeline; 1419 } 1420 1421 /* 1422 * The final pass of spa_sync() must be all rewrites, but the first 1423 * few passes offer a trade-off: allocating blocks defers convergence, 1424 * but newly allocated blocks are sequential, so they can be written 1425 * to disk faster. Therefore, we allow the first few passes of 1426 * spa_sync() to allocate new blocks, but force rewrites after that. 1427 * There should only be a handful of blocks after pass 1 in any case. 1428 */ 1429 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg && 1430 BP_GET_PSIZE(bp) == psize && 1431 pass >= zfs_sync_pass_rewrite) { 1432 ASSERT(psize != 0); 1433 enum zio_stage gang_stages = zio->io_pipeline & ZIO_GANG_STAGES; 1434 zio->io_pipeline = ZIO_REWRITE_PIPELINE | gang_stages; 1435 zio->io_flags |= ZIO_FLAG_IO_REWRITE; 1436 } else { 1437 BP_ZERO(bp); 1438 zio->io_pipeline = ZIO_WRITE_PIPELINE; 1439 } 1440 1441 if (psize == 0) { 1442 if (zio->io_bp_orig.blk_birth != 0 && 1443 spa_feature_is_active(spa, SPA_FEATURE_HOLE_BIRTH)) { 1444 BP_SET_LSIZE(bp, lsize); 1445 BP_SET_TYPE(bp, zp->zp_type); 1446 BP_SET_LEVEL(bp, zp->zp_level); 1447 BP_SET_BIRTH(bp, zio->io_txg, 0); 1448 } 1449 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1450 } else { 1451 ASSERT(zp->zp_checksum != ZIO_CHECKSUM_GANG_HEADER); 1452 BP_SET_LSIZE(bp, lsize); 1453 BP_SET_TYPE(bp, zp->zp_type); 1454 BP_SET_LEVEL(bp, zp->zp_level); 1455 BP_SET_PSIZE(bp, psize); 1456 BP_SET_COMPRESS(bp, compress); 1457 BP_SET_CHECKSUM(bp, zp->zp_checksum); 1458 BP_SET_DEDUP(bp, zp->zp_dedup); 1459 BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER); 1460 if (zp->zp_dedup) { 1461 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1462 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1463 zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE; 1464 } 1465 if (zp->zp_nopwrite) { 1466 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1467 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1468 zio->io_pipeline |= ZIO_STAGE_NOP_WRITE; 1469 } 1470 } 1471 return (ZIO_PIPELINE_CONTINUE); 1472} 1473 1474static int 1475zio_free_bp_init(zio_t *zio) 1476{ 1477 blkptr_t *bp = zio->io_bp; 1478 1479 if (zio->io_child_type == ZIO_CHILD_LOGICAL) { 1480 if (BP_GET_DEDUP(bp)) 1481 zio->io_pipeline = ZIO_DDT_FREE_PIPELINE; 1482 } 1483 1484 return (ZIO_PIPELINE_CONTINUE); 1485} 1486 1487/* 1488 * ========================================================================== 1489 * Execute the I/O pipeline 1490 * ========================================================================== 1491 */ 1492 1493static void 1494zio_taskq_dispatch(zio_t *zio, zio_taskq_type_t q, boolean_t cutinline) 1495{ 1496 spa_t *spa = zio->io_spa; 1497 zio_type_t t = zio->io_type; 1498 int flags = (cutinline ? TQ_FRONT : 0); 1499 1500 ASSERT(q == ZIO_TASKQ_ISSUE || q == ZIO_TASKQ_INTERRUPT); 1501 1502 /* 1503 * If we're a config writer or a probe, the normal issue and 1504 * interrupt threads may all be blocked waiting for the config lock. 1505 * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL. 1506 */ 1507 if (zio->io_flags & (ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_PROBE)) 1508 t = ZIO_TYPE_NULL; 1509 1510 /* 1511 * A similar issue exists for the L2ARC write thread until L2ARC 2.0. 1512 */ 1513 if (t == ZIO_TYPE_WRITE && zio->io_vd && zio->io_vd->vdev_aux) 1514 t = ZIO_TYPE_NULL; 1515 1516 /* 1517 * If this is a high priority I/O, then use the high priority taskq if 1518 * available. 1519 */ 1520 if (zio->io_priority == ZIO_PRIORITY_NOW && 1521 spa->spa_zio_taskq[t][q + 1].stqs_count != 0) 1522 q++; 1523 1524 ASSERT3U(q, <, ZIO_TASKQ_TYPES); 1525 1526 /* 1527 * NB: We are assuming that the zio can only be dispatched 1528 * to a single taskq at a time. It would be a grievous error 1529 * to dispatch the zio to another taskq at the same time. 1530 */ 1531#if defined(illumos) || !defined(_KERNEL) 1532 ASSERT(zio->io_tqent.tqent_next == NULL); 1533#else 1534 ASSERT(zio->io_tqent.tqent_task.ta_pending == 0); 1535#endif 1536 spa_taskq_dispatch_ent(spa, t, q, (task_func_t *)zio_execute, zio, 1537 flags, &zio->io_tqent); 1538} 1539 1540static boolean_t 1541zio_taskq_member(zio_t *zio, zio_taskq_type_t q) 1542{ 1543 kthread_t *executor = zio->io_executor; 1544 spa_t *spa = zio->io_spa; 1545 1546 for (zio_type_t t = 0; t < ZIO_TYPES; t++) { 1547 spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q]; 1548 uint_t i; 1549 for (i = 0; i < tqs->stqs_count; i++) { 1550 if (taskq_member(tqs->stqs_taskq[i], executor)) 1551 return (B_TRUE); 1552 } 1553 } 1554 1555 return (B_FALSE); 1556} 1557 1558static int 1559zio_issue_async(zio_t *zio) 1560{ 1561 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 1562 1563 return (ZIO_PIPELINE_STOP); 1564} 1565 1566void 1567zio_interrupt(zio_t *zio) 1568{ 1569 zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE); 1570} 1571 1572void 1573zio_delay_interrupt(zio_t *zio) 1574{ 1575 /* 1576 * The timeout_generic() function isn't defined in userspace, so 1577 * rather than trying to implement the function, the zio delay 1578 * functionality has been disabled for userspace builds. 1579 */ 1580 1581#ifdef _KERNEL 1582 /* 1583 * If io_target_timestamp is zero, then no delay has been registered 1584 * for this IO, thus jump to the end of this function and "skip" the 1585 * delay; issuing it directly to the zio layer. 1586 */ 1587 if (zio->io_target_timestamp != 0) { 1588 hrtime_t now = gethrtime(); 1589 1590 if (now >= zio->io_target_timestamp) { 1591 /* 1592 * This IO has already taken longer than the target 1593 * delay to complete, so we don't want to delay it 1594 * any longer; we "miss" the delay and issue it 1595 * directly to the zio layer. This is likely due to 1596 * the target latency being set to a value less than 1597 * the underlying hardware can satisfy (e.g. delay 1598 * set to 1ms, but the disks take 10ms to complete an 1599 * IO request). 1600 */ 1601 1602 DTRACE_PROBE2(zio__delay__miss, zio_t *, zio, 1603 hrtime_t, now); 1604 1605 zio_interrupt(zio); 1606 } else { 1607 hrtime_t diff = zio->io_target_timestamp - now; 1608 1609 DTRACE_PROBE3(zio__delay__hit, zio_t *, zio, 1610 hrtime_t, now, hrtime_t, diff); 1611 1612 (void) timeout_generic(CALLOUT_NORMAL, 1613 (void (*)(void *))zio_interrupt, zio, diff, 1, 0); 1614 } 1615 1616 return; 1617 } 1618#endif 1619 1620 DTRACE_PROBE1(zio__delay__skip, zio_t *, zio); 1621 zio_interrupt(zio); 1622} 1623 1624/* 1625 * Execute the I/O pipeline until one of the following occurs: 1626 * 1627 * (1) the I/O completes 1628 * (2) the pipeline stalls waiting for dependent child I/Os 1629 * (3) the I/O issues, so we're waiting for an I/O completion interrupt 1630 * (4) the I/O is delegated by vdev-level caching or aggregation 1631 * (5) the I/O is deferred due to vdev-level queueing 1632 * (6) the I/O is handed off to another thread. 1633 * 1634 * In all cases, the pipeline stops whenever there's no CPU work; it never 1635 * burns a thread in cv_wait(). 1636 * 1637 * There's no locking on io_stage because there's no legitimate way 1638 * for multiple threads to be attempting to process the same I/O. 1639 */ 1640static zio_pipe_stage_t *zio_pipeline[]; 1641 1642void 1643zio_execute(zio_t *zio) 1644{ 1645 zio->io_executor = curthread; 1646 1647 ASSERT3U(zio->io_queued_timestamp, >, 0); 1648 1649 while (zio->io_stage < ZIO_STAGE_DONE) { 1650 enum zio_stage pipeline = zio->io_pipeline; 1651 enum zio_stage stage = zio->io_stage; 1652 int rv; 1653 1654 ASSERT(!MUTEX_HELD(&zio->io_lock)); 1655 ASSERT(ISP2(stage)); 1656 ASSERT(zio->io_stall == NULL); 1657 1658 do { 1659 stage <<= 1; 1660 } while ((stage & pipeline) == 0); 1661 1662 ASSERT(stage <= ZIO_STAGE_DONE); 1663 1664 /* 1665 * If we are in interrupt context and this pipeline stage 1666 * will grab a config lock that is held across I/O, 1667 * or may wait for an I/O that needs an interrupt thread 1668 * to complete, issue async to avoid deadlock. 1669 * 1670 * For VDEV_IO_START, we cut in line so that the io will 1671 * be sent to disk promptly. 1672 */ 1673 if ((stage & ZIO_BLOCKING_STAGES) && zio->io_vd == NULL && 1674 zio_taskq_member(zio, ZIO_TASKQ_INTERRUPT)) { 1675 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ? 1676 zio_requeue_io_start_cut_in_line : B_FALSE; 1677 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut); 1678 return; 1679 } 1680 1681 zio->io_stage = stage; 1682 zio->io_pipeline_trace |= zio->io_stage; 1683 rv = zio_pipeline[highbit64(stage) - 1](zio); 1684 1685 if (rv == ZIO_PIPELINE_STOP) 1686 return; 1687 1688 ASSERT(rv == ZIO_PIPELINE_CONTINUE); 1689 } 1690} 1691 1692/* 1693 * ========================================================================== 1694 * Initiate I/O, either sync or async 1695 * ========================================================================== 1696 */ 1697int 1698zio_wait(zio_t *zio) 1699{ 1700 int error; 1701 1702 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 1703 ASSERT(zio->io_executor == NULL); 1704 1705 zio->io_waiter = curthread; 1706 ASSERT0(zio->io_queued_timestamp); 1707 zio->io_queued_timestamp = gethrtime(); 1708 1709 zio_execute(zio); 1710 1711 mutex_enter(&zio->io_lock); 1712 while (zio->io_executor != NULL) 1713 cv_wait(&zio->io_cv, &zio->io_lock); 1714 mutex_exit(&zio->io_lock); 1715 1716 error = zio->io_error; 1717 zio_destroy(zio); 1718 1719 return (error); 1720} 1721 1722void 1723zio_nowait(zio_t *zio) 1724{ 1725 ASSERT(zio->io_executor == NULL); 1726 1727 if (zio->io_child_type == ZIO_CHILD_LOGICAL && 1728 zio_unique_parent(zio) == NULL) { 1729 /* 1730 * This is a logical async I/O with no parent to wait for it. 1731 * We add it to the spa_async_root_zio "Godfather" I/O which 1732 * will ensure they complete prior to unloading the pool. 1733 */ 1734 spa_t *spa = zio->io_spa; 1735 1736 zio_add_child(spa->spa_async_zio_root[CPU_SEQID], zio); 1737 } 1738 1739 ASSERT0(zio->io_queued_timestamp); 1740 zio->io_queued_timestamp = gethrtime(); 1741 zio_execute(zio); 1742} 1743 1744/* 1745 * ========================================================================== 1746 * Reexecute or suspend/resume failed I/O 1747 * ========================================================================== 1748 */ 1749 1750static void 1751zio_reexecute(zio_t *pio) 1752{ 1753 zio_t *cio, *cio_next; 1754 1755 ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL); 1756 ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN); 1757 ASSERT(pio->io_gang_leader == NULL); 1758 ASSERT(pio->io_gang_tree == NULL); 1759 1760 pio->io_flags = pio->io_orig_flags; 1761 pio->io_stage = pio->io_orig_stage; 1762 pio->io_pipeline = pio->io_orig_pipeline; 1763 pio->io_reexecute = 0; 1764 pio->io_flags |= ZIO_FLAG_REEXECUTED; 1765 pio->io_pipeline_trace = 0; 1766 pio->io_error = 0; 1767 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1768 pio->io_state[w] = 0; 1769 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 1770 pio->io_child_error[c] = 0; 1771 1772 if (IO_IS_ALLOCATING(pio)) 1773 BP_ZERO(pio->io_bp); 1774 1775 /* 1776 * As we reexecute pio's children, new children could be created. 1777 * New children go to the head of pio's io_child_list, however, 1778 * so we will (correctly) not reexecute them. The key is that 1779 * the remainder of pio's io_child_list, from 'cio_next' onward, 1780 * cannot be affected by any side effects of reexecuting 'cio'. 1781 */ 1782 zio_link_t *zl = NULL; 1783 for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) { 1784 cio_next = zio_walk_children(pio, &zl); 1785 mutex_enter(&pio->io_lock); 1786 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1787 pio->io_children[cio->io_child_type][w]++; 1788 mutex_exit(&pio->io_lock); 1789 zio_reexecute(cio); 1790 } 1791 1792 /* 1793 * Now that all children have been reexecuted, execute the parent. 1794 * We don't reexecute "The Godfather" I/O here as it's the 1795 * responsibility of the caller to wait on him. 1796 */ 1797 if (!(pio->io_flags & ZIO_FLAG_GODFATHER)) { 1798 pio->io_queued_timestamp = gethrtime(); 1799 zio_execute(pio); 1800 } 1801} 1802 1803void 1804zio_suspend(spa_t *spa, zio_t *zio) 1805{ 1806 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC) 1807 fm_panic("Pool '%s' has encountered an uncorrectable I/O " 1808 "failure and the failure mode property for this pool " 1809 "is set to panic.", spa_name(spa)); 1810 1811 zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL, NULL, 0, 0); 1812 1813 mutex_enter(&spa->spa_suspend_lock); 1814 1815 if (spa->spa_suspend_zio_root == NULL) 1816 spa->spa_suspend_zio_root = zio_root(spa, NULL, NULL, 1817 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | 1818 ZIO_FLAG_GODFATHER); 1819 1820 spa->spa_suspended = B_TRUE; 1821 1822 if (zio != NULL) { 1823 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 1824 ASSERT(zio != spa->spa_suspend_zio_root); 1825 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1826 ASSERT(zio_unique_parent(zio) == NULL); 1827 ASSERT(zio->io_stage == ZIO_STAGE_DONE); 1828 zio_add_child(spa->spa_suspend_zio_root, zio); 1829 } 1830 1831 mutex_exit(&spa->spa_suspend_lock); 1832} 1833 1834int 1835zio_resume(spa_t *spa) 1836{ 1837 zio_t *pio; 1838 1839 /* 1840 * Reexecute all previously suspended i/o. 1841 */ 1842 mutex_enter(&spa->spa_suspend_lock); 1843 spa->spa_suspended = B_FALSE; 1844 cv_broadcast(&spa->spa_suspend_cv); 1845 pio = spa->spa_suspend_zio_root; 1846 spa->spa_suspend_zio_root = NULL; 1847 mutex_exit(&spa->spa_suspend_lock); 1848 1849 if (pio == NULL) 1850 return (0); 1851 1852 zio_reexecute(pio); 1853 return (zio_wait(pio)); 1854} 1855 1856void 1857zio_resume_wait(spa_t *spa) 1858{ 1859 mutex_enter(&spa->spa_suspend_lock); 1860 while (spa_suspended(spa)) 1861 cv_wait(&spa->spa_suspend_cv, &spa->spa_suspend_lock); 1862 mutex_exit(&spa->spa_suspend_lock); 1863} 1864 1865/* 1866 * ========================================================================== 1867 * Gang blocks. 1868 * 1869 * A gang block is a collection of small blocks that looks to the DMU 1870 * like one large block. When zio_dva_allocate() cannot find a block 1871 * of the requested size, due to either severe fragmentation or the pool 1872 * being nearly full, it calls zio_write_gang_block() to construct the 1873 * block from smaller fragments. 1874 * 1875 * A gang block consists of a gang header (zio_gbh_phys_t) and up to 1876 * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like 1877 * an indirect block: it's an array of block pointers. It consumes 1878 * only one sector and hence is allocatable regardless of fragmentation. 1879 * The gang header's bps point to its gang members, which hold the data. 1880 * 1881 * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg> 1882 * as the verifier to ensure uniqueness of the SHA256 checksum. 1883 * Critically, the gang block bp's blk_cksum is the checksum of the data, 1884 * not the gang header. This ensures that data block signatures (needed for 1885 * deduplication) are independent of how the block is physically stored. 1886 * 1887 * Gang blocks can be nested: a gang member may itself be a gang block. 1888 * Thus every gang block is a tree in which root and all interior nodes are 1889 * gang headers, and the leaves are normal blocks that contain user data. 1890 * The root of the gang tree is called the gang leader. 1891 * 1892 * To perform any operation (read, rewrite, free, claim) on a gang block, 1893 * zio_gang_assemble() first assembles the gang tree (minus data leaves) 1894 * in the io_gang_tree field of the original logical i/o by recursively 1895 * reading the gang leader and all gang headers below it. This yields 1896 * an in-core tree containing the contents of every gang header and the 1897 * bps for every constituent of the gang block. 1898 * 1899 * With the gang tree now assembled, zio_gang_issue() just walks the gang tree 1900 * and invokes a callback on each bp. To free a gang block, zio_gang_issue() 1901 * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp. 1902 * zio_claim_gang() provides a similarly trivial wrapper for zio_claim(). 1903 * zio_read_gang() is a wrapper around zio_read() that omits reading gang 1904 * headers, since we already have those in io_gang_tree. zio_rewrite_gang() 1905 * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite() 1906 * of the gang header plus zio_checksum_compute() of the data to update the 1907 * gang header's blk_cksum as described above. 1908 * 1909 * The two-phase assemble/issue model solves the problem of partial failure -- 1910 * what if you'd freed part of a gang block but then couldn't read the 1911 * gang header for another part? Assembling the entire gang tree first 1912 * ensures that all the necessary gang header I/O has succeeded before 1913 * starting the actual work of free, claim, or write. Once the gang tree 1914 * is assembled, free and claim are in-memory operations that cannot fail. 1915 * 1916 * In the event that a gang write fails, zio_dva_unallocate() walks the 1917 * gang tree to immediately free (i.e. insert back into the space map) 1918 * everything we've allocated. This ensures that we don't get ENOSPC 1919 * errors during repeated suspend/resume cycles due to a flaky device. 1920 * 1921 * Gang rewrites only happen during sync-to-convergence. If we can't assemble 1922 * the gang tree, we won't modify the block, so we can safely defer the free 1923 * (knowing that the block is still intact). If we *can* assemble the gang 1924 * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free 1925 * each constituent bp and we can allocate a new block on the next sync pass. 1926 * 1927 * In all cases, the gang tree allows complete recovery from partial failure. 1928 * ========================================================================== 1929 */ 1930 1931static zio_t * 1932zio_read_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1933{ 1934 if (gn != NULL) 1935 return (pio); 1936 1937 return (zio_read(pio, pio->io_spa, bp, data, BP_GET_PSIZE(bp), 1938 NULL, NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 1939 &pio->io_bookmark)); 1940} 1941 1942zio_t * 1943zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1944{ 1945 zio_t *zio; 1946 1947 if (gn != NULL) { 1948 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1949 gn->gn_gbh, SPA_GANGBLOCKSIZE, NULL, NULL, pio->io_priority, 1950 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1951 /* 1952 * As we rewrite each gang header, the pipeline will compute 1953 * a new gang block header checksum for it; but no one will 1954 * compute a new data checksum, so we do that here. The one 1955 * exception is the gang leader: the pipeline already computed 1956 * its data checksum because that stage precedes gang assembly. 1957 * (Presently, nothing actually uses interior data checksums; 1958 * this is just good hygiene.) 1959 */ 1960 if (gn != pio->io_gang_leader->io_gang_tree) { 1961 zio_checksum_compute(zio, BP_GET_CHECKSUM(bp), 1962 data, BP_GET_PSIZE(bp)); 1963 } 1964 /* 1965 * If we are here to damage data for testing purposes, 1966 * leave the GBH alone so that we can detect the damage. 1967 */ 1968 if (pio->io_gang_leader->io_flags & ZIO_FLAG_INDUCE_DAMAGE) 1969 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 1970 } else { 1971 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1972 data, BP_GET_PSIZE(bp), NULL, NULL, pio->io_priority, 1973 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1974 } 1975 1976 return (zio); 1977} 1978 1979/* ARGSUSED */ 1980zio_t * 1981zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1982{ 1983 return (zio_free_sync(pio, pio->io_spa, pio->io_txg, bp, 1984 BP_IS_GANG(bp) ? SPA_GANGBLOCKSIZE : BP_GET_PSIZE(bp), 1985 ZIO_GANG_CHILD_FLAGS(pio))); 1986} 1987 1988/* ARGSUSED */ 1989zio_t * 1990zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1991{ 1992 return (zio_claim(pio, pio->io_spa, pio->io_txg, bp, 1993 NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio))); 1994} 1995 1996static zio_gang_issue_func_t *zio_gang_issue_func[ZIO_TYPES] = { 1997 NULL, 1998 zio_read_gang, 1999 zio_rewrite_gang, 2000 zio_free_gang, 2001 zio_claim_gang, 2002 NULL 2003}; 2004 2005static void zio_gang_tree_assemble_done(zio_t *zio); 2006 2007static zio_gang_node_t * 2008zio_gang_node_alloc(zio_gang_node_t **gnpp) 2009{ 2010 zio_gang_node_t *gn; 2011 2012 ASSERT(*gnpp == NULL); 2013 2014 gn = kmem_zalloc(sizeof (*gn), KM_SLEEP); 2015 gn->gn_gbh = zio_buf_alloc(SPA_GANGBLOCKSIZE); 2016 *gnpp = gn; 2017 2018 return (gn); 2019} 2020 2021static void 2022zio_gang_node_free(zio_gang_node_t **gnpp) 2023{ 2024 zio_gang_node_t *gn = *gnpp; 2025 2026 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 2027 ASSERT(gn->gn_child[g] == NULL); 2028 2029 zio_buf_free(gn->gn_gbh, SPA_GANGBLOCKSIZE); 2030 kmem_free(gn, sizeof (*gn)); 2031 *gnpp = NULL; 2032} 2033 2034static void 2035zio_gang_tree_free(zio_gang_node_t **gnpp) 2036{ 2037 zio_gang_node_t *gn = *gnpp; 2038 2039 if (gn == NULL) 2040 return; 2041 2042 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 2043 zio_gang_tree_free(&gn->gn_child[g]); 2044 2045 zio_gang_node_free(gnpp); 2046} 2047 2048static void 2049zio_gang_tree_assemble(zio_t *gio, blkptr_t *bp, zio_gang_node_t **gnpp) 2050{ 2051 zio_gang_node_t *gn = zio_gang_node_alloc(gnpp); 2052 2053 ASSERT(gio->io_gang_leader == gio); 2054 ASSERT(BP_IS_GANG(bp)); 2055 2056 zio_nowait(zio_read(gio, gio->io_spa, bp, gn->gn_gbh, 2057 SPA_GANGBLOCKSIZE, zio_gang_tree_assemble_done, gn, 2058 gio->io_priority, ZIO_GANG_CHILD_FLAGS(gio), &gio->io_bookmark)); 2059} 2060 2061static void 2062zio_gang_tree_assemble_done(zio_t *zio) 2063{ 2064 zio_t *gio = zio->io_gang_leader; 2065 zio_gang_node_t *gn = zio->io_private; 2066 blkptr_t *bp = zio->io_bp; 2067 2068 ASSERT(gio == zio_unique_parent(zio)); 2069 ASSERT(zio->io_child_count == 0); 2070 2071 if (zio->io_error) 2072 return; 2073 2074 if (BP_SHOULD_BYTESWAP(bp)) 2075 byteswap_uint64_array(zio->io_data, zio->io_size); 2076 2077 ASSERT(zio->io_data == gn->gn_gbh); 2078 ASSERT(zio->io_size == SPA_GANGBLOCKSIZE); 2079 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 2080 2081 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 2082 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 2083 if (!BP_IS_GANG(gbp)) 2084 continue; 2085 zio_gang_tree_assemble(gio, gbp, &gn->gn_child[g]); 2086 } 2087} 2088 2089static void 2090zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, void *data) 2091{ 2092 zio_t *gio = pio->io_gang_leader; 2093 zio_t *zio; 2094 2095 ASSERT(BP_IS_GANG(bp) == !!gn); 2096 ASSERT(BP_GET_CHECKSUM(bp) == BP_GET_CHECKSUM(gio->io_bp)); 2097 ASSERT(BP_GET_LSIZE(bp) == BP_GET_PSIZE(bp) || gn == gio->io_gang_tree); 2098 2099 /* 2100 * If you're a gang header, your data is in gn->gn_gbh. 2101 * If you're a gang member, your data is in 'data' and gn == NULL. 2102 */ 2103 zio = zio_gang_issue_func[gio->io_type](pio, bp, gn, data); 2104 2105 if (gn != NULL) { 2106 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 2107 2108 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 2109 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 2110 if (BP_IS_HOLE(gbp)) 2111 continue; 2112 zio_gang_tree_issue(zio, gn->gn_child[g], gbp, data); 2113 data = (char *)data + BP_GET_PSIZE(gbp); 2114 } 2115 } 2116 2117 if (gn == gio->io_gang_tree && gio->io_data != NULL) 2118 ASSERT3P((char *)gio->io_data + gio->io_size, ==, data); 2119 2120 if (zio != pio) 2121 zio_nowait(zio); 2122} 2123 2124static int 2125zio_gang_assemble(zio_t *zio) 2126{ 2127 blkptr_t *bp = zio->io_bp; 2128 2129 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == NULL); 2130 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2131 2132 zio->io_gang_leader = zio; 2133 2134 zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree); 2135 2136 return (ZIO_PIPELINE_CONTINUE); 2137} 2138 2139static int 2140zio_gang_issue(zio_t *zio) 2141{ 2142 blkptr_t *bp = zio->io_bp; 2143 2144 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE)) 2145 return (ZIO_PIPELINE_STOP); 2146 2147 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio); 2148 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2149 2150 if (zio->io_child_error[ZIO_CHILD_GANG] == 0) 2151 zio_gang_tree_issue(zio, zio->io_gang_tree, bp, zio->io_data); 2152 else 2153 zio_gang_tree_free(&zio->io_gang_tree); 2154 2155 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2156 2157 return (ZIO_PIPELINE_CONTINUE); 2158} 2159 2160static void 2161zio_write_gang_member_ready(zio_t *zio) 2162{ 2163 zio_t *pio = zio_unique_parent(zio); 2164 zio_t *gio = zio->io_gang_leader; 2165 dva_t *cdva = zio->io_bp->blk_dva; 2166 dva_t *pdva = pio->io_bp->blk_dva; 2167 uint64_t asize; 2168 2169 if (BP_IS_HOLE(zio->io_bp)) 2170 return; 2171 2172 ASSERT(BP_IS_HOLE(&zio->io_bp_orig)); 2173 2174 ASSERT(zio->io_child_type == ZIO_CHILD_GANG); 2175 ASSERT3U(zio->io_prop.zp_copies, ==, gio->io_prop.zp_copies); 2176 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp)); 2177 ASSERT3U(pio->io_prop.zp_copies, <=, BP_GET_NDVAS(pio->io_bp)); 2178 ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp)); 2179 2180 mutex_enter(&pio->io_lock); 2181 for (int d = 0; d < BP_GET_NDVAS(zio->io_bp); d++) { 2182 ASSERT(DVA_GET_GANG(&pdva[d])); 2183 asize = DVA_GET_ASIZE(&pdva[d]); 2184 asize += DVA_GET_ASIZE(&cdva[d]); 2185 DVA_SET_ASIZE(&pdva[d], asize); 2186 } 2187 mutex_exit(&pio->io_lock); 2188} 2189 2190static int 2191zio_write_gang_block(zio_t *pio) 2192{ 2193 spa_t *spa = pio->io_spa; 2194 metaslab_class_t *mc = spa_normal_class(spa); 2195 blkptr_t *bp = pio->io_bp; 2196 zio_t *gio = pio->io_gang_leader; 2197 zio_t *zio; 2198 zio_gang_node_t *gn, **gnpp; 2199 zio_gbh_phys_t *gbh; 2200 uint64_t txg = pio->io_txg; 2201 uint64_t resid = pio->io_size; 2202 uint64_t lsize; 2203 int copies = gio->io_prop.zp_copies; 2204 int gbh_copies = MIN(copies + 1, spa_max_replication(spa)); 2205 zio_prop_t zp; 2206 int error; 2207 2208 int flags = METASLAB_HINTBP_FAVOR | METASLAB_GANG_HEADER; 2209 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 2210 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 2211 ASSERT(!(pio->io_flags & ZIO_FLAG_NODATA)); 2212 2213 flags |= METASLAB_ASYNC_ALLOC; 2214 VERIFY(refcount_held(&mc->mc_alloc_slots, pio)); 2215 2216 /* 2217 * The logical zio has already placed a reservation for 2218 * 'copies' allocation slots but gang blocks may require 2219 * additional copies. These additional copies 2220 * (i.e. gbh_copies - copies) are guaranteed to succeed 2221 * since metaslab_class_throttle_reserve() always allows 2222 * additional reservations for gang blocks. 2223 */ 2224 VERIFY(metaslab_class_throttle_reserve(mc, gbh_copies - copies, 2225 pio, flags)); 2226 } 2227 2228 error = metaslab_alloc(spa, mc, SPA_GANGBLOCKSIZE, 2229 bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp, flags, 2230 &pio->io_alloc_list, pio); 2231 if (error) { 2232 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 2233 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 2234 ASSERT(!(pio->io_flags & ZIO_FLAG_NODATA)); 2235 2236 /* 2237 * If we failed to allocate the gang block header then 2238 * we remove any additional allocation reservations that 2239 * we placed here. The original reservation will 2240 * be removed when the logical I/O goes to the ready 2241 * stage. 2242 */ 2243 metaslab_class_throttle_unreserve(mc, 2244 gbh_copies - copies, pio); 2245 } 2246 pio->io_error = error; 2247 return (ZIO_PIPELINE_CONTINUE); 2248 } 2249 2250 if (pio == gio) { 2251 gnpp = &gio->io_gang_tree; 2252 } else { 2253 gnpp = pio->io_private; 2254 ASSERT(pio->io_ready == zio_write_gang_member_ready); 2255 } 2256 2257 gn = zio_gang_node_alloc(gnpp); 2258 gbh = gn->gn_gbh; 2259 bzero(gbh, SPA_GANGBLOCKSIZE); 2260 2261 /* 2262 * Create the gang header. 2263 */ 2264 zio = zio_rewrite(pio, spa, txg, bp, gbh, SPA_GANGBLOCKSIZE, NULL, NULL, 2265 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 2266 2267 /* 2268 * Create and nowait the gang children. 2269 */ 2270 for (int g = 0; resid != 0; resid -= lsize, g++) { 2271 lsize = P2ROUNDUP(resid / (SPA_GBH_NBLKPTRS - g), 2272 SPA_MINBLOCKSIZE); 2273 ASSERT(lsize >= SPA_MINBLOCKSIZE && lsize <= resid); 2274 2275 zp.zp_checksum = gio->io_prop.zp_checksum; 2276 zp.zp_compress = ZIO_COMPRESS_OFF; 2277 zp.zp_type = DMU_OT_NONE; 2278 zp.zp_level = 0; 2279 zp.zp_copies = gio->io_prop.zp_copies; 2280 zp.zp_dedup = B_FALSE; 2281 zp.zp_dedup_verify = B_FALSE; 2282 zp.zp_nopwrite = B_FALSE; 2283 2284 zio_t *cio = zio_write(zio, spa, txg, &gbh->zg_blkptr[g], 2285 (char *)pio->io_data + (pio->io_size - resid), lsize, &zp, 2286 zio_write_gang_member_ready, NULL, NULL, NULL, 2287 &gn->gn_child[g], pio->io_priority, 2288 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 2289 2290 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 2291 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 2292 ASSERT(!(pio->io_flags & ZIO_FLAG_NODATA)); 2293 2294 /* 2295 * Gang children won't throttle but we should 2296 * account for their work, so reserve an allocation 2297 * slot for them here. 2298 */ 2299 VERIFY(metaslab_class_throttle_reserve(mc, 2300 zp.zp_copies, cio, flags)); 2301 } 2302 zio_nowait(cio); 2303 } 2304 2305 /* 2306 * Set pio's pipeline to just wait for zio to finish. 2307 */ 2308 pio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2309 2310 zio_nowait(zio); 2311 2312 return (ZIO_PIPELINE_CONTINUE); 2313} 2314 2315/* 2316 * The zio_nop_write stage in the pipeline determines if allocating a 2317 * new bp is necessary. The nopwrite feature can handle writes in 2318 * either syncing or open context (i.e. zil writes) and as a result is 2319 * mutually exclusive with dedup. 2320 * 2321 * By leveraging a cryptographically secure checksum, such as SHA256, we 2322 * can compare the checksums of the new data and the old to determine if 2323 * allocating a new block is required. Note that our requirements for 2324 * cryptographic strength are fairly weak: there can't be any accidental 2325 * hash collisions, but we don't need to be secure against intentional 2326 * (malicious) collisions. To trigger a nopwrite, you have to be able 2327 * to write the file to begin with, and triggering an incorrect (hash 2328 * collision) nopwrite is no worse than simply writing to the file. 2329 * That said, there are no known attacks against the checksum algorithms 2330 * used for nopwrite, assuming that the salt and the checksums 2331 * themselves remain secret. 2332 */ 2333static int 2334zio_nop_write(zio_t *zio) 2335{ 2336 blkptr_t *bp = zio->io_bp; 2337 blkptr_t *bp_orig = &zio->io_bp_orig; 2338 zio_prop_t *zp = &zio->io_prop; 2339 2340 ASSERT(BP_GET_LEVEL(bp) == 0); 2341 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 2342 ASSERT(zp->zp_nopwrite); 2343 ASSERT(!zp->zp_dedup); 2344 ASSERT(zio->io_bp_override == NULL); 2345 ASSERT(IO_IS_ALLOCATING(zio)); 2346 2347 /* 2348 * Check to see if the original bp and the new bp have matching 2349 * characteristics (i.e. same checksum, compression algorithms, etc). 2350 * If they don't then just continue with the pipeline which will 2351 * allocate a new bp. 2352 */ 2353 if (BP_IS_HOLE(bp_orig) || 2354 !(zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_flags & 2355 ZCHECKSUM_FLAG_NOPWRITE) || 2356 BP_GET_CHECKSUM(bp) != BP_GET_CHECKSUM(bp_orig) || 2357 BP_GET_COMPRESS(bp) != BP_GET_COMPRESS(bp_orig) || 2358 BP_GET_DEDUP(bp) != BP_GET_DEDUP(bp_orig) || 2359 zp->zp_copies != BP_GET_NDVAS(bp_orig)) 2360 return (ZIO_PIPELINE_CONTINUE); 2361 2362 /* 2363 * If the checksums match then reset the pipeline so that we 2364 * avoid allocating a new bp and issuing any I/O. 2365 */ 2366 if (ZIO_CHECKSUM_EQUAL(bp->blk_cksum, bp_orig->blk_cksum)) { 2367 ASSERT(zio_checksum_table[zp->zp_checksum].ci_flags & 2368 ZCHECKSUM_FLAG_NOPWRITE); 2369 ASSERT3U(BP_GET_PSIZE(bp), ==, BP_GET_PSIZE(bp_orig)); 2370 ASSERT3U(BP_GET_LSIZE(bp), ==, BP_GET_LSIZE(bp_orig)); 2371 ASSERT(zp->zp_compress != ZIO_COMPRESS_OFF); 2372 ASSERT(bcmp(&bp->blk_prop, &bp_orig->blk_prop, 2373 sizeof (uint64_t)) == 0); 2374 2375 *bp = *bp_orig; 2376 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2377 zio->io_flags |= ZIO_FLAG_NOPWRITE; 2378 } 2379 2380 return (ZIO_PIPELINE_CONTINUE); 2381} 2382 2383/* 2384 * ========================================================================== 2385 * Dedup 2386 * ========================================================================== 2387 */ 2388static void 2389zio_ddt_child_read_done(zio_t *zio) 2390{ 2391 blkptr_t *bp = zio->io_bp; 2392 ddt_entry_t *dde = zio->io_private; 2393 ddt_phys_t *ddp; 2394 zio_t *pio = zio_unique_parent(zio); 2395 2396 mutex_enter(&pio->io_lock); 2397 ddp = ddt_phys_select(dde, bp); 2398 if (zio->io_error == 0) 2399 ddt_phys_clear(ddp); /* this ddp doesn't need repair */ 2400 if (zio->io_error == 0 && dde->dde_repair_data == NULL) 2401 dde->dde_repair_data = zio->io_data; 2402 else 2403 zio_buf_free(zio->io_data, zio->io_size); 2404 mutex_exit(&pio->io_lock); 2405} 2406 2407static int 2408zio_ddt_read_start(zio_t *zio) 2409{ 2410 blkptr_t *bp = zio->io_bp; 2411 2412 ASSERT(BP_GET_DEDUP(bp)); 2413 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 2414 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2415 2416 if (zio->io_child_error[ZIO_CHILD_DDT]) { 2417 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2418 ddt_entry_t *dde = ddt_repair_start(ddt, bp); 2419 ddt_phys_t *ddp = dde->dde_phys; 2420 ddt_phys_t *ddp_self = ddt_phys_select(dde, bp); 2421 blkptr_t blk; 2422 2423 ASSERT(zio->io_vsd == NULL); 2424 zio->io_vsd = dde; 2425 2426 if (ddp_self == NULL) 2427 return (ZIO_PIPELINE_CONTINUE); 2428 2429 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { 2430 if (ddp->ddp_phys_birth == 0 || ddp == ddp_self) 2431 continue; 2432 ddt_bp_create(ddt->ddt_checksum, &dde->dde_key, ddp, 2433 &blk); 2434 zio_nowait(zio_read(zio, zio->io_spa, &blk, 2435 zio_buf_alloc(zio->io_size), zio->io_size, 2436 zio_ddt_child_read_done, dde, zio->io_priority, 2437 ZIO_DDT_CHILD_FLAGS(zio) | ZIO_FLAG_DONT_PROPAGATE, 2438 &zio->io_bookmark)); 2439 } 2440 return (ZIO_PIPELINE_CONTINUE); 2441 } 2442 2443 zio_nowait(zio_read(zio, zio->io_spa, bp, 2444 zio->io_data, zio->io_size, NULL, NULL, zio->io_priority, 2445 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark)); 2446 2447 return (ZIO_PIPELINE_CONTINUE); 2448} 2449 2450static int 2451zio_ddt_read_done(zio_t *zio) 2452{ 2453 blkptr_t *bp = zio->io_bp; 2454 2455 if (zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE)) 2456 return (ZIO_PIPELINE_STOP); 2457 2458 ASSERT(BP_GET_DEDUP(bp)); 2459 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 2460 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2461 2462 if (zio->io_child_error[ZIO_CHILD_DDT]) { 2463 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2464 ddt_entry_t *dde = zio->io_vsd; 2465 if (ddt == NULL) { 2466 ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE); 2467 return (ZIO_PIPELINE_CONTINUE); 2468 } 2469 if (dde == NULL) { 2470 zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1; 2471 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 2472 return (ZIO_PIPELINE_STOP); 2473 } 2474 if (dde->dde_repair_data != NULL) { 2475 bcopy(dde->dde_repair_data, zio->io_data, zio->io_size); 2476 zio->io_child_error[ZIO_CHILD_DDT] = 0; 2477 } 2478 ddt_repair_done(ddt, dde); 2479 zio->io_vsd = NULL; 2480 } 2481 2482 ASSERT(zio->io_vsd == NULL); 2483 2484 return (ZIO_PIPELINE_CONTINUE); 2485} 2486 2487static boolean_t 2488zio_ddt_collision(zio_t *zio, ddt_t *ddt, ddt_entry_t *dde) 2489{ 2490 spa_t *spa = zio->io_spa; 2491 2492 /* 2493 * Note: we compare the original data, not the transformed data, 2494 * because when zio->io_bp is an override bp, we will not have 2495 * pushed the I/O transforms. That's an important optimization 2496 * because otherwise we'd compress/encrypt all dmu_sync() data twice. 2497 */ 2498 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 2499 zio_t *lio = dde->dde_lead_zio[p]; 2500 2501 if (lio != NULL) { 2502 return (lio->io_orig_size != zio->io_orig_size || 2503 bcmp(zio->io_orig_data, lio->io_orig_data, 2504 zio->io_orig_size) != 0); 2505 } 2506 } 2507 2508 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 2509 ddt_phys_t *ddp = &dde->dde_phys[p]; 2510 2511 if (ddp->ddp_phys_birth != 0) { 2512 arc_buf_t *abuf = NULL; 2513 arc_flags_t aflags = ARC_FLAG_WAIT; 2514 blkptr_t blk = *zio->io_bp; 2515 int error; 2516 2517 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth); 2518 2519 ddt_exit(ddt); 2520 2521 error = arc_read(NULL, spa, &blk, 2522 arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ, 2523 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, 2524 &aflags, &zio->io_bookmark); 2525 2526 if (error == 0) { 2527 if (arc_buf_size(abuf) != zio->io_orig_size || 2528 bcmp(abuf->b_data, zio->io_orig_data, 2529 zio->io_orig_size) != 0) 2530 error = SET_ERROR(EEXIST); 2531 arc_buf_destroy(abuf, &abuf); 2532 } 2533 2534 ddt_enter(ddt); 2535 return (error != 0); 2536 } 2537 } 2538 2539 return (B_FALSE); 2540} 2541 2542static void 2543zio_ddt_child_write_ready(zio_t *zio) 2544{ 2545 int p = zio->io_prop.zp_copies; 2546 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 2547 ddt_entry_t *dde = zio->io_private; 2548 ddt_phys_t *ddp = &dde->dde_phys[p]; 2549 zio_t *pio; 2550 2551 if (zio->io_error) 2552 return; 2553 2554 ddt_enter(ddt); 2555 2556 ASSERT(dde->dde_lead_zio[p] == zio); 2557 2558 ddt_phys_fill(ddp, zio->io_bp); 2559 2560 zio_link_t *zl = NULL; 2561 while ((pio = zio_walk_parents(zio, &zl)) != NULL) 2562 ddt_bp_fill(ddp, pio->io_bp, zio->io_txg); 2563 2564 ddt_exit(ddt); 2565} 2566 2567static void 2568zio_ddt_child_write_done(zio_t *zio) 2569{ 2570 int p = zio->io_prop.zp_copies; 2571 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 2572 ddt_entry_t *dde = zio->io_private; 2573 ddt_phys_t *ddp = &dde->dde_phys[p]; 2574 2575 ddt_enter(ddt); 2576 2577 ASSERT(ddp->ddp_refcnt == 0); 2578 ASSERT(dde->dde_lead_zio[p] == zio); 2579 dde->dde_lead_zio[p] = NULL; 2580 2581 if (zio->io_error == 0) { 2582 zio_link_t *zl = NULL; 2583 while (zio_walk_parents(zio, &zl) != NULL) 2584 ddt_phys_addref(ddp); 2585 } else { 2586 ddt_phys_clear(ddp); 2587 } 2588 2589 ddt_exit(ddt); 2590} 2591 2592static void 2593zio_ddt_ditto_write_done(zio_t *zio) 2594{ 2595 int p = DDT_PHYS_DITTO; 2596 zio_prop_t *zp = &zio->io_prop; 2597 blkptr_t *bp = zio->io_bp; 2598 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2599 ddt_entry_t *dde = zio->io_private; 2600 ddt_phys_t *ddp = &dde->dde_phys[p]; 2601 ddt_key_t *ddk = &dde->dde_key; 2602 2603 ddt_enter(ddt); 2604 2605 ASSERT(ddp->ddp_refcnt == 0); 2606 ASSERT(dde->dde_lead_zio[p] == zio); 2607 dde->dde_lead_zio[p] = NULL; 2608 2609 if (zio->io_error == 0) { 2610 ASSERT(ZIO_CHECKSUM_EQUAL(bp->blk_cksum, ddk->ddk_cksum)); 2611 ASSERT(zp->zp_copies < SPA_DVAS_PER_BP); 2612 ASSERT(zp->zp_copies == BP_GET_NDVAS(bp) - BP_IS_GANG(bp)); 2613 if (ddp->ddp_phys_birth != 0) 2614 ddt_phys_free(ddt, ddk, ddp, zio->io_txg); 2615 ddt_phys_fill(ddp, bp); 2616 } 2617 2618 ddt_exit(ddt); 2619} 2620 2621static int 2622zio_ddt_write(zio_t *zio) 2623{ 2624 spa_t *spa = zio->io_spa; 2625 blkptr_t *bp = zio->io_bp; 2626 uint64_t txg = zio->io_txg; 2627 zio_prop_t *zp = &zio->io_prop; 2628 int p = zp->zp_copies; 2629 int ditto_copies; 2630 zio_t *cio = NULL; 2631 zio_t *dio = NULL; 2632 ddt_t *ddt = ddt_select(spa, bp); 2633 ddt_entry_t *dde; 2634 ddt_phys_t *ddp; 2635 2636 ASSERT(BP_GET_DEDUP(bp)); 2637 ASSERT(BP_GET_CHECKSUM(bp) == zp->zp_checksum); 2638 ASSERT(BP_IS_HOLE(bp) || zio->io_bp_override); 2639 2640 ddt_enter(ddt); 2641 dde = ddt_lookup(ddt, bp, B_TRUE); 2642 ddp = &dde->dde_phys[p]; 2643 2644 if (zp->zp_dedup_verify && zio_ddt_collision(zio, ddt, dde)) { 2645 /* 2646 * If we're using a weak checksum, upgrade to a strong checksum 2647 * and try again. If we're already using a strong checksum, 2648 * we can't resolve it, so just convert to an ordinary write. 2649 * (And automatically e-mail a paper to Nature?) 2650 */ 2651 if (!(zio_checksum_table[zp->zp_checksum].ci_flags & 2652 ZCHECKSUM_FLAG_DEDUP)) { 2653 zp->zp_checksum = spa_dedup_checksum(spa); 2654 zio_pop_transforms(zio); 2655 zio->io_stage = ZIO_STAGE_OPEN; 2656 BP_ZERO(bp); 2657 } else { 2658 zp->zp_dedup = B_FALSE; 2659 } 2660 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2661 ddt_exit(ddt); 2662 return (ZIO_PIPELINE_CONTINUE); 2663 } 2664 2665 ditto_copies = ddt_ditto_copies_needed(ddt, dde, ddp); 2666 ASSERT(ditto_copies < SPA_DVAS_PER_BP); 2667 2668 if (ditto_copies > ddt_ditto_copies_present(dde) && 2669 dde->dde_lead_zio[DDT_PHYS_DITTO] == NULL) { 2670 zio_prop_t czp = *zp; 2671 2672 czp.zp_copies = ditto_copies; 2673 2674 /* 2675 * If we arrived here with an override bp, we won't have run 2676 * the transform stack, so we won't have the data we need to 2677 * generate a child i/o. So, toss the override bp and restart. 2678 * This is safe, because using the override bp is just an 2679 * optimization; and it's rare, so the cost doesn't matter. 2680 */ 2681 if (zio->io_bp_override) { 2682 zio_pop_transforms(zio); 2683 zio->io_stage = ZIO_STAGE_OPEN; 2684 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2685 zio->io_bp_override = NULL; 2686 BP_ZERO(bp); 2687 ddt_exit(ddt); 2688 return (ZIO_PIPELINE_CONTINUE); 2689 } 2690 2691 dio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2692 zio->io_orig_size, &czp, NULL, NULL, 2693 NULL, zio_ddt_ditto_write_done, dde, zio->io_priority, 2694 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2695 2696 zio_push_transform(dio, zio->io_data, zio->io_size, 0, NULL); 2697 dde->dde_lead_zio[DDT_PHYS_DITTO] = dio; 2698 } 2699 2700 if (ddp->ddp_phys_birth != 0 || dde->dde_lead_zio[p] != NULL) { 2701 if (ddp->ddp_phys_birth != 0) 2702 ddt_bp_fill(ddp, bp, txg); 2703 if (dde->dde_lead_zio[p] != NULL) 2704 zio_add_child(zio, dde->dde_lead_zio[p]); 2705 else 2706 ddt_phys_addref(ddp); 2707 } else if (zio->io_bp_override) { 2708 ASSERT(bp->blk_birth == txg); 2709 ASSERT(BP_EQUAL(bp, zio->io_bp_override)); 2710 ddt_phys_fill(ddp, bp); 2711 ddt_phys_addref(ddp); 2712 } else { 2713 cio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2714 zio->io_orig_size, zp, 2715 zio_ddt_child_write_ready, NULL, NULL, 2716 zio_ddt_child_write_done, dde, zio->io_priority, 2717 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2718 2719 zio_push_transform(cio, zio->io_data, zio->io_size, 0, NULL); 2720 dde->dde_lead_zio[p] = cio; 2721 } 2722 2723 ddt_exit(ddt); 2724 2725 if (cio) 2726 zio_nowait(cio); 2727 if (dio) 2728 zio_nowait(dio); 2729 2730 return (ZIO_PIPELINE_CONTINUE); 2731} 2732 2733ddt_entry_t *freedde; /* for debugging */ 2734 2735static int 2736zio_ddt_free(zio_t *zio) 2737{ 2738 spa_t *spa = zio->io_spa; 2739 blkptr_t *bp = zio->io_bp; 2740 ddt_t *ddt = ddt_select(spa, bp); 2741 ddt_entry_t *dde; 2742 ddt_phys_t *ddp; 2743 2744 ASSERT(BP_GET_DEDUP(bp)); 2745 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2746 2747 ddt_enter(ddt); 2748 freedde = dde = ddt_lookup(ddt, bp, B_TRUE); 2749 ddp = ddt_phys_select(dde, bp); 2750 ddt_phys_decref(ddp); 2751 ddt_exit(ddt); 2752 2753 return (ZIO_PIPELINE_CONTINUE); 2754} 2755 2756/* 2757 * ========================================================================== 2758 * Allocate and free blocks 2759 * ========================================================================== 2760 */ 2761 2762static zio_t * 2763zio_io_to_allocate(spa_t *spa) 2764{ 2765 zio_t *zio; 2766 2767 ASSERT(MUTEX_HELD(&spa->spa_alloc_lock)); 2768 2769 zio = avl_first(&spa->spa_alloc_tree); 2770 if (zio == NULL) 2771 return (NULL); 2772 2773 ASSERT(IO_IS_ALLOCATING(zio)); 2774 2775 /* 2776 * Try to place a reservation for this zio. If we're unable to 2777 * reserve then we throttle. 2778 */ 2779 if (!metaslab_class_throttle_reserve(spa_normal_class(spa), 2780 zio->io_prop.zp_copies, zio, 0)) { 2781 return (NULL); 2782 } 2783 2784 avl_remove(&spa->spa_alloc_tree, zio); 2785 ASSERT3U(zio->io_stage, <, ZIO_STAGE_DVA_ALLOCATE); 2786 2787 return (zio); 2788} 2789 2790static int 2791zio_dva_throttle(zio_t *zio) 2792{ 2793 spa_t *spa = zio->io_spa; 2794 zio_t *nio; 2795 2796 if (zio->io_priority == ZIO_PRIORITY_SYNC_WRITE || 2797 !spa_normal_class(zio->io_spa)->mc_alloc_throttle_enabled || 2798 zio->io_child_type == ZIO_CHILD_GANG || 2799 zio->io_flags & ZIO_FLAG_NODATA) { 2800 return (ZIO_PIPELINE_CONTINUE); 2801 } 2802 2803 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2804 2805 ASSERT3U(zio->io_queued_timestamp, >, 0); 2806 ASSERT(zio->io_stage == ZIO_STAGE_DVA_THROTTLE); 2807 2808 mutex_enter(&spa->spa_alloc_lock); 2809 2810 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 2811 avl_add(&spa->spa_alloc_tree, zio); 2812 2813 nio = zio_io_to_allocate(zio->io_spa); 2814 mutex_exit(&spa->spa_alloc_lock); 2815 2816 if (nio == zio) 2817 return (ZIO_PIPELINE_CONTINUE); 2818 2819 if (nio != NULL) { 2820 ASSERT3U(nio->io_queued_timestamp, <=, 2821 zio->io_queued_timestamp); 2822 ASSERT(nio->io_stage == ZIO_STAGE_DVA_THROTTLE); 2823 /* 2824 * We are passing control to a new zio so make sure that 2825 * it is processed by a different thread. We do this to 2826 * avoid stack overflows that can occur when parents are 2827 * throttled and children are making progress. We allow 2828 * it to go to the head of the taskq since it's already 2829 * been waiting. 2830 */ 2831 zio_taskq_dispatch(nio, ZIO_TASKQ_ISSUE, B_TRUE); 2832 } 2833 return (ZIO_PIPELINE_STOP); 2834} 2835 2836void 2837zio_allocate_dispatch(spa_t *spa) 2838{ 2839 zio_t *zio; 2840 2841 mutex_enter(&spa->spa_alloc_lock); 2842 zio = zio_io_to_allocate(spa); 2843 mutex_exit(&spa->spa_alloc_lock); 2844 if (zio == NULL) 2845 return; 2846 2847 ASSERT3U(zio->io_stage, ==, ZIO_STAGE_DVA_THROTTLE); 2848 ASSERT0(zio->io_error); 2849 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_TRUE); 2850} 2851 2852static int 2853zio_dva_allocate(zio_t *zio) 2854{ 2855 spa_t *spa = zio->io_spa; 2856 metaslab_class_t *mc = spa_normal_class(spa); 2857 blkptr_t *bp = zio->io_bp; 2858 int error; 2859 int flags = 0; 2860 2861 if (zio->io_gang_leader == NULL) { 2862 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2863 zio->io_gang_leader = zio; 2864 } 2865 2866 ASSERT(BP_IS_HOLE(bp)); 2867 ASSERT0(BP_GET_NDVAS(bp)); 2868 ASSERT3U(zio->io_prop.zp_copies, >, 0); 2869 ASSERT3U(zio->io_prop.zp_copies, <=, spa_max_replication(spa)); 2870 ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp)); 2871 2872 if (zio->io_flags & ZIO_FLAG_NODATA) { 2873 flags |= METASLAB_DONT_THROTTLE; 2874 } 2875 if (zio->io_flags & ZIO_FLAG_GANG_CHILD) { 2876 flags |= METASLAB_GANG_CHILD; 2877 } 2878 if (zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE) { 2879 flags |= METASLAB_ASYNC_ALLOC; 2880 } 2881 2882 error = metaslab_alloc(spa, mc, zio->io_size, bp, 2883 zio->io_prop.zp_copies, zio->io_txg, NULL, flags, 2884 &zio->io_alloc_list, zio); 2885 2886 if (error != 0) { 2887 spa_dbgmsg(spa, "%s: metaslab allocation failure: zio %p, " 2888 "size %llu, error %d", spa_name(spa), zio, zio->io_size, 2889 error); 2890 if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE) 2891 return (zio_write_gang_block(zio)); 2892 zio->io_error = error; 2893 } 2894 2895 return (ZIO_PIPELINE_CONTINUE); 2896} 2897 2898static int 2899zio_dva_free(zio_t *zio) 2900{ 2901 metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE); 2902 2903 return (ZIO_PIPELINE_CONTINUE); 2904} 2905 2906static int 2907zio_dva_claim(zio_t *zio) 2908{ 2909 int error; 2910 2911 error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg); 2912 if (error) 2913 zio->io_error = error; 2914 2915 return (ZIO_PIPELINE_CONTINUE); 2916} 2917 2918/* 2919 * Undo an allocation. This is used by zio_done() when an I/O fails 2920 * and we want to give back the block we just allocated. 2921 * This handles both normal blocks and gang blocks. 2922 */ 2923static void 2924zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp) 2925{ 2926 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp)); 2927 ASSERT(zio->io_bp_override == NULL); 2928 2929 if (!BP_IS_HOLE(bp)) 2930 metaslab_free(zio->io_spa, bp, bp->blk_birth, B_TRUE); 2931 2932 if (gn != NULL) { 2933 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 2934 zio_dva_unallocate(zio, gn->gn_child[g], 2935 &gn->gn_gbh->zg_blkptr[g]); 2936 } 2937 } 2938} 2939 2940/* 2941 * Try to allocate an intent log block. Return 0 on success, errno on failure. 2942 */ 2943int 2944zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp, blkptr_t *old_bp, 2945 uint64_t size, boolean_t *slog) 2946{ 2947 int error = 1; 2948 zio_alloc_list_t io_alloc_list; 2949 2950 ASSERT(txg > spa_syncing_txg(spa)); 2951 2952 metaslab_trace_init(&io_alloc_list); 2953 error = metaslab_alloc(spa, spa_log_class(spa), size, new_bp, 1, 2954 txg, old_bp, METASLAB_HINTBP_AVOID, &io_alloc_list, NULL); 2955 if (error == 0) { 2956 *slog = TRUE; 2957 } else { 2958 error = metaslab_alloc(spa, spa_normal_class(spa), size, 2959 new_bp, 1, txg, old_bp, METASLAB_HINTBP_AVOID, 2960 &io_alloc_list, NULL); 2961 if (error == 0) 2962 *slog = FALSE; 2963 } 2964 metaslab_trace_fini(&io_alloc_list); 2965 2966 if (error == 0) { 2967 BP_SET_LSIZE(new_bp, size); 2968 BP_SET_PSIZE(new_bp, size); 2969 BP_SET_COMPRESS(new_bp, ZIO_COMPRESS_OFF); 2970 BP_SET_CHECKSUM(new_bp, 2971 spa_version(spa) >= SPA_VERSION_SLIM_ZIL 2972 ? ZIO_CHECKSUM_ZILOG2 : ZIO_CHECKSUM_ZILOG); 2973 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG); 2974 BP_SET_LEVEL(new_bp, 0); 2975 BP_SET_DEDUP(new_bp, 0); 2976 BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER); 2977 } 2978 2979 return (error); 2980} 2981 2982/* 2983 * Free an intent log block. 2984 */ 2985void 2986zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp) 2987{ 2988 ASSERT(BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG); 2989 ASSERT(!BP_IS_GANG(bp)); 2990 2991 zio_free(spa, txg, bp); 2992} 2993 2994/* 2995 * ========================================================================== 2996 * Read, write and delete to physical devices 2997 * ========================================================================== 2998 */ 2999 3000 3001/* 3002 * Issue an I/O to the underlying vdev. Typically the issue pipeline 3003 * stops after this stage and will resume upon I/O completion. 3004 * However, there are instances where the vdev layer may need to 3005 * continue the pipeline when an I/O was not issued. Since the I/O 3006 * that was sent to the vdev layer might be different than the one 3007 * currently active in the pipeline (see vdev_queue_io()), we explicitly 3008 * force the underlying vdev layers to call either zio_execute() or 3009 * zio_interrupt() to ensure that the pipeline continues with the correct I/O. 3010 */ 3011static int 3012zio_vdev_io_start(zio_t *zio) 3013{ 3014 vdev_t *vd = zio->io_vd; 3015 uint64_t align; 3016 spa_t *spa = zio->io_spa; 3017 int ret; 3018 3019 ASSERT(zio->io_error == 0); 3020 ASSERT(zio->io_child_error[ZIO_CHILD_VDEV] == 0); 3021 3022 if (vd == NULL) { 3023 if (!(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 3024 spa_config_enter(spa, SCL_ZIO, zio, RW_READER); 3025 3026 /* 3027 * The mirror_ops handle multiple DVAs in a single BP. 3028 */ 3029 vdev_mirror_ops.vdev_op_io_start(zio); 3030 return (ZIO_PIPELINE_STOP); 3031 } 3032 3033 if (vd->vdev_ops->vdev_op_leaf && zio->io_type == ZIO_TYPE_FREE && 3034 zio->io_priority == ZIO_PRIORITY_NOW) { 3035 trim_map_free(vd, zio->io_offset, zio->io_size, zio->io_txg); 3036 return (ZIO_PIPELINE_CONTINUE); 3037 } 3038 3039 ASSERT3P(zio->io_logical, !=, zio); 3040 3041 /* 3042 * We keep track of time-sensitive I/Os so that the scan thread 3043 * can quickly react to certain workloads. In particular, we care 3044 * about non-scrubbing, top-level reads and writes with the following 3045 * characteristics: 3046 * - synchronous writes of user data to non-slog devices 3047 * - any reads of user data 3048 * When these conditions are met, adjust the timestamp of spa_last_io 3049 * which allows the scan thread to adjust its workload accordingly. 3050 */ 3051 if (!(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && zio->io_bp != NULL && 3052 vd == vd->vdev_top && !vd->vdev_islog && 3053 zio->io_bookmark.zb_objset != DMU_META_OBJSET && 3054 zio->io_txg != spa_syncing_txg(spa)) { 3055 uint64_t old = spa->spa_last_io; 3056 uint64_t new = ddi_get_lbolt64(); 3057 if (old != new) 3058 (void) atomic_cas_64(&spa->spa_last_io, old, new); 3059 } 3060 3061 align = 1ULL << vd->vdev_top->vdev_ashift; 3062 3063 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL) && 3064 P2PHASE(zio->io_size, align) != 0) { 3065 /* Transform logical writes to be a full physical block size. */ 3066 uint64_t asize = P2ROUNDUP(zio->io_size, align); 3067 char *abuf = NULL; 3068 if (zio->io_type == ZIO_TYPE_READ || 3069 zio->io_type == ZIO_TYPE_WRITE) 3070 abuf = zio_buf_alloc(asize); 3071 ASSERT(vd == vd->vdev_top); 3072 if (zio->io_type == ZIO_TYPE_WRITE) { 3073 bcopy(zio->io_data, abuf, zio->io_size); 3074 bzero(abuf + zio->io_size, asize - zio->io_size); 3075 } 3076 zio_push_transform(zio, abuf, asize, abuf ? asize : 0, 3077 zio_subblock); 3078 } 3079 3080 /* 3081 * If this is not a physical io, make sure that it is properly aligned 3082 * before proceeding. 3083 */ 3084 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL)) { 3085 ASSERT0(P2PHASE(zio->io_offset, align)); 3086 ASSERT0(P2PHASE(zio->io_size, align)); 3087 } else { 3088 /* 3089 * For the physical io we allow alignment 3090 * to a logical block size. 3091 */ 3092 uint64_t log_align = 3093 1ULL << vd->vdev_top->vdev_logical_ashift; 3094 ASSERT0(P2PHASE(zio->io_offset, log_align)); 3095 ASSERT0(P2PHASE(zio->io_size, log_align)); 3096 } 3097 3098 VERIFY(zio->io_type == ZIO_TYPE_READ || spa_writeable(spa)); 3099 3100 /* 3101 * If this is a repair I/O, and there's no self-healing involved -- 3102 * that is, we're just resilvering what we expect to resilver -- 3103 * then don't do the I/O unless zio's txg is actually in vd's DTL. 3104 * This prevents spurious resilvering with nested replication. 3105 * For example, given a mirror of mirrors, (A+B)+(C+D), if only 3106 * A is out of date, we'll read from C+D, then use the data to 3107 * resilver A+B -- but we don't actually want to resilver B, just A. 3108 * The top-level mirror has no way to know this, so instead we just 3109 * discard unnecessary repairs as we work our way down the vdev tree. 3110 * The same logic applies to any form of nested replication: 3111 * ditto + mirror, RAID-Z + replacing, etc. This covers them all. 3112 */ 3113 if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) && 3114 !(zio->io_flags & ZIO_FLAG_SELF_HEAL) && 3115 zio->io_txg != 0 && /* not a delegated i/o */ 3116 !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) { 3117 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 3118 zio_vdev_io_bypass(zio); 3119 return (ZIO_PIPELINE_CONTINUE); 3120 } 3121 3122 if (vd->vdev_ops->vdev_op_leaf) { 3123 switch (zio->io_type) { 3124 case ZIO_TYPE_READ: 3125 if (vdev_cache_read(zio)) 3126 return (ZIO_PIPELINE_CONTINUE); 3127 /* FALLTHROUGH */ 3128 case ZIO_TYPE_WRITE: 3129 case ZIO_TYPE_FREE: 3130 if ((zio = vdev_queue_io(zio)) == NULL) 3131 return (ZIO_PIPELINE_STOP); 3132 3133 if (!vdev_accessible(vd, zio)) { 3134 zio->io_error = SET_ERROR(ENXIO); 3135 zio_interrupt(zio); 3136 return (ZIO_PIPELINE_STOP); 3137 } 3138 break; 3139 } 3140 /* 3141 * Note that we ignore repair writes for TRIM because they can 3142 * conflict with normal writes. This isn't an issue because, by 3143 * definition, we only repair blocks that aren't freed. 3144 */ 3145 if (zio->io_type == ZIO_TYPE_WRITE && 3146 !(zio->io_flags & ZIO_FLAG_IO_REPAIR) && 3147 !trim_map_write_start(zio)) 3148 return (ZIO_PIPELINE_STOP); 3149 } 3150 3151 vd->vdev_ops->vdev_op_io_start(zio); 3152 return (ZIO_PIPELINE_STOP); 3153} 3154 3155static int 3156zio_vdev_io_done(zio_t *zio) 3157{ 3158 vdev_t *vd = zio->io_vd; 3159 vdev_ops_t *ops = vd ? vd->vdev_ops : &vdev_mirror_ops; 3160 boolean_t unexpected_error = B_FALSE; 3161 3162 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 3163 return (ZIO_PIPELINE_STOP); 3164 3165 ASSERT(zio->io_type == ZIO_TYPE_READ || 3166 zio->io_type == ZIO_TYPE_WRITE || zio->io_type == ZIO_TYPE_FREE); 3167 3168 if (vd != NULL && vd->vdev_ops->vdev_op_leaf && 3169 (zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE || 3170 zio->io_type == ZIO_TYPE_FREE)) { 3171 3172 if (zio->io_type == ZIO_TYPE_WRITE && 3173 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) 3174 trim_map_write_done(zio); 3175 3176 vdev_queue_io_done(zio); 3177 3178 if (zio->io_type == ZIO_TYPE_WRITE) 3179 vdev_cache_write(zio); 3180 3181 if (zio_injection_enabled && zio->io_error == 0) 3182 zio->io_error = zio_handle_device_injection(vd, 3183 zio, EIO); 3184 3185 if (zio_injection_enabled && zio->io_error == 0) 3186 zio->io_error = zio_handle_label_injection(zio, EIO); 3187 3188 if (zio->io_error) { 3189 if (zio->io_error == ENOTSUP && 3190 zio->io_type == ZIO_TYPE_FREE) { 3191 /* Not all devices support TRIM. */ 3192 } else if (!vdev_accessible(vd, zio)) { 3193 zio->io_error = SET_ERROR(ENXIO); 3194 } else { 3195 unexpected_error = B_TRUE; 3196 } 3197 } 3198 } 3199 3200 ops->vdev_op_io_done(zio); 3201 3202 if (unexpected_error) 3203 VERIFY(vdev_probe(vd, zio) == NULL); 3204 3205 return (ZIO_PIPELINE_CONTINUE); 3206} 3207 3208/* 3209 * For non-raidz ZIOs, we can just copy aside the bad data read from the 3210 * disk, and use that to finish the checksum ereport later. 3211 */ 3212static void 3213zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr, 3214 const void *good_buf) 3215{ 3216 /* no processing needed */ 3217 zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE); 3218} 3219 3220/*ARGSUSED*/ 3221void 3222zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *ignored) 3223{ 3224 void *buf = zio_buf_alloc(zio->io_size); 3225 3226 bcopy(zio->io_data, buf, zio->io_size); 3227 3228 zcr->zcr_cbinfo = zio->io_size; 3229 zcr->zcr_cbdata = buf; 3230 zcr->zcr_finish = zio_vsd_default_cksum_finish; 3231 zcr->zcr_free = zio_buf_free; 3232} 3233 3234static int 3235zio_vdev_io_assess(zio_t *zio) 3236{ 3237 vdev_t *vd = zio->io_vd; 3238 3239 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 3240 return (ZIO_PIPELINE_STOP); 3241 3242 if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 3243 spa_config_exit(zio->io_spa, SCL_ZIO, zio); 3244 3245 if (zio->io_vsd != NULL) { 3246 zio->io_vsd_ops->vsd_free(zio); 3247 zio->io_vsd = NULL; 3248 } 3249 3250 if (zio_injection_enabled && zio->io_error == 0) 3251 zio->io_error = zio_handle_fault_injection(zio, EIO); 3252 3253 if (zio->io_type == ZIO_TYPE_FREE && 3254 zio->io_priority != ZIO_PRIORITY_NOW) { 3255 switch (zio->io_error) { 3256 case 0: 3257 ZIO_TRIM_STAT_INCR(bytes, zio->io_size); 3258 ZIO_TRIM_STAT_BUMP(success); 3259 break; 3260 case EOPNOTSUPP: 3261 ZIO_TRIM_STAT_BUMP(unsupported); 3262 break; 3263 default: 3264 ZIO_TRIM_STAT_BUMP(failed); 3265 break; 3266 } 3267 } 3268 3269 /* 3270 * If the I/O failed, determine whether we should attempt to retry it. 3271 * 3272 * On retry, we cut in line in the issue queue, since we don't want 3273 * compression/checksumming/etc. work to prevent our (cheap) IO reissue. 3274 */ 3275 if (zio->io_error && vd == NULL && 3276 !(zio->io_flags & (ZIO_FLAG_DONT_RETRY | ZIO_FLAG_IO_RETRY))) { 3277 ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_QUEUE)); /* not a leaf */ 3278 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_BYPASS)); /* not a leaf */ 3279 zio->io_error = 0; 3280 zio->io_flags |= ZIO_FLAG_IO_RETRY | 3281 ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE; 3282 zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1; 3283 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, 3284 zio_requeue_io_start_cut_in_line); 3285 return (ZIO_PIPELINE_STOP); 3286 } 3287 3288 /* 3289 * If we got an error on a leaf device, convert it to ENXIO 3290 * if the device is not accessible at all. 3291 */ 3292 if (zio->io_error && vd != NULL && vd->vdev_ops->vdev_op_leaf && 3293 !vdev_accessible(vd, zio)) 3294 zio->io_error = SET_ERROR(ENXIO); 3295 3296 /* 3297 * If we can't write to an interior vdev (mirror or RAID-Z), 3298 * set vdev_cant_write so that we stop trying to allocate from it. 3299 */ 3300 if (zio->io_error == ENXIO && zio->io_type == ZIO_TYPE_WRITE && 3301 vd != NULL && !vd->vdev_ops->vdev_op_leaf) { 3302 vd->vdev_cant_write = B_TRUE; 3303 } 3304 3305 if (zio->io_error) 3306 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 3307 3308 if (vd != NULL && vd->vdev_ops->vdev_op_leaf && 3309 zio->io_physdone != NULL) { 3310 ASSERT(!(zio->io_flags & ZIO_FLAG_DELEGATED)); 3311 ASSERT(zio->io_child_type == ZIO_CHILD_VDEV); 3312 zio->io_physdone(zio->io_logical); 3313 } 3314 3315 return (ZIO_PIPELINE_CONTINUE); 3316} 3317 3318void 3319zio_vdev_io_reissue(zio_t *zio) 3320{ 3321 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 3322 ASSERT(zio->io_error == 0); 3323 3324 zio->io_stage >>= 1; 3325} 3326 3327void 3328zio_vdev_io_redone(zio_t *zio) 3329{ 3330 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE); 3331 3332 zio->io_stage >>= 1; 3333} 3334 3335void 3336zio_vdev_io_bypass(zio_t *zio) 3337{ 3338 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 3339 ASSERT(zio->io_error == 0); 3340 3341 zio->io_flags |= ZIO_FLAG_IO_BYPASS; 3342 zio->io_stage = ZIO_STAGE_VDEV_IO_ASSESS >> 1; 3343} 3344 3345/* 3346 * ========================================================================== 3347 * Generate and verify checksums 3348 * ========================================================================== 3349 */ 3350static int 3351zio_checksum_generate(zio_t *zio) 3352{ 3353 blkptr_t *bp = zio->io_bp; 3354 enum zio_checksum checksum; 3355 3356 if (bp == NULL) { 3357 /* 3358 * This is zio_write_phys(). 3359 * We're either generating a label checksum, or none at all. 3360 */ 3361 checksum = zio->io_prop.zp_checksum; 3362 3363 if (checksum == ZIO_CHECKSUM_OFF) 3364 return (ZIO_PIPELINE_CONTINUE); 3365 3366 ASSERT(checksum == ZIO_CHECKSUM_LABEL); 3367 } else { 3368 if (BP_IS_GANG(bp) && zio->io_child_type == ZIO_CHILD_GANG) { 3369 ASSERT(!IO_IS_ALLOCATING(zio)); 3370 checksum = ZIO_CHECKSUM_GANG_HEADER; 3371 } else { 3372 checksum = BP_GET_CHECKSUM(bp); 3373 } 3374 } 3375 3376 zio_checksum_compute(zio, checksum, zio->io_data, zio->io_size); 3377 3378 return (ZIO_PIPELINE_CONTINUE); 3379} 3380 3381static int 3382zio_checksum_verify(zio_t *zio) 3383{ 3384 zio_bad_cksum_t info; 3385 blkptr_t *bp = zio->io_bp; 3386 int error; 3387 3388 ASSERT(zio->io_vd != NULL); 3389 3390 if (bp == NULL) { 3391 /* 3392 * This is zio_read_phys(). 3393 * We're either verifying a label checksum, or nothing at all. 3394 */ 3395 if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF) 3396 return (ZIO_PIPELINE_CONTINUE); 3397 3398 ASSERT(zio->io_prop.zp_checksum == ZIO_CHECKSUM_LABEL); 3399 } 3400 3401 if ((error = zio_checksum_error(zio, &info)) != 0) { 3402 zio->io_error = error; 3403 if (error == ECKSUM && 3404 !(zio->io_flags & ZIO_FLAG_SPECULATIVE)) { 3405 zfs_ereport_start_checksum(zio->io_spa, 3406 zio->io_vd, zio, zio->io_offset, 3407 zio->io_size, NULL, &info); 3408 } 3409 } 3410 3411 return (ZIO_PIPELINE_CONTINUE); 3412} 3413 3414/* 3415 * Called by RAID-Z to ensure we don't compute the checksum twice. 3416 */ 3417void 3418zio_checksum_verified(zio_t *zio) 3419{ 3420 zio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 3421} 3422 3423/* 3424 * ========================================================================== 3425 * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other. 3426 * An error of 0 indicates success. ENXIO indicates whole-device failure, 3427 * which may be transient (e.g. unplugged) or permament. ECKSUM and EIO 3428 * indicate errors that are specific to one I/O, and most likely permanent. 3429 * Any other error is presumed to be worse because we weren't expecting it. 3430 * ========================================================================== 3431 */ 3432int 3433zio_worst_error(int e1, int e2) 3434{ 3435 static int zio_error_rank[] = { 0, ENXIO, ECKSUM, EIO }; 3436 int r1, r2; 3437 3438 for (r1 = 0; r1 < sizeof (zio_error_rank) / sizeof (int); r1++) 3439 if (e1 == zio_error_rank[r1]) 3440 break; 3441 3442 for (r2 = 0; r2 < sizeof (zio_error_rank) / sizeof (int); r2++) 3443 if (e2 == zio_error_rank[r2]) 3444 break; 3445 3446 return (r1 > r2 ? e1 : e2); 3447} 3448 3449/* 3450 * ========================================================================== 3451 * I/O completion 3452 * ========================================================================== 3453 */ 3454static int 3455zio_ready(zio_t *zio) 3456{ 3457 blkptr_t *bp = zio->io_bp; 3458 zio_t *pio, *pio_next; 3459 zio_link_t *zl = NULL; 3460 3461 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 3462 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_READY)) 3463 return (ZIO_PIPELINE_STOP); 3464 3465 if (zio->io_ready) { 3466 ASSERT(IO_IS_ALLOCATING(zio)); 3467 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp) || 3468 (zio->io_flags & ZIO_FLAG_NOPWRITE)); 3469 ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0); 3470 3471 zio->io_ready(zio); 3472 } 3473 3474 if (bp != NULL && bp != &zio->io_bp_copy) 3475 zio->io_bp_copy = *bp; 3476 3477 if (zio->io_error != 0) { 3478 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 3479 3480 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 3481 ASSERT(IO_IS_ALLOCATING(zio)); 3482 ASSERT(zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 3483 /* 3484 * We were unable to allocate anything, unreserve and 3485 * issue the next I/O to allocate. 3486 */ 3487 metaslab_class_throttle_unreserve( 3488 spa_normal_class(zio->io_spa), 3489 zio->io_prop.zp_copies, zio); 3490 zio_allocate_dispatch(zio->io_spa); 3491 } 3492 } 3493 3494 mutex_enter(&zio->io_lock); 3495 zio->io_state[ZIO_WAIT_READY] = 1; 3496 pio = zio_walk_parents(zio, &zl); 3497 mutex_exit(&zio->io_lock); 3498 3499 /* 3500 * As we notify zio's parents, new parents could be added. 3501 * New parents go to the head of zio's io_parent_list, however, 3502 * so we will (correctly) not notify them. The remainder of zio's 3503 * io_parent_list, from 'pio_next' onward, cannot change because 3504 * all parents must wait for us to be done before they can be done. 3505 */ 3506 for (; pio != NULL; pio = pio_next) { 3507 pio_next = zio_walk_parents(zio, &zl); 3508 zio_notify_parent(pio, zio, ZIO_WAIT_READY); 3509 } 3510 3511 if (zio->io_flags & ZIO_FLAG_NODATA) { 3512 if (BP_IS_GANG(bp)) { 3513 zio->io_flags &= ~ZIO_FLAG_NODATA; 3514 } else { 3515 ASSERT((uintptr_t)zio->io_data < SPA_MAXBLOCKSIZE); 3516 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 3517 } 3518 } 3519 3520 if (zio_injection_enabled && 3521 zio->io_spa->spa_syncing_txg == zio->io_txg) 3522 zio_handle_ignored_writes(zio); 3523 3524 return (ZIO_PIPELINE_CONTINUE); 3525} 3526 3527/* 3528 * Update the allocation throttle accounting. 3529 */ 3530static void 3531zio_dva_throttle_done(zio_t *zio) 3532{ 3533 zio_t *lio = zio->io_logical; 3534 zio_t *pio = zio_unique_parent(zio); 3535 vdev_t *vd = zio->io_vd; 3536 int flags = METASLAB_ASYNC_ALLOC; 3537 3538 ASSERT3P(zio->io_bp, !=, NULL); 3539 ASSERT3U(zio->io_type, ==, ZIO_TYPE_WRITE); 3540 ASSERT3U(zio->io_priority, ==, ZIO_PRIORITY_ASYNC_WRITE); 3541 ASSERT3U(zio->io_child_type, ==, ZIO_CHILD_VDEV); 3542 ASSERT(vd != NULL); 3543 ASSERT3P(vd, ==, vd->vdev_top); 3544 ASSERT(!(zio->io_flags & (ZIO_FLAG_IO_REPAIR | ZIO_FLAG_IO_RETRY))); 3545 ASSERT(zio->io_flags & ZIO_FLAG_IO_ALLOCATING); 3546 ASSERT(!(lio->io_flags & ZIO_FLAG_IO_REWRITE)); 3547 ASSERT(!(lio->io_orig_flags & ZIO_FLAG_NODATA)); 3548 3549 /* 3550 * Parents of gang children can have two flavors -- ones that 3551 * allocated the gang header (will have ZIO_FLAG_IO_REWRITE set) 3552 * and ones that allocated the constituent blocks. The allocation 3553 * throttle needs to know the allocating parent zio so we must find 3554 * it here. 3555 */ 3556 if (pio->io_child_type == ZIO_CHILD_GANG) { 3557 /* 3558 * If our parent is a rewrite gang child then our grandparent 3559 * would have been the one that performed the allocation. 3560 */ 3561 if (pio->io_flags & ZIO_FLAG_IO_REWRITE) 3562 pio = zio_unique_parent(pio); 3563 flags |= METASLAB_GANG_CHILD; 3564 } 3565 3566 ASSERT(IO_IS_ALLOCATING(pio)); 3567 ASSERT3P(zio, !=, zio->io_logical); 3568 ASSERT(zio->io_logical != NULL); 3569 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REPAIR)); 3570 ASSERT0(zio->io_flags & ZIO_FLAG_NOPWRITE); 3571 3572 mutex_enter(&pio->io_lock); 3573 metaslab_group_alloc_decrement(zio->io_spa, vd->vdev_id, pio, flags); 3574 mutex_exit(&pio->io_lock); 3575 3576 metaslab_class_throttle_unreserve(spa_normal_class(zio->io_spa), 3577 1, pio); 3578 3579 /* 3580 * Call into the pipeline to see if there is more work that 3581 * needs to be done. If there is work to be done it will be 3582 * dispatched to another taskq thread. 3583 */ 3584 zio_allocate_dispatch(zio->io_spa); 3585} 3586 3587static int 3588zio_done(zio_t *zio) 3589{ 3590 spa_t *spa = zio->io_spa; 3591 zio_t *lio = zio->io_logical; 3592 blkptr_t *bp = zio->io_bp; 3593 vdev_t *vd = zio->io_vd; 3594 uint64_t psize = zio->io_size; 3595 zio_t *pio, *pio_next; 3596 metaslab_class_t *mc = spa_normal_class(spa); 3597 zio_link_t *zl = NULL; 3598 3599 /* 3600 * If our children haven't all completed, 3601 * wait for them and then repeat this pipeline stage. 3602 */ 3603 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE) || 3604 zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE) || 3605 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE) || 3606 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_DONE)) 3607 return (ZIO_PIPELINE_STOP); 3608 3609 /* 3610 * If the allocation throttle is enabled, then update the accounting. 3611 * We only track child I/Os that are part of an allocating async 3612 * write. We must do this since the allocation is performed 3613 * by the logical I/O but the actual write is done by child I/Os. 3614 */ 3615 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING && 3616 zio->io_child_type == ZIO_CHILD_VDEV) { 3617 ASSERT(mc->mc_alloc_throttle_enabled); 3618 zio_dva_throttle_done(zio); 3619 } 3620 3621 /* 3622 * If the allocation throttle is enabled, verify that 3623 * we have decremented the refcounts for every I/O that was throttled. 3624 */ 3625 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 3626 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 3627 ASSERT(zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 3628 ASSERT(bp != NULL); 3629 metaslab_group_alloc_verify(spa, zio->io_bp, zio); 3630 VERIFY(refcount_not_held(&mc->mc_alloc_slots, zio)); 3631 } 3632 3633 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 3634 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 3635 ASSERT(zio->io_children[c][w] == 0); 3636 3637 if (bp != NULL && !BP_IS_EMBEDDED(bp)) { 3638 ASSERT(bp->blk_pad[0] == 0); 3639 ASSERT(bp->blk_pad[1] == 0); 3640 ASSERT(bcmp(bp, &zio->io_bp_copy, sizeof (blkptr_t)) == 0 || 3641 (bp == zio_unique_parent(zio)->io_bp)); 3642 if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(bp) && 3643 zio->io_bp_override == NULL && 3644 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) { 3645 ASSERT(!BP_SHOULD_BYTESWAP(bp)); 3646 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(bp)); 3647 ASSERT(BP_COUNT_GANG(bp) == 0 || 3648 (BP_COUNT_GANG(bp) == BP_GET_NDVAS(bp))); 3649 } 3650 if (zio->io_flags & ZIO_FLAG_NOPWRITE) 3651 VERIFY(BP_EQUAL(bp, &zio->io_bp_orig)); 3652 } 3653 3654 /* 3655 * If there were child vdev/gang/ddt errors, they apply to us now. 3656 */ 3657 zio_inherit_child_errors(zio, ZIO_CHILD_VDEV); 3658 zio_inherit_child_errors(zio, ZIO_CHILD_GANG); 3659 zio_inherit_child_errors(zio, ZIO_CHILD_DDT); 3660 3661 /* 3662 * If the I/O on the transformed data was successful, generate any 3663 * checksum reports now while we still have the transformed data. 3664 */ 3665 if (zio->io_error == 0) { 3666 while (zio->io_cksum_report != NULL) { 3667 zio_cksum_report_t *zcr = zio->io_cksum_report; 3668 uint64_t align = zcr->zcr_align; 3669 uint64_t asize = P2ROUNDUP(psize, align); 3670 char *abuf = zio->io_data; 3671 3672 if (asize != psize) { 3673 abuf = zio_buf_alloc(asize); 3674 bcopy(zio->io_data, abuf, psize); 3675 bzero(abuf + psize, asize - psize); 3676 } 3677 3678 zio->io_cksum_report = zcr->zcr_next; 3679 zcr->zcr_next = NULL; 3680 zcr->zcr_finish(zcr, abuf); 3681 zfs_ereport_free_checksum(zcr); 3682 3683 if (asize != psize) 3684 zio_buf_free(abuf, asize); 3685 } 3686 } 3687 3688 zio_pop_transforms(zio); /* note: may set zio->io_error */ 3689 3690 vdev_stat_update(zio, psize); 3691 3692 if (zio->io_error) { 3693 /* 3694 * If this I/O is attached to a particular vdev, 3695 * generate an error message describing the I/O failure 3696 * at the block level. We ignore these errors if the 3697 * device is currently unavailable. 3698 */ 3699 if (zio->io_error != ECKSUM && vd != NULL && !vdev_is_dead(vd)) 3700 zfs_ereport_post(FM_EREPORT_ZFS_IO, spa, vd, zio, 0, 0); 3701 3702 if ((zio->io_error == EIO || !(zio->io_flags & 3703 (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) && 3704 zio == lio) { 3705 /* 3706 * For logical I/O requests, tell the SPA to log the 3707 * error and generate a logical data ereport. 3708 */ 3709 spa_log_error(spa, zio); 3710 zfs_ereport_post(FM_EREPORT_ZFS_DATA, spa, NULL, zio, 3711 0, 0); 3712 } 3713 } 3714 3715 if (zio->io_error && zio == lio) { 3716 /* 3717 * Determine whether zio should be reexecuted. This will 3718 * propagate all the way to the root via zio_notify_parent(). 3719 */ 3720 ASSERT(vd == NULL && bp != NULL); 3721 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3722 3723 if (IO_IS_ALLOCATING(zio) && 3724 !(zio->io_flags & ZIO_FLAG_CANFAIL)) { 3725 if (zio->io_error != ENOSPC) 3726 zio->io_reexecute |= ZIO_REEXECUTE_NOW; 3727 else 3728 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3729 } 3730 3731 if ((zio->io_type == ZIO_TYPE_READ || 3732 zio->io_type == ZIO_TYPE_FREE) && 3733 !(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && 3734 zio->io_error == ENXIO && 3735 spa_load_state(spa) == SPA_LOAD_NONE && 3736 spa_get_failmode(spa) != ZIO_FAILURE_MODE_CONTINUE) 3737 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3738 3739 if (!(zio->io_flags & ZIO_FLAG_CANFAIL) && !zio->io_reexecute) 3740 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3741 3742 /* 3743 * Here is a possibly good place to attempt to do 3744 * either combinatorial reconstruction or error correction 3745 * based on checksums. It also might be a good place 3746 * to send out preliminary ereports before we suspend 3747 * processing. 3748 */ 3749 } 3750 3751 /* 3752 * If there were logical child errors, they apply to us now. 3753 * We defer this until now to avoid conflating logical child 3754 * errors with errors that happened to the zio itself when 3755 * updating vdev stats and reporting FMA events above. 3756 */ 3757 zio_inherit_child_errors(zio, ZIO_CHILD_LOGICAL); 3758 3759 if ((zio->io_error || zio->io_reexecute) && 3760 IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio && 3761 !(zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE))) 3762 zio_dva_unallocate(zio, zio->io_gang_tree, bp); 3763 3764 zio_gang_tree_free(&zio->io_gang_tree); 3765 3766 /* 3767 * Godfather I/Os should never suspend. 3768 */ 3769 if ((zio->io_flags & ZIO_FLAG_GODFATHER) && 3770 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) 3771 zio->io_reexecute = 0; 3772 3773 if (zio->io_reexecute) { 3774 /* 3775 * This is a logical I/O that wants to reexecute. 3776 * 3777 * Reexecute is top-down. When an i/o fails, if it's not 3778 * the root, it simply notifies its parent and sticks around. 3779 * The parent, seeing that it still has children in zio_done(), 3780 * does the same. This percolates all the way up to the root. 3781 * The root i/o will reexecute or suspend the entire tree. 3782 * 3783 * This approach ensures that zio_reexecute() honors 3784 * all the original i/o dependency relationships, e.g. 3785 * parents not executing until children are ready. 3786 */ 3787 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3788 3789 zio->io_gang_leader = NULL; 3790 3791 mutex_enter(&zio->io_lock); 3792 zio->io_state[ZIO_WAIT_DONE] = 1; 3793 mutex_exit(&zio->io_lock); 3794 3795 /* 3796 * "The Godfather" I/O monitors its children but is 3797 * not a true parent to them. It will track them through 3798 * the pipeline but severs its ties whenever they get into 3799 * trouble (e.g. suspended). This allows "The Godfather" 3800 * I/O to return status without blocking. 3801 */ 3802 zl = NULL; 3803 for (pio = zio_walk_parents(zio, &zl); pio != NULL; 3804 pio = pio_next) { 3805 zio_link_t *remove_zl = zl; 3806 pio_next = zio_walk_parents(zio, &zl); 3807 3808 if ((pio->io_flags & ZIO_FLAG_GODFATHER) && 3809 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) { 3810 zio_remove_child(pio, zio, remove_zl); 3811 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3812 } 3813 } 3814 3815 if ((pio = zio_unique_parent(zio)) != NULL) { 3816 /* 3817 * We're not a root i/o, so there's nothing to do 3818 * but notify our parent. Don't propagate errors 3819 * upward since we haven't permanently failed yet. 3820 */ 3821 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 3822 zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE; 3823 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3824 } else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) { 3825 /* 3826 * We'd fail again if we reexecuted now, so suspend 3827 * until conditions improve (e.g. device comes online). 3828 */ 3829 zio_suspend(spa, zio); 3830 } else { 3831 /* 3832 * Reexecution is potentially a huge amount of work. 3833 * Hand it off to the otherwise-unused claim taskq. 3834 */ 3835#if defined(illumos) || !defined(_KERNEL) 3836 ASSERT(zio->io_tqent.tqent_next == NULL); 3837#else 3838 ASSERT(zio->io_tqent.tqent_task.ta_pending == 0); 3839#endif 3840 spa_taskq_dispatch_ent(spa, ZIO_TYPE_CLAIM, 3841 ZIO_TASKQ_ISSUE, (task_func_t *)zio_reexecute, zio, 3842 0, &zio->io_tqent); 3843 } 3844 return (ZIO_PIPELINE_STOP); 3845 } 3846 3847 ASSERT(zio->io_child_count == 0); 3848 ASSERT(zio->io_reexecute == 0); 3849 ASSERT(zio->io_error == 0 || (zio->io_flags & ZIO_FLAG_CANFAIL)); 3850 3851 /* 3852 * Report any checksum errors, since the I/O is complete. 3853 */ 3854 while (zio->io_cksum_report != NULL) { 3855 zio_cksum_report_t *zcr = zio->io_cksum_report; 3856 zio->io_cksum_report = zcr->zcr_next; 3857 zcr->zcr_next = NULL; 3858 zcr->zcr_finish(zcr, NULL); 3859 zfs_ereport_free_checksum(zcr); 3860 } 3861 3862 /* 3863 * It is the responsibility of the done callback to ensure that this 3864 * particular zio is no longer discoverable for adoption, and as 3865 * such, cannot acquire any new parents. 3866 */ 3867 if (zio->io_done) 3868 zio->io_done(zio); 3869 3870 mutex_enter(&zio->io_lock); 3871 zio->io_state[ZIO_WAIT_DONE] = 1; 3872 mutex_exit(&zio->io_lock); 3873 3874 zl = NULL; 3875 for (pio = zio_walk_parents(zio, &zl); pio != NULL; pio = pio_next) { 3876 zio_link_t *remove_zl = zl; 3877 pio_next = zio_walk_parents(zio, &zl); 3878 zio_remove_child(pio, zio, remove_zl); 3879 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3880 } 3881 3882 if (zio->io_waiter != NULL) { 3883 mutex_enter(&zio->io_lock); 3884 zio->io_executor = NULL; 3885 cv_broadcast(&zio->io_cv); 3886 mutex_exit(&zio->io_lock); 3887 } else { 3888 zio_destroy(zio); 3889 } 3890 3891 return (ZIO_PIPELINE_STOP); 3892} 3893 3894/* 3895 * ========================================================================== 3896 * I/O pipeline definition 3897 * ========================================================================== 3898 */ 3899static zio_pipe_stage_t *zio_pipeline[] = { 3900 NULL, 3901 zio_read_bp_init, 3902 zio_write_bp_init, 3903 zio_free_bp_init, 3904 zio_issue_async, 3905 zio_write_compress, 3906 zio_checksum_generate, 3907 zio_nop_write, 3908 zio_ddt_read_start, 3909 zio_ddt_read_done, 3910 zio_ddt_write, 3911 zio_ddt_free, 3912 zio_gang_assemble, 3913 zio_gang_issue, 3914 zio_dva_throttle, 3915 zio_dva_allocate, 3916 zio_dva_free, 3917 zio_dva_claim, 3918 zio_ready, 3919 zio_vdev_io_start, 3920 zio_vdev_io_done, 3921 zio_vdev_io_assess, 3922 zio_checksum_verify, 3923 zio_done 3924}; 3925 3926 3927 3928 3929/* 3930 * Compare two zbookmark_phys_t's to see which we would reach first in a 3931 * pre-order traversal of the object tree. 3932 * 3933 * This is simple in every case aside from the meta-dnode object. For all other 3934 * objects, we traverse them in order (object 1 before object 2, and so on). 3935 * However, all of these objects are traversed while traversing object 0, since 3936 * the data it points to is the list of objects. Thus, we need to convert to a 3937 * canonical representation so we can compare meta-dnode bookmarks to 3938 * non-meta-dnode bookmarks. 3939 * 3940 * We do this by calculating "equivalents" for each field of the zbookmark. 3941 * zbookmarks outside of the meta-dnode use their own object and level, and 3942 * calculate the level 0 equivalent (the first L0 blkid that is contained in the 3943 * blocks this bookmark refers to) by multiplying their blkid by their span 3944 * (the number of L0 blocks contained within one block at their level). 3945 * zbookmarks inside the meta-dnode calculate their object equivalent 3946 * (which is L0equiv * dnodes per data block), use 0 for their L0equiv, and use 3947 * level + 1<<31 (any value larger than a level could ever be) for their level. 3948 * This causes them to always compare before a bookmark in their object 3949 * equivalent, compare appropriately to bookmarks in other objects, and to 3950 * compare appropriately to other bookmarks in the meta-dnode. 3951 */ 3952int 3953zbookmark_compare(uint16_t dbss1, uint8_t ibs1, uint16_t dbss2, uint8_t ibs2, 3954 const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2) 3955{ 3956 /* 3957 * These variables represent the "equivalent" values for the zbookmark, 3958 * after converting zbookmarks inside the meta dnode to their 3959 * normal-object equivalents. 3960 */ 3961 uint64_t zb1obj, zb2obj; 3962 uint64_t zb1L0, zb2L0; 3963 uint64_t zb1level, zb2level; 3964 3965 if (zb1->zb_object == zb2->zb_object && 3966 zb1->zb_level == zb2->zb_level && 3967 zb1->zb_blkid == zb2->zb_blkid) 3968 return (0); 3969 3970 /* 3971 * BP_SPANB calculates the span in blocks. 3972 */ 3973 zb1L0 = (zb1->zb_blkid) * BP_SPANB(ibs1, zb1->zb_level); 3974 zb2L0 = (zb2->zb_blkid) * BP_SPANB(ibs2, zb2->zb_level); 3975 3976 if (zb1->zb_object == DMU_META_DNODE_OBJECT) { 3977 zb1obj = zb1L0 * (dbss1 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT)); 3978 zb1L0 = 0; 3979 zb1level = zb1->zb_level + COMPARE_META_LEVEL; 3980 } else { 3981 zb1obj = zb1->zb_object; 3982 zb1level = zb1->zb_level; 3983 } 3984 3985 if (zb2->zb_object == DMU_META_DNODE_OBJECT) { 3986 zb2obj = zb2L0 * (dbss2 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT)); 3987 zb2L0 = 0; 3988 zb2level = zb2->zb_level + COMPARE_META_LEVEL; 3989 } else { 3990 zb2obj = zb2->zb_object; 3991 zb2level = zb2->zb_level; 3992 } 3993 3994 /* Now that we have a canonical representation, do the comparison. */ 3995 if (zb1obj != zb2obj) 3996 return (zb1obj < zb2obj ? -1 : 1); 3997 else if (zb1L0 != zb2L0) 3998 return (zb1L0 < zb2L0 ? -1 : 1); 3999 else if (zb1level != zb2level) 4000 return (zb1level > zb2level ? -1 : 1); 4001 /* 4002 * This can (theoretically) happen if the bookmarks have the same object 4003 * and level, but different blkids, if the block sizes are not the same. 4004 * There is presently no way to change the indirect block sizes 4005 */ 4006 return (0); 4007} 4008 4009/* 4010 * This function checks the following: given that last_block is the place that 4011 * our traversal stopped last time, does that guarantee that we've visited 4012 * every node under subtree_root? Therefore, we can't just use the raw output 4013 * of zbookmark_compare. We have to pass in a modified version of 4014 * subtree_root; by incrementing the block id, and then checking whether 4015 * last_block is before or equal to that, we can tell whether or not having 4016 * visited last_block implies that all of subtree_root's children have been 4017 * visited. 4018 */ 4019boolean_t 4020zbookmark_subtree_completed(const dnode_phys_t *dnp, 4021 const zbookmark_phys_t *subtree_root, const zbookmark_phys_t *last_block) 4022{ 4023 zbookmark_phys_t mod_zb = *subtree_root; 4024 mod_zb.zb_blkid++; 4025 ASSERT(last_block->zb_level == 0); 4026 4027 /* The objset_phys_t isn't before anything. */ 4028 if (dnp == NULL) 4029 return (B_FALSE); 4030 4031 /* 4032 * We pass in 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT) for the 4033 * data block size in sectors, because that variable is only used if 4034 * the bookmark refers to a block in the meta-dnode. Since we don't 4035 * know without examining it what object it refers to, and there's no 4036 * harm in passing in this value in other cases, we always pass it in. 4037 * 4038 * We pass in 0 for the indirect block size shift because zb2 must be 4039 * level 0. The indirect block size is only used to calculate the span 4040 * of the bookmark, but since the bookmark must be level 0, the span is 4041 * always 1, so the math works out. 4042 * 4043 * If you make changes to how the zbookmark_compare code works, be sure 4044 * to make sure that this code still works afterwards. 4045 */ 4046 return (zbookmark_compare(dnp->dn_datablkszsec, dnp->dn_indblkshift, 4047 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT), 0, &mod_zb, 4048 last_block) <= 0); 4049} 4050