zio.c revision 330238
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 53TUNABLE_INT("vfs.zfs.zio.use_uma", &zio_use_uma); 54SYSCTL_INT(_vfs_zfs_zio, OID_AUTO, use_uma, CTLFLAG_RDTUN, &zio_use_uma, 0, 55 "Use uma(9) for ZIO allocations"); 56static int zio_exclude_metadata = 0; 57TUNABLE_INT("vfs.zfs.zio.exclude_metadata", &zio_exclude_metadata); 58SYSCTL_INT(_vfs_zfs_zio, OID_AUTO, exclude_metadata, CTLFLAG_RDTUN, &zio_exclude_metadata, 0, 59 "Exclude metadata buffers from dumps as well"); 60 61zio_trim_stats_t zio_trim_stats = { 62 { "bytes", KSTAT_DATA_UINT64, 63 "Number of bytes successfully TRIMmed" }, 64 { "success", KSTAT_DATA_UINT64, 65 "Number of successful TRIM requests" }, 66 { "unsupported", KSTAT_DATA_UINT64, 67 "Number of TRIM requests that failed because TRIM is not supported" }, 68 { "failed", KSTAT_DATA_UINT64, 69 "Number of TRIM requests that failed for reasons other than not supported" }, 70}; 71 72static kstat_t *zio_trim_ksp; 73 74/* 75 * ========================================================================== 76 * I/O type descriptions 77 * ========================================================================== 78 */ 79const char *zio_type_name[ZIO_TYPES] = { 80 "zio_null", "zio_read", "zio_write", "zio_free", "zio_claim", 81 "zio_ioctl" 82}; 83 84boolean_t zio_dva_throttle_enabled = B_TRUE; 85SYSCTL_INT(_vfs_zfs_zio, OID_AUTO, dva_throttle_enabled, CTLFLAG_RDTUN, 86 &zio_dva_throttle_enabled, 0, ""); 87 88/* 89 * ========================================================================== 90 * I/O kmem caches 91 * ========================================================================== 92 */ 93kmem_cache_t *zio_cache; 94kmem_cache_t *zio_link_cache; 95kmem_cache_t *zio_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; 96kmem_cache_t *zio_data_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; 97 98#ifdef _KERNEL 99extern vmem_t *zio_alloc_arena; 100#endif 101 102#define ZIO_PIPELINE_CONTINUE 0x100 103#define ZIO_PIPELINE_STOP 0x101 104 105#define BP_SPANB(indblkshift, level) \ 106 (((uint64_t)1) << ((level) * ((indblkshift) - SPA_BLKPTRSHIFT))) 107#define COMPARE_META_LEVEL 0x80000000ul 108/* 109 * The following actions directly effect the spa's sync-to-convergence logic. 110 * The values below define the sync pass when we start performing the action. 111 * Care should be taken when changing these values as they directly impact 112 * spa_sync() performance. Tuning these values may introduce subtle performance 113 * pathologies and should only be done in the context of performance analysis. 114 * These tunables will eventually be removed and replaced with #defines once 115 * enough analysis has been done to determine optimal values. 116 * 117 * The 'zfs_sync_pass_deferred_free' pass must be greater than 1 to ensure that 118 * regular blocks are not deferred. 119 */ 120int zfs_sync_pass_deferred_free = 2; /* defer frees starting in this pass */ 121TUNABLE_INT("vfs.zfs.sync_pass_deferred_free", &zfs_sync_pass_deferred_free); 122SYSCTL_INT(_vfs_zfs, OID_AUTO, sync_pass_deferred_free, CTLFLAG_RDTUN, 123 &zfs_sync_pass_deferred_free, 0, "defer frees starting in this pass"); 124int zfs_sync_pass_dont_compress = 5; /* don't compress starting in this pass */ 125TUNABLE_INT("vfs.zfs.sync_pass_dont_compress", &zfs_sync_pass_dont_compress); 126SYSCTL_INT(_vfs_zfs, OID_AUTO, sync_pass_dont_compress, CTLFLAG_RDTUN, 127 &zfs_sync_pass_dont_compress, 0, "don't compress starting in this pass"); 128int zfs_sync_pass_rewrite = 2; /* rewrite new bps starting in this pass */ 129TUNABLE_INT("vfs.zfs.sync_pass_rewrite", &zfs_sync_pass_rewrite); 130SYSCTL_INT(_vfs_zfs, OID_AUTO, sync_pass_rewrite, CTLFLAG_RDTUN, 131 &zfs_sync_pass_rewrite, 0, "rewrite new bps starting in this pass"); 132 133/* 134 * An allocating zio is one that either currently has the DVA allocate 135 * stage set or will have it later in its lifetime. 136 */ 137#define IO_IS_ALLOCATING(zio) ((zio)->io_orig_pipeline & ZIO_STAGE_DVA_ALLOCATE) 138 139boolean_t zio_requeue_io_start_cut_in_line = B_TRUE; 140 141#ifdef illumos 142#ifdef ZFS_DEBUG 143int zio_buf_debug_limit = 16384; 144#else 145int zio_buf_debug_limit = 0; 146#endif 147#endif 148 149static void zio_taskq_dispatch(zio_t *, zio_taskq_type_t, boolean_t); 150 151void 152zio_init(void) 153{ 154 size_t c; 155 zio_cache = kmem_cache_create("zio_cache", 156 sizeof (zio_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 157 zio_link_cache = kmem_cache_create("zio_link_cache", 158 sizeof (zio_link_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 159 if (!zio_use_uma) 160 goto out; 161 162 /* 163 * For small buffers, we want a cache for each multiple of 164 * SPA_MINBLOCKSIZE. For larger buffers, we want a cache 165 * for each quarter-power of 2. 166 */ 167 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { 168 size_t size = (c + 1) << SPA_MINBLOCKSHIFT; 169 size_t p2 = size; 170 size_t align = 0; 171 int cflags = zio_exclude_metadata ? KMC_NODEBUG : 0; 172 173 while (!ISP2(p2)) 174 p2 &= p2 - 1; 175 176#ifdef illumos 177#ifndef _KERNEL 178 /* 179 * If we are using watchpoints, put each buffer on its own page, 180 * to eliminate the performance overhead of trapping to the 181 * kernel when modifying a non-watched buffer that shares the 182 * page with a watched buffer. 183 */ 184 if (arc_watch && !IS_P2ALIGNED(size, PAGESIZE)) 185 continue; 186#endif 187#endif /* illumos */ 188 if (size <= 4 * SPA_MINBLOCKSIZE) { 189 align = SPA_MINBLOCKSIZE; 190 } else if (IS_P2ALIGNED(size, p2 >> 2)) { 191 align = MIN(p2 >> 2, PAGESIZE); 192 } 193 194 if (align != 0) { 195 char name[36]; 196 (void) sprintf(name, "zio_buf_%lu", (ulong_t)size); 197 zio_buf_cache[c] = kmem_cache_create(name, size, 198 align, NULL, NULL, NULL, NULL, NULL, cflags); 199 200 /* 201 * Since zio_data bufs do not appear in crash dumps, we 202 * pass KMC_NOTOUCH so that no allocator metadata is 203 * stored with the buffers. 204 */ 205 (void) sprintf(name, "zio_data_buf_%lu", (ulong_t)size); 206 zio_data_buf_cache[c] = kmem_cache_create(name, size, 207 align, NULL, NULL, NULL, NULL, NULL, 208 cflags | KMC_NOTOUCH | KMC_NODEBUG); 209 } 210 } 211 212 while (--c != 0) { 213 ASSERT(zio_buf_cache[c] != NULL); 214 if (zio_buf_cache[c - 1] == NULL) 215 zio_buf_cache[c - 1] = zio_buf_cache[c]; 216 217 ASSERT(zio_data_buf_cache[c] != NULL); 218 if (zio_data_buf_cache[c - 1] == NULL) 219 zio_data_buf_cache[c - 1] = zio_data_buf_cache[c]; 220 } 221out: 222 223 zio_inject_init(); 224 225 zio_trim_ksp = kstat_create("zfs", 0, "zio_trim", "misc", 226 KSTAT_TYPE_NAMED, 227 sizeof(zio_trim_stats) / sizeof(kstat_named_t), 228 KSTAT_FLAG_VIRTUAL); 229 230 if (zio_trim_ksp != NULL) { 231 zio_trim_ksp->ks_data = &zio_trim_stats; 232 kstat_install(zio_trim_ksp); 233 } 234} 235 236void 237zio_fini(void) 238{ 239 size_t c; 240 kmem_cache_t *last_cache = NULL; 241 kmem_cache_t *last_data_cache = NULL; 242 243 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { 244 if (zio_buf_cache[c] != last_cache) { 245 last_cache = zio_buf_cache[c]; 246 kmem_cache_destroy(zio_buf_cache[c]); 247 } 248 zio_buf_cache[c] = NULL; 249 250 if (zio_data_buf_cache[c] != last_data_cache) { 251 last_data_cache = zio_data_buf_cache[c]; 252 kmem_cache_destroy(zio_data_buf_cache[c]); 253 } 254 zio_data_buf_cache[c] = NULL; 255 } 256 257 kmem_cache_destroy(zio_link_cache); 258 kmem_cache_destroy(zio_cache); 259 260 zio_inject_fini(); 261 262 if (zio_trim_ksp != NULL) { 263 kstat_delete(zio_trim_ksp); 264 zio_trim_ksp = NULL; 265 } 266} 267 268/* 269 * ========================================================================== 270 * Allocate and free I/O buffers 271 * ========================================================================== 272 */ 273 274/* 275 * Use zio_buf_alloc to allocate ZFS metadata. This data will appear in a 276 * crashdump if the kernel panics, so use it judiciously. Obviously, it's 277 * useful to inspect ZFS metadata, but if possible, we should avoid keeping 278 * excess / transient data in-core during a crashdump. 279 */ 280static void * 281zio_buf_alloc_impl(size_t size, boolean_t canwait) 282{ 283 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 284 int flags = zio_exclude_metadata ? KM_NODEBUG : 0; 285 286 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 287 288 if (zio_use_uma) { 289 return (kmem_cache_alloc(zio_buf_cache[c], 290 canwait ? KM_PUSHPAGE : KM_NOSLEEP)); 291 } else { 292 return (kmem_alloc(size, 293 (canwait ? KM_SLEEP : KM_NOSLEEP) | flags)); 294 } 295} 296 297void * 298zio_buf_alloc(size_t size) 299{ 300 return (zio_buf_alloc_impl(size, B_TRUE)); 301} 302 303void * 304zio_buf_alloc_nowait(size_t size) 305{ 306 return (zio_buf_alloc_impl(size, B_FALSE)); 307} 308 309/* 310 * Use zio_data_buf_alloc to allocate data. The data will not appear in a 311 * crashdump if the kernel panics. This exists so that we will limit the amount 312 * of ZFS data that shows up in a kernel crashdump. (Thus reducing the amount 313 * of kernel heap dumped to disk when the kernel panics) 314 */ 315void * 316zio_data_buf_alloc(size_t size) 317{ 318 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 319 320 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 321 322 if (zio_use_uma) 323 return (kmem_cache_alloc(zio_data_buf_cache[c], KM_PUSHPAGE)); 324 else 325 return (kmem_alloc(size, KM_SLEEP | KM_NODEBUG)); 326} 327 328void 329zio_buf_free(void *buf, size_t size) 330{ 331 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 332 333 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 334 335 if (zio_use_uma) 336 kmem_cache_free(zio_buf_cache[c], buf); 337 else 338 kmem_free(buf, size); 339} 340 341void 342zio_data_buf_free(void *buf, size_t size) 343{ 344 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 345 346 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 347 348 if (zio_use_uma) 349 kmem_cache_free(zio_data_buf_cache[c], buf); 350 else 351 kmem_free(buf, size); 352} 353 354/* 355 * ========================================================================== 356 * Push and pop I/O transform buffers 357 * ========================================================================== 358 */ 359void 360zio_push_transform(zio_t *zio, void *data, uint64_t size, uint64_t bufsize, 361 zio_transform_func_t *transform) 362{ 363 zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP); 364 365 zt->zt_orig_data = zio->io_data; 366 zt->zt_orig_size = zio->io_size; 367 zt->zt_bufsize = bufsize; 368 zt->zt_transform = transform; 369 370 zt->zt_next = zio->io_transform_stack; 371 zio->io_transform_stack = zt; 372 373 zio->io_data = data; 374 zio->io_size = size; 375} 376 377void 378zio_pop_transforms(zio_t *zio) 379{ 380 zio_transform_t *zt; 381 382 while ((zt = zio->io_transform_stack) != NULL) { 383 if (zt->zt_transform != NULL) 384 zt->zt_transform(zio, 385 zt->zt_orig_data, zt->zt_orig_size); 386 387 if (zt->zt_bufsize != 0) 388 zio_buf_free(zio->io_data, zt->zt_bufsize); 389 390 zio->io_data = zt->zt_orig_data; 391 zio->io_size = zt->zt_orig_size; 392 zio->io_transform_stack = zt->zt_next; 393 394 kmem_free(zt, sizeof (zio_transform_t)); 395 } 396} 397 398/* 399 * ========================================================================== 400 * I/O transform callbacks for subblocks and decompression 401 * ========================================================================== 402 */ 403static void 404zio_subblock(zio_t *zio, void *data, uint64_t size) 405{ 406 ASSERT(zio->io_size > size); 407 408 if (zio->io_type == ZIO_TYPE_READ) 409 bcopy(zio->io_data, data, size); 410} 411 412static void 413zio_decompress(zio_t *zio, void *data, uint64_t size) 414{ 415 if (zio->io_error == 0 && 416 zio_decompress_data(BP_GET_COMPRESS(zio->io_bp), 417 zio->io_data, data, zio->io_size, size) != 0) 418 zio->io_error = SET_ERROR(EIO); 419} 420 421/* 422 * ========================================================================== 423 * I/O parent/child relationships and pipeline interlocks 424 * ========================================================================== 425 */ 426zio_t * 427zio_walk_parents(zio_t *cio, zio_link_t **zl) 428{ 429 list_t *pl = &cio->io_parent_list; 430 431 *zl = (*zl == NULL) ? list_head(pl) : list_next(pl, *zl); 432 if (*zl == NULL) 433 return (NULL); 434 435 ASSERT((*zl)->zl_child == cio); 436 return ((*zl)->zl_parent); 437} 438 439zio_t * 440zio_walk_children(zio_t *pio, zio_link_t **zl) 441{ 442 list_t *cl = &pio->io_child_list; 443 444 *zl = (*zl == NULL) ? list_head(cl) : list_next(cl, *zl); 445 if (*zl == NULL) 446 return (NULL); 447 448 ASSERT((*zl)->zl_parent == pio); 449 return ((*zl)->zl_child); 450} 451 452zio_t * 453zio_unique_parent(zio_t *cio) 454{ 455 zio_link_t *zl = NULL; 456 zio_t *pio = zio_walk_parents(cio, &zl); 457 458 VERIFY3P(zio_walk_parents(cio, &zl), ==, NULL); 459 return (pio); 460} 461 462void 463zio_add_child(zio_t *pio, zio_t *cio) 464{ 465 zio_link_t *zl = kmem_cache_alloc(zio_link_cache, KM_SLEEP); 466 467 /* 468 * Logical I/Os can have logical, gang, or vdev children. 469 * Gang I/Os can have gang or vdev children. 470 * Vdev I/Os can only have vdev children. 471 * The following ASSERT captures all of these constraints. 472 */ 473 ASSERT(cio->io_child_type <= pio->io_child_type); 474 475 zl->zl_parent = pio; 476 zl->zl_child = cio; 477 478 mutex_enter(&cio->io_lock); 479 mutex_enter(&pio->io_lock); 480 481 ASSERT(pio->io_state[ZIO_WAIT_DONE] == 0); 482 483 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 484 pio->io_children[cio->io_child_type][w] += !cio->io_state[w]; 485 486 list_insert_head(&pio->io_child_list, zl); 487 list_insert_head(&cio->io_parent_list, zl); 488 489 pio->io_child_count++; 490 cio->io_parent_count++; 491 492 mutex_exit(&pio->io_lock); 493 mutex_exit(&cio->io_lock); 494} 495 496static void 497zio_remove_child(zio_t *pio, zio_t *cio, zio_link_t *zl) 498{ 499 ASSERT(zl->zl_parent == pio); 500 ASSERT(zl->zl_child == cio); 501 502 mutex_enter(&cio->io_lock); 503 mutex_enter(&pio->io_lock); 504 505 list_remove(&pio->io_child_list, zl); 506 list_remove(&cio->io_parent_list, zl); 507 508 pio->io_child_count--; 509 cio->io_parent_count--; 510 511 mutex_exit(&pio->io_lock); 512 mutex_exit(&cio->io_lock); 513 514 kmem_cache_free(zio_link_cache, zl); 515} 516 517static boolean_t 518zio_wait_for_children(zio_t *zio, uint8_t childbits, enum zio_wait_type wait) 519{ 520 boolean_t waiting = B_FALSE; 521 522 mutex_enter(&zio->io_lock); 523 ASSERT(zio->io_stall == NULL); 524 for (int c = 0; c < ZIO_CHILD_TYPES; c++) { 525 if (!(ZIO_CHILD_BIT_IS_SET(childbits, c))) 526 continue; 527 528 uint64_t *countp = &zio->io_children[c][wait]; 529 if (*countp != 0) { 530 zio->io_stage >>= 1; 531 ASSERT3U(zio->io_stage, !=, ZIO_STAGE_OPEN); 532 zio->io_stall = countp; 533 waiting = B_TRUE; 534 break; 535 } 536 } 537 mutex_exit(&zio->io_lock); 538 return (waiting); 539} 540 541static void 542zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait) 543{ 544 uint64_t *countp = &pio->io_children[zio->io_child_type][wait]; 545 int *errorp = &pio->io_child_error[zio->io_child_type]; 546 547 mutex_enter(&pio->io_lock); 548 if (zio->io_error && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE)) 549 *errorp = zio_worst_error(*errorp, zio->io_error); 550 pio->io_reexecute |= zio->io_reexecute; 551 ASSERT3U(*countp, >, 0); 552 553 (*countp)--; 554 555 if (*countp == 0 && pio->io_stall == countp) { 556 zio_taskq_type_t type = 557 pio->io_stage < ZIO_STAGE_VDEV_IO_START ? ZIO_TASKQ_ISSUE : 558 ZIO_TASKQ_INTERRUPT; 559 pio->io_stall = NULL; 560 mutex_exit(&pio->io_lock); 561 /* 562 * Dispatch the parent zio in its own taskq so that 563 * the child can continue to make progress. This also 564 * prevents overflowing the stack when we have deeply nested 565 * parent-child relationships. 566 */ 567 zio_taskq_dispatch(pio, type, B_FALSE); 568 } else { 569 mutex_exit(&pio->io_lock); 570 } 571} 572 573static void 574zio_inherit_child_errors(zio_t *zio, enum zio_child c) 575{ 576 if (zio->io_child_error[c] != 0 && zio->io_error == 0) 577 zio->io_error = zio->io_child_error[c]; 578} 579 580int 581zio_timestamp_compare(const void *x1, const void *x2) 582{ 583 const zio_t *z1 = x1; 584 const zio_t *z2 = x2; 585 586 if (z1->io_queued_timestamp < z2->io_queued_timestamp) 587 return (-1); 588 if (z1->io_queued_timestamp > z2->io_queued_timestamp) 589 return (1); 590 591 if (z1->io_bookmark.zb_objset < z2->io_bookmark.zb_objset) 592 return (-1); 593 if (z1->io_bookmark.zb_objset > z2->io_bookmark.zb_objset) 594 return (1); 595 596 if (z1->io_bookmark.zb_object < z2->io_bookmark.zb_object) 597 return (-1); 598 if (z1->io_bookmark.zb_object > z2->io_bookmark.zb_object) 599 return (1); 600 601 if (z1->io_bookmark.zb_level < z2->io_bookmark.zb_level) 602 return (-1); 603 if (z1->io_bookmark.zb_level > z2->io_bookmark.zb_level) 604 return (1); 605 606 if (z1->io_bookmark.zb_blkid < z2->io_bookmark.zb_blkid) 607 return (-1); 608 if (z1->io_bookmark.zb_blkid > z2->io_bookmark.zb_blkid) 609 return (1); 610 611 if (z1 < z2) 612 return (-1); 613 if (z1 > z2) 614 return (1); 615 616 return (0); 617} 618 619/* 620 * ========================================================================== 621 * Create the various types of I/O (read, write, free, etc) 622 * ========================================================================== 623 */ 624static zio_t * 625zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 626 void *data, uint64_t size, zio_done_func_t *done, void *private, 627 zio_type_t type, zio_priority_t priority, enum zio_flag flags, 628 vdev_t *vd, uint64_t offset, const zbookmark_phys_t *zb, 629 enum zio_stage stage, enum zio_stage pipeline) 630{ 631 zio_t *zio; 632 633 ASSERT3U(type == ZIO_TYPE_FREE || size, <=, SPA_MAXBLOCKSIZE); 634 ASSERT(P2PHASE(size, SPA_MINBLOCKSIZE) == 0); 635 ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0); 636 637 ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER)); 638 ASSERT(!bp || !(flags & ZIO_FLAG_CONFIG_WRITER)); 639 ASSERT(vd || stage == ZIO_STAGE_OPEN); 640 641 zio = kmem_cache_alloc(zio_cache, KM_SLEEP); 642 bzero(zio, sizeof (zio_t)); 643 644 mutex_init(&zio->io_lock, NULL, MUTEX_DEFAULT, NULL); 645 cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL); 646 647 list_create(&zio->io_parent_list, sizeof (zio_link_t), 648 offsetof(zio_link_t, zl_parent_node)); 649 list_create(&zio->io_child_list, sizeof (zio_link_t), 650 offsetof(zio_link_t, zl_child_node)); 651 652 if (vd != NULL) 653 zio->io_child_type = ZIO_CHILD_VDEV; 654 else if (flags & ZIO_FLAG_GANG_CHILD) 655 zio->io_child_type = ZIO_CHILD_GANG; 656 else if (flags & ZIO_FLAG_DDT_CHILD) 657 zio->io_child_type = ZIO_CHILD_DDT; 658 else 659 zio->io_child_type = ZIO_CHILD_LOGICAL; 660 661 if (bp != NULL) { 662 zio->io_bp = (blkptr_t *)bp; 663 zio->io_bp_copy = *bp; 664 zio->io_bp_orig = *bp; 665 if (type != ZIO_TYPE_WRITE || 666 zio->io_child_type == ZIO_CHILD_DDT) 667 zio->io_bp = &zio->io_bp_copy; /* so caller can free */ 668 if (zio->io_child_type == ZIO_CHILD_LOGICAL) 669 zio->io_logical = zio; 670 if (zio->io_child_type > ZIO_CHILD_GANG && BP_IS_GANG(bp)) 671 pipeline |= ZIO_GANG_STAGES; 672 } 673 674 zio->io_spa = spa; 675 zio->io_txg = txg; 676 zio->io_done = done; 677 zio->io_private = private; 678 zio->io_type = type; 679 zio->io_priority = priority; 680 zio->io_vd = vd; 681 zio->io_offset = offset; 682 zio->io_orig_data = zio->io_data = data; 683 zio->io_orig_size = zio->io_size = size; 684 zio->io_orig_flags = zio->io_flags = flags; 685 zio->io_orig_stage = zio->io_stage = stage; 686 zio->io_orig_pipeline = zio->io_pipeline = pipeline; 687 zio->io_pipeline_trace = ZIO_STAGE_OPEN; 688 689 zio->io_state[ZIO_WAIT_READY] = (stage >= ZIO_STAGE_READY); 690 zio->io_state[ZIO_WAIT_DONE] = (stage >= ZIO_STAGE_DONE); 691 692 if (zb != NULL) 693 zio->io_bookmark = *zb; 694 695 if (pio != NULL) { 696 if (zio->io_logical == NULL) 697 zio->io_logical = pio->io_logical; 698 if (zio->io_child_type == ZIO_CHILD_GANG) 699 zio->io_gang_leader = pio->io_gang_leader; 700 zio_add_child(pio, zio); 701 } 702 703 return (zio); 704} 705 706static void 707zio_destroy(zio_t *zio) 708{ 709 list_destroy(&zio->io_parent_list); 710 list_destroy(&zio->io_child_list); 711 mutex_destroy(&zio->io_lock); 712 cv_destroy(&zio->io_cv); 713 kmem_cache_free(zio_cache, zio); 714} 715 716zio_t * 717zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, zio_done_func_t *done, 718 void *private, enum zio_flag flags) 719{ 720 zio_t *zio; 721 722 zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private, 723 ZIO_TYPE_NULL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL, 724 ZIO_STAGE_OPEN, ZIO_INTERLOCK_PIPELINE); 725 726 return (zio); 727} 728 729zio_t * 730zio_root(spa_t *spa, zio_done_func_t *done, void *private, enum zio_flag flags) 731{ 732 return (zio_null(NULL, spa, NULL, done, private, flags)); 733} 734 735void 736zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp) 737{ 738 if (!DMU_OT_IS_VALID(BP_GET_TYPE(bp))) { 739 zfs_panic_recover("blkptr at %p has invalid TYPE %llu", 740 bp, (longlong_t)BP_GET_TYPE(bp)); 741 } 742 if (BP_GET_CHECKSUM(bp) >= ZIO_CHECKSUM_FUNCTIONS || 743 BP_GET_CHECKSUM(bp) <= ZIO_CHECKSUM_ON) { 744 zfs_panic_recover("blkptr at %p has invalid CHECKSUM %llu", 745 bp, (longlong_t)BP_GET_CHECKSUM(bp)); 746 } 747 if (BP_GET_COMPRESS(bp) >= ZIO_COMPRESS_FUNCTIONS || 748 BP_GET_COMPRESS(bp) <= ZIO_COMPRESS_ON) { 749 zfs_panic_recover("blkptr at %p has invalid COMPRESS %llu", 750 bp, (longlong_t)BP_GET_COMPRESS(bp)); 751 } 752 if (BP_GET_LSIZE(bp) > SPA_MAXBLOCKSIZE) { 753 zfs_panic_recover("blkptr at %p has invalid LSIZE %llu", 754 bp, (longlong_t)BP_GET_LSIZE(bp)); 755 } 756 if (BP_GET_PSIZE(bp) > SPA_MAXBLOCKSIZE) { 757 zfs_panic_recover("blkptr at %p has invalid PSIZE %llu", 758 bp, (longlong_t)BP_GET_PSIZE(bp)); 759 } 760 761 if (BP_IS_EMBEDDED(bp)) { 762 if (BPE_GET_ETYPE(bp) > NUM_BP_EMBEDDED_TYPES) { 763 zfs_panic_recover("blkptr at %p has invalid ETYPE %llu", 764 bp, (longlong_t)BPE_GET_ETYPE(bp)); 765 } 766 } 767 768 /* 769 * Pool-specific checks. 770 * 771 * Note: it would be nice to verify that the blk_birth and 772 * BP_PHYSICAL_BIRTH() are not too large. However, spa_freeze() 773 * allows the birth time of log blocks (and dmu_sync()-ed blocks 774 * that are in the log) to be arbitrarily large. 775 */ 776 for (int i = 0; i < BP_GET_NDVAS(bp); i++) { 777 uint64_t vdevid = DVA_GET_VDEV(&bp->blk_dva[i]); 778 if (vdevid >= spa->spa_root_vdev->vdev_children) { 779 zfs_panic_recover("blkptr at %p DVA %u has invalid " 780 "VDEV %llu", 781 bp, i, (longlong_t)vdevid); 782 continue; 783 } 784 vdev_t *vd = spa->spa_root_vdev->vdev_child[vdevid]; 785 if (vd == NULL) { 786 zfs_panic_recover("blkptr at %p DVA %u has invalid " 787 "VDEV %llu", 788 bp, i, (longlong_t)vdevid); 789 continue; 790 } 791 if (vd->vdev_ops == &vdev_hole_ops) { 792 zfs_panic_recover("blkptr at %p DVA %u has hole " 793 "VDEV %llu", 794 bp, i, (longlong_t)vdevid); 795 continue; 796 } 797 if (vd->vdev_ops == &vdev_missing_ops) { 798 /* 799 * "missing" vdevs are valid during import, but we 800 * don't have their detailed info (e.g. asize), so 801 * we can't perform any more checks on them. 802 */ 803 continue; 804 } 805 uint64_t offset = DVA_GET_OFFSET(&bp->blk_dva[i]); 806 uint64_t asize = DVA_GET_ASIZE(&bp->blk_dva[i]); 807 if (BP_IS_GANG(bp)) 808 asize = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE); 809 if (offset + asize > vd->vdev_asize) { 810 zfs_panic_recover("blkptr at %p DVA %u has invalid " 811 "OFFSET %llu", 812 bp, i, (longlong_t)offset); 813 } 814 } 815} 816 817zio_t * 818zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, 819 void *data, uint64_t size, zio_done_func_t *done, void *private, 820 zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb) 821{ 822 zio_t *zio; 823 824 zfs_blkptr_verify(spa, bp); 825 826 zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp, 827 data, size, done, private, 828 ZIO_TYPE_READ, priority, flags, NULL, 0, zb, 829 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 830 ZIO_DDT_CHILD_READ_PIPELINE : ZIO_READ_PIPELINE); 831 832 return (zio); 833} 834 835zio_t * 836zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, 837 void *data, uint64_t size, const zio_prop_t *zp, 838 zio_done_func_t *ready, zio_done_func_t *children_ready, 839 zio_done_func_t *physdone, zio_done_func_t *done, 840 void *private, zio_priority_t priority, enum zio_flag flags, 841 const zbookmark_phys_t *zb) 842{ 843 zio_t *zio; 844 845 ASSERT(zp->zp_checksum >= ZIO_CHECKSUM_OFF && 846 zp->zp_checksum < ZIO_CHECKSUM_FUNCTIONS && 847 zp->zp_compress >= ZIO_COMPRESS_OFF && 848 zp->zp_compress < ZIO_COMPRESS_FUNCTIONS && 849 DMU_OT_IS_VALID(zp->zp_type) && 850 zp->zp_level < 32 && 851 zp->zp_copies > 0 && 852 zp->zp_copies <= spa_max_replication(spa)); 853 854 zio = zio_create(pio, spa, txg, bp, data, size, done, private, 855 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 856 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 857 ZIO_DDT_CHILD_WRITE_PIPELINE : ZIO_WRITE_PIPELINE); 858 859 zio->io_ready = ready; 860 zio->io_children_ready = children_ready; 861 zio->io_physdone = physdone; 862 zio->io_prop = *zp; 863 864 /* 865 * Data can be NULL if we are going to call zio_write_override() to 866 * provide the already-allocated BP. But we may need the data to 867 * verify a dedup hit (if requested). In this case, don't try to 868 * dedup (just take the already-allocated BP verbatim). 869 */ 870 if (data == NULL && zio->io_prop.zp_dedup_verify) { 871 zio->io_prop.zp_dedup = zio->io_prop.zp_dedup_verify = B_FALSE; 872 } 873 874 return (zio); 875} 876 877zio_t * 878zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, void *data, 879 uint64_t size, zio_done_func_t *done, void *private, 880 zio_priority_t priority, enum zio_flag flags, zbookmark_phys_t *zb) 881{ 882 zio_t *zio; 883 884 zio = zio_create(pio, spa, txg, bp, data, size, done, private, 885 ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_IO_REWRITE, NULL, 0, zb, 886 ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE); 887 888 return (zio); 889} 890 891void 892zio_write_override(zio_t *zio, blkptr_t *bp, int copies, boolean_t nopwrite) 893{ 894 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 895 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 896 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 897 ASSERT(zio->io_txg == spa_syncing_txg(zio->io_spa)); 898 899 /* 900 * We must reset the io_prop to match the values that existed 901 * when the bp was first written by dmu_sync() keeping in mind 902 * that nopwrite and dedup are mutually exclusive. 903 */ 904 zio->io_prop.zp_dedup = nopwrite ? B_FALSE : zio->io_prop.zp_dedup; 905 zio->io_prop.zp_nopwrite = nopwrite; 906 zio->io_prop.zp_copies = copies; 907 zio->io_bp_override = bp; 908} 909 910void 911zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp) 912{ 913 914 /* 915 * The check for EMBEDDED is a performance optimization. We 916 * process the free here (by ignoring it) rather than 917 * putting it on the list and then processing it in zio_free_sync(). 918 */ 919 if (BP_IS_EMBEDDED(bp)) 920 return; 921 metaslab_check_free(spa, bp); 922 923 /* 924 * Frees that are for the currently-syncing txg, are not going to be 925 * deferred, and which will not need to do a read (i.e. not GANG or 926 * DEDUP), can be processed immediately. Otherwise, put them on the 927 * in-memory list for later processing. 928 */ 929 if (zfs_trim_enabled || BP_IS_GANG(bp) || BP_GET_DEDUP(bp) || 930 txg != spa->spa_syncing_txg || 931 spa_sync_pass(spa) >= zfs_sync_pass_deferred_free) { 932 bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp); 933 } else { 934 VERIFY0(zio_wait(zio_free_sync(NULL, spa, txg, bp, 935 BP_GET_PSIZE(bp), 0))); 936 } 937} 938 939zio_t * 940zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 941 uint64_t size, enum zio_flag flags) 942{ 943 zio_t *zio; 944 enum zio_stage stage = ZIO_FREE_PIPELINE; 945 946 ASSERT(!BP_IS_HOLE(bp)); 947 ASSERT(spa_syncing_txg(spa) == txg); 948 ASSERT(spa_sync_pass(spa) < zfs_sync_pass_deferred_free); 949 950 if (BP_IS_EMBEDDED(bp)) 951 return (zio_null(pio, spa, NULL, NULL, NULL, 0)); 952 953 metaslab_check_free(spa, bp); 954 arc_freed(spa, bp); 955 956 if (zfs_trim_enabled) 957 stage |= ZIO_STAGE_ISSUE_ASYNC | ZIO_STAGE_VDEV_IO_START | 958 ZIO_STAGE_VDEV_IO_ASSESS; 959 /* 960 * GANG and DEDUP blocks can induce a read (for the gang block header, 961 * or the DDT), so issue them asynchronously so that this thread is 962 * not tied up. 963 */ 964 else if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp)) 965 stage |= ZIO_STAGE_ISSUE_ASYNC; 966 967 flags |= ZIO_FLAG_DONT_QUEUE; 968 969 zio = zio_create(pio, spa, txg, bp, NULL, size, 970 NULL, NULL, ZIO_TYPE_FREE, ZIO_PRIORITY_NOW, flags, 971 NULL, 0, NULL, ZIO_STAGE_OPEN, stage); 972 973 return (zio); 974} 975 976zio_t * 977zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 978 zio_done_func_t *done, void *private, enum zio_flag flags) 979{ 980 zio_t *zio; 981 982 dprintf_bp(bp, "claiming in txg %llu", txg); 983 984 if (BP_IS_EMBEDDED(bp)) 985 return (zio_null(pio, spa, NULL, NULL, NULL, 0)); 986 987 /* 988 * A claim is an allocation of a specific block. Claims are needed 989 * to support immediate writes in the intent log. The issue is that 990 * immediate writes contain committed data, but in a txg that was 991 * *not* committed. Upon opening the pool after an unclean shutdown, 992 * the intent log claims all blocks that contain immediate write data 993 * so that the SPA knows they're in use. 994 * 995 * All claims *must* be resolved in the first txg -- before the SPA 996 * starts allocating blocks -- so that nothing is allocated twice. 997 * If txg == 0 we just verify that the block is claimable. 998 */ 999 ASSERT3U(spa->spa_uberblock.ub_rootbp.blk_birth, <, spa_first_txg(spa)); 1000 ASSERT(txg == spa_first_txg(spa) || txg == 0); 1001 ASSERT(!BP_GET_DEDUP(bp) || !spa_writeable(spa)); /* zdb(1M) */ 1002 1003 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 1004 done, private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW, flags, 1005 NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE); 1006 ASSERT0(zio->io_queued_timestamp); 1007 1008 return (zio); 1009} 1010 1011zio_t * 1012zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd, uint64_t offset, 1013 uint64_t size, zio_done_func_t *done, void *private, 1014 zio_priority_t priority, enum zio_flag flags) 1015{ 1016 zio_t *zio; 1017 int c; 1018 1019 if (vd->vdev_children == 0) { 1020 zio = zio_create(pio, spa, 0, NULL, NULL, size, done, private, 1021 ZIO_TYPE_IOCTL, priority, flags, vd, offset, NULL, 1022 ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE); 1023 1024 zio->io_cmd = cmd; 1025 } else { 1026 zio = zio_null(pio, spa, NULL, NULL, NULL, flags); 1027 1028 for (c = 0; c < vd->vdev_children; c++) 1029 zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd, 1030 offset, size, done, private, priority, flags)); 1031 } 1032 1033 return (zio); 1034} 1035 1036zio_t * 1037zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 1038 void *data, int checksum, zio_done_func_t *done, void *private, 1039 zio_priority_t priority, enum zio_flag flags, boolean_t labels) 1040{ 1041 zio_t *zio; 1042 1043 ASSERT(vd->vdev_children == 0); 1044 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 1045 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 1046 ASSERT3U(offset + size, <=, vd->vdev_psize); 1047 1048 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private, 1049 ZIO_TYPE_READ, priority, flags | ZIO_FLAG_PHYSICAL, vd, offset, 1050 NULL, ZIO_STAGE_OPEN, ZIO_READ_PHYS_PIPELINE); 1051 1052 zio->io_prop.zp_checksum = checksum; 1053 1054 return (zio); 1055} 1056 1057zio_t * 1058zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 1059 void *data, int checksum, zio_done_func_t *done, void *private, 1060 zio_priority_t priority, enum zio_flag flags, boolean_t labels) 1061{ 1062 zio_t *zio; 1063 1064 ASSERT(vd->vdev_children == 0); 1065 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 1066 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 1067 ASSERT3U(offset + size, <=, vd->vdev_psize); 1068 1069 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private, 1070 ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_PHYSICAL, vd, offset, 1071 NULL, ZIO_STAGE_OPEN, ZIO_WRITE_PHYS_PIPELINE); 1072 1073 zio->io_prop.zp_checksum = checksum; 1074 1075 if (zio_checksum_table[checksum].ci_flags & ZCHECKSUM_FLAG_EMBEDDED) { 1076 /* 1077 * zec checksums are necessarily destructive -- they modify 1078 * the end of the write buffer to hold the verifier/checksum. 1079 * Therefore, we must make a local copy in case the data is 1080 * being written to multiple places in parallel. 1081 */ 1082 void *wbuf = zio_buf_alloc(size); 1083 bcopy(data, wbuf, size); 1084 zio_push_transform(zio, wbuf, size, size, NULL); 1085 } 1086 1087 return (zio); 1088} 1089 1090/* 1091 * Create a child I/O to do some work for us. 1092 */ 1093zio_t * 1094zio_vdev_child_io(zio_t *pio, blkptr_t *bp, vdev_t *vd, uint64_t offset, 1095 void *data, uint64_t size, int type, zio_priority_t priority, 1096 enum zio_flag flags, zio_done_func_t *done, void *private) 1097{ 1098 enum zio_stage pipeline = ZIO_VDEV_CHILD_PIPELINE; 1099 zio_t *zio; 1100 1101 ASSERT(vd->vdev_parent == 1102 (pio->io_vd ? pio->io_vd : pio->io_spa->spa_root_vdev)); 1103 1104 if (type == ZIO_TYPE_READ && bp != NULL) { 1105 /* 1106 * If we have the bp, then the child should perform the 1107 * checksum and the parent need not. This pushes error 1108 * detection as close to the leaves as possible and 1109 * eliminates redundant checksums in the interior nodes. 1110 */ 1111 pipeline |= ZIO_STAGE_CHECKSUM_VERIFY; 1112 pio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 1113 } 1114 1115 /* Not all IO types require vdev io done stage e.g. free */ 1116 if (!(pio->io_pipeline & ZIO_STAGE_VDEV_IO_DONE)) 1117 pipeline &= ~ZIO_STAGE_VDEV_IO_DONE; 1118 1119 if (vd->vdev_children == 0) 1120 offset += VDEV_LABEL_START_SIZE; 1121 1122 flags |= ZIO_VDEV_CHILD_FLAGS(pio) | ZIO_FLAG_DONT_PROPAGATE; 1123 1124 /* 1125 * If we've decided to do a repair, the write is not speculative -- 1126 * even if the original read was. 1127 */ 1128 if (flags & ZIO_FLAG_IO_REPAIR) 1129 flags &= ~ZIO_FLAG_SPECULATIVE; 1130 1131 /* 1132 * If we're creating a child I/O that is not associated with a 1133 * top-level vdev, then the child zio is not an allocating I/O. 1134 * If this is a retried I/O then we ignore it since we will 1135 * have already processed the original allocating I/O. 1136 */ 1137 if (flags & ZIO_FLAG_IO_ALLOCATING && 1138 (vd != vd->vdev_top || (flags & ZIO_FLAG_IO_RETRY))) { 1139 metaslab_class_t *mc = spa_normal_class(pio->io_spa); 1140 1141 ASSERT(mc->mc_alloc_throttle_enabled); 1142 ASSERT(type == ZIO_TYPE_WRITE); 1143 ASSERT(priority == ZIO_PRIORITY_ASYNC_WRITE); 1144 ASSERT(!(flags & ZIO_FLAG_IO_REPAIR)); 1145 ASSERT(!(pio->io_flags & ZIO_FLAG_IO_REWRITE) || 1146 pio->io_child_type == ZIO_CHILD_GANG); 1147 1148 flags &= ~ZIO_FLAG_IO_ALLOCATING; 1149 } 1150 1151 zio = zio_create(pio, pio->io_spa, pio->io_txg, bp, data, size, 1152 done, private, type, priority, flags, vd, offset, &pio->io_bookmark, 1153 ZIO_STAGE_VDEV_IO_START >> 1, pipeline); 1154 ASSERT3U(zio->io_child_type, ==, ZIO_CHILD_VDEV); 1155 1156 zio->io_physdone = pio->io_physdone; 1157 if (vd->vdev_ops->vdev_op_leaf && zio->io_logical != NULL) 1158 zio->io_logical->io_phys_children++; 1159 1160 return (zio); 1161} 1162 1163zio_t * 1164zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, void *data, uint64_t size, 1165 int type, zio_priority_t priority, enum zio_flag flags, 1166 zio_done_func_t *done, void *private) 1167{ 1168 zio_t *zio; 1169 1170 ASSERT(vd->vdev_ops->vdev_op_leaf); 1171 1172 zio = zio_create(NULL, vd->vdev_spa, 0, NULL, 1173 data, size, done, private, type, priority, 1174 flags | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY | ZIO_FLAG_DELEGATED, 1175 vd, offset, NULL, 1176 ZIO_STAGE_VDEV_IO_START >> 1, ZIO_VDEV_CHILD_PIPELINE); 1177 1178 return (zio); 1179} 1180 1181void 1182zio_flush(zio_t *zio, vdev_t *vd) 1183{ 1184 zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE, 0, 0, 1185 NULL, NULL, ZIO_PRIORITY_NOW, 1186 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY)); 1187} 1188 1189zio_t * 1190zio_trim(zio_t *zio, spa_t *spa, vdev_t *vd, uint64_t offset, uint64_t size) 1191{ 1192 1193 ASSERT(vd->vdev_ops->vdev_op_leaf); 1194 1195 return (zio_create(zio, spa, 0, NULL, NULL, size, NULL, NULL, 1196 ZIO_TYPE_FREE, ZIO_PRIORITY_TRIM, ZIO_FLAG_DONT_AGGREGATE | 1197 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY, 1198 vd, offset, NULL, ZIO_STAGE_OPEN, ZIO_FREE_PHYS_PIPELINE)); 1199} 1200 1201void 1202zio_shrink(zio_t *zio, uint64_t size) 1203{ 1204 ASSERT(zio->io_executor == NULL); 1205 ASSERT(zio->io_orig_size == zio->io_size); 1206 ASSERT(size <= zio->io_size); 1207 1208 /* 1209 * We don't shrink for raidz because of problems with the 1210 * reconstruction when reading back less than the block size. 1211 * Note, BP_IS_RAIDZ() assumes no compression. 1212 */ 1213 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 1214 if (!BP_IS_RAIDZ(zio->io_bp)) 1215 zio->io_orig_size = zio->io_size = size; 1216} 1217 1218/* 1219 * ========================================================================== 1220 * Prepare to read and write logical blocks 1221 * ========================================================================== 1222 */ 1223 1224static int 1225zio_read_bp_init(zio_t *zio) 1226{ 1227 blkptr_t *bp = zio->io_bp; 1228 1229 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF && 1230 zio->io_child_type == ZIO_CHILD_LOGICAL && 1231 !(zio->io_flags & ZIO_FLAG_RAW)) { 1232 uint64_t psize = 1233 BP_IS_EMBEDDED(bp) ? BPE_GET_PSIZE(bp) : BP_GET_PSIZE(bp); 1234 void *cbuf = zio_buf_alloc(psize); 1235 1236 zio_push_transform(zio, cbuf, psize, psize, zio_decompress); 1237 } 1238 1239 if (BP_IS_EMBEDDED(bp) && BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA) { 1240 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1241 decode_embedded_bp_compressed(bp, zio->io_data); 1242 } else { 1243 ASSERT(!BP_IS_EMBEDDED(bp)); 1244 } 1245 1246 if (!DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) && BP_GET_LEVEL(bp) == 0) 1247 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 1248 1249 if (BP_GET_TYPE(bp) == DMU_OT_DDT_ZAP) 1250 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 1251 1252 if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL) 1253 zio->io_pipeline = ZIO_DDT_READ_PIPELINE; 1254 1255 return (ZIO_PIPELINE_CONTINUE); 1256} 1257 1258static int 1259zio_write_bp_init(zio_t *zio) 1260{ 1261 if (!IO_IS_ALLOCATING(zio)) 1262 return (ZIO_PIPELINE_CONTINUE); 1263 1264 ASSERT(zio->io_child_type != ZIO_CHILD_DDT); 1265 1266 if (zio->io_bp_override) { 1267 blkptr_t *bp = zio->io_bp; 1268 zio_prop_t *zp = &zio->io_prop; 1269 1270 ASSERT(bp->blk_birth != zio->io_txg); 1271 ASSERT(BP_GET_DEDUP(zio->io_bp_override) == 0); 1272 1273 *bp = *zio->io_bp_override; 1274 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1275 1276 if (BP_IS_EMBEDDED(bp)) 1277 return (ZIO_PIPELINE_CONTINUE); 1278 1279 /* 1280 * If we've been overridden and nopwrite is set then 1281 * set the flag accordingly to indicate that a nopwrite 1282 * has already occurred. 1283 */ 1284 if (!BP_IS_HOLE(bp) && zp->zp_nopwrite) { 1285 ASSERT(!zp->zp_dedup); 1286 ASSERT3U(BP_GET_CHECKSUM(bp), ==, zp->zp_checksum); 1287 zio->io_flags |= ZIO_FLAG_NOPWRITE; 1288 return (ZIO_PIPELINE_CONTINUE); 1289 } 1290 1291 ASSERT(!zp->zp_nopwrite); 1292 1293 if (BP_IS_HOLE(bp) || !zp->zp_dedup) 1294 return (ZIO_PIPELINE_CONTINUE); 1295 1296 ASSERT((zio_checksum_table[zp->zp_checksum].ci_flags & 1297 ZCHECKSUM_FLAG_DEDUP) || zp->zp_dedup_verify); 1298 1299 if (BP_GET_CHECKSUM(bp) == zp->zp_checksum) { 1300 BP_SET_DEDUP(bp, 1); 1301 zio->io_pipeline |= ZIO_STAGE_DDT_WRITE; 1302 return (ZIO_PIPELINE_CONTINUE); 1303 } 1304 1305 /* 1306 * We were unable to handle this as an override bp, treat 1307 * it as a regular write I/O. 1308 */ 1309 zio->io_bp_override = NULL; 1310 *bp = zio->io_bp_orig; 1311 zio->io_pipeline = zio->io_orig_pipeline; 1312 } 1313 1314 return (ZIO_PIPELINE_CONTINUE); 1315} 1316 1317static int 1318zio_write_compress(zio_t *zio) 1319{ 1320 spa_t *spa = zio->io_spa; 1321 zio_prop_t *zp = &zio->io_prop; 1322 enum zio_compress compress = zp->zp_compress; 1323 blkptr_t *bp = zio->io_bp; 1324 uint64_t lsize = zio->io_size; 1325 uint64_t psize = lsize; 1326 int pass = 1; 1327 1328 /* 1329 * If our children haven't all reached the ready stage, 1330 * wait for them and then repeat this pipeline stage. 1331 */ 1332 if (zio_wait_for_children(zio, ZIO_CHILD_LOGICAL_BIT | 1333 ZIO_CHILD_GANG_BIT, ZIO_WAIT_READY)) { 1334 return (ZIO_PIPELINE_STOP); 1335 } 1336 1337 if (!IO_IS_ALLOCATING(zio)) 1338 return (ZIO_PIPELINE_CONTINUE); 1339 1340 if (zio->io_children_ready != NULL) { 1341 /* 1342 * Now that all our children are ready, run the callback 1343 * associated with this zio in case it wants to modify the 1344 * data to be written. 1345 */ 1346 ASSERT3U(zp->zp_level, >, 0); 1347 zio->io_children_ready(zio); 1348 } 1349 1350 ASSERT(zio->io_child_type != ZIO_CHILD_DDT); 1351 ASSERT(zio->io_bp_override == NULL); 1352 1353 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg) { 1354 /* 1355 * We're rewriting an existing block, which means we're 1356 * working on behalf of spa_sync(). For spa_sync() to 1357 * converge, it must eventually be the case that we don't 1358 * have to allocate new blocks. But compression changes 1359 * the blocksize, which forces a reallocate, and makes 1360 * convergence take longer. Therefore, after the first 1361 * few passes, stop compressing to ensure convergence. 1362 */ 1363 pass = spa_sync_pass(spa); 1364 1365 ASSERT(zio->io_txg == spa_syncing_txg(spa)); 1366 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1367 ASSERT(!BP_GET_DEDUP(bp)); 1368 1369 if (pass >= zfs_sync_pass_dont_compress) 1370 compress = ZIO_COMPRESS_OFF; 1371 1372 /* Make sure someone doesn't change their mind on overwrites */ 1373 ASSERT(BP_IS_EMBEDDED(bp) || MIN(zp->zp_copies + BP_IS_GANG(bp), 1374 spa_max_replication(spa)) == BP_GET_NDVAS(bp)); 1375 } 1376 1377 if (compress != ZIO_COMPRESS_OFF) { 1378 void *cbuf = zio_buf_alloc(lsize); 1379 psize = zio_compress_data(compress, zio->io_data, cbuf, lsize); 1380 if (psize == 0 || psize == lsize) { 1381 compress = ZIO_COMPRESS_OFF; 1382 zio_buf_free(cbuf, lsize); 1383 } else if (!zp->zp_dedup && psize <= BPE_PAYLOAD_SIZE && 1384 zp->zp_level == 0 && !DMU_OT_HAS_FILL(zp->zp_type) && 1385 spa_feature_is_enabled(spa, SPA_FEATURE_EMBEDDED_DATA)) { 1386 encode_embedded_bp_compressed(bp, 1387 cbuf, compress, lsize, psize); 1388 BPE_SET_ETYPE(bp, BP_EMBEDDED_TYPE_DATA); 1389 BP_SET_TYPE(bp, zio->io_prop.zp_type); 1390 BP_SET_LEVEL(bp, zio->io_prop.zp_level); 1391 zio_buf_free(cbuf, lsize); 1392 bp->blk_birth = zio->io_txg; 1393 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1394 ASSERT(spa_feature_is_active(spa, 1395 SPA_FEATURE_EMBEDDED_DATA)); 1396 return (ZIO_PIPELINE_CONTINUE); 1397 } else { 1398 /* 1399 * Round up compressed size up to the ashift 1400 * of the smallest-ashift device, and zero the tail. 1401 * This ensures that the compressed size of the BP 1402 * (and thus compressratio property) are correct, 1403 * in that we charge for the padding used to fill out 1404 * the last sector. 1405 */ 1406 ASSERT3U(spa->spa_min_ashift, >=, SPA_MINBLOCKSHIFT); 1407 size_t rounded = (size_t)P2ROUNDUP(psize, 1408 1ULL << spa->spa_min_ashift); 1409 if (rounded >= lsize) { 1410 compress = ZIO_COMPRESS_OFF; 1411 zio_buf_free(cbuf, lsize); 1412 psize = lsize; 1413 } else { 1414 bzero((char *)cbuf + psize, rounded - psize); 1415 psize = rounded; 1416 zio_push_transform(zio, cbuf, 1417 psize, lsize, NULL); 1418 } 1419 } 1420 1421 /* 1422 * We were unable to handle this as an override bp, treat 1423 * it as a regular write I/O. 1424 */ 1425 zio->io_bp_override = NULL; 1426 *bp = zio->io_bp_orig; 1427 zio->io_pipeline = zio->io_orig_pipeline; 1428 } 1429 1430 /* 1431 * The final pass of spa_sync() must be all rewrites, but the first 1432 * few passes offer a trade-off: allocating blocks defers convergence, 1433 * but newly allocated blocks are sequential, so they can be written 1434 * to disk faster. Therefore, we allow the first few passes of 1435 * spa_sync() to allocate new blocks, but force rewrites after that. 1436 * There should only be a handful of blocks after pass 1 in any case. 1437 */ 1438 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg && 1439 BP_GET_PSIZE(bp) == psize && 1440 pass >= zfs_sync_pass_rewrite) { 1441 ASSERT(psize != 0); 1442 enum zio_stage gang_stages = zio->io_pipeline & ZIO_GANG_STAGES; 1443 zio->io_pipeline = ZIO_REWRITE_PIPELINE | gang_stages; 1444 zio->io_flags |= ZIO_FLAG_IO_REWRITE; 1445 } else { 1446 BP_ZERO(bp); 1447 zio->io_pipeline = ZIO_WRITE_PIPELINE; 1448 } 1449 1450 if (psize == 0) { 1451 if (zio->io_bp_orig.blk_birth != 0 && 1452 spa_feature_is_active(spa, SPA_FEATURE_HOLE_BIRTH)) { 1453 BP_SET_LSIZE(bp, lsize); 1454 BP_SET_TYPE(bp, zp->zp_type); 1455 BP_SET_LEVEL(bp, zp->zp_level); 1456 BP_SET_BIRTH(bp, zio->io_txg, 0); 1457 } 1458 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1459 } else { 1460 ASSERT(zp->zp_checksum != ZIO_CHECKSUM_GANG_HEADER); 1461 BP_SET_LSIZE(bp, lsize); 1462 BP_SET_TYPE(bp, zp->zp_type); 1463 BP_SET_LEVEL(bp, zp->zp_level); 1464 BP_SET_PSIZE(bp, psize); 1465 BP_SET_COMPRESS(bp, compress); 1466 BP_SET_CHECKSUM(bp, zp->zp_checksum); 1467 BP_SET_DEDUP(bp, zp->zp_dedup); 1468 BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER); 1469 if (zp->zp_dedup) { 1470 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1471 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1472 zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE; 1473 } 1474 if (zp->zp_nopwrite) { 1475 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1476 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1477 zio->io_pipeline |= ZIO_STAGE_NOP_WRITE; 1478 } 1479 } 1480 return (ZIO_PIPELINE_CONTINUE); 1481} 1482 1483static int 1484zio_free_bp_init(zio_t *zio) 1485{ 1486 blkptr_t *bp = zio->io_bp; 1487 1488 if (zio->io_child_type == ZIO_CHILD_LOGICAL) { 1489 if (BP_GET_DEDUP(bp)) 1490 zio->io_pipeline = ZIO_DDT_FREE_PIPELINE; 1491 } 1492 1493 return (ZIO_PIPELINE_CONTINUE); 1494} 1495 1496/* 1497 * ========================================================================== 1498 * Execute the I/O pipeline 1499 * ========================================================================== 1500 */ 1501 1502static void 1503zio_taskq_dispatch(zio_t *zio, zio_taskq_type_t q, boolean_t cutinline) 1504{ 1505 spa_t *spa = zio->io_spa; 1506 zio_type_t t = zio->io_type; 1507 int flags = (cutinline ? TQ_FRONT : 0); 1508 1509 ASSERT(q == ZIO_TASKQ_ISSUE || q == ZIO_TASKQ_INTERRUPT); 1510 1511 /* 1512 * If we're a config writer or a probe, the normal issue and 1513 * interrupt threads may all be blocked waiting for the config lock. 1514 * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL. 1515 */ 1516 if (zio->io_flags & (ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_PROBE)) 1517 t = ZIO_TYPE_NULL; 1518 1519 /* 1520 * A similar issue exists for the L2ARC write thread until L2ARC 2.0. 1521 */ 1522 if (t == ZIO_TYPE_WRITE && zio->io_vd && zio->io_vd->vdev_aux) 1523 t = ZIO_TYPE_NULL; 1524 1525 /* 1526 * If this is a high priority I/O, then use the high priority taskq if 1527 * available. 1528 */ 1529 if (zio->io_priority == ZIO_PRIORITY_NOW && 1530 spa->spa_zio_taskq[t][q + 1].stqs_count != 0) 1531 q++; 1532 1533 ASSERT3U(q, <, ZIO_TASKQ_TYPES); 1534 1535 /* 1536 * NB: We are assuming that the zio can only be dispatched 1537 * to a single taskq at a time. It would be a grievous error 1538 * to dispatch the zio to another taskq at the same time. 1539 */ 1540#if defined(illumos) || !defined(_KERNEL) 1541 ASSERT(zio->io_tqent.tqent_next == NULL); 1542#else 1543 ASSERT(zio->io_tqent.tqent_task.ta_pending == 0); 1544#endif 1545 spa_taskq_dispatch_ent(spa, t, q, (task_func_t *)zio_execute, zio, 1546 flags, &zio->io_tqent); 1547} 1548 1549static boolean_t 1550zio_taskq_member(zio_t *zio, zio_taskq_type_t q) 1551{ 1552 kthread_t *executor = zio->io_executor; 1553 spa_t *spa = zio->io_spa; 1554 1555 for (zio_type_t t = 0; t < ZIO_TYPES; t++) { 1556 spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q]; 1557 uint_t i; 1558 for (i = 0; i < tqs->stqs_count; i++) { 1559 if (taskq_member(tqs->stqs_taskq[i], executor)) 1560 return (B_TRUE); 1561 } 1562 } 1563 1564 return (B_FALSE); 1565} 1566 1567static int 1568zio_issue_async(zio_t *zio) 1569{ 1570 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 1571 1572 return (ZIO_PIPELINE_STOP); 1573} 1574 1575void 1576zio_interrupt(zio_t *zio) 1577{ 1578 zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE); 1579} 1580 1581void 1582zio_delay_interrupt(zio_t *zio) 1583{ 1584 /* 1585 * The timeout_generic() function isn't defined in userspace, so 1586 * rather than trying to implement the function, the zio delay 1587 * functionality has been disabled for userspace builds. 1588 */ 1589 1590#ifdef _KERNEL 1591 /* 1592 * If io_target_timestamp is zero, then no delay has been registered 1593 * for this IO, thus jump to the end of this function and "skip" the 1594 * delay; issuing it directly to the zio layer. 1595 */ 1596 if (zio->io_target_timestamp != 0) { 1597 hrtime_t now = gethrtime(); 1598 1599 if (now >= zio->io_target_timestamp) { 1600 /* 1601 * This IO has already taken longer than the target 1602 * delay to complete, so we don't want to delay it 1603 * any longer; we "miss" the delay and issue it 1604 * directly to the zio layer. This is likely due to 1605 * the target latency being set to a value less than 1606 * the underlying hardware can satisfy (e.g. delay 1607 * set to 1ms, but the disks take 10ms to complete an 1608 * IO request). 1609 */ 1610 1611 DTRACE_PROBE2(zio__delay__miss, zio_t *, zio, 1612 hrtime_t, now); 1613 1614 zio_interrupt(zio); 1615 } else { 1616 hrtime_t diff = zio->io_target_timestamp - now; 1617 1618 DTRACE_PROBE3(zio__delay__hit, zio_t *, zio, 1619 hrtime_t, now, hrtime_t, diff); 1620 1621 (void) timeout_generic(CALLOUT_NORMAL, 1622 (void (*)(void *))zio_interrupt, zio, diff, 1, 0); 1623 } 1624 1625 return; 1626 } 1627#endif 1628 1629 DTRACE_PROBE1(zio__delay__skip, zio_t *, zio); 1630 zio_interrupt(zio); 1631} 1632 1633/* 1634 * Execute the I/O pipeline until one of the following occurs: 1635 * 1636 * (1) the I/O completes 1637 * (2) the pipeline stalls waiting for dependent child I/Os 1638 * (3) the I/O issues, so we're waiting for an I/O completion interrupt 1639 * (4) the I/O is delegated by vdev-level caching or aggregation 1640 * (5) the I/O is deferred due to vdev-level queueing 1641 * (6) the I/O is handed off to another thread. 1642 * 1643 * In all cases, the pipeline stops whenever there's no CPU work; it never 1644 * burns a thread in cv_wait(). 1645 * 1646 * There's no locking on io_stage because there's no legitimate way 1647 * for multiple threads to be attempting to process the same I/O. 1648 */ 1649static zio_pipe_stage_t *zio_pipeline[]; 1650 1651void 1652zio_execute(zio_t *zio) 1653{ 1654 zio->io_executor = curthread; 1655 1656 ASSERT3U(zio->io_queued_timestamp, >, 0); 1657 1658 while (zio->io_stage < ZIO_STAGE_DONE) { 1659 enum zio_stage pipeline = zio->io_pipeline; 1660 enum zio_stage stage = zio->io_stage; 1661 int rv; 1662 1663 ASSERT(!MUTEX_HELD(&zio->io_lock)); 1664 ASSERT(ISP2(stage)); 1665 ASSERT(zio->io_stall == NULL); 1666 1667 do { 1668 stage <<= 1; 1669 } while ((stage & pipeline) == 0); 1670 1671 ASSERT(stage <= ZIO_STAGE_DONE); 1672 1673 /* 1674 * If we are in interrupt context and this pipeline stage 1675 * will grab a config lock that is held across I/O, 1676 * or may wait for an I/O that needs an interrupt thread 1677 * to complete, issue async to avoid deadlock. 1678 * 1679 * For VDEV_IO_START, we cut in line so that the io will 1680 * be sent to disk promptly. 1681 */ 1682 if ((stage & ZIO_BLOCKING_STAGES) && zio->io_vd == NULL && 1683 zio_taskq_member(zio, ZIO_TASKQ_INTERRUPT)) { 1684 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ? 1685 zio_requeue_io_start_cut_in_line : B_FALSE; 1686 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut); 1687 return; 1688 } 1689 1690 zio->io_stage = stage; 1691 zio->io_pipeline_trace |= zio->io_stage; 1692 rv = zio_pipeline[highbit64(stage) - 1](zio); 1693 1694 if (rv == ZIO_PIPELINE_STOP) 1695 return; 1696 1697 ASSERT(rv == ZIO_PIPELINE_CONTINUE); 1698 } 1699} 1700 1701/* 1702 * ========================================================================== 1703 * Initiate I/O, either sync or async 1704 * ========================================================================== 1705 */ 1706int 1707zio_wait(zio_t *zio) 1708{ 1709 int error; 1710 1711 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 1712 ASSERT(zio->io_executor == NULL); 1713 1714 zio->io_waiter = curthread; 1715 ASSERT0(zio->io_queued_timestamp); 1716 zio->io_queued_timestamp = gethrtime(); 1717 1718 zio_execute(zio); 1719 1720 mutex_enter(&zio->io_lock); 1721 while (zio->io_executor != NULL) 1722 cv_wait(&zio->io_cv, &zio->io_lock); 1723 mutex_exit(&zio->io_lock); 1724 1725 error = zio->io_error; 1726 zio_destroy(zio); 1727 1728 return (error); 1729} 1730 1731void 1732zio_nowait(zio_t *zio) 1733{ 1734 ASSERT(zio->io_executor == NULL); 1735 1736 if (zio->io_child_type == ZIO_CHILD_LOGICAL && 1737 zio_unique_parent(zio) == NULL) { 1738 /* 1739 * This is a logical async I/O with no parent to wait for it. 1740 * We add it to the spa_async_root_zio "Godfather" I/O which 1741 * will ensure they complete prior to unloading the pool. 1742 */ 1743 spa_t *spa = zio->io_spa; 1744 1745 zio_add_child(spa->spa_async_zio_root[CPU_SEQID], zio); 1746 } 1747 1748 ASSERT0(zio->io_queued_timestamp); 1749 zio->io_queued_timestamp = gethrtime(); 1750 zio_execute(zio); 1751} 1752 1753/* 1754 * ========================================================================== 1755 * Reexecute or suspend/resume failed I/O 1756 * ========================================================================== 1757 */ 1758 1759static void 1760zio_reexecute(zio_t *pio) 1761{ 1762 zio_t *cio, *cio_next; 1763 1764 ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL); 1765 ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN); 1766 ASSERT(pio->io_gang_leader == NULL); 1767 ASSERT(pio->io_gang_tree == NULL); 1768 1769 pio->io_flags = pio->io_orig_flags; 1770 pio->io_stage = pio->io_orig_stage; 1771 pio->io_pipeline = pio->io_orig_pipeline; 1772 pio->io_reexecute = 0; 1773 pio->io_flags |= ZIO_FLAG_REEXECUTED; 1774 pio->io_pipeline_trace = 0; 1775 pio->io_error = 0; 1776 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1777 pio->io_state[w] = 0; 1778 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 1779 pio->io_child_error[c] = 0; 1780 1781 if (IO_IS_ALLOCATING(pio)) 1782 BP_ZERO(pio->io_bp); 1783 1784 /* 1785 * As we reexecute pio's children, new children could be created. 1786 * New children go to the head of pio's io_child_list, however, 1787 * so we will (correctly) not reexecute them. The key is that 1788 * the remainder of pio's io_child_list, from 'cio_next' onward, 1789 * cannot be affected by any side effects of reexecuting 'cio'. 1790 */ 1791 zio_link_t *zl = NULL; 1792 for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) { 1793 cio_next = zio_walk_children(pio, &zl); 1794 mutex_enter(&pio->io_lock); 1795 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1796 pio->io_children[cio->io_child_type][w]++; 1797 mutex_exit(&pio->io_lock); 1798 zio_reexecute(cio); 1799 } 1800 1801 /* 1802 * Now that all children have been reexecuted, execute the parent. 1803 * We don't reexecute "The Godfather" I/O here as it's the 1804 * responsibility of the caller to wait on him. 1805 */ 1806 if (!(pio->io_flags & ZIO_FLAG_GODFATHER)) { 1807 pio->io_queued_timestamp = gethrtime(); 1808 zio_execute(pio); 1809 } 1810} 1811 1812void 1813zio_suspend(spa_t *spa, zio_t *zio) 1814{ 1815 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC) 1816 fm_panic("Pool '%s' has encountered an uncorrectable I/O " 1817 "failure and the failure mode property for this pool " 1818 "is set to panic.", spa_name(spa)); 1819 1820 zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL, NULL, 0, 0); 1821 1822 mutex_enter(&spa->spa_suspend_lock); 1823 1824 if (spa->spa_suspend_zio_root == NULL) 1825 spa->spa_suspend_zio_root = zio_root(spa, NULL, NULL, 1826 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | 1827 ZIO_FLAG_GODFATHER); 1828 1829 spa->spa_suspended = B_TRUE; 1830 1831 if (zio != NULL) { 1832 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 1833 ASSERT(zio != spa->spa_suspend_zio_root); 1834 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1835 ASSERT(zio_unique_parent(zio) == NULL); 1836 ASSERT(zio->io_stage == ZIO_STAGE_DONE); 1837 zio_add_child(spa->spa_suspend_zio_root, zio); 1838 } 1839 1840 mutex_exit(&spa->spa_suspend_lock); 1841} 1842 1843int 1844zio_resume(spa_t *spa) 1845{ 1846 zio_t *pio; 1847 1848 /* 1849 * Reexecute all previously suspended i/o. 1850 */ 1851 mutex_enter(&spa->spa_suspend_lock); 1852 spa->spa_suspended = B_FALSE; 1853 cv_broadcast(&spa->spa_suspend_cv); 1854 pio = spa->spa_suspend_zio_root; 1855 spa->spa_suspend_zio_root = NULL; 1856 mutex_exit(&spa->spa_suspend_lock); 1857 1858 if (pio == NULL) 1859 return (0); 1860 1861 zio_reexecute(pio); 1862 return (zio_wait(pio)); 1863} 1864 1865void 1866zio_resume_wait(spa_t *spa) 1867{ 1868 mutex_enter(&spa->spa_suspend_lock); 1869 while (spa_suspended(spa)) 1870 cv_wait(&spa->spa_suspend_cv, &spa->spa_suspend_lock); 1871 mutex_exit(&spa->spa_suspend_lock); 1872} 1873 1874/* 1875 * ========================================================================== 1876 * Gang blocks. 1877 * 1878 * A gang block is a collection of small blocks that looks to the DMU 1879 * like one large block. When zio_dva_allocate() cannot find a block 1880 * of the requested size, due to either severe fragmentation or the pool 1881 * being nearly full, it calls zio_write_gang_block() to construct the 1882 * block from smaller fragments. 1883 * 1884 * A gang block consists of a gang header (zio_gbh_phys_t) and up to 1885 * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like 1886 * an indirect block: it's an array of block pointers. It consumes 1887 * only one sector and hence is allocatable regardless of fragmentation. 1888 * The gang header's bps point to its gang members, which hold the data. 1889 * 1890 * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg> 1891 * as the verifier to ensure uniqueness of the SHA256 checksum. 1892 * Critically, the gang block bp's blk_cksum is the checksum of the data, 1893 * not the gang header. This ensures that data block signatures (needed for 1894 * deduplication) are independent of how the block is physically stored. 1895 * 1896 * Gang blocks can be nested: a gang member may itself be a gang block. 1897 * Thus every gang block is a tree in which root and all interior nodes are 1898 * gang headers, and the leaves are normal blocks that contain user data. 1899 * The root of the gang tree is called the gang leader. 1900 * 1901 * To perform any operation (read, rewrite, free, claim) on a gang block, 1902 * zio_gang_assemble() first assembles the gang tree (minus data leaves) 1903 * in the io_gang_tree field of the original logical i/o by recursively 1904 * reading the gang leader and all gang headers below it. This yields 1905 * an in-core tree containing the contents of every gang header and the 1906 * bps for every constituent of the gang block. 1907 * 1908 * With the gang tree now assembled, zio_gang_issue() just walks the gang tree 1909 * and invokes a callback on each bp. To free a gang block, zio_gang_issue() 1910 * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp. 1911 * zio_claim_gang() provides a similarly trivial wrapper for zio_claim(). 1912 * zio_read_gang() is a wrapper around zio_read() that omits reading gang 1913 * headers, since we already have those in io_gang_tree. zio_rewrite_gang() 1914 * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite() 1915 * of the gang header plus zio_checksum_compute() of the data to update the 1916 * gang header's blk_cksum as described above. 1917 * 1918 * The two-phase assemble/issue model solves the problem of partial failure -- 1919 * what if you'd freed part of a gang block but then couldn't read the 1920 * gang header for another part? Assembling the entire gang tree first 1921 * ensures that all the necessary gang header I/O has succeeded before 1922 * starting the actual work of free, claim, or write. Once the gang tree 1923 * is assembled, free and claim are in-memory operations that cannot fail. 1924 * 1925 * In the event that a gang write fails, zio_dva_unallocate() walks the 1926 * gang tree to immediately free (i.e. insert back into the space map) 1927 * everything we've allocated. This ensures that we don't get ENOSPC 1928 * errors during repeated suspend/resume cycles due to a flaky device. 1929 * 1930 * Gang rewrites only happen during sync-to-convergence. If we can't assemble 1931 * the gang tree, we won't modify the block, so we can safely defer the free 1932 * (knowing that the block is still intact). If we *can* assemble the gang 1933 * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free 1934 * each constituent bp and we can allocate a new block on the next sync pass. 1935 * 1936 * In all cases, the gang tree allows complete recovery from partial failure. 1937 * ========================================================================== 1938 */ 1939 1940static zio_t * 1941zio_read_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1942{ 1943 if (gn != NULL) 1944 return (pio); 1945 1946 return (zio_read(pio, pio->io_spa, bp, data, BP_GET_PSIZE(bp), 1947 NULL, NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 1948 &pio->io_bookmark)); 1949} 1950 1951zio_t * 1952zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1953{ 1954 zio_t *zio; 1955 1956 if (gn != NULL) { 1957 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1958 gn->gn_gbh, SPA_GANGBLOCKSIZE, NULL, NULL, pio->io_priority, 1959 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1960 /* 1961 * As we rewrite each gang header, the pipeline will compute 1962 * a new gang block header checksum for it; but no one will 1963 * compute a new data checksum, so we do that here. The one 1964 * exception is the gang leader: the pipeline already computed 1965 * its data checksum because that stage precedes gang assembly. 1966 * (Presently, nothing actually uses interior data checksums; 1967 * this is just good hygiene.) 1968 */ 1969 if (gn != pio->io_gang_leader->io_gang_tree) { 1970 zio_checksum_compute(zio, BP_GET_CHECKSUM(bp), 1971 data, BP_GET_PSIZE(bp)); 1972 } 1973 /* 1974 * If we are here to damage data for testing purposes, 1975 * leave the GBH alone so that we can detect the damage. 1976 */ 1977 if (pio->io_gang_leader->io_flags & ZIO_FLAG_INDUCE_DAMAGE) 1978 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 1979 } else { 1980 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1981 data, BP_GET_PSIZE(bp), NULL, NULL, pio->io_priority, 1982 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1983 } 1984 1985 return (zio); 1986} 1987 1988/* ARGSUSED */ 1989zio_t * 1990zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1991{ 1992 return (zio_free_sync(pio, pio->io_spa, pio->io_txg, bp, 1993 BP_IS_GANG(bp) ? SPA_GANGBLOCKSIZE : BP_GET_PSIZE(bp), 1994 ZIO_GANG_CHILD_FLAGS(pio))); 1995} 1996 1997/* ARGSUSED */ 1998zio_t * 1999zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 2000{ 2001 return (zio_claim(pio, pio->io_spa, pio->io_txg, bp, 2002 NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio))); 2003} 2004 2005static zio_gang_issue_func_t *zio_gang_issue_func[ZIO_TYPES] = { 2006 NULL, 2007 zio_read_gang, 2008 zio_rewrite_gang, 2009 zio_free_gang, 2010 zio_claim_gang, 2011 NULL 2012}; 2013 2014static void zio_gang_tree_assemble_done(zio_t *zio); 2015 2016static zio_gang_node_t * 2017zio_gang_node_alloc(zio_gang_node_t **gnpp) 2018{ 2019 zio_gang_node_t *gn; 2020 2021 ASSERT(*gnpp == NULL); 2022 2023 gn = kmem_zalloc(sizeof (*gn), KM_SLEEP); 2024 gn->gn_gbh = zio_buf_alloc(SPA_GANGBLOCKSIZE); 2025 *gnpp = gn; 2026 2027 return (gn); 2028} 2029 2030static void 2031zio_gang_node_free(zio_gang_node_t **gnpp) 2032{ 2033 zio_gang_node_t *gn = *gnpp; 2034 2035 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 2036 ASSERT(gn->gn_child[g] == NULL); 2037 2038 zio_buf_free(gn->gn_gbh, SPA_GANGBLOCKSIZE); 2039 kmem_free(gn, sizeof (*gn)); 2040 *gnpp = NULL; 2041} 2042 2043static void 2044zio_gang_tree_free(zio_gang_node_t **gnpp) 2045{ 2046 zio_gang_node_t *gn = *gnpp; 2047 2048 if (gn == NULL) 2049 return; 2050 2051 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 2052 zio_gang_tree_free(&gn->gn_child[g]); 2053 2054 zio_gang_node_free(gnpp); 2055} 2056 2057static void 2058zio_gang_tree_assemble(zio_t *gio, blkptr_t *bp, zio_gang_node_t **gnpp) 2059{ 2060 zio_gang_node_t *gn = zio_gang_node_alloc(gnpp); 2061 2062 ASSERT(gio->io_gang_leader == gio); 2063 ASSERT(BP_IS_GANG(bp)); 2064 2065 zio_nowait(zio_read(gio, gio->io_spa, bp, gn->gn_gbh, 2066 SPA_GANGBLOCKSIZE, zio_gang_tree_assemble_done, gn, 2067 gio->io_priority, ZIO_GANG_CHILD_FLAGS(gio), &gio->io_bookmark)); 2068} 2069 2070static void 2071zio_gang_tree_assemble_done(zio_t *zio) 2072{ 2073 zio_t *gio = zio->io_gang_leader; 2074 zio_gang_node_t *gn = zio->io_private; 2075 blkptr_t *bp = zio->io_bp; 2076 2077 ASSERT(gio == zio_unique_parent(zio)); 2078 ASSERT(zio->io_child_count == 0); 2079 2080 if (zio->io_error) 2081 return; 2082 2083 if (BP_SHOULD_BYTESWAP(bp)) 2084 byteswap_uint64_array(zio->io_data, zio->io_size); 2085 2086 ASSERT(zio->io_data == gn->gn_gbh); 2087 ASSERT(zio->io_size == SPA_GANGBLOCKSIZE); 2088 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 2089 2090 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 2091 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 2092 if (!BP_IS_GANG(gbp)) 2093 continue; 2094 zio_gang_tree_assemble(gio, gbp, &gn->gn_child[g]); 2095 } 2096} 2097 2098static void 2099zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, void *data) 2100{ 2101 zio_t *gio = pio->io_gang_leader; 2102 zio_t *zio; 2103 2104 ASSERT(BP_IS_GANG(bp) == !!gn); 2105 ASSERT(BP_GET_CHECKSUM(bp) == BP_GET_CHECKSUM(gio->io_bp)); 2106 ASSERT(BP_GET_LSIZE(bp) == BP_GET_PSIZE(bp) || gn == gio->io_gang_tree); 2107 2108 /* 2109 * If you're a gang header, your data is in gn->gn_gbh. 2110 * If you're a gang member, your data is in 'data' and gn == NULL. 2111 */ 2112 zio = zio_gang_issue_func[gio->io_type](pio, bp, gn, data); 2113 2114 if (gn != NULL) { 2115 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 2116 2117 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 2118 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 2119 if (BP_IS_HOLE(gbp)) 2120 continue; 2121 zio_gang_tree_issue(zio, gn->gn_child[g], gbp, data); 2122 data = (char *)data + BP_GET_PSIZE(gbp); 2123 } 2124 } 2125 2126 if (gn == gio->io_gang_tree && gio->io_data != NULL) 2127 ASSERT3P((char *)gio->io_data + gio->io_size, ==, data); 2128 2129 if (zio != pio) 2130 zio_nowait(zio); 2131} 2132 2133static int 2134zio_gang_assemble(zio_t *zio) 2135{ 2136 blkptr_t *bp = zio->io_bp; 2137 2138 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == NULL); 2139 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2140 2141 zio->io_gang_leader = zio; 2142 2143 zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree); 2144 2145 return (ZIO_PIPELINE_CONTINUE); 2146} 2147 2148static int 2149zio_gang_issue(zio_t *zio) 2150{ 2151 blkptr_t *bp = zio->io_bp; 2152 2153 if (zio_wait_for_children(zio, ZIO_CHILD_GANG_BIT, ZIO_WAIT_DONE)) { 2154 return (ZIO_PIPELINE_STOP); 2155 } 2156 2157 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio); 2158 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2159 2160 if (zio->io_child_error[ZIO_CHILD_GANG] == 0) 2161 zio_gang_tree_issue(zio, zio->io_gang_tree, bp, zio->io_data); 2162 else 2163 zio_gang_tree_free(&zio->io_gang_tree); 2164 2165 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2166 2167 return (ZIO_PIPELINE_CONTINUE); 2168} 2169 2170static void 2171zio_write_gang_member_ready(zio_t *zio) 2172{ 2173 zio_t *pio = zio_unique_parent(zio); 2174 zio_t *gio = zio->io_gang_leader; 2175 dva_t *cdva = zio->io_bp->blk_dva; 2176 dva_t *pdva = pio->io_bp->blk_dva; 2177 uint64_t asize; 2178 2179 if (BP_IS_HOLE(zio->io_bp)) 2180 return; 2181 2182 ASSERT(BP_IS_HOLE(&zio->io_bp_orig)); 2183 2184 ASSERT(zio->io_child_type == ZIO_CHILD_GANG); 2185 ASSERT3U(zio->io_prop.zp_copies, ==, gio->io_prop.zp_copies); 2186 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp)); 2187 ASSERT3U(pio->io_prop.zp_copies, <=, BP_GET_NDVAS(pio->io_bp)); 2188 ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp)); 2189 2190 mutex_enter(&pio->io_lock); 2191 for (int d = 0; d < BP_GET_NDVAS(zio->io_bp); d++) { 2192 ASSERT(DVA_GET_GANG(&pdva[d])); 2193 asize = DVA_GET_ASIZE(&pdva[d]); 2194 asize += DVA_GET_ASIZE(&cdva[d]); 2195 DVA_SET_ASIZE(&pdva[d], asize); 2196 } 2197 mutex_exit(&pio->io_lock); 2198} 2199 2200static int 2201zio_write_gang_block(zio_t *pio) 2202{ 2203 spa_t *spa = pio->io_spa; 2204 metaslab_class_t *mc = spa_normal_class(spa); 2205 blkptr_t *bp = pio->io_bp; 2206 zio_t *gio = pio->io_gang_leader; 2207 zio_t *zio; 2208 zio_gang_node_t *gn, **gnpp; 2209 zio_gbh_phys_t *gbh; 2210 uint64_t txg = pio->io_txg; 2211 uint64_t resid = pio->io_size; 2212 uint64_t lsize; 2213 int copies = gio->io_prop.zp_copies; 2214 int gbh_copies = MIN(copies + 1, spa_max_replication(spa)); 2215 zio_prop_t zp; 2216 int error; 2217 2218 int flags = METASLAB_HINTBP_FAVOR | METASLAB_GANG_HEADER; 2219 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 2220 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 2221 ASSERT(!(pio->io_flags & ZIO_FLAG_NODATA)); 2222 2223 flags |= METASLAB_ASYNC_ALLOC; 2224 VERIFY(refcount_held(&mc->mc_alloc_slots, pio)); 2225 2226 /* 2227 * The logical zio has already placed a reservation for 2228 * 'copies' allocation slots but gang blocks may require 2229 * additional copies. These additional copies 2230 * (i.e. gbh_copies - copies) are guaranteed to succeed 2231 * since metaslab_class_throttle_reserve() always allows 2232 * additional reservations for gang blocks. 2233 */ 2234 VERIFY(metaslab_class_throttle_reserve(mc, gbh_copies - copies, 2235 pio, flags)); 2236 } 2237 2238 error = metaslab_alloc(spa, mc, SPA_GANGBLOCKSIZE, 2239 bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp, flags, pio); 2240 if (error) { 2241 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 2242 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 2243 ASSERT(!(pio->io_flags & ZIO_FLAG_NODATA)); 2244 2245 /* 2246 * If we failed to allocate the gang block header then 2247 * we remove any additional allocation reservations that 2248 * we placed here. The original reservation will 2249 * be removed when the logical I/O goes to the ready 2250 * stage. 2251 */ 2252 metaslab_class_throttle_unreserve(mc, 2253 gbh_copies - copies, pio); 2254 } 2255 pio->io_error = error; 2256 return (ZIO_PIPELINE_CONTINUE); 2257 } 2258 2259 if (pio == gio) { 2260 gnpp = &gio->io_gang_tree; 2261 } else { 2262 gnpp = pio->io_private; 2263 ASSERT(pio->io_ready == zio_write_gang_member_ready); 2264 } 2265 2266 gn = zio_gang_node_alloc(gnpp); 2267 gbh = gn->gn_gbh; 2268 bzero(gbh, SPA_GANGBLOCKSIZE); 2269 2270 /* 2271 * Create the gang header. 2272 */ 2273 zio = zio_rewrite(pio, spa, txg, bp, gbh, SPA_GANGBLOCKSIZE, NULL, NULL, 2274 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 2275 2276 /* 2277 * Create and nowait the gang children. 2278 */ 2279 for (int g = 0; resid != 0; resid -= lsize, g++) { 2280 lsize = P2ROUNDUP(resid / (SPA_GBH_NBLKPTRS - g), 2281 SPA_MINBLOCKSIZE); 2282 ASSERT(lsize >= SPA_MINBLOCKSIZE && lsize <= resid); 2283 2284 zp.zp_checksum = gio->io_prop.zp_checksum; 2285 zp.zp_compress = ZIO_COMPRESS_OFF; 2286 zp.zp_type = DMU_OT_NONE; 2287 zp.zp_level = 0; 2288 zp.zp_copies = gio->io_prop.zp_copies; 2289 zp.zp_dedup = B_FALSE; 2290 zp.zp_dedup_verify = B_FALSE; 2291 zp.zp_nopwrite = B_FALSE; 2292 2293 zio_t *cio = zio_write(zio, spa, txg, &gbh->zg_blkptr[g], 2294 (char *)pio->io_data + (pio->io_size - resid), lsize, &zp, 2295 zio_write_gang_member_ready, NULL, NULL, NULL, 2296 &gn->gn_child[g], pio->io_priority, 2297 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 2298 2299 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 2300 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 2301 ASSERT(!(pio->io_flags & ZIO_FLAG_NODATA)); 2302 2303 /* 2304 * Gang children won't throttle but we should 2305 * account for their work, so reserve an allocation 2306 * slot for them here. 2307 */ 2308 VERIFY(metaslab_class_throttle_reserve(mc, 2309 zp.zp_copies, cio, flags)); 2310 } 2311 zio_nowait(cio); 2312 } 2313 2314 /* 2315 * Set pio's pipeline to just wait for zio to finish. 2316 */ 2317 pio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2318 2319 zio_nowait(zio); 2320 2321 return (ZIO_PIPELINE_CONTINUE); 2322} 2323 2324/* 2325 * The zio_nop_write stage in the pipeline determines if allocating a 2326 * new bp is necessary. The nopwrite feature can handle writes in 2327 * either syncing or open context (i.e. zil writes) and as a result is 2328 * mutually exclusive with dedup. 2329 * 2330 * By leveraging a cryptographically secure checksum, such as SHA256, we 2331 * can compare the checksums of the new data and the old to determine if 2332 * allocating a new block is required. Note that our requirements for 2333 * cryptographic strength are fairly weak: there can't be any accidental 2334 * hash collisions, but we don't need to be secure against intentional 2335 * (malicious) collisions. To trigger a nopwrite, you have to be able 2336 * to write the file to begin with, and triggering an incorrect (hash 2337 * collision) nopwrite is no worse than simply writing to the file. 2338 * That said, there are no known attacks against the checksum algorithms 2339 * used for nopwrite, assuming that the salt and the checksums 2340 * themselves remain secret. 2341 */ 2342static int 2343zio_nop_write(zio_t *zio) 2344{ 2345 blkptr_t *bp = zio->io_bp; 2346 blkptr_t *bp_orig = &zio->io_bp_orig; 2347 zio_prop_t *zp = &zio->io_prop; 2348 2349 ASSERT(BP_GET_LEVEL(bp) == 0); 2350 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 2351 ASSERT(zp->zp_nopwrite); 2352 ASSERT(!zp->zp_dedup); 2353 ASSERT(zio->io_bp_override == NULL); 2354 ASSERT(IO_IS_ALLOCATING(zio)); 2355 2356 /* 2357 * Check to see if the original bp and the new bp have matching 2358 * characteristics (i.e. same checksum, compression algorithms, etc). 2359 * If they don't then just continue with the pipeline which will 2360 * allocate a new bp. 2361 */ 2362 if (BP_IS_HOLE(bp_orig) || 2363 !(zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_flags & 2364 ZCHECKSUM_FLAG_NOPWRITE) || 2365 BP_GET_CHECKSUM(bp) != BP_GET_CHECKSUM(bp_orig) || 2366 BP_GET_COMPRESS(bp) != BP_GET_COMPRESS(bp_orig) || 2367 BP_GET_DEDUP(bp) != BP_GET_DEDUP(bp_orig) || 2368 zp->zp_copies != BP_GET_NDVAS(bp_orig)) 2369 return (ZIO_PIPELINE_CONTINUE); 2370 2371 /* 2372 * If the checksums match then reset the pipeline so that we 2373 * avoid allocating a new bp and issuing any I/O. 2374 */ 2375 if (ZIO_CHECKSUM_EQUAL(bp->blk_cksum, bp_orig->blk_cksum)) { 2376 ASSERT(zio_checksum_table[zp->zp_checksum].ci_flags & 2377 ZCHECKSUM_FLAG_NOPWRITE); 2378 ASSERT3U(BP_GET_PSIZE(bp), ==, BP_GET_PSIZE(bp_orig)); 2379 ASSERT3U(BP_GET_LSIZE(bp), ==, BP_GET_LSIZE(bp_orig)); 2380 ASSERT(zp->zp_compress != ZIO_COMPRESS_OFF); 2381 ASSERT(bcmp(&bp->blk_prop, &bp_orig->blk_prop, 2382 sizeof (uint64_t)) == 0); 2383 2384 *bp = *bp_orig; 2385 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2386 zio->io_flags |= ZIO_FLAG_NOPWRITE; 2387 } 2388 2389 return (ZIO_PIPELINE_CONTINUE); 2390} 2391 2392/* 2393 * ========================================================================== 2394 * Dedup 2395 * ========================================================================== 2396 */ 2397static void 2398zio_ddt_child_read_done(zio_t *zio) 2399{ 2400 blkptr_t *bp = zio->io_bp; 2401 ddt_entry_t *dde = zio->io_private; 2402 ddt_phys_t *ddp; 2403 zio_t *pio = zio_unique_parent(zio); 2404 2405 mutex_enter(&pio->io_lock); 2406 ddp = ddt_phys_select(dde, bp); 2407 if (zio->io_error == 0) 2408 ddt_phys_clear(ddp); /* this ddp doesn't need repair */ 2409 if (zio->io_error == 0 && dde->dde_repair_data == NULL) 2410 dde->dde_repair_data = zio->io_data; 2411 else 2412 zio_buf_free(zio->io_data, zio->io_size); 2413 mutex_exit(&pio->io_lock); 2414} 2415 2416static int 2417zio_ddt_read_start(zio_t *zio) 2418{ 2419 blkptr_t *bp = zio->io_bp; 2420 2421 ASSERT(BP_GET_DEDUP(bp)); 2422 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 2423 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2424 2425 if (zio->io_child_error[ZIO_CHILD_DDT]) { 2426 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2427 ddt_entry_t *dde = ddt_repair_start(ddt, bp); 2428 ddt_phys_t *ddp = dde->dde_phys; 2429 ddt_phys_t *ddp_self = ddt_phys_select(dde, bp); 2430 blkptr_t blk; 2431 2432 ASSERT(zio->io_vsd == NULL); 2433 zio->io_vsd = dde; 2434 2435 if (ddp_self == NULL) 2436 return (ZIO_PIPELINE_CONTINUE); 2437 2438 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { 2439 if (ddp->ddp_phys_birth == 0 || ddp == ddp_self) 2440 continue; 2441 ddt_bp_create(ddt->ddt_checksum, &dde->dde_key, ddp, 2442 &blk); 2443 zio_nowait(zio_read(zio, zio->io_spa, &blk, 2444 zio_buf_alloc(zio->io_size), zio->io_size, 2445 zio_ddt_child_read_done, dde, zio->io_priority, 2446 ZIO_DDT_CHILD_FLAGS(zio) | ZIO_FLAG_DONT_PROPAGATE, 2447 &zio->io_bookmark)); 2448 } 2449 return (ZIO_PIPELINE_CONTINUE); 2450 } 2451 2452 zio_nowait(zio_read(zio, zio->io_spa, bp, 2453 zio->io_data, zio->io_size, NULL, NULL, zio->io_priority, 2454 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark)); 2455 2456 return (ZIO_PIPELINE_CONTINUE); 2457} 2458 2459static int 2460zio_ddt_read_done(zio_t *zio) 2461{ 2462 blkptr_t *bp = zio->io_bp; 2463 2464 if (zio_wait_for_children(zio, ZIO_CHILD_DDT_BIT, ZIO_WAIT_DONE)) { 2465 return (ZIO_PIPELINE_STOP); 2466 } 2467 2468 ASSERT(BP_GET_DEDUP(bp)); 2469 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 2470 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2471 2472 if (zio->io_child_error[ZIO_CHILD_DDT]) { 2473 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2474 ddt_entry_t *dde = zio->io_vsd; 2475 if (ddt == NULL) { 2476 ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE); 2477 return (ZIO_PIPELINE_CONTINUE); 2478 } 2479 if (dde == NULL) { 2480 zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1; 2481 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 2482 return (ZIO_PIPELINE_STOP); 2483 } 2484 if (dde->dde_repair_data != NULL) { 2485 bcopy(dde->dde_repair_data, zio->io_data, zio->io_size); 2486 zio->io_child_error[ZIO_CHILD_DDT] = 0; 2487 } 2488 ddt_repair_done(ddt, dde); 2489 zio->io_vsd = NULL; 2490 } 2491 2492 ASSERT(zio->io_vsd == NULL); 2493 2494 return (ZIO_PIPELINE_CONTINUE); 2495} 2496 2497static boolean_t 2498zio_ddt_collision(zio_t *zio, ddt_t *ddt, ddt_entry_t *dde) 2499{ 2500 spa_t *spa = zio->io_spa; 2501 2502 /* 2503 * Note: we compare the original data, not the transformed data, 2504 * because when zio->io_bp is an override bp, we will not have 2505 * pushed the I/O transforms. That's an important optimization 2506 * because otherwise we'd compress/encrypt all dmu_sync() data twice. 2507 */ 2508 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 2509 zio_t *lio = dde->dde_lead_zio[p]; 2510 2511 if (lio != NULL) { 2512 return (lio->io_orig_size != zio->io_orig_size || 2513 bcmp(zio->io_orig_data, lio->io_orig_data, 2514 zio->io_orig_size) != 0); 2515 } 2516 } 2517 2518 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 2519 ddt_phys_t *ddp = &dde->dde_phys[p]; 2520 2521 if (ddp->ddp_phys_birth != 0) { 2522 arc_buf_t *abuf = NULL; 2523 arc_flags_t aflags = ARC_FLAG_WAIT; 2524 blkptr_t blk = *zio->io_bp; 2525 int error; 2526 2527 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth); 2528 2529 ddt_exit(ddt); 2530 2531 error = arc_read(NULL, spa, &blk, 2532 arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ, 2533 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, 2534 &aflags, &zio->io_bookmark); 2535 2536 if (error == 0) { 2537 if (arc_buf_size(abuf) != zio->io_orig_size || 2538 bcmp(abuf->b_data, zio->io_orig_data, 2539 zio->io_orig_size) != 0) 2540 error = SET_ERROR(EEXIST); 2541 arc_buf_destroy(abuf, &abuf); 2542 } 2543 2544 ddt_enter(ddt); 2545 return (error != 0); 2546 } 2547 } 2548 2549 return (B_FALSE); 2550} 2551 2552static void 2553zio_ddt_child_write_ready(zio_t *zio) 2554{ 2555 int p = zio->io_prop.zp_copies; 2556 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 2557 ddt_entry_t *dde = zio->io_private; 2558 ddt_phys_t *ddp = &dde->dde_phys[p]; 2559 zio_t *pio; 2560 2561 if (zio->io_error) 2562 return; 2563 2564 ddt_enter(ddt); 2565 2566 ASSERT(dde->dde_lead_zio[p] == zio); 2567 2568 ddt_phys_fill(ddp, zio->io_bp); 2569 2570 zio_link_t *zl = NULL; 2571 while ((pio = zio_walk_parents(zio, &zl)) != NULL) 2572 ddt_bp_fill(ddp, pio->io_bp, zio->io_txg); 2573 2574 ddt_exit(ddt); 2575} 2576 2577static void 2578zio_ddt_child_write_done(zio_t *zio) 2579{ 2580 int p = zio->io_prop.zp_copies; 2581 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 2582 ddt_entry_t *dde = zio->io_private; 2583 ddt_phys_t *ddp = &dde->dde_phys[p]; 2584 2585 ddt_enter(ddt); 2586 2587 ASSERT(ddp->ddp_refcnt == 0); 2588 ASSERT(dde->dde_lead_zio[p] == zio); 2589 dde->dde_lead_zio[p] = NULL; 2590 2591 if (zio->io_error == 0) { 2592 zio_link_t *zl = NULL; 2593 while (zio_walk_parents(zio, &zl) != NULL) 2594 ddt_phys_addref(ddp); 2595 } else { 2596 ddt_phys_clear(ddp); 2597 } 2598 2599 ddt_exit(ddt); 2600} 2601 2602static void 2603zio_ddt_ditto_write_done(zio_t *zio) 2604{ 2605 int p = DDT_PHYS_DITTO; 2606 zio_prop_t *zp = &zio->io_prop; 2607 blkptr_t *bp = zio->io_bp; 2608 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2609 ddt_entry_t *dde = zio->io_private; 2610 ddt_phys_t *ddp = &dde->dde_phys[p]; 2611 ddt_key_t *ddk = &dde->dde_key; 2612 2613 ddt_enter(ddt); 2614 2615 ASSERT(ddp->ddp_refcnt == 0); 2616 ASSERT(dde->dde_lead_zio[p] == zio); 2617 dde->dde_lead_zio[p] = NULL; 2618 2619 if (zio->io_error == 0) { 2620 ASSERT(ZIO_CHECKSUM_EQUAL(bp->blk_cksum, ddk->ddk_cksum)); 2621 ASSERT(zp->zp_copies < SPA_DVAS_PER_BP); 2622 ASSERT(zp->zp_copies == BP_GET_NDVAS(bp) - BP_IS_GANG(bp)); 2623 if (ddp->ddp_phys_birth != 0) 2624 ddt_phys_free(ddt, ddk, ddp, zio->io_txg); 2625 ddt_phys_fill(ddp, bp); 2626 } 2627 2628 ddt_exit(ddt); 2629} 2630 2631static int 2632zio_ddt_write(zio_t *zio) 2633{ 2634 spa_t *spa = zio->io_spa; 2635 blkptr_t *bp = zio->io_bp; 2636 uint64_t txg = zio->io_txg; 2637 zio_prop_t *zp = &zio->io_prop; 2638 int p = zp->zp_copies; 2639 int ditto_copies; 2640 zio_t *cio = NULL; 2641 zio_t *dio = NULL; 2642 ddt_t *ddt = ddt_select(spa, bp); 2643 ddt_entry_t *dde; 2644 ddt_phys_t *ddp; 2645 2646 ASSERT(BP_GET_DEDUP(bp)); 2647 ASSERT(BP_GET_CHECKSUM(bp) == zp->zp_checksum); 2648 ASSERT(BP_IS_HOLE(bp) || zio->io_bp_override); 2649 2650 ddt_enter(ddt); 2651 dde = ddt_lookup(ddt, bp, B_TRUE); 2652 ddp = &dde->dde_phys[p]; 2653 2654 if (zp->zp_dedup_verify && zio_ddt_collision(zio, ddt, dde)) { 2655 /* 2656 * If we're using a weak checksum, upgrade to a strong checksum 2657 * and try again. If we're already using a strong checksum, 2658 * we can't resolve it, so just convert to an ordinary write. 2659 * (And automatically e-mail a paper to Nature?) 2660 */ 2661 if (!(zio_checksum_table[zp->zp_checksum].ci_flags & 2662 ZCHECKSUM_FLAG_DEDUP)) { 2663 zp->zp_checksum = spa_dedup_checksum(spa); 2664 zio_pop_transforms(zio); 2665 zio->io_stage = ZIO_STAGE_OPEN; 2666 BP_ZERO(bp); 2667 } else { 2668 zp->zp_dedup = B_FALSE; 2669 } 2670 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2671 ddt_exit(ddt); 2672 return (ZIO_PIPELINE_CONTINUE); 2673 } 2674 2675 ditto_copies = ddt_ditto_copies_needed(ddt, dde, ddp); 2676 ASSERT(ditto_copies < SPA_DVAS_PER_BP); 2677 2678 if (ditto_copies > ddt_ditto_copies_present(dde) && 2679 dde->dde_lead_zio[DDT_PHYS_DITTO] == NULL) { 2680 zio_prop_t czp = *zp; 2681 2682 czp.zp_copies = ditto_copies; 2683 2684 /* 2685 * If we arrived here with an override bp, we won't have run 2686 * the transform stack, so we won't have the data we need to 2687 * generate a child i/o. So, toss the override bp and restart. 2688 * This is safe, because using the override bp is just an 2689 * optimization; and it's rare, so the cost doesn't matter. 2690 */ 2691 if (zio->io_bp_override) { 2692 zio_pop_transforms(zio); 2693 zio->io_stage = ZIO_STAGE_OPEN; 2694 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2695 zio->io_bp_override = NULL; 2696 BP_ZERO(bp); 2697 ddt_exit(ddt); 2698 return (ZIO_PIPELINE_CONTINUE); 2699 } 2700 2701 dio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2702 zio->io_orig_size, &czp, NULL, NULL, 2703 NULL, zio_ddt_ditto_write_done, dde, zio->io_priority, 2704 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2705 2706 zio_push_transform(dio, zio->io_data, zio->io_size, 0, NULL); 2707 dde->dde_lead_zio[DDT_PHYS_DITTO] = dio; 2708 } 2709 2710 if (ddp->ddp_phys_birth != 0 || dde->dde_lead_zio[p] != NULL) { 2711 if (ddp->ddp_phys_birth != 0) 2712 ddt_bp_fill(ddp, bp, txg); 2713 if (dde->dde_lead_zio[p] != NULL) 2714 zio_add_child(zio, dde->dde_lead_zio[p]); 2715 else 2716 ddt_phys_addref(ddp); 2717 } else if (zio->io_bp_override) { 2718 ASSERT(bp->blk_birth == txg); 2719 ASSERT(BP_EQUAL(bp, zio->io_bp_override)); 2720 ddt_phys_fill(ddp, bp); 2721 ddt_phys_addref(ddp); 2722 } else { 2723 cio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2724 zio->io_orig_size, zp, 2725 zio_ddt_child_write_ready, NULL, NULL, 2726 zio_ddt_child_write_done, dde, zio->io_priority, 2727 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2728 2729 zio_push_transform(cio, zio->io_data, zio->io_size, 0, NULL); 2730 dde->dde_lead_zio[p] = cio; 2731 } 2732 2733 ddt_exit(ddt); 2734 2735 if (cio) 2736 zio_nowait(cio); 2737 if (dio) 2738 zio_nowait(dio); 2739 2740 return (ZIO_PIPELINE_CONTINUE); 2741} 2742 2743ddt_entry_t *freedde; /* for debugging */ 2744 2745static int 2746zio_ddt_free(zio_t *zio) 2747{ 2748 spa_t *spa = zio->io_spa; 2749 blkptr_t *bp = zio->io_bp; 2750 ddt_t *ddt = ddt_select(spa, bp); 2751 ddt_entry_t *dde; 2752 ddt_phys_t *ddp; 2753 2754 ASSERT(BP_GET_DEDUP(bp)); 2755 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2756 2757 ddt_enter(ddt); 2758 freedde = dde = ddt_lookup(ddt, bp, B_TRUE); 2759 ddp = ddt_phys_select(dde, bp); 2760 ddt_phys_decref(ddp); 2761 ddt_exit(ddt); 2762 2763 return (ZIO_PIPELINE_CONTINUE); 2764} 2765 2766/* 2767 * ========================================================================== 2768 * Allocate and free blocks 2769 * ========================================================================== 2770 */ 2771 2772static zio_t * 2773zio_io_to_allocate(spa_t *spa) 2774{ 2775 zio_t *zio; 2776 2777 ASSERT(MUTEX_HELD(&spa->spa_alloc_lock)); 2778 2779 zio = avl_first(&spa->spa_alloc_tree); 2780 if (zio == NULL) 2781 return (NULL); 2782 2783 ASSERT(IO_IS_ALLOCATING(zio)); 2784 2785 /* 2786 * Try to place a reservation for this zio. If we're unable to 2787 * reserve then we throttle. 2788 */ 2789 if (!metaslab_class_throttle_reserve(spa_normal_class(spa), 2790 zio->io_prop.zp_copies, zio, 0)) { 2791 return (NULL); 2792 } 2793 2794 avl_remove(&spa->spa_alloc_tree, zio); 2795 ASSERT3U(zio->io_stage, <, ZIO_STAGE_DVA_ALLOCATE); 2796 2797 return (zio); 2798} 2799 2800static int 2801zio_dva_throttle(zio_t *zio) 2802{ 2803 spa_t *spa = zio->io_spa; 2804 zio_t *nio; 2805 2806 if (zio->io_priority == ZIO_PRIORITY_SYNC_WRITE || 2807 !spa_normal_class(zio->io_spa)->mc_alloc_throttle_enabled || 2808 zio->io_child_type == ZIO_CHILD_GANG || 2809 zio->io_flags & ZIO_FLAG_NODATA) { 2810 return (ZIO_PIPELINE_CONTINUE); 2811 } 2812 2813 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2814 2815 ASSERT3U(zio->io_queued_timestamp, >, 0); 2816 ASSERT(zio->io_stage == ZIO_STAGE_DVA_THROTTLE); 2817 2818 mutex_enter(&spa->spa_alloc_lock); 2819 2820 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 2821 avl_add(&spa->spa_alloc_tree, zio); 2822 2823 nio = zio_io_to_allocate(zio->io_spa); 2824 mutex_exit(&spa->spa_alloc_lock); 2825 2826 if (nio == zio) 2827 return (ZIO_PIPELINE_CONTINUE); 2828 2829 if (nio != NULL) { 2830 ASSERT3U(nio->io_queued_timestamp, <=, 2831 zio->io_queued_timestamp); 2832 ASSERT(nio->io_stage == ZIO_STAGE_DVA_THROTTLE); 2833 /* 2834 * We are passing control to a new zio so make sure that 2835 * it is processed by a different thread. We do this to 2836 * avoid stack overflows that can occur when parents are 2837 * throttled and children are making progress. We allow 2838 * it to go to the head of the taskq since it's already 2839 * been waiting. 2840 */ 2841 zio_taskq_dispatch(nio, ZIO_TASKQ_ISSUE, B_TRUE); 2842 } 2843 return (ZIO_PIPELINE_STOP); 2844} 2845 2846void 2847zio_allocate_dispatch(spa_t *spa) 2848{ 2849 zio_t *zio; 2850 2851 mutex_enter(&spa->spa_alloc_lock); 2852 zio = zio_io_to_allocate(spa); 2853 mutex_exit(&spa->spa_alloc_lock); 2854 if (zio == NULL) 2855 return; 2856 2857 ASSERT3U(zio->io_stage, ==, ZIO_STAGE_DVA_THROTTLE); 2858 ASSERT0(zio->io_error); 2859 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_TRUE); 2860} 2861 2862static int 2863zio_dva_allocate(zio_t *zio) 2864{ 2865 spa_t *spa = zio->io_spa; 2866 metaslab_class_t *mc = spa_normal_class(spa); 2867 blkptr_t *bp = zio->io_bp; 2868 int error; 2869 int flags = 0; 2870 2871 if (zio->io_gang_leader == NULL) { 2872 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2873 zio->io_gang_leader = zio; 2874 } 2875 2876 ASSERT(BP_IS_HOLE(bp)); 2877 ASSERT0(BP_GET_NDVAS(bp)); 2878 ASSERT3U(zio->io_prop.zp_copies, >, 0); 2879 ASSERT3U(zio->io_prop.zp_copies, <=, spa_max_replication(spa)); 2880 ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp)); 2881 2882 if (zio->io_flags & ZIO_FLAG_NODATA) { 2883 flags |= METASLAB_DONT_THROTTLE; 2884 } 2885 if (zio->io_flags & ZIO_FLAG_GANG_CHILD) { 2886 flags |= METASLAB_GANG_CHILD; 2887 } 2888 if (zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE) { 2889 flags |= METASLAB_ASYNC_ALLOC; 2890 } 2891 2892 error = metaslab_alloc(spa, mc, zio->io_size, bp, 2893 zio->io_prop.zp_copies, zio->io_txg, NULL, flags, zio); 2894 2895 if (error != 0) { 2896 spa_dbgmsg(spa, "%s: metaslab allocation failure: zio %p, " 2897 "size %llu, error %d", spa_name(spa), zio, zio->io_size, 2898 error); 2899 if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE) 2900 return (zio_write_gang_block(zio)); 2901 zio->io_error = error; 2902 } 2903 2904 return (ZIO_PIPELINE_CONTINUE); 2905} 2906 2907static int 2908zio_dva_free(zio_t *zio) 2909{ 2910 metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE); 2911 2912 return (ZIO_PIPELINE_CONTINUE); 2913} 2914 2915static int 2916zio_dva_claim(zio_t *zio) 2917{ 2918 int error; 2919 2920 error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg); 2921 if (error) 2922 zio->io_error = error; 2923 2924 return (ZIO_PIPELINE_CONTINUE); 2925} 2926 2927/* 2928 * Undo an allocation. This is used by zio_done() when an I/O fails 2929 * and we want to give back the block we just allocated. 2930 * This handles both normal blocks and gang blocks. 2931 */ 2932static void 2933zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp) 2934{ 2935 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp)); 2936 ASSERT(zio->io_bp_override == NULL); 2937 2938 if (!BP_IS_HOLE(bp)) 2939 metaslab_free(zio->io_spa, bp, bp->blk_birth, B_TRUE); 2940 2941 if (gn != NULL) { 2942 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 2943 zio_dva_unallocate(zio, gn->gn_child[g], 2944 &gn->gn_gbh->zg_blkptr[g]); 2945 } 2946 } 2947} 2948 2949/* 2950 * Try to allocate an intent log block. Return 0 on success, errno on failure. 2951 */ 2952int 2953zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp, blkptr_t *old_bp, 2954 uint64_t size, boolean_t *slog) 2955{ 2956 int error = 1; 2957 2958 ASSERT(txg > spa_syncing_txg(spa)); 2959 2960 error = metaslab_alloc(spa, spa_log_class(spa), size, 2961 new_bp, 1, txg, old_bp, METASLAB_HINTBP_AVOID, NULL); 2962 if (error == 0) { 2963 *slog = TRUE; 2964 } else { 2965 error = metaslab_alloc(spa, spa_normal_class(spa), size, 2966 new_bp, 1, txg, old_bp, METASLAB_HINTBP_AVOID, NULL); 2967 if (error == 0) 2968 *slog = FALSE; 2969 } 2970 2971 if (error == 0) { 2972 BP_SET_LSIZE(new_bp, size); 2973 BP_SET_PSIZE(new_bp, size); 2974 BP_SET_COMPRESS(new_bp, ZIO_COMPRESS_OFF); 2975 BP_SET_CHECKSUM(new_bp, 2976 spa_version(spa) >= SPA_VERSION_SLIM_ZIL 2977 ? ZIO_CHECKSUM_ZILOG2 : ZIO_CHECKSUM_ZILOG); 2978 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG); 2979 BP_SET_LEVEL(new_bp, 0); 2980 BP_SET_DEDUP(new_bp, 0); 2981 BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER); 2982 } 2983 2984 return (error); 2985} 2986 2987/* 2988 * Free an intent log block. 2989 */ 2990void 2991zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp) 2992{ 2993 ASSERT(BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG); 2994 ASSERT(!BP_IS_GANG(bp)); 2995 2996 zio_free(spa, txg, bp); 2997} 2998 2999/* 3000 * ========================================================================== 3001 * Read, write and delete to physical devices 3002 * ========================================================================== 3003 */ 3004 3005 3006/* 3007 * Issue an I/O to the underlying vdev. Typically the issue pipeline 3008 * stops after this stage and will resume upon I/O completion. 3009 * However, there are instances where the vdev layer may need to 3010 * continue the pipeline when an I/O was not issued. Since the I/O 3011 * that was sent to the vdev layer might be different than the one 3012 * currently active in the pipeline (see vdev_queue_io()), we explicitly 3013 * force the underlying vdev layers to call either zio_execute() or 3014 * zio_interrupt() to ensure that the pipeline continues with the correct I/O. 3015 */ 3016static int 3017zio_vdev_io_start(zio_t *zio) 3018{ 3019 vdev_t *vd = zio->io_vd; 3020 uint64_t align; 3021 spa_t *spa = zio->io_spa; 3022 int ret; 3023 3024 ASSERT(zio->io_error == 0); 3025 ASSERT(zio->io_child_error[ZIO_CHILD_VDEV] == 0); 3026 3027 if (vd == NULL) { 3028 if (!(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 3029 spa_config_enter(spa, SCL_ZIO, zio, RW_READER); 3030 3031 /* 3032 * The mirror_ops handle multiple DVAs in a single BP. 3033 */ 3034 vdev_mirror_ops.vdev_op_io_start(zio); 3035 return (ZIO_PIPELINE_STOP); 3036 } 3037 3038 if (vd->vdev_ops->vdev_op_leaf && zio->io_type == ZIO_TYPE_FREE && 3039 zio->io_priority == ZIO_PRIORITY_NOW) { 3040 trim_map_free(vd, zio->io_offset, zio->io_size, zio->io_txg); 3041 return (ZIO_PIPELINE_CONTINUE); 3042 } 3043 3044 ASSERT3P(zio->io_logical, !=, zio); 3045 3046 /* 3047 * We keep track of time-sensitive I/Os so that the scan thread 3048 * can quickly react to certain workloads. In particular, we care 3049 * about non-scrubbing, top-level reads and writes with the following 3050 * characteristics: 3051 * - synchronous writes of user data to non-slog devices 3052 * - any reads of user data 3053 * When these conditions are met, adjust the timestamp of spa_last_io 3054 * which allows the scan thread to adjust its workload accordingly. 3055 */ 3056 if (!(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && zio->io_bp != NULL && 3057 vd == vd->vdev_top && !vd->vdev_islog && 3058 zio->io_bookmark.zb_objset != DMU_META_OBJSET && 3059 zio->io_txg != spa_syncing_txg(spa)) { 3060 uint64_t old = spa->spa_last_io; 3061 uint64_t new = ddi_get_lbolt64(); 3062 if (old != new) 3063 (void) atomic_cas_64(&spa->spa_last_io, old, new); 3064 } 3065 3066 align = 1ULL << vd->vdev_top->vdev_ashift; 3067 3068 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL) && 3069 P2PHASE(zio->io_size, align) != 0) { 3070 /* Transform logical writes to be a full physical block size. */ 3071 uint64_t asize = P2ROUNDUP(zio->io_size, align); 3072 char *abuf = NULL; 3073 if (zio->io_type == ZIO_TYPE_READ || 3074 zio->io_type == ZIO_TYPE_WRITE) 3075 abuf = zio_buf_alloc(asize); 3076 ASSERT(vd == vd->vdev_top); 3077 if (zio->io_type == ZIO_TYPE_WRITE) { 3078 bcopy(zio->io_data, abuf, zio->io_size); 3079 bzero(abuf + zio->io_size, asize - zio->io_size); 3080 } 3081 zio_push_transform(zio, abuf, asize, abuf ? asize : 0, 3082 zio_subblock); 3083 } 3084 3085 /* 3086 * If this is not a physical io, make sure that it is properly aligned 3087 * before proceeding. 3088 */ 3089 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL)) { 3090 ASSERT0(P2PHASE(zio->io_offset, align)); 3091 ASSERT0(P2PHASE(zio->io_size, align)); 3092 } else { 3093 /* 3094 * For the physical io we allow alignment 3095 * to a logical block size. 3096 */ 3097 uint64_t log_align = 3098 1ULL << vd->vdev_top->vdev_logical_ashift; 3099 ASSERT0(P2PHASE(zio->io_offset, log_align)); 3100 ASSERT0(P2PHASE(zio->io_size, log_align)); 3101 } 3102 3103 VERIFY(zio->io_type == ZIO_TYPE_READ || spa_writeable(spa)); 3104 3105 /* 3106 * If this is a repair I/O, and there's no self-healing involved -- 3107 * that is, we're just resilvering what we expect to resilver -- 3108 * then don't do the I/O unless zio's txg is actually in vd's DTL. 3109 * This prevents spurious resilvering with nested replication. 3110 * For example, given a mirror of mirrors, (A+B)+(C+D), if only 3111 * A is out of date, we'll read from C+D, then use the data to 3112 * resilver A+B -- but we don't actually want to resilver B, just A. 3113 * The top-level mirror has no way to know this, so instead we just 3114 * discard unnecessary repairs as we work our way down the vdev tree. 3115 * The same logic applies to any form of nested replication: 3116 * ditto + mirror, RAID-Z + replacing, etc. This covers them all. 3117 */ 3118 if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) && 3119 !(zio->io_flags & ZIO_FLAG_SELF_HEAL) && 3120 zio->io_txg != 0 && /* not a delegated i/o */ 3121 !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) { 3122 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 3123 zio_vdev_io_bypass(zio); 3124 return (ZIO_PIPELINE_CONTINUE); 3125 } 3126 3127 if (vd->vdev_ops->vdev_op_leaf) { 3128 switch (zio->io_type) { 3129 case ZIO_TYPE_READ: 3130 if (vdev_cache_read(zio)) 3131 return (ZIO_PIPELINE_CONTINUE); 3132 /* FALLTHROUGH */ 3133 case ZIO_TYPE_WRITE: 3134 case ZIO_TYPE_FREE: 3135 if ((zio = vdev_queue_io(zio)) == NULL) 3136 return (ZIO_PIPELINE_STOP); 3137 3138 if (!vdev_accessible(vd, zio)) { 3139 zio->io_error = SET_ERROR(ENXIO); 3140 zio_interrupt(zio); 3141 return (ZIO_PIPELINE_STOP); 3142 } 3143 break; 3144 } 3145 /* 3146 * Note that we ignore repair writes for TRIM because they can 3147 * conflict with normal writes. This isn't an issue because, by 3148 * definition, we only repair blocks that aren't freed. 3149 */ 3150 if (zio->io_type == ZIO_TYPE_WRITE && 3151 !(zio->io_flags & ZIO_FLAG_IO_REPAIR) && 3152 !trim_map_write_start(zio)) 3153 return (ZIO_PIPELINE_STOP); 3154 } 3155 3156 vd->vdev_ops->vdev_op_io_start(zio); 3157 return (ZIO_PIPELINE_STOP); 3158} 3159 3160static int 3161zio_vdev_io_done(zio_t *zio) 3162{ 3163 vdev_t *vd = zio->io_vd; 3164 vdev_ops_t *ops = vd ? vd->vdev_ops : &vdev_mirror_ops; 3165 boolean_t unexpected_error = B_FALSE; 3166 3167 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV_BIT, ZIO_WAIT_DONE)) { 3168 return (ZIO_PIPELINE_STOP); 3169 } 3170 3171 ASSERT(zio->io_type == ZIO_TYPE_READ || 3172 zio->io_type == ZIO_TYPE_WRITE || zio->io_type == ZIO_TYPE_FREE); 3173 3174 if (vd != NULL && vd->vdev_ops->vdev_op_leaf && 3175 (zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE || 3176 zio->io_type == ZIO_TYPE_FREE)) { 3177 3178 if (zio->io_type == ZIO_TYPE_WRITE && 3179 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) 3180 trim_map_write_done(zio); 3181 3182 vdev_queue_io_done(zio); 3183 3184 if (zio->io_type == ZIO_TYPE_WRITE) 3185 vdev_cache_write(zio); 3186 3187 if (zio_injection_enabled && zio->io_error == 0) 3188 zio->io_error = zio_handle_device_injection(vd, 3189 zio, EIO); 3190 3191 if (zio_injection_enabled && zio->io_error == 0) 3192 zio->io_error = zio_handle_label_injection(zio, EIO); 3193 3194 if (zio->io_error) { 3195 if (zio->io_error == ENOTSUP && 3196 zio->io_type == ZIO_TYPE_FREE) { 3197 /* Not all devices support TRIM. */ 3198 } else if (!vdev_accessible(vd, zio)) { 3199 zio->io_error = SET_ERROR(ENXIO); 3200 } else { 3201 unexpected_error = B_TRUE; 3202 } 3203 } 3204 } 3205 3206 ops->vdev_op_io_done(zio); 3207 3208 if (unexpected_error) 3209 VERIFY(vdev_probe(vd, zio) == NULL); 3210 3211 return (ZIO_PIPELINE_CONTINUE); 3212} 3213 3214/* 3215 * For non-raidz ZIOs, we can just copy aside the bad data read from the 3216 * disk, and use that to finish the checksum ereport later. 3217 */ 3218static void 3219zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr, 3220 const void *good_buf) 3221{ 3222 /* no processing needed */ 3223 zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE); 3224} 3225 3226/*ARGSUSED*/ 3227void 3228zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *ignored) 3229{ 3230 void *buf = zio_buf_alloc(zio->io_size); 3231 3232 bcopy(zio->io_data, buf, zio->io_size); 3233 3234 zcr->zcr_cbinfo = zio->io_size; 3235 zcr->zcr_cbdata = buf; 3236 zcr->zcr_finish = zio_vsd_default_cksum_finish; 3237 zcr->zcr_free = zio_buf_free; 3238} 3239 3240static int 3241zio_vdev_io_assess(zio_t *zio) 3242{ 3243 vdev_t *vd = zio->io_vd; 3244 3245 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV_BIT, ZIO_WAIT_DONE)) { 3246 return (ZIO_PIPELINE_STOP); 3247 } 3248 3249 if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 3250 spa_config_exit(zio->io_spa, SCL_ZIO, zio); 3251 3252 if (zio->io_vsd != NULL) { 3253 zio->io_vsd_ops->vsd_free(zio); 3254 zio->io_vsd = NULL; 3255 } 3256 3257 if (zio_injection_enabled && zio->io_error == 0) 3258 zio->io_error = zio_handle_fault_injection(zio, EIO); 3259 3260 if (zio->io_type == ZIO_TYPE_FREE && 3261 zio->io_priority != ZIO_PRIORITY_NOW) { 3262 switch (zio->io_error) { 3263 case 0: 3264 ZIO_TRIM_STAT_INCR(bytes, zio->io_size); 3265 ZIO_TRIM_STAT_BUMP(success); 3266 break; 3267 case EOPNOTSUPP: 3268 ZIO_TRIM_STAT_BUMP(unsupported); 3269 break; 3270 default: 3271 ZIO_TRIM_STAT_BUMP(failed); 3272 break; 3273 } 3274 } 3275 3276 /* 3277 * If the I/O failed, determine whether we should attempt to retry it. 3278 * 3279 * On retry, we cut in line in the issue queue, since we don't want 3280 * compression/checksumming/etc. work to prevent our (cheap) IO reissue. 3281 */ 3282 if (zio->io_error && vd == NULL && 3283 !(zio->io_flags & (ZIO_FLAG_DONT_RETRY | ZIO_FLAG_IO_RETRY))) { 3284 ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_QUEUE)); /* not a leaf */ 3285 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_BYPASS)); /* not a leaf */ 3286 zio->io_error = 0; 3287 zio->io_flags |= ZIO_FLAG_IO_RETRY | 3288 ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE; 3289 zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1; 3290 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, 3291 zio_requeue_io_start_cut_in_line); 3292 return (ZIO_PIPELINE_STOP); 3293 } 3294 3295 /* 3296 * If we got an error on a leaf device, convert it to ENXIO 3297 * if the device is not accessible at all. 3298 */ 3299 if (zio->io_error && vd != NULL && vd->vdev_ops->vdev_op_leaf && 3300 !vdev_accessible(vd, zio)) 3301 zio->io_error = SET_ERROR(ENXIO); 3302 3303 /* 3304 * If we can't write to an interior vdev (mirror or RAID-Z), 3305 * set vdev_cant_write so that we stop trying to allocate from it. 3306 */ 3307 if (zio->io_error == ENXIO && zio->io_type == ZIO_TYPE_WRITE && 3308 vd != NULL && !vd->vdev_ops->vdev_op_leaf) { 3309 vd->vdev_cant_write = B_TRUE; 3310 } 3311 3312 if (zio->io_error) 3313 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 3314 3315 if (vd != NULL && vd->vdev_ops->vdev_op_leaf && 3316 zio->io_physdone != NULL) { 3317 ASSERT(!(zio->io_flags & ZIO_FLAG_DELEGATED)); 3318 ASSERT(zio->io_child_type == ZIO_CHILD_VDEV); 3319 zio->io_physdone(zio->io_logical); 3320 } 3321 3322 return (ZIO_PIPELINE_CONTINUE); 3323} 3324 3325void 3326zio_vdev_io_reissue(zio_t *zio) 3327{ 3328 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 3329 ASSERT(zio->io_error == 0); 3330 3331 zio->io_stage >>= 1; 3332} 3333 3334void 3335zio_vdev_io_redone(zio_t *zio) 3336{ 3337 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE); 3338 3339 zio->io_stage >>= 1; 3340} 3341 3342void 3343zio_vdev_io_bypass(zio_t *zio) 3344{ 3345 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 3346 ASSERT(zio->io_error == 0); 3347 3348 zio->io_flags |= ZIO_FLAG_IO_BYPASS; 3349 zio->io_stage = ZIO_STAGE_VDEV_IO_ASSESS >> 1; 3350} 3351 3352/* 3353 * ========================================================================== 3354 * Generate and verify checksums 3355 * ========================================================================== 3356 */ 3357static int 3358zio_checksum_generate(zio_t *zio) 3359{ 3360 blkptr_t *bp = zio->io_bp; 3361 enum zio_checksum checksum; 3362 3363 if (bp == NULL) { 3364 /* 3365 * This is zio_write_phys(). 3366 * We're either generating a label checksum, or none at all. 3367 */ 3368 checksum = zio->io_prop.zp_checksum; 3369 3370 if (checksum == ZIO_CHECKSUM_OFF) 3371 return (ZIO_PIPELINE_CONTINUE); 3372 3373 ASSERT(checksum == ZIO_CHECKSUM_LABEL); 3374 } else { 3375 if (BP_IS_GANG(bp) && zio->io_child_type == ZIO_CHILD_GANG) { 3376 ASSERT(!IO_IS_ALLOCATING(zio)); 3377 checksum = ZIO_CHECKSUM_GANG_HEADER; 3378 } else { 3379 checksum = BP_GET_CHECKSUM(bp); 3380 } 3381 } 3382 3383 zio_checksum_compute(zio, checksum, zio->io_data, zio->io_size); 3384 3385 return (ZIO_PIPELINE_CONTINUE); 3386} 3387 3388static int 3389zio_checksum_verify(zio_t *zio) 3390{ 3391 zio_bad_cksum_t info; 3392 blkptr_t *bp = zio->io_bp; 3393 int error; 3394 3395 ASSERT(zio->io_vd != NULL); 3396 3397 if (bp == NULL) { 3398 /* 3399 * This is zio_read_phys(). 3400 * We're either verifying a label checksum, or nothing at all. 3401 */ 3402 if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF) 3403 return (ZIO_PIPELINE_CONTINUE); 3404 3405 ASSERT(zio->io_prop.zp_checksum == ZIO_CHECKSUM_LABEL); 3406 } 3407 3408 if ((error = zio_checksum_error(zio, &info)) != 0) { 3409 zio->io_error = error; 3410 if (error == ECKSUM && 3411 !(zio->io_flags & ZIO_FLAG_SPECULATIVE)) { 3412 zfs_ereport_start_checksum(zio->io_spa, 3413 zio->io_vd, zio, zio->io_offset, 3414 zio->io_size, NULL, &info); 3415 } 3416 } 3417 3418 return (ZIO_PIPELINE_CONTINUE); 3419} 3420 3421/* 3422 * Called by RAID-Z to ensure we don't compute the checksum twice. 3423 */ 3424void 3425zio_checksum_verified(zio_t *zio) 3426{ 3427 zio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 3428} 3429 3430/* 3431 * ========================================================================== 3432 * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other. 3433 * An error of 0 indicates success. ENXIO indicates whole-device failure, 3434 * which may be transient (e.g. unplugged) or permament. ECKSUM and EIO 3435 * indicate errors that are specific to one I/O, and most likely permanent. 3436 * Any other error is presumed to be worse because we weren't expecting it. 3437 * ========================================================================== 3438 */ 3439int 3440zio_worst_error(int e1, int e2) 3441{ 3442 static int zio_error_rank[] = { 0, ENXIO, ECKSUM, EIO }; 3443 int r1, r2; 3444 3445 for (r1 = 0; r1 < sizeof (zio_error_rank) / sizeof (int); r1++) 3446 if (e1 == zio_error_rank[r1]) 3447 break; 3448 3449 for (r2 = 0; r2 < sizeof (zio_error_rank) / sizeof (int); r2++) 3450 if (e2 == zio_error_rank[r2]) 3451 break; 3452 3453 return (r1 > r2 ? e1 : e2); 3454} 3455 3456/* 3457 * ========================================================================== 3458 * I/O completion 3459 * ========================================================================== 3460 */ 3461static int 3462zio_ready(zio_t *zio) 3463{ 3464 blkptr_t *bp = zio->io_bp; 3465 zio_t *pio, *pio_next; 3466 zio_link_t *zl = NULL; 3467 3468 if (zio_wait_for_children(zio, ZIO_CHILD_GANG_BIT | ZIO_CHILD_DDT_BIT, 3469 ZIO_WAIT_READY)) { 3470 return (ZIO_PIPELINE_STOP); 3471 } 3472 3473 if (zio->io_ready) { 3474 ASSERT(IO_IS_ALLOCATING(zio)); 3475 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp) || 3476 (zio->io_flags & ZIO_FLAG_NOPWRITE)); 3477 ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0); 3478 3479 zio->io_ready(zio); 3480 } 3481 3482 if (bp != NULL && bp != &zio->io_bp_copy) 3483 zio->io_bp_copy = *bp; 3484 3485 if (zio->io_error != 0) { 3486 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 3487 3488 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 3489 ASSERT(IO_IS_ALLOCATING(zio)); 3490 ASSERT(zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 3491 /* 3492 * We were unable to allocate anything, unreserve and 3493 * issue the next I/O to allocate. 3494 */ 3495 metaslab_class_throttle_unreserve( 3496 spa_normal_class(zio->io_spa), 3497 zio->io_prop.zp_copies, zio); 3498 zio_allocate_dispatch(zio->io_spa); 3499 } 3500 } 3501 3502 mutex_enter(&zio->io_lock); 3503 zio->io_state[ZIO_WAIT_READY] = 1; 3504 pio = zio_walk_parents(zio, &zl); 3505 mutex_exit(&zio->io_lock); 3506 3507 /* 3508 * As we notify zio's parents, new parents could be added. 3509 * New parents go to the head of zio's io_parent_list, however, 3510 * so we will (correctly) not notify them. The remainder of zio's 3511 * io_parent_list, from 'pio_next' onward, cannot change because 3512 * all parents must wait for us to be done before they can be done. 3513 */ 3514 for (; pio != NULL; pio = pio_next) { 3515 pio_next = zio_walk_parents(zio, &zl); 3516 zio_notify_parent(pio, zio, ZIO_WAIT_READY); 3517 } 3518 3519 if (zio->io_flags & ZIO_FLAG_NODATA) { 3520 if (BP_IS_GANG(bp)) { 3521 zio->io_flags &= ~ZIO_FLAG_NODATA; 3522 } else { 3523 ASSERT((uintptr_t)zio->io_data < SPA_MAXBLOCKSIZE); 3524 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 3525 } 3526 } 3527 3528 if (zio_injection_enabled && 3529 zio->io_spa->spa_syncing_txg == zio->io_txg) 3530 zio_handle_ignored_writes(zio); 3531 3532 return (ZIO_PIPELINE_CONTINUE); 3533} 3534 3535/* 3536 * Update the allocation throttle accounting. 3537 */ 3538static void 3539zio_dva_throttle_done(zio_t *zio) 3540{ 3541 zio_t *lio = zio->io_logical; 3542 zio_t *pio = zio_unique_parent(zio); 3543 vdev_t *vd = zio->io_vd; 3544 int flags = METASLAB_ASYNC_ALLOC; 3545 3546 ASSERT3P(zio->io_bp, !=, NULL); 3547 ASSERT3U(zio->io_type, ==, ZIO_TYPE_WRITE); 3548 ASSERT3U(zio->io_priority, ==, ZIO_PRIORITY_ASYNC_WRITE); 3549 ASSERT3U(zio->io_child_type, ==, ZIO_CHILD_VDEV); 3550 ASSERT(vd != NULL); 3551 ASSERT3P(vd, ==, vd->vdev_top); 3552 ASSERT(!(zio->io_flags & (ZIO_FLAG_IO_REPAIR | ZIO_FLAG_IO_RETRY))); 3553 ASSERT(zio->io_flags & ZIO_FLAG_IO_ALLOCATING); 3554 ASSERT(!(lio->io_flags & ZIO_FLAG_IO_REWRITE)); 3555 ASSERT(!(lio->io_orig_flags & ZIO_FLAG_NODATA)); 3556 3557 /* 3558 * Parents of gang children can have two flavors -- ones that 3559 * allocated the gang header (will have ZIO_FLAG_IO_REWRITE set) 3560 * and ones that allocated the constituent blocks. The allocation 3561 * throttle needs to know the allocating parent zio so we must find 3562 * it here. 3563 */ 3564 if (pio->io_child_type == ZIO_CHILD_GANG) { 3565 /* 3566 * If our parent is a rewrite gang child then our grandparent 3567 * would have been the one that performed the allocation. 3568 */ 3569 if (pio->io_flags & ZIO_FLAG_IO_REWRITE) 3570 pio = zio_unique_parent(pio); 3571 flags |= METASLAB_GANG_CHILD; 3572 } 3573 3574 ASSERT(IO_IS_ALLOCATING(pio)); 3575 ASSERT3P(zio, !=, zio->io_logical); 3576 ASSERT(zio->io_logical != NULL); 3577 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REPAIR)); 3578 ASSERT0(zio->io_flags & ZIO_FLAG_NOPWRITE); 3579 3580 mutex_enter(&pio->io_lock); 3581 metaslab_group_alloc_decrement(zio->io_spa, vd->vdev_id, pio, flags); 3582 mutex_exit(&pio->io_lock); 3583 3584 metaslab_class_throttle_unreserve(spa_normal_class(zio->io_spa), 3585 1, pio); 3586 3587 /* 3588 * Call into the pipeline to see if there is more work that 3589 * needs to be done. If there is work to be done it will be 3590 * dispatched to another taskq thread. 3591 */ 3592 zio_allocate_dispatch(zio->io_spa); 3593} 3594 3595static int 3596zio_done(zio_t *zio) 3597{ 3598 spa_t *spa = zio->io_spa; 3599 zio_t *lio = zio->io_logical; 3600 blkptr_t *bp = zio->io_bp; 3601 vdev_t *vd = zio->io_vd; 3602 uint64_t psize = zio->io_size; 3603 zio_t *pio, *pio_next; 3604 metaslab_class_t *mc = spa_normal_class(spa); 3605 zio_link_t *zl = NULL; 3606 3607 /* 3608 * If our children haven't all completed, 3609 * wait for them and then repeat this pipeline stage. 3610 */ 3611 if (zio_wait_for_children(zio, ZIO_CHILD_ALL_BITS, ZIO_WAIT_DONE)) { 3612 return (ZIO_PIPELINE_STOP); 3613 } 3614 3615 /* 3616 * If the allocation throttle is enabled, then update the accounting. 3617 * We only track child I/Os that are part of an allocating async 3618 * write. We must do this since the allocation is performed 3619 * by the logical I/O but the actual write is done by child I/Os. 3620 */ 3621 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING && 3622 zio->io_child_type == ZIO_CHILD_VDEV) { 3623 ASSERT(mc->mc_alloc_throttle_enabled); 3624 zio_dva_throttle_done(zio); 3625 } 3626 3627 /* 3628 * If the allocation throttle is enabled, verify that 3629 * we have decremented the refcounts for every I/O that was throttled. 3630 */ 3631 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 3632 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 3633 ASSERT(zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 3634 ASSERT(bp != NULL); 3635 metaslab_group_alloc_verify(spa, zio->io_bp, zio); 3636 VERIFY(refcount_not_held(&mc->mc_alloc_slots, zio)); 3637 } 3638 3639 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 3640 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 3641 ASSERT(zio->io_children[c][w] == 0); 3642 3643 if (bp != NULL && !BP_IS_EMBEDDED(bp)) { 3644 ASSERT(bp->blk_pad[0] == 0); 3645 ASSERT(bp->blk_pad[1] == 0); 3646 ASSERT(bcmp(bp, &zio->io_bp_copy, sizeof (blkptr_t)) == 0 || 3647 (bp == zio_unique_parent(zio)->io_bp)); 3648 if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(bp) && 3649 zio->io_bp_override == NULL && 3650 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) { 3651 ASSERT(!BP_SHOULD_BYTESWAP(bp)); 3652 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(bp)); 3653 ASSERT(BP_COUNT_GANG(bp) == 0 || 3654 (BP_COUNT_GANG(bp) == BP_GET_NDVAS(bp))); 3655 } 3656 if (zio->io_flags & ZIO_FLAG_NOPWRITE) 3657 VERIFY(BP_EQUAL(bp, &zio->io_bp_orig)); 3658 } 3659 3660 /* 3661 * If there were child vdev/gang/ddt errors, they apply to us now. 3662 */ 3663 zio_inherit_child_errors(zio, ZIO_CHILD_VDEV); 3664 zio_inherit_child_errors(zio, ZIO_CHILD_GANG); 3665 zio_inherit_child_errors(zio, ZIO_CHILD_DDT); 3666 3667 /* 3668 * If the I/O on the transformed data was successful, generate any 3669 * checksum reports now while we still have the transformed data. 3670 */ 3671 if (zio->io_error == 0) { 3672 while (zio->io_cksum_report != NULL) { 3673 zio_cksum_report_t *zcr = zio->io_cksum_report; 3674 uint64_t align = zcr->zcr_align; 3675 uint64_t asize = P2ROUNDUP(psize, align); 3676 char *abuf = zio->io_data; 3677 3678 if (asize != psize) { 3679 abuf = zio_buf_alloc(asize); 3680 bcopy(zio->io_data, abuf, psize); 3681 bzero(abuf + psize, asize - psize); 3682 } 3683 3684 zio->io_cksum_report = zcr->zcr_next; 3685 zcr->zcr_next = NULL; 3686 zcr->zcr_finish(zcr, abuf); 3687 zfs_ereport_free_checksum(zcr); 3688 3689 if (asize != psize) 3690 zio_buf_free(abuf, asize); 3691 } 3692 } 3693 3694 zio_pop_transforms(zio); /* note: may set zio->io_error */ 3695 3696 vdev_stat_update(zio, psize); 3697 3698 if (zio->io_error) { 3699 /* 3700 * If this I/O is attached to a particular vdev, 3701 * generate an error message describing the I/O failure 3702 * at the block level. We ignore these errors if the 3703 * device is currently unavailable. 3704 */ 3705 if (zio->io_error != ECKSUM && vd != NULL && !vdev_is_dead(vd)) 3706 zfs_ereport_post(FM_EREPORT_ZFS_IO, spa, vd, zio, 0, 0); 3707 3708 if ((zio->io_error == EIO || !(zio->io_flags & 3709 (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) && 3710 zio == lio) { 3711 /* 3712 * For logical I/O requests, tell the SPA to log the 3713 * error and generate a logical data ereport. 3714 */ 3715 spa_log_error(spa, zio); 3716 zfs_ereport_post(FM_EREPORT_ZFS_DATA, spa, NULL, zio, 3717 0, 0); 3718 } 3719 } 3720 3721 if (zio->io_error && zio == lio) { 3722 /* 3723 * Determine whether zio should be reexecuted. This will 3724 * propagate all the way to the root via zio_notify_parent(). 3725 */ 3726 ASSERT(vd == NULL && bp != NULL); 3727 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3728 3729 if (IO_IS_ALLOCATING(zio) && 3730 !(zio->io_flags & ZIO_FLAG_CANFAIL)) { 3731 if (zio->io_error != ENOSPC) 3732 zio->io_reexecute |= ZIO_REEXECUTE_NOW; 3733 else 3734 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3735 } 3736 3737 if ((zio->io_type == ZIO_TYPE_READ || 3738 zio->io_type == ZIO_TYPE_FREE) && 3739 !(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && 3740 zio->io_error == ENXIO && 3741 spa_load_state(spa) == SPA_LOAD_NONE && 3742 spa_get_failmode(spa) != ZIO_FAILURE_MODE_CONTINUE) 3743 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3744 3745 if (!(zio->io_flags & ZIO_FLAG_CANFAIL) && !zio->io_reexecute) 3746 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3747 3748 /* 3749 * Here is a possibly good place to attempt to do 3750 * either combinatorial reconstruction or error correction 3751 * based on checksums. It also might be a good place 3752 * to send out preliminary ereports before we suspend 3753 * processing. 3754 */ 3755 } 3756 3757 /* 3758 * If there were logical child errors, they apply to us now. 3759 * We defer this until now to avoid conflating logical child 3760 * errors with errors that happened to the zio itself when 3761 * updating vdev stats and reporting FMA events above. 3762 */ 3763 zio_inherit_child_errors(zio, ZIO_CHILD_LOGICAL); 3764 3765 if ((zio->io_error || zio->io_reexecute) && 3766 IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio && 3767 !(zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE))) 3768 zio_dva_unallocate(zio, zio->io_gang_tree, bp); 3769 3770 zio_gang_tree_free(&zio->io_gang_tree); 3771 3772 /* 3773 * Godfather I/Os should never suspend. 3774 */ 3775 if ((zio->io_flags & ZIO_FLAG_GODFATHER) && 3776 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) 3777 zio->io_reexecute = 0; 3778 3779 if (zio->io_reexecute) { 3780 /* 3781 * This is a logical I/O that wants to reexecute. 3782 * 3783 * Reexecute is top-down. When an i/o fails, if it's not 3784 * the root, it simply notifies its parent and sticks around. 3785 * The parent, seeing that it still has children in zio_done(), 3786 * does the same. This percolates all the way up to the root. 3787 * The root i/o will reexecute or suspend the entire tree. 3788 * 3789 * This approach ensures that zio_reexecute() honors 3790 * all the original i/o dependency relationships, e.g. 3791 * parents not executing until children are ready. 3792 */ 3793 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3794 3795 zio->io_gang_leader = NULL; 3796 3797 mutex_enter(&zio->io_lock); 3798 zio->io_state[ZIO_WAIT_DONE] = 1; 3799 mutex_exit(&zio->io_lock); 3800 3801 /* 3802 * "The Godfather" I/O monitors its children but is 3803 * not a true parent to them. It will track them through 3804 * the pipeline but severs its ties whenever they get into 3805 * trouble (e.g. suspended). This allows "The Godfather" 3806 * I/O to return status without blocking. 3807 */ 3808 zl = NULL; 3809 for (pio = zio_walk_parents(zio, &zl); pio != NULL; 3810 pio = pio_next) { 3811 zio_link_t *remove_zl = zl; 3812 pio_next = zio_walk_parents(zio, &zl); 3813 3814 if ((pio->io_flags & ZIO_FLAG_GODFATHER) && 3815 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) { 3816 zio_remove_child(pio, zio, remove_zl); 3817 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3818 } 3819 } 3820 3821 if ((pio = zio_unique_parent(zio)) != NULL) { 3822 /* 3823 * We're not a root i/o, so there's nothing to do 3824 * but notify our parent. Don't propagate errors 3825 * upward since we haven't permanently failed yet. 3826 */ 3827 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 3828 zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE; 3829 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3830 } else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) { 3831 /* 3832 * We'd fail again if we reexecuted now, so suspend 3833 * until conditions improve (e.g. device comes online). 3834 */ 3835 zio_suspend(spa, zio); 3836 } else { 3837 /* 3838 * Reexecution is potentially a huge amount of work. 3839 * Hand it off to the otherwise-unused claim taskq. 3840 */ 3841#if defined(illumos) || !defined(_KERNEL) 3842 ASSERT(zio->io_tqent.tqent_next == NULL); 3843#else 3844 ASSERT(zio->io_tqent.tqent_task.ta_pending == 0); 3845#endif 3846 spa_taskq_dispatch_ent(spa, ZIO_TYPE_CLAIM, 3847 ZIO_TASKQ_ISSUE, (task_func_t *)zio_reexecute, zio, 3848 0, &zio->io_tqent); 3849 } 3850 return (ZIO_PIPELINE_STOP); 3851 } 3852 3853 ASSERT(zio->io_child_count == 0); 3854 ASSERT(zio->io_reexecute == 0); 3855 ASSERT(zio->io_error == 0 || (zio->io_flags & ZIO_FLAG_CANFAIL)); 3856 3857 /* 3858 * Report any checksum errors, since the I/O is complete. 3859 */ 3860 while (zio->io_cksum_report != NULL) { 3861 zio_cksum_report_t *zcr = zio->io_cksum_report; 3862 zio->io_cksum_report = zcr->zcr_next; 3863 zcr->zcr_next = NULL; 3864 zcr->zcr_finish(zcr, NULL); 3865 zfs_ereport_free_checksum(zcr); 3866 } 3867 3868 /* 3869 * It is the responsibility of the done callback to ensure that this 3870 * particular zio is no longer discoverable for adoption, and as 3871 * such, cannot acquire any new parents. 3872 */ 3873 if (zio->io_done) 3874 zio->io_done(zio); 3875 3876 mutex_enter(&zio->io_lock); 3877 zio->io_state[ZIO_WAIT_DONE] = 1; 3878 mutex_exit(&zio->io_lock); 3879 3880 zl = NULL; 3881 for (pio = zio_walk_parents(zio, &zl); pio != NULL; pio = pio_next) { 3882 zio_link_t *remove_zl = zl; 3883 pio_next = zio_walk_parents(zio, &zl); 3884 zio_remove_child(pio, zio, remove_zl); 3885 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3886 } 3887 3888 if (zio->io_waiter != NULL) { 3889 mutex_enter(&zio->io_lock); 3890 zio->io_executor = NULL; 3891 cv_broadcast(&zio->io_cv); 3892 mutex_exit(&zio->io_lock); 3893 } else { 3894 zio_destroy(zio); 3895 } 3896 3897 return (ZIO_PIPELINE_STOP); 3898} 3899 3900/* 3901 * ========================================================================== 3902 * I/O pipeline definition 3903 * ========================================================================== 3904 */ 3905static zio_pipe_stage_t *zio_pipeline[] = { 3906 NULL, 3907 zio_read_bp_init, 3908 zio_write_bp_init, 3909 zio_free_bp_init, 3910 zio_issue_async, 3911 zio_write_compress, 3912 zio_checksum_generate, 3913 zio_nop_write, 3914 zio_ddt_read_start, 3915 zio_ddt_read_done, 3916 zio_ddt_write, 3917 zio_ddt_free, 3918 zio_gang_assemble, 3919 zio_gang_issue, 3920 zio_dva_throttle, 3921 zio_dva_allocate, 3922 zio_dva_free, 3923 zio_dva_claim, 3924 zio_ready, 3925 zio_vdev_io_start, 3926 zio_vdev_io_done, 3927 zio_vdev_io_assess, 3928 zio_checksum_verify, 3929 zio_done 3930}; 3931 3932 3933 3934 3935/* 3936 * Compare two zbookmark_phys_t's to see which we would reach first in a 3937 * pre-order traversal of the object tree. 3938 * 3939 * This is simple in every case aside from the meta-dnode object. For all other 3940 * objects, we traverse them in order (object 1 before object 2, and so on). 3941 * However, all of these objects are traversed while traversing object 0, since 3942 * the data it points to is the list of objects. Thus, we need to convert to a 3943 * canonical representation so we can compare meta-dnode bookmarks to 3944 * non-meta-dnode bookmarks. 3945 * 3946 * We do this by calculating "equivalents" for each field of the zbookmark. 3947 * zbookmarks outside of the meta-dnode use their own object and level, and 3948 * calculate the level 0 equivalent (the first L0 blkid that is contained in the 3949 * blocks this bookmark refers to) by multiplying their blkid by their span 3950 * (the number of L0 blocks contained within one block at their level). 3951 * zbookmarks inside the meta-dnode calculate their object equivalent 3952 * (which is L0equiv * dnodes per data block), use 0 for their L0equiv, and use 3953 * level + 1<<31 (any value larger than a level could ever be) for their level. 3954 * This causes them to always compare before a bookmark in their object 3955 * equivalent, compare appropriately to bookmarks in other objects, and to 3956 * compare appropriately to other bookmarks in the meta-dnode. 3957 */ 3958int 3959zbookmark_compare(uint16_t dbss1, uint8_t ibs1, uint16_t dbss2, uint8_t ibs2, 3960 const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2) 3961{ 3962 /* 3963 * These variables represent the "equivalent" values for the zbookmark, 3964 * after converting zbookmarks inside the meta dnode to their 3965 * normal-object equivalents. 3966 */ 3967 uint64_t zb1obj, zb2obj; 3968 uint64_t zb1L0, zb2L0; 3969 uint64_t zb1level, zb2level; 3970 3971 if (zb1->zb_object == zb2->zb_object && 3972 zb1->zb_level == zb2->zb_level && 3973 zb1->zb_blkid == zb2->zb_blkid) 3974 return (0); 3975 3976 /* 3977 * BP_SPANB calculates the span in blocks. 3978 */ 3979 zb1L0 = (zb1->zb_blkid) * BP_SPANB(ibs1, zb1->zb_level); 3980 zb2L0 = (zb2->zb_blkid) * BP_SPANB(ibs2, zb2->zb_level); 3981 3982 if (zb1->zb_object == DMU_META_DNODE_OBJECT) { 3983 zb1obj = zb1L0 * (dbss1 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT)); 3984 zb1L0 = 0; 3985 zb1level = zb1->zb_level + COMPARE_META_LEVEL; 3986 } else { 3987 zb1obj = zb1->zb_object; 3988 zb1level = zb1->zb_level; 3989 } 3990 3991 if (zb2->zb_object == DMU_META_DNODE_OBJECT) { 3992 zb2obj = zb2L0 * (dbss2 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT)); 3993 zb2L0 = 0; 3994 zb2level = zb2->zb_level + COMPARE_META_LEVEL; 3995 } else { 3996 zb2obj = zb2->zb_object; 3997 zb2level = zb2->zb_level; 3998 } 3999 4000 /* Now that we have a canonical representation, do the comparison. */ 4001 if (zb1obj != zb2obj) 4002 return (zb1obj < zb2obj ? -1 : 1); 4003 else if (zb1L0 != zb2L0) 4004 return (zb1L0 < zb2L0 ? -1 : 1); 4005 else if (zb1level != zb2level) 4006 return (zb1level > zb2level ? -1 : 1); 4007 /* 4008 * This can (theoretically) happen if the bookmarks have the same object 4009 * and level, but different blkids, if the block sizes are not the same. 4010 * There is presently no way to change the indirect block sizes 4011 */ 4012 return (0); 4013} 4014 4015/* 4016 * This function checks the following: given that last_block is the place that 4017 * our traversal stopped last time, does that guarantee that we've visited 4018 * every node under subtree_root? Therefore, we can't just use the raw output 4019 * of zbookmark_compare. We have to pass in a modified version of 4020 * subtree_root; by incrementing the block id, and then checking whether 4021 * last_block is before or equal to that, we can tell whether or not having 4022 * visited last_block implies that all of subtree_root's children have been 4023 * visited. 4024 */ 4025boolean_t 4026zbookmark_subtree_completed(const dnode_phys_t *dnp, 4027 const zbookmark_phys_t *subtree_root, const zbookmark_phys_t *last_block) 4028{ 4029 zbookmark_phys_t mod_zb = *subtree_root; 4030 mod_zb.zb_blkid++; 4031 ASSERT(last_block->zb_level == 0); 4032 4033 /* The objset_phys_t isn't before anything. */ 4034 if (dnp == NULL) 4035 return (B_FALSE); 4036 4037 /* 4038 * We pass in 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT) for the 4039 * data block size in sectors, because that variable is only used if 4040 * the bookmark refers to a block in the meta-dnode. Since we don't 4041 * know without examining it what object it refers to, and there's no 4042 * harm in passing in this value in other cases, we always pass it in. 4043 * 4044 * We pass in 0 for the indirect block size shift because zb2 must be 4045 * level 0. The indirect block size is only used to calculate the span 4046 * of the bookmark, but since the bookmark must be level 0, the span is 4047 * always 1, so the math works out. 4048 * 4049 * If you make changes to how the zbookmark_compare code works, be sure 4050 * to make sure that this code still works afterwards. 4051 */ 4052 return (zbookmark_compare(dnp->dn_datablkszsec, dnp->dn_indblkshift, 4053 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT), 0, &mod_zb, 4054 last_block) <= 0); 4055} 4056