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