1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2011, 2015 by Delphix. All rights reserved. 24 * Copyright (c) 2011 Nexenta Systems, Inc. All rights reserved. 25 */ 26 27 #include <sys/sysmacros.h> 28 #include <sys/zfs_context.h> 29 #include <sys/fm/fs/zfs.h> 30 #include <sys/spa.h> 31 #include <sys/txg.h> 32 #include <sys/spa_impl.h> 33 #include <sys/vdev_impl.h> 34 #include <sys/zio_impl.h> 35 #include <sys/zio_compress.h> 36 #include <sys/zio_checksum.h> 37 #include <sys/dmu_objset.h> 38 #include <sys/arc.h> 39 #include <sys/ddt.h> 40 #include <sys/blkptr.h> 41 #include <sys/zfeature.h> 42 43 /* 44 * ========================================================================== 45 * I/O type descriptions 46 * ========================================================================== 47 */ 48 const char *zio_type_name[ZIO_TYPES] = { 49 "zio_null", "zio_read", "zio_write", "zio_free", "zio_claim", 50 "zio_ioctl" 51 }; 52 53 /* 54 * ========================================================================== 55 * I/O kmem caches 56 * ========================================================================== 57 */ 58 kmem_cache_t *zio_cache; 59 kmem_cache_t *zio_link_cache; 60 kmem_cache_t *zio_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; 61 kmem_cache_t *zio_data_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; 62 63 #ifdef _KERNEL 64 extern vmem_t *zio_alloc_arena; 65 #endif 66 67 #define ZIO_PIPELINE_CONTINUE 0x100 68 #define ZIO_PIPELINE_STOP 0x101 69 70 #define BP_SPANB(indblkshift, level) \ 71 (((uint64_t)1) << ((level) * ((indblkshift) - SPA_BLKPTRSHIFT))) 72 #define COMPARE_META_LEVEL 0x80000000ul 73 /* 74 * The following actions directly effect the spa's sync-to-convergence logic. 75 * The values below define the sync pass when we start performing the action. 76 * Care should be taken when changing these values as they directly impact 77 * spa_sync() performance. Tuning these values may introduce subtle performance 78 * pathologies and should only be done in the context of performance analysis. 79 * These tunables will eventually be removed and replaced with #defines once 80 * enough analysis has been done to determine optimal values. 81 * 82 * The 'zfs_sync_pass_deferred_free' pass must be greater than 1 to ensure that 83 * regular blocks are not deferred. 84 */ 85 int zfs_sync_pass_deferred_free = 2; /* defer frees starting in this pass */ 86 int zfs_sync_pass_dont_compress = 5; /* don't compress starting in this pass */ 87 int zfs_sync_pass_rewrite = 2; /* rewrite new bps starting in this pass */ 88 89 /* 90 * An allocating zio is one that either currently has the DVA allocate 91 * stage set or will have it later in its lifetime. 92 */ 93 #define IO_IS_ALLOCATING(zio) ((zio)->io_orig_pipeline & ZIO_STAGE_DVA_ALLOCATE) 94 95 boolean_t zio_requeue_io_start_cut_in_line = B_TRUE; 96 97 #ifdef ZFS_DEBUG 98 int zio_buf_debug_limit = 16384; 99 #else 100 int zio_buf_debug_limit = 0; 101 #endif 102 103 void 104 zio_init(void) 105 { 106 size_t c; 107 vmem_t *data_alloc_arena = NULL; 108 109 #ifdef _KERNEL 110 data_alloc_arena = zio_alloc_arena; 111 #endif 112 zio_cache = kmem_cache_create("zio_cache", 113 sizeof (zio_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 114 zio_link_cache = kmem_cache_create("zio_link_cache", 115 sizeof (zio_link_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 116 117 /* 118 * For small buffers, we want a cache for each multiple of 119 * SPA_MINBLOCKSIZE. For larger buffers, we want a cache 120 * for each quarter-power of 2. 121 */ 122 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { 123 size_t size = (c + 1) << SPA_MINBLOCKSHIFT; 124 size_t p2 = size; 125 size_t align = 0; 126 size_t cflags = (size > zio_buf_debug_limit) ? KMC_NODEBUG : 0; 127 128 while (!ISP2(p2)) 129 p2 &= p2 - 1; 130 131 #ifndef _KERNEL 132 /* 133 * If we are using watchpoints, put each buffer on its own page, 134 * to eliminate the performance overhead of trapping to the 135 * kernel when modifying a non-watched buffer that shares the 136 * page with a watched buffer. 137 */ 138 if (arc_watch && !IS_P2ALIGNED(size, PAGESIZE)) 139 continue; 140 #endif 141 if (size <= 4 * SPA_MINBLOCKSIZE) { 142 align = SPA_MINBLOCKSIZE; 143 } else if (IS_P2ALIGNED(size, p2 >> 2)) { 144 align = MIN(p2 >> 2, PAGESIZE); 145 } 146 147 if (align != 0) { 148 char name[36]; 149 (void) sprintf(name, "zio_buf_%lu", (ulong_t)size); 150 zio_buf_cache[c] = kmem_cache_create(name, size, 151 align, NULL, NULL, NULL, NULL, NULL, cflags); 152 153 /* 154 * Since zio_data bufs do not appear in crash dumps, we 155 * pass KMC_NOTOUCH so that no allocator metadata is 156 * stored with the buffers. 157 */ 158 (void) sprintf(name, "zio_data_buf_%lu", (ulong_t)size); 159 zio_data_buf_cache[c] = kmem_cache_create(name, size, 160 align, NULL, NULL, NULL, NULL, data_alloc_arena, 161 cflags | KMC_NOTOUCH); 162 } 163 } 164 165 while (--c != 0) { 166 ASSERT(zio_buf_cache[c] != NULL); 167 if (zio_buf_cache[c - 1] == NULL) 168 zio_buf_cache[c - 1] = zio_buf_cache[c]; 169 170 ASSERT(zio_data_buf_cache[c] != NULL); 171 if (zio_data_buf_cache[c - 1] == NULL) 172 zio_data_buf_cache[c - 1] = zio_data_buf_cache[c]; 173 } 174 175 zio_inject_init(); 176 } 177 178 void 179 zio_fini(void) 180 { 181 size_t c; 182 kmem_cache_t *last_cache = NULL; 183 kmem_cache_t *last_data_cache = NULL; 184 185 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { 186 if (zio_buf_cache[c] != last_cache) { 187 last_cache = zio_buf_cache[c]; 188 kmem_cache_destroy(zio_buf_cache[c]); 189 } 190 zio_buf_cache[c] = NULL; 191 192 if (zio_data_buf_cache[c] != last_data_cache) { 193 last_data_cache = zio_data_buf_cache[c]; 194 kmem_cache_destroy(zio_data_buf_cache[c]); 195 } 196 zio_data_buf_cache[c] = NULL; 197 } 198 199 kmem_cache_destroy(zio_link_cache); 200 kmem_cache_destroy(zio_cache); 201 202 zio_inject_fini(); 203 } 204 205 /* 206 * ========================================================================== 207 * Allocate and free I/O buffers 208 * ========================================================================== 209 */ 210 211 /* 212 * Use zio_buf_alloc to allocate ZFS metadata. This data will appear in a 213 * crashdump if the kernel panics, so use it judiciously. Obviously, it's 214 * useful to inspect ZFS metadata, but if possible, we should avoid keeping 215 * excess / transient data in-core during a crashdump. 216 */ 217 void * 218 zio_buf_alloc(size_t size) 219 { 220 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 221 222 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 223 224 return (kmem_cache_alloc(zio_buf_cache[c], KM_PUSHPAGE)); 225 } 226 227 /* 228 * Use zio_data_buf_alloc to allocate data. The data will not appear in a 229 * crashdump if the kernel panics. This exists so that we will limit the amount 230 * of ZFS data that shows up in a kernel crashdump. (Thus reducing the amount 231 * of kernel heap dumped to disk when the kernel panics) 232 */ 233 void * 234 zio_data_buf_alloc(size_t size) 235 { 236 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 237 238 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 239 240 return (kmem_cache_alloc(zio_data_buf_cache[c], KM_PUSHPAGE)); 241 } 242 243 void 244 zio_buf_free(void *buf, size_t size) 245 { 246 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 247 248 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 249 250 kmem_cache_free(zio_buf_cache[c], buf); 251 } 252 253 void 254 zio_data_buf_free(void *buf, size_t size) 255 { 256 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 257 258 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 259 260 kmem_cache_free(zio_data_buf_cache[c], buf); 261 } 262 263 /* 264 * ========================================================================== 265 * Push and pop I/O transform buffers 266 * ========================================================================== 267 */ 268 static void 269 zio_push_transform(zio_t *zio, void *data, uint64_t size, uint64_t bufsize, 270 zio_transform_func_t *transform) 271 { 272 zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP); 273 274 zt->zt_orig_data = zio->io_data; 275 zt->zt_orig_size = zio->io_size; 276 zt->zt_bufsize = bufsize; 277 zt->zt_transform = transform; 278 279 zt->zt_next = zio->io_transform_stack; 280 zio->io_transform_stack = zt; 281 282 zio->io_data = data; 283 zio->io_size = size; 284 } 285 286 static void 287 zio_pop_transforms(zio_t *zio) 288 { 289 zio_transform_t *zt; 290 291 while ((zt = zio->io_transform_stack) != NULL) { 292 if (zt->zt_transform != NULL) 293 zt->zt_transform(zio, 294 zt->zt_orig_data, zt->zt_orig_size); 295 296 if (zt->zt_bufsize != 0) 297 zio_buf_free(zio->io_data, zt->zt_bufsize); 298 299 zio->io_data = zt->zt_orig_data; 300 zio->io_size = zt->zt_orig_size; 301 zio->io_transform_stack = zt->zt_next; 302 303 kmem_free(zt, sizeof (zio_transform_t)); 304 } 305 } 306 307 /* 308 * ========================================================================== 309 * I/O transform callbacks for subblocks and decompression 310 * ========================================================================== 311 */ 312 static void 313 zio_subblock(zio_t *zio, void *data, uint64_t size) 314 { 315 ASSERT(zio->io_size > size); 316 317 if (zio->io_type == ZIO_TYPE_READ) 318 bcopy(zio->io_data, data, size); 319 } 320 321 static void 322 zio_decompress(zio_t *zio, void *data, uint64_t size) 323 { 324 if (zio->io_error == 0 && 325 zio_decompress_data(BP_GET_COMPRESS(zio->io_bp), 326 zio->io_data, data, zio->io_size, size) != 0) 327 zio->io_error = SET_ERROR(EIO); 328 } 329 330 /* 331 * ========================================================================== 332 * I/O parent/child relationships and pipeline interlocks 333 * ========================================================================== 334 */ 335 /* 336 * NOTE - Callers to zio_walk_parents() and zio_walk_children must 337 * continue calling these functions until they return NULL. 338 * Otherwise, the next caller will pick up the list walk in 339 * some indeterminate state. (Otherwise every caller would 340 * have to pass in a cookie to keep the state represented by 341 * io_walk_link, which gets annoying.) 342 */ 343 zio_t * 344 zio_walk_parents(zio_t *cio) 345 { 346 zio_link_t *zl = cio->io_walk_link; 347 list_t *pl = &cio->io_parent_list; 348 349 zl = (zl == NULL) ? list_head(pl) : list_next(pl, zl); 350 cio->io_walk_link = zl; 351 352 if (zl == NULL) 353 return (NULL); 354 355 ASSERT(zl->zl_child == cio); 356 return (zl->zl_parent); 357 } 358 359 zio_t * 360 zio_walk_children(zio_t *pio) 361 { 362 zio_link_t *zl = pio->io_walk_link; 363 list_t *cl = &pio->io_child_list; 364 365 zl = (zl == NULL) ? list_head(cl) : list_next(cl, zl); 366 pio->io_walk_link = zl; 367 368 if (zl == NULL) 369 return (NULL); 370 371 ASSERT(zl->zl_parent == pio); 372 return (zl->zl_child); 373 } 374 375 zio_t * 376 zio_unique_parent(zio_t *cio) 377 { 378 zio_t *pio = zio_walk_parents(cio); 379 380 VERIFY(zio_walk_parents(cio) == NULL); 381 return (pio); 382 } 383 384 void 385 zio_add_child(zio_t *pio, zio_t *cio) 386 { 387 zio_link_t *zl = kmem_cache_alloc(zio_link_cache, KM_SLEEP); 388 389 /* 390 * Logical I/Os can have logical, gang, or vdev children. 391 * Gang I/Os can have gang or vdev children. 392 * Vdev I/Os can only have vdev children. 393 * The following ASSERT captures all of these constraints. 394 */ 395 ASSERT(cio->io_child_type <= pio->io_child_type); 396 397 zl->zl_parent = pio; 398 zl->zl_child = cio; 399 400 mutex_enter(&cio->io_lock); 401 mutex_enter(&pio->io_lock); 402 403 ASSERT(pio->io_state[ZIO_WAIT_DONE] == 0); 404 405 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 406 pio->io_children[cio->io_child_type][w] += !cio->io_state[w]; 407 408 list_insert_head(&pio->io_child_list, zl); 409 list_insert_head(&cio->io_parent_list, zl); 410 411 pio->io_child_count++; 412 cio->io_parent_count++; 413 414 mutex_exit(&pio->io_lock); 415 mutex_exit(&cio->io_lock); 416 } 417 418 static void 419 zio_remove_child(zio_t *pio, zio_t *cio, zio_link_t *zl) 420 { 421 ASSERT(zl->zl_parent == pio); 422 ASSERT(zl->zl_child == cio); 423 424 mutex_enter(&cio->io_lock); 425 mutex_enter(&pio->io_lock); 426 427 list_remove(&pio->io_child_list, zl); 428 list_remove(&cio->io_parent_list, zl); 429 430 pio->io_child_count--; 431 cio->io_parent_count--; 432 433 mutex_exit(&pio->io_lock); 434 mutex_exit(&cio->io_lock); 435 436 kmem_cache_free(zio_link_cache, zl); 437 } 438 439 static boolean_t 440 zio_wait_for_children(zio_t *zio, enum zio_child child, enum zio_wait_type wait) 441 { 442 uint64_t *countp = &zio->io_children[child][wait]; 443 boolean_t waiting = B_FALSE; 444 445 mutex_enter(&zio->io_lock); 446 ASSERT(zio->io_stall == NULL); 447 if (*countp != 0) { 448 zio->io_stage >>= 1; 449 zio->io_stall = countp; 450 waiting = B_TRUE; 451 } 452 mutex_exit(&zio->io_lock); 453 454 return (waiting); 455 } 456 457 static void 458 zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait) 459 { 460 uint64_t *countp = &pio->io_children[zio->io_child_type][wait]; 461 int *errorp = &pio->io_child_error[zio->io_child_type]; 462 463 mutex_enter(&pio->io_lock); 464 if (zio->io_error && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE)) 465 *errorp = zio_worst_error(*errorp, zio->io_error); 466 pio->io_reexecute |= zio->io_reexecute; 467 ASSERT3U(*countp, >, 0); 468 469 (*countp)--; 470 471 if (*countp == 0 && pio->io_stall == countp) { 472 pio->io_stall = NULL; 473 mutex_exit(&pio->io_lock); 474 zio_execute(pio); 475 } else { 476 mutex_exit(&pio->io_lock); 477 } 478 } 479 480 static void 481 zio_inherit_child_errors(zio_t *zio, enum zio_child c) 482 { 483 if (zio->io_child_error[c] != 0 && zio->io_error == 0) 484 zio->io_error = zio->io_child_error[c]; 485 } 486 487 /* 488 * ========================================================================== 489 * Create the various types of I/O (read, write, free, etc) 490 * ========================================================================== 491 */ 492 static zio_t * 493 zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 494 void *data, uint64_t size, zio_done_func_t *done, void *private, 495 zio_type_t type, zio_priority_t priority, enum zio_flag flags, 496 vdev_t *vd, uint64_t offset, const zbookmark_phys_t *zb, 497 enum zio_stage stage, enum zio_stage pipeline) 498 { 499 zio_t *zio; 500 501 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 502 ASSERT(P2PHASE(size, SPA_MINBLOCKSIZE) == 0); 503 ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0); 504 505 ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER)); 506 ASSERT(!bp || !(flags & ZIO_FLAG_CONFIG_WRITER)); 507 ASSERT(vd || stage == ZIO_STAGE_OPEN); 508 509 zio = kmem_cache_alloc(zio_cache, KM_SLEEP); 510 bzero(zio, sizeof (zio_t)); 511 512 mutex_init(&zio->io_lock, NULL, MUTEX_DEFAULT, NULL); 513 cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL); 514 515 list_create(&zio->io_parent_list, sizeof (zio_link_t), 516 offsetof(zio_link_t, zl_parent_node)); 517 list_create(&zio->io_child_list, sizeof (zio_link_t), 518 offsetof(zio_link_t, zl_child_node)); 519 520 if (vd != NULL) 521 zio->io_child_type = ZIO_CHILD_VDEV; 522 else if (flags & ZIO_FLAG_GANG_CHILD) 523 zio->io_child_type = ZIO_CHILD_GANG; 524 else if (flags & ZIO_FLAG_DDT_CHILD) 525 zio->io_child_type = ZIO_CHILD_DDT; 526 else 527 zio->io_child_type = ZIO_CHILD_LOGICAL; 528 529 if (bp != NULL) { 530 zio->io_bp = (blkptr_t *)bp; 531 zio->io_bp_copy = *bp; 532 zio->io_bp_orig = *bp; 533 if (type != ZIO_TYPE_WRITE || 534 zio->io_child_type == ZIO_CHILD_DDT) 535 zio->io_bp = &zio->io_bp_copy; /* so caller can free */ 536 if (zio->io_child_type == ZIO_CHILD_LOGICAL) 537 zio->io_logical = zio; 538 if (zio->io_child_type > ZIO_CHILD_GANG && BP_IS_GANG(bp)) 539 pipeline |= ZIO_GANG_STAGES; 540 } 541 542 zio->io_spa = spa; 543 zio->io_txg = txg; 544 zio->io_done = done; 545 zio->io_private = private; 546 zio->io_type = type; 547 zio->io_priority = priority; 548 zio->io_vd = vd; 549 zio->io_offset = offset; 550 zio->io_orig_data = zio->io_data = data; 551 zio->io_orig_size = zio->io_size = size; 552 zio->io_orig_flags = zio->io_flags = flags; 553 zio->io_orig_stage = zio->io_stage = stage; 554 zio->io_orig_pipeline = zio->io_pipeline = pipeline; 555 556 zio->io_state[ZIO_WAIT_READY] = (stage >= ZIO_STAGE_READY); 557 zio->io_state[ZIO_WAIT_DONE] = (stage >= ZIO_STAGE_DONE); 558 559 if (zb != NULL) 560 zio->io_bookmark = *zb; 561 562 if (pio != NULL) { 563 if (zio->io_logical == NULL) 564 zio->io_logical = pio->io_logical; 565 if (zio->io_child_type == ZIO_CHILD_GANG) 566 zio->io_gang_leader = pio->io_gang_leader; 567 zio_add_child(pio, zio); 568 } 569 570 return (zio); 571 } 572 573 static void 574 zio_destroy(zio_t *zio) 575 { 576 list_destroy(&zio->io_parent_list); 577 list_destroy(&zio->io_child_list); 578 mutex_destroy(&zio->io_lock); 579 cv_destroy(&zio->io_cv); 580 kmem_cache_free(zio_cache, zio); 581 } 582 583 zio_t * 584 zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, zio_done_func_t *done, 585 void *private, enum zio_flag flags) 586 { 587 zio_t *zio; 588 589 zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private, 590 ZIO_TYPE_NULL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL, 591 ZIO_STAGE_OPEN, ZIO_INTERLOCK_PIPELINE); 592 593 return (zio); 594 } 595 596 zio_t * 597 zio_root(spa_t *spa, zio_done_func_t *done, void *private, enum zio_flag flags) 598 { 599 return (zio_null(NULL, spa, NULL, done, private, flags)); 600 } 601 602 void 603 zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp) 604 { 605 if (!DMU_OT_IS_VALID(BP_GET_TYPE(bp))) { 606 zfs_panic_recover("blkptr at %p has invalid TYPE %llu", 607 bp, (longlong_t)BP_GET_TYPE(bp)); 608 } 609 if (BP_GET_CHECKSUM(bp) >= ZIO_CHECKSUM_FUNCTIONS || 610 BP_GET_CHECKSUM(bp) <= ZIO_CHECKSUM_ON) { 611 zfs_panic_recover("blkptr at %p has invalid CHECKSUM %llu", 612 bp, (longlong_t)BP_GET_CHECKSUM(bp)); 613 } 614 if (BP_GET_COMPRESS(bp) >= ZIO_COMPRESS_FUNCTIONS || 615 BP_GET_COMPRESS(bp) <= ZIO_COMPRESS_ON) { 616 zfs_panic_recover("blkptr at %p has invalid COMPRESS %llu", 617 bp, (longlong_t)BP_GET_COMPRESS(bp)); 618 } 619 if (BP_GET_LSIZE(bp) > SPA_MAXBLOCKSIZE) { 620 zfs_panic_recover("blkptr at %p has invalid LSIZE %llu", 621 bp, (longlong_t)BP_GET_LSIZE(bp)); 622 } 623 if (BP_GET_PSIZE(bp) > SPA_MAXBLOCKSIZE) { 624 zfs_panic_recover("blkptr at %p has invalid PSIZE %llu", 625 bp, (longlong_t)BP_GET_PSIZE(bp)); 626 } 627 628 if (BP_IS_EMBEDDED(bp)) { 629 if (BPE_GET_ETYPE(bp) > NUM_BP_EMBEDDED_TYPES) { 630 zfs_panic_recover("blkptr at %p has invalid ETYPE %llu", 631 bp, (longlong_t)BPE_GET_ETYPE(bp)); 632 } 633 } 634 635 /* 636 * Pool-specific checks. 637 * 638 * Note: it would be nice to verify that the blk_birth and 639 * BP_PHYSICAL_BIRTH() are not too large. However, spa_freeze() 640 * allows the birth time of log blocks (and dmu_sync()-ed blocks 641 * that are in the log) to be arbitrarily large. 642 */ 643 for (int i = 0; i < BP_GET_NDVAS(bp); i++) { 644 uint64_t vdevid = DVA_GET_VDEV(&bp->blk_dva[i]); 645 if (vdevid >= spa->spa_root_vdev->vdev_children) { 646 zfs_panic_recover("blkptr at %p DVA %u has invalid " 647 "VDEV %llu", 648 bp, i, (longlong_t)vdevid); 649 continue; 650 } 651 vdev_t *vd = spa->spa_root_vdev->vdev_child[vdevid]; 652 if (vd == NULL) { 653 zfs_panic_recover("blkptr at %p DVA %u has invalid " 654 "VDEV %llu", 655 bp, i, (longlong_t)vdevid); 656 continue; 657 } 658 if (vd->vdev_ops == &vdev_hole_ops) { 659 zfs_panic_recover("blkptr at %p DVA %u has hole " 660 "VDEV %llu", 661 bp, i, (longlong_t)vdevid); 662 continue; 663 } 664 if (vd->vdev_ops == &vdev_missing_ops) { 665 /* 666 * "missing" vdevs are valid during import, but we 667 * don't have their detailed info (e.g. asize), so 668 * we can't perform any more checks on them. 669 */ 670 continue; 671 } 672 uint64_t offset = DVA_GET_OFFSET(&bp->blk_dva[i]); 673 uint64_t asize = DVA_GET_ASIZE(&bp->blk_dva[i]); 674 if (BP_IS_GANG(bp)) 675 asize = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE); 676 if (offset + asize > vd->vdev_asize) { 677 zfs_panic_recover("blkptr at %p DVA %u has invalid " 678 "OFFSET %llu", 679 bp, i, (longlong_t)offset); 680 } 681 } 682 } 683 684 zio_t * 685 zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, 686 void *data, uint64_t size, zio_done_func_t *done, void *private, 687 zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb) 688 { 689 zio_t *zio; 690 691 zfs_blkptr_verify(spa, bp); 692 693 zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp, 694 data, size, done, private, 695 ZIO_TYPE_READ, priority, flags, NULL, 0, zb, 696 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 697 ZIO_DDT_CHILD_READ_PIPELINE : ZIO_READ_PIPELINE); 698 699 return (zio); 700 } 701 702 zio_t * 703 zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, 704 void *data, uint64_t size, const zio_prop_t *zp, 705 zio_done_func_t *ready, zio_done_func_t *physdone, zio_done_func_t *done, 706 void *private, 707 zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb) 708 { 709 zio_t *zio; 710 711 ASSERT(zp->zp_checksum >= ZIO_CHECKSUM_OFF && 712 zp->zp_checksum < ZIO_CHECKSUM_FUNCTIONS && 713 zp->zp_compress >= ZIO_COMPRESS_OFF && 714 zp->zp_compress < ZIO_COMPRESS_FUNCTIONS && 715 DMU_OT_IS_VALID(zp->zp_type) && 716 zp->zp_level < 32 && 717 zp->zp_copies > 0 && 718 zp->zp_copies <= spa_max_replication(spa)); 719 720 zio = zio_create(pio, spa, txg, bp, data, size, done, private, 721 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 722 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 723 ZIO_DDT_CHILD_WRITE_PIPELINE : ZIO_WRITE_PIPELINE); 724 725 zio->io_ready = ready; 726 zio->io_physdone = physdone; 727 zio->io_prop = *zp; 728 729 /* 730 * Data can be NULL if we are going to call zio_write_override() to 731 * provide the already-allocated BP. But we may need the data to 732 * verify a dedup hit (if requested). In this case, don't try to 733 * dedup (just take the already-allocated BP verbatim). 734 */ 735 if (data == NULL && zio->io_prop.zp_dedup_verify) { 736 zio->io_prop.zp_dedup = zio->io_prop.zp_dedup_verify = B_FALSE; 737 } 738 739 return (zio); 740 } 741 742 zio_t * 743 zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, void *data, 744 uint64_t size, zio_done_func_t *done, void *private, 745 zio_priority_t priority, enum zio_flag flags, zbookmark_phys_t *zb) 746 { 747 zio_t *zio; 748 749 zio = zio_create(pio, spa, txg, bp, data, size, done, private, 750 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 751 ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE); 752 753 return (zio); 754 } 755 756 void 757 zio_write_override(zio_t *zio, blkptr_t *bp, int copies, boolean_t nopwrite) 758 { 759 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 760 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 761 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 762 ASSERT(zio->io_txg == spa_syncing_txg(zio->io_spa)); 763 764 /* 765 * We must reset the io_prop to match the values that existed 766 * when the bp was first written by dmu_sync() keeping in mind 767 * that nopwrite and dedup are mutually exclusive. 768 */ 769 zio->io_prop.zp_dedup = nopwrite ? B_FALSE : zio->io_prop.zp_dedup; 770 zio->io_prop.zp_nopwrite = nopwrite; 771 zio->io_prop.zp_copies = copies; 772 zio->io_bp_override = bp; 773 } 774 775 void 776 zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp) 777 { 778 779 /* 780 * The check for EMBEDDED is a performance optimization. We 781 * process the free here (by ignoring it) rather than 782 * putting it on the list and then processing it in zio_free_sync(). 783 */ 784 if (BP_IS_EMBEDDED(bp)) 785 return; 786 metaslab_check_free(spa, bp); 787 788 /* 789 * Frees that are for the currently-syncing txg, are not going to be 790 * deferred, and which will not need to do a read (i.e. not GANG or 791 * DEDUP), can be processed immediately. Otherwise, put them on the 792 * in-memory list for later processing. 793 */ 794 if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp) || 795 txg != spa->spa_syncing_txg || 796 spa_sync_pass(spa) >= zfs_sync_pass_deferred_free) { 797 bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp); 798 } else { 799 VERIFY0(zio_wait(zio_free_sync(NULL, spa, txg, bp, 0))); 800 } 801 } 802 803 zio_t * 804 zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 805 enum zio_flag flags) 806 { 807 zio_t *zio; 808 enum zio_stage stage = ZIO_FREE_PIPELINE; 809 810 ASSERT(!BP_IS_HOLE(bp)); 811 ASSERT(spa_syncing_txg(spa) == txg); 812 ASSERT(spa_sync_pass(spa) < zfs_sync_pass_deferred_free); 813 814 if (BP_IS_EMBEDDED(bp)) 815 return (zio_null(pio, spa, NULL, NULL, NULL, 0)); 816 817 metaslab_check_free(spa, bp); 818 arc_freed(spa, bp); 819 820 /* 821 * GANG and DEDUP blocks can induce a read (for the gang block header, 822 * or the DDT), so issue them asynchronously so that this thread is 823 * not tied up. 824 */ 825 if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp)) 826 stage |= ZIO_STAGE_ISSUE_ASYNC; 827 828 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 829 NULL, NULL, ZIO_TYPE_FREE, ZIO_PRIORITY_NOW, flags, 830 NULL, 0, NULL, ZIO_STAGE_OPEN, stage); 831 832 return (zio); 833 } 834 835 zio_t * 836 zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 837 zio_done_func_t *done, void *private, enum zio_flag flags) 838 { 839 zio_t *zio; 840 841 dprintf_bp(bp, "claiming in txg %llu", txg); 842 843 if (BP_IS_EMBEDDED(bp)) 844 return (zio_null(pio, spa, NULL, NULL, NULL, 0)); 845 846 /* 847 * A claim is an allocation of a specific block. Claims are needed 848 * to support immediate writes in the intent log. The issue is that 849 * immediate writes contain committed data, but in a txg that was 850 * *not* committed. Upon opening the pool after an unclean shutdown, 851 * the intent log claims all blocks that contain immediate write data 852 * so that the SPA knows they're in use. 853 * 854 * All claims *must* be resolved in the first txg -- before the SPA 855 * starts allocating blocks -- so that nothing is allocated twice. 856 * If txg == 0 we just verify that the block is claimable. 857 */ 858 ASSERT3U(spa->spa_uberblock.ub_rootbp.blk_birth, <, spa_first_txg(spa)); 859 ASSERT(txg == spa_first_txg(spa) || txg == 0); 860 ASSERT(!BP_GET_DEDUP(bp) || !spa_writeable(spa)); /* zdb(1M) */ 861 862 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 863 done, private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW, flags, 864 NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE); 865 866 return (zio); 867 } 868 869 zio_t * 870 zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd, 871 zio_done_func_t *done, void *private, enum zio_flag flags) 872 { 873 zio_t *zio; 874 int c; 875 876 if (vd->vdev_children == 0) { 877 zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private, 878 ZIO_TYPE_IOCTL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL, 879 ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE); 880 881 zio->io_cmd = cmd; 882 } else { 883 zio = zio_null(pio, spa, NULL, NULL, NULL, flags); 884 885 for (c = 0; c < vd->vdev_children; c++) 886 zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd, 887 done, private, flags)); 888 } 889 890 return (zio); 891 } 892 893 zio_t * 894 zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 895 void *data, int checksum, zio_done_func_t *done, void *private, 896 zio_priority_t priority, enum zio_flag flags, boolean_t labels) 897 { 898 zio_t *zio; 899 900 ASSERT(vd->vdev_children == 0); 901 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 902 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 903 ASSERT3U(offset + size, <=, vd->vdev_psize); 904 905 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private, 906 ZIO_TYPE_READ, priority, flags | ZIO_FLAG_PHYSICAL, vd, offset, 907 NULL, ZIO_STAGE_OPEN, ZIO_READ_PHYS_PIPELINE); 908 909 zio->io_prop.zp_checksum = checksum; 910 911 return (zio); 912 } 913 914 zio_t * 915 zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 916 void *data, int checksum, zio_done_func_t *done, void *private, 917 zio_priority_t priority, enum zio_flag flags, boolean_t labels) 918 { 919 zio_t *zio; 920 921 ASSERT(vd->vdev_children == 0); 922 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 923 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 924 ASSERT3U(offset + size, <=, vd->vdev_psize); 925 926 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private, 927 ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_PHYSICAL, vd, offset, 928 NULL, ZIO_STAGE_OPEN, ZIO_WRITE_PHYS_PIPELINE); 929 930 zio->io_prop.zp_checksum = checksum; 931 932 if (zio_checksum_table[checksum].ci_eck) { 933 /* 934 * zec checksums are necessarily destructive -- they modify 935 * the end of the write buffer to hold the verifier/checksum. 936 * Therefore, we must make a local copy in case the data is 937 * being written to multiple places in parallel. 938 */ 939 void *wbuf = zio_buf_alloc(size); 940 bcopy(data, wbuf, size); 941 zio_push_transform(zio, wbuf, size, size, NULL); 942 } 943 944 return (zio); 945 } 946 947 /* 948 * Create a child I/O to do some work for us. 949 */ 950 zio_t * 951 zio_vdev_child_io(zio_t *pio, blkptr_t *bp, vdev_t *vd, uint64_t offset, 952 void *data, uint64_t size, int type, zio_priority_t priority, 953 enum zio_flag flags, zio_done_func_t *done, void *private) 954 { 955 enum zio_stage pipeline = ZIO_VDEV_CHILD_PIPELINE; 956 zio_t *zio; 957 958 ASSERT(vd->vdev_parent == 959 (pio->io_vd ? pio->io_vd : pio->io_spa->spa_root_vdev)); 960 961 if (type == ZIO_TYPE_READ && bp != NULL) { 962 /* 963 * If we have the bp, then the child should perform the 964 * checksum and the parent need not. This pushes error 965 * detection as close to the leaves as possible and 966 * eliminates redundant checksums in the interior nodes. 967 */ 968 pipeline |= ZIO_STAGE_CHECKSUM_VERIFY; 969 pio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 970 } 971 972 if (vd->vdev_children == 0) 973 offset += VDEV_LABEL_START_SIZE; 974 975 flags |= ZIO_VDEV_CHILD_FLAGS(pio) | ZIO_FLAG_DONT_PROPAGATE; 976 977 /* 978 * If we've decided to do a repair, the write is not speculative -- 979 * even if the original read was. 980 */ 981 if (flags & ZIO_FLAG_IO_REPAIR) 982 flags &= ~ZIO_FLAG_SPECULATIVE; 983 984 zio = zio_create(pio, pio->io_spa, pio->io_txg, bp, data, size, 985 done, private, type, priority, flags, vd, offset, &pio->io_bookmark, 986 ZIO_STAGE_VDEV_IO_START >> 1, pipeline); 987 988 zio->io_physdone = pio->io_physdone; 989 if (vd->vdev_ops->vdev_op_leaf && zio->io_logical != NULL) 990 zio->io_logical->io_phys_children++; 991 992 return (zio); 993 } 994 995 zio_t * 996 zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, void *data, uint64_t size, 997 int type, zio_priority_t priority, enum zio_flag flags, 998 zio_done_func_t *done, void *private) 999 { 1000 zio_t *zio; 1001 1002 ASSERT(vd->vdev_ops->vdev_op_leaf); 1003 1004 zio = zio_create(NULL, vd->vdev_spa, 0, NULL, 1005 data, size, done, private, type, priority, 1006 flags | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY | ZIO_FLAG_DELEGATED, 1007 vd, offset, NULL, 1008 ZIO_STAGE_VDEV_IO_START >> 1, ZIO_VDEV_CHILD_PIPELINE); 1009 1010 return (zio); 1011 } 1012 1013 void 1014 zio_flush(zio_t *zio, vdev_t *vd) 1015 { 1016 zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE, 1017 NULL, NULL, 1018 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY)); 1019 } 1020 1021 void 1022 zio_shrink(zio_t *zio, uint64_t size) 1023 { 1024 ASSERT(zio->io_executor == NULL); 1025 ASSERT(zio->io_orig_size == zio->io_size); 1026 ASSERT(size <= zio->io_size); 1027 1028 /* 1029 * We don't shrink for raidz because of problems with the 1030 * reconstruction when reading back less than the block size. 1031 * Note, BP_IS_RAIDZ() assumes no compression. 1032 */ 1033 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 1034 if (!BP_IS_RAIDZ(zio->io_bp)) 1035 zio->io_orig_size = zio->io_size = size; 1036 } 1037 1038 /* 1039 * ========================================================================== 1040 * Prepare to read and write logical blocks 1041 * ========================================================================== 1042 */ 1043 1044 static int 1045 zio_read_bp_init(zio_t *zio) 1046 { 1047 blkptr_t *bp = zio->io_bp; 1048 1049 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF && 1050 zio->io_child_type == ZIO_CHILD_LOGICAL && 1051 !(zio->io_flags & ZIO_FLAG_RAW)) { 1052 uint64_t psize = 1053 BP_IS_EMBEDDED(bp) ? BPE_GET_PSIZE(bp) : BP_GET_PSIZE(bp); 1054 void *cbuf = zio_buf_alloc(psize); 1055 1056 zio_push_transform(zio, cbuf, psize, psize, zio_decompress); 1057 } 1058 1059 if (BP_IS_EMBEDDED(bp) && BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA) { 1060 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1061 decode_embedded_bp_compressed(bp, zio->io_data); 1062 } else { 1063 ASSERT(!BP_IS_EMBEDDED(bp)); 1064 } 1065 1066 if (!DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) && BP_GET_LEVEL(bp) == 0) 1067 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 1068 1069 if (BP_GET_TYPE(bp) == DMU_OT_DDT_ZAP) 1070 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 1071 1072 if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL) 1073 zio->io_pipeline = ZIO_DDT_READ_PIPELINE; 1074 1075 return (ZIO_PIPELINE_CONTINUE); 1076 } 1077 1078 static int 1079 zio_write_bp_init(zio_t *zio) 1080 { 1081 spa_t *spa = zio->io_spa; 1082 zio_prop_t *zp = &zio->io_prop; 1083 enum zio_compress compress = zp->zp_compress; 1084 blkptr_t *bp = zio->io_bp; 1085 uint64_t lsize = zio->io_size; 1086 uint64_t psize = lsize; 1087 int pass = 1; 1088 1089 /* 1090 * If our children haven't all reached the ready stage, 1091 * wait for them and then repeat this pipeline stage. 1092 */ 1093 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 1094 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_READY)) 1095 return (ZIO_PIPELINE_STOP); 1096 1097 if (!IO_IS_ALLOCATING(zio)) 1098 return (ZIO_PIPELINE_CONTINUE); 1099 1100 ASSERT(zio->io_child_type != ZIO_CHILD_DDT); 1101 1102 if (zio->io_bp_override) { 1103 ASSERT(bp->blk_birth != zio->io_txg); 1104 ASSERT(BP_GET_DEDUP(zio->io_bp_override) == 0); 1105 1106 *bp = *zio->io_bp_override; 1107 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1108 1109 if (BP_IS_EMBEDDED(bp)) 1110 return (ZIO_PIPELINE_CONTINUE); 1111 1112 /* 1113 * If we've been overridden and nopwrite is set then 1114 * set the flag accordingly to indicate that a nopwrite 1115 * has already occurred. 1116 */ 1117 if (!BP_IS_HOLE(bp) && zp->zp_nopwrite) { 1118 ASSERT(!zp->zp_dedup); 1119 zio->io_flags |= ZIO_FLAG_NOPWRITE; 1120 return (ZIO_PIPELINE_CONTINUE); 1121 } 1122 1123 ASSERT(!zp->zp_nopwrite); 1124 1125 if (BP_IS_HOLE(bp) || !zp->zp_dedup) 1126 return (ZIO_PIPELINE_CONTINUE); 1127 1128 ASSERT(zio_checksum_table[zp->zp_checksum].ci_dedup || 1129 zp->zp_dedup_verify); 1130 1131 if (BP_GET_CHECKSUM(bp) == zp->zp_checksum) { 1132 BP_SET_DEDUP(bp, 1); 1133 zio->io_pipeline |= ZIO_STAGE_DDT_WRITE; 1134 return (ZIO_PIPELINE_CONTINUE); 1135 } 1136 } 1137 1138 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg) { 1139 /* 1140 * We're rewriting an existing block, which means we're 1141 * working on behalf of spa_sync(). For spa_sync() to 1142 * converge, it must eventually be the case that we don't 1143 * have to allocate new blocks. But compression changes 1144 * the blocksize, which forces a reallocate, and makes 1145 * convergence take longer. Therefore, after the first 1146 * few passes, stop compressing to ensure convergence. 1147 */ 1148 pass = spa_sync_pass(spa); 1149 1150 ASSERT(zio->io_txg == spa_syncing_txg(spa)); 1151 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1152 ASSERT(!BP_GET_DEDUP(bp)); 1153 1154 if (pass >= zfs_sync_pass_dont_compress) 1155 compress = ZIO_COMPRESS_OFF; 1156 1157 /* Make sure someone doesn't change their mind on overwrites */ 1158 ASSERT(BP_IS_EMBEDDED(bp) || MIN(zp->zp_copies + BP_IS_GANG(bp), 1159 spa_max_replication(spa)) == BP_GET_NDVAS(bp)); 1160 } 1161 1162 if (compress != ZIO_COMPRESS_OFF) { 1163 void *cbuf = zio_buf_alloc(lsize); 1164 psize = zio_compress_data(compress, zio->io_data, cbuf, lsize); 1165 if (psize == 0 || psize == lsize) { 1166 compress = ZIO_COMPRESS_OFF; 1167 zio_buf_free(cbuf, lsize); 1168 } else if (!zp->zp_dedup && psize <= BPE_PAYLOAD_SIZE && 1169 zp->zp_level == 0 && !DMU_OT_HAS_FILL(zp->zp_type) && 1170 spa_feature_is_enabled(spa, SPA_FEATURE_EMBEDDED_DATA)) { 1171 encode_embedded_bp_compressed(bp, 1172 cbuf, compress, lsize, psize); 1173 BPE_SET_ETYPE(bp, BP_EMBEDDED_TYPE_DATA); 1174 BP_SET_TYPE(bp, zio->io_prop.zp_type); 1175 BP_SET_LEVEL(bp, zio->io_prop.zp_level); 1176 zio_buf_free(cbuf, lsize); 1177 bp->blk_birth = zio->io_txg; 1178 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1179 ASSERT(spa_feature_is_active(spa, 1180 SPA_FEATURE_EMBEDDED_DATA)); 1181 return (ZIO_PIPELINE_CONTINUE); 1182 } else { 1183 /* 1184 * Round up compressed size up to the ashift 1185 * of the smallest-ashift device, and zero the tail. 1186 * This ensures that the compressed size of the BP 1187 * (and thus compressratio property) are correct, 1188 * in that we charge for the padding used to fill out 1189 * the last sector. 1190 */ 1191 ASSERT3U(spa->spa_min_ashift, >=, SPA_MINBLOCKSHIFT); 1192 size_t rounded = (size_t)P2ROUNDUP(psize, 1193 1ULL << spa->spa_min_ashift); 1194 if (rounded >= lsize) { 1195 compress = ZIO_COMPRESS_OFF; 1196 zio_buf_free(cbuf, lsize); 1197 psize = lsize; 1198 } else { 1199 bzero((char *)cbuf + psize, rounded - psize); 1200 psize = rounded; 1201 zio_push_transform(zio, cbuf, 1202 psize, lsize, NULL); 1203 } 1204 } 1205 } 1206 1207 /* 1208 * The final pass of spa_sync() must be all rewrites, but the first 1209 * few passes offer a trade-off: allocating blocks defers convergence, 1210 * but newly allocated blocks are sequential, so they can be written 1211 * to disk faster. Therefore, we allow the first few passes of 1212 * spa_sync() to allocate new blocks, but force rewrites after that. 1213 * There should only be a handful of blocks after pass 1 in any case. 1214 */ 1215 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg && 1216 BP_GET_PSIZE(bp) == psize && 1217 pass >= zfs_sync_pass_rewrite) { 1218 ASSERT(psize != 0); 1219 enum zio_stage gang_stages = zio->io_pipeline & ZIO_GANG_STAGES; 1220 zio->io_pipeline = ZIO_REWRITE_PIPELINE | gang_stages; 1221 zio->io_flags |= ZIO_FLAG_IO_REWRITE; 1222 } else { 1223 BP_ZERO(bp); 1224 zio->io_pipeline = ZIO_WRITE_PIPELINE; 1225 } 1226 1227 if (psize == 0) { 1228 if (zio->io_bp_orig.blk_birth != 0 && 1229 spa_feature_is_active(spa, SPA_FEATURE_HOLE_BIRTH)) { 1230 BP_SET_LSIZE(bp, lsize); 1231 BP_SET_TYPE(bp, zp->zp_type); 1232 BP_SET_LEVEL(bp, zp->zp_level); 1233 BP_SET_BIRTH(bp, zio->io_txg, 0); 1234 } 1235 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1236 } else { 1237 ASSERT(zp->zp_checksum != ZIO_CHECKSUM_GANG_HEADER); 1238 BP_SET_LSIZE(bp, lsize); 1239 BP_SET_TYPE(bp, zp->zp_type); 1240 BP_SET_LEVEL(bp, zp->zp_level); 1241 BP_SET_PSIZE(bp, psize); 1242 BP_SET_COMPRESS(bp, compress); 1243 BP_SET_CHECKSUM(bp, zp->zp_checksum); 1244 BP_SET_DEDUP(bp, zp->zp_dedup); 1245 BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER); 1246 if (zp->zp_dedup) { 1247 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1248 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1249 zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE; 1250 } 1251 if (zp->zp_nopwrite) { 1252 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1253 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1254 zio->io_pipeline |= ZIO_STAGE_NOP_WRITE; 1255 } 1256 } 1257 1258 return (ZIO_PIPELINE_CONTINUE); 1259 } 1260 1261 static int 1262 zio_free_bp_init(zio_t *zio) 1263 { 1264 blkptr_t *bp = zio->io_bp; 1265 1266 if (zio->io_child_type == ZIO_CHILD_LOGICAL) { 1267 if (BP_GET_DEDUP(bp)) 1268 zio->io_pipeline = ZIO_DDT_FREE_PIPELINE; 1269 } 1270 1271 return (ZIO_PIPELINE_CONTINUE); 1272 } 1273 1274 /* 1275 * ========================================================================== 1276 * Execute the I/O pipeline 1277 * ========================================================================== 1278 */ 1279 1280 static void 1281 zio_taskq_dispatch(zio_t *zio, zio_taskq_type_t q, boolean_t cutinline) 1282 { 1283 spa_t *spa = zio->io_spa; 1284 zio_type_t t = zio->io_type; 1285 int flags = (cutinline ? TQ_FRONT : 0); 1286 1287 /* 1288 * If we're a config writer or a probe, the normal issue and 1289 * interrupt threads may all be blocked waiting for the config lock. 1290 * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL. 1291 */ 1292 if (zio->io_flags & (ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_PROBE)) 1293 t = ZIO_TYPE_NULL; 1294 1295 /* 1296 * A similar issue exists for the L2ARC write thread until L2ARC 2.0. 1297 */ 1298 if (t == ZIO_TYPE_WRITE && zio->io_vd && zio->io_vd->vdev_aux) 1299 t = ZIO_TYPE_NULL; 1300 1301 /* 1302 * If this is a high priority I/O, then use the high priority taskq if 1303 * available. 1304 */ 1305 if (zio->io_priority == ZIO_PRIORITY_NOW && 1306 spa->spa_zio_taskq[t][q + 1].stqs_count != 0) 1307 q++; 1308 1309 ASSERT3U(q, <, ZIO_TASKQ_TYPES); 1310 1311 /* 1312 * NB: We are assuming that the zio can only be dispatched 1313 * to a single taskq at a time. It would be a grievous error 1314 * to dispatch the zio to another taskq at the same time. 1315 */ 1316 ASSERT(zio->io_tqent.tqent_next == NULL); 1317 spa_taskq_dispatch_ent(spa, t, q, (task_func_t *)zio_execute, zio, 1318 flags, &zio->io_tqent); 1319 } 1320 1321 static boolean_t 1322 zio_taskq_member(zio_t *zio, zio_taskq_type_t q) 1323 { 1324 kthread_t *executor = zio->io_executor; 1325 spa_t *spa = zio->io_spa; 1326 1327 for (zio_type_t t = 0; t < ZIO_TYPES; t++) { 1328 spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q]; 1329 uint_t i; 1330 for (i = 0; i < tqs->stqs_count; i++) { 1331 if (taskq_member(tqs->stqs_taskq[i], executor)) 1332 return (B_TRUE); 1333 } 1334 } 1335 1336 return (B_FALSE); 1337 } 1338 1339 static int 1340 zio_issue_async(zio_t *zio) 1341 { 1342 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 1343 1344 return (ZIO_PIPELINE_STOP); 1345 } 1346 1347 void 1348 zio_interrupt(zio_t *zio) 1349 { 1350 zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE); 1351 } 1352 1353 /* 1354 * Execute the I/O pipeline until one of the following occurs: 1355 * 1356 * (1) the I/O completes 1357 * (2) the pipeline stalls waiting for dependent child I/Os 1358 * (3) the I/O issues, so we're waiting for an I/O completion interrupt 1359 * (4) the I/O is delegated by vdev-level caching or aggregation 1360 * (5) the I/O is deferred due to vdev-level queueing 1361 * (6) the I/O is handed off to another thread. 1362 * 1363 * In all cases, the pipeline stops whenever there's no CPU work; it never 1364 * burns a thread in cv_wait(). 1365 * 1366 * There's no locking on io_stage because there's no legitimate way 1367 * for multiple threads to be attempting to process the same I/O. 1368 */ 1369 static zio_pipe_stage_t *zio_pipeline[]; 1370 1371 void 1372 zio_execute(zio_t *zio) 1373 { 1374 zio->io_executor = curthread; 1375 1376 while (zio->io_stage < ZIO_STAGE_DONE) { 1377 enum zio_stage pipeline = zio->io_pipeline; 1378 enum zio_stage stage = zio->io_stage; 1379 int rv; 1380 1381 ASSERT(!MUTEX_HELD(&zio->io_lock)); 1382 ASSERT(ISP2(stage)); 1383 ASSERT(zio->io_stall == NULL); 1384 1385 do { 1386 stage <<= 1; 1387 } while ((stage & pipeline) == 0); 1388 1389 ASSERT(stage <= ZIO_STAGE_DONE); 1390 1391 /* 1392 * If we are in interrupt context and this pipeline stage 1393 * will grab a config lock that is held across I/O, 1394 * or may wait for an I/O that needs an interrupt thread 1395 * to complete, issue async to avoid deadlock. 1396 * 1397 * For VDEV_IO_START, we cut in line so that the io will 1398 * be sent to disk promptly. 1399 */ 1400 if ((stage & ZIO_BLOCKING_STAGES) && zio->io_vd == NULL && 1401 zio_taskq_member(zio, ZIO_TASKQ_INTERRUPT)) { 1402 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ? 1403 zio_requeue_io_start_cut_in_line : B_FALSE; 1404 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut); 1405 return; 1406 } 1407 1408 zio->io_stage = stage; 1409 rv = zio_pipeline[highbit64(stage) - 1](zio); 1410 1411 if (rv == ZIO_PIPELINE_STOP) 1412 return; 1413 1414 ASSERT(rv == ZIO_PIPELINE_CONTINUE); 1415 } 1416 } 1417 1418 /* 1419 * ========================================================================== 1420 * Initiate I/O, either sync or async 1421 * ========================================================================== 1422 */ 1423 int 1424 zio_wait(zio_t *zio) 1425 { 1426 int error; 1427 1428 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 1429 ASSERT(zio->io_executor == NULL); 1430 1431 zio->io_waiter = curthread; 1432 1433 zio_execute(zio); 1434 1435 mutex_enter(&zio->io_lock); 1436 while (zio->io_executor != NULL) 1437 cv_wait(&zio->io_cv, &zio->io_lock); 1438 mutex_exit(&zio->io_lock); 1439 1440 error = zio->io_error; 1441 zio_destroy(zio); 1442 1443 return (error); 1444 } 1445 1446 void 1447 zio_nowait(zio_t *zio) 1448 { 1449 ASSERT(zio->io_executor == NULL); 1450 1451 if (zio->io_child_type == ZIO_CHILD_LOGICAL && 1452 zio_unique_parent(zio) == NULL) { 1453 /* 1454 * This is a logical async I/O with no parent to wait for it. 1455 * We add it to the spa_async_root_zio "Godfather" I/O which 1456 * will ensure they complete prior to unloading the pool. 1457 */ 1458 spa_t *spa = zio->io_spa; 1459 1460 zio_add_child(spa->spa_async_zio_root[CPU_SEQID], zio); 1461 } 1462 1463 zio_execute(zio); 1464 } 1465 1466 /* 1467 * ========================================================================== 1468 * Reexecute or suspend/resume failed I/O 1469 * ========================================================================== 1470 */ 1471 1472 static void 1473 zio_reexecute(zio_t *pio) 1474 { 1475 zio_t *cio, *cio_next; 1476 1477 ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL); 1478 ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN); 1479 ASSERT(pio->io_gang_leader == NULL); 1480 ASSERT(pio->io_gang_tree == NULL); 1481 1482 pio->io_flags = pio->io_orig_flags; 1483 pio->io_stage = pio->io_orig_stage; 1484 pio->io_pipeline = pio->io_orig_pipeline; 1485 pio->io_reexecute = 0; 1486 pio->io_flags |= ZIO_FLAG_REEXECUTED; 1487 pio->io_error = 0; 1488 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1489 pio->io_state[w] = 0; 1490 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 1491 pio->io_child_error[c] = 0; 1492 1493 if (IO_IS_ALLOCATING(pio)) 1494 BP_ZERO(pio->io_bp); 1495 1496 /* 1497 * As we reexecute pio's children, new children could be created. 1498 * New children go to the head of pio's io_child_list, however, 1499 * so we will (correctly) not reexecute them. The key is that 1500 * the remainder of pio's io_child_list, from 'cio_next' onward, 1501 * cannot be affected by any side effects of reexecuting 'cio'. 1502 */ 1503 for (cio = zio_walk_children(pio); cio != NULL; cio = cio_next) { 1504 cio_next = zio_walk_children(pio); 1505 mutex_enter(&pio->io_lock); 1506 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1507 pio->io_children[cio->io_child_type][w]++; 1508 mutex_exit(&pio->io_lock); 1509 zio_reexecute(cio); 1510 } 1511 1512 /* 1513 * Now that all children have been reexecuted, execute the parent. 1514 * We don't reexecute "The Godfather" I/O here as it's the 1515 * responsibility of the caller to wait on him. 1516 */ 1517 if (!(pio->io_flags & ZIO_FLAG_GODFATHER)) 1518 zio_execute(pio); 1519 } 1520 1521 void 1522 zio_suspend(spa_t *spa, zio_t *zio) 1523 { 1524 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC) 1525 fm_panic("Pool '%s' has encountered an uncorrectable I/O " 1526 "failure and the failure mode property for this pool " 1527 "is set to panic.", spa_name(spa)); 1528 1529 zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL, NULL, 0, 0); 1530 1531 mutex_enter(&spa->spa_suspend_lock); 1532 1533 if (spa->spa_suspend_zio_root == NULL) 1534 spa->spa_suspend_zio_root = zio_root(spa, NULL, NULL, 1535 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | 1536 ZIO_FLAG_GODFATHER); 1537 1538 spa->spa_suspended = B_TRUE; 1539 1540 if (zio != NULL) { 1541 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 1542 ASSERT(zio != spa->spa_suspend_zio_root); 1543 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1544 ASSERT(zio_unique_parent(zio) == NULL); 1545 ASSERT(zio->io_stage == ZIO_STAGE_DONE); 1546 zio_add_child(spa->spa_suspend_zio_root, zio); 1547 } 1548 1549 mutex_exit(&spa->spa_suspend_lock); 1550 } 1551 1552 int 1553 zio_resume(spa_t *spa) 1554 { 1555 zio_t *pio; 1556 1557 /* 1558 * Reexecute all previously suspended i/o. 1559 */ 1560 mutex_enter(&spa->spa_suspend_lock); 1561 spa->spa_suspended = B_FALSE; 1562 cv_broadcast(&spa->spa_suspend_cv); 1563 pio = spa->spa_suspend_zio_root; 1564 spa->spa_suspend_zio_root = NULL; 1565 mutex_exit(&spa->spa_suspend_lock); 1566 1567 if (pio == NULL) 1568 return (0); 1569 1570 zio_reexecute(pio); 1571 return (zio_wait(pio)); 1572 } 1573 1574 void 1575 zio_resume_wait(spa_t *spa) 1576 { 1577 mutex_enter(&spa->spa_suspend_lock); 1578 while (spa_suspended(spa)) 1579 cv_wait(&spa->spa_suspend_cv, &spa->spa_suspend_lock); 1580 mutex_exit(&spa->spa_suspend_lock); 1581 } 1582 1583 /* 1584 * ========================================================================== 1585 * Gang blocks. 1586 * 1587 * A gang block is a collection of small blocks that looks to the DMU 1588 * like one large block. When zio_dva_allocate() cannot find a block 1589 * of the requested size, due to either severe fragmentation or the pool 1590 * being nearly full, it calls zio_write_gang_block() to construct the 1591 * block from smaller fragments. 1592 * 1593 * A gang block consists of a gang header (zio_gbh_phys_t) and up to 1594 * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like 1595 * an indirect block: it's an array of block pointers. It consumes 1596 * only one sector and hence is allocatable regardless of fragmentation. 1597 * The gang header's bps point to its gang members, which hold the data. 1598 * 1599 * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg> 1600 * as the verifier to ensure uniqueness of the SHA256 checksum. 1601 * Critically, the gang block bp's blk_cksum is the checksum of the data, 1602 * not the gang header. This ensures that data block signatures (needed for 1603 * deduplication) are independent of how the block is physically stored. 1604 * 1605 * Gang blocks can be nested: a gang member may itself be a gang block. 1606 * Thus every gang block is a tree in which root and all interior nodes are 1607 * gang headers, and the leaves are normal blocks that contain user data. 1608 * The root of the gang tree is called the gang leader. 1609 * 1610 * To perform any operation (read, rewrite, free, claim) on a gang block, 1611 * zio_gang_assemble() first assembles the gang tree (minus data leaves) 1612 * in the io_gang_tree field of the original logical i/o by recursively 1613 * reading the gang leader and all gang headers below it. This yields 1614 * an in-core tree containing the contents of every gang header and the 1615 * bps for every constituent of the gang block. 1616 * 1617 * With the gang tree now assembled, zio_gang_issue() just walks the gang tree 1618 * and invokes a callback on each bp. To free a gang block, zio_gang_issue() 1619 * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp. 1620 * zio_claim_gang() provides a similarly trivial wrapper for zio_claim(). 1621 * zio_read_gang() is a wrapper around zio_read() that omits reading gang 1622 * headers, since we already have those in io_gang_tree. zio_rewrite_gang() 1623 * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite() 1624 * of the gang header plus zio_checksum_compute() of the data to update the 1625 * gang header's blk_cksum as described above. 1626 * 1627 * The two-phase assemble/issue model solves the problem of partial failure -- 1628 * what if you'd freed part of a gang block but then couldn't read the 1629 * gang header for another part? Assembling the entire gang tree first 1630 * ensures that all the necessary gang header I/O has succeeded before 1631 * starting the actual work of free, claim, or write. Once the gang tree 1632 * is assembled, free and claim are in-memory operations that cannot fail. 1633 * 1634 * In the event that a gang write fails, zio_dva_unallocate() walks the 1635 * gang tree to immediately free (i.e. insert back into the space map) 1636 * everything we've allocated. This ensures that we don't get ENOSPC 1637 * errors during repeated suspend/resume cycles due to a flaky device. 1638 * 1639 * Gang rewrites only happen during sync-to-convergence. If we can't assemble 1640 * the gang tree, we won't modify the block, so we can safely defer the free 1641 * (knowing that the block is still intact). If we *can* assemble the gang 1642 * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free 1643 * each constituent bp and we can allocate a new block on the next sync pass. 1644 * 1645 * In all cases, the gang tree allows complete recovery from partial failure. 1646 * ========================================================================== 1647 */ 1648 1649 static zio_t * 1650 zio_read_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1651 { 1652 if (gn != NULL) 1653 return (pio); 1654 1655 return (zio_read(pio, pio->io_spa, bp, data, BP_GET_PSIZE(bp), 1656 NULL, NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 1657 &pio->io_bookmark)); 1658 } 1659 1660 zio_t * 1661 zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1662 { 1663 zio_t *zio; 1664 1665 if (gn != NULL) { 1666 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1667 gn->gn_gbh, SPA_GANGBLOCKSIZE, NULL, NULL, pio->io_priority, 1668 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1669 /* 1670 * As we rewrite each gang header, the pipeline will compute 1671 * a new gang block header checksum for it; but no one will 1672 * compute a new data checksum, so we do that here. The one 1673 * exception is the gang leader: the pipeline already computed 1674 * its data checksum because that stage precedes gang assembly. 1675 * (Presently, nothing actually uses interior data checksums; 1676 * this is just good hygiene.) 1677 */ 1678 if (gn != pio->io_gang_leader->io_gang_tree) { 1679 zio_checksum_compute(zio, BP_GET_CHECKSUM(bp), 1680 data, BP_GET_PSIZE(bp)); 1681 } 1682 /* 1683 * If we are here to damage data for testing purposes, 1684 * leave the GBH alone so that we can detect the damage. 1685 */ 1686 if (pio->io_gang_leader->io_flags & ZIO_FLAG_INDUCE_DAMAGE) 1687 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 1688 } else { 1689 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1690 data, BP_GET_PSIZE(bp), NULL, NULL, pio->io_priority, 1691 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1692 } 1693 1694 return (zio); 1695 } 1696 1697 /* ARGSUSED */ 1698 zio_t * 1699 zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1700 { 1701 return (zio_free_sync(pio, pio->io_spa, pio->io_txg, bp, 1702 ZIO_GANG_CHILD_FLAGS(pio))); 1703 } 1704 1705 /* ARGSUSED */ 1706 zio_t * 1707 zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1708 { 1709 return (zio_claim(pio, pio->io_spa, pio->io_txg, bp, 1710 NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio))); 1711 } 1712 1713 static zio_gang_issue_func_t *zio_gang_issue_func[ZIO_TYPES] = { 1714 NULL, 1715 zio_read_gang, 1716 zio_rewrite_gang, 1717 zio_free_gang, 1718 zio_claim_gang, 1719 NULL 1720 }; 1721 1722 static void zio_gang_tree_assemble_done(zio_t *zio); 1723 1724 static zio_gang_node_t * 1725 zio_gang_node_alloc(zio_gang_node_t **gnpp) 1726 { 1727 zio_gang_node_t *gn; 1728 1729 ASSERT(*gnpp == NULL); 1730 1731 gn = kmem_zalloc(sizeof (*gn), KM_SLEEP); 1732 gn->gn_gbh = zio_buf_alloc(SPA_GANGBLOCKSIZE); 1733 *gnpp = gn; 1734 1735 return (gn); 1736 } 1737 1738 static void 1739 zio_gang_node_free(zio_gang_node_t **gnpp) 1740 { 1741 zio_gang_node_t *gn = *gnpp; 1742 1743 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 1744 ASSERT(gn->gn_child[g] == NULL); 1745 1746 zio_buf_free(gn->gn_gbh, SPA_GANGBLOCKSIZE); 1747 kmem_free(gn, sizeof (*gn)); 1748 *gnpp = NULL; 1749 } 1750 1751 static void 1752 zio_gang_tree_free(zio_gang_node_t **gnpp) 1753 { 1754 zio_gang_node_t *gn = *gnpp; 1755 1756 if (gn == NULL) 1757 return; 1758 1759 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 1760 zio_gang_tree_free(&gn->gn_child[g]); 1761 1762 zio_gang_node_free(gnpp); 1763 } 1764 1765 static void 1766 zio_gang_tree_assemble(zio_t *gio, blkptr_t *bp, zio_gang_node_t **gnpp) 1767 { 1768 zio_gang_node_t *gn = zio_gang_node_alloc(gnpp); 1769 1770 ASSERT(gio->io_gang_leader == gio); 1771 ASSERT(BP_IS_GANG(bp)); 1772 1773 zio_nowait(zio_read(gio, gio->io_spa, bp, gn->gn_gbh, 1774 SPA_GANGBLOCKSIZE, zio_gang_tree_assemble_done, gn, 1775 gio->io_priority, ZIO_GANG_CHILD_FLAGS(gio), &gio->io_bookmark)); 1776 } 1777 1778 static void 1779 zio_gang_tree_assemble_done(zio_t *zio) 1780 { 1781 zio_t *gio = zio->io_gang_leader; 1782 zio_gang_node_t *gn = zio->io_private; 1783 blkptr_t *bp = zio->io_bp; 1784 1785 ASSERT(gio == zio_unique_parent(zio)); 1786 ASSERT(zio->io_child_count == 0); 1787 1788 if (zio->io_error) 1789 return; 1790 1791 if (BP_SHOULD_BYTESWAP(bp)) 1792 byteswap_uint64_array(zio->io_data, zio->io_size); 1793 1794 ASSERT(zio->io_data == gn->gn_gbh); 1795 ASSERT(zio->io_size == SPA_GANGBLOCKSIZE); 1796 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 1797 1798 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 1799 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 1800 if (!BP_IS_GANG(gbp)) 1801 continue; 1802 zio_gang_tree_assemble(gio, gbp, &gn->gn_child[g]); 1803 } 1804 } 1805 1806 static void 1807 zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, void *data) 1808 { 1809 zio_t *gio = pio->io_gang_leader; 1810 zio_t *zio; 1811 1812 ASSERT(BP_IS_GANG(bp) == !!gn); 1813 ASSERT(BP_GET_CHECKSUM(bp) == BP_GET_CHECKSUM(gio->io_bp)); 1814 ASSERT(BP_GET_LSIZE(bp) == BP_GET_PSIZE(bp) || gn == gio->io_gang_tree); 1815 1816 /* 1817 * If you're a gang header, your data is in gn->gn_gbh. 1818 * If you're a gang member, your data is in 'data' and gn == NULL. 1819 */ 1820 zio = zio_gang_issue_func[gio->io_type](pio, bp, gn, data); 1821 1822 if (gn != NULL) { 1823 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 1824 1825 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 1826 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 1827 if (BP_IS_HOLE(gbp)) 1828 continue; 1829 zio_gang_tree_issue(zio, gn->gn_child[g], gbp, data); 1830 data = (char *)data + BP_GET_PSIZE(gbp); 1831 } 1832 } 1833 1834 if (gn == gio->io_gang_tree) 1835 ASSERT3P((char *)gio->io_data + gio->io_size, ==, data); 1836 1837 if (zio != pio) 1838 zio_nowait(zio); 1839 } 1840 1841 static int 1842 zio_gang_assemble(zio_t *zio) 1843 { 1844 blkptr_t *bp = zio->io_bp; 1845 1846 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == NULL); 1847 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 1848 1849 zio->io_gang_leader = zio; 1850 1851 zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree); 1852 1853 return (ZIO_PIPELINE_CONTINUE); 1854 } 1855 1856 static int 1857 zio_gang_issue(zio_t *zio) 1858 { 1859 blkptr_t *bp = zio->io_bp; 1860 1861 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE)) 1862 return (ZIO_PIPELINE_STOP); 1863 1864 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio); 1865 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 1866 1867 if (zio->io_child_error[ZIO_CHILD_GANG] == 0) 1868 zio_gang_tree_issue(zio, zio->io_gang_tree, bp, zio->io_data); 1869 else 1870 zio_gang_tree_free(&zio->io_gang_tree); 1871 1872 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1873 1874 return (ZIO_PIPELINE_CONTINUE); 1875 } 1876 1877 static void 1878 zio_write_gang_member_ready(zio_t *zio) 1879 { 1880 zio_t *pio = zio_unique_parent(zio); 1881 zio_t *gio = zio->io_gang_leader; 1882 dva_t *cdva = zio->io_bp->blk_dva; 1883 dva_t *pdva = pio->io_bp->blk_dva; 1884 uint64_t asize; 1885 1886 if (BP_IS_HOLE(zio->io_bp)) 1887 return; 1888 1889 ASSERT(BP_IS_HOLE(&zio->io_bp_orig)); 1890 1891 ASSERT(zio->io_child_type == ZIO_CHILD_GANG); 1892 ASSERT3U(zio->io_prop.zp_copies, ==, gio->io_prop.zp_copies); 1893 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp)); 1894 ASSERT3U(pio->io_prop.zp_copies, <=, BP_GET_NDVAS(pio->io_bp)); 1895 ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp)); 1896 1897 mutex_enter(&pio->io_lock); 1898 for (int d = 0; d < BP_GET_NDVAS(zio->io_bp); d++) { 1899 ASSERT(DVA_GET_GANG(&pdva[d])); 1900 asize = DVA_GET_ASIZE(&pdva[d]); 1901 asize += DVA_GET_ASIZE(&cdva[d]); 1902 DVA_SET_ASIZE(&pdva[d], asize); 1903 } 1904 mutex_exit(&pio->io_lock); 1905 } 1906 1907 static int 1908 zio_write_gang_block(zio_t *pio) 1909 { 1910 spa_t *spa = pio->io_spa; 1911 blkptr_t *bp = pio->io_bp; 1912 zio_t *gio = pio->io_gang_leader; 1913 zio_t *zio; 1914 zio_gang_node_t *gn, **gnpp; 1915 zio_gbh_phys_t *gbh; 1916 uint64_t txg = pio->io_txg; 1917 uint64_t resid = pio->io_size; 1918 uint64_t lsize; 1919 int copies = gio->io_prop.zp_copies; 1920 int gbh_copies = MIN(copies + 1, spa_max_replication(spa)); 1921 zio_prop_t zp; 1922 int error; 1923 1924 error = metaslab_alloc(spa, spa_normal_class(spa), SPA_GANGBLOCKSIZE, 1925 bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp, 1926 METASLAB_HINTBP_FAVOR | METASLAB_GANG_HEADER); 1927 if (error) { 1928 pio->io_error = error; 1929 return (ZIO_PIPELINE_CONTINUE); 1930 } 1931 1932 if (pio == gio) { 1933 gnpp = &gio->io_gang_tree; 1934 } else { 1935 gnpp = pio->io_private; 1936 ASSERT(pio->io_ready == zio_write_gang_member_ready); 1937 } 1938 1939 gn = zio_gang_node_alloc(gnpp); 1940 gbh = gn->gn_gbh; 1941 bzero(gbh, SPA_GANGBLOCKSIZE); 1942 1943 /* 1944 * Create the gang header. 1945 */ 1946 zio = zio_rewrite(pio, spa, txg, bp, gbh, SPA_GANGBLOCKSIZE, NULL, NULL, 1947 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1948 1949 /* 1950 * Create and nowait the gang children. 1951 */ 1952 for (int g = 0; resid != 0; resid -= lsize, g++) { 1953 lsize = P2ROUNDUP(resid / (SPA_GBH_NBLKPTRS - g), 1954 SPA_MINBLOCKSIZE); 1955 ASSERT(lsize >= SPA_MINBLOCKSIZE && lsize <= resid); 1956 1957 zp.zp_checksum = gio->io_prop.zp_checksum; 1958 zp.zp_compress = ZIO_COMPRESS_OFF; 1959 zp.zp_type = DMU_OT_NONE; 1960 zp.zp_level = 0; 1961 zp.zp_copies = gio->io_prop.zp_copies; 1962 zp.zp_dedup = B_FALSE; 1963 zp.zp_dedup_verify = B_FALSE; 1964 zp.zp_nopwrite = B_FALSE; 1965 1966 zio_nowait(zio_write(zio, spa, txg, &gbh->zg_blkptr[g], 1967 (char *)pio->io_data + (pio->io_size - resid), lsize, &zp, 1968 zio_write_gang_member_ready, NULL, NULL, &gn->gn_child[g], 1969 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 1970 &pio->io_bookmark)); 1971 } 1972 1973 /* 1974 * Set pio's pipeline to just wait for zio to finish. 1975 */ 1976 pio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1977 1978 zio_nowait(zio); 1979 1980 return (ZIO_PIPELINE_CONTINUE); 1981 } 1982 1983 /* 1984 * The zio_nop_write stage in the pipeline determines if allocating 1985 * a new bp is necessary. By leveraging a cryptographically secure checksum, 1986 * such as SHA256, we can compare the checksums of the new data and the old 1987 * to determine if allocating a new block is required. The nopwrite 1988 * feature can handle writes in either syncing or open context (i.e. zil 1989 * writes) and as a result is mutually exclusive with dedup. 1990 */ 1991 static int 1992 zio_nop_write(zio_t *zio) 1993 { 1994 blkptr_t *bp = zio->io_bp; 1995 blkptr_t *bp_orig = &zio->io_bp_orig; 1996 zio_prop_t *zp = &zio->io_prop; 1997 1998 ASSERT(BP_GET_LEVEL(bp) == 0); 1999 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 2000 ASSERT(zp->zp_nopwrite); 2001 ASSERT(!zp->zp_dedup); 2002 ASSERT(zio->io_bp_override == NULL); 2003 ASSERT(IO_IS_ALLOCATING(zio)); 2004 2005 /* 2006 * Check to see if the original bp and the new bp have matching 2007 * characteristics (i.e. same checksum, compression algorithms, etc). 2008 * If they don't then just continue with the pipeline which will 2009 * allocate a new bp. 2010 */ 2011 if (BP_IS_HOLE(bp_orig) || 2012 !zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_dedup || 2013 BP_GET_CHECKSUM(bp) != BP_GET_CHECKSUM(bp_orig) || 2014 BP_GET_COMPRESS(bp) != BP_GET_COMPRESS(bp_orig) || 2015 BP_GET_DEDUP(bp) != BP_GET_DEDUP(bp_orig) || 2016 zp->zp_copies != BP_GET_NDVAS(bp_orig)) 2017 return (ZIO_PIPELINE_CONTINUE); 2018 2019 /* 2020 * If the checksums match then reset the pipeline so that we 2021 * avoid allocating a new bp and issuing any I/O. 2022 */ 2023 if (ZIO_CHECKSUM_EQUAL(bp->blk_cksum, bp_orig->blk_cksum)) { 2024 ASSERT(zio_checksum_table[zp->zp_checksum].ci_dedup); 2025 ASSERT3U(BP_GET_PSIZE(bp), ==, BP_GET_PSIZE(bp_orig)); 2026 ASSERT3U(BP_GET_LSIZE(bp), ==, BP_GET_LSIZE(bp_orig)); 2027 ASSERT(zp->zp_compress != ZIO_COMPRESS_OFF); 2028 ASSERT(bcmp(&bp->blk_prop, &bp_orig->blk_prop, 2029 sizeof (uint64_t)) == 0); 2030 2031 *bp = *bp_orig; 2032 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2033 zio->io_flags |= ZIO_FLAG_NOPWRITE; 2034 } 2035 2036 return (ZIO_PIPELINE_CONTINUE); 2037 } 2038 2039 /* 2040 * ========================================================================== 2041 * Dedup 2042 * ========================================================================== 2043 */ 2044 static void 2045 zio_ddt_child_read_done(zio_t *zio) 2046 { 2047 blkptr_t *bp = zio->io_bp; 2048 ddt_entry_t *dde = zio->io_private; 2049 ddt_phys_t *ddp; 2050 zio_t *pio = zio_unique_parent(zio); 2051 2052 mutex_enter(&pio->io_lock); 2053 ddp = ddt_phys_select(dde, bp); 2054 if (zio->io_error == 0) 2055 ddt_phys_clear(ddp); /* this ddp doesn't need repair */ 2056 if (zio->io_error == 0 && dde->dde_repair_data == NULL) 2057 dde->dde_repair_data = zio->io_data; 2058 else 2059 zio_buf_free(zio->io_data, zio->io_size); 2060 mutex_exit(&pio->io_lock); 2061 } 2062 2063 static int 2064 zio_ddt_read_start(zio_t *zio) 2065 { 2066 blkptr_t *bp = zio->io_bp; 2067 2068 ASSERT(BP_GET_DEDUP(bp)); 2069 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 2070 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2071 2072 if (zio->io_child_error[ZIO_CHILD_DDT]) { 2073 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2074 ddt_entry_t *dde = ddt_repair_start(ddt, bp); 2075 ddt_phys_t *ddp = dde->dde_phys; 2076 ddt_phys_t *ddp_self = ddt_phys_select(dde, bp); 2077 blkptr_t blk; 2078 2079 ASSERT(zio->io_vsd == NULL); 2080 zio->io_vsd = dde; 2081 2082 if (ddp_self == NULL) 2083 return (ZIO_PIPELINE_CONTINUE); 2084 2085 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { 2086 if (ddp->ddp_phys_birth == 0 || ddp == ddp_self) 2087 continue; 2088 ddt_bp_create(ddt->ddt_checksum, &dde->dde_key, ddp, 2089 &blk); 2090 zio_nowait(zio_read(zio, zio->io_spa, &blk, 2091 zio_buf_alloc(zio->io_size), zio->io_size, 2092 zio_ddt_child_read_done, dde, zio->io_priority, 2093 ZIO_DDT_CHILD_FLAGS(zio) | ZIO_FLAG_DONT_PROPAGATE, 2094 &zio->io_bookmark)); 2095 } 2096 return (ZIO_PIPELINE_CONTINUE); 2097 } 2098 2099 zio_nowait(zio_read(zio, zio->io_spa, bp, 2100 zio->io_data, zio->io_size, NULL, NULL, zio->io_priority, 2101 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark)); 2102 2103 return (ZIO_PIPELINE_CONTINUE); 2104 } 2105 2106 static int 2107 zio_ddt_read_done(zio_t *zio) 2108 { 2109 blkptr_t *bp = zio->io_bp; 2110 2111 if (zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE)) 2112 return (ZIO_PIPELINE_STOP); 2113 2114 ASSERT(BP_GET_DEDUP(bp)); 2115 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 2116 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2117 2118 if (zio->io_child_error[ZIO_CHILD_DDT]) { 2119 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2120 ddt_entry_t *dde = zio->io_vsd; 2121 if (ddt == NULL) { 2122 ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE); 2123 return (ZIO_PIPELINE_CONTINUE); 2124 } 2125 if (dde == NULL) { 2126 zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1; 2127 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 2128 return (ZIO_PIPELINE_STOP); 2129 } 2130 if (dde->dde_repair_data != NULL) { 2131 bcopy(dde->dde_repair_data, zio->io_data, zio->io_size); 2132 zio->io_child_error[ZIO_CHILD_DDT] = 0; 2133 } 2134 ddt_repair_done(ddt, dde); 2135 zio->io_vsd = NULL; 2136 } 2137 2138 ASSERT(zio->io_vsd == NULL); 2139 2140 return (ZIO_PIPELINE_CONTINUE); 2141 } 2142 2143 static boolean_t 2144 zio_ddt_collision(zio_t *zio, ddt_t *ddt, ddt_entry_t *dde) 2145 { 2146 spa_t *spa = zio->io_spa; 2147 2148 /* 2149 * Note: we compare the original data, not the transformed data, 2150 * because when zio->io_bp is an override bp, we will not have 2151 * pushed the I/O transforms. That's an important optimization 2152 * because otherwise we'd compress/encrypt all dmu_sync() data twice. 2153 */ 2154 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 2155 zio_t *lio = dde->dde_lead_zio[p]; 2156 2157 if (lio != NULL) { 2158 return (lio->io_orig_size != zio->io_orig_size || 2159 bcmp(zio->io_orig_data, lio->io_orig_data, 2160 zio->io_orig_size) != 0); 2161 } 2162 } 2163 2164 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 2165 ddt_phys_t *ddp = &dde->dde_phys[p]; 2166 2167 if (ddp->ddp_phys_birth != 0) { 2168 arc_buf_t *abuf = NULL; 2169 arc_flags_t aflags = ARC_FLAG_WAIT; 2170 blkptr_t blk = *zio->io_bp; 2171 int error; 2172 2173 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth); 2174 2175 ddt_exit(ddt); 2176 2177 error = arc_read(NULL, spa, &blk, 2178 arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ, 2179 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, 2180 &aflags, &zio->io_bookmark); 2181 2182 if (error == 0) { 2183 if (arc_buf_size(abuf) != zio->io_orig_size || 2184 bcmp(abuf->b_data, zio->io_orig_data, 2185 zio->io_orig_size) != 0) 2186 error = SET_ERROR(EEXIST); 2187 VERIFY(arc_buf_remove_ref(abuf, &abuf)); 2188 } 2189 2190 ddt_enter(ddt); 2191 return (error != 0); 2192 } 2193 } 2194 2195 return (B_FALSE); 2196 } 2197 2198 static void 2199 zio_ddt_child_write_ready(zio_t *zio) 2200 { 2201 int p = zio->io_prop.zp_copies; 2202 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 2203 ddt_entry_t *dde = zio->io_private; 2204 ddt_phys_t *ddp = &dde->dde_phys[p]; 2205 zio_t *pio; 2206 2207 if (zio->io_error) 2208 return; 2209 2210 ddt_enter(ddt); 2211 2212 ASSERT(dde->dde_lead_zio[p] == zio); 2213 2214 ddt_phys_fill(ddp, zio->io_bp); 2215 2216 while ((pio = zio_walk_parents(zio)) != NULL) 2217 ddt_bp_fill(ddp, pio->io_bp, zio->io_txg); 2218 2219 ddt_exit(ddt); 2220 } 2221 2222 static void 2223 zio_ddt_child_write_done(zio_t *zio) 2224 { 2225 int p = zio->io_prop.zp_copies; 2226 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 2227 ddt_entry_t *dde = zio->io_private; 2228 ddt_phys_t *ddp = &dde->dde_phys[p]; 2229 2230 ddt_enter(ddt); 2231 2232 ASSERT(ddp->ddp_refcnt == 0); 2233 ASSERT(dde->dde_lead_zio[p] == zio); 2234 dde->dde_lead_zio[p] = NULL; 2235 2236 if (zio->io_error == 0) { 2237 while (zio_walk_parents(zio) != NULL) 2238 ddt_phys_addref(ddp); 2239 } else { 2240 ddt_phys_clear(ddp); 2241 } 2242 2243 ddt_exit(ddt); 2244 } 2245 2246 static void 2247 zio_ddt_ditto_write_done(zio_t *zio) 2248 { 2249 int p = DDT_PHYS_DITTO; 2250 zio_prop_t *zp = &zio->io_prop; 2251 blkptr_t *bp = zio->io_bp; 2252 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2253 ddt_entry_t *dde = zio->io_private; 2254 ddt_phys_t *ddp = &dde->dde_phys[p]; 2255 ddt_key_t *ddk = &dde->dde_key; 2256 2257 ddt_enter(ddt); 2258 2259 ASSERT(ddp->ddp_refcnt == 0); 2260 ASSERT(dde->dde_lead_zio[p] == zio); 2261 dde->dde_lead_zio[p] = NULL; 2262 2263 if (zio->io_error == 0) { 2264 ASSERT(ZIO_CHECKSUM_EQUAL(bp->blk_cksum, ddk->ddk_cksum)); 2265 ASSERT(zp->zp_copies < SPA_DVAS_PER_BP); 2266 ASSERT(zp->zp_copies == BP_GET_NDVAS(bp) - BP_IS_GANG(bp)); 2267 if (ddp->ddp_phys_birth != 0) 2268 ddt_phys_free(ddt, ddk, ddp, zio->io_txg); 2269 ddt_phys_fill(ddp, bp); 2270 } 2271 2272 ddt_exit(ddt); 2273 } 2274 2275 static int 2276 zio_ddt_write(zio_t *zio) 2277 { 2278 spa_t *spa = zio->io_spa; 2279 blkptr_t *bp = zio->io_bp; 2280 uint64_t txg = zio->io_txg; 2281 zio_prop_t *zp = &zio->io_prop; 2282 int p = zp->zp_copies; 2283 int ditto_copies; 2284 zio_t *cio = NULL; 2285 zio_t *dio = NULL; 2286 ddt_t *ddt = ddt_select(spa, bp); 2287 ddt_entry_t *dde; 2288 ddt_phys_t *ddp; 2289 2290 ASSERT(BP_GET_DEDUP(bp)); 2291 ASSERT(BP_GET_CHECKSUM(bp) == zp->zp_checksum); 2292 ASSERT(BP_IS_HOLE(bp) || zio->io_bp_override); 2293 2294 ddt_enter(ddt); 2295 dde = ddt_lookup(ddt, bp, B_TRUE); 2296 ddp = &dde->dde_phys[p]; 2297 2298 if (zp->zp_dedup_verify && zio_ddt_collision(zio, ddt, dde)) { 2299 /* 2300 * If we're using a weak checksum, upgrade to a strong checksum 2301 * and try again. If we're already using a strong checksum, 2302 * we can't resolve it, so just convert to an ordinary write. 2303 * (And automatically e-mail a paper to Nature?) 2304 */ 2305 if (!zio_checksum_table[zp->zp_checksum].ci_dedup) { 2306 zp->zp_checksum = spa_dedup_checksum(spa); 2307 zio_pop_transforms(zio); 2308 zio->io_stage = ZIO_STAGE_OPEN; 2309 BP_ZERO(bp); 2310 } else { 2311 zp->zp_dedup = B_FALSE; 2312 } 2313 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2314 ddt_exit(ddt); 2315 return (ZIO_PIPELINE_CONTINUE); 2316 } 2317 2318 ditto_copies = ddt_ditto_copies_needed(ddt, dde, ddp); 2319 ASSERT(ditto_copies < SPA_DVAS_PER_BP); 2320 2321 if (ditto_copies > ddt_ditto_copies_present(dde) && 2322 dde->dde_lead_zio[DDT_PHYS_DITTO] == NULL) { 2323 zio_prop_t czp = *zp; 2324 2325 czp.zp_copies = ditto_copies; 2326 2327 /* 2328 * If we arrived here with an override bp, we won't have run 2329 * the transform stack, so we won't have the data we need to 2330 * generate a child i/o. So, toss the override bp and restart. 2331 * This is safe, because using the override bp is just an 2332 * optimization; and it's rare, so the cost doesn't matter. 2333 */ 2334 if (zio->io_bp_override) { 2335 zio_pop_transforms(zio); 2336 zio->io_stage = ZIO_STAGE_OPEN; 2337 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2338 zio->io_bp_override = NULL; 2339 BP_ZERO(bp); 2340 ddt_exit(ddt); 2341 return (ZIO_PIPELINE_CONTINUE); 2342 } 2343 2344 dio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2345 zio->io_orig_size, &czp, NULL, NULL, 2346 zio_ddt_ditto_write_done, dde, zio->io_priority, 2347 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2348 2349 zio_push_transform(dio, zio->io_data, zio->io_size, 0, NULL); 2350 dde->dde_lead_zio[DDT_PHYS_DITTO] = dio; 2351 } 2352 2353 if (ddp->ddp_phys_birth != 0 || dde->dde_lead_zio[p] != NULL) { 2354 if (ddp->ddp_phys_birth != 0) 2355 ddt_bp_fill(ddp, bp, txg); 2356 if (dde->dde_lead_zio[p] != NULL) 2357 zio_add_child(zio, dde->dde_lead_zio[p]); 2358 else 2359 ddt_phys_addref(ddp); 2360 } else if (zio->io_bp_override) { 2361 ASSERT(bp->blk_birth == txg); 2362 ASSERT(BP_EQUAL(bp, zio->io_bp_override)); 2363 ddt_phys_fill(ddp, bp); 2364 ddt_phys_addref(ddp); 2365 } else { 2366 cio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2367 zio->io_orig_size, zp, zio_ddt_child_write_ready, NULL, 2368 zio_ddt_child_write_done, dde, zio->io_priority, 2369 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2370 2371 zio_push_transform(cio, zio->io_data, zio->io_size, 0, NULL); 2372 dde->dde_lead_zio[p] = cio; 2373 } 2374 2375 ddt_exit(ddt); 2376 2377 if (cio) 2378 zio_nowait(cio); 2379 if (dio) 2380 zio_nowait(dio); 2381 2382 return (ZIO_PIPELINE_CONTINUE); 2383 } 2384 2385 ddt_entry_t *freedde; /* for debugging */ 2386 2387 static int 2388 zio_ddt_free(zio_t *zio) 2389 { 2390 spa_t *spa = zio->io_spa; 2391 blkptr_t *bp = zio->io_bp; 2392 ddt_t *ddt = ddt_select(spa, bp); 2393 ddt_entry_t *dde; 2394 ddt_phys_t *ddp; 2395 2396 ASSERT(BP_GET_DEDUP(bp)); 2397 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2398 2399 ddt_enter(ddt); 2400 freedde = dde = ddt_lookup(ddt, bp, B_TRUE); 2401 ddp = ddt_phys_select(dde, bp); 2402 ddt_phys_decref(ddp); 2403 ddt_exit(ddt); 2404 2405 return (ZIO_PIPELINE_CONTINUE); 2406 } 2407 2408 /* 2409 * ========================================================================== 2410 * Allocate and free blocks 2411 * ========================================================================== 2412 */ 2413 static int 2414 zio_dva_allocate(zio_t *zio) 2415 { 2416 spa_t *spa = zio->io_spa; 2417 metaslab_class_t *mc = spa_normal_class(spa); 2418 blkptr_t *bp = zio->io_bp; 2419 int error; 2420 int flags = 0; 2421 2422 if (zio->io_gang_leader == NULL) { 2423 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2424 zio->io_gang_leader = zio; 2425 } 2426 2427 ASSERT(BP_IS_HOLE(bp)); 2428 ASSERT0(BP_GET_NDVAS(bp)); 2429 ASSERT3U(zio->io_prop.zp_copies, >, 0); 2430 ASSERT3U(zio->io_prop.zp_copies, <=, spa_max_replication(spa)); 2431 ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp)); 2432 2433 /* 2434 * The dump device does not support gang blocks so allocation on 2435 * behalf of the dump device (i.e. ZIO_FLAG_NODATA) must avoid 2436 * the "fast" gang feature. 2437 */ 2438 flags |= (zio->io_flags & ZIO_FLAG_NODATA) ? METASLAB_GANG_AVOID : 0; 2439 flags |= (zio->io_flags & ZIO_FLAG_GANG_CHILD) ? 2440 METASLAB_GANG_CHILD : 0; 2441 error = metaslab_alloc(spa, mc, zio->io_size, bp, 2442 zio->io_prop.zp_copies, zio->io_txg, NULL, flags); 2443 2444 if (error) { 2445 spa_dbgmsg(spa, "%s: metaslab allocation failure: zio %p, " 2446 "size %llu, error %d", spa_name(spa), zio, zio->io_size, 2447 error); 2448 if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE) 2449 return (zio_write_gang_block(zio)); 2450 zio->io_error = error; 2451 } 2452 2453 return (ZIO_PIPELINE_CONTINUE); 2454 } 2455 2456 static int 2457 zio_dva_free(zio_t *zio) 2458 { 2459 metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE); 2460 2461 return (ZIO_PIPELINE_CONTINUE); 2462 } 2463 2464 static int 2465 zio_dva_claim(zio_t *zio) 2466 { 2467 int error; 2468 2469 error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg); 2470 if (error) 2471 zio->io_error = error; 2472 2473 return (ZIO_PIPELINE_CONTINUE); 2474 } 2475 2476 /* 2477 * Undo an allocation. This is used by zio_done() when an I/O fails 2478 * and we want to give back the block we just allocated. 2479 * This handles both normal blocks and gang blocks. 2480 */ 2481 static void 2482 zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp) 2483 { 2484 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp)); 2485 ASSERT(zio->io_bp_override == NULL); 2486 2487 if (!BP_IS_HOLE(bp)) 2488 metaslab_free(zio->io_spa, bp, bp->blk_birth, B_TRUE); 2489 2490 if (gn != NULL) { 2491 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 2492 zio_dva_unallocate(zio, gn->gn_child[g], 2493 &gn->gn_gbh->zg_blkptr[g]); 2494 } 2495 } 2496 } 2497 2498 /* 2499 * Try to allocate an intent log block. Return 0 on success, errno on failure. 2500 */ 2501 int 2502 zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp, blkptr_t *old_bp, 2503 uint64_t size, boolean_t use_slog) 2504 { 2505 int error = 1; 2506 2507 ASSERT(txg > spa_syncing_txg(spa)); 2508 2509 /* 2510 * ZIL blocks are always contiguous (i.e. not gang blocks) so we 2511 * set the METASLAB_GANG_AVOID flag so that they don't "fast gang" 2512 * when allocating them. 2513 */ 2514 if (use_slog) { 2515 error = metaslab_alloc(spa, spa_log_class(spa), size, 2516 new_bp, 1, txg, old_bp, 2517 METASLAB_HINTBP_AVOID | METASLAB_GANG_AVOID); 2518 } 2519 2520 if (error) { 2521 error = metaslab_alloc(spa, spa_normal_class(spa), size, 2522 new_bp, 1, txg, old_bp, 2523 METASLAB_HINTBP_AVOID); 2524 } 2525 2526 if (error == 0) { 2527 BP_SET_LSIZE(new_bp, size); 2528 BP_SET_PSIZE(new_bp, size); 2529 BP_SET_COMPRESS(new_bp, ZIO_COMPRESS_OFF); 2530 BP_SET_CHECKSUM(new_bp, 2531 spa_version(spa) >= SPA_VERSION_SLIM_ZIL 2532 ? ZIO_CHECKSUM_ZILOG2 : ZIO_CHECKSUM_ZILOG); 2533 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG); 2534 BP_SET_LEVEL(new_bp, 0); 2535 BP_SET_DEDUP(new_bp, 0); 2536 BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER); 2537 } 2538 2539 return (error); 2540 } 2541 2542 /* 2543 * Free an intent log block. 2544 */ 2545 void 2546 zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp) 2547 { 2548 ASSERT(BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG); 2549 ASSERT(!BP_IS_GANG(bp)); 2550 2551 zio_free(spa, txg, bp); 2552 } 2553 2554 /* 2555 * ========================================================================== 2556 * Read and write to physical devices 2557 * ========================================================================== 2558 */ 2559 2560 2561 /* 2562 * Issue an I/O to the underlying vdev. Typically the issue pipeline 2563 * stops after this stage and will resume upon I/O completion. 2564 * However, there are instances where the vdev layer may need to 2565 * continue the pipeline when an I/O was not issued. Since the I/O 2566 * that was sent to the vdev layer might be different than the one 2567 * currently active in the pipeline (see vdev_queue_io()), we explicitly 2568 * force the underlying vdev layers to call either zio_execute() or 2569 * zio_interrupt() to ensure that the pipeline continues with the correct I/O. 2570 */ 2571 static int 2572 zio_vdev_io_start(zio_t *zio) 2573 { 2574 vdev_t *vd = zio->io_vd; 2575 uint64_t align; 2576 spa_t *spa = zio->io_spa; 2577 2578 ASSERT(zio->io_error == 0); 2579 ASSERT(zio->io_child_error[ZIO_CHILD_VDEV] == 0); 2580 2581 if (vd == NULL) { 2582 if (!(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 2583 spa_config_enter(spa, SCL_ZIO, zio, RW_READER); 2584 2585 /* 2586 * The mirror_ops handle multiple DVAs in a single BP. 2587 */ 2588 vdev_mirror_ops.vdev_op_io_start(zio); 2589 return (ZIO_PIPELINE_STOP); 2590 } 2591 2592 /* 2593 * We keep track of time-sensitive I/Os so that the scan thread 2594 * can quickly react to certain workloads. In particular, we care 2595 * about non-scrubbing, top-level reads and writes with the following 2596 * characteristics: 2597 * - synchronous writes of user data to non-slog devices 2598 * - any reads of user data 2599 * When these conditions are met, adjust the timestamp of spa_last_io 2600 * which allows the scan thread to adjust its workload accordingly. 2601 */ 2602 if (!(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && zio->io_bp != NULL && 2603 vd == vd->vdev_top && !vd->vdev_islog && 2604 zio->io_bookmark.zb_objset != DMU_META_OBJSET && 2605 zio->io_txg != spa_syncing_txg(spa)) { 2606 uint64_t old = spa->spa_last_io; 2607 uint64_t new = ddi_get_lbolt64(); 2608 if (old != new) 2609 (void) atomic_cas_64(&spa->spa_last_io, old, new); 2610 } 2611 2612 align = 1ULL << vd->vdev_top->vdev_ashift; 2613 2614 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL) && 2615 P2PHASE(zio->io_size, align) != 0) { 2616 /* Transform logical writes to be a full physical block size. */ 2617 uint64_t asize = P2ROUNDUP(zio->io_size, align); 2618 char *abuf = zio_buf_alloc(asize); 2619 ASSERT(vd == vd->vdev_top); 2620 if (zio->io_type == ZIO_TYPE_WRITE) { 2621 bcopy(zio->io_data, abuf, zio->io_size); 2622 bzero(abuf + zio->io_size, asize - zio->io_size); 2623 } 2624 zio_push_transform(zio, abuf, asize, asize, zio_subblock); 2625 } 2626 2627 /* 2628 * If this is not a physical io, make sure that it is properly aligned 2629 * before proceeding. 2630 */ 2631 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL)) { 2632 ASSERT0(P2PHASE(zio->io_offset, align)); 2633 ASSERT0(P2PHASE(zio->io_size, align)); 2634 } else { 2635 /* 2636 * For physical writes, we allow 512b aligned writes and assume 2637 * the device will perform a read-modify-write as necessary. 2638 */ 2639 ASSERT0(P2PHASE(zio->io_offset, SPA_MINBLOCKSIZE)); 2640 ASSERT0(P2PHASE(zio->io_size, SPA_MINBLOCKSIZE)); 2641 } 2642 2643 VERIFY(zio->io_type != ZIO_TYPE_WRITE || spa_writeable(spa)); 2644 2645 /* 2646 * If this is a repair I/O, and there's no self-healing involved -- 2647 * that is, we're just resilvering what we expect to resilver -- 2648 * then don't do the I/O unless zio's txg is actually in vd's DTL. 2649 * This prevents spurious resilvering with nested replication. 2650 * For example, given a mirror of mirrors, (A+B)+(C+D), if only 2651 * A is out of date, we'll read from C+D, then use the data to 2652 * resilver A+B -- but we don't actually want to resilver B, just A. 2653 * The top-level mirror has no way to know this, so instead we just 2654 * discard unnecessary repairs as we work our way down the vdev tree. 2655 * The same logic applies to any form of nested replication: 2656 * ditto + mirror, RAID-Z + replacing, etc. This covers them all. 2657 */ 2658 if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) && 2659 !(zio->io_flags & ZIO_FLAG_SELF_HEAL) && 2660 zio->io_txg != 0 && /* not a delegated i/o */ 2661 !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) { 2662 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 2663 zio_vdev_io_bypass(zio); 2664 return (ZIO_PIPELINE_CONTINUE); 2665 } 2666 2667 if (vd->vdev_ops->vdev_op_leaf && 2668 (zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE)) { 2669 2670 if (zio->io_type == ZIO_TYPE_READ && vdev_cache_read(zio)) 2671 return (ZIO_PIPELINE_CONTINUE); 2672 2673 if ((zio = vdev_queue_io(zio)) == NULL) 2674 return (ZIO_PIPELINE_STOP); 2675 2676 if (!vdev_accessible(vd, zio)) { 2677 zio->io_error = SET_ERROR(ENXIO); 2678 zio_interrupt(zio); 2679 return (ZIO_PIPELINE_STOP); 2680 } 2681 } 2682 2683 vd->vdev_ops->vdev_op_io_start(zio); 2684 return (ZIO_PIPELINE_STOP); 2685 } 2686 2687 static int 2688 zio_vdev_io_done(zio_t *zio) 2689 { 2690 vdev_t *vd = zio->io_vd; 2691 vdev_ops_t *ops = vd ? vd->vdev_ops : &vdev_mirror_ops; 2692 boolean_t unexpected_error = B_FALSE; 2693 2694 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 2695 return (ZIO_PIPELINE_STOP); 2696 2697 ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE); 2698 2699 if (vd != NULL && vd->vdev_ops->vdev_op_leaf) { 2700 2701 vdev_queue_io_done(zio); 2702 2703 if (zio->io_type == ZIO_TYPE_WRITE) 2704 vdev_cache_write(zio); 2705 2706 if (zio_injection_enabled && zio->io_error == 0) 2707 zio->io_error = zio_handle_device_injection(vd, 2708 zio, EIO); 2709 2710 if (zio_injection_enabled && zio->io_error == 0) 2711 zio->io_error = zio_handle_label_injection(zio, EIO); 2712 2713 if (zio->io_error) { 2714 if (!vdev_accessible(vd, zio)) { 2715 zio->io_error = SET_ERROR(ENXIO); 2716 } else { 2717 unexpected_error = B_TRUE; 2718 } 2719 } 2720 } 2721 2722 ops->vdev_op_io_done(zio); 2723 2724 if (unexpected_error) 2725 VERIFY(vdev_probe(vd, zio) == NULL); 2726 2727 return (ZIO_PIPELINE_CONTINUE); 2728 } 2729 2730 /* 2731 * For non-raidz ZIOs, we can just copy aside the bad data read from the 2732 * disk, and use that to finish the checksum ereport later. 2733 */ 2734 static void 2735 zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr, 2736 const void *good_buf) 2737 { 2738 /* no processing needed */ 2739 zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE); 2740 } 2741 2742 /*ARGSUSED*/ 2743 void 2744 zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *ignored) 2745 { 2746 void *buf = zio_buf_alloc(zio->io_size); 2747 2748 bcopy(zio->io_data, buf, zio->io_size); 2749 2750 zcr->zcr_cbinfo = zio->io_size; 2751 zcr->zcr_cbdata = buf; 2752 zcr->zcr_finish = zio_vsd_default_cksum_finish; 2753 zcr->zcr_free = zio_buf_free; 2754 } 2755 2756 static int 2757 zio_vdev_io_assess(zio_t *zio) 2758 { 2759 vdev_t *vd = zio->io_vd; 2760 2761 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 2762 return (ZIO_PIPELINE_STOP); 2763 2764 if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 2765 spa_config_exit(zio->io_spa, SCL_ZIO, zio); 2766 2767 if (zio->io_vsd != NULL) { 2768 zio->io_vsd_ops->vsd_free(zio); 2769 zio->io_vsd = NULL; 2770 } 2771 2772 if (zio_injection_enabled && zio->io_error == 0) 2773 zio->io_error = zio_handle_fault_injection(zio, EIO); 2774 2775 /* 2776 * If the I/O failed, determine whether we should attempt to retry it. 2777 * 2778 * On retry, we cut in line in the issue queue, since we don't want 2779 * compression/checksumming/etc. work to prevent our (cheap) IO reissue. 2780 */ 2781 if (zio->io_error && vd == NULL && 2782 !(zio->io_flags & (ZIO_FLAG_DONT_RETRY | ZIO_FLAG_IO_RETRY))) { 2783 ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_QUEUE)); /* not a leaf */ 2784 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_BYPASS)); /* not a leaf */ 2785 zio->io_error = 0; 2786 zio->io_flags |= ZIO_FLAG_IO_RETRY | 2787 ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE; 2788 zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1; 2789 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, 2790 zio_requeue_io_start_cut_in_line); 2791 return (ZIO_PIPELINE_STOP); 2792 } 2793 2794 /* 2795 * If we got an error on a leaf device, convert it to ENXIO 2796 * if the device is not accessible at all. 2797 */ 2798 if (zio->io_error && vd != NULL && vd->vdev_ops->vdev_op_leaf && 2799 !vdev_accessible(vd, zio)) 2800 zio->io_error = SET_ERROR(ENXIO); 2801 2802 /* 2803 * If we can't write to an interior vdev (mirror or RAID-Z), 2804 * set vdev_cant_write so that we stop trying to allocate from it. 2805 */ 2806 if (zio->io_error == ENXIO && zio->io_type == ZIO_TYPE_WRITE && 2807 vd != NULL && !vd->vdev_ops->vdev_op_leaf) { 2808 vd->vdev_cant_write = B_TRUE; 2809 } 2810 2811 if (zio->io_error) 2812 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2813 2814 if (vd != NULL && vd->vdev_ops->vdev_op_leaf && 2815 zio->io_physdone != NULL) { 2816 ASSERT(!(zio->io_flags & ZIO_FLAG_DELEGATED)); 2817 ASSERT(zio->io_child_type == ZIO_CHILD_VDEV); 2818 zio->io_physdone(zio->io_logical); 2819 } 2820 2821 return (ZIO_PIPELINE_CONTINUE); 2822 } 2823 2824 void 2825 zio_vdev_io_reissue(zio_t *zio) 2826 { 2827 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 2828 ASSERT(zio->io_error == 0); 2829 2830 zio->io_stage >>= 1; 2831 } 2832 2833 void 2834 zio_vdev_io_redone(zio_t *zio) 2835 { 2836 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE); 2837 2838 zio->io_stage >>= 1; 2839 } 2840 2841 void 2842 zio_vdev_io_bypass(zio_t *zio) 2843 { 2844 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 2845 ASSERT(zio->io_error == 0); 2846 2847 zio->io_flags |= ZIO_FLAG_IO_BYPASS; 2848 zio->io_stage = ZIO_STAGE_VDEV_IO_ASSESS >> 1; 2849 } 2850 2851 /* 2852 * ========================================================================== 2853 * Generate and verify checksums 2854 * ========================================================================== 2855 */ 2856 static int 2857 zio_checksum_generate(zio_t *zio) 2858 { 2859 blkptr_t *bp = zio->io_bp; 2860 enum zio_checksum checksum; 2861 2862 if (bp == NULL) { 2863 /* 2864 * This is zio_write_phys(). 2865 * We're either generating a label checksum, or none at all. 2866 */ 2867 checksum = zio->io_prop.zp_checksum; 2868 2869 if (checksum == ZIO_CHECKSUM_OFF) 2870 return (ZIO_PIPELINE_CONTINUE); 2871 2872 ASSERT(checksum == ZIO_CHECKSUM_LABEL); 2873 } else { 2874 if (BP_IS_GANG(bp) && zio->io_child_type == ZIO_CHILD_GANG) { 2875 ASSERT(!IO_IS_ALLOCATING(zio)); 2876 checksum = ZIO_CHECKSUM_GANG_HEADER; 2877 } else { 2878 checksum = BP_GET_CHECKSUM(bp); 2879 } 2880 } 2881 2882 zio_checksum_compute(zio, checksum, zio->io_data, zio->io_size); 2883 2884 return (ZIO_PIPELINE_CONTINUE); 2885 } 2886 2887 static int 2888 zio_checksum_verify(zio_t *zio) 2889 { 2890 zio_bad_cksum_t info; 2891 blkptr_t *bp = zio->io_bp; 2892 int error; 2893 2894 ASSERT(zio->io_vd != NULL); 2895 2896 if (bp == NULL) { 2897 /* 2898 * This is zio_read_phys(). 2899 * We're either verifying a label checksum, or nothing at all. 2900 */ 2901 if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF) 2902 return (ZIO_PIPELINE_CONTINUE); 2903 2904 ASSERT(zio->io_prop.zp_checksum == ZIO_CHECKSUM_LABEL); 2905 } 2906 2907 if ((error = zio_checksum_error(zio, &info)) != 0) { 2908 zio->io_error = error; 2909 if (error == ECKSUM && 2910 !(zio->io_flags & ZIO_FLAG_SPECULATIVE)) { 2911 zfs_ereport_start_checksum(zio->io_spa, 2912 zio->io_vd, zio, zio->io_offset, 2913 zio->io_size, NULL, &info); 2914 } 2915 } 2916 2917 return (ZIO_PIPELINE_CONTINUE); 2918 } 2919 2920 /* 2921 * Called by RAID-Z to ensure we don't compute the checksum twice. 2922 */ 2923 void 2924 zio_checksum_verified(zio_t *zio) 2925 { 2926 zio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 2927 } 2928 2929 /* 2930 * ========================================================================== 2931 * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other. 2932 * An error of 0 indicates success. ENXIO indicates whole-device failure, 2933 * which may be transient (e.g. unplugged) or permament. ECKSUM and EIO 2934 * indicate errors that are specific to one I/O, and most likely permanent. 2935 * Any other error is presumed to be worse because we weren't expecting it. 2936 * ========================================================================== 2937 */ 2938 int 2939 zio_worst_error(int e1, int e2) 2940 { 2941 static int zio_error_rank[] = { 0, ENXIO, ECKSUM, EIO }; 2942 int r1, r2; 2943 2944 for (r1 = 0; r1 < sizeof (zio_error_rank) / sizeof (int); r1++) 2945 if (e1 == zio_error_rank[r1]) 2946 break; 2947 2948 for (r2 = 0; r2 < sizeof (zio_error_rank) / sizeof (int); r2++) 2949 if (e2 == zio_error_rank[r2]) 2950 break; 2951 2952 return (r1 > r2 ? e1 : e2); 2953 } 2954 2955 /* 2956 * ========================================================================== 2957 * I/O completion 2958 * ========================================================================== 2959 */ 2960 static int 2961 zio_ready(zio_t *zio) 2962 { 2963 blkptr_t *bp = zio->io_bp; 2964 zio_t *pio, *pio_next; 2965 2966 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 2967 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_READY)) 2968 return (ZIO_PIPELINE_STOP); 2969 2970 if (zio->io_ready) { 2971 ASSERT(IO_IS_ALLOCATING(zio)); 2972 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp) || 2973 (zio->io_flags & ZIO_FLAG_NOPWRITE)); 2974 ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0); 2975 2976 zio->io_ready(zio); 2977 } 2978 2979 if (bp != NULL && bp != &zio->io_bp_copy) 2980 zio->io_bp_copy = *bp; 2981 2982 if (zio->io_error) 2983 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2984 2985 mutex_enter(&zio->io_lock); 2986 zio->io_state[ZIO_WAIT_READY] = 1; 2987 pio = zio_walk_parents(zio); 2988 mutex_exit(&zio->io_lock); 2989 2990 /* 2991 * As we notify zio's parents, new parents could be added. 2992 * New parents go to the head of zio's io_parent_list, however, 2993 * so we will (correctly) not notify them. The remainder of zio's 2994 * io_parent_list, from 'pio_next' onward, cannot change because 2995 * all parents must wait for us to be done before they can be done. 2996 */ 2997 for (; pio != NULL; pio = pio_next) { 2998 pio_next = zio_walk_parents(zio); 2999 zio_notify_parent(pio, zio, ZIO_WAIT_READY); 3000 } 3001 3002 if (zio->io_flags & ZIO_FLAG_NODATA) { 3003 if (BP_IS_GANG(bp)) { 3004 zio->io_flags &= ~ZIO_FLAG_NODATA; 3005 } else { 3006 ASSERT((uintptr_t)zio->io_data < SPA_MAXBLOCKSIZE); 3007 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 3008 } 3009 } 3010 3011 if (zio_injection_enabled && 3012 zio->io_spa->spa_syncing_txg == zio->io_txg) 3013 zio_handle_ignored_writes(zio); 3014 3015 return (ZIO_PIPELINE_CONTINUE); 3016 } 3017 3018 static int 3019 zio_done(zio_t *zio) 3020 { 3021 spa_t *spa = zio->io_spa; 3022 zio_t *lio = zio->io_logical; 3023 blkptr_t *bp = zio->io_bp; 3024 vdev_t *vd = zio->io_vd; 3025 uint64_t psize = zio->io_size; 3026 zio_t *pio, *pio_next; 3027 3028 /* 3029 * If our children haven't all completed, 3030 * wait for them and then repeat this pipeline stage. 3031 */ 3032 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE) || 3033 zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE) || 3034 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE) || 3035 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_DONE)) 3036 return (ZIO_PIPELINE_STOP); 3037 3038 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 3039 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 3040 ASSERT(zio->io_children[c][w] == 0); 3041 3042 if (bp != NULL && !BP_IS_EMBEDDED(bp)) { 3043 ASSERT(bp->blk_pad[0] == 0); 3044 ASSERT(bp->blk_pad[1] == 0); 3045 ASSERT(bcmp(bp, &zio->io_bp_copy, sizeof (blkptr_t)) == 0 || 3046 (bp == zio_unique_parent(zio)->io_bp)); 3047 if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(bp) && 3048 zio->io_bp_override == NULL && 3049 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) { 3050 ASSERT(!BP_SHOULD_BYTESWAP(bp)); 3051 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(bp)); 3052 ASSERT(BP_COUNT_GANG(bp) == 0 || 3053 (BP_COUNT_GANG(bp) == BP_GET_NDVAS(bp))); 3054 } 3055 if (zio->io_flags & ZIO_FLAG_NOPWRITE) 3056 VERIFY(BP_EQUAL(bp, &zio->io_bp_orig)); 3057 } 3058 3059 /* 3060 * If there were child vdev/gang/ddt errors, they apply to us now. 3061 */ 3062 zio_inherit_child_errors(zio, ZIO_CHILD_VDEV); 3063 zio_inherit_child_errors(zio, ZIO_CHILD_GANG); 3064 zio_inherit_child_errors(zio, ZIO_CHILD_DDT); 3065 3066 /* 3067 * If the I/O on the transformed data was successful, generate any 3068 * checksum reports now while we still have the transformed data. 3069 */ 3070 if (zio->io_error == 0) { 3071 while (zio->io_cksum_report != NULL) { 3072 zio_cksum_report_t *zcr = zio->io_cksum_report; 3073 uint64_t align = zcr->zcr_align; 3074 uint64_t asize = P2ROUNDUP(psize, align); 3075 char *abuf = zio->io_data; 3076 3077 if (asize != psize) { 3078 abuf = zio_buf_alloc(asize); 3079 bcopy(zio->io_data, abuf, psize); 3080 bzero(abuf + psize, asize - psize); 3081 } 3082 3083 zio->io_cksum_report = zcr->zcr_next; 3084 zcr->zcr_next = NULL; 3085 zcr->zcr_finish(zcr, abuf); 3086 zfs_ereport_free_checksum(zcr); 3087 3088 if (asize != psize) 3089 zio_buf_free(abuf, asize); 3090 } 3091 } 3092 3093 zio_pop_transforms(zio); /* note: may set zio->io_error */ 3094 3095 vdev_stat_update(zio, psize); 3096 3097 if (zio->io_error) { 3098 /* 3099 * If this I/O is attached to a particular vdev, 3100 * generate an error message describing the I/O failure 3101 * at the block level. We ignore these errors if the 3102 * device is currently unavailable. 3103 */ 3104 if (zio->io_error != ECKSUM && vd != NULL && !vdev_is_dead(vd)) 3105 zfs_ereport_post(FM_EREPORT_ZFS_IO, spa, vd, zio, 0, 0); 3106 3107 if ((zio->io_error == EIO || !(zio->io_flags & 3108 (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) && 3109 zio == lio) { 3110 /* 3111 * For logical I/O requests, tell the SPA to log the 3112 * error and generate a logical data ereport. 3113 */ 3114 spa_log_error(spa, zio); 3115 zfs_ereport_post(FM_EREPORT_ZFS_DATA, spa, NULL, zio, 3116 0, 0); 3117 } 3118 } 3119 3120 if (zio->io_error && zio == lio) { 3121 /* 3122 * Determine whether zio should be reexecuted. This will 3123 * propagate all the way to the root via zio_notify_parent(). 3124 */ 3125 ASSERT(vd == NULL && bp != NULL); 3126 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3127 3128 if (IO_IS_ALLOCATING(zio) && 3129 !(zio->io_flags & ZIO_FLAG_CANFAIL)) { 3130 if (zio->io_error != ENOSPC) 3131 zio->io_reexecute |= ZIO_REEXECUTE_NOW; 3132 else 3133 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3134 } 3135 3136 if ((zio->io_type == ZIO_TYPE_READ || 3137 zio->io_type == ZIO_TYPE_FREE) && 3138 !(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && 3139 zio->io_error == ENXIO && 3140 spa_load_state(spa) == SPA_LOAD_NONE && 3141 spa_get_failmode(spa) != ZIO_FAILURE_MODE_CONTINUE) 3142 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3143 3144 if (!(zio->io_flags & ZIO_FLAG_CANFAIL) && !zio->io_reexecute) 3145 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3146 3147 /* 3148 * Here is a possibly good place to attempt to do 3149 * either combinatorial reconstruction or error correction 3150 * based on checksums. It also might be a good place 3151 * to send out preliminary ereports before we suspend 3152 * processing. 3153 */ 3154 } 3155 3156 /* 3157 * If there were logical child errors, they apply to us now. 3158 * We defer this until now to avoid conflating logical child 3159 * errors with errors that happened to the zio itself when 3160 * updating vdev stats and reporting FMA events above. 3161 */ 3162 zio_inherit_child_errors(zio, ZIO_CHILD_LOGICAL); 3163 3164 if ((zio->io_error || zio->io_reexecute) && 3165 IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio && 3166 !(zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE))) 3167 zio_dva_unallocate(zio, zio->io_gang_tree, bp); 3168 3169 zio_gang_tree_free(&zio->io_gang_tree); 3170 3171 /* 3172 * Godfather I/Os should never suspend. 3173 */ 3174 if ((zio->io_flags & ZIO_FLAG_GODFATHER) && 3175 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) 3176 zio->io_reexecute = 0; 3177 3178 if (zio->io_reexecute) { 3179 /* 3180 * This is a logical I/O that wants to reexecute. 3181 * 3182 * Reexecute is top-down. When an i/o fails, if it's not 3183 * the root, it simply notifies its parent and sticks around. 3184 * The parent, seeing that it still has children in zio_done(), 3185 * does the same. This percolates all the way up to the root. 3186 * The root i/o will reexecute or suspend the entire tree. 3187 * 3188 * This approach ensures that zio_reexecute() honors 3189 * all the original i/o dependency relationships, e.g. 3190 * parents not executing until children are ready. 3191 */ 3192 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3193 3194 zio->io_gang_leader = NULL; 3195 3196 mutex_enter(&zio->io_lock); 3197 zio->io_state[ZIO_WAIT_DONE] = 1; 3198 mutex_exit(&zio->io_lock); 3199 3200 /* 3201 * "The Godfather" I/O monitors its children but is 3202 * not a true parent to them. It will track them through 3203 * the pipeline but severs its ties whenever they get into 3204 * trouble (e.g. suspended). This allows "The Godfather" 3205 * I/O to return status without blocking. 3206 */ 3207 for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) { 3208 zio_link_t *zl = zio->io_walk_link; 3209 pio_next = zio_walk_parents(zio); 3210 3211 if ((pio->io_flags & ZIO_FLAG_GODFATHER) && 3212 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) { 3213 zio_remove_child(pio, zio, zl); 3214 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3215 } 3216 } 3217 3218 if ((pio = zio_unique_parent(zio)) != NULL) { 3219 /* 3220 * We're not a root i/o, so there's nothing to do 3221 * but notify our parent. Don't propagate errors 3222 * upward since we haven't permanently failed yet. 3223 */ 3224 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 3225 zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE; 3226 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3227 } else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) { 3228 /* 3229 * We'd fail again if we reexecuted now, so suspend 3230 * until conditions improve (e.g. device comes online). 3231 */ 3232 zio_suspend(spa, zio); 3233 } else { 3234 /* 3235 * Reexecution is potentially a huge amount of work. 3236 * Hand it off to the otherwise-unused claim taskq. 3237 */ 3238 ASSERT(zio->io_tqent.tqent_next == NULL); 3239 spa_taskq_dispatch_ent(spa, ZIO_TYPE_CLAIM, 3240 ZIO_TASKQ_ISSUE, (task_func_t *)zio_reexecute, zio, 3241 0, &zio->io_tqent); 3242 } 3243 return (ZIO_PIPELINE_STOP); 3244 } 3245 3246 ASSERT(zio->io_child_count == 0); 3247 ASSERT(zio->io_reexecute == 0); 3248 ASSERT(zio->io_error == 0 || (zio->io_flags & ZIO_FLAG_CANFAIL)); 3249 3250 /* 3251 * Report any checksum errors, since the I/O is complete. 3252 */ 3253 while (zio->io_cksum_report != NULL) { 3254 zio_cksum_report_t *zcr = zio->io_cksum_report; 3255 zio->io_cksum_report = zcr->zcr_next; 3256 zcr->zcr_next = NULL; 3257 zcr->zcr_finish(zcr, NULL); 3258 zfs_ereport_free_checksum(zcr); 3259 } 3260 3261 /* 3262 * It is the responsibility of the done callback to ensure that this 3263 * particular zio is no longer discoverable for adoption, and as 3264 * such, cannot acquire any new parents. 3265 */ 3266 if (zio->io_done) 3267 zio->io_done(zio); 3268 3269 mutex_enter(&zio->io_lock); 3270 zio->io_state[ZIO_WAIT_DONE] = 1; 3271 mutex_exit(&zio->io_lock); 3272 3273 for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) { 3274 zio_link_t *zl = zio->io_walk_link; 3275 pio_next = zio_walk_parents(zio); 3276 zio_remove_child(pio, zio, zl); 3277 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3278 } 3279 3280 if (zio->io_waiter != NULL) { 3281 mutex_enter(&zio->io_lock); 3282 zio->io_executor = NULL; 3283 cv_broadcast(&zio->io_cv); 3284 mutex_exit(&zio->io_lock); 3285 } else { 3286 zio_destroy(zio); 3287 } 3288 3289 return (ZIO_PIPELINE_STOP); 3290 } 3291 3292 /* 3293 * ========================================================================== 3294 * I/O pipeline definition 3295 * ========================================================================== 3296 */ 3297 static zio_pipe_stage_t *zio_pipeline[] = { 3298 NULL, 3299 zio_read_bp_init, 3300 zio_free_bp_init, 3301 zio_issue_async, 3302 zio_write_bp_init, 3303 zio_checksum_generate, 3304 zio_nop_write, 3305 zio_ddt_read_start, 3306 zio_ddt_read_done, 3307 zio_ddt_write, 3308 zio_ddt_free, 3309 zio_gang_assemble, 3310 zio_gang_issue, 3311 zio_dva_allocate, 3312 zio_dva_free, 3313 zio_dva_claim, 3314 zio_ready, 3315 zio_vdev_io_start, 3316 zio_vdev_io_done, 3317 zio_vdev_io_assess, 3318 zio_checksum_verify, 3319 zio_done 3320 }; 3321 3322 3323 3324 3325 /* 3326 * Compare two zbookmark_phys_t's to see which we would reach first in a 3327 * pre-order traversal of the object tree. 3328 * 3329 * This is simple in every case aside from the meta-dnode object. For all other 3330 * objects, we traverse them in order (object 1 before object 2, and so on). 3331 * However, all of these objects are traversed while traversing object 0, since 3332 * the data it points to is the list of objects. Thus, we need to convert to a 3333 * canonical representation so we can compare meta-dnode bookmarks to 3334 * non-meta-dnode bookmarks. 3335 * 3336 * We do this by calculating "equivalents" for each field of the zbookmark. 3337 * zbookmarks outside of the meta-dnode use their own object and level, and 3338 * calculate the level 0 equivalent (the first L0 blkid that is contained in the 3339 * blocks this bookmark refers to) by multiplying their blkid by their span 3340 * (the number of L0 blocks contained within one block at their level). 3341 * zbookmarks inside the meta-dnode calculate their object equivalent 3342 * (which is L0equiv * dnodes per data block), use 0 for their L0equiv, and use 3343 * level + 1<<31 (any value larger than a level could ever be) for their level. 3344 * This causes them to always compare before a bookmark in their object 3345 * equivalent, compare appropriately to bookmarks in other objects, and to 3346 * compare appropriately to other bookmarks in the meta-dnode. 3347 */ 3348 int 3349 zbookmark_compare(uint16_t dbss1, uint8_t ibs1, uint16_t dbss2, uint8_t ibs2, 3350 const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2) 3351 { 3352 /* 3353 * These variables represent the "equivalent" values for the zbookmark, 3354 * after converting zbookmarks inside the meta dnode to their 3355 * normal-object equivalents. 3356 */ 3357 uint64_t zb1obj, zb2obj; 3358 uint64_t zb1L0, zb2L0; 3359 uint64_t zb1level, zb2level; 3360 3361 if (zb1->zb_object == zb2->zb_object && 3362 zb1->zb_level == zb2->zb_level && 3363 zb1->zb_blkid == zb2->zb_blkid) 3364 return (0); 3365 3366 /* 3367 * BP_SPANB calculates the span in blocks. 3368 */ 3369 zb1L0 = (zb1->zb_blkid) * BP_SPANB(ibs1, zb1->zb_level); 3370 zb2L0 = (zb2->zb_blkid) * BP_SPANB(ibs2, zb2->zb_level); 3371 3372 if (zb1->zb_object == DMU_META_DNODE_OBJECT) { 3373 zb1obj = zb1L0 * (dbss1 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT)); 3374 zb1L0 = 0; 3375 zb1level = zb1->zb_level + COMPARE_META_LEVEL; 3376 } else { 3377 zb1obj = zb1->zb_object; 3378 zb1level = zb1->zb_level; 3379 } 3380 3381 if (zb2->zb_object == DMU_META_DNODE_OBJECT) { 3382 zb2obj = zb2L0 * (dbss2 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT)); 3383 zb2L0 = 0; 3384 zb2level = zb2->zb_level + COMPARE_META_LEVEL; 3385 } else { 3386 zb2obj = zb2->zb_object; 3387 zb2level = zb2->zb_level; 3388 } 3389 3390 /* Now that we have a canonical representation, do the comparison. */ 3391 if (zb1obj != zb2obj) 3392 return (zb1obj < zb2obj ? -1 : 1); 3393 else if (zb1L0 != zb2L0) 3394 return (zb1L0 < zb2L0 ? -1 : 1); 3395 else if (zb1level != zb2level) 3396 return (zb1level > zb2level ? -1 : 1); 3397 /* 3398 * This can (theoretically) happen if the bookmarks have the same object 3399 * and level, but different blkids, if the block sizes are not the same. 3400 * There is presently no way to change the indirect block sizes 3401 */ 3402 return (0); 3403 } 3404 3405 /* 3406 * This function checks the following: given that last_block is the place that 3407 * our traversal stopped last time, does that guarantee that we've visited 3408 * every node under subtree_root? Therefore, we can't just use the raw output 3409 * of zbookmark_compare. We have to pass in a modified version of 3410 * subtree_root; by incrementing the block id, and then checking whether 3411 * last_block is before or equal to that, we can tell whether or not having 3412 * visited last_block implies that all of subtree_root's children have been 3413 * visited. 3414 */ 3415 boolean_t 3416 zbookmark_subtree_completed(const dnode_phys_t *dnp, 3417 const zbookmark_phys_t *subtree_root, const zbookmark_phys_t *last_block) 3418 { 3419 zbookmark_phys_t mod_zb = *subtree_root; 3420 mod_zb.zb_blkid++; 3421 ASSERT(last_block->zb_level == 0); 3422 3423 /* The objset_phys_t isn't before anything. */ 3424 if (dnp == NULL) 3425 return (B_FALSE); 3426 3427 /* 3428 * We pass in 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT) for the 3429 * data block size in sectors, because that variable is only used if 3430 * the bookmark refers to a block in the meta-dnode. Since we don't 3431 * know without examining it what object it refers to, and there's no 3432 * harm in passing in this value in other cases, we always pass it in. 3433 * 3434 * We pass in 0 for the indirect block size shift because zb2 must be 3435 * level 0. The indirect block size is only used to calculate the span 3436 * of the bookmark, but since the bookmark must be level 0, the span is 3437 * always 1, so the math works out. 3438 * 3439 * If you make changes to how the zbookmark_compare code works, be sure 3440 * to make sure that this code still works afterwards. 3441 */ 3442 return (zbookmark_compare(dnp->dn_datablkszsec, dnp->dn_indblkshift, 3443 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT), 0, &mod_zb, 3444 last_block) <= 0); 3445 } 3446