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 /* 71 * The following actions directly effect the spa's sync-to-convergence logic. 72 * The values below define the sync pass when we start performing the action. 73 * Care should be taken when changing these values as they directly impact 74 * spa_sync() performance. Tuning these values may introduce subtle performance 75 * pathologies and should only be done in the context of performance analysis. 76 * These tunables will eventually be removed and replaced with #defines once 77 * enough analysis has been done to determine optimal values. 78 * 79 * The 'zfs_sync_pass_deferred_free' pass must be greater than 1 to ensure that 80 * regular blocks are not deferred. 81 */ 82 int zfs_sync_pass_deferred_free = 2; /* defer frees starting in this pass */ 83 int zfs_sync_pass_dont_compress = 5; /* don't compress starting in this pass */ 84 int zfs_sync_pass_rewrite = 2; /* rewrite new bps starting in this pass */ 85 86 /* 87 * An allocating zio is one that either currently has the DVA allocate 88 * stage set or will have it later in its lifetime. 89 */ 90 #define IO_IS_ALLOCATING(zio) ((zio)->io_orig_pipeline & ZIO_STAGE_DVA_ALLOCATE) 91 92 boolean_t zio_requeue_io_start_cut_in_line = B_TRUE; 93 94 #ifdef ZFS_DEBUG 95 int zio_buf_debug_limit = 16384; 96 #else 97 int zio_buf_debug_limit = 0; 98 #endif 99 100 void 101 zio_init(void) 102 { 103 size_t c; 104 vmem_t *data_alloc_arena = NULL; 105 106 #ifdef _KERNEL 107 data_alloc_arena = zio_alloc_arena; 108 #endif 109 zio_cache = kmem_cache_create("zio_cache", 110 sizeof (zio_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 111 zio_link_cache = kmem_cache_create("zio_link_cache", 112 sizeof (zio_link_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 113 114 /* 115 * For small buffers, we want a cache for each multiple of 116 * SPA_MINBLOCKSIZE. For larger buffers, we want a cache 117 * for each quarter-power of 2. 118 */ 119 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { 120 size_t size = (c + 1) << SPA_MINBLOCKSHIFT; 121 size_t p2 = size; 122 size_t align = 0; 123 size_t cflags = (size > zio_buf_debug_limit) ? KMC_NODEBUG : 0; 124 125 while (!ISP2(p2)) 126 p2 &= p2 - 1; 127 128 #ifndef _KERNEL 129 /* 130 * If we are using watchpoints, put each buffer on its own page, 131 * to eliminate the performance overhead of trapping to the 132 * kernel when modifying a non-watched buffer that shares the 133 * page with a watched buffer. 134 */ 135 if (arc_watch && !IS_P2ALIGNED(size, PAGESIZE)) 136 continue; 137 #endif 138 if (size <= 4 * SPA_MINBLOCKSIZE) { 139 align = SPA_MINBLOCKSIZE; 140 } else if (IS_P2ALIGNED(size, p2 >> 2)) { 141 align = MIN(p2 >> 2, PAGESIZE); 142 } 143 144 if (align != 0) { 145 char name[36]; 146 (void) sprintf(name, "zio_buf_%lu", (ulong_t)size); 147 zio_buf_cache[c] = kmem_cache_create(name, size, 148 align, NULL, NULL, NULL, NULL, NULL, cflags); 149 150 /* 151 * Since zio_data bufs do not appear in crash dumps, we 152 * pass KMC_NOTOUCH so that no allocator metadata is 153 * stored with the buffers. 154 */ 155 (void) sprintf(name, "zio_data_buf_%lu", (ulong_t)size); 156 zio_data_buf_cache[c] = kmem_cache_create(name, size, 157 align, NULL, NULL, NULL, NULL, data_alloc_arena, 158 cflags | KMC_NOTOUCH); 159 } 160 } 161 162 while (--c != 0) { 163 ASSERT(zio_buf_cache[c] != NULL); 164 if (zio_buf_cache[c - 1] == NULL) 165 zio_buf_cache[c - 1] = zio_buf_cache[c]; 166 167 ASSERT(zio_data_buf_cache[c] != NULL); 168 if (zio_data_buf_cache[c - 1] == NULL) 169 zio_data_buf_cache[c - 1] = zio_data_buf_cache[c]; 170 } 171 172 zio_inject_init(); 173 } 174 175 void 176 zio_fini(void) 177 { 178 size_t c; 179 kmem_cache_t *last_cache = NULL; 180 kmem_cache_t *last_data_cache = NULL; 181 182 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { 183 if (zio_buf_cache[c] != last_cache) { 184 last_cache = zio_buf_cache[c]; 185 kmem_cache_destroy(zio_buf_cache[c]); 186 } 187 zio_buf_cache[c] = NULL; 188 189 if (zio_data_buf_cache[c] != last_data_cache) { 190 last_data_cache = zio_data_buf_cache[c]; 191 kmem_cache_destroy(zio_data_buf_cache[c]); 192 } 193 zio_data_buf_cache[c] = NULL; 194 } 195 196 kmem_cache_destroy(zio_link_cache); 197 kmem_cache_destroy(zio_cache); 198 199 zio_inject_fini(); 200 } 201 202 /* 203 * ========================================================================== 204 * Allocate and free I/O buffers 205 * ========================================================================== 206 */ 207 208 /* 209 * Use zio_buf_alloc to allocate ZFS metadata. This data will appear in a 210 * crashdump if the kernel panics, so use it judiciously. Obviously, it's 211 * useful to inspect ZFS metadata, but if possible, we should avoid keeping 212 * excess / transient data in-core during a crashdump. 213 */ 214 void * 215 zio_buf_alloc(size_t size) 216 { 217 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 218 219 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 220 221 return (kmem_cache_alloc(zio_buf_cache[c], KM_PUSHPAGE)); 222 } 223 224 /* 225 * Use zio_data_buf_alloc to allocate data. The data will not appear in a 226 * crashdump if the kernel panics. This exists so that we will limit the amount 227 * of ZFS data that shows up in a kernel crashdump. (Thus reducing the amount 228 * of kernel heap dumped to disk when the kernel panics) 229 */ 230 void * 231 zio_data_buf_alloc(size_t size) 232 { 233 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 234 235 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 236 237 return (kmem_cache_alloc(zio_data_buf_cache[c], KM_PUSHPAGE)); 238 } 239 240 void 241 zio_buf_free(void *buf, size_t size) 242 { 243 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 244 245 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 246 247 kmem_cache_free(zio_buf_cache[c], buf); 248 } 249 250 void 251 zio_data_buf_free(void *buf, size_t size) 252 { 253 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 254 255 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 256 257 kmem_cache_free(zio_data_buf_cache[c], buf); 258 } 259 260 /* 261 * ========================================================================== 262 * Push and pop I/O transform buffers 263 * ========================================================================== 264 */ 265 static void 266 zio_push_transform(zio_t *zio, void *data, uint64_t size, uint64_t bufsize, 267 zio_transform_func_t *transform) 268 { 269 zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP); 270 271 zt->zt_orig_data = zio->io_data; 272 zt->zt_orig_size = zio->io_size; 273 zt->zt_bufsize = bufsize; 274 zt->zt_transform = transform; 275 276 zt->zt_next = zio->io_transform_stack; 277 zio->io_transform_stack = zt; 278 279 zio->io_data = data; 280 zio->io_size = size; 281 } 282 283 static void 284 zio_pop_transforms(zio_t *zio) 285 { 286 zio_transform_t *zt; 287 288 while ((zt = zio->io_transform_stack) != NULL) { 289 if (zt->zt_transform != NULL) 290 zt->zt_transform(zio, 291 zt->zt_orig_data, zt->zt_orig_size); 292 293 if (zt->zt_bufsize != 0) 294 zio_buf_free(zio->io_data, zt->zt_bufsize); 295 296 zio->io_data = zt->zt_orig_data; 297 zio->io_size = zt->zt_orig_size; 298 zio->io_transform_stack = zt->zt_next; 299 300 kmem_free(zt, sizeof (zio_transform_t)); 301 } 302 } 303 304 /* 305 * ========================================================================== 306 * I/O transform callbacks for subblocks and decompression 307 * ========================================================================== 308 */ 309 static void 310 zio_subblock(zio_t *zio, void *data, uint64_t size) 311 { 312 ASSERT(zio->io_size > size); 313 314 if (zio->io_type == ZIO_TYPE_READ) 315 bcopy(zio->io_data, data, size); 316 } 317 318 static void 319 zio_decompress(zio_t *zio, void *data, uint64_t size) 320 { 321 if (zio->io_error == 0 && 322 zio_decompress_data(BP_GET_COMPRESS(zio->io_bp), 323 zio->io_data, data, zio->io_size, size) != 0) 324 zio->io_error = SET_ERROR(EIO); 325 } 326 327 /* 328 * ========================================================================== 329 * I/O parent/child relationships and pipeline interlocks 330 * ========================================================================== 331 */ 332 /* 333 * NOTE - Callers to zio_walk_parents() and zio_walk_children must 334 * continue calling these functions until they return NULL. 335 * Otherwise, the next caller will pick up the list walk in 336 * some indeterminate state. (Otherwise every caller would 337 * have to pass in a cookie to keep the state represented by 338 * io_walk_link, which gets annoying.) 339 */ 340 zio_t * 341 zio_walk_parents(zio_t *cio) 342 { 343 zio_link_t *zl = cio->io_walk_link; 344 list_t *pl = &cio->io_parent_list; 345 346 zl = (zl == NULL) ? list_head(pl) : list_next(pl, zl); 347 cio->io_walk_link = zl; 348 349 if (zl == NULL) 350 return (NULL); 351 352 ASSERT(zl->zl_child == cio); 353 return (zl->zl_parent); 354 } 355 356 zio_t * 357 zio_walk_children(zio_t *pio) 358 { 359 zio_link_t *zl = pio->io_walk_link; 360 list_t *cl = &pio->io_child_list; 361 362 zl = (zl == NULL) ? list_head(cl) : list_next(cl, zl); 363 pio->io_walk_link = zl; 364 365 if (zl == NULL) 366 return (NULL); 367 368 ASSERT(zl->zl_parent == pio); 369 return (zl->zl_child); 370 } 371 372 zio_t * 373 zio_unique_parent(zio_t *cio) 374 { 375 zio_t *pio = zio_walk_parents(cio); 376 377 VERIFY(zio_walk_parents(cio) == NULL); 378 return (pio); 379 } 380 381 void 382 zio_add_child(zio_t *pio, zio_t *cio) 383 { 384 zio_link_t *zl = kmem_cache_alloc(zio_link_cache, KM_SLEEP); 385 386 /* 387 * Logical I/Os can have logical, gang, or vdev children. 388 * Gang I/Os can have gang or vdev children. 389 * Vdev I/Os can only have vdev children. 390 * The following ASSERT captures all of these constraints. 391 */ 392 ASSERT(cio->io_child_type <= pio->io_child_type); 393 394 zl->zl_parent = pio; 395 zl->zl_child = cio; 396 397 mutex_enter(&cio->io_lock); 398 mutex_enter(&pio->io_lock); 399 400 ASSERT(pio->io_state[ZIO_WAIT_DONE] == 0); 401 402 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 403 pio->io_children[cio->io_child_type][w] += !cio->io_state[w]; 404 405 list_insert_head(&pio->io_child_list, zl); 406 list_insert_head(&cio->io_parent_list, zl); 407 408 pio->io_child_count++; 409 cio->io_parent_count++; 410 411 mutex_exit(&pio->io_lock); 412 mutex_exit(&cio->io_lock); 413 } 414 415 static void 416 zio_remove_child(zio_t *pio, zio_t *cio, zio_link_t *zl) 417 { 418 ASSERT(zl->zl_parent == pio); 419 ASSERT(zl->zl_child == cio); 420 421 mutex_enter(&cio->io_lock); 422 mutex_enter(&pio->io_lock); 423 424 list_remove(&pio->io_child_list, zl); 425 list_remove(&cio->io_parent_list, zl); 426 427 pio->io_child_count--; 428 cio->io_parent_count--; 429 430 mutex_exit(&pio->io_lock); 431 mutex_exit(&cio->io_lock); 432 433 kmem_cache_free(zio_link_cache, zl); 434 } 435 436 static boolean_t 437 zio_wait_for_children(zio_t *zio, enum zio_child child, enum zio_wait_type wait) 438 { 439 uint64_t *countp = &zio->io_children[child][wait]; 440 boolean_t waiting = B_FALSE; 441 442 mutex_enter(&zio->io_lock); 443 ASSERT(zio->io_stall == NULL); 444 if (*countp != 0) { 445 zio->io_stage >>= 1; 446 zio->io_stall = countp; 447 waiting = B_TRUE; 448 } 449 mutex_exit(&zio->io_lock); 450 451 return (waiting); 452 } 453 454 static void 455 zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait) 456 { 457 uint64_t *countp = &pio->io_children[zio->io_child_type][wait]; 458 int *errorp = &pio->io_child_error[zio->io_child_type]; 459 460 mutex_enter(&pio->io_lock); 461 if (zio->io_error && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE)) 462 *errorp = zio_worst_error(*errorp, zio->io_error); 463 pio->io_reexecute |= zio->io_reexecute; 464 ASSERT3U(*countp, >, 0); 465 466 (*countp)--; 467 468 if (*countp == 0 && pio->io_stall == countp) { 469 pio->io_stall = NULL; 470 mutex_exit(&pio->io_lock); 471 zio_execute(pio); 472 } else { 473 mutex_exit(&pio->io_lock); 474 } 475 } 476 477 static void 478 zio_inherit_child_errors(zio_t *zio, enum zio_child c) 479 { 480 if (zio->io_child_error[c] != 0 && zio->io_error == 0) 481 zio->io_error = zio->io_child_error[c]; 482 } 483 484 /* 485 * ========================================================================== 486 * Create the various types of I/O (read, write, free, etc) 487 * ========================================================================== 488 */ 489 static zio_t * 490 zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 491 void *data, uint64_t size, zio_done_func_t *done, void *private, 492 zio_type_t type, zio_priority_t priority, enum zio_flag flags, 493 vdev_t *vd, uint64_t offset, const zbookmark_phys_t *zb, 494 enum zio_stage stage, enum zio_stage pipeline) 495 { 496 zio_t *zio; 497 498 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 499 ASSERT(P2PHASE(size, SPA_MINBLOCKSIZE) == 0); 500 ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0); 501 502 ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER)); 503 ASSERT(!bp || !(flags & ZIO_FLAG_CONFIG_WRITER)); 504 ASSERT(vd || stage == ZIO_STAGE_OPEN); 505 506 zio = kmem_cache_alloc(zio_cache, KM_SLEEP); 507 bzero(zio, sizeof (zio_t)); 508 509 mutex_init(&zio->io_lock, NULL, MUTEX_DEFAULT, NULL); 510 cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL); 511 512 list_create(&zio->io_parent_list, sizeof (zio_link_t), 513 offsetof(zio_link_t, zl_parent_node)); 514 list_create(&zio->io_child_list, sizeof (zio_link_t), 515 offsetof(zio_link_t, zl_child_node)); 516 517 if (vd != NULL) 518 zio->io_child_type = ZIO_CHILD_VDEV; 519 else if (flags & ZIO_FLAG_GANG_CHILD) 520 zio->io_child_type = ZIO_CHILD_GANG; 521 else if (flags & ZIO_FLAG_DDT_CHILD) 522 zio->io_child_type = ZIO_CHILD_DDT; 523 else 524 zio->io_child_type = ZIO_CHILD_LOGICAL; 525 526 if (bp != NULL) { 527 zio->io_bp = (blkptr_t *)bp; 528 zio->io_bp_copy = *bp; 529 zio->io_bp_orig = *bp; 530 if (type != ZIO_TYPE_WRITE || 531 zio->io_child_type == ZIO_CHILD_DDT) 532 zio->io_bp = &zio->io_bp_copy; /* so caller can free */ 533 if (zio->io_child_type == ZIO_CHILD_LOGICAL) 534 zio->io_logical = zio; 535 if (zio->io_child_type > ZIO_CHILD_GANG && BP_IS_GANG(bp)) 536 pipeline |= ZIO_GANG_STAGES; 537 } 538 539 zio->io_spa = spa; 540 zio->io_txg = txg; 541 zio->io_done = done; 542 zio->io_private = private; 543 zio->io_type = type; 544 zio->io_priority = priority; 545 zio->io_vd = vd; 546 zio->io_offset = offset; 547 zio->io_orig_data = zio->io_data = data; 548 zio->io_orig_size = zio->io_size = size; 549 zio->io_orig_flags = zio->io_flags = flags; 550 zio->io_orig_stage = zio->io_stage = stage; 551 zio->io_orig_pipeline = zio->io_pipeline = pipeline; 552 553 zio->io_state[ZIO_WAIT_READY] = (stage >= ZIO_STAGE_READY); 554 zio->io_state[ZIO_WAIT_DONE] = (stage >= ZIO_STAGE_DONE); 555 556 if (zb != NULL) 557 zio->io_bookmark = *zb; 558 559 if (pio != NULL) { 560 if (zio->io_logical == NULL) 561 zio->io_logical = pio->io_logical; 562 if (zio->io_child_type == ZIO_CHILD_GANG) 563 zio->io_gang_leader = pio->io_gang_leader; 564 zio_add_child(pio, zio); 565 } 566 567 return (zio); 568 } 569 570 static void 571 zio_destroy(zio_t *zio) 572 { 573 list_destroy(&zio->io_parent_list); 574 list_destroy(&zio->io_child_list); 575 mutex_destroy(&zio->io_lock); 576 cv_destroy(&zio->io_cv); 577 kmem_cache_free(zio_cache, zio); 578 } 579 580 zio_t * 581 zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, zio_done_func_t *done, 582 void *private, enum zio_flag flags) 583 { 584 zio_t *zio; 585 586 zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private, 587 ZIO_TYPE_NULL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL, 588 ZIO_STAGE_OPEN, ZIO_INTERLOCK_PIPELINE); 589 590 return (zio); 591 } 592 593 zio_t * 594 zio_root(spa_t *spa, zio_done_func_t *done, void *private, enum zio_flag flags) 595 { 596 return (zio_null(NULL, spa, NULL, done, private, flags)); 597 } 598 599 void 600 zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp) 601 { 602 if (!DMU_OT_IS_VALID(BP_GET_TYPE(bp))) { 603 zfs_panic_recover("blkptr at %p has invalid TYPE %llu", 604 bp, (longlong_t)BP_GET_TYPE(bp)); 605 } 606 if (BP_GET_CHECKSUM(bp) >= ZIO_CHECKSUM_FUNCTIONS || 607 BP_GET_CHECKSUM(bp) <= ZIO_CHECKSUM_ON) { 608 zfs_panic_recover("blkptr at %p has invalid CHECKSUM %llu", 609 bp, (longlong_t)BP_GET_CHECKSUM(bp)); 610 } 611 if (BP_GET_COMPRESS(bp) >= ZIO_COMPRESS_FUNCTIONS || 612 BP_GET_COMPRESS(bp) <= ZIO_COMPRESS_ON) { 613 zfs_panic_recover("blkptr at %p has invalid COMPRESS %llu", 614 bp, (longlong_t)BP_GET_COMPRESS(bp)); 615 } 616 if (BP_GET_LSIZE(bp) > SPA_MAXBLOCKSIZE) { 617 zfs_panic_recover("blkptr at %p has invalid LSIZE %llu", 618 bp, (longlong_t)BP_GET_LSIZE(bp)); 619 } 620 if (BP_GET_PSIZE(bp) > SPA_MAXBLOCKSIZE) { 621 zfs_panic_recover("blkptr at %p has invalid PSIZE %llu", 622 bp, (longlong_t)BP_GET_PSIZE(bp)); 623 } 624 625 if (BP_IS_EMBEDDED(bp)) { 626 if (BPE_GET_ETYPE(bp) > NUM_BP_EMBEDDED_TYPES) { 627 zfs_panic_recover("blkptr at %p has invalid ETYPE %llu", 628 bp, (longlong_t)BPE_GET_ETYPE(bp)); 629 } 630 } 631 632 /* 633 * Pool-specific checks. 634 * 635 * Note: it would be nice to verify that the blk_birth and 636 * BP_PHYSICAL_BIRTH() are not too large. However, spa_freeze() 637 * allows the birth time of log blocks (and dmu_sync()-ed blocks 638 * that are in the log) to be arbitrarily large. 639 */ 640 for (int i = 0; i < BP_GET_NDVAS(bp); i++) { 641 uint64_t vdevid = DVA_GET_VDEV(&bp->blk_dva[i]); 642 if (vdevid >= spa->spa_root_vdev->vdev_children) { 643 zfs_panic_recover("blkptr at %p DVA %u has invalid " 644 "VDEV %llu", 645 bp, i, (longlong_t)vdevid); 646 continue; 647 } 648 vdev_t *vd = spa->spa_root_vdev->vdev_child[vdevid]; 649 if (vd == NULL) { 650 zfs_panic_recover("blkptr at %p DVA %u has invalid " 651 "VDEV %llu", 652 bp, i, (longlong_t)vdevid); 653 continue; 654 } 655 if (vd->vdev_ops == &vdev_hole_ops) { 656 zfs_panic_recover("blkptr at %p DVA %u has hole " 657 "VDEV %llu", 658 bp, i, (longlong_t)vdevid); 659 continue; 660 } 661 if (vd->vdev_ops == &vdev_missing_ops) { 662 /* 663 * "missing" vdevs are valid during import, but we 664 * don't have their detailed info (e.g. asize), so 665 * we can't perform any more checks on them. 666 */ 667 continue; 668 } 669 uint64_t offset = DVA_GET_OFFSET(&bp->blk_dva[i]); 670 uint64_t asize = DVA_GET_ASIZE(&bp->blk_dva[i]); 671 if (BP_IS_GANG(bp)) 672 asize = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE); 673 if (offset + asize > vd->vdev_asize) { 674 zfs_panic_recover("blkptr at %p DVA %u has invalid " 675 "OFFSET %llu", 676 bp, i, (longlong_t)offset); 677 } 678 } 679 } 680 681 zio_t * 682 zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, 683 void *data, uint64_t size, zio_done_func_t *done, void *private, 684 zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb) 685 { 686 zio_t *zio; 687 688 zfs_blkptr_verify(spa, bp); 689 690 zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp, 691 data, size, done, private, 692 ZIO_TYPE_READ, priority, flags, NULL, 0, zb, 693 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 694 ZIO_DDT_CHILD_READ_PIPELINE : ZIO_READ_PIPELINE); 695 696 return (zio); 697 } 698 699 zio_t * 700 zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, 701 void *data, uint64_t size, const zio_prop_t *zp, 702 zio_done_func_t *ready, zio_done_func_t *physdone, zio_done_func_t *done, 703 void *private, 704 zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb) 705 { 706 zio_t *zio; 707 708 ASSERT(zp->zp_checksum >= ZIO_CHECKSUM_OFF && 709 zp->zp_checksum < ZIO_CHECKSUM_FUNCTIONS && 710 zp->zp_compress >= ZIO_COMPRESS_OFF && 711 zp->zp_compress < ZIO_COMPRESS_FUNCTIONS && 712 DMU_OT_IS_VALID(zp->zp_type) && 713 zp->zp_level < 32 && 714 zp->zp_copies > 0 && 715 zp->zp_copies <= spa_max_replication(spa)); 716 717 zio = zio_create(pio, spa, txg, bp, data, size, done, private, 718 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 719 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 720 ZIO_DDT_CHILD_WRITE_PIPELINE : ZIO_WRITE_PIPELINE); 721 722 zio->io_ready = ready; 723 zio->io_physdone = physdone; 724 zio->io_prop = *zp; 725 726 /* 727 * Data can be NULL if we are going to call zio_write_override() to 728 * provide the already-allocated BP. But we may need the data to 729 * verify a dedup hit (if requested). In this case, don't try to 730 * dedup (just take the already-allocated BP verbatim). 731 */ 732 if (data == NULL && zio->io_prop.zp_dedup_verify) { 733 zio->io_prop.zp_dedup = zio->io_prop.zp_dedup_verify = B_FALSE; 734 } 735 736 return (zio); 737 } 738 739 zio_t * 740 zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, void *data, 741 uint64_t size, zio_done_func_t *done, void *private, 742 zio_priority_t priority, enum zio_flag flags, zbookmark_phys_t *zb) 743 { 744 zio_t *zio; 745 746 zio = zio_create(pio, spa, txg, bp, data, size, done, private, 747 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 748 ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE); 749 750 return (zio); 751 } 752 753 void 754 zio_write_override(zio_t *zio, blkptr_t *bp, int copies, boolean_t nopwrite) 755 { 756 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 757 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 758 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 759 ASSERT(zio->io_txg == spa_syncing_txg(zio->io_spa)); 760 761 /* 762 * We must reset the io_prop to match the values that existed 763 * when the bp was first written by dmu_sync() keeping in mind 764 * that nopwrite and dedup are mutually exclusive. 765 */ 766 zio->io_prop.zp_dedup = nopwrite ? B_FALSE : zio->io_prop.zp_dedup; 767 zio->io_prop.zp_nopwrite = nopwrite; 768 zio->io_prop.zp_copies = copies; 769 zio->io_bp_override = bp; 770 } 771 772 void 773 zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp) 774 { 775 776 /* 777 * The check for EMBEDDED is a performance optimization. We 778 * process the free here (by ignoring it) rather than 779 * putting it on the list and then processing it in zio_free_sync(). 780 */ 781 if (BP_IS_EMBEDDED(bp)) 782 return; 783 metaslab_check_free(spa, bp); 784 785 /* 786 * Frees that are for the currently-syncing txg, are not going to be 787 * deferred, and which will not need to do a read (i.e. not GANG or 788 * DEDUP), can be processed immediately. Otherwise, put them on the 789 * in-memory list for later processing. 790 */ 791 if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp) || 792 txg != spa->spa_syncing_txg || 793 spa_sync_pass(spa) >= zfs_sync_pass_deferred_free) { 794 bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp); 795 } else { 796 VERIFY0(zio_wait(zio_free_sync(NULL, spa, txg, bp, 0))); 797 } 798 } 799 800 zio_t * 801 zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 802 enum zio_flag flags) 803 { 804 zio_t *zio; 805 enum zio_stage stage = ZIO_FREE_PIPELINE; 806 807 ASSERT(!BP_IS_HOLE(bp)); 808 ASSERT(spa_syncing_txg(spa) == txg); 809 ASSERT(spa_sync_pass(spa) < zfs_sync_pass_deferred_free); 810 811 if (BP_IS_EMBEDDED(bp)) 812 return (zio_null(pio, spa, NULL, NULL, NULL, 0)); 813 814 metaslab_check_free(spa, bp); 815 arc_freed(spa, bp); 816 817 /* 818 * GANG and DEDUP blocks can induce a read (for the gang block header, 819 * or the DDT), so issue them asynchronously so that this thread is 820 * not tied up. 821 */ 822 if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp)) 823 stage |= ZIO_STAGE_ISSUE_ASYNC; 824 825 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 826 NULL, NULL, ZIO_TYPE_FREE, ZIO_PRIORITY_NOW, flags, 827 NULL, 0, NULL, ZIO_STAGE_OPEN, stage); 828 829 return (zio); 830 } 831 832 zio_t * 833 zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 834 zio_done_func_t *done, void *private, enum zio_flag flags) 835 { 836 zio_t *zio; 837 838 dprintf_bp(bp, "claiming in txg %llu", txg); 839 840 if (BP_IS_EMBEDDED(bp)) 841 return (zio_null(pio, spa, NULL, NULL, NULL, 0)); 842 843 /* 844 * A claim is an allocation of a specific block. Claims are needed 845 * to support immediate writes in the intent log. The issue is that 846 * immediate writes contain committed data, but in a txg that was 847 * *not* committed. Upon opening the pool after an unclean shutdown, 848 * the intent log claims all blocks that contain immediate write data 849 * so that the SPA knows they're in use. 850 * 851 * All claims *must* be resolved in the first txg -- before the SPA 852 * starts allocating blocks -- so that nothing is allocated twice. 853 * If txg == 0 we just verify that the block is claimable. 854 */ 855 ASSERT3U(spa->spa_uberblock.ub_rootbp.blk_birth, <, spa_first_txg(spa)); 856 ASSERT(txg == spa_first_txg(spa) || txg == 0); 857 ASSERT(!BP_GET_DEDUP(bp) || !spa_writeable(spa)); /* zdb(1M) */ 858 859 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 860 done, private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW, flags, 861 NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE); 862 863 return (zio); 864 } 865 866 zio_t * 867 zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd, 868 zio_done_func_t *done, void *private, enum zio_flag flags) 869 { 870 zio_t *zio; 871 int c; 872 873 if (vd->vdev_children == 0) { 874 zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private, 875 ZIO_TYPE_IOCTL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL, 876 ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE); 877 878 zio->io_cmd = cmd; 879 } else { 880 zio = zio_null(pio, spa, NULL, NULL, NULL, flags); 881 882 for (c = 0; c < vd->vdev_children; c++) 883 zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd, 884 done, private, flags)); 885 } 886 887 return (zio); 888 } 889 890 zio_t * 891 zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 892 void *data, int checksum, zio_done_func_t *done, void *private, 893 zio_priority_t priority, enum zio_flag flags, boolean_t labels) 894 { 895 zio_t *zio; 896 897 ASSERT(vd->vdev_children == 0); 898 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 899 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 900 ASSERT3U(offset + size, <=, vd->vdev_psize); 901 902 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private, 903 ZIO_TYPE_READ, priority, flags | ZIO_FLAG_PHYSICAL, vd, offset, 904 NULL, ZIO_STAGE_OPEN, ZIO_READ_PHYS_PIPELINE); 905 906 zio->io_prop.zp_checksum = checksum; 907 908 return (zio); 909 } 910 911 zio_t * 912 zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 913 void *data, int checksum, zio_done_func_t *done, void *private, 914 zio_priority_t priority, enum zio_flag flags, boolean_t labels) 915 { 916 zio_t *zio; 917 918 ASSERT(vd->vdev_children == 0); 919 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 920 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 921 ASSERT3U(offset + size, <=, vd->vdev_psize); 922 923 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private, 924 ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_PHYSICAL, vd, offset, 925 NULL, ZIO_STAGE_OPEN, ZIO_WRITE_PHYS_PIPELINE); 926 927 zio->io_prop.zp_checksum = checksum; 928 929 if (zio_checksum_table[checksum].ci_eck) { 930 /* 931 * zec checksums are necessarily destructive -- they modify 932 * the end of the write buffer to hold the verifier/checksum. 933 * Therefore, we must make a local copy in case the data is 934 * being written to multiple places in parallel. 935 */ 936 void *wbuf = zio_buf_alloc(size); 937 bcopy(data, wbuf, size); 938 zio_push_transform(zio, wbuf, size, size, NULL); 939 } 940 941 return (zio); 942 } 943 944 /* 945 * Create a child I/O to do some work for us. 946 */ 947 zio_t * 948 zio_vdev_child_io(zio_t *pio, blkptr_t *bp, vdev_t *vd, uint64_t offset, 949 void *data, uint64_t size, int type, zio_priority_t priority, 950 enum zio_flag flags, zio_done_func_t *done, void *private) 951 { 952 enum zio_stage pipeline = ZIO_VDEV_CHILD_PIPELINE; 953 zio_t *zio; 954 955 ASSERT(vd->vdev_parent == 956 (pio->io_vd ? pio->io_vd : pio->io_spa->spa_root_vdev)); 957 958 if (type == ZIO_TYPE_READ && bp != NULL) { 959 /* 960 * If we have the bp, then the child should perform the 961 * checksum and the parent need not. This pushes error 962 * detection as close to the leaves as possible and 963 * eliminates redundant checksums in the interior nodes. 964 */ 965 pipeline |= ZIO_STAGE_CHECKSUM_VERIFY; 966 pio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 967 } 968 969 if (vd->vdev_children == 0) 970 offset += VDEV_LABEL_START_SIZE; 971 972 flags |= ZIO_VDEV_CHILD_FLAGS(pio) | ZIO_FLAG_DONT_PROPAGATE; 973 974 /* 975 * If we've decided to do a repair, the write is not speculative -- 976 * even if the original read was. 977 */ 978 if (flags & ZIO_FLAG_IO_REPAIR) 979 flags &= ~ZIO_FLAG_SPECULATIVE; 980 981 zio = zio_create(pio, pio->io_spa, pio->io_txg, bp, data, size, 982 done, private, type, priority, flags, vd, offset, &pio->io_bookmark, 983 ZIO_STAGE_VDEV_IO_START >> 1, pipeline); 984 985 zio->io_physdone = pio->io_physdone; 986 if (vd->vdev_ops->vdev_op_leaf && zio->io_logical != NULL) 987 zio->io_logical->io_phys_children++; 988 989 return (zio); 990 } 991 992 zio_t * 993 zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, void *data, uint64_t size, 994 int type, zio_priority_t priority, enum zio_flag flags, 995 zio_done_func_t *done, void *private) 996 { 997 zio_t *zio; 998 999 ASSERT(vd->vdev_ops->vdev_op_leaf); 1000 1001 zio = zio_create(NULL, vd->vdev_spa, 0, NULL, 1002 data, size, done, private, type, priority, 1003 flags | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY | ZIO_FLAG_DELEGATED, 1004 vd, offset, NULL, 1005 ZIO_STAGE_VDEV_IO_START >> 1, ZIO_VDEV_CHILD_PIPELINE); 1006 1007 return (zio); 1008 } 1009 1010 void 1011 zio_flush(zio_t *zio, vdev_t *vd) 1012 { 1013 zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE, 1014 NULL, NULL, 1015 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY)); 1016 } 1017 1018 void 1019 zio_shrink(zio_t *zio, uint64_t size) 1020 { 1021 ASSERT(zio->io_executor == NULL); 1022 ASSERT(zio->io_orig_size == zio->io_size); 1023 ASSERT(size <= zio->io_size); 1024 1025 /* 1026 * We don't shrink for raidz because of problems with the 1027 * reconstruction when reading back less than the block size. 1028 * Note, BP_IS_RAIDZ() assumes no compression. 1029 */ 1030 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 1031 if (!BP_IS_RAIDZ(zio->io_bp)) 1032 zio->io_orig_size = zio->io_size = size; 1033 } 1034 1035 /* 1036 * ========================================================================== 1037 * Prepare to read and write logical blocks 1038 * ========================================================================== 1039 */ 1040 1041 static int 1042 zio_read_bp_init(zio_t *zio) 1043 { 1044 blkptr_t *bp = zio->io_bp; 1045 1046 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF && 1047 zio->io_child_type == ZIO_CHILD_LOGICAL && 1048 !(zio->io_flags & ZIO_FLAG_RAW)) { 1049 uint64_t psize = 1050 BP_IS_EMBEDDED(bp) ? BPE_GET_PSIZE(bp) : BP_GET_PSIZE(bp); 1051 void *cbuf = zio_buf_alloc(psize); 1052 1053 zio_push_transform(zio, cbuf, psize, psize, zio_decompress); 1054 } 1055 1056 if (BP_IS_EMBEDDED(bp) && BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA) { 1057 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1058 decode_embedded_bp_compressed(bp, zio->io_data); 1059 } else { 1060 ASSERT(!BP_IS_EMBEDDED(bp)); 1061 } 1062 1063 if (!DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) && BP_GET_LEVEL(bp) == 0) 1064 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 1065 1066 if (BP_GET_TYPE(bp) == DMU_OT_DDT_ZAP) 1067 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 1068 1069 if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL) 1070 zio->io_pipeline = ZIO_DDT_READ_PIPELINE; 1071 1072 return (ZIO_PIPELINE_CONTINUE); 1073 } 1074 1075 static int 1076 zio_write_bp_init(zio_t *zio) 1077 { 1078 spa_t *spa = zio->io_spa; 1079 zio_prop_t *zp = &zio->io_prop; 1080 enum zio_compress compress = zp->zp_compress; 1081 blkptr_t *bp = zio->io_bp; 1082 uint64_t lsize = zio->io_size; 1083 uint64_t psize = lsize; 1084 int pass = 1; 1085 1086 /* 1087 * If our children haven't all reached the ready stage, 1088 * wait for them and then repeat this pipeline stage. 1089 */ 1090 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 1091 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_READY)) 1092 return (ZIO_PIPELINE_STOP); 1093 1094 if (!IO_IS_ALLOCATING(zio)) 1095 return (ZIO_PIPELINE_CONTINUE); 1096 1097 ASSERT(zio->io_child_type != ZIO_CHILD_DDT); 1098 1099 if (zio->io_bp_override) { 1100 ASSERT(bp->blk_birth != zio->io_txg); 1101 ASSERT(BP_GET_DEDUP(zio->io_bp_override) == 0); 1102 1103 *bp = *zio->io_bp_override; 1104 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1105 1106 if (BP_IS_EMBEDDED(bp)) 1107 return (ZIO_PIPELINE_CONTINUE); 1108 1109 /* 1110 * If we've been overridden and nopwrite is set then 1111 * set the flag accordingly to indicate that a nopwrite 1112 * has already occurred. 1113 */ 1114 if (!BP_IS_HOLE(bp) && zp->zp_nopwrite) { 1115 ASSERT(!zp->zp_dedup); 1116 zio->io_flags |= ZIO_FLAG_NOPWRITE; 1117 return (ZIO_PIPELINE_CONTINUE); 1118 } 1119 1120 ASSERT(!zp->zp_nopwrite); 1121 1122 if (BP_IS_HOLE(bp) || !zp->zp_dedup) 1123 return (ZIO_PIPELINE_CONTINUE); 1124 1125 ASSERT(zio_checksum_table[zp->zp_checksum].ci_dedup || 1126 zp->zp_dedup_verify); 1127 1128 if (BP_GET_CHECKSUM(bp) == zp->zp_checksum) { 1129 BP_SET_DEDUP(bp, 1); 1130 zio->io_pipeline |= ZIO_STAGE_DDT_WRITE; 1131 return (ZIO_PIPELINE_CONTINUE); 1132 } 1133 } 1134 1135 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg) { 1136 /* 1137 * We're rewriting an existing block, which means we're 1138 * working on behalf of spa_sync(). For spa_sync() to 1139 * converge, it must eventually be the case that we don't 1140 * have to allocate new blocks. But compression changes 1141 * the blocksize, which forces a reallocate, and makes 1142 * convergence take longer. Therefore, after the first 1143 * few passes, stop compressing to ensure convergence. 1144 */ 1145 pass = spa_sync_pass(spa); 1146 1147 ASSERT(zio->io_txg == spa_syncing_txg(spa)); 1148 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1149 ASSERT(!BP_GET_DEDUP(bp)); 1150 1151 if (pass >= zfs_sync_pass_dont_compress) 1152 compress = ZIO_COMPRESS_OFF; 1153 1154 /* Make sure someone doesn't change their mind on overwrites */ 1155 ASSERT(BP_IS_EMBEDDED(bp) || MIN(zp->zp_copies + BP_IS_GANG(bp), 1156 spa_max_replication(spa)) == BP_GET_NDVAS(bp)); 1157 } 1158 1159 if (compress != ZIO_COMPRESS_OFF) { 1160 void *cbuf = zio_buf_alloc(lsize); 1161 psize = zio_compress_data(compress, zio->io_data, cbuf, lsize); 1162 if (psize == 0 || psize == lsize) { 1163 compress = ZIO_COMPRESS_OFF; 1164 zio_buf_free(cbuf, lsize); 1165 } else if (!zp->zp_dedup && psize <= BPE_PAYLOAD_SIZE && 1166 zp->zp_level == 0 && !DMU_OT_HAS_FILL(zp->zp_type) && 1167 spa_feature_is_enabled(spa, SPA_FEATURE_EMBEDDED_DATA)) { 1168 encode_embedded_bp_compressed(bp, 1169 cbuf, compress, lsize, psize); 1170 BPE_SET_ETYPE(bp, BP_EMBEDDED_TYPE_DATA); 1171 BP_SET_TYPE(bp, zio->io_prop.zp_type); 1172 BP_SET_LEVEL(bp, zio->io_prop.zp_level); 1173 zio_buf_free(cbuf, lsize); 1174 bp->blk_birth = zio->io_txg; 1175 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1176 ASSERT(spa_feature_is_active(spa, 1177 SPA_FEATURE_EMBEDDED_DATA)); 1178 return (ZIO_PIPELINE_CONTINUE); 1179 } else { 1180 /* 1181 * Round up compressed size up to the ashift 1182 * of the smallest-ashift device, and zero the tail. 1183 * This ensures that the compressed size of the BP 1184 * (and thus compressratio property) are correct, 1185 * in that we charge for the padding used to fill out 1186 * the last sector. 1187 */ 1188 ASSERT3U(spa->spa_min_ashift, >=, SPA_MINBLOCKSHIFT); 1189 size_t rounded = (size_t)P2ROUNDUP(psize, 1190 1ULL << spa->spa_min_ashift); 1191 if (rounded >= lsize) { 1192 compress = ZIO_COMPRESS_OFF; 1193 zio_buf_free(cbuf, lsize); 1194 psize = lsize; 1195 } else { 1196 bzero((char *)cbuf + psize, rounded - psize); 1197 psize = rounded; 1198 zio_push_transform(zio, cbuf, 1199 psize, lsize, NULL); 1200 } 1201 } 1202 } 1203 1204 /* 1205 * The final pass of spa_sync() must be all rewrites, but the first 1206 * few passes offer a trade-off: allocating blocks defers convergence, 1207 * but newly allocated blocks are sequential, so they can be written 1208 * to disk faster. Therefore, we allow the first few passes of 1209 * spa_sync() to allocate new blocks, but force rewrites after that. 1210 * There should only be a handful of blocks after pass 1 in any case. 1211 */ 1212 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg && 1213 BP_GET_PSIZE(bp) == psize && 1214 pass >= zfs_sync_pass_rewrite) { 1215 ASSERT(psize != 0); 1216 enum zio_stage gang_stages = zio->io_pipeline & ZIO_GANG_STAGES; 1217 zio->io_pipeline = ZIO_REWRITE_PIPELINE | gang_stages; 1218 zio->io_flags |= ZIO_FLAG_IO_REWRITE; 1219 } else { 1220 BP_ZERO(bp); 1221 zio->io_pipeline = ZIO_WRITE_PIPELINE; 1222 } 1223 1224 if (psize == 0) { 1225 if (zio->io_bp_orig.blk_birth != 0 && 1226 spa_feature_is_active(spa, SPA_FEATURE_HOLE_BIRTH)) { 1227 BP_SET_LSIZE(bp, lsize); 1228 BP_SET_TYPE(bp, zp->zp_type); 1229 BP_SET_LEVEL(bp, zp->zp_level); 1230 BP_SET_BIRTH(bp, zio->io_txg, 0); 1231 } 1232 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1233 } else { 1234 ASSERT(zp->zp_checksum != ZIO_CHECKSUM_GANG_HEADER); 1235 BP_SET_LSIZE(bp, lsize); 1236 BP_SET_TYPE(bp, zp->zp_type); 1237 BP_SET_LEVEL(bp, zp->zp_level); 1238 BP_SET_PSIZE(bp, psize); 1239 BP_SET_COMPRESS(bp, compress); 1240 BP_SET_CHECKSUM(bp, zp->zp_checksum); 1241 BP_SET_DEDUP(bp, zp->zp_dedup); 1242 BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER); 1243 if (zp->zp_dedup) { 1244 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1245 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1246 zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE; 1247 } 1248 if (zp->zp_nopwrite) { 1249 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1250 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1251 zio->io_pipeline |= ZIO_STAGE_NOP_WRITE; 1252 } 1253 } 1254 1255 return (ZIO_PIPELINE_CONTINUE); 1256 } 1257 1258 static int 1259 zio_free_bp_init(zio_t *zio) 1260 { 1261 blkptr_t *bp = zio->io_bp; 1262 1263 if (zio->io_child_type == ZIO_CHILD_LOGICAL) { 1264 if (BP_GET_DEDUP(bp)) 1265 zio->io_pipeline = ZIO_DDT_FREE_PIPELINE; 1266 } 1267 1268 return (ZIO_PIPELINE_CONTINUE); 1269 } 1270 1271 /* 1272 * ========================================================================== 1273 * Execute the I/O pipeline 1274 * ========================================================================== 1275 */ 1276 1277 static void 1278 zio_taskq_dispatch(zio_t *zio, zio_taskq_type_t q, boolean_t cutinline) 1279 { 1280 spa_t *spa = zio->io_spa; 1281 zio_type_t t = zio->io_type; 1282 int flags = (cutinline ? TQ_FRONT : 0); 1283 1284 /* 1285 * If we're a config writer or a probe, the normal issue and 1286 * interrupt threads may all be blocked waiting for the config lock. 1287 * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL. 1288 */ 1289 if (zio->io_flags & (ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_PROBE)) 1290 t = ZIO_TYPE_NULL; 1291 1292 /* 1293 * A similar issue exists for the L2ARC write thread until L2ARC 2.0. 1294 */ 1295 if (t == ZIO_TYPE_WRITE && zio->io_vd && zio->io_vd->vdev_aux) 1296 t = ZIO_TYPE_NULL; 1297 1298 /* 1299 * If this is a high priority I/O, then use the high priority taskq if 1300 * available. 1301 */ 1302 if (zio->io_priority == ZIO_PRIORITY_NOW && 1303 spa->spa_zio_taskq[t][q + 1].stqs_count != 0) 1304 q++; 1305 1306 ASSERT3U(q, <, ZIO_TASKQ_TYPES); 1307 1308 /* 1309 * NB: We are assuming that the zio can only be dispatched 1310 * to a single taskq at a time. It would be a grievous error 1311 * to dispatch the zio to another taskq at the same time. 1312 */ 1313 ASSERT(zio->io_tqent.tqent_next == NULL); 1314 spa_taskq_dispatch_ent(spa, t, q, (task_func_t *)zio_execute, zio, 1315 flags, &zio->io_tqent); 1316 } 1317 1318 static boolean_t 1319 zio_taskq_member(zio_t *zio, zio_taskq_type_t q) 1320 { 1321 kthread_t *executor = zio->io_executor; 1322 spa_t *spa = zio->io_spa; 1323 1324 for (zio_type_t t = 0; t < ZIO_TYPES; t++) { 1325 spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q]; 1326 uint_t i; 1327 for (i = 0; i < tqs->stqs_count; i++) { 1328 if (taskq_member(tqs->stqs_taskq[i], executor)) 1329 return (B_TRUE); 1330 } 1331 } 1332 1333 return (B_FALSE); 1334 } 1335 1336 static int 1337 zio_issue_async(zio_t *zio) 1338 { 1339 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 1340 1341 return (ZIO_PIPELINE_STOP); 1342 } 1343 1344 void 1345 zio_interrupt(zio_t *zio) 1346 { 1347 zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE); 1348 } 1349 1350 /* 1351 * Execute the I/O pipeline until one of the following occurs: 1352 * 1353 * (1) the I/O completes 1354 * (2) the pipeline stalls waiting for dependent child I/Os 1355 * (3) the I/O issues, so we're waiting for an I/O completion interrupt 1356 * (4) the I/O is delegated by vdev-level caching or aggregation 1357 * (5) the I/O is deferred due to vdev-level queueing 1358 * (6) the I/O is handed off to another thread. 1359 * 1360 * In all cases, the pipeline stops whenever there's no CPU work; it never 1361 * burns a thread in cv_wait(). 1362 * 1363 * There's no locking on io_stage because there's no legitimate way 1364 * for multiple threads to be attempting to process the same I/O. 1365 */ 1366 static zio_pipe_stage_t *zio_pipeline[]; 1367 1368 void 1369 zio_execute(zio_t *zio) 1370 { 1371 zio->io_executor = curthread; 1372 1373 while (zio->io_stage < ZIO_STAGE_DONE) { 1374 enum zio_stage pipeline = zio->io_pipeline; 1375 enum zio_stage stage = zio->io_stage; 1376 int rv; 1377 1378 ASSERT(!MUTEX_HELD(&zio->io_lock)); 1379 ASSERT(ISP2(stage)); 1380 ASSERT(zio->io_stall == NULL); 1381 1382 do { 1383 stage <<= 1; 1384 } while ((stage & pipeline) == 0); 1385 1386 ASSERT(stage <= ZIO_STAGE_DONE); 1387 1388 /* 1389 * If we are in interrupt context and this pipeline stage 1390 * will grab a config lock that is held across I/O, 1391 * or may wait for an I/O that needs an interrupt thread 1392 * to complete, issue async to avoid deadlock. 1393 * 1394 * For VDEV_IO_START, we cut in line so that the io will 1395 * be sent to disk promptly. 1396 */ 1397 if ((stage & ZIO_BLOCKING_STAGES) && zio->io_vd == NULL && 1398 zio_taskq_member(zio, ZIO_TASKQ_INTERRUPT)) { 1399 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ? 1400 zio_requeue_io_start_cut_in_line : B_FALSE; 1401 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut); 1402 return; 1403 } 1404 1405 zio->io_stage = stage; 1406 rv = zio_pipeline[highbit64(stage) - 1](zio); 1407 1408 if (rv == ZIO_PIPELINE_STOP) 1409 return; 1410 1411 ASSERT(rv == ZIO_PIPELINE_CONTINUE); 1412 } 1413 } 1414 1415 /* 1416 * ========================================================================== 1417 * Initiate I/O, either sync or async 1418 * ========================================================================== 1419 */ 1420 int 1421 zio_wait(zio_t *zio) 1422 { 1423 int error; 1424 1425 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 1426 ASSERT(zio->io_executor == NULL); 1427 1428 zio->io_waiter = curthread; 1429 1430 zio_execute(zio); 1431 1432 mutex_enter(&zio->io_lock); 1433 while (zio->io_executor != NULL) 1434 cv_wait(&zio->io_cv, &zio->io_lock); 1435 mutex_exit(&zio->io_lock); 1436 1437 error = zio->io_error; 1438 zio_destroy(zio); 1439 1440 return (error); 1441 } 1442 1443 void 1444 zio_nowait(zio_t *zio) 1445 { 1446 ASSERT(zio->io_executor == NULL); 1447 1448 if (zio->io_child_type == ZIO_CHILD_LOGICAL && 1449 zio_unique_parent(zio) == NULL) { 1450 /* 1451 * This is a logical async I/O with no parent to wait for it. 1452 * We add it to the spa_async_root_zio "Godfather" I/O which 1453 * will ensure they complete prior to unloading the pool. 1454 */ 1455 spa_t *spa = zio->io_spa; 1456 1457 zio_add_child(spa->spa_async_zio_root[CPU_SEQID], zio); 1458 } 1459 1460 zio_execute(zio); 1461 } 1462 1463 /* 1464 * ========================================================================== 1465 * Reexecute or suspend/resume failed I/O 1466 * ========================================================================== 1467 */ 1468 1469 static void 1470 zio_reexecute(zio_t *pio) 1471 { 1472 zio_t *cio, *cio_next; 1473 1474 ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL); 1475 ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN); 1476 ASSERT(pio->io_gang_leader == NULL); 1477 ASSERT(pio->io_gang_tree == NULL); 1478 1479 pio->io_flags = pio->io_orig_flags; 1480 pio->io_stage = pio->io_orig_stage; 1481 pio->io_pipeline = pio->io_orig_pipeline; 1482 pio->io_reexecute = 0; 1483 pio->io_flags |= ZIO_FLAG_REEXECUTED; 1484 pio->io_error = 0; 1485 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1486 pio->io_state[w] = 0; 1487 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 1488 pio->io_child_error[c] = 0; 1489 1490 if (IO_IS_ALLOCATING(pio)) 1491 BP_ZERO(pio->io_bp); 1492 1493 /* 1494 * As we reexecute pio's children, new children could be created. 1495 * New children go to the head of pio's io_child_list, however, 1496 * so we will (correctly) not reexecute them. The key is that 1497 * the remainder of pio's io_child_list, from 'cio_next' onward, 1498 * cannot be affected by any side effects of reexecuting 'cio'. 1499 */ 1500 for (cio = zio_walk_children(pio); cio != NULL; cio = cio_next) { 1501 cio_next = zio_walk_children(pio); 1502 mutex_enter(&pio->io_lock); 1503 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1504 pio->io_children[cio->io_child_type][w]++; 1505 mutex_exit(&pio->io_lock); 1506 zio_reexecute(cio); 1507 } 1508 1509 /* 1510 * Now that all children have been reexecuted, execute the parent. 1511 * We don't reexecute "The Godfather" I/O here as it's the 1512 * responsibility of the caller to wait on him. 1513 */ 1514 if (!(pio->io_flags & ZIO_FLAG_GODFATHER)) 1515 zio_execute(pio); 1516 } 1517 1518 void 1519 zio_suspend(spa_t *spa, zio_t *zio) 1520 { 1521 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC) 1522 fm_panic("Pool '%s' has encountered an uncorrectable I/O " 1523 "failure and the failure mode property for this pool " 1524 "is set to panic.", spa_name(spa)); 1525 1526 zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL, NULL, 0, 0); 1527 1528 mutex_enter(&spa->spa_suspend_lock); 1529 1530 if (spa->spa_suspend_zio_root == NULL) 1531 spa->spa_suspend_zio_root = zio_root(spa, NULL, NULL, 1532 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | 1533 ZIO_FLAG_GODFATHER); 1534 1535 spa->spa_suspended = B_TRUE; 1536 1537 if (zio != NULL) { 1538 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 1539 ASSERT(zio != spa->spa_suspend_zio_root); 1540 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1541 ASSERT(zio_unique_parent(zio) == NULL); 1542 ASSERT(zio->io_stage == ZIO_STAGE_DONE); 1543 zio_add_child(spa->spa_suspend_zio_root, zio); 1544 } 1545 1546 mutex_exit(&spa->spa_suspend_lock); 1547 } 1548 1549 int 1550 zio_resume(spa_t *spa) 1551 { 1552 zio_t *pio; 1553 1554 /* 1555 * Reexecute all previously suspended i/o. 1556 */ 1557 mutex_enter(&spa->spa_suspend_lock); 1558 spa->spa_suspended = B_FALSE; 1559 cv_broadcast(&spa->spa_suspend_cv); 1560 pio = spa->spa_suspend_zio_root; 1561 spa->spa_suspend_zio_root = NULL; 1562 mutex_exit(&spa->spa_suspend_lock); 1563 1564 if (pio == NULL) 1565 return (0); 1566 1567 zio_reexecute(pio); 1568 return (zio_wait(pio)); 1569 } 1570 1571 void 1572 zio_resume_wait(spa_t *spa) 1573 { 1574 mutex_enter(&spa->spa_suspend_lock); 1575 while (spa_suspended(spa)) 1576 cv_wait(&spa->spa_suspend_cv, &spa->spa_suspend_lock); 1577 mutex_exit(&spa->spa_suspend_lock); 1578 } 1579 1580 /* 1581 * ========================================================================== 1582 * Gang blocks. 1583 * 1584 * A gang block is a collection of small blocks that looks to the DMU 1585 * like one large block. When zio_dva_allocate() cannot find a block 1586 * of the requested size, due to either severe fragmentation or the pool 1587 * being nearly full, it calls zio_write_gang_block() to construct the 1588 * block from smaller fragments. 1589 * 1590 * A gang block consists of a gang header (zio_gbh_phys_t) and up to 1591 * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like 1592 * an indirect block: it's an array of block pointers. It consumes 1593 * only one sector and hence is allocatable regardless of fragmentation. 1594 * The gang header's bps point to its gang members, which hold the data. 1595 * 1596 * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg> 1597 * as the verifier to ensure uniqueness of the SHA256 checksum. 1598 * Critically, the gang block bp's blk_cksum is the checksum of the data, 1599 * not the gang header. This ensures that data block signatures (needed for 1600 * deduplication) are independent of how the block is physically stored. 1601 * 1602 * Gang blocks can be nested: a gang member may itself be a gang block. 1603 * Thus every gang block is a tree in which root and all interior nodes are 1604 * gang headers, and the leaves are normal blocks that contain user data. 1605 * The root of the gang tree is called the gang leader. 1606 * 1607 * To perform any operation (read, rewrite, free, claim) on a gang block, 1608 * zio_gang_assemble() first assembles the gang tree (minus data leaves) 1609 * in the io_gang_tree field of the original logical i/o by recursively 1610 * reading the gang leader and all gang headers below it. This yields 1611 * an in-core tree containing the contents of every gang header and the 1612 * bps for every constituent of the gang block. 1613 * 1614 * With the gang tree now assembled, zio_gang_issue() just walks the gang tree 1615 * and invokes a callback on each bp. To free a gang block, zio_gang_issue() 1616 * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp. 1617 * zio_claim_gang() provides a similarly trivial wrapper for zio_claim(). 1618 * zio_read_gang() is a wrapper around zio_read() that omits reading gang 1619 * headers, since we already have those in io_gang_tree. zio_rewrite_gang() 1620 * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite() 1621 * of the gang header plus zio_checksum_compute() of the data to update the 1622 * gang header's blk_cksum as described above. 1623 * 1624 * The two-phase assemble/issue model solves the problem of partial failure -- 1625 * what if you'd freed part of a gang block but then couldn't read the 1626 * gang header for another part? Assembling the entire gang tree first 1627 * ensures that all the necessary gang header I/O has succeeded before 1628 * starting the actual work of free, claim, or write. Once the gang tree 1629 * is assembled, free and claim are in-memory operations that cannot fail. 1630 * 1631 * In the event that a gang write fails, zio_dva_unallocate() walks the 1632 * gang tree to immediately free (i.e. insert back into the space map) 1633 * everything we've allocated. This ensures that we don't get ENOSPC 1634 * errors during repeated suspend/resume cycles due to a flaky device. 1635 * 1636 * Gang rewrites only happen during sync-to-convergence. If we can't assemble 1637 * the gang tree, we won't modify the block, so we can safely defer the free 1638 * (knowing that the block is still intact). If we *can* assemble the gang 1639 * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free 1640 * each constituent bp and we can allocate a new block on the next sync pass. 1641 * 1642 * In all cases, the gang tree allows complete recovery from partial failure. 1643 * ========================================================================== 1644 */ 1645 1646 static zio_t * 1647 zio_read_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1648 { 1649 if (gn != NULL) 1650 return (pio); 1651 1652 return (zio_read(pio, pio->io_spa, bp, data, BP_GET_PSIZE(bp), 1653 NULL, NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 1654 &pio->io_bookmark)); 1655 } 1656 1657 zio_t * 1658 zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1659 { 1660 zio_t *zio; 1661 1662 if (gn != NULL) { 1663 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1664 gn->gn_gbh, SPA_GANGBLOCKSIZE, NULL, NULL, pio->io_priority, 1665 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1666 /* 1667 * As we rewrite each gang header, the pipeline will compute 1668 * a new gang block header checksum for it; but no one will 1669 * compute a new data checksum, so we do that here. The one 1670 * exception is the gang leader: the pipeline already computed 1671 * its data checksum because that stage precedes gang assembly. 1672 * (Presently, nothing actually uses interior data checksums; 1673 * this is just good hygiene.) 1674 */ 1675 if (gn != pio->io_gang_leader->io_gang_tree) { 1676 zio_checksum_compute(zio, BP_GET_CHECKSUM(bp), 1677 data, BP_GET_PSIZE(bp)); 1678 } 1679 /* 1680 * If we are here to damage data for testing purposes, 1681 * leave the GBH alone so that we can detect the damage. 1682 */ 1683 if (pio->io_gang_leader->io_flags & ZIO_FLAG_INDUCE_DAMAGE) 1684 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 1685 } else { 1686 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1687 data, BP_GET_PSIZE(bp), NULL, NULL, pio->io_priority, 1688 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1689 } 1690 1691 return (zio); 1692 } 1693 1694 /* ARGSUSED */ 1695 zio_t * 1696 zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1697 { 1698 return (zio_free_sync(pio, pio->io_spa, pio->io_txg, bp, 1699 ZIO_GANG_CHILD_FLAGS(pio))); 1700 } 1701 1702 /* ARGSUSED */ 1703 zio_t * 1704 zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1705 { 1706 return (zio_claim(pio, pio->io_spa, pio->io_txg, bp, 1707 NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio))); 1708 } 1709 1710 static zio_gang_issue_func_t *zio_gang_issue_func[ZIO_TYPES] = { 1711 NULL, 1712 zio_read_gang, 1713 zio_rewrite_gang, 1714 zio_free_gang, 1715 zio_claim_gang, 1716 NULL 1717 }; 1718 1719 static void zio_gang_tree_assemble_done(zio_t *zio); 1720 1721 static zio_gang_node_t * 1722 zio_gang_node_alloc(zio_gang_node_t **gnpp) 1723 { 1724 zio_gang_node_t *gn; 1725 1726 ASSERT(*gnpp == NULL); 1727 1728 gn = kmem_zalloc(sizeof (*gn), KM_SLEEP); 1729 gn->gn_gbh = zio_buf_alloc(SPA_GANGBLOCKSIZE); 1730 *gnpp = gn; 1731 1732 return (gn); 1733 } 1734 1735 static void 1736 zio_gang_node_free(zio_gang_node_t **gnpp) 1737 { 1738 zio_gang_node_t *gn = *gnpp; 1739 1740 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 1741 ASSERT(gn->gn_child[g] == NULL); 1742 1743 zio_buf_free(gn->gn_gbh, SPA_GANGBLOCKSIZE); 1744 kmem_free(gn, sizeof (*gn)); 1745 *gnpp = NULL; 1746 } 1747 1748 static void 1749 zio_gang_tree_free(zio_gang_node_t **gnpp) 1750 { 1751 zio_gang_node_t *gn = *gnpp; 1752 1753 if (gn == NULL) 1754 return; 1755 1756 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 1757 zio_gang_tree_free(&gn->gn_child[g]); 1758 1759 zio_gang_node_free(gnpp); 1760 } 1761 1762 static void 1763 zio_gang_tree_assemble(zio_t *gio, blkptr_t *bp, zio_gang_node_t **gnpp) 1764 { 1765 zio_gang_node_t *gn = zio_gang_node_alloc(gnpp); 1766 1767 ASSERT(gio->io_gang_leader == gio); 1768 ASSERT(BP_IS_GANG(bp)); 1769 1770 zio_nowait(zio_read(gio, gio->io_spa, bp, gn->gn_gbh, 1771 SPA_GANGBLOCKSIZE, zio_gang_tree_assemble_done, gn, 1772 gio->io_priority, ZIO_GANG_CHILD_FLAGS(gio), &gio->io_bookmark)); 1773 } 1774 1775 static void 1776 zio_gang_tree_assemble_done(zio_t *zio) 1777 { 1778 zio_t *gio = zio->io_gang_leader; 1779 zio_gang_node_t *gn = zio->io_private; 1780 blkptr_t *bp = zio->io_bp; 1781 1782 ASSERT(gio == zio_unique_parent(zio)); 1783 ASSERT(zio->io_child_count == 0); 1784 1785 if (zio->io_error) 1786 return; 1787 1788 if (BP_SHOULD_BYTESWAP(bp)) 1789 byteswap_uint64_array(zio->io_data, zio->io_size); 1790 1791 ASSERT(zio->io_data == gn->gn_gbh); 1792 ASSERT(zio->io_size == SPA_GANGBLOCKSIZE); 1793 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 1794 1795 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 1796 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 1797 if (!BP_IS_GANG(gbp)) 1798 continue; 1799 zio_gang_tree_assemble(gio, gbp, &gn->gn_child[g]); 1800 } 1801 } 1802 1803 static void 1804 zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, void *data) 1805 { 1806 zio_t *gio = pio->io_gang_leader; 1807 zio_t *zio; 1808 1809 ASSERT(BP_IS_GANG(bp) == !!gn); 1810 ASSERT(BP_GET_CHECKSUM(bp) == BP_GET_CHECKSUM(gio->io_bp)); 1811 ASSERT(BP_GET_LSIZE(bp) == BP_GET_PSIZE(bp) || gn == gio->io_gang_tree); 1812 1813 /* 1814 * If you're a gang header, your data is in gn->gn_gbh. 1815 * If you're a gang member, your data is in 'data' and gn == NULL. 1816 */ 1817 zio = zio_gang_issue_func[gio->io_type](pio, bp, gn, data); 1818 1819 if (gn != NULL) { 1820 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 1821 1822 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 1823 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 1824 if (BP_IS_HOLE(gbp)) 1825 continue; 1826 zio_gang_tree_issue(zio, gn->gn_child[g], gbp, data); 1827 data = (char *)data + BP_GET_PSIZE(gbp); 1828 } 1829 } 1830 1831 if (gn == gio->io_gang_tree) 1832 ASSERT3P((char *)gio->io_data + gio->io_size, ==, data); 1833 1834 if (zio != pio) 1835 zio_nowait(zio); 1836 } 1837 1838 static int 1839 zio_gang_assemble(zio_t *zio) 1840 { 1841 blkptr_t *bp = zio->io_bp; 1842 1843 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == NULL); 1844 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 1845 1846 zio->io_gang_leader = zio; 1847 1848 zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree); 1849 1850 return (ZIO_PIPELINE_CONTINUE); 1851 } 1852 1853 static int 1854 zio_gang_issue(zio_t *zio) 1855 { 1856 blkptr_t *bp = zio->io_bp; 1857 1858 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE)) 1859 return (ZIO_PIPELINE_STOP); 1860 1861 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio); 1862 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 1863 1864 if (zio->io_child_error[ZIO_CHILD_GANG] == 0) 1865 zio_gang_tree_issue(zio, zio->io_gang_tree, bp, zio->io_data); 1866 else 1867 zio_gang_tree_free(&zio->io_gang_tree); 1868 1869 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1870 1871 return (ZIO_PIPELINE_CONTINUE); 1872 } 1873 1874 static void 1875 zio_write_gang_member_ready(zio_t *zio) 1876 { 1877 zio_t *pio = zio_unique_parent(zio); 1878 zio_t *gio = zio->io_gang_leader; 1879 dva_t *cdva = zio->io_bp->blk_dva; 1880 dva_t *pdva = pio->io_bp->blk_dva; 1881 uint64_t asize; 1882 1883 if (BP_IS_HOLE(zio->io_bp)) 1884 return; 1885 1886 ASSERT(BP_IS_HOLE(&zio->io_bp_orig)); 1887 1888 ASSERT(zio->io_child_type == ZIO_CHILD_GANG); 1889 ASSERT3U(zio->io_prop.zp_copies, ==, gio->io_prop.zp_copies); 1890 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp)); 1891 ASSERT3U(pio->io_prop.zp_copies, <=, BP_GET_NDVAS(pio->io_bp)); 1892 ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp)); 1893 1894 mutex_enter(&pio->io_lock); 1895 for (int d = 0; d < BP_GET_NDVAS(zio->io_bp); d++) { 1896 ASSERT(DVA_GET_GANG(&pdva[d])); 1897 asize = DVA_GET_ASIZE(&pdva[d]); 1898 asize += DVA_GET_ASIZE(&cdva[d]); 1899 DVA_SET_ASIZE(&pdva[d], asize); 1900 } 1901 mutex_exit(&pio->io_lock); 1902 } 1903 1904 static int 1905 zio_write_gang_block(zio_t *pio) 1906 { 1907 spa_t *spa = pio->io_spa; 1908 blkptr_t *bp = pio->io_bp; 1909 zio_t *gio = pio->io_gang_leader; 1910 zio_t *zio; 1911 zio_gang_node_t *gn, **gnpp; 1912 zio_gbh_phys_t *gbh; 1913 uint64_t txg = pio->io_txg; 1914 uint64_t resid = pio->io_size; 1915 uint64_t lsize; 1916 int copies = gio->io_prop.zp_copies; 1917 int gbh_copies = MIN(copies + 1, spa_max_replication(spa)); 1918 zio_prop_t zp; 1919 int error; 1920 1921 error = metaslab_alloc(spa, spa_normal_class(spa), SPA_GANGBLOCKSIZE, 1922 bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp, 1923 METASLAB_HINTBP_FAVOR | METASLAB_GANG_HEADER); 1924 if (error) { 1925 pio->io_error = error; 1926 return (ZIO_PIPELINE_CONTINUE); 1927 } 1928 1929 if (pio == gio) { 1930 gnpp = &gio->io_gang_tree; 1931 } else { 1932 gnpp = pio->io_private; 1933 ASSERT(pio->io_ready == zio_write_gang_member_ready); 1934 } 1935 1936 gn = zio_gang_node_alloc(gnpp); 1937 gbh = gn->gn_gbh; 1938 bzero(gbh, SPA_GANGBLOCKSIZE); 1939 1940 /* 1941 * Create the gang header. 1942 */ 1943 zio = zio_rewrite(pio, spa, txg, bp, gbh, SPA_GANGBLOCKSIZE, NULL, NULL, 1944 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1945 1946 /* 1947 * Create and nowait the gang children. 1948 */ 1949 for (int g = 0; resid != 0; resid -= lsize, g++) { 1950 lsize = P2ROUNDUP(resid / (SPA_GBH_NBLKPTRS - g), 1951 SPA_MINBLOCKSIZE); 1952 ASSERT(lsize >= SPA_MINBLOCKSIZE && lsize <= resid); 1953 1954 zp.zp_checksum = gio->io_prop.zp_checksum; 1955 zp.zp_compress = ZIO_COMPRESS_OFF; 1956 zp.zp_type = DMU_OT_NONE; 1957 zp.zp_level = 0; 1958 zp.zp_copies = gio->io_prop.zp_copies; 1959 zp.zp_dedup = B_FALSE; 1960 zp.zp_dedup_verify = B_FALSE; 1961 zp.zp_nopwrite = B_FALSE; 1962 1963 zio_nowait(zio_write(zio, spa, txg, &gbh->zg_blkptr[g], 1964 (char *)pio->io_data + (pio->io_size - resid), lsize, &zp, 1965 zio_write_gang_member_ready, NULL, NULL, &gn->gn_child[g], 1966 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 1967 &pio->io_bookmark)); 1968 } 1969 1970 /* 1971 * Set pio's pipeline to just wait for zio to finish. 1972 */ 1973 pio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1974 1975 zio_nowait(zio); 1976 1977 return (ZIO_PIPELINE_CONTINUE); 1978 } 1979 1980 /* 1981 * The zio_nop_write stage in the pipeline determines if allocating 1982 * a new bp is necessary. By leveraging a cryptographically secure checksum, 1983 * such as SHA256, we can compare the checksums of the new data and the old 1984 * to determine if allocating a new block is required. The nopwrite 1985 * feature can handle writes in either syncing or open context (i.e. zil 1986 * writes) and as a result is mutually exclusive with dedup. 1987 */ 1988 static int 1989 zio_nop_write(zio_t *zio) 1990 { 1991 blkptr_t *bp = zio->io_bp; 1992 blkptr_t *bp_orig = &zio->io_bp_orig; 1993 zio_prop_t *zp = &zio->io_prop; 1994 1995 ASSERT(BP_GET_LEVEL(bp) == 0); 1996 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1997 ASSERT(zp->zp_nopwrite); 1998 ASSERT(!zp->zp_dedup); 1999 ASSERT(zio->io_bp_override == NULL); 2000 ASSERT(IO_IS_ALLOCATING(zio)); 2001 2002 /* 2003 * Check to see if the original bp and the new bp have matching 2004 * characteristics (i.e. same checksum, compression algorithms, etc). 2005 * If they don't then just continue with the pipeline which will 2006 * allocate a new bp. 2007 */ 2008 if (BP_IS_HOLE(bp_orig) || 2009 !zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_dedup || 2010 BP_GET_CHECKSUM(bp) != BP_GET_CHECKSUM(bp_orig) || 2011 BP_GET_COMPRESS(bp) != BP_GET_COMPRESS(bp_orig) || 2012 BP_GET_DEDUP(bp) != BP_GET_DEDUP(bp_orig) || 2013 zp->zp_copies != BP_GET_NDVAS(bp_orig)) 2014 return (ZIO_PIPELINE_CONTINUE); 2015 2016 /* 2017 * If the checksums match then reset the pipeline so that we 2018 * avoid allocating a new bp and issuing any I/O. 2019 */ 2020 if (ZIO_CHECKSUM_EQUAL(bp->blk_cksum, bp_orig->blk_cksum)) { 2021 ASSERT(zio_checksum_table[zp->zp_checksum].ci_dedup); 2022 ASSERT3U(BP_GET_PSIZE(bp), ==, BP_GET_PSIZE(bp_orig)); 2023 ASSERT3U(BP_GET_LSIZE(bp), ==, BP_GET_LSIZE(bp_orig)); 2024 ASSERT(zp->zp_compress != ZIO_COMPRESS_OFF); 2025 ASSERT(bcmp(&bp->blk_prop, &bp_orig->blk_prop, 2026 sizeof (uint64_t)) == 0); 2027 2028 *bp = *bp_orig; 2029 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2030 zio->io_flags |= ZIO_FLAG_NOPWRITE; 2031 } 2032 2033 return (ZIO_PIPELINE_CONTINUE); 2034 } 2035 2036 /* 2037 * ========================================================================== 2038 * Dedup 2039 * ========================================================================== 2040 */ 2041 static void 2042 zio_ddt_child_read_done(zio_t *zio) 2043 { 2044 blkptr_t *bp = zio->io_bp; 2045 ddt_entry_t *dde = zio->io_private; 2046 ddt_phys_t *ddp; 2047 zio_t *pio = zio_unique_parent(zio); 2048 2049 mutex_enter(&pio->io_lock); 2050 ddp = ddt_phys_select(dde, bp); 2051 if (zio->io_error == 0) 2052 ddt_phys_clear(ddp); /* this ddp doesn't need repair */ 2053 if (zio->io_error == 0 && dde->dde_repair_data == NULL) 2054 dde->dde_repair_data = zio->io_data; 2055 else 2056 zio_buf_free(zio->io_data, zio->io_size); 2057 mutex_exit(&pio->io_lock); 2058 } 2059 2060 static int 2061 zio_ddt_read_start(zio_t *zio) 2062 { 2063 blkptr_t *bp = zio->io_bp; 2064 2065 ASSERT(BP_GET_DEDUP(bp)); 2066 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 2067 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2068 2069 if (zio->io_child_error[ZIO_CHILD_DDT]) { 2070 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2071 ddt_entry_t *dde = ddt_repair_start(ddt, bp); 2072 ddt_phys_t *ddp = dde->dde_phys; 2073 ddt_phys_t *ddp_self = ddt_phys_select(dde, bp); 2074 blkptr_t blk; 2075 2076 ASSERT(zio->io_vsd == NULL); 2077 zio->io_vsd = dde; 2078 2079 if (ddp_self == NULL) 2080 return (ZIO_PIPELINE_CONTINUE); 2081 2082 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { 2083 if (ddp->ddp_phys_birth == 0 || ddp == ddp_self) 2084 continue; 2085 ddt_bp_create(ddt->ddt_checksum, &dde->dde_key, ddp, 2086 &blk); 2087 zio_nowait(zio_read(zio, zio->io_spa, &blk, 2088 zio_buf_alloc(zio->io_size), zio->io_size, 2089 zio_ddt_child_read_done, dde, zio->io_priority, 2090 ZIO_DDT_CHILD_FLAGS(zio) | ZIO_FLAG_DONT_PROPAGATE, 2091 &zio->io_bookmark)); 2092 } 2093 return (ZIO_PIPELINE_CONTINUE); 2094 } 2095 2096 zio_nowait(zio_read(zio, zio->io_spa, bp, 2097 zio->io_data, zio->io_size, NULL, NULL, zio->io_priority, 2098 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark)); 2099 2100 return (ZIO_PIPELINE_CONTINUE); 2101 } 2102 2103 static int 2104 zio_ddt_read_done(zio_t *zio) 2105 { 2106 blkptr_t *bp = zio->io_bp; 2107 2108 if (zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE)) 2109 return (ZIO_PIPELINE_STOP); 2110 2111 ASSERT(BP_GET_DEDUP(bp)); 2112 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 2113 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2114 2115 if (zio->io_child_error[ZIO_CHILD_DDT]) { 2116 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2117 ddt_entry_t *dde = zio->io_vsd; 2118 if (ddt == NULL) { 2119 ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE); 2120 return (ZIO_PIPELINE_CONTINUE); 2121 } 2122 if (dde == NULL) { 2123 zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1; 2124 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 2125 return (ZIO_PIPELINE_STOP); 2126 } 2127 if (dde->dde_repair_data != NULL) { 2128 bcopy(dde->dde_repair_data, zio->io_data, zio->io_size); 2129 zio->io_child_error[ZIO_CHILD_DDT] = 0; 2130 } 2131 ddt_repair_done(ddt, dde); 2132 zio->io_vsd = NULL; 2133 } 2134 2135 ASSERT(zio->io_vsd == NULL); 2136 2137 return (ZIO_PIPELINE_CONTINUE); 2138 } 2139 2140 static boolean_t 2141 zio_ddt_collision(zio_t *zio, ddt_t *ddt, ddt_entry_t *dde) 2142 { 2143 spa_t *spa = zio->io_spa; 2144 2145 /* 2146 * Note: we compare the original data, not the transformed data, 2147 * because when zio->io_bp is an override bp, we will not have 2148 * pushed the I/O transforms. That's an important optimization 2149 * because otherwise we'd compress/encrypt all dmu_sync() data twice. 2150 */ 2151 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 2152 zio_t *lio = dde->dde_lead_zio[p]; 2153 2154 if (lio != NULL) { 2155 return (lio->io_orig_size != zio->io_orig_size || 2156 bcmp(zio->io_orig_data, lio->io_orig_data, 2157 zio->io_orig_size) != 0); 2158 } 2159 } 2160 2161 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 2162 ddt_phys_t *ddp = &dde->dde_phys[p]; 2163 2164 if (ddp->ddp_phys_birth != 0) { 2165 arc_buf_t *abuf = NULL; 2166 arc_flags_t aflags = ARC_FLAG_WAIT; 2167 blkptr_t blk = *zio->io_bp; 2168 int error; 2169 2170 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth); 2171 2172 ddt_exit(ddt); 2173 2174 error = arc_read(NULL, spa, &blk, 2175 arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ, 2176 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, 2177 &aflags, &zio->io_bookmark); 2178 2179 if (error == 0) { 2180 if (arc_buf_size(abuf) != zio->io_orig_size || 2181 bcmp(abuf->b_data, zio->io_orig_data, 2182 zio->io_orig_size) != 0) 2183 error = SET_ERROR(EEXIST); 2184 VERIFY(arc_buf_remove_ref(abuf, &abuf)); 2185 } 2186 2187 ddt_enter(ddt); 2188 return (error != 0); 2189 } 2190 } 2191 2192 return (B_FALSE); 2193 } 2194 2195 static void 2196 zio_ddt_child_write_ready(zio_t *zio) 2197 { 2198 int p = zio->io_prop.zp_copies; 2199 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 2200 ddt_entry_t *dde = zio->io_private; 2201 ddt_phys_t *ddp = &dde->dde_phys[p]; 2202 zio_t *pio; 2203 2204 if (zio->io_error) 2205 return; 2206 2207 ddt_enter(ddt); 2208 2209 ASSERT(dde->dde_lead_zio[p] == zio); 2210 2211 ddt_phys_fill(ddp, zio->io_bp); 2212 2213 while ((pio = zio_walk_parents(zio)) != NULL) 2214 ddt_bp_fill(ddp, pio->io_bp, zio->io_txg); 2215 2216 ddt_exit(ddt); 2217 } 2218 2219 static void 2220 zio_ddt_child_write_done(zio_t *zio) 2221 { 2222 int p = zio->io_prop.zp_copies; 2223 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 2224 ddt_entry_t *dde = zio->io_private; 2225 ddt_phys_t *ddp = &dde->dde_phys[p]; 2226 2227 ddt_enter(ddt); 2228 2229 ASSERT(ddp->ddp_refcnt == 0); 2230 ASSERT(dde->dde_lead_zio[p] == zio); 2231 dde->dde_lead_zio[p] = NULL; 2232 2233 if (zio->io_error == 0) { 2234 while (zio_walk_parents(zio) != NULL) 2235 ddt_phys_addref(ddp); 2236 } else { 2237 ddt_phys_clear(ddp); 2238 } 2239 2240 ddt_exit(ddt); 2241 } 2242 2243 static void 2244 zio_ddt_ditto_write_done(zio_t *zio) 2245 { 2246 int p = DDT_PHYS_DITTO; 2247 zio_prop_t *zp = &zio->io_prop; 2248 blkptr_t *bp = zio->io_bp; 2249 ddt_t *ddt = ddt_select(zio->io_spa, bp); 2250 ddt_entry_t *dde = zio->io_private; 2251 ddt_phys_t *ddp = &dde->dde_phys[p]; 2252 ddt_key_t *ddk = &dde->dde_key; 2253 2254 ddt_enter(ddt); 2255 2256 ASSERT(ddp->ddp_refcnt == 0); 2257 ASSERT(dde->dde_lead_zio[p] == zio); 2258 dde->dde_lead_zio[p] = NULL; 2259 2260 if (zio->io_error == 0) { 2261 ASSERT(ZIO_CHECKSUM_EQUAL(bp->blk_cksum, ddk->ddk_cksum)); 2262 ASSERT(zp->zp_copies < SPA_DVAS_PER_BP); 2263 ASSERT(zp->zp_copies == BP_GET_NDVAS(bp) - BP_IS_GANG(bp)); 2264 if (ddp->ddp_phys_birth != 0) 2265 ddt_phys_free(ddt, ddk, ddp, zio->io_txg); 2266 ddt_phys_fill(ddp, bp); 2267 } 2268 2269 ddt_exit(ddt); 2270 } 2271 2272 static int 2273 zio_ddt_write(zio_t *zio) 2274 { 2275 spa_t *spa = zio->io_spa; 2276 blkptr_t *bp = zio->io_bp; 2277 uint64_t txg = zio->io_txg; 2278 zio_prop_t *zp = &zio->io_prop; 2279 int p = zp->zp_copies; 2280 int ditto_copies; 2281 zio_t *cio = NULL; 2282 zio_t *dio = NULL; 2283 ddt_t *ddt = ddt_select(spa, bp); 2284 ddt_entry_t *dde; 2285 ddt_phys_t *ddp; 2286 2287 ASSERT(BP_GET_DEDUP(bp)); 2288 ASSERT(BP_GET_CHECKSUM(bp) == zp->zp_checksum); 2289 ASSERT(BP_IS_HOLE(bp) || zio->io_bp_override); 2290 2291 ddt_enter(ddt); 2292 dde = ddt_lookup(ddt, bp, B_TRUE); 2293 ddp = &dde->dde_phys[p]; 2294 2295 if (zp->zp_dedup_verify && zio_ddt_collision(zio, ddt, dde)) { 2296 /* 2297 * If we're using a weak checksum, upgrade to a strong checksum 2298 * and try again. If we're already using a strong checksum, 2299 * we can't resolve it, so just convert to an ordinary write. 2300 * (And automatically e-mail a paper to Nature?) 2301 */ 2302 if (!zio_checksum_table[zp->zp_checksum].ci_dedup) { 2303 zp->zp_checksum = spa_dedup_checksum(spa); 2304 zio_pop_transforms(zio); 2305 zio->io_stage = ZIO_STAGE_OPEN; 2306 BP_ZERO(bp); 2307 } else { 2308 zp->zp_dedup = B_FALSE; 2309 } 2310 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2311 ddt_exit(ddt); 2312 return (ZIO_PIPELINE_CONTINUE); 2313 } 2314 2315 ditto_copies = ddt_ditto_copies_needed(ddt, dde, ddp); 2316 ASSERT(ditto_copies < SPA_DVAS_PER_BP); 2317 2318 if (ditto_copies > ddt_ditto_copies_present(dde) && 2319 dde->dde_lead_zio[DDT_PHYS_DITTO] == NULL) { 2320 zio_prop_t czp = *zp; 2321 2322 czp.zp_copies = ditto_copies; 2323 2324 /* 2325 * If we arrived here with an override bp, we won't have run 2326 * the transform stack, so we won't have the data we need to 2327 * generate a child i/o. So, toss the override bp and restart. 2328 * This is safe, because using the override bp is just an 2329 * optimization; and it's rare, so the cost doesn't matter. 2330 */ 2331 if (zio->io_bp_override) { 2332 zio_pop_transforms(zio); 2333 zio->io_stage = ZIO_STAGE_OPEN; 2334 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2335 zio->io_bp_override = NULL; 2336 BP_ZERO(bp); 2337 ddt_exit(ddt); 2338 return (ZIO_PIPELINE_CONTINUE); 2339 } 2340 2341 dio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2342 zio->io_orig_size, &czp, NULL, NULL, 2343 zio_ddt_ditto_write_done, dde, zio->io_priority, 2344 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2345 2346 zio_push_transform(dio, zio->io_data, zio->io_size, 0, NULL); 2347 dde->dde_lead_zio[DDT_PHYS_DITTO] = dio; 2348 } 2349 2350 if (ddp->ddp_phys_birth != 0 || dde->dde_lead_zio[p] != NULL) { 2351 if (ddp->ddp_phys_birth != 0) 2352 ddt_bp_fill(ddp, bp, txg); 2353 if (dde->dde_lead_zio[p] != NULL) 2354 zio_add_child(zio, dde->dde_lead_zio[p]); 2355 else 2356 ddt_phys_addref(ddp); 2357 } else if (zio->io_bp_override) { 2358 ASSERT(bp->blk_birth == txg); 2359 ASSERT(BP_EQUAL(bp, zio->io_bp_override)); 2360 ddt_phys_fill(ddp, bp); 2361 ddt_phys_addref(ddp); 2362 } else { 2363 cio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2364 zio->io_orig_size, zp, zio_ddt_child_write_ready, NULL, 2365 zio_ddt_child_write_done, dde, zio->io_priority, 2366 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2367 2368 zio_push_transform(cio, zio->io_data, zio->io_size, 0, NULL); 2369 dde->dde_lead_zio[p] = cio; 2370 } 2371 2372 ddt_exit(ddt); 2373 2374 if (cio) 2375 zio_nowait(cio); 2376 if (dio) 2377 zio_nowait(dio); 2378 2379 return (ZIO_PIPELINE_CONTINUE); 2380 } 2381 2382 ddt_entry_t *freedde; /* for debugging */ 2383 2384 static int 2385 zio_ddt_free(zio_t *zio) 2386 { 2387 spa_t *spa = zio->io_spa; 2388 blkptr_t *bp = zio->io_bp; 2389 ddt_t *ddt = ddt_select(spa, bp); 2390 ddt_entry_t *dde; 2391 ddt_phys_t *ddp; 2392 2393 ASSERT(BP_GET_DEDUP(bp)); 2394 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2395 2396 ddt_enter(ddt); 2397 freedde = dde = ddt_lookup(ddt, bp, B_TRUE); 2398 ddp = ddt_phys_select(dde, bp); 2399 ddt_phys_decref(ddp); 2400 ddt_exit(ddt); 2401 2402 return (ZIO_PIPELINE_CONTINUE); 2403 } 2404 2405 /* 2406 * ========================================================================== 2407 * Allocate and free blocks 2408 * ========================================================================== 2409 */ 2410 static int 2411 zio_dva_allocate(zio_t *zio) 2412 { 2413 spa_t *spa = zio->io_spa; 2414 metaslab_class_t *mc = spa_normal_class(spa); 2415 blkptr_t *bp = zio->io_bp; 2416 int error; 2417 int flags = 0; 2418 2419 if (zio->io_gang_leader == NULL) { 2420 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2421 zio->io_gang_leader = zio; 2422 } 2423 2424 ASSERT(BP_IS_HOLE(bp)); 2425 ASSERT0(BP_GET_NDVAS(bp)); 2426 ASSERT3U(zio->io_prop.zp_copies, >, 0); 2427 ASSERT3U(zio->io_prop.zp_copies, <=, spa_max_replication(spa)); 2428 ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp)); 2429 2430 /* 2431 * The dump device does not support gang blocks so allocation on 2432 * behalf of the dump device (i.e. ZIO_FLAG_NODATA) must avoid 2433 * the "fast" gang feature. 2434 */ 2435 flags |= (zio->io_flags & ZIO_FLAG_NODATA) ? METASLAB_GANG_AVOID : 0; 2436 flags |= (zio->io_flags & ZIO_FLAG_GANG_CHILD) ? 2437 METASLAB_GANG_CHILD : 0; 2438 error = metaslab_alloc(spa, mc, zio->io_size, bp, 2439 zio->io_prop.zp_copies, zio->io_txg, NULL, flags); 2440 2441 if (error) { 2442 spa_dbgmsg(spa, "%s: metaslab allocation failure: zio %p, " 2443 "size %llu, error %d", spa_name(spa), zio, zio->io_size, 2444 error); 2445 if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE) 2446 return (zio_write_gang_block(zio)); 2447 zio->io_error = error; 2448 } 2449 2450 return (ZIO_PIPELINE_CONTINUE); 2451 } 2452 2453 static int 2454 zio_dva_free(zio_t *zio) 2455 { 2456 metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE); 2457 2458 return (ZIO_PIPELINE_CONTINUE); 2459 } 2460 2461 static int 2462 zio_dva_claim(zio_t *zio) 2463 { 2464 int error; 2465 2466 error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg); 2467 if (error) 2468 zio->io_error = error; 2469 2470 return (ZIO_PIPELINE_CONTINUE); 2471 } 2472 2473 /* 2474 * Undo an allocation. This is used by zio_done() when an I/O fails 2475 * and we want to give back the block we just allocated. 2476 * This handles both normal blocks and gang blocks. 2477 */ 2478 static void 2479 zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp) 2480 { 2481 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp)); 2482 ASSERT(zio->io_bp_override == NULL); 2483 2484 if (!BP_IS_HOLE(bp)) 2485 metaslab_free(zio->io_spa, bp, bp->blk_birth, B_TRUE); 2486 2487 if (gn != NULL) { 2488 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 2489 zio_dva_unallocate(zio, gn->gn_child[g], 2490 &gn->gn_gbh->zg_blkptr[g]); 2491 } 2492 } 2493 } 2494 2495 /* 2496 * Try to allocate an intent log block. Return 0 on success, errno on failure. 2497 */ 2498 int 2499 zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp, blkptr_t *old_bp, 2500 uint64_t size, boolean_t use_slog) 2501 { 2502 int error = 1; 2503 2504 ASSERT(txg > spa_syncing_txg(spa)); 2505 2506 /* 2507 * ZIL blocks are always contiguous (i.e. not gang blocks) so we 2508 * set the METASLAB_GANG_AVOID flag so that they don't "fast gang" 2509 * when allocating them. 2510 */ 2511 if (use_slog) { 2512 error = metaslab_alloc(spa, spa_log_class(spa), size, 2513 new_bp, 1, txg, old_bp, 2514 METASLAB_HINTBP_AVOID | METASLAB_GANG_AVOID); 2515 } 2516 2517 if (error) { 2518 error = metaslab_alloc(spa, spa_normal_class(spa), size, 2519 new_bp, 1, txg, old_bp, 2520 METASLAB_HINTBP_AVOID); 2521 } 2522 2523 if (error == 0) { 2524 BP_SET_LSIZE(new_bp, size); 2525 BP_SET_PSIZE(new_bp, size); 2526 BP_SET_COMPRESS(new_bp, ZIO_COMPRESS_OFF); 2527 BP_SET_CHECKSUM(new_bp, 2528 spa_version(spa) >= SPA_VERSION_SLIM_ZIL 2529 ? ZIO_CHECKSUM_ZILOG2 : ZIO_CHECKSUM_ZILOG); 2530 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG); 2531 BP_SET_LEVEL(new_bp, 0); 2532 BP_SET_DEDUP(new_bp, 0); 2533 BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER); 2534 } 2535 2536 return (error); 2537 } 2538 2539 /* 2540 * Free an intent log block. 2541 */ 2542 void 2543 zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp) 2544 { 2545 ASSERT(BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG); 2546 ASSERT(!BP_IS_GANG(bp)); 2547 2548 zio_free(spa, txg, bp); 2549 } 2550 2551 /* 2552 * ========================================================================== 2553 * Read and write to physical devices 2554 * ========================================================================== 2555 */ 2556 2557 2558 /* 2559 * Issue an I/O to the underlying vdev. Typically the issue pipeline 2560 * stops after this stage and will resume upon I/O completion. 2561 * However, there are instances where the vdev layer may need to 2562 * continue the pipeline when an I/O was not issued. Since the I/O 2563 * that was sent to the vdev layer might be different than the one 2564 * currently active in the pipeline (see vdev_queue_io()), we explicitly 2565 * force the underlying vdev layers to call either zio_execute() or 2566 * zio_interrupt() to ensure that the pipeline continues with the correct I/O. 2567 */ 2568 static int 2569 zio_vdev_io_start(zio_t *zio) 2570 { 2571 vdev_t *vd = zio->io_vd; 2572 uint64_t align; 2573 spa_t *spa = zio->io_spa; 2574 2575 ASSERT(zio->io_error == 0); 2576 ASSERT(zio->io_child_error[ZIO_CHILD_VDEV] == 0); 2577 2578 if (vd == NULL) { 2579 if (!(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 2580 spa_config_enter(spa, SCL_ZIO, zio, RW_READER); 2581 2582 /* 2583 * The mirror_ops handle multiple DVAs in a single BP. 2584 */ 2585 vdev_mirror_ops.vdev_op_io_start(zio); 2586 return (ZIO_PIPELINE_STOP); 2587 } 2588 2589 /* 2590 * We keep track of time-sensitive I/Os so that the scan thread 2591 * can quickly react to certain workloads. In particular, we care 2592 * about non-scrubbing, top-level reads and writes with the following 2593 * characteristics: 2594 * - synchronous writes of user data to non-slog devices 2595 * - any reads of user data 2596 * When these conditions are met, adjust the timestamp of spa_last_io 2597 * which allows the scan thread to adjust its workload accordingly. 2598 */ 2599 if (!(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && zio->io_bp != NULL && 2600 vd == vd->vdev_top && !vd->vdev_islog && 2601 zio->io_bookmark.zb_objset != DMU_META_OBJSET && 2602 zio->io_txg != spa_syncing_txg(spa)) { 2603 uint64_t old = spa->spa_last_io; 2604 uint64_t new = ddi_get_lbolt64(); 2605 if (old != new) 2606 (void) atomic_cas_64(&spa->spa_last_io, old, new); 2607 } 2608 2609 align = 1ULL << vd->vdev_top->vdev_ashift; 2610 2611 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL) && 2612 P2PHASE(zio->io_size, align) != 0) { 2613 /* Transform logical writes to be a full physical block size. */ 2614 uint64_t asize = P2ROUNDUP(zio->io_size, align); 2615 char *abuf = zio_buf_alloc(asize); 2616 ASSERT(vd == vd->vdev_top); 2617 if (zio->io_type == ZIO_TYPE_WRITE) { 2618 bcopy(zio->io_data, abuf, zio->io_size); 2619 bzero(abuf + zio->io_size, asize - zio->io_size); 2620 } 2621 zio_push_transform(zio, abuf, asize, asize, zio_subblock); 2622 } 2623 2624 /* 2625 * If this is not a physical io, make sure that it is properly aligned 2626 * before proceeding. 2627 */ 2628 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL)) { 2629 ASSERT0(P2PHASE(zio->io_offset, align)); 2630 ASSERT0(P2PHASE(zio->io_size, align)); 2631 } else { 2632 /* 2633 * For physical writes, we allow 512b aligned writes and assume 2634 * the device will perform a read-modify-write as necessary. 2635 */ 2636 ASSERT0(P2PHASE(zio->io_offset, SPA_MINBLOCKSIZE)); 2637 ASSERT0(P2PHASE(zio->io_size, SPA_MINBLOCKSIZE)); 2638 } 2639 2640 VERIFY(zio->io_type != ZIO_TYPE_WRITE || spa_writeable(spa)); 2641 2642 /* 2643 * If this is a repair I/O, and there's no self-healing involved -- 2644 * that is, we're just resilvering what we expect to resilver -- 2645 * then don't do the I/O unless zio's txg is actually in vd's DTL. 2646 * This prevents spurious resilvering with nested replication. 2647 * For example, given a mirror of mirrors, (A+B)+(C+D), if only 2648 * A is out of date, we'll read from C+D, then use the data to 2649 * resilver A+B -- but we don't actually want to resilver B, just A. 2650 * The top-level mirror has no way to know this, so instead we just 2651 * discard unnecessary repairs as we work our way down the vdev tree. 2652 * The same logic applies to any form of nested replication: 2653 * ditto + mirror, RAID-Z + replacing, etc. This covers them all. 2654 */ 2655 if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) && 2656 !(zio->io_flags & ZIO_FLAG_SELF_HEAL) && 2657 zio->io_txg != 0 && /* not a delegated i/o */ 2658 !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) { 2659 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 2660 zio_vdev_io_bypass(zio); 2661 return (ZIO_PIPELINE_CONTINUE); 2662 } 2663 2664 if (vd->vdev_ops->vdev_op_leaf && 2665 (zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE)) { 2666 2667 if (zio->io_type == ZIO_TYPE_READ && vdev_cache_read(zio)) 2668 return (ZIO_PIPELINE_CONTINUE); 2669 2670 if ((zio = vdev_queue_io(zio)) == NULL) 2671 return (ZIO_PIPELINE_STOP); 2672 2673 if (!vdev_accessible(vd, zio)) { 2674 zio->io_error = SET_ERROR(ENXIO); 2675 zio_interrupt(zio); 2676 return (ZIO_PIPELINE_STOP); 2677 } 2678 } 2679 2680 vd->vdev_ops->vdev_op_io_start(zio); 2681 return (ZIO_PIPELINE_STOP); 2682 } 2683 2684 static int 2685 zio_vdev_io_done(zio_t *zio) 2686 { 2687 vdev_t *vd = zio->io_vd; 2688 vdev_ops_t *ops = vd ? vd->vdev_ops : &vdev_mirror_ops; 2689 boolean_t unexpected_error = B_FALSE; 2690 2691 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 2692 return (ZIO_PIPELINE_STOP); 2693 2694 ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE); 2695 2696 if (vd != NULL && vd->vdev_ops->vdev_op_leaf) { 2697 2698 vdev_queue_io_done(zio); 2699 2700 if (zio->io_type == ZIO_TYPE_WRITE) 2701 vdev_cache_write(zio); 2702 2703 if (zio_injection_enabled && zio->io_error == 0) 2704 zio->io_error = zio_handle_device_injection(vd, 2705 zio, EIO); 2706 2707 if (zio_injection_enabled && zio->io_error == 0) 2708 zio->io_error = zio_handle_label_injection(zio, EIO); 2709 2710 if (zio->io_error) { 2711 if (!vdev_accessible(vd, zio)) { 2712 zio->io_error = SET_ERROR(ENXIO); 2713 } else { 2714 unexpected_error = B_TRUE; 2715 } 2716 } 2717 } 2718 2719 ops->vdev_op_io_done(zio); 2720 2721 if (unexpected_error) 2722 VERIFY(vdev_probe(vd, zio) == NULL); 2723 2724 return (ZIO_PIPELINE_CONTINUE); 2725 } 2726 2727 /* 2728 * For non-raidz ZIOs, we can just copy aside the bad data read from the 2729 * disk, and use that to finish the checksum ereport later. 2730 */ 2731 static void 2732 zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr, 2733 const void *good_buf) 2734 { 2735 /* no processing needed */ 2736 zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE); 2737 } 2738 2739 /*ARGSUSED*/ 2740 void 2741 zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *ignored) 2742 { 2743 void *buf = zio_buf_alloc(zio->io_size); 2744 2745 bcopy(zio->io_data, buf, zio->io_size); 2746 2747 zcr->zcr_cbinfo = zio->io_size; 2748 zcr->zcr_cbdata = buf; 2749 zcr->zcr_finish = zio_vsd_default_cksum_finish; 2750 zcr->zcr_free = zio_buf_free; 2751 } 2752 2753 static int 2754 zio_vdev_io_assess(zio_t *zio) 2755 { 2756 vdev_t *vd = zio->io_vd; 2757 2758 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 2759 return (ZIO_PIPELINE_STOP); 2760 2761 if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 2762 spa_config_exit(zio->io_spa, SCL_ZIO, zio); 2763 2764 if (zio->io_vsd != NULL) { 2765 zio->io_vsd_ops->vsd_free(zio); 2766 zio->io_vsd = NULL; 2767 } 2768 2769 if (zio_injection_enabled && zio->io_error == 0) 2770 zio->io_error = zio_handle_fault_injection(zio, EIO); 2771 2772 /* 2773 * If the I/O failed, determine whether we should attempt to retry it. 2774 * 2775 * On retry, we cut in line in the issue queue, since we don't want 2776 * compression/checksumming/etc. work to prevent our (cheap) IO reissue. 2777 */ 2778 if (zio->io_error && vd == NULL && 2779 !(zio->io_flags & (ZIO_FLAG_DONT_RETRY | ZIO_FLAG_IO_RETRY))) { 2780 ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_QUEUE)); /* not a leaf */ 2781 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_BYPASS)); /* not a leaf */ 2782 zio->io_error = 0; 2783 zio->io_flags |= ZIO_FLAG_IO_RETRY | 2784 ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE; 2785 zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1; 2786 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, 2787 zio_requeue_io_start_cut_in_line); 2788 return (ZIO_PIPELINE_STOP); 2789 } 2790 2791 /* 2792 * If we got an error on a leaf device, convert it to ENXIO 2793 * if the device is not accessible at all. 2794 */ 2795 if (zio->io_error && vd != NULL && vd->vdev_ops->vdev_op_leaf && 2796 !vdev_accessible(vd, zio)) 2797 zio->io_error = SET_ERROR(ENXIO); 2798 2799 /* 2800 * If we can't write to an interior vdev (mirror or RAID-Z), 2801 * set vdev_cant_write so that we stop trying to allocate from it. 2802 */ 2803 if (zio->io_error == ENXIO && zio->io_type == ZIO_TYPE_WRITE && 2804 vd != NULL && !vd->vdev_ops->vdev_op_leaf) { 2805 vd->vdev_cant_write = B_TRUE; 2806 } 2807 2808 if (zio->io_error) 2809 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2810 2811 if (vd != NULL && vd->vdev_ops->vdev_op_leaf && 2812 zio->io_physdone != NULL) { 2813 ASSERT(!(zio->io_flags & ZIO_FLAG_DELEGATED)); 2814 ASSERT(zio->io_child_type == ZIO_CHILD_VDEV); 2815 zio->io_physdone(zio->io_logical); 2816 } 2817 2818 return (ZIO_PIPELINE_CONTINUE); 2819 } 2820 2821 void 2822 zio_vdev_io_reissue(zio_t *zio) 2823 { 2824 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 2825 ASSERT(zio->io_error == 0); 2826 2827 zio->io_stage >>= 1; 2828 } 2829 2830 void 2831 zio_vdev_io_redone(zio_t *zio) 2832 { 2833 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE); 2834 2835 zio->io_stage >>= 1; 2836 } 2837 2838 void 2839 zio_vdev_io_bypass(zio_t *zio) 2840 { 2841 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 2842 ASSERT(zio->io_error == 0); 2843 2844 zio->io_flags |= ZIO_FLAG_IO_BYPASS; 2845 zio->io_stage = ZIO_STAGE_VDEV_IO_ASSESS >> 1; 2846 } 2847 2848 /* 2849 * ========================================================================== 2850 * Generate and verify checksums 2851 * ========================================================================== 2852 */ 2853 static int 2854 zio_checksum_generate(zio_t *zio) 2855 { 2856 blkptr_t *bp = zio->io_bp; 2857 enum zio_checksum checksum; 2858 2859 if (bp == NULL) { 2860 /* 2861 * This is zio_write_phys(). 2862 * We're either generating a label checksum, or none at all. 2863 */ 2864 checksum = zio->io_prop.zp_checksum; 2865 2866 if (checksum == ZIO_CHECKSUM_OFF) 2867 return (ZIO_PIPELINE_CONTINUE); 2868 2869 ASSERT(checksum == ZIO_CHECKSUM_LABEL); 2870 } else { 2871 if (BP_IS_GANG(bp) && zio->io_child_type == ZIO_CHILD_GANG) { 2872 ASSERT(!IO_IS_ALLOCATING(zio)); 2873 checksum = ZIO_CHECKSUM_GANG_HEADER; 2874 } else { 2875 checksum = BP_GET_CHECKSUM(bp); 2876 } 2877 } 2878 2879 zio_checksum_compute(zio, checksum, zio->io_data, zio->io_size); 2880 2881 return (ZIO_PIPELINE_CONTINUE); 2882 } 2883 2884 static int 2885 zio_checksum_verify(zio_t *zio) 2886 { 2887 zio_bad_cksum_t info; 2888 blkptr_t *bp = zio->io_bp; 2889 int error; 2890 2891 ASSERT(zio->io_vd != NULL); 2892 2893 if (bp == NULL) { 2894 /* 2895 * This is zio_read_phys(). 2896 * We're either verifying a label checksum, or nothing at all. 2897 */ 2898 if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF) 2899 return (ZIO_PIPELINE_CONTINUE); 2900 2901 ASSERT(zio->io_prop.zp_checksum == ZIO_CHECKSUM_LABEL); 2902 } 2903 2904 if ((error = zio_checksum_error(zio, &info)) != 0) { 2905 zio->io_error = error; 2906 if (error == ECKSUM && 2907 !(zio->io_flags & ZIO_FLAG_SPECULATIVE)) { 2908 zfs_ereport_start_checksum(zio->io_spa, 2909 zio->io_vd, zio, zio->io_offset, 2910 zio->io_size, NULL, &info); 2911 } 2912 } 2913 2914 return (ZIO_PIPELINE_CONTINUE); 2915 } 2916 2917 /* 2918 * Called by RAID-Z to ensure we don't compute the checksum twice. 2919 */ 2920 void 2921 zio_checksum_verified(zio_t *zio) 2922 { 2923 zio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 2924 } 2925 2926 /* 2927 * ========================================================================== 2928 * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other. 2929 * An error of 0 indicates success. ENXIO indicates whole-device failure, 2930 * which may be transient (e.g. unplugged) or permament. ECKSUM and EIO 2931 * indicate errors that are specific to one I/O, and most likely permanent. 2932 * Any other error is presumed to be worse because we weren't expecting it. 2933 * ========================================================================== 2934 */ 2935 int 2936 zio_worst_error(int e1, int e2) 2937 { 2938 static int zio_error_rank[] = { 0, ENXIO, ECKSUM, EIO }; 2939 int r1, r2; 2940 2941 for (r1 = 0; r1 < sizeof (zio_error_rank) / sizeof (int); r1++) 2942 if (e1 == zio_error_rank[r1]) 2943 break; 2944 2945 for (r2 = 0; r2 < sizeof (zio_error_rank) / sizeof (int); r2++) 2946 if (e2 == zio_error_rank[r2]) 2947 break; 2948 2949 return (r1 > r2 ? e1 : e2); 2950 } 2951 2952 /* 2953 * ========================================================================== 2954 * I/O completion 2955 * ========================================================================== 2956 */ 2957 static int 2958 zio_ready(zio_t *zio) 2959 { 2960 blkptr_t *bp = zio->io_bp; 2961 zio_t *pio, *pio_next; 2962 2963 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 2964 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_READY)) 2965 return (ZIO_PIPELINE_STOP); 2966 2967 if (zio->io_ready) { 2968 ASSERT(IO_IS_ALLOCATING(zio)); 2969 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp) || 2970 (zio->io_flags & ZIO_FLAG_NOPWRITE)); 2971 ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0); 2972 2973 zio->io_ready(zio); 2974 } 2975 2976 if (bp != NULL && bp != &zio->io_bp_copy) 2977 zio->io_bp_copy = *bp; 2978 2979 if (zio->io_error) 2980 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2981 2982 mutex_enter(&zio->io_lock); 2983 zio->io_state[ZIO_WAIT_READY] = 1; 2984 pio = zio_walk_parents(zio); 2985 mutex_exit(&zio->io_lock); 2986 2987 /* 2988 * As we notify zio's parents, new parents could be added. 2989 * New parents go to the head of zio's io_parent_list, however, 2990 * so we will (correctly) not notify them. The remainder of zio's 2991 * io_parent_list, from 'pio_next' onward, cannot change because 2992 * all parents must wait for us to be done before they can be done. 2993 */ 2994 for (; pio != NULL; pio = pio_next) { 2995 pio_next = zio_walk_parents(zio); 2996 zio_notify_parent(pio, zio, ZIO_WAIT_READY); 2997 } 2998 2999 if (zio->io_flags & ZIO_FLAG_NODATA) { 3000 if (BP_IS_GANG(bp)) { 3001 zio->io_flags &= ~ZIO_FLAG_NODATA; 3002 } else { 3003 ASSERT((uintptr_t)zio->io_data < SPA_MAXBLOCKSIZE); 3004 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 3005 } 3006 } 3007 3008 if (zio_injection_enabled && 3009 zio->io_spa->spa_syncing_txg == zio->io_txg) 3010 zio_handle_ignored_writes(zio); 3011 3012 return (ZIO_PIPELINE_CONTINUE); 3013 } 3014 3015 static int 3016 zio_done(zio_t *zio) 3017 { 3018 spa_t *spa = zio->io_spa; 3019 zio_t *lio = zio->io_logical; 3020 blkptr_t *bp = zio->io_bp; 3021 vdev_t *vd = zio->io_vd; 3022 uint64_t psize = zio->io_size; 3023 zio_t *pio, *pio_next; 3024 3025 /* 3026 * If our children haven't all completed, 3027 * wait for them and then repeat this pipeline stage. 3028 */ 3029 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE) || 3030 zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE) || 3031 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE) || 3032 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_DONE)) 3033 return (ZIO_PIPELINE_STOP); 3034 3035 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 3036 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 3037 ASSERT(zio->io_children[c][w] == 0); 3038 3039 if (bp != NULL && !BP_IS_EMBEDDED(bp)) { 3040 ASSERT(bp->blk_pad[0] == 0); 3041 ASSERT(bp->blk_pad[1] == 0); 3042 ASSERT(bcmp(bp, &zio->io_bp_copy, sizeof (blkptr_t)) == 0 || 3043 (bp == zio_unique_parent(zio)->io_bp)); 3044 if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(bp) && 3045 zio->io_bp_override == NULL && 3046 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) { 3047 ASSERT(!BP_SHOULD_BYTESWAP(bp)); 3048 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(bp)); 3049 ASSERT(BP_COUNT_GANG(bp) == 0 || 3050 (BP_COUNT_GANG(bp) == BP_GET_NDVAS(bp))); 3051 } 3052 if (zio->io_flags & ZIO_FLAG_NOPWRITE) 3053 VERIFY(BP_EQUAL(bp, &zio->io_bp_orig)); 3054 } 3055 3056 /* 3057 * If there were child vdev/gang/ddt errors, they apply to us now. 3058 */ 3059 zio_inherit_child_errors(zio, ZIO_CHILD_VDEV); 3060 zio_inherit_child_errors(zio, ZIO_CHILD_GANG); 3061 zio_inherit_child_errors(zio, ZIO_CHILD_DDT); 3062 3063 /* 3064 * If the I/O on the transformed data was successful, generate any 3065 * checksum reports now while we still have the transformed data. 3066 */ 3067 if (zio->io_error == 0) { 3068 while (zio->io_cksum_report != NULL) { 3069 zio_cksum_report_t *zcr = zio->io_cksum_report; 3070 uint64_t align = zcr->zcr_align; 3071 uint64_t asize = P2ROUNDUP(psize, align); 3072 char *abuf = zio->io_data; 3073 3074 if (asize != psize) { 3075 abuf = zio_buf_alloc(asize); 3076 bcopy(zio->io_data, abuf, psize); 3077 bzero(abuf + psize, asize - psize); 3078 } 3079 3080 zio->io_cksum_report = zcr->zcr_next; 3081 zcr->zcr_next = NULL; 3082 zcr->zcr_finish(zcr, abuf); 3083 zfs_ereport_free_checksum(zcr); 3084 3085 if (asize != psize) 3086 zio_buf_free(abuf, asize); 3087 } 3088 } 3089 3090 zio_pop_transforms(zio); /* note: may set zio->io_error */ 3091 3092 vdev_stat_update(zio, psize); 3093 3094 if (zio->io_error) { 3095 /* 3096 * If this I/O is attached to a particular vdev, 3097 * generate an error message describing the I/O failure 3098 * at the block level. We ignore these errors if the 3099 * device is currently unavailable. 3100 */ 3101 if (zio->io_error != ECKSUM && vd != NULL && !vdev_is_dead(vd)) 3102 zfs_ereport_post(FM_EREPORT_ZFS_IO, spa, vd, zio, 0, 0); 3103 3104 if ((zio->io_error == EIO || !(zio->io_flags & 3105 (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) && 3106 zio == lio) { 3107 /* 3108 * For logical I/O requests, tell the SPA to log the 3109 * error and generate a logical data ereport. 3110 */ 3111 spa_log_error(spa, zio); 3112 zfs_ereport_post(FM_EREPORT_ZFS_DATA, spa, NULL, zio, 3113 0, 0); 3114 } 3115 } 3116 3117 if (zio->io_error && zio == lio) { 3118 /* 3119 * Determine whether zio should be reexecuted. This will 3120 * propagate all the way to the root via zio_notify_parent(). 3121 */ 3122 ASSERT(vd == NULL && bp != NULL); 3123 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3124 3125 if (IO_IS_ALLOCATING(zio) && 3126 !(zio->io_flags & ZIO_FLAG_CANFAIL)) { 3127 if (zio->io_error != ENOSPC) 3128 zio->io_reexecute |= ZIO_REEXECUTE_NOW; 3129 else 3130 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3131 } 3132 3133 if ((zio->io_type == ZIO_TYPE_READ || 3134 zio->io_type == ZIO_TYPE_FREE) && 3135 !(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && 3136 zio->io_error == ENXIO && 3137 spa_load_state(spa) == SPA_LOAD_NONE && 3138 spa_get_failmode(spa) != ZIO_FAILURE_MODE_CONTINUE) 3139 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3140 3141 if (!(zio->io_flags & ZIO_FLAG_CANFAIL) && !zio->io_reexecute) 3142 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 3143 3144 /* 3145 * Here is a possibly good place to attempt to do 3146 * either combinatorial reconstruction or error correction 3147 * based on checksums. It also might be a good place 3148 * to send out preliminary ereports before we suspend 3149 * processing. 3150 */ 3151 } 3152 3153 /* 3154 * If there were logical child errors, they apply to us now. 3155 * We defer this until now to avoid conflating logical child 3156 * errors with errors that happened to the zio itself when 3157 * updating vdev stats and reporting FMA events above. 3158 */ 3159 zio_inherit_child_errors(zio, ZIO_CHILD_LOGICAL); 3160 3161 if ((zio->io_error || zio->io_reexecute) && 3162 IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio && 3163 !(zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE))) 3164 zio_dva_unallocate(zio, zio->io_gang_tree, bp); 3165 3166 zio_gang_tree_free(&zio->io_gang_tree); 3167 3168 /* 3169 * Godfather I/Os should never suspend. 3170 */ 3171 if ((zio->io_flags & ZIO_FLAG_GODFATHER) && 3172 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) 3173 zio->io_reexecute = 0; 3174 3175 if (zio->io_reexecute) { 3176 /* 3177 * This is a logical I/O that wants to reexecute. 3178 * 3179 * Reexecute is top-down. When an i/o fails, if it's not 3180 * the root, it simply notifies its parent and sticks around. 3181 * The parent, seeing that it still has children in zio_done(), 3182 * does the same. This percolates all the way up to the root. 3183 * The root i/o will reexecute or suspend the entire tree. 3184 * 3185 * This approach ensures that zio_reexecute() honors 3186 * all the original i/o dependency relationships, e.g. 3187 * parents not executing until children are ready. 3188 */ 3189 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3190 3191 zio->io_gang_leader = NULL; 3192 3193 mutex_enter(&zio->io_lock); 3194 zio->io_state[ZIO_WAIT_DONE] = 1; 3195 mutex_exit(&zio->io_lock); 3196 3197 /* 3198 * "The Godfather" I/O monitors its children but is 3199 * not a true parent to them. It will track them through 3200 * the pipeline but severs its ties whenever they get into 3201 * trouble (e.g. suspended). This allows "The Godfather" 3202 * I/O to return status without blocking. 3203 */ 3204 for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) { 3205 zio_link_t *zl = zio->io_walk_link; 3206 pio_next = zio_walk_parents(zio); 3207 3208 if ((pio->io_flags & ZIO_FLAG_GODFATHER) && 3209 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) { 3210 zio_remove_child(pio, zio, zl); 3211 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3212 } 3213 } 3214 3215 if ((pio = zio_unique_parent(zio)) != NULL) { 3216 /* 3217 * We're not a root i/o, so there's nothing to do 3218 * but notify our parent. Don't propagate errors 3219 * upward since we haven't permanently failed yet. 3220 */ 3221 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 3222 zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE; 3223 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3224 } else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) { 3225 /* 3226 * We'd fail again if we reexecuted now, so suspend 3227 * until conditions improve (e.g. device comes online). 3228 */ 3229 zio_suspend(spa, zio); 3230 } else { 3231 /* 3232 * Reexecution is potentially a huge amount of work. 3233 * Hand it off to the otherwise-unused claim taskq. 3234 */ 3235 ASSERT(zio->io_tqent.tqent_next == NULL); 3236 spa_taskq_dispatch_ent(spa, ZIO_TYPE_CLAIM, 3237 ZIO_TASKQ_ISSUE, (task_func_t *)zio_reexecute, zio, 3238 0, &zio->io_tqent); 3239 } 3240 return (ZIO_PIPELINE_STOP); 3241 } 3242 3243 ASSERT(zio->io_child_count == 0); 3244 ASSERT(zio->io_reexecute == 0); 3245 ASSERT(zio->io_error == 0 || (zio->io_flags & ZIO_FLAG_CANFAIL)); 3246 3247 /* 3248 * Report any checksum errors, since the I/O is complete. 3249 */ 3250 while (zio->io_cksum_report != NULL) { 3251 zio_cksum_report_t *zcr = zio->io_cksum_report; 3252 zio->io_cksum_report = zcr->zcr_next; 3253 zcr->zcr_next = NULL; 3254 zcr->zcr_finish(zcr, NULL); 3255 zfs_ereport_free_checksum(zcr); 3256 } 3257 3258 /* 3259 * It is the responsibility of the done callback to ensure that this 3260 * particular zio is no longer discoverable for adoption, and as 3261 * such, cannot acquire any new parents. 3262 */ 3263 if (zio->io_done) 3264 zio->io_done(zio); 3265 3266 mutex_enter(&zio->io_lock); 3267 zio->io_state[ZIO_WAIT_DONE] = 1; 3268 mutex_exit(&zio->io_lock); 3269 3270 for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) { 3271 zio_link_t *zl = zio->io_walk_link; 3272 pio_next = zio_walk_parents(zio); 3273 zio_remove_child(pio, zio, zl); 3274 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 3275 } 3276 3277 if (zio->io_waiter != NULL) { 3278 mutex_enter(&zio->io_lock); 3279 zio->io_executor = NULL; 3280 cv_broadcast(&zio->io_cv); 3281 mutex_exit(&zio->io_lock); 3282 } else { 3283 zio_destroy(zio); 3284 } 3285 3286 return (ZIO_PIPELINE_STOP); 3287 } 3288 3289 /* 3290 * ========================================================================== 3291 * I/O pipeline definition 3292 * ========================================================================== 3293 */ 3294 static zio_pipe_stage_t *zio_pipeline[] = { 3295 NULL, 3296 zio_read_bp_init, 3297 zio_free_bp_init, 3298 zio_issue_async, 3299 zio_write_bp_init, 3300 zio_checksum_generate, 3301 zio_nop_write, 3302 zio_ddt_read_start, 3303 zio_ddt_read_done, 3304 zio_ddt_write, 3305 zio_ddt_free, 3306 zio_gang_assemble, 3307 zio_gang_issue, 3308 zio_dva_allocate, 3309 zio_dva_free, 3310 zio_dva_claim, 3311 zio_ready, 3312 zio_vdev_io_start, 3313 zio_vdev_io_done, 3314 zio_vdev_io_assess, 3315 zio_checksum_verify, 3316 zio_done 3317 }; 3318 3319 /* dnp is the dnode for zb1->zb_object */ 3320 boolean_t 3321 zbookmark_is_before(const dnode_phys_t *dnp, const zbookmark_phys_t *zb1, 3322 const zbookmark_phys_t *zb2) 3323 { 3324 uint64_t zb1nextL0, zb2thisobj; 3325 3326 ASSERT(zb1->zb_objset == zb2->zb_objset); 3327 ASSERT(zb2->zb_level == 0); 3328 3329 /* The objset_phys_t isn't before anything. */ 3330 if (dnp == NULL) 3331 return (B_FALSE); 3332 3333 zb1nextL0 = (zb1->zb_blkid + 1) << 3334 ((zb1->zb_level) * (dnp->dn_indblkshift - SPA_BLKPTRSHIFT)); 3335 3336 zb2thisobj = zb2->zb_object ? zb2->zb_object : 3337 zb2->zb_blkid << (DNODE_BLOCK_SHIFT - DNODE_SHIFT); 3338 3339 if (zb1->zb_object == DMU_META_DNODE_OBJECT) { 3340 uint64_t nextobj = zb1nextL0 * 3341 (dnp->dn_datablkszsec << SPA_MINBLOCKSHIFT) >> DNODE_SHIFT; 3342 return (nextobj <= zb2thisobj); 3343 } 3344 3345 if (zb1->zb_object < zb2thisobj) 3346 return (B_TRUE); 3347 if (zb1->zb_object > zb2thisobj) 3348 return (B_FALSE); 3349 if (zb2->zb_object == DMU_META_DNODE_OBJECT) 3350 return (B_FALSE); 3351 return (zb1nextL0 <= zb2->zb_blkid); 3352 } 3353