246} 247 248void 249zio_buf_free(void *buf, size_t size) 250{ 251 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 252 253 ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 254 255 if (zio_use_uma) 256 kmem_cache_free(zio_buf_cache[c], buf); 257 else 258 kmem_free(buf, size); 259} 260 261void 262zio_data_buf_free(void *buf, size_t size) 263{ 264 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 265 266 ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 267 268 if (zio_use_uma) 269 kmem_cache_free(zio_data_buf_cache[c], buf); 270 else 271 kmem_free(buf, size); 272} 273 274/* 275 * ========================================================================== 276 * Push and pop I/O transform buffers 277 * ========================================================================== 278 */ 279static void 280zio_push_transform(zio_t *zio, void *data, uint64_t size, uint64_t bufsize, 281 zio_transform_func_t *transform) 282{ 283 zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP); 284 285 zt->zt_orig_data = zio->io_data; 286 zt->zt_orig_size = zio->io_size; 287 zt->zt_bufsize = bufsize; 288 zt->zt_transform = transform; 289 290 zt->zt_next = zio->io_transform_stack; 291 zio->io_transform_stack = zt; 292 293 zio->io_data = data; 294 zio->io_size = size; 295} 296 297static void 298zio_pop_transforms(zio_t *zio) 299{ 300 zio_transform_t *zt; 301 302 while ((zt = zio->io_transform_stack) != NULL) { 303 if (zt->zt_transform != NULL) 304 zt->zt_transform(zio, 305 zt->zt_orig_data, zt->zt_orig_size); 306 307 if (zt->zt_bufsize != 0) 308 zio_buf_free(zio->io_data, zt->zt_bufsize); 309 310 zio->io_data = zt->zt_orig_data; 311 zio->io_size = zt->zt_orig_size; 312 zio->io_transform_stack = zt->zt_next; 313 314 kmem_free(zt, sizeof (zio_transform_t)); 315 } 316} 317 318/* 319 * ========================================================================== 320 * I/O transform callbacks for subblocks and decompression 321 * ========================================================================== 322 */ 323static void 324zio_subblock(zio_t *zio, void *data, uint64_t size) 325{ 326 ASSERT(zio->io_size > size); 327 328 if (zio->io_type == ZIO_TYPE_READ) 329 bcopy(zio->io_data, data, size); 330} 331 332static void 333zio_decompress(zio_t *zio, void *data, uint64_t size) 334{ 335 if (zio->io_error == 0 && 336 zio_decompress_data(BP_GET_COMPRESS(zio->io_bp), 337 zio->io_data, data, zio->io_size, size) != 0) 338 zio->io_error = EIO; 339} 340 341/* 342 * ========================================================================== 343 * I/O parent/child relationships and pipeline interlocks 344 * ========================================================================== 345 */ 346/* 347 * NOTE - Callers to zio_walk_parents() and zio_walk_children must 348 * continue calling these functions until they return NULL. 349 * Otherwise, the next caller will pick up the list walk in 350 * some indeterminate state. (Otherwise every caller would 351 * have to pass in a cookie to keep the state represented by 352 * io_walk_link, which gets annoying.) 353 */ 354zio_t * 355zio_walk_parents(zio_t *cio) 356{ 357 zio_link_t *zl = cio->io_walk_link; 358 list_t *pl = &cio->io_parent_list; 359 360 zl = (zl == NULL) ? list_head(pl) : list_next(pl, zl); 361 cio->io_walk_link = zl; 362 363 if (zl == NULL) 364 return (NULL); 365 366 ASSERT(zl->zl_child == cio); 367 return (zl->zl_parent); 368} 369 370zio_t * 371zio_walk_children(zio_t *pio) 372{ 373 zio_link_t *zl = pio->io_walk_link; 374 list_t *cl = &pio->io_child_list; 375 376 zl = (zl == NULL) ? list_head(cl) : list_next(cl, zl); 377 pio->io_walk_link = zl; 378 379 if (zl == NULL) 380 return (NULL); 381 382 ASSERT(zl->zl_parent == pio); 383 return (zl->zl_child); 384} 385 386zio_t * 387zio_unique_parent(zio_t *cio) 388{ 389 zio_t *pio = zio_walk_parents(cio); 390 391 VERIFY(zio_walk_parents(cio) == NULL); 392 return (pio); 393} 394 395void 396zio_add_child(zio_t *pio, zio_t *cio) 397{ 398 zio_link_t *zl = kmem_cache_alloc(zio_link_cache, KM_SLEEP); 399 400 /* 401 * Logical I/Os can have logical, gang, or vdev children. 402 * Gang I/Os can have gang or vdev children. 403 * Vdev I/Os can only have vdev children. 404 * The following ASSERT captures all of these constraints. 405 */ 406 ASSERT(cio->io_child_type <= pio->io_child_type); 407 408 zl->zl_parent = pio; 409 zl->zl_child = cio; 410 411 mutex_enter(&cio->io_lock); 412 mutex_enter(&pio->io_lock); 413 414 ASSERT(pio->io_state[ZIO_WAIT_DONE] == 0); 415 416 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 417 pio->io_children[cio->io_child_type][w] += !cio->io_state[w]; 418 419 list_insert_head(&pio->io_child_list, zl); 420 list_insert_head(&cio->io_parent_list, zl); 421 422 pio->io_child_count++; 423 cio->io_parent_count++; 424 425 mutex_exit(&pio->io_lock); 426 mutex_exit(&cio->io_lock); 427} 428 429static void 430zio_remove_child(zio_t *pio, zio_t *cio, zio_link_t *zl) 431{ 432 ASSERT(zl->zl_parent == pio); 433 ASSERT(zl->zl_child == cio); 434 435 mutex_enter(&cio->io_lock); 436 mutex_enter(&pio->io_lock); 437 438 list_remove(&pio->io_child_list, zl); 439 list_remove(&cio->io_parent_list, zl); 440 441 pio->io_child_count--; 442 cio->io_parent_count--; 443 444 mutex_exit(&pio->io_lock); 445 mutex_exit(&cio->io_lock); 446 447 kmem_cache_free(zio_link_cache, zl); 448} 449 450static boolean_t 451zio_wait_for_children(zio_t *zio, enum zio_child child, enum zio_wait_type wait) 452{ 453 uint64_t *countp = &zio->io_children[child][wait]; 454 boolean_t waiting = B_FALSE; 455 456 mutex_enter(&zio->io_lock); 457 ASSERT(zio->io_stall == NULL); 458 if (*countp != 0) { 459 zio->io_stage >>= 1; 460 zio->io_stall = countp; 461 waiting = B_TRUE; 462 } 463 mutex_exit(&zio->io_lock); 464 465 return (waiting); 466} 467 468static void 469zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait) 470{ 471 uint64_t *countp = &pio->io_children[zio->io_child_type][wait]; 472 int *errorp = &pio->io_child_error[zio->io_child_type]; 473 474 mutex_enter(&pio->io_lock); 475 if (zio->io_error && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE)) 476 *errorp = zio_worst_error(*errorp, zio->io_error); 477 pio->io_reexecute |= zio->io_reexecute; 478 ASSERT3U(*countp, >, 0); 479 if (--*countp == 0 && pio->io_stall == countp) { 480 pio->io_stall = NULL; 481 mutex_exit(&pio->io_lock); 482 zio_execute(pio); 483 } else { 484 mutex_exit(&pio->io_lock); 485 } 486} 487 488static void 489zio_inherit_child_errors(zio_t *zio, enum zio_child c) 490{ 491 if (zio->io_child_error[c] != 0 && zio->io_error == 0) 492 zio->io_error = zio->io_child_error[c]; 493} 494 495/* 496 * ========================================================================== 497 * Create the various types of I/O (read, write, free, etc) 498 * ========================================================================== 499 */ 500static zio_t * 501zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 502 void *data, uint64_t size, zio_done_func_t *done, void *private, 503 zio_type_t type, int priority, enum zio_flag flags, 504 vdev_t *vd, uint64_t offset, const zbookmark_t *zb, 505 enum zio_stage stage, enum zio_stage pipeline) 506{ 507 zio_t *zio; 508 509 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 510 ASSERT(P2PHASE(size, SPA_MINBLOCKSIZE) == 0); 511 ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0); 512 513 ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER)); 514 ASSERT(!bp || !(flags & ZIO_FLAG_CONFIG_WRITER)); 515 ASSERT(vd || stage == ZIO_STAGE_OPEN); 516 517 zio = kmem_cache_alloc(zio_cache, KM_SLEEP); 518 bzero(zio, sizeof (zio_t)); 519 520 mutex_init(&zio->io_lock, NULL, MUTEX_DEFAULT, NULL); 521 cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL); 522 523 list_create(&zio->io_parent_list, sizeof (zio_link_t), 524 offsetof(zio_link_t, zl_parent_node)); 525 list_create(&zio->io_child_list, sizeof (zio_link_t), 526 offsetof(zio_link_t, zl_child_node)); 527 528 if (vd != NULL) 529 zio->io_child_type = ZIO_CHILD_VDEV; 530 else if (flags & ZIO_FLAG_GANG_CHILD) 531 zio->io_child_type = ZIO_CHILD_GANG; 532 else if (flags & ZIO_FLAG_DDT_CHILD) 533 zio->io_child_type = ZIO_CHILD_DDT; 534 else 535 zio->io_child_type = ZIO_CHILD_LOGICAL; 536 537 if (bp != NULL) { 538 zio->io_bp = (blkptr_t *)bp; 539 zio->io_bp_copy = *bp; 540 zio->io_bp_orig = *bp; 541 if (type != ZIO_TYPE_WRITE || 542 zio->io_child_type == ZIO_CHILD_DDT) 543 zio->io_bp = &zio->io_bp_copy; /* so caller can free */ 544 if (zio->io_child_type == ZIO_CHILD_LOGICAL) 545 zio->io_logical = zio; 546 if (zio->io_child_type > ZIO_CHILD_GANG && BP_IS_GANG(bp)) 547 pipeline |= ZIO_GANG_STAGES; 548 } 549 550 zio->io_spa = spa; 551 zio->io_txg = txg; 552 zio->io_done = done; 553 zio->io_private = private; 554 zio->io_type = type; 555 zio->io_priority = priority; 556 zio->io_vd = vd; 557 zio->io_offset = offset; 558 zio->io_orig_data = zio->io_data = data; 559 zio->io_orig_size = zio->io_size = size; 560 zio->io_orig_flags = zio->io_flags = flags; 561 zio->io_orig_stage = zio->io_stage = stage; 562 zio->io_orig_pipeline = zio->io_pipeline = pipeline; 563 564 zio->io_state[ZIO_WAIT_READY] = (stage >= ZIO_STAGE_READY); 565 zio->io_state[ZIO_WAIT_DONE] = (stage >= ZIO_STAGE_DONE); 566 567 if (zb != NULL) 568 zio->io_bookmark = *zb; 569 570 if (pio != NULL) { 571 if (zio->io_logical == NULL) 572 zio->io_logical = pio->io_logical; 573 if (zio->io_child_type == ZIO_CHILD_GANG) 574 zio->io_gang_leader = pio->io_gang_leader; 575 zio_add_child(pio, zio); 576 } 577 578 return (zio); 579} 580 581static void 582zio_destroy(zio_t *zio) 583{ 584 list_destroy(&zio->io_parent_list); 585 list_destroy(&zio->io_child_list); 586 mutex_destroy(&zio->io_lock); 587 cv_destroy(&zio->io_cv); 588 kmem_cache_free(zio_cache, zio); 589} 590 591zio_t * 592zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, zio_done_func_t *done, 593 void *private, enum zio_flag flags) 594{ 595 zio_t *zio; 596 597 zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private, 598 ZIO_TYPE_NULL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL, 599 ZIO_STAGE_OPEN, ZIO_INTERLOCK_PIPELINE); 600 601 return (zio); 602} 603 604zio_t * 605zio_root(spa_t *spa, zio_done_func_t *done, void *private, enum zio_flag flags) 606{ 607 return (zio_null(NULL, spa, NULL, done, private, flags)); 608} 609 610zio_t * 611zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, 612 void *data, uint64_t size, zio_done_func_t *done, void *private, 613 int priority, enum zio_flag flags, const zbookmark_t *zb) 614{ 615 zio_t *zio; 616 617 zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp, 618 data, size, done, private, 619 ZIO_TYPE_READ, priority, flags, NULL, 0, zb, 620 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 621 ZIO_DDT_CHILD_READ_PIPELINE : ZIO_READ_PIPELINE); 622 623 return (zio); 624} 625 626zio_t * 627zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, 628 void *data, uint64_t size, const zio_prop_t *zp, 629 zio_done_func_t *ready, zio_done_func_t *done, void *private, 630 int priority, enum zio_flag flags, const zbookmark_t *zb) 631{ 632 zio_t *zio; 633 634 ASSERT(zp->zp_checksum >= ZIO_CHECKSUM_OFF && 635 zp->zp_checksum < ZIO_CHECKSUM_FUNCTIONS && 636 zp->zp_compress >= ZIO_COMPRESS_OFF && 637 zp->zp_compress < ZIO_COMPRESS_FUNCTIONS && 638 zp->zp_type < DMU_OT_NUMTYPES && 639 zp->zp_level < 32 && 640 zp->zp_copies > 0 && 641 zp->zp_copies <= spa_max_replication(spa) && 642 zp->zp_dedup <= 1 && 643 zp->zp_dedup_verify <= 1); 644 645 zio = zio_create(pio, spa, txg, bp, data, size, done, private, 646 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 647 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 648 ZIO_DDT_CHILD_WRITE_PIPELINE : ZIO_WRITE_PIPELINE); 649 650 zio->io_ready = ready; 651 zio->io_prop = *zp; 652 653 return (zio); 654} 655 656zio_t * 657zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, void *data, 658 uint64_t size, zio_done_func_t *done, void *private, int priority, 659 enum zio_flag flags, zbookmark_t *zb) 660{ 661 zio_t *zio; 662 663 zio = zio_create(pio, spa, txg, bp, data, size, done, private, 664 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 665 ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE); 666 667 return (zio); 668} 669 670void 671zio_write_override(zio_t *zio, blkptr_t *bp, int copies) 672{ 673 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 674 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 675 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 676 ASSERT(zio->io_txg == spa_syncing_txg(zio->io_spa)); 677 678 zio->io_prop.zp_copies = copies; 679 zio->io_bp_override = bp; 680} 681 682void 683zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp) 684{ 685 bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp); 686} 687 688zio_t * 689zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 690 enum zio_flag flags) 691{ 692 zio_t *zio; 693 694 dprintf_bp(bp, "freeing in txg %llu, pass %u", 695 (longlong_t)txg, spa->spa_sync_pass); 696 697 ASSERT(!BP_IS_HOLE(bp)); 698 ASSERT(spa_syncing_txg(spa) == txg); 699 ASSERT(spa_sync_pass(spa) <= SYNC_PASS_DEFERRED_FREE); 700 701 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 702 NULL, NULL, ZIO_TYPE_FREE, ZIO_PRIORITY_FREE, flags, 703 NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_FREE_PIPELINE); 704 705 return (zio); 706} 707 708zio_t * 709zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 710 zio_done_func_t *done, void *private, enum zio_flag flags) 711{ 712 zio_t *zio; 713 714 /* 715 * A claim is an allocation of a specific block. Claims are needed 716 * to support immediate writes in the intent log. The issue is that 717 * immediate writes contain committed data, but in a txg that was 718 * *not* committed. Upon opening the pool after an unclean shutdown, 719 * the intent log claims all blocks that contain immediate write data 720 * so that the SPA knows they're in use. 721 * 722 * All claims *must* be resolved in the first txg -- before the SPA 723 * starts allocating blocks -- so that nothing is allocated twice. 724 * If txg == 0 we just verify that the block is claimable. 725 */ 726 ASSERT3U(spa->spa_uberblock.ub_rootbp.blk_birth, <, spa_first_txg(spa)); 727 ASSERT(txg == spa_first_txg(spa) || txg == 0); 728 ASSERT(!BP_GET_DEDUP(bp) || !spa_writeable(spa)); /* zdb(1M) */ 729 730 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 731 done, private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW, flags, 732 NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE); 733 734 return (zio); 735} 736 737zio_t * 738zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd, 739 zio_done_func_t *done, void *private, int priority, enum zio_flag flags) 740{ 741 zio_t *zio; 742 int c; 743 744 if (vd->vdev_children == 0) { 745 zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private, 746 ZIO_TYPE_IOCTL, priority, flags, vd, 0, NULL, 747 ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE); 748 749 zio->io_cmd = cmd; 750 } else { 751 zio = zio_null(pio, spa, NULL, NULL, NULL, flags); 752 753 for (c = 0; c < vd->vdev_children; c++) 754 zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd, 755 done, private, priority, flags)); 756 } 757 758 return (zio); 759} 760 761zio_t * 762zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 763 void *data, int checksum, zio_done_func_t *done, void *private, 764 int priority, enum zio_flag flags, boolean_t labels) 765{ 766 zio_t *zio; 767 768 ASSERT(vd->vdev_children == 0); 769 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 770 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 771 ASSERT3U(offset + size, <=, vd->vdev_psize); 772 773 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private, 774 ZIO_TYPE_READ, priority, flags, vd, offset, NULL, 775 ZIO_STAGE_OPEN, ZIO_READ_PHYS_PIPELINE); 776 777 zio->io_prop.zp_checksum = checksum; 778 779 return (zio); 780} 781 782zio_t * 783zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 784 void *data, int checksum, zio_done_func_t *done, void *private, 785 int priority, enum zio_flag flags, boolean_t labels) 786{ 787 zio_t *zio; 788 789 ASSERT(vd->vdev_children == 0); 790 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 791 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 792 ASSERT3U(offset + size, <=, vd->vdev_psize); 793 794 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private, 795 ZIO_TYPE_WRITE, priority, flags, vd, offset, NULL, 796 ZIO_STAGE_OPEN, ZIO_WRITE_PHYS_PIPELINE); 797 798 zio->io_prop.zp_checksum = checksum; 799 800 if (zio_checksum_table[checksum].ci_eck) { 801 /* 802 * zec checksums are necessarily destructive -- they modify 803 * the end of the write buffer to hold the verifier/checksum. 804 * Therefore, we must make a local copy in case the data is 805 * being written to multiple places in parallel. 806 */ 807 void *wbuf = zio_buf_alloc(size); 808 bcopy(data, wbuf, size); 809 zio_push_transform(zio, wbuf, size, size, NULL); 810 } 811 812 return (zio); 813} 814 815/* 816 * Create a child I/O to do some work for us. 817 */ 818zio_t * 819zio_vdev_child_io(zio_t *pio, blkptr_t *bp, vdev_t *vd, uint64_t offset, 820 void *data, uint64_t size, int type, int priority, enum zio_flag flags, 821 zio_done_func_t *done, void *private) 822{ 823 enum zio_stage pipeline = ZIO_VDEV_CHILD_PIPELINE; 824 zio_t *zio; 825 826 ASSERT(vd->vdev_parent == 827 (pio->io_vd ? pio->io_vd : pio->io_spa->spa_root_vdev)); 828 829 if (type == ZIO_TYPE_READ && bp != NULL) { 830 /* 831 * If we have the bp, then the child should perform the 832 * checksum and the parent need not. This pushes error 833 * detection as close to the leaves as possible and 834 * eliminates redundant checksums in the interior nodes. 835 */ 836 pipeline |= ZIO_STAGE_CHECKSUM_VERIFY; 837 pio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 838 } 839 840 if (vd->vdev_children == 0) 841 offset += VDEV_LABEL_START_SIZE; 842 843 flags |= ZIO_VDEV_CHILD_FLAGS(pio) | ZIO_FLAG_DONT_PROPAGATE; 844 845 /* 846 * If we've decided to do a repair, the write is not speculative -- 847 * even if the original read was. 848 */ 849 if (flags & ZIO_FLAG_IO_REPAIR) 850 flags &= ~ZIO_FLAG_SPECULATIVE; 851 852 zio = zio_create(pio, pio->io_spa, pio->io_txg, bp, data, size, 853 done, private, type, priority, flags, vd, offset, &pio->io_bookmark, 854 ZIO_STAGE_VDEV_IO_START >> 1, pipeline); 855 856 return (zio); 857} 858 859zio_t * 860zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, void *data, uint64_t size, 861 int type, int priority, enum zio_flag flags, 862 zio_done_func_t *done, void *private) 863{ 864 zio_t *zio; 865 866 ASSERT(vd->vdev_ops->vdev_op_leaf); 867 868 zio = zio_create(NULL, vd->vdev_spa, 0, NULL, 869 data, size, done, private, type, priority, 870 flags | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY, 871 vd, offset, NULL, 872 ZIO_STAGE_VDEV_IO_START >> 1, ZIO_VDEV_CHILD_PIPELINE); 873 874 return (zio); 875} 876 877void 878zio_flush(zio_t *zio, vdev_t *vd) 879{ 880 zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE, 881 NULL, NULL, ZIO_PRIORITY_NOW, 882 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY)); 883} 884 885void 886zio_shrink(zio_t *zio, uint64_t size) 887{ 888 ASSERT(zio->io_executor == NULL); 889 ASSERT(zio->io_orig_size == zio->io_size); 890 ASSERT(size <= zio->io_size); 891 892 /* 893 * We don't shrink for raidz because of problems with the 894 * reconstruction when reading back less than the block size. 895 * Note, BP_IS_RAIDZ() assumes no compression. 896 */ 897 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 898 if (!BP_IS_RAIDZ(zio->io_bp)) 899 zio->io_orig_size = zio->io_size = size; 900} 901 902/* 903 * ========================================================================== 904 * Prepare to read and write logical blocks 905 * ========================================================================== 906 */ 907 908static int 909zio_read_bp_init(zio_t *zio) 910{ 911 blkptr_t *bp = zio->io_bp; 912 913 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF && 914 zio->io_child_type == ZIO_CHILD_LOGICAL && 915 !(zio->io_flags & ZIO_FLAG_RAW)) { 916 uint64_t psize = BP_GET_PSIZE(bp); 917 void *cbuf = zio_buf_alloc(psize); 918 919 zio_push_transform(zio, cbuf, psize, psize, zio_decompress); 920 } 921 922 if (!dmu_ot[BP_GET_TYPE(bp)].ot_metadata && BP_GET_LEVEL(bp) == 0) 923 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 924 925 if (BP_GET_TYPE(bp) == DMU_OT_DDT_ZAP) 926 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 927 928 if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL) 929 zio->io_pipeline = ZIO_DDT_READ_PIPELINE; 930 931 return (ZIO_PIPELINE_CONTINUE); 932} 933 934static int 935zio_write_bp_init(zio_t *zio) 936{ 937 spa_t *spa = zio->io_spa; 938 zio_prop_t *zp = &zio->io_prop; 939 enum zio_compress compress = zp->zp_compress; 940 blkptr_t *bp = zio->io_bp; 941 uint64_t lsize = zio->io_size; 942 uint64_t psize = lsize; 943 int pass = 1; 944 945 /* 946 * If our children haven't all reached the ready stage, 947 * wait for them and then repeat this pipeline stage. 948 */ 949 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 950 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_READY)) 951 return (ZIO_PIPELINE_STOP); 952 953 if (!IO_IS_ALLOCATING(zio)) 954 return (ZIO_PIPELINE_CONTINUE); 955 956 ASSERT(zio->io_child_type != ZIO_CHILD_DDT); 957 958 if (zio->io_bp_override) { 959 ASSERT(bp->blk_birth != zio->io_txg); 960 ASSERT(BP_GET_DEDUP(zio->io_bp_override) == 0); 961 962 *bp = *zio->io_bp_override; 963 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 964 965 if (BP_IS_HOLE(bp) || !zp->zp_dedup) 966 return (ZIO_PIPELINE_CONTINUE); 967 968 ASSERT(zio_checksum_table[zp->zp_checksum].ci_dedup || 969 zp->zp_dedup_verify); 970 971 if (BP_GET_CHECKSUM(bp) == zp->zp_checksum) { 972 BP_SET_DEDUP(bp, 1); 973 zio->io_pipeline |= ZIO_STAGE_DDT_WRITE; 974 return (ZIO_PIPELINE_CONTINUE); 975 } 976 zio->io_bp_override = NULL; 977 BP_ZERO(bp); 978 } 979 980 if (bp->blk_birth == zio->io_txg) { 981 /* 982 * We're rewriting an existing block, which means we're 983 * working on behalf of spa_sync(). For spa_sync() to 984 * converge, it must eventually be the case that we don't 985 * have to allocate new blocks. But compression changes 986 * the blocksize, which forces a reallocate, and makes 987 * convergence take longer. Therefore, after the first 988 * few passes, stop compressing to ensure convergence. 989 */ 990 pass = spa_sync_pass(spa); 991 992 ASSERT(zio->io_txg == spa_syncing_txg(spa)); 993 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 994 ASSERT(!BP_GET_DEDUP(bp)); 995 996 if (pass > SYNC_PASS_DONT_COMPRESS) 997 compress = ZIO_COMPRESS_OFF; 998 999 /* Make sure someone doesn't change their mind on overwrites */ 1000 ASSERT(MIN(zp->zp_copies + BP_IS_GANG(bp), 1001 spa_max_replication(spa)) == BP_GET_NDVAS(bp)); 1002 } 1003 1004 if (compress != ZIO_COMPRESS_OFF) { 1005 void *cbuf = zio_buf_alloc(lsize); 1006 psize = zio_compress_data(compress, zio->io_data, cbuf, lsize); 1007 if (psize == 0 || psize == lsize) { 1008 compress = ZIO_COMPRESS_OFF; 1009 zio_buf_free(cbuf, lsize); 1010 } else { 1011 ASSERT(psize < lsize); 1012 zio_push_transform(zio, cbuf, psize, lsize, NULL); 1013 } 1014 } 1015 1016 /* 1017 * The final pass of spa_sync() must be all rewrites, but the first 1018 * few passes offer a trade-off: allocating blocks defers convergence, 1019 * but newly allocated blocks are sequential, so they can be written 1020 * to disk faster. Therefore, we allow the first few passes of 1021 * spa_sync() to allocate new blocks, but force rewrites after that. 1022 * There should only be a handful of blocks after pass 1 in any case. 1023 */ 1024 if (bp->blk_birth == zio->io_txg && BP_GET_PSIZE(bp) == psize && 1025 pass > SYNC_PASS_REWRITE) { 1026 ASSERT(psize != 0); 1027 enum zio_stage gang_stages = zio->io_pipeline & ZIO_GANG_STAGES; 1028 zio->io_pipeline = ZIO_REWRITE_PIPELINE | gang_stages; 1029 zio->io_flags |= ZIO_FLAG_IO_REWRITE; 1030 } else { 1031 BP_ZERO(bp); 1032 zio->io_pipeline = ZIO_WRITE_PIPELINE; 1033 } 1034 1035 if (psize == 0) { 1036 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1037 } else { 1038 ASSERT(zp->zp_checksum != ZIO_CHECKSUM_GANG_HEADER); 1039 BP_SET_LSIZE(bp, lsize); 1040 BP_SET_PSIZE(bp, psize); 1041 BP_SET_COMPRESS(bp, compress); 1042 BP_SET_CHECKSUM(bp, zp->zp_checksum); 1043 BP_SET_TYPE(bp, zp->zp_type); 1044 BP_SET_LEVEL(bp, zp->zp_level); 1045 BP_SET_DEDUP(bp, zp->zp_dedup); 1046 BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER); 1047 if (zp->zp_dedup) { 1048 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1049 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1050 zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE; 1051 } 1052 } 1053 1054 return (ZIO_PIPELINE_CONTINUE); 1055} 1056 1057static int 1058zio_free_bp_init(zio_t *zio) 1059{ 1060 blkptr_t *bp = zio->io_bp; 1061 1062 if (zio->io_child_type == ZIO_CHILD_LOGICAL) { 1063 if (BP_GET_DEDUP(bp)) 1064 zio->io_pipeline = ZIO_DDT_FREE_PIPELINE; 1065 } 1066 1067 return (ZIO_PIPELINE_CONTINUE); 1068} 1069 1070/* 1071 * ========================================================================== 1072 * Execute the I/O pipeline 1073 * ========================================================================== 1074 */ 1075 1076static void 1077zio_taskq_dispatch(zio_t *zio, enum zio_taskq_type q, boolean_t cutinline) 1078{ 1079 spa_t *spa = zio->io_spa; 1080 zio_type_t t = zio->io_type; 1081 int flags = TQ_SLEEP | (cutinline ? TQ_FRONT : 0); 1082 1083 ASSERT(q == ZIO_TASKQ_ISSUE || q == ZIO_TASKQ_INTERRUPT); 1084 1085 /* 1086 * If we're a config writer or a probe, the normal issue and 1087 * interrupt threads may all be blocked waiting for the config lock. 1088 * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL. 1089 */ 1090 if (zio->io_flags & (ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_PROBE)) 1091 t = ZIO_TYPE_NULL; 1092 1093 /* 1094 * A similar issue exists for the L2ARC write thread until L2ARC 2.0. 1095 */ 1096 if (t == ZIO_TYPE_WRITE && zio->io_vd && zio->io_vd->vdev_aux) 1097 t = ZIO_TYPE_NULL; 1098 1099 /* 1100 * If this is a high priority I/O, then use the high priority taskq. 1101 */ 1102 if (zio->io_priority == ZIO_PRIORITY_NOW && 1103 spa->spa_zio_taskq[t][q + 1] != NULL) 1104 q++; 1105 1106 ASSERT3U(q, <, ZIO_TASKQ_TYPES); 1107#ifdef _KERNEL 1108 (void) taskq_dispatch_safe(spa->spa_zio_taskq[t][q], 1109 (task_func_t *)zio_execute, zio, flags, &zio->io_task); 1110#else 1111 (void) taskq_dispatch(spa->spa_zio_taskq[t][q], 1112 (task_func_t *)zio_execute, zio, flags); 1113#endif 1114} 1115 1116static boolean_t 1117zio_taskq_member(zio_t *zio, enum zio_taskq_type q) 1118{ 1119 kthread_t *executor = zio->io_executor; 1120 spa_t *spa = zio->io_spa; 1121 1122 for (zio_type_t t = 0; t < ZIO_TYPES; t++) 1123 if (taskq_member(spa->spa_zio_taskq[t][q], executor)) 1124 return (B_TRUE); 1125 1126 return (B_FALSE); 1127} 1128 1129static int 1130zio_issue_async(zio_t *zio) 1131{ 1132 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 1133 1134 return (ZIO_PIPELINE_STOP); 1135} 1136 1137void 1138zio_interrupt(zio_t *zio) 1139{ 1140 zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE); 1141} 1142 1143/* 1144 * Execute the I/O pipeline until one of the following occurs: 1145 * (1) the I/O completes; (2) the pipeline stalls waiting for 1146 * dependent child I/Os; (3) the I/O issues, so we're waiting 1147 * for an I/O completion interrupt; (4) the I/O is delegated by 1148 * vdev-level caching or aggregation; (5) the I/O is deferred 1149 * due to vdev-level queueing; (6) the I/O is handed off to 1150 * another thread. In all cases, the pipeline stops whenever 1151 * there's no CPU work; it never burns a thread in cv_wait(). 1152 * 1153 * There's no locking on io_stage because there's no legitimate way 1154 * for multiple threads to be attempting to process the same I/O. 1155 */ 1156static zio_pipe_stage_t *zio_pipeline[]; 1157 1158void 1159zio_execute(zio_t *zio) 1160{ 1161 zio->io_executor = curthread; 1162 1163 while (zio->io_stage < ZIO_STAGE_DONE) { 1164 enum zio_stage pipeline = zio->io_pipeline; 1165 enum zio_stage stage = zio->io_stage; 1166 int rv; 1167 1168 ASSERT(!MUTEX_HELD(&zio->io_lock)); 1169 ASSERT(ISP2(stage)); 1170 ASSERT(zio->io_stall == NULL); 1171 1172 do { 1173 stage <<= 1; 1174 } while ((stage & pipeline) == 0); 1175 1176 ASSERT(stage <= ZIO_STAGE_DONE); 1177 1178 /* 1179 * If we are in interrupt context and this pipeline stage 1180 * will grab a config lock that is held across I/O, 1181 * or may wait for an I/O that needs an interrupt thread 1182 * to complete, issue async to avoid deadlock. 1183 * 1184 * For VDEV_IO_START, we cut in line so that the io will 1185 * be sent to disk promptly. 1186 */ 1187 if ((stage & ZIO_BLOCKING_STAGES) && zio->io_vd == NULL && 1188 zio_taskq_member(zio, ZIO_TASKQ_INTERRUPT)) { 1189 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ? 1190 zio_requeue_io_start_cut_in_line : B_FALSE; 1191 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut); 1192 return; 1193 } 1194 1195 zio->io_stage = stage; 1196 rv = zio_pipeline[highbit(stage) - 1](zio); 1197 1198 if (rv == ZIO_PIPELINE_STOP) 1199 return; 1200 1201 ASSERT(rv == ZIO_PIPELINE_CONTINUE); 1202 } 1203} 1204 1205/* 1206 * ========================================================================== 1207 * Initiate I/O, either sync or async 1208 * ========================================================================== 1209 */ 1210int 1211zio_wait(zio_t *zio) 1212{ 1213 int error; 1214 1215 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 1216 ASSERT(zio->io_executor == NULL); 1217 1218 zio->io_waiter = curthread; 1219 1220 zio_execute(zio); 1221 1222 mutex_enter(&zio->io_lock); 1223 while (zio->io_executor != NULL) 1224 cv_wait(&zio->io_cv, &zio->io_lock); 1225 mutex_exit(&zio->io_lock); 1226 1227 error = zio->io_error; 1228 zio_destroy(zio); 1229 1230 return (error); 1231} 1232 1233void 1234zio_nowait(zio_t *zio) 1235{ 1236 ASSERT(zio->io_executor == NULL); 1237 1238 if (zio->io_child_type == ZIO_CHILD_LOGICAL && 1239 zio_unique_parent(zio) == NULL) { 1240 /* 1241 * This is a logical async I/O with no parent to wait for it. 1242 * We add it to the spa_async_root_zio "Godfather" I/O which 1243 * will ensure they complete prior to unloading the pool. 1244 */ 1245 spa_t *spa = zio->io_spa; 1246 1247 zio_add_child(spa->spa_async_zio_root, zio); 1248 } 1249 1250 zio_execute(zio); 1251} 1252 1253/* 1254 * ========================================================================== 1255 * Reexecute or suspend/resume failed I/O 1256 * ========================================================================== 1257 */ 1258 1259static void 1260zio_reexecute(zio_t *pio) 1261{ 1262 zio_t *cio, *cio_next; 1263 1264 ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL); 1265 ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN); 1266 ASSERT(pio->io_gang_leader == NULL); 1267 ASSERT(pio->io_gang_tree == NULL); 1268 1269 pio->io_flags = pio->io_orig_flags; 1270 pio->io_stage = pio->io_orig_stage; 1271 pio->io_pipeline = pio->io_orig_pipeline; 1272 pio->io_reexecute = 0; 1273 pio->io_error = 0; 1274 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1275 pio->io_state[w] = 0; 1276 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 1277 pio->io_child_error[c] = 0; 1278 1279 if (IO_IS_ALLOCATING(pio)) 1280 BP_ZERO(pio->io_bp); 1281 1282 /* 1283 * As we reexecute pio's children, new children could be created. 1284 * New children go to the head of pio's io_child_list, however, 1285 * so we will (correctly) not reexecute them. The key is that 1286 * the remainder of pio's io_child_list, from 'cio_next' onward, 1287 * cannot be affected by any side effects of reexecuting 'cio'. 1288 */ 1289 for (cio = zio_walk_children(pio); cio != NULL; cio = cio_next) { 1290 cio_next = zio_walk_children(pio); 1291 mutex_enter(&pio->io_lock); 1292 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1293 pio->io_children[cio->io_child_type][w]++; 1294 mutex_exit(&pio->io_lock); 1295 zio_reexecute(cio); 1296 } 1297 1298 /* 1299 * Now that all children have been reexecuted, execute the parent. 1300 * We don't reexecute "The Godfather" I/O here as it's the 1301 * responsibility of the caller to wait on him. 1302 */ 1303 if (!(pio->io_flags & ZIO_FLAG_GODFATHER)) 1304 zio_execute(pio); 1305} 1306 1307void 1308zio_suspend(spa_t *spa, zio_t *zio) 1309{ 1310 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC) 1311 fm_panic("Pool '%s' has encountered an uncorrectable I/O " 1312 "failure and the failure mode property for this pool " 1313 "is set to panic.", spa_name(spa)); 1314 1315 zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL, NULL, 0, 0); 1316 1317 mutex_enter(&spa->spa_suspend_lock); 1318 1319 if (spa->spa_suspend_zio_root == NULL) 1320 spa->spa_suspend_zio_root = zio_root(spa, NULL, NULL, 1321 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | 1322 ZIO_FLAG_GODFATHER); 1323 1324 spa->spa_suspended = B_TRUE; 1325 1326 if (zio != NULL) { 1327 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 1328 ASSERT(zio != spa->spa_suspend_zio_root); 1329 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1330 ASSERT(zio_unique_parent(zio) == NULL); 1331 ASSERT(zio->io_stage == ZIO_STAGE_DONE); 1332 zio_add_child(spa->spa_suspend_zio_root, zio); 1333 } 1334 1335 mutex_exit(&spa->spa_suspend_lock); 1336} 1337 1338int 1339zio_resume(spa_t *spa) 1340{ 1341 zio_t *pio; 1342 1343 /* 1344 * Reexecute all previously suspended i/o. 1345 */ 1346 mutex_enter(&spa->spa_suspend_lock); 1347 spa->spa_suspended = B_FALSE; 1348 cv_broadcast(&spa->spa_suspend_cv); 1349 pio = spa->spa_suspend_zio_root; 1350 spa->spa_suspend_zio_root = NULL; 1351 mutex_exit(&spa->spa_suspend_lock); 1352 1353 if (pio == NULL) 1354 return (0); 1355 1356 zio_reexecute(pio); 1357 return (zio_wait(pio)); 1358} 1359 1360void 1361zio_resume_wait(spa_t *spa) 1362{ 1363 mutex_enter(&spa->spa_suspend_lock); 1364 while (spa_suspended(spa)) 1365 cv_wait(&spa->spa_suspend_cv, &spa->spa_suspend_lock); 1366 mutex_exit(&spa->spa_suspend_lock); 1367} 1368 1369/* 1370 * ========================================================================== 1371 * Gang blocks. 1372 * 1373 * A gang block is a collection of small blocks that looks to the DMU 1374 * like one large block. When zio_dva_allocate() cannot find a block 1375 * of the requested size, due to either severe fragmentation or the pool 1376 * being nearly full, it calls zio_write_gang_block() to construct the 1377 * block from smaller fragments. 1378 * 1379 * A gang block consists of a gang header (zio_gbh_phys_t) and up to 1380 * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like 1381 * an indirect block: it's an array of block pointers. It consumes 1382 * only one sector and hence is allocatable regardless of fragmentation. 1383 * The gang header's bps point to its gang members, which hold the data. 1384 * 1385 * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg> 1386 * as the verifier to ensure uniqueness of the SHA256 checksum. 1387 * Critically, the gang block bp's blk_cksum is the checksum of the data, 1388 * not the gang header. This ensures that data block signatures (needed for 1389 * deduplication) are independent of how the block is physically stored. 1390 * 1391 * Gang blocks can be nested: a gang member may itself be a gang block. 1392 * Thus every gang block is a tree in which root and all interior nodes are 1393 * gang headers, and the leaves are normal blocks that contain user data. 1394 * The root of the gang tree is called the gang leader. 1395 * 1396 * To perform any operation (read, rewrite, free, claim) on a gang block, 1397 * zio_gang_assemble() first assembles the gang tree (minus data leaves) 1398 * in the io_gang_tree field of the original logical i/o by recursively 1399 * reading the gang leader and all gang headers below it. This yields 1400 * an in-core tree containing the contents of every gang header and the 1401 * bps for every constituent of the gang block. 1402 * 1403 * With the gang tree now assembled, zio_gang_issue() just walks the gang tree 1404 * and invokes a callback on each bp. To free a gang block, zio_gang_issue() 1405 * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp. 1406 * zio_claim_gang() provides a similarly trivial wrapper for zio_claim(). 1407 * zio_read_gang() is a wrapper around zio_read() that omits reading gang 1408 * headers, since we already have those in io_gang_tree. zio_rewrite_gang() 1409 * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite() 1410 * of the gang header plus zio_checksum_compute() of the data to update the 1411 * gang header's blk_cksum as described above. 1412 * 1413 * The two-phase assemble/issue model solves the problem of partial failure -- 1414 * what if you'd freed part of a gang block but then couldn't read the 1415 * gang header for another part? Assembling the entire gang tree first 1416 * ensures that all the necessary gang header I/O has succeeded before 1417 * starting the actual work of free, claim, or write. Once the gang tree 1418 * is assembled, free and claim are in-memory operations that cannot fail. 1419 * 1420 * In the event that a gang write fails, zio_dva_unallocate() walks the 1421 * gang tree to immediately free (i.e. insert back into the space map) 1422 * everything we've allocated. This ensures that we don't get ENOSPC 1423 * errors during repeated suspend/resume cycles due to a flaky device. 1424 * 1425 * Gang rewrites only happen during sync-to-convergence. If we can't assemble 1426 * the gang tree, we won't modify the block, so we can safely defer the free 1427 * (knowing that the block is still intact). If we *can* assemble the gang 1428 * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free 1429 * each constituent bp and we can allocate a new block on the next sync pass. 1430 * 1431 * In all cases, the gang tree allows complete recovery from partial failure. 1432 * ========================================================================== 1433 */ 1434 1435static zio_t * 1436zio_read_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1437{ 1438 if (gn != NULL) 1439 return (pio); 1440 1441 return (zio_read(pio, pio->io_spa, bp, data, BP_GET_PSIZE(bp), 1442 NULL, NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 1443 &pio->io_bookmark)); 1444} 1445 1446zio_t * 1447zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1448{ 1449 zio_t *zio; 1450 1451 if (gn != NULL) { 1452 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1453 gn->gn_gbh, SPA_GANGBLOCKSIZE, NULL, NULL, pio->io_priority, 1454 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1455 /* 1456 * As we rewrite each gang header, the pipeline will compute 1457 * a new gang block header checksum for it; but no one will 1458 * compute a new data checksum, so we do that here. The one 1459 * exception is the gang leader: the pipeline already computed 1460 * its data checksum because that stage precedes gang assembly. 1461 * (Presently, nothing actually uses interior data checksums; 1462 * this is just good hygiene.) 1463 */ 1464 if (gn != pio->io_gang_leader->io_gang_tree) { 1465 zio_checksum_compute(zio, BP_GET_CHECKSUM(bp), 1466 data, BP_GET_PSIZE(bp)); 1467 } 1468 /* 1469 * If we are here to damage data for testing purposes, 1470 * leave the GBH alone so that we can detect the damage. 1471 */ 1472 if (pio->io_gang_leader->io_flags & ZIO_FLAG_INDUCE_DAMAGE) 1473 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 1474 } else { 1475 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1476 data, BP_GET_PSIZE(bp), NULL, NULL, pio->io_priority, 1477 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1478 } 1479 1480 return (zio); 1481} 1482 1483/* ARGSUSED */ 1484zio_t * 1485zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1486{ 1487 return (zio_free_sync(pio, pio->io_spa, pio->io_txg, bp, 1488 ZIO_GANG_CHILD_FLAGS(pio))); 1489} 1490 1491/* ARGSUSED */ 1492zio_t * 1493zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1494{ 1495 return (zio_claim(pio, pio->io_spa, pio->io_txg, bp, 1496 NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio))); 1497} 1498 1499static zio_gang_issue_func_t *zio_gang_issue_func[ZIO_TYPES] = { 1500 NULL, 1501 zio_read_gang, 1502 zio_rewrite_gang, 1503 zio_free_gang, 1504 zio_claim_gang, 1505 NULL 1506}; 1507 1508static void zio_gang_tree_assemble_done(zio_t *zio); 1509 1510static zio_gang_node_t * 1511zio_gang_node_alloc(zio_gang_node_t **gnpp) 1512{ 1513 zio_gang_node_t *gn; 1514 1515 ASSERT(*gnpp == NULL); 1516 1517 gn = kmem_zalloc(sizeof (*gn), KM_SLEEP); 1518 gn->gn_gbh = zio_buf_alloc(SPA_GANGBLOCKSIZE); 1519 *gnpp = gn; 1520 1521 return (gn); 1522} 1523 1524static void 1525zio_gang_node_free(zio_gang_node_t **gnpp) 1526{ 1527 zio_gang_node_t *gn = *gnpp; 1528 1529 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 1530 ASSERT(gn->gn_child[g] == NULL); 1531 1532 zio_buf_free(gn->gn_gbh, SPA_GANGBLOCKSIZE); 1533 kmem_free(gn, sizeof (*gn)); 1534 *gnpp = NULL; 1535} 1536 1537static void 1538zio_gang_tree_free(zio_gang_node_t **gnpp) 1539{ 1540 zio_gang_node_t *gn = *gnpp; 1541 1542 if (gn == NULL) 1543 return; 1544 1545 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 1546 zio_gang_tree_free(&gn->gn_child[g]); 1547 1548 zio_gang_node_free(gnpp); 1549} 1550 1551static void 1552zio_gang_tree_assemble(zio_t *gio, blkptr_t *bp, zio_gang_node_t **gnpp) 1553{ 1554 zio_gang_node_t *gn = zio_gang_node_alloc(gnpp); 1555 1556 ASSERT(gio->io_gang_leader == gio); 1557 ASSERT(BP_IS_GANG(bp)); 1558 1559 zio_nowait(zio_read(gio, gio->io_spa, bp, gn->gn_gbh, 1560 SPA_GANGBLOCKSIZE, zio_gang_tree_assemble_done, gn, 1561 gio->io_priority, ZIO_GANG_CHILD_FLAGS(gio), &gio->io_bookmark)); 1562} 1563 1564static void 1565zio_gang_tree_assemble_done(zio_t *zio) 1566{ 1567 zio_t *gio = zio->io_gang_leader; 1568 zio_gang_node_t *gn = zio->io_private; 1569 blkptr_t *bp = zio->io_bp; 1570 1571 ASSERT(gio == zio_unique_parent(zio)); 1572 ASSERT(zio->io_child_count == 0); 1573 1574 if (zio->io_error) 1575 return; 1576 1577 if (BP_SHOULD_BYTESWAP(bp)) 1578 byteswap_uint64_array(zio->io_data, zio->io_size); 1579 1580 ASSERT(zio->io_data == gn->gn_gbh); 1581 ASSERT(zio->io_size == SPA_GANGBLOCKSIZE); 1582 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 1583 1584 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 1585 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 1586 if (!BP_IS_GANG(gbp)) 1587 continue; 1588 zio_gang_tree_assemble(gio, gbp, &gn->gn_child[g]); 1589 } 1590} 1591 1592static void 1593zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, void *data) 1594{ 1595 zio_t *gio = pio->io_gang_leader; 1596 zio_t *zio; 1597 1598 ASSERT(BP_IS_GANG(bp) == !!gn); 1599 ASSERT(BP_GET_CHECKSUM(bp) == BP_GET_CHECKSUM(gio->io_bp)); 1600 ASSERT(BP_GET_LSIZE(bp) == BP_GET_PSIZE(bp) || gn == gio->io_gang_tree); 1601 1602 /* 1603 * If you're a gang header, your data is in gn->gn_gbh. 1604 * If you're a gang member, your data is in 'data' and gn == NULL. 1605 */ 1606 zio = zio_gang_issue_func[gio->io_type](pio, bp, gn, data); 1607 1608 if (gn != NULL) { 1609 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 1610 1611 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 1612 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 1613 if (BP_IS_HOLE(gbp)) 1614 continue; 1615 zio_gang_tree_issue(zio, gn->gn_child[g], gbp, data); 1616 data = (char *)data + BP_GET_PSIZE(gbp); 1617 } 1618 } 1619 1620 if (gn == gio->io_gang_tree) 1621 ASSERT3P((char *)gio->io_data + gio->io_size, ==, data); 1622 1623 if (zio != pio) 1624 zio_nowait(zio); 1625} 1626 1627static int 1628zio_gang_assemble(zio_t *zio) 1629{ 1630 blkptr_t *bp = zio->io_bp; 1631 1632 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == NULL); 1633 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 1634 1635 zio->io_gang_leader = zio; 1636 1637 zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree); 1638 1639 return (ZIO_PIPELINE_CONTINUE); 1640} 1641 1642static int 1643zio_gang_issue(zio_t *zio) 1644{ 1645 blkptr_t *bp = zio->io_bp; 1646 1647 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE)) 1648 return (ZIO_PIPELINE_STOP); 1649 1650 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio); 1651 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 1652 1653 if (zio->io_child_error[ZIO_CHILD_GANG] == 0) 1654 zio_gang_tree_issue(zio, zio->io_gang_tree, bp, zio->io_data); 1655 else 1656 zio_gang_tree_free(&zio->io_gang_tree); 1657 1658 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1659 1660 return (ZIO_PIPELINE_CONTINUE); 1661} 1662 1663static void 1664zio_write_gang_member_ready(zio_t *zio) 1665{ 1666 zio_t *pio = zio_unique_parent(zio); 1667 zio_t *gio = zio->io_gang_leader; 1668 dva_t *cdva = zio->io_bp->blk_dva; 1669 dva_t *pdva = pio->io_bp->blk_dva; 1670 uint64_t asize; 1671 1672 if (BP_IS_HOLE(zio->io_bp)) 1673 return; 1674 1675 ASSERT(BP_IS_HOLE(&zio->io_bp_orig)); 1676 1677 ASSERT(zio->io_child_type == ZIO_CHILD_GANG); 1678 ASSERT3U(zio->io_prop.zp_copies, ==, gio->io_prop.zp_copies); 1679 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp)); 1680 ASSERT3U(pio->io_prop.zp_copies, <=, BP_GET_NDVAS(pio->io_bp)); 1681 ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp)); 1682 1683 mutex_enter(&pio->io_lock); 1684 for (int d = 0; d < BP_GET_NDVAS(zio->io_bp); d++) { 1685 ASSERT(DVA_GET_GANG(&pdva[d])); 1686 asize = DVA_GET_ASIZE(&pdva[d]); 1687 asize += DVA_GET_ASIZE(&cdva[d]); 1688 DVA_SET_ASIZE(&pdva[d], asize); 1689 } 1690 mutex_exit(&pio->io_lock); 1691} 1692 1693static int 1694zio_write_gang_block(zio_t *pio) 1695{ 1696 spa_t *spa = pio->io_spa; 1697 blkptr_t *bp = pio->io_bp; 1698 zio_t *gio = pio->io_gang_leader; 1699 zio_t *zio; 1700 zio_gang_node_t *gn, **gnpp; 1701 zio_gbh_phys_t *gbh; 1702 uint64_t txg = pio->io_txg; 1703 uint64_t resid = pio->io_size; 1704 uint64_t lsize; 1705 int copies = gio->io_prop.zp_copies; 1706 int gbh_copies = MIN(copies + 1, spa_max_replication(spa)); 1707 zio_prop_t zp; 1708 int error; 1709 1710 error = metaslab_alloc(spa, spa_normal_class(spa), SPA_GANGBLOCKSIZE, 1711 bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp, 1712 METASLAB_HINTBP_FAVOR | METASLAB_GANG_HEADER); 1713 if (error) { 1714 pio->io_error = error; 1715 return (ZIO_PIPELINE_CONTINUE); 1716 } 1717 1718 if (pio == gio) { 1719 gnpp = &gio->io_gang_tree; 1720 } else { 1721 gnpp = pio->io_private; 1722 ASSERT(pio->io_ready == zio_write_gang_member_ready); 1723 } 1724 1725 gn = zio_gang_node_alloc(gnpp); 1726 gbh = gn->gn_gbh; 1727 bzero(gbh, SPA_GANGBLOCKSIZE); 1728 1729 /* 1730 * Create the gang header. 1731 */ 1732 zio = zio_rewrite(pio, spa, txg, bp, gbh, SPA_GANGBLOCKSIZE, NULL, NULL, 1733 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1734 1735 /* 1736 * Create and nowait the gang children. 1737 */ 1738 for (int g = 0; resid != 0; resid -= lsize, g++) { 1739 lsize = P2ROUNDUP(resid / (SPA_GBH_NBLKPTRS - g), 1740 SPA_MINBLOCKSIZE); 1741 ASSERT(lsize >= SPA_MINBLOCKSIZE && lsize <= resid); 1742 1743 zp.zp_checksum = gio->io_prop.zp_checksum; 1744 zp.zp_compress = ZIO_COMPRESS_OFF; 1745 zp.zp_type = DMU_OT_NONE; 1746 zp.zp_level = 0; 1747 zp.zp_copies = gio->io_prop.zp_copies; 1748 zp.zp_dedup = 0; 1749 zp.zp_dedup_verify = 0; 1750 1751 zio_nowait(zio_write(zio, spa, txg, &gbh->zg_blkptr[g], 1752 (char *)pio->io_data + (pio->io_size - resid), lsize, &zp, 1753 zio_write_gang_member_ready, NULL, &gn->gn_child[g], 1754 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 1755 &pio->io_bookmark)); 1756 } 1757 1758 /* 1759 * Set pio's pipeline to just wait for zio to finish. 1760 */ 1761 pio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1762 1763 zio_nowait(zio); 1764 1765 return (ZIO_PIPELINE_CONTINUE); 1766} 1767 1768/* 1769 * ========================================================================== 1770 * Dedup 1771 * ========================================================================== 1772 */ 1773static void 1774zio_ddt_child_read_done(zio_t *zio) 1775{ 1776 blkptr_t *bp = zio->io_bp; 1777 ddt_entry_t *dde = zio->io_private; 1778 ddt_phys_t *ddp; 1779 zio_t *pio = zio_unique_parent(zio); 1780 1781 mutex_enter(&pio->io_lock); 1782 ddp = ddt_phys_select(dde, bp); 1783 if (zio->io_error == 0) 1784 ddt_phys_clear(ddp); /* this ddp doesn't need repair */ 1785 if (zio->io_error == 0 && dde->dde_repair_data == NULL) 1786 dde->dde_repair_data = zio->io_data; 1787 else 1788 zio_buf_free(zio->io_data, zio->io_size); 1789 mutex_exit(&pio->io_lock); 1790} 1791 1792static int 1793zio_ddt_read_start(zio_t *zio) 1794{ 1795 blkptr_t *bp = zio->io_bp; 1796 1797 ASSERT(BP_GET_DEDUP(bp)); 1798 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 1799 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1800 1801 if (zio->io_child_error[ZIO_CHILD_DDT]) { 1802 ddt_t *ddt = ddt_select(zio->io_spa, bp); 1803 ddt_entry_t *dde = ddt_repair_start(ddt, bp); 1804 ddt_phys_t *ddp = dde->dde_phys; 1805 ddt_phys_t *ddp_self = ddt_phys_select(dde, bp); 1806 blkptr_t blk; 1807 1808 ASSERT(zio->io_vsd == NULL); 1809 zio->io_vsd = dde; 1810 1811 if (ddp_self == NULL) 1812 return (ZIO_PIPELINE_CONTINUE); 1813 1814 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { 1815 if (ddp->ddp_phys_birth == 0 || ddp == ddp_self) 1816 continue; 1817 ddt_bp_create(ddt->ddt_checksum, &dde->dde_key, ddp, 1818 &blk); 1819 zio_nowait(zio_read(zio, zio->io_spa, &blk, 1820 zio_buf_alloc(zio->io_size), zio->io_size, 1821 zio_ddt_child_read_done, dde, zio->io_priority, 1822 ZIO_DDT_CHILD_FLAGS(zio) | ZIO_FLAG_DONT_PROPAGATE, 1823 &zio->io_bookmark)); 1824 } 1825 return (ZIO_PIPELINE_CONTINUE); 1826 } 1827 1828 zio_nowait(zio_read(zio, zio->io_spa, bp, 1829 zio->io_data, zio->io_size, NULL, NULL, zio->io_priority, 1830 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark)); 1831 1832 return (ZIO_PIPELINE_CONTINUE); 1833} 1834 1835static int 1836zio_ddt_read_done(zio_t *zio) 1837{ 1838 blkptr_t *bp = zio->io_bp; 1839 1840 if (zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE)) 1841 return (ZIO_PIPELINE_STOP); 1842 1843 ASSERT(BP_GET_DEDUP(bp)); 1844 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 1845 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1846 1847 if (zio->io_child_error[ZIO_CHILD_DDT]) { 1848 ddt_t *ddt = ddt_select(zio->io_spa, bp); 1849 ddt_entry_t *dde = zio->io_vsd; 1850 if (ddt == NULL) { 1851 ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE); 1852 return (ZIO_PIPELINE_CONTINUE); 1853 } 1854 if (dde == NULL) { 1855 zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1; 1856 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 1857 return (ZIO_PIPELINE_STOP); 1858 } 1859 if (dde->dde_repair_data != NULL) { 1860 bcopy(dde->dde_repair_data, zio->io_data, zio->io_size); 1861 zio->io_child_error[ZIO_CHILD_DDT] = 0; 1862 } 1863 ddt_repair_done(ddt, dde); 1864 zio->io_vsd = NULL; 1865 } 1866 1867 ASSERT(zio->io_vsd == NULL); 1868 1869 return (ZIO_PIPELINE_CONTINUE); 1870} 1871 1872static boolean_t 1873zio_ddt_collision(zio_t *zio, ddt_t *ddt, ddt_entry_t *dde) 1874{ 1875 spa_t *spa = zio->io_spa; 1876 1877 /* 1878 * Note: we compare the original data, not the transformed data, 1879 * because when zio->io_bp is an override bp, we will not have 1880 * pushed the I/O transforms. That's an important optimization 1881 * because otherwise we'd compress/encrypt all dmu_sync() data twice. 1882 */ 1883 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 1884 zio_t *lio = dde->dde_lead_zio[p]; 1885 1886 if (lio != NULL) { 1887 return (lio->io_orig_size != zio->io_orig_size || 1888 bcmp(zio->io_orig_data, lio->io_orig_data, 1889 zio->io_orig_size) != 0); 1890 } 1891 } 1892 1893 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 1894 ddt_phys_t *ddp = &dde->dde_phys[p]; 1895 1896 if (ddp->ddp_phys_birth != 0) { 1897 arc_buf_t *abuf = NULL; 1898 uint32_t aflags = ARC_WAIT; 1899 blkptr_t blk = *zio->io_bp; 1900 int error; 1901 1902 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth); 1903 1904 ddt_exit(ddt); 1905 1906 error = arc_read_nolock(NULL, spa, &blk, 1907 arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ, 1908 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, 1909 &aflags, &zio->io_bookmark); 1910 1911 if (error == 0) { 1912 if (arc_buf_size(abuf) != zio->io_orig_size || 1913 bcmp(abuf->b_data, zio->io_orig_data, 1914 zio->io_orig_size) != 0) 1915 error = EEXIST; 1916 VERIFY(arc_buf_remove_ref(abuf, &abuf) == 1); 1917 } 1918 1919 ddt_enter(ddt); 1920 return (error != 0); 1921 } 1922 } 1923 1924 return (B_FALSE); 1925} 1926 1927static void 1928zio_ddt_child_write_ready(zio_t *zio) 1929{ 1930 int p = zio->io_prop.zp_copies; 1931 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 1932 ddt_entry_t *dde = zio->io_private; 1933 ddt_phys_t *ddp = &dde->dde_phys[p]; 1934 zio_t *pio; 1935 1936 if (zio->io_error) 1937 return; 1938 1939 ddt_enter(ddt); 1940 1941 ASSERT(dde->dde_lead_zio[p] == zio); 1942 1943 ddt_phys_fill(ddp, zio->io_bp); 1944 1945 while ((pio = zio_walk_parents(zio)) != NULL) 1946 ddt_bp_fill(ddp, pio->io_bp, zio->io_txg); 1947 1948 ddt_exit(ddt); 1949} 1950 1951static void 1952zio_ddt_child_write_done(zio_t *zio) 1953{ 1954 int p = zio->io_prop.zp_copies; 1955 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 1956 ddt_entry_t *dde = zio->io_private; 1957 ddt_phys_t *ddp = &dde->dde_phys[p]; 1958 1959 ddt_enter(ddt); 1960 1961 ASSERT(ddp->ddp_refcnt == 0); 1962 ASSERT(dde->dde_lead_zio[p] == zio); 1963 dde->dde_lead_zio[p] = NULL; 1964 1965 if (zio->io_error == 0) { 1966 while (zio_walk_parents(zio) != NULL) 1967 ddt_phys_addref(ddp); 1968 } else { 1969 ddt_phys_clear(ddp); 1970 } 1971 1972 ddt_exit(ddt); 1973} 1974 1975static void 1976zio_ddt_ditto_write_done(zio_t *zio) 1977{ 1978 int p = DDT_PHYS_DITTO; 1979 zio_prop_t *zp = &zio->io_prop; 1980 blkptr_t *bp = zio->io_bp; 1981 ddt_t *ddt = ddt_select(zio->io_spa, bp); 1982 ddt_entry_t *dde = zio->io_private; 1983 ddt_phys_t *ddp = &dde->dde_phys[p]; 1984 ddt_key_t *ddk = &dde->dde_key; 1985 1986 ddt_enter(ddt); 1987 1988 ASSERT(ddp->ddp_refcnt == 0); 1989 ASSERT(dde->dde_lead_zio[p] == zio); 1990 dde->dde_lead_zio[p] = NULL; 1991 1992 if (zio->io_error == 0) { 1993 ASSERT(ZIO_CHECKSUM_EQUAL(bp->blk_cksum, ddk->ddk_cksum)); 1994 ASSERT(zp->zp_copies < SPA_DVAS_PER_BP); 1995 ASSERT(zp->zp_copies == BP_GET_NDVAS(bp) - BP_IS_GANG(bp)); 1996 if (ddp->ddp_phys_birth != 0) 1997 ddt_phys_free(ddt, ddk, ddp, zio->io_txg); 1998 ddt_phys_fill(ddp, bp); 1999 } 2000 2001 ddt_exit(ddt); 2002} 2003 2004static int 2005zio_ddt_write(zio_t *zio) 2006{ 2007 spa_t *spa = zio->io_spa; 2008 blkptr_t *bp = zio->io_bp; 2009 uint64_t txg = zio->io_txg; 2010 zio_prop_t *zp = &zio->io_prop; 2011 int p = zp->zp_copies; 2012 int ditto_copies; 2013 zio_t *cio = NULL; 2014 zio_t *dio = NULL; 2015 ddt_t *ddt = ddt_select(spa, bp); 2016 ddt_entry_t *dde; 2017 ddt_phys_t *ddp; 2018 2019 ASSERT(BP_GET_DEDUP(bp)); 2020 ASSERT(BP_GET_CHECKSUM(bp) == zp->zp_checksum); 2021 ASSERT(BP_IS_HOLE(bp) || zio->io_bp_override); 2022 2023 ddt_enter(ddt); 2024 dde = ddt_lookup(ddt, bp, B_TRUE); 2025 ddp = &dde->dde_phys[p]; 2026 2027 if (zp->zp_dedup_verify && zio_ddt_collision(zio, ddt, dde)) { 2028 /* 2029 * If we're using a weak checksum, upgrade to a strong checksum 2030 * and try again. If we're already using a strong checksum, 2031 * we can't resolve it, so just convert to an ordinary write. 2032 * (And automatically e-mail a paper to Nature?) 2033 */ 2034 if (!zio_checksum_table[zp->zp_checksum].ci_dedup) { 2035 zp->zp_checksum = spa_dedup_checksum(spa); 2036 zio_pop_transforms(zio); 2037 zio->io_stage = ZIO_STAGE_OPEN; 2038 BP_ZERO(bp); 2039 } else { 2040 zp->zp_dedup = 0; 2041 } 2042 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2043 ddt_exit(ddt); 2044 return (ZIO_PIPELINE_CONTINUE); 2045 } 2046 2047 ditto_copies = ddt_ditto_copies_needed(ddt, dde, ddp); 2048 ASSERT(ditto_copies < SPA_DVAS_PER_BP); 2049 2050 if (ditto_copies > ddt_ditto_copies_present(dde) && 2051 dde->dde_lead_zio[DDT_PHYS_DITTO] == NULL) { 2052 zio_prop_t czp = *zp; 2053 2054 czp.zp_copies = ditto_copies; 2055 2056 /* 2057 * If we arrived here with an override bp, we won't have run 2058 * the transform stack, so we won't have the data we need to 2059 * generate a child i/o. So, toss the override bp and restart. 2060 * This is safe, because using the override bp is just an 2061 * optimization; and it's rare, so the cost doesn't matter. 2062 */ 2063 if (zio->io_bp_override) { 2064 zio_pop_transforms(zio); 2065 zio->io_stage = ZIO_STAGE_OPEN; 2066 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2067 zio->io_bp_override = NULL; 2068 BP_ZERO(bp); 2069 ddt_exit(ddt); 2070 return (ZIO_PIPELINE_CONTINUE); 2071 } 2072 2073 dio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2074 zio->io_orig_size, &czp, NULL, 2075 zio_ddt_ditto_write_done, dde, zio->io_priority, 2076 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2077 2078 zio_push_transform(dio, zio->io_data, zio->io_size, 0, NULL); 2079 dde->dde_lead_zio[DDT_PHYS_DITTO] = dio; 2080 } 2081 2082 if (ddp->ddp_phys_birth != 0 || dde->dde_lead_zio[p] != NULL) { 2083 if (ddp->ddp_phys_birth != 0) 2084 ddt_bp_fill(ddp, bp, txg); 2085 if (dde->dde_lead_zio[p] != NULL) 2086 zio_add_child(zio, dde->dde_lead_zio[p]); 2087 else 2088 ddt_phys_addref(ddp); 2089 } else if (zio->io_bp_override) { 2090 ASSERT(bp->blk_birth == txg); 2091 ASSERT(BP_EQUAL(bp, zio->io_bp_override)); 2092 ddt_phys_fill(ddp, bp); 2093 ddt_phys_addref(ddp); 2094 } else { 2095 cio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2096 zio->io_orig_size, zp, zio_ddt_child_write_ready, 2097 zio_ddt_child_write_done, dde, zio->io_priority, 2098 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2099 2100 zio_push_transform(cio, zio->io_data, zio->io_size, 0, NULL); 2101 dde->dde_lead_zio[p] = cio; 2102 } 2103 2104 ddt_exit(ddt); 2105 2106 if (cio) 2107 zio_nowait(cio); 2108 if (dio) 2109 zio_nowait(dio); 2110 2111 return (ZIO_PIPELINE_CONTINUE); 2112} 2113 2114ddt_entry_t *freedde; /* for debugging */ 2115 2116static int 2117zio_ddt_free(zio_t *zio) 2118{ 2119 spa_t *spa = zio->io_spa; 2120 blkptr_t *bp = zio->io_bp; 2121 ddt_t *ddt = ddt_select(spa, bp); 2122 ddt_entry_t *dde; 2123 ddt_phys_t *ddp; 2124 2125 ASSERT(BP_GET_DEDUP(bp)); 2126 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2127 2128 ddt_enter(ddt); 2129 freedde = dde = ddt_lookup(ddt, bp, B_TRUE); 2130 ddp = ddt_phys_select(dde, bp); 2131 ddt_phys_decref(ddp); 2132 ddt_exit(ddt); 2133 2134 return (ZIO_PIPELINE_CONTINUE); 2135} 2136 2137/* 2138 * ========================================================================== 2139 * Allocate and free blocks 2140 * ========================================================================== 2141 */ 2142static int 2143zio_dva_allocate(zio_t *zio) 2144{ 2145 spa_t *spa = zio->io_spa; 2146 metaslab_class_t *mc = spa_normal_class(spa); 2147 blkptr_t *bp = zio->io_bp; 2148 int error; 2149 int flags = 0; 2150 2151 if (zio->io_gang_leader == NULL) { 2152 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2153 zio->io_gang_leader = zio; 2154 } 2155 2156 ASSERT(BP_IS_HOLE(bp)); 2157 ASSERT3U(BP_GET_NDVAS(bp), ==, 0); 2158 ASSERT3U(zio->io_prop.zp_copies, >, 0); 2159 ASSERT3U(zio->io_prop.zp_copies, <=, spa_max_replication(spa)); 2160 ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp)); 2161 2162 /* 2163 * The dump device does not support gang blocks so allocation on 2164 * behalf of the dump device (i.e. ZIO_FLAG_NODATA) must avoid 2165 * the "fast" gang feature. 2166 */ 2167 flags |= (zio->io_flags & ZIO_FLAG_NODATA) ? METASLAB_GANG_AVOID : 0; 2168 flags |= (zio->io_flags & ZIO_FLAG_GANG_CHILD) ? 2169 METASLAB_GANG_CHILD : 0; 2170 error = metaslab_alloc(spa, mc, zio->io_size, bp, 2171 zio->io_prop.zp_copies, zio->io_txg, NULL, flags); 2172 2173 if (error) { 2174 spa_dbgmsg(spa, "%s: metaslab allocation failure: zio %p, " 2175 "size %llu, error %d", spa_name(spa), zio, zio->io_size, 2176 error); 2177 if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE) 2178 return (zio_write_gang_block(zio)); 2179 zio->io_error = error; 2180 } 2181 2182 return (ZIO_PIPELINE_CONTINUE); 2183} 2184 2185static int 2186zio_dva_free(zio_t *zio) 2187{ 2188 metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE); 2189 2190 return (ZIO_PIPELINE_CONTINUE); 2191} 2192 2193static int 2194zio_dva_claim(zio_t *zio) 2195{ 2196 int error; 2197 2198 error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg); 2199 if (error) 2200 zio->io_error = error; 2201 2202 return (ZIO_PIPELINE_CONTINUE); 2203} 2204 2205/* 2206 * Undo an allocation. This is used by zio_done() when an I/O fails 2207 * and we want to give back the block we just allocated. 2208 * This handles both normal blocks and gang blocks. 2209 */ 2210static void 2211zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp) 2212{ 2213 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp)); 2214 ASSERT(zio->io_bp_override == NULL); 2215 2216 if (!BP_IS_HOLE(bp)) 2217 metaslab_free(zio->io_spa, bp, bp->blk_birth, B_TRUE); 2218 2219 if (gn != NULL) { 2220 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 2221 zio_dva_unallocate(zio, gn->gn_child[g], 2222 &gn->gn_gbh->zg_blkptr[g]); 2223 } 2224 } 2225} 2226 2227/* 2228 * Try to allocate an intent log block. Return 0 on success, errno on failure. 2229 */ 2230int 2231zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp, blkptr_t *old_bp, 2232 uint64_t size, boolean_t use_slog) 2233{ 2234 int error = 1; 2235 2236 ASSERT(txg > spa_syncing_txg(spa)); 2237 2238 /* 2239 * ZIL blocks are always contiguous (i.e. not gang blocks) so we 2240 * set the METASLAB_GANG_AVOID flag so that they don't "fast gang" 2241 * when allocating them. 2242 */ 2243 if (use_slog) { 2244 error = metaslab_alloc(spa, spa_log_class(spa), size, 2245 new_bp, 1, txg, old_bp, 2246 METASLAB_HINTBP_AVOID | METASLAB_GANG_AVOID); 2247 } 2248 2249 if (error) { 2250 error = metaslab_alloc(spa, spa_normal_class(spa), size, 2251 new_bp, 1, txg, old_bp, 2252 METASLAB_HINTBP_AVOID | METASLAB_GANG_AVOID); 2253 } 2254 2255 if (error == 0) { 2256 BP_SET_LSIZE(new_bp, size); 2257 BP_SET_PSIZE(new_bp, size); 2258 BP_SET_COMPRESS(new_bp, ZIO_COMPRESS_OFF); 2259 BP_SET_CHECKSUM(new_bp, 2260 spa_version(spa) >= SPA_VERSION_SLIM_ZIL 2261 ? ZIO_CHECKSUM_ZILOG2 : ZIO_CHECKSUM_ZILOG); 2262 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG); 2263 BP_SET_LEVEL(new_bp, 0); 2264 BP_SET_DEDUP(new_bp, 0); 2265 BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER); 2266 } 2267 2268 return (error); 2269} 2270 2271/* 2272 * Free an intent log block. 2273 */ 2274void 2275zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp) 2276{ 2277 ASSERT(BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG); 2278 ASSERT(!BP_IS_GANG(bp)); 2279 2280 zio_free(spa, txg, bp); 2281} 2282 2283/* 2284 * ========================================================================== 2285 * Read and write to physical devices 2286 * ========================================================================== 2287 */ 2288static int 2289zio_vdev_io_start(zio_t *zio) 2290{ 2291 vdev_t *vd = zio->io_vd; 2292 uint64_t align; 2293 spa_t *spa = zio->io_spa; 2294 2295 ASSERT(zio->io_error == 0); 2296 ASSERT(zio->io_child_error[ZIO_CHILD_VDEV] == 0); 2297 2298 if (vd == NULL) { 2299 if (!(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 2300 spa_config_enter(spa, SCL_ZIO, zio, RW_READER); 2301 2302 /* 2303 * The mirror_ops handle multiple DVAs in a single BP. 2304 */ 2305 return (vdev_mirror_ops.vdev_op_io_start(zio)); 2306 } 2307 2308 /* 2309 * We keep track of time-sensitive I/Os so that the scan thread 2310 * can quickly react to certain workloads. In particular, we care 2311 * about non-scrubbing, top-level reads and writes with the following 2312 * characteristics: 2313 * - synchronous writes of user data to non-slog devices 2314 * - any reads of user data 2315 * When these conditions are met, adjust the timestamp of spa_last_io 2316 * which allows the scan thread to adjust its workload accordingly. 2317 */ 2318 if (!(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && zio->io_bp != NULL && 2319 vd == vd->vdev_top && !vd->vdev_islog && 2320 zio->io_bookmark.zb_objset != DMU_META_OBJSET && 2321 zio->io_txg != spa_syncing_txg(spa)) { 2322 uint64_t old = spa->spa_last_io; 2323 uint64_t new = ddi_get_lbolt64(); 2324 if (old != new) 2325 (void) atomic_cas_64(&spa->spa_last_io, old, new); 2326 } 2327 2328 align = 1ULL << vd->vdev_top->vdev_ashift; 2329 2330 if (P2PHASE(zio->io_size, align) != 0) { 2331 uint64_t asize = P2ROUNDUP(zio->io_size, align); 2332 char *abuf = zio_buf_alloc(asize); 2333 ASSERT(vd == vd->vdev_top); 2334 if (zio->io_type == ZIO_TYPE_WRITE) { 2335 bcopy(zio->io_data, abuf, zio->io_size); 2336 bzero(abuf + zio->io_size, asize - zio->io_size); 2337 } 2338 zio_push_transform(zio, abuf, asize, asize, zio_subblock); 2339 } 2340 2341 ASSERT(P2PHASE(zio->io_offset, align) == 0); 2342 ASSERT(P2PHASE(zio->io_size, align) == 0); 2343 VERIFY(zio->io_type != ZIO_TYPE_WRITE || spa_writeable(spa)); 2344 2345 /* 2346 * If this is a repair I/O, and there's no self-healing involved -- 2347 * that is, we're just resilvering what we expect to resilver -- 2348 * then don't do the I/O unless zio's txg is actually in vd's DTL. 2349 * This prevents spurious resilvering with nested replication. 2350 * For example, given a mirror of mirrors, (A+B)+(C+D), if only 2351 * A is out of date, we'll read from C+D, then use the data to 2352 * resilver A+B -- but we don't actually want to resilver B, just A. 2353 * The top-level mirror has no way to know this, so instead we just 2354 * discard unnecessary repairs as we work our way down the vdev tree. 2355 * The same logic applies to any form of nested replication: 2356 * ditto + mirror, RAID-Z + replacing, etc. This covers them all. 2357 */ 2358 if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) && 2359 !(zio->io_flags & ZIO_FLAG_SELF_HEAL) && 2360 zio->io_txg != 0 && /* not a delegated i/o */ 2361 !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) { 2362 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 2363 zio_vdev_io_bypass(zio); 2364 return (ZIO_PIPELINE_CONTINUE); 2365 } 2366 2367 if (vd->vdev_ops->vdev_op_leaf && 2368 (zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE)) { 2369 2370 if (zio->io_type == ZIO_TYPE_READ && vdev_cache_read(zio) == 0) 2371 return (ZIO_PIPELINE_CONTINUE); 2372 2373 if ((zio = vdev_queue_io(zio)) == NULL) 2374 return (ZIO_PIPELINE_STOP); 2375 2376 if (!vdev_accessible(vd, zio)) { 2377 zio->io_error = ENXIO; 2378 zio_interrupt(zio); 2379 return (ZIO_PIPELINE_STOP); 2380 } 2381 } 2382 2383 return (vd->vdev_ops->vdev_op_io_start(zio)); 2384} 2385 2386static int 2387zio_vdev_io_done(zio_t *zio) 2388{ 2389 vdev_t *vd = zio->io_vd; 2390 vdev_ops_t *ops = vd ? vd->vdev_ops : &vdev_mirror_ops; 2391 boolean_t unexpected_error = B_FALSE; 2392 2393 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 2394 return (ZIO_PIPELINE_STOP); 2395 2396 ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE); 2397 2398 if (vd != NULL && vd->vdev_ops->vdev_op_leaf) { 2399 2400 vdev_queue_io_done(zio); 2401 2402 if (zio->io_type == ZIO_TYPE_WRITE) 2403 vdev_cache_write(zio); 2404 2405 if (zio_injection_enabled && zio->io_error == 0) 2406 zio->io_error = zio_handle_device_injection(vd, 2407 zio, EIO); 2408 2409 if (zio_injection_enabled && zio->io_error == 0) 2410 zio->io_error = zio_handle_label_injection(zio, EIO); 2411 2412 if (zio->io_error) { 2413 if (!vdev_accessible(vd, zio)) { 2414 zio->io_error = ENXIO; 2415 } else { 2416 unexpected_error = B_TRUE; 2417 } 2418 } 2419 } 2420 2421 ops->vdev_op_io_done(zio); 2422 2423 if (unexpected_error) 2424 VERIFY(vdev_probe(vd, zio) == NULL); 2425 2426 return (ZIO_PIPELINE_CONTINUE); 2427} 2428 2429/* 2430 * For non-raidz ZIOs, we can just copy aside the bad data read from the 2431 * disk, and use that to finish the checksum ereport later. 2432 */ 2433static void 2434zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr, 2435 const void *good_buf) 2436{ 2437 /* no processing needed */ 2438 zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE); 2439} 2440 2441/*ARGSUSED*/ 2442void 2443zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *ignored) 2444{ 2445 void *buf = zio_buf_alloc(zio->io_size); 2446 2447 bcopy(zio->io_data, buf, zio->io_size); 2448 2449 zcr->zcr_cbinfo = zio->io_size; 2450 zcr->zcr_cbdata = buf; 2451 zcr->zcr_finish = zio_vsd_default_cksum_finish; 2452 zcr->zcr_free = zio_buf_free; 2453} 2454 2455static int 2456zio_vdev_io_assess(zio_t *zio) 2457{ 2458 vdev_t *vd = zio->io_vd; 2459 2460 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 2461 return (ZIO_PIPELINE_STOP); 2462 2463 if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 2464 spa_config_exit(zio->io_spa, SCL_ZIO, zio); 2465 2466 if (zio->io_vsd != NULL) { 2467 zio->io_vsd_ops->vsd_free(zio); 2468 zio->io_vsd = NULL; 2469 } 2470 2471 if (zio_injection_enabled && zio->io_error == 0) 2472 zio->io_error = zio_handle_fault_injection(zio, EIO); 2473 2474 /* 2475 * If the I/O failed, determine whether we should attempt to retry it. 2476 * 2477 * On retry, we cut in line in the issue queue, since we don't want 2478 * compression/checksumming/etc. work to prevent our (cheap) IO reissue. 2479 */ 2480 if (zio->io_error && vd == NULL && 2481 !(zio->io_flags & (ZIO_FLAG_DONT_RETRY | ZIO_FLAG_IO_RETRY))) { 2482 ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_QUEUE)); /* not a leaf */ 2483 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_BYPASS)); /* not a leaf */ 2484 zio->io_error = 0; 2485 zio->io_flags |= ZIO_FLAG_IO_RETRY | 2486 ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE; 2487 zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1; 2488 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, 2489 zio_requeue_io_start_cut_in_line); 2490 return (ZIO_PIPELINE_STOP); 2491 } 2492 2493 /* 2494 * If we got an error on a leaf device, convert it to ENXIO 2495 * if the device is not accessible at all. 2496 */ 2497 if (zio->io_error && vd != NULL && vd->vdev_ops->vdev_op_leaf && 2498 !vdev_accessible(vd, zio)) 2499 zio->io_error = ENXIO; 2500 2501 /* 2502 * If we can't write to an interior vdev (mirror or RAID-Z), 2503 * set vdev_cant_write so that we stop trying to allocate from it. 2504 */ 2505 if (zio->io_error == ENXIO && zio->io_type == ZIO_TYPE_WRITE && 2506 vd != NULL && !vd->vdev_ops->vdev_op_leaf) 2507 vd->vdev_cant_write = B_TRUE; 2508 2509 if (zio->io_error) 2510 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2511 2512 return (ZIO_PIPELINE_CONTINUE); 2513} 2514 2515void 2516zio_vdev_io_reissue(zio_t *zio) 2517{ 2518 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 2519 ASSERT(zio->io_error == 0); 2520 2521 zio->io_stage >>= 1; 2522} 2523 2524void 2525zio_vdev_io_redone(zio_t *zio) 2526{ 2527 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE); 2528 2529 zio->io_stage >>= 1; 2530} 2531 2532void 2533zio_vdev_io_bypass(zio_t *zio) 2534{ 2535 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 2536 ASSERT(zio->io_error == 0); 2537 2538 zio->io_flags |= ZIO_FLAG_IO_BYPASS; 2539 zio->io_stage = ZIO_STAGE_VDEV_IO_ASSESS >> 1; 2540} 2541 2542/* 2543 * ========================================================================== 2544 * Generate and verify checksums 2545 * ========================================================================== 2546 */ 2547static int 2548zio_checksum_generate(zio_t *zio) 2549{ 2550 blkptr_t *bp = zio->io_bp; 2551 enum zio_checksum checksum; 2552 2553 if (bp == NULL) { 2554 /* 2555 * This is zio_write_phys(). 2556 * We're either generating a label checksum, or none at all. 2557 */ 2558 checksum = zio->io_prop.zp_checksum; 2559 2560 if (checksum == ZIO_CHECKSUM_OFF) 2561 return (ZIO_PIPELINE_CONTINUE); 2562 2563 ASSERT(checksum == ZIO_CHECKSUM_LABEL); 2564 } else { 2565 if (BP_IS_GANG(bp) && zio->io_child_type == ZIO_CHILD_GANG) { 2566 ASSERT(!IO_IS_ALLOCATING(zio)); 2567 checksum = ZIO_CHECKSUM_GANG_HEADER; 2568 } else { 2569 checksum = BP_GET_CHECKSUM(bp); 2570 } 2571 } 2572 2573 zio_checksum_compute(zio, checksum, zio->io_data, zio->io_size); 2574 2575 return (ZIO_PIPELINE_CONTINUE); 2576} 2577 2578static int 2579zio_checksum_verify(zio_t *zio) 2580{ 2581 zio_bad_cksum_t info; 2582 blkptr_t *bp = zio->io_bp; 2583 int error; 2584 2585 ASSERT(zio->io_vd != NULL); 2586 2587 if (bp == NULL) { 2588 /* 2589 * This is zio_read_phys(). 2590 * We're either verifying a label checksum, or nothing at all. 2591 */ 2592 if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF) 2593 return (ZIO_PIPELINE_CONTINUE); 2594 2595 ASSERT(zio->io_prop.zp_checksum == ZIO_CHECKSUM_LABEL); 2596 } 2597 2598 if ((error = zio_checksum_error(zio, &info)) != 0) { 2599 zio->io_error = error; 2600 if (!(zio->io_flags & ZIO_FLAG_SPECULATIVE)) { 2601 zfs_ereport_start_checksum(zio->io_spa, 2602 zio->io_vd, zio, zio->io_offset, 2603 zio->io_size, NULL, &info); 2604 } 2605 } 2606 2607 return (ZIO_PIPELINE_CONTINUE); 2608} 2609 2610/* 2611 * Called by RAID-Z to ensure we don't compute the checksum twice. 2612 */ 2613void 2614zio_checksum_verified(zio_t *zio) 2615{ 2616 zio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 2617} 2618 2619/* 2620 * ========================================================================== 2621 * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other. 2622 * An error of 0 indictes success. ENXIO indicates whole-device failure, 2623 * which may be transient (e.g. unplugged) or permament. ECKSUM and EIO 2624 * indicate errors that are specific to one I/O, and most likely permanent. 2625 * Any other error is presumed to be worse because we weren't expecting it. 2626 * ========================================================================== 2627 */ 2628int 2629zio_worst_error(int e1, int e2) 2630{ 2631 static int zio_error_rank[] = { 0, ENXIO, ECKSUM, EIO }; 2632 int r1, r2; 2633 2634 for (r1 = 0; r1 < sizeof (zio_error_rank) / sizeof (int); r1++) 2635 if (e1 == zio_error_rank[r1]) 2636 break; 2637 2638 for (r2 = 0; r2 < sizeof (zio_error_rank) / sizeof (int); r2++) 2639 if (e2 == zio_error_rank[r2]) 2640 break; 2641 2642 return (r1 > r2 ? e1 : e2); 2643} 2644 2645/* 2646 * ========================================================================== 2647 * I/O completion 2648 * ========================================================================== 2649 */ 2650static int 2651zio_ready(zio_t *zio) 2652{ 2653 blkptr_t *bp = zio->io_bp; 2654 zio_t *pio, *pio_next; 2655 2656 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 2657 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_READY)) 2658 return (ZIO_PIPELINE_STOP); 2659 2660 if (zio->io_ready) { 2661 ASSERT(IO_IS_ALLOCATING(zio)); 2662 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp)); 2663 ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0); 2664 2665 zio->io_ready(zio); 2666 } 2667 2668 if (bp != NULL && bp != &zio->io_bp_copy) 2669 zio->io_bp_copy = *bp; 2670 2671 if (zio->io_error) 2672 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2673 2674 mutex_enter(&zio->io_lock); 2675 zio->io_state[ZIO_WAIT_READY] = 1; 2676 pio = zio_walk_parents(zio); 2677 mutex_exit(&zio->io_lock); 2678 2679 /* 2680 * As we notify zio's parents, new parents could be added. 2681 * New parents go to the head of zio's io_parent_list, however, 2682 * so we will (correctly) not notify them. The remainder of zio's 2683 * io_parent_list, from 'pio_next' onward, cannot change because 2684 * all parents must wait for us to be done before they can be done. 2685 */ 2686 for (; pio != NULL; pio = pio_next) { 2687 pio_next = zio_walk_parents(zio); 2688 zio_notify_parent(pio, zio, ZIO_WAIT_READY); 2689 } 2690 2691 if (zio->io_flags & ZIO_FLAG_NODATA) { 2692 if (BP_IS_GANG(bp)) { 2693 zio->io_flags &= ~ZIO_FLAG_NODATA; 2694 } else { 2695 ASSERT((uintptr_t)zio->io_data < SPA_MAXBLOCKSIZE); 2696 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 2697 } 2698 } 2699 2700 if (zio_injection_enabled && 2701 zio->io_spa->spa_syncing_txg == zio->io_txg) 2702 zio_handle_ignored_writes(zio); 2703 2704 return (ZIO_PIPELINE_CONTINUE); 2705} 2706 2707static int 2708zio_done(zio_t *zio) 2709{ 2710 spa_t *spa = zio->io_spa; 2711 zio_t *lio = zio->io_logical; 2712 blkptr_t *bp = zio->io_bp; 2713 vdev_t *vd = zio->io_vd; 2714 uint64_t psize = zio->io_size; 2715 zio_t *pio, *pio_next; 2716 2717 /* 2718 * If our children haven't all completed, 2719 * wait for them and then repeat this pipeline stage. 2720 */ 2721 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE) || 2722 zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE) || 2723 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE) || 2724 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_DONE)) 2725 return (ZIO_PIPELINE_STOP); 2726 2727 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 2728 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 2729 ASSERT(zio->io_children[c][w] == 0); 2730 2731 if (bp != NULL) { 2732 ASSERT(bp->blk_pad[0] == 0); 2733 ASSERT(bp->blk_pad[1] == 0); 2734 ASSERT(bcmp(bp, &zio->io_bp_copy, sizeof (blkptr_t)) == 0 || 2735 (bp == zio_unique_parent(zio)->io_bp)); 2736 if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(bp) && 2737 zio->io_bp_override == NULL && 2738 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) { 2739 ASSERT(!BP_SHOULD_BYTESWAP(bp)); 2740 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(bp)); 2741 ASSERT(BP_COUNT_GANG(bp) == 0 || 2742 (BP_COUNT_GANG(bp) == BP_GET_NDVAS(bp))); 2743 } 2744 } 2745 2746 /* 2747 * If there were child vdev/gang/ddt errors, they apply to us now. 2748 */ 2749 zio_inherit_child_errors(zio, ZIO_CHILD_VDEV); 2750 zio_inherit_child_errors(zio, ZIO_CHILD_GANG); 2751 zio_inherit_child_errors(zio, ZIO_CHILD_DDT); 2752 2753 /* 2754 * If the I/O on the transformed data was successful, generate any 2755 * checksum reports now while we still have the transformed data. 2756 */ 2757 if (zio->io_error == 0) { 2758 while (zio->io_cksum_report != NULL) { 2759 zio_cksum_report_t *zcr = zio->io_cksum_report; 2760 uint64_t align = zcr->zcr_align; 2761 uint64_t asize = P2ROUNDUP(psize, align); 2762 char *abuf = zio->io_data; 2763 2764 if (asize != psize) { 2765 abuf = zio_buf_alloc(asize); 2766 bcopy(zio->io_data, abuf, psize); 2767 bzero(abuf + psize, asize - psize); 2768 } 2769 2770 zio->io_cksum_report = zcr->zcr_next; 2771 zcr->zcr_next = NULL; 2772 zcr->zcr_finish(zcr, abuf); 2773 zfs_ereport_free_checksum(zcr); 2774 2775 if (asize != psize) 2776 zio_buf_free(abuf, asize); 2777 } 2778 } 2779 2780 zio_pop_transforms(zio); /* note: may set zio->io_error */ 2781 2782 vdev_stat_update(zio, psize); 2783 2784 if (zio->io_error) { 2785 /* 2786 * If this I/O is attached to a particular vdev, 2787 * generate an error message describing the I/O failure 2788 * at the block level. We ignore these errors if the 2789 * device is currently unavailable. 2790 */ 2791 if (zio->io_error != ECKSUM && vd != NULL && !vdev_is_dead(vd)) 2792 zfs_ereport_post(FM_EREPORT_ZFS_IO, spa, vd, zio, 0, 0); 2793 2794 if ((zio->io_error == EIO || !(zio->io_flags & 2795 (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) && 2796 zio == lio) { 2797 /* 2798 * For logical I/O requests, tell the SPA to log the 2799 * error and generate a logical data ereport. 2800 */ 2801 spa_log_error(spa, zio); 2802 zfs_ereport_post(FM_EREPORT_ZFS_DATA, spa, NULL, zio, 2803 0, 0); 2804 } 2805 } 2806 2807 if (zio->io_error && zio == lio) { 2808 /* 2809 * Determine whether zio should be reexecuted. This will 2810 * propagate all the way to the root via zio_notify_parent(). 2811 */ 2812 ASSERT(vd == NULL && bp != NULL); 2813 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2814 2815 if (IO_IS_ALLOCATING(zio) && 2816 !(zio->io_flags & ZIO_FLAG_CANFAIL)) { 2817 if (zio->io_error != ENOSPC) 2818 zio->io_reexecute |= ZIO_REEXECUTE_NOW; 2819 else 2820 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 2821 } 2822 2823 if ((zio->io_type == ZIO_TYPE_READ || 2824 zio->io_type == ZIO_TYPE_FREE) && 2825 !(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && 2826 zio->io_error == ENXIO && 2827 spa_load_state(spa) == SPA_LOAD_NONE && 2828 spa_get_failmode(spa) != ZIO_FAILURE_MODE_CONTINUE) 2829 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 2830 2831 if (!(zio->io_flags & ZIO_FLAG_CANFAIL) && !zio->io_reexecute) 2832 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 2833 2834 /* 2835 * Here is a possibly good place to attempt to do 2836 * either combinatorial reconstruction or error correction 2837 * based on checksums. It also might be a good place 2838 * to send out preliminary ereports before we suspend 2839 * processing. 2840 */ 2841 } 2842 2843 /* 2844 * If there were logical child errors, they apply to us now. 2845 * We defer this until now to avoid conflating logical child 2846 * errors with errors that happened to the zio itself when 2847 * updating vdev stats and reporting FMA events above. 2848 */ 2849 zio_inherit_child_errors(zio, ZIO_CHILD_LOGICAL); 2850 2851 if ((zio->io_error || zio->io_reexecute) && 2852 IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio && 2853 !(zio->io_flags & ZIO_FLAG_IO_REWRITE)) 2854 zio_dva_unallocate(zio, zio->io_gang_tree, bp); 2855 2856 zio_gang_tree_free(&zio->io_gang_tree); 2857 2858 /* 2859 * Godfather I/Os should never suspend. 2860 */ 2861 if ((zio->io_flags & ZIO_FLAG_GODFATHER) && 2862 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) 2863 zio->io_reexecute = 0; 2864 2865 if (zio->io_reexecute) { 2866 /* 2867 * This is a logical I/O that wants to reexecute. 2868 * 2869 * Reexecute is top-down. When an i/o fails, if it's not 2870 * the root, it simply notifies its parent and sticks around. 2871 * The parent, seeing that it still has children in zio_done(), 2872 * does the same. This percolates all the way up to the root. 2873 * The root i/o will reexecute or suspend the entire tree. 2874 * 2875 * This approach ensures that zio_reexecute() honors 2876 * all the original i/o dependency relationships, e.g. 2877 * parents not executing until children are ready. 2878 */ 2879 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2880 2881 zio->io_gang_leader = NULL; 2882 2883 mutex_enter(&zio->io_lock); 2884 zio->io_state[ZIO_WAIT_DONE] = 1; 2885 mutex_exit(&zio->io_lock); 2886 2887 /* 2888 * "The Godfather" I/O monitors its children but is 2889 * not a true parent to them. It will track them through 2890 * the pipeline but severs its ties whenever they get into 2891 * trouble (e.g. suspended). This allows "The Godfather" 2892 * I/O to return status without blocking. 2893 */ 2894 for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) { 2895 zio_link_t *zl = zio->io_walk_link; 2896 pio_next = zio_walk_parents(zio); 2897 2898 if ((pio->io_flags & ZIO_FLAG_GODFATHER) && 2899 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) { 2900 zio_remove_child(pio, zio, zl); 2901 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 2902 } 2903 } 2904 2905 if ((pio = zio_unique_parent(zio)) != NULL) { 2906 /* 2907 * We're not a root i/o, so there's nothing to do 2908 * but notify our parent. Don't propagate errors 2909 * upward since we haven't permanently failed yet. 2910 */ 2911 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 2912 zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE; 2913 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 2914 } else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) { 2915 /* 2916 * We'd fail again if we reexecuted now, so suspend 2917 * until conditions improve (e.g. device comes online). 2918 */ 2919 zio_suspend(spa, zio); 2920 } else { 2921 /* 2922 * Reexecution is potentially a huge amount of work. 2923 * Hand it off to the otherwise-unused claim taskq. 2924 */ 2925#ifdef _KERNEL 2926 (void) taskq_dispatch_safe( 2927 spa->spa_zio_taskq[ZIO_TYPE_CLAIM][ZIO_TASKQ_ISSUE], 2928 (task_func_t *)zio_reexecute, zio, TQ_SLEEP, 2929 &zio->io_task); 2930#else 2931 (void) taskq_dispatch( 2932 spa->spa_zio_taskq[ZIO_TYPE_CLAIM][ZIO_TASKQ_ISSUE], 2933 (task_func_t *)zio_reexecute, zio, TQ_SLEEP); 2934#endif 2935 } 2936 return (ZIO_PIPELINE_STOP); 2937 } 2938 2939 ASSERT(zio->io_child_count == 0); 2940 ASSERT(zio->io_reexecute == 0); 2941 ASSERT(zio->io_error == 0 || (zio->io_flags & ZIO_FLAG_CANFAIL)); 2942 2943 /* 2944 * Report any checksum errors, since the I/O is complete. 2945 */ 2946 while (zio->io_cksum_report != NULL) { 2947 zio_cksum_report_t *zcr = zio->io_cksum_report; 2948 zio->io_cksum_report = zcr->zcr_next; 2949 zcr->zcr_next = NULL; 2950 zcr->zcr_finish(zcr, NULL); 2951 zfs_ereport_free_checksum(zcr); 2952 } 2953 2954 /* 2955 * It is the responsibility of the done callback to ensure that this 2956 * particular zio is no longer discoverable for adoption, and as 2957 * such, cannot acquire any new parents. 2958 */ 2959 if (zio->io_done) 2960 zio->io_done(zio); 2961 2962 mutex_enter(&zio->io_lock); 2963 zio->io_state[ZIO_WAIT_DONE] = 1; 2964 mutex_exit(&zio->io_lock); 2965 2966 for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) { 2967 zio_link_t *zl = zio->io_walk_link; 2968 pio_next = zio_walk_parents(zio); 2969 zio_remove_child(pio, zio, zl); 2970 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 2971 } 2972 2973 if (zio->io_waiter != NULL) { 2974 mutex_enter(&zio->io_lock); 2975 zio->io_executor = NULL; 2976 cv_broadcast(&zio->io_cv); 2977 mutex_exit(&zio->io_lock); 2978 } else { 2979 zio_destroy(zio); 2980 } 2981 2982 return (ZIO_PIPELINE_STOP); 2983} 2984 2985/* 2986 * ========================================================================== 2987 * I/O pipeline definition 2988 * ========================================================================== 2989 */ 2990static zio_pipe_stage_t *zio_pipeline[] = { 2991 NULL, 2992 zio_read_bp_init, 2993 zio_free_bp_init, 2994 zio_issue_async, 2995 zio_write_bp_init, 2996 zio_checksum_generate, 2997 zio_ddt_read_start, 2998 zio_ddt_read_done, 2999 zio_ddt_write, 3000 zio_ddt_free, 3001 zio_gang_assemble, 3002 zio_gang_issue, 3003 zio_dva_allocate, 3004 zio_dva_free, 3005 zio_dva_claim, 3006 zio_ready, 3007 zio_vdev_io_start, 3008 zio_vdev_io_done, 3009 zio_vdev_io_assess, 3010 zio_checksum_verify, 3011 zio_done 3012};
| 246} 247 248void 249zio_buf_free(void *buf, size_t size) 250{ 251 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 252 253 ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 254 255 if (zio_use_uma) 256 kmem_cache_free(zio_buf_cache[c], buf); 257 else 258 kmem_free(buf, size); 259} 260 261void 262zio_data_buf_free(void *buf, size_t size) 263{ 264 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 265 266 ASSERT(c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 267 268 if (zio_use_uma) 269 kmem_cache_free(zio_data_buf_cache[c], buf); 270 else 271 kmem_free(buf, size); 272} 273 274/* 275 * ========================================================================== 276 * Push and pop I/O transform buffers 277 * ========================================================================== 278 */ 279static void 280zio_push_transform(zio_t *zio, void *data, uint64_t size, uint64_t bufsize, 281 zio_transform_func_t *transform) 282{ 283 zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP); 284 285 zt->zt_orig_data = zio->io_data; 286 zt->zt_orig_size = zio->io_size; 287 zt->zt_bufsize = bufsize; 288 zt->zt_transform = transform; 289 290 zt->zt_next = zio->io_transform_stack; 291 zio->io_transform_stack = zt; 292 293 zio->io_data = data; 294 zio->io_size = size; 295} 296 297static void 298zio_pop_transforms(zio_t *zio) 299{ 300 zio_transform_t *zt; 301 302 while ((zt = zio->io_transform_stack) != NULL) { 303 if (zt->zt_transform != NULL) 304 zt->zt_transform(zio, 305 zt->zt_orig_data, zt->zt_orig_size); 306 307 if (zt->zt_bufsize != 0) 308 zio_buf_free(zio->io_data, zt->zt_bufsize); 309 310 zio->io_data = zt->zt_orig_data; 311 zio->io_size = zt->zt_orig_size; 312 zio->io_transform_stack = zt->zt_next; 313 314 kmem_free(zt, sizeof (zio_transform_t)); 315 } 316} 317 318/* 319 * ========================================================================== 320 * I/O transform callbacks for subblocks and decompression 321 * ========================================================================== 322 */ 323static void 324zio_subblock(zio_t *zio, void *data, uint64_t size) 325{ 326 ASSERT(zio->io_size > size); 327 328 if (zio->io_type == ZIO_TYPE_READ) 329 bcopy(zio->io_data, data, size); 330} 331 332static void 333zio_decompress(zio_t *zio, void *data, uint64_t size) 334{ 335 if (zio->io_error == 0 && 336 zio_decompress_data(BP_GET_COMPRESS(zio->io_bp), 337 zio->io_data, data, zio->io_size, size) != 0) 338 zio->io_error = EIO; 339} 340 341/* 342 * ========================================================================== 343 * I/O parent/child relationships and pipeline interlocks 344 * ========================================================================== 345 */ 346/* 347 * NOTE - Callers to zio_walk_parents() and zio_walk_children must 348 * continue calling these functions until they return NULL. 349 * Otherwise, the next caller will pick up the list walk in 350 * some indeterminate state. (Otherwise every caller would 351 * have to pass in a cookie to keep the state represented by 352 * io_walk_link, which gets annoying.) 353 */ 354zio_t * 355zio_walk_parents(zio_t *cio) 356{ 357 zio_link_t *zl = cio->io_walk_link; 358 list_t *pl = &cio->io_parent_list; 359 360 zl = (zl == NULL) ? list_head(pl) : list_next(pl, zl); 361 cio->io_walk_link = zl; 362 363 if (zl == NULL) 364 return (NULL); 365 366 ASSERT(zl->zl_child == cio); 367 return (zl->zl_parent); 368} 369 370zio_t * 371zio_walk_children(zio_t *pio) 372{ 373 zio_link_t *zl = pio->io_walk_link; 374 list_t *cl = &pio->io_child_list; 375 376 zl = (zl == NULL) ? list_head(cl) : list_next(cl, zl); 377 pio->io_walk_link = zl; 378 379 if (zl == NULL) 380 return (NULL); 381 382 ASSERT(zl->zl_parent == pio); 383 return (zl->zl_child); 384} 385 386zio_t * 387zio_unique_parent(zio_t *cio) 388{ 389 zio_t *pio = zio_walk_parents(cio); 390 391 VERIFY(zio_walk_parents(cio) == NULL); 392 return (pio); 393} 394 395void 396zio_add_child(zio_t *pio, zio_t *cio) 397{ 398 zio_link_t *zl = kmem_cache_alloc(zio_link_cache, KM_SLEEP); 399 400 /* 401 * Logical I/Os can have logical, gang, or vdev children. 402 * Gang I/Os can have gang or vdev children. 403 * Vdev I/Os can only have vdev children. 404 * The following ASSERT captures all of these constraints. 405 */ 406 ASSERT(cio->io_child_type <= pio->io_child_type); 407 408 zl->zl_parent = pio; 409 zl->zl_child = cio; 410 411 mutex_enter(&cio->io_lock); 412 mutex_enter(&pio->io_lock); 413 414 ASSERT(pio->io_state[ZIO_WAIT_DONE] == 0); 415 416 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 417 pio->io_children[cio->io_child_type][w] += !cio->io_state[w]; 418 419 list_insert_head(&pio->io_child_list, zl); 420 list_insert_head(&cio->io_parent_list, zl); 421 422 pio->io_child_count++; 423 cio->io_parent_count++; 424 425 mutex_exit(&pio->io_lock); 426 mutex_exit(&cio->io_lock); 427} 428 429static void 430zio_remove_child(zio_t *pio, zio_t *cio, zio_link_t *zl) 431{ 432 ASSERT(zl->zl_parent == pio); 433 ASSERT(zl->zl_child == cio); 434 435 mutex_enter(&cio->io_lock); 436 mutex_enter(&pio->io_lock); 437 438 list_remove(&pio->io_child_list, zl); 439 list_remove(&cio->io_parent_list, zl); 440 441 pio->io_child_count--; 442 cio->io_parent_count--; 443 444 mutex_exit(&pio->io_lock); 445 mutex_exit(&cio->io_lock); 446 447 kmem_cache_free(zio_link_cache, zl); 448} 449 450static boolean_t 451zio_wait_for_children(zio_t *zio, enum zio_child child, enum zio_wait_type wait) 452{ 453 uint64_t *countp = &zio->io_children[child][wait]; 454 boolean_t waiting = B_FALSE; 455 456 mutex_enter(&zio->io_lock); 457 ASSERT(zio->io_stall == NULL); 458 if (*countp != 0) { 459 zio->io_stage >>= 1; 460 zio->io_stall = countp; 461 waiting = B_TRUE; 462 } 463 mutex_exit(&zio->io_lock); 464 465 return (waiting); 466} 467 468static void 469zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait) 470{ 471 uint64_t *countp = &pio->io_children[zio->io_child_type][wait]; 472 int *errorp = &pio->io_child_error[zio->io_child_type]; 473 474 mutex_enter(&pio->io_lock); 475 if (zio->io_error && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE)) 476 *errorp = zio_worst_error(*errorp, zio->io_error); 477 pio->io_reexecute |= zio->io_reexecute; 478 ASSERT3U(*countp, >, 0); 479 if (--*countp == 0 && pio->io_stall == countp) { 480 pio->io_stall = NULL; 481 mutex_exit(&pio->io_lock); 482 zio_execute(pio); 483 } else { 484 mutex_exit(&pio->io_lock); 485 } 486} 487 488static void 489zio_inherit_child_errors(zio_t *zio, enum zio_child c) 490{ 491 if (zio->io_child_error[c] != 0 && zio->io_error == 0) 492 zio->io_error = zio->io_child_error[c]; 493} 494 495/* 496 * ========================================================================== 497 * Create the various types of I/O (read, write, free, etc) 498 * ========================================================================== 499 */ 500static zio_t * 501zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 502 void *data, uint64_t size, zio_done_func_t *done, void *private, 503 zio_type_t type, int priority, enum zio_flag flags, 504 vdev_t *vd, uint64_t offset, const zbookmark_t *zb, 505 enum zio_stage stage, enum zio_stage pipeline) 506{ 507 zio_t *zio; 508 509 ASSERT3U(size, <=, SPA_MAXBLOCKSIZE); 510 ASSERT(P2PHASE(size, SPA_MINBLOCKSIZE) == 0); 511 ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0); 512 513 ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER)); 514 ASSERT(!bp || !(flags & ZIO_FLAG_CONFIG_WRITER)); 515 ASSERT(vd || stage == ZIO_STAGE_OPEN); 516 517 zio = kmem_cache_alloc(zio_cache, KM_SLEEP); 518 bzero(zio, sizeof (zio_t)); 519 520 mutex_init(&zio->io_lock, NULL, MUTEX_DEFAULT, NULL); 521 cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL); 522 523 list_create(&zio->io_parent_list, sizeof (zio_link_t), 524 offsetof(zio_link_t, zl_parent_node)); 525 list_create(&zio->io_child_list, sizeof (zio_link_t), 526 offsetof(zio_link_t, zl_child_node)); 527 528 if (vd != NULL) 529 zio->io_child_type = ZIO_CHILD_VDEV; 530 else if (flags & ZIO_FLAG_GANG_CHILD) 531 zio->io_child_type = ZIO_CHILD_GANG; 532 else if (flags & ZIO_FLAG_DDT_CHILD) 533 zio->io_child_type = ZIO_CHILD_DDT; 534 else 535 zio->io_child_type = ZIO_CHILD_LOGICAL; 536 537 if (bp != NULL) { 538 zio->io_bp = (blkptr_t *)bp; 539 zio->io_bp_copy = *bp; 540 zio->io_bp_orig = *bp; 541 if (type != ZIO_TYPE_WRITE || 542 zio->io_child_type == ZIO_CHILD_DDT) 543 zio->io_bp = &zio->io_bp_copy; /* so caller can free */ 544 if (zio->io_child_type == ZIO_CHILD_LOGICAL) 545 zio->io_logical = zio; 546 if (zio->io_child_type > ZIO_CHILD_GANG && BP_IS_GANG(bp)) 547 pipeline |= ZIO_GANG_STAGES; 548 } 549 550 zio->io_spa = spa; 551 zio->io_txg = txg; 552 zio->io_done = done; 553 zio->io_private = private; 554 zio->io_type = type; 555 zio->io_priority = priority; 556 zio->io_vd = vd; 557 zio->io_offset = offset; 558 zio->io_orig_data = zio->io_data = data; 559 zio->io_orig_size = zio->io_size = size; 560 zio->io_orig_flags = zio->io_flags = flags; 561 zio->io_orig_stage = zio->io_stage = stage; 562 zio->io_orig_pipeline = zio->io_pipeline = pipeline; 563 564 zio->io_state[ZIO_WAIT_READY] = (stage >= ZIO_STAGE_READY); 565 zio->io_state[ZIO_WAIT_DONE] = (stage >= ZIO_STAGE_DONE); 566 567 if (zb != NULL) 568 zio->io_bookmark = *zb; 569 570 if (pio != NULL) { 571 if (zio->io_logical == NULL) 572 zio->io_logical = pio->io_logical; 573 if (zio->io_child_type == ZIO_CHILD_GANG) 574 zio->io_gang_leader = pio->io_gang_leader; 575 zio_add_child(pio, zio); 576 } 577 578 return (zio); 579} 580 581static void 582zio_destroy(zio_t *zio) 583{ 584 list_destroy(&zio->io_parent_list); 585 list_destroy(&zio->io_child_list); 586 mutex_destroy(&zio->io_lock); 587 cv_destroy(&zio->io_cv); 588 kmem_cache_free(zio_cache, zio); 589} 590 591zio_t * 592zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, zio_done_func_t *done, 593 void *private, enum zio_flag flags) 594{ 595 zio_t *zio; 596 597 zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private, 598 ZIO_TYPE_NULL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL, 599 ZIO_STAGE_OPEN, ZIO_INTERLOCK_PIPELINE); 600 601 return (zio); 602} 603 604zio_t * 605zio_root(spa_t *spa, zio_done_func_t *done, void *private, enum zio_flag flags) 606{ 607 return (zio_null(NULL, spa, NULL, done, private, flags)); 608} 609 610zio_t * 611zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, 612 void *data, uint64_t size, zio_done_func_t *done, void *private, 613 int priority, enum zio_flag flags, const zbookmark_t *zb) 614{ 615 zio_t *zio; 616 617 zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp, 618 data, size, done, private, 619 ZIO_TYPE_READ, priority, flags, NULL, 0, zb, 620 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 621 ZIO_DDT_CHILD_READ_PIPELINE : ZIO_READ_PIPELINE); 622 623 return (zio); 624} 625 626zio_t * 627zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, 628 void *data, uint64_t size, const zio_prop_t *zp, 629 zio_done_func_t *ready, zio_done_func_t *done, void *private, 630 int priority, enum zio_flag flags, const zbookmark_t *zb) 631{ 632 zio_t *zio; 633 634 ASSERT(zp->zp_checksum >= ZIO_CHECKSUM_OFF && 635 zp->zp_checksum < ZIO_CHECKSUM_FUNCTIONS && 636 zp->zp_compress >= ZIO_COMPRESS_OFF && 637 zp->zp_compress < ZIO_COMPRESS_FUNCTIONS && 638 zp->zp_type < DMU_OT_NUMTYPES && 639 zp->zp_level < 32 && 640 zp->zp_copies > 0 && 641 zp->zp_copies <= spa_max_replication(spa) && 642 zp->zp_dedup <= 1 && 643 zp->zp_dedup_verify <= 1); 644 645 zio = zio_create(pio, spa, txg, bp, data, size, done, private, 646 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 647 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 648 ZIO_DDT_CHILD_WRITE_PIPELINE : ZIO_WRITE_PIPELINE); 649 650 zio->io_ready = ready; 651 zio->io_prop = *zp; 652 653 return (zio); 654} 655 656zio_t * 657zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, void *data, 658 uint64_t size, zio_done_func_t *done, void *private, int priority, 659 enum zio_flag flags, zbookmark_t *zb) 660{ 661 zio_t *zio; 662 663 zio = zio_create(pio, spa, txg, bp, data, size, done, private, 664 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 665 ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE); 666 667 return (zio); 668} 669 670void 671zio_write_override(zio_t *zio, blkptr_t *bp, int copies) 672{ 673 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 674 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 675 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 676 ASSERT(zio->io_txg == spa_syncing_txg(zio->io_spa)); 677 678 zio->io_prop.zp_copies = copies; 679 zio->io_bp_override = bp; 680} 681 682void 683zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp) 684{ 685 bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp); 686} 687 688zio_t * 689zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 690 enum zio_flag flags) 691{ 692 zio_t *zio; 693 694 dprintf_bp(bp, "freeing in txg %llu, pass %u", 695 (longlong_t)txg, spa->spa_sync_pass); 696 697 ASSERT(!BP_IS_HOLE(bp)); 698 ASSERT(spa_syncing_txg(spa) == txg); 699 ASSERT(spa_sync_pass(spa) <= SYNC_PASS_DEFERRED_FREE); 700 701 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 702 NULL, NULL, ZIO_TYPE_FREE, ZIO_PRIORITY_FREE, flags, 703 NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_FREE_PIPELINE); 704 705 return (zio); 706} 707 708zio_t * 709zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 710 zio_done_func_t *done, void *private, enum zio_flag flags) 711{ 712 zio_t *zio; 713 714 /* 715 * A claim is an allocation of a specific block. Claims are needed 716 * to support immediate writes in the intent log. The issue is that 717 * immediate writes contain committed data, but in a txg that was 718 * *not* committed. Upon opening the pool after an unclean shutdown, 719 * the intent log claims all blocks that contain immediate write data 720 * so that the SPA knows they're in use. 721 * 722 * All claims *must* be resolved in the first txg -- before the SPA 723 * starts allocating blocks -- so that nothing is allocated twice. 724 * If txg == 0 we just verify that the block is claimable. 725 */ 726 ASSERT3U(spa->spa_uberblock.ub_rootbp.blk_birth, <, spa_first_txg(spa)); 727 ASSERT(txg == spa_first_txg(spa) || txg == 0); 728 ASSERT(!BP_GET_DEDUP(bp) || !spa_writeable(spa)); /* zdb(1M) */ 729 730 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 731 done, private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW, flags, 732 NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE); 733 734 return (zio); 735} 736 737zio_t * 738zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd, 739 zio_done_func_t *done, void *private, int priority, enum zio_flag flags) 740{ 741 zio_t *zio; 742 int c; 743 744 if (vd->vdev_children == 0) { 745 zio = zio_create(pio, spa, 0, NULL, NULL, 0, done, private, 746 ZIO_TYPE_IOCTL, priority, flags, vd, 0, NULL, 747 ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE); 748 749 zio->io_cmd = cmd; 750 } else { 751 zio = zio_null(pio, spa, NULL, NULL, NULL, flags); 752 753 for (c = 0; c < vd->vdev_children; c++) 754 zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd, 755 done, private, priority, flags)); 756 } 757 758 return (zio); 759} 760 761zio_t * 762zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 763 void *data, int checksum, zio_done_func_t *done, void *private, 764 int priority, enum zio_flag flags, boolean_t labels) 765{ 766 zio_t *zio; 767 768 ASSERT(vd->vdev_children == 0); 769 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 770 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 771 ASSERT3U(offset + size, <=, vd->vdev_psize); 772 773 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private, 774 ZIO_TYPE_READ, priority, flags, vd, offset, NULL, 775 ZIO_STAGE_OPEN, ZIO_READ_PHYS_PIPELINE); 776 777 zio->io_prop.zp_checksum = checksum; 778 779 return (zio); 780} 781 782zio_t * 783zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 784 void *data, int checksum, zio_done_func_t *done, void *private, 785 int priority, enum zio_flag flags, boolean_t labels) 786{ 787 zio_t *zio; 788 789 ASSERT(vd->vdev_children == 0); 790 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 791 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 792 ASSERT3U(offset + size, <=, vd->vdev_psize); 793 794 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, done, private, 795 ZIO_TYPE_WRITE, priority, flags, vd, offset, NULL, 796 ZIO_STAGE_OPEN, ZIO_WRITE_PHYS_PIPELINE); 797 798 zio->io_prop.zp_checksum = checksum; 799 800 if (zio_checksum_table[checksum].ci_eck) { 801 /* 802 * zec checksums are necessarily destructive -- they modify 803 * the end of the write buffer to hold the verifier/checksum. 804 * Therefore, we must make a local copy in case the data is 805 * being written to multiple places in parallel. 806 */ 807 void *wbuf = zio_buf_alloc(size); 808 bcopy(data, wbuf, size); 809 zio_push_transform(zio, wbuf, size, size, NULL); 810 } 811 812 return (zio); 813} 814 815/* 816 * Create a child I/O to do some work for us. 817 */ 818zio_t * 819zio_vdev_child_io(zio_t *pio, blkptr_t *bp, vdev_t *vd, uint64_t offset, 820 void *data, uint64_t size, int type, int priority, enum zio_flag flags, 821 zio_done_func_t *done, void *private) 822{ 823 enum zio_stage pipeline = ZIO_VDEV_CHILD_PIPELINE; 824 zio_t *zio; 825 826 ASSERT(vd->vdev_parent == 827 (pio->io_vd ? pio->io_vd : pio->io_spa->spa_root_vdev)); 828 829 if (type == ZIO_TYPE_READ && bp != NULL) { 830 /* 831 * If we have the bp, then the child should perform the 832 * checksum and the parent need not. This pushes error 833 * detection as close to the leaves as possible and 834 * eliminates redundant checksums in the interior nodes. 835 */ 836 pipeline |= ZIO_STAGE_CHECKSUM_VERIFY; 837 pio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 838 } 839 840 if (vd->vdev_children == 0) 841 offset += VDEV_LABEL_START_SIZE; 842 843 flags |= ZIO_VDEV_CHILD_FLAGS(pio) | ZIO_FLAG_DONT_PROPAGATE; 844 845 /* 846 * If we've decided to do a repair, the write is not speculative -- 847 * even if the original read was. 848 */ 849 if (flags & ZIO_FLAG_IO_REPAIR) 850 flags &= ~ZIO_FLAG_SPECULATIVE; 851 852 zio = zio_create(pio, pio->io_spa, pio->io_txg, bp, data, size, 853 done, private, type, priority, flags, vd, offset, &pio->io_bookmark, 854 ZIO_STAGE_VDEV_IO_START >> 1, pipeline); 855 856 return (zio); 857} 858 859zio_t * 860zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, void *data, uint64_t size, 861 int type, int priority, enum zio_flag flags, 862 zio_done_func_t *done, void *private) 863{ 864 zio_t *zio; 865 866 ASSERT(vd->vdev_ops->vdev_op_leaf); 867 868 zio = zio_create(NULL, vd->vdev_spa, 0, NULL, 869 data, size, done, private, type, priority, 870 flags | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY, 871 vd, offset, NULL, 872 ZIO_STAGE_VDEV_IO_START >> 1, ZIO_VDEV_CHILD_PIPELINE); 873 874 return (zio); 875} 876 877void 878zio_flush(zio_t *zio, vdev_t *vd) 879{ 880 zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE, 881 NULL, NULL, ZIO_PRIORITY_NOW, 882 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY)); 883} 884 885void 886zio_shrink(zio_t *zio, uint64_t size) 887{ 888 ASSERT(zio->io_executor == NULL); 889 ASSERT(zio->io_orig_size == zio->io_size); 890 ASSERT(size <= zio->io_size); 891 892 /* 893 * We don't shrink for raidz because of problems with the 894 * reconstruction when reading back less than the block size. 895 * Note, BP_IS_RAIDZ() assumes no compression. 896 */ 897 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 898 if (!BP_IS_RAIDZ(zio->io_bp)) 899 zio->io_orig_size = zio->io_size = size; 900} 901 902/* 903 * ========================================================================== 904 * Prepare to read and write logical blocks 905 * ========================================================================== 906 */ 907 908static int 909zio_read_bp_init(zio_t *zio) 910{ 911 blkptr_t *bp = zio->io_bp; 912 913 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF && 914 zio->io_child_type == ZIO_CHILD_LOGICAL && 915 !(zio->io_flags & ZIO_FLAG_RAW)) { 916 uint64_t psize = BP_GET_PSIZE(bp); 917 void *cbuf = zio_buf_alloc(psize); 918 919 zio_push_transform(zio, cbuf, psize, psize, zio_decompress); 920 } 921 922 if (!dmu_ot[BP_GET_TYPE(bp)].ot_metadata && BP_GET_LEVEL(bp) == 0) 923 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 924 925 if (BP_GET_TYPE(bp) == DMU_OT_DDT_ZAP) 926 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 927 928 if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL) 929 zio->io_pipeline = ZIO_DDT_READ_PIPELINE; 930 931 return (ZIO_PIPELINE_CONTINUE); 932} 933 934static int 935zio_write_bp_init(zio_t *zio) 936{ 937 spa_t *spa = zio->io_spa; 938 zio_prop_t *zp = &zio->io_prop; 939 enum zio_compress compress = zp->zp_compress; 940 blkptr_t *bp = zio->io_bp; 941 uint64_t lsize = zio->io_size; 942 uint64_t psize = lsize; 943 int pass = 1; 944 945 /* 946 * If our children haven't all reached the ready stage, 947 * wait for them and then repeat this pipeline stage. 948 */ 949 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 950 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_READY)) 951 return (ZIO_PIPELINE_STOP); 952 953 if (!IO_IS_ALLOCATING(zio)) 954 return (ZIO_PIPELINE_CONTINUE); 955 956 ASSERT(zio->io_child_type != ZIO_CHILD_DDT); 957 958 if (zio->io_bp_override) { 959 ASSERT(bp->blk_birth != zio->io_txg); 960 ASSERT(BP_GET_DEDUP(zio->io_bp_override) == 0); 961 962 *bp = *zio->io_bp_override; 963 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 964 965 if (BP_IS_HOLE(bp) || !zp->zp_dedup) 966 return (ZIO_PIPELINE_CONTINUE); 967 968 ASSERT(zio_checksum_table[zp->zp_checksum].ci_dedup || 969 zp->zp_dedup_verify); 970 971 if (BP_GET_CHECKSUM(bp) == zp->zp_checksum) { 972 BP_SET_DEDUP(bp, 1); 973 zio->io_pipeline |= ZIO_STAGE_DDT_WRITE; 974 return (ZIO_PIPELINE_CONTINUE); 975 } 976 zio->io_bp_override = NULL; 977 BP_ZERO(bp); 978 } 979 980 if (bp->blk_birth == zio->io_txg) { 981 /* 982 * We're rewriting an existing block, which means we're 983 * working on behalf of spa_sync(). For spa_sync() to 984 * converge, it must eventually be the case that we don't 985 * have to allocate new blocks. But compression changes 986 * the blocksize, which forces a reallocate, and makes 987 * convergence take longer. Therefore, after the first 988 * few passes, stop compressing to ensure convergence. 989 */ 990 pass = spa_sync_pass(spa); 991 992 ASSERT(zio->io_txg == spa_syncing_txg(spa)); 993 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 994 ASSERT(!BP_GET_DEDUP(bp)); 995 996 if (pass > SYNC_PASS_DONT_COMPRESS) 997 compress = ZIO_COMPRESS_OFF; 998 999 /* Make sure someone doesn't change their mind on overwrites */ 1000 ASSERT(MIN(zp->zp_copies + BP_IS_GANG(bp), 1001 spa_max_replication(spa)) == BP_GET_NDVAS(bp)); 1002 } 1003 1004 if (compress != ZIO_COMPRESS_OFF) { 1005 void *cbuf = zio_buf_alloc(lsize); 1006 psize = zio_compress_data(compress, zio->io_data, cbuf, lsize); 1007 if (psize == 0 || psize == lsize) { 1008 compress = ZIO_COMPRESS_OFF; 1009 zio_buf_free(cbuf, lsize); 1010 } else { 1011 ASSERT(psize < lsize); 1012 zio_push_transform(zio, cbuf, psize, lsize, NULL); 1013 } 1014 } 1015 1016 /* 1017 * The final pass of spa_sync() must be all rewrites, but the first 1018 * few passes offer a trade-off: allocating blocks defers convergence, 1019 * but newly allocated blocks are sequential, so they can be written 1020 * to disk faster. Therefore, we allow the first few passes of 1021 * spa_sync() to allocate new blocks, but force rewrites after that. 1022 * There should only be a handful of blocks after pass 1 in any case. 1023 */ 1024 if (bp->blk_birth == zio->io_txg && BP_GET_PSIZE(bp) == psize && 1025 pass > SYNC_PASS_REWRITE) { 1026 ASSERT(psize != 0); 1027 enum zio_stage gang_stages = zio->io_pipeline & ZIO_GANG_STAGES; 1028 zio->io_pipeline = ZIO_REWRITE_PIPELINE | gang_stages; 1029 zio->io_flags |= ZIO_FLAG_IO_REWRITE; 1030 } else { 1031 BP_ZERO(bp); 1032 zio->io_pipeline = ZIO_WRITE_PIPELINE; 1033 } 1034 1035 if (psize == 0) { 1036 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1037 } else { 1038 ASSERT(zp->zp_checksum != ZIO_CHECKSUM_GANG_HEADER); 1039 BP_SET_LSIZE(bp, lsize); 1040 BP_SET_PSIZE(bp, psize); 1041 BP_SET_COMPRESS(bp, compress); 1042 BP_SET_CHECKSUM(bp, zp->zp_checksum); 1043 BP_SET_TYPE(bp, zp->zp_type); 1044 BP_SET_LEVEL(bp, zp->zp_level); 1045 BP_SET_DEDUP(bp, zp->zp_dedup); 1046 BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER); 1047 if (zp->zp_dedup) { 1048 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1049 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1050 zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE; 1051 } 1052 } 1053 1054 return (ZIO_PIPELINE_CONTINUE); 1055} 1056 1057static int 1058zio_free_bp_init(zio_t *zio) 1059{ 1060 blkptr_t *bp = zio->io_bp; 1061 1062 if (zio->io_child_type == ZIO_CHILD_LOGICAL) { 1063 if (BP_GET_DEDUP(bp)) 1064 zio->io_pipeline = ZIO_DDT_FREE_PIPELINE; 1065 } 1066 1067 return (ZIO_PIPELINE_CONTINUE); 1068} 1069 1070/* 1071 * ========================================================================== 1072 * Execute the I/O pipeline 1073 * ========================================================================== 1074 */ 1075 1076static void 1077zio_taskq_dispatch(zio_t *zio, enum zio_taskq_type q, boolean_t cutinline) 1078{ 1079 spa_t *spa = zio->io_spa; 1080 zio_type_t t = zio->io_type; 1081 int flags = TQ_SLEEP | (cutinline ? TQ_FRONT : 0); 1082 1083 ASSERT(q == ZIO_TASKQ_ISSUE || q == ZIO_TASKQ_INTERRUPT); 1084 1085 /* 1086 * If we're a config writer or a probe, the normal issue and 1087 * interrupt threads may all be blocked waiting for the config lock. 1088 * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL. 1089 */ 1090 if (zio->io_flags & (ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_PROBE)) 1091 t = ZIO_TYPE_NULL; 1092 1093 /* 1094 * A similar issue exists for the L2ARC write thread until L2ARC 2.0. 1095 */ 1096 if (t == ZIO_TYPE_WRITE && zio->io_vd && zio->io_vd->vdev_aux) 1097 t = ZIO_TYPE_NULL; 1098 1099 /* 1100 * If this is a high priority I/O, then use the high priority taskq. 1101 */ 1102 if (zio->io_priority == ZIO_PRIORITY_NOW && 1103 spa->spa_zio_taskq[t][q + 1] != NULL) 1104 q++; 1105 1106 ASSERT3U(q, <, ZIO_TASKQ_TYPES); 1107#ifdef _KERNEL 1108 (void) taskq_dispatch_safe(spa->spa_zio_taskq[t][q], 1109 (task_func_t *)zio_execute, zio, flags, &zio->io_task); 1110#else 1111 (void) taskq_dispatch(spa->spa_zio_taskq[t][q], 1112 (task_func_t *)zio_execute, zio, flags); 1113#endif 1114} 1115 1116static boolean_t 1117zio_taskq_member(zio_t *zio, enum zio_taskq_type q) 1118{ 1119 kthread_t *executor = zio->io_executor; 1120 spa_t *spa = zio->io_spa; 1121 1122 for (zio_type_t t = 0; t < ZIO_TYPES; t++) 1123 if (taskq_member(spa->spa_zio_taskq[t][q], executor)) 1124 return (B_TRUE); 1125 1126 return (B_FALSE); 1127} 1128 1129static int 1130zio_issue_async(zio_t *zio) 1131{ 1132 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 1133 1134 return (ZIO_PIPELINE_STOP); 1135} 1136 1137void 1138zio_interrupt(zio_t *zio) 1139{ 1140 zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE); 1141} 1142 1143/* 1144 * Execute the I/O pipeline until one of the following occurs: 1145 * (1) the I/O completes; (2) the pipeline stalls waiting for 1146 * dependent child I/Os; (3) the I/O issues, so we're waiting 1147 * for an I/O completion interrupt; (4) the I/O is delegated by 1148 * vdev-level caching or aggregation; (5) the I/O is deferred 1149 * due to vdev-level queueing; (6) the I/O is handed off to 1150 * another thread. In all cases, the pipeline stops whenever 1151 * there's no CPU work; it never burns a thread in cv_wait(). 1152 * 1153 * There's no locking on io_stage because there's no legitimate way 1154 * for multiple threads to be attempting to process the same I/O. 1155 */ 1156static zio_pipe_stage_t *zio_pipeline[]; 1157 1158void 1159zio_execute(zio_t *zio) 1160{ 1161 zio->io_executor = curthread; 1162 1163 while (zio->io_stage < ZIO_STAGE_DONE) { 1164 enum zio_stage pipeline = zio->io_pipeline; 1165 enum zio_stage stage = zio->io_stage; 1166 int rv; 1167 1168 ASSERT(!MUTEX_HELD(&zio->io_lock)); 1169 ASSERT(ISP2(stage)); 1170 ASSERT(zio->io_stall == NULL); 1171 1172 do { 1173 stage <<= 1; 1174 } while ((stage & pipeline) == 0); 1175 1176 ASSERT(stage <= ZIO_STAGE_DONE); 1177 1178 /* 1179 * If we are in interrupt context and this pipeline stage 1180 * will grab a config lock that is held across I/O, 1181 * or may wait for an I/O that needs an interrupt thread 1182 * to complete, issue async to avoid deadlock. 1183 * 1184 * For VDEV_IO_START, we cut in line so that the io will 1185 * be sent to disk promptly. 1186 */ 1187 if ((stage & ZIO_BLOCKING_STAGES) && zio->io_vd == NULL && 1188 zio_taskq_member(zio, ZIO_TASKQ_INTERRUPT)) { 1189 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ? 1190 zio_requeue_io_start_cut_in_line : B_FALSE; 1191 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut); 1192 return; 1193 } 1194 1195 zio->io_stage = stage; 1196 rv = zio_pipeline[highbit(stage) - 1](zio); 1197 1198 if (rv == ZIO_PIPELINE_STOP) 1199 return; 1200 1201 ASSERT(rv == ZIO_PIPELINE_CONTINUE); 1202 } 1203} 1204 1205/* 1206 * ========================================================================== 1207 * Initiate I/O, either sync or async 1208 * ========================================================================== 1209 */ 1210int 1211zio_wait(zio_t *zio) 1212{ 1213 int error; 1214 1215 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 1216 ASSERT(zio->io_executor == NULL); 1217 1218 zio->io_waiter = curthread; 1219 1220 zio_execute(zio); 1221 1222 mutex_enter(&zio->io_lock); 1223 while (zio->io_executor != NULL) 1224 cv_wait(&zio->io_cv, &zio->io_lock); 1225 mutex_exit(&zio->io_lock); 1226 1227 error = zio->io_error; 1228 zio_destroy(zio); 1229 1230 return (error); 1231} 1232 1233void 1234zio_nowait(zio_t *zio) 1235{ 1236 ASSERT(zio->io_executor == NULL); 1237 1238 if (zio->io_child_type == ZIO_CHILD_LOGICAL && 1239 zio_unique_parent(zio) == NULL) { 1240 /* 1241 * This is a logical async I/O with no parent to wait for it. 1242 * We add it to the spa_async_root_zio "Godfather" I/O which 1243 * will ensure they complete prior to unloading the pool. 1244 */ 1245 spa_t *spa = zio->io_spa; 1246 1247 zio_add_child(spa->spa_async_zio_root, zio); 1248 } 1249 1250 zio_execute(zio); 1251} 1252 1253/* 1254 * ========================================================================== 1255 * Reexecute or suspend/resume failed I/O 1256 * ========================================================================== 1257 */ 1258 1259static void 1260zio_reexecute(zio_t *pio) 1261{ 1262 zio_t *cio, *cio_next; 1263 1264 ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL); 1265 ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN); 1266 ASSERT(pio->io_gang_leader == NULL); 1267 ASSERT(pio->io_gang_tree == NULL); 1268 1269 pio->io_flags = pio->io_orig_flags; 1270 pio->io_stage = pio->io_orig_stage; 1271 pio->io_pipeline = pio->io_orig_pipeline; 1272 pio->io_reexecute = 0; 1273 pio->io_error = 0; 1274 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1275 pio->io_state[w] = 0; 1276 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 1277 pio->io_child_error[c] = 0; 1278 1279 if (IO_IS_ALLOCATING(pio)) 1280 BP_ZERO(pio->io_bp); 1281 1282 /* 1283 * As we reexecute pio's children, new children could be created. 1284 * New children go to the head of pio's io_child_list, however, 1285 * so we will (correctly) not reexecute them. The key is that 1286 * the remainder of pio's io_child_list, from 'cio_next' onward, 1287 * cannot be affected by any side effects of reexecuting 'cio'. 1288 */ 1289 for (cio = zio_walk_children(pio); cio != NULL; cio = cio_next) { 1290 cio_next = zio_walk_children(pio); 1291 mutex_enter(&pio->io_lock); 1292 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 1293 pio->io_children[cio->io_child_type][w]++; 1294 mutex_exit(&pio->io_lock); 1295 zio_reexecute(cio); 1296 } 1297 1298 /* 1299 * Now that all children have been reexecuted, execute the parent. 1300 * We don't reexecute "The Godfather" I/O here as it's the 1301 * responsibility of the caller to wait on him. 1302 */ 1303 if (!(pio->io_flags & ZIO_FLAG_GODFATHER)) 1304 zio_execute(pio); 1305} 1306 1307void 1308zio_suspend(spa_t *spa, zio_t *zio) 1309{ 1310 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC) 1311 fm_panic("Pool '%s' has encountered an uncorrectable I/O " 1312 "failure and the failure mode property for this pool " 1313 "is set to panic.", spa_name(spa)); 1314 1315 zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL, NULL, 0, 0); 1316 1317 mutex_enter(&spa->spa_suspend_lock); 1318 1319 if (spa->spa_suspend_zio_root == NULL) 1320 spa->spa_suspend_zio_root = zio_root(spa, NULL, NULL, 1321 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | 1322 ZIO_FLAG_GODFATHER); 1323 1324 spa->spa_suspended = B_TRUE; 1325 1326 if (zio != NULL) { 1327 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 1328 ASSERT(zio != spa->spa_suspend_zio_root); 1329 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1330 ASSERT(zio_unique_parent(zio) == NULL); 1331 ASSERT(zio->io_stage == ZIO_STAGE_DONE); 1332 zio_add_child(spa->spa_suspend_zio_root, zio); 1333 } 1334 1335 mutex_exit(&spa->spa_suspend_lock); 1336} 1337 1338int 1339zio_resume(spa_t *spa) 1340{ 1341 zio_t *pio; 1342 1343 /* 1344 * Reexecute all previously suspended i/o. 1345 */ 1346 mutex_enter(&spa->spa_suspend_lock); 1347 spa->spa_suspended = B_FALSE; 1348 cv_broadcast(&spa->spa_suspend_cv); 1349 pio = spa->spa_suspend_zio_root; 1350 spa->spa_suspend_zio_root = NULL; 1351 mutex_exit(&spa->spa_suspend_lock); 1352 1353 if (pio == NULL) 1354 return (0); 1355 1356 zio_reexecute(pio); 1357 return (zio_wait(pio)); 1358} 1359 1360void 1361zio_resume_wait(spa_t *spa) 1362{ 1363 mutex_enter(&spa->spa_suspend_lock); 1364 while (spa_suspended(spa)) 1365 cv_wait(&spa->spa_suspend_cv, &spa->spa_suspend_lock); 1366 mutex_exit(&spa->spa_suspend_lock); 1367} 1368 1369/* 1370 * ========================================================================== 1371 * Gang blocks. 1372 * 1373 * A gang block is a collection of small blocks that looks to the DMU 1374 * like one large block. When zio_dva_allocate() cannot find a block 1375 * of the requested size, due to either severe fragmentation or the pool 1376 * being nearly full, it calls zio_write_gang_block() to construct the 1377 * block from smaller fragments. 1378 * 1379 * A gang block consists of a gang header (zio_gbh_phys_t) and up to 1380 * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like 1381 * an indirect block: it's an array of block pointers. It consumes 1382 * only one sector and hence is allocatable regardless of fragmentation. 1383 * The gang header's bps point to its gang members, which hold the data. 1384 * 1385 * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg> 1386 * as the verifier to ensure uniqueness of the SHA256 checksum. 1387 * Critically, the gang block bp's blk_cksum is the checksum of the data, 1388 * not the gang header. This ensures that data block signatures (needed for 1389 * deduplication) are independent of how the block is physically stored. 1390 * 1391 * Gang blocks can be nested: a gang member may itself be a gang block. 1392 * Thus every gang block is a tree in which root and all interior nodes are 1393 * gang headers, and the leaves are normal blocks that contain user data. 1394 * The root of the gang tree is called the gang leader. 1395 * 1396 * To perform any operation (read, rewrite, free, claim) on a gang block, 1397 * zio_gang_assemble() first assembles the gang tree (minus data leaves) 1398 * in the io_gang_tree field of the original logical i/o by recursively 1399 * reading the gang leader and all gang headers below it. This yields 1400 * an in-core tree containing the contents of every gang header and the 1401 * bps for every constituent of the gang block. 1402 * 1403 * With the gang tree now assembled, zio_gang_issue() just walks the gang tree 1404 * and invokes a callback on each bp. To free a gang block, zio_gang_issue() 1405 * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp. 1406 * zio_claim_gang() provides a similarly trivial wrapper for zio_claim(). 1407 * zio_read_gang() is a wrapper around zio_read() that omits reading gang 1408 * headers, since we already have those in io_gang_tree. zio_rewrite_gang() 1409 * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite() 1410 * of the gang header plus zio_checksum_compute() of the data to update the 1411 * gang header's blk_cksum as described above. 1412 * 1413 * The two-phase assemble/issue model solves the problem of partial failure -- 1414 * what if you'd freed part of a gang block but then couldn't read the 1415 * gang header for another part? Assembling the entire gang tree first 1416 * ensures that all the necessary gang header I/O has succeeded before 1417 * starting the actual work of free, claim, or write. Once the gang tree 1418 * is assembled, free and claim are in-memory operations that cannot fail. 1419 * 1420 * In the event that a gang write fails, zio_dva_unallocate() walks the 1421 * gang tree to immediately free (i.e. insert back into the space map) 1422 * everything we've allocated. This ensures that we don't get ENOSPC 1423 * errors during repeated suspend/resume cycles due to a flaky device. 1424 * 1425 * Gang rewrites only happen during sync-to-convergence. If we can't assemble 1426 * the gang tree, we won't modify the block, so we can safely defer the free 1427 * (knowing that the block is still intact). If we *can* assemble the gang 1428 * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free 1429 * each constituent bp and we can allocate a new block on the next sync pass. 1430 * 1431 * In all cases, the gang tree allows complete recovery from partial failure. 1432 * ========================================================================== 1433 */ 1434 1435static zio_t * 1436zio_read_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1437{ 1438 if (gn != NULL) 1439 return (pio); 1440 1441 return (zio_read(pio, pio->io_spa, bp, data, BP_GET_PSIZE(bp), 1442 NULL, NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 1443 &pio->io_bookmark)); 1444} 1445 1446zio_t * 1447zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1448{ 1449 zio_t *zio; 1450 1451 if (gn != NULL) { 1452 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1453 gn->gn_gbh, SPA_GANGBLOCKSIZE, NULL, NULL, pio->io_priority, 1454 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1455 /* 1456 * As we rewrite each gang header, the pipeline will compute 1457 * a new gang block header checksum for it; but no one will 1458 * compute a new data checksum, so we do that here. The one 1459 * exception is the gang leader: the pipeline already computed 1460 * its data checksum because that stage precedes gang assembly. 1461 * (Presently, nothing actually uses interior data checksums; 1462 * this is just good hygiene.) 1463 */ 1464 if (gn != pio->io_gang_leader->io_gang_tree) { 1465 zio_checksum_compute(zio, BP_GET_CHECKSUM(bp), 1466 data, BP_GET_PSIZE(bp)); 1467 } 1468 /* 1469 * If we are here to damage data for testing purposes, 1470 * leave the GBH alone so that we can detect the damage. 1471 */ 1472 if (pio->io_gang_leader->io_flags & ZIO_FLAG_INDUCE_DAMAGE) 1473 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 1474 } else { 1475 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 1476 data, BP_GET_PSIZE(bp), NULL, NULL, pio->io_priority, 1477 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1478 } 1479 1480 return (zio); 1481} 1482 1483/* ARGSUSED */ 1484zio_t * 1485zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1486{ 1487 return (zio_free_sync(pio, pio->io_spa, pio->io_txg, bp, 1488 ZIO_GANG_CHILD_FLAGS(pio))); 1489} 1490 1491/* ARGSUSED */ 1492zio_t * 1493zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, void *data) 1494{ 1495 return (zio_claim(pio, pio->io_spa, pio->io_txg, bp, 1496 NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio))); 1497} 1498 1499static zio_gang_issue_func_t *zio_gang_issue_func[ZIO_TYPES] = { 1500 NULL, 1501 zio_read_gang, 1502 zio_rewrite_gang, 1503 zio_free_gang, 1504 zio_claim_gang, 1505 NULL 1506}; 1507 1508static void zio_gang_tree_assemble_done(zio_t *zio); 1509 1510static zio_gang_node_t * 1511zio_gang_node_alloc(zio_gang_node_t **gnpp) 1512{ 1513 zio_gang_node_t *gn; 1514 1515 ASSERT(*gnpp == NULL); 1516 1517 gn = kmem_zalloc(sizeof (*gn), KM_SLEEP); 1518 gn->gn_gbh = zio_buf_alloc(SPA_GANGBLOCKSIZE); 1519 *gnpp = gn; 1520 1521 return (gn); 1522} 1523 1524static void 1525zio_gang_node_free(zio_gang_node_t **gnpp) 1526{ 1527 zio_gang_node_t *gn = *gnpp; 1528 1529 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 1530 ASSERT(gn->gn_child[g] == NULL); 1531 1532 zio_buf_free(gn->gn_gbh, SPA_GANGBLOCKSIZE); 1533 kmem_free(gn, sizeof (*gn)); 1534 *gnpp = NULL; 1535} 1536 1537static void 1538zio_gang_tree_free(zio_gang_node_t **gnpp) 1539{ 1540 zio_gang_node_t *gn = *gnpp; 1541 1542 if (gn == NULL) 1543 return; 1544 1545 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 1546 zio_gang_tree_free(&gn->gn_child[g]); 1547 1548 zio_gang_node_free(gnpp); 1549} 1550 1551static void 1552zio_gang_tree_assemble(zio_t *gio, blkptr_t *bp, zio_gang_node_t **gnpp) 1553{ 1554 zio_gang_node_t *gn = zio_gang_node_alloc(gnpp); 1555 1556 ASSERT(gio->io_gang_leader == gio); 1557 ASSERT(BP_IS_GANG(bp)); 1558 1559 zio_nowait(zio_read(gio, gio->io_spa, bp, gn->gn_gbh, 1560 SPA_GANGBLOCKSIZE, zio_gang_tree_assemble_done, gn, 1561 gio->io_priority, ZIO_GANG_CHILD_FLAGS(gio), &gio->io_bookmark)); 1562} 1563 1564static void 1565zio_gang_tree_assemble_done(zio_t *zio) 1566{ 1567 zio_t *gio = zio->io_gang_leader; 1568 zio_gang_node_t *gn = zio->io_private; 1569 blkptr_t *bp = zio->io_bp; 1570 1571 ASSERT(gio == zio_unique_parent(zio)); 1572 ASSERT(zio->io_child_count == 0); 1573 1574 if (zio->io_error) 1575 return; 1576 1577 if (BP_SHOULD_BYTESWAP(bp)) 1578 byteswap_uint64_array(zio->io_data, zio->io_size); 1579 1580 ASSERT(zio->io_data == gn->gn_gbh); 1581 ASSERT(zio->io_size == SPA_GANGBLOCKSIZE); 1582 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 1583 1584 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 1585 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 1586 if (!BP_IS_GANG(gbp)) 1587 continue; 1588 zio_gang_tree_assemble(gio, gbp, &gn->gn_child[g]); 1589 } 1590} 1591 1592static void 1593zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, void *data) 1594{ 1595 zio_t *gio = pio->io_gang_leader; 1596 zio_t *zio; 1597 1598 ASSERT(BP_IS_GANG(bp) == !!gn); 1599 ASSERT(BP_GET_CHECKSUM(bp) == BP_GET_CHECKSUM(gio->io_bp)); 1600 ASSERT(BP_GET_LSIZE(bp) == BP_GET_PSIZE(bp) || gn == gio->io_gang_tree); 1601 1602 /* 1603 * If you're a gang header, your data is in gn->gn_gbh. 1604 * If you're a gang member, your data is in 'data' and gn == NULL. 1605 */ 1606 zio = zio_gang_issue_func[gio->io_type](pio, bp, gn, data); 1607 1608 if (gn != NULL) { 1609 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 1610 1611 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 1612 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 1613 if (BP_IS_HOLE(gbp)) 1614 continue; 1615 zio_gang_tree_issue(zio, gn->gn_child[g], gbp, data); 1616 data = (char *)data + BP_GET_PSIZE(gbp); 1617 } 1618 } 1619 1620 if (gn == gio->io_gang_tree) 1621 ASSERT3P((char *)gio->io_data + gio->io_size, ==, data); 1622 1623 if (zio != pio) 1624 zio_nowait(zio); 1625} 1626 1627static int 1628zio_gang_assemble(zio_t *zio) 1629{ 1630 blkptr_t *bp = zio->io_bp; 1631 1632 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == NULL); 1633 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 1634 1635 zio->io_gang_leader = zio; 1636 1637 zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree); 1638 1639 return (ZIO_PIPELINE_CONTINUE); 1640} 1641 1642static int 1643zio_gang_issue(zio_t *zio) 1644{ 1645 blkptr_t *bp = zio->io_bp; 1646 1647 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE)) 1648 return (ZIO_PIPELINE_STOP); 1649 1650 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio); 1651 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 1652 1653 if (zio->io_child_error[ZIO_CHILD_GANG] == 0) 1654 zio_gang_tree_issue(zio, zio->io_gang_tree, bp, zio->io_data); 1655 else 1656 zio_gang_tree_free(&zio->io_gang_tree); 1657 1658 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1659 1660 return (ZIO_PIPELINE_CONTINUE); 1661} 1662 1663static void 1664zio_write_gang_member_ready(zio_t *zio) 1665{ 1666 zio_t *pio = zio_unique_parent(zio); 1667 zio_t *gio = zio->io_gang_leader; 1668 dva_t *cdva = zio->io_bp->blk_dva; 1669 dva_t *pdva = pio->io_bp->blk_dva; 1670 uint64_t asize; 1671 1672 if (BP_IS_HOLE(zio->io_bp)) 1673 return; 1674 1675 ASSERT(BP_IS_HOLE(&zio->io_bp_orig)); 1676 1677 ASSERT(zio->io_child_type == ZIO_CHILD_GANG); 1678 ASSERT3U(zio->io_prop.zp_copies, ==, gio->io_prop.zp_copies); 1679 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp)); 1680 ASSERT3U(pio->io_prop.zp_copies, <=, BP_GET_NDVAS(pio->io_bp)); 1681 ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp)); 1682 1683 mutex_enter(&pio->io_lock); 1684 for (int d = 0; d < BP_GET_NDVAS(zio->io_bp); d++) { 1685 ASSERT(DVA_GET_GANG(&pdva[d])); 1686 asize = DVA_GET_ASIZE(&pdva[d]); 1687 asize += DVA_GET_ASIZE(&cdva[d]); 1688 DVA_SET_ASIZE(&pdva[d], asize); 1689 } 1690 mutex_exit(&pio->io_lock); 1691} 1692 1693static int 1694zio_write_gang_block(zio_t *pio) 1695{ 1696 spa_t *spa = pio->io_spa; 1697 blkptr_t *bp = pio->io_bp; 1698 zio_t *gio = pio->io_gang_leader; 1699 zio_t *zio; 1700 zio_gang_node_t *gn, **gnpp; 1701 zio_gbh_phys_t *gbh; 1702 uint64_t txg = pio->io_txg; 1703 uint64_t resid = pio->io_size; 1704 uint64_t lsize; 1705 int copies = gio->io_prop.zp_copies; 1706 int gbh_copies = MIN(copies + 1, spa_max_replication(spa)); 1707 zio_prop_t zp; 1708 int error; 1709 1710 error = metaslab_alloc(spa, spa_normal_class(spa), SPA_GANGBLOCKSIZE, 1711 bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp, 1712 METASLAB_HINTBP_FAVOR | METASLAB_GANG_HEADER); 1713 if (error) { 1714 pio->io_error = error; 1715 return (ZIO_PIPELINE_CONTINUE); 1716 } 1717 1718 if (pio == gio) { 1719 gnpp = &gio->io_gang_tree; 1720 } else { 1721 gnpp = pio->io_private; 1722 ASSERT(pio->io_ready == zio_write_gang_member_ready); 1723 } 1724 1725 gn = zio_gang_node_alloc(gnpp); 1726 gbh = gn->gn_gbh; 1727 bzero(gbh, SPA_GANGBLOCKSIZE); 1728 1729 /* 1730 * Create the gang header. 1731 */ 1732 zio = zio_rewrite(pio, spa, txg, bp, gbh, SPA_GANGBLOCKSIZE, NULL, NULL, 1733 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 1734 1735 /* 1736 * Create and nowait the gang children. 1737 */ 1738 for (int g = 0; resid != 0; resid -= lsize, g++) { 1739 lsize = P2ROUNDUP(resid / (SPA_GBH_NBLKPTRS - g), 1740 SPA_MINBLOCKSIZE); 1741 ASSERT(lsize >= SPA_MINBLOCKSIZE && lsize <= resid); 1742 1743 zp.zp_checksum = gio->io_prop.zp_checksum; 1744 zp.zp_compress = ZIO_COMPRESS_OFF; 1745 zp.zp_type = DMU_OT_NONE; 1746 zp.zp_level = 0; 1747 zp.zp_copies = gio->io_prop.zp_copies; 1748 zp.zp_dedup = 0; 1749 zp.zp_dedup_verify = 0; 1750 1751 zio_nowait(zio_write(zio, spa, txg, &gbh->zg_blkptr[g], 1752 (char *)pio->io_data + (pio->io_size - resid), lsize, &zp, 1753 zio_write_gang_member_ready, NULL, &gn->gn_child[g], 1754 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 1755 &pio->io_bookmark)); 1756 } 1757 1758 /* 1759 * Set pio's pipeline to just wait for zio to finish. 1760 */ 1761 pio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1762 1763 zio_nowait(zio); 1764 1765 return (ZIO_PIPELINE_CONTINUE); 1766} 1767 1768/* 1769 * ========================================================================== 1770 * Dedup 1771 * ========================================================================== 1772 */ 1773static void 1774zio_ddt_child_read_done(zio_t *zio) 1775{ 1776 blkptr_t *bp = zio->io_bp; 1777 ddt_entry_t *dde = zio->io_private; 1778 ddt_phys_t *ddp; 1779 zio_t *pio = zio_unique_parent(zio); 1780 1781 mutex_enter(&pio->io_lock); 1782 ddp = ddt_phys_select(dde, bp); 1783 if (zio->io_error == 0) 1784 ddt_phys_clear(ddp); /* this ddp doesn't need repair */ 1785 if (zio->io_error == 0 && dde->dde_repair_data == NULL) 1786 dde->dde_repair_data = zio->io_data; 1787 else 1788 zio_buf_free(zio->io_data, zio->io_size); 1789 mutex_exit(&pio->io_lock); 1790} 1791 1792static int 1793zio_ddt_read_start(zio_t *zio) 1794{ 1795 blkptr_t *bp = zio->io_bp; 1796 1797 ASSERT(BP_GET_DEDUP(bp)); 1798 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 1799 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1800 1801 if (zio->io_child_error[ZIO_CHILD_DDT]) { 1802 ddt_t *ddt = ddt_select(zio->io_spa, bp); 1803 ddt_entry_t *dde = ddt_repair_start(ddt, bp); 1804 ddt_phys_t *ddp = dde->dde_phys; 1805 ddt_phys_t *ddp_self = ddt_phys_select(dde, bp); 1806 blkptr_t blk; 1807 1808 ASSERT(zio->io_vsd == NULL); 1809 zio->io_vsd = dde; 1810 1811 if (ddp_self == NULL) 1812 return (ZIO_PIPELINE_CONTINUE); 1813 1814 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { 1815 if (ddp->ddp_phys_birth == 0 || ddp == ddp_self) 1816 continue; 1817 ddt_bp_create(ddt->ddt_checksum, &dde->dde_key, ddp, 1818 &blk); 1819 zio_nowait(zio_read(zio, zio->io_spa, &blk, 1820 zio_buf_alloc(zio->io_size), zio->io_size, 1821 zio_ddt_child_read_done, dde, zio->io_priority, 1822 ZIO_DDT_CHILD_FLAGS(zio) | ZIO_FLAG_DONT_PROPAGATE, 1823 &zio->io_bookmark)); 1824 } 1825 return (ZIO_PIPELINE_CONTINUE); 1826 } 1827 1828 zio_nowait(zio_read(zio, zio->io_spa, bp, 1829 zio->io_data, zio->io_size, NULL, NULL, zio->io_priority, 1830 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark)); 1831 1832 return (ZIO_PIPELINE_CONTINUE); 1833} 1834 1835static int 1836zio_ddt_read_done(zio_t *zio) 1837{ 1838 blkptr_t *bp = zio->io_bp; 1839 1840 if (zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE)) 1841 return (ZIO_PIPELINE_STOP); 1842 1843 ASSERT(BP_GET_DEDUP(bp)); 1844 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 1845 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1846 1847 if (zio->io_child_error[ZIO_CHILD_DDT]) { 1848 ddt_t *ddt = ddt_select(zio->io_spa, bp); 1849 ddt_entry_t *dde = zio->io_vsd; 1850 if (ddt == NULL) { 1851 ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE); 1852 return (ZIO_PIPELINE_CONTINUE); 1853 } 1854 if (dde == NULL) { 1855 zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1; 1856 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 1857 return (ZIO_PIPELINE_STOP); 1858 } 1859 if (dde->dde_repair_data != NULL) { 1860 bcopy(dde->dde_repair_data, zio->io_data, zio->io_size); 1861 zio->io_child_error[ZIO_CHILD_DDT] = 0; 1862 } 1863 ddt_repair_done(ddt, dde); 1864 zio->io_vsd = NULL; 1865 } 1866 1867 ASSERT(zio->io_vsd == NULL); 1868 1869 return (ZIO_PIPELINE_CONTINUE); 1870} 1871 1872static boolean_t 1873zio_ddt_collision(zio_t *zio, ddt_t *ddt, ddt_entry_t *dde) 1874{ 1875 spa_t *spa = zio->io_spa; 1876 1877 /* 1878 * Note: we compare the original data, not the transformed data, 1879 * because when zio->io_bp is an override bp, we will not have 1880 * pushed the I/O transforms. That's an important optimization 1881 * because otherwise we'd compress/encrypt all dmu_sync() data twice. 1882 */ 1883 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 1884 zio_t *lio = dde->dde_lead_zio[p]; 1885 1886 if (lio != NULL) { 1887 return (lio->io_orig_size != zio->io_orig_size || 1888 bcmp(zio->io_orig_data, lio->io_orig_data, 1889 zio->io_orig_size) != 0); 1890 } 1891 } 1892 1893 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 1894 ddt_phys_t *ddp = &dde->dde_phys[p]; 1895 1896 if (ddp->ddp_phys_birth != 0) { 1897 arc_buf_t *abuf = NULL; 1898 uint32_t aflags = ARC_WAIT; 1899 blkptr_t blk = *zio->io_bp; 1900 int error; 1901 1902 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth); 1903 1904 ddt_exit(ddt); 1905 1906 error = arc_read_nolock(NULL, spa, &blk, 1907 arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ, 1908 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, 1909 &aflags, &zio->io_bookmark); 1910 1911 if (error == 0) { 1912 if (arc_buf_size(abuf) != zio->io_orig_size || 1913 bcmp(abuf->b_data, zio->io_orig_data, 1914 zio->io_orig_size) != 0) 1915 error = EEXIST; 1916 VERIFY(arc_buf_remove_ref(abuf, &abuf) == 1); 1917 } 1918 1919 ddt_enter(ddt); 1920 return (error != 0); 1921 } 1922 } 1923 1924 return (B_FALSE); 1925} 1926 1927static void 1928zio_ddt_child_write_ready(zio_t *zio) 1929{ 1930 int p = zio->io_prop.zp_copies; 1931 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 1932 ddt_entry_t *dde = zio->io_private; 1933 ddt_phys_t *ddp = &dde->dde_phys[p]; 1934 zio_t *pio; 1935 1936 if (zio->io_error) 1937 return; 1938 1939 ddt_enter(ddt); 1940 1941 ASSERT(dde->dde_lead_zio[p] == zio); 1942 1943 ddt_phys_fill(ddp, zio->io_bp); 1944 1945 while ((pio = zio_walk_parents(zio)) != NULL) 1946 ddt_bp_fill(ddp, pio->io_bp, zio->io_txg); 1947 1948 ddt_exit(ddt); 1949} 1950 1951static void 1952zio_ddt_child_write_done(zio_t *zio) 1953{ 1954 int p = zio->io_prop.zp_copies; 1955 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 1956 ddt_entry_t *dde = zio->io_private; 1957 ddt_phys_t *ddp = &dde->dde_phys[p]; 1958 1959 ddt_enter(ddt); 1960 1961 ASSERT(ddp->ddp_refcnt == 0); 1962 ASSERT(dde->dde_lead_zio[p] == zio); 1963 dde->dde_lead_zio[p] = NULL; 1964 1965 if (zio->io_error == 0) { 1966 while (zio_walk_parents(zio) != NULL) 1967 ddt_phys_addref(ddp); 1968 } else { 1969 ddt_phys_clear(ddp); 1970 } 1971 1972 ddt_exit(ddt); 1973} 1974 1975static void 1976zio_ddt_ditto_write_done(zio_t *zio) 1977{ 1978 int p = DDT_PHYS_DITTO; 1979 zio_prop_t *zp = &zio->io_prop; 1980 blkptr_t *bp = zio->io_bp; 1981 ddt_t *ddt = ddt_select(zio->io_spa, bp); 1982 ddt_entry_t *dde = zio->io_private; 1983 ddt_phys_t *ddp = &dde->dde_phys[p]; 1984 ddt_key_t *ddk = &dde->dde_key; 1985 1986 ddt_enter(ddt); 1987 1988 ASSERT(ddp->ddp_refcnt == 0); 1989 ASSERT(dde->dde_lead_zio[p] == zio); 1990 dde->dde_lead_zio[p] = NULL; 1991 1992 if (zio->io_error == 0) { 1993 ASSERT(ZIO_CHECKSUM_EQUAL(bp->blk_cksum, ddk->ddk_cksum)); 1994 ASSERT(zp->zp_copies < SPA_DVAS_PER_BP); 1995 ASSERT(zp->zp_copies == BP_GET_NDVAS(bp) - BP_IS_GANG(bp)); 1996 if (ddp->ddp_phys_birth != 0) 1997 ddt_phys_free(ddt, ddk, ddp, zio->io_txg); 1998 ddt_phys_fill(ddp, bp); 1999 } 2000 2001 ddt_exit(ddt); 2002} 2003 2004static int 2005zio_ddt_write(zio_t *zio) 2006{ 2007 spa_t *spa = zio->io_spa; 2008 blkptr_t *bp = zio->io_bp; 2009 uint64_t txg = zio->io_txg; 2010 zio_prop_t *zp = &zio->io_prop; 2011 int p = zp->zp_copies; 2012 int ditto_copies; 2013 zio_t *cio = NULL; 2014 zio_t *dio = NULL; 2015 ddt_t *ddt = ddt_select(spa, bp); 2016 ddt_entry_t *dde; 2017 ddt_phys_t *ddp; 2018 2019 ASSERT(BP_GET_DEDUP(bp)); 2020 ASSERT(BP_GET_CHECKSUM(bp) == zp->zp_checksum); 2021 ASSERT(BP_IS_HOLE(bp) || zio->io_bp_override); 2022 2023 ddt_enter(ddt); 2024 dde = ddt_lookup(ddt, bp, B_TRUE); 2025 ddp = &dde->dde_phys[p]; 2026 2027 if (zp->zp_dedup_verify && zio_ddt_collision(zio, ddt, dde)) { 2028 /* 2029 * If we're using a weak checksum, upgrade to a strong checksum 2030 * and try again. If we're already using a strong checksum, 2031 * we can't resolve it, so just convert to an ordinary write. 2032 * (And automatically e-mail a paper to Nature?) 2033 */ 2034 if (!zio_checksum_table[zp->zp_checksum].ci_dedup) { 2035 zp->zp_checksum = spa_dedup_checksum(spa); 2036 zio_pop_transforms(zio); 2037 zio->io_stage = ZIO_STAGE_OPEN; 2038 BP_ZERO(bp); 2039 } else { 2040 zp->zp_dedup = 0; 2041 } 2042 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2043 ddt_exit(ddt); 2044 return (ZIO_PIPELINE_CONTINUE); 2045 } 2046 2047 ditto_copies = ddt_ditto_copies_needed(ddt, dde, ddp); 2048 ASSERT(ditto_copies < SPA_DVAS_PER_BP); 2049 2050 if (ditto_copies > ddt_ditto_copies_present(dde) && 2051 dde->dde_lead_zio[DDT_PHYS_DITTO] == NULL) { 2052 zio_prop_t czp = *zp; 2053 2054 czp.zp_copies = ditto_copies; 2055 2056 /* 2057 * If we arrived here with an override bp, we won't have run 2058 * the transform stack, so we won't have the data we need to 2059 * generate a child i/o. So, toss the override bp and restart. 2060 * This is safe, because using the override bp is just an 2061 * optimization; and it's rare, so the cost doesn't matter. 2062 */ 2063 if (zio->io_bp_override) { 2064 zio_pop_transforms(zio); 2065 zio->io_stage = ZIO_STAGE_OPEN; 2066 zio->io_pipeline = ZIO_WRITE_PIPELINE; 2067 zio->io_bp_override = NULL; 2068 BP_ZERO(bp); 2069 ddt_exit(ddt); 2070 return (ZIO_PIPELINE_CONTINUE); 2071 } 2072 2073 dio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2074 zio->io_orig_size, &czp, NULL, 2075 zio_ddt_ditto_write_done, dde, zio->io_priority, 2076 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2077 2078 zio_push_transform(dio, zio->io_data, zio->io_size, 0, NULL); 2079 dde->dde_lead_zio[DDT_PHYS_DITTO] = dio; 2080 } 2081 2082 if (ddp->ddp_phys_birth != 0 || dde->dde_lead_zio[p] != NULL) { 2083 if (ddp->ddp_phys_birth != 0) 2084 ddt_bp_fill(ddp, bp, txg); 2085 if (dde->dde_lead_zio[p] != NULL) 2086 zio_add_child(zio, dde->dde_lead_zio[p]); 2087 else 2088 ddt_phys_addref(ddp); 2089 } else if (zio->io_bp_override) { 2090 ASSERT(bp->blk_birth == txg); 2091 ASSERT(BP_EQUAL(bp, zio->io_bp_override)); 2092 ddt_phys_fill(ddp, bp); 2093 ddt_phys_addref(ddp); 2094 } else { 2095 cio = zio_write(zio, spa, txg, bp, zio->io_orig_data, 2096 zio->io_orig_size, zp, zio_ddt_child_write_ready, 2097 zio_ddt_child_write_done, dde, zio->io_priority, 2098 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 2099 2100 zio_push_transform(cio, zio->io_data, zio->io_size, 0, NULL); 2101 dde->dde_lead_zio[p] = cio; 2102 } 2103 2104 ddt_exit(ddt); 2105 2106 if (cio) 2107 zio_nowait(cio); 2108 if (dio) 2109 zio_nowait(dio); 2110 2111 return (ZIO_PIPELINE_CONTINUE); 2112} 2113 2114ddt_entry_t *freedde; /* for debugging */ 2115 2116static int 2117zio_ddt_free(zio_t *zio) 2118{ 2119 spa_t *spa = zio->io_spa; 2120 blkptr_t *bp = zio->io_bp; 2121 ddt_t *ddt = ddt_select(spa, bp); 2122 ddt_entry_t *dde; 2123 ddt_phys_t *ddp; 2124 2125 ASSERT(BP_GET_DEDUP(bp)); 2126 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2127 2128 ddt_enter(ddt); 2129 freedde = dde = ddt_lookup(ddt, bp, B_TRUE); 2130 ddp = ddt_phys_select(dde, bp); 2131 ddt_phys_decref(ddp); 2132 ddt_exit(ddt); 2133 2134 return (ZIO_PIPELINE_CONTINUE); 2135} 2136 2137/* 2138 * ========================================================================== 2139 * Allocate and free blocks 2140 * ========================================================================== 2141 */ 2142static int 2143zio_dva_allocate(zio_t *zio) 2144{ 2145 spa_t *spa = zio->io_spa; 2146 metaslab_class_t *mc = spa_normal_class(spa); 2147 blkptr_t *bp = zio->io_bp; 2148 int error; 2149 int flags = 0; 2150 2151 if (zio->io_gang_leader == NULL) { 2152 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2153 zio->io_gang_leader = zio; 2154 } 2155 2156 ASSERT(BP_IS_HOLE(bp)); 2157 ASSERT3U(BP_GET_NDVAS(bp), ==, 0); 2158 ASSERT3U(zio->io_prop.zp_copies, >, 0); 2159 ASSERT3U(zio->io_prop.zp_copies, <=, spa_max_replication(spa)); 2160 ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp)); 2161 2162 /* 2163 * The dump device does not support gang blocks so allocation on 2164 * behalf of the dump device (i.e. ZIO_FLAG_NODATA) must avoid 2165 * the "fast" gang feature. 2166 */ 2167 flags |= (zio->io_flags & ZIO_FLAG_NODATA) ? METASLAB_GANG_AVOID : 0; 2168 flags |= (zio->io_flags & ZIO_FLAG_GANG_CHILD) ? 2169 METASLAB_GANG_CHILD : 0; 2170 error = metaslab_alloc(spa, mc, zio->io_size, bp, 2171 zio->io_prop.zp_copies, zio->io_txg, NULL, flags); 2172 2173 if (error) { 2174 spa_dbgmsg(spa, "%s: metaslab allocation failure: zio %p, " 2175 "size %llu, error %d", spa_name(spa), zio, zio->io_size, 2176 error); 2177 if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE) 2178 return (zio_write_gang_block(zio)); 2179 zio->io_error = error; 2180 } 2181 2182 return (ZIO_PIPELINE_CONTINUE); 2183} 2184 2185static int 2186zio_dva_free(zio_t *zio) 2187{ 2188 metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE); 2189 2190 return (ZIO_PIPELINE_CONTINUE); 2191} 2192 2193static int 2194zio_dva_claim(zio_t *zio) 2195{ 2196 int error; 2197 2198 error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg); 2199 if (error) 2200 zio->io_error = error; 2201 2202 return (ZIO_PIPELINE_CONTINUE); 2203} 2204 2205/* 2206 * Undo an allocation. This is used by zio_done() when an I/O fails 2207 * and we want to give back the block we just allocated. 2208 * This handles both normal blocks and gang blocks. 2209 */ 2210static void 2211zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp) 2212{ 2213 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp)); 2214 ASSERT(zio->io_bp_override == NULL); 2215 2216 if (!BP_IS_HOLE(bp)) 2217 metaslab_free(zio->io_spa, bp, bp->blk_birth, B_TRUE); 2218 2219 if (gn != NULL) { 2220 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 2221 zio_dva_unallocate(zio, gn->gn_child[g], 2222 &gn->gn_gbh->zg_blkptr[g]); 2223 } 2224 } 2225} 2226 2227/* 2228 * Try to allocate an intent log block. Return 0 on success, errno on failure. 2229 */ 2230int 2231zio_alloc_zil(spa_t *spa, uint64_t txg, blkptr_t *new_bp, blkptr_t *old_bp, 2232 uint64_t size, boolean_t use_slog) 2233{ 2234 int error = 1; 2235 2236 ASSERT(txg > spa_syncing_txg(spa)); 2237 2238 /* 2239 * ZIL blocks are always contiguous (i.e. not gang blocks) so we 2240 * set the METASLAB_GANG_AVOID flag so that they don't "fast gang" 2241 * when allocating them. 2242 */ 2243 if (use_slog) { 2244 error = metaslab_alloc(spa, spa_log_class(spa), size, 2245 new_bp, 1, txg, old_bp, 2246 METASLAB_HINTBP_AVOID | METASLAB_GANG_AVOID); 2247 } 2248 2249 if (error) { 2250 error = metaslab_alloc(spa, spa_normal_class(spa), size, 2251 new_bp, 1, txg, old_bp, 2252 METASLAB_HINTBP_AVOID | METASLAB_GANG_AVOID); 2253 } 2254 2255 if (error == 0) { 2256 BP_SET_LSIZE(new_bp, size); 2257 BP_SET_PSIZE(new_bp, size); 2258 BP_SET_COMPRESS(new_bp, ZIO_COMPRESS_OFF); 2259 BP_SET_CHECKSUM(new_bp, 2260 spa_version(spa) >= SPA_VERSION_SLIM_ZIL 2261 ? ZIO_CHECKSUM_ZILOG2 : ZIO_CHECKSUM_ZILOG); 2262 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG); 2263 BP_SET_LEVEL(new_bp, 0); 2264 BP_SET_DEDUP(new_bp, 0); 2265 BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER); 2266 } 2267 2268 return (error); 2269} 2270 2271/* 2272 * Free an intent log block. 2273 */ 2274void 2275zio_free_zil(spa_t *spa, uint64_t txg, blkptr_t *bp) 2276{ 2277 ASSERT(BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG); 2278 ASSERT(!BP_IS_GANG(bp)); 2279 2280 zio_free(spa, txg, bp); 2281} 2282 2283/* 2284 * ========================================================================== 2285 * Read and write to physical devices 2286 * ========================================================================== 2287 */ 2288static int 2289zio_vdev_io_start(zio_t *zio) 2290{ 2291 vdev_t *vd = zio->io_vd; 2292 uint64_t align; 2293 spa_t *spa = zio->io_spa; 2294 2295 ASSERT(zio->io_error == 0); 2296 ASSERT(zio->io_child_error[ZIO_CHILD_VDEV] == 0); 2297 2298 if (vd == NULL) { 2299 if (!(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 2300 spa_config_enter(spa, SCL_ZIO, zio, RW_READER); 2301 2302 /* 2303 * The mirror_ops handle multiple DVAs in a single BP. 2304 */ 2305 return (vdev_mirror_ops.vdev_op_io_start(zio)); 2306 } 2307 2308 /* 2309 * We keep track of time-sensitive I/Os so that the scan thread 2310 * can quickly react to certain workloads. In particular, we care 2311 * about non-scrubbing, top-level reads and writes with the following 2312 * characteristics: 2313 * - synchronous writes of user data to non-slog devices 2314 * - any reads of user data 2315 * When these conditions are met, adjust the timestamp of spa_last_io 2316 * which allows the scan thread to adjust its workload accordingly. 2317 */ 2318 if (!(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && zio->io_bp != NULL && 2319 vd == vd->vdev_top && !vd->vdev_islog && 2320 zio->io_bookmark.zb_objset != DMU_META_OBJSET && 2321 zio->io_txg != spa_syncing_txg(spa)) { 2322 uint64_t old = spa->spa_last_io; 2323 uint64_t new = ddi_get_lbolt64(); 2324 if (old != new) 2325 (void) atomic_cas_64(&spa->spa_last_io, old, new); 2326 } 2327 2328 align = 1ULL << vd->vdev_top->vdev_ashift; 2329 2330 if (P2PHASE(zio->io_size, align) != 0) { 2331 uint64_t asize = P2ROUNDUP(zio->io_size, align); 2332 char *abuf = zio_buf_alloc(asize); 2333 ASSERT(vd == vd->vdev_top); 2334 if (zio->io_type == ZIO_TYPE_WRITE) { 2335 bcopy(zio->io_data, abuf, zio->io_size); 2336 bzero(abuf + zio->io_size, asize - zio->io_size); 2337 } 2338 zio_push_transform(zio, abuf, asize, asize, zio_subblock); 2339 } 2340 2341 ASSERT(P2PHASE(zio->io_offset, align) == 0); 2342 ASSERT(P2PHASE(zio->io_size, align) == 0); 2343 VERIFY(zio->io_type != ZIO_TYPE_WRITE || spa_writeable(spa)); 2344 2345 /* 2346 * If this is a repair I/O, and there's no self-healing involved -- 2347 * that is, we're just resilvering what we expect to resilver -- 2348 * then don't do the I/O unless zio's txg is actually in vd's DTL. 2349 * This prevents spurious resilvering with nested replication. 2350 * For example, given a mirror of mirrors, (A+B)+(C+D), if only 2351 * A is out of date, we'll read from C+D, then use the data to 2352 * resilver A+B -- but we don't actually want to resilver B, just A. 2353 * The top-level mirror has no way to know this, so instead we just 2354 * discard unnecessary repairs as we work our way down the vdev tree. 2355 * The same logic applies to any form of nested replication: 2356 * ditto + mirror, RAID-Z + replacing, etc. This covers them all. 2357 */ 2358 if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) && 2359 !(zio->io_flags & ZIO_FLAG_SELF_HEAL) && 2360 zio->io_txg != 0 && /* not a delegated i/o */ 2361 !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) { 2362 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 2363 zio_vdev_io_bypass(zio); 2364 return (ZIO_PIPELINE_CONTINUE); 2365 } 2366 2367 if (vd->vdev_ops->vdev_op_leaf && 2368 (zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE)) { 2369 2370 if (zio->io_type == ZIO_TYPE_READ && vdev_cache_read(zio) == 0) 2371 return (ZIO_PIPELINE_CONTINUE); 2372 2373 if ((zio = vdev_queue_io(zio)) == NULL) 2374 return (ZIO_PIPELINE_STOP); 2375 2376 if (!vdev_accessible(vd, zio)) { 2377 zio->io_error = ENXIO; 2378 zio_interrupt(zio); 2379 return (ZIO_PIPELINE_STOP); 2380 } 2381 } 2382 2383 return (vd->vdev_ops->vdev_op_io_start(zio)); 2384} 2385 2386static int 2387zio_vdev_io_done(zio_t *zio) 2388{ 2389 vdev_t *vd = zio->io_vd; 2390 vdev_ops_t *ops = vd ? vd->vdev_ops : &vdev_mirror_ops; 2391 boolean_t unexpected_error = B_FALSE; 2392 2393 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 2394 return (ZIO_PIPELINE_STOP); 2395 2396 ASSERT(zio->io_type == ZIO_TYPE_READ || zio->io_type == ZIO_TYPE_WRITE); 2397 2398 if (vd != NULL && vd->vdev_ops->vdev_op_leaf) { 2399 2400 vdev_queue_io_done(zio); 2401 2402 if (zio->io_type == ZIO_TYPE_WRITE) 2403 vdev_cache_write(zio); 2404 2405 if (zio_injection_enabled && zio->io_error == 0) 2406 zio->io_error = zio_handle_device_injection(vd, 2407 zio, EIO); 2408 2409 if (zio_injection_enabled && zio->io_error == 0) 2410 zio->io_error = zio_handle_label_injection(zio, EIO); 2411 2412 if (zio->io_error) { 2413 if (!vdev_accessible(vd, zio)) { 2414 zio->io_error = ENXIO; 2415 } else { 2416 unexpected_error = B_TRUE; 2417 } 2418 } 2419 } 2420 2421 ops->vdev_op_io_done(zio); 2422 2423 if (unexpected_error) 2424 VERIFY(vdev_probe(vd, zio) == NULL); 2425 2426 return (ZIO_PIPELINE_CONTINUE); 2427} 2428 2429/* 2430 * For non-raidz ZIOs, we can just copy aside the bad data read from the 2431 * disk, and use that to finish the checksum ereport later. 2432 */ 2433static void 2434zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr, 2435 const void *good_buf) 2436{ 2437 /* no processing needed */ 2438 zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE); 2439} 2440 2441/*ARGSUSED*/ 2442void 2443zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *ignored) 2444{ 2445 void *buf = zio_buf_alloc(zio->io_size); 2446 2447 bcopy(zio->io_data, buf, zio->io_size); 2448 2449 zcr->zcr_cbinfo = zio->io_size; 2450 zcr->zcr_cbdata = buf; 2451 zcr->zcr_finish = zio_vsd_default_cksum_finish; 2452 zcr->zcr_free = zio_buf_free; 2453} 2454 2455static int 2456zio_vdev_io_assess(zio_t *zio) 2457{ 2458 vdev_t *vd = zio->io_vd; 2459 2460 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE)) 2461 return (ZIO_PIPELINE_STOP); 2462 2463 if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 2464 spa_config_exit(zio->io_spa, SCL_ZIO, zio); 2465 2466 if (zio->io_vsd != NULL) { 2467 zio->io_vsd_ops->vsd_free(zio); 2468 zio->io_vsd = NULL; 2469 } 2470 2471 if (zio_injection_enabled && zio->io_error == 0) 2472 zio->io_error = zio_handle_fault_injection(zio, EIO); 2473 2474 /* 2475 * If the I/O failed, determine whether we should attempt to retry it. 2476 * 2477 * On retry, we cut in line in the issue queue, since we don't want 2478 * compression/checksumming/etc. work to prevent our (cheap) IO reissue. 2479 */ 2480 if (zio->io_error && vd == NULL && 2481 !(zio->io_flags & (ZIO_FLAG_DONT_RETRY | ZIO_FLAG_IO_RETRY))) { 2482 ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_QUEUE)); /* not a leaf */ 2483 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_BYPASS)); /* not a leaf */ 2484 zio->io_error = 0; 2485 zio->io_flags |= ZIO_FLAG_IO_RETRY | 2486 ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE; 2487 zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1; 2488 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, 2489 zio_requeue_io_start_cut_in_line); 2490 return (ZIO_PIPELINE_STOP); 2491 } 2492 2493 /* 2494 * If we got an error on a leaf device, convert it to ENXIO 2495 * if the device is not accessible at all. 2496 */ 2497 if (zio->io_error && vd != NULL && vd->vdev_ops->vdev_op_leaf && 2498 !vdev_accessible(vd, zio)) 2499 zio->io_error = ENXIO; 2500 2501 /* 2502 * If we can't write to an interior vdev (mirror or RAID-Z), 2503 * set vdev_cant_write so that we stop trying to allocate from it. 2504 */ 2505 if (zio->io_error == ENXIO && zio->io_type == ZIO_TYPE_WRITE && 2506 vd != NULL && !vd->vdev_ops->vdev_op_leaf) 2507 vd->vdev_cant_write = B_TRUE; 2508 2509 if (zio->io_error) 2510 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2511 2512 return (ZIO_PIPELINE_CONTINUE); 2513} 2514 2515void 2516zio_vdev_io_reissue(zio_t *zio) 2517{ 2518 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 2519 ASSERT(zio->io_error == 0); 2520 2521 zio->io_stage >>= 1; 2522} 2523 2524void 2525zio_vdev_io_redone(zio_t *zio) 2526{ 2527 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE); 2528 2529 zio->io_stage >>= 1; 2530} 2531 2532void 2533zio_vdev_io_bypass(zio_t *zio) 2534{ 2535 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 2536 ASSERT(zio->io_error == 0); 2537 2538 zio->io_flags |= ZIO_FLAG_IO_BYPASS; 2539 zio->io_stage = ZIO_STAGE_VDEV_IO_ASSESS >> 1; 2540} 2541 2542/* 2543 * ========================================================================== 2544 * Generate and verify checksums 2545 * ========================================================================== 2546 */ 2547static int 2548zio_checksum_generate(zio_t *zio) 2549{ 2550 blkptr_t *bp = zio->io_bp; 2551 enum zio_checksum checksum; 2552 2553 if (bp == NULL) { 2554 /* 2555 * This is zio_write_phys(). 2556 * We're either generating a label checksum, or none at all. 2557 */ 2558 checksum = zio->io_prop.zp_checksum; 2559 2560 if (checksum == ZIO_CHECKSUM_OFF) 2561 return (ZIO_PIPELINE_CONTINUE); 2562 2563 ASSERT(checksum == ZIO_CHECKSUM_LABEL); 2564 } else { 2565 if (BP_IS_GANG(bp) && zio->io_child_type == ZIO_CHILD_GANG) { 2566 ASSERT(!IO_IS_ALLOCATING(zio)); 2567 checksum = ZIO_CHECKSUM_GANG_HEADER; 2568 } else { 2569 checksum = BP_GET_CHECKSUM(bp); 2570 } 2571 } 2572 2573 zio_checksum_compute(zio, checksum, zio->io_data, zio->io_size); 2574 2575 return (ZIO_PIPELINE_CONTINUE); 2576} 2577 2578static int 2579zio_checksum_verify(zio_t *zio) 2580{ 2581 zio_bad_cksum_t info; 2582 blkptr_t *bp = zio->io_bp; 2583 int error; 2584 2585 ASSERT(zio->io_vd != NULL); 2586 2587 if (bp == NULL) { 2588 /* 2589 * This is zio_read_phys(). 2590 * We're either verifying a label checksum, or nothing at all. 2591 */ 2592 if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF) 2593 return (ZIO_PIPELINE_CONTINUE); 2594 2595 ASSERT(zio->io_prop.zp_checksum == ZIO_CHECKSUM_LABEL); 2596 } 2597 2598 if ((error = zio_checksum_error(zio, &info)) != 0) { 2599 zio->io_error = error; 2600 if (!(zio->io_flags & ZIO_FLAG_SPECULATIVE)) { 2601 zfs_ereport_start_checksum(zio->io_spa, 2602 zio->io_vd, zio, zio->io_offset, 2603 zio->io_size, NULL, &info); 2604 } 2605 } 2606 2607 return (ZIO_PIPELINE_CONTINUE); 2608} 2609 2610/* 2611 * Called by RAID-Z to ensure we don't compute the checksum twice. 2612 */ 2613void 2614zio_checksum_verified(zio_t *zio) 2615{ 2616 zio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 2617} 2618 2619/* 2620 * ========================================================================== 2621 * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other. 2622 * An error of 0 indictes success. ENXIO indicates whole-device failure, 2623 * which may be transient (e.g. unplugged) or permament. ECKSUM and EIO 2624 * indicate errors that are specific to one I/O, and most likely permanent. 2625 * Any other error is presumed to be worse because we weren't expecting it. 2626 * ========================================================================== 2627 */ 2628int 2629zio_worst_error(int e1, int e2) 2630{ 2631 static int zio_error_rank[] = { 0, ENXIO, ECKSUM, EIO }; 2632 int r1, r2; 2633 2634 for (r1 = 0; r1 < sizeof (zio_error_rank) / sizeof (int); r1++) 2635 if (e1 == zio_error_rank[r1]) 2636 break; 2637 2638 for (r2 = 0; r2 < sizeof (zio_error_rank) / sizeof (int); r2++) 2639 if (e2 == zio_error_rank[r2]) 2640 break; 2641 2642 return (r1 > r2 ? e1 : e2); 2643} 2644 2645/* 2646 * ========================================================================== 2647 * I/O completion 2648 * ========================================================================== 2649 */ 2650static int 2651zio_ready(zio_t *zio) 2652{ 2653 blkptr_t *bp = zio->io_bp; 2654 zio_t *pio, *pio_next; 2655 2656 if (zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_READY) || 2657 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_READY)) 2658 return (ZIO_PIPELINE_STOP); 2659 2660 if (zio->io_ready) { 2661 ASSERT(IO_IS_ALLOCATING(zio)); 2662 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp)); 2663 ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0); 2664 2665 zio->io_ready(zio); 2666 } 2667 2668 if (bp != NULL && bp != &zio->io_bp_copy) 2669 zio->io_bp_copy = *bp; 2670 2671 if (zio->io_error) 2672 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2673 2674 mutex_enter(&zio->io_lock); 2675 zio->io_state[ZIO_WAIT_READY] = 1; 2676 pio = zio_walk_parents(zio); 2677 mutex_exit(&zio->io_lock); 2678 2679 /* 2680 * As we notify zio's parents, new parents could be added. 2681 * New parents go to the head of zio's io_parent_list, however, 2682 * so we will (correctly) not notify them. The remainder of zio's 2683 * io_parent_list, from 'pio_next' onward, cannot change because 2684 * all parents must wait for us to be done before they can be done. 2685 */ 2686 for (; pio != NULL; pio = pio_next) { 2687 pio_next = zio_walk_parents(zio); 2688 zio_notify_parent(pio, zio, ZIO_WAIT_READY); 2689 } 2690 2691 if (zio->io_flags & ZIO_FLAG_NODATA) { 2692 if (BP_IS_GANG(bp)) { 2693 zio->io_flags &= ~ZIO_FLAG_NODATA; 2694 } else { 2695 ASSERT((uintptr_t)zio->io_data < SPA_MAXBLOCKSIZE); 2696 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 2697 } 2698 } 2699 2700 if (zio_injection_enabled && 2701 zio->io_spa->spa_syncing_txg == zio->io_txg) 2702 zio_handle_ignored_writes(zio); 2703 2704 return (ZIO_PIPELINE_CONTINUE); 2705} 2706 2707static int 2708zio_done(zio_t *zio) 2709{ 2710 spa_t *spa = zio->io_spa; 2711 zio_t *lio = zio->io_logical; 2712 blkptr_t *bp = zio->io_bp; 2713 vdev_t *vd = zio->io_vd; 2714 uint64_t psize = zio->io_size; 2715 zio_t *pio, *pio_next; 2716 2717 /* 2718 * If our children haven't all completed, 2719 * wait for them and then repeat this pipeline stage. 2720 */ 2721 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV, ZIO_WAIT_DONE) || 2722 zio_wait_for_children(zio, ZIO_CHILD_GANG, ZIO_WAIT_DONE) || 2723 zio_wait_for_children(zio, ZIO_CHILD_DDT, ZIO_WAIT_DONE) || 2724 zio_wait_for_children(zio, ZIO_CHILD_LOGICAL, ZIO_WAIT_DONE)) 2725 return (ZIO_PIPELINE_STOP); 2726 2727 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 2728 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 2729 ASSERT(zio->io_children[c][w] == 0); 2730 2731 if (bp != NULL) { 2732 ASSERT(bp->blk_pad[0] == 0); 2733 ASSERT(bp->blk_pad[1] == 0); 2734 ASSERT(bcmp(bp, &zio->io_bp_copy, sizeof (blkptr_t)) == 0 || 2735 (bp == zio_unique_parent(zio)->io_bp)); 2736 if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(bp) && 2737 zio->io_bp_override == NULL && 2738 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) { 2739 ASSERT(!BP_SHOULD_BYTESWAP(bp)); 2740 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(bp)); 2741 ASSERT(BP_COUNT_GANG(bp) == 0 || 2742 (BP_COUNT_GANG(bp) == BP_GET_NDVAS(bp))); 2743 } 2744 } 2745 2746 /* 2747 * If there were child vdev/gang/ddt errors, they apply to us now. 2748 */ 2749 zio_inherit_child_errors(zio, ZIO_CHILD_VDEV); 2750 zio_inherit_child_errors(zio, ZIO_CHILD_GANG); 2751 zio_inherit_child_errors(zio, ZIO_CHILD_DDT); 2752 2753 /* 2754 * If the I/O on the transformed data was successful, generate any 2755 * checksum reports now while we still have the transformed data. 2756 */ 2757 if (zio->io_error == 0) { 2758 while (zio->io_cksum_report != NULL) { 2759 zio_cksum_report_t *zcr = zio->io_cksum_report; 2760 uint64_t align = zcr->zcr_align; 2761 uint64_t asize = P2ROUNDUP(psize, align); 2762 char *abuf = zio->io_data; 2763 2764 if (asize != psize) { 2765 abuf = zio_buf_alloc(asize); 2766 bcopy(zio->io_data, abuf, psize); 2767 bzero(abuf + psize, asize - psize); 2768 } 2769 2770 zio->io_cksum_report = zcr->zcr_next; 2771 zcr->zcr_next = NULL; 2772 zcr->zcr_finish(zcr, abuf); 2773 zfs_ereport_free_checksum(zcr); 2774 2775 if (asize != psize) 2776 zio_buf_free(abuf, asize); 2777 } 2778 } 2779 2780 zio_pop_transforms(zio); /* note: may set zio->io_error */ 2781 2782 vdev_stat_update(zio, psize); 2783 2784 if (zio->io_error) { 2785 /* 2786 * If this I/O is attached to a particular vdev, 2787 * generate an error message describing the I/O failure 2788 * at the block level. We ignore these errors if the 2789 * device is currently unavailable. 2790 */ 2791 if (zio->io_error != ECKSUM && vd != NULL && !vdev_is_dead(vd)) 2792 zfs_ereport_post(FM_EREPORT_ZFS_IO, spa, vd, zio, 0, 0); 2793 2794 if ((zio->io_error == EIO || !(zio->io_flags & 2795 (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) && 2796 zio == lio) { 2797 /* 2798 * For logical I/O requests, tell the SPA to log the 2799 * error and generate a logical data ereport. 2800 */ 2801 spa_log_error(spa, zio); 2802 zfs_ereport_post(FM_EREPORT_ZFS_DATA, spa, NULL, zio, 2803 0, 0); 2804 } 2805 } 2806 2807 if (zio->io_error && zio == lio) { 2808 /* 2809 * Determine whether zio should be reexecuted. This will 2810 * propagate all the way to the root via zio_notify_parent(). 2811 */ 2812 ASSERT(vd == NULL && bp != NULL); 2813 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2814 2815 if (IO_IS_ALLOCATING(zio) && 2816 !(zio->io_flags & ZIO_FLAG_CANFAIL)) { 2817 if (zio->io_error != ENOSPC) 2818 zio->io_reexecute |= ZIO_REEXECUTE_NOW; 2819 else 2820 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 2821 } 2822 2823 if ((zio->io_type == ZIO_TYPE_READ || 2824 zio->io_type == ZIO_TYPE_FREE) && 2825 !(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && 2826 zio->io_error == ENXIO && 2827 spa_load_state(spa) == SPA_LOAD_NONE && 2828 spa_get_failmode(spa) != ZIO_FAILURE_MODE_CONTINUE) 2829 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 2830 2831 if (!(zio->io_flags & ZIO_FLAG_CANFAIL) && !zio->io_reexecute) 2832 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 2833 2834 /* 2835 * Here is a possibly good place to attempt to do 2836 * either combinatorial reconstruction or error correction 2837 * based on checksums. It also might be a good place 2838 * to send out preliminary ereports before we suspend 2839 * processing. 2840 */ 2841 } 2842 2843 /* 2844 * If there were logical child errors, they apply to us now. 2845 * We defer this until now to avoid conflating logical child 2846 * errors with errors that happened to the zio itself when 2847 * updating vdev stats and reporting FMA events above. 2848 */ 2849 zio_inherit_child_errors(zio, ZIO_CHILD_LOGICAL); 2850 2851 if ((zio->io_error || zio->io_reexecute) && 2852 IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio && 2853 !(zio->io_flags & ZIO_FLAG_IO_REWRITE)) 2854 zio_dva_unallocate(zio, zio->io_gang_tree, bp); 2855 2856 zio_gang_tree_free(&zio->io_gang_tree); 2857 2858 /* 2859 * Godfather I/Os should never suspend. 2860 */ 2861 if ((zio->io_flags & ZIO_FLAG_GODFATHER) && 2862 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) 2863 zio->io_reexecute = 0; 2864 2865 if (zio->io_reexecute) { 2866 /* 2867 * This is a logical I/O that wants to reexecute. 2868 * 2869 * Reexecute is top-down. When an i/o fails, if it's not 2870 * the root, it simply notifies its parent and sticks around. 2871 * The parent, seeing that it still has children in zio_done(), 2872 * does the same. This percolates all the way up to the root. 2873 * The root i/o will reexecute or suspend the entire tree. 2874 * 2875 * This approach ensures that zio_reexecute() honors 2876 * all the original i/o dependency relationships, e.g. 2877 * parents not executing until children are ready. 2878 */ 2879 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2880 2881 zio->io_gang_leader = NULL; 2882 2883 mutex_enter(&zio->io_lock); 2884 zio->io_state[ZIO_WAIT_DONE] = 1; 2885 mutex_exit(&zio->io_lock); 2886 2887 /* 2888 * "The Godfather" I/O monitors its children but is 2889 * not a true parent to them. It will track them through 2890 * the pipeline but severs its ties whenever they get into 2891 * trouble (e.g. suspended). This allows "The Godfather" 2892 * I/O to return status without blocking. 2893 */ 2894 for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) { 2895 zio_link_t *zl = zio->io_walk_link; 2896 pio_next = zio_walk_parents(zio); 2897 2898 if ((pio->io_flags & ZIO_FLAG_GODFATHER) && 2899 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) { 2900 zio_remove_child(pio, zio, zl); 2901 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 2902 } 2903 } 2904 2905 if ((pio = zio_unique_parent(zio)) != NULL) { 2906 /* 2907 * We're not a root i/o, so there's nothing to do 2908 * but notify our parent. Don't propagate errors 2909 * upward since we haven't permanently failed yet. 2910 */ 2911 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 2912 zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE; 2913 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 2914 } else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) { 2915 /* 2916 * We'd fail again if we reexecuted now, so suspend 2917 * until conditions improve (e.g. device comes online). 2918 */ 2919 zio_suspend(spa, zio); 2920 } else { 2921 /* 2922 * Reexecution is potentially a huge amount of work. 2923 * Hand it off to the otherwise-unused claim taskq. 2924 */ 2925#ifdef _KERNEL 2926 (void) taskq_dispatch_safe( 2927 spa->spa_zio_taskq[ZIO_TYPE_CLAIM][ZIO_TASKQ_ISSUE], 2928 (task_func_t *)zio_reexecute, zio, TQ_SLEEP, 2929 &zio->io_task); 2930#else 2931 (void) taskq_dispatch( 2932 spa->spa_zio_taskq[ZIO_TYPE_CLAIM][ZIO_TASKQ_ISSUE], 2933 (task_func_t *)zio_reexecute, zio, TQ_SLEEP); 2934#endif 2935 } 2936 return (ZIO_PIPELINE_STOP); 2937 } 2938 2939 ASSERT(zio->io_child_count == 0); 2940 ASSERT(zio->io_reexecute == 0); 2941 ASSERT(zio->io_error == 0 || (zio->io_flags & ZIO_FLAG_CANFAIL)); 2942 2943 /* 2944 * Report any checksum errors, since the I/O is complete. 2945 */ 2946 while (zio->io_cksum_report != NULL) { 2947 zio_cksum_report_t *zcr = zio->io_cksum_report; 2948 zio->io_cksum_report = zcr->zcr_next; 2949 zcr->zcr_next = NULL; 2950 zcr->zcr_finish(zcr, NULL); 2951 zfs_ereport_free_checksum(zcr); 2952 } 2953 2954 /* 2955 * It is the responsibility of the done callback to ensure that this 2956 * particular zio is no longer discoverable for adoption, and as 2957 * such, cannot acquire any new parents. 2958 */ 2959 if (zio->io_done) 2960 zio->io_done(zio); 2961 2962 mutex_enter(&zio->io_lock); 2963 zio->io_state[ZIO_WAIT_DONE] = 1; 2964 mutex_exit(&zio->io_lock); 2965 2966 for (pio = zio_walk_parents(zio); pio != NULL; pio = pio_next) { 2967 zio_link_t *zl = zio->io_walk_link; 2968 pio_next = zio_walk_parents(zio); 2969 zio_remove_child(pio, zio, zl); 2970 zio_notify_parent(pio, zio, ZIO_WAIT_DONE); 2971 } 2972 2973 if (zio->io_waiter != NULL) { 2974 mutex_enter(&zio->io_lock); 2975 zio->io_executor = NULL; 2976 cv_broadcast(&zio->io_cv); 2977 mutex_exit(&zio->io_lock); 2978 } else { 2979 zio_destroy(zio); 2980 } 2981 2982 return (ZIO_PIPELINE_STOP); 2983} 2984 2985/* 2986 * ========================================================================== 2987 * I/O pipeline definition 2988 * ========================================================================== 2989 */ 2990static zio_pipe_stage_t *zio_pipeline[] = { 2991 NULL, 2992 zio_read_bp_init, 2993 zio_free_bp_init, 2994 zio_issue_async, 2995 zio_write_bp_init, 2996 zio_checksum_generate, 2997 zio_ddt_read_start, 2998 zio_ddt_read_done, 2999 zio_ddt_write, 3000 zio_ddt_free, 3001 zio_gang_assemble, 3002 zio_gang_issue, 3003 zio_dva_allocate, 3004 zio_dva_free, 3005 zio_dva_claim, 3006 zio_ready, 3007 zio_vdev_io_start, 3008 zio_vdev_io_done, 3009 zio_vdev_io_assess, 3010 zio_checksum_verify, 3011 zio_done 3012};
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