1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or https://opensource.org/licenses/CDDL-1.0. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2011, 2020 by Delphix. All rights reserved. 24 * Copyright (c) 2011 Nexenta Systems, Inc. All rights reserved. 25 * Copyright (c) 2017, Intel Corporation. 26 * Copyright (c) 2019, Klara Inc. 27 * Copyright (c) 2019, Allan Jude 28 * Copyright (c) 2021, Datto, Inc. 29 */ 30 31 #include <sys/sysmacros.h> 32 #include <sys/zfs_context.h> 33 #include <sys/fm/fs/zfs.h> 34 #include <sys/spa.h> 35 #include <sys/txg.h> 36 #include <sys/spa_impl.h> 37 #include <sys/vdev_impl.h> 38 #include <sys/vdev_trim.h> 39 #include <sys/zio_impl.h> 40 #include <sys/zio_compress.h> 41 #include <sys/zio_checksum.h> 42 #include <sys/dmu_objset.h> 43 #include <sys/arc.h> 44 #include <sys/ddt.h> 45 #include <sys/blkptr.h> 46 #include <sys/zfeature.h> 47 #include <sys/dsl_scan.h> 48 #include <sys/metaslab_impl.h> 49 #include <sys/time.h> 50 #include <sys/trace_zfs.h> 51 #include <sys/abd.h> 52 #include <sys/dsl_crypt.h> 53 #include <cityhash.h> 54 55 /* 56 * ========================================================================== 57 * I/O type descriptions 58 * ========================================================================== 59 */ 60 const char *const zio_type_name[ZIO_TYPES] = { 61 /* 62 * Note: Linux kernel thread name length is limited 63 * so these names will differ from upstream open zfs. 64 */ 65 "z_null", "z_rd", "z_wr", "z_fr", "z_cl", "z_ioctl", "z_trim" 66 }; 67 68 int zio_dva_throttle_enabled = B_TRUE; 69 static int zio_deadman_log_all = B_FALSE; 70 71 /* 72 * ========================================================================== 73 * I/O kmem caches 74 * ========================================================================== 75 */ 76 static kmem_cache_t *zio_cache; 77 static kmem_cache_t *zio_link_cache; 78 kmem_cache_t *zio_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; 79 kmem_cache_t *zio_data_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; 80 #if defined(ZFS_DEBUG) && !defined(_KERNEL) 81 static uint64_t zio_buf_cache_allocs[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; 82 static uint64_t zio_buf_cache_frees[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT]; 83 #endif 84 85 /* Mark IOs as "slow" if they take longer than 30 seconds */ 86 static uint_t zio_slow_io_ms = (30 * MILLISEC); 87 88 #define BP_SPANB(indblkshift, level) \ 89 (((uint64_t)1) << ((level) * ((indblkshift) - SPA_BLKPTRSHIFT))) 90 #define COMPARE_META_LEVEL 0x80000000ul 91 /* 92 * The following actions directly effect the spa's sync-to-convergence logic. 93 * The values below define the sync pass when we start performing the action. 94 * Care should be taken when changing these values as they directly impact 95 * spa_sync() performance. Tuning these values may introduce subtle performance 96 * pathologies and should only be done in the context of performance analysis. 97 * These tunables will eventually be removed and replaced with #defines once 98 * enough analysis has been done to determine optimal values. 99 * 100 * The 'zfs_sync_pass_deferred_free' pass must be greater than 1 to ensure that 101 * regular blocks are not deferred. 102 * 103 * Starting in sync pass 8 (zfs_sync_pass_dont_compress), we disable 104 * compression (including of metadata). In practice, we don't have this 105 * many sync passes, so this has no effect. 106 * 107 * The original intent was that disabling compression would help the sync 108 * passes to converge. However, in practice disabling compression increases 109 * the average number of sync passes, because when we turn compression off, a 110 * lot of block's size will change and thus we have to re-allocate (not 111 * overwrite) them. It also increases the number of 128KB allocations (e.g. 112 * for indirect blocks and spacemaps) because these will not be compressed. 113 * The 128K allocations are especially detrimental to performance on highly 114 * fragmented systems, which may have very few free segments of this size, 115 * and may need to load new metaslabs to satisfy 128K allocations. 116 */ 117 118 /* defer frees starting in this pass */ 119 uint_t zfs_sync_pass_deferred_free = 2; 120 121 /* don't compress starting in this pass */ 122 static uint_t zfs_sync_pass_dont_compress = 8; 123 124 /* rewrite new bps starting in this pass */ 125 static uint_t zfs_sync_pass_rewrite = 2; 126 127 /* 128 * An allocating zio is one that either currently has the DVA allocate 129 * stage set or will have it later in its lifetime. 130 */ 131 #define IO_IS_ALLOCATING(zio) ((zio)->io_orig_pipeline & ZIO_STAGE_DVA_ALLOCATE) 132 133 /* 134 * Enable smaller cores by excluding metadata 135 * allocations as well. 136 */ 137 int zio_exclude_metadata = 0; 138 static int zio_requeue_io_start_cut_in_line = 1; 139 140 #ifdef ZFS_DEBUG 141 static const int zio_buf_debug_limit = 16384; 142 #else 143 static const int zio_buf_debug_limit = 0; 144 #endif 145 146 static inline void __zio_execute(zio_t *zio); 147 148 static void zio_taskq_dispatch(zio_t *, zio_taskq_type_t, boolean_t); 149 150 void 151 zio_init(void) 152 { 153 size_t c; 154 155 zio_cache = kmem_cache_create("zio_cache", 156 sizeof (zio_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 157 zio_link_cache = kmem_cache_create("zio_link_cache", 158 sizeof (zio_link_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 159 160 /* 161 * For small buffers, we want a cache for each multiple of 162 * SPA_MINBLOCKSIZE. For larger buffers, we want a cache 163 * for each quarter-power of 2. 164 */ 165 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { 166 size_t size = (c + 1) << SPA_MINBLOCKSHIFT; 167 size_t p2 = size; 168 size_t align = 0; 169 size_t data_cflags, cflags; 170 171 data_cflags = KMC_NODEBUG; 172 cflags = (zio_exclude_metadata || size > zio_buf_debug_limit) ? 173 KMC_NODEBUG : 0; 174 175 while (!ISP2(p2)) 176 p2 &= p2 - 1; 177 178 #ifndef _KERNEL 179 /* 180 * If we are using watchpoints, put each buffer on its own page, 181 * to eliminate the performance overhead of trapping to the 182 * kernel when modifying a non-watched buffer that shares the 183 * page with a watched buffer. 184 */ 185 if (arc_watch && !IS_P2ALIGNED(size, PAGESIZE)) 186 continue; 187 /* 188 * Here's the problem - on 4K native devices in userland on 189 * Linux using O_DIRECT, buffers must be 4K aligned or I/O 190 * will fail with EINVAL, causing zdb (and others) to coredump. 191 * Since userland probably doesn't need optimized buffer caches, 192 * we just force 4K alignment on everything. 193 */ 194 align = 8 * SPA_MINBLOCKSIZE; 195 #else 196 if (size < PAGESIZE) { 197 align = SPA_MINBLOCKSIZE; 198 } else if (IS_P2ALIGNED(size, p2 >> 2)) { 199 align = PAGESIZE; 200 } 201 #endif 202 203 if (align != 0) { 204 char name[36]; 205 if (cflags == data_cflags) { 206 /* 207 * Resulting kmem caches would be identical. 208 * Save memory by creating only one. 209 */ 210 (void) snprintf(name, sizeof (name), 211 "zio_buf_comb_%lu", (ulong_t)size); 212 zio_buf_cache[c] = kmem_cache_create(name, 213 size, align, NULL, NULL, NULL, NULL, NULL, 214 cflags); 215 zio_data_buf_cache[c] = zio_buf_cache[c]; 216 continue; 217 } 218 (void) snprintf(name, sizeof (name), "zio_buf_%lu", 219 (ulong_t)size); 220 zio_buf_cache[c] = kmem_cache_create(name, size, 221 align, NULL, NULL, NULL, NULL, NULL, cflags); 222 223 (void) snprintf(name, sizeof (name), "zio_data_buf_%lu", 224 (ulong_t)size); 225 zio_data_buf_cache[c] = kmem_cache_create(name, size, 226 align, NULL, NULL, NULL, NULL, NULL, data_cflags); 227 } 228 } 229 230 while (--c != 0) { 231 ASSERT(zio_buf_cache[c] != NULL); 232 if (zio_buf_cache[c - 1] == NULL) 233 zio_buf_cache[c - 1] = zio_buf_cache[c]; 234 235 ASSERT(zio_data_buf_cache[c] != NULL); 236 if (zio_data_buf_cache[c - 1] == NULL) 237 zio_data_buf_cache[c - 1] = zio_data_buf_cache[c]; 238 } 239 240 zio_inject_init(); 241 242 lz4_init(); 243 } 244 245 void 246 zio_fini(void) 247 { 248 size_t n = SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; 249 250 #if defined(ZFS_DEBUG) && !defined(_KERNEL) 251 for (size_t i = 0; i < n; i++) { 252 if (zio_buf_cache_allocs[i] != zio_buf_cache_frees[i]) 253 (void) printf("zio_fini: [%d] %llu != %llu\n", 254 (int)((i + 1) << SPA_MINBLOCKSHIFT), 255 (long long unsigned)zio_buf_cache_allocs[i], 256 (long long unsigned)zio_buf_cache_frees[i]); 257 } 258 #endif 259 260 /* 261 * The same kmem cache can show up multiple times in both zio_buf_cache 262 * and zio_data_buf_cache. Do a wasteful but trivially correct scan to 263 * sort it out. 264 */ 265 for (size_t i = 0; i < n; i++) { 266 kmem_cache_t *cache = zio_buf_cache[i]; 267 if (cache == NULL) 268 continue; 269 for (size_t j = i; j < n; j++) { 270 if (cache == zio_buf_cache[j]) 271 zio_buf_cache[j] = NULL; 272 if (cache == zio_data_buf_cache[j]) 273 zio_data_buf_cache[j] = NULL; 274 } 275 kmem_cache_destroy(cache); 276 } 277 278 for (size_t i = 0; i < n; i++) { 279 kmem_cache_t *cache = zio_data_buf_cache[i]; 280 if (cache == NULL) 281 continue; 282 for (size_t j = i; j < n; j++) { 283 if (cache == zio_data_buf_cache[j]) 284 zio_data_buf_cache[j] = NULL; 285 } 286 kmem_cache_destroy(cache); 287 } 288 289 for (size_t i = 0; i < n; i++) { 290 VERIFY3P(zio_buf_cache[i], ==, NULL); 291 VERIFY3P(zio_data_buf_cache[i], ==, NULL); 292 } 293 294 kmem_cache_destroy(zio_link_cache); 295 kmem_cache_destroy(zio_cache); 296 297 zio_inject_fini(); 298 299 lz4_fini(); 300 } 301 302 /* 303 * ========================================================================== 304 * Allocate and free I/O buffers 305 * ========================================================================== 306 */ 307 308 /* 309 * Use zio_buf_alloc to allocate ZFS metadata. This data will appear in a 310 * crashdump if the kernel panics, so use it judiciously. Obviously, it's 311 * useful to inspect ZFS metadata, but if possible, we should avoid keeping 312 * excess / transient data in-core during a crashdump. 313 */ 314 void * 315 zio_buf_alloc(size_t size) 316 { 317 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 318 319 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 320 #if defined(ZFS_DEBUG) && !defined(_KERNEL) 321 atomic_add_64(&zio_buf_cache_allocs[c], 1); 322 #endif 323 324 return (kmem_cache_alloc(zio_buf_cache[c], KM_PUSHPAGE)); 325 } 326 327 /* 328 * Use zio_data_buf_alloc to allocate data. The data will not appear in a 329 * crashdump if the kernel panics. This exists so that we will limit the amount 330 * of ZFS data that shows up in a kernel crashdump. (Thus reducing the amount 331 * of kernel heap dumped to disk when the kernel panics) 332 */ 333 void * 334 zio_data_buf_alloc(size_t size) 335 { 336 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 337 338 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 339 340 return (kmem_cache_alloc(zio_data_buf_cache[c], KM_PUSHPAGE)); 341 } 342 343 void 344 zio_buf_free(void *buf, size_t size) 345 { 346 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 347 348 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 349 #if defined(ZFS_DEBUG) && !defined(_KERNEL) 350 atomic_add_64(&zio_buf_cache_frees[c], 1); 351 #endif 352 353 kmem_cache_free(zio_buf_cache[c], buf); 354 } 355 356 void 357 zio_data_buf_free(void *buf, size_t size) 358 { 359 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 360 361 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 362 363 kmem_cache_free(zio_data_buf_cache[c], buf); 364 } 365 366 static void 367 zio_abd_free(void *abd, size_t size) 368 { 369 (void) size; 370 abd_free((abd_t *)abd); 371 } 372 373 /* 374 * ========================================================================== 375 * Push and pop I/O transform buffers 376 * ========================================================================== 377 */ 378 void 379 zio_push_transform(zio_t *zio, abd_t *data, uint64_t size, uint64_t bufsize, 380 zio_transform_func_t *transform) 381 { 382 zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP); 383 384 zt->zt_orig_abd = zio->io_abd; 385 zt->zt_orig_size = zio->io_size; 386 zt->zt_bufsize = bufsize; 387 zt->zt_transform = transform; 388 389 zt->zt_next = zio->io_transform_stack; 390 zio->io_transform_stack = zt; 391 392 zio->io_abd = data; 393 zio->io_size = size; 394 } 395 396 void 397 zio_pop_transforms(zio_t *zio) 398 { 399 zio_transform_t *zt; 400 401 while ((zt = zio->io_transform_stack) != NULL) { 402 if (zt->zt_transform != NULL) 403 zt->zt_transform(zio, 404 zt->zt_orig_abd, zt->zt_orig_size); 405 406 if (zt->zt_bufsize != 0) 407 abd_free(zio->io_abd); 408 409 zio->io_abd = zt->zt_orig_abd; 410 zio->io_size = zt->zt_orig_size; 411 zio->io_transform_stack = zt->zt_next; 412 413 kmem_free(zt, sizeof (zio_transform_t)); 414 } 415 } 416 417 /* 418 * ========================================================================== 419 * I/O transform callbacks for subblocks, decompression, and decryption 420 * ========================================================================== 421 */ 422 static void 423 zio_subblock(zio_t *zio, abd_t *data, uint64_t size) 424 { 425 ASSERT(zio->io_size > size); 426 427 if (zio->io_type == ZIO_TYPE_READ) 428 abd_copy(data, zio->io_abd, size); 429 } 430 431 static void 432 zio_decompress(zio_t *zio, abd_t *data, uint64_t size) 433 { 434 if (zio->io_error == 0) { 435 void *tmp = abd_borrow_buf(data, size); 436 int ret = zio_decompress_data(BP_GET_COMPRESS(zio->io_bp), 437 zio->io_abd, tmp, zio->io_size, size, 438 &zio->io_prop.zp_complevel); 439 abd_return_buf_copy(data, tmp, size); 440 441 if (zio_injection_enabled && ret == 0) 442 ret = zio_handle_fault_injection(zio, EINVAL); 443 444 if (ret != 0) 445 zio->io_error = SET_ERROR(EIO); 446 } 447 } 448 449 static void 450 zio_decrypt(zio_t *zio, abd_t *data, uint64_t size) 451 { 452 int ret; 453 void *tmp; 454 blkptr_t *bp = zio->io_bp; 455 spa_t *spa = zio->io_spa; 456 uint64_t dsobj = zio->io_bookmark.zb_objset; 457 uint64_t lsize = BP_GET_LSIZE(bp); 458 dmu_object_type_t ot = BP_GET_TYPE(bp); 459 uint8_t salt[ZIO_DATA_SALT_LEN]; 460 uint8_t iv[ZIO_DATA_IV_LEN]; 461 uint8_t mac[ZIO_DATA_MAC_LEN]; 462 boolean_t no_crypt = B_FALSE; 463 464 ASSERT(BP_USES_CRYPT(bp)); 465 ASSERT3U(size, !=, 0); 466 467 if (zio->io_error != 0) 468 return; 469 470 /* 471 * Verify the cksum of MACs stored in an indirect bp. It will always 472 * be possible to verify this since it does not require an encryption 473 * key. 474 */ 475 if (BP_HAS_INDIRECT_MAC_CKSUM(bp)) { 476 zio_crypt_decode_mac_bp(bp, mac); 477 478 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF) { 479 /* 480 * We haven't decompressed the data yet, but 481 * zio_crypt_do_indirect_mac_checksum() requires 482 * decompressed data to be able to parse out the MACs 483 * from the indirect block. We decompress it now and 484 * throw away the result after we are finished. 485 */ 486 tmp = zio_buf_alloc(lsize); 487 ret = zio_decompress_data(BP_GET_COMPRESS(bp), 488 zio->io_abd, tmp, zio->io_size, lsize, 489 &zio->io_prop.zp_complevel); 490 if (ret != 0) { 491 ret = SET_ERROR(EIO); 492 goto error; 493 } 494 ret = zio_crypt_do_indirect_mac_checksum(B_FALSE, 495 tmp, lsize, BP_SHOULD_BYTESWAP(bp), mac); 496 zio_buf_free(tmp, lsize); 497 } else { 498 ret = zio_crypt_do_indirect_mac_checksum_abd(B_FALSE, 499 zio->io_abd, size, BP_SHOULD_BYTESWAP(bp), mac); 500 } 501 abd_copy(data, zio->io_abd, size); 502 503 if (zio_injection_enabled && ot != DMU_OT_DNODE && ret == 0) { 504 ret = zio_handle_decrypt_injection(spa, 505 &zio->io_bookmark, ot, ECKSUM); 506 } 507 if (ret != 0) 508 goto error; 509 510 return; 511 } 512 513 /* 514 * If this is an authenticated block, just check the MAC. It would be 515 * nice to separate this out into its own flag, but when this was done, 516 * we had run out of bits in what is now zio_flag_t. Future cleanup 517 * could make this a flag bit. 518 */ 519 if (BP_IS_AUTHENTICATED(bp)) { 520 if (ot == DMU_OT_OBJSET) { 521 ret = spa_do_crypt_objset_mac_abd(B_FALSE, spa, 522 dsobj, zio->io_abd, size, BP_SHOULD_BYTESWAP(bp)); 523 } else { 524 zio_crypt_decode_mac_bp(bp, mac); 525 ret = spa_do_crypt_mac_abd(B_FALSE, spa, dsobj, 526 zio->io_abd, size, mac); 527 if (zio_injection_enabled && ret == 0) { 528 ret = zio_handle_decrypt_injection(spa, 529 &zio->io_bookmark, ot, ECKSUM); 530 } 531 } 532 abd_copy(data, zio->io_abd, size); 533 534 if (ret != 0) 535 goto error; 536 537 return; 538 } 539 540 zio_crypt_decode_params_bp(bp, salt, iv); 541 542 if (ot == DMU_OT_INTENT_LOG) { 543 tmp = abd_borrow_buf_copy(zio->io_abd, sizeof (zil_chain_t)); 544 zio_crypt_decode_mac_zil(tmp, mac); 545 abd_return_buf(zio->io_abd, tmp, sizeof (zil_chain_t)); 546 } else { 547 zio_crypt_decode_mac_bp(bp, mac); 548 } 549 550 ret = spa_do_crypt_abd(B_FALSE, spa, &zio->io_bookmark, BP_GET_TYPE(bp), 551 BP_GET_DEDUP(bp), BP_SHOULD_BYTESWAP(bp), salt, iv, mac, size, data, 552 zio->io_abd, &no_crypt); 553 if (no_crypt) 554 abd_copy(data, zio->io_abd, size); 555 556 if (ret != 0) 557 goto error; 558 559 return; 560 561 error: 562 /* assert that the key was found unless this was speculative */ 563 ASSERT(ret != EACCES || (zio->io_flags & ZIO_FLAG_SPECULATIVE)); 564 565 /* 566 * If there was a decryption / authentication error return EIO as 567 * the io_error. If this was not a speculative zio, create an ereport. 568 */ 569 if (ret == ECKSUM) { 570 zio->io_error = SET_ERROR(EIO); 571 if ((zio->io_flags & ZIO_FLAG_SPECULATIVE) == 0) { 572 spa_log_error(spa, &zio->io_bookmark); 573 (void) zfs_ereport_post(FM_EREPORT_ZFS_AUTHENTICATION, 574 spa, NULL, &zio->io_bookmark, zio, 0); 575 } 576 } else { 577 zio->io_error = ret; 578 } 579 } 580 581 /* 582 * ========================================================================== 583 * I/O parent/child relationships and pipeline interlocks 584 * ========================================================================== 585 */ 586 zio_t * 587 zio_walk_parents(zio_t *cio, zio_link_t **zl) 588 { 589 list_t *pl = &cio->io_parent_list; 590 591 *zl = (*zl == NULL) ? list_head(pl) : list_next(pl, *zl); 592 if (*zl == NULL) 593 return (NULL); 594 595 ASSERT((*zl)->zl_child == cio); 596 return ((*zl)->zl_parent); 597 } 598 599 zio_t * 600 zio_walk_children(zio_t *pio, zio_link_t **zl) 601 { 602 list_t *cl = &pio->io_child_list; 603 604 ASSERT(MUTEX_HELD(&pio->io_lock)); 605 606 *zl = (*zl == NULL) ? list_head(cl) : list_next(cl, *zl); 607 if (*zl == NULL) 608 return (NULL); 609 610 ASSERT((*zl)->zl_parent == pio); 611 return ((*zl)->zl_child); 612 } 613 614 zio_t * 615 zio_unique_parent(zio_t *cio) 616 { 617 zio_link_t *zl = NULL; 618 zio_t *pio = zio_walk_parents(cio, &zl); 619 620 VERIFY3P(zio_walk_parents(cio, &zl), ==, NULL); 621 return (pio); 622 } 623 624 void 625 zio_add_child(zio_t *pio, zio_t *cio) 626 { 627 zio_link_t *zl = kmem_cache_alloc(zio_link_cache, KM_SLEEP); 628 629 /* 630 * Logical I/Os can have logical, gang, or vdev children. 631 * Gang I/Os can have gang or vdev children. 632 * Vdev I/Os can only have vdev children. 633 * The following ASSERT captures all of these constraints. 634 */ 635 ASSERT3S(cio->io_child_type, <=, pio->io_child_type); 636 637 zl->zl_parent = pio; 638 zl->zl_child = cio; 639 640 mutex_enter(&pio->io_lock); 641 mutex_enter(&cio->io_lock); 642 643 ASSERT(pio->io_state[ZIO_WAIT_DONE] == 0); 644 645 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 646 pio->io_children[cio->io_child_type][w] += !cio->io_state[w]; 647 648 list_insert_head(&pio->io_child_list, zl); 649 list_insert_head(&cio->io_parent_list, zl); 650 651 pio->io_child_count++; 652 cio->io_parent_count++; 653 654 mutex_exit(&cio->io_lock); 655 mutex_exit(&pio->io_lock); 656 } 657 658 static void 659 zio_remove_child(zio_t *pio, zio_t *cio, zio_link_t *zl) 660 { 661 ASSERT(zl->zl_parent == pio); 662 ASSERT(zl->zl_child == cio); 663 664 mutex_enter(&pio->io_lock); 665 mutex_enter(&cio->io_lock); 666 667 list_remove(&pio->io_child_list, zl); 668 list_remove(&cio->io_parent_list, zl); 669 670 pio->io_child_count--; 671 cio->io_parent_count--; 672 673 mutex_exit(&cio->io_lock); 674 mutex_exit(&pio->io_lock); 675 kmem_cache_free(zio_link_cache, zl); 676 } 677 678 static boolean_t 679 zio_wait_for_children(zio_t *zio, uint8_t childbits, enum zio_wait_type wait) 680 { 681 boolean_t waiting = B_FALSE; 682 683 mutex_enter(&zio->io_lock); 684 ASSERT(zio->io_stall == NULL); 685 for (int c = 0; c < ZIO_CHILD_TYPES; c++) { 686 if (!(ZIO_CHILD_BIT_IS_SET(childbits, c))) 687 continue; 688 689 uint64_t *countp = &zio->io_children[c][wait]; 690 if (*countp != 0) { 691 zio->io_stage >>= 1; 692 ASSERT3U(zio->io_stage, !=, ZIO_STAGE_OPEN); 693 zio->io_stall = countp; 694 waiting = B_TRUE; 695 break; 696 } 697 } 698 mutex_exit(&zio->io_lock); 699 return (waiting); 700 } 701 702 __attribute__((always_inline)) 703 static inline void 704 zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait, 705 zio_t **next_to_executep) 706 { 707 uint64_t *countp = &pio->io_children[zio->io_child_type][wait]; 708 int *errorp = &pio->io_child_error[zio->io_child_type]; 709 710 mutex_enter(&pio->io_lock); 711 if (zio->io_error && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE)) 712 *errorp = zio_worst_error(*errorp, zio->io_error); 713 pio->io_reexecute |= zio->io_reexecute; 714 ASSERT3U(*countp, >, 0); 715 716 (*countp)--; 717 718 if (*countp == 0 && pio->io_stall == countp) { 719 zio_taskq_type_t type = 720 pio->io_stage < ZIO_STAGE_VDEV_IO_START ? ZIO_TASKQ_ISSUE : 721 ZIO_TASKQ_INTERRUPT; 722 pio->io_stall = NULL; 723 mutex_exit(&pio->io_lock); 724 725 /* 726 * If we can tell the caller to execute this parent next, do 727 * so. Otherwise dispatch the parent zio as its own task. 728 * 729 * Having the caller execute the parent when possible reduces 730 * locking on the zio taskq's, reduces context switch 731 * overhead, and has no recursion penalty. Note that one 732 * read from disk typically causes at least 3 zio's: a 733 * zio_null(), the logical zio_read(), and then a physical 734 * zio. When the physical ZIO completes, we are able to call 735 * zio_done() on all 3 of these zio's from one invocation of 736 * zio_execute() by returning the parent back to 737 * zio_execute(). Since the parent isn't executed until this 738 * thread returns back to zio_execute(), the caller should do 739 * so promptly. 740 * 741 * In other cases, dispatching the parent prevents 742 * overflowing the stack when we have deeply nested 743 * parent-child relationships, as we do with the "mega zio" 744 * of writes for spa_sync(), and the chain of ZIL blocks. 745 */ 746 if (next_to_executep != NULL && *next_to_executep == NULL) { 747 *next_to_executep = pio; 748 } else { 749 zio_taskq_dispatch(pio, type, B_FALSE); 750 } 751 } else { 752 mutex_exit(&pio->io_lock); 753 } 754 } 755 756 static void 757 zio_inherit_child_errors(zio_t *zio, enum zio_child c) 758 { 759 if (zio->io_child_error[c] != 0 && zio->io_error == 0) 760 zio->io_error = zio->io_child_error[c]; 761 } 762 763 int 764 zio_bookmark_compare(const void *x1, const void *x2) 765 { 766 const zio_t *z1 = x1; 767 const zio_t *z2 = x2; 768 769 if (z1->io_bookmark.zb_objset < z2->io_bookmark.zb_objset) 770 return (-1); 771 if (z1->io_bookmark.zb_objset > z2->io_bookmark.zb_objset) 772 return (1); 773 774 if (z1->io_bookmark.zb_object < z2->io_bookmark.zb_object) 775 return (-1); 776 if (z1->io_bookmark.zb_object > z2->io_bookmark.zb_object) 777 return (1); 778 779 if (z1->io_bookmark.zb_level < z2->io_bookmark.zb_level) 780 return (-1); 781 if (z1->io_bookmark.zb_level > z2->io_bookmark.zb_level) 782 return (1); 783 784 if (z1->io_bookmark.zb_blkid < z2->io_bookmark.zb_blkid) 785 return (-1); 786 if (z1->io_bookmark.zb_blkid > z2->io_bookmark.zb_blkid) 787 return (1); 788 789 if (z1 < z2) 790 return (-1); 791 if (z1 > z2) 792 return (1); 793 794 return (0); 795 } 796 797 /* 798 * ========================================================================== 799 * Create the various types of I/O (read, write, free, etc) 800 * ========================================================================== 801 */ 802 static zio_t * 803 zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 804 abd_t *data, uint64_t lsize, uint64_t psize, zio_done_func_t *done, 805 void *private, zio_type_t type, zio_priority_t priority, 806 zio_flag_t flags, vdev_t *vd, uint64_t offset, 807 const zbookmark_phys_t *zb, enum zio_stage stage, 808 enum zio_stage pipeline) 809 { 810 zio_t *zio; 811 812 IMPLY(type != ZIO_TYPE_TRIM, psize <= SPA_MAXBLOCKSIZE); 813 ASSERT(P2PHASE(psize, SPA_MINBLOCKSIZE) == 0); 814 ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0); 815 816 ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER)); 817 ASSERT(!bp || !(flags & ZIO_FLAG_CONFIG_WRITER)); 818 ASSERT(vd || stage == ZIO_STAGE_OPEN); 819 820 IMPLY(lsize != psize, (flags & ZIO_FLAG_RAW_COMPRESS) != 0); 821 822 zio = kmem_cache_alloc(zio_cache, KM_SLEEP); 823 memset(zio, 0, sizeof (zio_t)); 824 825 mutex_init(&zio->io_lock, NULL, MUTEX_NOLOCKDEP, NULL); 826 cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL); 827 828 list_create(&zio->io_parent_list, sizeof (zio_link_t), 829 offsetof(zio_link_t, zl_parent_node)); 830 list_create(&zio->io_child_list, sizeof (zio_link_t), 831 offsetof(zio_link_t, zl_child_node)); 832 metaslab_trace_init(&zio->io_alloc_list); 833 834 if (vd != NULL) 835 zio->io_child_type = ZIO_CHILD_VDEV; 836 else if (flags & ZIO_FLAG_GANG_CHILD) 837 zio->io_child_type = ZIO_CHILD_GANG; 838 else if (flags & ZIO_FLAG_DDT_CHILD) 839 zio->io_child_type = ZIO_CHILD_DDT; 840 else 841 zio->io_child_type = ZIO_CHILD_LOGICAL; 842 843 if (bp != NULL) { 844 zio->io_bp = (blkptr_t *)bp; 845 zio->io_bp_copy = *bp; 846 zio->io_bp_orig = *bp; 847 if (type != ZIO_TYPE_WRITE || 848 zio->io_child_type == ZIO_CHILD_DDT) 849 zio->io_bp = &zio->io_bp_copy; /* so caller can free */ 850 if (zio->io_child_type == ZIO_CHILD_LOGICAL) 851 zio->io_logical = zio; 852 if (zio->io_child_type > ZIO_CHILD_GANG && BP_IS_GANG(bp)) 853 pipeline |= ZIO_GANG_STAGES; 854 } 855 856 zio->io_spa = spa; 857 zio->io_txg = txg; 858 zio->io_done = done; 859 zio->io_private = private; 860 zio->io_type = type; 861 zio->io_priority = priority; 862 zio->io_vd = vd; 863 zio->io_offset = offset; 864 zio->io_orig_abd = zio->io_abd = data; 865 zio->io_orig_size = zio->io_size = psize; 866 zio->io_lsize = lsize; 867 zio->io_orig_flags = zio->io_flags = flags; 868 zio->io_orig_stage = zio->io_stage = stage; 869 zio->io_orig_pipeline = zio->io_pipeline = pipeline; 870 zio->io_pipeline_trace = ZIO_STAGE_OPEN; 871 872 zio->io_state[ZIO_WAIT_READY] = (stage >= ZIO_STAGE_READY); 873 zio->io_state[ZIO_WAIT_DONE] = (stage >= ZIO_STAGE_DONE); 874 875 if (zb != NULL) 876 zio->io_bookmark = *zb; 877 878 if (pio != NULL) { 879 zio->io_metaslab_class = pio->io_metaslab_class; 880 if (zio->io_logical == NULL) 881 zio->io_logical = pio->io_logical; 882 if (zio->io_child_type == ZIO_CHILD_GANG) 883 zio->io_gang_leader = pio->io_gang_leader; 884 zio_add_child(pio, zio); 885 } 886 887 taskq_init_ent(&zio->io_tqent); 888 889 return (zio); 890 } 891 892 void 893 zio_destroy(zio_t *zio) 894 { 895 metaslab_trace_fini(&zio->io_alloc_list); 896 list_destroy(&zio->io_parent_list); 897 list_destroy(&zio->io_child_list); 898 mutex_destroy(&zio->io_lock); 899 cv_destroy(&zio->io_cv); 900 kmem_cache_free(zio_cache, zio); 901 } 902 903 zio_t * 904 zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, zio_done_func_t *done, 905 void *private, zio_flag_t flags) 906 { 907 zio_t *zio; 908 909 zio = zio_create(pio, spa, 0, NULL, NULL, 0, 0, done, private, 910 ZIO_TYPE_NULL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL, 911 ZIO_STAGE_OPEN, ZIO_INTERLOCK_PIPELINE); 912 913 return (zio); 914 } 915 916 zio_t * 917 zio_root(spa_t *spa, zio_done_func_t *done, void *private, zio_flag_t flags) 918 { 919 return (zio_null(NULL, spa, NULL, done, private, flags)); 920 } 921 922 static int 923 zfs_blkptr_verify_log(spa_t *spa, const blkptr_t *bp, 924 enum blk_verify_flag blk_verify, const char *fmt, ...) 925 { 926 va_list adx; 927 char buf[256]; 928 929 va_start(adx, fmt); 930 (void) vsnprintf(buf, sizeof (buf), fmt, adx); 931 va_end(adx); 932 933 switch (blk_verify) { 934 case BLK_VERIFY_HALT: 935 dprintf_bp(bp, "blkptr at %p dprintf_bp():", bp); 936 zfs_panic_recover("%s: %s", spa_name(spa), buf); 937 break; 938 case BLK_VERIFY_LOG: 939 zfs_dbgmsg("%s: %s", spa_name(spa), buf); 940 break; 941 case BLK_VERIFY_ONLY: 942 break; 943 } 944 945 return (1); 946 } 947 948 /* 949 * Verify the block pointer fields contain reasonable values. This means 950 * it only contains known object types, checksum/compression identifiers, 951 * block sizes within the maximum allowed limits, valid DVAs, etc. 952 * 953 * If everything checks out B_TRUE is returned. The zfs_blkptr_verify 954 * argument controls the behavior when an invalid field is detected. 955 * 956 * Modes for zfs_blkptr_verify: 957 * 1) BLK_VERIFY_ONLY (evaluate the block) 958 * 2) BLK_VERIFY_LOG (evaluate the block and log problems) 959 * 3) BLK_VERIFY_HALT (call zfs_panic_recover on error) 960 */ 961 boolean_t 962 zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp, boolean_t config_held, 963 enum blk_verify_flag blk_verify) 964 { 965 int errors = 0; 966 967 if (!DMU_OT_IS_VALID(BP_GET_TYPE(bp))) { 968 errors += zfs_blkptr_verify_log(spa, bp, blk_verify, 969 "blkptr at %p has invalid TYPE %llu", 970 bp, (longlong_t)BP_GET_TYPE(bp)); 971 } 972 if (BP_GET_CHECKSUM(bp) >= ZIO_CHECKSUM_FUNCTIONS) { 973 errors += zfs_blkptr_verify_log(spa, bp, blk_verify, 974 "blkptr at %p has invalid CHECKSUM %llu", 975 bp, (longlong_t)BP_GET_CHECKSUM(bp)); 976 } 977 if (BP_GET_COMPRESS(bp) >= ZIO_COMPRESS_FUNCTIONS) { 978 errors += zfs_blkptr_verify_log(spa, bp, blk_verify, 979 "blkptr at %p has invalid COMPRESS %llu", 980 bp, (longlong_t)BP_GET_COMPRESS(bp)); 981 } 982 if (BP_GET_LSIZE(bp) > SPA_MAXBLOCKSIZE) { 983 errors += zfs_blkptr_verify_log(spa, bp, blk_verify, 984 "blkptr at %p has invalid LSIZE %llu", 985 bp, (longlong_t)BP_GET_LSIZE(bp)); 986 } 987 if (BP_GET_PSIZE(bp) > SPA_MAXBLOCKSIZE) { 988 errors += zfs_blkptr_verify_log(spa, bp, blk_verify, 989 "blkptr at %p has invalid PSIZE %llu", 990 bp, (longlong_t)BP_GET_PSIZE(bp)); 991 } 992 993 if (BP_IS_EMBEDDED(bp)) { 994 if (BPE_GET_ETYPE(bp) >= NUM_BP_EMBEDDED_TYPES) { 995 errors += zfs_blkptr_verify_log(spa, bp, blk_verify, 996 "blkptr at %p has invalid ETYPE %llu", 997 bp, (longlong_t)BPE_GET_ETYPE(bp)); 998 } 999 } 1000 1001 /* 1002 * Do not verify individual DVAs if the config is not trusted. This 1003 * will be done once the zio is executed in vdev_mirror_map_alloc. 1004 */ 1005 if (!spa->spa_trust_config) 1006 return (errors == 0); 1007 1008 if (!config_held) 1009 spa_config_enter(spa, SCL_VDEV, bp, RW_READER); 1010 else 1011 ASSERT(spa_config_held(spa, SCL_VDEV, RW_WRITER)); 1012 /* 1013 * Pool-specific checks. 1014 * 1015 * Note: it would be nice to verify that the blk_birth and 1016 * BP_PHYSICAL_BIRTH() are not too large. However, spa_freeze() 1017 * allows the birth time of log blocks (and dmu_sync()-ed blocks 1018 * that are in the log) to be arbitrarily large. 1019 */ 1020 for (int i = 0; i < BP_GET_NDVAS(bp); i++) { 1021 const dva_t *dva = &bp->blk_dva[i]; 1022 uint64_t vdevid = DVA_GET_VDEV(dva); 1023 1024 if (vdevid >= spa->spa_root_vdev->vdev_children) { 1025 errors += zfs_blkptr_verify_log(spa, bp, blk_verify, 1026 "blkptr at %p DVA %u has invalid VDEV %llu", 1027 bp, i, (longlong_t)vdevid); 1028 continue; 1029 } 1030 vdev_t *vd = spa->spa_root_vdev->vdev_child[vdevid]; 1031 if (vd == NULL) { 1032 errors += zfs_blkptr_verify_log(spa, bp, blk_verify, 1033 "blkptr at %p DVA %u has invalid VDEV %llu", 1034 bp, i, (longlong_t)vdevid); 1035 continue; 1036 } 1037 if (vd->vdev_ops == &vdev_hole_ops) { 1038 errors += zfs_blkptr_verify_log(spa, bp, blk_verify, 1039 "blkptr at %p DVA %u has hole VDEV %llu", 1040 bp, i, (longlong_t)vdevid); 1041 continue; 1042 } 1043 if (vd->vdev_ops == &vdev_missing_ops) { 1044 /* 1045 * "missing" vdevs are valid during import, but we 1046 * don't have their detailed info (e.g. asize), so 1047 * we can't perform any more checks on them. 1048 */ 1049 continue; 1050 } 1051 uint64_t offset = DVA_GET_OFFSET(dva); 1052 uint64_t asize = DVA_GET_ASIZE(dva); 1053 if (DVA_GET_GANG(dva)) 1054 asize = vdev_gang_header_asize(vd); 1055 if (offset + asize > vd->vdev_asize) { 1056 errors += zfs_blkptr_verify_log(spa, bp, blk_verify, 1057 "blkptr at %p DVA %u has invalid OFFSET %llu", 1058 bp, i, (longlong_t)offset); 1059 } 1060 } 1061 if (errors > 0) 1062 dprintf_bp(bp, "blkptr at %p dprintf_bp():", bp); 1063 if (!config_held) 1064 spa_config_exit(spa, SCL_VDEV, bp); 1065 1066 return (errors == 0); 1067 } 1068 1069 boolean_t 1070 zfs_dva_valid(spa_t *spa, const dva_t *dva, const blkptr_t *bp) 1071 { 1072 (void) bp; 1073 uint64_t vdevid = DVA_GET_VDEV(dva); 1074 1075 if (vdevid >= spa->spa_root_vdev->vdev_children) 1076 return (B_FALSE); 1077 1078 vdev_t *vd = spa->spa_root_vdev->vdev_child[vdevid]; 1079 if (vd == NULL) 1080 return (B_FALSE); 1081 1082 if (vd->vdev_ops == &vdev_hole_ops) 1083 return (B_FALSE); 1084 1085 if (vd->vdev_ops == &vdev_missing_ops) { 1086 return (B_FALSE); 1087 } 1088 1089 uint64_t offset = DVA_GET_OFFSET(dva); 1090 uint64_t asize = DVA_GET_ASIZE(dva); 1091 1092 if (DVA_GET_GANG(dva)) 1093 asize = vdev_gang_header_asize(vd); 1094 if (offset + asize > vd->vdev_asize) 1095 return (B_FALSE); 1096 1097 return (B_TRUE); 1098 } 1099 1100 zio_t * 1101 zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, 1102 abd_t *data, uint64_t size, zio_done_func_t *done, void *private, 1103 zio_priority_t priority, zio_flag_t flags, const zbookmark_phys_t *zb) 1104 { 1105 zio_t *zio; 1106 1107 zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp, 1108 data, size, size, done, private, 1109 ZIO_TYPE_READ, priority, flags, NULL, 0, zb, 1110 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 1111 ZIO_DDT_CHILD_READ_PIPELINE : ZIO_READ_PIPELINE); 1112 1113 return (zio); 1114 } 1115 1116 zio_t * 1117 zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, 1118 abd_t *data, uint64_t lsize, uint64_t psize, const zio_prop_t *zp, 1119 zio_done_func_t *ready, zio_done_func_t *children_ready, 1120 zio_done_func_t *physdone, zio_done_func_t *done, 1121 void *private, zio_priority_t priority, zio_flag_t flags, 1122 const zbookmark_phys_t *zb) 1123 { 1124 zio_t *zio; 1125 1126 ASSERT(zp->zp_checksum >= ZIO_CHECKSUM_OFF && 1127 zp->zp_checksum < ZIO_CHECKSUM_FUNCTIONS && 1128 zp->zp_compress >= ZIO_COMPRESS_OFF && 1129 zp->zp_compress < ZIO_COMPRESS_FUNCTIONS && 1130 DMU_OT_IS_VALID(zp->zp_type) && 1131 zp->zp_level < 32 && 1132 zp->zp_copies > 0 && 1133 zp->zp_copies <= spa_max_replication(spa)); 1134 1135 zio = zio_create(pio, spa, txg, bp, data, lsize, psize, done, private, 1136 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 1137 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 1138 ZIO_DDT_CHILD_WRITE_PIPELINE : ZIO_WRITE_PIPELINE); 1139 1140 zio->io_ready = ready; 1141 zio->io_children_ready = children_ready; 1142 zio->io_physdone = physdone; 1143 zio->io_prop = *zp; 1144 1145 /* 1146 * Data can be NULL if we are going to call zio_write_override() to 1147 * provide the already-allocated BP. But we may need the data to 1148 * verify a dedup hit (if requested). In this case, don't try to 1149 * dedup (just take the already-allocated BP verbatim). Encrypted 1150 * dedup blocks need data as well so we also disable dedup in this 1151 * case. 1152 */ 1153 if (data == NULL && 1154 (zio->io_prop.zp_dedup_verify || zio->io_prop.zp_encrypt)) { 1155 zio->io_prop.zp_dedup = zio->io_prop.zp_dedup_verify = B_FALSE; 1156 } 1157 1158 return (zio); 1159 } 1160 1161 zio_t * 1162 zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, abd_t *data, 1163 uint64_t size, zio_done_func_t *done, void *private, 1164 zio_priority_t priority, zio_flag_t flags, zbookmark_phys_t *zb) 1165 { 1166 zio_t *zio; 1167 1168 zio = zio_create(pio, spa, txg, bp, data, size, size, done, private, 1169 ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_IO_REWRITE, NULL, 0, zb, 1170 ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE); 1171 1172 return (zio); 1173 } 1174 1175 void 1176 zio_write_override(zio_t *zio, blkptr_t *bp, int copies, boolean_t nopwrite) 1177 { 1178 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 1179 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1180 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 1181 ASSERT(zio->io_txg == spa_syncing_txg(zio->io_spa)); 1182 1183 /* 1184 * We must reset the io_prop to match the values that existed 1185 * when the bp was first written by dmu_sync() keeping in mind 1186 * that nopwrite and dedup are mutually exclusive. 1187 */ 1188 zio->io_prop.zp_dedup = nopwrite ? B_FALSE : zio->io_prop.zp_dedup; 1189 zio->io_prop.zp_nopwrite = nopwrite; 1190 zio->io_prop.zp_copies = copies; 1191 zio->io_bp_override = bp; 1192 } 1193 1194 void 1195 zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp) 1196 { 1197 1198 (void) zfs_blkptr_verify(spa, bp, B_FALSE, BLK_VERIFY_HALT); 1199 1200 /* 1201 * The check for EMBEDDED is a performance optimization. We 1202 * process the free here (by ignoring it) rather than 1203 * putting it on the list and then processing it in zio_free_sync(). 1204 */ 1205 if (BP_IS_EMBEDDED(bp)) 1206 return; 1207 1208 /* 1209 * Frees that are for the currently-syncing txg, are not going to be 1210 * deferred, and which will not need to do a read (i.e. not GANG or 1211 * DEDUP), can be processed immediately. Otherwise, put them on the 1212 * in-memory list for later processing. 1213 * 1214 * Note that we only defer frees after zfs_sync_pass_deferred_free 1215 * when the log space map feature is disabled. [see relevant comment 1216 * in spa_sync_iterate_to_convergence()] 1217 */ 1218 if (BP_IS_GANG(bp) || 1219 BP_GET_DEDUP(bp) || 1220 txg != spa->spa_syncing_txg || 1221 (spa_sync_pass(spa) >= zfs_sync_pass_deferred_free && 1222 !spa_feature_is_active(spa, SPA_FEATURE_LOG_SPACEMAP))) { 1223 metaslab_check_free(spa, bp); 1224 bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp); 1225 } else { 1226 VERIFY3P(zio_free_sync(NULL, spa, txg, bp, 0), ==, NULL); 1227 } 1228 } 1229 1230 /* 1231 * To improve performance, this function may return NULL if we were able 1232 * to do the free immediately. This avoids the cost of creating a zio 1233 * (and linking it to the parent, etc). 1234 */ 1235 zio_t * 1236 zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 1237 zio_flag_t flags) 1238 { 1239 ASSERT(!BP_IS_HOLE(bp)); 1240 ASSERT(spa_syncing_txg(spa) == txg); 1241 1242 if (BP_IS_EMBEDDED(bp)) 1243 return (NULL); 1244 1245 metaslab_check_free(spa, bp); 1246 arc_freed(spa, bp); 1247 dsl_scan_freed(spa, bp); 1248 1249 if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp)) { 1250 /* 1251 * GANG and DEDUP blocks can induce a read (for the gang block 1252 * header, or the DDT), so issue them asynchronously so that 1253 * this thread is not tied up. 1254 */ 1255 enum zio_stage stage = 1256 ZIO_FREE_PIPELINE | ZIO_STAGE_ISSUE_ASYNC; 1257 1258 return (zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 1259 BP_GET_PSIZE(bp), NULL, NULL, 1260 ZIO_TYPE_FREE, ZIO_PRIORITY_NOW, 1261 flags, NULL, 0, NULL, ZIO_STAGE_OPEN, stage)); 1262 } else { 1263 metaslab_free(spa, bp, txg, B_FALSE); 1264 return (NULL); 1265 } 1266 } 1267 1268 zio_t * 1269 zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 1270 zio_done_func_t *done, void *private, zio_flag_t flags) 1271 { 1272 zio_t *zio; 1273 1274 (void) zfs_blkptr_verify(spa, bp, flags & ZIO_FLAG_CONFIG_WRITER, 1275 BLK_VERIFY_HALT); 1276 1277 if (BP_IS_EMBEDDED(bp)) 1278 return (zio_null(pio, spa, NULL, NULL, NULL, 0)); 1279 1280 /* 1281 * A claim is an allocation of a specific block. Claims are needed 1282 * to support immediate writes in the intent log. The issue is that 1283 * immediate writes contain committed data, but in a txg that was 1284 * *not* committed. Upon opening the pool after an unclean shutdown, 1285 * the intent log claims all blocks that contain immediate write data 1286 * so that the SPA knows they're in use. 1287 * 1288 * All claims *must* be resolved in the first txg -- before the SPA 1289 * starts allocating blocks -- so that nothing is allocated twice. 1290 * If txg == 0 we just verify that the block is claimable. 1291 */ 1292 ASSERT3U(spa->spa_uberblock.ub_rootbp.blk_birth, <, 1293 spa_min_claim_txg(spa)); 1294 ASSERT(txg == spa_min_claim_txg(spa) || txg == 0); 1295 ASSERT(!BP_GET_DEDUP(bp) || !spa_writeable(spa)); /* zdb(8) */ 1296 1297 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 1298 BP_GET_PSIZE(bp), done, private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW, 1299 flags, NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE); 1300 ASSERT0(zio->io_queued_timestamp); 1301 1302 return (zio); 1303 } 1304 1305 zio_t * 1306 zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd, 1307 zio_done_func_t *done, void *private, zio_flag_t flags) 1308 { 1309 zio_t *zio; 1310 int c; 1311 1312 if (vd->vdev_children == 0) { 1313 zio = zio_create(pio, spa, 0, NULL, NULL, 0, 0, done, private, 1314 ZIO_TYPE_IOCTL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL, 1315 ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE); 1316 1317 zio->io_cmd = cmd; 1318 } else { 1319 zio = zio_null(pio, spa, NULL, NULL, NULL, flags); 1320 1321 for (c = 0; c < vd->vdev_children; c++) 1322 zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd, 1323 done, private, flags)); 1324 } 1325 1326 return (zio); 1327 } 1328 1329 zio_t * 1330 zio_trim(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 1331 zio_done_func_t *done, void *private, zio_priority_t priority, 1332 zio_flag_t flags, enum trim_flag trim_flags) 1333 { 1334 zio_t *zio; 1335 1336 ASSERT0(vd->vdev_children); 1337 ASSERT0(P2PHASE(offset, 1ULL << vd->vdev_ashift)); 1338 ASSERT0(P2PHASE(size, 1ULL << vd->vdev_ashift)); 1339 ASSERT3U(size, !=, 0); 1340 1341 zio = zio_create(pio, vd->vdev_spa, 0, NULL, NULL, size, size, done, 1342 private, ZIO_TYPE_TRIM, priority, flags | ZIO_FLAG_PHYSICAL, 1343 vd, offset, NULL, ZIO_STAGE_OPEN, ZIO_TRIM_PIPELINE); 1344 zio->io_trim_flags = trim_flags; 1345 1346 return (zio); 1347 } 1348 1349 zio_t * 1350 zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 1351 abd_t *data, int checksum, zio_done_func_t *done, void *private, 1352 zio_priority_t priority, zio_flag_t flags, boolean_t labels) 1353 { 1354 zio_t *zio; 1355 1356 ASSERT(vd->vdev_children == 0); 1357 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 1358 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 1359 ASSERT3U(offset + size, <=, vd->vdev_psize); 1360 1361 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, size, done, 1362 private, ZIO_TYPE_READ, priority, flags | ZIO_FLAG_PHYSICAL, vd, 1363 offset, NULL, ZIO_STAGE_OPEN, ZIO_READ_PHYS_PIPELINE); 1364 1365 zio->io_prop.zp_checksum = checksum; 1366 1367 return (zio); 1368 } 1369 1370 zio_t * 1371 zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 1372 abd_t *data, int checksum, zio_done_func_t *done, void *private, 1373 zio_priority_t priority, zio_flag_t flags, boolean_t labels) 1374 { 1375 zio_t *zio; 1376 1377 ASSERT(vd->vdev_children == 0); 1378 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 1379 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 1380 ASSERT3U(offset + size, <=, vd->vdev_psize); 1381 1382 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, size, done, 1383 private, ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_PHYSICAL, vd, 1384 offset, NULL, ZIO_STAGE_OPEN, ZIO_WRITE_PHYS_PIPELINE); 1385 1386 zio->io_prop.zp_checksum = checksum; 1387 1388 if (zio_checksum_table[checksum].ci_flags & ZCHECKSUM_FLAG_EMBEDDED) { 1389 /* 1390 * zec checksums are necessarily destructive -- they modify 1391 * the end of the write buffer to hold the verifier/checksum. 1392 * Therefore, we must make a local copy in case the data is 1393 * being written to multiple places in parallel. 1394 */ 1395 abd_t *wbuf = abd_alloc_sametype(data, size); 1396 abd_copy(wbuf, data, size); 1397 1398 zio_push_transform(zio, wbuf, size, size, NULL); 1399 } 1400 1401 return (zio); 1402 } 1403 1404 /* 1405 * Create a child I/O to do some work for us. 1406 */ 1407 zio_t * 1408 zio_vdev_child_io(zio_t *pio, blkptr_t *bp, vdev_t *vd, uint64_t offset, 1409 abd_t *data, uint64_t size, int type, zio_priority_t priority, 1410 zio_flag_t flags, zio_done_func_t *done, void *private) 1411 { 1412 enum zio_stage pipeline = ZIO_VDEV_CHILD_PIPELINE; 1413 zio_t *zio; 1414 1415 /* 1416 * vdev child I/Os do not propagate their error to the parent. 1417 * Therefore, for correct operation the caller *must* check for 1418 * and handle the error in the child i/o's done callback. 1419 * The only exceptions are i/os that we don't care about 1420 * (OPTIONAL or REPAIR). 1421 */ 1422 ASSERT((flags & ZIO_FLAG_OPTIONAL) || (flags & ZIO_FLAG_IO_REPAIR) || 1423 done != NULL); 1424 1425 if (type == ZIO_TYPE_READ && bp != NULL) { 1426 /* 1427 * If we have the bp, then the child should perform the 1428 * checksum and the parent need not. This pushes error 1429 * detection as close to the leaves as possible and 1430 * eliminates redundant checksums in the interior nodes. 1431 */ 1432 pipeline |= ZIO_STAGE_CHECKSUM_VERIFY; 1433 pio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 1434 } 1435 1436 if (vd->vdev_ops->vdev_op_leaf) { 1437 ASSERT0(vd->vdev_children); 1438 offset += VDEV_LABEL_START_SIZE; 1439 } 1440 1441 flags |= ZIO_VDEV_CHILD_FLAGS(pio); 1442 1443 /* 1444 * If we've decided to do a repair, the write is not speculative -- 1445 * even if the original read was. 1446 */ 1447 if (flags & ZIO_FLAG_IO_REPAIR) 1448 flags &= ~ZIO_FLAG_SPECULATIVE; 1449 1450 /* 1451 * If we're creating a child I/O that is not associated with a 1452 * top-level vdev, then the child zio is not an allocating I/O. 1453 * If this is a retried I/O then we ignore it since we will 1454 * have already processed the original allocating I/O. 1455 */ 1456 if (flags & ZIO_FLAG_IO_ALLOCATING && 1457 (vd != vd->vdev_top || (flags & ZIO_FLAG_IO_RETRY))) { 1458 ASSERT(pio->io_metaslab_class != NULL); 1459 ASSERT(pio->io_metaslab_class->mc_alloc_throttle_enabled); 1460 ASSERT(type == ZIO_TYPE_WRITE); 1461 ASSERT(priority == ZIO_PRIORITY_ASYNC_WRITE); 1462 ASSERT(!(flags & ZIO_FLAG_IO_REPAIR)); 1463 ASSERT(!(pio->io_flags & ZIO_FLAG_IO_REWRITE) || 1464 pio->io_child_type == ZIO_CHILD_GANG); 1465 1466 flags &= ~ZIO_FLAG_IO_ALLOCATING; 1467 } 1468 1469 1470 zio = zio_create(pio, pio->io_spa, pio->io_txg, bp, data, size, size, 1471 done, private, type, priority, flags, vd, offset, &pio->io_bookmark, 1472 ZIO_STAGE_VDEV_IO_START >> 1, pipeline); 1473 ASSERT3U(zio->io_child_type, ==, ZIO_CHILD_VDEV); 1474 1475 zio->io_physdone = pio->io_physdone; 1476 if (vd->vdev_ops->vdev_op_leaf && zio->io_logical != NULL) 1477 zio->io_logical->io_phys_children++; 1478 1479 return (zio); 1480 } 1481 1482 zio_t * 1483 zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, abd_t *data, uint64_t size, 1484 zio_type_t type, zio_priority_t priority, zio_flag_t flags, 1485 zio_done_func_t *done, void *private) 1486 { 1487 zio_t *zio; 1488 1489 ASSERT(vd->vdev_ops->vdev_op_leaf); 1490 1491 zio = zio_create(NULL, vd->vdev_spa, 0, NULL, 1492 data, size, size, done, private, type, priority, 1493 flags | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY | ZIO_FLAG_DELEGATED, 1494 vd, offset, NULL, 1495 ZIO_STAGE_VDEV_IO_START >> 1, ZIO_VDEV_CHILD_PIPELINE); 1496 1497 return (zio); 1498 } 1499 1500 void 1501 zio_flush(zio_t *zio, vdev_t *vd) 1502 { 1503 zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE, 1504 NULL, NULL, 1505 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY)); 1506 } 1507 1508 void 1509 zio_shrink(zio_t *zio, uint64_t size) 1510 { 1511 ASSERT3P(zio->io_executor, ==, NULL); 1512 ASSERT3U(zio->io_orig_size, ==, zio->io_size); 1513 ASSERT3U(size, <=, zio->io_size); 1514 1515 /* 1516 * We don't shrink for raidz because of problems with the 1517 * reconstruction when reading back less than the block size. 1518 * Note, BP_IS_RAIDZ() assumes no compression. 1519 */ 1520 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 1521 if (!BP_IS_RAIDZ(zio->io_bp)) { 1522 /* we are not doing a raw write */ 1523 ASSERT3U(zio->io_size, ==, zio->io_lsize); 1524 zio->io_orig_size = zio->io_size = zio->io_lsize = size; 1525 } 1526 } 1527 1528 /* 1529 * ========================================================================== 1530 * Prepare to read and write logical blocks 1531 * ========================================================================== 1532 */ 1533 1534 static zio_t * 1535 zio_read_bp_init(zio_t *zio) 1536 { 1537 blkptr_t *bp = zio->io_bp; 1538 uint64_t psize = 1539 BP_IS_EMBEDDED(bp) ? BPE_GET_PSIZE(bp) : BP_GET_PSIZE(bp); 1540 1541 ASSERT3P(zio->io_bp, ==, &zio->io_bp_copy); 1542 1543 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF && 1544 zio->io_child_type == ZIO_CHILD_LOGICAL && 1545 !(zio->io_flags & ZIO_FLAG_RAW_COMPRESS)) { 1546 zio_push_transform(zio, abd_alloc_sametype(zio->io_abd, psize), 1547 psize, psize, zio_decompress); 1548 } 1549 1550 if (((BP_IS_PROTECTED(bp) && !(zio->io_flags & ZIO_FLAG_RAW_ENCRYPT)) || 1551 BP_HAS_INDIRECT_MAC_CKSUM(bp)) && 1552 zio->io_child_type == ZIO_CHILD_LOGICAL) { 1553 zio_push_transform(zio, abd_alloc_sametype(zio->io_abd, psize), 1554 psize, psize, zio_decrypt); 1555 } 1556 1557 if (BP_IS_EMBEDDED(bp) && BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA) { 1558 int psize = BPE_GET_PSIZE(bp); 1559 void *data = abd_borrow_buf(zio->io_abd, psize); 1560 1561 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1562 decode_embedded_bp_compressed(bp, data); 1563 abd_return_buf_copy(zio->io_abd, data, psize); 1564 } else { 1565 ASSERT(!BP_IS_EMBEDDED(bp)); 1566 ASSERT3P(zio->io_bp, ==, &zio->io_bp_copy); 1567 } 1568 1569 if (!DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) && BP_GET_LEVEL(bp) == 0) 1570 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 1571 1572 if (BP_GET_TYPE(bp) == DMU_OT_DDT_ZAP) 1573 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 1574 1575 if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL) 1576 zio->io_pipeline = ZIO_DDT_READ_PIPELINE; 1577 1578 return (zio); 1579 } 1580 1581 static zio_t * 1582 zio_write_bp_init(zio_t *zio) 1583 { 1584 if (!IO_IS_ALLOCATING(zio)) 1585 return (zio); 1586 1587 ASSERT(zio->io_child_type != ZIO_CHILD_DDT); 1588 1589 if (zio->io_bp_override) { 1590 blkptr_t *bp = zio->io_bp; 1591 zio_prop_t *zp = &zio->io_prop; 1592 1593 ASSERT(bp->blk_birth != zio->io_txg); 1594 ASSERT(BP_GET_DEDUP(zio->io_bp_override) == 0); 1595 1596 *bp = *zio->io_bp_override; 1597 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1598 1599 if (BP_IS_EMBEDDED(bp)) 1600 return (zio); 1601 1602 /* 1603 * If we've been overridden and nopwrite is set then 1604 * set the flag accordingly to indicate that a nopwrite 1605 * has already occurred. 1606 */ 1607 if (!BP_IS_HOLE(bp) && zp->zp_nopwrite) { 1608 ASSERT(!zp->zp_dedup); 1609 ASSERT3U(BP_GET_CHECKSUM(bp), ==, zp->zp_checksum); 1610 zio->io_flags |= ZIO_FLAG_NOPWRITE; 1611 return (zio); 1612 } 1613 1614 ASSERT(!zp->zp_nopwrite); 1615 1616 if (BP_IS_HOLE(bp) || !zp->zp_dedup) 1617 return (zio); 1618 1619 ASSERT((zio_checksum_table[zp->zp_checksum].ci_flags & 1620 ZCHECKSUM_FLAG_DEDUP) || zp->zp_dedup_verify); 1621 1622 if (BP_GET_CHECKSUM(bp) == zp->zp_checksum && 1623 !zp->zp_encrypt) { 1624 BP_SET_DEDUP(bp, 1); 1625 zio->io_pipeline |= ZIO_STAGE_DDT_WRITE; 1626 return (zio); 1627 } 1628 1629 /* 1630 * We were unable to handle this as an override bp, treat 1631 * it as a regular write I/O. 1632 */ 1633 zio->io_bp_override = NULL; 1634 *bp = zio->io_bp_orig; 1635 zio->io_pipeline = zio->io_orig_pipeline; 1636 } 1637 1638 return (zio); 1639 } 1640 1641 static zio_t * 1642 zio_write_compress(zio_t *zio) 1643 { 1644 spa_t *spa = zio->io_spa; 1645 zio_prop_t *zp = &zio->io_prop; 1646 enum zio_compress compress = zp->zp_compress; 1647 blkptr_t *bp = zio->io_bp; 1648 uint64_t lsize = zio->io_lsize; 1649 uint64_t psize = zio->io_size; 1650 uint32_t pass = 1; 1651 1652 /* 1653 * If our children haven't all reached the ready stage, 1654 * wait for them and then repeat this pipeline stage. 1655 */ 1656 if (zio_wait_for_children(zio, ZIO_CHILD_LOGICAL_BIT | 1657 ZIO_CHILD_GANG_BIT, ZIO_WAIT_READY)) { 1658 return (NULL); 1659 } 1660 1661 if (!IO_IS_ALLOCATING(zio)) 1662 return (zio); 1663 1664 if (zio->io_children_ready != NULL) { 1665 /* 1666 * Now that all our children are ready, run the callback 1667 * associated with this zio in case it wants to modify the 1668 * data to be written. 1669 */ 1670 ASSERT3U(zp->zp_level, >, 0); 1671 zio->io_children_ready(zio); 1672 } 1673 1674 ASSERT(zio->io_child_type != ZIO_CHILD_DDT); 1675 ASSERT(zio->io_bp_override == NULL); 1676 1677 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg) { 1678 /* 1679 * We're rewriting an existing block, which means we're 1680 * working on behalf of spa_sync(). For spa_sync() to 1681 * converge, it must eventually be the case that we don't 1682 * have to allocate new blocks. But compression changes 1683 * the blocksize, which forces a reallocate, and makes 1684 * convergence take longer. Therefore, after the first 1685 * few passes, stop compressing to ensure convergence. 1686 */ 1687 pass = spa_sync_pass(spa); 1688 1689 ASSERT(zio->io_txg == spa_syncing_txg(spa)); 1690 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1691 ASSERT(!BP_GET_DEDUP(bp)); 1692 1693 if (pass >= zfs_sync_pass_dont_compress) 1694 compress = ZIO_COMPRESS_OFF; 1695 1696 /* Make sure someone doesn't change their mind on overwrites */ 1697 ASSERT(BP_IS_EMBEDDED(bp) || MIN(zp->zp_copies + BP_IS_GANG(bp), 1698 spa_max_replication(spa)) == BP_GET_NDVAS(bp)); 1699 } 1700 1701 /* If it's a compressed write that is not raw, compress the buffer. */ 1702 if (compress != ZIO_COMPRESS_OFF && 1703 !(zio->io_flags & ZIO_FLAG_RAW_COMPRESS)) { 1704 void *cbuf = zio_buf_alloc(lsize); 1705 psize = zio_compress_data(compress, zio->io_abd, cbuf, lsize, 1706 zp->zp_complevel); 1707 if (psize == 0 || psize >= lsize) { 1708 compress = ZIO_COMPRESS_OFF; 1709 zio_buf_free(cbuf, lsize); 1710 } else if (!zp->zp_dedup && !zp->zp_encrypt && 1711 psize <= BPE_PAYLOAD_SIZE && 1712 zp->zp_level == 0 && !DMU_OT_HAS_FILL(zp->zp_type) && 1713 spa_feature_is_enabled(spa, SPA_FEATURE_EMBEDDED_DATA)) { 1714 encode_embedded_bp_compressed(bp, 1715 cbuf, compress, lsize, psize); 1716 BPE_SET_ETYPE(bp, BP_EMBEDDED_TYPE_DATA); 1717 BP_SET_TYPE(bp, zio->io_prop.zp_type); 1718 BP_SET_LEVEL(bp, zio->io_prop.zp_level); 1719 zio_buf_free(cbuf, lsize); 1720 bp->blk_birth = zio->io_txg; 1721 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1722 ASSERT(spa_feature_is_active(spa, 1723 SPA_FEATURE_EMBEDDED_DATA)); 1724 return (zio); 1725 } else { 1726 /* 1727 * Round compressed size up to the minimum allocation 1728 * size of the smallest-ashift device, and zero the 1729 * tail. This ensures that the compressed size of the 1730 * BP (and thus compressratio property) are correct, 1731 * in that we charge for the padding used to fill out 1732 * the last sector. 1733 */ 1734 ASSERT3U(spa->spa_min_alloc, >=, SPA_MINBLOCKSHIFT); 1735 size_t rounded = (size_t)roundup(psize, 1736 spa->spa_min_alloc); 1737 if (rounded >= lsize) { 1738 compress = ZIO_COMPRESS_OFF; 1739 zio_buf_free(cbuf, lsize); 1740 psize = lsize; 1741 } else { 1742 abd_t *cdata = abd_get_from_buf(cbuf, lsize); 1743 abd_take_ownership_of_buf(cdata, B_TRUE); 1744 abd_zero_off(cdata, psize, rounded - psize); 1745 psize = rounded; 1746 zio_push_transform(zio, cdata, 1747 psize, lsize, NULL); 1748 } 1749 } 1750 1751 /* 1752 * We were unable to handle this as an override bp, treat 1753 * it as a regular write I/O. 1754 */ 1755 zio->io_bp_override = NULL; 1756 *bp = zio->io_bp_orig; 1757 zio->io_pipeline = zio->io_orig_pipeline; 1758 1759 } else if ((zio->io_flags & ZIO_FLAG_RAW_ENCRYPT) != 0 && 1760 zp->zp_type == DMU_OT_DNODE) { 1761 /* 1762 * The DMU actually relies on the zio layer's compression 1763 * to free metadnode blocks that have had all contained 1764 * dnodes freed. As a result, even when doing a raw 1765 * receive, we must check whether the block can be compressed 1766 * to a hole. 1767 */ 1768 psize = zio_compress_data(ZIO_COMPRESS_EMPTY, 1769 zio->io_abd, NULL, lsize, zp->zp_complevel); 1770 if (psize == 0 || psize >= lsize) 1771 compress = ZIO_COMPRESS_OFF; 1772 } else if (zio->io_flags & ZIO_FLAG_RAW_COMPRESS && 1773 !(zio->io_flags & ZIO_FLAG_RAW_ENCRYPT)) { 1774 /* 1775 * If we are raw receiving an encrypted dataset we should not 1776 * take this codepath because it will change the on-disk block 1777 * and decryption will fail. 1778 */ 1779 size_t rounded = MIN((size_t)roundup(psize, 1780 spa->spa_min_alloc), lsize); 1781 1782 if (rounded != psize) { 1783 abd_t *cdata = abd_alloc_linear(rounded, B_TRUE); 1784 abd_zero_off(cdata, psize, rounded - psize); 1785 abd_copy_off(cdata, zio->io_abd, 0, 0, psize); 1786 psize = rounded; 1787 zio_push_transform(zio, cdata, 1788 psize, rounded, NULL); 1789 } 1790 } else { 1791 ASSERT3U(psize, !=, 0); 1792 } 1793 1794 /* 1795 * The final pass of spa_sync() must be all rewrites, but the first 1796 * few passes offer a trade-off: allocating blocks defers convergence, 1797 * but newly allocated blocks are sequential, so they can be written 1798 * to disk faster. Therefore, we allow the first few passes of 1799 * spa_sync() to allocate new blocks, but force rewrites after that. 1800 * There should only be a handful of blocks after pass 1 in any case. 1801 */ 1802 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg && 1803 BP_GET_PSIZE(bp) == psize && 1804 pass >= zfs_sync_pass_rewrite) { 1805 VERIFY3U(psize, !=, 0); 1806 enum zio_stage gang_stages = zio->io_pipeline & ZIO_GANG_STAGES; 1807 1808 zio->io_pipeline = ZIO_REWRITE_PIPELINE | gang_stages; 1809 zio->io_flags |= ZIO_FLAG_IO_REWRITE; 1810 } else { 1811 BP_ZERO(bp); 1812 zio->io_pipeline = ZIO_WRITE_PIPELINE; 1813 } 1814 1815 if (psize == 0) { 1816 if (zio->io_bp_orig.blk_birth != 0 && 1817 spa_feature_is_active(spa, SPA_FEATURE_HOLE_BIRTH)) { 1818 BP_SET_LSIZE(bp, lsize); 1819 BP_SET_TYPE(bp, zp->zp_type); 1820 BP_SET_LEVEL(bp, zp->zp_level); 1821 BP_SET_BIRTH(bp, zio->io_txg, 0); 1822 } 1823 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1824 } else { 1825 ASSERT(zp->zp_checksum != ZIO_CHECKSUM_GANG_HEADER); 1826 BP_SET_LSIZE(bp, lsize); 1827 BP_SET_TYPE(bp, zp->zp_type); 1828 BP_SET_LEVEL(bp, zp->zp_level); 1829 BP_SET_PSIZE(bp, psize); 1830 BP_SET_COMPRESS(bp, compress); 1831 BP_SET_CHECKSUM(bp, zp->zp_checksum); 1832 BP_SET_DEDUP(bp, zp->zp_dedup); 1833 BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER); 1834 if (zp->zp_dedup) { 1835 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1836 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1837 ASSERT(!zp->zp_encrypt || 1838 DMU_OT_IS_ENCRYPTED(zp->zp_type)); 1839 zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE; 1840 } 1841 if (zp->zp_nopwrite) { 1842 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1843 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1844 zio->io_pipeline |= ZIO_STAGE_NOP_WRITE; 1845 } 1846 } 1847 return (zio); 1848 } 1849 1850 static zio_t * 1851 zio_free_bp_init(zio_t *zio) 1852 { 1853 blkptr_t *bp = zio->io_bp; 1854 1855 if (zio->io_child_type == ZIO_CHILD_LOGICAL) { 1856 if (BP_GET_DEDUP(bp)) 1857 zio->io_pipeline = ZIO_DDT_FREE_PIPELINE; 1858 } 1859 1860 ASSERT3P(zio->io_bp, ==, &zio->io_bp_copy); 1861 1862 return (zio); 1863 } 1864 1865 /* 1866 * ========================================================================== 1867 * Execute the I/O pipeline 1868 * ========================================================================== 1869 */ 1870 1871 static void 1872 zio_taskq_dispatch(zio_t *zio, zio_taskq_type_t q, boolean_t cutinline) 1873 { 1874 spa_t *spa = zio->io_spa; 1875 zio_type_t t = zio->io_type; 1876 int flags = (cutinline ? TQ_FRONT : 0); 1877 1878 /* 1879 * If we're a config writer or a probe, the normal issue and 1880 * interrupt threads may all be blocked waiting for the config lock. 1881 * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL. 1882 */ 1883 if (zio->io_flags & (ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_PROBE)) 1884 t = ZIO_TYPE_NULL; 1885 1886 /* 1887 * A similar issue exists for the L2ARC write thread until L2ARC 2.0. 1888 */ 1889 if (t == ZIO_TYPE_WRITE && zio->io_vd && zio->io_vd->vdev_aux) 1890 t = ZIO_TYPE_NULL; 1891 1892 /* 1893 * If this is a high priority I/O, then use the high priority taskq if 1894 * available. 1895 */ 1896 if ((zio->io_priority == ZIO_PRIORITY_NOW || 1897 zio->io_priority == ZIO_PRIORITY_SYNC_WRITE) && 1898 spa->spa_zio_taskq[t][q + 1].stqs_count != 0) 1899 q++; 1900 1901 ASSERT3U(q, <, ZIO_TASKQ_TYPES); 1902 1903 /* 1904 * NB: We are assuming that the zio can only be dispatched 1905 * to a single taskq at a time. It would be a grievous error 1906 * to dispatch the zio to another taskq at the same time. 1907 */ 1908 ASSERT(taskq_empty_ent(&zio->io_tqent)); 1909 spa_taskq_dispatch_ent(spa, t, q, zio_execute, zio, flags, 1910 &zio->io_tqent); 1911 } 1912 1913 static boolean_t 1914 zio_taskq_member(zio_t *zio, zio_taskq_type_t q) 1915 { 1916 spa_t *spa = zio->io_spa; 1917 1918 taskq_t *tq = taskq_of_curthread(); 1919 1920 for (zio_type_t t = 0; t < ZIO_TYPES; t++) { 1921 spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q]; 1922 uint_t i; 1923 for (i = 0; i < tqs->stqs_count; i++) { 1924 if (tqs->stqs_taskq[i] == tq) 1925 return (B_TRUE); 1926 } 1927 } 1928 1929 return (B_FALSE); 1930 } 1931 1932 static zio_t * 1933 zio_issue_async(zio_t *zio) 1934 { 1935 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 1936 1937 return (NULL); 1938 } 1939 1940 void 1941 zio_interrupt(void *zio) 1942 { 1943 zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE); 1944 } 1945 1946 void 1947 zio_delay_interrupt(zio_t *zio) 1948 { 1949 /* 1950 * The timeout_generic() function isn't defined in userspace, so 1951 * rather than trying to implement the function, the zio delay 1952 * functionality has been disabled for userspace builds. 1953 */ 1954 1955 #ifdef _KERNEL 1956 /* 1957 * If io_target_timestamp is zero, then no delay has been registered 1958 * for this IO, thus jump to the end of this function and "skip" the 1959 * delay; issuing it directly to the zio layer. 1960 */ 1961 if (zio->io_target_timestamp != 0) { 1962 hrtime_t now = gethrtime(); 1963 1964 if (now >= zio->io_target_timestamp) { 1965 /* 1966 * This IO has already taken longer than the target 1967 * delay to complete, so we don't want to delay it 1968 * any longer; we "miss" the delay and issue it 1969 * directly to the zio layer. This is likely due to 1970 * the target latency being set to a value less than 1971 * the underlying hardware can satisfy (e.g. delay 1972 * set to 1ms, but the disks take 10ms to complete an 1973 * IO request). 1974 */ 1975 1976 DTRACE_PROBE2(zio__delay__miss, zio_t *, zio, 1977 hrtime_t, now); 1978 1979 zio_interrupt(zio); 1980 } else { 1981 taskqid_t tid; 1982 hrtime_t diff = zio->io_target_timestamp - now; 1983 clock_t expire_at_tick = ddi_get_lbolt() + 1984 NSEC_TO_TICK(diff); 1985 1986 DTRACE_PROBE3(zio__delay__hit, zio_t *, zio, 1987 hrtime_t, now, hrtime_t, diff); 1988 1989 if (NSEC_TO_TICK(diff) == 0) { 1990 /* Our delay is less than a jiffy - just spin */ 1991 zfs_sleep_until(zio->io_target_timestamp); 1992 zio_interrupt(zio); 1993 } else { 1994 /* 1995 * Use taskq_dispatch_delay() in the place of 1996 * OpenZFS's timeout_generic(). 1997 */ 1998 tid = taskq_dispatch_delay(system_taskq, 1999 zio_interrupt, zio, TQ_NOSLEEP, 2000 expire_at_tick); 2001 if (tid == TASKQID_INVALID) { 2002 /* 2003 * Couldn't allocate a task. Just 2004 * finish the zio without a delay. 2005 */ 2006 zio_interrupt(zio); 2007 } 2008 } 2009 } 2010 return; 2011 } 2012 #endif 2013 DTRACE_PROBE1(zio__delay__skip, zio_t *, zio); 2014 zio_interrupt(zio); 2015 } 2016 2017 static void 2018 zio_deadman_impl(zio_t *pio, int ziodepth) 2019 { 2020 zio_t *cio, *cio_next; 2021 zio_link_t *zl = NULL; 2022 vdev_t *vd = pio->io_vd; 2023 2024 if (zio_deadman_log_all || (vd != NULL && vd->vdev_ops->vdev_op_leaf)) { 2025 vdev_queue_t *vq = vd ? &vd->vdev_queue : NULL; 2026 zbookmark_phys_t *zb = &pio->io_bookmark; 2027 uint64_t delta = gethrtime() - pio->io_timestamp; 2028 uint64_t failmode = spa_get_deadman_failmode(pio->io_spa); 2029 2030 zfs_dbgmsg("slow zio[%d]: zio=%px timestamp=%llu " 2031 "delta=%llu queued=%llu io=%llu " 2032 "path=%s " 2033 "last=%llu type=%d " 2034 "priority=%d flags=0x%llx stage=0x%x " 2035 "pipeline=0x%x pipeline-trace=0x%x " 2036 "objset=%llu object=%llu " 2037 "level=%llu blkid=%llu " 2038 "offset=%llu size=%llu " 2039 "error=%d", 2040 ziodepth, pio, pio->io_timestamp, 2041 (u_longlong_t)delta, pio->io_delta, pio->io_delay, 2042 vd ? vd->vdev_path : "NULL", 2043 vq ? vq->vq_io_complete_ts : 0, pio->io_type, 2044 pio->io_priority, (u_longlong_t)pio->io_flags, 2045 pio->io_stage, pio->io_pipeline, pio->io_pipeline_trace, 2046 (u_longlong_t)zb->zb_objset, (u_longlong_t)zb->zb_object, 2047 (u_longlong_t)zb->zb_level, (u_longlong_t)zb->zb_blkid, 2048 (u_longlong_t)pio->io_offset, (u_longlong_t)pio->io_size, 2049 pio->io_error); 2050 (void) zfs_ereport_post(FM_EREPORT_ZFS_DEADMAN, 2051 pio->io_spa, vd, zb, pio, 0); 2052 2053 if (failmode == ZIO_FAILURE_MODE_CONTINUE && 2054 taskq_empty_ent(&pio->io_tqent)) { 2055 zio_interrupt(pio); 2056 } 2057 } 2058 2059 mutex_enter(&pio->io_lock); 2060 for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) { 2061 cio_next = zio_walk_children(pio, &zl); 2062 zio_deadman_impl(cio, ziodepth + 1); 2063 } 2064 mutex_exit(&pio->io_lock); 2065 } 2066 2067 /* 2068 * Log the critical information describing this zio and all of its children 2069 * using the zfs_dbgmsg() interface then post deadman event for the ZED. 2070 */ 2071 void 2072 zio_deadman(zio_t *pio, const char *tag) 2073 { 2074 spa_t *spa = pio->io_spa; 2075 char *name = spa_name(spa); 2076 2077 if (!zfs_deadman_enabled || spa_suspended(spa)) 2078 return; 2079 2080 zio_deadman_impl(pio, 0); 2081 2082 switch (spa_get_deadman_failmode(spa)) { 2083 case ZIO_FAILURE_MODE_WAIT: 2084 zfs_dbgmsg("%s waiting for hung I/O to pool '%s'", tag, name); 2085 break; 2086 2087 case ZIO_FAILURE_MODE_CONTINUE: 2088 zfs_dbgmsg("%s restarting hung I/O for pool '%s'", tag, name); 2089 break; 2090 2091 case ZIO_FAILURE_MODE_PANIC: 2092 fm_panic("%s determined I/O to pool '%s' is hung.", tag, name); 2093 break; 2094 } 2095 } 2096 2097 /* 2098 * Execute the I/O pipeline until one of the following occurs: 2099 * (1) the I/O completes; (2) the pipeline stalls waiting for 2100 * dependent child I/Os; (3) the I/O issues, so we're waiting 2101 * for an I/O completion interrupt; (4) the I/O is delegated by 2102 * vdev-level caching or aggregation; (5) the I/O is deferred 2103 * due to vdev-level queueing; (6) the I/O is handed off to 2104 * another thread. In all cases, the pipeline stops whenever 2105 * there's no CPU work; it never burns a thread in cv_wait_io(). 2106 * 2107 * There's no locking on io_stage because there's no legitimate way 2108 * for multiple threads to be attempting to process the same I/O. 2109 */ 2110 static zio_pipe_stage_t *zio_pipeline[]; 2111 2112 /* 2113 * zio_execute() is a wrapper around the static function 2114 * __zio_execute() so that we can force __zio_execute() to be 2115 * inlined. This reduces stack overhead which is important 2116 * because __zio_execute() is called recursively in several zio 2117 * code paths. zio_execute() itself cannot be inlined because 2118 * it is externally visible. 2119 */ 2120 void 2121 zio_execute(void *zio) 2122 { 2123 fstrans_cookie_t cookie; 2124 2125 cookie = spl_fstrans_mark(); 2126 __zio_execute(zio); 2127 spl_fstrans_unmark(cookie); 2128 } 2129 2130 /* 2131 * Used to determine if in the current context the stack is sized large 2132 * enough to allow zio_execute() to be called recursively. A minimum 2133 * stack size of 16K is required to avoid needing to re-dispatch the zio. 2134 */ 2135 static boolean_t 2136 zio_execute_stack_check(zio_t *zio) 2137 { 2138 #if !defined(HAVE_LARGE_STACKS) 2139 dsl_pool_t *dp = spa_get_dsl(zio->io_spa); 2140 2141 /* Executing in txg_sync_thread() context. */ 2142 if (dp && curthread == dp->dp_tx.tx_sync_thread) 2143 return (B_TRUE); 2144 2145 /* Pool initialization outside of zio_taskq context. */ 2146 if (dp && spa_is_initializing(dp->dp_spa) && 2147 !zio_taskq_member(zio, ZIO_TASKQ_ISSUE) && 2148 !zio_taskq_member(zio, ZIO_TASKQ_ISSUE_HIGH)) 2149 return (B_TRUE); 2150 #else 2151 (void) zio; 2152 #endif /* HAVE_LARGE_STACKS */ 2153 2154 return (B_FALSE); 2155 } 2156 2157 __attribute__((always_inline)) 2158 static inline void 2159 __zio_execute(zio_t *zio) 2160 { 2161 ASSERT3U(zio->io_queued_timestamp, >, 0); 2162 2163 while (zio->io_stage < ZIO_STAGE_DONE) { 2164 enum zio_stage pipeline = zio->io_pipeline; 2165 enum zio_stage stage = zio->io_stage; 2166 2167 zio->io_executor = curthread; 2168 2169 ASSERT(!MUTEX_HELD(&zio->io_lock)); 2170 ASSERT(ISP2(stage)); 2171 ASSERT(zio->io_stall == NULL); 2172 2173 do { 2174 stage <<= 1; 2175 } while ((stage & pipeline) == 0); 2176 2177 ASSERT(stage <= ZIO_STAGE_DONE); 2178 2179 /* 2180 * If we are in interrupt context and this pipeline stage 2181 * will grab a config lock that is held across I/O, 2182 * or may wait for an I/O that needs an interrupt thread 2183 * to complete, issue async to avoid deadlock. 2184 * 2185 * For VDEV_IO_START, we cut in line so that the io will 2186 * be sent to disk promptly. 2187 */ 2188 if ((stage & ZIO_BLOCKING_STAGES) && zio->io_vd == NULL && 2189 zio_taskq_member(zio, ZIO_TASKQ_INTERRUPT)) { 2190 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ? 2191 zio_requeue_io_start_cut_in_line : B_FALSE; 2192 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut); 2193 return; 2194 } 2195 2196 /* 2197 * If the current context doesn't have large enough stacks 2198 * the zio must be issued asynchronously to prevent overflow. 2199 */ 2200 if (zio_execute_stack_check(zio)) { 2201 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ? 2202 zio_requeue_io_start_cut_in_line : B_FALSE; 2203 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut); 2204 return; 2205 } 2206 2207 zio->io_stage = stage; 2208 zio->io_pipeline_trace |= zio->io_stage; 2209 2210 /* 2211 * The zio pipeline stage returns the next zio to execute 2212 * (typically the same as this one), or NULL if we should 2213 * stop. 2214 */ 2215 zio = zio_pipeline[highbit64(stage) - 1](zio); 2216 2217 if (zio == NULL) 2218 return; 2219 } 2220 } 2221 2222 2223 /* 2224 * ========================================================================== 2225 * Initiate I/O, either sync or async 2226 * ========================================================================== 2227 */ 2228 int 2229 zio_wait(zio_t *zio) 2230 { 2231 /* 2232 * Some routines, like zio_free_sync(), may return a NULL zio 2233 * to avoid the performance overhead of creating and then destroying 2234 * an unneeded zio. For the callers' simplicity, we accept a NULL 2235 * zio and ignore it. 2236 */ 2237 if (zio == NULL) 2238 return (0); 2239 2240 long timeout = MSEC_TO_TICK(zfs_deadman_ziotime_ms); 2241 int error; 2242 2243 ASSERT3S(zio->io_stage, ==, ZIO_STAGE_OPEN); 2244 ASSERT3P(zio->io_executor, ==, NULL); 2245 2246 zio->io_waiter = curthread; 2247 ASSERT0(zio->io_queued_timestamp); 2248 zio->io_queued_timestamp = gethrtime(); 2249 2250 __zio_execute(zio); 2251 2252 mutex_enter(&zio->io_lock); 2253 while (zio->io_executor != NULL) { 2254 error = cv_timedwait_io(&zio->io_cv, &zio->io_lock, 2255 ddi_get_lbolt() + timeout); 2256 2257 if (zfs_deadman_enabled && error == -1 && 2258 gethrtime() - zio->io_queued_timestamp > 2259 spa_deadman_ziotime(zio->io_spa)) { 2260 mutex_exit(&zio->io_lock); 2261 timeout = MSEC_TO_TICK(zfs_deadman_checktime_ms); 2262 zio_deadman(zio, FTAG); 2263 mutex_enter(&zio->io_lock); 2264 } 2265 } 2266 mutex_exit(&zio->io_lock); 2267 2268 error = zio->io_error; 2269 zio_destroy(zio); 2270 2271 return (error); 2272 } 2273 2274 void 2275 zio_nowait(zio_t *zio) 2276 { 2277 /* 2278 * See comment in zio_wait(). 2279 */ 2280 if (zio == NULL) 2281 return; 2282 2283 ASSERT3P(zio->io_executor, ==, NULL); 2284 2285 if (zio->io_child_type == ZIO_CHILD_LOGICAL && 2286 zio_unique_parent(zio) == NULL) { 2287 zio_t *pio; 2288 2289 /* 2290 * This is a logical async I/O with no parent to wait for it. 2291 * We add it to the spa_async_root_zio "Godfather" I/O which 2292 * will ensure they complete prior to unloading the pool. 2293 */ 2294 spa_t *spa = zio->io_spa; 2295 pio = spa->spa_async_zio_root[CPU_SEQID_UNSTABLE]; 2296 2297 zio_add_child(pio, zio); 2298 } 2299 2300 ASSERT0(zio->io_queued_timestamp); 2301 zio->io_queued_timestamp = gethrtime(); 2302 __zio_execute(zio); 2303 } 2304 2305 /* 2306 * ========================================================================== 2307 * Reexecute, cancel, or suspend/resume failed I/O 2308 * ========================================================================== 2309 */ 2310 2311 static void 2312 zio_reexecute(void *arg) 2313 { 2314 zio_t *pio = arg; 2315 zio_t *cio, *cio_next; 2316 2317 ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL); 2318 ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN); 2319 ASSERT(pio->io_gang_leader == NULL); 2320 ASSERT(pio->io_gang_tree == NULL); 2321 2322 pio->io_flags = pio->io_orig_flags; 2323 pio->io_stage = pio->io_orig_stage; 2324 pio->io_pipeline = pio->io_orig_pipeline; 2325 pio->io_reexecute = 0; 2326 pio->io_flags |= ZIO_FLAG_REEXECUTED; 2327 pio->io_pipeline_trace = 0; 2328 pio->io_error = 0; 2329 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 2330 pio->io_state[w] = 0; 2331 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 2332 pio->io_child_error[c] = 0; 2333 2334 if (IO_IS_ALLOCATING(pio)) 2335 BP_ZERO(pio->io_bp); 2336 2337 /* 2338 * As we reexecute pio's children, new children could be created. 2339 * New children go to the head of pio's io_child_list, however, 2340 * so we will (correctly) not reexecute them. The key is that 2341 * the remainder of pio's io_child_list, from 'cio_next' onward, 2342 * cannot be affected by any side effects of reexecuting 'cio'. 2343 */ 2344 zio_link_t *zl = NULL; 2345 mutex_enter(&pio->io_lock); 2346 for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) { 2347 cio_next = zio_walk_children(pio, &zl); 2348 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 2349 pio->io_children[cio->io_child_type][w]++; 2350 mutex_exit(&pio->io_lock); 2351 zio_reexecute(cio); 2352 mutex_enter(&pio->io_lock); 2353 } 2354 mutex_exit(&pio->io_lock); 2355 2356 /* 2357 * Now that all children have been reexecuted, execute the parent. 2358 * We don't reexecute "The Godfather" I/O here as it's the 2359 * responsibility of the caller to wait on it. 2360 */ 2361 if (!(pio->io_flags & ZIO_FLAG_GODFATHER)) { 2362 pio->io_queued_timestamp = gethrtime(); 2363 __zio_execute(pio); 2364 } 2365 } 2366 2367 void 2368 zio_suspend(spa_t *spa, zio_t *zio, zio_suspend_reason_t reason) 2369 { 2370 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC) 2371 fm_panic("Pool '%s' has encountered an uncorrectable I/O " 2372 "failure and the failure mode property for this pool " 2373 "is set to panic.", spa_name(spa)); 2374 2375 cmn_err(CE_WARN, "Pool '%s' has encountered an uncorrectable I/O " 2376 "failure and has been suspended.\n", spa_name(spa)); 2377 2378 (void) zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL, 2379 NULL, NULL, 0); 2380 2381 mutex_enter(&spa->spa_suspend_lock); 2382 2383 if (spa->spa_suspend_zio_root == NULL) 2384 spa->spa_suspend_zio_root = zio_root(spa, NULL, NULL, 2385 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | 2386 ZIO_FLAG_GODFATHER); 2387 2388 spa->spa_suspended = reason; 2389 2390 if (zio != NULL) { 2391 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 2392 ASSERT(zio != spa->spa_suspend_zio_root); 2393 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2394 ASSERT(zio_unique_parent(zio) == NULL); 2395 ASSERT(zio->io_stage == ZIO_STAGE_DONE); 2396 zio_add_child(spa->spa_suspend_zio_root, zio); 2397 } 2398 2399 mutex_exit(&spa->spa_suspend_lock); 2400 } 2401 2402 int 2403 zio_resume(spa_t *spa) 2404 { 2405 zio_t *pio; 2406 2407 /* 2408 * Reexecute all previously suspended i/o. 2409 */ 2410 mutex_enter(&spa->spa_suspend_lock); 2411 spa->spa_suspended = ZIO_SUSPEND_NONE; 2412 cv_broadcast(&spa->spa_suspend_cv); 2413 pio = spa->spa_suspend_zio_root; 2414 spa->spa_suspend_zio_root = NULL; 2415 mutex_exit(&spa->spa_suspend_lock); 2416 2417 if (pio == NULL) 2418 return (0); 2419 2420 zio_reexecute(pio); 2421 return (zio_wait(pio)); 2422 } 2423 2424 void 2425 zio_resume_wait(spa_t *spa) 2426 { 2427 mutex_enter(&spa->spa_suspend_lock); 2428 while (spa_suspended(spa)) 2429 cv_wait(&spa->spa_suspend_cv, &spa->spa_suspend_lock); 2430 mutex_exit(&spa->spa_suspend_lock); 2431 } 2432 2433 /* 2434 * ========================================================================== 2435 * Gang blocks. 2436 * 2437 * A gang block is a collection of small blocks that looks to the DMU 2438 * like one large block. When zio_dva_allocate() cannot find a block 2439 * of the requested size, due to either severe fragmentation or the pool 2440 * being nearly full, it calls zio_write_gang_block() to construct the 2441 * block from smaller fragments. 2442 * 2443 * A gang block consists of a gang header (zio_gbh_phys_t) and up to 2444 * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like 2445 * an indirect block: it's an array of block pointers. It consumes 2446 * only one sector and hence is allocatable regardless of fragmentation. 2447 * The gang header's bps point to its gang members, which hold the data. 2448 * 2449 * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg> 2450 * as the verifier to ensure uniqueness of the SHA256 checksum. 2451 * Critically, the gang block bp's blk_cksum is the checksum of the data, 2452 * not the gang header. This ensures that data block signatures (needed for 2453 * deduplication) are independent of how the block is physically stored. 2454 * 2455 * Gang blocks can be nested: a gang member may itself be a gang block. 2456 * Thus every gang block is a tree in which root and all interior nodes are 2457 * gang headers, and the leaves are normal blocks that contain user data. 2458 * The root of the gang tree is called the gang leader. 2459 * 2460 * To perform any operation (read, rewrite, free, claim) on a gang block, 2461 * zio_gang_assemble() first assembles the gang tree (minus data leaves) 2462 * in the io_gang_tree field of the original logical i/o by recursively 2463 * reading the gang leader and all gang headers below it. This yields 2464 * an in-core tree containing the contents of every gang header and the 2465 * bps for every constituent of the gang block. 2466 * 2467 * With the gang tree now assembled, zio_gang_issue() just walks the gang tree 2468 * and invokes a callback on each bp. To free a gang block, zio_gang_issue() 2469 * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp. 2470 * zio_claim_gang() provides a similarly trivial wrapper for zio_claim(). 2471 * zio_read_gang() is a wrapper around zio_read() that omits reading gang 2472 * headers, since we already have those in io_gang_tree. zio_rewrite_gang() 2473 * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite() 2474 * of the gang header plus zio_checksum_compute() of the data to update the 2475 * gang header's blk_cksum as described above. 2476 * 2477 * The two-phase assemble/issue model solves the problem of partial failure -- 2478 * what if you'd freed part of a gang block but then couldn't read the 2479 * gang header for another part? Assembling the entire gang tree first 2480 * ensures that all the necessary gang header I/O has succeeded before 2481 * starting the actual work of free, claim, or write. Once the gang tree 2482 * is assembled, free and claim are in-memory operations that cannot fail. 2483 * 2484 * In the event that a gang write fails, zio_dva_unallocate() walks the 2485 * gang tree to immediately free (i.e. insert back into the space map) 2486 * everything we've allocated. This ensures that we don't get ENOSPC 2487 * errors during repeated suspend/resume cycles due to a flaky device. 2488 * 2489 * Gang rewrites only happen during sync-to-convergence. If we can't assemble 2490 * the gang tree, we won't modify the block, so we can safely defer the free 2491 * (knowing that the block is still intact). If we *can* assemble the gang 2492 * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free 2493 * each constituent bp and we can allocate a new block on the next sync pass. 2494 * 2495 * In all cases, the gang tree allows complete recovery from partial failure. 2496 * ========================================================================== 2497 */ 2498 2499 static void 2500 zio_gang_issue_func_done(zio_t *zio) 2501 { 2502 abd_free(zio->io_abd); 2503 } 2504 2505 static zio_t * 2506 zio_read_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data, 2507 uint64_t offset) 2508 { 2509 if (gn != NULL) 2510 return (pio); 2511 2512 return (zio_read(pio, pio->io_spa, bp, abd_get_offset(data, offset), 2513 BP_GET_PSIZE(bp), zio_gang_issue_func_done, 2514 NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 2515 &pio->io_bookmark)); 2516 } 2517 2518 static zio_t * 2519 zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data, 2520 uint64_t offset) 2521 { 2522 zio_t *zio; 2523 2524 if (gn != NULL) { 2525 abd_t *gbh_abd = 2526 abd_get_from_buf(gn->gn_gbh, SPA_GANGBLOCKSIZE); 2527 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 2528 gbh_abd, SPA_GANGBLOCKSIZE, zio_gang_issue_func_done, NULL, 2529 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 2530 &pio->io_bookmark); 2531 /* 2532 * As we rewrite each gang header, the pipeline will compute 2533 * a new gang block header checksum for it; but no one will 2534 * compute a new data checksum, so we do that here. The one 2535 * exception is the gang leader: the pipeline already computed 2536 * its data checksum because that stage precedes gang assembly. 2537 * (Presently, nothing actually uses interior data checksums; 2538 * this is just good hygiene.) 2539 */ 2540 if (gn != pio->io_gang_leader->io_gang_tree) { 2541 abd_t *buf = abd_get_offset(data, offset); 2542 2543 zio_checksum_compute(zio, BP_GET_CHECKSUM(bp), 2544 buf, BP_GET_PSIZE(bp)); 2545 2546 abd_free(buf); 2547 } 2548 /* 2549 * If we are here to damage data for testing purposes, 2550 * leave the GBH alone so that we can detect the damage. 2551 */ 2552 if (pio->io_gang_leader->io_flags & ZIO_FLAG_INDUCE_DAMAGE) 2553 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 2554 } else { 2555 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 2556 abd_get_offset(data, offset), BP_GET_PSIZE(bp), 2557 zio_gang_issue_func_done, NULL, pio->io_priority, 2558 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 2559 } 2560 2561 return (zio); 2562 } 2563 2564 static zio_t * 2565 zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data, 2566 uint64_t offset) 2567 { 2568 (void) gn, (void) data, (void) offset; 2569 2570 zio_t *zio = zio_free_sync(pio, pio->io_spa, pio->io_txg, bp, 2571 ZIO_GANG_CHILD_FLAGS(pio)); 2572 if (zio == NULL) { 2573 zio = zio_null(pio, pio->io_spa, 2574 NULL, NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio)); 2575 } 2576 return (zio); 2577 } 2578 2579 static zio_t * 2580 zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data, 2581 uint64_t offset) 2582 { 2583 (void) gn, (void) data, (void) offset; 2584 return (zio_claim(pio, pio->io_spa, pio->io_txg, bp, 2585 NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio))); 2586 } 2587 2588 static zio_gang_issue_func_t *zio_gang_issue_func[ZIO_TYPES] = { 2589 NULL, 2590 zio_read_gang, 2591 zio_rewrite_gang, 2592 zio_free_gang, 2593 zio_claim_gang, 2594 NULL 2595 }; 2596 2597 static void zio_gang_tree_assemble_done(zio_t *zio); 2598 2599 static zio_gang_node_t * 2600 zio_gang_node_alloc(zio_gang_node_t **gnpp) 2601 { 2602 zio_gang_node_t *gn; 2603 2604 ASSERT(*gnpp == NULL); 2605 2606 gn = kmem_zalloc(sizeof (*gn), KM_SLEEP); 2607 gn->gn_gbh = zio_buf_alloc(SPA_GANGBLOCKSIZE); 2608 *gnpp = gn; 2609 2610 return (gn); 2611 } 2612 2613 static void 2614 zio_gang_node_free(zio_gang_node_t **gnpp) 2615 { 2616 zio_gang_node_t *gn = *gnpp; 2617 2618 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 2619 ASSERT(gn->gn_child[g] == NULL); 2620 2621 zio_buf_free(gn->gn_gbh, SPA_GANGBLOCKSIZE); 2622 kmem_free(gn, sizeof (*gn)); 2623 *gnpp = NULL; 2624 } 2625 2626 static void 2627 zio_gang_tree_free(zio_gang_node_t **gnpp) 2628 { 2629 zio_gang_node_t *gn = *gnpp; 2630 2631 if (gn == NULL) 2632 return; 2633 2634 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 2635 zio_gang_tree_free(&gn->gn_child[g]); 2636 2637 zio_gang_node_free(gnpp); 2638 } 2639 2640 static void 2641 zio_gang_tree_assemble(zio_t *gio, blkptr_t *bp, zio_gang_node_t **gnpp) 2642 { 2643 zio_gang_node_t *gn = zio_gang_node_alloc(gnpp); 2644 abd_t *gbh_abd = abd_get_from_buf(gn->gn_gbh, SPA_GANGBLOCKSIZE); 2645 2646 ASSERT(gio->io_gang_leader == gio); 2647 ASSERT(BP_IS_GANG(bp)); 2648 2649 zio_nowait(zio_read(gio, gio->io_spa, bp, gbh_abd, SPA_GANGBLOCKSIZE, 2650 zio_gang_tree_assemble_done, gn, gio->io_priority, 2651 ZIO_GANG_CHILD_FLAGS(gio), &gio->io_bookmark)); 2652 } 2653 2654 static void 2655 zio_gang_tree_assemble_done(zio_t *zio) 2656 { 2657 zio_t *gio = zio->io_gang_leader; 2658 zio_gang_node_t *gn = zio->io_private; 2659 blkptr_t *bp = zio->io_bp; 2660 2661 ASSERT(gio == zio_unique_parent(zio)); 2662 ASSERT(zio->io_child_count == 0); 2663 2664 if (zio->io_error) 2665 return; 2666 2667 /* this ABD was created from a linear buf in zio_gang_tree_assemble */ 2668 if (BP_SHOULD_BYTESWAP(bp)) 2669 byteswap_uint64_array(abd_to_buf(zio->io_abd), zio->io_size); 2670 2671 ASSERT3P(abd_to_buf(zio->io_abd), ==, gn->gn_gbh); 2672 ASSERT(zio->io_size == SPA_GANGBLOCKSIZE); 2673 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 2674 2675 abd_free(zio->io_abd); 2676 2677 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 2678 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 2679 if (!BP_IS_GANG(gbp)) 2680 continue; 2681 zio_gang_tree_assemble(gio, gbp, &gn->gn_child[g]); 2682 } 2683 } 2684 2685 static void 2686 zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, abd_t *data, 2687 uint64_t offset) 2688 { 2689 zio_t *gio = pio->io_gang_leader; 2690 zio_t *zio; 2691 2692 ASSERT(BP_IS_GANG(bp) == !!gn); 2693 ASSERT(BP_GET_CHECKSUM(bp) == BP_GET_CHECKSUM(gio->io_bp)); 2694 ASSERT(BP_GET_LSIZE(bp) == BP_GET_PSIZE(bp) || gn == gio->io_gang_tree); 2695 2696 /* 2697 * If you're a gang header, your data is in gn->gn_gbh. 2698 * If you're a gang member, your data is in 'data' and gn == NULL. 2699 */ 2700 zio = zio_gang_issue_func[gio->io_type](pio, bp, gn, data, offset); 2701 2702 if (gn != NULL) { 2703 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 2704 2705 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 2706 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 2707 if (BP_IS_HOLE(gbp)) 2708 continue; 2709 zio_gang_tree_issue(zio, gn->gn_child[g], gbp, data, 2710 offset); 2711 offset += BP_GET_PSIZE(gbp); 2712 } 2713 } 2714 2715 if (gn == gio->io_gang_tree) 2716 ASSERT3U(gio->io_size, ==, offset); 2717 2718 if (zio != pio) 2719 zio_nowait(zio); 2720 } 2721 2722 static zio_t * 2723 zio_gang_assemble(zio_t *zio) 2724 { 2725 blkptr_t *bp = zio->io_bp; 2726 2727 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == NULL); 2728 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2729 2730 zio->io_gang_leader = zio; 2731 2732 zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree); 2733 2734 return (zio); 2735 } 2736 2737 static zio_t * 2738 zio_gang_issue(zio_t *zio) 2739 { 2740 blkptr_t *bp = zio->io_bp; 2741 2742 if (zio_wait_for_children(zio, ZIO_CHILD_GANG_BIT, ZIO_WAIT_DONE)) { 2743 return (NULL); 2744 } 2745 2746 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio); 2747 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2748 2749 if (zio->io_child_error[ZIO_CHILD_GANG] == 0) 2750 zio_gang_tree_issue(zio, zio->io_gang_tree, bp, zio->io_abd, 2751 0); 2752 else 2753 zio_gang_tree_free(&zio->io_gang_tree); 2754 2755 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2756 2757 return (zio); 2758 } 2759 2760 static void 2761 zio_write_gang_member_ready(zio_t *zio) 2762 { 2763 zio_t *pio = zio_unique_parent(zio); 2764 dva_t *cdva = zio->io_bp->blk_dva; 2765 dva_t *pdva = pio->io_bp->blk_dva; 2766 uint64_t asize; 2767 zio_t *gio __maybe_unused = zio->io_gang_leader; 2768 2769 if (BP_IS_HOLE(zio->io_bp)) 2770 return; 2771 2772 ASSERT(BP_IS_HOLE(&zio->io_bp_orig)); 2773 2774 ASSERT(zio->io_child_type == ZIO_CHILD_GANG); 2775 ASSERT3U(zio->io_prop.zp_copies, ==, gio->io_prop.zp_copies); 2776 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp)); 2777 ASSERT3U(pio->io_prop.zp_copies, <=, BP_GET_NDVAS(pio->io_bp)); 2778 ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp)); 2779 2780 mutex_enter(&pio->io_lock); 2781 for (int d = 0; d < BP_GET_NDVAS(zio->io_bp); d++) { 2782 ASSERT(DVA_GET_GANG(&pdva[d])); 2783 asize = DVA_GET_ASIZE(&pdva[d]); 2784 asize += DVA_GET_ASIZE(&cdva[d]); 2785 DVA_SET_ASIZE(&pdva[d], asize); 2786 } 2787 mutex_exit(&pio->io_lock); 2788 } 2789 2790 static void 2791 zio_write_gang_done(zio_t *zio) 2792 { 2793 /* 2794 * The io_abd field will be NULL for a zio with no data. The io_flags 2795 * will initially have the ZIO_FLAG_NODATA bit flag set, but we can't 2796 * check for it here as it is cleared in zio_ready. 2797 */ 2798 if (zio->io_abd != NULL) 2799 abd_free(zio->io_abd); 2800 } 2801 2802 static zio_t * 2803 zio_write_gang_block(zio_t *pio, metaslab_class_t *mc) 2804 { 2805 spa_t *spa = pio->io_spa; 2806 blkptr_t *bp = pio->io_bp; 2807 zio_t *gio = pio->io_gang_leader; 2808 zio_t *zio; 2809 zio_gang_node_t *gn, **gnpp; 2810 zio_gbh_phys_t *gbh; 2811 abd_t *gbh_abd; 2812 uint64_t txg = pio->io_txg; 2813 uint64_t resid = pio->io_size; 2814 uint64_t lsize; 2815 int copies = gio->io_prop.zp_copies; 2816 int gbh_copies; 2817 zio_prop_t zp; 2818 int error; 2819 boolean_t has_data = !(pio->io_flags & ZIO_FLAG_NODATA); 2820 2821 /* 2822 * encrypted blocks need DVA[2] free so encrypted gang headers can't 2823 * have a third copy. 2824 */ 2825 gbh_copies = MIN(copies + 1, spa_max_replication(spa)); 2826 if (gio->io_prop.zp_encrypt && gbh_copies >= SPA_DVAS_PER_BP) 2827 gbh_copies = SPA_DVAS_PER_BP - 1; 2828 2829 int flags = METASLAB_HINTBP_FAVOR | METASLAB_GANG_HEADER; 2830 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 2831 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 2832 ASSERT(has_data); 2833 2834 flags |= METASLAB_ASYNC_ALLOC; 2835 VERIFY(zfs_refcount_held(&mc->mc_allocator[pio->io_allocator]. 2836 mca_alloc_slots, pio)); 2837 2838 /* 2839 * The logical zio has already placed a reservation for 2840 * 'copies' allocation slots but gang blocks may require 2841 * additional copies. These additional copies 2842 * (i.e. gbh_copies - copies) are guaranteed to succeed 2843 * since metaslab_class_throttle_reserve() always allows 2844 * additional reservations for gang blocks. 2845 */ 2846 VERIFY(metaslab_class_throttle_reserve(mc, gbh_copies - copies, 2847 pio->io_allocator, pio, flags)); 2848 } 2849 2850 error = metaslab_alloc(spa, mc, SPA_GANGBLOCKSIZE, 2851 bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp, flags, 2852 &pio->io_alloc_list, pio, pio->io_allocator); 2853 if (error) { 2854 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 2855 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 2856 ASSERT(has_data); 2857 2858 /* 2859 * If we failed to allocate the gang block header then 2860 * we remove any additional allocation reservations that 2861 * we placed here. The original reservation will 2862 * be removed when the logical I/O goes to the ready 2863 * stage. 2864 */ 2865 metaslab_class_throttle_unreserve(mc, 2866 gbh_copies - copies, pio->io_allocator, pio); 2867 } 2868 2869 pio->io_error = error; 2870 return (pio); 2871 } 2872 2873 if (pio == gio) { 2874 gnpp = &gio->io_gang_tree; 2875 } else { 2876 gnpp = pio->io_private; 2877 ASSERT(pio->io_ready == zio_write_gang_member_ready); 2878 } 2879 2880 gn = zio_gang_node_alloc(gnpp); 2881 gbh = gn->gn_gbh; 2882 memset(gbh, 0, SPA_GANGBLOCKSIZE); 2883 gbh_abd = abd_get_from_buf(gbh, SPA_GANGBLOCKSIZE); 2884 2885 /* 2886 * Create the gang header. 2887 */ 2888 zio = zio_rewrite(pio, spa, txg, bp, gbh_abd, SPA_GANGBLOCKSIZE, 2889 zio_write_gang_done, NULL, pio->io_priority, 2890 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 2891 2892 /* 2893 * Create and nowait the gang children. 2894 */ 2895 for (int g = 0; resid != 0; resid -= lsize, g++) { 2896 lsize = P2ROUNDUP(resid / (SPA_GBH_NBLKPTRS - g), 2897 SPA_MINBLOCKSIZE); 2898 ASSERT(lsize >= SPA_MINBLOCKSIZE && lsize <= resid); 2899 2900 zp.zp_checksum = gio->io_prop.zp_checksum; 2901 zp.zp_compress = ZIO_COMPRESS_OFF; 2902 zp.zp_complevel = gio->io_prop.zp_complevel; 2903 zp.zp_type = DMU_OT_NONE; 2904 zp.zp_level = 0; 2905 zp.zp_copies = gio->io_prop.zp_copies; 2906 zp.zp_dedup = B_FALSE; 2907 zp.zp_dedup_verify = B_FALSE; 2908 zp.zp_nopwrite = B_FALSE; 2909 zp.zp_encrypt = gio->io_prop.zp_encrypt; 2910 zp.zp_byteorder = gio->io_prop.zp_byteorder; 2911 memset(zp.zp_salt, 0, ZIO_DATA_SALT_LEN); 2912 memset(zp.zp_iv, 0, ZIO_DATA_IV_LEN); 2913 memset(zp.zp_mac, 0, ZIO_DATA_MAC_LEN); 2914 2915 zio_t *cio = zio_write(zio, spa, txg, &gbh->zg_blkptr[g], 2916 has_data ? abd_get_offset(pio->io_abd, pio->io_size - 2917 resid) : NULL, lsize, lsize, &zp, 2918 zio_write_gang_member_ready, NULL, NULL, 2919 zio_write_gang_done, &gn->gn_child[g], pio->io_priority, 2920 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 2921 2922 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 2923 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 2924 ASSERT(has_data); 2925 2926 /* 2927 * Gang children won't throttle but we should 2928 * account for their work, so reserve an allocation 2929 * slot for them here. 2930 */ 2931 VERIFY(metaslab_class_throttle_reserve(mc, 2932 zp.zp_copies, cio->io_allocator, cio, flags)); 2933 } 2934 zio_nowait(cio); 2935 } 2936 2937 /* 2938 * Set pio's pipeline to just wait for zio to finish. 2939 */ 2940 pio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2941 2942 /* 2943 * We didn't allocate this bp, so make sure it doesn't get unmarked. 2944 */ 2945 pio->io_flags &= ~ZIO_FLAG_FASTWRITE; 2946 2947 zio_nowait(zio); 2948 2949 return (pio); 2950 } 2951 2952 /* 2953 * The zio_nop_write stage in the pipeline determines if allocating a 2954 * new bp is necessary. The nopwrite feature can handle writes in 2955 * either syncing or open context (i.e. zil writes) and as a result is 2956 * mutually exclusive with dedup. 2957 * 2958 * By leveraging a cryptographically secure checksum, such as SHA256, we 2959 * can compare the checksums of the new data and the old to determine if 2960 * allocating a new block is required. Note that our requirements for 2961 * cryptographic strength are fairly weak: there can't be any accidental 2962 * hash collisions, but we don't need to be secure against intentional 2963 * (malicious) collisions. To trigger a nopwrite, you have to be able 2964 * to write the file to begin with, and triggering an incorrect (hash 2965 * collision) nopwrite is no worse than simply writing to the file. 2966 * That said, there are no known attacks against the checksum algorithms 2967 * used for nopwrite, assuming that the salt and the checksums 2968 * themselves remain secret. 2969 */ 2970 static zio_t * 2971 zio_nop_write(zio_t *zio) 2972 { 2973 blkptr_t *bp = zio->io_bp; 2974 blkptr_t *bp_orig = &zio->io_bp_orig; 2975 zio_prop_t *zp = &zio->io_prop; 2976 2977 ASSERT(BP_GET_LEVEL(bp) == 0); 2978 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 2979 ASSERT(zp->zp_nopwrite); 2980 ASSERT(!zp->zp_dedup); 2981 ASSERT(zio->io_bp_override == NULL); 2982 ASSERT(IO_IS_ALLOCATING(zio)); 2983 2984 /* 2985 * Check to see if the original bp and the new bp have matching 2986 * characteristics (i.e. same checksum, compression algorithms, etc). 2987 * If they don't then just continue with the pipeline which will 2988 * allocate a new bp. 2989 */ 2990 if (BP_IS_HOLE(bp_orig) || 2991 !(zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_flags & 2992 ZCHECKSUM_FLAG_NOPWRITE) || 2993 BP_IS_ENCRYPTED(bp) || BP_IS_ENCRYPTED(bp_orig) || 2994 BP_GET_CHECKSUM(bp) != BP_GET_CHECKSUM(bp_orig) || 2995 BP_GET_COMPRESS(bp) != BP_GET_COMPRESS(bp_orig) || 2996 BP_GET_DEDUP(bp) != BP_GET_DEDUP(bp_orig) || 2997 zp->zp_copies != BP_GET_NDVAS(bp_orig)) 2998 return (zio); 2999 3000 /* 3001 * If the checksums match then reset the pipeline so that we 3002 * avoid allocating a new bp and issuing any I/O. 3003 */ 3004 if (ZIO_CHECKSUM_EQUAL(bp->blk_cksum, bp_orig->blk_cksum)) { 3005 ASSERT(zio_checksum_table[zp->zp_checksum].ci_flags & 3006 ZCHECKSUM_FLAG_NOPWRITE); 3007 ASSERT3U(BP_GET_PSIZE(bp), ==, BP_GET_PSIZE(bp_orig)); 3008 ASSERT3U(BP_GET_LSIZE(bp), ==, BP_GET_LSIZE(bp_orig)); 3009 ASSERT(zp->zp_compress != ZIO_COMPRESS_OFF); 3010 ASSERT(memcmp(&bp->blk_prop, &bp_orig->blk_prop, 3011 sizeof (uint64_t)) == 0); 3012 3013 /* 3014 * If we're overwriting a block that is currently on an 3015 * indirect vdev, then ignore the nopwrite request and 3016 * allow a new block to be allocated on a concrete vdev. 3017 */ 3018 spa_config_enter(zio->io_spa, SCL_VDEV, FTAG, RW_READER); 3019 vdev_t *tvd = vdev_lookup_top(zio->io_spa, 3020 DVA_GET_VDEV(&bp->blk_dva[0])); 3021 if (tvd->vdev_ops == &vdev_indirect_ops) { 3022 spa_config_exit(zio->io_spa, SCL_VDEV, FTAG); 3023 return (zio); 3024 } 3025 spa_config_exit(zio->io_spa, SCL_VDEV, FTAG); 3026 3027 *bp = *bp_orig; 3028 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 3029 zio->io_flags |= ZIO_FLAG_NOPWRITE; 3030 } 3031 3032 return (zio); 3033 } 3034 3035 /* 3036 * ========================================================================== 3037 * Dedup 3038 * ========================================================================== 3039 */ 3040 static void 3041 zio_ddt_child_read_done(zio_t *zio) 3042 { 3043 blkptr_t *bp = zio->io_bp; 3044 ddt_entry_t *dde = zio->io_private; 3045 ddt_phys_t *ddp; 3046 zio_t *pio = zio_unique_parent(zio); 3047 3048 mutex_enter(&pio->io_lock); 3049 ddp = ddt_phys_select(dde, bp); 3050 if (zio->io_error == 0) 3051 ddt_phys_clear(ddp); /* this ddp doesn't need repair */ 3052 3053 if (zio->io_error == 0 && dde->dde_repair_abd == NULL) 3054 dde->dde_repair_abd = zio->io_abd; 3055 else 3056 abd_free(zio->io_abd); 3057 mutex_exit(&pio->io_lock); 3058 } 3059 3060 static zio_t * 3061 zio_ddt_read_start(zio_t *zio) 3062 { 3063 blkptr_t *bp = zio->io_bp; 3064 3065 ASSERT(BP_GET_DEDUP(bp)); 3066 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 3067 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3068 3069 if (zio->io_child_error[ZIO_CHILD_DDT]) { 3070 ddt_t *ddt = ddt_select(zio->io_spa, bp); 3071 ddt_entry_t *dde = ddt_repair_start(ddt, bp); 3072 ddt_phys_t *ddp = dde->dde_phys; 3073 ddt_phys_t *ddp_self = ddt_phys_select(dde, bp); 3074 blkptr_t blk; 3075 3076 ASSERT(zio->io_vsd == NULL); 3077 zio->io_vsd = dde; 3078 3079 if (ddp_self == NULL) 3080 return (zio); 3081 3082 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { 3083 if (ddp->ddp_phys_birth == 0 || ddp == ddp_self) 3084 continue; 3085 ddt_bp_create(ddt->ddt_checksum, &dde->dde_key, ddp, 3086 &blk); 3087 zio_nowait(zio_read(zio, zio->io_spa, &blk, 3088 abd_alloc_for_io(zio->io_size, B_TRUE), 3089 zio->io_size, zio_ddt_child_read_done, dde, 3090 zio->io_priority, ZIO_DDT_CHILD_FLAGS(zio) | 3091 ZIO_FLAG_DONT_PROPAGATE, &zio->io_bookmark)); 3092 } 3093 return (zio); 3094 } 3095 3096 zio_nowait(zio_read(zio, zio->io_spa, bp, 3097 zio->io_abd, zio->io_size, NULL, NULL, zio->io_priority, 3098 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark)); 3099 3100 return (zio); 3101 } 3102 3103 static zio_t * 3104 zio_ddt_read_done(zio_t *zio) 3105 { 3106 blkptr_t *bp = zio->io_bp; 3107 3108 if (zio_wait_for_children(zio, ZIO_CHILD_DDT_BIT, ZIO_WAIT_DONE)) { 3109 return (NULL); 3110 } 3111 3112 ASSERT(BP_GET_DEDUP(bp)); 3113 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 3114 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3115 3116 if (zio->io_child_error[ZIO_CHILD_DDT]) { 3117 ddt_t *ddt = ddt_select(zio->io_spa, bp); 3118 ddt_entry_t *dde = zio->io_vsd; 3119 if (ddt == NULL) { 3120 ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE); 3121 return (zio); 3122 } 3123 if (dde == NULL) { 3124 zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1; 3125 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 3126 return (NULL); 3127 } 3128 if (dde->dde_repair_abd != NULL) { 3129 abd_copy(zio->io_abd, dde->dde_repair_abd, 3130 zio->io_size); 3131 zio->io_child_error[ZIO_CHILD_DDT] = 0; 3132 } 3133 ddt_repair_done(ddt, dde); 3134 zio->io_vsd = NULL; 3135 } 3136 3137 ASSERT(zio->io_vsd == NULL); 3138 3139 return (zio); 3140 } 3141 3142 static boolean_t 3143 zio_ddt_collision(zio_t *zio, ddt_t *ddt, ddt_entry_t *dde) 3144 { 3145 spa_t *spa = zio->io_spa; 3146 boolean_t do_raw = !!(zio->io_flags & ZIO_FLAG_RAW); 3147 3148 ASSERT(!(zio->io_bp_override && do_raw)); 3149 3150 /* 3151 * Note: we compare the original data, not the transformed data, 3152 * because when zio->io_bp is an override bp, we will not have 3153 * pushed the I/O transforms. That's an important optimization 3154 * because otherwise we'd compress/encrypt all dmu_sync() data twice. 3155 * However, we should never get a raw, override zio so in these 3156 * cases we can compare the io_abd directly. This is useful because 3157 * it allows us to do dedup verification even if we don't have access 3158 * to the original data (for instance, if the encryption keys aren't 3159 * loaded). 3160 */ 3161 3162 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 3163 zio_t *lio = dde->dde_lead_zio[p]; 3164 3165 if (lio != NULL && do_raw) { 3166 return (lio->io_size != zio->io_size || 3167 abd_cmp(zio->io_abd, lio->io_abd) != 0); 3168 } else if (lio != NULL) { 3169 return (lio->io_orig_size != zio->io_orig_size || 3170 abd_cmp(zio->io_orig_abd, lio->io_orig_abd) != 0); 3171 } 3172 } 3173 3174 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 3175 ddt_phys_t *ddp = &dde->dde_phys[p]; 3176 3177 if (ddp->ddp_phys_birth != 0 && do_raw) { 3178 blkptr_t blk = *zio->io_bp; 3179 uint64_t psize; 3180 abd_t *tmpabd; 3181 int error; 3182 3183 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth); 3184 psize = BP_GET_PSIZE(&blk); 3185 3186 if (psize != zio->io_size) 3187 return (B_TRUE); 3188 3189 ddt_exit(ddt); 3190 3191 tmpabd = abd_alloc_for_io(psize, B_TRUE); 3192 3193 error = zio_wait(zio_read(NULL, spa, &blk, tmpabd, 3194 psize, NULL, NULL, ZIO_PRIORITY_SYNC_READ, 3195 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | 3196 ZIO_FLAG_RAW, &zio->io_bookmark)); 3197 3198 if (error == 0) { 3199 if (abd_cmp(tmpabd, zio->io_abd) != 0) 3200 error = SET_ERROR(ENOENT); 3201 } 3202 3203 abd_free(tmpabd); 3204 ddt_enter(ddt); 3205 return (error != 0); 3206 } else if (ddp->ddp_phys_birth != 0) { 3207 arc_buf_t *abuf = NULL; 3208 arc_flags_t aflags = ARC_FLAG_WAIT; 3209 blkptr_t blk = *zio->io_bp; 3210 int error; 3211 3212 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth); 3213 3214 if (BP_GET_LSIZE(&blk) != zio->io_orig_size) 3215 return (B_TRUE); 3216 3217 ddt_exit(ddt); 3218 3219 error = arc_read(NULL, spa, &blk, 3220 arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ, 3221 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, 3222 &aflags, &zio->io_bookmark); 3223 3224 if (error == 0) { 3225 if (abd_cmp_buf(zio->io_orig_abd, abuf->b_data, 3226 zio->io_orig_size) != 0) 3227 error = SET_ERROR(ENOENT); 3228 arc_buf_destroy(abuf, &abuf); 3229 } 3230 3231 ddt_enter(ddt); 3232 return (error != 0); 3233 } 3234 } 3235 3236 return (B_FALSE); 3237 } 3238 3239 static void 3240 zio_ddt_child_write_ready(zio_t *zio) 3241 { 3242 int p = zio->io_prop.zp_copies; 3243 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 3244 ddt_entry_t *dde = zio->io_private; 3245 ddt_phys_t *ddp = &dde->dde_phys[p]; 3246 zio_t *pio; 3247 3248 if (zio->io_error) 3249 return; 3250 3251 ddt_enter(ddt); 3252 3253 ASSERT(dde->dde_lead_zio[p] == zio); 3254 3255 ddt_phys_fill(ddp, zio->io_bp); 3256 3257 zio_link_t *zl = NULL; 3258 while ((pio = zio_walk_parents(zio, &zl)) != NULL) 3259 ddt_bp_fill(ddp, pio->io_bp, zio->io_txg); 3260 3261 ddt_exit(ddt); 3262 } 3263 3264 static void 3265 zio_ddt_child_write_done(zio_t *zio) 3266 { 3267 int p = zio->io_prop.zp_copies; 3268 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 3269 ddt_entry_t *dde = zio->io_private; 3270 ddt_phys_t *ddp = &dde->dde_phys[p]; 3271 3272 ddt_enter(ddt); 3273 3274 ASSERT(ddp->ddp_refcnt == 0); 3275 ASSERT(dde->dde_lead_zio[p] == zio); 3276 dde->dde_lead_zio[p] = NULL; 3277 3278 if (zio->io_error == 0) { 3279 zio_link_t *zl = NULL; 3280 while (zio_walk_parents(zio, &zl) != NULL) 3281 ddt_phys_addref(ddp); 3282 } else { 3283 ddt_phys_clear(ddp); 3284 } 3285 3286 ddt_exit(ddt); 3287 } 3288 3289 static zio_t * 3290 zio_ddt_write(zio_t *zio) 3291 { 3292 spa_t *spa = zio->io_spa; 3293 blkptr_t *bp = zio->io_bp; 3294 uint64_t txg = zio->io_txg; 3295 zio_prop_t *zp = &zio->io_prop; 3296 int p = zp->zp_copies; 3297 zio_t *cio = NULL; 3298 ddt_t *ddt = ddt_select(spa, bp); 3299 ddt_entry_t *dde; 3300 ddt_phys_t *ddp; 3301 3302 ASSERT(BP_GET_DEDUP(bp)); 3303 ASSERT(BP_GET_CHECKSUM(bp) == zp->zp_checksum); 3304 ASSERT(BP_IS_HOLE(bp) || zio->io_bp_override); 3305 ASSERT(!(zio->io_bp_override && (zio->io_flags & ZIO_FLAG_RAW))); 3306 3307 ddt_enter(ddt); 3308 dde = ddt_lookup(ddt, bp, B_TRUE); 3309 ddp = &dde->dde_phys[p]; 3310 3311 if (zp->zp_dedup_verify && zio_ddt_collision(zio, ddt, dde)) { 3312 /* 3313 * If we're using a weak checksum, upgrade to a strong checksum 3314 * and try again. If we're already using a strong checksum, 3315 * we can't resolve it, so just convert to an ordinary write. 3316 * (And automatically e-mail a paper to Nature?) 3317 */ 3318 if (!(zio_checksum_table[zp->zp_checksum].ci_flags & 3319 ZCHECKSUM_FLAG_DEDUP)) { 3320 zp->zp_checksum = spa_dedup_checksum(spa); 3321 zio_pop_transforms(zio); 3322 zio->io_stage = ZIO_STAGE_OPEN; 3323 BP_ZERO(bp); 3324 } else { 3325 zp->zp_dedup = B_FALSE; 3326 BP_SET_DEDUP(bp, B_FALSE); 3327 } 3328 ASSERT(!BP_GET_DEDUP(bp)); 3329 zio->io_pipeline = ZIO_WRITE_PIPELINE; 3330 ddt_exit(ddt); 3331 return (zio); 3332 } 3333 3334 if (ddp->ddp_phys_birth != 0 || dde->dde_lead_zio[p] != NULL) { 3335 if (ddp->ddp_phys_birth != 0) 3336 ddt_bp_fill(ddp, bp, txg); 3337 if (dde->dde_lead_zio[p] != NULL) 3338 zio_add_child(zio, dde->dde_lead_zio[p]); 3339 else 3340 ddt_phys_addref(ddp); 3341 } else if (zio->io_bp_override) { 3342 ASSERT(bp->blk_birth == txg); 3343 ASSERT(BP_EQUAL(bp, zio->io_bp_override)); 3344 ddt_phys_fill(ddp, bp); 3345 ddt_phys_addref(ddp); 3346 } else { 3347 cio = zio_write(zio, spa, txg, bp, zio->io_orig_abd, 3348 zio->io_orig_size, zio->io_orig_size, zp, 3349 zio_ddt_child_write_ready, NULL, NULL, 3350 zio_ddt_child_write_done, dde, zio->io_priority, 3351 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 3352 3353 zio_push_transform(cio, zio->io_abd, zio->io_size, 0, NULL); 3354 dde->dde_lead_zio[p] = cio; 3355 } 3356 3357 ddt_exit(ddt); 3358 3359 zio_nowait(cio); 3360 3361 return (zio); 3362 } 3363 3364 static ddt_entry_t *freedde; /* for debugging */ 3365 3366 static zio_t * 3367 zio_ddt_free(zio_t *zio) 3368 { 3369 spa_t *spa = zio->io_spa; 3370 blkptr_t *bp = zio->io_bp; 3371 ddt_t *ddt = ddt_select(spa, bp); 3372 ddt_entry_t *dde; 3373 ddt_phys_t *ddp; 3374 3375 ASSERT(BP_GET_DEDUP(bp)); 3376 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3377 3378 ddt_enter(ddt); 3379 freedde = dde = ddt_lookup(ddt, bp, B_TRUE); 3380 if (dde) { 3381 ddp = ddt_phys_select(dde, bp); 3382 if (ddp) 3383 ddt_phys_decref(ddp); 3384 } 3385 ddt_exit(ddt); 3386 3387 return (zio); 3388 } 3389 3390 /* 3391 * ========================================================================== 3392 * Allocate and free blocks 3393 * ========================================================================== 3394 */ 3395 3396 static zio_t * 3397 zio_io_to_allocate(spa_t *spa, int allocator) 3398 { 3399 zio_t *zio; 3400 3401 ASSERT(MUTEX_HELD(&spa->spa_allocs[allocator].spaa_lock)); 3402 3403 zio = avl_first(&spa->spa_allocs[allocator].spaa_tree); 3404 if (zio == NULL) 3405 return (NULL); 3406 3407 ASSERT(IO_IS_ALLOCATING(zio)); 3408 3409 /* 3410 * Try to place a reservation for this zio. If we're unable to 3411 * reserve then we throttle. 3412 */ 3413 ASSERT3U(zio->io_allocator, ==, allocator); 3414 if (!metaslab_class_throttle_reserve(zio->io_metaslab_class, 3415 zio->io_prop.zp_copies, allocator, zio, 0)) { 3416 return (NULL); 3417 } 3418 3419 avl_remove(&spa->spa_allocs[allocator].spaa_tree, zio); 3420 ASSERT3U(zio->io_stage, <, ZIO_STAGE_DVA_ALLOCATE); 3421 3422 return (zio); 3423 } 3424 3425 static zio_t * 3426 zio_dva_throttle(zio_t *zio) 3427 { 3428 spa_t *spa = zio->io_spa; 3429 zio_t *nio; 3430 metaslab_class_t *mc; 3431 3432 /* locate an appropriate allocation class */ 3433 mc = spa_preferred_class(spa, zio->io_size, zio->io_prop.zp_type, 3434 zio->io_prop.zp_level, zio->io_prop.zp_zpl_smallblk); 3435 3436 if (zio->io_priority == ZIO_PRIORITY_SYNC_WRITE || 3437 !mc->mc_alloc_throttle_enabled || 3438 zio->io_child_type == ZIO_CHILD_GANG || 3439 zio->io_flags & ZIO_FLAG_NODATA) { 3440 return (zio); 3441 } 3442 3443 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 3444 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 3445 ASSERT3U(zio->io_queued_timestamp, >, 0); 3446 ASSERT(zio->io_stage == ZIO_STAGE_DVA_THROTTLE); 3447 3448 zbookmark_phys_t *bm = &zio->io_bookmark; 3449 /* 3450 * We want to try to use as many allocators as possible to help improve 3451 * performance, but we also want logically adjacent IOs to be physically 3452 * adjacent to improve sequential read performance. We chunk each object 3453 * into 2^20 block regions, and then hash based on the objset, object, 3454 * level, and region to accomplish both of these goals. 3455 */ 3456 int allocator = (uint_t)cityhash4(bm->zb_objset, bm->zb_object, 3457 bm->zb_level, bm->zb_blkid >> 20) % spa->spa_alloc_count; 3458 zio->io_allocator = allocator; 3459 zio->io_metaslab_class = mc; 3460 mutex_enter(&spa->spa_allocs[allocator].spaa_lock); 3461 avl_add(&spa->spa_allocs[allocator].spaa_tree, zio); 3462 nio = zio_io_to_allocate(spa, allocator); 3463 mutex_exit(&spa->spa_allocs[allocator].spaa_lock); 3464 return (nio); 3465 } 3466 3467 static void 3468 zio_allocate_dispatch(spa_t *spa, int allocator) 3469 { 3470 zio_t *zio; 3471 3472 mutex_enter(&spa->spa_allocs[allocator].spaa_lock); 3473 zio = zio_io_to_allocate(spa, allocator); 3474 mutex_exit(&spa->spa_allocs[allocator].spaa_lock); 3475 if (zio == NULL) 3476 return; 3477 3478 ASSERT3U(zio->io_stage, ==, ZIO_STAGE_DVA_THROTTLE); 3479 ASSERT0(zio->io_error); 3480 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_TRUE); 3481 } 3482 3483 static zio_t * 3484 zio_dva_allocate(zio_t *zio) 3485 { 3486 spa_t *spa = zio->io_spa; 3487 metaslab_class_t *mc; 3488 blkptr_t *bp = zio->io_bp; 3489 int error; 3490 int flags = 0; 3491 3492 if (zio->io_gang_leader == NULL) { 3493 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 3494 zio->io_gang_leader = zio; 3495 } 3496 3497 ASSERT(BP_IS_HOLE(bp)); 3498 ASSERT0(BP_GET_NDVAS(bp)); 3499 ASSERT3U(zio->io_prop.zp_copies, >, 0); 3500 ASSERT3U(zio->io_prop.zp_copies, <=, spa_max_replication(spa)); 3501 ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp)); 3502 3503 flags |= (zio->io_flags & ZIO_FLAG_FASTWRITE) ? METASLAB_FASTWRITE : 0; 3504 if (zio->io_flags & ZIO_FLAG_NODATA) 3505 flags |= METASLAB_DONT_THROTTLE; 3506 if (zio->io_flags & ZIO_FLAG_GANG_CHILD) 3507 flags |= METASLAB_GANG_CHILD; 3508 if (zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE) 3509 flags |= METASLAB_ASYNC_ALLOC; 3510 3511 /* 3512 * if not already chosen, locate an appropriate allocation class 3513 */ 3514 mc = zio->io_metaslab_class; 3515 if (mc == NULL) { 3516 mc = spa_preferred_class(spa, zio->io_size, 3517 zio->io_prop.zp_type, zio->io_prop.zp_level, 3518 zio->io_prop.zp_zpl_smallblk); 3519 zio->io_metaslab_class = mc; 3520 } 3521 3522 /* 3523 * Try allocating the block in the usual metaslab class. 3524 * If that's full, allocate it in the normal class. 3525 * If that's full, allocate as a gang block, 3526 * and if all are full, the allocation fails (which shouldn't happen). 3527 * 3528 * Note that we do not fall back on embedded slog (ZIL) space, to 3529 * preserve unfragmented slog space, which is critical for decent 3530 * sync write performance. If a log allocation fails, we will fall 3531 * back to spa_sync() which is abysmal for performance. 3532 */ 3533 error = metaslab_alloc(spa, mc, zio->io_size, bp, 3534 zio->io_prop.zp_copies, zio->io_txg, NULL, flags, 3535 &zio->io_alloc_list, zio, zio->io_allocator); 3536 3537 /* 3538 * Fallback to normal class when an alloc class is full 3539 */ 3540 if (error == ENOSPC && mc != spa_normal_class(spa)) { 3541 /* 3542 * If throttling, transfer reservation over to normal class. 3543 * The io_allocator slot can remain the same even though we 3544 * are switching classes. 3545 */ 3546 if (mc->mc_alloc_throttle_enabled && 3547 (zio->io_flags & ZIO_FLAG_IO_ALLOCATING)) { 3548 metaslab_class_throttle_unreserve(mc, 3549 zio->io_prop.zp_copies, zio->io_allocator, zio); 3550 zio->io_flags &= ~ZIO_FLAG_IO_ALLOCATING; 3551 3552 VERIFY(metaslab_class_throttle_reserve( 3553 spa_normal_class(spa), 3554 zio->io_prop.zp_copies, zio->io_allocator, zio, 3555 flags | METASLAB_MUST_RESERVE)); 3556 } 3557 zio->io_metaslab_class = mc = spa_normal_class(spa); 3558 if (zfs_flags & ZFS_DEBUG_METASLAB_ALLOC) { 3559 zfs_dbgmsg("%s: metaslab allocation failure, " 3560 "trying normal class: zio %px, size %llu, error %d", 3561 spa_name(spa), zio, (u_longlong_t)zio->io_size, 3562 error); 3563 } 3564 3565 error = metaslab_alloc(spa, mc, zio->io_size, bp, 3566 zio->io_prop.zp_copies, zio->io_txg, NULL, flags, 3567 &zio->io_alloc_list, zio, zio->io_allocator); 3568 } 3569 3570 if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE) { 3571 if (zfs_flags & ZFS_DEBUG_METASLAB_ALLOC) { 3572 zfs_dbgmsg("%s: metaslab allocation failure, " 3573 "trying ganging: zio %px, size %llu, error %d", 3574 spa_name(spa), zio, (u_longlong_t)zio->io_size, 3575 error); 3576 } 3577 return (zio_write_gang_block(zio, mc)); 3578 } 3579 if (error != 0) { 3580 if (error != ENOSPC || 3581 (zfs_flags & ZFS_DEBUG_METASLAB_ALLOC)) { 3582 zfs_dbgmsg("%s: metaslab allocation failure: zio %px, " 3583 "size %llu, error %d", 3584 spa_name(spa), zio, (u_longlong_t)zio->io_size, 3585 error); 3586 } 3587 zio->io_error = error; 3588 } 3589 3590 return (zio); 3591 } 3592 3593 static zio_t * 3594 zio_dva_free(zio_t *zio) 3595 { 3596 metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE); 3597 3598 return (zio); 3599 } 3600 3601 static zio_t * 3602 zio_dva_claim(zio_t *zio) 3603 { 3604 int error; 3605 3606 error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg); 3607 if (error) 3608 zio->io_error = error; 3609 3610 return (zio); 3611 } 3612 3613 /* 3614 * Undo an allocation. This is used by zio_done() when an I/O fails 3615 * and we want to give back the block we just allocated. 3616 * This handles both normal blocks and gang blocks. 3617 */ 3618 static void 3619 zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp) 3620 { 3621 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp)); 3622 ASSERT(zio->io_bp_override == NULL); 3623 3624 if (!BP_IS_HOLE(bp)) 3625 metaslab_free(zio->io_spa, bp, bp->blk_birth, B_TRUE); 3626 3627 if (gn != NULL) { 3628 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 3629 zio_dva_unallocate(zio, gn->gn_child[g], 3630 &gn->gn_gbh->zg_blkptr[g]); 3631 } 3632 } 3633 } 3634 3635 /* 3636 * Try to allocate an intent log block. Return 0 on success, errno on failure. 3637 */ 3638 int 3639 zio_alloc_zil(spa_t *spa, objset_t *os, uint64_t txg, blkptr_t *new_bp, 3640 uint64_t size, boolean_t *slog) 3641 { 3642 int error = 1; 3643 zio_alloc_list_t io_alloc_list; 3644 3645 ASSERT(txg > spa_syncing_txg(spa)); 3646 3647 metaslab_trace_init(&io_alloc_list); 3648 3649 /* 3650 * Block pointer fields are useful to metaslabs for stats and debugging. 3651 * Fill in the obvious ones before calling into metaslab_alloc(). 3652 */ 3653 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG); 3654 BP_SET_PSIZE(new_bp, size); 3655 BP_SET_LEVEL(new_bp, 0); 3656 3657 /* 3658 * When allocating a zil block, we don't have information about 3659 * the final destination of the block except the objset it's part 3660 * of, so we just hash the objset ID to pick the allocator to get 3661 * some parallelism. 3662 */ 3663 int flags = METASLAB_FASTWRITE | METASLAB_ZIL; 3664 int allocator = (uint_t)cityhash4(0, 0, 0, 3665 os->os_dsl_dataset->ds_object) % spa->spa_alloc_count; 3666 error = metaslab_alloc(spa, spa_log_class(spa), size, new_bp, 1, 3667 txg, NULL, flags, &io_alloc_list, NULL, allocator); 3668 *slog = (error == 0); 3669 if (error != 0) { 3670 error = metaslab_alloc(spa, spa_embedded_log_class(spa), size, 3671 new_bp, 1, txg, NULL, flags, 3672 &io_alloc_list, NULL, allocator); 3673 } 3674 if (error != 0) { 3675 error = metaslab_alloc(spa, spa_normal_class(spa), size, 3676 new_bp, 1, txg, NULL, flags, 3677 &io_alloc_list, NULL, allocator); 3678 } 3679 metaslab_trace_fini(&io_alloc_list); 3680 3681 if (error == 0) { 3682 BP_SET_LSIZE(new_bp, size); 3683 BP_SET_PSIZE(new_bp, size); 3684 BP_SET_COMPRESS(new_bp, ZIO_COMPRESS_OFF); 3685 BP_SET_CHECKSUM(new_bp, 3686 spa_version(spa) >= SPA_VERSION_SLIM_ZIL 3687 ? ZIO_CHECKSUM_ZILOG2 : ZIO_CHECKSUM_ZILOG); 3688 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG); 3689 BP_SET_LEVEL(new_bp, 0); 3690 BP_SET_DEDUP(new_bp, 0); 3691 BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER); 3692 3693 /* 3694 * encrypted blocks will require an IV and salt. We generate 3695 * these now since we will not be rewriting the bp at 3696 * rewrite time. 3697 */ 3698 if (os->os_encrypted) { 3699 uint8_t iv[ZIO_DATA_IV_LEN]; 3700 uint8_t salt[ZIO_DATA_SALT_LEN]; 3701 3702 BP_SET_CRYPT(new_bp, B_TRUE); 3703 VERIFY0(spa_crypt_get_salt(spa, 3704 dmu_objset_id(os), salt)); 3705 VERIFY0(zio_crypt_generate_iv(iv)); 3706 3707 zio_crypt_encode_params_bp(new_bp, salt, iv); 3708 } 3709 } else { 3710 zfs_dbgmsg("%s: zil block allocation failure: " 3711 "size %llu, error %d", spa_name(spa), (u_longlong_t)size, 3712 error); 3713 } 3714 3715 return (error); 3716 } 3717 3718 /* 3719 * ========================================================================== 3720 * Read and write to physical devices 3721 * ========================================================================== 3722 */ 3723 3724 /* 3725 * Issue an I/O to the underlying vdev. Typically the issue pipeline 3726 * stops after this stage and will resume upon I/O completion. 3727 * However, there are instances where the vdev layer may need to 3728 * continue the pipeline when an I/O was not issued. Since the I/O 3729 * that was sent to the vdev layer might be different than the one 3730 * currently active in the pipeline (see vdev_queue_io()), we explicitly 3731 * force the underlying vdev layers to call either zio_execute() or 3732 * zio_interrupt() to ensure that the pipeline continues with the correct I/O. 3733 */ 3734 static zio_t * 3735 zio_vdev_io_start(zio_t *zio) 3736 { 3737 vdev_t *vd = zio->io_vd; 3738 uint64_t align; 3739 spa_t *spa = zio->io_spa; 3740 3741 zio->io_delay = 0; 3742 3743 ASSERT(zio->io_error == 0); 3744 ASSERT(zio->io_child_error[ZIO_CHILD_VDEV] == 0); 3745 3746 if (vd == NULL) { 3747 if (!(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 3748 spa_config_enter(spa, SCL_ZIO, zio, RW_READER); 3749 3750 /* 3751 * The mirror_ops handle multiple DVAs in a single BP. 3752 */ 3753 vdev_mirror_ops.vdev_op_io_start(zio); 3754 return (NULL); 3755 } 3756 3757 ASSERT3P(zio->io_logical, !=, zio); 3758 if (zio->io_type == ZIO_TYPE_WRITE) { 3759 ASSERT(spa->spa_trust_config); 3760 3761 /* 3762 * Note: the code can handle other kinds of writes, 3763 * but we don't expect them. 3764 */ 3765 if (zio->io_vd->vdev_noalloc) { 3766 ASSERT(zio->io_flags & 3767 (ZIO_FLAG_PHYSICAL | ZIO_FLAG_SELF_HEAL | 3768 ZIO_FLAG_RESILVER | ZIO_FLAG_INDUCE_DAMAGE)); 3769 } 3770 } 3771 3772 align = 1ULL << vd->vdev_top->vdev_ashift; 3773 3774 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL) && 3775 P2PHASE(zio->io_size, align) != 0) { 3776 /* Transform logical writes to be a full physical block size. */ 3777 uint64_t asize = P2ROUNDUP(zio->io_size, align); 3778 abd_t *abuf = abd_alloc_sametype(zio->io_abd, asize); 3779 ASSERT(vd == vd->vdev_top); 3780 if (zio->io_type == ZIO_TYPE_WRITE) { 3781 abd_copy(abuf, zio->io_abd, zio->io_size); 3782 abd_zero_off(abuf, zio->io_size, asize - zio->io_size); 3783 } 3784 zio_push_transform(zio, abuf, asize, asize, zio_subblock); 3785 } 3786 3787 /* 3788 * If this is not a physical io, make sure that it is properly aligned 3789 * before proceeding. 3790 */ 3791 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL)) { 3792 ASSERT0(P2PHASE(zio->io_offset, align)); 3793 ASSERT0(P2PHASE(zio->io_size, align)); 3794 } else { 3795 /* 3796 * For physical writes, we allow 512b aligned writes and assume 3797 * the device will perform a read-modify-write as necessary. 3798 */ 3799 ASSERT0(P2PHASE(zio->io_offset, SPA_MINBLOCKSIZE)); 3800 ASSERT0(P2PHASE(zio->io_size, SPA_MINBLOCKSIZE)); 3801 } 3802 3803 VERIFY(zio->io_type != ZIO_TYPE_WRITE || spa_writeable(spa)); 3804 3805 /* 3806 * If this is a repair I/O, and there's no self-healing involved -- 3807 * that is, we're just resilvering what we expect to resilver -- 3808 * then don't do the I/O unless zio's txg is actually in vd's DTL. 3809 * This prevents spurious resilvering. 3810 * 3811 * There are a few ways that we can end up creating these spurious 3812 * resilver i/os: 3813 * 3814 * 1. A resilver i/o will be issued if any DVA in the BP has a 3815 * dirty DTL. The mirror code will issue resilver writes to 3816 * each DVA, including the one(s) that are not on vdevs with dirty 3817 * DTLs. 3818 * 3819 * 2. With nested replication, which happens when we have a 3820 * "replacing" or "spare" vdev that's a child of a mirror or raidz. 3821 * For example, given mirror(replacing(A+B), C), it's likely that 3822 * only A is out of date (it's the new device). In this case, we'll 3823 * read from C, then use the data to resilver A+B -- but we don't 3824 * actually want to resilver B, just A. The top-level mirror has no 3825 * way to know this, so instead we just discard unnecessary repairs 3826 * as we work our way down the vdev tree. 3827 * 3828 * 3. ZTEST also creates mirrors of mirrors, mirrors of raidz, etc. 3829 * The same logic applies to any form of nested replication: ditto 3830 * + mirror, RAID-Z + replacing, etc. 3831 * 3832 * However, indirect vdevs point off to other vdevs which may have 3833 * DTL's, so we never bypass them. The child i/os on concrete vdevs 3834 * will be properly bypassed instead. 3835 * 3836 * Leaf DTL_PARTIAL can be empty when a legitimate write comes from 3837 * a dRAID spare vdev. For example, when a dRAID spare is first 3838 * used, its spare blocks need to be written to but the leaf vdev's 3839 * of such blocks can have empty DTL_PARTIAL. 3840 * 3841 * There seemed no clean way to allow such writes while bypassing 3842 * spurious ones. At this point, just avoid all bypassing for dRAID 3843 * for correctness. 3844 */ 3845 if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) && 3846 !(zio->io_flags & ZIO_FLAG_SELF_HEAL) && 3847 zio->io_txg != 0 && /* not a delegated i/o */ 3848 vd->vdev_ops != &vdev_indirect_ops && 3849 vd->vdev_top->vdev_ops != &vdev_draid_ops && 3850 !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) { 3851 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 3852 zio_vdev_io_bypass(zio); 3853 return (zio); 3854 } 3855 3856 /* 3857 * Select the next best leaf I/O to process. Distributed spares are 3858 * excluded since they dispatch the I/O directly to a leaf vdev after 3859 * applying the dRAID mapping. 3860 */ 3861 if (vd->vdev_ops->vdev_op_leaf && 3862 vd->vdev_ops != &vdev_draid_spare_ops && 3863 (zio->io_type == ZIO_TYPE_READ || 3864 zio->io_type == ZIO_TYPE_WRITE || 3865 zio->io_type == ZIO_TYPE_TRIM)) { 3866 3867 if (zio->io_type == ZIO_TYPE_READ && vdev_cache_read(zio)) 3868 return (zio); 3869 3870 if ((zio = vdev_queue_io(zio)) == NULL) 3871 return (NULL); 3872 3873 if (!vdev_accessible(vd, zio)) { 3874 zio->io_error = SET_ERROR(ENXIO); 3875 zio_interrupt(zio); 3876 return (NULL); 3877 } 3878 zio->io_delay = gethrtime(); 3879 } 3880 3881 vd->vdev_ops->vdev_op_io_start(zio); 3882 return (NULL); 3883 } 3884 3885 static zio_t * 3886 zio_vdev_io_done(zio_t *zio) 3887 { 3888 vdev_t *vd = zio->io_vd; 3889 vdev_ops_t *ops = vd ? vd->vdev_ops : &vdev_mirror_ops; 3890 boolean_t unexpected_error = B_FALSE; 3891 3892 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV_BIT, ZIO_WAIT_DONE)) { 3893 return (NULL); 3894 } 3895 3896 ASSERT(zio->io_type == ZIO_TYPE_READ || 3897 zio->io_type == ZIO_TYPE_WRITE || zio->io_type == ZIO_TYPE_TRIM); 3898 3899 if (zio->io_delay) 3900 zio->io_delay = gethrtime() - zio->io_delay; 3901 3902 if (vd != NULL && vd->vdev_ops->vdev_op_leaf && 3903 vd->vdev_ops != &vdev_draid_spare_ops) { 3904 vdev_queue_io_done(zio); 3905 3906 if (zio->io_type == ZIO_TYPE_WRITE) 3907 vdev_cache_write(zio); 3908 3909 if (zio_injection_enabled && zio->io_error == 0) 3910 zio->io_error = zio_handle_device_injections(vd, zio, 3911 EIO, EILSEQ); 3912 3913 if (zio_injection_enabled && zio->io_error == 0) 3914 zio->io_error = zio_handle_label_injection(zio, EIO); 3915 3916 if (zio->io_error && zio->io_type != ZIO_TYPE_TRIM) { 3917 if (!vdev_accessible(vd, zio)) { 3918 zio->io_error = SET_ERROR(ENXIO); 3919 } else { 3920 unexpected_error = B_TRUE; 3921 } 3922 } 3923 } 3924 3925 ops->vdev_op_io_done(zio); 3926 3927 if (unexpected_error && vd->vdev_remove_wanted == B_FALSE) 3928 VERIFY(vdev_probe(vd, zio) == NULL); 3929 3930 return (zio); 3931 } 3932 3933 /* 3934 * This function is used to change the priority of an existing zio that is 3935 * currently in-flight. This is used by the arc to upgrade priority in the 3936 * event that a demand read is made for a block that is currently queued 3937 * as a scrub or async read IO. Otherwise, the high priority read request 3938 * would end up having to wait for the lower priority IO. 3939 */ 3940 void 3941 zio_change_priority(zio_t *pio, zio_priority_t priority) 3942 { 3943 zio_t *cio, *cio_next; 3944 zio_link_t *zl = NULL; 3945 3946 ASSERT3U(priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); 3947 3948 if (pio->io_vd != NULL && pio->io_vd->vdev_ops->vdev_op_leaf) { 3949 vdev_queue_change_io_priority(pio, priority); 3950 } else { 3951 pio->io_priority = priority; 3952 } 3953 3954 mutex_enter(&pio->io_lock); 3955 for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) { 3956 cio_next = zio_walk_children(pio, &zl); 3957 zio_change_priority(cio, priority); 3958 } 3959 mutex_exit(&pio->io_lock); 3960 } 3961 3962 /* 3963 * For non-raidz ZIOs, we can just copy aside the bad data read from the 3964 * disk, and use that to finish the checksum ereport later. 3965 */ 3966 static void 3967 zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr, 3968 const abd_t *good_buf) 3969 { 3970 /* no processing needed */ 3971 zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE); 3972 } 3973 3974 void 3975 zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr) 3976 { 3977 void *abd = abd_alloc_sametype(zio->io_abd, zio->io_size); 3978 3979 abd_copy(abd, zio->io_abd, zio->io_size); 3980 3981 zcr->zcr_cbinfo = zio->io_size; 3982 zcr->zcr_cbdata = abd; 3983 zcr->zcr_finish = zio_vsd_default_cksum_finish; 3984 zcr->zcr_free = zio_abd_free; 3985 } 3986 3987 static zio_t * 3988 zio_vdev_io_assess(zio_t *zio) 3989 { 3990 vdev_t *vd = zio->io_vd; 3991 3992 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV_BIT, ZIO_WAIT_DONE)) { 3993 return (NULL); 3994 } 3995 3996 if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 3997 spa_config_exit(zio->io_spa, SCL_ZIO, zio); 3998 3999 if (zio->io_vsd != NULL) { 4000 zio->io_vsd_ops->vsd_free(zio); 4001 zio->io_vsd = NULL; 4002 } 4003 4004 if (zio_injection_enabled && zio->io_error == 0) 4005 zio->io_error = zio_handle_fault_injection(zio, EIO); 4006 4007 /* 4008 * If the I/O failed, determine whether we should attempt to retry it. 4009 * 4010 * On retry, we cut in line in the issue queue, since we don't want 4011 * compression/checksumming/etc. work to prevent our (cheap) IO reissue. 4012 */ 4013 if (zio->io_error && vd == NULL && 4014 !(zio->io_flags & (ZIO_FLAG_DONT_RETRY | ZIO_FLAG_IO_RETRY))) { 4015 ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_QUEUE)); /* not a leaf */ 4016 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_BYPASS)); /* not a leaf */ 4017 zio->io_error = 0; 4018 zio->io_flags |= ZIO_FLAG_IO_RETRY | 4019 ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE; 4020 zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1; 4021 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, 4022 zio_requeue_io_start_cut_in_line); 4023 return (NULL); 4024 } 4025 4026 /* 4027 * If we got an error on a leaf device, convert it to ENXIO 4028 * if the device is not accessible at all. 4029 */ 4030 if (zio->io_error && vd != NULL && vd->vdev_ops->vdev_op_leaf && 4031 !vdev_accessible(vd, zio)) 4032 zio->io_error = SET_ERROR(ENXIO); 4033 4034 /* 4035 * If we can't write to an interior vdev (mirror or RAID-Z), 4036 * set vdev_cant_write so that we stop trying to allocate from it. 4037 */ 4038 if (zio->io_error == ENXIO && zio->io_type == ZIO_TYPE_WRITE && 4039 vd != NULL && !vd->vdev_ops->vdev_op_leaf) { 4040 vdev_dbgmsg(vd, "zio_vdev_io_assess(zio=%px) setting " 4041 "cant_write=TRUE due to write failure with ENXIO", 4042 zio); 4043 vd->vdev_cant_write = B_TRUE; 4044 } 4045 4046 /* 4047 * If a cache flush returns ENOTSUP or ENOTTY, we know that no future 4048 * attempts will ever succeed. In this case we set a persistent 4049 * boolean flag so that we don't bother with it in the future. 4050 */ 4051 if ((zio->io_error == ENOTSUP || zio->io_error == ENOTTY) && 4052 zio->io_type == ZIO_TYPE_IOCTL && 4053 zio->io_cmd == DKIOCFLUSHWRITECACHE && vd != NULL) 4054 vd->vdev_nowritecache = B_TRUE; 4055 4056 if (zio->io_error) 4057 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 4058 4059 if (vd != NULL && vd->vdev_ops->vdev_op_leaf && 4060 zio->io_physdone != NULL) { 4061 ASSERT(!(zio->io_flags & ZIO_FLAG_DELEGATED)); 4062 ASSERT(zio->io_child_type == ZIO_CHILD_VDEV); 4063 zio->io_physdone(zio->io_logical); 4064 } 4065 4066 return (zio); 4067 } 4068 4069 void 4070 zio_vdev_io_reissue(zio_t *zio) 4071 { 4072 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 4073 ASSERT(zio->io_error == 0); 4074 4075 zio->io_stage >>= 1; 4076 } 4077 4078 void 4079 zio_vdev_io_redone(zio_t *zio) 4080 { 4081 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE); 4082 4083 zio->io_stage >>= 1; 4084 } 4085 4086 void 4087 zio_vdev_io_bypass(zio_t *zio) 4088 { 4089 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 4090 ASSERT(zio->io_error == 0); 4091 4092 zio->io_flags |= ZIO_FLAG_IO_BYPASS; 4093 zio->io_stage = ZIO_STAGE_VDEV_IO_ASSESS >> 1; 4094 } 4095 4096 /* 4097 * ========================================================================== 4098 * Encrypt and store encryption parameters 4099 * ========================================================================== 4100 */ 4101 4102 4103 /* 4104 * This function is used for ZIO_STAGE_ENCRYPT. It is responsible for 4105 * managing the storage of encryption parameters and passing them to the 4106 * lower-level encryption functions. 4107 */ 4108 static zio_t * 4109 zio_encrypt(zio_t *zio) 4110 { 4111 zio_prop_t *zp = &zio->io_prop; 4112 spa_t *spa = zio->io_spa; 4113 blkptr_t *bp = zio->io_bp; 4114 uint64_t psize = BP_GET_PSIZE(bp); 4115 uint64_t dsobj = zio->io_bookmark.zb_objset; 4116 dmu_object_type_t ot = BP_GET_TYPE(bp); 4117 void *enc_buf = NULL; 4118 abd_t *eabd = NULL; 4119 uint8_t salt[ZIO_DATA_SALT_LEN]; 4120 uint8_t iv[ZIO_DATA_IV_LEN]; 4121 uint8_t mac[ZIO_DATA_MAC_LEN]; 4122 boolean_t no_crypt = B_FALSE; 4123 4124 /* the root zio already encrypted the data */ 4125 if (zio->io_child_type == ZIO_CHILD_GANG) 4126 return (zio); 4127 4128 /* only ZIL blocks are re-encrypted on rewrite */ 4129 if (!IO_IS_ALLOCATING(zio) && ot != DMU_OT_INTENT_LOG) 4130 return (zio); 4131 4132 if (!(zp->zp_encrypt || BP_IS_ENCRYPTED(bp))) { 4133 BP_SET_CRYPT(bp, B_FALSE); 4134 return (zio); 4135 } 4136 4137 /* if we are doing raw encryption set the provided encryption params */ 4138 if (zio->io_flags & ZIO_FLAG_RAW_ENCRYPT) { 4139 ASSERT0(BP_GET_LEVEL(bp)); 4140 BP_SET_CRYPT(bp, B_TRUE); 4141 BP_SET_BYTEORDER(bp, zp->zp_byteorder); 4142 if (ot != DMU_OT_OBJSET) 4143 zio_crypt_encode_mac_bp(bp, zp->zp_mac); 4144 4145 /* dnode blocks must be written out in the provided byteorder */ 4146 if (zp->zp_byteorder != ZFS_HOST_BYTEORDER && 4147 ot == DMU_OT_DNODE) { 4148 void *bswap_buf = zio_buf_alloc(psize); 4149 abd_t *babd = abd_get_from_buf(bswap_buf, psize); 4150 4151 ASSERT3U(BP_GET_COMPRESS(bp), ==, ZIO_COMPRESS_OFF); 4152 abd_copy_to_buf(bswap_buf, zio->io_abd, psize); 4153 dmu_ot_byteswap[DMU_OT_BYTESWAP(ot)].ob_func(bswap_buf, 4154 psize); 4155 4156 abd_take_ownership_of_buf(babd, B_TRUE); 4157 zio_push_transform(zio, babd, psize, psize, NULL); 4158 } 4159 4160 if (DMU_OT_IS_ENCRYPTED(ot)) 4161 zio_crypt_encode_params_bp(bp, zp->zp_salt, zp->zp_iv); 4162 return (zio); 4163 } 4164 4165 /* indirect blocks only maintain a cksum of the lower level MACs */ 4166 if (BP_GET_LEVEL(bp) > 0) { 4167 BP_SET_CRYPT(bp, B_TRUE); 4168 VERIFY0(zio_crypt_do_indirect_mac_checksum_abd(B_TRUE, 4169 zio->io_orig_abd, BP_GET_LSIZE(bp), BP_SHOULD_BYTESWAP(bp), 4170 mac)); 4171 zio_crypt_encode_mac_bp(bp, mac); 4172 return (zio); 4173 } 4174 4175 /* 4176 * Objset blocks are a special case since they have 2 256-bit MACs 4177 * embedded within them. 4178 */ 4179 if (ot == DMU_OT_OBJSET) { 4180 ASSERT0(DMU_OT_IS_ENCRYPTED(ot)); 4181 ASSERT3U(BP_GET_COMPRESS(bp), ==, ZIO_COMPRESS_OFF); 4182 BP_SET_CRYPT(bp, B_TRUE); 4183 VERIFY0(spa_do_crypt_objset_mac_abd(B_TRUE, spa, dsobj, 4184 zio->io_abd, psize, BP_SHOULD_BYTESWAP(bp))); 4185 return (zio); 4186 } 4187 4188 /* unencrypted object types are only authenticated with a MAC */ 4189 if (!DMU_OT_IS_ENCRYPTED(ot)) { 4190 BP_SET_CRYPT(bp, B_TRUE); 4191 VERIFY0(spa_do_crypt_mac_abd(B_TRUE, spa, dsobj, 4192 zio->io_abd, psize, mac)); 4193 zio_crypt_encode_mac_bp(bp, mac); 4194 return (zio); 4195 } 4196 4197 /* 4198 * Later passes of sync-to-convergence may decide to rewrite data 4199 * in place to avoid more disk reallocations. This presents a problem 4200 * for encryption because this constitutes rewriting the new data with 4201 * the same encryption key and IV. However, this only applies to blocks 4202 * in the MOS (particularly the spacemaps) and we do not encrypt the 4203 * MOS. We assert that the zio is allocating or an intent log write 4204 * to enforce this. 4205 */ 4206 ASSERT(IO_IS_ALLOCATING(zio) || ot == DMU_OT_INTENT_LOG); 4207 ASSERT(BP_GET_LEVEL(bp) == 0 || ot == DMU_OT_INTENT_LOG); 4208 ASSERT(spa_feature_is_active(spa, SPA_FEATURE_ENCRYPTION)); 4209 ASSERT3U(psize, !=, 0); 4210 4211 enc_buf = zio_buf_alloc(psize); 4212 eabd = abd_get_from_buf(enc_buf, psize); 4213 abd_take_ownership_of_buf(eabd, B_TRUE); 4214 4215 /* 4216 * For an explanation of what encryption parameters are stored 4217 * where, see the block comment in zio_crypt.c. 4218 */ 4219 if (ot == DMU_OT_INTENT_LOG) { 4220 zio_crypt_decode_params_bp(bp, salt, iv); 4221 } else { 4222 BP_SET_CRYPT(bp, B_TRUE); 4223 } 4224 4225 /* Perform the encryption. This should not fail */ 4226 VERIFY0(spa_do_crypt_abd(B_TRUE, spa, &zio->io_bookmark, 4227 BP_GET_TYPE(bp), BP_GET_DEDUP(bp), BP_SHOULD_BYTESWAP(bp), 4228 salt, iv, mac, psize, zio->io_abd, eabd, &no_crypt)); 4229 4230 /* encode encryption metadata into the bp */ 4231 if (ot == DMU_OT_INTENT_LOG) { 4232 /* 4233 * ZIL blocks store the MAC in the embedded checksum, so the 4234 * transform must always be applied. 4235 */ 4236 zio_crypt_encode_mac_zil(enc_buf, mac); 4237 zio_push_transform(zio, eabd, psize, psize, NULL); 4238 } else { 4239 BP_SET_CRYPT(bp, B_TRUE); 4240 zio_crypt_encode_params_bp(bp, salt, iv); 4241 zio_crypt_encode_mac_bp(bp, mac); 4242 4243 if (no_crypt) { 4244 ASSERT3U(ot, ==, DMU_OT_DNODE); 4245 abd_free(eabd); 4246 } else { 4247 zio_push_transform(zio, eabd, psize, psize, NULL); 4248 } 4249 } 4250 4251 return (zio); 4252 } 4253 4254 /* 4255 * ========================================================================== 4256 * Generate and verify checksums 4257 * ========================================================================== 4258 */ 4259 static zio_t * 4260 zio_checksum_generate(zio_t *zio) 4261 { 4262 blkptr_t *bp = zio->io_bp; 4263 enum zio_checksum checksum; 4264 4265 if (bp == NULL) { 4266 /* 4267 * This is zio_write_phys(). 4268 * We're either generating a label checksum, or none at all. 4269 */ 4270 checksum = zio->io_prop.zp_checksum; 4271 4272 if (checksum == ZIO_CHECKSUM_OFF) 4273 return (zio); 4274 4275 ASSERT(checksum == ZIO_CHECKSUM_LABEL); 4276 } else { 4277 if (BP_IS_GANG(bp) && zio->io_child_type == ZIO_CHILD_GANG) { 4278 ASSERT(!IO_IS_ALLOCATING(zio)); 4279 checksum = ZIO_CHECKSUM_GANG_HEADER; 4280 } else { 4281 checksum = BP_GET_CHECKSUM(bp); 4282 } 4283 } 4284 4285 zio_checksum_compute(zio, checksum, zio->io_abd, zio->io_size); 4286 4287 return (zio); 4288 } 4289 4290 static zio_t * 4291 zio_checksum_verify(zio_t *zio) 4292 { 4293 zio_bad_cksum_t info; 4294 blkptr_t *bp = zio->io_bp; 4295 int error; 4296 4297 ASSERT(zio->io_vd != NULL); 4298 4299 if (bp == NULL) { 4300 /* 4301 * This is zio_read_phys(). 4302 * We're either verifying a label checksum, or nothing at all. 4303 */ 4304 if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF) 4305 return (zio); 4306 4307 ASSERT3U(zio->io_prop.zp_checksum, ==, ZIO_CHECKSUM_LABEL); 4308 } 4309 4310 if ((error = zio_checksum_error(zio, &info)) != 0) { 4311 zio->io_error = error; 4312 if (error == ECKSUM && 4313 !(zio->io_flags & ZIO_FLAG_SPECULATIVE)) { 4314 (void) zfs_ereport_start_checksum(zio->io_spa, 4315 zio->io_vd, &zio->io_bookmark, zio, 4316 zio->io_offset, zio->io_size, &info); 4317 mutex_enter(&zio->io_vd->vdev_stat_lock); 4318 zio->io_vd->vdev_stat.vs_checksum_errors++; 4319 mutex_exit(&zio->io_vd->vdev_stat_lock); 4320 } 4321 } 4322 4323 return (zio); 4324 } 4325 4326 /* 4327 * Called by RAID-Z to ensure we don't compute the checksum twice. 4328 */ 4329 void 4330 zio_checksum_verified(zio_t *zio) 4331 { 4332 zio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 4333 } 4334 4335 /* 4336 * ========================================================================== 4337 * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other. 4338 * An error of 0 indicates success. ENXIO indicates whole-device failure, 4339 * which may be transient (e.g. unplugged) or permanent. ECKSUM and EIO 4340 * indicate errors that are specific to one I/O, and most likely permanent. 4341 * Any other error is presumed to be worse because we weren't expecting it. 4342 * ========================================================================== 4343 */ 4344 int 4345 zio_worst_error(int e1, int e2) 4346 { 4347 static int zio_error_rank[] = { 0, ENXIO, ECKSUM, EIO }; 4348 int r1, r2; 4349 4350 for (r1 = 0; r1 < sizeof (zio_error_rank) / sizeof (int); r1++) 4351 if (e1 == zio_error_rank[r1]) 4352 break; 4353 4354 for (r2 = 0; r2 < sizeof (zio_error_rank) / sizeof (int); r2++) 4355 if (e2 == zio_error_rank[r2]) 4356 break; 4357 4358 return (r1 > r2 ? e1 : e2); 4359 } 4360 4361 /* 4362 * ========================================================================== 4363 * I/O completion 4364 * ========================================================================== 4365 */ 4366 static zio_t * 4367 zio_ready(zio_t *zio) 4368 { 4369 blkptr_t *bp = zio->io_bp; 4370 zio_t *pio, *pio_next; 4371 zio_link_t *zl = NULL; 4372 4373 if (zio_wait_for_children(zio, ZIO_CHILD_GANG_BIT | ZIO_CHILD_DDT_BIT, 4374 ZIO_WAIT_READY)) { 4375 return (NULL); 4376 } 4377 4378 if (zio->io_ready) { 4379 ASSERT(IO_IS_ALLOCATING(zio)); 4380 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp) || 4381 (zio->io_flags & ZIO_FLAG_NOPWRITE)); 4382 ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0); 4383 4384 zio->io_ready(zio); 4385 } 4386 4387 if (bp != NULL && bp != &zio->io_bp_copy) 4388 zio->io_bp_copy = *bp; 4389 4390 if (zio->io_error != 0) { 4391 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 4392 4393 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 4394 ASSERT(IO_IS_ALLOCATING(zio)); 4395 ASSERT(zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 4396 ASSERT(zio->io_metaslab_class != NULL); 4397 4398 /* 4399 * We were unable to allocate anything, unreserve and 4400 * issue the next I/O to allocate. 4401 */ 4402 metaslab_class_throttle_unreserve( 4403 zio->io_metaslab_class, zio->io_prop.zp_copies, 4404 zio->io_allocator, zio); 4405 zio_allocate_dispatch(zio->io_spa, zio->io_allocator); 4406 } 4407 } 4408 4409 mutex_enter(&zio->io_lock); 4410 zio->io_state[ZIO_WAIT_READY] = 1; 4411 pio = zio_walk_parents(zio, &zl); 4412 mutex_exit(&zio->io_lock); 4413 4414 /* 4415 * As we notify zio's parents, new parents could be added. 4416 * New parents go to the head of zio's io_parent_list, however, 4417 * so we will (correctly) not notify them. The remainder of zio's 4418 * io_parent_list, from 'pio_next' onward, cannot change because 4419 * all parents must wait for us to be done before they can be done. 4420 */ 4421 for (; pio != NULL; pio = pio_next) { 4422 pio_next = zio_walk_parents(zio, &zl); 4423 zio_notify_parent(pio, zio, ZIO_WAIT_READY, NULL); 4424 } 4425 4426 if (zio->io_flags & ZIO_FLAG_NODATA) { 4427 if (BP_IS_GANG(bp)) { 4428 zio->io_flags &= ~ZIO_FLAG_NODATA; 4429 } else { 4430 ASSERT((uintptr_t)zio->io_abd < SPA_MAXBLOCKSIZE); 4431 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 4432 } 4433 } 4434 4435 if (zio_injection_enabled && 4436 zio->io_spa->spa_syncing_txg == zio->io_txg) 4437 zio_handle_ignored_writes(zio); 4438 4439 return (zio); 4440 } 4441 4442 /* 4443 * Update the allocation throttle accounting. 4444 */ 4445 static void 4446 zio_dva_throttle_done(zio_t *zio) 4447 { 4448 zio_t *lio __maybe_unused = zio->io_logical; 4449 zio_t *pio = zio_unique_parent(zio); 4450 vdev_t *vd = zio->io_vd; 4451 int flags = METASLAB_ASYNC_ALLOC; 4452 4453 ASSERT3P(zio->io_bp, !=, NULL); 4454 ASSERT3U(zio->io_type, ==, ZIO_TYPE_WRITE); 4455 ASSERT3U(zio->io_priority, ==, ZIO_PRIORITY_ASYNC_WRITE); 4456 ASSERT3U(zio->io_child_type, ==, ZIO_CHILD_VDEV); 4457 ASSERT(vd != NULL); 4458 ASSERT3P(vd, ==, vd->vdev_top); 4459 ASSERT(zio_injection_enabled || !(zio->io_flags & ZIO_FLAG_IO_RETRY)); 4460 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REPAIR)); 4461 ASSERT(zio->io_flags & ZIO_FLAG_IO_ALLOCATING); 4462 ASSERT(!(lio->io_flags & ZIO_FLAG_IO_REWRITE)); 4463 ASSERT(!(lio->io_orig_flags & ZIO_FLAG_NODATA)); 4464 4465 /* 4466 * Parents of gang children can have two flavors -- ones that 4467 * allocated the gang header (will have ZIO_FLAG_IO_REWRITE set) 4468 * and ones that allocated the constituent blocks. The allocation 4469 * throttle needs to know the allocating parent zio so we must find 4470 * it here. 4471 */ 4472 if (pio->io_child_type == ZIO_CHILD_GANG) { 4473 /* 4474 * If our parent is a rewrite gang child then our grandparent 4475 * would have been the one that performed the allocation. 4476 */ 4477 if (pio->io_flags & ZIO_FLAG_IO_REWRITE) 4478 pio = zio_unique_parent(pio); 4479 flags |= METASLAB_GANG_CHILD; 4480 } 4481 4482 ASSERT(IO_IS_ALLOCATING(pio)); 4483 ASSERT3P(zio, !=, zio->io_logical); 4484 ASSERT(zio->io_logical != NULL); 4485 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REPAIR)); 4486 ASSERT0(zio->io_flags & ZIO_FLAG_NOPWRITE); 4487 ASSERT(zio->io_metaslab_class != NULL); 4488 4489 mutex_enter(&pio->io_lock); 4490 metaslab_group_alloc_decrement(zio->io_spa, vd->vdev_id, pio, flags, 4491 pio->io_allocator, B_TRUE); 4492 mutex_exit(&pio->io_lock); 4493 4494 metaslab_class_throttle_unreserve(zio->io_metaslab_class, 1, 4495 pio->io_allocator, pio); 4496 4497 /* 4498 * Call into the pipeline to see if there is more work that 4499 * needs to be done. If there is work to be done it will be 4500 * dispatched to another taskq thread. 4501 */ 4502 zio_allocate_dispatch(zio->io_spa, pio->io_allocator); 4503 } 4504 4505 static zio_t * 4506 zio_done(zio_t *zio) 4507 { 4508 /* 4509 * Always attempt to keep stack usage minimal here since 4510 * we can be called recursively up to 19 levels deep. 4511 */ 4512 const uint64_t psize = zio->io_size; 4513 zio_t *pio, *pio_next; 4514 zio_link_t *zl = NULL; 4515 4516 /* 4517 * If our children haven't all completed, 4518 * wait for them and then repeat this pipeline stage. 4519 */ 4520 if (zio_wait_for_children(zio, ZIO_CHILD_ALL_BITS, ZIO_WAIT_DONE)) { 4521 return (NULL); 4522 } 4523 4524 /* 4525 * If the allocation throttle is enabled, then update the accounting. 4526 * We only track child I/Os that are part of an allocating async 4527 * write. We must do this since the allocation is performed 4528 * by the logical I/O but the actual write is done by child I/Os. 4529 */ 4530 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING && 4531 zio->io_child_type == ZIO_CHILD_VDEV) { 4532 ASSERT(zio->io_metaslab_class != NULL); 4533 ASSERT(zio->io_metaslab_class->mc_alloc_throttle_enabled); 4534 zio_dva_throttle_done(zio); 4535 } 4536 4537 /* 4538 * If the allocation throttle is enabled, verify that 4539 * we have decremented the refcounts for every I/O that was throttled. 4540 */ 4541 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 4542 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 4543 ASSERT(zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 4544 ASSERT(zio->io_bp != NULL); 4545 4546 metaslab_group_alloc_verify(zio->io_spa, zio->io_bp, zio, 4547 zio->io_allocator); 4548 VERIFY(zfs_refcount_not_held(&zio->io_metaslab_class-> 4549 mc_allocator[zio->io_allocator].mca_alloc_slots, zio)); 4550 } 4551 4552 4553 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 4554 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 4555 ASSERT(zio->io_children[c][w] == 0); 4556 4557 if (zio->io_bp != NULL && !BP_IS_EMBEDDED(zio->io_bp)) { 4558 ASSERT(zio->io_bp->blk_pad[0] == 0); 4559 ASSERT(zio->io_bp->blk_pad[1] == 0); 4560 ASSERT(memcmp(zio->io_bp, &zio->io_bp_copy, 4561 sizeof (blkptr_t)) == 0 || 4562 (zio->io_bp == zio_unique_parent(zio)->io_bp)); 4563 if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(zio->io_bp) && 4564 zio->io_bp_override == NULL && 4565 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) { 4566 ASSERT3U(zio->io_prop.zp_copies, <=, 4567 BP_GET_NDVAS(zio->io_bp)); 4568 ASSERT(BP_COUNT_GANG(zio->io_bp) == 0 || 4569 (BP_COUNT_GANG(zio->io_bp) == 4570 BP_GET_NDVAS(zio->io_bp))); 4571 } 4572 if (zio->io_flags & ZIO_FLAG_NOPWRITE) 4573 VERIFY(BP_EQUAL(zio->io_bp, &zio->io_bp_orig)); 4574 } 4575 4576 /* 4577 * If there were child vdev/gang/ddt errors, they apply to us now. 4578 */ 4579 zio_inherit_child_errors(zio, ZIO_CHILD_VDEV); 4580 zio_inherit_child_errors(zio, ZIO_CHILD_GANG); 4581 zio_inherit_child_errors(zio, ZIO_CHILD_DDT); 4582 4583 /* 4584 * If the I/O on the transformed data was successful, generate any 4585 * checksum reports now while we still have the transformed data. 4586 */ 4587 if (zio->io_error == 0) { 4588 while (zio->io_cksum_report != NULL) { 4589 zio_cksum_report_t *zcr = zio->io_cksum_report; 4590 uint64_t align = zcr->zcr_align; 4591 uint64_t asize = P2ROUNDUP(psize, align); 4592 abd_t *adata = zio->io_abd; 4593 4594 if (adata != NULL && asize != psize) { 4595 adata = abd_alloc(asize, B_TRUE); 4596 abd_copy(adata, zio->io_abd, psize); 4597 abd_zero_off(adata, psize, asize - psize); 4598 } 4599 4600 zio->io_cksum_report = zcr->zcr_next; 4601 zcr->zcr_next = NULL; 4602 zcr->zcr_finish(zcr, adata); 4603 zfs_ereport_free_checksum(zcr); 4604 4605 if (adata != NULL && asize != psize) 4606 abd_free(adata); 4607 } 4608 } 4609 4610 zio_pop_transforms(zio); /* note: may set zio->io_error */ 4611 4612 vdev_stat_update(zio, psize); 4613 4614 /* 4615 * If this I/O is attached to a particular vdev is slow, exceeding 4616 * 30 seconds to complete, post an error described the I/O delay. 4617 * We ignore these errors if the device is currently unavailable. 4618 */ 4619 if (zio->io_delay >= MSEC2NSEC(zio_slow_io_ms)) { 4620 if (zio->io_vd != NULL && !vdev_is_dead(zio->io_vd)) { 4621 /* 4622 * We want to only increment our slow IO counters if 4623 * the IO is valid (i.e. not if the drive is removed). 4624 * 4625 * zfs_ereport_post() will also do these checks, but 4626 * it can also ratelimit and have other failures, so we 4627 * need to increment the slow_io counters independent 4628 * of it. 4629 */ 4630 if (zfs_ereport_is_valid(FM_EREPORT_ZFS_DELAY, 4631 zio->io_spa, zio->io_vd, zio)) { 4632 mutex_enter(&zio->io_vd->vdev_stat_lock); 4633 zio->io_vd->vdev_stat.vs_slow_ios++; 4634 mutex_exit(&zio->io_vd->vdev_stat_lock); 4635 4636 (void) zfs_ereport_post(FM_EREPORT_ZFS_DELAY, 4637 zio->io_spa, zio->io_vd, &zio->io_bookmark, 4638 zio, 0); 4639 } 4640 } 4641 } 4642 4643 if (zio->io_error) { 4644 /* 4645 * If this I/O is attached to a particular vdev, 4646 * generate an error message describing the I/O failure 4647 * at the block level. We ignore these errors if the 4648 * device is currently unavailable. 4649 */ 4650 if (zio->io_error != ECKSUM && zio->io_vd != NULL && 4651 !vdev_is_dead(zio->io_vd)) { 4652 int ret = zfs_ereport_post(FM_EREPORT_ZFS_IO, 4653 zio->io_spa, zio->io_vd, &zio->io_bookmark, zio, 0); 4654 if (ret != EALREADY) { 4655 mutex_enter(&zio->io_vd->vdev_stat_lock); 4656 if (zio->io_type == ZIO_TYPE_READ) 4657 zio->io_vd->vdev_stat.vs_read_errors++; 4658 else if (zio->io_type == ZIO_TYPE_WRITE) 4659 zio->io_vd->vdev_stat.vs_write_errors++; 4660 mutex_exit(&zio->io_vd->vdev_stat_lock); 4661 } 4662 } 4663 4664 if ((zio->io_error == EIO || !(zio->io_flags & 4665 (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) && 4666 zio == zio->io_logical) { 4667 /* 4668 * For logical I/O requests, tell the SPA to log the 4669 * error and generate a logical data ereport. 4670 */ 4671 spa_log_error(zio->io_spa, &zio->io_bookmark); 4672 (void) zfs_ereport_post(FM_EREPORT_ZFS_DATA, 4673 zio->io_spa, NULL, &zio->io_bookmark, zio, 0); 4674 } 4675 } 4676 4677 if (zio->io_error && zio == zio->io_logical) { 4678 /* 4679 * Determine whether zio should be reexecuted. This will 4680 * propagate all the way to the root via zio_notify_parent(). 4681 */ 4682 ASSERT(zio->io_vd == NULL && zio->io_bp != NULL); 4683 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 4684 4685 if (IO_IS_ALLOCATING(zio) && 4686 !(zio->io_flags & ZIO_FLAG_CANFAIL)) { 4687 if (zio->io_error != ENOSPC) 4688 zio->io_reexecute |= ZIO_REEXECUTE_NOW; 4689 else 4690 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 4691 } 4692 4693 if ((zio->io_type == ZIO_TYPE_READ || 4694 zio->io_type == ZIO_TYPE_FREE) && 4695 !(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && 4696 zio->io_error == ENXIO && 4697 spa_load_state(zio->io_spa) == SPA_LOAD_NONE && 4698 spa_get_failmode(zio->io_spa) != ZIO_FAILURE_MODE_CONTINUE) 4699 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 4700 4701 if (!(zio->io_flags & ZIO_FLAG_CANFAIL) && !zio->io_reexecute) 4702 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 4703 4704 /* 4705 * Here is a possibly good place to attempt to do 4706 * either combinatorial reconstruction or error correction 4707 * based on checksums. It also might be a good place 4708 * to send out preliminary ereports before we suspend 4709 * processing. 4710 */ 4711 } 4712 4713 /* 4714 * If there were logical child errors, they apply to us now. 4715 * We defer this until now to avoid conflating logical child 4716 * errors with errors that happened to the zio itself when 4717 * updating vdev stats and reporting FMA events above. 4718 */ 4719 zio_inherit_child_errors(zio, ZIO_CHILD_LOGICAL); 4720 4721 if ((zio->io_error || zio->io_reexecute) && 4722 IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio && 4723 !(zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE))) 4724 zio_dva_unallocate(zio, zio->io_gang_tree, zio->io_bp); 4725 4726 zio_gang_tree_free(&zio->io_gang_tree); 4727 4728 /* 4729 * Godfather I/Os should never suspend. 4730 */ 4731 if ((zio->io_flags & ZIO_FLAG_GODFATHER) && 4732 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) 4733 zio->io_reexecute &= ~ZIO_REEXECUTE_SUSPEND; 4734 4735 if (zio->io_reexecute) { 4736 /* 4737 * This is a logical I/O that wants to reexecute. 4738 * 4739 * Reexecute is top-down. When an i/o fails, if it's not 4740 * the root, it simply notifies its parent and sticks around. 4741 * The parent, seeing that it still has children in zio_done(), 4742 * does the same. This percolates all the way up to the root. 4743 * The root i/o will reexecute or suspend the entire tree. 4744 * 4745 * This approach ensures that zio_reexecute() honors 4746 * all the original i/o dependency relationships, e.g. 4747 * parents not executing until children are ready. 4748 */ 4749 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 4750 4751 zio->io_gang_leader = NULL; 4752 4753 mutex_enter(&zio->io_lock); 4754 zio->io_state[ZIO_WAIT_DONE] = 1; 4755 mutex_exit(&zio->io_lock); 4756 4757 /* 4758 * "The Godfather" I/O monitors its children but is 4759 * not a true parent to them. It will track them through 4760 * the pipeline but severs its ties whenever they get into 4761 * trouble (e.g. suspended). This allows "The Godfather" 4762 * I/O to return status without blocking. 4763 */ 4764 zl = NULL; 4765 for (pio = zio_walk_parents(zio, &zl); pio != NULL; 4766 pio = pio_next) { 4767 zio_link_t *remove_zl = zl; 4768 pio_next = zio_walk_parents(zio, &zl); 4769 4770 if ((pio->io_flags & ZIO_FLAG_GODFATHER) && 4771 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) { 4772 zio_remove_child(pio, zio, remove_zl); 4773 /* 4774 * This is a rare code path, so we don't 4775 * bother with "next_to_execute". 4776 */ 4777 zio_notify_parent(pio, zio, ZIO_WAIT_DONE, 4778 NULL); 4779 } 4780 } 4781 4782 if ((pio = zio_unique_parent(zio)) != NULL) { 4783 /* 4784 * We're not a root i/o, so there's nothing to do 4785 * but notify our parent. Don't propagate errors 4786 * upward since we haven't permanently failed yet. 4787 */ 4788 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 4789 zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE; 4790 /* 4791 * This is a rare code path, so we don't bother with 4792 * "next_to_execute". 4793 */ 4794 zio_notify_parent(pio, zio, ZIO_WAIT_DONE, NULL); 4795 } else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) { 4796 /* 4797 * We'd fail again if we reexecuted now, so suspend 4798 * until conditions improve (e.g. device comes online). 4799 */ 4800 zio_suspend(zio->io_spa, zio, ZIO_SUSPEND_IOERR); 4801 } else { 4802 /* 4803 * Reexecution is potentially a huge amount of work. 4804 * Hand it off to the otherwise-unused claim taskq. 4805 */ 4806 ASSERT(taskq_empty_ent(&zio->io_tqent)); 4807 spa_taskq_dispatch_ent(zio->io_spa, 4808 ZIO_TYPE_CLAIM, ZIO_TASKQ_ISSUE, 4809 zio_reexecute, zio, 0, &zio->io_tqent); 4810 } 4811 return (NULL); 4812 } 4813 4814 ASSERT(zio->io_child_count == 0); 4815 ASSERT(zio->io_reexecute == 0); 4816 ASSERT(zio->io_error == 0 || (zio->io_flags & ZIO_FLAG_CANFAIL)); 4817 4818 /* 4819 * Report any checksum errors, since the I/O is complete. 4820 */ 4821 while (zio->io_cksum_report != NULL) { 4822 zio_cksum_report_t *zcr = zio->io_cksum_report; 4823 zio->io_cksum_report = zcr->zcr_next; 4824 zcr->zcr_next = NULL; 4825 zcr->zcr_finish(zcr, NULL); 4826 zfs_ereport_free_checksum(zcr); 4827 } 4828 4829 if (zio->io_flags & ZIO_FLAG_FASTWRITE && zio->io_bp && 4830 !BP_IS_HOLE(zio->io_bp) && !BP_IS_EMBEDDED(zio->io_bp) && 4831 !(zio->io_flags & ZIO_FLAG_NOPWRITE)) { 4832 metaslab_fastwrite_unmark(zio->io_spa, zio->io_bp); 4833 } 4834 4835 /* 4836 * It is the responsibility of the done callback to ensure that this 4837 * particular zio is no longer discoverable for adoption, and as 4838 * such, cannot acquire any new parents. 4839 */ 4840 if (zio->io_done) 4841 zio->io_done(zio); 4842 4843 mutex_enter(&zio->io_lock); 4844 zio->io_state[ZIO_WAIT_DONE] = 1; 4845 mutex_exit(&zio->io_lock); 4846 4847 /* 4848 * We are done executing this zio. We may want to execute a parent 4849 * next. See the comment in zio_notify_parent(). 4850 */ 4851 zio_t *next_to_execute = NULL; 4852 zl = NULL; 4853 for (pio = zio_walk_parents(zio, &zl); pio != NULL; pio = pio_next) { 4854 zio_link_t *remove_zl = zl; 4855 pio_next = zio_walk_parents(zio, &zl); 4856 zio_remove_child(pio, zio, remove_zl); 4857 zio_notify_parent(pio, zio, ZIO_WAIT_DONE, &next_to_execute); 4858 } 4859 4860 if (zio->io_waiter != NULL) { 4861 mutex_enter(&zio->io_lock); 4862 zio->io_executor = NULL; 4863 cv_broadcast(&zio->io_cv); 4864 mutex_exit(&zio->io_lock); 4865 } else { 4866 zio_destroy(zio); 4867 } 4868 4869 return (next_to_execute); 4870 } 4871 4872 /* 4873 * ========================================================================== 4874 * I/O pipeline definition 4875 * ========================================================================== 4876 */ 4877 static zio_pipe_stage_t *zio_pipeline[] = { 4878 NULL, 4879 zio_read_bp_init, 4880 zio_write_bp_init, 4881 zio_free_bp_init, 4882 zio_issue_async, 4883 zio_write_compress, 4884 zio_encrypt, 4885 zio_checksum_generate, 4886 zio_nop_write, 4887 zio_ddt_read_start, 4888 zio_ddt_read_done, 4889 zio_ddt_write, 4890 zio_ddt_free, 4891 zio_gang_assemble, 4892 zio_gang_issue, 4893 zio_dva_throttle, 4894 zio_dva_allocate, 4895 zio_dva_free, 4896 zio_dva_claim, 4897 zio_ready, 4898 zio_vdev_io_start, 4899 zio_vdev_io_done, 4900 zio_vdev_io_assess, 4901 zio_checksum_verify, 4902 zio_done 4903 }; 4904 4905 4906 4907 4908 /* 4909 * Compare two zbookmark_phys_t's to see which we would reach first in a 4910 * pre-order traversal of the object tree. 4911 * 4912 * This is simple in every case aside from the meta-dnode object. For all other 4913 * objects, we traverse them in order (object 1 before object 2, and so on). 4914 * However, all of these objects are traversed while traversing object 0, since 4915 * the data it points to is the list of objects. Thus, we need to convert to a 4916 * canonical representation so we can compare meta-dnode bookmarks to 4917 * non-meta-dnode bookmarks. 4918 * 4919 * We do this by calculating "equivalents" for each field of the zbookmark. 4920 * zbookmarks outside of the meta-dnode use their own object and level, and 4921 * calculate the level 0 equivalent (the first L0 blkid that is contained in the 4922 * blocks this bookmark refers to) by multiplying their blkid by their span 4923 * (the number of L0 blocks contained within one block at their level). 4924 * zbookmarks inside the meta-dnode calculate their object equivalent 4925 * (which is L0equiv * dnodes per data block), use 0 for their L0equiv, and use 4926 * level + 1<<31 (any value larger than a level could ever be) for their level. 4927 * This causes them to always compare before a bookmark in their object 4928 * equivalent, compare appropriately to bookmarks in other objects, and to 4929 * compare appropriately to other bookmarks in the meta-dnode. 4930 */ 4931 int 4932 zbookmark_compare(uint16_t dbss1, uint8_t ibs1, uint16_t dbss2, uint8_t ibs2, 4933 const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2) 4934 { 4935 /* 4936 * These variables represent the "equivalent" values for the zbookmark, 4937 * after converting zbookmarks inside the meta dnode to their 4938 * normal-object equivalents. 4939 */ 4940 uint64_t zb1obj, zb2obj; 4941 uint64_t zb1L0, zb2L0; 4942 uint64_t zb1level, zb2level; 4943 4944 if (zb1->zb_object == zb2->zb_object && 4945 zb1->zb_level == zb2->zb_level && 4946 zb1->zb_blkid == zb2->zb_blkid) 4947 return (0); 4948 4949 IMPLY(zb1->zb_level > 0, ibs1 >= SPA_MINBLOCKSHIFT); 4950 IMPLY(zb2->zb_level > 0, ibs2 >= SPA_MINBLOCKSHIFT); 4951 4952 /* 4953 * BP_SPANB calculates the span in blocks. 4954 */ 4955 zb1L0 = (zb1->zb_blkid) * BP_SPANB(ibs1, zb1->zb_level); 4956 zb2L0 = (zb2->zb_blkid) * BP_SPANB(ibs2, zb2->zb_level); 4957 4958 if (zb1->zb_object == DMU_META_DNODE_OBJECT) { 4959 zb1obj = zb1L0 * (dbss1 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT)); 4960 zb1L0 = 0; 4961 zb1level = zb1->zb_level + COMPARE_META_LEVEL; 4962 } else { 4963 zb1obj = zb1->zb_object; 4964 zb1level = zb1->zb_level; 4965 } 4966 4967 if (zb2->zb_object == DMU_META_DNODE_OBJECT) { 4968 zb2obj = zb2L0 * (dbss2 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT)); 4969 zb2L0 = 0; 4970 zb2level = zb2->zb_level + COMPARE_META_LEVEL; 4971 } else { 4972 zb2obj = zb2->zb_object; 4973 zb2level = zb2->zb_level; 4974 } 4975 4976 /* Now that we have a canonical representation, do the comparison. */ 4977 if (zb1obj != zb2obj) 4978 return (zb1obj < zb2obj ? -1 : 1); 4979 else if (zb1L0 != zb2L0) 4980 return (zb1L0 < zb2L0 ? -1 : 1); 4981 else if (zb1level != zb2level) 4982 return (zb1level > zb2level ? -1 : 1); 4983 /* 4984 * This can (theoretically) happen if the bookmarks have the same object 4985 * and level, but different blkids, if the block sizes are not the same. 4986 * There is presently no way to change the indirect block sizes 4987 */ 4988 return (0); 4989 } 4990 4991 /* 4992 * This function checks the following: given that last_block is the place that 4993 * our traversal stopped last time, does that guarantee that we've visited 4994 * every node under subtree_root? Therefore, we can't just use the raw output 4995 * of zbookmark_compare. We have to pass in a modified version of 4996 * subtree_root; by incrementing the block id, and then checking whether 4997 * last_block is before or equal to that, we can tell whether or not having 4998 * visited last_block implies that all of subtree_root's children have been 4999 * visited. 5000 */ 5001 boolean_t 5002 zbookmark_subtree_completed(const dnode_phys_t *dnp, 5003 const zbookmark_phys_t *subtree_root, const zbookmark_phys_t *last_block) 5004 { 5005 zbookmark_phys_t mod_zb = *subtree_root; 5006 mod_zb.zb_blkid++; 5007 ASSERT0(last_block->zb_level); 5008 5009 /* The objset_phys_t isn't before anything. */ 5010 if (dnp == NULL) 5011 return (B_FALSE); 5012 5013 /* 5014 * We pass in 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT) for the 5015 * data block size in sectors, because that variable is only used if 5016 * the bookmark refers to a block in the meta-dnode. Since we don't 5017 * know without examining it what object it refers to, and there's no 5018 * harm in passing in this value in other cases, we always pass it in. 5019 * 5020 * We pass in 0 for the indirect block size shift because zb2 must be 5021 * level 0. The indirect block size is only used to calculate the span 5022 * of the bookmark, but since the bookmark must be level 0, the span is 5023 * always 1, so the math works out. 5024 * 5025 * If you make changes to how the zbookmark_compare code works, be sure 5026 * to make sure that this code still works afterwards. 5027 */ 5028 return (zbookmark_compare(dnp->dn_datablkszsec, dnp->dn_indblkshift, 5029 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT), 0, &mod_zb, 5030 last_block) <= 0); 5031 } 5032 5033 /* 5034 * This function is similar to zbookmark_subtree_completed(), but returns true 5035 * if subtree_root is equal or ahead of last_block, i.e. still to be done. 5036 */ 5037 boolean_t 5038 zbookmark_subtree_tbd(const dnode_phys_t *dnp, 5039 const zbookmark_phys_t *subtree_root, const zbookmark_phys_t *last_block) 5040 { 5041 ASSERT0(last_block->zb_level); 5042 if (dnp == NULL) 5043 return (B_FALSE); 5044 return (zbookmark_compare(dnp->dn_datablkszsec, dnp->dn_indblkshift, 5045 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT), 0, subtree_root, 5046 last_block) >= 0); 5047 } 5048 5049 EXPORT_SYMBOL(zio_type_name); 5050 EXPORT_SYMBOL(zio_buf_alloc); 5051 EXPORT_SYMBOL(zio_data_buf_alloc); 5052 EXPORT_SYMBOL(zio_buf_free); 5053 EXPORT_SYMBOL(zio_data_buf_free); 5054 5055 ZFS_MODULE_PARAM(zfs_zio, zio_, slow_io_ms, INT, ZMOD_RW, 5056 "Max I/O completion time (milliseconds) before marking it as slow"); 5057 5058 ZFS_MODULE_PARAM(zfs_zio, zio_, requeue_io_start_cut_in_line, INT, ZMOD_RW, 5059 "Prioritize requeued I/O"); 5060 5061 ZFS_MODULE_PARAM(zfs, zfs_, sync_pass_deferred_free, UINT, ZMOD_RW, 5062 "Defer frees starting in this pass"); 5063 5064 ZFS_MODULE_PARAM(zfs, zfs_, sync_pass_dont_compress, UINT, ZMOD_RW, 5065 "Don't compress starting in this pass"); 5066 5067 ZFS_MODULE_PARAM(zfs, zfs_, sync_pass_rewrite, UINT, ZMOD_RW, 5068 "Rewrite new bps starting in this pass"); 5069 5070 ZFS_MODULE_PARAM(zfs_zio, zio_, dva_throttle_enabled, INT, ZMOD_RW, 5071 "Throttle block allocations in the ZIO pipeline"); 5072 5073 ZFS_MODULE_PARAM(zfs_zio, zio_, deadman_log_all, INT, ZMOD_RW, 5074 "Log all slow ZIOs, not just those with vdevs"); 5075