1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. 23 * Copyright (c) 2011, 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 int 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 int zfs_sync_pass_deferred_free = 2; /* defer frees starting in this pass */ 118 static int zfs_sync_pass_dont_compress = 8; /* don't compress s. i. t. p. */ 119 static int zfs_sync_pass_rewrite = 2; /* rewrite new bps s. i. t. p. */ 120 121 /* 122 * An allocating zio is one that either currently has the DVA allocate 123 * stage set or will have it later in its lifetime. 124 */ 125 #define IO_IS_ALLOCATING(zio) ((zio)->io_orig_pipeline & ZIO_STAGE_DVA_ALLOCATE) 126 127 /* 128 * Enable smaller cores by excluding metadata 129 * allocations as well. 130 */ 131 int zio_exclude_metadata = 0; 132 static int zio_requeue_io_start_cut_in_line = 1; 133 134 #ifdef ZFS_DEBUG 135 static const int zio_buf_debug_limit = 16384; 136 #else 137 static const int zio_buf_debug_limit = 0; 138 #endif 139 140 static inline void __zio_execute(zio_t *zio); 141 142 static void zio_taskq_dispatch(zio_t *, zio_taskq_type_t, boolean_t); 143 144 void 145 zio_init(void) 146 { 147 size_t c; 148 149 zio_cache = kmem_cache_create("zio_cache", 150 sizeof (zio_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 151 zio_link_cache = kmem_cache_create("zio_link_cache", 152 sizeof (zio_link_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 153 154 /* 155 * For small buffers, we want a cache for each multiple of 156 * SPA_MINBLOCKSIZE. For larger buffers, we want a cache 157 * for each quarter-power of 2. 158 */ 159 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) { 160 size_t size = (c + 1) << SPA_MINBLOCKSHIFT; 161 size_t p2 = size; 162 size_t align = 0; 163 size_t data_cflags, cflags; 164 165 data_cflags = KMC_NODEBUG; 166 cflags = (zio_exclude_metadata || size > zio_buf_debug_limit) ? 167 KMC_NODEBUG : 0; 168 169 #if defined(_ILP32) && defined(_KERNEL) 170 /* 171 * Cache size limited to 1M on 32-bit platforms until ARC 172 * buffers no longer require virtual address space. 173 */ 174 if (size > zfs_max_recordsize) 175 break; 176 #endif 177 178 while (!ISP2(p2)) 179 p2 &= p2 - 1; 180 181 #ifndef _KERNEL 182 /* 183 * If we are using watchpoints, put each buffer on its own page, 184 * to eliminate the performance overhead of trapping to the 185 * kernel when modifying a non-watched buffer that shares the 186 * page with a watched buffer. 187 */ 188 if (arc_watch && !IS_P2ALIGNED(size, PAGESIZE)) 189 continue; 190 /* 191 * Here's the problem - on 4K native devices in userland on 192 * Linux using O_DIRECT, buffers must be 4K aligned or I/O 193 * will fail with EINVAL, causing zdb (and others) to coredump. 194 * Since userland probably doesn't need optimized buffer caches, 195 * we just force 4K alignment on everything. 196 */ 197 align = 8 * SPA_MINBLOCKSIZE; 198 #else 199 if (size < PAGESIZE) { 200 align = SPA_MINBLOCKSIZE; 201 } else if (IS_P2ALIGNED(size, p2 >> 2)) { 202 align = PAGESIZE; 203 } 204 #endif 205 206 if (align != 0) { 207 char name[36]; 208 if (cflags == data_cflags) { 209 /* 210 * Resulting kmem caches would be identical. 211 * Save memory by creating only one. 212 */ 213 (void) snprintf(name, sizeof (name), 214 "zio_buf_comb_%lu", (ulong_t)size); 215 zio_buf_cache[c] = kmem_cache_create(name, 216 size, align, NULL, NULL, NULL, NULL, NULL, 217 cflags); 218 zio_data_buf_cache[c] = zio_buf_cache[c]; 219 continue; 220 } 221 (void) snprintf(name, sizeof (name), "zio_buf_%lu", 222 (ulong_t)size); 223 zio_buf_cache[c] = kmem_cache_create(name, size, 224 align, NULL, NULL, NULL, NULL, NULL, cflags); 225 226 (void) snprintf(name, sizeof (name), "zio_data_buf_%lu", 227 (ulong_t)size); 228 zio_data_buf_cache[c] = kmem_cache_create(name, size, 229 align, NULL, NULL, NULL, NULL, NULL, data_cflags); 230 } 231 } 232 233 while (--c != 0) { 234 ASSERT(zio_buf_cache[c] != NULL); 235 if (zio_buf_cache[c - 1] == NULL) 236 zio_buf_cache[c - 1] = zio_buf_cache[c]; 237 238 ASSERT(zio_data_buf_cache[c] != NULL); 239 if (zio_data_buf_cache[c - 1] == NULL) 240 zio_data_buf_cache[c - 1] = zio_data_buf_cache[c]; 241 } 242 243 zio_inject_init(); 244 245 lz4_init(); 246 } 247 248 void 249 zio_fini(void) 250 { 251 size_t n = SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; 252 253 #if defined(ZFS_DEBUG) && !defined(_KERNEL) 254 for (size_t i = 0; i < n; i++) { 255 if (zio_buf_cache_allocs[i] != zio_buf_cache_frees[i]) 256 (void) printf("zio_fini: [%d] %llu != %llu\n", 257 (int)((i + 1) << SPA_MINBLOCKSHIFT), 258 (long long unsigned)zio_buf_cache_allocs[i], 259 (long long unsigned)zio_buf_cache_frees[i]); 260 } 261 #endif 262 263 /* 264 * The same kmem cache can show up multiple times in both zio_buf_cache 265 * and zio_data_buf_cache. Do a wasteful but trivially correct scan to 266 * sort it out. 267 */ 268 for (size_t i = 0; i < n; i++) { 269 kmem_cache_t *cache = zio_buf_cache[i]; 270 if (cache == NULL) 271 continue; 272 for (size_t j = i; j < n; j++) { 273 if (cache == zio_buf_cache[j]) 274 zio_buf_cache[j] = NULL; 275 if (cache == zio_data_buf_cache[j]) 276 zio_data_buf_cache[j] = NULL; 277 } 278 kmem_cache_destroy(cache); 279 } 280 281 for (size_t i = 0; i < n; i++) { 282 kmem_cache_t *cache = zio_data_buf_cache[i]; 283 if (cache == NULL) 284 continue; 285 for (size_t j = i; j < n; j++) { 286 if (cache == zio_data_buf_cache[j]) 287 zio_data_buf_cache[j] = NULL; 288 } 289 kmem_cache_destroy(cache); 290 } 291 292 for (size_t i = 0; i < n; i++) { 293 VERIFY3P(zio_buf_cache[i], ==, NULL); 294 VERIFY3P(zio_data_buf_cache[i], ==, NULL); 295 } 296 297 kmem_cache_destroy(zio_link_cache); 298 kmem_cache_destroy(zio_cache); 299 300 zio_inject_fini(); 301 302 lz4_fini(); 303 } 304 305 /* 306 * ========================================================================== 307 * Allocate and free I/O buffers 308 * ========================================================================== 309 */ 310 311 /* 312 * Use zio_buf_alloc to allocate ZFS metadata. This data will appear in a 313 * crashdump if the kernel panics, so use it judiciously. Obviously, it's 314 * useful to inspect ZFS metadata, but if possible, we should avoid keeping 315 * excess / transient data in-core during a crashdump. 316 */ 317 void * 318 zio_buf_alloc(size_t size) 319 { 320 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 321 322 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 323 #if defined(ZFS_DEBUG) && !defined(_KERNEL) 324 atomic_add_64(&zio_buf_cache_allocs[c], 1); 325 #endif 326 327 return (kmem_cache_alloc(zio_buf_cache[c], KM_PUSHPAGE)); 328 } 329 330 /* 331 * Use zio_data_buf_alloc to allocate data. The data will not appear in a 332 * crashdump if the kernel panics. This exists so that we will limit the amount 333 * of ZFS data that shows up in a kernel crashdump. (Thus reducing the amount 334 * of kernel heap dumped to disk when the kernel panics) 335 */ 336 void * 337 zio_data_buf_alloc(size_t size) 338 { 339 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 340 341 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 342 343 return (kmem_cache_alloc(zio_data_buf_cache[c], KM_PUSHPAGE)); 344 } 345 346 void 347 zio_buf_free(void *buf, size_t size) 348 { 349 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 350 351 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 352 #if defined(ZFS_DEBUG) && !defined(_KERNEL) 353 atomic_add_64(&zio_buf_cache_frees[c], 1); 354 #endif 355 356 kmem_cache_free(zio_buf_cache[c], buf); 357 } 358 359 void 360 zio_data_buf_free(void *buf, size_t size) 361 { 362 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT; 363 364 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT); 365 366 kmem_cache_free(zio_data_buf_cache[c], buf); 367 } 368 369 static void 370 zio_abd_free(void *abd, size_t size) 371 { 372 (void) size; 373 abd_free((abd_t *)abd); 374 } 375 376 /* 377 * ========================================================================== 378 * Push and pop I/O transform buffers 379 * ========================================================================== 380 */ 381 void 382 zio_push_transform(zio_t *zio, abd_t *data, uint64_t size, uint64_t bufsize, 383 zio_transform_func_t *transform) 384 { 385 zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP); 386 387 zt->zt_orig_abd = zio->io_abd; 388 zt->zt_orig_size = zio->io_size; 389 zt->zt_bufsize = bufsize; 390 zt->zt_transform = transform; 391 392 zt->zt_next = zio->io_transform_stack; 393 zio->io_transform_stack = zt; 394 395 zio->io_abd = data; 396 zio->io_size = size; 397 } 398 399 void 400 zio_pop_transforms(zio_t *zio) 401 { 402 zio_transform_t *zt; 403 404 while ((zt = zio->io_transform_stack) != NULL) { 405 if (zt->zt_transform != NULL) 406 zt->zt_transform(zio, 407 zt->zt_orig_abd, zt->zt_orig_size); 408 409 if (zt->zt_bufsize != 0) 410 abd_free(zio->io_abd); 411 412 zio->io_abd = zt->zt_orig_abd; 413 zio->io_size = zt->zt_orig_size; 414 zio->io_transform_stack = zt->zt_next; 415 416 kmem_free(zt, sizeof (zio_transform_t)); 417 } 418 } 419 420 /* 421 * ========================================================================== 422 * I/O transform callbacks for subblocks, decompression, and decryption 423 * ========================================================================== 424 */ 425 static void 426 zio_subblock(zio_t *zio, abd_t *data, uint64_t size) 427 { 428 ASSERT(zio->io_size > size); 429 430 if (zio->io_type == ZIO_TYPE_READ) 431 abd_copy(data, zio->io_abd, size); 432 } 433 434 static void 435 zio_decompress(zio_t *zio, abd_t *data, uint64_t size) 436 { 437 if (zio->io_error == 0) { 438 void *tmp = abd_borrow_buf(data, size); 439 int ret = zio_decompress_data(BP_GET_COMPRESS(zio->io_bp), 440 zio->io_abd, tmp, zio->io_size, size, 441 &zio->io_prop.zp_complevel); 442 abd_return_buf_copy(data, tmp, size); 443 444 if (zio_injection_enabled && ret == 0) 445 ret = zio_handle_fault_injection(zio, EINVAL); 446 447 if (ret != 0) 448 zio->io_error = SET_ERROR(EIO); 449 } 450 } 451 452 static void 453 zio_decrypt(zio_t *zio, abd_t *data, uint64_t size) 454 { 455 int ret; 456 void *tmp; 457 blkptr_t *bp = zio->io_bp; 458 spa_t *spa = zio->io_spa; 459 uint64_t dsobj = zio->io_bookmark.zb_objset; 460 uint64_t lsize = BP_GET_LSIZE(bp); 461 dmu_object_type_t ot = BP_GET_TYPE(bp); 462 uint8_t salt[ZIO_DATA_SALT_LEN]; 463 uint8_t iv[ZIO_DATA_IV_LEN]; 464 uint8_t mac[ZIO_DATA_MAC_LEN]; 465 boolean_t no_crypt = B_FALSE; 466 467 ASSERT(BP_USES_CRYPT(bp)); 468 ASSERT3U(size, !=, 0); 469 470 if (zio->io_error != 0) 471 return; 472 473 /* 474 * Verify the cksum of MACs stored in an indirect bp. It will always 475 * be possible to verify this since it does not require an encryption 476 * key. 477 */ 478 if (BP_HAS_INDIRECT_MAC_CKSUM(bp)) { 479 zio_crypt_decode_mac_bp(bp, mac); 480 481 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF) { 482 /* 483 * We haven't decompressed the data yet, but 484 * zio_crypt_do_indirect_mac_checksum() requires 485 * decompressed data to be able to parse out the MACs 486 * from the indirect block. We decompress it now and 487 * throw away the result after we are finished. 488 */ 489 tmp = zio_buf_alloc(lsize); 490 ret = zio_decompress_data(BP_GET_COMPRESS(bp), 491 zio->io_abd, tmp, zio->io_size, lsize, 492 &zio->io_prop.zp_complevel); 493 if (ret != 0) { 494 ret = SET_ERROR(EIO); 495 goto error; 496 } 497 ret = zio_crypt_do_indirect_mac_checksum(B_FALSE, 498 tmp, lsize, BP_SHOULD_BYTESWAP(bp), mac); 499 zio_buf_free(tmp, lsize); 500 } else { 501 ret = zio_crypt_do_indirect_mac_checksum_abd(B_FALSE, 502 zio->io_abd, size, BP_SHOULD_BYTESWAP(bp), mac); 503 } 504 abd_copy(data, zio->io_abd, size); 505 506 if (zio_injection_enabled && ot != DMU_OT_DNODE && ret == 0) { 507 ret = zio_handle_decrypt_injection(spa, 508 &zio->io_bookmark, ot, ECKSUM); 509 } 510 if (ret != 0) 511 goto error; 512 513 return; 514 } 515 516 /* 517 * If this is an authenticated block, just check the MAC. It would be 518 * nice to separate this out into its own flag, but for the moment 519 * enum zio_flag is out of bits. 520 */ 521 if (BP_IS_AUTHENTICATED(bp)) { 522 if (ot == DMU_OT_OBJSET) { 523 ret = spa_do_crypt_objset_mac_abd(B_FALSE, spa, 524 dsobj, zio->io_abd, size, BP_SHOULD_BYTESWAP(bp)); 525 } else { 526 zio_crypt_decode_mac_bp(bp, mac); 527 ret = spa_do_crypt_mac_abd(B_FALSE, spa, dsobj, 528 zio->io_abd, size, mac); 529 if (zio_injection_enabled && ret == 0) { 530 ret = zio_handle_decrypt_injection(spa, 531 &zio->io_bookmark, ot, ECKSUM); 532 } 533 } 534 abd_copy(data, zio->io_abd, size); 535 536 if (ret != 0) 537 goto error; 538 539 return; 540 } 541 542 zio_crypt_decode_params_bp(bp, salt, iv); 543 544 if (ot == DMU_OT_INTENT_LOG) { 545 tmp = abd_borrow_buf_copy(zio->io_abd, sizeof (zil_chain_t)); 546 zio_crypt_decode_mac_zil(tmp, mac); 547 abd_return_buf(zio->io_abd, tmp, sizeof (zil_chain_t)); 548 } else { 549 zio_crypt_decode_mac_bp(bp, mac); 550 } 551 552 ret = spa_do_crypt_abd(B_FALSE, spa, &zio->io_bookmark, BP_GET_TYPE(bp), 553 BP_GET_DEDUP(bp), BP_SHOULD_BYTESWAP(bp), salt, iv, mac, size, data, 554 zio->io_abd, &no_crypt); 555 if (no_crypt) 556 abd_copy(data, zio->io_abd, size); 557 558 if (ret != 0) 559 goto error; 560 561 return; 562 563 error: 564 /* assert that the key was found unless this was speculative */ 565 ASSERT(ret != EACCES || (zio->io_flags & ZIO_FLAG_SPECULATIVE)); 566 567 /* 568 * If there was a decryption / authentication error return EIO as 569 * the io_error. If this was not a speculative zio, create an ereport. 570 */ 571 if (ret == ECKSUM) { 572 zio->io_error = SET_ERROR(EIO); 573 if ((zio->io_flags & ZIO_FLAG_SPECULATIVE) == 0) { 574 spa_log_error(spa, &zio->io_bookmark); 575 (void) zfs_ereport_post(FM_EREPORT_ZFS_AUTHENTICATION, 576 spa, NULL, &zio->io_bookmark, zio, 0); 577 } 578 } else { 579 zio->io_error = ret; 580 } 581 } 582 583 /* 584 * ========================================================================== 585 * I/O parent/child relationships and pipeline interlocks 586 * ========================================================================== 587 */ 588 zio_t * 589 zio_walk_parents(zio_t *cio, zio_link_t **zl) 590 { 591 list_t *pl = &cio->io_parent_list; 592 593 *zl = (*zl == NULL) ? list_head(pl) : list_next(pl, *zl); 594 if (*zl == NULL) 595 return (NULL); 596 597 ASSERT((*zl)->zl_child == cio); 598 return ((*zl)->zl_parent); 599 } 600 601 zio_t * 602 zio_walk_children(zio_t *pio, zio_link_t **zl) 603 { 604 list_t *cl = &pio->io_child_list; 605 606 ASSERT(MUTEX_HELD(&pio->io_lock)); 607 608 *zl = (*zl == NULL) ? list_head(cl) : list_next(cl, *zl); 609 if (*zl == NULL) 610 return (NULL); 611 612 ASSERT((*zl)->zl_parent == pio); 613 return ((*zl)->zl_child); 614 } 615 616 zio_t * 617 zio_unique_parent(zio_t *cio) 618 { 619 zio_link_t *zl = NULL; 620 zio_t *pio = zio_walk_parents(cio, &zl); 621 622 VERIFY3P(zio_walk_parents(cio, &zl), ==, NULL); 623 return (pio); 624 } 625 626 void 627 zio_add_child(zio_t *pio, zio_t *cio) 628 { 629 zio_link_t *zl = kmem_cache_alloc(zio_link_cache, KM_SLEEP); 630 631 /* 632 * Logical I/Os can have logical, gang, or vdev children. 633 * Gang I/Os can have gang or vdev children. 634 * Vdev I/Os can only have vdev children. 635 * The following ASSERT captures all of these constraints. 636 */ 637 ASSERT3S(cio->io_child_type, <=, pio->io_child_type); 638 639 zl->zl_parent = pio; 640 zl->zl_child = cio; 641 642 mutex_enter(&pio->io_lock); 643 mutex_enter(&cio->io_lock); 644 645 ASSERT(pio->io_state[ZIO_WAIT_DONE] == 0); 646 647 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 648 pio->io_children[cio->io_child_type][w] += !cio->io_state[w]; 649 650 list_insert_head(&pio->io_child_list, zl); 651 list_insert_head(&cio->io_parent_list, zl); 652 653 pio->io_child_count++; 654 cio->io_parent_count++; 655 656 mutex_exit(&cio->io_lock); 657 mutex_exit(&pio->io_lock); 658 } 659 660 static void 661 zio_remove_child(zio_t *pio, zio_t *cio, zio_link_t *zl) 662 { 663 ASSERT(zl->zl_parent == pio); 664 ASSERT(zl->zl_child == cio); 665 666 mutex_enter(&pio->io_lock); 667 mutex_enter(&cio->io_lock); 668 669 list_remove(&pio->io_child_list, zl); 670 list_remove(&cio->io_parent_list, zl); 671 672 pio->io_child_count--; 673 cio->io_parent_count--; 674 675 mutex_exit(&cio->io_lock); 676 mutex_exit(&pio->io_lock); 677 kmem_cache_free(zio_link_cache, zl); 678 } 679 680 static boolean_t 681 zio_wait_for_children(zio_t *zio, uint8_t childbits, enum zio_wait_type wait) 682 { 683 boolean_t waiting = B_FALSE; 684 685 mutex_enter(&zio->io_lock); 686 ASSERT(zio->io_stall == NULL); 687 for (int c = 0; c < ZIO_CHILD_TYPES; c++) { 688 if (!(ZIO_CHILD_BIT_IS_SET(childbits, c))) 689 continue; 690 691 uint64_t *countp = &zio->io_children[c][wait]; 692 if (*countp != 0) { 693 zio->io_stage >>= 1; 694 ASSERT3U(zio->io_stage, !=, ZIO_STAGE_OPEN); 695 zio->io_stall = countp; 696 waiting = B_TRUE; 697 break; 698 } 699 } 700 mutex_exit(&zio->io_lock); 701 return (waiting); 702 } 703 704 __attribute__((always_inline)) 705 static inline void 706 zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait, 707 zio_t **next_to_executep) 708 { 709 uint64_t *countp = &pio->io_children[zio->io_child_type][wait]; 710 int *errorp = &pio->io_child_error[zio->io_child_type]; 711 712 mutex_enter(&pio->io_lock); 713 if (zio->io_error && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE)) 714 *errorp = zio_worst_error(*errorp, zio->io_error); 715 pio->io_reexecute |= zio->io_reexecute; 716 ASSERT3U(*countp, >, 0); 717 718 (*countp)--; 719 720 if (*countp == 0 && pio->io_stall == countp) { 721 zio_taskq_type_t type = 722 pio->io_stage < ZIO_STAGE_VDEV_IO_START ? ZIO_TASKQ_ISSUE : 723 ZIO_TASKQ_INTERRUPT; 724 pio->io_stall = NULL; 725 mutex_exit(&pio->io_lock); 726 727 /* 728 * If we can tell the caller to execute this parent next, do 729 * so. Otherwise dispatch the parent zio as its own task. 730 * 731 * Having the caller execute the parent when possible reduces 732 * locking on the zio taskq's, reduces context switch 733 * overhead, and has no recursion penalty. Note that one 734 * read from disk typically causes at least 3 zio's: a 735 * zio_null(), the logical zio_read(), and then a physical 736 * zio. When the physical ZIO completes, we are able to call 737 * zio_done() on all 3 of these zio's from one invocation of 738 * zio_execute() by returning the parent back to 739 * zio_execute(). Since the parent isn't executed until this 740 * thread returns back to zio_execute(), the caller should do 741 * so promptly. 742 * 743 * In other cases, dispatching the parent prevents 744 * overflowing the stack when we have deeply nested 745 * parent-child relationships, as we do with the "mega zio" 746 * of writes for spa_sync(), and the chain of ZIL blocks. 747 */ 748 if (next_to_executep != NULL && *next_to_executep == NULL) { 749 *next_to_executep = pio; 750 } else { 751 zio_taskq_dispatch(pio, type, B_FALSE); 752 } 753 } else { 754 mutex_exit(&pio->io_lock); 755 } 756 } 757 758 static void 759 zio_inherit_child_errors(zio_t *zio, enum zio_child c) 760 { 761 if (zio->io_child_error[c] != 0 && zio->io_error == 0) 762 zio->io_error = zio->io_child_error[c]; 763 } 764 765 int 766 zio_bookmark_compare(const void *x1, const void *x2) 767 { 768 const zio_t *z1 = x1; 769 const zio_t *z2 = x2; 770 771 if (z1->io_bookmark.zb_objset < z2->io_bookmark.zb_objset) 772 return (-1); 773 if (z1->io_bookmark.zb_objset > z2->io_bookmark.zb_objset) 774 return (1); 775 776 if (z1->io_bookmark.zb_object < z2->io_bookmark.zb_object) 777 return (-1); 778 if (z1->io_bookmark.zb_object > z2->io_bookmark.zb_object) 779 return (1); 780 781 if (z1->io_bookmark.zb_level < z2->io_bookmark.zb_level) 782 return (-1); 783 if (z1->io_bookmark.zb_level > z2->io_bookmark.zb_level) 784 return (1); 785 786 if (z1->io_bookmark.zb_blkid < z2->io_bookmark.zb_blkid) 787 return (-1); 788 if (z1->io_bookmark.zb_blkid > z2->io_bookmark.zb_blkid) 789 return (1); 790 791 if (z1 < z2) 792 return (-1); 793 if (z1 > z2) 794 return (1); 795 796 return (0); 797 } 798 799 /* 800 * ========================================================================== 801 * Create the various types of I/O (read, write, free, etc) 802 * ========================================================================== 803 */ 804 static zio_t * 805 zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 806 abd_t *data, uint64_t lsize, uint64_t psize, zio_done_func_t *done, 807 void *private, zio_type_t type, zio_priority_t priority, 808 enum zio_flag flags, vdev_t *vd, uint64_t offset, 809 const zbookmark_phys_t *zb, enum zio_stage stage, 810 enum zio_stage pipeline) 811 { 812 zio_t *zio; 813 814 IMPLY(type != ZIO_TYPE_TRIM, psize <= SPA_MAXBLOCKSIZE); 815 ASSERT(P2PHASE(psize, SPA_MINBLOCKSIZE) == 0); 816 ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0); 817 818 ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER)); 819 ASSERT(!bp || !(flags & ZIO_FLAG_CONFIG_WRITER)); 820 ASSERT(vd || stage == ZIO_STAGE_OPEN); 821 822 IMPLY(lsize != psize, (flags & ZIO_FLAG_RAW_COMPRESS) != 0); 823 824 zio = kmem_cache_alloc(zio_cache, KM_SLEEP); 825 bzero(zio, sizeof (zio_t)); 826 827 mutex_init(&zio->io_lock, NULL, MUTEX_NOLOCKDEP, NULL); 828 cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL); 829 830 list_create(&zio->io_parent_list, sizeof (zio_link_t), 831 offsetof(zio_link_t, zl_parent_node)); 832 list_create(&zio->io_child_list, sizeof (zio_link_t), 833 offsetof(zio_link_t, zl_child_node)); 834 metaslab_trace_init(&zio->io_alloc_list); 835 836 if (vd != NULL) 837 zio->io_child_type = ZIO_CHILD_VDEV; 838 else if (flags & ZIO_FLAG_GANG_CHILD) 839 zio->io_child_type = ZIO_CHILD_GANG; 840 else if (flags & ZIO_FLAG_DDT_CHILD) 841 zio->io_child_type = ZIO_CHILD_DDT; 842 else 843 zio->io_child_type = ZIO_CHILD_LOGICAL; 844 845 if (bp != NULL) { 846 zio->io_bp = (blkptr_t *)bp; 847 zio->io_bp_copy = *bp; 848 zio->io_bp_orig = *bp; 849 if (type != ZIO_TYPE_WRITE || 850 zio->io_child_type == ZIO_CHILD_DDT) 851 zio->io_bp = &zio->io_bp_copy; /* so caller can free */ 852 if (zio->io_child_type == ZIO_CHILD_LOGICAL) 853 zio->io_logical = zio; 854 if (zio->io_child_type > ZIO_CHILD_GANG && BP_IS_GANG(bp)) 855 pipeline |= ZIO_GANG_STAGES; 856 } 857 858 zio->io_spa = spa; 859 zio->io_txg = txg; 860 zio->io_done = done; 861 zio->io_private = private; 862 zio->io_type = type; 863 zio->io_priority = priority; 864 zio->io_vd = vd; 865 zio->io_offset = offset; 866 zio->io_orig_abd = zio->io_abd = data; 867 zio->io_orig_size = zio->io_size = psize; 868 zio->io_lsize = lsize; 869 zio->io_orig_flags = zio->io_flags = flags; 870 zio->io_orig_stage = zio->io_stage = stage; 871 zio->io_orig_pipeline = zio->io_pipeline = pipeline; 872 zio->io_pipeline_trace = ZIO_STAGE_OPEN; 873 874 zio->io_state[ZIO_WAIT_READY] = (stage >= ZIO_STAGE_READY); 875 zio->io_state[ZIO_WAIT_DONE] = (stage >= ZIO_STAGE_DONE); 876 877 if (zb != NULL) 878 zio->io_bookmark = *zb; 879 880 if (pio != NULL) { 881 zio->io_metaslab_class = pio->io_metaslab_class; 882 if (zio->io_logical == NULL) 883 zio->io_logical = pio->io_logical; 884 if (zio->io_child_type == ZIO_CHILD_GANG) 885 zio->io_gang_leader = pio->io_gang_leader; 886 zio_add_child(pio, zio); 887 } 888 889 taskq_init_ent(&zio->io_tqent); 890 891 return (zio); 892 } 893 894 static void 895 zio_destroy(zio_t *zio) 896 { 897 metaslab_trace_fini(&zio->io_alloc_list); 898 list_destroy(&zio->io_parent_list); 899 list_destroy(&zio->io_child_list); 900 mutex_destroy(&zio->io_lock); 901 cv_destroy(&zio->io_cv); 902 kmem_cache_free(zio_cache, zio); 903 } 904 905 zio_t * 906 zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, zio_done_func_t *done, 907 void *private, enum zio_flag flags) 908 { 909 zio_t *zio; 910 911 zio = zio_create(pio, spa, 0, NULL, NULL, 0, 0, done, private, 912 ZIO_TYPE_NULL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL, 913 ZIO_STAGE_OPEN, ZIO_INTERLOCK_PIPELINE); 914 915 return (zio); 916 } 917 918 zio_t * 919 zio_root(spa_t *spa, zio_done_func_t *done, void *private, enum zio_flag flags) 920 { 921 return (zio_null(NULL, spa, NULL, done, private, flags)); 922 } 923 924 static int 925 zfs_blkptr_verify_log(spa_t *spa, const blkptr_t *bp, 926 enum blk_verify_flag blk_verify, const char *fmt, ...) 927 { 928 va_list adx; 929 char buf[256]; 930 931 va_start(adx, fmt); 932 (void) vsnprintf(buf, sizeof (buf), fmt, adx); 933 va_end(adx); 934 935 switch (blk_verify) { 936 case BLK_VERIFY_HALT: 937 dprintf_bp(bp, "blkptr at %p dprintf_bp():", bp); 938 zfs_panic_recover("%s: %s", spa_name(spa), buf); 939 break; 940 case BLK_VERIFY_LOG: 941 zfs_dbgmsg("%s: %s", spa_name(spa), buf); 942 break; 943 case BLK_VERIFY_ONLY: 944 break; 945 } 946 947 return (1); 948 } 949 950 /* 951 * Verify the block pointer fields contain reasonable values. This means 952 * it only contains known object types, checksum/compression identifiers, 953 * block sizes within the maximum allowed limits, valid DVAs, etc. 954 * 955 * If everything checks out B_TRUE is returned. The zfs_blkptr_verify 956 * argument controls the behavior when an invalid field is detected. 957 * 958 * Modes for zfs_blkptr_verify: 959 * 1) BLK_VERIFY_ONLY (evaluate the block) 960 * 2) BLK_VERIFY_LOG (evaluate the block and log problems) 961 * 3) BLK_VERIFY_HALT (call zfs_panic_recover on error) 962 */ 963 boolean_t 964 zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp, boolean_t config_held, 965 enum blk_verify_flag blk_verify) 966 { 967 int errors = 0; 968 969 if (!DMU_OT_IS_VALID(BP_GET_TYPE(bp))) { 970 errors += zfs_blkptr_verify_log(spa, bp, blk_verify, 971 "blkptr at %p has invalid TYPE %llu", 972 bp, (longlong_t)BP_GET_TYPE(bp)); 973 } 974 if (BP_GET_CHECKSUM(bp) >= ZIO_CHECKSUM_FUNCTIONS || 975 BP_GET_CHECKSUM(bp) <= ZIO_CHECKSUM_ON) { 976 errors += zfs_blkptr_verify_log(spa, bp, blk_verify, 977 "blkptr at %p has invalid CHECKSUM %llu", 978 bp, (longlong_t)BP_GET_CHECKSUM(bp)); 979 } 980 if (BP_GET_COMPRESS(bp) >= ZIO_COMPRESS_FUNCTIONS || 981 BP_GET_COMPRESS(bp) <= ZIO_COMPRESS_ON) { 982 errors += zfs_blkptr_verify_log(spa, bp, blk_verify, 983 "blkptr at %p has invalid COMPRESS %llu", 984 bp, (longlong_t)BP_GET_COMPRESS(bp)); 985 } 986 if (BP_GET_LSIZE(bp) > SPA_MAXBLOCKSIZE) { 987 errors += zfs_blkptr_verify_log(spa, bp, blk_verify, 988 "blkptr at %p has invalid LSIZE %llu", 989 bp, (longlong_t)BP_GET_LSIZE(bp)); 990 } 991 if (BP_GET_PSIZE(bp) > SPA_MAXBLOCKSIZE) { 992 errors += zfs_blkptr_verify_log(spa, bp, blk_verify, 993 "blkptr at %p has invalid PSIZE %llu", 994 bp, (longlong_t)BP_GET_PSIZE(bp)); 995 } 996 997 if (BP_IS_EMBEDDED(bp)) { 998 if (BPE_GET_ETYPE(bp) >= NUM_BP_EMBEDDED_TYPES) { 999 errors += zfs_blkptr_verify_log(spa, bp, blk_verify, 1000 "blkptr at %p has invalid ETYPE %llu", 1001 bp, (longlong_t)BPE_GET_ETYPE(bp)); 1002 } 1003 } 1004 1005 /* 1006 * Do not verify individual DVAs if the config is not trusted. This 1007 * will be done once the zio is executed in vdev_mirror_map_alloc. 1008 */ 1009 if (!spa->spa_trust_config) 1010 return (errors == 0); 1011 1012 if (!config_held) 1013 spa_config_enter(spa, SCL_VDEV, bp, RW_READER); 1014 else 1015 ASSERT(spa_config_held(spa, SCL_VDEV, RW_WRITER)); 1016 /* 1017 * Pool-specific checks. 1018 * 1019 * Note: it would be nice to verify that the blk_birth and 1020 * BP_PHYSICAL_BIRTH() are not too large. However, spa_freeze() 1021 * allows the birth time of log blocks (and dmu_sync()-ed blocks 1022 * that are in the log) to be arbitrarily large. 1023 */ 1024 for (int i = 0; i < BP_GET_NDVAS(bp); i++) { 1025 const dva_t *dva = &bp->blk_dva[i]; 1026 uint64_t vdevid = DVA_GET_VDEV(dva); 1027 1028 if (vdevid >= spa->spa_root_vdev->vdev_children) { 1029 errors += zfs_blkptr_verify_log(spa, bp, blk_verify, 1030 "blkptr at %p DVA %u has invalid VDEV %llu", 1031 bp, i, (longlong_t)vdevid); 1032 continue; 1033 } 1034 vdev_t *vd = spa->spa_root_vdev->vdev_child[vdevid]; 1035 if (vd == NULL) { 1036 errors += zfs_blkptr_verify_log(spa, bp, blk_verify, 1037 "blkptr at %p DVA %u has invalid VDEV %llu", 1038 bp, i, (longlong_t)vdevid); 1039 continue; 1040 } 1041 if (vd->vdev_ops == &vdev_hole_ops) { 1042 errors += zfs_blkptr_verify_log(spa, bp, blk_verify, 1043 "blkptr at %p DVA %u has hole VDEV %llu", 1044 bp, i, (longlong_t)vdevid); 1045 continue; 1046 } 1047 if (vd->vdev_ops == &vdev_missing_ops) { 1048 /* 1049 * "missing" vdevs are valid during import, but we 1050 * don't have their detailed info (e.g. asize), so 1051 * we can't perform any more checks on them. 1052 */ 1053 continue; 1054 } 1055 uint64_t offset = DVA_GET_OFFSET(dva); 1056 uint64_t asize = DVA_GET_ASIZE(dva); 1057 if (DVA_GET_GANG(dva)) 1058 asize = vdev_gang_header_asize(vd); 1059 if (offset + asize > vd->vdev_asize) { 1060 errors += zfs_blkptr_verify_log(spa, bp, blk_verify, 1061 "blkptr at %p DVA %u has invalid OFFSET %llu", 1062 bp, i, (longlong_t)offset); 1063 } 1064 } 1065 if (errors > 0) 1066 dprintf_bp(bp, "blkptr at %p dprintf_bp():", bp); 1067 if (!config_held) 1068 spa_config_exit(spa, SCL_VDEV, bp); 1069 1070 return (errors == 0); 1071 } 1072 1073 boolean_t 1074 zfs_dva_valid(spa_t *spa, const dva_t *dva, const blkptr_t *bp) 1075 { 1076 (void) bp; 1077 uint64_t vdevid = DVA_GET_VDEV(dva); 1078 1079 if (vdevid >= spa->spa_root_vdev->vdev_children) 1080 return (B_FALSE); 1081 1082 vdev_t *vd = spa->spa_root_vdev->vdev_child[vdevid]; 1083 if (vd == NULL) 1084 return (B_FALSE); 1085 1086 if (vd->vdev_ops == &vdev_hole_ops) 1087 return (B_FALSE); 1088 1089 if (vd->vdev_ops == &vdev_missing_ops) { 1090 return (B_FALSE); 1091 } 1092 1093 uint64_t offset = DVA_GET_OFFSET(dva); 1094 uint64_t asize = DVA_GET_ASIZE(dva); 1095 1096 if (DVA_GET_GANG(dva)) 1097 asize = vdev_gang_header_asize(vd); 1098 if (offset + asize > vd->vdev_asize) 1099 return (B_FALSE); 1100 1101 return (B_TRUE); 1102 } 1103 1104 zio_t * 1105 zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, 1106 abd_t *data, uint64_t size, zio_done_func_t *done, void *private, 1107 zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb) 1108 { 1109 zio_t *zio; 1110 1111 zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp, 1112 data, size, size, done, private, 1113 ZIO_TYPE_READ, priority, flags, NULL, 0, zb, 1114 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 1115 ZIO_DDT_CHILD_READ_PIPELINE : ZIO_READ_PIPELINE); 1116 1117 return (zio); 1118 } 1119 1120 zio_t * 1121 zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, 1122 abd_t *data, uint64_t lsize, uint64_t psize, const zio_prop_t *zp, 1123 zio_done_func_t *ready, zio_done_func_t *children_ready, 1124 zio_done_func_t *physdone, zio_done_func_t *done, 1125 void *private, zio_priority_t priority, enum zio_flag flags, 1126 const zbookmark_phys_t *zb) 1127 { 1128 zio_t *zio; 1129 1130 ASSERT(zp->zp_checksum >= ZIO_CHECKSUM_OFF && 1131 zp->zp_checksum < ZIO_CHECKSUM_FUNCTIONS && 1132 zp->zp_compress >= ZIO_COMPRESS_OFF && 1133 zp->zp_compress < ZIO_COMPRESS_FUNCTIONS && 1134 DMU_OT_IS_VALID(zp->zp_type) && 1135 zp->zp_level < 32 && 1136 zp->zp_copies > 0 && 1137 zp->zp_copies <= spa_max_replication(spa)); 1138 1139 zio = zio_create(pio, spa, txg, bp, data, lsize, psize, done, private, 1140 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb, 1141 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ? 1142 ZIO_DDT_CHILD_WRITE_PIPELINE : ZIO_WRITE_PIPELINE); 1143 1144 zio->io_ready = ready; 1145 zio->io_children_ready = children_ready; 1146 zio->io_physdone = physdone; 1147 zio->io_prop = *zp; 1148 1149 /* 1150 * Data can be NULL if we are going to call zio_write_override() to 1151 * provide the already-allocated BP. But we may need the data to 1152 * verify a dedup hit (if requested). In this case, don't try to 1153 * dedup (just take the already-allocated BP verbatim). Encrypted 1154 * dedup blocks need data as well so we also disable dedup in this 1155 * case. 1156 */ 1157 if (data == NULL && 1158 (zio->io_prop.zp_dedup_verify || zio->io_prop.zp_encrypt)) { 1159 zio->io_prop.zp_dedup = zio->io_prop.zp_dedup_verify = B_FALSE; 1160 } 1161 1162 return (zio); 1163 } 1164 1165 zio_t * 1166 zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, abd_t *data, 1167 uint64_t size, zio_done_func_t *done, void *private, 1168 zio_priority_t priority, enum zio_flag flags, zbookmark_phys_t *zb) 1169 { 1170 zio_t *zio; 1171 1172 zio = zio_create(pio, spa, txg, bp, data, size, size, done, private, 1173 ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_IO_REWRITE, NULL, 0, zb, 1174 ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE); 1175 1176 return (zio); 1177 } 1178 1179 void 1180 zio_write_override(zio_t *zio, blkptr_t *bp, int copies, boolean_t nopwrite) 1181 { 1182 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 1183 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1184 ASSERT(zio->io_stage == ZIO_STAGE_OPEN); 1185 ASSERT(zio->io_txg == spa_syncing_txg(zio->io_spa)); 1186 1187 /* 1188 * We must reset the io_prop to match the values that existed 1189 * when the bp was first written by dmu_sync() keeping in mind 1190 * that nopwrite and dedup are mutually exclusive. 1191 */ 1192 zio->io_prop.zp_dedup = nopwrite ? B_FALSE : zio->io_prop.zp_dedup; 1193 zio->io_prop.zp_nopwrite = nopwrite; 1194 zio->io_prop.zp_copies = copies; 1195 zio->io_bp_override = bp; 1196 } 1197 1198 void 1199 zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp) 1200 { 1201 1202 (void) zfs_blkptr_verify(spa, bp, B_FALSE, BLK_VERIFY_HALT); 1203 1204 /* 1205 * The check for EMBEDDED is a performance optimization. We 1206 * process the free here (by ignoring it) rather than 1207 * putting it on the list and then processing it in zio_free_sync(). 1208 */ 1209 if (BP_IS_EMBEDDED(bp)) 1210 return; 1211 metaslab_check_free(spa, bp); 1212 1213 /* 1214 * Frees that are for the currently-syncing txg, are not going to be 1215 * deferred, and which will not need to do a read (i.e. not GANG or 1216 * DEDUP), can be processed immediately. Otherwise, put them on the 1217 * in-memory list for later processing. 1218 * 1219 * Note that we only defer frees after zfs_sync_pass_deferred_free 1220 * when the log space map feature is disabled. [see relevant comment 1221 * in spa_sync_iterate_to_convergence()] 1222 */ 1223 if (BP_IS_GANG(bp) || 1224 BP_GET_DEDUP(bp) || 1225 txg != spa->spa_syncing_txg || 1226 (spa_sync_pass(spa) >= zfs_sync_pass_deferred_free && 1227 !spa_feature_is_active(spa, SPA_FEATURE_LOG_SPACEMAP))) { 1228 bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp); 1229 } else { 1230 VERIFY3P(zio_free_sync(NULL, spa, txg, bp, 0), ==, NULL); 1231 } 1232 } 1233 1234 /* 1235 * To improve performance, this function may return NULL if we were able 1236 * to do the free immediately. This avoids the cost of creating a zio 1237 * (and linking it to the parent, etc). 1238 */ 1239 zio_t * 1240 zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 1241 enum zio_flag flags) 1242 { 1243 ASSERT(!BP_IS_HOLE(bp)); 1244 ASSERT(spa_syncing_txg(spa) == txg); 1245 1246 if (BP_IS_EMBEDDED(bp)) 1247 return (NULL); 1248 1249 metaslab_check_free(spa, bp); 1250 arc_freed(spa, bp); 1251 dsl_scan_freed(spa, bp); 1252 1253 if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp)) { 1254 /* 1255 * GANG and DEDUP blocks can induce a read (for the gang block 1256 * header, or the DDT), so issue them asynchronously so that 1257 * this thread is not tied up. 1258 */ 1259 enum zio_stage stage = 1260 ZIO_FREE_PIPELINE | ZIO_STAGE_ISSUE_ASYNC; 1261 1262 return (zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 1263 BP_GET_PSIZE(bp), NULL, NULL, 1264 ZIO_TYPE_FREE, ZIO_PRIORITY_NOW, 1265 flags, NULL, 0, NULL, ZIO_STAGE_OPEN, stage)); 1266 } else { 1267 metaslab_free(spa, bp, txg, B_FALSE); 1268 return (NULL); 1269 } 1270 } 1271 1272 zio_t * 1273 zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp, 1274 zio_done_func_t *done, void *private, enum zio_flag flags) 1275 { 1276 zio_t *zio; 1277 1278 (void) zfs_blkptr_verify(spa, bp, flags & ZIO_FLAG_CONFIG_WRITER, 1279 BLK_VERIFY_HALT); 1280 1281 if (BP_IS_EMBEDDED(bp)) 1282 return (zio_null(pio, spa, NULL, NULL, NULL, 0)); 1283 1284 /* 1285 * A claim is an allocation of a specific block. Claims are needed 1286 * to support immediate writes in the intent log. The issue is that 1287 * immediate writes contain committed data, but in a txg that was 1288 * *not* committed. Upon opening the pool after an unclean shutdown, 1289 * the intent log claims all blocks that contain immediate write data 1290 * so that the SPA knows they're in use. 1291 * 1292 * All claims *must* be resolved in the first txg -- before the SPA 1293 * starts allocating blocks -- so that nothing is allocated twice. 1294 * If txg == 0 we just verify that the block is claimable. 1295 */ 1296 ASSERT3U(spa->spa_uberblock.ub_rootbp.blk_birth, <, 1297 spa_min_claim_txg(spa)); 1298 ASSERT(txg == spa_min_claim_txg(spa) || txg == 0); 1299 ASSERT(!BP_GET_DEDUP(bp) || !spa_writeable(spa)); /* zdb(8) */ 1300 1301 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp), 1302 BP_GET_PSIZE(bp), done, private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW, 1303 flags, NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE); 1304 ASSERT0(zio->io_queued_timestamp); 1305 1306 return (zio); 1307 } 1308 1309 zio_t * 1310 zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd, 1311 zio_done_func_t *done, void *private, enum zio_flag flags) 1312 { 1313 zio_t *zio; 1314 int c; 1315 1316 if (vd->vdev_children == 0) { 1317 zio = zio_create(pio, spa, 0, NULL, NULL, 0, 0, done, private, 1318 ZIO_TYPE_IOCTL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL, 1319 ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE); 1320 1321 zio->io_cmd = cmd; 1322 } else { 1323 zio = zio_null(pio, spa, NULL, NULL, NULL, flags); 1324 1325 for (c = 0; c < vd->vdev_children; c++) 1326 zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd, 1327 done, private, flags)); 1328 } 1329 1330 return (zio); 1331 } 1332 1333 zio_t * 1334 zio_trim(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 1335 zio_done_func_t *done, void *private, zio_priority_t priority, 1336 enum zio_flag flags, enum trim_flag trim_flags) 1337 { 1338 zio_t *zio; 1339 1340 ASSERT0(vd->vdev_children); 1341 ASSERT0(P2PHASE(offset, 1ULL << vd->vdev_ashift)); 1342 ASSERT0(P2PHASE(size, 1ULL << vd->vdev_ashift)); 1343 ASSERT3U(size, !=, 0); 1344 1345 zio = zio_create(pio, vd->vdev_spa, 0, NULL, NULL, size, size, done, 1346 private, ZIO_TYPE_TRIM, priority, flags | ZIO_FLAG_PHYSICAL, 1347 vd, offset, NULL, ZIO_STAGE_OPEN, ZIO_TRIM_PIPELINE); 1348 zio->io_trim_flags = trim_flags; 1349 1350 return (zio); 1351 } 1352 1353 zio_t * 1354 zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 1355 abd_t *data, int checksum, zio_done_func_t *done, void *private, 1356 zio_priority_t priority, enum zio_flag flags, boolean_t labels) 1357 { 1358 zio_t *zio; 1359 1360 ASSERT(vd->vdev_children == 0); 1361 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 1362 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 1363 ASSERT3U(offset + size, <=, vd->vdev_psize); 1364 1365 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, size, done, 1366 private, ZIO_TYPE_READ, priority, flags | ZIO_FLAG_PHYSICAL, vd, 1367 offset, NULL, ZIO_STAGE_OPEN, ZIO_READ_PHYS_PIPELINE); 1368 1369 zio->io_prop.zp_checksum = checksum; 1370 1371 return (zio); 1372 } 1373 1374 zio_t * 1375 zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size, 1376 abd_t *data, int checksum, zio_done_func_t *done, void *private, 1377 zio_priority_t priority, enum zio_flag flags, boolean_t labels) 1378 { 1379 zio_t *zio; 1380 1381 ASSERT(vd->vdev_children == 0); 1382 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE || 1383 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE); 1384 ASSERT3U(offset + size, <=, vd->vdev_psize); 1385 1386 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, size, done, 1387 private, ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_PHYSICAL, vd, 1388 offset, NULL, ZIO_STAGE_OPEN, ZIO_WRITE_PHYS_PIPELINE); 1389 1390 zio->io_prop.zp_checksum = checksum; 1391 1392 if (zio_checksum_table[checksum].ci_flags & ZCHECKSUM_FLAG_EMBEDDED) { 1393 /* 1394 * zec checksums are necessarily destructive -- they modify 1395 * the end of the write buffer to hold the verifier/checksum. 1396 * Therefore, we must make a local copy in case the data is 1397 * being written to multiple places in parallel. 1398 */ 1399 abd_t *wbuf = abd_alloc_sametype(data, size); 1400 abd_copy(wbuf, data, size); 1401 1402 zio_push_transform(zio, wbuf, size, size, NULL); 1403 } 1404 1405 return (zio); 1406 } 1407 1408 /* 1409 * Create a child I/O to do some work for us. 1410 */ 1411 zio_t * 1412 zio_vdev_child_io(zio_t *pio, blkptr_t *bp, vdev_t *vd, uint64_t offset, 1413 abd_t *data, uint64_t size, int type, zio_priority_t priority, 1414 enum zio_flag flags, zio_done_func_t *done, void *private) 1415 { 1416 enum zio_stage pipeline = ZIO_VDEV_CHILD_PIPELINE; 1417 zio_t *zio; 1418 1419 /* 1420 * vdev child I/Os do not propagate their error to the parent. 1421 * Therefore, for correct operation the caller *must* check for 1422 * and handle the error in the child i/o's done callback. 1423 * The only exceptions are i/os that we don't care about 1424 * (OPTIONAL or REPAIR). 1425 */ 1426 ASSERT((flags & ZIO_FLAG_OPTIONAL) || (flags & ZIO_FLAG_IO_REPAIR) || 1427 done != NULL); 1428 1429 if (type == ZIO_TYPE_READ && bp != NULL) { 1430 /* 1431 * If we have the bp, then the child should perform the 1432 * checksum and the parent need not. This pushes error 1433 * detection as close to the leaves as possible and 1434 * eliminates redundant checksums in the interior nodes. 1435 */ 1436 pipeline |= ZIO_STAGE_CHECKSUM_VERIFY; 1437 pio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 1438 } 1439 1440 if (vd->vdev_ops->vdev_op_leaf) { 1441 ASSERT0(vd->vdev_children); 1442 offset += VDEV_LABEL_START_SIZE; 1443 } 1444 1445 flags |= ZIO_VDEV_CHILD_FLAGS(pio); 1446 1447 /* 1448 * If we've decided to do a repair, the write is not speculative -- 1449 * even if the original read was. 1450 */ 1451 if (flags & ZIO_FLAG_IO_REPAIR) 1452 flags &= ~ZIO_FLAG_SPECULATIVE; 1453 1454 /* 1455 * If we're creating a child I/O that is not associated with a 1456 * top-level vdev, then the child zio is not an allocating I/O. 1457 * If this is a retried I/O then we ignore it since we will 1458 * have already processed the original allocating I/O. 1459 */ 1460 if (flags & ZIO_FLAG_IO_ALLOCATING && 1461 (vd != vd->vdev_top || (flags & ZIO_FLAG_IO_RETRY))) { 1462 ASSERT(pio->io_metaslab_class != NULL); 1463 ASSERT(pio->io_metaslab_class->mc_alloc_throttle_enabled); 1464 ASSERT(type == ZIO_TYPE_WRITE); 1465 ASSERT(priority == ZIO_PRIORITY_ASYNC_WRITE); 1466 ASSERT(!(flags & ZIO_FLAG_IO_REPAIR)); 1467 ASSERT(!(pio->io_flags & ZIO_FLAG_IO_REWRITE) || 1468 pio->io_child_type == ZIO_CHILD_GANG); 1469 1470 flags &= ~ZIO_FLAG_IO_ALLOCATING; 1471 } 1472 1473 1474 zio = zio_create(pio, pio->io_spa, pio->io_txg, bp, data, size, size, 1475 done, private, type, priority, flags, vd, offset, &pio->io_bookmark, 1476 ZIO_STAGE_VDEV_IO_START >> 1, pipeline); 1477 ASSERT3U(zio->io_child_type, ==, ZIO_CHILD_VDEV); 1478 1479 zio->io_physdone = pio->io_physdone; 1480 if (vd->vdev_ops->vdev_op_leaf && zio->io_logical != NULL) 1481 zio->io_logical->io_phys_children++; 1482 1483 return (zio); 1484 } 1485 1486 zio_t * 1487 zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, abd_t *data, uint64_t size, 1488 zio_type_t type, zio_priority_t priority, enum zio_flag flags, 1489 zio_done_func_t *done, void *private) 1490 { 1491 zio_t *zio; 1492 1493 ASSERT(vd->vdev_ops->vdev_op_leaf); 1494 1495 zio = zio_create(NULL, vd->vdev_spa, 0, NULL, 1496 data, size, size, done, private, type, priority, 1497 flags | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY | ZIO_FLAG_DELEGATED, 1498 vd, offset, NULL, 1499 ZIO_STAGE_VDEV_IO_START >> 1, ZIO_VDEV_CHILD_PIPELINE); 1500 1501 return (zio); 1502 } 1503 1504 void 1505 zio_flush(zio_t *zio, vdev_t *vd) 1506 { 1507 zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE, 1508 NULL, NULL, 1509 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY)); 1510 } 1511 1512 void 1513 zio_shrink(zio_t *zio, uint64_t size) 1514 { 1515 ASSERT3P(zio->io_executor, ==, NULL); 1516 ASSERT3U(zio->io_orig_size, ==, zio->io_size); 1517 ASSERT3U(size, <=, zio->io_size); 1518 1519 /* 1520 * We don't shrink for raidz because of problems with the 1521 * reconstruction when reading back less than the block size. 1522 * Note, BP_IS_RAIDZ() assumes no compression. 1523 */ 1524 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF); 1525 if (!BP_IS_RAIDZ(zio->io_bp)) { 1526 /* we are not doing a raw write */ 1527 ASSERT3U(zio->io_size, ==, zio->io_lsize); 1528 zio->io_orig_size = zio->io_size = zio->io_lsize = size; 1529 } 1530 } 1531 1532 /* 1533 * ========================================================================== 1534 * Prepare to read and write logical blocks 1535 * ========================================================================== 1536 */ 1537 1538 static zio_t * 1539 zio_read_bp_init(zio_t *zio) 1540 { 1541 blkptr_t *bp = zio->io_bp; 1542 uint64_t psize = 1543 BP_IS_EMBEDDED(bp) ? BPE_GET_PSIZE(bp) : BP_GET_PSIZE(bp); 1544 1545 ASSERT3P(zio->io_bp, ==, &zio->io_bp_copy); 1546 1547 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF && 1548 zio->io_child_type == ZIO_CHILD_LOGICAL && 1549 !(zio->io_flags & ZIO_FLAG_RAW_COMPRESS)) { 1550 zio_push_transform(zio, abd_alloc_sametype(zio->io_abd, psize), 1551 psize, psize, zio_decompress); 1552 } 1553 1554 if (((BP_IS_PROTECTED(bp) && !(zio->io_flags & ZIO_FLAG_RAW_ENCRYPT)) || 1555 BP_HAS_INDIRECT_MAC_CKSUM(bp)) && 1556 zio->io_child_type == ZIO_CHILD_LOGICAL) { 1557 zio_push_transform(zio, abd_alloc_sametype(zio->io_abd, psize), 1558 psize, psize, zio_decrypt); 1559 } 1560 1561 if (BP_IS_EMBEDDED(bp) && BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA) { 1562 int psize = BPE_GET_PSIZE(bp); 1563 void *data = abd_borrow_buf(zio->io_abd, psize); 1564 1565 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1566 decode_embedded_bp_compressed(bp, data); 1567 abd_return_buf_copy(zio->io_abd, data, psize); 1568 } else { 1569 ASSERT(!BP_IS_EMBEDDED(bp)); 1570 ASSERT3P(zio->io_bp, ==, &zio->io_bp_copy); 1571 } 1572 1573 if (!DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) && BP_GET_LEVEL(bp) == 0) 1574 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 1575 1576 if (BP_GET_TYPE(bp) == DMU_OT_DDT_ZAP) 1577 zio->io_flags |= ZIO_FLAG_DONT_CACHE; 1578 1579 if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL) 1580 zio->io_pipeline = ZIO_DDT_READ_PIPELINE; 1581 1582 return (zio); 1583 } 1584 1585 static zio_t * 1586 zio_write_bp_init(zio_t *zio) 1587 { 1588 if (!IO_IS_ALLOCATING(zio)) 1589 return (zio); 1590 1591 ASSERT(zio->io_child_type != ZIO_CHILD_DDT); 1592 1593 if (zio->io_bp_override) { 1594 blkptr_t *bp = zio->io_bp; 1595 zio_prop_t *zp = &zio->io_prop; 1596 1597 ASSERT(bp->blk_birth != zio->io_txg); 1598 ASSERT(BP_GET_DEDUP(zio->io_bp_override) == 0); 1599 1600 *bp = *zio->io_bp_override; 1601 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1602 1603 if (BP_IS_EMBEDDED(bp)) 1604 return (zio); 1605 1606 /* 1607 * If we've been overridden and nopwrite is set then 1608 * set the flag accordingly to indicate that a nopwrite 1609 * has already occurred. 1610 */ 1611 if (!BP_IS_HOLE(bp) && zp->zp_nopwrite) { 1612 ASSERT(!zp->zp_dedup); 1613 ASSERT3U(BP_GET_CHECKSUM(bp), ==, zp->zp_checksum); 1614 zio->io_flags |= ZIO_FLAG_NOPWRITE; 1615 return (zio); 1616 } 1617 1618 ASSERT(!zp->zp_nopwrite); 1619 1620 if (BP_IS_HOLE(bp) || !zp->zp_dedup) 1621 return (zio); 1622 1623 ASSERT((zio_checksum_table[zp->zp_checksum].ci_flags & 1624 ZCHECKSUM_FLAG_DEDUP) || zp->zp_dedup_verify); 1625 1626 if (BP_GET_CHECKSUM(bp) == zp->zp_checksum && 1627 !zp->zp_encrypt) { 1628 BP_SET_DEDUP(bp, 1); 1629 zio->io_pipeline |= ZIO_STAGE_DDT_WRITE; 1630 return (zio); 1631 } 1632 1633 /* 1634 * We were unable to handle this as an override bp, treat 1635 * it as a regular write I/O. 1636 */ 1637 zio->io_bp_override = NULL; 1638 *bp = zio->io_bp_orig; 1639 zio->io_pipeline = zio->io_orig_pipeline; 1640 } 1641 1642 return (zio); 1643 } 1644 1645 static zio_t * 1646 zio_write_compress(zio_t *zio) 1647 { 1648 spa_t *spa = zio->io_spa; 1649 zio_prop_t *zp = &zio->io_prop; 1650 enum zio_compress compress = zp->zp_compress; 1651 blkptr_t *bp = zio->io_bp; 1652 uint64_t lsize = zio->io_lsize; 1653 uint64_t psize = zio->io_size; 1654 int pass = 1; 1655 1656 /* 1657 * If our children haven't all reached the ready stage, 1658 * wait for them and then repeat this pipeline stage. 1659 */ 1660 if (zio_wait_for_children(zio, ZIO_CHILD_LOGICAL_BIT | 1661 ZIO_CHILD_GANG_BIT, ZIO_WAIT_READY)) { 1662 return (NULL); 1663 } 1664 1665 if (!IO_IS_ALLOCATING(zio)) 1666 return (zio); 1667 1668 if (zio->io_children_ready != NULL) { 1669 /* 1670 * Now that all our children are ready, run the callback 1671 * associated with this zio in case it wants to modify the 1672 * data to be written. 1673 */ 1674 ASSERT3U(zp->zp_level, >, 0); 1675 zio->io_children_ready(zio); 1676 } 1677 1678 ASSERT(zio->io_child_type != ZIO_CHILD_DDT); 1679 ASSERT(zio->io_bp_override == NULL); 1680 1681 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg) { 1682 /* 1683 * We're rewriting an existing block, which means we're 1684 * working on behalf of spa_sync(). For spa_sync() to 1685 * converge, it must eventually be the case that we don't 1686 * have to allocate new blocks. But compression changes 1687 * the blocksize, which forces a reallocate, and makes 1688 * convergence take longer. Therefore, after the first 1689 * few passes, stop compressing to ensure convergence. 1690 */ 1691 pass = spa_sync_pass(spa); 1692 1693 ASSERT(zio->io_txg == spa_syncing_txg(spa)); 1694 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1695 ASSERT(!BP_GET_DEDUP(bp)); 1696 1697 if (pass >= zfs_sync_pass_dont_compress) 1698 compress = ZIO_COMPRESS_OFF; 1699 1700 /* Make sure someone doesn't change their mind on overwrites */ 1701 ASSERT(BP_IS_EMBEDDED(bp) || MIN(zp->zp_copies + BP_IS_GANG(bp), 1702 spa_max_replication(spa)) == BP_GET_NDVAS(bp)); 1703 } 1704 1705 /* If it's a compressed write that is not raw, compress the buffer. */ 1706 if (compress != ZIO_COMPRESS_OFF && 1707 !(zio->io_flags & ZIO_FLAG_RAW_COMPRESS)) { 1708 void *cbuf = zio_buf_alloc(lsize); 1709 psize = zio_compress_data(compress, zio->io_abd, cbuf, lsize, 1710 zp->zp_complevel); 1711 if (psize == 0 || psize >= lsize) { 1712 compress = ZIO_COMPRESS_OFF; 1713 zio_buf_free(cbuf, lsize); 1714 } else if (!zp->zp_dedup && !zp->zp_encrypt && 1715 psize <= BPE_PAYLOAD_SIZE && 1716 zp->zp_level == 0 && !DMU_OT_HAS_FILL(zp->zp_type) && 1717 spa_feature_is_enabled(spa, SPA_FEATURE_EMBEDDED_DATA)) { 1718 encode_embedded_bp_compressed(bp, 1719 cbuf, compress, lsize, psize); 1720 BPE_SET_ETYPE(bp, BP_EMBEDDED_TYPE_DATA); 1721 BP_SET_TYPE(bp, zio->io_prop.zp_type); 1722 BP_SET_LEVEL(bp, zio->io_prop.zp_level); 1723 zio_buf_free(cbuf, lsize); 1724 bp->blk_birth = zio->io_txg; 1725 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1726 ASSERT(spa_feature_is_active(spa, 1727 SPA_FEATURE_EMBEDDED_DATA)); 1728 return (zio); 1729 } else { 1730 /* 1731 * Round compressed size up to the minimum allocation 1732 * size of the smallest-ashift device, and zero the 1733 * tail. This ensures that the compressed size of the 1734 * BP (and thus compressratio property) are correct, 1735 * in that we charge for the padding used to fill out 1736 * the last sector. 1737 */ 1738 ASSERT3U(spa->spa_min_alloc, >=, SPA_MINBLOCKSHIFT); 1739 size_t rounded = (size_t)roundup(psize, 1740 spa->spa_min_alloc); 1741 if (rounded >= lsize) { 1742 compress = ZIO_COMPRESS_OFF; 1743 zio_buf_free(cbuf, lsize); 1744 psize = lsize; 1745 } else { 1746 abd_t *cdata = abd_get_from_buf(cbuf, lsize); 1747 abd_take_ownership_of_buf(cdata, B_TRUE); 1748 abd_zero_off(cdata, psize, rounded - psize); 1749 psize = rounded; 1750 zio_push_transform(zio, cdata, 1751 psize, lsize, NULL); 1752 } 1753 } 1754 1755 /* 1756 * We were unable to handle this as an override bp, treat 1757 * it as a regular write I/O. 1758 */ 1759 zio->io_bp_override = NULL; 1760 *bp = zio->io_bp_orig; 1761 zio->io_pipeline = zio->io_orig_pipeline; 1762 1763 } else if ((zio->io_flags & ZIO_FLAG_RAW_ENCRYPT) != 0 && 1764 zp->zp_type == DMU_OT_DNODE) { 1765 /* 1766 * The DMU actually relies on the zio layer's compression 1767 * to free metadnode blocks that have had all contained 1768 * dnodes freed. As a result, even when doing a raw 1769 * receive, we must check whether the block can be compressed 1770 * to a hole. 1771 */ 1772 psize = zio_compress_data(ZIO_COMPRESS_EMPTY, 1773 zio->io_abd, NULL, lsize, zp->zp_complevel); 1774 if (psize == 0 || psize >= lsize) 1775 compress = ZIO_COMPRESS_OFF; 1776 } else if (zio->io_flags & ZIO_FLAG_RAW_COMPRESS) { 1777 size_t rounded = MIN((size_t)roundup(psize, 1778 spa->spa_min_alloc), lsize); 1779 1780 if (rounded != psize) { 1781 abd_t *cdata = abd_alloc_linear(rounded, B_TRUE); 1782 abd_zero_off(cdata, psize, rounded - psize); 1783 abd_copy_off(cdata, zio->io_abd, 0, 0, psize); 1784 psize = rounded; 1785 zio_push_transform(zio, cdata, 1786 psize, rounded, NULL); 1787 } 1788 } else { 1789 ASSERT3U(psize, !=, 0); 1790 } 1791 1792 /* 1793 * The final pass of spa_sync() must be all rewrites, but the first 1794 * few passes offer a trade-off: allocating blocks defers convergence, 1795 * but newly allocated blocks are sequential, so they can be written 1796 * to disk faster. Therefore, we allow the first few passes of 1797 * spa_sync() to allocate new blocks, but force rewrites after that. 1798 * There should only be a handful of blocks after pass 1 in any case. 1799 */ 1800 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg && 1801 BP_GET_PSIZE(bp) == psize && 1802 pass >= zfs_sync_pass_rewrite) { 1803 VERIFY3U(psize, !=, 0); 1804 enum zio_stage gang_stages = zio->io_pipeline & ZIO_GANG_STAGES; 1805 1806 zio->io_pipeline = ZIO_REWRITE_PIPELINE | gang_stages; 1807 zio->io_flags |= ZIO_FLAG_IO_REWRITE; 1808 } else { 1809 BP_ZERO(bp); 1810 zio->io_pipeline = ZIO_WRITE_PIPELINE; 1811 } 1812 1813 if (psize == 0) { 1814 if (zio->io_bp_orig.blk_birth != 0 && 1815 spa_feature_is_active(spa, SPA_FEATURE_HOLE_BIRTH)) { 1816 BP_SET_LSIZE(bp, lsize); 1817 BP_SET_TYPE(bp, zp->zp_type); 1818 BP_SET_LEVEL(bp, zp->zp_level); 1819 BP_SET_BIRTH(bp, zio->io_txg, 0); 1820 } 1821 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 1822 } else { 1823 ASSERT(zp->zp_checksum != ZIO_CHECKSUM_GANG_HEADER); 1824 BP_SET_LSIZE(bp, lsize); 1825 BP_SET_TYPE(bp, zp->zp_type); 1826 BP_SET_LEVEL(bp, zp->zp_level); 1827 BP_SET_PSIZE(bp, psize); 1828 BP_SET_COMPRESS(bp, compress); 1829 BP_SET_CHECKSUM(bp, zp->zp_checksum); 1830 BP_SET_DEDUP(bp, zp->zp_dedup); 1831 BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER); 1832 if (zp->zp_dedup) { 1833 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1834 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1835 ASSERT(!zp->zp_encrypt || 1836 DMU_OT_IS_ENCRYPTED(zp->zp_type)); 1837 zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE; 1838 } 1839 if (zp->zp_nopwrite) { 1840 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 1841 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 1842 zio->io_pipeline |= ZIO_STAGE_NOP_WRITE; 1843 } 1844 } 1845 return (zio); 1846 } 1847 1848 static zio_t * 1849 zio_free_bp_init(zio_t *zio) 1850 { 1851 blkptr_t *bp = zio->io_bp; 1852 1853 if (zio->io_child_type == ZIO_CHILD_LOGICAL) { 1854 if (BP_GET_DEDUP(bp)) 1855 zio->io_pipeline = ZIO_DDT_FREE_PIPELINE; 1856 } 1857 1858 ASSERT3P(zio->io_bp, ==, &zio->io_bp_copy); 1859 1860 return (zio); 1861 } 1862 1863 /* 1864 * ========================================================================== 1865 * Execute the I/O pipeline 1866 * ========================================================================== 1867 */ 1868 1869 static void 1870 zio_taskq_dispatch(zio_t *zio, zio_taskq_type_t q, boolean_t cutinline) 1871 { 1872 spa_t *spa = zio->io_spa; 1873 zio_type_t t = zio->io_type; 1874 int flags = (cutinline ? TQ_FRONT : 0); 1875 1876 /* 1877 * If we're a config writer or a probe, the normal issue and 1878 * interrupt threads may all be blocked waiting for the config lock. 1879 * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL. 1880 */ 1881 if (zio->io_flags & (ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_PROBE)) 1882 t = ZIO_TYPE_NULL; 1883 1884 /* 1885 * A similar issue exists for the L2ARC write thread until L2ARC 2.0. 1886 */ 1887 if (t == ZIO_TYPE_WRITE && zio->io_vd && zio->io_vd->vdev_aux) 1888 t = ZIO_TYPE_NULL; 1889 1890 /* 1891 * If this is a high priority I/O, then use the high priority taskq if 1892 * available. 1893 */ 1894 if ((zio->io_priority == ZIO_PRIORITY_NOW || 1895 zio->io_priority == ZIO_PRIORITY_SYNC_WRITE) && 1896 spa->spa_zio_taskq[t][q + 1].stqs_count != 0) 1897 q++; 1898 1899 ASSERT3U(q, <, ZIO_TASKQ_TYPES); 1900 1901 /* 1902 * NB: We are assuming that the zio can only be dispatched 1903 * to a single taskq at a time. It would be a grievous error 1904 * to dispatch the zio to another taskq at the same time. 1905 */ 1906 ASSERT(taskq_empty_ent(&zio->io_tqent)); 1907 spa_taskq_dispatch_ent(spa, t, q, zio_execute, zio, flags, 1908 &zio->io_tqent); 1909 } 1910 1911 static boolean_t 1912 zio_taskq_member(zio_t *zio, zio_taskq_type_t q) 1913 { 1914 spa_t *spa = zio->io_spa; 1915 1916 taskq_t *tq = taskq_of_curthread(); 1917 1918 for (zio_type_t t = 0; t < ZIO_TYPES; t++) { 1919 spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q]; 1920 uint_t i; 1921 for (i = 0; i < tqs->stqs_count; i++) { 1922 if (tqs->stqs_taskq[i] == tq) 1923 return (B_TRUE); 1924 } 1925 } 1926 1927 return (B_FALSE); 1928 } 1929 1930 static zio_t * 1931 zio_issue_async(zio_t *zio) 1932 { 1933 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 1934 1935 return (NULL); 1936 } 1937 1938 void 1939 zio_interrupt(void *zio) 1940 { 1941 zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE); 1942 } 1943 1944 void 1945 zio_delay_interrupt(zio_t *zio) 1946 { 1947 /* 1948 * The timeout_generic() function isn't defined in userspace, so 1949 * rather than trying to implement the function, the zio delay 1950 * functionality has been disabled for userspace builds. 1951 */ 1952 1953 #ifdef _KERNEL 1954 /* 1955 * If io_target_timestamp is zero, then no delay has been registered 1956 * for this IO, thus jump to the end of this function and "skip" the 1957 * delay; issuing it directly to the zio layer. 1958 */ 1959 if (zio->io_target_timestamp != 0) { 1960 hrtime_t now = gethrtime(); 1961 1962 if (now >= zio->io_target_timestamp) { 1963 /* 1964 * This IO has already taken longer than the target 1965 * delay to complete, so we don't want to delay it 1966 * any longer; we "miss" the delay and issue it 1967 * directly to the zio layer. This is likely due to 1968 * the target latency being set to a value less than 1969 * the underlying hardware can satisfy (e.g. delay 1970 * set to 1ms, but the disks take 10ms to complete an 1971 * IO request). 1972 */ 1973 1974 DTRACE_PROBE2(zio__delay__miss, zio_t *, zio, 1975 hrtime_t, now); 1976 1977 zio_interrupt(zio); 1978 } else { 1979 taskqid_t tid; 1980 hrtime_t diff = zio->io_target_timestamp - now; 1981 clock_t expire_at_tick = ddi_get_lbolt() + 1982 NSEC_TO_TICK(diff); 1983 1984 DTRACE_PROBE3(zio__delay__hit, zio_t *, zio, 1985 hrtime_t, now, hrtime_t, diff); 1986 1987 if (NSEC_TO_TICK(diff) == 0) { 1988 /* Our delay is less than a jiffy - just spin */ 1989 zfs_sleep_until(zio->io_target_timestamp); 1990 zio_interrupt(zio); 1991 } else { 1992 /* 1993 * Use taskq_dispatch_delay() in the place of 1994 * OpenZFS's timeout_generic(). 1995 */ 1996 tid = taskq_dispatch_delay(system_taskq, 1997 zio_interrupt, zio, TQ_NOSLEEP, 1998 expire_at_tick); 1999 if (tid == TASKQID_INVALID) { 2000 /* 2001 * Couldn't allocate a task. Just 2002 * finish the zio without a delay. 2003 */ 2004 zio_interrupt(zio); 2005 } 2006 } 2007 } 2008 return; 2009 } 2010 #endif 2011 DTRACE_PROBE1(zio__delay__skip, zio_t *, zio); 2012 zio_interrupt(zio); 2013 } 2014 2015 static void 2016 zio_deadman_impl(zio_t *pio, int ziodepth) 2017 { 2018 zio_t *cio, *cio_next; 2019 zio_link_t *zl = NULL; 2020 vdev_t *vd = pio->io_vd; 2021 2022 if (zio_deadman_log_all || (vd != NULL && vd->vdev_ops->vdev_op_leaf)) { 2023 vdev_queue_t *vq = vd ? &vd->vdev_queue : NULL; 2024 zbookmark_phys_t *zb = &pio->io_bookmark; 2025 uint64_t delta = gethrtime() - pio->io_timestamp; 2026 uint64_t failmode = spa_get_deadman_failmode(pio->io_spa); 2027 2028 zfs_dbgmsg("slow zio[%d]: zio=%px timestamp=%llu " 2029 "delta=%llu queued=%llu io=%llu " 2030 "path=%s " 2031 "last=%llu type=%d " 2032 "priority=%d flags=0x%x stage=0x%x " 2033 "pipeline=0x%x pipeline-trace=0x%x " 2034 "objset=%llu object=%llu " 2035 "level=%llu blkid=%llu " 2036 "offset=%llu size=%llu " 2037 "error=%d", 2038 ziodepth, pio, pio->io_timestamp, 2039 (u_longlong_t)delta, pio->io_delta, pio->io_delay, 2040 vd ? vd->vdev_path : "NULL", 2041 vq ? vq->vq_io_complete_ts : 0, pio->io_type, 2042 pio->io_priority, pio->io_flags, pio->io_stage, 2043 pio->io_pipeline, pio->io_pipeline_trace, 2044 (u_longlong_t)zb->zb_objset, (u_longlong_t)zb->zb_object, 2045 (u_longlong_t)zb->zb_level, (u_longlong_t)zb->zb_blkid, 2046 (u_longlong_t)pio->io_offset, (u_longlong_t)pio->io_size, 2047 pio->io_error); 2048 (void) zfs_ereport_post(FM_EREPORT_ZFS_DEADMAN, 2049 pio->io_spa, vd, zb, pio, 0); 2050 2051 if (failmode == ZIO_FAILURE_MODE_CONTINUE && 2052 taskq_empty_ent(&pio->io_tqent)) { 2053 zio_interrupt(pio); 2054 } 2055 } 2056 2057 mutex_enter(&pio->io_lock); 2058 for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) { 2059 cio_next = zio_walk_children(pio, &zl); 2060 zio_deadman_impl(cio, ziodepth + 1); 2061 } 2062 mutex_exit(&pio->io_lock); 2063 } 2064 2065 /* 2066 * Log the critical information describing this zio and all of its children 2067 * using the zfs_dbgmsg() interface then post deadman event for the ZED. 2068 */ 2069 void 2070 zio_deadman(zio_t *pio, char *tag) 2071 { 2072 spa_t *spa = pio->io_spa; 2073 char *name = spa_name(spa); 2074 2075 if (!zfs_deadman_enabled || spa_suspended(spa)) 2076 return; 2077 2078 zio_deadman_impl(pio, 0); 2079 2080 switch (spa_get_deadman_failmode(spa)) { 2081 case ZIO_FAILURE_MODE_WAIT: 2082 zfs_dbgmsg("%s waiting for hung I/O to pool '%s'", tag, name); 2083 break; 2084 2085 case ZIO_FAILURE_MODE_CONTINUE: 2086 zfs_dbgmsg("%s restarting hung I/O for pool '%s'", tag, name); 2087 break; 2088 2089 case ZIO_FAILURE_MODE_PANIC: 2090 fm_panic("%s determined I/O to pool '%s' is hung.", tag, name); 2091 break; 2092 } 2093 } 2094 2095 /* 2096 * Execute the I/O pipeline until one of the following occurs: 2097 * (1) the I/O completes; (2) the pipeline stalls waiting for 2098 * dependent child I/Os; (3) the I/O issues, so we're waiting 2099 * for an I/O completion interrupt; (4) the I/O is delegated by 2100 * vdev-level caching or aggregation; (5) the I/O is deferred 2101 * due to vdev-level queueing; (6) the I/O is handed off to 2102 * another thread. In all cases, the pipeline stops whenever 2103 * there's no CPU work; it never burns a thread in cv_wait_io(). 2104 * 2105 * There's no locking on io_stage because there's no legitimate way 2106 * for multiple threads to be attempting to process the same I/O. 2107 */ 2108 static zio_pipe_stage_t *zio_pipeline[]; 2109 2110 /* 2111 * zio_execute() is a wrapper around the static function 2112 * __zio_execute() so that we can force __zio_execute() to be 2113 * inlined. This reduces stack overhead which is important 2114 * because __zio_execute() is called recursively in several zio 2115 * code paths. zio_execute() itself cannot be inlined because 2116 * it is externally visible. 2117 */ 2118 void 2119 zio_execute(void *zio) 2120 { 2121 fstrans_cookie_t cookie; 2122 2123 cookie = spl_fstrans_mark(); 2124 __zio_execute(zio); 2125 spl_fstrans_unmark(cookie); 2126 } 2127 2128 /* 2129 * Used to determine if in the current context the stack is sized large 2130 * enough to allow zio_execute() to be called recursively. A minimum 2131 * stack size of 16K is required to avoid needing to re-dispatch the zio. 2132 */ 2133 static boolean_t 2134 zio_execute_stack_check(zio_t *zio) 2135 { 2136 #if !defined(HAVE_LARGE_STACKS) 2137 dsl_pool_t *dp = spa_get_dsl(zio->io_spa); 2138 2139 /* Executing in txg_sync_thread() context. */ 2140 if (dp && curthread == dp->dp_tx.tx_sync_thread) 2141 return (B_TRUE); 2142 2143 /* Pool initialization outside of zio_taskq context. */ 2144 if (dp && spa_is_initializing(dp->dp_spa) && 2145 !zio_taskq_member(zio, ZIO_TASKQ_ISSUE) && 2146 !zio_taskq_member(zio, ZIO_TASKQ_ISSUE_HIGH)) 2147 return (B_TRUE); 2148 #else 2149 (void) zio; 2150 #endif /* HAVE_LARGE_STACKS */ 2151 2152 return (B_FALSE); 2153 } 2154 2155 __attribute__((always_inline)) 2156 static inline void 2157 __zio_execute(zio_t *zio) 2158 { 2159 ASSERT3U(zio->io_queued_timestamp, >, 0); 2160 2161 while (zio->io_stage < ZIO_STAGE_DONE) { 2162 enum zio_stage pipeline = zio->io_pipeline; 2163 enum zio_stage stage = zio->io_stage; 2164 2165 zio->io_executor = curthread; 2166 2167 ASSERT(!MUTEX_HELD(&zio->io_lock)); 2168 ASSERT(ISP2(stage)); 2169 ASSERT(zio->io_stall == NULL); 2170 2171 do { 2172 stage <<= 1; 2173 } while ((stage & pipeline) == 0); 2174 2175 ASSERT(stage <= ZIO_STAGE_DONE); 2176 2177 /* 2178 * If we are in interrupt context and this pipeline stage 2179 * will grab a config lock that is held across I/O, 2180 * or may wait for an I/O that needs an interrupt thread 2181 * to complete, issue async to avoid deadlock. 2182 * 2183 * For VDEV_IO_START, we cut in line so that the io will 2184 * be sent to disk promptly. 2185 */ 2186 if ((stage & ZIO_BLOCKING_STAGES) && zio->io_vd == NULL && 2187 zio_taskq_member(zio, ZIO_TASKQ_INTERRUPT)) { 2188 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ? 2189 zio_requeue_io_start_cut_in_line : B_FALSE; 2190 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut); 2191 return; 2192 } 2193 2194 /* 2195 * If the current context doesn't have large enough stacks 2196 * the zio must be issued asynchronously to prevent overflow. 2197 */ 2198 if (zio_execute_stack_check(zio)) { 2199 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ? 2200 zio_requeue_io_start_cut_in_line : B_FALSE; 2201 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut); 2202 return; 2203 } 2204 2205 zio->io_stage = stage; 2206 zio->io_pipeline_trace |= zio->io_stage; 2207 2208 /* 2209 * The zio pipeline stage returns the next zio to execute 2210 * (typically the same as this one), or NULL if we should 2211 * stop. 2212 */ 2213 zio = zio_pipeline[highbit64(stage) - 1](zio); 2214 2215 if (zio == NULL) 2216 return; 2217 } 2218 } 2219 2220 2221 /* 2222 * ========================================================================== 2223 * Initiate I/O, either sync or async 2224 * ========================================================================== 2225 */ 2226 int 2227 zio_wait(zio_t *zio) 2228 { 2229 /* 2230 * Some routines, like zio_free_sync(), may return a NULL zio 2231 * to avoid the performance overhead of creating and then destroying 2232 * an unneeded zio. For the callers' simplicity, we accept a NULL 2233 * zio and ignore it. 2234 */ 2235 if (zio == NULL) 2236 return (0); 2237 2238 long timeout = MSEC_TO_TICK(zfs_deadman_ziotime_ms); 2239 int error; 2240 2241 ASSERT3S(zio->io_stage, ==, ZIO_STAGE_OPEN); 2242 ASSERT3P(zio->io_executor, ==, NULL); 2243 2244 zio->io_waiter = curthread; 2245 ASSERT0(zio->io_queued_timestamp); 2246 zio->io_queued_timestamp = gethrtime(); 2247 2248 __zio_execute(zio); 2249 2250 mutex_enter(&zio->io_lock); 2251 while (zio->io_executor != NULL) { 2252 error = cv_timedwait_io(&zio->io_cv, &zio->io_lock, 2253 ddi_get_lbolt() + timeout); 2254 2255 if (zfs_deadman_enabled && error == -1 && 2256 gethrtime() - zio->io_queued_timestamp > 2257 spa_deadman_ziotime(zio->io_spa)) { 2258 mutex_exit(&zio->io_lock); 2259 timeout = MSEC_TO_TICK(zfs_deadman_checktime_ms); 2260 zio_deadman(zio, FTAG); 2261 mutex_enter(&zio->io_lock); 2262 } 2263 } 2264 mutex_exit(&zio->io_lock); 2265 2266 error = zio->io_error; 2267 zio_destroy(zio); 2268 2269 return (error); 2270 } 2271 2272 void 2273 zio_nowait(zio_t *zio) 2274 { 2275 /* 2276 * See comment in zio_wait(). 2277 */ 2278 if (zio == NULL) 2279 return; 2280 2281 ASSERT3P(zio->io_executor, ==, NULL); 2282 2283 if (zio->io_child_type == ZIO_CHILD_LOGICAL && 2284 zio_unique_parent(zio) == NULL) { 2285 zio_t *pio; 2286 2287 /* 2288 * This is a logical async I/O with no parent to wait for it. 2289 * We add it to the spa_async_root_zio "Godfather" I/O which 2290 * will ensure they complete prior to unloading the pool. 2291 */ 2292 spa_t *spa = zio->io_spa; 2293 pio = spa->spa_async_zio_root[CPU_SEQID_UNSTABLE]; 2294 2295 zio_add_child(pio, zio); 2296 } 2297 2298 ASSERT0(zio->io_queued_timestamp); 2299 zio->io_queued_timestamp = gethrtime(); 2300 __zio_execute(zio); 2301 } 2302 2303 /* 2304 * ========================================================================== 2305 * Reexecute, cancel, or suspend/resume failed I/O 2306 * ========================================================================== 2307 */ 2308 2309 static void 2310 zio_reexecute(void *arg) 2311 { 2312 zio_t *pio = arg; 2313 zio_t *cio, *cio_next; 2314 2315 ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL); 2316 ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN); 2317 ASSERT(pio->io_gang_leader == NULL); 2318 ASSERT(pio->io_gang_tree == NULL); 2319 2320 pio->io_flags = pio->io_orig_flags; 2321 pio->io_stage = pio->io_orig_stage; 2322 pio->io_pipeline = pio->io_orig_pipeline; 2323 pio->io_reexecute = 0; 2324 pio->io_flags |= ZIO_FLAG_REEXECUTED; 2325 pio->io_pipeline_trace = 0; 2326 pio->io_error = 0; 2327 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 2328 pio->io_state[w] = 0; 2329 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 2330 pio->io_child_error[c] = 0; 2331 2332 if (IO_IS_ALLOCATING(pio)) 2333 BP_ZERO(pio->io_bp); 2334 2335 /* 2336 * As we reexecute pio's children, new children could be created. 2337 * New children go to the head of pio's io_child_list, however, 2338 * so we will (correctly) not reexecute them. The key is that 2339 * the remainder of pio's io_child_list, from 'cio_next' onward, 2340 * cannot be affected by any side effects of reexecuting 'cio'. 2341 */ 2342 zio_link_t *zl = NULL; 2343 mutex_enter(&pio->io_lock); 2344 for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) { 2345 cio_next = zio_walk_children(pio, &zl); 2346 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 2347 pio->io_children[cio->io_child_type][w]++; 2348 mutex_exit(&pio->io_lock); 2349 zio_reexecute(cio); 2350 mutex_enter(&pio->io_lock); 2351 } 2352 mutex_exit(&pio->io_lock); 2353 2354 /* 2355 * Now that all children have been reexecuted, execute the parent. 2356 * We don't reexecute "The Godfather" I/O here as it's the 2357 * responsibility of the caller to wait on it. 2358 */ 2359 if (!(pio->io_flags & ZIO_FLAG_GODFATHER)) { 2360 pio->io_queued_timestamp = gethrtime(); 2361 __zio_execute(pio); 2362 } 2363 } 2364 2365 void 2366 zio_suspend(spa_t *spa, zio_t *zio, zio_suspend_reason_t reason) 2367 { 2368 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC) 2369 fm_panic("Pool '%s' has encountered an uncorrectable I/O " 2370 "failure and the failure mode property for this pool " 2371 "is set to panic.", spa_name(spa)); 2372 2373 cmn_err(CE_WARN, "Pool '%s' has encountered an uncorrectable I/O " 2374 "failure and has been suspended.\n", spa_name(spa)); 2375 2376 (void) zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL, 2377 NULL, NULL, 0); 2378 2379 mutex_enter(&spa->spa_suspend_lock); 2380 2381 if (spa->spa_suspend_zio_root == NULL) 2382 spa->spa_suspend_zio_root = zio_root(spa, NULL, NULL, 2383 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | 2384 ZIO_FLAG_GODFATHER); 2385 2386 spa->spa_suspended = reason; 2387 2388 if (zio != NULL) { 2389 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 2390 ASSERT(zio != spa->spa_suspend_zio_root); 2391 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 2392 ASSERT(zio_unique_parent(zio) == NULL); 2393 ASSERT(zio->io_stage == ZIO_STAGE_DONE); 2394 zio_add_child(spa->spa_suspend_zio_root, zio); 2395 } 2396 2397 mutex_exit(&spa->spa_suspend_lock); 2398 } 2399 2400 int 2401 zio_resume(spa_t *spa) 2402 { 2403 zio_t *pio; 2404 2405 /* 2406 * Reexecute all previously suspended i/o. 2407 */ 2408 mutex_enter(&spa->spa_suspend_lock); 2409 spa->spa_suspended = ZIO_SUSPEND_NONE; 2410 cv_broadcast(&spa->spa_suspend_cv); 2411 pio = spa->spa_suspend_zio_root; 2412 spa->spa_suspend_zio_root = NULL; 2413 mutex_exit(&spa->spa_suspend_lock); 2414 2415 if (pio == NULL) 2416 return (0); 2417 2418 zio_reexecute(pio); 2419 return (zio_wait(pio)); 2420 } 2421 2422 void 2423 zio_resume_wait(spa_t *spa) 2424 { 2425 mutex_enter(&spa->spa_suspend_lock); 2426 while (spa_suspended(spa)) 2427 cv_wait(&spa->spa_suspend_cv, &spa->spa_suspend_lock); 2428 mutex_exit(&spa->spa_suspend_lock); 2429 } 2430 2431 /* 2432 * ========================================================================== 2433 * Gang blocks. 2434 * 2435 * A gang block is a collection of small blocks that looks to the DMU 2436 * like one large block. When zio_dva_allocate() cannot find a block 2437 * of the requested size, due to either severe fragmentation or the pool 2438 * being nearly full, it calls zio_write_gang_block() to construct the 2439 * block from smaller fragments. 2440 * 2441 * A gang block consists of a gang header (zio_gbh_phys_t) and up to 2442 * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like 2443 * an indirect block: it's an array of block pointers. It consumes 2444 * only one sector and hence is allocatable regardless of fragmentation. 2445 * The gang header's bps point to its gang members, which hold the data. 2446 * 2447 * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg> 2448 * as the verifier to ensure uniqueness of the SHA256 checksum. 2449 * Critically, the gang block bp's blk_cksum is the checksum of the data, 2450 * not the gang header. This ensures that data block signatures (needed for 2451 * deduplication) are independent of how the block is physically stored. 2452 * 2453 * Gang blocks can be nested: a gang member may itself be a gang block. 2454 * Thus every gang block is a tree in which root and all interior nodes are 2455 * gang headers, and the leaves are normal blocks that contain user data. 2456 * The root of the gang tree is called the gang leader. 2457 * 2458 * To perform any operation (read, rewrite, free, claim) on a gang block, 2459 * zio_gang_assemble() first assembles the gang tree (minus data leaves) 2460 * in the io_gang_tree field of the original logical i/o by recursively 2461 * reading the gang leader and all gang headers below it. This yields 2462 * an in-core tree containing the contents of every gang header and the 2463 * bps for every constituent of the gang block. 2464 * 2465 * With the gang tree now assembled, zio_gang_issue() just walks the gang tree 2466 * and invokes a callback on each bp. To free a gang block, zio_gang_issue() 2467 * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp. 2468 * zio_claim_gang() provides a similarly trivial wrapper for zio_claim(). 2469 * zio_read_gang() is a wrapper around zio_read() that omits reading gang 2470 * headers, since we already have those in io_gang_tree. zio_rewrite_gang() 2471 * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite() 2472 * of the gang header plus zio_checksum_compute() of the data to update the 2473 * gang header's blk_cksum as described above. 2474 * 2475 * The two-phase assemble/issue model solves the problem of partial failure -- 2476 * what if you'd freed part of a gang block but then couldn't read the 2477 * gang header for another part? Assembling the entire gang tree first 2478 * ensures that all the necessary gang header I/O has succeeded before 2479 * starting the actual work of free, claim, or write. Once the gang tree 2480 * is assembled, free and claim are in-memory operations that cannot fail. 2481 * 2482 * In the event that a gang write fails, zio_dva_unallocate() walks the 2483 * gang tree to immediately free (i.e. insert back into the space map) 2484 * everything we've allocated. This ensures that we don't get ENOSPC 2485 * errors during repeated suspend/resume cycles due to a flaky device. 2486 * 2487 * Gang rewrites only happen during sync-to-convergence. If we can't assemble 2488 * the gang tree, we won't modify the block, so we can safely defer the free 2489 * (knowing that the block is still intact). If we *can* assemble the gang 2490 * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free 2491 * each constituent bp and we can allocate a new block on the next sync pass. 2492 * 2493 * In all cases, the gang tree allows complete recovery from partial failure. 2494 * ========================================================================== 2495 */ 2496 2497 static void 2498 zio_gang_issue_func_done(zio_t *zio) 2499 { 2500 abd_free(zio->io_abd); 2501 } 2502 2503 static zio_t * 2504 zio_read_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data, 2505 uint64_t offset) 2506 { 2507 if (gn != NULL) 2508 return (pio); 2509 2510 return (zio_read(pio, pio->io_spa, bp, abd_get_offset(data, offset), 2511 BP_GET_PSIZE(bp), zio_gang_issue_func_done, 2512 NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 2513 &pio->io_bookmark)); 2514 } 2515 2516 static zio_t * 2517 zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data, 2518 uint64_t offset) 2519 { 2520 zio_t *zio; 2521 2522 if (gn != NULL) { 2523 abd_t *gbh_abd = 2524 abd_get_from_buf(gn->gn_gbh, SPA_GANGBLOCKSIZE); 2525 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 2526 gbh_abd, SPA_GANGBLOCKSIZE, zio_gang_issue_func_done, NULL, 2527 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio), 2528 &pio->io_bookmark); 2529 /* 2530 * As we rewrite each gang header, the pipeline will compute 2531 * a new gang block header checksum for it; but no one will 2532 * compute a new data checksum, so we do that here. The one 2533 * exception is the gang leader: the pipeline already computed 2534 * its data checksum because that stage precedes gang assembly. 2535 * (Presently, nothing actually uses interior data checksums; 2536 * this is just good hygiene.) 2537 */ 2538 if (gn != pio->io_gang_leader->io_gang_tree) { 2539 abd_t *buf = abd_get_offset(data, offset); 2540 2541 zio_checksum_compute(zio, BP_GET_CHECKSUM(bp), 2542 buf, BP_GET_PSIZE(bp)); 2543 2544 abd_free(buf); 2545 } 2546 /* 2547 * If we are here to damage data for testing purposes, 2548 * leave the GBH alone so that we can detect the damage. 2549 */ 2550 if (pio->io_gang_leader->io_flags & ZIO_FLAG_INDUCE_DAMAGE) 2551 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 2552 } else { 2553 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp, 2554 abd_get_offset(data, offset), BP_GET_PSIZE(bp), 2555 zio_gang_issue_func_done, NULL, pio->io_priority, 2556 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 2557 } 2558 2559 return (zio); 2560 } 2561 2562 static zio_t * 2563 zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data, 2564 uint64_t offset) 2565 { 2566 (void) gn, (void) data, (void) offset; 2567 2568 zio_t *zio = zio_free_sync(pio, pio->io_spa, pio->io_txg, bp, 2569 ZIO_GANG_CHILD_FLAGS(pio)); 2570 if (zio == NULL) { 2571 zio = zio_null(pio, pio->io_spa, 2572 NULL, NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio)); 2573 } 2574 return (zio); 2575 } 2576 2577 static zio_t * 2578 zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data, 2579 uint64_t offset) 2580 { 2581 (void) gn, (void) data, (void) offset; 2582 return (zio_claim(pio, pio->io_spa, pio->io_txg, bp, 2583 NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio))); 2584 } 2585 2586 static zio_gang_issue_func_t *zio_gang_issue_func[ZIO_TYPES] = { 2587 NULL, 2588 zio_read_gang, 2589 zio_rewrite_gang, 2590 zio_free_gang, 2591 zio_claim_gang, 2592 NULL 2593 }; 2594 2595 static void zio_gang_tree_assemble_done(zio_t *zio); 2596 2597 static zio_gang_node_t * 2598 zio_gang_node_alloc(zio_gang_node_t **gnpp) 2599 { 2600 zio_gang_node_t *gn; 2601 2602 ASSERT(*gnpp == NULL); 2603 2604 gn = kmem_zalloc(sizeof (*gn), KM_SLEEP); 2605 gn->gn_gbh = zio_buf_alloc(SPA_GANGBLOCKSIZE); 2606 *gnpp = gn; 2607 2608 return (gn); 2609 } 2610 2611 static void 2612 zio_gang_node_free(zio_gang_node_t **gnpp) 2613 { 2614 zio_gang_node_t *gn = *gnpp; 2615 2616 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 2617 ASSERT(gn->gn_child[g] == NULL); 2618 2619 zio_buf_free(gn->gn_gbh, SPA_GANGBLOCKSIZE); 2620 kmem_free(gn, sizeof (*gn)); 2621 *gnpp = NULL; 2622 } 2623 2624 static void 2625 zio_gang_tree_free(zio_gang_node_t **gnpp) 2626 { 2627 zio_gang_node_t *gn = *gnpp; 2628 2629 if (gn == NULL) 2630 return; 2631 2632 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) 2633 zio_gang_tree_free(&gn->gn_child[g]); 2634 2635 zio_gang_node_free(gnpp); 2636 } 2637 2638 static void 2639 zio_gang_tree_assemble(zio_t *gio, blkptr_t *bp, zio_gang_node_t **gnpp) 2640 { 2641 zio_gang_node_t *gn = zio_gang_node_alloc(gnpp); 2642 abd_t *gbh_abd = abd_get_from_buf(gn->gn_gbh, SPA_GANGBLOCKSIZE); 2643 2644 ASSERT(gio->io_gang_leader == gio); 2645 ASSERT(BP_IS_GANG(bp)); 2646 2647 zio_nowait(zio_read(gio, gio->io_spa, bp, gbh_abd, SPA_GANGBLOCKSIZE, 2648 zio_gang_tree_assemble_done, gn, gio->io_priority, 2649 ZIO_GANG_CHILD_FLAGS(gio), &gio->io_bookmark)); 2650 } 2651 2652 static void 2653 zio_gang_tree_assemble_done(zio_t *zio) 2654 { 2655 zio_t *gio = zio->io_gang_leader; 2656 zio_gang_node_t *gn = zio->io_private; 2657 blkptr_t *bp = zio->io_bp; 2658 2659 ASSERT(gio == zio_unique_parent(zio)); 2660 ASSERT(zio->io_child_count == 0); 2661 2662 if (zio->io_error) 2663 return; 2664 2665 /* this ABD was created from a linear buf in zio_gang_tree_assemble */ 2666 if (BP_SHOULD_BYTESWAP(bp)) 2667 byteswap_uint64_array(abd_to_buf(zio->io_abd), zio->io_size); 2668 2669 ASSERT3P(abd_to_buf(zio->io_abd), ==, gn->gn_gbh); 2670 ASSERT(zio->io_size == SPA_GANGBLOCKSIZE); 2671 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 2672 2673 abd_free(zio->io_abd); 2674 2675 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 2676 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 2677 if (!BP_IS_GANG(gbp)) 2678 continue; 2679 zio_gang_tree_assemble(gio, gbp, &gn->gn_child[g]); 2680 } 2681 } 2682 2683 static void 2684 zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, abd_t *data, 2685 uint64_t offset) 2686 { 2687 zio_t *gio = pio->io_gang_leader; 2688 zio_t *zio; 2689 2690 ASSERT(BP_IS_GANG(bp) == !!gn); 2691 ASSERT(BP_GET_CHECKSUM(bp) == BP_GET_CHECKSUM(gio->io_bp)); 2692 ASSERT(BP_GET_LSIZE(bp) == BP_GET_PSIZE(bp) || gn == gio->io_gang_tree); 2693 2694 /* 2695 * If you're a gang header, your data is in gn->gn_gbh. 2696 * If you're a gang member, your data is in 'data' and gn == NULL. 2697 */ 2698 zio = zio_gang_issue_func[gio->io_type](pio, bp, gn, data, offset); 2699 2700 if (gn != NULL) { 2701 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC); 2702 2703 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 2704 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g]; 2705 if (BP_IS_HOLE(gbp)) 2706 continue; 2707 zio_gang_tree_issue(zio, gn->gn_child[g], gbp, data, 2708 offset); 2709 offset += BP_GET_PSIZE(gbp); 2710 } 2711 } 2712 2713 if (gn == gio->io_gang_tree) 2714 ASSERT3U(gio->io_size, ==, offset); 2715 2716 if (zio != pio) 2717 zio_nowait(zio); 2718 } 2719 2720 static zio_t * 2721 zio_gang_assemble(zio_t *zio) 2722 { 2723 blkptr_t *bp = zio->io_bp; 2724 2725 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == NULL); 2726 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2727 2728 zio->io_gang_leader = zio; 2729 2730 zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree); 2731 2732 return (zio); 2733 } 2734 2735 static zio_t * 2736 zio_gang_issue(zio_t *zio) 2737 { 2738 blkptr_t *bp = zio->io_bp; 2739 2740 if (zio_wait_for_children(zio, ZIO_CHILD_GANG_BIT, ZIO_WAIT_DONE)) { 2741 return (NULL); 2742 } 2743 2744 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio); 2745 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 2746 2747 if (zio->io_child_error[ZIO_CHILD_GANG] == 0) 2748 zio_gang_tree_issue(zio, zio->io_gang_tree, bp, zio->io_abd, 2749 0); 2750 else 2751 zio_gang_tree_free(&zio->io_gang_tree); 2752 2753 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2754 2755 return (zio); 2756 } 2757 2758 static void 2759 zio_write_gang_member_ready(zio_t *zio) 2760 { 2761 zio_t *pio = zio_unique_parent(zio); 2762 dva_t *cdva = zio->io_bp->blk_dva; 2763 dva_t *pdva = pio->io_bp->blk_dva; 2764 uint64_t asize; 2765 zio_t *gio __maybe_unused = zio->io_gang_leader; 2766 2767 if (BP_IS_HOLE(zio->io_bp)) 2768 return; 2769 2770 ASSERT(BP_IS_HOLE(&zio->io_bp_orig)); 2771 2772 ASSERT(zio->io_child_type == ZIO_CHILD_GANG); 2773 ASSERT3U(zio->io_prop.zp_copies, ==, gio->io_prop.zp_copies); 2774 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp)); 2775 ASSERT3U(pio->io_prop.zp_copies, <=, BP_GET_NDVAS(pio->io_bp)); 2776 ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp)); 2777 2778 mutex_enter(&pio->io_lock); 2779 for (int d = 0; d < BP_GET_NDVAS(zio->io_bp); d++) { 2780 ASSERT(DVA_GET_GANG(&pdva[d])); 2781 asize = DVA_GET_ASIZE(&pdva[d]); 2782 asize += DVA_GET_ASIZE(&cdva[d]); 2783 DVA_SET_ASIZE(&pdva[d], asize); 2784 } 2785 mutex_exit(&pio->io_lock); 2786 } 2787 2788 static void 2789 zio_write_gang_done(zio_t *zio) 2790 { 2791 /* 2792 * The io_abd field will be NULL for a zio with no data. The io_flags 2793 * will initially have the ZIO_FLAG_NODATA bit flag set, but we can't 2794 * check for it here as it is cleared in zio_ready. 2795 */ 2796 if (zio->io_abd != NULL) 2797 abd_free(zio->io_abd); 2798 } 2799 2800 static zio_t * 2801 zio_write_gang_block(zio_t *pio, metaslab_class_t *mc) 2802 { 2803 spa_t *spa = pio->io_spa; 2804 blkptr_t *bp = pio->io_bp; 2805 zio_t *gio = pio->io_gang_leader; 2806 zio_t *zio; 2807 zio_gang_node_t *gn, **gnpp; 2808 zio_gbh_phys_t *gbh; 2809 abd_t *gbh_abd; 2810 uint64_t txg = pio->io_txg; 2811 uint64_t resid = pio->io_size; 2812 uint64_t lsize; 2813 int copies = gio->io_prop.zp_copies; 2814 int gbh_copies; 2815 zio_prop_t zp; 2816 int error; 2817 boolean_t has_data = !(pio->io_flags & ZIO_FLAG_NODATA); 2818 2819 /* 2820 * encrypted blocks need DVA[2] free so encrypted gang headers can't 2821 * have a third copy. 2822 */ 2823 gbh_copies = MIN(copies + 1, spa_max_replication(spa)); 2824 if (gio->io_prop.zp_encrypt && gbh_copies >= SPA_DVAS_PER_BP) 2825 gbh_copies = SPA_DVAS_PER_BP - 1; 2826 2827 int flags = METASLAB_HINTBP_FAVOR | METASLAB_GANG_HEADER; 2828 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 2829 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 2830 ASSERT(has_data); 2831 2832 flags |= METASLAB_ASYNC_ALLOC; 2833 VERIFY(zfs_refcount_held(&mc->mc_allocator[pio->io_allocator]. 2834 mca_alloc_slots, pio)); 2835 2836 /* 2837 * The logical zio has already placed a reservation for 2838 * 'copies' allocation slots but gang blocks may require 2839 * additional copies. These additional copies 2840 * (i.e. gbh_copies - copies) are guaranteed to succeed 2841 * since metaslab_class_throttle_reserve() always allows 2842 * additional reservations for gang blocks. 2843 */ 2844 VERIFY(metaslab_class_throttle_reserve(mc, gbh_copies - copies, 2845 pio->io_allocator, pio, flags)); 2846 } 2847 2848 error = metaslab_alloc(spa, mc, SPA_GANGBLOCKSIZE, 2849 bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp, flags, 2850 &pio->io_alloc_list, pio, pio->io_allocator); 2851 if (error) { 2852 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 2853 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 2854 ASSERT(has_data); 2855 2856 /* 2857 * If we failed to allocate the gang block header then 2858 * we remove any additional allocation reservations that 2859 * we placed here. The original reservation will 2860 * be removed when the logical I/O goes to the ready 2861 * stage. 2862 */ 2863 metaslab_class_throttle_unreserve(mc, 2864 gbh_copies - copies, pio->io_allocator, pio); 2865 } 2866 2867 pio->io_error = error; 2868 return (pio); 2869 } 2870 2871 if (pio == gio) { 2872 gnpp = &gio->io_gang_tree; 2873 } else { 2874 gnpp = pio->io_private; 2875 ASSERT(pio->io_ready == zio_write_gang_member_ready); 2876 } 2877 2878 gn = zio_gang_node_alloc(gnpp); 2879 gbh = gn->gn_gbh; 2880 bzero(gbh, SPA_GANGBLOCKSIZE); 2881 gbh_abd = abd_get_from_buf(gbh, SPA_GANGBLOCKSIZE); 2882 2883 /* 2884 * Create the gang header. 2885 */ 2886 zio = zio_rewrite(pio, spa, txg, bp, gbh_abd, SPA_GANGBLOCKSIZE, 2887 zio_write_gang_done, NULL, pio->io_priority, 2888 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 2889 2890 /* 2891 * Create and nowait the gang children. 2892 */ 2893 for (int g = 0; resid != 0; resid -= lsize, g++) { 2894 lsize = P2ROUNDUP(resid / (SPA_GBH_NBLKPTRS - g), 2895 SPA_MINBLOCKSIZE); 2896 ASSERT(lsize >= SPA_MINBLOCKSIZE && lsize <= resid); 2897 2898 zp.zp_checksum = gio->io_prop.zp_checksum; 2899 zp.zp_compress = ZIO_COMPRESS_OFF; 2900 zp.zp_complevel = gio->io_prop.zp_complevel; 2901 zp.zp_type = DMU_OT_NONE; 2902 zp.zp_level = 0; 2903 zp.zp_copies = gio->io_prop.zp_copies; 2904 zp.zp_dedup = B_FALSE; 2905 zp.zp_dedup_verify = B_FALSE; 2906 zp.zp_nopwrite = B_FALSE; 2907 zp.zp_encrypt = gio->io_prop.zp_encrypt; 2908 zp.zp_byteorder = gio->io_prop.zp_byteorder; 2909 bzero(zp.zp_salt, ZIO_DATA_SALT_LEN); 2910 bzero(zp.zp_iv, ZIO_DATA_IV_LEN); 2911 bzero(zp.zp_mac, ZIO_DATA_MAC_LEN); 2912 2913 zio_t *cio = zio_write(zio, spa, txg, &gbh->zg_blkptr[g], 2914 has_data ? abd_get_offset(pio->io_abd, pio->io_size - 2915 resid) : NULL, lsize, lsize, &zp, 2916 zio_write_gang_member_ready, NULL, NULL, 2917 zio_write_gang_done, &gn->gn_child[g], pio->io_priority, 2918 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark); 2919 2920 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 2921 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 2922 ASSERT(has_data); 2923 2924 /* 2925 * Gang children won't throttle but we should 2926 * account for their work, so reserve an allocation 2927 * slot for them here. 2928 */ 2929 VERIFY(metaslab_class_throttle_reserve(mc, 2930 zp.zp_copies, cio->io_allocator, cio, flags)); 2931 } 2932 zio_nowait(cio); 2933 } 2934 2935 /* 2936 * Set pio's pipeline to just wait for zio to finish. 2937 */ 2938 pio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 2939 2940 /* 2941 * We didn't allocate this bp, so make sure it doesn't get unmarked. 2942 */ 2943 pio->io_flags &= ~ZIO_FLAG_FASTWRITE; 2944 2945 zio_nowait(zio); 2946 2947 return (pio); 2948 } 2949 2950 /* 2951 * The zio_nop_write stage in the pipeline determines if allocating a 2952 * new bp is necessary. The nopwrite feature can handle writes in 2953 * either syncing or open context (i.e. zil writes) and as a result is 2954 * mutually exclusive with dedup. 2955 * 2956 * By leveraging a cryptographically secure checksum, such as SHA256, we 2957 * can compare the checksums of the new data and the old to determine if 2958 * allocating a new block is required. Note that our requirements for 2959 * cryptographic strength are fairly weak: there can't be any accidental 2960 * hash collisions, but we don't need to be secure against intentional 2961 * (malicious) collisions. To trigger a nopwrite, you have to be able 2962 * to write the file to begin with, and triggering an incorrect (hash 2963 * collision) nopwrite is no worse than simply writing to the file. 2964 * That said, there are no known attacks against the checksum algorithms 2965 * used for nopwrite, assuming that the salt and the checksums 2966 * themselves remain secret. 2967 */ 2968 static zio_t * 2969 zio_nop_write(zio_t *zio) 2970 { 2971 blkptr_t *bp = zio->io_bp; 2972 blkptr_t *bp_orig = &zio->io_bp_orig; 2973 zio_prop_t *zp = &zio->io_prop; 2974 2975 ASSERT(BP_GET_LEVEL(bp) == 0); 2976 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE)); 2977 ASSERT(zp->zp_nopwrite); 2978 ASSERT(!zp->zp_dedup); 2979 ASSERT(zio->io_bp_override == NULL); 2980 ASSERT(IO_IS_ALLOCATING(zio)); 2981 2982 /* 2983 * Check to see if the original bp and the new bp have matching 2984 * characteristics (i.e. same checksum, compression algorithms, etc). 2985 * If they don't then just continue with the pipeline which will 2986 * allocate a new bp. 2987 */ 2988 if (BP_IS_HOLE(bp_orig) || 2989 !(zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_flags & 2990 ZCHECKSUM_FLAG_NOPWRITE) || 2991 BP_IS_ENCRYPTED(bp) || BP_IS_ENCRYPTED(bp_orig) || 2992 BP_GET_CHECKSUM(bp) != BP_GET_CHECKSUM(bp_orig) || 2993 BP_GET_COMPRESS(bp) != BP_GET_COMPRESS(bp_orig) || 2994 BP_GET_DEDUP(bp) != BP_GET_DEDUP(bp_orig) || 2995 zp->zp_copies != BP_GET_NDVAS(bp_orig)) 2996 return (zio); 2997 2998 /* 2999 * If the checksums match then reset the pipeline so that we 3000 * avoid allocating a new bp and issuing any I/O. 3001 */ 3002 if (ZIO_CHECKSUM_EQUAL(bp->blk_cksum, bp_orig->blk_cksum)) { 3003 ASSERT(zio_checksum_table[zp->zp_checksum].ci_flags & 3004 ZCHECKSUM_FLAG_NOPWRITE); 3005 ASSERT3U(BP_GET_PSIZE(bp), ==, BP_GET_PSIZE(bp_orig)); 3006 ASSERT3U(BP_GET_LSIZE(bp), ==, BP_GET_LSIZE(bp_orig)); 3007 ASSERT(zp->zp_compress != ZIO_COMPRESS_OFF); 3008 ASSERT(bcmp(&bp->blk_prop, &bp_orig->blk_prop, 3009 sizeof (uint64_t)) == 0); 3010 3011 /* 3012 * If we're overwriting a block that is currently on an 3013 * indirect vdev, then ignore the nopwrite request and 3014 * allow a new block to be allocated on a concrete vdev. 3015 */ 3016 spa_config_enter(zio->io_spa, SCL_VDEV, FTAG, RW_READER); 3017 vdev_t *tvd = vdev_lookup_top(zio->io_spa, 3018 DVA_GET_VDEV(&bp->blk_dva[0])); 3019 if (tvd->vdev_ops == &vdev_indirect_ops) { 3020 spa_config_exit(zio->io_spa, SCL_VDEV, FTAG); 3021 return (zio); 3022 } 3023 spa_config_exit(zio->io_spa, SCL_VDEV, FTAG); 3024 3025 *bp = *bp_orig; 3026 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 3027 zio->io_flags |= ZIO_FLAG_NOPWRITE; 3028 } 3029 3030 return (zio); 3031 } 3032 3033 /* 3034 * ========================================================================== 3035 * Dedup 3036 * ========================================================================== 3037 */ 3038 static void 3039 zio_ddt_child_read_done(zio_t *zio) 3040 { 3041 blkptr_t *bp = zio->io_bp; 3042 ddt_entry_t *dde = zio->io_private; 3043 ddt_phys_t *ddp; 3044 zio_t *pio = zio_unique_parent(zio); 3045 3046 mutex_enter(&pio->io_lock); 3047 ddp = ddt_phys_select(dde, bp); 3048 if (zio->io_error == 0) 3049 ddt_phys_clear(ddp); /* this ddp doesn't need repair */ 3050 3051 if (zio->io_error == 0 && dde->dde_repair_abd == NULL) 3052 dde->dde_repair_abd = zio->io_abd; 3053 else 3054 abd_free(zio->io_abd); 3055 mutex_exit(&pio->io_lock); 3056 } 3057 3058 static zio_t * 3059 zio_ddt_read_start(zio_t *zio) 3060 { 3061 blkptr_t *bp = zio->io_bp; 3062 3063 ASSERT(BP_GET_DEDUP(bp)); 3064 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 3065 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3066 3067 if (zio->io_child_error[ZIO_CHILD_DDT]) { 3068 ddt_t *ddt = ddt_select(zio->io_spa, bp); 3069 ddt_entry_t *dde = ddt_repair_start(ddt, bp); 3070 ddt_phys_t *ddp = dde->dde_phys; 3071 ddt_phys_t *ddp_self = ddt_phys_select(dde, bp); 3072 blkptr_t blk; 3073 3074 ASSERT(zio->io_vsd == NULL); 3075 zio->io_vsd = dde; 3076 3077 if (ddp_self == NULL) 3078 return (zio); 3079 3080 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { 3081 if (ddp->ddp_phys_birth == 0 || ddp == ddp_self) 3082 continue; 3083 ddt_bp_create(ddt->ddt_checksum, &dde->dde_key, ddp, 3084 &blk); 3085 zio_nowait(zio_read(zio, zio->io_spa, &blk, 3086 abd_alloc_for_io(zio->io_size, B_TRUE), 3087 zio->io_size, zio_ddt_child_read_done, dde, 3088 zio->io_priority, ZIO_DDT_CHILD_FLAGS(zio) | 3089 ZIO_FLAG_DONT_PROPAGATE, &zio->io_bookmark)); 3090 } 3091 return (zio); 3092 } 3093 3094 zio_nowait(zio_read(zio, zio->io_spa, bp, 3095 zio->io_abd, zio->io_size, NULL, NULL, zio->io_priority, 3096 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark)); 3097 3098 return (zio); 3099 } 3100 3101 static zio_t * 3102 zio_ddt_read_done(zio_t *zio) 3103 { 3104 blkptr_t *bp = zio->io_bp; 3105 3106 if (zio_wait_for_children(zio, ZIO_CHILD_DDT_BIT, ZIO_WAIT_DONE)) { 3107 return (NULL); 3108 } 3109 3110 ASSERT(BP_GET_DEDUP(bp)); 3111 ASSERT(BP_GET_PSIZE(bp) == zio->io_size); 3112 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3113 3114 if (zio->io_child_error[ZIO_CHILD_DDT]) { 3115 ddt_t *ddt = ddt_select(zio->io_spa, bp); 3116 ddt_entry_t *dde = zio->io_vsd; 3117 if (ddt == NULL) { 3118 ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE); 3119 return (zio); 3120 } 3121 if (dde == NULL) { 3122 zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1; 3123 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE); 3124 return (NULL); 3125 } 3126 if (dde->dde_repair_abd != NULL) { 3127 abd_copy(zio->io_abd, dde->dde_repair_abd, 3128 zio->io_size); 3129 zio->io_child_error[ZIO_CHILD_DDT] = 0; 3130 } 3131 ddt_repair_done(ddt, dde); 3132 zio->io_vsd = NULL; 3133 } 3134 3135 ASSERT(zio->io_vsd == NULL); 3136 3137 return (zio); 3138 } 3139 3140 static boolean_t 3141 zio_ddt_collision(zio_t *zio, ddt_t *ddt, ddt_entry_t *dde) 3142 { 3143 spa_t *spa = zio->io_spa; 3144 boolean_t do_raw = !!(zio->io_flags & ZIO_FLAG_RAW); 3145 3146 ASSERT(!(zio->io_bp_override && do_raw)); 3147 3148 /* 3149 * Note: we compare the original data, not the transformed data, 3150 * because when zio->io_bp is an override bp, we will not have 3151 * pushed the I/O transforms. That's an important optimization 3152 * because otherwise we'd compress/encrypt all dmu_sync() data twice. 3153 * However, we should never get a raw, override zio so in these 3154 * cases we can compare the io_abd directly. This is useful because 3155 * it allows us to do dedup verification even if we don't have access 3156 * to the original data (for instance, if the encryption keys aren't 3157 * loaded). 3158 */ 3159 3160 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 3161 zio_t *lio = dde->dde_lead_zio[p]; 3162 3163 if (lio != NULL && do_raw) { 3164 return (lio->io_size != zio->io_size || 3165 abd_cmp(zio->io_abd, lio->io_abd) != 0); 3166 } else if (lio != NULL) { 3167 return (lio->io_orig_size != zio->io_orig_size || 3168 abd_cmp(zio->io_orig_abd, lio->io_orig_abd) != 0); 3169 } 3170 } 3171 3172 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) { 3173 ddt_phys_t *ddp = &dde->dde_phys[p]; 3174 3175 if (ddp->ddp_phys_birth != 0 && do_raw) { 3176 blkptr_t blk = *zio->io_bp; 3177 uint64_t psize; 3178 abd_t *tmpabd; 3179 int error; 3180 3181 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth); 3182 psize = BP_GET_PSIZE(&blk); 3183 3184 if (psize != zio->io_size) 3185 return (B_TRUE); 3186 3187 ddt_exit(ddt); 3188 3189 tmpabd = abd_alloc_for_io(psize, B_TRUE); 3190 3191 error = zio_wait(zio_read(NULL, spa, &blk, tmpabd, 3192 psize, NULL, NULL, ZIO_PRIORITY_SYNC_READ, 3193 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE | 3194 ZIO_FLAG_RAW, &zio->io_bookmark)); 3195 3196 if (error == 0) { 3197 if (abd_cmp(tmpabd, zio->io_abd) != 0) 3198 error = SET_ERROR(ENOENT); 3199 } 3200 3201 abd_free(tmpabd); 3202 ddt_enter(ddt); 3203 return (error != 0); 3204 } else if (ddp->ddp_phys_birth != 0) { 3205 arc_buf_t *abuf = NULL; 3206 arc_flags_t aflags = ARC_FLAG_WAIT; 3207 blkptr_t blk = *zio->io_bp; 3208 int error; 3209 3210 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth); 3211 3212 if (BP_GET_LSIZE(&blk) != zio->io_orig_size) 3213 return (B_TRUE); 3214 3215 ddt_exit(ddt); 3216 3217 error = arc_read(NULL, spa, &blk, 3218 arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ, 3219 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, 3220 &aflags, &zio->io_bookmark); 3221 3222 if (error == 0) { 3223 if (abd_cmp_buf(zio->io_orig_abd, abuf->b_data, 3224 zio->io_orig_size) != 0) 3225 error = SET_ERROR(ENOENT); 3226 arc_buf_destroy(abuf, &abuf); 3227 } 3228 3229 ddt_enter(ddt); 3230 return (error != 0); 3231 } 3232 } 3233 3234 return (B_FALSE); 3235 } 3236 3237 static void 3238 zio_ddt_child_write_ready(zio_t *zio) 3239 { 3240 int p = zio->io_prop.zp_copies; 3241 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 3242 ddt_entry_t *dde = zio->io_private; 3243 ddt_phys_t *ddp = &dde->dde_phys[p]; 3244 zio_t *pio; 3245 3246 if (zio->io_error) 3247 return; 3248 3249 ddt_enter(ddt); 3250 3251 ASSERT(dde->dde_lead_zio[p] == zio); 3252 3253 ddt_phys_fill(ddp, zio->io_bp); 3254 3255 zio_link_t *zl = NULL; 3256 while ((pio = zio_walk_parents(zio, &zl)) != NULL) 3257 ddt_bp_fill(ddp, pio->io_bp, zio->io_txg); 3258 3259 ddt_exit(ddt); 3260 } 3261 3262 static void 3263 zio_ddt_child_write_done(zio_t *zio) 3264 { 3265 int p = zio->io_prop.zp_copies; 3266 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp); 3267 ddt_entry_t *dde = zio->io_private; 3268 ddt_phys_t *ddp = &dde->dde_phys[p]; 3269 3270 ddt_enter(ddt); 3271 3272 ASSERT(ddp->ddp_refcnt == 0); 3273 ASSERT(dde->dde_lead_zio[p] == zio); 3274 dde->dde_lead_zio[p] = NULL; 3275 3276 if (zio->io_error == 0) { 3277 zio_link_t *zl = NULL; 3278 while (zio_walk_parents(zio, &zl) != NULL) 3279 ddt_phys_addref(ddp); 3280 } else { 3281 ddt_phys_clear(ddp); 3282 } 3283 3284 ddt_exit(ddt); 3285 } 3286 3287 static zio_t * 3288 zio_ddt_write(zio_t *zio) 3289 { 3290 spa_t *spa = zio->io_spa; 3291 blkptr_t *bp = zio->io_bp; 3292 uint64_t txg = zio->io_txg; 3293 zio_prop_t *zp = &zio->io_prop; 3294 int p = zp->zp_copies; 3295 zio_t *cio = NULL; 3296 ddt_t *ddt = ddt_select(spa, bp); 3297 ddt_entry_t *dde; 3298 ddt_phys_t *ddp; 3299 3300 ASSERT(BP_GET_DEDUP(bp)); 3301 ASSERT(BP_GET_CHECKSUM(bp) == zp->zp_checksum); 3302 ASSERT(BP_IS_HOLE(bp) || zio->io_bp_override); 3303 ASSERT(!(zio->io_bp_override && (zio->io_flags & ZIO_FLAG_RAW))); 3304 3305 ddt_enter(ddt); 3306 dde = ddt_lookup(ddt, bp, B_TRUE); 3307 ddp = &dde->dde_phys[p]; 3308 3309 if (zp->zp_dedup_verify && zio_ddt_collision(zio, ddt, dde)) { 3310 /* 3311 * If we're using a weak checksum, upgrade to a strong checksum 3312 * and try again. If we're already using a strong checksum, 3313 * we can't resolve it, so just convert to an ordinary write. 3314 * (And automatically e-mail a paper to Nature?) 3315 */ 3316 if (!(zio_checksum_table[zp->zp_checksum].ci_flags & 3317 ZCHECKSUM_FLAG_DEDUP)) { 3318 zp->zp_checksum = spa_dedup_checksum(spa); 3319 zio_pop_transforms(zio); 3320 zio->io_stage = ZIO_STAGE_OPEN; 3321 BP_ZERO(bp); 3322 } else { 3323 zp->zp_dedup = B_FALSE; 3324 BP_SET_DEDUP(bp, B_FALSE); 3325 } 3326 ASSERT(!BP_GET_DEDUP(bp)); 3327 zio->io_pipeline = ZIO_WRITE_PIPELINE; 3328 ddt_exit(ddt); 3329 return (zio); 3330 } 3331 3332 if (ddp->ddp_phys_birth != 0 || dde->dde_lead_zio[p] != NULL) { 3333 if (ddp->ddp_phys_birth != 0) 3334 ddt_bp_fill(ddp, bp, txg); 3335 if (dde->dde_lead_zio[p] != NULL) 3336 zio_add_child(zio, dde->dde_lead_zio[p]); 3337 else 3338 ddt_phys_addref(ddp); 3339 } else if (zio->io_bp_override) { 3340 ASSERT(bp->blk_birth == txg); 3341 ASSERT(BP_EQUAL(bp, zio->io_bp_override)); 3342 ddt_phys_fill(ddp, bp); 3343 ddt_phys_addref(ddp); 3344 } else { 3345 cio = zio_write(zio, spa, txg, bp, zio->io_orig_abd, 3346 zio->io_orig_size, zio->io_orig_size, zp, 3347 zio_ddt_child_write_ready, NULL, NULL, 3348 zio_ddt_child_write_done, dde, zio->io_priority, 3349 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark); 3350 3351 zio_push_transform(cio, zio->io_abd, zio->io_size, 0, NULL); 3352 dde->dde_lead_zio[p] = cio; 3353 } 3354 3355 ddt_exit(ddt); 3356 3357 zio_nowait(cio); 3358 3359 return (zio); 3360 } 3361 3362 ddt_entry_t *freedde; /* for debugging */ 3363 3364 static zio_t * 3365 zio_ddt_free(zio_t *zio) 3366 { 3367 spa_t *spa = zio->io_spa; 3368 blkptr_t *bp = zio->io_bp; 3369 ddt_t *ddt = ddt_select(spa, bp); 3370 ddt_entry_t *dde; 3371 ddt_phys_t *ddp; 3372 3373 ASSERT(BP_GET_DEDUP(bp)); 3374 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 3375 3376 ddt_enter(ddt); 3377 freedde = dde = ddt_lookup(ddt, bp, B_TRUE); 3378 if (dde) { 3379 ddp = ddt_phys_select(dde, bp); 3380 if (ddp) 3381 ddt_phys_decref(ddp); 3382 } 3383 ddt_exit(ddt); 3384 3385 return (zio); 3386 } 3387 3388 /* 3389 * ========================================================================== 3390 * Allocate and free blocks 3391 * ========================================================================== 3392 */ 3393 3394 static zio_t * 3395 zio_io_to_allocate(spa_t *spa, int allocator) 3396 { 3397 zio_t *zio; 3398 3399 ASSERT(MUTEX_HELD(&spa->spa_allocs[allocator].spaa_lock)); 3400 3401 zio = avl_first(&spa->spa_allocs[allocator].spaa_tree); 3402 if (zio == NULL) 3403 return (NULL); 3404 3405 ASSERT(IO_IS_ALLOCATING(zio)); 3406 3407 /* 3408 * Try to place a reservation for this zio. If we're unable to 3409 * reserve then we throttle. 3410 */ 3411 ASSERT3U(zio->io_allocator, ==, allocator); 3412 if (!metaslab_class_throttle_reserve(zio->io_metaslab_class, 3413 zio->io_prop.zp_copies, allocator, zio, 0)) { 3414 return (NULL); 3415 } 3416 3417 avl_remove(&spa->spa_allocs[allocator].spaa_tree, zio); 3418 ASSERT3U(zio->io_stage, <, ZIO_STAGE_DVA_ALLOCATE); 3419 3420 return (zio); 3421 } 3422 3423 static zio_t * 3424 zio_dva_throttle(zio_t *zio) 3425 { 3426 spa_t *spa = zio->io_spa; 3427 zio_t *nio; 3428 metaslab_class_t *mc; 3429 3430 /* locate an appropriate allocation class */ 3431 mc = spa_preferred_class(spa, zio->io_size, zio->io_prop.zp_type, 3432 zio->io_prop.zp_level, zio->io_prop.zp_zpl_smallblk); 3433 3434 if (zio->io_priority == ZIO_PRIORITY_SYNC_WRITE || 3435 !mc->mc_alloc_throttle_enabled || 3436 zio->io_child_type == ZIO_CHILD_GANG || 3437 zio->io_flags & ZIO_FLAG_NODATA) { 3438 return (zio); 3439 } 3440 3441 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 3442 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 3443 ASSERT3U(zio->io_queued_timestamp, >, 0); 3444 ASSERT(zio->io_stage == ZIO_STAGE_DVA_THROTTLE); 3445 3446 zbookmark_phys_t *bm = &zio->io_bookmark; 3447 /* 3448 * We want to try to use as many allocators as possible to help improve 3449 * performance, but we also want logically adjacent IOs to be physically 3450 * adjacent to improve sequential read performance. We chunk each object 3451 * into 2^20 block regions, and then hash based on the objset, object, 3452 * level, and region to accomplish both of these goals. 3453 */ 3454 int allocator = (uint_t)cityhash4(bm->zb_objset, bm->zb_object, 3455 bm->zb_level, bm->zb_blkid >> 20) % spa->spa_alloc_count; 3456 zio->io_allocator = allocator; 3457 zio->io_metaslab_class = mc; 3458 mutex_enter(&spa->spa_allocs[allocator].spaa_lock); 3459 avl_add(&spa->spa_allocs[allocator].spaa_tree, zio); 3460 nio = zio_io_to_allocate(spa, allocator); 3461 mutex_exit(&spa->spa_allocs[allocator].spaa_lock); 3462 return (nio); 3463 } 3464 3465 static void 3466 zio_allocate_dispatch(spa_t *spa, int allocator) 3467 { 3468 zio_t *zio; 3469 3470 mutex_enter(&spa->spa_allocs[allocator].spaa_lock); 3471 zio = zio_io_to_allocate(spa, allocator); 3472 mutex_exit(&spa->spa_allocs[allocator].spaa_lock); 3473 if (zio == NULL) 3474 return; 3475 3476 ASSERT3U(zio->io_stage, ==, ZIO_STAGE_DVA_THROTTLE); 3477 ASSERT0(zio->io_error); 3478 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_TRUE); 3479 } 3480 3481 static zio_t * 3482 zio_dva_allocate(zio_t *zio) 3483 { 3484 spa_t *spa = zio->io_spa; 3485 metaslab_class_t *mc; 3486 blkptr_t *bp = zio->io_bp; 3487 int error; 3488 int flags = 0; 3489 3490 if (zio->io_gang_leader == NULL) { 3491 ASSERT(zio->io_child_type > ZIO_CHILD_GANG); 3492 zio->io_gang_leader = zio; 3493 } 3494 3495 ASSERT(BP_IS_HOLE(bp)); 3496 ASSERT0(BP_GET_NDVAS(bp)); 3497 ASSERT3U(zio->io_prop.zp_copies, >, 0); 3498 ASSERT3U(zio->io_prop.zp_copies, <=, spa_max_replication(spa)); 3499 ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp)); 3500 3501 flags |= (zio->io_flags & ZIO_FLAG_FASTWRITE) ? METASLAB_FASTWRITE : 0; 3502 if (zio->io_flags & ZIO_FLAG_NODATA) 3503 flags |= METASLAB_DONT_THROTTLE; 3504 if (zio->io_flags & ZIO_FLAG_GANG_CHILD) 3505 flags |= METASLAB_GANG_CHILD; 3506 if (zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE) 3507 flags |= METASLAB_ASYNC_ALLOC; 3508 3509 /* 3510 * if not already chosen, locate an appropriate allocation class 3511 */ 3512 mc = zio->io_metaslab_class; 3513 if (mc == NULL) { 3514 mc = spa_preferred_class(spa, zio->io_size, 3515 zio->io_prop.zp_type, zio->io_prop.zp_level, 3516 zio->io_prop.zp_zpl_smallblk); 3517 zio->io_metaslab_class = mc; 3518 } 3519 3520 /* 3521 * Try allocating the block in the usual metaslab class. 3522 * If that's full, allocate it in the normal class. 3523 * If that's full, allocate as a gang block, 3524 * and if all are full, the allocation fails (which shouldn't happen). 3525 * 3526 * Note that we do not fall back on embedded slog (ZIL) space, to 3527 * preserve unfragmented slog space, which is critical for decent 3528 * sync write performance. If a log allocation fails, we will fall 3529 * back to spa_sync() which is abysmal for performance. 3530 */ 3531 error = metaslab_alloc(spa, mc, zio->io_size, bp, 3532 zio->io_prop.zp_copies, zio->io_txg, NULL, flags, 3533 &zio->io_alloc_list, zio, zio->io_allocator); 3534 3535 /* 3536 * Fallback to normal class when an alloc class is full 3537 */ 3538 if (error == ENOSPC && mc != spa_normal_class(spa)) { 3539 /* 3540 * If throttling, transfer reservation over to normal class. 3541 * The io_allocator slot can remain the same even though we 3542 * are switching classes. 3543 */ 3544 if (mc->mc_alloc_throttle_enabled && 3545 (zio->io_flags & ZIO_FLAG_IO_ALLOCATING)) { 3546 metaslab_class_throttle_unreserve(mc, 3547 zio->io_prop.zp_copies, zio->io_allocator, zio); 3548 zio->io_flags &= ~ZIO_FLAG_IO_ALLOCATING; 3549 3550 VERIFY(metaslab_class_throttle_reserve( 3551 spa_normal_class(spa), 3552 zio->io_prop.zp_copies, zio->io_allocator, zio, 3553 flags | METASLAB_MUST_RESERVE)); 3554 } 3555 zio->io_metaslab_class = mc = spa_normal_class(spa); 3556 if (zfs_flags & ZFS_DEBUG_METASLAB_ALLOC) { 3557 zfs_dbgmsg("%s: metaslab allocation failure, " 3558 "trying normal class: zio %px, size %llu, error %d", 3559 spa_name(spa), zio, (u_longlong_t)zio->io_size, 3560 error); 3561 } 3562 3563 error = metaslab_alloc(spa, mc, zio->io_size, bp, 3564 zio->io_prop.zp_copies, zio->io_txg, NULL, flags, 3565 &zio->io_alloc_list, zio, zio->io_allocator); 3566 } 3567 3568 if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE) { 3569 if (zfs_flags & ZFS_DEBUG_METASLAB_ALLOC) { 3570 zfs_dbgmsg("%s: metaslab allocation failure, " 3571 "trying ganging: zio %px, size %llu, error %d", 3572 spa_name(spa), zio, (u_longlong_t)zio->io_size, 3573 error); 3574 } 3575 return (zio_write_gang_block(zio, mc)); 3576 } 3577 if (error != 0) { 3578 if (error != ENOSPC || 3579 (zfs_flags & ZFS_DEBUG_METASLAB_ALLOC)) { 3580 zfs_dbgmsg("%s: metaslab allocation failure: zio %px, " 3581 "size %llu, error %d", 3582 spa_name(spa), zio, (u_longlong_t)zio->io_size, 3583 error); 3584 } 3585 zio->io_error = error; 3586 } 3587 3588 return (zio); 3589 } 3590 3591 static zio_t * 3592 zio_dva_free(zio_t *zio) 3593 { 3594 metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE); 3595 3596 return (zio); 3597 } 3598 3599 static zio_t * 3600 zio_dva_claim(zio_t *zio) 3601 { 3602 int error; 3603 3604 error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg); 3605 if (error) 3606 zio->io_error = error; 3607 3608 return (zio); 3609 } 3610 3611 /* 3612 * Undo an allocation. This is used by zio_done() when an I/O fails 3613 * and we want to give back the block we just allocated. 3614 * This handles both normal blocks and gang blocks. 3615 */ 3616 static void 3617 zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp) 3618 { 3619 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp)); 3620 ASSERT(zio->io_bp_override == NULL); 3621 3622 if (!BP_IS_HOLE(bp)) 3623 metaslab_free(zio->io_spa, bp, bp->blk_birth, B_TRUE); 3624 3625 if (gn != NULL) { 3626 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) { 3627 zio_dva_unallocate(zio, gn->gn_child[g], 3628 &gn->gn_gbh->zg_blkptr[g]); 3629 } 3630 } 3631 } 3632 3633 /* 3634 * Try to allocate an intent log block. Return 0 on success, errno on failure. 3635 */ 3636 int 3637 zio_alloc_zil(spa_t *spa, objset_t *os, uint64_t txg, blkptr_t *new_bp, 3638 uint64_t size, boolean_t *slog) 3639 { 3640 int error = 1; 3641 zio_alloc_list_t io_alloc_list; 3642 3643 ASSERT(txg > spa_syncing_txg(spa)); 3644 3645 metaslab_trace_init(&io_alloc_list); 3646 3647 /* 3648 * Block pointer fields are useful to metaslabs for stats and debugging. 3649 * Fill in the obvious ones before calling into metaslab_alloc(). 3650 */ 3651 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG); 3652 BP_SET_PSIZE(new_bp, size); 3653 BP_SET_LEVEL(new_bp, 0); 3654 3655 /* 3656 * When allocating a zil block, we don't have information about 3657 * the final destination of the block except the objset it's part 3658 * of, so we just hash the objset ID to pick the allocator to get 3659 * some parallelism. 3660 */ 3661 int flags = METASLAB_FASTWRITE | METASLAB_ZIL; 3662 int allocator = (uint_t)cityhash4(0, 0, 0, 3663 os->os_dsl_dataset->ds_object) % spa->spa_alloc_count; 3664 error = metaslab_alloc(spa, spa_log_class(spa), size, new_bp, 1, 3665 txg, NULL, flags, &io_alloc_list, NULL, allocator); 3666 *slog = (error == 0); 3667 if (error != 0) { 3668 error = metaslab_alloc(spa, spa_embedded_log_class(spa), size, 3669 new_bp, 1, txg, NULL, flags, 3670 &io_alloc_list, NULL, allocator); 3671 } 3672 if (error != 0) { 3673 error = metaslab_alloc(spa, spa_normal_class(spa), size, 3674 new_bp, 1, txg, NULL, flags, 3675 &io_alloc_list, NULL, allocator); 3676 } 3677 metaslab_trace_fini(&io_alloc_list); 3678 3679 if (error == 0) { 3680 BP_SET_LSIZE(new_bp, size); 3681 BP_SET_PSIZE(new_bp, size); 3682 BP_SET_COMPRESS(new_bp, ZIO_COMPRESS_OFF); 3683 BP_SET_CHECKSUM(new_bp, 3684 spa_version(spa) >= SPA_VERSION_SLIM_ZIL 3685 ? ZIO_CHECKSUM_ZILOG2 : ZIO_CHECKSUM_ZILOG); 3686 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG); 3687 BP_SET_LEVEL(new_bp, 0); 3688 BP_SET_DEDUP(new_bp, 0); 3689 BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER); 3690 3691 /* 3692 * encrypted blocks will require an IV and salt. We generate 3693 * these now since we will not be rewriting the bp at 3694 * rewrite time. 3695 */ 3696 if (os->os_encrypted) { 3697 uint8_t iv[ZIO_DATA_IV_LEN]; 3698 uint8_t salt[ZIO_DATA_SALT_LEN]; 3699 3700 BP_SET_CRYPT(new_bp, B_TRUE); 3701 VERIFY0(spa_crypt_get_salt(spa, 3702 dmu_objset_id(os), salt)); 3703 VERIFY0(zio_crypt_generate_iv(iv)); 3704 3705 zio_crypt_encode_params_bp(new_bp, salt, iv); 3706 } 3707 } else { 3708 zfs_dbgmsg("%s: zil block allocation failure: " 3709 "size %llu, error %d", spa_name(spa), (u_longlong_t)size, 3710 error); 3711 } 3712 3713 return (error); 3714 } 3715 3716 /* 3717 * ========================================================================== 3718 * Read and write to physical devices 3719 * ========================================================================== 3720 */ 3721 3722 /* 3723 * Issue an I/O to the underlying vdev. Typically the issue pipeline 3724 * stops after this stage and will resume upon I/O completion. 3725 * However, there are instances where the vdev layer may need to 3726 * continue the pipeline when an I/O was not issued. Since the I/O 3727 * that was sent to the vdev layer might be different than the one 3728 * currently active in the pipeline (see vdev_queue_io()), we explicitly 3729 * force the underlying vdev layers to call either zio_execute() or 3730 * zio_interrupt() to ensure that the pipeline continues with the correct I/O. 3731 */ 3732 static zio_t * 3733 zio_vdev_io_start(zio_t *zio) 3734 { 3735 vdev_t *vd = zio->io_vd; 3736 uint64_t align; 3737 spa_t *spa = zio->io_spa; 3738 3739 zio->io_delay = 0; 3740 3741 ASSERT(zio->io_error == 0); 3742 ASSERT(zio->io_child_error[ZIO_CHILD_VDEV] == 0); 3743 3744 if (vd == NULL) { 3745 if (!(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 3746 spa_config_enter(spa, SCL_ZIO, zio, RW_READER); 3747 3748 /* 3749 * The mirror_ops handle multiple DVAs in a single BP. 3750 */ 3751 vdev_mirror_ops.vdev_op_io_start(zio); 3752 return (NULL); 3753 } 3754 3755 ASSERT3P(zio->io_logical, !=, zio); 3756 if (zio->io_type == ZIO_TYPE_WRITE) { 3757 ASSERT(spa->spa_trust_config); 3758 3759 /* 3760 * Note: the code can handle other kinds of writes, 3761 * but we don't expect them. 3762 */ 3763 if (zio->io_vd->vdev_noalloc) { 3764 ASSERT(zio->io_flags & 3765 (ZIO_FLAG_PHYSICAL | ZIO_FLAG_SELF_HEAL | 3766 ZIO_FLAG_RESILVER | ZIO_FLAG_INDUCE_DAMAGE)); 3767 } 3768 } 3769 3770 align = 1ULL << vd->vdev_top->vdev_ashift; 3771 3772 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL) && 3773 P2PHASE(zio->io_size, align) != 0) { 3774 /* Transform logical writes to be a full physical block size. */ 3775 uint64_t asize = P2ROUNDUP(zio->io_size, align); 3776 abd_t *abuf = abd_alloc_sametype(zio->io_abd, asize); 3777 ASSERT(vd == vd->vdev_top); 3778 if (zio->io_type == ZIO_TYPE_WRITE) { 3779 abd_copy(abuf, zio->io_abd, zio->io_size); 3780 abd_zero_off(abuf, zio->io_size, asize - zio->io_size); 3781 } 3782 zio_push_transform(zio, abuf, asize, asize, zio_subblock); 3783 } 3784 3785 /* 3786 * If this is not a physical io, make sure that it is properly aligned 3787 * before proceeding. 3788 */ 3789 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL)) { 3790 ASSERT0(P2PHASE(zio->io_offset, align)); 3791 ASSERT0(P2PHASE(zio->io_size, align)); 3792 } else { 3793 /* 3794 * For physical writes, we allow 512b aligned writes and assume 3795 * the device will perform a read-modify-write as necessary. 3796 */ 3797 ASSERT0(P2PHASE(zio->io_offset, SPA_MINBLOCKSIZE)); 3798 ASSERT0(P2PHASE(zio->io_size, SPA_MINBLOCKSIZE)); 3799 } 3800 3801 VERIFY(zio->io_type != ZIO_TYPE_WRITE || spa_writeable(spa)); 3802 3803 /* 3804 * If this is a repair I/O, and there's no self-healing involved -- 3805 * that is, we're just resilvering what we expect to resilver -- 3806 * then don't do the I/O unless zio's txg is actually in vd's DTL. 3807 * This prevents spurious resilvering. 3808 * 3809 * There are a few ways that we can end up creating these spurious 3810 * resilver i/os: 3811 * 3812 * 1. A resilver i/o will be issued if any DVA in the BP has a 3813 * dirty DTL. The mirror code will issue resilver writes to 3814 * each DVA, including the one(s) that are not on vdevs with dirty 3815 * DTLs. 3816 * 3817 * 2. With nested replication, which happens when we have a 3818 * "replacing" or "spare" vdev that's a child of a mirror or raidz. 3819 * For example, given mirror(replacing(A+B), C), it's likely that 3820 * only A is out of date (it's the new device). In this case, we'll 3821 * read from C, then use the data to resilver A+B -- but we don't 3822 * actually want to resilver B, just A. The top-level mirror has no 3823 * way to know this, so instead we just discard unnecessary repairs 3824 * as we work our way down the vdev tree. 3825 * 3826 * 3. ZTEST also creates mirrors of mirrors, mirrors of raidz, etc. 3827 * The same logic applies to any form of nested replication: ditto 3828 * + mirror, RAID-Z + replacing, etc. 3829 * 3830 * However, indirect vdevs point off to other vdevs which may have 3831 * DTL's, so we never bypass them. The child i/os on concrete vdevs 3832 * will be properly bypassed instead. 3833 * 3834 * Leaf DTL_PARTIAL can be empty when a legitimate write comes from 3835 * a dRAID spare vdev. For example, when a dRAID spare is first 3836 * used, its spare blocks need to be written to but the leaf vdev's 3837 * of such blocks can have empty DTL_PARTIAL. 3838 * 3839 * There seemed no clean way to allow such writes while bypassing 3840 * spurious ones. At this point, just avoid all bypassing for dRAID 3841 * for correctness. 3842 */ 3843 if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) && 3844 !(zio->io_flags & ZIO_FLAG_SELF_HEAL) && 3845 zio->io_txg != 0 && /* not a delegated i/o */ 3846 vd->vdev_ops != &vdev_indirect_ops && 3847 vd->vdev_top->vdev_ops != &vdev_draid_ops && 3848 !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) { 3849 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 3850 zio_vdev_io_bypass(zio); 3851 return (zio); 3852 } 3853 3854 /* 3855 * Select the next best leaf I/O to process. Distributed spares are 3856 * excluded since they dispatch the I/O directly to a leaf vdev after 3857 * applying the dRAID mapping. 3858 */ 3859 if (vd->vdev_ops->vdev_op_leaf && 3860 vd->vdev_ops != &vdev_draid_spare_ops && 3861 (zio->io_type == ZIO_TYPE_READ || 3862 zio->io_type == ZIO_TYPE_WRITE || 3863 zio->io_type == ZIO_TYPE_TRIM)) { 3864 3865 if (zio->io_type == ZIO_TYPE_READ && vdev_cache_read(zio)) 3866 return (zio); 3867 3868 if ((zio = vdev_queue_io(zio)) == NULL) 3869 return (NULL); 3870 3871 if (!vdev_accessible(vd, zio)) { 3872 zio->io_error = SET_ERROR(ENXIO); 3873 zio_interrupt(zio); 3874 return (NULL); 3875 } 3876 zio->io_delay = gethrtime(); 3877 } 3878 3879 vd->vdev_ops->vdev_op_io_start(zio); 3880 return (NULL); 3881 } 3882 3883 static zio_t * 3884 zio_vdev_io_done(zio_t *zio) 3885 { 3886 vdev_t *vd = zio->io_vd; 3887 vdev_ops_t *ops = vd ? vd->vdev_ops : &vdev_mirror_ops; 3888 boolean_t unexpected_error = B_FALSE; 3889 3890 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV_BIT, ZIO_WAIT_DONE)) { 3891 return (NULL); 3892 } 3893 3894 ASSERT(zio->io_type == ZIO_TYPE_READ || 3895 zio->io_type == ZIO_TYPE_WRITE || zio->io_type == ZIO_TYPE_TRIM); 3896 3897 if (zio->io_delay) 3898 zio->io_delay = gethrtime() - zio->io_delay; 3899 3900 if (vd != NULL && vd->vdev_ops->vdev_op_leaf && 3901 vd->vdev_ops != &vdev_draid_spare_ops) { 3902 vdev_queue_io_done(zio); 3903 3904 if (zio->io_type == ZIO_TYPE_WRITE) 3905 vdev_cache_write(zio); 3906 3907 if (zio_injection_enabled && zio->io_error == 0) 3908 zio->io_error = zio_handle_device_injections(vd, zio, 3909 EIO, EILSEQ); 3910 3911 if (zio_injection_enabled && zio->io_error == 0) 3912 zio->io_error = zio_handle_label_injection(zio, EIO); 3913 3914 if (zio->io_error && zio->io_type != ZIO_TYPE_TRIM) { 3915 if (!vdev_accessible(vd, zio)) { 3916 zio->io_error = SET_ERROR(ENXIO); 3917 } else { 3918 unexpected_error = B_TRUE; 3919 } 3920 } 3921 } 3922 3923 ops->vdev_op_io_done(zio); 3924 3925 if (unexpected_error) 3926 VERIFY(vdev_probe(vd, zio) == NULL); 3927 3928 return (zio); 3929 } 3930 3931 /* 3932 * This function is used to change the priority of an existing zio that is 3933 * currently in-flight. This is used by the arc to upgrade priority in the 3934 * event that a demand read is made for a block that is currently queued 3935 * as a scrub or async read IO. Otherwise, the high priority read request 3936 * would end up having to wait for the lower priority IO. 3937 */ 3938 void 3939 zio_change_priority(zio_t *pio, zio_priority_t priority) 3940 { 3941 zio_t *cio, *cio_next; 3942 zio_link_t *zl = NULL; 3943 3944 ASSERT3U(priority, <, ZIO_PRIORITY_NUM_QUEUEABLE); 3945 3946 if (pio->io_vd != NULL && pio->io_vd->vdev_ops->vdev_op_leaf) { 3947 vdev_queue_change_io_priority(pio, priority); 3948 } else { 3949 pio->io_priority = priority; 3950 } 3951 3952 mutex_enter(&pio->io_lock); 3953 for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) { 3954 cio_next = zio_walk_children(pio, &zl); 3955 zio_change_priority(cio, priority); 3956 } 3957 mutex_exit(&pio->io_lock); 3958 } 3959 3960 /* 3961 * For non-raidz ZIOs, we can just copy aside the bad data read from the 3962 * disk, and use that to finish the checksum ereport later. 3963 */ 3964 static void 3965 zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr, 3966 const abd_t *good_buf) 3967 { 3968 /* no processing needed */ 3969 zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE); 3970 } 3971 3972 void 3973 zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr) 3974 { 3975 void *abd = abd_alloc_sametype(zio->io_abd, zio->io_size); 3976 3977 abd_copy(abd, zio->io_abd, zio->io_size); 3978 3979 zcr->zcr_cbinfo = zio->io_size; 3980 zcr->zcr_cbdata = abd; 3981 zcr->zcr_finish = zio_vsd_default_cksum_finish; 3982 zcr->zcr_free = zio_abd_free; 3983 } 3984 3985 static zio_t * 3986 zio_vdev_io_assess(zio_t *zio) 3987 { 3988 vdev_t *vd = zio->io_vd; 3989 3990 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV_BIT, ZIO_WAIT_DONE)) { 3991 return (NULL); 3992 } 3993 3994 if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER)) 3995 spa_config_exit(zio->io_spa, SCL_ZIO, zio); 3996 3997 if (zio->io_vsd != NULL) { 3998 zio->io_vsd_ops->vsd_free(zio); 3999 zio->io_vsd = NULL; 4000 } 4001 4002 if (zio_injection_enabled && zio->io_error == 0) 4003 zio->io_error = zio_handle_fault_injection(zio, EIO); 4004 4005 /* 4006 * If the I/O failed, determine whether we should attempt to retry it. 4007 * 4008 * On retry, we cut in line in the issue queue, since we don't want 4009 * compression/checksumming/etc. work to prevent our (cheap) IO reissue. 4010 */ 4011 if (zio->io_error && vd == NULL && 4012 !(zio->io_flags & (ZIO_FLAG_DONT_RETRY | ZIO_FLAG_IO_RETRY))) { 4013 ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_QUEUE)); /* not a leaf */ 4014 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_BYPASS)); /* not a leaf */ 4015 zio->io_error = 0; 4016 zio->io_flags |= ZIO_FLAG_IO_RETRY | 4017 ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE; 4018 zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1; 4019 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, 4020 zio_requeue_io_start_cut_in_line); 4021 return (NULL); 4022 } 4023 4024 /* 4025 * If we got an error on a leaf device, convert it to ENXIO 4026 * if the device is not accessible at all. 4027 */ 4028 if (zio->io_error && vd != NULL && vd->vdev_ops->vdev_op_leaf && 4029 !vdev_accessible(vd, zio)) 4030 zio->io_error = SET_ERROR(ENXIO); 4031 4032 /* 4033 * If we can't write to an interior vdev (mirror or RAID-Z), 4034 * set vdev_cant_write so that we stop trying to allocate from it. 4035 */ 4036 if (zio->io_error == ENXIO && zio->io_type == ZIO_TYPE_WRITE && 4037 vd != NULL && !vd->vdev_ops->vdev_op_leaf) { 4038 vdev_dbgmsg(vd, "zio_vdev_io_assess(zio=%px) setting " 4039 "cant_write=TRUE due to write failure with ENXIO", 4040 zio); 4041 vd->vdev_cant_write = B_TRUE; 4042 } 4043 4044 /* 4045 * If a cache flush returns ENOTSUP or ENOTTY, we know that no future 4046 * attempts will ever succeed. In this case we set a persistent 4047 * boolean flag so that we don't bother with it in the future. 4048 */ 4049 if ((zio->io_error == ENOTSUP || zio->io_error == ENOTTY) && 4050 zio->io_type == ZIO_TYPE_IOCTL && 4051 zio->io_cmd == DKIOCFLUSHWRITECACHE && vd != NULL) 4052 vd->vdev_nowritecache = B_TRUE; 4053 4054 if (zio->io_error) 4055 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 4056 4057 if (vd != NULL && vd->vdev_ops->vdev_op_leaf && 4058 zio->io_physdone != NULL) { 4059 ASSERT(!(zio->io_flags & ZIO_FLAG_DELEGATED)); 4060 ASSERT(zio->io_child_type == ZIO_CHILD_VDEV); 4061 zio->io_physdone(zio->io_logical); 4062 } 4063 4064 return (zio); 4065 } 4066 4067 void 4068 zio_vdev_io_reissue(zio_t *zio) 4069 { 4070 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 4071 ASSERT(zio->io_error == 0); 4072 4073 zio->io_stage >>= 1; 4074 } 4075 4076 void 4077 zio_vdev_io_redone(zio_t *zio) 4078 { 4079 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE); 4080 4081 zio->io_stage >>= 1; 4082 } 4083 4084 void 4085 zio_vdev_io_bypass(zio_t *zio) 4086 { 4087 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START); 4088 ASSERT(zio->io_error == 0); 4089 4090 zio->io_flags |= ZIO_FLAG_IO_BYPASS; 4091 zio->io_stage = ZIO_STAGE_VDEV_IO_ASSESS >> 1; 4092 } 4093 4094 /* 4095 * ========================================================================== 4096 * Encrypt and store encryption parameters 4097 * ========================================================================== 4098 */ 4099 4100 4101 /* 4102 * This function is used for ZIO_STAGE_ENCRYPT. It is responsible for 4103 * managing the storage of encryption parameters and passing them to the 4104 * lower-level encryption functions. 4105 */ 4106 static zio_t * 4107 zio_encrypt(zio_t *zio) 4108 { 4109 zio_prop_t *zp = &zio->io_prop; 4110 spa_t *spa = zio->io_spa; 4111 blkptr_t *bp = zio->io_bp; 4112 uint64_t psize = BP_GET_PSIZE(bp); 4113 uint64_t dsobj = zio->io_bookmark.zb_objset; 4114 dmu_object_type_t ot = BP_GET_TYPE(bp); 4115 void *enc_buf = NULL; 4116 abd_t *eabd = NULL; 4117 uint8_t salt[ZIO_DATA_SALT_LEN]; 4118 uint8_t iv[ZIO_DATA_IV_LEN]; 4119 uint8_t mac[ZIO_DATA_MAC_LEN]; 4120 boolean_t no_crypt = B_FALSE; 4121 4122 /* the root zio already encrypted the data */ 4123 if (zio->io_child_type == ZIO_CHILD_GANG) 4124 return (zio); 4125 4126 /* only ZIL blocks are re-encrypted on rewrite */ 4127 if (!IO_IS_ALLOCATING(zio) && ot != DMU_OT_INTENT_LOG) 4128 return (zio); 4129 4130 if (!(zp->zp_encrypt || BP_IS_ENCRYPTED(bp))) { 4131 BP_SET_CRYPT(bp, B_FALSE); 4132 return (zio); 4133 } 4134 4135 /* if we are doing raw encryption set the provided encryption params */ 4136 if (zio->io_flags & ZIO_FLAG_RAW_ENCRYPT) { 4137 ASSERT0(BP_GET_LEVEL(bp)); 4138 BP_SET_CRYPT(bp, B_TRUE); 4139 BP_SET_BYTEORDER(bp, zp->zp_byteorder); 4140 if (ot != DMU_OT_OBJSET) 4141 zio_crypt_encode_mac_bp(bp, zp->zp_mac); 4142 4143 /* dnode blocks must be written out in the provided byteorder */ 4144 if (zp->zp_byteorder != ZFS_HOST_BYTEORDER && 4145 ot == DMU_OT_DNODE) { 4146 void *bswap_buf = zio_buf_alloc(psize); 4147 abd_t *babd = abd_get_from_buf(bswap_buf, psize); 4148 4149 ASSERT3U(BP_GET_COMPRESS(bp), ==, ZIO_COMPRESS_OFF); 4150 abd_copy_to_buf(bswap_buf, zio->io_abd, psize); 4151 dmu_ot_byteswap[DMU_OT_BYTESWAP(ot)].ob_func(bswap_buf, 4152 psize); 4153 4154 abd_take_ownership_of_buf(babd, B_TRUE); 4155 zio_push_transform(zio, babd, psize, psize, NULL); 4156 } 4157 4158 if (DMU_OT_IS_ENCRYPTED(ot)) 4159 zio_crypt_encode_params_bp(bp, zp->zp_salt, zp->zp_iv); 4160 return (zio); 4161 } 4162 4163 /* indirect blocks only maintain a cksum of the lower level MACs */ 4164 if (BP_GET_LEVEL(bp) > 0) { 4165 BP_SET_CRYPT(bp, B_TRUE); 4166 VERIFY0(zio_crypt_do_indirect_mac_checksum_abd(B_TRUE, 4167 zio->io_orig_abd, BP_GET_LSIZE(bp), BP_SHOULD_BYTESWAP(bp), 4168 mac)); 4169 zio_crypt_encode_mac_bp(bp, mac); 4170 return (zio); 4171 } 4172 4173 /* 4174 * Objset blocks are a special case since they have 2 256-bit MACs 4175 * embedded within them. 4176 */ 4177 if (ot == DMU_OT_OBJSET) { 4178 ASSERT0(DMU_OT_IS_ENCRYPTED(ot)); 4179 ASSERT3U(BP_GET_COMPRESS(bp), ==, ZIO_COMPRESS_OFF); 4180 BP_SET_CRYPT(bp, B_TRUE); 4181 VERIFY0(spa_do_crypt_objset_mac_abd(B_TRUE, spa, dsobj, 4182 zio->io_abd, psize, BP_SHOULD_BYTESWAP(bp))); 4183 return (zio); 4184 } 4185 4186 /* unencrypted object types are only authenticated with a MAC */ 4187 if (!DMU_OT_IS_ENCRYPTED(ot)) { 4188 BP_SET_CRYPT(bp, B_TRUE); 4189 VERIFY0(spa_do_crypt_mac_abd(B_TRUE, spa, dsobj, 4190 zio->io_abd, psize, mac)); 4191 zio_crypt_encode_mac_bp(bp, mac); 4192 return (zio); 4193 } 4194 4195 /* 4196 * Later passes of sync-to-convergence may decide to rewrite data 4197 * in place to avoid more disk reallocations. This presents a problem 4198 * for encryption because this constitutes rewriting the new data with 4199 * the same encryption key and IV. However, this only applies to blocks 4200 * in the MOS (particularly the spacemaps) and we do not encrypt the 4201 * MOS. We assert that the zio is allocating or an intent log write 4202 * to enforce this. 4203 */ 4204 ASSERT(IO_IS_ALLOCATING(zio) || ot == DMU_OT_INTENT_LOG); 4205 ASSERT(BP_GET_LEVEL(bp) == 0 || ot == DMU_OT_INTENT_LOG); 4206 ASSERT(spa_feature_is_active(spa, SPA_FEATURE_ENCRYPTION)); 4207 ASSERT3U(psize, !=, 0); 4208 4209 enc_buf = zio_buf_alloc(psize); 4210 eabd = abd_get_from_buf(enc_buf, psize); 4211 abd_take_ownership_of_buf(eabd, B_TRUE); 4212 4213 /* 4214 * For an explanation of what encryption parameters are stored 4215 * where, see the block comment in zio_crypt.c. 4216 */ 4217 if (ot == DMU_OT_INTENT_LOG) { 4218 zio_crypt_decode_params_bp(bp, salt, iv); 4219 } else { 4220 BP_SET_CRYPT(bp, B_TRUE); 4221 } 4222 4223 /* Perform the encryption. This should not fail */ 4224 VERIFY0(spa_do_crypt_abd(B_TRUE, spa, &zio->io_bookmark, 4225 BP_GET_TYPE(bp), BP_GET_DEDUP(bp), BP_SHOULD_BYTESWAP(bp), 4226 salt, iv, mac, psize, zio->io_abd, eabd, &no_crypt)); 4227 4228 /* encode encryption metadata into the bp */ 4229 if (ot == DMU_OT_INTENT_LOG) { 4230 /* 4231 * ZIL blocks store the MAC in the embedded checksum, so the 4232 * transform must always be applied. 4233 */ 4234 zio_crypt_encode_mac_zil(enc_buf, mac); 4235 zio_push_transform(zio, eabd, psize, psize, NULL); 4236 } else { 4237 BP_SET_CRYPT(bp, B_TRUE); 4238 zio_crypt_encode_params_bp(bp, salt, iv); 4239 zio_crypt_encode_mac_bp(bp, mac); 4240 4241 if (no_crypt) { 4242 ASSERT3U(ot, ==, DMU_OT_DNODE); 4243 abd_free(eabd); 4244 } else { 4245 zio_push_transform(zio, eabd, psize, psize, NULL); 4246 } 4247 } 4248 4249 return (zio); 4250 } 4251 4252 /* 4253 * ========================================================================== 4254 * Generate and verify checksums 4255 * ========================================================================== 4256 */ 4257 static zio_t * 4258 zio_checksum_generate(zio_t *zio) 4259 { 4260 blkptr_t *bp = zio->io_bp; 4261 enum zio_checksum checksum; 4262 4263 if (bp == NULL) { 4264 /* 4265 * This is zio_write_phys(). 4266 * We're either generating a label checksum, or none at all. 4267 */ 4268 checksum = zio->io_prop.zp_checksum; 4269 4270 if (checksum == ZIO_CHECKSUM_OFF) 4271 return (zio); 4272 4273 ASSERT(checksum == ZIO_CHECKSUM_LABEL); 4274 } else { 4275 if (BP_IS_GANG(bp) && zio->io_child_type == ZIO_CHILD_GANG) { 4276 ASSERT(!IO_IS_ALLOCATING(zio)); 4277 checksum = ZIO_CHECKSUM_GANG_HEADER; 4278 } else { 4279 checksum = BP_GET_CHECKSUM(bp); 4280 } 4281 } 4282 4283 zio_checksum_compute(zio, checksum, zio->io_abd, zio->io_size); 4284 4285 return (zio); 4286 } 4287 4288 static zio_t * 4289 zio_checksum_verify(zio_t *zio) 4290 { 4291 zio_bad_cksum_t info; 4292 blkptr_t *bp = zio->io_bp; 4293 int error; 4294 4295 ASSERT(zio->io_vd != NULL); 4296 4297 if (bp == NULL) { 4298 /* 4299 * This is zio_read_phys(). 4300 * We're either verifying a label checksum, or nothing at all. 4301 */ 4302 if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF) 4303 return (zio); 4304 4305 ASSERT3U(zio->io_prop.zp_checksum, ==, ZIO_CHECKSUM_LABEL); 4306 } 4307 4308 if ((error = zio_checksum_error(zio, &info)) != 0) { 4309 zio->io_error = error; 4310 if (error == ECKSUM && 4311 !(zio->io_flags & ZIO_FLAG_SPECULATIVE)) { 4312 (void) zfs_ereport_start_checksum(zio->io_spa, 4313 zio->io_vd, &zio->io_bookmark, zio, 4314 zio->io_offset, zio->io_size, &info); 4315 mutex_enter(&zio->io_vd->vdev_stat_lock); 4316 zio->io_vd->vdev_stat.vs_checksum_errors++; 4317 mutex_exit(&zio->io_vd->vdev_stat_lock); 4318 } 4319 } 4320 4321 return (zio); 4322 } 4323 4324 /* 4325 * Called by RAID-Z to ensure we don't compute the checksum twice. 4326 */ 4327 void 4328 zio_checksum_verified(zio_t *zio) 4329 { 4330 zio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY; 4331 } 4332 4333 /* 4334 * ========================================================================== 4335 * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other. 4336 * An error of 0 indicates success. ENXIO indicates whole-device failure, 4337 * which may be transient (e.g. unplugged) or permanent. ECKSUM and EIO 4338 * indicate errors that are specific to one I/O, and most likely permanent. 4339 * Any other error is presumed to be worse because we weren't expecting it. 4340 * ========================================================================== 4341 */ 4342 int 4343 zio_worst_error(int e1, int e2) 4344 { 4345 static int zio_error_rank[] = { 0, ENXIO, ECKSUM, EIO }; 4346 int r1, r2; 4347 4348 for (r1 = 0; r1 < sizeof (zio_error_rank) / sizeof (int); r1++) 4349 if (e1 == zio_error_rank[r1]) 4350 break; 4351 4352 for (r2 = 0; r2 < sizeof (zio_error_rank) / sizeof (int); r2++) 4353 if (e2 == zio_error_rank[r2]) 4354 break; 4355 4356 return (r1 > r2 ? e1 : e2); 4357 } 4358 4359 /* 4360 * ========================================================================== 4361 * I/O completion 4362 * ========================================================================== 4363 */ 4364 static zio_t * 4365 zio_ready(zio_t *zio) 4366 { 4367 blkptr_t *bp = zio->io_bp; 4368 zio_t *pio, *pio_next; 4369 zio_link_t *zl = NULL; 4370 4371 if (zio_wait_for_children(zio, ZIO_CHILD_GANG_BIT | ZIO_CHILD_DDT_BIT, 4372 ZIO_WAIT_READY)) { 4373 return (NULL); 4374 } 4375 4376 if (zio->io_ready) { 4377 ASSERT(IO_IS_ALLOCATING(zio)); 4378 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp) || 4379 (zio->io_flags & ZIO_FLAG_NOPWRITE)); 4380 ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0); 4381 4382 zio->io_ready(zio); 4383 } 4384 4385 if (bp != NULL && bp != &zio->io_bp_copy) 4386 zio->io_bp_copy = *bp; 4387 4388 if (zio->io_error != 0) { 4389 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE; 4390 4391 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 4392 ASSERT(IO_IS_ALLOCATING(zio)); 4393 ASSERT(zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 4394 ASSERT(zio->io_metaslab_class != NULL); 4395 4396 /* 4397 * We were unable to allocate anything, unreserve and 4398 * issue the next I/O to allocate. 4399 */ 4400 metaslab_class_throttle_unreserve( 4401 zio->io_metaslab_class, zio->io_prop.zp_copies, 4402 zio->io_allocator, zio); 4403 zio_allocate_dispatch(zio->io_spa, zio->io_allocator); 4404 } 4405 } 4406 4407 mutex_enter(&zio->io_lock); 4408 zio->io_state[ZIO_WAIT_READY] = 1; 4409 pio = zio_walk_parents(zio, &zl); 4410 mutex_exit(&zio->io_lock); 4411 4412 /* 4413 * As we notify zio's parents, new parents could be added. 4414 * New parents go to the head of zio's io_parent_list, however, 4415 * so we will (correctly) not notify them. The remainder of zio's 4416 * io_parent_list, from 'pio_next' onward, cannot change because 4417 * all parents must wait for us to be done before they can be done. 4418 */ 4419 for (; pio != NULL; pio = pio_next) { 4420 pio_next = zio_walk_parents(zio, &zl); 4421 zio_notify_parent(pio, zio, ZIO_WAIT_READY, NULL); 4422 } 4423 4424 if (zio->io_flags & ZIO_FLAG_NODATA) { 4425 if (BP_IS_GANG(bp)) { 4426 zio->io_flags &= ~ZIO_FLAG_NODATA; 4427 } else { 4428 ASSERT((uintptr_t)zio->io_abd < SPA_MAXBLOCKSIZE); 4429 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES; 4430 } 4431 } 4432 4433 if (zio_injection_enabled && 4434 zio->io_spa->spa_syncing_txg == zio->io_txg) 4435 zio_handle_ignored_writes(zio); 4436 4437 return (zio); 4438 } 4439 4440 /* 4441 * Update the allocation throttle accounting. 4442 */ 4443 static void 4444 zio_dva_throttle_done(zio_t *zio) 4445 { 4446 zio_t *lio __maybe_unused = zio->io_logical; 4447 zio_t *pio = zio_unique_parent(zio); 4448 vdev_t *vd = zio->io_vd; 4449 int flags = METASLAB_ASYNC_ALLOC; 4450 4451 ASSERT3P(zio->io_bp, !=, NULL); 4452 ASSERT3U(zio->io_type, ==, ZIO_TYPE_WRITE); 4453 ASSERT3U(zio->io_priority, ==, ZIO_PRIORITY_ASYNC_WRITE); 4454 ASSERT3U(zio->io_child_type, ==, ZIO_CHILD_VDEV); 4455 ASSERT(vd != NULL); 4456 ASSERT3P(vd, ==, vd->vdev_top); 4457 ASSERT(zio_injection_enabled || !(zio->io_flags & ZIO_FLAG_IO_RETRY)); 4458 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REPAIR)); 4459 ASSERT(zio->io_flags & ZIO_FLAG_IO_ALLOCATING); 4460 ASSERT(!(lio->io_flags & ZIO_FLAG_IO_REWRITE)); 4461 ASSERT(!(lio->io_orig_flags & ZIO_FLAG_NODATA)); 4462 4463 /* 4464 * Parents of gang children can have two flavors -- ones that 4465 * allocated the gang header (will have ZIO_FLAG_IO_REWRITE set) 4466 * and ones that allocated the constituent blocks. The allocation 4467 * throttle needs to know the allocating parent zio so we must find 4468 * it here. 4469 */ 4470 if (pio->io_child_type == ZIO_CHILD_GANG) { 4471 /* 4472 * If our parent is a rewrite gang child then our grandparent 4473 * would have been the one that performed the allocation. 4474 */ 4475 if (pio->io_flags & ZIO_FLAG_IO_REWRITE) 4476 pio = zio_unique_parent(pio); 4477 flags |= METASLAB_GANG_CHILD; 4478 } 4479 4480 ASSERT(IO_IS_ALLOCATING(pio)); 4481 ASSERT3P(zio, !=, zio->io_logical); 4482 ASSERT(zio->io_logical != NULL); 4483 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REPAIR)); 4484 ASSERT0(zio->io_flags & ZIO_FLAG_NOPWRITE); 4485 ASSERT(zio->io_metaslab_class != NULL); 4486 4487 mutex_enter(&pio->io_lock); 4488 metaslab_group_alloc_decrement(zio->io_spa, vd->vdev_id, pio, flags, 4489 pio->io_allocator, B_TRUE); 4490 mutex_exit(&pio->io_lock); 4491 4492 metaslab_class_throttle_unreserve(zio->io_metaslab_class, 1, 4493 pio->io_allocator, pio); 4494 4495 /* 4496 * Call into the pipeline to see if there is more work that 4497 * needs to be done. If there is work to be done it will be 4498 * dispatched to another taskq thread. 4499 */ 4500 zio_allocate_dispatch(zio->io_spa, pio->io_allocator); 4501 } 4502 4503 static zio_t * 4504 zio_done(zio_t *zio) 4505 { 4506 /* 4507 * Always attempt to keep stack usage minimal here since 4508 * we can be called recursively up to 19 levels deep. 4509 */ 4510 const uint64_t psize = zio->io_size; 4511 zio_t *pio, *pio_next; 4512 zio_link_t *zl = NULL; 4513 4514 /* 4515 * If our children haven't all completed, 4516 * wait for them and then repeat this pipeline stage. 4517 */ 4518 if (zio_wait_for_children(zio, ZIO_CHILD_ALL_BITS, ZIO_WAIT_DONE)) { 4519 return (NULL); 4520 } 4521 4522 /* 4523 * If the allocation throttle is enabled, then update the accounting. 4524 * We only track child I/Os that are part of an allocating async 4525 * write. We must do this since the allocation is performed 4526 * by the logical I/O but the actual write is done by child I/Os. 4527 */ 4528 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING && 4529 zio->io_child_type == ZIO_CHILD_VDEV) { 4530 ASSERT(zio->io_metaslab_class != NULL); 4531 ASSERT(zio->io_metaslab_class->mc_alloc_throttle_enabled); 4532 zio_dva_throttle_done(zio); 4533 } 4534 4535 /* 4536 * If the allocation throttle is enabled, verify that 4537 * we have decremented the refcounts for every I/O that was throttled. 4538 */ 4539 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING) { 4540 ASSERT(zio->io_type == ZIO_TYPE_WRITE); 4541 ASSERT(zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE); 4542 ASSERT(zio->io_bp != NULL); 4543 4544 metaslab_group_alloc_verify(zio->io_spa, zio->io_bp, zio, 4545 zio->io_allocator); 4546 VERIFY(zfs_refcount_not_held(&zio->io_metaslab_class-> 4547 mc_allocator[zio->io_allocator].mca_alloc_slots, zio)); 4548 } 4549 4550 4551 for (int c = 0; c < ZIO_CHILD_TYPES; c++) 4552 for (int w = 0; w < ZIO_WAIT_TYPES; w++) 4553 ASSERT(zio->io_children[c][w] == 0); 4554 4555 if (zio->io_bp != NULL && !BP_IS_EMBEDDED(zio->io_bp)) { 4556 ASSERT(zio->io_bp->blk_pad[0] == 0); 4557 ASSERT(zio->io_bp->blk_pad[1] == 0); 4558 ASSERT(bcmp(zio->io_bp, &zio->io_bp_copy, 4559 sizeof (blkptr_t)) == 0 || 4560 (zio->io_bp == zio_unique_parent(zio)->io_bp)); 4561 if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(zio->io_bp) && 4562 zio->io_bp_override == NULL && 4563 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) { 4564 ASSERT3U(zio->io_prop.zp_copies, <=, 4565 BP_GET_NDVAS(zio->io_bp)); 4566 ASSERT(BP_COUNT_GANG(zio->io_bp) == 0 || 4567 (BP_COUNT_GANG(zio->io_bp) == 4568 BP_GET_NDVAS(zio->io_bp))); 4569 } 4570 if (zio->io_flags & ZIO_FLAG_NOPWRITE) 4571 VERIFY(BP_EQUAL(zio->io_bp, &zio->io_bp_orig)); 4572 } 4573 4574 /* 4575 * If there were child vdev/gang/ddt errors, they apply to us now. 4576 */ 4577 zio_inherit_child_errors(zio, ZIO_CHILD_VDEV); 4578 zio_inherit_child_errors(zio, ZIO_CHILD_GANG); 4579 zio_inherit_child_errors(zio, ZIO_CHILD_DDT); 4580 4581 /* 4582 * If the I/O on the transformed data was successful, generate any 4583 * checksum reports now while we still have the transformed data. 4584 */ 4585 if (zio->io_error == 0) { 4586 while (zio->io_cksum_report != NULL) { 4587 zio_cksum_report_t *zcr = zio->io_cksum_report; 4588 uint64_t align = zcr->zcr_align; 4589 uint64_t asize = P2ROUNDUP(psize, align); 4590 abd_t *adata = zio->io_abd; 4591 4592 if (adata != NULL && asize != psize) { 4593 adata = abd_alloc(asize, B_TRUE); 4594 abd_copy(adata, zio->io_abd, psize); 4595 abd_zero_off(adata, psize, asize - psize); 4596 } 4597 4598 zio->io_cksum_report = zcr->zcr_next; 4599 zcr->zcr_next = NULL; 4600 zcr->zcr_finish(zcr, adata); 4601 zfs_ereport_free_checksum(zcr); 4602 4603 if (adata != NULL && asize != psize) 4604 abd_free(adata); 4605 } 4606 } 4607 4608 zio_pop_transforms(zio); /* note: may set zio->io_error */ 4609 4610 vdev_stat_update(zio, psize); 4611 4612 /* 4613 * If this I/O is attached to a particular vdev is slow, exceeding 4614 * 30 seconds to complete, post an error described the I/O delay. 4615 * We ignore these errors if the device is currently unavailable. 4616 */ 4617 if (zio->io_delay >= MSEC2NSEC(zio_slow_io_ms)) { 4618 if (zio->io_vd != NULL && !vdev_is_dead(zio->io_vd)) { 4619 /* 4620 * We want to only increment our slow IO counters if 4621 * the IO is valid (i.e. not if the drive is removed). 4622 * 4623 * zfs_ereport_post() will also do these checks, but 4624 * it can also ratelimit and have other failures, so we 4625 * need to increment the slow_io counters independent 4626 * of it. 4627 */ 4628 if (zfs_ereport_is_valid(FM_EREPORT_ZFS_DELAY, 4629 zio->io_spa, zio->io_vd, zio)) { 4630 mutex_enter(&zio->io_vd->vdev_stat_lock); 4631 zio->io_vd->vdev_stat.vs_slow_ios++; 4632 mutex_exit(&zio->io_vd->vdev_stat_lock); 4633 4634 (void) zfs_ereport_post(FM_EREPORT_ZFS_DELAY, 4635 zio->io_spa, zio->io_vd, &zio->io_bookmark, 4636 zio, 0); 4637 } 4638 } 4639 } 4640 4641 if (zio->io_error) { 4642 /* 4643 * If this I/O is attached to a particular vdev, 4644 * generate an error message describing the I/O failure 4645 * at the block level. We ignore these errors if the 4646 * device is currently unavailable. 4647 */ 4648 if (zio->io_error != ECKSUM && zio->io_vd != NULL && 4649 !vdev_is_dead(zio->io_vd)) { 4650 int ret = zfs_ereport_post(FM_EREPORT_ZFS_IO, 4651 zio->io_spa, zio->io_vd, &zio->io_bookmark, zio, 0); 4652 if (ret != EALREADY) { 4653 mutex_enter(&zio->io_vd->vdev_stat_lock); 4654 if (zio->io_type == ZIO_TYPE_READ) 4655 zio->io_vd->vdev_stat.vs_read_errors++; 4656 else if (zio->io_type == ZIO_TYPE_WRITE) 4657 zio->io_vd->vdev_stat.vs_write_errors++; 4658 mutex_exit(&zio->io_vd->vdev_stat_lock); 4659 } 4660 } 4661 4662 if ((zio->io_error == EIO || !(zio->io_flags & 4663 (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) && 4664 zio == zio->io_logical) { 4665 /* 4666 * For logical I/O requests, tell the SPA to log the 4667 * error and generate a logical data ereport. 4668 */ 4669 spa_log_error(zio->io_spa, &zio->io_bookmark); 4670 (void) zfs_ereport_post(FM_EREPORT_ZFS_DATA, 4671 zio->io_spa, NULL, &zio->io_bookmark, zio, 0); 4672 } 4673 } 4674 4675 if (zio->io_error && zio == zio->io_logical) { 4676 /* 4677 * Determine whether zio should be reexecuted. This will 4678 * propagate all the way to the root via zio_notify_parent(). 4679 */ 4680 ASSERT(zio->io_vd == NULL && zio->io_bp != NULL); 4681 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 4682 4683 if (IO_IS_ALLOCATING(zio) && 4684 !(zio->io_flags & ZIO_FLAG_CANFAIL)) { 4685 if (zio->io_error != ENOSPC) 4686 zio->io_reexecute |= ZIO_REEXECUTE_NOW; 4687 else 4688 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 4689 } 4690 4691 if ((zio->io_type == ZIO_TYPE_READ || 4692 zio->io_type == ZIO_TYPE_FREE) && 4693 !(zio->io_flags & ZIO_FLAG_SCAN_THREAD) && 4694 zio->io_error == ENXIO && 4695 spa_load_state(zio->io_spa) == SPA_LOAD_NONE && 4696 spa_get_failmode(zio->io_spa) != ZIO_FAILURE_MODE_CONTINUE) 4697 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 4698 4699 if (!(zio->io_flags & ZIO_FLAG_CANFAIL) && !zio->io_reexecute) 4700 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND; 4701 4702 /* 4703 * Here is a possibly good place to attempt to do 4704 * either combinatorial reconstruction or error correction 4705 * based on checksums. It also might be a good place 4706 * to send out preliminary ereports before we suspend 4707 * processing. 4708 */ 4709 } 4710 4711 /* 4712 * If there were logical child errors, they apply to us now. 4713 * We defer this until now to avoid conflating logical child 4714 * errors with errors that happened to the zio itself when 4715 * updating vdev stats and reporting FMA events above. 4716 */ 4717 zio_inherit_child_errors(zio, ZIO_CHILD_LOGICAL); 4718 4719 if ((zio->io_error || zio->io_reexecute) && 4720 IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio && 4721 !(zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE))) 4722 zio_dva_unallocate(zio, zio->io_gang_tree, zio->io_bp); 4723 4724 zio_gang_tree_free(&zio->io_gang_tree); 4725 4726 /* 4727 * Godfather I/Os should never suspend. 4728 */ 4729 if ((zio->io_flags & ZIO_FLAG_GODFATHER) && 4730 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) 4731 zio->io_reexecute &= ~ZIO_REEXECUTE_SUSPEND; 4732 4733 if (zio->io_reexecute) { 4734 /* 4735 * This is a logical I/O that wants to reexecute. 4736 * 4737 * Reexecute is top-down. When an i/o fails, if it's not 4738 * the root, it simply notifies its parent and sticks around. 4739 * The parent, seeing that it still has children in zio_done(), 4740 * does the same. This percolates all the way up to the root. 4741 * The root i/o will reexecute or suspend the entire tree. 4742 * 4743 * This approach ensures that zio_reexecute() honors 4744 * all the original i/o dependency relationships, e.g. 4745 * parents not executing until children are ready. 4746 */ 4747 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL); 4748 4749 zio->io_gang_leader = NULL; 4750 4751 mutex_enter(&zio->io_lock); 4752 zio->io_state[ZIO_WAIT_DONE] = 1; 4753 mutex_exit(&zio->io_lock); 4754 4755 /* 4756 * "The Godfather" I/O monitors its children but is 4757 * not a true parent to them. It will track them through 4758 * the pipeline but severs its ties whenever they get into 4759 * trouble (e.g. suspended). This allows "The Godfather" 4760 * I/O to return status without blocking. 4761 */ 4762 zl = NULL; 4763 for (pio = zio_walk_parents(zio, &zl); pio != NULL; 4764 pio = pio_next) { 4765 zio_link_t *remove_zl = zl; 4766 pio_next = zio_walk_parents(zio, &zl); 4767 4768 if ((pio->io_flags & ZIO_FLAG_GODFATHER) && 4769 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) { 4770 zio_remove_child(pio, zio, remove_zl); 4771 /* 4772 * This is a rare code path, so we don't 4773 * bother with "next_to_execute". 4774 */ 4775 zio_notify_parent(pio, zio, ZIO_WAIT_DONE, 4776 NULL); 4777 } 4778 } 4779 4780 if ((pio = zio_unique_parent(zio)) != NULL) { 4781 /* 4782 * We're not a root i/o, so there's nothing to do 4783 * but notify our parent. Don't propagate errors 4784 * upward since we haven't permanently failed yet. 4785 */ 4786 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER)); 4787 zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE; 4788 /* 4789 * This is a rare code path, so we don't bother with 4790 * "next_to_execute". 4791 */ 4792 zio_notify_parent(pio, zio, ZIO_WAIT_DONE, NULL); 4793 } else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) { 4794 /* 4795 * We'd fail again if we reexecuted now, so suspend 4796 * until conditions improve (e.g. device comes online). 4797 */ 4798 zio_suspend(zio->io_spa, zio, ZIO_SUSPEND_IOERR); 4799 } else { 4800 /* 4801 * Reexecution is potentially a huge amount of work. 4802 * Hand it off to the otherwise-unused claim taskq. 4803 */ 4804 ASSERT(taskq_empty_ent(&zio->io_tqent)); 4805 spa_taskq_dispatch_ent(zio->io_spa, 4806 ZIO_TYPE_CLAIM, ZIO_TASKQ_ISSUE, 4807 zio_reexecute, zio, 0, &zio->io_tqent); 4808 } 4809 return (NULL); 4810 } 4811 4812 ASSERT(zio->io_child_count == 0); 4813 ASSERT(zio->io_reexecute == 0); 4814 ASSERT(zio->io_error == 0 || (zio->io_flags & ZIO_FLAG_CANFAIL)); 4815 4816 /* 4817 * Report any checksum errors, since the I/O is complete. 4818 */ 4819 while (zio->io_cksum_report != NULL) { 4820 zio_cksum_report_t *zcr = zio->io_cksum_report; 4821 zio->io_cksum_report = zcr->zcr_next; 4822 zcr->zcr_next = NULL; 4823 zcr->zcr_finish(zcr, NULL); 4824 zfs_ereport_free_checksum(zcr); 4825 } 4826 4827 if (zio->io_flags & ZIO_FLAG_FASTWRITE && zio->io_bp && 4828 !BP_IS_HOLE(zio->io_bp) && !BP_IS_EMBEDDED(zio->io_bp) && 4829 !(zio->io_flags & ZIO_FLAG_NOPWRITE)) { 4830 metaslab_fastwrite_unmark(zio->io_spa, zio->io_bp); 4831 } 4832 4833 /* 4834 * It is the responsibility of the done callback to ensure that this 4835 * particular zio is no longer discoverable for adoption, and as 4836 * such, cannot acquire any new parents. 4837 */ 4838 if (zio->io_done) 4839 zio->io_done(zio); 4840 4841 mutex_enter(&zio->io_lock); 4842 zio->io_state[ZIO_WAIT_DONE] = 1; 4843 mutex_exit(&zio->io_lock); 4844 4845 /* 4846 * We are done executing this zio. We may want to execute a parent 4847 * next. See the comment in zio_notify_parent(). 4848 */ 4849 zio_t *next_to_execute = NULL; 4850 zl = NULL; 4851 for (pio = zio_walk_parents(zio, &zl); pio != NULL; pio = pio_next) { 4852 zio_link_t *remove_zl = zl; 4853 pio_next = zio_walk_parents(zio, &zl); 4854 zio_remove_child(pio, zio, remove_zl); 4855 zio_notify_parent(pio, zio, ZIO_WAIT_DONE, &next_to_execute); 4856 } 4857 4858 if (zio->io_waiter != NULL) { 4859 mutex_enter(&zio->io_lock); 4860 zio->io_executor = NULL; 4861 cv_broadcast(&zio->io_cv); 4862 mutex_exit(&zio->io_lock); 4863 } else { 4864 zio_destroy(zio); 4865 } 4866 4867 return (next_to_execute); 4868 } 4869 4870 /* 4871 * ========================================================================== 4872 * I/O pipeline definition 4873 * ========================================================================== 4874 */ 4875 static zio_pipe_stage_t *zio_pipeline[] = { 4876 NULL, 4877 zio_read_bp_init, 4878 zio_write_bp_init, 4879 zio_free_bp_init, 4880 zio_issue_async, 4881 zio_write_compress, 4882 zio_encrypt, 4883 zio_checksum_generate, 4884 zio_nop_write, 4885 zio_ddt_read_start, 4886 zio_ddt_read_done, 4887 zio_ddt_write, 4888 zio_ddt_free, 4889 zio_gang_assemble, 4890 zio_gang_issue, 4891 zio_dva_throttle, 4892 zio_dva_allocate, 4893 zio_dva_free, 4894 zio_dva_claim, 4895 zio_ready, 4896 zio_vdev_io_start, 4897 zio_vdev_io_done, 4898 zio_vdev_io_assess, 4899 zio_checksum_verify, 4900 zio_done 4901 }; 4902 4903 4904 4905 4906 /* 4907 * Compare two zbookmark_phys_t's to see which we would reach first in a 4908 * pre-order traversal of the object tree. 4909 * 4910 * This is simple in every case aside from the meta-dnode object. For all other 4911 * objects, we traverse them in order (object 1 before object 2, and so on). 4912 * However, all of these objects are traversed while traversing object 0, since 4913 * the data it points to is the list of objects. Thus, we need to convert to a 4914 * canonical representation so we can compare meta-dnode bookmarks to 4915 * non-meta-dnode bookmarks. 4916 * 4917 * We do this by calculating "equivalents" for each field of the zbookmark. 4918 * zbookmarks outside of the meta-dnode use their own object and level, and 4919 * calculate the level 0 equivalent (the first L0 blkid that is contained in the 4920 * blocks this bookmark refers to) by multiplying their blkid by their span 4921 * (the number of L0 blocks contained within one block at their level). 4922 * zbookmarks inside the meta-dnode calculate their object equivalent 4923 * (which is L0equiv * dnodes per data block), use 0 for their L0equiv, and use 4924 * level + 1<<31 (any value larger than a level could ever be) for their level. 4925 * This causes them to always compare before a bookmark in their object 4926 * equivalent, compare appropriately to bookmarks in other objects, and to 4927 * compare appropriately to other bookmarks in the meta-dnode. 4928 */ 4929 int 4930 zbookmark_compare(uint16_t dbss1, uint8_t ibs1, uint16_t dbss2, uint8_t ibs2, 4931 const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2) 4932 { 4933 /* 4934 * These variables represent the "equivalent" values for the zbookmark, 4935 * after converting zbookmarks inside the meta dnode to their 4936 * normal-object equivalents. 4937 */ 4938 uint64_t zb1obj, zb2obj; 4939 uint64_t zb1L0, zb2L0; 4940 uint64_t zb1level, zb2level; 4941 4942 if (zb1->zb_object == zb2->zb_object && 4943 zb1->zb_level == zb2->zb_level && 4944 zb1->zb_blkid == zb2->zb_blkid) 4945 return (0); 4946 4947 IMPLY(zb1->zb_level > 0, ibs1 >= SPA_MINBLOCKSHIFT); 4948 IMPLY(zb2->zb_level > 0, ibs2 >= SPA_MINBLOCKSHIFT); 4949 4950 /* 4951 * BP_SPANB calculates the span in blocks. 4952 */ 4953 zb1L0 = (zb1->zb_blkid) * BP_SPANB(ibs1, zb1->zb_level); 4954 zb2L0 = (zb2->zb_blkid) * BP_SPANB(ibs2, zb2->zb_level); 4955 4956 if (zb1->zb_object == DMU_META_DNODE_OBJECT) { 4957 zb1obj = zb1L0 * (dbss1 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT)); 4958 zb1L0 = 0; 4959 zb1level = zb1->zb_level + COMPARE_META_LEVEL; 4960 } else { 4961 zb1obj = zb1->zb_object; 4962 zb1level = zb1->zb_level; 4963 } 4964 4965 if (zb2->zb_object == DMU_META_DNODE_OBJECT) { 4966 zb2obj = zb2L0 * (dbss2 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT)); 4967 zb2L0 = 0; 4968 zb2level = zb2->zb_level + COMPARE_META_LEVEL; 4969 } else { 4970 zb2obj = zb2->zb_object; 4971 zb2level = zb2->zb_level; 4972 } 4973 4974 /* Now that we have a canonical representation, do the comparison. */ 4975 if (zb1obj != zb2obj) 4976 return (zb1obj < zb2obj ? -1 : 1); 4977 else if (zb1L0 != zb2L0) 4978 return (zb1L0 < zb2L0 ? -1 : 1); 4979 else if (zb1level != zb2level) 4980 return (zb1level > zb2level ? -1 : 1); 4981 /* 4982 * This can (theoretically) happen if the bookmarks have the same object 4983 * and level, but different blkids, if the block sizes are not the same. 4984 * There is presently no way to change the indirect block sizes 4985 */ 4986 return (0); 4987 } 4988 4989 /* 4990 * This function checks the following: given that last_block is the place that 4991 * our traversal stopped last time, does that guarantee that we've visited 4992 * every node under subtree_root? Therefore, we can't just use the raw output 4993 * of zbookmark_compare. We have to pass in a modified version of 4994 * subtree_root; by incrementing the block id, and then checking whether 4995 * last_block is before or equal to that, we can tell whether or not having 4996 * visited last_block implies that all of subtree_root's children have been 4997 * visited. 4998 */ 4999 boolean_t 5000 zbookmark_subtree_completed(const dnode_phys_t *dnp, 5001 const zbookmark_phys_t *subtree_root, const zbookmark_phys_t *last_block) 5002 { 5003 zbookmark_phys_t mod_zb = *subtree_root; 5004 mod_zb.zb_blkid++; 5005 ASSERT(last_block->zb_level == 0); 5006 5007 /* The objset_phys_t isn't before anything. */ 5008 if (dnp == NULL) 5009 return (B_FALSE); 5010 5011 /* 5012 * We pass in 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT) for the 5013 * data block size in sectors, because that variable is only used if 5014 * the bookmark refers to a block in the meta-dnode. Since we don't 5015 * know without examining it what object it refers to, and there's no 5016 * harm in passing in this value in other cases, we always pass it in. 5017 * 5018 * We pass in 0 for the indirect block size shift because zb2 must be 5019 * level 0. The indirect block size is only used to calculate the span 5020 * of the bookmark, but since the bookmark must be level 0, the span is 5021 * always 1, so the math works out. 5022 * 5023 * If you make changes to how the zbookmark_compare code works, be sure 5024 * to make sure that this code still works afterwards. 5025 */ 5026 return (zbookmark_compare(dnp->dn_datablkszsec, dnp->dn_indblkshift, 5027 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT), 0, &mod_zb, 5028 last_block) <= 0); 5029 } 5030 5031 EXPORT_SYMBOL(zio_type_name); 5032 EXPORT_SYMBOL(zio_buf_alloc); 5033 EXPORT_SYMBOL(zio_data_buf_alloc); 5034 EXPORT_SYMBOL(zio_buf_free); 5035 EXPORT_SYMBOL(zio_data_buf_free); 5036 5037 /* BEGIN CSTYLED */ 5038 ZFS_MODULE_PARAM(zfs_zio, zio_, slow_io_ms, INT, ZMOD_RW, 5039 "Max I/O completion time (milliseconds) before marking it as slow"); 5040 5041 ZFS_MODULE_PARAM(zfs_zio, zio_, requeue_io_start_cut_in_line, INT, ZMOD_RW, 5042 "Prioritize requeued I/O"); 5043 5044 ZFS_MODULE_PARAM(zfs, zfs_, sync_pass_deferred_free, INT, ZMOD_RW, 5045 "Defer frees starting in this pass"); 5046 5047 ZFS_MODULE_PARAM(zfs, zfs_, sync_pass_dont_compress, INT, ZMOD_RW, 5048 "Don't compress starting in this pass"); 5049 5050 ZFS_MODULE_PARAM(zfs, zfs_, sync_pass_rewrite, INT, ZMOD_RW, 5051 "Rewrite new bps starting in this pass"); 5052 5053 ZFS_MODULE_PARAM(zfs_zio, zio_, dva_throttle_enabled, INT, ZMOD_RW, 5054 "Throttle block allocations in the ZIO pipeline"); 5055 5056 ZFS_MODULE_PARAM(zfs_zio, zio_, deadman_log_all, INT, ZMOD_RW, 5057 "Log all slow ZIOs, not just those with vdevs"); 5058 /* END CSTYLED */ 5059