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, 2018 by Delphix. All rights reserved.
24 * Copyright (c) 2011 Nexenta Systems, Inc. All rights reserved.
25 * Copyright (c) 2014 Integros [integros.com]
26 * Copyright (c) 2017, Intel Corporation.
27 * Copyright 2020 Joyent, Inc.
28 */
29
30 #include <sys/sysmacros.h>
31 #include <sys/zfs_context.h>
32 #include <sys/fm/fs/zfs.h>
33 #include <sys/spa.h>
34 #include <sys/txg.h>
35 #include <sys/spa_impl.h>
36 #include <sys/vdev_impl.h>
37 #include <sys/vdev_trim.h>
38 #include <sys/zio_impl.h>
39 #include <sys/zio_compress.h>
40 #include <sys/zio_checksum.h>
41 #include <sys/dmu_objset.h>
42 #include <sys/arc.h>
43 #include <sys/ddt.h>
44 #include <sys/blkptr.h>
45 #include <sys/zfeature.h>
46 #include <sys/time.h>
47 #include <sys/dsl_scan.h>
48 #include <sys/metaslab_impl.h>
49 #include <sys/abd.h>
50 #include <sys/cityhash.h>
51 #include <sys/dsl_crypt.h>
52
53 /*
54 * ==========================================================================
55 * I/O type descriptions
56 * ==========================================================================
57 */
58 const char *zio_type_name[ZIO_TYPES] = {
59 "zio_null", "zio_read", "zio_write", "zio_free", "zio_claim",
60 "zio_ioctl", "z_trim"
61 };
62
63 boolean_t zio_dva_throttle_enabled = B_TRUE;
64
65 /*
66 * ==========================================================================
67 * I/O kmem caches
68 * ==========================================================================
69 */
70 kmem_cache_t *zio_cache;
71 kmem_cache_t *zio_link_cache;
72 kmem_cache_t *zio_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT];
73 kmem_cache_t *zio_data_buf_cache[SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT];
74
75 #ifdef _KERNEL
76 extern vmem_t *zio_alloc_arena;
77 #endif
78
79 #define ZIO_PIPELINE_CONTINUE 0x100
80 #define ZIO_PIPELINE_STOP 0x101
81
82 /* Mark IOs as "slow" if they take longer than 30 seconds */
83 int zio_slow_io_ms = (30 * MILLISEC);
84
85 #define BP_SPANB(indblkshift, level) \
86 (((uint64_t)1) << ((level) * ((indblkshift) - SPA_BLKPTRSHIFT)))
87 #define COMPARE_META_LEVEL 0x80000000ul
88 /*
89 * The following actions directly effect the spa's sync-to-convergence logic.
90 * The values below define the sync pass when we start performing the action.
91 * Care should be taken when changing these values as they directly impact
92 * spa_sync() performance. Tuning these values may introduce subtle performance
93 * pathologies and should only be done in the context of performance analysis.
94 * These tunables will eventually be removed and replaced with #defines once
95 * enough analysis has been done to determine optimal values.
96 *
97 * The 'zfs_sync_pass_deferred_free' pass must be greater than 1 to ensure that
98 * regular blocks are not deferred.
99 */
100 int zfs_sync_pass_deferred_free = 2; /* defer frees starting in this pass */
101 int zfs_sync_pass_dont_compress = 5; /* don't compress starting in this pass */
102 int zfs_sync_pass_rewrite = 2; /* rewrite new bps starting in this pass */
103
104 /*
105 * An allocating zio is one that either currently has the DVA allocate
106 * stage set or will have it later in its lifetime.
107 */
108 #define IO_IS_ALLOCATING(zio) ((zio)->io_orig_pipeline & ZIO_STAGE_DVA_ALLOCATE)
109
110 boolean_t zio_requeue_io_start_cut_in_line = B_TRUE;
111
112 #ifdef ZFS_DEBUG
113 int zio_buf_debug_limit = 16384;
114 #else
115 int zio_buf_debug_limit = 0;
116 #endif
117
118 static void zio_taskq_dispatch(zio_t *, zio_taskq_type_t, boolean_t);
119
120 void
121 zio_init(void)
122 {
123 size_t c;
124 vmem_t *data_alloc_arena = NULL;
125
126 #ifdef _KERNEL
127 data_alloc_arena = zio_alloc_arena;
128 #endif
129 zio_cache = kmem_cache_create("zio_cache",
130 sizeof (zio_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
131 zio_link_cache = kmem_cache_create("zio_link_cache",
132 sizeof (zio_link_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
133
134 /*
135 * For small buffers, we want a cache for each multiple of
136 * SPA_MINBLOCKSIZE. For larger buffers, we want a cache
137 * for each quarter-power of 2.
138 */
139 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) {
140 size_t size = (c + 1) << SPA_MINBLOCKSHIFT;
141 size_t p2 = size;
142 size_t align = 0;
143 size_t cflags = (size > zio_buf_debug_limit) ? KMC_NODEBUG : 0;
144
145 while (!ISP2(p2))
146 p2 &= p2 - 1;
147
148 #ifndef _KERNEL
149 /*
150 * If we are using watchpoints, put each buffer on its own page,
151 * to eliminate the performance overhead of trapping to the
152 * kernel when modifying a non-watched buffer that shares the
153 * page with a watched buffer.
154 */
155 if (arc_watch && !IS_P2ALIGNED(size, PAGESIZE))
156 continue;
157 #endif
158 if (size <= 4 * SPA_MINBLOCKSIZE) {
159 align = SPA_MINBLOCKSIZE;
160 } else if (IS_P2ALIGNED(size, p2 >> 2)) {
161 align = MIN(p2 >> 2, PAGESIZE);
162 }
163
164 if (align != 0) {
165 char name[36];
166 (void) sprintf(name, "zio_buf_%lu", (ulong_t)size);
167 zio_buf_cache[c] = kmem_cache_create(name, size,
168 align, NULL, NULL, NULL, NULL, NULL, cflags);
169
170 /*
171 * Since zio_data bufs do not appear in crash dumps, we
172 * pass KMC_NOTOUCH so that no allocator metadata is
173 * stored with the buffers.
174 */
175 (void) sprintf(name, "zio_data_buf_%lu", (ulong_t)size);
176 zio_data_buf_cache[c] = kmem_cache_create(name, size,
177 align, NULL, NULL, NULL, NULL, data_alloc_arena,
178 cflags | KMC_NOTOUCH);
179 }
180 }
181
182 while (--c != 0) {
183 ASSERT(zio_buf_cache[c] != NULL);
184 if (zio_buf_cache[c - 1] == NULL)
185 zio_buf_cache[c - 1] = zio_buf_cache[c];
186
187 ASSERT(zio_data_buf_cache[c] != NULL);
188 if (zio_data_buf_cache[c - 1] == NULL)
189 zio_data_buf_cache[c - 1] = zio_data_buf_cache[c];
190 }
191
192 zio_inject_init();
193 }
194
195 void
196 zio_fini(void)
197 {
198 size_t c;
199 kmem_cache_t *last_cache = NULL;
200 kmem_cache_t *last_data_cache = NULL;
201
202 for (c = 0; c < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; c++) {
203 if (zio_buf_cache[c] != last_cache) {
204 last_cache = zio_buf_cache[c];
205 kmem_cache_destroy(zio_buf_cache[c]);
206 }
207 zio_buf_cache[c] = NULL;
208
209 if (zio_data_buf_cache[c] != last_data_cache) {
210 last_data_cache = zio_data_buf_cache[c];
211 kmem_cache_destroy(zio_data_buf_cache[c]);
212 }
213 zio_data_buf_cache[c] = NULL;
214 }
215
216 kmem_cache_destroy(zio_link_cache);
217 kmem_cache_destroy(zio_cache);
218
219 zio_inject_fini();
220 }
221
222 /*
223 * ==========================================================================
224 * Allocate and free I/O buffers
225 * ==========================================================================
226 */
227
228 /*
229 * Use zio_buf_alloc to allocate ZFS metadata. This data will appear in a
230 * crashdump if the kernel panics, so use it judiciously. Obviously, it's
231 * useful to inspect ZFS metadata, but if possible, we should avoid keeping
232 * excess / transient data in-core during a crashdump.
233 */
234 void *
235 zio_buf_alloc(size_t size)
236 {
237 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
238
239 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
240
241 return (kmem_cache_alloc(zio_buf_cache[c], KM_PUSHPAGE));
242 }
243
244 /*
245 * Use zio_data_buf_alloc to allocate data. The data will not appear in a
246 * crashdump if the kernel panics. This exists so that we will limit the amount
247 * of ZFS data that shows up in a kernel crashdump. (Thus reducing the amount
248 * of kernel heap dumped to disk when the kernel panics)
249 */
250 void *
251 zio_data_buf_alloc(size_t size)
252 {
253 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
254
255 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
256
257 return (kmem_cache_alloc(zio_data_buf_cache[c], KM_PUSHPAGE));
258 }
259
260 void
261 zio_buf_free(void *buf, size_t size)
262 {
263 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
264
265 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
266
267 kmem_cache_free(zio_buf_cache[c], buf);
268 }
269
270 void
271 zio_data_buf_free(void *buf, size_t size)
272 {
273 size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
274
275 VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
276
277 kmem_cache_free(zio_data_buf_cache[c], buf);
278 }
279
280 /* ARGSUSED */
281 static void
282 zio_abd_free(void *abd, size_t size)
283 {
284 abd_free((abd_t *)abd);
285 }
286
287 /*
288 * ==========================================================================
289 * Push and pop I/O transform buffers
290 * ==========================================================================
291 */
292 void
293 zio_push_transform(zio_t *zio, abd_t *data, uint64_t size, uint64_t bufsize,
294 zio_transform_func_t *transform)
295 {
296 zio_transform_t *zt = kmem_alloc(sizeof (zio_transform_t), KM_SLEEP);
297
298 /*
299 * Ensure that anyone expecting this zio to contain a linear ABD isn't
300 * going to get a nasty surprise when they try to access the data.
301 */
302 IMPLY(abd_is_linear(zio->io_abd), abd_is_linear(data));
303
304 zt->zt_orig_abd = zio->io_abd;
305 zt->zt_orig_size = zio->io_size;
306 zt->zt_bufsize = bufsize;
307 zt->zt_transform = transform;
308
309 zt->zt_next = zio->io_transform_stack;
310 zio->io_transform_stack = zt;
311
312 zio->io_abd = data;
313 zio->io_size = size;
314 }
315
316 void
317 zio_pop_transforms(zio_t *zio)
318 {
319 zio_transform_t *zt;
320
321 while ((zt = zio->io_transform_stack) != NULL) {
322 if (zt->zt_transform != NULL)
323 zt->zt_transform(zio,
324 zt->zt_orig_abd, zt->zt_orig_size);
325
326 if (zt->zt_bufsize != 0)
327 abd_free(zio->io_abd);
328
329 zio->io_abd = zt->zt_orig_abd;
330 zio->io_size = zt->zt_orig_size;
331 zio->io_transform_stack = zt->zt_next;
332
333 kmem_free(zt, sizeof (zio_transform_t));
334 }
335 }
336
337 /*
338 * ==========================================================================
339 * I/O transform callbacks for subblocks, decompression, and decryption
340 * ==========================================================================
341 */
342 static void
343 zio_subblock(zio_t *zio, abd_t *data, uint64_t size)
344 {
345 ASSERT(zio->io_size > size);
346
347 if (zio->io_type == ZIO_TYPE_READ)
348 abd_copy(data, zio->io_abd, size);
349 }
350
351 static void
352 zio_decompress(zio_t *zio, abd_t *data, uint64_t size)
353 {
354 if (zio->io_error == 0) {
355 void *tmp = abd_borrow_buf(data, size);
356 int ret = zio_decompress_data(BP_GET_COMPRESS(zio->io_bp),
357 zio->io_abd, tmp, zio->io_size, size);
358 abd_return_buf_copy(data, tmp, size);
359
360 if (ret != 0)
361 zio->io_error = SET_ERROR(EIO);
362 }
363 }
364
365 static void
366 zio_decrypt(zio_t *zio, abd_t *data, uint64_t size)
367 {
368 int ret;
369 void *tmp;
370 blkptr_t *bp = zio->io_bp;
371 spa_t *spa = zio->io_spa;
372 uint64_t dsobj = zio->io_bookmark.zb_objset;
373 uint64_t lsize = BP_GET_LSIZE(bp);
374 dmu_object_type_t ot = BP_GET_TYPE(bp);
375 uint8_t salt[ZIO_DATA_SALT_LEN];
376 uint8_t iv[ZIO_DATA_IV_LEN];
377 uint8_t mac[ZIO_DATA_MAC_LEN];
378 boolean_t no_crypt = B_FALSE;
379
380 ASSERT(BP_USES_CRYPT(bp));
381 ASSERT3U(size, !=, 0);
382
383 if (zio->io_error != 0)
384 return;
385
386 /*
387 * Verify the cksum of MACs stored in an indirect bp. It will always
388 * be possible to verify this since it does not require an encryption
389 * key.
390 */
391 if (BP_HAS_INDIRECT_MAC_CKSUM(bp)) {
392 zio_crypt_decode_mac_bp(bp, mac);
393
394 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF) {
395 /*
396 * We haven't decompressed the data yet, but
397 * zio_crypt_do_indirect_mac_checksum() requires
398 * decompressed data to be able to parse out the MACs
399 * from the indirect block. We decompress it now and
400 * throw away the result after we are finished.
401 */
402 tmp = zio_buf_alloc(lsize);
403 ret = zio_decompress_data(BP_GET_COMPRESS(bp),
404 zio->io_abd, tmp, zio->io_size, lsize);
405 if (ret != 0) {
406 ret = SET_ERROR(EIO);
407 goto error;
408 }
409 ret = zio_crypt_do_indirect_mac_checksum(B_FALSE,
410 tmp, lsize, BP_SHOULD_BYTESWAP(bp), mac);
411 zio_buf_free(tmp, lsize);
412 } else {
413 ret = zio_crypt_do_indirect_mac_checksum_abd(B_FALSE,
414 zio->io_abd, size, BP_SHOULD_BYTESWAP(bp), mac);
415 }
416 abd_copy(data, zio->io_abd, size);
417
418 if (ret != 0)
419 goto error;
420
421 return;
422 }
423
424 /*
425 * If this is an authenticated block, just check the MAC. It would be
426 * nice to separate this out into its own flag, but for the moment
427 * enum zio_flag is out of bits.
428 */
429 if (BP_IS_AUTHENTICATED(bp)) {
430 if (ot == DMU_OT_OBJSET) {
431 ret = spa_do_crypt_objset_mac_abd(B_FALSE, spa,
432 dsobj, zio->io_abd, size, BP_SHOULD_BYTESWAP(bp));
433 } else {
434 zio_crypt_decode_mac_bp(bp, mac);
435 ret = spa_do_crypt_mac_abd(B_FALSE, spa, dsobj,
436 zio->io_abd, size, mac);
437 }
438 abd_copy(data, zio->io_abd, size);
439
440 if (zio_injection_enabled && ot != DMU_OT_DNODE && ret == 0) {
441 ret = zio_handle_decrypt_injection(spa,
442 &zio->io_bookmark, ot, ECKSUM);
443 }
444 if (ret != 0)
445 goto error;
446
447 return;
448 }
449
450 zio_crypt_decode_params_bp(bp, salt, iv);
451
452 if (ot == DMU_OT_INTENT_LOG) {
453 tmp = abd_borrow_buf_copy(zio->io_abd, sizeof (zil_chain_t));
454 zio_crypt_decode_mac_zil(tmp, mac);
455 abd_return_buf(zio->io_abd, tmp, sizeof (zil_chain_t));
456 } else {
457 zio_crypt_decode_mac_bp(bp, mac);
458 }
459
460 ret = spa_do_crypt_abd(B_FALSE, spa, &zio->io_bookmark, BP_GET_TYPE(bp),
461 BP_GET_DEDUP(bp), BP_SHOULD_BYTESWAP(bp), salt, iv, mac, size, data,
462 zio->io_abd, &no_crypt);
463 if (no_crypt)
464 abd_copy(data, zio->io_abd, size);
465
466 if (ret != 0)
467 goto error;
468
469 return;
470
471 error:
472 /* assert that the key was found unless this was speculative */
473 ASSERT(ret != EACCES || (zio->io_flags & ZIO_FLAG_SPECULATIVE));
474
475 /*
476 * If there was a decryption / authentication error return EIO as
477 * the io_error. If this was not a speculative zio, create an ereport.
478 */
479 if (ret == ECKSUM) {
480 zio->io_error = SET_ERROR(EIO);
481 if ((zio->io_flags & ZIO_FLAG_SPECULATIVE) == 0) {
482 spa_log_error(spa, &zio->io_bookmark);
483 zfs_ereport_post(FM_EREPORT_ZFS_AUTHENTICATION,
484 spa, NULL, &zio->io_bookmark, zio, 0, 0);
485 }
486 } else {
487 zio->io_error = ret;
488 }
489 }
490
491 /*
492 * ==========================================================================
493 * I/O parent/child relationships and pipeline interlocks
494 * ==========================================================================
495 */
496 zio_t *
497 zio_walk_parents(zio_t *cio, zio_link_t **zl)
498 {
499 list_t *pl = &cio->io_parent_list;
500
501 *zl = (*zl == NULL) ? list_head(pl) : list_next(pl, *zl);
502 if (*zl == NULL)
503 return (NULL);
504
505 ASSERT((*zl)->zl_child == cio);
506 return ((*zl)->zl_parent);
507 }
508
509 zio_t *
510 zio_walk_children(zio_t *pio, zio_link_t **zl)
511 {
512 list_t *cl = &pio->io_child_list;
513
514 ASSERT(MUTEX_HELD(&pio->io_lock));
515
516 *zl = (*zl == NULL) ? list_head(cl) : list_next(cl, *zl);
517 if (*zl == NULL)
518 return (NULL);
519
520 ASSERT((*zl)->zl_parent == pio);
521 return ((*zl)->zl_child);
522 }
523
524 zio_t *
525 zio_unique_parent(zio_t *cio)
526 {
527 zio_link_t *zl = NULL;
528 zio_t *pio = zio_walk_parents(cio, &zl);
529
530 VERIFY3P(zio_walk_parents(cio, &zl), ==, NULL);
531 return (pio);
532 }
533
534 void
535 zio_add_child(zio_t *pio, zio_t *cio)
536 {
537 zio_link_t *zl = kmem_cache_alloc(zio_link_cache, KM_SLEEP);
538
539 /*
540 * Logical I/Os can have logical, gang, or vdev children.
541 * Gang I/Os can have gang or vdev children.
542 * Vdev I/Os can only have vdev children.
543 * The following ASSERT captures all of these constraints.
544 */
545 ASSERT3S(cio->io_child_type, <=, pio->io_child_type);
546
547 zl->zl_parent = pio;
548 zl->zl_child = cio;
549
550 mutex_enter(&pio->io_lock);
551 mutex_enter(&cio->io_lock);
552
553 ASSERT(pio->io_state[ZIO_WAIT_DONE] == 0);
554
555 for (int w = 0; w < ZIO_WAIT_TYPES; w++)
556 pio->io_children[cio->io_child_type][w] += !cio->io_state[w];
557
558 list_insert_head(&pio->io_child_list, zl);
559 list_insert_head(&cio->io_parent_list, zl);
560
561 pio->io_child_count++;
562 cio->io_parent_count++;
563
564 mutex_exit(&cio->io_lock);
565 mutex_exit(&pio->io_lock);
566 }
567
568 static void
569 zio_remove_child(zio_t *pio, zio_t *cio, zio_link_t *zl)
570 {
571 ASSERT(zl->zl_parent == pio);
572 ASSERT(zl->zl_child == cio);
573
574 mutex_enter(&pio->io_lock);
575 mutex_enter(&cio->io_lock);
576
577 list_remove(&pio->io_child_list, zl);
578 list_remove(&cio->io_parent_list, zl);
579
580 pio->io_child_count--;
581 cio->io_parent_count--;
582
583 mutex_exit(&cio->io_lock);
584 mutex_exit(&pio->io_lock);
585
586 kmem_cache_free(zio_link_cache, zl);
587 }
588
589 static boolean_t
590 zio_wait_for_children(zio_t *zio, uint8_t childbits, enum zio_wait_type wait)
591 {
592 boolean_t waiting = B_FALSE;
593
594 mutex_enter(&zio->io_lock);
595 ASSERT(zio->io_stall == NULL);
596 for (int c = 0; c < ZIO_CHILD_TYPES; c++) {
597 if (!(ZIO_CHILD_BIT_IS_SET(childbits, c)))
598 continue;
599
600 uint64_t *countp = &zio->io_children[c][wait];
601 if (*countp != 0) {
602 zio->io_stage >>= 1;
603 ASSERT3U(zio->io_stage, !=, ZIO_STAGE_OPEN);
604 zio->io_stall = countp;
605 waiting = B_TRUE;
606 break;
607 }
608 }
609 mutex_exit(&zio->io_lock);
610 return (waiting);
611 }
612
613 static void
614 zio_notify_parent(zio_t *pio, zio_t *zio, enum zio_wait_type wait)
615 {
616 uint64_t *countp = &pio->io_children[zio->io_child_type][wait];
617 int *errorp = &pio->io_child_error[zio->io_child_type];
618
619 mutex_enter(&pio->io_lock);
620 if (zio->io_error && !(zio->io_flags & ZIO_FLAG_DONT_PROPAGATE))
621 *errorp = zio_worst_error(*errorp, zio->io_error);
622 pio->io_reexecute |= zio->io_reexecute;
623 ASSERT3U(*countp, >, 0);
624
625 (*countp)--;
626
627 if (*countp == 0 && pio->io_stall == countp) {
628 zio_taskq_type_t type =
629 pio->io_stage < ZIO_STAGE_VDEV_IO_START ? ZIO_TASKQ_ISSUE :
630 ZIO_TASKQ_INTERRUPT;
631 pio->io_stall = NULL;
632 mutex_exit(&pio->io_lock);
633 /*
634 * Dispatch the parent zio in its own taskq so that
635 * the child can continue to make progress. This also
636 * prevents overflowing the stack when we have deeply nested
637 * parent-child relationships.
638 */
639 zio_taskq_dispatch(pio, type, B_FALSE);
640 } else {
641 mutex_exit(&pio->io_lock);
642 }
643 }
644
645 static void
646 zio_inherit_child_errors(zio_t *zio, enum zio_child c)
647 {
648 if (zio->io_child_error[c] != 0 && zio->io_error == 0)
649 zio->io_error = zio->io_child_error[c];
650 }
651
652 int
653 zio_bookmark_compare(const void *x1, const void *x2)
654 {
655 const zio_t *z1 = x1;
656 const zio_t *z2 = x2;
657
658 if (z1->io_bookmark.zb_objset < z2->io_bookmark.zb_objset)
659 return (-1);
660 if (z1->io_bookmark.zb_objset > z2->io_bookmark.zb_objset)
661 return (1);
662
663 if (z1->io_bookmark.zb_object < z2->io_bookmark.zb_object)
664 return (-1);
665 if (z1->io_bookmark.zb_object > z2->io_bookmark.zb_object)
666 return (1);
667
668 if (z1->io_bookmark.zb_level < z2->io_bookmark.zb_level)
669 return (-1);
670 if (z1->io_bookmark.zb_level > z2->io_bookmark.zb_level)
671 return (1);
672
673 if (z1->io_bookmark.zb_blkid < z2->io_bookmark.zb_blkid)
674 return (-1);
675 if (z1->io_bookmark.zb_blkid > z2->io_bookmark.zb_blkid)
676 return (1);
677
678 if (z1 < z2)
679 return (-1);
680 if (z1 > z2)
681 return (1);
682
683 return (0);
684 }
685
686 /*
687 * ==========================================================================
688 * Create the various types of I/O (read, write, free, etc)
689 * ==========================================================================
690 */
691 static zio_t *
692 zio_create(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp,
693 abd_t *data, uint64_t lsize, uint64_t psize, zio_done_func_t *done,
694 void *private, zio_type_t type, zio_priority_t priority,
695 enum zio_flag flags, vdev_t *vd, uint64_t offset,
696 const zbookmark_phys_t *zb, enum zio_stage stage, enum zio_stage pipeline)
697 {
698 zio_t *zio;
699
700 IMPLY(type != ZIO_TYPE_TRIM, psize <= SPA_MAXBLOCKSIZE);
701 ASSERT(P2PHASE(psize, SPA_MINBLOCKSIZE) == 0);
702 ASSERT(P2PHASE(offset, SPA_MINBLOCKSIZE) == 0);
703
704 ASSERT(!vd || spa_config_held(spa, SCL_STATE_ALL, RW_READER));
705 ASSERT(!bp || !(flags & ZIO_FLAG_CONFIG_WRITER));
706 ASSERT(vd || stage == ZIO_STAGE_OPEN);
707
708 IMPLY(lsize != psize, (flags & ZIO_FLAG_RAW_COMPRESS) != 0);
709
710 zio = kmem_cache_alloc(zio_cache, KM_SLEEP);
711 bzero(zio, sizeof (zio_t));
712
713 mutex_init(&zio->io_lock, NULL, MUTEX_DEFAULT, NULL);
714 cv_init(&zio->io_cv, NULL, CV_DEFAULT, NULL);
715
716 list_create(&zio->io_parent_list, sizeof (zio_link_t),
717 offsetof(zio_link_t, zl_parent_node));
718 list_create(&zio->io_child_list, sizeof (zio_link_t),
719 offsetof(zio_link_t, zl_child_node));
720 metaslab_trace_init(&zio->io_alloc_list);
721
722 if (vd != NULL)
723 zio->io_child_type = ZIO_CHILD_VDEV;
724 else if (flags & ZIO_FLAG_GANG_CHILD)
725 zio->io_child_type = ZIO_CHILD_GANG;
726 else if (flags & ZIO_FLAG_DDT_CHILD)
727 zio->io_child_type = ZIO_CHILD_DDT;
728 else
729 zio->io_child_type = ZIO_CHILD_LOGICAL;
730
731 if (bp != NULL) {
732 zio->io_bp = (blkptr_t *)bp;
733 zio->io_bp_copy = *bp;
734 zio->io_bp_orig = *bp;
735 if (type != ZIO_TYPE_WRITE ||
736 zio->io_child_type == ZIO_CHILD_DDT)
737 zio->io_bp = &zio->io_bp_copy; /* so caller can free */
738 if (zio->io_child_type == ZIO_CHILD_LOGICAL)
739 zio->io_logical = zio;
740 if (zio->io_child_type > ZIO_CHILD_GANG && BP_IS_GANG(bp))
741 pipeline |= ZIO_GANG_STAGES;
742 }
743
744 zio->io_spa = spa;
745 zio->io_txg = txg;
746 zio->io_done = done;
747 zio->io_private = private;
748 zio->io_type = type;
749 zio->io_priority = priority;
750 zio->io_vd = vd;
751 zio->io_offset = offset;
752 zio->io_orig_abd = zio->io_abd = data;
753 zio->io_orig_size = zio->io_size = psize;
754 zio->io_lsize = lsize;
755 zio->io_orig_flags = zio->io_flags = flags;
756 zio->io_orig_stage = zio->io_stage = stage;
757 zio->io_orig_pipeline = zio->io_pipeline = pipeline;
758 zio->io_pipeline_trace = ZIO_STAGE_OPEN;
759
760 zio->io_state[ZIO_WAIT_READY] = (stage >= ZIO_STAGE_READY);
761 zio->io_state[ZIO_WAIT_DONE] = (stage >= ZIO_STAGE_DONE);
762
763 if (zb != NULL)
764 zio->io_bookmark = *zb;
765
766 if (pio != NULL) {
767 if (zio->io_metaslab_class == NULL)
768 zio->io_metaslab_class = pio->io_metaslab_class;
769 if (zio->io_logical == NULL)
770 zio->io_logical = pio->io_logical;
771 if (zio->io_child_type == ZIO_CHILD_GANG)
772 zio->io_gang_leader = pio->io_gang_leader;
773 zio_add_child(pio, zio);
774 }
775
776 return (zio);
777 }
778
779 static void
780 zio_destroy(zio_t *zio)
781 {
782 metaslab_trace_fini(&zio->io_alloc_list);
783 list_destroy(&zio->io_parent_list);
784 list_destroy(&zio->io_child_list);
785 mutex_destroy(&zio->io_lock);
786 cv_destroy(&zio->io_cv);
787 kmem_cache_free(zio_cache, zio);
788 }
789
790 zio_t *
791 zio_null(zio_t *pio, spa_t *spa, vdev_t *vd, zio_done_func_t *done,
792 void *private, enum zio_flag flags)
793 {
794 zio_t *zio;
795
796 zio = zio_create(pio, spa, 0, NULL, NULL, 0, 0, done, private,
797 ZIO_TYPE_NULL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL,
798 ZIO_STAGE_OPEN, ZIO_INTERLOCK_PIPELINE);
799
800 return (zio);
801 }
802
803 zio_t *
804 zio_root(spa_t *spa, zio_done_func_t *done, void *private, enum zio_flag flags)
805 {
806 return (zio_null(NULL, spa, NULL, done, private, flags));
807 }
808
809 void
810 zfs_blkptr_verify(spa_t *spa, const blkptr_t *bp)
811 {
812 if (!DMU_OT_IS_VALID(BP_GET_TYPE(bp))) {
813 zfs_panic_recover("blkptr at %p has invalid TYPE %llu",
814 bp, (longlong_t)BP_GET_TYPE(bp));
815 }
816 if (BP_GET_CHECKSUM(bp) >= ZIO_CHECKSUM_FUNCTIONS ||
817 BP_GET_CHECKSUM(bp) <= ZIO_CHECKSUM_ON) {
818 zfs_panic_recover("blkptr at %p has invalid CHECKSUM %llu",
819 bp, (longlong_t)BP_GET_CHECKSUM(bp));
820 }
821 if (BP_GET_COMPRESS(bp) >= ZIO_COMPRESS_FUNCTIONS ||
822 BP_GET_COMPRESS(bp) <= ZIO_COMPRESS_ON) {
823 zfs_panic_recover("blkptr at %p has invalid COMPRESS %llu",
824 bp, (longlong_t)BP_GET_COMPRESS(bp));
825 }
826 if (BP_GET_LSIZE(bp) > SPA_MAXBLOCKSIZE) {
827 zfs_panic_recover("blkptr at %p has invalid LSIZE %llu",
828 bp, (longlong_t)BP_GET_LSIZE(bp));
829 }
830 if (BP_GET_PSIZE(bp) > SPA_MAXBLOCKSIZE) {
831 zfs_panic_recover("blkptr at %p has invalid PSIZE %llu",
832 bp, (longlong_t)BP_GET_PSIZE(bp));
833 }
834
835 if (BP_IS_EMBEDDED(bp)) {
836 if (BPE_GET_ETYPE(bp) > NUM_BP_EMBEDDED_TYPES) {
837 zfs_panic_recover("blkptr at %p has invalid ETYPE %llu",
838 bp, (longlong_t)BPE_GET_ETYPE(bp));
839 }
840 }
841
842 /*
843 * Do not verify individual DVAs if the config is not trusted. This
844 * will be done once the zio is executed in vdev_mirror_map_alloc.
845 */
846 if (!spa->spa_trust_config)
847 return;
848
849 /*
850 * Pool-specific checks.
851 *
852 * Note: it would be nice to verify that the blk_birth and
853 * BP_PHYSICAL_BIRTH() are not too large. However, spa_freeze()
854 * allows the birth time of log blocks (and dmu_sync()-ed blocks
855 * that are in the log) to be arbitrarily large.
856 */
857 for (int i = 0; i < BP_GET_NDVAS(bp); i++) {
858 uint64_t vdevid = DVA_GET_VDEV(&bp->blk_dva[i]);
859 if (vdevid >= spa->spa_root_vdev->vdev_children) {
860 zfs_panic_recover("blkptr at %p DVA %u has invalid "
861 "VDEV %llu",
862 bp, i, (longlong_t)vdevid);
863 continue;
864 }
865 vdev_t *vd = spa->spa_root_vdev->vdev_child[vdevid];
866 if (vd == NULL) {
867 zfs_panic_recover("blkptr at %p DVA %u has invalid "
868 "VDEV %llu",
869 bp, i, (longlong_t)vdevid);
870 continue;
871 }
872 if (vd->vdev_ops == &vdev_hole_ops) {
873 zfs_panic_recover("blkptr at %p DVA %u has hole "
874 "VDEV %llu",
875 bp, i, (longlong_t)vdevid);
876 continue;
877 }
878 if (vd->vdev_ops == &vdev_missing_ops) {
879 /*
880 * "missing" vdevs are valid during import, but we
881 * don't have their detailed info (e.g. asize), so
882 * we can't perform any more checks on them.
883 */
884 continue;
885 }
886 uint64_t offset = DVA_GET_OFFSET(&bp->blk_dva[i]);
887 uint64_t asize = DVA_GET_ASIZE(&bp->blk_dva[i]);
888 if (BP_IS_GANG(bp))
889 asize = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE);
890 if (offset + asize > vd->vdev_asize) {
891 zfs_panic_recover("blkptr at %p DVA %u has invalid "
892 "OFFSET %llu",
893 bp, i, (longlong_t)offset);
894 }
895 }
896 }
897
898 boolean_t
899 zfs_dva_valid(spa_t *spa, const dva_t *dva, const blkptr_t *bp)
900 {
901 uint64_t vdevid = DVA_GET_VDEV(dva);
902
903 if (vdevid >= spa->spa_root_vdev->vdev_children)
904 return (B_FALSE);
905
906 vdev_t *vd = spa->spa_root_vdev->vdev_child[vdevid];
907 if (vd == NULL)
908 return (B_FALSE);
909
910 if (vd->vdev_ops == &vdev_hole_ops)
911 return (B_FALSE);
912
913 if (vd->vdev_ops == &vdev_missing_ops) {
914 return (B_FALSE);
915 }
916
917 uint64_t offset = DVA_GET_OFFSET(dva);
918 uint64_t asize = DVA_GET_ASIZE(dva);
919
920 if (BP_IS_GANG(bp))
921 asize = vdev_psize_to_asize(vd, SPA_GANGBLOCKSIZE);
922 if (offset + asize > vd->vdev_asize)
923 return (B_FALSE);
924
925 return (B_TRUE);
926 }
927
928 zio_t *
929 zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp,
930 abd_t *data, uint64_t size, zio_done_func_t *done, void *private,
931 zio_priority_t priority, enum zio_flag flags, const zbookmark_phys_t *zb)
932 {
933 zio_t *zio;
934
935 zfs_blkptr_verify(spa, bp);
936
937 zio = zio_create(pio, spa, BP_PHYSICAL_BIRTH(bp), bp,
938 data, size, size, done, private,
939 ZIO_TYPE_READ, priority, flags, NULL, 0, zb,
940 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ?
941 ZIO_DDT_CHILD_READ_PIPELINE : ZIO_READ_PIPELINE);
942
943 return (zio);
944 }
945
946 zio_t *
947 zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
948 abd_t *data, uint64_t lsize, uint64_t psize, const zio_prop_t *zp,
949 zio_done_func_t *ready, zio_done_func_t *children_ready,
950 zio_done_func_t *physdone, zio_done_func_t *done,
951 void *private, zio_priority_t priority, enum zio_flag flags,
952 const zbookmark_phys_t *zb)
953 {
954 zio_t *zio;
955
956 ASSERT(zp->zp_checksum >= ZIO_CHECKSUM_OFF &&
957 zp->zp_checksum < ZIO_CHECKSUM_FUNCTIONS &&
958 zp->zp_compress >= ZIO_COMPRESS_OFF &&
959 zp->zp_compress < ZIO_COMPRESS_FUNCTIONS &&
960 DMU_OT_IS_VALID(zp->zp_type) &&
961 zp->zp_level < 32 &&
962 zp->zp_copies > 0 &&
963 zp->zp_copies <= spa_max_replication(spa));
964
965 zio = zio_create(pio, spa, txg, bp, data, lsize, psize, done, private,
966 ZIO_TYPE_WRITE, priority, flags, NULL, 0, zb,
967 ZIO_STAGE_OPEN, (flags & ZIO_FLAG_DDT_CHILD) ?
968 ZIO_DDT_CHILD_WRITE_PIPELINE : ZIO_WRITE_PIPELINE);
969
970 zio->io_ready = ready;
971 zio->io_children_ready = children_ready;
972 zio->io_physdone = physdone;
973 zio->io_prop = *zp;
974
975 /*
976 * Data can be NULL if we are going to call zio_write_override() to
977 * provide the already-allocated BP. But we may need the data to
978 * verify a dedup hit (if requested). In this case, don't try to
979 * dedup (just take the already-allocated BP verbatim). Encrypted
980 * dedup blocks need data as well so we also disable dedup in this
981 * case.
982 */
983 if (data == NULL &&
984 (zio->io_prop.zp_dedup_verify || zio->io_prop.zp_encrypt)) {
985 zio->io_prop.zp_dedup = zio->io_prop.zp_dedup_verify = B_FALSE;
986 }
987
988 return (zio);
989 }
990
991 zio_t *
992 zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp, abd_t *data,
993 uint64_t size, zio_done_func_t *done, void *private,
994 zio_priority_t priority, enum zio_flag flags, zbookmark_phys_t *zb)
995 {
996 zio_t *zio;
997
998 zio = zio_create(pio, spa, txg, bp, data, size, size, done, private,
999 ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_IO_REWRITE, NULL, 0, zb,
1000 ZIO_STAGE_OPEN, ZIO_REWRITE_PIPELINE);
1001
1002 return (zio);
1003 }
1004
1005 void
1006 zio_write_override(zio_t *zio, blkptr_t *bp, int copies, boolean_t nopwrite)
1007 {
1008 ASSERT(zio->io_type == ZIO_TYPE_WRITE);
1009 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1010 ASSERT(zio->io_stage == ZIO_STAGE_OPEN);
1011 ASSERT(zio->io_txg == spa_syncing_txg(zio->io_spa));
1012
1013 /*
1014 * We must reset the io_prop to match the values that existed
1015 * when the bp was first written by dmu_sync() keeping in mind
1016 * that nopwrite and dedup are mutually exclusive.
1017 */
1018 zio->io_prop.zp_dedup = nopwrite ? B_FALSE : zio->io_prop.zp_dedup;
1019 zio->io_prop.zp_nopwrite = nopwrite;
1020 zio->io_prop.zp_copies = copies;
1021 zio->io_bp_override = bp;
1022 }
1023
1024 void
1025 zio_free(spa_t *spa, uint64_t txg, const blkptr_t *bp)
1026 {
1027
1028 zfs_blkptr_verify(spa, bp);
1029
1030 /*
1031 * The check for EMBEDDED is a performance optimization. We
1032 * process the free here (by ignoring it) rather than
1033 * putting it on the list and then processing it in zio_free_sync().
1034 */
1035 if (BP_IS_EMBEDDED(bp))
1036 return;
1037 metaslab_check_free(spa, bp);
1038
1039 /*
1040 * Frees that are for the currently-syncing txg, are not going to be
1041 * deferred, and which will not need to do a read (i.e. not GANG or
1042 * DEDUP), can be processed immediately. Otherwise, put them on the
1043 * in-memory list for later processing.
1044 *
1045 * Note that we only defer frees after zfs_sync_pass_deferred_free
1046 * when the log space map feature is disabled. [see relevant comment
1047 * in spa_sync_iterate_to_convergence()]
1048 */
1049 if (BP_IS_GANG(bp) ||
1050 BP_GET_DEDUP(bp) ||
1051 txg != spa->spa_syncing_txg ||
1052 (spa_sync_pass(spa) >= zfs_sync_pass_deferred_free &&
1053 !spa_feature_is_active(spa, SPA_FEATURE_LOG_SPACEMAP))) {
1054 bplist_append(&spa->spa_free_bplist[txg & TXG_MASK], bp);
1055 } else {
1056 VERIFY0(zio_wait(zio_free_sync(NULL, spa, txg, bp, 0)));
1057 }
1058 }
1059
1060 zio_t *
1061 zio_free_sync(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp,
1062 enum zio_flag flags)
1063 {
1064 zio_t *zio;
1065 enum zio_stage stage = ZIO_FREE_PIPELINE;
1066
1067 ASSERT(!BP_IS_HOLE(bp));
1068 ASSERT(spa_syncing_txg(spa) == txg);
1069
1070 if (BP_IS_EMBEDDED(bp))
1071 return (zio_null(pio, spa, NULL, NULL, NULL, 0));
1072
1073 metaslab_check_free(spa, bp);
1074 arc_freed(spa, bp);
1075 dsl_scan_freed(spa, bp);
1076
1077 /*
1078 * GANG and DEDUP blocks can induce a read (for the gang block header,
1079 * or the DDT), so issue them asynchronously so that this thread is
1080 * not tied up.
1081 */
1082 if (BP_IS_GANG(bp) || BP_GET_DEDUP(bp))
1083 stage |= ZIO_STAGE_ISSUE_ASYNC;
1084
1085 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp),
1086 BP_GET_PSIZE(bp), NULL, NULL, ZIO_TYPE_FREE, ZIO_PRIORITY_NOW,
1087 flags, NULL, 0, NULL, ZIO_STAGE_OPEN, stage);
1088
1089 return (zio);
1090 }
1091
1092 zio_t *
1093 zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, const blkptr_t *bp,
1094 zio_done_func_t *done, void *private, enum zio_flag flags)
1095 {
1096 zio_t *zio;
1097
1098 zfs_blkptr_verify(spa, bp);
1099
1100 if (BP_IS_EMBEDDED(bp))
1101 return (zio_null(pio, spa, NULL, NULL, NULL, 0));
1102
1103 /*
1104 * A claim is an allocation of a specific block. Claims are needed
1105 * to support immediate writes in the intent log. The issue is that
1106 * immediate writes contain committed data, but in a txg that was
1107 * *not* committed. Upon opening the pool after an unclean shutdown,
1108 * the intent log claims all blocks that contain immediate write data
1109 * so that the SPA knows they're in use.
1110 *
1111 * All claims *must* be resolved in the first txg -- before the SPA
1112 * starts allocating blocks -- so that nothing is allocated twice.
1113 * If txg == 0 we just verify that the block is claimable.
1114 */
1115 ASSERT3U(spa->spa_uberblock.ub_rootbp.blk_birth, <,
1116 spa_min_claim_txg(spa));
1117 ASSERT(txg == spa_min_claim_txg(spa) || txg == 0);
1118 ASSERT(!BP_GET_DEDUP(bp) || !spa_writeable(spa)); /* zdb(1M) */
1119
1120 zio = zio_create(pio, spa, txg, bp, NULL, BP_GET_PSIZE(bp),
1121 BP_GET_PSIZE(bp), done, private, ZIO_TYPE_CLAIM, ZIO_PRIORITY_NOW,
1122 flags, NULL, 0, NULL, ZIO_STAGE_OPEN, ZIO_CLAIM_PIPELINE);
1123 ASSERT0(zio->io_queued_timestamp);
1124
1125 return (zio);
1126 }
1127
1128 zio_t *
1129 zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
1130 zio_done_func_t *done, void *private, enum zio_flag flags)
1131 {
1132 zio_t *zio;
1133 int c;
1134
1135 if (vd->vdev_children == 0) {
1136 zio = zio_create(pio, spa, 0, NULL, NULL, 0, 0, done, private,
1137 ZIO_TYPE_IOCTL, ZIO_PRIORITY_NOW, flags, vd, 0, NULL,
1138 ZIO_STAGE_OPEN, ZIO_IOCTL_PIPELINE);
1139
1140 zio->io_cmd = cmd;
1141 } else {
1142 zio = zio_null(pio, spa, NULL, NULL, NULL, flags);
1143
1144 for (c = 0; c < vd->vdev_children; c++)
1145 zio_nowait(zio_ioctl(zio, spa, vd->vdev_child[c], cmd,
1146 done, private, flags));
1147 }
1148
1149 return (zio);
1150 }
1151
1152 zio_t *
1153 zio_trim(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size,
1154 zio_done_func_t *done, void *private, zio_priority_t priority,
1155 enum zio_flag flags, enum trim_flag trim_flags)
1156 {
1157 zio_t *zio;
1158
1159 ASSERT0(vd->vdev_children);
1160 ASSERT0(P2PHASE(offset, 1ULL << vd->vdev_ashift));
1161 ASSERT0(P2PHASE(size, 1ULL << vd->vdev_ashift));
1162 ASSERT3U(size, !=, 0);
1163
1164 zio = zio_create(pio, vd->vdev_spa, 0, NULL, NULL, size, size, done,
1165 private, ZIO_TYPE_TRIM, priority, flags | ZIO_FLAG_PHYSICAL,
1166 vd, offset, NULL, ZIO_STAGE_OPEN, ZIO_TRIM_PIPELINE);
1167 zio->io_trim_flags = trim_flags;
1168
1169 return (zio);
1170 }
1171
1172 zio_t *
1173 zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size,
1174 abd_t *data, int checksum, zio_done_func_t *done, void *private,
1175 zio_priority_t priority, enum zio_flag flags, boolean_t labels)
1176 {
1177 zio_t *zio;
1178
1179 ASSERT(vd->vdev_children == 0);
1180 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE ||
1181 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE);
1182 ASSERT3U(offset + size, <=, vd->vdev_psize);
1183
1184 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, size, done,
1185 private, ZIO_TYPE_READ, priority, flags | ZIO_FLAG_PHYSICAL, vd,
1186 offset, NULL, ZIO_STAGE_OPEN, ZIO_READ_PHYS_PIPELINE);
1187
1188 zio->io_prop.zp_checksum = checksum;
1189
1190 return (zio);
1191 }
1192
1193 zio_t *
1194 zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset, uint64_t size,
1195 abd_t *data, int checksum, zio_done_func_t *done, void *private,
1196 zio_priority_t priority, enum zio_flag flags, boolean_t labels)
1197 {
1198 zio_t *zio;
1199
1200 ASSERT(vd->vdev_children == 0);
1201 ASSERT(!labels || offset + size <= VDEV_LABEL_START_SIZE ||
1202 offset >= vd->vdev_psize - VDEV_LABEL_END_SIZE);
1203 ASSERT3U(offset + size, <=, vd->vdev_psize);
1204
1205 zio = zio_create(pio, vd->vdev_spa, 0, NULL, data, size, size, done,
1206 private, ZIO_TYPE_WRITE, priority, flags | ZIO_FLAG_PHYSICAL, vd,
1207 offset, NULL, ZIO_STAGE_OPEN, ZIO_WRITE_PHYS_PIPELINE);
1208
1209 zio->io_prop.zp_checksum = checksum;
1210
1211 if (zio_checksum_table[checksum].ci_flags & ZCHECKSUM_FLAG_EMBEDDED) {
1212 /*
1213 * zec checksums are necessarily destructive -- they modify
1214 * the end of the write buffer to hold the verifier/checksum.
1215 * Therefore, we must make a local copy in case the data is
1216 * being written to multiple places in parallel.
1217 */
1218 abd_t *wbuf = abd_alloc_sametype(data, size);
1219 abd_copy(wbuf, data, size);
1220
1221 zio_push_transform(zio, wbuf, size, size, NULL);
1222 }
1223
1224 return (zio);
1225 }
1226
1227 /*
1228 * Create a child I/O to do some work for us.
1229 */
1230 zio_t *
1231 zio_vdev_child_io(zio_t *pio, blkptr_t *bp, vdev_t *vd, uint64_t offset,
1232 abd_t *data, uint64_t size, int type, zio_priority_t priority,
1233 enum zio_flag flags, zio_done_func_t *done, void *private)
1234 {
1235 enum zio_stage pipeline = ZIO_VDEV_CHILD_PIPELINE;
1236 zio_t *zio;
1237
1238 /*
1239 * vdev child I/Os do not propagate their error to the parent.
1240 * Therefore, for correct operation the caller *must* check for
1241 * and handle the error in the child i/o's done callback.
1242 * The only exceptions are i/os that we don't care about
1243 * (OPTIONAL or REPAIR).
1244 */
1245 ASSERT((flags & ZIO_FLAG_OPTIONAL) || (flags & ZIO_FLAG_IO_REPAIR) ||
1246 done != NULL);
1247
1248 if (type == ZIO_TYPE_READ && bp != NULL) {
1249 /*
1250 * If we have the bp, then the child should perform the
1251 * checksum and the parent need not. This pushes error
1252 * detection as close to the leaves as possible and
1253 * eliminates redundant checksums in the interior nodes.
1254 */
1255 pipeline |= ZIO_STAGE_CHECKSUM_VERIFY;
1256 pio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY;
1257 }
1258
1259 if (vd->vdev_ops->vdev_op_leaf) {
1260 ASSERT0(vd->vdev_children);
1261 offset += VDEV_LABEL_START_SIZE;
1262 }
1263
1264 flags |= ZIO_VDEV_CHILD_FLAGS(pio);
1265
1266 /*
1267 * If we've decided to do a repair, the write is not speculative --
1268 * even if the original read was.
1269 */
1270 if (flags & ZIO_FLAG_IO_REPAIR)
1271 flags &= ~ZIO_FLAG_SPECULATIVE;
1272
1273 /*
1274 * If we're creating a child I/O that is not associated with a
1275 * top-level vdev, then the child zio is not an allocating I/O.
1276 * If this is a retried I/O then we ignore it since we will
1277 * have already processed the original allocating I/O.
1278 */
1279 if (flags & ZIO_FLAG_IO_ALLOCATING &&
1280 (vd != vd->vdev_top || (flags & ZIO_FLAG_IO_RETRY))) {
1281 ASSERT(pio->io_metaslab_class != NULL);
1282 ASSERT(pio->io_metaslab_class->mc_alloc_throttle_enabled);
1283 ASSERT(type == ZIO_TYPE_WRITE);
1284 ASSERT(priority == ZIO_PRIORITY_ASYNC_WRITE);
1285 ASSERT(!(flags & ZIO_FLAG_IO_REPAIR));
1286 ASSERT(!(pio->io_flags & ZIO_FLAG_IO_REWRITE) ||
1287 pio->io_child_type == ZIO_CHILD_GANG);
1288
1289 flags &= ~ZIO_FLAG_IO_ALLOCATING;
1290 }
1291
1292 zio = zio_create(pio, pio->io_spa, pio->io_txg, bp, data, size, size,
1293 done, private, type, priority, flags, vd, offset, &pio->io_bookmark,
1294 ZIO_STAGE_VDEV_IO_START >> 1, pipeline);
1295 ASSERT3U(zio->io_child_type, ==, ZIO_CHILD_VDEV);
1296
1297 zio->io_physdone = pio->io_physdone;
1298 if (vd->vdev_ops->vdev_op_leaf && zio->io_logical != NULL)
1299 zio->io_logical->io_phys_children++;
1300
1301 return (zio);
1302 }
1303
1304 zio_t *
1305 zio_vdev_delegated_io(vdev_t *vd, uint64_t offset, abd_t *data, uint64_t size,
1306 zio_type_t type, zio_priority_t priority, enum zio_flag flags,
1307 zio_done_func_t *done, void *private)
1308 {
1309 zio_t *zio;
1310
1311 ASSERT(vd->vdev_ops->vdev_op_leaf);
1312
1313 zio = zio_create(NULL, vd->vdev_spa, 0, NULL,
1314 data, size, size, done, private, type, priority,
1315 flags | ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_RETRY | ZIO_FLAG_DELEGATED,
1316 vd, offset, NULL,
1317 ZIO_STAGE_VDEV_IO_START >> 1, ZIO_VDEV_CHILD_PIPELINE);
1318
1319 return (zio);
1320 }
1321
1322 void
1323 zio_flush(zio_t *zio, vdev_t *vd)
1324 {
1325 zio_nowait(zio_ioctl(zio, zio->io_spa, vd, DKIOCFLUSHWRITECACHE,
1326 NULL, NULL,
1327 ZIO_FLAG_CANFAIL | ZIO_FLAG_DONT_PROPAGATE | ZIO_FLAG_DONT_RETRY));
1328 }
1329
1330 void
1331 zio_shrink(zio_t *zio, uint64_t size)
1332 {
1333 ASSERT3P(zio->io_executor, ==, NULL);
1334 ASSERT3P(zio->io_orig_size, ==, zio->io_size);
1335 ASSERT3U(size, <=, zio->io_size);
1336
1337 /*
1338 * We don't shrink for raidz because of problems with the
1339 * reconstruction when reading back less than the block size.
1340 * Note, BP_IS_RAIDZ() assumes no compression.
1341 */
1342 ASSERT(BP_GET_COMPRESS(zio->io_bp) == ZIO_COMPRESS_OFF);
1343 if (!BP_IS_RAIDZ(zio->io_bp)) {
1344 /* we are not doing a raw write */
1345 ASSERT3U(zio->io_size, ==, zio->io_lsize);
1346 zio->io_orig_size = zio->io_size = zio->io_lsize = size;
1347 }
1348 }
1349
1350 /*
1351 * ==========================================================================
1352 * Prepare to read and write logical blocks
1353 * ==========================================================================
1354 */
1355
1356 static int
1357 zio_read_bp_init(zio_t *zio)
1358 {
1359 blkptr_t *bp = zio->io_bp;
1360 uint64_t psize =
1361 BP_IS_EMBEDDED(bp) ? BPE_GET_PSIZE(bp) : BP_GET_PSIZE(bp);
1362
1363 ASSERT3P(zio->io_bp, ==, &zio->io_bp_copy);
1364
1365 if (BP_GET_COMPRESS(bp) != ZIO_COMPRESS_OFF &&
1366 zio->io_child_type == ZIO_CHILD_LOGICAL &&
1367 !(zio->io_flags & ZIO_FLAG_RAW_COMPRESS)) {
1368 zio_push_transform(zio, abd_alloc_sametype(zio->io_abd, psize),
1369 psize, psize, zio_decompress);
1370 }
1371
1372 if (((BP_IS_PROTECTED(bp) && !(zio->io_flags & ZIO_FLAG_RAW_ENCRYPT)) ||
1373 BP_HAS_INDIRECT_MAC_CKSUM(bp)) &&
1374 zio->io_child_type == ZIO_CHILD_LOGICAL) {
1375 zio_push_transform(zio, abd_alloc_sametype(zio->io_abd, psize),
1376 psize, psize, zio_decrypt);
1377 }
1378
1379 if (BP_IS_EMBEDDED(bp) && BPE_GET_ETYPE(bp) == BP_EMBEDDED_TYPE_DATA) {
1380 int psize = BPE_GET_PSIZE(bp);
1381 void *data = abd_borrow_buf(zio->io_abd, psize);
1382
1383 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
1384 decode_embedded_bp_compressed(bp, data);
1385 abd_return_buf_copy(zio->io_abd, data, psize);
1386 } else {
1387 ASSERT(!BP_IS_EMBEDDED(bp));
1388 ASSERT3P(zio->io_bp, ==, &zio->io_bp_copy);
1389 }
1390
1391 if (!DMU_OT_IS_METADATA(BP_GET_TYPE(bp)) && BP_GET_LEVEL(bp) == 0)
1392 zio->io_flags |= ZIO_FLAG_DONT_CACHE;
1393
1394 if (BP_GET_TYPE(bp) == DMU_OT_DDT_ZAP)
1395 zio->io_flags |= ZIO_FLAG_DONT_CACHE;
1396
1397 if (BP_GET_DEDUP(bp) && zio->io_child_type == ZIO_CHILD_LOGICAL)
1398 zio->io_pipeline = ZIO_DDT_READ_PIPELINE;
1399
1400 return (ZIO_PIPELINE_CONTINUE);
1401 }
1402
1403 static int
1404 zio_write_bp_init(zio_t *zio)
1405 {
1406 if (!IO_IS_ALLOCATING(zio))
1407 return (ZIO_PIPELINE_CONTINUE);
1408
1409 ASSERT(zio->io_child_type != ZIO_CHILD_DDT);
1410
1411 if (zio->io_bp_override) {
1412 blkptr_t *bp = zio->io_bp;
1413 zio_prop_t *zp = &zio->io_prop;
1414
1415 ASSERT(bp->blk_birth != zio->io_txg);
1416 ASSERT(BP_GET_DEDUP(zio->io_bp_override) == 0);
1417
1418 *bp = *zio->io_bp_override;
1419 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
1420
1421 if (BP_IS_EMBEDDED(bp))
1422 return (ZIO_PIPELINE_CONTINUE);
1423
1424 /*
1425 * If we've been overridden and nopwrite is set then
1426 * set the flag accordingly to indicate that a nopwrite
1427 * has already occurred.
1428 */
1429 if (!BP_IS_HOLE(bp) && zp->zp_nopwrite) {
1430 ASSERT(!zp->zp_dedup);
1431 ASSERT3U(BP_GET_CHECKSUM(bp), ==, zp->zp_checksum);
1432 zio->io_flags |= ZIO_FLAG_NOPWRITE;
1433 return (ZIO_PIPELINE_CONTINUE);
1434 }
1435
1436 ASSERT(!zp->zp_nopwrite);
1437
1438 if (BP_IS_HOLE(bp) || !zp->zp_dedup)
1439 return (ZIO_PIPELINE_CONTINUE);
1440
1441 ASSERT((zio_checksum_table[zp->zp_checksum].ci_flags &
1442 ZCHECKSUM_FLAG_DEDUP) || zp->zp_dedup_verify);
1443
1444 if (BP_GET_CHECKSUM(bp) == zp->zp_checksum &&
1445 !zp->zp_encrypt) {
1446 BP_SET_DEDUP(bp, 1);
1447 zio->io_pipeline |= ZIO_STAGE_DDT_WRITE;
1448 return (ZIO_PIPELINE_CONTINUE);
1449 }
1450
1451 /*
1452 * We were unable to handle this as an override bp, treat
1453 * it as a regular write I/O.
1454 */
1455 zio->io_bp_override = NULL;
1456 *bp = zio->io_bp_orig;
1457 zio->io_pipeline = zio->io_orig_pipeline;
1458 }
1459
1460 return (ZIO_PIPELINE_CONTINUE);
1461 }
1462
1463 static int
1464 zio_write_compress(zio_t *zio)
1465 {
1466 spa_t *spa = zio->io_spa;
1467 zio_prop_t *zp = &zio->io_prop;
1468 enum zio_compress compress = zp->zp_compress;
1469 blkptr_t *bp = zio->io_bp;
1470 uint64_t lsize = zio->io_lsize;
1471 uint64_t psize = zio->io_size;
1472 int pass = 1;
1473
1474 /*
1475 * If our children haven't all reached the ready stage,
1476 * wait for them and then repeat this pipeline stage.
1477 */
1478 if (zio_wait_for_children(zio, ZIO_CHILD_LOGICAL_BIT |
1479 ZIO_CHILD_GANG_BIT, ZIO_WAIT_READY)) {
1480 return (ZIO_PIPELINE_STOP);
1481 }
1482
1483 if (!IO_IS_ALLOCATING(zio))
1484 return (ZIO_PIPELINE_CONTINUE);
1485
1486 if (zio->io_children_ready != NULL) {
1487 /*
1488 * Now that all our children are ready, run the callback
1489 * associated with this zio in case it wants to modify the
1490 * data to be written.
1491 */
1492 ASSERT3U(zp->zp_level, >, 0);
1493 zio->io_children_ready(zio);
1494 }
1495
1496 ASSERT(zio->io_child_type != ZIO_CHILD_DDT);
1497 ASSERT(zio->io_bp_override == NULL);
1498
1499 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg) {
1500 /*
1501 * We're rewriting an existing block, which means we're
1502 * working on behalf of spa_sync(). For spa_sync() to
1503 * converge, it must eventually be the case that we don't
1504 * have to allocate new blocks. But compression changes
1505 * the blocksize, which forces a reallocate, and makes
1506 * convergence take longer. Therefore, after the first
1507 * few passes, stop compressing to ensure convergence.
1508 */
1509 pass = spa_sync_pass(spa);
1510
1511 ASSERT(zio->io_txg == spa_syncing_txg(spa));
1512 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1513 ASSERT(!BP_GET_DEDUP(bp));
1514
1515 if (pass >= zfs_sync_pass_dont_compress)
1516 compress = ZIO_COMPRESS_OFF;
1517
1518 /* Make sure someone doesn't change their mind on overwrites */
1519 ASSERT(BP_IS_EMBEDDED(bp) || MIN(zp->zp_copies + BP_IS_GANG(bp),
1520 spa_max_replication(spa)) == BP_GET_NDVAS(bp));
1521 }
1522
1523 /* If it's a compressed write that is not raw, compress the buffer. */
1524 if (compress != ZIO_COMPRESS_OFF &&
1525 !(zio->io_flags & ZIO_FLAG_RAW_COMPRESS)) {
1526 void *cbuf = zio_buf_alloc(lsize);
1527 psize = zio_compress_data(compress, zio->io_abd, cbuf, lsize);
1528 if (psize == 0 || psize == lsize) {
1529 compress = ZIO_COMPRESS_OFF;
1530 zio_buf_free(cbuf, lsize);
1531 } else if (!zp->zp_dedup && !zp->zp_encrypt &&
1532 psize <= BPE_PAYLOAD_SIZE &&
1533 zp->zp_level == 0 && !DMU_OT_HAS_FILL(zp->zp_type) &&
1534 spa_feature_is_enabled(spa, SPA_FEATURE_EMBEDDED_DATA)) {
1535 encode_embedded_bp_compressed(bp,
1536 cbuf, compress, lsize, psize);
1537 BPE_SET_ETYPE(bp, BP_EMBEDDED_TYPE_DATA);
1538 BP_SET_TYPE(bp, zio->io_prop.zp_type);
1539 BP_SET_LEVEL(bp, zio->io_prop.zp_level);
1540 zio_buf_free(cbuf, lsize);
1541 bp->blk_birth = zio->io_txg;
1542 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
1543 ASSERT(spa_feature_is_active(spa,
1544 SPA_FEATURE_EMBEDDED_DATA));
1545 return (ZIO_PIPELINE_CONTINUE);
1546 } else {
1547 /*
1548 * Round up compressed size up to the ashift
1549 * of the smallest-ashift device, and zero the tail.
1550 * This ensures that the compressed size of the BP
1551 * (and thus compressratio property) are correct,
1552 * in that we charge for the padding used to fill out
1553 * the last sector.
1554 */
1555 ASSERT3U(spa->spa_min_ashift, >=, SPA_MINBLOCKSHIFT);
1556 size_t rounded = (size_t)P2ROUNDUP(psize,
1557 1ULL << spa->spa_min_ashift);
1558 if (rounded >= lsize) {
1559 compress = ZIO_COMPRESS_OFF;
1560 zio_buf_free(cbuf, lsize);
1561 psize = lsize;
1562 } else {
1563 abd_t *cdata = abd_get_from_buf(cbuf, lsize);
1564 abd_take_ownership_of_buf(cdata, B_TRUE);
1565 abd_zero_off(cdata, psize, rounded - psize);
1566 psize = rounded;
1567 zio_push_transform(zio, cdata,
1568 psize, lsize, NULL);
1569 }
1570 }
1571
1572 /*
1573 * We were unable to handle this as an override bp, treat
1574 * it as a regular write I/O.
1575 */
1576 zio->io_bp_override = NULL;
1577 *bp = zio->io_bp_orig;
1578 zio->io_pipeline = zio->io_orig_pipeline;
1579
1580 } else if ((zio->io_flags & ZIO_FLAG_RAW_ENCRYPT) != 0 &&
1581 zp->zp_type == DMU_OT_DNODE) {
1582 /*
1583 * The DMU actually relies on the zio layer's compression
1584 * to free metadnode blocks that have had all contained
1585 * dnodes freed. As a result, even when doing a raw
1586 * receive, we must check whether the block can be compressed
1587 * to a hole.
1588 */
1589 psize = zio_compress_data(ZIO_COMPRESS_EMPTY,
1590 zio->io_abd, NULL, lsize);
1591 if (psize == 0)
1592 compress = ZIO_COMPRESS_OFF;
1593 } else {
1594 ASSERT3U(psize, !=, 0);
1595 }
1596
1597 /*
1598 * The final pass of spa_sync() must be all rewrites, but the first
1599 * few passes offer a trade-off: allocating blocks defers convergence,
1600 * but newly allocated blocks are sequential, so they can be written
1601 * to disk faster. Therefore, we allow the first few passes of
1602 * spa_sync() to allocate new blocks, but force rewrites after that.
1603 * There should only be a handful of blocks after pass 1 in any case.
1604 */
1605 if (!BP_IS_HOLE(bp) && bp->blk_birth == zio->io_txg &&
1606 BP_GET_PSIZE(bp) == psize &&
1607 pass >= zfs_sync_pass_rewrite) {
1608 VERIFY3U(psize, !=, 0);
1609 enum zio_stage gang_stages = zio->io_pipeline & ZIO_GANG_STAGES;
1610 zio->io_pipeline = ZIO_REWRITE_PIPELINE | gang_stages;
1611 zio->io_flags |= ZIO_FLAG_IO_REWRITE;
1612 } else {
1613 BP_ZERO(bp);
1614 zio->io_pipeline = ZIO_WRITE_PIPELINE;
1615 }
1616
1617 if (psize == 0) {
1618 if (zio->io_bp_orig.blk_birth != 0 &&
1619 spa_feature_is_active(spa, SPA_FEATURE_HOLE_BIRTH)) {
1620 BP_SET_LSIZE(bp, lsize);
1621 BP_SET_TYPE(bp, zp->zp_type);
1622 BP_SET_LEVEL(bp, zp->zp_level);
1623 BP_SET_BIRTH(bp, zio->io_txg, 0);
1624 }
1625 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
1626 } else {
1627 ASSERT(zp->zp_checksum != ZIO_CHECKSUM_GANG_HEADER);
1628 BP_SET_LSIZE(bp, lsize);
1629 BP_SET_TYPE(bp, zp->zp_type);
1630 BP_SET_LEVEL(bp, zp->zp_level);
1631 BP_SET_PSIZE(bp, psize);
1632 BP_SET_COMPRESS(bp, compress);
1633 BP_SET_CHECKSUM(bp, zp->zp_checksum);
1634 BP_SET_DEDUP(bp, zp->zp_dedup);
1635 BP_SET_BYTEORDER(bp, ZFS_HOST_BYTEORDER);
1636 if (zp->zp_dedup) {
1637 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1638 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE));
1639 ASSERT(!zp->zp_encrypt ||
1640 DMU_OT_IS_ENCRYPTED(zp->zp_type));
1641 zio->io_pipeline = ZIO_DDT_WRITE_PIPELINE;
1642 }
1643 if (zp->zp_nopwrite) {
1644 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
1645 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE));
1646 zio->io_pipeline |= ZIO_STAGE_NOP_WRITE;
1647 }
1648 }
1649 return (ZIO_PIPELINE_CONTINUE);
1650 }
1651
1652 static int
1653 zio_free_bp_init(zio_t *zio)
1654 {
1655 blkptr_t *bp = zio->io_bp;
1656
1657 if (zio->io_child_type == ZIO_CHILD_LOGICAL) {
1658 if (BP_GET_DEDUP(bp))
1659 zio->io_pipeline = ZIO_DDT_FREE_PIPELINE;
1660 }
1661
1662 ASSERT3P(zio->io_bp, ==, &zio->io_bp_copy);
1663
1664 return (ZIO_PIPELINE_CONTINUE);
1665 }
1666
1667 /*
1668 * ==========================================================================
1669 * Execute the I/O pipeline
1670 * ==========================================================================
1671 */
1672
1673 static void
1674 zio_taskq_dispatch(zio_t *zio, zio_taskq_type_t q, boolean_t cutinline)
1675 {
1676 spa_t *spa = zio->io_spa;
1677 zio_type_t t = zio->io_type;
1678 int flags = (cutinline ? TQ_FRONT : 0);
1679
1680 /*
1681 * If we're a config writer or a probe, the normal issue and
1682 * interrupt threads may all be blocked waiting for the config lock.
1683 * In this case, select the otherwise-unused taskq for ZIO_TYPE_NULL.
1684 */
1685 if (zio->io_flags & (ZIO_FLAG_CONFIG_WRITER | ZIO_FLAG_PROBE))
1686 t = ZIO_TYPE_NULL;
1687
1688 /*
1689 * A similar issue exists for the L2ARC write thread until L2ARC 2.0.
1690 */
1691 if (t == ZIO_TYPE_WRITE && zio->io_vd && zio->io_vd->vdev_aux)
1692 t = ZIO_TYPE_NULL;
1693
1694 /*
1695 * If this is a high priority I/O, then use the high priority taskq if
1696 * available.
1697 */
1698 if ((zio->io_priority == ZIO_PRIORITY_NOW ||
1699 zio->io_priority == ZIO_PRIORITY_SYNC_WRITE) &&
1700 spa->spa_zio_taskq[t][q + 1].stqs_count != 0)
1701 q++;
1702
1703 ASSERT3U(q, <, ZIO_TASKQ_TYPES);
1704
1705 /*
1706 * NB: We are assuming that the zio can only be dispatched
1707 * to a single taskq at a time. It would be a grievous error
1708 * to dispatch the zio to another taskq at the same time.
1709 */
1710 ASSERT(zio->io_tqent.tqent_next == NULL);
1711 spa_taskq_dispatch_ent(spa, t, q, (task_func_t *)zio_execute, zio,
1712 flags, &zio->io_tqent);
1713 }
1714
1715 static boolean_t
1716 zio_taskq_member(zio_t *zio, zio_taskq_type_t q)
1717 {
1718 kthread_t *executor = zio->io_executor;
1719 spa_t *spa = zio->io_spa;
1720
1721 for (zio_type_t t = 0; t < ZIO_TYPES; t++) {
1722 spa_taskqs_t *tqs = &spa->spa_zio_taskq[t][q];
1723 uint_t i;
1724 for (i = 0; i < tqs->stqs_count; i++) {
1725 if (taskq_member(tqs->stqs_taskq[i], executor))
1726 return (B_TRUE);
1727 }
1728 }
1729
1730 return (B_FALSE);
1731 }
1732
1733 static int
1734 zio_issue_async(zio_t *zio)
1735 {
1736 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE);
1737
1738 return (ZIO_PIPELINE_STOP);
1739 }
1740
1741 void
1742 zio_interrupt(zio_t *zio)
1743 {
1744 zio_taskq_dispatch(zio, ZIO_TASKQ_INTERRUPT, B_FALSE);
1745 }
1746
1747 void
1748 zio_delay_interrupt(zio_t *zio)
1749 {
1750 /*
1751 * The timeout_generic() function isn't defined in userspace, so
1752 * rather than trying to implement the function, the zio delay
1753 * functionality has been disabled for userspace builds.
1754 */
1755
1756 #ifdef _KERNEL
1757 /*
1758 * If io_target_timestamp is zero, then no delay has been registered
1759 * for this IO, thus jump to the end of this function and "skip" the
1760 * delay; issuing it directly to the zio layer.
1761 */
1762 if (zio->io_target_timestamp != 0) {
1763 hrtime_t now = gethrtime();
1764
1765 if (now >= zio->io_target_timestamp) {
1766 /*
1767 * This IO has already taken longer than the target
1768 * delay to complete, so we don't want to delay it
1769 * any longer; we "miss" the delay and issue it
1770 * directly to the zio layer. This is likely due to
1771 * the target latency being set to a value less than
1772 * the underlying hardware can satisfy (e.g. delay
1773 * set to 1ms, but the disks take 10ms to complete an
1774 * IO request).
1775 */
1776
1777 DTRACE_PROBE2(zio__delay__miss, zio_t *, zio,
1778 hrtime_t, now);
1779
1780 zio_interrupt(zio);
1781 } else {
1782 hrtime_t diff = zio->io_target_timestamp - now;
1783
1784 DTRACE_PROBE3(zio__delay__hit, zio_t *, zio,
1785 hrtime_t, now, hrtime_t, diff);
1786
1787 (void) timeout_generic(CALLOUT_NORMAL,
1788 (void (*)(void *))zio_interrupt, zio, diff, 1, 0);
1789 }
1790
1791 return;
1792 }
1793 #endif
1794
1795 DTRACE_PROBE1(zio__delay__skip, zio_t *, zio);
1796 zio_interrupt(zio);
1797 }
1798
1799 /*
1800 * Execute the I/O pipeline until one of the following occurs:
1801 *
1802 * (1) the I/O completes
1803 * (2) the pipeline stalls waiting for dependent child I/Os
1804 * (3) the I/O issues, so we're waiting for an I/O completion interrupt
1805 * (4) the I/O is delegated by vdev-level caching or aggregation
1806 * (5) the I/O is deferred due to vdev-level queueing
1807 * (6) the I/O is handed off to another thread.
1808 *
1809 * In all cases, the pipeline stops whenever there's no CPU work; it never
1810 * burns a thread in cv_wait().
1811 *
1812 * There's no locking on io_stage because there's no legitimate way
1813 * for multiple threads to be attempting to process the same I/O.
1814 */
1815 static zio_pipe_stage_t *zio_pipeline[];
1816
1817 void
1818 zio_execute(zio_t *zio)
1819 {
1820 zio->io_executor = curthread;
1821
1822 ASSERT3U(zio->io_queued_timestamp, >, 0);
1823
1824 while (zio->io_stage < ZIO_STAGE_DONE) {
1825 enum zio_stage pipeline = zio->io_pipeline;
1826 enum zio_stage stage = zio->io_stage;
1827 int rv;
1828
1829 ASSERT(!MUTEX_HELD(&zio->io_lock));
1830 ASSERT(ISP2(stage));
1831 ASSERT(zio->io_stall == NULL);
1832
1833 do {
1834 stage <<= 1;
1835 } while ((stage & pipeline) == 0);
1836
1837 ASSERT(stage <= ZIO_STAGE_DONE);
1838
1839 /*
1840 * If we are in interrupt context and this pipeline stage
1841 * will grab a config lock that is held across I/O,
1842 * or may wait for an I/O that needs an interrupt thread
1843 * to complete, issue async to avoid deadlock.
1844 *
1845 * For VDEV_IO_START, we cut in line so that the io will
1846 * be sent to disk promptly.
1847 */
1848 if ((stage & ZIO_BLOCKING_STAGES) && zio->io_vd == NULL &&
1849 zio_taskq_member(zio, ZIO_TASKQ_INTERRUPT)) {
1850 boolean_t cut = (stage == ZIO_STAGE_VDEV_IO_START) ?
1851 zio_requeue_io_start_cut_in_line : B_FALSE;
1852 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, cut);
1853 return;
1854 }
1855
1856 zio->io_stage = stage;
1857 zio->io_pipeline_trace |= zio->io_stage;
1858 rv = zio_pipeline[highbit64(stage) - 1](zio);
1859
1860 if (rv == ZIO_PIPELINE_STOP)
1861 return;
1862
1863 ASSERT(rv == ZIO_PIPELINE_CONTINUE);
1864 }
1865 }
1866
1867 /*
1868 * ==========================================================================
1869 * Initiate I/O, either sync or async
1870 * ==========================================================================
1871 */
1872 int
1873 zio_wait(zio_t *zio)
1874 {
1875 int error;
1876
1877 ASSERT3P(zio->io_stage, ==, ZIO_STAGE_OPEN);
1878 ASSERT3P(zio->io_executor, ==, NULL);
1879
1880 zio->io_waiter = curthread;
1881 ASSERT0(zio->io_queued_timestamp);
1882 zio->io_queued_timestamp = gethrtime();
1883
1884 zio_execute(zio);
1885
1886 mutex_enter(&zio->io_lock);
1887 while (zio->io_executor != NULL)
1888 cv_wait(&zio->io_cv, &zio->io_lock);
1889 mutex_exit(&zio->io_lock);
1890
1891 error = zio->io_error;
1892 zio_destroy(zio);
1893
1894 return (error);
1895 }
1896
1897 void
1898 zio_nowait(zio_t *zio)
1899 {
1900 ASSERT3P(zio->io_executor, ==, NULL);
1901
1902 if (zio->io_child_type == ZIO_CHILD_LOGICAL &&
1903 zio_unique_parent(zio) == NULL) {
1904 /*
1905 * This is a logical async I/O with no parent to wait for it.
1906 * We add it to the spa_async_root_zio "Godfather" I/O which
1907 * will ensure they complete prior to unloading the pool.
1908 */
1909 spa_t *spa = zio->io_spa;
1910
1911 zio_add_child(spa->spa_async_zio_root[CPU_SEQID], zio);
1912 }
1913
1914 ASSERT0(zio->io_queued_timestamp);
1915 zio->io_queued_timestamp = gethrtime();
1916 zio_execute(zio);
1917 }
1918
1919 /*
1920 * ==========================================================================
1921 * Reexecute, cancel, or suspend/resume failed I/O
1922 * ==========================================================================
1923 */
1924
1925 static void
1926 zio_reexecute(zio_t *pio)
1927 {
1928 zio_t *cio, *cio_next;
1929
1930 ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL);
1931 ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN);
1932 ASSERT(pio->io_gang_leader == NULL);
1933 ASSERT(pio->io_gang_tree == NULL);
1934
1935 pio->io_flags = pio->io_orig_flags;
1936 pio->io_stage = pio->io_orig_stage;
1937 pio->io_pipeline = pio->io_orig_pipeline;
1938 pio->io_reexecute = 0;
1939 pio->io_flags |= ZIO_FLAG_REEXECUTED;
1940 pio->io_pipeline_trace = 0;
1941 pio->io_error = 0;
1942 for (int w = 0; w < ZIO_WAIT_TYPES; w++)
1943 pio->io_state[w] = 0;
1944 for (int c = 0; c < ZIO_CHILD_TYPES; c++)
1945 pio->io_child_error[c] = 0;
1946
1947 if (IO_IS_ALLOCATING(pio))
1948 BP_ZERO(pio->io_bp);
1949
1950 /*
1951 * As we reexecute pio's children, new children could be created.
1952 * New children go to the head of pio's io_child_list, however,
1953 * so we will (correctly) not reexecute them. The key is that
1954 * the remainder of pio's io_child_list, from 'cio_next' onward,
1955 * cannot be affected by any side effects of reexecuting 'cio'.
1956 */
1957 zio_link_t *zl = NULL;
1958 mutex_enter(&pio->io_lock);
1959 for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) {
1960 cio_next = zio_walk_children(pio, &zl);
1961 for (int w = 0; w < ZIO_WAIT_TYPES; w++)
1962 pio->io_children[cio->io_child_type][w]++;
1963 mutex_exit(&pio->io_lock);
1964 zio_reexecute(cio);
1965 mutex_enter(&pio->io_lock);
1966 }
1967 mutex_exit(&pio->io_lock);
1968
1969 /*
1970 * Now that all children have been reexecuted, execute the parent.
1971 * We don't reexecute "The Godfather" I/O here as it's the
1972 * responsibility of the caller to wait on it.
1973 */
1974 if (!(pio->io_flags & ZIO_FLAG_GODFATHER)) {
1975 pio->io_queued_timestamp = gethrtime();
1976 zio_execute(pio);
1977 }
1978 }
1979
1980 void
1981 zio_suspend(spa_t *spa, zio_t *zio, zio_suspend_reason_t reason)
1982 {
1983 if (spa_get_failmode(spa) == ZIO_FAILURE_MODE_PANIC)
1984 fm_panic("Pool '%s' has encountered an uncorrectable I/O "
1985 "failure and the failure mode property for this pool "
1986 "is set to panic.", spa_name(spa));
1987
1988 cmn_err(CE_WARN, "Pool '%s' has encountered an uncorrectable I/O "
1989 "failure and has been suspended; `zpool clear` will be required "
1990 "before the pool can be written to.", spa_name(spa));
1991
1992 zfs_ereport_post(FM_EREPORT_ZFS_IO_FAILURE, spa, NULL,
1993 NULL, NULL, 0, 0);
1994
1995 mutex_enter(&spa->spa_suspend_lock);
1996
1997 if (spa->spa_suspend_zio_root == NULL)
1998 spa->spa_suspend_zio_root = zio_root(spa, NULL, NULL,
1999 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
2000 ZIO_FLAG_GODFATHER);
2001
2002 spa->spa_suspended = reason;
2003
2004 if (zio != NULL) {
2005 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER));
2006 ASSERT(zio != spa->spa_suspend_zio_root);
2007 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
2008 ASSERT(zio_unique_parent(zio) == NULL);
2009 ASSERT(zio->io_stage == ZIO_STAGE_DONE);
2010 zio_add_child(spa->spa_suspend_zio_root, zio);
2011 }
2012
2013 mutex_exit(&spa->spa_suspend_lock);
2014 }
2015
2016 int
2017 zio_resume(spa_t *spa)
2018 {
2019 zio_t *pio;
2020
2021 /*
2022 * Reexecute all previously suspended i/o.
2023 */
2024 mutex_enter(&spa->spa_suspend_lock);
2025 spa->spa_suspended = ZIO_SUSPEND_NONE;
2026 cv_broadcast(&spa->spa_suspend_cv);
2027 pio = spa->spa_suspend_zio_root;
2028 spa->spa_suspend_zio_root = NULL;
2029 mutex_exit(&spa->spa_suspend_lock);
2030
2031 if (pio == NULL)
2032 return (0);
2033
2034 zio_reexecute(pio);
2035 return (zio_wait(pio));
2036 }
2037
2038 void
2039 zio_resume_wait(spa_t *spa)
2040 {
2041 mutex_enter(&spa->spa_suspend_lock);
2042 while (spa_suspended(spa))
2043 cv_wait(&spa->spa_suspend_cv, &spa->spa_suspend_lock);
2044 mutex_exit(&spa->spa_suspend_lock);
2045 }
2046
2047 /*
2048 * ==========================================================================
2049 * Gang blocks.
2050 *
2051 * A gang block is a collection of small blocks that looks to the DMU
2052 * like one large block. When zio_dva_allocate() cannot find a block
2053 * of the requested size, due to either severe fragmentation or the pool
2054 * being nearly full, it calls zio_write_gang_block() to construct the
2055 * block from smaller fragments.
2056 *
2057 * A gang block consists of a gang header (zio_gbh_phys_t) and up to
2058 * three (SPA_GBH_NBLKPTRS) gang members. The gang header is just like
2059 * an indirect block: it's an array of block pointers. It consumes
2060 * only one sector and hence is allocatable regardless of fragmentation.
2061 * The gang header's bps point to its gang members, which hold the data.
2062 *
2063 * Gang blocks are self-checksumming, using the bp's <vdev, offset, txg>
2064 * as the verifier to ensure uniqueness of the SHA256 checksum.
2065 * Critically, the gang block bp's blk_cksum is the checksum of the data,
2066 * not the gang header. This ensures that data block signatures (needed for
2067 * deduplication) are independent of how the block is physically stored.
2068 *
2069 * Gang blocks can be nested: a gang member may itself be a gang block.
2070 * Thus every gang block is a tree in which root and all interior nodes are
2071 * gang headers, and the leaves are normal blocks that contain user data.
2072 * The root of the gang tree is called the gang leader.
2073 *
2074 * To perform any operation (read, rewrite, free, claim) on a gang block,
2075 * zio_gang_assemble() first assembles the gang tree (minus data leaves)
2076 * in the io_gang_tree field of the original logical i/o by recursively
2077 * reading the gang leader and all gang headers below it. This yields
2078 * an in-core tree containing the contents of every gang header and the
2079 * bps for every constituent of the gang block.
2080 *
2081 * With the gang tree now assembled, zio_gang_issue() just walks the gang tree
2082 * and invokes a callback on each bp. To free a gang block, zio_gang_issue()
2083 * calls zio_free_gang() -- a trivial wrapper around zio_free() -- for each bp.
2084 * zio_claim_gang() provides a similarly trivial wrapper for zio_claim().
2085 * zio_read_gang() is a wrapper around zio_read() that omits reading gang
2086 * headers, since we already have those in io_gang_tree. zio_rewrite_gang()
2087 * performs a zio_rewrite() of the data or, for gang headers, a zio_rewrite()
2088 * of the gang header plus zio_checksum_compute() of the data to update the
2089 * gang header's blk_cksum as described above.
2090 *
2091 * The two-phase assemble/issue model solves the problem of partial failure --
2092 * what if you'd freed part of a gang block but then couldn't read the
2093 * gang header for another part? Assembling the entire gang tree first
2094 * ensures that all the necessary gang header I/O has succeeded before
2095 * starting the actual work of free, claim, or write. Once the gang tree
2096 * is assembled, free and claim are in-memory operations that cannot fail.
2097 *
2098 * In the event that a gang write fails, zio_dva_unallocate() walks the
2099 * gang tree to immediately free (i.e. insert back into the space map)
2100 * everything we've allocated. This ensures that we don't get ENOSPC
2101 * errors during repeated suspend/resume cycles due to a flaky device.
2102 *
2103 * Gang rewrites only happen during sync-to-convergence. If we can't assemble
2104 * the gang tree, we won't modify the block, so we can safely defer the free
2105 * (knowing that the block is still intact). If we *can* assemble the gang
2106 * tree, then even if some of the rewrites fail, zio_dva_unallocate() will free
2107 * each constituent bp and we can allocate a new block on the next sync pass.
2108 *
2109 * In all cases, the gang tree allows complete recovery from partial failure.
2110 * ==========================================================================
2111 */
2112
2113 static void
2114 zio_gang_issue_func_done(zio_t *zio)
2115 {
2116 abd_put(zio->io_abd);
2117 }
2118
2119 static zio_t *
2120 zio_read_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data,
2121 uint64_t offset)
2122 {
2123 if (gn != NULL)
2124 return (pio);
2125
2126 return (zio_read(pio, pio->io_spa, bp, abd_get_offset(data, offset),
2127 BP_GET_PSIZE(bp), zio_gang_issue_func_done,
2128 NULL, pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio),
2129 &pio->io_bookmark));
2130 }
2131
2132 static zio_t *
2133 zio_rewrite_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data,
2134 uint64_t offset)
2135 {
2136 zio_t *zio;
2137
2138 if (gn != NULL) {
2139 abd_t *gbh_abd =
2140 abd_get_from_buf(gn->gn_gbh, SPA_GANGBLOCKSIZE);
2141 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp,
2142 gbh_abd, SPA_GANGBLOCKSIZE, zio_gang_issue_func_done, NULL,
2143 pio->io_priority, ZIO_GANG_CHILD_FLAGS(pio),
2144 &pio->io_bookmark);
2145 /*
2146 * As we rewrite each gang header, the pipeline will compute
2147 * a new gang block header checksum for it; but no one will
2148 * compute a new data checksum, so we do that here. The one
2149 * exception is the gang leader: the pipeline already computed
2150 * its data checksum because that stage precedes gang assembly.
2151 * (Presently, nothing actually uses interior data checksums;
2152 * this is just good hygiene.)
2153 */
2154 if (gn != pio->io_gang_leader->io_gang_tree) {
2155 abd_t *buf = abd_get_offset(data, offset);
2156
2157 zio_checksum_compute(zio, BP_GET_CHECKSUM(bp),
2158 buf, BP_GET_PSIZE(bp));
2159
2160 abd_put(buf);
2161 }
2162 /*
2163 * If we are here to damage data for testing purposes,
2164 * leave the GBH alone so that we can detect the damage.
2165 */
2166 if (pio->io_gang_leader->io_flags & ZIO_FLAG_INDUCE_DAMAGE)
2167 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES;
2168 } else {
2169 zio = zio_rewrite(pio, pio->io_spa, pio->io_txg, bp,
2170 abd_get_offset(data, offset), BP_GET_PSIZE(bp),
2171 zio_gang_issue_func_done, NULL, pio->io_priority,
2172 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark);
2173 }
2174
2175 return (zio);
2176 }
2177
2178 /* ARGSUSED */
2179 static zio_t *
2180 zio_free_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data,
2181 uint64_t offset)
2182 {
2183 return (zio_free_sync(pio, pio->io_spa, pio->io_txg, bp,
2184 ZIO_GANG_CHILD_FLAGS(pio)));
2185 }
2186
2187 /* ARGSUSED */
2188 static zio_t *
2189 zio_claim_gang(zio_t *pio, blkptr_t *bp, zio_gang_node_t *gn, abd_t *data,
2190 uint64_t offset)
2191 {
2192 return (zio_claim(pio, pio->io_spa, pio->io_txg, bp,
2193 NULL, NULL, ZIO_GANG_CHILD_FLAGS(pio)));
2194 }
2195
2196 static zio_gang_issue_func_t *zio_gang_issue_func[ZIO_TYPES] = {
2197 NULL,
2198 zio_read_gang,
2199 zio_rewrite_gang,
2200 zio_free_gang,
2201 zio_claim_gang,
2202 NULL
2203 };
2204
2205 static void zio_gang_tree_assemble_done(zio_t *zio);
2206
2207 static zio_gang_node_t *
2208 zio_gang_node_alloc(zio_gang_node_t **gnpp)
2209 {
2210 zio_gang_node_t *gn;
2211
2212 ASSERT(*gnpp == NULL);
2213
2214 gn = kmem_zalloc(sizeof (*gn), KM_SLEEP);
2215 gn->gn_gbh = zio_buf_alloc(SPA_GANGBLOCKSIZE);
2216 *gnpp = gn;
2217
2218 return (gn);
2219 }
2220
2221 static void
2222 zio_gang_node_free(zio_gang_node_t **gnpp)
2223 {
2224 zio_gang_node_t *gn = *gnpp;
2225
2226 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++)
2227 ASSERT(gn->gn_child[g] == NULL);
2228
2229 zio_buf_free(gn->gn_gbh, SPA_GANGBLOCKSIZE);
2230 kmem_free(gn, sizeof (*gn));
2231 *gnpp = NULL;
2232 }
2233
2234 static void
2235 zio_gang_tree_free(zio_gang_node_t **gnpp)
2236 {
2237 zio_gang_node_t *gn = *gnpp;
2238
2239 if (gn == NULL)
2240 return;
2241
2242 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++)
2243 zio_gang_tree_free(&gn->gn_child[g]);
2244
2245 zio_gang_node_free(gnpp);
2246 }
2247
2248 static void
2249 zio_gang_tree_assemble(zio_t *gio, blkptr_t *bp, zio_gang_node_t **gnpp)
2250 {
2251 zio_gang_node_t *gn = zio_gang_node_alloc(gnpp);
2252 abd_t *gbh_abd = abd_get_from_buf(gn->gn_gbh, SPA_GANGBLOCKSIZE);
2253
2254 ASSERT(gio->io_gang_leader == gio);
2255 ASSERT(BP_IS_GANG(bp));
2256
2257 zio_nowait(zio_read(gio, gio->io_spa, bp, gbh_abd, SPA_GANGBLOCKSIZE,
2258 zio_gang_tree_assemble_done, gn, gio->io_priority,
2259 ZIO_GANG_CHILD_FLAGS(gio), &gio->io_bookmark));
2260 }
2261
2262 static void
2263 zio_gang_tree_assemble_done(zio_t *zio)
2264 {
2265 zio_t *gio = zio->io_gang_leader;
2266 zio_gang_node_t *gn = zio->io_private;
2267 blkptr_t *bp = zio->io_bp;
2268
2269 ASSERT(gio == zio_unique_parent(zio));
2270 ASSERT(zio->io_child_count == 0);
2271
2272 if (zio->io_error)
2273 return;
2274
2275 /* this ABD was created from a linear buf in zio_gang_tree_assemble */
2276 if (BP_SHOULD_BYTESWAP(bp))
2277 byteswap_uint64_array(abd_to_buf(zio->io_abd), zio->io_size);
2278
2279 ASSERT3P(abd_to_buf(zio->io_abd), ==, gn->gn_gbh);
2280 ASSERT(zio->io_size == SPA_GANGBLOCKSIZE);
2281 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC);
2282
2283 abd_put(zio->io_abd);
2284
2285 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) {
2286 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g];
2287 if (!BP_IS_GANG(gbp))
2288 continue;
2289 zio_gang_tree_assemble(gio, gbp, &gn->gn_child[g]);
2290 }
2291 }
2292
2293 static void
2294 zio_gang_tree_issue(zio_t *pio, zio_gang_node_t *gn, blkptr_t *bp, abd_t *data,
2295 uint64_t offset)
2296 {
2297 zio_t *gio = pio->io_gang_leader;
2298 zio_t *zio;
2299
2300 ASSERT(BP_IS_GANG(bp) == !!gn);
2301 ASSERT(BP_GET_CHECKSUM(bp) == BP_GET_CHECKSUM(gio->io_bp));
2302 ASSERT(BP_GET_LSIZE(bp) == BP_GET_PSIZE(bp) || gn == gio->io_gang_tree);
2303
2304 /*
2305 * If you're a gang header, your data is in gn->gn_gbh.
2306 * If you're a gang member, your data is in 'data' and gn == NULL.
2307 */
2308 zio = zio_gang_issue_func[gio->io_type](pio, bp, gn, data, offset);
2309
2310 if (gn != NULL) {
2311 ASSERT(gn->gn_gbh->zg_tail.zec_magic == ZEC_MAGIC);
2312
2313 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) {
2314 blkptr_t *gbp = &gn->gn_gbh->zg_blkptr[g];
2315 if (BP_IS_HOLE(gbp))
2316 continue;
2317 zio_gang_tree_issue(zio, gn->gn_child[g], gbp, data,
2318 offset);
2319 offset += BP_GET_PSIZE(gbp);
2320 }
2321 }
2322
2323 if (gn == gio->io_gang_tree)
2324 ASSERT3U(gio->io_size, ==, offset);
2325
2326 if (zio != pio)
2327 zio_nowait(zio);
2328 }
2329
2330 static int
2331 zio_gang_assemble(zio_t *zio)
2332 {
2333 blkptr_t *bp = zio->io_bp;
2334
2335 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == NULL);
2336 ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
2337
2338 zio->io_gang_leader = zio;
2339
2340 zio_gang_tree_assemble(zio, bp, &zio->io_gang_tree);
2341
2342 return (ZIO_PIPELINE_CONTINUE);
2343 }
2344
2345 static int
2346 zio_gang_issue(zio_t *zio)
2347 {
2348 blkptr_t *bp = zio->io_bp;
2349
2350 if (zio_wait_for_children(zio, ZIO_CHILD_GANG_BIT, ZIO_WAIT_DONE)) {
2351 return (ZIO_PIPELINE_STOP);
2352 }
2353
2354 ASSERT(BP_IS_GANG(bp) && zio->io_gang_leader == zio);
2355 ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
2356
2357 if (zio->io_child_error[ZIO_CHILD_GANG] == 0)
2358 zio_gang_tree_issue(zio, zio->io_gang_tree, bp, zio->io_abd,
2359 0);
2360 else
2361 zio_gang_tree_free(&zio->io_gang_tree);
2362
2363 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
2364
2365 return (ZIO_PIPELINE_CONTINUE);
2366 }
2367
2368 static void
2369 zio_write_gang_member_ready(zio_t *zio)
2370 {
2371 zio_t *pio = zio_unique_parent(zio);
2372 zio_t *gio = zio->io_gang_leader;
2373 dva_t *cdva = zio->io_bp->blk_dva;
2374 dva_t *pdva = pio->io_bp->blk_dva;
2375 uint64_t asize;
2376
2377 if (BP_IS_HOLE(zio->io_bp))
2378 return;
2379
2380 ASSERT(BP_IS_HOLE(&zio->io_bp_orig));
2381
2382 ASSERT(zio->io_child_type == ZIO_CHILD_GANG);
2383 ASSERT3U(zio->io_prop.zp_copies, ==, gio->io_prop.zp_copies);
2384 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(zio->io_bp));
2385 ASSERT3U(pio->io_prop.zp_copies, <=, BP_GET_NDVAS(pio->io_bp));
2386 ASSERT3U(BP_GET_NDVAS(zio->io_bp), <=, BP_GET_NDVAS(pio->io_bp));
2387
2388 mutex_enter(&pio->io_lock);
2389 for (int d = 0; d < BP_GET_NDVAS(zio->io_bp); d++) {
2390 ASSERT(DVA_GET_GANG(&pdva[d]));
2391 asize = DVA_GET_ASIZE(&pdva[d]);
2392 asize += DVA_GET_ASIZE(&cdva[d]);
2393 DVA_SET_ASIZE(&pdva[d], asize);
2394 }
2395 mutex_exit(&pio->io_lock);
2396 }
2397
2398 static void
2399 zio_write_gang_done(zio_t *zio)
2400 {
2401 /*
2402 * The io_abd field will be NULL for a zio with no data. The io_flags
2403 * will initially have the ZIO_FLAG_NODATA bit flag set, but we can't
2404 * check for it here as it is cleared in zio_ready.
2405 */
2406 if (zio->io_abd != NULL)
2407 abd_put(zio->io_abd);
2408 }
2409
2410 static int
2411 zio_write_gang_block(zio_t *pio)
2412 {
2413 spa_t *spa = pio->io_spa;
2414 metaslab_class_t *mc = spa_normal_class(spa);
2415 blkptr_t *bp = pio->io_bp;
2416 zio_t *gio = pio->io_gang_leader;
2417 zio_t *zio;
2418 zio_gang_node_t *gn, **gnpp;
2419 zio_gbh_phys_t *gbh;
2420 abd_t *gbh_abd;
2421 uint64_t txg = pio->io_txg;
2422 uint64_t resid = pio->io_size;
2423 uint64_t lsize;
2424 int copies = gio->io_prop.zp_copies;
2425 int gbh_copies = MIN(copies + 1, spa_max_replication(spa));
2426 zio_prop_t zp;
2427 int error;
2428 boolean_t has_data = !(pio->io_flags & ZIO_FLAG_NODATA);
2429
2430 /*
2431 * encrypted blocks need DVA[2] free so encrypted gang headers can't
2432 * have a third copy.
2433 */
2434 if (gio->io_prop.zp_encrypt && gbh_copies >= SPA_DVAS_PER_BP)
2435 gbh_copies = SPA_DVAS_PER_BP - 1;
2436
2437 int flags = METASLAB_HINTBP_FAVOR | METASLAB_GANG_HEADER;
2438 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) {
2439 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE);
2440 ASSERT(has_data);
2441
2442 flags |= METASLAB_ASYNC_ALLOC;
2443 VERIFY(zfs_refcount_held(&mc->mc_alloc_slots[pio->io_allocator],
2444 pio));
2445
2446 /*
2447 * The logical zio has already placed a reservation for
2448 * 'copies' allocation slots but gang blocks may require
2449 * additional copies. These additional copies
2450 * (i.e. gbh_copies - copies) are guaranteed to succeed
2451 * since metaslab_class_throttle_reserve() always allows
2452 * additional reservations for gang blocks.
2453 */
2454 VERIFY(metaslab_class_throttle_reserve(mc, gbh_copies - copies,
2455 pio->io_allocator, pio, flags));
2456 }
2457
2458 error = metaslab_alloc(spa, mc, SPA_GANGBLOCKSIZE,
2459 bp, gbh_copies, txg, pio == gio ? NULL : gio->io_bp, flags,
2460 &pio->io_alloc_list, pio, pio->io_allocator);
2461 if (error) {
2462 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) {
2463 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE);
2464 ASSERT(has_data);
2465
2466 /*
2467 * If we failed to allocate the gang block header then
2468 * we remove any additional allocation reservations that
2469 * we placed here. The original reservation will
2470 * be removed when the logical I/O goes to the ready
2471 * stage.
2472 */
2473 metaslab_class_throttle_unreserve(mc,
2474 gbh_copies - copies, pio->io_allocator, pio);
2475 }
2476 pio->io_error = error;
2477 return (ZIO_PIPELINE_CONTINUE);
2478 }
2479
2480 if (pio == gio) {
2481 gnpp = &gio->io_gang_tree;
2482 } else {
2483 gnpp = pio->io_private;
2484 ASSERT(pio->io_ready == zio_write_gang_member_ready);
2485 }
2486
2487 gn = zio_gang_node_alloc(gnpp);
2488 gbh = gn->gn_gbh;
2489 bzero(gbh, SPA_GANGBLOCKSIZE);
2490 gbh_abd = abd_get_from_buf(gbh, SPA_GANGBLOCKSIZE);
2491
2492 /*
2493 * Create the gang header.
2494 */
2495 zio = zio_rewrite(pio, spa, txg, bp, gbh_abd, SPA_GANGBLOCKSIZE,
2496 zio_write_gang_done, NULL, pio->io_priority,
2497 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark);
2498
2499 /*
2500 * Create and nowait the gang children.
2501 */
2502 for (int g = 0; resid != 0; resid -= lsize, g++) {
2503 lsize = P2ROUNDUP(resid / (SPA_GBH_NBLKPTRS - g),
2504 SPA_MINBLOCKSIZE);
2505 ASSERT(lsize >= SPA_MINBLOCKSIZE && lsize <= resid);
2506
2507 zp.zp_checksum = gio->io_prop.zp_checksum;
2508 zp.zp_compress = ZIO_COMPRESS_OFF;
2509 zp.zp_type = DMU_OT_NONE;
2510 zp.zp_level = 0;
2511 zp.zp_copies = gio->io_prop.zp_copies;
2512 zp.zp_dedup = B_FALSE;
2513 zp.zp_dedup_verify = B_FALSE;
2514 zp.zp_nopwrite = B_FALSE;
2515 zp.zp_encrypt = gio->io_prop.zp_encrypt;
2516 zp.zp_byteorder = gio->io_prop.zp_byteorder;
2517 bzero(zp.zp_salt, ZIO_DATA_SALT_LEN);
2518 bzero(zp.zp_iv, ZIO_DATA_IV_LEN);
2519 bzero(zp.zp_mac, ZIO_DATA_MAC_LEN);
2520
2521 zio_t *cio = zio_write(zio, spa, txg, &gbh->zg_blkptr[g],
2522 has_data ? abd_get_offset(pio->io_abd, pio->io_size -
2523 resid) : NULL, lsize, lsize, &zp,
2524 zio_write_gang_member_ready, NULL, NULL,
2525 zio_write_gang_done, &gn->gn_child[g], pio->io_priority,
2526 ZIO_GANG_CHILD_FLAGS(pio), &pio->io_bookmark);
2527
2528 if (pio->io_flags & ZIO_FLAG_IO_ALLOCATING) {
2529 ASSERT(pio->io_priority == ZIO_PRIORITY_ASYNC_WRITE);
2530 ASSERT(has_data);
2531
2532 /*
2533 * Gang children won't throttle but we should
2534 * account for their work, so reserve an allocation
2535 * slot for them here.
2536 */
2537 VERIFY(metaslab_class_throttle_reserve(mc,
2538 zp.zp_copies, cio->io_allocator, cio, flags));
2539 }
2540 zio_nowait(cio);
2541 }
2542
2543 /*
2544 * Set pio's pipeline to just wait for zio to finish.
2545 */
2546 pio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
2547
2548 zio_nowait(zio);
2549
2550 return (ZIO_PIPELINE_CONTINUE);
2551 }
2552
2553 /*
2554 * The zio_nop_write stage in the pipeline determines if allocating a
2555 * new bp is necessary. The nopwrite feature can handle writes in
2556 * either syncing or open context (i.e. zil writes) and as a result is
2557 * mutually exclusive with dedup.
2558 *
2559 * By leveraging a cryptographically secure checksum, such as SHA256, we
2560 * can compare the checksums of the new data and the old to determine if
2561 * allocating a new block is required. Note that our requirements for
2562 * cryptographic strength are fairly weak: there can't be any accidental
2563 * hash collisions, but we don't need to be secure against intentional
2564 * (malicious) collisions. To trigger a nopwrite, you have to be able
2565 * to write the file to begin with, and triggering an incorrect (hash
2566 * collision) nopwrite is no worse than simply writing to the file.
2567 * That said, there are no known attacks against the checksum algorithms
2568 * used for nopwrite, assuming that the salt and the checksums
2569 * themselves remain secret.
2570 */
2571 static int
2572 zio_nop_write(zio_t *zio)
2573 {
2574 blkptr_t *bp = zio->io_bp;
2575 blkptr_t *bp_orig = &zio->io_bp_orig;
2576 zio_prop_t *zp = &zio->io_prop;
2577
2578 ASSERT(BP_GET_LEVEL(bp) == 0);
2579 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE));
2580 ASSERT(zp->zp_nopwrite);
2581 ASSERT(!zp->zp_dedup);
2582 ASSERT(zio->io_bp_override == NULL);
2583 ASSERT(IO_IS_ALLOCATING(zio));
2584
2585 /*
2586 * Check to see if the original bp and the new bp have matching
2587 * characteristics (i.e. same checksum, compression algorithms, etc).
2588 * If they don't then just continue with the pipeline which will
2589 * allocate a new bp.
2590 */
2591 if (BP_IS_HOLE(bp_orig) ||
2592 !(zio_checksum_table[BP_GET_CHECKSUM(bp)].ci_flags &
2593 ZCHECKSUM_FLAG_NOPWRITE) ||
2594 BP_IS_ENCRYPTED(bp) || BP_IS_ENCRYPTED(bp_orig) ||
2595 BP_GET_CHECKSUM(bp) != BP_GET_CHECKSUM(bp_orig) ||
2596 BP_GET_COMPRESS(bp) != BP_GET_COMPRESS(bp_orig) ||
2597 BP_GET_DEDUP(bp) != BP_GET_DEDUP(bp_orig) ||
2598 zp->zp_copies != BP_GET_NDVAS(bp_orig))
2599 return (ZIO_PIPELINE_CONTINUE);
2600
2601 /*
2602 * If the checksums match then reset the pipeline so that we
2603 * avoid allocating a new bp and issuing any I/O.
2604 */
2605 if (ZIO_CHECKSUM_EQUAL(bp->blk_cksum, bp_orig->blk_cksum)) {
2606 ASSERT(zio_checksum_table[zp->zp_checksum].ci_flags &
2607 ZCHECKSUM_FLAG_NOPWRITE);
2608 ASSERT3U(BP_GET_PSIZE(bp), ==, BP_GET_PSIZE(bp_orig));
2609 ASSERT3U(BP_GET_LSIZE(bp), ==, BP_GET_LSIZE(bp_orig));
2610 ASSERT(zp->zp_compress != ZIO_COMPRESS_OFF);
2611 ASSERT(bcmp(&bp->blk_prop, &bp_orig->blk_prop,
2612 sizeof (uint64_t)) == 0);
2613
2614 *bp = *bp_orig;
2615 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
2616 zio->io_flags |= ZIO_FLAG_NOPWRITE;
2617 }
2618
2619 return (ZIO_PIPELINE_CONTINUE);
2620 }
2621
2622 /*
2623 * ==========================================================================
2624 * Dedup
2625 * ==========================================================================
2626 */
2627 static void
2628 zio_ddt_child_read_done(zio_t *zio)
2629 {
2630 blkptr_t *bp = zio->io_bp;
2631 ddt_entry_t *dde = zio->io_private;
2632 ddt_phys_t *ddp;
2633 zio_t *pio = zio_unique_parent(zio);
2634
2635 mutex_enter(&pio->io_lock);
2636 ddp = ddt_phys_select(dde, bp);
2637 if (zio->io_error == 0)
2638 ddt_phys_clear(ddp); /* this ddp doesn't need repair */
2639
2640 if (zio->io_error == 0 && dde->dde_repair_abd == NULL)
2641 dde->dde_repair_abd = zio->io_abd;
2642 else
2643 abd_free(zio->io_abd);
2644 mutex_exit(&pio->io_lock);
2645 }
2646
2647 static int
2648 zio_ddt_read_start(zio_t *zio)
2649 {
2650 blkptr_t *bp = zio->io_bp;
2651
2652 ASSERT(BP_GET_DEDUP(bp));
2653 ASSERT(BP_GET_PSIZE(bp) == zio->io_size);
2654 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
2655
2656 if (zio->io_child_error[ZIO_CHILD_DDT]) {
2657 ddt_t *ddt = ddt_select(zio->io_spa, bp);
2658 ddt_entry_t *dde = ddt_repair_start(ddt, bp);
2659 ddt_phys_t *ddp = dde->dde_phys;
2660 ddt_phys_t *ddp_self = ddt_phys_select(dde, bp);
2661 blkptr_t blk;
2662
2663 ASSERT(zio->io_vsd == NULL);
2664 zio->io_vsd = dde;
2665
2666 if (ddp_self == NULL)
2667 return (ZIO_PIPELINE_CONTINUE);
2668
2669 for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
2670 if (ddp->ddp_phys_birth == 0 || ddp == ddp_self)
2671 continue;
2672 ddt_bp_create(ddt->ddt_checksum, &dde->dde_key, ddp,
2673 &blk);
2674 zio_nowait(zio_read(zio, zio->io_spa, &blk,
2675 abd_alloc_for_io(zio->io_size, B_TRUE),
2676 zio->io_size, zio_ddt_child_read_done, dde,
2677 zio->io_priority, ZIO_DDT_CHILD_FLAGS(zio) |
2678 ZIO_FLAG_DONT_PROPAGATE, &zio->io_bookmark));
2679 }
2680 return (ZIO_PIPELINE_CONTINUE);
2681 }
2682
2683 zio_nowait(zio_read(zio, zio->io_spa, bp,
2684 zio->io_abd, zio->io_size, NULL, NULL, zio->io_priority,
2685 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark));
2686
2687 return (ZIO_PIPELINE_CONTINUE);
2688 }
2689
2690 static int
2691 zio_ddt_read_done(zio_t *zio)
2692 {
2693 blkptr_t *bp = zio->io_bp;
2694
2695 if (zio_wait_for_children(zio, ZIO_CHILD_DDT_BIT, ZIO_WAIT_DONE)) {
2696 return (ZIO_PIPELINE_STOP);
2697 }
2698
2699 ASSERT(BP_GET_DEDUP(bp));
2700 ASSERT(BP_GET_PSIZE(bp) == zio->io_size);
2701 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
2702
2703 if (zio->io_child_error[ZIO_CHILD_DDT]) {
2704 ddt_t *ddt = ddt_select(zio->io_spa, bp);
2705 ddt_entry_t *dde = zio->io_vsd;
2706 if (ddt == NULL) {
2707 ASSERT(spa_load_state(zio->io_spa) != SPA_LOAD_NONE);
2708 return (ZIO_PIPELINE_CONTINUE);
2709 }
2710 if (dde == NULL) {
2711 zio->io_stage = ZIO_STAGE_DDT_READ_START >> 1;
2712 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_FALSE);
2713 return (ZIO_PIPELINE_STOP);
2714 }
2715 if (dde->dde_repair_abd != NULL) {
2716 abd_copy(zio->io_abd, dde->dde_repair_abd,
2717 zio->io_size);
2718 zio->io_child_error[ZIO_CHILD_DDT] = 0;
2719 }
2720 ddt_repair_done(ddt, dde);
2721 zio->io_vsd = NULL;
2722 }
2723
2724 ASSERT(zio->io_vsd == NULL);
2725
2726 return (ZIO_PIPELINE_CONTINUE);
2727 }
2728
2729 static boolean_t
2730 zio_ddt_collision(zio_t *zio, ddt_t *ddt, ddt_entry_t *dde)
2731 {
2732 spa_t *spa = zio->io_spa;
2733 boolean_t do_raw = !!(zio->io_flags & ZIO_FLAG_RAW);
2734
2735 /* We should never get a raw, override zio */
2736 ASSERT(!(zio->io_bp_override && do_raw));
2737
2738 /*
2739 * Note: we compare the original data, not the transformed data,
2740 * because when zio->io_bp is an override bp, we will not have
2741 * pushed the I/O transforms. That's an important optimization
2742 * because otherwise we'd compress/encrypt all dmu_sync() data twice.
2743 * However, we should never get a raw, override zio so in these
2744 * cases we can compare the io_data directly. This is useful because
2745 * it allows us to do dedup verification even if we don't have access
2746 * to the original data (for instance, if the encryption keys aren't
2747 * loaded).
2748 */
2749
2750 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) {
2751 zio_t *lio = dde->dde_lead_zio[p];
2752
2753 if (lio != NULL && do_raw) {
2754 return (lio->io_size != zio->io_size ||
2755 abd_cmp(zio->io_abd, lio->io_abd,
2756 zio->io_size) != 0);
2757 } else if (lio != NULL) {
2758 return (lio->io_orig_size != zio->io_orig_size ||
2759 abd_cmp(zio->io_orig_abd, lio->io_orig_abd,
2760 zio->io_orig_size) != 0);
2761 }
2762 }
2763
2764 for (int p = DDT_PHYS_SINGLE; p <= DDT_PHYS_TRIPLE; p++) {
2765 ddt_phys_t *ddp = &dde->dde_phys[p];
2766
2767 if (ddp->ddp_phys_birth != 0 && do_raw) {
2768 blkptr_t blk = *zio->io_bp;
2769 uint64_t psize;
2770 abd_t *tmpabd;
2771 int error;
2772
2773 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth);
2774 psize = BP_GET_PSIZE(&blk);
2775
2776 if (psize != zio->io_size)
2777 return (B_TRUE);
2778
2779 ddt_exit(ddt);
2780
2781 tmpabd = abd_alloc_for_io(psize, B_TRUE);
2782
2783 error = zio_wait(zio_read(NULL, spa, &blk, tmpabd,
2784 psize, NULL, NULL, ZIO_PRIORITY_SYNC_READ,
2785 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE |
2786 ZIO_FLAG_RAW, &zio->io_bookmark));
2787
2788 if (error == 0) {
2789 if (abd_cmp(tmpabd, zio->io_abd, psize) != 0)
2790 error = SET_ERROR(ENOENT);
2791 }
2792
2793 abd_free(tmpabd);
2794 ddt_enter(ddt);
2795 return (error != 0);
2796 } else if (ddp->ddp_phys_birth != 0) {
2797 arc_buf_t *abuf = NULL;
2798 arc_flags_t aflags = ARC_FLAG_WAIT;
2799 int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE;
2800 blkptr_t blk = *zio->io_bp;
2801 int error;
2802
2803 ddt_bp_fill(ddp, &blk, ddp->ddp_phys_birth);
2804
2805 if (BP_GET_LSIZE(&blk) != zio->io_orig_size)
2806 return (B_TRUE);
2807
2808 ddt_exit(ddt);
2809
2810 /*
2811 * Intuitively, it would make more sense to compare
2812 * io_abd than io_orig_abd in the raw case since you
2813 * don't want to look at any transformations that have
2814 * happened to the data. However, for raw I/Os the
2815 * data will actually be the same in io_abd and
2816 * io_orig_abd, so all we have to do is issue this as
2817 * a raw ARC read.
2818 */
2819 if (do_raw) {
2820 zio_flags |= ZIO_FLAG_RAW;
2821 ASSERT3U(zio->io_size, ==, zio->io_orig_size);
2822 ASSERT0(abd_cmp(zio->io_abd, zio->io_orig_abd,
2823 zio->io_size));
2824 ASSERT3P(zio->io_transform_stack, ==, NULL);
2825 }
2826
2827 error = arc_read(NULL, spa, &blk,
2828 arc_getbuf_func, &abuf, ZIO_PRIORITY_SYNC_READ,
2829 zio_flags, &aflags, &zio->io_bookmark);
2830
2831 if (error == 0) {
2832 if (abd_cmp_buf(zio->io_orig_abd, abuf->b_data,
2833 zio->io_orig_size) != 0)
2834 error = SET_ERROR(ENOENT);
2835 arc_buf_destroy(abuf, &abuf);
2836 }
2837
2838 ddt_enter(ddt);
2839 return (error != 0);
2840 }
2841 }
2842
2843 return (B_FALSE);
2844 }
2845
2846 static void
2847 zio_ddt_child_write_ready(zio_t *zio)
2848 {
2849 int p = zio->io_prop.zp_copies;
2850 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp);
2851 ddt_entry_t *dde = zio->io_private;
2852 ddt_phys_t *ddp = &dde->dde_phys[p];
2853 zio_t *pio;
2854
2855 if (zio->io_error)
2856 return;
2857
2858 ddt_enter(ddt);
2859
2860 ASSERT(dde->dde_lead_zio[p] == zio);
2861
2862 ddt_phys_fill(ddp, zio->io_bp);
2863
2864 zio_link_t *zl = NULL;
2865 while ((pio = zio_walk_parents(zio, &zl)) != NULL)
2866 ddt_bp_fill(ddp, pio->io_bp, zio->io_txg);
2867
2868 ddt_exit(ddt);
2869 }
2870
2871 static void
2872 zio_ddt_child_write_done(zio_t *zio)
2873 {
2874 int p = zio->io_prop.zp_copies;
2875 ddt_t *ddt = ddt_select(zio->io_spa, zio->io_bp);
2876 ddt_entry_t *dde = zio->io_private;
2877 ddt_phys_t *ddp = &dde->dde_phys[p];
2878
2879 ddt_enter(ddt);
2880
2881 ASSERT(ddp->ddp_refcnt == 0);
2882 ASSERT(dde->dde_lead_zio[p] == zio);
2883 dde->dde_lead_zio[p] = NULL;
2884
2885 if (zio->io_error == 0) {
2886 zio_link_t *zl = NULL;
2887 while (zio_walk_parents(zio, &zl) != NULL)
2888 ddt_phys_addref(ddp);
2889 } else {
2890 ddt_phys_clear(ddp);
2891 }
2892
2893 ddt_exit(ddt);
2894 }
2895
2896 static void
2897 zio_ddt_ditto_write_done(zio_t *zio)
2898 {
2899 int p = DDT_PHYS_DITTO;
2900 zio_prop_t *zp = &zio->io_prop;
2901 blkptr_t *bp = zio->io_bp;
2902 ddt_t *ddt = ddt_select(zio->io_spa, bp);
2903 ddt_entry_t *dde = zio->io_private;
2904 ddt_phys_t *ddp = &dde->dde_phys[p];
2905 ddt_key_t *ddk = &dde->dde_key;
2906
2907 ddt_enter(ddt);
2908
2909 ASSERT(ddp->ddp_refcnt == 0);
2910 ASSERT(dde->dde_lead_zio[p] == zio);
2911 dde->dde_lead_zio[p] = NULL;
2912
2913 if (zio->io_error == 0) {
2914 ASSERT(ZIO_CHECKSUM_EQUAL(bp->blk_cksum, ddk->ddk_cksum));
2915 ASSERT(zp->zp_copies < SPA_DVAS_PER_BP);
2916 ASSERT(zp->zp_copies == BP_GET_NDVAS(bp) - BP_IS_GANG(bp));
2917 if (ddp->ddp_phys_birth != 0)
2918 ddt_phys_free(ddt, ddk, ddp, zio->io_txg);
2919 ddt_phys_fill(ddp, bp);
2920 }
2921
2922 ddt_exit(ddt);
2923 }
2924
2925 static int
2926 zio_ddt_write(zio_t *zio)
2927 {
2928 spa_t *spa = zio->io_spa;
2929 blkptr_t *bp = zio->io_bp;
2930 uint64_t txg = zio->io_txg;
2931 zio_prop_t *zp = &zio->io_prop;
2932 int p = zp->zp_copies;
2933 int ditto_copies;
2934 zio_t *cio = NULL;
2935 zio_t *dio = NULL;
2936 ddt_t *ddt = ddt_select(spa, bp);
2937 ddt_entry_t *dde;
2938 ddt_phys_t *ddp;
2939
2940 ASSERT(BP_GET_DEDUP(bp));
2941 ASSERT(BP_GET_CHECKSUM(bp) == zp->zp_checksum);
2942 ASSERT(BP_IS_HOLE(bp) || zio->io_bp_override);
2943 ASSERT(!(zio->io_bp_override && (zio->io_flags & ZIO_FLAG_RAW)));
2944
2945 ddt_enter(ddt);
2946 dde = ddt_lookup(ddt, bp, B_TRUE);
2947 ddp = &dde->dde_phys[p];
2948
2949 if (zp->zp_dedup_verify && zio_ddt_collision(zio, ddt, dde)) {
2950 /*
2951 * If we're using a weak checksum, upgrade to a strong checksum
2952 * and try again. If we're already using a strong checksum,
2953 * we can't resolve it, so just convert to an ordinary write.
2954 * (And automatically e-mail a paper to Nature?)
2955 */
2956 if (!(zio_checksum_table[zp->zp_checksum].ci_flags &
2957 ZCHECKSUM_FLAG_DEDUP)) {
2958 zp->zp_checksum = spa_dedup_checksum(spa);
2959 zio_pop_transforms(zio);
2960 zio->io_stage = ZIO_STAGE_OPEN;
2961 BP_ZERO(bp);
2962 } else {
2963 zp->zp_dedup = B_FALSE;
2964 BP_SET_DEDUP(bp, B_FALSE);
2965 }
2966 ASSERT(!BP_GET_DEDUP(bp));
2967 zio->io_pipeline = ZIO_WRITE_PIPELINE;
2968 ddt_exit(ddt);
2969 return (ZIO_PIPELINE_CONTINUE);
2970 }
2971
2972 ditto_copies = ddt_ditto_copies_needed(ddt, dde, ddp);
2973 ASSERT(ditto_copies < SPA_DVAS_PER_BP);
2974
2975 if (ditto_copies > ddt_ditto_copies_present(dde) &&
2976 dde->dde_lead_zio[DDT_PHYS_DITTO] == NULL) {
2977 zio_prop_t czp = *zp;
2978
2979 czp.zp_copies = ditto_copies;
2980
2981 /*
2982 * If we arrived here with an override bp, we won't have run
2983 * the transform stack, so we won't have the data we need to
2984 * generate a child i/o. So, toss the override bp and restart.
2985 * This is safe, because using the override bp is just an
2986 * optimization; and it's rare, so the cost doesn't matter.
2987 */
2988 if (zio->io_bp_override) {
2989 zio_pop_transforms(zio);
2990 zio->io_stage = ZIO_STAGE_OPEN;
2991 zio->io_pipeline = ZIO_WRITE_PIPELINE;
2992 zio->io_bp_override = NULL;
2993 BP_ZERO(bp);
2994 ddt_exit(ddt);
2995 return (ZIO_PIPELINE_CONTINUE);
2996 }
2997
2998 dio = zio_write(zio, spa, txg, bp, zio->io_orig_abd,
2999 zio->io_orig_size, zio->io_orig_size, &czp, NULL, NULL,
3000 NULL, zio_ddt_ditto_write_done, dde, zio->io_priority,
3001 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark);
3002
3003 zio_push_transform(dio, zio->io_abd, zio->io_size, 0, NULL);
3004 dde->dde_lead_zio[DDT_PHYS_DITTO] = dio;
3005 }
3006
3007 if (ddp->ddp_phys_birth != 0 || dde->dde_lead_zio[p] != NULL) {
3008 if (ddp->ddp_phys_birth != 0)
3009 ddt_bp_fill(ddp, bp, txg);
3010 if (dde->dde_lead_zio[p] != NULL)
3011 zio_add_child(zio, dde->dde_lead_zio[p]);
3012 else
3013 ddt_phys_addref(ddp);
3014 } else if (zio->io_bp_override) {
3015 ASSERT(bp->blk_birth == txg);
3016 ASSERT(BP_EQUAL(bp, zio->io_bp_override));
3017 ddt_phys_fill(ddp, bp);
3018 ddt_phys_addref(ddp);
3019 } else {
3020 cio = zio_write(zio, spa, txg, bp, zio->io_orig_abd,
3021 zio->io_orig_size, zio->io_orig_size, zp,
3022 zio_ddt_child_write_ready, NULL, NULL,
3023 zio_ddt_child_write_done, dde, zio->io_priority,
3024 ZIO_DDT_CHILD_FLAGS(zio), &zio->io_bookmark);
3025
3026 zio_push_transform(cio, zio->io_abd, zio->io_size, 0, NULL);
3027 dde->dde_lead_zio[p] = cio;
3028 }
3029
3030 ddt_exit(ddt);
3031
3032 if (cio)
3033 zio_nowait(cio);
3034 if (dio)
3035 zio_nowait(dio);
3036
3037 return (ZIO_PIPELINE_CONTINUE);
3038 }
3039
3040 ddt_entry_t *freedde; /* for debugging */
3041
3042 static int
3043 zio_ddt_free(zio_t *zio)
3044 {
3045 spa_t *spa = zio->io_spa;
3046 blkptr_t *bp = zio->io_bp;
3047 ddt_t *ddt = ddt_select(spa, bp);
3048 ddt_entry_t *dde;
3049 ddt_phys_t *ddp;
3050
3051 ASSERT(BP_GET_DEDUP(bp));
3052 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
3053
3054 ddt_enter(ddt);
3055 freedde = dde = ddt_lookup(ddt, bp, B_TRUE);
3056 ddp = ddt_phys_select(dde, bp);
3057 ddt_phys_decref(ddp);
3058 ddt_exit(ddt);
3059
3060 return (ZIO_PIPELINE_CONTINUE);
3061 }
3062
3063 /*
3064 * ==========================================================================
3065 * Allocate and free blocks
3066 * ==========================================================================
3067 */
3068
3069 static zio_t *
3070 zio_io_to_allocate(spa_t *spa, int allocator)
3071 {
3072 zio_t *zio;
3073
3074 ASSERT(MUTEX_HELD(&spa->spa_alloc_locks[allocator]));
3075
3076 zio = avl_first(&spa->spa_alloc_trees[allocator]);
3077 if (zio == NULL)
3078 return (NULL);
3079
3080 ASSERT(IO_IS_ALLOCATING(zio));
3081
3082 /*
3083 * Try to place a reservation for this zio. If we're unable to
3084 * reserve then we throttle.
3085 */
3086 ASSERT3U(zio->io_allocator, ==, allocator);
3087 if (!metaslab_class_throttle_reserve(zio->io_metaslab_class,
3088 zio->io_prop.zp_copies, zio->io_allocator, zio, 0)) {
3089 return (NULL);
3090 }
3091
3092 avl_remove(&spa->spa_alloc_trees[allocator], zio);
3093 ASSERT3U(zio->io_stage, <, ZIO_STAGE_DVA_ALLOCATE);
3094
3095 return (zio);
3096 }
3097
3098 static int
3099 zio_dva_throttle(zio_t *zio)
3100 {
3101 spa_t *spa = zio->io_spa;
3102 zio_t *nio;
3103 metaslab_class_t *mc;
3104
3105 /* locate an appropriate allocation class */
3106 mc = spa_preferred_class(spa, zio->io_size, zio->io_prop.zp_type,
3107 zio->io_prop.zp_level, zio->io_prop.zp_zpl_smallblk);
3108
3109 if (zio->io_priority == ZIO_PRIORITY_SYNC_WRITE ||
3110 !mc->mc_alloc_throttle_enabled ||
3111 zio->io_child_type == ZIO_CHILD_GANG ||
3112 zio->io_flags & ZIO_FLAG_NODATA) {
3113 return (ZIO_PIPELINE_CONTINUE);
3114 }
3115
3116 ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
3117
3118 ASSERT3U(zio->io_queued_timestamp, >, 0);
3119 ASSERT(zio->io_stage == ZIO_STAGE_DVA_THROTTLE);
3120
3121 zbookmark_phys_t *bm = &zio->io_bookmark;
3122 /*
3123 * We want to try to use as many allocators as possible to help improve
3124 * performance, but we also want logically adjacent IOs to be physically
3125 * adjacent to improve sequential read performance. We chunk each object
3126 * into 2^20 block regions, and then hash based on the objset, object,
3127 * level, and region to accomplish both of these goals.
3128 */
3129 zio->io_allocator = cityhash4(bm->zb_objset, bm->zb_object,
3130 bm->zb_level, bm->zb_blkid >> 20) % spa->spa_alloc_count;
3131 mutex_enter(&spa->spa_alloc_locks[zio->io_allocator]);
3132 ASSERT(zio->io_type == ZIO_TYPE_WRITE);
3133 zio->io_metaslab_class = mc;
3134 avl_add(&spa->spa_alloc_trees[zio->io_allocator], zio);
3135 nio = zio_io_to_allocate(spa, zio->io_allocator);
3136 mutex_exit(&spa->spa_alloc_locks[zio->io_allocator]);
3137
3138 if (nio == zio)
3139 return (ZIO_PIPELINE_CONTINUE);
3140
3141 if (nio != NULL) {
3142 ASSERT(nio->io_stage == ZIO_STAGE_DVA_THROTTLE);
3143 /*
3144 * We are passing control to a new zio so make sure that
3145 * it is processed by a different thread. We do this to
3146 * avoid stack overflows that can occur when parents are
3147 * throttled and children are making progress. We allow
3148 * it to go to the head of the taskq since it's already
3149 * been waiting.
3150 */
3151 zio_taskq_dispatch(nio, ZIO_TASKQ_ISSUE, B_TRUE);
3152 }
3153 return (ZIO_PIPELINE_STOP);
3154 }
3155
3156 static void
3157 zio_allocate_dispatch(spa_t *spa, int allocator)
3158 {
3159 zio_t *zio;
3160
3161 mutex_enter(&spa->spa_alloc_locks[allocator]);
3162 zio = zio_io_to_allocate(spa, allocator);
3163 mutex_exit(&spa->spa_alloc_locks[allocator]);
3164 if (zio == NULL)
3165 return;
3166
3167 ASSERT3U(zio->io_stage, ==, ZIO_STAGE_DVA_THROTTLE);
3168 ASSERT0(zio->io_error);
3169 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE, B_TRUE);
3170 }
3171
3172 static int
3173 zio_dva_allocate(zio_t *zio)
3174 {
3175 spa_t *spa = zio->io_spa;
3176 metaslab_class_t *mc;
3177 blkptr_t *bp = zio->io_bp;
3178 int error;
3179 int flags = 0;
3180
3181 if (zio->io_gang_leader == NULL) {
3182 ASSERT(zio->io_child_type > ZIO_CHILD_GANG);
3183 zio->io_gang_leader = zio;
3184 }
3185
3186 ASSERT(BP_IS_HOLE(bp));
3187 ASSERT0(BP_GET_NDVAS(bp));
3188 ASSERT3U(zio->io_prop.zp_copies, >, 0);
3189 ASSERT3U(zio->io_prop.zp_copies, <=, spa_max_replication(spa));
3190 ASSERT3U(zio->io_size, ==, BP_GET_PSIZE(bp));
3191
3192 if (zio->io_flags & ZIO_FLAG_NODATA)
3193 flags |= METASLAB_DONT_THROTTLE;
3194 if (zio->io_flags & ZIO_FLAG_GANG_CHILD)
3195 flags |= METASLAB_GANG_CHILD;
3196 if (zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE)
3197 flags |= METASLAB_ASYNC_ALLOC;
3198
3199 /*
3200 * if not already chosen, locate an appropriate allocation class
3201 */
3202 mc = zio->io_metaslab_class;
3203 if (mc == NULL) {
3204 mc = spa_preferred_class(spa, zio->io_size,
3205 zio->io_prop.zp_type, zio->io_prop.zp_level,
3206 zio->io_prop.zp_zpl_smallblk);
3207 zio->io_metaslab_class = mc;
3208 }
3209
3210 error = metaslab_alloc(spa, mc, zio->io_size, bp,
3211 zio->io_prop.zp_copies, zio->io_txg, NULL, flags,
3212 &zio->io_alloc_list, zio, zio->io_allocator);
3213
3214 /*
3215 * Fallback to normal class when an alloc class is full
3216 */
3217 if (error == ENOSPC && mc != spa_normal_class(spa)) {
3218 /*
3219 * If throttling, transfer reservation over to normal class.
3220 * The io_allocator slot can remain the same even though we
3221 * are switching classes.
3222 */
3223 if (mc->mc_alloc_throttle_enabled &&
3224 (zio->io_flags & ZIO_FLAG_IO_ALLOCATING)) {
3225 metaslab_class_throttle_unreserve(mc,
3226 zio->io_prop.zp_copies, zio->io_allocator, zio);
3227 zio->io_flags &= ~ZIO_FLAG_IO_ALLOCATING;
3228
3229 mc = spa_normal_class(spa);
3230 VERIFY(metaslab_class_throttle_reserve(mc,
3231 zio->io_prop.zp_copies, zio->io_allocator, zio,
3232 flags | METASLAB_MUST_RESERVE));
3233 } else {
3234 mc = spa_normal_class(spa);
3235 }
3236 zio->io_metaslab_class = mc;
3237
3238 error = metaslab_alloc(spa, mc, zio->io_size, bp,
3239 zio->io_prop.zp_copies, zio->io_txg, NULL, flags,
3240 &zio->io_alloc_list, zio, zio->io_allocator);
3241 }
3242
3243 if (error != 0) {
3244 zfs_dbgmsg("%s: metaslab allocation failure: zio %p, "
3245 "size %llu, error %d", spa_name(spa), zio, zio->io_size,
3246 error);
3247 if (error == ENOSPC && zio->io_size > SPA_MINBLOCKSIZE)
3248 return (zio_write_gang_block(zio));
3249 zio->io_error = error;
3250 }
3251
3252 return (ZIO_PIPELINE_CONTINUE);
3253 }
3254
3255 static int
3256 zio_dva_free(zio_t *zio)
3257 {
3258 metaslab_free(zio->io_spa, zio->io_bp, zio->io_txg, B_FALSE);
3259
3260 return (ZIO_PIPELINE_CONTINUE);
3261 }
3262
3263 static int
3264 zio_dva_claim(zio_t *zio)
3265 {
3266 int error;
3267
3268 error = metaslab_claim(zio->io_spa, zio->io_bp, zio->io_txg);
3269 if (error)
3270 zio->io_error = error;
3271
3272 return (ZIO_PIPELINE_CONTINUE);
3273 }
3274
3275 /*
3276 * Undo an allocation. This is used by zio_done() when an I/O fails
3277 * and we want to give back the block we just allocated.
3278 * This handles both normal blocks and gang blocks.
3279 */
3280 static void
3281 zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp)
3282 {
3283 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp));
3284 ASSERT(zio->io_bp_override == NULL);
3285
3286 if (!BP_IS_HOLE(bp))
3287 metaslab_free(zio->io_spa, bp, bp->blk_birth, B_TRUE);
3288
3289 if (gn != NULL) {
3290 for (int g = 0; g < SPA_GBH_NBLKPTRS; g++) {
3291 zio_dva_unallocate(zio, gn->gn_child[g],
3292 &gn->gn_gbh->zg_blkptr[g]);
3293 }
3294 }
3295 }
3296
3297 /*
3298 * Try to allocate an intent log block. Return 0 on success, errno on failure.
3299 */
3300 int
3301 zio_alloc_zil(spa_t *spa, objset_t *os, uint64_t txg, blkptr_t *new_bp,
3302 blkptr_t *old_bp, uint64_t size, boolean_t *slog)
3303 {
3304 int error = 1;
3305 zio_alloc_list_t io_alloc_list;
3306
3307 ASSERT(txg > spa_syncing_txg(spa));
3308
3309 metaslab_trace_init(&io_alloc_list);
3310
3311 /*
3312 * Block pointer fields are useful to metaslabs for stats and debugging.
3313 * Fill in the obvious ones before calling into metaslab_alloc().
3314 */
3315 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG);
3316 BP_SET_PSIZE(new_bp, size);
3317 BP_SET_LEVEL(new_bp, 0);
3318
3319 /*
3320 * When allocating a zil block, we don't have information about
3321 * the final destination of the block except the objset it's part
3322 * of, so we just hash the objset ID to pick the allocator to get
3323 * some parallelism.
3324 */
3325 error = metaslab_alloc(spa, spa_log_class(spa), size, new_bp, 1,
3326 txg, old_bp, METASLAB_HINTBP_AVOID, &io_alloc_list, NULL,
3327 cityhash4(0, 0, 0,
3328 os->os_dsl_dataset->ds_object) % spa->spa_alloc_count);
3329 if (error == 0) {
3330 *slog = TRUE;
3331 } else {
3332 error = metaslab_alloc(spa, spa_normal_class(spa), size,
3333 new_bp, 1, txg, old_bp, METASLAB_HINTBP_AVOID,
3334 &io_alloc_list, NULL, cityhash4(0, 0, 0,
3335 os->os_dsl_dataset->ds_object) % spa->spa_alloc_count);
3336 if (error == 0)
3337 *slog = FALSE;
3338 }
3339 metaslab_trace_fini(&io_alloc_list);
3340
3341 if (error == 0) {
3342 BP_SET_LSIZE(new_bp, size);
3343 BP_SET_PSIZE(new_bp, size);
3344 BP_SET_COMPRESS(new_bp, ZIO_COMPRESS_OFF);
3345 BP_SET_CHECKSUM(new_bp,
3346 spa_version(spa) >= SPA_VERSION_SLIM_ZIL
3347 ? ZIO_CHECKSUM_ZILOG2 : ZIO_CHECKSUM_ZILOG);
3348 BP_SET_TYPE(new_bp, DMU_OT_INTENT_LOG);
3349 BP_SET_LEVEL(new_bp, 0);
3350 BP_SET_DEDUP(new_bp, 0);
3351 BP_SET_BYTEORDER(new_bp, ZFS_HOST_BYTEORDER);
3352
3353 /*
3354 * encrypted blocks will require an IV and salt. We generate
3355 * these now since we will not be rewriting the bp at
3356 * rewrite time.
3357 */
3358 if (os->os_encrypted) {
3359 uint8_t iv[ZIO_DATA_IV_LEN];
3360 uint8_t salt[ZIO_DATA_SALT_LEN];
3361
3362 BP_SET_CRYPT(new_bp, B_TRUE);
3363 VERIFY0(spa_crypt_get_salt(spa,
3364 dmu_objset_id(os), salt));
3365 VERIFY0(zio_crypt_generate_iv(iv));
3366
3367 zio_crypt_encode_params_bp(new_bp, salt, iv);
3368 }
3369 } else {
3370 zfs_dbgmsg("%s: zil block allocation failure: "
3371 "size %llu, error %d", spa_name(spa), size, error);
3372 }
3373
3374 return (error);
3375 }
3376
3377 /*
3378 * ==========================================================================
3379 * Read and write to physical devices
3380 * ==========================================================================
3381 */
3382
3383 /*
3384 * Issue an I/O to the underlying vdev. Typically the issue pipeline
3385 * stops after this stage and will resume upon I/O completion.
3386 * However, there are instances where the vdev layer may need to
3387 * continue the pipeline when an I/O was not issued. Since the I/O
3388 * that was sent to the vdev layer might be different than the one
3389 * currently active in the pipeline (see vdev_queue_io()), we explicitly
3390 * force the underlying vdev layers to call either zio_execute() or
3391 * zio_interrupt() to ensure that the pipeline continues with the correct I/O.
3392 */
3393 static int
3394 zio_vdev_io_start(zio_t *zio)
3395 {
3396 vdev_t *vd = zio->io_vd;
3397 uint64_t align;
3398 spa_t *spa = zio->io_spa;
3399
3400 zio->io_delay = 0;
3401
3402 ASSERT(zio->io_error == 0);
3403 ASSERT(zio->io_child_error[ZIO_CHILD_VDEV] == 0);
3404
3405 if (vd == NULL) {
3406 if (!(zio->io_flags & ZIO_FLAG_CONFIG_WRITER))
3407 spa_config_enter(spa, SCL_ZIO, zio, RW_READER);
3408
3409 /*
3410 * The mirror_ops handle multiple DVAs in a single BP.
3411 */
3412 vdev_mirror_ops.vdev_op_io_start(zio);
3413 return (ZIO_PIPELINE_STOP);
3414 }
3415
3416 ASSERT3P(zio->io_logical, !=, zio);
3417 if (zio->io_type == ZIO_TYPE_WRITE) {
3418 ASSERT(spa->spa_trust_config);
3419
3420 /*
3421 * Note: the code can handle other kinds of writes,
3422 * but we don't expect them.
3423 */
3424 if (zio->io_vd->vdev_removing) {
3425 ASSERT(zio->io_flags &
3426 (ZIO_FLAG_PHYSICAL | ZIO_FLAG_SELF_HEAL |
3427 ZIO_FLAG_RESILVER | ZIO_FLAG_INDUCE_DAMAGE));
3428 }
3429 }
3430
3431 align = 1ULL << vd->vdev_top->vdev_ashift;
3432
3433 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL) &&
3434 P2PHASE(zio->io_size, align) != 0) {
3435 /* Transform logical writes to be a full physical block size. */
3436 uint64_t asize = P2ROUNDUP(zio->io_size, align);
3437 abd_t *abuf = abd_alloc_sametype(zio->io_abd, asize);
3438 ASSERT(vd == vd->vdev_top);
3439 if (zio->io_type == ZIO_TYPE_WRITE) {
3440 abd_copy(abuf, zio->io_abd, zio->io_size);
3441 abd_zero_off(abuf, zio->io_size, asize - zio->io_size);
3442 }
3443 zio_push_transform(zio, abuf, asize, asize, zio_subblock);
3444 }
3445
3446 /*
3447 * If this is not a physical io, make sure that it is properly aligned
3448 * before proceeding.
3449 */
3450 if (!(zio->io_flags & ZIO_FLAG_PHYSICAL)) {
3451 ASSERT0(P2PHASE(zio->io_offset, align));
3452 ASSERT0(P2PHASE(zio->io_size, align));
3453 } else {
3454 /*
3455 * For physical writes, we allow 512b aligned writes and assume
3456 * the device will perform a read-modify-write as necessary.
3457 */
3458 ASSERT0(P2PHASE(zio->io_offset, SPA_MINBLOCKSIZE));
3459 ASSERT0(P2PHASE(zio->io_size, SPA_MINBLOCKSIZE));
3460 }
3461
3462 VERIFY(zio->io_type != ZIO_TYPE_WRITE || spa_writeable(spa));
3463
3464 /*
3465 * If this is a repair I/O, and there's no self-healing involved --
3466 * that is, we're just resilvering what we expect to resilver --
3467 * then don't do the I/O unless zio's txg is actually in vd's DTL.
3468 * This prevents spurious resilvering.
3469 *
3470 * There are a few ways that we can end up creating these spurious
3471 * resilver i/os:
3472 *
3473 * 1. A resilver i/o will be issued if any DVA in the BP has a
3474 * dirty DTL. The mirror code will issue resilver writes to
3475 * each DVA, including the one(s) that are not on vdevs with dirty
3476 * DTLs.
3477 *
3478 * 2. With nested replication, which happens when we have a
3479 * "replacing" or "spare" vdev that's a child of a mirror or raidz.
3480 * For example, given mirror(replacing(A+B), C), it's likely that
3481 * only A is out of date (it's the new device). In this case, we'll
3482 * read from C, then use the data to resilver A+B -- but we don't
3483 * actually want to resilver B, just A. The top-level mirror has no
3484 * way to know this, so instead we just discard unnecessary repairs
3485 * as we work our way down the vdev tree.
3486 *
3487 * 3. ZTEST also creates mirrors of mirrors, mirrors of raidz, etc.
3488 * The same logic applies to any form of nested replication: ditto
3489 * + mirror, RAID-Z + replacing, etc.
3490 *
3491 * However, indirect vdevs point off to other vdevs which may have
3492 * DTL's, so we never bypass them. The child i/os on concrete vdevs
3493 * will be properly bypassed instead.
3494 */
3495 if ((zio->io_flags & ZIO_FLAG_IO_REPAIR) &&
3496 !(zio->io_flags & ZIO_FLAG_SELF_HEAL) &&
3497 zio->io_txg != 0 && /* not a delegated i/o */
3498 vd->vdev_ops != &vdev_indirect_ops &&
3499 !vdev_dtl_contains(vd, DTL_PARTIAL, zio->io_txg, 1)) {
3500 ASSERT(zio->io_type == ZIO_TYPE_WRITE);
3501 zio_vdev_io_bypass(zio);
3502 return (ZIO_PIPELINE_CONTINUE);
3503 }
3504
3505 if (vd->vdev_ops->vdev_op_leaf && (zio->io_type == ZIO_TYPE_READ ||
3506 zio->io_type == ZIO_TYPE_WRITE || zio->io_type == ZIO_TYPE_TRIM)) {
3507
3508 if (zio->io_type == ZIO_TYPE_READ && vdev_cache_read(zio))
3509 return (ZIO_PIPELINE_CONTINUE);
3510
3511 if ((zio = vdev_queue_io(zio)) == NULL)
3512 return (ZIO_PIPELINE_STOP);
3513
3514 if (!vdev_accessible(vd, zio)) {
3515 zio->io_error = SET_ERROR(ENXIO);
3516 zio_interrupt(zio);
3517 return (ZIO_PIPELINE_STOP);
3518 }
3519 zio->io_delay = gethrtime();
3520 }
3521
3522 vd->vdev_ops->vdev_op_io_start(zio);
3523 return (ZIO_PIPELINE_STOP);
3524 }
3525
3526 static int
3527 zio_vdev_io_done(zio_t *zio)
3528 {
3529 vdev_t *vd = zio->io_vd;
3530 vdev_ops_t *ops = vd ? vd->vdev_ops : &vdev_mirror_ops;
3531 boolean_t unexpected_error = B_FALSE;
3532
3533 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV_BIT, ZIO_WAIT_DONE)) {
3534 return (ZIO_PIPELINE_STOP);
3535 }
3536
3537 ASSERT(zio->io_type == ZIO_TYPE_READ ||
3538 zio->io_type == ZIO_TYPE_WRITE || zio->io_type == ZIO_TYPE_TRIM);
3539
3540 if (zio->io_delay)
3541 zio->io_delay = gethrtime() - zio->io_delay;
3542
3543 if (vd != NULL && vd->vdev_ops->vdev_op_leaf) {
3544
3545 vdev_queue_io_done(zio);
3546
3547 if (zio->io_type == ZIO_TYPE_WRITE)
3548 vdev_cache_write(zio);
3549
3550 if (zio_injection_enabled && zio->io_error == 0)
3551 zio->io_error = zio_handle_device_injection(vd,
3552 zio, EIO);
3553
3554 if (zio_injection_enabled && zio->io_error == 0)
3555 zio->io_error = zio_handle_label_injection(zio, EIO);
3556
3557 if (zio->io_error && zio->io_type != ZIO_TYPE_TRIM) {
3558 if (!vdev_accessible(vd, zio)) {
3559 zio->io_error = SET_ERROR(ENXIO);
3560 } else {
3561 unexpected_error = B_TRUE;
3562 }
3563 }
3564 }
3565
3566 ops->vdev_op_io_done(zio);
3567
3568 if (unexpected_error)
3569 VERIFY(vdev_probe(vd, zio) == NULL);
3570
3571 return (ZIO_PIPELINE_CONTINUE);
3572 }
3573
3574 /*
3575 * This function is used to change the priority of an existing zio that is
3576 * currently in-flight. This is used by the arc to upgrade priority in the
3577 * event that a demand read is made for a block that is currently queued
3578 * as a scrub or async read IO. Otherwise, the high priority read request
3579 * would end up having to wait for the lower priority IO.
3580 */
3581 void
3582 zio_change_priority(zio_t *pio, zio_priority_t priority)
3583 {
3584 zio_t *cio, *cio_next;
3585 zio_link_t *zl = NULL;
3586
3587 ASSERT3U(priority, <, ZIO_PRIORITY_NUM_QUEUEABLE);
3588
3589 if (pio->io_vd != NULL && pio->io_vd->vdev_ops->vdev_op_leaf) {
3590 vdev_queue_change_io_priority(pio, priority);
3591 } else {
3592 pio->io_priority = priority;
3593 }
3594
3595 mutex_enter(&pio->io_lock);
3596 for (cio = zio_walk_children(pio, &zl); cio != NULL; cio = cio_next) {
3597 cio_next = zio_walk_children(pio, &zl);
3598 zio_change_priority(cio, priority);
3599 }
3600 mutex_exit(&pio->io_lock);
3601 }
3602
3603 /*
3604 * For non-raidz ZIOs, we can just copy aside the bad data read from the
3605 * disk, and use that to finish the checksum ereport later.
3606 */
3607 static void
3608 zio_vsd_default_cksum_finish(zio_cksum_report_t *zcr,
3609 const abd_t *good_buf)
3610 {
3611 /* no processing needed */
3612 zfs_ereport_finish_checksum(zcr, good_buf, zcr->zcr_cbdata, B_FALSE);
3613 }
3614
3615 /*ARGSUSED*/
3616 void
3617 zio_vsd_default_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *ignored)
3618 {
3619 void *abd = abd_alloc_sametype(zio->io_abd, zio->io_size);
3620
3621 abd_copy(abd, zio->io_abd, zio->io_size);
3622
3623 zcr->zcr_cbinfo = zio->io_size;
3624 zcr->zcr_cbdata = abd;
3625 zcr->zcr_finish = zio_vsd_default_cksum_finish;
3626 zcr->zcr_free = zio_abd_free;
3627 }
3628
3629 static int
3630 zio_vdev_io_assess(zio_t *zio)
3631 {
3632 vdev_t *vd = zio->io_vd;
3633
3634 if (zio_wait_for_children(zio, ZIO_CHILD_VDEV_BIT, ZIO_WAIT_DONE)) {
3635 return (ZIO_PIPELINE_STOP);
3636 }
3637
3638 if (vd == NULL && !(zio->io_flags & ZIO_FLAG_CONFIG_WRITER))
3639 spa_config_exit(zio->io_spa, SCL_ZIO, zio);
3640
3641 if (zio->io_vsd != NULL) {
3642 zio->io_vsd_ops->vsd_free(zio);
3643 zio->io_vsd = NULL;
3644 }
3645
3646 if (zio_injection_enabled && zio->io_error == 0)
3647 zio->io_error = zio_handle_fault_injection(zio, EIO);
3648
3649 /*
3650 * If the I/O failed, determine whether we should attempt to retry it.
3651 *
3652 * On retry, we cut in line in the issue queue, since we don't want
3653 * compression/checksumming/etc. work to prevent our (cheap) IO reissue.
3654 */
3655 if (zio->io_error && vd == NULL &&
3656 !(zio->io_flags & (ZIO_FLAG_DONT_RETRY | ZIO_FLAG_IO_RETRY))) {
3657 ASSERT(!(zio->io_flags & ZIO_FLAG_DONT_QUEUE)); /* not a leaf */
3658 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_BYPASS)); /* not a leaf */
3659 zio->io_error = 0;
3660 zio->io_flags |= ZIO_FLAG_IO_RETRY |
3661 ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_AGGREGATE;
3662 zio->io_stage = ZIO_STAGE_VDEV_IO_START >> 1;
3663 zio_taskq_dispatch(zio, ZIO_TASKQ_ISSUE,
3664 zio_requeue_io_start_cut_in_line);
3665 return (ZIO_PIPELINE_STOP);
3666 }
3667
3668 /*
3669 * If we got an error on a leaf device, convert it to ENXIO
3670 * if the device is not accessible at all.
3671 */
3672 if (zio->io_error && vd != NULL && vd->vdev_ops->vdev_op_leaf &&
3673 !vdev_accessible(vd, zio))
3674 zio->io_error = SET_ERROR(ENXIO);
3675
3676 /*
3677 * If we can't write to an interior vdev (mirror or RAID-Z),
3678 * set vdev_cant_write so that we stop trying to allocate from it.
3679 */
3680 if (zio->io_error == ENXIO && zio->io_type == ZIO_TYPE_WRITE &&
3681 vd != NULL && !vd->vdev_ops->vdev_op_leaf) {
3682 vd->vdev_cant_write = B_TRUE;
3683 }
3684
3685 /*
3686 * If a cache flush returns ENOTSUP or ENOTTY, we know that no future
3687 * attempts will ever succeed. In this case we set a persistent
3688 * boolean flag so that we don't bother with it in the future.
3689 */
3690 if ((zio->io_error == ENOTSUP || zio->io_error == ENOTTY) &&
3691 zio->io_type == ZIO_TYPE_IOCTL &&
3692 zio->io_cmd == DKIOCFLUSHWRITECACHE && vd != NULL)
3693 vd->vdev_nowritecache = B_TRUE;
3694
3695 if (zio->io_error)
3696 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
3697
3698 if (vd != NULL && vd->vdev_ops->vdev_op_leaf &&
3699 zio->io_physdone != NULL) {
3700 ASSERT(!(zio->io_flags & ZIO_FLAG_DELEGATED));
3701 ASSERT(zio->io_child_type == ZIO_CHILD_VDEV);
3702 zio->io_physdone(zio->io_logical);
3703 }
3704
3705 return (ZIO_PIPELINE_CONTINUE);
3706 }
3707
3708 void
3709 zio_vdev_io_reissue(zio_t *zio)
3710 {
3711 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START);
3712 ASSERT(zio->io_error == 0);
3713
3714 zio->io_stage >>= 1;
3715 }
3716
3717 void
3718 zio_vdev_io_redone(zio_t *zio)
3719 {
3720 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_DONE);
3721
3722 zio->io_stage >>= 1;
3723 }
3724
3725 void
3726 zio_vdev_io_bypass(zio_t *zio)
3727 {
3728 ASSERT(zio->io_stage == ZIO_STAGE_VDEV_IO_START);
3729 ASSERT(zio->io_error == 0);
3730
3731 zio->io_flags |= ZIO_FLAG_IO_BYPASS;
3732 zio->io_stage = ZIO_STAGE_VDEV_IO_ASSESS >> 1;
3733 }
3734
3735 /*
3736 * ==========================================================================
3737 * Encrypt and store encryption parameters
3738 * ==========================================================================
3739 */
3740
3741
3742 /*
3743 * This function is used for ZIO_STAGE_ENCRYPT. It is responsible for
3744 * managing the storage of encryption parameters and passing them to the
3745 * lower-level encryption functions.
3746 */
3747 static int
3748 zio_encrypt(zio_t *zio)
3749 {
3750 zio_prop_t *zp = &zio->io_prop;
3751 spa_t *spa = zio->io_spa;
3752 blkptr_t *bp = zio->io_bp;
3753 uint64_t psize = BP_GET_PSIZE(bp);
3754 uint64_t dsobj = zio->io_bookmark.zb_objset;
3755 dmu_object_type_t ot = BP_GET_TYPE(bp);
3756 void *enc_buf = NULL;
3757 abd_t *eabd = NULL;
3758 uint8_t salt[ZIO_DATA_SALT_LEN];
3759 uint8_t iv[ZIO_DATA_IV_LEN];
3760 uint8_t mac[ZIO_DATA_MAC_LEN];
3761 boolean_t no_crypt = B_FALSE;
3762
3763 /* the root zio already encrypted the data */
3764 if (zio->io_child_type == ZIO_CHILD_GANG)
3765 return (ZIO_PIPELINE_CONTINUE);
3766
3767 /* only ZIL blocks are re-encrypted on rewrite */
3768 if (!IO_IS_ALLOCATING(zio) && ot != DMU_OT_INTENT_LOG)
3769 return (ZIO_PIPELINE_CONTINUE);
3770
3771 if (!(zp->zp_encrypt || BP_IS_ENCRYPTED(bp))) {
3772 BP_SET_CRYPT(bp, B_FALSE);
3773 return (ZIO_PIPELINE_CONTINUE);
3774 }
3775
3776 /* if we are doing raw encryption set the provided encryption params */
3777 if (zio->io_flags & ZIO_FLAG_RAW_ENCRYPT) {
3778 ASSERT0(BP_GET_LEVEL(bp));
3779 BP_SET_CRYPT(bp, B_TRUE);
3780 BP_SET_BYTEORDER(bp, zp->zp_byteorder);
3781 if (ot != DMU_OT_OBJSET)
3782 zio_crypt_encode_mac_bp(bp, zp->zp_mac);
3783
3784 /* dnode blocks must be written out in the provided byteorder */
3785 if (zp->zp_byteorder != ZFS_HOST_BYTEORDER &&
3786 ot == DMU_OT_DNODE) {
3787 void *bswap_buf = zio_buf_alloc(psize);
3788 abd_t *babd = abd_get_from_buf(bswap_buf, psize);
3789
3790 ASSERT3U(BP_GET_COMPRESS(bp), ==, ZIO_COMPRESS_OFF);
3791 abd_copy_to_buf(bswap_buf, zio->io_abd, psize);
3792 dmu_ot_byteswap[DMU_OT_BYTESWAP(ot)].ob_func(bswap_buf,
3793 psize);
3794
3795 abd_take_ownership_of_buf(babd, B_TRUE);
3796 zio_push_transform(zio, babd, psize, psize, NULL);
3797 }
3798
3799 if (DMU_OT_IS_ENCRYPTED(ot))
3800 zio_crypt_encode_params_bp(bp, zp->zp_salt, zp->zp_iv);
3801 return (ZIO_PIPELINE_CONTINUE);
3802 }
3803
3804 /* indirect blocks only maintain a cksum of the lower level MACs */
3805 if (BP_GET_LEVEL(bp) > 0) {
3806 BP_SET_CRYPT(bp, B_TRUE);
3807 VERIFY0(zio_crypt_do_indirect_mac_checksum_abd(B_TRUE,
3808 zio->io_orig_abd, BP_GET_LSIZE(bp), BP_SHOULD_BYTESWAP(bp),
3809 mac));
3810 zio_crypt_encode_mac_bp(bp, mac);
3811 return (ZIO_PIPELINE_CONTINUE);
3812 }
3813
3814 /*
3815 * Objset blocks are a special case since they have 2 256-bit MACs
3816 * embedded within them.
3817 */
3818 if (ot == DMU_OT_OBJSET) {
3819 ASSERT0(DMU_OT_IS_ENCRYPTED(ot));
3820 ASSERT3U(BP_GET_COMPRESS(bp), ==, ZIO_COMPRESS_OFF);
3821 BP_SET_CRYPT(bp, B_TRUE);
3822 VERIFY0(spa_do_crypt_objset_mac_abd(B_TRUE, spa, dsobj,
3823 zio->io_abd, psize, BP_SHOULD_BYTESWAP(bp)));
3824 return (ZIO_PIPELINE_CONTINUE);
3825 }
3826
3827 /* unencrypted object types are only authenticated with a MAC */
3828 if (!DMU_OT_IS_ENCRYPTED(ot)) {
3829 BP_SET_CRYPT(bp, B_TRUE);
3830 VERIFY0(spa_do_crypt_mac_abd(B_TRUE, spa, dsobj,
3831 zio->io_abd, psize, mac));
3832 zio_crypt_encode_mac_bp(bp, mac);
3833 return (ZIO_PIPELINE_CONTINUE);
3834 }
3835
3836 /*
3837 * Later passes of sync-to-convergence may decide to rewrite data
3838 * in place to avoid more disk reallocations. This presents a problem
3839 * for encryption because this consitutes rewriting the new data with
3840 * the same encryption key and IV. However, this only applies to blocks
3841 * in the MOS (particularly the spacemaps) and we do not encrypt the
3842 * MOS. We assert that the zio is allocating or an intent log write
3843 * to enforce this.
3844 */
3845 ASSERT(IO_IS_ALLOCATING(zio) || ot == DMU_OT_INTENT_LOG);
3846 ASSERT(BP_GET_LEVEL(bp) == 0 || ot == DMU_OT_INTENT_LOG);
3847 ASSERT(spa_feature_is_active(spa, SPA_FEATURE_ENCRYPTION));
3848 ASSERT3U(psize, !=, 0);
3849
3850 enc_buf = zio_buf_alloc(psize);
3851 eabd = abd_get_from_buf(enc_buf, psize);
3852 abd_take_ownership_of_buf(eabd, B_TRUE);
3853
3854 /*
3855 * For an explanation of what encryption parameters are stored
3856 * where, see the block comment in zio_crypt.c.
3857 */
3858 if (ot == DMU_OT_INTENT_LOG) {
3859 zio_crypt_decode_params_bp(bp, salt, iv);
3860 } else {
3861 BP_SET_CRYPT(bp, B_TRUE);
3862 }
3863
3864 /* Perform the encryption. This should not fail */
3865 VERIFY0(spa_do_crypt_abd(B_TRUE, spa, &zio->io_bookmark,
3866 BP_GET_TYPE(bp), BP_GET_DEDUP(bp), BP_SHOULD_BYTESWAP(bp),
3867 salt, iv, mac, psize, zio->io_abd, eabd, &no_crypt));
3868
3869 /* encode encryption metadata into the bp */
3870 if (ot == DMU_OT_INTENT_LOG) {
3871 /*
3872 * ZIL blocks store the MAC in the embedded checksum, so the
3873 * transform must always be applied.
3874 */
3875 zio_crypt_encode_mac_zil(enc_buf, mac);
3876 zio_push_transform(zio, eabd, psize, psize, NULL);
3877 } else {
3878 BP_SET_CRYPT(bp, B_TRUE);
3879 zio_crypt_encode_params_bp(bp, salt, iv);
3880 zio_crypt_encode_mac_bp(bp, mac);
3881
3882 if (no_crypt) {
3883 ASSERT3U(ot, ==, DMU_OT_DNODE);
3884 abd_free(eabd);
3885 } else {
3886 zio_push_transform(zio, eabd, psize, psize, NULL);
3887 }
3888 }
3889
3890 return (ZIO_PIPELINE_CONTINUE);
3891 }
3892
3893 /*
3894 * ==========================================================================
3895 * Generate and verify checksums
3896 * ==========================================================================
3897 */
3898 static int
3899 zio_checksum_generate(zio_t *zio)
3900 {
3901 blkptr_t *bp = zio->io_bp;
3902 enum zio_checksum checksum;
3903
3904 if (bp == NULL) {
3905 /*
3906 * This is zio_write_phys().
3907 * We're either generating a label checksum, or none at all.
3908 */
3909 checksum = zio->io_prop.zp_checksum;
3910
3911 if (checksum == ZIO_CHECKSUM_OFF)
3912 return (ZIO_PIPELINE_CONTINUE);
3913
3914 ASSERT(checksum == ZIO_CHECKSUM_LABEL);
3915 } else {
3916 if (BP_IS_GANG(bp) && zio->io_child_type == ZIO_CHILD_GANG) {
3917 ASSERT(!IO_IS_ALLOCATING(zio));
3918 checksum = ZIO_CHECKSUM_GANG_HEADER;
3919 } else {
3920 checksum = BP_GET_CHECKSUM(bp);
3921 }
3922 }
3923
3924 zio_checksum_compute(zio, checksum, zio->io_abd, zio->io_size);
3925
3926 return (ZIO_PIPELINE_CONTINUE);
3927 }
3928
3929 static int
3930 zio_checksum_verify(zio_t *zio)
3931 {
3932 zio_bad_cksum_t info;
3933 blkptr_t *bp = zio->io_bp;
3934 int error;
3935
3936 ASSERT(zio->io_vd != NULL);
3937
3938 if (bp == NULL) {
3939 /*
3940 * This is zio_read_phys().
3941 * We're either verifying a label checksum, or nothing at all.
3942 */
3943 if (zio->io_prop.zp_checksum == ZIO_CHECKSUM_OFF)
3944 return (ZIO_PIPELINE_CONTINUE);
3945
3946 ASSERT(zio->io_prop.zp_checksum == ZIO_CHECKSUM_LABEL);
3947 }
3948
3949 if ((error = zio_checksum_error(zio, &info)) != 0) {
3950 zio->io_error = error;
3951 if (error == ECKSUM &&
3952 !(zio->io_flags & ZIO_FLAG_SPECULATIVE)) {
3953 zfs_ereport_start_checksum(zio->io_spa,
3954 zio->io_vd, &zio->io_bookmark, zio,
3955 zio->io_offset, zio->io_size, NULL, &info);
3956 }
3957 }
3958
3959 return (ZIO_PIPELINE_CONTINUE);
3960 }
3961
3962 /*
3963 * Called by RAID-Z to ensure we don't compute the checksum twice.
3964 */
3965 void
3966 zio_checksum_verified(zio_t *zio)
3967 {
3968 zio->io_pipeline &= ~ZIO_STAGE_CHECKSUM_VERIFY;
3969 }
3970
3971 /*
3972 * ==========================================================================
3973 * Error rank. Error are ranked in the order 0, ENXIO, ECKSUM, EIO, other.
3974 * An error of 0 indicates success. ENXIO indicates whole-device failure,
3975 * which may be transient (e.g. unplugged) or permament. ECKSUM and EIO
3976 * indicate errors that are specific to one I/O, and most likely permanent.
3977 * Any other error is presumed to be worse because we weren't expecting it.
3978 * ==========================================================================
3979 */
3980 int
3981 zio_worst_error(int e1, int e2)
3982 {
3983 static int zio_error_rank[] = { 0, ENXIO, ECKSUM, EIO };
3984 int r1, r2;
3985
3986 for (r1 = 0; r1 < sizeof (zio_error_rank) / sizeof (int); r1++)
3987 if (e1 == zio_error_rank[r1])
3988 break;
3989
3990 for (r2 = 0; r2 < sizeof (zio_error_rank) / sizeof (int); r2++)
3991 if (e2 == zio_error_rank[r2])
3992 break;
3993
3994 return (r1 > r2 ? e1 : e2);
3995 }
3996
3997 /*
3998 * ==========================================================================
3999 * I/O completion
4000 * ==========================================================================
4001 */
4002 static int
4003 zio_ready(zio_t *zio)
4004 {
4005 blkptr_t *bp = zio->io_bp;
4006 zio_t *pio, *pio_next;
4007 zio_link_t *zl = NULL;
4008
4009 if (zio_wait_for_children(zio, ZIO_CHILD_GANG_BIT | ZIO_CHILD_DDT_BIT,
4010 ZIO_WAIT_READY)) {
4011 return (ZIO_PIPELINE_STOP);
4012 }
4013
4014 if (zio->io_ready) {
4015 ASSERT(IO_IS_ALLOCATING(zio));
4016 ASSERT(bp->blk_birth == zio->io_txg || BP_IS_HOLE(bp) ||
4017 (zio->io_flags & ZIO_FLAG_NOPWRITE));
4018 ASSERT(zio->io_children[ZIO_CHILD_GANG][ZIO_WAIT_READY] == 0);
4019
4020 zio->io_ready(zio);
4021 }
4022
4023 if (bp != NULL && bp != &zio->io_bp_copy)
4024 zio->io_bp_copy = *bp;
4025
4026 if (zio->io_error != 0) {
4027 zio->io_pipeline = ZIO_INTERLOCK_PIPELINE;
4028
4029 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING) {
4030 ASSERT(IO_IS_ALLOCATING(zio));
4031 ASSERT(zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE);
4032 ASSERT(zio->io_metaslab_class != NULL);
4033
4034 /*
4035 * We were unable to allocate anything, unreserve and
4036 * issue the next I/O to allocate.
4037 */
4038 metaslab_class_throttle_unreserve(
4039 zio->io_metaslab_class, zio->io_prop.zp_copies,
4040 zio->io_allocator, zio);
4041 zio_allocate_dispatch(zio->io_spa, zio->io_allocator);
4042 }
4043 }
4044
4045 mutex_enter(&zio->io_lock);
4046 zio->io_state[ZIO_WAIT_READY] = 1;
4047 pio = zio_walk_parents(zio, &zl);
4048 mutex_exit(&zio->io_lock);
4049
4050 /*
4051 * As we notify zio's parents, new parents could be added.
4052 * New parents go to the head of zio's io_parent_list, however,
4053 * so we will (correctly) not notify them. The remainder of zio's
4054 * io_parent_list, from 'pio_next' onward, cannot change because
4055 * all parents must wait for us to be done before they can be done.
4056 */
4057 for (; pio != NULL; pio = pio_next) {
4058 pio_next = zio_walk_parents(zio, &zl);
4059 zio_notify_parent(pio, zio, ZIO_WAIT_READY);
4060 }
4061
4062 if (zio->io_flags & ZIO_FLAG_NODATA) {
4063 if (BP_IS_GANG(bp)) {
4064 zio->io_flags &= ~ZIO_FLAG_NODATA;
4065 } else {
4066 ASSERT((uintptr_t)zio->io_abd < SPA_MAXBLOCKSIZE);
4067 zio->io_pipeline &= ~ZIO_VDEV_IO_STAGES;
4068 }
4069 }
4070
4071 if (zio_injection_enabled &&
4072 zio->io_spa->spa_syncing_txg == zio->io_txg)
4073 zio_handle_ignored_writes(zio);
4074
4075 return (ZIO_PIPELINE_CONTINUE);
4076 }
4077
4078 /*
4079 * Update the allocation throttle accounting.
4080 */
4081 static void
4082 zio_dva_throttle_done(zio_t *zio)
4083 {
4084 zio_t *lio = zio->io_logical;
4085 zio_t *pio = zio_unique_parent(zio);
4086 vdev_t *vd = zio->io_vd;
4087 int flags = METASLAB_ASYNC_ALLOC;
4088
4089 ASSERT3P(zio->io_bp, !=, NULL);
4090 ASSERT3U(zio->io_type, ==, ZIO_TYPE_WRITE);
4091 ASSERT3U(zio->io_priority, ==, ZIO_PRIORITY_ASYNC_WRITE);
4092 ASSERT3U(zio->io_child_type, ==, ZIO_CHILD_VDEV);
4093 ASSERT(vd != NULL);
4094 ASSERT3P(vd, ==, vd->vdev_top);
4095 ASSERT(!(zio->io_flags & (ZIO_FLAG_IO_REPAIR | ZIO_FLAG_IO_RETRY)));
4096 ASSERT(zio->io_flags & ZIO_FLAG_IO_ALLOCATING);
4097 ASSERT(!(lio->io_flags & ZIO_FLAG_IO_REWRITE));
4098 ASSERT(!(lio->io_orig_flags & ZIO_FLAG_NODATA));
4099
4100 /*
4101 * Parents of gang children can have two flavors -- ones that
4102 * allocated the gang header (will have ZIO_FLAG_IO_REWRITE set)
4103 * and ones that allocated the constituent blocks. The allocation
4104 * throttle needs to know the allocating parent zio so we must find
4105 * it here.
4106 */
4107 if (pio->io_child_type == ZIO_CHILD_GANG) {
4108 /*
4109 * If our parent is a rewrite gang child then our grandparent
4110 * would have been the one that performed the allocation.
4111 */
4112 if (pio->io_flags & ZIO_FLAG_IO_REWRITE)
4113 pio = zio_unique_parent(pio);
4114 flags |= METASLAB_GANG_CHILD;
4115 }
4116
4117 ASSERT(IO_IS_ALLOCATING(pio));
4118 ASSERT3P(zio, !=, zio->io_logical);
4119 ASSERT(zio->io_logical != NULL);
4120 ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REPAIR));
4121 ASSERT0(zio->io_flags & ZIO_FLAG_NOPWRITE);
4122 ASSERT(zio->io_metaslab_class != NULL);
4123
4124 mutex_enter(&pio->io_lock);
4125 metaslab_group_alloc_decrement(zio->io_spa, vd->vdev_id, pio, flags,
4126 pio->io_allocator, B_TRUE);
4127 mutex_exit(&pio->io_lock);
4128
4129 metaslab_class_throttle_unreserve(zio->io_metaslab_class, 1,
4130 pio->io_allocator, pio);
4131
4132 /*
4133 * Call into the pipeline to see if there is more work that
4134 * needs to be done. If there is work to be done it will be
4135 * dispatched to another taskq thread.
4136 */
4137 zio_allocate_dispatch(zio->io_spa, pio->io_allocator);
4138 }
4139
4140 static int
4141 zio_done(zio_t *zio)
4142 {
4143 spa_t *spa = zio->io_spa;
4144 zio_t *lio = zio->io_logical;
4145 blkptr_t *bp = zio->io_bp;
4146 vdev_t *vd = zio->io_vd;
4147 uint64_t psize = zio->io_size;
4148 zio_t *pio, *pio_next;
4149 zio_link_t *zl = NULL;
4150
4151 /*
4152 * If our children haven't all completed,
4153 * wait for them and then repeat this pipeline stage.
4154 */
4155 if (zio_wait_for_children(zio, ZIO_CHILD_ALL_BITS, ZIO_WAIT_DONE)) {
4156 return (ZIO_PIPELINE_STOP);
4157 }
4158
4159 /*
4160 * If the allocation throttle is enabled, then update the accounting.
4161 * We only track child I/Os that are part of an allocating async
4162 * write. We must do this since the allocation is performed
4163 * by the logical I/O but the actual write is done by child I/Os.
4164 */
4165 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING &&
4166 zio->io_child_type == ZIO_CHILD_VDEV) {
4167 ASSERT(zio->io_metaslab_class != NULL);
4168 ASSERT(zio->io_metaslab_class->mc_alloc_throttle_enabled);
4169 zio_dva_throttle_done(zio);
4170 }
4171
4172 /*
4173 * If the allocation throttle is enabled, verify that
4174 * we have decremented the refcounts for every I/O that was throttled.
4175 */
4176 if (zio->io_flags & ZIO_FLAG_IO_ALLOCATING) {
4177 ASSERT(zio->io_type == ZIO_TYPE_WRITE);
4178 ASSERT(zio->io_priority == ZIO_PRIORITY_ASYNC_WRITE);
4179 ASSERT(bp != NULL);
4180
4181 metaslab_group_alloc_verify(spa, zio->io_bp, zio,
4182 zio->io_allocator);
4183 VERIFY(zfs_refcount_not_held(
4184 &zio->io_metaslab_class->mc_alloc_slots[zio->io_allocator],
4185 zio));
4186 }
4187
4188 for (int c = 0; c < ZIO_CHILD_TYPES; c++)
4189 for (int w = 0; w < ZIO_WAIT_TYPES; w++)
4190 ASSERT(zio->io_children[c][w] == 0);
4191
4192 if (bp != NULL && !BP_IS_EMBEDDED(bp)) {
4193 ASSERT(bp->blk_pad[0] == 0);
4194 ASSERT(bp->blk_pad[1] == 0);
4195 ASSERT(bcmp(bp, &zio->io_bp_copy, sizeof (blkptr_t)) == 0 ||
4196 (bp == zio_unique_parent(zio)->io_bp));
4197 if (zio->io_type == ZIO_TYPE_WRITE && !BP_IS_HOLE(bp) &&
4198 zio->io_bp_override == NULL &&
4199 !(zio->io_flags & ZIO_FLAG_IO_REPAIR)) {
4200 ASSERT3U(zio->io_prop.zp_copies, <=, BP_GET_NDVAS(bp));
4201 ASSERT(BP_COUNT_GANG(bp) == 0 ||
4202 (BP_COUNT_GANG(bp) == BP_GET_NDVAS(bp)));
4203 }
4204 if (zio->io_flags & ZIO_FLAG_NOPWRITE)
4205 VERIFY(BP_EQUAL(bp, &zio->io_bp_orig));
4206 }
4207
4208 /*
4209 * If there were child vdev/gang/ddt errors, they apply to us now.
4210 */
4211 zio_inherit_child_errors(zio, ZIO_CHILD_VDEV);
4212 zio_inherit_child_errors(zio, ZIO_CHILD_GANG);
4213 zio_inherit_child_errors(zio, ZIO_CHILD_DDT);
4214
4215 /*
4216 * If the I/O on the transformed data was successful, generate any
4217 * checksum reports now while we still have the transformed data.
4218 */
4219 if (zio->io_error == 0) {
4220 while (zio->io_cksum_report != NULL) {
4221 zio_cksum_report_t *zcr = zio->io_cksum_report;
4222 uint64_t align = zcr->zcr_align;
4223 uint64_t asize = P2ROUNDUP(psize, align);
4224 abd_t *adata = zio->io_abd;
4225
4226 if (asize != psize) {
4227 adata = abd_alloc(asize, B_TRUE);
4228 abd_copy(adata, zio->io_abd, psize);
4229 abd_zero_off(adata, psize, asize - psize);
4230 }
4231
4232 zio->io_cksum_report = zcr->zcr_next;
4233 zcr->zcr_next = NULL;
4234 zcr->zcr_finish(zcr, adata);
4235 zfs_ereport_free_checksum(zcr);
4236
4237 if (asize != psize)
4238 abd_free(adata);
4239 }
4240 }
4241
4242 zio_pop_transforms(zio); /* note: may set zio->io_error */
4243
4244 vdev_stat_update(zio, psize);
4245
4246 if (zio->io_delay >= MSEC2NSEC(zio_slow_io_ms)) {
4247 if (zio->io_vd != NULL && !vdev_is_dead(zio->io_vd)) {
4248 /*
4249 * We want to only increment our slow IO counters if
4250 * the IO is valid (i.e. not if the drive is removed).
4251 *
4252 * zfs_ereport_post() will also do these checks, but
4253 * it can also have other failures, so we need to
4254 * increment the slow_io counters independent of it.
4255 */
4256 if (zfs_ereport_is_valid(FM_EREPORT_ZFS_DELAY,
4257 zio->io_spa, zio->io_vd, zio)) {
4258 mutex_enter(&zio->io_vd->vdev_stat_lock);
4259 zio->io_vd->vdev_stat.vs_slow_ios++;
4260 mutex_exit(&zio->io_vd->vdev_stat_lock);
4261
4262 zfs_ereport_post(FM_EREPORT_ZFS_DELAY,
4263 zio->io_spa, zio->io_vd, &zio->io_bookmark,
4264 zio, 0, 0);
4265 }
4266 }
4267 }
4268
4269 if (zio->io_error) {
4270 /*
4271 * If this I/O is attached to a particular vdev,
4272 * generate an error message describing the I/O failure
4273 * at the block level. We ignore these errors if the
4274 * device is currently unavailable.
4275 */
4276 if (zio->io_error != ECKSUM && vd != NULL && !vdev_is_dead(vd))
4277 zfs_ereport_post(FM_EREPORT_ZFS_IO, spa, vd,
4278 &zio->io_bookmark, zio, 0, 0);
4279
4280 if ((zio->io_error == EIO || !(zio->io_flags &
4281 (ZIO_FLAG_SPECULATIVE | ZIO_FLAG_DONT_PROPAGATE))) &&
4282 zio == lio) {
4283 /*
4284 * For logical I/O requests, tell the SPA to log the
4285 * error and generate a logical data ereport.
4286 */
4287 spa_log_error(spa, &zio->io_bookmark);
4288 zfs_ereport_post(FM_EREPORT_ZFS_DATA, spa, NULL,
4289 &zio->io_bookmark, zio, 0, 0);
4290 }
4291 }
4292
4293 if (zio->io_error && zio == lio) {
4294 /*
4295 * Determine whether zio should be reexecuted. This will
4296 * propagate all the way to the root via zio_notify_parent().
4297 */
4298 ASSERT(vd == NULL && bp != NULL);
4299 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
4300
4301 if (IO_IS_ALLOCATING(zio) &&
4302 !(zio->io_flags & ZIO_FLAG_CANFAIL)) {
4303 if (zio->io_error != ENOSPC)
4304 zio->io_reexecute |= ZIO_REEXECUTE_NOW;
4305 else
4306 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND;
4307 }
4308
4309 if ((zio->io_type == ZIO_TYPE_READ ||
4310 zio->io_type == ZIO_TYPE_FREE) &&
4311 !(zio->io_flags & ZIO_FLAG_SCAN_THREAD) &&
4312 zio->io_error == ENXIO &&
4313 spa_load_state(spa) == SPA_LOAD_NONE &&
4314 spa_get_failmode(spa) != ZIO_FAILURE_MODE_CONTINUE)
4315 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND;
4316
4317 if (!(zio->io_flags & ZIO_FLAG_CANFAIL) && !zio->io_reexecute)
4318 zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND;
4319
4320 /*
4321 * Here is a possibly good place to attempt to do
4322 * either combinatorial reconstruction or error correction
4323 * based on checksums. It also might be a good place
4324 * to send out preliminary ereports before we suspend
4325 * processing.
4326 */
4327 }
4328
4329 /*
4330 * If there were logical child errors, they apply to us now.
4331 * We defer this until now to avoid conflating logical child
4332 * errors with errors that happened to the zio itself when
4333 * updating vdev stats and reporting FMA events above.
4334 */
4335 zio_inherit_child_errors(zio, ZIO_CHILD_LOGICAL);
4336
4337 if ((zio->io_error || zio->io_reexecute) &&
4338 IO_IS_ALLOCATING(zio) && zio->io_gang_leader == zio &&
4339 !(zio->io_flags & (ZIO_FLAG_IO_REWRITE | ZIO_FLAG_NOPWRITE)))
4340 zio_dva_unallocate(zio, zio->io_gang_tree, bp);
4341
4342 zio_gang_tree_free(&zio->io_gang_tree);
4343
4344 /*
4345 * Godfather I/Os should never suspend.
4346 */
4347 if ((zio->io_flags & ZIO_FLAG_GODFATHER) &&
4348 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND))
4349 zio->io_reexecute = 0;
4350
4351 if (zio->io_reexecute) {
4352 /*
4353 * This is a logical I/O that wants to reexecute.
4354 *
4355 * Reexecute is top-down. When an i/o fails, if it's not
4356 * the root, it simply notifies its parent and sticks around.
4357 * The parent, seeing that it still has children in zio_done(),
4358 * does the same. This percolates all the way up to the root.
4359 * The root i/o will reexecute or suspend the entire tree.
4360 *
4361 * This approach ensures that zio_reexecute() honors
4362 * all the original i/o dependency relationships, e.g.
4363 * parents not executing until children are ready.
4364 */
4365 ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
4366
4367 zio->io_gang_leader = NULL;
4368
4369 mutex_enter(&zio->io_lock);
4370 zio->io_state[ZIO_WAIT_DONE] = 1;
4371 mutex_exit(&zio->io_lock);
4372
4373 /*
4374 * "The Godfather" I/O monitors its children but is
4375 * not a true parent to them. It will track them through
4376 * the pipeline but severs its ties whenever they get into
4377 * trouble (e.g. suspended). This allows "The Godfather"
4378 * I/O to return status without blocking.
4379 */
4380 zl = NULL;
4381 for (pio = zio_walk_parents(zio, &zl); pio != NULL;
4382 pio = pio_next) {
4383 zio_link_t *remove_zl = zl;
4384 pio_next = zio_walk_parents(zio, &zl);
4385
4386 if ((pio->io_flags & ZIO_FLAG_GODFATHER) &&
4387 (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND)) {
4388 zio_remove_child(pio, zio, remove_zl);
4389 zio_notify_parent(pio, zio, ZIO_WAIT_DONE);
4390 }
4391 }
4392
4393 if ((pio = zio_unique_parent(zio)) != NULL) {
4394 /*
4395 * We're not a root i/o, so there's nothing to do
4396 * but notify our parent. Don't propagate errors
4397 * upward since we haven't permanently failed yet.
4398 */
4399 ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER));
4400 zio->io_flags |= ZIO_FLAG_DONT_PROPAGATE;
4401 zio_notify_parent(pio, zio, ZIO_WAIT_DONE);
4402 } else if (zio->io_reexecute & ZIO_REEXECUTE_SUSPEND) {
4403 /*
4404 * We'd fail again if we reexecuted now, so suspend
4405 * until conditions improve (e.g. device comes online).
4406 */
4407 zio_suspend(zio->io_spa, zio, ZIO_SUSPEND_IOERR);
4408 } else {
4409 /*
4410 * Reexecution is potentially a huge amount of work.
4411 * Hand it off to the otherwise-unused claim taskq.
4412 */
4413 ASSERT(zio->io_tqent.tqent_next == NULL);
4414 spa_taskq_dispatch_ent(spa, ZIO_TYPE_CLAIM,
4415 ZIO_TASKQ_ISSUE, (task_func_t *)zio_reexecute, zio,
4416 0, &zio->io_tqent);
4417 }
4418 return (ZIO_PIPELINE_STOP);
4419 }
4420
4421 ASSERT(zio->io_child_count == 0);
4422 ASSERT(zio->io_reexecute == 0);
4423 ASSERT(zio->io_error == 0 || (zio->io_flags & ZIO_FLAG_CANFAIL));
4424
4425 /*
4426 * Report any checksum errors, since the I/O is complete.
4427 */
4428 while (zio->io_cksum_report != NULL) {
4429 zio_cksum_report_t *zcr = zio->io_cksum_report;
4430 zio->io_cksum_report = zcr->zcr_next;
4431 zcr->zcr_next = NULL;
4432 zcr->zcr_finish(zcr, NULL);
4433 zfs_ereport_free_checksum(zcr);
4434 }
4435
4436 /*
4437 * It is the responsibility of the done callback to ensure that this
4438 * particular zio is no longer discoverable for adoption, and as
4439 * such, cannot acquire any new parents.
4440 */
4441 if (zio->io_done)
4442 zio->io_done(zio);
4443
4444 mutex_enter(&zio->io_lock);
4445 zio->io_state[ZIO_WAIT_DONE] = 1;
4446 mutex_exit(&zio->io_lock);
4447
4448 zl = NULL;
4449 for (pio = zio_walk_parents(zio, &zl); pio != NULL; pio = pio_next) {
4450 zio_link_t *remove_zl = zl;
4451 pio_next = zio_walk_parents(zio, &zl);
4452 zio_remove_child(pio, zio, remove_zl);
4453 zio_notify_parent(pio, zio, ZIO_WAIT_DONE);
4454 }
4455
4456 if (zio->io_waiter != NULL) {
4457 mutex_enter(&zio->io_lock);
4458 zio->io_executor = NULL;
4459 cv_broadcast(&zio->io_cv);
4460 mutex_exit(&zio->io_lock);
4461 } else {
4462 zio_destroy(zio);
4463 }
4464
4465 return (ZIO_PIPELINE_STOP);
4466 }
4467
4468 /*
4469 * ==========================================================================
4470 * I/O pipeline definition
4471 * ==========================================================================
4472 */
4473 static zio_pipe_stage_t *zio_pipeline[] = {
4474 NULL,
4475 zio_read_bp_init,
4476 zio_write_bp_init,
4477 zio_free_bp_init,
4478 zio_issue_async,
4479 zio_write_compress,
4480 zio_encrypt,
4481 zio_checksum_generate,
4482 zio_nop_write,
4483 zio_ddt_read_start,
4484 zio_ddt_read_done,
4485 zio_ddt_write,
4486 zio_ddt_free,
4487 zio_gang_assemble,
4488 zio_gang_issue,
4489 zio_dva_throttle,
4490 zio_dva_allocate,
4491 zio_dva_free,
4492 zio_dva_claim,
4493 zio_ready,
4494 zio_vdev_io_start,
4495 zio_vdev_io_done,
4496 zio_vdev_io_assess,
4497 zio_checksum_verify,
4498 zio_done
4499 };
4500
4501
4502
4503
4504 /*
4505 * Compare two zbookmark_phys_t's to see which we would reach first in a
4506 * pre-order traversal of the object tree.
4507 *
4508 * This is simple in every case aside from the meta-dnode object. For all other
4509 * objects, we traverse them in order (object 1 before object 2, and so on).
4510 * However, all of these objects are traversed while traversing object 0, since
4511 * the data it points to is the list of objects. Thus, we need to convert to a
4512 * canonical representation so we can compare meta-dnode bookmarks to
4513 * non-meta-dnode bookmarks.
4514 *
4515 * We do this by calculating "equivalents" for each field of the zbookmark.
4516 * zbookmarks outside of the meta-dnode use their own object and level, and
4517 * calculate the level 0 equivalent (the first L0 blkid that is contained in the
4518 * blocks this bookmark refers to) by multiplying their blkid by their span
4519 * (the number of L0 blocks contained within one block at their level).
4520 * zbookmarks inside the meta-dnode calculate their object equivalent
4521 * (which is L0equiv * dnodes per data block), use 0 for their L0equiv, and use
4522 * level + 1<<31 (any value larger than a level could ever be) for their level.
4523 * This causes them to always compare before a bookmark in their object
4524 * equivalent, compare appropriately to bookmarks in other objects, and to
4525 * compare appropriately to other bookmarks in the meta-dnode.
4526 */
4527 int
4528 zbookmark_compare(uint16_t dbss1, uint8_t ibs1, uint16_t dbss2, uint8_t ibs2,
4529 const zbookmark_phys_t *zb1, const zbookmark_phys_t *zb2)
4530 {
4531 /*
4532 * These variables represent the "equivalent" values for the zbookmark,
4533 * after converting zbookmarks inside the meta dnode to their
4534 * normal-object equivalents.
4535 */
4536 uint64_t zb1obj, zb2obj;
4537 uint64_t zb1L0, zb2L0;
4538 uint64_t zb1level, zb2level;
4539
4540 if (zb1->zb_object == zb2->zb_object &&
4541 zb1->zb_level == zb2->zb_level &&
4542 zb1->zb_blkid == zb2->zb_blkid)
4543 return (0);
4544
4545 /*
4546 * BP_SPANB calculates the span in blocks.
4547 */
4548 zb1L0 = (zb1->zb_blkid) * BP_SPANB(ibs1, zb1->zb_level);
4549 zb2L0 = (zb2->zb_blkid) * BP_SPANB(ibs2, zb2->zb_level);
4550
4551 if (zb1->zb_object == DMU_META_DNODE_OBJECT) {
4552 zb1obj = zb1L0 * (dbss1 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT));
4553 zb1L0 = 0;
4554 zb1level = zb1->zb_level + COMPARE_META_LEVEL;
4555 } else {
4556 zb1obj = zb1->zb_object;
4557 zb1level = zb1->zb_level;
4558 }
4559
4560 if (zb2->zb_object == DMU_META_DNODE_OBJECT) {
4561 zb2obj = zb2L0 * (dbss2 << (SPA_MINBLOCKSHIFT - DNODE_SHIFT));
4562 zb2L0 = 0;
4563 zb2level = zb2->zb_level + COMPARE_META_LEVEL;
4564 } else {
4565 zb2obj = zb2->zb_object;
4566 zb2level = zb2->zb_level;
4567 }
4568
4569 /* Now that we have a canonical representation, do the comparison. */
4570 if (zb1obj != zb2obj)
4571 return (zb1obj < zb2obj ? -1 : 1);
4572 else if (zb1L0 != zb2L0)
4573 return (zb1L0 < zb2L0 ? -1 : 1);
4574 else if (zb1level != zb2level)
4575 return (zb1level > zb2level ? -1 : 1);
4576 /*
4577 * This can (theoretically) happen if the bookmarks have the same object
4578 * and level, but different blkids, if the block sizes are not the same.
4579 * There is presently no way to change the indirect block sizes
4580 */
4581 return (0);
4582 }
4583
4584 /*
4585 * This function checks the following: given that last_block is the place that
4586 * our traversal stopped last time, does that guarantee that we've visited
4587 * every node under subtree_root? Therefore, we can't just use the raw output
4588 * of zbookmark_compare. We have to pass in a modified version of
4589 * subtree_root; by incrementing the block id, and then checking whether
4590 * last_block is before or equal to that, we can tell whether or not having
4591 * visited last_block implies that all of subtree_root's children have been
4592 * visited.
4593 */
4594 boolean_t
4595 zbookmark_subtree_completed(const dnode_phys_t *dnp,
4596 const zbookmark_phys_t *subtree_root, const zbookmark_phys_t *last_block)
4597 {
4598 zbookmark_phys_t mod_zb = *subtree_root;
4599 mod_zb.zb_blkid++;
4600 ASSERT(last_block->zb_level == 0);
4601
4602 /* The objset_phys_t isn't before anything. */
4603 if (dnp == NULL)
4604 return (B_FALSE);
4605
4606 /*
4607 * We pass in 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT) for the
4608 * data block size in sectors, because that variable is only used if
4609 * the bookmark refers to a block in the meta-dnode. Since we don't
4610 * know without examining it what object it refers to, and there's no
4611 * harm in passing in this value in other cases, we always pass it in.
4612 *
4613 * We pass in 0 for the indirect block size shift because zb2 must be
4614 * level 0. The indirect block size is only used to calculate the span
4615 * of the bookmark, but since the bookmark must be level 0, the span is
4616 * always 1, so the math works out.
4617 *
4618 * If you make changes to how the zbookmark_compare code works, be sure
4619 * to make sure that this code still works afterwards.
4620 */
4621 return (zbookmark_compare(dnp->dn_datablkszsec, dnp->dn_indblkshift,
4622 1ULL << (DNODE_BLOCK_SHIFT - SPA_MINBLOCKSHIFT), 0, &mod_zb,
4623 last_block) <= 0);
4624 }