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