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) 2012, 2016 by Delphix. All rights reserved.
24 */
25
26 #include <sys/zfs_context.h>
27 #include <sys/dmu_objset.h>
28 #include <sys/dmu_traverse.h>
29 #include <sys/dsl_dataset.h>
30 #include <sys/dsl_dir.h>
31 #include <sys/dsl_pool.h>
32 #include <sys/dnode.h>
33 #include <sys/spa.h>
34 #include <sys/zio.h>
35 #include <sys/dmu_impl.h>
36 #include <sys/sa.h>
37 #include <sys/sa_impl.h>
38 #include <sys/callb.h>
39 #include <sys/zfeature.h>
40
41 int32_t zfs_pd_bytes_max = 50 * 1024 * 1024; /* 50MB */
42 boolean_t send_holes_without_birth_time = B_TRUE;
43
44 typedef struct prefetch_data {
45 kmutex_t pd_mtx;
46 kcondvar_t pd_cv;
47 int32_t pd_bytes_fetched;
48 int pd_flags;
49 boolean_t pd_cancel;
50 boolean_t pd_exited;
51 zbookmark_phys_t pd_resume;
52 } prefetch_data_t;
53
54 typedef struct traverse_data {
55 spa_t *td_spa;
56 uint64_t td_objset;
57 blkptr_t *td_rootbp;
58 uint64_t td_min_txg;
59 zbookmark_phys_t *td_resume;
60 int td_flags;
61 prefetch_data_t *td_pfd;
62 boolean_t td_paused;
63 uint64_t td_hole_birth_enabled_txg;
64 blkptr_cb_t *td_func;
65 void *td_arg;
66 boolean_t td_realloc_possible;
67 } traverse_data_t;
68
69 static int traverse_dnode(traverse_data_t *td, const dnode_phys_t *dnp,
70 uint64_t objset, uint64_t object);
71 static void prefetch_dnode_metadata(traverse_data_t *td, const dnode_phys_t *,
72 uint64_t objset, uint64_t object);
73
74 static int
75 traverse_zil_block(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg)
76 {
77 traverse_data_t *td = arg;
78 zbookmark_phys_t zb;
79
80 if (BP_IS_HOLE(bp))
81 return (0);
82
83 if (claim_txg == 0 && bp->blk_birth >= spa_first_txg(td->td_spa))
84 return (0);
85
86 SET_BOOKMARK(&zb, td->td_objset, ZB_ZIL_OBJECT, ZB_ZIL_LEVEL,
87 bp->blk_cksum.zc_word[ZIL_ZC_SEQ]);
88
89 (void) td->td_func(td->td_spa, zilog, bp, &zb, NULL, td->td_arg);
90
91 return (0);
92 }
93
94 static int
95 traverse_zil_record(zilog_t *zilog, lr_t *lrc, void *arg, uint64_t claim_txg)
96 {
97 traverse_data_t *td = arg;
98
99 if (lrc->lrc_txtype == TX_WRITE) {
100 lr_write_t *lr = (lr_write_t *)lrc;
101 blkptr_t *bp = &lr->lr_blkptr;
102 zbookmark_phys_t zb;
103
104 if (BP_IS_HOLE(bp))
105 return (0);
106
107 if (claim_txg == 0 || bp->blk_birth < claim_txg)
108 return (0);
109
110 SET_BOOKMARK(&zb, td->td_objset, lr->lr_foid,
111 ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp));
112
113 (void) td->td_func(td->td_spa, zilog, bp, &zb, NULL,
114 td->td_arg);
115 }
116 return (0);
117 }
118
119 static void
120 traverse_zil(traverse_data_t *td, zil_header_t *zh)
121 {
122 uint64_t claim_txg = zh->zh_claim_txg;
123 zilog_t *zilog;
124
125 /*
126 * We only want to visit blocks that have been claimed but not yet
127 * replayed; plus, in read-only mode, blocks that are already stable.
128 */
129 if (claim_txg == 0 && spa_writeable(td->td_spa))
130 return;
131
132 zilog = zil_alloc(spa_get_dsl(td->td_spa)->dp_meta_objset, zh);
133
134 (void) zil_parse(zilog, traverse_zil_block, traverse_zil_record, td,
135 claim_txg);
136
137 zil_free(zilog);
138 }
139
140 typedef enum resume_skip {
141 RESUME_SKIP_ALL,
142 RESUME_SKIP_NONE,
143 RESUME_SKIP_CHILDREN
144 } resume_skip_t;
145
146 /*
147 * Returns RESUME_SKIP_ALL if td indicates that we are resuming a traversal and
148 * the block indicated by zb does not need to be visited at all. Returns
149 * RESUME_SKIP_CHILDREN if we are resuming a post traversal and we reach the
150 * resume point. This indicates that this block should be visited but not its
151 * children (since they must have been visited in a previous traversal).
152 * Otherwise returns RESUME_SKIP_NONE.
153 */
154 static resume_skip_t
155 resume_skip_check(traverse_data_t *td, const dnode_phys_t *dnp,
156 const zbookmark_phys_t *zb)
157 {
158 if (td->td_resume != NULL && !ZB_IS_ZERO(td->td_resume)) {
159 /*
160 * If we already visited this bp & everything below,
161 * don't bother doing it again.
162 */
163 if (zbookmark_subtree_completed(dnp, zb, td->td_resume))
164 return (RESUME_SKIP_ALL);
165
166 /*
167 * If we found the block we're trying to resume from, zero
168 * the bookmark out to indicate that we have resumed.
169 */
170 if (bcmp(zb, td->td_resume, sizeof (*zb)) == 0) {
171 bzero(td->td_resume, sizeof (*zb));
172 if (td->td_flags & TRAVERSE_POST)
173 return (RESUME_SKIP_CHILDREN);
174 }
175 }
176 return (RESUME_SKIP_NONE);
177 }
178
179 static void
180 traverse_prefetch_metadata(traverse_data_t *td,
181 const blkptr_t *bp, const zbookmark_phys_t *zb)
182 {
183 arc_flags_t flags = ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH;
184
185 if (!(td->td_flags & TRAVERSE_PREFETCH_METADATA))
186 return;
187 /*
188 * If we are in the process of resuming, don't prefetch, because
189 * some children will not be needed (and in fact may have already
190 * been freed).
191 */
192 if (td->td_resume != NULL && !ZB_IS_ZERO(td->td_resume))
193 return;
194 if (BP_IS_HOLE(bp) || bp->blk_birth <= td->td_min_txg)
195 return;
196 if (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_DNODE)
197 return;
198
199 (void) arc_read(NULL, td->td_spa, bp, NULL, NULL,
200 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
201 }
202
203 static boolean_t
204 prefetch_needed(prefetch_data_t *pfd, const blkptr_t *bp)
205 {
206 ASSERT(pfd->pd_flags & TRAVERSE_PREFETCH_DATA);
207 if (BP_IS_HOLE(bp) || BP_IS_EMBEDDED(bp) ||
208 BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG)
209 return (B_FALSE);
210 return (B_TRUE);
211 }
212
213 static int
214 traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp,
215 const blkptr_t *bp, const zbookmark_phys_t *zb)
216 {
217 zbookmark_phys_t czb;
218 int err = 0;
219 arc_buf_t *buf = NULL;
220 prefetch_data_t *pd = td->td_pfd;
221 boolean_t hard = td->td_flags & TRAVERSE_HARD;
222
223 switch (resume_skip_check(td, dnp, zb)) {
224 case RESUME_SKIP_ALL:
225 return (0);
226 case RESUME_SKIP_CHILDREN:
227 goto post;
228 case RESUME_SKIP_NONE:
229 break;
230 default:
231 ASSERT(0);
232 }
233
234 if (bp->blk_birth == 0) {
235 /*
236 * Since this block has a birth time of 0 it must be one of
237 * two things: a hole created before the
238 * SPA_FEATURE_HOLE_BIRTH feature was enabled, or a hole
239 * which has always been a hole in an object.
240 *
241 * If a file is written sparsely, then the unwritten parts of
242 * the file were "always holes" -- that is, they have been
243 * holes since this object was allocated. However, we (and
244 * our callers) can not necessarily tell when an object was
245 * allocated. Therefore, if it's possible that this object
246 * was freed and then its object number reused, we need to
247 * visit all the holes with birth==0.
248 *
249 * If it isn't possible that the object number was reused,
250 * then if SPA_FEATURE_HOLE_BIRTH was enabled before we wrote
251 * all the blocks we will visit as part of this traversal,
252 * then this hole must have always existed, so we can skip
253 * it. We visit blocks born after (exclusive) td_min_txg.
254 *
255 * Note that the meta-dnode cannot be reallocated.
256 */
257 if (!send_holes_without_birth_time &&
258 (!td->td_realloc_possible ||
259 zb->zb_object == DMU_META_DNODE_OBJECT) &&
260 td->td_hole_birth_enabled_txg <= td->td_min_txg)
261 return (0);
262 } else if (bp->blk_birth <= td->td_min_txg) {
263 return (0);
264 }
265
266 if (pd != NULL && !pd->pd_exited && prefetch_needed(pd, bp)) {
267 uint64_t size = BP_GET_LSIZE(bp);
268 mutex_enter(&pd->pd_mtx);
269 ASSERT(pd->pd_bytes_fetched >= 0);
270 while (pd->pd_bytes_fetched < size && !pd->pd_exited)
271 cv_wait(&pd->pd_cv, &pd->pd_mtx);
272 pd->pd_bytes_fetched -= size;
273 cv_broadcast(&pd->pd_cv);
274 mutex_exit(&pd->pd_mtx);
275 }
276
277 if (BP_IS_HOLE(bp)) {
278 err = td->td_func(td->td_spa, NULL, bp, zb, dnp, td->td_arg);
279 if (err != 0)
280 goto post;
281 return (0);
282 }
283
284 if (td->td_flags & TRAVERSE_PRE) {
285 err = td->td_func(td->td_spa, NULL, bp, zb, dnp,
286 td->td_arg);
287 if (err == TRAVERSE_VISIT_NO_CHILDREN)
288 return (0);
289 if (err != 0)
290 goto post;
291 }
292
293 if (BP_GET_LEVEL(bp) > 0) {
294 arc_flags_t flags = ARC_FLAG_WAIT;
295 int i;
296 blkptr_t *cbp;
297 int epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT;
298
299 err = arc_read(NULL, td->td_spa, bp, arc_getbuf_func, &buf,
300 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
301 if (err != 0)
302 goto post;
303 cbp = buf->b_data;
304
305 for (i = 0; i < epb; i++) {
306 SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object,
307 zb->zb_level - 1,
308 zb->zb_blkid * epb + i);
309 traverse_prefetch_metadata(td, &cbp[i], &czb);
310 }
311
312 /* recursively visitbp() blocks below this */
313 for (i = 0; i < epb; i++) {
314 SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object,
315 zb->zb_level - 1,
316 zb->zb_blkid * epb + i);
317 err = traverse_visitbp(td, dnp, &cbp[i], &czb);
318 if (err != 0)
319 break;
320 }
321 } else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) {
322 arc_flags_t flags = ARC_FLAG_WAIT;
323 int i;
324 int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT;
325
326 err = arc_read(NULL, td->td_spa, bp, arc_getbuf_func, &buf,
327 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
328 if (err != 0)
329 goto post;
330 dnode_phys_t *child_dnp = buf->b_data;
331
332 for (i = 0; i < epb; i++) {
333 prefetch_dnode_metadata(td, &child_dnp[i],
334 zb->zb_objset, zb->zb_blkid * epb + i);
335 }
336
337 /* recursively visitbp() blocks below this */
338 for (i = 0; i < epb; i++) {
339 err = traverse_dnode(td, &child_dnp[i],
340 zb->zb_objset, zb->zb_blkid * epb + i);
341 if (err != 0)
342 break;
343 }
344 } else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) {
345 arc_flags_t flags = ARC_FLAG_WAIT;
346
347 err = arc_read(NULL, td->td_spa, bp, arc_getbuf_func, &buf,
348 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
349 if (err != 0)
350 goto post;
351
352 objset_phys_t *osp = buf->b_data;
353 prefetch_dnode_metadata(td, &osp->os_meta_dnode, zb->zb_objset,
354 DMU_META_DNODE_OBJECT);
355 /*
356 * See the block comment above for the goal of this variable.
357 * If the maxblkid of the meta-dnode is 0, then we know that
358 * we've never had more than DNODES_PER_BLOCK objects in the
359 * dataset, which means we can't have reused any object ids.
360 */
361 if (osp->os_meta_dnode.dn_maxblkid == 0)
362 td->td_realloc_possible = B_FALSE;
363
364 if (arc_buf_size(buf) >= sizeof (objset_phys_t)) {
365 prefetch_dnode_metadata(td, &osp->os_groupused_dnode,
366 zb->zb_objset, DMU_GROUPUSED_OBJECT);
367 prefetch_dnode_metadata(td, &osp->os_userused_dnode,
368 zb->zb_objset, DMU_USERUSED_OBJECT);
369 }
370
371 err = traverse_dnode(td, &osp->os_meta_dnode, zb->zb_objset,
372 DMU_META_DNODE_OBJECT);
373 if (err == 0 && arc_buf_size(buf) >= sizeof (objset_phys_t)) {
374 err = traverse_dnode(td, &osp->os_groupused_dnode,
375 zb->zb_objset, DMU_GROUPUSED_OBJECT);
376 }
377 if (err == 0 && arc_buf_size(buf) >= sizeof (objset_phys_t)) {
378 err = traverse_dnode(td, &osp->os_userused_dnode,
379 zb->zb_objset, DMU_USERUSED_OBJECT);
380 }
381 }
382
383 if (buf)
384 arc_buf_destroy(buf, &buf);
385
386 post:
387 if (err == 0 && (td->td_flags & TRAVERSE_POST))
388 err = td->td_func(td->td_spa, NULL, bp, zb, dnp, td->td_arg);
389
390 if (hard && (err == EIO || err == ECKSUM)) {
391 /*
392 * Ignore this disk error as requested by the HARD flag,
393 * and continue traversal.
394 */
395 err = 0;
396 }
397
398 /*
399 * If we are stopping here, set td_resume.
400 */
401 if (td->td_resume != NULL && err != 0 && !td->td_paused) {
402 td->td_resume->zb_objset = zb->zb_objset;
403 td->td_resume->zb_object = zb->zb_object;
404 td->td_resume->zb_level = 0;
405 /*
406 * If we have stopped on an indirect block (e.g. due to
407 * i/o error), we have not visited anything below it.
408 * Set the bookmark to the first level-0 block that we need
409 * to visit. This way, the resuming code does not need to
410 * deal with resuming from indirect blocks.
411 *
412 * Note, if zb_level <= 0, dnp may be NULL, so we don't want
413 * to dereference it.
414 */
415 td->td_resume->zb_blkid = zb->zb_blkid;
416 if (zb->zb_level > 0) {
417 td->td_resume->zb_blkid <<= zb->zb_level *
418 (dnp->dn_indblkshift - SPA_BLKPTRSHIFT);
419 }
420 td->td_paused = B_TRUE;
421 }
422
423 return (err);
424 }
425
426 static void
427 prefetch_dnode_metadata(traverse_data_t *td, const dnode_phys_t *dnp,
428 uint64_t objset, uint64_t object)
429 {
430 int j;
431 zbookmark_phys_t czb;
432
433 for (j = 0; j < dnp->dn_nblkptr; j++) {
434 SET_BOOKMARK(&czb, objset, object, dnp->dn_nlevels - 1, j);
435 traverse_prefetch_metadata(td, &dnp->dn_blkptr[j], &czb);
436 }
437
438 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
439 SET_BOOKMARK(&czb, objset, object, 0, DMU_SPILL_BLKID);
440 traverse_prefetch_metadata(td, &dnp->dn_spill, &czb);
441 }
442 }
443
444 static int
445 traverse_dnode(traverse_data_t *td, const dnode_phys_t *dnp,
446 uint64_t objset, uint64_t object)
447 {
448 int j, err = 0;
449 zbookmark_phys_t czb;
450
451 if (object != DMU_META_DNODE_OBJECT && td->td_resume != NULL &&
452 object < td->td_resume->zb_object)
453 return (0);
454
455 if (td->td_flags & TRAVERSE_PRE) {
456 SET_BOOKMARK(&czb, objset, object, ZB_DNODE_LEVEL,
457 ZB_DNODE_BLKID);
458 err = td->td_func(td->td_spa, NULL, NULL, &czb, dnp,
459 td->td_arg);
460 if (err == TRAVERSE_VISIT_NO_CHILDREN)
461 return (0);
462 if (err != 0)
463 return (err);
464 }
465
466 for (j = 0; j < dnp->dn_nblkptr; j++) {
467 SET_BOOKMARK(&czb, objset, object, dnp->dn_nlevels - 1, j);
468 err = traverse_visitbp(td, dnp, &dnp->dn_blkptr[j], &czb);
469 if (err != 0)
470 break;
471 }
472
473 if (err == 0 && (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR)) {
474 SET_BOOKMARK(&czb, objset, object, 0, DMU_SPILL_BLKID);
475 err = traverse_visitbp(td, dnp, &dnp->dn_spill, &czb);
476 }
477
478 if (err == 0 && (td->td_flags & TRAVERSE_POST)) {
479 SET_BOOKMARK(&czb, objset, object, ZB_DNODE_LEVEL,
480 ZB_DNODE_BLKID);
481 err = td->td_func(td->td_spa, NULL, NULL, &czb, dnp,
482 td->td_arg);
483 if (err == TRAVERSE_VISIT_NO_CHILDREN)
484 return (0);
485 if (err != 0)
486 return (err);
487 }
488 return (err);
489 }
490
491 /* ARGSUSED */
492 static int
493 traverse_prefetcher(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
494 const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
495 {
496 prefetch_data_t *pfd = arg;
497 arc_flags_t aflags = ARC_FLAG_NOWAIT | ARC_FLAG_PREFETCH;
498
499 ASSERT(pfd->pd_bytes_fetched >= 0);
500 if (bp == NULL)
501 return (0);
502 if (pfd->pd_cancel)
503 return (SET_ERROR(EINTR));
504
505 if (!prefetch_needed(pfd, bp))
506 return (0);
507
508 mutex_enter(&pfd->pd_mtx);
509 while (!pfd->pd_cancel && pfd->pd_bytes_fetched >= zfs_pd_bytes_max)
510 cv_wait(&pfd->pd_cv, &pfd->pd_mtx);
511 pfd->pd_bytes_fetched += BP_GET_LSIZE(bp);
512 cv_broadcast(&pfd->pd_cv);
513 mutex_exit(&pfd->pd_mtx);
514
515 (void) arc_read(NULL, spa, bp, NULL, NULL, ZIO_PRIORITY_ASYNC_READ,
516 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, &aflags, zb);
517
518 return (0);
519 }
520
521 static void
522 traverse_prefetch_thread(void *arg)
523 {
524 traverse_data_t *td_main = arg;
525 traverse_data_t td = *td_main;
526 zbookmark_phys_t czb;
527
528 td.td_func = traverse_prefetcher;
529 td.td_arg = td_main->td_pfd;
530 td.td_pfd = NULL;
531 td.td_resume = &td_main->td_pfd->pd_resume;
532
533 SET_BOOKMARK(&czb, td.td_objset,
534 ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
535 (void) traverse_visitbp(&td, NULL, td.td_rootbp, &czb);
536
537 mutex_enter(&td_main->td_pfd->pd_mtx);
538 td_main->td_pfd->pd_exited = B_TRUE;
539 cv_broadcast(&td_main->td_pfd->pd_cv);
540 mutex_exit(&td_main->td_pfd->pd_mtx);
541 }
542
543 /*
544 * NB: dataset must not be changing on-disk (eg, is a snapshot or we are
545 * in syncing context).
546 */
547 static int
548 traverse_impl(spa_t *spa, dsl_dataset_t *ds, uint64_t objset, blkptr_t *rootbp,
549 uint64_t txg_start, zbookmark_phys_t *resume, int flags,
550 blkptr_cb_t func, void *arg)
551 {
552 traverse_data_t td;
553 prefetch_data_t pd = { 0 };
554 zbookmark_phys_t czb;
555 int err;
556
557 ASSERT(ds == NULL || objset == ds->ds_object);
558 ASSERT(!(flags & TRAVERSE_PRE) || !(flags & TRAVERSE_POST));
559
560 td.td_spa = spa;
561 td.td_objset = objset;
562 td.td_rootbp = rootbp;
563 td.td_min_txg = txg_start;
564 td.td_resume = resume;
565 td.td_func = func;
566 td.td_arg = arg;
567 td.td_pfd = &pd;
568 td.td_flags = flags;
569 td.td_paused = B_FALSE;
570 td.td_realloc_possible = (txg_start == 0 ? B_FALSE : B_TRUE);
571
572 if (spa_feature_is_active(spa, SPA_FEATURE_HOLE_BIRTH)) {
573 VERIFY(spa_feature_enabled_txg(spa,
574 SPA_FEATURE_HOLE_BIRTH, &td.td_hole_birth_enabled_txg));
575 } else {
576 td.td_hole_birth_enabled_txg = UINT64_MAX;
577 }
578
579 pd.pd_flags = flags;
580 if (resume != NULL)
581 pd.pd_resume = *resume;
582 mutex_init(&pd.pd_mtx, NULL, MUTEX_DEFAULT, NULL);
583 cv_init(&pd.pd_cv, NULL, CV_DEFAULT, NULL);
584
585 /* See comment on ZIL traversal in dsl_scan_visitds. */
586 if (ds != NULL && !ds->ds_is_snapshot && !BP_IS_HOLE(rootbp)) {
587 arc_flags_t flags = ARC_FLAG_WAIT;
588 objset_phys_t *osp;
589 arc_buf_t *buf;
590
591 err = arc_read(NULL, td.td_spa, rootbp,
592 arc_getbuf_func, &buf,
593 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, NULL);
594 if (err != 0)
595 return (err);
596
597 osp = buf->b_data;
598 traverse_zil(&td, &osp->os_zil_header);
599 arc_buf_destroy(buf, &buf);
600 }
601
602 if (!(flags & TRAVERSE_PREFETCH_DATA) ||
603 0 == taskq_dispatch(system_taskq, traverse_prefetch_thread,
604 &td, TQ_NOQUEUE))
605 pd.pd_exited = B_TRUE;
606
607 SET_BOOKMARK(&czb, td.td_objset,
608 ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
609 err = traverse_visitbp(&td, NULL, rootbp, &czb);
610
611 mutex_enter(&pd.pd_mtx);
612 pd.pd_cancel = B_TRUE;
613 cv_broadcast(&pd.pd_cv);
614 while (!pd.pd_exited)
615 cv_wait(&pd.pd_cv, &pd.pd_mtx);
616 mutex_exit(&pd.pd_mtx);
617
618 mutex_destroy(&pd.pd_mtx);
619 cv_destroy(&pd.pd_cv);
620
621 return (err);
622 }
623
624 /*
625 * NB: dataset must not be changing on-disk (eg, is a snapshot or we are
626 * in syncing context).
627 */
628 int
629 traverse_dataset_resume(dsl_dataset_t *ds, uint64_t txg_start,
630 zbookmark_phys_t *resume,
631 int flags, blkptr_cb_t func, void *arg)
632 {
633 return (traverse_impl(ds->ds_dir->dd_pool->dp_spa, ds, ds->ds_object,
634 &dsl_dataset_phys(ds)->ds_bp, txg_start, resume, flags, func, arg));
635 }
636
637 int
638 traverse_dataset(dsl_dataset_t *ds, uint64_t txg_start,
639 int flags, blkptr_cb_t func, void *arg)
640 {
641 return (traverse_dataset_resume(ds, txg_start, NULL, flags, func, arg));
642 }
643
644 int
645 traverse_dataset_destroyed(spa_t *spa, blkptr_t *blkptr,
646 uint64_t txg_start, zbookmark_phys_t *resume, int flags,
647 blkptr_cb_t func, void *arg)
648 {
649 return (traverse_impl(spa, NULL, ZB_DESTROYED_OBJSET,
650 blkptr, txg_start, resume, flags, func, arg));
651 }
652
653 /*
654 * NB: pool must not be changing on-disk (eg, from zdb or sync context).
655 */
656 int
657 traverse_pool(spa_t *spa, uint64_t txg_start, int flags,
658 blkptr_cb_t func, void *arg)
659 {
660 int err;
661 dsl_pool_t *dp = spa_get_dsl(spa);
662 objset_t *mos = dp->dp_meta_objset;
663 boolean_t hard = (flags & TRAVERSE_HARD);
664
665 /* visit the MOS */
666 err = traverse_impl(spa, NULL, 0, spa_get_rootblkptr(spa),
667 txg_start, NULL, flags, func, arg);
668 if (err != 0)
669 return (err);
670
671 /* visit each dataset */
672 for (uint64_t obj = 1; err == 0;
673 err = dmu_object_next(mos, &obj, B_FALSE, txg_start)) {
674 dmu_object_info_t doi;
675
676 err = dmu_object_info(mos, obj, &doi);
677 if (err != 0) {
678 if (hard)
679 continue;
680 break;
681 }
682
683 if (doi.doi_bonus_type == DMU_OT_DSL_DATASET) {
684 dsl_dataset_t *ds;
685 uint64_t txg = txg_start;
686
687 dsl_pool_config_enter(dp, FTAG);
688 err = dsl_dataset_hold_obj(dp, obj, FTAG, &ds);
689 dsl_pool_config_exit(dp, FTAG);
690 if (err != 0) {
691 if (hard)
692 continue;
693 break;
694 }
695 if (dsl_dataset_phys(ds)->ds_prev_snap_txg > txg)
696 txg = dsl_dataset_phys(ds)->ds_prev_snap_txg;
697 err = traverse_dataset(ds, txg, flags, func, arg);
698 dsl_dataset_rele(ds, FTAG);
699 if (err != 0)
700 break;
701 }
702 }
703 if (err == ESRCH)
704 err = 0;
705 return (err);
706 }