Deleted Added
full compact
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 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
40int zfs_pd_blks_max = 100;
41
42typedef struct prefetch_data {
43 kmutex_t pd_mtx;
44 kcondvar_t pd_cv;
45 int pd_blks_max;
46 int pd_blks_fetched;
47 int pd_flags;
48 boolean_t pd_cancel;
49 boolean_t pd_exited;
50} prefetch_data_t;
51
52typedef struct traverse_data {
53 spa_t *td_spa;
54 uint64_t td_objset;
55 blkptr_t *td_rootbp;
56 uint64_t td_min_txg;
57 zbookmark_t *td_resume;
58 int td_flags;
59 prefetch_data_t *td_pfd;
60 blkptr_cb_t *td_func;
61 void *td_arg;
62} traverse_data_t;
63
64static int traverse_dnode(traverse_data_t *td, const dnode_phys_t *dnp,
65 arc_buf_t *buf, uint64_t objset, uint64_t object);
66static void prefetch_dnode_metadata(traverse_data_t *td, const dnode_phys_t *,
67 arc_buf_t *buf, uint64_t objset, uint64_t object);
68
69static int
70traverse_zil_block(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg)
71{
72 traverse_data_t *td = arg;
73 zbookmark_t zb;
74
75 if (bp->blk_birth == 0)
76 return (0);
77
78 if (claim_txg == 0 && bp->blk_birth >= spa_first_txg(td->td_spa))
79 return (0);
80
81 SET_BOOKMARK(&zb, td->td_objset, ZB_ZIL_OBJECT, ZB_ZIL_LEVEL,
82 bp->blk_cksum.zc_word[ZIL_ZC_SEQ]);
83
84 (void) td->td_func(td->td_spa, zilog, bp, NULL, &zb, NULL, td->td_arg);
85
86 return (0);
87}
88
89static int
90traverse_zil_record(zilog_t *zilog, lr_t *lrc, void *arg, uint64_t claim_txg)
91{
92 traverse_data_t *td = arg;
93
94 if (lrc->lrc_txtype == TX_WRITE) {
95 lr_write_t *lr = (lr_write_t *)lrc;
96 blkptr_t *bp = &lr->lr_blkptr;
97 zbookmark_t zb;
98
99 if (bp->blk_birth == 0)
100 return (0);
101
102 if (claim_txg == 0 || bp->blk_birth < claim_txg)
103 return (0);
104
105 SET_BOOKMARK(&zb, td->td_objset, lr->lr_foid,
106 ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp));
107
108 (void) td->td_func(td->td_spa, zilog, bp, NULL, &zb, NULL,
109 td->td_arg);
110 }
111 return (0);
112}
113
114static void
115traverse_zil(traverse_data_t *td, zil_header_t *zh)
116{
117 uint64_t claim_txg = zh->zh_claim_txg;
118 zilog_t *zilog;
119
120 /*
121 * We only want to visit blocks that have been claimed but not yet
122 * replayed; plus, in read-only mode, blocks that are already stable.
123 */
124 if (claim_txg == 0 && spa_writeable(td->td_spa))
125 return;
126
127 zilog = zil_alloc(spa_get_dsl(td->td_spa)->dp_meta_objset, zh);
128
129 (void) zil_parse(zilog, traverse_zil_block, traverse_zil_record, td,
130 claim_txg);
131
132 zil_free(zilog);
133}
134
135typedef enum resume_skip {
136 RESUME_SKIP_ALL,
137 RESUME_SKIP_NONE,
138 RESUME_SKIP_CHILDREN
139} resume_skip_t;
140
141/*
142 * Returns RESUME_SKIP_ALL if td indicates that we are resuming a traversal and
143 * the block indicated by zb does not need to be visited at all. Returns
144 * RESUME_SKIP_CHILDREN if we are resuming a post traversal and we reach the
145 * resume point. This indicates that this block should be visited but not its
146 * children (since they must have been visited in a previous traversal).
147 * Otherwise returns RESUME_SKIP_NONE.
148 */
149static resume_skip_t
150resume_skip_check(traverse_data_t *td, const dnode_phys_t *dnp,
151 const zbookmark_t *zb)
152{
153 if (td->td_resume != NULL && !ZB_IS_ZERO(td->td_resume)) {
154 /*
155 * If we already visited this bp & everything below,
156 * don't bother doing it again.
157 */
158 if (zbookmark_is_before(dnp, zb, td->td_resume))
159 return (RESUME_SKIP_ALL);
160
161 /*
162 * If we found the block we're trying to resume from, zero
163 * the bookmark out to indicate that we have resumed.
164 */
165 ASSERT3U(zb->zb_object, <=, td->td_resume->zb_object);
166 if (bcmp(zb, td->td_resume, sizeof (*zb)) == 0) {
167 bzero(td->td_resume, sizeof (*zb));
168 if (td->td_flags & TRAVERSE_POST)
169 return (RESUME_SKIP_CHILDREN);
170 }
171 }
172 return (RESUME_SKIP_NONE);
173}
174
175static void
176traverse_pause(traverse_data_t *td, const zbookmark_t *zb)
177{
178 ASSERT(td->td_resume != NULL);
179 ASSERT0(zb->zb_level);
180 bcopy(zb, td->td_resume, sizeof (*td->td_resume));
181}
182
183static void
184traverse_prefetch_metadata(traverse_data_t *td,
185 arc_buf_t *pbuf, const blkptr_t *bp, const zbookmark_t *zb)
186{
187 uint32_t flags = ARC_NOWAIT | ARC_PREFETCH;
188
189 if (!(td->td_flags & TRAVERSE_PREFETCH_METADATA))
190 return;
191 /*
192 * If we are in the process of resuming, don't prefetch, because
193 * some children will not be needed (and in fact may have already
194 * been freed).
195 */
196 if (td->td_resume != NULL && !ZB_IS_ZERO(td->td_resume))
197 return;
198 if (BP_IS_HOLE(bp) || bp->blk_birth <= td->td_min_txg)
199 return;
200 if (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_DNODE)
201 return;
202
203 (void) arc_read(NULL, td->td_spa, bp,
204 pbuf, NULL, NULL, ZIO_PRIORITY_ASYNC_READ,
205 ZIO_FLAG_CANFAIL, &flags, zb);
206}
207
208static int
209traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp,
133 arc_buf_t *pbuf, blkptr_t *bp, const zbookmark_t *zb)
210 arc_buf_t *pbuf, const blkptr_t *bp, const zbookmark_t *zb)
211{
212 zbookmark_t czb;
213 int err = 0, lasterr = 0;
214 arc_buf_t *buf = NULL;
215 prefetch_data_t *pd = td->td_pfd;
216 boolean_t hard = td->td_flags & TRAVERSE_HARD;
217 boolean_t pause = B_FALSE;
218
141 if (bp->blk_birth == 0) {
219 switch (resume_skip_check(td, dnp, zb)) {
220 case RESUME_SKIP_ALL:
221 return (0);
222 case RESUME_SKIP_CHILDREN:
223 goto post;
224 case RESUME_SKIP_NONE:
225 break;
226 default:
227 ASSERT(0);
228 }
229
230 if (BP_IS_HOLE(bp)) {
231 err = td->td_func(td->td_spa, NULL, NULL, pbuf, zb, dnp,
232 td->td_arg);
233 return (err);
234 }
235
236 if (bp->blk_birth <= td->td_min_txg)
237 return (0);
238
239 if (pd && !pd->pd_exited &&
240 ((pd->pd_flags & TRAVERSE_PREFETCH_DATA) ||
241 BP_GET_TYPE(bp) == DMU_OT_DNODE || BP_GET_LEVEL(bp) > 0)) {
242 mutex_enter(&pd->pd_mtx);
243 ASSERT(pd->pd_blks_fetched >= 0);
244 while (pd->pd_blks_fetched == 0 && !pd->pd_exited)
245 cv_wait(&pd->pd_cv, &pd->pd_mtx);
246 pd->pd_blks_fetched--;
247 cv_broadcast(&pd->pd_cv);
248 mutex_exit(&pd->pd_mtx);
249 }
250
251 if (td->td_flags & TRAVERSE_PRE) {
252 err = td->td_func(td->td_spa, NULL, bp, pbuf, zb, dnp,
253 td->td_arg);
254 if (err == TRAVERSE_VISIT_NO_CHILDREN)
255 return (0);
167 if (err)
168 return (err);
256 if (err == ERESTART)
257 pause = B_TRUE; /* handle pausing at a common point */
258 if (err != 0)
259 goto post;
260 }
261
262 if (BP_GET_LEVEL(bp) > 0) {
263 uint32_t flags = ARC_WAIT;
264 int i;
265 blkptr_t *cbp;
266 int epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT;
267
268 err = dsl_read(NULL, td->td_spa, bp, pbuf,
269 arc_getbuf_func, &buf,
270 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
271 if (err)
272 return (err);
273 cbp = buf->b_data;
274
275 for (i = 0; i < epb; i++) {
276 SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object,
277 zb->zb_level - 1,
278 zb->zb_blkid * epb + i);
279 traverse_prefetch_metadata(td, buf, &cbp[i], &czb);
280 }
281
282 /* recursively visitbp() blocks below this */
184 cbp = buf->b_data;
185 for (i = 0; i < epb; i++, cbp++) {
283 for (i = 0; i < epb; i++) {
284 SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object,
285 zb->zb_level - 1,
286 zb->zb_blkid * epb + i);
189 err = traverse_visitbp(td, dnp, buf, cbp, &czb);
287 err = traverse_visitbp(td, dnp, buf, &cbp[i], &czb);
288 if (err) {
289 if (!hard)
290 break;
291 lasterr = err;
292 }
293 }
294 } else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) {
295 uint32_t flags = ARC_WAIT;
296 int i;
297 int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT;
298
299 err = dsl_read(NULL, td->td_spa, bp, pbuf,
300 arc_getbuf_func, &buf,
301 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
302 if (err)
303 return (err);
304 dnp = buf->b_data;
305
306 for (i = 0; i < epb; i++) {
307 prefetch_dnode_metadata(td, &dnp[i], buf, zb->zb_objset,
308 zb->zb_blkid * epb + i);
309 }
310
311 /* recursively visitbp() blocks below this */
208 dnp = buf->b_data;
209 for (i = 0; i < epb; i++, dnp++) {
210 err = traverse_dnode(td, dnp, buf, zb->zb_objset,
312 for (i = 0; i < epb; i++) {
313 err = traverse_dnode(td, &dnp[i], buf, zb->zb_objset,
314 zb->zb_blkid * epb + i);
315 if (err) {
316 if (!hard)
317 break;
318 lasterr = err;
319 }
320 }
321 } else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) {
322 uint32_t flags = ARC_WAIT;
323 objset_phys_t *osp;
324 dnode_phys_t *dnp;
325
326 err = dsl_read_nolock(NULL, td->td_spa, bp,
327 arc_getbuf_func, &buf,
328 ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb);
329 if (err)
330 return (err);
331
332 osp = buf->b_data;
333 dnp = &osp->os_meta_dnode;
334 prefetch_dnode_metadata(td, dnp, buf, zb->zb_objset,
335 DMU_META_DNODE_OBJECT);
336 if (arc_buf_size(buf) >= sizeof (objset_phys_t)) {
337 prefetch_dnode_metadata(td, &osp->os_userused_dnode,
338 buf, zb->zb_objset, DMU_USERUSED_OBJECT);
339 prefetch_dnode_metadata(td, &osp->os_groupused_dnode,
340 buf, zb->zb_objset, DMU_USERUSED_OBJECT);
341 }
342
343 err = traverse_dnode(td, dnp, buf, zb->zb_objset,
344 DMU_META_DNODE_OBJECT);
345 if (err && hard) {
346 lasterr = err;
347 err = 0;
348 }
349 if (err == 0 && arc_buf_size(buf) >= sizeof (objset_phys_t)) {
350 dnp = &osp->os_userused_dnode;
351 err = traverse_dnode(td, dnp, buf, zb->zb_objset,
352 DMU_USERUSED_OBJECT);
353 }
354 if (err && hard) {
355 lasterr = err;
356 err = 0;
357 }
358 if (err == 0 && arc_buf_size(buf) >= sizeof (objset_phys_t)) {
359 dnp = &osp->os_groupused_dnode;
360 err = traverse_dnode(td, dnp, buf, zb->zb_objset,
361 DMU_GROUPUSED_OBJECT);
362 }
363 }
364
365 if (buf)
366 (void) arc_buf_remove_ref(buf, &buf);
367
368post:
369 if (err == 0 && lasterr == 0 && (td->td_flags & TRAVERSE_POST)) {
370 err = td->td_func(td->td_spa, NULL, bp, pbuf, zb, dnp,
371 td->td_arg);
372 if (err == ERESTART)
373 pause = B_TRUE;
374 }
375
376 if (pause && td->td_resume != NULL) {
377 ASSERT3U(err, ==, ERESTART);
378 ASSERT(!hard);
379 traverse_pause(td, zb);
380 }
381
382 return (err != 0 ? err : lasterr);
383}
384
385static void
386prefetch_dnode_metadata(traverse_data_t *td, const dnode_phys_t *dnp,
387 arc_buf_t *buf, uint64_t objset, uint64_t object)
388{
389 int j;
390 zbookmark_t czb;
391
392 for (j = 0; j < dnp->dn_nblkptr; j++) {
393 SET_BOOKMARK(&czb, objset, object, dnp->dn_nlevels - 1, j);
394 traverse_prefetch_metadata(td, buf, &dnp->dn_blkptr[j], &czb);
395 }
396
397 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
398 SET_BOOKMARK(&czb, objset, object, 0, DMU_SPILL_BLKID);
399 traverse_prefetch_metadata(td, buf, &dnp->dn_spill, &czb);
400 }
401}
402
403static int
404traverse_dnode(traverse_data_t *td, const dnode_phys_t *dnp,
405 arc_buf_t *buf, uint64_t objset, uint64_t object)
406{
407 int j, err = 0, lasterr = 0;
408 zbookmark_t czb;
409 boolean_t hard = (td->td_flags & TRAVERSE_HARD);
410
411 for (j = 0; j < dnp->dn_nblkptr; j++) {
412 SET_BOOKMARK(&czb, objset, object, dnp->dn_nlevels - 1, j);
274 err = traverse_visitbp(td, dnp, buf,
275 (blkptr_t *)&dnp->dn_blkptr[j], &czb);
413 err = traverse_visitbp(td, dnp, buf, &dnp->dn_blkptr[j], &czb);
414 if (err) {
415 if (!hard)
416 break;
417 lasterr = err;
418 }
419 }
420
421 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
284 SET_BOOKMARK(&czb, objset,
285 object, 0, DMU_SPILL_BLKID);
286 err = traverse_visitbp(td, dnp, buf,
287 (blkptr_t *)&dnp->dn_spill, &czb);
422 SET_BOOKMARK(&czb, objset, object, 0, DMU_SPILL_BLKID);
423 err = traverse_visitbp(td, dnp, buf, &dnp->dn_spill, &czb);
424 if (err) {
425 if (!hard)
426 return (err);
427 lasterr = err;
428 }
429 }
430 return (err != 0 ? err : lasterr);
431}
432
433/* ARGSUSED */
434static int
435traverse_prefetcher(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
436 arc_buf_t *pbuf, const zbookmark_t *zb, const dnode_phys_t *dnp,
437 void *arg)
438{
439 prefetch_data_t *pfd = arg;
440 uint32_t aflags = ARC_NOWAIT | ARC_PREFETCH;
441
442 ASSERT(pfd->pd_blks_fetched >= 0);
443 if (pfd->pd_cancel)
444 return (EINTR);
445
446 if (bp == NULL || !((pfd->pd_flags & TRAVERSE_PREFETCH_DATA) ||
447 BP_GET_TYPE(bp) == DMU_OT_DNODE || BP_GET_LEVEL(bp) > 0) ||
448 BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG)
449 return (0);
450
451 mutex_enter(&pfd->pd_mtx);
452 while (!pfd->pd_cancel && pfd->pd_blks_fetched >= pfd->pd_blks_max)
453 cv_wait(&pfd->pd_cv, &pfd->pd_mtx);
454 pfd->pd_blks_fetched++;
455 cv_broadcast(&pfd->pd_cv);
456 mutex_exit(&pfd->pd_mtx);
457
458 (void) dsl_read(NULL, spa, bp, pbuf, NULL, NULL,
459 ZIO_PRIORITY_ASYNC_READ,
460 ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE,
461 &aflags, zb);
462
463 return (0);
464}
465
466static void
467traverse_prefetch_thread(void *arg)
468{
469 traverse_data_t *td_main = arg;
470 traverse_data_t td = *td_main;
471 zbookmark_t czb;
472
473 td.td_func = traverse_prefetcher;
474 td.td_arg = td_main->td_pfd;
475 td.td_pfd = NULL;
476
477 SET_BOOKMARK(&czb, td.td_objset,
478 ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
479 (void) traverse_visitbp(&td, NULL, NULL, td.td_rootbp, &czb);
480
481 mutex_enter(&td_main->td_pfd->pd_mtx);
482 td_main->td_pfd->pd_exited = B_TRUE;
483 cv_broadcast(&td_main->td_pfd->pd_cv);
484 mutex_exit(&td_main->td_pfd->pd_mtx);
485}
486
487/*
488 * NB: dataset must not be changing on-disk (eg, is a snapshot or we are
489 * in syncing context).
490 */
491static int
356traverse_impl(spa_t *spa, dsl_dataset_t *ds, blkptr_t *rootbp,
357 uint64_t txg_start, int flags, blkptr_cb_t func, void *arg)
492traverse_impl(spa_t *spa, dsl_dataset_t *ds, uint64_t objset, blkptr_t *rootbp,
493 uint64_t txg_start, zbookmark_t *resume, int flags,
494 blkptr_cb_t func, void *arg)
495{
496 traverse_data_t td;
497 prefetch_data_t pd = { 0 };
498 zbookmark_t czb;
499 int err;
500
501 ASSERT(ds == NULL || objset == ds->ds_object);
502 ASSERT(!(flags & TRAVERSE_PRE) || !(flags & TRAVERSE_POST));
503
504 /*
505 * The data prefetching mechanism (the prefetch thread) is incompatible
506 * with resuming from a bookmark.
507 */
508 ASSERT(resume == NULL || !(flags & TRAVERSE_PREFETCH_DATA));
509
510 td.td_spa = spa;
365 td.td_objset = ds ? ds->ds_object : 0;
511 td.td_objset = objset;
512 td.td_rootbp = rootbp;
513 td.td_min_txg = txg_start;
514 td.td_resume = resume;
515 td.td_func = func;
516 td.td_arg = arg;
517 td.td_pfd = &pd;
518 td.td_flags = flags;
519
520 pd.pd_blks_max = zfs_pd_blks_max;
521 pd.pd_flags = flags;
522 mutex_init(&pd.pd_mtx, NULL, MUTEX_DEFAULT, NULL);
523 cv_init(&pd.pd_cv, NULL, CV_DEFAULT, NULL);
524
525 /* See comment on ZIL traversal in dsl_scan_visitds. */
526 if (ds != NULL && !dsl_dataset_is_snapshot(ds)) {
527 objset_t *os;
528
529 err = dmu_objset_from_ds(ds, &os);
530 if (err)
531 return (err);
532
533 traverse_zil(&td, &os->os_zil_header);
534 }
535
389 if (!(flags & TRAVERSE_PREFETCH) ||
536 if (!(flags & TRAVERSE_PREFETCH_DATA) ||
537 0 == taskq_dispatch(system_taskq, traverse_prefetch_thread,
538 &td, TQ_NOQUEUE))
539 pd.pd_exited = B_TRUE;
540
541 SET_BOOKMARK(&czb, td.td_objset,
542 ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID);
543 err = traverse_visitbp(&td, NULL, NULL, rootbp, &czb);
544
545 mutex_enter(&pd.pd_mtx);
546 pd.pd_cancel = B_TRUE;
547 cv_broadcast(&pd.pd_cv);
548 while (!pd.pd_exited)
549 cv_wait(&pd.pd_cv, &pd.pd_mtx);
550 mutex_exit(&pd.pd_mtx);
551
552 mutex_destroy(&pd.pd_mtx);
553 cv_destroy(&pd.pd_cv);
554
555 return (err);
556}
557
558/*
559 * NB: dataset must not be changing on-disk (eg, is a snapshot or we are
560 * in syncing context).
561 */
562int
563traverse_dataset(dsl_dataset_t *ds, uint64_t txg_start, int flags,
564 blkptr_cb_t func, void *arg)
565{
419 return (traverse_impl(ds->ds_dir->dd_pool->dp_spa, ds,
420 &ds->ds_phys->ds_bp, txg_start, flags, func, arg));
566 return (traverse_impl(ds->ds_dir->dd_pool->dp_spa, ds, ds->ds_object,
567 &ds->ds_phys->ds_bp, txg_start, NULL, flags, func, arg));
568}
569
570int
571traverse_dataset_destroyed(spa_t *spa, blkptr_t *blkptr,
572 uint64_t txg_start, zbookmark_t *resume, int flags,
573 blkptr_cb_t func, void *arg)
574{
575 return (traverse_impl(spa, NULL, ZB_DESTROYED_OBJSET,
576 blkptr, txg_start, resume, flags, func, arg));
577}
578
579/*
580 * NB: pool must not be changing on-disk (eg, from zdb or sync context).
581 */
582int
583traverse_pool(spa_t *spa, uint64_t txg_start, int flags,
584 blkptr_cb_t func, void *arg)
585{
586 int err, lasterr = 0;
587 uint64_t obj;
588 dsl_pool_t *dp = spa_get_dsl(spa);
589 objset_t *mos = dp->dp_meta_objset;
590 boolean_t hard = (flags & TRAVERSE_HARD);
591
592 /* visit the MOS */
437 err = traverse_impl(spa, NULL, spa_get_rootblkptr(spa),
438 txg_start, flags, func, arg);
593 err = traverse_impl(spa, NULL, 0, spa_get_rootblkptr(spa),
594 txg_start, NULL, flags, func, arg);
595 if (err)
596 return (err);
597
598 /* visit each dataset */
599 for (obj = 1; err == 0 || (err != ESRCH && hard);
600 err = dmu_object_next(mos, &obj, FALSE, txg_start)) {
601 dmu_object_info_t doi;
602
603 err = dmu_object_info(mos, obj, &doi);
604 if (err) {
605 if (!hard)
606 return (err);
607 lasterr = err;
608 continue;
609 }
610
611 if (doi.doi_type == DMU_OT_DSL_DATASET) {
612 dsl_dataset_t *ds;
613 uint64_t txg = txg_start;
614
615 rw_enter(&dp->dp_config_rwlock, RW_READER);
616 err = dsl_dataset_hold_obj(dp, obj, FTAG, &ds);
617 rw_exit(&dp->dp_config_rwlock);
618 if (err) {
619 if (!hard)
620 return (err);
621 lasterr = err;
622 continue;
623 }
624 if (ds->ds_phys->ds_prev_snap_txg > txg)
625 txg = ds->ds_phys->ds_prev_snap_txg;
626 err = traverse_dataset(ds, txg, flags, func, arg);
627 dsl_dataset_rele(ds, FTAG);
628 if (err) {
629 if (!hard)
630 return (err);
631 lasterr = err;
632 }
633 }
634 }
635 if (err == ESRCH)
636 err = 0;
637 return (err != 0 ? err : lasterr);
638}