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.
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.
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]
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2011 by Delphix. All rights reserved.
26 #include <sys/dmu_objset.h>
27 #include <sys/dsl_dataset.h>
28 #include <sys/dsl_dir.h>
29 #include <sys/dsl_prop.h>
30 #include <sys/dsl_synctask.h>
31 #include <sys/dmu_traverse.h>
32 #include <sys/dmu_tx.h>
36 #include <sys/unique.h>
37 #include <sys/zfs_context.h>
38 #include <sys/zfs_ioctl.h>
40 #include <sys/zfs_znode.h>
41 #include <sys/zfs_onexit.h>
43 #include <sys/dsl_scan.h>
44 #include <sys/dsl_deadlist.h>
46 static char *dsl_reaper = "the grim reaper";
48 static dsl_checkfunc_t dsl_dataset_destroy_begin_check;
49 static dsl_syncfunc_t dsl_dataset_destroy_begin_sync;
50 static dsl_syncfunc_t dsl_dataset_set_reservation_sync;
52 #define SWITCH64(x, y) \
54 uint64_t __tmp = (x); \
59 #define DS_REF_MAX (1ULL << 62)
61 #define DSL_DEADLIST_BLOCKSIZE SPA_MAXBLOCKSIZE
63 #define DSL_DATASET_IS_DESTROYED(ds) ((ds)->ds_owner == dsl_reaper)
67 * Figure out how much of this delta should be propogated to the dsl_dir
68 * layer. If there's a refreservation, that space has already been
69 * partially accounted for in our ancestors.
72 parent_delta(dsl_dataset_t *ds, int64_t delta)
74 uint64_t old_bytes, new_bytes;
76 if (ds->ds_reserved == 0)
79 old_bytes = MAX(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
80 new_bytes = MAX(ds->ds_phys->ds_unique_bytes + delta, ds->ds_reserved);
82 ASSERT3U(ABS((int64_t)(new_bytes - old_bytes)), <=, ABS(delta));
83 return (new_bytes - old_bytes);
87 dsl_dataset_block_born(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx)
89 int used, compressed, uncompressed;
92 used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
93 compressed = BP_GET_PSIZE(bp);
94 uncompressed = BP_GET_UCSIZE(bp);
96 dprintf_bp(bp, "ds=%p", ds);
98 ASSERT(dmu_tx_is_syncing(tx));
99 /* It could have been compressed away to nothing */
102 ASSERT(BP_GET_TYPE(bp) != DMU_OT_NONE);
103 ASSERT3U(BP_GET_TYPE(bp), <, DMU_OT_NUMTYPES);
106 * Account for the meta-objset space in its placeholder
109 ASSERT3U(compressed, ==, uncompressed); /* it's all metadata */
110 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD,
111 used, compressed, uncompressed, tx);
112 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx);
115 dmu_buf_will_dirty(ds->ds_dbuf, tx);
117 mutex_enter(&ds->ds_dir->dd_lock);
118 mutex_enter(&ds->ds_lock);
119 delta = parent_delta(ds, used);
120 ds->ds_phys->ds_used_bytes += used;
121 ds->ds_phys->ds_compressed_bytes += compressed;
122 ds->ds_phys->ds_uncompressed_bytes += uncompressed;
123 ds->ds_phys->ds_unique_bytes += used;
124 mutex_exit(&ds->ds_lock);
125 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta,
126 compressed, uncompressed, tx);
127 dsl_dir_transfer_space(ds->ds_dir, used - delta,
128 DD_USED_REFRSRV, DD_USED_HEAD, tx);
129 mutex_exit(&ds->ds_dir->dd_lock);
133 dsl_dataset_block_kill(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx,
136 int used, compressed, uncompressed;
141 ASSERT(dmu_tx_is_syncing(tx));
142 ASSERT(bp->blk_birth <= tx->tx_txg);
144 used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
145 compressed = BP_GET_PSIZE(bp);
146 uncompressed = BP_GET_UCSIZE(bp);
151 * Account for the meta-objset space in its placeholder
154 dsl_free(tx->tx_pool, tx->tx_txg, bp);
156 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD,
157 -used, -compressed, -uncompressed, tx);
158 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx);
161 ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool);
163 ASSERT(!dsl_dataset_is_snapshot(ds));
164 dmu_buf_will_dirty(ds->ds_dbuf, tx);
166 if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) {
169 dprintf_bp(bp, "freeing ds=%llu", ds->ds_object);
170 dsl_free(tx->tx_pool, tx->tx_txg, bp);
172 mutex_enter(&ds->ds_dir->dd_lock);
173 mutex_enter(&ds->ds_lock);
174 ASSERT(ds->ds_phys->ds_unique_bytes >= used ||
175 !DS_UNIQUE_IS_ACCURATE(ds));
176 delta = parent_delta(ds, -used);
177 ds->ds_phys->ds_unique_bytes -= used;
178 mutex_exit(&ds->ds_lock);
179 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
180 delta, -compressed, -uncompressed, tx);
181 dsl_dir_transfer_space(ds->ds_dir, -used - delta,
182 DD_USED_REFRSRV, DD_USED_HEAD, tx);
183 mutex_exit(&ds->ds_dir->dd_lock);
185 dprintf_bp(bp, "putting on dead list: %s", "");
188 * We are here as part of zio's write done callback,
189 * which means we're a zio interrupt thread. We can't
190 * call dsl_deadlist_insert() now because it may block
191 * waiting for I/O. Instead, put bp on the deferred
192 * queue and let dsl_pool_sync() finish the job.
194 bplist_append(&ds->ds_pending_deadlist, bp);
196 dsl_deadlist_insert(&ds->ds_deadlist, bp, tx);
198 ASSERT3U(ds->ds_prev->ds_object, ==,
199 ds->ds_phys->ds_prev_snap_obj);
200 ASSERT(ds->ds_prev->ds_phys->ds_num_children > 0);
201 /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */
202 if (ds->ds_prev->ds_phys->ds_next_snap_obj ==
203 ds->ds_object && bp->blk_birth >
204 ds->ds_prev->ds_phys->ds_prev_snap_txg) {
205 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
206 mutex_enter(&ds->ds_prev->ds_lock);
207 ds->ds_prev->ds_phys->ds_unique_bytes += used;
208 mutex_exit(&ds->ds_prev->ds_lock);
210 if (bp->blk_birth > ds->ds_dir->dd_origin_txg) {
211 dsl_dir_transfer_space(ds->ds_dir, used,
212 DD_USED_HEAD, DD_USED_SNAP, tx);
215 mutex_enter(&ds->ds_lock);
216 ASSERT3U(ds->ds_phys->ds_used_bytes, >=, used);
217 ds->ds_phys->ds_used_bytes -= used;
218 ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed);
219 ds->ds_phys->ds_compressed_bytes -= compressed;
220 ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed);
221 ds->ds_phys->ds_uncompressed_bytes -= uncompressed;
222 mutex_exit(&ds->ds_lock);
228 dsl_dataset_prev_snap_txg(dsl_dataset_t *ds)
230 uint64_t trysnap = 0;
235 * The snapshot creation could fail, but that would cause an
236 * incorrect FALSE return, which would only result in an
237 * overestimation of the amount of space that an operation would
238 * consume, which is OK.
240 * There's also a small window where we could miss a pending
241 * snapshot, because we could set the sync task in the quiescing
242 * phase. So this should only be used as a guess.
244 if (ds->ds_trysnap_txg >
245 spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa))
246 trysnap = ds->ds_trysnap_txg;
247 return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap));
251 dsl_dataset_block_freeable(dsl_dataset_t *ds, const blkptr_t *bp,
254 if (blk_birth <= dsl_dataset_prev_snap_txg(ds))
257 ddt_prefetch(dsl_dataset_get_spa(ds), bp);
264 dsl_dataset_evict(dmu_buf_t *db, void *dsv)
266 dsl_dataset_t *ds = dsv;
268 ASSERT(ds->ds_owner == NULL || DSL_DATASET_IS_DESTROYED(ds));
270 unique_remove(ds->ds_fsid_guid);
272 if (ds->ds_objset != NULL)
273 dmu_objset_evict(ds->ds_objset);
276 dsl_dataset_drop_ref(ds->ds_prev, ds);
280 bplist_destroy(&ds->ds_pending_deadlist);
282 dsl_deadlist_close(&ds->ds_deadlist);
284 ASSERT(ds->ds_deadlist.dl_dbuf == NULL);
285 ASSERT(!ds->ds_deadlist.dl_oldfmt);
288 dsl_dir_close(ds->ds_dir, ds);
290 ASSERT(!list_link_active(&ds->ds_synced_link));
292 mutex_destroy(&ds->ds_lock);
293 mutex_destroy(&ds->ds_recvlock);
294 mutex_destroy(&ds->ds_opening_lock);
295 rw_destroy(&ds->ds_rwlock);
296 cv_destroy(&ds->ds_exclusive_cv);
298 kmem_free(ds, sizeof (dsl_dataset_t));
302 dsl_dataset_get_snapname(dsl_dataset_t *ds)
304 dsl_dataset_phys_t *headphys;
307 dsl_pool_t *dp = ds->ds_dir->dd_pool;
308 objset_t *mos = dp->dp_meta_objset;
310 if (ds->ds_snapname[0])
312 if (ds->ds_phys->ds_next_snap_obj == 0)
315 err = dmu_bonus_hold(mos, ds->ds_dir->dd_phys->dd_head_dataset_obj,
319 headphys = headdbuf->db_data;
320 err = zap_value_search(dp->dp_meta_objset,
321 headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname);
322 dmu_buf_rele(headdbuf, FTAG);
327 dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name, uint64_t *value)
329 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
330 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
334 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
339 err = zap_lookup_norm(mos, snapobj, name, 8, 1,
340 value, mt, NULL, 0, NULL);
341 if (err == ENOTSUP && mt == MT_FIRST)
342 err = zap_lookup(mos, snapobj, name, 8, 1, value);
347 dsl_dataset_snap_remove(dsl_dataset_t *ds, char *name, dmu_tx_t *tx)
349 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
350 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
354 dsl_dir_snap_cmtime_update(ds->ds_dir);
356 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
361 err = zap_remove_norm(mos, snapobj, name, mt, tx);
362 if (err == ENOTSUP && mt == MT_FIRST)
363 err = zap_remove(mos, snapobj, name, tx);
368 dsl_dataset_get_ref(dsl_pool_t *dp, uint64_t dsobj, void *tag,
371 objset_t *mos = dp->dp_meta_objset;
375 dmu_object_info_t doi;
377 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) ||
378 dsl_pool_sync_context(dp));
380 err = dmu_bonus_hold(mos, dsobj, tag, &dbuf);
384 /* Make sure dsobj has the correct object type. */
385 dmu_object_info_from_db(dbuf, &doi);
386 if (doi.doi_type != DMU_OT_DSL_DATASET)
389 ds = dmu_buf_get_user(dbuf);
391 dsl_dataset_t *winner = NULL;
393 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_PUSHPAGE);
395 ds->ds_object = dsobj;
396 ds->ds_phys = dbuf->db_data;
397 list_link_init(&ds->ds_synced_link);
399 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL);
400 mutex_init(&ds->ds_recvlock, NULL, MUTEX_DEFAULT, NULL);
401 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL);
402 rw_init(&ds->ds_rwlock, NULL, RW_DEFAULT, NULL);
403 cv_init(&ds->ds_exclusive_cv, NULL, CV_DEFAULT, NULL);
405 bplist_create(&ds->ds_pending_deadlist);
406 dsl_deadlist_open(&ds->ds_deadlist,
407 mos, ds->ds_phys->ds_deadlist_obj);
410 err = dsl_dir_open_obj(dp,
411 ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir);
414 mutex_destroy(&ds->ds_lock);
415 mutex_destroy(&ds->ds_recvlock);
416 mutex_destroy(&ds->ds_opening_lock);
417 rw_destroy(&ds->ds_rwlock);
418 cv_destroy(&ds->ds_exclusive_cv);
419 bplist_destroy(&ds->ds_pending_deadlist);
420 dsl_deadlist_close(&ds->ds_deadlist);
421 kmem_free(ds, sizeof (dsl_dataset_t));
422 dmu_buf_rele(dbuf, tag);
426 if (!dsl_dataset_is_snapshot(ds)) {
427 ds->ds_snapname[0] = '\0';
428 if (ds->ds_phys->ds_prev_snap_obj) {
429 err = dsl_dataset_get_ref(dp,
430 ds->ds_phys->ds_prev_snap_obj,
434 if (zfs_flags & ZFS_DEBUG_SNAPNAMES)
435 err = dsl_dataset_get_snapname(ds);
436 if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) {
438 ds->ds_dir->dd_pool->dp_meta_objset,
439 ds->ds_phys->ds_userrefs_obj,
444 if (err == 0 && !dsl_dataset_is_snapshot(ds)) {
446 * In sync context, we're called with either no lock
447 * or with the write lock. If we're not syncing,
448 * we're always called with the read lock held.
450 boolean_t need_lock =
451 !RW_WRITE_HELD(&dp->dp_config_rwlock) &&
452 dsl_pool_sync_context(dp);
455 rw_enter(&dp->dp_config_rwlock, RW_READER);
457 err = dsl_prop_get_ds(ds,
458 "refreservation", sizeof (uint64_t), 1,
459 &ds->ds_reserved, NULL);
461 err = dsl_prop_get_ds(ds,
462 "refquota", sizeof (uint64_t), 1,
463 &ds->ds_quota, NULL);
467 rw_exit(&dp->dp_config_rwlock);
469 ds->ds_reserved = ds->ds_quota = 0;
473 winner = dmu_buf_set_user_ie(dbuf, ds, &ds->ds_phys,
477 bplist_destroy(&ds->ds_pending_deadlist);
478 dsl_deadlist_close(&ds->ds_deadlist);
480 dsl_dataset_drop_ref(ds->ds_prev, ds);
481 dsl_dir_close(ds->ds_dir, ds);
482 mutex_destroy(&ds->ds_lock);
483 mutex_destroy(&ds->ds_recvlock);
484 mutex_destroy(&ds->ds_opening_lock);
485 rw_destroy(&ds->ds_rwlock);
486 cv_destroy(&ds->ds_exclusive_cv);
487 kmem_free(ds, sizeof (dsl_dataset_t));
489 dmu_buf_rele(dbuf, tag);
495 unique_insert(ds->ds_phys->ds_fsid_guid);
498 ASSERT3P(ds->ds_dbuf, ==, dbuf);
499 ASSERT3P(ds->ds_phys, ==, dbuf->db_data);
500 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 ||
501 spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN ||
502 dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap);
503 mutex_enter(&ds->ds_lock);
504 if (!dsl_pool_sync_context(dp) && DSL_DATASET_IS_DESTROYED(ds)) {
505 mutex_exit(&ds->ds_lock);
506 dmu_buf_rele(ds->ds_dbuf, tag);
509 mutex_exit(&ds->ds_lock);
515 dsl_dataset_hold_ref(dsl_dataset_t *ds, void *tag)
517 dsl_pool_t *dp = ds->ds_dir->dd_pool;
520 * In syncing context we don't want the rwlock lock: there
521 * may be an existing writer waiting for sync phase to
522 * finish. We don't need to worry about such writers, since
523 * sync phase is single-threaded, so the writer can't be
524 * doing anything while we are active.
526 if (dsl_pool_sync_context(dp)) {
527 ASSERT(!DSL_DATASET_IS_DESTROYED(ds));
532 * Normal users will hold the ds_rwlock as a READER until they
533 * are finished (i.e., call dsl_dataset_rele()). "Owners" will
534 * drop their READER lock after they set the ds_owner field.
536 * If the dataset is being destroyed, the destroy thread will
537 * obtain a WRITER lock for exclusive access after it's done its
538 * open-context work and then change the ds_owner to
539 * dsl_reaper once destruction is assured. So threads
540 * may block here temporarily, until the "destructability" of
541 * the dataset is determined.
543 ASSERT(!RW_WRITE_HELD(&dp->dp_config_rwlock));
544 mutex_enter(&ds->ds_lock);
545 while (!rw_tryenter(&ds->ds_rwlock, RW_READER)) {
546 rw_exit(&dp->dp_config_rwlock);
547 cv_wait(&ds->ds_exclusive_cv, &ds->ds_lock);
548 if (DSL_DATASET_IS_DESTROYED(ds)) {
549 mutex_exit(&ds->ds_lock);
550 dsl_dataset_drop_ref(ds, tag);
551 rw_enter(&dp->dp_config_rwlock, RW_READER);
555 * The dp_config_rwlock lives above the ds_lock. And
556 * we need to check DSL_DATASET_IS_DESTROYED() while
557 * holding the ds_lock, so we have to drop and reacquire
560 mutex_exit(&ds->ds_lock);
561 rw_enter(&dp->dp_config_rwlock, RW_READER);
562 mutex_enter(&ds->ds_lock);
564 mutex_exit(&ds->ds_lock);
569 dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag,
572 int err = dsl_dataset_get_ref(dp, dsobj, tag, dsp);
576 return (dsl_dataset_hold_ref(*dsp, tag));
580 dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj, boolean_t inconsistentok,
581 void *tag, dsl_dataset_t **dsp)
583 int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp);
586 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) {
587 dsl_dataset_rele(*dsp, tag);
595 dsl_dataset_hold(const char *name, void *tag, dsl_dataset_t **dsp)
599 const char *snapname;
603 err = dsl_dir_open_spa(NULL, name, FTAG, &dd, &snapname);
608 obj = dd->dd_phys->dd_head_dataset_obj;
609 rw_enter(&dp->dp_config_rwlock, RW_READER);
611 err = dsl_dataset_get_ref(dp, obj, tag, dsp);
617 err = dsl_dataset_hold_ref(*dsp, tag);
619 /* we may be looking for a snapshot */
620 if (err == 0 && snapname != NULL) {
621 dsl_dataset_t *ds = NULL;
623 if (*snapname++ != '@') {
624 dsl_dataset_rele(*dsp, tag);
629 dprintf("looking for snapshot '%s'\n", snapname);
630 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj);
632 err = dsl_dataset_get_ref(dp, obj, tag, &ds);
633 dsl_dataset_rele(*dsp, tag);
635 ASSERT3U((err == 0), ==, (ds != NULL));
638 mutex_enter(&ds->ds_lock);
639 if (ds->ds_snapname[0] == 0)
640 (void) strlcpy(ds->ds_snapname, snapname,
641 sizeof (ds->ds_snapname));
642 mutex_exit(&ds->ds_lock);
643 err = dsl_dataset_hold_ref(ds, tag);
644 *dsp = err ? NULL : ds;
648 rw_exit(&dp->dp_config_rwlock);
649 dsl_dir_close(dd, FTAG);
654 dsl_dataset_own(const char *name, boolean_t inconsistentok,
655 void *tag, dsl_dataset_t **dsp)
657 int err = dsl_dataset_hold(name, tag, dsp);
660 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) {
661 dsl_dataset_rele(*dsp, tag);
668 dsl_dataset_name(dsl_dataset_t *ds, char *name)
671 (void) strcpy(name, "mos");
673 dsl_dir_name(ds->ds_dir, name);
674 VERIFY(0 == dsl_dataset_get_snapname(ds));
675 if (ds->ds_snapname[0]) {
676 (void) strcat(name, "@");
678 * We use a "recursive" mutex so that we
679 * can call dprintf_ds() with ds_lock held.
681 if (!MUTEX_HELD(&ds->ds_lock)) {
682 mutex_enter(&ds->ds_lock);
683 (void) strcat(name, ds->ds_snapname);
684 mutex_exit(&ds->ds_lock);
686 (void) strcat(name, ds->ds_snapname);
693 dsl_dataset_namelen(dsl_dataset_t *ds)
698 result = 3; /* "mos" */
700 result = dsl_dir_namelen(ds->ds_dir);
701 VERIFY(0 == dsl_dataset_get_snapname(ds));
702 if (ds->ds_snapname[0]) {
703 ++result; /* adding one for the @-sign */
704 if (!MUTEX_HELD(&ds->ds_lock)) {
705 mutex_enter(&ds->ds_lock);
706 result += strlen(ds->ds_snapname);
707 mutex_exit(&ds->ds_lock);
709 result += strlen(ds->ds_snapname);
718 dsl_dataset_drop_ref(dsl_dataset_t *ds, void *tag)
720 dmu_buf_rele(ds->ds_dbuf, tag);
724 dsl_dataset_rele(dsl_dataset_t *ds, void *tag)
726 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) {
727 rw_exit(&ds->ds_rwlock);
729 dsl_dataset_drop_ref(ds, tag);
733 dsl_dataset_disown(dsl_dataset_t *ds, void *tag)
735 ASSERT((ds->ds_owner == tag && ds->ds_dbuf) ||
736 (DSL_DATASET_IS_DESTROYED(ds) && ds->ds_dbuf == NULL));
738 mutex_enter(&ds->ds_lock);
740 if (RW_WRITE_HELD(&ds->ds_rwlock)) {
741 rw_exit(&ds->ds_rwlock);
742 cv_broadcast(&ds->ds_exclusive_cv);
744 mutex_exit(&ds->ds_lock);
746 dsl_dataset_drop_ref(ds, tag);
748 dsl_dataset_evict(NULL, ds);
752 dsl_dataset_tryown(dsl_dataset_t *ds, boolean_t inconsistentok, void *tag)
754 boolean_t gotit = FALSE;
756 mutex_enter(&ds->ds_lock);
757 if (ds->ds_owner == NULL &&
758 (!DS_IS_INCONSISTENT(ds) || inconsistentok)) {
760 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool))
761 rw_exit(&ds->ds_rwlock);
764 mutex_exit(&ds->ds_lock);
769 dsl_dataset_make_exclusive(dsl_dataset_t *ds, void *owner)
771 ASSERT3P(owner, ==, ds->ds_owner);
772 if (!RW_WRITE_HELD(&ds->ds_rwlock))
773 rw_enter(&ds->ds_rwlock, RW_WRITER);
777 dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin,
778 uint64_t flags, dmu_tx_t *tx)
780 dsl_pool_t *dp = dd->dd_pool;
782 dsl_dataset_phys_t *dsphys;
784 objset_t *mos = dp->dp_meta_objset;
787 origin = dp->dp_origin_snap;
789 ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp);
790 ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0);
791 ASSERT(dmu_tx_is_syncing(tx));
792 ASSERT(dd->dd_phys->dd_head_dataset_obj == 0);
794 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
795 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
796 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
797 dmu_buf_will_dirty(dbuf, tx);
798 dsphys = dbuf->db_data;
799 bzero(dsphys, sizeof (dsl_dataset_phys_t));
800 dsphys->ds_dir_obj = dd->dd_object;
801 dsphys->ds_flags = flags;
802 dsphys->ds_fsid_guid = unique_create();
803 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
804 sizeof (dsphys->ds_guid));
805 dsphys->ds_snapnames_zapobj =
806 zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP,
808 dsphys->ds_creation_time = gethrestime_sec();
809 dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg;
811 if (origin == NULL) {
812 dsphys->ds_deadlist_obj = dsl_deadlist_alloc(mos, tx);
816 dsphys->ds_prev_snap_obj = origin->ds_object;
817 dsphys->ds_prev_snap_txg =
818 origin->ds_phys->ds_creation_txg;
819 dsphys->ds_used_bytes =
820 origin->ds_phys->ds_used_bytes;
821 dsphys->ds_compressed_bytes =
822 origin->ds_phys->ds_compressed_bytes;
823 dsphys->ds_uncompressed_bytes =
824 origin->ds_phys->ds_uncompressed_bytes;
825 dsphys->ds_bp = origin->ds_phys->ds_bp;
826 dsphys->ds_flags |= origin->ds_phys->ds_flags;
828 dmu_buf_will_dirty(origin->ds_dbuf, tx);
829 origin->ds_phys->ds_num_children++;
831 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
832 origin->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ohds));
833 dsphys->ds_deadlist_obj = dsl_deadlist_clone(&ohds->ds_deadlist,
834 dsphys->ds_prev_snap_txg, dsphys->ds_prev_snap_obj, tx);
835 dsl_dataset_rele(ohds, FTAG);
837 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) {
838 if (origin->ds_phys->ds_next_clones_obj == 0) {
839 origin->ds_phys->ds_next_clones_obj =
841 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx);
843 VERIFY(0 == zap_add_int(mos,
844 origin->ds_phys->ds_next_clones_obj,
848 dmu_buf_will_dirty(dd->dd_dbuf, tx);
849 dd->dd_phys->dd_origin_obj = origin->ds_object;
850 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
851 if (origin->ds_dir->dd_phys->dd_clones == 0) {
852 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx);
853 origin->ds_dir->dd_phys->dd_clones =
855 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
857 VERIFY3U(0, ==, zap_add_int(mos,
858 origin->ds_dir->dd_phys->dd_clones, dsobj, tx));
862 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
863 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
865 dmu_buf_rele(dbuf, FTAG);
867 dmu_buf_will_dirty(dd->dd_dbuf, tx);
868 dd->dd_phys->dd_head_dataset_obj = dsobj;
874 dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname,
875 dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx)
877 dsl_pool_t *dp = pdd->dd_pool;
878 uint64_t dsobj, ddobj;
881 ASSERT(lastname[0] != '@');
883 ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx);
884 VERIFY(0 == dsl_dir_open_obj(dp, ddobj, lastname, FTAG, &dd));
886 dsobj = dsl_dataset_create_sync_dd(dd, origin, flags, tx);
888 dsl_deleg_set_create_perms(dd, tx, cr);
890 dsl_dir_close(dd, FTAG);
893 * If we are creating a clone, make sure we zero out any stale
894 * data from the origin snapshots zil header.
896 if (origin != NULL) {
900 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
901 VERIFY3U(0, ==, dmu_objset_from_ds(ds, &os));
902 bzero(&os->os_zil_header, sizeof (os->os_zil_header));
903 dsl_dataset_dirty(ds, tx);
904 dsl_dataset_rele(ds, FTAG);
911 * The snapshots must all be in the same pool.
914 dmu_snapshots_destroy_nvl(nvlist_t *snaps, boolean_t defer, char *failed)
917 dsl_sync_task_t *dst;
920 dsl_sync_task_group_t *dstg;
922 pair = nvlist_next_nvpair(snaps, NULL);
926 err = spa_open(nvpair_name(pair), &spa, FTAG);
929 dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
931 for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL;
932 pair = nvlist_next_nvpair(snaps, pair)) {
936 err = dsl_dataset_own(nvpair_name(pair), B_TRUE, dstg, &ds);
938 struct dsl_ds_destroyarg *dsda;
940 dsl_dataset_make_exclusive(ds, dstg);
941 dsda = kmem_zalloc(sizeof (struct dsl_ds_destroyarg),
945 dsl_sync_task_create(dstg, dsl_dataset_destroy_check,
946 dsl_dataset_destroy_sync, dsda, dstg, 0);
947 } else if (err == ENOENT) {
950 (void) strcpy(failed, nvpair_name(pair));
956 err = dsl_sync_task_group_wait(dstg);
958 for (dst = list_head(&dstg->dstg_tasks); dst;
959 dst = list_next(&dstg->dstg_tasks, dst)) {
960 struct dsl_ds_destroyarg *dsda = dst->dst_arg1;
961 dsl_dataset_t *ds = dsda->ds;
964 * Return the file system name that triggered the error
967 dsl_dataset_name(ds, failed);
969 ASSERT3P(dsda->rm_origin, ==, NULL);
970 dsl_dataset_disown(ds, dstg);
971 kmem_free(dsda, sizeof (struct dsl_ds_destroyarg));
974 dsl_sync_task_group_destroy(dstg);
975 spa_close(spa, FTAG);
981 dsl_dataset_might_destroy_origin(dsl_dataset_t *ds)
983 boolean_t might_destroy = B_FALSE;
985 mutex_enter(&ds->ds_lock);
986 if (ds->ds_phys->ds_num_children == 2 && ds->ds_userrefs == 0 &&
987 DS_IS_DEFER_DESTROY(ds))
988 might_destroy = B_TRUE;
989 mutex_exit(&ds->ds_lock);
991 return (might_destroy);
995 * If we're removing a clone, and these three conditions are true:
996 * 1) the clone's origin has no other children
997 * 2) the clone's origin has no user references
998 * 3) the clone's origin has been marked for deferred destruction
999 * Then, prepare to remove the origin as part of this sync task group.
1002 dsl_dataset_origin_rm_prep(struct dsl_ds_destroyarg *dsda, void *tag)
1004 dsl_dataset_t *ds = dsda->ds;
1005 dsl_dataset_t *origin = ds->ds_prev;
1007 if (dsl_dataset_might_destroy_origin(origin)) {
1012 namelen = dsl_dataset_namelen(origin) + 1;
1013 name = kmem_alloc(namelen, KM_SLEEP);
1014 dsl_dataset_name(origin, name);
1016 error = zfs_unmount_snap(name, NULL);
1018 kmem_free(name, namelen);
1022 error = dsl_dataset_own(name, B_TRUE, tag, &origin);
1023 kmem_free(name, namelen);
1026 dsda->rm_origin = origin;
1027 dsl_dataset_make_exclusive(origin, tag);
1034 * ds must be opened as OWNER. On return (whether successful or not),
1035 * ds will be closed and caller can no longer dereference it.
1038 dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer)
1041 dsl_sync_task_group_t *dstg;
1045 struct dsl_ds_destroyarg dsda = { 0 };
1046 dsl_dataset_t *dummy_ds;
1050 if (dsl_dataset_is_snapshot(ds)) {
1051 /* Destroying a snapshot is simpler */
1052 dsl_dataset_make_exclusive(ds, tag);
1055 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
1056 dsl_dataset_destroy_check, dsl_dataset_destroy_sync,
1058 ASSERT3P(dsda.rm_origin, ==, NULL);
1066 dummy_ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP);
1067 dummy_ds->ds_dir = dd;
1068 dummy_ds->ds_object = ds->ds_object;
1071 * Check for errors and mark this ds as inconsistent, in
1072 * case we crash while freeing the objects.
1074 err = dsl_sync_task_do(dd->dd_pool, dsl_dataset_destroy_begin_check,
1075 dsl_dataset_destroy_begin_sync, ds, NULL, 0);
1079 err = dmu_objset_from_ds(ds, &os);
1084 * remove the objects in open context, so that we won't
1085 * have too much to do in syncing context.
1087 for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE,
1088 ds->ds_phys->ds_prev_snap_txg)) {
1090 * Ignore errors, if there is not enough disk space
1091 * we will deal with it in dsl_dataset_destroy_sync().
1093 (void) dmu_free_object(os, obj);
1099 * Only the ZIL knows how to free log blocks.
1101 zil_destroy(dmu_objset_zil(os), B_FALSE);
1104 * Sync out all in-flight IO.
1106 txg_wait_synced(dd->dd_pool, 0);
1109 * If we managed to free all the objects in open
1110 * context, the user space accounting should be zero.
1112 if (ds->ds_phys->ds_bp.blk_fill == 0 &&
1113 dmu_objset_userused_enabled(os)) {
1114 ASSERTV(uint64_t count);
1115 ASSERT(zap_count(os, DMU_USERUSED_OBJECT, &count) != 0 ||
1117 ASSERT(zap_count(os, DMU_GROUPUSED_OBJECT, &count) != 0 ||
1121 rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
1122 err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd);
1123 rw_exit(&dd->dd_pool->dp_config_rwlock);
1129 * Blow away the dsl_dir + head dataset.
1131 dsl_dataset_make_exclusive(ds, tag);
1133 * If we're removing a clone, we might also need to remove its
1137 dsda.need_prep = B_FALSE;
1138 if (dsl_dir_is_clone(dd)) {
1139 err = dsl_dataset_origin_rm_prep(&dsda, tag);
1141 dsl_dir_close(dd, FTAG);
1146 dstg = dsl_sync_task_group_create(ds->ds_dir->dd_pool);
1147 dsl_sync_task_create(dstg, dsl_dataset_destroy_check,
1148 dsl_dataset_destroy_sync, &dsda, tag, 0);
1149 dsl_sync_task_create(dstg, dsl_dir_destroy_check,
1150 dsl_dir_destroy_sync, dummy_ds, FTAG, 0);
1151 err = dsl_sync_task_group_wait(dstg);
1152 dsl_sync_task_group_destroy(dstg);
1155 * We could be racing against 'zfs release' or 'zfs destroy -d'
1156 * on the origin snap, in which case we can get EBUSY if we
1157 * needed to destroy the origin snap but were not ready to
1160 if (dsda.need_prep) {
1161 ASSERT(err == EBUSY);
1162 ASSERT(dsl_dir_is_clone(dd));
1163 ASSERT(dsda.rm_origin == NULL);
1165 } while (dsda.need_prep);
1167 if (dsda.rm_origin != NULL)
1168 dsl_dataset_disown(dsda.rm_origin, tag);
1170 /* if it is successful, dsl_dir_destroy_sync will close the dd */
1172 dsl_dir_close(dd, FTAG);
1175 kmem_free(dummy_ds, sizeof (dsl_dataset_t));
1177 dsl_dataset_disown(ds, tag);
1182 dsl_dataset_get_blkptr(dsl_dataset_t *ds)
1184 return (&ds->ds_phys->ds_bp);
1188 dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx)
1190 ASSERT(dmu_tx_is_syncing(tx));
1191 /* If it's the meta-objset, set dp_meta_rootbp */
1193 tx->tx_pool->dp_meta_rootbp = *bp;
1195 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1196 ds->ds_phys->ds_bp = *bp;
1201 dsl_dataset_get_spa(dsl_dataset_t *ds)
1203 return (ds->ds_dir->dd_pool->dp_spa);
1207 dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx)
1211 if (ds == NULL) /* this is the meta-objset */
1214 ASSERT(ds->ds_objset != NULL);
1216 if (ds->ds_phys->ds_next_snap_obj != 0)
1217 panic("dirtying snapshot!");
1219 dp = ds->ds_dir->dd_pool;
1221 if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg) == 0) {
1222 /* up the hold count until we can be written out */
1223 dmu_buf_add_ref(ds->ds_dbuf, ds);
1228 * The unique space in the head dataset can be calculated by subtracting
1229 * the space used in the most recent snapshot, that is still being used
1230 * in this file system, from the space currently in use. To figure out
1231 * the space in the most recent snapshot still in use, we need to take
1232 * the total space used in the snapshot and subtract out the space that
1233 * has been freed up since the snapshot was taken.
1236 dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds)
1239 uint64_t dlused, dlcomp, dluncomp;
1241 ASSERT(!dsl_dataset_is_snapshot(ds));
1243 if (ds->ds_phys->ds_prev_snap_obj != 0)
1244 mrs_used = ds->ds_prev->ds_phys->ds_used_bytes;
1248 dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp);
1250 ASSERT3U(dlused, <=, mrs_used);
1251 ds->ds_phys->ds_unique_bytes =
1252 ds->ds_phys->ds_used_bytes - (mrs_used - dlused);
1254 if (spa_version(ds->ds_dir->dd_pool->dp_spa) >=
1255 SPA_VERSION_UNIQUE_ACCURATE)
1256 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
1266 kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf,
1267 const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
1269 struct killarg *ka = arg;
1270 dmu_tx_t *tx = ka->tx;
1275 if (zb->zb_level == ZB_ZIL_LEVEL) {
1276 ASSERT(zilog != NULL);
1278 * It's a block in the intent log. It has no
1279 * accounting, so just free it.
1281 dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp);
1283 ASSERT(zilog == NULL);
1284 ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg);
1285 (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE);
1293 dsl_dataset_destroy_begin_check(void *arg1, void *arg2, dmu_tx_t *tx)
1295 dsl_dataset_t *ds = arg1;
1296 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1301 * Can't delete a head dataset if there are snapshots of it.
1302 * (Except if the only snapshots are from the branch we cloned
1305 if (ds->ds_prev != NULL &&
1306 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object)
1310 * This is really a dsl_dir thing, but check it here so that
1311 * we'll be less likely to leave this dataset inconsistent &
1314 err = zap_count(mos, ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count);
1325 dsl_dataset_destroy_begin_sync(void *arg1, void *arg2, dmu_tx_t *tx)
1327 dsl_dataset_t *ds = arg1;
1328 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1330 /* Mark it as inconsistent on-disk, in case we crash */
1331 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1332 ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT;
1334 spa_history_log_internal(LOG_DS_DESTROY_BEGIN, dp->dp_spa, tx,
1335 "dataset = %llu", ds->ds_object);
1339 dsl_dataset_origin_check(struct dsl_ds_destroyarg *dsda, void *tag,
1342 dsl_dataset_t *ds = dsda->ds;
1343 dsl_dataset_t *ds_prev = ds->ds_prev;
1345 if (dsl_dataset_might_destroy_origin(ds_prev)) {
1346 struct dsl_ds_destroyarg ndsda = {0};
1349 * If we're not prepared to remove the origin, don't remove
1352 if (dsda->rm_origin == NULL) {
1353 dsda->need_prep = B_TRUE;
1358 ndsda.is_origin_rm = B_TRUE;
1359 return (dsl_dataset_destroy_check(&ndsda, tag, tx));
1363 * If we're not going to remove the origin after all,
1364 * undo the open context setup.
1366 if (dsda->rm_origin != NULL) {
1367 dsl_dataset_disown(dsda->rm_origin, tag);
1368 dsda->rm_origin = NULL;
1375 * If you add new checks here, you may need to add
1376 * additional checks to the "temporary" case in
1377 * snapshot_check() in dmu_objset.c.
1381 dsl_dataset_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx)
1383 struct dsl_ds_destroyarg *dsda = arg1;
1384 dsl_dataset_t *ds = dsda->ds;
1386 /* we have an owner hold, so noone else can destroy us */
1387 ASSERT(!DSL_DATASET_IS_DESTROYED(ds));
1390 * Only allow deferred destroy on pools that support it.
1391 * NOTE: deferred destroy is only supported on snapshots.
1394 if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
1395 SPA_VERSION_USERREFS)
1397 ASSERT(dsl_dataset_is_snapshot(ds));
1402 * Can't delete a head dataset if there are snapshots of it.
1403 * (Except if the only snapshots are from the branch we cloned
1406 if (ds->ds_prev != NULL &&
1407 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object)
1411 * If we made changes this txg, traverse_dsl_dataset won't find
1414 if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg)
1417 if (dsl_dataset_is_snapshot(ds)) {
1419 * If this snapshot has an elevated user reference count,
1420 * we can't destroy it yet.
1422 if (ds->ds_userrefs > 0 && !dsda->releasing)
1425 mutex_enter(&ds->ds_lock);
1427 * Can't delete a branch point. However, if we're destroying
1428 * a clone and removing its origin due to it having a user
1429 * hold count of 0 and having been marked for deferred destroy,
1430 * it's OK for the origin to have a single clone.
1432 if (ds->ds_phys->ds_num_children >
1433 (dsda->is_origin_rm ? 2 : 1)) {
1434 mutex_exit(&ds->ds_lock);
1437 mutex_exit(&ds->ds_lock);
1438 } else if (dsl_dir_is_clone(ds->ds_dir)) {
1439 return (dsl_dataset_origin_check(dsda, arg2, tx));
1442 /* XXX we should do some i/o error checking... */
1454 dsl_dataset_refs_gone(dmu_buf_t *db, void *argv)
1456 struct refsarg *arg = argv;
1458 mutex_enter(&arg->lock);
1460 cv_signal(&arg->cv);
1461 mutex_exit(&arg->lock);
1465 dsl_dataset_drain_refs(dsl_dataset_t *ds, void *tag)
1469 mutex_init(&arg.lock, NULL, MUTEX_DEFAULT, NULL);
1470 cv_init(&arg.cv, NULL, CV_DEFAULT, NULL);
1472 (void) dmu_buf_update_user(ds->ds_dbuf, ds, &arg, &ds->ds_phys,
1473 dsl_dataset_refs_gone);
1474 dmu_buf_rele(ds->ds_dbuf, tag);
1475 mutex_enter(&arg.lock);
1477 cv_wait(&arg.cv, &arg.lock);
1479 mutex_exit(&arg.lock);
1482 mutex_destroy(&arg.lock);
1483 cv_destroy(&arg.cv);
1487 remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj, dmu_tx_t *tx)
1489 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1491 ASSERTV(uint64_t count);
1493 ASSERT(ds->ds_phys->ds_num_children >= 2);
1494 err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx);
1496 * The err should not be ENOENT, but a bug in a previous version
1497 * of the code could cause upgrade_clones_cb() to not set
1498 * ds_next_snap_obj when it should, leading to a missing entry.
1499 * If we knew that the pool was created after
1500 * SPA_VERSION_NEXT_CLONES, we could assert that it isn't
1501 * ENOENT. However, at least we can check that we don't have
1502 * too many entries in the next_clones_obj even after failing to
1505 if (err != ENOENT) {
1506 VERIFY3U(err, ==, 0);
1508 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj,
1510 ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2);
1514 dsl_dataset_remove_clones_key(dsl_dataset_t *ds, uint64_t mintxg, dmu_tx_t *tx)
1516 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1521 * If it is the old version, dd_clones doesn't exist so we can't
1522 * find the clones, but deadlist_remove_key() is a no-op so it
1525 if (ds->ds_dir->dd_phys->dd_clones == 0)
1528 for (zap_cursor_init(&zc, mos, ds->ds_dir->dd_phys->dd_clones);
1529 zap_cursor_retrieve(&zc, &za) == 0;
1530 zap_cursor_advance(&zc)) {
1531 dsl_dataset_t *clone;
1533 VERIFY3U(0, ==, dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
1534 za.za_first_integer, FTAG, &clone));
1535 if (clone->ds_dir->dd_origin_txg > mintxg) {
1536 dsl_deadlist_remove_key(&clone->ds_deadlist,
1538 dsl_dataset_remove_clones_key(clone, mintxg, tx);
1540 dsl_dataset_rele(clone, FTAG);
1542 zap_cursor_fini(&zc);
1545 struct process_old_arg {
1547 dsl_dataset_t *ds_prev;
1548 boolean_t after_branch_point;
1550 uint64_t used, comp, uncomp;
1554 process_old_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
1556 struct process_old_arg *poa = arg;
1557 dsl_pool_t *dp = poa->ds->ds_dir->dd_pool;
1559 if (bp->blk_birth <= poa->ds->ds_phys->ds_prev_snap_txg) {
1560 dsl_deadlist_insert(&poa->ds->ds_deadlist, bp, tx);
1561 if (poa->ds_prev && !poa->after_branch_point &&
1563 poa->ds_prev->ds_phys->ds_prev_snap_txg) {
1564 poa->ds_prev->ds_phys->ds_unique_bytes +=
1565 bp_get_dsize_sync(dp->dp_spa, bp);
1568 poa->used += bp_get_dsize_sync(dp->dp_spa, bp);
1569 poa->comp += BP_GET_PSIZE(bp);
1570 poa->uncomp += BP_GET_UCSIZE(bp);
1571 dsl_free_sync(poa->pio, dp, tx->tx_txg, bp);
1577 process_old_deadlist(dsl_dataset_t *ds, dsl_dataset_t *ds_prev,
1578 dsl_dataset_t *ds_next, boolean_t after_branch_point, dmu_tx_t *tx)
1580 struct process_old_arg poa = { 0 };
1581 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1582 objset_t *mos = dp->dp_meta_objset;
1584 ASSERT(ds->ds_deadlist.dl_oldfmt);
1585 ASSERT(ds_next->ds_deadlist.dl_oldfmt);
1588 poa.ds_prev = ds_prev;
1589 poa.after_branch_point = after_branch_point;
1590 poa.pio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
1591 VERIFY3U(0, ==, bpobj_iterate(&ds_next->ds_deadlist.dl_bpobj,
1592 process_old_cb, &poa, tx));
1593 VERIFY3U(zio_wait(poa.pio), ==, 0);
1594 ASSERT3U(poa.used, ==, ds->ds_phys->ds_unique_bytes);
1596 /* change snapused */
1597 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
1598 -poa.used, -poa.comp, -poa.uncomp, tx);
1600 /* swap next's deadlist to our deadlist */
1601 dsl_deadlist_close(&ds->ds_deadlist);
1602 dsl_deadlist_close(&ds_next->ds_deadlist);
1603 SWITCH64(ds_next->ds_phys->ds_deadlist_obj,
1604 ds->ds_phys->ds_deadlist_obj);
1605 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj);
1606 dsl_deadlist_open(&ds_next->ds_deadlist, mos,
1607 ds_next->ds_phys->ds_deadlist_obj);
1611 dsl_dataset_destroy_sync(void *arg1, void *tag, dmu_tx_t *tx)
1613 struct dsl_ds_destroyarg *dsda = arg1;
1614 dsl_dataset_t *ds = dsda->ds;
1616 int after_branch_point = FALSE;
1617 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1618 objset_t *mos = dp->dp_meta_objset;
1619 dsl_dataset_t *ds_prev = NULL;
1620 boolean_t wont_destroy;
1623 wont_destroy = (dsda->defer &&
1624 (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1));
1626 ASSERT(ds->ds_owner || wont_destroy);
1627 ASSERT(dsda->defer || ds->ds_phys->ds_num_children <= 1);
1628 ASSERT(ds->ds_prev == NULL ||
1629 ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object);
1630 ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg);
1633 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
1634 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1635 ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY;
1639 /* signal any waiters that this dataset is going away */
1640 mutex_enter(&ds->ds_lock);
1641 ds->ds_owner = dsl_reaper;
1642 cv_broadcast(&ds->ds_exclusive_cv);
1643 mutex_exit(&ds->ds_lock);
1645 /* Remove our reservation */
1646 if (ds->ds_reserved != 0) {
1647 dsl_prop_setarg_t psa;
1650 dsl_prop_setarg_init_uint64(&psa, "refreservation",
1651 (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED),
1653 psa.psa_effective_value = 0; /* predict default value */
1655 dsl_dataset_set_reservation_sync(ds, &psa, tx);
1656 ASSERT3U(ds->ds_reserved, ==, 0);
1659 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
1661 dsl_scan_ds_destroyed(ds, tx);
1663 obj = ds->ds_object;
1665 if (ds->ds_phys->ds_prev_snap_obj != 0) {
1667 ds_prev = ds->ds_prev;
1669 VERIFY(0 == dsl_dataset_hold_obj(dp,
1670 ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev));
1672 after_branch_point =
1673 (ds_prev->ds_phys->ds_next_snap_obj != obj);
1675 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx);
1676 if (after_branch_point &&
1677 ds_prev->ds_phys->ds_next_clones_obj != 0) {
1678 remove_from_next_clones(ds_prev, obj, tx);
1679 if (ds->ds_phys->ds_next_snap_obj != 0) {
1680 VERIFY(0 == zap_add_int(mos,
1681 ds_prev->ds_phys->ds_next_clones_obj,
1682 ds->ds_phys->ds_next_snap_obj, tx));
1685 if (after_branch_point &&
1686 ds->ds_phys->ds_next_snap_obj == 0) {
1687 /* This clone is toast. */
1688 ASSERT(ds_prev->ds_phys->ds_num_children > 1);
1689 ds_prev->ds_phys->ds_num_children--;
1692 * If the clone's origin has no other clones, no
1693 * user holds, and has been marked for deferred
1694 * deletion, then we should have done the necessary
1695 * destroy setup for it.
1697 if (ds_prev->ds_phys->ds_num_children == 1 &&
1698 ds_prev->ds_userrefs == 0 &&
1699 DS_IS_DEFER_DESTROY(ds_prev)) {
1700 ASSERT3P(dsda->rm_origin, !=, NULL);
1702 ASSERT3P(dsda->rm_origin, ==, NULL);
1704 } else if (!after_branch_point) {
1705 ds_prev->ds_phys->ds_next_snap_obj =
1706 ds->ds_phys->ds_next_snap_obj;
1710 if (dsl_dataset_is_snapshot(ds)) {
1711 dsl_dataset_t *ds_next;
1712 uint64_t old_unique;
1713 uint64_t used = 0, comp = 0, uncomp = 0;
1715 VERIFY(0 == dsl_dataset_hold_obj(dp,
1716 ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next));
1717 ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj);
1719 old_unique = ds_next->ds_phys->ds_unique_bytes;
1721 dmu_buf_will_dirty(ds_next->ds_dbuf, tx);
1722 ds_next->ds_phys->ds_prev_snap_obj =
1723 ds->ds_phys->ds_prev_snap_obj;
1724 ds_next->ds_phys->ds_prev_snap_txg =
1725 ds->ds_phys->ds_prev_snap_txg;
1726 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
1727 ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0);
1730 if (ds_next->ds_deadlist.dl_oldfmt) {
1731 process_old_deadlist(ds, ds_prev, ds_next,
1732 after_branch_point, tx);
1734 /* Adjust prev's unique space. */
1735 if (ds_prev && !after_branch_point) {
1736 dsl_deadlist_space_range(&ds_next->ds_deadlist,
1737 ds_prev->ds_phys->ds_prev_snap_txg,
1738 ds->ds_phys->ds_prev_snap_txg,
1739 &used, &comp, &uncomp);
1740 ds_prev->ds_phys->ds_unique_bytes += used;
1743 /* Adjust snapused. */
1744 dsl_deadlist_space_range(&ds_next->ds_deadlist,
1745 ds->ds_phys->ds_prev_snap_txg, UINT64_MAX,
1746 &used, &comp, &uncomp);
1747 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
1748 -used, -comp, -uncomp, tx);
1750 /* Move blocks to be freed to pool's free list. */
1751 dsl_deadlist_move_bpobj(&ds_next->ds_deadlist,
1752 &dp->dp_free_bpobj, ds->ds_phys->ds_prev_snap_txg,
1754 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir,
1755 DD_USED_HEAD, used, comp, uncomp, tx);
1756 dsl_dir_dirty(tx->tx_pool->dp_free_dir, tx);
1758 /* Merge our deadlist into next's and free it. */
1759 dsl_deadlist_merge(&ds_next->ds_deadlist,
1760 ds->ds_phys->ds_deadlist_obj, tx);
1762 dsl_deadlist_close(&ds->ds_deadlist);
1763 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx);
1765 /* Collapse range in clone heads */
1766 dsl_dataset_remove_clones_key(ds,
1767 ds->ds_phys->ds_creation_txg, tx);
1769 if (dsl_dataset_is_snapshot(ds_next)) {
1770 dsl_dataset_t *ds_nextnext;
1774 * Update next's unique to include blocks which
1775 * were previously shared by only this snapshot
1776 * and it. Those blocks will be born after the
1777 * prev snap and before this snap, and will have
1778 * died after the next snap and before the one
1779 * after that (ie. be on the snap after next's
1782 VERIFY(0 == dsl_dataset_hold_obj(dp,
1783 ds_next->ds_phys->ds_next_snap_obj,
1784 FTAG, &ds_nextnext));
1785 dsl_deadlist_space_range(&ds_nextnext->ds_deadlist,
1786 ds->ds_phys->ds_prev_snap_txg,
1787 ds->ds_phys->ds_creation_txg,
1788 &used, &comp, &uncomp);
1789 ds_next->ds_phys->ds_unique_bytes += used;
1790 dsl_dataset_rele(ds_nextnext, FTAG);
1791 ASSERT3P(ds_next->ds_prev, ==, NULL);
1793 /* Collapse range in this head. */
1794 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
1795 ds->ds_dir->dd_phys->dd_head_dataset_obj,
1797 dsl_deadlist_remove_key(&hds->ds_deadlist,
1798 ds->ds_phys->ds_creation_txg, tx);
1799 dsl_dataset_rele(hds, FTAG);
1802 ASSERT3P(ds_next->ds_prev, ==, ds);
1803 dsl_dataset_drop_ref(ds_next->ds_prev, ds_next);
1804 ds_next->ds_prev = NULL;
1806 VERIFY(0 == dsl_dataset_get_ref(dp,
1807 ds->ds_phys->ds_prev_snap_obj,
1808 ds_next, &ds_next->ds_prev));
1811 dsl_dataset_recalc_head_uniq(ds_next);
1814 * Reduce the amount of our unconsmed refreservation
1815 * being charged to our parent by the amount of
1816 * new unique data we have gained.
1818 if (old_unique < ds_next->ds_reserved) {
1820 uint64_t new_unique =
1821 ds_next->ds_phys->ds_unique_bytes;
1823 ASSERT(old_unique <= new_unique);
1824 mrsdelta = MIN(new_unique - old_unique,
1825 ds_next->ds_reserved - old_unique);
1826 dsl_dir_diduse_space(ds->ds_dir,
1827 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx);
1830 dsl_dataset_rele(ds_next, FTAG);
1833 * There's no next snapshot, so this is a head dataset.
1834 * Destroy the deadlist. Unless it's a clone, the
1835 * deadlist should be empty. (If it's a clone, it's
1836 * safe to ignore the deadlist contents.)
1840 dsl_deadlist_close(&ds->ds_deadlist);
1841 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx);
1842 ds->ds_phys->ds_deadlist_obj = 0;
1845 * Free everything that we point to (that's born after
1846 * the previous snapshot, if we are a clone)
1848 * NB: this should be very quick, because we already
1849 * freed all the objects in open context.
1853 err = traverse_dataset(ds, ds->ds_phys->ds_prev_snap_txg,
1854 TRAVERSE_POST, kill_blkptr, &ka);
1855 ASSERT3U(err, ==, 0);
1856 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) ||
1857 ds->ds_phys->ds_unique_bytes == 0);
1859 if (ds->ds_prev != NULL) {
1860 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
1861 VERIFY3U(0, ==, zap_remove_int(mos,
1862 ds->ds_prev->ds_dir->dd_phys->dd_clones,
1863 ds->ds_object, tx));
1865 dsl_dataset_rele(ds->ds_prev, ds);
1866 ds->ds_prev = ds_prev = NULL;
1871 * This must be done after the dsl_traverse(), because it will
1872 * re-open the objset.
1874 if (ds->ds_objset) {
1875 dmu_objset_evict(ds->ds_objset);
1876 ds->ds_objset = NULL;
1879 if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) {
1880 /* Erase the link in the dir */
1881 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx);
1882 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0;
1883 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0);
1884 err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx);
1887 /* remove from snapshot namespace */
1888 dsl_dataset_t *ds_head;
1889 ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0);
1890 VERIFY(0 == dsl_dataset_hold_obj(dp,
1891 ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head));
1892 VERIFY(0 == dsl_dataset_get_snapname(ds));
1897 err = dsl_dataset_snap_lookup(ds_head,
1898 ds->ds_snapname, &val);
1899 ASSERT3U(err, ==, 0);
1900 ASSERT3U(val, ==, obj);
1903 err = dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx);
1905 dsl_dataset_rele(ds_head, FTAG);
1908 if (ds_prev && ds->ds_prev != ds_prev)
1909 dsl_dataset_rele(ds_prev, FTAG);
1911 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx);
1912 spa_history_log_internal(LOG_DS_DESTROY, dp->dp_spa, tx,
1913 "dataset = %llu", ds->ds_object);
1915 if (ds->ds_phys->ds_next_clones_obj != 0) {
1916 ASSERTV(uint64_t count);
1917 ASSERT(0 == zap_count(mos,
1918 ds->ds_phys->ds_next_clones_obj, &count) && count == 0);
1919 VERIFY(0 == dmu_object_free(mos,
1920 ds->ds_phys->ds_next_clones_obj, tx));
1922 if (ds->ds_phys->ds_props_obj != 0)
1923 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_props_obj, tx));
1924 if (ds->ds_phys->ds_userrefs_obj != 0)
1925 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx));
1926 dsl_dir_close(ds->ds_dir, ds);
1928 dsl_dataset_drain_refs(ds, tag);
1929 VERIFY(0 == dmu_object_free(mos, obj, tx));
1931 if (dsda->rm_origin) {
1933 * Remove the origin of the clone we just destroyed.
1935 struct dsl_ds_destroyarg ndsda = {0};
1937 ndsda.ds = dsda->rm_origin;
1938 dsl_dataset_destroy_sync(&ndsda, tag, tx);
1943 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx)
1947 if (!dmu_tx_is_syncing(tx))
1951 * If there's an fs-only reservation, any blocks that might become
1952 * owned by the snapshot dataset must be accommodated by space
1953 * outside of the reservation.
1955 ASSERT(ds->ds_reserved == 0 || DS_UNIQUE_IS_ACCURATE(ds));
1956 asize = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
1957 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
1961 * Propogate any reserved space for this snapshot to other
1962 * snapshot checks in this sync group.
1965 dsl_dir_willuse_space(ds->ds_dir, asize, tx);
1971 dsl_dataset_snapshot_check(void *arg1, void *arg2, dmu_tx_t *tx)
1973 dsl_dataset_t *ds = arg1;
1974 const char *snapname = arg2;
1979 * We don't allow multiple snapshots of the same txg. If there
1980 * is already one, try again.
1982 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg)
1986 * Check for conflicting name snapshot name.
1988 err = dsl_dataset_snap_lookup(ds, snapname, &value);
1995 * Check that the dataset's name is not too long. Name consists
1996 * of the dataset's length + 1 for the @-sign + snapshot name's length
1998 if (dsl_dataset_namelen(ds) + 1 + strlen(snapname) >= MAXNAMELEN)
1999 return (ENAMETOOLONG);
2001 err = dsl_dataset_snapshot_reserve_space(ds, tx);
2005 ds->ds_trysnap_txg = tx->tx_txg;
2010 dsl_dataset_snapshot_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2012 dsl_dataset_t *ds = arg1;
2013 const char *snapname = arg2;
2014 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2016 dsl_dataset_phys_t *dsphys;
2017 uint64_t dsobj, crtxg;
2018 objset_t *mos = dp->dp_meta_objset;
2021 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
2024 * The origin's ds_creation_txg has to be < TXG_INITIAL
2026 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0)
2031 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
2032 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
2033 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
2034 dmu_buf_will_dirty(dbuf, tx);
2035 dsphys = dbuf->db_data;
2036 bzero(dsphys, sizeof (dsl_dataset_phys_t));
2037 dsphys->ds_dir_obj = ds->ds_dir->dd_object;
2038 dsphys->ds_fsid_guid = unique_create();
2039 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
2040 sizeof (dsphys->ds_guid));
2041 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj;
2042 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg;
2043 dsphys->ds_next_snap_obj = ds->ds_object;
2044 dsphys->ds_num_children = 1;
2045 dsphys->ds_creation_time = gethrestime_sec();
2046 dsphys->ds_creation_txg = crtxg;
2047 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj;
2048 dsphys->ds_used_bytes = ds->ds_phys->ds_used_bytes;
2049 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes;
2050 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes;
2051 dsphys->ds_flags = ds->ds_phys->ds_flags;
2052 dsphys->ds_bp = ds->ds_phys->ds_bp;
2053 dmu_buf_rele(dbuf, FTAG);
2055 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0);
2057 uint64_t next_clones_obj =
2058 ds->ds_prev->ds_phys->ds_next_clones_obj;
2059 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj ==
2061 ds->ds_prev->ds_phys->ds_num_children > 1);
2062 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) {
2063 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
2064 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
2065 ds->ds_prev->ds_phys->ds_creation_txg);
2066 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj;
2067 } else if (next_clones_obj != 0) {
2068 remove_from_next_clones(ds->ds_prev,
2069 dsphys->ds_next_snap_obj, tx);
2070 VERIFY3U(0, ==, zap_add_int(mos,
2071 next_clones_obj, dsobj, tx));
2076 * If we have a reference-reservation on this dataset, we will
2077 * need to increase the amount of refreservation being charged
2078 * since our unique space is going to zero.
2080 if (ds->ds_reserved) {
2082 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
2083 delta = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
2084 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV,
2088 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2089 zfs_dbgmsg("taking snapshot %s@%s/%llu; newkey=%llu",
2090 ds->ds_dir->dd_myname, snapname, dsobj,
2091 ds->ds_phys->ds_prev_snap_txg);
2092 ds->ds_phys->ds_deadlist_obj = dsl_deadlist_clone(&ds->ds_deadlist,
2093 UINT64_MAX, ds->ds_phys->ds_prev_snap_obj, tx);
2094 dsl_deadlist_close(&ds->ds_deadlist);
2095 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj);
2096 dsl_deadlist_add_key(&ds->ds_deadlist,
2097 ds->ds_phys->ds_prev_snap_txg, tx);
2099 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg);
2100 ds->ds_phys->ds_prev_snap_obj = dsobj;
2101 ds->ds_phys->ds_prev_snap_txg = crtxg;
2102 ds->ds_phys->ds_unique_bytes = 0;
2103 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
2104 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
2106 err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj,
2107 snapname, 8, 1, &dsobj, tx);
2111 dsl_dataset_drop_ref(ds->ds_prev, ds);
2112 VERIFY(0 == dsl_dataset_get_ref(dp,
2113 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev));
2115 dsl_scan_ds_snapshotted(ds, tx);
2117 dsl_dir_snap_cmtime_update(ds->ds_dir);
2119 spa_history_log_internal(LOG_DS_SNAPSHOT, dp->dp_spa, tx,
2120 "dataset = %llu", dsobj);
2124 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx)
2126 ASSERT(dmu_tx_is_syncing(tx));
2127 ASSERT(ds->ds_objset != NULL);
2128 ASSERT(ds->ds_phys->ds_next_snap_obj == 0);
2131 * in case we had to change ds_fsid_guid when we opened it,
2134 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2135 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid;
2137 dsl_dir_dirty(ds->ds_dir, tx);
2138 dmu_objset_sync(ds->ds_objset, zio, tx);
2142 get_clones_stat(dsl_dataset_t *ds, nvlist_t *nv)
2145 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
2151 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER);
2152 VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2153 VERIFY(nvlist_alloc(&val, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2156 * There may me missing entries in ds_next_clones_obj
2157 * due to a bug in a previous version of the code.
2158 * Only trust it if it has the right number of entries.
2160 if (ds->ds_phys->ds_next_clones_obj != 0) {
2161 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj,
2164 if (count != ds->ds_phys->ds_num_children - 1) {
2167 for (zap_cursor_init(&zc, mos, ds->ds_phys->ds_next_clones_obj);
2168 zap_cursor_retrieve(&zc, &za) == 0;
2169 zap_cursor_advance(&zc)) {
2170 dsl_dataset_t *clone;
2171 char buf[ZFS_MAXNAMELEN];
2172 if (dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
2173 za.za_first_integer, FTAG, &clone) != 0) {
2176 dsl_dir_name(clone->ds_dir, buf);
2177 VERIFY(nvlist_add_boolean(val, buf) == 0);
2178 dsl_dataset_rele(clone, FTAG);
2180 zap_cursor_fini(&zc);
2181 VERIFY(nvlist_add_nvlist(propval, ZPROP_VALUE, val) == 0);
2182 VERIFY(nvlist_add_nvlist(nv, zfs_prop_to_name(ZFS_PROP_CLONES),
2186 nvlist_free(propval);
2187 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock);
2191 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv)
2193 uint64_t refd, avail, uobjs, aobjs, ratio;
2195 dsl_dir_stats(ds->ds_dir, nv);
2197 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs);
2198 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail);
2199 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd);
2201 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION,
2202 ds->ds_phys->ds_creation_time);
2203 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG,
2204 ds->ds_phys->ds_creation_txg);
2205 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA,
2207 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION,
2209 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID,
2210 ds->ds_phys->ds_guid);
2211 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE,
2212 ds->ds_phys->ds_unique_bytes);
2213 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID,
2215 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS,
2217 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY,
2218 DS_IS_DEFER_DESTROY(ds) ? 1 : 0);
2220 if (ds->ds_phys->ds_prev_snap_obj != 0) {
2221 uint64_t written, comp, uncomp;
2222 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2223 dsl_dataset_t *prev;
2226 rw_enter(&dp->dp_config_rwlock, RW_READER);
2227 err = dsl_dataset_hold_obj(dp,
2228 ds->ds_phys->ds_prev_snap_obj, FTAG, &prev);
2229 rw_exit(&dp->dp_config_rwlock);
2231 err = dsl_dataset_space_written(prev, ds, &written,
2233 dsl_dataset_rele(prev, FTAG);
2235 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_WRITTEN,
2241 ratio = ds->ds_phys->ds_compressed_bytes == 0 ? 100 :
2242 (ds->ds_phys->ds_uncompressed_bytes * 100 /
2243 ds->ds_phys->ds_compressed_bytes);
2244 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRATIO, ratio);
2246 if (ds->ds_phys->ds_next_snap_obj) {
2248 * This is a snapshot; override the dd's space used with
2249 * our unique space and compression ratio.
2251 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED,
2252 ds->ds_phys->ds_unique_bytes);
2253 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, ratio);
2255 get_clones_stat(ds, nv);
2260 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat)
2262 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg;
2263 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT;
2264 stat->dds_guid = ds->ds_phys->ds_guid;
2265 if (ds->ds_phys->ds_next_snap_obj) {
2266 stat->dds_is_snapshot = B_TRUE;
2267 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1;
2269 stat->dds_is_snapshot = B_FALSE;
2270 stat->dds_num_clones = 0;
2273 /* clone origin is really a dsl_dir thing... */
2274 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER);
2275 if (dsl_dir_is_clone(ds->ds_dir)) {
2278 VERIFY(0 == dsl_dataset_get_ref(ds->ds_dir->dd_pool,
2279 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods));
2280 dsl_dataset_name(ods, stat->dds_origin);
2281 dsl_dataset_drop_ref(ods, FTAG);
2283 stat->dds_origin[0] = '\0';
2285 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock);
2289 dsl_dataset_fsid_guid(dsl_dataset_t *ds)
2291 return (ds->ds_fsid_guid);
2295 dsl_dataset_space(dsl_dataset_t *ds,
2296 uint64_t *refdbytesp, uint64_t *availbytesp,
2297 uint64_t *usedobjsp, uint64_t *availobjsp)
2299 *refdbytesp = ds->ds_phys->ds_used_bytes;
2300 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE);
2301 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes)
2302 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes;
2303 if (ds->ds_quota != 0) {
2305 * Adjust available bytes according to refquota
2307 if (*refdbytesp < ds->ds_quota)
2308 *availbytesp = MIN(*availbytesp,
2309 ds->ds_quota - *refdbytesp);
2313 *usedobjsp = ds->ds_phys->ds_bp.blk_fill;
2314 *availobjsp = DN_MAX_OBJECT - *usedobjsp;
2318 dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds)
2320 ASSERTV(dsl_pool_t *dp = ds->ds_dir->dd_pool);
2322 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) ||
2323 dsl_pool_sync_context(dp));
2324 if (ds->ds_prev == NULL)
2326 if (ds->ds_phys->ds_bp.blk_birth >
2327 ds->ds_prev->ds_phys->ds_creation_txg) {
2328 objset_t *os, *os_prev;
2330 * It may be that only the ZIL differs, because it was
2331 * reset in the head. Don't count that as being
2334 if (dmu_objset_from_ds(ds, &os) != 0)
2336 if (dmu_objset_from_ds(ds->ds_prev, &os_prev) != 0)
2338 return (bcmp(&os->os_phys->os_meta_dnode,
2339 &os_prev->os_phys->os_meta_dnode,
2340 sizeof (os->os_phys->os_meta_dnode)) != 0);
2347 dsl_dataset_snapshot_rename_check(void *arg1, void *arg2, dmu_tx_t *tx)
2349 dsl_dataset_t *ds = arg1;
2350 char *newsnapname = arg2;
2351 dsl_dir_t *dd = ds->ds_dir;
2356 err = dsl_dataset_hold_obj(dd->dd_pool,
2357 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds);
2361 /* new name better not be in use */
2362 err = dsl_dataset_snap_lookup(hds, newsnapname, &val);
2363 dsl_dataset_rele(hds, FTAG);
2367 else if (err == ENOENT)
2370 /* dataset name + 1 for the "@" + the new snapshot name must fit */
2371 if (dsl_dir_namelen(ds->ds_dir) + 1 + strlen(newsnapname) >= MAXNAMELEN)
2378 dsl_dataset_snapshot_rename_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2380 dsl_dataset_t *ds = arg1;
2381 const char *newsnapname = arg2;
2382 dsl_dir_t *dd = ds->ds_dir;
2383 objset_t *mos = dd->dd_pool->dp_meta_objset;
2387 ASSERT(ds->ds_phys->ds_next_snap_obj != 0);
2389 VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool,
2390 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds));
2392 VERIFY(0 == dsl_dataset_get_snapname(ds));
2393 err = dsl_dataset_snap_remove(hds, ds->ds_snapname, tx);
2394 ASSERT3U(err, ==, 0);
2395 mutex_enter(&ds->ds_lock);
2396 (void) strcpy(ds->ds_snapname, newsnapname);
2397 mutex_exit(&ds->ds_lock);
2398 err = zap_add(mos, hds->ds_phys->ds_snapnames_zapobj,
2399 ds->ds_snapname, 8, 1, &ds->ds_object, tx);
2400 ASSERT3U(err, ==, 0);
2402 spa_history_log_internal(LOG_DS_RENAME, dd->dd_pool->dp_spa, tx,
2403 "dataset = %llu", ds->ds_object);
2404 dsl_dataset_rele(hds, FTAG);
2407 struct renamesnaparg {
2408 dsl_sync_task_group_t *dstg;
2409 char failed[MAXPATHLEN];
2415 dsl_snapshot_rename_one(const char *name, void *arg)
2417 struct renamesnaparg *ra = arg;
2418 dsl_dataset_t *ds = NULL;
2422 snapname = kmem_asprintf("%s@%s", name, ra->oldsnap);
2423 (void) strlcpy(ra->failed, snapname, sizeof (ra->failed));
2426 * For recursive snapshot renames the parent won't be changing
2427 * so we just pass name for both the to/from argument.
2429 err = zfs_secpolicy_rename_perms(snapname, snapname, CRED());
2432 return (err == ENOENT ? 0 : err);
2437 * For all filesystems undergoing rename, we'll need to unmount it.
2439 (void) zfs_unmount_snap(snapname, NULL);
2441 err = dsl_dataset_hold(snapname, ra->dstg, &ds);
2444 return (err == ENOENT ? 0 : err);
2446 dsl_sync_task_create(ra->dstg, dsl_dataset_snapshot_rename_check,
2447 dsl_dataset_snapshot_rename_sync, ds, ra->newsnap, 0);
2453 dsl_recursive_rename(char *oldname, const char *newname)
2456 struct renamesnaparg *ra;
2457 dsl_sync_task_t *dst;
2459 char *cp, *fsname = spa_strdup(oldname);
2460 int len = strlen(oldname) + 1;
2462 /* truncate the snapshot name to get the fsname */
2463 cp = strchr(fsname, '@');
2466 err = spa_open(fsname, &spa, FTAG);
2468 kmem_free(fsname, len);
2471 ra = kmem_alloc(sizeof (struct renamesnaparg), KM_SLEEP);
2472 ra->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
2474 ra->oldsnap = strchr(oldname, '@') + 1;
2475 ra->newsnap = strchr(newname, '@') + 1;
2478 err = dmu_objset_find(fsname, dsl_snapshot_rename_one, ra,
2480 kmem_free(fsname, len);
2483 err = dsl_sync_task_group_wait(ra->dstg);
2486 for (dst = list_head(&ra->dstg->dstg_tasks); dst;
2487 dst = list_next(&ra->dstg->dstg_tasks, dst)) {
2488 dsl_dataset_t *ds = dst->dst_arg1;
2490 dsl_dir_name(ds->ds_dir, ra->failed);
2491 (void) strlcat(ra->failed, "@", sizeof (ra->failed));
2492 (void) strlcat(ra->failed, ra->newsnap,
2493 sizeof (ra->failed));
2495 dsl_dataset_rele(ds, ra->dstg);
2499 (void) strlcpy(oldname, ra->failed, sizeof (ra->failed));
2501 dsl_sync_task_group_destroy(ra->dstg);
2502 kmem_free(ra, sizeof (struct renamesnaparg));
2503 spa_close(spa, FTAG);
2508 dsl_valid_rename(const char *oldname, void *arg)
2510 int delta = *(int *)arg;
2512 if (strlen(oldname) + delta >= MAXNAMELEN)
2513 return (ENAMETOOLONG);
2518 #pragma weak dmu_objset_rename = dsl_dataset_rename
2520 dsl_dataset_rename(char *oldname, const char *newname, boolean_t recursive)
2527 err = dsl_dir_open(oldname, FTAG, &dd, &tail);
2532 int delta = strlen(newname) - strlen(oldname);
2534 /* if we're growing, validate child name lengths */
2536 err = dmu_objset_find(oldname, dsl_valid_rename,
2537 &delta, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS);
2540 err = dsl_dir_rename(dd, newname);
2541 dsl_dir_close(dd, FTAG);
2545 if (tail[0] != '@') {
2546 /* the name ended in a nonexistent component */
2547 dsl_dir_close(dd, FTAG);
2551 dsl_dir_close(dd, FTAG);
2553 /* new name must be snapshot in same filesystem */
2554 tail = strchr(newname, '@');
2558 if (strncmp(oldname, newname, tail - newname) != 0)
2562 err = dsl_recursive_rename(oldname, newname);
2564 err = dsl_dataset_hold(oldname, FTAG, &ds);
2568 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
2569 dsl_dataset_snapshot_rename_check,
2570 dsl_dataset_snapshot_rename_sync, ds, (char *)tail, 1);
2572 dsl_dataset_rele(ds, FTAG);
2578 struct promotenode {
2584 list_t shared_snaps, origin_snaps, clone_snaps;
2585 dsl_dataset_t *origin_origin;
2586 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap;
2590 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep);
2593 dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx)
2595 dsl_dataset_t *hds = arg1;
2596 struct promotearg *pa = arg2;
2597 struct promotenode *snap = list_head(&pa->shared_snaps);
2598 dsl_dataset_t *origin_ds = snap->ds;
2602 /* Check that it is a real clone */
2603 if (!dsl_dir_is_clone(hds->ds_dir))
2606 /* Since this is so expensive, don't do the preliminary check */
2607 if (!dmu_tx_is_syncing(tx))
2610 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE)
2613 /* compute origin's new unique space */
2614 snap = list_tail(&pa->clone_snaps);
2615 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2616 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2617 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX,
2618 &pa->unique, &unused, &unused);
2621 * Walk the snapshots that we are moving
2623 * Compute space to transfer. Consider the incremental changes
2624 * to used for each snapshot:
2625 * (my used) = (prev's used) + (blocks born) - (blocks killed)
2626 * So each snapshot gave birth to:
2627 * (blocks born) = (my used) - (prev's used) + (blocks killed)
2628 * So a sequence would look like:
2629 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0)
2630 * Which simplifies to:
2631 * uN + kN + kN-1 + ... + k1 + k0
2632 * Note however, if we stop before we reach the ORIGIN we get:
2633 * uN + kN + kN-1 + ... + kM - uM-1
2635 pa->used = origin_ds->ds_phys->ds_used_bytes;
2636 pa->comp = origin_ds->ds_phys->ds_compressed_bytes;
2637 pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes;
2638 for (snap = list_head(&pa->shared_snaps); snap;
2639 snap = list_next(&pa->shared_snaps, snap)) {
2640 uint64_t val, dlused, dlcomp, dluncomp;
2641 dsl_dataset_t *ds = snap->ds;
2643 /* Check that the snapshot name does not conflict */
2644 VERIFY(0 == dsl_dataset_get_snapname(ds));
2645 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val);
2653 /* The very first snapshot does not have a deadlist */
2654 if (ds->ds_phys->ds_prev_snap_obj == 0)
2657 dsl_deadlist_space(&ds->ds_deadlist,
2658 &dlused, &dlcomp, &dluncomp);
2661 pa->uncomp += dluncomp;
2665 * If we are a clone of a clone then we never reached ORIGIN,
2666 * so we need to subtract out the clone origin's used space.
2668 if (pa->origin_origin) {
2669 pa->used -= pa->origin_origin->ds_phys->ds_used_bytes;
2670 pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes;
2671 pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes;
2674 /* Check that there is enough space here */
2675 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir,
2681 * Compute the amounts of space that will be used by snapshots
2682 * after the promotion (for both origin and clone). For each,
2683 * it is the amount of space that will be on all of their
2684 * deadlists (that was not born before their new origin).
2686 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2690 * Note, typically this will not be a clone of a clone,
2691 * so dd_origin_txg will be < TXG_INITIAL, so
2692 * these snaplist_space() -> dsl_deadlist_space_range()
2693 * calls will be fast because they do not have to
2694 * iterate over all bps.
2696 snap = list_head(&pa->origin_snaps);
2697 err = snaplist_space(&pa->shared_snaps,
2698 snap->ds->ds_dir->dd_origin_txg, &pa->cloneusedsnap);
2702 err = snaplist_space(&pa->clone_snaps,
2703 snap->ds->ds_dir->dd_origin_txg, &space);
2706 pa->cloneusedsnap += space;
2708 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2709 err = snaplist_space(&pa->origin_snaps,
2710 origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap);
2717 pa->err_ds = snap->ds->ds_snapname;
2722 dsl_dataset_promote_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2724 dsl_dataset_t *hds = arg1;
2725 struct promotearg *pa = arg2;
2726 struct promotenode *snap = list_head(&pa->shared_snaps);
2727 dsl_dataset_t *origin_ds = snap->ds;
2728 dsl_dataset_t *origin_head;
2729 dsl_dir_t *dd = hds->ds_dir;
2730 dsl_pool_t *dp = hds->ds_dir->dd_pool;
2731 dsl_dir_t *odd = NULL;
2732 uint64_t oldnext_obj;
2735 ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE));
2737 snap = list_head(&pa->origin_snaps);
2738 origin_head = snap->ds;
2741 * We need to explicitly open odd, since origin_ds's dd will be
2744 VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object,
2747 /* change origin's next snap */
2748 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx);
2749 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj;
2750 snap = list_tail(&pa->clone_snaps);
2751 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2752 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object;
2754 /* change the origin's next clone */
2755 if (origin_ds->ds_phys->ds_next_clones_obj) {
2756 remove_from_next_clones(origin_ds, snap->ds->ds_object, tx);
2757 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2758 origin_ds->ds_phys->ds_next_clones_obj,
2763 dmu_buf_will_dirty(dd->dd_dbuf, tx);
2764 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object);
2765 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj;
2766 dd->dd_origin_txg = origin_head->ds_dir->dd_origin_txg;
2767 dmu_buf_will_dirty(odd->dd_dbuf, tx);
2768 odd->dd_phys->dd_origin_obj = origin_ds->ds_object;
2769 origin_head->ds_dir->dd_origin_txg =
2770 origin_ds->ds_phys->ds_creation_txg;
2772 /* change dd_clone entries */
2773 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2774 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
2775 odd->dd_phys->dd_clones, hds->ds_object, tx));
2776 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2777 pa->origin_origin->ds_dir->dd_phys->dd_clones,
2778 hds->ds_object, tx));
2780 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
2781 pa->origin_origin->ds_dir->dd_phys->dd_clones,
2782 origin_head->ds_object, tx));
2783 if (dd->dd_phys->dd_clones == 0) {
2784 dd->dd_phys->dd_clones = zap_create(dp->dp_meta_objset,
2785 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
2787 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2788 dd->dd_phys->dd_clones, origin_head->ds_object, tx));
2792 /* move snapshots to this dir */
2793 for (snap = list_head(&pa->shared_snaps); snap;
2794 snap = list_next(&pa->shared_snaps, snap)) {
2795 dsl_dataset_t *ds = snap->ds;
2797 /* unregister props as dsl_dir is changing */
2798 if (ds->ds_objset) {
2799 dmu_objset_evict(ds->ds_objset);
2800 ds->ds_objset = NULL;
2802 /* move snap name entry */
2803 VERIFY(0 == dsl_dataset_get_snapname(ds));
2804 VERIFY(0 == dsl_dataset_snap_remove(origin_head,
2805 ds->ds_snapname, tx));
2806 VERIFY(0 == zap_add(dp->dp_meta_objset,
2807 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname,
2808 8, 1, &ds->ds_object, tx));
2810 /* change containing dsl_dir */
2811 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2812 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object);
2813 ds->ds_phys->ds_dir_obj = dd->dd_object;
2814 ASSERT3P(ds->ds_dir, ==, odd);
2815 dsl_dir_close(ds->ds_dir, ds);
2816 VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object,
2817 NULL, ds, &ds->ds_dir));
2819 /* move any clone references */
2820 if (ds->ds_phys->ds_next_clones_obj &&
2821 spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2825 for (zap_cursor_init(&zc, dp->dp_meta_objset,
2826 ds->ds_phys->ds_next_clones_obj);
2827 zap_cursor_retrieve(&zc, &za) == 0;
2828 zap_cursor_advance(&zc)) {
2829 dsl_dataset_t *cnds;
2832 if (za.za_first_integer == oldnext_obj) {
2834 * We've already moved the
2835 * origin's reference.
2840 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
2841 za.za_first_integer, FTAG, &cnds));
2842 o = cnds->ds_dir->dd_phys->dd_head_dataset_obj;
2844 VERIFY3U(zap_remove_int(dp->dp_meta_objset,
2845 odd->dd_phys->dd_clones, o, tx), ==, 0);
2846 VERIFY3U(zap_add_int(dp->dp_meta_objset,
2847 dd->dd_phys->dd_clones, o, tx), ==, 0);
2848 dsl_dataset_rele(cnds, FTAG);
2850 zap_cursor_fini(&zc);
2853 ASSERT3U(dsl_prop_numcb(ds), ==, 0);
2857 * Change space accounting.
2858 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either
2859 * both be valid, or both be 0 (resulting in delta == 0). This
2860 * is true for each of {clone,origin} independently.
2863 delta = pa->cloneusedsnap -
2864 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2865 ASSERT3S(delta, >=, 0);
2866 ASSERT3U(pa->used, >=, delta);
2867 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx);
2868 dsl_dir_diduse_space(dd, DD_USED_HEAD,
2869 pa->used - delta, pa->comp, pa->uncomp, tx);
2871 delta = pa->originusedsnap -
2872 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2873 ASSERT3S(delta, <=, 0);
2874 ASSERT3U(pa->used, >=, -delta);
2875 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx);
2876 dsl_dir_diduse_space(odd, DD_USED_HEAD,
2877 -pa->used - delta, -pa->comp, -pa->uncomp, tx);
2879 origin_ds->ds_phys->ds_unique_bytes = pa->unique;
2881 /* log history record */
2882 spa_history_log_internal(LOG_DS_PROMOTE, dd->dd_pool->dp_spa, tx,
2883 "dataset = %llu", hds->ds_object);
2885 dsl_dir_close(odd, FTAG);
2888 static char *snaplist_tag = "snaplist";
2890 * Make a list of dsl_dataset_t's for the snapshots between first_obj
2891 * (exclusive) and last_obj (inclusive). The list will be in reverse
2892 * order (last_obj will be the list_head()). If first_obj == 0, do all
2893 * snapshots back to this dataset's origin.
2896 snaplist_make(dsl_pool_t *dp, boolean_t own,
2897 uint64_t first_obj, uint64_t last_obj, list_t *l)
2899 uint64_t obj = last_obj;
2901 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock));
2903 list_create(l, sizeof (struct promotenode),
2904 offsetof(struct promotenode, link));
2906 while (obj != first_obj) {
2908 struct promotenode *snap;
2912 err = dsl_dataset_own_obj(dp, obj,
2913 0, snaplist_tag, &ds);
2915 dsl_dataset_make_exclusive(ds, snaplist_tag);
2917 err = dsl_dataset_hold_obj(dp, obj, snaplist_tag, &ds);
2919 if (err == ENOENT) {
2920 /* lost race with snapshot destroy */
2921 struct promotenode *last = list_tail(l);
2922 ASSERT(obj != last->ds->ds_phys->ds_prev_snap_obj);
2923 obj = last->ds->ds_phys->ds_prev_snap_obj;
2930 first_obj = ds->ds_dir->dd_phys->dd_origin_obj;
2932 snap = kmem_alloc(sizeof (struct promotenode), KM_SLEEP);
2934 list_insert_tail(l, snap);
2935 obj = ds->ds_phys->ds_prev_snap_obj;
2942 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep)
2944 struct promotenode *snap;
2947 for (snap = list_head(l); snap; snap = list_next(l, snap)) {
2948 uint64_t used, comp, uncomp;
2949 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2950 mintxg, UINT64_MAX, &used, &comp, &uncomp);
2957 snaplist_destroy(list_t *l, boolean_t own)
2959 struct promotenode *snap;
2961 if (!l || !list_link_active(&l->list_head))
2964 while ((snap = list_tail(l)) != NULL) {
2965 list_remove(l, snap);
2967 dsl_dataset_disown(snap->ds, snaplist_tag);
2969 dsl_dataset_rele(snap->ds, snaplist_tag);
2970 kmem_free(snap, sizeof (struct promotenode));
2976 * Promote a clone. Nomenclature note:
2977 * "clone" or "cds": the original clone which is being promoted
2978 * "origin" or "ods": the snapshot which is originally clone's origin
2979 * "origin head" or "ohds": the dataset which is the head
2980 * (filesystem/volume) for the origin
2981 * "origin origin": the origin of the origin's filesystem (typically
2982 * NULL, indicating that the clone is not a clone of a clone).
2985 dsl_dataset_promote(const char *name, char *conflsnap)
2990 dmu_object_info_t doi;
2991 struct promotearg pa;
2992 struct promotenode *snap;
2995 bzero(&pa, sizeof(struct promotearg));
2996 err = dsl_dataset_hold(name, FTAG, &ds);
3002 err = dmu_object_info(dp->dp_meta_objset,
3003 ds->ds_phys->ds_snapnames_zapobj, &doi);
3005 dsl_dataset_rele(ds, FTAG);
3009 if (dsl_dataset_is_snapshot(ds) || dd->dd_phys->dd_origin_obj == 0) {
3010 dsl_dataset_rele(ds, FTAG);
3015 * We are going to inherit all the snapshots taken before our
3016 * origin (i.e., our new origin will be our parent's origin).
3017 * Take ownership of them so that we can rename them into our
3020 rw_enter(&dp->dp_config_rwlock, RW_READER);
3022 err = snaplist_make(dp, B_TRUE, 0, dd->dd_phys->dd_origin_obj,
3027 err = snaplist_make(dp, B_FALSE, 0, ds->ds_object, &pa.clone_snaps);
3031 snap = list_head(&pa.shared_snaps);
3032 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj);
3033 err = snaplist_make(dp, B_FALSE, dd->dd_phys->dd_origin_obj,
3034 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj, &pa.origin_snaps);
3038 if (snap->ds->ds_dir->dd_phys->dd_origin_obj != 0) {
3039 err = dsl_dataset_hold_obj(dp,
3040 snap->ds->ds_dir->dd_phys->dd_origin_obj,
3041 FTAG, &pa.origin_origin);
3047 rw_exit(&dp->dp_config_rwlock);
3050 * Add in 128x the snapnames zapobj size, since we will be moving
3051 * a bunch of snapnames to the promoted ds, and dirtying their
3055 err = dsl_sync_task_do(dp, dsl_dataset_promote_check,
3056 dsl_dataset_promote_sync, ds, &pa,
3057 2 + 2 * doi.doi_physical_blocks_512);
3058 if (err && pa.err_ds && conflsnap)
3059 (void) strncpy(conflsnap, pa.err_ds, MAXNAMELEN);
3062 snaplist_destroy(&pa.shared_snaps, B_TRUE);
3063 snaplist_destroy(&pa.clone_snaps, B_FALSE);
3064 snaplist_destroy(&pa.origin_snaps, B_FALSE);
3065 if (pa.origin_origin)
3066 dsl_dataset_rele(pa.origin_origin, FTAG);
3067 dsl_dataset_rele(ds, FTAG);
3071 struct cloneswaparg {
3072 dsl_dataset_t *cds; /* clone dataset */
3073 dsl_dataset_t *ohds; /* origin's head dataset */
3075 int64_t unused_refres_delta; /* change in unconsumed refreservation */
3080 dsl_dataset_clone_swap_check(void *arg1, void *arg2, dmu_tx_t *tx)
3082 struct cloneswaparg *csa = arg1;
3084 /* they should both be heads */
3085 if (dsl_dataset_is_snapshot(csa->cds) ||
3086 dsl_dataset_is_snapshot(csa->ohds))
3089 /* the branch point should be just before them */
3090 if (csa->cds->ds_prev != csa->ohds->ds_prev)
3093 /* cds should be the clone (unless they are unrelated) */
3094 if (csa->cds->ds_prev != NULL &&
3095 csa->cds->ds_prev != csa->cds->ds_dir->dd_pool->dp_origin_snap &&
3096 csa->ohds->ds_object !=
3097 csa->cds->ds_prev->ds_phys->ds_next_snap_obj)
3100 /* the clone should be a child of the origin */
3101 if (csa->cds->ds_dir->dd_parent != csa->ohds->ds_dir)
3104 /* ohds shouldn't be modified unless 'force' */
3105 if (!csa->force && dsl_dataset_modified_since_lastsnap(csa->ohds))
3108 /* adjust amount of any unconsumed refreservation */
3109 csa->unused_refres_delta =
3110 (int64_t)MIN(csa->ohds->ds_reserved,
3111 csa->ohds->ds_phys->ds_unique_bytes) -
3112 (int64_t)MIN(csa->ohds->ds_reserved,
3113 csa->cds->ds_phys->ds_unique_bytes);
3115 if (csa->unused_refres_delta > 0 &&
3116 csa->unused_refres_delta >
3117 dsl_dir_space_available(csa->ohds->ds_dir, NULL, 0, TRUE))
3120 if (csa->ohds->ds_quota != 0 &&
3121 csa->cds->ds_phys->ds_unique_bytes > csa->ohds->ds_quota)
3129 dsl_dataset_clone_swap_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3131 struct cloneswaparg *csa = arg1;
3132 dsl_pool_t *dp = csa->cds->ds_dir->dd_pool;
3134 ASSERT(csa->cds->ds_reserved == 0);
3135 ASSERT(csa->ohds->ds_quota == 0 ||
3136 csa->cds->ds_phys->ds_unique_bytes <= csa->ohds->ds_quota);
3138 dmu_buf_will_dirty(csa->cds->ds_dbuf, tx);
3139 dmu_buf_will_dirty(csa->ohds->ds_dbuf, tx);
3141 if (csa->cds->ds_objset != NULL) {
3142 dmu_objset_evict(csa->cds->ds_objset);
3143 csa->cds->ds_objset = NULL;
3146 if (csa->ohds->ds_objset != NULL) {
3147 dmu_objset_evict(csa->ohds->ds_objset);
3148 csa->ohds->ds_objset = NULL;
3152 * Reset origin's unique bytes, if it exists.
3154 if (csa->cds->ds_prev) {
3155 dsl_dataset_t *origin = csa->cds->ds_prev;
3156 uint64_t comp, uncomp;
3158 dmu_buf_will_dirty(origin->ds_dbuf, tx);
3159 dsl_deadlist_space_range(&csa->cds->ds_deadlist,
3160 origin->ds_phys->ds_prev_snap_txg, UINT64_MAX,
3161 &origin->ds_phys->ds_unique_bytes, &comp, &uncomp);
3167 tmp = csa->ohds->ds_phys->ds_bp;
3168 csa->ohds->ds_phys->ds_bp = csa->cds->ds_phys->ds_bp;
3169 csa->cds->ds_phys->ds_bp = tmp;
3172 /* set dd_*_bytes */
3174 int64_t dused, dcomp, duncomp;
3175 uint64_t cdl_used, cdl_comp, cdl_uncomp;
3176 uint64_t odl_used, odl_comp, odl_uncomp;
3178 ASSERT3U(csa->cds->ds_dir->dd_phys->
3179 dd_used_breakdown[DD_USED_SNAP], ==, 0);
3181 dsl_deadlist_space(&csa->cds->ds_deadlist,
3182 &cdl_used, &cdl_comp, &cdl_uncomp);
3183 dsl_deadlist_space(&csa->ohds->ds_deadlist,
3184 &odl_used, &odl_comp, &odl_uncomp);
3186 dused = csa->cds->ds_phys->ds_used_bytes + cdl_used -
3187 (csa->ohds->ds_phys->ds_used_bytes + odl_used);
3188 dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp -
3189 (csa->ohds->ds_phys->ds_compressed_bytes + odl_comp);
3190 duncomp = csa->cds->ds_phys->ds_uncompressed_bytes +
3192 (csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp);
3194 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD,
3195 dused, dcomp, duncomp, tx);
3196 dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD,
3197 -dused, -dcomp, -duncomp, tx);
3200 * The difference in the space used by snapshots is the
3201 * difference in snapshot space due to the head's
3202 * deadlist (since that's the only thing that's
3203 * changing that affects the snapused).
3205 dsl_deadlist_space_range(&csa->cds->ds_deadlist,
3206 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX,
3207 &cdl_used, &cdl_comp, &cdl_uncomp);
3208 dsl_deadlist_space_range(&csa->ohds->ds_deadlist,
3209 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX,
3210 &odl_used, &odl_comp, &odl_uncomp);
3211 dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used,
3212 DD_USED_HEAD, DD_USED_SNAP, tx);
3215 /* swap ds_*_bytes */
3216 SWITCH64(csa->ohds->ds_phys->ds_used_bytes,
3217 csa->cds->ds_phys->ds_used_bytes);
3218 SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes,
3219 csa->cds->ds_phys->ds_compressed_bytes);
3220 SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes,
3221 csa->cds->ds_phys->ds_uncompressed_bytes);
3222 SWITCH64(csa->ohds->ds_phys->ds_unique_bytes,
3223 csa->cds->ds_phys->ds_unique_bytes);
3225 /* apply any parent delta for change in unconsumed refreservation */
3226 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV,
3227 csa->unused_refres_delta, 0, 0, tx);
3232 dsl_deadlist_close(&csa->cds->ds_deadlist);
3233 dsl_deadlist_close(&csa->ohds->ds_deadlist);
3234 SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj,
3235 csa->cds->ds_phys->ds_deadlist_obj);
3236 dsl_deadlist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset,
3237 csa->cds->ds_phys->ds_deadlist_obj);
3238 dsl_deadlist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset,
3239 csa->ohds->ds_phys->ds_deadlist_obj);
3241 dsl_scan_ds_clone_swapped(csa->ohds, csa->cds, tx);
3245 * Swap 'clone' with its origin head datasets. Used at the end of "zfs
3246 * recv" into an existing fs to swizzle the file system to the new
3247 * version, and by "zfs rollback". Can also be used to swap two
3248 * independent head datasets if neither has any snapshots.
3251 dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head,
3254 struct cloneswaparg csa;
3257 ASSERT(clone->ds_owner);
3258 ASSERT(origin_head->ds_owner);
3261 * Need exclusive access for the swap. If we're swapping these
3262 * datasets back after an error, we already hold the locks.
3264 if (!RW_WRITE_HELD(&clone->ds_rwlock))
3265 rw_enter(&clone->ds_rwlock, RW_WRITER);
3266 if (!RW_WRITE_HELD(&origin_head->ds_rwlock) &&
3267 !rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) {
3268 rw_exit(&clone->ds_rwlock);
3269 rw_enter(&origin_head->ds_rwlock, RW_WRITER);
3270 if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) {
3271 rw_exit(&origin_head->ds_rwlock);
3276 csa.ohds = origin_head;
3278 error = dsl_sync_task_do(clone->ds_dir->dd_pool,
3279 dsl_dataset_clone_swap_check,
3280 dsl_dataset_clone_swap_sync, &csa, NULL, 9);
3285 * Given a pool name and a dataset object number in that pool,
3286 * return the name of that dataset.
3289 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf)
3296 if ((error = spa_open(pname, &spa, FTAG)) != 0)
3298 dp = spa_get_dsl(spa);
3299 rw_enter(&dp->dp_config_rwlock, RW_READER);
3300 if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) {
3301 dsl_dataset_name(ds, buf);
3302 dsl_dataset_rele(ds, FTAG);
3304 rw_exit(&dp->dp_config_rwlock);
3305 spa_close(spa, FTAG);
3311 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota,
3312 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv)
3316 ASSERT3S(asize, >, 0);
3319 * *ref_rsrv is the portion of asize that will come from any
3320 * unconsumed refreservation space.
3324 mutex_enter(&ds->ds_lock);
3326 * Make a space adjustment for reserved bytes.
3328 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) {
3330 ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
3331 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
3333 asize - MIN(asize, parent_delta(ds, asize + inflight));
3336 if (!check_quota || ds->ds_quota == 0) {
3337 mutex_exit(&ds->ds_lock);
3341 * If they are requesting more space, and our current estimate
3342 * is over quota, they get to try again unless the actual
3343 * on-disk is over quota and there are no pending changes (which
3344 * may free up space for us).
3346 if (ds->ds_phys->ds_used_bytes + inflight >= ds->ds_quota) {
3347 if (inflight > 0 || ds->ds_phys->ds_used_bytes < ds->ds_quota)
3352 DMU_TX_STAT_BUMP(dmu_tx_quota);
3354 mutex_exit(&ds->ds_lock);
3361 dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx)
3363 dsl_dataset_t *ds = arg1;
3364 dsl_prop_setarg_t *psa = arg2;
3367 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA)
3370 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0)
3373 if (psa->psa_effective_value == 0)
3376 if (psa->psa_effective_value < ds->ds_phys->ds_used_bytes ||
3377 psa->psa_effective_value < ds->ds_reserved)
3383 extern void dsl_prop_set_sync(void *, void *, dmu_tx_t *);
3386 dsl_dataset_set_quota_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3388 dsl_dataset_t *ds = arg1;
3389 dsl_prop_setarg_t *psa = arg2;
3390 uint64_t effective_value = psa->psa_effective_value;
3392 dsl_prop_set_sync(ds, psa, tx);
3393 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa);
3395 if (ds->ds_quota != effective_value) {
3396 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3397 ds->ds_quota = effective_value;
3399 spa_history_log_internal(LOG_DS_REFQUOTA,
3400 ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu ",
3401 (longlong_t)ds->ds_quota, ds->ds_object);
3406 dsl_dataset_set_quota(const char *dsname, zprop_source_t source, uint64_t quota)
3409 dsl_prop_setarg_t psa;
3412 dsl_prop_setarg_init_uint64(&psa, "refquota", source, "a);
3414 err = dsl_dataset_hold(dsname, FTAG, &ds);
3419 * If someone removes a file, then tries to set the quota, we
3420 * want to make sure the file freeing takes effect.
3422 txg_wait_open(ds->ds_dir->dd_pool, 0);
3424 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
3425 dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync,
3428 dsl_dataset_rele(ds, FTAG);
3433 dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx)
3435 dsl_dataset_t *ds = arg1;
3436 dsl_prop_setarg_t *psa = arg2;
3437 uint64_t effective_value;
3441 if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
3442 SPA_VERSION_REFRESERVATION)
3445 if (dsl_dataset_is_snapshot(ds))
3448 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0)
3451 effective_value = psa->psa_effective_value;
3454 * If we are doing the preliminary check in open context, the
3455 * space estimates may be inaccurate.
3457 if (!dmu_tx_is_syncing(tx))
3460 mutex_enter(&ds->ds_lock);
3461 if (!DS_UNIQUE_IS_ACCURATE(ds))
3462 dsl_dataset_recalc_head_uniq(ds);
3463 unique = ds->ds_phys->ds_unique_bytes;
3464 mutex_exit(&ds->ds_lock);
3466 if (MAX(unique, effective_value) > MAX(unique, ds->ds_reserved)) {
3467 uint64_t delta = MAX(unique, effective_value) -
3468 MAX(unique, ds->ds_reserved);
3470 if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
3472 if (ds->ds_quota > 0 &&
3473 effective_value > ds->ds_quota)
3481 dsl_dataset_set_reservation_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3483 dsl_dataset_t *ds = arg1;
3484 dsl_prop_setarg_t *psa = arg2;
3485 uint64_t effective_value = psa->psa_effective_value;
3489 dsl_prop_set_sync(ds, psa, tx);
3490 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa);
3492 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3494 mutex_enter(&ds->ds_dir->dd_lock);
3495 mutex_enter(&ds->ds_lock);
3496 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
3497 unique = ds->ds_phys->ds_unique_bytes;
3498 delta = MAX(0, (int64_t)(effective_value - unique)) -
3499 MAX(0, (int64_t)(ds->ds_reserved - unique));
3500 ds->ds_reserved = effective_value;
3501 mutex_exit(&ds->ds_lock);
3503 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx);
3504 mutex_exit(&ds->ds_dir->dd_lock);
3506 spa_history_log_internal(LOG_DS_REFRESERV,
3507 ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu",
3508 (longlong_t)effective_value, ds->ds_object);
3512 dsl_dataset_set_reservation(const char *dsname, zprop_source_t source,
3513 uint64_t reservation)
3516 dsl_prop_setarg_t psa;
3519 dsl_prop_setarg_init_uint64(&psa, "refreservation", source,
3522 err = dsl_dataset_hold(dsname, FTAG, &ds);
3526 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
3527 dsl_dataset_set_reservation_check,
3528 dsl_dataset_set_reservation_sync, ds, &psa, 0);
3530 dsl_dataset_rele(ds, FTAG);
3534 typedef struct zfs_hold_cleanup_arg {
3537 char htag[MAXNAMELEN];
3538 } zfs_hold_cleanup_arg_t;
3541 dsl_dataset_user_release_onexit(void *arg)
3543 zfs_hold_cleanup_arg_t *ca = arg;
3545 (void) dsl_dataset_user_release_tmp(ca->dp, ca->dsobj, ca->htag,
3547 kmem_free(ca, sizeof (zfs_hold_cleanup_arg_t));
3551 dsl_register_onexit_hold_cleanup(dsl_dataset_t *ds, const char *htag,
3554 zfs_hold_cleanup_arg_t *ca;
3556 ca = kmem_alloc(sizeof (zfs_hold_cleanup_arg_t), KM_SLEEP);
3557 ca->dp = ds->ds_dir->dd_pool;
3558 ca->dsobj = ds->ds_object;
3559 (void) strlcpy(ca->htag, htag, sizeof (ca->htag));
3560 VERIFY3U(0, ==, zfs_onexit_add_cb(minor,
3561 dsl_dataset_user_release_onexit, ca, NULL));
3565 * If you add new checks here, you may need to add
3566 * additional checks to the "temporary" case in
3567 * snapshot_check() in dmu_objset.c.
3570 dsl_dataset_user_hold_check(void *arg1, void *arg2, dmu_tx_t *tx)
3572 dsl_dataset_t *ds = arg1;
3573 struct dsl_ds_holdarg *ha = arg2;
3574 char *htag = ha->htag;
3575 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3578 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS)
3581 if (!dsl_dataset_is_snapshot(ds))
3584 /* tags must be unique */
3585 mutex_enter(&ds->ds_lock);
3586 if (ds->ds_phys->ds_userrefs_obj) {
3587 error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj, htag,
3591 else if (error == ENOENT)
3594 mutex_exit(&ds->ds_lock);
3596 if (error == 0 && ha->temphold &&
3597 strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN)
3604 dsl_dataset_user_hold_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3606 dsl_dataset_t *ds = arg1;
3607 struct dsl_ds_holdarg *ha = arg2;
3608 char *htag = ha->htag;
3609 dsl_pool_t *dp = ds->ds_dir->dd_pool;
3610 objset_t *mos = dp->dp_meta_objset;
3611 uint64_t now = gethrestime_sec();
3614 mutex_enter(&ds->ds_lock);
3615 if (ds->ds_phys->ds_userrefs_obj == 0) {
3617 * This is the first user hold for this dataset. Create
3618 * the userrefs zap object.
3620 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3621 zapobj = ds->ds_phys->ds_userrefs_obj =
3622 zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx);
3624 zapobj = ds->ds_phys->ds_userrefs_obj;
3627 mutex_exit(&ds->ds_lock);
3629 VERIFY(0 == zap_add(mos, zapobj, htag, 8, 1, &now, tx));
3632 VERIFY(0 == dsl_pool_user_hold(dp, ds->ds_object,
3636 spa_history_log_internal(LOG_DS_USER_HOLD,
3637 dp->dp_spa, tx, "<%s> temp = %d dataset = %llu", htag,
3638 (int)ha->temphold, ds->ds_object);
3642 dsl_dataset_user_hold_one(const char *dsname, void *arg)
3644 struct dsl_ds_holdarg *ha = arg;
3649 /* alloc a buffer to hold dsname@snapname plus terminating NULL */
3650 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3651 error = dsl_dataset_hold(name, ha->dstg, &ds);
3654 ha->gotone = B_TRUE;
3655 dsl_sync_task_create(ha->dstg, dsl_dataset_user_hold_check,
3656 dsl_dataset_user_hold_sync, ds, ha, 0);
3657 } else if (error == ENOENT && ha->recursive) {
3660 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3666 dsl_dataset_user_hold_for_send(dsl_dataset_t *ds, char *htag,
3669 struct dsl_ds_holdarg *ha;
3672 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3674 ha->temphold = temphold;
3675 error = dsl_sync_task_do(ds->ds_dir->dd_pool,
3676 dsl_dataset_user_hold_check, dsl_dataset_user_hold_sync,
3678 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3684 dsl_dataset_user_hold(char *dsname, char *snapname, char *htag,
3685 boolean_t recursive, boolean_t temphold, int cleanup_fd)
3687 struct dsl_ds_holdarg *ha;
3688 dsl_sync_task_t *dst;
3693 if (cleanup_fd != -1) {
3694 /* Currently we only support cleanup-on-exit of tempholds. */
3697 error = zfs_onexit_fd_hold(cleanup_fd, &minor);
3702 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3704 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3706 error = spa_open(dsname, &spa, FTAG);
3708 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3709 if (cleanup_fd != -1)
3710 zfs_onexit_fd_rele(cleanup_fd);
3714 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
3716 ha->snapname = snapname;
3717 ha->recursive = recursive;
3718 ha->temphold = temphold;
3721 error = dmu_objset_find(dsname, dsl_dataset_user_hold_one,
3722 ha, DS_FIND_CHILDREN);
3724 error = dsl_dataset_user_hold_one(dsname, ha);
3727 error = dsl_sync_task_group_wait(ha->dstg);
3729 for (dst = list_head(&ha->dstg->dstg_tasks); dst;
3730 dst = list_next(&ha->dstg->dstg_tasks, dst)) {
3731 dsl_dataset_t *ds = dst->dst_arg1;
3734 dsl_dataset_name(ds, ha->failed);
3735 *strchr(ha->failed, '@') = '\0';
3736 } else if (error == 0 && minor != 0 && temphold) {
3738 * If this hold is to be released upon process exit,
3739 * register that action now.
3741 dsl_register_onexit_hold_cleanup(ds, htag, minor);
3743 dsl_dataset_rele(ds, ha->dstg);
3746 if (error == 0 && recursive && !ha->gotone)
3750 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed));
3752 dsl_sync_task_group_destroy(ha->dstg);
3754 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3755 spa_close(spa, FTAG);
3756 if (cleanup_fd != -1)
3757 zfs_onexit_fd_rele(cleanup_fd);
3761 struct dsl_ds_releasearg {
3764 boolean_t own; /* do we own or just hold ds? */
3768 dsl_dataset_release_might_destroy(dsl_dataset_t *ds, const char *htag,
3769 boolean_t *might_destroy)
3771 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3776 *might_destroy = B_FALSE;
3778 mutex_enter(&ds->ds_lock);
3779 zapobj = ds->ds_phys->ds_userrefs_obj;
3781 /* The tag can't possibly exist */
3782 mutex_exit(&ds->ds_lock);
3786 /* Make sure the tag exists */
3787 error = zap_lookup(mos, zapobj, htag, 8, 1, &tmp);
3789 mutex_exit(&ds->ds_lock);
3790 if (error == ENOENT)
3795 if (ds->ds_userrefs == 1 && ds->ds_phys->ds_num_children == 1 &&
3796 DS_IS_DEFER_DESTROY(ds))
3797 *might_destroy = B_TRUE;
3799 mutex_exit(&ds->ds_lock);
3804 dsl_dataset_user_release_check(void *arg1, void *tag, dmu_tx_t *tx)
3806 struct dsl_ds_releasearg *ra = arg1;
3807 dsl_dataset_t *ds = ra->ds;
3808 boolean_t might_destroy;
3811 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS)
3814 error = dsl_dataset_release_might_destroy(ds, ra->htag, &might_destroy);
3818 if (might_destroy) {
3819 struct dsl_ds_destroyarg dsda = {0};
3821 if (dmu_tx_is_syncing(tx)) {
3823 * If we're not prepared to remove the snapshot,
3824 * we can't allow the release to happen right now.
3830 dsda.releasing = B_TRUE;
3831 return (dsl_dataset_destroy_check(&dsda, tag, tx));
3838 dsl_dataset_user_release_sync(void *arg1, void *tag, dmu_tx_t *tx)
3840 struct dsl_ds_releasearg *ra = arg1;
3841 dsl_dataset_t *ds = ra->ds;
3842 dsl_pool_t *dp = ds->ds_dir->dd_pool;
3843 objset_t *mos = dp->dp_meta_objset;
3845 uint64_t dsobj = ds->ds_object;
3849 mutex_enter(&ds->ds_lock);
3851 refs = ds->ds_userrefs;
3852 mutex_exit(&ds->ds_lock);
3853 error = dsl_pool_user_release(dp, ds->ds_object, ra->htag, tx);
3854 VERIFY(error == 0 || error == ENOENT);
3855 zapobj = ds->ds_phys->ds_userrefs_obj;
3856 VERIFY(0 == zap_remove(mos, zapobj, ra->htag, tx));
3858 spa_history_log_internal(LOG_DS_USER_RELEASE,
3859 dp->dp_spa, tx, "<%s> %lld dataset = %llu",
3860 ra->htag, (longlong_t)refs, dsobj);
3862 if (ds->ds_userrefs == 0 && ds->ds_phys->ds_num_children == 1 &&
3863 DS_IS_DEFER_DESTROY(ds)) {
3864 struct dsl_ds_destroyarg dsda = {0};
3868 dsda.releasing = B_TRUE;
3869 /* We already did the destroy_check */
3870 dsl_dataset_destroy_sync(&dsda, tag, tx);
3875 dsl_dataset_user_release_one(const char *dsname, void *arg)
3877 struct dsl_ds_holdarg *ha = arg;
3878 struct dsl_ds_releasearg *ra;
3881 void *dtag = ha->dstg;
3883 boolean_t own = B_FALSE;
3884 boolean_t might_destroy;
3886 /* alloc a buffer to hold dsname@snapname, plus the terminating NULL */
3887 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3888 error = dsl_dataset_hold(name, dtag, &ds);
3890 if (error == ENOENT && ha->recursive)
3892 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3896 ha->gotone = B_TRUE;
3898 ASSERT(dsl_dataset_is_snapshot(ds));
3900 error = dsl_dataset_release_might_destroy(ds, ha->htag, &might_destroy);
3902 dsl_dataset_rele(ds, dtag);
3906 if (might_destroy) {
3908 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3909 error = zfs_unmount_snap(name, NULL);
3912 dsl_dataset_rele(ds, dtag);
3916 if (!dsl_dataset_tryown(ds, B_TRUE, dtag)) {
3917 dsl_dataset_rele(ds, dtag);
3921 dsl_dataset_make_exclusive(ds, dtag);
3925 ra = kmem_alloc(sizeof (struct dsl_ds_releasearg), KM_SLEEP);
3927 ra->htag = ha->htag;
3929 dsl_sync_task_create(ha->dstg, dsl_dataset_user_release_check,
3930 dsl_dataset_user_release_sync, ra, dtag, 0);
3936 dsl_dataset_user_release(char *dsname, char *snapname, char *htag,
3937 boolean_t recursive)
3939 struct dsl_ds_holdarg *ha;
3940 dsl_sync_task_t *dst;
3945 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3947 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3949 error = spa_open(dsname, &spa, FTAG);
3951 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3955 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
3957 ha->snapname = snapname;
3958 ha->recursive = recursive;
3960 error = dmu_objset_find(dsname, dsl_dataset_user_release_one,
3961 ha, DS_FIND_CHILDREN);
3963 error = dsl_dataset_user_release_one(dsname, ha);
3966 error = dsl_sync_task_group_wait(ha->dstg);
3968 for (dst = list_head(&ha->dstg->dstg_tasks); dst;
3969 dst = list_next(&ha->dstg->dstg_tasks, dst)) {
3970 struct dsl_ds_releasearg *ra = dst->dst_arg1;
3971 dsl_dataset_t *ds = ra->ds;
3974 dsl_dataset_name(ds, ha->failed);
3977 dsl_dataset_disown(ds, ha->dstg);
3979 dsl_dataset_rele(ds, ha->dstg);
3981 kmem_free(ra, sizeof (struct dsl_ds_releasearg));
3984 if (error == 0 && recursive && !ha->gotone)
3987 if (error && error != EBUSY)
3988 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed));
3990 dsl_sync_task_group_destroy(ha->dstg);
3991 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3992 spa_close(spa, FTAG);
3995 * We can get EBUSY if we were racing with deferred destroy and
3996 * dsl_dataset_user_release_check() hadn't done the necessary
3997 * open context setup. We can also get EBUSY if we're racing
3998 * with destroy and that thread is the ds_owner. Either way
3999 * the busy condition should be transient, and we should retry
4000 * the release operation.
4009 * Called at spa_load time (with retry == B_FALSE) to release a stale
4010 * temporary user hold. Also called by the onexit code (with retry == B_TRUE).
4013 dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, char *htag,
4023 rw_enter(&dp->dp_config_rwlock, RW_READER);
4024 error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds);
4025 rw_exit(&dp->dp_config_rwlock);
4028 namelen = dsl_dataset_namelen(ds)+1;
4029 name = kmem_alloc(namelen, KM_SLEEP);
4030 dsl_dataset_name(ds, name);
4031 dsl_dataset_rele(ds, FTAG);
4033 snap = strchr(name, '@');
4036 error = dsl_dataset_user_release(name, snap, htag, B_FALSE);
4037 kmem_free(name, namelen);
4040 * The object can't have been destroyed because we have a hold,
4041 * but it might have been renamed, resulting in ENOENT. Retry
4042 * if we've been requested to do so.
4044 * It would be nice if we could use the dsobj all the way
4045 * through and avoid ENOENT entirely. But we might need to
4046 * unmount the snapshot, and there's currently no way to lookup
4047 * a vfsp using a ZFS object id.
4049 } while ((error == ENOENT) && retry);
4055 dsl_dataset_get_holds(const char *dsname, nvlist_t **nvp)
4060 err = dsl_dataset_hold(dsname, FTAG, &ds);
4064 VERIFY(0 == nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP));
4065 if (ds->ds_phys->ds_userrefs_obj != 0) {
4066 zap_attribute_t *za;
4069 za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP);
4070 for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset,
4071 ds->ds_phys->ds_userrefs_obj);
4072 zap_cursor_retrieve(&zc, za) == 0;
4073 zap_cursor_advance(&zc)) {
4074 VERIFY(0 == nvlist_add_uint64(*nvp, za->za_name,
4075 za->za_first_integer));
4077 zap_cursor_fini(&zc);
4078 kmem_free(za, sizeof (zap_attribute_t));
4080 dsl_dataset_rele(ds, FTAG);
4085 * Note, this function is used as the callback for dmu_objset_find(). We
4086 * always return 0 so that we will continue to find and process
4087 * inconsistent datasets, even if we encounter an error trying to
4088 * process one of them.
4092 dsl_destroy_inconsistent(const char *dsname, void *arg)
4096 if (dsl_dataset_own(dsname, B_TRUE, FTAG, &ds) == 0) {
4097 if (DS_IS_INCONSISTENT(ds))
4098 (void) dsl_dataset_destroy(ds, FTAG, B_FALSE);
4100 dsl_dataset_disown(ds, FTAG);
4107 * Return (in *usedp) the amount of space written in new that is not
4108 * present in oldsnap. New may be a snapshot or the head. Old must be
4109 * a snapshot before new, in new's filesystem (or its origin). If not then
4110 * fail and return EINVAL.
4112 * The written space is calculated by considering two components: First, we
4113 * ignore any freed space, and calculate the written as new's used space
4114 * minus old's used space. Next, we add in the amount of space that was freed
4115 * between the two snapshots, thus reducing new's used space relative to old's.
4116 * Specifically, this is the space that was born before old->ds_creation_txg,
4117 * and freed before new (ie. on new's deadlist or a previous deadlist).
4119 * space freed [---------------------]
4120 * snapshots ---O-------O--------O-------O------
4124 dsl_dataset_space_written(dsl_dataset_t *oldsnap, dsl_dataset_t *new,
4125 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
4129 dsl_pool_t *dp = new->ds_dir->dd_pool;
4132 *usedp += new->ds_phys->ds_used_bytes;
4133 *usedp -= oldsnap->ds_phys->ds_used_bytes;
4136 *compp += new->ds_phys->ds_compressed_bytes;
4137 *compp -= oldsnap->ds_phys->ds_compressed_bytes;
4140 *uncompp += new->ds_phys->ds_uncompressed_bytes;
4141 *uncompp -= oldsnap->ds_phys->ds_uncompressed_bytes;
4143 rw_enter(&dp->dp_config_rwlock, RW_READER);
4144 snapobj = new->ds_object;
4145 while (snapobj != oldsnap->ds_object) {
4146 dsl_dataset_t *snap;
4147 uint64_t used, comp, uncomp;
4149 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &snap);
4153 if (snap->ds_phys->ds_prev_snap_txg ==
4154 oldsnap->ds_phys->ds_creation_txg) {
4156 * The blocks in the deadlist can not be born after
4157 * ds_prev_snap_txg, so get the whole deadlist space,
4158 * which is more efficient (especially for old-format
4159 * deadlists). Unfortunately the deadlist code
4160 * doesn't have enough information to make this
4161 * optimization itself.
4163 dsl_deadlist_space(&snap->ds_deadlist,
4164 &used, &comp, &uncomp);
4166 dsl_deadlist_space_range(&snap->ds_deadlist,
4167 0, oldsnap->ds_phys->ds_creation_txg,
4168 &used, &comp, &uncomp);
4175 * If we get to the beginning of the chain of snapshots
4176 * (ds_prev_snap_obj == 0) before oldsnap, then oldsnap
4177 * was not a snapshot of/before new.
4179 snapobj = snap->ds_phys->ds_prev_snap_obj;
4180 dsl_dataset_rele(snap, FTAG);
4187 rw_exit(&dp->dp_config_rwlock);
4192 * Return (in *usedp) the amount of space that will be reclaimed if firstsnap,
4193 * lastsnap, and all snapshots in between are deleted.
4195 * blocks that would be freed [---------------------------]
4196 * snapshots ---O-------O--------O-------O--------O
4197 * firstsnap lastsnap
4199 * This is the set of blocks that were born after the snap before firstsnap,
4200 * (birth > firstsnap->prev_snap_txg) and died before the snap after the
4201 * last snap (ie, is on lastsnap->ds_next->ds_deadlist or an earlier deadlist).
4202 * We calculate this by iterating over the relevant deadlists (from the snap
4203 * after lastsnap, backward to the snap after firstsnap), summing up the
4204 * space on the deadlist that was born after the snap before firstsnap.
4207 dsl_dataset_space_wouldfree(dsl_dataset_t *firstsnap,
4208 dsl_dataset_t *lastsnap,
4209 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
4213 dsl_pool_t *dp = firstsnap->ds_dir->dd_pool;
4215 ASSERT(dsl_dataset_is_snapshot(firstsnap));
4216 ASSERT(dsl_dataset_is_snapshot(lastsnap));
4219 * Check that the snapshots are in the same dsl_dir, and firstsnap
4220 * is before lastsnap.
4222 if (firstsnap->ds_dir != lastsnap->ds_dir ||
4223 firstsnap->ds_phys->ds_creation_txg >
4224 lastsnap->ds_phys->ds_creation_txg)
4227 *usedp = *compp = *uncompp = 0;
4229 rw_enter(&dp->dp_config_rwlock, RW_READER);
4230 snapobj = lastsnap->ds_phys->ds_next_snap_obj;
4231 while (snapobj != firstsnap->ds_object) {
4233 uint64_t used, comp, uncomp;
4235 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &ds);
4239 dsl_deadlist_space_range(&ds->ds_deadlist,
4240 firstsnap->ds_phys->ds_prev_snap_txg, UINT64_MAX,
4241 &used, &comp, &uncomp);
4246 snapobj = ds->ds_phys->ds_prev_snap_obj;
4247 ASSERT3U(snapobj, !=, 0);
4248 dsl_dataset_rele(ds, FTAG);
4250 rw_exit(&dp->dp_config_rwlock);
4254 #if defined(_KERNEL) && defined(HAVE_SPL)
4255 EXPORT_SYMBOL(dmu_snapshots_destroy_nvl);
4256 EXPORT_SYMBOL(dsl_dataset_hold);
4257 EXPORT_SYMBOL(dsl_dataset_hold_obj);
4258 EXPORT_SYMBOL(dsl_dataset_own);
4259 EXPORT_SYMBOL(dsl_dataset_own_obj);
4260 EXPORT_SYMBOL(dsl_dataset_name);
4261 EXPORT_SYMBOL(dsl_dataset_rele);
4262 EXPORT_SYMBOL(dsl_dataset_disown);
4263 EXPORT_SYMBOL(dsl_dataset_drop_ref);
4264 EXPORT_SYMBOL(dsl_dataset_tryown);
4265 EXPORT_SYMBOL(dsl_dataset_make_exclusive);
4266 EXPORT_SYMBOL(dsl_dataset_create_sync);
4267 EXPORT_SYMBOL(dsl_dataset_create_sync_dd);
4268 EXPORT_SYMBOL(dsl_dataset_destroy);
4269 EXPORT_SYMBOL(dsl_dataset_destroy_check);
4270 EXPORT_SYMBOL(dsl_dataset_destroy_sync);
4271 EXPORT_SYMBOL(dsl_dataset_snapshot_check);
4272 EXPORT_SYMBOL(dsl_dataset_snapshot_sync);
4273 EXPORT_SYMBOL(dsl_dataset_rename);
4274 EXPORT_SYMBOL(dsl_dataset_promote);
4275 EXPORT_SYMBOL(dsl_dataset_clone_swap);
4276 EXPORT_SYMBOL(dsl_dataset_user_hold);
4277 EXPORT_SYMBOL(dsl_dataset_user_release);
4278 EXPORT_SYMBOL(dsl_dataset_user_release_tmp);
4279 EXPORT_SYMBOL(dsl_dataset_get_holds);
4280 EXPORT_SYMBOL(dsl_dataset_get_blkptr);
4281 EXPORT_SYMBOL(dsl_dataset_set_blkptr);
4282 EXPORT_SYMBOL(dsl_dataset_get_spa);
4283 EXPORT_SYMBOL(dsl_dataset_modified_since_lastsnap);
4284 EXPORT_SYMBOL(dsl_dataset_space_written);
4285 EXPORT_SYMBOL(dsl_dataset_space_wouldfree);
4286 EXPORT_SYMBOL(dsl_dataset_sync);
4287 EXPORT_SYMBOL(dsl_dataset_block_born);
4288 EXPORT_SYMBOL(dsl_dataset_block_kill);
4289 EXPORT_SYMBOL(dsl_dataset_block_freeable);
4290 EXPORT_SYMBOL(dsl_dataset_prev_snap_txg);
4291 EXPORT_SYMBOL(dsl_dataset_dirty);
4292 EXPORT_SYMBOL(dsl_dataset_stats);
4293 EXPORT_SYMBOL(dsl_dataset_fast_stat);
4294 EXPORT_SYMBOL(dsl_dataset_space);
4295 EXPORT_SYMBOL(dsl_dataset_fsid_guid);
4296 EXPORT_SYMBOL(dsl_dsobj_to_dsname);
4297 EXPORT_SYMBOL(dsl_dataset_check_quota);
4298 EXPORT_SYMBOL(dsl_dataset_set_quota);
4299 EXPORT_SYMBOL(dsl_dataset_set_quota_sync);
4300 EXPORT_SYMBOL(dsl_dataset_set_reservation);
4301 EXPORT_SYMBOL(dsl_destroy_inconsistent);