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.
24 * Copyright (c) 2011 Pawel Jakub Dawidek <pawel@dawidek.net>.
25 * All rights reserved.
28 #include <sys/dmu_objset.h>
29 #include <sys/dsl_dataset.h>
30 #include <sys/dsl_dir.h>
31 #include <sys/dsl_prop.h>
32 #include <sys/dsl_synctask.h>
33 #include <sys/dmu_traverse.h>
34 #include <sys/dmu_tx.h>
38 #include <sys/unique.h>
39 #include <sys/zfs_context.h>
40 #include <sys/zfs_ioctl.h>
42 #include <sys/zfs_znode.h>
43 #include <sys/zfs_onexit.h>
45 #include <sys/dsl_scan.h>
46 #include <sys/dsl_deadlist.h>
48 static char *dsl_reaper = "the grim reaper";
50 static dsl_checkfunc_t dsl_dataset_destroy_begin_check;
51 static dsl_syncfunc_t dsl_dataset_destroy_begin_sync;
52 static dsl_syncfunc_t dsl_dataset_set_reservation_sync;
54 #define SWITCH64(x, y) \
56 uint64_t __tmp = (x); \
61 #define DS_REF_MAX (1ULL << 62)
63 #define DSL_DEADLIST_BLOCKSIZE SPA_MAXBLOCKSIZE
65 #define DSL_DATASET_IS_DESTROYED(ds) ((ds)->ds_owner == dsl_reaper)
69 * Figure out how much of this delta should be propogated to the dsl_dir
70 * layer. If there's a refreservation, that space has already been
71 * partially accounted for in our ancestors.
74 parent_delta(dsl_dataset_t *ds, int64_t delta)
76 uint64_t old_bytes, new_bytes;
78 if (ds->ds_reserved == 0)
81 old_bytes = MAX(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
82 new_bytes = MAX(ds->ds_phys->ds_unique_bytes + delta, ds->ds_reserved);
84 ASSERT3U(ABS((int64_t)(new_bytes - old_bytes)), <=, ABS(delta));
85 return (new_bytes - old_bytes);
89 dsl_dataset_block_born(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx)
91 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
92 int compressed = BP_GET_PSIZE(bp);
93 int 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,
139 ASSERT(dmu_tx_is_syncing(tx));
140 ASSERT(bp->blk_birth <= tx->tx_txg);
142 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
143 int compressed = BP_GET_PSIZE(bp);
144 int uncompressed = BP_GET_UCSIZE(bp);
149 * Account for the meta-objset space in its placeholder
152 dsl_free(tx->tx_pool, tx->tx_txg, bp);
154 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD,
155 -used, -compressed, -uncompressed, tx);
156 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx);
159 ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool);
161 ASSERT(!dsl_dataset_is_snapshot(ds));
162 dmu_buf_will_dirty(ds->ds_dbuf, tx);
164 if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) {
167 dprintf_bp(bp, "freeing ds=%llu", ds->ds_object);
168 dsl_free(tx->tx_pool, tx->tx_txg, bp);
170 mutex_enter(&ds->ds_dir->dd_lock);
171 mutex_enter(&ds->ds_lock);
172 ASSERT(ds->ds_phys->ds_unique_bytes >= used ||
173 !DS_UNIQUE_IS_ACCURATE(ds));
174 delta = parent_delta(ds, -used);
175 ds->ds_phys->ds_unique_bytes -= used;
176 mutex_exit(&ds->ds_lock);
177 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
178 delta, -compressed, -uncompressed, tx);
179 dsl_dir_transfer_space(ds->ds_dir, -used - delta,
180 DD_USED_REFRSRV, DD_USED_HEAD, tx);
181 mutex_exit(&ds->ds_dir->dd_lock);
183 dprintf_bp(bp, "putting on dead list: %s", "");
186 * We are here as part of zio's write done callback,
187 * which means we're a zio interrupt thread. We can't
188 * call dsl_deadlist_insert() now because it may block
189 * waiting for I/O. Instead, put bp on the deferred
190 * queue and let dsl_pool_sync() finish the job.
192 bplist_append(&ds->ds_pending_deadlist, bp);
194 dsl_deadlist_insert(&ds->ds_deadlist, bp, tx);
196 ASSERT3U(ds->ds_prev->ds_object, ==,
197 ds->ds_phys->ds_prev_snap_obj);
198 ASSERT(ds->ds_prev->ds_phys->ds_num_children > 0);
199 /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */
200 if (ds->ds_prev->ds_phys->ds_next_snap_obj ==
201 ds->ds_object && bp->blk_birth >
202 ds->ds_prev->ds_phys->ds_prev_snap_txg) {
203 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
204 mutex_enter(&ds->ds_prev->ds_lock);
205 ds->ds_prev->ds_phys->ds_unique_bytes += used;
206 mutex_exit(&ds->ds_prev->ds_lock);
208 if (bp->blk_birth > ds->ds_dir->dd_origin_txg) {
209 dsl_dir_transfer_space(ds->ds_dir, used,
210 DD_USED_HEAD, DD_USED_SNAP, tx);
213 mutex_enter(&ds->ds_lock);
214 ASSERT3U(ds->ds_phys->ds_used_bytes, >=, used);
215 ds->ds_phys->ds_used_bytes -= used;
216 ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed);
217 ds->ds_phys->ds_compressed_bytes -= compressed;
218 ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed);
219 ds->ds_phys->ds_uncompressed_bytes -= uncompressed;
220 mutex_exit(&ds->ds_lock);
226 dsl_dataset_prev_snap_txg(dsl_dataset_t *ds)
228 uint64_t trysnap = 0;
233 * The snapshot creation could fail, but that would cause an
234 * incorrect FALSE return, which would only result in an
235 * overestimation of the amount of space that an operation would
236 * consume, which is OK.
238 * There's also a small window where we could miss a pending
239 * snapshot, because we could set the sync task in the quiescing
240 * phase. So this should only be used as a guess.
242 if (ds->ds_trysnap_txg >
243 spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa))
244 trysnap = ds->ds_trysnap_txg;
245 return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap));
249 dsl_dataset_block_freeable(dsl_dataset_t *ds, const blkptr_t *bp,
252 if (blk_birth <= dsl_dataset_prev_snap_txg(ds))
255 ddt_prefetch(dsl_dataset_get_spa(ds), bp);
262 dsl_dataset_evict(dmu_buf_t *db, void *dsv)
264 dsl_dataset_t *ds = dsv;
266 ASSERT(ds->ds_owner == NULL || DSL_DATASET_IS_DESTROYED(ds));
268 unique_remove(ds->ds_fsid_guid);
270 if (ds->ds_objset != NULL)
271 dmu_objset_evict(ds->ds_objset);
274 dsl_dataset_drop_ref(ds->ds_prev, ds);
278 bplist_destroy(&ds->ds_pending_deadlist);
280 dsl_deadlist_close(&ds->ds_deadlist);
282 ASSERT(ds->ds_deadlist.dl_dbuf == NULL);
283 ASSERT(!ds->ds_deadlist.dl_oldfmt);
286 dsl_dir_close(ds->ds_dir, ds);
288 ASSERT(!list_link_active(&ds->ds_synced_link));
290 if (mutex_owned(&ds->ds_lock))
291 mutex_exit(&ds->ds_lock);
292 mutex_destroy(&ds->ds_lock);
293 mutex_destroy(&ds->ds_recvlock);
294 if (mutex_owned(&ds->ds_opening_lock))
295 mutex_exit(&ds->ds_opening_lock);
296 mutex_destroy(&ds->ds_opening_lock);
297 rw_destroy(&ds->ds_rwlock);
298 cv_destroy(&ds->ds_exclusive_cv);
300 kmem_free(ds, sizeof (dsl_dataset_t));
304 dsl_dataset_get_snapname(dsl_dataset_t *ds)
306 dsl_dataset_phys_t *headphys;
309 dsl_pool_t *dp = ds->ds_dir->dd_pool;
310 objset_t *mos = dp->dp_meta_objset;
312 if (ds->ds_snapname[0])
314 if (ds->ds_phys->ds_next_snap_obj == 0)
317 err = dmu_bonus_hold(mos, ds->ds_dir->dd_phys->dd_head_dataset_obj,
321 headphys = headdbuf->db_data;
322 err = zap_value_search(dp->dp_meta_objset,
323 headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname);
324 dmu_buf_rele(headdbuf, FTAG);
329 dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name, uint64_t *value)
331 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
332 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
336 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
341 err = zap_lookup_norm(mos, snapobj, name, 8, 1,
342 value, mt, NULL, 0, NULL);
343 if (err == ENOTSUP && mt == MT_FIRST)
344 err = zap_lookup(mos, snapobj, name, 8, 1, value);
349 dsl_dataset_snap_remove(dsl_dataset_t *ds, char *name, dmu_tx_t *tx)
351 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
352 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
356 dsl_dir_snap_cmtime_update(ds->ds_dir);
358 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
363 err = zap_remove_norm(mos, snapobj, name, mt, tx);
364 if (err == ENOTSUP && mt == MT_FIRST)
365 err = zap_remove(mos, snapobj, name, tx);
370 dsl_dataset_get_ref(dsl_pool_t *dp, uint64_t dsobj, void *tag,
373 objset_t *mos = dp->dp_meta_objset;
377 dmu_object_info_t doi;
379 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) ||
380 dsl_pool_sync_context(dp));
382 err = dmu_bonus_hold(mos, dsobj, tag, &dbuf);
386 /* Make sure dsobj has the correct object type. */
387 dmu_object_info_from_db(dbuf, &doi);
388 if (doi.doi_type != DMU_OT_DSL_DATASET)
391 ds = dmu_buf_get_user(dbuf);
393 dsl_dataset_t *winner;
395 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP);
397 ds->ds_object = dsobj;
398 ds->ds_phys = dbuf->db_data;
400 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL);
401 mutex_init(&ds->ds_recvlock, NULL, MUTEX_DEFAULT, NULL);
402 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL);
403 rw_init(&ds->ds_rwlock, 0, 0, 0);
404 cv_init(&ds->ds_exclusive_cv, NULL, CV_DEFAULT, NULL);
406 bplist_create(&ds->ds_pending_deadlist);
407 dsl_deadlist_open(&ds->ds_deadlist,
408 mos, ds->ds_phys->ds_deadlist_obj);
411 err = dsl_dir_open_obj(dp,
412 ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir);
415 mutex_destroy(&ds->ds_lock);
416 mutex_destroy(&ds->ds_recvlock);
417 mutex_destroy(&ds->ds_opening_lock);
418 rw_destroy(&ds->ds_rwlock);
419 cv_destroy(&ds->ds_exclusive_cv);
420 bplist_destroy(&ds->ds_pending_deadlist);
421 dsl_deadlist_close(&ds->ds_deadlist);
422 kmem_free(ds, sizeof (dsl_dataset_t));
423 dmu_buf_rele(dbuf, tag);
427 if (!dsl_dataset_is_snapshot(ds)) {
428 ds->ds_snapname[0] = '\0';
429 if (ds->ds_phys->ds_prev_snap_obj) {
430 err = dsl_dataset_get_ref(dp,
431 ds->ds_phys->ds_prev_snap_obj,
435 if (zfs_flags & ZFS_DEBUG_SNAPNAMES)
436 err = dsl_dataset_get_snapname(ds);
437 if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) {
439 ds->ds_dir->dd_pool->dp_meta_objset,
440 ds->ds_phys->ds_userrefs_obj,
445 if (err == 0 && !dsl_dataset_is_snapshot(ds)) {
447 * In sync context, we're called with either no lock
448 * or with the write lock. If we're not syncing,
449 * we're always called with the read lock held.
451 boolean_t need_lock =
452 !RW_WRITE_HELD(&dp->dp_config_rwlock) &&
453 dsl_pool_sync_context(dp);
456 rw_enter(&dp->dp_config_rwlock, RW_READER);
458 err = dsl_prop_get_ds(ds,
459 "refreservation", sizeof (uint64_t), 1,
460 &ds->ds_reserved, NULL);
462 err = dsl_prop_get_ds(ds,
463 "refquota", sizeof (uint64_t), 1,
464 &ds->ds_quota, NULL);
468 rw_exit(&dp->dp_config_rwlock);
470 ds->ds_reserved = ds->ds_quota = 0;
474 winner = dmu_buf_set_user_ie(dbuf, ds, &ds->ds_phys,
478 bplist_destroy(&ds->ds_pending_deadlist);
479 dsl_deadlist_close(&ds->ds_deadlist);
481 dsl_dataset_drop_ref(ds->ds_prev, ds);
482 dsl_dir_close(ds->ds_dir, ds);
483 mutex_destroy(&ds->ds_lock);
484 mutex_destroy(&ds->ds_recvlock);
485 mutex_destroy(&ds->ds_opening_lock);
486 rw_destroy(&ds->ds_rwlock);
487 cv_destroy(&ds->ds_exclusive_cv);
488 kmem_free(ds, sizeof (dsl_dataset_t));
490 dmu_buf_rele(dbuf, tag);
496 unique_insert(ds->ds_phys->ds_fsid_guid);
499 ASSERT3P(ds->ds_dbuf, ==, dbuf);
500 ASSERT3P(ds->ds_phys, ==, dbuf->db_data);
501 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 ||
502 spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN ||
503 dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap);
504 mutex_enter(&ds->ds_lock);
505 if (!dsl_pool_sync_context(dp) && DSL_DATASET_IS_DESTROYED(ds)) {
506 mutex_exit(&ds->ds_lock);
507 dmu_buf_rele(ds->ds_dbuf, tag);
510 mutex_exit(&ds->ds_lock);
516 dsl_dataset_hold_ref(dsl_dataset_t *ds, void *tag)
518 dsl_pool_t *dp = ds->ds_dir->dd_pool;
521 * In syncing context we don't want the rwlock lock: there
522 * may be an existing writer waiting for sync phase to
523 * finish. We don't need to worry about such writers, since
524 * sync phase is single-threaded, so the writer can't be
525 * doing anything while we are active.
527 if (dsl_pool_sync_context(dp)) {
528 ASSERT(!DSL_DATASET_IS_DESTROYED(ds));
533 * Normal users will hold the ds_rwlock as a READER until they
534 * are finished (i.e., call dsl_dataset_rele()). "Owners" will
535 * drop their READER lock after they set the ds_owner field.
537 * If the dataset is being destroyed, the destroy thread will
538 * obtain a WRITER lock for exclusive access after it's done its
539 * open-context work and then change the ds_owner to
540 * dsl_reaper once destruction is assured. So threads
541 * may block here temporarily, until the "destructability" of
542 * the dataset is determined.
544 ASSERT(!RW_WRITE_HELD(&dp->dp_config_rwlock));
545 mutex_enter(&ds->ds_lock);
546 while (!rw_tryenter(&ds->ds_rwlock, RW_READER)) {
547 rw_exit(&dp->dp_config_rwlock);
548 cv_wait(&ds->ds_exclusive_cv, &ds->ds_lock);
549 if (DSL_DATASET_IS_DESTROYED(ds)) {
550 mutex_exit(&ds->ds_lock);
551 dsl_dataset_drop_ref(ds, tag);
552 rw_enter(&dp->dp_config_rwlock, RW_READER);
556 * The dp_config_rwlock lives above the ds_lock. And
557 * we need to check DSL_DATASET_IS_DESTROYED() while
558 * holding the ds_lock, so we have to drop and reacquire
561 mutex_exit(&ds->ds_lock);
562 rw_enter(&dp->dp_config_rwlock, RW_READER);
563 mutex_enter(&ds->ds_lock);
565 mutex_exit(&ds->ds_lock);
570 dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag,
573 int err = dsl_dataset_get_ref(dp, dsobj, tag, dsp);
577 return (dsl_dataset_hold_ref(*dsp, tag));
581 dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj, boolean_t inconsistentok,
582 void *tag, dsl_dataset_t **dsp)
584 int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp);
587 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) {
588 dsl_dataset_rele(*dsp, tag);
596 dsl_dataset_hold(const char *name, void *tag, dsl_dataset_t **dsp)
600 const char *snapname;
604 err = dsl_dir_open_spa(NULL, name, FTAG, &dd, &snapname);
609 obj = dd->dd_phys->dd_head_dataset_obj;
610 rw_enter(&dp->dp_config_rwlock, RW_READER);
612 err = dsl_dataset_get_ref(dp, obj, tag, dsp);
618 err = dsl_dataset_hold_ref(*dsp, tag);
620 /* we may be looking for a snapshot */
621 if (err == 0 && snapname != NULL) {
622 dsl_dataset_t *ds = NULL;
624 if (*snapname++ != '@') {
625 dsl_dataset_rele(*dsp, tag);
630 dprintf("looking for snapshot '%s'\n", snapname);
631 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj);
633 err = dsl_dataset_get_ref(dp, obj, tag, &ds);
634 dsl_dataset_rele(*dsp, tag);
636 ASSERT3U((err == 0), ==, (ds != NULL));
639 mutex_enter(&ds->ds_lock);
640 if (ds->ds_snapname[0] == 0)
641 (void) strlcpy(ds->ds_snapname, snapname,
642 sizeof (ds->ds_snapname));
643 mutex_exit(&ds->ds_lock);
644 err = dsl_dataset_hold_ref(ds, tag);
645 *dsp = err ? NULL : ds;
649 rw_exit(&dp->dp_config_rwlock);
650 dsl_dir_close(dd, FTAG);
655 dsl_dataset_own(const char *name, boolean_t inconsistentok,
656 void *tag, dsl_dataset_t **dsp)
658 int err = dsl_dataset_hold(name, tag, dsp);
661 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) {
662 dsl_dataset_rele(*dsp, tag);
669 dsl_dataset_name(dsl_dataset_t *ds, char *name)
672 (void) strcpy(name, "mos");
674 dsl_dir_name(ds->ds_dir, name);
675 VERIFY(0 == dsl_dataset_get_snapname(ds));
676 if (ds->ds_snapname[0]) {
677 (void) strcat(name, "@");
679 * We use a "recursive" mutex so that we
680 * can call dprintf_ds() with ds_lock held.
682 if (!MUTEX_HELD(&ds->ds_lock)) {
683 mutex_enter(&ds->ds_lock);
684 (void) strcat(name, ds->ds_snapname);
685 mutex_exit(&ds->ds_lock);
687 (void) strcat(name, ds->ds_snapname);
694 dsl_dataset_namelen(dsl_dataset_t *ds)
699 result = 3; /* "mos" */
701 result = dsl_dir_namelen(ds->ds_dir);
702 VERIFY(0 == dsl_dataset_get_snapname(ds));
703 if (ds->ds_snapname[0]) {
704 ++result; /* adding one for the @-sign */
705 if (!MUTEX_HELD(&ds->ds_lock)) {
706 mutex_enter(&ds->ds_lock);
707 result += strlen(ds->ds_snapname);
708 mutex_exit(&ds->ds_lock);
710 result += strlen(ds->ds_snapname);
719 dsl_dataset_drop_ref(dsl_dataset_t *ds, void *tag)
721 dmu_buf_rele(ds->ds_dbuf, tag);
725 dsl_dataset_rele(dsl_dataset_t *ds, void *tag)
727 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) {
728 rw_exit(&ds->ds_rwlock);
730 dsl_dataset_drop_ref(ds, tag);
734 dsl_dataset_disown(dsl_dataset_t *ds, void *tag)
736 ASSERT((ds->ds_owner == tag && ds->ds_dbuf) ||
737 (DSL_DATASET_IS_DESTROYED(ds) && ds->ds_dbuf == NULL));
739 mutex_enter(&ds->ds_lock);
741 if (RW_WRITE_HELD(&ds->ds_rwlock)) {
742 rw_exit(&ds->ds_rwlock);
743 cv_broadcast(&ds->ds_exclusive_cv);
745 mutex_exit(&ds->ds_lock);
747 dsl_dataset_drop_ref(ds, tag);
749 dsl_dataset_evict(NULL, ds);
753 dsl_dataset_tryown(dsl_dataset_t *ds, boolean_t inconsistentok, void *tag)
755 boolean_t gotit = FALSE;
757 mutex_enter(&ds->ds_lock);
758 if (ds->ds_owner == NULL &&
759 (!DS_IS_INCONSISTENT(ds) || inconsistentok)) {
761 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool))
762 rw_exit(&ds->ds_rwlock);
765 mutex_exit(&ds->ds_lock);
770 dsl_dataset_make_exclusive(dsl_dataset_t *ds, void *owner)
772 ASSERT3P(owner, ==, ds->ds_owner);
773 if (!RW_WRITE_HELD(&ds->ds_rwlock))
774 rw_enter(&ds->ds_rwlock, RW_WRITER);
778 dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin,
779 uint64_t flags, dmu_tx_t *tx)
781 dsl_pool_t *dp = dd->dd_pool;
783 dsl_dataset_phys_t *dsphys;
785 objset_t *mos = dp->dp_meta_objset;
788 origin = dp->dp_origin_snap;
790 ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp);
791 ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0);
792 ASSERT(dmu_tx_is_syncing(tx));
793 ASSERT(dd->dd_phys->dd_head_dataset_obj == 0);
795 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
796 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
797 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
798 dmu_buf_will_dirty(dbuf, tx);
799 dsphys = dbuf->db_data;
800 bzero(dsphys, sizeof (dsl_dataset_phys_t));
801 dsphys->ds_dir_obj = dd->dd_object;
802 dsphys->ds_flags = flags;
803 dsphys->ds_fsid_guid = unique_create();
804 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
805 sizeof (dsphys->ds_guid));
806 dsphys->ds_snapnames_zapobj =
807 zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP,
809 dsphys->ds_creation_time = gethrestime_sec();
810 dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg;
812 if (origin == NULL) {
813 dsphys->ds_deadlist_obj = dsl_deadlist_alloc(mos, tx);
817 dsphys->ds_prev_snap_obj = origin->ds_object;
818 dsphys->ds_prev_snap_txg =
819 origin->ds_phys->ds_creation_txg;
820 dsphys->ds_used_bytes =
821 origin->ds_phys->ds_used_bytes;
822 dsphys->ds_compressed_bytes =
823 origin->ds_phys->ds_compressed_bytes;
824 dsphys->ds_uncompressed_bytes =
825 origin->ds_phys->ds_uncompressed_bytes;
826 dsphys->ds_bp = origin->ds_phys->ds_bp;
827 dsphys->ds_flags |= origin->ds_phys->ds_flags;
829 dmu_buf_will_dirty(origin->ds_dbuf, tx);
830 origin->ds_phys->ds_num_children++;
832 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
833 origin->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ohds));
834 dsphys->ds_deadlist_obj = dsl_deadlist_clone(&ohds->ds_deadlist,
835 dsphys->ds_prev_snap_txg, dsphys->ds_prev_snap_obj, tx);
836 dsl_dataset_rele(ohds, FTAG);
838 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) {
839 if (origin->ds_phys->ds_next_clones_obj == 0) {
840 origin->ds_phys->ds_next_clones_obj =
842 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx);
844 VERIFY(0 == zap_add_int(mos,
845 origin->ds_phys->ds_next_clones_obj,
849 dmu_buf_will_dirty(dd->dd_dbuf, tx);
850 dd->dd_phys->dd_origin_obj = origin->ds_object;
851 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
852 if (origin->ds_dir->dd_phys->dd_clones == 0) {
853 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx);
854 origin->ds_dir->dd_phys->dd_clones =
856 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
858 VERIFY3U(0, ==, zap_add_int(mos,
859 origin->ds_dir->dd_phys->dd_clones, dsobj, tx));
863 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
864 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
866 dmu_buf_rele(dbuf, FTAG);
868 dmu_buf_will_dirty(dd->dd_dbuf, tx);
869 dd->dd_phys->dd_head_dataset_obj = dsobj;
875 dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname,
876 dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx)
878 dsl_pool_t *dp = pdd->dd_pool;
879 uint64_t dsobj, ddobj;
882 ASSERT(lastname[0] != '@');
884 ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx);
885 VERIFY(0 == dsl_dir_open_obj(dp, ddobj, lastname, FTAG, &dd));
887 dsobj = dsl_dataset_create_sync_dd(dd, origin, flags, tx);
889 dsl_deleg_set_create_perms(dd, tx, cr);
891 dsl_dir_close(dd, FTAG);
894 * If we are creating a clone, make sure we zero out any stale
895 * data from the origin snapshots zil header.
897 if (origin != NULL) {
901 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
902 VERIFY3U(0, ==, dmu_objset_from_ds(ds, &os));
903 bzero(&os->os_zil_header, sizeof (os->os_zil_header));
904 dsl_dataset_dirty(ds, tx);
905 dsl_dataset_rele(ds, FTAG);
912 dsl_sync_task_group_t *dstg;
919 dsl_snapshot_destroy_one(const char *name, void *arg)
921 struct destroyarg *da = arg;
926 dsname = kmem_asprintf("%s@%s", name, da->snapname);
927 err = dsl_dataset_own(dsname, B_TRUE, da->dstg, &ds);
930 struct dsl_ds_destroyarg *dsda;
932 dsl_dataset_make_exclusive(ds, da->dstg);
933 dsda = kmem_zalloc(sizeof (struct dsl_ds_destroyarg), KM_SLEEP);
935 dsda->defer = da->defer;
936 dsl_sync_task_create(da->dstg, dsl_dataset_destroy_check,
937 dsl_dataset_destroy_sync, dsda, da->dstg, 0);
938 } else if (err == ENOENT) {
941 (void) strcpy(da->failed, name);
947 * Destroy 'snapname' in all descendants of 'fsname'.
949 #pragma weak dmu_snapshots_destroy = dsl_snapshots_destroy
951 dsl_snapshots_destroy(char *fsname, char *snapname, boolean_t defer)
954 struct destroyarg da;
955 dsl_sync_task_t *dst;
958 err = spa_open(fsname, &spa, FTAG);
961 da.dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
962 da.snapname = snapname;
966 err = dmu_objset_find(fsname,
967 dsl_snapshot_destroy_one, &da, DS_FIND_CHILDREN);
970 err = dsl_sync_task_group_wait(da.dstg);
972 for (dst = list_head(&da.dstg->dstg_tasks); dst;
973 dst = list_next(&da.dstg->dstg_tasks, dst)) {
974 struct dsl_ds_destroyarg *dsda = dst->dst_arg1;
975 dsl_dataset_t *ds = dsda->ds;
978 * Return the file system name that triggered the error
981 dsl_dataset_name(ds, fsname);
982 *strchr(fsname, '@') = '\0';
984 ASSERT3P(dsda->rm_origin, ==, NULL);
985 dsl_dataset_disown(ds, da.dstg);
986 kmem_free(dsda, sizeof (struct dsl_ds_destroyarg));
989 dsl_sync_task_group_destroy(da.dstg);
990 spa_close(spa, FTAG);
995 dsl_dataset_might_destroy_origin(dsl_dataset_t *ds)
997 boolean_t might_destroy = B_FALSE;
999 mutex_enter(&ds->ds_lock);
1000 if (ds->ds_phys->ds_num_children == 2 && ds->ds_userrefs == 0 &&
1001 DS_IS_DEFER_DESTROY(ds))
1002 might_destroy = B_TRUE;
1003 mutex_exit(&ds->ds_lock);
1005 return (might_destroy);
1009 * If we're removing a clone, and these three conditions are true:
1010 * 1) the clone's origin has no other children
1011 * 2) the clone's origin has no user references
1012 * 3) the clone's origin has been marked for deferred destruction
1013 * Then, prepare to remove the origin as part of this sync task group.
1016 dsl_dataset_origin_rm_prep(struct dsl_ds_destroyarg *dsda, void *tag)
1018 dsl_dataset_t *ds = dsda->ds;
1019 dsl_dataset_t *origin = ds->ds_prev;
1021 if (dsl_dataset_might_destroy_origin(origin)) {
1026 namelen = dsl_dataset_namelen(origin) + 1;
1027 name = kmem_alloc(namelen, KM_SLEEP);
1028 dsl_dataset_name(origin, name);
1030 error = zfs_unmount_snap(name, NULL);
1032 kmem_free(name, namelen);
1036 error = dsl_dataset_own(name, B_TRUE, tag, &origin);
1037 kmem_free(name, namelen);
1040 dsda->rm_origin = origin;
1041 dsl_dataset_make_exclusive(origin, tag);
1048 * ds must be opened as OWNER. On return (whether successful or not),
1049 * ds will be closed and caller can no longer dereference it.
1052 dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer)
1055 dsl_sync_task_group_t *dstg;
1059 struct dsl_ds_destroyarg dsda = { 0 };
1060 dsl_dataset_t dummy_ds = { 0 };
1064 if (dsl_dataset_is_snapshot(ds)) {
1065 /* Destroying a snapshot is simpler */
1066 dsl_dataset_make_exclusive(ds, tag);
1069 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
1070 dsl_dataset_destroy_check, dsl_dataset_destroy_sync,
1072 ASSERT3P(dsda.rm_origin, ==, NULL);
1080 dummy_ds.ds_dir = dd;
1081 dummy_ds.ds_object = ds->ds_object;
1084 * Check for errors and mark this ds as inconsistent, in
1085 * case we crash while freeing the objects.
1087 err = dsl_sync_task_do(dd->dd_pool, dsl_dataset_destroy_begin_check,
1088 dsl_dataset_destroy_begin_sync, ds, NULL, 0);
1092 err = dmu_objset_from_ds(ds, &os);
1097 * remove the objects in open context, so that we won't
1098 * have too much to do in syncing context.
1100 for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE,
1101 ds->ds_phys->ds_prev_snap_txg)) {
1103 * Ignore errors, if there is not enough disk space
1104 * we will deal with it in dsl_dataset_destroy_sync().
1106 (void) dmu_free_object(os, obj);
1112 * Only the ZIL knows how to free log blocks.
1114 zil_destroy(dmu_objset_zil(os), B_FALSE);
1117 * Sync out all in-flight IO.
1119 txg_wait_synced(dd->dd_pool, 0);
1122 * If we managed to free all the objects in open
1123 * context, the user space accounting should be zero.
1125 if (ds->ds_phys->ds_bp.blk_fill == 0 &&
1126 dmu_objset_userused_enabled(os)) {
1129 ASSERT(zap_count(os, DMU_USERUSED_OBJECT, &count) != 0 ||
1131 ASSERT(zap_count(os, DMU_GROUPUSED_OBJECT, &count) != 0 ||
1135 rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
1136 err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd);
1137 rw_exit(&dd->dd_pool->dp_config_rwlock);
1143 * Blow away the dsl_dir + head dataset.
1145 dsl_dataset_make_exclusive(ds, tag);
1147 * If we're removing a clone, we might also need to remove its
1151 dsda.need_prep = B_FALSE;
1152 if (dsl_dir_is_clone(dd)) {
1153 err = dsl_dataset_origin_rm_prep(&dsda, tag);
1155 dsl_dir_close(dd, FTAG);
1160 dstg = dsl_sync_task_group_create(ds->ds_dir->dd_pool);
1161 dsl_sync_task_create(dstg, dsl_dataset_destroy_check,
1162 dsl_dataset_destroy_sync, &dsda, tag, 0);
1163 dsl_sync_task_create(dstg, dsl_dir_destroy_check,
1164 dsl_dir_destroy_sync, &dummy_ds, FTAG, 0);
1165 err = dsl_sync_task_group_wait(dstg);
1166 dsl_sync_task_group_destroy(dstg);
1169 * We could be racing against 'zfs release' or 'zfs destroy -d'
1170 * on the origin snap, in which case we can get EBUSY if we
1171 * needed to destroy the origin snap but were not ready to
1174 if (dsda.need_prep) {
1175 ASSERT(err == EBUSY);
1176 ASSERT(dsl_dir_is_clone(dd));
1177 ASSERT(dsda.rm_origin == NULL);
1179 } while (dsda.need_prep);
1181 if (dsda.rm_origin != NULL)
1182 dsl_dataset_disown(dsda.rm_origin, tag);
1184 /* if it is successful, dsl_dir_destroy_sync will close the dd */
1186 dsl_dir_close(dd, FTAG);
1188 dsl_dataset_disown(ds, tag);
1193 dsl_dataset_get_blkptr(dsl_dataset_t *ds)
1195 return (&ds->ds_phys->ds_bp);
1199 dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx)
1201 ASSERT(dmu_tx_is_syncing(tx));
1202 /* If it's the meta-objset, set dp_meta_rootbp */
1204 tx->tx_pool->dp_meta_rootbp = *bp;
1206 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1207 ds->ds_phys->ds_bp = *bp;
1212 dsl_dataset_get_spa(dsl_dataset_t *ds)
1214 return (ds->ds_dir->dd_pool->dp_spa);
1218 dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx)
1222 if (ds == NULL) /* this is the meta-objset */
1225 ASSERT(ds->ds_objset != NULL);
1227 if (ds->ds_phys->ds_next_snap_obj != 0)
1228 panic("dirtying snapshot!");
1230 dp = ds->ds_dir->dd_pool;
1232 if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg) == 0) {
1233 /* up the hold count until we can be written out */
1234 dmu_buf_add_ref(ds->ds_dbuf, ds);
1239 * The unique space in the head dataset can be calculated by subtracting
1240 * the space used in the most recent snapshot, that is still being used
1241 * in this file system, from the space currently in use. To figure out
1242 * the space in the most recent snapshot still in use, we need to take
1243 * the total space used in the snapshot and subtract out the space that
1244 * has been freed up since the snapshot was taken.
1247 dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds)
1250 uint64_t dlused, dlcomp, dluncomp;
1252 ASSERT(!dsl_dataset_is_snapshot(ds));
1254 if (ds->ds_phys->ds_prev_snap_obj != 0)
1255 mrs_used = ds->ds_prev->ds_phys->ds_used_bytes;
1259 dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp);
1261 ASSERT3U(dlused, <=, mrs_used);
1262 ds->ds_phys->ds_unique_bytes =
1263 ds->ds_phys->ds_used_bytes - (mrs_used - dlused);
1265 if (spa_version(ds->ds_dir->dd_pool->dp_spa) >=
1266 SPA_VERSION_UNIQUE_ACCURATE)
1267 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
1277 kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf,
1278 const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
1280 struct killarg *ka = arg;
1281 dmu_tx_t *tx = ka->tx;
1286 if (zb->zb_level == ZB_ZIL_LEVEL) {
1287 ASSERT(zilog != NULL);
1289 * It's a block in the intent log. It has no
1290 * accounting, so just free it.
1292 dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp);
1294 ASSERT(zilog == NULL);
1295 ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg);
1296 (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE);
1304 dsl_dataset_destroy_begin_check(void *arg1, void *arg2, dmu_tx_t *tx)
1306 dsl_dataset_t *ds = arg1;
1307 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1312 * Can't delete a head dataset if there are snapshots of it.
1313 * (Except if the only snapshots are from the branch we cloned
1316 if (ds->ds_prev != NULL &&
1317 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object)
1321 * This is really a dsl_dir thing, but check it here so that
1322 * we'll be less likely to leave this dataset inconsistent &
1325 err = zap_count(mos, ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count);
1336 dsl_dataset_destroy_begin_sync(void *arg1, void *arg2, dmu_tx_t *tx)
1338 dsl_dataset_t *ds = arg1;
1339 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1341 /* Mark it as inconsistent on-disk, in case we crash */
1342 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1343 ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT;
1345 spa_history_log_internal(LOG_DS_DESTROY_BEGIN, dp->dp_spa, tx,
1346 "dataset = %llu", ds->ds_object);
1350 dsl_dataset_origin_check(struct dsl_ds_destroyarg *dsda, void *tag,
1353 dsl_dataset_t *ds = dsda->ds;
1354 dsl_dataset_t *ds_prev = ds->ds_prev;
1356 if (dsl_dataset_might_destroy_origin(ds_prev)) {
1357 struct dsl_ds_destroyarg ndsda = {0};
1360 * If we're not prepared to remove the origin, don't remove
1363 if (dsda->rm_origin == NULL) {
1364 dsda->need_prep = B_TRUE;
1369 ndsda.is_origin_rm = B_TRUE;
1370 return (dsl_dataset_destroy_check(&ndsda, tag, tx));
1374 * If we're not going to remove the origin after all,
1375 * undo the open context setup.
1377 if (dsda->rm_origin != NULL) {
1378 dsl_dataset_disown(dsda->rm_origin, tag);
1379 dsda->rm_origin = NULL;
1386 * If you add new checks here, you may need to add
1387 * additional checks to the "temporary" case in
1388 * snapshot_check() in dmu_objset.c.
1392 dsl_dataset_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx)
1394 struct dsl_ds_destroyarg *dsda = arg1;
1395 dsl_dataset_t *ds = dsda->ds;
1397 /* we have an owner hold, so noone else can destroy us */
1398 ASSERT(!DSL_DATASET_IS_DESTROYED(ds));
1401 * Only allow deferred destroy on pools that support it.
1402 * NOTE: deferred destroy is only supported on snapshots.
1405 if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
1406 SPA_VERSION_USERREFS)
1408 ASSERT(dsl_dataset_is_snapshot(ds));
1413 * Can't delete a head dataset if there are snapshots of it.
1414 * (Except if the only snapshots are from the branch we cloned
1417 if (ds->ds_prev != NULL &&
1418 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object)
1422 * If we made changes this txg, traverse_dsl_dataset won't find
1425 if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg)
1428 if (dsl_dataset_is_snapshot(ds)) {
1430 * If this snapshot has an elevated user reference count,
1431 * we can't destroy it yet.
1433 if (ds->ds_userrefs > 0 && !dsda->releasing)
1436 mutex_enter(&ds->ds_lock);
1438 * Can't delete a branch point. However, if we're destroying
1439 * a clone and removing its origin due to it having a user
1440 * hold count of 0 and having been marked for deferred destroy,
1441 * it's OK for the origin to have a single clone.
1443 if (ds->ds_phys->ds_num_children >
1444 (dsda->is_origin_rm ? 2 : 1)) {
1445 mutex_exit(&ds->ds_lock);
1448 mutex_exit(&ds->ds_lock);
1449 } else if (dsl_dir_is_clone(ds->ds_dir)) {
1450 return (dsl_dataset_origin_check(dsda, arg2, tx));
1453 /* XXX we should do some i/o error checking... */
1465 dsl_dataset_refs_gone(dmu_buf_t *db, void *argv)
1467 struct refsarg *arg = argv;
1469 mutex_enter(&arg->lock);
1471 cv_signal(&arg->cv);
1472 mutex_exit(&arg->lock);
1476 dsl_dataset_drain_refs(dsl_dataset_t *ds, void *tag)
1480 bzero(&arg, sizeof(arg));
1481 mutex_init(&arg.lock, NULL, MUTEX_DEFAULT, NULL);
1482 cv_init(&arg.cv, NULL, CV_DEFAULT, NULL);
1484 (void) dmu_buf_update_user(ds->ds_dbuf, ds, &arg, &ds->ds_phys,
1485 dsl_dataset_refs_gone);
1486 dmu_buf_rele(ds->ds_dbuf, tag);
1487 mutex_enter(&arg.lock);
1489 cv_wait(&arg.cv, &arg.lock);
1491 mutex_exit(&arg.lock);
1494 mutex_destroy(&arg.lock);
1495 cv_destroy(&arg.cv);
1499 remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj, dmu_tx_t *tx)
1501 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1505 ASSERT(ds->ds_phys->ds_num_children >= 2);
1506 err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx);
1508 * The err should not be ENOENT, but a bug in a previous version
1509 * of the code could cause upgrade_clones_cb() to not set
1510 * ds_next_snap_obj when it should, leading to a missing entry.
1511 * If we knew that the pool was created after
1512 * SPA_VERSION_NEXT_CLONES, we could assert that it isn't
1513 * ENOENT. However, at least we can check that we don't have
1514 * too many entries in the next_clones_obj even after failing to
1517 if (err != ENOENT) {
1518 VERIFY3U(err, ==, 0);
1520 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj,
1522 ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2);
1526 dsl_dataset_remove_clones_key(dsl_dataset_t *ds, uint64_t mintxg, dmu_tx_t *tx)
1528 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1533 * If it is the old version, dd_clones doesn't exist so we can't
1534 * find the clones, but deadlist_remove_key() is a no-op so it
1537 if (ds->ds_dir->dd_phys->dd_clones == 0)
1540 for (zap_cursor_init(&zc, mos, ds->ds_dir->dd_phys->dd_clones);
1541 zap_cursor_retrieve(&zc, &za) == 0;
1542 zap_cursor_advance(&zc)) {
1543 dsl_dataset_t *clone;
1545 VERIFY3U(0, ==, dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
1546 za.za_first_integer, FTAG, &clone));
1547 if (clone->ds_dir->dd_origin_txg > mintxg) {
1548 dsl_deadlist_remove_key(&clone->ds_deadlist,
1550 dsl_dataset_remove_clones_key(clone, mintxg, tx);
1552 dsl_dataset_rele(clone, FTAG);
1554 zap_cursor_fini(&zc);
1557 struct process_old_arg {
1559 dsl_dataset_t *ds_prev;
1560 boolean_t after_branch_point;
1562 uint64_t used, comp, uncomp;
1566 process_old_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
1568 struct process_old_arg *poa = arg;
1569 dsl_pool_t *dp = poa->ds->ds_dir->dd_pool;
1571 if (bp->blk_birth <= poa->ds->ds_phys->ds_prev_snap_txg) {
1572 dsl_deadlist_insert(&poa->ds->ds_deadlist, bp, tx);
1573 if (poa->ds_prev && !poa->after_branch_point &&
1575 poa->ds_prev->ds_phys->ds_prev_snap_txg) {
1576 poa->ds_prev->ds_phys->ds_unique_bytes +=
1577 bp_get_dsize_sync(dp->dp_spa, bp);
1580 poa->used += bp_get_dsize_sync(dp->dp_spa, bp);
1581 poa->comp += BP_GET_PSIZE(bp);
1582 poa->uncomp += BP_GET_UCSIZE(bp);
1583 dsl_free_sync(poa->pio, dp, tx->tx_txg, bp);
1589 process_old_deadlist(dsl_dataset_t *ds, dsl_dataset_t *ds_prev,
1590 dsl_dataset_t *ds_next, boolean_t after_branch_point, dmu_tx_t *tx)
1592 struct process_old_arg poa = { 0 };
1593 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1594 objset_t *mos = dp->dp_meta_objset;
1596 ASSERT(ds->ds_deadlist.dl_oldfmt);
1597 ASSERT(ds_next->ds_deadlist.dl_oldfmt);
1600 poa.ds_prev = ds_prev;
1601 poa.after_branch_point = after_branch_point;
1602 poa.pio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
1603 VERIFY3U(0, ==, bpobj_iterate(&ds_next->ds_deadlist.dl_bpobj,
1604 process_old_cb, &poa, tx));
1605 VERIFY3U(zio_wait(poa.pio), ==, 0);
1606 ASSERT3U(poa.used, ==, ds->ds_phys->ds_unique_bytes);
1608 /* change snapused */
1609 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
1610 -poa.used, -poa.comp, -poa.uncomp, tx);
1612 /* swap next's deadlist to our deadlist */
1613 dsl_deadlist_close(&ds->ds_deadlist);
1614 dsl_deadlist_close(&ds_next->ds_deadlist);
1615 SWITCH64(ds_next->ds_phys->ds_deadlist_obj,
1616 ds->ds_phys->ds_deadlist_obj);
1617 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj);
1618 dsl_deadlist_open(&ds_next->ds_deadlist, mos,
1619 ds_next->ds_phys->ds_deadlist_obj);
1623 dsl_dataset_destroy_sync(void *arg1, void *tag, dmu_tx_t *tx)
1625 struct dsl_ds_destroyarg *dsda = arg1;
1626 dsl_dataset_t *ds = dsda->ds;
1628 int after_branch_point = FALSE;
1629 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1630 objset_t *mos = dp->dp_meta_objset;
1631 dsl_dataset_t *ds_prev = NULL;
1632 boolean_t wont_destroy;
1635 wont_destroy = (dsda->defer &&
1636 (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1));
1638 ASSERT(ds->ds_owner || wont_destroy);
1639 ASSERT(dsda->defer || ds->ds_phys->ds_num_children <= 1);
1640 ASSERT(ds->ds_prev == NULL ||
1641 ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object);
1642 ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg);
1645 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
1646 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1647 ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY;
1651 /* signal any waiters that this dataset is going away */
1652 mutex_enter(&ds->ds_lock);
1653 ds->ds_owner = dsl_reaper;
1654 cv_broadcast(&ds->ds_exclusive_cv);
1655 mutex_exit(&ds->ds_lock);
1657 /* Remove our reservation */
1658 if (ds->ds_reserved != 0) {
1659 dsl_prop_setarg_t psa;
1662 dsl_prop_setarg_init_uint64(&psa, "refreservation",
1663 (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED),
1665 psa.psa_effective_value = 0; /* predict default value */
1667 dsl_dataset_set_reservation_sync(ds, &psa, tx);
1668 ASSERT3U(ds->ds_reserved, ==, 0);
1671 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
1673 dsl_scan_ds_destroyed(ds, tx);
1675 obj = ds->ds_object;
1677 if (ds->ds_phys->ds_prev_snap_obj != 0) {
1679 ds_prev = ds->ds_prev;
1681 VERIFY(0 == dsl_dataset_hold_obj(dp,
1682 ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev));
1684 after_branch_point =
1685 (ds_prev->ds_phys->ds_next_snap_obj != obj);
1687 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx);
1688 if (after_branch_point &&
1689 ds_prev->ds_phys->ds_next_clones_obj != 0) {
1690 remove_from_next_clones(ds_prev, obj, tx);
1691 if (ds->ds_phys->ds_next_snap_obj != 0) {
1692 VERIFY(0 == zap_add_int(mos,
1693 ds_prev->ds_phys->ds_next_clones_obj,
1694 ds->ds_phys->ds_next_snap_obj, tx));
1697 if (after_branch_point &&
1698 ds->ds_phys->ds_next_snap_obj == 0) {
1699 /* This clone is toast. */
1700 ASSERT(ds_prev->ds_phys->ds_num_children > 1);
1701 ds_prev->ds_phys->ds_num_children--;
1704 * If the clone's origin has no other clones, no
1705 * user holds, and has been marked for deferred
1706 * deletion, then we should have done the necessary
1707 * destroy setup for it.
1709 if (ds_prev->ds_phys->ds_num_children == 1 &&
1710 ds_prev->ds_userrefs == 0 &&
1711 DS_IS_DEFER_DESTROY(ds_prev)) {
1712 ASSERT3P(dsda->rm_origin, !=, NULL);
1714 ASSERT3P(dsda->rm_origin, ==, NULL);
1716 } else if (!after_branch_point) {
1717 ds_prev->ds_phys->ds_next_snap_obj =
1718 ds->ds_phys->ds_next_snap_obj;
1722 if (dsl_dataset_is_snapshot(ds)) {
1723 dsl_dataset_t *ds_next;
1724 uint64_t old_unique;
1725 uint64_t used = 0, comp = 0, uncomp = 0;
1727 VERIFY(0 == dsl_dataset_hold_obj(dp,
1728 ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next));
1729 ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj);
1731 old_unique = ds_next->ds_phys->ds_unique_bytes;
1733 dmu_buf_will_dirty(ds_next->ds_dbuf, tx);
1734 ds_next->ds_phys->ds_prev_snap_obj =
1735 ds->ds_phys->ds_prev_snap_obj;
1736 ds_next->ds_phys->ds_prev_snap_txg =
1737 ds->ds_phys->ds_prev_snap_txg;
1738 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
1739 ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0);
1742 if (ds_next->ds_deadlist.dl_oldfmt) {
1743 process_old_deadlist(ds, ds_prev, ds_next,
1744 after_branch_point, tx);
1746 /* Adjust prev's unique space. */
1747 if (ds_prev && !after_branch_point) {
1748 dsl_deadlist_space_range(&ds_next->ds_deadlist,
1749 ds_prev->ds_phys->ds_prev_snap_txg,
1750 ds->ds_phys->ds_prev_snap_txg,
1751 &used, &comp, &uncomp);
1752 ds_prev->ds_phys->ds_unique_bytes += used;
1755 /* Adjust snapused. */
1756 dsl_deadlist_space_range(&ds_next->ds_deadlist,
1757 ds->ds_phys->ds_prev_snap_txg, UINT64_MAX,
1758 &used, &comp, &uncomp);
1759 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
1760 -used, -comp, -uncomp, tx);
1762 /* Move blocks to be freed to pool's free list. */
1763 dsl_deadlist_move_bpobj(&ds_next->ds_deadlist,
1764 &dp->dp_free_bpobj, ds->ds_phys->ds_prev_snap_txg,
1766 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir,
1767 DD_USED_HEAD, used, comp, uncomp, tx);
1768 dsl_dir_dirty(tx->tx_pool->dp_free_dir, tx);
1770 /* Merge our deadlist into next's and free it. */
1771 dsl_deadlist_merge(&ds_next->ds_deadlist,
1772 ds->ds_phys->ds_deadlist_obj, tx);
1774 dsl_deadlist_close(&ds->ds_deadlist);
1775 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx);
1777 /* Collapse range in clone heads */
1778 dsl_dataset_remove_clones_key(ds,
1779 ds->ds_phys->ds_creation_txg, tx);
1781 if (dsl_dataset_is_snapshot(ds_next)) {
1782 dsl_dataset_t *ds_nextnext;
1785 * Update next's unique to include blocks which
1786 * were previously shared by only this snapshot
1787 * and it. Those blocks will be born after the
1788 * prev snap and before this snap, and will have
1789 * died after the next snap and before the one
1790 * after that (ie. be on the snap after next's
1793 VERIFY(0 == dsl_dataset_hold_obj(dp,
1794 ds_next->ds_phys->ds_next_snap_obj,
1795 FTAG, &ds_nextnext));
1796 dsl_deadlist_space_range(&ds_nextnext->ds_deadlist,
1797 ds->ds_phys->ds_prev_snap_txg,
1798 ds->ds_phys->ds_creation_txg,
1799 &used, &comp, &uncomp);
1800 ds_next->ds_phys->ds_unique_bytes += used;
1801 dsl_dataset_rele(ds_nextnext, FTAG);
1802 ASSERT3P(ds_next->ds_prev, ==, NULL);
1804 /* Collapse range in this head. */
1806 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
1807 ds->ds_dir->dd_phys->dd_head_dataset_obj,
1809 dsl_deadlist_remove_key(&hds->ds_deadlist,
1810 ds->ds_phys->ds_creation_txg, tx);
1811 dsl_dataset_rele(hds, FTAG);
1814 ASSERT3P(ds_next->ds_prev, ==, ds);
1815 dsl_dataset_drop_ref(ds_next->ds_prev, ds_next);
1816 ds_next->ds_prev = NULL;
1818 VERIFY(0 == dsl_dataset_get_ref(dp,
1819 ds->ds_phys->ds_prev_snap_obj,
1820 ds_next, &ds_next->ds_prev));
1823 dsl_dataset_recalc_head_uniq(ds_next);
1826 * Reduce the amount of our unconsmed refreservation
1827 * being charged to our parent by the amount of
1828 * new unique data we have gained.
1830 if (old_unique < ds_next->ds_reserved) {
1832 uint64_t new_unique =
1833 ds_next->ds_phys->ds_unique_bytes;
1835 ASSERT(old_unique <= new_unique);
1836 mrsdelta = MIN(new_unique - old_unique,
1837 ds_next->ds_reserved - old_unique);
1838 dsl_dir_diduse_space(ds->ds_dir,
1839 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx);
1842 dsl_dataset_rele(ds_next, FTAG);
1845 * There's no next snapshot, so this is a head dataset.
1846 * Destroy the deadlist. Unless it's a clone, the
1847 * deadlist should be empty. (If it's a clone, it's
1848 * safe to ignore the deadlist contents.)
1852 dsl_deadlist_close(&ds->ds_deadlist);
1853 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx);
1854 ds->ds_phys->ds_deadlist_obj = 0;
1857 * Free everything that we point to (that's born after
1858 * the previous snapshot, if we are a clone)
1860 * NB: this should be very quick, because we already
1861 * freed all the objects in open context.
1865 err = traverse_dataset(ds, ds->ds_phys->ds_prev_snap_txg,
1866 TRAVERSE_POST, kill_blkptr, &ka);
1867 ASSERT3U(err, ==, 0);
1868 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) ||
1869 ds->ds_phys->ds_unique_bytes == 0);
1871 if (ds->ds_prev != NULL) {
1872 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
1873 VERIFY3U(0, ==, zap_remove_int(mos,
1874 ds->ds_prev->ds_dir->dd_phys->dd_clones,
1875 ds->ds_object, tx));
1877 dsl_dataset_rele(ds->ds_prev, ds);
1878 ds->ds_prev = ds_prev = NULL;
1883 * This must be done after the dsl_traverse(), because it will
1884 * re-open the objset.
1886 if (ds->ds_objset) {
1887 dmu_objset_evict(ds->ds_objset);
1888 ds->ds_objset = NULL;
1891 if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) {
1892 /* Erase the link in the dir */
1893 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx);
1894 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0;
1895 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0);
1896 err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx);
1899 /* remove from snapshot namespace */
1900 dsl_dataset_t *ds_head;
1901 ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0);
1902 VERIFY(0 == dsl_dataset_hold_obj(dp,
1903 ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head));
1904 VERIFY(0 == dsl_dataset_get_snapname(ds));
1909 err = dsl_dataset_snap_lookup(ds_head,
1910 ds->ds_snapname, &val);
1911 ASSERT3U(err, ==, 0);
1912 ASSERT3U(val, ==, obj);
1915 err = dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx);
1917 dsl_dataset_rele(ds_head, FTAG);
1920 if (ds_prev && ds->ds_prev != ds_prev)
1921 dsl_dataset_rele(ds_prev, FTAG);
1923 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx);
1924 spa_history_log_internal(LOG_DS_DESTROY, dp->dp_spa, tx,
1925 "dataset = %llu", ds->ds_object);
1927 if (ds->ds_phys->ds_next_clones_obj != 0) {
1929 ASSERT(0 == zap_count(mos,
1930 ds->ds_phys->ds_next_clones_obj, &count) && count == 0);
1931 VERIFY(0 == dmu_object_free(mos,
1932 ds->ds_phys->ds_next_clones_obj, tx));
1934 if (ds->ds_phys->ds_props_obj != 0)
1935 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_props_obj, tx));
1936 if (ds->ds_phys->ds_userrefs_obj != 0)
1937 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx));
1938 dsl_dir_close(ds->ds_dir, ds);
1940 dsl_dataset_drain_refs(ds, tag);
1941 VERIFY(0 == dmu_object_free(mos, obj, tx));
1943 if (dsda->rm_origin) {
1945 * Remove the origin of the clone we just destroyed.
1947 struct dsl_ds_destroyarg ndsda = {0};
1949 ndsda.ds = dsda->rm_origin;
1950 dsl_dataset_destroy_sync(&ndsda, tag, tx);
1955 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx)
1959 if (!dmu_tx_is_syncing(tx))
1963 * If there's an fs-only reservation, any blocks that might become
1964 * owned by the snapshot dataset must be accommodated by space
1965 * outside of the reservation.
1967 ASSERT(ds->ds_reserved == 0 || DS_UNIQUE_IS_ACCURATE(ds));
1968 asize = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
1969 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
1973 * Propogate any reserved space for this snapshot to other
1974 * snapshot checks in this sync group.
1977 dsl_dir_willuse_space(ds->ds_dir, asize, tx);
1983 dsl_dataset_snapshot_check(void *arg1, void *arg2, dmu_tx_t *tx)
1985 dsl_dataset_t *ds = arg1;
1986 const char *snapname = arg2;
1991 * We don't allow multiple snapshots of the same txg. If there
1992 * is already one, try again.
1994 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg)
1998 * Check for conflicting name snapshot name.
2000 err = dsl_dataset_snap_lookup(ds, snapname, &value);
2007 * Check that the dataset's name is not too long. Name consists
2008 * of the dataset's length + 1 for the @-sign + snapshot name's length
2010 if (dsl_dataset_namelen(ds) + 1 + strlen(snapname) >= MAXNAMELEN)
2011 return (ENAMETOOLONG);
2013 err = dsl_dataset_snapshot_reserve_space(ds, tx);
2017 ds->ds_trysnap_txg = tx->tx_txg;
2022 dsl_dataset_snapshot_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2024 dsl_dataset_t *ds = arg1;
2025 const char *snapname = arg2;
2026 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2028 dsl_dataset_phys_t *dsphys;
2029 uint64_t dsobj, crtxg;
2030 objset_t *mos = dp->dp_meta_objset;
2033 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
2036 * The origin's ds_creation_txg has to be < TXG_INITIAL
2038 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0)
2043 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
2044 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
2045 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
2046 dmu_buf_will_dirty(dbuf, tx);
2047 dsphys = dbuf->db_data;
2048 bzero(dsphys, sizeof (dsl_dataset_phys_t));
2049 dsphys->ds_dir_obj = ds->ds_dir->dd_object;
2050 dsphys->ds_fsid_guid = unique_create();
2051 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
2052 sizeof (dsphys->ds_guid));
2053 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj;
2054 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg;
2055 dsphys->ds_next_snap_obj = ds->ds_object;
2056 dsphys->ds_num_children = 1;
2057 dsphys->ds_creation_time = gethrestime_sec();
2058 dsphys->ds_creation_txg = crtxg;
2059 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj;
2060 dsphys->ds_used_bytes = ds->ds_phys->ds_used_bytes;
2061 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes;
2062 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes;
2063 dsphys->ds_flags = ds->ds_phys->ds_flags;
2064 dsphys->ds_bp = ds->ds_phys->ds_bp;
2065 dmu_buf_rele(dbuf, FTAG);
2067 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0);
2069 uint64_t next_clones_obj =
2070 ds->ds_prev->ds_phys->ds_next_clones_obj;
2071 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj ==
2073 ds->ds_prev->ds_phys->ds_num_children > 1);
2074 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) {
2075 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
2076 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
2077 ds->ds_prev->ds_phys->ds_creation_txg);
2078 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj;
2079 } else if (next_clones_obj != 0) {
2080 remove_from_next_clones(ds->ds_prev,
2081 dsphys->ds_next_snap_obj, tx);
2082 VERIFY3U(0, ==, zap_add_int(mos,
2083 next_clones_obj, dsobj, tx));
2088 * If we have a reference-reservation on this dataset, we will
2089 * need to increase the amount of refreservation being charged
2090 * since our unique space is going to zero.
2092 if (ds->ds_reserved) {
2094 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
2095 delta = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
2096 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV,
2100 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2101 zfs_dbgmsg("taking snapshot %s@%s/%llu; newkey=%llu",
2102 ds->ds_dir->dd_myname, snapname, dsobj,
2103 ds->ds_phys->ds_prev_snap_txg);
2104 ds->ds_phys->ds_deadlist_obj = dsl_deadlist_clone(&ds->ds_deadlist,
2105 UINT64_MAX, ds->ds_phys->ds_prev_snap_obj, tx);
2106 dsl_deadlist_close(&ds->ds_deadlist);
2107 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj);
2108 dsl_deadlist_add_key(&ds->ds_deadlist,
2109 ds->ds_phys->ds_prev_snap_txg, tx);
2111 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg);
2112 ds->ds_phys->ds_prev_snap_obj = dsobj;
2113 ds->ds_phys->ds_prev_snap_txg = crtxg;
2114 ds->ds_phys->ds_unique_bytes = 0;
2115 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
2116 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
2118 err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj,
2119 snapname, 8, 1, &dsobj, tx);
2123 dsl_dataset_drop_ref(ds->ds_prev, ds);
2124 VERIFY(0 == dsl_dataset_get_ref(dp,
2125 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev));
2127 dsl_scan_ds_snapshotted(ds, tx);
2129 dsl_dir_snap_cmtime_update(ds->ds_dir);
2131 spa_history_log_internal(LOG_DS_SNAPSHOT, dp->dp_spa, tx,
2132 "dataset = %llu", dsobj);
2136 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx)
2138 ASSERT(dmu_tx_is_syncing(tx));
2139 ASSERT(ds->ds_objset != NULL);
2140 ASSERT(ds->ds_phys->ds_next_snap_obj == 0);
2143 * in case we had to change ds_fsid_guid when we opened it,
2146 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2147 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid;
2149 dsl_dir_dirty(ds->ds_dir, tx);
2150 dmu_objset_sync(ds->ds_objset, zio, tx);
2154 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv)
2156 uint64_t refd, avail, uobjs, aobjs, ratio;
2158 dsl_dir_stats(ds->ds_dir, nv);
2160 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs);
2161 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail);
2162 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd);
2164 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION,
2165 ds->ds_phys->ds_creation_time);
2166 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG,
2167 ds->ds_phys->ds_creation_txg);
2168 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA,
2170 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION,
2172 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID,
2173 ds->ds_phys->ds_guid);
2174 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE,
2175 ds->ds_phys->ds_unique_bytes);
2176 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID,
2178 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS,
2180 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY,
2181 DS_IS_DEFER_DESTROY(ds) ? 1 : 0);
2183 ratio = ds->ds_phys->ds_compressed_bytes == 0 ? 100 :
2184 (ds->ds_phys->ds_uncompressed_bytes * 100 /
2185 ds->ds_phys->ds_compressed_bytes);
2186 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRATIO, ratio);
2188 if (ds->ds_phys->ds_next_snap_obj) {
2190 * This is a snapshot; override the dd's space used with
2191 * our unique space and compression ratio.
2193 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED,
2194 ds->ds_phys->ds_unique_bytes);
2195 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, ratio);
2200 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat)
2202 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg;
2203 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT;
2204 stat->dds_guid = ds->ds_phys->ds_guid;
2205 if (ds->ds_phys->ds_next_snap_obj) {
2206 stat->dds_is_snapshot = B_TRUE;
2207 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1;
2209 stat->dds_is_snapshot = B_FALSE;
2210 stat->dds_num_clones = 0;
2213 /* clone origin is really a dsl_dir thing... */
2214 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER);
2215 if (dsl_dir_is_clone(ds->ds_dir)) {
2218 VERIFY(0 == dsl_dataset_get_ref(ds->ds_dir->dd_pool,
2219 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods));
2220 dsl_dataset_name(ods, stat->dds_origin);
2221 dsl_dataset_drop_ref(ods, FTAG);
2223 stat->dds_origin[0] = '\0';
2225 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock);
2229 dsl_dataset_fsid_guid(dsl_dataset_t *ds)
2231 return (ds->ds_fsid_guid);
2235 dsl_dataset_space(dsl_dataset_t *ds,
2236 uint64_t *refdbytesp, uint64_t *availbytesp,
2237 uint64_t *usedobjsp, uint64_t *availobjsp)
2239 *refdbytesp = ds->ds_phys->ds_used_bytes;
2240 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE);
2241 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes)
2242 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes;
2243 if (ds->ds_quota != 0) {
2245 * Adjust available bytes according to refquota
2247 if (*refdbytesp < ds->ds_quota)
2248 *availbytesp = MIN(*availbytesp,
2249 ds->ds_quota - *refdbytesp);
2253 *usedobjsp = ds->ds_phys->ds_bp.blk_fill;
2254 *availobjsp = DN_MAX_OBJECT - *usedobjsp;
2258 dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds)
2260 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2262 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) ||
2263 dsl_pool_sync_context(dp));
2264 if (ds->ds_prev == NULL)
2266 if (ds->ds_phys->ds_bp.blk_birth >
2267 ds->ds_prev->ds_phys->ds_creation_txg) {
2268 objset_t *os, *os_prev;
2270 * It may be that only the ZIL differs, because it was
2271 * reset in the head. Don't count that as being
2274 if (dmu_objset_from_ds(ds, &os) != 0)
2276 if (dmu_objset_from_ds(ds->ds_prev, &os_prev) != 0)
2278 return (bcmp(&os->os_phys->os_meta_dnode,
2279 &os_prev->os_phys->os_meta_dnode,
2280 sizeof (os->os_phys->os_meta_dnode)) != 0);
2287 dsl_dataset_snapshot_rename_check(void *arg1, void *arg2, dmu_tx_t *tx)
2289 dsl_dataset_t *ds = arg1;
2290 char *newsnapname = arg2;
2291 dsl_dir_t *dd = ds->ds_dir;
2296 err = dsl_dataset_hold_obj(dd->dd_pool,
2297 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds);
2301 /* new name better not be in use */
2302 err = dsl_dataset_snap_lookup(hds, newsnapname, &val);
2303 dsl_dataset_rele(hds, FTAG);
2307 else if (err == ENOENT)
2310 /* dataset name + 1 for the "@" + the new snapshot name must fit */
2311 if (dsl_dir_namelen(ds->ds_dir) + 1 + strlen(newsnapname) >= MAXNAMELEN)
2318 dsl_dataset_snapshot_rename_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2320 char oldname[MAXPATHLEN], newname[MAXPATHLEN];
2321 dsl_dataset_t *ds = arg1;
2322 const char *newsnapname = arg2;
2323 dsl_dir_t *dd = ds->ds_dir;
2324 objset_t *mos = dd->dd_pool->dp_meta_objset;
2328 ASSERT(ds->ds_phys->ds_next_snap_obj != 0);
2330 VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool,
2331 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds));
2333 VERIFY(0 == dsl_dataset_get_snapname(ds));
2334 err = dsl_dataset_snap_remove(hds, ds->ds_snapname, tx);
2335 ASSERT3U(err, ==, 0);
2336 dsl_dataset_name(ds, oldname);
2337 mutex_enter(&ds->ds_lock);
2338 (void) strcpy(ds->ds_snapname, newsnapname);
2339 mutex_exit(&ds->ds_lock);
2340 err = zap_add(mos, hds->ds_phys->ds_snapnames_zapobj,
2341 ds->ds_snapname, 8, 1, &ds->ds_object, tx);
2342 ASSERT3U(err, ==, 0);
2343 dsl_dataset_name(ds, newname);
2345 zvol_rename_minors(oldname, newname);
2348 spa_history_log_internal(LOG_DS_RENAME, dd->dd_pool->dp_spa, tx,
2349 "dataset = %llu", ds->ds_object);
2350 dsl_dataset_rele(hds, FTAG);
2353 struct renamesnaparg {
2354 dsl_sync_task_group_t *dstg;
2355 char failed[MAXPATHLEN];
2361 dsl_snapshot_rename_one(const char *name, void *arg)
2363 struct renamesnaparg *ra = arg;
2364 dsl_dataset_t *ds = NULL;
2368 snapname = kmem_asprintf("%s@%s", name, ra->oldsnap);
2369 (void) strlcpy(ra->failed, snapname, sizeof (ra->failed));
2372 * For recursive snapshot renames the parent won't be changing
2373 * so we just pass name for both the to/from argument.
2375 err = zfs_secpolicy_rename_perms(snapname, snapname, CRED());
2378 return (err == ENOENT ? 0 : err);
2383 * For all filesystems undergoing rename, we'll need to unmount it.
2385 (void) zfs_unmount_snap(snapname, NULL);
2387 err = dsl_dataset_hold(snapname, ra->dstg, &ds);
2390 return (err == ENOENT ? 0 : err);
2392 dsl_sync_task_create(ra->dstg, dsl_dataset_snapshot_rename_check,
2393 dsl_dataset_snapshot_rename_sync, ds, ra->newsnap, 0);
2399 dsl_recursive_rename(char *oldname, const char *newname)
2402 struct renamesnaparg *ra;
2403 dsl_sync_task_t *dst;
2405 char *cp, *fsname = spa_strdup(oldname);
2406 int len = strlen(oldname) + 1;
2408 /* truncate the snapshot name to get the fsname */
2409 cp = strchr(fsname, '@');
2412 err = spa_open(fsname, &spa, FTAG);
2414 kmem_free(fsname, len);
2417 ra = kmem_alloc(sizeof (struct renamesnaparg), KM_SLEEP);
2418 ra->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
2420 ra->oldsnap = strchr(oldname, '@') + 1;
2421 ra->newsnap = strchr(newname, '@') + 1;
2424 err = dmu_objset_find(fsname, dsl_snapshot_rename_one, ra,
2426 kmem_free(fsname, len);
2429 err = dsl_sync_task_group_wait(ra->dstg);
2432 for (dst = list_head(&ra->dstg->dstg_tasks); dst;
2433 dst = list_next(&ra->dstg->dstg_tasks, dst)) {
2434 dsl_dataset_t *ds = dst->dst_arg1;
2436 dsl_dir_name(ds->ds_dir, ra->failed);
2437 (void) strlcat(ra->failed, "@", sizeof (ra->failed));
2438 (void) strlcat(ra->failed, ra->newsnap,
2439 sizeof (ra->failed));
2441 dsl_dataset_rele(ds, ra->dstg);
2445 (void) strlcpy(oldname, ra->failed, sizeof (ra->failed));
2447 dsl_sync_task_group_destroy(ra->dstg);
2448 kmem_free(ra, sizeof (struct renamesnaparg));
2449 spa_close(spa, FTAG);
2454 dsl_valid_rename(const char *oldname, void *arg)
2456 int delta = *(int *)arg;
2458 if (strlen(oldname) + delta >= MAXNAMELEN)
2459 return (ENAMETOOLONG);
2464 #pragma weak dmu_objset_rename = dsl_dataset_rename
2466 dsl_dataset_rename(char *oldname, const char *newname, int flags)
2473 err = dsl_dir_open(oldname, FTAG, &dd, &tail);
2478 int delta = strlen(newname) - strlen(oldname);
2480 /* if we're growing, validate child name lengths */
2482 err = dmu_objset_find(oldname, dsl_valid_rename,
2483 &delta, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS);
2486 err = dsl_dir_rename(dd, newname, flags);
2487 dsl_dir_close(dd, FTAG);
2491 if (tail[0] != '@') {
2492 /* the name ended in a nonexistent component */
2493 dsl_dir_close(dd, FTAG);
2497 dsl_dir_close(dd, FTAG);
2499 /* new name must be snapshot in same filesystem */
2500 tail = strchr(newname, '@');
2504 if (strncmp(oldname, newname, tail - newname) != 0)
2507 if (flags & ZFS_RENAME_RECURSIVE) {
2508 err = dsl_recursive_rename(oldname, newname);
2510 err = dsl_dataset_hold(oldname, FTAG, &ds);
2514 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
2515 dsl_dataset_snapshot_rename_check,
2516 dsl_dataset_snapshot_rename_sync, ds, (char *)tail, 1);
2518 dsl_dataset_rele(ds, FTAG);
2524 struct promotenode {
2530 list_t shared_snaps, origin_snaps, clone_snaps;
2531 dsl_dataset_t *origin_origin;
2532 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap;
2536 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep);
2537 static boolean_t snaplist_unstable(list_t *l);
2540 dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx)
2542 dsl_dataset_t *hds = arg1;
2543 struct promotearg *pa = arg2;
2544 struct promotenode *snap = list_head(&pa->shared_snaps);
2545 dsl_dataset_t *origin_ds = snap->ds;
2549 /* Check that it is a real clone */
2550 if (!dsl_dir_is_clone(hds->ds_dir))
2553 /* Since this is so expensive, don't do the preliminary check */
2554 if (!dmu_tx_is_syncing(tx))
2557 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE)
2560 /* compute origin's new unique space */
2561 snap = list_tail(&pa->clone_snaps);
2562 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2563 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2564 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX,
2565 &pa->unique, &unused, &unused);
2568 * Walk the snapshots that we are moving
2570 * Compute space to transfer. Consider the incremental changes
2571 * to used for each snapshot:
2572 * (my used) = (prev's used) + (blocks born) - (blocks killed)
2573 * So each snapshot gave birth to:
2574 * (blocks born) = (my used) - (prev's used) + (blocks killed)
2575 * So a sequence would look like:
2576 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0)
2577 * Which simplifies to:
2578 * uN + kN + kN-1 + ... + k1 + k0
2579 * Note however, if we stop before we reach the ORIGIN we get:
2580 * uN + kN + kN-1 + ... + kM - uM-1
2582 pa->used = origin_ds->ds_phys->ds_used_bytes;
2583 pa->comp = origin_ds->ds_phys->ds_compressed_bytes;
2584 pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes;
2585 for (snap = list_head(&pa->shared_snaps); snap;
2586 snap = list_next(&pa->shared_snaps, snap)) {
2587 uint64_t val, dlused, dlcomp, dluncomp;
2588 dsl_dataset_t *ds = snap->ds;
2590 /* Check that the snapshot name does not conflict */
2591 VERIFY(0 == dsl_dataset_get_snapname(ds));
2592 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val);
2600 /* The very first snapshot does not have a deadlist */
2601 if (ds->ds_phys->ds_prev_snap_obj == 0)
2604 dsl_deadlist_space(&ds->ds_deadlist,
2605 &dlused, &dlcomp, &dluncomp);
2608 pa->uncomp += dluncomp;
2612 * If we are a clone of a clone then we never reached ORIGIN,
2613 * so we need to subtract out the clone origin's used space.
2615 if (pa->origin_origin) {
2616 pa->used -= pa->origin_origin->ds_phys->ds_used_bytes;
2617 pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes;
2618 pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes;
2621 /* Check that there is enough space here */
2622 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir,
2628 * Compute the amounts of space that will be used by snapshots
2629 * after the promotion (for both origin and clone). For each,
2630 * it is the amount of space that will be on all of their
2631 * deadlists (that was not born before their new origin).
2633 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2637 * Note, typically this will not be a clone of a clone,
2638 * so dd_origin_txg will be < TXG_INITIAL, so
2639 * these snaplist_space() -> dsl_deadlist_space_range()
2640 * calls will be fast because they do not have to
2641 * iterate over all bps.
2643 snap = list_head(&pa->origin_snaps);
2644 err = snaplist_space(&pa->shared_snaps,
2645 snap->ds->ds_dir->dd_origin_txg, &pa->cloneusedsnap);
2649 err = snaplist_space(&pa->clone_snaps,
2650 snap->ds->ds_dir->dd_origin_txg, &space);
2653 pa->cloneusedsnap += space;
2655 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2656 err = snaplist_space(&pa->origin_snaps,
2657 origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap);
2664 pa->err_ds = snap->ds->ds_snapname;
2669 dsl_dataset_promote_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2671 dsl_dataset_t *hds = arg1;
2672 struct promotearg *pa = arg2;
2673 struct promotenode *snap = list_head(&pa->shared_snaps);
2674 dsl_dataset_t *origin_ds = snap->ds;
2675 dsl_dataset_t *origin_head;
2676 dsl_dir_t *dd = hds->ds_dir;
2677 dsl_pool_t *dp = hds->ds_dir->dd_pool;
2678 dsl_dir_t *odd = NULL;
2679 uint64_t oldnext_obj;
2682 ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE));
2684 snap = list_head(&pa->origin_snaps);
2685 origin_head = snap->ds;
2688 * We need to explicitly open odd, since origin_ds's dd will be
2691 VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object,
2694 /* change origin's next snap */
2695 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx);
2696 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj;
2697 snap = list_tail(&pa->clone_snaps);
2698 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2699 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object;
2701 /* change the origin's next clone */
2702 if (origin_ds->ds_phys->ds_next_clones_obj) {
2703 remove_from_next_clones(origin_ds, snap->ds->ds_object, tx);
2704 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2705 origin_ds->ds_phys->ds_next_clones_obj,
2710 dmu_buf_will_dirty(dd->dd_dbuf, tx);
2711 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object);
2712 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj;
2713 dd->dd_origin_txg = origin_head->ds_dir->dd_origin_txg;
2714 dmu_buf_will_dirty(odd->dd_dbuf, tx);
2715 odd->dd_phys->dd_origin_obj = origin_ds->ds_object;
2716 origin_head->ds_dir->dd_origin_txg =
2717 origin_ds->ds_phys->ds_creation_txg;
2719 /* change dd_clone entries */
2720 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2721 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
2722 odd->dd_phys->dd_clones, hds->ds_object, tx));
2723 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2724 pa->origin_origin->ds_dir->dd_phys->dd_clones,
2725 hds->ds_object, tx));
2727 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
2728 pa->origin_origin->ds_dir->dd_phys->dd_clones,
2729 origin_head->ds_object, tx));
2730 if (dd->dd_phys->dd_clones == 0) {
2731 dd->dd_phys->dd_clones = zap_create(dp->dp_meta_objset,
2732 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
2734 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2735 dd->dd_phys->dd_clones, origin_head->ds_object, tx));
2739 /* move snapshots to this dir */
2740 for (snap = list_head(&pa->shared_snaps); snap;
2741 snap = list_next(&pa->shared_snaps, snap)) {
2742 dsl_dataset_t *ds = snap->ds;
2744 /* unregister props as dsl_dir is changing */
2745 if (ds->ds_objset) {
2746 dmu_objset_evict(ds->ds_objset);
2747 ds->ds_objset = NULL;
2749 /* move snap name entry */
2750 VERIFY(0 == dsl_dataset_get_snapname(ds));
2751 VERIFY(0 == dsl_dataset_snap_remove(origin_head,
2752 ds->ds_snapname, tx));
2753 VERIFY(0 == zap_add(dp->dp_meta_objset,
2754 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname,
2755 8, 1, &ds->ds_object, tx));
2757 /* change containing dsl_dir */
2758 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2759 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object);
2760 ds->ds_phys->ds_dir_obj = dd->dd_object;
2761 ASSERT3P(ds->ds_dir, ==, odd);
2762 dsl_dir_close(ds->ds_dir, ds);
2763 VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object,
2764 NULL, ds, &ds->ds_dir));
2766 /* move any clone references */
2767 if (ds->ds_phys->ds_next_clones_obj &&
2768 spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2772 for (zap_cursor_init(&zc, dp->dp_meta_objset,
2773 ds->ds_phys->ds_next_clones_obj);
2774 zap_cursor_retrieve(&zc, &za) == 0;
2775 zap_cursor_advance(&zc)) {
2776 dsl_dataset_t *cnds;
2779 if (za.za_first_integer == oldnext_obj) {
2781 * We've already moved the
2782 * origin's reference.
2787 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
2788 za.za_first_integer, FTAG, &cnds));
2789 o = cnds->ds_dir->dd_phys->dd_head_dataset_obj;
2791 VERIFY3U(zap_remove_int(dp->dp_meta_objset,
2792 odd->dd_phys->dd_clones, o, tx), ==, 0);
2793 VERIFY3U(zap_add_int(dp->dp_meta_objset,
2794 dd->dd_phys->dd_clones, o, tx), ==, 0);
2795 dsl_dataset_rele(cnds, FTAG);
2797 zap_cursor_fini(&zc);
2800 ASSERT3U(dsl_prop_numcb(ds), ==, 0);
2804 * Change space accounting.
2805 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either
2806 * both be valid, or both be 0 (resulting in delta == 0). This
2807 * is true for each of {clone,origin} independently.
2810 delta = pa->cloneusedsnap -
2811 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2812 ASSERT3S(delta, >=, 0);
2813 ASSERT3U(pa->used, >=, delta);
2814 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx);
2815 dsl_dir_diduse_space(dd, DD_USED_HEAD,
2816 pa->used - delta, pa->comp, pa->uncomp, tx);
2818 delta = pa->originusedsnap -
2819 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2820 ASSERT3S(delta, <=, 0);
2821 ASSERT3U(pa->used, >=, -delta);
2822 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx);
2823 dsl_dir_diduse_space(odd, DD_USED_HEAD,
2824 -pa->used - delta, -pa->comp, -pa->uncomp, tx);
2826 origin_ds->ds_phys->ds_unique_bytes = pa->unique;
2828 /* log history record */
2829 spa_history_log_internal(LOG_DS_PROMOTE, dd->dd_pool->dp_spa, tx,
2830 "dataset = %llu", hds->ds_object);
2832 dsl_dir_close(odd, FTAG);
2835 static char *snaplist_tag = "snaplist";
2837 * Make a list of dsl_dataset_t's for the snapshots between first_obj
2838 * (exclusive) and last_obj (inclusive). The list will be in reverse
2839 * order (last_obj will be the list_head()). If first_obj == 0, do all
2840 * snapshots back to this dataset's origin.
2843 snaplist_make(dsl_pool_t *dp, boolean_t own,
2844 uint64_t first_obj, uint64_t last_obj, list_t *l)
2846 uint64_t obj = last_obj;
2848 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock));
2850 list_create(l, sizeof (struct promotenode),
2851 offsetof(struct promotenode, link));
2853 while (obj != first_obj) {
2855 struct promotenode *snap;
2859 err = dsl_dataset_own_obj(dp, obj,
2860 0, snaplist_tag, &ds);
2862 dsl_dataset_make_exclusive(ds, snaplist_tag);
2864 err = dsl_dataset_hold_obj(dp, obj, snaplist_tag, &ds);
2866 if (err == ENOENT) {
2867 /* lost race with snapshot destroy */
2868 struct promotenode *last = list_tail(l);
2869 ASSERT(obj != last->ds->ds_phys->ds_prev_snap_obj);
2870 obj = last->ds->ds_phys->ds_prev_snap_obj;
2877 first_obj = ds->ds_dir->dd_phys->dd_origin_obj;
2879 snap = kmem_alloc(sizeof (struct promotenode), KM_SLEEP);
2881 list_insert_tail(l, snap);
2882 obj = ds->ds_phys->ds_prev_snap_obj;
2889 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep)
2891 struct promotenode *snap;
2894 for (snap = list_head(l); snap; snap = list_next(l, snap)) {
2895 uint64_t used, comp, uncomp;
2896 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2897 mintxg, UINT64_MAX, &used, &comp, &uncomp);
2904 snaplist_destroy(list_t *l, boolean_t own)
2906 struct promotenode *snap;
2908 if (!l || !list_link_active(&l->list_head))
2911 while ((snap = list_tail(l)) != NULL) {
2912 list_remove(l, snap);
2914 dsl_dataset_disown(snap->ds, snaplist_tag);
2916 dsl_dataset_rele(snap->ds, snaplist_tag);
2917 kmem_free(snap, sizeof (struct promotenode));
2923 * Promote a clone. Nomenclature note:
2924 * "clone" or "cds": the original clone which is being promoted
2925 * "origin" or "ods": the snapshot which is originally clone's origin
2926 * "origin head" or "ohds": the dataset which is the head
2927 * (filesystem/volume) for the origin
2928 * "origin origin": the origin of the origin's filesystem (typically
2929 * NULL, indicating that the clone is not a clone of a clone).
2932 dsl_dataset_promote(const char *name, char *conflsnap)
2937 dmu_object_info_t doi;
2938 struct promotearg pa = { 0 };
2939 struct promotenode *snap;
2942 err = dsl_dataset_hold(name, FTAG, &ds);
2948 err = dmu_object_info(dp->dp_meta_objset,
2949 ds->ds_phys->ds_snapnames_zapobj, &doi);
2951 dsl_dataset_rele(ds, FTAG);
2955 if (dsl_dataset_is_snapshot(ds) || dd->dd_phys->dd_origin_obj == 0) {
2956 dsl_dataset_rele(ds, FTAG);
2961 * We are going to inherit all the snapshots taken before our
2962 * origin (i.e., our new origin will be our parent's origin).
2963 * Take ownership of them so that we can rename them into our
2966 rw_enter(&dp->dp_config_rwlock, RW_READER);
2968 err = snaplist_make(dp, B_TRUE, 0, dd->dd_phys->dd_origin_obj,
2973 err = snaplist_make(dp, B_FALSE, 0, ds->ds_object, &pa.clone_snaps);
2977 snap = list_head(&pa.shared_snaps);
2978 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj);
2979 err = snaplist_make(dp, B_FALSE, dd->dd_phys->dd_origin_obj,
2980 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj, &pa.origin_snaps);
2984 if (snap->ds->ds_dir->dd_phys->dd_origin_obj != 0) {
2985 err = dsl_dataset_hold_obj(dp,
2986 snap->ds->ds_dir->dd_phys->dd_origin_obj,
2987 FTAG, &pa.origin_origin);
2993 rw_exit(&dp->dp_config_rwlock);
2996 * Add in 128x the snapnames zapobj size, since we will be moving
2997 * a bunch of snapnames to the promoted ds, and dirtying their
3001 err = dsl_sync_task_do(dp, dsl_dataset_promote_check,
3002 dsl_dataset_promote_sync, ds, &pa,
3003 2 + 2 * doi.doi_physical_blocks_512);
3004 if (err && pa.err_ds && conflsnap)
3005 (void) strncpy(conflsnap, pa.err_ds, MAXNAMELEN);
3008 snaplist_destroy(&pa.shared_snaps, B_TRUE);
3009 snaplist_destroy(&pa.clone_snaps, B_FALSE);
3010 snaplist_destroy(&pa.origin_snaps, B_FALSE);
3011 if (pa.origin_origin)
3012 dsl_dataset_rele(pa.origin_origin, FTAG);
3013 dsl_dataset_rele(ds, FTAG);
3017 struct cloneswaparg {
3018 dsl_dataset_t *cds; /* clone dataset */
3019 dsl_dataset_t *ohds; /* origin's head dataset */
3021 int64_t unused_refres_delta; /* change in unconsumed refreservation */
3026 dsl_dataset_clone_swap_check(void *arg1, void *arg2, dmu_tx_t *tx)
3028 struct cloneswaparg *csa = arg1;
3030 /* they should both be heads */
3031 if (dsl_dataset_is_snapshot(csa->cds) ||
3032 dsl_dataset_is_snapshot(csa->ohds))
3035 /* the branch point should be just before them */
3036 if (csa->cds->ds_prev != csa->ohds->ds_prev)
3039 /* cds should be the clone (unless they are unrelated) */
3040 if (csa->cds->ds_prev != NULL &&
3041 csa->cds->ds_prev != csa->cds->ds_dir->dd_pool->dp_origin_snap &&
3042 csa->ohds->ds_object !=
3043 csa->cds->ds_prev->ds_phys->ds_next_snap_obj)
3046 /* the clone should be a child of the origin */
3047 if (csa->cds->ds_dir->dd_parent != csa->ohds->ds_dir)
3050 /* ohds shouldn't be modified unless 'force' */
3051 if (!csa->force && dsl_dataset_modified_since_lastsnap(csa->ohds))
3054 /* adjust amount of any unconsumed refreservation */
3055 csa->unused_refres_delta =
3056 (int64_t)MIN(csa->ohds->ds_reserved,
3057 csa->ohds->ds_phys->ds_unique_bytes) -
3058 (int64_t)MIN(csa->ohds->ds_reserved,
3059 csa->cds->ds_phys->ds_unique_bytes);
3061 if (csa->unused_refres_delta > 0 &&
3062 csa->unused_refres_delta >
3063 dsl_dir_space_available(csa->ohds->ds_dir, NULL, 0, TRUE))
3066 if (csa->ohds->ds_quota != 0 &&
3067 csa->cds->ds_phys->ds_unique_bytes > csa->ohds->ds_quota)
3075 dsl_dataset_clone_swap_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3077 struct cloneswaparg *csa = arg1;
3078 dsl_pool_t *dp = csa->cds->ds_dir->dd_pool;
3080 ASSERT(csa->cds->ds_reserved == 0);
3081 ASSERT(csa->ohds->ds_quota == 0 ||
3082 csa->cds->ds_phys->ds_unique_bytes <= csa->ohds->ds_quota);
3084 dmu_buf_will_dirty(csa->cds->ds_dbuf, tx);
3085 dmu_buf_will_dirty(csa->ohds->ds_dbuf, tx);
3087 if (csa->cds->ds_objset != NULL) {
3088 dmu_objset_evict(csa->cds->ds_objset);
3089 csa->cds->ds_objset = NULL;
3092 if (csa->ohds->ds_objset != NULL) {
3093 dmu_objset_evict(csa->ohds->ds_objset);
3094 csa->ohds->ds_objset = NULL;
3098 * Reset origin's unique bytes, if it exists.
3100 if (csa->cds->ds_prev) {
3101 dsl_dataset_t *origin = csa->cds->ds_prev;
3102 uint64_t comp, uncomp;
3104 dmu_buf_will_dirty(origin->ds_dbuf, tx);
3105 dsl_deadlist_space_range(&csa->cds->ds_deadlist,
3106 origin->ds_phys->ds_prev_snap_txg, UINT64_MAX,
3107 &origin->ds_phys->ds_unique_bytes, &comp, &uncomp);
3113 tmp = csa->ohds->ds_phys->ds_bp;
3114 csa->ohds->ds_phys->ds_bp = csa->cds->ds_phys->ds_bp;
3115 csa->cds->ds_phys->ds_bp = tmp;
3118 /* set dd_*_bytes */
3120 int64_t dused, dcomp, duncomp;
3121 uint64_t cdl_used, cdl_comp, cdl_uncomp;
3122 uint64_t odl_used, odl_comp, odl_uncomp;
3124 ASSERT3U(csa->cds->ds_dir->dd_phys->
3125 dd_used_breakdown[DD_USED_SNAP], ==, 0);
3127 dsl_deadlist_space(&csa->cds->ds_deadlist,
3128 &cdl_used, &cdl_comp, &cdl_uncomp);
3129 dsl_deadlist_space(&csa->ohds->ds_deadlist,
3130 &odl_used, &odl_comp, &odl_uncomp);
3132 dused = csa->cds->ds_phys->ds_used_bytes + cdl_used -
3133 (csa->ohds->ds_phys->ds_used_bytes + odl_used);
3134 dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp -
3135 (csa->ohds->ds_phys->ds_compressed_bytes + odl_comp);
3136 duncomp = csa->cds->ds_phys->ds_uncompressed_bytes +
3138 (csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp);
3140 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD,
3141 dused, dcomp, duncomp, tx);
3142 dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD,
3143 -dused, -dcomp, -duncomp, tx);
3146 * The difference in the space used by snapshots is the
3147 * difference in snapshot space due to the head's
3148 * deadlist (since that's the only thing that's
3149 * changing that affects the snapused).
3151 dsl_deadlist_space_range(&csa->cds->ds_deadlist,
3152 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX,
3153 &cdl_used, &cdl_comp, &cdl_uncomp);
3154 dsl_deadlist_space_range(&csa->ohds->ds_deadlist,
3155 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX,
3156 &odl_used, &odl_comp, &odl_uncomp);
3157 dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used,
3158 DD_USED_HEAD, DD_USED_SNAP, tx);
3161 /* swap ds_*_bytes */
3162 SWITCH64(csa->ohds->ds_phys->ds_used_bytes,
3163 csa->cds->ds_phys->ds_used_bytes);
3164 SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes,
3165 csa->cds->ds_phys->ds_compressed_bytes);
3166 SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes,
3167 csa->cds->ds_phys->ds_uncompressed_bytes);
3168 SWITCH64(csa->ohds->ds_phys->ds_unique_bytes,
3169 csa->cds->ds_phys->ds_unique_bytes);
3171 /* apply any parent delta for change in unconsumed refreservation */
3172 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV,
3173 csa->unused_refres_delta, 0, 0, tx);
3178 dsl_deadlist_close(&csa->cds->ds_deadlist);
3179 dsl_deadlist_close(&csa->ohds->ds_deadlist);
3180 SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj,
3181 csa->cds->ds_phys->ds_deadlist_obj);
3182 dsl_deadlist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset,
3183 csa->cds->ds_phys->ds_deadlist_obj);
3184 dsl_deadlist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset,
3185 csa->ohds->ds_phys->ds_deadlist_obj);
3187 dsl_scan_ds_clone_swapped(csa->ohds, csa->cds, tx);
3191 * Swap 'clone' with its origin head datasets. Used at the end of "zfs
3192 * recv" into an existing fs to swizzle the file system to the new
3193 * version, and by "zfs rollback". Can also be used to swap two
3194 * independent head datasets if neither has any snapshots.
3197 dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head,
3200 struct cloneswaparg csa;
3203 ASSERT(clone->ds_owner);
3204 ASSERT(origin_head->ds_owner);
3207 * Need exclusive access for the swap. If we're swapping these
3208 * datasets back after an error, we already hold the locks.
3210 if (!RW_WRITE_HELD(&clone->ds_rwlock))
3211 rw_enter(&clone->ds_rwlock, RW_WRITER);
3212 if (!RW_WRITE_HELD(&origin_head->ds_rwlock) &&
3213 !rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) {
3214 rw_exit(&clone->ds_rwlock);
3215 rw_enter(&origin_head->ds_rwlock, RW_WRITER);
3216 if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) {
3217 rw_exit(&origin_head->ds_rwlock);
3222 csa.ohds = origin_head;
3224 error = dsl_sync_task_do(clone->ds_dir->dd_pool,
3225 dsl_dataset_clone_swap_check,
3226 dsl_dataset_clone_swap_sync, &csa, NULL, 9);
3231 * Given a pool name and a dataset object number in that pool,
3232 * return the name of that dataset.
3235 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf)
3242 if ((error = spa_open(pname, &spa, FTAG)) != 0)
3244 dp = spa_get_dsl(spa);
3245 rw_enter(&dp->dp_config_rwlock, RW_READER);
3246 if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) {
3247 dsl_dataset_name(ds, buf);
3248 dsl_dataset_rele(ds, FTAG);
3250 rw_exit(&dp->dp_config_rwlock);
3251 spa_close(spa, FTAG);
3257 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota,
3258 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv)
3262 ASSERT3S(asize, >, 0);
3265 * *ref_rsrv is the portion of asize that will come from any
3266 * unconsumed refreservation space.
3270 mutex_enter(&ds->ds_lock);
3272 * Make a space adjustment for reserved bytes.
3274 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) {
3276 ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
3277 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
3279 asize - MIN(asize, parent_delta(ds, asize + inflight));
3282 if (!check_quota || ds->ds_quota == 0) {
3283 mutex_exit(&ds->ds_lock);
3287 * If they are requesting more space, and our current estimate
3288 * is over quota, they get to try again unless the actual
3289 * on-disk is over quota and there are no pending changes (which
3290 * may free up space for us).
3292 if (ds->ds_phys->ds_used_bytes + inflight >= ds->ds_quota) {
3293 if (inflight > 0 || ds->ds_phys->ds_used_bytes < ds->ds_quota)
3298 mutex_exit(&ds->ds_lock);
3305 dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx)
3307 dsl_dataset_t *ds = arg1;
3308 dsl_prop_setarg_t *psa = arg2;
3311 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA)
3314 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0)
3317 if (psa->psa_effective_value == 0)
3320 if (psa->psa_effective_value < ds->ds_phys->ds_used_bytes ||
3321 psa->psa_effective_value < ds->ds_reserved)
3327 extern void dsl_prop_set_sync(void *, void *, dmu_tx_t *);
3330 dsl_dataset_set_quota_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3332 dsl_dataset_t *ds = arg1;
3333 dsl_prop_setarg_t *psa = arg2;
3334 uint64_t effective_value = psa->psa_effective_value;
3336 dsl_prop_set_sync(ds, psa, tx);
3337 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa);
3339 if (ds->ds_quota != effective_value) {
3340 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3341 ds->ds_quota = effective_value;
3343 spa_history_log_internal(LOG_DS_REFQUOTA,
3344 ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu ",
3345 (longlong_t)ds->ds_quota, ds->ds_object);
3350 dsl_dataset_set_quota(const char *dsname, zprop_source_t source, uint64_t quota)
3353 dsl_prop_setarg_t psa;
3356 dsl_prop_setarg_init_uint64(&psa, "refquota", source, "a);
3358 err = dsl_dataset_hold(dsname, FTAG, &ds);
3363 * If someone removes a file, then tries to set the quota, we
3364 * want to make sure the file freeing takes effect.
3366 txg_wait_open(ds->ds_dir->dd_pool, 0);
3368 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
3369 dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync,
3372 dsl_dataset_rele(ds, FTAG);
3377 dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx)
3379 dsl_dataset_t *ds = arg1;
3380 dsl_prop_setarg_t *psa = arg2;
3381 uint64_t effective_value;
3385 if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
3386 SPA_VERSION_REFRESERVATION)
3389 if (dsl_dataset_is_snapshot(ds))
3392 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0)
3395 effective_value = psa->psa_effective_value;
3398 * If we are doing the preliminary check in open context, the
3399 * space estimates may be inaccurate.
3401 if (!dmu_tx_is_syncing(tx))
3404 mutex_enter(&ds->ds_lock);
3405 if (!DS_UNIQUE_IS_ACCURATE(ds))
3406 dsl_dataset_recalc_head_uniq(ds);
3407 unique = ds->ds_phys->ds_unique_bytes;
3408 mutex_exit(&ds->ds_lock);
3410 if (MAX(unique, effective_value) > MAX(unique, ds->ds_reserved)) {
3411 uint64_t delta = MAX(unique, effective_value) -
3412 MAX(unique, ds->ds_reserved);
3414 if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
3416 if (ds->ds_quota > 0 &&
3417 effective_value > ds->ds_quota)
3425 dsl_dataset_set_reservation_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3427 dsl_dataset_t *ds = arg1;
3428 dsl_prop_setarg_t *psa = arg2;
3429 uint64_t effective_value = psa->psa_effective_value;
3433 dsl_prop_set_sync(ds, psa, tx);
3434 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa);
3436 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3438 mutex_enter(&ds->ds_dir->dd_lock);
3439 mutex_enter(&ds->ds_lock);
3440 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
3441 unique = ds->ds_phys->ds_unique_bytes;
3442 delta = MAX(0, (int64_t)(effective_value - unique)) -
3443 MAX(0, (int64_t)(ds->ds_reserved - unique));
3444 ds->ds_reserved = effective_value;
3445 mutex_exit(&ds->ds_lock);
3447 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx);
3448 mutex_exit(&ds->ds_dir->dd_lock);
3450 spa_history_log_internal(LOG_DS_REFRESERV,
3451 ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu",
3452 (longlong_t)effective_value, ds->ds_object);
3456 dsl_dataset_set_reservation(const char *dsname, zprop_source_t source,
3457 uint64_t reservation)
3460 dsl_prop_setarg_t psa;
3463 dsl_prop_setarg_init_uint64(&psa, "refreservation", source,
3466 err = dsl_dataset_hold(dsname, FTAG, &ds);
3470 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
3471 dsl_dataset_set_reservation_check,
3472 dsl_dataset_set_reservation_sync, ds, &psa, 0);
3474 dsl_dataset_rele(ds, FTAG);
3478 typedef struct zfs_hold_cleanup_arg {
3481 char htag[MAXNAMELEN];
3482 } zfs_hold_cleanup_arg_t;
3485 dsl_dataset_user_release_onexit(void *arg)
3487 zfs_hold_cleanup_arg_t *ca = arg;
3489 (void) dsl_dataset_user_release_tmp(ca->dp, ca->dsobj, ca->htag,
3491 kmem_free(ca, sizeof (zfs_hold_cleanup_arg_t));
3495 dsl_register_onexit_hold_cleanup(dsl_dataset_t *ds, const char *htag,
3498 zfs_hold_cleanup_arg_t *ca;
3500 ca = kmem_alloc(sizeof (zfs_hold_cleanup_arg_t), KM_SLEEP);
3501 ca->dp = ds->ds_dir->dd_pool;
3502 ca->dsobj = ds->ds_object;
3503 (void) strlcpy(ca->htag, htag, sizeof (ca->htag));
3504 VERIFY3U(0, ==, zfs_onexit_add_cb(minor,
3505 dsl_dataset_user_release_onexit, ca, NULL));
3509 * If you add new checks here, you may need to add
3510 * additional checks to the "temporary" case in
3511 * snapshot_check() in dmu_objset.c.
3514 dsl_dataset_user_hold_check(void *arg1, void *arg2, dmu_tx_t *tx)
3516 dsl_dataset_t *ds = arg1;
3517 struct dsl_ds_holdarg *ha = arg2;
3518 char *htag = ha->htag;
3519 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3522 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS)
3525 if (!dsl_dataset_is_snapshot(ds))
3528 /* tags must be unique */
3529 mutex_enter(&ds->ds_lock);
3530 if (ds->ds_phys->ds_userrefs_obj) {
3531 error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj, htag,
3535 else if (error == ENOENT)
3538 mutex_exit(&ds->ds_lock);
3540 if (error == 0 && ha->temphold &&
3541 strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN)
3548 dsl_dataset_user_hold_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3550 dsl_dataset_t *ds = arg1;
3551 struct dsl_ds_holdarg *ha = arg2;
3552 char *htag = ha->htag;
3553 dsl_pool_t *dp = ds->ds_dir->dd_pool;
3554 objset_t *mos = dp->dp_meta_objset;
3555 uint64_t now = gethrestime_sec();
3558 mutex_enter(&ds->ds_lock);
3559 if (ds->ds_phys->ds_userrefs_obj == 0) {
3561 * This is the first user hold for this dataset. Create
3562 * the userrefs zap object.
3564 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3565 zapobj = ds->ds_phys->ds_userrefs_obj =
3566 zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx);
3568 zapobj = ds->ds_phys->ds_userrefs_obj;
3571 mutex_exit(&ds->ds_lock);
3573 VERIFY(0 == zap_add(mos, zapobj, htag, 8, 1, &now, tx));
3576 VERIFY(0 == dsl_pool_user_hold(dp, ds->ds_object,
3580 spa_history_log_internal(LOG_DS_USER_HOLD,
3581 dp->dp_spa, tx, "<%s> temp = %d dataset = %llu", htag,
3582 (int)ha->temphold, ds->ds_object);
3586 dsl_dataset_user_hold_one(const char *dsname, void *arg)
3588 struct dsl_ds_holdarg *ha = arg;
3593 /* alloc a buffer to hold dsname@snapname plus terminating NULL */
3594 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3595 error = dsl_dataset_hold(name, ha->dstg, &ds);
3598 ha->gotone = B_TRUE;
3599 dsl_sync_task_create(ha->dstg, dsl_dataset_user_hold_check,
3600 dsl_dataset_user_hold_sync, ds, ha, 0);
3601 } else if (error == ENOENT && ha->recursive) {
3604 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3610 dsl_dataset_user_hold_for_send(dsl_dataset_t *ds, char *htag,
3613 struct dsl_ds_holdarg *ha;
3616 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3618 ha->temphold = temphold;
3619 error = dsl_sync_task_do(ds->ds_dir->dd_pool,
3620 dsl_dataset_user_hold_check, dsl_dataset_user_hold_sync,
3622 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3628 dsl_dataset_user_hold(char *dsname, char *snapname, char *htag,
3629 boolean_t recursive, boolean_t temphold, int cleanup_fd)
3631 struct dsl_ds_holdarg *ha;
3632 dsl_sync_task_t *dst;
3637 if (cleanup_fd != -1) {
3638 /* Currently we only support cleanup-on-exit of tempholds. */
3641 error = zfs_onexit_fd_hold(cleanup_fd, &minor);
3646 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3648 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3650 error = spa_open(dsname, &spa, FTAG);
3652 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3653 if (cleanup_fd != -1)
3654 zfs_onexit_fd_rele(cleanup_fd);
3658 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
3660 ha->snapname = snapname;
3661 ha->recursive = recursive;
3662 ha->temphold = temphold;
3665 error = dmu_objset_find(dsname, dsl_dataset_user_hold_one,
3666 ha, DS_FIND_CHILDREN);
3668 error = dsl_dataset_user_hold_one(dsname, ha);
3671 error = dsl_sync_task_group_wait(ha->dstg);
3673 for (dst = list_head(&ha->dstg->dstg_tasks); dst;
3674 dst = list_next(&ha->dstg->dstg_tasks, dst)) {
3675 dsl_dataset_t *ds = dst->dst_arg1;
3678 dsl_dataset_name(ds, ha->failed);
3679 *strchr(ha->failed, '@') = '\0';
3680 } else if (error == 0 && minor != 0 && temphold) {
3682 * If this hold is to be released upon process exit,
3683 * register that action now.
3685 dsl_register_onexit_hold_cleanup(ds, htag, minor);
3687 dsl_dataset_rele(ds, ha->dstg);
3690 if (error == 0 && recursive && !ha->gotone)
3694 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed));
3696 dsl_sync_task_group_destroy(ha->dstg);
3698 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3699 spa_close(spa, FTAG);
3700 if (cleanup_fd != -1)
3701 zfs_onexit_fd_rele(cleanup_fd);
3705 struct dsl_ds_releasearg {
3708 boolean_t own; /* do we own or just hold ds? */
3712 dsl_dataset_release_might_destroy(dsl_dataset_t *ds, const char *htag,
3713 boolean_t *might_destroy)
3715 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3720 *might_destroy = B_FALSE;
3722 mutex_enter(&ds->ds_lock);
3723 zapobj = ds->ds_phys->ds_userrefs_obj;
3725 /* The tag can't possibly exist */
3726 mutex_exit(&ds->ds_lock);
3730 /* Make sure the tag exists */
3731 error = zap_lookup(mos, zapobj, htag, 8, 1, &tmp);
3733 mutex_exit(&ds->ds_lock);
3734 if (error == ENOENT)
3739 if (ds->ds_userrefs == 1 && ds->ds_phys->ds_num_children == 1 &&
3740 DS_IS_DEFER_DESTROY(ds))
3741 *might_destroy = B_TRUE;
3743 mutex_exit(&ds->ds_lock);
3748 dsl_dataset_user_release_check(void *arg1, void *tag, dmu_tx_t *tx)
3750 struct dsl_ds_releasearg *ra = arg1;
3751 dsl_dataset_t *ds = ra->ds;
3752 boolean_t might_destroy;
3755 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS)
3758 error = dsl_dataset_release_might_destroy(ds, ra->htag, &might_destroy);
3762 if (might_destroy) {
3763 struct dsl_ds_destroyarg dsda = {0};
3765 if (dmu_tx_is_syncing(tx)) {
3767 * If we're not prepared to remove the snapshot,
3768 * we can't allow the release to happen right now.
3774 dsda.releasing = B_TRUE;
3775 return (dsl_dataset_destroy_check(&dsda, tag, tx));
3782 dsl_dataset_user_release_sync(void *arg1, void *tag, dmu_tx_t *tx)
3784 struct dsl_ds_releasearg *ra = arg1;
3785 dsl_dataset_t *ds = ra->ds;
3786 dsl_pool_t *dp = ds->ds_dir->dd_pool;
3787 objset_t *mos = dp->dp_meta_objset;
3789 uint64_t dsobj = ds->ds_object;
3793 mutex_enter(&ds->ds_lock);
3795 refs = ds->ds_userrefs;
3796 mutex_exit(&ds->ds_lock);
3797 error = dsl_pool_user_release(dp, ds->ds_object, ra->htag, tx);
3798 VERIFY(error == 0 || error == ENOENT);
3799 zapobj = ds->ds_phys->ds_userrefs_obj;
3800 VERIFY(0 == zap_remove(mos, zapobj, ra->htag, tx));
3801 if (ds->ds_userrefs == 0 && ds->ds_phys->ds_num_children == 1 &&
3802 DS_IS_DEFER_DESTROY(ds)) {
3803 struct dsl_ds_destroyarg dsda = {0};
3807 dsda.releasing = B_TRUE;
3808 /* We already did the destroy_check */
3809 dsl_dataset_destroy_sync(&dsda, tag, tx);
3812 spa_history_log_internal(LOG_DS_USER_RELEASE,
3813 dp->dp_spa, tx, "<%s> %lld dataset = %llu",
3814 ra->htag, (longlong_t)refs, dsobj);
3818 dsl_dataset_user_release_one(const char *dsname, void *arg)
3820 struct dsl_ds_holdarg *ha = arg;
3821 struct dsl_ds_releasearg *ra;
3824 void *dtag = ha->dstg;
3826 boolean_t own = B_FALSE;
3827 boolean_t might_destroy;
3829 /* alloc a buffer to hold dsname@snapname, plus the terminating NULL */
3830 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3831 error = dsl_dataset_hold(name, dtag, &ds);
3833 if (error == ENOENT && ha->recursive)
3835 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3839 ha->gotone = B_TRUE;
3841 ASSERT(dsl_dataset_is_snapshot(ds));
3843 error = dsl_dataset_release_might_destroy(ds, ha->htag, &might_destroy);
3845 dsl_dataset_rele(ds, dtag);
3849 if (might_destroy) {
3851 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3852 error = zfs_unmount_snap(name, NULL);
3855 dsl_dataset_rele(ds, dtag);
3859 if (!dsl_dataset_tryown(ds, B_TRUE, dtag)) {
3860 dsl_dataset_rele(ds, dtag);
3864 dsl_dataset_make_exclusive(ds, dtag);
3868 ra = kmem_alloc(sizeof (struct dsl_ds_releasearg), KM_SLEEP);
3870 ra->htag = ha->htag;
3872 dsl_sync_task_create(ha->dstg, dsl_dataset_user_release_check,
3873 dsl_dataset_user_release_sync, ra, dtag, 0);
3879 dsl_dataset_user_release(char *dsname, char *snapname, char *htag,
3880 boolean_t recursive)
3882 struct dsl_ds_holdarg *ha;
3883 dsl_sync_task_t *dst;
3888 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3890 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3892 error = spa_open(dsname, &spa, FTAG);
3894 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3898 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
3900 ha->snapname = snapname;
3901 ha->recursive = recursive;
3903 error = dmu_objset_find(dsname, dsl_dataset_user_release_one,
3904 ha, DS_FIND_CHILDREN);
3906 error = dsl_dataset_user_release_one(dsname, ha);
3909 error = dsl_sync_task_group_wait(ha->dstg);
3911 for (dst = list_head(&ha->dstg->dstg_tasks); dst;
3912 dst = list_next(&ha->dstg->dstg_tasks, dst)) {
3913 struct dsl_ds_releasearg *ra = dst->dst_arg1;
3914 dsl_dataset_t *ds = ra->ds;
3917 dsl_dataset_name(ds, ha->failed);
3920 dsl_dataset_disown(ds, ha->dstg);
3922 dsl_dataset_rele(ds, ha->dstg);
3924 kmem_free(ra, sizeof (struct dsl_ds_releasearg));
3927 if (error == 0 && recursive && !ha->gotone)
3930 if (error && error != EBUSY)
3931 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed));
3933 dsl_sync_task_group_destroy(ha->dstg);
3934 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3935 spa_close(spa, FTAG);
3938 * We can get EBUSY if we were racing with deferred destroy and
3939 * dsl_dataset_user_release_check() hadn't done the necessary
3940 * open context setup. We can also get EBUSY if we're racing
3941 * with destroy and that thread is the ds_owner. Either way
3942 * the busy condition should be transient, and we should retry
3943 * the release operation.
3952 * Called at spa_load time (with retry == B_FALSE) to release a stale
3953 * temporary user hold. Also called by the onexit code (with retry == B_TRUE).
3956 dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, char *htag,
3966 rw_enter(&dp->dp_config_rwlock, RW_READER);
3967 error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds);
3968 rw_exit(&dp->dp_config_rwlock);
3971 namelen = dsl_dataset_namelen(ds)+1;
3972 name = kmem_alloc(namelen, KM_SLEEP);
3973 dsl_dataset_name(ds, name);
3974 dsl_dataset_rele(ds, FTAG);
3976 snap = strchr(name, '@');
3979 error = dsl_dataset_user_release(name, snap, htag, B_FALSE);
3980 kmem_free(name, namelen);
3983 * The object can't have been destroyed because we have a hold,
3984 * but it might have been renamed, resulting in ENOENT. Retry
3985 * if we've been requested to do so.
3987 * It would be nice if we could use the dsobj all the way
3988 * through and avoid ENOENT entirely. But we might need to
3989 * unmount the snapshot, and there's currently no way to lookup
3990 * a vfsp using a ZFS object id.
3992 } while ((error == ENOENT) && retry);
3998 dsl_dataset_get_holds(const char *dsname, nvlist_t **nvp)
4003 err = dsl_dataset_hold(dsname, FTAG, &ds);
4007 VERIFY(0 == nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP));
4008 if (ds->ds_phys->ds_userrefs_obj != 0) {
4009 zap_attribute_t *za;
4012 za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP);
4013 for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset,
4014 ds->ds_phys->ds_userrefs_obj);
4015 zap_cursor_retrieve(&zc, za) == 0;
4016 zap_cursor_advance(&zc)) {
4017 VERIFY(0 == nvlist_add_uint64(*nvp, za->za_name,
4018 za->za_first_integer));
4020 zap_cursor_fini(&zc);
4021 kmem_free(za, sizeof (zap_attribute_t));
4023 dsl_dataset_rele(ds, FTAG);
4028 * Note, this fuction is used as the callback for dmu_objset_find(). We
4029 * always return 0 so that we will continue to find and process
4030 * inconsistent datasets, even if we encounter an error trying to
4031 * process one of them.
4035 dsl_destroy_inconsistent(const char *dsname, void *arg)
4039 if (dsl_dataset_own(dsname, B_TRUE, FTAG, &ds) == 0) {
4040 if (DS_IS_INCONSISTENT(ds))
4041 (void) dsl_dataset_destroy(ds, FTAG, B_FALSE);
4043 dsl_dataset_disown(ds, FTAG);