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) 2012 by Delphix. All rights reserved.
24 * Copyright (c) 2012, Joyent, Inc. All rights reserved.
25 * Copyright (c) 2011 Pawel Jakub Dawidek <pawel@dawidek.net>.
26 * All rights reserved.
27 * Portions Copyright (c) 2011 Martin Matuska <mm@FreeBSD.org>
30 #include <sys/dmu_objset.h>
31 #include <sys/dsl_dataset.h>
32 #include <sys/dsl_dir.h>
33 #include <sys/dsl_prop.h>
34 #include <sys/dsl_synctask.h>
35 #include <sys/dmu_traverse.h>
36 #include <sys/dmu_impl.h>
37 #include <sys/dmu_tx.h>
41 #include <sys/zfeature.h>
42 #include <sys/unique.h>
43 #include <sys/zfs_context.h>
44 #include <sys/zfs_ioctl.h>
46 #include <sys/zfs_znode.h>
47 #include <sys/zfs_onexit.h>
49 #include <sys/dsl_scan.h>
50 #include <sys/dsl_deadlist.h>
52 static char *dsl_reaper = "the grim reaper";
54 static dsl_checkfunc_t dsl_dataset_destroy_begin_check;
55 static dsl_syncfunc_t dsl_dataset_destroy_begin_sync;
56 static dsl_syncfunc_t dsl_dataset_set_reservation_sync;
58 #define SWITCH64(x, y) \
60 uint64_t __tmp = (x); \
65 #define DS_REF_MAX (1ULL << 62)
67 #define DSL_DEADLIST_BLOCKSIZE SPA_MAXBLOCKSIZE
69 #define DSL_DATASET_IS_DESTROYED(ds) ((ds)->ds_owner == dsl_reaper)
73 * Figure out how much of this delta should be propogated to the dsl_dir
74 * layer. If there's a refreservation, that space has already been
75 * partially accounted for in our ancestors.
78 parent_delta(dsl_dataset_t *ds, int64_t delta)
80 uint64_t old_bytes, new_bytes;
82 if (ds->ds_reserved == 0)
85 old_bytes = MAX(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
86 new_bytes = MAX(ds->ds_phys->ds_unique_bytes + delta, ds->ds_reserved);
88 ASSERT3U(ABS((int64_t)(new_bytes - old_bytes)), <=, ABS(delta));
89 return (new_bytes - old_bytes);
93 dsl_dataset_block_born(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx)
95 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
96 int compressed = BP_GET_PSIZE(bp);
97 int uncompressed = BP_GET_UCSIZE(bp);
100 dprintf_bp(bp, "ds=%p", ds);
102 ASSERT(dmu_tx_is_syncing(tx));
103 /* It could have been compressed away to nothing */
106 ASSERT(BP_GET_TYPE(bp) != DMU_OT_NONE);
107 ASSERT(DMU_OT_IS_VALID(BP_GET_TYPE(bp)));
109 dsl_pool_mos_diduse_space(tx->tx_pool,
110 used, compressed, uncompressed);
113 dmu_buf_will_dirty(ds->ds_dbuf, tx);
115 mutex_enter(&ds->ds_dir->dd_lock);
116 mutex_enter(&ds->ds_lock);
117 delta = parent_delta(ds, used);
118 ds->ds_phys->ds_referenced_bytes += used;
119 ds->ds_phys->ds_compressed_bytes += compressed;
120 ds->ds_phys->ds_uncompressed_bytes += uncompressed;
121 ds->ds_phys->ds_unique_bytes += used;
122 mutex_exit(&ds->ds_lock);
123 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta,
124 compressed, uncompressed, tx);
125 dsl_dir_transfer_space(ds->ds_dir, used - delta,
126 DD_USED_REFRSRV, DD_USED_HEAD, tx);
127 mutex_exit(&ds->ds_dir->dd_lock);
131 dsl_dataset_block_kill(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx,
137 ASSERT(dmu_tx_is_syncing(tx));
138 ASSERT(bp->blk_birth <= tx->tx_txg);
140 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
141 int compressed = BP_GET_PSIZE(bp);
142 int uncompressed = BP_GET_UCSIZE(bp);
146 dsl_free(tx->tx_pool, tx->tx_txg, bp);
147 dsl_pool_mos_diduse_space(tx->tx_pool,
148 -used, -compressed, -uncompressed);
151 ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool);
153 ASSERT(!dsl_dataset_is_snapshot(ds));
154 dmu_buf_will_dirty(ds->ds_dbuf, tx);
156 if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) {
159 dprintf_bp(bp, "freeing ds=%llu", ds->ds_object);
160 dsl_free(tx->tx_pool, tx->tx_txg, bp);
162 mutex_enter(&ds->ds_dir->dd_lock);
163 mutex_enter(&ds->ds_lock);
164 ASSERT(ds->ds_phys->ds_unique_bytes >= used ||
165 !DS_UNIQUE_IS_ACCURATE(ds));
166 delta = parent_delta(ds, -used);
167 ds->ds_phys->ds_unique_bytes -= used;
168 mutex_exit(&ds->ds_lock);
169 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
170 delta, -compressed, -uncompressed, tx);
171 dsl_dir_transfer_space(ds->ds_dir, -used - delta,
172 DD_USED_REFRSRV, DD_USED_HEAD, tx);
173 mutex_exit(&ds->ds_dir->dd_lock);
175 dprintf_bp(bp, "putting on dead list: %s", "");
178 * We are here as part of zio's write done callback,
179 * which means we're a zio interrupt thread. We can't
180 * call dsl_deadlist_insert() now because it may block
181 * waiting for I/O. Instead, put bp on the deferred
182 * queue and let dsl_pool_sync() finish the job.
184 bplist_append(&ds->ds_pending_deadlist, bp);
186 dsl_deadlist_insert(&ds->ds_deadlist, bp, tx);
188 ASSERT3U(ds->ds_prev->ds_object, ==,
189 ds->ds_phys->ds_prev_snap_obj);
190 ASSERT(ds->ds_prev->ds_phys->ds_num_children > 0);
191 /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */
192 if (ds->ds_prev->ds_phys->ds_next_snap_obj ==
193 ds->ds_object && bp->blk_birth >
194 ds->ds_prev->ds_phys->ds_prev_snap_txg) {
195 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
196 mutex_enter(&ds->ds_prev->ds_lock);
197 ds->ds_prev->ds_phys->ds_unique_bytes += used;
198 mutex_exit(&ds->ds_prev->ds_lock);
200 if (bp->blk_birth > ds->ds_dir->dd_origin_txg) {
201 dsl_dir_transfer_space(ds->ds_dir, used,
202 DD_USED_HEAD, DD_USED_SNAP, tx);
205 mutex_enter(&ds->ds_lock);
206 ASSERT3U(ds->ds_phys->ds_referenced_bytes, >=, used);
207 ds->ds_phys->ds_referenced_bytes -= used;
208 ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed);
209 ds->ds_phys->ds_compressed_bytes -= compressed;
210 ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed);
211 ds->ds_phys->ds_uncompressed_bytes -= uncompressed;
212 mutex_exit(&ds->ds_lock);
218 dsl_dataset_prev_snap_txg(dsl_dataset_t *ds)
220 uint64_t trysnap = 0;
225 * The snapshot creation could fail, but that would cause an
226 * incorrect FALSE return, which would only result in an
227 * overestimation of the amount of space that an operation would
228 * consume, which is OK.
230 * There's also a small window where we could miss a pending
231 * snapshot, because we could set the sync task in the quiescing
232 * phase. So this should only be used as a guess.
234 if (ds->ds_trysnap_txg >
235 spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa))
236 trysnap = ds->ds_trysnap_txg;
237 return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap));
241 dsl_dataset_block_freeable(dsl_dataset_t *ds, const blkptr_t *bp,
244 if (blk_birth <= dsl_dataset_prev_snap_txg(ds))
247 ddt_prefetch(dsl_dataset_get_spa(ds), bp);
254 dsl_dataset_evict(dmu_buf_t *db, void *dsv)
256 dsl_dataset_t *ds = dsv;
258 ASSERT(ds->ds_owner == NULL || DSL_DATASET_IS_DESTROYED(ds));
260 unique_remove(ds->ds_fsid_guid);
262 if (ds->ds_objset != NULL)
263 dmu_objset_evict(ds->ds_objset);
266 dsl_dataset_drop_ref(ds->ds_prev, ds);
270 bplist_destroy(&ds->ds_pending_deadlist);
272 dsl_deadlist_close(&ds->ds_deadlist);
274 ASSERT(ds->ds_deadlist.dl_dbuf == NULL);
275 ASSERT(!ds->ds_deadlist.dl_oldfmt);
278 dsl_dir_close(ds->ds_dir, ds);
280 ASSERT(!list_link_active(&ds->ds_synced_link));
282 if (mutex_owned(&ds->ds_lock))
283 mutex_exit(&ds->ds_lock);
284 mutex_destroy(&ds->ds_lock);
285 mutex_destroy(&ds->ds_recvlock);
286 if (mutex_owned(&ds->ds_opening_lock))
287 mutex_exit(&ds->ds_opening_lock);
288 mutex_destroy(&ds->ds_opening_lock);
289 rw_destroy(&ds->ds_rwlock);
290 cv_destroy(&ds->ds_exclusive_cv);
292 kmem_free(ds, sizeof (dsl_dataset_t));
296 dsl_dataset_get_snapname(dsl_dataset_t *ds)
298 dsl_dataset_phys_t *headphys;
301 dsl_pool_t *dp = ds->ds_dir->dd_pool;
302 objset_t *mos = dp->dp_meta_objset;
304 if (ds->ds_snapname[0])
306 if (ds->ds_phys->ds_next_snap_obj == 0)
309 err = dmu_bonus_hold(mos, ds->ds_dir->dd_phys->dd_head_dataset_obj,
313 headphys = headdbuf->db_data;
314 err = zap_value_search(dp->dp_meta_objset,
315 headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname);
316 dmu_buf_rele(headdbuf, FTAG);
321 dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name, uint64_t *value)
323 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
324 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
328 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
333 err = zap_lookup_norm(mos, snapobj, name, 8, 1,
334 value, mt, NULL, 0, NULL);
335 if (err == ENOTSUP && mt == MT_FIRST)
336 err = zap_lookup(mos, snapobj, name, 8, 1, value);
341 dsl_dataset_snap_remove(dsl_dataset_t *ds, char *name, dmu_tx_t *tx)
343 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
344 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
348 dsl_dir_snap_cmtime_update(ds->ds_dir);
350 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
355 err = zap_remove_norm(mos, snapobj, name, mt, tx);
356 if (err == ENOTSUP && mt == MT_FIRST)
357 err = zap_remove(mos, snapobj, name, tx);
362 dsl_dataset_get_ref(dsl_pool_t *dp, uint64_t dsobj, void *tag,
365 objset_t *mos = dp->dp_meta_objset;
369 dmu_object_info_t doi;
371 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) ||
372 dsl_pool_sync_context(dp));
374 err = dmu_bonus_hold(mos, dsobj, tag, &dbuf);
378 /* Make sure dsobj has the correct object type. */
379 dmu_object_info_from_db(dbuf, &doi);
380 if (doi.doi_type != DMU_OT_DSL_DATASET)
383 ds = dmu_buf_get_user(dbuf);
385 dsl_dataset_t *winner = NULL;
387 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP);
389 ds->ds_object = dsobj;
390 ds->ds_phys = dbuf->db_data;
392 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL);
393 mutex_init(&ds->ds_recvlock, NULL, MUTEX_DEFAULT, NULL);
394 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL);
395 mutex_init(&ds->ds_sendstream_lock, NULL, MUTEX_DEFAULT, NULL);
397 rw_init(&ds->ds_rwlock, 0, 0, 0);
398 cv_init(&ds->ds_exclusive_cv, NULL, CV_DEFAULT, NULL);
400 bplist_create(&ds->ds_pending_deadlist);
401 dsl_deadlist_open(&ds->ds_deadlist,
402 mos, ds->ds_phys->ds_deadlist_obj);
404 list_create(&ds->ds_sendstreams, sizeof (dmu_sendarg_t),
405 offsetof(dmu_sendarg_t, dsa_link));
408 err = dsl_dir_open_obj(dp,
409 ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir);
412 mutex_destroy(&ds->ds_lock);
413 mutex_destroy(&ds->ds_recvlock);
414 mutex_destroy(&ds->ds_opening_lock);
415 rw_destroy(&ds->ds_rwlock);
416 cv_destroy(&ds->ds_exclusive_cv);
417 bplist_destroy(&ds->ds_pending_deadlist);
418 dsl_deadlist_close(&ds->ds_deadlist);
419 kmem_free(ds, sizeof (dsl_dataset_t));
420 dmu_buf_rele(dbuf, tag);
424 if (!dsl_dataset_is_snapshot(ds)) {
425 ds->ds_snapname[0] = '\0';
426 if (ds->ds_phys->ds_prev_snap_obj) {
427 err = dsl_dataset_get_ref(dp,
428 ds->ds_phys->ds_prev_snap_obj,
432 if (zfs_flags & ZFS_DEBUG_SNAPNAMES)
433 err = dsl_dataset_get_snapname(ds);
434 if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) {
436 ds->ds_dir->dd_pool->dp_meta_objset,
437 ds->ds_phys->ds_userrefs_obj,
442 if (err == 0 && !dsl_dataset_is_snapshot(ds)) {
444 * In sync context, we're called with either no lock
445 * or with the write lock. If we're not syncing,
446 * we're always called with the read lock held.
448 boolean_t need_lock =
449 !RW_WRITE_HELD(&dp->dp_config_rwlock) &&
450 dsl_pool_sync_context(dp);
453 rw_enter(&dp->dp_config_rwlock, RW_READER);
455 err = dsl_prop_get_ds(ds,
456 "refreservation", sizeof (uint64_t), 1,
457 &ds->ds_reserved, NULL);
459 err = dsl_prop_get_ds(ds,
460 "refquota", sizeof (uint64_t), 1,
461 &ds->ds_quota, NULL);
465 rw_exit(&dp->dp_config_rwlock);
467 ds->ds_reserved = ds->ds_quota = 0;
470 if (err != 0 || (winner = dmu_buf_set_user_ie(dbuf, ds,
471 &ds->ds_phys, dsl_dataset_evict)) != NULL) {
472 bplist_destroy(&ds->ds_pending_deadlist);
473 dsl_deadlist_close(&ds->ds_deadlist);
475 dsl_dataset_drop_ref(ds->ds_prev, ds);
476 dsl_dir_close(ds->ds_dir, ds);
477 mutex_destroy(&ds->ds_lock);
478 mutex_destroy(&ds->ds_recvlock);
479 mutex_destroy(&ds->ds_opening_lock);
480 rw_destroy(&ds->ds_rwlock);
481 cv_destroy(&ds->ds_exclusive_cv);
482 kmem_free(ds, sizeof (dsl_dataset_t));
484 dmu_buf_rele(dbuf, tag);
490 unique_insert(ds->ds_phys->ds_fsid_guid);
493 ASSERT3P(ds->ds_dbuf, ==, dbuf);
494 ASSERT3P(ds->ds_phys, ==, dbuf->db_data);
495 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 ||
496 spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN ||
497 dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap);
498 mutex_enter(&ds->ds_lock);
499 if (!dsl_pool_sync_context(dp) && DSL_DATASET_IS_DESTROYED(ds)) {
500 mutex_exit(&ds->ds_lock);
501 dmu_buf_rele(ds->ds_dbuf, tag);
504 mutex_exit(&ds->ds_lock);
510 dsl_dataset_hold_ref(dsl_dataset_t *ds, void *tag)
512 dsl_pool_t *dp = ds->ds_dir->dd_pool;
515 * In syncing context we don't want the rwlock lock: there
516 * may be an existing writer waiting for sync phase to
517 * finish. We don't need to worry about such writers, since
518 * sync phase is single-threaded, so the writer can't be
519 * doing anything while we are active.
521 if (dsl_pool_sync_context(dp)) {
522 ASSERT(!DSL_DATASET_IS_DESTROYED(ds));
527 * Normal users will hold the ds_rwlock as a READER until they
528 * are finished (i.e., call dsl_dataset_rele()). "Owners" will
529 * drop their READER lock after they set the ds_owner field.
531 * If the dataset is being destroyed, the destroy thread will
532 * obtain a WRITER lock for exclusive access after it's done its
533 * open-context work and then change the ds_owner to
534 * dsl_reaper once destruction is assured. So threads
535 * may block here temporarily, until the "destructability" of
536 * the dataset is determined.
538 ASSERT(!RW_WRITE_HELD(&dp->dp_config_rwlock));
539 mutex_enter(&ds->ds_lock);
540 while (!rw_tryenter(&ds->ds_rwlock, RW_READER)) {
541 rw_exit(&dp->dp_config_rwlock);
542 cv_wait(&ds->ds_exclusive_cv, &ds->ds_lock);
543 if (DSL_DATASET_IS_DESTROYED(ds)) {
544 mutex_exit(&ds->ds_lock);
545 dsl_dataset_drop_ref(ds, tag);
546 rw_enter(&dp->dp_config_rwlock, RW_READER);
550 * The dp_config_rwlock lives above the ds_lock. And
551 * we need to check DSL_DATASET_IS_DESTROYED() while
552 * holding the ds_lock, so we have to drop and reacquire
555 mutex_exit(&ds->ds_lock);
556 rw_enter(&dp->dp_config_rwlock, RW_READER);
557 mutex_enter(&ds->ds_lock);
559 mutex_exit(&ds->ds_lock);
564 dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag,
567 int err = dsl_dataset_get_ref(dp, dsobj, tag, dsp);
571 return (dsl_dataset_hold_ref(*dsp, tag));
575 dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj, boolean_t inconsistentok,
576 void *tag, dsl_dataset_t **dsp)
578 int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp);
581 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) {
582 dsl_dataset_rele(*dsp, tag);
590 dsl_dataset_hold(const char *name, void *tag, dsl_dataset_t **dsp)
594 const char *snapname;
598 err = dsl_dir_open_spa(NULL, name, FTAG, &dd, &snapname);
603 obj = dd->dd_phys->dd_head_dataset_obj;
604 rw_enter(&dp->dp_config_rwlock, RW_READER);
606 err = dsl_dataset_get_ref(dp, obj, tag, dsp);
612 err = dsl_dataset_hold_ref(*dsp, tag);
614 /* we may be looking for a snapshot */
615 if (err == 0 && snapname != NULL) {
616 dsl_dataset_t *ds = NULL;
618 if (*snapname++ != '@') {
619 dsl_dataset_rele(*dsp, tag);
624 dprintf("looking for snapshot '%s'\n", snapname);
625 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj);
627 err = dsl_dataset_get_ref(dp, obj, tag, &ds);
628 dsl_dataset_rele(*dsp, tag);
630 ASSERT3U((err == 0), ==, (ds != NULL));
633 mutex_enter(&ds->ds_lock);
634 if (ds->ds_snapname[0] == 0)
635 (void) strlcpy(ds->ds_snapname, snapname,
636 sizeof (ds->ds_snapname));
637 mutex_exit(&ds->ds_lock);
638 err = dsl_dataset_hold_ref(ds, tag);
639 *dsp = err ? NULL : ds;
643 rw_exit(&dp->dp_config_rwlock);
644 dsl_dir_close(dd, FTAG);
649 dsl_dataset_own(const char *name, boolean_t inconsistentok,
650 void *tag, dsl_dataset_t **dsp)
652 int err = dsl_dataset_hold(name, tag, dsp);
655 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) {
656 dsl_dataset_rele(*dsp, tag);
663 dsl_dataset_name(dsl_dataset_t *ds, char *name)
666 (void) strcpy(name, "mos");
668 dsl_dir_name(ds->ds_dir, name);
669 VERIFY(0 == dsl_dataset_get_snapname(ds));
670 if (ds->ds_snapname[0]) {
671 (void) strcat(name, "@");
673 * We use a "recursive" mutex so that we
674 * can call dprintf_ds() with ds_lock held.
676 if (!MUTEX_HELD(&ds->ds_lock)) {
677 mutex_enter(&ds->ds_lock);
678 (void) strcat(name, ds->ds_snapname);
679 mutex_exit(&ds->ds_lock);
681 (void) strcat(name, ds->ds_snapname);
688 dsl_dataset_namelen(dsl_dataset_t *ds)
693 result = 3; /* "mos" */
695 result = dsl_dir_namelen(ds->ds_dir);
696 VERIFY(0 == dsl_dataset_get_snapname(ds));
697 if (ds->ds_snapname[0]) {
698 ++result; /* adding one for the @-sign */
699 if (!MUTEX_HELD(&ds->ds_lock)) {
700 mutex_enter(&ds->ds_lock);
701 result += strlen(ds->ds_snapname);
702 mutex_exit(&ds->ds_lock);
704 result += strlen(ds->ds_snapname);
713 dsl_dataset_drop_ref(dsl_dataset_t *ds, void *tag)
715 dmu_buf_rele(ds->ds_dbuf, tag);
719 dsl_dataset_rele(dsl_dataset_t *ds, void *tag)
721 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) {
722 rw_exit(&ds->ds_rwlock);
724 dsl_dataset_drop_ref(ds, tag);
728 dsl_dataset_disown(dsl_dataset_t *ds, void *tag)
730 ASSERT((ds->ds_owner == tag && ds->ds_dbuf) ||
731 (DSL_DATASET_IS_DESTROYED(ds) && ds->ds_dbuf == NULL));
733 mutex_enter(&ds->ds_lock);
735 if (RW_WRITE_HELD(&ds->ds_rwlock)) {
736 rw_exit(&ds->ds_rwlock);
737 cv_broadcast(&ds->ds_exclusive_cv);
739 mutex_exit(&ds->ds_lock);
741 dsl_dataset_drop_ref(ds, tag);
743 dsl_dataset_evict(NULL, ds);
747 dsl_dataset_tryown(dsl_dataset_t *ds, boolean_t inconsistentok, void *tag)
749 boolean_t gotit = FALSE;
751 mutex_enter(&ds->ds_lock);
752 if (ds->ds_owner == NULL &&
753 (!DS_IS_INCONSISTENT(ds) || inconsistentok)) {
755 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool))
756 rw_exit(&ds->ds_rwlock);
759 mutex_exit(&ds->ds_lock);
764 dsl_dataset_make_exclusive(dsl_dataset_t *ds, void *owner)
766 ASSERT3P(owner, ==, ds->ds_owner);
767 if (!RW_WRITE_HELD(&ds->ds_rwlock))
768 rw_enter(&ds->ds_rwlock, RW_WRITER);
772 dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin,
773 uint64_t flags, dmu_tx_t *tx)
775 dsl_pool_t *dp = dd->dd_pool;
777 dsl_dataset_phys_t *dsphys;
779 objset_t *mos = dp->dp_meta_objset;
782 origin = dp->dp_origin_snap;
784 ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp);
785 ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0);
786 ASSERT(dmu_tx_is_syncing(tx));
787 ASSERT(dd->dd_phys->dd_head_dataset_obj == 0);
789 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
790 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
791 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
792 dmu_buf_will_dirty(dbuf, tx);
793 dsphys = dbuf->db_data;
794 bzero(dsphys, sizeof (dsl_dataset_phys_t));
795 dsphys->ds_dir_obj = dd->dd_object;
796 dsphys->ds_flags = flags;
797 dsphys->ds_fsid_guid = unique_create();
799 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
800 sizeof (dsphys->ds_guid));
801 } while (dsphys->ds_guid == 0);
802 dsphys->ds_snapnames_zapobj =
803 zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP,
805 dsphys->ds_creation_time = gethrestime_sec();
806 dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg;
808 if (origin == NULL) {
809 dsphys->ds_deadlist_obj = dsl_deadlist_alloc(mos, tx);
813 dsphys->ds_prev_snap_obj = origin->ds_object;
814 dsphys->ds_prev_snap_txg =
815 origin->ds_phys->ds_creation_txg;
816 dsphys->ds_referenced_bytes =
817 origin->ds_phys->ds_referenced_bytes;
818 dsphys->ds_compressed_bytes =
819 origin->ds_phys->ds_compressed_bytes;
820 dsphys->ds_uncompressed_bytes =
821 origin->ds_phys->ds_uncompressed_bytes;
822 dsphys->ds_bp = origin->ds_phys->ds_bp;
823 dsphys->ds_flags |= origin->ds_phys->ds_flags;
825 dmu_buf_will_dirty(origin->ds_dbuf, tx);
826 origin->ds_phys->ds_num_children++;
828 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
829 origin->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ohds));
830 dsphys->ds_deadlist_obj = dsl_deadlist_clone(&ohds->ds_deadlist,
831 dsphys->ds_prev_snap_txg, dsphys->ds_prev_snap_obj, tx);
832 dsl_dataset_rele(ohds, FTAG);
834 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) {
835 if (origin->ds_phys->ds_next_clones_obj == 0) {
836 origin->ds_phys->ds_next_clones_obj =
838 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx);
840 VERIFY(0 == zap_add_int(mos,
841 origin->ds_phys->ds_next_clones_obj,
845 dmu_buf_will_dirty(dd->dd_dbuf, tx);
846 dd->dd_phys->dd_origin_obj = origin->ds_object;
847 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
848 if (origin->ds_dir->dd_phys->dd_clones == 0) {
849 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx);
850 origin->ds_dir->dd_phys->dd_clones =
852 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
854 VERIFY3U(0, ==, zap_add_int(mos,
855 origin->ds_dir->dd_phys->dd_clones, dsobj, tx));
859 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
860 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
862 dmu_buf_rele(dbuf, FTAG);
864 dmu_buf_will_dirty(dd->dd_dbuf, tx);
865 dd->dd_phys->dd_head_dataset_obj = dsobj;
871 dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname,
872 dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx)
874 dsl_pool_t *dp = pdd->dd_pool;
875 uint64_t dsobj, ddobj;
878 ASSERT(lastname[0] != '@');
880 ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx);
881 VERIFY(0 == dsl_dir_open_obj(dp, ddobj, lastname, FTAG, &dd));
883 dsobj = dsl_dataset_create_sync_dd(dd, origin, flags, tx);
885 dsl_deleg_set_create_perms(dd, tx, cr);
887 dsl_dir_close(dd, FTAG);
890 * If we are creating a clone, make sure we zero out any stale
891 * data from the origin snapshots zil header.
893 if (origin != NULL) {
897 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
898 VERIFY3U(0, ==, dmu_objset_from_ds(ds, &os));
899 bzero(&os->os_zil_header, sizeof (os->os_zil_header));
900 dsl_dataset_dirty(ds, tx);
901 dsl_dataset_rele(ds, FTAG);
908 /* FreeBSD ioctl compat begin */
911 const char *snapname;
915 dsl_check_snap_cb(const char *name, void *arg)
917 struct destroyarg *da = arg;
921 dsname = kmem_asprintf("%s@%s", name, da->snapname);
922 fnvlist_add_boolean(da->nvl, dsname);
923 kmem_free(dsname, strlen(dsname) + 1);
929 dmu_get_recursive_snaps_nvl(const char *fsname, const char *snapname,
932 struct destroyarg *da;
935 da = kmem_zalloc(sizeof (struct destroyarg), KM_SLEEP);
937 da->snapname = snapname;
938 err = dmu_objset_find(fsname, dsl_check_snap_cb, da,
940 kmem_free(da, sizeof (struct destroyarg));
944 /* FreeBSD ioctl compat end */
945 #endif /* __FreeBSD__ */
948 * The snapshots must all be in the same pool.
951 dmu_snapshots_destroy_nvl(nvlist_t *snaps, boolean_t defer, char *failed)
954 dsl_sync_task_t *dst;
957 dsl_sync_task_group_t *dstg;
959 pair = nvlist_next_nvpair(snaps, NULL);
963 err = spa_open(nvpair_name(pair), &spa, FTAG);
966 dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
968 for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL;
969 pair = nvlist_next_nvpair(snaps, pair)) {
972 err = dsl_dataset_own(nvpair_name(pair), B_TRUE, dstg, &ds);
974 struct dsl_ds_destroyarg *dsda;
976 dsl_dataset_make_exclusive(ds, dstg);
977 dsda = kmem_zalloc(sizeof (struct dsl_ds_destroyarg),
981 dsl_sync_task_create(dstg, dsl_dataset_destroy_check,
982 dsl_dataset_destroy_sync, dsda, dstg, 0);
983 } else if (err == ENOENT) {
986 (void) strcpy(failed, nvpair_name(pair));
992 err = dsl_sync_task_group_wait(dstg);
994 for (dst = list_head(&dstg->dstg_tasks); dst;
995 dst = list_next(&dstg->dstg_tasks, dst)) {
996 struct dsl_ds_destroyarg *dsda = dst->dst_arg1;
997 dsl_dataset_t *ds = dsda->ds;
1000 * Return the file system name that triggered the error
1003 dsl_dataset_name(ds, failed);
1005 ASSERT3P(dsda->rm_origin, ==, NULL);
1006 dsl_dataset_disown(ds, dstg);
1007 kmem_free(dsda, sizeof (struct dsl_ds_destroyarg));
1010 dsl_sync_task_group_destroy(dstg);
1011 spa_close(spa, FTAG);
1017 dsl_dataset_might_destroy_origin(dsl_dataset_t *ds)
1019 boolean_t might_destroy = B_FALSE;
1021 mutex_enter(&ds->ds_lock);
1022 if (ds->ds_phys->ds_num_children == 2 && ds->ds_userrefs == 0 &&
1023 DS_IS_DEFER_DESTROY(ds))
1024 might_destroy = B_TRUE;
1025 mutex_exit(&ds->ds_lock);
1027 return (might_destroy);
1031 * If we're removing a clone, and these three conditions are true:
1032 * 1) the clone's origin has no other children
1033 * 2) the clone's origin has no user references
1034 * 3) the clone's origin has been marked for deferred destruction
1035 * Then, prepare to remove the origin as part of this sync task group.
1038 dsl_dataset_origin_rm_prep(struct dsl_ds_destroyarg *dsda, void *tag)
1040 dsl_dataset_t *ds = dsda->ds;
1041 dsl_dataset_t *origin = ds->ds_prev;
1043 if (dsl_dataset_might_destroy_origin(origin)) {
1048 namelen = dsl_dataset_namelen(origin) + 1;
1049 name = kmem_alloc(namelen, KM_SLEEP);
1050 dsl_dataset_name(origin, name);
1052 error = zfs_unmount_snap(name, NULL);
1054 kmem_free(name, namelen);
1058 error = dsl_dataset_own(name, B_TRUE, tag, &origin);
1059 kmem_free(name, namelen);
1062 dsda->rm_origin = origin;
1063 dsl_dataset_make_exclusive(origin, tag);
1070 * ds must be opened as OWNER. On return (whether successful or not),
1071 * ds will be closed and caller can no longer dereference it.
1074 dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer)
1077 dsl_sync_task_group_t *dstg;
1081 struct dsl_ds_destroyarg dsda = { 0 };
1082 dsl_dataset_t dummy_ds = { 0 };
1086 if (dsl_dataset_is_snapshot(ds)) {
1087 /* Destroying a snapshot is simpler */
1088 dsl_dataset_make_exclusive(ds, tag);
1091 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
1092 dsl_dataset_destroy_check, dsl_dataset_destroy_sync,
1094 ASSERT3P(dsda.rm_origin, ==, NULL);
1102 dummy_ds.ds_dir = dd;
1103 dummy_ds.ds_object = ds->ds_object;
1105 if (!spa_feature_is_enabled(dsl_dataset_get_spa(ds),
1106 &spa_feature_table[SPA_FEATURE_ASYNC_DESTROY])) {
1108 * Check for errors and mark this ds as inconsistent, in
1109 * case we crash while freeing the objects.
1111 err = dsl_sync_task_do(dd->dd_pool,
1112 dsl_dataset_destroy_begin_check,
1113 dsl_dataset_destroy_begin_sync, ds, NULL, 0);
1117 err = dmu_objset_from_ds(ds, &os);
1122 * Remove all objects while in the open context so that
1123 * there is less work to do in the syncing context.
1125 for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE,
1126 ds->ds_phys->ds_prev_snap_txg)) {
1128 * Ignore errors, if there is not enough disk space
1129 * we will deal with it in dsl_dataset_destroy_sync().
1131 (void) dmu_free_object(os, obj);
1137 * Sync out all in-flight IO.
1139 txg_wait_synced(dd->dd_pool, 0);
1142 * If we managed to free all the objects in open
1143 * context, the user space accounting should be zero.
1145 if (ds->ds_phys->ds_bp.blk_fill == 0 &&
1146 dmu_objset_userused_enabled(os)) {
1149 ASSERT(zap_count(os, DMU_USERUSED_OBJECT,
1150 &count) != 0 || count == 0);
1151 ASSERT(zap_count(os, DMU_GROUPUSED_OBJECT,
1152 &count) != 0 || count == 0);
1156 rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
1157 err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd);
1158 rw_exit(&dd->dd_pool->dp_config_rwlock);
1164 * Blow away the dsl_dir + head dataset.
1166 dsl_dataset_make_exclusive(ds, tag);
1168 * If we're removing a clone, we might also need to remove its
1172 dsda.need_prep = B_FALSE;
1173 if (dsl_dir_is_clone(dd)) {
1174 err = dsl_dataset_origin_rm_prep(&dsda, tag);
1176 dsl_dir_close(dd, FTAG);
1181 dstg = dsl_sync_task_group_create(ds->ds_dir->dd_pool);
1182 dsl_sync_task_create(dstg, dsl_dataset_destroy_check,
1183 dsl_dataset_destroy_sync, &dsda, tag, 0);
1184 dsl_sync_task_create(dstg, dsl_dir_destroy_check,
1185 dsl_dir_destroy_sync, &dummy_ds, FTAG, 0);
1186 err = dsl_sync_task_group_wait(dstg);
1187 dsl_sync_task_group_destroy(dstg);
1190 * We could be racing against 'zfs release' or 'zfs destroy -d'
1191 * on the origin snap, in which case we can get EBUSY if we
1192 * needed to destroy the origin snap but were not ready to
1195 if (dsda.need_prep) {
1196 ASSERT(err == EBUSY);
1197 ASSERT(dsl_dir_is_clone(dd));
1198 ASSERT(dsda.rm_origin == NULL);
1200 } while (dsda.need_prep);
1202 if (dsda.rm_origin != NULL)
1203 dsl_dataset_disown(dsda.rm_origin, tag);
1205 /* if it is successful, dsl_dir_destroy_sync will close the dd */
1207 dsl_dir_close(dd, FTAG);
1209 dsl_dataset_disown(ds, tag);
1214 dsl_dataset_get_blkptr(dsl_dataset_t *ds)
1216 return (&ds->ds_phys->ds_bp);
1220 dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx)
1222 ASSERT(dmu_tx_is_syncing(tx));
1223 /* If it's the meta-objset, set dp_meta_rootbp */
1225 tx->tx_pool->dp_meta_rootbp = *bp;
1227 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1228 ds->ds_phys->ds_bp = *bp;
1233 dsl_dataset_get_spa(dsl_dataset_t *ds)
1235 return (ds->ds_dir->dd_pool->dp_spa);
1239 dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx)
1243 if (ds == NULL) /* this is the meta-objset */
1246 ASSERT(ds->ds_objset != NULL);
1248 if (ds->ds_phys->ds_next_snap_obj != 0)
1249 panic("dirtying snapshot!");
1251 dp = ds->ds_dir->dd_pool;
1253 if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg) == 0) {
1254 /* up the hold count until we can be written out */
1255 dmu_buf_add_ref(ds->ds_dbuf, ds);
1260 dsl_dataset_is_dirty(dsl_dataset_t *ds)
1262 for (int t = 0; t < TXG_SIZE; t++) {
1263 if (txg_list_member(&ds->ds_dir->dd_pool->dp_dirty_datasets,
1271 * The unique space in the head dataset can be calculated by subtracting
1272 * the space used in the most recent snapshot, that is still being used
1273 * in this file system, from the space currently in use. To figure out
1274 * the space in the most recent snapshot still in use, we need to take
1275 * the total space used in the snapshot and subtract out the space that
1276 * has been freed up since the snapshot was taken.
1279 dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds)
1282 uint64_t dlused, dlcomp, dluncomp;
1284 ASSERT(!dsl_dataset_is_snapshot(ds));
1286 if (ds->ds_phys->ds_prev_snap_obj != 0)
1287 mrs_used = ds->ds_prev->ds_phys->ds_referenced_bytes;
1291 dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp);
1293 ASSERT3U(dlused, <=, mrs_used);
1294 ds->ds_phys->ds_unique_bytes =
1295 ds->ds_phys->ds_referenced_bytes - (mrs_used - dlused);
1297 if (spa_version(ds->ds_dir->dd_pool->dp_spa) >=
1298 SPA_VERSION_UNIQUE_ACCURATE)
1299 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
1309 kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
1310 const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
1312 struct killarg *ka = arg;
1313 dmu_tx_t *tx = ka->tx;
1318 if (zb->zb_level == ZB_ZIL_LEVEL) {
1319 ASSERT(zilog != NULL);
1321 * It's a block in the intent log. It has no
1322 * accounting, so just free it.
1324 dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp);
1326 ASSERT(zilog == NULL);
1327 ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg);
1328 (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE);
1336 dsl_dataset_destroy_begin_check(void *arg1, void *arg2, dmu_tx_t *tx)
1338 dsl_dataset_t *ds = arg1;
1339 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1344 * Can't delete a head dataset if there are snapshots of it.
1345 * (Except if the only snapshots are from the branch we cloned
1348 if (ds->ds_prev != NULL &&
1349 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object)
1353 * This is really a dsl_dir thing, but check it here so that
1354 * we'll be less likely to leave this dataset inconsistent &
1357 err = zap_count(mos, ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count);
1368 dsl_dataset_destroy_begin_sync(void *arg1, void *arg2, dmu_tx_t *tx)
1370 dsl_dataset_t *ds = arg1;
1371 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1373 /* Mark it as inconsistent on-disk, in case we crash */
1374 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1375 ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT;
1377 spa_history_log_internal(LOG_DS_DESTROY_BEGIN, dp->dp_spa, tx,
1378 "dataset = %llu", ds->ds_object);
1382 dsl_dataset_origin_check(struct dsl_ds_destroyarg *dsda, void *tag,
1385 dsl_dataset_t *ds = dsda->ds;
1386 dsl_dataset_t *ds_prev = ds->ds_prev;
1388 if (dsl_dataset_might_destroy_origin(ds_prev)) {
1389 struct dsl_ds_destroyarg ndsda = {0};
1392 * If we're not prepared to remove the origin, don't remove
1395 if (dsda->rm_origin == NULL) {
1396 dsda->need_prep = B_TRUE;
1401 ndsda.is_origin_rm = B_TRUE;
1402 return (dsl_dataset_destroy_check(&ndsda, tag, tx));
1406 * If we're not going to remove the origin after all,
1407 * undo the open context setup.
1409 if (dsda->rm_origin != NULL) {
1410 dsl_dataset_disown(dsda->rm_origin, tag);
1411 dsda->rm_origin = NULL;
1418 * If you add new checks here, you may need to add
1419 * additional checks to the "temporary" case in
1420 * snapshot_check() in dmu_objset.c.
1424 dsl_dataset_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx)
1426 struct dsl_ds_destroyarg *dsda = arg1;
1427 dsl_dataset_t *ds = dsda->ds;
1429 /* we have an owner hold, so noone else can destroy us */
1430 ASSERT(!DSL_DATASET_IS_DESTROYED(ds));
1433 * Only allow deferred destroy on pools that support it.
1434 * NOTE: deferred destroy is only supported on snapshots.
1437 if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
1438 SPA_VERSION_USERREFS)
1440 ASSERT(dsl_dataset_is_snapshot(ds));
1445 * Can't delete a head dataset if there are snapshots of it.
1446 * (Except if the only snapshots are from the branch we cloned
1449 if (ds->ds_prev != NULL &&
1450 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object)
1454 * If we made changes this txg, traverse_dsl_dataset won't find
1457 if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg)
1460 if (dsl_dataset_is_snapshot(ds)) {
1462 * If this snapshot has an elevated user reference count,
1463 * we can't destroy it yet.
1465 if (ds->ds_userrefs > 0 && !dsda->releasing)
1468 mutex_enter(&ds->ds_lock);
1470 * Can't delete a branch point. However, if we're destroying
1471 * a clone and removing its origin due to it having a user
1472 * hold count of 0 and having been marked for deferred destroy,
1473 * it's OK for the origin to have a single clone.
1475 if (ds->ds_phys->ds_num_children >
1476 (dsda->is_origin_rm ? 2 : 1)) {
1477 mutex_exit(&ds->ds_lock);
1480 mutex_exit(&ds->ds_lock);
1481 } else if (dsl_dir_is_clone(ds->ds_dir)) {
1482 return (dsl_dataset_origin_check(dsda, arg2, tx));
1485 /* XXX we should do some i/o error checking... */
1497 dsl_dataset_refs_gone(dmu_buf_t *db, void *argv)
1499 struct refsarg *arg = argv;
1501 mutex_enter(&arg->lock);
1503 cv_signal(&arg->cv);
1504 mutex_exit(&arg->lock);
1508 dsl_dataset_drain_refs(dsl_dataset_t *ds, void *tag)
1512 bzero(&arg, sizeof(arg));
1513 mutex_init(&arg.lock, NULL, MUTEX_DEFAULT, NULL);
1514 cv_init(&arg.cv, NULL, CV_DEFAULT, NULL);
1516 (void) dmu_buf_update_user(ds->ds_dbuf, ds, &arg, &ds->ds_phys,
1517 dsl_dataset_refs_gone);
1518 dmu_buf_rele(ds->ds_dbuf, tag);
1519 mutex_enter(&arg.lock);
1521 cv_wait(&arg.cv, &arg.lock);
1523 mutex_exit(&arg.lock);
1526 mutex_destroy(&arg.lock);
1527 cv_destroy(&arg.cv);
1531 remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj, dmu_tx_t *tx)
1533 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1537 ASSERT(ds->ds_phys->ds_num_children >= 2);
1538 err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx);
1540 * The err should not be ENOENT, but a bug in a previous version
1541 * of the code could cause upgrade_clones_cb() to not set
1542 * ds_next_snap_obj when it should, leading to a missing entry.
1543 * If we knew that the pool was created after
1544 * SPA_VERSION_NEXT_CLONES, we could assert that it isn't
1545 * ENOENT. However, at least we can check that we don't have
1546 * too many entries in the next_clones_obj even after failing to
1549 if (err != ENOENT) {
1552 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj,
1554 ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2);
1558 dsl_dataset_remove_clones_key(dsl_dataset_t *ds, uint64_t mintxg, dmu_tx_t *tx)
1560 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1565 * If it is the old version, dd_clones doesn't exist so we can't
1566 * find the clones, but deadlist_remove_key() is a no-op so it
1569 if (ds->ds_dir->dd_phys->dd_clones == 0)
1572 for (zap_cursor_init(&zc, mos, ds->ds_dir->dd_phys->dd_clones);
1573 zap_cursor_retrieve(&zc, &za) == 0;
1574 zap_cursor_advance(&zc)) {
1575 dsl_dataset_t *clone;
1577 VERIFY3U(0, ==, dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
1578 za.za_first_integer, FTAG, &clone));
1579 if (clone->ds_dir->dd_origin_txg > mintxg) {
1580 dsl_deadlist_remove_key(&clone->ds_deadlist,
1582 dsl_dataset_remove_clones_key(clone, mintxg, tx);
1584 dsl_dataset_rele(clone, FTAG);
1586 zap_cursor_fini(&zc);
1589 struct process_old_arg {
1591 dsl_dataset_t *ds_prev;
1592 boolean_t after_branch_point;
1594 uint64_t used, comp, uncomp;
1598 process_old_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
1600 struct process_old_arg *poa = arg;
1601 dsl_pool_t *dp = poa->ds->ds_dir->dd_pool;
1603 if (bp->blk_birth <= poa->ds->ds_phys->ds_prev_snap_txg) {
1604 dsl_deadlist_insert(&poa->ds->ds_deadlist, bp, tx);
1605 if (poa->ds_prev && !poa->after_branch_point &&
1607 poa->ds_prev->ds_phys->ds_prev_snap_txg) {
1608 poa->ds_prev->ds_phys->ds_unique_bytes +=
1609 bp_get_dsize_sync(dp->dp_spa, bp);
1612 poa->used += bp_get_dsize_sync(dp->dp_spa, bp);
1613 poa->comp += BP_GET_PSIZE(bp);
1614 poa->uncomp += BP_GET_UCSIZE(bp);
1615 dsl_free_sync(poa->pio, dp, tx->tx_txg, bp);
1621 process_old_deadlist(dsl_dataset_t *ds, dsl_dataset_t *ds_prev,
1622 dsl_dataset_t *ds_next, boolean_t after_branch_point, dmu_tx_t *tx)
1624 struct process_old_arg poa = { 0 };
1625 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1626 objset_t *mos = dp->dp_meta_objset;
1628 ASSERT(ds->ds_deadlist.dl_oldfmt);
1629 ASSERT(ds_next->ds_deadlist.dl_oldfmt);
1632 poa.ds_prev = ds_prev;
1633 poa.after_branch_point = after_branch_point;
1634 poa.pio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
1635 VERIFY3U(0, ==, bpobj_iterate(&ds_next->ds_deadlist.dl_bpobj,
1636 process_old_cb, &poa, tx));
1637 VERIFY0(zio_wait(poa.pio));
1638 ASSERT3U(poa.used, ==, ds->ds_phys->ds_unique_bytes);
1640 /* change snapused */
1641 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
1642 -poa.used, -poa.comp, -poa.uncomp, tx);
1644 /* swap next's deadlist to our deadlist */
1645 dsl_deadlist_close(&ds->ds_deadlist);
1646 dsl_deadlist_close(&ds_next->ds_deadlist);
1647 SWITCH64(ds_next->ds_phys->ds_deadlist_obj,
1648 ds->ds_phys->ds_deadlist_obj);
1649 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj);
1650 dsl_deadlist_open(&ds_next->ds_deadlist, mos,
1651 ds_next->ds_phys->ds_deadlist_obj);
1655 old_synchronous_dataset_destroy(dsl_dataset_t *ds, dmu_tx_t *tx)
1661 * Free everything that we point to (that's born after
1662 * the previous snapshot, if we are a clone)
1664 * NB: this should be very quick, because we already
1665 * freed all the objects in open context.
1669 err = traverse_dataset(ds,
1670 ds->ds_phys->ds_prev_snap_txg, TRAVERSE_POST,
1673 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || ds->ds_phys->ds_unique_bytes == 0);
1679 dsl_dataset_destroy_sync(void *arg1, void *tag, dmu_tx_t *tx)
1681 struct dsl_ds_destroyarg *dsda = arg1;
1682 dsl_dataset_t *ds = dsda->ds;
1684 int after_branch_point = FALSE;
1685 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1686 objset_t *mos = dp->dp_meta_objset;
1687 dsl_dataset_t *ds_prev = NULL;
1688 boolean_t wont_destroy;
1691 wont_destroy = (dsda->defer &&
1692 (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1));
1694 ASSERT(ds->ds_owner || wont_destroy);
1695 ASSERT(dsda->defer || ds->ds_phys->ds_num_children <= 1);
1696 ASSERT(ds->ds_prev == NULL ||
1697 ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object);
1698 ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg);
1701 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
1702 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1703 ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY;
1707 /* signal any waiters that this dataset is going away */
1708 mutex_enter(&ds->ds_lock);
1709 ds->ds_owner = dsl_reaper;
1710 cv_broadcast(&ds->ds_exclusive_cv);
1711 mutex_exit(&ds->ds_lock);
1713 /* Remove our reservation */
1714 if (ds->ds_reserved != 0) {
1715 dsl_prop_setarg_t psa;
1718 dsl_prop_setarg_init_uint64(&psa, "refreservation",
1719 (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED),
1721 psa.psa_effective_value = 0; /* predict default value */
1723 dsl_dataset_set_reservation_sync(ds, &psa, tx);
1724 ASSERT0(ds->ds_reserved);
1727 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
1729 dsl_scan_ds_destroyed(ds, tx);
1731 obj = ds->ds_object;
1733 if (ds->ds_phys->ds_prev_snap_obj != 0) {
1735 ds_prev = ds->ds_prev;
1737 VERIFY(0 == dsl_dataset_hold_obj(dp,
1738 ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev));
1740 after_branch_point =
1741 (ds_prev->ds_phys->ds_next_snap_obj != obj);
1743 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx);
1744 if (after_branch_point &&
1745 ds_prev->ds_phys->ds_next_clones_obj != 0) {
1746 remove_from_next_clones(ds_prev, obj, tx);
1747 if (ds->ds_phys->ds_next_snap_obj != 0) {
1748 VERIFY(0 == zap_add_int(mos,
1749 ds_prev->ds_phys->ds_next_clones_obj,
1750 ds->ds_phys->ds_next_snap_obj, tx));
1753 if (after_branch_point &&
1754 ds->ds_phys->ds_next_snap_obj == 0) {
1755 /* This clone is toast. */
1756 ASSERT(ds_prev->ds_phys->ds_num_children > 1);
1757 ds_prev->ds_phys->ds_num_children--;
1760 * If the clone's origin has no other clones, no
1761 * user holds, and has been marked for deferred
1762 * deletion, then we should have done the necessary
1763 * destroy setup for it.
1765 if (ds_prev->ds_phys->ds_num_children == 1 &&
1766 ds_prev->ds_userrefs == 0 &&
1767 DS_IS_DEFER_DESTROY(ds_prev)) {
1768 ASSERT3P(dsda->rm_origin, !=, NULL);
1770 ASSERT3P(dsda->rm_origin, ==, NULL);
1772 } else if (!after_branch_point) {
1773 ds_prev->ds_phys->ds_next_snap_obj =
1774 ds->ds_phys->ds_next_snap_obj;
1778 if (dsl_dataset_is_snapshot(ds)) {
1779 dsl_dataset_t *ds_next;
1780 uint64_t old_unique;
1781 uint64_t used = 0, comp = 0, uncomp = 0;
1783 VERIFY(0 == dsl_dataset_hold_obj(dp,
1784 ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next));
1785 ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj);
1787 old_unique = ds_next->ds_phys->ds_unique_bytes;
1789 dmu_buf_will_dirty(ds_next->ds_dbuf, tx);
1790 ds_next->ds_phys->ds_prev_snap_obj =
1791 ds->ds_phys->ds_prev_snap_obj;
1792 ds_next->ds_phys->ds_prev_snap_txg =
1793 ds->ds_phys->ds_prev_snap_txg;
1794 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
1795 ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0);
1798 if (ds_next->ds_deadlist.dl_oldfmt) {
1799 process_old_deadlist(ds, ds_prev, ds_next,
1800 after_branch_point, tx);
1802 /* Adjust prev's unique space. */
1803 if (ds_prev && !after_branch_point) {
1804 dsl_deadlist_space_range(&ds_next->ds_deadlist,
1805 ds_prev->ds_phys->ds_prev_snap_txg,
1806 ds->ds_phys->ds_prev_snap_txg,
1807 &used, &comp, &uncomp);
1808 ds_prev->ds_phys->ds_unique_bytes += used;
1811 /* Adjust snapused. */
1812 dsl_deadlist_space_range(&ds_next->ds_deadlist,
1813 ds->ds_phys->ds_prev_snap_txg, UINT64_MAX,
1814 &used, &comp, &uncomp);
1815 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
1816 -used, -comp, -uncomp, tx);
1818 /* Move blocks to be freed to pool's free list. */
1819 dsl_deadlist_move_bpobj(&ds_next->ds_deadlist,
1820 &dp->dp_free_bpobj, ds->ds_phys->ds_prev_snap_txg,
1822 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir,
1823 DD_USED_HEAD, used, comp, uncomp, tx);
1825 /* Merge our deadlist into next's and free it. */
1826 dsl_deadlist_merge(&ds_next->ds_deadlist,
1827 ds->ds_phys->ds_deadlist_obj, tx);
1829 dsl_deadlist_close(&ds->ds_deadlist);
1830 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx);
1832 /* Collapse range in clone heads */
1833 dsl_dataset_remove_clones_key(ds,
1834 ds->ds_phys->ds_creation_txg, tx);
1836 if (dsl_dataset_is_snapshot(ds_next)) {
1837 dsl_dataset_t *ds_nextnext;
1840 * Update next's unique to include blocks which
1841 * were previously shared by only this snapshot
1842 * and it. Those blocks will be born after the
1843 * prev snap and before this snap, and will have
1844 * died after the next snap and before the one
1845 * after that (ie. be on the snap after next's
1848 VERIFY(0 == dsl_dataset_hold_obj(dp,
1849 ds_next->ds_phys->ds_next_snap_obj,
1850 FTAG, &ds_nextnext));
1851 dsl_deadlist_space_range(&ds_nextnext->ds_deadlist,
1852 ds->ds_phys->ds_prev_snap_txg,
1853 ds->ds_phys->ds_creation_txg,
1854 &used, &comp, &uncomp);
1855 ds_next->ds_phys->ds_unique_bytes += used;
1856 dsl_dataset_rele(ds_nextnext, FTAG);
1857 ASSERT3P(ds_next->ds_prev, ==, NULL);
1859 /* Collapse range in this head. */
1861 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
1862 ds->ds_dir->dd_phys->dd_head_dataset_obj,
1864 dsl_deadlist_remove_key(&hds->ds_deadlist,
1865 ds->ds_phys->ds_creation_txg, tx);
1866 dsl_dataset_rele(hds, FTAG);
1869 ASSERT3P(ds_next->ds_prev, ==, ds);
1870 dsl_dataset_drop_ref(ds_next->ds_prev, ds_next);
1871 ds_next->ds_prev = NULL;
1873 VERIFY(0 == dsl_dataset_get_ref(dp,
1874 ds->ds_phys->ds_prev_snap_obj,
1875 ds_next, &ds_next->ds_prev));
1878 dsl_dataset_recalc_head_uniq(ds_next);
1881 * Reduce the amount of our unconsmed refreservation
1882 * being charged to our parent by the amount of
1883 * new unique data we have gained.
1885 if (old_unique < ds_next->ds_reserved) {
1887 uint64_t new_unique =
1888 ds_next->ds_phys->ds_unique_bytes;
1890 ASSERT(old_unique <= new_unique);
1891 mrsdelta = MIN(new_unique - old_unique,
1892 ds_next->ds_reserved - old_unique);
1893 dsl_dir_diduse_space(ds->ds_dir,
1894 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx);
1897 dsl_dataset_rele(ds_next, FTAG);
1899 zfeature_info_t *async_destroy =
1900 &spa_feature_table[SPA_FEATURE_ASYNC_DESTROY];
1904 * There's no next snapshot, so this is a head dataset.
1905 * Destroy the deadlist. Unless it's a clone, the
1906 * deadlist should be empty. (If it's a clone, it's
1907 * safe to ignore the deadlist contents.)
1909 dsl_deadlist_close(&ds->ds_deadlist);
1910 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx);
1911 ds->ds_phys->ds_deadlist_obj = 0;
1913 VERIFY3U(0, ==, dmu_objset_from_ds(ds, &os));
1915 if (!spa_feature_is_enabled(dp->dp_spa, async_destroy)) {
1916 err = old_synchronous_dataset_destroy(ds, tx);
1919 * Move the bptree into the pool's list of trees to
1920 * clean up and update space accounting information.
1922 uint64_t used, comp, uncomp;
1924 zil_destroy_sync(dmu_objset_zil(os), tx);
1926 if (!spa_feature_is_active(dp->dp_spa, async_destroy)) {
1927 spa_feature_incr(dp->dp_spa, async_destroy, tx);
1928 dp->dp_bptree_obj = bptree_alloc(mos, tx);
1930 DMU_POOL_DIRECTORY_OBJECT,
1931 DMU_POOL_BPTREE_OBJ, sizeof (uint64_t), 1,
1932 &dp->dp_bptree_obj, tx) == 0);
1935 used = ds->ds_dir->dd_phys->dd_used_bytes;
1936 comp = ds->ds_dir->dd_phys->dd_compressed_bytes;
1937 uncomp = ds->ds_dir->dd_phys->dd_uncompressed_bytes;
1939 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) ||
1940 ds->ds_phys->ds_unique_bytes == used);
1942 bptree_add(mos, dp->dp_bptree_obj,
1943 &ds->ds_phys->ds_bp, ds->ds_phys->ds_prev_snap_txg,
1944 used, comp, uncomp, tx);
1945 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
1946 -used, -comp, -uncomp, tx);
1947 dsl_dir_diduse_space(dp->dp_free_dir, DD_USED_HEAD,
1948 used, comp, uncomp, tx);
1951 if (ds->ds_prev != NULL) {
1952 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
1953 VERIFY3U(0, ==, zap_remove_int(mos,
1954 ds->ds_prev->ds_dir->dd_phys->dd_clones,
1955 ds->ds_object, tx));
1957 dsl_dataset_rele(ds->ds_prev, ds);
1958 ds->ds_prev = ds_prev = NULL;
1963 * This must be done after the dsl_traverse(), because it will
1964 * re-open the objset.
1966 if (ds->ds_objset) {
1967 dmu_objset_evict(ds->ds_objset);
1968 ds->ds_objset = NULL;
1971 if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) {
1972 /* Erase the link in the dir */
1973 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx);
1974 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0;
1975 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0);
1976 err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx);
1979 /* remove from snapshot namespace */
1980 dsl_dataset_t *ds_head;
1981 ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0);
1982 VERIFY(0 == dsl_dataset_hold_obj(dp,
1983 ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head));
1984 VERIFY(0 == dsl_dataset_get_snapname(ds));
1989 err = dsl_dataset_snap_lookup(ds_head,
1990 ds->ds_snapname, &val);
1992 ASSERT3U(val, ==, obj);
1995 err = dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx);
1997 dsl_dataset_rele(ds_head, FTAG);
2000 if (ds_prev && ds->ds_prev != ds_prev)
2001 dsl_dataset_rele(ds_prev, FTAG);
2003 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx);
2004 spa_history_log_internal(LOG_DS_DESTROY, dp->dp_spa, tx,
2005 "dataset = %llu", ds->ds_object);
2007 if (ds->ds_phys->ds_next_clones_obj != 0) {
2009 ASSERT(0 == zap_count(mos,
2010 ds->ds_phys->ds_next_clones_obj, &count) && count == 0);
2011 VERIFY(0 == dmu_object_free(mos,
2012 ds->ds_phys->ds_next_clones_obj, tx));
2014 if (ds->ds_phys->ds_props_obj != 0)
2015 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_props_obj, tx));
2016 if (ds->ds_phys->ds_userrefs_obj != 0)
2017 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx));
2018 dsl_dir_close(ds->ds_dir, ds);
2020 dsl_dataset_drain_refs(ds, tag);
2021 VERIFY(0 == dmu_object_free(mos, obj, tx));
2023 if (dsda->rm_origin) {
2025 * Remove the origin of the clone we just destroyed.
2027 struct dsl_ds_destroyarg ndsda = {0};
2029 ndsda.ds = dsda->rm_origin;
2030 dsl_dataset_destroy_sync(&ndsda, tag, tx);
2035 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx)
2039 if (!dmu_tx_is_syncing(tx))
2043 * If there's an fs-only reservation, any blocks that might become
2044 * owned by the snapshot dataset must be accommodated by space
2045 * outside of the reservation.
2047 ASSERT(ds->ds_reserved == 0 || DS_UNIQUE_IS_ACCURATE(ds));
2048 asize = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
2049 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
2053 * Propogate any reserved space for this snapshot to other
2054 * snapshot checks in this sync group.
2057 dsl_dir_willuse_space(ds->ds_dir, asize, tx);
2063 dsl_dataset_snapshot_check(void *arg1, void *arg2, dmu_tx_t *tx)
2065 dsl_dataset_t *ds = arg1;
2066 const char *snapname = arg2;
2071 * We don't allow multiple snapshots of the same txg. If there
2072 * is already one, try again.
2074 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg)
2078 * Check for conflicting name snapshot name.
2080 err = dsl_dataset_snap_lookup(ds, snapname, &value);
2087 * Check that the dataset's name is not too long. Name consists
2088 * of the dataset's length + 1 for the @-sign + snapshot name's length
2090 if (dsl_dataset_namelen(ds) + 1 + strlen(snapname) >= MAXNAMELEN)
2091 return (ENAMETOOLONG);
2093 err = dsl_dataset_snapshot_reserve_space(ds, tx);
2097 ds->ds_trysnap_txg = tx->tx_txg;
2102 dsl_dataset_snapshot_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2104 dsl_dataset_t *ds = arg1;
2105 const char *snapname = arg2;
2106 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2108 dsl_dataset_phys_t *dsphys;
2109 uint64_t dsobj, crtxg;
2110 objset_t *mos = dp->dp_meta_objset;
2113 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
2116 * The origin's ds_creation_txg has to be < TXG_INITIAL
2118 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0)
2123 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
2124 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
2125 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
2126 dmu_buf_will_dirty(dbuf, tx);
2127 dsphys = dbuf->db_data;
2128 bzero(dsphys, sizeof (dsl_dataset_phys_t));
2129 dsphys->ds_dir_obj = ds->ds_dir->dd_object;
2130 dsphys->ds_fsid_guid = unique_create();
2132 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
2133 sizeof (dsphys->ds_guid));
2134 } while (dsphys->ds_guid == 0);
2135 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj;
2136 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg;
2137 dsphys->ds_next_snap_obj = ds->ds_object;
2138 dsphys->ds_num_children = 1;
2139 dsphys->ds_creation_time = gethrestime_sec();
2140 dsphys->ds_creation_txg = crtxg;
2141 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj;
2142 dsphys->ds_referenced_bytes = ds->ds_phys->ds_referenced_bytes;
2143 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes;
2144 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes;
2145 dsphys->ds_flags = ds->ds_phys->ds_flags;
2146 dsphys->ds_bp = ds->ds_phys->ds_bp;
2147 dmu_buf_rele(dbuf, FTAG);
2149 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0);
2151 uint64_t next_clones_obj =
2152 ds->ds_prev->ds_phys->ds_next_clones_obj;
2153 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj ==
2155 ds->ds_prev->ds_phys->ds_num_children > 1);
2156 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) {
2157 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
2158 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
2159 ds->ds_prev->ds_phys->ds_creation_txg);
2160 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj;
2161 } else if (next_clones_obj != 0) {
2162 remove_from_next_clones(ds->ds_prev,
2163 dsphys->ds_next_snap_obj, tx);
2164 VERIFY3U(0, ==, zap_add_int(mos,
2165 next_clones_obj, dsobj, tx));
2170 * If we have a reference-reservation on this dataset, we will
2171 * need to increase the amount of refreservation being charged
2172 * since our unique space is going to zero.
2174 if (ds->ds_reserved) {
2176 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
2177 delta = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
2178 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV,
2182 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2183 zfs_dbgmsg("taking snapshot %s@%s/%llu; newkey=%llu",
2184 ds->ds_dir->dd_myname, snapname, dsobj,
2185 ds->ds_phys->ds_prev_snap_txg);
2186 ds->ds_phys->ds_deadlist_obj = dsl_deadlist_clone(&ds->ds_deadlist,
2187 UINT64_MAX, ds->ds_phys->ds_prev_snap_obj, tx);
2188 dsl_deadlist_close(&ds->ds_deadlist);
2189 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj);
2190 dsl_deadlist_add_key(&ds->ds_deadlist,
2191 ds->ds_phys->ds_prev_snap_txg, tx);
2193 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg);
2194 ds->ds_phys->ds_prev_snap_obj = dsobj;
2195 ds->ds_phys->ds_prev_snap_txg = crtxg;
2196 ds->ds_phys->ds_unique_bytes = 0;
2197 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
2198 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
2200 err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj,
2201 snapname, 8, 1, &dsobj, tx);
2205 dsl_dataset_drop_ref(ds->ds_prev, ds);
2206 VERIFY(0 == dsl_dataset_get_ref(dp,
2207 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev));
2209 dsl_scan_ds_snapshotted(ds, tx);
2211 dsl_dir_snap_cmtime_update(ds->ds_dir);
2213 spa_history_log_internal(LOG_DS_SNAPSHOT, dp->dp_spa, tx,
2214 "dataset = %llu", dsobj);
2218 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx)
2220 ASSERT(dmu_tx_is_syncing(tx));
2221 ASSERT(ds->ds_objset != NULL);
2222 ASSERT(ds->ds_phys->ds_next_snap_obj == 0);
2225 * in case we had to change ds_fsid_guid when we opened it,
2228 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2229 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid;
2231 dmu_objset_sync(ds->ds_objset, zio, tx);
2235 get_clones_stat(dsl_dataset_t *ds, nvlist_t *nv)
2238 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
2244 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER);
2245 VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2246 VERIFY(nvlist_alloc(&val, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2249 * There may me missing entries in ds_next_clones_obj
2250 * due to a bug in a previous version of the code.
2251 * Only trust it if it has the right number of entries.
2253 if (ds->ds_phys->ds_next_clones_obj != 0) {
2254 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj,
2257 if (count != ds->ds_phys->ds_num_children - 1) {
2260 for (zap_cursor_init(&zc, mos, ds->ds_phys->ds_next_clones_obj);
2261 zap_cursor_retrieve(&zc, &za) == 0;
2262 zap_cursor_advance(&zc)) {
2263 dsl_dataset_t *clone;
2264 char buf[ZFS_MAXNAMELEN];
2266 * Even though we hold the dp_config_rwlock, the dataset
2267 * may fail to open, returning ENOENT. If there is a
2268 * thread concurrently attempting to destroy this
2269 * dataset, it will have the ds_rwlock held for
2270 * RW_WRITER. Our call to dsl_dataset_hold_obj() ->
2271 * dsl_dataset_hold_ref() will fail its
2272 * rw_tryenter(&ds->ds_rwlock, RW_READER), drop the
2273 * dp_config_rwlock, and wait for the destroy progress
2274 * and signal ds_exclusive_cv. If the destroy was
2275 * successful, we will see that
2276 * DSL_DATASET_IS_DESTROYED(), and return ENOENT.
2278 if (dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
2279 za.za_first_integer, FTAG, &clone) != 0)
2281 dsl_dir_name(clone->ds_dir, buf);
2282 VERIFY(nvlist_add_boolean(val, buf) == 0);
2283 dsl_dataset_rele(clone, FTAG);
2285 zap_cursor_fini(&zc);
2286 VERIFY(nvlist_add_nvlist(propval, ZPROP_VALUE, val) == 0);
2287 VERIFY(nvlist_add_nvlist(nv, zfs_prop_to_name(ZFS_PROP_CLONES),
2291 nvlist_free(propval);
2292 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock);
2296 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv)
2298 uint64_t refd, avail, uobjs, aobjs, ratio;
2300 dsl_dir_stats(ds->ds_dir, nv);
2302 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs);
2303 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail);
2304 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd);
2306 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION,
2307 ds->ds_phys->ds_creation_time);
2308 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG,
2309 ds->ds_phys->ds_creation_txg);
2310 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA,
2312 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION,
2314 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID,
2315 ds->ds_phys->ds_guid);
2316 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE,
2317 ds->ds_phys->ds_unique_bytes);
2318 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID,
2320 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS,
2322 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY,
2323 DS_IS_DEFER_DESTROY(ds) ? 1 : 0);
2325 if (ds->ds_phys->ds_prev_snap_obj != 0) {
2326 uint64_t written, comp, uncomp;
2327 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2328 dsl_dataset_t *prev;
2330 rw_enter(&dp->dp_config_rwlock, RW_READER);
2331 int err = dsl_dataset_hold_obj(dp,
2332 ds->ds_phys->ds_prev_snap_obj, FTAG, &prev);
2333 rw_exit(&dp->dp_config_rwlock);
2335 err = dsl_dataset_space_written(prev, ds, &written,
2337 dsl_dataset_rele(prev, FTAG);
2339 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_WRITTEN,
2344 ratio = ds->ds_phys->ds_compressed_bytes == 0 ? 100 :
2345 (ds->ds_phys->ds_uncompressed_bytes * 100 /
2346 ds->ds_phys->ds_compressed_bytes);
2347 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRATIO, ratio);
2348 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_LOGICALREFERENCED,
2349 ds->ds_phys->ds_uncompressed_bytes);
2351 if (ds->ds_phys->ds_next_snap_obj) {
2353 * This is a snapshot; override the dd's space used with
2354 * our unique space and compression ratio.
2356 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED,
2357 ds->ds_phys->ds_unique_bytes);
2358 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, ratio);
2360 get_clones_stat(ds, nv);
2365 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat)
2367 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg;
2368 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT;
2369 stat->dds_guid = ds->ds_phys->ds_guid;
2370 if (ds->ds_phys->ds_next_snap_obj) {
2371 stat->dds_is_snapshot = B_TRUE;
2372 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1;
2374 stat->dds_is_snapshot = B_FALSE;
2375 stat->dds_num_clones = 0;
2378 /* clone origin is really a dsl_dir thing... */
2379 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER);
2380 if (dsl_dir_is_clone(ds->ds_dir)) {
2383 VERIFY(0 == dsl_dataset_get_ref(ds->ds_dir->dd_pool,
2384 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods));
2385 dsl_dataset_name(ods, stat->dds_origin);
2386 dsl_dataset_drop_ref(ods, FTAG);
2388 stat->dds_origin[0] = '\0';
2390 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock);
2394 dsl_dataset_fsid_guid(dsl_dataset_t *ds)
2396 return (ds->ds_fsid_guid);
2400 dsl_dataset_space(dsl_dataset_t *ds,
2401 uint64_t *refdbytesp, uint64_t *availbytesp,
2402 uint64_t *usedobjsp, uint64_t *availobjsp)
2404 *refdbytesp = ds->ds_phys->ds_referenced_bytes;
2405 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE);
2406 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes)
2407 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes;
2408 if (ds->ds_quota != 0) {
2410 * Adjust available bytes according to refquota
2412 if (*refdbytesp < ds->ds_quota)
2413 *availbytesp = MIN(*availbytesp,
2414 ds->ds_quota - *refdbytesp);
2418 *usedobjsp = ds->ds_phys->ds_bp.blk_fill;
2419 *availobjsp = DN_MAX_OBJECT - *usedobjsp;
2423 dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds)
2425 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2427 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) ||
2428 dsl_pool_sync_context(dp));
2429 if (ds->ds_prev == NULL)
2431 if (ds->ds_phys->ds_bp.blk_birth >
2432 ds->ds_prev->ds_phys->ds_creation_txg) {
2433 objset_t *os, *os_prev;
2435 * It may be that only the ZIL differs, because it was
2436 * reset in the head. Don't count that as being
2439 if (dmu_objset_from_ds(ds, &os) != 0)
2441 if (dmu_objset_from_ds(ds->ds_prev, &os_prev) != 0)
2443 return (bcmp(&os->os_phys->os_meta_dnode,
2444 &os_prev->os_phys->os_meta_dnode,
2445 sizeof (os->os_phys->os_meta_dnode)) != 0);
2452 dsl_dataset_snapshot_rename_check(void *arg1, void *arg2, dmu_tx_t *tx)
2454 dsl_dataset_t *ds = arg1;
2455 char *newsnapname = arg2;
2456 dsl_dir_t *dd = ds->ds_dir;
2461 err = dsl_dataset_hold_obj(dd->dd_pool,
2462 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds);
2466 /* new name better not be in use */
2467 err = dsl_dataset_snap_lookup(hds, newsnapname, &val);
2468 dsl_dataset_rele(hds, FTAG);
2472 else if (err == ENOENT)
2475 /* dataset name + 1 for the "@" + the new snapshot name must fit */
2476 if (dsl_dir_namelen(ds->ds_dir) + 1 + strlen(newsnapname) >= MAXNAMELEN)
2483 dsl_dataset_snapshot_rename_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2485 char oldname[MAXPATHLEN], newname[MAXPATHLEN];
2486 dsl_dataset_t *ds = arg1;
2487 const char *newsnapname = arg2;
2488 dsl_dir_t *dd = ds->ds_dir;
2489 objset_t *mos = dd->dd_pool->dp_meta_objset;
2493 ASSERT(ds->ds_phys->ds_next_snap_obj != 0);
2495 VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool,
2496 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds));
2498 VERIFY(0 == dsl_dataset_get_snapname(ds));
2499 err = dsl_dataset_snap_remove(hds, ds->ds_snapname, tx);
2501 dsl_dataset_name(ds, oldname);
2502 mutex_enter(&ds->ds_lock);
2503 (void) strcpy(ds->ds_snapname, newsnapname);
2504 mutex_exit(&ds->ds_lock);
2505 err = zap_add(mos, hds->ds_phys->ds_snapnames_zapobj,
2506 ds->ds_snapname, 8, 1, &ds->ds_object, tx);
2508 dsl_dataset_name(ds, newname);
2510 zvol_rename_minors(oldname, newname);
2513 spa_history_log_internal(LOG_DS_RENAME, dd->dd_pool->dp_spa, tx,
2514 "dataset = %llu", ds->ds_object);
2515 dsl_dataset_rele(hds, FTAG);
2518 struct renamesnaparg {
2519 dsl_sync_task_group_t *dstg;
2520 char failed[MAXPATHLEN];
2527 dsl_snapshot_rename_one(const char *name, void *arg)
2529 struct renamesnaparg *ra = arg;
2530 dsl_dataset_t *ds = NULL;
2534 snapname = kmem_asprintf("%s@%s", name, ra->oldsnap);
2535 (void) strlcpy(ra->failed, snapname, sizeof (ra->failed));
2538 * For recursive snapshot renames the parent won't be changing
2539 * so we just pass name for both the to/from argument.
2541 err = zfs_secpolicy_rename_perms(snapname, snapname, CRED());
2544 return (err == ENOENT ? 0 : err);
2549 * For all filesystems undergoing rename, we'll need to unmount it.
2551 (void) zfs_unmount_snap(snapname, NULL);
2553 err = dsl_dataset_hold(snapname, ra->dstg, &ds);
2556 return (err == ENOENT ? 0 : err);
2558 dsl_sync_task_create(ra->dstg, dsl_dataset_snapshot_rename_check,
2559 dsl_dataset_snapshot_rename_sync, ds, ra->newsnap, 0);
2561 /* First successful rename clears the error. */
2568 dsl_recursive_rename(char *oldname, const char *newname)
2571 struct renamesnaparg *ra;
2572 dsl_sync_task_t *dst;
2574 char *cp, *fsname = spa_strdup(oldname);
2575 int len = strlen(oldname) + 1;
2577 /* truncate the snapshot name to get the fsname */
2578 cp = strchr(fsname, '@');
2581 err = spa_open(fsname, &spa, FTAG);
2583 kmem_free(fsname, len);
2586 ra = kmem_alloc(sizeof (struct renamesnaparg), KM_SLEEP);
2587 ra->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
2589 ra->oldsnap = strchr(oldname, '@') + 1;
2590 ra->newsnap = strchr(newname, '@') + 1;
2594 err = dmu_objset_find(fsname, dsl_snapshot_rename_one, ra,
2596 kmem_free(fsname, len);
2601 err = dsl_sync_task_group_wait(ra->dstg);
2603 for (dst = list_head(&ra->dstg->dstg_tasks); dst;
2604 dst = list_next(&ra->dstg->dstg_tasks, dst)) {
2605 dsl_dataset_t *ds = dst->dst_arg1;
2607 dsl_dir_name(ds->ds_dir, ra->failed);
2608 (void) strlcat(ra->failed, "@", sizeof (ra->failed));
2609 (void) strlcat(ra->failed, ra->newsnap,
2610 sizeof (ra->failed));
2612 dsl_dataset_rele(ds, ra->dstg);
2616 (void) strlcpy(oldname, ra->failed, sizeof (ra->failed));
2618 dsl_sync_task_group_destroy(ra->dstg);
2619 kmem_free(ra, sizeof (struct renamesnaparg));
2620 spa_close(spa, FTAG);
2625 dsl_valid_rename(const char *oldname, void *arg)
2627 int delta = *(int *)arg;
2629 if (strlen(oldname) + delta >= MAXNAMELEN)
2630 return (ENAMETOOLONG);
2635 #pragma weak dmu_objset_rename = dsl_dataset_rename
2637 dsl_dataset_rename(char *oldname, const char *newname, int flags)
2644 err = dsl_dir_open(oldname, FTAG, &dd, &tail);
2649 int delta = strlen(newname) - strlen(oldname);
2651 /* if we're growing, validate child name lengths */
2653 err = dmu_objset_find(oldname, dsl_valid_rename,
2654 &delta, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS);
2657 err = dsl_dir_rename(dd, newname, flags);
2658 dsl_dir_close(dd, FTAG);
2662 if (tail[0] != '@') {
2663 /* the name ended in a nonexistent component */
2664 dsl_dir_close(dd, FTAG);
2668 dsl_dir_close(dd, FTAG);
2670 /* new name must be snapshot in same filesystem */
2671 tail = strchr(newname, '@');
2675 if (strncmp(oldname, newname, tail - newname) != 0)
2678 if (flags & ZFS_RENAME_RECURSIVE) {
2679 err = dsl_recursive_rename(oldname, newname);
2681 err = dsl_dataset_hold(oldname, FTAG, &ds);
2685 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
2686 dsl_dataset_snapshot_rename_check,
2687 dsl_dataset_snapshot_rename_sync, ds, (char *)tail, 1);
2689 dsl_dataset_rele(ds, FTAG);
2695 struct promotenode {
2701 list_t shared_snaps, origin_snaps, clone_snaps;
2702 dsl_dataset_t *origin_origin;
2703 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap;
2707 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep);
2708 static boolean_t snaplist_unstable(list_t *l);
2711 dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx)
2713 dsl_dataset_t *hds = arg1;
2714 struct promotearg *pa = arg2;
2715 struct promotenode *snap = list_head(&pa->shared_snaps);
2716 dsl_dataset_t *origin_ds = snap->ds;
2720 /* Check that it is a real clone */
2721 if (!dsl_dir_is_clone(hds->ds_dir))
2724 /* Since this is so expensive, don't do the preliminary check */
2725 if (!dmu_tx_is_syncing(tx))
2728 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE)
2731 /* compute origin's new unique space */
2732 snap = list_tail(&pa->clone_snaps);
2733 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2734 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2735 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX,
2736 &pa->unique, &unused, &unused);
2739 * Walk the snapshots that we are moving
2741 * Compute space to transfer. Consider the incremental changes
2742 * to used for each snapshot:
2743 * (my used) = (prev's used) + (blocks born) - (blocks killed)
2744 * So each snapshot gave birth to:
2745 * (blocks born) = (my used) - (prev's used) + (blocks killed)
2746 * So a sequence would look like:
2747 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0)
2748 * Which simplifies to:
2749 * uN + kN + kN-1 + ... + k1 + k0
2750 * Note however, if we stop before we reach the ORIGIN we get:
2751 * uN + kN + kN-1 + ... + kM - uM-1
2753 pa->used = origin_ds->ds_phys->ds_referenced_bytes;
2754 pa->comp = origin_ds->ds_phys->ds_compressed_bytes;
2755 pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes;
2756 for (snap = list_head(&pa->shared_snaps); snap;
2757 snap = list_next(&pa->shared_snaps, snap)) {
2758 uint64_t val, dlused, dlcomp, dluncomp;
2759 dsl_dataset_t *ds = snap->ds;
2761 /* Check that the snapshot name does not conflict */
2762 VERIFY(0 == dsl_dataset_get_snapname(ds));
2763 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val);
2771 /* The very first snapshot does not have a deadlist */
2772 if (ds->ds_phys->ds_prev_snap_obj == 0)
2775 dsl_deadlist_space(&ds->ds_deadlist,
2776 &dlused, &dlcomp, &dluncomp);
2779 pa->uncomp += dluncomp;
2783 * If we are a clone of a clone then we never reached ORIGIN,
2784 * so we need to subtract out the clone origin's used space.
2786 if (pa->origin_origin) {
2787 pa->used -= pa->origin_origin->ds_phys->ds_referenced_bytes;
2788 pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes;
2789 pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes;
2792 /* Check that there is enough space here */
2793 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir,
2799 * Compute the amounts of space that will be used by snapshots
2800 * after the promotion (for both origin and clone). For each,
2801 * it is the amount of space that will be on all of their
2802 * deadlists (that was not born before their new origin).
2804 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2808 * Note, typically this will not be a clone of a clone,
2809 * so dd_origin_txg will be < TXG_INITIAL, so
2810 * these snaplist_space() -> dsl_deadlist_space_range()
2811 * calls will be fast because they do not have to
2812 * iterate over all bps.
2814 snap = list_head(&pa->origin_snaps);
2815 err = snaplist_space(&pa->shared_snaps,
2816 snap->ds->ds_dir->dd_origin_txg, &pa->cloneusedsnap);
2820 err = snaplist_space(&pa->clone_snaps,
2821 snap->ds->ds_dir->dd_origin_txg, &space);
2824 pa->cloneusedsnap += space;
2826 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2827 err = snaplist_space(&pa->origin_snaps,
2828 origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap);
2835 pa->err_ds = snap->ds->ds_snapname;
2840 dsl_dataset_promote_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2842 dsl_dataset_t *hds = arg1;
2843 struct promotearg *pa = arg2;
2844 struct promotenode *snap = list_head(&pa->shared_snaps);
2845 dsl_dataset_t *origin_ds = snap->ds;
2846 dsl_dataset_t *origin_head;
2847 dsl_dir_t *dd = hds->ds_dir;
2848 dsl_pool_t *dp = hds->ds_dir->dd_pool;
2849 dsl_dir_t *odd = NULL;
2850 uint64_t oldnext_obj;
2853 ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE));
2855 snap = list_head(&pa->origin_snaps);
2856 origin_head = snap->ds;
2859 * We need to explicitly open odd, since origin_ds's dd will be
2862 VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object,
2865 /* change origin's next snap */
2866 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx);
2867 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj;
2868 snap = list_tail(&pa->clone_snaps);
2869 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2870 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object;
2872 /* change the origin's next clone */
2873 if (origin_ds->ds_phys->ds_next_clones_obj) {
2874 remove_from_next_clones(origin_ds, snap->ds->ds_object, tx);
2875 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2876 origin_ds->ds_phys->ds_next_clones_obj,
2881 dmu_buf_will_dirty(dd->dd_dbuf, tx);
2882 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object);
2883 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj;
2884 dd->dd_origin_txg = origin_head->ds_dir->dd_origin_txg;
2885 dmu_buf_will_dirty(odd->dd_dbuf, tx);
2886 odd->dd_phys->dd_origin_obj = origin_ds->ds_object;
2887 origin_head->ds_dir->dd_origin_txg =
2888 origin_ds->ds_phys->ds_creation_txg;
2890 /* change dd_clone entries */
2891 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2892 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
2893 odd->dd_phys->dd_clones, hds->ds_object, tx));
2894 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2895 pa->origin_origin->ds_dir->dd_phys->dd_clones,
2896 hds->ds_object, tx));
2898 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
2899 pa->origin_origin->ds_dir->dd_phys->dd_clones,
2900 origin_head->ds_object, tx));
2901 if (dd->dd_phys->dd_clones == 0) {
2902 dd->dd_phys->dd_clones = zap_create(dp->dp_meta_objset,
2903 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
2905 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2906 dd->dd_phys->dd_clones, origin_head->ds_object, tx));
2910 /* move snapshots to this dir */
2911 for (snap = list_head(&pa->shared_snaps); snap;
2912 snap = list_next(&pa->shared_snaps, snap)) {
2913 dsl_dataset_t *ds = snap->ds;
2915 /* unregister props as dsl_dir is changing */
2916 if (ds->ds_objset) {
2917 dmu_objset_evict(ds->ds_objset);
2918 ds->ds_objset = NULL;
2920 /* move snap name entry */
2921 VERIFY(0 == dsl_dataset_get_snapname(ds));
2922 VERIFY(0 == dsl_dataset_snap_remove(origin_head,
2923 ds->ds_snapname, tx));
2924 VERIFY(0 == zap_add(dp->dp_meta_objset,
2925 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname,
2926 8, 1, &ds->ds_object, tx));
2928 /* change containing dsl_dir */
2929 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2930 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object);
2931 ds->ds_phys->ds_dir_obj = dd->dd_object;
2932 ASSERT3P(ds->ds_dir, ==, odd);
2933 dsl_dir_close(ds->ds_dir, ds);
2934 VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object,
2935 NULL, ds, &ds->ds_dir));
2937 /* move any clone references */
2938 if (ds->ds_phys->ds_next_clones_obj &&
2939 spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2943 for (zap_cursor_init(&zc, dp->dp_meta_objset,
2944 ds->ds_phys->ds_next_clones_obj);
2945 zap_cursor_retrieve(&zc, &za) == 0;
2946 zap_cursor_advance(&zc)) {
2947 dsl_dataset_t *cnds;
2950 if (za.za_first_integer == oldnext_obj) {
2952 * We've already moved the
2953 * origin's reference.
2958 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
2959 za.za_first_integer, FTAG, &cnds));
2960 o = cnds->ds_dir->dd_phys->dd_head_dataset_obj;
2962 VERIFY3U(zap_remove_int(dp->dp_meta_objset,
2963 odd->dd_phys->dd_clones, o, tx), ==, 0);
2964 VERIFY3U(zap_add_int(dp->dp_meta_objset,
2965 dd->dd_phys->dd_clones, o, tx), ==, 0);
2966 dsl_dataset_rele(cnds, FTAG);
2968 zap_cursor_fini(&zc);
2971 ASSERT0(dsl_prop_numcb(ds));
2975 * Change space accounting.
2976 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either
2977 * both be valid, or both be 0 (resulting in delta == 0). This
2978 * is true for each of {clone,origin} independently.
2981 delta = pa->cloneusedsnap -
2982 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2983 ASSERT3S(delta, >=, 0);
2984 ASSERT3U(pa->used, >=, delta);
2985 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx);
2986 dsl_dir_diduse_space(dd, DD_USED_HEAD,
2987 pa->used - delta, pa->comp, pa->uncomp, tx);
2989 delta = pa->originusedsnap -
2990 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2991 ASSERT3S(delta, <=, 0);
2992 ASSERT3U(pa->used, >=, -delta);
2993 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx);
2994 dsl_dir_diduse_space(odd, DD_USED_HEAD,
2995 -pa->used - delta, -pa->comp, -pa->uncomp, tx);
2997 origin_ds->ds_phys->ds_unique_bytes = pa->unique;
2999 /* log history record */
3000 spa_history_log_internal(LOG_DS_PROMOTE, dd->dd_pool->dp_spa, tx,
3001 "dataset = %llu", hds->ds_object);
3003 dsl_dir_close(odd, FTAG);
3006 static char *snaplist_tag = "snaplist";
3008 * Make a list of dsl_dataset_t's for the snapshots between first_obj
3009 * (exclusive) and last_obj (inclusive). The list will be in reverse
3010 * order (last_obj will be the list_head()). If first_obj == 0, do all
3011 * snapshots back to this dataset's origin.
3014 snaplist_make(dsl_pool_t *dp, boolean_t own,
3015 uint64_t first_obj, uint64_t last_obj, list_t *l)
3017 uint64_t obj = last_obj;
3019 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock));
3021 list_create(l, sizeof (struct promotenode),
3022 offsetof(struct promotenode, link));
3024 while (obj != first_obj) {
3026 struct promotenode *snap;
3030 err = dsl_dataset_own_obj(dp, obj,
3031 0, snaplist_tag, &ds);
3033 dsl_dataset_make_exclusive(ds, snaplist_tag);
3035 err = dsl_dataset_hold_obj(dp, obj, snaplist_tag, &ds);
3037 if (err == ENOENT) {
3038 /* lost race with snapshot destroy */
3039 struct promotenode *last = list_tail(l);
3040 ASSERT(obj != last->ds->ds_phys->ds_prev_snap_obj);
3041 obj = last->ds->ds_phys->ds_prev_snap_obj;
3048 first_obj = ds->ds_dir->dd_phys->dd_origin_obj;
3050 snap = kmem_alloc(sizeof (struct promotenode), KM_SLEEP);
3052 list_insert_tail(l, snap);
3053 obj = ds->ds_phys->ds_prev_snap_obj;
3060 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep)
3062 struct promotenode *snap;
3065 for (snap = list_head(l); snap; snap = list_next(l, snap)) {
3066 uint64_t used, comp, uncomp;
3067 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
3068 mintxg, UINT64_MAX, &used, &comp, &uncomp);
3075 snaplist_destroy(list_t *l, boolean_t own)
3077 struct promotenode *snap;
3079 if (!l || !list_link_active(&l->list_head))
3082 while ((snap = list_tail(l)) != NULL) {
3083 list_remove(l, snap);
3085 dsl_dataset_disown(snap->ds, snaplist_tag);
3087 dsl_dataset_rele(snap->ds, snaplist_tag);
3088 kmem_free(snap, sizeof (struct promotenode));
3094 * Promote a clone. Nomenclature note:
3095 * "clone" or "cds": the original clone which is being promoted
3096 * "origin" or "ods": the snapshot which is originally clone's origin
3097 * "origin head" or "ohds": the dataset which is the head
3098 * (filesystem/volume) for the origin
3099 * "origin origin": the origin of the origin's filesystem (typically
3100 * NULL, indicating that the clone is not a clone of a clone).
3103 dsl_dataset_promote(const char *name, char *conflsnap)
3108 dmu_object_info_t doi;
3109 struct promotearg pa = { 0 };
3110 struct promotenode *snap;
3113 err = dsl_dataset_hold(name, FTAG, &ds);
3119 err = dmu_object_info(dp->dp_meta_objset,
3120 ds->ds_phys->ds_snapnames_zapobj, &doi);
3122 dsl_dataset_rele(ds, FTAG);
3126 if (dsl_dataset_is_snapshot(ds) || dd->dd_phys->dd_origin_obj == 0) {
3127 dsl_dataset_rele(ds, FTAG);
3132 * We are going to inherit all the snapshots taken before our
3133 * origin (i.e., our new origin will be our parent's origin).
3134 * Take ownership of them so that we can rename them into our
3137 rw_enter(&dp->dp_config_rwlock, RW_READER);
3139 err = snaplist_make(dp, B_TRUE, 0, dd->dd_phys->dd_origin_obj,
3144 err = snaplist_make(dp, B_FALSE, 0, ds->ds_object, &pa.clone_snaps);
3148 snap = list_head(&pa.shared_snaps);
3149 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj);
3150 err = snaplist_make(dp, B_FALSE, dd->dd_phys->dd_origin_obj,
3151 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj, &pa.origin_snaps);
3155 if (snap->ds->ds_dir->dd_phys->dd_origin_obj != 0) {
3156 err = dsl_dataset_hold_obj(dp,
3157 snap->ds->ds_dir->dd_phys->dd_origin_obj,
3158 FTAG, &pa.origin_origin);
3164 rw_exit(&dp->dp_config_rwlock);
3167 * Add in 128x the snapnames zapobj size, since we will be moving
3168 * a bunch of snapnames to the promoted ds, and dirtying their
3172 err = dsl_sync_task_do(dp, dsl_dataset_promote_check,
3173 dsl_dataset_promote_sync, ds, &pa,
3174 2 + 2 * doi.doi_physical_blocks_512);
3175 if (err && pa.err_ds && conflsnap)
3176 (void) strncpy(conflsnap, pa.err_ds, MAXNAMELEN);
3179 snaplist_destroy(&pa.shared_snaps, B_TRUE);
3180 snaplist_destroy(&pa.clone_snaps, B_FALSE);
3181 snaplist_destroy(&pa.origin_snaps, B_FALSE);
3182 if (pa.origin_origin)
3183 dsl_dataset_rele(pa.origin_origin, FTAG);
3184 dsl_dataset_rele(ds, FTAG);
3188 struct cloneswaparg {
3189 dsl_dataset_t *cds; /* clone dataset */
3190 dsl_dataset_t *ohds; /* origin's head dataset */
3192 int64_t unused_refres_delta; /* change in unconsumed refreservation */
3197 dsl_dataset_clone_swap_check(void *arg1, void *arg2, dmu_tx_t *tx)
3199 struct cloneswaparg *csa = arg1;
3201 /* they should both be heads */
3202 if (dsl_dataset_is_snapshot(csa->cds) ||
3203 dsl_dataset_is_snapshot(csa->ohds))
3206 /* the branch point should be just before them */
3207 if (csa->cds->ds_prev != csa->ohds->ds_prev)
3210 /* cds should be the clone (unless they are unrelated) */
3211 if (csa->cds->ds_prev != NULL &&
3212 csa->cds->ds_prev != csa->cds->ds_dir->dd_pool->dp_origin_snap &&
3213 csa->ohds->ds_object !=
3214 csa->cds->ds_prev->ds_phys->ds_next_snap_obj)
3217 /* the clone should be a child of the origin */
3218 if (csa->cds->ds_dir->dd_parent != csa->ohds->ds_dir)
3221 /* ohds shouldn't be modified unless 'force' */
3222 if (!csa->force && dsl_dataset_modified_since_lastsnap(csa->ohds))
3225 /* adjust amount of any unconsumed refreservation */
3226 csa->unused_refres_delta =
3227 (int64_t)MIN(csa->ohds->ds_reserved,
3228 csa->ohds->ds_phys->ds_unique_bytes) -
3229 (int64_t)MIN(csa->ohds->ds_reserved,
3230 csa->cds->ds_phys->ds_unique_bytes);
3232 if (csa->unused_refres_delta > 0 &&
3233 csa->unused_refres_delta >
3234 dsl_dir_space_available(csa->ohds->ds_dir, NULL, 0, TRUE))
3237 if (csa->ohds->ds_quota != 0 &&
3238 csa->cds->ds_phys->ds_unique_bytes > csa->ohds->ds_quota)
3246 dsl_dataset_clone_swap_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3248 struct cloneswaparg *csa = arg1;
3249 dsl_pool_t *dp = csa->cds->ds_dir->dd_pool;
3251 ASSERT(csa->cds->ds_reserved == 0);
3252 ASSERT(csa->ohds->ds_quota == 0 ||
3253 csa->cds->ds_phys->ds_unique_bytes <= csa->ohds->ds_quota);
3255 dmu_buf_will_dirty(csa->cds->ds_dbuf, tx);
3256 dmu_buf_will_dirty(csa->ohds->ds_dbuf, tx);
3258 if (csa->cds->ds_objset != NULL) {
3259 dmu_objset_evict(csa->cds->ds_objset);
3260 csa->cds->ds_objset = NULL;
3263 if (csa->ohds->ds_objset != NULL) {
3264 dmu_objset_evict(csa->ohds->ds_objset);
3265 csa->ohds->ds_objset = NULL;
3269 * Reset origin's unique bytes, if it exists.
3271 if (csa->cds->ds_prev) {
3272 dsl_dataset_t *origin = csa->cds->ds_prev;
3273 uint64_t comp, uncomp;
3275 dmu_buf_will_dirty(origin->ds_dbuf, tx);
3276 dsl_deadlist_space_range(&csa->cds->ds_deadlist,
3277 origin->ds_phys->ds_prev_snap_txg, UINT64_MAX,
3278 &origin->ds_phys->ds_unique_bytes, &comp, &uncomp);
3284 tmp = csa->ohds->ds_phys->ds_bp;
3285 csa->ohds->ds_phys->ds_bp = csa->cds->ds_phys->ds_bp;
3286 csa->cds->ds_phys->ds_bp = tmp;
3289 /* set dd_*_bytes */
3291 int64_t dused, dcomp, duncomp;
3292 uint64_t cdl_used, cdl_comp, cdl_uncomp;
3293 uint64_t odl_used, odl_comp, odl_uncomp;
3295 ASSERT3U(csa->cds->ds_dir->dd_phys->
3296 dd_used_breakdown[DD_USED_SNAP], ==, 0);
3298 dsl_deadlist_space(&csa->cds->ds_deadlist,
3299 &cdl_used, &cdl_comp, &cdl_uncomp);
3300 dsl_deadlist_space(&csa->ohds->ds_deadlist,
3301 &odl_used, &odl_comp, &odl_uncomp);
3303 dused = csa->cds->ds_phys->ds_referenced_bytes + cdl_used -
3304 (csa->ohds->ds_phys->ds_referenced_bytes + odl_used);
3305 dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp -
3306 (csa->ohds->ds_phys->ds_compressed_bytes + odl_comp);
3307 duncomp = csa->cds->ds_phys->ds_uncompressed_bytes +
3309 (csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp);
3311 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD,
3312 dused, dcomp, duncomp, tx);
3313 dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD,
3314 -dused, -dcomp, -duncomp, tx);
3317 * The difference in the space used by snapshots is the
3318 * difference in snapshot space due to the head's
3319 * deadlist (since that's the only thing that's
3320 * changing that affects the snapused).
3322 dsl_deadlist_space_range(&csa->cds->ds_deadlist,
3323 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX,
3324 &cdl_used, &cdl_comp, &cdl_uncomp);
3325 dsl_deadlist_space_range(&csa->ohds->ds_deadlist,
3326 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX,
3327 &odl_used, &odl_comp, &odl_uncomp);
3328 dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used,
3329 DD_USED_HEAD, DD_USED_SNAP, tx);
3332 /* swap ds_*_bytes */
3333 SWITCH64(csa->ohds->ds_phys->ds_referenced_bytes,
3334 csa->cds->ds_phys->ds_referenced_bytes);
3335 SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes,
3336 csa->cds->ds_phys->ds_compressed_bytes);
3337 SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes,
3338 csa->cds->ds_phys->ds_uncompressed_bytes);
3339 SWITCH64(csa->ohds->ds_phys->ds_unique_bytes,
3340 csa->cds->ds_phys->ds_unique_bytes);
3342 /* apply any parent delta for change in unconsumed refreservation */
3343 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV,
3344 csa->unused_refres_delta, 0, 0, tx);
3349 dsl_deadlist_close(&csa->cds->ds_deadlist);
3350 dsl_deadlist_close(&csa->ohds->ds_deadlist);
3351 SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj,
3352 csa->cds->ds_phys->ds_deadlist_obj);
3353 dsl_deadlist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset,
3354 csa->cds->ds_phys->ds_deadlist_obj);
3355 dsl_deadlist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset,
3356 csa->ohds->ds_phys->ds_deadlist_obj);
3358 dsl_scan_ds_clone_swapped(csa->ohds, csa->cds, tx);
3362 * Swap 'clone' with its origin head datasets. Used at the end of "zfs
3363 * recv" into an existing fs to swizzle the file system to the new
3364 * version, and by "zfs rollback". Can also be used to swap two
3365 * independent head datasets if neither has any snapshots.
3368 dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head,
3371 struct cloneswaparg csa;
3374 ASSERT(clone->ds_owner);
3375 ASSERT(origin_head->ds_owner);
3378 * Need exclusive access for the swap. If we're swapping these
3379 * datasets back after an error, we already hold the locks.
3381 if (!RW_WRITE_HELD(&clone->ds_rwlock))
3382 rw_enter(&clone->ds_rwlock, RW_WRITER);
3383 if (!RW_WRITE_HELD(&origin_head->ds_rwlock) &&
3384 !rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) {
3385 rw_exit(&clone->ds_rwlock);
3386 rw_enter(&origin_head->ds_rwlock, RW_WRITER);
3387 if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) {
3388 rw_exit(&origin_head->ds_rwlock);
3393 csa.ohds = origin_head;
3395 error = dsl_sync_task_do(clone->ds_dir->dd_pool,
3396 dsl_dataset_clone_swap_check,
3397 dsl_dataset_clone_swap_sync, &csa, NULL, 9);
3402 * Given a pool name and a dataset object number in that pool,
3403 * return the name of that dataset.
3406 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf)
3413 if ((error = spa_open(pname, &spa, FTAG)) != 0)
3415 dp = spa_get_dsl(spa);
3416 rw_enter(&dp->dp_config_rwlock, RW_READER);
3417 if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) {
3418 dsl_dataset_name(ds, buf);
3419 dsl_dataset_rele(ds, FTAG);
3421 rw_exit(&dp->dp_config_rwlock);
3422 spa_close(spa, FTAG);
3428 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota,
3429 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv)
3433 ASSERT3S(asize, >, 0);
3436 * *ref_rsrv is the portion of asize that will come from any
3437 * unconsumed refreservation space.
3441 mutex_enter(&ds->ds_lock);
3443 * Make a space adjustment for reserved bytes.
3445 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) {
3447 ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
3448 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
3450 asize - MIN(asize, parent_delta(ds, asize + inflight));
3453 if (!check_quota || ds->ds_quota == 0) {
3454 mutex_exit(&ds->ds_lock);
3458 * If they are requesting more space, and our current estimate
3459 * is over quota, they get to try again unless the actual
3460 * on-disk is over quota and there are no pending changes (which
3461 * may free up space for us).
3463 if (ds->ds_phys->ds_referenced_bytes + inflight >= ds->ds_quota) {
3465 ds->ds_phys->ds_referenced_bytes < ds->ds_quota)
3470 mutex_exit(&ds->ds_lock);
3477 dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx)
3479 dsl_dataset_t *ds = arg1;
3480 dsl_prop_setarg_t *psa = arg2;
3483 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA)
3486 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0)
3489 if (psa->psa_effective_value == 0)
3492 if (psa->psa_effective_value < ds->ds_phys->ds_referenced_bytes ||
3493 psa->psa_effective_value < ds->ds_reserved)
3499 extern void dsl_prop_set_sync(void *, void *, dmu_tx_t *);
3502 dsl_dataset_set_quota_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3504 dsl_dataset_t *ds = arg1;
3505 dsl_prop_setarg_t *psa = arg2;
3506 uint64_t effective_value = psa->psa_effective_value;
3508 dsl_prop_set_sync(ds, psa, tx);
3509 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa);
3511 if (ds->ds_quota != effective_value) {
3512 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3513 ds->ds_quota = effective_value;
3518 dsl_dataset_set_quota(const char *dsname, zprop_source_t source, uint64_t quota)
3521 dsl_prop_setarg_t psa;
3524 dsl_prop_setarg_init_uint64(&psa, "refquota", source, "a);
3526 err = dsl_dataset_hold(dsname, FTAG, &ds);
3531 * If someone removes a file, then tries to set the quota, we
3532 * want to make sure the file freeing takes effect.
3534 txg_wait_open(ds->ds_dir->dd_pool, 0);
3536 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
3537 dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync,
3540 dsl_dataset_rele(ds, FTAG);
3545 dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx)
3547 dsl_dataset_t *ds = arg1;
3548 dsl_prop_setarg_t *psa = arg2;
3549 uint64_t effective_value;
3553 if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
3554 SPA_VERSION_REFRESERVATION)
3557 if (dsl_dataset_is_snapshot(ds))
3560 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0)
3563 effective_value = psa->psa_effective_value;
3566 * If we are doing the preliminary check in open context, the
3567 * space estimates may be inaccurate.
3569 if (!dmu_tx_is_syncing(tx))
3572 mutex_enter(&ds->ds_lock);
3573 if (!DS_UNIQUE_IS_ACCURATE(ds))
3574 dsl_dataset_recalc_head_uniq(ds);
3575 unique = ds->ds_phys->ds_unique_bytes;
3576 mutex_exit(&ds->ds_lock);
3578 if (MAX(unique, effective_value) > MAX(unique, ds->ds_reserved)) {
3579 uint64_t delta = MAX(unique, effective_value) -
3580 MAX(unique, ds->ds_reserved);
3582 if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
3584 if (ds->ds_quota > 0 &&
3585 effective_value > ds->ds_quota)
3593 dsl_dataset_set_reservation_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3595 dsl_dataset_t *ds = arg1;
3596 dsl_prop_setarg_t *psa = arg2;
3597 uint64_t effective_value = psa->psa_effective_value;
3601 dsl_prop_set_sync(ds, psa, tx);
3602 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa);
3604 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3606 mutex_enter(&ds->ds_dir->dd_lock);
3607 mutex_enter(&ds->ds_lock);
3608 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
3609 unique = ds->ds_phys->ds_unique_bytes;
3610 delta = MAX(0, (int64_t)(effective_value - unique)) -
3611 MAX(0, (int64_t)(ds->ds_reserved - unique));
3612 ds->ds_reserved = effective_value;
3613 mutex_exit(&ds->ds_lock);
3615 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx);
3616 mutex_exit(&ds->ds_dir->dd_lock);
3620 dsl_dataset_set_reservation(const char *dsname, zprop_source_t source,
3621 uint64_t reservation)
3624 dsl_prop_setarg_t psa;
3627 dsl_prop_setarg_init_uint64(&psa, "refreservation", source,
3630 err = dsl_dataset_hold(dsname, FTAG, &ds);
3634 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
3635 dsl_dataset_set_reservation_check,
3636 dsl_dataset_set_reservation_sync, ds, &psa, 0);
3638 dsl_dataset_rele(ds, FTAG);
3642 typedef struct zfs_hold_cleanup_arg {
3645 char htag[MAXNAMELEN];
3646 } zfs_hold_cleanup_arg_t;
3649 dsl_dataset_user_release_onexit(void *arg)
3651 zfs_hold_cleanup_arg_t *ca = arg;
3653 (void) dsl_dataset_user_release_tmp(ca->dp, ca->dsobj, ca->htag,
3655 kmem_free(ca, sizeof (zfs_hold_cleanup_arg_t));
3659 dsl_register_onexit_hold_cleanup(dsl_dataset_t *ds, const char *htag,
3662 zfs_hold_cleanup_arg_t *ca;
3664 ca = kmem_alloc(sizeof (zfs_hold_cleanup_arg_t), KM_SLEEP);
3665 ca->dp = ds->ds_dir->dd_pool;
3666 ca->dsobj = ds->ds_object;
3667 (void) strlcpy(ca->htag, htag, sizeof (ca->htag));
3668 VERIFY3U(0, ==, zfs_onexit_add_cb(minor,
3669 dsl_dataset_user_release_onexit, ca, NULL));
3673 * If you add new checks here, you may need to add
3674 * additional checks to the "temporary" case in
3675 * snapshot_check() in dmu_objset.c.
3678 dsl_dataset_user_hold_check(void *arg1, void *arg2, dmu_tx_t *tx)
3680 dsl_dataset_t *ds = arg1;
3681 struct dsl_ds_holdarg *ha = arg2;
3682 char *htag = ha->htag;
3683 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3686 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS)
3689 if (!dsl_dataset_is_snapshot(ds))
3692 /* tags must be unique */
3693 mutex_enter(&ds->ds_lock);
3694 if (ds->ds_phys->ds_userrefs_obj) {
3695 error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj, htag,
3699 else if (error == ENOENT)
3702 mutex_exit(&ds->ds_lock);
3704 if (error == 0 && ha->temphold &&
3705 strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN)
3712 dsl_dataset_user_hold_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3714 dsl_dataset_t *ds = arg1;
3715 struct dsl_ds_holdarg *ha = arg2;
3716 char *htag = ha->htag;
3717 dsl_pool_t *dp = ds->ds_dir->dd_pool;
3718 objset_t *mos = dp->dp_meta_objset;
3719 uint64_t now = gethrestime_sec();
3722 mutex_enter(&ds->ds_lock);
3723 if (ds->ds_phys->ds_userrefs_obj == 0) {
3725 * This is the first user hold for this dataset. Create
3726 * the userrefs zap object.
3728 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3729 zapobj = ds->ds_phys->ds_userrefs_obj =
3730 zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx);
3732 zapobj = ds->ds_phys->ds_userrefs_obj;
3735 mutex_exit(&ds->ds_lock);
3737 VERIFY(0 == zap_add(mos, zapobj, htag, 8, 1, &now, tx));
3740 VERIFY(0 == dsl_pool_user_hold(dp, ds->ds_object,
3744 spa_history_log_internal(LOG_DS_USER_HOLD,
3745 dp->dp_spa, tx, "<%s> temp = %d dataset = %llu", htag,
3746 (int)ha->temphold, ds->ds_object);
3750 dsl_dataset_user_hold_one(const char *dsname, void *arg)
3752 struct dsl_ds_holdarg *ha = arg;
3757 /* alloc a buffer to hold dsname@snapname plus terminating NULL */
3758 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3759 error = dsl_dataset_hold(name, ha->dstg, &ds);
3762 ha->gotone = B_TRUE;
3763 dsl_sync_task_create(ha->dstg, dsl_dataset_user_hold_check,
3764 dsl_dataset_user_hold_sync, ds, ha, 0);
3765 } else if (error == ENOENT && ha->recursive) {
3768 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3774 dsl_dataset_user_hold_for_send(dsl_dataset_t *ds, char *htag,
3777 struct dsl_ds_holdarg *ha;
3780 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3782 ha->temphold = temphold;
3783 error = dsl_sync_task_do(ds->ds_dir->dd_pool,
3784 dsl_dataset_user_hold_check, dsl_dataset_user_hold_sync,
3786 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3792 dsl_dataset_user_hold(char *dsname, char *snapname, char *htag,
3793 boolean_t recursive, boolean_t temphold, int cleanup_fd)
3795 struct dsl_ds_holdarg *ha;
3796 dsl_sync_task_t *dst;
3801 if (cleanup_fd != -1) {
3802 /* Currently we only support cleanup-on-exit of tempholds. */
3805 error = zfs_onexit_fd_hold(cleanup_fd, &minor);
3810 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3812 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3814 error = spa_open(dsname, &spa, FTAG);
3816 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3817 if (cleanup_fd != -1)
3818 zfs_onexit_fd_rele(cleanup_fd);
3822 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
3824 ha->snapname = snapname;
3825 ha->recursive = recursive;
3826 ha->temphold = temphold;
3829 error = dmu_objset_find(dsname, dsl_dataset_user_hold_one,
3830 ha, DS_FIND_CHILDREN);
3832 error = dsl_dataset_user_hold_one(dsname, ha);
3835 error = dsl_sync_task_group_wait(ha->dstg);
3837 for (dst = list_head(&ha->dstg->dstg_tasks); dst;
3838 dst = list_next(&ha->dstg->dstg_tasks, dst)) {
3839 dsl_dataset_t *ds = dst->dst_arg1;
3842 dsl_dataset_name(ds, ha->failed);
3843 *strchr(ha->failed, '@') = '\0';
3844 } else if (error == 0 && minor != 0 && temphold) {
3846 * If this hold is to be released upon process exit,
3847 * register that action now.
3849 dsl_register_onexit_hold_cleanup(ds, htag, minor);
3851 dsl_dataset_rele(ds, ha->dstg);
3854 if (error == 0 && recursive && !ha->gotone)
3858 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed));
3860 dsl_sync_task_group_destroy(ha->dstg);
3862 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3863 spa_close(spa, FTAG);
3864 if (cleanup_fd != -1)
3865 zfs_onexit_fd_rele(cleanup_fd);
3869 struct dsl_ds_releasearg {
3872 boolean_t own; /* do we own or just hold ds? */
3876 dsl_dataset_release_might_destroy(dsl_dataset_t *ds, const char *htag,
3877 boolean_t *might_destroy)
3879 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3884 *might_destroy = B_FALSE;
3886 mutex_enter(&ds->ds_lock);
3887 zapobj = ds->ds_phys->ds_userrefs_obj;
3889 /* The tag can't possibly exist */
3890 mutex_exit(&ds->ds_lock);
3894 /* Make sure the tag exists */
3895 error = zap_lookup(mos, zapobj, htag, 8, 1, &tmp);
3897 mutex_exit(&ds->ds_lock);
3898 if (error == ENOENT)
3903 if (ds->ds_userrefs == 1 && ds->ds_phys->ds_num_children == 1 &&
3904 DS_IS_DEFER_DESTROY(ds))
3905 *might_destroy = B_TRUE;
3907 mutex_exit(&ds->ds_lock);
3912 dsl_dataset_user_release_check(void *arg1, void *tag, dmu_tx_t *tx)
3914 struct dsl_ds_releasearg *ra = arg1;
3915 dsl_dataset_t *ds = ra->ds;
3916 boolean_t might_destroy;
3919 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS)
3922 error = dsl_dataset_release_might_destroy(ds, ra->htag, &might_destroy);
3926 if (might_destroy) {
3927 struct dsl_ds_destroyarg dsda = {0};
3929 if (dmu_tx_is_syncing(tx)) {
3931 * If we're not prepared to remove the snapshot,
3932 * we can't allow the release to happen right now.
3938 dsda.releasing = B_TRUE;
3939 return (dsl_dataset_destroy_check(&dsda, tag, tx));
3946 dsl_dataset_user_release_sync(void *arg1, void *tag, dmu_tx_t *tx)
3948 struct dsl_ds_releasearg *ra = arg1;
3949 dsl_dataset_t *ds = ra->ds;
3950 dsl_pool_t *dp = ds->ds_dir->dd_pool;
3951 objset_t *mos = dp->dp_meta_objset;
3953 uint64_t dsobj = ds->ds_object;
3957 mutex_enter(&ds->ds_lock);
3959 refs = ds->ds_userrefs;
3960 mutex_exit(&ds->ds_lock);
3961 error = dsl_pool_user_release(dp, ds->ds_object, ra->htag, tx);
3962 VERIFY(error == 0 || error == ENOENT);
3963 zapobj = ds->ds_phys->ds_userrefs_obj;
3964 VERIFY(0 == zap_remove(mos, zapobj, ra->htag, tx));
3966 spa_history_log_internal(LOG_DS_USER_RELEASE,
3967 dp->dp_spa, tx, "<%s> %lld dataset = %llu",
3968 ra->htag, (longlong_t)refs, dsobj);
3970 if (ds->ds_userrefs == 0 && ds->ds_phys->ds_num_children == 1 &&
3971 DS_IS_DEFER_DESTROY(ds)) {
3972 struct dsl_ds_destroyarg dsda = {0};
3976 dsda.releasing = B_TRUE;
3977 /* We already did the destroy_check */
3978 dsl_dataset_destroy_sync(&dsda, tag, tx);
3983 dsl_dataset_user_release_one(const char *dsname, void *arg)
3985 struct dsl_ds_holdarg *ha = arg;
3986 struct dsl_ds_releasearg *ra;
3989 void *dtag = ha->dstg;
3991 boolean_t own = B_FALSE;
3992 boolean_t might_destroy;
3994 /* alloc a buffer to hold dsname@snapname, plus the terminating NULL */
3995 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3996 error = dsl_dataset_hold(name, dtag, &ds);
3998 if (error == ENOENT && ha->recursive)
4000 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
4004 ha->gotone = B_TRUE;
4006 ASSERT(dsl_dataset_is_snapshot(ds));
4008 error = dsl_dataset_release_might_destroy(ds, ha->htag, &might_destroy);
4010 dsl_dataset_rele(ds, dtag);
4014 if (might_destroy) {
4016 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
4017 error = zfs_unmount_snap(name, NULL);
4020 dsl_dataset_rele(ds, dtag);
4024 if (!dsl_dataset_tryown(ds, B_TRUE, dtag)) {
4025 dsl_dataset_rele(ds, dtag);
4029 dsl_dataset_make_exclusive(ds, dtag);
4033 ra = kmem_alloc(sizeof (struct dsl_ds_releasearg), KM_SLEEP);
4035 ra->htag = ha->htag;
4037 dsl_sync_task_create(ha->dstg, dsl_dataset_user_release_check,
4038 dsl_dataset_user_release_sync, ra, dtag, 0);
4044 dsl_dataset_user_release(char *dsname, char *snapname, char *htag,
4045 boolean_t recursive)
4047 struct dsl_ds_holdarg *ha;
4048 dsl_sync_task_t *dst;
4053 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
4055 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
4057 error = spa_open(dsname, &spa, FTAG);
4059 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
4063 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
4065 ha->snapname = snapname;
4066 ha->recursive = recursive;
4068 error = dmu_objset_find(dsname, dsl_dataset_user_release_one,
4069 ha, DS_FIND_CHILDREN);
4071 error = dsl_dataset_user_release_one(dsname, ha);
4074 error = dsl_sync_task_group_wait(ha->dstg);
4076 for (dst = list_head(&ha->dstg->dstg_tasks); dst;
4077 dst = list_next(&ha->dstg->dstg_tasks, dst)) {
4078 struct dsl_ds_releasearg *ra = dst->dst_arg1;
4079 dsl_dataset_t *ds = ra->ds;
4082 dsl_dataset_name(ds, ha->failed);
4085 dsl_dataset_disown(ds, ha->dstg);
4087 dsl_dataset_rele(ds, ha->dstg);
4089 kmem_free(ra, sizeof (struct dsl_ds_releasearg));
4092 if (error == 0 && recursive && !ha->gotone)
4095 if (error && error != EBUSY)
4096 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed));
4098 dsl_sync_task_group_destroy(ha->dstg);
4099 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
4100 spa_close(spa, FTAG);
4103 * We can get EBUSY if we were racing with deferred destroy and
4104 * dsl_dataset_user_release_check() hadn't done the necessary
4105 * open context setup. We can also get EBUSY if we're racing
4106 * with destroy and that thread is the ds_owner. Either way
4107 * the busy condition should be transient, and we should retry
4108 * the release operation.
4117 * Called at spa_load time (with retry == B_FALSE) to release a stale
4118 * temporary user hold. Also called by the onexit code (with retry == B_TRUE).
4121 dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, char *htag,
4131 rw_enter(&dp->dp_config_rwlock, RW_READER);
4132 error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds);
4133 rw_exit(&dp->dp_config_rwlock);
4136 namelen = dsl_dataset_namelen(ds)+1;
4137 name = kmem_alloc(namelen, KM_SLEEP);
4138 dsl_dataset_name(ds, name);
4139 dsl_dataset_rele(ds, FTAG);
4141 snap = strchr(name, '@');
4144 error = dsl_dataset_user_release(name, snap, htag, B_FALSE);
4145 kmem_free(name, namelen);
4148 * The object can't have been destroyed because we have a hold,
4149 * but it might have been renamed, resulting in ENOENT. Retry
4150 * if we've been requested to do so.
4152 * It would be nice if we could use the dsobj all the way
4153 * through and avoid ENOENT entirely. But we might need to
4154 * unmount the snapshot, and there's currently no way to lookup
4155 * a vfsp using a ZFS object id.
4157 } while ((error == ENOENT) && retry);
4163 dsl_dataset_get_holds(const char *dsname, nvlist_t **nvp)
4168 err = dsl_dataset_hold(dsname, FTAG, &ds);
4172 VERIFY(0 == nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP));
4173 if (ds->ds_phys->ds_userrefs_obj != 0) {
4174 zap_attribute_t *za;
4177 za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP);
4178 for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset,
4179 ds->ds_phys->ds_userrefs_obj);
4180 zap_cursor_retrieve(&zc, za) == 0;
4181 zap_cursor_advance(&zc)) {
4182 VERIFY(0 == nvlist_add_uint64(*nvp, za->za_name,
4183 za->za_first_integer));
4185 zap_cursor_fini(&zc);
4186 kmem_free(za, sizeof (zap_attribute_t));
4188 dsl_dataset_rele(ds, FTAG);
4193 * Note, this function is used as the callback for dmu_objset_find(). We
4194 * always return 0 so that we will continue to find and process
4195 * inconsistent datasets, even if we encounter an error trying to
4196 * process one of them.
4200 dsl_destroy_inconsistent(const char *dsname, void *arg)
4204 if (dsl_dataset_own(dsname, B_TRUE, FTAG, &ds) == 0) {
4205 if (DS_IS_INCONSISTENT(ds))
4206 (void) dsl_dataset_destroy(ds, FTAG, B_FALSE);
4208 dsl_dataset_disown(ds, FTAG);
4214 * Return (in *usedp) the amount of space written in new that is not
4215 * present in oldsnap. New may be a snapshot or the head. Old must be
4216 * a snapshot before new, in new's filesystem (or its origin). If not then
4217 * fail and return EINVAL.
4219 * The written space is calculated by considering two components: First, we
4220 * ignore any freed space, and calculate the written as new's used space
4221 * minus old's used space. Next, we add in the amount of space that was freed
4222 * between the two snapshots, thus reducing new's used space relative to old's.
4223 * Specifically, this is the space that was born before old->ds_creation_txg,
4224 * and freed before new (ie. on new's deadlist or a previous deadlist).
4226 * space freed [---------------------]
4227 * snapshots ---O-------O--------O-------O------
4231 dsl_dataset_space_written(dsl_dataset_t *oldsnap, dsl_dataset_t *new,
4232 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
4236 dsl_pool_t *dp = new->ds_dir->dd_pool;
4239 *usedp += new->ds_phys->ds_referenced_bytes;
4240 *usedp -= oldsnap->ds_phys->ds_referenced_bytes;
4243 *compp += new->ds_phys->ds_compressed_bytes;
4244 *compp -= oldsnap->ds_phys->ds_compressed_bytes;
4247 *uncompp += new->ds_phys->ds_uncompressed_bytes;
4248 *uncompp -= oldsnap->ds_phys->ds_uncompressed_bytes;
4250 rw_enter(&dp->dp_config_rwlock, RW_READER);
4251 snapobj = new->ds_object;
4252 while (snapobj != oldsnap->ds_object) {
4253 dsl_dataset_t *snap;
4254 uint64_t used, comp, uncomp;
4256 if (snapobj == new->ds_object) {
4259 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &snap);
4264 if (snap->ds_phys->ds_prev_snap_txg ==
4265 oldsnap->ds_phys->ds_creation_txg) {
4267 * The blocks in the deadlist can not be born after
4268 * ds_prev_snap_txg, so get the whole deadlist space,
4269 * which is more efficient (especially for old-format
4270 * deadlists). Unfortunately the deadlist code
4271 * doesn't have enough information to make this
4272 * optimization itself.
4274 dsl_deadlist_space(&snap->ds_deadlist,
4275 &used, &comp, &uncomp);
4277 dsl_deadlist_space_range(&snap->ds_deadlist,
4278 0, oldsnap->ds_phys->ds_creation_txg,
4279 &used, &comp, &uncomp);
4286 * If we get to the beginning of the chain of snapshots
4287 * (ds_prev_snap_obj == 0) before oldsnap, then oldsnap
4288 * was not a snapshot of/before new.
4290 snapobj = snap->ds_phys->ds_prev_snap_obj;
4292 dsl_dataset_rele(snap, FTAG);
4299 rw_exit(&dp->dp_config_rwlock);
4304 * Return (in *usedp) the amount of space that will be reclaimed if firstsnap,
4305 * lastsnap, and all snapshots in between are deleted.
4307 * blocks that would be freed [---------------------------]
4308 * snapshots ---O-------O--------O-------O--------O
4309 * firstsnap lastsnap
4311 * This is the set of blocks that were born after the snap before firstsnap,
4312 * (birth > firstsnap->prev_snap_txg) and died before the snap after the
4313 * last snap (ie, is on lastsnap->ds_next->ds_deadlist or an earlier deadlist).
4314 * We calculate this by iterating over the relevant deadlists (from the snap
4315 * after lastsnap, backward to the snap after firstsnap), summing up the
4316 * space on the deadlist that was born after the snap before firstsnap.
4319 dsl_dataset_space_wouldfree(dsl_dataset_t *firstsnap,
4320 dsl_dataset_t *lastsnap,
4321 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
4325 dsl_pool_t *dp = firstsnap->ds_dir->dd_pool;
4327 ASSERT(dsl_dataset_is_snapshot(firstsnap));
4328 ASSERT(dsl_dataset_is_snapshot(lastsnap));
4331 * Check that the snapshots are in the same dsl_dir, and firstsnap
4332 * is before lastsnap.
4334 if (firstsnap->ds_dir != lastsnap->ds_dir ||
4335 firstsnap->ds_phys->ds_creation_txg >
4336 lastsnap->ds_phys->ds_creation_txg)
4339 *usedp = *compp = *uncompp = 0;
4341 rw_enter(&dp->dp_config_rwlock, RW_READER);
4342 snapobj = lastsnap->ds_phys->ds_next_snap_obj;
4343 while (snapobj != firstsnap->ds_object) {
4345 uint64_t used, comp, uncomp;
4347 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &ds);
4351 dsl_deadlist_space_range(&ds->ds_deadlist,
4352 firstsnap->ds_phys->ds_prev_snap_txg, UINT64_MAX,
4353 &used, &comp, &uncomp);
4358 snapobj = ds->ds_phys->ds_prev_snap_obj;
4359 ASSERT3U(snapobj, !=, 0);
4360 dsl_dataset_rele(ds, FTAG);
4362 rw_exit(&dp->dp_config_rwlock);