4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2011 by Delphix. All rights reserved.
26 #include <sys/dmu_objset.h>
27 #include <sys/dsl_dataset.h>
28 #include <sys/dsl_dir.h>
29 #include <sys/dsl_prop.h>
30 #include <sys/dsl_synctask.h>
31 #include <sys/dmu_traverse.h>
32 #include <sys/dmu_tx.h>
36 #include <sys/unique.h>
37 #include <sys/zfs_context.h>
38 #include <sys/zfs_ioctl.h>
40 #include <sys/zfs_znode.h>
41 #include <sys/zfs_onexit.h>
43 #include <sys/dsl_scan.h>
44 #include <sys/dsl_deadlist.h>
46 static char *dsl_reaper = "the grim reaper";
48 static dsl_checkfunc_t dsl_dataset_destroy_begin_check;
49 static dsl_syncfunc_t dsl_dataset_destroy_begin_sync;
50 static dsl_syncfunc_t dsl_dataset_set_reservation_sync;
52 #define SWITCH64(x, y) \
54 uint64_t __tmp = (x); \
59 #define DS_REF_MAX (1ULL << 62)
61 #define DSL_DEADLIST_BLOCKSIZE SPA_MAXBLOCKSIZE
63 #define DSL_DATASET_IS_DESTROYED(ds) ((ds)->ds_owner == dsl_reaper)
67 * Figure out how much of this delta should be propogated to the dsl_dir
68 * layer. If there's a refreservation, that space has already been
69 * partially accounted for in our ancestors.
72 parent_delta(dsl_dataset_t *ds, int64_t delta)
74 uint64_t old_bytes, new_bytes;
76 if (ds->ds_reserved == 0)
79 old_bytes = MAX(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
80 new_bytes = MAX(ds->ds_phys->ds_unique_bytes + delta, ds->ds_reserved);
82 ASSERT3U(ABS((int64_t)(new_bytes - old_bytes)), <=, ABS(delta));
83 return (new_bytes - old_bytes);
87 dsl_dataset_block_born(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx)
89 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
90 int compressed = BP_GET_PSIZE(bp);
91 int uncompressed = BP_GET_UCSIZE(bp);
94 dprintf_bp(bp, "ds=%p", ds);
96 ASSERT(dmu_tx_is_syncing(tx));
97 /* It could have been compressed away to nothing */
100 ASSERT(BP_GET_TYPE(bp) != DMU_OT_NONE);
101 ASSERT3U(BP_GET_TYPE(bp), <, DMU_OT_NUMTYPES);
104 * Account for the meta-objset space in its placeholder
107 ASSERT3U(compressed, ==, uncompressed); /* it's all metadata */
108 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD,
109 used, compressed, uncompressed, tx);
110 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx);
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_used_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);
147 * Account for the meta-objset space in its placeholder
150 dsl_free(tx->tx_pool, tx->tx_txg, bp);
152 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD,
153 -used, -compressed, -uncompressed, tx);
154 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx);
157 ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool);
159 ASSERT(!dsl_dataset_is_snapshot(ds));
160 dmu_buf_will_dirty(ds->ds_dbuf, tx);
162 if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) {
165 dprintf_bp(bp, "freeing ds=%llu", ds->ds_object);
166 dsl_free(tx->tx_pool, tx->tx_txg, bp);
168 mutex_enter(&ds->ds_dir->dd_lock);
169 mutex_enter(&ds->ds_lock);
170 ASSERT(ds->ds_phys->ds_unique_bytes >= used ||
171 !DS_UNIQUE_IS_ACCURATE(ds));
172 delta = parent_delta(ds, -used);
173 ds->ds_phys->ds_unique_bytes -= used;
174 mutex_exit(&ds->ds_lock);
175 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
176 delta, -compressed, -uncompressed, tx);
177 dsl_dir_transfer_space(ds->ds_dir, -used - delta,
178 DD_USED_REFRSRV, DD_USED_HEAD, tx);
179 mutex_exit(&ds->ds_dir->dd_lock);
181 dprintf_bp(bp, "putting on dead list: %s", "");
184 * We are here as part of zio's write done callback,
185 * which means we're a zio interrupt thread. We can't
186 * call dsl_deadlist_insert() now because it may block
187 * waiting for I/O. Instead, put bp on the deferred
188 * queue and let dsl_pool_sync() finish the job.
190 bplist_append(&ds->ds_pending_deadlist, bp);
192 dsl_deadlist_insert(&ds->ds_deadlist, bp, tx);
194 ASSERT3U(ds->ds_prev->ds_object, ==,
195 ds->ds_phys->ds_prev_snap_obj);
196 ASSERT(ds->ds_prev->ds_phys->ds_num_children > 0);
197 /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */
198 if (ds->ds_prev->ds_phys->ds_next_snap_obj ==
199 ds->ds_object && bp->blk_birth >
200 ds->ds_prev->ds_phys->ds_prev_snap_txg) {
201 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
202 mutex_enter(&ds->ds_prev->ds_lock);
203 ds->ds_prev->ds_phys->ds_unique_bytes += used;
204 mutex_exit(&ds->ds_prev->ds_lock);
206 if (bp->blk_birth > ds->ds_dir->dd_origin_txg) {
207 dsl_dir_transfer_space(ds->ds_dir, used,
208 DD_USED_HEAD, DD_USED_SNAP, tx);
211 mutex_enter(&ds->ds_lock);
212 ASSERT3U(ds->ds_phys->ds_used_bytes, >=, used);
213 ds->ds_phys->ds_used_bytes -= used;
214 ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed);
215 ds->ds_phys->ds_compressed_bytes -= compressed;
216 ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed);
217 ds->ds_phys->ds_uncompressed_bytes -= uncompressed;
218 mutex_exit(&ds->ds_lock);
224 dsl_dataset_prev_snap_txg(dsl_dataset_t *ds)
226 uint64_t trysnap = 0;
231 * The snapshot creation could fail, but that would cause an
232 * incorrect FALSE return, which would only result in an
233 * overestimation of the amount of space that an operation would
234 * consume, which is OK.
236 * There's also a small window where we could miss a pending
237 * snapshot, because we could set the sync task in the quiescing
238 * phase. So this should only be used as a guess.
240 if (ds->ds_trysnap_txg >
241 spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa))
242 trysnap = ds->ds_trysnap_txg;
243 return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap));
247 dsl_dataset_block_freeable(dsl_dataset_t *ds, const blkptr_t *bp,
250 if (blk_birth <= dsl_dataset_prev_snap_txg(ds))
253 ddt_prefetch(dsl_dataset_get_spa(ds), bp);
260 dsl_dataset_evict(dmu_buf_t *db, void *dsv)
262 dsl_dataset_t *ds = dsv;
264 ASSERT(ds->ds_owner == NULL || DSL_DATASET_IS_DESTROYED(ds));
266 unique_remove(ds->ds_fsid_guid);
268 if (ds->ds_objset != NULL)
269 dmu_objset_evict(ds->ds_objset);
272 dsl_dataset_drop_ref(ds->ds_prev, ds);
276 bplist_destroy(&ds->ds_pending_deadlist);
278 dsl_deadlist_close(&ds->ds_deadlist);
280 ASSERT(ds->ds_deadlist.dl_dbuf == NULL);
281 ASSERT(!ds->ds_deadlist.dl_oldfmt);
284 dsl_dir_close(ds->ds_dir, ds);
286 ASSERT(!list_link_active(&ds->ds_synced_link));
288 if (mutex_owned(&ds->ds_lock))
289 mutex_exit(&ds->ds_lock);
290 mutex_destroy(&ds->ds_lock);
291 mutex_destroy(&ds->ds_recvlock);
292 if (mutex_owned(&ds->ds_opening_lock))
293 mutex_exit(&ds->ds_opening_lock);
294 mutex_destroy(&ds->ds_opening_lock);
295 rw_destroy(&ds->ds_rwlock);
296 cv_destroy(&ds->ds_exclusive_cv);
298 kmem_free(ds, sizeof (dsl_dataset_t));
302 dsl_dataset_get_snapname(dsl_dataset_t *ds)
304 dsl_dataset_phys_t *headphys;
307 dsl_pool_t *dp = ds->ds_dir->dd_pool;
308 objset_t *mos = dp->dp_meta_objset;
310 if (ds->ds_snapname[0])
312 if (ds->ds_phys->ds_next_snap_obj == 0)
315 err = dmu_bonus_hold(mos, ds->ds_dir->dd_phys->dd_head_dataset_obj,
319 headphys = headdbuf->db_data;
320 err = zap_value_search(dp->dp_meta_objset,
321 headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname);
322 dmu_buf_rele(headdbuf, FTAG);
327 dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name, uint64_t *value)
329 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
330 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
334 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
339 err = zap_lookup_norm(mos, snapobj, name, 8, 1,
340 value, mt, NULL, 0, NULL);
341 if (err == ENOTSUP && mt == MT_FIRST)
342 err = zap_lookup(mos, snapobj, name, 8, 1, value);
347 dsl_dataset_snap_remove(dsl_dataset_t *ds, char *name, dmu_tx_t *tx)
349 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
350 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
354 dsl_dir_snap_cmtime_update(ds->ds_dir);
356 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
361 err = zap_remove_norm(mos, snapobj, name, mt, tx);
362 if (err == ENOTSUP && mt == MT_FIRST)
363 err = zap_remove(mos, snapobj, name, tx);
368 dsl_dataset_get_ref(dsl_pool_t *dp, uint64_t dsobj, void *tag,
371 objset_t *mos = dp->dp_meta_objset;
375 dmu_object_info_t doi;
377 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) ||
378 dsl_pool_sync_context(dp));
380 err = dmu_bonus_hold(mos, dsobj, tag, &dbuf);
384 /* Make sure dsobj has the correct object type. */
385 dmu_object_info_from_db(dbuf, &doi);
386 if (doi.doi_type != DMU_OT_DSL_DATASET)
389 ds = dmu_buf_get_user(dbuf);
391 dsl_dataset_t *winner;
393 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP);
395 ds->ds_object = dsobj;
396 ds->ds_phys = dbuf->db_data;
398 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL);
399 mutex_init(&ds->ds_recvlock, NULL, MUTEX_DEFAULT, NULL);
400 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL);
401 rw_init(&ds->ds_rwlock, 0, 0, 0);
402 cv_init(&ds->ds_exclusive_cv, NULL, CV_DEFAULT, NULL);
404 bplist_create(&ds->ds_pending_deadlist);
405 dsl_deadlist_open(&ds->ds_deadlist,
406 mos, ds->ds_phys->ds_deadlist_obj);
409 err = dsl_dir_open_obj(dp,
410 ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir);
413 mutex_destroy(&ds->ds_lock);
414 mutex_destroy(&ds->ds_recvlock);
415 mutex_destroy(&ds->ds_opening_lock);
416 rw_destroy(&ds->ds_rwlock);
417 cv_destroy(&ds->ds_exclusive_cv);
418 bplist_destroy(&ds->ds_pending_deadlist);
419 dsl_deadlist_close(&ds->ds_deadlist);
420 kmem_free(ds, sizeof (dsl_dataset_t));
421 dmu_buf_rele(dbuf, tag);
425 if (!dsl_dataset_is_snapshot(ds)) {
426 ds->ds_snapname[0] = '\0';
427 if (ds->ds_phys->ds_prev_snap_obj) {
428 err = dsl_dataset_get_ref(dp,
429 ds->ds_phys->ds_prev_snap_obj,
433 if (zfs_flags & ZFS_DEBUG_SNAPNAMES)
434 err = dsl_dataset_get_snapname(ds);
435 if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) {
437 ds->ds_dir->dd_pool->dp_meta_objset,
438 ds->ds_phys->ds_userrefs_obj,
443 if (err == 0 && !dsl_dataset_is_snapshot(ds)) {
445 * In sync context, we're called with either no lock
446 * or with the write lock. If we're not syncing,
447 * we're always called with the read lock held.
449 boolean_t need_lock =
450 !RW_WRITE_HELD(&dp->dp_config_rwlock) &&
451 dsl_pool_sync_context(dp);
454 rw_enter(&dp->dp_config_rwlock, RW_READER);
456 err = dsl_prop_get_ds(ds,
457 "refreservation", sizeof (uint64_t), 1,
458 &ds->ds_reserved, NULL);
460 err = dsl_prop_get_ds(ds,
461 "refquota", sizeof (uint64_t), 1,
462 &ds->ds_quota, NULL);
466 rw_exit(&dp->dp_config_rwlock);
468 ds->ds_reserved = ds->ds_quota = 0;
472 winner = dmu_buf_set_user_ie(dbuf, ds, &ds->ds_phys,
476 bplist_destroy(&ds->ds_pending_deadlist);
477 dsl_deadlist_close(&ds->ds_deadlist);
479 dsl_dataset_drop_ref(ds->ds_prev, ds);
480 dsl_dir_close(ds->ds_dir, ds);
481 mutex_destroy(&ds->ds_lock);
482 mutex_destroy(&ds->ds_recvlock);
483 mutex_destroy(&ds->ds_opening_lock);
484 rw_destroy(&ds->ds_rwlock);
485 cv_destroy(&ds->ds_exclusive_cv);
486 kmem_free(ds, sizeof (dsl_dataset_t));
488 dmu_buf_rele(dbuf, tag);
494 unique_insert(ds->ds_phys->ds_fsid_guid);
497 ASSERT3P(ds->ds_dbuf, ==, dbuf);
498 ASSERT3P(ds->ds_phys, ==, dbuf->db_data);
499 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 ||
500 spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN ||
501 dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap);
502 mutex_enter(&ds->ds_lock);
503 if (!dsl_pool_sync_context(dp) && DSL_DATASET_IS_DESTROYED(ds)) {
504 mutex_exit(&ds->ds_lock);
505 dmu_buf_rele(ds->ds_dbuf, tag);
508 mutex_exit(&ds->ds_lock);
514 dsl_dataset_hold_ref(dsl_dataset_t *ds, void *tag)
516 dsl_pool_t *dp = ds->ds_dir->dd_pool;
519 * In syncing context we don't want the rwlock lock: there
520 * may be an existing writer waiting for sync phase to
521 * finish. We don't need to worry about such writers, since
522 * sync phase is single-threaded, so the writer can't be
523 * doing anything while we are active.
525 if (dsl_pool_sync_context(dp)) {
526 ASSERT(!DSL_DATASET_IS_DESTROYED(ds));
531 * Normal users will hold the ds_rwlock as a READER until they
532 * are finished (i.e., call dsl_dataset_rele()). "Owners" will
533 * drop their READER lock after they set the ds_owner field.
535 * If the dataset is being destroyed, the destroy thread will
536 * obtain a WRITER lock for exclusive access after it's done its
537 * open-context work and then change the ds_owner to
538 * dsl_reaper once destruction is assured. So threads
539 * may block here temporarily, until the "destructability" of
540 * the dataset is determined.
542 ASSERT(!RW_WRITE_HELD(&dp->dp_config_rwlock));
543 mutex_enter(&ds->ds_lock);
544 while (!rw_tryenter(&ds->ds_rwlock, RW_READER)) {
545 rw_exit(&dp->dp_config_rwlock);
546 cv_wait(&ds->ds_exclusive_cv, &ds->ds_lock);
547 if (DSL_DATASET_IS_DESTROYED(ds)) {
548 mutex_exit(&ds->ds_lock);
549 dsl_dataset_drop_ref(ds, tag);
550 rw_enter(&dp->dp_config_rwlock, RW_READER);
554 * The dp_config_rwlock lives above the ds_lock. And
555 * we need to check DSL_DATASET_IS_DESTROYED() while
556 * holding the ds_lock, so we have to drop and reacquire
559 mutex_exit(&ds->ds_lock);
560 rw_enter(&dp->dp_config_rwlock, RW_READER);
561 mutex_enter(&ds->ds_lock);
563 mutex_exit(&ds->ds_lock);
568 dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag,
571 int err = dsl_dataset_get_ref(dp, dsobj, tag, dsp);
575 return (dsl_dataset_hold_ref(*dsp, tag));
579 dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj, boolean_t inconsistentok,
580 void *tag, dsl_dataset_t **dsp)
582 int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp);
585 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) {
586 dsl_dataset_rele(*dsp, tag);
594 dsl_dataset_hold(const char *name, void *tag, dsl_dataset_t **dsp)
598 const char *snapname;
602 err = dsl_dir_open_spa(NULL, name, FTAG, &dd, &snapname);
607 obj = dd->dd_phys->dd_head_dataset_obj;
608 rw_enter(&dp->dp_config_rwlock, RW_READER);
610 err = dsl_dataset_get_ref(dp, obj, tag, dsp);
616 err = dsl_dataset_hold_ref(*dsp, tag);
618 /* we may be looking for a snapshot */
619 if (err == 0 && snapname != NULL) {
620 dsl_dataset_t *ds = NULL;
622 if (*snapname++ != '@') {
623 dsl_dataset_rele(*dsp, tag);
628 dprintf("looking for snapshot '%s'\n", snapname);
629 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj);
631 err = dsl_dataset_get_ref(dp, obj, tag, &ds);
632 dsl_dataset_rele(*dsp, tag);
634 ASSERT3U((err == 0), ==, (ds != NULL));
637 mutex_enter(&ds->ds_lock);
638 if (ds->ds_snapname[0] == 0)
639 (void) strlcpy(ds->ds_snapname, snapname,
640 sizeof (ds->ds_snapname));
641 mutex_exit(&ds->ds_lock);
642 err = dsl_dataset_hold_ref(ds, tag);
643 *dsp = err ? NULL : ds;
647 rw_exit(&dp->dp_config_rwlock);
648 dsl_dir_close(dd, FTAG);
653 dsl_dataset_own(const char *name, boolean_t inconsistentok,
654 void *tag, dsl_dataset_t **dsp)
656 int err = dsl_dataset_hold(name, tag, dsp);
659 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) {
660 dsl_dataset_rele(*dsp, tag);
667 dsl_dataset_name(dsl_dataset_t *ds, char *name)
670 (void) strcpy(name, "mos");
672 dsl_dir_name(ds->ds_dir, name);
673 VERIFY(0 == dsl_dataset_get_snapname(ds));
674 if (ds->ds_snapname[0]) {
675 (void) strcat(name, "@");
677 * We use a "recursive" mutex so that we
678 * can call dprintf_ds() with ds_lock held.
680 if (!MUTEX_HELD(&ds->ds_lock)) {
681 mutex_enter(&ds->ds_lock);
682 (void) strcat(name, ds->ds_snapname);
683 mutex_exit(&ds->ds_lock);
685 (void) strcat(name, ds->ds_snapname);
692 dsl_dataset_namelen(dsl_dataset_t *ds)
697 result = 3; /* "mos" */
699 result = dsl_dir_namelen(ds->ds_dir);
700 VERIFY(0 == dsl_dataset_get_snapname(ds));
701 if (ds->ds_snapname[0]) {
702 ++result; /* adding one for the @-sign */
703 if (!MUTEX_HELD(&ds->ds_lock)) {
704 mutex_enter(&ds->ds_lock);
705 result += strlen(ds->ds_snapname);
706 mutex_exit(&ds->ds_lock);
708 result += strlen(ds->ds_snapname);
717 dsl_dataset_drop_ref(dsl_dataset_t *ds, void *tag)
719 dmu_buf_rele(ds->ds_dbuf, tag);
723 dsl_dataset_rele(dsl_dataset_t *ds, void *tag)
725 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) {
726 rw_exit(&ds->ds_rwlock);
728 dsl_dataset_drop_ref(ds, tag);
732 dsl_dataset_disown(dsl_dataset_t *ds, void *tag)
734 ASSERT((ds->ds_owner == tag && ds->ds_dbuf) ||
735 (DSL_DATASET_IS_DESTROYED(ds) && ds->ds_dbuf == NULL));
737 mutex_enter(&ds->ds_lock);
739 if (RW_WRITE_HELD(&ds->ds_rwlock)) {
740 rw_exit(&ds->ds_rwlock);
741 cv_broadcast(&ds->ds_exclusive_cv);
743 mutex_exit(&ds->ds_lock);
745 dsl_dataset_drop_ref(ds, tag);
747 dsl_dataset_evict(NULL, ds);
751 dsl_dataset_tryown(dsl_dataset_t *ds, boolean_t inconsistentok, void *tag)
753 boolean_t gotit = FALSE;
755 mutex_enter(&ds->ds_lock);
756 if (ds->ds_owner == NULL &&
757 (!DS_IS_INCONSISTENT(ds) || inconsistentok)) {
759 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool))
760 rw_exit(&ds->ds_rwlock);
763 mutex_exit(&ds->ds_lock);
768 dsl_dataset_make_exclusive(dsl_dataset_t *ds, void *owner)
770 ASSERT3P(owner, ==, ds->ds_owner);
771 if (!RW_WRITE_HELD(&ds->ds_rwlock))
772 rw_enter(&ds->ds_rwlock, RW_WRITER);
776 dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin,
777 uint64_t flags, dmu_tx_t *tx)
779 dsl_pool_t *dp = dd->dd_pool;
781 dsl_dataset_phys_t *dsphys;
783 objset_t *mos = dp->dp_meta_objset;
786 origin = dp->dp_origin_snap;
788 ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp);
789 ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0);
790 ASSERT(dmu_tx_is_syncing(tx));
791 ASSERT(dd->dd_phys->dd_head_dataset_obj == 0);
793 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
794 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
795 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
796 dmu_buf_will_dirty(dbuf, tx);
797 dsphys = dbuf->db_data;
798 bzero(dsphys, sizeof (dsl_dataset_phys_t));
799 dsphys->ds_dir_obj = dd->dd_object;
800 dsphys->ds_flags = flags;
801 dsphys->ds_fsid_guid = unique_create();
802 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
803 sizeof (dsphys->ds_guid));
804 dsphys->ds_snapnames_zapobj =
805 zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP,
807 dsphys->ds_creation_time = gethrestime_sec();
808 dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg;
810 if (origin == NULL) {
811 dsphys->ds_deadlist_obj = dsl_deadlist_alloc(mos, tx);
815 dsphys->ds_prev_snap_obj = origin->ds_object;
816 dsphys->ds_prev_snap_txg =
817 origin->ds_phys->ds_creation_txg;
818 dsphys->ds_used_bytes =
819 origin->ds_phys->ds_used_bytes;
820 dsphys->ds_compressed_bytes =
821 origin->ds_phys->ds_compressed_bytes;
822 dsphys->ds_uncompressed_bytes =
823 origin->ds_phys->ds_uncompressed_bytes;
824 dsphys->ds_bp = origin->ds_phys->ds_bp;
825 dsphys->ds_flags |= origin->ds_phys->ds_flags;
827 dmu_buf_will_dirty(origin->ds_dbuf, tx);
828 origin->ds_phys->ds_num_children++;
830 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
831 origin->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ohds));
832 dsphys->ds_deadlist_obj = dsl_deadlist_clone(&ohds->ds_deadlist,
833 dsphys->ds_prev_snap_txg, dsphys->ds_prev_snap_obj, tx);
834 dsl_dataset_rele(ohds, FTAG);
836 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) {
837 if (origin->ds_phys->ds_next_clones_obj == 0) {
838 origin->ds_phys->ds_next_clones_obj =
840 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx);
842 VERIFY(0 == zap_add_int(mos,
843 origin->ds_phys->ds_next_clones_obj,
847 dmu_buf_will_dirty(dd->dd_dbuf, tx);
848 dd->dd_phys->dd_origin_obj = origin->ds_object;
849 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
850 if (origin->ds_dir->dd_phys->dd_clones == 0) {
851 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx);
852 origin->ds_dir->dd_phys->dd_clones =
854 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
856 VERIFY3U(0, ==, zap_add_int(mos,
857 origin->ds_dir->dd_phys->dd_clones, dsobj, tx));
861 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
862 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
864 dmu_buf_rele(dbuf, FTAG);
866 dmu_buf_will_dirty(dd->dd_dbuf, tx);
867 dd->dd_phys->dd_head_dataset_obj = dsobj;
873 dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname,
874 dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx)
876 dsl_pool_t *dp = pdd->dd_pool;
877 uint64_t dsobj, ddobj;
880 ASSERT(lastname[0] != '@');
882 ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx);
883 VERIFY(0 == dsl_dir_open_obj(dp, ddobj, lastname, FTAG, &dd));
885 dsobj = dsl_dataset_create_sync_dd(dd, origin, flags, tx);
887 dsl_deleg_set_create_perms(dd, tx, cr);
889 dsl_dir_close(dd, FTAG);
892 * If we are creating a clone, make sure we zero out any stale
893 * data from the origin snapshots zil header.
895 if (origin != NULL) {
899 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
900 VERIFY3U(0, ==, dmu_objset_from_ds(ds, &os));
901 bzero(&os->os_zil_header, sizeof (os->os_zil_header));
902 dsl_dataset_dirty(ds, tx);
903 dsl_dataset_rele(ds, FTAG);
910 dsl_sync_task_group_t *dstg;
917 dsl_snapshot_destroy_one(const char *name, void *arg)
919 struct destroyarg *da = arg;
924 dsname = kmem_asprintf("%s@%s", name, da->snapname);
925 err = dsl_dataset_own(dsname, B_TRUE, da->dstg, &ds);
928 struct dsl_ds_destroyarg *dsda;
930 dsl_dataset_make_exclusive(ds, da->dstg);
931 dsda = kmem_zalloc(sizeof (struct dsl_ds_destroyarg), KM_SLEEP);
933 dsda->defer = da->defer;
934 dsl_sync_task_create(da->dstg, dsl_dataset_destroy_check,
935 dsl_dataset_destroy_sync, dsda, da->dstg, 0);
936 } else if (err == ENOENT) {
939 (void) strcpy(da->failed, name);
945 * Destroy 'snapname' in all descendants of 'fsname'.
947 #pragma weak dmu_snapshots_destroy = dsl_snapshots_destroy
949 dsl_snapshots_destroy(char *fsname, char *snapname, boolean_t defer)
952 struct destroyarg da;
953 dsl_sync_task_t *dst;
956 err = spa_open(fsname, &spa, FTAG);
959 da.dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
960 da.snapname = snapname;
964 err = dmu_objset_find(fsname,
965 dsl_snapshot_destroy_one, &da, DS_FIND_CHILDREN);
968 err = dsl_sync_task_group_wait(da.dstg);
970 for (dst = list_head(&da.dstg->dstg_tasks); dst;
971 dst = list_next(&da.dstg->dstg_tasks, dst)) {
972 struct dsl_ds_destroyarg *dsda = dst->dst_arg1;
973 dsl_dataset_t *ds = dsda->ds;
976 * Return the file system name that triggered the error
979 dsl_dataset_name(ds, fsname);
980 *strchr(fsname, '@') = '\0';
982 ASSERT3P(dsda->rm_origin, ==, NULL);
983 dsl_dataset_disown(ds, da.dstg);
984 kmem_free(dsda, sizeof (struct dsl_ds_destroyarg));
987 dsl_sync_task_group_destroy(da.dstg);
988 spa_close(spa, FTAG);
993 dsl_dataset_might_destroy_origin(dsl_dataset_t *ds)
995 boolean_t might_destroy = B_FALSE;
997 mutex_enter(&ds->ds_lock);
998 if (ds->ds_phys->ds_num_children == 2 && ds->ds_userrefs == 0 &&
999 DS_IS_DEFER_DESTROY(ds))
1000 might_destroy = B_TRUE;
1001 mutex_exit(&ds->ds_lock);
1003 return (might_destroy);
1007 * If we're removing a clone, and these three conditions are true:
1008 * 1) the clone's origin has no other children
1009 * 2) the clone's origin has no user references
1010 * 3) the clone's origin has been marked for deferred destruction
1011 * Then, prepare to remove the origin as part of this sync task group.
1014 dsl_dataset_origin_rm_prep(struct dsl_ds_destroyarg *dsda, void *tag)
1016 dsl_dataset_t *ds = dsda->ds;
1017 dsl_dataset_t *origin = ds->ds_prev;
1019 if (dsl_dataset_might_destroy_origin(origin)) {
1024 namelen = dsl_dataset_namelen(origin) + 1;
1025 name = kmem_alloc(namelen, KM_SLEEP);
1026 dsl_dataset_name(origin, name);
1028 error = zfs_unmount_snap(name, NULL);
1030 kmem_free(name, namelen);
1034 error = dsl_dataset_own(name, B_TRUE, tag, &origin);
1035 kmem_free(name, namelen);
1038 dsda->rm_origin = origin;
1039 dsl_dataset_make_exclusive(origin, tag);
1046 * ds must be opened as OWNER. On return (whether successful or not),
1047 * ds will be closed and caller can no longer dereference it.
1050 dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer)
1053 dsl_sync_task_group_t *dstg;
1057 struct dsl_ds_destroyarg dsda = { 0 };
1058 dsl_dataset_t dummy_ds = { 0 };
1062 if (dsl_dataset_is_snapshot(ds)) {
1063 /* Destroying a snapshot is simpler */
1064 dsl_dataset_make_exclusive(ds, tag);
1067 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
1068 dsl_dataset_destroy_check, dsl_dataset_destroy_sync,
1070 ASSERT3P(dsda.rm_origin, ==, NULL);
1078 dummy_ds.ds_dir = dd;
1079 dummy_ds.ds_object = ds->ds_object;
1082 * Check for errors and mark this ds as inconsistent, in
1083 * case we crash while freeing the objects.
1085 err = dsl_sync_task_do(dd->dd_pool, dsl_dataset_destroy_begin_check,
1086 dsl_dataset_destroy_begin_sync, ds, NULL, 0);
1090 err = dmu_objset_from_ds(ds, &os);
1095 * remove the objects in open context, so that we won't
1096 * have too much to do in syncing context.
1098 for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE,
1099 ds->ds_phys->ds_prev_snap_txg)) {
1101 * Ignore errors, if there is not enough disk space
1102 * we will deal with it in dsl_dataset_destroy_sync().
1104 (void) dmu_free_object(os, obj);
1110 * Only the ZIL knows how to free log blocks.
1112 zil_destroy(dmu_objset_zil(os), B_FALSE);
1115 * Sync out all in-flight IO.
1117 txg_wait_synced(dd->dd_pool, 0);
1120 * If we managed to free all the objects in open
1121 * context, the user space accounting should be zero.
1123 if (ds->ds_phys->ds_bp.blk_fill == 0 &&
1124 dmu_objset_userused_enabled(os)) {
1127 ASSERT(zap_count(os, DMU_USERUSED_OBJECT, &count) != 0 ||
1129 ASSERT(zap_count(os, DMU_GROUPUSED_OBJECT, &count) != 0 ||
1133 rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
1134 err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd);
1135 rw_exit(&dd->dd_pool->dp_config_rwlock);
1141 * Blow away the dsl_dir + head dataset.
1143 dsl_dataset_make_exclusive(ds, tag);
1145 * If we're removing a clone, we might also need to remove its
1149 dsda.need_prep = B_FALSE;
1150 if (dsl_dir_is_clone(dd)) {
1151 err = dsl_dataset_origin_rm_prep(&dsda, tag);
1153 dsl_dir_close(dd, FTAG);
1158 dstg = dsl_sync_task_group_create(ds->ds_dir->dd_pool);
1159 dsl_sync_task_create(dstg, dsl_dataset_destroy_check,
1160 dsl_dataset_destroy_sync, &dsda, tag, 0);
1161 dsl_sync_task_create(dstg, dsl_dir_destroy_check,
1162 dsl_dir_destroy_sync, &dummy_ds, FTAG, 0);
1163 err = dsl_sync_task_group_wait(dstg);
1164 dsl_sync_task_group_destroy(dstg);
1167 * We could be racing against 'zfs release' or 'zfs destroy -d'
1168 * on the origin snap, in which case we can get EBUSY if we
1169 * needed to destroy the origin snap but were not ready to
1172 if (dsda.need_prep) {
1173 ASSERT(err == EBUSY);
1174 ASSERT(dsl_dir_is_clone(dd));
1175 ASSERT(dsda.rm_origin == NULL);
1177 } while (dsda.need_prep);
1179 if (dsda.rm_origin != NULL)
1180 dsl_dataset_disown(dsda.rm_origin, tag);
1182 /* if it is successful, dsl_dir_destroy_sync will close the dd */
1184 dsl_dir_close(dd, FTAG);
1186 dsl_dataset_disown(ds, tag);
1191 dsl_dataset_get_blkptr(dsl_dataset_t *ds)
1193 return (&ds->ds_phys->ds_bp);
1197 dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx)
1199 ASSERT(dmu_tx_is_syncing(tx));
1200 /* If it's the meta-objset, set dp_meta_rootbp */
1202 tx->tx_pool->dp_meta_rootbp = *bp;
1204 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1205 ds->ds_phys->ds_bp = *bp;
1210 dsl_dataset_get_spa(dsl_dataset_t *ds)
1212 return (ds->ds_dir->dd_pool->dp_spa);
1216 dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx)
1220 if (ds == NULL) /* this is the meta-objset */
1223 ASSERT(ds->ds_objset != NULL);
1225 if (ds->ds_phys->ds_next_snap_obj != 0)
1226 panic("dirtying snapshot!");
1228 dp = ds->ds_dir->dd_pool;
1230 if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg) == 0) {
1231 /* up the hold count until we can be written out */
1232 dmu_buf_add_ref(ds->ds_dbuf, ds);
1237 * The unique space in the head dataset can be calculated by subtracting
1238 * the space used in the most recent snapshot, that is still being used
1239 * in this file system, from the space currently in use. To figure out
1240 * the space in the most recent snapshot still in use, we need to take
1241 * the total space used in the snapshot and subtract out the space that
1242 * has been freed up since the snapshot was taken.
1245 dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds)
1248 uint64_t dlused, dlcomp, dluncomp;
1250 ASSERT(!dsl_dataset_is_snapshot(ds));
1252 if (ds->ds_phys->ds_prev_snap_obj != 0)
1253 mrs_used = ds->ds_prev->ds_phys->ds_used_bytes;
1257 dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp);
1259 ASSERT3U(dlused, <=, mrs_used);
1260 ds->ds_phys->ds_unique_bytes =
1261 ds->ds_phys->ds_used_bytes - (mrs_used - dlused);
1263 if (spa_version(ds->ds_dir->dd_pool->dp_spa) >=
1264 SPA_VERSION_UNIQUE_ACCURATE)
1265 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
1275 kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf,
1276 const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
1278 struct killarg *ka = arg;
1279 dmu_tx_t *tx = ka->tx;
1284 if (zb->zb_level == ZB_ZIL_LEVEL) {
1285 ASSERT(zilog != NULL);
1287 * It's a block in the intent log. It has no
1288 * accounting, so just free it.
1290 dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp);
1292 ASSERT(zilog == NULL);
1293 ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg);
1294 (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE);
1302 dsl_dataset_destroy_begin_check(void *arg1, void *arg2, dmu_tx_t *tx)
1304 dsl_dataset_t *ds = arg1;
1305 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1310 * Can't delete a head dataset if there are snapshots of it.
1311 * (Except if the only snapshots are from the branch we cloned
1314 if (ds->ds_prev != NULL &&
1315 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object)
1319 * This is really a dsl_dir thing, but check it here so that
1320 * we'll be less likely to leave this dataset inconsistent &
1323 err = zap_count(mos, ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count);
1334 dsl_dataset_destroy_begin_sync(void *arg1, void *arg2, dmu_tx_t *tx)
1336 dsl_dataset_t *ds = arg1;
1337 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1339 /* Mark it as inconsistent on-disk, in case we crash */
1340 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1341 ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT;
1343 spa_history_log_internal(LOG_DS_DESTROY_BEGIN, dp->dp_spa, tx,
1344 "dataset = %llu", ds->ds_object);
1348 dsl_dataset_origin_check(struct dsl_ds_destroyarg *dsda, void *tag,
1351 dsl_dataset_t *ds = dsda->ds;
1352 dsl_dataset_t *ds_prev = ds->ds_prev;
1354 if (dsl_dataset_might_destroy_origin(ds_prev)) {
1355 struct dsl_ds_destroyarg ndsda = {0};
1358 * If we're not prepared to remove the origin, don't remove
1361 if (dsda->rm_origin == NULL) {
1362 dsda->need_prep = B_TRUE;
1367 ndsda.is_origin_rm = B_TRUE;
1368 return (dsl_dataset_destroy_check(&ndsda, tag, tx));
1372 * If we're not going to remove the origin after all,
1373 * undo the open context setup.
1375 if (dsda->rm_origin != NULL) {
1376 dsl_dataset_disown(dsda->rm_origin, tag);
1377 dsda->rm_origin = NULL;
1384 * If you add new checks here, you may need to add
1385 * additional checks to the "temporary" case in
1386 * snapshot_check() in dmu_objset.c.
1390 dsl_dataset_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx)
1392 struct dsl_ds_destroyarg *dsda = arg1;
1393 dsl_dataset_t *ds = dsda->ds;
1395 /* we have an owner hold, so noone else can destroy us */
1396 ASSERT(!DSL_DATASET_IS_DESTROYED(ds));
1399 * Only allow deferred destroy on pools that support it.
1400 * NOTE: deferred destroy is only supported on snapshots.
1403 if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
1404 SPA_VERSION_USERREFS)
1406 ASSERT(dsl_dataset_is_snapshot(ds));
1411 * Can't delete a head dataset if there are snapshots of it.
1412 * (Except if the only snapshots are from the branch we cloned
1415 if (ds->ds_prev != NULL &&
1416 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object)
1420 * If we made changes this txg, traverse_dsl_dataset won't find
1423 if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg)
1426 if (dsl_dataset_is_snapshot(ds)) {
1428 * If this snapshot has an elevated user reference count,
1429 * we can't destroy it yet.
1431 if (ds->ds_userrefs > 0 && !dsda->releasing)
1434 mutex_enter(&ds->ds_lock);
1436 * Can't delete a branch point. However, if we're destroying
1437 * a clone and removing its origin due to it having a user
1438 * hold count of 0 and having been marked for deferred destroy,
1439 * it's OK for the origin to have a single clone.
1441 if (ds->ds_phys->ds_num_children >
1442 (dsda->is_origin_rm ? 2 : 1)) {
1443 mutex_exit(&ds->ds_lock);
1446 mutex_exit(&ds->ds_lock);
1447 } else if (dsl_dir_is_clone(ds->ds_dir)) {
1448 return (dsl_dataset_origin_check(dsda, arg2, tx));
1451 /* XXX we should do some i/o error checking... */
1463 dsl_dataset_refs_gone(dmu_buf_t *db, void *argv)
1465 struct refsarg *arg = argv;
1467 mutex_enter(&arg->lock);
1469 cv_signal(&arg->cv);
1470 mutex_exit(&arg->lock);
1474 dsl_dataset_drain_refs(dsl_dataset_t *ds, void *tag)
1478 bzero(&arg, sizeof(arg));
1479 mutex_init(&arg.lock, NULL, MUTEX_DEFAULT, NULL);
1480 cv_init(&arg.cv, NULL, CV_DEFAULT, NULL);
1482 (void) dmu_buf_update_user(ds->ds_dbuf, ds, &arg, &ds->ds_phys,
1483 dsl_dataset_refs_gone);
1484 dmu_buf_rele(ds->ds_dbuf, tag);
1485 mutex_enter(&arg.lock);
1487 cv_wait(&arg.cv, &arg.lock);
1489 mutex_exit(&arg.lock);
1492 mutex_destroy(&arg.lock);
1493 cv_destroy(&arg.cv);
1497 remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj, dmu_tx_t *tx)
1499 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1503 ASSERT(ds->ds_phys->ds_num_children >= 2);
1504 err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx);
1506 * The err should not be ENOENT, but a bug in a previous version
1507 * of the code could cause upgrade_clones_cb() to not set
1508 * ds_next_snap_obj when it should, leading to a missing entry.
1509 * If we knew that the pool was created after
1510 * SPA_VERSION_NEXT_CLONES, we could assert that it isn't
1511 * ENOENT. However, at least we can check that we don't have
1512 * too many entries in the next_clones_obj even after failing to
1515 if (err != ENOENT) {
1516 VERIFY3U(err, ==, 0);
1518 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj,
1520 ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2);
1524 dsl_dataset_remove_clones_key(dsl_dataset_t *ds, uint64_t mintxg, dmu_tx_t *tx)
1526 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1531 * If it is the old version, dd_clones doesn't exist so we can't
1532 * find the clones, but deadlist_remove_key() is a no-op so it
1535 if (ds->ds_dir->dd_phys->dd_clones == 0)
1538 for (zap_cursor_init(&zc, mos, ds->ds_dir->dd_phys->dd_clones);
1539 zap_cursor_retrieve(&zc, &za) == 0;
1540 zap_cursor_advance(&zc)) {
1541 dsl_dataset_t *clone;
1543 VERIFY3U(0, ==, dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
1544 za.za_first_integer, FTAG, &clone));
1545 if (clone->ds_dir->dd_origin_txg > mintxg) {
1546 dsl_deadlist_remove_key(&clone->ds_deadlist,
1548 dsl_dataset_remove_clones_key(clone, mintxg, tx);
1550 dsl_dataset_rele(clone, FTAG);
1552 zap_cursor_fini(&zc);
1555 struct process_old_arg {
1557 dsl_dataset_t *ds_prev;
1558 boolean_t after_branch_point;
1560 uint64_t used, comp, uncomp;
1564 process_old_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
1566 struct process_old_arg *poa = arg;
1567 dsl_pool_t *dp = poa->ds->ds_dir->dd_pool;
1569 if (bp->blk_birth <= poa->ds->ds_phys->ds_prev_snap_txg) {
1570 dsl_deadlist_insert(&poa->ds->ds_deadlist, bp, tx);
1571 if (poa->ds_prev && !poa->after_branch_point &&
1573 poa->ds_prev->ds_phys->ds_prev_snap_txg) {
1574 poa->ds_prev->ds_phys->ds_unique_bytes +=
1575 bp_get_dsize_sync(dp->dp_spa, bp);
1578 poa->used += bp_get_dsize_sync(dp->dp_spa, bp);
1579 poa->comp += BP_GET_PSIZE(bp);
1580 poa->uncomp += BP_GET_UCSIZE(bp);
1581 dsl_free_sync(poa->pio, dp, tx->tx_txg, bp);
1587 process_old_deadlist(dsl_dataset_t *ds, dsl_dataset_t *ds_prev,
1588 dsl_dataset_t *ds_next, boolean_t after_branch_point, dmu_tx_t *tx)
1590 struct process_old_arg poa = { 0 };
1591 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1592 objset_t *mos = dp->dp_meta_objset;
1594 ASSERT(ds->ds_deadlist.dl_oldfmt);
1595 ASSERT(ds_next->ds_deadlist.dl_oldfmt);
1598 poa.ds_prev = ds_prev;
1599 poa.after_branch_point = after_branch_point;
1600 poa.pio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
1601 VERIFY3U(0, ==, bpobj_iterate(&ds_next->ds_deadlist.dl_bpobj,
1602 process_old_cb, &poa, tx));
1603 VERIFY3U(zio_wait(poa.pio), ==, 0);
1604 ASSERT3U(poa.used, ==, ds->ds_phys->ds_unique_bytes);
1606 /* change snapused */
1607 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
1608 -poa.used, -poa.comp, -poa.uncomp, tx);
1610 /* swap next's deadlist to our deadlist */
1611 dsl_deadlist_close(&ds->ds_deadlist);
1612 dsl_deadlist_close(&ds_next->ds_deadlist);
1613 SWITCH64(ds_next->ds_phys->ds_deadlist_obj,
1614 ds->ds_phys->ds_deadlist_obj);
1615 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj);
1616 dsl_deadlist_open(&ds_next->ds_deadlist, mos,
1617 ds_next->ds_phys->ds_deadlist_obj);
1621 dsl_dataset_destroy_sync(void *arg1, void *tag, dmu_tx_t *tx)
1623 struct dsl_ds_destroyarg *dsda = arg1;
1624 dsl_dataset_t *ds = dsda->ds;
1626 int after_branch_point = FALSE;
1627 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1628 objset_t *mos = dp->dp_meta_objset;
1629 dsl_dataset_t *ds_prev = NULL;
1630 boolean_t wont_destroy;
1633 wont_destroy = (dsda->defer &&
1634 (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1));
1636 ASSERT(ds->ds_owner || wont_destroy);
1637 ASSERT(dsda->defer || ds->ds_phys->ds_num_children <= 1);
1638 ASSERT(ds->ds_prev == NULL ||
1639 ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object);
1640 ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg);
1643 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
1644 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1645 ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY;
1649 /* signal any waiters that this dataset is going away */
1650 mutex_enter(&ds->ds_lock);
1651 ds->ds_owner = dsl_reaper;
1652 cv_broadcast(&ds->ds_exclusive_cv);
1653 mutex_exit(&ds->ds_lock);
1655 /* Remove our reservation */
1656 if (ds->ds_reserved != 0) {
1657 dsl_prop_setarg_t psa;
1660 dsl_prop_setarg_init_uint64(&psa, "refreservation",
1661 (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED),
1663 psa.psa_effective_value = 0; /* predict default value */
1665 dsl_dataset_set_reservation_sync(ds, &psa, tx);
1666 ASSERT3U(ds->ds_reserved, ==, 0);
1669 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
1671 dsl_scan_ds_destroyed(ds, tx);
1673 obj = ds->ds_object;
1675 if (ds->ds_phys->ds_prev_snap_obj != 0) {
1677 ds_prev = ds->ds_prev;
1679 VERIFY(0 == dsl_dataset_hold_obj(dp,
1680 ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev));
1682 after_branch_point =
1683 (ds_prev->ds_phys->ds_next_snap_obj != obj);
1685 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx);
1686 if (after_branch_point &&
1687 ds_prev->ds_phys->ds_next_clones_obj != 0) {
1688 remove_from_next_clones(ds_prev, obj, tx);
1689 if (ds->ds_phys->ds_next_snap_obj != 0) {
1690 VERIFY(0 == zap_add_int(mos,
1691 ds_prev->ds_phys->ds_next_clones_obj,
1692 ds->ds_phys->ds_next_snap_obj, tx));
1695 if (after_branch_point &&
1696 ds->ds_phys->ds_next_snap_obj == 0) {
1697 /* This clone is toast. */
1698 ASSERT(ds_prev->ds_phys->ds_num_children > 1);
1699 ds_prev->ds_phys->ds_num_children--;
1702 * If the clone's origin has no other clones, no
1703 * user holds, and has been marked for deferred
1704 * deletion, then we should have done the necessary
1705 * destroy setup for it.
1707 if (ds_prev->ds_phys->ds_num_children == 1 &&
1708 ds_prev->ds_userrefs == 0 &&
1709 DS_IS_DEFER_DESTROY(ds_prev)) {
1710 ASSERT3P(dsda->rm_origin, !=, NULL);
1712 ASSERT3P(dsda->rm_origin, ==, NULL);
1714 } else if (!after_branch_point) {
1715 ds_prev->ds_phys->ds_next_snap_obj =
1716 ds->ds_phys->ds_next_snap_obj;
1720 if (dsl_dataset_is_snapshot(ds)) {
1721 dsl_dataset_t *ds_next;
1722 uint64_t old_unique;
1723 uint64_t used = 0, comp = 0, uncomp = 0;
1725 VERIFY(0 == dsl_dataset_hold_obj(dp,
1726 ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next));
1727 ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj);
1729 old_unique = ds_next->ds_phys->ds_unique_bytes;
1731 dmu_buf_will_dirty(ds_next->ds_dbuf, tx);
1732 ds_next->ds_phys->ds_prev_snap_obj =
1733 ds->ds_phys->ds_prev_snap_obj;
1734 ds_next->ds_phys->ds_prev_snap_txg =
1735 ds->ds_phys->ds_prev_snap_txg;
1736 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
1737 ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0);
1740 if (ds_next->ds_deadlist.dl_oldfmt) {
1741 process_old_deadlist(ds, ds_prev, ds_next,
1742 after_branch_point, tx);
1744 /* Adjust prev's unique space. */
1745 if (ds_prev && !after_branch_point) {
1746 dsl_deadlist_space_range(&ds_next->ds_deadlist,
1747 ds_prev->ds_phys->ds_prev_snap_txg,
1748 ds->ds_phys->ds_prev_snap_txg,
1749 &used, &comp, &uncomp);
1750 ds_prev->ds_phys->ds_unique_bytes += used;
1753 /* Adjust snapused. */
1754 dsl_deadlist_space_range(&ds_next->ds_deadlist,
1755 ds->ds_phys->ds_prev_snap_txg, UINT64_MAX,
1756 &used, &comp, &uncomp);
1757 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
1758 -used, -comp, -uncomp, tx);
1760 /* Move blocks to be freed to pool's free list. */
1761 dsl_deadlist_move_bpobj(&ds_next->ds_deadlist,
1762 &dp->dp_free_bpobj, ds->ds_phys->ds_prev_snap_txg,
1764 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir,
1765 DD_USED_HEAD, used, comp, uncomp, tx);
1766 dsl_dir_dirty(tx->tx_pool->dp_free_dir, tx);
1768 /* Merge our deadlist into next's and free it. */
1769 dsl_deadlist_merge(&ds_next->ds_deadlist,
1770 ds->ds_phys->ds_deadlist_obj, tx);
1772 dsl_deadlist_close(&ds->ds_deadlist);
1773 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx);
1775 /* Collapse range in clone heads */
1776 dsl_dataset_remove_clones_key(ds,
1777 ds->ds_phys->ds_creation_txg, tx);
1779 if (dsl_dataset_is_snapshot(ds_next)) {
1780 dsl_dataset_t *ds_nextnext;
1783 * Update next's unique to include blocks which
1784 * were previously shared by only this snapshot
1785 * and it. Those blocks will be born after the
1786 * prev snap and before this snap, and will have
1787 * died after the next snap and before the one
1788 * after that (ie. be on the snap after next's
1791 VERIFY(0 == dsl_dataset_hold_obj(dp,
1792 ds_next->ds_phys->ds_next_snap_obj,
1793 FTAG, &ds_nextnext));
1794 dsl_deadlist_space_range(&ds_nextnext->ds_deadlist,
1795 ds->ds_phys->ds_prev_snap_txg,
1796 ds->ds_phys->ds_creation_txg,
1797 &used, &comp, &uncomp);
1798 ds_next->ds_phys->ds_unique_bytes += used;
1799 dsl_dataset_rele(ds_nextnext, FTAG);
1800 ASSERT3P(ds_next->ds_prev, ==, NULL);
1802 /* Collapse range in this head. */
1804 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
1805 ds->ds_dir->dd_phys->dd_head_dataset_obj,
1807 dsl_deadlist_remove_key(&hds->ds_deadlist,
1808 ds->ds_phys->ds_creation_txg, tx);
1809 dsl_dataset_rele(hds, FTAG);
1812 ASSERT3P(ds_next->ds_prev, ==, ds);
1813 dsl_dataset_drop_ref(ds_next->ds_prev, ds_next);
1814 ds_next->ds_prev = NULL;
1816 VERIFY(0 == dsl_dataset_get_ref(dp,
1817 ds->ds_phys->ds_prev_snap_obj,
1818 ds_next, &ds_next->ds_prev));
1821 dsl_dataset_recalc_head_uniq(ds_next);
1824 * Reduce the amount of our unconsmed refreservation
1825 * being charged to our parent by the amount of
1826 * new unique data we have gained.
1828 if (old_unique < ds_next->ds_reserved) {
1830 uint64_t new_unique =
1831 ds_next->ds_phys->ds_unique_bytes;
1833 ASSERT(old_unique <= new_unique);
1834 mrsdelta = MIN(new_unique - old_unique,
1835 ds_next->ds_reserved - old_unique);
1836 dsl_dir_diduse_space(ds->ds_dir,
1837 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx);
1840 dsl_dataset_rele(ds_next, FTAG);
1843 * There's no next snapshot, so this is a head dataset.
1844 * Destroy the deadlist. Unless it's a clone, the
1845 * deadlist should be empty. (If it's a clone, it's
1846 * safe to ignore the deadlist contents.)
1850 dsl_deadlist_close(&ds->ds_deadlist);
1851 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx);
1852 ds->ds_phys->ds_deadlist_obj = 0;
1855 * Free everything that we point to (that's born after
1856 * the previous snapshot, if we are a clone)
1858 * NB: this should be very quick, because we already
1859 * freed all the objects in open context.
1863 err = traverse_dataset(ds, ds->ds_phys->ds_prev_snap_txg,
1864 TRAVERSE_POST, kill_blkptr, &ka);
1865 ASSERT3U(err, ==, 0);
1866 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) ||
1867 ds->ds_phys->ds_unique_bytes == 0);
1869 if (ds->ds_prev != NULL) {
1870 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
1871 VERIFY3U(0, ==, zap_remove_int(mos,
1872 ds->ds_prev->ds_dir->dd_phys->dd_clones,
1873 ds->ds_object, tx));
1875 dsl_dataset_rele(ds->ds_prev, ds);
1876 ds->ds_prev = ds_prev = NULL;
1881 * This must be done after the dsl_traverse(), because it will
1882 * re-open the objset.
1884 if (ds->ds_objset) {
1885 dmu_objset_evict(ds->ds_objset);
1886 ds->ds_objset = NULL;
1889 if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) {
1890 /* Erase the link in the dir */
1891 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx);
1892 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0;
1893 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0);
1894 err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx);
1897 /* remove from snapshot namespace */
1898 dsl_dataset_t *ds_head;
1899 ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0);
1900 VERIFY(0 == dsl_dataset_hold_obj(dp,
1901 ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head));
1902 VERIFY(0 == dsl_dataset_get_snapname(ds));
1907 err = dsl_dataset_snap_lookup(ds_head,
1908 ds->ds_snapname, &val);
1909 ASSERT3U(err, ==, 0);
1910 ASSERT3U(val, ==, obj);
1913 err = dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx);
1915 dsl_dataset_rele(ds_head, FTAG);
1918 if (ds_prev && ds->ds_prev != ds_prev)
1919 dsl_dataset_rele(ds_prev, FTAG);
1921 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx);
1922 spa_history_log_internal(LOG_DS_DESTROY, dp->dp_spa, tx,
1923 "dataset = %llu", ds->ds_object);
1925 if (ds->ds_phys->ds_next_clones_obj != 0) {
1927 ASSERT(0 == zap_count(mos,
1928 ds->ds_phys->ds_next_clones_obj, &count) && count == 0);
1929 VERIFY(0 == dmu_object_free(mos,
1930 ds->ds_phys->ds_next_clones_obj, tx));
1932 if (ds->ds_phys->ds_props_obj != 0)
1933 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_props_obj, tx));
1934 if (ds->ds_phys->ds_userrefs_obj != 0)
1935 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx));
1936 dsl_dir_close(ds->ds_dir, ds);
1938 dsl_dataset_drain_refs(ds, tag);
1939 VERIFY(0 == dmu_object_free(mos, obj, tx));
1941 if (dsda->rm_origin) {
1943 * Remove the origin of the clone we just destroyed.
1945 struct dsl_ds_destroyarg ndsda = {0};
1947 ndsda.ds = dsda->rm_origin;
1948 dsl_dataset_destroy_sync(&ndsda, tag, tx);
1953 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx)
1957 if (!dmu_tx_is_syncing(tx))
1961 * If there's an fs-only reservation, any blocks that might become
1962 * owned by the snapshot dataset must be accommodated by space
1963 * outside of the reservation.
1965 ASSERT(ds->ds_reserved == 0 || DS_UNIQUE_IS_ACCURATE(ds));
1966 asize = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
1967 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
1971 * Propogate any reserved space for this snapshot to other
1972 * snapshot checks in this sync group.
1975 dsl_dir_willuse_space(ds->ds_dir, asize, tx);
1981 dsl_dataset_snapshot_check(void *arg1, void *arg2, dmu_tx_t *tx)
1983 dsl_dataset_t *ds = arg1;
1984 const char *snapname = arg2;
1989 * We don't allow multiple snapshots of the same txg. If there
1990 * is already one, try again.
1992 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg)
1996 * Check for conflicting name snapshot name.
1998 err = dsl_dataset_snap_lookup(ds, snapname, &value);
2005 * Check that the dataset's name is not too long. Name consists
2006 * of the dataset's length + 1 for the @-sign + snapshot name's length
2008 if (dsl_dataset_namelen(ds) + 1 + strlen(snapname) >= MAXNAMELEN)
2009 return (ENAMETOOLONG);
2011 err = dsl_dataset_snapshot_reserve_space(ds, tx);
2015 ds->ds_trysnap_txg = tx->tx_txg;
2020 dsl_dataset_snapshot_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2022 dsl_dataset_t *ds = arg1;
2023 const char *snapname = arg2;
2024 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2026 dsl_dataset_phys_t *dsphys;
2027 uint64_t dsobj, crtxg;
2028 objset_t *mos = dp->dp_meta_objset;
2031 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
2034 * The origin's ds_creation_txg has to be < TXG_INITIAL
2036 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0)
2041 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
2042 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
2043 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
2044 dmu_buf_will_dirty(dbuf, tx);
2045 dsphys = dbuf->db_data;
2046 bzero(dsphys, sizeof (dsl_dataset_phys_t));
2047 dsphys->ds_dir_obj = ds->ds_dir->dd_object;
2048 dsphys->ds_fsid_guid = unique_create();
2049 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
2050 sizeof (dsphys->ds_guid));
2051 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj;
2052 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg;
2053 dsphys->ds_next_snap_obj = ds->ds_object;
2054 dsphys->ds_num_children = 1;
2055 dsphys->ds_creation_time = gethrestime_sec();
2056 dsphys->ds_creation_txg = crtxg;
2057 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj;
2058 dsphys->ds_used_bytes = ds->ds_phys->ds_used_bytes;
2059 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes;
2060 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes;
2061 dsphys->ds_flags = ds->ds_phys->ds_flags;
2062 dsphys->ds_bp = ds->ds_phys->ds_bp;
2063 dmu_buf_rele(dbuf, FTAG);
2065 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0);
2067 uint64_t next_clones_obj =
2068 ds->ds_prev->ds_phys->ds_next_clones_obj;
2069 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj ==
2071 ds->ds_prev->ds_phys->ds_num_children > 1);
2072 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) {
2073 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
2074 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
2075 ds->ds_prev->ds_phys->ds_creation_txg);
2076 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj;
2077 } else if (next_clones_obj != 0) {
2078 remove_from_next_clones(ds->ds_prev,
2079 dsphys->ds_next_snap_obj, tx);
2080 VERIFY3U(0, ==, zap_add_int(mos,
2081 next_clones_obj, dsobj, tx));
2086 * If we have a reference-reservation on this dataset, we will
2087 * need to increase the amount of refreservation being charged
2088 * since our unique space is going to zero.
2090 if (ds->ds_reserved) {
2092 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
2093 delta = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
2094 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV,
2098 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2099 zfs_dbgmsg("taking snapshot %s@%s/%llu; newkey=%llu",
2100 ds->ds_dir->dd_myname, snapname, dsobj,
2101 ds->ds_phys->ds_prev_snap_txg);
2102 ds->ds_phys->ds_deadlist_obj = dsl_deadlist_clone(&ds->ds_deadlist,
2103 UINT64_MAX, ds->ds_phys->ds_prev_snap_obj, tx);
2104 dsl_deadlist_close(&ds->ds_deadlist);
2105 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj);
2106 dsl_deadlist_add_key(&ds->ds_deadlist,
2107 ds->ds_phys->ds_prev_snap_txg, tx);
2109 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg);
2110 ds->ds_phys->ds_prev_snap_obj = dsobj;
2111 ds->ds_phys->ds_prev_snap_txg = crtxg;
2112 ds->ds_phys->ds_unique_bytes = 0;
2113 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
2114 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
2116 err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj,
2117 snapname, 8, 1, &dsobj, tx);
2121 dsl_dataset_drop_ref(ds->ds_prev, ds);
2122 VERIFY(0 == dsl_dataset_get_ref(dp,
2123 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev));
2125 dsl_scan_ds_snapshotted(ds, tx);
2127 dsl_dir_snap_cmtime_update(ds->ds_dir);
2129 spa_history_log_internal(LOG_DS_SNAPSHOT, dp->dp_spa, tx,
2130 "dataset = %llu", dsobj);
2134 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx)
2136 ASSERT(dmu_tx_is_syncing(tx));
2137 ASSERT(ds->ds_objset != NULL);
2138 ASSERT(ds->ds_phys->ds_next_snap_obj == 0);
2141 * in case we had to change ds_fsid_guid when we opened it,
2144 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2145 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid;
2147 dsl_dir_dirty(ds->ds_dir, tx);
2148 dmu_objset_sync(ds->ds_objset, zio, tx);
2152 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv)
2154 uint64_t refd, avail, uobjs, aobjs, ratio;
2156 dsl_dir_stats(ds->ds_dir, nv);
2158 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs);
2159 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail);
2160 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd);
2162 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION,
2163 ds->ds_phys->ds_creation_time);
2164 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG,
2165 ds->ds_phys->ds_creation_txg);
2166 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA,
2168 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION,
2170 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID,
2171 ds->ds_phys->ds_guid);
2172 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE,
2173 ds->ds_phys->ds_unique_bytes);
2174 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID,
2176 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS,
2178 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY,
2179 DS_IS_DEFER_DESTROY(ds) ? 1 : 0);
2181 ratio = ds->ds_phys->ds_compressed_bytes == 0 ? 100 :
2182 (ds->ds_phys->ds_uncompressed_bytes * 100 /
2183 ds->ds_phys->ds_compressed_bytes);
2184 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRATIO, ratio);
2186 if (ds->ds_phys->ds_next_snap_obj) {
2188 * This is a snapshot; override the dd's space used with
2189 * our unique space and compression ratio.
2191 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED,
2192 ds->ds_phys->ds_unique_bytes);
2193 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, ratio);
2198 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat)
2200 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg;
2201 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT;
2202 stat->dds_guid = ds->ds_phys->ds_guid;
2203 if (ds->ds_phys->ds_next_snap_obj) {
2204 stat->dds_is_snapshot = B_TRUE;
2205 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1;
2207 stat->dds_is_snapshot = B_FALSE;
2208 stat->dds_num_clones = 0;
2211 /* clone origin is really a dsl_dir thing... */
2212 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER);
2213 if (dsl_dir_is_clone(ds->ds_dir)) {
2216 VERIFY(0 == dsl_dataset_get_ref(ds->ds_dir->dd_pool,
2217 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods));
2218 dsl_dataset_name(ods, stat->dds_origin);
2219 dsl_dataset_drop_ref(ods, FTAG);
2221 stat->dds_origin[0] = '\0';
2223 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock);
2227 dsl_dataset_fsid_guid(dsl_dataset_t *ds)
2229 return (ds->ds_fsid_guid);
2233 dsl_dataset_space(dsl_dataset_t *ds,
2234 uint64_t *refdbytesp, uint64_t *availbytesp,
2235 uint64_t *usedobjsp, uint64_t *availobjsp)
2237 *refdbytesp = ds->ds_phys->ds_used_bytes;
2238 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE);
2239 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes)
2240 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes;
2241 if (ds->ds_quota != 0) {
2243 * Adjust available bytes according to refquota
2245 if (*refdbytesp < ds->ds_quota)
2246 *availbytesp = MIN(*availbytesp,
2247 ds->ds_quota - *refdbytesp);
2251 *usedobjsp = ds->ds_phys->ds_bp.blk_fill;
2252 *availobjsp = DN_MAX_OBJECT - *usedobjsp;
2256 dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds)
2258 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2260 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) ||
2261 dsl_pool_sync_context(dp));
2262 if (ds->ds_prev == NULL)
2264 if (ds->ds_phys->ds_bp.blk_birth >
2265 ds->ds_prev->ds_phys->ds_creation_txg) {
2266 objset_t *os, *os_prev;
2268 * It may be that only the ZIL differs, because it was
2269 * reset in the head. Don't count that as being
2272 if (dmu_objset_from_ds(ds, &os) != 0)
2274 if (dmu_objset_from_ds(ds->ds_prev, &os_prev) != 0)
2276 return (bcmp(&os->os_phys->os_meta_dnode,
2277 &os_prev->os_phys->os_meta_dnode,
2278 sizeof (os->os_phys->os_meta_dnode)) != 0);
2285 dsl_dataset_snapshot_rename_check(void *arg1, void *arg2, dmu_tx_t *tx)
2287 dsl_dataset_t *ds = arg1;
2288 char *newsnapname = arg2;
2289 dsl_dir_t *dd = ds->ds_dir;
2294 err = dsl_dataset_hold_obj(dd->dd_pool,
2295 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds);
2299 /* new name better not be in use */
2300 err = dsl_dataset_snap_lookup(hds, newsnapname, &val);
2301 dsl_dataset_rele(hds, FTAG);
2305 else if (err == ENOENT)
2308 /* dataset name + 1 for the "@" + the new snapshot name must fit */
2309 if (dsl_dir_namelen(ds->ds_dir) + 1 + strlen(newsnapname) >= MAXNAMELEN)
2316 dsl_dataset_snapshot_rename_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2318 char oldname[MAXPATHLEN], newname[MAXPATHLEN];
2319 dsl_dataset_t *ds = arg1;
2320 const char *newsnapname = arg2;
2321 dsl_dir_t *dd = ds->ds_dir;
2322 objset_t *mos = dd->dd_pool->dp_meta_objset;
2326 ASSERT(ds->ds_phys->ds_next_snap_obj != 0);
2328 VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool,
2329 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds));
2331 VERIFY(0 == dsl_dataset_get_snapname(ds));
2332 err = dsl_dataset_snap_remove(hds, ds->ds_snapname, tx);
2333 ASSERT3U(err, ==, 0);
2334 dsl_dataset_name(ds, oldname);
2335 mutex_enter(&ds->ds_lock);
2336 (void) strcpy(ds->ds_snapname, newsnapname);
2337 mutex_exit(&ds->ds_lock);
2338 err = zap_add(mos, hds->ds_phys->ds_snapnames_zapobj,
2339 ds->ds_snapname, 8, 1, &ds->ds_object, tx);
2340 ASSERT3U(err, ==, 0);
2341 dsl_dataset_name(ds, newname);
2343 zvol_rename_minors(oldname, newname);
2346 spa_history_log_internal(LOG_DS_RENAME, dd->dd_pool->dp_spa, tx,
2347 "dataset = %llu", ds->ds_object);
2348 dsl_dataset_rele(hds, FTAG);
2351 struct renamesnaparg {
2352 dsl_sync_task_group_t *dstg;
2353 char failed[MAXPATHLEN];
2359 dsl_snapshot_rename_one(const char *name, void *arg)
2361 struct renamesnaparg *ra = arg;
2362 dsl_dataset_t *ds = NULL;
2366 snapname = kmem_asprintf("%s@%s", name, ra->oldsnap);
2367 (void) strlcpy(ra->failed, snapname, sizeof (ra->failed));
2370 * For recursive snapshot renames the parent won't be changing
2371 * so we just pass name for both the to/from argument.
2373 err = zfs_secpolicy_rename_perms(snapname, snapname, CRED());
2376 return (err == ENOENT ? 0 : err);
2381 * For all filesystems undergoing rename, we'll need to unmount it.
2383 (void) zfs_unmount_snap(snapname, NULL);
2385 err = dsl_dataset_hold(snapname, ra->dstg, &ds);
2388 return (err == ENOENT ? 0 : err);
2390 dsl_sync_task_create(ra->dstg, dsl_dataset_snapshot_rename_check,
2391 dsl_dataset_snapshot_rename_sync, ds, ra->newsnap, 0);
2397 dsl_recursive_rename(char *oldname, const char *newname)
2400 struct renamesnaparg *ra;
2401 dsl_sync_task_t *dst;
2403 char *cp, *fsname = spa_strdup(oldname);
2404 int len = strlen(oldname) + 1;
2406 /* truncate the snapshot name to get the fsname */
2407 cp = strchr(fsname, '@');
2410 err = spa_open(fsname, &spa, FTAG);
2412 kmem_free(fsname, len);
2415 ra = kmem_alloc(sizeof (struct renamesnaparg), KM_SLEEP);
2416 ra->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
2418 ra->oldsnap = strchr(oldname, '@') + 1;
2419 ra->newsnap = strchr(newname, '@') + 1;
2422 err = dmu_objset_find(fsname, dsl_snapshot_rename_one, ra,
2424 kmem_free(fsname, len);
2427 err = dsl_sync_task_group_wait(ra->dstg);
2430 for (dst = list_head(&ra->dstg->dstg_tasks); dst;
2431 dst = list_next(&ra->dstg->dstg_tasks, dst)) {
2432 dsl_dataset_t *ds = dst->dst_arg1;
2434 dsl_dir_name(ds->ds_dir, ra->failed);
2435 (void) strlcat(ra->failed, "@", sizeof (ra->failed));
2436 (void) strlcat(ra->failed, ra->newsnap,
2437 sizeof (ra->failed));
2439 dsl_dataset_rele(ds, ra->dstg);
2443 (void) strlcpy(oldname, ra->failed, sizeof (ra->failed));
2445 dsl_sync_task_group_destroy(ra->dstg);
2446 kmem_free(ra, sizeof (struct renamesnaparg));
2447 spa_close(spa, FTAG);
2452 dsl_valid_rename(const char *oldname, void *arg)
2454 int delta = *(int *)arg;
2456 if (strlen(oldname) + delta >= MAXNAMELEN)
2457 return (ENAMETOOLONG);
2462 #pragma weak dmu_objset_rename = dsl_dataset_rename
2464 dsl_dataset_rename(char *oldname, const char *newname, boolean_t recursive)
2471 err = dsl_dir_open(oldname, FTAG, &dd, &tail);
2476 int delta = strlen(newname) - strlen(oldname);
2478 /* if we're growing, validate child name lengths */
2480 err = dmu_objset_find(oldname, dsl_valid_rename,
2481 &delta, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS);
2484 err = dsl_dir_rename(dd, newname);
2485 dsl_dir_close(dd, FTAG);
2489 if (tail[0] != '@') {
2490 /* the name ended in a nonexistent component */
2491 dsl_dir_close(dd, FTAG);
2495 dsl_dir_close(dd, FTAG);
2497 /* new name must be snapshot in same filesystem */
2498 tail = strchr(newname, '@');
2502 if (strncmp(oldname, newname, tail - newname) != 0)
2506 err = dsl_recursive_rename(oldname, newname);
2508 err = dsl_dataset_hold(oldname, FTAG, &ds);
2512 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
2513 dsl_dataset_snapshot_rename_check,
2514 dsl_dataset_snapshot_rename_sync, ds, (char *)tail, 1);
2516 dsl_dataset_rele(ds, FTAG);
2522 struct promotenode {
2528 list_t shared_snaps, origin_snaps, clone_snaps;
2529 dsl_dataset_t *origin_origin;
2530 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap;
2534 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep);
2535 static boolean_t snaplist_unstable(list_t *l);
2538 dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx)
2540 dsl_dataset_t *hds = arg1;
2541 struct promotearg *pa = arg2;
2542 struct promotenode *snap = list_head(&pa->shared_snaps);
2543 dsl_dataset_t *origin_ds = snap->ds;
2547 /* Check that it is a real clone */
2548 if (!dsl_dir_is_clone(hds->ds_dir))
2551 /* Since this is so expensive, don't do the preliminary check */
2552 if (!dmu_tx_is_syncing(tx))
2555 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE)
2558 /* compute origin's new unique space */
2559 snap = list_tail(&pa->clone_snaps);
2560 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2561 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2562 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX,
2563 &pa->unique, &unused, &unused);
2566 * Walk the snapshots that we are moving
2568 * Compute space to transfer. Consider the incremental changes
2569 * to used for each snapshot:
2570 * (my used) = (prev's used) + (blocks born) - (blocks killed)
2571 * So each snapshot gave birth to:
2572 * (blocks born) = (my used) - (prev's used) + (blocks killed)
2573 * So a sequence would look like:
2574 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0)
2575 * Which simplifies to:
2576 * uN + kN + kN-1 + ... + k1 + k0
2577 * Note however, if we stop before we reach the ORIGIN we get:
2578 * uN + kN + kN-1 + ... + kM - uM-1
2580 pa->used = origin_ds->ds_phys->ds_used_bytes;
2581 pa->comp = origin_ds->ds_phys->ds_compressed_bytes;
2582 pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes;
2583 for (snap = list_head(&pa->shared_snaps); snap;
2584 snap = list_next(&pa->shared_snaps, snap)) {
2585 uint64_t val, dlused, dlcomp, dluncomp;
2586 dsl_dataset_t *ds = snap->ds;
2588 /* Check that the snapshot name does not conflict */
2589 VERIFY(0 == dsl_dataset_get_snapname(ds));
2590 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val);
2598 /* The very first snapshot does not have a deadlist */
2599 if (ds->ds_phys->ds_prev_snap_obj == 0)
2602 dsl_deadlist_space(&ds->ds_deadlist,
2603 &dlused, &dlcomp, &dluncomp);
2606 pa->uncomp += dluncomp;
2610 * If we are a clone of a clone then we never reached ORIGIN,
2611 * so we need to subtract out the clone origin's used space.
2613 if (pa->origin_origin) {
2614 pa->used -= pa->origin_origin->ds_phys->ds_used_bytes;
2615 pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes;
2616 pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes;
2619 /* Check that there is enough space here */
2620 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir,
2626 * Compute the amounts of space that will be used by snapshots
2627 * after the promotion (for both origin and clone). For each,
2628 * it is the amount of space that will be on all of their
2629 * deadlists (that was not born before their new origin).
2631 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2635 * Note, typically this will not be a clone of a clone,
2636 * so dd_origin_txg will be < TXG_INITIAL, so
2637 * these snaplist_space() -> dsl_deadlist_space_range()
2638 * calls will be fast because they do not have to
2639 * iterate over all bps.
2641 snap = list_head(&pa->origin_snaps);
2642 err = snaplist_space(&pa->shared_snaps,
2643 snap->ds->ds_dir->dd_origin_txg, &pa->cloneusedsnap);
2647 err = snaplist_space(&pa->clone_snaps,
2648 snap->ds->ds_dir->dd_origin_txg, &space);
2651 pa->cloneusedsnap += space;
2653 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2654 err = snaplist_space(&pa->origin_snaps,
2655 origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap);
2662 pa->err_ds = snap->ds->ds_snapname;
2667 dsl_dataset_promote_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2669 dsl_dataset_t *hds = arg1;
2670 struct promotearg *pa = arg2;
2671 struct promotenode *snap = list_head(&pa->shared_snaps);
2672 dsl_dataset_t *origin_ds = snap->ds;
2673 dsl_dataset_t *origin_head;
2674 dsl_dir_t *dd = hds->ds_dir;
2675 dsl_pool_t *dp = hds->ds_dir->dd_pool;
2676 dsl_dir_t *odd = NULL;
2677 uint64_t oldnext_obj;
2680 ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE));
2682 snap = list_head(&pa->origin_snaps);
2683 origin_head = snap->ds;
2686 * We need to explicitly open odd, since origin_ds's dd will be
2689 VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object,
2692 /* change origin's next snap */
2693 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx);
2694 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj;
2695 snap = list_tail(&pa->clone_snaps);
2696 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2697 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object;
2699 /* change the origin's next clone */
2700 if (origin_ds->ds_phys->ds_next_clones_obj) {
2701 remove_from_next_clones(origin_ds, snap->ds->ds_object, tx);
2702 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2703 origin_ds->ds_phys->ds_next_clones_obj,
2708 dmu_buf_will_dirty(dd->dd_dbuf, tx);
2709 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object);
2710 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj;
2711 dd->dd_origin_txg = origin_head->ds_dir->dd_origin_txg;
2712 dmu_buf_will_dirty(odd->dd_dbuf, tx);
2713 odd->dd_phys->dd_origin_obj = origin_ds->ds_object;
2714 origin_head->ds_dir->dd_origin_txg =
2715 origin_ds->ds_phys->ds_creation_txg;
2717 /* change dd_clone entries */
2718 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2719 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
2720 odd->dd_phys->dd_clones, hds->ds_object, tx));
2721 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2722 pa->origin_origin->ds_dir->dd_phys->dd_clones,
2723 hds->ds_object, tx));
2725 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
2726 pa->origin_origin->ds_dir->dd_phys->dd_clones,
2727 origin_head->ds_object, tx));
2728 if (dd->dd_phys->dd_clones == 0) {
2729 dd->dd_phys->dd_clones = zap_create(dp->dp_meta_objset,
2730 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
2732 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2733 dd->dd_phys->dd_clones, origin_head->ds_object, tx));
2737 /* move snapshots to this dir */
2738 for (snap = list_head(&pa->shared_snaps); snap;
2739 snap = list_next(&pa->shared_snaps, snap)) {
2740 dsl_dataset_t *ds = snap->ds;
2742 /* unregister props as dsl_dir is changing */
2743 if (ds->ds_objset) {
2744 dmu_objset_evict(ds->ds_objset);
2745 ds->ds_objset = NULL;
2747 /* move snap name entry */
2748 VERIFY(0 == dsl_dataset_get_snapname(ds));
2749 VERIFY(0 == dsl_dataset_snap_remove(origin_head,
2750 ds->ds_snapname, tx));
2751 VERIFY(0 == zap_add(dp->dp_meta_objset,
2752 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname,
2753 8, 1, &ds->ds_object, tx));
2755 /* change containing dsl_dir */
2756 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2757 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object);
2758 ds->ds_phys->ds_dir_obj = dd->dd_object;
2759 ASSERT3P(ds->ds_dir, ==, odd);
2760 dsl_dir_close(ds->ds_dir, ds);
2761 VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object,
2762 NULL, ds, &ds->ds_dir));
2764 /* move any clone references */
2765 if (ds->ds_phys->ds_next_clones_obj &&
2766 spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2770 for (zap_cursor_init(&zc, dp->dp_meta_objset,
2771 ds->ds_phys->ds_next_clones_obj);
2772 zap_cursor_retrieve(&zc, &za) == 0;
2773 zap_cursor_advance(&zc)) {
2774 dsl_dataset_t *cnds;
2777 if (za.za_first_integer == oldnext_obj) {
2779 * We've already moved the
2780 * origin's reference.
2785 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
2786 za.za_first_integer, FTAG, &cnds));
2787 o = cnds->ds_dir->dd_phys->dd_head_dataset_obj;
2789 VERIFY3U(zap_remove_int(dp->dp_meta_objset,
2790 odd->dd_phys->dd_clones, o, tx), ==, 0);
2791 VERIFY3U(zap_add_int(dp->dp_meta_objset,
2792 dd->dd_phys->dd_clones, o, tx), ==, 0);
2793 dsl_dataset_rele(cnds, FTAG);
2795 zap_cursor_fini(&zc);
2798 ASSERT3U(dsl_prop_numcb(ds), ==, 0);
2802 * Change space accounting.
2803 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either
2804 * both be valid, or both be 0 (resulting in delta == 0). This
2805 * is true for each of {clone,origin} independently.
2808 delta = pa->cloneusedsnap -
2809 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2810 ASSERT3S(delta, >=, 0);
2811 ASSERT3U(pa->used, >=, delta);
2812 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx);
2813 dsl_dir_diduse_space(dd, DD_USED_HEAD,
2814 pa->used - delta, pa->comp, pa->uncomp, tx);
2816 delta = pa->originusedsnap -
2817 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2818 ASSERT3S(delta, <=, 0);
2819 ASSERT3U(pa->used, >=, -delta);
2820 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx);
2821 dsl_dir_diduse_space(odd, DD_USED_HEAD,
2822 -pa->used - delta, -pa->comp, -pa->uncomp, tx);
2824 origin_ds->ds_phys->ds_unique_bytes = pa->unique;
2826 /* log history record */
2827 spa_history_log_internal(LOG_DS_PROMOTE, dd->dd_pool->dp_spa, tx,
2828 "dataset = %llu", hds->ds_object);
2830 dsl_dir_close(odd, FTAG);
2833 static char *snaplist_tag = "snaplist";
2835 * Make a list of dsl_dataset_t's for the snapshots between first_obj
2836 * (exclusive) and last_obj (inclusive). The list will be in reverse
2837 * order (last_obj will be the list_head()). If first_obj == 0, do all
2838 * snapshots back to this dataset's origin.
2841 snaplist_make(dsl_pool_t *dp, boolean_t own,
2842 uint64_t first_obj, uint64_t last_obj, list_t *l)
2844 uint64_t obj = last_obj;
2846 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock));
2848 list_create(l, sizeof (struct promotenode),
2849 offsetof(struct promotenode, link));
2851 while (obj != first_obj) {
2853 struct promotenode *snap;
2857 err = dsl_dataset_own_obj(dp, obj,
2858 0, snaplist_tag, &ds);
2860 dsl_dataset_make_exclusive(ds, snaplist_tag);
2862 err = dsl_dataset_hold_obj(dp, obj, snaplist_tag, &ds);
2864 if (err == ENOENT) {
2865 /* lost race with snapshot destroy */
2866 struct promotenode *last = list_tail(l);
2867 ASSERT(obj != last->ds->ds_phys->ds_prev_snap_obj);
2868 obj = last->ds->ds_phys->ds_prev_snap_obj;
2875 first_obj = ds->ds_dir->dd_phys->dd_origin_obj;
2877 snap = kmem_alloc(sizeof (struct promotenode), KM_SLEEP);
2879 list_insert_tail(l, snap);
2880 obj = ds->ds_phys->ds_prev_snap_obj;
2887 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep)
2889 struct promotenode *snap;
2892 for (snap = list_head(l); snap; snap = list_next(l, snap)) {
2893 uint64_t used, comp, uncomp;
2894 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2895 mintxg, UINT64_MAX, &used, &comp, &uncomp);
2902 snaplist_destroy(list_t *l, boolean_t own)
2904 struct promotenode *snap;
2906 if (!l || !list_link_active(&l->list_head))
2909 while ((snap = list_tail(l)) != NULL) {
2910 list_remove(l, snap);
2912 dsl_dataset_disown(snap->ds, snaplist_tag);
2914 dsl_dataset_rele(snap->ds, snaplist_tag);
2915 kmem_free(snap, sizeof (struct promotenode));
2921 * Promote a clone. Nomenclature note:
2922 * "clone" or "cds": the original clone which is being promoted
2923 * "origin" or "ods": the snapshot which is originally clone's origin
2924 * "origin head" or "ohds": the dataset which is the head
2925 * (filesystem/volume) for the origin
2926 * "origin origin": the origin of the origin's filesystem (typically
2927 * NULL, indicating that the clone is not a clone of a clone).
2930 dsl_dataset_promote(const char *name, char *conflsnap)
2935 dmu_object_info_t doi;
2936 struct promotearg pa = { 0 };
2937 struct promotenode *snap;
2940 err = dsl_dataset_hold(name, FTAG, &ds);
2946 err = dmu_object_info(dp->dp_meta_objset,
2947 ds->ds_phys->ds_snapnames_zapobj, &doi);
2949 dsl_dataset_rele(ds, FTAG);
2953 if (dsl_dataset_is_snapshot(ds) || dd->dd_phys->dd_origin_obj == 0) {
2954 dsl_dataset_rele(ds, FTAG);
2959 * We are going to inherit all the snapshots taken before our
2960 * origin (i.e., our new origin will be our parent's origin).
2961 * Take ownership of them so that we can rename them into our
2964 rw_enter(&dp->dp_config_rwlock, RW_READER);
2966 err = snaplist_make(dp, B_TRUE, 0, dd->dd_phys->dd_origin_obj,
2971 err = snaplist_make(dp, B_FALSE, 0, ds->ds_object, &pa.clone_snaps);
2975 snap = list_head(&pa.shared_snaps);
2976 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj);
2977 err = snaplist_make(dp, B_FALSE, dd->dd_phys->dd_origin_obj,
2978 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj, &pa.origin_snaps);
2982 if (snap->ds->ds_dir->dd_phys->dd_origin_obj != 0) {
2983 err = dsl_dataset_hold_obj(dp,
2984 snap->ds->ds_dir->dd_phys->dd_origin_obj,
2985 FTAG, &pa.origin_origin);
2991 rw_exit(&dp->dp_config_rwlock);
2994 * Add in 128x the snapnames zapobj size, since we will be moving
2995 * a bunch of snapnames to the promoted ds, and dirtying their
2999 err = dsl_sync_task_do(dp, dsl_dataset_promote_check,
3000 dsl_dataset_promote_sync, ds, &pa,
3001 2 + 2 * doi.doi_physical_blocks_512);
3002 if (err && pa.err_ds && conflsnap)
3003 (void) strncpy(conflsnap, pa.err_ds, MAXNAMELEN);
3006 snaplist_destroy(&pa.shared_snaps, B_TRUE);
3007 snaplist_destroy(&pa.clone_snaps, B_FALSE);
3008 snaplist_destroy(&pa.origin_snaps, B_FALSE);
3009 if (pa.origin_origin)
3010 dsl_dataset_rele(pa.origin_origin, FTAG);
3011 dsl_dataset_rele(ds, FTAG);
3015 struct cloneswaparg {
3016 dsl_dataset_t *cds; /* clone dataset */
3017 dsl_dataset_t *ohds; /* origin's head dataset */
3019 int64_t unused_refres_delta; /* change in unconsumed refreservation */
3024 dsl_dataset_clone_swap_check(void *arg1, void *arg2, dmu_tx_t *tx)
3026 struct cloneswaparg *csa = arg1;
3028 /* they should both be heads */
3029 if (dsl_dataset_is_snapshot(csa->cds) ||
3030 dsl_dataset_is_snapshot(csa->ohds))
3033 /* the branch point should be just before them */
3034 if (csa->cds->ds_prev != csa->ohds->ds_prev)
3037 /* cds should be the clone (unless they are unrelated) */
3038 if (csa->cds->ds_prev != NULL &&
3039 csa->cds->ds_prev != csa->cds->ds_dir->dd_pool->dp_origin_snap &&
3040 csa->ohds->ds_object !=
3041 csa->cds->ds_prev->ds_phys->ds_next_snap_obj)
3044 /* the clone should be a child of the origin */
3045 if (csa->cds->ds_dir->dd_parent != csa->ohds->ds_dir)
3048 /* ohds shouldn't be modified unless 'force' */
3049 if (!csa->force && dsl_dataset_modified_since_lastsnap(csa->ohds))
3052 /* adjust amount of any unconsumed refreservation */
3053 csa->unused_refres_delta =
3054 (int64_t)MIN(csa->ohds->ds_reserved,
3055 csa->ohds->ds_phys->ds_unique_bytes) -
3056 (int64_t)MIN(csa->ohds->ds_reserved,
3057 csa->cds->ds_phys->ds_unique_bytes);
3059 if (csa->unused_refres_delta > 0 &&
3060 csa->unused_refres_delta >
3061 dsl_dir_space_available(csa->ohds->ds_dir, NULL, 0, TRUE))
3064 if (csa->ohds->ds_quota != 0 &&
3065 csa->cds->ds_phys->ds_unique_bytes > csa->ohds->ds_quota)
3073 dsl_dataset_clone_swap_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3075 struct cloneswaparg *csa = arg1;
3076 dsl_pool_t *dp = csa->cds->ds_dir->dd_pool;
3078 ASSERT(csa->cds->ds_reserved == 0);
3079 ASSERT(csa->ohds->ds_quota == 0 ||
3080 csa->cds->ds_phys->ds_unique_bytes <= csa->ohds->ds_quota);
3082 dmu_buf_will_dirty(csa->cds->ds_dbuf, tx);
3083 dmu_buf_will_dirty(csa->ohds->ds_dbuf, tx);
3085 if (csa->cds->ds_objset != NULL) {
3086 dmu_objset_evict(csa->cds->ds_objset);
3087 csa->cds->ds_objset = NULL;
3090 if (csa->ohds->ds_objset != NULL) {
3091 dmu_objset_evict(csa->ohds->ds_objset);
3092 csa->ohds->ds_objset = NULL;
3096 * Reset origin's unique bytes, if it exists.
3098 if (csa->cds->ds_prev) {
3099 dsl_dataset_t *origin = csa->cds->ds_prev;
3100 uint64_t comp, uncomp;
3102 dmu_buf_will_dirty(origin->ds_dbuf, tx);
3103 dsl_deadlist_space_range(&csa->cds->ds_deadlist,
3104 origin->ds_phys->ds_prev_snap_txg, UINT64_MAX,
3105 &origin->ds_phys->ds_unique_bytes, &comp, &uncomp);
3111 tmp = csa->ohds->ds_phys->ds_bp;
3112 csa->ohds->ds_phys->ds_bp = csa->cds->ds_phys->ds_bp;
3113 csa->cds->ds_phys->ds_bp = tmp;
3116 /* set dd_*_bytes */
3118 int64_t dused, dcomp, duncomp;
3119 uint64_t cdl_used, cdl_comp, cdl_uncomp;
3120 uint64_t odl_used, odl_comp, odl_uncomp;
3122 ASSERT3U(csa->cds->ds_dir->dd_phys->
3123 dd_used_breakdown[DD_USED_SNAP], ==, 0);
3125 dsl_deadlist_space(&csa->cds->ds_deadlist,
3126 &cdl_used, &cdl_comp, &cdl_uncomp);
3127 dsl_deadlist_space(&csa->ohds->ds_deadlist,
3128 &odl_used, &odl_comp, &odl_uncomp);
3130 dused = csa->cds->ds_phys->ds_used_bytes + cdl_used -
3131 (csa->ohds->ds_phys->ds_used_bytes + odl_used);
3132 dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp -
3133 (csa->ohds->ds_phys->ds_compressed_bytes + odl_comp);
3134 duncomp = csa->cds->ds_phys->ds_uncompressed_bytes +
3136 (csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp);
3138 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD,
3139 dused, dcomp, duncomp, tx);
3140 dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD,
3141 -dused, -dcomp, -duncomp, tx);
3144 * The difference in the space used by snapshots is the
3145 * difference in snapshot space due to the head's
3146 * deadlist (since that's the only thing that's
3147 * changing that affects the snapused).
3149 dsl_deadlist_space_range(&csa->cds->ds_deadlist,
3150 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX,
3151 &cdl_used, &cdl_comp, &cdl_uncomp);
3152 dsl_deadlist_space_range(&csa->ohds->ds_deadlist,
3153 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX,
3154 &odl_used, &odl_comp, &odl_uncomp);
3155 dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used,
3156 DD_USED_HEAD, DD_USED_SNAP, tx);
3159 /* swap ds_*_bytes */
3160 SWITCH64(csa->ohds->ds_phys->ds_used_bytes,
3161 csa->cds->ds_phys->ds_used_bytes);
3162 SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes,
3163 csa->cds->ds_phys->ds_compressed_bytes);
3164 SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes,
3165 csa->cds->ds_phys->ds_uncompressed_bytes);
3166 SWITCH64(csa->ohds->ds_phys->ds_unique_bytes,
3167 csa->cds->ds_phys->ds_unique_bytes);
3169 /* apply any parent delta for change in unconsumed refreservation */
3170 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV,
3171 csa->unused_refres_delta, 0, 0, tx);
3176 dsl_deadlist_close(&csa->cds->ds_deadlist);
3177 dsl_deadlist_close(&csa->ohds->ds_deadlist);
3178 SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj,
3179 csa->cds->ds_phys->ds_deadlist_obj);
3180 dsl_deadlist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset,
3181 csa->cds->ds_phys->ds_deadlist_obj);
3182 dsl_deadlist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset,
3183 csa->ohds->ds_phys->ds_deadlist_obj);
3185 dsl_scan_ds_clone_swapped(csa->ohds, csa->cds, tx);
3189 * Swap 'clone' with its origin head datasets. Used at the end of "zfs
3190 * recv" into an existing fs to swizzle the file system to the new
3191 * version, and by "zfs rollback". Can also be used to swap two
3192 * independent head datasets if neither has any snapshots.
3195 dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head,
3198 struct cloneswaparg csa;
3201 ASSERT(clone->ds_owner);
3202 ASSERT(origin_head->ds_owner);
3205 * Need exclusive access for the swap. If we're swapping these
3206 * datasets back after an error, we already hold the locks.
3208 if (!RW_WRITE_HELD(&clone->ds_rwlock))
3209 rw_enter(&clone->ds_rwlock, RW_WRITER);
3210 if (!RW_WRITE_HELD(&origin_head->ds_rwlock) &&
3211 !rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) {
3212 rw_exit(&clone->ds_rwlock);
3213 rw_enter(&origin_head->ds_rwlock, RW_WRITER);
3214 if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) {
3215 rw_exit(&origin_head->ds_rwlock);
3220 csa.ohds = origin_head;
3222 error = dsl_sync_task_do(clone->ds_dir->dd_pool,
3223 dsl_dataset_clone_swap_check,
3224 dsl_dataset_clone_swap_sync, &csa, NULL, 9);
3229 * Given a pool name and a dataset object number in that pool,
3230 * return the name of that dataset.
3233 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf)
3240 if ((error = spa_open(pname, &spa, FTAG)) != 0)
3242 dp = spa_get_dsl(spa);
3243 rw_enter(&dp->dp_config_rwlock, RW_READER);
3244 if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) {
3245 dsl_dataset_name(ds, buf);
3246 dsl_dataset_rele(ds, FTAG);
3248 rw_exit(&dp->dp_config_rwlock);
3249 spa_close(spa, FTAG);
3255 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota,
3256 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv)
3260 ASSERT3S(asize, >, 0);
3263 * *ref_rsrv is the portion of asize that will come from any
3264 * unconsumed refreservation space.
3268 mutex_enter(&ds->ds_lock);
3270 * Make a space adjustment for reserved bytes.
3272 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) {
3274 ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
3275 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
3277 asize - MIN(asize, parent_delta(ds, asize + inflight));
3280 if (!check_quota || ds->ds_quota == 0) {
3281 mutex_exit(&ds->ds_lock);
3285 * If they are requesting more space, and our current estimate
3286 * is over quota, they get to try again unless the actual
3287 * on-disk is over quota and there are no pending changes (which
3288 * may free up space for us).
3290 if (ds->ds_phys->ds_used_bytes + inflight >= ds->ds_quota) {
3291 if (inflight > 0 || ds->ds_phys->ds_used_bytes < ds->ds_quota)
3296 mutex_exit(&ds->ds_lock);
3303 dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx)
3305 dsl_dataset_t *ds = arg1;
3306 dsl_prop_setarg_t *psa = arg2;
3309 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA)
3312 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0)
3315 if (psa->psa_effective_value == 0)
3318 if (psa->psa_effective_value < ds->ds_phys->ds_used_bytes ||
3319 psa->psa_effective_value < ds->ds_reserved)
3325 extern void dsl_prop_set_sync(void *, void *, dmu_tx_t *);
3328 dsl_dataset_set_quota_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3330 dsl_dataset_t *ds = arg1;
3331 dsl_prop_setarg_t *psa = arg2;
3332 uint64_t effective_value = psa->psa_effective_value;
3334 dsl_prop_set_sync(ds, psa, tx);
3335 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa);
3337 if (ds->ds_quota != effective_value) {
3338 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3339 ds->ds_quota = effective_value;
3341 spa_history_log_internal(LOG_DS_REFQUOTA,
3342 ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu ",
3343 (longlong_t)ds->ds_quota, ds->ds_object);
3348 dsl_dataset_set_quota(const char *dsname, zprop_source_t source, uint64_t quota)
3351 dsl_prop_setarg_t psa;
3354 dsl_prop_setarg_init_uint64(&psa, "refquota", source, "a);
3356 err = dsl_dataset_hold(dsname, FTAG, &ds);
3361 * If someone removes a file, then tries to set the quota, we
3362 * want to make sure the file freeing takes effect.
3364 txg_wait_open(ds->ds_dir->dd_pool, 0);
3366 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
3367 dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync,
3370 dsl_dataset_rele(ds, FTAG);
3375 dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx)
3377 dsl_dataset_t *ds = arg1;
3378 dsl_prop_setarg_t *psa = arg2;
3379 uint64_t effective_value;
3383 if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
3384 SPA_VERSION_REFRESERVATION)
3387 if (dsl_dataset_is_snapshot(ds))
3390 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0)
3393 effective_value = psa->psa_effective_value;
3396 * If we are doing the preliminary check in open context, the
3397 * space estimates may be inaccurate.
3399 if (!dmu_tx_is_syncing(tx))
3402 mutex_enter(&ds->ds_lock);
3403 if (!DS_UNIQUE_IS_ACCURATE(ds))
3404 dsl_dataset_recalc_head_uniq(ds);
3405 unique = ds->ds_phys->ds_unique_bytes;
3406 mutex_exit(&ds->ds_lock);
3408 if (MAX(unique, effective_value) > MAX(unique, ds->ds_reserved)) {
3409 uint64_t delta = MAX(unique, effective_value) -
3410 MAX(unique, ds->ds_reserved);
3412 if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
3414 if (ds->ds_quota > 0 &&
3415 effective_value > ds->ds_quota)
3423 dsl_dataset_set_reservation_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3425 dsl_dataset_t *ds = arg1;
3426 dsl_prop_setarg_t *psa = arg2;
3427 uint64_t effective_value = psa->psa_effective_value;
3431 dsl_prop_set_sync(ds, psa, tx);
3432 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa);
3434 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3436 mutex_enter(&ds->ds_dir->dd_lock);
3437 mutex_enter(&ds->ds_lock);
3438 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
3439 unique = ds->ds_phys->ds_unique_bytes;
3440 delta = MAX(0, (int64_t)(effective_value - unique)) -
3441 MAX(0, (int64_t)(ds->ds_reserved - unique));
3442 ds->ds_reserved = effective_value;
3443 mutex_exit(&ds->ds_lock);
3445 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx);
3446 mutex_exit(&ds->ds_dir->dd_lock);
3448 spa_history_log_internal(LOG_DS_REFRESERV,
3449 ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu",
3450 (longlong_t)effective_value, ds->ds_object);
3454 dsl_dataset_set_reservation(const char *dsname, zprop_source_t source,
3455 uint64_t reservation)
3458 dsl_prop_setarg_t psa;
3461 dsl_prop_setarg_init_uint64(&psa, "refreservation", source,
3464 err = dsl_dataset_hold(dsname, FTAG, &ds);
3468 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
3469 dsl_dataset_set_reservation_check,
3470 dsl_dataset_set_reservation_sync, ds, &psa, 0);
3472 dsl_dataset_rele(ds, FTAG);
3476 typedef struct zfs_hold_cleanup_arg {
3479 char htag[MAXNAMELEN];
3480 } zfs_hold_cleanup_arg_t;
3483 dsl_dataset_user_release_onexit(void *arg)
3485 zfs_hold_cleanup_arg_t *ca = arg;
3487 (void) dsl_dataset_user_release_tmp(ca->dp, ca->dsobj, ca->htag,
3489 kmem_free(ca, sizeof (zfs_hold_cleanup_arg_t));
3493 dsl_register_onexit_hold_cleanup(dsl_dataset_t *ds, const char *htag,
3496 zfs_hold_cleanup_arg_t *ca;
3498 ca = kmem_alloc(sizeof (zfs_hold_cleanup_arg_t), KM_SLEEP);
3499 ca->dp = ds->ds_dir->dd_pool;
3500 ca->dsobj = ds->ds_object;
3501 (void) strlcpy(ca->htag, htag, sizeof (ca->htag));
3502 VERIFY3U(0, ==, zfs_onexit_add_cb(minor,
3503 dsl_dataset_user_release_onexit, ca, NULL));
3507 * If you add new checks here, you may need to add
3508 * additional checks to the "temporary" case in
3509 * snapshot_check() in dmu_objset.c.
3512 dsl_dataset_user_hold_check(void *arg1, void *arg2, dmu_tx_t *tx)
3514 dsl_dataset_t *ds = arg1;
3515 struct dsl_ds_holdarg *ha = arg2;
3516 char *htag = ha->htag;
3517 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3520 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS)
3523 if (!dsl_dataset_is_snapshot(ds))
3526 /* tags must be unique */
3527 mutex_enter(&ds->ds_lock);
3528 if (ds->ds_phys->ds_userrefs_obj) {
3529 error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj, htag,
3533 else if (error == ENOENT)
3536 mutex_exit(&ds->ds_lock);
3538 if (error == 0 && ha->temphold &&
3539 strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN)
3546 dsl_dataset_user_hold_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3548 dsl_dataset_t *ds = arg1;
3549 struct dsl_ds_holdarg *ha = arg2;
3550 char *htag = ha->htag;
3551 dsl_pool_t *dp = ds->ds_dir->dd_pool;
3552 objset_t *mos = dp->dp_meta_objset;
3553 uint64_t now = gethrestime_sec();
3556 mutex_enter(&ds->ds_lock);
3557 if (ds->ds_phys->ds_userrefs_obj == 0) {
3559 * This is the first user hold for this dataset. Create
3560 * the userrefs zap object.
3562 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3563 zapobj = ds->ds_phys->ds_userrefs_obj =
3564 zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx);
3566 zapobj = ds->ds_phys->ds_userrefs_obj;
3569 mutex_exit(&ds->ds_lock);
3571 VERIFY(0 == zap_add(mos, zapobj, htag, 8, 1, &now, tx));
3574 VERIFY(0 == dsl_pool_user_hold(dp, ds->ds_object,
3578 spa_history_log_internal(LOG_DS_USER_HOLD,
3579 dp->dp_spa, tx, "<%s> temp = %d dataset = %llu", htag,
3580 (int)ha->temphold, ds->ds_object);
3584 dsl_dataset_user_hold_one(const char *dsname, void *arg)
3586 struct dsl_ds_holdarg *ha = arg;
3591 /* alloc a buffer to hold dsname@snapname plus terminating NULL */
3592 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3593 error = dsl_dataset_hold(name, ha->dstg, &ds);
3596 ha->gotone = B_TRUE;
3597 dsl_sync_task_create(ha->dstg, dsl_dataset_user_hold_check,
3598 dsl_dataset_user_hold_sync, ds, ha, 0);
3599 } else if (error == ENOENT && ha->recursive) {
3602 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3608 dsl_dataset_user_hold_for_send(dsl_dataset_t *ds, char *htag,
3611 struct dsl_ds_holdarg *ha;
3614 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3616 ha->temphold = temphold;
3617 error = dsl_sync_task_do(ds->ds_dir->dd_pool,
3618 dsl_dataset_user_hold_check, dsl_dataset_user_hold_sync,
3620 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3626 dsl_dataset_user_hold(char *dsname, char *snapname, char *htag,
3627 boolean_t recursive, boolean_t temphold, int cleanup_fd)
3629 struct dsl_ds_holdarg *ha;
3630 dsl_sync_task_t *dst;
3635 if (cleanup_fd != -1) {
3636 /* Currently we only support cleanup-on-exit of tempholds. */
3639 error = zfs_onexit_fd_hold(cleanup_fd, &minor);
3644 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3646 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3648 error = spa_open(dsname, &spa, FTAG);
3650 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3651 if (cleanup_fd != -1)
3652 zfs_onexit_fd_rele(cleanup_fd);
3656 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
3658 ha->snapname = snapname;
3659 ha->recursive = recursive;
3660 ha->temphold = temphold;
3663 error = dmu_objset_find(dsname, dsl_dataset_user_hold_one,
3664 ha, DS_FIND_CHILDREN);
3666 error = dsl_dataset_user_hold_one(dsname, ha);
3669 error = dsl_sync_task_group_wait(ha->dstg);
3671 for (dst = list_head(&ha->dstg->dstg_tasks); dst;
3672 dst = list_next(&ha->dstg->dstg_tasks, dst)) {
3673 dsl_dataset_t *ds = dst->dst_arg1;
3676 dsl_dataset_name(ds, ha->failed);
3677 *strchr(ha->failed, '@') = '\0';
3678 } else if (error == 0 && minor != 0 && temphold) {
3680 * If this hold is to be released upon process exit,
3681 * register that action now.
3683 dsl_register_onexit_hold_cleanup(ds, htag, minor);
3685 dsl_dataset_rele(ds, ha->dstg);
3688 if (error == 0 && recursive && !ha->gotone)
3692 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed));
3694 dsl_sync_task_group_destroy(ha->dstg);
3696 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3697 spa_close(spa, FTAG);
3698 if (cleanup_fd != -1)
3699 zfs_onexit_fd_rele(cleanup_fd);
3703 struct dsl_ds_releasearg {
3706 boolean_t own; /* do we own or just hold ds? */
3710 dsl_dataset_release_might_destroy(dsl_dataset_t *ds, const char *htag,
3711 boolean_t *might_destroy)
3713 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3718 *might_destroy = B_FALSE;
3720 mutex_enter(&ds->ds_lock);
3721 zapobj = ds->ds_phys->ds_userrefs_obj;
3723 /* The tag can't possibly exist */
3724 mutex_exit(&ds->ds_lock);
3728 /* Make sure the tag exists */
3729 error = zap_lookup(mos, zapobj, htag, 8, 1, &tmp);
3731 mutex_exit(&ds->ds_lock);
3732 if (error == ENOENT)
3737 if (ds->ds_userrefs == 1 && ds->ds_phys->ds_num_children == 1 &&
3738 DS_IS_DEFER_DESTROY(ds))
3739 *might_destroy = B_TRUE;
3741 mutex_exit(&ds->ds_lock);
3746 dsl_dataset_user_release_check(void *arg1, void *tag, dmu_tx_t *tx)
3748 struct dsl_ds_releasearg *ra = arg1;
3749 dsl_dataset_t *ds = ra->ds;
3750 boolean_t might_destroy;
3753 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS)
3756 error = dsl_dataset_release_might_destroy(ds, ra->htag, &might_destroy);
3760 if (might_destroy) {
3761 struct dsl_ds_destroyarg dsda = {0};
3763 if (dmu_tx_is_syncing(tx)) {
3765 * If we're not prepared to remove the snapshot,
3766 * we can't allow the release to happen right now.
3772 dsda.releasing = B_TRUE;
3773 return (dsl_dataset_destroy_check(&dsda, tag, tx));
3780 dsl_dataset_user_release_sync(void *arg1, void *tag, dmu_tx_t *tx)
3782 struct dsl_ds_releasearg *ra = arg1;
3783 dsl_dataset_t *ds = ra->ds;
3784 dsl_pool_t *dp = ds->ds_dir->dd_pool;
3785 objset_t *mos = dp->dp_meta_objset;
3787 uint64_t dsobj = ds->ds_object;
3791 mutex_enter(&ds->ds_lock);
3793 refs = ds->ds_userrefs;
3794 mutex_exit(&ds->ds_lock);
3795 error = dsl_pool_user_release(dp, ds->ds_object, ra->htag, tx);
3796 VERIFY(error == 0 || error == ENOENT);
3797 zapobj = ds->ds_phys->ds_userrefs_obj;
3798 VERIFY(0 == zap_remove(mos, zapobj, ra->htag, tx));
3799 if (ds->ds_userrefs == 0 && ds->ds_phys->ds_num_children == 1 &&
3800 DS_IS_DEFER_DESTROY(ds)) {
3801 struct dsl_ds_destroyarg dsda = {0};
3805 dsda.releasing = B_TRUE;
3806 /* We already did the destroy_check */
3807 dsl_dataset_destroy_sync(&dsda, tag, tx);
3810 spa_history_log_internal(LOG_DS_USER_RELEASE,
3811 dp->dp_spa, tx, "<%s> %lld dataset = %llu",
3812 ra->htag, (longlong_t)refs, dsobj);
3816 dsl_dataset_user_release_one(const char *dsname, void *arg)
3818 struct dsl_ds_holdarg *ha = arg;
3819 struct dsl_ds_releasearg *ra;
3822 void *dtag = ha->dstg;
3824 boolean_t own = B_FALSE;
3825 boolean_t might_destroy;
3827 /* alloc a buffer to hold dsname@snapname, plus the terminating NULL */
3828 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3829 error = dsl_dataset_hold(name, dtag, &ds);
3831 if (error == ENOENT && ha->recursive)
3833 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3837 ha->gotone = B_TRUE;
3839 ASSERT(dsl_dataset_is_snapshot(ds));
3841 error = dsl_dataset_release_might_destroy(ds, ha->htag, &might_destroy);
3843 dsl_dataset_rele(ds, dtag);
3847 if (might_destroy) {
3849 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3850 error = zfs_unmount_snap(name, NULL);
3853 dsl_dataset_rele(ds, dtag);
3857 if (!dsl_dataset_tryown(ds, B_TRUE, dtag)) {
3858 dsl_dataset_rele(ds, dtag);
3862 dsl_dataset_make_exclusive(ds, dtag);
3866 ra = kmem_alloc(sizeof (struct dsl_ds_releasearg), KM_SLEEP);
3868 ra->htag = ha->htag;
3870 dsl_sync_task_create(ha->dstg, dsl_dataset_user_release_check,
3871 dsl_dataset_user_release_sync, ra, dtag, 0);
3877 dsl_dataset_user_release(char *dsname, char *snapname, char *htag,
3878 boolean_t recursive)
3880 struct dsl_ds_holdarg *ha;
3881 dsl_sync_task_t *dst;
3886 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3888 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3890 error = spa_open(dsname, &spa, FTAG);
3892 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3896 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
3898 ha->snapname = snapname;
3899 ha->recursive = recursive;
3901 error = dmu_objset_find(dsname, dsl_dataset_user_release_one,
3902 ha, DS_FIND_CHILDREN);
3904 error = dsl_dataset_user_release_one(dsname, ha);
3907 error = dsl_sync_task_group_wait(ha->dstg);
3909 for (dst = list_head(&ha->dstg->dstg_tasks); dst;
3910 dst = list_next(&ha->dstg->dstg_tasks, dst)) {
3911 struct dsl_ds_releasearg *ra = dst->dst_arg1;
3912 dsl_dataset_t *ds = ra->ds;
3915 dsl_dataset_name(ds, ha->failed);
3918 dsl_dataset_disown(ds, ha->dstg);
3920 dsl_dataset_rele(ds, ha->dstg);
3922 kmem_free(ra, sizeof (struct dsl_ds_releasearg));
3925 if (error == 0 && recursive && !ha->gotone)
3928 if (error && error != EBUSY)
3929 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed));
3931 dsl_sync_task_group_destroy(ha->dstg);
3932 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3933 spa_close(spa, FTAG);
3936 * We can get EBUSY if we were racing with deferred destroy and
3937 * dsl_dataset_user_release_check() hadn't done the necessary
3938 * open context setup. We can also get EBUSY if we're racing
3939 * with destroy and that thread is the ds_owner. Either way
3940 * the busy condition should be transient, and we should retry
3941 * the release operation.
3950 * Called at spa_load time (with retry == B_FALSE) to release a stale
3951 * temporary user hold. Also called by the onexit code (with retry == B_TRUE).
3954 dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, char *htag,
3964 rw_enter(&dp->dp_config_rwlock, RW_READER);
3965 error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds);
3966 rw_exit(&dp->dp_config_rwlock);
3969 namelen = dsl_dataset_namelen(ds)+1;
3970 name = kmem_alloc(namelen, KM_SLEEP);
3971 dsl_dataset_name(ds, name);
3972 dsl_dataset_rele(ds, FTAG);
3974 snap = strchr(name, '@');
3977 error = dsl_dataset_user_release(name, snap, htag, B_FALSE);
3978 kmem_free(name, namelen);
3981 * The object can't have been destroyed because we have a hold,
3982 * but it might have been renamed, resulting in ENOENT. Retry
3983 * if we've been requested to do so.
3985 * It would be nice if we could use the dsobj all the way
3986 * through and avoid ENOENT entirely. But we might need to
3987 * unmount the snapshot, and there's currently no way to lookup
3988 * a vfsp using a ZFS object id.
3990 } while ((error == ENOENT) && retry);
3996 dsl_dataset_get_holds(const char *dsname, nvlist_t **nvp)
4001 err = dsl_dataset_hold(dsname, FTAG, &ds);
4005 VERIFY(0 == nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP));
4006 if (ds->ds_phys->ds_userrefs_obj != 0) {
4007 zap_attribute_t *za;
4010 za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP);
4011 for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset,
4012 ds->ds_phys->ds_userrefs_obj);
4013 zap_cursor_retrieve(&zc, za) == 0;
4014 zap_cursor_advance(&zc)) {
4015 VERIFY(0 == nvlist_add_uint64(*nvp, za->za_name,
4016 za->za_first_integer));
4018 zap_cursor_fini(&zc);
4019 kmem_free(za, sizeof (zap_attribute_t));
4021 dsl_dataset_rele(ds, FTAG);
4026 * Note, this fuction is used as the callback for dmu_objset_find(). We
4027 * always return 0 so that we will continue to find and process
4028 * inconsistent datasets, even if we encounter an error trying to
4029 * process one of them.
4033 dsl_destroy_inconsistent(const char *dsname, void *arg)
4037 if (dsl_dataset_own(dsname, B_TRUE, FTAG, &ds) == 0) {
4038 if (DS_IS_INCONSISTENT(ds))
4039 (void) dsl_dataset_destroy(ds, FTAG, B_FALSE);
4041 dsl_dataset_disown(ds, FTAG);