1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2011 by Delphix. All rights reserved.
24 * Copyright (c) 2011 Pawel Jakub Dawidek <pawel@dawidek.net>.
25 * All rights reserved.
| 1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2011 by Delphix. All rights reserved.
24 * Copyright (c) 2011 Pawel Jakub Dawidek <pawel@dawidek.net>.
25 * All rights reserved.
|
| 26 * Portions Copyright 2011 Martin Matuska <mm@FreeBSd.org>
|
26 */
27
28#include <sys/dmu_objset.h>
29#include <sys/dsl_dataset.h>
30#include <sys/dsl_dir.h>
31#include <sys/dsl_prop.h>
32#include <sys/dsl_synctask.h>
33#include <sys/dmu_traverse.h>
34#include <sys/dmu_tx.h>
35#include <sys/arc.h>
36#include <sys/zio.h>
37#include <sys/zap.h>
38#include <sys/unique.h>
39#include <sys/zfs_context.h>
40#include <sys/zfs_ioctl.h>
41#include <sys/spa.h>
42#include <sys/zfs_znode.h>
43#include <sys/zfs_onexit.h>
44#include <sys/zvol.h>
45#include <sys/dsl_scan.h>
46#include <sys/dsl_deadlist.h>
47
48static char *dsl_reaper = "the grim reaper";
49
50static dsl_checkfunc_t dsl_dataset_destroy_begin_check;
51static dsl_syncfunc_t dsl_dataset_destroy_begin_sync;
52static dsl_syncfunc_t dsl_dataset_set_reservation_sync;
53
54#define SWITCH64(x, y) \
55 { \
56 uint64_t __tmp = (x); \
57 (x) = (y); \
58 (y) = __tmp; \
59 }
60
61#define DS_REF_MAX (1ULL << 62)
62
63#define DSL_DEADLIST_BLOCKSIZE SPA_MAXBLOCKSIZE
64
65#define DSL_DATASET_IS_DESTROYED(ds) ((ds)->ds_owner == dsl_reaper)
66
67
68/*
69 * Figure out how much of this delta should be propogated to the dsl_dir
70 * layer. If there's a refreservation, that space has already been
71 * partially accounted for in our ancestors.
72 */
73static int64_t
74parent_delta(dsl_dataset_t *ds, int64_t delta)
75{
76 uint64_t old_bytes, new_bytes;
77
78 if (ds->ds_reserved == 0)
79 return (delta);
80
81 old_bytes = MAX(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
82 new_bytes = MAX(ds->ds_phys->ds_unique_bytes + delta, ds->ds_reserved);
83
84 ASSERT3U(ABS((int64_t)(new_bytes - old_bytes)), <=, ABS(delta));
85 return (new_bytes - old_bytes);
86}
87
88void
89dsl_dataset_block_born(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx)
90{
91 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
92 int compressed = BP_GET_PSIZE(bp);
93 int uncompressed = BP_GET_UCSIZE(bp);
94 int64_t delta;
95
96 dprintf_bp(bp, "ds=%p", ds);
97
98 ASSERT(dmu_tx_is_syncing(tx));
99 /* It could have been compressed away to nothing */
100 if (BP_IS_HOLE(bp))
101 return;
102 ASSERT(BP_GET_TYPE(bp) != DMU_OT_NONE);
103 ASSERT3U(BP_GET_TYPE(bp), <, DMU_OT_NUMTYPES);
104 if (ds == NULL) {
105 /*
106 * Account for the meta-objset space in its placeholder
107 * dsl_dir.
108 */
109 ASSERT3U(compressed, ==, uncompressed); /* it's all metadata */
110 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD,
111 used, compressed, uncompressed, tx);
112 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx);
113 return;
114 }
115 dmu_buf_will_dirty(ds->ds_dbuf, tx);
116
117 mutex_enter(&ds->ds_dir->dd_lock);
118 mutex_enter(&ds->ds_lock);
119 delta = parent_delta(ds, used);
120 ds->ds_phys->ds_used_bytes += used;
121 ds->ds_phys->ds_compressed_bytes += compressed;
122 ds->ds_phys->ds_uncompressed_bytes += uncompressed;
123 ds->ds_phys->ds_unique_bytes += used;
124 mutex_exit(&ds->ds_lock);
125 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta,
126 compressed, uncompressed, tx);
127 dsl_dir_transfer_space(ds->ds_dir, used - delta,
128 DD_USED_REFRSRV, DD_USED_HEAD, tx);
129 mutex_exit(&ds->ds_dir->dd_lock);
130}
131
132int
133dsl_dataset_block_kill(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx,
134 boolean_t async)
135{
136 if (BP_IS_HOLE(bp))
137 return (0);
138
139 ASSERT(dmu_tx_is_syncing(tx));
140 ASSERT(bp->blk_birth <= tx->tx_txg);
141
142 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
143 int compressed = BP_GET_PSIZE(bp);
144 int uncompressed = BP_GET_UCSIZE(bp);
145
146 ASSERT(used > 0);
147 if (ds == NULL) {
148 /*
149 * Account for the meta-objset space in its placeholder
150 * dataset.
151 */
152 dsl_free(tx->tx_pool, tx->tx_txg, bp);
153
154 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD,
155 -used, -compressed, -uncompressed, tx);
156 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx);
157 return (used);
158 }
159 ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool);
160
161 ASSERT(!dsl_dataset_is_snapshot(ds));
162 dmu_buf_will_dirty(ds->ds_dbuf, tx);
163
164 if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) {
165 int64_t delta;
166
167 dprintf_bp(bp, "freeing ds=%llu", ds->ds_object);
168 dsl_free(tx->tx_pool, tx->tx_txg, bp);
169
170 mutex_enter(&ds->ds_dir->dd_lock);
171 mutex_enter(&ds->ds_lock);
172 ASSERT(ds->ds_phys->ds_unique_bytes >= used ||
173 !DS_UNIQUE_IS_ACCURATE(ds));
174 delta = parent_delta(ds, -used);
175 ds->ds_phys->ds_unique_bytes -= used;
176 mutex_exit(&ds->ds_lock);
177 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
178 delta, -compressed, -uncompressed, tx);
179 dsl_dir_transfer_space(ds->ds_dir, -used - delta,
180 DD_USED_REFRSRV, DD_USED_HEAD, tx);
181 mutex_exit(&ds->ds_dir->dd_lock);
182 } else {
183 dprintf_bp(bp, "putting on dead list: %s", "");
184 if (async) {
185 /*
186 * We are here as part of zio's write done callback,
187 * which means we're a zio interrupt thread. We can't
188 * call dsl_deadlist_insert() now because it may block
189 * waiting for I/O. Instead, put bp on the deferred
190 * queue and let dsl_pool_sync() finish the job.
191 */
192 bplist_append(&ds->ds_pending_deadlist, bp);
193 } else {
194 dsl_deadlist_insert(&ds->ds_deadlist, bp, tx);
195 }
196 ASSERT3U(ds->ds_prev->ds_object, ==,
197 ds->ds_phys->ds_prev_snap_obj);
198 ASSERT(ds->ds_prev->ds_phys->ds_num_children > 0);
199 /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */
200 if (ds->ds_prev->ds_phys->ds_next_snap_obj ==
201 ds->ds_object && bp->blk_birth >
202 ds->ds_prev->ds_phys->ds_prev_snap_txg) {
203 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
204 mutex_enter(&ds->ds_prev->ds_lock);
205 ds->ds_prev->ds_phys->ds_unique_bytes += used;
206 mutex_exit(&ds->ds_prev->ds_lock);
207 }
208 if (bp->blk_birth > ds->ds_dir->dd_origin_txg) {
209 dsl_dir_transfer_space(ds->ds_dir, used,
210 DD_USED_HEAD, DD_USED_SNAP, tx);
211 }
212 }
213 mutex_enter(&ds->ds_lock);
214 ASSERT3U(ds->ds_phys->ds_used_bytes, >=, used);
215 ds->ds_phys->ds_used_bytes -= used;
216 ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed);
217 ds->ds_phys->ds_compressed_bytes -= compressed;
218 ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed);
219 ds->ds_phys->ds_uncompressed_bytes -= uncompressed;
220 mutex_exit(&ds->ds_lock);
221
222 return (used);
223}
224
225uint64_t
226dsl_dataset_prev_snap_txg(dsl_dataset_t *ds)
227{
228 uint64_t trysnap = 0;
229
230 if (ds == NULL)
231 return (0);
232 /*
233 * The snapshot creation could fail, but that would cause an
234 * incorrect FALSE return, which would only result in an
235 * overestimation of the amount of space that an operation would
236 * consume, which is OK.
237 *
238 * There's also a small window where we could miss a pending
239 * snapshot, because we could set the sync task in the quiescing
240 * phase. So this should only be used as a guess.
241 */
242 if (ds->ds_trysnap_txg >
243 spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa))
244 trysnap = ds->ds_trysnap_txg;
245 return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap));
246}
247
248boolean_t
249dsl_dataset_block_freeable(dsl_dataset_t *ds, const blkptr_t *bp,
250 uint64_t blk_birth)
251{
252 if (blk_birth <= dsl_dataset_prev_snap_txg(ds))
253 return (B_FALSE);
254
255 ddt_prefetch(dsl_dataset_get_spa(ds), bp);
256
257 return (B_TRUE);
258}
259
260/* ARGSUSED */
261static void
262dsl_dataset_evict(dmu_buf_t *db, void *dsv)
263{
264 dsl_dataset_t *ds = dsv;
265
266 ASSERT(ds->ds_owner == NULL || DSL_DATASET_IS_DESTROYED(ds));
267
268 unique_remove(ds->ds_fsid_guid);
269
270 if (ds->ds_objset != NULL)
271 dmu_objset_evict(ds->ds_objset);
272
273 if (ds->ds_prev) {
274 dsl_dataset_drop_ref(ds->ds_prev, ds);
275 ds->ds_prev = NULL;
276 }
277
278 bplist_destroy(&ds->ds_pending_deadlist);
279 if (db != NULL) {
280 dsl_deadlist_close(&ds->ds_deadlist);
281 } else {
282 ASSERT(ds->ds_deadlist.dl_dbuf == NULL);
283 ASSERT(!ds->ds_deadlist.dl_oldfmt);
284 }
285 if (ds->ds_dir)
286 dsl_dir_close(ds->ds_dir, ds);
287
288 ASSERT(!list_link_active(&ds->ds_synced_link));
289
290 if (mutex_owned(&ds->ds_lock))
291 mutex_exit(&ds->ds_lock);
292 mutex_destroy(&ds->ds_lock);
293 mutex_destroy(&ds->ds_recvlock);
294 if (mutex_owned(&ds->ds_opening_lock))
295 mutex_exit(&ds->ds_opening_lock);
296 mutex_destroy(&ds->ds_opening_lock);
297 rw_destroy(&ds->ds_rwlock);
298 cv_destroy(&ds->ds_exclusive_cv);
299
300 kmem_free(ds, sizeof (dsl_dataset_t));
301}
302
303static int
304dsl_dataset_get_snapname(dsl_dataset_t *ds)
305{
306 dsl_dataset_phys_t *headphys;
307 int err;
308 dmu_buf_t *headdbuf;
309 dsl_pool_t *dp = ds->ds_dir->dd_pool;
310 objset_t *mos = dp->dp_meta_objset;
311
312 if (ds->ds_snapname[0])
313 return (0);
314 if (ds->ds_phys->ds_next_snap_obj == 0)
315 return (0);
316
317 err = dmu_bonus_hold(mos, ds->ds_dir->dd_phys->dd_head_dataset_obj,
318 FTAG, &headdbuf);
319 if (err)
320 return (err);
321 headphys = headdbuf->db_data;
322 err = zap_value_search(dp->dp_meta_objset,
323 headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname);
324 dmu_buf_rele(headdbuf, FTAG);
325 return (err);
326}
327
328static int
329dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name, uint64_t *value)
330{
331 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
332 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
333 matchtype_t mt;
334 int err;
335
336 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
337 mt = MT_FIRST;
338 else
339 mt = MT_EXACT;
340
341 err = zap_lookup_norm(mos, snapobj, name, 8, 1,
342 value, mt, NULL, 0, NULL);
343 if (err == ENOTSUP && mt == MT_FIRST)
344 err = zap_lookup(mos, snapobj, name, 8, 1, value);
345 return (err);
346}
347
348static int
349dsl_dataset_snap_remove(dsl_dataset_t *ds, char *name, dmu_tx_t *tx)
350{
351 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
352 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
353 matchtype_t mt;
354 int err;
355
356 dsl_dir_snap_cmtime_update(ds->ds_dir);
357
358 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
359 mt = MT_FIRST;
360 else
361 mt = MT_EXACT;
362
363 err = zap_remove_norm(mos, snapobj, name, mt, tx);
364 if (err == ENOTSUP && mt == MT_FIRST)
365 err = zap_remove(mos, snapobj, name, tx);
366 return (err);
367}
368
369static int
370dsl_dataset_get_ref(dsl_pool_t *dp, uint64_t dsobj, void *tag,
371 dsl_dataset_t **dsp)
372{
373 objset_t *mos = dp->dp_meta_objset;
374 dmu_buf_t *dbuf;
375 dsl_dataset_t *ds;
376 int err;
377 dmu_object_info_t doi;
378
379 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) ||
380 dsl_pool_sync_context(dp));
381
382 err = dmu_bonus_hold(mos, dsobj, tag, &dbuf);
383 if (err)
384 return (err);
385
386 /* Make sure dsobj has the correct object type. */
387 dmu_object_info_from_db(dbuf, &doi);
388 if (doi.doi_type != DMU_OT_DSL_DATASET)
389 return (EINVAL);
390
391 ds = dmu_buf_get_user(dbuf);
392 if (ds == NULL) {
393 dsl_dataset_t *winner;
394
395 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP);
396 ds->ds_dbuf = dbuf;
397 ds->ds_object = dsobj;
398 ds->ds_phys = dbuf->db_data;
399
400 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL);
401 mutex_init(&ds->ds_recvlock, NULL, MUTEX_DEFAULT, NULL);
402 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL);
403 rw_init(&ds->ds_rwlock, 0, 0, 0);
404 cv_init(&ds->ds_exclusive_cv, NULL, CV_DEFAULT, NULL);
405
406 bplist_create(&ds->ds_pending_deadlist);
407 dsl_deadlist_open(&ds->ds_deadlist,
408 mos, ds->ds_phys->ds_deadlist_obj);
409
410 if (err == 0) {
411 err = dsl_dir_open_obj(dp,
412 ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir);
413 }
414 if (err) {
415 mutex_destroy(&ds->ds_lock);
416 mutex_destroy(&ds->ds_recvlock);
417 mutex_destroy(&ds->ds_opening_lock);
418 rw_destroy(&ds->ds_rwlock);
419 cv_destroy(&ds->ds_exclusive_cv);
420 bplist_destroy(&ds->ds_pending_deadlist);
421 dsl_deadlist_close(&ds->ds_deadlist);
422 kmem_free(ds, sizeof (dsl_dataset_t));
423 dmu_buf_rele(dbuf, tag);
424 return (err);
425 }
426
427 if (!dsl_dataset_is_snapshot(ds)) {
428 ds->ds_snapname[0] = '\0';
429 if (ds->ds_phys->ds_prev_snap_obj) {
430 err = dsl_dataset_get_ref(dp,
431 ds->ds_phys->ds_prev_snap_obj,
432 ds, &ds->ds_prev);
433 }
434 } else {
435 if (zfs_flags & ZFS_DEBUG_SNAPNAMES)
436 err = dsl_dataset_get_snapname(ds);
437 if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) {
438 err = zap_count(
439 ds->ds_dir->dd_pool->dp_meta_objset,
440 ds->ds_phys->ds_userrefs_obj,
441 &ds->ds_userrefs);
442 }
443 }
444
445 if (err == 0 && !dsl_dataset_is_snapshot(ds)) {
446 /*
447 * In sync context, we're called with either no lock
448 * or with the write lock. If we're not syncing,
449 * we're always called with the read lock held.
450 */
451 boolean_t need_lock =
452 !RW_WRITE_HELD(&dp->dp_config_rwlock) &&
453 dsl_pool_sync_context(dp);
454
455 if (need_lock)
456 rw_enter(&dp->dp_config_rwlock, RW_READER);
457
458 err = dsl_prop_get_ds(ds,
459 "refreservation", sizeof (uint64_t), 1,
460 &ds->ds_reserved, NULL);
461 if (err == 0) {
462 err = dsl_prop_get_ds(ds,
463 "refquota", sizeof (uint64_t), 1,
464 &ds->ds_quota, NULL);
465 }
466
467 if (need_lock)
468 rw_exit(&dp->dp_config_rwlock);
469 } else {
470 ds->ds_reserved = ds->ds_quota = 0;
471 }
472
473 if (err == 0) {
474 winner = dmu_buf_set_user_ie(dbuf, ds, &ds->ds_phys,
475 dsl_dataset_evict);
476 }
477 if (err || winner) {
478 bplist_destroy(&ds->ds_pending_deadlist);
479 dsl_deadlist_close(&ds->ds_deadlist);
480 if (ds->ds_prev)
481 dsl_dataset_drop_ref(ds->ds_prev, ds);
482 dsl_dir_close(ds->ds_dir, ds);
483 mutex_destroy(&ds->ds_lock);
484 mutex_destroy(&ds->ds_recvlock);
485 mutex_destroy(&ds->ds_opening_lock);
486 rw_destroy(&ds->ds_rwlock);
487 cv_destroy(&ds->ds_exclusive_cv);
488 kmem_free(ds, sizeof (dsl_dataset_t));
489 if (err) {
490 dmu_buf_rele(dbuf, tag);
491 return (err);
492 }
493 ds = winner;
494 } else {
495 ds->ds_fsid_guid =
496 unique_insert(ds->ds_phys->ds_fsid_guid);
497 }
498 }
499 ASSERT3P(ds->ds_dbuf, ==, dbuf);
500 ASSERT3P(ds->ds_phys, ==, dbuf->db_data);
501 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 ||
502 spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN ||
503 dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap);
504 mutex_enter(&ds->ds_lock);
505 if (!dsl_pool_sync_context(dp) && DSL_DATASET_IS_DESTROYED(ds)) {
506 mutex_exit(&ds->ds_lock);
507 dmu_buf_rele(ds->ds_dbuf, tag);
508 return (ENOENT);
509 }
510 mutex_exit(&ds->ds_lock);
511 *dsp = ds;
512 return (0);
513}
514
515static int
516dsl_dataset_hold_ref(dsl_dataset_t *ds, void *tag)
517{
518 dsl_pool_t *dp = ds->ds_dir->dd_pool;
519
520 /*
521 * In syncing context we don't want the rwlock lock: there
522 * may be an existing writer waiting for sync phase to
523 * finish. We don't need to worry about such writers, since
524 * sync phase is single-threaded, so the writer can't be
525 * doing anything while we are active.
526 */
527 if (dsl_pool_sync_context(dp)) {
528 ASSERT(!DSL_DATASET_IS_DESTROYED(ds));
529 return (0);
530 }
531
532 /*
533 * Normal users will hold the ds_rwlock as a READER until they
534 * are finished (i.e., call dsl_dataset_rele()). "Owners" will
535 * drop their READER lock after they set the ds_owner field.
536 *
537 * If the dataset is being destroyed, the destroy thread will
538 * obtain a WRITER lock for exclusive access after it's done its
539 * open-context work and then change the ds_owner to
540 * dsl_reaper once destruction is assured. So threads
541 * may block here temporarily, until the "destructability" of
542 * the dataset is determined.
543 */
544 ASSERT(!RW_WRITE_HELD(&dp->dp_config_rwlock));
545 mutex_enter(&ds->ds_lock);
546 while (!rw_tryenter(&ds->ds_rwlock, RW_READER)) {
547 rw_exit(&dp->dp_config_rwlock);
548 cv_wait(&ds->ds_exclusive_cv, &ds->ds_lock);
549 if (DSL_DATASET_IS_DESTROYED(ds)) {
550 mutex_exit(&ds->ds_lock);
551 dsl_dataset_drop_ref(ds, tag);
552 rw_enter(&dp->dp_config_rwlock, RW_READER);
553 return (ENOENT);
554 }
555 /*
556 * The dp_config_rwlock lives above the ds_lock. And
557 * we need to check DSL_DATASET_IS_DESTROYED() while
558 * holding the ds_lock, so we have to drop and reacquire
559 * the ds_lock here.
560 */
561 mutex_exit(&ds->ds_lock);
562 rw_enter(&dp->dp_config_rwlock, RW_READER);
563 mutex_enter(&ds->ds_lock);
564 }
565 mutex_exit(&ds->ds_lock);
566 return (0);
567}
568
569int
570dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag,
571 dsl_dataset_t **dsp)
572{
573 int err = dsl_dataset_get_ref(dp, dsobj, tag, dsp);
574
575 if (err)
576 return (err);
577 return (dsl_dataset_hold_ref(*dsp, tag));
578}
579
580int
581dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj, boolean_t inconsistentok,
582 void *tag, dsl_dataset_t **dsp)
583{
584 int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp);
585 if (err)
586 return (err);
587 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) {
588 dsl_dataset_rele(*dsp, tag);
589 *dsp = NULL;
590 return (EBUSY);
591 }
592 return (0);
593}
594
595int
596dsl_dataset_hold(const char *name, void *tag, dsl_dataset_t **dsp)
597{
598 dsl_dir_t *dd;
599 dsl_pool_t *dp;
600 const char *snapname;
601 uint64_t obj;
602 int err = 0;
603
604 err = dsl_dir_open_spa(NULL, name, FTAG, &dd, &snapname);
605 if (err)
606 return (err);
607
608 dp = dd->dd_pool;
609 obj = dd->dd_phys->dd_head_dataset_obj;
610 rw_enter(&dp->dp_config_rwlock, RW_READER);
611 if (obj)
612 err = dsl_dataset_get_ref(dp, obj, tag, dsp);
613 else
614 err = ENOENT;
615 if (err)
616 goto out;
617
618 err = dsl_dataset_hold_ref(*dsp, tag);
619
620 /* we may be looking for a snapshot */
621 if (err == 0 && snapname != NULL) {
622 dsl_dataset_t *ds = NULL;
623
624 if (*snapname++ != '@') {
625 dsl_dataset_rele(*dsp, tag);
626 err = ENOENT;
627 goto out;
628 }
629
630 dprintf("looking for snapshot '%s'\n", snapname);
631 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj);
632 if (err == 0)
633 err = dsl_dataset_get_ref(dp, obj, tag, &ds);
634 dsl_dataset_rele(*dsp, tag);
635
636 ASSERT3U((err == 0), ==, (ds != NULL));
637
638 if (ds) {
639 mutex_enter(&ds->ds_lock);
640 if (ds->ds_snapname[0] == 0)
641 (void) strlcpy(ds->ds_snapname, snapname,
642 sizeof (ds->ds_snapname));
643 mutex_exit(&ds->ds_lock);
644 err = dsl_dataset_hold_ref(ds, tag);
645 *dsp = err ? NULL : ds;
646 }
647 }
648out:
649 rw_exit(&dp->dp_config_rwlock);
650 dsl_dir_close(dd, FTAG);
651 return (err);
652}
653
654int
655dsl_dataset_own(const char *name, boolean_t inconsistentok,
656 void *tag, dsl_dataset_t **dsp)
657{
658 int err = dsl_dataset_hold(name, tag, dsp);
659 if (err)
660 return (err);
661 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) {
662 dsl_dataset_rele(*dsp, tag);
663 return (EBUSY);
664 }
665 return (0);
666}
667
668void
669dsl_dataset_name(dsl_dataset_t *ds, char *name)
670{
671 if (ds == NULL) {
672 (void) strcpy(name, "mos");
673 } else {
674 dsl_dir_name(ds->ds_dir, name);
675 VERIFY(0 == dsl_dataset_get_snapname(ds));
676 if (ds->ds_snapname[0]) {
677 (void) strcat(name, "@");
678 /*
679 * We use a "recursive" mutex so that we
680 * can call dprintf_ds() with ds_lock held.
681 */
682 if (!MUTEX_HELD(&ds->ds_lock)) {
683 mutex_enter(&ds->ds_lock);
684 (void) strcat(name, ds->ds_snapname);
685 mutex_exit(&ds->ds_lock);
686 } else {
687 (void) strcat(name, ds->ds_snapname);
688 }
689 }
690 }
691}
692
693static int
694dsl_dataset_namelen(dsl_dataset_t *ds)
695{
696 int result;
697
698 if (ds == NULL) {
699 result = 3; /* "mos" */
700 } else {
701 result = dsl_dir_namelen(ds->ds_dir);
702 VERIFY(0 == dsl_dataset_get_snapname(ds));
703 if (ds->ds_snapname[0]) {
704 ++result; /* adding one for the @-sign */
705 if (!MUTEX_HELD(&ds->ds_lock)) {
706 mutex_enter(&ds->ds_lock);
707 result += strlen(ds->ds_snapname);
708 mutex_exit(&ds->ds_lock);
709 } else {
710 result += strlen(ds->ds_snapname);
711 }
712 }
713 }
714
715 return (result);
716}
717
718void
719dsl_dataset_drop_ref(dsl_dataset_t *ds, void *tag)
720{
721 dmu_buf_rele(ds->ds_dbuf, tag);
722}
723
724void
725dsl_dataset_rele(dsl_dataset_t *ds, void *tag)
726{
727 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) {
728 rw_exit(&ds->ds_rwlock);
729 }
730 dsl_dataset_drop_ref(ds, tag);
731}
732
733void
734dsl_dataset_disown(dsl_dataset_t *ds, void *tag)
735{
736 ASSERT((ds->ds_owner == tag && ds->ds_dbuf) ||
737 (DSL_DATASET_IS_DESTROYED(ds) && ds->ds_dbuf == NULL));
738
739 mutex_enter(&ds->ds_lock);
740 ds->ds_owner = NULL;
741 if (RW_WRITE_HELD(&ds->ds_rwlock)) {
742 rw_exit(&ds->ds_rwlock);
743 cv_broadcast(&ds->ds_exclusive_cv);
744 }
745 mutex_exit(&ds->ds_lock);
746 if (ds->ds_dbuf)
747 dsl_dataset_drop_ref(ds, tag);
748 else
749 dsl_dataset_evict(NULL, ds);
750}
751
752boolean_t
753dsl_dataset_tryown(dsl_dataset_t *ds, boolean_t inconsistentok, void *tag)
754{
755 boolean_t gotit = FALSE;
756
757 mutex_enter(&ds->ds_lock);
758 if (ds->ds_owner == NULL &&
759 (!DS_IS_INCONSISTENT(ds) || inconsistentok)) {
760 ds->ds_owner = tag;
761 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool))
762 rw_exit(&ds->ds_rwlock);
763 gotit = TRUE;
764 }
765 mutex_exit(&ds->ds_lock);
766 return (gotit);
767}
768
769void
770dsl_dataset_make_exclusive(dsl_dataset_t *ds, void *owner)
771{
772 ASSERT3P(owner, ==, ds->ds_owner);
773 if (!RW_WRITE_HELD(&ds->ds_rwlock))
774 rw_enter(&ds->ds_rwlock, RW_WRITER);
775}
776
777uint64_t
778dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin,
779 uint64_t flags, dmu_tx_t *tx)
780{
781 dsl_pool_t *dp = dd->dd_pool;
782 dmu_buf_t *dbuf;
783 dsl_dataset_phys_t *dsphys;
784 uint64_t dsobj;
785 objset_t *mos = dp->dp_meta_objset;
786
787 if (origin == NULL)
788 origin = dp->dp_origin_snap;
789
790 ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp);
791 ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0);
792 ASSERT(dmu_tx_is_syncing(tx));
793 ASSERT(dd->dd_phys->dd_head_dataset_obj == 0);
794
795 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
796 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
797 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
798 dmu_buf_will_dirty(dbuf, tx);
799 dsphys = dbuf->db_data;
800 bzero(dsphys, sizeof (dsl_dataset_phys_t));
801 dsphys->ds_dir_obj = dd->dd_object;
802 dsphys->ds_flags = flags;
803 dsphys->ds_fsid_guid = unique_create();
804 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
805 sizeof (dsphys->ds_guid));
806 dsphys->ds_snapnames_zapobj =
807 zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP,
808 DMU_OT_NONE, 0, tx);
809 dsphys->ds_creation_time = gethrestime_sec();
810 dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg;
811
812 if (origin == NULL) {
813 dsphys->ds_deadlist_obj = dsl_deadlist_alloc(mos, tx);
814 } else {
815 dsl_dataset_t *ohds;
816
817 dsphys->ds_prev_snap_obj = origin->ds_object;
818 dsphys->ds_prev_snap_txg =
819 origin->ds_phys->ds_creation_txg;
820 dsphys->ds_used_bytes =
821 origin->ds_phys->ds_used_bytes;
822 dsphys->ds_compressed_bytes =
823 origin->ds_phys->ds_compressed_bytes;
824 dsphys->ds_uncompressed_bytes =
825 origin->ds_phys->ds_uncompressed_bytes;
826 dsphys->ds_bp = origin->ds_phys->ds_bp;
827 dsphys->ds_flags |= origin->ds_phys->ds_flags;
828
829 dmu_buf_will_dirty(origin->ds_dbuf, tx);
830 origin->ds_phys->ds_num_children++;
831
832 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
833 origin->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ohds));
834 dsphys->ds_deadlist_obj = dsl_deadlist_clone(&ohds->ds_deadlist,
835 dsphys->ds_prev_snap_txg, dsphys->ds_prev_snap_obj, tx);
836 dsl_dataset_rele(ohds, FTAG);
837
838 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) {
839 if (origin->ds_phys->ds_next_clones_obj == 0) {
840 origin->ds_phys->ds_next_clones_obj =
841 zap_create(mos,
842 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx);
843 }
844 VERIFY(0 == zap_add_int(mos,
845 origin->ds_phys->ds_next_clones_obj,
846 dsobj, tx));
847 }
848
849 dmu_buf_will_dirty(dd->dd_dbuf, tx);
850 dd->dd_phys->dd_origin_obj = origin->ds_object;
851 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
852 if (origin->ds_dir->dd_phys->dd_clones == 0) {
853 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx);
854 origin->ds_dir->dd_phys->dd_clones =
855 zap_create(mos,
856 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
857 }
858 VERIFY3U(0, ==, zap_add_int(mos,
859 origin->ds_dir->dd_phys->dd_clones, dsobj, tx));
860 }
861 }
862
863 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
864 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
865
866 dmu_buf_rele(dbuf, FTAG);
867
868 dmu_buf_will_dirty(dd->dd_dbuf, tx);
869 dd->dd_phys->dd_head_dataset_obj = dsobj;
870
871 return (dsobj);
872}
873
874uint64_t
875dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname,
876 dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx)
877{
878 dsl_pool_t *dp = pdd->dd_pool;
879 uint64_t dsobj, ddobj;
880 dsl_dir_t *dd;
881
882 ASSERT(lastname[0] != '@');
883
884 ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx);
885 VERIFY(0 == dsl_dir_open_obj(dp, ddobj, lastname, FTAG, &dd));
886
887 dsobj = dsl_dataset_create_sync_dd(dd, origin, flags, tx);
888
889 dsl_deleg_set_create_perms(dd, tx, cr);
890
891 dsl_dir_close(dd, FTAG);
892
893 /*
894 * If we are creating a clone, make sure we zero out any stale
895 * data from the origin snapshots zil header.
896 */
897 if (origin != NULL) {
898 dsl_dataset_t *ds;
899 objset_t *os;
900
901 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
902 VERIFY3U(0, ==, dmu_objset_from_ds(ds, &os));
903 bzero(&os->os_zil_header, sizeof (os->os_zil_header));
904 dsl_dataset_dirty(ds, tx);
905 dsl_dataset_rele(ds, FTAG);
906 }
907
908 return (dsobj);
909}
910
| 27 */
28
29#include <sys/dmu_objset.h>
30#include <sys/dsl_dataset.h>
31#include <sys/dsl_dir.h>
32#include <sys/dsl_prop.h>
33#include <sys/dsl_synctask.h>
34#include <sys/dmu_traverse.h>
35#include <sys/dmu_tx.h>
36#include <sys/arc.h>
37#include <sys/zio.h>
38#include <sys/zap.h>
39#include <sys/unique.h>
40#include <sys/zfs_context.h>
41#include <sys/zfs_ioctl.h>
42#include <sys/spa.h>
43#include <sys/zfs_znode.h>
44#include <sys/zfs_onexit.h>
45#include <sys/zvol.h>
46#include <sys/dsl_scan.h>
47#include <sys/dsl_deadlist.h>
48
49static char *dsl_reaper = "the grim reaper";
50
51static dsl_checkfunc_t dsl_dataset_destroy_begin_check;
52static dsl_syncfunc_t dsl_dataset_destroy_begin_sync;
53static dsl_syncfunc_t dsl_dataset_set_reservation_sync;
54
55#define SWITCH64(x, y) \
56 { \
57 uint64_t __tmp = (x); \
58 (x) = (y); \
59 (y) = __tmp; \
60 }
61
62#define DS_REF_MAX (1ULL << 62)
63
64#define DSL_DEADLIST_BLOCKSIZE SPA_MAXBLOCKSIZE
65
66#define DSL_DATASET_IS_DESTROYED(ds) ((ds)->ds_owner == dsl_reaper)
67
68
69/*
70 * Figure out how much of this delta should be propogated to the dsl_dir
71 * layer. If there's a refreservation, that space has already been
72 * partially accounted for in our ancestors.
73 */
74static int64_t
75parent_delta(dsl_dataset_t *ds, int64_t delta)
76{
77 uint64_t old_bytes, new_bytes;
78
79 if (ds->ds_reserved == 0)
80 return (delta);
81
82 old_bytes = MAX(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
83 new_bytes = MAX(ds->ds_phys->ds_unique_bytes + delta, ds->ds_reserved);
84
85 ASSERT3U(ABS((int64_t)(new_bytes - old_bytes)), <=, ABS(delta));
86 return (new_bytes - old_bytes);
87}
88
89void
90dsl_dataset_block_born(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx)
91{
92 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
93 int compressed = BP_GET_PSIZE(bp);
94 int uncompressed = BP_GET_UCSIZE(bp);
95 int64_t delta;
96
97 dprintf_bp(bp, "ds=%p", ds);
98
99 ASSERT(dmu_tx_is_syncing(tx));
100 /* It could have been compressed away to nothing */
101 if (BP_IS_HOLE(bp))
102 return;
103 ASSERT(BP_GET_TYPE(bp) != DMU_OT_NONE);
104 ASSERT3U(BP_GET_TYPE(bp), <, DMU_OT_NUMTYPES);
105 if (ds == NULL) {
106 /*
107 * Account for the meta-objset space in its placeholder
108 * dsl_dir.
109 */
110 ASSERT3U(compressed, ==, uncompressed); /* it's all metadata */
111 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD,
112 used, compressed, uncompressed, tx);
113 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx);
114 return;
115 }
116 dmu_buf_will_dirty(ds->ds_dbuf, tx);
117
118 mutex_enter(&ds->ds_dir->dd_lock);
119 mutex_enter(&ds->ds_lock);
120 delta = parent_delta(ds, used);
121 ds->ds_phys->ds_used_bytes += used;
122 ds->ds_phys->ds_compressed_bytes += compressed;
123 ds->ds_phys->ds_uncompressed_bytes += uncompressed;
124 ds->ds_phys->ds_unique_bytes += used;
125 mutex_exit(&ds->ds_lock);
126 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta,
127 compressed, uncompressed, tx);
128 dsl_dir_transfer_space(ds->ds_dir, used - delta,
129 DD_USED_REFRSRV, DD_USED_HEAD, tx);
130 mutex_exit(&ds->ds_dir->dd_lock);
131}
132
133int
134dsl_dataset_block_kill(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx,
135 boolean_t async)
136{
137 if (BP_IS_HOLE(bp))
138 return (0);
139
140 ASSERT(dmu_tx_is_syncing(tx));
141 ASSERT(bp->blk_birth <= tx->tx_txg);
142
143 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
144 int compressed = BP_GET_PSIZE(bp);
145 int uncompressed = BP_GET_UCSIZE(bp);
146
147 ASSERT(used > 0);
148 if (ds == NULL) {
149 /*
150 * Account for the meta-objset space in its placeholder
151 * dataset.
152 */
153 dsl_free(tx->tx_pool, tx->tx_txg, bp);
154
155 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD,
156 -used, -compressed, -uncompressed, tx);
157 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx);
158 return (used);
159 }
160 ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool);
161
162 ASSERT(!dsl_dataset_is_snapshot(ds));
163 dmu_buf_will_dirty(ds->ds_dbuf, tx);
164
165 if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) {
166 int64_t delta;
167
168 dprintf_bp(bp, "freeing ds=%llu", ds->ds_object);
169 dsl_free(tx->tx_pool, tx->tx_txg, bp);
170
171 mutex_enter(&ds->ds_dir->dd_lock);
172 mutex_enter(&ds->ds_lock);
173 ASSERT(ds->ds_phys->ds_unique_bytes >= used ||
174 !DS_UNIQUE_IS_ACCURATE(ds));
175 delta = parent_delta(ds, -used);
176 ds->ds_phys->ds_unique_bytes -= used;
177 mutex_exit(&ds->ds_lock);
178 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
179 delta, -compressed, -uncompressed, tx);
180 dsl_dir_transfer_space(ds->ds_dir, -used - delta,
181 DD_USED_REFRSRV, DD_USED_HEAD, tx);
182 mutex_exit(&ds->ds_dir->dd_lock);
183 } else {
184 dprintf_bp(bp, "putting on dead list: %s", "");
185 if (async) {
186 /*
187 * We are here as part of zio's write done callback,
188 * which means we're a zio interrupt thread. We can't
189 * call dsl_deadlist_insert() now because it may block
190 * waiting for I/O. Instead, put bp on the deferred
191 * queue and let dsl_pool_sync() finish the job.
192 */
193 bplist_append(&ds->ds_pending_deadlist, bp);
194 } else {
195 dsl_deadlist_insert(&ds->ds_deadlist, bp, tx);
196 }
197 ASSERT3U(ds->ds_prev->ds_object, ==,
198 ds->ds_phys->ds_prev_snap_obj);
199 ASSERT(ds->ds_prev->ds_phys->ds_num_children > 0);
200 /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */
201 if (ds->ds_prev->ds_phys->ds_next_snap_obj ==
202 ds->ds_object && bp->blk_birth >
203 ds->ds_prev->ds_phys->ds_prev_snap_txg) {
204 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
205 mutex_enter(&ds->ds_prev->ds_lock);
206 ds->ds_prev->ds_phys->ds_unique_bytes += used;
207 mutex_exit(&ds->ds_prev->ds_lock);
208 }
209 if (bp->blk_birth > ds->ds_dir->dd_origin_txg) {
210 dsl_dir_transfer_space(ds->ds_dir, used,
211 DD_USED_HEAD, DD_USED_SNAP, tx);
212 }
213 }
214 mutex_enter(&ds->ds_lock);
215 ASSERT3U(ds->ds_phys->ds_used_bytes, >=, used);
216 ds->ds_phys->ds_used_bytes -= used;
217 ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed);
218 ds->ds_phys->ds_compressed_bytes -= compressed;
219 ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed);
220 ds->ds_phys->ds_uncompressed_bytes -= uncompressed;
221 mutex_exit(&ds->ds_lock);
222
223 return (used);
224}
225
226uint64_t
227dsl_dataset_prev_snap_txg(dsl_dataset_t *ds)
228{
229 uint64_t trysnap = 0;
230
231 if (ds == NULL)
232 return (0);
233 /*
234 * The snapshot creation could fail, but that would cause an
235 * incorrect FALSE return, which would only result in an
236 * overestimation of the amount of space that an operation would
237 * consume, which is OK.
238 *
239 * There's also a small window where we could miss a pending
240 * snapshot, because we could set the sync task in the quiescing
241 * phase. So this should only be used as a guess.
242 */
243 if (ds->ds_trysnap_txg >
244 spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa))
245 trysnap = ds->ds_trysnap_txg;
246 return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap));
247}
248
249boolean_t
250dsl_dataset_block_freeable(dsl_dataset_t *ds, const blkptr_t *bp,
251 uint64_t blk_birth)
252{
253 if (blk_birth <= dsl_dataset_prev_snap_txg(ds))
254 return (B_FALSE);
255
256 ddt_prefetch(dsl_dataset_get_spa(ds), bp);
257
258 return (B_TRUE);
259}
260
261/* ARGSUSED */
262static void
263dsl_dataset_evict(dmu_buf_t *db, void *dsv)
264{
265 dsl_dataset_t *ds = dsv;
266
267 ASSERT(ds->ds_owner == NULL || DSL_DATASET_IS_DESTROYED(ds));
268
269 unique_remove(ds->ds_fsid_guid);
270
271 if (ds->ds_objset != NULL)
272 dmu_objset_evict(ds->ds_objset);
273
274 if (ds->ds_prev) {
275 dsl_dataset_drop_ref(ds->ds_prev, ds);
276 ds->ds_prev = NULL;
277 }
278
279 bplist_destroy(&ds->ds_pending_deadlist);
280 if (db != NULL) {
281 dsl_deadlist_close(&ds->ds_deadlist);
282 } else {
283 ASSERT(ds->ds_deadlist.dl_dbuf == NULL);
284 ASSERT(!ds->ds_deadlist.dl_oldfmt);
285 }
286 if (ds->ds_dir)
287 dsl_dir_close(ds->ds_dir, ds);
288
289 ASSERT(!list_link_active(&ds->ds_synced_link));
290
291 if (mutex_owned(&ds->ds_lock))
292 mutex_exit(&ds->ds_lock);
293 mutex_destroy(&ds->ds_lock);
294 mutex_destroy(&ds->ds_recvlock);
295 if (mutex_owned(&ds->ds_opening_lock))
296 mutex_exit(&ds->ds_opening_lock);
297 mutex_destroy(&ds->ds_opening_lock);
298 rw_destroy(&ds->ds_rwlock);
299 cv_destroy(&ds->ds_exclusive_cv);
300
301 kmem_free(ds, sizeof (dsl_dataset_t));
302}
303
304static int
305dsl_dataset_get_snapname(dsl_dataset_t *ds)
306{
307 dsl_dataset_phys_t *headphys;
308 int err;
309 dmu_buf_t *headdbuf;
310 dsl_pool_t *dp = ds->ds_dir->dd_pool;
311 objset_t *mos = dp->dp_meta_objset;
312
313 if (ds->ds_snapname[0])
314 return (0);
315 if (ds->ds_phys->ds_next_snap_obj == 0)
316 return (0);
317
318 err = dmu_bonus_hold(mos, ds->ds_dir->dd_phys->dd_head_dataset_obj,
319 FTAG, &headdbuf);
320 if (err)
321 return (err);
322 headphys = headdbuf->db_data;
323 err = zap_value_search(dp->dp_meta_objset,
324 headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname);
325 dmu_buf_rele(headdbuf, FTAG);
326 return (err);
327}
328
329static int
330dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name, uint64_t *value)
331{
332 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
333 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
334 matchtype_t mt;
335 int err;
336
337 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
338 mt = MT_FIRST;
339 else
340 mt = MT_EXACT;
341
342 err = zap_lookup_norm(mos, snapobj, name, 8, 1,
343 value, mt, NULL, 0, NULL);
344 if (err == ENOTSUP && mt == MT_FIRST)
345 err = zap_lookup(mos, snapobj, name, 8, 1, value);
346 return (err);
347}
348
349static int
350dsl_dataset_snap_remove(dsl_dataset_t *ds, char *name, dmu_tx_t *tx)
351{
352 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
353 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
354 matchtype_t mt;
355 int err;
356
357 dsl_dir_snap_cmtime_update(ds->ds_dir);
358
359 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
360 mt = MT_FIRST;
361 else
362 mt = MT_EXACT;
363
364 err = zap_remove_norm(mos, snapobj, name, mt, tx);
365 if (err == ENOTSUP && mt == MT_FIRST)
366 err = zap_remove(mos, snapobj, name, tx);
367 return (err);
368}
369
370static int
371dsl_dataset_get_ref(dsl_pool_t *dp, uint64_t dsobj, void *tag,
372 dsl_dataset_t **dsp)
373{
374 objset_t *mos = dp->dp_meta_objset;
375 dmu_buf_t *dbuf;
376 dsl_dataset_t *ds;
377 int err;
378 dmu_object_info_t doi;
379
380 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) ||
381 dsl_pool_sync_context(dp));
382
383 err = dmu_bonus_hold(mos, dsobj, tag, &dbuf);
384 if (err)
385 return (err);
386
387 /* Make sure dsobj has the correct object type. */
388 dmu_object_info_from_db(dbuf, &doi);
389 if (doi.doi_type != DMU_OT_DSL_DATASET)
390 return (EINVAL);
391
392 ds = dmu_buf_get_user(dbuf);
393 if (ds == NULL) {
394 dsl_dataset_t *winner;
395
396 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP);
397 ds->ds_dbuf = dbuf;
398 ds->ds_object = dsobj;
399 ds->ds_phys = dbuf->db_data;
400
401 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL);
402 mutex_init(&ds->ds_recvlock, NULL, MUTEX_DEFAULT, NULL);
403 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL);
404 rw_init(&ds->ds_rwlock, 0, 0, 0);
405 cv_init(&ds->ds_exclusive_cv, NULL, CV_DEFAULT, NULL);
406
407 bplist_create(&ds->ds_pending_deadlist);
408 dsl_deadlist_open(&ds->ds_deadlist,
409 mos, ds->ds_phys->ds_deadlist_obj);
410
411 if (err == 0) {
412 err = dsl_dir_open_obj(dp,
413 ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir);
414 }
415 if (err) {
416 mutex_destroy(&ds->ds_lock);
417 mutex_destroy(&ds->ds_recvlock);
418 mutex_destroy(&ds->ds_opening_lock);
419 rw_destroy(&ds->ds_rwlock);
420 cv_destroy(&ds->ds_exclusive_cv);
421 bplist_destroy(&ds->ds_pending_deadlist);
422 dsl_deadlist_close(&ds->ds_deadlist);
423 kmem_free(ds, sizeof (dsl_dataset_t));
424 dmu_buf_rele(dbuf, tag);
425 return (err);
426 }
427
428 if (!dsl_dataset_is_snapshot(ds)) {
429 ds->ds_snapname[0] = '\0';
430 if (ds->ds_phys->ds_prev_snap_obj) {
431 err = dsl_dataset_get_ref(dp,
432 ds->ds_phys->ds_prev_snap_obj,
433 ds, &ds->ds_prev);
434 }
435 } else {
436 if (zfs_flags & ZFS_DEBUG_SNAPNAMES)
437 err = dsl_dataset_get_snapname(ds);
438 if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) {
439 err = zap_count(
440 ds->ds_dir->dd_pool->dp_meta_objset,
441 ds->ds_phys->ds_userrefs_obj,
442 &ds->ds_userrefs);
443 }
444 }
445
446 if (err == 0 && !dsl_dataset_is_snapshot(ds)) {
447 /*
448 * In sync context, we're called with either no lock
449 * or with the write lock. If we're not syncing,
450 * we're always called with the read lock held.
451 */
452 boolean_t need_lock =
453 !RW_WRITE_HELD(&dp->dp_config_rwlock) &&
454 dsl_pool_sync_context(dp);
455
456 if (need_lock)
457 rw_enter(&dp->dp_config_rwlock, RW_READER);
458
459 err = dsl_prop_get_ds(ds,
460 "refreservation", sizeof (uint64_t), 1,
461 &ds->ds_reserved, NULL);
462 if (err == 0) {
463 err = dsl_prop_get_ds(ds,
464 "refquota", sizeof (uint64_t), 1,
465 &ds->ds_quota, NULL);
466 }
467
468 if (need_lock)
469 rw_exit(&dp->dp_config_rwlock);
470 } else {
471 ds->ds_reserved = ds->ds_quota = 0;
472 }
473
474 if (err == 0) {
475 winner = dmu_buf_set_user_ie(dbuf, ds, &ds->ds_phys,
476 dsl_dataset_evict);
477 }
478 if (err || winner) {
479 bplist_destroy(&ds->ds_pending_deadlist);
480 dsl_deadlist_close(&ds->ds_deadlist);
481 if (ds->ds_prev)
482 dsl_dataset_drop_ref(ds->ds_prev, ds);
483 dsl_dir_close(ds->ds_dir, ds);
484 mutex_destroy(&ds->ds_lock);
485 mutex_destroy(&ds->ds_recvlock);
486 mutex_destroy(&ds->ds_opening_lock);
487 rw_destroy(&ds->ds_rwlock);
488 cv_destroy(&ds->ds_exclusive_cv);
489 kmem_free(ds, sizeof (dsl_dataset_t));
490 if (err) {
491 dmu_buf_rele(dbuf, tag);
492 return (err);
493 }
494 ds = winner;
495 } else {
496 ds->ds_fsid_guid =
497 unique_insert(ds->ds_phys->ds_fsid_guid);
498 }
499 }
500 ASSERT3P(ds->ds_dbuf, ==, dbuf);
501 ASSERT3P(ds->ds_phys, ==, dbuf->db_data);
502 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 ||
503 spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN ||
504 dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap);
505 mutex_enter(&ds->ds_lock);
506 if (!dsl_pool_sync_context(dp) && DSL_DATASET_IS_DESTROYED(ds)) {
507 mutex_exit(&ds->ds_lock);
508 dmu_buf_rele(ds->ds_dbuf, tag);
509 return (ENOENT);
510 }
511 mutex_exit(&ds->ds_lock);
512 *dsp = ds;
513 return (0);
514}
515
516static int
517dsl_dataset_hold_ref(dsl_dataset_t *ds, void *tag)
518{
519 dsl_pool_t *dp = ds->ds_dir->dd_pool;
520
521 /*
522 * In syncing context we don't want the rwlock lock: there
523 * may be an existing writer waiting for sync phase to
524 * finish. We don't need to worry about such writers, since
525 * sync phase is single-threaded, so the writer can't be
526 * doing anything while we are active.
527 */
528 if (dsl_pool_sync_context(dp)) {
529 ASSERT(!DSL_DATASET_IS_DESTROYED(ds));
530 return (0);
531 }
532
533 /*
534 * Normal users will hold the ds_rwlock as a READER until they
535 * are finished (i.e., call dsl_dataset_rele()). "Owners" will
536 * drop their READER lock after they set the ds_owner field.
537 *
538 * If the dataset is being destroyed, the destroy thread will
539 * obtain a WRITER lock for exclusive access after it's done its
540 * open-context work and then change the ds_owner to
541 * dsl_reaper once destruction is assured. So threads
542 * may block here temporarily, until the "destructability" of
543 * the dataset is determined.
544 */
545 ASSERT(!RW_WRITE_HELD(&dp->dp_config_rwlock));
546 mutex_enter(&ds->ds_lock);
547 while (!rw_tryenter(&ds->ds_rwlock, RW_READER)) {
548 rw_exit(&dp->dp_config_rwlock);
549 cv_wait(&ds->ds_exclusive_cv, &ds->ds_lock);
550 if (DSL_DATASET_IS_DESTROYED(ds)) {
551 mutex_exit(&ds->ds_lock);
552 dsl_dataset_drop_ref(ds, tag);
553 rw_enter(&dp->dp_config_rwlock, RW_READER);
554 return (ENOENT);
555 }
556 /*
557 * The dp_config_rwlock lives above the ds_lock. And
558 * we need to check DSL_DATASET_IS_DESTROYED() while
559 * holding the ds_lock, so we have to drop and reacquire
560 * the ds_lock here.
561 */
562 mutex_exit(&ds->ds_lock);
563 rw_enter(&dp->dp_config_rwlock, RW_READER);
564 mutex_enter(&ds->ds_lock);
565 }
566 mutex_exit(&ds->ds_lock);
567 return (0);
568}
569
570int
571dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag,
572 dsl_dataset_t **dsp)
573{
574 int err = dsl_dataset_get_ref(dp, dsobj, tag, dsp);
575
576 if (err)
577 return (err);
578 return (dsl_dataset_hold_ref(*dsp, tag));
579}
580
581int
582dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj, boolean_t inconsistentok,
583 void *tag, dsl_dataset_t **dsp)
584{
585 int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp);
586 if (err)
587 return (err);
588 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) {
589 dsl_dataset_rele(*dsp, tag);
590 *dsp = NULL;
591 return (EBUSY);
592 }
593 return (0);
594}
595
596int
597dsl_dataset_hold(const char *name, void *tag, dsl_dataset_t **dsp)
598{
599 dsl_dir_t *dd;
600 dsl_pool_t *dp;
601 const char *snapname;
602 uint64_t obj;
603 int err = 0;
604
605 err = dsl_dir_open_spa(NULL, name, FTAG, &dd, &snapname);
606 if (err)
607 return (err);
608
609 dp = dd->dd_pool;
610 obj = dd->dd_phys->dd_head_dataset_obj;
611 rw_enter(&dp->dp_config_rwlock, RW_READER);
612 if (obj)
613 err = dsl_dataset_get_ref(dp, obj, tag, dsp);
614 else
615 err = ENOENT;
616 if (err)
617 goto out;
618
619 err = dsl_dataset_hold_ref(*dsp, tag);
620
621 /* we may be looking for a snapshot */
622 if (err == 0 && snapname != NULL) {
623 dsl_dataset_t *ds = NULL;
624
625 if (*snapname++ != '@') {
626 dsl_dataset_rele(*dsp, tag);
627 err = ENOENT;
628 goto out;
629 }
630
631 dprintf("looking for snapshot '%s'\n", snapname);
632 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj);
633 if (err == 0)
634 err = dsl_dataset_get_ref(dp, obj, tag, &ds);
635 dsl_dataset_rele(*dsp, tag);
636
637 ASSERT3U((err == 0), ==, (ds != NULL));
638
639 if (ds) {
640 mutex_enter(&ds->ds_lock);
641 if (ds->ds_snapname[0] == 0)
642 (void) strlcpy(ds->ds_snapname, snapname,
643 sizeof (ds->ds_snapname));
644 mutex_exit(&ds->ds_lock);
645 err = dsl_dataset_hold_ref(ds, tag);
646 *dsp = err ? NULL : ds;
647 }
648 }
649out:
650 rw_exit(&dp->dp_config_rwlock);
651 dsl_dir_close(dd, FTAG);
652 return (err);
653}
654
655int
656dsl_dataset_own(const char *name, boolean_t inconsistentok,
657 void *tag, dsl_dataset_t **dsp)
658{
659 int err = dsl_dataset_hold(name, tag, dsp);
660 if (err)
661 return (err);
662 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) {
663 dsl_dataset_rele(*dsp, tag);
664 return (EBUSY);
665 }
666 return (0);
667}
668
669void
670dsl_dataset_name(dsl_dataset_t *ds, char *name)
671{
672 if (ds == NULL) {
673 (void) strcpy(name, "mos");
674 } else {
675 dsl_dir_name(ds->ds_dir, name);
676 VERIFY(0 == dsl_dataset_get_snapname(ds));
677 if (ds->ds_snapname[0]) {
678 (void) strcat(name, "@");
679 /*
680 * We use a "recursive" mutex so that we
681 * can call dprintf_ds() with ds_lock held.
682 */
683 if (!MUTEX_HELD(&ds->ds_lock)) {
684 mutex_enter(&ds->ds_lock);
685 (void) strcat(name, ds->ds_snapname);
686 mutex_exit(&ds->ds_lock);
687 } else {
688 (void) strcat(name, ds->ds_snapname);
689 }
690 }
691 }
692}
693
694static int
695dsl_dataset_namelen(dsl_dataset_t *ds)
696{
697 int result;
698
699 if (ds == NULL) {
700 result = 3; /* "mos" */
701 } else {
702 result = dsl_dir_namelen(ds->ds_dir);
703 VERIFY(0 == dsl_dataset_get_snapname(ds));
704 if (ds->ds_snapname[0]) {
705 ++result; /* adding one for the @-sign */
706 if (!MUTEX_HELD(&ds->ds_lock)) {
707 mutex_enter(&ds->ds_lock);
708 result += strlen(ds->ds_snapname);
709 mutex_exit(&ds->ds_lock);
710 } else {
711 result += strlen(ds->ds_snapname);
712 }
713 }
714 }
715
716 return (result);
717}
718
719void
720dsl_dataset_drop_ref(dsl_dataset_t *ds, void *tag)
721{
722 dmu_buf_rele(ds->ds_dbuf, tag);
723}
724
725void
726dsl_dataset_rele(dsl_dataset_t *ds, void *tag)
727{
728 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) {
729 rw_exit(&ds->ds_rwlock);
730 }
731 dsl_dataset_drop_ref(ds, tag);
732}
733
734void
735dsl_dataset_disown(dsl_dataset_t *ds, void *tag)
736{
737 ASSERT((ds->ds_owner == tag && ds->ds_dbuf) ||
738 (DSL_DATASET_IS_DESTROYED(ds) && ds->ds_dbuf == NULL));
739
740 mutex_enter(&ds->ds_lock);
741 ds->ds_owner = NULL;
742 if (RW_WRITE_HELD(&ds->ds_rwlock)) {
743 rw_exit(&ds->ds_rwlock);
744 cv_broadcast(&ds->ds_exclusive_cv);
745 }
746 mutex_exit(&ds->ds_lock);
747 if (ds->ds_dbuf)
748 dsl_dataset_drop_ref(ds, tag);
749 else
750 dsl_dataset_evict(NULL, ds);
751}
752
753boolean_t
754dsl_dataset_tryown(dsl_dataset_t *ds, boolean_t inconsistentok, void *tag)
755{
756 boolean_t gotit = FALSE;
757
758 mutex_enter(&ds->ds_lock);
759 if (ds->ds_owner == NULL &&
760 (!DS_IS_INCONSISTENT(ds) || inconsistentok)) {
761 ds->ds_owner = tag;
762 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool))
763 rw_exit(&ds->ds_rwlock);
764 gotit = TRUE;
765 }
766 mutex_exit(&ds->ds_lock);
767 return (gotit);
768}
769
770void
771dsl_dataset_make_exclusive(dsl_dataset_t *ds, void *owner)
772{
773 ASSERT3P(owner, ==, ds->ds_owner);
774 if (!RW_WRITE_HELD(&ds->ds_rwlock))
775 rw_enter(&ds->ds_rwlock, RW_WRITER);
776}
777
778uint64_t
779dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin,
780 uint64_t flags, dmu_tx_t *tx)
781{
782 dsl_pool_t *dp = dd->dd_pool;
783 dmu_buf_t *dbuf;
784 dsl_dataset_phys_t *dsphys;
785 uint64_t dsobj;
786 objset_t *mos = dp->dp_meta_objset;
787
788 if (origin == NULL)
789 origin = dp->dp_origin_snap;
790
791 ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp);
792 ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0);
793 ASSERT(dmu_tx_is_syncing(tx));
794 ASSERT(dd->dd_phys->dd_head_dataset_obj == 0);
795
796 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
797 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
798 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
799 dmu_buf_will_dirty(dbuf, tx);
800 dsphys = dbuf->db_data;
801 bzero(dsphys, sizeof (dsl_dataset_phys_t));
802 dsphys->ds_dir_obj = dd->dd_object;
803 dsphys->ds_flags = flags;
804 dsphys->ds_fsid_guid = unique_create();
805 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
806 sizeof (dsphys->ds_guid));
807 dsphys->ds_snapnames_zapobj =
808 zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP,
809 DMU_OT_NONE, 0, tx);
810 dsphys->ds_creation_time = gethrestime_sec();
811 dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg;
812
813 if (origin == NULL) {
814 dsphys->ds_deadlist_obj = dsl_deadlist_alloc(mos, tx);
815 } else {
816 dsl_dataset_t *ohds;
817
818 dsphys->ds_prev_snap_obj = origin->ds_object;
819 dsphys->ds_prev_snap_txg =
820 origin->ds_phys->ds_creation_txg;
821 dsphys->ds_used_bytes =
822 origin->ds_phys->ds_used_bytes;
823 dsphys->ds_compressed_bytes =
824 origin->ds_phys->ds_compressed_bytes;
825 dsphys->ds_uncompressed_bytes =
826 origin->ds_phys->ds_uncompressed_bytes;
827 dsphys->ds_bp = origin->ds_phys->ds_bp;
828 dsphys->ds_flags |= origin->ds_phys->ds_flags;
829
830 dmu_buf_will_dirty(origin->ds_dbuf, tx);
831 origin->ds_phys->ds_num_children++;
832
833 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
834 origin->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ohds));
835 dsphys->ds_deadlist_obj = dsl_deadlist_clone(&ohds->ds_deadlist,
836 dsphys->ds_prev_snap_txg, dsphys->ds_prev_snap_obj, tx);
837 dsl_dataset_rele(ohds, FTAG);
838
839 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) {
840 if (origin->ds_phys->ds_next_clones_obj == 0) {
841 origin->ds_phys->ds_next_clones_obj =
842 zap_create(mos,
843 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx);
844 }
845 VERIFY(0 == zap_add_int(mos,
846 origin->ds_phys->ds_next_clones_obj,
847 dsobj, tx));
848 }
849
850 dmu_buf_will_dirty(dd->dd_dbuf, tx);
851 dd->dd_phys->dd_origin_obj = origin->ds_object;
852 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
853 if (origin->ds_dir->dd_phys->dd_clones == 0) {
854 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx);
855 origin->ds_dir->dd_phys->dd_clones =
856 zap_create(mos,
857 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
858 }
859 VERIFY3U(0, ==, zap_add_int(mos,
860 origin->ds_dir->dd_phys->dd_clones, dsobj, tx));
861 }
862 }
863
864 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
865 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
866
867 dmu_buf_rele(dbuf, FTAG);
868
869 dmu_buf_will_dirty(dd->dd_dbuf, tx);
870 dd->dd_phys->dd_head_dataset_obj = dsobj;
871
872 return (dsobj);
873}
874
875uint64_t
876dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname,
877 dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx)
878{
879 dsl_pool_t *dp = pdd->dd_pool;
880 uint64_t dsobj, ddobj;
881 dsl_dir_t *dd;
882
883 ASSERT(lastname[0] != '@');
884
885 ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx);
886 VERIFY(0 == dsl_dir_open_obj(dp, ddobj, lastname, FTAG, &dd));
887
888 dsobj = dsl_dataset_create_sync_dd(dd, origin, flags, tx);
889
890 dsl_deleg_set_create_perms(dd, tx, cr);
891
892 dsl_dir_close(dd, FTAG);
893
894 /*
895 * If we are creating a clone, make sure we zero out any stale
896 * data from the origin snapshots zil header.
897 */
898 if (origin != NULL) {
899 dsl_dataset_t *ds;
900 objset_t *os;
901
902 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
903 VERIFY3U(0, ==, dmu_objset_from_ds(ds, &os));
904 bzero(&os->os_zil_header, sizeof (os->os_zil_header));
905 dsl_dataset_dirty(ds, tx);
906 dsl_dataset_rele(ds, FTAG);
907 }
908
909 return (dsobj);
910}
911
|
| 912#ifdef __FreeBSD__
913/* FreeBSD ioctl compat begin */
|
911struct destroyarg {
| 914struct destroyarg {
|
912 dsl_sync_task_group_t *dstg;
913 char *snapname;
914 char *failed;
915 boolean_t defer;
| 915 nvlist_t *nvl;
916 const char *snapname;
|
916};
917
918static int
| 917};
918
919static int
|
919dsl_snapshot_destroy_one(const char *name, void *arg)
| 920dsl_check_snap_cb(const char *name, void *arg)
|
920{
921 struct destroyarg *da = arg;
922 dsl_dataset_t *ds;
| 921{
922 struct destroyarg *da = arg;
923 dsl_dataset_t *ds;
|
923 int err;
| |
924 char *dsname;
925
926 dsname = kmem_asprintf("%s@%s", name, da->snapname);
| 924 char *dsname;
925
926 dsname = kmem_asprintf("%s@%s", name, da->snapname);
|
927 err = dsl_dataset_own(dsname, B_TRUE, da->dstg, &ds);
928 strfree(dsname);
929 if (err == 0) {
930 struct dsl_ds_destroyarg *dsda;
| 927 VERIFY(nvlist_add_boolean(da->nvl, dsname) == 0);
|
931
| 928
|
932 dsl_dataset_make_exclusive(ds, da->dstg);
933 dsda = kmem_zalloc(sizeof (struct dsl_ds_destroyarg), KM_SLEEP);
934 dsda->ds = ds;
935 dsda->defer = da->defer;
936 dsl_sync_task_create(da->dstg, dsl_dataset_destroy_check,
937 dsl_dataset_destroy_sync, dsda, da->dstg, 0);
938 } else if (err == ENOENT) {
939 err = 0;
940 } else {
941 (void) strcpy(da->failed, name);
942 }
| 929 return (0);
930}
931
932int
933dmu_get_recursive_snaps_nvl(const char *fsname, const char *snapname,
934 nvlist_t *snaps)
935{
936 struct destroyarg *da;
937 int err;
938
939 da = kmem_zalloc(sizeof (struct destroyarg), KM_SLEEP);
940 da->nvl = snaps;
941 da->snapname = snapname;
942 err = dmu_objset_find(fsname, dsl_check_snap_cb, da,
943 DS_FIND_CHILDREN);
944 kmem_free(da, sizeof (struct destroyarg));
945
|
943 return (err);
944}
| 946 return (err);
947}
|
| 948/* FreeBSD ioctl compat end */
949#endif /* __FreeBSD__ */
|
945
946/*
| 950
951/*
|
947 * Destroy 'snapname' in all descendants of 'fsname'.
| 952 * The snapshots must all be in the same pool.
|
948 */
| 953 */
|
949#pragma weak dmu_snapshots_destroy = dsl_snapshots_destroy
| |
950int
| 954int
|
951dsl_snapshots_destroy(char *fsname, char *snapname, boolean_t defer)
| 955dmu_snapshots_destroy_nvl(nvlist_t *snaps, boolean_t defer, char *failed)
|
952{
953 int err;
| 956{
957 int err;
|
954 struct destroyarg da;
| |
955 dsl_sync_task_t *dst;
956 spa_t *spa;
| 958 dsl_sync_task_t *dst;
959 spa_t *spa;
|
| 960 nvpair_t *pair;
961 dsl_sync_task_group_t *dstg;
|
957
| 962
|
958 err = spa_open(fsname, &spa, FTAG);
| 963 pair = nvlist_next_nvpair(snaps, NULL);
964 if (pair == NULL)
965 return (0);
966
967 err = spa_open(nvpair_name(pair), &spa, FTAG);
|
959 if (err)
960 return (err);
| 968 if (err)
969 return (err);
|
961 da.dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
962 da.snapname = snapname;
963 da.failed = fsname;
964 da.defer = defer;
| 970 dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
|
965
| 971
|
966 err = dmu_objset_find(fsname,
967 dsl_snapshot_destroy_one, &da, DS_FIND_CHILDREN);
| 972 for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL;
973 pair = nvlist_next_nvpair(snaps, pair)) {
974 dsl_dataset_t *ds;
975 int err;
|
968
| 976
|
| 977 err = dsl_dataset_own(nvpair_name(pair), B_TRUE, dstg, &ds);
978 if (err == 0) {
979 struct dsl_ds_destroyarg *dsda;
980
981 dsl_dataset_make_exclusive(ds, dstg);
982 dsda = kmem_zalloc(sizeof (struct dsl_ds_destroyarg),
983 KM_SLEEP);
984 dsda->ds = ds;
985 dsda->defer = defer;
986 dsl_sync_task_create(dstg, dsl_dataset_destroy_check,
987 dsl_dataset_destroy_sync, dsda, dstg, 0);
988 } else if (err == ENOENT) {
989 err = 0;
990 } else {
991 (void) strcpy(failed, nvpair_name(pair));
992 break;
993 }
994 }
995
|
969 if (err == 0)
| 996 if (err == 0)
|
970 err = dsl_sync_task_group_wait(da.dstg);
| 997 err = dsl_sync_task_group_wait(dstg);
|
971
| 998
|
972 for (dst = list_head(&da.dstg->dstg_tasks); dst;
973 dst = list_next(&da.dstg->dstg_tasks, dst)) {
| 999 for (dst = list_head(&dstg->dstg_tasks); dst;
1000 dst = list_next(&dstg->dstg_tasks, dst)) {
|
974 struct dsl_ds_destroyarg *dsda = dst->dst_arg1;
975 dsl_dataset_t *ds = dsda->ds;
976
977 /*
978 * Return the file system name that triggered the error
979 */
980 if (dst->dst_err) {
| 1001 struct dsl_ds_destroyarg *dsda = dst->dst_arg1;
1002 dsl_dataset_t *ds = dsda->ds;
1003
1004 /*
1005 * Return the file system name that triggered the error
1006 */
1007 if (dst->dst_err) {
|
981 dsl_dataset_name(ds, fsname);
982 *strchr(fsname, '@') = '\0';
| 1008 dsl_dataset_name(ds, failed);
|
983 }
984 ASSERT3P(dsda->rm_origin, ==, NULL);
| 1009 }
1010 ASSERT3P(dsda->rm_origin, ==, NULL);
|
985 dsl_dataset_disown(ds, da.dstg);
| 1011 dsl_dataset_disown(ds, dstg);
|
986 kmem_free(dsda, sizeof (struct dsl_ds_destroyarg));
987 }
988
| 1012 kmem_free(dsda, sizeof (struct dsl_ds_destroyarg));
1013 }
1014
|
989 dsl_sync_task_group_destroy(da.dstg);
| 1015 dsl_sync_task_group_destroy(dstg);
|
990 spa_close(spa, FTAG);
991 return (err);
| 1016 spa_close(spa, FTAG);
1017 return (err);
|
| 1018
|
992}
993
994static boolean_t
995dsl_dataset_might_destroy_origin(dsl_dataset_t *ds)
996{
997 boolean_t might_destroy = B_FALSE;
998
999 mutex_enter(&ds->ds_lock);
1000 if (ds->ds_phys->ds_num_children == 2 && ds->ds_userrefs == 0 &&
1001 DS_IS_DEFER_DESTROY(ds))
1002 might_destroy = B_TRUE;
1003 mutex_exit(&ds->ds_lock);
1004
1005 return (might_destroy);
1006}
1007
1008/*
1009 * If we're removing a clone, and these three conditions are true:
1010 * 1) the clone's origin has no other children
1011 * 2) the clone's origin has no user references
1012 * 3) the clone's origin has been marked for deferred destruction
1013 * Then, prepare to remove the origin as part of this sync task group.
1014 */
1015static int
1016dsl_dataset_origin_rm_prep(struct dsl_ds_destroyarg *dsda, void *tag)
1017{
1018 dsl_dataset_t *ds = dsda->ds;
1019 dsl_dataset_t *origin = ds->ds_prev;
1020
1021 if (dsl_dataset_might_destroy_origin(origin)) {
1022 char *name;
1023 int namelen;
1024 int error;
1025
1026 namelen = dsl_dataset_namelen(origin) + 1;
1027 name = kmem_alloc(namelen, KM_SLEEP);
1028 dsl_dataset_name(origin, name);
1029#ifdef _KERNEL
1030 error = zfs_unmount_snap(name, NULL);
1031 if (error) {
1032 kmem_free(name, namelen);
1033 return (error);
1034 }
1035#endif
1036 error = dsl_dataset_own(name, B_TRUE, tag, &origin);
1037 kmem_free(name, namelen);
1038 if (error)
1039 return (error);
1040 dsda->rm_origin = origin;
1041 dsl_dataset_make_exclusive(origin, tag);
1042 }
1043
1044 return (0);
1045}
1046
1047/*
1048 * ds must be opened as OWNER. On return (whether successful or not),
1049 * ds will be closed and caller can no longer dereference it.
1050 */
1051int
1052dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer)
1053{
1054 int err;
1055 dsl_sync_task_group_t *dstg;
1056 objset_t *os;
1057 dsl_dir_t *dd;
1058 uint64_t obj;
1059 struct dsl_ds_destroyarg dsda = { 0 };
1060 dsl_dataset_t dummy_ds = { 0 };
1061
1062 dsda.ds = ds;
1063
1064 if (dsl_dataset_is_snapshot(ds)) {
1065 /* Destroying a snapshot is simpler */
1066 dsl_dataset_make_exclusive(ds, tag);
1067
1068 dsda.defer = defer;
1069 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
1070 dsl_dataset_destroy_check, dsl_dataset_destroy_sync,
1071 &dsda, tag, 0);
1072 ASSERT3P(dsda.rm_origin, ==, NULL);
1073 goto out;
1074 } else if (defer) {
1075 err = EINVAL;
1076 goto out;
1077 }
1078
1079 dd = ds->ds_dir;
1080 dummy_ds.ds_dir = dd;
1081 dummy_ds.ds_object = ds->ds_object;
1082
1083 /*
1084 * Check for errors and mark this ds as inconsistent, in
1085 * case we crash while freeing the objects.
1086 */
1087 err = dsl_sync_task_do(dd->dd_pool, dsl_dataset_destroy_begin_check,
1088 dsl_dataset_destroy_begin_sync, ds, NULL, 0);
1089 if (err)
1090 goto out;
1091
1092 err = dmu_objset_from_ds(ds, &os);
1093 if (err)
1094 goto out;
1095
1096 /*
1097 * remove the objects in open context, so that we won't
1098 * have too much to do in syncing context.
1099 */
1100 for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE,
1101 ds->ds_phys->ds_prev_snap_txg)) {
1102 /*
1103 * Ignore errors, if there is not enough disk space
1104 * we will deal with it in dsl_dataset_destroy_sync().
1105 */
1106 (void) dmu_free_object(os, obj);
1107 }
1108 if (err != ESRCH)
1109 goto out;
1110
1111 /*
1112 * Only the ZIL knows how to free log blocks.
1113 */
1114 zil_destroy(dmu_objset_zil(os), B_FALSE);
1115
1116 /*
1117 * Sync out all in-flight IO.
1118 */
1119 txg_wait_synced(dd->dd_pool, 0);
1120
1121 /*
1122 * If we managed to free all the objects in open
1123 * context, the user space accounting should be zero.
1124 */
1125 if (ds->ds_phys->ds_bp.blk_fill == 0 &&
1126 dmu_objset_userused_enabled(os)) {
1127 uint64_t count;
1128
1129 ASSERT(zap_count(os, DMU_USERUSED_OBJECT, &count) != 0 ||
1130 count == 0);
1131 ASSERT(zap_count(os, DMU_GROUPUSED_OBJECT, &count) != 0 ||
1132 count == 0);
1133 }
1134
1135 rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
1136 err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd);
1137 rw_exit(&dd->dd_pool->dp_config_rwlock);
1138
1139 if (err)
1140 goto out;
1141
1142 /*
1143 * Blow away the dsl_dir + head dataset.
1144 */
1145 dsl_dataset_make_exclusive(ds, tag);
1146 /*
1147 * If we're removing a clone, we might also need to remove its
1148 * origin.
1149 */
1150 do {
1151 dsda.need_prep = B_FALSE;
1152 if (dsl_dir_is_clone(dd)) {
1153 err = dsl_dataset_origin_rm_prep(&dsda, tag);
1154 if (err) {
1155 dsl_dir_close(dd, FTAG);
1156 goto out;
1157 }
1158 }
1159
1160 dstg = dsl_sync_task_group_create(ds->ds_dir->dd_pool);
1161 dsl_sync_task_create(dstg, dsl_dataset_destroy_check,
1162 dsl_dataset_destroy_sync, &dsda, tag, 0);
1163 dsl_sync_task_create(dstg, dsl_dir_destroy_check,
1164 dsl_dir_destroy_sync, &dummy_ds, FTAG, 0);
1165 err = dsl_sync_task_group_wait(dstg);
1166 dsl_sync_task_group_destroy(dstg);
1167
1168 /*
1169 * We could be racing against 'zfs release' or 'zfs destroy -d'
1170 * on the origin snap, in which case we can get EBUSY if we
1171 * needed to destroy the origin snap but were not ready to
1172 * do so.
1173 */
1174 if (dsda.need_prep) {
1175 ASSERT(err == EBUSY);
1176 ASSERT(dsl_dir_is_clone(dd));
1177 ASSERT(dsda.rm_origin == NULL);
1178 }
1179 } while (dsda.need_prep);
1180
1181 if (dsda.rm_origin != NULL)
1182 dsl_dataset_disown(dsda.rm_origin, tag);
1183
1184 /* if it is successful, dsl_dir_destroy_sync will close the dd */
1185 if (err)
1186 dsl_dir_close(dd, FTAG);
1187out:
1188 dsl_dataset_disown(ds, tag);
1189 return (err);
1190}
1191
1192blkptr_t *
1193dsl_dataset_get_blkptr(dsl_dataset_t *ds)
1194{
1195 return (&ds->ds_phys->ds_bp);
1196}
1197
1198void
1199dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx)
1200{
1201 ASSERT(dmu_tx_is_syncing(tx));
1202 /* If it's the meta-objset, set dp_meta_rootbp */
1203 if (ds == NULL) {
1204 tx->tx_pool->dp_meta_rootbp = *bp;
1205 } else {
1206 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1207 ds->ds_phys->ds_bp = *bp;
1208 }
1209}
1210
1211spa_t *
1212dsl_dataset_get_spa(dsl_dataset_t *ds)
1213{
1214 return (ds->ds_dir->dd_pool->dp_spa);
1215}
1216
1217void
1218dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx)
1219{
1220 dsl_pool_t *dp;
1221
1222 if (ds == NULL) /* this is the meta-objset */
1223 return;
1224
1225 ASSERT(ds->ds_objset != NULL);
1226
1227 if (ds->ds_phys->ds_next_snap_obj != 0)
1228 panic("dirtying snapshot!");
1229
1230 dp = ds->ds_dir->dd_pool;
1231
1232 if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg) == 0) {
1233 /* up the hold count until we can be written out */
1234 dmu_buf_add_ref(ds->ds_dbuf, ds);
1235 }
1236}
1237
1238/*
1239 * The unique space in the head dataset can be calculated by subtracting
1240 * the space used in the most recent snapshot, that is still being used
1241 * in this file system, from the space currently in use. To figure out
1242 * the space in the most recent snapshot still in use, we need to take
1243 * the total space used in the snapshot and subtract out the space that
1244 * has been freed up since the snapshot was taken.
1245 */
1246static void
1247dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds)
1248{
1249 uint64_t mrs_used;
1250 uint64_t dlused, dlcomp, dluncomp;
1251
1252 ASSERT(!dsl_dataset_is_snapshot(ds));
1253
1254 if (ds->ds_phys->ds_prev_snap_obj != 0)
1255 mrs_used = ds->ds_prev->ds_phys->ds_used_bytes;
1256 else
1257 mrs_used = 0;
1258
1259 dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp);
1260
1261 ASSERT3U(dlused, <=, mrs_used);
1262 ds->ds_phys->ds_unique_bytes =
1263 ds->ds_phys->ds_used_bytes - (mrs_used - dlused);
1264
1265 if (spa_version(ds->ds_dir->dd_pool->dp_spa) >=
1266 SPA_VERSION_UNIQUE_ACCURATE)
1267 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
1268}
1269
1270struct killarg {
1271 dsl_dataset_t *ds;
1272 dmu_tx_t *tx;
1273};
1274
1275/* ARGSUSED */
1276static int
1277kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf,
1278 const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
1279{
1280 struct killarg *ka = arg;
1281 dmu_tx_t *tx = ka->tx;
1282
1283 if (bp == NULL)
1284 return (0);
1285
1286 if (zb->zb_level == ZB_ZIL_LEVEL) {
1287 ASSERT(zilog != NULL);
1288 /*
1289 * It's a block in the intent log. It has no
1290 * accounting, so just free it.
1291 */
1292 dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp);
1293 } else {
1294 ASSERT(zilog == NULL);
1295 ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg);
1296 (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE);
1297 }
1298
1299 return (0);
1300}
1301
1302/* ARGSUSED */
1303static int
1304dsl_dataset_destroy_begin_check(void *arg1, void *arg2, dmu_tx_t *tx)
1305{
1306 dsl_dataset_t *ds = arg1;
1307 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1308 uint64_t count;
1309 int err;
1310
1311 /*
1312 * Can't delete a head dataset if there are snapshots of it.
1313 * (Except if the only snapshots are from the branch we cloned
1314 * from.)
1315 */
1316 if (ds->ds_prev != NULL &&
1317 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object)
1318 return (EBUSY);
1319
1320 /*
1321 * This is really a dsl_dir thing, but check it here so that
1322 * we'll be less likely to leave this dataset inconsistent &
1323 * nearly destroyed.
1324 */
1325 err = zap_count(mos, ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count);
1326 if (err)
1327 return (err);
1328 if (count != 0)
1329 return (EEXIST);
1330
1331 return (0);
1332}
1333
1334/* ARGSUSED */
1335static void
1336dsl_dataset_destroy_begin_sync(void *arg1, void *arg2, dmu_tx_t *tx)
1337{
1338 dsl_dataset_t *ds = arg1;
1339 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1340
1341 /* Mark it as inconsistent on-disk, in case we crash */
1342 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1343 ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT;
1344
1345 spa_history_log_internal(LOG_DS_DESTROY_BEGIN, dp->dp_spa, tx,
1346 "dataset = %llu", ds->ds_object);
1347}
1348
1349static int
1350dsl_dataset_origin_check(struct dsl_ds_destroyarg *dsda, void *tag,
1351 dmu_tx_t *tx)
1352{
1353 dsl_dataset_t *ds = dsda->ds;
1354 dsl_dataset_t *ds_prev = ds->ds_prev;
1355
1356 if (dsl_dataset_might_destroy_origin(ds_prev)) {
1357 struct dsl_ds_destroyarg ndsda = {0};
1358
1359 /*
1360 * If we're not prepared to remove the origin, don't remove
1361 * the clone either.
1362 */
1363 if (dsda->rm_origin == NULL) {
1364 dsda->need_prep = B_TRUE;
1365 return (EBUSY);
1366 }
1367
1368 ndsda.ds = ds_prev;
1369 ndsda.is_origin_rm = B_TRUE;
1370 return (dsl_dataset_destroy_check(&ndsda, tag, tx));
1371 }
1372
1373 /*
1374 * If we're not going to remove the origin after all,
1375 * undo the open context setup.
1376 */
1377 if (dsda->rm_origin != NULL) {
1378 dsl_dataset_disown(dsda->rm_origin, tag);
1379 dsda->rm_origin = NULL;
1380 }
1381
1382 return (0);
1383}
1384
1385/*
1386 * If you add new checks here, you may need to add
1387 * additional checks to the "temporary" case in
1388 * snapshot_check() in dmu_objset.c.
1389 */
1390/* ARGSUSED */
1391int
1392dsl_dataset_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx)
1393{
1394 struct dsl_ds_destroyarg *dsda = arg1;
1395 dsl_dataset_t *ds = dsda->ds;
1396
1397 /* we have an owner hold, so noone else can destroy us */
1398 ASSERT(!DSL_DATASET_IS_DESTROYED(ds));
1399
1400 /*
1401 * Only allow deferred destroy on pools that support it.
1402 * NOTE: deferred destroy is only supported on snapshots.
1403 */
1404 if (dsda->defer) {
1405 if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
1406 SPA_VERSION_USERREFS)
1407 return (ENOTSUP);
1408 ASSERT(dsl_dataset_is_snapshot(ds));
1409 return (0);
1410 }
1411
1412 /*
1413 * Can't delete a head dataset if there are snapshots of it.
1414 * (Except if the only snapshots are from the branch we cloned
1415 * from.)
1416 */
1417 if (ds->ds_prev != NULL &&
1418 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object)
1419 return (EBUSY);
1420
1421 /*
1422 * If we made changes this txg, traverse_dsl_dataset won't find
1423 * them. Try again.
1424 */
1425 if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg)
1426 return (EAGAIN);
1427
1428 if (dsl_dataset_is_snapshot(ds)) {
1429 /*
1430 * If this snapshot has an elevated user reference count,
1431 * we can't destroy it yet.
1432 */
1433 if (ds->ds_userrefs > 0 && !dsda->releasing)
1434 return (EBUSY);
1435
1436 mutex_enter(&ds->ds_lock);
1437 /*
1438 * Can't delete a branch point. However, if we're destroying
1439 * a clone and removing its origin due to it having a user
1440 * hold count of 0 and having been marked for deferred destroy,
1441 * it's OK for the origin to have a single clone.
1442 */
1443 if (ds->ds_phys->ds_num_children >
1444 (dsda->is_origin_rm ? 2 : 1)) {
1445 mutex_exit(&ds->ds_lock);
1446 return (EEXIST);
1447 }
1448 mutex_exit(&ds->ds_lock);
1449 } else if (dsl_dir_is_clone(ds->ds_dir)) {
1450 return (dsl_dataset_origin_check(dsda, arg2, tx));
1451 }
1452
1453 /* XXX we should do some i/o error checking... */
1454 return (0);
1455}
1456
1457struct refsarg {
1458 kmutex_t lock;
1459 boolean_t gone;
1460 kcondvar_t cv;
1461};
1462
1463/* ARGSUSED */
1464static void
1465dsl_dataset_refs_gone(dmu_buf_t *db, void *argv)
1466{
1467 struct refsarg *arg = argv;
1468
1469 mutex_enter(&arg->lock);
1470 arg->gone = TRUE;
1471 cv_signal(&arg->cv);
1472 mutex_exit(&arg->lock);
1473}
1474
1475static void
1476dsl_dataset_drain_refs(dsl_dataset_t *ds, void *tag)
1477{
1478 struct refsarg arg;
1479
1480 bzero(&arg, sizeof(arg));
1481 mutex_init(&arg.lock, NULL, MUTEX_DEFAULT, NULL);
1482 cv_init(&arg.cv, NULL, CV_DEFAULT, NULL);
1483 arg.gone = FALSE;
1484 (void) dmu_buf_update_user(ds->ds_dbuf, ds, &arg, &ds->ds_phys,
1485 dsl_dataset_refs_gone);
1486 dmu_buf_rele(ds->ds_dbuf, tag);
1487 mutex_enter(&arg.lock);
1488 while (!arg.gone)
1489 cv_wait(&arg.cv, &arg.lock);
1490 ASSERT(arg.gone);
1491 mutex_exit(&arg.lock);
1492 ds->ds_dbuf = NULL;
1493 ds->ds_phys = NULL;
1494 mutex_destroy(&arg.lock);
1495 cv_destroy(&arg.cv);
1496}
1497
1498static void
1499remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj, dmu_tx_t *tx)
1500{
1501 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1502 uint64_t count;
1503 int err;
1504
1505 ASSERT(ds->ds_phys->ds_num_children >= 2);
1506 err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx);
1507 /*
1508 * The err should not be ENOENT, but a bug in a previous version
1509 * of the code could cause upgrade_clones_cb() to not set
1510 * ds_next_snap_obj when it should, leading to a missing entry.
1511 * If we knew that the pool was created after
1512 * SPA_VERSION_NEXT_CLONES, we could assert that it isn't
1513 * ENOENT. However, at least we can check that we don't have
1514 * too many entries in the next_clones_obj even after failing to
1515 * remove this one.
1516 */
1517 if (err != ENOENT) {
1518 VERIFY3U(err, ==, 0);
1519 }
1520 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj,
1521 &count));
1522 ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2);
1523}
1524
1525static void
1526dsl_dataset_remove_clones_key(dsl_dataset_t *ds, uint64_t mintxg, dmu_tx_t *tx)
1527{
1528 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1529 zap_cursor_t zc;
1530 zap_attribute_t za;
1531
1532 /*
1533 * If it is the old version, dd_clones doesn't exist so we can't
1534 * find the clones, but deadlist_remove_key() is a no-op so it
1535 * doesn't matter.
1536 */
1537 if (ds->ds_dir->dd_phys->dd_clones == 0)
1538 return;
1539
1540 for (zap_cursor_init(&zc, mos, ds->ds_dir->dd_phys->dd_clones);
1541 zap_cursor_retrieve(&zc, &za) == 0;
1542 zap_cursor_advance(&zc)) {
1543 dsl_dataset_t *clone;
1544
1545 VERIFY3U(0, ==, dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
1546 za.za_first_integer, FTAG, &clone));
1547 if (clone->ds_dir->dd_origin_txg > mintxg) {
1548 dsl_deadlist_remove_key(&clone->ds_deadlist,
1549 mintxg, tx);
1550 dsl_dataset_remove_clones_key(clone, mintxg, tx);
1551 }
1552 dsl_dataset_rele(clone, FTAG);
1553 }
1554 zap_cursor_fini(&zc);
1555}
1556
1557struct process_old_arg {
1558 dsl_dataset_t *ds;
1559 dsl_dataset_t *ds_prev;
1560 boolean_t after_branch_point;
1561 zio_t *pio;
1562 uint64_t used, comp, uncomp;
1563};
1564
1565static int
1566process_old_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
1567{
1568 struct process_old_arg *poa = arg;
1569 dsl_pool_t *dp = poa->ds->ds_dir->dd_pool;
1570
1571 if (bp->blk_birth <= poa->ds->ds_phys->ds_prev_snap_txg) {
1572 dsl_deadlist_insert(&poa->ds->ds_deadlist, bp, tx);
1573 if (poa->ds_prev && !poa->after_branch_point &&
1574 bp->blk_birth >
1575 poa->ds_prev->ds_phys->ds_prev_snap_txg) {
1576 poa->ds_prev->ds_phys->ds_unique_bytes +=
1577 bp_get_dsize_sync(dp->dp_spa, bp);
1578 }
1579 } else {
1580 poa->used += bp_get_dsize_sync(dp->dp_spa, bp);
1581 poa->comp += BP_GET_PSIZE(bp);
1582 poa->uncomp += BP_GET_UCSIZE(bp);
1583 dsl_free_sync(poa->pio, dp, tx->tx_txg, bp);
1584 }
1585 return (0);
1586}
1587
1588static void
1589process_old_deadlist(dsl_dataset_t *ds, dsl_dataset_t *ds_prev,
1590 dsl_dataset_t *ds_next, boolean_t after_branch_point, dmu_tx_t *tx)
1591{
1592 struct process_old_arg poa = { 0 };
1593 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1594 objset_t *mos = dp->dp_meta_objset;
1595
1596 ASSERT(ds->ds_deadlist.dl_oldfmt);
1597 ASSERT(ds_next->ds_deadlist.dl_oldfmt);
1598
1599 poa.ds = ds;
1600 poa.ds_prev = ds_prev;
1601 poa.after_branch_point = after_branch_point;
1602 poa.pio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
1603 VERIFY3U(0, ==, bpobj_iterate(&ds_next->ds_deadlist.dl_bpobj,
1604 process_old_cb, &poa, tx));
1605 VERIFY3U(zio_wait(poa.pio), ==, 0);
1606 ASSERT3U(poa.used, ==, ds->ds_phys->ds_unique_bytes);
1607
1608 /* change snapused */
1609 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
1610 -poa.used, -poa.comp, -poa.uncomp, tx);
1611
1612 /* swap next's deadlist to our deadlist */
1613 dsl_deadlist_close(&ds->ds_deadlist);
1614 dsl_deadlist_close(&ds_next->ds_deadlist);
1615 SWITCH64(ds_next->ds_phys->ds_deadlist_obj,
1616 ds->ds_phys->ds_deadlist_obj);
1617 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj);
1618 dsl_deadlist_open(&ds_next->ds_deadlist, mos,
1619 ds_next->ds_phys->ds_deadlist_obj);
1620}
1621
1622void
1623dsl_dataset_destroy_sync(void *arg1, void *tag, dmu_tx_t *tx)
1624{
1625 struct dsl_ds_destroyarg *dsda = arg1;
1626 dsl_dataset_t *ds = dsda->ds;
1627 int err;
1628 int after_branch_point = FALSE;
1629 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1630 objset_t *mos = dp->dp_meta_objset;
1631 dsl_dataset_t *ds_prev = NULL;
1632 boolean_t wont_destroy;
1633 uint64_t obj;
1634
1635 wont_destroy = (dsda->defer &&
1636 (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1));
1637
1638 ASSERT(ds->ds_owner || wont_destroy);
1639 ASSERT(dsda->defer || ds->ds_phys->ds_num_children <= 1);
1640 ASSERT(ds->ds_prev == NULL ||
1641 ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object);
1642 ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg);
1643
1644 if (wont_destroy) {
1645 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
1646 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1647 ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY;
1648 return;
1649 }
1650
1651 /* signal any waiters that this dataset is going away */
1652 mutex_enter(&ds->ds_lock);
1653 ds->ds_owner = dsl_reaper;
1654 cv_broadcast(&ds->ds_exclusive_cv);
1655 mutex_exit(&ds->ds_lock);
1656
1657 /* Remove our reservation */
1658 if (ds->ds_reserved != 0) {
1659 dsl_prop_setarg_t psa;
1660 uint64_t value = 0;
1661
1662 dsl_prop_setarg_init_uint64(&psa, "refreservation",
1663 (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED),
1664 &value);
1665 psa.psa_effective_value = 0; /* predict default value */
1666
1667 dsl_dataset_set_reservation_sync(ds, &psa, tx);
1668 ASSERT3U(ds->ds_reserved, ==, 0);
1669 }
1670
1671 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
1672
1673 dsl_scan_ds_destroyed(ds, tx);
1674
1675 obj = ds->ds_object;
1676
1677 if (ds->ds_phys->ds_prev_snap_obj != 0) {
1678 if (ds->ds_prev) {
1679 ds_prev = ds->ds_prev;
1680 } else {
1681 VERIFY(0 == dsl_dataset_hold_obj(dp,
1682 ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev));
1683 }
1684 after_branch_point =
1685 (ds_prev->ds_phys->ds_next_snap_obj != obj);
1686
1687 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx);
1688 if (after_branch_point &&
1689 ds_prev->ds_phys->ds_next_clones_obj != 0) {
1690 remove_from_next_clones(ds_prev, obj, tx);
1691 if (ds->ds_phys->ds_next_snap_obj != 0) {
1692 VERIFY(0 == zap_add_int(mos,
1693 ds_prev->ds_phys->ds_next_clones_obj,
1694 ds->ds_phys->ds_next_snap_obj, tx));
1695 }
1696 }
1697 if (after_branch_point &&
1698 ds->ds_phys->ds_next_snap_obj == 0) {
1699 /* This clone is toast. */
1700 ASSERT(ds_prev->ds_phys->ds_num_children > 1);
1701 ds_prev->ds_phys->ds_num_children--;
1702
1703 /*
1704 * If the clone's origin has no other clones, no
1705 * user holds, and has been marked for deferred
1706 * deletion, then we should have done the necessary
1707 * destroy setup for it.
1708 */
1709 if (ds_prev->ds_phys->ds_num_children == 1 &&
1710 ds_prev->ds_userrefs == 0 &&
1711 DS_IS_DEFER_DESTROY(ds_prev)) {
1712 ASSERT3P(dsda->rm_origin, !=, NULL);
1713 } else {
1714 ASSERT3P(dsda->rm_origin, ==, NULL);
1715 }
1716 } else if (!after_branch_point) {
1717 ds_prev->ds_phys->ds_next_snap_obj =
1718 ds->ds_phys->ds_next_snap_obj;
1719 }
1720 }
1721
1722 if (dsl_dataset_is_snapshot(ds)) {
1723 dsl_dataset_t *ds_next;
1724 uint64_t old_unique;
1725 uint64_t used = 0, comp = 0, uncomp = 0;
1726
1727 VERIFY(0 == dsl_dataset_hold_obj(dp,
1728 ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next));
1729 ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj);
1730
1731 old_unique = ds_next->ds_phys->ds_unique_bytes;
1732
1733 dmu_buf_will_dirty(ds_next->ds_dbuf, tx);
1734 ds_next->ds_phys->ds_prev_snap_obj =
1735 ds->ds_phys->ds_prev_snap_obj;
1736 ds_next->ds_phys->ds_prev_snap_txg =
1737 ds->ds_phys->ds_prev_snap_txg;
1738 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
1739 ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0);
1740
1741
1742 if (ds_next->ds_deadlist.dl_oldfmt) {
1743 process_old_deadlist(ds, ds_prev, ds_next,
1744 after_branch_point, tx);
1745 } else {
1746 /* Adjust prev's unique space. */
1747 if (ds_prev && !after_branch_point) {
1748 dsl_deadlist_space_range(&ds_next->ds_deadlist,
1749 ds_prev->ds_phys->ds_prev_snap_txg,
1750 ds->ds_phys->ds_prev_snap_txg,
1751 &used, &comp, &uncomp);
1752 ds_prev->ds_phys->ds_unique_bytes += used;
1753 }
1754
1755 /* Adjust snapused. */
1756 dsl_deadlist_space_range(&ds_next->ds_deadlist,
1757 ds->ds_phys->ds_prev_snap_txg, UINT64_MAX,
1758 &used, &comp, &uncomp);
1759 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
1760 -used, -comp, -uncomp, tx);
1761
1762 /* Move blocks to be freed to pool's free list. */
1763 dsl_deadlist_move_bpobj(&ds_next->ds_deadlist,
1764 &dp->dp_free_bpobj, ds->ds_phys->ds_prev_snap_txg,
1765 tx);
1766 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir,
1767 DD_USED_HEAD, used, comp, uncomp, tx);
1768 dsl_dir_dirty(tx->tx_pool->dp_free_dir, tx);
1769
1770 /* Merge our deadlist into next's and free it. */
1771 dsl_deadlist_merge(&ds_next->ds_deadlist,
1772 ds->ds_phys->ds_deadlist_obj, tx);
1773 }
1774 dsl_deadlist_close(&ds->ds_deadlist);
1775 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx);
1776
1777 /* Collapse range in clone heads */
1778 dsl_dataset_remove_clones_key(ds,
1779 ds->ds_phys->ds_creation_txg, tx);
1780
1781 if (dsl_dataset_is_snapshot(ds_next)) {
1782 dsl_dataset_t *ds_nextnext;
1783
1784 /*
1785 * Update next's unique to include blocks which
1786 * were previously shared by only this snapshot
1787 * and it. Those blocks will be born after the
1788 * prev snap and before this snap, and will have
1789 * died after the next snap and before the one
1790 * after that (ie. be on the snap after next's
1791 * deadlist).
1792 */
1793 VERIFY(0 == dsl_dataset_hold_obj(dp,
1794 ds_next->ds_phys->ds_next_snap_obj,
1795 FTAG, &ds_nextnext));
1796 dsl_deadlist_space_range(&ds_nextnext->ds_deadlist,
1797 ds->ds_phys->ds_prev_snap_txg,
1798 ds->ds_phys->ds_creation_txg,
1799 &used, &comp, &uncomp);
1800 ds_next->ds_phys->ds_unique_bytes += used;
1801 dsl_dataset_rele(ds_nextnext, FTAG);
1802 ASSERT3P(ds_next->ds_prev, ==, NULL);
1803
1804 /* Collapse range in this head. */
1805 dsl_dataset_t *hds;
1806 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
1807 ds->ds_dir->dd_phys->dd_head_dataset_obj,
1808 FTAG, &hds));
1809 dsl_deadlist_remove_key(&hds->ds_deadlist,
1810 ds->ds_phys->ds_creation_txg, tx);
1811 dsl_dataset_rele(hds, FTAG);
1812
1813 } else {
1814 ASSERT3P(ds_next->ds_prev, ==, ds);
1815 dsl_dataset_drop_ref(ds_next->ds_prev, ds_next);
1816 ds_next->ds_prev = NULL;
1817 if (ds_prev) {
1818 VERIFY(0 == dsl_dataset_get_ref(dp,
1819 ds->ds_phys->ds_prev_snap_obj,
1820 ds_next, &ds_next->ds_prev));
1821 }
1822
1823 dsl_dataset_recalc_head_uniq(ds_next);
1824
1825 /*
1826 * Reduce the amount of our unconsmed refreservation
1827 * being charged to our parent by the amount of
1828 * new unique data we have gained.
1829 */
1830 if (old_unique < ds_next->ds_reserved) {
1831 int64_t mrsdelta;
1832 uint64_t new_unique =
1833 ds_next->ds_phys->ds_unique_bytes;
1834
1835 ASSERT(old_unique <= new_unique);
1836 mrsdelta = MIN(new_unique - old_unique,
1837 ds_next->ds_reserved - old_unique);
1838 dsl_dir_diduse_space(ds->ds_dir,
1839 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx);
1840 }
1841 }
1842 dsl_dataset_rele(ds_next, FTAG);
1843 } else {
1844 /*
1845 * There's no next snapshot, so this is a head dataset.
1846 * Destroy the deadlist. Unless it's a clone, the
1847 * deadlist should be empty. (If it's a clone, it's
1848 * safe to ignore the deadlist contents.)
1849 */
1850 struct killarg ka;
1851
1852 dsl_deadlist_close(&ds->ds_deadlist);
1853 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx);
1854 ds->ds_phys->ds_deadlist_obj = 0;
1855
1856 /*
1857 * Free everything that we point to (that's born after
1858 * the previous snapshot, if we are a clone)
1859 *
1860 * NB: this should be very quick, because we already
1861 * freed all the objects in open context.
1862 */
1863 ka.ds = ds;
1864 ka.tx = tx;
1865 err = traverse_dataset(ds, ds->ds_phys->ds_prev_snap_txg,
1866 TRAVERSE_POST, kill_blkptr, &ka);
1867 ASSERT3U(err, ==, 0);
1868 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) ||
1869 ds->ds_phys->ds_unique_bytes == 0);
1870
1871 if (ds->ds_prev != NULL) {
1872 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
1873 VERIFY3U(0, ==, zap_remove_int(mos,
1874 ds->ds_prev->ds_dir->dd_phys->dd_clones,
1875 ds->ds_object, tx));
1876 }
1877 dsl_dataset_rele(ds->ds_prev, ds);
1878 ds->ds_prev = ds_prev = NULL;
1879 }
1880 }
1881
1882 /*
1883 * This must be done after the dsl_traverse(), because it will
1884 * re-open the objset.
1885 */
1886 if (ds->ds_objset) {
1887 dmu_objset_evict(ds->ds_objset);
1888 ds->ds_objset = NULL;
1889 }
1890
1891 if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) {
1892 /* Erase the link in the dir */
1893 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx);
1894 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0;
1895 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0);
1896 err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx);
1897 ASSERT(err == 0);
1898 } else {
1899 /* remove from snapshot namespace */
1900 dsl_dataset_t *ds_head;
1901 ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0);
1902 VERIFY(0 == dsl_dataset_hold_obj(dp,
1903 ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head));
1904 VERIFY(0 == dsl_dataset_get_snapname(ds));
1905#ifdef ZFS_DEBUG
1906 {
1907 uint64_t val;
1908
1909 err = dsl_dataset_snap_lookup(ds_head,
1910 ds->ds_snapname, &val);
1911 ASSERT3U(err, ==, 0);
1912 ASSERT3U(val, ==, obj);
1913 }
1914#endif
1915 err = dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx);
1916 ASSERT(err == 0);
1917 dsl_dataset_rele(ds_head, FTAG);
1918 }
1919
1920 if (ds_prev && ds->ds_prev != ds_prev)
1921 dsl_dataset_rele(ds_prev, FTAG);
1922
1923 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx);
1924 spa_history_log_internal(LOG_DS_DESTROY, dp->dp_spa, tx,
1925 "dataset = %llu", ds->ds_object);
1926
1927 if (ds->ds_phys->ds_next_clones_obj != 0) {
1928 uint64_t count;
1929 ASSERT(0 == zap_count(mos,
1930 ds->ds_phys->ds_next_clones_obj, &count) && count == 0);
1931 VERIFY(0 == dmu_object_free(mos,
1932 ds->ds_phys->ds_next_clones_obj, tx));
1933 }
1934 if (ds->ds_phys->ds_props_obj != 0)
1935 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_props_obj, tx));
1936 if (ds->ds_phys->ds_userrefs_obj != 0)
1937 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx));
1938 dsl_dir_close(ds->ds_dir, ds);
1939 ds->ds_dir = NULL;
1940 dsl_dataset_drain_refs(ds, tag);
1941 VERIFY(0 == dmu_object_free(mos, obj, tx));
1942
1943 if (dsda->rm_origin) {
1944 /*
1945 * Remove the origin of the clone we just destroyed.
1946 */
1947 struct dsl_ds_destroyarg ndsda = {0};
1948
1949 ndsda.ds = dsda->rm_origin;
1950 dsl_dataset_destroy_sync(&ndsda, tag, tx);
1951 }
1952}
1953
1954static int
1955dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx)
1956{
1957 uint64_t asize;
1958
1959 if (!dmu_tx_is_syncing(tx))
1960 return (0);
1961
1962 /*
1963 * If there's an fs-only reservation, any blocks that might become
1964 * owned by the snapshot dataset must be accommodated by space
1965 * outside of the reservation.
1966 */
1967 ASSERT(ds->ds_reserved == 0 || DS_UNIQUE_IS_ACCURATE(ds));
1968 asize = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
1969 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
1970 return (ENOSPC);
1971
1972 /*
1973 * Propogate any reserved space for this snapshot to other
1974 * snapshot checks in this sync group.
1975 */
1976 if (asize > 0)
1977 dsl_dir_willuse_space(ds->ds_dir, asize, tx);
1978
1979 return (0);
1980}
1981
1982int
1983dsl_dataset_snapshot_check(void *arg1, void *arg2, dmu_tx_t *tx)
1984{
1985 dsl_dataset_t *ds = arg1;
1986 const char *snapname = arg2;
1987 int err;
1988 uint64_t value;
1989
1990 /*
1991 * We don't allow multiple snapshots of the same txg. If there
1992 * is already one, try again.
1993 */
1994 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg)
1995 return (EAGAIN);
1996
1997 /*
1998 * Check for conflicting name snapshot name.
1999 */
2000 err = dsl_dataset_snap_lookup(ds, snapname, &value);
2001 if (err == 0)
2002 return (EEXIST);
2003 if (err != ENOENT)
2004 return (err);
2005
2006 /*
2007 * Check that the dataset's name is not too long. Name consists
2008 * of the dataset's length + 1 for the @-sign + snapshot name's length
2009 */
2010 if (dsl_dataset_namelen(ds) + 1 + strlen(snapname) >= MAXNAMELEN)
2011 return (ENAMETOOLONG);
2012
2013 err = dsl_dataset_snapshot_reserve_space(ds, tx);
2014 if (err)
2015 return (err);
2016
2017 ds->ds_trysnap_txg = tx->tx_txg;
2018 return (0);
2019}
2020
2021void
2022dsl_dataset_snapshot_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2023{
2024 dsl_dataset_t *ds = arg1;
2025 const char *snapname = arg2;
2026 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2027 dmu_buf_t *dbuf;
2028 dsl_dataset_phys_t *dsphys;
2029 uint64_t dsobj, crtxg;
2030 objset_t *mos = dp->dp_meta_objset;
2031 int err;
2032
2033 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
2034
2035 /*
2036 * The origin's ds_creation_txg has to be < TXG_INITIAL
2037 */
2038 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0)
2039 crtxg = 1;
2040 else
2041 crtxg = tx->tx_txg;
2042
2043 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
2044 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
2045 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
2046 dmu_buf_will_dirty(dbuf, tx);
2047 dsphys = dbuf->db_data;
2048 bzero(dsphys, sizeof (dsl_dataset_phys_t));
2049 dsphys->ds_dir_obj = ds->ds_dir->dd_object;
2050 dsphys->ds_fsid_guid = unique_create();
2051 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
2052 sizeof (dsphys->ds_guid));
2053 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj;
2054 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg;
2055 dsphys->ds_next_snap_obj = ds->ds_object;
2056 dsphys->ds_num_children = 1;
2057 dsphys->ds_creation_time = gethrestime_sec();
2058 dsphys->ds_creation_txg = crtxg;
2059 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj;
2060 dsphys->ds_used_bytes = ds->ds_phys->ds_used_bytes;
2061 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes;
2062 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes;
2063 dsphys->ds_flags = ds->ds_phys->ds_flags;
2064 dsphys->ds_bp = ds->ds_phys->ds_bp;
2065 dmu_buf_rele(dbuf, FTAG);
2066
2067 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0);
2068 if (ds->ds_prev) {
2069 uint64_t next_clones_obj =
2070 ds->ds_prev->ds_phys->ds_next_clones_obj;
2071 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj ==
2072 ds->ds_object ||
2073 ds->ds_prev->ds_phys->ds_num_children > 1);
2074 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) {
2075 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
2076 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
2077 ds->ds_prev->ds_phys->ds_creation_txg);
2078 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj;
2079 } else if (next_clones_obj != 0) {
2080 remove_from_next_clones(ds->ds_prev,
2081 dsphys->ds_next_snap_obj, tx);
2082 VERIFY3U(0, ==, zap_add_int(mos,
2083 next_clones_obj, dsobj, tx));
2084 }
2085 }
2086
2087 /*
2088 * If we have a reference-reservation on this dataset, we will
2089 * need to increase the amount of refreservation being charged
2090 * since our unique space is going to zero.
2091 */
2092 if (ds->ds_reserved) {
2093 int64_t delta;
2094 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
2095 delta = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
2096 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV,
2097 delta, 0, 0, tx);
2098 }
2099
2100 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2101 zfs_dbgmsg("taking snapshot %s@%s/%llu; newkey=%llu",
2102 ds->ds_dir->dd_myname, snapname, dsobj,
2103 ds->ds_phys->ds_prev_snap_txg);
2104 ds->ds_phys->ds_deadlist_obj = dsl_deadlist_clone(&ds->ds_deadlist,
2105 UINT64_MAX, ds->ds_phys->ds_prev_snap_obj, tx);
2106 dsl_deadlist_close(&ds->ds_deadlist);
2107 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj);
2108 dsl_deadlist_add_key(&ds->ds_deadlist,
2109 ds->ds_phys->ds_prev_snap_txg, tx);
2110
2111 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg);
2112 ds->ds_phys->ds_prev_snap_obj = dsobj;
2113 ds->ds_phys->ds_prev_snap_txg = crtxg;
2114 ds->ds_phys->ds_unique_bytes = 0;
2115 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
2116 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
2117
2118 err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj,
2119 snapname, 8, 1, &dsobj, tx);
2120 ASSERT(err == 0);
2121
2122 if (ds->ds_prev)
2123 dsl_dataset_drop_ref(ds->ds_prev, ds);
2124 VERIFY(0 == dsl_dataset_get_ref(dp,
2125 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev));
2126
2127 dsl_scan_ds_snapshotted(ds, tx);
2128
2129 dsl_dir_snap_cmtime_update(ds->ds_dir);
2130
2131 spa_history_log_internal(LOG_DS_SNAPSHOT, dp->dp_spa, tx,
2132 "dataset = %llu", dsobj);
2133}
2134
2135void
2136dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx)
2137{
2138 ASSERT(dmu_tx_is_syncing(tx));
2139 ASSERT(ds->ds_objset != NULL);
2140 ASSERT(ds->ds_phys->ds_next_snap_obj == 0);
2141
2142 /*
2143 * in case we had to change ds_fsid_guid when we opened it,
2144 * sync it out now.
2145 */
2146 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2147 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid;
2148
2149 dsl_dir_dirty(ds->ds_dir, tx);
2150 dmu_objset_sync(ds->ds_objset, zio, tx);
2151}
2152
| 1019}
1020
1021static boolean_t
1022dsl_dataset_might_destroy_origin(dsl_dataset_t *ds)
1023{
1024 boolean_t might_destroy = B_FALSE;
1025
1026 mutex_enter(&ds->ds_lock);
1027 if (ds->ds_phys->ds_num_children == 2 && ds->ds_userrefs == 0 &&
1028 DS_IS_DEFER_DESTROY(ds))
1029 might_destroy = B_TRUE;
1030 mutex_exit(&ds->ds_lock);
1031
1032 return (might_destroy);
1033}
1034
1035/*
1036 * If we're removing a clone, and these three conditions are true:
1037 * 1) the clone's origin has no other children
1038 * 2) the clone's origin has no user references
1039 * 3) the clone's origin has been marked for deferred destruction
1040 * Then, prepare to remove the origin as part of this sync task group.
1041 */
1042static int
1043dsl_dataset_origin_rm_prep(struct dsl_ds_destroyarg *dsda, void *tag)
1044{
1045 dsl_dataset_t *ds = dsda->ds;
1046 dsl_dataset_t *origin = ds->ds_prev;
1047
1048 if (dsl_dataset_might_destroy_origin(origin)) {
1049 char *name;
1050 int namelen;
1051 int error;
1052
1053 namelen = dsl_dataset_namelen(origin) + 1;
1054 name = kmem_alloc(namelen, KM_SLEEP);
1055 dsl_dataset_name(origin, name);
1056#ifdef _KERNEL
1057 error = zfs_unmount_snap(name, NULL);
1058 if (error) {
1059 kmem_free(name, namelen);
1060 return (error);
1061 }
1062#endif
1063 error = dsl_dataset_own(name, B_TRUE, tag, &origin);
1064 kmem_free(name, namelen);
1065 if (error)
1066 return (error);
1067 dsda->rm_origin = origin;
1068 dsl_dataset_make_exclusive(origin, tag);
1069 }
1070
1071 return (0);
1072}
1073
1074/*
1075 * ds must be opened as OWNER. On return (whether successful or not),
1076 * ds will be closed and caller can no longer dereference it.
1077 */
1078int
1079dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer)
1080{
1081 int err;
1082 dsl_sync_task_group_t *dstg;
1083 objset_t *os;
1084 dsl_dir_t *dd;
1085 uint64_t obj;
1086 struct dsl_ds_destroyarg dsda = { 0 };
1087 dsl_dataset_t dummy_ds = { 0 };
1088
1089 dsda.ds = ds;
1090
1091 if (dsl_dataset_is_snapshot(ds)) {
1092 /* Destroying a snapshot is simpler */
1093 dsl_dataset_make_exclusive(ds, tag);
1094
1095 dsda.defer = defer;
1096 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
1097 dsl_dataset_destroy_check, dsl_dataset_destroy_sync,
1098 &dsda, tag, 0);
1099 ASSERT3P(dsda.rm_origin, ==, NULL);
1100 goto out;
1101 } else if (defer) {
1102 err = EINVAL;
1103 goto out;
1104 }
1105
1106 dd = ds->ds_dir;
1107 dummy_ds.ds_dir = dd;
1108 dummy_ds.ds_object = ds->ds_object;
1109
1110 /*
1111 * Check for errors and mark this ds as inconsistent, in
1112 * case we crash while freeing the objects.
1113 */
1114 err = dsl_sync_task_do(dd->dd_pool, dsl_dataset_destroy_begin_check,
1115 dsl_dataset_destroy_begin_sync, ds, NULL, 0);
1116 if (err)
1117 goto out;
1118
1119 err = dmu_objset_from_ds(ds, &os);
1120 if (err)
1121 goto out;
1122
1123 /*
1124 * remove the objects in open context, so that we won't
1125 * have too much to do in syncing context.
1126 */
1127 for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE,
1128 ds->ds_phys->ds_prev_snap_txg)) {
1129 /*
1130 * Ignore errors, if there is not enough disk space
1131 * we will deal with it in dsl_dataset_destroy_sync().
1132 */
1133 (void) dmu_free_object(os, obj);
1134 }
1135 if (err != ESRCH)
1136 goto out;
1137
1138 /*
1139 * Only the ZIL knows how to free log blocks.
1140 */
1141 zil_destroy(dmu_objset_zil(os), B_FALSE);
1142
1143 /*
1144 * Sync out all in-flight IO.
1145 */
1146 txg_wait_synced(dd->dd_pool, 0);
1147
1148 /*
1149 * If we managed to free all the objects in open
1150 * context, the user space accounting should be zero.
1151 */
1152 if (ds->ds_phys->ds_bp.blk_fill == 0 &&
1153 dmu_objset_userused_enabled(os)) {
1154 uint64_t count;
1155
1156 ASSERT(zap_count(os, DMU_USERUSED_OBJECT, &count) != 0 ||
1157 count == 0);
1158 ASSERT(zap_count(os, DMU_GROUPUSED_OBJECT, &count) != 0 ||
1159 count == 0);
1160 }
1161
1162 rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
1163 err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd);
1164 rw_exit(&dd->dd_pool->dp_config_rwlock);
1165
1166 if (err)
1167 goto out;
1168
1169 /*
1170 * Blow away the dsl_dir + head dataset.
1171 */
1172 dsl_dataset_make_exclusive(ds, tag);
1173 /*
1174 * If we're removing a clone, we might also need to remove its
1175 * origin.
1176 */
1177 do {
1178 dsda.need_prep = B_FALSE;
1179 if (dsl_dir_is_clone(dd)) {
1180 err = dsl_dataset_origin_rm_prep(&dsda, tag);
1181 if (err) {
1182 dsl_dir_close(dd, FTAG);
1183 goto out;
1184 }
1185 }
1186
1187 dstg = dsl_sync_task_group_create(ds->ds_dir->dd_pool);
1188 dsl_sync_task_create(dstg, dsl_dataset_destroy_check,
1189 dsl_dataset_destroy_sync, &dsda, tag, 0);
1190 dsl_sync_task_create(dstg, dsl_dir_destroy_check,
1191 dsl_dir_destroy_sync, &dummy_ds, FTAG, 0);
1192 err = dsl_sync_task_group_wait(dstg);
1193 dsl_sync_task_group_destroy(dstg);
1194
1195 /*
1196 * We could be racing against 'zfs release' or 'zfs destroy -d'
1197 * on the origin snap, in which case we can get EBUSY if we
1198 * needed to destroy the origin snap but were not ready to
1199 * do so.
1200 */
1201 if (dsda.need_prep) {
1202 ASSERT(err == EBUSY);
1203 ASSERT(dsl_dir_is_clone(dd));
1204 ASSERT(dsda.rm_origin == NULL);
1205 }
1206 } while (dsda.need_prep);
1207
1208 if (dsda.rm_origin != NULL)
1209 dsl_dataset_disown(dsda.rm_origin, tag);
1210
1211 /* if it is successful, dsl_dir_destroy_sync will close the dd */
1212 if (err)
1213 dsl_dir_close(dd, FTAG);
1214out:
1215 dsl_dataset_disown(ds, tag);
1216 return (err);
1217}
1218
1219blkptr_t *
1220dsl_dataset_get_blkptr(dsl_dataset_t *ds)
1221{
1222 return (&ds->ds_phys->ds_bp);
1223}
1224
1225void
1226dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx)
1227{
1228 ASSERT(dmu_tx_is_syncing(tx));
1229 /* If it's the meta-objset, set dp_meta_rootbp */
1230 if (ds == NULL) {
1231 tx->tx_pool->dp_meta_rootbp = *bp;
1232 } else {
1233 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1234 ds->ds_phys->ds_bp = *bp;
1235 }
1236}
1237
1238spa_t *
1239dsl_dataset_get_spa(dsl_dataset_t *ds)
1240{
1241 return (ds->ds_dir->dd_pool->dp_spa);
1242}
1243
1244void
1245dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx)
1246{
1247 dsl_pool_t *dp;
1248
1249 if (ds == NULL) /* this is the meta-objset */
1250 return;
1251
1252 ASSERT(ds->ds_objset != NULL);
1253
1254 if (ds->ds_phys->ds_next_snap_obj != 0)
1255 panic("dirtying snapshot!");
1256
1257 dp = ds->ds_dir->dd_pool;
1258
1259 if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg) == 0) {
1260 /* up the hold count until we can be written out */
1261 dmu_buf_add_ref(ds->ds_dbuf, ds);
1262 }
1263}
1264
1265/*
1266 * The unique space in the head dataset can be calculated by subtracting
1267 * the space used in the most recent snapshot, that is still being used
1268 * in this file system, from the space currently in use. To figure out
1269 * the space in the most recent snapshot still in use, we need to take
1270 * the total space used in the snapshot and subtract out the space that
1271 * has been freed up since the snapshot was taken.
1272 */
1273static void
1274dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds)
1275{
1276 uint64_t mrs_used;
1277 uint64_t dlused, dlcomp, dluncomp;
1278
1279 ASSERT(!dsl_dataset_is_snapshot(ds));
1280
1281 if (ds->ds_phys->ds_prev_snap_obj != 0)
1282 mrs_used = ds->ds_prev->ds_phys->ds_used_bytes;
1283 else
1284 mrs_used = 0;
1285
1286 dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp);
1287
1288 ASSERT3U(dlused, <=, mrs_used);
1289 ds->ds_phys->ds_unique_bytes =
1290 ds->ds_phys->ds_used_bytes - (mrs_used - dlused);
1291
1292 if (spa_version(ds->ds_dir->dd_pool->dp_spa) >=
1293 SPA_VERSION_UNIQUE_ACCURATE)
1294 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
1295}
1296
1297struct killarg {
1298 dsl_dataset_t *ds;
1299 dmu_tx_t *tx;
1300};
1301
1302/* ARGSUSED */
1303static int
1304kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf,
1305 const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
1306{
1307 struct killarg *ka = arg;
1308 dmu_tx_t *tx = ka->tx;
1309
1310 if (bp == NULL)
1311 return (0);
1312
1313 if (zb->zb_level == ZB_ZIL_LEVEL) {
1314 ASSERT(zilog != NULL);
1315 /*
1316 * It's a block in the intent log. It has no
1317 * accounting, so just free it.
1318 */
1319 dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp);
1320 } else {
1321 ASSERT(zilog == NULL);
1322 ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg);
1323 (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE);
1324 }
1325
1326 return (0);
1327}
1328
1329/* ARGSUSED */
1330static int
1331dsl_dataset_destroy_begin_check(void *arg1, void *arg2, dmu_tx_t *tx)
1332{
1333 dsl_dataset_t *ds = arg1;
1334 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1335 uint64_t count;
1336 int err;
1337
1338 /*
1339 * Can't delete a head dataset if there are snapshots of it.
1340 * (Except if the only snapshots are from the branch we cloned
1341 * from.)
1342 */
1343 if (ds->ds_prev != NULL &&
1344 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object)
1345 return (EBUSY);
1346
1347 /*
1348 * This is really a dsl_dir thing, but check it here so that
1349 * we'll be less likely to leave this dataset inconsistent &
1350 * nearly destroyed.
1351 */
1352 err = zap_count(mos, ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count);
1353 if (err)
1354 return (err);
1355 if (count != 0)
1356 return (EEXIST);
1357
1358 return (0);
1359}
1360
1361/* ARGSUSED */
1362static void
1363dsl_dataset_destroy_begin_sync(void *arg1, void *arg2, dmu_tx_t *tx)
1364{
1365 dsl_dataset_t *ds = arg1;
1366 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1367
1368 /* Mark it as inconsistent on-disk, in case we crash */
1369 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1370 ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT;
1371
1372 spa_history_log_internal(LOG_DS_DESTROY_BEGIN, dp->dp_spa, tx,
1373 "dataset = %llu", ds->ds_object);
1374}
1375
1376static int
1377dsl_dataset_origin_check(struct dsl_ds_destroyarg *dsda, void *tag,
1378 dmu_tx_t *tx)
1379{
1380 dsl_dataset_t *ds = dsda->ds;
1381 dsl_dataset_t *ds_prev = ds->ds_prev;
1382
1383 if (dsl_dataset_might_destroy_origin(ds_prev)) {
1384 struct dsl_ds_destroyarg ndsda = {0};
1385
1386 /*
1387 * If we're not prepared to remove the origin, don't remove
1388 * the clone either.
1389 */
1390 if (dsda->rm_origin == NULL) {
1391 dsda->need_prep = B_TRUE;
1392 return (EBUSY);
1393 }
1394
1395 ndsda.ds = ds_prev;
1396 ndsda.is_origin_rm = B_TRUE;
1397 return (dsl_dataset_destroy_check(&ndsda, tag, tx));
1398 }
1399
1400 /*
1401 * If we're not going to remove the origin after all,
1402 * undo the open context setup.
1403 */
1404 if (dsda->rm_origin != NULL) {
1405 dsl_dataset_disown(dsda->rm_origin, tag);
1406 dsda->rm_origin = NULL;
1407 }
1408
1409 return (0);
1410}
1411
1412/*
1413 * If you add new checks here, you may need to add
1414 * additional checks to the "temporary" case in
1415 * snapshot_check() in dmu_objset.c.
1416 */
1417/* ARGSUSED */
1418int
1419dsl_dataset_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx)
1420{
1421 struct dsl_ds_destroyarg *dsda = arg1;
1422 dsl_dataset_t *ds = dsda->ds;
1423
1424 /* we have an owner hold, so noone else can destroy us */
1425 ASSERT(!DSL_DATASET_IS_DESTROYED(ds));
1426
1427 /*
1428 * Only allow deferred destroy on pools that support it.
1429 * NOTE: deferred destroy is only supported on snapshots.
1430 */
1431 if (dsda->defer) {
1432 if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
1433 SPA_VERSION_USERREFS)
1434 return (ENOTSUP);
1435 ASSERT(dsl_dataset_is_snapshot(ds));
1436 return (0);
1437 }
1438
1439 /*
1440 * Can't delete a head dataset if there are snapshots of it.
1441 * (Except if the only snapshots are from the branch we cloned
1442 * from.)
1443 */
1444 if (ds->ds_prev != NULL &&
1445 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object)
1446 return (EBUSY);
1447
1448 /*
1449 * If we made changes this txg, traverse_dsl_dataset won't find
1450 * them. Try again.
1451 */
1452 if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg)
1453 return (EAGAIN);
1454
1455 if (dsl_dataset_is_snapshot(ds)) {
1456 /*
1457 * If this snapshot has an elevated user reference count,
1458 * we can't destroy it yet.
1459 */
1460 if (ds->ds_userrefs > 0 && !dsda->releasing)
1461 return (EBUSY);
1462
1463 mutex_enter(&ds->ds_lock);
1464 /*
1465 * Can't delete a branch point. However, if we're destroying
1466 * a clone and removing its origin due to it having a user
1467 * hold count of 0 and having been marked for deferred destroy,
1468 * it's OK for the origin to have a single clone.
1469 */
1470 if (ds->ds_phys->ds_num_children >
1471 (dsda->is_origin_rm ? 2 : 1)) {
1472 mutex_exit(&ds->ds_lock);
1473 return (EEXIST);
1474 }
1475 mutex_exit(&ds->ds_lock);
1476 } else if (dsl_dir_is_clone(ds->ds_dir)) {
1477 return (dsl_dataset_origin_check(dsda, arg2, tx));
1478 }
1479
1480 /* XXX we should do some i/o error checking... */
1481 return (0);
1482}
1483
1484struct refsarg {
1485 kmutex_t lock;
1486 boolean_t gone;
1487 kcondvar_t cv;
1488};
1489
1490/* ARGSUSED */
1491static void
1492dsl_dataset_refs_gone(dmu_buf_t *db, void *argv)
1493{
1494 struct refsarg *arg = argv;
1495
1496 mutex_enter(&arg->lock);
1497 arg->gone = TRUE;
1498 cv_signal(&arg->cv);
1499 mutex_exit(&arg->lock);
1500}
1501
1502static void
1503dsl_dataset_drain_refs(dsl_dataset_t *ds, void *tag)
1504{
1505 struct refsarg arg;
1506
1507 bzero(&arg, sizeof(arg));
1508 mutex_init(&arg.lock, NULL, MUTEX_DEFAULT, NULL);
1509 cv_init(&arg.cv, NULL, CV_DEFAULT, NULL);
1510 arg.gone = FALSE;
1511 (void) dmu_buf_update_user(ds->ds_dbuf, ds, &arg, &ds->ds_phys,
1512 dsl_dataset_refs_gone);
1513 dmu_buf_rele(ds->ds_dbuf, tag);
1514 mutex_enter(&arg.lock);
1515 while (!arg.gone)
1516 cv_wait(&arg.cv, &arg.lock);
1517 ASSERT(arg.gone);
1518 mutex_exit(&arg.lock);
1519 ds->ds_dbuf = NULL;
1520 ds->ds_phys = NULL;
1521 mutex_destroy(&arg.lock);
1522 cv_destroy(&arg.cv);
1523}
1524
1525static void
1526remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj, dmu_tx_t *tx)
1527{
1528 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1529 uint64_t count;
1530 int err;
1531
1532 ASSERT(ds->ds_phys->ds_num_children >= 2);
1533 err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx);
1534 /*
1535 * The err should not be ENOENT, but a bug in a previous version
1536 * of the code could cause upgrade_clones_cb() to not set
1537 * ds_next_snap_obj when it should, leading to a missing entry.
1538 * If we knew that the pool was created after
1539 * SPA_VERSION_NEXT_CLONES, we could assert that it isn't
1540 * ENOENT. However, at least we can check that we don't have
1541 * too many entries in the next_clones_obj even after failing to
1542 * remove this one.
1543 */
1544 if (err != ENOENT) {
1545 VERIFY3U(err, ==, 0);
1546 }
1547 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj,
1548 &count));
1549 ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2);
1550}
1551
1552static void
1553dsl_dataset_remove_clones_key(dsl_dataset_t *ds, uint64_t mintxg, dmu_tx_t *tx)
1554{
1555 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1556 zap_cursor_t zc;
1557 zap_attribute_t za;
1558
1559 /*
1560 * If it is the old version, dd_clones doesn't exist so we can't
1561 * find the clones, but deadlist_remove_key() is a no-op so it
1562 * doesn't matter.
1563 */
1564 if (ds->ds_dir->dd_phys->dd_clones == 0)
1565 return;
1566
1567 for (zap_cursor_init(&zc, mos, ds->ds_dir->dd_phys->dd_clones);
1568 zap_cursor_retrieve(&zc, &za) == 0;
1569 zap_cursor_advance(&zc)) {
1570 dsl_dataset_t *clone;
1571
1572 VERIFY3U(0, ==, dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
1573 za.za_first_integer, FTAG, &clone));
1574 if (clone->ds_dir->dd_origin_txg > mintxg) {
1575 dsl_deadlist_remove_key(&clone->ds_deadlist,
1576 mintxg, tx);
1577 dsl_dataset_remove_clones_key(clone, mintxg, tx);
1578 }
1579 dsl_dataset_rele(clone, FTAG);
1580 }
1581 zap_cursor_fini(&zc);
1582}
1583
1584struct process_old_arg {
1585 dsl_dataset_t *ds;
1586 dsl_dataset_t *ds_prev;
1587 boolean_t after_branch_point;
1588 zio_t *pio;
1589 uint64_t used, comp, uncomp;
1590};
1591
1592static int
1593process_old_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
1594{
1595 struct process_old_arg *poa = arg;
1596 dsl_pool_t *dp = poa->ds->ds_dir->dd_pool;
1597
1598 if (bp->blk_birth <= poa->ds->ds_phys->ds_prev_snap_txg) {
1599 dsl_deadlist_insert(&poa->ds->ds_deadlist, bp, tx);
1600 if (poa->ds_prev && !poa->after_branch_point &&
1601 bp->blk_birth >
1602 poa->ds_prev->ds_phys->ds_prev_snap_txg) {
1603 poa->ds_prev->ds_phys->ds_unique_bytes +=
1604 bp_get_dsize_sync(dp->dp_spa, bp);
1605 }
1606 } else {
1607 poa->used += bp_get_dsize_sync(dp->dp_spa, bp);
1608 poa->comp += BP_GET_PSIZE(bp);
1609 poa->uncomp += BP_GET_UCSIZE(bp);
1610 dsl_free_sync(poa->pio, dp, tx->tx_txg, bp);
1611 }
1612 return (0);
1613}
1614
1615static void
1616process_old_deadlist(dsl_dataset_t *ds, dsl_dataset_t *ds_prev,
1617 dsl_dataset_t *ds_next, boolean_t after_branch_point, dmu_tx_t *tx)
1618{
1619 struct process_old_arg poa = { 0 };
1620 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1621 objset_t *mos = dp->dp_meta_objset;
1622
1623 ASSERT(ds->ds_deadlist.dl_oldfmt);
1624 ASSERT(ds_next->ds_deadlist.dl_oldfmt);
1625
1626 poa.ds = ds;
1627 poa.ds_prev = ds_prev;
1628 poa.after_branch_point = after_branch_point;
1629 poa.pio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
1630 VERIFY3U(0, ==, bpobj_iterate(&ds_next->ds_deadlist.dl_bpobj,
1631 process_old_cb, &poa, tx));
1632 VERIFY3U(zio_wait(poa.pio), ==, 0);
1633 ASSERT3U(poa.used, ==, ds->ds_phys->ds_unique_bytes);
1634
1635 /* change snapused */
1636 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
1637 -poa.used, -poa.comp, -poa.uncomp, tx);
1638
1639 /* swap next's deadlist to our deadlist */
1640 dsl_deadlist_close(&ds->ds_deadlist);
1641 dsl_deadlist_close(&ds_next->ds_deadlist);
1642 SWITCH64(ds_next->ds_phys->ds_deadlist_obj,
1643 ds->ds_phys->ds_deadlist_obj);
1644 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj);
1645 dsl_deadlist_open(&ds_next->ds_deadlist, mos,
1646 ds_next->ds_phys->ds_deadlist_obj);
1647}
1648
1649void
1650dsl_dataset_destroy_sync(void *arg1, void *tag, dmu_tx_t *tx)
1651{
1652 struct dsl_ds_destroyarg *dsda = arg1;
1653 dsl_dataset_t *ds = dsda->ds;
1654 int err;
1655 int after_branch_point = FALSE;
1656 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1657 objset_t *mos = dp->dp_meta_objset;
1658 dsl_dataset_t *ds_prev = NULL;
1659 boolean_t wont_destroy;
1660 uint64_t obj;
1661
1662 wont_destroy = (dsda->defer &&
1663 (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1));
1664
1665 ASSERT(ds->ds_owner || wont_destroy);
1666 ASSERT(dsda->defer || ds->ds_phys->ds_num_children <= 1);
1667 ASSERT(ds->ds_prev == NULL ||
1668 ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object);
1669 ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg);
1670
1671 if (wont_destroy) {
1672 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
1673 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1674 ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY;
1675 return;
1676 }
1677
1678 /* signal any waiters that this dataset is going away */
1679 mutex_enter(&ds->ds_lock);
1680 ds->ds_owner = dsl_reaper;
1681 cv_broadcast(&ds->ds_exclusive_cv);
1682 mutex_exit(&ds->ds_lock);
1683
1684 /* Remove our reservation */
1685 if (ds->ds_reserved != 0) {
1686 dsl_prop_setarg_t psa;
1687 uint64_t value = 0;
1688
1689 dsl_prop_setarg_init_uint64(&psa, "refreservation",
1690 (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED),
1691 &value);
1692 psa.psa_effective_value = 0; /* predict default value */
1693
1694 dsl_dataset_set_reservation_sync(ds, &psa, tx);
1695 ASSERT3U(ds->ds_reserved, ==, 0);
1696 }
1697
1698 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
1699
1700 dsl_scan_ds_destroyed(ds, tx);
1701
1702 obj = ds->ds_object;
1703
1704 if (ds->ds_phys->ds_prev_snap_obj != 0) {
1705 if (ds->ds_prev) {
1706 ds_prev = ds->ds_prev;
1707 } else {
1708 VERIFY(0 == dsl_dataset_hold_obj(dp,
1709 ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev));
1710 }
1711 after_branch_point =
1712 (ds_prev->ds_phys->ds_next_snap_obj != obj);
1713
1714 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx);
1715 if (after_branch_point &&
1716 ds_prev->ds_phys->ds_next_clones_obj != 0) {
1717 remove_from_next_clones(ds_prev, obj, tx);
1718 if (ds->ds_phys->ds_next_snap_obj != 0) {
1719 VERIFY(0 == zap_add_int(mos,
1720 ds_prev->ds_phys->ds_next_clones_obj,
1721 ds->ds_phys->ds_next_snap_obj, tx));
1722 }
1723 }
1724 if (after_branch_point &&
1725 ds->ds_phys->ds_next_snap_obj == 0) {
1726 /* This clone is toast. */
1727 ASSERT(ds_prev->ds_phys->ds_num_children > 1);
1728 ds_prev->ds_phys->ds_num_children--;
1729
1730 /*
1731 * If the clone's origin has no other clones, no
1732 * user holds, and has been marked for deferred
1733 * deletion, then we should have done the necessary
1734 * destroy setup for it.
1735 */
1736 if (ds_prev->ds_phys->ds_num_children == 1 &&
1737 ds_prev->ds_userrefs == 0 &&
1738 DS_IS_DEFER_DESTROY(ds_prev)) {
1739 ASSERT3P(dsda->rm_origin, !=, NULL);
1740 } else {
1741 ASSERT3P(dsda->rm_origin, ==, NULL);
1742 }
1743 } else if (!after_branch_point) {
1744 ds_prev->ds_phys->ds_next_snap_obj =
1745 ds->ds_phys->ds_next_snap_obj;
1746 }
1747 }
1748
1749 if (dsl_dataset_is_snapshot(ds)) {
1750 dsl_dataset_t *ds_next;
1751 uint64_t old_unique;
1752 uint64_t used = 0, comp = 0, uncomp = 0;
1753
1754 VERIFY(0 == dsl_dataset_hold_obj(dp,
1755 ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next));
1756 ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj);
1757
1758 old_unique = ds_next->ds_phys->ds_unique_bytes;
1759
1760 dmu_buf_will_dirty(ds_next->ds_dbuf, tx);
1761 ds_next->ds_phys->ds_prev_snap_obj =
1762 ds->ds_phys->ds_prev_snap_obj;
1763 ds_next->ds_phys->ds_prev_snap_txg =
1764 ds->ds_phys->ds_prev_snap_txg;
1765 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
1766 ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0);
1767
1768
1769 if (ds_next->ds_deadlist.dl_oldfmt) {
1770 process_old_deadlist(ds, ds_prev, ds_next,
1771 after_branch_point, tx);
1772 } else {
1773 /* Adjust prev's unique space. */
1774 if (ds_prev && !after_branch_point) {
1775 dsl_deadlist_space_range(&ds_next->ds_deadlist,
1776 ds_prev->ds_phys->ds_prev_snap_txg,
1777 ds->ds_phys->ds_prev_snap_txg,
1778 &used, &comp, &uncomp);
1779 ds_prev->ds_phys->ds_unique_bytes += used;
1780 }
1781
1782 /* Adjust snapused. */
1783 dsl_deadlist_space_range(&ds_next->ds_deadlist,
1784 ds->ds_phys->ds_prev_snap_txg, UINT64_MAX,
1785 &used, &comp, &uncomp);
1786 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
1787 -used, -comp, -uncomp, tx);
1788
1789 /* Move blocks to be freed to pool's free list. */
1790 dsl_deadlist_move_bpobj(&ds_next->ds_deadlist,
1791 &dp->dp_free_bpobj, ds->ds_phys->ds_prev_snap_txg,
1792 tx);
1793 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir,
1794 DD_USED_HEAD, used, comp, uncomp, tx);
1795 dsl_dir_dirty(tx->tx_pool->dp_free_dir, tx);
1796
1797 /* Merge our deadlist into next's and free it. */
1798 dsl_deadlist_merge(&ds_next->ds_deadlist,
1799 ds->ds_phys->ds_deadlist_obj, tx);
1800 }
1801 dsl_deadlist_close(&ds->ds_deadlist);
1802 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx);
1803
1804 /* Collapse range in clone heads */
1805 dsl_dataset_remove_clones_key(ds,
1806 ds->ds_phys->ds_creation_txg, tx);
1807
1808 if (dsl_dataset_is_snapshot(ds_next)) {
1809 dsl_dataset_t *ds_nextnext;
1810
1811 /*
1812 * Update next's unique to include blocks which
1813 * were previously shared by only this snapshot
1814 * and it. Those blocks will be born after the
1815 * prev snap and before this snap, and will have
1816 * died after the next snap and before the one
1817 * after that (ie. be on the snap after next's
1818 * deadlist).
1819 */
1820 VERIFY(0 == dsl_dataset_hold_obj(dp,
1821 ds_next->ds_phys->ds_next_snap_obj,
1822 FTAG, &ds_nextnext));
1823 dsl_deadlist_space_range(&ds_nextnext->ds_deadlist,
1824 ds->ds_phys->ds_prev_snap_txg,
1825 ds->ds_phys->ds_creation_txg,
1826 &used, &comp, &uncomp);
1827 ds_next->ds_phys->ds_unique_bytes += used;
1828 dsl_dataset_rele(ds_nextnext, FTAG);
1829 ASSERT3P(ds_next->ds_prev, ==, NULL);
1830
1831 /* Collapse range in this head. */
1832 dsl_dataset_t *hds;
1833 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
1834 ds->ds_dir->dd_phys->dd_head_dataset_obj,
1835 FTAG, &hds));
1836 dsl_deadlist_remove_key(&hds->ds_deadlist,
1837 ds->ds_phys->ds_creation_txg, tx);
1838 dsl_dataset_rele(hds, FTAG);
1839
1840 } else {
1841 ASSERT3P(ds_next->ds_prev, ==, ds);
1842 dsl_dataset_drop_ref(ds_next->ds_prev, ds_next);
1843 ds_next->ds_prev = NULL;
1844 if (ds_prev) {
1845 VERIFY(0 == dsl_dataset_get_ref(dp,
1846 ds->ds_phys->ds_prev_snap_obj,
1847 ds_next, &ds_next->ds_prev));
1848 }
1849
1850 dsl_dataset_recalc_head_uniq(ds_next);
1851
1852 /*
1853 * Reduce the amount of our unconsmed refreservation
1854 * being charged to our parent by the amount of
1855 * new unique data we have gained.
1856 */
1857 if (old_unique < ds_next->ds_reserved) {
1858 int64_t mrsdelta;
1859 uint64_t new_unique =
1860 ds_next->ds_phys->ds_unique_bytes;
1861
1862 ASSERT(old_unique <= new_unique);
1863 mrsdelta = MIN(new_unique - old_unique,
1864 ds_next->ds_reserved - old_unique);
1865 dsl_dir_diduse_space(ds->ds_dir,
1866 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx);
1867 }
1868 }
1869 dsl_dataset_rele(ds_next, FTAG);
1870 } else {
1871 /*
1872 * There's no next snapshot, so this is a head dataset.
1873 * Destroy the deadlist. Unless it's a clone, the
1874 * deadlist should be empty. (If it's a clone, it's
1875 * safe to ignore the deadlist contents.)
1876 */
1877 struct killarg ka;
1878
1879 dsl_deadlist_close(&ds->ds_deadlist);
1880 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx);
1881 ds->ds_phys->ds_deadlist_obj = 0;
1882
1883 /*
1884 * Free everything that we point to (that's born after
1885 * the previous snapshot, if we are a clone)
1886 *
1887 * NB: this should be very quick, because we already
1888 * freed all the objects in open context.
1889 */
1890 ka.ds = ds;
1891 ka.tx = tx;
1892 err = traverse_dataset(ds, ds->ds_phys->ds_prev_snap_txg,
1893 TRAVERSE_POST, kill_blkptr, &ka);
1894 ASSERT3U(err, ==, 0);
1895 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) ||
1896 ds->ds_phys->ds_unique_bytes == 0);
1897
1898 if (ds->ds_prev != NULL) {
1899 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
1900 VERIFY3U(0, ==, zap_remove_int(mos,
1901 ds->ds_prev->ds_dir->dd_phys->dd_clones,
1902 ds->ds_object, tx));
1903 }
1904 dsl_dataset_rele(ds->ds_prev, ds);
1905 ds->ds_prev = ds_prev = NULL;
1906 }
1907 }
1908
1909 /*
1910 * This must be done after the dsl_traverse(), because it will
1911 * re-open the objset.
1912 */
1913 if (ds->ds_objset) {
1914 dmu_objset_evict(ds->ds_objset);
1915 ds->ds_objset = NULL;
1916 }
1917
1918 if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) {
1919 /* Erase the link in the dir */
1920 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx);
1921 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0;
1922 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0);
1923 err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx);
1924 ASSERT(err == 0);
1925 } else {
1926 /* remove from snapshot namespace */
1927 dsl_dataset_t *ds_head;
1928 ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0);
1929 VERIFY(0 == dsl_dataset_hold_obj(dp,
1930 ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head));
1931 VERIFY(0 == dsl_dataset_get_snapname(ds));
1932#ifdef ZFS_DEBUG
1933 {
1934 uint64_t val;
1935
1936 err = dsl_dataset_snap_lookup(ds_head,
1937 ds->ds_snapname, &val);
1938 ASSERT3U(err, ==, 0);
1939 ASSERT3U(val, ==, obj);
1940 }
1941#endif
1942 err = dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx);
1943 ASSERT(err == 0);
1944 dsl_dataset_rele(ds_head, FTAG);
1945 }
1946
1947 if (ds_prev && ds->ds_prev != ds_prev)
1948 dsl_dataset_rele(ds_prev, FTAG);
1949
1950 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx);
1951 spa_history_log_internal(LOG_DS_DESTROY, dp->dp_spa, tx,
1952 "dataset = %llu", ds->ds_object);
1953
1954 if (ds->ds_phys->ds_next_clones_obj != 0) {
1955 uint64_t count;
1956 ASSERT(0 == zap_count(mos,
1957 ds->ds_phys->ds_next_clones_obj, &count) && count == 0);
1958 VERIFY(0 == dmu_object_free(mos,
1959 ds->ds_phys->ds_next_clones_obj, tx));
1960 }
1961 if (ds->ds_phys->ds_props_obj != 0)
1962 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_props_obj, tx));
1963 if (ds->ds_phys->ds_userrefs_obj != 0)
1964 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx));
1965 dsl_dir_close(ds->ds_dir, ds);
1966 ds->ds_dir = NULL;
1967 dsl_dataset_drain_refs(ds, tag);
1968 VERIFY(0 == dmu_object_free(mos, obj, tx));
1969
1970 if (dsda->rm_origin) {
1971 /*
1972 * Remove the origin of the clone we just destroyed.
1973 */
1974 struct dsl_ds_destroyarg ndsda = {0};
1975
1976 ndsda.ds = dsda->rm_origin;
1977 dsl_dataset_destroy_sync(&ndsda, tag, tx);
1978 }
1979}
1980
1981static int
1982dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx)
1983{
1984 uint64_t asize;
1985
1986 if (!dmu_tx_is_syncing(tx))
1987 return (0);
1988
1989 /*
1990 * If there's an fs-only reservation, any blocks that might become
1991 * owned by the snapshot dataset must be accommodated by space
1992 * outside of the reservation.
1993 */
1994 ASSERT(ds->ds_reserved == 0 || DS_UNIQUE_IS_ACCURATE(ds));
1995 asize = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
1996 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
1997 return (ENOSPC);
1998
1999 /*
2000 * Propogate any reserved space for this snapshot to other
2001 * snapshot checks in this sync group.
2002 */
2003 if (asize > 0)
2004 dsl_dir_willuse_space(ds->ds_dir, asize, tx);
2005
2006 return (0);
2007}
2008
2009int
2010dsl_dataset_snapshot_check(void *arg1, void *arg2, dmu_tx_t *tx)
2011{
2012 dsl_dataset_t *ds = arg1;
2013 const char *snapname = arg2;
2014 int err;
2015 uint64_t value;
2016
2017 /*
2018 * We don't allow multiple snapshots of the same txg. If there
2019 * is already one, try again.
2020 */
2021 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg)
2022 return (EAGAIN);
2023
2024 /*
2025 * Check for conflicting name snapshot name.
2026 */
2027 err = dsl_dataset_snap_lookup(ds, snapname, &value);
2028 if (err == 0)
2029 return (EEXIST);
2030 if (err != ENOENT)
2031 return (err);
2032
2033 /*
2034 * Check that the dataset's name is not too long. Name consists
2035 * of the dataset's length + 1 for the @-sign + snapshot name's length
2036 */
2037 if (dsl_dataset_namelen(ds) + 1 + strlen(snapname) >= MAXNAMELEN)
2038 return (ENAMETOOLONG);
2039
2040 err = dsl_dataset_snapshot_reserve_space(ds, tx);
2041 if (err)
2042 return (err);
2043
2044 ds->ds_trysnap_txg = tx->tx_txg;
2045 return (0);
2046}
2047
2048void
2049dsl_dataset_snapshot_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2050{
2051 dsl_dataset_t *ds = arg1;
2052 const char *snapname = arg2;
2053 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2054 dmu_buf_t *dbuf;
2055 dsl_dataset_phys_t *dsphys;
2056 uint64_t dsobj, crtxg;
2057 objset_t *mos = dp->dp_meta_objset;
2058 int err;
2059
2060 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
2061
2062 /*
2063 * The origin's ds_creation_txg has to be < TXG_INITIAL
2064 */
2065 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0)
2066 crtxg = 1;
2067 else
2068 crtxg = tx->tx_txg;
2069
2070 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
2071 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
2072 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
2073 dmu_buf_will_dirty(dbuf, tx);
2074 dsphys = dbuf->db_data;
2075 bzero(dsphys, sizeof (dsl_dataset_phys_t));
2076 dsphys->ds_dir_obj = ds->ds_dir->dd_object;
2077 dsphys->ds_fsid_guid = unique_create();
2078 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
2079 sizeof (dsphys->ds_guid));
2080 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj;
2081 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg;
2082 dsphys->ds_next_snap_obj = ds->ds_object;
2083 dsphys->ds_num_children = 1;
2084 dsphys->ds_creation_time = gethrestime_sec();
2085 dsphys->ds_creation_txg = crtxg;
2086 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj;
2087 dsphys->ds_used_bytes = ds->ds_phys->ds_used_bytes;
2088 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes;
2089 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes;
2090 dsphys->ds_flags = ds->ds_phys->ds_flags;
2091 dsphys->ds_bp = ds->ds_phys->ds_bp;
2092 dmu_buf_rele(dbuf, FTAG);
2093
2094 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0);
2095 if (ds->ds_prev) {
2096 uint64_t next_clones_obj =
2097 ds->ds_prev->ds_phys->ds_next_clones_obj;
2098 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj ==
2099 ds->ds_object ||
2100 ds->ds_prev->ds_phys->ds_num_children > 1);
2101 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) {
2102 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
2103 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
2104 ds->ds_prev->ds_phys->ds_creation_txg);
2105 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj;
2106 } else if (next_clones_obj != 0) {
2107 remove_from_next_clones(ds->ds_prev,
2108 dsphys->ds_next_snap_obj, tx);
2109 VERIFY3U(0, ==, zap_add_int(mos,
2110 next_clones_obj, dsobj, tx));
2111 }
2112 }
2113
2114 /*
2115 * If we have a reference-reservation on this dataset, we will
2116 * need to increase the amount of refreservation being charged
2117 * since our unique space is going to zero.
2118 */
2119 if (ds->ds_reserved) {
2120 int64_t delta;
2121 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
2122 delta = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
2123 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV,
2124 delta, 0, 0, tx);
2125 }
2126
2127 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2128 zfs_dbgmsg("taking snapshot %s@%s/%llu; newkey=%llu",
2129 ds->ds_dir->dd_myname, snapname, dsobj,
2130 ds->ds_phys->ds_prev_snap_txg);
2131 ds->ds_phys->ds_deadlist_obj = dsl_deadlist_clone(&ds->ds_deadlist,
2132 UINT64_MAX, ds->ds_phys->ds_prev_snap_obj, tx);
2133 dsl_deadlist_close(&ds->ds_deadlist);
2134 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj);
2135 dsl_deadlist_add_key(&ds->ds_deadlist,
2136 ds->ds_phys->ds_prev_snap_txg, tx);
2137
2138 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg);
2139 ds->ds_phys->ds_prev_snap_obj = dsobj;
2140 ds->ds_phys->ds_prev_snap_txg = crtxg;
2141 ds->ds_phys->ds_unique_bytes = 0;
2142 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
2143 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
2144
2145 err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj,
2146 snapname, 8, 1, &dsobj, tx);
2147 ASSERT(err == 0);
2148
2149 if (ds->ds_prev)
2150 dsl_dataset_drop_ref(ds->ds_prev, ds);
2151 VERIFY(0 == dsl_dataset_get_ref(dp,
2152 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev));
2153
2154 dsl_scan_ds_snapshotted(ds, tx);
2155
2156 dsl_dir_snap_cmtime_update(ds->ds_dir);
2157
2158 spa_history_log_internal(LOG_DS_SNAPSHOT, dp->dp_spa, tx,
2159 "dataset = %llu", dsobj);
2160}
2161
2162void
2163dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx)
2164{
2165 ASSERT(dmu_tx_is_syncing(tx));
2166 ASSERT(ds->ds_objset != NULL);
2167 ASSERT(ds->ds_phys->ds_next_snap_obj == 0);
2168
2169 /*
2170 * in case we had to change ds_fsid_guid when we opened it,
2171 * sync it out now.
2172 */
2173 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2174 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid;
2175
2176 dsl_dir_dirty(ds->ds_dir, tx);
2177 dmu_objset_sync(ds->ds_objset, zio, tx);
2178}
2179
|
| 2180static void
2181get_clones_stat(dsl_dataset_t *ds, nvlist_t *nv)
2182{
2183 uint64_t count = 0;
2184 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
2185 zap_cursor_t zc;
2186 zap_attribute_t za;
2187 nvlist_t *propval;
2188 nvlist_t *val;
2189
2190 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER);
2191 VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2192 VERIFY(nvlist_alloc(&val, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2193
2194 /*
2195 * There may me missing entries in ds_next_clones_obj
2196 * due to a bug in a previous version of the code.
2197 * Only trust it if it has the right number of entries.
2198 */
2199 if (ds->ds_phys->ds_next_clones_obj != 0) {
2200 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj,
2201 &count));
2202 }
2203 if (count != ds->ds_phys->ds_num_children - 1) {
2204 goto fail;
2205 }
2206 for (zap_cursor_init(&zc, mos, ds->ds_phys->ds_next_clones_obj);
2207 zap_cursor_retrieve(&zc, &za) == 0;
2208 zap_cursor_advance(&zc)) {
2209 dsl_dataset_t *clone;
2210 char buf[ZFS_MAXNAMELEN];
2211 if (dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
2212 za.za_first_integer, FTAG, &clone) != 0) {
2213 goto fail;
2214 }
2215 dsl_dir_name(clone->ds_dir, buf);
2216 VERIFY(nvlist_add_boolean(val, buf) == 0);
2217 dsl_dataset_rele(clone, FTAG);
2218 }
2219 zap_cursor_fini(&zc);
2220 VERIFY(nvlist_add_nvlist(propval, ZPROP_VALUE, val) == 0);
2221 VERIFY(nvlist_add_nvlist(nv, zfs_prop_to_name(ZFS_PROP_CLONES),
2222 propval) == 0);
2223fail:
2224 nvlist_free(val);
2225 nvlist_free(propval);
2226 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock);
2227}
2228
|
2153void
2154dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv)
2155{
2156 uint64_t refd, avail, uobjs, aobjs, ratio;
2157
2158 dsl_dir_stats(ds->ds_dir, nv);
2159
2160 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs);
2161 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail);
2162 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd);
2163
2164 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION,
2165 ds->ds_phys->ds_creation_time);
2166 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG,
2167 ds->ds_phys->ds_creation_txg);
2168 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA,
2169 ds->ds_quota);
2170 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION,
2171 ds->ds_reserved);
2172 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID,
2173 ds->ds_phys->ds_guid);
2174 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE,
2175 ds->ds_phys->ds_unique_bytes);
2176 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID,
2177 ds->ds_object);
2178 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS,
2179 ds->ds_userrefs);
2180 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY,
2181 DS_IS_DEFER_DESTROY(ds) ? 1 : 0);
2182
| 2229void
2230dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv)
2231{
2232 uint64_t refd, avail, uobjs, aobjs, ratio;
2233
2234 dsl_dir_stats(ds->ds_dir, nv);
2235
2236 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs);
2237 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail);
2238 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd);
2239
2240 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION,
2241 ds->ds_phys->ds_creation_time);
2242 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG,
2243 ds->ds_phys->ds_creation_txg);
2244 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA,
2245 ds->ds_quota);
2246 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION,
2247 ds->ds_reserved);
2248 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID,
2249 ds->ds_phys->ds_guid);
2250 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE,
2251 ds->ds_phys->ds_unique_bytes);
2252 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID,
2253 ds->ds_object);
2254 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS,
2255 ds->ds_userrefs);
2256 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY,
2257 DS_IS_DEFER_DESTROY(ds) ? 1 : 0);
2258
|
| 2259 if (ds->ds_phys->ds_prev_snap_obj != 0) {
2260 uint64_t written, comp, uncomp;
2261 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2262 dsl_dataset_t *prev;
2263
2264 rw_enter(&dp->dp_config_rwlock, RW_READER);
2265 int err = dsl_dataset_hold_obj(dp,
2266 ds->ds_phys->ds_prev_snap_obj, FTAG, &prev);
2267 rw_exit(&dp->dp_config_rwlock);
2268 if (err == 0) {
2269 err = dsl_dataset_space_written(prev, ds, &written,
2270 &comp, &uncomp);
2271 dsl_dataset_rele(prev, FTAG);
2272 if (err == 0) {
2273 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_WRITTEN,
2274 written);
2275 }
2276 }
2277 }
2278
|
2183 ratio = ds->ds_phys->ds_compressed_bytes == 0 ? 100 :
2184 (ds->ds_phys->ds_uncompressed_bytes * 100 /
2185 ds->ds_phys->ds_compressed_bytes);
2186 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRATIO, ratio);
2187
2188 if (ds->ds_phys->ds_next_snap_obj) {
2189 /*
2190 * This is a snapshot; override the dd's space used with
2191 * our unique space and compression ratio.
2192 */
2193 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED,
2194 ds->ds_phys->ds_unique_bytes);
2195 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, ratio);
| 2279 ratio = ds->ds_phys->ds_compressed_bytes == 0 ? 100 :
2280 (ds->ds_phys->ds_uncompressed_bytes * 100 /
2281 ds->ds_phys->ds_compressed_bytes);
2282 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRATIO, ratio);
2283
2284 if (ds->ds_phys->ds_next_snap_obj) {
2285 /*
2286 * This is a snapshot; override the dd's space used with
2287 * our unique space and compression ratio.
2288 */
2289 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED,
2290 ds->ds_phys->ds_unique_bytes);
2291 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, ratio);
|
| 2292
2293 get_clones_stat(ds, nv);
|
2196 }
2197}
2198
2199void
2200dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat)
2201{
2202 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg;
2203 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT;
2204 stat->dds_guid = ds->ds_phys->ds_guid;
2205 if (ds->ds_phys->ds_next_snap_obj) {
2206 stat->dds_is_snapshot = B_TRUE;
2207 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1;
2208 } else {
2209 stat->dds_is_snapshot = B_FALSE;
2210 stat->dds_num_clones = 0;
2211 }
2212
2213 /* clone origin is really a dsl_dir thing... */
2214 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER);
2215 if (dsl_dir_is_clone(ds->ds_dir)) {
2216 dsl_dataset_t *ods;
2217
2218 VERIFY(0 == dsl_dataset_get_ref(ds->ds_dir->dd_pool,
2219 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods));
2220 dsl_dataset_name(ods, stat->dds_origin);
2221 dsl_dataset_drop_ref(ods, FTAG);
2222 } else {
2223 stat->dds_origin[0] = '\0';
2224 }
2225 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock);
2226}
2227
2228uint64_t
2229dsl_dataset_fsid_guid(dsl_dataset_t *ds)
2230{
2231 return (ds->ds_fsid_guid);
2232}
2233
2234void
2235dsl_dataset_space(dsl_dataset_t *ds,
2236 uint64_t *refdbytesp, uint64_t *availbytesp,
2237 uint64_t *usedobjsp, uint64_t *availobjsp)
2238{
2239 *refdbytesp = ds->ds_phys->ds_used_bytes;
2240 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE);
2241 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes)
2242 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes;
2243 if (ds->ds_quota != 0) {
2244 /*
2245 * Adjust available bytes according to refquota
2246 */
2247 if (*refdbytesp < ds->ds_quota)
2248 *availbytesp = MIN(*availbytesp,
2249 ds->ds_quota - *refdbytesp);
2250 else
2251 *availbytesp = 0;
2252 }
2253 *usedobjsp = ds->ds_phys->ds_bp.blk_fill;
2254 *availobjsp = DN_MAX_OBJECT - *usedobjsp;
2255}
2256
2257boolean_t
2258dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds)
2259{
2260 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2261
2262 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) ||
2263 dsl_pool_sync_context(dp));
2264 if (ds->ds_prev == NULL)
2265 return (B_FALSE);
2266 if (ds->ds_phys->ds_bp.blk_birth >
2267 ds->ds_prev->ds_phys->ds_creation_txg) {
2268 objset_t *os, *os_prev;
2269 /*
2270 * It may be that only the ZIL differs, because it was
2271 * reset in the head. Don't count that as being
2272 * modified.
2273 */
2274 if (dmu_objset_from_ds(ds, &os) != 0)
2275 return (B_TRUE);
2276 if (dmu_objset_from_ds(ds->ds_prev, &os_prev) != 0)
2277 return (B_TRUE);
2278 return (bcmp(&os->os_phys->os_meta_dnode,
2279 &os_prev->os_phys->os_meta_dnode,
2280 sizeof (os->os_phys->os_meta_dnode)) != 0);
2281 }
2282 return (B_FALSE);
2283}
2284
2285/* ARGSUSED */
2286static int
2287dsl_dataset_snapshot_rename_check(void *arg1, void *arg2, dmu_tx_t *tx)
2288{
2289 dsl_dataset_t *ds = arg1;
2290 char *newsnapname = arg2;
2291 dsl_dir_t *dd = ds->ds_dir;
2292 dsl_dataset_t *hds;
2293 uint64_t val;
2294 int err;
2295
2296 err = dsl_dataset_hold_obj(dd->dd_pool,
2297 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds);
2298 if (err)
2299 return (err);
2300
2301 /* new name better not be in use */
2302 err = dsl_dataset_snap_lookup(hds, newsnapname, &val);
2303 dsl_dataset_rele(hds, FTAG);
2304
2305 if (err == 0)
2306 err = EEXIST;
2307 else if (err == ENOENT)
2308 err = 0;
2309
2310 /* dataset name + 1 for the "@" + the new snapshot name must fit */
2311 if (dsl_dir_namelen(ds->ds_dir) + 1 + strlen(newsnapname) >= MAXNAMELEN)
2312 err = ENAMETOOLONG;
2313
2314 return (err);
2315}
2316
2317static void
2318dsl_dataset_snapshot_rename_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2319{
2320 char oldname[MAXPATHLEN], newname[MAXPATHLEN];
2321 dsl_dataset_t *ds = arg1;
2322 const char *newsnapname = arg2;
2323 dsl_dir_t *dd = ds->ds_dir;
2324 objset_t *mos = dd->dd_pool->dp_meta_objset;
2325 dsl_dataset_t *hds;
2326 int err;
2327
2328 ASSERT(ds->ds_phys->ds_next_snap_obj != 0);
2329
2330 VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool,
2331 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds));
2332
2333 VERIFY(0 == dsl_dataset_get_snapname(ds));
2334 err = dsl_dataset_snap_remove(hds, ds->ds_snapname, tx);
2335 ASSERT3U(err, ==, 0);
2336 dsl_dataset_name(ds, oldname);
2337 mutex_enter(&ds->ds_lock);
2338 (void) strcpy(ds->ds_snapname, newsnapname);
2339 mutex_exit(&ds->ds_lock);
2340 err = zap_add(mos, hds->ds_phys->ds_snapnames_zapobj,
2341 ds->ds_snapname, 8, 1, &ds->ds_object, tx);
2342 ASSERT3U(err, ==, 0);
2343 dsl_dataset_name(ds, newname);
2344#ifdef _KERNEL
2345 zvol_rename_minors(oldname, newname);
2346#endif
2347
2348 spa_history_log_internal(LOG_DS_RENAME, dd->dd_pool->dp_spa, tx,
2349 "dataset = %llu", ds->ds_object);
2350 dsl_dataset_rele(hds, FTAG);
2351}
2352
2353struct renamesnaparg {
2354 dsl_sync_task_group_t *dstg;
2355 char failed[MAXPATHLEN];
2356 char *oldsnap;
2357 char *newsnap;
2358};
2359
2360static int
2361dsl_snapshot_rename_one(const char *name, void *arg)
2362{
2363 struct renamesnaparg *ra = arg;
2364 dsl_dataset_t *ds = NULL;
2365 char *snapname;
2366 int err;
2367
2368 snapname = kmem_asprintf("%s@%s", name, ra->oldsnap);
2369 (void) strlcpy(ra->failed, snapname, sizeof (ra->failed));
2370
2371 /*
2372 * For recursive snapshot renames the parent won't be changing
2373 * so we just pass name for both the to/from argument.
2374 */
2375 err = zfs_secpolicy_rename_perms(snapname, snapname, CRED());
2376 if (err != 0) {
2377 strfree(snapname);
2378 return (err == ENOENT ? 0 : err);
2379 }
2380
2381#ifdef _KERNEL
2382 /*
2383 * For all filesystems undergoing rename, we'll need to unmount it.
2384 */
2385 (void) zfs_unmount_snap(snapname, NULL);
2386#endif
2387 err = dsl_dataset_hold(snapname, ra->dstg, &ds);
2388 strfree(snapname);
2389 if (err != 0)
2390 return (err == ENOENT ? 0 : err);
2391
2392 dsl_sync_task_create(ra->dstg, dsl_dataset_snapshot_rename_check,
2393 dsl_dataset_snapshot_rename_sync, ds, ra->newsnap, 0);
2394
2395 return (0);
2396}
2397
2398static int
2399dsl_recursive_rename(char *oldname, const char *newname)
2400{
2401 int err;
2402 struct renamesnaparg *ra;
2403 dsl_sync_task_t *dst;
2404 spa_t *spa;
2405 char *cp, *fsname = spa_strdup(oldname);
2406 int len = strlen(oldname) + 1;
2407
2408 /* truncate the snapshot name to get the fsname */
2409 cp = strchr(fsname, '@');
2410 *cp = '\0';
2411
2412 err = spa_open(fsname, &spa, FTAG);
2413 if (err) {
2414 kmem_free(fsname, len);
2415 return (err);
2416 }
2417 ra = kmem_alloc(sizeof (struct renamesnaparg), KM_SLEEP);
2418 ra->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
2419
2420 ra->oldsnap = strchr(oldname, '@') + 1;
2421 ra->newsnap = strchr(newname, '@') + 1;
2422 *ra->failed = '\0';
2423
2424 err = dmu_objset_find(fsname, dsl_snapshot_rename_one, ra,
2425 DS_FIND_CHILDREN);
2426 kmem_free(fsname, len);
2427
2428 if (err == 0) {
2429 err = dsl_sync_task_group_wait(ra->dstg);
2430 }
2431
2432 for (dst = list_head(&ra->dstg->dstg_tasks); dst;
2433 dst = list_next(&ra->dstg->dstg_tasks, dst)) {
2434 dsl_dataset_t *ds = dst->dst_arg1;
2435 if (dst->dst_err) {
2436 dsl_dir_name(ds->ds_dir, ra->failed);
2437 (void) strlcat(ra->failed, "@", sizeof (ra->failed));
2438 (void) strlcat(ra->failed, ra->newsnap,
2439 sizeof (ra->failed));
2440 }
2441 dsl_dataset_rele(ds, ra->dstg);
2442 }
2443
2444 if (err)
2445 (void) strlcpy(oldname, ra->failed, sizeof (ra->failed));
2446
2447 dsl_sync_task_group_destroy(ra->dstg);
2448 kmem_free(ra, sizeof (struct renamesnaparg));
2449 spa_close(spa, FTAG);
2450 return (err);
2451}
2452
2453static int
2454dsl_valid_rename(const char *oldname, void *arg)
2455{
2456 int delta = *(int *)arg;
2457
2458 if (strlen(oldname) + delta >= MAXNAMELEN)
2459 return (ENAMETOOLONG);
2460
2461 return (0);
2462}
2463
2464#pragma weak dmu_objset_rename = dsl_dataset_rename
2465int
2466dsl_dataset_rename(char *oldname, const char *newname, int flags)
2467{
2468 dsl_dir_t *dd;
2469 dsl_dataset_t *ds;
2470 const char *tail;
2471 int err;
2472
2473 err = dsl_dir_open(oldname, FTAG, &dd, &tail);
2474 if (err)
2475 return (err);
2476
2477 if (tail == NULL) {
2478 int delta = strlen(newname) - strlen(oldname);
2479
2480 /* if we're growing, validate child name lengths */
2481 if (delta > 0)
2482 err = dmu_objset_find(oldname, dsl_valid_rename,
2483 &delta, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS);
2484
2485 if (err == 0)
2486 err = dsl_dir_rename(dd, newname, flags);
2487 dsl_dir_close(dd, FTAG);
2488 return (err);
2489 }
2490
2491 if (tail[0] != '@') {
2492 /* the name ended in a nonexistent component */
2493 dsl_dir_close(dd, FTAG);
2494 return (ENOENT);
2495 }
2496
2497 dsl_dir_close(dd, FTAG);
2498
2499 /* new name must be snapshot in same filesystem */
2500 tail = strchr(newname, '@');
2501 if (tail == NULL)
2502 return (EINVAL);
2503 tail++;
2504 if (strncmp(oldname, newname, tail - newname) != 0)
2505 return (EXDEV);
2506
2507 if (flags & ZFS_RENAME_RECURSIVE) {
2508 err = dsl_recursive_rename(oldname, newname);
2509 } else {
2510 err = dsl_dataset_hold(oldname, FTAG, &ds);
2511 if (err)
2512 return (err);
2513
2514 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
2515 dsl_dataset_snapshot_rename_check,
2516 dsl_dataset_snapshot_rename_sync, ds, (char *)tail, 1);
2517
2518 dsl_dataset_rele(ds, FTAG);
2519 }
2520
2521 return (err);
2522}
2523
2524struct promotenode {
2525 list_node_t link;
2526 dsl_dataset_t *ds;
2527};
2528
2529struct promotearg {
2530 list_t shared_snaps, origin_snaps, clone_snaps;
2531 dsl_dataset_t *origin_origin;
2532 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap;
2533 char *err_ds;
2534};
2535
2536static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep);
2537static boolean_t snaplist_unstable(list_t *l);
2538
2539static int
2540dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx)
2541{
2542 dsl_dataset_t *hds = arg1;
2543 struct promotearg *pa = arg2;
2544 struct promotenode *snap = list_head(&pa->shared_snaps);
2545 dsl_dataset_t *origin_ds = snap->ds;
2546 int err;
2547 uint64_t unused;
2548
2549 /* Check that it is a real clone */
2550 if (!dsl_dir_is_clone(hds->ds_dir))
2551 return (EINVAL);
2552
2553 /* Since this is so expensive, don't do the preliminary check */
2554 if (!dmu_tx_is_syncing(tx))
2555 return (0);
2556
2557 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE)
2558 return (EXDEV);
2559
2560 /* compute origin's new unique space */
2561 snap = list_tail(&pa->clone_snaps);
2562 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2563 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2564 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX,
2565 &pa->unique, &unused, &unused);
2566
2567 /*
2568 * Walk the snapshots that we are moving
2569 *
2570 * Compute space to transfer. Consider the incremental changes
2571 * to used for each snapshot:
2572 * (my used) = (prev's used) + (blocks born) - (blocks killed)
2573 * So each snapshot gave birth to:
2574 * (blocks born) = (my used) - (prev's used) + (blocks killed)
2575 * So a sequence would look like:
2576 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0)
2577 * Which simplifies to:
2578 * uN + kN + kN-1 + ... + k1 + k0
2579 * Note however, if we stop before we reach the ORIGIN we get:
2580 * uN + kN + kN-1 + ... + kM - uM-1
2581 */
2582 pa->used = origin_ds->ds_phys->ds_used_bytes;
2583 pa->comp = origin_ds->ds_phys->ds_compressed_bytes;
2584 pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes;
2585 for (snap = list_head(&pa->shared_snaps); snap;
2586 snap = list_next(&pa->shared_snaps, snap)) {
2587 uint64_t val, dlused, dlcomp, dluncomp;
2588 dsl_dataset_t *ds = snap->ds;
2589
2590 /* Check that the snapshot name does not conflict */
2591 VERIFY(0 == dsl_dataset_get_snapname(ds));
2592 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val);
2593 if (err == 0) {
2594 err = EEXIST;
2595 goto out;
2596 }
2597 if (err != ENOENT)
2598 goto out;
2599
2600 /* The very first snapshot does not have a deadlist */
2601 if (ds->ds_phys->ds_prev_snap_obj == 0)
2602 continue;
2603
2604 dsl_deadlist_space(&ds->ds_deadlist,
2605 &dlused, &dlcomp, &dluncomp);
2606 pa->used += dlused;
2607 pa->comp += dlcomp;
2608 pa->uncomp += dluncomp;
2609 }
2610
2611 /*
2612 * If we are a clone of a clone then we never reached ORIGIN,
2613 * so we need to subtract out the clone origin's used space.
2614 */
2615 if (pa->origin_origin) {
2616 pa->used -= pa->origin_origin->ds_phys->ds_used_bytes;
2617 pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes;
2618 pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes;
2619 }
2620
2621 /* Check that there is enough space here */
2622 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir,
2623 pa->used);
2624 if (err)
2625 return (err);
2626
2627 /*
2628 * Compute the amounts of space that will be used by snapshots
2629 * after the promotion (for both origin and clone). For each,
2630 * it is the amount of space that will be on all of their
2631 * deadlists (that was not born before their new origin).
2632 */
2633 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2634 uint64_t space;
2635
2636 /*
2637 * Note, typically this will not be a clone of a clone,
2638 * so dd_origin_txg will be < TXG_INITIAL, so
2639 * these snaplist_space() -> dsl_deadlist_space_range()
2640 * calls will be fast because they do not have to
2641 * iterate over all bps.
2642 */
2643 snap = list_head(&pa->origin_snaps);
2644 err = snaplist_space(&pa->shared_snaps,
2645 snap->ds->ds_dir->dd_origin_txg, &pa->cloneusedsnap);
2646 if (err)
2647 return (err);
2648
2649 err = snaplist_space(&pa->clone_snaps,
2650 snap->ds->ds_dir->dd_origin_txg, &space);
2651 if (err)
2652 return (err);
2653 pa->cloneusedsnap += space;
2654 }
2655 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2656 err = snaplist_space(&pa->origin_snaps,
2657 origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap);
2658 if (err)
2659 return (err);
2660 }
2661
2662 return (0);
2663out:
2664 pa->err_ds = snap->ds->ds_snapname;
2665 return (err);
2666}
2667
2668static void
2669dsl_dataset_promote_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2670{
2671 dsl_dataset_t *hds = arg1;
2672 struct promotearg *pa = arg2;
2673 struct promotenode *snap = list_head(&pa->shared_snaps);
2674 dsl_dataset_t *origin_ds = snap->ds;
2675 dsl_dataset_t *origin_head;
2676 dsl_dir_t *dd = hds->ds_dir;
2677 dsl_pool_t *dp = hds->ds_dir->dd_pool;
2678 dsl_dir_t *odd = NULL;
2679 uint64_t oldnext_obj;
2680 int64_t delta;
2681
2682 ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE));
2683
2684 snap = list_head(&pa->origin_snaps);
2685 origin_head = snap->ds;
2686
2687 /*
2688 * We need to explicitly open odd, since origin_ds's dd will be
2689 * changing.
2690 */
2691 VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object,
2692 NULL, FTAG, &odd));
2693
2694 /* change origin's next snap */
2695 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx);
2696 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj;
2697 snap = list_tail(&pa->clone_snaps);
2698 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2699 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object;
2700
2701 /* change the origin's next clone */
2702 if (origin_ds->ds_phys->ds_next_clones_obj) {
2703 remove_from_next_clones(origin_ds, snap->ds->ds_object, tx);
2704 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2705 origin_ds->ds_phys->ds_next_clones_obj,
2706 oldnext_obj, tx));
2707 }
2708
2709 /* change origin */
2710 dmu_buf_will_dirty(dd->dd_dbuf, tx);
2711 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object);
2712 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj;
2713 dd->dd_origin_txg = origin_head->ds_dir->dd_origin_txg;
2714 dmu_buf_will_dirty(odd->dd_dbuf, tx);
2715 odd->dd_phys->dd_origin_obj = origin_ds->ds_object;
2716 origin_head->ds_dir->dd_origin_txg =
2717 origin_ds->ds_phys->ds_creation_txg;
2718
2719 /* change dd_clone entries */
2720 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2721 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
2722 odd->dd_phys->dd_clones, hds->ds_object, tx));
2723 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2724 pa->origin_origin->ds_dir->dd_phys->dd_clones,
2725 hds->ds_object, tx));
2726
2727 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
2728 pa->origin_origin->ds_dir->dd_phys->dd_clones,
2729 origin_head->ds_object, tx));
2730 if (dd->dd_phys->dd_clones == 0) {
2731 dd->dd_phys->dd_clones = zap_create(dp->dp_meta_objset,
2732 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
2733 }
2734 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2735 dd->dd_phys->dd_clones, origin_head->ds_object, tx));
2736
2737 }
2738
2739 /* move snapshots to this dir */
2740 for (snap = list_head(&pa->shared_snaps); snap;
2741 snap = list_next(&pa->shared_snaps, snap)) {
2742 dsl_dataset_t *ds = snap->ds;
2743
2744 /* unregister props as dsl_dir is changing */
2745 if (ds->ds_objset) {
2746 dmu_objset_evict(ds->ds_objset);
2747 ds->ds_objset = NULL;
2748 }
2749 /* move snap name entry */
2750 VERIFY(0 == dsl_dataset_get_snapname(ds));
2751 VERIFY(0 == dsl_dataset_snap_remove(origin_head,
2752 ds->ds_snapname, tx));
2753 VERIFY(0 == zap_add(dp->dp_meta_objset,
2754 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname,
2755 8, 1, &ds->ds_object, tx));
2756
2757 /* change containing dsl_dir */
2758 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2759 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object);
2760 ds->ds_phys->ds_dir_obj = dd->dd_object;
2761 ASSERT3P(ds->ds_dir, ==, odd);
2762 dsl_dir_close(ds->ds_dir, ds);
2763 VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object,
2764 NULL, ds, &ds->ds_dir));
2765
2766 /* move any clone references */
2767 if (ds->ds_phys->ds_next_clones_obj &&
2768 spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2769 zap_cursor_t zc;
2770 zap_attribute_t za;
2771
2772 for (zap_cursor_init(&zc, dp->dp_meta_objset,
2773 ds->ds_phys->ds_next_clones_obj);
2774 zap_cursor_retrieve(&zc, &za) == 0;
2775 zap_cursor_advance(&zc)) {
2776 dsl_dataset_t *cnds;
2777 uint64_t o;
2778
2779 if (za.za_first_integer == oldnext_obj) {
2780 /*
2781 * We've already moved the
2782 * origin's reference.
2783 */
2784 continue;
2785 }
2786
2787 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
2788 za.za_first_integer, FTAG, &cnds));
2789 o = cnds->ds_dir->dd_phys->dd_head_dataset_obj;
2790
2791 VERIFY3U(zap_remove_int(dp->dp_meta_objset,
2792 odd->dd_phys->dd_clones, o, tx), ==, 0);
2793 VERIFY3U(zap_add_int(dp->dp_meta_objset,
2794 dd->dd_phys->dd_clones, o, tx), ==, 0);
2795 dsl_dataset_rele(cnds, FTAG);
2796 }
2797 zap_cursor_fini(&zc);
2798 }
2799
2800 ASSERT3U(dsl_prop_numcb(ds), ==, 0);
2801 }
2802
2803 /*
2804 * Change space accounting.
2805 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either
2806 * both be valid, or both be 0 (resulting in delta == 0). This
2807 * is true for each of {clone,origin} independently.
2808 */
2809
2810 delta = pa->cloneusedsnap -
2811 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2812 ASSERT3S(delta, >=, 0);
2813 ASSERT3U(pa->used, >=, delta);
2814 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx);
2815 dsl_dir_diduse_space(dd, DD_USED_HEAD,
2816 pa->used - delta, pa->comp, pa->uncomp, tx);
2817
2818 delta = pa->originusedsnap -
2819 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2820 ASSERT3S(delta, <=, 0);
2821 ASSERT3U(pa->used, >=, -delta);
2822 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx);
2823 dsl_dir_diduse_space(odd, DD_USED_HEAD,
2824 -pa->used - delta, -pa->comp, -pa->uncomp, tx);
2825
2826 origin_ds->ds_phys->ds_unique_bytes = pa->unique;
2827
2828 /* log history record */
2829 spa_history_log_internal(LOG_DS_PROMOTE, dd->dd_pool->dp_spa, tx,
2830 "dataset = %llu", hds->ds_object);
2831
2832 dsl_dir_close(odd, FTAG);
2833}
2834
2835static char *snaplist_tag = "snaplist";
2836/*
2837 * Make a list of dsl_dataset_t's for the snapshots between first_obj
2838 * (exclusive) and last_obj (inclusive). The list will be in reverse
2839 * order (last_obj will be the list_head()). If first_obj == 0, do all
2840 * snapshots back to this dataset's origin.
2841 */
2842static int
2843snaplist_make(dsl_pool_t *dp, boolean_t own,
2844 uint64_t first_obj, uint64_t last_obj, list_t *l)
2845{
2846 uint64_t obj = last_obj;
2847
2848 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock));
2849
2850 list_create(l, sizeof (struct promotenode),
2851 offsetof(struct promotenode, link));
2852
2853 while (obj != first_obj) {
2854 dsl_dataset_t *ds;
2855 struct promotenode *snap;
2856 int err;
2857
2858 if (own) {
2859 err = dsl_dataset_own_obj(dp, obj,
2860 0, snaplist_tag, &ds);
2861 if (err == 0)
2862 dsl_dataset_make_exclusive(ds, snaplist_tag);
2863 } else {
2864 err = dsl_dataset_hold_obj(dp, obj, snaplist_tag, &ds);
2865 }
2866 if (err == ENOENT) {
2867 /* lost race with snapshot destroy */
2868 struct promotenode *last = list_tail(l);
2869 ASSERT(obj != last->ds->ds_phys->ds_prev_snap_obj);
2870 obj = last->ds->ds_phys->ds_prev_snap_obj;
2871 continue;
2872 } else if (err) {
2873 return (err);
2874 }
2875
2876 if (first_obj == 0)
2877 first_obj = ds->ds_dir->dd_phys->dd_origin_obj;
2878
2879 snap = kmem_alloc(sizeof (struct promotenode), KM_SLEEP);
2880 snap->ds = ds;
2881 list_insert_tail(l, snap);
2882 obj = ds->ds_phys->ds_prev_snap_obj;
2883 }
2884
2885 return (0);
2886}
2887
2888static int
2889snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep)
2890{
2891 struct promotenode *snap;
2892
2893 *spacep = 0;
2894 for (snap = list_head(l); snap; snap = list_next(l, snap)) {
2895 uint64_t used, comp, uncomp;
2896 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2897 mintxg, UINT64_MAX, &used, &comp, &uncomp);
2898 *spacep += used;
2899 }
2900 return (0);
2901}
2902
2903static void
2904snaplist_destroy(list_t *l, boolean_t own)
2905{
2906 struct promotenode *snap;
2907
2908 if (!l || !list_link_active(&l->list_head))
2909 return;
2910
2911 while ((snap = list_tail(l)) != NULL) {
2912 list_remove(l, snap);
2913 if (own)
2914 dsl_dataset_disown(snap->ds, snaplist_tag);
2915 else
2916 dsl_dataset_rele(snap->ds, snaplist_tag);
2917 kmem_free(snap, sizeof (struct promotenode));
2918 }
2919 list_destroy(l);
2920}
2921
2922/*
2923 * Promote a clone. Nomenclature note:
2924 * "clone" or "cds": the original clone which is being promoted
2925 * "origin" or "ods": the snapshot which is originally clone's origin
2926 * "origin head" or "ohds": the dataset which is the head
2927 * (filesystem/volume) for the origin
2928 * "origin origin": the origin of the origin's filesystem (typically
2929 * NULL, indicating that the clone is not a clone of a clone).
2930 */
2931int
2932dsl_dataset_promote(const char *name, char *conflsnap)
2933{
2934 dsl_dataset_t *ds;
2935 dsl_dir_t *dd;
2936 dsl_pool_t *dp;
2937 dmu_object_info_t doi;
2938 struct promotearg pa = { 0 };
2939 struct promotenode *snap;
2940 int err;
2941
2942 err = dsl_dataset_hold(name, FTAG, &ds);
2943 if (err)
2944 return (err);
2945 dd = ds->ds_dir;
2946 dp = dd->dd_pool;
2947
2948 err = dmu_object_info(dp->dp_meta_objset,
2949 ds->ds_phys->ds_snapnames_zapobj, &doi);
2950 if (err) {
2951 dsl_dataset_rele(ds, FTAG);
2952 return (err);
2953 }
2954
2955 if (dsl_dataset_is_snapshot(ds) || dd->dd_phys->dd_origin_obj == 0) {
2956 dsl_dataset_rele(ds, FTAG);
2957 return (EINVAL);
2958 }
2959
2960 /*
2961 * We are going to inherit all the snapshots taken before our
2962 * origin (i.e., our new origin will be our parent's origin).
2963 * Take ownership of them so that we can rename them into our
2964 * namespace.
2965 */
2966 rw_enter(&dp->dp_config_rwlock, RW_READER);
2967
2968 err = snaplist_make(dp, B_TRUE, 0, dd->dd_phys->dd_origin_obj,
2969 &pa.shared_snaps);
2970 if (err != 0)
2971 goto out;
2972
2973 err = snaplist_make(dp, B_FALSE, 0, ds->ds_object, &pa.clone_snaps);
2974 if (err != 0)
2975 goto out;
2976
2977 snap = list_head(&pa.shared_snaps);
2978 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj);
2979 err = snaplist_make(dp, B_FALSE, dd->dd_phys->dd_origin_obj,
2980 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj, &pa.origin_snaps);
2981 if (err != 0)
2982 goto out;
2983
2984 if (snap->ds->ds_dir->dd_phys->dd_origin_obj != 0) {
2985 err = dsl_dataset_hold_obj(dp,
2986 snap->ds->ds_dir->dd_phys->dd_origin_obj,
2987 FTAG, &pa.origin_origin);
2988 if (err != 0)
2989 goto out;
2990 }
2991
2992out:
2993 rw_exit(&dp->dp_config_rwlock);
2994
2995 /*
2996 * Add in 128x the snapnames zapobj size, since we will be moving
2997 * a bunch of snapnames to the promoted ds, and dirtying their
2998 * bonus buffers.
2999 */
3000 if (err == 0) {
3001 err = dsl_sync_task_do(dp, dsl_dataset_promote_check,
3002 dsl_dataset_promote_sync, ds, &pa,
3003 2 + 2 * doi.doi_physical_blocks_512);
3004 if (err && pa.err_ds && conflsnap)
3005 (void) strncpy(conflsnap, pa.err_ds, MAXNAMELEN);
3006 }
3007
3008 snaplist_destroy(&pa.shared_snaps, B_TRUE);
3009 snaplist_destroy(&pa.clone_snaps, B_FALSE);
3010 snaplist_destroy(&pa.origin_snaps, B_FALSE);
3011 if (pa.origin_origin)
3012 dsl_dataset_rele(pa.origin_origin, FTAG);
3013 dsl_dataset_rele(ds, FTAG);
3014 return (err);
3015}
3016
3017struct cloneswaparg {
3018 dsl_dataset_t *cds; /* clone dataset */
3019 dsl_dataset_t *ohds; /* origin's head dataset */
3020 boolean_t force;
3021 int64_t unused_refres_delta; /* change in unconsumed refreservation */
3022};
3023
3024/* ARGSUSED */
3025static int
3026dsl_dataset_clone_swap_check(void *arg1, void *arg2, dmu_tx_t *tx)
3027{
3028 struct cloneswaparg *csa = arg1;
3029
3030 /* they should both be heads */
3031 if (dsl_dataset_is_snapshot(csa->cds) ||
3032 dsl_dataset_is_snapshot(csa->ohds))
3033 return (EINVAL);
3034
3035 /* the branch point should be just before them */
3036 if (csa->cds->ds_prev != csa->ohds->ds_prev)
3037 return (EINVAL);
3038
3039 /* cds should be the clone (unless they are unrelated) */
3040 if (csa->cds->ds_prev != NULL &&
3041 csa->cds->ds_prev != csa->cds->ds_dir->dd_pool->dp_origin_snap &&
3042 csa->ohds->ds_object !=
3043 csa->cds->ds_prev->ds_phys->ds_next_snap_obj)
3044 return (EINVAL);
3045
3046 /* the clone should be a child of the origin */
3047 if (csa->cds->ds_dir->dd_parent != csa->ohds->ds_dir)
3048 return (EINVAL);
3049
3050 /* ohds shouldn't be modified unless 'force' */
3051 if (!csa->force && dsl_dataset_modified_since_lastsnap(csa->ohds))
3052 return (ETXTBSY);
3053
3054 /* adjust amount of any unconsumed refreservation */
3055 csa->unused_refres_delta =
3056 (int64_t)MIN(csa->ohds->ds_reserved,
3057 csa->ohds->ds_phys->ds_unique_bytes) -
3058 (int64_t)MIN(csa->ohds->ds_reserved,
3059 csa->cds->ds_phys->ds_unique_bytes);
3060
3061 if (csa->unused_refres_delta > 0 &&
3062 csa->unused_refres_delta >
3063 dsl_dir_space_available(csa->ohds->ds_dir, NULL, 0, TRUE))
3064 return (ENOSPC);
3065
3066 if (csa->ohds->ds_quota != 0 &&
3067 csa->cds->ds_phys->ds_unique_bytes > csa->ohds->ds_quota)
3068 return (EDQUOT);
3069
3070 return (0);
3071}
3072
3073/* ARGSUSED */
3074static void
3075dsl_dataset_clone_swap_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3076{
3077 struct cloneswaparg *csa = arg1;
3078 dsl_pool_t *dp = csa->cds->ds_dir->dd_pool;
3079
3080 ASSERT(csa->cds->ds_reserved == 0);
3081 ASSERT(csa->ohds->ds_quota == 0 ||
3082 csa->cds->ds_phys->ds_unique_bytes <= csa->ohds->ds_quota);
3083
3084 dmu_buf_will_dirty(csa->cds->ds_dbuf, tx);
3085 dmu_buf_will_dirty(csa->ohds->ds_dbuf, tx);
3086
3087 if (csa->cds->ds_objset != NULL) {
3088 dmu_objset_evict(csa->cds->ds_objset);
3089 csa->cds->ds_objset = NULL;
3090 }
3091
3092 if (csa->ohds->ds_objset != NULL) {
3093 dmu_objset_evict(csa->ohds->ds_objset);
3094 csa->ohds->ds_objset = NULL;
3095 }
3096
3097 /*
3098 * Reset origin's unique bytes, if it exists.
3099 */
3100 if (csa->cds->ds_prev) {
3101 dsl_dataset_t *origin = csa->cds->ds_prev;
3102 uint64_t comp, uncomp;
3103
3104 dmu_buf_will_dirty(origin->ds_dbuf, tx);
3105 dsl_deadlist_space_range(&csa->cds->ds_deadlist,
3106 origin->ds_phys->ds_prev_snap_txg, UINT64_MAX,
3107 &origin->ds_phys->ds_unique_bytes, &comp, &uncomp);
3108 }
3109
3110 /* swap blkptrs */
3111 {
3112 blkptr_t tmp;
3113 tmp = csa->ohds->ds_phys->ds_bp;
3114 csa->ohds->ds_phys->ds_bp = csa->cds->ds_phys->ds_bp;
3115 csa->cds->ds_phys->ds_bp = tmp;
3116 }
3117
3118 /* set dd_*_bytes */
3119 {
3120 int64_t dused, dcomp, duncomp;
3121 uint64_t cdl_used, cdl_comp, cdl_uncomp;
3122 uint64_t odl_used, odl_comp, odl_uncomp;
3123
3124 ASSERT3U(csa->cds->ds_dir->dd_phys->
3125 dd_used_breakdown[DD_USED_SNAP], ==, 0);
3126
3127 dsl_deadlist_space(&csa->cds->ds_deadlist,
3128 &cdl_used, &cdl_comp, &cdl_uncomp);
3129 dsl_deadlist_space(&csa->ohds->ds_deadlist,
3130 &odl_used, &odl_comp, &odl_uncomp);
3131
3132 dused = csa->cds->ds_phys->ds_used_bytes + cdl_used -
3133 (csa->ohds->ds_phys->ds_used_bytes + odl_used);
3134 dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp -
3135 (csa->ohds->ds_phys->ds_compressed_bytes + odl_comp);
3136 duncomp = csa->cds->ds_phys->ds_uncompressed_bytes +
3137 cdl_uncomp -
3138 (csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp);
3139
3140 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD,
3141 dused, dcomp, duncomp, tx);
3142 dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD,
3143 -dused, -dcomp, -duncomp, tx);
3144
3145 /*
3146 * The difference in the space used by snapshots is the
3147 * difference in snapshot space due to the head's
3148 * deadlist (since that's the only thing that's
3149 * changing that affects the snapused).
3150 */
3151 dsl_deadlist_space_range(&csa->cds->ds_deadlist,
3152 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX,
3153 &cdl_used, &cdl_comp, &cdl_uncomp);
3154 dsl_deadlist_space_range(&csa->ohds->ds_deadlist,
3155 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX,
3156 &odl_used, &odl_comp, &odl_uncomp);
3157 dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used,
3158 DD_USED_HEAD, DD_USED_SNAP, tx);
3159 }
3160
3161 /* swap ds_*_bytes */
3162 SWITCH64(csa->ohds->ds_phys->ds_used_bytes,
3163 csa->cds->ds_phys->ds_used_bytes);
3164 SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes,
3165 csa->cds->ds_phys->ds_compressed_bytes);
3166 SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes,
3167 csa->cds->ds_phys->ds_uncompressed_bytes);
3168 SWITCH64(csa->ohds->ds_phys->ds_unique_bytes,
3169 csa->cds->ds_phys->ds_unique_bytes);
3170
3171 /* apply any parent delta for change in unconsumed refreservation */
3172 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV,
3173 csa->unused_refres_delta, 0, 0, tx);
3174
3175 /*
3176 * Swap deadlists.
3177 */
3178 dsl_deadlist_close(&csa->cds->ds_deadlist);
3179 dsl_deadlist_close(&csa->ohds->ds_deadlist);
3180 SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj,
3181 csa->cds->ds_phys->ds_deadlist_obj);
3182 dsl_deadlist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset,
3183 csa->cds->ds_phys->ds_deadlist_obj);
3184 dsl_deadlist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset,
3185 csa->ohds->ds_phys->ds_deadlist_obj);
3186
3187 dsl_scan_ds_clone_swapped(csa->ohds, csa->cds, tx);
3188}
3189
3190/*
3191 * Swap 'clone' with its origin head datasets. Used at the end of "zfs
3192 * recv" into an existing fs to swizzle the file system to the new
3193 * version, and by "zfs rollback". Can also be used to swap two
3194 * independent head datasets if neither has any snapshots.
3195 */
3196int
3197dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head,
3198 boolean_t force)
3199{
3200 struct cloneswaparg csa;
3201 int error;
3202
3203 ASSERT(clone->ds_owner);
3204 ASSERT(origin_head->ds_owner);
3205retry:
3206 /*
3207 * Need exclusive access for the swap. If we're swapping these
3208 * datasets back after an error, we already hold the locks.
3209 */
3210 if (!RW_WRITE_HELD(&clone->ds_rwlock))
3211 rw_enter(&clone->ds_rwlock, RW_WRITER);
3212 if (!RW_WRITE_HELD(&origin_head->ds_rwlock) &&
3213 !rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) {
3214 rw_exit(&clone->ds_rwlock);
3215 rw_enter(&origin_head->ds_rwlock, RW_WRITER);
3216 if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) {
3217 rw_exit(&origin_head->ds_rwlock);
3218 goto retry;
3219 }
3220 }
3221 csa.cds = clone;
3222 csa.ohds = origin_head;
3223 csa.force = force;
3224 error = dsl_sync_task_do(clone->ds_dir->dd_pool,
3225 dsl_dataset_clone_swap_check,
3226 dsl_dataset_clone_swap_sync, &csa, NULL, 9);
3227 return (error);
3228}
3229
3230/*
3231 * Given a pool name and a dataset object number in that pool,
3232 * return the name of that dataset.
3233 */
3234int
3235dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf)
3236{
3237 spa_t *spa;
3238 dsl_pool_t *dp;
3239 dsl_dataset_t *ds;
3240 int error;
3241
3242 if ((error = spa_open(pname, &spa, FTAG)) != 0)
3243 return (error);
3244 dp = spa_get_dsl(spa);
3245 rw_enter(&dp->dp_config_rwlock, RW_READER);
3246 if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) {
3247 dsl_dataset_name(ds, buf);
3248 dsl_dataset_rele(ds, FTAG);
3249 }
3250 rw_exit(&dp->dp_config_rwlock);
3251 spa_close(spa, FTAG);
3252
3253 return (error);
3254}
3255
3256int
3257dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota,
3258 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv)
3259{
3260 int error = 0;
3261
3262 ASSERT3S(asize, >, 0);
3263
3264 /*
3265 * *ref_rsrv is the portion of asize that will come from any
3266 * unconsumed refreservation space.
3267 */
3268 *ref_rsrv = 0;
3269
3270 mutex_enter(&ds->ds_lock);
3271 /*
3272 * Make a space adjustment for reserved bytes.
3273 */
3274 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) {
3275 ASSERT3U(*used, >=,
3276 ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
3277 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
3278 *ref_rsrv =
3279 asize - MIN(asize, parent_delta(ds, asize + inflight));
3280 }
3281
3282 if (!check_quota || ds->ds_quota == 0) {
3283 mutex_exit(&ds->ds_lock);
3284 return (0);
3285 }
3286 /*
3287 * If they are requesting more space, and our current estimate
3288 * is over quota, they get to try again unless the actual
3289 * on-disk is over quota and there are no pending changes (which
3290 * may free up space for us).
3291 */
3292 if (ds->ds_phys->ds_used_bytes + inflight >= ds->ds_quota) {
3293 if (inflight > 0 || ds->ds_phys->ds_used_bytes < ds->ds_quota)
3294 error = ERESTART;
3295 else
3296 error = EDQUOT;
3297 }
3298 mutex_exit(&ds->ds_lock);
3299
3300 return (error);
3301}
3302
3303/* ARGSUSED */
3304static int
3305dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx)
3306{
3307 dsl_dataset_t *ds = arg1;
3308 dsl_prop_setarg_t *psa = arg2;
3309 int err;
3310
3311 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA)
3312 return (ENOTSUP);
3313
3314 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0)
3315 return (err);
3316
3317 if (psa->psa_effective_value == 0)
3318 return (0);
3319
3320 if (psa->psa_effective_value < ds->ds_phys->ds_used_bytes ||
3321 psa->psa_effective_value < ds->ds_reserved)
3322 return (ENOSPC);
3323
3324 return (0);
3325}
3326
3327extern void dsl_prop_set_sync(void *, void *, dmu_tx_t *);
3328
3329void
3330dsl_dataset_set_quota_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3331{
3332 dsl_dataset_t *ds = arg1;
3333 dsl_prop_setarg_t *psa = arg2;
3334 uint64_t effective_value = psa->psa_effective_value;
3335
3336 dsl_prop_set_sync(ds, psa, tx);
3337 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa);
3338
3339 if (ds->ds_quota != effective_value) {
3340 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3341 ds->ds_quota = effective_value;
3342
3343 spa_history_log_internal(LOG_DS_REFQUOTA,
3344 ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu ",
3345 (longlong_t)ds->ds_quota, ds->ds_object);
3346 }
3347}
3348
3349int
3350dsl_dataset_set_quota(const char *dsname, zprop_source_t source, uint64_t quota)
3351{
3352 dsl_dataset_t *ds;
3353 dsl_prop_setarg_t psa;
3354 int err;
3355
3356 dsl_prop_setarg_init_uint64(&psa, "refquota", source, "a);
3357
3358 err = dsl_dataset_hold(dsname, FTAG, &ds);
3359 if (err)
3360 return (err);
3361
3362 /*
3363 * If someone removes a file, then tries to set the quota, we
3364 * want to make sure the file freeing takes effect.
3365 */
3366 txg_wait_open(ds->ds_dir->dd_pool, 0);
3367
3368 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
3369 dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync,
3370 ds, &psa, 0);
3371
3372 dsl_dataset_rele(ds, FTAG);
3373 return (err);
3374}
3375
3376static int
3377dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx)
3378{
3379 dsl_dataset_t *ds = arg1;
3380 dsl_prop_setarg_t *psa = arg2;
3381 uint64_t effective_value;
3382 uint64_t unique;
3383 int err;
3384
3385 if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
3386 SPA_VERSION_REFRESERVATION)
3387 return (ENOTSUP);
3388
3389 if (dsl_dataset_is_snapshot(ds))
3390 return (EINVAL);
3391
3392 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0)
3393 return (err);
3394
3395 effective_value = psa->psa_effective_value;
3396
3397 /*
3398 * If we are doing the preliminary check in open context, the
3399 * space estimates may be inaccurate.
3400 */
3401 if (!dmu_tx_is_syncing(tx))
3402 return (0);
3403
3404 mutex_enter(&ds->ds_lock);
3405 if (!DS_UNIQUE_IS_ACCURATE(ds))
3406 dsl_dataset_recalc_head_uniq(ds);
3407 unique = ds->ds_phys->ds_unique_bytes;
3408 mutex_exit(&ds->ds_lock);
3409
3410 if (MAX(unique, effective_value) > MAX(unique, ds->ds_reserved)) {
3411 uint64_t delta = MAX(unique, effective_value) -
3412 MAX(unique, ds->ds_reserved);
3413
3414 if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
3415 return (ENOSPC);
3416 if (ds->ds_quota > 0 &&
3417 effective_value > ds->ds_quota)
3418 return (ENOSPC);
3419 }
3420
3421 return (0);
3422}
3423
3424static void
3425dsl_dataset_set_reservation_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3426{
3427 dsl_dataset_t *ds = arg1;
3428 dsl_prop_setarg_t *psa = arg2;
3429 uint64_t effective_value = psa->psa_effective_value;
3430 uint64_t unique;
3431 int64_t delta;
3432
3433 dsl_prop_set_sync(ds, psa, tx);
3434 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa);
3435
3436 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3437
3438 mutex_enter(&ds->ds_dir->dd_lock);
3439 mutex_enter(&ds->ds_lock);
3440 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
3441 unique = ds->ds_phys->ds_unique_bytes;
3442 delta = MAX(0, (int64_t)(effective_value - unique)) -
3443 MAX(0, (int64_t)(ds->ds_reserved - unique));
3444 ds->ds_reserved = effective_value;
3445 mutex_exit(&ds->ds_lock);
3446
3447 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx);
3448 mutex_exit(&ds->ds_dir->dd_lock);
3449
3450 spa_history_log_internal(LOG_DS_REFRESERV,
3451 ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu",
3452 (longlong_t)effective_value, ds->ds_object);
3453}
3454
3455int
3456dsl_dataset_set_reservation(const char *dsname, zprop_source_t source,
3457 uint64_t reservation)
3458{
3459 dsl_dataset_t *ds;
3460 dsl_prop_setarg_t psa;
3461 int err;
3462
3463 dsl_prop_setarg_init_uint64(&psa, "refreservation", source,
3464 &reservation);
3465
3466 err = dsl_dataset_hold(dsname, FTAG, &ds);
3467 if (err)
3468 return (err);
3469
3470 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
3471 dsl_dataset_set_reservation_check,
3472 dsl_dataset_set_reservation_sync, ds, &psa, 0);
3473
3474 dsl_dataset_rele(ds, FTAG);
3475 return (err);
3476}
3477
3478typedef struct zfs_hold_cleanup_arg {
3479 dsl_pool_t *dp;
3480 uint64_t dsobj;
3481 char htag[MAXNAMELEN];
3482} zfs_hold_cleanup_arg_t;
3483
3484static void
3485dsl_dataset_user_release_onexit(void *arg)
3486{
3487 zfs_hold_cleanup_arg_t *ca = arg;
3488
3489 (void) dsl_dataset_user_release_tmp(ca->dp, ca->dsobj, ca->htag,
3490 B_TRUE);
3491 kmem_free(ca, sizeof (zfs_hold_cleanup_arg_t));
3492}
3493
3494void
3495dsl_register_onexit_hold_cleanup(dsl_dataset_t *ds, const char *htag,
3496 minor_t minor)
3497{
3498 zfs_hold_cleanup_arg_t *ca;
3499
3500 ca = kmem_alloc(sizeof (zfs_hold_cleanup_arg_t), KM_SLEEP);
3501 ca->dp = ds->ds_dir->dd_pool;
3502 ca->dsobj = ds->ds_object;
3503 (void) strlcpy(ca->htag, htag, sizeof (ca->htag));
3504 VERIFY3U(0, ==, zfs_onexit_add_cb(minor,
3505 dsl_dataset_user_release_onexit, ca, NULL));
3506}
3507
3508/*
3509 * If you add new checks here, you may need to add
3510 * additional checks to the "temporary" case in
3511 * snapshot_check() in dmu_objset.c.
3512 */
3513static int
3514dsl_dataset_user_hold_check(void *arg1, void *arg2, dmu_tx_t *tx)
3515{
3516 dsl_dataset_t *ds = arg1;
3517 struct dsl_ds_holdarg *ha = arg2;
3518 char *htag = ha->htag;
3519 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3520 int error = 0;
3521
3522 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS)
3523 return (ENOTSUP);
3524
3525 if (!dsl_dataset_is_snapshot(ds))
3526 return (EINVAL);
3527
3528 /* tags must be unique */
3529 mutex_enter(&ds->ds_lock);
3530 if (ds->ds_phys->ds_userrefs_obj) {
3531 error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj, htag,
3532 8, 1, tx);
3533 if (error == 0)
3534 error = EEXIST;
3535 else if (error == ENOENT)
3536 error = 0;
3537 }
3538 mutex_exit(&ds->ds_lock);
3539
3540 if (error == 0 && ha->temphold &&
3541 strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN)
3542 error = E2BIG;
3543
3544 return (error);
3545}
3546
3547void
3548dsl_dataset_user_hold_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3549{
3550 dsl_dataset_t *ds = arg1;
3551 struct dsl_ds_holdarg *ha = arg2;
3552 char *htag = ha->htag;
3553 dsl_pool_t *dp = ds->ds_dir->dd_pool;
3554 objset_t *mos = dp->dp_meta_objset;
3555 uint64_t now = gethrestime_sec();
3556 uint64_t zapobj;
3557
3558 mutex_enter(&ds->ds_lock);
3559 if (ds->ds_phys->ds_userrefs_obj == 0) {
3560 /*
3561 * This is the first user hold for this dataset. Create
3562 * the userrefs zap object.
3563 */
3564 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3565 zapobj = ds->ds_phys->ds_userrefs_obj =
3566 zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx);
3567 } else {
3568 zapobj = ds->ds_phys->ds_userrefs_obj;
3569 }
3570 ds->ds_userrefs++;
3571 mutex_exit(&ds->ds_lock);
3572
3573 VERIFY(0 == zap_add(mos, zapobj, htag, 8, 1, &now, tx));
3574
3575 if (ha->temphold) {
3576 VERIFY(0 == dsl_pool_user_hold(dp, ds->ds_object,
3577 htag, &now, tx));
3578 }
3579
3580 spa_history_log_internal(LOG_DS_USER_HOLD,
3581 dp->dp_spa, tx, "<%s> temp = %d dataset = %llu", htag,
3582 (int)ha->temphold, ds->ds_object);
3583}
3584
3585static int
3586dsl_dataset_user_hold_one(const char *dsname, void *arg)
3587{
3588 struct dsl_ds_holdarg *ha = arg;
3589 dsl_dataset_t *ds;
3590 int error;
3591 char *name;
3592
3593 /* alloc a buffer to hold dsname@snapname plus terminating NULL */
3594 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3595 error = dsl_dataset_hold(name, ha->dstg, &ds);
3596 strfree(name);
3597 if (error == 0) {
3598 ha->gotone = B_TRUE;
3599 dsl_sync_task_create(ha->dstg, dsl_dataset_user_hold_check,
3600 dsl_dataset_user_hold_sync, ds, ha, 0);
3601 } else if (error == ENOENT && ha->recursive) {
3602 error = 0;
3603 } else {
3604 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3605 }
3606 return (error);
3607}
3608
3609int
3610dsl_dataset_user_hold_for_send(dsl_dataset_t *ds, char *htag,
3611 boolean_t temphold)
3612{
3613 struct dsl_ds_holdarg *ha;
3614 int error;
3615
3616 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3617 ha->htag = htag;
3618 ha->temphold = temphold;
3619 error = dsl_sync_task_do(ds->ds_dir->dd_pool,
3620 dsl_dataset_user_hold_check, dsl_dataset_user_hold_sync,
3621 ds, ha, 0);
3622 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3623
3624 return (error);
3625}
3626
3627int
3628dsl_dataset_user_hold(char *dsname, char *snapname, char *htag,
3629 boolean_t recursive, boolean_t temphold, int cleanup_fd)
3630{
3631 struct dsl_ds_holdarg *ha;
3632 dsl_sync_task_t *dst;
3633 spa_t *spa;
3634 int error;
3635 minor_t minor = 0;
3636
3637 if (cleanup_fd != -1) {
3638 /* Currently we only support cleanup-on-exit of tempholds. */
3639 if (!temphold)
3640 return (EINVAL);
3641 error = zfs_onexit_fd_hold(cleanup_fd, &minor);
3642 if (error)
3643 return (error);
3644 }
3645
3646 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3647
3648 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3649
3650 error = spa_open(dsname, &spa, FTAG);
3651 if (error) {
3652 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3653 if (cleanup_fd != -1)
3654 zfs_onexit_fd_rele(cleanup_fd);
3655 return (error);
3656 }
3657
3658 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
3659 ha->htag = htag;
3660 ha->snapname = snapname;
3661 ha->recursive = recursive;
3662 ha->temphold = temphold;
3663
3664 if (recursive) {
3665 error = dmu_objset_find(dsname, dsl_dataset_user_hold_one,
3666 ha, DS_FIND_CHILDREN);
3667 } else {
3668 error = dsl_dataset_user_hold_one(dsname, ha);
3669 }
3670 if (error == 0)
3671 error = dsl_sync_task_group_wait(ha->dstg);
3672
3673 for (dst = list_head(&ha->dstg->dstg_tasks); dst;
3674 dst = list_next(&ha->dstg->dstg_tasks, dst)) {
3675 dsl_dataset_t *ds = dst->dst_arg1;
3676
3677 if (dst->dst_err) {
3678 dsl_dataset_name(ds, ha->failed);
3679 *strchr(ha->failed, '@') = '\0';
3680 } else if (error == 0 && minor != 0 && temphold) {
3681 /*
3682 * If this hold is to be released upon process exit,
3683 * register that action now.
3684 */
3685 dsl_register_onexit_hold_cleanup(ds, htag, minor);
3686 }
3687 dsl_dataset_rele(ds, ha->dstg);
3688 }
3689
3690 if (error == 0 && recursive && !ha->gotone)
3691 error = ENOENT;
3692
3693 if (error)
3694 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed));
3695
3696 dsl_sync_task_group_destroy(ha->dstg);
3697
3698 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3699 spa_close(spa, FTAG);
3700 if (cleanup_fd != -1)
3701 zfs_onexit_fd_rele(cleanup_fd);
3702 return (error);
3703}
3704
3705struct dsl_ds_releasearg {
3706 dsl_dataset_t *ds;
3707 const char *htag;
3708 boolean_t own; /* do we own or just hold ds? */
3709};
3710
3711static int
3712dsl_dataset_release_might_destroy(dsl_dataset_t *ds, const char *htag,
3713 boolean_t *might_destroy)
3714{
3715 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3716 uint64_t zapobj;
3717 uint64_t tmp;
3718 int error;
3719
3720 *might_destroy = B_FALSE;
3721
3722 mutex_enter(&ds->ds_lock);
3723 zapobj = ds->ds_phys->ds_userrefs_obj;
3724 if (zapobj == 0) {
3725 /* The tag can't possibly exist */
3726 mutex_exit(&ds->ds_lock);
3727 return (ESRCH);
3728 }
3729
3730 /* Make sure the tag exists */
3731 error = zap_lookup(mos, zapobj, htag, 8, 1, &tmp);
3732 if (error) {
3733 mutex_exit(&ds->ds_lock);
3734 if (error == ENOENT)
3735 error = ESRCH;
3736 return (error);
3737 }
3738
3739 if (ds->ds_userrefs == 1 && ds->ds_phys->ds_num_children == 1 &&
3740 DS_IS_DEFER_DESTROY(ds))
3741 *might_destroy = B_TRUE;
3742
3743 mutex_exit(&ds->ds_lock);
3744 return (0);
3745}
3746
3747static int
3748dsl_dataset_user_release_check(void *arg1, void *tag, dmu_tx_t *tx)
3749{
3750 struct dsl_ds_releasearg *ra = arg1;
3751 dsl_dataset_t *ds = ra->ds;
3752 boolean_t might_destroy;
3753 int error;
3754
3755 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS)
3756 return (ENOTSUP);
3757
3758 error = dsl_dataset_release_might_destroy(ds, ra->htag, &might_destroy);
3759 if (error)
3760 return (error);
3761
3762 if (might_destroy) {
3763 struct dsl_ds_destroyarg dsda = {0};
3764
3765 if (dmu_tx_is_syncing(tx)) {
3766 /*
3767 * If we're not prepared to remove the snapshot,
3768 * we can't allow the release to happen right now.
3769 */
3770 if (!ra->own)
3771 return (EBUSY);
3772 }
3773 dsda.ds = ds;
3774 dsda.releasing = B_TRUE;
3775 return (dsl_dataset_destroy_check(&dsda, tag, tx));
3776 }
3777
3778 return (0);
3779}
3780
3781static void
3782dsl_dataset_user_release_sync(void *arg1, void *tag, dmu_tx_t *tx)
3783{
3784 struct dsl_ds_releasearg *ra = arg1;
3785 dsl_dataset_t *ds = ra->ds;
3786 dsl_pool_t *dp = ds->ds_dir->dd_pool;
3787 objset_t *mos = dp->dp_meta_objset;
3788 uint64_t zapobj;
3789 uint64_t dsobj = ds->ds_object;
3790 uint64_t refs;
3791 int error;
3792
3793 mutex_enter(&ds->ds_lock);
3794 ds->ds_userrefs--;
3795 refs = ds->ds_userrefs;
3796 mutex_exit(&ds->ds_lock);
3797 error = dsl_pool_user_release(dp, ds->ds_object, ra->htag, tx);
3798 VERIFY(error == 0 || error == ENOENT);
3799 zapobj = ds->ds_phys->ds_userrefs_obj;
3800 VERIFY(0 == zap_remove(mos, zapobj, ra->htag, tx));
3801 if (ds->ds_userrefs == 0 && ds->ds_phys->ds_num_children == 1 &&
3802 DS_IS_DEFER_DESTROY(ds)) {
3803 struct dsl_ds_destroyarg dsda = {0};
3804
3805 ASSERT(ra->own);
3806 dsda.ds = ds;
3807 dsda.releasing = B_TRUE;
3808 /* We already did the destroy_check */
3809 dsl_dataset_destroy_sync(&dsda, tag, tx);
3810 }
3811
3812 spa_history_log_internal(LOG_DS_USER_RELEASE,
3813 dp->dp_spa, tx, "<%s> %lld dataset = %llu",
3814 ra->htag, (longlong_t)refs, dsobj);
3815}
3816
3817static int
3818dsl_dataset_user_release_one(const char *dsname, void *arg)
3819{
3820 struct dsl_ds_holdarg *ha = arg;
3821 struct dsl_ds_releasearg *ra;
3822 dsl_dataset_t *ds;
3823 int error;
3824 void *dtag = ha->dstg;
3825 char *name;
3826 boolean_t own = B_FALSE;
3827 boolean_t might_destroy;
3828
3829 /* alloc a buffer to hold dsname@snapname, plus the terminating NULL */
3830 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3831 error = dsl_dataset_hold(name, dtag, &ds);
3832 strfree(name);
3833 if (error == ENOENT && ha->recursive)
3834 return (0);
3835 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3836 if (error)
3837 return (error);
3838
3839 ha->gotone = B_TRUE;
3840
3841 ASSERT(dsl_dataset_is_snapshot(ds));
3842
3843 error = dsl_dataset_release_might_destroy(ds, ha->htag, &might_destroy);
3844 if (error) {
3845 dsl_dataset_rele(ds, dtag);
3846 return (error);
3847 }
3848
3849 if (might_destroy) {
3850#ifdef _KERNEL
3851 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3852 error = zfs_unmount_snap(name, NULL);
3853 strfree(name);
3854 if (error) {
3855 dsl_dataset_rele(ds, dtag);
3856 return (error);
3857 }
3858#endif
3859 if (!dsl_dataset_tryown(ds, B_TRUE, dtag)) {
3860 dsl_dataset_rele(ds, dtag);
3861 return (EBUSY);
3862 } else {
3863 own = B_TRUE;
3864 dsl_dataset_make_exclusive(ds, dtag);
3865 }
3866 }
3867
3868 ra = kmem_alloc(sizeof (struct dsl_ds_releasearg), KM_SLEEP);
3869 ra->ds = ds;
3870 ra->htag = ha->htag;
3871 ra->own = own;
3872 dsl_sync_task_create(ha->dstg, dsl_dataset_user_release_check,
3873 dsl_dataset_user_release_sync, ra, dtag, 0);
3874
3875 return (0);
3876}
3877
3878int
3879dsl_dataset_user_release(char *dsname, char *snapname, char *htag,
3880 boolean_t recursive)
3881{
3882 struct dsl_ds_holdarg *ha;
3883 dsl_sync_task_t *dst;
3884 spa_t *spa;
3885 int error;
3886
3887top:
3888 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3889
3890 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3891
3892 error = spa_open(dsname, &spa, FTAG);
3893 if (error) {
3894 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3895 return (error);
3896 }
3897
3898 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
3899 ha->htag = htag;
3900 ha->snapname = snapname;
3901 ha->recursive = recursive;
3902 if (recursive) {
3903 error = dmu_objset_find(dsname, dsl_dataset_user_release_one,
3904 ha, DS_FIND_CHILDREN);
3905 } else {
3906 error = dsl_dataset_user_release_one(dsname, ha);
3907 }
3908 if (error == 0)
3909 error = dsl_sync_task_group_wait(ha->dstg);
3910
3911 for (dst = list_head(&ha->dstg->dstg_tasks); dst;
3912 dst = list_next(&ha->dstg->dstg_tasks, dst)) {
3913 struct dsl_ds_releasearg *ra = dst->dst_arg1;
3914 dsl_dataset_t *ds = ra->ds;
3915
3916 if (dst->dst_err)
3917 dsl_dataset_name(ds, ha->failed);
3918
3919 if (ra->own)
3920 dsl_dataset_disown(ds, ha->dstg);
3921 else
3922 dsl_dataset_rele(ds, ha->dstg);
3923
3924 kmem_free(ra, sizeof (struct dsl_ds_releasearg));
3925 }
3926
3927 if (error == 0 && recursive && !ha->gotone)
3928 error = ENOENT;
3929
3930 if (error && error != EBUSY)
3931 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed));
3932
3933 dsl_sync_task_group_destroy(ha->dstg);
3934 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3935 spa_close(spa, FTAG);
3936
3937 /*
3938 * We can get EBUSY if we were racing with deferred destroy and
3939 * dsl_dataset_user_release_check() hadn't done the necessary
3940 * open context setup. We can also get EBUSY if we're racing
3941 * with destroy and that thread is the ds_owner. Either way
3942 * the busy condition should be transient, and we should retry
3943 * the release operation.
3944 */
3945 if (error == EBUSY)
3946 goto top;
3947
3948 return (error);
3949}
3950
3951/*
3952 * Called at spa_load time (with retry == B_FALSE) to release a stale
3953 * temporary user hold. Also called by the onexit code (with retry == B_TRUE).
3954 */
3955int
3956dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, char *htag,
3957 boolean_t retry)
3958{
3959 dsl_dataset_t *ds;
3960 char *snap;
3961 char *name;
3962 int namelen;
3963 int error;
3964
3965 do {
3966 rw_enter(&dp->dp_config_rwlock, RW_READER);
3967 error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds);
3968 rw_exit(&dp->dp_config_rwlock);
3969 if (error)
3970 return (error);
3971 namelen = dsl_dataset_namelen(ds)+1;
3972 name = kmem_alloc(namelen, KM_SLEEP);
3973 dsl_dataset_name(ds, name);
3974 dsl_dataset_rele(ds, FTAG);
3975
3976 snap = strchr(name, '@');
3977 *snap = '\0';
3978 ++snap;
3979 error = dsl_dataset_user_release(name, snap, htag, B_FALSE);
3980 kmem_free(name, namelen);
3981
3982 /*
3983 * The object can't have been destroyed because we have a hold,
3984 * but it might have been renamed, resulting in ENOENT. Retry
3985 * if we've been requested to do so.
3986 *
3987 * It would be nice if we could use the dsobj all the way
3988 * through and avoid ENOENT entirely. But we might need to
3989 * unmount the snapshot, and there's currently no way to lookup
3990 * a vfsp using a ZFS object id.
3991 */
3992 } while ((error == ENOENT) && retry);
3993
3994 return (error);
3995}
3996
3997int
3998dsl_dataset_get_holds(const char *dsname, nvlist_t **nvp)
3999{
4000 dsl_dataset_t *ds;
4001 int err;
4002
4003 err = dsl_dataset_hold(dsname, FTAG, &ds);
4004 if (err)
4005 return (err);
4006
4007 VERIFY(0 == nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP));
4008 if (ds->ds_phys->ds_userrefs_obj != 0) {
4009 zap_attribute_t *za;
4010 zap_cursor_t zc;
4011
4012 za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP);
4013 for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset,
4014 ds->ds_phys->ds_userrefs_obj);
4015 zap_cursor_retrieve(&zc, za) == 0;
4016 zap_cursor_advance(&zc)) {
4017 VERIFY(0 == nvlist_add_uint64(*nvp, za->za_name,
4018 za->za_first_integer));
4019 }
4020 zap_cursor_fini(&zc);
4021 kmem_free(za, sizeof (zap_attribute_t));
4022 }
4023 dsl_dataset_rele(ds, FTAG);
4024 return (0);
4025}
4026
4027/*
| 2294 }
2295}
2296
2297void
2298dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat)
2299{
2300 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg;
2301 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT;
2302 stat->dds_guid = ds->ds_phys->ds_guid;
2303 if (ds->ds_phys->ds_next_snap_obj) {
2304 stat->dds_is_snapshot = B_TRUE;
2305 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1;
2306 } else {
2307 stat->dds_is_snapshot = B_FALSE;
2308 stat->dds_num_clones = 0;
2309 }
2310
2311 /* clone origin is really a dsl_dir thing... */
2312 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER);
2313 if (dsl_dir_is_clone(ds->ds_dir)) {
2314 dsl_dataset_t *ods;
2315
2316 VERIFY(0 == dsl_dataset_get_ref(ds->ds_dir->dd_pool,
2317 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods));
2318 dsl_dataset_name(ods, stat->dds_origin);
2319 dsl_dataset_drop_ref(ods, FTAG);
2320 } else {
2321 stat->dds_origin[0] = '\0';
2322 }
2323 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock);
2324}
2325
2326uint64_t
2327dsl_dataset_fsid_guid(dsl_dataset_t *ds)
2328{
2329 return (ds->ds_fsid_guid);
2330}
2331
2332void
2333dsl_dataset_space(dsl_dataset_t *ds,
2334 uint64_t *refdbytesp, uint64_t *availbytesp,
2335 uint64_t *usedobjsp, uint64_t *availobjsp)
2336{
2337 *refdbytesp = ds->ds_phys->ds_used_bytes;
2338 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE);
2339 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes)
2340 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes;
2341 if (ds->ds_quota != 0) {
2342 /*
2343 * Adjust available bytes according to refquota
2344 */
2345 if (*refdbytesp < ds->ds_quota)
2346 *availbytesp = MIN(*availbytesp,
2347 ds->ds_quota - *refdbytesp);
2348 else
2349 *availbytesp = 0;
2350 }
2351 *usedobjsp = ds->ds_phys->ds_bp.blk_fill;
2352 *availobjsp = DN_MAX_OBJECT - *usedobjsp;
2353}
2354
2355boolean_t
2356dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds)
2357{
2358 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2359
2360 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) ||
2361 dsl_pool_sync_context(dp));
2362 if (ds->ds_prev == NULL)
2363 return (B_FALSE);
2364 if (ds->ds_phys->ds_bp.blk_birth >
2365 ds->ds_prev->ds_phys->ds_creation_txg) {
2366 objset_t *os, *os_prev;
2367 /*
2368 * It may be that only the ZIL differs, because it was
2369 * reset in the head. Don't count that as being
2370 * modified.
2371 */
2372 if (dmu_objset_from_ds(ds, &os) != 0)
2373 return (B_TRUE);
2374 if (dmu_objset_from_ds(ds->ds_prev, &os_prev) != 0)
2375 return (B_TRUE);
2376 return (bcmp(&os->os_phys->os_meta_dnode,
2377 &os_prev->os_phys->os_meta_dnode,
2378 sizeof (os->os_phys->os_meta_dnode)) != 0);
2379 }
2380 return (B_FALSE);
2381}
2382
2383/* ARGSUSED */
2384static int
2385dsl_dataset_snapshot_rename_check(void *arg1, void *arg2, dmu_tx_t *tx)
2386{
2387 dsl_dataset_t *ds = arg1;
2388 char *newsnapname = arg2;
2389 dsl_dir_t *dd = ds->ds_dir;
2390 dsl_dataset_t *hds;
2391 uint64_t val;
2392 int err;
2393
2394 err = dsl_dataset_hold_obj(dd->dd_pool,
2395 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds);
2396 if (err)
2397 return (err);
2398
2399 /* new name better not be in use */
2400 err = dsl_dataset_snap_lookup(hds, newsnapname, &val);
2401 dsl_dataset_rele(hds, FTAG);
2402
2403 if (err == 0)
2404 err = EEXIST;
2405 else if (err == ENOENT)
2406 err = 0;
2407
2408 /* dataset name + 1 for the "@" + the new snapshot name must fit */
2409 if (dsl_dir_namelen(ds->ds_dir) + 1 + strlen(newsnapname) >= MAXNAMELEN)
2410 err = ENAMETOOLONG;
2411
2412 return (err);
2413}
2414
2415static void
2416dsl_dataset_snapshot_rename_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2417{
2418 char oldname[MAXPATHLEN], newname[MAXPATHLEN];
2419 dsl_dataset_t *ds = arg1;
2420 const char *newsnapname = arg2;
2421 dsl_dir_t *dd = ds->ds_dir;
2422 objset_t *mos = dd->dd_pool->dp_meta_objset;
2423 dsl_dataset_t *hds;
2424 int err;
2425
2426 ASSERT(ds->ds_phys->ds_next_snap_obj != 0);
2427
2428 VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool,
2429 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds));
2430
2431 VERIFY(0 == dsl_dataset_get_snapname(ds));
2432 err = dsl_dataset_snap_remove(hds, ds->ds_snapname, tx);
2433 ASSERT3U(err, ==, 0);
2434 dsl_dataset_name(ds, oldname);
2435 mutex_enter(&ds->ds_lock);
2436 (void) strcpy(ds->ds_snapname, newsnapname);
2437 mutex_exit(&ds->ds_lock);
2438 err = zap_add(mos, hds->ds_phys->ds_snapnames_zapobj,
2439 ds->ds_snapname, 8, 1, &ds->ds_object, tx);
2440 ASSERT3U(err, ==, 0);
2441 dsl_dataset_name(ds, newname);
2442#ifdef _KERNEL
2443 zvol_rename_minors(oldname, newname);
2444#endif
2445
2446 spa_history_log_internal(LOG_DS_RENAME, dd->dd_pool->dp_spa, tx,
2447 "dataset = %llu", ds->ds_object);
2448 dsl_dataset_rele(hds, FTAG);
2449}
2450
2451struct renamesnaparg {
2452 dsl_sync_task_group_t *dstg;
2453 char failed[MAXPATHLEN];
2454 char *oldsnap;
2455 char *newsnap;
2456};
2457
2458static int
2459dsl_snapshot_rename_one(const char *name, void *arg)
2460{
2461 struct renamesnaparg *ra = arg;
2462 dsl_dataset_t *ds = NULL;
2463 char *snapname;
2464 int err;
2465
2466 snapname = kmem_asprintf("%s@%s", name, ra->oldsnap);
2467 (void) strlcpy(ra->failed, snapname, sizeof (ra->failed));
2468
2469 /*
2470 * For recursive snapshot renames the parent won't be changing
2471 * so we just pass name for both the to/from argument.
2472 */
2473 err = zfs_secpolicy_rename_perms(snapname, snapname, CRED());
2474 if (err != 0) {
2475 strfree(snapname);
2476 return (err == ENOENT ? 0 : err);
2477 }
2478
2479#ifdef _KERNEL
2480 /*
2481 * For all filesystems undergoing rename, we'll need to unmount it.
2482 */
2483 (void) zfs_unmount_snap(snapname, NULL);
2484#endif
2485 err = dsl_dataset_hold(snapname, ra->dstg, &ds);
2486 strfree(snapname);
2487 if (err != 0)
2488 return (err == ENOENT ? 0 : err);
2489
2490 dsl_sync_task_create(ra->dstg, dsl_dataset_snapshot_rename_check,
2491 dsl_dataset_snapshot_rename_sync, ds, ra->newsnap, 0);
2492
2493 return (0);
2494}
2495
2496static int
2497dsl_recursive_rename(char *oldname, const char *newname)
2498{
2499 int err;
2500 struct renamesnaparg *ra;
2501 dsl_sync_task_t *dst;
2502 spa_t *spa;
2503 char *cp, *fsname = spa_strdup(oldname);
2504 int len = strlen(oldname) + 1;
2505
2506 /* truncate the snapshot name to get the fsname */
2507 cp = strchr(fsname, '@');
2508 *cp = '\0';
2509
2510 err = spa_open(fsname, &spa, FTAG);
2511 if (err) {
2512 kmem_free(fsname, len);
2513 return (err);
2514 }
2515 ra = kmem_alloc(sizeof (struct renamesnaparg), KM_SLEEP);
2516 ra->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
2517
2518 ra->oldsnap = strchr(oldname, '@') + 1;
2519 ra->newsnap = strchr(newname, '@') + 1;
2520 *ra->failed = '\0';
2521
2522 err = dmu_objset_find(fsname, dsl_snapshot_rename_one, ra,
2523 DS_FIND_CHILDREN);
2524 kmem_free(fsname, len);
2525
2526 if (err == 0) {
2527 err = dsl_sync_task_group_wait(ra->dstg);
2528 }
2529
2530 for (dst = list_head(&ra->dstg->dstg_tasks); dst;
2531 dst = list_next(&ra->dstg->dstg_tasks, dst)) {
2532 dsl_dataset_t *ds = dst->dst_arg1;
2533 if (dst->dst_err) {
2534 dsl_dir_name(ds->ds_dir, ra->failed);
2535 (void) strlcat(ra->failed, "@", sizeof (ra->failed));
2536 (void) strlcat(ra->failed, ra->newsnap,
2537 sizeof (ra->failed));
2538 }
2539 dsl_dataset_rele(ds, ra->dstg);
2540 }
2541
2542 if (err)
2543 (void) strlcpy(oldname, ra->failed, sizeof (ra->failed));
2544
2545 dsl_sync_task_group_destroy(ra->dstg);
2546 kmem_free(ra, sizeof (struct renamesnaparg));
2547 spa_close(spa, FTAG);
2548 return (err);
2549}
2550
2551static int
2552dsl_valid_rename(const char *oldname, void *arg)
2553{
2554 int delta = *(int *)arg;
2555
2556 if (strlen(oldname) + delta >= MAXNAMELEN)
2557 return (ENAMETOOLONG);
2558
2559 return (0);
2560}
2561
2562#pragma weak dmu_objset_rename = dsl_dataset_rename
2563int
2564dsl_dataset_rename(char *oldname, const char *newname, int flags)
2565{
2566 dsl_dir_t *dd;
2567 dsl_dataset_t *ds;
2568 const char *tail;
2569 int err;
2570
2571 err = dsl_dir_open(oldname, FTAG, &dd, &tail);
2572 if (err)
2573 return (err);
2574
2575 if (tail == NULL) {
2576 int delta = strlen(newname) - strlen(oldname);
2577
2578 /* if we're growing, validate child name lengths */
2579 if (delta > 0)
2580 err = dmu_objset_find(oldname, dsl_valid_rename,
2581 &delta, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS);
2582
2583 if (err == 0)
2584 err = dsl_dir_rename(dd, newname, flags);
2585 dsl_dir_close(dd, FTAG);
2586 return (err);
2587 }
2588
2589 if (tail[0] != '@') {
2590 /* the name ended in a nonexistent component */
2591 dsl_dir_close(dd, FTAG);
2592 return (ENOENT);
2593 }
2594
2595 dsl_dir_close(dd, FTAG);
2596
2597 /* new name must be snapshot in same filesystem */
2598 tail = strchr(newname, '@');
2599 if (tail == NULL)
2600 return (EINVAL);
2601 tail++;
2602 if (strncmp(oldname, newname, tail - newname) != 0)
2603 return (EXDEV);
2604
2605 if (flags & ZFS_RENAME_RECURSIVE) {
2606 err = dsl_recursive_rename(oldname, newname);
2607 } else {
2608 err = dsl_dataset_hold(oldname, FTAG, &ds);
2609 if (err)
2610 return (err);
2611
2612 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
2613 dsl_dataset_snapshot_rename_check,
2614 dsl_dataset_snapshot_rename_sync, ds, (char *)tail, 1);
2615
2616 dsl_dataset_rele(ds, FTAG);
2617 }
2618
2619 return (err);
2620}
2621
2622struct promotenode {
2623 list_node_t link;
2624 dsl_dataset_t *ds;
2625};
2626
2627struct promotearg {
2628 list_t shared_snaps, origin_snaps, clone_snaps;
2629 dsl_dataset_t *origin_origin;
2630 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap;
2631 char *err_ds;
2632};
2633
2634static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep);
2635static boolean_t snaplist_unstable(list_t *l);
2636
2637static int
2638dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx)
2639{
2640 dsl_dataset_t *hds = arg1;
2641 struct promotearg *pa = arg2;
2642 struct promotenode *snap = list_head(&pa->shared_snaps);
2643 dsl_dataset_t *origin_ds = snap->ds;
2644 int err;
2645 uint64_t unused;
2646
2647 /* Check that it is a real clone */
2648 if (!dsl_dir_is_clone(hds->ds_dir))
2649 return (EINVAL);
2650
2651 /* Since this is so expensive, don't do the preliminary check */
2652 if (!dmu_tx_is_syncing(tx))
2653 return (0);
2654
2655 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE)
2656 return (EXDEV);
2657
2658 /* compute origin's new unique space */
2659 snap = list_tail(&pa->clone_snaps);
2660 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2661 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2662 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX,
2663 &pa->unique, &unused, &unused);
2664
2665 /*
2666 * Walk the snapshots that we are moving
2667 *
2668 * Compute space to transfer. Consider the incremental changes
2669 * to used for each snapshot:
2670 * (my used) = (prev's used) + (blocks born) - (blocks killed)
2671 * So each snapshot gave birth to:
2672 * (blocks born) = (my used) - (prev's used) + (blocks killed)
2673 * So a sequence would look like:
2674 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0)
2675 * Which simplifies to:
2676 * uN + kN + kN-1 + ... + k1 + k0
2677 * Note however, if we stop before we reach the ORIGIN we get:
2678 * uN + kN + kN-1 + ... + kM - uM-1
2679 */
2680 pa->used = origin_ds->ds_phys->ds_used_bytes;
2681 pa->comp = origin_ds->ds_phys->ds_compressed_bytes;
2682 pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes;
2683 for (snap = list_head(&pa->shared_snaps); snap;
2684 snap = list_next(&pa->shared_snaps, snap)) {
2685 uint64_t val, dlused, dlcomp, dluncomp;
2686 dsl_dataset_t *ds = snap->ds;
2687
2688 /* Check that the snapshot name does not conflict */
2689 VERIFY(0 == dsl_dataset_get_snapname(ds));
2690 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val);
2691 if (err == 0) {
2692 err = EEXIST;
2693 goto out;
2694 }
2695 if (err != ENOENT)
2696 goto out;
2697
2698 /* The very first snapshot does not have a deadlist */
2699 if (ds->ds_phys->ds_prev_snap_obj == 0)
2700 continue;
2701
2702 dsl_deadlist_space(&ds->ds_deadlist,
2703 &dlused, &dlcomp, &dluncomp);
2704 pa->used += dlused;
2705 pa->comp += dlcomp;
2706 pa->uncomp += dluncomp;
2707 }
2708
2709 /*
2710 * If we are a clone of a clone then we never reached ORIGIN,
2711 * so we need to subtract out the clone origin's used space.
2712 */
2713 if (pa->origin_origin) {
2714 pa->used -= pa->origin_origin->ds_phys->ds_used_bytes;
2715 pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes;
2716 pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes;
2717 }
2718
2719 /* Check that there is enough space here */
2720 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir,
2721 pa->used);
2722 if (err)
2723 return (err);
2724
2725 /*
2726 * Compute the amounts of space that will be used by snapshots
2727 * after the promotion (for both origin and clone). For each,
2728 * it is the amount of space that will be on all of their
2729 * deadlists (that was not born before their new origin).
2730 */
2731 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2732 uint64_t space;
2733
2734 /*
2735 * Note, typically this will not be a clone of a clone,
2736 * so dd_origin_txg will be < TXG_INITIAL, so
2737 * these snaplist_space() -> dsl_deadlist_space_range()
2738 * calls will be fast because they do not have to
2739 * iterate over all bps.
2740 */
2741 snap = list_head(&pa->origin_snaps);
2742 err = snaplist_space(&pa->shared_snaps,
2743 snap->ds->ds_dir->dd_origin_txg, &pa->cloneusedsnap);
2744 if (err)
2745 return (err);
2746
2747 err = snaplist_space(&pa->clone_snaps,
2748 snap->ds->ds_dir->dd_origin_txg, &space);
2749 if (err)
2750 return (err);
2751 pa->cloneusedsnap += space;
2752 }
2753 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2754 err = snaplist_space(&pa->origin_snaps,
2755 origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap);
2756 if (err)
2757 return (err);
2758 }
2759
2760 return (0);
2761out:
2762 pa->err_ds = snap->ds->ds_snapname;
2763 return (err);
2764}
2765
2766static void
2767dsl_dataset_promote_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2768{
2769 dsl_dataset_t *hds = arg1;
2770 struct promotearg *pa = arg2;
2771 struct promotenode *snap = list_head(&pa->shared_snaps);
2772 dsl_dataset_t *origin_ds = snap->ds;
2773 dsl_dataset_t *origin_head;
2774 dsl_dir_t *dd = hds->ds_dir;
2775 dsl_pool_t *dp = hds->ds_dir->dd_pool;
2776 dsl_dir_t *odd = NULL;
2777 uint64_t oldnext_obj;
2778 int64_t delta;
2779
2780 ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE));
2781
2782 snap = list_head(&pa->origin_snaps);
2783 origin_head = snap->ds;
2784
2785 /*
2786 * We need to explicitly open odd, since origin_ds's dd will be
2787 * changing.
2788 */
2789 VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object,
2790 NULL, FTAG, &odd));
2791
2792 /* change origin's next snap */
2793 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx);
2794 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj;
2795 snap = list_tail(&pa->clone_snaps);
2796 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2797 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object;
2798
2799 /* change the origin's next clone */
2800 if (origin_ds->ds_phys->ds_next_clones_obj) {
2801 remove_from_next_clones(origin_ds, snap->ds->ds_object, tx);
2802 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2803 origin_ds->ds_phys->ds_next_clones_obj,
2804 oldnext_obj, tx));
2805 }
2806
2807 /* change origin */
2808 dmu_buf_will_dirty(dd->dd_dbuf, tx);
2809 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object);
2810 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj;
2811 dd->dd_origin_txg = origin_head->ds_dir->dd_origin_txg;
2812 dmu_buf_will_dirty(odd->dd_dbuf, tx);
2813 odd->dd_phys->dd_origin_obj = origin_ds->ds_object;
2814 origin_head->ds_dir->dd_origin_txg =
2815 origin_ds->ds_phys->ds_creation_txg;
2816
2817 /* change dd_clone entries */
2818 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2819 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
2820 odd->dd_phys->dd_clones, hds->ds_object, tx));
2821 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2822 pa->origin_origin->ds_dir->dd_phys->dd_clones,
2823 hds->ds_object, tx));
2824
2825 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
2826 pa->origin_origin->ds_dir->dd_phys->dd_clones,
2827 origin_head->ds_object, tx));
2828 if (dd->dd_phys->dd_clones == 0) {
2829 dd->dd_phys->dd_clones = zap_create(dp->dp_meta_objset,
2830 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
2831 }
2832 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2833 dd->dd_phys->dd_clones, origin_head->ds_object, tx));
2834
2835 }
2836
2837 /* move snapshots to this dir */
2838 for (snap = list_head(&pa->shared_snaps); snap;
2839 snap = list_next(&pa->shared_snaps, snap)) {
2840 dsl_dataset_t *ds = snap->ds;
2841
2842 /* unregister props as dsl_dir is changing */
2843 if (ds->ds_objset) {
2844 dmu_objset_evict(ds->ds_objset);
2845 ds->ds_objset = NULL;
2846 }
2847 /* move snap name entry */
2848 VERIFY(0 == dsl_dataset_get_snapname(ds));
2849 VERIFY(0 == dsl_dataset_snap_remove(origin_head,
2850 ds->ds_snapname, tx));
2851 VERIFY(0 == zap_add(dp->dp_meta_objset,
2852 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname,
2853 8, 1, &ds->ds_object, tx));
2854
2855 /* change containing dsl_dir */
2856 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2857 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object);
2858 ds->ds_phys->ds_dir_obj = dd->dd_object;
2859 ASSERT3P(ds->ds_dir, ==, odd);
2860 dsl_dir_close(ds->ds_dir, ds);
2861 VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object,
2862 NULL, ds, &ds->ds_dir));
2863
2864 /* move any clone references */
2865 if (ds->ds_phys->ds_next_clones_obj &&
2866 spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2867 zap_cursor_t zc;
2868 zap_attribute_t za;
2869
2870 for (zap_cursor_init(&zc, dp->dp_meta_objset,
2871 ds->ds_phys->ds_next_clones_obj);
2872 zap_cursor_retrieve(&zc, &za) == 0;
2873 zap_cursor_advance(&zc)) {
2874 dsl_dataset_t *cnds;
2875 uint64_t o;
2876
2877 if (za.za_first_integer == oldnext_obj) {
2878 /*
2879 * We've already moved the
2880 * origin's reference.
2881 */
2882 continue;
2883 }
2884
2885 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
2886 za.za_first_integer, FTAG, &cnds));
2887 o = cnds->ds_dir->dd_phys->dd_head_dataset_obj;
2888
2889 VERIFY3U(zap_remove_int(dp->dp_meta_objset,
2890 odd->dd_phys->dd_clones, o, tx), ==, 0);
2891 VERIFY3U(zap_add_int(dp->dp_meta_objset,
2892 dd->dd_phys->dd_clones, o, tx), ==, 0);
2893 dsl_dataset_rele(cnds, FTAG);
2894 }
2895 zap_cursor_fini(&zc);
2896 }
2897
2898 ASSERT3U(dsl_prop_numcb(ds), ==, 0);
2899 }
2900
2901 /*
2902 * Change space accounting.
2903 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either
2904 * both be valid, or both be 0 (resulting in delta == 0). This
2905 * is true for each of {clone,origin} independently.
2906 */
2907
2908 delta = pa->cloneusedsnap -
2909 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2910 ASSERT3S(delta, >=, 0);
2911 ASSERT3U(pa->used, >=, delta);
2912 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx);
2913 dsl_dir_diduse_space(dd, DD_USED_HEAD,
2914 pa->used - delta, pa->comp, pa->uncomp, tx);
2915
2916 delta = pa->originusedsnap -
2917 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2918 ASSERT3S(delta, <=, 0);
2919 ASSERT3U(pa->used, >=, -delta);
2920 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx);
2921 dsl_dir_diduse_space(odd, DD_USED_HEAD,
2922 -pa->used - delta, -pa->comp, -pa->uncomp, tx);
2923
2924 origin_ds->ds_phys->ds_unique_bytes = pa->unique;
2925
2926 /* log history record */
2927 spa_history_log_internal(LOG_DS_PROMOTE, dd->dd_pool->dp_spa, tx,
2928 "dataset = %llu", hds->ds_object);
2929
2930 dsl_dir_close(odd, FTAG);
2931}
2932
2933static char *snaplist_tag = "snaplist";
2934/*
2935 * Make a list of dsl_dataset_t's for the snapshots between first_obj
2936 * (exclusive) and last_obj (inclusive). The list will be in reverse
2937 * order (last_obj will be the list_head()). If first_obj == 0, do all
2938 * snapshots back to this dataset's origin.
2939 */
2940static int
2941snaplist_make(dsl_pool_t *dp, boolean_t own,
2942 uint64_t first_obj, uint64_t last_obj, list_t *l)
2943{
2944 uint64_t obj = last_obj;
2945
2946 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock));
2947
2948 list_create(l, sizeof (struct promotenode),
2949 offsetof(struct promotenode, link));
2950
2951 while (obj != first_obj) {
2952 dsl_dataset_t *ds;
2953 struct promotenode *snap;
2954 int err;
2955
2956 if (own) {
2957 err = dsl_dataset_own_obj(dp, obj,
2958 0, snaplist_tag, &ds);
2959 if (err == 0)
2960 dsl_dataset_make_exclusive(ds, snaplist_tag);
2961 } else {
2962 err = dsl_dataset_hold_obj(dp, obj, snaplist_tag, &ds);
2963 }
2964 if (err == ENOENT) {
2965 /* lost race with snapshot destroy */
2966 struct promotenode *last = list_tail(l);
2967 ASSERT(obj != last->ds->ds_phys->ds_prev_snap_obj);
2968 obj = last->ds->ds_phys->ds_prev_snap_obj;
2969 continue;
2970 } else if (err) {
2971 return (err);
2972 }
2973
2974 if (first_obj == 0)
2975 first_obj = ds->ds_dir->dd_phys->dd_origin_obj;
2976
2977 snap = kmem_alloc(sizeof (struct promotenode), KM_SLEEP);
2978 snap->ds = ds;
2979 list_insert_tail(l, snap);
2980 obj = ds->ds_phys->ds_prev_snap_obj;
2981 }
2982
2983 return (0);
2984}
2985
2986static int
2987snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep)
2988{
2989 struct promotenode *snap;
2990
2991 *spacep = 0;
2992 for (snap = list_head(l); snap; snap = list_next(l, snap)) {
2993 uint64_t used, comp, uncomp;
2994 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2995 mintxg, UINT64_MAX, &used, &comp, &uncomp);
2996 *spacep += used;
2997 }
2998 return (0);
2999}
3000
3001static void
3002snaplist_destroy(list_t *l, boolean_t own)
3003{
3004 struct promotenode *snap;
3005
3006 if (!l || !list_link_active(&l->list_head))
3007 return;
3008
3009 while ((snap = list_tail(l)) != NULL) {
3010 list_remove(l, snap);
3011 if (own)
3012 dsl_dataset_disown(snap->ds, snaplist_tag);
3013 else
3014 dsl_dataset_rele(snap->ds, snaplist_tag);
3015 kmem_free(snap, sizeof (struct promotenode));
3016 }
3017 list_destroy(l);
3018}
3019
3020/*
3021 * Promote a clone. Nomenclature note:
3022 * "clone" or "cds": the original clone which is being promoted
3023 * "origin" or "ods": the snapshot which is originally clone's origin
3024 * "origin head" or "ohds": the dataset which is the head
3025 * (filesystem/volume) for the origin
3026 * "origin origin": the origin of the origin's filesystem (typically
3027 * NULL, indicating that the clone is not a clone of a clone).
3028 */
3029int
3030dsl_dataset_promote(const char *name, char *conflsnap)
3031{
3032 dsl_dataset_t *ds;
3033 dsl_dir_t *dd;
3034 dsl_pool_t *dp;
3035 dmu_object_info_t doi;
3036 struct promotearg pa = { 0 };
3037 struct promotenode *snap;
3038 int err;
3039
3040 err = dsl_dataset_hold(name, FTAG, &ds);
3041 if (err)
3042 return (err);
3043 dd = ds->ds_dir;
3044 dp = dd->dd_pool;
3045
3046 err = dmu_object_info(dp->dp_meta_objset,
3047 ds->ds_phys->ds_snapnames_zapobj, &doi);
3048 if (err) {
3049 dsl_dataset_rele(ds, FTAG);
3050 return (err);
3051 }
3052
3053 if (dsl_dataset_is_snapshot(ds) || dd->dd_phys->dd_origin_obj == 0) {
3054 dsl_dataset_rele(ds, FTAG);
3055 return (EINVAL);
3056 }
3057
3058 /*
3059 * We are going to inherit all the snapshots taken before our
3060 * origin (i.e., our new origin will be our parent's origin).
3061 * Take ownership of them so that we can rename them into our
3062 * namespace.
3063 */
3064 rw_enter(&dp->dp_config_rwlock, RW_READER);
3065
3066 err = snaplist_make(dp, B_TRUE, 0, dd->dd_phys->dd_origin_obj,
3067 &pa.shared_snaps);
3068 if (err != 0)
3069 goto out;
3070
3071 err = snaplist_make(dp, B_FALSE, 0, ds->ds_object, &pa.clone_snaps);
3072 if (err != 0)
3073 goto out;
3074
3075 snap = list_head(&pa.shared_snaps);
3076 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj);
3077 err = snaplist_make(dp, B_FALSE, dd->dd_phys->dd_origin_obj,
3078 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj, &pa.origin_snaps);
3079 if (err != 0)
3080 goto out;
3081
3082 if (snap->ds->ds_dir->dd_phys->dd_origin_obj != 0) {
3083 err = dsl_dataset_hold_obj(dp,
3084 snap->ds->ds_dir->dd_phys->dd_origin_obj,
3085 FTAG, &pa.origin_origin);
3086 if (err != 0)
3087 goto out;
3088 }
3089
3090out:
3091 rw_exit(&dp->dp_config_rwlock);
3092
3093 /*
3094 * Add in 128x the snapnames zapobj size, since we will be moving
3095 * a bunch of snapnames to the promoted ds, and dirtying their
3096 * bonus buffers.
3097 */
3098 if (err == 0) {
3099 err = dsl_sync_task_do(dp, dsl_dataset_promote_check,
3100 dsl_dataset_promote_sync, ds, &pa,
3101 2 + 2 * doi.doi_physical_blocks_512);
3102 if (err && pa.err_ds && conflsnap)
3103 (void) strncpy(conflsnap, pa.err_ds, MAXNAMELEN);
3104 }
3105
3106 snaplist_destroy(&pa.shared_snaps, B_TRUE);
3107 snaplist_destroy(&pa.clone_snaps, B_FALSE);
3108 snaplist_destroy(&pa.origin_snaps, B_FALSE);
3109 if (pa.origin_origin)
3110 dsl_dataset_rele(pa.origin_origin, FTAG);
3111 dsl_dataset_rele(ds, FTAG);
3112 return (err);
3113}
3114
3115struct cloneswaparg {
3116 dsl_dataset_t *cds; /* clone dataset */
3117 dsl_dataset_t *ohds; /* origin's head dataset */
3118 boolean_t force;
3119 int64_t unused_refres_delta; /* change in unconsumed refreservation */
3120};
3121
3122/* ARGSUSED */
3123static int
3124dsl_dataset_clone_swap_check(void *arg1, void *arg2, dmu_tx_t *tx)
3125{
3126 struct cloneswaparg *csa = arg1;
3127
3128 /* they should both be heads */
3129 if (dsl_dataset_is_snapshot(csa->cds) ||
3130 dsl_dataset_is_snapshot(csa->ohds))
3131 return (EINVAL);
3132
3133 /* the branch point should be just before them */
3134 if (csa->cds->ds_prev != csa->ohds->ds_prev)
3135 return (EINVAL);
3136
3137 /* cds should be the clone (unless they are unrelated) */
3138 if (csa->cds->ds_prev != NULL &&
3139 csa->cds->ds_prev != csa->cds->ds_dir->dd_pool->dp_origin_snap &&
3140 csa->ohds->ds_object !=
3141 csa->cds->ds_prev->ds_phys->ds_next_snap_obj)
3142 return (EINVAL);
3143
3144 /* the clone should be a child of the origin */
3145 if (csa->cds->ds_dir->dd_parent != csa->ohds->ds_dir)
3146 return (EINVAL);
3147
3148 /* ohds shouldn't be modified unless 'force' */
3149 if (!csa->force && dsl_dataset_modified_since_lastsnap(csa->ohds))
3150 return (ETXTBSY);
3151
3152 /* adjust amount of any unconsumed refreservation */
3153 csa->unused_refres_delta =
3154 (int64_t)MIN(csa->ohds->ds_reserved,
3155 csa->ohds->ds_phys->ds_unique_bytes) -
3156 (int64_t)MIN(csa->ohds->ds_reserved,
3157 csa->cds->ds_phys->ds_unique_bytes);
3158
3159 if (csa->unused_refres_delta > 0 &&
3160 csa->unused_refres_delta >
3161 dsl_dir_space_available(csa->ohds->ds_dir, NULL, 0, TRUE))
3162 return (ENOSPC);
3163
3164 if (csa->ohds->ds_quota != 0 &&
3165 csa->cds->ds_phys->ds_unique_bytes > csa->ohds->ds_quota)
3166 return (EDQUOT);
3167
3168 return (0);
3169}
3170
3171/* ARGSUSED */
3172static void
3173dsl_dataset_clone_swap_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3174{
3175 struct cloneswaparg *csa = arg1;
3176 dsl_pool_t *dp = csa->cds->ds_dir->dd_pool;
3177
3178 ASSERT(csa->cds->ds_reserved == 0);
3179 ASSERT(csa->ohds->ds_quota == 0 ||
3180 csa->cds->ds_phys->ds_unique_bytes <= csa->ohds->ds_quota);
3181
3182 dmu_buf_will_dirty(csa->cds->ds_dbuf, tx);
3183 dmu_buf_will_dirty(csa->ohds->ds_dbuf, tx);
3184
3185 if (csa->cds->ds_objset != NULL) {
3186 dmu_objset_evict(csa->cds->ds_objset);
3187 csa->cds->ds_objset = NULL;
3188 }
3189
3190 if (csa->ohds->ds_objset != NULL) {
3191 dmu_objset_evict(csa->ohds->ds_objset);
3192 csa->ohds->ds_objset = NULL;
3193 }
3194
3195 /*
3196 * Reset origin's unique bytes, if it exists.
3197 */
3198 if (csa->cds->ds_prev) {
3199 dsl_dataset_t *origin = csa->cds->ds_prev;
3200 uint64_t comp, uncomp;
3201
3202 dmu_buf_will_dirty(origin->ds_dbuf, tx);
3203 dsl_deadlist_space_range(&csa->cds->ds_deadlist,
3204 origin->ds_phys->ds_prev_snap_txg, UINT64_MAX,
3205 &origin->ds_phys->ds_unique_bytes, &comp, &uncomp);
3206 }
3207
3208 /* swap blkptrs */
3209 {
3210 blkptr_t tmp;
3211 tmp = csa->ohds->ds_phys->ds_bp;
3212 csa->ohds->ds_phys->ds_bp = csa->cds->ds_phys->ds_bp;
3213 csa->cds->ds_phys->ds_bp = tmp;
3214 }
3215
3216 /* set dd_*_bytes */
3217 {
3218 int64_t dused, dcomp, duncomp;
3219 uint64_t cdl_used, cdl_comp, cdl_uncomp;
3220 uint64_t odl_used, odl_comp, odl_uncomp;
3221
3222 ASSERT3U(csa->cds->ds_dir->dd_phys->
3223 dd_used_breakdown[DD_USED_SNAP], ==, 0);
3224
3225 dsl_deadlist_space(&csa->cds->ds_deadlist,
3226 &cdl_used, &cdl_comp, &cdl_uncomp);
3227 dsl_deadlist_space(&csa->ohds->ds_deadlist,
3228 &odl_used, &odl_comp, &odl_uncomp);
3229
3230 dused = csa->cds->ds_phys->ds_used_bytes + cdl_used -
3231 (csa->ohds->ds_phys->ds_used_bytes + odl_used);
3232 dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp -
3233 (csa->ohds->ds_phys->ds_compressed_bytes + odl_comp);
3234 duncomp = csa->cds->ds_phys->ds_uncompressed_bytes +
3235 cdl_uncomp -
3236 (csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp);
3237
3238 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD,
3239 dused, dcomp, duncomp, tx);
3240 dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD,
3241 -dused, -dcomp, -duncomp, tx);
3242
3243 /*
3244 * The difference in the space used by snapshots is the
3245 * difference in snapshot space due to the head's
3246 * deadlist (since that's the only thing that's
3247 * changing that affects the snapused).
3248 */
3249 dsl_deadlist_space_range(&csa->cds->ds_deadlist,
3250 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX,
3251 &cdl_used, &cdl_comp, &cdl_uncomp);
3252 dsl_deadlist_space_range(&csa->ohds->ds_deadlist,
3253 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX,
3254 &odl_used, &odl_comp, &odl_uncomp);
3255 dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used,
3256 DD_USED_HEAD, DD_USED_SNAP, tx);
3257 }
3258
3259 /* swap ds_*_bytes */
3260 SWITCH64(csa->ohds->ds_phys->ds_used_bytes,
3261 csa->cds->ds_phys->ds_used_bytes);
3262 SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes,
3263 csa->cds->ds_phys->ds_compressed_bytes);
3264 SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes,
3265 csa->cds->ds_phys->ds_uncompressed_bytes);
3266 SWITCH64(csa->ohds->ds_phys->ds_unique_bytes,
3267 csa->cds->ds_phys->ds_unique_bytes);
3268
3269 /* apply any parent delta for change in unconsumed refreservation */
3270 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV,
3271 csa->unused_refres_delta, 0, 0, tx);
3272
3273 /*
3274 * Swap deadlists.
3275 */
3276 dsl_deadlist_close(&csa->cds->ds_deadlist);
3277 dsl_deadlist_close(&csa->ohds->ds_deadlist);
3278 SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj,
3279 csa->cds->ds_phys->ds_deadlist_obj);
3280 dsl_deadlist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset,
3281 csa->cds->ds_phys->ds_deadlist_obj);
3282 dsl_deadlist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset,
3283 csa->ohds->ds_phys->ds_deadlist_obj);
3284
3285 dsl_scan_ds_clone_swapped(csa->ohds, csa->cds, tx);
3286}
3287
3288/*
3289 * Swap 'clone' with its origin head datasets. Used at the end of "zfs
3290 * recv" into an existing fs to swizzle the file system to the new
3291 * version, and by "zfs rollback". Can also be used to swap two
3292 * independent head datasets if neither has any snapshots.
3293 */
3294int
3295dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head,
3296 boolean_t force)
3297{
3298 struct cloneswaparg csa;
3299 int error;
3300
3301 ASSERT(clone->ds_owner);
3302 ASSERT(origin_head->ds_owner);
3303retry:
3304 /*
3305 * Need exclusive access for the swap. If we're swapping these
3306 * datasets back after an error, we already hold the locks.
3307 */
3308 if (!RW_WRITE_HELD(&clone->ds_rwlock))
3309 rw_enter(&clone->ds_rwlock, RW_WRITER);
3310 if (!RW_WRITE_HELD(&origin_head->ds_rwlock) &&
3311 !rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) {
3312 rw_exit(&clone->ds_rwlock);
3313 rw_enter(&origin_head->ds_rwlock, RW_WRITER);
3314 if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) {
3315 rw_exit(&origin_head->ds_rwlock);
3316 goto retry;
3317 }
3318 }
3319 csa.cds = clone;
3320 csa.ohds = origin_head;
3321 csa.force = force;
3322 error = dsl_sync_task_do(clone->ds_dir->dd_pool,
3323 dsl_dataset_clone_swap_check,
3324 dsl_dataset_clone_swap_sync, &csa, NULL, 9);
3325 return (error);
3326}
3327
3328/*
3329 * Given a pool name and a dataset object number in that pool,
3330 * return the name of that dataset.
3331 */
3332int
3333dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf)
3334{
3335 spa_t *spa;
3336 dsl_pool_t *dp;
3337 dsl_dataset_t *ds;
3338 int error;
3339
3340 if ((error = spa_open(pname, &spa, FTAG)) != 0)
3341 return (error);
3342 dp = spa_get_dsl(spa);
3343 rw_enter(&dp->dp_config_rwlock, RW_READER);
3344 if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) {
3345 dsl_dataset_name(ds, buf);
3346 dsl_dataset_rele(ds, FTAG);
3347 }
3348 rw_exit(&dp->dp_config_rwlock);
3349 spa_close(spa, FTAG);
3350
3351 return (error);
3352}
3353
3354int
3355dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota,
3356 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv)
3357{
3358 int error = 0;
3359
3360 ASSERT3S(asize, >, 0);
3361
3362 /*
3363 * *ref_rsrv is the portion of asize that will come from any
3364 * unconsumed refreservation space.
3365 */
3366 *ref_rsrv = 0;
3367
3368 mutex_enter(&ds->ds_lock);
3369 /*
3370 * Make a space adjustment for reserved bytes.
3371 */
3372 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) {
3373 ASSERT3U(*used, >=,
3374 ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
3375 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
3376 *ref_rsrv =
3377 asize - MIN(asize, parent_delta(ds, asize + inflight));
3378 }
3379
3380 if (!check_quota || ds->ds_quota == 0) {
3381 mutex_exit(&ds->ds_lock);
3382 return (0);
3383 }
3384 /*
3385 * If they are requesting more space, and our current estimate
3386 * is over quota, they get to try again unless the actual
3387 * on-disk is over quota and there are no pending changes (which
3388 * may free up space for us).
3389 */
3390 if (ds->ds_phys->ds_used_bytes + inflight >= ds->ds_quota) {
3391 if (inflight > 0 || ds->ds_phys->ds_used_bytes < ds->ds_quota)
3392 error = ERESTART;
3393 else
3394 error = EDQUOT;
3395 }
3396 mutex_exit(&ds->ds_lock);
3397
3398 return (error);
3399}
3400
3401/* ARGSUSED */
3402static int
3403dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx)
3404{
3405 dsl_dataset_t *ds = arg1;
3406 dsl_prop_setarg_t *psa = arg2;
3407 int err;
3408
3409 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA)
3410 return (ENOTSUP);
3411
3412 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0)
3413 return (err);
3414
3415 if (psa->psa_effective_value == 0)
3416 return (0);
3417
3418 if (psa->psa_effective_value < ds->ds_phys->ds_used_bytes ||
3419 psa->psa_effective_value < ds->ds_reserved)
3420 return (ENOSPC);
3421
3422 return (0);
3423}
3424
3425extern void dsl_prop_set_sync(void *, void *, dmu_tx_t *);
3426
3427void
3428dsl_dataset_set_quota_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3429{
3430 dsl_dataset_t *ds = arg1;
3431 dsl_prop_setarg_t *psa = arg2;
3432 uint64_t effective_value = psa->psa_effective_value;
3433
3434 dsl_prop_set_sync(ds, psa, tx);
3435 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa);
3436
3437 if (ds->ds_quota != effective_value) {
3438 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3439 ds->ds_quota = effective_value;
3440
3441 spa_history_log_internal(LOG_DS_REFQUOTA,
3442 ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu ",
3443 (longlong_t)ds->ds_quota, ds->ds_object);
3444 }
3445}
3446
3447int
3448dsl_dataset_set_quota(const char *dsname, zprop_source_t source, uint64_t quota)
3449{
3450 dsl_dataset_t *ds;
3451 dsl_prop_setarg_t psa;
3452 int err;
3453
3454 dsl_prop_setarg_init_uint64(&psa, "refquota", source, "a);
3455
3456 err = dsl_dataset_hold(dsname, FTAG, &ds);
3457 if (err)
3458 return (err);
3459
3460 /*
3461 * If someone removes a file, then tries to set the quota, we
3462 * want to make sure the file freeing takes effect.
3463 */
3464 txg_wait_open(ds->ds_dir->dd_pool, 0);
3465
3466 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
3467 dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync,
3468 ds, &psa, 0);
3469
3470 dsl_dataset_rele(ds, FTAG);
3471 return (err);
3472}
3473
3474static int
3475dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx)
3476{
3477 dsl_dataset_t *ds = arg1;
3478 dsl_prop_setarg_t *psa = arg2;
3479 uint64_t effective_value;
3480 uint64_t unique;
3481 int err;
3482
3483 if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
3484 SPA_VERSION_REFRESERVATION)
3485 return (ENOTSUP);
3486
3487 if (dsl_dataset_is_snapshot(ds))
3488 return (EINVAL);
3489
3490 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0)
3491 return (err);
3492
3493 effective_value = psa->psa_effective_value;
3494
3495 /*
3496 * If we are doing the preliminary check in open context, the
3497 * space estimates may be inaccurate.
3498 */
3499 if (!dmu_tx_is_syncing(tx))
3500 return (0);
3501
3502 mutex_enter(&ds->ds_lock);
3503 if (!DS_UNIQUE_IS_ACCURATE(ds))
3504 dsl_dataset_recalc_head_uniq(ds);
3505 unique = ds->ds_phys->ds_unique_bytes;
3506 mutex_exit(&ds->ds_lock);
3507
3508 if (MAX(unique, effective_value) > MAX(unique, ds->ds_reserved)) {
3509 uint64_t delta = MAX(unique, effective_value) -
3510 MAX(unique, ds->ds_reserved);
3511
3512 if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
3513 return (ENOSPC);
3514 if (ds->ds_quota > 0 &&
3515 effective_value > ds->ds_quota)
3516 return (ENOSPC);
3517 }
3518
3519 return (0);
3520}
3521
3522static void
3523dsl_dataset_set_reservation_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3524{
3525 dsl_dataset_t *ds = arg1;
3526 dsl_prop_setarg_t *psa = arg2;
3527 uint64_t effective_value = psa->psa_effective_value;
3528 uint64_t unique;
3529 int64_t delta;
3530
3531 dsl_prop_set_sync(ds, psa, tx);
3532 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa);
3533
3534 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3535
3536 mutex_enter(&ds->ds_dir->dd_lock);
3537 mutex_enter(&ds->ds_lock);
3538 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
3539 unique = ds->ds_phys->ds_unique_bytes;
3540 delta = MAX(0, (int64_t)(effective_value - unique)) -
3541 MAX(0, (int64_t)(ds->ds_reserved - unique));
3542 ds->ds_reserved = effective_value;
3543 mutex_exit(&ds->ds_lock);
3544
3545 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx);
3546 mutex_exit(&ds->ds_dir->dd_lock);
3547
3548 spa_history_log_internal(LOG_DS_REFRESERV,
3549 ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu",
3550 (longlong_t)effective_value, ds->ds_object);
3551}
3552
3553int
3554dsl_dataset_set_reservation(const char *dsname, zprop_source_t source,
3555 uint64_t reservation)
3556{
3557 dsl_dataset_t *ds;
3558 dsl_prop_setarg_t psa;
3559 int err;
3560
3561 dsl_prop_setarg_init_uint64(&psa, "refreservation", source,
3562 &reservation);
3563
3564 err = dsl_dataset_hold(dsname, FTAG, &ds);
3565 if (err)
3566 return (err);
3567
3568 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
3569 dsl_dataset_set_reservation_check,
3570 dsl_dataset_set_reservation_sync, ds, &psa, 0);
3571
3572 dsl_dataset_rele(ds, FTAG);
3573 return (err);
3574}
3575
3576typedef struct zfs_hold_cleanup_arg {
3577 dsl_pool_t *dp;
3578 uint64_t dsobj;
3579 char htag[MAXNAMELEN];
3580} zfs_hold_cleanup_arg_t;
3581
3582static void
3583dsl_dataset_user_release_onexit(void *arg)
3584{
3585 zfs_hold_cleanup_arg_t *ca = arg;
3586
3587 (void) dsl_dataset_user_release_tmp(ca->dp, ca->dsobj, ca->htag,
3588 B_TRUE);
3589 kmem_free(ca, sizeof (zfs_hold_cleanup_arg_t));
3590}
3591
3592void
3593dsl_register_onexit_hold_cleanup(dsl_dataset_t *ds, const char *htag,
3594 minor_t minor)
3595{
3596 zfs_hold_cleanup_arg_t *ca;
3597
3598 ca = kmem_alloc(sizeof (zfs_hold_cleanup_arg_t), KM_SLEEP);
3599 ca->dp = ds->ds_dir->dd_pool;
3600 ca->dsobj = ds->ds_object;
3601 (void) strlcpy(ca->htag, htag, sizeof (ca->htag));
3602 VERIFY3U(0, ==, zfs_onexit_add_cb(minor,
3603 dsl_dataset_user_release_onexit, ca, NULL));
3604}
3605
3606/*
3607 * If you add new checks here, you may need to add
3608 * additional checks to the "temporary" case in
3609 * snapshot_check() in dmu_objset.c.
3610 */
3611static int
3612dsl_dataset_user_hold_check(void *arg1, void *arg2, dmu_tx_t *tx)
3613{
3614 dsl_dataset_t *ds = arg1;
3615 struct dsl_ds_holdarg *ha = arg2;
3616 char *htag = ha->htag;
3617 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3618 int error = 0;
3619
3620 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS)
3621 return (ENOTSUP);
3622
3623 if (!dsl_dataset_is_snapshot(ds))
3624 return (EINVAL);
3625
3626 /* tags must be unique */
3627 mutex_enter(&ds->ds_lock);
3628 if (ds->ds_phys->ds_userrefs_obj) {
3629 error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj, htag,
3630 8, 1, tx);
3631 if (error == 0)
3632 error = EEXIST;
3633 else if (error == ENOENT)
3634 error = 0;
3635 }
3636 mutex_exit(&ds->ds_lock);
3637
3638 if (error == 0 && ha->temphold &&
3639 strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN)
3640 error = E2BIG;
3641
3642 return (error);
3643}
3644
3645void
3646dsl_dataset_user_hold_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3647{
3648 dsl_dataset_t *ds = arg1;
3649 struct dsl_ds_holdarg *ha = arg2;
3650 char *htag = ha->htag;
3651 dsl_pool_t *dp = ds->ds_dir->dd_pool;
3652 objset_t *mos = dp->dp_meta_objset;
3653 uint64_t now = gethrestime_sec();
3654 uint64_t zapobj;
3655
3656 mutex_enter(&ds->ds_lock);
3657 if (ds->ds_phys->ds_userrefs_obj == 0) {
3658 /*
3659 * This is the first user hold for this dataset. Create
3660 * the userrefs zap object.
3661 */
3662 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3663 zapobj = ds->ds_phys->ds_userrefs_obj =
3664 zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx);
3665 } else {
3666 zapobj = ds->ds_phys->ds_userrefs_obj;
3667 }
3668 ds->ds_userrefs++;
3669 mutex_exit(&ds->ds_lock);
3670
3671 VERIFY(0 == zap_add(mos, zapobj, htag, 8, 1, &now, tx));
3672
3673 if (ha->temphold) {
3674 VERIFY(0 == dsl_pool_user_hold(dp, ds->ds_object,
3675 htag, &now, tx));
3676 }
3677
3678 spa_history_log_internal(LOG_DS_USER_HOLD,
3679 dp->dp_spa, tx, "<%s> temp = %d dataset = %llu", htag,
3680 (int)ha->temphold, ds->ds_object);
3681}
3682
3683static int
3684dsl_dataset_user_hold_one(const char *dsname, void *arg)
3685{
3686 struct dsl_ds_holdarg *ha = arg;
3687 dsl_dataset_t *ds;
3688 int error;
3689 char *name;
3690
3691 /* alloc a buffer to hold dsname@snapname plus terminating NULL */
3692 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3693 error = dsl_dataset_hold(name, ha->dstg, &ds);
3694 strfree(name);
3695 if (error == 0) {
3696 ha->gotone = B_TRUE;
3697 dsl_sync_task_create(ha->dstg, dsl_dataset_user_hold_check,
3698 dsl_dataset_user_hold_sync, ds, ha, 0);
3699 } else if (error == ENOENT && ha->recursive) {
3700 error = 0;
3701 } else {
3702 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3703 }
3704 return (error);
3705}
3706
3707int
3708dsl_dataset_user_hold_for_send(dsl_dataset_t *ds, char *htag,
3709 boolean_t temphold)
3710{
3711 struct dsl_ds_holdarg *ha;
3712 int error;
3713
3714 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3715 ha->htag = htag;
3716 ha->temphold = temphold;
3717 error = dsl_sync_task_do(ds->ds_dir->dd_pool,
3718 dsl_dataset_user_hold_check, dsl_dataset_user_hold_sync,
3719 ds, ha, 0);
3720 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3721
3722 return (error);
3723}
3724
3725int
3726dsl_dataset_user_hold(char *dsname, char *snapname, char *htag,
3727 boolean_t recursive, boolean_t temphold, int cleanup_fd)
3728{
3729 struct dsl_ds_holdarg *ha;
3730 dsl_sync_task_t *dst;
3731 spa_t *spa;
3732 int error;
3733 minor_t minor = 0;
3734
3735 if (cleanup_fd != -1) {
3736 /* Currently we only support cleanup-on-exit of tempholds. */
3737 if (!temphold)
3738 return (EINVAL);
3739 error = zfs_onexit_fd_hold(cleanup_fd, &minor);
3740 if (error)
3741 return (error);
3742 }
3743
3744 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3745
3746 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3747
3748 error = spa_open(dsname, &spa, FTAG);
3749 if (error) {
3750 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3751 if (cleanup_fd != -1)
3752 zfs_onexit_fd_rele(cleanup_fd);
3753 return (error);
3754 }
3755
3756 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
3757 ha->htag = htag;
3758 ha->snapname = snapname;
3759 ha->recursive = recursive;
3760 ha->temphold = temphold;
3761
3762 if (recursive) {
3763 error = dmu_objset_find(dsname, dsl_dataset_user_hold_one,
3764 ha, DS_FIND_CHILDREN);
3765 } else {
3766 error = dsl_dataset_user_hold_one(dsname, ha);
3767 }
3768 if (error == 0)
3769 error = dsl_sync_task_group_wait(ha->dstg);
3770
3771 for (dst = list_head(&ha->dstg->dstg_tasks); dst;
3772 dst = list_next(&ha->dstg->dstg_tasks, dst)) {
3773 dsl_dataset_t *ds = dst->dst_arg1;
3774
3775 if (dst->dst_err) {
3776 dsl_dataset_name(ds, ha->failed);
3777 *strchr(ha->failed, '@') = '\0';
3778 } else if (error == 0 && minor != 0 && temphold) {
3779 /*
3780 * If this hold is to be released upon process exit,
3781 * register that action now.
3782 */
3783 dsl_register_onexit_hold_cleanup(ds, htag, minor);
3784 }
3785 dsl_dataset_rele(ds, ha->dstg);
3786 }
3787
3788 if (error == 0 && recursive && !ha->gotone)
3789 error = ENOENT;
3790
3791 if (error)
3792 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed));
3793
3794 dsl_sync_task_group_destroy(ha->dstg);
3795
3796 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3797 spa_close(spa, FTAG);
3798 if (cleanup_fd != -1)
3799 zfs_onexit_fd_rele(cleanup_fd);
3800 return (error);
3801}
3802
3803struct dsl_ds_releasearg {
3804 dsl_dataset_t *ds;
3805 const char *htag;
3806 boolean_t own; /* do we own or just hold ds? */
3807};
3808
3809static int
3810dsl_dataset_release_might_destroy(dsl_dataset_t *ds, const char *htag,
3811 boolean_t *might_destroy)
3812{
3813 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3814 uint64_t zapobj;
3815 uint64_t tmp;
3816 int error;
3817
3818 *might_destroy = B_FALSE;
3819
3820 mutex_enter(&ds->ds_lock);
3821 zapobj = ds->ds_phys->ds_userrefs_obj;
3822 if (zapobj == 0) {
3823 /* The tag can't possibly exist */
3824 mutex_exit(&ds->ds_lock);
3825 return (ESRCH);
3826 }
3827
3828 /* Make sure the tag exists */
3829 error = zap_lookup(mos, zapobj, htag, 8, 1, &tmp);
3830 if (error) {
3831 mutex_exit(&ds->ds_lock);
3832 if (error == ENOENT)
3833 error = ESRCH;
3834 return (error);
3835 }
3836
3837 if (ds->ds_userrefs == 1 && ds->ds_phys->ds_num_children == 1 &&
3838 DS_IS_DEFER_DESTROY(ds))
3839 *might_destroy = B_TRUE;
3840
3841 mutex_exit(&ds->ds_lock);
3842 return (0);
3843}
3844
3845static int
3846dsl_dataset_user_release_check(void *arg1, void *tag, dmu_tx_t *tx)
3847{
3848 struct dsl_ds_releasearg *ra = arg1;
3849 dsl_dataset_t *ds = ra->ds;
3850 boolean_t might_destroy;
3851 int error;
3852
3853 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS)
3854 return (ENOTSUP);
3855
3856 error = dsl_dataset_release_might_destroy(ds, ra->htag, &might_destroy);
3857 if (error)
3858 return (error);
3859
3860 if (might_destroy) {
3861 struct dsl_ds_destroyarg dsda = {0};
3862
3863 if (dmu_tx_is_syncing(tx)) {
3864 /*
3865 * If we're not prepared to remove the snapshot,
3866 * we can't allow the release to happen right now.
3867 */
3868 if (!ra->own)
3869 return (EBUSY);
3870 }
3871 dsda.ds = ds;
3872 dsda.releasing = B_TRUE;
3873 return (dsl_dataset_destroy_check(&dsda, tag, tx));
3874 }
3875
3876 return (0);
3877}
3878
3879static void
3880dsl_dataset_user_release_sync(void *arg1, void *tag, dmu_tx_t *tx)
3881{
3882 struct dsl_ds_releasearg *ra = arg1;
3883 dsl_dataset_t *ds = ra->ds;
3884 dsl_pool_t *dp = ds->ds_dir->dd_pool;
3885 objset_t *mos = dp->dp_meta_objset;
3886 uint64_t zapobj;
3887 uint64_t dsobj = ds->ds_object;
3888 uint64_t refs;
3889 int error;
3890
3891 mutex_enter(&ds->ds_lock);
3892 ds->ds_userrefs--;
3893 refs = ds->ds_userrefs;
3894 mutex_exit(&ds->ds_lock);
3895 error = dsl_pool_user_release(dp, ds->ds_object, ra->htag, tx);
3896 VERIFY(error == 0 || error == ENOENT);
3897 zapobj = ds->ds_phys->ds_userrefs_obj;
3898 VERIFY(0 == zap_remove(mos, zapobj, ra->htag, tx));
3899 if (ds->ds_userrefs == 0 && ds->ds_phys->ds_num_children == 1 &&
3900 DS_IS_DEFER_DESTROY(ds)) {
3901 struct dsl_ds_destroyarg dsda = {0};
3902
3903 ASSERT(ra->own);
3904 dsda.ds = ds;
3905 dsda.releasing = B_TRUE;
3906 /* We already did the destroy_check */
3907 dsl_dataset_destroy_sync(&dsda, tag, tx);
3908 }
3909
3910 spa_history_log_internal(LOG_DS_USER_RELEASE,
3911 dp->dp_spa, tx, "<%s> %lld dataset = %llu",
3912 ra->htag, (longlong_t)refs, dsobj);
3913}
3914
3915static int
3916dsl_dataset_user_release_one(const char *dsname, void *arg)
3917{
3918 struct dsl_ds_holdarg *ha = arg;
3919 struct dsl_ds_releasearg *ra;
3920 dsl_dataset_t *ds;
3921 int error;
3922 void *dtag = ha->dstg;
3923 char *name;
3924 boolean_t own = B_FALSE;
3925 boolean_t might_destroy;
3926
3927 /* alloc a buffer to hold dsname@snapname, plus the terminating NULL */
3928 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3929 error = dsl_dataset_hold(name, dtag, &ds);
3930 strfree(name);
3931 if (error == ENOENT && ha->recursive)
3932 return (0);
3933 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3934 if (error)
3935 return (error);
3936
3937 ha->gotone = B_TRUE;
3938
3939 ASSERT(dsl_dataset_is_snapshot(ds));
3940
3941 error = dsl_dataset_release_might_destroy(ds, ha->htag, &might_destroy);
3942 if (error) {
3943 dsl_dataset_rele(ds, dtag);
3944 return (error);
3945 }
3946
3947 if (might_destroy) {
3948#ifdef _KERNEL
3949 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3950 error = zfs_unmount_snap(name, NULL);
3951 strfree(name);
3952 if (error) {
3953 dsl_dataset_rele(ds, dtag);
3954 return (error);
3955 }
3956#endif
3957 if (!dsl_dataset_tryown(ds, B_TRUE, dtag)) {
3958 dsl_dataset_rele(ds, dtag);
3959 return (EBUSY);
3960 } else {
3961 own = B_TRUE;
3962 dsl_dataset_make_exclusive(ds, dtag);
3963 }
3964 }
3965
3966 ra = kmem_alloc(sizeof (struct dsl_ds_releasearg), KM_SLEEP);
3967 ra->ds = ds;
3968 ra->htag = ha->htag;
3969 ra->own = own;
3970 dsl_sync_task_create(ha->dstg, dsl_dataset_user_release_check,
3971 dsl_dataset_user_release_sync, ra, dtag, 0);
3972
3973 return (0);
3974}
3975
3976int
3977dsl_dataset_user_release(char *dsname, char *snapname, char *htag,
3978 boolean_t recursive)
3979{
3980 struct dsl_ds_holdarg *ha;
3981 dsl_sync_task_t *dst;
3982 spa_t *spa;
3983 int error;
3984
3985top:
3986 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3987
3988 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3989
3990 error = spa_open(dsname, &spa, FTAG);
3991 if (error) {
3992 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3993 return (error);
3994 }
3995
3996 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
3997 ha->htag = htag;
3998 ha->snapname = snapname;
3999 ha->recursive = recursive;
4000 if (recursive) {
4001 error = dmu_objset_find(dsname, dsl_dataset_user_release_one,
4002 ha, DS_FIND_CHILDREN);
4003 } else {
4004 error = dsl_dataset_user_release_one(dsname, ha);
4005 }
4006 if (error == 0)
4007 error = dsl_sync_task_group_wait(ha->dstg);
4008
4009 for (dst = list_head(&ha->dstg->dstg_tasks); dst;
4010 dst = list_next(&ha->dstg->dstg_tasks, dst)) {
4011 struct dsl_ds_releasearg *ra = dst->dst_arg1;
4012 dsl_dataset_t *ds = ra->ds;
4013
4014 if (dst->dst_err)
4015 dsl_dataset_name(ds, ha->failed);
4016
4017 if (ra->own)
4018 dsl_dataset_disown(ds, ha->dstg);
4019 else
4020 dsl_dataset_rele(ds, ha->dstg);
4021
4022 kmem_free(ra, sizeof (struct dsl_ds_releasearg));
4023 }
4024
4025 if (error == 0 && recursive && !ha->gotone)
4026 error = ENOENT;
4027
4028 if (error && error != EBUSY)
4029 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed));
4030
4031 dsl_sync_task_group_destroy(ha->dstg);
4032 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
4033 spa_close(spa, FTAG);
4034
4035 /*
4036 * We can get EBUSY if we were racing with deferred destroy and
4037 * dsl_dataset_user_release_check() hadn't done the necessary
4038 * open context setup. We can also get EBUSY if we're racing
4039 * with destroy and that thread is the ds_owner. Either way
4040 * the busy condition should be transient, and we should retry
4041 * the release operation.
4042 */
4043 if (error == EBUSY)
4044 goto top;
4045
4046 return (error);
4047}
4048
4049/*
4050 * Called at spa_load time (with retry == B_FALSE) to release a stale
4051 * temporary user hold. Also called by the onexit code (with retry == B_TRUE).
4052 */
4053int
4054dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, char *htag,
4055 boolean_t retry)
4056{
4057 dsl_dataset_t *ds;
4058 char *snap;
4059 char *name;
4060 int namelen;
4061 int error;
4062
4063 do {
4064 rw_enter(&dp->dp_config_rwlock, RW_READER);
4065 error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds);
4066 rw_exit(&dp->dp_config_rwlock);
4067 if (error)
4068 return (error);
4069 namelen = dsl_dataset_namelen(ds)+1;
4070 name = kmem_alloc(namelen, KM_SLEEP);
4071 dsl_dataset_name(ds, name);
4072 dsl_dataset_rele(ds, FTAG);
4073
4074 snap = strchr(name, '@');
4075 *snap = '\0';
4076 ++snap;
4077 error = dsl_dataset_user_release(name, snap, htag, B_FALSE);
4078 kmem_free(name, namelen);
4079
4080 /*
4081 * The object can't have been destroyed because we have a hold,
4082 * but it might have been renamed, resulting in ENOENT. Retry
4083 * if we've been requested to do so.
4084 *
4085 * It would be nice if we could use the dsobj all the way
4086 * through and avoid ENOENT entirely. But we might need to
4087 * unmount the snapshot, and there's currently no way to lookup
4088 * a vfsp using a ZFS object id.
4089 */
4090 } while ((error == ENOENT) && retry);
4091
4092 return (error);
4093}
4094
4095int
4096dsl_dataset_get_holds(const char *dsname, nvlist_t **nvp)
4097{
4098 dsl_dataset_t *ds;
4099 int err;
4100
4101 err = dsl_dataset_hold(dsname, FTAG, &ds);
4102 if (err)
4103 return (err);
4104
4105 VERIFY(0 == nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP));
4106 if (ds->ds_phys->ds_userrefs_obj != 0) {
4107 zap_attribute_t *za;
4108 zap_cursor_t zc;
4109
4110 za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP);
4111 for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset,
4112 ds->ds_phys->ds_userrefs_obj);
4113 zap_cursor_retrieve(&zc, za) == 0;
4114 zap_cursor_advance(&zc)) {
4115 VERIFY(0 == nvlist_add_uint64(*nvp, za->za_name,
4116 za->za_first_integer));
4117 }
4118 zap_cursor_fini(&zc);
4119 kmem_free(za, sizeof (zap_attribute_t));
4120 }
4121 dsl_dataset_rele(ds, FTAG);
4122 return (0);
4123}
4124
4125/*
|
4028 * Note, this fuction is used as the callback for dmu_objset_find(). We
| 4126 * Note, this function is used as the callback for dmu_objset_find(). We
|
4029 * always return 0 so that we will continue to find and process
4030 * inconsistent datasets, even if we encounter an error trying to
4031 * process one of them.
4032 */
4033/* ARGSUSED */
4034int
4035dsl_destroy_inconsistent(const char *dsname, void *arg)
4036{
4037 dsl_dataset_t *ds;
4038
4039 if (dsl_dataset_own(dsname, B_TRUE, FTAG, &ds) == 0) {
4040 if (DS_IS_INCONSISTENT(ds))
4041 (void) dsl_dataset_destroy(ds, FTAG, B_FALSE);
4042 else
4043 dsl_dataset_disown(ds, FTAG);
4044 }
4045 return (0);
4046}
| 4127 * always return 0 so that we will continue to find and process
4128 * inconsistent datasets, even if we encounter an error trying to
4129 * process one of them.
4130 */
4131/* ARGSUSED */
4132int
4133dsl_destroy_inconsistent(const char *dsname, void *arg)
4134{
4135 dsl_dataset_t *ds;
4136
4137 if (dsl_dataset_own(dsname, B_TRUE, FTAG, &ds) == 0) {
4138 if (DS_IS_INCONSISTENT(ds))
4139 (void) dsl_dataset_destroy(ds, FTAG, B_FALSE);
4140 else
4141 dsl_dataset_disown(ds, FTAG);
4142 }
4143 return (0);
4144}
|
| 4145
4146/*
4147 * Return (in *usedp) the amount of space written in new that is not
4148 * present in oldsnap. New may be a snapshot or the head. Old must be
4149 * a snapshot before new, in new's filesystem (or its origin). If not then
4150 * fail and return EINVAL.
4151 *
4152 * The written space is calculated by considering two components: First, we
4153 * ignore any freed space, and calculate the written as new's used space
4154 * minus old's used space. Next, we add in the amount of space that was freed
4155 * between the two snapshots, thus reducing new's used space relative to old's.
4156 * Specifically, this is the space that was born before old->ds_creation_txg,
4157 * and freed before new (ie. on new's deadlist or a previous deadlist).
4158 *
4159 * space freed [---------------------]
4160 * snapshots ---O-------O--------O-------O------
4161 * oldsnap new
4162 */
4163int
4164dsl_dataset_space_written(dsl_dataset_t *oldsnap, dsl_dataset_t *new,
4165 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
4166{
4167 int err = 0;
4168 uint64_t snapobj;
4169 dsl_pool_t *dp = new->ds_dir->dd_pool;
4170
4171 *usedp = 0;
4172 *usedp += new->ds_phys->ds_used_bytes;
4173 *usedp -= oldsnap->ds_phys->ds_used_bytes;
4174
4175 *compp = 0;
4176 *compp += new->ds_phys->ds_compressed_bytes;
4177 *compp -= oldsnap->ds_phys->ds_compressed_bytes;
4178
4179 *uncompp = 0;
4180 *uncompp += new->ds_phys->ds_uncompressed_bytes;
4181 *uncompp -= oldsnap->ds_phys->ds_uncompressed_bytes;
4182
4183 rw_enter(&dp->dp_config_rwlock, RW_READER);
4184 snapobj = new->ds_object;
4185 while (snapobj != oldsnap->ds_object) {
4186 dsl_dataset_t *snap;
4187 uint64_t used, comp, uncomp;
4188
4189 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &snap);
4190 if (err != 0)
4191 break;
4192
4193 if (snap->ds_phys->ds_prev_snap_txg ==
4194 oldsnap->ds_phys->ds_creation_txg) {
4195 /*
4196 * The blocks in the deadlist can not be born after
4197 * ds_prev_snap_txg, so get the whole deadlist space,
4198 * which is more efficient (especially for old-format
4199 * deadlists). Unfortunately the deadlist code
4200 * doesn't have enough information to make this
4201 * optimization itself.
4202 */
4203 dsl_deadlist_space(&snap->ds_deadlist,
4204 &used, &comp, &uncomp);
4205 } else {
4206 dsl_deadlist_space_range(&snap->ds_deadlist,
4207 0, oldsnap->ds_phys->ds_creation_txg,
4208 &used, &comp, &uncomp);
4209 }
4210 *usedp += used;
4211 *compp += comp;
4212 *uncompp += uncomp;
4213
4214 /*
4215 * If we get to the beginning of the chain of snapshots
4216 * (ds_prev_snap_obj == 0) before oldsnap, then oldsnap
4217 * was not a snapshot of/before new.
4218 */
4219 snapobj = snap->ds_phys->ds_prev_snap_obj;
4220 dsl_dataset_rele(snap, FTAG);
4221 if (snapobj == 0) {
4222 err = EINVAL;
4223 break;
4224 }
4225
4226 }
4227 rw_exit(&dp->dp_config_rwlock);
4228 return (err);
4229}
4230
4231/*
4232 * Return (in *usedp) the amount of space that will be reclaimed if firstsnap,
4233 * lastsnap, and all snapshots in between are deleted.
4234 *
4235 * blocks that would be freed [---------------------------]
4236 * snapshots ---O-------O--------O-------O--------O
4237 * firstsnap lastsnap
4238 *
4239 * This is the set of blocks that were born after the snap before firstsnap,
4240 * (birth > firstsnap->prev_snap_txg) and died before the snap after the
4241 * last snap (ie, is on lastsnap->ds_next->ds_deadlist or an earlier deadlist).
4242 * We calculate this by iterating over the relevant deadlists (from the snap
4243 * after lastsnap, backward to the snap after firstsnap), summing up the
4244 * space on the deadlist that was born after the snap before firstsnap.
4245 */
4246int
4247dsl_dataset_space_wouldfree(dsl_dataset_t *firstsnap,
4248 dsl_dataset_t *lastsnap,
4249 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
4250{
4251 int err = 0;
4252 uint64_t snapobj;
4253 dsl_pool_t *dp = firstsnap->ds_dir->dd_pool;
4254
4255 ASSERT(dsl_dataset_is_snapshot(firstsnap));
4256 ASSERT(dsl_dataset_is_snapshot(lastsnap));
4257
4258 /*
4259 * Check that the snapshots are in the same dsl_dir, and firstsnap
4260 * is before lastsnap.
4261 */
4262 if (firstsnap->ds_dir != lastsnap->ds_dir ||
4263 firstsnap->ds_phys->ds_creation_txg >
4264 lastsnap->ds_phys->ds_creation_txg)
4265 return (EINVAL);
4266
4267 *usedp = *compp = *uncompp = 0;
4268
4269 rw_enter(&dp->dp_config_rwlock, RW_READER);
4270 snapobj = lastsnap->ds_phys->ds_next_snap_obj;
4271 while (snapobj != firstsnap->ds_object) {
4272 dsl_dataset_t *ds;
4273 uint64_t used, comp, uncomp;
4274
4275 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &ds);
4276 if (err != 0)
4277 break;
4278
4279 dsl_deadlist_space_range(&ds->ds_deadlist,
4280 firstsnap->ds_phys->ds_prev_snap_txg, UINT64_MAX,
4281 &used, &comp, &uncomp);
4282 *usedp += used;
4283 *compp += comp;
4284 *uncompp += uncomp;
4285
4286 snapobj = ds->ds_phys->ds_prev_snap_obj;
4287 ASSERT3U(snapobj, !=, 0);
4288 dsl_dataset_rele(ds, FTAG);
4289 }
4290 rw_exit(&dp->dp_config_rwlock);
4291 return (err);
4292}
|
| |