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