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