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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 2009 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26 #include <sys/dmu_objset.h>
27 #include <sys/dsl_dataset.h>
28 #include <sys/dsl_dir.h>
29 #include <sys/dsl_prop.h>
30 #include <sys/dsl_synctask.h>
31 #include <sys/dmu_traverse.h>
32 #include <sys/dmu_tx.h>
33 #include <sys/arc.h>
34 #include <sys/zio.h>
35 #include <sys/zap.h>
36 #include <sys/unique.h>
37 #include <sys/zfs_context.h>
38 #include <sys/zfs_ioctl.h>
39 #include <sys/spa.h>
40 #include <sys/zfs_znode.h>
41 #include <sys/sunddi.h>
42 #include <sys/zvol.h>
43
44 static char *dsl_reaper = "the grim reaper";
45
46 static dsl_checkfunc_t dsl_dataset_destroy_begin_check;
47 static dsl_syncfunc_t dsl_dataset_destroy_begin_sync;
48 static dsl_checkfunc_t dsl_dataset_rollback_check;
49 static dsl_syncfunc_t dsl_dataset_rollback_sync;
50 static dsl_syncfunc_t dsl_dataset_set_reservation_sync;
51
52 #define DS_REF_MAX (1ULL << 62)
53
54 #define DSL_DEADLIST_BLOCKSIZE SPA_MAXBLOCKSIZE
55
56 #define DSL_DATASET_IS_DESTROYED(ds) ((ds)->ds_owner == dsl_reaper)
57
58
59 /*
60 * Figure out how much of this delta should be propogated to the dsl_dir
61 * layer. If there's a refreservation, that space has already been
62 * partially accounted for in our ancestors.
63 */
64 static int64_t
65 parent_delta(dsl_dataset_t *ds, int64_t delta)
66 {
67 uint64_t old_bytes, new_bytes;
68
69 if (ds->ds_reserved == 0)
70 return (delta);
71
72 old_bytes = MAX(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
73 new_bytes = MAX(ds->ds_phys->ds_unique_bytes + delta, ds->ds_reserved);
74
75 ASSERT3U(ABS((int64_t)(new_bytes - old_bytes)), <=, ABS(delta));
76 return (new_bytes - old_bytes);
77 }
78
79 void
80 dsl_dataset_block_born(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx)
81 {
82 int used = bp_get_dasize(tx->tx_pool->dp_spa, bp);
83 int compressed = BP_GET_PSIZE(bp);
84 int uncompressed = BP_GET_UCSIZE(bp);
85 int64_t delta;
86
87 dprintf_bp(bp, "born, ds=%p\n", ds);
88
89 ASSERT(dmu_tx_is_syncing(tx));
90 /* It could have been compressed away to nothing */
91 if (BP_IS_HOLE(bp))
92 return;
93 ASSERT(BP_GET_TYPE(bp) != DMU_OT_NONE);
94 ASSERT3U(BP_GET_TYPE(bp), <, DMU_OT_NUMTYPES);
95 if (ds == NULL) {
96 /*
97 * Account for the meta-objset space in its placeholder
98 * dsl_dir.
99 */
100 ASSERT3U(compressed, ==, uncompressed); /* it's all metadata */
101 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD,
102 used, compressed, uncompressed, tx);
103 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx);
104 return;
105 }
106 dmu_buf_will_dirty(ds->ds_dbuf, tx);
107 mutex_enter(&ds->ds_dir->dd_lock);
108 mutex_enter(&ds->ds_lock);
109 delta = parent_delta(ds, used);
110 ds->ds_phys->ds_used_bytes += used;
111 ds->ds_phys->ds_compressed_bytes += compressed;
112 ds->ds_phys->ds_uncompressed_bytes += uncompressed;
113 ds->ds_phys->ds_unique_bytes += used;
114 mutex_exit(&ds->ds_lock);
115 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta,
116 compressed, uncompressed, tx);
117 dsl_dir_transfer_space(ds->ds_dir, used - delta,
118 DD_USED_REFRSRV, DD_USED_HEAD, tx);
119 mutex_exit(&ds->ds_dir->dd_lock);
120 }
121
122 int
123 dsl_dataset_block_kill(dsl_dataset_t *ds, blkptr_t *bp, zio_t *pio,
124 dmu_tx_t *tx)
125 {
126 int used = bp_get_dasize(tx->tx_pool->dp_spa, bp);
127 int compressed = BP_GET_PSIZE(bp);
128 int uncompressed = BP_GET_UCSIZE(bp);
129
130 ASSERT(pio != NULL);
131 ASSERT(dmu_tx_is_syncing(tx));
132 /* No block pointer => nothing to free */
133 if (BP_IS_HOLE(bp))
134 return (0);
135
136 ASSERT(used > 0);
137 if (ds == NULL) {
138 int err;
139 /*
140 * Account for the meta-objset space in its placeholder
141 * dataset.
142 */
143 err = dsl_free(pio, tx->tx_pool,
144 tx->tx_txg, bp, NULL, NULL, ARC_NOWAIT);
145 ASSERT(err == 0);
146
147 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD,
148 -used, -compressed, -uncompressed, tx);
149 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx);
150 return (used);
151 }
152 ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool);
153
154 ASSERT(!dsl_dataset_is_snapshot(ds));
155 dmu_buf_will_dirty(ds->ds_dbuf, tx);
156
157 if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) {
158 int err;
159 int64_t delta;
160
161 dprintf_bp(bp, "freeing: %s", "");
162 err = dsl_free(pio, tx->tx_pool,
163 tx->tx_txg, bp, NULL, NULL, ARC_NOWAIT);
164 ASSERT(err == 0);
165
166 mutex_enter(&ds->ds_dir->dd_lock);
167 mutex_enter(&ds->ds_lock);
168 ASSERT(ds->ds_phys->ds_unique_bytes >= used ||
169 !DS_UNIQUE_IS_ACCURATE(ds));
170 delta = parent_delta(ds, -used);
171 ds->ds_phys->ds_unique_bytes -= used;
172 mutex_exit(&ds->ds_lock);
173 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
174 delta, -compressed, -uncompressed, tx);
175 dsl_dir_transfer_space(ds->ds_dir, -used - delta,
176 DD_USED_REFRSRV, DD_USED_HEAD, tx);
177 mutex_exit(&ds->ds_dir->dd_lock);
178 } else {
179 dprintf_bp(bp, "putting on dead list: %s", "");
180 VERIFY(0 == bplist_enqueue(&ds->ds_deadlist, bp, tx));
181 ASSERT3U(ds->ds_prev->ds_object, ==,
182 ds->ds_phys->ds_prev_snap_obj);
183 ASSERT(ds->ds_prev->ds_phys->ds_num_children > 0);
184 /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */
185 if (ds->ds_prev->ds_phys->ds_next_snap_obj ==
186 ds->ds_object && bp->blk_birth >
187 ds->ds_prev->ds_phys->ds_prev_snap_txg) {
188 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
189 mutex_enter(&ds->ds_prev->ds_lock);
190 ds->ds_prev->ds_phys->ds_unique_bytes += used;
191 mutex_exit(&ds->ds_prev->ds_lock);
192 }
193 if (bp->blk_birth > ds->ds_origin_txg) {
194 dsl_dir_transfer_space(ds->ds_dir, used,
195 DD_USED_HEAD, DD_USED_SNAP, tx);
196 }
197 }
198 mutex_enter(&ds->ds_lock);
199 ASSERT3U(ds->ds_phys->ds_used_bytes, >=, used);
200 ds->ds_phys->ds_used_bytes -= used;
201 ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed);
202 ds->ds_phys->ds_compressed_bytes -= compressed;
203 ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed);
204 ds->ds_phys->ds_uncompressed_bytes -= uncompressed;
205 mutex_exit(&ds->ds_lock);
206
207 return (used);
208 }
209
210 uint64_t
211 dsl_dataset_prev_snap_txg(dsl_dataset_t *ds)
212 {
213 uint64_t trysnap = 0;
214
215 if (ds == NULL)
216 return (0);
217 /*
218 * The snapshot creation could fail, but that would cause an
219 * incorrect FALSE return, which would only result in an
220 * overestimation of the amount of space that an operation would
221 * consume, which is OK.
222 *
223 * There's also a small window where we could miss a pending
224 * snapshot, because we could set the sync task in the quiescing
225 * phase. So this should only be used as a guess.
226 */
227 if (ds->ds_trysnap_txg >
228 spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa))
229 trysnap = ds->ds_trysnap_txg;
230 return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap));
231 }
232
233 boolean_t
234 dsl_dataset_block_freeable(dsl_dataset_t *ds, uint64_t blk_birth)
235 {
236 return (blk_birth > dsl_dataset_prev_snap_txg(ds));
237 }
238
239 /* ARGSUSED */
240 static void
241 dsl_dataset_evict(dmu_buf_t *db, void *dsv)
242 {
243 dsl_dataset_t *ds = dsv;
244
245 ASSERT(ds->ds_owner == NULL || DSL_DATASET_IS_DESTROYED(ds));
246
247 dprintf_ds(ds, "evicting %s\n", "");
248
249 unique_remove(ds->ds_fsid_guid);
250
251 if (ds->ds_user_ptr != NULL)
252 ds->ds_user_evict_func(ds, ds->ds_user_ptr);
253
254 if (ds->ds_prev) {
255 dsl_dataset_drop_ref(ds->ds_prev, ds);
256 ds->ds_prev = NULL;
257 }
258
259 bplist_close(&ds->ds_deadlist);
260 if (ds->ds_dir)
261 dsl_dir_close(ds->ds_dir, ds);
262
263 ASSERT(!list_link_active(&ds->ds_synced_link));
264
265 mutex_destroy(&ds->ds_lock);
266 mutex_destroy(&ds->ds_recvlock);
267 mutex_destroy(&ds->ds_opening_lock);
268 mutex_destroy(&ds->ds_deadlist.bpl_lock);
269 rw_destroy(&ds->ds_rwlock);
270 cv_destroy(&ds->ds_exclusive_cv);
271
272 kmem_free(ds, sizeof (dsl_dataset_t));
273 }
274
275 static int
276 dsl_dataset_get_snapname(dsl_dataset_t *ds)
277 {
278 dsl_dataset_phys_t *headphys;
279 int err;
280 dmu_buf_t *headdbuf;
281 dsl_pool_t *dp = ds->ds_dir->dd_pool;
282 objset_t *mos = dp->dp_meta_objset;
283
284 if (ds->ds_snapname[0])
285 return (0);
286 if (ds->ds_phys->ds_next_snap_obj == 0)
287 return (0);
288
289 err = dmu_bonus_hold(mos, ds->ds_dir->dd_phys->dd_head_dataset_obj,
290 FTAG, &headdbuf);
291 if (err)
292 return (err);
293 headphys = headdbuf->db_data;
294 err = zap_value_search(dp->dp_meta_objset,
295 headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname);
296 dmu_buf_rele(headdbuf, FTAG);
297 return (err);
298 }
299
300 static int
301 dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name, uint64_t *value)
302 {
303 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
304 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
305 matchtype_t mt;
306 int err;
307
308 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
309 mt = MT_FIRST;
310 else
311 mt = MT_EXACT;
312
313 err = zap_lookup_norm(mos, snapobj, name, 8, 1,
314 value, mt, NULL, 0, NULL);
315 if (err == ENOTSUP && mt == MT_FIRST)
316 err = zap_lookup(mos, snapobj, name, 8, 1, value);
317 return (err);
318 }
319
320 static int
321 dsl_dataset_snap_remove(dsl_dataset_t *ds, char *name, dmu_tx_t *tx)
322 {
323 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
324 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
325 matchtype_t mt;
326 int err;
327
328 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
329 mt = MT_FIRST;
330 else
331 mt = MT_EXACT;
332
333 err = zap_remove_norm(mos, snapobj, name, mt, tx);
334 if (err == ENOTSUP && mt == MT_FIRST)
335 err = zap_remove(mos, snapobj, name, tx);
336 return (err);
337 }
338
339 static int
340 dsl_dataset_get_ref(dsl_pool_t *dp, uint64_t dsobj, void *tag,
341 dsl_dataset_t **dsp)
342 {
343 objset_t *mos = dp->dp_meta_objset;
344 dmu_buf_t *dbuf;
345 dsl_dataset_t *ds;
346 int err;
347
348 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) ||
349 dsl_pool_sync_context(dp));
350
351 err = dmu_bonus_hold(mos, dsobj, tag, &dbuf);
352 if (err)
353 return (err);
354 ds = dmu_buf_get_user(dbuf);
355 if (ds == NULL) {
356 dsl_dataset_t *winner;
357
358 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP);
359 ds->ds_dbuf = dbuf;
360 ds->ds_object = dsobj;
361 ds->ds_phys = dbuf->db_data;
362
363 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL);
364 mutex_init(&ds->ds_recvlock, NULL, MUTEX_DEFAULT, NULL);
365 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL);
366 mutex_init(&ds->ds_deadlist.bpl_lock, NULL, MUTEX_DEFAULT,
367 NULL);
368 rw_init(&ds->ds_rwlock, 0, 0, 0);
369 cv_init(&ds->ds_exclusive_cv, NULL, CV_DEFAULT, NULL);
370
371 err = bplist_open(&ds->ds_deadlist,
372 mos, ds->ds_phys->ds_deadlist_obj);
373 if (err == 0) {
374 err = dsl_dir_open_obj(dp,
375 ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir);
376 }
377 if (err) {
378 /*
379 * we don't really need to close the blist if we
380 * just opened it.
381 */
382 mutex_destroy(&ds->ds_lock);
383 mutex_destroy(&ds->ds_recvlock);
384 mutex_destroy(&ds->ds_opening_lock);
385 mutex_destroy(&ds->ds_deadlist.bpl_lock);
386 rw_destroy(&ds->ds_rwlock);
387 cv_destroy(&ds->ds_exclusive_cv);
388 kmem_free(ds, sizeof (dsl_dataset_t));
389 dmu_buf_rele(dbuf, tag);
390 return (err);
391 }
392
393 if (!dsl_dataset_is_snapshot(ds)) {
394 ds->ds_snapname[0] = '\0';
395 if (ds->ds_phys->ds_prev_snap_obj) {
396 err = dsl_dataset_get_ref(dp,
397 ds->ds_phys->ds_prev_snap_obj,
398 ds, &ds->ds_prev);
399 }
400
401 if (err == 0 && dsl_dir_is_clone(ds->ds_dir)) {
402 dsl_dataset_t *origin;
403
404 err = dsl_dataset_hold_obj(dp,
405 ds->ds_dir->dd_phys->dd_origin_obj,
406 FTAG, &origin);
407 if (err == 0) {
408 ds->ds_origin_txg =
409 origin->ds_phys->ds_creation_txg;
410 dsl_dataset_rele(origin, FTAG);
411 }
412 }
413 } else {
414 if (zfs_flags & ZFS_DEBUG_SNAPNAMES)
415 err = dsl_dataset_get_snapname(ds);
416 if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) {
417 err = zap_count(
418 ds->ds_dir->dd_pool->dp_meta_objset,
419 ds->ds_phys->ds_userrefs_obj,
420 &ds->ds_userrefs);
421 }
422 }
423
424 if (err == 0 && !dsl_dataset_is_snapshot(ds)) {
425 /*
426 * In sync context, we're called with either no lock
427 * or with the write lock. If we're not syncing,
428 * we're always called with the read lock held.
429 */
430 boolean_t need_lock =
431 !RW_WRITE_HELD(&dp->dp_config_rwlock) &&
432 dsl_pool_sync_context(dp);
433
434 if (need_lock)
435 rw_enter(&dp->dp_config_rwlock, RW_READER);
436
437 err = dsl_prop_get_ds(ds,
438 "refreservation", sizeof (uint64_t), 1,
439 &ds->ds_reserved, NULL);
440 if (err == 0) {
441 err = dsl_prop_get_ds(ds,
442 "refquota", sizeof (uint64_t), 1,
443 &ds->ds_quota, NULL);
444 }
445
446 if (need_lock)
447 rw_exit(&dp->dp_config_rwlock);
448 } else {
449 ds->ds_reserved = ds->ds_quota = 0;
450 }
451
452 if (err == 0) {
453 winner = dmu_buf_set_user_ie(dbuf, ds, &ds->ds_phys,
454 dsl_dataset_evict);
455 }
456 if (err || winner) {
457 bplist_close(&ds->ds_deadlist);
458 if (ds->ds_prev)
459 dsl_dataset_drop_ref(ds->ds_prev, ds);
460 dsl_dir_close(ds->ds_dir, ds);
461 mutex_destroy(&ds->ds_lock);
462 mutex_destroy(&ds->ds_recvlock);
463 mutex_destroy(&ds->ds_opening_lock);
464 mutex_destroy(&ds->ds_deadlist.bpl_lock);
465 rw_destroy(&ds->ds_rwlock);
466 cv_destroy(&ds->ds_exclusive_cv);
467 kmem_free(ds, sizeof (dsl_dataset_t));
468 if (err) {
469 dmu_buf_rele(dbuf, tag);
470 return (err);
471 }
472 ds = winner;
473 } else {
474 ds->ds_fsid_guid =
475 unique_insert(ds->ds_phys->ds_fsid_guid);
476 }
477 }
478 ASSERT3P(ds->ds_dbuf, ==, dbuf);
479 ASSERT3P(ds->ds_phys, ==, dbuf->db_data);
480 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 ||
481 spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN ||
482 dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap);
483 mutex_enter(&ds->ds_lock);
484 if (!dsl_pool_sync_context(dp) && DSL_DATASET_IS_DESTROYED(ds)) {
485 mutex_exit(&ds->ds_lock);
486 dmu_buf_rele(ds->ds_dbuf, tag);
487 return (ENOENT);
488 }
489 mutex_exit(&ds->ds_lock);
490 *dsp = ds;
491 return (0);
492 }
493
494 static int
495 dsl_dataset_hold_ref(dsl_dataset_t *ds, void *tag)
496 {
497 dsl_pool_t *dp = ds->ds_dir->dd_pool;
498
499 /*
500 * In syncing context we don't want the rwlock lock: there
501 * may be an existing writer waiting for sync phase to
502 * finish. We don't need to worry about such writers, since
503 * sync phase is single-threaded, so the writer can't be
504 * doing anything while we are active.
505 */
506 if (dsl_pool_sync_context(dp)) {
507 ASSERT(!DSL_DATASET_IS_DESTROYED(ds));
508 return (0);
509 }
510
511 /*
512 * Normal users will hold the ds_rwlock as a READER until they
513 * are finished (i.e., call dsl_dataset_rele()). "Owners" will
514 * drop their READER lock after they set the ds_owner field.
515 *
516 * If the dataset is being destroyed, the destroy thread will
517 * obtain a WRITER lock for exclusive access after it's done its
518 * open-context work and then change the ds_owner to
519 * dsl_reaper once destruction is assured. So threads
520 * may block here temporarily, until the "destructability" of
521 * the dataset is determined.
522 */
523 ASSERT(!RW_WRITE_HELD(&dp->dp_config_rwlock));
524 mutex_enter(&ds->ds_lock);
525 while (!rw_tryenter(&ds->ds_rwlock, RW_READER)) {
526 rw_exit(&dp->dp_config_rwlock);
527 cv_wait(&ds->ds_exclusive_cv, &ds->ds_lock);
528 if (DSL_DATASET_IS_DESTROYED(ds)) {
529 mutex_exit(&ds->ds_lock);
530 dsl_dataset_drop_ref(ds, tag);
531 rw_enter(&dp->dp_config_rwlock, RW_READER);
532 return (ENOENT);
533 }
534 rw_enter(&dp->dp_config_rwlock, RW_READER);
535 }
536 mutex_exit(&ds->ds_lock);
537 return (0);
538 }
539
540 int
541 dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag,
542 dsl_dataset_t **dsp)
543 {
544 int err = dsl_dataset_get_ref(dp, dsobj, tag, dsp);
545
546 if (err)
547 return (err);
548 return (dsl_dataset_hold_ref(*dsp, tag));
549 }
550
551 int
552 dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj, int flags, void *owner,
553 dsl_dataset_t **dsp)
554 {
555 int err = dsl_dataset_hold_obj(dp, dsobj, owner, dsp);
556
557 ASSERT(DS_MODE_TYPE(flags) != DS_MODE_USER);
558
559 if (err)
560 return (err);
561 if (!dsl_dataset_tryown(*dsp, DS_MODE_IS_INCONSISTENT(flags), owner)) {
562 dsl_dataset_rele(*dsp, owner);
563 *dsp = NULL;
564 return (EBUSY);
565 }
566 return (0);
567 }
568
569 int
570 dsl_dataset_hold(const char *name, void *tag, dsl_dataset_t **dsp)
571 {
572 dsl_dir_t *dd;
573 dsl_pool_t *dp;
574 const char *snapname;
575 uint64_t obj;
576 int err = 0;
577
578 err = dsl_dir_open_spa(NULL, name, FTAG, &dd, &snapname);
579 if (err)
580 return (err);
581
582 dp = dd->dd_pool;
583 obj = dd->dd_phys->dd_head_dataset_obj;
584 rw_enter(&dp->dp_config_rwlock, RW_READER);
585 if (obj)
586 err = dsl_dataset_get_ref(dp, obj, tag, dsp);
587 else
588 err = ENOENT;
589 if (err)
590 goto out;
591
592 err = dsl_dataset_hold_ref(*dsp, tag);
593
594 /* we may be looking for a snapshot */
595 if (err == 0 && snapname != NULL) {
596 dsl_dataset_t *ds = NULL;
597
598 if (*snapname++ != '@') {
599 dsl_dataset_rele(*dsp, tag);
600 err = ENOENT;
601 goto out;
602 }
603
604 dprintf("looking for snapshot '%s'\n", snapname);
605 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj);
606 if (err == 0)
607 err = dsl_dataset_get_ref(dp, obj, tag, &ds);
608 dsl_dataset_rele(*dsp, tag);
609
610 ASSERT3U((err == 0), ==, (ds != NULL));
611
612 if (ds) {
613 mutex_enter(&ds->ds_lock);
614 if (ds->ds_snapname[0] == 0)
615 (void) strlcpy(ds->ds_snapname, snapname,
616 sizeof (ds->ds_snapname));
617 mutex_exit(&ds->ds_lock);
618 err = dsl_dataset_hold_ref(ds, tag);
619 *dsp = err ? NULL : ds;
620 }
621 }
622 out:
623 rw_exit(&dp->dp_config_rwlock);
624 dsl_dir_close(dd, FTAG);
625 return (err);
626 }
627
628 int
629 dsl_dataset_own(const char *name, int flags, void *owner, dsl_dataset_t **dsp)
630 {
631 int err = dsl_dataset_hold(name, owner, dsp);
632 if (err)
633 return (err);
634 if ((*dsp)->ds_phys->ds_num_children > 0 &&
635 !DS_MODE_IS_READONLY(flags)) {
636 dsl_dataset_rele(*dsp, owner);
637 return (EROFS);
638 }
639 if (!dsl_dataset_tryown(*dsp, DS_MODE_IS_INCONSISTENT(flags), owner)) {
640 dsl_dataset_rele(*dsp, owner);
641 return (EBUSY);
642 }
643 return (0);
644 }
645
646 void
647 dsl_dataset_name(dsl_dataset_t *ds, char *name)
648 {
649 if (ds == NULL) {
650 (void) strcpy(name, "mos");
651 } else {
652 dsl_dir_name(ds->ds_dir, name);
653 VERIFY(0 == dsl_dataset_get_snapname(ds));
654 if (ds->ds_snapname[0]) {
655 (void) strcat(name, "@");
656 /*
657 * We use a "recursive" mutex so that we
658 * can call dprintf_ds() with ds_lock held.
659 */
660 if (!MUTEX_HELD(&ds->ds_lock)) {
661 mutex_enter(&ds->ds_lock);
662 (void) strcat(name, ds->ds_snapname);
663 mutex_exit(&ds->ds_lock);
664 } else {
665 (void) strcat(name, ds->ds_snapname);
666 }
667 }
668 }
669 }
670
671 static int
672 dsl_dataset_namelen(dsl_dataset_t *ds)
673 {
674 int result;
675
676 if (ds == NULL) {
677 result = 3; /* "mos" */
678 } else {
679 result = dsl_dir_namelen(ds->ds_dir);
680 VERIFY(0 == dsl_dataset_get_snapname(ds));
681 if (ds->ds_snapname[0]) {
682 ++result; /* adding one for the @-sign */
683 if (!MUTEX_HELD(&ds->ds_lock)) {
684 mutex_enter(&ds->ds_lock);
685 result += strlen(ds->ds_snapname);
686 mutex_exit(&ds->ds_lock);
687 } else {
688 result += strlen(ds->ds_snapname);
689 }
690 }
691 }
692
693 return (result);
694 }
695
696 void
697 dsl_dataset_drop_ref(dsl_dataset_t *ds, void *tag)
698 {
699 dmu_buf_rele(ds->ds_dbuf, tag);
700 }
701
702 void
703 dsl_dataset_rele(dsl_dataset_t *ds, void *tag)
704 {
705 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) {
706 rw_exit(&ds->ds_rwlock);
707 }
708 dsl_dataset_drop_ref(ds, tag);
709 }
710
711 void
712 dsl_dataset_disown(dsl_dataset_t *ds, void *owner)
713 {
714 ASSERT((ds->ds_owner == owner && ds->ds_dbuf) ||
715 (DSL_DATASET_IS_DESTROYED(ds) && ds->ds_dbuf == NULL));
716
717 mutex_enter(&ds->ds_lock);
718 ds->ds_owner = NULL;
719 if (RW_WRITE_HELD(&ds->ds_rwlock)) {
720 rw_exit(&ds->ds_rwlock);
721 cv_broadcast(&ds->ds_exclusive_cv);
722 }
723 mutex_exit(&ds->ds_lock);
724 if (ds->ds_dbuf)
725 dsl_dataset_drop_ref(ds, owner);
726 else
727 dsl_dataset_evict(ds->ds_dbuf, ds);
728 }
729
730 boolean_t
731 dsl_dataset_tryown(dsl_dataset_t *ds, boolean_t inconsistentok, void *owner)
732 {
733 boolean_t gotit = FALSE;
734
735 mutex_enter(&ds->ds_lock);
736 if (ds->ds_owner == NULL &&
737 (!DS_IS_INCONSISTENT(ds) || inconsistentok)) {
738 ds->ds_owner = owner;
739 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool))
740 rw_exit(&ds->ds_rwlock);
741 gotit = TRUE;
742 }
743 mutex_exit(&ds->ds_lock);
744 return (gotit);
745 }
746
747 void
748 dsl_dataset_make_exclusive(dsl_dataset_t *ds, void *owner)
749 {
750 ASSERT3P(owner, ==, ds->ds_owner);
751 if (!RW_WRITE_HELD(&ds->ds_rwlock))
752 rw_enter(&ds->ds_rwlock, RW_WRITER);
753 }
754
755 uint64_t
756 dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin,
757 uint64_t flags, dmu_tx_t *tx)
758 {
759 dsl_pool_t *dp = dd->dd_pool;
760 dmu_buf_t *dbuf;
761 dsl_dataset_phys_t *dsphys;
762 uint64_t dsobj;
763 objset_t *mos = dp->dp_meta_objset;
764
765 if (origin == NULL)
766 origin = dp->dp_origin_snap;
767
768 ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp);
769 ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0);
770 ASSERT(dmu_tx_is_syncing(tx));
771 ASSERT(dd->dd_phys->dd_head_dataset_obj == 0);
772
773 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
774 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
775 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
776 dmu_buf_will_dirty(dbuf, tx);
777 dsphys = dbuf->db_data;
778 bzero(dsphys, sizeof (dsl_dataset_phys_t));
779 dsphys->ds_dir_obj = dd->dd_object;
780 dsphys->ds_flags = flags;
781 dsphys->ds_fsid_guid = unique_create();
782 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
783 sizeof (dsphys->ds_guid));
784 dsphys->ds_snapnames_zapobj =
785 zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP,
786 DMU_OT_NONE, 0, tx);
787 dsphys->ds_creation_time = gethrestime_sec();
788 dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg;
789 dsphys->ds_deadlist_obj =
790 bplist_create(mos, DSL_DEADLIST_BLOCKSIZE, tx);
791
792 if (origin) {
793 dsphys->ds_prev_snap_obj = origin->ds_object;
794 dsphys->ds_prev_snap_txg =
795 origin->ds_phys->ds_creation_txg;
796 dsphys->ds_used_bytes =
797 origin->ds_phys->ds_used_bytes;
798 dsphys->ds_compressed_bytes =
799 origin->ds_phys->ds_compressed_bytes;
800 dsphys->ds_uncompressed_bytes =
801 origin->ds_phys->ds_uncompressed_bytes;
802 dsphys->ds_bp = origin->ds_phys->ds_bp;
803 dsphys->ds_flags |= origin->ds_phys->ds_flags;
804
805 dmu_buf_will_dirty(origin->ds_dbuf, tx);
806 origin->ds_phys->ds_num_children++;
807
808 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) {
809 if (origin->ds_phys->ds_next_clones_obj == 0) {
810 origin->ds_phys->ds_next_clones_obj =
811 zap_create(mos,
812 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx);
813 }
814 VERIFY(0 == zap_add_int(mos,
815 origin->ds_phys->ds_next_clones_obj,
816 dsobj, tx));
817 }
818
819 dmu_buf_will_dirty(dd->dd_dbuf, tx);
820 dd->dd_phys->dd_origin_obj = origin->ds_object;
821 }
822
823 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
824 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
825
826 dmu_buf_rele(dbuf, FTAG);
827
828 dmu_buf_will_dirty(dd->dd_dbuf, tx);
829 dd->dd_phys->dd_head_dataset_obj = dsobj;
830
831 return (dsobj);
832 }
833
834 uint64_t
835 dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname,
836 dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx)
837 {
838 dsl_pool_t *dp = pdd->dd_pool;
839 uint64_t dsobj, ddobj;
840 dsl_dir_t *dd;
841
842 ASSERT(lastname[0] != '@');
843
844 ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx);
845 VERIFY(0 == dsl_dir_open_obj(dp, ddobj, lastname, FTAG, &dd));
846
847 dsobj = dsl_dataset_create_sync_dd(dd, origin, flags, tx);
848
849 dsl_deleg_set_create_perms(dd, tx, cr);
850
851 dsl_dir_close(dd, FTAG);
852
853 return (dsobj);
854 }
855
856 struct destroyarg {
857 dsl_sync_task_group_t *dstg;
858 char *snapname;
859 char *failed;
860 boolean_t defer;
861 };
862
863 static int
864 dsl_snapshot_destroy_one(char *name, void *arg)
865 {
866 struct destroyarg *da = arg;
867 dsl_dataset_t *ds;
868 int err;
869 char *dsname;
870 size_t buflen;
871
872 /* alloc a buffer to hold name@snapname, plus the terminating NULL */
873 buflen = strlen(name) + strlen(da->snapname) + 2;
874 dsname = kmem_alloc(buflen, KM_SLEEP);
875 (void) snprintf(dsname, buflen, "%s@%s", name, da->snapname);
876 err = dsl_dataset_own(dsname, DS_MODE_READONLY | DS_MODE_INCONSISTENT,
877 da->dstg, &ds);
878 kmem_free(dsname, buflen);
879 if (err == 0) {
880 struct dsl_ds_destroyarg *dsda;
881
882 dsl_dataset_make_exclusive(ds, da->dstg);
883 if (ds->ds_user_ptr) {
884 ds->ds_user_evict_func(ds, ds->ds_user_ptr);
885 ds->ds_user_ptr = NULL;
886 }
887 dsda = kmem_zalloc(sizeof (struct dsl_ds_destroyarg), KM_SLEEP);
888 dsda->ds = ds;
889 dsda->defer = da->defer;
890 dsl_sync_task_create(da->dstg, dsl_dataset_destroy_check,
891 dsl_dataset_destroy_sync, dsda, da->dstg, 0);
892 } else if (err == ENOENT) {
893 err = 0;
894 } else {
895 (void) strcpy(da->failed, name);
896 }
897 return (err);
898 }
899
900 /*
901 * Destroy 'snapname' in all descendants of 'fsname'.
902 */
903 #pragma weak dmu_snapshots_destroy = dsl_snapshots_destroy
904 int
905 dsl_snapshots_destroy(char *fsname, char *snapname, boolean_t defer)
906 {
907 int err;
908 struct destroyarg da;
909 dsl_sync_task_t *dst;
910 spa_t *spa;
911
912 err = spa_open(fsname, &spa, FTAG);
913 if (err)
914 return (err);
915 da.dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
916 da.snapname = snapname;
917 da.failed = fsname;
918 da.defer = defer;
919
920 err = dmu_objset_find(fsname,
921 dsl_snapshot_destroy_one, &da, DS_FIND_CHILDREN);
922
923 if (err == 0)
924 err = dsl_sync_task_group_wait(da.dstg);
925
926 for (dst = list_head(&da.dstg->dstg_tasks); dst;
927 dst = list_next(&da.dstg->dstg_tasks, dst)) {
928 struct dsl_ds_destroyarg *dsda = dst->dst_arg1;
929 dsl_dataset_t *ds = dsda->ds;
930
931 /*
932 * Return the file system name that triggered the error
933 */
934 if (dst->dst_err) {
935 dsl_dataset_name(ds, fsname);
936 *strchr(fsname, '@') = '\0';
937 }
938 ASSERT3P(dsda->rm_origin, ==, NULL);
939 dsl_dataset_disown(ds, da.dstg);
940 kmem_free(dsda, sizeof (struct dsl_ds_destroyarg));
941 }
942
943 dsl_sync_task_group_destroy(da.dstg);
944 spa_close(spa, FTAG);
945 return (err);
946 }
947
948 static boolean_t
949 dsl_dataset_might_destroy_origin(dsl_dataset_t *ds)
950 {
951 boolean_t might_destroy = B_FALSE;
952
953 mutex_enter(&ds->ds_lock);
954 if (ds->ds_phys->ds_num_children == 2 && ds->ds_userrefs == 0 &&
955 DS_IS_DEFER_DESTROY(ds))
956 might_destroy = B_TRUE;
957 mutex_exit(&ds->ds_lock);
958
959 return (might_destroy);
960 }
961
962 #ifdef _KERNEL
963 static int
964 dsl_dataset_zvol_cleanup(dsl_dataset_t *ds, const char *name)
965 {
966 int error;
967 objset_t *os;
968
969 error = dmu_objset_open_ds(ds, DMU_OST_ANY, &os);
970 if (error)
971 return (error);
972
973 if (dmu_objset_type(os) == DMU_OST_ZVOL)
974 error = zvol_remove_minor(name);
975 dmu_objset_close(os);
976
977 return (error);
978 }
979 #endif
980
981 /*
982 * If we're removing a clone, and these three conditions are true:
983 * 1) the clone's origin has no other children
984 * 2) the clone's origin has no user references
985 * 3) the clone's origin has been marked for deferred destruction
986 * Then, prepare to remove the origin as part of this sync task group.
987 */
988 static int
989 dsl_dataset_origin_rm_prep(struct dsl_ds_destroyarg *dsda, void *tag)
990 {
991 dsl_dataset_t *ds = dsda->ds;
992 dsl_dataset_t *origin = ds->ds_prev;
993
994 if (dsl_dataset_might_destroy_origin(origin)) {
995 char *name;
996 int namelen;
997 int error;
998
999 namelen = dsl_dataset_namelen(origin) + 1;
1000 name = kmem_alloc(namelen, KM_SLEEP);
1001 dsl_dataset_name(origin, name);
1002 #ifdef _KERNEL
1003 error = zfs_unmount_snap(name, NULL);
1004 if (error) {
1005 kmem_free(name, namelen);
1006 return (error);
1007 }
1008 error = dsl_dataset_zvol_cleanup(origin, name);
1009 if (error) {
1010 kmem_free(name, namelen);
1011 return (error);
1012 }
1013 #endif
1014 error = dsl_dataset_own(name,
1015 DS_MODE_READONLY | DS_MODE_INCONSISTENT,
1016 tag, &origin);
1017 kmem_free(name, namelen);
1018 if (error)
1019 return (error);
1020 dsda->rm_origin = origin;
1021 dsl_dataset_make_exclusive(origin, tag);
1022 }
1023
1024 return (0);
1025 }
1026
1027 /*
1028 * ds must be opened as OWNER. On return (whether successful or not),
1029 * ds will be closed and caller can no longer dereference it.
1030 */
1031 int
1032 dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer)
1033 {
1034 int err;
1035 dsl_sync_task_group_t *dstg;
1036 objset_t *os;
1037 dsl_dir_t *dd;
1038 uint64_t obj;
1039 struct dsl_ds_destroyarg dsda = {0};
1040
1041 dsda.ds = ds;
1042
1043 if (dsl_dataset_is_snapshot(ds)) {
1044 /* Destroying a snapshot is simpler */
1045 dsl_dataset_make_exclusive(ds, tag);
1046
1047 if (ds->ds_user_ptr) {
1048 ds->ds_user_evict_func(ds, ds->ds_user_ptr);
1049 ds->ds_user_ptr = NULL;
1050 }
1051 /* NOTE: defer is always B_FALSE for non-snapshots */
1052 dsda.defer = defer;
1053 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
1054 dsl_dataset_destroy_check, dsl_dataset_destroy_sync,
1055 &dsda, tag, 0);
1056 ASSERT3P(dsda.rm_origin, ==, NULL);
1057 goto out;
1058 }
1059
1060 dd = ds->ds_dir;
1061
1062 /*
1063 * Check for errors and mark this ds as inconsistent, in
1064 * case we crash while freeing the objects.
1065 */
1066 err = dsl_sync_task_do(dd->dd_pool, dsl_dataset_destroy_begin_check,
1067 dsl_dataset_destroy_begin_sync, ds, NULL, 0);
1068 if (err)
1069 goto out;
1070
1071 err = dmu_objset_open_ds(ds, DMU_OST_ANY, &os);
1072 if (err)
1073 goto out;
1074
1075 /*
1076 * remove the objects in open context, so that we won't
1077 * have too much to do in syncing context.
1078 */
1079 for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE,
1080 ds->ds_phys->ds_prev_snap_txg)) {
1081 /*
1082 * Ignore errors, if there is not enough disk space
1083 * we will deal with it in dsl_dataset_destroy_sync().
1084 */
1085 (void) dmu_free_object(os, obj);
1086 }
1087
1088 /*
1089 * We need to sync out all in-flight IO before we try to evict
1090 * (the dataset evict func is trying to clear the cached entries
1091 * for this dataset in the ARC).
1092 */
1093 txg_wait_synced(dd->dd_pool, 0);
1094
1095 /*
1096 * If we managed to free all the objects in open
1097 * context, the user space accounting should be zero.
1098 */
1099 if (ds->ds_phys->ds_bp.blk_fill == 0 &&
1100 dmu_objset_userused_enabled(os->os)) {
1101 uint64_t count;
1102
1103 ASSERT(zap_count(os, DMU_USERUSED_OBJECT, &count) != 0 ||
1104 count == 0);
1105 ASSERT(zap_count(os, DMU_GROUPUSED_OBJECT, &count) != 0 ||
1106 count == 0);
1107 }
1108
1109 dmu_objset_close(os);
1110 if (err != ESRCH)
1111 goto out;
1112
1113 rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
1114 err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd);
1115 rw_exit(&dd->dd_pool->dp_config_rwlock);
1116
1117 if (err)
1118 goto out;
1119
1120 if (ds->ds_user_ptr) {
1121 /*
1122 * We need to sync out all in-flight IO before we try
1123 * to evict (the dataset evict func is trying to clear
1124 * the cached entries for this dataset in the ARC).
1125 */
1126 txg_wait_synced(dd->dd_pool, 0);
1127 }
1128
1129 /*
1130 * Blow away the dsl_dir + head dataset.
1131 */
1132 dsl_dataset_make_exclusive(ds, tag);
1133 if (ds->ds_user_ptr) {
1134 ds->ds_user_evict_func(ds, ds->ds_user_ptr);
1135 ds->ds_user_ptr = NULL;
1136 }
1137
1138 /*
1139 * If we're removing a clone, we might also need to remove its
1140 * origin.
1141 */
1142 do {
1143 dsda.need_prep = B_FALSE;
1144 if (dsl_dir_is_clone(dd)) {
1145 err = dsl_dataset_origin_rm_prep(&dsda, tag);
1146 if (err) {
1147 dsl_dir_close(dd, FTAG);
1148 goto out;
1149 }
1150 }
1151
1152 dstg = dsl_sync_task_group_create(ds->ds_dir->dd_pool);
1153 dsl_sync_task_create(dstg, dsl_dataset_destroy_check,
1154 dsl_dataset_destroy_sync, &dsda, tag, 0);
1155 dsl_sync_task_create(dstg, dsl_dir_destroy_check,
1156 dsl_dir_destroy_sync, dd, FTAG, 0);
1157 err = dsl_sync_task_group_wait(dstg);
1158 dsl_sync_task_group_destroy(dstg);
1159
1160 /*
1161 * We could be racing against 'zfs release' or 'zfs destroy -d'
1162 * on the origin snap, in which case we can get EBUSY if we
1163 * needed to destroy the origin snap but were not ready to
1164 * do so.
1165 */
1166 if (dsda.need_prep) {
1167 ASSERT(err == EBUSY);
1168 ASSERT(dsl_dir_is_clone(dd));
1169 ASSERT(dsda.rm_origin == NULL);
1170 }
1171 } while (dsda.need_prep);
1172
1173 if (dsda.rm_origin != NULL)
1174 dsl_dataset_disown(dsda.rm_origin, tag);
1175
1176 /* if it is successful, dsl_dir_destroy_sync will close the dd */
1177 if (err)
1178 dsl_dir_close(dd, FTAG);
1179 out:
1180 dsl_dataset_disown(ds, tag);
1181 return (err);
1182 }
1183
1184 int
1185 dsl_dataset_rollback(dsl_dataset_t *ds, dmu_objset_type_t ost)
1186 {
1187 int err;
1188
1189 ASSERT(ds->ds_owner);
1190
1191 dsl_dataset_make_exclusive(ds, ds->ds_owner);
1192 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
1193 dsl_dataset_rollback_check, dsl_dataset_rollback_sync,
1194 ds, &ost, 0);
1195 /* drop exclusive access */
1196 mutex_enter(&ds->ds_lock);
1197 rw_exit(&ds->ds_rwlock);
1198 cv_broadcast(&ds->ds_exclusive_cv);
1199 mutex_exit(&ds->ds_lock);
1200 return (err);
1201 }
1202
1203 void *
1204 dsl_dataset_set_user_ptr(dsl_dataset_t *ds,
1205 void *p, dsl_dataset_evict_func_t func)
1206 {
1207 void *old;
1208
1209 mutex_enter(&ds->ds_lock);
1210 old = ds->ds_user_ptr;
1211 if (old == NULL) {
1212 ds->ds_user_ptr = p;
1213 ds->ds_user_evict_func = func;
1214 }
1215 mutex_exit(&ds->ds_lock);
1216 return (old);
1217 }
1218
1219 void *
1220 dsl_dataset_get_user_ptr(dsl_dataset_t *ds)
1221 {
1222 return (ds->ds_user_ptr);
1223 }
1224
1225 blkptr_t *
1226 dsl_dataset_get_blkptr(dsl_dataset_t *ds)
1227 {
1228 return (&ds->ds_phys->ds_bp);
1229 }
1230
1231 void
1232 dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx)
1233 {
1234 ASSERT(dmu_tx_is_syncing(tx));
1235 /* If it's the meta-objset, set dp_meta_rootbp */
1236 if (ds == NULL) {
1237 tx->tx_pool->dp_meta_rootbp = *bp;
1238 } else {
1239 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1240 ds->ds_phys->ds_bp = *bp;
1241 }
1242 }
1243
1244 spa_t *
1245 dsl_dataset_get_spa(dsl_dataset_t *ds)
1246 {
1247 return (ds->ds_dir->dd_pool->dp_spa);
1248 }
1249
1250 void
1251 dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx)
1252 {
1253 dsl_pool_t *dp;
1254
1255 if (ds == NULL) /* this is the meta-objset */
1256 return;
1257
1258 ASSERT(ds->ds_user_ptr != NULL);
1259
1260 if (ds->ds_phys->ds_next_snap_obj != 0)
1261 panic("dirtying snapshot!");
1262
1263 dp = ds->ds_dir->dd_pool;
1264
1265 if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg) == 0) {
1266 /* up the hold count until we can be written out */
1267 dmu_buf_add_ref(ds->ds_dbuf, ds);
1268 }
1269 }
1270
1271 /*
1272 * The unique space in the head dataset can be calculated by subtracting
1273 * the space used in the most recent snapshot, that is still being used
1274 * in this file system, from the space currently in use. To figure out
1275 * the space in the most recent snapshot still in use, we need to take
1276 * the total space used in the snapshot and subtract out the space that
1277 * has been freed up since the snapshot was taken.
1278 */
1279 static void
1280 dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds)
1281 {
1282 uint64_t mrs_used;
1283 uint64_t dlused, dlcomp, dluncomp;
1284
1285 ASSERT(ds->ds_object == ds->ds_dir->dd_phys->dd_head_dataset_obj);
1286
1287 if (ds->ds_phys->ds_prev_snap_obj != 0)
1288 mrs_used = ds->ds_prev->ds_phys->ds_used_bytes;
1289 else
1290 mrs_used = 0;
1291
1292 VERIFY(0 == bplist_space(&ds->ds_deadlist, &dlused, &dlcomp,
1293 &dluncomp));
1294
1295 ASSERT3U(dlused, <=, mrs_used);
1296 ds->ds_phys->ds_unique_bytes =
1297 ds->ds_phys->ds_used_bytes - (mrs_used - dlused);
1298
1299 if (!DS_UNIQUE_IS_ACCURATE(ds) &&
1300 spa_version(ds->ds_dir->dd_pool->dp_spa) >=
1301 SPA_VERSION_UNIQUE_ACCURATE)
1302 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
1303 }
1304
1305 static uint64_t
1306 dsl_dataset_unique(dsl_dataset_t *ds)
1307 {
1308 if (!DS_UNIQUE_IS_ACCURATE(ds) && !dsl_dataset_is_snapshot(ds))
1309 dsl_dataset_recalc_head_uniq(ds);
1310
1311 return (ds->ds_phys->ds_unique_bytes);
1312 }
1313
1314 struct killarg {
1315 dsl_dataset_t *ds;
1316 zio_t *zio;
1317 dmu_tx_t *tx;
1318 };
1319
1320 /* ARGSUSED */
1321 static int
1322 kill_blkptr(spa_t *spa, blkptr_t *bp, const zbookmark_t *zb,
1323 const dnode_phys_t *dnp, void *arg)
1324 {
1325 struct killarg *ka = arg;
1326
1327 if (bp == NULL)
1328 return (0);
1329
1330 if ((zb->zb_level == -1ULL && zb->zb_blkid != 0) ||
1331 (zb->zb_object != 0 && dnp == NULL)) {
1332 /*
1333 * It's a block in the intent log. It has no
1334 * accounting, so just free it.
1335 */
1336 VERIFY3U(0, ==, dsl_free(ka->zio, ka->tx->tx_pool,
1337 ka->tx->tx_txg, bp, NULL, NULL, ARC_NOWAIT));
1338 } else {
1339 ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg);
1340 (void) dsl_dataset_block_kill(ka->ds, bp, ka->zio, ka->tx);
1341 }
1342
1343 return (0);
1344 }
1345
1346 /* ARGSUSED */
1347 static int
1348 dsl_dataset_rollback_check(void *arg1, void *arg2, dmu_tx_t *tx)
1349 {
1350 dsl_dataset_t *ds = arg1;
1351 dmu_objset_type_t *ost = arg2;
1352
1353 /*
1354 * We can only roll back to emptyness if it is a ZPL objset.
1355 */
1356 if (*ost != DMU_OST_ZFS &&
1357 ds->ds_phys->ds_prev_snap_txg < TXG_INITIAL)
1358 return (EINVAL);
1359
1360 /*
1361 * This must not be a snapshot.
1362 */
1363 if (ds->ds_phys->ds_next_snap_obj != 0)
1364 return (EINVAL);
1365
1366 /*
1367 * If we made changes this txg, traverse_dataset won't find
1368 * them. Try again.
1369 */
1370 if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg)
1371 return (EAGAIN);
1372
1373 return (0);
1374 }
1375
1376 /* ARGSUSED */
1377 static void
1378 dsl_dataset_rollback_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
1379 {
1380 dsl_dataset_t *ds = arg1;
1381 dmu_objset_type_t *ost = arg2;
1382 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1383
1384 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1385
1386 if (ds->ds_user_ptr != NULL) {
1387 /*
1388 * We need to make sure that the objset_impl_t is reopened after
1389 * we do the rollback, otherwise it will have the wrong
1390 * objset_phys_t. Normally this would happen when this
1391 * dataset-open is closed, thus causing the
1392 * dataset to be immediately evicted. But when doing "zfs recv
1393 * -F", we reopen the objset before that, so that there is no
1394 * window where the dataset is closed and inconsistent.
1395 */
1396 ds->ds_user_evict_func(ds, ds->ds_user_ptr);
1397 ds->ds_user_ptr = NULL;
1398 }
1399
1400 /* Transfer space that was freed since last snap back to the head. */
1401 {
1402 uint64_t used;
1403
1404 VERIFY(0 == bplist_space_birthrange(&ds->ds_deadlist,
1405 ds->ds_origin_txg, UINT64_MAX, &used));
1406 dsl_dir_transfer_space(ds->ds_dir, used,
1407 DD_USED_SNAP, DD_USED_HEAD, tx);
1408 }
1409
1410 /* Zero out the deadlist. */
1411 bplist_close(&ds->ds_deadlist);
1412 bplist_destroy(mos, ds->ds_phys->ds_deadlist_obj, tx);
1413 ds->ds_phys->ds_deadlist_obj =
1414 bplist_create(mos, DSL_DEADLIST_BLOCKSIZE, tx);
1415 VERIFY(0 == bplist_open(&ds->ds_deadlist, mos,
1416 ds->ds_phys->ds_deadlist_obj));
1417
1418 {
1419 /*
1420 * Free blkptrs that we gave birth to - this covers
1421 * claimed but not played log blocks too.
1422 */
1423 zio_t *zio;
1424 struct killarg ka;
1425
1426 zio = zio_root(tx->tx_pool->dp_spa, NULL, NULL,
1427 ZIO_FLAG_MUSTSUCCEED);
1428 ka.ds = ds;
1429 ka.zio = zio;
1430 ka.tx = tx;
1431 (void) traverse_dataset(ds, ds->ds_phys->ds_prev_snap_txg,
1432 TRAVERSE_POST, kill_blkptr, &ka);
1433 (void) zio_wait(zio);
1434 }
1435
1436 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || ds->ds_phys->ds_unique_bytes == 0);
1437
1438 if (ds->ds_prev && ds->ds_prev != ds->ds_dir->dd_pool->dp_origin_snap) {
1439 /* Change our contents to that of the prev snapshot */
1440
1441 ASSERT3U(ds->ds_prev->ds_object, ==,
1442 ds->ds_phys->ds_prev_snap_obj);
1443 ASSERT3U(ds->ds_phys->ds_used_bytes, <=,
1444 ds->ds_prev->ds_phys->ds_used_bytes);
1445
1446 ds->ds_phys->ds_bp = ds->ds_prev->ds_phys->ds_bp;
1447 ds->ds_phys->ds_used_bytes =
1448 ds->ds_prev->ds_phys->ds_used_bytes;
1449 ds->ds_phys->ds_compressed_bytes =
1450 ds->ds_prev->ds_phys->ds_compressed_bytes;
1451 ds->ds_phys->ds_uncompressed_bytes =
1452 ds->ds_prev->ds_phys->ds_uncompressed_bytes;
1453 ds->ds_phys->ds_flags = ds->ds_prev->ds_phys->ds_flags;
1454
1455 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) {
1456 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
1457 ds->ds_prev->ds_phys->ds_unique_bytes = 0;
1458 }
1459 } else {
1460 objset_impl_t *osi;
1461
1462 ASSERT(*ost != DMU_OST_ZVOL);
1463 ASSERT3U(ds->ds_phys->ds_used_bytes, ==, 0);
1464 ASSERT3U(ds->ds_phys->ds_compressed_bytes, ==, 0);
1465 ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, ==, 0);
1466
1467 bzero(&ds->ds_phys->ds_bp, sizeof (blkptr_t));
1468 ds->ds_phys->ds_flags = 0;
1469 ds->ds_phys->ds_unique_bytes = 0;
1470 if (spa_version(ds->ds_dir->dd_pool->dp_spa) >=
1471 SPA_VERSION_UNIQUE_ACCURATE)
1472 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
1473
1474 osi = dmu_objset_create_impl(ds->ds_dir->dd_pool->dp_spa, ds,
1475 &ds->ds_phys->ds_bp, *ost, tx);
1476 #ifdef _KERNEL
1477 zfs_create_fs(&osi->os, kcred, NULL, tx);
1478 #endif
1479 }
1480
1481 spa_history_internal_log(LOG_DS_ROLLBACK, ds->ds_dir->dd_pool->dp_spa,
1482 tx, cr, "dataset = %llu", ds->ds_object);
1483 }
1484
1485 /* ARGSUSED */
1486 static int
1487 dsl_dataset_destroy_begin_check(void *arg1, void *arg2, dmu_tx_t *tx)
1488 {
1489 dsl_dataset_t *ds = arg1;
1490 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1491 uint64_t count;
1492 int err;
1493
1494 /*
1495 * Can't delete a head dataset if there are snapshots of it.
1496 * (Except if the only snapshots are from the branch we cloned
1497 * from.)
1498 */
1499 if (ds->ds_prev != NULL &&
1500 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object)
1501 return (EINVAL);
1502
1503 /*
1504 * This is really a dsl_dir thing, but check it here so that
1505 * we'll be less likely to leave this dataset inconsistent &
1506 * nearly destroyed.
1507 */
1508 err = zap_count(mos, ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count);
1509 if (err)
1510 return (err);
1511 if (count != 0)
1512 return (EEXIST);
1513
1514 return (0);
1515 }
1516
1517 /* ARGSUSED */
1518 static void
1519 dsl_dataset_destroy_begin_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
1520 {
1521 dsl_dataset_t *ds = arg1;
1522 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1523
1524 /* Mark it as inconsistent on-disk, in case we crash */
1525 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1526 ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT;
1527
1528 spa_history_internal_log(LOG_DS_DESTROY_BEGIN, dp->dp_spa, tx,
1529 cr, "dataset = %llu", ds->ds_object);
1530 }
1531
1532 static int
1533 dsl_dataset_origin_check(struct dsl_ds_destroyarg *dsda, void *tag,
1534 dmu_tx_t *tx)
1535 {
1536 dsl_dataset_t *ds = dsda->ds;
1537 dsl_dataset_t *ds_prev = ds->ds_prev;
1538
1539 if (dsl_dataset_might_destroy_origin(ds_prev)) {
1540 struct dsl_ds_destroyarg ndsda = {0};
1541
1542 /*
1543 * If we're not prepared to remove the origin, don't remove
1544 * the clone either.
1545 */
1546 if (dsda->rm_origin == NULL) {
1547 dsda->need_prep = B_TRUE;
1548 return (EBUSY);
1549 }
1550
1551 ndsda.ds = ds_prev;
1552 ndsda.is_origin_rm = B_TRUE;
1553 return (dsl_dataset_destroy_check(&ndsda, tag, tx));
1554 }
1555
1556 /*
1557 * If we're not going to remove the origin after all,
1558 * undo the open context setup.
1559 */
1560 if (dsda->rm_origin != NULL) {
1561 dsl_dataset_disown(dsda->rm_origin, tag);
1562 dsda->rm_origin = NULL;
1563 }
1564
1565 return (0);
1566 }
1567
1568 /* ARGSUSED */
1569 int
1570 dsl_dataset_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx)
1571 {
1572 struct dsl_ds_destroyarg *dsda = arg1;
1573 dsl_dataset_t *ds = dsda->ds;
1574
1575 /* we have an owner hold, so noone else can destroy us */
1576 ASSERT(!DSL_DATASET_IS_DESTROYED(ds));
1577
1578 /*
1579 * Only allow deferred destroy on pools that support it.
1580 * NOTE: deferred destroy is only supported on snapshots.
1581 */
1582 if (dsda->defer) {
1583 if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
1584 SPA_VERSION_USERREFS)
1585 return (ENOTSUP);
1586 ASSERT(dsl_dataset_is_snapshot(ds));
1587 return (0);
1588 }
1589
1590 /*
1591 * Can't delete a head dataset if there are snapshots of it.
1592 * (Except if the only snapshots are from the branch we cloned
1593 * from.)
1594 */
1595 if (ds->ds_prev != NULL &&
1596 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object)
1597 return (EINVAL);
1598
1599 /*
1600 * If we made changes this txg, traverse_dsl_dataset won't find
1601 * them. Try again.
1602 */
1603 if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg)
1604 return (EAGAIN);
1605
1606 if (dsl_dataset_is_snapshot(ds)) {
1607 /*
1608 * If this snapshot has an elevated user reference count,
1609 * we can't destroy it yet.
1610 */
1611 if (ds->ds_userrefs > 0 && !dsda->releasing)
1612 return (EBUSY);
1613
1614 mutex_enter(&ds->ds_lock);
1615 /*
1616 * Can't delete a branch point. However, if we're destroying
1617 * a clone and removing its origin due to it having a user
1618 * hold count of 0 and having been marked for deferred destroy,
1619 * it's OK for the origin to have a single clone.
1620 */
1621 if (ds->ds_phys->ds_num_children >
1622 (dsda->is_origin_rm ? 2 : 1)) {
1623 mutex_exit(&ds->ds_lock);
1624 return (EEXIST);
1625 }
1626 mutex_exit(&ds->ds_lock);
1627 } else if (dsl_dir_is_clone(ds->ds_dir)) {
1628 return (dsl_dataset_origin_check(dsda, arg2, tx));
1629 }
1630
1631 /* XXX we should do some i/o error checking... */
1632 return (0);
1633 }
1634
1635 struct refsarg {
1636 kmutex_t lock;
1637 boolean_t gone;
1638 kcondvar_t cv;
1639 };
1640
1641 /* ARGSUSED */
1642 static void
1643 dsl_dataset_refs_gone(dmu_buf_t *db, void *argv)
1644 {
1645 struct refsarg *arg = argv;
1646
1647 mutex_enter(&arg->lock);
1648 arg->gone = TRUE;
1649 cv_signal(&arg->cv);
1650 mutex_exit(&arg->lock);
1651 }
1652
1653 static void
1654 dsl_dataset_drain_refs(dsl_dataset_t *ds, void *tag)
1655 {
1656 struct refsarg arg;
1657
1658 mutex_init(&arg.lock, NULL, MUTEX_DEFAULT, NULL);
1659 cv_init(&arg.cv, NULL, CV_DEFAULT, NULL);
1660 arg.gone = FALSE;
1661 (void) dmu_buf_update_user(ds->ds_dbuf, ds, &arg, &ds->ds_phys,
1662 dsl_dataset_refs_gone);
1663 dmu_buf_rele(ds->ds_dbuf, tag);
1664 mutex_enter(&arg.lock);
1665 while (!arg.gone)
1666 cv_wait(&arg.cv, &arg.lock);
1667 ASSERT(arg.gone);
1668 mutex_exit(&arg.lock);
1669 ds->ds_dbuf = NULL;
1670 ds->ds_phys = NULL;
1671 mutex_destroy(&arg.lock);
1672 cv_destroy(&arg.cv);
1673 }
1674
1675 void
1676 dsl_dataset_destroy_sync(void *arg1, void *tag, cred_t *cr, dmu_tx_t *tx)
1677 {
1678 struct dsl_ds_destroyarg *dsda = arg1;
1679 dsl_dataset_t *ds = dsda->ds;
1680 zio_t *zio;
1681 int err;
1682 int after_branch_point = FALSE;
1683 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1684 objset_t *mos = dp->dp_meta_objset;
1685 dsl_dataset_t *ds_prev = NULL;
1686 uint64_t obj;
1687
1688 ASSERT(ds->ds_owner);
1689 ASSERT(dsda->defer || ds->ds_phys->ds_num_children <= 1);
1690 ASSERT(ds->ds_prev == NULL ||
1691 ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object);
1692 ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg);
1693
1694 if (dsda->defer) {
1695 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
1696 if (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1) {
1697 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1698 ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY;
1699 return;
1700 }
1701 }
1702
1703 /* signal any waiters that this dataset is going away */
1704 mutex_enter(&ds->ds_lock);
1705 ds->ds_owner = dsl_reaper;
1706 cv_broadcast(&ds->ds_exclusive_cv);
1707 mutex_exit(&ds->ds_lock);
1708
1709 /* Remove our reservation */
1710 if (ds->ds_reserved != 0) {
1711 uint64_t val = 0;
1712 dsl_dataset_set_reservation_sync(ds, &val, cr, tx);
1713 ASSERT3U(ds->ds_reserved, ==, 0);
1714 }
1715
1716 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
1717
1718 dsl_pool_ds_destroyed(ds, tx);
1719
1720 obj = ds->ds_object;
1721
1722 if (ds->ds_phys->ds_prev_snap_obj != 0) {
1723 if (ds->ds_prev) {
1724 ds_prev = ds->ds_prev;
1725 } else {
1726 VERIFY(0 == dsl_dataset_hold_obj(dp,
1727 ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev));
1728 }
1729 after_branch_point =
1730 (ds_prev->ds_phys->ds_next_snap_obj != obj);
1731
1732 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx);
1733 if (after_branch_point &&
1734 ds_prev->ds_phys->ds_next_clones_obj != 0) {
1735 VERIFY3U(0, ==, zap_remove_int(mos,
1736 ds_prev->ds_phys->ds_next_clones_obj, obj, tx));
1737 if (ds->ds_phys->ds_next_snap_obj != 0) {
1738 VERIFY(0 == zap_add_int(mos,
1739 ds_prev->ds_phys->ds_next_clones_obj,
1740 ds->ds_phys->ds_next_snap_obj, tx));
1741 }
1742 }
1743 if (after_branch_point &&
1744 ds->ds_phys->ds_next_snap_obj == 0) {
1745 /* This clone is toast. */
1746 ASSERT(ds_prev->ds_phys->ds_num_children > 1);
1747 ds_prev->ds_phys->ds_num_children--;
1748
1749 /*
1750 * If the clone's origin has no other clones, no
1751 * user holds, and has been marked for deferred
1752 * deletion, then we should have done the necessary
1753 * destroy setup for it.
1754 */
1755 if (ds_prev->ds_phys->ds_num_children == 1 &&
1756 ds_prev->ds_userrefs == 0 &&
1757 DS_IS_DEFER_DESTROY(ds_prev)) {
1758 ASSERT3P(dsda->rm_origin, !=, NULL);
1759 } else {
1760 ASSERT3P(dsda->rm_origin, ==, NULL);
1761 }
1762 } else if (!after_branch_point) {
1763 ds_prev->ds_phys->ds_next_snap_obj =
1764 ds->ds_phys->ds_next_snap_obj;
1765 }
1766 }
1767
1768 zio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
1769
1770 if (ds->ds_phys->ds_next_snap_obj != 0) {
1771 blkptr_t bp;
1772 dsl_dataset_t *ds_next;
1773 uint64_t itor = 0;
1774 uint64_t old_unique;
1775 int64_t used = 0, compressed = 0, uncompressed = 0;
1776
1777 VERIFY(0 == dsl_dataset_hold_obj(dp,
1778 ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next));
1779 ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj);
1780
1781 old_unique = dsl_dataset_unique(ds_next);
1782
1783 dmu_buf_will_dirty(ds_next->ds_dbuf, tx);
1784 ds_next->ds_phys->ds_prev_snap_obj =
1785 ds->ds_phys->ds_prev_snap_obj;
1786 ds_next->ds_phys->ds_prev_snap_txg =
1787 ds->ds_phys->ds_prev_snap_txg;
1788 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
1789 ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0);
1790
1791 /*
1792 * Transfer to our deadlist (which will become next's
1793 * new deadlist) any entries from next's current
1794 * deadlist which were born before prev, and free the
1795 * other entries.
1796 *
1797 * XXX we're doing this long task with the config lock held
1798 */
1799 while (bplist_iterate(&ds_next->ds_deadlist, &itor, &bp) == 0) {
1800 if (bp.blk_birth <= ds->ds_phys->ds_prev_snap_txg) {
1801 VERIFY(0 == bplist_enqueue(&ds->ds_deadlist,
1802 &bp, tx));
1803 if (ds_prev && !after_branch_point &&
1804 bp.blk_birth >
1805 ds_prev->ds_phys->ds_prev_snap_txg) {
1806 ds_prev->ds_phys->ds_unique_bytes +=
1807 bp_get_dasize(dp->dp_spa, &bp);
1808 }
1809 } else {
1810 used += bp_get_dasize(dp->dp_spa, &bp);
1811 compressed += BP_GET_PSIZE(&bp);
1812 uncompressed += BP_GET_UCSIZE(&bp);
1813 /* XXX check return value? */
1814 (void) dsl_free(zio, dp, tx->tx_txg,
1815 &bp, NULL, NULL, ARC_NOWAIT);
1816 }
1817 }
1818
1819 ASSERT3U(used, ==, ds->ds_phys->ds_unique_bytes);
1820
1821 /* change snapused */
1822 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
1823 -used, -compressed, -uncompressed, tx);
1824
1825 /* free next's deadlist */
1826 bplist_close(&ds_next->ds_deadlist);
1827 bplist_destroy(mos, ds_next->ds_phys->ds_deadlist_obj, tx);
1828
1829 /* set next's deadlist to our deadlist */
1830 bplist_close(&ds->ds_deadlist);
1831 ds_next->ds_phys->ds_deadlist_obj =
1832 ds->ds_phys->ds_deadlist_obj;
1833 VERIFY(0 == bplist_open(&ds_next->ds_deadlist, mos,
1834 ds_next->ds_phys->ds_deadlist_obj));
1835 ds->ds_phys->ds_deadlist_obj = 0;
1836
1837 if (ds_next->ds_phys->ds_next_snap_obj != 0) {
1838 /*
1839 * Update next's unique to include blocks which
1840 * were previously shared by only this snapshot
1841 * and it. Those blocks will be born after the
1842 * prev snap and before this snap, and will have
1843 * died after the next snap and before the one
1844 * after that (ie. be on the snap after next's
1845 * deadlist).
1846 *
1847 * XXX we're doing this long task with the
1848 * config lock held
1849 */
1850 dsl_dataset_t *ds_after_next;
1851 uint64_t space;
1852
1853 VERIFY(0 == dsl_dataset_hold_obj(dp,
1854 ds_next->ds_phys->ds_next_snap_obj,
1855 FTAG, &ds_after_next));
1856
1857 VERIFY(0 ==
1858 bplist_space_birthrange(&ds_after_next->ds_deadlist,
1859 ds->ds_phys->ds_prev_snap_txg,
1860 ds->ds_phys->ds_creation_txg, &space));
1861 ds_next->ds_phys->ds_unique_bytes += space;
1862
1863 dsl_dataset_rele(ds_after_next, FTAG);
1864 ASSERT3P(ds_next->ds_prev, ==, NULL);
1865 } else {
1866 ASSERT3P(ds_next->ds_prev, ==, ds);
1867 dsl_dataset_drop_ref(ds_next->ds_prev, ds_next);
1868 ds_next->ds_prev = NULL;
1869 if (ds_prev) {
1870 VERIFY(0 == dsl_dataset_get_ref(dp,
1871 ds->ds_phys->ds_prev_snap_obj,
1872 ds_next, &ds_next->ds_prev));
1873 }
1874
1875 dsl_dataset_recalc_head_uniq(ds_next);
1876
1877 /*
1878 * Reduce the amount of our unconsmed refreservation
1879 * being charged to our parent by the amount of
1880 * new unique data we have gained.
1881 */
1882 if (old_unique < ds_next->ds_reserved) {
1883 int64_t mrsdelta;
1884 uint64_t new_unique =
1885 ds_next->ds_phys->ds_unique_bytes;
1886
1887 ASSERT(old_unique <= new_unique);
1888 mrsdelta = MIN(new_unique - old_unique,
1889 ds_next->ds_reserved - old_unique);
1890 dsl_dir_diduse_space(ds->ds_dir,
1891 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx);
1892 }
1893 }
1894 dsl_dataset_rele(ds_next, FTAG);
1895 } else {
1896 /*
1897 * There's no next snapshot, so this is a head dataset.
1898 * Destroy the deadlist. Unless it's a clone, the
1899 * deadlist should be empty. (If it's a clone, it's
1900 * safe to ignore the deadlist contents.)
1901 */
1902 struct killarg ka;
1903
1904 ASSERT(after_branch_point || bplist_empty(&ds->ds_deadlist));
1905 bplist_close(&ds->ds_deadlist);
1906 bplist_destroy(mos, ds->ds_phys->ds_deadlist_obj, tx);
1907 ds->ds_phys->ds_deadlist_obj = 0;
1908
1909 /*
1910 * Free everything that we point to (that's born after
1911 * the previous snapshot, if we are a clone)
1912 *
1913 * NB: this should be very quick, because we already
1914 * freed all the objects in open context.
1915 */
1916 ka.ds = ds;
1917 ka.zio = zio;
1918 ka.tx = tx;
1919 err = traverse_dataset(ds, ds->ds_phys->ds_prev_snap_txg,
1920 TRAVERSE_POST, kill_blkptr, &ka);
1921 ASSERT3U(err, ==, 0);
1922 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) ||
1923 ds->ds_phys->ds_unique_bytes == 0);
1924 }
1925
1926 err = zio_wait(zio);
1927 ASSERT3U(err, ==, 0);
1928
1929 if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) {
1930 /* Erase the link in the dir */
1931 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx);
1932 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0;
1933 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0);
1934 err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx);
1935 ASSERT(err == 0);
1936 } else {
1937 /* remove from snapshot namespace */
1938 dsl_dataset_t *ds_head;
1939 ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0);
1940 VERIFY(0 == dsl_dataset_hold_obj(dp,
1941 ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head));
1942 VERIFY(0 == dsl_dataset_get_snapname(ds));
1943 #ifdef ZFS_DEBUG
1944 {
1945 uint64_t val;
1946
1947 err = dsl_dataset_snap_lookup(ds_head,
1948 ds->ds_snapname, &val);
1949 ASSERT3U(err, ==, 0);
1950 ASSERT3U(val, ==, obj);
1951 }
1952 #endif
1953 err = dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx);
1954 ASSERT(err == 0);
1955 dsl_dataset_rele(ds_head, FTAG);
1956 }
1957
1958 if (ds_prev && ds->ds_prev != ds_prev)
1959 dsl_dataset_rele(ds_prev, FTAG);
1960
1961 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx);
1962 spa_history_internal_log(LOG_DS_DESTROY, dp->dp_spa, tx,
1963 cr, "dataset = %llu", ds->ds_object);
1964
1965 if (ds->ds_phys->ds_next_clones_obj != 0) {
1966 uint64_t count;
1967 ASSERT(0 == zap_count(mos,
1968 ds->ds_phys->ds_next_clones_obj, &count) && count == 0);
1969 VERIFY(0 == dmu_object_free(mos,
1970 ds->ds_phys->ds_next_clones_obj, tx));
1971 }
1972 if (ds->ds_phys->ds_props_obj != 0)
1973 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_props_obj, tx));
1974 if (ds->ds_phys->ds_userrefs_obj != 0)
1975 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx));
1976 dsl_dir_close(ds->ds_dir, ds);
1977 ds->ds_dir = NULL;
1978 dsl_dataset_drain_refs(ds, tag);
1979 VERIFY(0 == dmu_object_free(mos, obj, tx));
1980
1981 if (dsda->rm_origin) {
1982 /*
1983 * Remove the origin of the clone we just destroyed.
1984 */
1985 dsl_dataset_t *origin = ds->ds_prev;
1986 struct dsl_ds_destroyarg ndsda = {0};
1987
1988 ASSERT3P(origin, ==, dsda->rm_origin);
1989 if (origin->ds_user_ptr) {
1990 origin->ds_user_evict_func(origin, origin->ds_user_ptr);
1991 origin->ds_user_ptr = NULL;
1992 }
1993
1994 dsl_dataset_rele(origin, tag);
1995 ds->ds_prev = NULL;
1996
1997 ndsda.ds = origin;
1998 dsl_dataset_destroy_sync(&ndsda, tag, cr, tx);
1999 }
2000 }
2001
2002 static int
2003 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx)
2004 {
2005 uint64_t asize;
2006
2007 if (!dmu_tx_is_syncing(tx))
2008 return (0);
2009
2010 /*
2011 * If there's an fs-only reservation, any blocks that might become
2012 * owned by the snapshot dataset must be accommodated by space
2013 * outside of the reservation.
2014 */
2015 asize = MIN(dsl_dataset_unique(ds), ds->ds_reserved);
2016 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, FALSE))
2017 return (ENOSPC);
2018
2019 /*
2020 * Propogate any reserved space for this snapshot to other
2021 * snapshot checks in this sync group.
2022 */
2023 if (asize > 0)
2024 dsl_dir_willuse_space(ds->ds_dir, asize, tx);
2025
2026 return (0);
2027 }
2028
2029 /* ARGSUSED */
2030 int
2031 dsl_dataset_snapshot_check(void *arg1, void *arg2, dmu_tx_t *tx)
2032 {
2033 dsl_dataset_t *ds = arg1;
2034 const char *snapname = arg2;
2035 int err;
2036 uint64_t value;
2037
2038 /*
2039 * We don't allow multiple snapshots of the same txg. If there
2040 * is already one, try again.
2041 */
2042 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg)
2043 return (EAGAIN);
2044
2045 /*
2046 * Check for conflicting name snapshot name.
2047 */
2048 err = dsl_dataset_snap_lookup(ds, snapname, &value);
2049 if (err == 0)
2050 return (EEXIST);
2051 if (err != ENOENT)
2052 return (err);
2053
2054 /*
2055 * Check that the dataset's name is not too long. Name consists
2056 * of the dataset's length + 1 for the @-sign + snapshot name's length
2057 */
2058 if (dsl_dataset_namelen(ds) + 1 + strlen(snapname) >= MAXNAMELEN)
2059 return (ENAMETOOLONG);
2060
2061 err = dsl_dataset_snapshot_reserve_space(ds, tx);
2062 if (err)
2063 return (err);
2064
2065 ds->ds_trysnap_txg = tx->tx_txg;
2066 return (0);
2067 }
2068
2069 void
2070 dsl_dataset_snapshot_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
2071 {
2072 dsl_dataset_t *ds = arg1;
2073 const char *snapname = arg2;
2074 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2075 dmu_buf_t *dbuf;
2076 dsl_dataset_phys_t *dsphys;
2077 uint64_t dsobj, crtxg;
2078 objset_t *mos = dp->dp_meta_objset;
2079 int err;
2080
2081 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
2082
2083 /*
2084 * The origin's ds_creation_txg has to be < TXG_INITIAL
2085 */
2086 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0)
2087 crtxg = 1;
2088 else
2089 crtxg = tx->tx_txg;
2090
2091 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
2092 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
2093 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
2094 dmu_buf_will_dirty(dbuf, tx);
2095 dsphys = dbuf->db_data;
2096 bzero(dsphys, sizeof (dsl_dataset_phys_t));
2097 dsphys->ds_dir_obj = ds->ds_dir->dd_object;
2098 dsphys->ds_fsid_guid = unique_create();
2099 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
2100 sizeof (dsphys->ds_guid));
2101 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj;
2102 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg;
2103 dsphys->ds_next_snap_obj = ds->ds_object;
2104 dsphys->ds_num_children = 1;
2105 dsphys->ds_creation_time = gethrestime_sec();
2106 dsphys->ds_creation_txg = crtxg;
2107 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj;
2108 dsphys->ds_used_bytes = ds->ds_phys->ds_used_bytes;
2109 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes;
2110 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes;
2111 dsphys->ds_flags = ds->ds_phys->ds_flags;
2112 dsphys->ds_bp = ds->ds_phys->ds_bp;
2113 dmu_buf_rele(dbuf, FTAG);
2114
2115 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0);
2116 if (ds->ds_prev) {
2117 uint64_t next_clones_obj =
2118 ds->ds_prev->ds_phys->ds_next_clones_obj;
2119 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj ==
2120 ds->ds_object ||
2121 ds->ds_prev->ds_phys->ds_num_children > 1);
2122 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) {
2123 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
2124 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
2125 ds->ds_prev->ds_phys->ds_creation_txg);
2126 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj;
2127 } else if (next_clones_obj != 0) {
2128 VERIFY3U(0, ==, zap_remove_int(mos,
2129 next_clones_obj, dsphys->ds_next_snap_obj, tx));
2130 VERIFY3U(0, ==, zap_add_int(mos,
2131 next_clones_obj, dsobj, tx));
2132 }
2133 }
2134
2135 /*
2136 * If we have a reference-reservation on this dataset, we will
2137 * need to increase the amount of refreservation being charged
2138 * since our unique space is going to zero.
2139 */
2140 if (ds->ds_reserved) {
2141 int64_t add = MIN(dsl_dataset_unique(ds), ds->ds_reserved);
2142 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV,
2143 add, 0, 0, tx);
2144 }
2145
2146 bplist_close(&ds->ds_deadlist);
2147 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2148 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg);
2149 ds->ds_phys->ds_prev_snap_obj = dsobj;
2150 ds->ds_phys->ds_prev_snap_txg = crtxg;
2151 ds->ds_phys->ds_unique_bytes = 0;
2152 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
2153 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
2154 ds->ds_phys->ds_deadlist_obj =
2155 bplist_create(mos, DSL_DEADLIST_BLOCKSIZE, tx);
2156 VERIFY(0 == bplist_open(&ds->ds_deadlist, mos,
2157 ds->ds_phys->ds_deadlist_obj));
2158
2159 dprintf("snap '%s' -> obj %llu\n", snapname, dsobj);
2160 err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj,
2161 snapname, 8, 1, &dsobj, tx);
2162 ASSERT(err == 0);
2163
2164 if (ds->ds_prev)
2165 dsl_dataset_drop_ref(ds->ds_prev, ds);
2166 VERIFY(0 == dsl_dataset_get_ref(dp,
2167 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev));
2168
2169 dsl_pool_ds_snapshotted(ds, tx);
2170
2171 spa_history_internal_log(LOG_DS_SNAPSHOT, dp->dp_spa, tx, cr,
2172 "dataset = %llu", dsobj);
2173 }
2174
2175 void
2176 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx)
2177 {
2178 ASSERT(dmu_tx_is_syncing(tx));
2179 ASSERT(ds->ds_user_ptr != NULL);
2180 ASSERT(ds->ds_phys->ds_next_snap_obj == 0);
2181
2182 /*
2183 * in case we had to change ds_fsid_guid when we opened it,
2184 * sync it out now.
2185 */
2186 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2187 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid;
2188
2189 dsl_dir_dirty(ds->ds_dir, tx);
2190 dmu_objset_sync(ds->ds_user_ptr, zio, tx);
2191 }
2192
2193 void
2194 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv)
2195 {
2196 uint64_t refd, avail, uobjs, aobjs;
2197
2198 dsl_dir_stats(ds->ds_dir, nv);
2199
2200 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs);
2201 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail);
2202 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd);
2203
2204 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION,
2205 ds->ds_phys->ds_creation_time);
2206 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG,
2207 ds->ds_phys->ds_creation_txg);
2208 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA,
2209 ds->ds_quota);
2210 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION,
2211 ds->ds_reserved);
2212 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID,
2213 ds->ds_phys->ds_guid);
2214 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS, ds->ds_userrefs);
2215 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY,
2216 DS_IS_DEFER_DESTROY(ds) ? 1 : 0);
2217
2218 if (ds->ds_phys->ds_next_snap_obj) {
2219 /*
2220 * This is a snapshot; override the dd's space used with
2221 * our unique space and compression ratio.
2222 */
2223 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED,
2224 ds->ds_phys->ds_unique_bytes);
2225 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO,
2226 ds->ds_phys->ds_compressed_bytes == 0 ? 100 :
2227 (ds->ds_phys->ds_uncompressed_bytes * 100 /
2228 ds->ds_phys->ds_compressed_bytes));
2229 }
2230 }
2231
2232 void
2233 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat)
2234 {
2235 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg;
2236 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT;
2237 stat->dds_guid = ds->ds_phys->ds_guid;
2238 if (ds->ds_phys->ds_next_snap_obj) {
2239 stat->dds_is_snapshot = B_TRUE;
2240 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1;
2241 } else {
2242 stat->dds_is_snapshot = B_FALSE;
2243 stat->dds_num_clones = 0;
2244 }
2245
2246 /* clone origin is really a dsl_dir thing... */
2247 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER);
2248 if (dsl_dir_is_clone(ds->ds_dir)) {
2249 dsl_dataset_t *ods;
2250
2251 VERIFY(0 == dsl_dataset_get_ref(ds->ds_dir->dd_pool,
2252 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods));
2253 dsl_dataset_name(ods, stat->dds_origin);
2254 dsl_dataset_drop_ref(ods, FTAG);
2255 } else {
2256 stat->dds_origin[0] = '\0';
2257 }
2258 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock);
2259 }
2260
2261 uint64_t
2262 dsl_dataset_fsid_guid(dsl_dataset_t *ds)
2263 {
2264 return (ds->ds_fsid_guid);
2265 }
2266
2267 void
2268 dsl_dataset_space(dsl_dataset_t *ds,
2269 uint64_t *refdbytesp, uint64_t *availbytesp,
2270 uint64_t *usedobjsp, uint64_t *availobjsp)
2271 {
2272 *refdbytesp = ds->ds_phys->ds_used_bytes;
2273 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE);
2274 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes)
2275 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes;
2276 if (ds->ds_quota != 0) {
2277 /*
2278 * Adjust available bytes according to refquota
2279 */
2280 if (*refdbytesp < ds->ds_quota)
2281 *availbytesp = MIN(*availbytesp,
2282 ds->ds_quota - *refdbytesp);
2283 else
2284 *availbytesp = 0;
2285 }
2286 *usedobjsp = ds->ds_phys->ds_bp.blk_fill;
2287 *availobjsp = DN_MAX_OBJECT - *usedobjsp;
2288 }
2289
2290 boolean_t
2291 dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds)
2292 {
2293 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2294
2295 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) ||
2296 dsl_pool_sync_context(dp));
2297 if (ds->ds_prev == NULL)
2298 return (B_FALSE);
2299 if (ds->ds_phys->ds_bp.blk_birth >
2300 ds->ds_prev->ds_phys->ds_creation_txg)
2301 return (B_TRUE);
2302 return (B_FALSE);
2303 }
2304
2305 /* ARGSUSED */
2306 static int
2307 dsl_dataset_snapshot_rename_check(void *arg1, void *arg2, dmu_tx_t *tx)
2308 {
2309 dsl_dataset_t *ds = arg1;
2310 char *newsnapname = arg2;
2311 dsl_dir_t *dd = ds->ds_dir;
2312 dsl_dataset_t *hds;
2313 uint64_t val;
2314 int err;
2315
2316 err = dsl_dataset_hold_obj(dd->dd_pool,
2317 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds);
2318 if (err)
2319 return (err);
2320
2321 /* new name better not be in use */
2322 err = dsl_dataset_snap_lookup(hds, newsnapname, &val);
2323 dsl_dataset_rele(hds, FTAG);
2324
2325 if (err == 0)
2326 err = EEXIST;
2327 else if (err == ENOENT)
2328 err = 0;
2329
2330 /* dataset name + 1 for the "@" + the new snapshot name must fit */
2331 if (dsl_dir_namelen(ds->ds_dir) + 1 + strlen(newsnapname) >= MAXNAMELEN)
2332 err = ENAMETOOLONG;
2333
2334 return (err);
2335 }
2336
2337 static void
2338 dsl_dataset_snapshot_rename_sync(void *arg1, void *arg2,
2339 cred_t *cr, dmu_tx_t *tx)
2340 {
2341 dsl_dataset_t *ds = arg1;
2342 const char *newsnapname = arg2;
2343 dsl_dir_t *dd = ds->ds_dir;
2344 objset_t *mos = dd->dd_pool->dp_meta_objset;
2345 dsl_dataset_t *hds;
2346 int err;
2347
2348 ASSERT(ds->ds_phys->ds_next_snap_obj != 0);
2349
2350 VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool,
2351 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds));
2352
2353 VERIFY(0 == dsl_dataset_get_snapname(ds));
2354 err = dsl_dataset_snap_remove(hds, ds->ds_snapname, tx);
2355 ASSERT3U(err, ==, 0);
2356 mutex_enter(&ds->ds_lock);
2357 (void) strcpy(ds->ds_snapname, newsnapname);
2358 mutex_exit(&ds->ds_lock);
2359 err = zap_add(mos, hds->ds_phys->ds_snapnames_zapobj,
2360 ds->ds_snapname, 8, 1, &ds->ds_object, tx);
2361 ASSERT3U(err, ==, 0);
2362
2363 spa_history_internal_log(LOG_DS_RENAME, dd->dd_pool->dp_spa, tx,
2364 cr, "dataset = %llu", ds->ds_object);
2365 dsl_dataset_rele(hds, FTAG);
2366 }
2367
2368 struct renamesnaparg {
2369 dsl_sync_task_group_t *dstg;
2370 char failed[MAXPATHLEN];
2371 char *oldsnap;
2372 char *newsnap;
2373 };
2374
2375 static int
2376 dsl_snapshot_rename_one(char *name, void *arg)
2377 {
2378 struct renamesnaparg *ra = arg;
2379 dsl_dataset_t *ds = NULL;
2380 char *cp;
2381 int err;
2382
2383 cp = name + strlen(name);
2384 *cp = '@';
2385 (void) strcpy(cp + 1, ra->oldsnap);
2386
2387 /*
2388 * For recursive snapshot renames the parent won't be changing
2389 * so we just pass name for both the to/from argument.
2390 */
2391 err = zfs_secpolicy_rename_perms(name, name, CRED());
2392 if (err == ENOENT) {
2393 return (0);
2394 } else if (err) {
2395 (void) strcpy(ra->failed, name);
2396 return (err);
2397 }
2398
2399 #ifdef _KERNEL
2400 /*
2401 * For all filesystems undergoing rename, we'll need to unmount it.
2402 */
2403 (void) zfs_unmount_snap(name, NULL);
2404 #endif
2405 err = dsl_dataset_hold(name, ra->dstg, &ds);
2406 *cp = '\0';
2407 if (err == ENOENT) {
2408 return (0);
2409 } else if (err) {
2410 (void) strcpy(ra->failed, name);
2411 return (err);
2412 }
2413
2414 dsl_sync_task_create(ra->dstg, dsl_dataset_snapshot_rename_check,
2415 dsl_dataset_snapshot_rename_sync, ds, ra->newsnap, 0);
2416
2417 return (0);
2418 }
2419
2420 static int
2421 dsl_recursive_rename(char *oldname, const char *newname)
2422 {
2423 int err;
2424 struct renamesnaparg *ra;
2425 dsl_sync_task_t *dst;
2426 spa_t *spa;
2427 char *cp, *fsname = spa_strdup(oldname);
2428 int len = strlen(oldname);
2429
2430 /* truncate the snapshot name to get the fsname */
2431 cp = strchr(fsname, '@');
2432 *cp = '\0';
2433
2434 err = spa_open(fsname, &spa, FTAG);
2435 if (err) {
2436 kmem_free(fsname, len + 1);
2437 return (err);
2438 }
2439 ra = kmem_alloc(sizeof (struct renamesnaparg), KM_SLEEP);
2440 ra->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
2441
2442 ra->oldsnap = strchr(oldname, '@') + 1;
2443 ra->newsnap = strchr(newname, '@') + 1;
2444 *ra->failed = '\0';
2445
2446 err = dmu_objset_find(fsname, dsl_snapshot_rename_one, ra,
2447 DS_FIND_CHILDREN);
2448 kmem_free(fsname, len + 1);
2449
2450 if (err == 0) {
2451 err = dsl_sync_task_group_wait(ra->dstg);
2452 }
2453
2454 for (dst = list_head(&ra->dstg->dstg_tasks); dst;
2455 dst = list_next(&ra->dstg->dstg_tasks, dst)) {
2456 dsl_dataset_t *ds = dst->dst_arg1;
2457 if (dst->dst_err) {
2458 dsl_dir_name(ds->ds_dir, ra->failed);
2459 (void) strcat(ra->failed, "@");
2460 (void) strcat(ra->failed, ra->newsnap);
2461 }
2462 dsl_dataset_rele(ds, ra->dstg);
2463 }
2464
2465 if (err)
2466 (void) strcpy(oldname, ra->failed);
2467
2468 dsl_sync_task_group_destroy(ra->dstg);
2469 kmem_free(ra, sizeof (struct renamesnaparg));
2470 spa_close(spa, FTAG);
2471 return (err);
2472 }
2473
2474 static int
2475 dsl_valid_rename(char *oldname, void *arg)
2476 {
2477 int delta = *(int *)arg;
2478
2479 if (strlen(oldname) + delta >= MAXNAMELEN)
2480 return (ENAMETOOLONG);
2481
2482 return (0);
2483 }
2484
2485 #pragma weak dmu_objset_rename = dsl_dataset_rename
2486 int
2487 dsl_dataset_rename(char *oldname, const char *newname, boolean_t recursive)
2488 {
2489 dsl_dir_t *dd;
2490 dsl_dataset_t *ds;
2491 const char *tail;
2492 int err;
2493
2494 err = dsl_dir_open(oldname, FTAG, &dd, &tail);
2495 if (err)
2496 return (err);
2497 /*
2498 * If there are more than 2 references there may be holds
2499 * hanging around that haven't been cleared out yet.
2500 */
2501 if (dmu_buf_refcount(dd->dd_dbuf) > 2)
2502 txg_wait_synced(dd->dd_pool, 0);
2503 if (tail == NULL) {
2504 int delta = strlen(newname) - strlen(oldname);
2505
2506 /* if we're growing, validate child name lengths */
2507 if (delta > 0)
2508 err = dmu_objset_find(oldname, dsl_valid_rename,
2509 &delta, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS);
2510
2511 if (!err)
2512 err = dsl_dir_rename(dd, newname);
2513 dsl_dir_close(dd, FTAG);
2514 return (err);
2515 }
2516 if (tail[0] != '@') {
2517 /* the name ended in a nonexistant component */
2518 dsl_dir_close(dd, FTAG);
2519 return (ENOENT);
2520 }
2521
2522 dsl_dir_close(dd, FTAG);
2523
2524 /* new name must be snapshot in same filesystem */
2525 tail = strchr(newname, '@');
2526 if (tail == NULL)
2527 return (EINVAL);
2528 tail++;
2529 if (strncmp(oldname, newname, tail - newname) != 0)
2530 return (EXDEV);
2531
2532 if (recursive) {
2533 err = dsl_recursive_rename(oldname, newname);
2534 } else {
2535 err = dsl_dataset_hold(oldname, FTAG, &ds);
2536 if (err)
2537 return (err);
2538
2539 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
2540 dsl_dataset_snapshot_rename_check,
2541 dsl_dataset_snapshot_rename_sync, ds, (char *)tail, 1);
2542
2543 dsl_dataset_rele(ds, FTAG);
2544 }
2545
2546 return (err);
2547 }
2548
2549 struct promotenode {
2550 list_node_t link;
2551 dsl_dataset_t *ds;
2552 };
2553
2554 struct promotearg {
2555 list_t shared_snaps, origin_snaps, clone_snaps;
2556 dsl_dataset_t *origin_origin, *origin_head;
2557 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap;
2558 };
2559
2560 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep);
2561
2562 /* ARGSUSED */
2563 static int
2564 dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx)
2565 {
2566 dsl_dataset_t *hds = arg1;
2567 struct promotearg *pa = arg2;
2568 struct promotenode *snap = list_head(&pa->shared_snaps);
2569 dsl_dataset_t *origin_ds = snap->ds;
2570 int err;
2571
2572 /* Check that it is a real clone */
2573 if (!dsl_dir_is_clone(hds->ds_dir))
2574 return (EINVAL);
2575
2576 /* Since this is so expensive, don't do the preliminary check */
2577 if (!dmu_tx_is_syncing(tx))
2578 return (0);
2579
2580 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE)
2581 return (EXDEV);
2582
2583 /* compute origin's new unique space */
2584 snap = list_tail(&pa->clone_snaps);
2585 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2586 err = bplist_space_birthrange(&snap->ds->ds_deadlist,
2587 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX, &pa->unique);
2588 if (err)
2589 return (err);
2590
2591 /*
2592 * Walk the snapshots that we are moving
2593 *
2594 * Compute space to transfer. Consider the incremental changes
2595 * to used for each snapshot:
2596 * (my used) = (prev's used) + (blocks born) - (blocks killed)
2597 * So each snapshot gave birth to:
2598 * (blocks born) = (my used) - (prev's used) + (blocks killed)
2599 * So a sequence would look like:
2600 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0)
2601 * Which simplifies to:
2602 * uN + kN + kN-1 + ... + k1 + k0
2603 * Note however, if we stop before we reach the ORIGIN we get:
2604 * uN + kN + kN-1 + ... + kM - uM-1
2605 */
2606 pa->used = origin_ds->ds_phys->ds_used_bytes;
2607 pa->comp = origin_ds->ds_phys->ds_compressed_bytes;
2608 pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes;
2609 for (snap = list_head(&pa->shared_snaps); snap;
2610 snap = list_next(&pa->shared_snaps, snap)) {
2611 uint64_t val, dlused, dlcomp, dluncomp;
2612 dsl_dataset_t *ds = snap->ds;
2613
2614 /* Check that the snapshot name does not conflict */
2615 VERIFY(0 == dsl_dataset_get_snapname(ds));
2616 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val);
2617 if (err == 0)
2618 return (EEXIST);
2619 if (err != ENOENT)
2620 return (err);
2621
2622 /* The very first snapshot does not have a deadlist */
2623 if (ds->ds_phys->ds_prev_snap_obj == 0)
2624 continue;
2625
2626 if (err = bplist_space(&ds->ds_deadlist,
2627 &dlused, &dlcomp, &dluncomp))
2628 return (err);
2629 pa->used += dlused;
2630 pa->comp += dlcomp;
2631 pa->uncomp += dluncomp;
2632 }
2633
2634 /*
2635 * If we are a clone of a clone then we never reached ORIGIN,
2636 * so we need to subtract out the clone origin's used space.
2637 */
2638 if (pa->origin_origin) {
2639 pa->used -= pa->origin_origin->ds_phys->ds_used_bytes;
2640 pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes;
2641 pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes;
2642 }
2643
2644 /* Check that there is enough space here */
2645 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir,
2646 pa->used);
2647 if (err)
2648 return (err);
2649
2650 /*
2651 * Compute the amounts of space that will be used by snapshots
2652 * after the promotion (for both origin and clone). For each,
2653 * it is the amount of space that will be on all of their
2654 * deadlists (that was not born before their new origin).
2655 */
2656 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2657 uint64_t space;
2658
2659 /*
2660 * Note, typically this will not be a clone of a clone,
2661 * so snap->ds->ds_origin_txg will be < TXG_INITIAL, so
2662 * these snaplist_space() -> bplist_space_birthrange()
2663 * calls will be fast because they do not have to
2664 * iterate over all bps.
2665 */
2666 snap = list_head(&pa->origin_snaps);
2667 err = snaplist_space(&pa->shared_snaps,
2668 snap->ds->ds_origin_txg, &pa->cloneusedsnap);
2669 if (err)
2670 return (err);
2671
2672 err = snaplist_space(&pa->clone_snaps,
2673 snap->ds->ds_origin_txg, &space);
2674 if (err)
2675 return (err);
2676 pa->cloneusedsnap += space;
2677 }
2678 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2679 err = snaplist_space(&pa->origin_snaps,
2680 origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap);
2681 if (err)
2682 return (err);
2683 }
2684
2685 return (0);
2686 }
2687
2688 static void
2689 dsl_dataset_promote_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
2690 {
2691 dsl_dataset_t *hds = arg1;
2692 struct promotearg *pa = arg2;
2693 struct promotenode *snap = list_head(&pa->shared_snaps);
2694 dsl_dataset_t *origin_ds = snap->ds;
2695 dsl_dataset_t *origin_head;
2696 dsl_dir_t *dd = hds->ds_dir;
2697 dsl_pool_t *dp = hds->ds_dir->dd_pool;
2698 dsl_dir_t *odd = NULL;
2699 uint64_t oldnext_obj;
2700 int64_t delta;
2701
2702 ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE));
2703
2704 snap = list_head(&pa->origin_snaps);
2705 origin_head = snap->ds;
2706
2707 /*
2708 * We need to explicitly open odd, since origin_ds's dd will be
2709 * changing.
2710 */
2711 VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object,
2712 NULL, FTAG, &odd));
2713
2714 /* change origin's next snap */
2715 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx);
2716 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj;
2717 snap = list_tail(&pa->clone_snaps);
2718 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2719 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object;
2720
2721 /* change the origin's next clone */
2722 if (origin_ds->ds_phys->ds_next_clones_obj) {
2723 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
2724 origin_ds->ds_phys->ds_next_clones_obj,
2725 origin_ds->ds_phys->ds_next_snap_obj, tx));
2726 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2727 origin_ds->ds_phys->ds_next_clones_obj,
2728 oldnext_obj, tx));
2729 }
2730
2731 /* change origin */
2732 dmu_buf_will_dirty(dd->dd_dbuf, tx);
2733 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object);
2734 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj;
2735 hds->ds_origin_txg = origin_head->ds_origin_txg;
2736 dmu_buf_will_dirty(odd->dd_dbuf, tx);
2737 odd->dd_phys->dd_origin_obj = origin_ds->ds_object;
2738 origin_head->ds_origin_txg = origin_ds->ds_phys->ds_creation_txg;
2739
2740 /* move snapshots to this dir */
2741 for (snap = list_head(&pa->shared_snaps); snap;
2742 snap = list_next(&pa->shared_snaps, snap)) {
2743 dsl_dataset_t *ds = snap->ds;
2744
2745 /* unregister props as dsl_dir is changing */
2746 if (ds->ds_user_ptr) {
2747 ds->ds_user_evict_func(ds, ds->ds_user_ptr);
2748 ds->ds_user_ptr = NULL;
2749 }
2750 /* move snap name entry */
2751 VERIFY(0 == dsl_dataset_get_snapname(ds));
2752 VERIFY(0 == dsl_dataset_snap_remove(origin_head,
2753 ds->ds_snapname, tx));
2754 VERIFY(0 == zap_add(dp->dp_meta_objset,
2755 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname,
2756 8, 1, &ds->ds_object, tx));
2757 /* change containing dsl_dir */
2758 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2759 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object);
2760 ds->ds_phys->ds_dir_obj = dd->dd_object;
2761 ASSERT3P(ds->ds_dir, ==, odd);
2762 dsl_dir_close(ds->ds_dir, ds);
2763 VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object,
2764 NULL, ds, &ds->ds_dir));
2765
2766 ASSERT3U(dsl_prop_numcb(ds), ==, 0);
2767 }
2768
2769 /*
2770 * Change space accounting.
2771 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either
2772 * both be valid, or both be 0 (resulting in delta == 0). This
2773 * is true for each of {clone,origin} independently.
2774 */
2775
2776 delta = pa->cloneusedsnap -
2777 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2778 ASSERT3S(delta, >=, 0);
2779 ASSERT3U(pa->used, >=, delta);
2780 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx);
2781 dsl_dir_diduse_space(dd, DD_USED_HEAD,
2782 pa->used - delta, pa->comp, pa->uncomp, tx);
2783
2784 delta = pa->originusedsnap -
2785 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2786 ASSERT3S(delta, <=, 0);
2787 ASSERT3U(pa->used, >=, -delta);
2788 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx);
2789 dsl_dir_diduse_space(odd, DD_USED_HEAD,
2790 -pa->used - delta, -pa->comp, -pa->uncomp, tx);
2791
2792 origin_ds->ds_phys->ds_unique_bytes = pa->unique;
2793
2794 /* log history record */
2795 spa_history_internal_log(LOG_DS_PROMOTE, dd->dd_pool->dp_spa, tx,
2796 cr, "dataset = %llu", hds->ds_object);
2797
2798 dsl_dir_close(odd, FTAG);
2799 }
2800
2801 static char *snaplist_tag = "snaplist";
2802 /*
2803 * Make a list of dsl_dataset_t's for the snapshots between first_obj
2804 * (exclusive) and last_obj (inclusive). The list will be in reverse
2805 * order (last_obj will be the list_head()). If first_obj == 0, do all
2806 * snapshots back to this dataset's origin.
2807 */
2808 static int
2809 snaplist_make(dsl_pool_t *dp, boolean_t own,
2810 uint64_t first_obj, uint64_t last_obj, list_t *l)
2811 {
2812 uint64_t obj = last_obj;
2813
2814 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock));
2815
2816 list_create(l, sizeof (struct promotenode),
2817 offsetof(struct promotenode, link));
2818
2819 while (obj != first_obj) {
2820 dsl_dataset_t *ds;
2821 struct promotenode *snap;
2822 int err;
2823
2824 if (own) {
2825 err = dsl_dataset_own_obj(dp, obj,
2826 0, snaplist_tag, &ds);
2827 if (err == 0)
2828 dsl_dataset_make_exclusive(ds, snaplist_tag);
2829 } else {
2830 err = dsl_dataset_hold_obj(dp, obj, snaplist_tag, &ds);
2831 }
2832 if (err == ENOENT) {
2833 /* lost race with snapshot destroy */
2834 struct promotenode *last = list_tail(l);
2835 ASSERT(obj != last->ds->ds_phys->ds_prev_snap_obj);
2836 obj = last->ds->ds_phys->ds_prev_snap_obj;
2837 continue;
2838 } else if (err) {
2839 return (err);
2840 }
2841
2842 if (first_obj == 0)
2843 first_obj = ds->ds_dir->dd_phys->dd_origin_obj;
2844
2845 snap = kmem_alloc(sizeof (struct promotenode), KM_SLEEP);
2846 snap->ds = ds;
2847 list_insert_tail(l, snap);
2848 obj = ds->ds_phys->ds_prev_snap_obj;
2849 }
2850
2851 return (0);
2852 }
2853
2854 static int
2855 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep)
2856 {
2857 struct promotenode *snap;
2858
2859 *spacep = 0;
2860 for (snap = list_head(l); snap; snap = list_next(l, snap)) {
2861 uint64_t used;
2862 int err = bplist_space_birthrange(&snap->ds->ds_deadlist,
2863 mintxg, UINT64_MAX, &used);
2864 if (err)
2865 return (err);
2866 *spacep += used;
2867 }
2868 return (0);
2869 }
2870
2871 static void
2872 snaplist_destroy(list_t *l, boolean_t own)
2873 {
2874 struct promotenode *snap;
2875
2876 if (!l || !list_link_active(&l->list_head))
2877 return;
2878
2879 while ((snap = list_tail(l)) != NULL) {
2880 list_remove(l, snap);
2881 if (own)
2882 dsl_dataset_disown(snap->ds, snaplist_tag);
2883 else
2884 dsl_dataset_rele(snap->ds, snaplist_tag);
2885 kmem_free(snap, sizeof (struct promotenode));
2886 }
2887 list_destroy(l);
2888 }
2889
2890 /*
2891 * Promote a clone. Nomenclature note:
2892 * "clone" or "cds": the original clone which is being promoted
2893 * "origin" or "ods": the snapshot which is originally clone's origin
2894 * "origin head" or "ohds": the dataset which is the head
2895 * (filesystem/volume) for the origin
2896 * "origin origin": the origin of the origin's filesystem (typically
2897 * NULL, indicating that the clone is not a clone of a clone).
2898 */
2899 int
2900 dsl_dataset_promote(const char *name)
2901 {
2902 dsl_dataset_t *ds;
2903 dsl_dir_t *dd;
2904 dsl_pool_t *dp;
2905 dmu_object_info_t doi;
2906 struct promotearg pa = { 0 };
2907 struct promotenode *snap;
2908 int err;
2909
2910 err = dsl_dataset_hold(name, FTAG, &ds);
2911 if (err)
2912 return (err);
2913 dd = ds->ds_dir;
2914 dp = dd->dd_pool;
2915
2916 err = dmu_object_info(dp->dp_meta_objset,
2917 ds->ds_phys->ds_snapnames_zapobj, &doi);
2918 if (err) {
2919 dsl_dataset_rele(ds, FTAG);
2920 return (err);
2921 }
2922
2923 if (dsl_dataset_is_snapshot(ds) || dd->dd_phys->dd_origin_obj == 0) {
2924 dsl_dataset_rele(ds, FTAG);
2925 return (EINVAL);
2926 }
2927
2928 /*
2929 * We are going to inherit all the snapshots taken before our
2930 * origin (i.e., our new origin will be our parent's origin).
2931 * Take ownership of them so that we can rename them into our
2932 * namespace.
2933 */
2934 rw_enter(&dp->dp_config_rwlock, RW_READER);
2935
2936 err = snaplist_make(dp, B_TRUE, 0, dd->dd_phys->dd_origin_obj,
2937 &pa.shared_snaps);
2938 if (err != 0)
2939 goto out;
2940
2941 err = snaplist_make(dp, B_FALSE, 0, ds->ds_object, &pa.clone_snaps);
2942 if (err != 0)
2943 goto out;
2944
2945 snap = list_head(&pa.shared_snaps);
2946 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj);
2947 err = snaplist_make(dp, B_FALSE, dd->dd_phys->dd_origin_obj,
2948 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj, &pa.origin_snaps);
2949 if (err != 0)
2950 goto out;
2951
2952 if (dsl_dir_is_clone(snap->ds->ds_dir)) {
2953 err = dsl_dataset_own_obj(dp,
2954 snap->ds->ds_dir->dd_phys->dd_origin_obj,
2955 0, FTAG, &pa.origin_origin);
2956 if (err != 0)
2957 goto out;
2958 }
2959
2960 out:
2961 rw_exit(&dp->dp_config_rwlock);
2962
2963 /*
2964 * Add in 128x the snapnames zapobj size, since we will be moving
2965 * a bunch of snapnames to the promoted ds, and dirtying their
2966 * bonus buffers.
2967 */
2968 if (err == 0) {
2969 err = dsl_sync_task_do(dp, dsl_dataset_promote_check,
2970 dsl_dataset_promote_sync, ds, &pa,
2971 2 + 2 * doi.doi_physical_blks);
2972 }
2973
2974 snaplist_destroy(&pa.shared_snaps, B_TRUE);
2975 snaplist_destroy(&pa.clone_snaps, B_FALSE);
2976 snaplist_destroy(&pa.origin_snaps, B_FALSE);
2977 if (pa.origin_origin)
2978 dsl_dataset_disown(pa.origin_origin, FTAG);
2979 dsl_dataset_rele(ds, FTAG);
2980 return (err);
2981 }
2982
2983 struct cloneswaparg {
2984 dsl_dataset_t *cds; /* clone dataset */
2985 dsl_dataset_t *ohds; /* origin's head dataset */
2986 boolean_t force;
2987 int64_t unused_refres_delta; /* change in unconsumed refreservation */
2988 };
2989
2990 /* ARGSUSED */
2991 static int
2992 dsl_dataset_clone_swap_check(void *arg1, void *arg2, dmu_tx_t *tx)
2993 {
2994 struct cloneswaparg *csa = arg1;
2995
2996 /* they should both be heads */
2997 if (dsl_dataset_is_snapshot(csa->cds) ||
2998 dsl_dataset_is_snapshot(csa->ohds))
2999 return (EINVAL);
3000
3001 /* the branch point should be just before them */
3002 if (csa->cds->ds_prev != csa->ohds->ds_prev)
3003 return (EINVAL);
3004
3005 /* cds should be the clone */
3006 if (csa->cds->ds_prev->ds_phys->ds_next_snap_obj !=
3007 csa->ohds->ds_object)
3008 return (EINVAL);
3009
3010 /* the clone should be a child of the origin */
3011 if (csa->cds->ds_dir->dd_parent != csa->ohds->ds_dir)
3012 return (EINVAL);
3013
3014 /* ohds shouldn't be modified unless 'force' */
3015 if (!csa->force && dsl_dataset_modified_since_lastsnap(csa->ohds))
3016 return (ETXTBSY);
3017
3018 /* adjust amount of any unconsumed refreservation */
3019 csa->unused_refres_delta =
3020 (int64_t)MIN(csa->ohds->ds_reserved,
3021 csa->ohds->ds_phys->ds_unique_bytes) -
3022 (int64_t)MIN(csa->ohds->ds_reserved,
3023 csa->cds->ds_phys->ds_unique_bytes);
3024
3025 if (csa->unused_refres_delta > 0 &&
3026 csa->unused_refres_delta >
3027 dsl_dir_space_available(csa->ohds->ds_dir, NULL, 0, TRUE))
3028 return (ENOSPC);
3029
3030 return (0);
3031 }
3032
3033 /* ARGSUSED */
3034 static void
3035 dsl_dataset_clone_swap_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
3036 {
3037 struct cloneswaparg *csa = arg1;
3038 dsl_pool_t *dp = csa->cds->ds_dir->dd_pool;
3039
3040 ASSERT(csa->cds->ds_reserved == 0);
3041 ASSERT(csa->cds->ds_quota == csa->ohds->ds_quota);
3042
3043 dmu_buf_will_dirty(csa->cds->ds_dbuf, tx);
3044 dmu_buf_will_dirty(csa->ohds->ds_dbuf, tx);
3045 dmu_buf_will_dirty(csa->cds->ds_prev->ds_dbuf, tx);
3046
3047 if (csa->cds->ds_user_ptr != NULL) {
3048 csa->cds->ds_user_evict_func(csa->cds, csa->cds->ds_user_ptr);
3049 csa->cds->ds_user_ptr = NULL;
3050 }
3051
3052 if (csa->ohds->ds_user_ptr != NULL) {
3053 csa->ohds->ds_user_evict_func(csa->ohds,
3054 csa->ohds->ds_user_ptr);
3055 csa->ohds->ds_user_ptr = NULL;
3056 }
3057
3058 /* reset origin's unique bytes */
3059 VERIFY(0 == bplist_space_birthrange(&csa->cds->ds_deadlist,
3060 csa->cds->ds_prev->ds_phys->ds_prev_snap_txg, UINT64_MAX,
3061 &csa->cds->ds_prev->ds_phys->ds_unique_bytes));
3062
3063 /* swap blkptrs */
3064 {
3065 blkptr_t tmp;
3066 tmp = csa->ohds->ds_phys->ds_bp;
3067 csa->ohds->ds_phys->ds_bp = csa->cds->ds_phys->ds_bp;
3068 csa->cds->ds_phys->ds_bp = tmp;
3069 }
3070
3071 /* set dd_*_bytes */
3072 {
3073 int64_t dused, dcomp, duncomp;
3074 uint64_t cdl_used, cdl_comp, cdl_uncomp;
3075 uint64_t odl_used, odl_comp, odl_uncomp;
3076
3077 ASSERT3U(csa->cds->ds_dir->dd_phys->
3078 dd_used_breakdown[DD_USED_SNAP], ==, 0);
3079
3080 VERIFY(0 == bplist_space(&csa->cds->ds_deadlist, &cdl_used,
3081 &cdl_comp, &cdl_uncomp));
3082 VERIFY(0 == bplist_space(&csa->ohds->ds_deadlist, &odl_used,
3083 &odl_comp, &odl_uncomp));
3084
3085 dused = csa->cds->ds_phys->ds_used_bytes + cdl_used -
3086 (csa->ohds->ds_phys->ds_used_bytes + odl_used);
3087 dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp -
3088 (csa->ohds->ds_phys->ds_compressed_bytes + odl_comp);
3089 duncomp = csa->cds->ds_phys->ds_uncompressed_bytes +
3090 cdl_uncomp -
3091 (csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp);
3092
3093 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD,
3094 dused, dcomp, duncomp, tx);
3095 dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD,
3096 -dused, -dcomp, -duncomp, tx);
3097
3098 /*
3099 * The difference in the space used by snapshots is the
3100 * difference in snapshot space due to the head's
3101 * deadlist (since that's the only thing that's
3102 * changing that affects the snapused).
3103 */
3104 VERIFY(0 == bplist_space_birthrange(&csa->cds->ds_deadlist,
3105 csa->ohds->ds_origin_txg, UINT64_MAX, &cdl_used));
3106 VERIFY(0 == bplist_space_birthrange(&csa->ohds->ds_deadlist,
3107 csa->ohds->ds_origin_txg, UINT64_MAX, &odl_used));
3108 dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used,
3109 DD_USED_HEAD, DD_USED_SNAP, tx);
3110 }
3111
3112 #define SWITCH64(x, y) \
3113 { \
3114 uint64_t __tmp = (x); \
3115 (x) = (y); \
3116 (y) = __tmp; \
3117 }
3118
3119 /* swap ds_*_bytes */
3120 SWITCH64(csa->ohds->ds_phys->ds_used_bytes,
3121 csa->cds->ds_phys->ds_used_bytes);
3122 SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes,
3123 csa->cds->ds_phys->ds_compressed_bytes);
3124 SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes,
3125 csa->cds->ds_phys->ds_uncompressed_bytes);
3126 SWITCH64(csa->ohds->ds_phys->ds_unique_bytes,
3127 csa->cds->ds_phys->ds_unique_bytes);
3128
3129 /* apply any parent delta for change in unconsumed refreservation */
3130 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV,
3131 csa->unused_refres_delta, 0, 0, tx);
3132
3133 /* swap deadlists */
3134 bplist_close(&csa->cds->ds_deadlist);
3135 bplist_close(&csa->ohds->ds_deadlist);
3136 SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj,
3137 csa->cds->ds_phys->ds_deadlist_obj);
3138 VERIFY(0 == bplist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset,
3139 csa->cds->ds_phys->ds_deadlist_obj));
3140 VERIFY(0 == bplist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset,
3141 csa->ohds->ds_phys->ds_deadlist_obj));
3142
3143 dsl_pool_ds_clone_swapped(csa->ohds, csa->cds, tx);
3144 }
3145
3146 /*
3147 * Swap 'clone' with its origin head file system. Used at the end
3148 * of "online recv" to swizzle the file system to the new version.
3149 */
3150 int
3151 dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head,
3152 boolean_t force)
3153 {
3154 struct cloneswaparg csa;
3155 int error;
3156
3157 ASSERT(clone->ds_owner);
3158 ASSERT(origin_head->ds_owner);
3159 retry:
3160 /* Need exclusive access for the swap */
3161 rw_enter(&clone->ds_rwlock, RW_WRITER);
3162 if (!rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) {
3163 rw_exit(&clone->ds_rwlock);
3164 rw_enter(&origin_head->ds_rwlock, RW_WRITER);
3165 if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) {
3166 rw_exit(&origin_head->ds_rwlock);
3167 goto retry;
3168 }
3169 }
3170 csa.cds = clone;
3171 csa.ohds = origin_head;
3172 csa.force = force;
3173 error = dsl_sync_task_do(clone->ds_dir->dd_pool,
3174 dsl_dataset_clone_swap_check,
3175 dsl_dataset_clone_swap_sync, &csa, NULL, 9);
3176 return (error);
3177 }
3178
3179 /*
3180 * Given a pool name and a dataset object number in that pool,
3181 * return the name of that dataset.
3182 */
3183 int
3184 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf)
3185 {
3186 spa_t *spa;
3187 dsl_pool_t *dp;
3188 dsl_dataset_t *ds;
3189 int error;
3190
3191 if ((error = spa_open(pname, &spa, FTAG)) != 0)
3192 return (error);
3193 dp = spa_get_dsl(spa);
3194 rw_enter(&dp->dp_config_rwlock, RW_READER);
3195 if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) {
3196 dsl_dataset_name(ds, buf);
3197 dsl_dataset_rele(ds, FTAG);
3198 }
3199 rw_exit(&dp->dp_config_rwlock);
3200 spa_close(spa, FTAG);
3201
3202 return (error);
3203 }
3204
3205 int
3206 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota,
3207 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv)
3208 {
3209 int error = 0;
3210
3211 ASSERT3S(asize, >, 0);
3212
3213 /*
3214 * *ref_rsrv is the portion of asize that will come from any
3215 * unconsumed refreservation space.
3216 */
3217 *ref_rsrv = 0;
3218
3219 mutex_enter(&ds->ds_lock);
3220 /*
3221 * Make a space adjustment for reserved bytes.
3222 */
3223 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) {
3224 ASSERT3U(*used, >=,
3225 ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
3226 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
3227 *ref_rsrv =
3228 asize - MIN(asize, parent_delta(ds, asize + inflight));
3229 }
3230
3231 if (!check_quota || ds->ds_quota == 0) {
3232 mutex_exit(&ds->ds_lock);
3233 return (0);
3234 }
3235 /*
3236 * If they are requesting more space, and our current estimate
3237 * is over quota, they get to try again unless the actual
3238 * on-disk is over quota and there are no pending changes (which
3239 * may free up space for us).
3240 */
3241 if (ds->ds_phys->ds_used_bytes + inflight >= ds->ds_quota) {
3242 if (inflight > 0 || ds->ds_phys->ds_used_bytes < ds->ds_quota)
3243 error = ERESTART;
3244 else
3245 error = EDQUOT;
3246 }
3247 mutex_exit(&ds->ds_lock);
3248
3249 return (error);
3250 }
3251
3252 /* ARGSUSED */
3253 static int
3254 dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx)
3255 {
3256 dsl_dataset_t *ds = arg1;
3257 uint64_t *quotap = arg2;
3258 uint64_t new_quota = *quotap;
3259
3260 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA)
3261 return (ENOTSUP);
3262
3263 if (new_quota == 0)
3264 return (0);
3265
3266 if (new_quota < ds->ds_phys->ds_used_bytes ||
3267 new_quota < ds->ds_reserved)
3268 return (ENOSPC);
3269
3270 return (0);
3271 }
3272
3273 /* ARGSUSED */
3274 void
3275 dsl_dataset_set_quota_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
3276 {
3277 dsl_dataset_t *ds = arg1;
3278 uint64_t *quotap = arg2;
3279 uint64_t new_quota = *quotap;
3280
3281 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3282
3283 ds->ds_quota = new_quota;
3284
3285 dsl_dir_prop_set_uint64_sync(ds->ds_dir, "refquota", new_quota, cr, tx);
3286
3287 spa_history_internal_log(LOG_DS_REFQUOTA, ds->ds_dir->dd_pool->dp_spa,
3288 tx, cr, "%lld dataset = %llu ",
3289 (longlong_t)new_quota, ds->ds_object);
3290 }
3291
3292 int
3293 dsl_dataset_set_quota(const char *dsname, uint64_t quota)
3294 {
3295 dsl_dataset_t *ds;
3296 int err;
3297
3298 err = dsl_dataset_hold(dsname, FTAG, &ds);
3299 if (err)
3300 return (err);
3301
3302 if (quota != ds->ds_quota) {
3303 /*
3304 * If someone removes a file, then tries to set the quota, we
3305 * want to make sure the file freeing takes effect.
3306 */
3307 txg_wait_open(ds->ds_dir->dd_pool, 0);
3308
3309 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
3310 dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync,
3311 ds, &quota, 0);
3312 }
3313 dsl_dataset_rele(ds, FTAG);
3314 return (err);
3315 }
3316
3317 static int
3318 dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx)
3319 {
3320 dsl_dataset_t *ds = arg1;
3321 uint64_t *reservationp = arg2;
3322 uint64_t new_reservation = *reservationp;
3323 uint64_t unique;
3324
3325 if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
3326 SPA_VERSION_REFRESERVATION)
3327 return (ENOTSUP);
3328
3329 if (dsl_dataset_is_snapshot(ds))
3330 return (EINVAL);
3331
3332 /*
3333 * If we are doing the preliminary check in open context, the
3334 * space estimates may be inaccurate.
3335 */
3336 if (!dmu_tx_is_syncing(tx))
3337 return (0);
3338
3339 mutex_enter(&ds->ds_lock);
3340 unique = dsl_dataset_unique(ds);
3341 mutex_exit(&ds->ds_lock);
3342
3343 if (MAX(unique, new_reservation) > MAX(unique, ds->ds_reserved)) {
3344 uint64_t delta = MAX(unique, new_reservation) -
3345 MAX(unique, ds->ds_reserved);
3346
3347 if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
3348 return (ENOSPC);
3349 if (ds->ds_quota > 0 &&
3350 new_reservation > ds->ds_quota)
3351 return (ENOSPC);
3352 }
3353
3354 return (0);
3355 }
3356
3357 /* ARGSUSED */
3358 static void
3359 dsl_dataset_set_reservation_sync(void *arg1, void *arg2, cred_t *cr,
3360 dmu_tx_t *tx)
3361 {
3362 dsl_dataset_t *ds = arg1;
3363 uint64_t *reservationp = arg2;
3364 uint64_t new_reservation = *reservationp;
3365 uint64_t unique;
3366 int64_t delta;
3367
3368 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3369
3370 mutex_enter(&ds->ds_dir->dd_lock);
3371 mutex_enter(&ds->ds_lock);
3372 unique = dsl_dataset_unique(ds);
3373 delta = MAX(0, (int64_t)(new_reservation - unique)) -
3374 MAX(0, (int64_t)(ds->ds_reserved - unique));
3375 ds->ds_reserved = new_reservation;
3376 mutex_exit(&ds->ds_lock);
3377
3378 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx);
3379 mutex_exit(&ds->ds_dir->dd_lock);
3380 dsl_dir_prop_set_uint64_sync(ds->ds_dir, "refreservation",
3381 new_reservation, cr, tx);
3382
3383 spa_history_internal_log(LOG_DS_REFRESERV,
3384 ds->ds_dir->dd_pool->dp_spa, tx, cr, "%lld dataset = %llu",
3385 (longlong_t)new_reservation, ds->ds_object);
3386 }
3387
3388 int
3389 dsl_dataset_set_reservation(const char *dsname, uint64_t reservation)
3390 {
3391 dsl_dataset_t *ds;
3392 int err;
3393
3394 err = dsl_dataset_hold(dsname, FTAG, &ds);
3395 if (err)
3396 return (err);
3397
3398 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
3399 dsl_dataset_set_reservation_check,
3400 dsl_dataset_set_reservation_sync, ds, &reservation, 0);
3401 dsl_dataset_rele(ds, FTAG);
3402 return (err);
3403 }
3404
3405 static int
3406 dsl_dataset_user_hold_check(void *arg1, void *arg2, dmu_tx_t *tx)
3407 {
3408 dsl_dataset_t *ds = arg1;
3409 char *htag = arg2;
3410 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3411 int error = 0;
3412
3413 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS)
3414 return (ENOTSUP);
3415
3416 if (!dsl_dataset_is_snapshot(ds))
3417 return (EINVAL);
3418
3419 if (strlen(htag) >= ZAP_MAXNAMELEN)
3420 return (ENAMETOOLONG);
3421
3422 /* tags must be unique */
3423 mutex_enter(&ds->ds_lock);
3424 if (ds->ds_phys->ds_userrefs_obj) {
3425 error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj, htag,
3426 8, 1, tx);
3427 if (error == 0)
3428 error = EEXIST;
3429 else if (error == ENOENT)
3430 error = 0;
3431 }
3432 mutex_exit(&ds->ds_lock);
3433
3434 return (error);
3435 }
3436
3437 static void
3438 dsl_dataset_user_hold_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
3439 {
3440 dsl_dataset_t *ds = arg1;
3441 char *htag = arg2;
3442 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3443 time_t now = gethrestime_sec();
3444 uint64_t zapobj;
3445
3446 mutex_enter(&ds->ds_lock);
3447 if (ds->ds_phys->ds_userrefs_obj == 0) {
3448 /*
3449 * This is the first user hold for this dataset. Create
3450 * the userrefs zap object.
3451 */
3452 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3453 zapobj = ds->ds_phys->ds_userrefs_obj =
3454 zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx);
3455 } else {
3456 zapobj = ds->ds_phys->ds_userrefs_obj;
3457 }
3458 ds->ds_userrefs++;
3459 mutex_exit(&ds->ds_lock);
3460
3461 VERIFY(0 == zap_add(mos, zapobj, htag, 8, 1, &now, tx));
3462
3463 spa_history_internal_log(LOG_DS_USER_HOLD,
3464 ds->ds_dir->dd_pool->dp_spa, tx, cr, "<%s> dataset = %llu",
3465 htag, ds->ds_object);
3466 }
3467
3468 struct dsl_ds_holdarg {
3469 dsl_sync_task_group_t *dstg;
3470 char *htag;
3471 char *snapname;
3472 boolean_t recursive;
3473 char failed[MAXPATHLEN];
3474 };
3475
3476 static int
3477 dsl_dataset_user_hold_one(char *dsname, void *arg)
3478 {
3479 struct dsl_ds_holdarg *ha = arg;
3480 dsl_dataset_t *ds;
3481 int error;
3482 char *name;
3483 size_t buflen;
3484
3485 /* alloc a buffer to hold dsname@snapname plus terminating NULL */
3486 buflen = strlen(dsname) + strlen(ha->snapname) + 2;
3487 name = kmem_alloc(buflen, KM_SLEEP);
3488 (void) snprintf(name, buflen, "%s@%s", dsname, ha->snapname);
3489 error = dsl_dataset_hold(name, ha->dstg, &ds);
3490 kmem_free(name, buflen);
3491 if (error == 0) {
3492 dsl_sync_task_create(ha->dstg, dsl_dataset_user_hold_check,
3493 dsl_dataset_user_hold_sync, ds, ha->htag, 0);
3494 } else if (error == ENOENT && ha->recursive) {
3495 error = 0;
3496 } else {
3497 (void) strcpy(ha->failed, dsname);
3498 }
3499 return (error);
3500 }
3501
3502 int
3503 dsl_dataset_user_hold(char *dsname, char *snapname, char *htag,
3504 boolean_t recursive)
3505 {
3506 struct dsl_ds_holdarg *ha;
3507 dsl_sync_task_t *dst;
3508 spa_t *spa;
3509 int error;
3510
3511 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3512
3513 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3514
3515 error = spa_open(dsname, &spa, FTAG);
3516 if (error) {
3517 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3518 return (error);
3519 }
3520
3521 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
3522 ha->htag = htag;
3523 ha->snapname = snapname;
3524 ha->recursive = recursive;
3525 if (recursive) {
3526 error = dmu_objset_find(dsname, dsl_dataset_user_hold_one,
3527 ha, DS_FIND_CHILDREN);
3528 } else {
3529 error = dsl_dataset_user_hold_one(dsname, ha);
3530 }
3531 if (error == 0)
3532 error = dsl_sync_task_group_wait(ha->dstg);
3533
3534 for (dst = list_head(&ha->dstg->dstg_tasks); dst;
3535 dst = list_next(&ha->dstg->dstg_tasks, dst)) {
3536 dsl_dataset_t *ds = dst->dst_arg1;
3537
3538 if (dst->dst_err) {
3539 dsl_dataset_name(ds, ha->failed);
3540 *strchr(ha->failed, '@') = '\0';
3541 }
3542 dsl_dataset_rele(ds, ha->dstg);
3543 }
3544
3545 if (error)
3546 (void) strcpy(dsname, ha->failed);
3547
3548 dsl_sync_task_group_destroy(ha->dstg);
3549 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3550 spa_close(spa, FTAG);
3551 return (error);
3552 }
3553
3554 struct dsl_ds_releasearg {
3555 dsl_dataset_t *ds;
3556 const char *htag;
3557 boolean_t own; /* do we own or just hold ds? */
3558 };
3559
3560 static int
3561 dsl_dataset_release_might_destroy(dsl_dataset_t *ds, const char *htag,
3562 boolean_t *might_destroy)
3563 {
3564 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3565 uint64_t zapobj;
3566 uint64_t tmp;
3567 int error;
3568
3569 *might_destroy = B_FALSE;
3570
3571 mutex_enter(&ds->ds_lock);
3572 zapobj = ds->ds_phys->ds_userrefs_obj;
3573 if (zapobj == 0) {
3574 /* The tag can't possibly exist */
3575 mutex_exit(&ds->ds_lock);
3576 return (ESRCH);
3577 }
3578
3579 /* Make sure the tag exists */
3580 error = zap_lookup(mos, zapobj, htag, 8, 1, &tmp);
3581 if (error) {
3582 mutex_exit(&ds->ds_lock);
3583 if (error == ENOENT)
3584 error = ESRCH;
3585 return (error);
3586 }
3587
3588 if (ds->ds_userrefs == 1 && ds->ds_phys->ds_num_children == 1 &&
3589 DS_IS_DEFER_DESTROY(ds))
3590 *might_destroy = B_TRUE;
3591
3592 mutex_exit(&ds->ds_lock);
3593 return (0);
3594 }
3595
3596 static int
3597 dsl_dataset_user_release_check(void *arg1, void *tag, dmu_tx_t *tx)
3598 {
3599 struct dsl_ds_releasearg *ra = arg1;
3600 dsl_dataset_t *ds = ra->ds;
3601 boolean_t might_destroy;
3602 int error;
3603
3604 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS)
3605 return (ENOTSUP);
3606
3607 error = dsl_dataset_release_might_destroy(ds, ra->htag, &might_destroy);
3608 if (error)
3609 return (error);
3610
3611 if (might_destroy) {
3612 struct dsl_ds_destroyarg dsda = {0};
3613
3614 if (dmu_tx_is_syncing(tx)) {
3615 /*
3616 * If we're not prepared to remove the snapshot,
3617 * we can't allow the release to happen right now.
3618 */
3619 if (!ra->own)
3620 return (EBUSY);
3621 if (ds->ds_user_ptr) {
3622 ds->ds_user_evict_func(ds, ds->ds_user_ptr);
3623 ds->ds_user_ptr = NULL;
3624 }
3625 }
3626 dsda.ds = ds;
3627 dsda.releasing = B_TRUE;
3628 return (dsl_dataset_destroy_check(&dsda, tag, tx));
3629 }
3630
3631 return (0);
3632 }
3633
3634 static void
3635 dsl_dataset_user_release_sync(void *arg1, void *tag, cred_t *cr, dmu_tx_t *tx)
3636 {
3637 struct dsl_ds_releasearg *ra = arg1;
3638 dsl_dataset_t *ds = ra->ds;
3639 spa_t *spa = ds->ds_dir->dd_pool->dp_spa;
3640 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3641 uint64_t zapobj;
3642 uint64_t dsobj = ds->ds_object;
3643 uint64_t refs;
3644
3645 mutex_enter(&ds->ds_lock);
3646 ds->ds_userrefs--;
3647 refs = ds->ds_userrefs;
3648 mutex_exit(&ds->ds_lock);
3649 zapobj = ds->ds_phys->ds_userrefs_obj;
3650 VERIFY(0 == zap_remove(mos, zapobj, ra->htag, tx));
3651 if (ds->ds_userrefs == 0 && ds->ds_phys->ds_num_children == 1 &&
3652 DS_IS_DEFER_DESTROY(ds)) {
3653 struct dsl_ds_destroyarg dsda = {0};
3654
3655 ASSERT(ra->own);
3656 dsda.ds = ds;
3657 dsda.releasing = B_TRUE;
3658 /* We already did the destroy_check */
3659 dsl_dataset_destroy_sync(&dsda, tag, cr, tx);
3660 }
3661
3662 spa_history_internal_log(LOG_DS_USER_RELEASE,
3663 spa, tx, cr, "<%s> %lld dataset = %llu",
3664 ra->htag, (longlong_t)refs, dsobj);
3665 }
3666
3667 static int
3668 dsl_dataset_user_release_one(char *dsname, void *arg)
3669 {
3670 struct dsl_ds_holdarg *ha = arg;
3671 struct dsl_ds_releasearg *ra;
3672 dsl_dataset_t *ds;
3673 int error;
3674 void *dtag = ha->dstg;
3675 char *name;
3676 size_t buflen;
3677 boolean_t own = B_FALSE;
3678 boolean_t might_destroy;
3679
3680 if (strlen(ha->htag) >= ZAP_MAXNAMELEN)
3681 return (ENAMETOOLONG);
3682
3683 /* alloc a buffer to hold dsname@snapname, plus the terminating NULL */
3684 buflen = strlen(dsname) + strlen(ha->snapname) + 2;
3685 name = kmem_alloc(buflen, KM_SLEEP);
3686 (void) snprintf(name, buflen, "%s@%s", dsname, ha->snapname);
3687 error = dsl_dataset_hold(name, dtag, &ds);
3688 kmem_free(name, buflen);
3689 if (error == ENOENT && ha->recursive)
3690 return (0);
3691 (void) strcpy(ha->failed, dsname);
3692 if (error)
3693 return (error);
3694
3695 ASSERT(dsl_dataset_is_snapshot(ds));
3696
3697 error = dsl_dataset_release_might_destroy(ds, ha->htag, &might_destroy);
3698 if (error) {
3699 dsl_dataset_rele(ds, dtag);
3700 return (error);
3701 }
3702
3703 if (might_destroy) {
3704 #ifdef _KERNEL
3705 error = zfs_unmount_snap(name, NULL);
3706 if (error) {
3707 dsl_dataset_rele(ds, dtag);
3708 return (error);
3709 }
3710 error = dsl_dataset_zvol_cleanup(ds, name);
3711 if (error) {
3712 dsl_dataset_rele(ds, dtag);
3713 return (error);
3714 }
3715 #endif
3716 if (!dsl_dataset_tryown(ds,
3717 DS_MODE_READONLY | DS_MODE_INCONSISTENT, dtag)) {
3718 dsl_dataset_rele(ds, dtag);
3719 return (EBUSY);
3720 } else {
3721 own = B_TRUE;
3722 dsl_dataset_make_exclusive(ds, dtag);
3723 }
3724 }
3725
3726 ra = kmem_alloc(sizeof (struct dsl_ds_releasearg), KM_SLEEP);
3727 ra->ds = ds;
3728 ra->htag = ha->htag;
3729 ra->own = own;
3730 dsl_sync_task_create(ha->dstg, dsl_dataset_user_release_check,
3731 dsl_dataset_user_release_sync, ra, dtag, 0);
3732
3733 return (0);
3734 }
3735
3736 int
3737 dsl_dataset_user_release(char *dsname, char *snapname, char *htag,
3738 boolean_t recursive)
3739 {
3740 struct dsl_ds_holdarg *ha;
3741 dsl_sync_task_t *dst;
3742 spa_t *spa;
3743 int error;
3744
3745 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3746
3747 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3748
3749 error = spa_open(dsname, &spa, FTAG);
3750 if (error) {
3751 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3752 return (error);
3753 }
3754
3755 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
3756 ha->htag = htag;
3757 ha->snapname = snapname;
3758 ha->recursive = recursive;
3759 if (recursive) {
3760 error = dmu_objset_find(dsname, dsl_dataset_user_release_one,
3761 ha, DS_FIND_CHILDREN);
3762 } else {
3763 error = dsl_dataset_user_release_one(dsname, ha);
3764 }
3765 if (error == 0)
3766 error = dsl_sync_task_group_wait(ha->dstg);
3767
3768 for (dst = list_head(&ha->dstg->dstg_tasks); dst;
3769 dst = list_next(&ha->dstg->dstg_tasks, dst)) {
3770 struct dsl_ds_releasearg *ra = dst->dst_arg1;
3771 dsl_dataset_t *ds = ra->ds;
3772
3773 if (dst->dst_err)
3774 dsl_dataset_name(ds, ha->failed);
3775
3776 if (ra->own)
3777 dsl_dataset_disown(ds, ha->dstg);
3778 else
3779 dsl_dataset_rele(ds, ha->dstg);
3780
3781 kmem_free(ra, sizeof (struct dsl_ds_releasearg));
3782 }
3783
3784 if (error)
3785 (void) strcpy(dsname, ha->failed);
3786
3787 dsl_sync_task_group_destroy(ha->dstg);
3788 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3789 spa_close(spa, FTAG);
3790 return (error);
3791 }
3792
3793 int
3794 dsl_dataset_get_holds(const char *dsname, nvlist_t **nvp)
3795 {
3796 dsl_dataset_t *ds;
3797 int err;
3798
3799 err = dsl_dataset_hold(dsname, FTAG, &ds);
3800 if (err)
3801 return (err);
3802
3803 VERIFY(0 == nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP));
3804 if (ds->ds_phys->ds_userrefs_obj != 0) {
3805 zap_attribute_t *za;
3806 zap_cursor_t zc;
3807
3808 za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP);
3809 for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset,
3810 ds->ds_phys->ds_userrefs_obj);
3811 zap_cursor_retrieve(&zc, za) == 0;
3812 zap_cursor_advance(&zc)) {
3813 VERIFY(0 == nvlist_add_uint64(*nvp, za->za_name,
3814 za->za_first_integer));
3815 }
3816 zap_cursor_fini(&zc);
3817 kmem_free(za, sizeof (zap_attribute_t));
3818 }
3819 dsl_dataset_rele(ds, FTAG);
3820 return (0);
3821 }
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