1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2013 by Delphix. All rights reserved.
24 * Copyright (c) 2012, Joyent, Inc. All rights reserved.
25 */
26
27 #include <sys/dmu_objset.h>
28 #include <sys/dsl_dataset.h>
29 #include <sys/dsl_dir.h>
30 #include <sys/dsl_prop.h>
31 #include <sys/dsl_synctask.h>
32 #include <sys/dmu_traverse.h>
33 #include <sys/dmu_impl.h>
34 #include <sys/dmu_tx.h>
35 #include <sys/arc.h>
36 #include <sys/zio.h>
37 #include <sys/zap.h>
38 #include <sys/zfeature.h>
39 #include <sys/unique.h>
40 #include <sys/zfs_context.h>
41 #include <sys/zfs_ioctl.h>
42 #include <sys/spa.h>
43 #include <sys/zfs_znode.h>
44 #include <sys/zfs_onexit.h>
45 #include <sys/zvol.h>
46 #include <sys/dsl_scan.h>
47 #include <sys/dsl_deadlist.h>
48 #include <sys/dsl_destroy.h>
49 #include <sys/dsl_userhold.h>
50
51 #define SWITCH64(x, y) \
52 { \
53 uint64_t __tmp = (x); \
54 (x) = (y); \
55 (y) = __tmp; \
56 }
57
58 #define DS_REF_MAX (1ULL << 62)
59
60 #define DSL_DEADLIST_BLOCKSIZE SPA_MAXBLOCKSIZE
61
62 /*
63 * Figure out how much of this delta should be propogated to the dsl_dir
64 * layer. If there's a refreservation, that space has already been
65 * partially accounted for in our ancestors.
66 */
67 static int64_t
68 parent_delta(dsl_dataset_t *ds, int64_t delta)
69 {
70 uint64_t old_bytes, new_bytes;
71
72 if (ds->ds_reserved == 0)
73 return (delta);
74
75 old_bytes = MAX(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
76 new_bytes = MAX(ds->ds_phys->ds_unique_bytes + delta, ds->ds_reserved);
77
78 ASSERT3U(ABS((int64_t)(new_bytes - old_bytes)), <=, ABS(delta));
79 return (new_bytes - old_bytes);
80 }
81
82 void
83 dsl_dataset_block_born(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx)
84 {
85 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
86 int compressed = BP_GET_PSIZE(bp);
87 int uncompressed = BP_GET_UCSIZE(bp);
88 int64_t delta;
89
90 dprintf_bp(bp, "ds=%p", ds);
91
92 ASSERT(dmu_tx_is_syncing(tx));
93 /* It could have been compressed away to nothing */
94 if (BP_IS_HOLE(bp))
95 return;
96 ASSERT(BP_GET_TYPE(bp) != DMU_OT_NONE);
97 ASSERT(DMU_OT_IS_VALID(BP_GET_TYPE(bp)));
98 if (ds == NULL) {
99 dsl_pool_mos_diduse_space(tx->tx_pool,
100 used, compressed, uncompressed);
101 return;
102 }
103 dmu_buf_will_dirty(ds->ds_dbuf, tx);
104
105 mutex_enter(&ds->ds_dir->dd_lock);
106 mutex_enter(&ds->ds_lock);
107 delta = parent_delta(ds, used);
108 ds->ds_phys->ds_referenced_bytes += used;
109 ds->ds_phys->ds_compressed_bytes += compressed;
110 ds->ds_phys->ds_uncompressed_bytes += uncompressed;
111 ds->ds_phys->ds_unique_bytes += used;
112 mutex_exit(&ds->ds_lock);
113 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta,
114 compressed, uncompressed, tx);
115 dsl_dir_transfer_space(ds->ds_dir, used - delta,
116 DD_USED_REFRSRV, DD_USED_HEAD, tx);
117 mutex_exit(&ds->ds_dir->dd_lock);
118 }
119
120 int
121 dsl_dataset_block_kill(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx,
122 boolean_t async)
123 {
124 if (BP_IS_HOLE(bp))
125 return (0);
126
127 ASSERT(dmu_tx_is_syncing(tx));
128 ASSERT(bp->blk_birth <= tx->tx_txg);
129
130 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
131 int compressed = BP_GET_PSIZE(bp);
132 int uncompressed = BP_GET_UCSIZE(bp);
133
134 ASSERT(used > 0);
135 if (ds == NULL) {
136 dsl_free(tx->tx_pool, tx->tx_txg, bp);
137 dsl_pool_mos_diduse_space(tx->tx_pool,
138 -used, -compressed, -uncompressed);
139 return (used);
140 }
141 ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool);
142
143 ASSERT(!dsl_dataset_is_snapshot(ds));
144 dmu_buf_will_dirty(ds->ds_dbuf, tx);
145
146 if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) {
147 int64_t delta;
148
149 dprintf_bp(bp, "freeing ds=%llu", ds->ds_object);
150 dsl_free(tx->tx_pool, tx->tx_txg, bp);
151
152 mutex_enter(&ds->ds_dir->dd_lock);
153 mutex_enter(&ds->ds_lock);
154 ASSERT(ds->ds_phys->ds_unique_bytes >= used ||
155 !DS_UNIQUE_IS_ACCURATE(ds));
156 delta = parent_delta(ds, -used);
157 ds->ds_phys->ds_unique_bytes -= used;
158 mutex_exit(&ds->ds_lock);
159 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
160 delta, -compressed, -uncompressed, tx);
161 dsl_dir_transfer_space(ds->ds_dir, -used - delta,
162 DD_USED_REFRSRV, DD_USED_HEAD, tx);
163 mutex_exit(&ds->ds_dir->dd_lock);
164 } else {
165 dprintf_bp(bp, "putting on dead list: %s", "");
166 if (async) {
167 /*
168 * We are here as part of zio's write done callback,
169 * which means we're a zio interrupt thread. We can't
170 * call dsl_deadlist_insert() now because it may block
171 * waiting for I/O. Instead, put bp on the deferred
172 * queue and let dsl_pool_sync() finish the job.
173 */
174 bplist_append(&ds->ds_pending_deadlist, bp);
175 } else {
176 dsl_deadlist_insert(&ds->ds_deadlist, bp, tx);
177 }
178 ASSERT3U(ds->ds_prev->ds_object, ==,
179 ds->ds_phys->ds_prev_snap_obj);
180 ASSERT(ds->ds_prev->ds_phys->ds_num_children > 0);
181 /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */
182 if (ds->ds_prev->ds_phys->ds_next_snap_obj ==
183 ds->ds_object && bp->blk_birth >
184 ds->ds_prev->ds_phys->ds_prev_snap_txg) {
185 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
186 mutex_enter(&ds->ds_prev->ds_lock);
187 ds->ds_prev->ds_phys->ds_unique_bytes += used;
188 mutex_exit(&ds->ds_prev->ds_lock);
189 }
190 if (bp->blk_birth > ds->ds_dir->dd_origin_txg) {
191 dsl_dir_transfer_space(ds->ds_dir, used,
192 DD_USED_HEAD, DD_USED_SNAP, tx);
193 }
194 }
195 mutex_enter(&ds->ds_lock);
196 ASSERT3U(ds->ds_phys->ds_referenced_bytes, >=, used);
197 ds->ds_phys->ds_referenced_bytes -= used;
198 ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed);
199 ds->ds_phys->ds_compressed_bytes -= compressed;
200 ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed);
201 ds->ds_phys->ds_uncompressed_bytes -= uncompressed;
202 mutex_exit(&ds->ds_lock);
203
204 return (used);
205 }
206
207 uint64_t
208 dsl_dataset_prev_snap_txg(dsl_dataset_t *ds)
209 {
210 uint64_t trysnap = 0;
211
212 if (ds == NULL)
213 return (0);
214 /*
215 * The snapshot creation could fail, but that would cause an
216 * incorrect FALSE return, which would only result in an
217 * overestimation of the amount of space that an operation would
218 * consume, which is OK.
219 *
220 * There's also a small window where we could miss a pending
221 * snapshot, because we could set the sync task in the quiescing
222 * phase. So this should only be used as a guess.
223 */
224 if (ds->ds_trysnap_txg >
225 spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa))
226 trysnap = ds->ds_trysnap_txg;
227 return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap));
228 }
229
230 boolean_t
231 dsl_dataset_block_freeable(dsl_dataset_t *ds, const blkptr_t *bp,
232 uint64_t blk_birth)
233 {
234 if (blk_birth <= dsl_dataset_prev_snap_txg(ds))
235 return (B_FALSE);
236
237 ddt_prefetch(dsl_dataset_get_spa(ds), bp);
238
239 return (B_TRUE);
240 }
241
242 /* ARGSUSED */
243 static void
244 dsl_dataset_evict(dmu_buf_t *db, void *dsv)
245 {
246 dsl_dataset_t *ds = dsv;
247
248 ASSERT(ds->ds_owner == NULL);
249
250 unique_remove(ds->ds_fsid_guid);
251
252 if (ds->ds_objset != NULL)
253 dmu_objset_evict(ds->ds_objset);
254
255 if (ds->ds_prev) {
256 dsl_dataset_rele(ds->ds_prev, ds);
257 ds->ds_prev = NULL;
258 }
259
260 bplist_destroy(&ds->ds_pending_deadlist);
261 if (ds->ds_phys->ds_deadlist_obj != 0)
262 dsl_deadlist_close(&ds->ds_deadlist);
263 if (ds->ds_dir)
264 dsl_dir_rele(ds->ds_dir, ds);
265
266 ASSERT(!list_link_active(&ds->ds_synced_link));
267
268 mutex_destroy(&ds->ds_lock);
269 mutex_destroy(&ds->ds_opening_lock);
270 refcount_destroy(&ds->ds_longholds);
271
272 kmem_free(ds, sizeof (dsl_dataset_t));
273 }
274
275 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 != 0)
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 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 int
321 dsl_dataset_snap_remove(dsl_dataset_t *ds, const 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 dsl_dir_snap_cmtime_update(ds->ds_dir);
329
330 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
331 mt = MT_FIRST;
332 else
333 mt = MT_EXACT;
334
335 err = zap_remove_norm(mos, snapobj, name, mt, tx);
336 if (err == ENOTSUP && mt == MT_FIRST)
337 err = zap_remove(mos, snapobj, name, tx);
338 return (err);
339 }
340
341 int
342 dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag,
343 dsl_dataset_t **dsp)
344 {
345 objset_t *mos = dp->dp_meta_objset;
346 dmu_buf_t *dbuf;
347 dsl_dataset_t *ds;
348 int err;
349 dmu_object_info_t doi;
350
351 ASSERT(dsl_pool_config_held(dp));
352
353 err = dmu_bonus_hold(mos, dsobj, tag, &dbuf);
354 if (err != 0)
355 return (err);
356
357 /* Make sure dsobj has the correct object type. */
358 dmu_object_info_from_db(dbuf, &doi);
359 if (doi.doi_type != DMU_OT_DSL_DATASET)
360 return (SET_ERROR(EINVAL));
361
362 ds = dmu_buf_get_user(dbuf);
363 if (ds == NULL) {
364 dsl_dataset_t *winner = NULL;
365
366 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP);
367 ds->ds_dbuf = dbuf;
368 ds->ds_object = dsobj;
369 ds->ds_phys = dbuf->db_data;
370
371 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL);
372 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL);
373 mutex_init(&ds->ds_sendstream_lock, NULL, MUTEX_DEFAULT, NULL);
374 refcount_create(&ds->ds_longholds);
375
376 bplist_create(&ds->ds_pending_deadlist);
377 dsl_deadlist_open(&ds->ds_deadlist,
378 mos, ds->ds_phys->ds_deadlist_obj);
379
380 list_create(&ds->ds_sendstreams, sizeof (dmu_sendarg_t),
381 offsetof(dmu_sendarg_t, dsa_link));
382
383 if (err == 0) {
384 err = dsl_dir_hold_obj(dp,
385 ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir);
386 }
387 if (err != 0) {
388 mutex_destroy(&ds->ds_lock);
389 mutex_destroy(&ds->ds_opening_lock);
390 refcount_destroy(&ds->ds_longholds);
391 bplist_destroy(&ds->ds_pending_deadlist);
392 dsl_deadlist_close(&ds->ds_deadlist);
393 kmem_free(ds, sizeof (dsl_dataset_t));
394 dmu_buf_rele(dbuf, tag);
395 return (err);
396 }
397
398 if (!dsl_dataset_is_snapshot(ds)) {
399 ds->ds_snapname[0] = '\0';
400 if (ds->ds_phys->ds_prev_snap_obj != 0) {
401 err = dsl_dataset_hold_obj(dp,
402 ds->ds_phys->ds_prev_snap_obj,
403 ds, &ds->ds_prev);
404 }
405 } else {
406 if (zfs_flags & ZFS_DEBUG_SNAPNAMES)
407 err = dsl_dataset_get_snapname(ds);
408 if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) {
409 err = zap_count(
410 ds->ds_dir->dd_pool->dp_meta_objset,
411 ds->ds_phys->ds_userrefs_obj,
412 &ds->ds_userrefs);
413 }
414 }
415
416 if (err == 0 && !dsl_dataset_is_snapshot(ds)) {
417 err = dsl_prop_get_int_ds(ds,
418 zfs_prop_to_name(ZFS_PROP_REFRESERVATION),
419 &ds->ds_reserved);
420 if (err == 0) {
421 err = dsl_prop_get_int_ds(ds,
422 zfs_prop_to_name(ZFS_PROP_REFQUOTA),
423 &ds->ds_quota);
424 }
425 } else {
426 ds->ds_reserved = ds->ds_quota = 0;
427 }
428
429 if (err != 0 || (winner = dmu_buf_set_user_ie(dbuf, ds,
430 &ds->ds_phys, dsl_dataset_evict)) != NULL) {
431 bplist_destroy(&ds->ds_pending_deadlist);
432 dsl_deadlist_close(&ds->ds_deadlist);
433 if (ds->ds_prev)
434 dsl_dataset_rele(ds->ds_prev, ds);
435 dsl_dir_rele(ds->ds_dir, ds);
436 mutex_destroy(&ds->ds_lock);
437 mutex_destroy(&ds->ds_opening_lock);
438 refcount_destroy(&ds->ds_longholds);
439 kmem_free(ds, sizeof (dsl_dataset_t));
440 if (err != 0) {
441 dmu_buf_rele(dbuf, tag);
442 return (err);
443 }
444 ds = winner;
445 } else {
446 ds->ds_fsid_guid =
447 unique_insert(ds->ds_phys->ds_fsid_guid);
448 }
449 }
450 ASSERT3P(ds->ds_dbuf, ==, dbuf);
451 ASSERT3P(ds->ds_phys, ==, dbuf->db_data);
452 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 ||
453 spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN ||
454 dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap);
455 *dsp = ds;
456 return (0);
457 }
458
459 int
460 dsl_dataset_hold(dsl_pool_t *dp, const char *name,
461 void *tag, dsl_dataset_t **dsp)
462 {
463 dsl_dir_t *dd;
464 const char *snapname;
465 uint64_t obj;
466 int err = 0;
467
468 err = dsl_dir_hold(dp, name, FTAG, &dd, &snapname);
469 if (err != 0)
470 return (err);
471
472 ASSERT(dsl_pool_config_held(dp));
473 obj = dd->dd_phys->dd_head_dataset_obj;
474 if (obj != 0)
475 err = dsl_dataset_hold_obj(dp, obj, tag, dsp);
476 else
477 err = SET_ERROR(ENOENT);
478
479 /* we may be looking for a snapshot */
480 if (err == 0 && snapname != NULL) {
481 dsl_dataset_t *ds;
482
483 if (*snapname++ != '@') {
484 dsl_dataset_rele(*dsp, tag);
485 dsl_dir_rele(dd, FTAG);
486 return (SET_ERROR(ENOENT));
487 }
488
489 dprintf("looking for snapshot '%s'\n", snapname);
490 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj);
491 if (err == 0)
492 err = dsl_dataset_hold_obj(dp, obj, tag, &ds);
493 dsl_dataset_rele(*dsp, tag);
494
495 if (err == 0) {
496 mutex_enter(&ds->ds_lock);
497 if (ds->ds_snapname[0] == 0)
498 (void) strlcpy(ds->ds_snapname, snapname,
499 sizeof (ds->ds_snapname));
500 mutex_exit(&ds->ds_lock);
501 *dsp = ds;
502 }
503 }
504
505 dsl_dir_rele(dd, FTAG);
506 return (err);
507 }
508
509 int
510 dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj,
511 void *tag, dsl_dataset_t **dsp)
512 {
513 int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp);
514 if (err != 0)
515 return (err);
516 if (!dsl_dataset_tryown(*dsp, tag)) {
517 dsl_dataset_rele(*dsp, tag);
518 *dsp = NULL;
519 return (SET_ERROR(EBUSY));
520 }
521 return (0);
522 }
523
524 int
525 dsl_dataset_own(dsl_pool_t *dp, const char *name,
526 void *tag, dsl_dataset_t **dsp)
527 {
528 int err = dsl_dataset_hold(dp, name, tag, dsp);
529 if (err != 0)
530 return (err);
531 if (!dsl_dataset_tryown(*dsp, tag)) {
532 dsl_dataset_rele(*dsp, tag);
533 return (SET_ERROR(EBUSY));
534 }
535 return (0);
536 }
537
538 /*
539 * See the comment above dsl_pool_hold() for details. In summary, a long
540 * hold is used to prevent destruction of a dataset while the pool hold
541 * is dropped, allowing other concurrent operations (e.g. spa_sync()).
542 *
543 * The dataset and pool must be held when this function is called. After it
544 * is called, the pool hold may be released while the dataset is still held
545 * and accessed.
546 */
547 void
548 dsl_dataset_long_hold(dsl_dataset_t *ds, void *tag)
549 {
550 ASSERT(dsl_pool_config_held(ds->ds_dir->dd_pool));
551 (void) refcount_add(&ds->ds_longholds, tag);
552 }
553
554 void
555 dsl_dataset_long_rele(dsl_dataset_t *ds, void *tag)
556 {
557 (void) refcount_remove(&ds->ds_longholds, tag);
558 }
559
560 /* Return B_TRUE if there are any long holds on this dataset. */
561 boolean_t
562 dsl_dataset_long_held(dsl_dataset_t *ds)
563 {
564 return (!refcount_is_zero(&ds->ds_longholds));
565 }
566
567 void
568 dsl_dataset_name(dsl_dataset_t *ds, char *name)
569 {
570 if (ds == NULL) {
571 (void) strcpy(name, "mos");
572 } else {
573 dsl_dir_name(ds->ds_dir, name);
574 VERIFY0(dsl_dataset_get_snapname(ds));
575 if (ds->ds_snapname[0]) {
576 (void) strcat(name, "@");
577 /*
578 * We use a "recursive" mutex so that we
579 * can call dprintf_ds() with ds_lock held.
580 */
581 if (!MUTEX_HELD(&ds->ds_lock)) {
582 mutex_enter(&ds->ds_lock);
583 (void) strcat(name, ds->ds_snapname);
584 mutex_exit(&ds->ds_lock);
585 } else {
586 (void) strcat(name, ds->ds_snapname);
587 }
588 }
589 }
590 }
591
592 static int
593 dsl_dataset_namelen(dsl_dataset_t *ds)
594 {
595 int result;
596
597 if (ds == NULL) {
598 result = 3; /* "mos" */
599 } else {
600 result = dsl_dir_namelen(ds->ds_dir);
601 VERIFY0(dsl_dataset_get_snapname(ds));
602 if (ds->ds_snapname[0]) {
603 ++result; /* adding one for the @-sign */
604 if (!MUTEX_HELD(&ds->ds_lock)) {
605 mutex_enter(&ds->ds_lock);
606 result += strlen(ds->ds_snapname);
607 mutex_exit(&ds->ds_lock);
608 } else {
609 result += strlen(ds->ds_snapname);
610 }
611 }
612 }
613
614 return (result);
615 }
616
617 void
618 dsl_dataset_rele(dsl_dataset_t *ds, void *tag)
619 {
620 dmu_buf_rele(ds->ds_dbuf, tag);
621 }
622
623 void
624 dsl_dataset_disown(dsl_dataset_t *ds, void *tag)
625 {
626 ASSERT(ds->ds_owner == tag && ds->ds_dbuf != NULL);
627
628 mutex_enter(&ds->ds_lock);
629 ds->ds_owner = NULL;
630 mutex_exit(&ds->ds_lock);
631 dsl_dataset_long_rele(ds, tag);
632 if (ds->ds_dbuf != NULL)
633 dsl_dataset_rele(ds, tag);
634 else
635 dsl_dataset_evict(NULL, ds);
636 }
637
638 boolean_t
639 dsl_dataset_tryown(dsl_dataset_t *ds, void *tag)
640 {
641 boolean_t gotit = FALSE;
642
643 mutex_enter(&ds->ds_lock);
644 if (ds->ds_owner == NULL && !DS_IS_INCONSISTENT(ds)) {
645 ds->ds_owner = tag;
646 dsl_dataset_long_hold(ds, tag);
647 gotit = TRUE;
648 }
649 mutex_exit(&ds->ds_lock);
650 return (gotit);
651 }
652
653 uint64_t
654 dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin,
655 uint64_t flags, dmu_tx_t *tx)
656 {
657 dsl_pool_t *dp = dd->dd_pool;
658 dmu_buf_t *dbuf;
659 dsl_dataset_phys_t *dsphys;
660 uint64_t dsobj;
661 objset_t *mos = dp->dp_meta_objset;
662
663 if (origin == NULL)
664 origin = dp->dp_origin_snap;
665
666 ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp);
667 ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0);
668 ASSERT(dmu_tx_is_syncing(tx));
669 ASSERT(dd->dd_phys->dd_head_dataset_obj == 0);
670
671 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
672 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
673 VERIFY0(dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
674 dmu_buf_will_dirty(dbuf, tx);
675 dsphys = dbuf->db_data;
676 bzero(dsphys, sizeof (dsl_dataset_phys_t));
677 dsphys->ds_dir_obj = dd->dd_object;
678 dsphys->ds_flags = flags;
679 dsphys->ds_fsid_guid = unique_create();
680 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
681 sizeof (dsphys->ds_guid));
682 dsphys->ds_snapnames_zapobj =
683 zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP,
684 DMU_OT_NONE, 0, tx);
685 dsphys->ds_creation_time = gethrestime_sec();
686 dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg;
687
688 if (origin == NULL) {
689 dsphys->ds_deadlist_obj = dsl_deadlist_alloc(mos, tx);
690 } else {
691 dsl_dataset_t *ohds; /* head of the origin snapshot */
692
693 dsphys->ds_prev_snap_obj = origin->ds_object;
694 dsphys->ds_prev_snap_txg =
695 origin->ds_phys->ds_creation_txg;
696 dsphys->ds_referenced_bytes =
697 origin->ds_phys->ds_referenced_bytes;
698 dsphys->ds_compressed_bytes =
699 origin->ds_phys->ds_compressed_bytes;
700 dsphys->ds_uncompressed_bytes =
701 origin->ds_phys->ds_uncompressed_bytes;
702 dsphys->ds_bp = origin->ds_phys->ds_bp;
703 dsphys->ds_flags |= origin->ds_phys->ds_flags;
704
705 dmu_buf_will_dirty(origin->ds_dbuf, tx);
706 origin->ds_phys->ds_num_children++;
707
708 VERIFY0(dsl_dataset_hold_obj(dp,
709 origin->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ohds));
710 dsphys->ds_deadlist_obj = dsl_deadlist_clone(&ohds->ds_deadlist,
711 dsphys->ds_prev_snap_txg, dsphys->ds_prev_snap_obj, tx);
712 dsl_dataset_rele(ohds, FTAG);
713
714 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) {
715 if (origin->ds_phys->ds_next_clones_obj == 0) {
716 origin->ds_phys->ds_next_clones_obj =
717 zap_create(mos,
718 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx);
719 }
720 VERIFY0(zap_add_int(mos,
721 origin->ds_phys->ds_next_clones_obj, dsobj, tx));
722 }
723
724 dmu_buf_will_dirty(dd->dd_dbuf, tx);
725 dd->dd_phys->dd_origin_obj = origin->ds_object;
726 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
727 if (origin->ds_dir->dd_phys->dd_clones == 0) {
728 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx);
729 origin->ds_dir->dd_phys->dd_clones =
730 zap_create(mos,
731 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
732 }
733 VERIFY0(zap_add_int(mos,
734 origin->ds_dir->dd_phys->dd_clones, dsobj, tx));
735 }
736 }
737
738 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
739 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
740
741 dmu_buf_rele(dbuf, FTAG);
742
743 dmu_buf_will_dirty(dd->dd_dbuf, tx);
744 dd->dd_phys->dd_head_dataset_obj = dsobj;
745
746 return (dsobj);
747 }
748
749 static void
750 dsl_dataset_zero_zil(dsl_dataset_t *ds, dmu_tx_t *tx)
751 {
752 objset_t *os;
753
754 VERIFY0(dmu_objset_from_ds(ds, &os));
755 bzero(&os->os_zil_header, sizeof (os->os_zil_header));
756 dsl_dataset_dirty(ds, tx);
757 }
758
759 uint64_t
760 dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname,
761 dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx)
762 {
763 dsl_pool_t *dp = pdd->dd_pool;
764 uint64_t dsobj, ddobj;
765 dsl_dir_t *dd;
766
767 ASSERT(dmu_tx_is_syncing(tx));
768 ASSERT(lastname[0] != '@');
769
770 ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx);
771 VERIFY0(dsl_dir_hold_obj(dp, ddobj, lastname, FTAG, &dd));
772
773 dsobj = dsl_dataset_create_sync_dd(dd, origin,
774 flags & ~DS_CREATE_FLAG_NODIRTY, tx);
775
776 dsl_deleg_set_create_perms(dd, tx, cr);
777
778 dsl_dir_rele(dd, FTAG);
779
780 /*
781 * If we are creating a clone, make sure we zero out any stale
782 * data from the origin snapshots zil header.
783 */
784 if (origin != NULL && !(flags & DS_CREATE_FLAG_NODIRTY)) {
785 dsl_dataset_t *ds;
786
787 VERIFY0(dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
788 dsl_dataset_zero_zil(ds, tx);
789 dsl_dataset_rele(ds, FTAG);
790 }
791
792 return (dsobj);
793 }
794
795 /*
796 * The unique space in the head dataset can be calculated by subtracting
797 * the space used in the most recent snapshot, that is still being used
798 * in this file system, from the space currently in use. To figure out
799 * the space in the most recent snapshot still in use, we need to take
800 * the total space used in the snapshot and subtract out the space that
801 * has been freed up since the snapshot was taken.
802 */
803 void
804 dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds)
805 {
806 uint64_t mrs_used;
807 uint64_t dlused, dlcomp, dluncomp;
808
809 ASSERT(!dsl_dataset_is_snapshot(ds));
810
811 if (ds->ds_phys->ds_prev_snap_obj != 0)
812 mrs_used = ds->ds_prev->ds_phys->ds_referenced_bytes;
813 else
814 mrs_used = 0;
815
816 dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp);
817
818 ASSERT3U(dlused, <=, mrs_used);
819 ds->ds_phys->ds_unique_bytes =
820 ds->ds_phys->ds_referenced_bytes - (mrs_used - dlused);
821
822 if (spa_version(ds->ds_dir->dd_pool->dp_spa) >=
823 SPA_VERSION_UNIQUE_ACCURATE)
824 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
825 }
826
827 void
828 dsl_dataset_remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj,
829 dmu_tx_t *tx)
830 {
831 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
832 uint64_t count;
833 int err;
834
835 ASSERT(ds->ds_phys->ds_num_children >= 2);
836 err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx);
837 /*
838 * The err should not be ENOENT, but a bug in a previous version
839 * of the code could cause upgrade_clones_cb() to not set
840 * ds_next_snap_obj when it should, leading to a missing entry.
841 * If we knew that the pool was created after
842 * SPA_VERSION_NEXT_CLONES, we could assert that it isn't
843 * ENOENT. However, at least we can check that we don't have
844 * too many entries in the next_clones_obj even after failing to
845 * remove this one.
846 */
847 if (err != ENOENT)
848 VERIFY0(err);
849 ASSERT0(zap_count(mos, ds->ds_phys->ds_next_clones_obj,
850 &count));
851 ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2);
852 }
853
854
855 blkptr_t *
856 dsl_dataset_get_blkptr(dsl_dataset_t *ds)
857 {
858 return (&ds->ds_phys->ds_bp);
859 }
860
861 void
862 dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx)
863 {
864 ASSERT(dmu_tx_is_syncing(tx));
865 /* If it's the meta-objset, set dp_meta_rootbp */
866 if (ds == NULL) {
867 tx->tx_pool->dp_meta_rootbp = *bp;
868 } else {
869 dmu_buf_will_dirty(ds->ds_dbuf, tx);
870 ds->ds_phys->ds_bp = *bp;
871 }
872 }
873
874 spa_t *
875 dsl_dataset_get_spa(dsl_dataset_t *ds)
876 {
877 return (ds->ds_dir->dd_pool->dp_spa);
878 }
879
880 void
881 dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx)
882 {
883 dsl_pool_t *dp;
884
885 if (ds == NULL) /* this is the meta-objset */
886 return;
887
888 ASSERT(ds->ds_objset != NULL);
889
890 if (ds->ds_phys->ds_next_snap_obj != 0)
891 panic("dirtying snapshot!");
892
893 dp = ds->ds_dir->dd_pool;
894
895 if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg)) {
896 /* up the hold count until we can be written out */
897 dmu_buf_add_ref(ds->ds_dbuf, ds);
898 }
899 }
900
901 boolean_t
902 dsl_dataset_is_dirty(dsl_dataset_t *ds)
903 {
904 for (int t = 0; t < TXG_SIZE; t++) {
905 if (txg_list_member(&ds->ds_dir->dd_pool->dp_dirty_datasets,
906 ds, t))
907 return (B_TRUE);
908 }
909 return (B_FALSE);
910 }
911
912 static int
913 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx)
914 {
915 uint64_t asize;
916
917 if (!dmu_tx_is_syncing(tx))
918 return (0);
919
920 /*
921 * If there's an fs-only reservation, any blocks that might become
922 * owned by the snapshot dataset must be accommodated by space
923 * outside of the reservation.
924 */
925 ASSERT(ds->ds_reserved == 0 || DS_UNIQUE_IS_ACCURATE(ds));
926 asize = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
927 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
928 return (SET_ERROR(ENOSPC));
929
930 /*
931 * Propagate any reserved space for this snapshot to other
932 * snapshot checks in this sync group.
933 */
934 if (asize > 0)
935 dsl_dir_willuse_space(ds->ds_dir, asize, tx);
936
937 return (0);
938 }
939
940 typedef struct dsl_dataset_snapshot_arg {
941 nvlist_t *ddsa_snaps;
942 nvlist_t *ddsa_props;
943 nvlist_t *ddsa_errors;
944 } dsl_dataset_snapshot_arg_t;
945
946 int
947 dsl_dataset_snapshot_check_impl(dsl_dataset_t *ds, const char *snapname,
948 dmu_tx_t *tx)
949 {
950 int error;
951 uint64_t value;
952
953 ds->ds_trysnap_txg = tx->tx_txg;
954
955 if (!dmu_tx_is_syncing(tx))
956 return (0);
957
958 /*
959 * We don't allow multiple snapshots of the same txg. If there
960 * is already one, try again.
961 */
962 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg)
963 return (SET_ERROR(EAGAIN));
964
965 /*
966 * Check for conflicting snapshot name.
967 */
968 error = dsl_dataset_snap_lookup(ds, snapname, &value);
969 if (error == 0)
970 return (SET_ERROR(EEXIST));
971 if (error != ENOENT)
972 return (error);
973
974 error = dsl_dataset_snapshot_reserve_space(ds, tx);
975 if (error != 0)
976 return (error);
977
978 return (0);
979 }
980
981 static int
982 dsl_dataset_snapshot_check(void *arg, dmu_tx_t *tx)
983 {
984 dsl_dataset_snapshot_arg_t *ddsa = arg;
985 dsl_pool_t *dp = dmu_tx_pool(tx);
986 nvpair_t *pair;
987 int rv = 0;
988
989 for (pair = nvlist_next_nvpair(ddsa->ddsa_snaps, NULL);
990 pair != NULL; pair = nvlist_next_nvpair(ddsa->ddsa_snaps, pair)) {
991 int error = 0;
992 dsl_dataset_t *ds;
993 char *name, *atp;
994 char dsname[MAXNAMELEN];
995
996 name = nvpair_name(pair);
997 if (strlen(name) >= MAXNAMELEN)
998 error = SET_ERROR(ENAMETOOLONG);
999 if (error == 0) {
1000 atp = strchr(name, '@');
1001 if (atp == NULL)
1002 error = SET_ERROR(EINVAL);
1003 if (error == 0)
1004 (void) strlcpy(dsname, name, atp - name + 1);
1005 }
1006 if (error == 0)
1007 error = dsl_dataset_hold(dp, dsname, FTAG, &ds);
1008 if (error == 0) {
1009 error = dsl_dataset_snapshot_check_impl(ds,
1010 atp + 1, tx);
1011 dsl_dataset_rele(ds, FTAG);
1012 }
1013
1014 if (error != 0) {
1015 if (ddsa->ddsa_errors != NULL) {
1016 fnvlist_add_int32(ddsa->ddsa_errors,
1017 name, error);
1018 }
1019 rv = error;
1020 }
1021 }
1022 return (rv);
1023 }
1024
1025 void
1026 dsl_dataset_snapshot_sync_impl(dsl_dataset_t *ds, const char *snapname,
1027 dmu_tx_t *tx)
1028 {
1029 static zil_header_t zero_zil;
1030
1031 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1032 dmu_buf_t *dbuf;
1033 dsl_dataset_phys_t *dsphys;
1034 uint64_t dsobj, crtxg;
1035 objset_t *mos = dp->dp_meta_objset;
1036 objset_t *os;
1037
1038 ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
1039
1040 /*
1041 * If we are on an old pool, the zil must not be active, in which
1042 * case it will be zeroed. Usually zil_suspend() accomplishes this.
1043 */
1044 ASSERT(spa_version(dmu_tx_pool(tx)->dp_spa) >= SPA_VERSION_FAST_SNAP ||
1045 dmu_objset_from_ds(ds, &os) != 0 ||
1046 bcmp(&os->os_phys->os_zil_header, &zero_zil,
1047 sizeof (zero_zil)) == 0);
1048
1049
1050 /*
1051 * The origin's ds_creation_txg has to be < TXG_INITIAL
1052 */
1053 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0)
1054 crtxg = 1;
1055 else
1056 crtxg = tx->tx_txg;
1057
1058 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
1059 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
1060 VERIFY0(dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
1061 dmu_buf_will_dirty(dbuf, tx);
1062 dsphys = dbuf->db_data;
1063 bzero(dsphys, sizeof (dsl_dataset_phys_t));
1064 dsphys->ds_dir_obj = ds->ds_dir->dd_object;
1065 dsphys->ds_fsid_guid = unique_create();
1066 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
1067 sizeof (dsphys->ds_guid));
1068 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj;
1069 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg;
1070 dsphys->ds_next_snap_obj = ds->ds_object;
1071 dsphys->ds_num_children = 1;
1072 dsphys->ds_creation_time = gethrestime_sec();
1073 dsphys->ds_creation_txg = crtxg;
1074 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj;
1075 dsphys->ds_referenced_bytes = ds->ds_phys->ds_referenced_bytes;
1076 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes;
1077 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes;
1078 dsphys->ds_flags = ds->ds_phys->ds_flags;
1079 dsphys->ds_bp = ds->ds_phys->ds_bp;
1080 dmu_buf_rele(dbuf, FTAG);
1081
1082 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0);
1083 if (ds->ds_prev) {
1084 uint64_t next_clones_obj =
1085 ds->ds_prev->ds_phys->ds_next_clones_obj;
1086 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj ==
1087 ds->ds_object ||
1088 ds->ds_prev->ds_phys->ds_num_children > 1);
1089 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) {
1090 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
1091 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
1092 ds->ds_prev->ds_phys->ds_creation_txg);
1093 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj;
1094 } else if (next_clones_obj != 0) {
1095 dsl_dataset_remove_from_next_clones(ds->ds_prev,
1096 dsphys->ds_next_snap_obj, tx);
1097 VERIFY0(zap_add_int(mos,
1098 next_clones_obj, dsobj, tx));
1099 }
1100 }
1101
1102 /*
1103 * If we have a reference-reservation on this dataset, we will
1104 * need to increase the amount of refreservation being charged
1105 * since our unique space is going to zero.
1106 */
1107 if (ds->ds_reserved) {
1108 int64_t delta;
1109 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
1110 delta = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
1111 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV,
1112 delta, 0, 0, tx);
1113 }
1114
1115 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1116 ds->ds_phys->ds_deadlist_obj = dsl_deadlist_clone(&ds->ds_deadlist,
1117 UINT64_MAX, ds->ds_phys->ds_prev_snap_obj, tx);
1118 dsl_deadlist_close(&ds->ds_deadlist);
1119 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj);
1120 dsl_deadlist_add_key(&ds->ds_deadlist,
1121 ds->ds_phys->ds_prev_snap_txg, tx);
1122
1123 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg);
1124 ds->ds_phys->ds_prev_snap_obj = dsobj;
1125 ds->ds_phys->ds_prev_snap_txg = crtxg;
1126 ds->ds_phys->ds_unique_bytes = 0;
1127 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
1128 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
1129
1130 VERIFY0(zap_add(mos, ds->ds_phys->ds_snapnames_zapobj,
1131 snapname, 8, 1, &dsobj, tx));
1132
1133 if (ds->ds_prev)
1134 dsl_dataset_rele(ds->ds_prev, ds);
1135 VERIFY0(dsl_dataset_hold_obj(dp,
1136 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev));
1137
1138 dsl_scan_ds_snapshotted(ds, tx);
1139
1140 dsl_dir_snap_cmtime_update(ds->ds_dir);
1141
1142 spa_history_log_internal_ds(ds->ds_prev, "snapshot", tx, "");
1143 }
1144
1145 static void
1146 dsl_dataset_snapshot_sync(void *arg, dmu_tx_t *tx)
1147 {
1148 dsl_dataset_snapshot_arg_t *ddsa = arg;
1149 dsl_pool_t *dp = dmu_tx_pool(tx);
1150 nvpair_t *pair;
1151
1152 for (pair = nvlist_next_nvpair(ddsa->ddsa_snaps, NULL);
1153 pair != NULL; pair = nvlist_next_nvpair(ddsa->ddsa_snaps, pair)) {
1154 dsl_dataset_t *ds;
1155 char *name, *atp;
1156 char dsname[MAXNAMELEN];
1157
1158 name = nvpair_name(pair);
1159 atp = strchr(name, '@');
1160 (void) strlcpy(dsname, name, atp - name + 1);
1161 VERIFY0(dsl_dataset_hold(dp, dsname, FTAG, &ds));
1162
1163 dsl_dataset_snapshot_sync_impl(ds, atp + 1, tx);
1164 if (ddsa->ddsa_props != NULL) {
1165 dsl_props_set_sync_impl(ds->ds_prev,
1166 ZPROP_SRC_LOCAL, ddsa->ddsa_props, tx);
1167 }
1168 dsl_dataset_rele(ds, FTAG);
1169 }
1170 }
1171
1172 /*
1173 * The snapshots must all be in the same pool.
1174 * All-or-nothing: if there are any failures, nothing will be modified.
1175 */
1176 int
1177 dsl_dataset_snapshot(nvlist_t *snaps, nvlist_t *props, nvlist_t *errors)
1178 {
1179 dsl_dataset_snapshot_arg_t ddsa;
1180 nvpair_t *pair;
1181 boolean_t needsuspend;
1182 int error;
1183 spa_t *spa;
1184 char *firstname;
1185 nvlist_t *suspended = NULL;
1186
1187 pair = nvlist_next_nvpair(snaps, NULL);
1188 if (pair == NULL)
1189 return (0);
1190 firstname = nvpair_name(pair);
1191
1192 error = spa_open(firstname, &spa, FTAG);
1193 if (error != 0)
1194 return (error);
1195 needsuspend = (spa_version(spa) < SPA_VERSION_FAST_SNAP);
1196 spa_close(spa, FTAG);
1197
1198 if (needsuspend) {
1199 suspended = fnvlist_alloc();
1200 for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL;
1201 pair = nvlist_next_nvpair(snaps, pair)) {
1202 char fsname[MAXNAMELEN];
1203 char *snapname = nvpair_name(pair);
1204 char *atp;
1205 void *cookie;
1206
1207 atp = strchr(snapname, '@');
1208 if (atp == NULL) {
1209 error = SET_ERROR(EINVAL);
1210 break;
1211 }
1212 (void) strlcpy(fsname, snapname, atp - snapname + 1);
1213
1214 error = zil_suspend(fsname, &cookie);
1215 if (error != 0)
1216 break;
1217 fnvlist_add_uint64(suspended, fsname,
1218 (uintptr_t)cookie);
1219 }
1220 }
1221
1222 ddsa.ddsa_snaps = snaps;
1223 ddsa.ddsa_props = props;
1224 ddsa.ddsa_errors = errors;
1225
1226 if (error == 0) {
1227 error = dsl_sync_task(firstname, dsl_dataset_snapshot_check,
1228 dsl_dataset_snapshot_sync, &ddsa,
1229 fnvlist_num_pairs(snaps) * 3);
1230 }
1231
1232 if (suspended != NULL) {
1233 for (pair = nvlist_next_nvpair(suspended, NULL); pair != NULL;
1234 pair = nvlist_next_nvpair(suspended, pair)) {
1235 zil_resume((void *)(uintptr_t)
1236 fnvpair_value_uint64(pair));
1237 }
1238 fnvlist_free(suspended);
1239 }
1240
1241 return (error);
1242 }
1243
1244 typedef struct dsl_dataset_snapshot_tmp_arg {
1245 const char *ddsta_fsname;
1246 const char *ddsta_snapname;
1247 minor_t ddsta_cleanup_minor;
1248 const char *ddsta_htag;
1249 } dsl_dataset_snapshot_tmp_arg_t;
1250
1251 static int
1252 dsl_dataset_snapshot_tmp_check(void *arg, dmu_tx_t *tx)
1253 {
1254 dsl_dataset_snapshot_tmp_arg_t *ddsta = arg;
1255 dsl_pool_t *dp = dmu_tx_pool(tx);
1256 dsl_dataset_t *ds;
1257 int error;
1258
1259 error = dsl_dataset_hold(dp, ddsta->ddsta_fsname, FTAG, &ds);
1260 if (error != 0)
1261 return (error);
1262
1263 error = dsl_dataset_snapshot_check_impl(ds, ddsta->ddsta_snapname, tx);
1264 if (error != 0) {
1265 dsl_dataset_rele(ds, FTAG);
1266 return (error);
1267 }
1268
1269 if (spa_version(dp->dp_spa) < SPA_VERSION_USERREFS) {
1270 dsl_dataset_rele(ds, FTAG);
1271 return (SET_ERROR(ENOTSUP));
1272 }
1273 error = dsl_dataset_user_hold_check_one(NULL, ddsta->ddsta_htag,
1274 B_TRUE, tx);
1275 if (error != 0) {
1276 dsl_dataset_rele(ds, FTAG);
1277 return (error);
1278 }
1279
1280 dsl_dataset_rele(ds, FTAG);
1281 return (0);
1282 }
1283
1284 static void
1285 dsl_dataset_snapshot_tmp_sync(void *arg, dmu_tx_t *tx)
1286 {
1287 dsl_dataset_snapshot_tmp_arg_t *ddsta = arg;
1288 dsl_pool_t *dp = dmu_tx_pool(tx);
1289 dsl_dataset_t *ds;
1290
1291 VERIFY0(dsl_dataset_hold(dp, ddsta->ddsta_fsname, FTAG, &ds));
1292
1293 dsl_dataset_snapshot_sync_impl(ds, ddsta->ddsta_snapname, tx);
1294 dsl_dataset_user_hold_sync_one(ds->ds_prev, ddsta->ddsta_htag,
1295 ddsta->ddsta_cleanup_minor, gethrestime_sec(), tx);
1296 dsl_destroy_snapshot_sync_impl(ds->ds_prev, B_TRUE, tx);
1297
1298 dsl_dataset_rele(ds, FTAG);
1299 }
1300
1301 int
1302 dsl_dataset_snapshot_tmp(const char *fsname, const char *snapname,
1303 minor_t cleanup_minor, const char *htag)
1304 {
1305 dsl_dataset_snapshot_tmp_arg_t ddsta;
1306 int error;
1307 spa_t *spa;
1308 boolean_t needsuspend;
1309 void *cookie;
1310
1311 ddsta.ddsta_fsname = fsname;
1312 ddsta.ddsta_snapname = snapname;
1313 ddsta.ddsta_cleanup_minor = cleanup_minor;
1314 ddsta.ddsta_htag = htag;
1315
1316 error = spa_open(fsname, &spa, FTAG);
1317 if (error != 0)
1318 return (error);
1319 needsuspend = (spa_version(spa) < SPA_VERSION_FAST_SNAP);
1320 spa_close(spa, FTAG);
1321
1322 if (needsuspend) {
1323 error = zil_suspend(fsname, &cookie);
1324 if (error != 0)
1325 return (error);
1326 }
1327
1328 error = dsl_sync_task(fsname, dsl_dataset_snapshot_tmp_check,
1329 dsl_dataset_snapshot_tmp_sync, &ddsta, 3);
1330
1331 if (needsuspend)
1332 zil_resume(cookie);
1333 return (error);
1334 }
1335
1336
1337 void
1338 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx)
1339 {
1340 ASSERT(dmu_tx_is_syncing(tx));
1341 ASSERT(ds->ds_objset != NULL);
1342 ASSERT(ds->ds_phys->ds_next_snap_obj == 0);
1343
1344 /*
1345 * in case we had to change ds_fsid_guid when we opened it,
1346 * sync it out now.
1347 */
1348 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1349 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid;
1350
1351 dmu_objset_sync(ds->ds_objset, zio, tx);
1352 }
1353
1354 static void
1355 get_clones_stat(dsl_dataset_t *ds, nvlist_t *nv)
1356 {
1357 uint64_t count = 0;
1358 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1359 zap_cursor_t zc;
1360 zap_attribute_t za;
1361 nvlist_t *propval = fnvlist_alloc();
1362 nvlist_t *val = fnvlist_alloc();
1363
1364 ASSERT(dsl_pool_config_held(ds->ds_dir->dd_pool));
1365
1366 /*
1367 * There may be missing entries in ds_next_clones_obj
1368 * due to a bug in a previous version of the code.
1369 * Only trust it if it has the right number of entries.
1370 */
1371 if (ds->ds_phys->ds_next_clones_obj != 0) {
1372 ASSERT0(zap_count(mos, ds->ds_phys->ds_next_clones_obj,
1373 &count));
1374 }
1375 if (count != ds->ds_phys->ds_num_children - 1)
1376 goto fail;
1377 for (zap_cursor_init(&zc, mos, ds->ds_phys->ds_next_clones_obj);
1378 zap_cursor_retrieve(&zc, &za) == 0;
1379 zap_cursor_advance(&zc)) {
1380 dsl_dataset_t *clone;
1381 char buf[ZFS_MAXNAMELEN];
1382 VERIFY0(dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
1383 za.za_first_integer, FTAG, &clone));
1384 dsl_dir_name(clone->ds_dir, buf);
1385 fnvlist_add_boolean(val, buf);
1386 dsl_dataset_rele(clone, FTAG);
1387 }
1388 zap_cursor_fini(&zc);
1389 fnvlist_add_nvlist(propval, ZPROP_VALUE, val);
1390 fnvlist_add_nvlist(nv, zfs_prop_to_name(ZFS_PROP_CLONES), propval);
1391 fail:
1392 nvlist_free(val);
1393 nvlist_free(propval);
1394 }
1395
1396 void
1397 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv)
1398 {
1399 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1400 uint64_t refd, avail, uobjs, aobjs, ratio;
1401
1402 ASSERT(dsl_pool_config_held(dp));
1403
1404 ratio = ds->ds_phys->ds_compressed_bytes == 0 ? 100 :
1405 (ds->ds_phys->ds_uncompressed_bytes * 100 /
1406 ds->ds_phys->ds_compressed_bytes);
1407
1408 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRATIO, ratio);
1409 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_LOGICALREFERENCED,
1410 ds->ds_phys->ds_uncompressed_bytes);
1411
1412 if (dsl_dataset_is_snapshot(ds)) {
1413 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, ratio);
1414 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED,
1415 ds->ds_phys->ds_unique_bytes);
1416 get_clones_stat(ds, nv);
1417 } else {
1418 dsl_dir_stats(ds->ds_dir, nv);
1419 }
1420
1421 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs);
1422 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail);
1423 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd);
1424
1425 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION,
1426 ds->ds_phys->ds_creation_time);
1427 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG,
1428 ds->ds_phys->ds_creation_txg);
1429 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA,
1430 ds->ds_quota);
1431 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION,
1432 ds->ds_reserved);
1433 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID,
1434 ds->ds_phys->ds_guid);
1435 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE,
1436 ds->ds_phys->ds_unique_bytes);
1437 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID,
1438 ds->ds_object);
1439 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS,
1440 ds->ds_userrefs);
1441 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY,
1442 DS_IS_DEFER_DESTROY(ds) ? 1 : 0);
1443
1444 if (ds->ds_phys->ds_prev_snap_obj != 0) {
1445 uint64_t written, comp, uncomp;
1446 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1447 dsl_dataset_t *prev;
1448
1449 int err = dsl_dataset_hold_obj(dp,
1450 ds->ds_phys->ds_prev_snap_obj, FTAG, &prev);
1451 if (err == 0) {
1452 err = dsl_dataset_space_written(prev, ds, &written,
1453 &comp, &uncomp);
1454 dsl_dataset_rele(prev, FTAG);
1455 if (err == 0) {
1456 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_WRITTEN,
1457 written);
1458 }
1459 }
1460 }
1461 }
1462
1463 void
1464 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat)
1465 {
1466 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1467 ASSERT(dsl_pool_config_held(dp));
1468
1469 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg;
1470 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT;
1471 stat->dds_guid = ds->ds_phys->ds_guid;
1472 stat->dds_origin[0] = '\0';
1473 if (dsl_dataset_is_snapshot(ds)) {
1474 stat->dds_is_snapshot = B_TRUE;
1475 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1;
1476 } else {
1477 stat->dds_is_snapshot = B_FALSE;
1478 stat->dds_num_clones = 0;
1479
1480 if (dsl_dir_is_clone(ds->ds_dir)) {
1481 dsl_dataset_t *ods;
1482
1483 VERIFY0(dsl_dataset_hold_obj(dp,
1484 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods));
1485 dsl_dataset_name(ods, stat->dds_origin);
1486 dsl_dataset_rele(ods, FTAG);
1487 }
1488 }
1489 }
1490
1491 uint64_t
1492 dsl_dataset_fsid_guid(dsl_dataset_t *ds)
1493 {
1494 return (ds->ds_fsid_guid);
1495 }
1496
1497 void
1498 dsl_dataset_space(dsl_dataset_t *ds,
1499 uint64_t *refdbytesp, uint64_t *availbytesp,
1500 uint64_t *usedobjsp, uint64_t *availobjsp)
1501 {
1502 *refdbytesp = ds->ds_phys->ds_referenced_bytes;
1503 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE);
1504 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes)
1505 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes;
1506 if (ds->ds_quota != 0) {
1507 /*
1508 * Adjust available bytes according to refquota
1509 */
1510 if (*refdbytesp < ds->ds_quota)
1511 *availbytesp = MIN(*availbytesp,
1512 ds->ds_quota - *refdbytesp);
1513 else
1514 *availbytesp = 0;
1515 }
1516 *usedobjsp = ds->ds_phys->ds_bp.blk_fill;
1517 *availobjsp = DN_MAX_OBJECT - *usedobjsp;
1518 }
1519
1520 boolean_t
1521 dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds)
1522 {
1523 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1524
1525 ASSERT(dsl_pool_config_held(dp));
1526 if (ds->ds_prev == NULL)
1527 return (B_FALSE);
1528 if (ds->ds_phys->ds_bp.blk_birth >
1529 ds->ds_prev->ds_phys->ds_creation_txg) {
1530 objset_t *os, *os_prev;
1531 /*
1532 * It may be that only the ZIL differs, because it was
1533 * reset in the head. Don't count that as being
1534 * modified.
1535 */
1536 if (dmu_objset_from_ds(ds, &os) != 0)
1537 return (B_TRUE);
1538 if (dmu_objset_from_ds(ds->ds_prev, &os_prev) != 0)
1539 return (B_TRUE);
1540 return (bcmp(&os->os_phys->os_meta_dnode,
1541 &os_prev->os_phys->os_meta_dnode,
1542 sizeof (os->os_phys->os_meta_dnode)) != 0);
1543 }
1544 return (B_FALSE);
1545 }
1546
1547 typedef struct dsl_dataset_rename_snapshot_arg {
1548 const char *ddrsa_fsname;
1549 const char *ddrsa_oldsnapname;
1550 const char *ddrsa_newsnapname;
1551 boolean_t ddrsa_recursive;
1552 dmu_tx_t *ddrsa_tx;
1553 } dsl_dataset_rename_snapshot_arg_t;
1554
1555 /* ARGSUSED */
1556 static int
1557 dsl_dataset_rename_snapshot_check_impl(dsl_pool_t *dp,
1558 dsl_dataset_t *hds, void *arg)
1559 {
1560 dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
1561 int error;
1562 uint64_t val;
1563
1564 error = dsl_dataset_snap_lookup(hds, ddrsa->ddrsa_oldsnapname, &val);
1565 if (error != 0) {
1566 /* ignore nonexistent snapshots */
1567 return (error == ENOENT ? 0 : error);
1568 }
1569
1570 /* new name should not exist */
1571 error = dsl_dataset_snap_lookup(hds, ddrsa->ddrsa_newsnapname, &val);
1572 if (error == 0)
1573 error = SET_ERROR(EEXIST);
1574 else if (error == ENOENT)
1575 error = 0;
1576
1577 /* dataset name + 1 for the "@" + the new snapshot name must fit */
1578 if (dsl_dir_namelen(hds->ds_dir) + 1 +
1579 strlen(ddrsa->ddrsa_newsnapname) >= MAXNAMELEN)
1580 error = SET_ERROR(ENAMETOOLONG);
1581
1582 return (error);
1583 }
1584
1585 static int
1586 dsl_dataset_rename_snapshot_check(void *arg, dmu_tx_t *tx)
1587 {
1588 dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
1589 dsl_pool_t *dp = dmu_tx_pool(tx);
1590 dsl_dataset_t *hds;
1591 int error;
1592
1593 error = dsl_dataset_hold(dp, ddrsa->ddrsa_fsname, FTAG, &hds);
1594 if (error != 0)
1595 return (error);
1596
1597 if (ddrsa->ddrsa_recursive) {
1598 error = dmu_objset_find_dp(dp, hds->ds_dir->dd_object,
1599 dsl_dataset_rename_snapshot_check_impl, ddrsa,
1600 DS_FIND_CHILDREN);
1601 } else {
1602 error = dsl_dataset_rename_snapshot_check_impl(dp, hds, ddrsa);
1603 }
1604 dsl_dataset_rele(hds, FTAG);
1605 return (error);
1606 }
1607
1608 static int
1609 dsl_dataset_rename_snapshot_sync_impl(dsl_pool_t *dp,
1610 dsl_dataset_t *hds, void *arg)
1611 {
1612 dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
1613 dsl_dataset_t *ds;
1614 uint64_t val;
1615 dmu_tx_t *tx = ddrsa->ddrsa_tx;
1616 int error;
1617
1618 error = dsl_dataset_snap_lookup(hds, ddrsa->ddrsa_oldsnapname, &val);
1619 ASSERT(error == 0 || error == ENOENT);
1620 if (error == ENOENT) {
1621 /* ignore nonexistent snapshots */
1622 return (0);
1623 }
1624
1625 VERIFY0(dsl_dataset_hold_obj(dp, val, FTAG, &ds));
1626
1627 /* log before we change the name */
1628 spa_history_log_internal_ds(ds, "rename", tx,
1629 "-> @%s", ddrsa->ddrsa_newsnapname);
1630
1631 VERIFY0(dsl_dataset_snap_remove(hds, ddrsa->ddrsa_oldsnapname, tx));
1632 mutex_enter(&ds->ds_lock);
1633 (void) strcpy(ds->ds_snapname, ddrsa->ddrsa_newsnapname);
1634 mutex_exit(&ds->ds_lock);
1635 VERIFY0(zap_add(dp->dp_meta_objset, hds->ds_phys->ds_snapnames_zapobj,
1636 ds->ds_snapname, 8, 1, &ds->ds_object, tx));
1637
1638 dsl_dataset_rele(ds, FTAG);
1639 return (0);
1640 }
1641
1642 static void
1643 dsl_dataset_rename_snapshot_sync(void *arg, dmu_tx_t *tx)
1644 {
1645 dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
1646 dsl_pool_t *dp = dmu_tx_pool(tx);
1647 dsl_dataset_t *hds;
1648
1649 VERIFY0(dsl_dataset_hold(dp, ddrsa->ddrsa_fsname, FTAG, &hds));
1650 ddrsa->ddrsa_tx = tx;
1651 if (ddrsa->ddrsa_recursive) {
1652 VERIFY0(dmu_objset_find_dp(dp, hds->ds_dir->dd_object,
1653 dsl_dataset_rename_snapshot_sync_impl, ddrsa,
1654 DS_FIND_CHILDREN));
1655 } else {
1656 VERIFY0(dsl_dataset_rename_snapshot_sync_impl(dp, hds, ddrsa));
1657 }
1658 dsl_dataset_rele(hds, FTAG);
1659 }
1660
1661 int
1662 dsl_dataset_rename_snapshot(const char *fsname,
1663 const char *oldsnapname, const char *newsnapname, boolean_t recursive)
1664 {
1665 dsl_dataset_rename_snapshot_arg_t ddrsa;
1666
1667 ddrsa.ddrsa_fsname = fsname;
1668 ddrsa.ddrsa_oldsnapname = oldsnapname;
1669 ddrsa.ddrsa_newsnapname = newsnapname;
1670 ddrsa.ddrsa_recursive = recursive;
1671
1672 return (dsl_sync_task(fsname, dsl_dataset_rename_snapshot_check,
1673 dsl_dataset_rename_snapshot_sync, &ddrsa, 1));
1674 }
1675
1676 static int
1677 dsl_dataset_rollback_check(void *arg, dmu_tx_t *tx)
1678 {
1679 const char *fsname = arg;
1680 dsl_pool_t *dp = dmu_tx_pool(tx);
1681 dsl_dataset_t *ds;
1682 int64_t unused_refres_delta;
1683 int error;
1684
1685 error = dsl_dataset_hold(dp, fsname, FTAG, &ds);
1686 if (error != 0)
1687 return (error);
1688
1689 /* must not be a snapshot */
1690 if (dsl_dataset_is_snapshot(ds)) {
1691 dsl_dataset_rele(ds, FTAG);
1692 return (SET_ERROR(EINVAL));
1693 }
1694
1695 /* must have a most recent snapshot */
1696 if (ds->ds_phys->ds_prev_snap_txg < TXG_INITIAL) {
1697 dsl_dataset_rele(ds, FTAG);
1698 return (SET_ERROR(EINVAL));
1699 }
1700
1701 if (dsl_dataset_long_held(ds)) {
1702 dsl_dataset_rele(ds, FTAG);
1703 return (SET_ERROR(EBUSY));
1704 }
1705
1706 /*
1707 * Check if the snap we are rolling back to uses more than
1708 * the refquota.
1709 */
1710 if (ds->ds_quota != 0 &&
1711 ds->ds_prev->ds_phys->ds_referenced_bytes > ds->ds_quota) {
1712 dsl_dataset_rele(ds, FTAG);
1713 return (SET_ERROR(EDQUOT));
1714 }
1715
1716 /*
1717 * When we do the clone swap, we will temporarily use more space
1718 * due to the refreservation (the head will no longer have any
1719 * unique space, so the entire amount of the refreservation will need
1720 * to be free). We will immediately destroy the clone, freeing
1721 * this space, but the freeing happens over many txg's.
1722 */
1723 unused_refres_delta = (int64_t)MIN(ds->ds_reserved,
1724 ds->ds_phys->ds_unique_bytes);
1725
1726 if (unused_refres_delta > 0 &&
1727 unused_refres_delta >
1728 dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE)) {
1729 dsl_dataset_rele(ds, FTAG);
1730 return (SET_ERROR(ENOSPC));
1731 }
1732
1733 dsl_dataset_rele(ds, FTAG);
1734 return (0);
1735 }
1736
1737 static void
1738 dsl_dataset_rollback_sync(void *arg, dmu_tx_t *tx)
1739 {
1740 const char *fsname = arg;
1741 dsl_pool_t *dp = dmu_tx_pool(tx);
1742 dsl_dataset_t *ds, *clone;
1743 uint64_t cloneobj;
1744
1745 VERIFY0(dsl_dataset_hold(dp, fsname, FTAG, &ds));
1746
1747 cloneobj = dsl_dataset_create_sync(ds->ds_dir, "%rollback",
1748 ds->ds_prev, DS_CREATE_FLAG_NODIRTY, kcred, tx);
1749
1750 VERIFY0(dsl_dataset_hold_obj(dp, cloneobj, FTAG, &clone));
1751
1752 dsl_dataset_clone_swap_sync_impl(clone, ds, tx);
1753 dsl_dataset_zero_zil(ds, tx);
1754
1755 dsl_destroy_head_sync_impl(clone, tx);
1756
1757 dsl_dataset_rele(clone, FTAG);
1758 dsl_dataset_rele(ds, FTAG);
1759 }
1760
1761 int
1762 dsl_dataset_rollback(const char *fsname)
1763 {
1764 return (dsl_sync_task(fsname, dsl_dataset_rollback_check,
1765 dsl_dataset_rollback_sync, (void *)fsname, 1));
1766 }
1767
1768 struct promotenode {
1769 list_node_t link;
1770 dsl_dataset_t *ds;
1771 };
1772
1773 typedef struct dsl_dataset_promote_arg {
1774 const char *ddpa_clonename;
1775 dsl_dataset_t *ddpa_clone;
1776 list_t shared_snaps, origin_snaps, clone_snaps;
1777 dsl_dataset_t *origin_origin; /* origin of the origin */
1778 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap;
1779 char *err_ds;
1780 } dsl_dataset_promote_arg_t;
1781
1782 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep);
1783 static int promote_hold(dsl_dataset_promote_arg_t *ddpa, dsl_pool_t *dp,
1784 void *tag);
1785 static void promote_rele(dsl_dataset_promote_arg_t *ddpa, void *tag);
1786
1787 static int
1788 dsl_dataset_promote_check(void *arg, dmu_tx_t *tx)
1789 {
1790 dsl_dataset_promote_arg_t *ddpa = arg;
1791 dsl_pool_t *dp = dmu_tx_pool(tx);
1792 dsl_dataset_t *hds;
1793 struct promotenode *snap;
1794 dsl_dataset_t *origin_ds;
1795 int err;
1796 uint64_t unused;
1797
1798 err = promote_hold(ddpa, dp, FTAG);
1799 if (err != 0)
1800 return (err);
1801
1802 hds = ddpa->ddpa_clone;
1803
1804 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE) {
1805 promote_rele(ddpa, FTAG);
1806 return (SET_ERROR(EXDEV));
1807 }
1808
1809 /*
1810 * Compute and check the amount of space to transfer. Since this is
1811 * so expensive, don't do the preliminary check.
1812 */
1813 if (!dmu_tx_is_syncing(tx)) {
1814 promote_rele(ddpa, FTAG);
1815 return (0);
1816 }
1817
1818 snap = list_head(&ddpa->shared_snaps);
1819 origin_ds = snap->ds;
1820
1821 /* compute origin's new unique space */
1822 snap = list_tail(&ddpa->clone_snaps);
1823 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
1824 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
1825 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX,
1826 &ddpa->unique, &unused, &unused);
1827
1828 /*
1829 * Walk the snapshots that we are moving
1830 *
1831 * Compute space to transfer. Consider the incremental changes
1832 * to used by each snapshot:
1833 * (my used) = (prev's used) + (blocks born) - (blocks killed)
1834 * So each snapshot gave birth to:
1835 * (blocks born) = (my used) - (prev's used) + (blocks killed)
1836 * So a sequence would look like:
1837 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0)
1838 * Which simplifies to:
1839 * uN + kN + kN-1 + ... + k1 + k0
1840 * Note however, if we stop before we reach the ORIGIN we get:
1841 * uN + kN + kN-1 + ... + kM - uM-1
1842 */
1843 ddpa->used = origin_ds->ds_phys->ds_referenced_bytes;
1844 ddpa->comp = origin_ds->ds_phys->ds_compressed_bytes;
1845 ddpa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes;
1846 for (snap = list_head(&ddpa->shared_snaps); snap;
1847 snap = list_next(&ddpa->shared_snaps, snap)) {
1848 uint64_t val, dlused, dlcomp, dluncomp;
1849 dsl_dataset_t *ds = snap->ds;
1850
1851 /*
1852 * If there are long holds, we won't be able to evict
1853 * the objset.
1854 */
1855 if (dsl_dataset_long_held(ds)) {
1856 err = SET_ERROR(EBUSY);
1857 goto out;
1858 }
1859
1860 /* Check that the snapshot name does not conflict */
1861 VERIFY0(dsl_dataset_get_snapname(ds));
1862 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val);
1863 if (err == 0) {
1864 (void) strcpy(ddpa->err_ds, snap->ds->ds_snapname);
1865 err = SET_ERROR(EEXIST);
1866 goto out;
1867 }
1868 if (err != ENOENT)
1869 goto out;
1870
1871 /* The very first snapshot does not have a deadlist */
1872 if (ds->ds_phys->ds_prev_snap_obj == 0)
1873 continue;
1874
1875 dsl_deadlist_space(&ds->ds_deadlist,
1876 &dlused, &dlcomp, &dluncomp);
1877 ddpa->used += dlused;
1878 ddpa->comp += dlcomp;
1879 ddpa->uncomp += dluncomp;
1880 }
1881
1882 /*
1883 * If we are a clone of a clone then we never reached ORIGIN,
1884 * so we need to subtract out the clone origin's used space.
1885 */
1886 if (ddpa->origin_origin) {
1887 ddpa->used -= ddpa->origin_origin->ds_phys->ds_referenced_bytes;
1888 ddpa->comp -= ddpa->origin_origin->ds_phys->ds_compressed_bytes;
1889 ddpa->uncomp -=
1890 ddpa->origin_origin->ds_phys->ds_uncompressed_bytes;
1891 }
1892
1893 /* Check that there is enough space here */
1894 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir,
1895 ddpa->used);
1896 if (err != 0)
1897 goto out;
1898
1899 /*
1900 * Compute the amounts of space that will be used by snapshots
1901 * after the promotion (for both origin and clone). For each,
1902 * it is the amount of space that will be on all of their
1903 * deadlists (that was not born before their new origin).
1904 */
1905 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
1906 uint64_t space;
1907
1908 /*
1909 * Note, typically this will not be a clone of a clone,
1910 * so dd_origin_txg will be < TXG_INITIAL, so
1911 * these snaplist_space() -> dsl_deadlist_space_range()
1912 * calls will be fast because they do not have to
1913 * iterate over all bps.
1914 */
1915 snap = list_head(&ddpa->origin_snaps);
1916 err = snaplist_space(&ddpa->shared_snaps,
1917 snap->ds->ds_dir->dd_origin_txg, &ddpa->cloneusedsnap);
1918 if (err != 0)
1919 goto out;
1920
1921 err = snaplist_space(&ddpa->clone_snaps,
1922 snap->ds->ds_dir->dd_origin_txg, &space);
1923 if (err != 0)
1924 goto out;
1925 ddpa->cloneusedsnap += space;
1926 }
1927 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
1928 err = snaplist_space(&ddpa->origin_snaps,
1929 origin_ds->ds_phys->ds_creation_txg, &ddpa->originusedsnap);
1930 if (err != 0)
1931 goto out;
1932 }
1933
1934 out:
1935 promote_rele(ddpa, FTAG);
1936 return (err);
1937 }
1938
1939 static void
1940 dsl_dataset_promote_sync(void *arg, dmu_tx_t *tx)
1941 {
1942 dsl_dataset_promote_arg_t *ddpa = arg;
1943 dsl_pool_t *dp = dmu_tx_pool(tx);
1944 dsl_dataset_t *hds;
1945 struct promotenode *snap;
1946 dsl_dataset_t *origin_ds;
1947 dsl_dataset_t *origin_head;
1948 dsl_dir_t *dd;
1949 dsl_dir_t *odd = NULL;
1950 uint64_t oldnext_obj;
1951 int64_t delta;
1952
1953 VERIFY0(promote_hold(ddpa, dp, FTAG));
1954 hds = ddpa->ddpa_clone;
1955
1956 ASSERT0(hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE);
1957
1958 snap = list_head(&ddpa->shared_snaps);
1959 origin_ds = snap->ds;
1960 dd = hds->ds_dir;
1961
1962 snap = list_head(&ddpa->origin_snaps);
1963 origin_head = snap->ds;
1964
1965 /*
1966 * We need to explicitly open odd, since origin_ds's dd will be
1967 * changing.
1968 */
1969 VERIFY0(dsl_dir_hold_obj(dp, origin_ds->ds_dir->dd_object,
1970 NULL, FTAG, &odd));
1971
1972 /* change origin's next snap */
1973 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx);
1974 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj;
1975 snap = list_tail(&ddpa->clone_snaps);
1976 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
1977 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object;
1978
1979 /* change the origin's next clone */
1980 if (origin_ds->ds_phys->ds_next_clones_obj) {
1981 dsl_dataset_remove_from_next_clones(origin_ds,
1982 snap->ds->ds_object, tx);
1983 VERIFY0(zap_add_int(dp->dp_meta_objset,
1984 origin_ds->ds_phys->ds_next_clones_obj,
1985 oldnext_obj, tx));
1986 }
1987
1988 /* change origin */
1989 dmu_buf_will_dirty(dd->dd_dbuf, tx);
1990 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object);
1991 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj;
1992 dd->dd_origin_txg = origin_head->ds_dir->dd_origin_txg;
1993 dmu_buf_will_dirty(odd->dd_dbuf, tx);
1994 odd->dd_phys->dd_origin_obj = origin_ds->ds_object;
1995 origin_head->ds_dir->dd_origin_txg =
1996 origin_ds->ds_phys->ds_creation_txg;
1997
1998 /* change dd_clone entries */
1999 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2000 VERIFY0(zap_remove_int(dp->dp_meta_objset,
2001 odd->dd_phys->dd_clones, hds->ds_object, tx));
2002 VERIFY0(zap_add_int(dp->dp_meta_objset,
2003 ddpa->origin_origin->ds_dir->dd_phys->dd_clones,
2004 hds->ds_object, tx));
2005
2006 VERIFY0(zap_remove_int(dp->dp_meta_objset,
2007 ddpa->origin_origin->ds_dir->dd_phys->dd_clones,
2008 origin_head->ds_object, tx));
2009 if (dd->dd_phys->dd_clones == 0) {
2010 dd->dd_phys->dd_clones = zap_create(dp->dp_meta_objset,
2011 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
2012 }
2013 VERIFY0(zap_add_int(dp->dp_meta_objset,
2014 dd->dd_phys->dd_clones, origin_head->ds_object, tx));
2015 }
2016
2017 /* move snapshots to this dir */
2018 for (snap = list_head(&ddpa->shared_snaps); snap;
2019 snap = list_next(&ddpa->shared_snaps, snap)) {
2020 dsl_dataset_t *ds = snap->ds;
2021
2022 /*
2023 * Property callbacks are registered to a particular
2024 * dsl_dir. Since ours is changing, evict the objset
2025 * so that they will be unregistered from the old dsl_dir.
2026 */
2027 if (ds->ds_objset) {
2028 dmu_objset_evict(ds->ds_objset);
2029 ds->ds_objset = NULL;
2030 }
2031
2032 /* move snap name entry */
2033 VERIFY0(dsl_dataset_get_snapname(ds));
2034 VERIFY0(dsl_dataset_snap_remove(origin_head,
2035 ds->ds_snapname, tx));
2036 VERIFY0(zap_add(dp->dp_meta_objset,
2037 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname,
2038 8, 1, &ds->ds_object, tx));
2039
2040 /* change containing dsl_dir */
2041 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2042 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object);
2043 ds->ds_phys->ds_dir_obj = dd->dd_object;
2044 ASSERT3P(ds->ds_dir, ==, odd);
2045 dsl_dir_rele(ds->ds_dir, ds);
2046 VERIFY0(dsl_dir_hold_obj(dp, dd->dd_object,
2047 NULL, ds, &ds->ds_dir));
2048
2049 /* move any clone references */
2050 if (ds->ds_phys->ds_next_clones_obj &&
2051 spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2052 zap_cursor_t zc;
2053 zap_attribute_t za;
2054
2055 for (zap_cursor_init(&zc, dp->dp_meta_objset,
2056 ds->ds_phys->ds_next_clones_obj);
2057 zap_cursor_retrieve(&zc, &za) == 0;
2058 zap_cursor_advance(&zc)) {
2059 dsl_dataset_t *cnds;
2060 uint64_t o;
2061
2062 if (za.za_first_integer == oldnext_obj) {
2063 /*
2064 * We've already moved the
2065 * origin's reference.
2066 */
2067 continue;
2068 }
2069
2070 VERIFY0(dsl_dataset_hold_obj(dp,
2071 za.za_first_integer, FTAG, &cnds));
2072 o = cnds->ds_dir->dd_phys->dd_head_dataset_obj;
2073
2074 VERIFY0(zap_remove_int(dp->dp_meta_objset,
2075 odd->dd_phys->dd_clones, o, tx));
2076 VERIFY0(zap_add_int(dp->dp_meta_objset,
2077 dd->dd_phys->dd_clones, o, tx));
2078 dsl_dataset_rele(cnds, FTAG);
2079 }
2080 zap_cursor_fini(&zc);
2081 }
2082
2083 ASSERT(!dsl_prop_hascb(ds));
2084 }
2085
2086 /*
2087 * Change space accounting.
2088 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either
2089 * both be valid, or both be 0 (resulting in delta == 0). This
2090 * is true for each of {clone,origin} independently.
2091 */
2092
2093 delta = ddpa->cloneusedsnap -
2094 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2095 ASSERT3S(delta, >=, 0);
2096 ASSERT3U(ddpa->used, >=, delta);
2097 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx);
2098 dsl_dir_diduse_space(dd, DD_USED_HEAD,
2099 ddpa->used - delta, ddpa->comp, ddpa->uncomp, tx);
2100
2101 delta = ddpa->originusedsnap -
2102 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2103 ASSERT3S(delta, <=, 0);
2104 ASSERT3U(ddpa->used, >=, -delta);
2105 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx);
2106 dsl_dir_diduse_space(odd, DD_USED_HEAD,
2107 -ddpa->used - delta, -ddpa->comp, -ddpa->uncomp, tx);
2108
2109 origin_ds->ds_phys->ds_unique_bytes = ddpa->unique;
2110
2111 /* log history record */
2112 spa_history_log_internal_ds(hds, "promote", tx, "");
2113
2114 dsl_dir_rele(odd, FTAG);
2115 promote_rele(ddpa, FTAG);
2116 }
2117
2118 /*
2119 * Make a list of dsl_dataset_t's for the snapshots between first_obj
2120 * (exclusive) and last_obj (inclusive). The list will be in reverse
2121 * order (last_obj will be the list_head()). If first_obj == 0, do all
2122 * snapshots back to this dataset's origin.
2123 */
2124 static int
2125 snaplist_make(dsl_pool_t *dp,
2126 uint64_t first_obj, uint64_t last_obj, list_t *l, void *tag)
2127 {
2128 uint64_t obj = last_obj;
2129
2130 list_create(l, sizeof (struct promotenode),
2131 offsetof(struct promotenode, link));
2132
2133 while (obj != first_obj) {
2134 dsl_dataset_t *ds;
2135 struct promotenode *snap;
2136 int err;
2137
2138 err = dsl_dataset_hold_obj(dp, obj, tag, &ds);
2139 ASSERT(err != ENOENT);
2140 if (err != 0)
2141 return (err);
2142
2143 if (first_obj == 0)
2144 first_obj = ds->ds_dir->dd_phys->dd_origin_obj;
2145
2146 snap = kmem_alloc(sizeof (*snap), KM_SLEEP);
2147 snap->ds = ds;
2148 list_insert_tail(l, snap);
2149 obj = ds->ds_phys->ds_prev_snap_obj;
2150 }
2151
2152 return (0);
2153 }
2154
2155 static int
2156 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep)
2157 {
2158 struct promotenode *snap;
2159
2160 *spacep = 0;
2161 for (snap = list_head(l); snap; snap = list_next(l, snap)) {
2162 uint64_t used, comp, uncomp;
2163 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2164 mintxg, UINT64_MAX, &used, &comp, &uncomp);
2165 *spacep += used;
2166 }
2167 return (0);
2168 }
2169
2170 static void
2171 snaplist_destroy(list_t *l, void *tag)
2172 {
2173 struct promotenode *snap;
2174
2175 if (l == NULL || !list_link_active(&l->list_head))
2176 return;
2177
2178 while ((snap = list_tail(l)) != NULL) {
2179 list_remove(l, snap);
2180 dsl_dataset_rele(snap->ds, tag);
2181 kmem_free(snap, sizeof (*snap));
2182 }
2183 list_destroy(l);
2184 }
2185
2186 static int
2187 promote_hold(dsl_dataset_promote_arg_t *ddpa, dsl_pool_t *dp, void *tag)
2188 {
2189 int error;
2190 dsl_dir_t *dd;
2191 struct promotenode *snap;
2192
2193 error = dsl_dataset_hold(dp, ddpa->ddpa_clonename, tag,
2194 &ddpa->ddpa_clone);
2195 if (error != 0)
2196 return (error);
2197 dd = ddpa->ddpa_clone->ds_dir;
2198
2199 if (dsl_dataset_is_snapshot(ddpa->ddpa_clone) ||
2200 !dsl_dir_is_clone(dd)) {
2201 dsl_dataset_rele(ddpa->ddpa_clone, tag);
2202 return (SET_ERROR(EINVAL));
2203 }
2204
2205 error = snaplist_make(dp, 0, dd->dd_phys->dd_origin_obj,
2206 &ddpa->shared_snaps, tag);
2207 if (error != 0)
2208 goto out;
2209
2210 error = snaplist_make(dp, 0, ddpa->ddpa_clone->ds_object,
2211 &ddpa->clone_snaps, tag);
2212 if (error != 0)
2213 goto out;
2214
2215 snap = list_head(&ddpa->shared_snaps);
2216 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj);
2217 error = snaplist_make(dp, dd->dd_phys->dd_origin_obj,
2218 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj,
2219 &ddpa->origin_snaps, tag);
2220 if (error != 0)
2221 goto out;
2222
2223 if (snap->ds->ds_dir->dd_phys->dd_origin_obj != 0) {
2224 error = dsl_dataset_hold_obj(dp,
2225 snap->ds->ds_dir->dd_phys->dd_origin_obj,
2226 tag, &ddpa->origin_origin);
2227 if (error != 0)
2228 goto out;
2229 }
2230 out:
2231 if (error != 0)
2232 promote_rele(ddpa, tag);
2233 return (error);
2234 }
2235
2236 static void
2237 promote_rele(dsl_dataset_promote_arg_t *ddpa, void *tag)
2238 {
2239 snaplist_destroy(&ddpa->shared_snaps, tag);
2240 snaplist_destroy(&ddpa->clone_snaps, tag);
2241 snaplist_destroy(&ddpa->origin_snaps, tag);
2242 if (ddpa->origin_origin != NULL)
2243 dsl_dataset_rele(ddpa->origin_origin, tag);
2244 dsl_dataset_rele(ddpa->ddpa_clone, tag);
2245 }
2246
2247 /*
2248 * Promote a clone.
2249 *
2250 * If it fails due to a conflicting snapshot name, "conflsnap" will be filled
2251 * in with the name. (It must be at least MAXNAMELEN bytes long.)
2252 */
2253 int
2254 dsl_dataset_promote(const char *name, char *conflsnap)
2255 {
2256 dsl_dataset_promote_arg_t ddpa = { 0 };
2257 uint64_t numsnaps;
2258 int error;
2259 objset_t *os;
2260
2261 /*
2262 * We will modify space proportional to the number of
2263 * snapshots. Compute numsnaps.
2264 */
2265 error = dmu_objset_hold(name, FTAG, &os);
2266 if (error != 0)
2267 return (error);
2268 error = zap_count(dmu_objset_pool(os)->dp_meta_objset,
2269 dmu_objset_ds(os)->ds_phys->ds_snapnames_zapobj, &numsnaps);
2270 dmu_objset_rele(os, FTAG);
2271 if (error != 0)
2272 return (error);
2273
2274 ddpa.ddpa_clonename = name;
2275 ddpa.err_ds = conflsnap;
2276
2277 return (dsl_sync_task(name, dsl_dataset_promote_check,
2278 dsl_dataset_promote_sync, &ddpa, 2 + numsnaps));
2279 }
2280
2281 int
2282 dsl_dataset_clone_swap_check_impl(dsl_dataset_t *clone,
2283 dsl_dataset_t *origin_head, boolean_t force)
2284 {
2285 int64_t unused_refres_delta;
2286
2287 /* they should both be heads */
2288 if (dsl_dataset_is_snapshot(clone) ||
2289 dsl_dataset_is_snapshot(origin_head))
2290 return (SET_ERROR(EINVAL));
2291
2292 /* the branch point should be just before them */
2293 if (clone->ds_prev != origin_head->ds_prev)
2294 return (SET_ERROR(EINVAL));
2295
2296 /* clone should be the clone (unless they are unrelated) */
2297 if (clone->ds_prev != NULL &&
2298 clone->ds_prev != clone->ds_dir->dd_pool->dp_origin_snap &&
2299 origin_head->ds_object !=
2300 clone->ds_prev->ds_phys->ds_next_snap_obj)
2301 return (SET_ERROR(EINVAL));
2302
2303 /* the clone should be a child of the origin */
2304 if (clone->ds_dir->dd_parent != origin_head->ds_dir)
2305 return (SET_ERROR(EINVAL));
2306
2307 /* origin_head shouldn't be modified unless 'force' */
2308 if (!force && dsl_dataset_modified_since_lastsnap(origin_head))
2309 return (SET_ERROR(ETXTBSY));
2310
2311 /* origin_head should have no long holds (e.g. is not mounted) */
2312 if (dsl_dataset_long_held(origin_head))
2313 return (SET_ERROR(EBUSY));
2314
2315 /* check amount of any unconsumed refreservation */
2316 unused_refres_delta =
2317 (int64_t)MIN(origin_head->ds_reserved,
2318 origin_head->ds_phys->ds_unique_bytes) -
2319 (int64_t)MIN(origin_head->ds_reserved,
2320 clone->ds_phys->ds_unique_bytes);
2321
2322 if (unused_refres_delta > 0 &&
2323 unused_refres_delta >
2324 dsl_dir_space_available(origin_head->ds_dir, NULL, 0, TRUE))
2325 return (SET_ERROR(ENOSPC));
2326
2327 /* clone can't be over the head's refquota */
2328 if (origin_head->ds_quota != 0 &&
2329 clone->ds_phys->ds_referenced_bytes > origin_head->ds_quota)
2330 return (SET_ERROR(EDQUOT));
2331
2332 return (0);
2333 }
2334
2335 void
2336 dsl_dataset_clone_swap_sync_impl(dsl_dataset_t *clone,
2337 dsl_dataset_t *origin_head, dmu_tx_t *tx)
2338 {
2339 dsl_pool_t *dp = dmu_tx_pool(tx);
2340 int64_t unused_refres_delta;
2341
2342 ASSERT(clone->ds_reserved == 0);
2343 ASSERT(origin_head->ds_quota == 0 ||
2344 clone->ds_phys->ds_unique_bytes <= origin_head->ds_quota);
2345
2346 dmu_buf_will_dirty(clone->ds_dbuf, tx);
2347 dmu_buf_will_dirty(origin_head->ds_dbuf, tx);
2348
2349 if (clone->ds_objset != NULL) {
2350 dmu_objset_evict(clone->ds_objset);
2351 clone->ds_objset = NULL;
2352 }
2353
2354 if (origin_head->ds_objset != NULL) {
2355 dmu_objset_evict(origin_head->ds_objset);
2356 origin_head->ds_objset = NULL;
2357 }
2358
2359 unused_refres_delta =
2360 (int64_t)MIN(origin_head->ds_reserved,
2361 origin_head->ds_phys->ds_unique_bytes) -
2362 (int64_t)MIN(origin_head->ds_reserved,
2363 clone->ds_phys->ds_unique_bytes);
2364
2365 /*
2366 * Reset origin's unique bytes, if it exists.
2367 */
2368 if (clone->ds_prev) {
2369 dsl_dataset_t *origin = clone->ds_prev;
2370 uint64_t comp, uncomp;
2371
2372 dmu_buf_will_dirty(origin->ds_dbuf, tx);
2373 dsl_deadlist_space_range(&clone->ds_deadlist,
2374 origin->ds_phys->ds_prev_snap_txg, UINT64_MAX,
2375 &origin->ds_phys->ds_unique_bytes, &comp, &uncomp);
2376 }
2377
2378 /* swap blkptrs */
2379 {
2380 blkptr_t tmp;
2381 tmp = origin_head->ds_phys->ds_bp;
2382 origin_head->ds_phys->ds_bp = clone->ds_phys->ds_bp;
2383 clone->ds_phys->ds_bp = tmp;
2384 }
2385
2386 /* set dd_*_bytes */
2387 {
2388 int64_t dused, dcomp, duncomp;
2389 uint64_t cdl_used, cdl_comp, cdl_uncomp;
2390 uint64_t odl_used, odl_comp, odl_uncomp;
2391
2392 ASSERT3U(clone->ds_dir->dd_phys->
2393 dd_used_breakdown[DD_USED_SNAP], ==, 0);
2394
2395 dsl_deadlist_space(&clone->ds_deadlist,
2396 &cdl_used, &cdl_comp, &cdl_uncomp);
2397 dsl_deadlist_space(&origin_head->ds_deadlist,
2398 &odl_used, &odl_comp, &odl_uncomp);
2399
2400 dused = clone->ds_phys->ds_referenced_bytes + cdl_used -
2401 (origin_head->ds_phys->ds_referenced_bytes + odl_used);
2402 dcomp = clone->ds_phys->ds_compressed_bytes + cdl_comp -
2403 (origin_head->ds_phys->ds_compressed_bytes + odl_comp);
2404 duncomp = clone->ds_phys->ds_uncompressed_bytes +
2405 cdl_uncomp -
2406 (origin_head->ds_phys->ds_uncompressed_bytes + odl_uncomp);
2407
2408 dsl_dir_diduse_space(origin_head->ds_dir, DD_USED_HEAD,
2409 dused, dcomp, duncomp, tx);
2410 dsl_dir_diduse_space(clone->ds_dir, DD_USED_HEAD,
2411 -dused, -dcomp, -duncomp, tx);
2412
2413 /*
2414 * The difference in the space used by snapshots is the
2415 * difference in snapshot space due to the head's
2416 * deadlist (since that's the only thing that's
2417 * changing that affects the snapused).
2418 */
2419 dsl_deadlist_space_range(&clone->ds_deadlist,
2420 origin_head->ds_dir->dd_origin_txg, UINT64_MAX,
2421 &cdl_used, &cdl_comp, &cdl_uncomp);
2422 dsl_deadlist_space_range(&origin_head->ds_deadlist,
2423 origin_head->ds_dir->dd_origin_txg, UINT64_MAX,
2424 &odl_used, &odl_comp, &odl_uncomp);
2425 dsl_dir_transfer_space(origin_head->ds_dir, cdl_used - odl_used,
2426 DD_USED_HEAD, DD_USED_SNAP, tx);
2427 }
2428
2429 /* swap ds_*_bytes */
2430 SWITCH64(origin_head->ds_phys->ds_referenced_bytes,
2431 clone->ds_phys->ds_referenced_bytes);
2432 SWITCH64(origin_head->ds_phys->ds_compressed_bytes,
2433 clone->ds_phys->ds_compressed_bytes);
2434 SWITCH64(origin_head->ds_phys->ds_uncompressed_bytes,
2435 clone->ds_phys->ds_uncompressed_bytes);
2436 SWITCH64(origin_head->ds_phys->ds_unique_bytes,
2437 clone->ds_phys->ds_unique_bytes);
2438
2439 /* apply any parent delta for change in unconsumed refreservation */
2440 dsl_dir_diduse_space(origin_head->ds_dir, DD_USED_REFRSRV,
2441 unused_refres_delta, 0, 0, tx);
2442
2443 /*
2444 * Swap deadlists.
2445 */
2446 dsl_deadlist_close(&clone->ds_deadlist);
2447 dsl_deadlist_close(&origin_head->ds_deadlist);
2448 SWITCH64(origin_head->ds_phys->ds_deadlist_obj,
2449 clone->ds_phys->ds_deadlist_obj);
2450 dsl_deadlist_open(&clone->ds_deadlist, dp->dp_meta_objset,
2451 clone->ds_phys->ds_deadlist_obj);
2452 dsl_deadlist_open(&origin_head->ds_deadlist, dp->dp_meta_objset,
2453 origin_head->ds_phys->ds_deadlist_obj);
2454
2455 dsl_scan_ds_clone_swapped(origin_head, clone, tx);
2456
2457 spa_history_log_internal_ds(clone, "clone swap", tx,
2458 "parent=%s", origin_head->ds_dir->dd_myname);
2459 }
2460
2461 /*
2462 * Given a pool name and a dataset object number in that pool,
2463 * return the name of that dataset.
2464 */
2465 int
2466 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf)
2467 {
2468 dsl_pool_t *dp;
2469 dsl_dataset_t *ds;
2470 int error;
2471
2472 error = dsl_pool_hold(pname, FTAG, &dp);
2473 if (error != 0)
2474 return (error);
2475
2476 error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds);
2477 if (error == 0) {
2478 dsl_dataset_name(ds, buf);
2479 dsl_dataset_rele(ds, FTAG);
2480 }
2481 dsl_pool_rele(dp, FTAG);
2482
2483 return (error);
2484 }
2485
2486 int
2487 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota,
2488 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv)
2489 {
2490 int error = 0;
2491
2492 ASSERT3S(asize, >, 0);
2493
2494 /*
2495 * *ref_rsrv is the portion of asize that will come from any
2496 * unconsumed refreservation space.
2497 */
2498 *ref_rsrv = 0;
2499
2500 mutex_enter(&ds->ds_lock);
2501 /*
2502 * Make a space adjustment for reserved bytes.
2503 */
2504 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) {
2505 ASSERT3U(*used, >=,
2506 ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
2507 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
2508 *ref_rsrv =
2509 asize - MIN(asize, parent_delta(ds, asize + inflight));
2510 }
2511
2512 if (!check_quota || ds->ds_quota == 0) {
2513 mutex_exit(&ds->ds_lock);
2514 return (0);
2515 }
2516 /*
2517 * If they are requesting more space, and our current estimate
2518 * is over quota, they get to try again unless the actual
2519 * on-disk is over quota and there are no pending changes (which
2520 * may free up space for us).
2521 */
2522 if (ds->ds_phys->ds_referenced_bytes + inflight >= ds->ds_quota) {
2523 if (inflight > 0 ||
2524 ds->ds_phys->ds_referenced_bytes < ds->ds_quota)
2525 error = SET_ERROR(ERESTART);
2526 else
2527 error = SET_ERROR(EDQUOT);
2528 }
2529 mutex_exit(&ds->ds_lock);
2530
2531 return (error);
2532 }
2533
2534 typedef struct dsl_dataset_set_qr_arg {
2535 const char *ddsqra_name;
2536 zprop_source_t ddsqra_source;
2537 uint64_t ddsqra_value;
2538 } dsl_dataset_set_qr_arg_t;
2539
2540
2541 /* ARGSUSED */
2542 static int
2543 dsl_dataset_set_refquota_check(void *arg, dmu_tx_t *tx)
2544 {
2545 dsl_dataset_set_qr_arg_t *ddsqra = arg;
2546 dsl_pool_t *dp = dmu_tx_pool(tx);
2547 dsl_dataset_t *ds;
2548 int error;
2549 uint64_t newval;
2550
2551 if (spa_version(dp->dp_spa) < SPA_VERSION_REFQUOTA)
2552 return (SET_ERROR(ENOTSUP));
2553
2554 error = dsl_dataset_hold(dp, ddsqra->ddsqra_name, FTAG, &ds);
2555 if (error != 0)
2556 return (error);
2557
2558 if (dsl_dataset_is_snapshot(ds)) {
2559 dsl_dataset_rele(ds, FTAG);
2560 return (SET_ERROR(EINVAL));
2561 }
2562
2563 error = dsl_prop_predict(ds->ds_dir,
2564 zfs_prop_to_name(ZFS_PROP_REFQUOTA),
2565 ddsqra->ddsqra_source, ddsqra->ddsqra_value, &newval);
2566 if (error != 0) {
2567 dsl_dataset_rele(ds, FTAG);
2568 return (error);
2569 }
2570
2571 if (newval == 0) {
2572 dsl_dataset_rele(ds, FTAG);
2573 return (0);
2574 }
2575
2576 if (newval < ds->ds_phys->ds_referenced_bytes ||
2577 newval < ds->ds_reserved) {
2578 dsl_dataset_rele(ds, FTAG);
2579 return (SET_ERROR(ENOSPC));
2580 }
2581
2582 dsl_dataset_rele(ds, FTAG);
2583 return (0);
2584 }
2585
2586 static void
2587 dsl_dataset_set_refquota_sync(void *arg, dmu_tx_t *tx)
2588 {
2589 dsl_dataset_set_qr_arg_t *ddsqra = arg;
2590 dsl_pool_t *dp = dmu_tx_pool(tx);
2591 dsl_dataset_t *ds;
2592 uint64_t newval;
2593
2594 VERIFY0(dsl_dataset_hold(dp, ddsqra->ddsqra_name, FTAG, &ds));
2595
2596 dsl_prop_set_sync_impl(ds,
2597 zfs_prop_to_name(ZFS_PROP_REFQUOTA),
2598 ddsqra->ddsqra_source, sizeof (ddsqra->ddsqra_value), 1,
2599 &ddsqra->ddsqra_value, tx);
2600
2601 VERIFY0(dsl_prop_get_int_ds(ds,
2602 zfs_prop_to_name(ZFS_PROP_REFQUOTA), &newval));
2603
2604 if (ds->ds_quota != newval) {
2605 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2606 ds->ds_quota = newval;
2607 }
2608 dsl_dataset_rele(ds, FTAG);
2609 }
2610
2611 int
2612 dsl_dataset_set_refquota(const char *dsname, zprop_source_t source,
2613 uint64_t refquota)
2614 {
2615 dsl_dataset_set_qr_arg_t ddsqra;
2616
2617 ddsqra.ddsqra_name = dsname;
2618 ddsqra.ddsqra_source = source;
2619 ddsqra.ddsqra_value = refquota;
2620
2621 return (dsl_sync_task(dsname, dsl_dataset_set_refquota_check,
2622 dsl_dataset_set_refquota_sync, &ddsqra, 0));
2623 }
2624
2625 static int
2626 dsl_dataset_set_refreservation_check(void *arg, dmu_tx_t *tx)
2627 {
2628 dsl_dataset_set_qr_arg_t *ddsqra = arg;
2629 dsl_pool_t *dp = dmu_tx_pool(tx);
2630 dsl_dataset_t *ds;
2631 int error;
2632 uint64_t newval, unique;
2633
2634 if (spa_version(dp->dp_spa) < SPA_VERSION_REFRESERVATION)
2635 return (SET_ERROR(ENOTSUP));
2636
2637 error = dsl_dataset_hold(dp, ddsqra->ddsqra_name, FTAG, &ds);
2638 if (error != 0)
2639 return (error);
2640
2641 if (dsl_dataset_is_snapshot(ds)) {
2642 dsl_dataset_rele(ds, FTAG);
2643 return (SET_ERROR(EINVAL));
2644 }
2645
2646 error = dsl_prop_predict(ds->ds_dir,
2647 zfs_prop_to_name(ZFS_PROP_REFRESERVATION),
2648 ddsqra->ddsqra_source, ddsqra->ddsqra_value, &newval);
2649 if (error != 0) {
2650 dsl_dataset_rele(ds, FTAG);
2651 return (error);
2652 }
2653
2654 /*
2655 * If we are doing the preliminary check in open context, the
2656 * space estimates may be inaccurate.
2657 */
2658 if (!dmu_tx_is_syncing(tx)) {
2659 dsl_dataset_rele(ds, FTAG);
2660 return (0);
2661 }
2662
2663 mutex_enter(&ds->ds_lock);
2664 if (!DS_UNIQUE_IS_ACCURATE(ds))
2665 dsl_dataset_recalc_head_uniq(ds);
2666 unique = ds->ds_phys->ds_unique_bytes;
2667 mutex_exit(&ds->ds_lock);
2668
2669 if (MAX(unique, newval) > MAX(unique, ds->ds_reserved)) {
2670 uint64_t delta = MAX(unique, newval) -
2671 MAX(unique, ds->ds_reserved);
2672
2673 if (delta >
2674 dsl_dir_space_available(ds->ds_dir, NULL, 0, B_TRUE) ||
2675 (ds->ds_quota > 0 && newval > ds->ds_quota)) {
2676 dsl_dataset_rele(ds, FTAG);
2677 return (SET_ERROR(ENOSPC));
2678 }
2679 }
2680
2681 dsl_dataset_rele(ds, FTAG);
2682 return (0);
2683 }
2684
2685 void
2686 dsl_dataset_set_refreservation_sync_impl(dsl_dataset_t *ds,
2687 zprop_source_t source, uint64_t value, dmu_tx_t *tx)
2688 {
2689 uint64_t newval;
2690 uint64_t unique;
2691 int64_t delta;
2692
2693 dsl_prop_set_sync_impl(ds, zfs_prop_to_name(ZFS_PROP_REFRESERVATION),
2694 source, sizeof (value), 1, &value, tx);
2695
2696 VERIFY0(dsl_prop_get_int_ds(ds,
2697 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), &newval));
2698
2699 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2700 mutex_enter(&ds->ds_dir->dd_lock);
2701 mutex_enter(&ds->ds_lock);
2702 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
2703 unique = ds->ds_phys->ds_unique_bytes;
2704 delta = MAX(0, (int64_t)(newval - unique)) -
2705 MAX(0, (int64_t)(ds->ds_reserved - unique));
2706 ds->ds_reserved = newval;
2707 mutex_exit(&ds->ds_lock);
2708
2709 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx);
2710 mutex_exit(&ds->ds_dir->dd_lock);
2711 }
2712
2713 static void
2714 dsl_dataset_set_refreservation_sync(void *arg, dmu_tx_t *tx)
2715 {
2716 dsl_dataset_set_qr_arg_t *ddsqra = arg;
2717 dsl_pool_t *dp = dmu_tx_pool(tx);
2718 dsl_dataset_t *ds;
2719
2720 VERIFY0(dsl_dataset_hold(dp, ddsqra->ddsqra_name, FTAG, &ds));
2721 dsl_dataset_set_refreservation_sync_impl(ds,
2722 ddsqra->ddsqra_source, ddsqra->ddsqra_value, tx);
2723 dsl_dataset_rele(ds, FTAG);
2724 }
2725
2726 int
2727 dsl_dataset_set_refreservation(const char *dsname, zprop_source_t source,
2728 uint64_t refreservation)
2729 {
2730 dsl_dataset_set_qr_arg_t ddsqra;
2731
2732 ddsqra.ddsqra_name = dsname;
2733 ddsqra.ddsqra_source = source;
2734 ddsqra.ddsqra_value = refreservation;
2735
2736 return (dsl_sync_task(dsname, dsl_dataset_set_refreservation_check,
2737 dsl_dataset_set_refreservation_sync, &ddsqra, 0));
2738 }
2739
2740 /*
2741 * Return (in *usedp) the amount of space written in new that is not
2742 * present in oldsnap. New may be a snapshot or the head. Old must be
2743 * a snapshot before new, in new's filesystem (or its origin). If not then
2744 * fail and return EINVAL.
2745 *
2746 * The written space is calculated by considering two components: First, we
2747 * ignore any freed space, and calculate the written as new's used space
2748 * minus old's used space. Next, we add in the amount of space that was freed
2749 * between the two snapshots, thus reducing new's used space relative to old's.
2750 * Specifically, this is the space that was born before old->ds_creation_txg,
2751 * and freed before new (ie. on new's deadlist or a previous deadlist).
2752 *
2753 * space freed [---------------------]
2754 * snapshots ---O-------O--------O-------O------
2755 * oldsnap new
2756 */
2757 int
2758 dsl_dataset_space_written(dsl_dataset_t *oldsnap, dsl_dataset_t *newds,
2759 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
2760 {
2761 int err = 0;
2762 uint64_t snapobj;
2763 dsl_pool_t *dp = newds->ds_dir->dd_pool;
2764
2765 ASSERT(dsl_pool_config_held(dp));
2766
2767 *usedp = 0;
2768 *usedp += newds->ds_phys->ds_referenced_bytes;
2769 *usedp -= oldsnap->ds_phys->ds_referenced_bytes;
2770
2771 *compp = 0;
2772 *compp += newds->ds_phys->ds_compressed_bytes;
2773 *compp -= oldsnap->ds_phys->ds_compressed_bytes;
2774
2775 *uncompp = 0;
2776 *uncompp += newds->ds_phys->ds_uncompressed_bytes;
2777 *uncompp -= oldsnap->ds_phys->ds_uncompressed_bytes;
2778
2779 snapobj = newds->ds_object;
2780 while (snapobj != oldsnap->ds_object) {
2781 dsl_dataset_t *snap;
2782 uint64_t used, comp, uncomp;
2783
2784 if (snapobj == newds->ds_object) {
2785 snap = newds;
2786 } else {
2787 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &snap);
2788 if (err != 0)
2789 break;
2790 }
2791
2792 if (snap->ds_phys->ds_prev_snap_txg ==
2793 oldsnap->ds_phys->ds_creation_txg) {
2794 /*
2795 * The blocks in the deadlist can not be born after
2796 * ds_prev_snap_txg, so get the whole deadlist space,
2797 * which is more efficient (especially for old-format
2798 * deadlists). Unfortunately the deadlist code
2799 * doesn't have enough information to make this
2800 * optimization itself.
2801 */
2802 dsl_deadlist_space(&snap->ds_deadlist,
2803 &used, &comp, &uncomp);
2804 } else {
2805 dsl_deadlist_space_range(&snap->ds_deadlist,
2806 0, oldsnap->ds_phys->ds_creation_txg,
2807 &used, &comp, &uncomp);
2808 }
2809 *usedp += used;
2810 *compp += comp;
2811 *uncompp += uncomp;
2812
2813 /*
2814 * If we get to the beginning of the chain of snapshots
2815 * (ds_prev_snap_obj == 0) before oldsnap, then oldsnap
2816 * was not a snapshot of/before newds.
2817 */
2818 snapobj = snap->ds_phys->ds_prev_snap_obj;
2819 if (snap != newds)
2820 dsl_dataset_rele(snap, FTAG);
2821 if (snapobj == 0) {
2822 err = SET_ERROR(EINVAL);
2823 break;
2824 }
2825
2826 }
2827 return (err);
2828 }
2829
2830 /*
2831 * Return (in *usedp) the amount of space that will be reclaimed if firstsnap,
2832 * lastsnap, and all snapshots in between are deleted.
2833 *
2834 * blocks that would be freed [---------------------------]
2835 * snapshots ---O-------O--------O-------O--------O
2836 * firstsnap lastsnap
2837 *
2838 * This is the set of blocks that were born after the snap before firstsnap,
2839 * (birth > firstsnap->prev_snap_txg) and died before the snap after the
2840 * last snap (ie, is on lastsnap->ds_next->ds_deadlist or an earlier deadlist).
2841 * We calculate this by iterating over the relevant deadlists (from the snap
2842 * after lastsnap, backward to the snap after firstsnap), summing up the
2843 * space on the deadlist that was born after the snap before firstsnap.
2844 */
2845 int
2846 dsl_dataset_space_wouldfree(dsl_dataset_t *firstsnap,
2847 dsl_dataset_t *lastsnap,
2848 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
2849 {
2850 int err = 0;
2851 uint64_t snapobj;
2852 dsl_pool_t *dp = firstsnap->ds_dir->dd_pool;
2853
2854 ASSERT(dsl_dataset_is_snapshot(firstsnap));
2855 ASSERT(dsl_dataset_is_snapshot(lastsnap));
2856
2857 /*
2858 * Check that the snapshots are in the same dsl_dir, and firstsnap
2859 * is before lastsnap.
2860 */
2861 if (firstsnap->ds_dir != lastsnap->ds_dir ||
2862 firstsnap->ds_phys->ds_creation_txg >
2863 lastsnap->ds_phys->ds_creation_txg)
2864 return (SET_ERROR(EINVAL));
2865
2866 *usedp = *compp = *uncompp = 0;
2867
2868 snapobj = lastsnap->ds_phys->ds_next_snap_obj;
2869 while (snapobj != firstsnap->ds_object) {
2870 dsl_dataset_t *ds;
2871 uint64_t used, comp, uncomp;
2872
2873 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &ds);
2874 if (err != 0)
2875 break;
2876
2877 dsl_deadlist_space_range(&ds->ds_deadlist,
2878 firstsnap->ds_phys->ds_prev_snap_txg, UINT64_MAX,
2879 &used, &comp, &uncomp);
2880 *usedp += used;
2881 *compp += comp;
2882 *uncompp += uncomp;
2883
2884 snapobj = ds->ds_phys->ds_prev_snap_obj;
2885 ASSERT3U(snapobj, !=, 0);
2886 dsl_dataset_rele(ds, FTAG);
2887 }
2888 return (err);
2889 }
2890
2891 /*
2892 * Return TRUE if 'earlier' is an earlier snapshot in 'later's timeline.
2893 * For example, they could both be snapshots of the same filesystem, and
2894 * 'earlier' is before 'later'. Or 'earlier' could be the origin of
2895 * 'later's filesystem. Or 'earlier' could be an older snapshot in the origin's
2896 * filesystem. Or 'earlier' could be the origin's origin.
2897 */
2898 boolean_t
2899 dsl_dataset_is_before(dsl_dataset_t *later, dsl_dataset_t *earlier)
2900 {
2901 dsl_pool_t *dp = later->ds_dir->dd_pool;
2902 int error;
2903 boolean_t ret;
2904
2905 ASSERT(dsl_pool_config_held(dp));
2906
2907 if (earlier->ds_phys->ds_creation_txg >=
2908 later->ds_phys->ds_creation_txg)
2909 return (B_FALSE);
2910
2911 if (later->ds_dir == earlier->ds_dir)
2912 return (B_TRUE);
2913 if (!dsl_dir_is_clone(later->ds_dir))
2914 return (B_FALSE);
2915
2916 if (later->ds_dir->dd_phys->dd_origin_obj == earlier->ds_object)
2917 return (B_TRUE);
2918 dsl_dataset_t *origin;
2919 error = dsl_dataset_hold_obj(dp,
2920 later->ds_dir->dd_phys->dd_origin_obj, FTAG, &origin);
2921 if (error != 0)
2922 return (B_FALSE);
2923 ret = dsl_dataset_is_before(origin, earlier);
2924 dsl_dataset_rele(origin, FTAG);
2925 return (ret);
2926 }