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 dmu_buf_rele(dbuf, tag);
361 return (SET_ERROR(EINVAL));
362 }
363
364 ds = dmu_buf_get_user(dbuf);
365 if (ds == NULL) {
366 dsl_dataset_t *winner = NULL;
367
368 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP);
369 ds->ds_dbuf = dbuf;
370 ds->ds_object = dsobj;
371 ds->ds_phys = dbuf->db_data;
372
373 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL);
374 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL);
375 mutex_init(&ds->ds_sendstream_lock, NULL, MUTEX_DEFAULT, NULL);
376 refcount_create(&ds->ds_longholds);
377
378 bplist_create(&ds->ds_pending_deadlist);
379 dsl_deadlist_open(&ds->ds_deadlist,
380 mos, ds->ds_phys->ds_deadlist_obj);
381
382 list_create(&ds->ds_sendstreams, sizeof (dmu_sendarg_t),
383 offsetof(dmu_sendarg_t, dsa_link));
384
385 if (err == 0) {
386 err = dsl_dir_hold_obj(dp,
387 ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir);
388 }
389 if (err != 0) {
390 mutex_destroy(&ds->ds_lock);
391 mutex_destroy(&ds->ds_opening_lock);
392 refcount_destroy(&ds->ds_longholds);
393 bplist_destroy(&ds->ds_pending_deadlist);
394 dsl_deadlist_close(&ds->ds_deadlist);
395 kmem_free(ds, sizeof (dsl_dataset_t));
396 dmu_buf_rele(dbuf, tag);
397 return (err);
398 }
399
400 if (!dsl_dataset_is_snapshot(ds)) {
401 ds->ds_snapname[0] = '\0';
402 if (ds->ds_phys->ds_prev_snap_obj != 0) {
403 err = dsl_dataset_hold_obj(dp,
404 ds->ds_phys->ds_prev_snap_obj,
405 ds, &ds->ds_prev);
406 }
407 } else {
408 if (zfs_flags & ZFS_DEBUG_SNAPNAMES)
409 err = dsl_dataset_get_snapname(ds);
410 if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) {
411 err = zap_count(
412 ds->ds_dir->dd_pool->dp_meta_objset,
413 ds->ds_phys->ds_userrefs_obj,
414 &ds->ds_userrefs);
415 }
416 }
417
418 if (err == 0 && !dsl_dataset_is_snapshot(ds)) {
419 err = dsl_prop_get_int_ds(ds,
420 zfs_prop_to_name(ZFS_PROP_REFRESERVATION),
421 &ds->ds_reserved);
422 if (err == 0) {
423 err = dsl_prop_get_int_ds(ds,
424 zfs_prop_to_name(ZFS_PROP_REFQUOTA),
425 &ds->ds_quota);
426 }
427 } else {
428 ds->ds_reserved = ds->ds_quota = 0;
429 }
430
431 if (err != 0 || (winner = dmu_buf_set_user_ie(dbuf, ds,
432 &ds->ds_phys, dsl_dataset_evict)) != NULL) {
433 bplist_destroy(&ds->ds_pending_deadlist);
434 dsl_deadlist_close(&ds->ds_deadlist);
435 if (ds->ds_prev)
436 dsl_dataset_rele(ds->ds_prev, ds);
437 dsl_dir_rele(ds->ds_dir, ds);
438 mutex_destroy(&ds->ds_lock);
439 mutex_destroy(&ds->ds_opening_lock);
440 refcount_destroy(&ds->ds_longholds);
441 kmem_free(ds, sizeof (dsl_dataset_t));
442 if (err != 0) {
443 dmu_buf_rele(dbuf, tag);
444 return (err);
445 }
446 ds = winner;
447 } else {
448 ds->ds_fsid_guid =
449 unique_insert(ds->ds_phys->ds_fsid_guid);
450 }
451 }
452 ASSERT3P(ds->ds_dbuf, ==, dbuf);
453 ASSERT3P(ds->ds_phys, ==, dbuf->db_data);
454 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 ||
455 spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN ||
456 dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap);
457 *dsp = ds;
458 return (0);
459 }
460
461 int
462 dsl_dataset_hold(dsl_pool_t *dp, const char *name,
463 void *tag, dsl_dataset_t **dsp)
464 {
465 dsl_dir_t *dd;
466 const char *snapname;
467 uint64_t obj;
468 int err = 0;
469
470 err = dsl_dir_hold(dp, name, FTAG, &dd, &snapname);
471 if (err != 0)
472 return (err);
473
474 ASSERT(dsl_pool_config_held(dp));
475 obj = dd->dd_phys->dd_head_dataset_obj;
476 if (obj != 0)
477 err = dsl_dataset_hold_obj(dp, obj, tag, dsp);
478 else
479 err = SET_ERROR(ENOENT);
480
481 /* we may be looking for a snapshot */
482 if (err == 0 && snapname != NULL) {
483 dsl_dataset_t *ds;
484
485 if (*snapname++ != '@') {
486 dsl_dataset_rele(*dsp, tag);
487 dsl_dir_rele(dd, FTAG);
488 return (SET_ERROR(ENOENT));
489 }
490
491 dprintf("looking for snapshot '%s'\n", snapname);
492 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj);
493 if (err == 0)
494 err = dsl_dataset_hold_obj(dp, obj, tag, &ds);
495 dsl_dataset_rele(*dsp, tag);
496
497 if (err == 0) {
498 mutex_enter(&ds->ds_lock);
499 if (ds->ds_snapname[0] == 0)
500 (void) strlcpy(ds->ds_snapname, snapname,
501 sizeof (ds->ds_snapname));
502 mutex_exit(&ds->ds_lock);
503 *dsp = ds;
504 }
505 }
506
507 dsl_dir_rele(dd, FTAG);
508 return (err);
509 }
510
511 int
512 dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj,
513 void *tag, dsl_dataset_t **dsp)
514 {
515 int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp);
516 if (err != 0)
517 return (err);
518 if (!dsl_dataset_tryown(*dsp, tag)) {
519 dsl_dataset_rele(*dsp, tag);
520 *dsp = NULL;
521 return (SET_ERROR(EBUSY));
522 }
523 return (0);
524 }
525
526 int
527 dsl_dataset_own(dsl_pool_t *dp, const char *name,
528 void *tag, dsl_dataset_t **dsp)
529 {
530 int err = dsl_dataset_hold(dp, name, tag, dsp);
531 if (err != 0)
532 return (err);
533 if (!dsl_dataset_tryown(*dsp, tag)) {
534 dsl_dataset_rele(*dsp, tag);
535 return (SET_ERROR(EBUSY));
536 }
537 return (0);
538 }
539
540 /*
541 * See the comment above dsl_pool_hold() for details. In summary, a long
542 * hold is used to prevent destruction of a dataset while the pool hold
543 * is dropped, allowing other concurrent operations (e.g. spa_sync()).
544 *
545 * The dataset and pool must be held when this function is called. After it
546 * is called, the pool hold may be released while the dataset is still held
547 * and accessed.
548 */
549 void
550 dsl_dataset_long_hold(dsl_dataset_t *ds, void *tag)
551 {
552 ASSERT(dsl_pool_config_held(ds->ds_dir->dd_pool));
553 (void) refcount_add(&ds->ds_longholds, tag);
554 }
555
556 void
557 dsl_dataset_long_rele(dsl_dataset_t *ds, void *tag)
558 {
559 (void) refcount_remove(&ds->ds_longholds, tag);
560 }
561
562 /* Return B_TRUE if there are any long holds on this dataset. */
563 boolean_t
564 dsl_dataset_long_held(dsl_dataset_t *ds)
565 {
566 return (!refcount_is_zero(&ds->ds_longholds));
567 }
568
569 void
570 dsl_dataset_name(dsl_dataset_t *ds, char *name)
571 {
572 if (ds == NULL) {
573 (void) strcpy(name, "mos");
574 } else {
575 dsl_dir_name(ds->ds_dir, name);
576 VERIFY0(dsl_dataset_get_snapname(ds));
577 if (ds->ds_snapname[0]) {
578 (void) strcat(name, "@");
579 /*
580 * We use a "recursive" mutex so that we
581 * can call dprintf_ds() with ds_lock held.
582 */
583 if (!MUTEX_HELD(&ds->ds_lock)) {
584 mutex_enter(&ds->ds_lock);
585 (void) strcat(name, ds->ds_snapname);
586 mutex_exit(&ds->ds_lock);
587 } else {
588 (void) strcat(name, ds->ds_snapname);
589 }
590 }
591 }
592 }
593
594 static int
595 dsl_dataset_namelen(dsl_dataset_t *ds)
596 {
597 int result;
598
599 if (ds == NULL) {
600 result = 3; /* "mos" */
601 } else {
602 result = dsl_dir_namelen(ds->ds_dir);
603 VERIFY0(dsl_dataset_get_snapname(ds));
604 if (ds->ds_snapname[0]) {
605 ++result; /* adding one for the @-sign */
606 if (!MUTEX_HELD(&ds->ds_lock)) {
607 mutex_enter(&ds->ds_lock);
608 result += strlen(ds->ds_snapname);
609 mutex_exit(&ds->ds_lock);
610 } else {
611 result += strlen(ds->ds_snapname);
612 }
613 }
614 }
615
616 return (result);
617 }
618
619 void
620 dsl_dataset_rele(dsl_dataset_t *ds, void *tag)
621 {
622 dmu_buf_rele(ds->ds_dbuf, tag);
623 }
624
625 void
626 dsl_dataset_disown(dsl_dataset_t *ds, void *tag)
627 {
628 ASSERT(ds->ds_owner == tag && ds->ds_dbuf != NULL);
629
630 mutex_enter(&ds->ds_lock);
631 ds->ds_owner = NULL;
632 mutex_exit(&ds->ds_lock);
633 dsl_dataset_long_rele(ds, tag);
634 if (ds->ds_dbuf != NULL)
635 dsl_dataset_rele(ds, tag);
636 else
637 dsl_dataset_evict(NULL, ds);
638 }
639
640 boolean_t
641 dsl_dataset_tryown(dsl_dataset_t *ds, void *tag)
642 {
643 boolean_t gotit = FALSE;
644
645 mutex_enter(&ds->ds_lock);
646 if (ds->ds_owner == NULL && !DS_IS_INCONSISTENT(ds)) {
647 ds->ds_owner = tag;
648 dsl_dataset_long_hold(ds, tag);
649 gotit = TRUE;
650 }
651 mutex_exit(&ds->ds_lock);
652 return (gotit);
653 }
654
655 uint64_t
656 dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin,
657 uint64_t flags, dmu_tx_t *tx)
658 {
659 dsl_pool_t *dp = dd->dd_pool;
660 dmu_buf_t *dbuf;
661 dsl_dataset_phys_t *dsphys;
662 uint64_t dsobj;
663 objset_t *mos = dp->dp_meta_objset;
664
665 if (origin == NULL)
666 origin = dp->dp_origin_snap;
667
668 ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp);
669 ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0);
670 ASSERT(dmu_tx_is_syncing(tx));
671 ASSERT(dd->dd_phys->dd_head_dataset_obj == 0);
672
673 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
674 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
675 VERIFY0(dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
676 dmu_buf_will_dirty(dbuf, tx);
677 dsphys = dbuf->db_data;
678 bzero(dsphys, sizeof (dsl_dataset_phys_t));
679 dsphys->ds_dir_obj = dd->dd_object;
680 dsphys->ds_flags = flags;
681 dsphys->ds_fsid_guid = unique_create();
682 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
683 sizeof (dsphys->ds_guid));
684 dsphys->ds_snapnames_zapobj =
685 zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP,
686 DMU_OT_NONE, 0, tx);
687 dsphys->ds_creation_time = gethrestime_sec();
688 dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg;
689
690 if (origin == NULL) {
691 dsphys->ds_deadlist_obj = dsl_deadlist_alloc(mos, tx);
692 } else {
693 dsl_dataset_t *ohds; /* head of the origin snapshot */
694
695 dsphys->ds_prev_snap_obj = origin->ds_object;
696 dsphys->ds_prev_snap_txg =
697 origin->ds_phys->ds_creation_txg;
698 dsphys->ds_referenced_bytes =
699 origin->ds_phys->ds_referenced_bytes;
700 dsphys->ds_compressed_bytes =
701 origin->ds_phys->ds_compressed_bytes;
702 dsphys->ds_uncompressed_bytes =
703 origin->ds_phys->ds_uncompressed_bytes;
704 dsphys->ds_bp = origin->ds_phys->ds_bp;
705 dsphys->ds_flags |= origin->ds_phys->ds_flags;
706
707 dmu_buf_will_dirty(origin->ds_dbuf, tx);
708 origin->ds_phys->ds_num_children++;
709
710 VERIFY0(dsl_dataset_hold_obj(dp,
711 origin->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ohds));
712 dsphys->ds_deadlist_obj = dsl_deadlist_clone(&ohds->ds_deadlist,
713 dsphys->ds_prev_snap_txg, dsphys->ds_prev_snap_obj, tx);
714 dsl_dataset_rele(ohds, FTAG);
715
716 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) {
717 if (origin->ds_phys->ds_next_clones_obj == 0) {
718 origin->ds_phys->ds_next_clones_obj =
719 zap_create(mos,
720 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx);
721 }
722 VERIFY0(zap_add_int(mos,
723 origin->ds_phys->ds_next_clones_obj, dsobj, tx));
724 }
725
726 dmu_buf_will_dirty(dd->dd_dbuf, tx);
727 dd->dd_phys->dd_origin_obj = origin->ds_object;
728 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
729 if (origin->ds_dir->dd_phys->dd_clones == 0) {
730 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx);
731 origin->ds_dir->dd_phys->dd_clones =
732 zap_create(mos,
733 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
734 }
735 VERIFY0(zap_add_int(mos,
736 origin->ds_dir->dd_phys->dd_clones, dsobj, tx));
737 }
738 }
739
740 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
741 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
742
743 dmu_buf_rele(dbuf, FTAG);
744
745 dmu_buf_will_dirty(dd->dd_dbuf, tx);
746 dd->dd_phys->dd_head_dataset_obj = dsobj;
747
748 return (dsobj);
749 }
750
751 static void
752 dsl_dataset_zero_zil(dsl_dataset_t *ds, dmu_tx_t *tx)
753 {
754 objset_t *os;
755
756 VERIFY0(dmu_objset_from_ds(ds, &os));
757 bzero(&os->os_zil_header, sizeof (os->os_zil_header));
758 dsl_dataset_dirty(ds, tx);
759 }
760
761 uint64_t
762 dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname,
763 dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx)
764 {
765 dsl_pool_t *dp = pdd->dd_pool;
766 uint64_t dsobj, ddobj;
767 dsl_dir_t *dd;
768
769 ASSERT(dmu_tx_is_syncing(tx));
770 ASSERT(lastname[0] != '@');
771
772 ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx);
773 VERIFY0(dsl_dir_hold_obj(dp, ddobj, lastname, FTAG, &dd));
774
775 dsobj = dsl_dataset_create_sync_dd(dd, origin,
776 flags & ~DS_CREATE_FLAG_NODIRTY, tx);
777
778 dsl_deleg_set_create_perms(dd, tx, cr);
779
780 dsl_dir_rele(dd, FTAG);
781
782 /*
783 * If we are creating a clone, make sure we zero out any stale
784 * data from the origin snapshots zil header.
785 */
786 if (origin != NULL && !(flags & DS_CREATE_FLAG_NODIRTY)) {
787 dsl_dataset_t *ds;
788
789 VERIFY0(dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
790 dsl_dataset_zero_zil(ds, tx);
791 dsl_dataset_rele(ds, FTAG);
792 }
793
794 return (dsobj);
795 }
796
797 /*
798 * The unique space in the head dataset can be calculated by subtracting
799 * the space used in the most recent snapshot, that is still being used
800 * in this file system, from the space currently in use. To figure out
801 * the space in the most recent snapshot still in use, we need to take
802 * the total space used in the snapshot and subtract out the space that
803 * has been freed up since the snapshot was taken.
804 */
805 void
806 dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds)
807 {
808 uint64_t mrs_used;
809 uint64_t dlused, dlcomp, dluncomp;
810
811 ASSERT(!dsl_dataset_is_snapshot(ds));
812
813 if (ds->ds_phys->ds_prev_snap_obj != 0)
814 mrs_used = ds->ds_prev->ds_phys->ds_referenced_bytes;
815 else
816 mrs_used = 0;
817
818 dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp);
819
820 ASSERT3U(dlused, <=, mrs_used);
821 ds->ds_phys->ds_unique_bytes =
822 ds->ds_phys->ds_referenced_bytes - (mrs_used - dlused);
823
824 if (spa_version(ds->ds_dir->dd_pool->dp_spa) >=
825 SPA_VERSION_UNIQUE_ACCURATE)
826 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
827 }
828
829 void
830 dsl_dataset_remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj,
831 dmu_tx_t *tx)
832 {
833 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
834 uint64_t count;
835 int err;
836
837 ASSERT(ds->ds_phys->ds_num_children >= 2);
838 err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx);
839 /*
840 * The err should not be ENOENT, but a bug in a previous version
841 * of the code could cause upgrade_clones_cb() to not set
842 * ds_next_snap_obj when it should, leading to a missing entry.
843 * If we knew that the pool was created after
844 * SPA_VERSION_NEXT_CLONES, we could assert that it isn't
845 * ENOENT. However, at least we can check that we don't have
846 * too many entries in the next_clones_obj even after failing to
847 * remove this one.
848 */
849 if (err != ENOENT)
850 VERIFY0(err);
851 ASSERT0(zap_count(mos, ds->ds_phys->ds_next_clones_obj,
852 &count));
853 ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2);
854 }
855
856
857 blkptr_t *
858 dsl_dataset_get_blkptr(dsl_dataset_t *ds)
859 {
860 return (&ds->ds_phys->ds_bp);
861 }
862
863 void
864 dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx)
865 {
866 ASSERT(dmu_tx_is_syncing(tx));
867 /* If it's the meta-objset, set dp_meta_rootbp */
868 if (ds == NULL) {
869 tx->tx_pool->dp_meta_rootbp = *bp;
870 } else {
871 dmu_buf_will_dirty(ds->ds_dbuf, tx);
872 ds->ds_phys->ds_bp = *bp;
873 }
874 }
875
876 spa_t *
877 dsl_dataset_get_spa(dsl_dataset_t *ds)
878 {
879 return (ds->ds_dir->dd_pool->dp_spa);
880 }
881
882 void
883 dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx)
884 {
885 dsl_pool_t *dp;
886
887 if (ds == NULL) /* this is the meta-objset */
888 return;
889
890 ASSERT(ds->ds_objset != NULL);
891
892 if (ds->ds_phys->ds_next_snap_obj != 0)
893 panic("dirtying snapshot!");
894
895 dp = ds->ds_dir->dd_pool;
896
897 if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg)) {
898 /* up the hold count until we can be written out */
899 dmu_buf_add_ref(ds->ds_dbuf, ds);
900 }
901 }
902
903 boolean_t
904 dsl_dataset_is_dirty(dsl_dataset_t *ds)
905 {
906 for (int t = 0; t < TXG_SIZE; t++) {
907 if (txg_list_member(&ds->ds_dir->dd_pool->dp_dirty_datasets,
908 ds, t))
909 return (B_TRUE);
910 }
911 return (B_FALSE);
912 }
913
914 static int
915 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx)
916 {
917 uint64_t asize;
918
919 if (!dmu_tx_is_syncing(tx))
920 return (0);
921
922 /*
923 * If there's an fs-only reservation, any blocks that might become
924 * owned by the snapshot dataset must be accommodated by space
925 * outside of the reservation.
926 */
927 ASSERT(ds->ds_reserved == 0 || DS_UNIQUE_IS_ACCURATE(ds));
928 asize = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
929 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
930 return (SET_ERROR(ENOSPC));
931
932 /*
933 * Propagate any reserved space for this snapshot to other
934 * snapshot checks in this sync group.
935 */
936 if (asize > 0)
937 dsl_dir_willuse_space(ds->ds_dir, asize, tx);
938
939 return (0);
940 }
941
942 typedef struct dsl_dataset_snapshot_arg {
943 nvlist_t *ddsa_snaps;
944 nvlist_t *ddsa_props;
945 nvlist_t *ddsa_errors;
946 } dsl_dataset_snapshot_arg_t;
947
948 int
949 dsl_dataset_snapshot_check_impl(dsl_dataset_t *ds, const char *snapname,
950 dmu_tx_t *tx, boolean_t recv)
951 {
952 int error;
953 uint64_t value;
954
955 ds->ds_trysnap_txg = tx->tx_txg;
956
957 if (!dmu_tx_is_syncing(tx))
958 return (0);
959
960 /*
961 * We don't allow multiple snapshots of the same txg. If there
962 * is already one, try again.
963 */
964 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg)
965 return (SET_ERROR(EAGAIN));
966
967 /*
968 * Check for conflicting snapshot name.
969 */
970 error = dsl_dataset_snap_lookup(ds, snapname, &value);
971 if (error == 0)
972 return (SET_ERROR(EEXIST));
973 if (error != ENOENT)
974 return (error);
975
976 /*
977 * We don't allow taking snapshots of inconsistent datasets, such as
978 * those into which we are currently receiving. However, if we are
979 * creating this snapshot as part of a receive, this check will be
980 * executed atomically with respect to the completion of the receive
981 * itself but prior to the clearing of DS_FLAG_INCONSISTENT; in this
982 * case we ignore this, knowing it will be fixed up for us shortly in
983 * dmu_recv_end_sync().
984 */
985 if (!recv && DS_IS_INCONSISTENT(ds))
986 return (SET_ERROR(EBUSY));
987
988 error = dsl_dataset_snapshot_reserve_space(ds, tx);
989 if (error != 0)
990 return (error);
991
992 return (0);
993 }
994
995 static int
996 dsl_dataset_snapshot_check(void *arg, dmu_tx_t *tx)
997 {
998 dsl_dataset_snapshot_arg_t *ddsa = arg;
999 dsl_pool_t *dp = dmu_tx_pool(tx);
1000 nvpair_t *pair;
1001 int rv = 0;
1002
1003 for (pair = nvlist_next_nvpair(ddsa->ddsa_snaps, NULL);
1004 pair != NULL; pair = nvlist_next_nvpair(ddsa->ddsa_snaps, pair)) {
1005 int error = 0;
1006 dsl_dataset_t *ds;
1007 char *name, *atp;
1008 char dsname[MAXNAMELEN];
1009
1010 name = nvpair_name(pair);
1011 if (strlen(name) >= MAXNAMELEN)
1012 error = SET_ERROR(ENAMETOOLONG);
1013 if (error == 0) {
1014 atp = strchr(name, '@');
1015 if (atp == NULL)
1016 error = SET_ERROR(EINVAL);
1017 if (error == 0)
1018 (void) strlcpy(dsname, name, atp - name + 1);
1019 }
1020 if (error == 0)
1021 error = dsl_dataset_hold(dp, dsname, FTAG, &ds);
1022 if (error == 0) {
1023 error = dsl_dataset_snapshot_check_impl(ds,
1024 atp + 1, tx, B_FALSE);
1025 dsl_dataset_rele(ds, FTAG);
1026 }
1027
1028 if (error != 0) {
1029 if (ddsa->ddsa_errors != NULL) {
1030 fnvlist_add_int32(ddsa->ddsa_errors,
1031 name, error);
1032 }
1033 rv = error;
1034 }
1035 }
1036 return (rv);
1037 }
1038
1039 void
1040 dsl_dataset_snapshot_sync_impl(dsl_dataset_t *ds, const char *snapname,
1041 dmu_tx_t *tx)
1042 {
1043 static zil_header_t zero_zil;
1044
1045 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1046 dmu_buf_t *dbuf;
1047 dsl_dataset_phys_t *dsphys;
1048 uint64_t dsobj, crtxg;
1049 objset_t *mos = dp->dp_meta_objset;
1050 objset_t *os;
1051
1052 ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
1053
1054 /*
1055 * If we are on an old pool, the zil must not be active, in which
1056 * case it will be zeroed. Usually zil_suspend() accomplishes this.
1057 */
1058 ASSERT(spa_version(dmu_tx_pool(tx)->dp_spa) >= SPA_VERSION_FAST_SNAP ||
1059 dmu_objset_from_ds(ds, &os) != 0 ||
1060 bcmp(&os->os_phys->os_zil_header, &zero_zil,
1061 sizeof (zero_zil)) == 0);
1062
1063
1064 /*
1065 * The origin's ds_creation_txg has to be < TXG_INITIAL
1066 */
1067 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0)
1068 crtxg = 1;
1069 else
1070 crtxg = tx->tx_txg;
1071
1072 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
1073 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
1074 VERIFY0(dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
1075 dmu_buf_will_dirty(dbuf, tx);
1076 dsphys = dbuf->db_data;
1077 bzero(dsphys, sizeof (dsl_dataset_phys_t));
1078 dsphys->ds_dir_obj = ds->ds_dir->dd_object;
1079 dsphys->ds_fsid_guid = unique_create();
1080 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
1081 sizeof (dsphys->ds_guid));
1082 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj;
1083 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg;
1084 dsphys->ds_next_snap_obj = ds->ds_object;
1085 dsphys->ds_num_children = 1;
1086 dsphys->ds_creation_time = gethrestime_sec();
1087 dsphys->ds_creation_txg = crtxg;
1088 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj;
1089 dsphys->ds_referenced_bytes = ds->ds_phys->ds_referenced_bytes;
1090 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes;
1091 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes;
1092 dsphys->ds_flags = ds->ds_phys->ds_flags;
1093 dsphys->ds_bp = ds->ds_phys->ds_bp;
1094 dmu_buf_rele(dbuf, FTAG);
1095
1096 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0);
1097 if (ds->ds_prev) {
1098 uint64_t next_clones_obj =
1099 ds->ds_prev->ds_phys->ds_next_clones_obj;
1100 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj ==
1101 ds->ds_object ||
1102 ds->ds_prev->ds_phys->ds_num_children > 1);
1103 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) {
1104 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
1105 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
1106 ds->ds_prev->ds_phys->ds_creation_txg);
1107 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj;
1108 } else if (next_clones_obj != 0) {
1109 dsl_dataset_remove_from_next_clones(ds->ds_prev,
1110 dsphys->ds_next_snap_obj, tx);
1111 VERIFY0(zap_add_int(mos,
1112 next_clones_obj, dsobj, tx));
1113 }
1114 }
1115
1116 /*
1117 * If we have a reference-reservation on this dataset, we will
1118 * need to increase the amount of refreservation being charged
1119 * since our unique space is going to zero.
1120 */
1121 if (ds->ds_reserved) {
1122 int64_t delta;
1123 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
1124 delta = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
1125 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV,
1126 delta, 0, 0, tx);
1127 }
1128
1129 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1130 ds->ds_phys->ds_deadlist_obj = dsl_deadlist_clone(&ds->ds_deadlist,
1131 UINT64_MAX, ds->ds_phys->ds_prev_snap_obj, tx);
1132 dsl_deadlist_close(&ds->ds_deadlist);
1133 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj);
1134 dsl_deadlist_add_key(&ds->ds_deadlist,
1135 ds->ds_phys->ds_prev_snap_txg, tx);
1136
1137 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg);
1138 ds->ds_phys->ds_prev_snap_obj = dsobj;
1139 ds->ds_phys->ds_prev_snap_txg = crtxg;
1140 ds->ds_phys->ds_unique_bytes = 0;
1141 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
1142 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
1143
1144 VERIFY0(zap_add(mos, ds->ds_phys->ds_snapnames_zapobj,
1145 snapname, 8, 1, &dsobj, tx));
1146
1147 if (ds->ds_prev)
1148 dsl_dataset_rele(ds->ds_prev, ds);
1149 VERIFY0(dsl_dataset_hold_obj(dp,
1150 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev));
1151
1152 dsl_scan_ds_snapshotted(ds, tx);
1153
1154 dsl_dir_snap_cmtime_update(ds->ds_dir);
1155
1156 spa_history_log_internal_ds(ds->ds_prev, "snapshot", tx, "");
1157 }
1158
1159 static void
1160 dsl_dataset_snapshot_sync(void *arg, dmu_tx_t *tx)
1161 {
1162 dsl_dataset_snapshot_arg_t *ddsa = arg;
1163 dsl_pool_t *dp = dmu_tx_pool(tx);
1164 nvpair_t *pair;
1165
1166 for (pair = nvlist_next_nvpair(ddsa->ddsa_snaps, NULL);
1167 pair != NULL; pair = nvlist_next_nvpair(ddsa->ddsa_snaps, pair)) {
1168 dsl_dataset_t *ds;
1169 char *name, *atp;
1170 char dsname[MAXNAMELEN];
1171
1172 name = nvpair_name(pair);
1173 atp = strchr(name, '@');
1174 (void) strlcpy(dsname, name, atp - name + 1);
1175 VERIFY0(dsl_dataset_hold(dp, dsname, FTAG, &ds));
1176
1177 dsl_dataset_snapshot_sync_impl(ds, atp + 1, tx);
1178 if (ddsa->ddsa_props != NULL) {
1179 dsl_props_set_sync_impl(ds->ds_prev,
1180 ZPROP_SRC_LOCAL, ddsa->ddsa_props, tx);
1181 }
1182 dsl_dataset_rele(ds, FTAG);
1183 }
1184 }
1185
1186 /*
1187 * The snapshots must all be in the same pool.
1188 * All-or-nothing: if there are any failures, nothing will be modified.
1189 */
1190 int
1191 dsl_dataset_snapshot(nvlist_t *snaps, nvlist_t *props, nvlist_t *errors)
1192 {
1193 dsl_dataset_snapshot_arg_t ddsa;
1194 nvpair_t *pair;
1195 boolean_t needsuspend;
1196 int error;
1197 spa_t *spa;
1198 char *firstname;
1199 nvlist_t *suspended = NULL;
1200
1201 pair = nvlist_next_nvpair(snaps, NULL);
1202 if (pair == NULL)
1203 return (0);
1204 firstname = nvpair_name(pair);
1205
1206 error = spa_open(firstname, &spa, FTAG);
1207 if (error != 0)
1208 return (error);
1209 needsuspend = (spa_version(spa) < SPA_VERSION_FAST_SNAP);
1210 spa_close(spa, FTAG);
1211
1212 if (needsuspend) {
1213 suspended = fnvlist_alloc();
1214 for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL;
1215 pair = nvlist_next_nvpair(snaps, pair)) {
1216 char fsname[MAXNAMELEN];
1217 char *snapname = nvpair_name(pair);
1218 char *atp;
1219 void *cookie;
1220
1221 atp = strchr(snapname, '@');
1222 if (atp == NULL) {
1223 error = SET_ERROR(EINVAL);
1224 break;
1225 }
1226 (void) strlcpy(fsname, snapname, atp - snapname + 1);
1227
1228 error = zil_suspend(fsname, &cookie);
1229 if (error != 0)
1230 break;
1231 fnvlist_add_uint64(suspended, fsname,
1232 (uintptr_t)cookie);
1233 }
1234 }
1235
1236 ddsa.ddsa_snaps = snaps;
1237 ddsa.ddsa_props = props;
1238 ddsa.ddsa_errors = errors;
1239
1240 if (error == 0) {
1241 error = dsl_sync_task(firstname, dsl_dataset_snapshot_check,
1242 dsl_dataset_snapshot_sync, &ddsa,
1243 fnvlist_num_pairs(snaps) * 3);
1244 }
1245
1246 if (suspended != NULL) {
1247 for (pair = nvlist_next_nvpair(suspended, NULL); pair != NULL;
1248 pair = nvlist_next_nvpair(suspended, pair)) {
1249 zil_resume((void *)(uintptr_t)
1250 fnvpair_value_uint64(pair));
1251 }
1252 fnvlist_free(suspended);
1253 }
1254
1255 return (error);
1256 }
1257
1258 typedef struct dsl_dataset_snapshot_tmp_arg {
1259 const char *ddsta_fsname;
1260 const char *ddsta_snapname;
1261 minor_t ddsta_cleanup_minor;
1262 const char *ddsta_htag;
1263 } dsl_dataset_snapshot_tmp_arg_t;
1264
1265 static int
1266 dsl_dataset_snapshot_tmp_check(void *arg, dmu_tx_t *tx)
1267 {
1268 dsl_dataset_snapshot_tmp_arg_t *ddsta = arg;
1269 dsl_pool_t *dp = dmu_tx_pool(tx);
1270 dsl_dataset_t *ds;
1271 int error;
1272
1273 error = dsl_dataset_hold(dp, ddsta->ddsta_fsname, FTAG, &ds);
1274 if (error != 0)
1275 return (error);
1276
1277 error = dsl_dataset_snapshot_check_impl(ds, ddsta->ddsta_snapname,
1278 tx, B_FALSE);
1279 if (error != 0) {
1280 dsl_dataset_rele(ds, FTAG);
1281 return (error);
1282 }
1283
1284 if (spa_version(dp->dp_spa) < SPA_VERSION_USERREFS) {
1285 dsl_dataset_rele(ds, FTAG);
1286 return (SET_ERROR(ENOTSUP));
1287 }
1288 error = dsl_dataset_user_hold_check_one(NULL, ddsta->ddsta_htag,
1289 B_TRUE, tx);
1290 if (error != 0) {
1291 dsl_dataset_rele(ds, FTAG);
1292 return (error);
1293 }
1294
1295 dsl_dataset_rele(ds, FTAG);
1296 return (0);
1297 }
1298
1299 static void
1300 dsl_dataset_snapshot_tmp_sync(void *arg, dmu_tx_t *tx)
1301 {
1302 dsl_dataset_snapshot_tmp_arg_t *ddsta = arg;
1303 dsl_pool_t *dp = dmu_tx_pool(tx);
1304 dsl_dataset_t *ds;
1305
1306 VERIFY0(dsl_dataset_hold(dp, ddsta->ddsta_fsname, FTAG, &ds));
1307
1308 dsl_dataset_snapshot_sync_impl(ds, ddsta->ddsta_snapname, tx);
1309 dsl_dataset_user_hold_sync_one(ds->ds_prev, ddsta->ddsta_htag,
1310 ddsta->ddsta_cleanup_minor, gethrestime_sec(), tx);
1311 dsl_destroy_snapshot_sync_impl(ds->ds_prev, B_TRUE, tx);
1312
1313 dsl_dataset_rele(ds, FTAG);
1314 }
1315
1316 int
1317 dsl_dataset_snapshot_tmp(const char *fsname, const char *snapname,
1318 minor_t cleanup_minor, const char *htag)
1319 {
1320 dsl_dataset_snapshot_tmp_arg_t ddsta;
1321 int error;
1322 spa_t *spa;
1323 boolean_t needsuspend;
1324 void *cookie;
1325
1326 ddsta.ddsta_fsname = fsname;
1327 ddsta.ddsta_snapname = snapname;
1328 ddsta.ddsta_cleanup_minor = cleanup_minor;
1329 ddsta.ddsta_htag = htag;
1330
1331 error = spa_open(fsname, &spa, FTAG);
1332 if (error != 0)
1333 return (error);
1334 needsuspend = (spa_version(spa) < SPA_VERSION_FAST_SNAP);
1335 spa_close(spa, FTAG);
1336
1337 if (needsuspend) {
1338 error = zil_suspend(fsname, &cookie);
1339 if (error != 0)
1340 return (error);
1341 }
1342
1343 error = dsl_sync_task(fsname, dsl_dataset_snapshot_tmp_check,
1344 dsl_dataset_snapshot_tmp_sync, &ddsta, 3);
1345
1346 if (needsuspend)
1347 zil_resume(cookie);
1348 return (error);
1349 }
1350
1351
1352 void
1353 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx)
1354 {
1355 ASSERT(dmu_tx_is_syncing(tx));
1356 ASSERT(ds->ds_objset != NULL);
1357 ASSERT(ds->ds_phys->ds_next_snap_obj == 0);
1358
1359 /*
1360 * in case we had to change ds_fsid_guid when we opened it,
1361 * sync it out now.
1362 */
1363 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1364 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid;
1365
1366 dmu_objset_sync(ds->ds_objset, zio, tx);
1367 }
1368
1369 static void
1370 get_clones_stat(dsl_dataset_t *ds, nvlist_t *nv)
1371 {
1372 uint64_t count = 0;
1373 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1374 zap_cursor_t zc;
1375 zap_attribute_t za;
1376 nvlist_t *propval = fnvlist_alloc();
1377 nvlist_t *val = fnvlist_alloc();
1378
1379 ASSERT(dsl_pool_config_held(ds->ds_dir->dd_pool));
1380
1381 /*
1382 * There may be missing entries in ds_next_clones_obj
1383 * due to a bug in a previous version of the code.
1384 * Only trust it if it has the right number of entries.
1385 */
1386 if (ds->ds_phys->ds_next_clones_obj != 0) {
1387 ASSERT0(zap_count(mos, ds->ds_phys->ds_next_clones_obj,
1388 &count));
1389 }
1390 if (count != ds->ds_phys->ds_num_children - 1)
1391 goto fail;
1392 for (zap_cursor_init(&zc, mos, ds->ds_phys->ds_next_clones_obj);
1393 zap_cursor_retrieve(&zc, &za) == 0;
1394 zap_cursor_advance(&zc)) {
1395 dsl_dataset_t *clone;
1396 char buf[ZFS_MAXNAMELEN];
1397 VERIFY0(dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
1398 za.za_first_integer, FTAG, &clone));
1399 dsl_dir_name(clone->ds_dir, buf);
1400 fnvlist_add_boolean(val, buf);
1401 dsl_dataset_rele(clone, FTAG);
1402 }
1403 zap_cursor_fini(&zc);
1404 fnvlist_add_nvlist(propval, ZPROP_VALUE, val);
1405 fnvlist_add_nvlist(nv, zfs_prop_to_name(ZFS_PROP_CLONES), propval);
1406 fail:
1407 nvlist_free(val);
1408 nvlist_free(propval);
1409 }
1410
1411 void
1412 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv)
1413 {
1414 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1415 uint64_t refd, avail, uobjs, aobjs, ratio;
1416
1417 ASSERT(dsl_pool_config_held(dp));
1418
1419 ratio = ds->ds_phys->ds_compressed_bytes == 0 ? 100 :
1420 (ds->ds_phys->ds_uncompressed_bytes * 100 /
1421 ds->ds_phys->ds_compressed_bytes);
1422
1423 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRATIO, ratio);
1424 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_LOGICALREFERENCED,
1425 ds->ds_phys->ds_uncompressed_bytes);
1426
1427 if (dsl_dataset_is_snapshot(ds)) {
1428 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, ratio);
1429 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED,
1430 ds->ds_phys->ds_unique_bytes);
1431 get_clones_stat(ds, nv);
1432 } else {
1433 dsl_dir_stats(ds->ds_dir, nv);
1434 }
1435
1436 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs);
1437 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail);
1438 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd);
1439
1440 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION,
1441 ds->ds_phys->ds_creation_time);
1442 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG,
1443 ds->ds_phys->ds_creation_txg);
1444 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA,
1445 ds->ds_quota);
1446 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION,
1447 ds->ds_reserved);
1448 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID,
1449 ds->ds_phys->ds_guid);
1450 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE,
1451 ds->ds_phys->ds_unique_bytes);
1452 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID,
1453 ds->ds_object);
1454 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS,
1455 ds->ds_userrefs);
1456 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY,
1457 DS_IS_DEFER_DESTROY(ds) ? 1 : 0);
1458
1459 if (ds->ds_phys->ds_prev_snap_obj != 0) {
1460 uint64_t written, comp, uncomp;
1461 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1462 dsl_dataset_t *prev;
1463
1464 int err = dsl_dataset_hold_obj(dp,
1465 ds->ds_phys->ds_prev_snap_obj, FTAG, &prev);
1466 if (err == 0) {
1467 err = dsl_dataset_space_written(prev, ds, &written,
1468 &comp, &uncomp);
1469 dsl_dataset_rele(prev, FTAG);
1470 if (err == 0) {
1471 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_WRITTEN,
1472 written);
1473 }
1474 }
1475 }
1476 }
1477
1478 void
1479 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat)
1480 {
1481 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1482 ASSERT(dsl_pool_config_held(dp));
1483
1484 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg;
1485 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT;
1486 stat->dds_guid = ds->ds_phys->ds_guid;
1487 stat->dds_origin[0] = '\0';
1488 if (dsl_dataset_is_snapshot(ds)) {
1489 stat->dds_is_snapshot = B_TRUE;
1490 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1;
1491 } else {
1492 stat->dds_is_snapshot = B_FALSE;
1493 stat->dds_num_clones = 0;
1494
1495 if (dsl_dir_is_clone(ds->ds_dir)) {
1496 dsl_dataset_t *ods;
1497
1498 VERIFY0(dsl_dataset_hold_obj(dp,
1499 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods));
1500 dsl_dataset_name(ods, stat->dds_origin);
1501 dsl_dataset_rele(ods, FTAG);
1502 }
1503 }
1504 }
1505
1506 uint64_t
1507 dsl_dataset_fsid_guid(dsl_dataset_t *ds)
1508 {
1509 return (ds->ds_fsid_guid);
1510 }
1511
1512 void
1513 dsl_dataset_space(dsl_dataset_t *ds,
1514 uint64_t *refdbytesp, uint64_t *availbytesp,
1515 uint64_t *usedobjsp, uint64_t *availobjsp)
1516 {
1517 *refdbytesp = ds->ds_phys->ds_referenced_bytes;
1518 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE);
1519 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes)
1520 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes;
1521 if (ds->ds_quota != 0) {
1522 /*
1523 * Adjust available bytes according to refquota
1524 */
1525 if (*refdbytesp < ds->ds_quota)
1526 *availbytesp = MIN(*availbytesp,
1527 ds->ds_quota - *refdbytesp);
1528 else
1529 *availbytesp = 0;
1530 }
1531 *usedobjsp = ds->ds_phys->ds_bp.blk_fill;
1532 *availobjsp = DN_MAX_OBJECT - *usedobjsp;
1533 }
1534
1535 boolean_t
1536 dsl_dataset_modified_since_snap(dsl_dataset_t *ds, dsl_dataset_t *snap)
1537 {
1538 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1539
1540 ASSERT(dsl_pool_config_held(dp));
1541 if (snap == NULL)
1542 return (B_FALSE);
1543 if (ds->ds_phys->ds_bp.blk_birth >
1544 snap->ds_phys->ds_creation_txg) {
1545 objset_t *os, *os_snap;
1546 /*
1547 * It may be that only the ZIL differs, because it was
1548 * reset in the head. Don't count that as being
1549 * modified.
1550 */
1551 if (dmu_objset_from_ds(ds, &os) != 0)
1552 return (B_TRUE);
1553 if (dmu_objset_from_ds(snap, &os_snap) != 0)
1554 return (B_TRUE);
1555 return (bcmp(&os->os_phys->os_meta_dnode,
1556 &os_snap->os_phys->os_meta_dnode,
1557 sizeof (os->os_phys->os_meta_dnode)) != 0);
1558 }
1559 return (B_FALSE);
1560 }
1561
1562 typedef struct dsl_dataset_rename_snapshot_arg {
1563 const char *ddrsa_fsname;
1564 const char *ddrsa_oldsnapname;
1565 const char *ddrsa_newsnapname;
1566 boolean_t ddrsa_recursive;
1567 dmu_tx_t *ddrsa_tx;
1568 } dsl_dataset_rename_snapshot_arg_t;
1569
1570 /* ARGSUSED */
1571 static int
1572 dsl_dataset_rename_snapshot_check_impl(dsl_pool_t *dp,
1573 dsl_dataset_t *hds, void *arg)
1574 {
1575 dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
1576 int error;
1577 uint64_t val;
1578
1579 error = dsl_dataset_snap_lookup(hds, ddrsa->ddrsa_oldsnapname, &val);
1580 if (error != 0) {
1581 /* ignore nonexistent snapshots */
1582 return (error == ENOENT ? 0 : error);
1583 }
1584
1585 /* new name should not exist */
1586 error = dsl_dataset_snap_lookup(hds, ddrsa->ddrsa_newsnapname, &val);
1587 if (error == 0)
1588 error = SET_ERROR(EEXIST);
1589 else if (error == ENOENT)
1590 error = 0;
1591
1592 /* dataset name + 1 for the "@" + the new snapshot name must fit */
1593 if (dsl_dir_namelen(hds->ds_dir) + 1 +
1594 strlen(ddrsa->ddrsa_newsnapname) >= MAXNAMELEN)
1595 error = SET_ERROR(ENAMETOOLONG);
1596
1597 return (error);
1598 }
1599
1600 static int
1601 dsl_dataset_rename_snapshot_check(void *arg, dmu_tx_t *tx)
1602 {
1603 dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
1604 dsl_pool_t *dp = dmu_tx_pool(tx);
1605 dsl_dataset_t *hds;
1606 int error;
1607
1608 error = dsl_dataset_hold(dp, ddrsa->ddrsa_fsname, FTAG, &hds);
1609 if (error != 0)
1610 return (error);
1611
1612 if (ddrsa->ddrsa_recursive) {
1613 error = dmu_objset_find_dp(dp, hds->ds_dir->dd_object,
1614 dsl_dataset_rename_snapshot_check_impl, ddrsa,
1615 DS_FIND_CHILDREN);
1616 } else {
1617 error = dsl_dataset_rename_snapshot_check_impl(dp, hds, ddrsa);
1618 }
1619 dsl_dataset_rele(hds, FTAG);
1620 return (error);
1621 }
1622
1623 static int
1624 dsl_dataset_rename_snapshot_sync_impl(dsl_pool_t *dp,
1625 dsl_dataset_t *hds, void *arg)
1626 {
1627 dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
1628 dsl_dataset_t *ds;
1629 uint64_t val;
1630 dmu_tx_t *tx = ddrsa->ddrsa_tx;
1631 int error;
1632
1633 error = dsl_dataset_snap_lookup(hds, ddrsa->ddrsa_oldsnapname, &val);
1634 ASSERT(error == 0 || error == ENOENT);
1635 if (error == ENOENT) {
1636 /* ignore nonexistent snapshots */
1637 return (0);
1638 }
1639
1640 VERIFY0(dsl_dataset_hold_obj(dp, val, FTAG, &ds));
1641
1642 /* log before we change the name */
1643 spa_history_log_internal_ds(ds, "rename", tx,
1644 "-> @%s", ddrsa->ddrsa_newsnapname);
1645
1646 VERIFY0(dsl_dataset_snap_remove(hds, ddrsa->ddrsa_oldsnapname, tx));
1647 mutex_enter(&ds->ds_lock);
1648 (void) strcpy(ds->ds_snapname, ddrsa->ddrsa_newsnapname);
1649 mutex_exit(&ds->ds_lock);
1650 VERIFY0(zap_add(dp->dp_meta_objset, hds->ds_phys->ds_snapnames_zapobj,
1651 ds->ds_snapname, 8, 1, &ds->ds_object, tx));
1652
1653 dsl_dataset_rele(ds, FTAG);
1654 return (0);
1655 }
1656
1657 static void
1658 dsl_dataset_rename_snapshot_sync(void *arg, dmu_tx_t *tx)
1659 {
1660 dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
1661 dsl_pool_t *dp = dmu_tx_pool(tx);
1662 dsl_dataset_t *hds;
1663
1664 VERIFY0(dsl_dataset_hold(dp, ddrsa->ddrsa_fsname, FTAG, &hds));
1665 ddrsa->ddrsa_tx = tx;
1666 if (ddrsa->ddrsa_recursive) {
1667 VERIFY0(dmu_objset_find_dp(dp, hds->ds_dir->dd_object,
1668 dsl_dataset_rename_snapshot_sync_impl, ddrsa,
1669 DS_FIND_CHILDREN));
1670 } else {
1671 VERIFY0(dsl_dataset_rename_snapshot_sync_impl(dp, hds, ddrsa));
1672 }
1673 dsl_dataset_rele(hds, FTAG);
1674 }
1675
1676 int
1677 dsl_dataset_rename_snapshot(const char *fsname,
1678 const char *oldsnapname, const char *newsnapname, boolean_t recursive)
1679 {
1680 dsl_dataset_rename_snapshot_arg_t ddrsa;
1681
1682 ddrsa.ddrsa_fsname = fsname;
1683 ddrsa.ddrsa_oldsnapname = oldsnapname;
1684 ddrsa.ddrsa_newsnapname = newsnapname;
1685 ddrsa.ddrsa_recursive = recursive;
1686
1687 return (dsl_sync_task(fsname, dsl_dataset_rename_snapshot_check,
1688 dsl_dataset_rename_snapshot_sync, &ddrsa, 1));
1689 }
1690
1691 /*
1692 * If we're doing an ownership handoff, we need to make sure that there is
1693 * only one long hold on the dataset. We're not allowed to change anything here
1694 * so we don't permanently release the long hold or regular hold here. We want
1695 * to do this only when syncing to avoid the dataset unexpectedly going away
1696 * when we release the long hold.
1697 */
1698 static int
1699 dsl_dataset_handoff_check(dsl_dataset_t *ds, void *owner, dmu_tx_t *tx)
1700 {
1701 boolean_t held;
1702
1703 if (!dmu_tx_is_syncing(tx))
1704 return (0);
1705
1706 if (owner != NULL) {
1707 VERIFY3P(ds->ds_owner, ==, owner);
1708 dsl_dataset_long_rele(ds, owner);
1709 }
1710
1711 held = dsl_dataset_long_held(ds);
1712
1713 if (owner != NULL)
1714 dsl_dataset_long_hold(ds, owner);
1715
1716 if (held)
1717 return (SET_ERROR(EBUSY));
1718
1719 return (0);
1720 }
1721
1722 typedef struct dsl_dataset_rollback_arg {
1723 const char *ddra_fsname;
1724 void *ddra_owner;
1725 } dsl_dataset_rollback_arg_t;
1726
1727 static int
1728 dsl_dataset_rollback_check(void *arg, dmu_tx_t *tx)
1729 {
1730 dsl_dataset_rollback_arg_t *ddra = arg;
1731 dsl_pool_t *dp = dmu_tx_pool(tx);
1732 dsl_dataset_t *ds;
1733 int64_t unused_refres_delta;
1734 int error;
1735
1736 error = dsl_dataset_hold(dp, ddra->ddra_fsname, FTAG, &ds);
1737 if (error != 0)
1738 return (error);
1739
1740 /* must not be a snapshot */
1741 if (dsl_dataset_is_snapshot(ds)) {
1742 dsl_dataset_rele(ds, FTAG);
1743 return (SET_ERROR(EINVAL));
1744 }
1745
1746 /* must have a most recent snapshot */
1747 if (ds->ds_phys->ds_prev_snap_txg < TXG_INITIAL) {
1748 dsl_dataset_rele(ds, FTAG);
1749 return (SET_ERROR(EINVAL));
1750 }
1751
1752 error = dsl_dataset_handoff_check(ds, ddra->ddra_owner, tx);
1753 if (error != 0) {
1754 dsl_dataset_rele(ds, FTAG);
1755 return (error);
1756 }
1757
1758 /*
1759 * Check if the snap we are rolling back to uses more than
1760 * the refquota.
1761 */
1762 if (ds->ds_quota != 0 &&
1763 ds->ds_prev->ds_phys->ds_referenced_bytes > ds->ds_quota) {
1764 dsl_dataset_rele(ds, FTAG);
1765 return (SET_ERROR(EDQUOT));
1766 }
1767
1768 /*
1769 * When we do the clone swap, we will temporarily use more space
1770 * due to the refreservation (the head will no longer have any
1771 * unique space, so the entire amount of the refreservation will need
1772 * to be free). We will immediately destroy the clone, freeing
1773 * this space, but the freeing happens over many txg's.
1774 */
1775 unused_refres_delta = (int64_t)MIN(ds->ds_reserved,
1776 ds->ds_phys->ds_unique_bytes);
1777
1778 if (unused_refres_delta > 0 &&
1779 unused_refres_delta >
1780 dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE)) {
1781 dsl_dataset_rele(ds, FTAG);
1782 return (SET_ERROR(ENOSPC));
1783 }
1784
1785 dsl_dataset_rele(ds, FTAG);
1786 return (0);
1787 }
1788
1789 static void
1790 dsl_dataset_rollback_sync(void *arg, dmu_tx_t *tx)
1791 {
1792 dsl_dataset_rollback_arg_t *ddra = arg;
1793 dsl_pool_t *dp = dmu_tx_pool(tx);
1794 dsl_dataset_t *ds, *clone;
1795 uint64_t cloneobj;
1796
1797 VERIFY0(dsl_dataset_hold(dp, ddra->ddra_fsname, FTAG, &ds));
1798
1799 cloneobj = dsl_dataset_create_sync(ds->ds_dir, "%rollback",
1800 ds->ds_prev, DS_CREATE_FLAG_NODIRTY, kcred, tx);
1801
1802 VERIFY0(dsl_dataset_hold_obj(dp, cloneobj, FTAG, &clone));
1803
1804 dsl_dataset_clone_swap_sync_impl(clone, ds, tx);
1805 dsl_dataset_zero_zil(ds, tx);
1806
1807 dsl_destroy_head_sync_impl(clone, tx);
1808
1809 dsl_dataset_rele(clone, FTAG);
1810 dsl_dataset_rele(ds, FTAG);
1811 }
1812
1813 /*
1814 * If owner != NULL:
1815 *
1816 * - The existing dataset MUST be owned by the specified owner at entry
1817 * - Upon return, dataset will still be held by the same owner, whether we
1818 * succeed or not.
1819 *
1820 * This mode is required any time the existing filesystem is mounted. See
1821 * notes above zfs_suspend_fs() for further details.
1822 */
1823 int
1824 dsl_dataset_rollback(const char *fsname, void *owner)
1825 {
1826 dsl_dataset_rollback_arg_t ddra;
1827
1828 ddra.ddra_fsname = fsname;
1829 ddra.ddra_owner = owner;
1830
1831 return (dsl_sync_task(fsname, dsl_dataset_rollback_check,
1832 dsl_dataset_rollback_sync, (void *)&ddra, 1));
1833 }
1834
1835 struct promotenode {
1836 list_node_t link;
1837 dsl_dataset_t *ds;
1838 };
1839
1840 typedef struct dsl_dataset_promote_arg {
1841 const char *ddpa_clonename;
1842 dsl_dataset_t *ddpa_clone;
1843 list_t shared_snaps, origin_snaps, clone_snaps;
1844 dsl_dataset_t *origin_origin; /* origin of the origin */
1845 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap;
1846 char *err_ds;
1847 } dsl_dataset_promote_arg_t;
1848
1849 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep);
1850 static int promote_hold(dsl_dataset_promote_arg_t *ddpa, dsl_pool_t *dp,
1851 void *tag);
1852 static void promote_rele(dsl_dataset_promote_arg_t *ddpa, void *tag);
1853
1854 static int
1855 dsl_dataset_promote_check(void *arg, dmu_tx_t *tx)
1856 {
1857 dsl_dataset_promote_arg_t *ddpa = arg;
1858 dsl_pool_t *dp = dmu_tx_pool(tx);
1859 dsl_dataset_t *hds;
1860 struct promotenode *snap;
1861 dsl_dataset_t *origin_ds;
1862 int err;
1863 uint64_t unused;
1864
1865 err = promote_hold(ddpa, dp, FTAG);
1866 if (err != 0)
1867 return (err);
1868
1869 hds = ddpa->ddpa_clone;
1870
1871 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE) {
1872 promote_rele(ddpa, FTAG);
1873 return (SET_ERROR(EXDEV));
1874 }
1875
1876 /*
1877 * Compute and check the amount of space to transfer. Since this is
1878 * so expensive, don't do the preliminary check.
1879 */
1880 if (!dmu_tx_is_syncing(tx)) {
1881 promote_rele(ddpa, FTAG);
1882 return (0);
1883 }
1884
1885 snap = list_head(&ddpa->shared_snaps);
1886 origin_ds = snap->ds;
1887
1888 /* compute origin's new unique space */
1889 snap = list_tail(&ddpa->clone_snaps);
1890 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
1891 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
1892 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX,
1893 &ddpa->unique, &unused, &unused);
1894
1895 /*
1896 * Walk the snapshots that we are moving
1897 *
1898 * Compute space to transfer. Consider the incremental changes
1899 * to used by each snapshot:
1900 * (my used) = (prev's used) + (blocks born) - (blocks killed)
1901 * So each snapshot gave birth to:
1902 * (blocks born) = (my used) - (prev's used) + (blocks killed)
1903 * So a sequence would look like:
1904 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0)
1905 * Which simplifies to:
1906 * uN + kN + kN-1 + ... + k1 + k0
1907 * Note however, if we stop before we reach the ORIGIN we get:
1908 * uN + kN + kN-1 + ... + kM - uM-1
1909 */
1910 ddpa->used = origin_ds->ds_phys->ds_referenced_bytes;
1911 ddpa->comp = origin_ds->ds_phys->ds_compressed_bytes;
1912 ddpa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes;
1913 for (snap = list_head(&ddpa->shared_snaps); snap;
1914 snap = list_next(&ddpa->shared_snaps, snap)) {
1915 uint64_t val, dlused, dlcomp, dluncomp;
1916 dsl_dataset_t *ds = snap->ds;
1917
1918 /*
1919 * If there are long holds, we won't be able to evict
1920 * the objset.
1921 */
1922 if (dsl_dataset_long_held(ds)) {
1923 err = SET_ERROR(EBUSY);
1924 goto out;
1925 }
1926
1927 /* Check that the snapshot name does not conflict */
1928 VERIFY0(dsl_dataset_get_snapname(ds));
1929 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val);
1930 if (err == 0) {
1931 (void) strcpy(ddpa->err_ds, snap->ds->ds_snapname);
1932 err = SET_ERROR(EEXIST);
1933 goto out;
1934 }
1935 if (err != ENOENT)
1936 goto out;
1937
1938 /* The very first snapshot does not have a deadlist */
1939 if (ds->ds_phys->ds_prev_snap_obj == 0)
1940 continue;
1941
1942 dsl_deadlist_space(&ds->ds_deadlist,
1943 &dlused, &dlcomp, &dluncomp);
1944 ddpa->used += dlused;
1945 ddpa->comp += dlcomp;
1946 ddpa->uncomp += dluncomp;
1947 }
1948
1949 /*
1950 * If we are a clone of a clone then we never reached ORIGIN,
1951 * so we need to subtract out the clone origin's used space.
1952 */
1953 if (ddpa->origin_origin) {
1954 ddpa->used -= ddpa->origin_origin->ds_phys->ds_referenced_bytes;
1955 ddpa->comp -= ddpa->origin_origin->ds_phys->ds_compressed_bytes;
1956 ddpa->uncomp -=
1957 ddpa->origin_origin->ds_phys->ds_uncompressed_bytes;
1958 }
1959
1960 /* Check that there is enough space here */
1961 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir,
1962 ddpa->used);
1963 if (err != 0)
1964 goto out;
1965
1966 /*
1967 * Compute the amounts of space that will be used by snapshots
1968 * after the promotion (for both origin and clone). For each,
1969 * it is the amount of space that will be on all of their
1970 * deadlists (that was not born before their new origin).
1971 */
1972 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
1973 uint64_t space;
1974
1975 /*
1976 * Note, typically this will not be a clone of a clone,
1977 * so dd_origin_txg will be < TXG_INITIAL, so
1978 * these snaplist_space() -> dsl_deadlist_space_range()
1979 * calls will be fast because they do not have to
1980 * iterate over all bps.
1981 */
1982 snap = list_head(&ddpa->origin_snaps);
1983 err = snaplist_space(&ddpa->shared_snaps,
1984 snap->ds->ds_dir->dd_origin_txg, &ddpa->cloneusedsnap);
1985 if (err != 0)
1986 goto out;
1987
1988 err = snaplist_space(&ddpa->clone_snaps,
1989 snap->ds->ds_dir->dd_origin_txg, &space);
1990 if (err != 0)
1991 goto out;
1992 ddpa->cloneusedsnap += space;
1993 }
1994 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
1995 err = snaplist_space(&ddpa->origin_snaps,
1996 origin_ds->ds_phys->ds_creation_txg, &ddpa->originusedsnap);
1997 if (err != 0)
1998 goto out;
1999 }
2000
2001 out:
2002 promote_rele(ddpa, FTAG);
2003 return (err);
2004 }
2005
2006 static void
2007 dsl_dataset_promote_sync(void *arg, dmu_tx_t *tx)
2008 {
2009 dsl_dataset_promote_arg_t *ddpa = arg;
2010 dsl_pool_t *dp = dmu_tx_pool(tx);
2011 dsl_dataset_t *hds;
2012 struct promotenode *snap;
2013 dsl_dataset_t *origin_ds;
2014 dsl_dataset_t *origin_head;
2015 dsl_dir_t *dd;
2016 dsl_dir_t *odd = NULL;
2017 uint64_t oldnext_obj;
2018 int64_t delta;
2019
2020 VERIFY0(promote_hold(ddpa, dp, FTAG));
2021 hds = ddpa->ddpa_clone;
2022
2023 ASSERT0(hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE);
2024
2025 snap = list_head(&ddpa->shared_snaps);
2026 origin_ds = snap->ds;
2027 dd = hds->ds_dir;
2028
2029 snap = list_head(&ddpa->origin_snaps);
2030 origin_head = snap->ds;
2031
2032 /*
2033 * We need to explicitly open odd, since origin_ds's dd will be
2034 * changing.
2035 */
2036 VERIFY0(dsl_dir_hold_obj(dp, origin_ds->ds_dir->dd_object,
2037 NULL, FTAG, &odd));
2038
2039 /* change origin's next snap */
2040 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx);
2041 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj;
2042 snap = list_tail(&ddpa->clone_snaps);
2043 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2044 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object;
2045
2046 /* change the origin's next clone */
2047 if (origin_ds->ds_phys->ds_next_clones_obj) {
2048 dsl_dataset_remove_from_next_clones(origin_ds,
2049 snap->ds->ds_object, tx);
2050 VERIFY0(zap_add_int(dp->dp_meta_objset,
2051 origin_ds->ds_phys->ds_next_clones_obj,
2052 oldnext_obj, tx));
2053 }
2054
2055 /* change origin */
2056 dmu_buf_will_dirty(dd->dd_dbuf, tx);
2057 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object);
2058 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj;
2059 dd->dd_origin_txg = origin_head->ds_dir->dd_origin_txg;
2060 dmu_buf_will_dirty(odd->dd_dbuf, tx);
2061 odd->dd_phys->dd_origin_obj = origin_ds->ds_object;
2062 origin_head->ds_dir->dd_origin_txg =
2063 origin_ds->ds_phys->ds_creation_txg;
2064
2065 /* change dd_clone entries */
2066 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2067 VERIFY0(zap_remove_int(dp->dp_meta_objset,
2068 odd->dd_phys->dd_clones, hds->ds_object, tx));
2069 VERIFY0(zap_add_int(dp->dp_meta_objset,
2070 ddpa->origin_origin->ds_dir->dd_phys->dd_clones,
2071 hds->ds_object, tx));
2072
2073 VERIFY0(zap_remove_int(dp->dp_meta_objset,
2074 ddpa->origin_origin->ds_dir->dd_phys->dd_clones,
2075 origin_head->ds_object, tx));
2076 if (dd->dd_phys->dd_clones == 0) {
2077 dd->dd_phys->dd_clones = zap_create(dp->dp_meta_objset,
2078 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
2079 }
2080 VERIFY0(zap_add_int(dp->dp_meta_objset,
2081 dd->dd_phys->dd_clones, origin_head->ds_object, tx));
2082 }
2083
2084 /* move snapshots to this dir */
2085 for (snap = list_head(&ddpa->shared_snaps); snap;
2086 snap = list_next(&ddpa->shared_snaps, snap)) {
2087 dsl_dataset_t *ds = snap->ds;
2088
2089 /*
2090 * Property callbacks are registered to a particular
2091 * dsl_dir. Since ours is changing, evict the objset
2092 * so that they will be unregistered from the old dsl_dir.
2093 */
2094 if (ds->ds_objset) {
2095 dmu_objset_evict(ds->ds_objset);
2096 ds->ds_objset = NULL;
2097 }
2098
2099 /* move snap name entry */
2100 VERIFY0(dsl_dataset_get_snapname(ds));
2101 VERIFY0(dsl_dataset_snap_remove(origin_head,
2102 ds->ds_snapname, tx));
2103 VERIFY0(zap_add(dp->dp_meta_objset,
2104 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname,
2105 8, 1, &ds->ds_object, tx));
2106
2107 /* change containing dsl_dir */
2108 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2109 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object);
2110 ds->ds_phys->ds_dir_obj = dd->dd_object;
2111 ASSERT3P(ds->ds_dir, ==, odd);
2112 dsl_dir_rele(ds->ds_dir, ds);
2113 VERIFY0(dsl_dir_hold_obj(dp, dd->dd_object,
2114 NULL, ds, &ds->ds_dir));
2115
2116 /* move any clone references */
2117 if (ds->ds_phys->ds_next_clones_obj &&
2118 spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2119 zap_cursor_t zc;
2120 zap_attribute_t za;
2121
2122 for (zap_cursor_init(&zc, dp->dp_meta_objset,
2123 ds->ds_phys->ds_next_clones_obj);
2124 zap_cursor_retrieve(&zc, &za) == 0;
2125 zap_cursor_advance(&zc)) {
2126 dsl_dataset_t *cnds;
2127 uint64_t o;
2128
2129 if (za.za_first_integer == oldnext_obj) {
2130 /*
2131 * We've already moved the
2132 * origin's reference.
2133 */
2134 continue;
2135 }
2136
2137 VERIFY0(dsl_dataset_hold_obj(dp,
2138 za.za_first_integer, FTAG, &cnds));
2139 o = cnds->ds_dir->dd_phys->dd_head_dataset_obj;
2140
2141 VERIFY0(zap_remove_int(dp->dp_meta_objset,
2142 odd->dd_phys->dd_clones, o, tx));
2143 VERIFY0(zap_add_int(dp->dp_meta_objset,
2144 dd->dd_phys->dd_clones, o, tx));
2145 dsl_dataset_rele(cnds, FTAG);
2146 }
2147 zap_cursor_fini(&zc);
2148 }
2149
2150 ASSERT(!dsl_prop_hascb(ds));
2151 }
2152
2153 /*
2154 * Change space accounting.
2155 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either
2156 * both be valid, or both be 0 (resulting in delta == 0). This
2157 * is true for each of {clone,origin} independently.
2158 */
2159
2160 delta = ddpa->cloneusedsnap -
2161 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2162 ASSERT3S(delta, >=, 0);
2163 ASSERT3U(ddpa->used, >=, delta);
2164 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx);
2165 dsl_dir_diduse_space(dd, DD_USED_HEAD,
2166 ddpa->used - delta, ddpa->comp, ddpa->uncomp, tx);
2167
2168 delta = ddpa->originusedsnap -
2169 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2170 ASSERT3S(delta, <=, 0);
2171 ASSERT3U(ddpa->used, >=, -delta);
2172 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx);
2173 dsl_dir_diduse_space(odd, DD_USED_HEAD,
2174 -ddpa->used - delta, -ddpa->comp, -ddpa->uncomp, tx);
2175
2176 origin_ds->ds_phys->ds_unique_bytes = ddpa->unique;
2177
2178 /* log history record */
2179 spa_history_log_internal_ds(hds, "promote", tx, "");
2180
2181 dsl_dir_rele(odd, FTAG);
2182 promote_rele(ddpa, FTAG);
2183 }
2184
2185 /*
2186 * Make a list of dsl_dataset_t's for the snapshots between first_obj
2187 * (exclusive) and last_obj (inclusive). The list will be in reverse
2188 * order (last_obj will be the list_head()). If first_obj == 0, do all
2189 * snapshots back to this dataset's origin.
2190 */
2191 static int
2192 snaplist_make(dsl_pool_t *dp,
2193 uint64_t first_obj, uint64_t last_obj, list_t *l, void *tag)
2194 {
2195 uint64_t obj = last_obj;
2196
2197 list_create(l, sizeof (struct promotenode),
2198 offsetof(struct promotenode, link));
2199
2200 while (obj != first_obj) {
2201 dsl_dataset_t *ds;
2202 struct promotenode *snap;
2203 int err;
2204
2205 err = dsl_dataset_hold_obj(dp, obj, tag, &ds);
2206 ASSERT(err != ENOENT);
2207 if (err != 0)
2208 return (err);
2209
2210 if (first_obj == 0)
2211 first_obj = ds->ds_dir->dd_phys->dd_origin_obj;
2212
2213 snap = kmem_alloc(sizeof (*snap), KM_SLEEP);
2214 snap->ds = ds;
2215 list_insert_tail(l, snap);
2216 obj = ds->ds_phys->ds_prev_snap_obj;
2217 }
2218
2219 return (0);
2220 }
2221
2222 static int
2223 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep)
2224 {
2225 struct promotenode *snap;
2226
2227 *spacep = 0;
2228 for (snap = list_head(l); snap; snap = list_next(l, snap)) {
2229 uint64_t used, comp, uncomp;
2230 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2231 mintxg, UINT64_MAX, &used, &comp, &uncomp);
2232 *spacep += used;
2233 }
2234 return (0);
2235 }
2236
2237 static void
2238 snaplist_destroy(list_t *l, void *tag)
2239 {
2240 struct promotenode *snap;
2241
2242 if (l == NULL || !list_link_active(&l->list_head))
2243 return;
2244
2245 while ((snap = list_tail(l)) != NULL) {
2246 list_remove(l, snap);
2247 dsl_dataset_rele(snap->ds, tag);
2248 kmem_free(snap, sizeof (*snap));
2249 }
2250 list_destroy(l);
2251 }
2252
2253 static int
2254 promote_hold(dsl_dataset_promote_arg_t *ddpa, dsl_pool_t *dp, void *tag)
2255 {
2256 int error;
2257 dsl_dir_t *dd;
2258 struct promotenode *snap;
2259
2260 error = dsl_dataset_hold(dp, ddpa->ddpa_clonename, tag,
2261 &ddpa->ddpa_clone);
2262 if (error != 0)
2263 return (error);
2264 dd = ddpa->ddpa_clone->ds_dir;
2265
2266 if (dsl_dataset_is_snapshot(ddpa->ddpa_clone) ||
2267 !dsl_dir_is_clone(dd)) {
2268 dsl_dataset_rele(ddpa->ddpa_clone, tag);
2269 return (SET_ERROR(EINVAL));
2270 }
2271
2272 error = snaplist_make(dp, 0, dd->dd_phys->dd_origin_obj,
2273 &ddpa->shared_snaps, tag);
2274 if (error != 0)
2275 goto out;
2276
2277 error = snaplist_make(dp, 0, ddpa->ddpa_clone->ds_object,
2278 &ddpa->clone_snaps, tag);
2279 if (error != 0)
2280 goto out;
2281
2282 snap = list_head(&ddpa->shared_snaps);
2283 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj);
2284 error = snaplist_make(dp, dd->dd_phys->dd_origin_obj,
2285 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj,
2286 &ddpa->origin_snaps, tag);
2287 if (error != 0)
2288 goto out;
2289
2290 if (snap->ds->ds_dir->dd_phys->dd_origin_obj != 0) {
2291 error = dsl_dataset_hold_obj(dp,
2292 snap->ds->ds_dir->dd_phys->dd_origin_obj,
2293 tag, &ddpa->origin_origin);
2294 if (error != 0)
2295 goto out;
2296 }
2297 out:
2298 if (error != 0)
2299 promote_rele(ddpa, tag);
2300 return (error);
2301 }
2302
2303 static void
2304 promote_rele(dsl_dataset_promote_arg_t *ddpa, void *tag)
2305 {
2306 snaplist_destroy(&ddpa->shared_snaps, tag);
2307 snaplist_destroy(&ddpa->clone_snaps, tag);
2308 snaplist_destroy(&ddpa->origin_snaps, tag);
2309 if (ddpa->origin_origin != NULL)
2310 dsl_dataset_rele(ddpa->origin_origin, tag);
2311 dsl_dataset_rele(ddpa->ddpa_clone, tag);
2312 }
2313
2314 /*
2315 * Promote a clone.
2316 *
2317 * If it fails due to a conflicting snapshot name, "conflsnap" will be filled
2318 * in with the name. (It must be at least MAXNAMELEN bytes long.)
2319 */
2320 int
2321 dsl_dataset_promote(const char *name, char *conflsnap)
2322 {
2323 dsl_dataset_promote_arg_t ddpa = { 0 };
2324 uint64_t numsnaps;
2325 int error;
2326 objset_t *os;
2327
2328 /*
2329 * We will modify space proportional to the number of
2330 * snapshots. Compute numsnaps.
2331 */
2332 error = dmu_objset_hold(name, FTAG, &os);
2333 if (error != 0)
2334 return (error);
2335 error = zap_count(dmu_objset_pool(os)->dp_meta_objset,
2336 dmu_objset_ds(os)->ds_phys->ds_snapnames_zapobj, &numsnaps);
2337 dmu_objset_rele(os, FTAG);
2338 if (error != 0)
2339 return (error);
2340
2341 ddpa.ddpa_clonename = name;
2342 ddpa.err_ds = conflsnap;
2343
2344 return (dsl_sync_task(name, dsl_dataset_promote_check,
2345 dsl_dataset_promote_sync, &ddpa, 2 + numsnaps));
2346 }
2347
2348 int
2349 dsl_dataset_clone_swap_check_impl(dsl_dataset_t *clone,
2350 dsl_dataset_t *origin_head, boolean_t force, void *owner, dmu_tx_t *tx)
2351 {
2352 int64_t unused_refres_delta;
2353
2354 /* they should both be heads */
2355 if (dsl_dataset_is_snapshot(clone) ||
2356 dsl_dataset_is_snapshot(origin_head))
2357 return (SET_ERROR(EINVAL));
2358
2359 /* if we are not forcing, the branch point should be just before them */
2360 if (!force && clone->ds_prev != origin_head->ds_prev)
2361 return (SET_ERROR(EINVAL));
2362
2363 /* clone should be the clone (unless they are unrelated) */
2364 if (clone->ds_prev != NULL &&
2365 clone->ds_prev != clone->ds_dir->dd_pool->dp_origin_snap &&
2366 origin_head->ds_dir != clone->ds_prev->ds_dir)
2367 return (SET_ERROR(EINVAL));
2368
2369 /* the clone should be a child of the origin */
2370 if (clone->ds_dir->dd_parent != origin_head->ds_dir)
2371 return (SET_ERROR(EINVAL));
2372
2373 /* origin_head shouldn't be modified unless 'force' */
2374 if (!force &&
2375 dsl_dataset_modified_since_snap(origin_head, origin_head->ds_prev))
2376 return (SET_ERROR(ETXTBSY));
2377
2378 /* origin_head should have no long holds (e.g. is not mounted) */
2379 if (dsl_dataset_handoff_check(origin_head, owner, tx))
2380 return (SET_ERROR(EBUSY));
2381
2382 /* check amount of any unconsumed refreservation */
2383 unused_refres_delta =
2384 (int64_t)MIN(origin_head->ds_reserved,
2385 origin_head->ds_phys->ds_unique_bytes) -
2386 (int64_t)MIN(origin_head->ds_reserved,
2387 clone->ds_phys->ds_unique_bytes);
2388
2389 if (unused_refres_delta > 0 &&
2390 unused_refres_delta >
2391 dsl_dir_space_available(origin_head->ds_dir, NULL, 0, TRUE))
2392 return (SET_ERROR(ENOSPC));
2393
2394 /* clone can't be over the head's refquota */
2395 if (origin_head->ds_quota != 0 &&
2396 clone->ds_phys->ds_referenced_bytes > origin_head->ds_quota)
2397 return (SET_ERROR(EDQUOT));
2398
2399 return (0);
2400 }
2401
2402 void
2403 dsl_dataset_clone_swap_sync_impl(dsl_dataset_t *clone,
2404 dsl_dataset_t *origin_head, dmu_tx_t *tx)
2405 {
2406 dsl_pool_t *dp = dmu_tx_pool(tx);
2407 int64_t unused_refres_delta;
2408
2409 ASSERT(clone->ds_reserved == 0);
2410 ASSERT(origin_head->ds_quota == 0 ||
2411 clone->ds_phys->ds_unique_bytes <= origin_head->ds_quota);
2412 ASSERT3P(clone->ds_prev, ==, origin_head->ds_prev);
2413
2414 dmu_buf_will_dirty(clone->ds_dbuf, tx);
2415 dmu_buf_will_dirty(origin_head->ds_dbuf, tx);
2416
2417 if (clone->ds_objset != NULL) {
2418 dmu_objset_evict(clone->ds_objset);
2419 clone->ds_objset = NULL;
2420 }
2421
2422 if (origin_head->ds_objset != NULL) {
2423 dmu_objset_evict(origin_head->ds_objset);
2424 origin_head->ds_objset = NULL;
2425 }
2426
2427 unused_refres_delta =
2428 (int64_t)MIN(origin_head->ds_reserved,
2429 origin_head->ds_phys->ds_unique_bytes) -
2430 (int64_t)MIN(origin_head->ds_reserved,
2431 clone->ds_phys->ds_unique_bytes);
2432
2433 /*
2434 * Reset origin's unique bytes, if it exists.
2435 */
2436 if (clone->ds_prev) {
2437 dsl_dataset_t *origin = clone->ds_prev;
2438 uint64_t comp, uncomp;
2439
2440 dmu_buf_will_dirty(origin->ds_dbuf, tx);
2441 dsl_deadlist_space_range(&clone->ds_deadlist,
2442 origin->ds_phys->ds_prev_snap_txg, UINT64_MAX,
2443 &origin->ds_phys->ds_unique_bytes, &comp, &uncomp);
2444 }
2445
2446 /* swap blkptrs */
2447 {
2448 blkptr_t tmp;
2449 tmp = origin_head->ds_phys->ds_bp;
2450 origin_head->ds_phys->ds_bp = clone->ds_phys->ds_bp;
2451 clone->ds_phys->ds_bp = tmp;
2452 }
2453
2454 /* set dd_*_bytes */
2455 {
2456 int64_t dused, dcomp, duncomp;
2457 uint64_t cdl_used, cdl_comp, cdl_uncomp;
2458 uint64_t odl_used, odl_comp, odl_uncomp;
2459
2460 ASSERT3U(clone->ds_dir->dd_phys->
2461 dd_used_breakdown[DD_USED_SNAP], ==, 0);
2462
2463 dsl_deadlist_space(&clone->ds_deadlist,
2464 &cdl_used, &cdl_comp, &cdl_uncomp);
2465 dsl_deadlist_space(&origin_head->ds_deadlist,
2466 &odl_used, &odl_comp, &odl_uncomp);
2467
2468 dused = clone->ds_phys->ds_referenced_bytes + cdl_used -
2469 (origin_head->ds_phys->ds_referenced_bytes + odl_used);
2470 dcomp = clone->ds_phys->ds_compressed_bytes + cdl_comp -
2471 (origin_head->ds_phys->ds_compressed_bytes + odl_comp);
2472 duncomp = clone->ds_phys->ds_uncompressed_bytes +
2473 cdl_uncomp -
2474 (origin_head->ds_phys->ds_uncompressed_bytes + odl_uncomp);
2475
2476 dsl_dir_diduse_space(origin_head->ds_dir, DD_USED_HEAD,
2477 dused, dcomp, duncomp, tx);
2478 dsl_dir_diduse_space(clone->ds_dir, DD_USED_HEAD,
2479 -dused, -dcomp, -duncomp, tx);
2480
2481 /*
2482 * The difference in the space used by snapshots is the
2483 * difference in snapshot space due to the head's
2484 * deadlist (since that's the only thing that's
2485 * changing that affects the snapused).
2486 */
2487 dsl_deadlist_space_range(&clone->ds_deadlist,
2488 origin_head->ds_dir->dd_origin_txg, UINT64_MAX,
2489 &cdl_used, &cdl_comp, &cdl_uncomp);
2490 dsl_deadlist_space_range(&origin_head->ds_deadlist,
2491 origin_head->ds_dir->dd_origin_txg, UINT64_MAX,
2492 &odl_used, &odl_comp, &odl_uncomp);
2493 dsl_dir_transfer_space(origin_head->ds_dir, cdl_used - odl_used,
2494 DD_USED_HEAD, DD_USED_SNAP, tx);
2495 }
2496
2497 /* swap ds_*_bytes */
2498 SWITCH64(origin_head->ds_phys->ds_referenced_bytes,
2499 clone->ds_phys->ds_referenced_bytes);
2500 SWITCH64(origin_head->ds_phys->ds_compressed_bytes,
2501 clone->ds_phys->ds_compressed_bytes);
2502 SWITCH64(origin_head->ds_phys->ds_uncompressed_bytes,
2503 clone->ds_phys->ds_uncompressed_bytes);
2504 SWITCH64(origin_head->ds_phys->ds_unique_bytes,
2505 clone->ds_phys->ds_unique_bytes);
2506
2507 /* apply any parent delta for change in unconsumed refreservation */
2508 dsl_dir_diduse_space(origin_head->ds_dir, DD_USED_REFRSRV,
2509 unused_refres_delta, 0, 0, tx);
2510
2511 /*
2512 * Swap deadlists.
2513 */
2514 dsl_deadlist_close(&clone->ds_deadlist);
2515 dsl_deadlist_close(&origin_head->ds_deadlist);
2516 SWITCH64(origin_head->ds_phys->ds_deadlist_obj,
2517 clone->ds_phys->ds_deadlist_obj);
2518 dsl_deadlist_open(&clone->ds_deadlist, dp->dp_meta_objset,
2519 clone->ds_phys->ds_deadlist_obj);
2520 dsl_deadlist_open(&origin_head->ds_deadlist, dp->dp_meta_objset,
2521 origin_head->ds_phys->ds_deadlist_obj);
2522
2523 dsl_scan_ds_clone_swapped(origin_head, clone, tx);
2524
2525 spa_history_log_internal_ds(clone, "clone swap", tx,
2526 "parent=%s", origin_head->ds_dir->dd_myname);
2527 }
2528
2529 /*
2530 * Given a pool name and a dataset object number in that pool,
2531 * return the name of that dataset.
2532 */
2533 int
2534 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf)
2535 {
2536 dsl_pool_t *dp;
2537 dsl_dataset_t *ds;
2538 int error;
2539
2540 error = dsl_pool_hold(pname, FTAG, &dp);
2541 if (error != 0)
2542 return (error);
2543
2544 error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds);
2545 if (error == 0) {
2546 dsl_dataset_name(ds, buf);
2547 dsl_dataset_rele(ds, FTAG);
2548 }
2549 dsl_pool_rele(dp, FTAG);
2550
2551 return (error);
2552 }
2553
2554 int
2555 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota,
2556 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv)
2557 {
2558 int error = 0;
2559
2560 ASSERT3S(asize, >, 0);
2561
2562 /*
2563 * *ref_rsrv is the portion of asize that will come from any
2564 * unconsumed refreservation space.
2565 */
2566 *ref_rsrv = 0;
2567
2568 mutex_enter(&ds->ds_lock);
2569 /*
2570 * Make a space adjustment for reserved bytes.
2571 */
2572 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) {
2573 ASSERT3U(*used, >=,
2574 ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
2575 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
2576 *ref_rsrv =
2577 asize - MIN(asize, parent_delta(ds, asize + inflight));
2578 }
2579
2580 if (!check_quota || ds->ds_quota == 0) {
2581 mutex_exit(&ds->ds_lock);
2582 return (0);
2583 }
2584 /*
2585 * If they are requesting more space, and our current estimate
2586 * is over quota, they get to try again unless the actual
2587 * on-disk is over quota and there are no pending changes (which
2588 * may free up space for us).
2589 */
2590 if (ds->ds_phys->ds_referenced_bytes + inflight >= ds->ds_quota) {
2591 if (inflight > 0 ||
2592 ds->ds_phys->ds_referenced_bytes < ds->ds_quota)
2593 error = SET_ERROR(ERESTART);
2594 else
2595 error = SET_ERROR(EDQUOT);
2596 }
2597 mutex_exit(&ds->ds_lock);
2598
2599 return (error);
2600 }
2601
2602 typedef struct dsl_dataset_set_qr_arg {
2603 const char *ddsqra_name;
2604 zprop_source_t ddsqra_source;
2605 uint64_t ddsqra_value;
2606 } dsl_dataset_set_qr_arg_t;
2607
2608
2609 /* ARGSUSED */
2610 static int
2611 dsl_dataset_set_refquota_check(void *arg, dmu_tx_t *tx)
2612 {
2613 dsl_dataset_set_qr_arg_t *ddsqra = arg;
2614 dsl_pool_t *dp = dmu_tx_pool(tx);
2615 dsl_dataset_t *ds;
2616 int error;
2617 uint64_t newval;
2618
2619 if (spa_version(dp->dp_spa) < SPA_VERSION_REFQUOTA)
2620 return (SET_ERROR(ENOTSUP));
2621
2622 error = dsl_dataset_hold(dp, ddsqra->ddsqra_name, FTAG, &ds);
2623 if (error != 0)
2624 return (error);
2625
2626 if (dsl_dataset_is_snapshot(ds)) {
2627 dsl_dataset_rele(ds, FTAG);
2628 return (SET_ERROR(EINVAL));
2629 }
2630
2631 error = dsl_prop_predict(ds->ds_dir,
2632 zfs_prop_to_name(ZFS_PROP_REFQUOTA),
2633 ddsqra->ddsqra_source, ddsqra->ddsqra_value, &newval);
2634 if (error != 0) {
2635 dsl_dataset_rele(ds, FTAG);
2636 return (error);
2637 }
2638
2639 if (newval == 0) {
2640 dsl_dataset_rele(ds, FTAG);
2641 return (0);
2642 }
2643
2644 if (newval < ds->ds_phys->ds_referenced_bytes ||
2645 newval < ds->ds_reserved) {
2646 dsl_dataset_rele(ds, FTAG);
2647 return (SET_ERROR(ENOSPC));
2648 }
2649
2650 dsl_dataset_rele(ds, FTAG);
2651 return (0);
2652 }
2653
2654 static void
2655 dsl_dataset_set_refquota_sync(void *arg, dmu_tx_t *tx)
2656 {
2657 dsl_dataset_set_qr_arg_t *ddsqra = arg;
2658 dsl_pool_t *dp = dmu_tx_pool(tx);
2659 dsl_dataset_t *ds;
2660 uint64_t newval;
2661
2662 VERIFY0(dsl_dataset_hold(dp, ddsqra->ddsqra_name, FTAG, &ds));
2663
2664 dsl_prop_set_sync_impl(ds,
2665 zfs_prop_to_name(ZFS_PROP_REFQUOTA),
2666 ddsqra->ddsqra_source, sizeof (ddsqra->ddsqra_value), 1,
2667 &ddsqra->ddsqra_value, tx);
2668
2669 VERIFY0(dsl_prop_get_int_ds(ds,
2670 zfs_prop_to_name(ZFS_PROP_REFQUOTA), &newval));
2671
2672 if (ds->ds_quota != newval) {
2673 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2674 ds->ds_quota = newval;
2675 }
2676 dsl_dataset_rele(ds, FTAG);
2677 }
2678
2679 int
2680 dsl_dataset_set_refquota(const char *dsname, zprop_source_t source,
2681 uint64_t refquota)
2682 {
2683 dsl_dataset_set_qr_arg_t ddsqra;
2684
2685 ddsqra.ddsqra_name = dsname;
2686 ddsqra.ddsqra_source = source;
2687 ddsqra.ddsqra_value = refquota;
2688
2689 return (dsl_sync_task(dsname, dsl_dataset_set_refquota_check,
2690 dsl_dataset_set_refquota_sync, &ddsqra, 0));
2691 }
2692
2693 static int
2694 dsl_dataset_set_refreservation_check(void *arg, dmu_tx_t *tx)
2695 {
2696 dsl_dataset_set_qr_arg_t *ddsqra = arg;
2697 dsl_pool_t *dp = dmu_tx_pool(tx);
2698 dsl_dataset_t *ds;
2699 int error;
2700 uint64_t newval, unique;
2701
2702 if (spa_version(dp->dp_spa) < SPA_VERSION_REFRESERVATION)
2703 return (SET_ERROR(ENOTSUP));
2704
2705 error = dsl_dataset_hold(dp, ddsqra->ddsqra_name, FTAG, &ds);
2706 if (error != 0)
2707 return (error);
2708
2709 if (dsl_dataset_is_snapshot(ds)) {
2710 dsl_dataset_rele(ds, FTAG);
2711 return (SET_ERROR(EINVAL));
2712 }
2713
2714 error = dsl_prop_predict(ds->ds_dir,
2715 zfs_prop_to_name(ZFS_PROP_REFRESERVATION),
2716 ddsqra->ddsqra_source, ddsqra->ddsqra_value, &newval);
2717 if (error != 0) {
2718 dsl_dataset_rele(ds, FTAG);
2719 return (error);
2720 }
2721
2722 /*
2723 * If we are doing the preliminary check in open context, the
2724 * space estimates may be inaccurate.
2725 */
2726 if (!dmu_tx_is_syncing(tx)) {
2727 dsl_dataset_rele(ds, FTAG);
2728 return (0);
2729 }
2730
2731 mutex_enter(&ds->ds_lock);
2732 if (!DS_UNIQUE_IS_ACCURATE(ds))
2733 dsl_dataset_recalc_head_uniq(ds);
2734 unique = ds->ds_phys->ds_unique_bytes;
2735 mutex_exit(&ds->ds_lock);
2736
2737 if (MAX(unique, newval) > MAX(unique, ds->ds_reserved)) {
2738 uint64_t delta = MAX(unique, newval) -
2739 MAX(unique, ds->ds_reserved);
2740
2741 if (delta >
2742 dsl_dir_space_available(ds->ds_dir, NULL, 0, B_TRUE) ||
2743 (ds->ds_quota > 0 && newval > ds->ds_quota)) {
2744 dsl_dataset_rele(ds, FTAG);
2745 return (SET_ERROR(ENOSPC));
2746 }
2747 }
2748
2749 dsl_dataset_rele(ds, FTAG);
2750 return (0);
2751 }
2752
2753 void
2754 dsl_dataset_set_refreservation_sync_impl(dsl_dataset_t *ds,
2755 zprop_source_t source, uint64_t value, dmu_tx_t *tx)
2756 {
2757 uint64_t newval;
2758 uint64_t unique;
2759 int64_t delta;
2760
2761 dsl_prop_set_sync_impl(ds, zfs_prop_to_name(ZFS_PROP_REFRESERVATION),
2762 source, sizeof (value), 1, &value, tx);
2763
2764 VERIFY0(dsl_prop_get_int_ds(ds,
2765 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), &newval));
2766
2767 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2768 mutex_enter(&ds->ds_dir->dd_lock);
2769 mutex_enter(&ds->ds_lock);
2770 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
2771 unique = ds->ds_phys->ds_unique_bytes;
2772 delta = MAX(0, (int64_t)(newval - unique)) -
2773 MAX(0, (int64_t)(ds->ds_reserved - unique));
2774 ds->ds_reserved = newval;
2775 mutex_exit(&ds->ds_lock);
2776
2777 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx);
2778 mutex_exit(&ds->ds_dir->dd_lock);
2779 }
2780
2781 static void
2782 dsl_dataset_set_refreservation_sync(void *arg, dmu_tx_t *tx)
2783 {
2784 dsl_dataset_set_qr_arg_t *ddsqra = arg;
2785 dsl_pool_t *dp = dmu_tx_pool(tx);
2786 dsl_dataset_t *ds;
2787
2788 VERIFY0(dsl_dataset_hold(dp, ddsqra->ddsqra_name, FTAG, &ds));
2789 dsl_dataset_set_refreservation_sync_impl(ds,
2790 ddsqra->ddsqra_source, ddsqra->ddsqra_value, tx);
2791 dsl_dataset_rele(ds, FTAG);
2792 }
2793
2794 int
2795 dsl_dataset_set_refreservation(const char *dsname, zprop_source_t source,
2796 uint64_t refreservation)
2797 {
2798 dsl_dataset_set_qr_arg_t ddsqra;
2799
2800 ddsqra.ddsqra_name = dsname;
2801 ddsqra.ddsqra_source = source;
2802 ddsqra.ddsqra_value = refreservation;
2803
2804 return (dsl_sync_task(dsname, dsl_dataset_set_refreservation_check,
2805 dsl_dataset_set_refreservation_sync, &ddsqra, 0));
2806 }
2807
2808 /*
2809 * Return (in *usedp) the amount of space written in new that is not
2810 * present in oldsnap. New may be a snapshot or the head. Old must be
2811 * a snapshot before new, in new's filesystem (or its origin). If not then
2812 * fail and return EINVAL.
2813 *
2814 * The written space is calculated by considering two components: First, we
2815 * ignore any freed space, and calculate the written as new's used space
2816 * minus old's used space. Next, we add in the amount of space that was freed
2817 * between the two snapshots, thus reducing new's used space relative to old's.
2818 * Specifically, this is the space that was born before old->ds_creation_txg,
2819 * and freed before new (ie. on new's deadlist or a previous deadlist).
2820 *
2821 * space freed [---------------------]
2822 * snapshots ---O-------O--------O-------O------
2823 * oldsnap new
2824 */
2825 int
2826 dsl_dataset_space_written(dsl_dataset_t *oldsnap, dsl_dataset_t *new,
2827 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
2828 {
2829 int err = 0;
2830 uint64_t snapobj;
2831 dsl_pool_t *dp = new->ds_dir->dd_pool;
2832
2833 ASSERT(dsl_pool_config_held(dp));
2834
2835 *usedp = 0;
2836 *usedp += new->ds_phys->ds_referenced_bytes;
2837 *usedp -= oldsnap->ds_phys->ds_referenced_bytes;
2838
2839 *compp = 0;
2840 *compp += new->ds_phys->ds_compressed_bytes;
2841 *compp -= oldsnap->ds_phys->ds_compressed_bytes;
2842
2843 *uncompp = 0;
2844 *uncompp += new->ds_phys->ds_uncompressed_bytes;
2845 *uncompp -= oldsnap->ds_phys->ds_uncompressed_bytes;
2846
2847 snapobj = new->ds_object;
2848 while (snapobj != oldsnap->ds_object) {
2849 dsl_dataset_t *snap;
2850 uint64_t used, comp, uncomp;
2851
2852 if (snapobj == new->ds_object) {
2853 snap = new;
2854 } else {
2855 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &snap);
2856 if (err != 0)
2857 break;
2858 }
2859
2860 if (snap->ds_phys->ds_prev_snap_txg ==
2861 oldsnap->ds_phys->ds_creation_txg) {
2862 /*
2863 * The blocks in the deadlist can not be born after
2864 * ds_prev_snap_txg, so get the whole deadlist space,
2865 * which is more efficient (especially for old-format
2866 * deadlists). Unfortunately the deadlist code
2867 * doesn't have enough information to make this
2868 * optimization itself.
2869 */
2870 dsl_deadlist_space(&snap->ds_deadlist,
2871 &used, &comp, &uncomp);
2872 } else {
2873 dsl_deadlist_space_range(&snap->ds_deadlist,
2874 0, oldsnap->ds_phys->ds_creation_txg,
2875 &used, &comp, &uncomp);
2876 }
2877 *usedp += used;
2878 *compp += comp;
2879 *uncompp += uncomp;
2880
2881 /*
2882 * If we get to the beginning of the chain of snapshots
2883 * (ds_prev_snap_obj == 0) before oldsnap, then oldsnap
2884 * was not a snapshot of/before new.
2885 */
2886 snapobj = snap->ds_phys->ds_prev_snap_obj;
2887 if (snap != new)
2888 dsl_dataset_rele(snap, FTAG);
2889 if (snapobj == 0) {
2890 err = SET_ERROR(EINVAL);
2891 break;
2892 }
2893
2894 }
2895 return (err);
2896 }
2897
2898 /*
2899 * Return (in *usedp) the amount of space that will be reclaimed if firstsnap,
2900 * lastsnap, and all snapshots in between are deleted.
2901 *
2902 * blocks that would be freed [---------------------------]
2903 * snapshots ---O-------O--------O-------O--------O
2904 * firstsnap lastsnap
2905 *
2906 * This is the set of blocks that were born after the snap before firstsnap,
2907 * (birth > firstsnap->prev_snap_txg) and died before the snap after the
2908 * last snap (ie, is on lastsnap->ds_next->ds_deadlist or an earlier deadlist).
2909 * We calculate this by iterating over the relevant deadlists (from the snap
2910 * after lastsnap, backward to the snap after firstsnap), summing up the
2911 * space on the deadlist that was born after the snap before firstsnap.
2912 */
2913 int
2914 dsl_dataset_space_wouldfree(dsl_dataset_t *firstsnap,
2915 dsl_dataset_t *lastsnap,
2916 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
2917 {
2918 int err = 0;
2919 uint64_t snapobj;
2920 dsl_pool_t *dp = firstsnap->ds_dir->dd_pool;
2921
2922 ASSERT(dsl_dataset_is_snapshot(firstsnap));
2923 ASSERT(dsl_dataset_is_snapshot(lastsnap));
2924
2925 /*
2926 * Check that the snapshots are in the same dsl_dir, and firstsnap
2927 * is before lastsnap.
2928 */
2929 if (firstsnap->ds_dir != lastsnap->ds_dir ||
2930 firstsnap->ds_phys->ds_creation_txg >
2931 lastsnap->ds_phys->ds_creation_txg)
2932 return (SET_ERROR(EINVAL));
2933
2934 *usedp = *compp = *uncompp = 0;
2935
2936 snapobj = lastsnap->ds_phys->ds_next_snap_obj;
2937 while (snapobj != firstsnap->ds_object) {
2938 dsl_dataset_t *ds;
2939 uint64_t used, comp, uncomp;
2940
2941 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &ds);
2942 if (err != 0)
2943 break;
2944
2945 dsl_deadlist_space_range(&ds->ds_deadlist,
2946 firstsnap->ds_phys->ds_prev_snap_txg, UINT64_MAX,
2947 &used, &comp, &uncomp);
2948 *usedp += used;
2949 *compp += comp;
2950 *uncompp += uncomp;
2951
2952 snapobj = ds->ds_phys->ds_prev_snap_obj;
2953 ASSERT3U(snapobj, !=, 0);
2954 dsl_dataset_rele(ds, FTAG);
2955 }
2956 return (err);
2957 }
2958
2959 /*
2960 * Return TRUE if 'earlier' is an earlier snapshot in 'later's timeline.
2961 * For example, they could both be snapshots of the same filesystem, and
2962 * 'earlier' is before 'later'. Or 'earlier' could be the origin of
2963 * 'later's filesystem. Or 'earlier' could be an older snapshot in the origin's
2964 * filesystem. Or 'earlier' could be the origin's origin.
2965 */
2966 boolean_t
2967 dsl_dataset_is_before(dsl_dataset_t *later, dsl_dataset_t *earlier)
2968 {
2969 dsl_pool_t *dp = later->ds_dir->dd_pool;
2970 int error;
2971 boolean_t ret;
2972
2973 ASSERT(dsl_pool_config_held(dp));
2974
2975 if (earlier->ds_phys->ds_creation_txg >=
2976 later->ds_phys->ds_creation_txg)
2977 return (B_FALSE);
2978
2979 if (later->ds_dir == earlier->ds_dir)
2980 return (B_TRUE);
2981 if (!dsl_dir_is_clone(later->ds_dir))
2982 return (B_FALSE);
2983
2984 if (later->ds_dir->dd_phys->dd_origin_obj == earlier->ds_object)
2985 return (B_TRUE);
2986 dsl_dataset_t *origin;
2987 error = dsl_dataset_hold_obj(dp,
2988 later->ds_dir->dd_phys->dd_origin_obj, FTAG, &origin);
2989 if (error != 0)
2990 return (B_FALSE);
2991 ret = dsl_dataset_is_before(origin, earlier);
2992 dsl_dataset_rele(origin, FTAG);
2993 return (ret);
2994 }