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1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (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, compressed, uncompressed;
86 int64_t delta;
87
88 used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
89 compressed = BP_GET_PSIZE(bp);
90 uncompressed = BP_GET_UCSIZE(bp);
91
92 dprintf_bp(bp, "ds=%p", ds);
93
94 ASSERT(dmu_tx_is_syncing(tx));
95 /* It could have been compressed away to nothing */
96 if (BP_IS_HOLE(bp))
97 return;
98 ASSERT(BP_GET_TYPE(bp) != DMU_OT_NONE);
99 ASSERT(DMU_OT_IS_VALID(BP_GET_TYPE(bp)));
100 if (ds == NULL) {
101 dsl_pool_mos_diduse_space(tx->tx_pool,
102 used, compressed, uncompressed);
103 return;
104 }
105
106 dmu_buf_will_dirty(ds->ds_dbuf, tx);
107 mutex_enter(&ds->ds_lock);
108 delta = parent_delta(ds, used);
109 ds->ds_phys->ds_referenced_bytes += used;
110 ds->ds_phys->ds_compressed_bytes += compressed;
111 ds->ds_phys->ds_uncompressed_bytes += uncompressed;
112 ds->ds_phys->ds_unique_bytes += used;
113 mutex_exit(&ds->ds_lock);
114 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta,
115 compressed, uncompressed, tx);
116 dsl_dir_transfer_space(ds->ds_dir, used - delta,
117 DD_USED_REFRSRV, DD_USED_HEAD, tx);
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 int used, compressed, uncompressed;
125
126 if (BP_IS_HOLE(bp))
127 return (0);
128
129 ASSERT(dmu_tx_is_syncing(tx));
130 ASSERT(bp->blk_birth <= tx->tx_txg);
131
132 used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
133 compressed = BP_GET_PSIZE(bp);
134 uncompressed = BP_GET_UCSIZE(bp);
135
136 ASSERT(used > 0);
137 if (ds == NULL) {
138 dsl_free(tx->tx_pool, tx->tx_txg, bp);
139 dsl_pool_mos_diduse_space(tx->tx_pool,
140 -used, -compressed, -uncompressed);
141 return (used);
142 }
143 ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool);
144
145 ASSERT(!dsl_dataset_is_snapshot(ds));
146 dmu_buf_will_dirty(ds->ds_dbuf, tx);
147
148 if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) {
149 int64_t delta;
150
151 dprintf_bp(bp, "freeing ds=%llu", ds->ds_object);
152 dsl_free(tx->tx_pool, tx->tx_txg, bp);
153
154 mutex_enter(&ds->ds_lock);
155 ASSERT(ds->ds_phys->ds_unique_bytes >= used ||
156 !DS_UNIQUE_IS_ACCURATE(ds));
157 delta = parent_delta(ds, -used);
158 ds->ds_phys->ds_unique_bytes -= used;
159 mutex_exit(&ds->ds_lock);
160 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
161 delta, -compressed, -uncompressed, tx);
162 dsl_dir_transfer_space(ds->ds_dir, -used - delta,
163 DD_USED_REFRSRV, DD_USED_HEAD, tx);
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_PUSHPAGE);
369 ds->ds_dbuf = dbuf;
370 ds->ds_object = dsobj;
371 ds->ds_phys = dbuf->db_data;
372 list_link_init(&ds->ds_synced_link);
373
374 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL);
375 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL);
376 mutex_init(&ds->ds_sendstream_lock, NULL, MUTEX_DEFAULT, NULL);
377 refcount_create(&ds->ds_longholds);
378
379 bplist_create(&ds->ds_pending_deadlist);
380 dsl_deadlist_open(&ds->ds_deadlist,
381 mos, ds->ds_phys->ds_deadlist_obj);
382
383 list_create(&ds->ds_sendstreams, sizeof (dmu_sendarg_t),
384 offsetof(dmu_sendarg_t, dsa_link));
385
386 if (err == 0) {
387 err = dsl_dir_hold_obj(dp,
388 ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir);
389 }
390 if (err != 0) {
391 mutex_destroy(&ds->ds_lock);
392 mutex_destroy(&ds->ds_opening_lock);
393 refcount_destroy(&ds->ds_longholds);
394 bplist_destroy(&ds->ds_pending_deadlist);
395 dsl_deadlist_close(&ds->ds_deadlist);
396 kmem_free(ds, sizeof (dsl_dataset_t));
397 dmu_buf_rele(dbuf, tag);
398 return (err);
399 }
400
401 if (!dsl_dataset_is_snapshot(ds)) {
402 ds->ds_snapname[0] = '\0';
403 if (ds->ds_phys->ds_prev_snap_obj != 0) {
404 err = dsl_dataset_hold_obj(dp,
405 ds->ds_phys->ds_prev_snap_obj,
406 ds, &ds->ds_prev);
407 }
408 } else {
409 if (zfs_flags & ZFS_DEBUG_SNAPNAMES)
410 err = dsl_dataset_get_snapname(ds);
411 if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) {
412 err = zap_count(
413 ds->ds_dir->dd_pool->dp_meta_objset,
414 ds->ds_phys->ds_userrefs_obj,
415 &ds->ds_userrefs);
416 }
417 }
418
419 if (err == 0 && !dsl_dataset_is_snapshot(ds)) {
420 err = dsl_prop_get_int_ds(ds,
421 zfs_prop_to_name(ZFS_PROP_REFRESERVATION),
422 &ds->ds_reserved);
423 if (err == 0) {
424 err = dsl_prop_get_int_ds(ds,
425 zfs_prop_to_name(ZFS_PROP_REFQUOTA),
426 &ds->ds_quota);
427 }
428 } else {
429 ds->ds_reserved = ds->ds_quota = 0;
430 }
431
432 if (err != 0 || (winner = dmu_buf_set_user_ie(dbuf, ds,
433 &ds->ds_phys, dsl_dataset_evict)) != NULL) {
434 bplist_destroy(&ds->ds_pending_deadlist);
435 dsl_deadlist_close(&ds->ds_deadlist);
436 if (ds->ds_prev)
437 dsl_dataset_rele(ds->ds_prev, ds);
438 dsl_dir_rele(ds->ds_dir, ds);
439 mutex_destroy(&ds->ds_lock);
440 mutex_destroy(&ds->ds_opening_lock);
441 refcount_destroy(&ds->ds_longholds);
442 kmem_free(ds, sizeof (dsl_dataset_t));
443 if (err != 0) {
444 dmu_buf_rele(dbuf, tag);
445 return (err);
446 }
447 ds = winner;
448 } else {
449 ds->ds_fsid_guid =
450 unique_insert(ds->ds_phys->ds_fsid_guid);
451 }
452 }
453 ASSERT3P(ds->ds_dbuf, ==, dbuf);
454 ASSERT3P(ds->ds_phys, ==, dbuf->db_data);
455 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 ||
456 spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN ||
457 dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap);
458 *dsp = ds;
459 return (0);
460 }
461
462 int
463 dsl_dataset_hold(dsl_pool_t *dp, const char *name,
464 void *tag, dsl_dataset_t **dsp)
465 {
466 dsl_dir_t *dd;
467 const char *snapname;
468 uint64_t obj;
469 int err = 0;
470
471 err = dsl_dir_hold(dp, name, FTAG, &dd, &snapname);
472 if (err != 0)
473 return (err);
474
475 ASSERT(dsl_pool_config_held(dp));
476 obj = dd->dd_phys->dd_head_dataset_obj;
477 if (obj != 0)
478 err = dsl_dataset_hold_obj(dp, obj, tag, dsp);
479 else
480 err = SET_ERROR(ENOENT);
481
482 /* we may be looking for a snapshot */
483 if (err == 0 && snapname != NULL) {
484 dsl_dataset_t *ds;
485
486 if (*snapname++ != '@') {
487 dsl_dataset_rele(*dsp, tag);
488 dsl_dir_rele(dd, FTAG);
489 return (SET_ERROR(ENOENT));
490 }
491
492 dprintf("looking for snapshot '%s'\n", snapname);
493 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj);
494 if (err == 0)
495 err = dsl_dataset_hold_obj(dp, obj, tag, &ds);
496 dsl_dataset_rele(*dsp, tag);
497
498 if (err == 0) {
499 mutex_enter(&ds->ds_lock);
500 if (ds->ds_snapname[0] == 0)
501 (void) strlcpy(ds->ds_snapname, snapname,
502 sizeof (ds->ds_snapname));
503 mutex_exit(&ds->ds_lock);
504 *dsp = ds;
505 }
506 }
507
508 dsl_dir_rele(dd, FTAG);
509 return (err);
510 }
511
512 int
513 dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj,
514 void *tag, dsl_dataset_t **dsp)
515 {
516 int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp);
517 if (err != 0)
518 return (err);
519 if (!dsl_dataset_tryown(*dsp, tag)) {
520 dsl_dataset_rele(*dsp, tag);
521 *dsp = NULL;
522 return (SET_ERROR(EBUSY));
523 }
524 return (0);
525 }
526
527 int
528 dsl_dataset_own(dsl_pool_t *dp, const char *name,
529 void *tag, dsl_dataset_t **dsp)
530 {
531 int err = dsl_dataset_hold(dp, name, tag, dsp);
532 if (err != 0)
533 return (err);
534 if (!dsl_dataset_tryown(*dsp, tag)) {
535 dsl_dataset_rele(*dsp, tag);
536 return (SET_ERROR(EBUSY));
537 }
538 return (0);
539 }
540
541 /*
542 * See the comment above dsl_pool_hold() for details. In summary, a long
543 * hold is used to prevent destruction of a dataset while the pool hold
544 * is dropped, allowing other concurrent operations (e.g. spa_sync()).
545 *
546 * The dataset and pool must be held when this function is called. After it
547 * is called, the pool hold may be released while the dataset is still held
548 * and accessed.
549 */
550 void
551 dsl_dataset_long_hold(dsl_dataset_t *ds, void *tag)
552 {
553 ASSERT(dsl_pool_config_held(ds->ds_dir->dd_pool));
554 (void) refcount_add(&ds->ds_longholds, tag);
555 }
556
557 void
558 dsl_dataset_long_rele(dsl_dataset_t *ds, void *tag)
559 {
560 (void) refcount_remove(&ds->ds_longholds, tag);
561 }
562
563 /* Return B_TRUE if there are any long holds on this dataset. */
564 boolean_t
565 dsl_dataset_long_held(dsl_dataset_t *ds)
566 {
567 return (!refcount_is_zero(&ds->ds_longholds));
568 }
569
570 void
571 dsl_dataset_name(dsl_dataset_t *ds, char *name)
572 {
573 if (ds == NULL) {
574 (void) strcpy(name, "mos");
575 } else {
576 dsl_dir_name(ds->ds_dir, name);
577 VERIFY0(dsl_dataset_get_snapname(ds));
578 if (ds->ds_snapname[0]) {
579 (void) strcat(name, "@");
580 /*
581 * We use a "recursive" mutex so that we
582 * can call dprintf_ds() with ds_lock held.
583 */
584 if (!MUTEX_HELD(&ds->ds_lock)) {
585 mutex_enter(&ds->ds_lock);
586 (void) strcat(name, ds->ds_snapname);
587 mutex_exit(&ds->ds_lock);
588 } else {
589 (void) strcat(name, ds->ds_snapname);
590 }
591 }
592 }
593 }
594
595 void
596 dsl_dataset_rele(dsl_dataset_t *ds, void *tag)
597 {
598 dmu_buf_rele(ds->ds_dbuf, tag);
599 }
600
601 void
602 dsl_dataset_disown(dsl_dataset_t *ds, void *tag)
603 {
604 ASSERT(ds->ds_owner == tag && ds->ds_dbuf != NULL);
605
606 mutex_enter(&ds->ds_lock);
607 ds->ds_owner = NULL;
608 mutex_exit(&ds->ds_lock);
609 dsl_dataset_long_rele(ds, tag);
610 if (ds->ds_dbuf != NULL)
611 dsl_dataset_rele(ds, tag);
612 else
613 dsl_dataset_evict(NULL, ds);
614 }
615
616 boolean_t
617 dsl_dataset_tryown(dsl_dataset_t *ds, void *tag)
618 {
619 boolean_t gotit = FALSE;
620
621 mutex_enter(&ds->ds_lock);
622 if (ds->ds_owner == NULL && !DS_IS_INCONSISTENT(ds)) {
623 ds->ds_owner = tag;
624 dsl_dataset_long_hold(ds, tag);
625 gotit = TRUE;
626 }
627 mutex_exit(&ds->ds_lock);
628 return (gotit);
629 }
630
631 uint64_t
632 dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin,
633 uint64_t flags, dmu_tx_t *tx)
634 {
635 dsl_pool_t *dp = dd->dd_pool;
636 dmu_buf_t *dbuf;
637 dsl_dataset_phys_t *dsphys;
638 uint64_t dsobj;
639 objset_t *mos = dp->dp_meta_objset;
640
641 if (origin == NULL)
642 origin = dp->dp_origin_snap;
643
644 ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp);
645 ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0);
646 ASSERT(dmu_tx_is_syncing(tx));
647 ASSERT(dd->dd_phys->dd_head_dataset_obj == 0);
648
649 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
650 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
651 VERIFY0(dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
652 dmu_buf_will_dirty(dbuf, tx);
653 dsphys = dbuf->db_data;
654 bzero(dsphys, sizeof (dsl_dataset_phys_t));
655 dsphys->ds_dir_obj = dd->dd_object;
656 dsphys->ds_flags = flags;
657 dsphys->ds_fsid_guid = unique_create();
658 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
659 sizeof (dsphys->ds_guid));
660 dsphys->ds_snapnames_zapobj =
661 zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP,
662 DMU_OT_NONE, 0, tx);
663 dsphys->ds_creation_time = gethrestime_sec();
664 dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg;
665
666 if (origin == NULL) {
667 dsphys->ds_deadlist_obj = dsl_deadlist_alloc(mos, tx);
668 } else {
669 dsl_dataset_t *ohds; /* head of the origin snapshot */
670
671 dsphys->ds_prev_snap_obj = origin->ds_object;
672 dsphys->ds_prev_snap_txg =
673 origin->ds_phys->ds_creation_txg;
674 dsphys->ds_referenced_bytes =
675 origin->ds_phys->ds_referenced_bytes;
676 dsphys->ds_compressed_bytes =
677 origin->ds_phys->ds_compressed_bytes;
678 dsphys->ds_uncompressed_bytes =
679 origin->ds_phys->ds_uncompressed_bytes;
680 dsphys->ds_bp = origin->ds_phys->ds_bp;
681 dsphys->ds_flags |= origin->ds_phys->ds_flags;
682
683 dmu_buf_will_dirty(origin->ds_dbuf, tx);
684 origin->ds_phys->ds_num_children++;
685
686 VERIFY0(dsl_dataset_hold_obj(dp,
687 origin->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ohds));
688 dsphys->ds_deadlist_obj = dsl_deadlist_clone(&ohds->ds_deadlist,
689 dsphys->ds_prev_snap_txg, dsphys->ds_prev_snap_obj, tx);
690 dsl_dataset_rele(ohds, FTAG);
691
692 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) {
693 if (origin->ds_phys->ds_next_clones_obj == 0) {
694 origin->ds_phys->ds_next_clones_obj =
695 zap_create(mos,
696 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx);
697 }
698 VERIFY0(zap_add_int(mos,
699 origin->ds_phys->ds_next_clones_obj, dsobj, tx));
700 }
701
702 dmu_buf_will_dirty(dd->dd_dbuf, tx);
703 dd->dd_phys->dd_origin_obj = origin->ds_object;
704 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
705 if (origin->ds_dir->dd_phys->dd_clones == 0) {
706 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx);
707 origin->ds_dir->dd_phys->dd_clones =
708 zap_create(mos,
709 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
710 }
711 VERIFY0(zap_add_int(mos,
712 origin->ds_dir->dd_phys->dd_clones, dsobj, tx));
713 }
714 }
715
716 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
717 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
718
719 dmu_buf_rele(dbuf, FTAG);
720
721 dmu_buf_will_dirty(dd->dd_dbuf, tx);
722 dd->dd_phys->dd_head_dataset_obj = dsobj;
723
724 return (dsobj);
725 }
726
727 static void
728 dsl_dataset_zero_zil(dsl_dataset_t *ds, dmu_tx_t *tx)
729 {
730 objset_t *os;
731
732 VERIFY0(dmu_objset_from_ds(ds, &os));
733 bzero(&os->os_zil_header, sizeof (os->os_zil_header));
734 dsl_dataset_dirty(ds, tx);
735 }
736
737 uint64_t
738 dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname,
739 dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx)
740 {
741 dsl_pool_t *dp = pdd->dd_pool;
742 uint64_t dsobj, ddobj;
743 dsl_dir_t *dd;
744
745 ASSERT(dmu_tx_is_syncing(tx));
746 ASSERT(lastname[0] != '@');
747
748 ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx);
749 VERIFY0(dsl_dir_hold_obj(dp, ddobj, lastname, FTAG, &dd));
750
751 dsobj = dsl_dataset_create_sync_dd(dd, origin,
752 flags & ~DS_CREATE_FLAG_NODIRTY, tx);
753
754 dsl_deleg_set_create_perms(dd, tx, cr);
755
756 dsl_dir_rele(dd, FTAG);
757
758 /*
759 * If we are creating a clone, make sure we zero out any stale
760 * data from the origin snapshots zil header.
761 */
762 if (origin != NULL && !(flags & DS_CREATE_FLAG_NODIRTY)) {
763 dsl_dataset_t *ds;
764
765 VERIFY0(dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
766 dsl_dataset_zero_zil(ds, tx);
767 dsl_dataset_rele(ds, FTAG);
768 }
769
770 return (dsobj);
771 }
772
773 /*
774 * The unique space in the head dataset can be calculated by subtracting
775 * the space used in the most recent snapshot, that is still being used
776 * in this file system, from the space currently in use. To figure out
777 * the space in the most recent snapshot still in use, we need to take
778 * the total space used in the snapshot and subtract out the space that
779 * has been freed up since the snapshot was taken.
780 */
781 void
782 dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds)
783 {
784 uint64_t mrs_used;
785 uint64_t dlused, dlcomp, dluncomp;
786
787 ASSERT(!dsl_dataset_is_snapshot(ds));
788
789 if (ds->ds_phys->ds_prev_snap_obj != 0)
790 mrs_used = ds->ds_prev->ds_phys->ds_referenced_bytes;
791 else
792 mrs_used = 0;
793
794 dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp);
795
796 ASSERT3U(dlused, <=, mrs_used);
797 ds->ds_phys->ds_unique_bytes =
798 ds->ds_phys->ds_referenced_bytes - (mrs_used - dlused);
799
800 if (spa_version(ds->ds_dir->dd_pool->dp_spa) >=
801 SPA_VERSION_UNIQUE_ACCURATE)
802 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
803 }
804
805 void
806 dsl_dataset_remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj,
807 dmu_tx_t *tx)
808 {
809 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
810 int err;
811 ASSERTV(uint64_t count);
812
813 ASSERT(ds->ds_phys->ds_num_children >= 2);
814 err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx);
815 /*
816 * The err should not be ENOENT, but a bug in a previous version
817 * of the code could cause upgrade_clones_cb() to not set
818 * ds_next_snap_obj when it should, leading to a missing entry.
819 * If we knew that the pool was created after
820 * SPA_VERSION_NEXT_CLONES, we could assert that it isn't
821 * ENOENT. However, at least we can check that we don't have
822 * too many entries in the next_clones_obj even after failing to
823 * remove this one.
824 */
825 if (err != ENOENT)
826 VERIFY0(err);
827 ASSERT0(zap_count(mos, ds->ds_phys->ds_next_clones_obj,
828 &count));
829 ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2);
830 }
831
832
833 blkptr_t *
834 dsl_dataset_get_blkptr(dsl_dataset_t *ds)
835 {
836 return (&ds->ds_phys->ds_bp);
837 }
838
839 void
840 dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx)
841 {
842 ASSERT(dmu_tx_is_syncing(tx));
843 /* If it's the meta-objset, set dp_meta_rootbp */
844 if (ds == NULL) {
845 tx->tx_pool->dp_meta_rootbp = *bp;
846 } else {
847 dmu_buf_will_dirty(ds->ds_dbuf, tx);
848 ds->ds_phys->ds_bp = *bp;
849 }
850 }
851
852 spa_t *
853 dsl_dataset_get_spa(dsl_dataset_t *ds)
854 {
855 return (ds->ds_dir->dd_pool->dp_spa);
856 }
857
858 void
859 dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx)
860 {
861 dsl_pool_t *dp;
862
863 if (ds == NULL) /* this is the meta-objset */
864 return;
865
866 ASSERT(ds->ds_objset != NULL);
867
868 if (ds->ds_phys->ds_next_snap_obj != 0)
869 panic("dirtying snapshot!");
870
871 dp = ds->ds_dir->dd_pool;
872
873 if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg)) {
874 /* up the hold count until we can be written out */
875 dmu_buf_add_ref(ds->ds_dbuf, ds);
876 }
877 }
878
879 boolean_t
880 dsl_dataset_is_dirty(dsl_dataset_t *ds)
881 {
882 int t;
883
884 for (t = 0; t < TXG_SIZE; t++) {
885 if (txg_list_member(&ds->ds_dir->dd_pool->dp_dirty_datasets,
886 ds, t))
887 return (B_TRUE);
888 }
889 return (B_FALSE);
890 }
891
892 static int
893 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx)
894 {
895 uint64_t asize;
896
897 if (!dmu_tx_is_syncing(tx))
898 return (0);
899
900 /*
901 * If there's an fs-only reservation, any blocks that might become
902 * owned by the snapshot dataset must be accommodated by space
903 * outside of the reservation.
904 */
905 ASSERT(ds->ds_reserved == 0 || DS_UNIQUE_IS_ACCURATE(ds));
906 asize = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
907 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
908 return (SET_ERROR(ENOSPC));
909
910 /*
911 * Propagate any reserved space for this snapshot to other
912 * snapshot checks in this sync group.
913 */
914 if (asize > 0)
915 dsl_dir_willuse_space(ds->ds_dir, asize, tx);
916
917 return (0);
918 }
919
920 typedef struct dsl_dataset_snapshot_arg {
921 nvlist_t *ddsa_snaps;
922 nvlist_t *ddsa_props;
923 nvlist_t *ddsa_errors;
924 } dsl_dataset_snapshot_arg_t;
925
926 int
927 dsl_dataset_snapshot_check_impl(dsl_dataset_t *ds, const char *snapname,
928 dmu_tx_t *tx, boolean_t recv)
929 {
930 int error;
931 uint64_t value;
932
933 ds->ds_trysnap_txg = tx->tx_txg;
934
935 if (!dmu_tx_is_syncing(tx))
936 return (0);
937
938 /*
939 * We don't allow multiple snapshots of the same txg. If there
940 * is already one, try again.
941 */
942 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg)
943 return (SET_ERROR(EAGAIN));
944
945 /*
946 * Check for conflicting snapshot name.
947 */
948 error = dsl_dataset_snap_lookup(ds, snapname, &value);
949 if (error == 0)
950 return (SET_ERROR(EEXIST));
951 if (error != ENOENT)
952 return (error);
953
954 /*
955 * We don't allow taking snapshots of inconsistent datasets, such as
956 * those into which we are currently receiving. However, if we are
957 * creating this snapshot as part of a receive, this check will be
958 * executed atomically with respect to the completion of the receive
959 * itself but prior to the clearing of DS_FLAG_INCONSISTENT; in this
960 * case we ignore this, knowing it will be fixed up for us shortly in
961 * dmu_recv_end_sync().
962 */
963 if (!recv && DS_IS_INCONSISTENT(ds))
964 return (SET_ERROR(EBUSY));
965
966 error = dsl_dataset_snapshot_reserve_space(ds, tx);
967 if (error != 0)
968 return (error);
969
970 return (0);
971 }
972
973 static int
974 dsl_dataset_snapshot_check(void *arg, dmu_tx_t *tx)
975 {
976 dsl_dataset_snapshot_arg_t *ddsa = arg;
977 dsl_pool_t *dp = dmu_tx_pool(tx);
978 nvpair_t *pair;
979 int rv = 0;
980
981 for (pair = nvlist_next_nvpair(ddsa->ddsa_snaps, NULL);
982 pair != NULL; pair = nvlist_next_nvpair(ddsa->ddsa_snaps, pair)) {
983 int error = 0;
984 dsl_dataset_t *ds;
985 char *name, *atp;
986 char dsname[MAXNAMELEN];
987
988 name = nvpair_name(pair);
989 if (strlen(name) >= MAXNAMELEN)
990 error = SET_ERROR(ENAMETOOLONG);
991 if (error == 0) {
992 atp = strchr(name, '@');
993 if (atp == NULL)
994 error = SET_ERROR(EINVAL);
995 if (error == 0)
996 (void) strlcpy(dsname, name, atp - name + 1);
997 }
998 if (error == 0)
999 error = dsl_dataset_hold(dp, dsname, FTAG, &ds);
1000 if (error == 0) {
1001 error = dsl_dataset_snapshot_check_impl(ds,
1002 atp + 1, tx, B_FALSE);
1003 dsl_dataset_rele(ds, FTAG);
1004 }
1005
1006 if (error != 0) {
1007 if (ddsa->ddsa_errors != NULL) {
1008 fnvlist_add_int32(ddsa->ddsa_errors,
1009 name, error);
1010 }
1011 rv = error;
1012 }
1013 }
1014 return (rv);
1015 }
1016
1017 void
1018 dsl_dataset_snapshot_sync_impl(dsl_dataset_t *ds, const char *snapname,
1019 dmu_tx_t *tx)
1020 {
1021 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1022 dmu_buf_t *dbuf;
1023 dsl_dataset_phys_t *dsphys;
1024 uint64_t dsobj, crtxg;
1025 objset_t *mos = dp->dp_meta_objset;
1026 ASSERTV(static zil_header_t zero_zil);
1027 ASSERTV(objset_t *os);
1028
1029 ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
1030
1031 /*
1032 * If we are on an old pool, the zil must not be active, in which
1033 * case it will be zeroed. Usually zil_suspend() accomplishes this.
1034 */
1035 ASSERT(spa_version(dmu_tx_pool(tx)->dp_spa) >= SPA_VERSION_FAST_SNAP ||
1036 dmu_objset_from_ds(ds, &os) != 0 ||
1037 bcmp(&os->os_phys->os_zil_header, &zero_zil,
1038 sizeof (zero_zil)) == 0);
1039
1040
1041 /*
1042 * The origin's ds_creation_txg has to be < TXG_INITIAL
1043 */
1044 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0)
1045 crtxg = 1;
1046 else
1047 crtxg = tx->tx_txg;
1048
1049 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
1050 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
1051 VERIFY0(dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
1052 dmu_buf_will_dirty(dbuf, tx);
1053 dsphys = dbuf->db_data;
1054 bzero(dsphys, sizeof (dsl_dataset_phys_t));
1055 dsphys->ds_dir_obj = ds->ds_dir->dd_object;
1056 dsphys->ds_fsid_guid = unique_create();
1057 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
1058 sizeof (dsphys->ds_guid));
1059 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj;
1060 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg;
1061 dsphys->ds_next_snap_obj = ds->ds_object;
1062 dsphys->ds_num_children = 1;
1063 dsphys->ds_creation_time = gethrestime_sec();
1064 dsphys->ds_creation_txg = crtxg;
1065 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj;
1066 dsphys->ds_referenced_bytes = ds->ds_phys->ds_referenced_bytes;
1067 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes;
1068 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes;
1069 dsphys->ds_flags = ds->ds_phys->ds_flags;
1070 dsphys->ds_bp = ds->ds_phys->ds_bp;
1071 dmu_buf_rele(dbuf, FTAG);
1072
1073 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0);
1074 if (ds->ds_prev) {
1075 uint64_t next_clones_obj =
1076 ds->ds_prev->ds_phys->ds_next_clones_obj;
1077 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj ==
1078 ds->ds_object ||
1079 ds->ds_prev->ds_phys->ds_num_children > 1);
1080 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) {
1081 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
1082 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
1083 ds->ds_prev->ds_phys->ds_creation_txg);
1084 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj;
1085 } else if (next_clones_obj != 0) {
1086 dsl_dataset_remove_from_next_clones(ds->ds_prev,
1087 dsphys->ds_next_snap_obj, tx);
1088 VERIFY0(zap_add_int(mos,
1089 next_clones_obj, dsobj, tx));
1090 }
1091 }
1092
1093 /*
1094 * If we have a reference-reservation on this dataset, we will
1095 * need to increase the amount of refreservation being charged
1096 * since our unique space is going to zero.
1097 */
1098 if (ds->ds_reserved) {
1099 int64_t delta;
1100 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
1101 delta = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
1102 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV,
1103 delta, 0, 0, tx);
1104 }
1105
1106 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1107 ds->ds_phys->ds_deadlist_obj = dsl_deadlist_clone(&ds->ds_deadlist,
1108 UINT64_MAX, ds->ds_phys->ds_prev_snap_obj, tx);
1109 dsl_deadlist_close(&ds->ds_deadlist);
1110 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj);
1111 dsl_deadlist_add_key(&ds->ds_deadlist,
1112 ds->ds_phys->ds_prev_snap_txg, tx);
1113
1114 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg);
1115 ds->ds_phys->ds_prev_snap_obj = dsobj;
1116 ds->ds_phys->ds_prev_snap_txg = crtxg;
1117 ds->ds_phys->ds_unique_bytes = 0;
1118 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
1119 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
1120
1121 VERIFY0(zap_add(mos, ds->ds_phys->ds_snapnames_zapobj,
1122 snapname, 8, 1, &dsobj, tx));
1123
1124 if (ds->ds_prev)
1125 dsl_dataset_rele(ds->ds_prev, ds);
1126 VERIFY0(dsl_dataset_hold_obj(dp,
1127 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev));
1128
1129 dsl_scan_ds_snapshotted(ds, tx);
1130
1131 dsl_dir_snap_cmtime_update(ds->ds_dir);
1132
1133 spa_history_log_internal_ds(ds->ds_prev, "snapshot", tx, "");
1134 }
1135
1136 static void
1137 dsl_dataset_snapshot_sync(void *arg, dmu_tx_t *tx)
1138 {
1139 dsl_dataset_snapshot_arg_t *ddsa = arg;
1140 dsl_pool_t *dp = dmu_tx_pool(tx);
1141 nvpair_t *pair;
1142
1143 for (pair = nvlist_next_nvpair(ddsa->ddsa_snaps, NULL);
1144 pair != NULL; pair = nvlist_next_nvpair(ddsa->ddsa_snaps, pair)) {
1145 dsl_dataset_t *ds;
1146 char *name, *atp;
1147 char dsname[MAXNAMELEN];
1148
1149 name = nvpair_name(pair);
1150 atp = strchr(name, '@');
1151 (void) strlcpy(dsname, name, atp - name + 1);
1152 VERIFY0(dsl_dataset_hold(dp, dsname, FTAG, &ds));
1153
1154 dsl_dataset_snapshot_sync_impl(ds, atp + 1, tx);
1155 if (ddsa->ddsa_props != NULL) {
1156 dsl_props_set_sync_impl(ds->ds_prev,
1157 ZPROP_SRC_LOCAL, ddsa->ddsa_props, tx);
1158 }
1159 dsl_dataset_rele(ds, FTAG);
1160 }
1161 }
1162
1163 /*
1164 * The snapshots must all be in the same pool.
1165 * All-or-nothing: if there are any failures, nothing will be modified.
1166 */
1167 int
1168 dsl_dataset_snapshot(nvlist_t *snaps, nvlist_t *props, nvlist_t *errors)
1169 {
1170 dsl_dataset_snapshot_arg_t ddsa;
1171 nvpair_t *pair;
1172 boolean_t needsuspend;
1173 int error;
1174 spa_t *spa;
1175 char *firstname;
1176 nvlist_t *suspended = NULL;
1177
1178 pair = nvlist_next_nvpair(snaps, NULL);
1179 if (pair == NULL)
1180 return (0);
1181 firstname = nvpair_name(pair);
1182
1183 error = spa_open(firstname, &spa, FTAG);
1184 if (error != 0)
1185 return (error);
1186 needsuspend = (spa_version(spa) < SPA_VERSION_FAST_SNAP);
1187 spa_close(spa, FTAG);
1188
1189 if (needsuspend) {
1190 suspended = fnvlist_alloc();
1191 for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL;
1192 pair = nvlist_next_nvpair(snaps, pair)) {
1193 char fsname[MAXNAMELEN];
1194 char *snapname = nvpair_name(pair);
1195 char *atp;
1196 void *cookie;
1197
1198 atp = strchr(snapname, '@');
1199 if (atp == NULL) {
1200 error = SET_ERROR(EINVAL);
1201 break;
1202 }
1203 (void) strlcpy(fsname, snapname, atp - snapname + 1);
1204
1205 error = zil_suspend(fsname, &cookie);
1206 if (error != 0)
1207 break;
1208 fnvlist_add_uint64(suspended, fsname,
1209 (uintptr_t)cookie);
1210 }
1211 }
1212
1213 ddsa.ddsa_snaps = snaps;
1214 ddsa.ddsa_props = props;
1215 ddsa.ddsa_errors = errors;
1216
1217 if (error == 0) {
1218 error = dsl_sync_task(firstname, dsl_dataset_snapshot_check,
1219 dsl_dataset_snapshot_sync, &ddsa,
1220 fnvlist_num_pairs(snaps) * 3);
1221 }
1222
1223 if (suspended != NULL) {
1224 for (pair = nvlist_next_nvpair(suspended, NULL); pair != NULL;
1225 pair = nvlist_next_nvpair(suspended, pair)) {
1226 zil_resume((void *)(uintptr_t)
1227 fnvpair_value_uint64(pair));
1228 }
1229 fnvlist_free(suspended);
1230 }
1231
1232 #ifdef _KERNEL
1233 if (error == 0) {
1234 for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL;
1235 pair = nvlist_next_nvpair(snaps, pair)) {
1236 char *snapname = nvpair_name(pair);
1237 zvol_create_minors(snapname);
1238 }
1239 }
1240 #endif
1241
1242 return (error);
1243 }
1244
1245 typedef struct dsl_dataset_snapshot_tmp_arg {
1246 const char *ddsta_fsname;
1247 const char *ddsta_snapname;
1248 minor_t ddsta_cleanup_minor;
1249 const char *ddsta_htag;
1250 } dsl_dataset_snapshot_tmp_arg_t;
1251
1252 static int
1253 dsl_dataset_snapshot_tmp_check(void *arg, dmu_tx_t *tx)
1254 {
1255 dsl_dataset_snapshot_tmp_arg_t *ddsta = arg;
1256 dsl_pool_t *dp = dmu_tx_pool(tx);
1257 dsl_dataset_t *ds;
1258 int error;
1259
1260 error = dsl_dataset_hold(dp, ddsta->ddsta_fsname, FTAG, &ds);
1261 if (error != 0)
1262 return (error);
1263
1264 error = dsl_dataset_snapshot_check_impl(ds, ddsta->ddsta_snapname,
1265 tx, B_FALSE);
1266 if (error != 0) {
1267 dsl_dataset_rele(ds, FTAG);
1268 return (error);
1269 }
1270
1271 if (spa_version(dp->dp_spa) < SPA_VERSION_USERREFS) {
1272 dsl_dataset_rele(ds, FTAG);
1273 return (SET_ERROR(ENOTSUP));
1274 }
1275 error = dsl_dataset_user_hold_check_one(NULL, ddsta->ddsta_htag,
1276 B_TRUE, tx);
1277 if (error != 0) {
1278 dsl_dataset_rele(ds, FTAG);
1279 return (error);
1280 }
1281
1282 dsl_dataset_rele(ds, FTAG);
1283 return (0);
1284 }
1285
1286 static void
1287 dsl_dataset_snapshot_tmp_sync(void *arg, dmu_tx_t *tx)
1288 {
1289 dsl_dataset_snapshot_tmp_arg_t *ddsta = arg;
1290 dsl_pool_t *dp = dmu_tx_pool(tx);
1291 dsl_dataset_t *ds;
1292
1293 VERIFY0(dsl_dataset_hold(dp, ddsta->ddsta_fsname, FTAG, &ds));
1294
1295 dsl_dataset_snapshot_sync_impl(ds, ddsta->ddsta_snapname, tx);
1296 dsl_dataset_user_hold_sync_one(ds->ds_prev, ddsta->ddsta_htag,
1297 ddsta->ddsta_cleanup_minor, gethrestime_sec(), tx);
1298 dsl_destroy_snapshot_sync_impl(ds->ds_prev, B_TRUE, tx);
1299
1300 dsl_dataset_rele(ds, FTAG);
1301 }
1302
1303 int
1304 dsl_dataset_snapshot_tmp(const char *fsname, const char *snapname,
1305 minor_t cleanup_minor, const char *htag)
1306 {
1307 dsl_dataset_snapshot_tmp_arg_t ddsta;
1308 int error;
1309 spa_t *spa;
1310 boolean_t needsuspend;
1311 void *cookie;
1312
1313 ddsta.ddsta_fsname = fsname;
1314 ddsta.ddsta_snapname = snapname;
1315 ddsta.ddsta_cleanup_minor = cleanup_minor;
1316 ddsta.ddsta_htag = htag;
1317
1318 error = spa_open(fsname, &spa, FTAG);
1319 if (error != 0)
1320 return (error);
1321 needsuspend = (spa_version(spa) < SPA_VERSION_FAST_SNAP);
1322 spa_close(spa, FTAG);
1323
1324 if (needsuspend) {
1325 error = zil_suspend(fsname, &cookie);
1326 if (error != 0)
1327 return (error);
1328 }
1329
1330 error = dsl_sync_task(fsname, dsl_dataset_snapshot_tmp_check,
1331 dsl_dataset_snapshot_tmp_sync, &ddsta, 3);
1332
1333 if (needsuspend)
1334 zil_resume(cookie);
1335 return (error);
1336 }
1337
1338
1339 void
1340 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx)
1341 {
1342 ASSERT(dmu_tx_is_syncing(tx));
1343 ASSERT(ds->ds_objset != NULL);
1344 ASSERT(ds->ds_phys->ds_next_snap_obj == 0);
1345
1346 /*
1347 * in case we had to change ds_fsid_guid when we opened it,
1348 * sync it out now.
1349 */
1350 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1351 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid;
1352
1353 dmu_objset_sync(ds->ds_objset, zio, tx);
1354 }
1355
1356 static void
1357 get_clones_stat(dsl_dataset_t *ds, nvlist_t *nv)
1358 {
1359 uint64_t count = 0;
1360 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1361 zap_cursor_t zc;
1362 zap_attribute_t za;
1363 nvlist_t *propval = fnvlist_alloc();
1364 nvlist_t *val = fnvlist_alloc();
1365
1366 ASSERT(dsl_pool_config_held(ds->ds_dir->dd_pool));
1367
1368 /*
1369 * There may be missing entries in ds_next_clones_obj
1370 * due to a bug in a previous version of the code.
1371 * Only trust it if it has the right number of entries.
1372 */
1373 if (ds->ds_phys->ds_next_clones_obj != 0) {
1374 ASSERT0(zap_count(mos, ds->ds_phys->ds_next_clones_obj,
1375 &count));
1376 }
1377 if (count != ds->ds_phys->ds_num_children - 1)
1378 goto fail;
1379 for (zap_cursor_init(&zc, mos, ds->ds_phys->ds_next_clones_obj);
1380 zap_cursor_retrieve(&zc, &za) == 0;
1381 zap_cursor_advance(&zc)) {
1382 dsl_dataset_t *clone;
1383 char buf[ZFS_MAXNAMELEN];
1384 VERIFY0(dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
1385 za.za_first_integer, FTAG, &clone));
1386 dsl_dir_name(clone->ds_dir, buf);
1387 fnvlist_add_boolean(val, buf);
1388 dsl_dataset_rele(clone, FTAG);
1389 }
1390 zap_cursor_fini(&zc);
1391 fnvlist_add_nvlist(propval, ZPROP_VALUE, val);
1392 fnvlist_add_nvlist(nv, zfs_prop_to_name(ZFS_PROP_CLONES), propval);
1393 fail:
1394 nvlist_free(val);
1395 nvlist_free(propval);
1396 }
1397
1398 void
1399 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv)
1400 {
1401 uint64_t refd, avail, uobjs, aobjs, ratio;
1402 ASSERTV(dsl_pool_t *dp = ds->ds_dir->dd_pool);
1403
1404 ASSERT(dsl_pool_config_held(dp));
1405
1406 ratio = ds->ds_phys->ds_compressed_bytes == 0 ? 100 :
1407 (ds->ds_phys->ds_uncompressed_bytes * 100 /
1408 ds->ds_phys->ds_compressed_bytes);
1409
1410 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRATIO, ratio);
1411 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_LOGICALREFERENCED,
1412 ds->ds_phys->ds_uncompressed_bytes);
1413
1414 if (dsl_dataset_is_snapshot(ds)) {
1415 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, ratio);
1416 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED,
1417 ds->ds_phys->ds_unique_bytes);
1418 get_clones_stat(ds, nv);
1419 } else {
1420 dsl_dir_stats(ds->ds_dir, nv);
1421 }
1422
1423 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs);
1424 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail);
1425 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd);
1426
1427 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION,
1428 ds->ds_phys->ds_creation_time);
1429 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG,
1430 ds->ds_phys->ds_creation_txg);
1431 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA,
1432 ds->ds_quota);
1433 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION,
1434 ds->ds_reserved);
1435 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID,
1436 ds->ds_phys->ds_guid);
1437 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE,
1438 ds->ds_phys->ds_unique_bytes);
1439 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID,
1440 ds->ds_object);
1441 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS,
1442 ds->ds_userrefs);
1443 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY,
1444 DS_IS_DEFER_DESTROY(ds) ? 1 : 0);
1445
1446 if (ds->ds_phys->ds_prev_snap_obj != 0) {
1447 uint64_t written, comp, uncomp;
1448 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1449 dsl_dataset_t *prev;
1450 int err;
1451
1452 err = dsl_dataset_hold_obj(dp,
1453 ds->ds_phys->ds_prev_snap_obj, FTAG, &prev);
1454 if (err == 0) {
1455 err = dsl_dataset_space_written(prev, ds, &written,
1456 &comp, &uncomp);
1457 dsl_dataset_rele(prev, FTAG);
1458 if (err == 0) {
1459 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_WRITTEN,
1460 written);
1461 }
1462 }
1463 }
1464
1465 }
1466
1467 void
1468 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat)
1469 {
1470 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1471 ASSERT(dsl_pool_config_held(dp));
1472
1473 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg;
1474 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT;
1475 stat->dds_guid = ds->ds_phys->ds_guid;
1476 stat->dds_origin[0] = '\0';
1477 if (dsl_dataset_is_snapshot(ds)) {
1478 stat->dds_is_snapshot = B_TRUE;
1479 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1;
1480 } else {
1481 stat->dds_is_snapshot = B_FALSE;
1482 stat->dds_num_clones = 0;
1483
1484 if (dsl_dir_is_clone(ds->ds_dir)) {
1485 dsl_dataset_t *ods;
1486
1487 VERIFY0(dsl_dataset_hold_obj(dp,
1488 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods));
1489 dsl_dataset_name(ods, stat->dds_origin);
1490 dsl_dataset_rele(ods, FTAG);
1491 }
1492 }
1493 }
1494
1495 uint64_t
1496 dsl_dataset_fsid_guid(dsl_dataset_t *ds)
1497 {
1498 return (ds->ds_fsid_guid);
1499 }
1500
1501 void
1502 dsl_dataset_space(dsl_dataset_t *ds,
1503 uint64_t *refdbytesp, uint64_t *availbytesp,
1504 uint64_t *usedobjsp, uint64_t *availobjsp)
1505 {
1506 *refdbytesp = ds->ds_phys->ds_referenced_bytes;
1507 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE);
1508 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes)
1509 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes;
1510 if (ds->ds_quota != 0) {
1511 /*
1512 * Adjust available bytes according to refquota
1513 */
1514 if (*refdbytesp < ds->ds_quota)
1515 *availbytesp = MIN(*availbytesp,
1516 ds->ds_quota - *refdbytesp);
1517 else
1518 *availbytesp = 0;
1519 }
1520 *usedobjsp = ds->ds_phys->ds_bp.blk_fill;
1521 *availobjsp = DN_MAX_OBJECT - *usedobjsp;
1522 }
1523
1524 boolean_t
1525 dsl_dataset_modified_since_snap(dsl_dataset_t *ds, dsl_dataset_t *snap)
1526 {
1527 ASSERT(dsl_pool_config_held(ds->ds_dir->dd_pool));
1528 if (snap == NULL)
1529 return (B_FALSE);
1530 if (ds->ds_phys->ds_bp.blk_birth >
1531 snap->ds_phys->ds_creation_txg) {
1532 objset_t *os, *os_snap;
1533 /*
1534 * It may be that only the ZIL differs, because it was
1535 * reset in the head. Don't count that as being
1536 * modified.
1537 */
1538 if (dmu_objset_from_ds(ds, &os) != 0)
1539 return (B_TRUE);
1540 if (dmu_objset_from_ds(snap, &os_snap) != 0)
1541 return (B_TRUE);
1542 return (bcmp(&os->os_phys->os_meta_dnode,
1543 &os_snap->os_phys->os_meta_dnode,
1544 sizeof (os->os_phys->os_meta_dnode)) != 0);
1545 }
1546 return (B_FALSE);
1547 }
1548
1549 typedef struct dsl_dataset_rename_snapshot_arg {
1550 const char *ddrsa_fsname;
1551 const char *ddrsa_oldsnapname;
1552 const char *ddrsa_newsnapname;
1553 boolean_t ddrsa_recursive;
1554 dmu_tx_t *ddrsa_tx;
1555 } dsl_dataset_rename_snapshot_arg_t;
1556
1557 /* ARGSUSED */
1558 static int
1559 dsl_dataset_rename_snapshot_check_impl(dsl_pool_t *dp,
1560 dsl_dataset_t *hds, void *arg)
1561 {
1562 dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
1563 int error;
1564 uint64_t val;
1565
1566 error = dsl_dataset_snap_lookup(hds, ddrsa->ddrsa_oldsnapname, &val);
1567 if (error != 0) {
1568 /* ignore nonexistent snapshots */
1569 return (error == ENOENT ? 0 : error);
1570 }
1571
1572 /* new name should not exist */
1573 error = dsl_dataset_snap_lookup(hds, ddrsa->ddrsa_newsnapname, &val);
1574 if (error == 0)
1575 error = SET_ERROR(EEXIST);
1576 else if (error == ENOENT)
1577 error = 0;
1578
1579 /* dataset name + 1 for the "@" + the new snapshot name must fit */
1580 if (dsl_dir_namelen(hds->ds_dir) + 1 +
1581 strlen(ddrsa->ddrsa_newsnapname) >= MAXNAMELEN)
1582 error = SET_ERROR(ENAMETOOLONG);
1583
1584 return (error);
1585 }
1586
1587 static int
1588 dsl_dataset_rename_snapshot_check(void *arg, dmu_tx_t *tx)
1589 {
1590 dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
1591 dsl_pool_t *dp = dmu_tx_pool(tx);
1592 dsl_dataset_t *hds;
1593 int error;
1594
1595 error = dsl_dataset_hold(dp, ddrsa->ddrsa_fsname, FTAG, &hds);
1596 if (error != 0)
1597 return (error);
1598
1599 if (ddrsa->ddrsa_recursive) {
1600 error = dmu_objset_find_dp(dp, hds->ds_dir->dd_object,
1601 dsl_dataset_rename_snapshot_check_impl, ddrsa,
1602 DS_FIND_CHILDREN);
1603 } else {
1604 error = dsl_dataset_rename_snapshot_check_impl(dp, hds, ddrsa);
1605 }
1606 dsl_dataset_rele(hds, FTAG);
1607 return (error);
1608 }
1609
1610 static int
1611 dsl_dataset_rename_snapshot_sync_impl(dsl_pool_t *dp,
1612 dsl_dataset_t *hds, void *arg)
1613 {
1614 #ifdef _KERNEL
1615 char *oldname, *newname;
1616 #endif
1617 dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
1618 dsl_dataset_t *ds;
1619 uint64_t val;
1620 dmu_tx_t *tx = ddrsa->ddrsa_tx;
1621 int error;
1622
1623 error = dsl_dataset_snap_lookup(hds, ddrsa->ddrsa_oldsnapname, &val);
1624 ASSERT(error == 0 || error == ENOENT);
1625 if (error == ENOENT) {
1626 /* ignore nonexistent snapshots */
1627 return (0);
1628 }
1629
1630 VERIFY0(dsl_dataset_hold_obj(dp, val, FTAG, &ds));
1631
1632 /* log before we change the name */
1633 spa_history_log_internal_ds(ds, "rename", tx,
1634 "-> @%s", ddrsa->ddrsa_newsnapname);
1635
1636 VERIFY0(dsl_dataset_snap_remove(hds, ddrsa->ddrsa_oldsnapname, tx));
1637 mutex_enter(&ds->ds_lock);
1638 (void) strcpy(ds->ds_snapname, ddrsa->ddrsa_newsnapname);
1639 mutex_exit(&ds->ds_lock);
1640 VERIFY0(zap_add(dp->dp_meta_objset, hds->ds_phys->ds_snapnames_zapobj,
1641 ds->ds_snapname, 8, 1, &ds->ds_object, tx));
1642
1643 #ifdef _KERNEL
1644 oldname = kmem_alloc(MAXPATHLEN, KM_PUSHPAGE);
1645 newname = kmem_alloc(MAXPATHLEN, KM_PUSHPAGE);
1646 snprintf(oldname, MAXPATHLEN, "%s@%s", ddrsa->ddrsa_fsname,
1647 ddrsa->ddrsa_oldsnapname);
1648 snprintf(newname, MAXPATHLEN, "%s@%s", ddrsa->ddrsa_fsname,
1649 ddrsa->ddrsa_newsnapname);
1650 zvol_rename_minors(oldname, newname);
1651 kmem_free(newname, MAXPATHLEN);
1652 kmem_free(oldname, MAXPATHLEN);
1653 #endif
1654
1655 dsl_dataset_rele(ds, FTAG);
1656 return (0);
1657 }
1658
1659 static void
1660 dsl_dataset_rename_snapshot_sync(void *arg, dmu_tx_t *tx)
1661 {
1662 dsl_dataset_rename_snapshot_arg_t *ddrsa = arg;
1663 dsl_pool_t *dp = dmu_tx_pool(tx);
1664 dsl_dataset_t *hds;
1665
1666 VERIFY0(dsl_dataset_hold(dp, ddrsa->ddrsa_fsname, FTAG, &hds));
1667 ddrsa->ddrsa_tx = tx;
1668 if (ddrsa->ddrsa_recursive) {
1669 VERIFY0(dmu_objset_find_dp(dp, hds->ds_dir->dd_object,
1670 dsl_dataset_rename_snapshot_sync_impl, ddrsa,
1671 DS_FIND_CHILDREN));
1672 } else {
1673 VERIFY0(dsl_dataset_rename_snapshot_sync_impl(dp, hds, ddrsa));
1674 }
1675 dsl_dataset_rele(hds, FTAG);
1676 }
1677
1678 int
1679 dsl_dataset_rename_snapshot(const char *fsname,
1680 const char *oldsnapname, const char *newsnapname, boolean_t recursive)
1681 {
1682 dsl_dataset_rename_snapshot_arg_t ddrsa;
1683
1684 ddrsa.ddrsa_fsname = fsname;
1685 ddrsa.ddrsa_oldsnapname = oldsnapname;
1686 ddrsa.ddrsa_newsnapname = newsnapname;
1687 ddrsa.ddrsa_recursive = recursive;
1688
1689 return (dsl_sync_task(fsname, dsl_dataset_rename_snapshot_check,
1690 dsl_dataset_rename_snapshot_sync, &ddrsa, 1));
1691 }
1692
1693 /*
1694 * If we're doing an ownership handoff, we need to make sure that there is
1695 * only one long hold on the dataset. We're not allowed to change anything here
1696 * so we don't permanently release the long hold or regular hold here. We want
1697 * to do this only when syncing to avoid the dataset unexpectedly going away
1698 * when we release the long hold.
1699 */
1700 static int
1701 dsl_dataset_handoff_check(dsl_dataset_t *ds, void *owner, dmu_tx_t *tx)
1702 {
1703 boolean_t held;
1704
1705 if (!dmu_tx_is_syncing(tx))
1706 return (0);
1707
1708 if (owner != NULL) {
1709 VERIFY3P(ds->ds_owner, ==, owner);
1710 dsl_dataset_long_rele(ds, owner);
1711 }
1712
1713 held = dsl_dataset_long_held(ds);
1714
1715 if (owner != NULL)
1716 dsl_dataset_long_hold(ds, owner);
1717
1718 if (held)
1719 return (SET_ERROR(EBUSY));
1720
1721 return (0);
1722 }
1723
1724 typedef struct dsl_dataset_rollback_arg {
1725 const char *ddra_fsname;
1726 void *ddra_owner;
1727 nvlist_t *ddra_result;
1728 } dsl_dataset_rollback_arg_t;
1729
1730 static int
1731 dsl_dataset_rollback_check(void *arg, dmu_tx_t *tx)
1732 {
1733 dsl_dataset_rollback_arg_t *ddra = arg;
1734 dsl_pool_t *dp = dmu_tx_pool(tx);
1735 dsl_dataset_t *ds;
1736 int64_t unused_refres_delta;
1737 int error;
1738
1739 error = dsl_dataset_hold(dp, ddra->ddra_fsname, FTAG, &ds);
1740 if (error != 0)
1741 return (error);
1742
1743 /* must not be a snapshot */
1744 if (dsl_dataset_is_snapshot(ds)) {
1745 dsl_dataset_rele(ds, FTAG);
1746 return (SET_ERROR(EINVAL));
1747 }
1748
1749 /* must have a most recent snapshot */
1750 if (ds->ds_phys->ds_prev_snap_txg < TXG_INITIAL) {
1751 dsl_dataset_rele(ds, FTAG);
1752 return (SET_ERROR(EINVAL));
1753 }
1754
1755 error = dsl_dataset_handoff_check(ds, ddra->ddra_owner, tx);
1756 if (error != 0) {
1757 dsl_dataset_rele(ds, FTAG);
1758 return (error);
1759 }
1760
1761 /*
1762 * Check if the snap we are rolling back to uses more than
1763 * the refquota.
1764 */
1765 if (ds->ds_quota != 0 &&
1766 ds->ds_prev->ds_phys->ds_referenced_bytes > ds->ds_quota) {
1767 dsl_dataset_rele(ds, FTAG);
1768 return (SET_ERROR(EDQUOT));
1769 }
1770
1771 /*
1772 * When we do the clone swap, we will temporarily use more space
1773 * due to the refreservation (the head will no longer have any
1774 * unique space, so the entire amount of the refreservation will need
1775 * to be free). We will immediately destroy the clone, freeing
1776 * this space, but the freeing happens over many txg's.
1777 */
1778 unused_refres_delta = (int64_t)MIN(ds->ds_reserved,
1779 ds->ds_phys->ds_unique_bytes);
1780
1781 if (unused_refres_delta > 0 &&
1782 unused_refres_delta >
1783 dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE)) {
1784 dsl_dataset_rele(ds, FTAG);
1785 return (SET_ERROR(ENOSPC));
1786 }
1787
1788 dsl_dataset_rele(ds, FTAG);
1789 return (0);
1790 }
1791
1792 static void
1793 dsl_dataset_rollback_sync(void *arg, dmu_tx_t *tx)
1794 {
1795 dsl_dataset_rollback_arg_t *ddra = arg;
1796 dsl_pool_t *dp = dmu_tx_pool(tx);
1797 dsl_dataset_t *ds, *clone;
1798 uint64_t cloneobj;
1799 char namebuf[ZFS_MAXNAMELEN];
1800
1801 VERIFY0(dsl_dataset_hold(dp, ddra->ddra_fsname, FTAG, &ds));
1802
1803 dsl_dataset_name(ds->ds_prev, namebuf);
1804 fnvlist_add_string(ddra->ddra_result, "target", namebuf);
1805
1806 cloneobj = dsl_dataset_create_sync(ds->ds_dir, "%rollback",
1807 ds->ds_prev, DS_CREATE_FLAG_NODIRTY, kcred, tx);
1808
1809 VERIFY0(dsl_dataset_hold_obj(dp, cloneobj, FTAG, &clone));
1810
1811 dsl_dataset_clone_swap_sync_impl(clone, ds, tx);
1812 dsl_dataset_zero_zil(ds, tx);
1813
1814 dsl_destroy_head_sync_impl(clone, tx);
1815
1816 dsl_dataset_rele(clone, FTAG);
1817 dsl_dataset_rele(ds, FTAG);
1818 }
1819
1820 /*
1821 * Rolls back the given filesystem or volume to the most recent snapshot.
1822 * The name of the most recent snapshot will be returned under key "target"
1823 * in the result nvlist.
1824 *
1825 * If owner != NULL:
1826 * - The existing dataset MUST be owned by the specified owner at entry
1827 * - Upon return, dataset will still be held by the same owner, whether we
1828 * succeed or not.
1829 *
1830 * This mode is required any time the existing filesystem is mounted. See
1831 * notes above zfs_suspend_fs() for further details.
1832 */
1833 int
1834 dsl_dataset_rollback(const char *fsname, void *owner, nvlist_t *result)
1835 {
1836 dsl_dataset_rollback_arg_t ddra;
1837
1838 ddra.ddra_fsname = fsname;
1839 ddra.ddra_owner = owner;
1840 ddra.ddra_result = result;
1841
1842 return (dsl_sync_task(fsname, dsl_dataset_rollback_check,
1843 dsl_dataset_rollback_sync, &ddra, 1));
1844 }
1845
1846 struct promotenode {
1847 list_node_t link;
1848 dsl_dataset_t *ds;
1849 };
1850
1851 typedef struct dsl_dataset_promote_arg {
1852 const char *ddpa_clonename;
1853 dsl_dataset_t *ddpa_clone;
1854 list_t shared_snaps, origin_snaps, clone_snaps;
1855 dsl_dataset_t *origin_origin; /* origin of the origin */
1856 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap;
1857 char *err_ds;
1858 } dsl_dataset_promote_arg_t;
1859
1860 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep);
1861 static int promote_hold(dsl_dataset_promote_arg_t *ddpa, dsl_pool_t *dp,
1862 void *tag);
1863 static void promote_rele(dsl_dataset_promote_arg_t *ddpa, void *tag);
1864
1865 static int
1866 dsl_dataset_promote_check(void *arg, dmu_tx_t *tx)
1867 {
1868 dsl_dataset_promote_arg_t *ddpa = arg;
1869 dsl_pool_t *dp = dmu_tx_pool(tx);
1870 dsl_dataset_t *hds;
1871 struct promotenode *snap;
1872 dsl_dataset_t *origin_ds;
1873 int err;
1874 uint64_t unused;
1875
1876 err = promote_hold(ddpa, dp, FTAG);
1877 if (err != 0)
1878 return (err);
1879
1880 hds = ddpa->ddpa_clone;
1881
1882 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE) {
1883 promote_rele(ddpa, FTAG);
1884 return (SET_ERROR(EXDEV));
1885 }
1886
1887 /*
1888 * Compute and check the amount of space to transfer. Since this is
1889 * so expensive, don't do the preliminary check.
1890 */
1891 if (!dmu_tx_is_syncing(tx)) {
1892 promote_rele(ddpa, FTAG);
1893 return (0);
1894 }
1895
1896 snap = list_head(&ddpa->shared_snaps);
1897 origin_ds = snap->ds;
1898
1899 /* compute origin's new unique space */
1900 snap = list_tail(&ddpa->clone_snaps);
1901 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
1902 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
1903 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX,
1904 &ddpa->unique, &unused, &unused);
1905
1906 /*
1907 * Walk the snapshots that we are moving
1908 *
1909 * Compute space to transfer. Consider the incremental changes
1910 * to used by each snapshot:
1911 * (my used) = (prev's used) + (blocks born) - (blocks killed)
1912 * So each snapshot gave birth to:
1913 * (blocks born) = (my used) - (prev's used) + (blocks killed)
1914 * So a sequence would look like:
1915 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0)
1916 * Which simplifies to:
1917 * uN + kN + kN-1 + ... + k1 + k0
1918 * Note however, if we stop before we reach the ORIGIN we get:
1919 * uN + kN + kN-1 + ... + kM - uM-1
1920 */
1921 ddpa->used = origin_ds->ds_phys->ds_referenced_bytes;
1922 ddpa->comp = origin_ds->ds_phys->ds_compressed_bytes;
1923 ddpa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes;
1924 for (snap = list_head(&ddpa->shared_snaps); snap;
1925 snap = list_next(&ddpa->shared_snaps, snap)) {
1926 uint64_t val, dlused, dlcomp, dluncomp;
1927 dsl_dataset_t *ds = snap->ds;
1928
1929 /*
1930 * If there are long holds, we won't be able to evict
1931 * the objset.
1932 */
1933 if (dsl_dataset_long_held(ds)) {
1934 err = SET_ERROR(EBUSY);
1935 goto out;
1936 }
1937
1938 /* Check that the snapshot name does not conflict */
1939 VERIFY0(dsl_dataset_get_snapname(ds));
1940 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val);
1941 if (err == 0) {
1942 (void) strcpy(ddpa->err_ds, snap->ds->ds_snapname);
1943 err = SET_ERROR(EEXIST);
1944 goto out;
1945 }
1946 if (err != ENOENT)
1947 goto out;
1948
1949 /* The very first snapshot does not have a deadlist */
1950 if (ds->ds_phys->ds_prev_snap_obj == 0)
1951 continue;
1952
1953 dsl_deadlist_space(&ds->ds_deadlist,
1954 &dlused, &dlcomp, &dluncomp);
1955 ddpa->used += dlused;
1956 ddpa->comp += dlcomp;
1957 ddpa->uncomp += dluncomp;
1958 }
1959
1960 /*
1961 * If we are a clone of a clone then we never reached ORIGIN,
1962 * so we need to subtract out the clone origin's used space.
1963 */
1964 if (ddpa->origin_origin) {
1965 ddpa->used -= ddpa->origin_origin->ds_phys->ds_referenced_bytes;
1966 ddpa->comp -= ddpa->origin_origin->ds_phys->ds_compressed_bytes;
1967 ddpa->uncomp -=
1968 ddpa->origin_origin->ds_phys->ds_uncompressed_bytes;
1969 }
1970
1971 /* Check that there is enough space here */
1972 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir,
1973 ddpa->used);
1974 if (err != 0)
1975 goto out;
1976
1977 /*
1978 * Compute the amounts of space that will be used by snapshots
1979 * after the promotion (for both origin and clone). For each,
1980 * it is the amount of space that will be on all of their
1981 * deadlists (that was not born before their new origin).
1982 */
1983 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
1984 uint64_t space;
1985
1986 /*
1987 * Note, typically this will not be a clone of a clone,
1988 * so dd_origin_txg will be < TXG_INITIAL, so
1989 * these snaplist_space() -> dsl_deadlist_space_range()
1990 * calls will be fast because they do not have to
1991 * iterate over all bps.
1992 */
1993 snap = list_head(&ddpa->origin_snaps);
1994 err = snaplist_space(&ddpa->shared_snaps,
1995 snap->ds->ds_dir->dd_origin_txg, &ddpa->cloneusedsnap);
1996 if (err != 0)
1997 goto out;
1998
1999 err = snaplist_space(&ddpa->clone_snaps,
2000 snap->ds->ds_dir->dd_origin_txg, &space);
2001 if (err != 0)
2002 goto out;
2003 ddpa->cloneusedsnap += space;
2004 }
2005 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2006 err = snaplist_space(&ddpa->origin_snaps,
2007 origin_ds->ds_phys->ds_creation_txg, &ddpa->originusedsnap);
2008 if (err != 0)
2009 goto out;
2010 }
2011
2012 out:
2013 promote_rele(ddpa, FTAG);
2014 return (err);
2015 }
2016
2017 static void
2018 dsl_dataset_promote_sync(void *arg, dmu_tx_t *tx)
2019 {
2020 dsl_dataset_promote_arg_t *ddpa = arg;
2021 dsl_pool_t *dp = dmu_tx_pool(tx);
2022 dsl_dataset_t *hds;
2023 struct promotenode *snap;
2024 dsl_dataset_t *origin_ds;
2025 dsl_dataset_t *origin_head;
2026 dsl_dir_t *dd;
2027 dsl_dir_t *odd = NULL;
2028 uint64_t oldnext_obj;
2029 int64_t delta;
2030
2031 VERIFY0(promote_hold(ddpa, dp, FTAG));
2032 hds = ddpa->ddpa_clone;
2033
2034 ASSERT0(hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE);
2035
2036 snap = list_head(&ddpa->shared_snaps);
2037 origin_ds = snap->ds;
2038 dd = hds->ds_dir;
2039
2040 snap = list_head(&ddpa->origin_snaps);
2041 origin_head = snap->ds;
2042
2043 /*
2044 * We need to explicitly open odd, since origin_ds's dd will be
2045 * changing.
2046 */
2047 VERIFY0(dsl_dir_hold_obj(dp, origin_ds->ds_dir->dd_object,
2048 NULL, FTAG, &odd));
2049
2050 /* change origin's next snap */
2051 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx);
2052 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj;
2053 snap = list_tail(&ddpa->clone_snaps);
2054 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2055 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object;
2056
2057 /* change the origin's next clone */
2058 if (origin_ds->ds_phys->ds_next_clones_obj) {
2059 dsl_dataset_remove_from_next_clones(origin_ds,
2060 snap->ds->ds_object, tx);
2061 VERIFY0(zap_add_int(dp->dp_meta_objset,
2062 origin_ds->ds_phys->ds_next_clones_obj,
2063 oldnext_obj, tx));
2064 }
2065
2066 /* change origin */
2067 dmu_buf_will_dirty(dd->dd_dbuf, tx);
2068 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object);
2069 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj;
2070 dd->dd_origin_txg = origin_head->ds_dir->dd_origin_txg;
2071 dmu_buf_will_dirty(odd->dd_dbuf, tx);
2072 odd->dd_phys->dd_origin_obj = origin_ds->ds_object;
2073 origin_head->ds_dir->dd_origin_txg =
2074 origin_ds->ds_phys->ds_creation_txg;
2075
2076 /* change dd_clone entries */
2077 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2078 VERIFY0(zap_remove_int(dp->dp_meta_objset,
2079 odd->dd_phys->dd_clones, hds->ds_object, tx));
2080 VERIFY0(zap_add_int(dp->dp_meta_objset,
2081 ddpa->origin_origin->ds_dir->dd_phys->dd_clones,
2082 hds->ds_object, tx));
2083
2084 VERIFY0(zap_remove_int(dp->dp_meta_objset,
2085 ddpa->origin_origin->ds_dir->dd_phys->dd_clones,
2086 origin_head->ds_object, tx));
2087 if (dd->dd_phys->dd_clones == 0) {
2088 dd->dd_phys->dd_clones = zap_create(dp->dp_meta_objset,
2089 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
2090 }
2091 VERIFY0(zap_add_int(dp->dp_meta_objset,
2092 dd->dd_phys->dd_clones, origin_head->ds_object, tx));
2093 }
2094
2095 /* move snapshots to this dir */
2096 for (snap = list_head(&ddpa->shared_snaps); snap;
2097 snap = list_next(&ddpa->shared_snaps, snap)) {
2098 dsl_dataset_t *ds = snap->ds;
2099
2100 /*
2101 * Property callbacks are registered to a particular
2102 * dsl_dir. Since ours is changing, evict the objset
2103 * so that they will be unregistered from the old dsl_dir.
2104 */
2105 if (ds->ds_objset) {
2106 dmu_objset_evict(ds->ds_objset);
2107 ds->ds_objset = NULL;
2108 }
2109
2110 /* move snap name entry */
2111 VERIFY0(dsl_dataset_get_snapname(ds));
2112 VERIFY0(dsl_dataset_snap_remove(origin_head,
2113 ds->ds_snapname, tx));
2114 VERIFY0(zap_add(dp->dp_meta_objset,
2115 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname,
2116 8, 1, &ds->ds_object, tx));
2117
2118 /* change containing dsl_dir */
2119 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2120 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object);
2121 ds->ds_phys->ds_dir_obj = dd->dd_object;
2122 ASSERT3P(ds->ds_dir, ==, odd);
2123 dsl_dir_rele(ds->ds_dir, ds);
2124 VERIFY0(dsl_dir_hold_obj(dp, dd->dd_object,
2125 NULL, ds, &ds->ds_dir));
2126
2127 /* move any clone references */
2128 if (ds->ds_phys->ds_next_clones_obj &&
2129 spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2130 zap_cursor_t zc;
2131 zap_attribute_t za;
2132
2133 for (zap_cursor_init(&zc, dp->dp_meta_objset,
2134 ds->ds_phys->ds_next_clones_obj);
2135 zap_cursor_retrieve(&zc, &za) == 0;
2136 zap_cursor_advance(&zc)) {
2137 dsl_dataset_t *cnds;
2138 uint64_t o;
2139
2140 if (za.za_first_integer == oldnext_obj) {
2141 /*
2142 * We've already moved the
2143 * origin's reference.
2144 */
2145 continue;
2146 }
2147
2148 VERIFY0(dsl_dataset_hold_obj(dp,
2149 za.za_first_integer, FTAG, &cnds));
2150 o = cnds->ds_dir->dd_phys->dd_head_dataset_obj;
2151
2152 VERIFY0(zap_remove_int(dp->dp_meta_objset,
2153 odd->dd_phys->dd_clones, o, tx));
2154 VERIFY0(zap_add_int(dp->dp_meta_objset,
2155 dd->dd_phys->dd_clones, o, tx));
2156 dsl_dataset_rele(cnds, FTAG);
2157 }
2158 zap_cursor_fini(&zc);
2159 }
2160
2161 ASSERT(!dsl_prop_hascb(ds));
2162 }
2163
2164 /*
2165 * Change space accounting.
2166 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either
2167 * both be valid, or both be 0 (resulting in delta == 0). This
2168 * is true for each of {clone,origin} independently.
2169 */
2170
2171 delta = ddpa->cloneusedsnap -
2172 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2173 ASSERT3S(delta, >=, 0);
2174 ASSERT3U(ddpa->used, >=, delta);
2175 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx);
2176 dsl_dir_diduse_space(dd, DD_USED_HEAD,
2177 ddpa->used - delta, ddpa->comp, ddpa->uncomp, tx);
2178
2179 delta = ddpa->originusedsnap -
2180 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2181 ASSERT3S(delta, <=, 0);
2182 ASSERT3U(ddpa->used, >=, -delta);
2183 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx);
2184 dsl_dir_diduse_space(odd, DD_USED_HEAD,
2185 -ddpa->used - delta, -ddpa->comp, -ddpa->uncomp, tx);
2186
2187 origin_ds->ds_phys->ds_unique_bytes = ddpa->unique;
2188
2189 /* log history record */
2190 spa_history_log_internal_ds(hds, "promote", tx, "");
2191
2192 dsl_dir_rele(odd, FTAG);
2193 promote_rele(ddpa, FTAG);
2194 }
2195
2196 /*
2197 * Make a list of dsl_dataset_t's for the snapshots between first_obj
2198 * (exclusive) and last_obj (inclusive). The list will be in reverse
2199 * order (last_obj will be the list_head()). If first_obj == 0, do all
2200 * snapshots back to this dataset's origin.
2201 */
2202 static int
2203 snaplist_make(dsl_pool_t *dp,
2204 uint64_t first_obj, uint64_t last_obj, list_t *l, void *tag)
2205 {
2206 uint64_t obj = last_obj;
2207
2208 list_create(l, sizeof (struct promotenode),
2209 offsetof(struct promotenode, link));
2210
2211 while (obj != first_obj) {
2212 dsl_dataset_t *ds;
2213 struct promotenode *snap;
2214 int err;
2215
2216 err = dsl_dataset_hold_obj(dp, obj, tag, &ds);
2217 ASSERT(err != ENOENT);
2218 if (err != 0)
2219 return (err);
2220
2221 if (first_obj == 0)
2222 first_obj = ds->ds_dir->dd_phys->dd_origin_obj;
2223
2224 snap = kmem_alloc(sizeof (*snap), KM_PUSHPAGE);
2225 snap->ds = ds;
2226 list_insert_tail(l, snap);
2227 obj = ds->ds_phys->ds_prev_snap_obj;
2228 }
2229
2230 return (0);
2231 }
2232
2233 static int
2234 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep)
2235 {
2236 struct promotenode *snap;
2237
2238 *spacep = 0;
2239 for (snap = list_head(l); snap; snap = list_next(l, snap)) {
2240 uint64_t used, comp, uncomp;
2241 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2242 mintxg, UINT64_MAX, &used, &comp, &uncomp);
2243 *spacep += used;
2244 }
2245 return (0);
2246 }
2247
2248 static void
2249 snaplist_destroy(list_t *l, void *tag)
2250 {
2251 struct promotenode *snap;
2252
2253 if (l == NULL || !list_link_active(&l->list_head))
2254 return;
2255
2256 while ((snap = list_tail(l)) != NULL) {
2257 list_remove(l, snap);
2258 dsl_dataset_rele(snap->ds, tag);
2259 kmem_free(snap, sizeof (*snap));
2260 }
2261 list_destroy(l);
2262 }
2263
2264 static int
2265 promote_hold(dsl_dataset_promote_arg_t *ddpa, dsl_pool_t *dp, void *tag)
2266 {
2267 int error;
2268 dsl_dir_t *dd;
2269 struct promotenode *snap;
2270
2271 error = dsl_dataset_hold(dp, ddpa->ddpa_clonename, tag,
2272 &ddpa->ddpa_clone);
2273 if (error != 0)
2274 return (error);
2275 dd = ddpa->ddpa_clone->ds_dir;
2276
2277 if (dsl_dataset_is_snapshot(ddpa->ddpa_clone) ||
2278 !dsl_dir_is_clone(dd)) {
2279 dsl_dataset_rele(ddpa->ddpa_clone, tag);
2280 return (SET_ERROR(EINVAL));
2281 }
2282
2283 error = snaplist_make(dp, 0, dd->dd_phys->dd_origin_obj,
2284 &ddpa->shared_snaps, tag);
2285 if (error != 0)
2286 goto out;
2287
2288 error = snaplist_make(dp, 0, ddpa->ddpa_clone->ds_object,
2289 &ddpa->clone_snaps, tag);
2290 if (error != 0)
2291 goto out;
2292
2293 snap = list_head(&ddpa->shared_snaps);
2294 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj);
2295 error = snaplist_make(dp, dd->dd_phys->dd_origin_obj,
2296 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj,
2297 &ddpa->origin_snaps, tag);
2298 if (error != 0)
2299 goto out;
2300
2301 if (snap->ds->ds_dir->dd_phys->dd_origin_obj != 0) {
2302 error = dsl_dataset_hold_obj(dp,
2303 snap->ds->ds_dir->dd_phys->dd_origin_obj,
2304 tag, &ddpa->origin_origin);
2305 if (error != 0)
2306 goto out;
2307 }
2308 out:
2309 if (error != 0)
2310 promote_rele(ddpa, tag);
2311 return (error);
2312 }
2313
2314 static void
2315 promote_rele(dsl_dataset_promote_arg_t *ddpa, void *tag)
2316 {
2317 snaplist_destroy(&ddpa->shared_snaps, tag);
2318 snaplist_destroy(&ddpa->clone_snaps, tag);
2319 snaplist_destroy(&ddpa->origin_snaps, tag);
2320 if (ddpa->origin_origin != NULL)
2321 dsl_dataset_rele(ddpa->origin_origin, tag);
2322 dsl_dataset_rele(ddpa->ddpa_clone, tag);
2323 }
2324
2325 /*
2326 * Promote a clone.
2327 *
2328 * If it fails due to a conflicting snapshot name, "conflsnap" will be filled
2329 * in with the name. (It must be at least MAXNAMELEN bytes long.)
2330 */
2331 int
2332 dsl_dataset_promote(const char *name, char *conflsnap)
2333 {
2334 dsl_dataset_promote_arg_t ddpa = { 0 };
2335 uint64_t numsnaps;
2336 int error;
2337 objset_t *os;
2338
2339 /*
2340 * We will modify space proportional to the number of
2341 * snapshots. Compute numsnaps.
2342 */
2343 error = dmu_objset_hold(name, FTAG, &os);
2344 if (error != 0)
2345 return (error);
2346 error = zap_count(dmu_objset_pool(os)->dp_meta_objset,
2347 dmu_objset_ds(os)->ds_phys->ds_snapnames_zapobj, &numsnaps);
2348 dmu_objset_rele(os, FTAG);
2349 if (error != 0)
2350 return (error);
2351
2352 ddpa.ddpa_clonename = name;
2353 ddpa.err_ds = conflsnap;
2354
2355 return (dsl_sync_task(name, dsl_dataset_promote_check,
2356 dsl_dataset_promote_sync, &ddpa, 2 + numsnaps));
2357 }
2358
2359 int
2360 dsl_dataset_clone_swap_check_impl(dsl_dataset_t *clone,
2361 dsl_dataset_t *origin_head, boolean_t force, void *owner, dmu_tx_t *tx)
2362 {
2363 int64_t unused_refres_delta;
2364
2365 /* they should both be heads */
2366 if (dsl_dataset_is_snapshot(clone) ||
2367 dsl_dataset_is_snapshot(origin_head))
2368 return (SET_ERROR(EINVAL));
2369
2370 /* if we are not forcing, the branch point should be just before them */
2371 if (!force && clone->ds_prev != origin_head->ds_prev)
2372 return (SET_ERROR(EINVAL));
2373
2374 /* clone should be the clone (unless they are unrelated) */
2375 if (clone->ds_prev != NULL &&
2376 clone->ds_prev != clone->ds_dir->dd_pool->dp_origin_snap &&
2377 origin_head->ds_dir != clone->ds_prev->ds_dir)
2378 return (SET_ERROR(EINVAL));
2379
2380 /* the clone should be a child of the origin */
2381 if (clone->ds_dir->dd_parent != origin_head->ds_dir)
2382 return (SET_ERROR(EINVAL));
2383
2384 /* origin_head shouldn't be modified unless 'force' */
2385 if (!force &&
2386 dsl_dataset_modified_since_snap(origin_head, origin_head->ds_prev))
2387 return (SET_ERROR(ETXTBSY));
2388
2389 /* origin_head should have no long holds (e.g. is not mounted) */
2390 if (dsl_dataset_handoff_check(origin_head, owner, tx))
2391 return (SET_ERROR(EBUSY));
2392
2393 /* check amount of any unconsumed refreservation */
2394 unused_refres_delta =
2395 (int64_t)MIN(origin_head->ds_reserved,
2396 origin_head->ds_phys->ds_unique_bytes) -
2397 (int64_t)MIN(origin_head->ds_reserved,
2398 clone->ds_phys->ds_unique_bytes);
2399
2400 if (unused_refres_delta > 0 &&
2401 unused_refres_delta >
2402 dsl_dir_space_available(origin_head->ds_dir, NULL, 0, TRUE))
2403 return (SET_ERROR(ENOSPC));
2404
2405 /* clone can't be over the head's refquota */
2406 if (origin_head->ds_quota != 0 &&
2407 clone->ds_phys->ds_referenced_bytes > origin_head->ds_quota)
2408 return (SET_ERROR(EDQUOT));
2409
2410 return (0);
2411 }
2412
2413 void
2414 dsl_dataset_clone_swap_sync_impl(dsl_dataset_t *clone,
2415 dsl_dataset_t *origin_head, dmu_tx_t *tx)
2416 {
2417 dsl_pool_t *dp = dmu_tx_pool(tx);
2418 int64_t unused_refres_delta;
2419
2420 ASSERT(clone->ds_reserved == 0);
2421 ASSERT(origin_head->ds_quota == 0 ||
2422 clone->ds_phys->ds_unique_bytes <= origin_head->ds_quota);
2423 ASSERT3P(clone->ds_prev, ==, origin_head->ds_prev);
2424
2425 dmu_buf_will_dirty(clone->ds_dbuf, tx);
2426 dmu_buf_will_dirty(origin_head->ds_dbuf, tx);
2427
2428 if (clone->ds_objset != NULL) {
2429 dmu_objset_evict(clone->ds_objset);
2430 clone->ds_objset = NULL;
2431 }
2432
2433 if (origin_head->ds_objset != NULL) {
2434 dmu_objset_evict(origin_head->ds_objset);
2435 origin_head->ds_objset = NULL;
2436 }
2437
2438 unused_refres_delta =
2439 (int64_t)MIN(origin_head->ds_reserved,
2440 origin_head->ds_phys->ds_unique_bytes) -
2441 (int64_t)MIN(origin_head->ds_reserved,
2442 clone->ds_phys->ds_unique_bytes);
2443
2444 /*
2445 * Reset origin's unique bytes, if it exists.
2446 */
2447 if (clone->ds_prev) {
2448 dsl_dataset_t *origin = clone->ds_prev;
2449 uint64_t comp, uncomp;
2450
2451 dmu_buf_will_dirty(origin->ds_dbuf, tx);
2452 dsl_deadlist_space_range(&clone->ds_deadlist,
2453 origin->ds_phys->ds_prev_snap_txg, UINT64_MAX,
2454 &origin->ds_phys->ds_unique_bytes, &comp, &uncomp);
2455 }
2456
2457 /* swap blkptrs */
2458 {
2459 blkptr_t tmp;
2460 tmp = origin_head->ds_phys->ds_bp;
2461 origin_head->ds_phys->ds_bp = clone->ds_phys->ds_bp;
2462 clone->ds_phys->ds_bp = tmp;
2463 }
2464
2465 /* set dd_*_bytes */
2466 {
2467 int64_t dused, dcomp, duncomp;
2468 uint64_t cdl_used, cdl_comp, cdl_uncomp;
2469 uint64_t odl_used, odl_comp, odl_uncomp;
2470
2471 ASSERT3U(clone->ds_dir->dd_phys->
2472 dd_used_breakdown[DD_USED_SNAP], ==, 0);
2473
2474 dsl_deadlist_space(&clone->ds_deadlist,
2475 &cdl_used, &cdl_comp, &cdl_uncomp);
2476 dsl_deadlist_space(&origin_head->ds_deadlist,
2477 &odl_used, &odl_comp, &odl_uncomp);
2478
2479 dused = clone->ds_phys->ds_referenced_bytes + cdl_used -
2480 (origin_head->ds_phys->ds_referenced_bytes + odl_used);
2481 dcomp = clone->ds_phys->ds_compressed_bytes + cdl_comp -
2482 (origin_head->ds_phys->ds_compressed_bytes + odl_comp);
2483 duncomp = clone->ds_phys->ds_uncompressed_bytes +
2484 cdl_uncomp -
2485 (origin_head->ds_phys->ds_uncompressed_bytes + odl_uncomp);
2486
2487 dsl_dir_diduse_space(origin_head->ds_dir, DD_USED_HEAD,
2488 dused, dcomp, duncomp, tx);
2489 dsl_dir_diduse_space(clone->ds_dir, DD_USED_HEAD,
2490 -dused, -dcomp, -duncomp, tx);
2491
2492 /*
2493 * The difference in the space used by snapshots is the
2494 * difference in snapshot space due to the head's
2495 * deadlist (since that's the only thing that's
2496 * changing that affects the snapused).
2497 */
2498 dsl_deadlist_space_range(&clone->ds_deadlist,
2499 origin_head->ds_dir->dd_origin_txg, UINT64_MAX,
2500 &cdl_used, &cdl_comp, &cdl_uncomp);
2501 dsl_deadlist_space_range(&origin_head->ds_deadlist,
2502 origin_head->ds_dir->dd_origin_txg, UINT64_MAX,
2503 &odl_used, &odl_comp, &odl_uncomp);
2504 dsl_dir_transfer_space(origin_head->ds_dir, cdl_used - odl_used,
2505 DD_USED_HEAD, DD_USED_SNAP, tx);
2506 }
2507
2508 /* swap ds_*_bytes */
2509 SWITCH64(origin_head->ds_phys->ds_referenced_bytes,
2510 clone->ds_phys->ds_referenced_bytes);
2511 SWITCH64(origin_head->ds_phys->ds_compressed_bytes,
2512 clone->ds_phys->ds_compressed_bytes);
2513 SWITCH64(origin_head->ds_phys->ds_uncompressed_bytes,
2514 clone->ds_phys->ds_uncompressed_bytes);
2515 SWITCH64(origin_head->ds_phys->ds_unique_bytes,
2516 clone->ds_phys->ds_unique_bytes);
2517
2518 /* apply any parent delta for change in unconsumed refreservation */
2519 dsl_dir_diduse_space(origin_head->ds_dir, DD_USED_REFRSRV,
2520 unused_refres_delta, 0, 0, tx);
2521
2522 /*
2523 * Swap deadlists.
2524 */
2525 dsl_deadlist_close(&clone->ds_deadlist);
2526 dsl_deadlist_close(&origin_head->ds_deadlist);
2527 SWITCH64(origin_head->ds_phys->ds_deadlist_obj,
2528 clone->ds_phys->ds_deadlist_obj);
2529 dsl_deadlist_open(&clone->ds_deadlist, dp->dp_meta_objset,
2530 clone->ds_phys->ds_deadlist_obj);
2531 dsl_deadlist_open(&origin_head->ds_deadlist, dp->dp_meta_objset,
2532 origin_head->ds_phys->ds_deadlist_obj);
2533
2534 dsl_scan_ds_clone_swapped(origin_head, clone, tx);
2535
2536 spa_history_log_internal_ds(clone, "clone swap", tx,
2537 "parent=%s", origin_head->ds_dir->dd_myname);
2538 }
2539
2540 /*
2541 * Given a pool name and a dataset object number in that pool,
2542 * return the name of that dataset.
2543 */
2544 int
2545 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf)
2546 {
2547 dsl_pool_t *dp;
2548 dsl_dataset_t *ds;
2549 int error;
2550
2551 error = dsl_pool_hold(pname, FTAG, &dp);
2552 if (error != 0)
2553 return (error);
2554
2555 error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds);
2556 if (error == 0) {
2557 dsl_dataset_name(ds, buf);
2558 dsl_dataset_rele(ds, FTAG);
2559 }
2560 dsl_pool_rele(dp, FTAG);
2561
2562 return (error);
2563 }
2564
2565 int
2566 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota,
2567 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv)
2568 {
2569 int error = 0;
2570
2571 ASSERT3S(asize, >, 0);
2572
2573 /*
2574 * *ref_rsrv is the portion of asize that will come from any
2575 * unconsumed refreservation space.
2576 */
2577 *ref_rsrv = 0;
2578
2579 mutex_enter(&ds->ds_lock);
2580 /*
2581 * Make a space adjustment for reserved bytes.
2582 */
2583 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) {
2584 ASSERT3U(*used, >=,
2585 ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
2586 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
2587 *ref_rsrv =
2588 asize - MIN(asize, parent_delta(ds, asize + inflight));
2589 }
2590
2591 if (!check_quota || ds->ds_quota == 0) {
2592 mutex_exit(&ds->ds_lock);
2593 return (0);
2594 }
2595 /*
2596 * If they are requesting more space, and our current estimate
2597 * is over quota, they get to try again unless the actual
2598 * on-disk is over quota and there are no pending changes (which
2599 * may free up space for us).
2600 */
2601 if (ds->ds_phys->ds_referenced_bytes + inflight >= ds->ds_quota) {
2602 if (inflight > 0 ||
2603 ds->ds_phys->ds_referenced_bytes < ds->ds_quota)
2604 error = SET_ERROR(ERESTART);
2605 else
2606 error = SET_ERROR(EDQUOT);
2607 }
2608 mutex_exit(&ds->ds_lock);
2609
2610 return (error);
2611 }
2612
2613 typedef struct dsl_dataset_set_qr_arg {
2614 const char *ddsqra_name;
2615 zprop_source_t ddsqra_source;
2616 uint64_t ddsqra_value;
2617 } dsl_dataset_set_qr_arg_t;
2618
2619
2620 /* ARGSUSED */
2621 static int
2622 dsl_dataset_set_refquota_check(void *arg, dmu_tx_t *tx)
2623 {
2624 dsl_dataset_set_qr_arg_t *ddsqra = arg;
2625 dsl_pool_t *dp = dmu_tx_pool(tx);
2626 dsl_dataset_t *ds;
2627 int error;
2628 uint64_t newval;
2629
2630 if (spa_version(dp->dp_spa) < SPA_VERSION_REFQUOTA)
2631 return (SET_ERROR(ENOTSUP));
2632
2633 error = dsl_dataset_hold(dp, ddsqra->ddsqra_name, FTAG, &ds);
2634 if (error != 0)
2635 return (error);
2636
2637 if (dsl_dataset_is_snapshot(ds)) {
2638 dsl_dataset_rele(ds, FTAG);
2639 return (SET_ERROR(EINVAL));
2640 }
2641
2642 error = dsl_prop_predict(ds->ds_dir,
2643 zfs_prop_to_name(ZFS_PROP_REFQUOTA),
2644 ddsqra->ddsqra_source, ddsqra->ddsqra_value, &newval);
2645 if (error != 0) {
2646 dsl_dataset_rele(ds, FTAG);
2647 return (error);
2648 }
2649
2650 if (newval == 0) {
2651 dsl_dataset_rele(ds, FTAG);
2652 return (0);
2653 }
2654
2655 if (newval < ds->ds_phys->ds_referenced_bytes ||
2656 newval < ds->ds_reserved) {
2657 dsl_dataset_rele(ds, FTAG);
2658 return (SET_ERROR(ENOSPC));
2659 }
2660
2661 dsl_dataset_rele(ds, FTAG);
2662 return (0);
2663 }
2664
2665 static void
2666 dsl_dataset_set_refquota_sync(void *arg, dmu_tx_t *tx)
2667 {
2668 dsl_dataset_set_qr_arg_t *ddsqra = arg;
2669 dsl_pool_t *dp = dmu_tx_pool(tx);
2670 dsl_dataset_t *ds;
2671 uint64_t newval;
2672
2673 VERIFY0(dsl_dataset_hold(dp, ddsqra->ddsqra_name, FTAG, &ds));
2674
2675 dsl_prop_set_sync_impl(ds,
2676 zfs_prop_to_name(ZFS_PROP_REFQUOTA),
2677 ddsqra->ddsqra_source, sizeof (ddsqra->ddsqra_value), 1,
2678 &ddsqra->ddsqra_value, tx);
2679
2680 VERIFY0(dsl_prop_get_int_ds(ds,
2681 zfs_prop_to_name(ZFS_PROP_REFQUOTA), &newval));
2682
2683 if (ds->ds_quota != newval) {
2684 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2685 ds->ds_quota = newval;
2686 }
2687 dsl_dataset_rele(ds, FTAG);
2688 }
2689
2690 int
2691 dsl_dataset_set_refquota(const char *dsname, zprop_source_t source,
2692 uint64_t refquota)
2693 {
2694 dsl_dataset_set_qr_arg_t ddsqra;
2695
2696 ddsqra.ddsqra_name = dsname;
2697 ddsqra.ddsqra_source = source;
2698 ddsqra.ddsqra_value = refquota;
2699
2700 return (dsl_sync_task(dsname, dsl_dataset_set_refquota_check,
2701 dsl_dataset_set_refquota_sync, &ddsqra, 0));
2702 }
2703
2704 static int
2705 dsl_dataset_set_refreservation_check(void *arg, dmu_tx_t *tx)
2706 {
2707 dsl_dataset_set_qr_arg_t *ddsqra = arg;
2708 dsl_pool_t *dp = dmu_tx_pool(tx);
2709 dsl_dataset_t *ds;
2710 int error;
2711 uint64_t newval, unique;
2712
2713 if (spa_version(dp->dp_spa) < SPA_VERSION_REFRESERVATION)
2714 return (SET_ERROR(ENOTSUP));
2715
2716 error = dsl_dataset_hold(dp, ddsqra->ddsqra_name, FTAG, &ds);
2717 if (error != 0)
2718 return (error);
2719
2720 if (dsl_dataset_is_snapshot(ds)) {
2721 dsl_dataset_rele(ds, FTAG);
2722 return (SET_ERROR(EINVAL));
2723 }
2724
2725 error = dsl_prop_predict(ds->ds_dir,
2726 zfs_prop_to_name(ZFS_PROP_REFRESERVATION),
2727 ddsqra->ddsqra_source, ddsqra->ddsqra_value, &newval);
2728 if (error != 0) {
2729 dsl_dataset_rele(ds, FTAG);
2730 return (error);
2731 }
2732
2733 /*
2734 * If we are doing the preliminary check in open context, the
2735 * space estimates may be inaccurate.
2736 */
2737 if (!dmu_tx_is_syncing(tx)) {
2738 dsl_dataset_rele(ds, FTAG);
2739 return (0);
2740 }
2741
2742 mutex_enter(&ds->ds_lock);
2743 if (!DS_UNIQUE_IS_ACCURATE(ds))
2744 dsl_dataset_recalc_head_uniq(ds);
2745 unique = ds->ds_phys->ds_unique_bytes;
2746 mutex_exit(&ds->ds_lock);
2747
2748 if (MAX(unique, newval) > MAX(unique, ds->ds_reserved)) {
2749 uint64_t delta = MAX(unique, newval) -
2750 MAX(unique, ds->ds_reserved);
2751
2752 if (delta >
2753 dsl_dir_space_available(ds->ds_dir, NULL, 0, B_TRUE) ||
2754 (ds->ds_quota > 0 && newval > ds->ds_quota)) {
2755 dsl_dataset_rele(ds, FTAG);
2756 return (SET_ERROR(ENOSPC));
2757 }
2758 }
2759
2760 dsl_dataset_rele(ds, FTAG);
2761 return (0);
2762 }
2763
2764 void
2765 dsl_dataset_set_refreservation_sync_impl(dsl_dataset_t *ds,
2766 zprop_source_t source, uint64_t value, dmu_tx_t *tx)
2767 {
2768 uint64_t newval;
2769 uint64_t unique;
2770 int64_t delta;
2771
2772 dsl_prop_set_sync_impl(ds, zfs_prop_to_name(ZFS_PROP_REFRESERVATION),
2773 source, sizeof (value), 1, &value, tx);
2774
2775 VERIFY0(dsl_prop_get_int_ds(ds,
2776 zfs_prop_to_name(ZFS_PROP_REFRESERVATION), &newval));
2777
2778 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2779 mutex_enter(&ds->ds_dir->dd_lock);
2780 mutex_enter(&ds->ds_lock);
2781 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
2782 unique = ds->ds_phys->ds_unique_bytes;
2783 delta = MAX(0, (int64_t)(newval - unique)) -
2784 MAX(0, (int64_t)(ds->ds_reserved - unique));
2785 ds->ds_reserved = newval;
2786 mutex_exit(&ds->ds_lock);
2787
2788 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx);
2789 mutex_exit(&ds->ds_dir->dd_lock);
2790 }
2791
2792 static void
2793 dsl_dataset_set_refreservation_sync(void *arg, dmu_tx_t *tx)
2794 {
2795 dsl_dataset_set_qr_arg_t *ddsqra = arg;
2796 dsl_pool_t *dp = dmu_tx_pool(tx);
2797 dsl_dataset_t *ds;
2798
2799 VERIFY0(dsl_dataset_hold(dp, ddsqra->ddsqra_name, FTAG, &ds));
2800 dsl_dataset_set_refreservation_sync_impl(ds,
2801 ddsqra->ddsqra_source, ddsqra->ddsqra_value, tx);
2802 dsl_dataset_rele(ds, FTAG);
2803 }
2804
2805 int
2806 dsl_dataset_set_refreservation(const char *dsname, zprop_source_t source,
2807 uint64_t refreservation)
2808 {
2809 dsl_dataset_set_qr_arg_t ddsqra;
2810
2811 ddsqra.ddsqra_name = dsname;
2812 ddsqra.ddsqra_source = source;
2813 ddsqra.ddsqra_value = refreservation;
2814
2815 return (dsl_sync_task(dsname, dsl_dataset_set_refreservation_check,
2816 dsl_dataset_set_refreservation_sync, &ddsqra, 0));
2817 }
2818
2819 /*
2820 * Return (in *usedp) the amount of space written in new that is not
2821 * present in oldsnap. New may be a snapshot or the head. Old must be
2822 * a snapshot before new, in new's filesystem (or its origin). If not then
2823 * fail and return EINVAL.
2824 *
2825 * The written space is calculated by considering two components: First, we
2826 * ignore any freed space, and calculate the written as new's used space
2827 * minus old's used space. Next, we add in the amount of space that was freed
2828 * between the two snapshots, thus reducing new's used space relative to old's.
2829 * Specifically, this is the space that was born before old->ds_creation_txg,
2830 * and freed before new (ie. on new's deadlist or a previous deadlist).
2831 *
2832 * space freed [---------------------]
2833 * snapshots ---O-------O--------O-------O------
2834 * oldsnap new
2835 */
2836 int
2837 dsl_dataset_space_written(dsl_dataset_t *oldsnap, dsl_dataset_t *new,
2838 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
2839 {
2840 int err = 0;
2841 uint64_t snapobj;
2842 dsl_pool_t *dp = new->ds_dir->dd_pool;
2843
2844 ASSERT(dsl_pool_config_held(dp));
2845
2846 *usedp = 0;
2847 *usedp += new->ds_phys->ds_referenced_bytes;
2848 *usedp -= oldsnap->ds_phys->ds_referenced_bytes;
2849
2850 *compp = 0;
2851 *compp += new->ds_phys->ds_compressed_bytes;
2852 *compp -= oldsnap->ds_phys->ds_compressed_bytes;
2853
2854 *uncompp = 0;
2855 *uncompp += new->ds_phys->ds_uncompressed_bytes;
2856 *uncompp -= oldsnap->ds_phys->ds_uncompressed_bytes;
2857
2858 snapobj = new->ds_object;
2859 while (snapobj != oldsnap->ds_object) {
2860 dsl_dataset_t *snap;
2861 uint64_t used, comp, uncomp;
2862
2863 if (snapobj == new->ds_object) {
2864 snap = new;
2865 } else {
2866 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &snap);
2867 if (err != 0)
2868 break;
2869 }
2870
2871 if (snap->ds_phys->ds_prev_snap_txg ==
2872 oldsnap->ds_phys->ds_creation_txg) {
2873 /*
2874 * The blocks in the deadlist can not be born after
2875 * ds_prev_snap_txg, so get the whole deadlist space,
2876 * which is more efficient (especially for old-format
2877 * deadlists). Unfortunately the deadlist code
2878 * doesn't have enough information to make this
2879 * optimization itself.
2880 */
2881 dsl_deadlist_space(&snap->ds_deadlist,
2882 &used, &comp, &uncomp);
2883 } else {
2884 dsl_deadlist_space_range(&snap->ds_deadlist,
2885 0, oldsnap->ds_phys->ds_creation_txg,
2886 &used, &comp, &uncomp);
2887 }
2888 *usedp += used;
2889 *compp += comp;
2890 *uncompp += uncomp;
2891
2892 /*
2893 * If we get to the beginning of the chain of snapshots
2894 * (ds_prev_snap_obj == 0) before oldsnap, then oldsnap
2895 * was not a snapshot of/before new.
2896 */
2897 snapobj = snap->ds_phys->ds_prev_snap_obj;
2898 if (snap != new)
2899 dsl_dataset_rele(snap, FTAG);
2900 if (snapobj == 0) {
2901 err = SET_ERROR(EINVAL);
2902 break;
2903 }
2904
2905 }
2906 return (err);
2907 }
2908
2909 /*
2910 * Return (in *usedp) the amount of space that will be reclaimed if firstsnap,
2911 * lastsnap, and all snapshots in between are deleted.
2912 *
2913 * blocks that would be freed [---------------------------]
2914 * snapshots ---O-------O--------O-------O--------O
2915 * firstsnap lastsnap
2916 *
2917 * This is the set of blocks that were born after the snap before firstsnap,
2918 * (birth > firstsnap->prev_snap_txg) and died before the snap after the
2919 * last snap (ie, is on lastsnap->ds_next->ds_deadlist or an earlier deadlist).
2920 * We calculate this by iterating over the relevant deadlists (from the snap
2921 * after lastsnap, backward to the snap after firstsnap), summing up the
2922 * space on the deadlist that was born after the snap before firstsnap.
2923 */
2924 int
2925 dsl_dataset_space_wouldfree(dsl_dataset_t *firstsnap,
2926 dsl_dataset_t *lastsnap,
2927 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
2928 {
2929 int err = 0;
2930 uint64_t snapobj;
2931 dsl_pool_t *dp = firstsnap->ds_dir->dd_pool;
2932
2933 ASSERT(dsl_dataset_is_snapshot(firstsnap));
2934 ASSERT(dsl_dataset_is_snapshot(lastsnap));
2935
2936 /*
2937 * Check that the snapshots are in the same dsl_dir, and firstsnap
2938 * is before lastsnap.
2939 */
2940 if (firstsnap->ds_dir != lastsnap->ds_dir ||
2941 firstsnap->ds_phys->ds_creation_txg >
2942 lastsnap->ds_phys->ds_creation_txg)
2943 return (SET_ERROR(EINVAL));
2944
2945 *usedp = *compp = *uncompp = 0;
2946
2947 snapobj = lastsnap->ds_phys->ds_next_snap_obj;
2948 while (snapobj != firstsnap->ds_object) {
2949 dsl_dataset_t *ds;
2950 uint64_t used, comp, uncomp;
2951
2952 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &ds);
2953 if (err != 0)
2954 break;
2955
2956 dsl_deadlist_space_range(&ds->ds_deadlist,
2957 firstsnap->ds_phys->ds_prev_snap_txg, UINT64_MAX,
2958 &used, &comp, &uncomp);
2959 *usedp += used;
2960 *compp += comp;
2961 *uncompp += uncomp;
2962
2963 snapobj = ds->ds_phys->ds_prev_snap_obj;
2964 ASSERT3U(snapobj, !=, 0);
2965 dsl_dataset_rele(ds, FTAG);
2966 }
2967 return (err);
2968 }
2969
2970 /*
2971 * Return TRUE if 'earlier' is an earlier snapshot in 'later's timeline.
2972 * For example, they could both be snapshots of the same filesystem, and
2973 * 'earlier' is before 'later'. Or 'earlier' could be the origin of
2974 * 'later's filesystem. Or 'earlier' could be an older snapshot in the origin's
2975 * filesystem. Or 'earlier' could be the origin's origin.
2976 */
2977 boolean_t
2978 dsl_dataset_is_before(dsl_dataset_t *later, dsl_dataset_t *earlier)
2979 {
2980 dsl_pool_t *dp = later->ds_dir->dd_pool;
2981 int error;
2982 boolean_t ret;
2983 dsl_dataset_t *origin;
2984
2985 ASSERT(dsl_pool_config_held(dp));
2986
2987 if (earlier->ds_phys->ds_creation_txg >=
2988 later->ds_phys->ds_creation_txg)
2989 return (B_FALSE);
2990
2991 if (later->ds_dir == earlier->ds_dir)
2992 return (B_TRUE);
2993 if (!dsl_dir_is_clone(later->ds_dir))
2994 return (B_FALSE);
2995
2996 if (later->ds_dir->dd_phys->dd_origin_obj == earlier->ds_object)
2997 return (B_TRUE);
2998 error = dsl_dataset_hold_obj(dp,
2999 later->ds_dir->dd_phys->dd_origin_obj, FTAG, &origin);
3000 if (error != 0)
3001 return (B_FALSE);
3002 ret = dsl_dataset_is_before(origin, earlier);
3003 dsl_dataset_rele(origin, FTAG);
3004 return (ret);
3005 }
3006
3007 #if defined(_KERNEL) && defined(HAVE_SPL)
3008 EXPORT_SYMBOL(dsl_dataset_hold);
3009 EXPORT_SYMBOL(dsl_dataset_hold_obj);
3010 EXPORT_SYMBOL(dsl_dataset_own);
3011 EXPORT_SYMBOL(dsl_dataset_own_obj);
3012 EXPORT_SYMBOL(dsl_dataset_name);
3013 EXPORT_SYMBOL(dsl_dataset_rele);
3014 EXPORT_SYMBOL(dsl_dataset_disown);
3015 EXPORT_SYMBOL(dsl_dataset_tryown);
3016 EXPORT_SYMBOL(dsl_dataset_create_sync);
3017 EXPORT_SYMBOL(dsl_dataset_create_sync_dd);
3018 EXPORT_SYMBOL(dsl_dataset_snapshot_check);
3019 EXPORT_SYMBOL(dsl_dataset_snapshot_sync);
3020 EXPORT_SYMBOL(dsl_dataset_promote);
3021 EXPORT_SYMBOL(dsl_dataset_user_hold);
3022 EXPORT_SYMBOL(dsl_dataset_user_release);
3023 EXPORT_SYMBOL(dsl_dataset_get_holds);
3024 EXPORT_SYMBOL(dsl_dataset_get_blkptr);
3025 EXPORT_SYMBOL(dsl_dataset_set_blkptr);
3026 EXPORT_SYMBOL(dsl_dataset_get_spa);
3027 EXPORT_SYMBOL(dsl_dataset_modified_since_snap);
3028 EXPORT_SYMBOL(dsl_dataset_space_written);
3029 EXPORT_SYMBOL(dsl_dataset_space_wouldfree);
3030 EXPORT_SYMBOL(dsl_dataset_sync);
3031 EXPORT_SYMBOL(dsl_dataset_block_born);
3032 EXPORT_SYMBOL(dsl_dataset_block_kill);
3033 EXPORT_SYMBOL(dsl_dataset_block_freeable);
3034 EXPORT_SYMBOL(dsl_dataset_prev_snap_txg);
3035 EXPORT_SYMBOL(dsl_dataset_dirty);
3036 EXPORT_SYMBOL(dsl_dataset_stats);
3037 EXPORT_SYMBOL(dsl_dataset_fast_stat);
3038 EXPORT_SYMBOL(dsl_dataset_space);
3039 EXPORT_SYMBOL(dsl_dataset_fsid_guid);
3040 EXPORT_SYMBOL(dsl_dsobj_to_dsname);
3041 EXPORT_SYMBOL(dsl_dataset_check_quota);
3042 EXPORT_SYMBOL(dsl_dataset_clone_swap_check_impl);
3043 EXPORT_SYMBOL(dsl_dataset_clone_swap_sync_impl);
3044 #endif
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