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) 2012 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
49 static char *dsl_reaper = "the grim reaper";
50
51 static dsl_checkfunc_t dsl_dataset_destroy_begin_check;
52 static dsl_syncfunc_t dsl_dataset_destroy_begin_sync;
53 static dsl_syncfunc_t dsl_dataset_set_reservation_sync;
54
55 #define SWITCH64(x, y) \
56 { \
57 uint64_t __tmp = (x); \
58 (x) = (y); \
59 (y) = __tmp; \
60 }
61
62 #define DS_REF_MAX (1ULL << 62)
63
64 #define DSL_DEADLIST_BLOCKSIZE SPA_MAXBLOCKSIZE
65
66 #define DSL_DATASET_IS_DESTROYED(ds) ((ds)->ds_owner == dsl_reaper)
67
68
69 /*
70 * Figure out how much of this delta should be propogated to the dsl_dir
71 * layer. If there's a refreservation, that space has already been
72 * partially accounted for in our ancestors.
73 */
74 static int64_t
75 parent_delta(dsl_dataset_t *ds, int64_t delta)
76 {
77 uint64_t old_bytes, new_bytes;
78
79 if (ds->ds_reserved == 0)
80 return (delta);
81
82 old_bytes = MAX(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
83 new_bytes = MAX(ds->ds_phys->ds_unique_bytes + delta, ds->ds_reserved);
84
85 ASSERT3U(ABS((int64_t)(new_bytes - old_bytes)), <=, ABS(delta));
86 return (new_bytes - old_bytes);
87 }
88
89 void
90 dsl_dataset_block_born(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx)
91 {
92 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
93 int compressed = BP_GET_PSIZE(bp);
94 int uncompressed = BP_GET_UCSIZE(bp);
95 int64_t delta;
96
97 dprintf_bp(bp, "ds=%p", ds);
98
99 ASSERT(dmu_tx_is_syncing(tx));
100 /* It could have been compressed away to nothing */
101 if (BP_IS_HOLE(bp))
102 return;
103 ASSERT(BP_GET_TYPE(bp) != DMU_OT_NONE);
104 ASSERT(DMU_OT_IS_VALID(BP_GET_TYPE(bp)));
105 if (ds == NULL) {
106 dsl_pool_mos_diduse_space(tx->tx_pool,
107 used, compressed, uncompressed);
108 return;
109 }
110 dmu_buf_will_dirty(ds->ds_dbuf, tx);
111
112 mutex_enter(&ds->ds_dir->dd_lock);
113 mutex_enter(&ds->ds_lock);
114 delta = parent_delta(ds, used);
115 ds->ds_phys->ds_referenced_bytes += used;
116 ds->ds_phys->ds_compressed_bytes += compressed;
117 ds->ds_phys->ds_uncompressed_bytes += uncompressed;
118 ds->ds_phys->ds_unique_bytes += used;
119 mutex_exit(&ds->ds_lock);
120 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta,
121 compressed, uncompressed, tx);
122 dsl_dir_transfer_space(ds->ds_dir, used - delta,
123 DD_USED_REFRSRV, DD_USED_HEAD, tx);
124 mutex_exit(&ds->ds_dir->dd_lock);
125 }
126
127 int
128 dsl_dataset_block_kill(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx,
129 boolean_t async)
130 {
131 if (BP_IS_HOLE(bp))
132 return (0);
133
134 ASSERT(dmu_tx_is_syncing(tx));
135 ASSERT(bp->blk_birth <= tx->tx_txg);
136
137 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
138 int compressed = BP_GET_PSIZE(bp);
139 int uncompressed = BP_GET_UCSIZE(bp);
140
141 ASSERT(used > 0);
142 if (ds == NULL) {
143 dsl_free(tx->tx_pool, tx->tx_txg, bp);
144 dsl_pool_mos_diduse_space(tx->tx_pool,
145 -used, -compressed, -uncompressed);
146 return (used);
147 }
148 ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool);
149
150 ASSERT(!dsl_dataset_is_snapshot(ds));
151 dmu_buf_will_dirty(ds->ds_dbuf, tx);
152
153 if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) {
154 int64_t delta;
155
156 dprintf_bp(bp, "freeing ds=%llu", ds->ds_object);
157 dsl_free(tx->tx_pool, tx->tx_txg, bp);
158
159 mutex_enter(&ds->ds_dir->dd_lock);
160 mutex_enter(&ds->ds_lock);
161 ASSERT(ds->ds_phys->ds_unique_bytes >= used ||
162 !DS_UNIQUE_IS_ACCURATE(ds));
163 delta = parent_delta(ds, -used);
164 ds->ds_phys->ds_unique_bytes -= used;
165 mutex_exit(&ds->ds_lock);
166 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
167 delta, -compressed, -uncompressed, tx);
168 dsl_dir_transfer_space(ds->ds_dir, -used - delta,
169 DD_USED_REFRSRV, DD_USED_HEAD, tx);
170 mutex_exit(&ds->ds_dir->dd_lock);
171 } else {
172 dprintf_bp(bp, "putting on dead list: %s", "");
173 if (async) {
174 /*
175 * We are here as part of zio's write done callback,
176 * which means we're a zio interrupt thread. We can't
177 * call dsl_deadlist_insert() now because it may block
178 * waiting for I/O. Instead, put bp on the deferred
179 * queue and let dsl_pool_sync() finish the job.
180 */
181 bplist_append(&ds->ds_pending_deadlist, bp);
182 } else {
183 dsl_deadlist_insert(&ds->ds_deadlist, bp, tx);
184 }
185 ASSERT3U(ds->ds_prev->ds_object, ==,
186 ds->ds_phys->ds_prev_snap_obj);
187 ASSERT(ds->ds_prev->ds_phys->ds_num_children > 0);
188 /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */
189 if (ds->ds_prev->ds_phys->ds_next_snap_obj ==
190 ds->ds_object && bp->blk_birth >
191 ds->ds_prev->ds_phys->ds_prev_snap_txg) {
192 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
193 mutex_enter(&ds->ds_prev->ds_lock);
194 ds->ds_prev->ds_phys->ds_unique_bytes += used;
195 mutex_exit(&ds->ds_prev->ds_lock);
196 }
197 if (bp->blk_birth > ds->ds_dir->dd_origin_txg) {
198 dsl_dir_transfer_space(ds->ds_dir, used,
199 DD_USED_HEAD, DD_USED_SNAP, tx);
200 }
201 }
202 mutex_enter(&ds->ds_lock);
203 ASSERT3U(ds->ds_phys->ds_referenced_bytes, >=, used);
204 ds->ds_phys->ds_referenced_bytes -= used;
205 ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed);
206 ds->ds_phys->ds_compressed_bytes -= compressed;
207 ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed);
208 ds->ds_phys->ds_uncompressed_bytes -= uncompressed;
209 mutex_exit(&ds->ds_lock);
210
211 return (used);
212 }
213
214 uint64_t
215 dsl_dataset_prev_snap_txg(dsl_dataset_t *ds)
216 {
217 uint64_t trysnap = 0;
218
219 if (ds == NULL)
220 return (0);
221 /*
222 * The snapshot creation could fail, but that would cause an
223 * incorrect FALSE return, which would only result in an
224 * overestimation of the amount of space that an operation would
225 * consume, which is OK.
226 *
227 * There's also a small window where we could miss a pending
228 * snapshot, because we could set the sync task in the quiescing
229 * phase. So this should only be used as a guess.
230 */
231 if (ds->ds_trysnap_txg >
232 spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa))
233 trysnap = ds->ds_trysnap_txg;
234 return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap));
235 }
236
237 boolean_t
238 dsl_dataset_block_freeable(dsl_dataset_t *ds, const blkptr_t *bp,
239 uint64_t blk_birth)
240 {
241 if (blk_birth <= dsl_dataset_prev_snap_txg(ds))
242 return (B_FALSE);
243
244 ddt_prefetch(dsl_dataset_get_spa(ds), bp);
245
246 return (B_TRUE);
247 }
248
249 /* ARGSUSED */
250 static void
251 dsl_dataset_evict(dmu_buf_t *db, void *dsv)
252 {
253 dsl_dataset_t *ds = dsv;
254
255 ASSERT(ds->ds_owner == NULL || DSL_DATASET_IS_DESTROYED(ds));
256
257 unique_remove(ds->ds_fsid_guid);
258
259 if (ds->ds_objset != NULL)
260 dmu_objset_evict(ds->ds_objset);
261
262 if (ds->ds_prev) {
263 dsl_dataset_drop_ref(ds->ds_prev, ds);
264 ds->ds_prev = NULL;
265 }
266
267 bplist_destroy(&ds->ds_pending_deadlist);
268 if (db != NULL) {
269 dsl_deadlist_close(&ds->ds_deadlist);
270 } else {
271 ASSERT(ds->ds_deadlist.dl_dbuf == NULL);
272 ASSERT(!ds->ds_deadlist.dl_oldfmt);
273 }
274 if (ds->ds_dir)
275 dsl_dir_close(ds->ds_dir, ds);
276
277 ASSERT(!list_link_active(&ds->ds_synced_link));
278
279 mutex_destroy(&ds->ds_lock);
280 mutex_destroy(&ds->ds_recvlock);
281 mutex_destroy(&ds->ds_opening_lock);
282 rw_destroy(&ds->ds_rwlock);
283 cv_destroy(&ds->ds_exclusive_cv);
284
285 kmem_free(ds, sizeof (dsl_dataset_t));
286 }
287
288 static int
289 dsl_dataset_get_snapname(dsl_dataset_t *ds)
290 {
291 dsl_dataset_phys_t *headphys;
292 int err;
293 dmu_buf_t *headdbuf;
294 dsl_pool_t *dp = ds->ds_dir->dd_pool;
295 objset_t *mos = dp->dp_meta_objset;
296
297 if (ds->ds_snapname[0])
298 return (0);
299 if (ds->ds_phys->ds_next_snap_obj == 0)
300 return (0);
301
302 err = dmu_bonus_hold(mos, ds->ds_dir->dd_phys->dd_head_dataset_obj,
303 FTAG, &headdbuf);
304 if (err)
305 return (err);
306 headphys = headdbuf->db_data;
307 err = zap_value_search(dp->dp_meta_objset,
308 headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname);
309 dmu_buf_rele(headdbuf, FTAG);
310 return (err);
311 }
312
313 static int
314 dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name, uint64_t *value)
315 {
316 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
317 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
318 matchtype_t mt;
319 int err;
320
321 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
322 mt = MT_FIRST;
323 else
324 mt = MT_EXACT;
325
326 err = zap_lookup_norm(mos, snapobj, name, 8, 1,
327 value, mt, NULL, 0, NULL);
328 if (err == ENOTSUP && mt == MT_FIRST)
329 err = zap_lookup(mos, snapobj, name, 8, 1, value);
330 return (err);
331 }
332
333 static int
334 dsl_dataset_snap_remove(dsl_dataset_t *ds, char *name, dmu_tx_t *tx)
335 {
336 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
337 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
338 matchtype_t mt;
339 int err;
340
341 dsl_dir_snap_cmtime_update(ds->ds_dir);
342
343 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
344 mt = MT_FIRST;
345 else
346 mt = MT_EXACT;
347
348 err = zap_remove_norm(mos, snapobj, name, mt, tx);
349 if (err == ENOTSUP && mt == MT_FIRST)
350 err = zap_remove(mos, snapobj, name, tx);
351 return (err);
352 }
353
354 static int
355 dsl_dataset_get_ref(dsl_pool_t *dp, uint64_t dsobj, void *tag,
356 dsl_dataset_t **dsp)
357 {
358 objset_t *mos = dp->dp_meta_objset;
359 dmu_buf_t *dbuf;
360 dsl_dataset_t *ds;
361 int err;
362 dmu_object_info_t doi;
363
364 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) ||
365 dsl_pool_sync_context(dp));
366
367 err = dmu_bonus_hold(mos, dsobj, tag, &dbuf);
368 if (err)
369 return (err);
370
371 /* Make sure dsobj has the correct object type. */
372 dmu_object_info_from_db(dbuf, &doi);
373 if (doi.doi_type != DMU_OT_DSL_DATASET)
374 return (EINVAL);
375
376 ds = dmu_buf_get_user(dbuf);
377 if (ds == NULL) {
378 dsl_dataset_t *winner;
379
380 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP);
381 ds->ds_dbuf = dbuf;
382 ds->ds_object = dsobj;
383 ds->ds_phys = dbuf->db_data;
384
385 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL);
386 mutex_init(&ds->ds_recvlock, NULL, MUTEX_DEFAULT, NULL);
387 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL);
388 mutex_init(&ds->ds_sendstream_lock, NULL, MUTEX_DEFAULT, NULL);
389
390 rw_init(&ds->ds_rwlock, 0, 0, 0);
391 cv_init(&ds->ds_exclusive_cv, NULL, CV_DEFAULT, NULL);
392
393 bplist_create(&ds->ds_pending_deadlist);
394 dsl_deadlist_open(&ds->ds_deadlist,
395 mos, ds->ds_phys->ds_deadlist_obj);
396
397 list_create(&ds->ds_sendstreams, sizeof (dmu_sendarg_t),
398 offsetof(dmu_sendarg_t, dsa_link));
399
400 if (err == 0) {
401 err = dsl_dir_open_obj(dp,
402 ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir);
403 }
404 if (err) {
405 mutex_destroy(&ds->ds_lock);
406 mutex_destroy(&ds->ds_recvlock);
407 mutex_destroy(&ds->ds_opening_lock);
408 rw_destroy(&ds->ds_rwlock);
409 cv_destroy(&ds->ds_exclusive_cv);
410 bplist_destroy(&ds->ds_pending_deadlist);
411 dsl_deadlist_close(&ds->ds_deadlist);
412 kmem_free(ds, sizeof (dsl_dataset_t));
413 dmu_buf_rele(dbuf, tag);
414 return (err);
415 }
416
417 if (!dsl_dataset_is_snapshot(ds)) {
418 ds->ds_snapname[0] = '\0';
419 if (ds->ds_phys->ds_prev_snap_obj) {
420 err = dsl_dataset_get_ref(dp,
421 ds->ds_phys->ds_prev_snap_obj,
422 ds, &ds->ds_prev);
423 }
424 } else {
425 if (zfs_flags & ZFS_DEBUG_SNAPNAMES)
426 err = dsl_dataset_get_snapname(ds);
427 if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) {
428 err = zap_count(
429 ds->ds_dir->dd_pool->dp_meta_objset,
430 ds->ds_phys->ds_userrefs_obj,
431 &ds->ds_userrefs);
432 }
433 }
434
435 if (err == 0 && !dsl_dataset_is_snapshot(ds)) {
436 /*
437 * In sync context, we're called with either no lock
438 * or with the write lock. If we're not syncing,
439 * we're always called with the read lock held.
440 */
441 boolean_t need_lock =
442 !RW_WRITE_HELD(&dp->dp_config_rwlock) &&
443 dsl_pool_sync_context(dp);
444
445 if (need_lock)
446 rw_enter(&dp->dp_config_rwlock, RW_READER);
447
448 err = dsl_prop_get_ds(ds,
449 "refreservation", sizeof (uint64_t), 1,
450 &ds->ds_reserved, NULL);
451 if (err == 0) {
452 err = dsl_prop_get_ds(ds,
453 "refquota", sizeof (uint64_t), 1,
454 &ds->ds_quota, NULL);
455 }
456
457 if (need_lock)
458 rw_exit(&dp->dp_config_rwlock);
459 } else {
460 ds->ds_reserved = ds->ds_quota = 0;
461 }
462
463 if (err == 0) {
464 winner = dmu_buf_set_user_ie(dbuf, ds, &ds->ds_phys,
465 dsl_dataset_evict);
466 }
467 if (err || winner) {
468 bplist_destroy(&ds->ds_pending_deadlist);
469 dsl_deadlist_close(&ds->ds_deadlist);
470 if (ds->ds_prev)
471 dsl_dataset_drop_ref(ds->ds_prev, ds);
472 dsl_dir_close(ds->ds_dir, ds);
473 mutex_destroy(&ds->ds_lock);
474 mutex_destroy(&ds->ds_recvlock);
475 mutex_destroy(&ds->ds_opening_lock);
476 rw_destroy(&ds->ds_rwlock);
477 cv_destroy(&ds->ds_exclusive_cv);
478 kmem_free(ds, sizeof (dsl_dataset_t));
479 if (err) {
480 dmu_buf_rele(dbuf, tag);
481 return (err);
482 }
483 ds = winner;
484 } else {
485 ds->ds_fsid_guid =
486 unique_insert(ds->ds_phys->ds_fsid_guid);
487 }
488 }
489 ASSERT3P(ds->ds_dbuf, ==, dbuf);
490 ASSERT3P(ds->ds_phys, ==, dbuf->db_data);
491 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 ||
492 spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN ||
493 dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap);
494 mutex_enter(&ds->ds_lock);
495 if (!dsl_pool_sync_context(dp) && DSL_DATASET_IS_DESTROYED(ds)) {
496 mutex_exit(&ds->ds_lock);
497 dmu_buf_rele(ds->ds_dbuf, tag);
498 return (ENOENT);
499 }
500 mutex_exit(&ds->ds_lock);
501 *dsp = ds;
502 return (0);
503 }
504
505 static int
506 dsl_dataset_hold_ref(dsl_dataset_t *ds, void *tag)
507 {
508 dsl_pool_t *dp = ds->ds_dir->dd_pool;
509
510 /*
511 * In syncing context we don't want the rwlock lock: there
512 * may be an existing writer waiting for sync phase to
513 * finish. We don't need to worry about such writers, since
514 * sync phase is single-threaded, so the writer can't be
515 * doing anything while we are active.
516 */
517 if (dsl_pool_sync_context(dp)) {
518 ASSERT(!DSL_DATASET_IS_DESTROYED(ds));
519 return (0);
520 }
521
522 /*
523 * Normal users will hold the ds_rwlock as a READER until they
524 * are finished (i.e., call dsl_dataset_rele()). "Owners" will
525 * drop their READER lock after they set the ds_owner field.
526 *
527 * If the dataset is being destroyed, the destroy thread will
528 * obtain a WRITER lock for exclusive access after it's done its
529 * open-context work and then change the ds_owner to
530 * dsl_reaper once destruction is assured. So threads
531 * may block here temporarily, until the "destructability" of
532 * the dataset is determined.
533 */
534 ASSERT(!RW_WRITE_HELD(&dp->dp_config_rwlock));
535 mutex_enter(&ds->ds_lock);
536 while (!rw_tryenter(&ds->ds_rwlock, RW_READER)) {
537 rw_exit(&dp->dp_config_rwlock);
538 cv_wait(&ds->ds_exclusive_cv, &ds->ds_lock);
539 if (DSL_DATASET_IS_DESTROYED(ds)) {
540 mutex_exit(&ds->ds_lock);
541 dsl_dataset_drop_ref(ds, tag);
542 rw_enter(&dp->dp_config_rwlock, RW_READER);
543 return (ENOENT);
544 }
545 /*
546 * The dp_config_rwlock lives above the ds_lock. And
547 * we need to check DSL_DATASET_IS_DESTROYED() while
548 * holding the ds_lock, so we have to drop and reacquire
549 * the ds_lock here.
550 */
551 mutex_exit(&ds->ds_lock);
552 rw_enter(&dp->dp_config_rwlock, RW_READER);
553 mutex_enter(&ds->ds_lock);
554 }
555 mutex_exit(&ds->ds_lock);
556 return (0);
557 }
558
559 int
560 dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag,
561 dsl_dataset_t **dsp)
562 {
563 int err = dsl_dataset_get_ref(dp, dsobj, tag, dsp);
564
565 if (err)
566 return (err);
567 return (dsl_dataset_hold_ref(*dsp, tag));
568 }
569
570 int
571 dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj, boolean_t inconsistentok,
572 void *tag, dsl_dataset_t **dsp)
573 {
574 int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp);
575 if (err)
576 return (err);
577 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) {
578 dsl_dataset_rele(*dsp, tag);
579 *dsp = NULL;
580 return (EBUSY);
581 }
582 return (0);
583 }
584
585 int
586 dsl_dataset_hold(const char *name, void *tag, dsl_dataset_t **dsp)
587 {
588 dsl_dir_t *dd;
589 dsl_pool_t *dp;
590 const char *snapname;
591 uint64_t obj;
592 int err = 0;
593
594 err = dsl_dir_open_spa(NULL, name, FTAG, &dd, &snapname);
595 if (err)
596 return (err);
597
598 dp = dd->dd_pool;
599 obj = dd->dd_phys->dd_head_dataset_obj;
600 rw_enter(&dp->dp_config_rwlock, RW_READER);
601 if (obj)
602 err = dsl_dataset_get_ref(dp, obj, tag, dsp);
603 else
604 err = ENOENT;
605 if (err)
606 goto out;
607
608 err = dsl_dataset_hold_ref(*dsp, tag);
609
610 /* we may be looking for a snapshot */
611 if (err == 0 && snapname != NULL) {
612 dsl_dataset_t *ds = NULL;
613
614 if (*snapname++ != '@') {
615 dsl_dataset_rele(*dsp, tag);
616 err = ENOENT;
617 goto out;
618 }
619
620 dprintf("looking for snapshot '%s'\n", snapname);
621 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj);
622 if (err == 0)
623 err = dsl_dataset_get_ref(dp, obj, tag, &ds);
624 dsl_dataset_rele(*dsp, tag);
625
626 ASSERT3U((err == 0), ==, (ds != NULL));
627
628 if (ds) {
629 mutex_enter(&ds->ds_lock);
630 if (ds->ds_snapname[0] == 0)
631 (void) strlcpy(ds->ds_snapname, snapname,
632 sizeof (ds->ds_snapname));
633 mutex_exit(&ds->ds_lock);
634 err = dsl_dataset_hold_ref(ds, tag);
635 *dsp = err ? NULL : ds;
636 }
637 }
638 out:
639 rw_exit(&dp->dp_config_rwlock);
640 dsl_dir_close(dd, FTAG);
641 return (err);
642 }
643
644 int
645 dsl_dataset_own(const char *name, boolean_t inconsistentok,
646 void *tag, dsl_dataset_t **dsp)
647 {
648 int err = dsl_dataset_hold(name, tag, dsp);
649 if (err)
650 return (err);
651 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) {
652 dsl_dataset_rele(*dsp, tag);
653 return (EBUSY);
654 }
655 return (0);
656 }
657
658 void
659 dsl_dataset_name(dsl_dataset_t *ds, char *name)
660 {
661 if (ds == NULL) {
662 (void) strcpy(name, "mos");
663 } else {
664 dsl_dir_name(ds->ds_dir, name);
665 VERIFY(0 == dsl_dataset_get_snapname(ds));
666 if (ds->ds_snapname[0]) {
667 (void) strcat(name, "@");
668 /*
669 * We use a "recursive" mutex so that we
670 * can call dprintf_ds() with ds_lock held.
671 */
672 if (!MUTEX_HELD(&ds->ds_lock)) {
673 mutex_enter(&ds->ds_lock);
674 (void) strcat(name, ds->ds_snapname);
675 mutex_exit(&ds->ds_lock);
676 } else {
677 (void) strcat(name, ds->ds_snapname);
678 }
679 }
680 }
681 }
682
683 int
684 dsl_dataset_namelen(dsl_dataset_t *ds)
685 {
686 int result;
687
688 if (ds == NULL) {
689 result = 3; /* "mos" */
690 } else {
691 result = dsl_dir_namelen(ds->ds_dir);
692 VERIFY(0 == dsl_dataset_get_snapname(ds));
693 if (ds->ds_snapname[0]) {
694 ++result; /* adding one for the @-sign */
695 if (!MUTEX_HELD(&ds->ds_lock)) {
696 mutex_enter(&ds->ds_lock);
697 result += strlen(ds->ds_snapname);
698 mutex_exit(&ds->ds_lock);
699 } else {
700 result += strlen(ds->ds_snapname);
701 }
702 }
703 }
704
705 return (result);
706 }
707
708 void
709 dsl_dataset_drop_ref(dsl_dataset_t *ds, void *tag)
710 {
711 dmu_buf_rele(ds->ds_dbuf, tag);
712 }
713
714 void
715 dsl_dataset_rele(dsl_dataset_t *ds, void *tag)
716 {
717 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) {
718 rw_exit(&ds->ds_rwlock);
719 }
720 dsl_dataset_drop_ref(ds, tag);
721 }
722
723 void
724 dsl_dataset_disown(dsl_dataset_t *ds, void *tag)
725 {
726 ASSERT((ds->ds_owner == tag && ds->ds_dbuf) ||
727 (DSL_DATASET_IS_DESTROYED(ds) && ds->ds_dbuf == NULL));
728
729 mutex_enter(&ds->ds_lock);
730 ds->ds_owner = NULL;
731 if (RW_WRITE_HELD(&ds->ds_rwlock)) {
732 rw_exit(&ds->ds_rwlock);
733 cv_broadcast(&ds->ds_exclusive_cv);
734 }
735 mutex_exit(&ds->ds_lock);
736 if (ds->ds_dbuf)
737 dsl_dataset_drop_ref(ds, tag);
738 else
739 dsl_dataset_evict(NULL, ds);
740 }
741
742 boolean_t
743 dsl_dataset_tryown(dsl_dataset_t *ds, boolean_t inconsistentok, void *tag)
744 {
745 boolean_t gotit = FALSE;
746
747 mutex_enter(&ds->ds_lock);
748 if (ds->ds_owner == NULL &&
749 (!DS_IS_INCONSISTENT(ds) || inconsistentok)) {
750 ds->ds_owner = tag;
751 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool))
752 rw_exit(&ds->ds_rwlock);
753 gotit = TRUE;
754 }
755 mutex_exit(&ds->ds_lock);
756 return (gotit);
757 }
758
759 void
760 dsl_dataset_make_exclusive(dsl_dataset_t *ds, void *owner)
761 {
762 ASSERT3P(owner, ==, ds->ds_owner);
763 if (!RW_WRITE_HELD(&ds->ds_rwlock))
764 rw_enter(&ds->ds_rwlock, RW_WRITER);
765 }
766
767 uint64_t
768 dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin,
769 uint64_t flags, dmu_tx_t *tx)
770 {
771 dsl_pool_t *dp = dd->dd_pool;
772 dmu_buf_t *dbuf;
773 dsl_dataset_phys_t *dsphys;
774 uint64_t dsobj;
775 objset_t *mos = dp->dp_meta_objset;
776
777 if (origin == NULL)
778 origin = dp->dp_origin_snap;
779
780 ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp);
781 ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0);
782 ASSERT(dmu_tx_is_syncing(tx));
783 ASSERT(dd->dd_phys->dd_head_dataset_obj == 0);
784
785 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
786 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
787 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
788 dmu_buf_will_dirty(dbuf, tx);
789 dsphys = dbuf->db_data;
790 bzero(dsphys, sizeof (dsl_dataset_phys_t));
791 dsphys->ds_dir_obj = dd->dd_object;
792 dsphys->ds_flags = flags;
793 dsphys->ds_fsid_guid = unique_create();
794 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
795 sizeof (dsphys->ds_guid));
796 dsphys->ds_snapnames_zapobj =
797 zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP,
798 DMU_OT_NONE, 0, tx);
799 dsphys->ds_creation_time = gethrestime_sec();
800 dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg;
801
802 if (origin == NULL) {
803 dsphys->ds_deadlist_obj = dsl_deadlist_alloc(mos, tx);
804 } else {
805 dsl_dataset_t *ohds;
806
807 dsphys->ds_prev_snap_obj = origin->ds_object;
808 dsphys->ds_prev_snap_txg =
809 origin->ds_phys->ds_creation_txg;
810 dsphys->ds_referenced_bytes =
811 origin->ds_phys->ds_referenced_bytes;
812 dsphys->ds_compressed_bytes =
813 origin->ds_phys->ds_compressed_bytes;
814 dsphys->ds_uncompressed_bytes =
815 origin->ds_phys->ds_uncompressed_bytes;
816 dsphys->ds_bp = origin->ds_phys->ds_bp;
817 dsphys->ds_flags |= origin->ds_phys->ds_flags;
818
819 dmu_buf_will_dirty(origin->ds_dbuf, tx);
820 origin->ds_phys->ds_num_children++;
821
822 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
823 origin->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ohds));
824 dsphys->ds_deadlist_obj = dsl_deadlist_clone(&ohds->ds_deadlist,
825 dsphys->ds_prev_snap_txg, dsphys->ds_prev_snap_obj, tx);
826 dsl_dataset_rele(ohds, FTAG);
827
828 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) {
829 if (origin->ds_phys->ds_next_clones_obj == 0) {
830 origin->ds_phys->ds_next_clones_obj =
831 zap_create(mos,
832 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx);
833 }
834 VERIFY(0 == zap_add_int(mos,
835 origin->ds_phys->ds_next_clones_obj,
836 dsobj, tx));
837 }
838
839 dmu_buf_will_dirty(dd->dd_dbuf, tx);
840 dd->dd_phys->dd_origin_obj = origin->ds_object;
841 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
842 if (origin->ds_dir->dd_phys->dd_clones == 0) {
843 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx);
844 origin->ds_dir->dd_phys->dd_clones =
845 zap_create(mos,
846 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
847 }
848 VERIFY3U(0, ==, zap_add_int(mos,
849 origin->ds_dir->dd_phys->dd_clones, dsobj, tx));
850 }
851 }
852
853 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
854 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
855
856 dmu_buf_rele(dbuf, FTAG);
857
858 dmu_buf_will_dirty(dd->dd_dbuf, tx);
859 dd->dd_phys->dd_head_dataset_obj = dsobj;
860
861 return (dsobj);
862 }
863
864 uint64_t
865 dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname,
866 dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx)
867 {
868 dsl_pool_t *dp = pdd->dd_pool;
869 uint64_t dsobj, ddobj;
870 dsl_dir_t *dd;
871
872 ASSERT(lastname[0] != '@');
873
874 ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx);
875 VERIFY(0 == dsl_dir_open_obj(dp, ddobj, lastname, FTAG, &dd));
876
877 dsobj = dsl_dataset_create_sync_dd(dd, origin, flags, tx);
878
879 dsl_deleg_set_create_perms(dd, tx, cr);
880
881 dsl_dir_close(dd, FTAG);
882
883 /*
884 * If we are creating a clone, make sure we zero out any stale
885 * data from the origin snapshots zil header.
886 */
887 if (origin != NULL) {
888 dsl_dataset_t *ds;
889 objset_t *os;
890
891 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
892 VERIFY3U(0, ==, dmu_objset_from_ds(ds, &os));
893 bzero(&os->os_zil_header, sizeof (os->os_zil_header));
894 dsl_dataset_dirty(ds, tx);
895 dsl_dataset_rele(ds, FTAG);
896 }
897
898 return (dsobj);
899 }
900
901 /*
902 * The snapshots must all be in the same pool.
903 */
904 int
905 dmu_snapshots_destroy_nvl(nvlist_t *snaps, boolean_t defer,
906 nvlist_t *errlist)
907 {
908 int err;
909 dsl_sync_task_t *dst;
910 spa_t *spa;
911 nvpair_t *pair;
912 dsl_sync_task_group_t *dstg;
913
914 pair = nvlist_next_nvpair(snaps, NULL);
915 if (pair == NULL)
916 return (0);
917
918 err = spa_open(nvpair_name(pair), &spa, FTAG);
919 if (err)
920 return (err);
921 dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
922
923 for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL;
924 pair = nvlist_next_nvpair(snaps, pair)) {
925 dsl_dataset_t *ds;
926
927 err = dsl_dataset_own(nvpair_name(pair), B_TRUE, dstg, &ds);
928 if (err == 0) {
929 struct dsl_ds_destroyarg *dsda;
930
931 dsl_dataset_make_exclusive(ds, dstg);
932 dsda = kmem_zalloc(sizeof (struct dsl_ds_destroyarg),
933 KM_SLEEP);
934 dsda->ds = ds;
935 dsda->defer = defer;
936 dsl_sync_task_create(dstg, dsl_dataset_destroy_check,
937 dsl_dataset_destroy_sync, dsda, dstg, 0);
938 } else if (err == ENOENT) {
939 err = 0;
940 } else {
941 fnvlist_add_int32(errlist, nvpair_name(pair), err);
942 break;
943 }
944 }
945
946 if (err == 0)
947 err = dsl_sync_task_group_wait(dstg);
948
949 for (dst = list_head(&dstg->dstg_tasks); dst;
950 dst = list_next(&dstg->dstg_tasks, dst)) {
951 struct dsl_ds_destroyarg *dsda = dst->dst_arg1;
952 dsl_dataset_t *ds = dsda->ds;
953
954 /*
955 * Return the snapshots that triggered the error.
956 */
957 if (dst->dst_err != 0) {
958 char name[ZFS_MAXNAMELEN];
959 dsl_dataset_name(ds, name);
960 fnvlist_add_int32(errlist, name, dst->dst_err);
961 }
962 ASSERT3P(dsda->rm_origin, ==, NULL);
963 dsl_dataset_disown(ds, dstg);
964 kmem_free(dsda, sizeof (struct dsl_ds_destroyarg));
965 }
966
967 dsl_sync_task_group_destroy(dstg);
968 spa_close(spa, FTAG);
969 return (err);
970
971 }
972
973 static boolean_t
974 dsl_dataset_might_destroy_origin(dsl_dataset_t *ds)
975 {
976 boolean_t might_destroy = B_FALSE;
977
978 mutex_enter(&ds->ds_lock);
979 if (ds->ds_phys->ds_num_children == 2 && ds->ds_userrefs == 0 &&
980 DS_IS_DEFER_DESTROY(ds))
981 might_destroy = B_TRUE;
982 mutex_exit(&ds->ds_lock);
983
984 return (might_destroy);
985 }
986
987 /*
988 * If we're removing a clone, and these three conditions are true:
989 * 1) the clone's origin has no other children
990 * 2) the clone's origin has no user references
991 * 3) the clone's origin has been marked for deferred destruction
992 * Then, prepare to remove the origin as part of this sync task group.
993 */
994 static int
995 dsl_dataset_origin_rm_prep(struct dsl_ds_destroyarg *dsda, void *tag)
996 {
997 dsl_dataset_t *ds = dsda->ds;
998 dsl_dataset_t *origin = ds->ds_prev;
999
1000 if (dsl_dataset_might_destroy_origin(origin)) {
1001 char *name;
1002 int namelen;
1003 int error;
1004
1005 namelen = dsl_dataset_namelen(origin) + 1;
1006 name = kmem_alloc(namelen, KM_SLEEP);
1007 dsl_dataset_name(origin, name);
1008 #ifdef _KERNEL
1009 error = zfs_unmount_snap(name, NULL);
1010 if (error) {
1011 kmem_free(name, namelen);
1012 return (error);
1013 }
1014 #endif
1015 error = dsl_dataset_own(name, B_TRUE, tag, &origin);
1016 kmem_free(name, namelen);
1017 if (error)
1018 return (error);
1019 dsda->rm_origin = origin;
1020 dsl_dataset_make_exclusive(origin, tag);
1021 }
1022
1023 return (0);
1024 }
1025
1026 /*
1027 * ds must be opened as OWNER. On return (whether successful or not),
1028 * ds will be closed and caller can no longer dereference it.
1029 */
1030 int
1031 dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer)
1032 {
1033 int err;
1034 dsl_sync_task_group_t *dstg;
1035 objset_t *os;
1036 dsl_dir_t *dd;
1037 uint64_t obj;
1038 struct dsl_ds_destroyarg dsda = { 0 };
1039
1040 dsda.ds = ds;
1041
1042 if (dsl_dataset_is_snapshot(ds)) {
1043 /* Destroying a snapshot is simpler */
1044 dsl_dataset_make_exclusive(ds, tag);
1045
1046 dsda.defer = defer;
1047 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
1048 dsl_dataset_destroy_check, dsl_dataset_destroy_sync,
1049 &dsda, tag, 0);
1050 ASSERT3P(dsda.rm_origin, ==, NULL);
1051 goto out;
1052 } else if (defer) {
1053 err = EINVAL;
1054 goto out;
1055 }
1056
1057 dd = ds->ds_dir;
1058
1059 if (!spa_feature_is_enabled(dsl_dataset_get_spa(ds),
1060 &spa_feature_table[SPA_FEATURE_ASYNC_DESTROY])) {
1061 /*
1062 * Check for errors and mark this ds as inconsistent, in
1063 * case we crash while freeing the objects.
1064 */
1065 err = dsl_sync_task_do(dd->dd_pool,
1066 dsl_dataset_destroy_begin_check,
1067 dsl_dataset_destroy_begin_sync, ds, NULL, 0);
1068 if (err)
1069 goto out;
1070
1071 err = dmu_objset_from_ds(ds, &os);
1072 if (err)
1073 goto out;
1074
1075 /*
1076 * Remove all objects while in the open context so that
1077 * there is less work to do in the syncing context.
1078 */
1079 for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE,
1080 ds->ds_phys->ds_prev_snap_txg)) {
1081 /*
1082 * Ignore errors, if there is not enough disk space
1083 * we will deal with it in dsl_dataset_destroy_sync().
1084 */
1085 (void) dmu_free_object(os, obj);
1086 }
1087 if (err != ESRCH)
1088 goto out;
1089
1090 /*
1091 * Sync out all in-flight IO.
1092 */
1093 txg_wait_synced(dd->dd_pool, 0);
1094
1095 /*
1096 * If we managed to free all the objects in open
1097 * context, the user space accounting should be zero.
1098 */
1099 if (ds->ds_phys->ds_bp.blk_fill == 0 &&
1100 dmu_objset_userused_enabled(os)) {
1101 uint64_t count;
1102
1103 ASSERT(zap_count(os, DMU_USERUSED_OBJECT,
1104 &count) != 0 || count == 0);
1105 ASSERT(zap_count(os, DMU_GROUPUSED_OBJECT,
1106 &count) != 0 || count == 0);
1107 }
1108 }
1109
1110 rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
1111 err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd);
1112 rw_exit(&dd->dd_pool->dp_config_rwlock);
1113
1114 if (err)
1115 goto out;
1116
1117 /*
1118 * Blow away the dsl_dir + head dataset.
1119 */
1120 dsl_dataset_make_exclusive(ds, tag);
1121 /*
1122 * If we're removing a clone, we might also need to remove its
1123 * origin.
1124 */
1125 do {
1126 dsda.need_prep = B_FALSE;
1127 if (dsl_dir_is_clone(dd)) {
1128 err = dsl_dataset_origin_rm_prep(&dsda, tag);
1129 if (err) {
1130 dsl_dir_close(dd, FTAG);
1131 goto out;
1132 }
1133 }
1134
1135 dstg = dsl_sync_task_group_create(ds->ds_dir->dd_pool);
1136 dsl_sync_task_create(dstg, dsl_dataset_destroy_check,
1137 dsl_dataset_destroy_sync, &dsda, tag, 0);
1138 dsl_sync_task_create(dstg, dsl_dir_destroy_check,
1139 dsl_dir_destroy_sync, dd, FTAG, 0);
1140 err = dsl_sync_task_group_wait(dstg);
1141 dsl_sync_task_group_destroy(dstg);
1142
1143 /*
1144 * We could be racing against 'zfs release' or 'zfs destroy -d'
1145 * on the origin snap, in which case we can get EBUSY if we
1146 * needed to destroy the origin snap but were not ready to
1147 * do so.
1148 */
1149 if (dsda.need_prep) {
1150 ASSERT(err == EBUSY);
1151 ASSERT(dsl_dir_is_clone(dd));
1152 ASSERT(dsda.rm_origin == NULL);
1153 }
1154 } while (dsda.need_prep);
1155
1156 if (dsda.rm_origin != NULL)
1157 dsl_dataset_disown(dsda.rm_origin, tag);
1158
1159 /* if it is successful, dsl_dir_destroy_sync will close the dd */
1160 if (err)
1161 dsl_dir_close(dd, FTAG);
1162 out:
1163 dsl_dataset_disown(ds, tag);
1164 return (err);
1165 }
1166
1167 blkptr_t *
1168 dsl_dataset_get_blkptr(dsl_dataset_t *ds)
1169 {
1170 return (&ds->ds_phys->ds_bp);
1171 }
1172
1173 void
1174 dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx)
1175 {
1176 ASSERT(dmu_tx_is_syncing(tx));
1177 /* If it's the meta-objset, set dp_meta_rootbp */
1178 if (ds == NULL) {
1179 tx->tx_pool->dp_meta_rootbp = *bp;
1180 } else {
1181 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1182 ds->ds_phys->ds_bp = *bp;
1183 }
1184 }
1185
1186 spa_t *
1187 dsl_dataset_get_spa(dsl_dataset_t *ds)
1188 {
1189 return (ds->ds_dir->dd_pool->dp_spa);
1190 }
1191
1192 void
1193 dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx)
1194 {
1195 dsl_pool_t *dp;
1196
1197 if (ds == NULL) /* this is the meta-objset */
1198 return;
1199
1200 ASSERT(ds->ds_objset != NULL);
1201
1202 if (ds->ds_phys->ds_next_snap_obj != 0)
1203 panic("dirtying snapshot!");
1204
1205 dp = ds->ds_dir->dd_pool;
1206
1207 if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg) == 0) {
1208 /* up the hold count until we can be written out */
1209 dmu_buf_add_ref(ds->ds_dbuf, ds);
1210 }
1211 }
1212
1213 boolean_t
1214 dsl_dataset_is_dirty(dsl_dataset_t *ds)
1215 {
1216 for (int t = 0; t < TXG_SIZE; t++) {
1217 if (txg_list_member(&ds->ds_dir->dd_pool->dp_dirty_datasets,
1218 ds, t))
1219 return (B_TRUE);
1220 }
1221 return (B_FALSE);
1222 }
1223
1224 /*
1225 * The unique space in the head dataset can be calculated by subtracting
1226 * the space used in the most recent snapshot, that is still being used
1227 * in this file system, from the space currently in use. To figure out
1228 * the space in the most recent snapshot still in use, we need to take
1229 * the total space used in the snapshot and subtract out the space that
1230 * has been freed up since the snapshot was taken.
1231 */
1232 static void
1233 dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds)
1234 {
1235 uint64_t mrs_used;
1236 uint64_t dlused, dlcomp, dluncomp;
1237
1238 ASSERT(!dsl_dataset_is_snapshot(ds));
1239
1240 if (ds->ds_phys->ds_prev_snap_obj != 0)
1241 mrs_used = ds->ds_prev->ds_phys->ds_referenced_bytes;
1242 else
1243 mrs_used = 0;
1244
1245 dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp);
1246
1247 ASSERT3U(dlused, <=, mrs_used);
1248 ds->ds_phys->ds_unique_bytes =
1249 ds->ds_phys->ds_referenced_bytes - (mrs_used - dlused);
1250
1251 if (spa_version(ds->ds_dir->dd_pool->dp_spa) >=
1252 SPA_VERSION_UNIQUE_ACCURATE)
1253 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
1254 }
1255
1256 struct killarg {
1257 dsl_dataset_t *ds;
1258 dmu_tx_t *tx;
1259 };
1260
1261 /* ARGSUSED */
1262 static int
1263 kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf,
1264 const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
1265 {
1266 struct killarg *ka = arg;
1267 dmu_tx_t *tx = ka->tx;
1268
1269 if (bp == NULL)
1270 return (0);
1271
1272 if (zb->zb_level == ZB_ZIL_LEVEL) {
1273 ASSERT(zilog != NULL);
1274 /*
1275 * It's a block in the intent log. It has no
1276 * accounting, so just free it.
1277 */
1278 dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp);
1279 } else {
1280 ASSERT(zilog == NULL);
1281 ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg);
1282 (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE);
1283 }
1284
1285 return (0);
1286 }
1287
1288 /* ARGSUSED */
1289 static int
1290 dsl_dataset_destroy_begin_check(void *arg1, void *arg2, dmu_tx_t *tx)
1291 {
1292 dsl_dataset_t *ds = arg1;
1293 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1294 uint64_t count;
1295 int err;
1296
1297 /*
1298 * Can't delete a head dataset if there are snapshots of it.
1299 * (Except if the only snapshots are from the branch we cloned
1300 * from.)
1301 */
1302 if (ds->ds_prev != NULL &&
1303 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object)
1304 return (EBUSY);
1305
1306 /*
1307 * This is really a dsl_dir thing, but check it here so that
1308 * we'll be less likely to leave this dataset inconsistent &
1309 * nearly destroyed.
1310 */
1311 err = zap_count(mos, ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count);
1312 if (err)
1313 return (err);
1314 if (count != 0)
1315 return (EEXIST);
1316
1317 return (0);
1318 }
1319
1320 /* ARGSUSED */
1321 static void
1322 dsl_dataset_destroy_begin_sync(void *arg1, void *arg2, dmu_tx_t *tx)
1323 {
1324 dsl_dataset_t *ds = arg1;
1325
1326 /* Mark it as inconsistent on-disk, in case we crash */
1327 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1328 ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT;
1329
1330 spa_history_log_internal_ds(ds, "destroy begin", tx, "");
1331 }
1332
1333 static int
1334 dsl_dataset_origin_check(struct dsl_ds_destroyarg *dsda, void *tag,
1335 dmu_tx_t *tx)
1336 {
1337 dsl_dataset_t *ds = dsda->ds;
1338 dsl_dataset_t *ds_prev = ds->ds_prev;
1339
1340 if (dsl_dataset_might_destroy_origin(ds_prev)) {
1341 struct dsl_ds_destroyarg ndsda = {0};
1342
1343 /*
1344 * If we're not prepared to remove the origin, don't remove
1345 * the clone either.
1346 */
1347 if (dsda->rm_origin == NULL) {
1348 dsda->need_prep = B_TRUE;
1349 return (EBUSY);
1350 }
1351
1352 ndsda.ds = ds_prev;
1353 ndsda.is_origin_rm = B_TRUE;
1354 return (dsl_dataset_destroy_check(&ndsda, tag, tx));
1355 }
1356
1357 /*
1358 * If we're not going to remove the origin after all,
1359 * undo the open context setup.
1360 */
1361 if (dsda->rm_origin != NULL) {
1362 dsl_dataset_disown(dsda->rm_origin, tag);
1363 dsda->rm_origin = NULL;
1364 }
1365
1366 return (0);
1367 }
1368
1369 /*
1370 * If you add new checks here, you may need to add
1371 * additional checks to the "temporary" case in
1372 * snapshot_check() in dmu_objset.c.
1373 */
1374 /* ARGSUSED */
1375 int
1376 dsl_dataset_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx)
1377 {
1378 struct dsl_ds_destroyarg *dsda = arg1;
1379 dsl_dataset_t *ds = dsda->ds;
1380
1381 /* we have an owner hold, so noone else can destroy us */
1382 ASSERT(!DSL_DATASET_IS_DESTROYED(ds));
1383
1384 /*
1385 * Only allow deferred destroy on pools that support it.
1386 * NOTE: deferred destroy is only supported on snapshots.
1387 */
1388 if (dsda->defer) {
1389 if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
1390 SPA_VERSION_USERREFS)
1391 return (ENOTSUP);
1392 ASSERT(dsl_dataset_is_snapshot(ds));
1393 return (0);
1394 }
1395
1396 /*
1397 * Can't delete a head dataset if there are snapshots of it.
1398 * (Except if the only snapshots are from the branch we cloned
1399 * from.)
1400 */
1401 if (ds->ds_prev != NULL &&
1402 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object)
1403 return (EBUSY);
1404
1405 /*
1406 * If we made changes this txg, traverse_dsl_dataset won't find
1407 * them. Try again.
1408 */
1409 if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg)
1410 return (EAGAIN);
1411
1412 if (dsl_dataset_is_snapshot(ds)) {
1413 /*
1414 * If this snapshot has an elevated user reference count,
1415 * we can't destroy it yet.
1416 */
1417 if (ds->ds_userrefs > 0 && !dsda->releasing)
1418 return (EBUSY);
1419
1420 mutex_enter(&ds->ds_lock);
1421 /*
1422 * Can't delete a branch point. However, if we're destroying
1423 * a clone and removing its origin due to it having a user
1424 * hold count of 0 and having been marked for deferred destroy,
1425 * it's OK for the origin to have a single clone.
1426 */
1427 if (ds->ds_phys->ds_num_children >
1428 (dsda->is_origin_rm ? 2 : 1)) {
1429 mutex_exit(&ds->ds_lock);
1430 return (EEXIST);
1431 }
1432 mutex_exit(&ds->ds_lock);
1433 } else if (dsl_dir_is_clone(ds->ds_dir)) {
1434 return (dsl_dataset_origin_check(dsda, arg2, tx));
1435 }
1436
1437 /* XXX we should do some i/o error checking... */
1438 return (0);
1439 }
1440
1441 struct refsarg {
1442 kmutex_t lock;
1443 boolean_t gone;
1444 kcondvar_t cv;
1445 };
1446
1447 /* ARGSUSED */
1448 static void
1449 dsl_dataset_refs_gone(dmu_buf_t *db, void *argv)
1450 {
1451 struct refsarg *arg = argv;
1452
1453 mutex_enter(&arg->lock);
1454 arg->gone = TRUE;
1455 cv_signal(&arg->cv);
1456 mutex_exit(&arg->lock);
1457 }
1458
1459 static void
1460 dsl_dataset_drain_refs(dsl_dataset_t *ds, void *tag)
1461 {
1462 struct refsarg arg;
1463
1464 mutex_init(&arg.lock, NULL, MUTEX_DEFAULT, NULL);
1465 cv_init(&arg.cv, NULL, CV_DEFAULT, NULL);
1466 arg.gone = FALSE;
1467 (void) dmu_buf_update_user(ds->ds_dbuf, ds, &arg, &ds->ds_phys,
1468 dsl_dataset_refs_gone);
1469 dmu_buf_rele(ds->ds_dbuf, tag);
1470 mutex_enter(&arg.lock);
1471 while (!arg.gone)
1472 cv_wait(&arg.cv, &arg.lock);
1473 ASSERT(arg.gone);
1474 mutex_exit(&arg.lock);
1475 ds->ds_dbuf = NULL;
1476 ds->ds_phys = NULL;
1477 mutex_destroy(&arg.lock);
1478 cv_destroy(&arg.cv);
1479 }
1480
1481 static void
1482 remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj, dmu_tx_t *tx)
1483 {
1484 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1485 uint64_t count;
1486 int err;
1487
1488 ASSERT(ds->ds_phys->ds_num_children >= 2);
1489 err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx);
1490 /*
1491 * The err should not be ENOENT, but a bug in a previous version
1492 * of the code could cause upgrade_clones_cb() to not set
1493 * ds_next_snap_obj when it should, leading to a missing entry.
1494 * If we knew that the pool was created after
1495 * SPA_VERSION_NEXT_CLONES, we could assert that it isn't
1496 * ENOENT. However, at least we can check that we don't have
1497 * too many entries in the next_clones_obj even after failing to
1498 * remove this one.
1499 */
1500 if (err != ENOENT) {
1501 VERIFY0(err);
1502 }
1503 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj,
1504 &count));
1505 ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2);
1506 }
1507
1508 static void
1509 dsl_dataset_remove_clones_key(dsl_dataset_t *ds, uint64_t mintxg, dmu_tx_t *tx)
1510 {
1511 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1512 zap_cursor_t zc;
1513 zap_attribute_t za;
1514
1515 /*
1516 * If it is the old version, dd_clones doesn't exist so we can't
1517 * find the clones, but deadlist_remove_key() is a no-op so it
1518 * doesn't matter.
1519 */
1520 if (ds->ds_dir->dd_phys->dd_clones == 0)
1521 return;
1522
1523 for (zap_cursor_init(&zc, mos, ds->ds_dir->dd_phys->dd_clones);
1524 zap_cursor_retrieve(&zc, &za) == 0;
1525 zap_cursor_advance(&zc)) {
1526 dsl_dataset_t *clone;
1527
1528 VERIFY3U(0, ==, dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
1529 za.za_first_integer, FTAG, &clone));
1530 if (clone->ds_dir->dd_origin_txg > mintxg) {
1531 dsl_deadlist_remove_key(&clone->ds_deadlist,
1532 mintxg, tx);
1533 dsl_dataset_remove_clones_key(clone, mintxg, tx);
1534 }
1535 dsl_dataset_rele(clone, FTAG);
1536 }
1537 zap_cursor_fini(&zc);
1538 }
1539
1540 struct process_old_arg {
1541 dsl_dataset_t *ds;
1542 dsl_dataset_t *ds_prev;
1543 boolean_t after_branch_point;
1544 zio_t *pio;
1545 uint64_t used, comp, uncomp;
1546 };
1547
1548 static int
1549 process_old_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
1550 {
1551 struct process_old_arg *poa = arg;
1552 dsl_pool_t *dp = poa->ds->ds_dir->dd_pool;
1553
1554 if (bp->blk_birth <= poa->ds->ds_phys->ds_prev_snap_txg) {
1555 dsl_deadlist_insert(&poa->ds->ds_deadlist, bp, tx);
1556 if (poa->ds_prev && !poa->after_branch_point &&
1557 bp->blk_birth >
1558 poa->ds_prev->ds_phys->ds_prev_snap_txg) {
1559 poa->ds_prev->ds_phys->ds_unique_bytes +=
1560 bp_get_dsize_sync(dp->dp_spa, bp);
1561 }
1562 } else {
1563 poa->used += bp_get_dsize_sync(dp->dp_spa, bp);
1564 poa->comp += BP_GET_PSIZE(bp);
1565 poa->uncomp += BP_GET_UCSIZE(bp);
1566 dsl_free_sync(poa->pio, dp, tx->tx_txg, bp);
1567 }
1568 return (0);
1569 }
1570
1571 static void
1572 process_old_deadlist(dsl_dataset_t *ds, dsl_dataset_t *ds_prev,
1573 dsl_dataset_t *ds_next, boolean_t after_branch_point, dmu_tx_t *tx)
1574 {
1575 struct process_old_arg poa = { 0 };
1576 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1577 objset_t *mos = dp->dp_meta_objset;
1578
1579 ASSERT(ds->ds_deadlist.dl_oldfmt);
1580 ASSERT(ds_next->ds_deadlist.dl_oldfmt);
1581
1582 poa.ds = ds;
1583 poa.ds_prev = ds_prev;
1584 poa.after_branch_point = after_branch_point;
1585 poa.pio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
1586 VERIFY3U(0, ==, bpobj_iterate(&ds_next->ds_deadlist.dl_bpobj,
1587 process_old_cb, &poa, tx));
1588 VERIFY0(zio_wait(poa.pio));
1589 ASSERT3U(poa.used, ==, ds->ds_phys->ds_unique_bytes);
1590
1591 /* change snapused */
1592 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
1593 -poa.used, -poa.comp, -poa.uncomp, tx);
1594
1595 /* swap next's deadlist to our deadlist */
1596 dsl_deadlist_close(&ds->ds_deadlist);
1597 dsl_deadlist_close(&ds_next->ds_deadlist);
1598 SWITCH64(ds_next->ds_phys->ds_deadlist_obj,
1599 ds->ds_phys->ds_deadlist_obj);
1600 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj);
1601 dsl_deadlist_open(&ds_next->ds_deadlist, mos,
1602 ds_next->ds_phys->ds_deadlist_obj);
1603 }
1604
1605 static int
1606 old_synchronous_dataset_destroy(dsl_dataset_t *ds, dmu_tx_t *tx)
1607 {
1608 int err;
1609 struct killarg ka;
1610
1611 /*
1612 * Free everything that we point to (that's born after
1613 * the previous snapshot, if we are a clone)
1614 *
1615 * NB: this should be very quick, because we already
1616 * freed all the objects in open context.
1617 */
1618 ka.ds = ds;
1619 ka.tx = tx;
1620 err = traverse_dataset(ds,
1621 ds->ds_phys->ds_prev_snap_txg, TRAVERSE_POST,
1622 kill_blkptr, &ka);
1623 ASSERT0(err);
1624 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) || ds->ds_phys->ds_unique_bytes == 0);
1625
1626 return (err);
1627 }
1628
1629 void
1630 dsl_dataset_destroy_sync(void *arg1, void *tag, dmu_tx_t *tx)
1631 {
1632 struct dsl_ds_destroyarg *dsda = arg1;
1633 dsl_dataset_t *ds = dsda->ds;
1634 int err;
1635 int after_branch_point = FALSE;
1636 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1637 objset_t *mos = dp->dp_meta_objset;
1638 dsl_dataset_t *ds_prev = NULL;
1639 boolean_t wont_destroy;
1640 uint64_t obj;
1641
1642 wont_destroy = (dsda->defer &&
1643 (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1));
1644
1645 ASSERT(ds->ds_owner || wont_destroy);
1646 ASSERT(dsda->defer || ds->ds_phys->ds_num_children <= 1);
1647 ASSERT(ds->ds_prev == NULL ||
1648 ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object);
1649 ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg);
1650
1651 if (wont_destroy) {
1652 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
1653 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1654 ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY;
1655 spa_history_log_internal_ds(ds, "defer_destroy", tx, "");
1656 return;
1657 }
1658
1659 /* We need to log before removing it from the namespace. */
1660 spa_history_log_internal_ds(ds, "destroy", tx, "");
1661
1662 /* signal any waiters that this dataset is going away */
1663 mutex_enter(&ds->ds_lock);
1664 ds->ds_owner = dsl_reaper;
1665 cv_broadcast(&ds->ds_exclusive_cv);
1666 mutex_exit(&ds->ds_lock);
1667
1668 /* Remove our reservation */
1669 if (ds->ds_reserved != 0) {
1670 dsl_prop_setarg_t psa;
1671 uint64_t value = 0;
1672
1673 dsl_prop_setarg_init_uint64(&psa, "refreservation",
1674 (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED),
1675 &value);
1676 psa.psa_effective_value = 0; /* predict default value */
1677
1678 dsl_dataset_set_reservation_sync(ds, &psa, tx);
1679 ASSERT0(ds->ds_reserved);
1680 }
1681
1682 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
1683
1684 dsl_scan_ds_destroyed(ds, tx);
1685
1686 obj = ds->ds_object;
1687
1688 if (ds->ds_phys->ds_prev_snap_obj != 0) {
1689 if (ds->ds_prev) {
1690 ds_prev = ds->ds_prev;
1691 } else {
1692 VERIFY(0 == dsl_dataset_hold_obj(dp,
1693 ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev));
1694 }
1695 after_branch_point =
1696 (ds_prev->ds_phys->ds_next_snap_obj != obj);
1697
1698 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx);
1699 if (after_branch_point &&
1700 ds_prev->ds_phys->ds_next_clones_obj != 0) {
1701 remove_from_next_clones(ds_prev, obj, tx);
1702 if (ds->ds_phys->ds_next_snap_obj != 0) {
1703 VERIFY(0 == zap_add_int(mos,
1704 ds_prev->ds_phys->ds_next_clones_obj,
1705 ds->ds_phys->ds_next_snap_obj, tx));
1706 }
1707 }
1708 if (after_branch_point &&
1709 ds->ds_phys->ds_next_snap_obj == 0) {
1710 /* This clone is toast. */
1711 ASSERT(ds_prev->ds_phys->ds_num_children > 1);
1712 ds_prev->ds_phys->ds_num_children--;
1713
1714 /*
1715 * If the clone's origin has no other clones, no
1716 * user holds, and has been marked for deferred
1717 * deletion, then we should have done the necessary
1718 * destroy setup for it.
1719 */
1720 if (ds_prev->ds_phys->ds_num_children == 1 &&
1721 ds_prev->ds_userrefs == 0 &&
1722 DS_IS_DEFER_DESTROY(ds_prev)) {
1723 ASSERT3P(dsda->rm_origin, !=, NULL);
1724 } else {
1725 ASSERT3P(dsda->rm_origin, ==, NULL);
1726 }
1727 } else if (!after_branch_point) {
1728 ds_prev->ds_phys->ds_next_snap_obj =
1729 ds->ds_phys->ds_next_snap_obj;
1730 }
1731 }
1732
1733 if (dsl_dataset_is_snapshot(ds)) {
1734 dsl_dataset_t *ds_next;
1735 uint64_t old_unique;
1736 uint64_t used = 0, comp = 0, uncomp = 0;
1737
1738 VERIFY(0 == dsl_dataset_hold_obj(dp,
1739 ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next));
1740 ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj);
1741
1742 old_unique = ds_next->ds_phys->ds_unique_bytes;
1743
1744 dmu_buf_will_dirty(ds_next->ds_dbuf, tx);
1745 ds_next->ds_phys->ds_prev_snap_obj =
1746 ds->ds_phys->ds_prev_snap_obj;
1747 ds_next->ds_phys->ds_prev_snap_txg =
1748 ds->ds_phys->ds_prev_snap_txg;
1749 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
1750 ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0);
1751
1752
1753 if (ds_next->ds_deadlist.dl_oldfmt) {
1754 process_old_deadlist(ds, ds_prev, ds_next,
1755 after_branch_point, tx);
1756 } else {
1757 /* Adjust prev's unique space. */
1758 if (ds_prev && !after_branch_point) {
1759 dsl_deadlist_space_range(&ds_next->ds_deadlist,
1760 ds_prev->ds_phys->ds_prev_snap_txg,
1761 ds->ds_phys->ds_prev_snap_txg,
1762 &used, &comp, &uncomp);
1763 ds_prev->ds_phys->ds_unique_bytes += used;
1764 }
1765
1766 /* Adjust snapused. */
1767 dsl_deadlist_space_range(&ds_next->ds_deadlist,
1768 ds->ds_phys->ds_prev_snap_txg, UINT64_MAX,
1769 &used, &comp, &uncomp);
1770 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
1771 -used, -comp, -uncomp, tx);
1772
1773 /* Move blocks to be freed to pool's free list. */
1774 dsl_deadlist_move_bpobj(&ds_next->ds_deadlist,
1775 &dp->dp_free_bpobj, ds->ds_phys->ds_prev_snap_txg,
1776 tx);
1777 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir,
1778 DD_USED_HEAD, used, comp, uncomp, tx);
1779
1780 /* Merge our deadlist into next's and free it. */
1781 dsl_deadlist_merge(&ds_next->ds_deadlist,
1782 ds->ds_phys->ds_deadlist_obj, tx);
1783 }
1784 dsl_deadlist_close(&ds->ds_deadlist);
1785 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx);
1786
1787 /* Collapse range in clone heads */
1788 dsl_dataset_remove_clones_key(ds,
1789 ds->ds_phys->ds_creation_txg, tx);
1790
1791 if (dsl_dataset_is_snapshot(ds_next)) {
1792 dsl_dataset_t *ds_nextnext;
1793
1794 /*
1795 * Update next's unique to include blocks which
1796 * were previously shared by only this snapshot
1797 * and it. Those blocks will be born after the
1798 * prev snap and before this snap, and will have
1799 * died after the next snap and before the one
1800 * after that (ie. be on the snap after next's
1801 * deadlist).
1802 */
1803 VERIFY(0 == dsl_dataset_hold_obj(dp,
1804 ds_next->ds_phys->ds_next_snap_obj,
1805 FTAG, &ds_nextnext));
1806 dsl_deadlist_space_range(&ds_nextnext->ds_deadlist,
1807 ds->ds_phys->ds_prev_snap_txg,
1808 ds->ds_phys->ds_creation_txg,
1809 &used, &comp, &uncomp);
1810 ds_next->ds_phys->ds_unique_bytes += used;
1811 dsl_dataset_rele(ds_nextnext, FTAG);
1812 ASSERT3P(ds_next->ds_prev, ==, NULL);
1813
1814 /* Collapse range in this head. */
1815 dsl_dataset_t *hds;
1816 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
1817 ds->ds_dir->dd_phys->dd_head_dataset_obj,
1818 FTAG, &hds));
1819 dsl_deadlist_remove_key(&hds->ds_deadlist,
1820 ds->ds_phys->ds_creation_txg, tx);
1821 dsl_dataset_rele(hds, FTAG);
1822
1823 } else {
1824 ASSERT3P(ds_next->ds_prev, ==, ds);
1825 dsl_dataset_drop_ref(ds_next->ds_prev, ds_next);
1826 ds_next->ds_prev = NULL;
1827 if (ds_prev) {
1828 VERIFY(0 == dsl_dataset_get_ref(dp,
1829 ds->ds_phys->ds_prev_snap_obj,
1830 ds_next, &ds_next->ds_prev));
1831 }
1832
1833 dsl_dataset_recalc_head_uniq(ds_next);
1834
1835 /*
1836 * Reduce the amount of our unconsmed refreservation
1837 * being charged to our parent by the amount of
1838 * new unique data we have gained.
1839 */
1840 if (old_unique < ds_next->ds_reserved) {
1841 int64_t mrsdelta;
1842 uint64_t new_unique =
1843 ds_next->ds_phys->ds_unique_bytes;
1844
1845 ASSERT(old_unique <= new_unique);
1846 mrsdelta = MIN(new_unique - old_unique,
1847 ds_next->ds_reserved - old_unique);
1848 dsl_dir_diduse_space(ds->ds_dir,
1849 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx);
1850 }
1851 }
1852 dsl_dataset_rele(ds_next, FTAG);
1853 } else {
1854 zfeature_info_t *async_destroy =
1855 &spa_feature_table[SPA_FEATURE_ASYNC_DESTROY];
1856 objset_t *os;
1857
1858 /*
1859 * There's no next snapshot, so this is a head dataset.
1860 * Destroy the deadlist. Unless it's a clone, the
1861 * deadlist should be empty. (If it's a clone, it's
1862 * safe to ignore the deadlist contents.)
1863 */
1864 dsl_deadlist_close(&ds->ds_deadlist);
1865 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx);
1866 ds->ds_phys->ds_deadlist_obj = 0;
1867
1868 VERIFY3U(0, ==, dmu_objset_from_ds(ds, &os));
1869
1870 if (!spa_feature_is_enabled(dp->dp_spa, async_destroy)) {
1871 err = old_synchronous_dataset_destroy(ds, tx);
1872 } else {
1873 /*
1874 * Move the bptree into the pool's list of trees to
1875 * clean up and update space accounting information.
1876 */
1877 uint64_t used, comp, uncomp;
1878
1879 zil_destroy_sync(dmu_objset_zil(os), tx);
1880
1881 if (!spa_feature_is_active(dp->dp_spa, async_destroy)) {
1882 spa_feature_incr(dp->dp_spa, async_destroy, tx);
1883 dp->dp_bptree_obj = bptree_alloc(mos, tx);
1884 VERIFY(zap_add(mos,
1885 DMU_POOL_DIRECTORY_OBJECT,
1886 DMU_POOL_BPTREE_OBJ, sizeof (uint64_t), 1,
1887 &dp->dp_bptree_obj, tx) == 0);
1888 }
1889
1890 used = ds->ds_dir->dd_phys->dd_used_bytes;
1891 comp = ds->ds_dir->dd_phys->dd_compressed_bytes;
1892 uncomp = ds->ds_dir->dd_phys->dd_uncompressed_bytes;
1893
1894 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) ||
1895 ds->ds_phys->ds_unique_bytes == used);
1896
1897 bptree_add(mos, dp->dp_bptree_obj,
1898 &ds->ds_phys->ds_bp, ds->ds_phys->ds_prev_snap_txg,
1899 used, comp, uncomp, tx);
1900 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
1901 -used, -comp, -uncomp, tx);
1902 dsl_dir_diduse_space(dp->dp_free_dir, DD_USED_HEAD,
1903 used, comp, uncomp, tx);
1904 }
1905
1906 if (ds->ds_prev != NULL) {
1907 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
1908 VERIFY3U(0, ==, zap_remove_int(mos,
1909 ds->ds_prev->ds_dir->dd_phys->dd_clones,
1910 ds->ds_object, tx));
1911 }
1912 dsl_dataset_rele(ds->ds_prev, ds);
1913 ds->ds_prev = ds_prev = NULL;
1914 }
1915 }
1916
1917 /*
1918 * This must be done after the dsl_traverse(), because it will
1919 * re-open the objset.
1920 */
1921 if (ds->ds_objset) {
1922 dmu_objset_evict(ds->ds_objset);
1923 ds->ds_objset = NULL;
1924 }
1925
1926 if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) {
1927 /* Erase the link in the dir */
1928 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx);
1929 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0;
1930 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0);
1931 err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx);
1932 ASSERT(err == 0);
1933 } else {
1934 /* remove from snapshot namespace */
1935 dsl_dataset_t *ds_head;
1936 ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0);
1937 VERIFY(0 == dsl_dataset_hold_obj(dp,
1938 ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head));
1939 VERIFY(0 == dsl_dataset_get_snapname(ds));
1940 #ifdef ZFS_DEBUG
1941 {
1942 uint64_t val;
1943
1944 err = dsl_dataset_snap_lookup(ds_head,
1945 ds->ds_snapname, &val);
1946 ASSERT0(err);
1947 ASSERT3U(val, ==, obj);
1948 }
1949 #endif
1950 err = dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx);
1951 ASSERT(err == 0);
1952 dsl_dataset_rele(ds_head, FTAG);
1953 }
1954
1955 if (ds_prev && ds->ds_prev != ds_prev)
1956 dsl_dataset_rele(ds_prev, FTAG);
1957
1958 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx);
1959
1960 if (ds->ds_phys->ds_next_clones_obj != 0) {
1961 uint64_t count;
1962 ASSERT(0 == zap_count(mos,
1963 ds->ds_phys->ds_next_clones_obj, &count) && count == 0);
1964 VERIFY(0 == dmu_object_free(mos,
1965 ds->ds_phys->ds_next_clones_obj, tx));
1966 }
1967 if (ds->ds_phys->ds_props_obj != 0)
1968 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_props_obj, tx));
1969 if (ds->ds_phys->ds_userrefs_obj != 0)
1970 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx));
1971 dsl_dir_close(ds->ds_dir, ds);
1972 ds->ds_dir = NULL;
1973 dsl_dataset_drain_refs(ds, tag);
1974 VERIFY(0 == dmu_object_free(mos, obj, tx));
1975
1976 if (dsda->rm_origin) {
1977 /*
1978 * Remove the origin of the clone we just destroyed.
1979 */
1980 struct dsl_ds_destroyarg ndsda = {0};
1981
1982 ndsda.ds = dsda->rm_origin;
1983 dsl_dataset_destroy_sync(&ndsda, tag, tx);
1984 }
1985 }
1986
1987 static int
1988 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx)
1989 {
1990 uint64_t asize;
1991
1992 if (!dmu_tx_is_syncing(tx))
1993 return (0);
1994
1995 /*
1996 * If there's an fs-only reservation, any blocks that might become
1997 * owned by the snapshot dataset must be accommodated by space
1998 * outside of the reservation.
1999 */
2000 ASSERT(ds->ds_reserved == 0 || DS_UNIQUE_IS_ACCURATE(ds));
2001 asize = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
2002 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
2003 return (ENOSPC);
2004
2005 /*
2006 * Propagate any reserved space for this snapshot to other
2007 * snapshot checks in this sync group.
2008 */
2009 if (asize > 0)
2010 dsl_dir_willuse_space(ds->ds_dir, asize, tx);
2011
2012 return (0);
2013 }
2014
2015 int
2016 dsl_dataset_snapshot_check(dsl_dataset_t *ds, const char *snapname,
2017 dmu_tx_t *tx)
2018 {
2019 int err;
2020 uint64_t value;
2021
2022 /*
2023 * We don't allow multiple snapshots of the same txg. If there
2024 * is already one, try again.
2025 */
2026 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg)
2027 return (EAGAIN);
2028
2029 /*
2030 * Check for conflicting snapshot name.
2031 */
2032 err = dsl_dataset_snap_lookup(ds, snapname, &value);
2033 if (err == 0)
2034 return (EEXIST);
2035 if (err != ENOENT)
2036 return (err);
2037
2038 /*
2039 * Check that the dataset's name is not too long. Name consists
2040 * of the dataset's length + 1 for the @-sign + snapshot name's length
2041 */
2042 if (dsl_dataset_namelen(ds) + 1 + strlen(snapname) >= MAXNAMELEN)
2043 return (ENAMETOOLONG);
2044
2045 err = dsl_dataset_snapshot_reserve_space(ds, tx);
2046 if (err)
2047 return (err);
2048
2049 ds->ds_trysnap_txg = tx->tx_txg;
2050 return (0);
2051 }
2052
2053 void
2054 dsl_dataset_snapshot_sync(dsl_dataset_t *ds, const char *snapname,
2055 dmu_tx_t *tx)
2056 {
2057 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2058 dmu_buf_t *dbuf;
2059 dsl_dataset_phys_t *dsphys;
2060 uint64_t dsobj, crtxg;
2061 objset_t *mos = dp->dp_meta_objset;
2062 int err;
2063
2064 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
2065
2066 /*
2067 * The origin's ds_creation_txg has to be < TXG_INITIAL
2068 */
2069 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0)
2070 crtxg = 1;
2071 else
2072 crtxg = tx->tx_txg;
2073
2074 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
2075 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
2076 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
2077 dmu_buf_will_dirty(dbuf, tx);
2078 dsphys = dbuf->db_data;
2079 bzero(dsphys, sizeof (dsl_dataset_phys_t));
2080 dsphys->ds_dir_obj = ds->ds_dir->dd_object;
2081 dsphys->ds_fsid_guid = unique_create();
2082 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
2083 sizeof (dsphys->ds_guid));
2084 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj;
2085 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg;
2086 dsphys->ds_next_snap_obj = ds->ds_object;
2087 dsphys->ds_num_children = 1;
2088 dsphys->ds_creation_time = gethrestime_sec();
2089 dsphys->ds_creation_txg = crtxg;
2090 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj;
2091 dsphys->ds_referenced_bytes = ds->ds_phys->ds_referenced_bytes;
2092 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes;
2093 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes;
2094 dsphys->ds_flags = ds->ds_phys->ds_flags;
2095 dsphys->ds_bp = ds->ds_phys->ds_bp;
2096 dmu_buf_rele(dbuf, FTAG);
2097
2098 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0);
2099 if (ds->ds_prev) {
2100 uint64_t next_clones_obj =
2101 ds->ds_prev->ds_phys->ds_next_clones_obj;
2102 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj ==
2103 ds->ds_object ||
2104 ds->ds_prev->ds_phys->ds_num_children > 1);
2105 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) {
2106 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
2107 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
2108 ds->ds_prev->ds_phys->ds_creation_txg);
2109 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj;
2110 } else if (next_clones_obj != 0) {
2111 remove_from_next_clones(ds->ds_prev,
2112 dsphys->ds_next_snap_obj, tx);
2113 VERIFY3U(0, ==, zap_add_int(mos,
2114 next_clones_obj, dsobj, tx));
2115 }
2116 }
2117
2118 /*
2119 * If we have a reference-reservation on this dataset, we will
2120 * need to increase the amount of refreservation being charged
2121 * since our unique space is going to zero.
2122 */
2123 if (ds->ds_reserved) {
2124 int64_t delta;
2125 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
2126 delta = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
2127 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV,
2128 delta, 0, 0, tx);
2129 }
2130
2131 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2132 zfs_dbgmsg("taking snapshot %s@%s/%llu; newkey=%llu",
2133 ds->ds_dir->dd_myname, snapname, dsobj,
2134 ds->ds_phys->ds_prev_snap_txg);
2135 ds->ds_phys->ds_deadlist_obj = dsl_deadlist_clone(&ds->ds_deadlist,
2136 UINT64_MAX, ds->ds_phys->ds_prev_snap_obj, tx);
2137 dsl_deadlist_close(&ds->ds_deadlist);
2138 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj);
2139 dsl_deadlist_add_key(&ds->ds_deadlist,
2140 ds->ds_phys->ds_prev_snap_txg, tx);
2141
2142 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg);
2143 ds->ds_phys->ds_prev_snap_obj = dsobj;
2144 ds->ds_phys->ds_prev_snap_txg = crtxg;
2145 ds->ds_phys->ds_unique_bytes = 0;
2146 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
2147 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
2148
2149 err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj,
2150 snapname, 8, 1, &dsobj, tx);
2151 ASSERT(err == 0);
2152
2153 if (ds->ds_prev)
2154 dsl_dataset_drop_ref(ds->ds_prev, ds);
2155 VERIFY(0 == dsl_dataset_get_ref(dp,
2156 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev));
2157
2158 dsl_scan_ds_snapshotted(ds, tx);
2159
2160 dsl_dir_snap_cmtime_update(ds->ds_dir);
2161
2162 spa_history_log_internal_ds(ds->ds_prev, "snapshot", tx, "");
2163 }
2164
2165 void
2166 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx)
2167 {
2168 ASSERT(dmu_tx_is_syncing(tx));
2169 ASSERT(ds->ds_objset != NULL);
2170 ASSERT(ds->ds_phys->ds_next_snap_obj == 0);
2171
2172 /*
2173 * in case we had to change ds_fsid_guid when we opened it,
2174 * sync it out now.
2175 */
2176 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2177 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid;
2178
2179 dmu_objset_sync(ds->ds_objset, zio, tx);
2180 }
2181
2182 static void
2183 get_clones_stat(dsl_dataset_t *ds, nvlist_t *nv)
2184 {
2185 uint64_t count = 0;
2186 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
2187 zap_cursor_t zc;
2188 zap_attribute_t za;
2189 nvlist_t *propval;
2190 nvlist_t *val;
2191
2192 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER);
2193 VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2194 VERIFY(nvlist_alloc(&val, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2195
2196 /*
2197 * There may me missing entries in ds_next_clones_obj
2198 * due to a bug in a previous version of the code.
2199 * Only trust it if it has the right number of entries.
2200 */
2201 if (ds->ds_phys->ds_next_clones_obj != 0) {
2202 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj,
2203 &count));
2204 }
2205 if (count != ds->ds_phys->ds_num_children - 1) {
2206 goto fail;
2207 }
2208 for (zap_cursor_init(&zc, mos, ds->ds_phys->ds_next_clones_obj);
2209 zap_cursor_retrieve(&zc, &za) == 0;
2210 zap_cursor_advance(&zc)) {
2211 dsl_dataset_t *clone;
2212 char buf[ZFS_MAXNAMELEN];
2213 /*
2214 * Even though we hold the dp_config_rwlock, the dataset
2215 * may fail to open, returning ENOENT. If there is a
2216 * thread concurrently attempting to destroy this
2217 * dataset, it will have the ds_rwlock held for
2218 * RW_WRITER. Our call to dsl_dataset_hold_obj() ->
2219 * dsl_dataset_hold_ref() will fail its
2220 * rw_tryenter(&ds->ds_rwlock, RW_READER), drop the
2221 * dp_config_rwlock, and wait for the destroy progress
2222 * and signal ds_exclusive_cv. If the destroy was
2223 * successful, we will see that
2224 * DSL_DATASET_IS_DESTROYED(), and return ENOENT.
2225 */
2226 if (dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
2227 za.za_first_integer, FTAG, &clone) != 0)
2228 continue;
2229 dsl_dir_name(clone->ds_dir, buf);
2230 VERIFY(nvlist_add_boolean(val, buf) == 0);
2231 dsl_dataset_rele(clone, FTAG);
2232 }
2233 zap_cursor_fini(&zc);
2234 VERIFY(nvlist_add_nvlist(propval, ZPROP_VALUE, val) == 0);
2235 VERIFY(nvlist_add_nvlist(nv, zfs_prop_to_name(ZFS_PROP_CLONES),
2236 propval) == 0);
2237 fail:
2238 nvlist_free(val);
2239 nvlist_free(propval);
2240 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock);
2241 }
2242
2243 void
2244 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv)
2245 {
2246 uint64_t refd, avail, uobjs, aobjs, ratio;
2247
2248 ratio = ds->ds_phys->ds_compressed_bytes == 0 ? 100 :
2249 (ds->ds_phys->ds_uncompressed_bytes * 100 /
2250 ds->ds_phys->ds_compressed_bytes);
2251
2252 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRATIO, ratio);
2253
2254 if (dsl_dataset_is_snapshot(ds)) {
2255 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, ratio);
2256 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED,
2257 ds->ds_phys->ds_unique_bytes);
2258 get_clones_stat(ds, nv);
2259 } else {
2260 dsl_dir_stats(ds->ds_dir, nv);
2261 }
2262
2263 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs);
2264 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail);
2265 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd);
2266
2267 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION,
2268 ds->ds_phys->ds_creation_time);
2269 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG,
2270 ds->ds_phys->ds_creation_txg);
2271 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA,
2272 ds->ds_quota);
2273 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION,
2274 ds->ds_reserved);
2275 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID,
2276 ds->ds_phys->ds_guid);
2277 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE,
2278 ds->ds_phys->ds_unique_bytes);
2279 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID,
2280 ds->ds_object);
2281 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS,
2282 ds->ds_userrefs);
2283 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY,
2284 DS_IS_DEFER_DESTROY(ds) ? 1 : 0);
2285
2286 if (ds->ds_phys->ds_prev_snap_obj != 0) {
2287 uint64_t written, comp, uncomp;
2288 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2289 dsl_dataset_t *prev;
2290
2291 rw_enter(&dp->dp_config_rwlock, RW_READER);
2292 int err = dsl_dataset_hold_obj(dp,
2293 ds->ds_phys->ds_prev_snap_obj, FTAG, &prev);
2294 rw_exit(&dp->dp_config_rwlock);
2295 if (err == 0) {
2296 err = dsl_dataset_space_written(prev, ds, &written,
2297 &comp, &uncomp);
2298 dsl_dataset_rele(prev, FTAG);
2299 if (err == 0) {
2300 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_WRITTEN,
2301 written);
2302 }
2303 }
2304 }
2305 }
2306
2307 void
2308 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat)
2309 {
2310 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg;
2311 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT;
2312 stat->dds_guid = ds->ds_phys->ds_guid;
2313 stat->dds_origin[0] = '\0';
2314 if (dsl_dataset_is_snapshot(ds)) {
2315 stat->dds_is_snapshot = B_TRUE;
2316 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1;
2317 } else {
2318 stat->dds_is_snapshot = B_FALSE;
2319 stat->dds_num_clones = 0;
2320
2321 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER);
2322 if (dsl_dir_is_clone(ds->ds_dir)) {
2323 dsl_dataset_t *ods;
2324
2325 VERIFY(0 == dsl_dataset_get_ref(ds->ds_dir->dd_pool,
2326 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods));
2327 dsl_dataset_name(ods, stat->dds_origin);
2328 dsl_dataset_drop_ref(ods, FTAG);
2329 }
2330 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock);
2331 }
2332 }
2333
2334 uint64_t
2335 dsl_dataset_fsid_guid(dsl_dataset_t *ds)
2336 {
2337 return (ds->ds_fsid_guid);
2338 }
2339
2340 void
2341 dsl_dataset_space(dsl_dataset_t *ds,
2342 uint64_t *refdbytesp, uint64_t *availbytesp,
2343 uint64_t *usedobjsp, uint64_t *availobjsp)
2344 {
2345 *refdbytesp = ds->ds_phys->ds_referenced_bytes;
2346 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE);
2347 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes)
2348 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes;
2349 if (ds->ds_quota != 0) {
2350 /*
2351 * Adjust available bytes according to refquota
2352 */
2353 if (*refdbytesp < ds->ds_quota)
2354 *availbytesp = MIN(*availbytesp,
2355 ds->ds_quota - *refdbytesp);
2356 else
2357 *availbytesp = 0;
2358 }
2359 *usedobjsp = ds->ds_phys->ds_bp.blk_fill;
2360 *availobjsp = DN_MAX_OBJECT - *usedobjsp;
2361 }
2362
2363 boolean_t
2364 dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds)
2365 {
2366 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2367
2368 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) ||
2369 dsl_pool_sync_context(dp));
2370 if (ds->ds_prev == NULL)
2371 return (B_FALSE);
2372 if (ds->ds_phys->ds_bp.blk_birth >
2373 ds->ds_prev->ds_phys->ds_creation_txg) {
2374 objset_t *os, *os_prev;
2375 /*
2376 * It may be that only the ZIL differs, because it was
2377 * reset in the head. Don't count that as being
2378 * modified.
2379 */
2380 if (dmu_objset_from_ds(ds, &os) != 0)
2381 return (B_TRUE);
2382 if (dmu_objset_from_ds(ds->ds_prev, &os_prev) != 0)
2383 return (B_TRUE);
2384 return (bcmp(&os->os_phys->os_meta_dnode,
2385 &os_prev->os_phys->os_meta_dnode,
2386 sizeof (os->os_phys->os_meta_dnode)) != 0);
2387 }
2388 return (B_FALSE);
2389 }
2390
2391 /* ARGSUSED */
2392 static int
2393 dsl_dataset_snapshot_rename_check(void *arg1, void *arg2, dmu_tx_t *tx)
2394 {
2395 dsl_dataset_t *ds = arg1;
2396 char *newsnapname = arg2;
2397 dsl_dir_t *dd = ds->ds_dir;
2398 dsl_dataset_t *hds;
2399 uint64_t val;
2400 int err;
2401
2402 err = dsl_dataset_hold_obj(dd->dd_pool,
2403 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds);
2404 if (err)
2405 return (err);
2406
2407 /* new name better not be in use */
2408 err = dsl_dataset_snap_lookup(hds, newsnapname, &val);
2409 dsl_dataset_rele(hds, FTAG);
2410
2411 if (err == 0)
2412 err = EEXIST;
2413 else if (err == ENOENT)
2414 err = 0;
2415
2416 /* dataset name + 1 for the "@" + the new snapshot name must fit */
2417 if (dsl_dir_namelen(ds->ds_dir) + 1 + strlen(newsnapname) >= MAXNAMELEN)
2418 err = ENAMETOOLONG;
2419
2420 return (err);
2421 }
2422
2423 static void
2424 dsl_dataset_snapshot_rename_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2425 {
2426 dsl_dataset_t *ds = arg1;
2427 const char *newsnapname = arg2;
2428 dsl_dir_t *dd = ds->ds_dir;
2429 objset_t *mos = dd->dd_pool->dp_meta_objset;
2430 dsl_dataset_t *hds;
2431 int err;
2432
2433 ASSERT(ds->ds_phys->ds_next_snap_obj != 0);
2434
2435 VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool,
2436 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds));
2437
2438 VERIFY(0 == dsl_dataset_get_snapname(ds));
2439 err = dsl_dataset_snap_remove(hds, ds->ds_snapname, tx);
2440 ASSERT0(err);
2441 mutex_enter(&ds->ds_lock);
2442 (void) strcpy(ds->ds_snapname, newsnapname);
2443 mutex_exit(&ds->ds_lock);
2444 err = zap_add(mos, hds->ds_phys->ds_snapnames_zapobj,
2445 ds->ds_snapname, 8, 1, &ds->ds_object, tx);
2446 ASSERT0(err);
2447
2448 spa_history_log_internal_ds(ds, "rename", tx,
2449 "-> @%s", newsnapname);
2450 dsl_dataset_rele(hds, FTAG);
2451 }
2452
2453 struct renamesnaparg {
2454 dsl_sync_task_group_t *dstg;
2455 char failed[MAXPATHLEN];
2456 char *oldsnap;
2457 char *newsnap;
2458 };
2459
2460 static int
2461 dsl_snapshot_rename_one(const char *name, void *arg)
2462 {
2463 struct renamesnaparg *ra = arg;
2464 dsl_dataset_t *ds = NULL;
2465 char *snapname;
2466 int err;
2467
2468 snapname = kmem_asprintf("%s@%s", name, ra->oldsnap);
2469 (void) strlcpy(ra->failed, snapname, sizeof (ra->failed));
2470
2471 /*
2472 * For recursive snapshot renames the parent won't be changing
2473 * so we just pass name for both the to/from argument.
2474 */
2475 err = zfs_secpolicy_rename_perms(snapname, snapname, CRED());
2476 if (err != 0) {
2477 strfree(snapname);
2478 return (err == ENOENT ? 0 : err);
2479 }
2480
2481 #ifdef _KERNEL
2482 /*
2483 * For all filesystems undergoing rename, we'll need to unmount it.
2484 */
2485 (void) zfs_unmount_snap(snapname, NULL);
2486 #endif
2487 err = dsl_dataset_hold(snapname, ra->dstg, &ds);
2488 strfree(snapname);
2489 if (err != 0)
2490 return (err == ENOENT ? 0 : err);
2491
2492 dsl_sync_task_create(ra->dstg, dsl_dataset_snapshot_rename_check,
2493 dsl_dataset_snapshot_rename_sync, ds, ra->newsnap, 0);
2494
2495 return (0);
2496 }
2497
2498 static int
2499 dsl_recursive_rename(char *oldname, const char *newname)
2500 {
2501 int err;
2502 struct renamesnaparg *ra;
2503 dsl_sync_task_t *dst;
2504 spa_t *spa;
2505 char *cp, *fsname = spa_strdup(oldname);
2506 int len = strlen(oldname) + 1;
2507
2508 /* truncate the snapshot name to get the fsname */
2509 cp = strchr(fsname, '@');
2510 *cp = '\0';
2511
2512 err = spa_open(fsname, &spa, FTAG);
2513 if (err) {
2514 kmem_free(fsname, len);
2515 return (err);
2516 }
2517 ra = kmem_alloc(sizeof (struct renamesnaparg), KM_SLEEP);
2518 ra->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
2519
2520 ra->oldsnap = strchr(oldname, '@') + 1;
2521 ra->newsnap = strchr(newname, '@') + 1;
2522 *ra->failed = '\0';
2523
2524 err = dmu_objset_find(fsname, dsl_snapshot_rename_one, ra,
2525 DS_FIND_CHILDREN);
2526 kmem_free(fsname, len);
2527
2528 if (err == 0) {
2529 err = dsl_sync_task_group_wait(ra->dstg);
2530 }
2531
2532 for (dst = list_head(&ra->dstg->dstg_tasks); dst;
2533 dst = list_next(&ra->dstg->dstg_tasks, dst)) {
2534 dsl_dataset_t *ds = dst->dst_arg1;
2535 if (dst->dst_err) {
2536 dsl_dir_name(ds->ds_dir, ra->failed);
2537 (void) strlcat(ra->failed, "@", sizeof (ra->failed));
2538 (void) strlcat(ra->failed, ra->newsnap,
2539 sizeof (ra->failed));
2540 }
2541 dsl_dataset_rele(ds, ra->dstg);
2542 }
2543
2544 if (err)
2545 (void) strlcpy(oldname, ra->failed, sizeof (ra->failed));
2546
2547 dsl_sync_task_group_destroy(ra->dstg);
2548 kmem_free(ra, sizeof (struct renamesnaparg));
2549 spa_close(spa, FTAG);
2550 return (err);
2551 }
2552
2553 static int
2554 dsl_valid_rename(const char *oldname, void *arg)
2555 {
2556 int delta = *(int *)arg;
2557
2558 if (strlen(oldname) + delta >= MAXNAMELEN)
2559 return (ENAMETOOLONG);
2560
2561 return (0);
2562 }
2563
2564 #pragma weak dmu_objset_rename = dsl_dataset_rename
2565 int
2566 dsl_dataset_rename(char *oldname, const char *newname, boolean_t recursive)
2567 {
2568 dsl_dir_t *dd;
2569 dsl_dataset_t *ds;
2570 const char *tail;
2571 int err;
2572
2573 err = dsl_dir_open(oldname, FTAG, &dd, &tail);
2574 if (err)
2575 return (err);
2576
2577 if (tail == NULL) {
2578 int delta = strlen(newname) - strlen(oldname);
2579
2580 /* if we're growing, validate child name lengths */
2581 if (delta > 0)
2582 err = dmu_objset_find(oldname, dsl_valid_rename,
2583 &delta, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS);
2584
2585 if (err == 0)
2586 err = dsl_dir_rename(dd, newname);
2587 dsl_dir_close(dd, FTAG);
2588 return (err);
2589 }
2590
2591 if (tail[0] != '@') {
2592 /* the name ended in a nonexistent component */
2593 dsl_dir_close(dd, FTAG);
2594 return (ENOENT);
2595 }
2596
2597 dsl_dir_close(dd, FTAG);
2598
2599 /* new name must be snapshot in same filesystem */
2600 tail = strchr(newname, '@');
2601 if (tail == NULL)
2602 return (EINVAL);
2603 tail++;
2604 if (strncmp(oldname, newname, tail - newname) != 0)
2605 return (EXDEV);
2606
2607 if (recursive) {
2608 err = dsl_recursive_rename(oldname, newname);
2609 } else {
2610 err = dsl_dataset_hold(oldname, FTAG, &ds);
2611 if (err)
2612 return (err);
2613
2614 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
2615 dsl_dataset_snapshot_rename_check,
2616 dsl_dataset_snapshot_rename_sync, ds, (char *)tail, 1);
2617
2618 dsl_dataset_rele(ds, FTAG);
2619 }
2620
2621 return (err);
2622 }
2623
2624 struct promotenode {
2625 list_node_t link;
2626 dsl_dataset_t *ds;
2627 };
2628
2629 struct promotearg {
2630 list_t shared_snaps, origin_snaps, clone_snaps;
2631 dsl_dataset_t *origin_origin;
2632 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap;
2633 char *err_ds;
2634 };
2635
2636 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep);
2637 static boolean_t snaplist_unstable(list_t *l);
2638
2639 static int
2640 dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx)
2641 {
2642 dsl_dataset_t *hds = arg1;
2643 struct promotearg *pa = arg2;
2644 struct promotenode *snap = list_head(&pa->shared_snaps);
2645 dsl_dataset_t *origin_ds = snap->ds;
2646 int err;
2647 uint64_t unused;
2648
2649 /* Check that it is a real clone */
2650 if (!dsl_dir_is_clone(hds->ds_dir))
2651 return (EINVAL);
2652
2653 /* Since this is so expensive, don't do the preliminary check */
2654 if (!dmu_tx_is_syncing(tx))
2655 return (0);
2656
2657 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE)
2658 return (EXDEV);
2659
2660 /* compute origin's new unique space */
2661 snap = list_tail(&pa->clone_snaps);
2662 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2663 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2664 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX,
2665 &pa->unique, &unused, &unused);
2666
2667 /*
2668 * Walk the snapshots that we are moving
2669 *
2670 * Compute space to transfer. Consider the incremental changes
2671 * to used for each snapshot:
2672 * (my used) = (prev's used) + (blocks born) - (blocks killed)
2673 * So each snapshot gave birth to:
2674 * (blocks born) = (my used) - (prev's used) + (blocks killed)
2675 * So a sequence would look like:
2676 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0)
2677 * Which simplifies to:
2678 * uN + kN + kN-1 + ... + k1 + k0
2679 * Note however, if we stop before we reach the ORIGIN we get:
2680 * uN + kN + kN-1 + ... + kM - uM-1
2681 */
2682 pa->used = origin_ds->ds_phys->ds_referenced_bytes;
2683 pa->comp = origin_ds->ds_phys->ds_compressed_bytes;
2684 pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes;
2685 for (snap = list_head(&pa->shared_snaps); snap;
2686 snap = list_next(&pa->shared_snaps, snap)) {
2687 uint64_t val, dlused, dlcomp, dluncomp;
2688 dsl_dataset_t *ds = snap->ds;
2689
2690 /* Check that the snapshot name does not conflict */
2691 VERIFY(0 == dsl_dataset_get_snapname(ds));
2692 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val);
2693 if (err == 0) {
2694 err = EEXIST;
2695 goto out;
2696 }
2697 if (err != ENOENT)
2698 goto out;
2699
2700 /* The very first snapshot does not have a deadlist */
2701 if (ds->ds_phys->ds_prev_snap_obj == 0)
2702 continue;
2703
2704 dsl_deadlist_space(&ds->ds_deadlist,
2705 &dlused, &dlcomp, &dluncomp);
2706 pa->used += dlused;
2707 pa->comp += dlcomp;
2708 pa->uncomp += dluncomp;
2709 }
2710
2711 /*
2712 * If we are a clone of a clone then we never reached ORIGIN,
2713 * so we need to subtract out the clone origin's used space.
2714 */
2715 if (pa->origin_origin) {
2716 pa->used -= pa->origin_origin->ds_phys->ds_referenced_bytes;
2717 pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes;
2718 pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes;
2719 }
2720
2721 /* Check that there is enough space here */
2722 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir,
2723 pa->used);
2724 if (err)
2725 return (err);
2726
2727 /*
2728 * Compute the amounts of space that will be used by snapshots
2729 * after the promotion (for both origin and clone). For each,
2730 * it is the amount of space that will be on all of their
2731 * deadlists (that was not born before their new origin).
2732 */
2733 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2734 uint64_t space;
2735
2736 /*
2737 * Note, typically this will not be a clone of a clone,
2738 * so dd_origin_txg will be < TXG_INITIAL, so
2739 * these snaplist_space() -> dsl_deadlist_space_range()
2740 * calls will be fast because they do not have to
2741 * iterate over all bps.
2742 */
2743 snap = list_head(&pa->origin_snaps);
2744 err = snaplist_space(&pa->shared_snaps,
2745 snap->ds->ds_dir->dd_origin_txg, &pa->cloneusedsnap);
2746 if (err)
2747 return (err);
2748
2749 err = snaplist_space(&pa->clone_snaps,
2750 snap->ds->ds_dir->dd_origin_txg, &space);
2751 if (err)
2752 return (err);
2753 pa->cloneusedsnap += space;
2754 }
2755 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2756 err = snaplist_space(&pa->origin_snaps,
2757 origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap);
2758 if (err)
2759 return (err);
2760 }
2761
2762 return (0);
2763 out:
2764 pa->err_ds = snap->ds->ds_snapname;
2765 return (err);
2766 }
2767
2768 static void
2769 dsl_dataset_promote_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2770 {
2771 dsl_dataset_t *hds = arg1;
2772 struct promotearg *pa = arg2;
2773 struct promotenode *snap = list_head(&pa->shared_snaps);
2774 dsl_dataset_t *origin_ds = snap->ds;
2775 dsl_dataset_t *origin_head;
2776 dsl_dir_t *dd = hds->ds_dir;
2777 dsl_pool_t *dp = hds->ds_dir->dd_pool;
2778 dsl_dir_t *odd = NULL;
2779 uint64_t oldnext_obj;
2780 int64_t delta;
2781
2782 ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE));
2783
2784 snap = list_head(&pa->origin_snaps);
2785 origin_head = snap->ds;
2786
2787 /*
2788 * We need to explicitly open odd, since origin_ds's dd will be
2789 * changing.
2790 */
2791 VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object,
2792 NULL, FTAG, &odd));
2793
2794 /* change origin's next snap */
2795 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx);
2796 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj;
2797 snap = list_tail(&pa->clone_snaps);
2798 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2799 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object;
2800
2801 /* change the origin's next clone */
2802 if (origin_ds->ds_phys->ds_next_clones_obj) {
2803 remove_from_next_clones(origin_ds, snap->ds->ds_object, tx);
2804 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2805 origin_ds->ds_phys->ds_next_clones_obj,
2806 oldnext_obj, tx));
2807 }
2808
2809 /* change origin */
2810 dmu_buf_will_dirty(dd->dd_dbuf, tx);
2811 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object);
2812 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj;
2813 dd->dd_origin_txg = origin_head->ds_dir->dd_origin_txg;
2814 dmu_buf_will_dirty(odd->dd_dbuf, tx);
2815 odd->dd_phys->dd_origin_obj = origin_ds->ds_object;
2816 origin_head->ds_dir->dd_origin_txg =
2817 origin_ds->ds_phys->ds_creation_txg;
2818
2819 /* change dd_clone entries */
2820 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2821 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
2822 odd->dd_phys->dd_clones, hds->ds_object, tx));
2823 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2824 pa->origin_origin->ds_dir->dd_phys->dd_clones,
2825 hds->ds_object, tx));
2826
2827 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
2828 pa->origin_origin->ds_dir->dd_phys->dd_clones,
2829 origin_head->ds_object, tx));
2830 if (dd->dd_phys->dd_clones == 0) {
2831 dd->dd_phys->dd_clones = zap_create(dp->dp_meta_objset,
2832 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
2833 }
2834 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2835 dd->dd_phys->dd_clones, origin_head->ds_object, tx));
2836
2837 }
2838
2839 /* move snapshots to this dir */
2840 for (snap = list_head(&pa->shared_snaps); snap;
2841 snap = list_next(&pa->shared_snaps, snap)) {
2842 dsl_dataset_t *ds = snap->ds;
2843
2844 /* unregister props as dsl_dir is changing */
2845 if (ds->ds_objset) {
2846 dmu_objset_evict(ds->ds_objset);
2847 ds->ds_objset = NULL;
2848 }
2849 /* move snap name entry */
2850 VERIFY(0 == dsl_dataset_get_snapname(ds));
2851 VERIFY(0 == dsl_dataset_snap_remove(origin_head,
2852 ds->ds_snapname, tx));
2853 VERIFY(0 == zap_add(dp->dp_meta_objset,
2854 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname,
2855 8, 1, &ds->ds_object, tx));
2856
2857 /* change containing dsl_dir */
2858 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2859 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object);
2860 ds->ds_phys->ds_dir_obj = dd->dd_object;
2861 ASSERT3P(ds->ds_dir, ==, odd);
2862 dsl_dir_close(ds->ds_dir, ds);
2863 VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object,
2864 NULL, ds, &ds->ds_dir));
2865
2866 /* move any clone references */
2867 if (ds->ds_phys->ds_next_clones_obj &&
2868 spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2869 zap_cursor_t zc;
2870 zap_attribute_t za;
2871
2872 for (zap_cursor_init(&zc, dp->dp_meta_objset,
2873 ds->ds_phys->ds_next_clones_obj);
2874 zap_cursor_retrieve(&zc, &za) == 0;
2875 zap_cursor_advance(&zc)) {
2876 dsl_dataset_t *cnds;
2877 uint64_t o;
2878
2879 if (za.za_first_integer == oldnext_obj) {
2880 /*
2881 * We've already moved the
2882 * origin's reference.
2883 */
2884 continue;
2885 }
2886
2887 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
2888 za.za_first_integer, FTAG, &cnds));
2889 o = cnds->ds_dir->dd_phys->dd_head_dataset_obj;
2890
2891 VERIFY3U(zap_remove_int(dp->dp_meta_objset,
2892 odd->dd_phys->dd_clones, o, tx), ==, 0);
2893 VERIFY3U(zap_add_int(dp->dp_meta_objset,
2894 dd->dd_phys->dd_clones, o, tx), ==, 0);
2895 dsl_dataset_rele(cnds, FTAG);
2896 }
2897 zap_cursor_fini(&zc);
2898 }
2899
2900 ASSERT0(dsl_prop_numcb(ds));
2901 }
2902
2903 /*
2904 * Change space accounting.
2905 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either
2906 * both be valid, or both be 0 (resulting in delta == 0). This
2907 * is true for each of {clone,origin} independently.
2908 */
2909
2910 delta = pa->cloneusedsnap -
2911 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2912 ASSERT3S(delta, >=, 0);
2913 ASSERT3U(pa->used, >=, delta);
2914 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx);
2915 dsl_dir_diduse_space(dd, DD_USED_HEAD,
2916 pa->used - delta, pa->comp, pa->uncomp, tx);
2917
2918 delta = pa->originusedsnap -
2919 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2920 ASSERT3S(delta, <=, 0);
2921 ASSERT3U(pa->used, >=, -delta);
2922 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx);
2923 dsl_dir_diduse_space(odd, DD_USED_HEAD,
2924 -pa->used - delta, -pa->comp, -pa->uncomp, tx);
2925
2926 origin_ds->ds_phys->ds_unique_bytes = pa->unique;
2927
2928 /* log history record */
2929 spa_history_log_internal_ds(hds, "promote", tx, "");
2930
2931 dsl_dir_close(odd, FTAG);
2932 }
2933
2934 static char *snaplist_tag = "snaplist";
2935 /*
2936 * Make a list of dsl_dataset_t's for the snapshots between first_obj
2937 * (exclusive) and last_obj (inclusive). The list will be in reverse
2938 * order (last_obj will be the list_head()). If first_obj == 0, do all
2939 * snapshots back to this dataset's origin.
2940 */
2941 static int
2942 snaplist_make(dsl_pool_t *dp, boolean_t own,
2943 uint64_t first_obj, uint64_t last_obj, list_t *l)
2944 {
2945 uint64_t obj = last_obj;
2946
2947 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock));
2948
2949 list_create(l, sizeof (struct promotenode),
2950 offsetof(struct promotenode, link));
2951
2952 while (obj != first_obj) {
2953 dsl_dataset_t *ds;
2954 struct promotenode *snap;
2955 int err;
2956
2957 if (own) {
2958 err = dsl_dataset_own_obj(dp, obj,
2959 0, snaplist_tag, &ds);
2960 if (err == 0)
2961 dsl_dataset_make_exclusive(ds, snaplist_tag);
2962 } else {
2963 err = dsl_dataset_hold_obj(dp, obj, snaplist_tag, &ds);
2964 }
2965 if (err == ENOENT) {
2966 /* lost race with snapshot destroy */
2967 struct promotenode *last = list_tail(l);
2968 ASSERT(obj != last->ds->ds_phys->ds_prev_snap_obj);
2969 obj = last->ds->ds_phys->ds_prev_snap_obj;
2970 continue;
2971 } else if (err) {
2972 return (err);
2973 }
2974
2975 if (first_obj == 0)
2976 first_obj = ds->ds_dir->dd_phys->dd_origin_obj;
2977
2978 snap = kmem_alloc(sizeof (struct promotenode), KM_SLEEP);
2979 snap->ds = ds;
2980 list_insert_tail(l, snap);
2981 obj = ds->ds_phys->ds_prev_snap_obj;
2982 }
2983
2984 return (0);
2985 }
2986
2987 static int
2988 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep)
2989 {
2990 struct promotenode *snap;
2991
2992 *spacep = 0;
2993 for (snap = list_head(l); snap; snap = list_next(l, snap)) {
2994 uint64_t used, comp, uncomp;
2995 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2996 mintxg, UINT64_MAX, &used, &comp, &uncomp);
2997 *spacep += used;
2998 }
2999 return (0);
3000 }
3001
3002 static void
3003 snaplist_destroy(list_t *l, boolean_t own)
3004 {
3005 struct promotenode *snap;
3006
3007 if (!l || !list_link_active(&l->list_head))
3008 return;
3009
3010 while ((snap = list_tail(l)) != NULL) {
3011 list_remove(l, snap);
3012 if (own)
3013 dsl_dataset_disown(snap->ds, snaplist_tag);
3014 else
3015 dsl_dataset_rele(snap->ds, snaplist_tag);
3016 kmem_free(snap, sizeof (struct promotenode));
3017 }
3018 list_destroy(l);
3019 }
3020
3021 /*
3022 * Promote a clone. Nomenclature note:
3023 * "clone" or "cds": the original clone which is being promoted
3024 * "origin" or "ods": the snapshot which is originally clone's origin
3025 * "origin head" or "ohds": the dataset which is the head
3026 * (filesystem/volume) for the origin
3027 * "origin origin": the origin of the origin's filesystem (typically
3028 * NULL, indicating that the clone is not a clone of a clone).
3029 */
3030 int
3031 dsl_dataset_promote(const char *name, char *conflsnap)
3032 {
3033 dsl_dataset_t *ds;
3034 dsl_dir_t *dd;
3035 dsl_pool_t *dp;
3036 dmu_object_info_t doi;
3037 struct promotearg pa = { 0 };
3038 struct promotenode *snap;
3039 int err;
3040
3041 err = dsl_dataset_hold(name, FTAG, &ds);
3042 if (err)
3043 return (err);
3044 dd = ds->ds_dir;
3045 dp = dd->dd_pool;
3046
3047 err = dmu_object_info(dp->dp_meta_objset,
3048 ds->ds_phys->ds_snapnames_zapobj, &doi);
3049 if (err) {
3050 dsl_dataset_rele(ds, FTAG);
3051 return (err);
3052 }
3053
3054 if (dsl_dataset_is_snapshot(ds) || dd->dd_phys->dd_origin_obj == 0) {
3055 dsl_dataset_rele(ds, FTAG);
3056 return (EINVAL);
3057 }
3058
3059 /*
3060 * We are going to inherit all the snapshots taken before our
3061 * origin (i.e., our new origin will be our parent's origin).
3062 * Take ownership of them so that we can rename them into our
3063 * namespace.
3064 */
3065 rw_enter(&dp->dp_config_rwlock, RW_READER);
3066
3067 err = snaplist_make(dp, B_TRUE, 0, dd->dd_phys->dd_origin_obj,
3068 &pa.shared_snaps);
3069 if (err != 0)
3070 goto out;
3071
3072 err = snaplist_make(dp, B_FALSE, 0, ds->ds_object, &pa.clone_snaps);
3073 if (err != 0)
3074 goto out;
3075
3076 snap = list_head(&pa.shared_snaps);
3077 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj);
3078 err = snaplist_make(dp, B_FALSE, dd->dd_phys->dd_origin_obj,
3079 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj, &pa.origin_snaps);
3080 if (err != 0)
3081 goto out;
3082
3083 if (snap->ds->ds_dir->dd_phys->dd_origin_obj != 0) {
3084 err = dsl_dataset_hold_obj(dp,
3085 snap->ds->ds_dir->dd_phys->dd_origin_obj,
3086 FTAG, &pa.origin_origin);
3087 if (err != 0)
3088 goto out;
3089 }
3090
3091 out:
3092 rw_exit(&dp->dp_config_rwlock);
3093
3094 /*
3095 * Add in 128x the snapnames zapobj size, since we will be moving
3096 * a bunch of snapnames to the promoted ds, and dirtying their
3097 * bonus buffers.
3098 */
3099 if (err == 0) {
3100 err = dsl_sync_task_do(dp, dsl_dataset_promote_check,
3101 dsl_dataset_promote_sync, ds, &pa,
3102 2 + 2 * doi.doi_physical_blocks_512);
3103 if (err && pa.err_ds && conflsnap)
3104 (void) strncpy(conflsnap, pa.err_ds, MAXNAMELEN);
3105 }
3106
3107 snaplist_destroy(&pa.shared_snaps, B_TRUE);
3108 snaplist_destroy(&pa.clone_snaps, B_FALSE);
3109 snaplist_destroy(&pa.origin_snaps, B_FALSE);
3110 if (pa.origin_origin)
3111 dsl_dataset_rele(pa.origin_origin, FTAG);
3112 dsl_dataset_rele(ds, FTAG);
3113 return (err);
3114 }
3115
3116 struct cloneswaparg {
3117 dsl_dataset_t *cds; /* clone dataset */
3118 dsl_dataset_t *ohds; /* origin's head dataset */
3119 boolean_t force;
3120 int64_t unused_refres_delta; /* change in unconsumed refreservation */
3121 };
3122
3123 /* ARGSUSED */
3124 static int
3125 dsl_dataset_clone_swap_check(void *arg1, void *arg2, dmu_tx_t *tx)
3126 {
3127 struct cloneswaparg *csa = arg1;
3128
3129 /* they should both be heads */
3130 if (dsl_dataset_is_snapshot(csa->cds) ||
3131 dsl_dataset_is_snapshot(csa->ohds))
3132 return (EINVAL);
3133
3134 /* the branch point should be just before them */
3135 if (csa->cds->ds_prev != csa->ohds->ds_prev)
3136 return (EINVAL);
3137
3138 /* cds should be the clone (unless they are unrelated) */
3139 if (csa->cds->ds_prev != NULL &&
3140 csa->cds->ds_prev != csa->cds->ds_dir->dd_pool->dp_origin_snap &&
3141 csa->ohds->ds_object !=
3142 csa->cds->ds_prev->ds_phys->ds_next_snap_obj)
3143 return (EINVAL);
3144
3145 /* the clone should be a child of the origin */
3146 if (csa->cds->ds_dir->dd_parent != csa->ohds->ds_dir)
3147 return (EINVAL);
3148
3149 /* ohds shouldn't be modified unless 'force' */
3150 if (!csa->force && dsl_dataset_modified_since_lastsnap(csa->ohds))
3151 return (ETXTBSY);
3152
3153 /* adjust amount of any unconsumed refreservation */
3154 csa->unused_refres_delta =
3155 (int64_t)MIN(csa->ohds->ds_reserved,
3156 csa->ohds->ds_phys->ds_unique_bytes) -
3157 (int64_t)MIN(csa->ohds->ds_reserved,
3158 csa->cds->ds_phys->ds_unique_bytes);
3159
3160 if (csa->unused_refres_delta > 0 &&
3161 csa->unused_refres_delta >
3162 dsl_dir_space_available(csa->ohds->ds_dir, NULL, 0, TRUE))
3163 return (ENOSPC);
3164
3165 if (csa->ohds->ds_quota != 0 &&
3166 csa->cds->ds_phys->ds_unique_bytes > csa->ohds->ds_quota)
3167 return (EDQUOT);
3168
3169 return (0);
3170 }
3171
3172 /* ARGSUSED */
3173 static void
3174 dsl_dataset_clone_swap_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3175 {
3176 struct cloneswaparg *csa = arg1;
3177 dsl_pool_t *dp = csa->cds->ds_dir->dd_pool;
3178
3179 ASSERT(csa->cds->ds_reserved == 0);
3180 ASSERT(csa->ohds->ds_quota == 0 ||
3181 csa->cds->ds_phys->ds_unique_bytes <= csa->ohds->ds_quota);
3182
3183 dmu_buf_will_dirty(csa->cds->ds_dbuf, tx);
3184 dmu_buf_will_dirty(csa->ohds->ds_dbuf, tx);
3185
3186 if (csa->cds->ds_objset != NULL) {
3187 dmu_objset_evict(csa->cds->ds_objset);
3188 csa->cds->ds_objset = NULL;
3189 }
3190
3191 if (csa->ohds->ds_objset != NULL) {
3192 dmu_objset_evict(csa->ohds->ds_objset);
3193 csa->ohds->ds_objset = NULL;
3194 }
3195
3196 /*
3197 * Reset origin's unique bytes, if it exists.
3198 */
3199 if (csa->cds->ds_prev) {
3200 dsl_dataset_t *origin = csa->cds->ds_prev;
3201 uint64_t comp, uncomp;
3202
3203 dmu_buf_will_dirty(origin->ds_dbuf, tx);
3204 dsl_deadlist_space_range(&csa->cds->ds_deadlist,
3205 origin->ds_phys->ds_prev_snap_txg, UINT64_MAX,
3206 &origin->ds_phys->ds_unique_bytes, &comp, &uncomp);
3207 }
3208
3209 /* swap blkptrs */
3210 {
3211 blkptr_t tmp;
3212 tmp = csa->ohds->ds_phys->ds_bp;
3213 csa->ohds->ds_phys->ds_bp = csa->cds->ds_phys->ds_bp;
3214 csa->cds->ds_phys->ds_bp = tmp;
3215 }
3216
3217 /* set dd_*_bytes */
3218 {
3219 int64_t dused, dcomp, duncomp;
3220 uint64_t cdl_used, cdl_comp, cdl_uncomp;
3221 uint64_t odl_used, odl_comp, odl_uncomp;
3222
3223 ASSERT3U(csa->cds->ds_dir->dd_phys->
3224 dd_used_breakdown[DD_USED_SNAP], ==, 0);
3225
3226 dsl_deadlist_space(&csa->cds->ds_deadlist,
3227 &cdl_used, &cdl_comp, &cdl_uncomp);
3228 dsl_deadlist_space(&csa->ohds->ds_deadlist,
3229 &odl_used, &odl_comp, &odl_uncomp);
3230
3231 dused = csa->cds->ds_phys->ds_referenced_bytes + cdl_used -
3232 (csa->ohds->ds_phys->ds_referenced_bytes + odl_used);
3233 dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp -
3234 (csa->ohds->ds_phys->ds_compressed_bytes + odl_comp);
3235 duncomp = csa->cds->ds_phys->ds_uncompressed_bytes +
3236 cdl_uncomp -
3237 (csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp);
3238
3239 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD,
3240 dused, dcomp, duncomp, tx);
3241 dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD,
3242 -dused, -dcomp, -duncomp, tx);
3243
3244 /*
3245 * The difference in the space used by snapshots is the
3246 * difference in snapshot space due to the head's
3247 * deadlist (since that's the only thing that's
3248 * changing that affects the snapused).
3249 */
3250 dsl_deadlist_space_range(&csa->cds->ds_deadlist,
3251 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX,
3252 &cdl_used, &cdl_comp, &cdl_uncomp);
3253 dsl_deadlist_space_range(&csa->ohds->ds_deadlist,
3254 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX,
3255 &odl_used, &odl_comp, &odl_uncomp);
3256 dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used,
3257 DD_USED_HEAD, DD_USED_SNAP, tx);
3258 }
3259
3260 /* swap ds_*_bytes */
3261 SWITCH64(csa->ohds->ds_phys->ds_referenced_bytes,
3262 csa->cds->ds_phys->ds_referenced_bytes);
3263 SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes,
3264 csa->cds->ds_phys->ds_compressed_bytes);
3265 SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes,
3266 csa->cds->ds_phys->ds_uncompressed_bytes);
3267 SWITCH64(csa->ohds->ds_phys->ds_unique_bytes,
3268 csa->cds->ds_phys->ds_unique_bytes);
3269
3270 /* apply any parent delta for change in unconsumed refreservation */
3271 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV,
3272 csa->unused_refres_delta, 0, 0, tx);
3273
3274 /*
3275 * Swap deadlists.
3276 */
3277 dsl_deadlist_close(&csa->cds->ds_deadlist);
3278 dsl_deadlist_close(&csa->ohds->ds_deadlist);
3279 SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj,
3280 csa->cds->ds_phys->ds_deadlist_obj);
3281 dsl_deadlist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset,
3282 csa->cds->ds_phys->ds_deadlist_obj);
3283 dsl_deadlist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset,
3284 csa->ohds->ds_phys->ds_deadlist_obj);
3285
3286 dsl_scan_ds_clone_swapped(csa->ohds, csa->cds, tx);
3287
3288 spa_history_log_internal_ds(csa->cds, "clone swap", tx,
3289 "parent=%s", csa->ohds->ds_dir->dd_myname);
3290 }
3291
3292 /*
3293 * Swap 'clone' with its origin head datasets. Used at the end of "zfs
3294 * recv" into an existing fs to swizzle the file system to the new
3295 * version, and by "zfs rollback". Can also be used to swap two
3296 * independent head datasets if neither has any snapshots.
3297 */
3298 int
3299 dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head,
3300 boolean_t force)
3301 {
3302 struct cloneswaparg csa;
3303 int error;
3304
3305 ASSERT(clone->ds_owner);
3306 ASSERT(origin_head->ds_owner);
3307 retry:
3308 /*
3309 * Need exclusive access for the swap. If we're swapping these
3310 * datasets back after an error, we already hold the locks.
3311 */
3312 if (!RW_WRITE_HELD(&clone->ds_rwlock))
3313 rw_enter(&clone->ds_rwlock, RW_WRITER);
3314 if (!RW_WRITE_HELD(&origin_head->ds_rwlock) &&
3315 !rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) {
3316 rw_exit(&clone->ds_rwlock);
3317 rw_enter(&origin_head->ds_rwlock, RW_WRITER);
3318 if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) {
3319 rw_exit(&origin_head->ds_rwlock);
3320 goto retry;
3321 }
3322 }
3323 csa.cds = clone;
3324 csa.ohds = origin_head;
3325 csa.force = force;
3326 error = dsl_sync_task_do(clone->ds_dir->dd_pool,
3327 dsl_dataset_clone_swap_check,
3328 dsl_dataset_clone_swap_sync, &csa, NULL, 9);
3329 return (error);
3330 }
3331
3332 /*
3333 * Given a pool name and a dataset object number in that pool,
3334 * return the name of that dataset.
3335 */
3336 int
3337 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf)
3338 {
3339 spa_t *spa;
3340 dsl_pool_t *dp;
3341 dsl_dataset_t *ds;
3342 int error;
3343
3344 if ((error = spa_open(pname, &spa, FTAG)) != 0)
3345 return (error);
3346 dp = spa_get_dsl(spa);
3347 rw_enter(&dp->dp_config_rwlock, RW_READER);
3348 if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) {
3349 dsl_dataset_name(ds, buf);
3350 dsl_dataset_rele(ds, FTAG);
3351 }
3352 rw_exit(&dp->dp_config_rwlock);
3353 spa_close(spa, FTAG);
3354
3355 return (error);
3356 }
3357
3358 int
3359 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota,
3360 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv)
3361 {
3362 int error = 0;
3363
3364 ASSERT3S(asize, >, 0);
3365
3366 /*
3367 * *ref_rsrv is the portion of asize that will come from any
3368 * unconsumed refreservation space.
3369 */
3370 *ref_rsrv = 0;
3371
3372 mutex_enter(&ds->ds_lock);
3373 /*
3374 * Make a space adjustment for reserved bytes.
3375 */
3376 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) {
3377 ASSERT3U(*used, >=,
3378 ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
3379 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
3380 *ref_rsrv =
3381 asize - MIN(asize, parent_delta(ds, asize + inflight));
3382 }
3383
3384 if (!check_quota || ds->ds_quota == 0) {
3385 mutex_exit(&ds->ds_lock);
3386 return (0);
3387 }
3388 /*
3389 * If they are requesting more space, and our current estimate
3390 * is over quota, they get to try again unless the actual
3391 * on-disk is over quota and there are no pending changes (which
3392 * may free up space for us).
3393 */
3394 if (ds->ds_phys->ds_referenced_bytes + inflight >= ds->ds_quota) {
3395 if (inflight > 0 ||
3396 ds->ds_phys->ds_referenced_bytes < ds->ds_quota)
3397 error = ERESTART;
3398 else
3399 error = EDQUOT;
3400 }
3401 mutex_exit(&ds->ds_lock);
3402
3403 return (error);
3404 }
3405
3406 /* ARGSUSED */
3407 static int
3408 dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx)
3409 {
3410 dsl_dataset_t *ds = arg1;
3411 dsl_prop_setarg_t *psa = arg2;
3412 int err;
3413
3414 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA)
3415 return (ENOTSUP);
3416
3417 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0)
3418 return (err);
3419
3420 if (psa->psa_effective_value == 0)
3421 return (0);
3422
3423 if (psa->psa_effective_value < ds->ds_phys->ds_referenced_bytes ||
3424 psa->psa_effective_value < ds->ds_reserved)
3425 return (ENOSPC);
3426
3427 return (0);
3428 }
3429
3430 extern void dsl_prop_set_sync(void *, void *, dmu_tx_t *);
3431
3432 void
3433 dsl_dataset_set_quota_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3434 {
3435 dsl_dataset_t *ds = arg1;
3436 dsl_prop_setarg_t *psa = arg2;
3437 uint64_t effective_value = psa->psa_effective_value;
3438
3439 dsl_prop_set_sync(ds, psa, tx);
3440 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa);
3441
3442 if (ds->ds_quota != effective_value) {
3443 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3444 ds->ds_quota = effective_value;
3445 }
3446 }
3447
3448 int
3449 dsl_dataset_set_quota(const char *dsname, zprop_source_t source, uint64_t quota)
3450 {
3451 dsl_dataset_t *ds;
3452 dsl_prop_setarg_t psa;
3453 int err;
3454
3455 dsl_prop_setarg_init_uint64(&psa, "refquota", source, "a);
3456
3457 err = dsl_dataset_hold(dsname, FTAG, &ds);
3458 if (err)
3459 return (err);
3460
3461 /*
3462 * If someone removes a file, then tries to set the quota, we
3463 * want to make sure the file freeing takes effect.
3464 */
3465 txg_wait_open(ds->ds_dir->dd_pool, 0);
3466
3467 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
3468 dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync,
3469 ds, &psa, 0);
3470
3471 dsl_dataset_rele(ds, FTAG);
3472 return (err);
3473 }
3474
3475 static int
3476 dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx)
3477 {
3478 dsl_dataset_t *ds = arg1;
3479 dsl_prop_setarg_t *psa = arg2;
3480 uint64_t effective_value;
3481 uint64_t unique;
3482 int err;
3483
3484 if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
3485 SPA_VERSION_REFRESERVATION)
3486 return (ENOTSUP);
3487
3488 if (dsl_dataset_is_snapshot(ds))
3489 return (EINVAL);
3490
3491 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0)
3492 return (err);
3493
3494 effective_value = psa->psa_effective_value;
3495
3496 /*
3497 * If we are doing the preliminary check in open context, the
3498 * space estimates may be inaccurate.
3499 */
3500 if (!dmu_tx_is_syncing(tx))
3501 return (0);
3502
3503 mutex_enter(&ds->ds_lock);
3504 if (!DS_UNIQUE_IS_ACCURATE(ds))
3505 dsl_dataset_recalc_head_uniq(ds);
3506 unique = ds->ds_phys->ds_unique_bytes;
3507 mutex_exit(&ds->ds_lock);
3508
3509 if (MAX(unique, effective_value) > MAX(unique, ds->ds_reserved)) {
3510 uint64_t delta = MAX(unique, effective_value) -
3511 MAX(unique, ds->ds_reserved);
3512
3513 if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
3514 return (ENOSPC);
3515 if (ds->ds_quota > 0 &&
3516 effective_value > ds->ds_quota)
3517 return (ENOSPC);
3518 }
3519
3520 return (0);
3521 }
3522
3523 static void
3524 dsl_dataset_set_reservation_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3525 {
3526 dsl_dataset_t *ds = arg1;
3527 dsl_prop_setarg_t *psa = arg2;
3528 uint64_t effective_value = psa->psa_effective_value;
3529 uint64_t unique;
3530 int64_t delta;
3531
3532 dsl_prop_set_sync(ds, psa, tx);
3533 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa);
3534
3535 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3536
3537 mutex_enter(&ds->ds_dir->dd_lock);
3538 mutex_enter(&ds->ds_lock);
3539 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
3540 unique = ds->ds_phys->ds_unique_bytes;
3541 delta = MAX(0, (int64_t)(effective_value - unique)) -
3542 MAX(0, (int64_t)(ds->ds_reserved - unique));
3543 ds->ds_reserved = effective_value;
3544 mutex_exit(&ds->ds_lock);
3545
3546 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx);
3547 mutex_exit(&ds->ds_dir->dd_lock);
3548 }
3549
3550 int
3551 dsl_dataset_set_reservation(const char *dsname, zprop_source_t source,
3552 uint64_t reservation)
3553 {
3554 dsl_dataset_t *ds;
3555 dsl_prop_setarg_t psa;
3556 int err;
3557
3558 dsl_prop_setarg_init_uint64(&psa, "refreservation", source,
3559 &reservation);
3560
3561 err = dsl_dataset_hold(dsname, FTAG, &ds);
3562 if (err)
3563 return (err);
3564
3565 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
3566 dsl_dataset_set_reservation_check,
3567 dsl_dataset_set_reservation_sync, ds, &psa, 0);
3568
3569 dsl_dataset_rele(ds, FTAG);
3570 return (err);
3571 }
3572
3573 typedef struct zfs_hold_cleanup_arg {
3574 dsl_pool_t *dp;
3575 uint64_t dsobj;
3576 char htag[MAXNAMELEN];
3577 } zfs_hold_cleanup_arg_t;
3578
3579 static void
3580 dsl_dataset_user_release_onexit(void *arg)
3581 {
3582 zfs_hold_cleanup_arg_t *ca = arg;
3583
3584 (void) dsl_dataset_user_release_tmp(ca->dp, ca->dsobj, ca->htag,
3585 B_TRUE);
3586 kmem_free(ca, sizeof (zfs_hold_cleanup_arg_t));
3587 }
3588
3589 void
3590 dsl_register_onexit_hold_cleanup(dsl_dataset_t *ds, const char *htag,
3591 minor_t minor)
3592 {
3593 zfs_hold_cleanup_arg_t *ca;
3594
3595 ca = kmem_alloc(sizeof (zfs_hold_cleanup_arg_t), KM_SLEEP);
3596 ca->dp = ds->ds_dir->dd_pool;
3597 ca->dsobj = ds->ds_object;
3598 (void) strlcpy(ca->htag, htag, sizeof (ca->htag));
3599 VERIFY3U(0, ==, zfs_onexit_add_cb(minor,
3600 dsl_dataset_user_release_onexit, ca, NULL));
3601 }
3602
3603 /*
3604 * If you add new checks here, you may need to add
3605 * additional checks to the "temporary" case in
3606 * snapshot_check() in dmu_objset.c.
3607 */
3608 static int
3609 dsl_dataset_user_hold_check(void *arg1, void *arg2, dmu_tx_t *tx)
3610 {
3611 dsl_dataset_t *ds = arg1;
3612 struct dsl_ds_holdarg *ha = arg2;
3613 const char *htag = ha->htag;
3614 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3615 int error = 0;
3616
3617 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS)
3618 return (ENOTSUP);
3619
3620 if (!dsl_dataset_is_snapshot(ds))
3621 return (EINVAL);
3622
3623 /* tags must be unique */
3624 mutex_enter(&ds->ds_lock);
3625 if (ds->ds_phys->ds_userrefs_obj) {
3626 error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj, htag,
3627 8, 1, tx);
3628 if (error == 0)
3629 error = EEXIST;
3630 else if (error == ENOENT)
3631 error = 0;
3632 }
3633 mutex_exit(&ds->ds_lock);
3634
3635 if (error == 0 && ha->temphold &&
3636 strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN)
3637 error = E2BIG;
3638
3639 return (error);
3640 }
3641
3642 void
3643 dsl_dataset_user_hold_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3644 {
3645 dsl_dataset_t *ds = arg1;
3646 struct dsl_ds_holdarg *ha = arg2;
3647 const char *htag = ha->htag;
3648 dsl_pool_t *dp = ds->ds_dir->dd_pool;
3649 objset_t *mos = dp->dp_meta_objset;
3650 uint64_t now = gethrestime_sec();
3651 uint64_t zapobj;
3652
3653 mutex_enter(&ds->ds_lock);
3654 if (ds->ds_phys->ds_userrefs_obj == 0) {
3655 /*
3656 * This is the first user hold for this dataset. Create
3657 * the userrefs zap object.
3658 */
3659 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3660 zapobj = ds->ds_phys->ds_userrefs_obj =
3661 zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx);
3662 } else {
3663 zapobj = ds->ds_phys->ds_userrefs_obj;
3664 }
3665 ds->ds_userrefs++;
3666 mutex_exit(&ds->ds_lock);
3667
3668 VERIFY(0 == zap_add(mos, zapobj, htag, 8, 1, &now, tx));
3669
3670 if (ha->temphold) {
3671 VERIFY(0 == dsl_pool_user_hold(dp, ds->ds_object,
3672 htag, &now, tx));
3673 }
3674
3675 spa_history_log_internal_ds(ds, "hold", tx,
3676 "tag = %s temp = %d holds now = %llu",
3677 htag, (int)ha->temphold, ds->ds_userrefs);
3678 }
3679
3680 static int
3681 dsl_dataset_user_hold_one(const char *dsname, void *arg)
3682 {
3683 struct dsl_ds_holdarg *ha = arg;
3684 dsl_dataset_t *ds;
3685 int error;
3686 char *name;
3687
3688 /* alloc a buffer to hold dsname@snapname plus terminating NULL */
3689 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3690 error = dsl_dataset_hold(name, ha->dstg, &ds);
3691 strfree(name);
3692 if (error == 0) {
3693 ha->gotone = B_TRUE;
3694 dsl_sync_task_create(ha->dstg, dsl_dataset_user_hold_check,
3695 dsl_dataset_user_hold_sync, ds, ha, 0);
3696 } else if (error == ENOENT && ha->recursive) {
3697 error = 0;
3698 } else {
3699 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3700 }
3701 return (error);
3702 }
3703
3704 int
3705 dsl_dataset_user_hold_for_send(dsl_dataset_t *ds, char *htag,
3706 boolean_t temphold)
3707 {
3708 struct dsl_ds_holdarg *ha;
3709 int error;
3710
3711 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3712 ha->htag = htag;
3713 ha->temphold = temphold;
3714 error = dsl_sync_task_do(ds->ds_dir->dd_pool,
3715 dsl_dataset_user_hold_check, dsl_dataset_user_hold_sync,
3716 ds, ha, 0);
3717 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3718
3719 return (error);
3720 }
3721
3722 int
3723 dsl_dataset_user_hold(char *dsname, char *snapname, char *htag,
3724 boolean_t recursive, boolean_t temphold, int cleanup_fd)
3725 {
3726 struct dsl_ds_holdarg *ha;
3727 dsl_sync_task_t *dst;
3728 spa_t *spa;
3729 int error;
3730 minor_t minor = 0;
3731
3732 if (cleanup_fd != -1) {
3733 /* Currently we only support cleanup-on-exit of tempholds. */
3734 if (!temphold)
3735 return (EINVAL);
3736 error = zfs_onexit_fd_hold(cleanup_fd, &minor);
3737 if (error)
3738 return (error);
3739 }
3740
3741 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3742
3743 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3744
3745 error = spa_open(dsname, &spa, FTAG);
3746 if (error) {
3747 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3748 if (cleanup_fd != -1)
3749 zfs_onexit_fd_rele(cleanup_fd);
3750 return (error);
3751 }
3752
3753 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
3754 ha->htag = htag;
3755 ha->snapname = snapname;
3756 ha->recursive = recursive;
3757 ha->temphold = temphold;
3758
3759 if (recursive) {
3760 error = dmu_objset_find(dsname, dsl_dataset_user_hold_one,
3761 ha, DS_FIND_CHILDREN);
3762 } else {
3763 error = dsl_dataset_user_hold_one(dsname, ha);
3764 }
3765 if (error == 0)
3766 error = dsl_sync_task_group_wait(ha->dstg);
3767
3768 for (dst = list_head(&ha->dstg->dstg_tasks); dst;
3769 dst = list_next(&ha->dstg->dstg_tasks, dst)) {
3770 dsl_dataset_t *ds = dst->dst_arg1;
3771
3772 if (dst->dst_err) {
3773 dsl_dataset_name(ds, ha->failed);
3774 *strchr(ha->failed, '@') = '\0';
3775 } else if (error == 0 && minor != 0 && temphold) {
3776 /*
3777 * If this hold is to be released upon process exit,
3778 * register that action now.
3779 */
3780 dsl_register_onexit_hold_cleanup(ds, htag, minor);
3781 }
3782 dsl_dataset_rele(ds, ha->dstg);
3783 }
3784
3785 if (error == 0 && recursive && !ha->gotone)
3786 error = ENOENT;
3787
3788 if (error)
3789 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed));
3790
3791 dsl_sync_task_group_destroy(ha->dstg);
3792
3793 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3794 spa_close(spa, FTAG);
3795 if (cleanup_fd != -1)
3796 zfs_onexit_fd_rele(cleanup_fd);
3797 return (error);
3798 }
3799
3800 struct dsl_ds_releasearg {
3801 dsl_dataset_t *ds;
3802 const char *htag;
3803 boolean_t own; /* do we own or just hold ds? */
3804 };
3805
3806 static int
3807 dsl_dataset_release_might_destroy(dsl_dataset_t *ds, const char *htag,
3808 boolean_t *might_destroy)
3809 {
3810 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3811 uint64_t zapobj;
3812 uint64_t tmp;
3813 int error;
3814
3815 *might_destroy = B_FALSE;
3816
3817 mutex_enter(&ds->ds_lock);
3818 zapobj = ds->ds_phys->ds_userrefs_obj;
3819 if (zapobj == 0) {
3820 /* The tag can't possibly exist */
3821 mutex_exit(&ds->ds_lock);
3822 return (ESRCH);
3823 }
3824
3825 /* Make sure the tag exists */
3826 error = zap_lookup(mos, zapobj, htag, 8, 1, &tmp);
3827 if (error) {
3828 mutex_exit(&ds->ds_lock);
3829 if (error == ENOENT)
3830 error = ESRCH;
3831 return (error);
3832 }
3833
3834 if (ds->ds_userrefs == 1 && ds->ds_phys->ds_num_children == 1 &&
3835 DS_IS_DEFER_DESTROY(ds))
3836 *might_destroy = B_TRUE;
3837
3838 mutex_exit(&ds->ds_lock);
3839 return (0);
3840 }
3841
3842 static int
3843 dsl_dataset_user_release_check(void *arg1, void *tag, dmu_tx_t *tx)
3844 {
3845 struct dsl_ds_releasearg *ra = arg1;
3846 dsl_dataset_t *ds = ra->ds;
3847 boolean_t might_destroy;
3848 int error;
3849
3850 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS)
3851 return (ENOTSUP);
3852
3853 error = dsl_dataset_release_might_destroy(ds, ra->htag, &might_destroy);
3854 if (error)
3855 return (error);
3856
3857 if (might_destroy) {
3858 struct dsl_ds_destroyarg dsda = {0};
3859
3860 if (dmu_tx_is_syncing(tx)) {
3861 /*
3862 * If we're not prepared to remove the snapshot,
3863 * we can't allow the release to happen right now.
3864 */
3865 if (!ra->own)
3866 return (EBUSY);
3867 }
3868 dsda.ds = ds;
3869 dsda.releasing = B_TRUE;
3870 return (dsl_dataset_destroy_check(&dsda, tag, tx));
3871 }
3872
3873 return (0);
3874 }
3875
3876 static void
3877 dsl_dataset_user_release_sync(void *arg1, void *tag, dmu_tx_t *tx)
3878 {
3879 struct dsl_ds_releasearg *ra = arg1;
3880 dsl_dataset_t *ds = ra->ds;
3881 dsl_pool_t *dp = ds->ds_dir->dd_pool;
3882 objset_t *mos = dp->dp_meta_objset;
3883 uint64_t zapobj;
3884 uint64_t refs;
3885 int error;
3886
3887 mutex_enter(&ds->ds_lock);
3888 ds->ds_userrefs--;
3889 refs = ds->ds_userrefs;
3890 mutex_exit(&ds->ds_lock);
3891 error = dsl_pool_user_release(dp, ds->ds_object, ra->htag, tx);
3892 VERIFY(error == 0 || error == ENOENT);
3893 zapobj = ds->ds_phys->ds_userrefs_obj;
3894 VERIFY(0 == zap_remove(mos, zapobj, ra->htag, tx));
3895
3896 spa_history_log_internal_ds(ds, "release", tx,
3897 "tag = %s refs now = %lld", ra->htag, (longlong_t)refs);
3898
3899 if (ds->ds_userrefs == 0 && ds->ds_phys->ds_num_children == 1 &&
3900 DS_IS_DEFER_DESTROY(ds)) {
3901 struct dsl_ds_destroyarg dsda = {0};
3902
3903 ASSERT(ra->own);
3904 dsda.ds = ds;
3905 dsda.releasing = B_TRUE;
3906 /* We already did the destroy_check */
3907 dsl_dataset_destroy_sync(&dsda, tag, tx);
3908 }
3909 }
3910
3911 static int
3912 dsl_dataset_user_release_one(const char *dsname, void *arg)
3913 {
3914 struct dsl_ds_holdarg *ha = arg;
3915 struct dsl_ds_releasearg *ra;
3916 dsl_dataset_t *ds;
3917 int error;
3918 void *dtag = ha->dstg;
3919 char *name;
3920 boolean_t own = B_FALSE;
3921 boolean_t might_destroy;
3922
3923 /* alloc a buffer to hold dsname@snapname, plus the terminating NULL */
3924 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3925 error = dsl_dataset_hold(name, dtag, &ds);
3926 strfree(name);
3927 if (error == ENOENT && ha->recursive)
3928 return (0);
3929 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3930 if (error)
3931 return (error);
3932
3933 ha->gotone = B_TRUE;
3934
3935 ASSERT(dsl_dataset_is_snapshot(ds));
3936
3937 error = dsl_dataset_release_might_destroy(ds, ha->htag, &might_destroy);
3938 if (error) {
3939 dsl_dataset_rele(ds, dtag);
3940 return (error);
3941 }
3942
3943 if (might_destroy) {
3944 #ifdef _KERNEL
3945 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3946 error = zfs_unmount_snap(name, NULL);
3947 strfree(name);
3948 if (error) {
3949 dsl_dataset_rele(ds, dtag);
3950 return (error);
3951 }
3952 #endif
3953 if (!dsl_dataset_tryown(ds, B_TRUE, dtag)) {
3954 dsl_dataset_rele(ds, dtag);
3955 return (EBUSY);
3956 } else {
3957 own = B_TRUE;
3958 dsl_dataset_make_exclusive(ds, dtag);
3959 }
3960 }
3961
3962 ra = kmem_alloc(sizeof (struct dsl_ds_releasearg), KM_SLEEP);
3963 ra->ds = ds;
3964 ra->htag = ha->htag;
3965 ra->own = own;
3966 dsl_sync_task_create(ha->dstg, dsl_dataset_user_release_check,
3967 dsl_dataset_user_release_sync, ra, dtag, 0);
3968
3969 return (0);
3970 }
3971
3972 int
3973 dsl_dataset_user_release(char *dsname, char *snapname, char *htag,
3974 boolean_t recursive)
3975 {
3976 struct dsl_ds_holdarg *ha;
3977 dsl_sync_task_t *dst;
3978 spa_t *spa;
3979 int error;
3980
3981 top:
3982 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3983
3984 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3985
3986 error = spa_open(dsname, &spa, FTAG);
3987 if (error) {
3988 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3989 return (error);
3990 }
3991
3992 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
3993 ha->htag = htag;
3994 ha->snapname = snapname;
3995 ha->recursive = recursive;
3996 if (recursive) {
3997 error = dmu_objset_find(dsname, dsl_dataset_user_release_one,
3998 ha, DS_FIND_CHILDREN);
3999 } else {
4000 error = dsl_dataset_user_release_one(dsname, ha);
4001 }
4002 if (error == 0)
4003 error = dsl_sync_task_group_wait(ha->dstg);
4004
4005 for (dst = list_head(&ha->dstg->dstg_tasks); dst;
4006 dst = list_next(&ha->dstg->dstg_tasks, dst)) {
4007 struct dsl_ds_releasearg *ra = dst->dst_arg1;
4008 dsl_dataset_t *ds = ra->ds;
4009
4010 if (dst->dst_err)
4011 dsl_dataset_name(ds, ha->failed);
4012
4013 if (ra->own)
4014 dsl_dataset_disown(ds, ha->dstg);
4015 else
4016 dsl_dataset_rele(ds, ha->dstg);
4017
4018 kmem_free(ra, sizeof (struct dsl_ds_releasearg));
4019 }
4020
4021 if (error == 0 && recursive && !ha->gotone)
4022 error = ENOENT;
4023
4024 if (error && error != EBUSY)
4025 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed));
4026
4027 dsl_sync_task_group_destroy(ha->dstg);
4028 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
4029 spa_close(spa, FTAG);
4030
4031 /*
4032 * We can get EBUSY if we were racing with deferred destroy and
4033 * dsl_dataset_user_release_check() hadn't done the necessary
4034 * open context setup. We can also get EBUSY if we're racing
4035 * with destroy and that thread is the ds_owner. Either way
4036 * the busy condition should be transient, and we should retry
4037 * the release operation.
4038 */
4039 if (error == EBUSY)
4040 goto top;
4041
4042 return (error);
4043 }
4044
4045 /*
4046 * Called at spa_load time (with retry == B_FALSE) to release a stale
4047 * temporary user hold. Also called by the onexit code (with retry == B_TRUE).
4048 */
4049 int
4050 dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, char *htag,
4051 boolean_t retry)
4052 {
4053 dsl_dataset_t *ds;
4054 char *snap;
4055 char *name;
4056 int namelen;
4057 int error;
4058
4059 do {
4060 rw_enter(&dp->dp_config_rwlock, RW_READER);
4061 error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds);
4062 rw_exit(&dp->dp_config_rwlock);
4063 if (error)
4064 return (error);
4065 namelen = dsl_dataset_namelen(ds)+1;
4066 name = kmem_alloc(namelen, KM_SLEEP);
4067 dsl_dataset_name(ds, name);
4068 dsl_dataset_rele(ds, FTAG);
4069
4070 snap = strchr(name, '@');
4071 *snap = '\0';
4072 ++snap;
4073 error = dsl_dataset_user_release(name, snap, htag, B_FALSE);
4074 kmem_free(name, namelen);
4075
4076 /*
4077 * The object can't have been destroyed because we have a hold,
4078 * but it might have been renamed, resulting in ENOENT. Retry
4079 * if we've been requested to do so.
4080 *
4081 * It would be nice if we could use the dsobj all the way
4082 * through and avoid ENOENT entirely. But we might need to
4083 * unmount the snapshot, and there's currently no way to lookup
4084 * a vfsp using a ZFS object id.
4085 */
4086 } while ((error == ENOENT) && retry);
4087
4088 return (error);
4089 }
4090
4091 int
4092 dsl_dataset_get_holds(const char *dsname, nvlist_t **nvp)
4093 {
4094 dsl_dataset_t *ds;
4095 int err;
4096
4097 err = dsl_dataset_hold(dsname, FTAG, &ds);
4098 if (err)
4099 return (err);
4100
4101 VERIFY(0 == nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP));
4102 if (ds->ds_phys->ds_userrefs_obj != 0) {
4103 zap_attribute_t *za;
4104 zap_cursor_t zc;
4105
4106 za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP);
4107 for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset,
4108 ds->ds_phys->ds_userrefs_obj);
4109 zap_cursor_retrieve(&zc, za) == 0;
4110 zap_cursor_advance(&zc)) {
4111 VERIFY(0 == nvlist_add_uint64(*nvp, za->za_name,
4112 za->za_first_integer));
4113 }
4114 zap_cursor_fini(&zc);
4115 kmem_free(za, sizeof (zap_attribute_t));
4116 }
4117 dsl_dataset_rele(ds, FTAG);
4118 return (0);
4119 }
4120
4121 /*
4122 * Note, this function is used as the callback for dmu_objset_find(). We
4123 * always return 0 so that we will continue to find and process
4124 * inconsistent datasets, even if we encounter an error trying to
4125 * process one of them.
4126 */
4127 /* ARGSUSED */
4128 int
4129 dsl_destroy_inconsistent(const char *dsname, void *arg)
4130 {
4131 dsl_dataset_t *ds;
4132
4133 if (dsl_dataset_own(dsname, B_TRUE, FTAG, &ds) == 0) {
4134 if (DS_IS_INCONSISTENT(ds))
4135 (void) dsl_dataset_destroy(ds, FTAG, B_FALSE);
4136 else
4137 dsl_dataset_disown(ds, FTAG);
4138 }
4139 return (0);
4140 }
4141
4142 /*
4143 * Return (in *usedp) the amount of space written in new that is not
4144 * present in oldsnap. New may be a snapshot or the head. Old must be
4145 * a snapshot before new, in new's filesystem (or its origin). If not then
4146 * fail and return EINVAL.
4147 *
4148 * The written space is calculated by considering two components: First, we
4149 * ignore any freed space, and calculate the written as new's used space
4150 * minus old's used space. Next, we add in the amount of space that was freed
4151 * between the two snapshots, thus reducing new's used space relative to old's.
4152 * Specifically, this is the space that was born before old->ds_creation_txg,
4153 * and freed before new (ie. on new's deadlist or a previous deadlist).
4154 *
4155 * space freed [---------------------]
4156 * snapshots ---O-------O--------O-------O------
4157 * oldsnap new
4158 */
4159 int
4160 dsl_dataset_space_written(dsl_dataset_t *oldsnap, dsl_dataset_t *new,
4161 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
4162 {
4163 int err = 0;
4164 uint64_t snapobj;
4165 dsl_pool_t *dp = new->ds_dir->dd_pool;
4166
4167 *usedp = 0;
4168 *usedp += new->ds_phys->ds_referenced_bytes;
4169 *usedp -= oldsnap->ds_phys->ds_referenced_bytes;
4170
4171 *compp = 0;
4172 *compp += new->ds_phys->ds_compressed_bytes;
4173 *compp -= oldsnap->ds_phys->ds_compressed_bytes;
4174
4175 *uncompp = 0;
4176 *uncompp += new->ds_phys->ds_uncompressed_bytes;
4177 *uncompp -= oldsnap->ds_phys->ds_uncompressed_bytes;
4178
4179 rw_enter(&dp->dp_config_rwlock, RW_READER);
4180 snapobj = new->ds_object;
4181 while (snapobj != oldsnap->ds_object) {
4182 dsl_dataset_t *snap;
4183 uint64_t used, comp, uncomp;
4184
4185 if (snapobj == new->ds_object) {
4186 snap = new;
4187 } else {
4188 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &snap);
4189 if (err != 0)
4190 break;
4191 }
4192
4193 if (snap->ds_phys->ds_prev_snap_txg ==
4194 oldsnap->ds_phys->ds_creation_txg) {
4195 /*
4196 * The blocks in the deadlist can not be born after
4197 * ds_prev_snap_txg, so get the whole deadlist space,
4198 * which is more efficient (especially for old-format
4199 * deadlists). Unfortunately the deadlist code
4200 * doesn't have enough information to make this
4201 * optimization itself.
4202 */
4203 dsl_deadlist_space(&snap->ds_deadlist,
4204 &used, &comp, &uncomp);
4205 } else {
4206 dsl_deadlist_space_range(&snap->ds_deadlist,
4207 0, oldsnap->ds_phys->ds_creation_txg,
4208 &used, &comp, &uncomp);
4209 }
4210 *usedp += used;
4211 *compp += comp;
4212 *uncompp += uncomp;
4213
4214 /*
4215 * If we get to the beginning of the chain of snapshots
4216 * (ds_prev_snap_obj == 0) before oldsnap, then oldsnap
4217 * was not a snapshot of/before new.
4218 */
4219 snapobj = snap->ds_phys->ds_prev_snap_obj;
4220 if (snap != new)
4221 dsl_dataset_rele(snap, FTAG);
4222 if (snapobj == 0) {
4223 err = EINVAL;
4224 break;
4225 }
4226
4227 }
4228 rw_exit(&dp->dp_config_rwlock);
4229 return (err);
4230 }
4231
4232 /*
4233 * Return (in *usedp) the amount of space that will be reclaimed if firstsnap,
4234 * lastsnap, and all snapshots in between are deleted.
4235 *
4236 * blocks that would be freed [---------------------------]
4237 * snapshots ---O-------O--------O-------O--------O
4238 * firstsnap lastsnap
4239 *
4240 * This is the set of blocks that were born after the snap before firstsnap,
4241 * (birth > firstsnap->prev_snap_txg) and died before the snap after the
4242 * last snap (ie, is on lastsnap->ds_next->ds_deadlist or an earlier deadlist).
4243 * We calculate this by iterating over the relevant deadlists (from the snap
4244 * after lastsnap, backward to the snap after firstsnap), summing up the
4245 * space on the deadlist that was born after the snap before firstsnap.
4246 */
4247 int
4248 dsl_dataset_space_wouldfree(dsl_dataset_t *firstsnap,
4249 dsl_dataset_t *lastsnap,
4250 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
4251 {
4252 int err = 0;
4253 uint64_t snapobj;
4254 dsl_pool_t *dp = firstsnap->ds_dir->dd_pool;
4255
4256 ASSERT(dsl_dataset_is_snapshot(firstsnap));
4257 ASSERT(dsl_dataset_is_snapshot(lastsnap));
4258
4259 /*
4260 * Check that the snapshots are in the same dsl_dir, and firstsnap
4261 * is before lastsnap.
4262 */
4263 if (firstsnap->ds_dir != lastsnap->ds_dir ||
4264 firstsnap->ds_phys->ds_creation_txg >
4265 lastsnap->ds_phys->ds_creation_txg)
4266 return (EINVAL);
4267
4268 *usedp = *compp = *uncompp = 0;
4269
4270 rw_enter(&dp->dp_config_rwlock, RW_READER);
4271 snapobj = lastsnap->ds_phys->ds_next_snap_obj;
4272 while (snapobj != firstsnap->ds_object) {
4273 dsl_dataset_t *ds;
4274 uint64_t used, comp, uncomp;
4275
4276 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &ds);
4277 if (err != 0)
4278 break;
4279
4280 dsl_deadlist_space_range(&ds->ds_deadlist,
4281 firstsnap->ds_phys->ds_prev_snap_txg, UINT64_MAX,
4282 &used, &comp, &uncomp);
4283 *usedp += used;
4284 *compp += comp;
4285 *uncompp += uncomp;
4286
4287 snapobj = ds->ds_phys->ds_prev_snap_obj;
4288 ASSERT3U(snapobj, !=, 0);
4289 dsl_dataset_rele(ds, FTAG);
4290 }
4291 rw_exit(&dp->dp_config_rwlock);
4292 return (err);
4293 }