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1949 crash during reguid causes stale config
[unleashed.git] / usr / src / uts / common / fs / zfs / dsl_dataset.c
blob5ef7f54af176100eafa938a9421abfb2853021c0
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) 2011 by Delphix. All rights reserved.
24 */
25
26 #include <sys/dmu_objset.h>
27 #include <sys/dsl_dataset.h>
28 #include <sys/dsl_dir.h>
29 #include <sys/dsl_prop.h>
30 #include <sys/dsl_synctask.h>
31 #include <sys/dmu_traverse.h>
32 #include <sys/dmu_tx.h>
33 #include <sys/arc.h>
34 #include <sys/zio.h>
35 #include <sys/zap.h>
36 #include <sys/unique.h>
37 #include <sys/zfs_context.h>
38 #include <sys/zfs_ioctl.h>
39 #include <sys/spa.h>
40 #include <sys/zfs_znode.h>
41 #include <sys/zfs_onexit.h>
42 #include <sys/zvol.h>
43 #include <sys/dsl_scan.h>
44 #include <sys/dsl_deadlist.h>
45
46 static char *dsl_reaper = "the grim reaper";
47
48 static dsl_checkfunc_t dsl_dataset_destroy_begin_check;
49 static dsl_syncfunc_t dsl_dataset_destroy_begin_sync;
50 static dsl_syncfunc_t dsl_dataset_set_reservation_sync;
51
52 #define SWITCH64(x, y) \
53 { \
54 uint64_t __tmp = (x); \
55 (x) = (y); \
56 (y) = __tmp; \
57 }
58
59 #define DS_REF_MAX (1ULL << 62)
60
61 #define DSL_DEADLIST_BLOCKSIZE SPA_MAXBLOCKSIZE
62
63 #define DSL_DATASET_IS_DESTROYED(ds) ((ds)->ds_owner == dsl_reaper)
64
65
66 /*
67 * Figure out how much of this delta should be propogated to the dsl_dir
68 * layer. If there's a refreservation, that space has already been
69 * partially accounted for in our ancestors.
70 */
71 static int64_t
72 parent_delta(dsl_dataset_t *ds, int64_t delta)
73 {
74 uint64_t old_bytes, new_bytes;
75
76 if (ds->ds_reserved == 0)
77 return (delta);
78
79 old_bytes = MAX(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
80 new_bytes = MAX(ds->ds_phys->ds_unique_bytes + delta, ds->ds_reserved);
81
82 ASSERT3U(ABS((int64_t)(new_bytes - old_bytes)), <=, ABS(delta));
83 return (new_bytes - old_bytes);
84 }
85
86 void
87 dsl_dataset_block_born(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx)
88 {
89 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
90 int compressed = BP_GET_PSIZE(bp);
91 int uncompressed = BP_GET_UCSIZE(bp);
92 int64_t delta;
93
94 dprintf_bp(bp, "ds=%p", ds);
95
96 ASSERT(dmu_tx_is_syncing(tx));
97 /* It could have been compressed away to nothing */
98 if (BP_IS_HOLE(bp))
99 return;
100 ASSERT(BP_GET_TYPE(bp) != DMU_OT_NONE);
101 ASSERT3U(BP_GET_TYPE(bp), <, DMU_OT_NUMTYPES);
102 if (ds == NULL) {
103 /*
104 * Account for the meta-objset space in its placeholder
105 * dsl_dir.
106 */
107 ASSERT3U(compressed, ==, uncompressed); /* it's all metadata */
108 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD,
109 used, compressed, uncompressed, tx);
110 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx);
111 return;
112 }
113 dmu_buf_will_dirty(ds->ds_dbuf, tx);
114
115 mutex_enter(&ds->ds_dir->dd_lock);
116 mutex_enter(&ds->ds_lock);
117 delta = parent_delta(ds, used);
118 ds->ds_phys->ds_used_bytes += used;
119 ds->ds_phys->ds_compressed_bytes += compressed;
120 ds->ds_phys->ds_uncompressed_bytes += uncompressed;
121 ds->ds_phys->ds_unique_bytes += used;
122 mutex_exit(&ds->ds_lock);
123 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD, delta,
124 compressed, uncompressed, tx);
125 dsl_dir_transfer_space(ds->ds_dir, used - delta,
126 DD_USED_REFRSRV, DD_USED_HEAD, tx);
127 mutex_exit(&ds->ds_dir->dd_lock);
128 }
129
130 int
131 dsl_dataset_block_kill(dsl_dataset_t *ds, const blkptr_t *bp, dmu_tx_t *tx,
132 boolean_t async)
133 {
134 if (BP_IS_HOLE(bp))
135 return (0);
136
137 ASSERT(dmu_tx_is_syncing(tx));
138 ASSERT(bp->blk_birth <= tx->tx_txg);
139
140 int used = bp_get_dsize_sync(tx->tx_pool->dp_spa, bp);
141 int compressed = BP_GET_PSIZE(bp);
142 int uncompressed = BP_GET_UCSIZE(bp);
143
144 ASSERT(used > 0);
145 if (ds == NULL) {
146 /*
147 * Account for the meta-objset space in its placeholder
148 * dataset.
149 */
150 dsl_free(tx->tx_pool, tx->tx_txg, bp);
151
152 dsl_dir_diduse_space(tx->tx_pool->dp_mos_dir, DD_USED_HEAD,
153 -used, -compressed, -uncompressed, tx);
154 dsl_dir_dirty(tx->tx_pool->dp_mos_dir, tx);
155 return (used);
156 }
157 ASSERT3P(tx->tx_pool, ==, ds->ds_dir->dd_pool);
158
159 ASSERT(!dsl_dataset_is_snapshot(ds));
160 dmu_buf_will_dirty(ds->ds_dbuf, tx);
161
162 if (bp->blk_birth > ds->ds_phys->ds_prev_snap_txg) {
163 int64_t delta;
164
165 dprintf_bp(bp, "freeing ds=%llu", ds->ds_object);
166 dsl_free(tx->tx_pool, tx->tx_txg, bp);
167
168 mutex_enter(&ds->ds_dir->dd_lock);
169 mutex_enter(&ds->ds_lock);
170 ASSERT(ds->ds_phys->ds_unique_bytes >= used ||
171 !DS_UNIQUE_IS_ACCURATE(ds));
172 delta = parent_delta(ds, -used);
173 ds->ds_phys->ds_unique_bytes -= used;
174 mutex_exit(&ds->ds_lock);
175 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
176 delta, -compressed, -uncompressed, tx);
177 dsl_dir_transfer_space(ds->ds_dir, -used - delta,
178 DD_USED_REFRSRV, DD_USED_HEAD, tx);
179 mutex_exit(&ds->ds_dir->dd_lock);
180 } else {
181 dprintf_bp(bp, "putting on dead list: %s", "");
182 if (async) {
183 /*
184 * We are here as part of zio's write done callback,
185 * which means we're a zio interrupt thread. We can't
186 * call dsl_deadlist_insert() now because it may block
187 * waiting for I/O. Instead, put bp on the deferred
188 * queue and let dsl_pool_sync() finish the job.
189 */
190 bplist_append(&ds->ds_pending_deadlist, bp);
191 } else {
192 dsl_deadlist_insert(&ds->ds_deadlist, bp, tx);
193 }
194 ASSERT3U(ds->ds_prev->ds_object, ==,
195 ds->ds_phys->ds_prev_snap_obj);
196 ASSERT(ds->ds_prev->ds_phys->ds_num_children > 0);
197 /* if (bp->blk_birth > prev prev snap txg) prev unique += bs */
198 if (ds->ds_prev->ds_phys->ds_next_snap_obj ==
199 ds->ds_object && bp->blk_birth >
200 ds->ds_prev->ds_phys->ds_prev_snap_txg) {
201 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
202 mutex_enter(&ds->ds_prev->ds_lock);
203 ds->ds_prev->ds_phys->ds_unique_bytes += used;
204 mutex_exit(&ds->ds_prev->ds_lock);
205 }
206 if (bp->blk_birth > ds->ds_dir->dd_origin_txg) {
207 dsl_dir_transfer_space(ds->ds_dir, used,
208 DD_USED_HEAD, DD_USED_SNAP, tx);
209 }
210 }
211 mutex_enter(&ds->ds_lock);
212 ASSERT3U(ds->ds_phys->ds_used_bytes, >=, used);
213 ds->ds_phys->ds_used_bytes -= used;
214 ASSERT3U(ds->ds_phys->ds_compressed_bytes, >=, compressed);
215 ds->ds_phys->ds_compressed_bytes -= compressed;
216 ASSERT3U(ds->ds_phys->ds_uncompressed_bytes, >=, uncompressed);
217 ds->ds_phys->ds_uncompressed_bytes -= uncompressed;
218 mutex_exit(&ds->ds_lock);
219
220 return (used);
221 }
222
223 uint64_t
224 dsl_dataset_prev_snap_txg(dsl_dataset_t *ds)
225 {
226 uint64_t trysnap = 0;
227
228 if (ds == NULL)
229 return (0);
230 /*
231 * The snapshot creation could fail, but that would cause an
232 * incorrect FALSE return, which would only result in an
233 * overestimation of the amount of space that an operation would
234 * consume, which is OK.
235 *
236 * There's also a small window where we could miss a pending
237 * snapshot, because we could set the sync task in the quiescing
238 * phase. So this should only be used as a guess.
239 */
240 if (ds->ds_trysnap_txg >
241 spa_last_synced_txg(ds->ds_dir->dd_pool->dp_spa))
242 trysnap = ds->ds_trysnap_txg;
243 return (MAX(ds->ds_phys->ds_prev_snap_txg, trysnap));
244 }
245
246 boolean_t
247 dsl_dataset_block_freeable(dsl_dataset_t *ds, const blkptr_t *bp,
248 uint64_t blk_birth)
249 {
250 if (blk_birth <= dsl_dataset_prev_snap_txg(ds))
251 return (B_FALSE);
252
253 ddt_prefetch(dsl_dataset_get_spa(ds), bp);
254
255 return (B_TRUE);
256 }
257
258 /* ARGSUSED */
259 static void
260 dsl_dataset_evict(dmu_buf_t *db, void *dsv)
261 {
262 dsl_dataset_t *ds = dsv;
263
264 ASSERT(ds->ds_owner == NULL || DSL_DATASET_IS_DESTROYED(ds));
265
266 unique_remove(ds->ds_fsid_guid);
267
268 if (ds->ds_objset != NULL)
269 dmu_objset_evict(ds->ds_objset);
270
271 if (ds->ds_prev) {
272 dsl_dataset_drop_ref(ds->ds_prev, ds);
273 ds->ds_prev = NULL;
274 }
275
276 bplist_destroy(&ds->ds_pending_deadlist);
277 if (db != NULL) {
278 dsl_deadlist_close(&ds->ds_deadlist);
279 } else {
280 ASSERT(ds->ds_deadlist.dl_dbuf == NULL);
281 ASSERT(!ds->ds_deadlist.dl_oldfmt);
282 }
283 if (ds->ds_dir)
284 dsl_dir_close(ds->ds_dir, ds);
285
286 ASSERT(!list_link_active(&ds->ds_synced_link));
287
288 mutex_destroy(&ds->ds_lock);
289 mutex_destroy(&ds->ds_recvlock);
290 mutex_destroy(&ds->ds_opening_lock);
291 rw_destroy(&ds->ds_rwlock);
292 cv_destroy(&ds->ds_exclusive_cv);
293
294 kmem_free(ds, sizeof (dsl_dataset_t));
295 }
296
297 static int
298 dsl_dataset_get_snapname(dsl_dataset_t *ds)
299 {
300 dsl_dataset_phys_t *headphys;
301 int err;
302 dmu_buf_t *headdbuf;
303 dsl_pool_t *dp = ds->ds_dir->dd_pool;
304 objset_t *mos = dp->dp_meta_objset;
305
306 if (ds->ds_snapname[0])
307 return (0);
308 if (ds->ds_phys->ds_next_snap_obj == 0)
309 return (0);
310
311 err = dmu_bonus_hold(mos, ds->ds_dir->dd_phys->dd_head_dataset_obj,
312 FTAG, &headdbuf);
313 if (err)
314 return (err);
315 headphys = headdbuf->db_data;
316 err = zap_value_search(dp->dp_meta_objset,
317 headphys->ds_snapnames_zapobj, ds->ds_object, 0, ds->ds_snapname);
318 dmu_buf_rele(headdbuf, FTAG);
319 return (err);
320 }
321
322 static int
323 dsl_dataset_snap_lookup(dsl_dataset_t *ds, const char *name, uint64_t *value)
324 {
325 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
326 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
327 matchtype_t mt;
328 int err;
329
330 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
331 mt = MT_FIRST;
332 else
333 mt = MT_EXACT;
334
335 err = zap_lookup_norm(mos, snapobj, name, 8, 1,
336 value, mt, NULL, 0, NULL);
337 if (err == ENOTSUP && mt == MT_FIRST)
338 err = zap_lookup(mos, snapobj, name, 8, 1, value);
339 return (err);
340 }
341
342 static int
343 dsl_dataset_snap_remove(dsl_dataset_t *ds, char *name, dmu_tx_t *tx)
344 {
345 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
346 uint64_t snapobj = ds->ds_phys->ds_snapnames_zapobj;
347 matchtype_t mt;
348 int err;
349
350 dsl_dir_snap_cmtime_update(ds->ds_dir);
351
352 if (ds->ds_phys->ds_flags & DS_FLAG_CI_DATASET)
353 mt = MT_FIRST;
354 else
355 mt = MT_EXACT;
356
357 err = zap_remove_norm(mos, snapobj, name, mt, tx);
358 if (err == ENOTSUP && mt == MT_FIRST)
359 err = zap_remove(mos, snapobj, name, tx);
360 return (err);
361 }
362
363 static int
364 dsl_dataset_get_ref(dsl_pool_t *dp, uint64_t dsobj, void *tag,
365 dsl_dataset_t **dsp)
366 {
367 objset_t *mos = dp->dp_meta_objset;
368 dmu_buf_t *dbuf;
369 dsl_dataset_t *ds;
370 int err;
371 dmu_object_info_t doi;
372
373 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) ||
374 dsl_pool_sync_context(dp));
375
376 err = dmu_bonus_hold(mos, dsobj, tag, &dbuf);
377 if (err)
378 return (err);
379
380 /* Make sure dsobj has the correct object type. */
381 dmu_object_info_from_db(dbuf, &doi);
382 if (doi.doi_type != DMU_OT_DSL_DATASET)
383 return (EINVAL);
384
385 ds = dmu_buf_get_user(dbuf);
386 if (ds == NULL) {
387 dsl_dataset_t *winner;
388
389 ds = kmem_zalloc(sizeof (dsl_dataset_t), KM_SLEEP);
390 ds->ds_dbuf = dbuf;
391 ds->ds_object = dsobj;
392 ds->ds_phys = dbuf->db_data;
393
394 mutex_init(&ds->ds_lock, NULL, MUTEX_DEFAULT, NULL);
395 mutex_init(&ds->ds_recvlock, NULL, MUTEX_DEFAULT, NULL);
396 mutex_init(&ds->ds_opening_lock, NULL, MUTEX_DEFAULT, NULL);
397 rw_init(&ds->ds_rwlock, 0, 0, 0);
398 cv_init(&ds->ds_exclusive_cv, NULL, CV_DEFAULT, NULL);
399
400 bplist_create(&ds->ds_pending_deadlist);
401 dsl_deadlist_open(&ds->ds_deadlist,
402 mos, ds->ds_phys->ds_deadlist_obj);
403
404 if (err == 0) {
405 err = dsl_dir_open_obj(dp,
406 ds->ds_phys->ds_dir_obj, NULL, ds, &ds->ds_dir);
407 }
408 if (err) {
409 mutex_destroy(&ds->ds_lock);
410 mutex_destroy(&ds->ds_recvlock);
411 mutex_destroy(&ds->ds_opening_lock);
412 rw_destroy(&ds->ds_rwlock);
413 cv_destroy(&ds->ds_exclusive_cv);
414 bplist_destroy(&ds->ds_pending_deadlist);
415 dsl_deadlist_close(&ds->ds_deadlist);
416 kmem_free(ds, sizeof (dsl_dataset_t));
417 dmu_buf_rele(dbuf, tag);
418 return (err);
419 }
420
421 if (!dsl_dataset_is_snapshot(ds)) {
422 ds->ds_snapname[0] = '\0';
423 if (ds->ds_phys->ds_prev_snap_obj) {
424 err = dsl_dataset_get_ref(dp,
425 ds->ds_phys->ds_prev_snap_obj,
426 ds, &ds->ds_prev);
427 }
428 } else {
429 if (zfs_flags & ZFS_DEBUG_SNAPNAMES)
430 err = dsl_dataset_get_snapname(ds);
431 if (err == 0 && ds->ds_phys->ds_userrefs_obj != 0) {
432 err = zap_count(
433 ds->ds_dir->dd_pool->dp_meta_objset,
434 ds->ds_phys->ds_userrefs_obj,
435 &ds->ds_userrefs);
436 }
437 }
438
439 if (err == 0 && !dsl_dataset_is_snapshot(ds)) {
440 /*
441 * In sync context, we're called with either no lock
442 * or with the write lock. If we're not syncing,
443 * we're always called with the read lock held.
444 */
445 boolean_t need_lock =
446 !RW_WRITE_HELD(&dp->dp_config_rwlock) &&
447 dsl_pool_sync_context(dp);
448
449 if (need_lock)
450 rw_enter(&dp->dp_config_rwlock, RW_READER);
451
452 err = dsl_prop_get_ds(ds,
453 "refreservation", sizeof (uint64_t), 1,
454 &ds->ds_reserved, NULL);
455 if (err == 0) {
456 err = dsl_prop_get_ds(ds,
457 "refquota", sizeof (uint64_t), 1,
458 &ds->ds_quota, NULL);
459 }
460
461 if (need_lock)
462 rw_exit(&dp->dp_config_rwlock);
463 } else {
464 ds->ds_reserved = ds->ds_quota = 0;
465 }
466
467 if (err == 0) {
468 winner = dmu_buf_set_user_ie(dbuf, ds, &ds->ds_phys,
469 dsl_dataset_evict);
470 }
471 if (err || winner) {
472 bplist_destroy(&ds->ds_pending_deadlist);
473 dsl_deadlist_close(&ds->ds_deadlist);
474 if (ds->ds_prev)
475 dsl_dataset_drop_ref(ds->ds_prev, ds);
476 dsl_dir_close(ds->ds_dir, ds);
477 mutex_destroy(&ds->ds_lock);
478 mutex_destroy(&ds->ds_recvlock);
479 mutex_destroy(&ds->ds_opening_lock);
480 rw_destroy(&ds->ds_rwlock);
481 cv_destroy(&ds->ds_exclusive_cv);
482 kmem_free(ds, sizeof (dsl_dataset_t));
483 if (err) {
484 dmu_buf_rele(dbuf, tag);
485 return (err);
486 }
487 ds = winner;
488 } else {
489 ds->ds_fsid_guid =
490 unique_insert(ds->ds_phys->ds_fsid_guid);
491 }
492 }
493 ASSERT3P(ds->ds_dbuf, ==, dbuf);
494 ASSERT3P(ds->ds_phys, ==, dbuf->db_data);
495 ASSERT(ds->ds_phys->ds_prev_snap_obj != 0 ||
496 spa_version(dp->dp_spa) < SPA_VERSION_ORIGIN ||
497 dp->dp_origin_snap == NULL || ds == dp->dp_origin_snap);
498 mutex_enter(&ds->ds_lock);
499 if (!dsl_pool_sync_context(dp) && DSL_DATASET_IS_DESTROYED(ds)) {
500 mutex_exit(&ds->ds_lock);
501 dmu_buf_rele(ds->ds_dbuf, tag);
502 return (ENOENT);
503 }
504 mutex_exit(&ds->ds_lock);
505 *dsp = ds;
506 return (0);
507 }
508
509 static int
510 dsl_dataset_hold_ref(dsl_dataset_t *ds, void *tag)
511 {
512 dsl_pool_t *dp = ds->ds_dir->dd_pool;
513
514 /*
515 * In syncing context we don't want the rwlock lock: there
516 * may be an existing writer waiting for sync phase to
517 * finish. We don't need to worry about such writers, since
518 * sync phase is single-threaded, so the writer can't be
519 * doing anything while we are active.
520 */
521 if (dsl_pool_sync_context(dp)) {
522 ASSERT(!DSL_DATASET_IS_DESTROYED(ds));
523 return (0);
524 }
525
526 /*
527 * Normal users will hold the ds_rwlock as a READER until they
528 * are finished (i.e., call dsl_dataset_rele()). "Owners" will
529 * drop their READER lock after they set the ds_owner field.
530 *
531 * If the dataset is being destroyed, the destroy thread will
532 * obtain a WRITER lock for exclusive access after it's done its
533 * open-context work and then change the ds_owner to
534 * dsl_reaper once destruction is assured. So threads
535 * may block here temporarily, until the "destructability" of
536 * the dataset is determined.
537 */
538 ASSERT(!RW_WRITE_HELD(&dp->dp_config_rwlock));
539 mutex_enter(&ds->ds_lock);
540 while (!rw_tryenter(&ds->ds_rwlock, RW_READER)) {
541 rw_exit(&dp->dp_config_rwlock);
542 cv_wait(&ds->ds_exclusive_cv, &ds->ds_lock);
543 if (DSL_DATASET_IS_DESTROYED(ds)) {
544 mutex_exit(&ds->ds_lock);
545 dsl_dataset_drop_ref(ds, tag);
546 rw_enter(&dp->dp_config_rwlock, RW_READER);
547 return (ENOENT);
548 }
549 /*
550 * The dp_config_rwlock lives above the ds_lock. And
551 * we need to check DSL_DATASET_IS_DESTROYED() while
552 * holding the ds_lock, so we have to drop and reacquire
553 * the ds_lock here.
554 */
555 mutex_exit(&ds->ds_lock);
556 rw_enter(&dp->dp_config_rwlock, RW_READER);
557 mutex_enter(&ds->ds_lock);
558 }
559 mutex_exit(&ds->ds_lock);
560 return (0);
561 }
562
563 int
564 dsl_dataset_hold_obj(dsl_pool_t *dp, uint64_t dsobj, void *tag,
565 dsl_dataset_t **dsp)
566 {
567 int err = dsl_dataset_get_ref(dp, dsobj, tag, dsp);
568
569 if (err)
570 return (err);
571 return (dsl_dataset_hold_ref(*dsp, tag));
572 }
573
574 int
575 dsl_dataset_own_obj(dsl_pool_t *dp, uint64_t dsobj, boolean_t inconsistentok,
576 void *tag, dsl_dataset_t **dsp)
577 {
578 int err = dsl_dataset_hold_obj(dp, dsobj, tag, dsp);
579 if (err)
580 return (err);
581 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) {
582 dsl_dataset_rele(*dsp, tag);
583 *dsp = NULL;
584 return (EBUSY);
585 }
586 return (0);
587 }
588
589 int
590 dsl_dataset_hold(const char *name, void *tag, dsl_dataset_t **dsp)
591 {
592 dsl_dir_t *dd;
593 dsl_pool_t *dp;
594 const char *snapname;
595 uint64_t obj;
596 int err = 0;
597
598 err = dsl_dir_open_spa(NULL, name, FTAG, &dd, &snapname);
599 if (err)
600 return (err);
601
602 dp = dd->dd_pool;
603 obj = dd->dd_phys->dd_head_dataset_obj;
604 rw_enter(&dp->dp_config_rwlock, RW_READER);
605 if (obj)
606 err = dsl_dataset_get_ref(dp, obj, tag, dsp);
607 else
608 err = ENOENT;
609 if (err)
610 goto out;
611
612 err = dsl_dataset_hold_ref(*dsp, tag);
613
614 /* we may be looking for a snapshot */
615 if (err == 0 && snapname != NULL) {
616 dsl_dataset_t *ds = NULL;
617
618 if (*snapname++ != '@') {
619 dsl_dataset_rele(*dsp, tag);
620 err = ENOENT;
621 goto out;
622 }
623
624 dprintf("looking for snapshot '%s'\n", snapname);
625 err = dsl_dataset_snap_lookup(*dsp, snapname, &obj);
626 if (err == 0)
627 err = dsl_dataset_get_ref(dp, obj, tag, &ds);
628 dsl_dataset_rele(*dsp, tag);
629
630 ASSERT3U((err == 0), ==, (ds != NULL));
631
632 if (ds) {
633 mutex_enter(&ds->ds_lock);
634 if (ds->ds_snapname[0] == 0)
635 (void) strlcpy(ds->ds_snapname, snapname,
636 sizeof (ds->ds_snapname));
637 mutex_exit(&ds->ds_lock);
638 err = dsl_dataset_hold_ref(ds, tag);
639 *dsp = err ? NULL : ds;
640 }
641 }
642 out:
643 rw_exit(&dp->dp_config_rwlock);
644 dsl_dir_close(dd, FTAG);
645 return (err);
646 }
647
648 int
649 dsl_dataset_own(const char *name, boolean_t inconsistentok,
650 void *tag, dsl_dataset_t **dsp)
651 {
652 int err = dsl_dataset_hold(name, tag, dsp);
653 if (err)
654 return (err);
655 if (!dsl_dataset_tryown(*dsp, inconsistentok, tag)) {
656 dsl_dataset_rele(*dsp, tag);
657 return (EBUSY);
658 }
659 return (0);
660 }
661
662 void
663 dsl_dataset_name(dsl_dataset_t *ds, char *name)
664 {
665 if (ds == NULL) {
666 (void) strcpy(name, "mos");
667 } else {
668 dsl_dir_name(ds->ds_dir, name);
669 VERIFY(0 == dsl_dataset_get_snapname(ds));
670 if (ds->ds_snapname[0]) {
671 (void) strcat(name, "@");
672 /*
673 * We use a "recursive" mutex so that we
674 * can call dprintf_ds() with ds_lock held.
675 */
676 if (!MUTEX_HELD(&ds->ds_lock)) {
677 mutex_enter(&ds->ds_lock);
678 (void) strcat(name, ds->ds_snapname);
679 mutex_exit(&ds->ds_lock);
680 } else {
681 (void) strcat(name, ds->ds_snapname);
682 }
683 }
684 }
685 }
686
687 static int
688 dsl_dataset_namelen(dsl_dataset_t *ds)
689 {
690 int result;
691
692 if (ds == NULL) {
693 result = 3; /* "mos" */
694 } else {
695 result = dsl_dir_namelen(ds->ds_dir);
696 VERIFY(0 == dsl_dataset_get_snapname(ds));
697 if (ds->ds_snapname[0]) {
698 ++result; /* adding one for the @-sign */
699 if (!MUTEX_HELD(&ds->ds_lock)) {
700 mutex_enter(&ds->ds_lock);
701 result += strlen(ds->ds_snapname);
702 mutex_exit(&ds->ds_lock);
703 } else {
704 result += strlen(ds->ds_snapname);
705 }
706 }
707 }
708
709 return (result);
710 }
711
712 void
713 dsl_dataset_drop_ref(dsl_dataset_t *ds, void *tag)
714 {
715 dmu_buf_rele(ds->ds_dbuf, tag);
716 }
717
718 void
719 dsl_dataset_rele(dsl_dataset_t *ds, void *tag)
720 {
721 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool)) {
722 rw_exit(&ds->ds_rwlock);
723 }
724 dsl_dataset_drop_ref(ds, tag);
725 }
726
727 void
728 dsl_dataset_disown(dsl_dataset_t *ds, void *tag)
729 {
730 ASSERT((ds->ds_owner == tag && ds->ds_dbuf) ||
731 (DSL_DATASET_IS_DESTROYED(ds) && ds->ds_dbuf == NULL));
732
733 mutex_enter(&ds->ds_lock);
734 ds->ds_owner = NULL;
735 if (RW_WRITE_HELD(&ds->ds_rwlock)) {
736 rw_exit(&ds->ds_rwlock);
737 cv_broadcast(&ds->ds_exclusive_cv);
738 }
739 mutex_exit(&ds->ds_lock);
740 if (ds->ds_dbuf)
741 dsl_dataset_drop_ref(ds, tag);
742 else
743 dsl_dataset_evict(NULL, ds);
744 }
745
746 boolean_t
747 dsl_dataset_tryown(dsl_dataset_t *ds, boolean_t inconsistentok, void *tag)
748 {
749 boolean_t gotit = FALSE;
750
751 mutex_enter(&ds->ds_lock);
752 if (ds->ds_owner == NULL &&
753 (!DS_IS_INCONSISTENT(ds) || inconsistentok)) {
754 ds->ds_owner = tag;
755 if (!dsl_pool_sync_context(ds->ds_dir->dd_pool))
756 rw_exit(&ds->ds_rwlock);
757 gotit = TRUE;
758 }
759 mutex_exit(&ds->ds_lock);
760 return (gotit);
761 }
762
763 void
764 dsl_dataset_make_exclusive(dsl_dataset_t *ds, void *owner)
765 {
766 ASSERT3P(owner, ==, ds->ds_owner);
767 if (!RW_WRITE_HELD(&ds->ds_rwlock))
768 rw_enter(&ds->ds_rwlock, RW_WRITER);
769 }
770
771 uint64_t
772 dsl_dataset_create_sync_dd(dsl_dir_t *dd, dsl_dataset_t *origin,
773 uint64_t flags, dmu_tx_t *tx)
774 {
775 dsl_pool_t *dp = dd->dd_pool;
776 dmu_buf_t *dbuf;
777 dsl_dataset_phys_t *dsphys;
778 uint64_t dsobj;
779 objset_t *mos = dp->dp_meta_objset;
780
781 if (origin == NULL)
782 origin = dp->dp_origin_snap;
783
784 ASSERT(origin == NULL || origin->ds_dir->dd_pool == dp);
785 ASSERT(origin == NULL || origin->ds_phys->ds_num_children > 0);
786 ASSERT(dmu_tx_is_syncing(tx));
787 ASSERT(dd->dd_phys->dd_head_dataset_obj == 0);
788
789 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
790 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
791 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
792 dmu_buf_will_dirty(dbuf, tx);
793 dsphys = dbuf->db_data;
794 bzero(dsphys, sizeof (dsl_dataset_phys_t));
795 dsphys->ds_dir_obj = dd->dd_object;
796 dsphys->ds_flags = flags;
797 dsphys->ds_fsid_guid = unique_create();
798 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
799 sizeof (dsphys->ds_guid));
800 dsphys->ds_snapnames_zapobj =
801 zap_create_norm(mos, U8_TEXTPREP_TOUPPER, DMU_OT_DSL_DS_SNAP_MAP,
802 DMU_OT_NONE, 0, tx);
803 dsphys->ds_creation_time = gethrestime_sec();
804 dsphys->ds_creation_txg = tx->tx_txg == TXG_INITIAL ? 1 : tx->tx_txg;
805
806 if (origin == NULL) {
807 dsphys->ds_deadlist_obj = dsl_deadlist_alloc(mos, tx);
808 } else {
809 dsl_dataset_t *ohds;
810
811 dsphys->ds_prev_snap_obj = origin->ds_object;
812 dsphys->ds_prev_snap_txg =
813 origin->ds_phys->ds_creation_txg;
814 dsphys->ds_used_bytes =
815 origin->ds_phys->ds_used_bytes;
816 dsphys->ds_compressed_bytes =
817 origin->ds_phys->ds_compressed_bytes;
818 dsphys->ds_uncompressed_bytes =
819 origin->ds_phys->ds_uncompressed_bytes;
820 dsphys->ds_bp = origin->ds_phys->ds_bp;
821 dsphys->ds_flags |= origin->ds_phys->ds_flags;
822
823 dmu_buf_will_dirty(origin->ds_dbuf, tx);
824 origin->ds_phys->ds_num_children++;
825
826 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
827 origin->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ohds));
828 dsphys->ds_deadlist_obj = dsl_deadlist_clone(&ohds->ds_deadlist,
829 dsphys->ds_prev_snap_txg, dsphys->ds_prev_snap_obj, tx);
830 dsl_dataset_rele(ohds, FTAG);
831
832 if (spa_version(dp->dp_spa) >= SPA_VERSION_NEXT_CLONES) {
833 if (origin->ds_phys->ds_next_clones_obj == 0) {
834 origin->ds_phys->ds_next_clones_obj =
835 zap_create(mos,
836 DMU_OT_NEXT_CLONES, DMU_OT_NONE, 0, tx);
837 }
838 VERIFY(0 == zap_add_int(mos,
839 origin->ds_phys->ds_next_clones_obj,
840 dsobj, tx));
841 }
842
843 dmu_buf_will_dirty(dd->dd_dbuf, tx);
844 dd->dd_phys->dd_origin_obj = origin->ds_object;
845 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
846 if (origin->ds_dir->dd_phys->dd_clones == 0) {
847 dmu_buf_will_dirty(origin->ds_dir->dd_dbuf, tx);
848 origin->ds_dir->dd_phys->dd_clones =
849 zap_create(mos,
850 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
851 }
852 VERIFY3U(0, ==, zap_add_int(mos,
853 origin->ds_dir->dd_phys->dd_clones, dsobj, tx));
854 }
855 }
856
857 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
858 dsphys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
859
860 dmu_buf_rele(dbuf, FTAG);
861
862 dmu_buf_will_dirty(dd->dd_dbuf, tx);
863 dd->dd_phys->dd_head_dataset_obj = dsobj;
864
865 return (dsobj);
866 }
867
868 uint64_t
869 dsl_dataset_create_sync(dsl_dir_t *pdd, const char *lastname,
870 dsl_dataset_t *origin, uint64_t flags, cred_t *cr, dmu_tx_t *tx)
871 {
872 dsl_pool_t *dp = pdd->dd_pool;
873 uint64_t dsobj, ddobj;
874 dsl_dir_t *dd;
875
876 ASSERT(lastname[0] != '@');
877
878 ddobj = dsl_dir_create_sync(dp, pdd, lastname, tx);
879 VERIFY(0 == dsl_dir_open_obj(dp, ddobj, lastname, FTAG, &dd));
880
881 dsobj = dsl_dataset_create_sync_dd(dd, origin, flags, tx);
882
883 dsl_deleg_set_create_perms(dd, tx, cr);
884
885 dsl_dir_close(dd, FTAG);
886
887 /*
888 * If we are creating a clone, make sure we zero out any stale
889 * data from the origin snapshots zil header.
890 */
891 if (origin != NULL) {
892 dsl_dataset_t *ds;
893 objset_t *os;
894
895 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds));
896 VERIFY3U(0, ==, dmu_objset_from_ds(ds, &os));
897 bzero(&os->os_zil_header, sizeof (os->os_zil_header));
898 dsl_dataset_dirty(ds, tx);
899 dsl_dataset_rele(ds, FTAG);
900 }
901
902 return (dsobj);
903 }
904
905 /*
906 * The snapshots must all be in the same pool.
907 */
908 int
909 dmu_snapshots_destroy_nvl(nvlist_t *snaps, boolean_t defer, char *failed)
910 {
911 int err;
912 dsl_sync_task_t *dst;
913 spa_t *spa;
914 nvpair_t *pair;
915 dsl_sync_task_group_t *dstg;
916
917 pair = nvlist_next_nvpair(snaps, NULL);
918 if (pair == NULL)
919 return (0);
920
921 err = spa_open(nvpair_name(pair), &spa, FTAG);
922 if (err)
923 return (err);
924 dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
925
926 for (pair = nvlist_next_nvpair(snaps, NULL); pair != NULL;
927 pair = nvlist_next_nvpair(snaps, pair)) {
928 dsl_dataset_t *ds;
929 int err;
930
931 err = dsl_dataset_own(nvpair_name(pair), B_TRUE, dstg, &ds);
932 if (err == 0) {
933 struct dsl_ds_destroyarg *dsda;
934
935 dsl_dataset_make_exclusive(ds, dstg);
936 dsda = kmem_zalloc(sizeof (struct dsl_ds_destroyarg),
937 KM_SLEEP);
938 dsda->ds = ds;
939 dsda->defer = defer;
940 dsl_sync_task_create(dstg, dsl_dataset_destroy_check,
941 dsl_dataset_destroy_sync, dsda, dstg, 0);
942 } else if (err == ENOENT) {
943 err = 0;
944 } else {
945 (void) strcpy(failed, nvpair_name(pair));
946 break;
947 }
948 }
949
950 if (err == 0)
951 err = dsl_sync_task_group_wait(dstg);
952
953 for (dst = list_head(&dstg->dstg_tasks); dst;
954 dst = list_next(&dstg->dstg_tasks, dst)) {
955 struct dsl_ds_destroyarg *dsda = dst->dst_arg1;
956 dsl_dataset_t *ds = dsda->ds;
957
958 /*
959 * Return the file system name that triggered the error
960 */
961 if (dst->dst_err) {
962 dsl_dataset_name(ds, failed);
963 }
964 ASSERT3P(dsda->rm_origin, ==, NULL);
965 dsl_dataset_disown(ds, dstg);
966 kmem_free(dsda, sizeof (struct dsl_ds_destroyarg));
967 }
968
969 dsl_sync_task_group_destroy(dstg);
970 spa_close(spa, FTAG);
971 return (err);
972
973 }
974
975 static boolean_t
976 dsl_dataset_might_destroy_origin(dsl_dataset_t *ds)
977 {
978 boolean_t might_destroy = B_FALSE;
979
980 mutex_enter(&ds->ds_lock);
981 if (ds->ds_phys->ds_num_children == 2 && ds->ds_userrefs == 0 &&
982 DS_IS_DEFER_DESTROY(ds))
983 might_destroy = B_TRUE;
984 mutex_exit(&ds->ds_lock);
985
986 return (might_destroy);
987 }
988
989 /*
990 * If we're removing a clone, and these three conditions are true:
991 * 1) the clone's origin has no other children
992 * 2) the clone's origin has no user references
993 * 3) the clone's origin has been marked for deferred destruction
994 * Then, prepare to remove the origin as part of this sync task group.
995 */
996 static int
997 dsl_dataset_origin_rm_prep(struct dsl_ds_destroyarg *dsda, void *tag)
998 {
999 dsl_dataset_t *ds = dsda->ds;
1000 dsl_dataset_t *origin = ds->ds_prev;
1001
1002 if (dsl_dataset_might_destroy_origin(origin)) {
1003 char *name;
1004 int namelen;
1005 int error;
1006
1007 namelen = dsl_dataset_namelen(origin) + 1;
1008 name = kmem_alloc(namelen, KM_SLEEP);
1009 dsl_dataset_name(origin, name);
1010 #ifdef _KERNEL
1011 error = zfs_unmount_snap(name, NULL);
1012 if (error) {
1013 kmem_free(name, namelen);
1014 return (error);
1015 }
1016 #endif
1017 error = dsl_dataset_own(name, B_TRUE, tag, &origin);
1018 kmem_free(name, namelen);
1019 if (error)
1020 return (error);
1021 dsda->rm_origin = origin;
1022 dsl_dataset_make_exclusive(origin, tag);
1023 }
1024
1025 return (0);
1026 }
1027
1028 /*
1029 * ds must be opened as OWNER. On return (whether successful or not),
1030 * ds will be closed and caller can no longer dereference it.
1031 */
1032 int
1033 dsl_dataset_destroy(dsl_dataset_t *ds, void *tag, boolean_t defer)
1034 {
1035 int err;
1036 dsl_sync_task_group_t *dstg;
1037 objset_t *os;
1038 dsl_dir_t *dd;
1039 uint64_t obj;
1040 struct dsl_ds_destroyarg dsda = { 0 };
1041 dsl_dataset_t dummy_ds = { 0 };
1042
1043 dsda.ds = ds;
1044
1045 if (dsl_dataset_is_snapshot(ds)) {
1046 /* Destroying a snapshot is simpler */
1047 dsl_dataset_make_exclusive(ds, tag);
1048
1049 dsda.defer = defer;
1050 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
1051 dsl_dataset_destroy_check, dsl_dataset_destroy_sync,
1052 &dsda, tag, 0);
1053 ASSERT3P(dsda.rm_origin, ==, NULL);
1054 goto out;
1055 } else if (defer) {
1056 err = EINVAL;
1057 goto out;
1058 }
1059
1060 dd = ds->ds_dir;
1061 dummy_ds.ds_dir = dd;
1062 dummy_ds.ds_object = ds->ds_object;
1063
1064 /*
1065 * Check for errors and mark this ds as inconsistent, in
1066 * case we crash while freeing the objects.
1067 */
1068 err = dsl_sync_task_do(dd->dd_pool, dsl_dataset_destroy_begin_check,
1069 dsl_dataset_destroy_begin_sync, ds, NULL, 0);
1070 if (err)
1071 goto out;
1072
1073 err = dmu_objset_from_ds(ds, &os);
1074 if (err)
1075 goto out;
1076
1077 /*
1078 * remove the objects in open context, so that we won't
1079 * have too much to do in syncing context.
1080 */
1081 for (obj = 0; err == 0; err = dmu_object_next(os, &obj, FALSE,
1082 ds->ds_phys->ds_prev_snap_txg)) {
1083 /*
1084 * Ignore errors, if there is not enough disk space
1085 * we will deal with it in dsl_dataset_destroy_sync().
1086 */
1087 (void) dmu_free_object(os, obj);
1088 }
1089 if (err != ESRCH)
1090 goto out;
1091
1092 /*
1093 * Only the ZIL knows how to free log blocks.
1094 */
1095 zil_destroy(dmu_objset_zil(os), B_FALSE);
1096
1097 /*
1098 * Sync out all in-flight IO.
1099 */
1100 txg_wait_synced(dd->dd_pool, 0);
1101
1102 /*
1103 * If we managed to free all the objects in open
1104 * context, the user space accounting should be zero.
1105 */
1106 if (ds->ds_phys->ds_bp.blk_fill == 0 &&
1107 dmu_objset_userused_enabled(os)) {
1108 uint64_t count;
1109
1110 ASSERT(zap_count(os, DMU_USERUSED_OBJECT, &count) != 0 ||
1111 count == 0);
1112 ASSERT(zap_count(os, DMU_GROUPUSED_OBJECT, &count) != 0 ||
1113 count == 0);
1114 }
1115
1116 rw_enter(&dd->dd_pool->dp_config_rwlock, RW_READER);
1117 err = dsl_dir_open_obj(dd->dd_pool, dd->dd_object, NULL, FTAG, &dd);
1118 rw_exit(&dd->dd_pool->dp_config_rwlock);
1119
1120 if (err)
1121 goto out;
1122
1123 /*
1124 * Blow away the dsl_dir + head dataset.
1125 */
1126 dsl_dataset_make_exclusive(ds, tag);
1127 /*
1128 * If we're removing a clone, we might also need to remove its
1129 * origin.
1130 */
1131 do {
1132 dsda.need_prep = B_FALSE;
1133 if (dsl_dir_is_clone(dd)) {
1134 err = dsl_dataset_origin_rm_prep(&dsda, tag);
1135 if (err) {
1136 dsl_dir_close(dd, FTAG);
1137 goto out;
1138 }
1139 }
1140
1141 dstg = dsl_sync_task_group_create(ds->ds_dir->dd_pool);
1142 dsl_sync_task_create(dstg, dsl_dataset_destroy_check,
1143 dsl_dataset_destroy_sync, &dsda, tag, 0);
1144 dsl_sync_task_create(dstg, dsl_dir_destroy_check,
1145 dsl_dir_destroy_sync, &dummy_ds, FTAG, 0);
1146 err = dsl_sync_task_group_wait(dstg);
1147 dsl_sync_task_group_destroy(dstg);
1148
1149 /*
1150 * We could be racing against 'zfs release' or 'zfs destroy -d'
1151 * on the origin snap, in which case we can get EBUSY if we
1152 * needed to destroy the origin snap but were not ready to
1153 * do so.
1154 */
1155 if (dsda.need_prep) {
1156 ASSERT(err == EBUSY);
1157 ASSERT(dsl_dir_is_clone(dd));
1158 ASSERT(dsda.rm_origin == NULL);
1159 }
1160 } while (dsda.need_prep);
1161
1162 if (dsda.rm_origin != NULL)
1163 dsl_dataset_disown(dsda.rm_origin, tag);
1164
1165 /* if it is successful, dsl_dir_destroy_sync will close the dd */
1166 if (err)
1167 dsl_dir_close(dd, FTAG);
1168 out:
1169 dsl_dataset_disown(ds, tag);
1170 return (err);
1171 }
1172
1173 blkptr_t *
1174 dsl_dataset_get_blkptr(dsl_dataset_t *ds)
1175 {
1176 return (&ds->ds_phys->ds_bp);
1177 }
1178
1179 void
1180 dsl_dataset_set_blkptr(dsl_dataset_t *ds, blkptr_t *bp, dmu_tx_t *tx)
1181 {
1182 ASSERT(dmu_tx_is_syncing(tx));
1183 /* If it's the meta-objset, set dp_meta_rootbp */
1184 if (ds == NULL) {
1185 tx->tx_pool->dp_meta_rootbp = *bp;
1186 } else {
1187 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1188 ds->ds_phys->ds_bp = *bp;
1189 }
1190 }
1191
1192 spa_t *
1193 dsl_dataset_get_spa(dsl_dataset_t *ds)
1194 {
1195 return (ds->ds_dir->dd_pool->dp_spa);
1196 }
1197
1198 void
1199 dsl_dataset_dirty(dsl_dataset_t *ds, dmu_tx_t *tx)
1200 {
1201 dsl_pool_t *dp;
1202
1203 if (ds == NULL) /* this is the meta-objset */
1204 return;
1205
1206 ASSERT(ds->ds_objset != NULL);
1207
1208 if (ds->ds_phys->ds_next_snap_obj != 0)
1209 panic("dirtying snapshot!");
1210
1211 dp = ds->ds_dir->dd_pool;
1212
1213 if (txg_list_add(&dp->dp_dirty_datasets, ds, tx->tx_txg) == 0) {
1214 /* up the hold count until we can be written out */
1215 dmu_buf_add_ref(ds->ds_dbuf, ds);
1216 }
1217 }
1218
1219 /*
1220 * The unique space in the head dataset can be calculated by subtracting
1221 * the space used in the most recent snapshot, that is still being used
1222 * in this file system, from the space currently in use. To figure out
1223 * the space in the most recent snapshot still in use, we need to take
1224 * the total space used in the snapshot and subtract out the space that
1225 * has been freed up since the snapshot was taken.
1226 */
1227 static void
1228 dsl_dataset_recalc_head_uniq(dsl_dataset_t *ds)
1229 {
1230 uint64_t mrs_used;
1231 uint64_t dlused, dlcomp, dluncomp;
1232
1233 ASSERT(!dsl_dataset_is_snapshot(ds));
1234
1235 if (ds->ds_phys->ds_prev_snap_obj != 0)
1236 mrs_used = ds->ds_prev->ds_phys->ds_used_bytes;
1237 else
1238 mrs_used = 0;
1239
1240 dsl_deadlist_space(&ds->ds_deadlist, &dlused, &dlcomp, &dluncomp);
1241
1242 ASSERT3U(dlused, <=, mrs_used);
1243 ds->ds_phys->ds_unique_bytes =
1244 ds->ds_phys->ds_used_bytes - (mrs_used - dlused);
1245
1246 if (spa_version(ds->ds_dir->dd_pool->dp_spa) >=
1247 SPA_VERSION_UNIQUE_ACCURATE)
1248 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
1249 }
1250
1251 struct killarg {
1252 dsl_dataset_t *ds;
1253 dmu_tx_t *tx;
1254 };
1255
1256 /* ARGSUSED */
1257 static int
1258 kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, arc_buf_t *pbuf,
1259 const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg)
1260 {
1261 struct killarg *ka = arg;
1262 dmu_tx_t *tx = ka->tx;
1263
1264 if (bp == NULL)
1265 return (0);
1266
1267 if (zb->zb_level == ZB_ZIL_LEVEL) {
1268 ASSERT(zilog != NULL);
1269 /*
1270 * It's a block in the intent log. It has no
1271 * accounting, so just free it.
1272 */
1273 dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp);
1274 } else {
1275 ASSERT(zilog == NULL);
1276 ASSERT3U(bp->blk_birth, >, ka->ds->ds_phys->ds_prev_snap_txg);
1277 (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE);
1278 }
1279
1280 return (0);
1281 }
1282
1283 /* ARGSUSED */
1284 static int
1285 dsl_dataset_destroy_begin_check(void *arg1, void *arg2, dmu_tx_t *tx)
1286 {
1287 dsl_dataset_t *ds = arg1;
1288 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1289 uint64_t count;
1290 int err;
1291
1292 /*
1293 * Can't delete a head dataset if there are snapshots of it.
1294 * (Except if the only snapshots are from the branch we cloned
1295 * from.)
1296 */
1297 if (ds->ds_prev != NULL &&
1298 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object)
1299 return (EBUSY);
1300
1301 /*
1302 * This is really a dsl_dir thing, but check it here so that
1303 * we'll be less likely to leave this dataset inconsistent &
1304 * nearly destroyed.
1305 */
1306 err = zap_count(mos, ds->ds_dir->dd_phys->dd_child_dir_zapobj, &count);
1307 if (err)
1308 return (err);
1309 if (count != 0)
1310 return (EEXIST);
1311
1312 return (0);
1313 }
1314
1315 /* ARGSUSED */
1316 static void
1317 dsl_dataset_destroy_begin_sync(void *arg1, void *arg2, dmu_tx_t *tx)
1318 {
1319 dsl_dataset_t *ds = arg1;
1320 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1321
1322 /* Mark it as inconsistent on-disk, in case we crash */
1323 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1324 ds->ds_phys->ds_flags |= DS_FLAG_INCONSISTENT;
1325
1326 spa_history_log_internal(LOG_DS_DESTROY_BEGIN, dp->dp_spa, tx,
1327 "dataset = %llu", ds->ds_object);
1328 }
1329
1330 static int
1331 dsl_dataset_origin_check(struct dsl_ds_destroyarg *dsda, void *tag,
1332 dmu_tx_t *tx)
1333 {
1334 dsl_dataset_t *ds = dsda->ds;
1335 dsl_dataset_t *ds_prev = ds->ds_prev;
1336
1337 if (dsl_dataset_might_destroy_origin(ds_prev)) {
1338 struct dsl_ds_destroyarg ndsda = {0};
1339
1340 /*
1341 * If we're not prepared to remove the origin, don't remove
1342 * the clone either.
1343 */
1344 if (dsda->rm_origin == NULL) {
1345 dsda->need_prep = B_TRUE;
1346 return (EBUSY);
1347 }
1348
1349 ndsda.ds = ds_prev;
1350 ndsda.is_origin_rm = B_TRUE;
1351 return (dsl_dataset_destroy_check(&ndsda, tag, tx));
1352 }
1353
1354 /*
1355 * If we're not going to remove the origin after all,
1356 * undo the open context setup.
1357 */
1358 if (dsda->rm_origin != NULL) {
1359 dsl_dataset_disown(dsda->rm_origin, tag);
1360 dsda->rm_origin = NULL;
1361 }
1362
1363 return (0);
1364 }
1365
1366 /*
1367 * If you add new checks here, you may need to add
1368 * additional checks to the "temporary" case in
1369 * snapshot_check() in dmu_objset.c.
1370 */
1371 /* ARGSUSED */
1372 int
1373 dsl_dataset_destroy_check(void *arg1, void *arg2, dmu_tx_t *tx)
1374 {
1375 struct dsl_ds_destroyarg *dsda = arg1;
1376 dsl_dataset_t *ds = dsda->ds;
1377
1378 /* we have an owner hold, so noone else can destroy us */
1379 ASSERT(!DSL_DATASET_IS_DESTROYED(ds));
1380
1381 /*
1382 * Only allow deferred destroy on pools that support it.
1383 * NOTE: deferred destroy is only supported on snapshots.
1384 */
1385 if (dsda->defer) {
1386 if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
1387 SPA_VERSION_USERREFS)
1388 return (ENOTSUP);
1389 ASSERT(dsl_dataset_is_snapshot(ds));
1390 return (0);
1391 }
1392
1393 /*
1394 * Can't delete a head dataset if there are snapshots of it.
1395 * (Except if the only snapshots are from the branch we cloned
1396 * from.)
1397 */
1398 if (ds->ds_prev != NULL &&
1399 ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object)
1400 return (EBUSY);
1401
1402 /*
1403 * If we made changes this txg, traverse_dsl_dataset won't find
1404 * them. Try again.
1405 */
1406 if (ds->ds_phys->ds_bp.blk_birth >= tx->tx_txg)
1407 return (EAGAIN);
1408
1409 if (dsl_dataset_is_snapshot(ds)) {
1410 /*
1411 * If this snapshot has an elevated user reference count,
1412 * we can't destroy it yet.
1413 */
1414 if (ds->ds_userrefs > 0 && !dsda->releasing)
1415 return (EBUSY);
1416
1417 mutex_enter(&ds->ds_lock);
1418 /*
1419 * Can't delete a branch point. However, if we're destroying
1420 * a clone and removing its origin due to it having a user
1421 * hold count of 0 and having been marked for deferred destroy,
1422 * it's OK for the origin to have a single clone.
1423 */
1424 if (ds->ds_phys->ds_num_children >
1425 (dsda->is_origin_rm ? 2 : 1)) {
1426 mutex_exit(&ds->ds_lock);
1427 return (EEXIST);
1428 }
1429 mutex_exit(&ds->ds_lock);
1430 } else if (dsl_dir_is_clone(ds->ds_dir)) {
1431 return (dsl_dataset_origin_check(dsda, arg2, tx));
1432 }
1433
1434 /* XXX we should do some i/o error checking... */
1435 return (0);
1436 }
1437
1438 struct refsarg {
1439 kmutex_t lock;
1440 boolean_t gone;
1441 kcondvar_t cv;
1442 };
1443
1444 /* ARGSUSED */
1445 static void
1446 dsl_dataset_refs_gone(dmu_buf_t *db, void *argv)
1447 {
1448 struct refsarg *arg = argv;
1449
1450 mutex_enter(&arg->lock);
1451 arg->gone = TRUE;
1452 cv_signal(&arg->cv);
1453 mutex_exit(&arg->lock);
1454 }
1455
1456 static void
1457 dsl_dataset_drain_refs(dsl_dataset_t *ds, void *tag)
1458 {
1459 struct refsarg arg;
1460
1461 mutex_init(&arg.lock, NULL, MUTEX_DEFAULT, NULL);
1462 cv_init(&arg.cv, NULL, CV_DEFAULT, NULL);
1463 arg.gone = FALSE;
1464 (void) dmu_buf_update_user(ds->ds_dbuf, ds, &arg, &ds->ds_phys,
1465 dsl_dataset_refs_gone);
1466 dmu_buf_rele(ds->ds_dbuf, tag);
1467 mutex_enter(&arg.lock);
1468 while (!arg.gone)
1469 cv_wait(&arg.cv, &arg.lock);
1470 ASSERT(arg.gone);
1471 mutex_exit(&arg.lock);
1472 ds->ds_dbuf = NULL;
1473 ds->ds_phys = NULL;
1474 mutex_destroy(&arg.lock);
1475 cv_destroy(&arg.cv);
1476 }
1477
1478 static void
1479 remove_from_next_clones(dsl_dataset_t *ds, uint64_t obj, dmu_tx_t *tx)
1480 {
1481 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1482 uint64_t count;
1483 int err;
1484
1485 ASSERT(ds->ds_phys->ds_num_children >= 2);
1486 err = zap_remove_int(mos, ds->ds_phys->ds_next_clones_obj, obj, tx);
1487 /*
1488 * The err should not be ENOENT, but a bug in a previous version
1489 * of the code could cause upgrade_clones_cb() to not set
1490 * ds_next_snap_obj when it should, leading to a missing entry.
1491 * If we knew that the pool was created after
1492 * SPA_VERSION_NEXT_CLONES, we could assert that it isn't
1493 * ENOENT. However, at least we can check that we don't have
1494 * too many entries in the next_clones_obj even after failing to
1495 * remove this one.
1496 */
1497 if (err != ENOENT) {
1498 VERIFY3U(err, ==, 0);
1499 }
1500 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj,
1501 &count));
1502 ASSERT3U(count, <=, ds->ds_phys->ds_num_children - 2);
1503 }
1504
1505 static void
1506 dsl_dataset_remove_clones_key(dsl_dataset_t *ds, uint64_t mintxg, dmu_tx_t *tx)
1507 {
1508 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
1509 zap_cursor_t zc;
1510 zap_attribute_t za;
1511
1512 /*
1513 * If it is the old version, dd_clones doesn't exist so we can't
1514 * find the clones, but deadlist_remove_key() is a no-op so it
1515 * doesn't matter.
1516 */
1517 if (ds->ds_dir->dd_phys->dd_clones == 0)
1518 return;
1519
1520 for (zap_cursor_init(&zc, mos, ds->ds_dir->dd_phys->dd_clones);
1521 zap_cursor_retrieve(&zc, &za) == 0;
1522 zap_cursor_advance(&zc)) {
1523 dsl_dataset_t *clone;
1524
1525 VERIFY3U(0, ==, dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
1526 za.za_first_integer, FTAG, &clone));
1527 if (clone->ds_dir->dd_origin_txg > mintxg) {
1528 dsl_deadlist_remove_key(&clone->ds_deadlist,
1529 mintxg, tx);
1530 dsl_dataset_remove_clones_key(clone, mintxg, tx);
1531 }
1532 dsl_dataset_rele(clone, FTAG);
1533 }
1534 zap_cursor_fini(&zc);
1535 }
1536
1537 struct process_old_arg {
1538 dsl_dataset_t *ds;
1539 dsl_dataset_t *ds_prev;
1540 boolean_t after_branch_point;
1541 zio_t *pio;
1542 uint64_t used, comp, uncomp;
1543 };
1544
1545 static int
1546 process_old_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
1547 {
1548 struct process_old_arg *poa = arg;
1549 dsl_pool_t *dp = poa->ds->ds_dir->dd_pool;
1550
1551 if (bp->blk_birth <= poa->ds->ds_phys->ds_prev_snap_txg) {
1552 dsl_deadlist_insert(&poa->ds->ds_deadlist, bp, tx);
1553 if (poa->ds_prev && !poa->after_branch_point &&
1554 bp->blk_birth >
1555 poa->ds_prev->ds_phys->ds_prev_snap_txg) {
1556 poa->ds_prev->ds_phys->ds_unique_bytes +=
1557 bp_get_dsize_sync(dp->dp_spa, bp);
1558 }
1559 } else {
1560 poa->used += bp_get_dsize_sync(dp->dp_spa, bp);
1561 poa->comp += BP_GET_PSIZE(bp);
1562 poa->uncomp += BP_GET_UCSIZE(bp);
1563 dsl_free_sync(poa->pio, dp, tx->tx_txg, bp);
1564 }
1565 return (0);
1566 }
1567
1568 static void
1569 process_old_deadlist(dsl_dataset_t *ds, dsl_dataset_t *ds_prev,
1570 dsl_dataset_t *ds_next, boolean_t after_branch_point, dmu_tx_t *tx)
1571 {
1572 struct process_old_arg poa = { 0 };
1573 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1574 objset_t *mos = dp->dp_meta_objset;
1575
1576 ASSERT(ds->ds_deadlist.dl_oldfmt);
1577 ASSERT(ds_next->ds_deadlist.dl_oldfmt);
1578
1579 poa.ds = ds;
1580 poa.ds_prev = ds_prev;
1581 poa.after_branch_point = after_branch_point;
1582 poa.pio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
1583 VERIFY3U(0, ==, bpobj_iterate(&ds_next->ds_deadlist.dl_bpobj,
1584 process_old_cb, &poa, tx));
1585 VERIFY3U(zio_wait(poa.pio), ==, 0);
1586 ASSERT3U(poa.used, ==, ds->ds_phys->ds_unique_bytes);
1587
1588 /* change snapused */
1589 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
1590 -poa.used, -poa.comp, -poa.uncomp, tx);
1591
1592 /* swap next's deadlist to our deadlist */
1593 dsl_deadlist_close(&ds->ds_deadlist);
1594 dsl_deadlist_close(&ds_next->ds_deadlist);
1595 SWITCH64(ds_next->ds_phys->ds_deadlist_obj,
1596 ds->ds_phys->ds_deadlist_obj);
1597 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj);
1598 dsl_deadlist_open(&ds_next->ds_deadlist, mos,
1599 ds_next->ds_phys->ds_deadlist_obj);
1600 }
1601
1602 void
1603 dsl_dataset_destroy_sync(void *arg1, void *tag, dmu_tx_t *tx)
1604 {
1605 struct dsl_ds_destroyarg *dsda = arg1;
1606 dsl_dataset_t *ds = dsda->ds;
1607 int err;
1608 int after_branch_point = FALSE;
1609 dsl_pool_t *dp = ds->ds_dir->dd_pool;
1610 objset_t *mos = dp->dp_meta_objset;
1611 dsl_dataset_t *ds_prev = NULL;
1612 boolean_t wont_destroy;
1613 uint64_t obj;
1614
1615 wont_destroy = (dsda->defer &&
1616 (ds->ds_userrefs > 0 || ds->ds_phys->ds_num_children > 1));
1617
1618 ASSERT(ds->ds_owner || wont_destroy);
1619 ASSERT(dsda->defer || ds->ds_phys->ds_num_children <= 1);
1620 ASSERT(ds->ds_prev == NULL ||
1621 ds->ds_prev->ds_phys->ds_next_snap_obj != ds->ds_object);
1622 ASSERT3U(ds->ds_phys->ds_bp.blk_birth, <=, tx->tx_txg);
1623
1624 if (wont_destroy) {
1625 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
1626 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1627 ds->ds_phys->ds_flags |= DS_FLAG_DEFER_DESTROY;
1628 return;
1629 }
1630
1631 /* signal any waiters that this dataset is going away */
1632 mutex_enter(&ds->ds_lock);
1633 ds->ds_owner = dsl_reaper;
1634 cv_broadcast(&ds->ds_exclusive_cv);
1635 mutex_exit(&ds->ds_lock);
1636
1637 /* Remove our reservation */
1638 if (ds->ds_reserved != 0) {
1639 dsl_prop_setarg_t psa;
1640 uint64_t value = 0;
1641
1642 dsl_prop_setarg_init_uint64(&psa, "refreservation",
1643 (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED),
1644 &value);
1645 psa.psa_effective_value = 0; /* predict default value */
1646
1647 dsl_dataset_set_reservation_sync(ds, &psa, tx);
1648 ASSERT3U(ds->ds_reserved, ==, 0);
1649 }
1650
1651 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
1652
1653 dsl_scan_ds_destroyed(ds, tx);
1654
1655 obj = ds->ds_object;
1656
1657 if (ds->ds_phys->ds_prev_snap_obj != 0) {
1658 if (ds->ds_prev) {
1659 ds_prev = ds->ds_prev;
1660 } else {
1661 VERIFY(0 == dsl_dataset_hold_obj(dp,
1662 ds->ds_phys->ds_prev_snap_obj, FTAG, &ds_prev));
1663 }
1664 after_branch_point =
1665 (ds_prev->ds_phys->ds_next_snap_obj != obj);
1666
1667 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx);
1668 if (after_branch_point &&
1669 ds_prev->ds_phys->ds_next_clones_obj != 0) {
1670 remove_from_next_clones(ds_prev, obj, tx);
1671 if (ds->ds_phys->ds_next_snap_obj != 0) {
1672 VERIFY(0 == zap_add_int(mos,
1673 ds_prev->ds_phys->ds_next_clones_obj,
1674 ds->ds_phys->ds_next_snap_obj, tx));
1675 }
1676 }
1677 if (after_branch_point &&
1678 ds->ds_phys->ds_next_snap_obj == 0) {
1679 /* This clone is toast. */
1680 ASSERT(ds_prev->ds_phys->ds_num_children > 1);
1681 ds_prev->ds_phys->ds_num_children--;
1682
1683 /*
1684 * If the clone's origin has no other clones, no
1685 * user holds, and has been marked for deferred
1686 * deletion, then we should have done the necessary
1687 * destroy setup for it.
1688 */
1689 if (ds_prev->ds_phys->ds_num_children == 1 &&
1690 ds_prev->ds_userrefs == 0 &&
1691 DS_IS_DEFER_DESTROY(ds_prev)) {
1692 ASSERT3P(dsda->rm_origin, !=, NULL);
1693 } else {
1694 ASSERT3P(dsda->rm_origin, ==, NULL);
1695 }
1696 } else if (!after_branch_point) {
1697 ds_prev->ds_phys->ds_next_snap_obj =
1698 ds->ds_phys->ds_next_snap_obj;
1699 }
1700 }
1701
1702 if (dsl_dataset_is_snapshot(ds)) {
1703 dsl_dataset_t *ds_next;
1704 uint64_t old_unique;
1705 uint64_t used = 0, comp = 0, uncomp = 0;
1706
1707 VERIFY(0 == dsl_dataset_hold_obj(dp,
1708 ds->ds_phys->ds_next_snap_obj, FTAG, &ds_next));
1709 ASSERT3U(ds_next->ds_phys->ds_prev_snap_obj, ==, obj);
1710
1711 old_unique = ds_next->ds_phys->ds_unique_bytes;
1712
1713 dmu_buf_will_dirty(ds_next->ds_dbuf, tx);
1714 ds_next->ds_phys->ds_prev_snap_obj =
1715 ds->ds_phys->ds_prev_snap_obj;
1716 ds_next->ds_phys->ds_prev_snap_txg =
1717 ds->ds_phys->ds_prev_snap_txg;
1718 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
1719 ds_prev ? ds_prev->ds_phys->ds_creation_txg : 0);
1720
1721
1722 if (ds_next->ds_deadlist.dl_oldfmt) {
1723 process_old_deadlist(ds, ds_prev, ds_next,
1724 after_branch_point, tx);
1725 } else {
1726 /* Adjust prev's unique space. */
1727 if (ds_prev && !after_branch_point) {
1728 dsl_deadlist_space_range(&ds_next->ds_deadlist,
1729 ds_prev->ds_phys->ds_prev_snap_txg,
1730 ds->ds_phys->ds_prev_snap_txg,
1731 &used, &comp, &uncomp);
1732 ds_prev->ds_phys->ds_unique_bytes += used;
1733 }
1734
1735 /* Adjust snapused. */
1736 dsl_deadlist_space_range(&ds_next->ds_deadlist,
1737 ds->ds_phys->ds_prev_snap_txg, UINT64_MAX,
1738 &used, &comp, &uncomp);
1739 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
1740 -used, -comp, -uncomp, tx);
1741
1742 /* Move blocks to be freed to pool's free list. */
1743 dsl_deadlist_move_bpobj(&ds_next->ds_deadlist,
1744 &dp->dp_free_bpobj, ds->ds_phys->ds_prev_snap_txg,
1745 tx);
1746 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir,
1747 DD_USED_HEAD, used, comp, uncomp, tx);
1748 dsl_dir_dirty(tx->tx_pool->dp_free_dir, tx);
1749
1750 /* Merge our deadlist into next's and free it. */
1751 dsl_deadlist_merge(&ds_next->ds_deadlist,
1752 ds->ds_phys->ds_deadlist_obj, tx);
1753 }
1754 dsl_deadlist_close(&ds->ds_deadlist);
1755 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx);
1756
1757 /* Collapse range in clone heads */
1758 dsl_dataset_remove_clones_key(ds,
1759 ds->ds_phys->ds_creation_txg, tx);
1760
1761 if (dsl_dataset_is_snapshot(ds_next)) {
1762 dsl_dataset_t *ds_nextnext;
1763
1764 /*
1765 * Update next's unique to include blocks which
1766 * were previously shared by only this snapshot
1767 * and it. Those blocks will be born after the
1768 * prev snap and before this snap, and will have
1769 * died after the next snap and before the one
1770 * after that (ie. be on the snap after next's
1771 * deadlist).
1772 */
1773 VERIFY(0 == dsl_dataset_hold_obj(dp,
1774 ds_next->ds_phys->ds_next_snap_obj,
1775 FTAG, &ds_nextnext));
1776 dsl_deadlist_space_range(&ds_nextnext->ds_deadlist,
1777 ds->ds_phys->ds_prev_snap_txg,
1778 ds->ds_phys->ds_creation_txg,
1779 &used, &comp, &uncomp);
1780 ds_next->ds_phys->ds_unique_bytes += used;
1781 dsl_dataset_rele(ds_nextnext, FTAG);
1782 ASSERT3P(ds_next->ds_prev, ==, NULL);
1783
1784 /* Collapse range in this head. */
1785 dsl_dataset_t *hds;
1786 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
1787 ds->ds_dir->dd_phys->dd_head_dataset_obj,
1788 FTAG, &hds));
1789 dsl_deadlist_remove_key(&hds->ds_deadlist,
1790 ds->ds_phys->ds_creation_txg, tx);
1791 dsl_dataset_rele(hds, FTAG);
1792
1793 } else {
1794 ASSERT3P(ds_next->ds_prev, ==, ds);
1795 dsl_dataset_drop_ref(ds_next->ds_prev, ds_next);
1796 ds_next->ds_prev = NULL;
1797 if (ds_prev) {
1798 VERIFY(0 == dsl_dataset_get_ref(dp,
1799 ds->ds_phys->ds_prev_snap_obj,
1800 ds_next, &ds_next->ds_prev));
1801 }
1802
1803 dsl_dataset_recalc_head_uniq(ds_next);
1804
1805 /*
1806 * Reduce the amount of our unconsmed refreservation
1807 * being charged to our parent by the amount of
1808 * new unique data we have gained.
1809 */
1810 if (old_unique < ds_next->ds_reserved) {
1811 int64_t mrsdelta;
1812 uint64_t new_unique =
1813 ds_next->ds_phys->ds_unique_bytes;
1814
1815 ASSERT(old_unique <= new_unique);
1816 mrsdelta = MIN(new_unique - old_unique,
1817 ds_next->ds_reserved - old_unique);
1818 dsl_dir_diduse_space(ds->ds_dir,
1819 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx);
1820 }
1821 }
1822 dsl_dataset_rele(ds_next, FTAG);
1823 } else {
1824 /*
1825 * There's no next snapshot, so this is a head dataset.
1826 * Destroy the deadlist. Unless it's a clone, the
1827 * deadlist should be empty. (If it's a clone, it's
1828 * safe to ignore the deadlist contents.)
1829 */
1830 struct killarg ka;
1831
1832 dsl_deadlist_close(&ds->ds_deadlist);
1833 dsl_deadlist_free(mos, ds->ds_phys->ds_deadlist_obj, tx);
1834 ds->ds_phys->ds_deadlist_obj = 0;
1835
1836 /*
1837 * Free everything that we point to (that's born after
1838 * the previous snapshot, if we are a clone)
1839 *
1840 * NB: this should be very quick, because we already
1841 * freed all the objects in open context.
1842 */
1843 ka.ds = ds;
1844 ka.tx = tx;
1845 err = traverse_dataset(ds, ds->ds_phys->ds_prev_snap_txg,
1846 TRAVERSE_POST, kill_blkptr, &ka);
1847 ASSERT3U(err, ==, 0);
1848 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) ||
1849 ds->ds_phys->ds_unique_bytes == 0);
1850
1851 if (ds->ds_prev != NULL) {
1852 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
1853 VERIFY3U(0, ==, zap_remove_int(mos,
1854 ds->ds_prev->ds_dir->dd_phys->dd_clones,
1855 ds->ds_object, tx));
1856 }
1857 dsl_dataset_rele(ds->ds_prev, ds);
1858 ds->ds_prev = ds_prev = NULL;
1859 }
1860 }
1861
1862 /*
1863 * This must be done after the dsl_traverse(), because it will
1864 * re-open the objset.
1865 */
1866 if (ds->ds_objset) {
1867 dmu_objset_evict(ds->ds_objset);
1868 ds->ds_objset = NULL;
1869 }
1870
1871 if (ds->ds_dir->dd_phys->dd_head_dataset_obj == ds->ds_object) {
1872 /* Erase the link in the dir */
1873 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx);
1874 ds->ds_dir->dd_phys->dd_head_dataset_obj = 0;
1875 ASSERT(ds->ds_phys->ds_snapnames_zapobj != 0);
1876 err = zap_destroy(mos, ds->ds_phys->ds_snapnames_zapobj, tx);
1877 ASSERT(err == 0);
1878 } else {
1879 /* remove from snapshot namespace */
1880 dsl_dataset_t *ds_head;
1881 ASSERT(ds->ds_phys->ds_snapnames_zapobj == 0);
1882 VERIFY(0 == dsl_dataset_hold_obj(dp,
1883 ds->ds_dir->dd_phys->dd_head_dataset_obj, FTAG, &ds_head));
1884 VERIFY(0 == dsl_dataset_get_snapname(ds));
1885 #ifdef ZFS_DEBUG
1886 {
1887 uint64_t val;
1888
1889 err = dsl_dataset_snap_lookup(ds_head,
1890 ds->ds_snapname, &val);
1891 ASSERT3U(err, ==, 0);
1892 ASSERT3U(val, ==, obj);
1893 }
1894 #endif
1895 err = dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx);
1896 ASSERT(err == 0);
1897 dsl_dataset_rele(ds_head, FTAG);
1898 }
1899
1900 if (ds_prev && ds->ds_prev != ds_prev)
1901 dsl_dataset_rele(ds_prev, FTAG);
1902
1903 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx);
1904 spa_history_log_internal(LOG_DS_DESTROY, dp->dp_spa, tx,
1905 "dataset = %llu", ds->ds_object);
1906
1907 if (ds->ds_phys->ds_next_clones_obj != 0) {
1908 uint64_t count;
1909 ASSERT(0 == zap_count(mos,
1910 ds->ds_phys->ds_next_clones_obj, &count) && count == 0);
1911 VERIFY(0 == dmu_object_free(mos,
1912 ds->ds_phys->ds_next_clones_obj, tx));
1913 }
1914 if (ds->ds_phys->ds_props_obj != 0)
1915 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_props_obj, tx));
1916 if (ds->ds_phys->ds_userrefs_obj != 0)
1917 VERIFY(0 == zap_destroy(mos, ds->ds_phys->ds_userrefs_obj, tx));
1918 dsl_dir_close(ds->ds_dir, ds);
1919 ds->ds_dir = NULL;
1920 dsl_dataset_drain_refs(ds, tag);
1921 VERIFY(0 == dmu_object_free(mos, obj, tx));
1922
1923 if (dsda->rm_origin) {
1924 /*
1925 * Remove the origin of the clone we just destroyed.
1926 */
1927 struct dsl_ds_destroyarg ndsda = {0};
1928
1929 ndsda.ds = dsda->rm_origin;
1930 dsl_dataset_destroy_sync(&ndsda, tag, tx);
1931 }
1932 }
1933
1934 static int
1935 dsl_dataset_snapshot_reserve_space(dsl_dataset_t *ds, dmu_tx_t *tx)
1936 {
1937 uint64_t asize;
1938
1939 if (!dmu_tx_is_syncing(tx))
1940 return (0);
1941
1942 /*
1943 * If there's an fs-only reservation, any blocks that might become
1944 * owned by the snapshot dataset must be accommodated by space
1945 * outside of the reservation.
1946 */
1947 ASSERT(ds->ds_reserved == 0 || DS_UNIQUE_IS_ACCURATE(ds));
1948 asize = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
1949 if (asize > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
1950 return (ENOSPC);
1951
1952 /*
1953 * Propogate any reserved space for this snapshot to other
1954 * snapshot checks in this sync group.
1955 */
1956 if (asize > 0)
1957 dsl_dir_willuse_space(ds->ds_dir, asize, tx);
1958
1959 return (0);
1960 }
1961
1962 int
1963 dsl_dataset_snapshot_check(void *arg1, void *arg2, dmu_tx_t *tx)
1964 {
1965 dsl_dataset_t *ds = arg1;
1966 const char *snapname = arg2;
1967 int err;
1968 uint64_t value;
1969
1970 /*
1971 * We don't allow multiple snapshots of the same txg. If there
1972 * is already one, try again.
1973 */
1974 if (ds->ds_phys->ds_prev_snap_txg >= tx->tx_txg)
1975 return (EAGAIN);
1976
1977 /*
1978 * Check for conflicting name snapshot name.
1979 */
1980 err = dsl_dataset_snap_lookup(ds, snapname, &value);
1981 if (err == 0)
1982 return (EEXIST);
1983 if (err != ENOENT)
1984 return (err);
1985
1986 /*
1987 * Check that the dataset's name is not too long. Name consists
1988 * of the dataset's length + 1 for the @-sign + snapshot name's length
1989 */
1990 if (dsl_dataset_namelen(ds) + 1 + strlen(snapname) >= MAXNAMELEN)
1991 return (ENAMETOOLONG);
1992
1993 err = dsl_dataset_snapshot_reserve_space(ds, tx);
1994 if (err)
1995 return (err);
1996
1997 ds->ds_trysnap_txg = tx->tx_txg;
1998 return (0);
1999 }
2000
2001 void
2002 dsl_dataset_snapshot_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2003 {
2004 dsl_dataset_t *ds = arg1;
2005 const char *snapname = arg2;
2006 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2007 dmu_buf_t *dbuf;
2008 dsl_dataset_phys_t *dsphys;
2009 uint64_t dsobj, crtxg;
2010 objset_t *mos = dp->dp_meta_objset;
2011 int err;
2012
2013 ASSERT(RW_WRITE_HELD(&dp->dp_config_rwlock));
2014
2015 /*
2016 * The origin's ds_creation_txg has to be < TXG_INITIAL
2017 */
2018 if (strcmp(snapname, ORIGIN_DIR_NAME) == 0)
2019 crtxg = 1;
2020 else
2021 crtxg = tx->tx_txg;
2022
2023 dsobj = dmu_object_alloc(mos, DMU_OT_DSL_DATASET, 0,
2024 DMU_OT_DSL_DATASET, sizeof (dsl_dataset_phys_t), tx);
2025 VERIFY(0 == dmu_bonus_hold(mos, dsobj, FTAG, &dbuf));
2026 dmu_buf_will_dirty(dbuf, tx);
2027 dsphys = dbuf->db_data;
2028 bzero(dsphys, sizeof (dsl_dataset_phys_t));
2029 dsphys->ds_dir_obj = ds->ds_dir->dd_object;
2030 dsphys->ds_fsid_guid = unique_create();
2031 (void) random_get_pseudo_bytes((void*)&dsphys->ds_guid,
2032 sizeof (dsphys->ds_guid));
2033 dsphys->ds_prev_snap_obj = ds->ds_phys->ds_prev_snap_obj;
2034 dsphys->ds_prev_snap_txg = ds->ds_phys->ds_prev_snap_txg;
2035 dsphys->ds_next_snap_obj = ds->ds_object;
2036 dsphys->ds_num_children = 1;
2037 dsphys->ds_creation_time = gethrestime_sec();
2038 dsphys->ds_creation_txg = crtxg;
2039 dsphys->ds_deadlist_obj = ds->ds_phys->ds_deadlist_obj;
2040 dsphys->ds_used_bytes = ds->ds_phys->ds_used_bytes;
2041 dsphys->ds_compressed_bytes = ds->ds_phys->ds_compressed_bytes;
2042 dsphys->ds_uncompressed_bytes = ds->ds_phys->ds_uncompressed_bytes;
2043 dsphys->ds_flags = ds->ds_phys->ds_flags;
2044 dsphys->ds_bp = ds->ds_phys->ds_bp;
2045 dmu_buf_rele(dbuf, FTAG);
2046
2047 ASSERT3U(ds->ds_prev != 0, ==, ds->ds_phys->ds_prev_snap_obj != 0);
2048 if (ds->ds_prev) {
2049 uint64_t next_clones_obj =
2050 ds->ds_prev->ds_phys->ds_next_clones_obj;
2051 ASSERT(ds->ds_prev->ds_phys->ds_next_snap_obj ==
2052 ds->ds_object ||
2053 ds->ds_prev->ds_phys->ds_num_children > 1);
2054 if (ds->ds_prev->ds_phys->ds_next_snap_obj == ds->ds_object) {
2055 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
2056 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, ==,
2057 ds->ds_prev->ds_phys->ds_creation_txg);
2058 ds->ds_prev->ds_phys->ds_next_snap_obj = dsobj;
2059 } else if (next_clones_obj != 0) {
2060 remove_from_next_clones(ds->ds_prev,
2061 dsphys->ds_next_snap_obj, tx);
2062 VERIFY3U(0, ==, zap_add_int(mos,
2063 next_clones_obj, dsobj, tx));
2064 }
2065 }
2066
2067 /*
2068 * If we have a reference-reservation on this dataset, we will
2069 * need to increase the amount of refreservation being charged
2070 * since our unique space is going to zero.
2071 */
2072 if (ds->ds_reserved) {
2073 int64_t delta;
2074 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
2075 delta = MIN(ds->ds_phys->ds_unique_bytes, ds->ds_reserved);
2076 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV,
2077 delta, 0, 0, tx);
2078 }
2079
2080 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2081 zfs_dbgmsg("taking snapshot %s@%s/%llu; newkey=%llu",
2082 ds->ds_dir->dd_myname, snapname, dsobj,
2083 ds->ds_phys->ds_prev_snap_txg);
2084 ds->ds_phys->ds_deadlist_obj = dsl_deadlist_clone(&ds->ds_deadlist,
2085 UINT64_MAX, ds->ds_phys->ds_prev_snap_obj, tx);
2086 dsl_deadlist_close(&ds->ds_deadlist);
2087 dsl_deadlist_open(&ds->ds_deadlist, mos, ds->ds_phys->ds_deadlist_obj);
2088 dsl_deadlist_add_key(&ds->ds_deadlist,
2089 ds->ds_phys->ds_prev_snap_txg, tx);
2090
2091 ASSERT3U(ds->ds_phys->ds_prev_snap_txg, <, tx->tx_txg);
2092 ds->ds_phys->ds_prev_snap_obj = dsobj;
2093 ds->ds_phys->ds_prev_snap_txg = crtxg;
2094 ds->ds_phys->ds_unique_bytes = 0;
2095 if (spa_version(dp->dp_spa) >= SPA_VERSION_UNIQUE_ACCURATE)
2096 ds->ds_phys->ds_flags |= DS_FLAG_UNIQUE_ACCURATE;
2097
2098 err = zap_add(mos, ds->ds_phys->ds_snapnames_zapobj,
2099 snapname, 8, 1, &dsobj, tx);
2100 ASSERT(err == 0);
2101
2102 if (ds->ds_prev)
2103 dsl_dataset_drop_ref(ds->ds_prev, ds);
2104 VERIFY(0 == dsl_dataset_get_ref(dp,
2105 ds->ds_phys->ds_prev_snap_obj, ds, &ds->ds_prev));
2106
2107 dsl_scan_ds_snapshotted(ds, tx);
2108
2109 dsl_dir_snap_cmtime_update(ds->ds_dir);
2110
2111 spa_history_log_internal(LOG_DS_SNAPSHOT, dp->dp_spa, tx,
2112 "dataset = %llu", dsobj);
2113 }
2114
2115 void
2116 dsl_dataset_sync(dsl_dataset_t *ds, zio_t *zio, dmu_tx_t *tx)
2117 {
2118 ASSERT(dmu_tx_is_syncing(tx));
2119 ASSERT(ds->ds_objset != NULL);
2120 ASSERT(ds->ds_phys->ds_next_snap_obj == 0);
2121
2122 /*
2123 * in case we had to change ds_fsid_guid when we opened it,
2124 * sync it out now.
2125 */
2126 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2127 ds->ds_phys->ds_fsid_guid = ds->ds_fsid_guid;
2128
2129 dsl_dir_dirty(ds->ds_dir, tx);
2130 dmu_objset_sync(ds->ds_objset, zio, tx);
2131 }
2132
2133 static void
2134 get_clones_stat(dsl_dataset_t *ds, nvlist_t *nv)
2135 {
2136 uint64_t count = 0;
2137 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
2138 zap_cursor_t zc;
2139 zap_attribute_t za;
2140 nvlist_t *propval;
2141 nvlist_t *val;
2142
2143 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER);
2144 VERIFY(nvlist_alloc(&propval, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2145 VERIFY(nvlist_alloc(&val, NV_UNIQUE_NAME, KM_SLEEP) == 0);
2146
2147 /*
2148 * There may me missing entries in ds_next_clones_obj
2149 * due to a bug in a previous version of the code.
2150 * Only trust it if it has the right number of entries.
2151 */
2152 if (ds->ds_phys->ds_next_clones_obj != 0) {
2153 ASSERT3U(0, ==, zap_count(mos, ds->ds_phys->ds_next_clones_obj,
2154 &count));
2155 }
2156 if (count != ds->ds_phys->ds_num_children - 1) {
2157 goto fail;
2158 }
2159 for (zap_cursor_init(&zc, mos, ds->ds_phys->ds_next_clones_obj);
2160 zap_cursor_retrieve(&zc, &za) == 0;
2161 zap_cursor_advance(&zc)) {
2162 dsl_dataset_t *clone;
2163 char buf[ZFS_MAXNAMELEN];
2164 if (dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
2165 za.za_first_integer, FTAG, &clone) != 0) {
2166 goto fail;
2167 }
2168 dsl_dir_name(clone->ds_dir, buf);
2169 VERIFY(nvlist_add_boolean(val, buf) == 0);
2170 dsl_dataset_rele(clone, FTAG);
2171 }
2172 zap_cursor_fini(&zc);
2173 VERIFY(nvlist_add_nvlist(propval, ZPROP_VALUE, val) == 0);
2174 VERIFY(nvlist_add_nvlist(nv, zfs_prop_to_name(ZFS_PROP_CLONES),
2175 propval) == 0);
2176 fail:
2177 nvlist_free(val);
2178 nvlist_free(propval);
2179 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock);
2180 }
2181
2182 void
2183 dsl_dataset_stats(dsl_dataset_t *ds, nvlist_t *nv)
2184 {
2185 uint64_t refd, avail, uobjs, aobjs, ratio;
2186
2187 dsl_dir_stats(ds->ds_dir, nv);
2188
2189 dsl_dataset_space(ds, &refd, &avail, &uobjs, &aobjs);
2190 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_AVAILABLE, avail);
2191 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFERENCED, refd);
2192
2193 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATION,
2194 ds->ds_phys->ds_creation_time);
2195 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_CREATETXG,
2196 ds->ds_phys->ds_creation_txg);
2197 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFQUOTA,
2198 ds->ds_quota);
2199 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRESERVATION,
2200 ds->ds_reserved);
2201 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_GUID,
2202 ds->ds_phys->ds_guid);
2203 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_UNIQUE,
2204 ds->ds_phys->ds_unique_bytes);
2205 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_OBJSETID,
2206 ds->ds_object);
2207 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USERREFS,
2208 ds->ds_userrefs);
2209 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_DEFER_DESTROY,
2210 DS_IS_DEFER_DESTROY(ds) ? 1 : 0);
2211
2212 if (ds->ds_phys->ds_prev_snap_obj != 0) {
2213 uint64_t written, comp, uncomp;
2214 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2215 dsl_dataset_t *prev;
2216
2217 rw_enter(&dp->dp_config_rwlock, RW_READER);
2218 int err = dsl_dataset_hold_obj(dp,
2219 ds->ds_phys->ds_prev_snap_obj, FTAG, &prev);
2220 rw_exit(&dp->dp_config_rwlock);
2221 if (err == 0) {
2222 err = dsl_dataset_space_written(prev, ds, &written,
2223 &comp, &uncomp);
2224 dsl_dataset_rele(prev, FTAG);
2225 if (err == 0) {
2226 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_WRITTEN,
2227 written);
2228 }
2229 }
2230 }
2231
2232 ratio = ds->ds_phys->ds_compressed_bytes == 0 ? 100 :
2233 (ds->ds_phys->ds_uncompressed_bytes * 100 /
2234 ds->ds_phys->ds_compressed_bytes);
2235 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_REFRATIO, ratio);
2236
2237 if (ds->ds_phys->ds_next_snap_obj) {
2238 /*
2239 * This is a snapshot; override the dd's space used with
2240 * our unique space and compression ratio.
2241 */
2242 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_USED,
2243 ds->ds_phys->ds_unique_bytes);
2244 dsl_prop_nvlist_add_uint64(nv, ZFS_PROP_COMPRESSRATIO, ratio);
2245
2246 get_clones_stat(ds, nv);
2247 }
2248 }
2249
2250 void
2251 dsl_dataset_fast_stat(dsl_dataset_t *ds, dmu_objset_stats_t *stat)
2252 {
2253 stat->dds_creation_txg = ds->ds_phys->ds_creation_txg;
2254 stat->dds_inconsistent = ds->ds_phys->ds_flags & DS_FLAG_INCONSISTENT;
2255 stat->dds_guid = ds->ds_phys->ds_guid;
2256 if (ds->ds_phys->ds_next_snap_obj) {
2257 stat->dds_is_snapshot = B_TRUE;
2258 stat->dds_num_clones = ds->ds_phys->ds_num_children - 1;
2259 } else {
2260 stat->dds_is_snapshot = B_FALSE;
2261 stat->dds_num_clones = 0;
2262 }
2263
2264 /* clone origin is really a dsl_dir thing... */
2265 rw_enter(&ds->ds_dir->dd_pool->dp_config_rwlock, RW_READER);
2266 if (dsl_dir_is_clone(ds->ds_dir)) {
2267 dsl_dataset_t *ods;
2268
2269 VERIFY(0 == dsl_dataset_get_ref(ds->ds_dir->dd_pool,
2270 ds->ds_dir->dd_phys->dd_origin_obj, FTAG, &ods));
2271 dsl_dataset_name(ods, stat->dds_origin);
2272 dsl_dataset_drop_ref(ods, FTAG);
2273 } else {
2274 stat->dds_origin[0] = '\0';
2275 }
2276 rw_exit(&ds->ds_dir->dd_pool->dp_config_rwlock);
2277 }
2278
2279 uint64_t
2280 dsl_dataset_fsid_guid(dsl_dataset_t *ds)
2281 {
2282 return (ds->ds_fsid_guid);
2283 }
2284
2285 void
2286 dsl_dataset_space(dsl_dataset_t *ds,
2287 uint64_t *refdbytesp, uint64_t *availbytesp,
2288 uint64_t *usedobjsp, uint64_t *availobjsp)
2289 {
2290 *refdbytesp = ds->ds_phys->ds_used_bytes;
2291 *availbytesp = dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE);
2292 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes)
2293 *availbytesp += ds->ds_reserved - ds->ds_phys->ds_unique_bytes;
2294 if (ds->ds_quota != 0) {
2295 /*
2296 * Adjust available bytes according to refquota
2297 */
2298 if (*refdbytesp < ds->ds_quota)
2299 *availbytesp = MIN(*availbytesp,
2300 ds->ds_quota - *refdbytesp);
2301 else
2302 *availbytesp = 0;
2303 }
2304 *usedobjsp = ds->ds_phys->ds_bp.blk_fill;
2305 *availobjsp = DN_MAX_OBJECT - *usedobjsp;
2306 }
2307
2308 boolean_t
2309 dsl_dataset_modified_since_lastsnap(dsl_dataset_t *ds)
2310 {
2311 dsl_pool_t *dp = ds->ds_dir->dd_pool;
2312
2313 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock) ||
2314 dsl_pool_sync_context(dp));
2315 if (ds->ds_prev == NULL)
2316 return (B_FALSE);
2317 if (ds->ds_phys->ds_bp.blk_birth >
2318 ds->ds_prev->ds_phys->ds_creation_txg) {
2319 objset_t *os, *os_prev;
2320 /*
2321 * It may be that only the ZIL differs, because it was
2322 * reset in the head. Don't count that as being
2323 * modified.
2324 */
2325 if (dmu_objset_from_ds(ds, &os) != 0)
2326 return (B_TRUE);
2327 if (dmu_objset_from_ds(ds->ds_prev, &os_prev) != 0)
2328 return (B_TRUE);
2329 return (bcmp(&os->os_phys->os_meta_dnode,
2330 &os_prev->os_phys->os_meta_dnode,
2331 sizeof (os->os_phys->os_meta_dnode)) != 0);
2332 }
2333 return (B_FALSE);
2334 }
2335
2336 /* ARGSUSED */
2337 static int
2338 dsl_dataset_snapshot_rename_check(void *arg1, void *arg2, dmu_tx_t *tx)
2339 {
2340 dsl_dataset_t *ds = arg1;
2341 char *newsnapname = arg2;
2342 dsl_dir_t *dd = ds->ds_dir;
2343 dsl_dataset_t *hds;
2344 uint64_t val;
2345 int err;
2346
2347 err = dsl_dataset_hold_obj(dd->dd_pool,
2348 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds);
2349 if (err)
2350 return (err);
2351
2352 /* new name better not be in use */
2353 err = dsl_dataset_snap_lookup(hds, newsnapname, &val);
2354 dsl_dataset_rele(hds, FTAG);
2355
2356 if (err == 0)
2357 err = EEXIST;
2358 else if (err == ENOENT)
2359 err = 0;
2360
2361 /* dataset name + 1 for the "@" + the new snapshot name must fit */
2362 if (dsl_dir_namelen(ds->ds_dir) + 1 + strlen(newsnapname) >= MAXNAMELEN)
2363 err = ENAMETOOLONG;
2364
2365 return (err);
2366 }
2367
2368 static void
2369 dsl_dataset_snapshot_rename_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2370 {
2371 dsl_dataset_t *ds = arg1;
2372 const char *newsnapname = arg2;
2373 dsl_dir_t *dd = ds->ds_dir;
2374 objset_t *mos = dd->dd_pool->dp_meta_objset;
2375 dsl_dataset_t *hds;
2376 int err;
2377
2378 ASSERT(ds->ds_phys->ds_next_snap_obj != 0);
2379
2380 VERIFY(0 == dsl_dataset_hold_obj(dd->dd_pool,
2381 dd->dd_phys->dd_head_dataset_obj, FTAG, &hds));
2382
2383 VERIFY(0 == dsl_dataset_get_snapname(ds));
2384 err = dsl_dataset_snap_remove(hds, ds->ds_snapname, tx);
2385 ASSERT3U(err, ==, 0);
2386 mutex_enter(&ds->ds_lock);
2387 (void) strcpy(ds->ds_snapname, newsnapname);
2388 mutex_exit(&ds->ds_lock);
2389 err = zap_add(mos, hds->ds_phys->ds_snapnames_zapobj,
2390 ds->ds_snapname, 8, 1, &ds->ds_object, tx);
2391 ASSERT3U(err, ==, 0);
2392
2393 spa_history_log_internal(LOG_DS_RENAME, dd->dd_pool->dp_spa, tx,
2394 "dataset = %llu", ds->ds_object);
2395 dsl_dataset_rele(hds, FTAG);
2396 }
2397
2398 struct renamesnaparg {
2399 dsl_sync_task_group_t *dstg;
2400 char failed[MAXPATHLEN];
2401 char *oldsnap;
2402 char *newsnap;
2403 };
2404
2405 static int
2406 dsl_snapshot_rename_one(const char *name, void *arg)
2407 {
2408 struct renamesnaparg *ra = arg;
2409 dsl_dataset_t *ds = NULL;
2410 char *snapname;
2411 int err;
2412
2413 snapname = kmem_asprintf("%s@%s", name, ra->oldsnap);
2414 (void) strlcpy(ra->failed, snapname, sizeof (ra->failed));
2415
2416 /*
2417 * For recursive snapshot renames the parent won't be changing
2418 * so we just pass name for both the to/from argument.
2419 */
2420 err = zfs_secpolicy_rename_perms(snapname, snapname, CRED());
2421 if (err != 0) {
2422 strfree(snapname);
2423 return (err == ENOENT ? 0 : err);
2424 }
2425
2426 #ifdef _KERNEL
2427 /*
2428 * For all filesystems undergoing rename, we'll need to unmount it.
2429 */
2430 (void) zfs_unmount_snap(snapname, NULL);
2431 #endif
2432 err = dsl_dataset_hold(snapname, ra->dstg, &ds);
2433 strfree(snapname);
2434 if (err != 0)
2435 return (err == ENOENT ? 0 : err);
2436
2437 dsl_sync_task_create(ra->dstg, dsl_dataset_snapshot_rename_check,
2438 dsl_dataset_snapshot_rename_sync, ds, ra->newsnap, 0);
2439
2440 return (0);
2441 }
2442
2443 static int
2444 dsl_recursive_rename(char *oldname, const char *newname)
2445 {
2446 int err;
2447 struct renamesnaparg *ra;
2448 dsl_sync_task_t *dst;
2449 spa_t *spa;
2450 char *cp, *fsname = spa_strdup(oldname);
2451 int len = strlen(oldname) + 1;
2452
2453 /* truncate the snapshot name to get the fsname */
2454 cp = strchr(fsname, '@');
2455 *cp = '\0';
2456
2457 err = spa_open(fsname, &spa, FTAG);
2458 if (err) {
2459 kmem_free(fsname, len);
2460 return (err);
2461 }
2462 ra = kmem_alloc(sizeof (struct renamesnaparg), KM_SLEEP);
2463 ra->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
2464
2465 ra->oldsnap = strchr(oldname, '@') + 1;
2466 ra->newsnap = strchr(newname, '@') + 1;
2467 *ra->failed = '\0';
2468
2469 err = dmu_objset_find(fsname, dsl_snapshot_rename_one, ra,
2470 DS_FIND_CHILDREN);
2471 kmem_free(fsname, len);
2472
2473 if (err == 0) {
2474 err = dsl_sync_task_group_wait(ra->dstg);
2475 }
2476
2477 for (dst = list_head(&ra->dstg->dstg_tasks); dst;
2478 dst = list_next(&ra->dstg->dstg_tasks, dst)) {
2479 dsl_dataset_t *ds = dst->dst_arg1;
2480 if (dst->dst_err) {
2481 dsl_dir_name(ds->ds_dir, ra->failed);
2482 (void) strlcat(ra->failed, "@", sizeof (ra->failed));
2483 (void) strlcat(ra->failed, ra->newsnap,
2484 sizeof (ra->failed));
2485 }
2486 dsl_dataset_rele(ds, ra->dstg);
2487 }
2488
2489 if (err)
2490 (void) strlcpy(oldname, ra->failed, sizeof (ra->failed));
2491
2492 dsl_sync_task_group_destroy(ra->dstg);
2493 kmem_free(ra, sizeof (struct renamesnaparg));
2494 spa_close(spa, FTAG);
2495 return (err);
2496 }
2497
2498 static int
2499 dsl_valid_rename(const char *oldname, void *arg)
2500 {
2501 int delta = *(int *)arg;
2502
2503 if (strlen(oldname) + delta >= MAXNAMELEN)
2504 return (ENAMETOOLONG);
2505
2506 return (0);
2507 }
2508
2509 #pragma weak dmu_objset_rename = dsl_dataset_rename
2510 int
2511 dsl_dataset_rename(char *oldname, const char *newname, boolean_t recursive)
2512 {
2513 dsl_dir_t *dd;
2514 dsl_dataset_t *ds;
2515 const char *tail;
2516 int err;
2517
2518 err = dsl_dir_open(oldname, FTAG, &dd, &tail);
2519 if (err)
2520 return (err);
2521
2522 if (tail == NULL) {
2523 int delta = strlen(newname) - strlen(oldname);
2524
2525 /* if we're growing, validate child name lengths */
2526 if (delta > 0)
2527 err = dmu_objset_find(oldname, dsl_valid_rename,
2528 &delta, DS_FIND_CHILDREN | DS_FIND_SNAPSHOTS);
2529
2530 if (err == 0)
2531 err = dsl_dir_rename(dd, newname);
2532 dsl_dir_close(dd, FTAG);
2533 return (err);
2534 }
2535
2536 if (tail[0] != '@') {
2537 /* the name ended in a nonexistent component */
2538 dsl_dir_close(dd, FTAG);
2539 return (ENOENT);
2540 }
2541
2542 dsl_dir_close(dd, FTAG);
2543
2544 /* new name must be snapshot in same filesystem */
2545 tail = strchr(newname, '@');
2546 if (tail == NULL)
2547 return (EINVAL);
2548 tail++;
2549 if (strncmp(oldname, newname, tail - newname) != 0)
2550 return (EXDEV);
2551
2552 if (recursive) {
2553 err = dsl_recursive_rename(oldname, newname);
2554 } else {
2555 err = dsl_dataset_hold(oldname, FTAG, &ds);
2556 if (err)
2557 return (err);
2558
2559 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
2560 dsl_dataset_snapshot_rename_check,
2561 dsl_dataset_snapshot_rename_sync, ds, (char *)tail, 1);
2562
2563 dsl_dataset_rele(ds, FTAG);
2564 }
2565
2566 return (err);
2567 }
2568
2569 struct promotenode {
2570 list_node_t link;
2571 dsl_dataset_t *ds;
2572 };
2573
2574 struct promotearg {
2575 list_t shared_snaps, origin_snaps, clone_snaps;
2576 dsl_dataset_t *origin_origin;
2577 uint64_t used, comp, uncomp, unique, cloneusedsnap, originusedsnap;
2578 char *err_ds;
2579 };
2580
2581 static int snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep);
2582 static boolean_t snaplist_unstable(list_t *l);
2583
2584 static int
2585 dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx)
2586 {
2587 dsl_dataset_t *hds = arg1;
2588 struct promotearg *pa = arg2;
2589 struct promotenode *snap = list_head(&pa->shared_snaps);
2590 dsl_dataset_t *origin_ds = snap->ds;
2591 int err;
2592 uint64_t unused;
2593
2594 /* Check that it is a real clone */
2595 if (!dsl_dir_is_clone(hds->ds_dir))
2596 return (EINVAL);
2597
2598 /* Since this is so expensive, don't do the preliminary check */
2599 if (!dmu_tx_is_syncing(tx))
2600 return (0);
2601
2602 if (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE)
2603 return (EXDEV);
2604
2605 /* compute origin's new unique space */
2606 snap = list_tail(&pa->clone_snaps);
2607 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2608 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2609 origin_ds->ds_phys->ds_prev_snap_txg, UINT64_MAX,
2610 &pa->unique, &unused, &unused);
2611
2612 /*
2613 * Walk the snapshots that we are moving
2614 *
2615 * Compute space to transfer. Consider the incremental changes
2616 * to used for each snapshot:
2617 * (my used) = (prev's used) + (blocks born) - (blocks killed)
2618 * So each snapshot gave birth to:
2619 * (blocks born) = (my used) - (prev's used) + (blocks killed)
2620 * So a sequence would look like:
2621 * (uN - u(N-1) + kN) + ... + (u1 - u0 + k1) + (u0 - 0 + k0)
2622 * Which simplifies to:
2623 * uN + kN + kN-1 + ... + k1 + k0
2624 * Note however, if we stop before we reach the ORIGIN we get:
2625 * uN + kN + kN-1 + ... + kM - uM-1
2626 */
2627 pa->used = origin_ds->ds_phys->ds_used_bytes;
2628 pa->comp = origin_ds->ds_phys->ds_compressed_bytes;
2629 pa->uncomp = origin_ds->ds_phys->ds_uncompressed_bytes;
2630 for (snap = list_head(&pa->shared_snaps); snap;
2631 snap = list_next(&pa->shared_snaps, snap)) {
2632 uint64_t val, dlused, dlcomp, dluncomp;
2633 dsl_dataset_t *ds = snap->ds;
2634
2635 /* Check that the snapshot name does not conflict */
2636 VERIFY(0 == dsl_dataset_get_snapname(ds));
2637 err = dsl_dataset_snap_lookup(hds, ds->ds_snapname, &val);
2638 if (err == 0) {
2639 err = EEXIST;
2640 goto out;
2641 }
2642 if (err != ENOENT)
2643 goto out;
2644
2645 /* The very first snapshot does not have a deadlist */
2646 if (ds->ds_phys->ds_prev_snap_obj == 0)
2647 continue;
2648
2649 dsl_deadlist_space(&ds->ds_deadlist,
2650 &dlused, &dlcomp, &dluncomp);
2651 pa->used += dlused;
2652 pa->comp += dlcomp;
2653 pa->uncomp += dluncomp;
2654 }
2655
2656 /*
2657 * If we are a clone of a clone then we never reached ORIGIN,
2658 * so we need to subtract out the clone origin's used space.
2659 */
2660 if (pa->origin_origin) {
2661 pa->used -= pa->origin_origin->ds_phys->ds_used_bytes;
2662 pa->comp -= pa->origin_origin->ds_phys->ds_compressed_bytes;
2663 pa->uncomp -= pa->origin_origin->ds_phys->ds_uncompressed_bytes;
2664 }
2665
2666 /* Check that there is enough space here */
2667 err = dsl_dir_transfer_possible(origin_ds->ds_dir, hds->ds_dir,
2668 pa->used);
2669 if (err)
2670 return (err);
2671
2672 /*
2673 * Compute the amounts of space that will be used by snapshots
2674 * after the promotion (for both origin and clone). For each,
2675 * it is the amount of space that will be on all of their
2676 * deadlists (that was not born before their new origin).
2677 */
2678 if (hds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2679 uint64_t space;
2680
2681 /*
2682 * Note, typically this will not be a clone of a clone,
2683 * so dd_origin_txg will be < TXG_INITIAL, so
2684 * these snaplist_space() -> dsl_deadlist_space_range()
2685 * calls will be fast because they do not have to
2686 * iterate over all bps.
2687 */
2688 snap = list_head(&pa->origin_snaps);
2689 err = snaplist_space(&pa->shared_snaps,
2690 snap->ds->ds_dir->dd_origin_txg, &pa->cloneusedsnap);
2691 if (err)
2692 return (err);
2693
2694 err = snaplist_space(&pa->clone_snaps,
2695 snap->ds->ds_dir->dd_origin_txg, &space);
2696 if (err)
2697 return (err);
2698 pa->cloneusedsnap += space;
2699 }
2700 if (origin_ds->ds_dir->dd_phys->dd_flags & DD_FLAG_USED_BREAKDOWN) {
2701 err = snaplist_space(&pa->origin_snaps,
2702 origin_ds->ds_phys->ds_creation_txg, &pa->originusedsnap);
2703 if (err)
2704 return (err);
2705 }
2706
2707 return (0);
2708 out:
2709 pa->err_ds = snap->ds->ds_snapname;
2710 return (err);
2711 }
2712
2713 static void
2714 dsl_dataset_promote_sync(void *arg1, void *arg2, dmu_tx_t *tx)
2715 {
2716 dsl_dataset_t *hds = arg1;
2717 struct promotearg *pa = arg2;
2718 struct promotenode *snap = list_head(&pa->shared_snaps);
2719 dsl_dataset_t *origin_ds = snap->ds;
2720 dsl_dataset_t *origin_head;
2721 dsl_dir_t *dd = hds->ds_dir;
2722 dsl_pool_t *dp = hds->ds_dir->dd_pool;
2723 dsl_dir_t *odd = NULL;
2724 uint64_t oldnext_obj;
2725 int64_t delta;
2726
2727 ASSERT(0 == (hds->ds_phys->ds_flags & DS_FLAG_NOPROMOTE));
2728
2729 snap = list_head(&pa->origin_snaps);
2730 origin_head = snap->ds;
2731
2732 /*
2733 * We need to explicitly open odd, since origin_ds's dd will be
2734 * changing.
2735 */
2736 VERIFY(0 == dsl_dir_open_obj(dp, origin_ds->ds_dir->dd_object,
2737 NULL, FTAG, &odd));
2738
2739 /* change origin's next snap */
2740 dmu_buf_will_dirty(origin_ds->ds_dbuf, tx);
2741 oldnext_obj = origin_ds->ds_phys->ds_next_snap_obj;
2742 snap = list_tail(&pa->clone_snaps);
2743 ASSERT3U(snap->ds->ds_phys->ds_prev_snap_obj, ==, origin_ds->ds_object);
2744 origin_ds->ds_phys->ds_next_snap_obj = snap->ds->ds_object;
2745
2746 /* change the origin's next clone */
2747 if (origin_ds->ds_phys->ds_next_clones_obj) {
2748 remove_from_next_clones(origin_ds, snap->ds->ds_object, tx);
2749 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2750 origin_ds->ds_phys->ds_next_clones_obj,
2751 oldnext_obj, tx));
2752 }
2753
2754 /* change origin */
2755 dmu_buf_will_dirty(dd->dd_dbuf, tx);
2756 ASSERT3U(dd->dd_phys->dd_origin_obj, ==, origin_ds->ds_object);
2757 dd->dd_phys->dd_origin_obj = odd->dd_phys->dd_origin_obj;
2758 dd->dd_origin_txg = origin_head->ds_dir->dd_origin_txg;
2759 dmu_buf_will_dirty(odd->dd_dbuf, tx);
2760 odd->dd_phys->dd_origin_obj = origin_ds->ds_object;
2761 origin_head->ds_dir->dd_origin_txg =
2762 origin_ds->ds_phys->ds_creation_txg;
2763
2764 /* change dd_clone entries */
2765 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2766 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
2767 odd->dd_phys->dd_clones, hds->ds_object, tx));
2768 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2769 pa->origin_origin->ds_dir->dd_phys->dd_clones,
2770 hds->ds_object, tx));
2771
2772 VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset,
2773 pa->origin_origin->ds_dir->dd_phys->dd_clones,
2774 origin_head->ds_object, tx));
2775 if (dd->dd_phys->dd_clones == 0) {
2776 dd->dd_phys->dd_clones = zap_create(dp->dp_meta_objset,
2777 DMU_OT_DSL_CLONES, DMU_OT_NONE, 0, tx);
2778 }
2779 VERIFY3U(0, ==, zap_add_int(dp->dp_meta_objset,
2780 dd->dd_phys->dd_clones, origin_head->ds_object, tx));
2781
2782 }
2783
2784 /* move snapshots to this dir */
2785 for (snap = list_head(&pa->shared_snaps); snap;
2786 snap = list_next(&pa->shared_snaps, snap)) {
2787 dsl_dataset_t *ds = snap->ds;
2788
2789 /* unregister props as dsl_dir is changing */
2790 if (ds->ds_objset) {
2791 dmu_objset_evict(ds->ds_objset);
2792 ds->ds_objset = NULL;
2793 }
2794 /* move snap name entry */
2795 VERIFY(0 == dsl_dataset_get_snapname(ds));
2796 VERIFY(0 == dsl_dataset_snap_remove(origin_head,
2797 ds->ds_snapname, tx));
2798 VERIFY(0 == zap_add(dp->dp_meta_objset,
2799 hds->ds_phys->ds_snapnames_zapobj, ds->ds_snapname,
2800 8, 1, &ds->ds_object, tx));
2801
2802 /* change containing dsl_dir */
2803 dmu_buf_will_dirty(ds->ds_dbuf, tx);
2804 ASSERT3U(ds->ds_phys->ds_dir_obj, ==, odd->dd_object);
2805 ds->ds_phys->ds_dir_obj = dd->dd_object;
2806 ASSERT3P(ds->ds_dir, ==, odd);
2807 dsl_dir_close(ds->ds_dir, ds);
2808 VERIFY(0 == dsl_dir_open_obj(dp, dd->dd_object,
2809 NULL, ds, &ds->ds_dir));
2810
2811 /* move any clone references */
2812 if (ds->ds_phys->ds_next_clones_obj &&
2813 spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
2814 zap_cursor_t zc;
2815 zap_attribute_t za;
2816
2817 for (zap_cursor_init(&zc, dp->dp_meta_objset,
2818 ds->ds_phys->ds_next_clones_obj);
2819 zap_cursor_retrieve(&zc, &za) == 0;
2820 zap_cursor_advance(&zc)) {
2821 dsl_dataset_t *cnds;
2822 uint64_t o;
2823
2824 if (za.za_first_integer == oldnext_obj) {
2825 /*
2826 * We've already moved the
2827 * origin's reference.
2828 */
2829 continue;
2830 }
2831
2832 VERIFY3U(0, ==, dsl_dataset_hold_obj(dp,
2833 za.za_first_integer, FTAG, &cnds));
2834 o = cnds->ds_dir->dd_phys->dd_head_dataset_obj;
2835
2836 VERIFY3U(zap_remove_int(dp->dp_meta_objset,
2837 odd->dd_phys->dd_clones, o, tx), ==, 0);
2838 VERIFY3U(zap_add_int(dp->dp_meta_objset,
2839 dd->dd_phys->dd_clones, o, tx), ==, 0);
2840 dsl_dataset_rele(cnds, FTAG);
2841 }
2842 zap_cursor_fini(&zc);
2843 }
2844
2845 ASSERT3U(dsl_prop_numcb(ds), ==, 0);
2846 }
2847
2848 /*
2849 * Change space accounting.
2850 * Note, pa->*usedsnap and dd_used_breakdown[SNAP] will either
2851 * both be valid, or both be 0 (resulting in delta == 0). This
2852 * is true for each of {clone,origin} independently.
2853 */
2854
2855 delta = pa->cloneusedsnap -
2856 dd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2857 ASSERT3S(delta, >=, 0);
2858 ASSERT3U(pa->used, >=, delta);
2859 dsl_dir_diduse_space(dd, DD_USED_SNAP, delta, 0, 0, tx);
2860 dsl_dir_diduse_space(dd, DD_USED_HEAD,
2861 pa->used - delta, pa->comp, pa->uncomp, tx);
2862
2863 delta = pa->originusedsnap -
2864 odd->dd_phys->dd_used_breakdown[DD_USED_SNAP];
2865 ASSERT3S(delta, <=, 0);
2866 ASSERT3U(pa->used, >=, -delta);
2867 dsl_dir_diduse_space(odd, DD_USED_SNAP, delta, 0, 0, tx);
2868 dsl_dir_diduse_space(odd, DD_USED_HEAD,
2869 -pa->used - delta, -pa->comp, -pa->uncomp, tx);
2870
2871 origin_ds->ds_phys->ds_unique_bytes = pa->unique;
2872
2873 /* log history record */
2874 spa_history_log_internal(LOG_DS_PROMOTE, dd->dd_pool->dp_spa, tx,
2875 "dataset = %llu", hds->ds_object);
2876
2877 dsl_dir_close(odd, FTAG);
2878 }
2879
2880 static char *snaplist_tag = "snaplist";
2881 /*
2882 * Make a list of dsl_dataset_t's for the snapshots between first_obj
2883 * (exclusive) and last_obj (inclusive). The list will be in reverse
2884 * order (last_obj will be the list_head()). If first_obj == 0, do all
2885 * snapshots back to this dataset's origin.
2886 */
2887 static int
2888 snaplist_make(dsl_pool_t *dp, boolean_t own,
2889 uint64_t first_obj, uint64_t last_obj, list_t *l)
2890 {
2891 uint64_t obj = last_obj;
2892
2893 ASSERT(RW_LOCK_HELD(&dp->dp_config_rwlock));
2894
2895 list_create(l, sizeof (struct promotenode),
2896 offsetof(struct promotenode, link));
2897
2898 while (obj != first_obj) {
2899 dsl_dataset_t *ds;
2900 struct promotenode *snap;
2901 int err;
2902
2903 if (own) {
2904 err = dsl_dataset_own_obj(dp, obj,
2905 0, snaplist_tag, &ds);
2906 if (err == 0)
2907 dsl_dataset_make_exclusive(ds, snaplist_tag);
2908 } else {
2909 err = dsl_dataset_hold_obj(dp, obj, snaplist_tag, &ds);
2910 }
2911 if (err == ENOENT) {
2912 /* lost race with snapshot destroy */
2913 struct promotenode *last = list_tail(l);
2914 ASSERT(obj != last->ds->ds_phys->ds_prev_snap_obj);
2915 obj = last->ds->ds_phys->ds_prev_snap_obj;
2916 continue;
2917 } else if (err) {
2918 return (err);
2919 }
2920
2921 if (first_obj == 0)
2922 first_obj = ds->ds_dir->dd_phys->dd_origin_obj;
2923
2924 snap = kmem_alloc(sizeof (struct promotenode), KM_SLEEP);
2925 snap->ds = ds;
2926 list_insert_tail(l, snap);
2927 obj = ds->ds_phys->ds_prev_snap_obj;
2928 }
2929
2930 return (0);
2931 }
2932
2933 static int
2934 snaplist_space(list_t *l, uint64_t mintxg, uint64_t *spacep)
2935 {
2936 struct promotenode *snap;
2937
2938 *spacep = 0;
2939 for (snap = list_head(l); snap; snap = list_next(l, snap)) {
2940 uint64_t used, comp, uncomp;
2941 dsl_deadlist_space_range(&snap->ds->ds_deadlist,
2942 mintxg, UINT64_MAX, &used, &comp, &uncomp);
2943 *spacep += used;
2944 }
2945 return (0);
2946 }
2947
2948 static void
2949 snaplist_destroy(list_t *l, boolean_t own)
2950 {
2951 struct promotenode *snap;
2952
2953 if (!l || !list_link_active(&l->list_head))
2954 return;
2955
2956 while ((snap = list_tail(l)) != NULL) {
2957 list_remove(l, snap);
2958 if (own)
2959 dsl_dataset_disown(snap->ds, snaplist_tag);
2960 else
2961 dsl_dataset_rele(snap->ds, snaplist_tag);
2962 kmem_free(snap, sizeof (struct promotenode));
2963 }
2964 list_destroy(l);
2965 }
2966
2967 /*
2968 * Promote a clone. Nomenclature note:
2969 * "clone" or "cds": the original clone which is being promoted
2970 * "origin" or "ods": the snapshot which is originally clone's origin
2971 * "origin head" or "ohds": the dataset which is the head
2972 * (filesystem/volume) for the origin
2973 * "origin origin": the origin of the origin's filesystem (typically
2974 * NULL, indicating that the clone is not a clone of a clone).
2975 */
2976 int
2977 dsl_dataset_promote(const char *name, char *conflsnap)
2978 {
2979 dsl_dataset_t *ds;
2980 dsl_dir_t *dd;
2981 dsl_pool_t *dp;
2982 dmu_object_info_t doi;
2983 struct promotearg pa = { 0 };
2984 struct promotenode *snap;
2985 int err;
2986
2987 err = dsl_dataset_hold(name, FTAG, &ds);
2988 if (err)
2989 return (err);
2990 dd = ds->ds_dir;
2991 dp = dd->dd_pool;
2992
2993 err = dmu_object_info(dp->dp_meta_objset,
2994 ds->ds_phys->ds_snapnames_zapobj, &doi);
2995 if (err) {
2996 dsl_dataset_rele(ds, FTAG);
2997 return (err);
2998 }
2999
3000 if (dsl_dataset_is_snapshot(ds) || dd->dd_phys->dd_origin_obj == 0) {
3001 dsl_dataset_rele(ds, FTAG);
3002 return (EINVAL);
3003 }
3004
3005 /*
3006 * We are going to inherit all the snapshots taken before our
3007 * origin (i.e., our new origin will be our parent's origin).
3008 * Take ownership of them so that we can rename them into our
3009 * namespace.
3010 */
3011 rw_enter(&dp->dp_config_rwlock, RW_READER);
3012
3013 err = snaplist_make(dp, B_TRUE, 0, dd->dd_phys->dd_origin_obj,
3014 &pa.shared_snaps);
3015 if (err != 0)
3016 goto out;
3017
3018 err = snaplist_make(dp, B_FALSE, 0, ds->ds_object, &pa.clone_snaps);
3019 if (err != 0)
3020 goto out;
3021
3022 snap = list_head(&pa.shared_snaps);
3023 ASSERT3U(snap->ds->ds_object, ==, dd->dd_phys->dd_origin_obj);
3024 err = snaplist_make(dp, B_FALSE, dd->dd_phys->dd_origin_obj,
3025 snap->ds->ds_dir->dd_phys->dd_head_dataset_obj, &pa.origin_snaps);
3026 if (err != 0)
3027 goto out;
3028
3029 if (snap->ds->ds_dir->dd_phys->dd_origin_obj != 0) {
3030 err = dsl_dataset_hold_obj(dp,
3031 snap->ds->ds_dir->dd_phys->dd_origin_obj,
3032 FTAG, &pa.origin_origin);
3033 if (err != 0)
3034 goto out;
3035 }
3036
3037 out:
3038 rw_exit(&dp->dp_config_rwlock);
3039
3040 /*
3041 * Add in 128x the snapnames zapobj size, since we will be moving
3042 * a bunch of snapnames to the promoted ds, and dirtying their
3043 * bonus buffers.
3044 */
3045 if (err == 0) {
3046 err = dsl_sync_task_do(dp, dsl_dataset_promote_check,
3047 dsl_dataset_promote_sync, ds, &pa,
3048 2 + 2 * doi.doi_physical_blocks_512);
3049 if (err && pa.err_ds && conflsnap)
3050 (void) strncpy(conflsnap, pa.err_ds, MAXNAMELEN);
3051 }
3052
3053 snaplist_destroy(&pa.shared_snaps, B_TRUE);
3054 snaplist_destroy(&pa.clone_snaps, B_FALSE);
3055 snaplist_destroy(&pa.origin_snaps, B_FALSE);
3056 if (pa.origin_origin)
3057 dsl_dataset_rele(pa.origin_origin, FTAG);
3058 dsl_dataset_rele(ds, FTAG);
3059 return (err);
3060 }
3061
3062 struct cloneswaparg {
3063 dsl_dataset_t *cds; /* clone dataset */
3064 dsl_dataset_t *ohds; /* origin's head dataset */
3065 boolean_t force;
3066 int64_t unused_refres_delta; /* change in unconsumed refreservation */
3067 };
3068
3069 /* ARGSUSED */
3070 static int
3071 dsl_dataset_clone_swap_check(void *arg1, void *arg2, dmu_tx_t *tx)
3072 {
3073 struct cloneswaparg *csa = arg1;
3074
3075 /* they should both be heads */
3076 if (dsl_dataset_is_snapshot(csa->cds) ||
3077 dsl_dataset_is_snapshot(csa->ohds))
3078 return (EINVAL);
3079
3080 /* the branch point should be just before them */
3081 if (csa->cds->ds_prev != csa->ohds->ds_prev)
3082 return (EINVAL);
3083
3084 /* cds should be the clone (unless they are unrelated) */
3085 if (csa->cds->ds_prev != NULL &&
3086 csa->cds->ds_prev != csa->cds->ds_dir->dd_pool->dp_origin_snap &&
3087 csa->ohds->ds_object !=
3088 csa->cds->ds_prev->ds_phys->ds_next_snap_obj)
3089 return (EINVAL);
3090
3091 /* the clone should be a child of the origin */
3092 if (csa->cds->ds_dir->dd_parent != csa->ohds->ds_dir)
3093 return (EINVAL);
3094
3095 /* ohds shouldn't be modified unless 'force' */
3096 if (!csa->force && dsl_dataset_modified_since_lastsnap(csa->ohds))
3097 return (ETXTBSY);
3098
3099 /* adjust amount of any unconsumed refreservation */
3100 csa->unused_refres_delta =
3101 (int64_t)MIN(csa->ohds->ds_reserved,
3102 csa->ohds->ds_phys->ds_unique_bytes) -
3103 (int64_t)MIN(csa->ohds->ds_reserved,
3104 csa->cds->ds_phys->ds_unique_bytes);
3105
3106 if (csa->unused_refres_delta > 0 &&
3107 csa->unused_refres_delta >
3108 dsl_dir_space_available(csa->ohds->ds_dir, NULL, 0, TRUE))
3109 return (ENOSPC);
3110
3111 if (csa->ohds->ds_quota != 0 &&
3112 csa->cds->ds_phys->ds_unique_bytes > csa->ohds->ds_quota)
3113 return (EDQUOT);
3114
3115 return (0);
3116 }
3117
3118 /* ARGSUSED */
3119 static void
3120 dsl_dataset_clone_swap_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3121 {
3122 struct cloneswaparg *csa = arg1;
3123 dsl_pool_t *dp = csa->cds->ds_dir->dd_pool;
3124
3125 ASSERT(csa->cds->ds_reserved == 0);
3126 ASSERT(csa->ohds->ds_quota == 0 ||
3127 csa->cds->ds_phys->ds_unique_bytes <= csa->ohds->ds_quota);
3128
3129 dmu_buf_will_dirty(csa->cds->ds_dbuf, tx);
3130 dmu_buf_will_dirty(csa->ohds->ds_dbuf, tx);
3131
3132 if (csa->cds->ds_objset != NULL) {
3133 dmu_objset_evict(csa->cds->ds_objset);
3134 csa->cds->ds_objset = NULL;
3135 }
3136
3137 if (csa->ohds->ds_objset != NULL) {
3138 dmu_objset_evict(csa->ohds->ds_objset);
3139 csa->ohds->ds_objset = NULL;
3140 }
3141
3142 /*
3143 * Reset origin's unique bytes, if it exists.
3144 */
3145 if (csa->cds->ds_prev) {
3146 dsl_dataset_t *origin = csa->cds->ds_prev;
3147 uint64_t comp, uncomp;
3148
3149 dmu_buf_will_dirty(origin->ds_dbuf, tx);
3150 dsl_deadlist_space_range(&csa->cds->ds_deadlist,
3151 origin->ds_phys->ds_prev_snap_txg, UINT64_MAX,
3152 &origin->ds_phys->ds_unique_bytes, &comp, &uncomp);
3153 }
3154
3155 /* swap blkptrs */
3156 {
3157 blkptr_t tmp;
3158 tmp = csa->ohds->ds_phys->ds_bp;
3159 csa->ohds->ds_phys->ds_bp = csa->cds->ds_phys->ds_bp;
3160 csa->cds->ds_phys->ds_bp = tmp;
3161 }
3162
3163 /* set dd_*_bytes */
3164 {
3165 int64_t dused, dcomp, duncomp;
3166 uint64_t cdl_used, cdl_comp, cdl_uncomp;
3167 uint64_t odl_used, odl_comp, odl_uncomp;
3168
3169 ASSERT3U(csa->cds->ds_dir->dd_phys->
3170 dd_used_breakdown[DD_USED_SNAP], ==, 0);
3171
3172 dsl_deadlist_space(&csa->cds->ds_deadlist,
3173 &cdl_used, &cdl_comp, &cdl_uncomp);
3174 dsl_deadlist_space(&csa->ohds->ds_deadlist,
3175 &odl_used, &odl_comp, &odl_uncomp);
3176
3177 dused = csa->cds->ds_phys->ds_used_bytes + cdl_used -
3178 (csa->ohds->ds_phys->ds_used_bytes + odl_used);
3179 dcomp = csa->cds->ds_phys->ds_compressed_bytes + cdl_comp -
3180 (csa->ohds->ds_phys->ds_compressed_bytes + odl_comp);
3181 duncomp = csa->cds->ds_phys->ds_uncompressed_bytes +
3182 cdl_uncomp -
3183 (csa->ohds->ds_phys->ds_uncompressed_bytes + odl_uncomp);
3184
3185 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_HEAD,
3186 dused, dcomp, duncomp, tx);
3187 dsl_dir_diduse_space(csa->cds->ds_dir, DD_USED_HEAD,
3188 -dused, -dcomp, -duncomp, tx);
3189
3190 /*
3191 * The difference in the space used by snapshots is the
3192 * difference in snapshot space due to the head's
3193 * deadlist (since that's the only thing that's
3194 * changing that affects the snapused).
3195 */
3196 dsl_deadlist_space_range(&csa->cds->ds_deadlist,
3197 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX,
3198 &cdl_used, &cdl_comp, &cdl_uncomp);
3199 dsl_deadlist_space_range(&csa->ohds->ds_deadlist,
3200 csa->ohds->ds_dir->dd_origin_txg, UINT64_MAX,
3201 &odl_used, &odl_comp, &odl_uncomp);
3202 dsl_dir_transfer_space(csa->ohds->ds_dir, cdl_used - odl_used,
3203 DD_USED_HEAD, DD_USED_SNAP, tx);
3204 }
3205
3206 /* swap ds_*_bytes */
3207 SWITCH64(csa->ohds->ds_phys->ds_used_bytes,
3208 csa->cds->ds_phys->ds_used_bytes);
3209 SWITCH64(csa->ohds->ds_phys->ds_compressed_bytes,
3210 csa->cds->ds_phys->ds_compressed_bytes);
3211 SWITCH64(csa->ohds->ds_phys->ds_uncompressed_bytes,
3212 csa->cds->ds_phys->ds_uncompressed_bytes);
3213 SWITCH64(csa->ohds->ds_phys->ds_unique_bytes,
3214 csa->cds->ds_phys->ds_unique_bytes);
3215
3216 /* apply any parent delta for change in unconsumed refreservation */
3217 dsl_dir_diduse_space(csa->ohds->ds_dir, DD_USED_REFRSRV,
3218 csa->unused_refres_delta, 0, 0, tx);
3219
3220 /*
3221 * Swap deadlists.
3222 */
3223 dsl_deadlist_close(&csa->cds->ds_deadlist);
3224 dsl_deadlist_close(&csa->ohds->ds_deadlist);
3225 SWITCH64(csa->ohds->ds_phys->ds_deadlist_obj,
3226 csa->cds->ds_phys->ds_deadlist_obj);
3227 dsl_deadlist_open(&csa->cds->ds_deadlist, dp->dp_meta_objset,
3228 csa->cds->ds_phys->ds_deadlist_obj);
3229 dsl_deadlist_open(&csa->ohds->ds_deadlist, dp->dp_meta_objset,
3230 csa->ohds->ds_phys->ds_deadlist_obj);
3231
3232 dsl_scan_ds_clone_swapped(csa->ohds, csa->cds, tx);
3233 }
3234
3235 /*
3236 * Swap 'clone' with its origin head datasets. Used at the end of "zfs
3237 * recv" into an existing fs to swizzle the file system to the new
3238 * version, and by "zfs rollback". Can also be used to swap two
3239 * independent head datasets if neither has any snapshots.
3240 */
3241 int
3242 dsl_dataset_clone_swap(dsl_dataset_t *clone, dsl_dataset_t *origin_head,
3243 boolean_t force)
3244 {
3245 struct cloneswaparg csa;
3246 int error;
3247
3248 ASSERT(clone->ds_owner);
3249 ASSERT(origin_head->ds_owner);
3250 retry:
3251 /*
3252 * Need exclusive access for the swap. If we're swapping these
3253 * datasets back after an error, we already hold the locks.
3254 */
3255 if (!RW_WRITE_HELD(&clone->ds_rwlock))
3256 rw_enter(&clone->ds_rwlock, RW_WRITER);
3257 if (!RW_WRITE_HELD(&origin_head->ds_rwlock) &&
3258 !rw_tryenter(&origin_head->ds_rwlock, RW_WRITER)) {
3259 rw_exit(&clone->ds_rwlock);
3260 rw_enter(&origin_head->ds_rwlock, RW_WRITER);
3261 if (!rw_tryenter(&clone->ds_rwlock, RW_WRITER)) {
3262 rw_exit(&origin_head->ds_rwlock);
3263 goto retry;
3264 }
3265 }
3266 csa.cds = clone;
3267 csa.ohds = origin_head;
3268 csa.force = force;
3269 error = dsl_sync_task_do(clone->ds_dir->dd_pool,
3270 dsl_dataset_clone_swap_check,
3271 dsl_dataset_clone_swap_sync, &csa, NULL, 9);
3272 return (error);
3273 }
3274
3275 /*
3276 * Given a pool name and a dataset object number in that pool,
3277 * return the name of that dataset.
3278 */
3279 int
3280 dsl_dsobj_to_dsname(char *pname, uint64_t obj, char *buf)
3281 {
3282 spa_t *spa;
3283 dsl_pool_t *dp;
3284 dsl_dataset_t *ds;
3285 int error;
3286
3287 if ((error = spa_open(pname, &spa, FTAG)) != 0)
3288 return (error);
3289 dp = spa_get_dsl(spa);
3290 rw_enter(&dp->dp_config_rwlock, RW_READER);
3291 if ((error = dsl_dataset_hold_obj(dp, obj, FTAG, &ds)) == 0) {
3292 dsl_dataset_name(ds, buf);
3293 dsl_dataset_rele(ds, FTAG);
3294 }
3295 rw_exit(&dp->dp_config_rwlock);
3296 spa_close(spa, FTAG);
3297
3298 return (error);
3299 }
3300
3301 int
3302 dsl_dataset_check_quota(dsl_dataset_t *ds, boolean_t check_quota,
3303 uint64_t asize, uint64_t inflight, uint64_t *used, uint64_t *ref_rsrv)
3304 {
3305 int error = 0;
3306
3307 ASSERT3S(asize, >, 0);
3308
3309 /*
3310 * *ref_rsrv is the portion of asize that will come from any
3311 * unconsumed refreservation space.
3312 */
3313 *ref_rsrv = 0;
3314
3315 mutex_enter(&ds->ds_lock);
3316 /*
3317 * Make a space adjustment for reserved bytes.
3318 */
3319 if (ds->ds_reserved > ds->ds_phys->ds_unique_bytes) {
3320 ASSERT3U(*used, >=,
3321 ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
3322 *used -= (ds->ds_reserved - ds->ds_phys->ds_unique_bytes);
3323 *ref_rsrv =
3324 asize - MIN(asize, parent_delta(ds, asize + inflight));
3325 }
3326
3327 if (!check_quota || ds->ds_quota == 0) {
3328 mutex_exit(&ds->ds_lock);
3329 return (0);
3330 }
3331 /*
3332 * If they are requesting more space, and our current estimate
3333 * is over quota, they get to try again unless the actual
3334 * on-disk is over quota and there are no pending changes (which
3335 * may free up space for us).
3336 */
3337 if (ds->ds_phys->ds_used_bytes + inflight >= ds->ds_quota) {
3338 if (inflight > 0 || ds->ds_phys->ds_used_bytes < ds->ds_quota)
3339 error = ERESTART;
3340 else
3341 error = EDQUOT;
3342 }
3343 mutex_exit(&ds->ds_lock);
3344
3345 return (error);
3346 }
3347
3348 /* ARGSUSED */
3349 static int
3350 dsl_dataset_set_quota_check(void *arg1, void *arg2, dmu_tx_t *tx)
3351 {
3352 dsl_dataset_t *ds = arg1;
3353 dsl_prop_setarg_t *psa = arg2;
3354 int err;
3355
3356 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_REFQUOTA)
3357 return (ENOTSUP);
3358
3359 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0)
3360 return (err);
3361
3362 if (psa->psa_effective_value == 0)
3363 return (0);
3364
3365 if (psa->psa_effective_value < ds->ds_phys->ds_used_bytes ||
3366 psa->psa_effective_value < ds->ds_reserved)
3367 return (ENOSPC);
3368
3369 return (0);
3370 }
3371
3372 extern void dsl_prop_set_sync(void *, void *, dmu_tx_t *);
3373
3374 void
3375 dsl_dataset_set_quota_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3376 {
3377 dsl_dataset_t *ds = arg1;
3378 dsl_prop_setarg_t *psa = arg2;
3379 uint64_t effective_value = psa->psa_effective_value;
3380
3381 dsl_prop_set_sync(ds, psa, tx);
3382 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa);
3383
3384 if (ds->ds_quota != effective_value) {
3385 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3386 ds->ds_quota = effective_value;
3387
3388 spa_history_log_internal(LOG_DS_REFQUOTA,
3389 ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu ",
3390 (longlong_t)ds->ds_quota, ds->ds_object);
3391 }
3392 }
3393
3394 int
3395 dsl_dataset_set_quota(const char *dsname, zprop_source_t source, uint64_t quota)
3396 {
3397 dsl_dataset_t *ds;
3398 dsl_prop_setarg_t psa;
3399 int err;
3400
3401 dsl_prop_setarg_init_uint64(&psa, "refquota", source, &quota);
3402
3403 err = dsl_dataset_hold(dsname, FTAG, &ds);
3404 if (err)
3405 return (err);
3406
3407 /*
3408 * If someone removes a file, then tries to set the quota, we
3409 * want to make sure the file freeing takes effect.
3410 */
3411 txg_wait_open(ds->ds_dir->dd_pool, 0);
3412
3413 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
3414 dsl_dataset_set_quota_check, dsl_dataset_set_quota_sync,
3415 ds, &psa, 0);
3416
3417 dsl_dataset_rele(ds, FTAG);
3418 return (err);
3419 }
3420
3421 static int
3422 dsl_dataset_set_reservation_check(void *arg1, void *arg2, dmu_tx_t *tx)
3423 {
3424 dsl_dataset_t *ds = arg1;
3425 dsl_prop_setarg_t *psa = arg2;
3426 uint64_t effective_value;
3427 uint64_t unique;
3428 int err;
3429
3430 if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
3431 SPA_VERSION_REFRESERVATION)
3432 return (ENOTSUP);
3433
3434 if (dsl_dataset_is_snapshot(ds))
3435 return (EINVAL);
3436
3437 if ((err = dsl_prop_predict_sync(ds->ds_dir, psa)) != 0)
3438 return (err);
3439
3440 effective_value = psa->psa_effective_value;
3441
3442 /*
3443 * If we are doing the preliminary check in open context, the
3444 * space estimates may be inaccurate.
3445 */
3446 if (!dmu_tx_is_syncing(tx))
3447 return (0);
3448
3449 mutex_enter(&ds->ds_lock);
3450 if (!DS_UNIQUE_IS_ACCURATE(ds))
3451 dsl_dataset_recalc_head_uniq(ds);
3452 unique = ds->ds_phys->ds_unique_bytes;
3453 mutex_exit(&ds->ds_lock);
3454
3455 if (MAX(unique, effective_value) > MAX(unique, ds->ds_reserved)) {
3456 uint64_t delta = MAX(unique, effective_value) -
3457 MAX(unique, ds->ds_reserved);
3458
3459 if (delta > dsl_dir_space_available(ds->ds_dir, NULL, 0, TRUE))
3460 return (ENOSPC);
3461 if (ds->ds_quota > 0 &&
3462 effective_value > ds->ds_quota)
3463 return (ENOSPC);
3464 }
3465
3466 return (0);
3467 }
3468
3469 static void
3470 dsl_dataset_set_reservation_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3471 {
3472 dsl_dataset_t *ds = arg1;
3473 dsl_prop_setarg_t *psa = arg2;
3474 uint64_t effective_value = psa->psa_effective_value;
3475 uint64_t unique;
3476 int64_t delta;
3477
3478 dsl_prop_set_sync(ds, psa, tx);
3479 DSL_PROP_CHECK_PREDICTION(ds->ds_dir, psa);
3480
3481 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3482
3483 mutex_enter(&ds->ds_dir->dd_lock);
3484 mutex_enter(&ds->ds_lock);
3485 ASSERT(DS_UNIQUE_IS_ACCURATE(ds));
3486 unique = ds->ds_phys->ds_unique_bytes;
3487 delta = MAX(0, (int64_t)(effective_value - unique)) -
3488 MAX(0, (int64_t)(ds->ds_reserved - unique));
3489 ds->ds_reserved = effective_value;
3490 mutex_exit(&ds->ds_lock);
3491
3492 dsl_dir_diduse_space(ds->ds_dir, DD_USED_REFRSRV, delta, 0, 0, tx);
3493 mutex_exit(&ds->ds_dir->dd_lock);
3494
3495 spa_history_log_internal(LOG_DS_REFRESERV,
3496 ds->ds_dir->dd_pool->dp_spa, tx, "%lld dataset = %llu",
3497 (longlong_t)effective_value, ds->ds_object);
3498 }
3499
3500 int
3501 dsl_dataset_set_reservation(const char *dsname, zprop_source_t source,
3502 uint64_t reservation)
3503 {
3504 dsl_dataset_t *ds;
3505 dsl_prop_setarg_t psa;
3506 int err;
3507
3508 dsl_prop_setarg_init_uint64(&psa, "refreservation", source,
3509 &reservation);
3510
3511 err = dsl_dataset_hold(dsname, FTAG, &ds);
3512 if (err)
3513 return (err);
3514
3515 err = dsl_sync_task_do(ds->ds_dir->dd_pool,
3516 dsl_dataset_set_reservation_check,
3517 dsl_dataset_set_reservation_sync, ds, &psa, 0);
3518
3519 dsl_dataset_rele(ds, FTAG);
3520 return (err);
3521 }
3522
3523 typedef struct zfs_hold_cleanup_arg {
3524 dsl_pool_t *dp;
3525 uint64_t dsobj;
3526 char htag[MAXNAMELEN];
3527 } zfs_hold_cleanup_arg_t;
3528
3529 static void
3530 dsl_dataset_user_release_onexit(void *arg)
3531 {
3532 zfs_hold_cleanup_arg_t *ca = arg;
3533
3534 (void) dsl_dataset_user_release_tmp(ca->dp, ca->dsobj, ca->htag,
3535 B_TRUE);
3536 kmem_free(ca, sizeof (zfs_hold_cleanup_arg_t));
3537 }
3538
3539 void
3540 dsl_register_onexit_hold_cleanup(dsl_dataset_t *ds, const char *htag,
3541 minor_t minor)
3542 {
3543 zfs_hold_cleanup_arg_t *ca;
3544
3545 ca = kmem_alloc(sizeof (zfs_hold_cleanup_arg_t), KM_SLEEP);
3546 ca->dp = ds->ds_dir->dd_pool;
3547 ca->dsobj = ds->ds_object;
3548 (void) strlcpy(ca->htag, htag, sizeof (ca->htag));
3549 VERIFY3U(0, ==, zfs_onexit_add_cb(minor,
3550 dsl_dataset_user_release_onexit, ca, NULL));
3551 }
3552
3553 /*
3554 * If you add new checks here, you may need to add
3555 * additional checks to the "temporary" case in
3556 * snapshot_check() in dmu_objset.c.
3557 */
3558 static int
3559 dsl_dataset_user_hold_check(void *arg1, void *arg2, dmu_tx_t *tx)
3560 {
3561 dsl_dataset_t *ds = arg1;
3562 struct dsl_ds_holdarg *ha = arg2;
3563 char *htag = ha->htag;
3564 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3565 int error = 0;
3566
3567 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS)
3568 return (ENOTSUP);
3569
3570 if (!dsl_dataset_is_snapshot(ds))
3571 return (EINVAL);
3572
3573 /* tags must be unique */
3574 mutex_enter(&ds->ds_lock);
3575 if (ds->ds_phys->ds_userrefs_obj) {
3576 error = zap_lookup(mos, ds->ds_phys->ds_userrefs_obj, htag,
3577 8, 1, tx);
3578 if (error == 0)
3579 error = EEXIST;
3580 else if (error == ENOENT)
3581 error = 0;
3582 }
3583 mutex_exit(&ds->ds_lock);
3584
3585 if (error == 0 && ha->temphold &&
3586 strlen(htag) + MAX_TAG_PREFIX_LEN >= MAXNAMELEN)
3587 error = E2BIG;
3588
3589 return (error);
3590 }
3591
3592 void
3593 dsl_dataset_user_hold_sync(void *arg1, void *arg2, dmu_tx_t *tx)
3594 {
3595 dsl_dataset_t *ds = arg1;
3596 struct dsl_ds_holdarg *ha = arg2;
3597 char *htag = ha->htag;
3598 dsl_pool_t *dp = ds->ds_dir->dd_pool;
3599 objset_t *mos = dp->dp_meta_objset;
3600 uint64_t now = gethrestime_sec();
3601 uint64_t zapobj;
3602
3603 mutex_enter(&ds->ds_lock);
3604 if (ds->ds_phys->ds_userrefs_obj == 0) {
3605 /*
3606 * This is the first user hold for this dataset. Create
3607 * the userrefs zap object.
3608 */
3609 dmu_buf_will_dirty(ds->ds_dbuf, tx);
3610 zapobj = ds->ds_phys->ds_userrefs_obj =
3611 zap_create(mos, DMU_OT_USERREFS, DMU_OT_NONE, 0, tx);
3612 } else {
3613 zapobj = ds->ds_phys->ds_userrefs_obj;
3614 }
3615 ds->ds_userrefs++;
3616 mutex_exit(&ds->ds_lock);
3617
3618 VERIFY(0 == zap_add(mos, zapobj, htag, 8, 1, &now, tx));
3619
3620 if (ha->temphold) {
3621 VERIFY(0 == dsl_pool_user_hold(dp, ds->ds_object,
3622 htag, &now, tx));
3623 }
3624
3625 spa_history_log_internal(LOG_DS_USER_HOLD,
3626 dp->dp_spa, tx, "<%s> temp = %d dataset = %llu", htag,
3627 (int)ha->temphold, ds->ds_object);
3628 }
3629
3630 static int
3631 dsl_dataset_user_hold_one(const char *dsname, void *arg)
3632 {
3633 struct dsl_ds_holdarg *ha = arg;
3634 dsl_dataset_t *ds;
3635 int error;
3636 char *name;
3637
3638 /* alloc a buffer to hold dsname@snapname plus terminating NULL */
3639 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3640 error = dsl_dataset_hold(name, ha->dstg, &ds);
3641 strfree(name);
3642 if (error == 0) {
3643 ha->gotone = B_TRUE;
3644 dsl_sync_task_create(ha->dstg, dsl_dataset_user_hold_check,
3645 dsl_dataset_user_hold_sync, ds, ha, 0);
3646 } else if (error == ENOENT && ha->recursive) {
3647 error = 0;
3648 } else {
3649 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3650 }
3651 return (error);
3652 }
3653
3654 int
3655 dsl_dataset_user_hold_for_send(dsl_dataset_t *ds, char *htag,
3656 boolean_t temphold)
3657 {
3658 struct dsl_ds_holdarg *ha;
3659 int error;
3660
3661 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3662 ha->htag = htag;
3663 ha->temphold = temphold;
3664 error = dsl_sync_task_do(ds->ds_dir->dd_pool,
3665 dsl_dataset_user_hold_check, dsl_dataset_user_hold_sync,
3666 ds, ha, 0);
3667 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3668
3669 return (error);
3670 }
3671
3672 int
3673 dsl_dataset_user_hold(char *dsname, char *snapname, char *htag,
3674 boolean_t recursive, boolean_t temphold, int cleanup_fd)
3675 {
3676 struct dsl_ds_holdarg *ha;
3677 dsl_sync_task_t *dst;
3678 spa_t *spa;
3679 int error;
3680 minor_t minor = 0;
3681
3682 if (cleanup_fd != -1) {
3683 /* Currently we only support cleanup-on-exit of tempholds. */
3684 if (!temphold)
3685 return (EINVAL);
3686 error = zfs_onexit_fd_hold(cleanup_fd, &minor);
3687 if (error)
3688 return (error);
3689 }
3690
3691 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3692
3693 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3694
3695 error = spa_open(dsname, &spa, FTAG);
3696 if (error) {
3697 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3698 if (cleanup_fd != -1)
3699 zfs_onexit_fd_rele(cleanup_fd);
3700 return (error);
3701 }
3702
3703 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
3704 ha->htag = htag;
3705 ha->snapname = snapname;
3706 ha->recursive = recursive;
3707 ha->temphold = temphold;
3708
3709 if (recursive) {
3710 error = dmu_objset_find(dsname, dsl_dataset_user_hold_one,
3711 ha, DS_FIND_CHILDREN);
3712 } else {
3713 error = dsl_dataset_user_hold_one(dsname, ha);
3714 }
3715 if (error == 0)
3716 error = dsl_sync_task_group_wait(ha->dstg);
3717
3718 for (dst = list_head(&ha->dstg->dstg_tasks); dst;
3719 dst = list_next(&ha->dstg->dstg_tasks, dst)) {
3720 dsl_dataset_t *ds = dst->dst_arg1;
3721
3722 if (dst->dst_err) {
3723 dsl_dataset_name(ds, ha->failed);
3724 *strchr(ha->failed, '@') = '\0';
3725 } else if (error == 0 && minor != 0 && temphold) {
3726 /*
3727 * If this hold is to be released upon process exit,
3728 * register that action now.
3729 */
3730 dsl_register_onexit_hold_cleanup(ds, htag, minor);
3731 }
3732 dsl_dataset_rele(ds, ha->dstg);
3733 }
3734
3735 if (error == 0 && recursive && !ha->gotone)
3736 error = ENOENT;
3737
3738 if (error)
3739 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed));
3740
3741 dsl_sync_task_group_destroy(ha->dstg);
3742
3743 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3744 spa_close(spa, FTAG);
3745 if (cleanup_fd != -1)
3746 zfs_onexit_fd_rele(cleanup_fd);
3747 return (error);
3748 }
3749
3750 struct dsl_ds_releasearg {
3751 dsl_dataset_t *ds;
3752 const char *htag;
3753 boolean_t own; /* do we own or just hold ds? */
3754 };
3755
3756 static int
3757 dsl_dataset_release_might_destroy(dsl_dataset_t *ds, const char *htag,
3758 boolean_t *might_destroy)
3759 {
3760 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
3761 uint64_t zapobj;
3762 uint64_t tmp;
3763 int error;
3764
3765 *might_destroy = B_FALSE;
3766
3767 mutex_enter(&ds->ds_lock);
3768 zapobj = ds->ds_phys->ds_userrefs_obj;
3769 if (zapobj == 0) {
3770 /* The tag can't possibly exist */
3771 mutex_exit(&ds->ds_lock);
3772 return (ESRCH);
3773 }
3774
3775 /* Make sure the tag exists */
3776 error = zap_lookup(mos, zapobj, htag, 8, 1, &tmp);
3777 if (error) {
3778 mutex_exit(&ds->ds_lock);
3779 if (error == ENOENT)
3780 error = ESRCH;
3781 return (error);
3782 }
3783
3784 if (ds->ds_userrefs == 1 && ds->ds_phys->ds_num_children == 1 &&
3785 DS_IS_DEFER_DESTROY(ds))
3786 *might_destroy = B_TRUE;
3787
3788 mutex_exit(&ds->ds_lock);
3789 return (0);
3790 }
3791
3792 static int
3793 dsl_dataset_user_release_check(void *arg1, void *tag, dmu_tx_t *tx)
3794 {
3795 struct dsl_ds_releasearg *ra = arg1;
3796 dsl_dataset_t *ds = ra->ds;
3797 boolean_t might_destroy;
3798 int error;
3799
3800 if (spa_version(ds->ds_dir->dd_pool->dp_spa) < SPA_VERSION_USERREFS)
3801 return (ENOTSUP);
3802
3803 error = dsl_dataset_release_might_destroy(ds, ra->htag, &might_destroy);
3804 if (error)
3805 return (error);
3806
3807 if (might_destroy) {
3808 struct dsl_ds_destroyarg dsda = {0};
3809
3810 if (dmu_tx_is_syncing(tx)) {
3811 /*
3812 * If we're not prepared to remove the snapshot,
3813 * we can't allow the release to happen right now.
3814 */
3815 if (!ra->own)
3816 return (EBUSY);
3817 }
3818 dsda.ds = ds;
3819 dsda.releasing = B_TRUE;
3820 return (dsl_dataset_destroy_check(&dsda, tag, tx));
3821 }
3822
3823 return (0);
3824 }
3825
3826 static void
3827 dsl_dataset_user_release_sync(void *arg1, void *tag, dmu_tx_t *tx)
3828 {
3829 struct dsl_ds_releasearg *ra = arg1;
3830 dsl_dataset_t *ds = ra->ds;
3831 dsl_pool_t *dp = ds->ds_dir->dd_pool;
3832 objset_t *mos = dp->dp_meta_objset;
3833 uint64_t zapobj;
3834 uint64_t dsobj = ds->ds_object;
3835 uint64_t refs;
3836 int error;
3837
3838 mutex_enter(&ds->ds_lock);
3839 ds->ds_userrefs--;
3840 refs = ds->ds_userrefs;
3841 mutex_exit(&ds->ds_lock);
3842 error = dsl_pool_user_release(dp, ds->ds_object, ra->htag, tx);
3843 VERIFY(error == 0 || error == ENOENT);
3844 zapobj = ds->ds_phys->ds_userrefs_obj;
3845 VERIFY(0 == zap_remove(mos, zapobj, ra->htag, tx));
3846 if (ds->ds_userrefs == 0 && ds->ds_phys->ds_num_children == 1 &&
3847 DS_IS_DEFER_DESTROY(ds)) {
3848 struct dsl_ds_destroyarg dsda = {0};
3849
3850 ASSERT(ra->own);
3851 dsda.ds = ds;
3852 dsda.releasing = B_TRUE;
3853 /* We already did the destroy_check */
3854 dsl_dataset_destroy_sync(&dsda, tag, tx);
3855 }
3856
3857 spa_history_log_internal(LOG_DS_USER_RELEASE,
3858 dp->dp_spa, tx, "<%s> %lld dataset = %llu",
3859 ra->htag, (longlong_t)refs, dsobj);
3860 }
3861
3862 static int
3863 dsl_dataset_user_release_one(const char *dsname, void *arg)
3864 {
3865 struct dsl_ds_holdarg *ha = arg;
3866 struct dsl_ds_releasearg *ra;
3867 dsl_dataset_t *ds;
3868 int error;
3869 void *dtag = ha->dstg;
3870 char *name;
3871 boolean_t own = B_FALSE;
3872 boolean_t might_destroy;
3873
3874 /* alloc a buffer to hold dsname@snapname, plus the terminating NULL */
3875 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3876 error = dsl_dataset_hold(name, dtag, &ds);
3877 strfree(name);
3878 if (error == ENOENT && ha->recursive)
3879 return (0);
3880 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3881 if (error)
3882 return (error);
3883
3884 ha->gotone = B_TRUE;
3885
3886 ASSERT(dsl_dataset_is_snapshot(ds));
3887
3888 error = dsl_dataset_release_might_destroy(ds, ha->htag, &might_destroy);
3889 if (error) {
3890 dsl_dataset_rele(ds, dtag);
3891 return (error);
3892 }
3893
3894 if (might_destroy) {
3895 #ifdef _KERNEL
3896 name = kmem_asprintf("%s@%s", dsname, ha->snapname);
3897 error = zfs_unmount_snap(name, NULL);
3898 strfree(name);
3899 if (error) {
3900 dsl_dataset_rele(ds, dtag);
3901 return (error);
3902 }
3903 #endif
3904 if (!dsl_dataset_tryown(ds, B_TRUE, dtag)) {
3905 dsl_dataset_rele(ds, dtag);
3906 return (EBUSY);
3907 } else {
3908 own = B_TRUE;
3909 dsl_dataset_make_exclusive(ds, dtag);
3910 }
3911 }
3912
3913 ra = kmem_alloc(sizeof (struct dsl_ds_releasearg), KM_SLEEP);
3914 ra->ds = ds;
3915 ra->htag = ha->htag;
3916 ra->own = own;
3917 dsl_sync_task_create(ha->dstg, dsl_dataset_user_release_check,
3918 dsl_dataset_user_release_sync, ra, dtag, 0);
3919
3920 return (0);
3921 }
3922
3923 int
3924 dsl_dataset_user_release(char *dsname, char *snapname, char *htag,
3925 boolean_t recursive)
3926 {
3927 struct dsl_ds_holdarg *ha;
3928 dsl_sync_task_t *dst;
3929 spa_t *spa;
3930 int error;
3931
3932 top:
3933 ha = kmem_zalloc(sizeof (struct dsl_ds_holdarg), KM_SLEEP);
3934
3935 (void) strlcpy(ha->failed, dsname, sizeof (ha->failed));
3936
3937 error = spa_open(dsname, &spa, FTAG);
3938 if (error) {
3939 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3940 return (error);
3941 }
3942
3943 ha->dstg = dsl_sync_task_group_create(spa_get_dsl(spa));
3944 ha->htag = htag;
3945 ha->snapname = snapname;
3946 ha->recursive = recursive;
3947 if (recursive) {
3948 error = dmu_objset_find(dsname, dsl_dataset_user_release_one,
3949 ha, DS_FIND_CHILDREN);
3950 } else {
3951 error = dsl_dataset_user_release_one(dsname, ha);
3952 }
3953 if (error == 0)
3954 error = dsl_sync_task_group_wait(ha->dstg);
3955
3956 for (dst = list_head(&ha->dstg->dstg_tasks); dst;
3957 dst = list_next(&ha->dstg->dstg_tasks, dst)) {
3958 struct dsl_ds_releasearg *ra = dst->dst_arg1;
3959 dsl_dataset_t *ds = ra->ds;
3960
3961 if (dst->dst_err)
3962 dsl_dataset_name(ds, ha->failed);
3963
3964 if (ra->own)
3965 dsl_dataset_disown(ds, ha->dstg);
3966 else
3967 dsl_dataset_rele(ds, ha->dstg);
3968
3969 kmem_free(ra, sizeof (struct dsl_ds_releasearg));
3970 }
3971
3972 if (error == 0 && recursive && !ha->gotone)
3973 error = ENOENT;
3974
3975 if (error && error != EBUSY)
3976 (void) strlcpy(dsname, ha->failed, sizeof (ha->failed));
3977
3978 dsl_sync_task_group_destroy(ha->dstg);
3979 kmem_free(ha, sizeof (struct dsl_ds_holdarg));
3980 spa_close(spa, FTAG);
3981
3982 /*
3983 * We can get EBUSY if we were racing with deferred destroy and
3984 * dsl_dataset_user_release_check() hadn't done the necessary
3985 * open context setup. We can also get EBUSY if we're racing
3986 * with destroy and that thread is the ds_owner. Either way
3987 * the busy condition should be transient, and we should retry
3988 * the release operation.
3989 */
3990 if (error == EBUSY)
3991 goto top;
3992
3993 return (error);
3994 }
3995
3996 /*
3997 * Called at spa_load time (with retry == B_FALSE) to release a stale
3998 * temporary user hold. Also called by the onexit code (with retry == B_TRUE).
3999 */
4000 int
4001 dsl_dataset_user_release_tmp(dsl_pool_t *dp, uint64_t dsobj, char *htag,
4002 boolean_t retry)
4003 {
4004 dsl_dataset_t *ds;
4005 char *snap;
4006 char *name;
4007 int namelen;
4008 int error;
4009
4010 do {
4011 rw_enter(&dp->dp_config_rwlock, RW_READER);
4012 error = dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds);
4013 rw_exit(&dp->dp_config_rwlock);
4014 if (error)
4015 return (error);
4016 namelen = dsl_dataset_namelen(ds)+1;
4017 name = kmem_alloc(namelen, KM_SLEEP);
4018 dsl_dataset_name(ds, name);
4019 dsl_dataset_rele(ds, FTAG);
4020
4021 snap = strchr(name, '@');
4022 *snap = '\0';
4023 ++snap;
4024 error = dsl_dataset_user_release(name, snap, htag, B_FALSE);
4025 kmem_free(name, namelen);
4026
4027 /*
4028 * The object can't have been destroyed because we have a hold,
4029 * but it might have been renamed, resulting in ENOENT. Retry
4030 * if we've been requested to do so.
4031 *
4032 * It would be nice if we could use the dsobj all the way
4033 * through and avoid ENOENT entirely. But we might need to
4034 * unmount the snapshot, and there's currently no way to lookup
4035 * a vfsp using a ZFS object id.
4036 */
4037 } while ((error == ENOENT) && retry);
4038
4039 return (error);
4040 }
4041
4042 int
4043 dsl_dataset_get_holds(const char *dsname, nvlist_t **nvp)
4044 {
4045 dsl_dataset_t *ds;
4046 int err;
4047
4048 err = dsl_dataset_hold(dsname, FTAG, &ds);
4049 if (err)
4050 return (err);
4051
4052 VERIFY(0 == nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP));
4053 if (ds->ds_phys->ds_userrefs_obj != 0) {
4054 zap_attribute_t *za;
4055 zap_cursor_t zc;
4056
4057 za = kmem_alloc(sizeof (zap_attribute_t), KM_SLEEP);
4058 for (zap_cursor_init(&zc, ds->ds_dir->dd_pool->dp_meta_objset,
4059 ds->ds_phys->ds_userrefs_obj);
4060 zap_cursor_retrieve(&zc, za) == 0;
4061 zap_cursor_advance(&zc)) {
4062 VERIFY(0 == nvlist_add_uint64(*nvp, za->za_name,
4063 za->za_first_integer));
4064 }
4065 zap_cursor_fini(&zc);
4066 kmem_free(za, sizeof (zap_attribute_t));
4067 }
4068 dsl_dataset_rele(ds, FTAG);
4069 return (0);
4070 }
4071
4072 /*
4073 * Note, this function is used as the callback for dmu_objset_find(). We
4074 * always return 0 so that we will continue to find and process
4075 * inconsistent datasets, even if we encounter an error trying to
4076 * process one of them.
4077 */
4078 /* ARGSUSED */
4079 int
4080 dsl_destroy_inconsistent(const char *dsname, void *arg)
4081 {
4082 dsl_dataset_t *ds;
4083
4084 if (dsl_dataset_own(dsname, B_TRUE, FTAG, &ds) == 0) {
4085 if (DS_IS_INCONSISTENT(ds))
4086 (void) dsl_dataset_destroy(ds, FTAG, B_FALSE);
4087 else
4088 dsl_dataset_disown(ds, FTAG);
4089 }
4090 return (0);
4091 }
4092
4093 /*
4094 * Return (in *usedp) the amount of space written in new that is not
4095 * present in oldsnap. New may be a snapshot or the head. Old must be
4096 * a snapshot before new, in new's filesystem (or its origin). If not then
4097 * fail and return EINVAL.
4098 *
4099 * The written space is calculated by considering two components: First, we
4100 * ignore any freed space, and calculate the written as new's used space
4101 * minus old's used space. Next, we add in the amount of space that was freed
4102 * between the two snapshots, thus reducing new's used space relative to old's.
4103 * Specifically, this is the space that was born before old->ds_creation_txg,
4104 * and freed before new (ie. on new's deadlist or a previous deadlist).
4105 *
4106 * space freed [---------------------]
4107 * snapshots ---O-------O--------O-------O------
4108 * oldsnap new
4109 */
4110 int
4111 dsl_dataset_space_written(dsl_dataset_t *oldsnap, dsl_dataset_t *new,
4112 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
4113 {
4114 int err = 0;
4115 uint64_t snapobj;
4116 dsl_pool_t *dp = new->ds_dir->dd_pool;
4117
4118 *usedp = 0;
4119 *usedp += new->ds_phys->ds_used_bytes;
4120 *usedp -= oldsnap->ds_phys->ds_used_bytes;
4121
4122 *compp = 0;
4123 *compp += new->ds_phys->ds_compressed_bytes;
4124 *compp -= oldsnap->ds_phys->ds_compressed_bytes;
4125
4126 *uncompp = 0;
4127 *uncompp += new->ds_phys->ds_uncompressed_bytes;
4128 *uncompp -= oldsnap->ds_phys->ds_uncompressed_bytes;
4129
4130 rw_enter(&dp->dp_config_rwlock, RW_READER);
4131 snapobj = new->ds_object;
4132 while (snapobj != oldsnap->ds_object) {
4133 dsl_dataset_t *snap;
4134 uint64_t used, comp, uncomp;
4135
4136 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &snap);
4137 if (err != 0)
4138 break;
4139
4140 if (snap->ds_phys->ds_prev_snap_txg ==
4141 oldsnap->ds_phys->ds_creation_txg) {
4142 /*
4143 * The blocks in the deadlist can not be born after
4144 * ds_prev_snap_txg, so get the whole deadlist space,
4145 * which is more efficient (especially for old-format
4146 * deadlists). Unfortunately the deadlist code
4147 * doesn't have enough information to make this
4148 * optimization itself.
4149 */
4150 dsl_deadlist_space(&snap->ds_deadlist,
4151 &used, &comp, &uncomp);
4152 } else {
4153 dsl_deadlist_space_range(&snap->ds_deadlist,
4154 0, oldsnap->ds_phys->ds_creation_txg,
4155 &used, &comp, &uncomp);
4156 }
4157 *usedp += used;
4158 *compp += comp;
4159 *uncompp += uncomp;
4160
4161 /*
4162 * If we get to the beginning of the chain of snapshots
4163 * (ds_prev_snap_obj == 0) before oldsnap, then oldsnap
4164 * was not a snapshot of/before new.
4165 */
4166 snapobj = snap->ds_phys->ds_prev_snap_obj;
4167 dsl_dataset_rele(snap, FTAG);
4168 if (snapobj == 0) {
4169 err = EINVAL;
4170 break;
4171 }
4172
4173 }
4174 rw_exit(&dp->dp_config_rwlock);
4175 return (err);
4176 }
4177
4178 /*
4179 * Return (in *usedp) the amount of space that will be reclaimed if firstsnap,
4180 * lastsnap, and all snapshots in between are deleted.
4181 *
4182 * blocks that would be freed [---------------------------]
4183 * snapshots ---O-------O--------O-------O--------O
4184 * firstsnap lastsnap
4185 *
4186 * This is the set of blocks that were born after the snap before firstsnap,
4187 * (birth > firstsnap->prev_snap_txg) and died before the snap after the
4188 * last snap (ie, is on lastsnap->ds_next->ds_deadlist or an earlier deadlist).
4189 * We calculate this by iterating over the relevant deadlists (from the snap
4190 * after lastsnap, backward to the snap after firstsnap), summing up the
4191 * space on the deadlist that was born after the snap before firstsnap.
4192 */
4193 int
4194 dsl_dataset_space_wouldfree(dsl_dataset_t *firstsnap,
4195 dsl_dataset_t *lastsnap,
4196 uint64_t *usedp, uint64_t *compp, uint64_t *uncompp)
4197 {
4198 int err = 0;
4199 uint64_t snapobj;
4200 dsl_pool_t *dp = firstsnap->ds_dir->dd_pool;
4201
4202 ASSERT(dsl_dataset_is_snapshot(firstsnap));
4203 ASSERT(dsl_dataset_is_snapshot(lastsnap));
4204
4205 /*
4206 * Check that the snapshots are in the same dsl_dir, and firstsnap
4207 * is before lastsnap.
4208 */
4209 if (firstsnap->ds_dir != lastsnap->ds_dir ||
4210 firstsnap->ds_phys->ds_creation_txg >
4211 lastsnap->ds_phys->ds_creation_txg)
4212 return (EINVAL);
4213
4214 *usedp = *compp = *uncompp = 0;
4215
4216 rw_enter(&dp->dp_config_rwlock, RW_READER);
4217 snapobj = lastsnap->ds_phys->ds_next_snap_obj;
4218 while (snapobj != firstsnap->ds_object) {
4219 dsl_dataset_t *ds;
4220 uint64_t used, comp, uncomp;
4221
4222 err = dsl_dataset_hold_obj(dp, snapobj, FTAG, &ds);
4223 if (err != 0)
4224 break;
4225
4226 dsl_deadlist_space_range(&ds->ds_deadlist,
4227 firstsnap->ds_phys->ds_prev_snap_txg, UINT64_MAX,
4228 &used, &comp, &uncomp);
4229 *usedp += used;
4230 *compp += comp;
4231 *uncompp += uncomp;
4232
4233 snapobj = ds->ds_phys->ds_prev_snap_obj;
4234 ASSERT3U(snapobj, !=, 0);
4235 dsl_dataset_rele(ds, FTAG);
4236 }
4237 rw_exit(&dp->dp_config_rwlock);
4238 return (err);
4239 }
Unleashed OS