1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
23 * Copyright (c) 2012, 2014 by Delphix. All rights reserved.
24 * Copyright (c) 2013 Steven Hartland. All rights reserved.
25 * Copyright (c) 2013 by Joyent, Inc. All rights reserved.
26 */
27
28 #include <sys/zfs_context.h>
29 #include <sys/dsl_userhold.h>
30 #include <sys/dsl_dataset.h>
31 #include <sys/dsl_synctask.h>
32 #include <sys/dmu_tx.h>
33 #include <sys/dsl_pool.h>
34 #include <sys/dsl_dir.h>
35 #include <sys/dmu_traverse.h>
36 #include <sys/dsl_scan.h>
37 #include <sys/dmu_objset.h>
38 #include <sys/zap.h>
39 #include <sys/zfeature.h>
40 #include <sys/zfs_ioctl.h>
41 #include <sys/dsl_deleg.h>
42 #include <sys/dmu_impl.h>
43
44 typedef struct dmu_snapshots_destroy_arg {
45 nvlist_t *dsda_snaps;
46 nvlist_t *dsda_successful_snaps;
47 boolean_t dsda_defer;
48 nvlist_t *dsda_errlist;
49 } dmu_snapshots_destroy_arg_t;
50
51 int
52 dsl_destroy_snapshot_check_impl(dsl_dataset_t *ds, boolean_t defer)
53 {
54 if (!ds->ds_is_snapshot)
55 return (SET_ERROR(EINVAL));
56
57 if (dsl_dataset_long_held(ds))
58 return (SET_ERROR(EBUSY));
59
60 /*
61 * Only allow deferred destroy on pools that support it.
62 * NOTE: deferred destroy is only supported on snapshots.
63 */
64 if (defer) {
65 if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
66 SPA_VERSION_USERREFS)
67 return (SET_ERROR(ENOTSUP));
68 return (0);
69 }
70
71 /*
72 * If this snapshot has an elevated user reference count,
73 * we can't destroy it yet.
74 */
75 if (ds->ds_userrefs > 0)
76 return (SET_ERROR(EBUSY));
77
78 /*
79 * Can't delete a branch point.
80 */
81 if (dsl_dataset_phys(ds)->ds_num_children > 1)
82 return (SET_ERROR(EEXIST));
83
84 return (0);
85 }
86
87 static int
88 dsl_destroy_snapshot_check(void *arg, dmu_tx_t *tx)
89 {
90 dmu_snapshots_destroy_arg_t *dsda = arg;
91 dsl_pool_t *dp = dmu_tx_pool(tx);
92 nvpair_t *pair;
93 int error = 0;
94
95 if (!dmu_tx_is_syncing(tx))
96 return (0);
97
98 for (pair = nvlist_next_nvpair(dsda->dsda_snaps, NULL);
99 pair != NULL; pair = nvlist_next_nvpair(dsda->dsda_snaps, pair)) {
100 dsl_dataset_t *ds;
101
102 error = dsl_dataset_hold(dp, nvpair_name(pair),
103 FTAG, &ds);
104
105 /*
106 * If the snapshot does not exist, silently ignore it
107 * (it's "already destroyed").
108 */
109 if (error == ENOENT)
110 continue;
111
112 if (error == 0) {
113 error = dsl_destroy_snapshot_check_impl(ds,
114 dsda->dsda_defer);
115 dsl_dataset_rele(ds, FTAG);
116 }
117
118 if (error == 0) {
119 fnvlist_add_boolean(dsda->dsda_successful_snaps,
120 nvpair_name(pair));
121 } else {
122 fnvlist_add_int32(dsda->dsda_errlist,
123 nvpair_name(pair), error);
124 }
125 }
126
127 pair = nvlist_next_nvpair(dsda->dsda_errlist, NULL);
128 if (pair != NULL)
129 return (fnvpair_value_int32(pair));
130
131 return (0);
132 }
133
134 struct process_old_arg {
135 dsl_dataset_t *ds;
136 dsl_dataset_t *ds_prev;
137 boolean_t after_branch_point;
138 zio_t *pio;
139 uint64_t used, comp, uncomp;
140 };
141
142 static int
143 process_old_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
144 {
145 struct process_old_arg *poa = arg;
146 dsl_pool_t *dp = poa->ds->ds_dir->dd_pool;
147
148 ASSERT(!BP_IS_HOLE(bp));
149
150 if (bp->blk_birth <= dsl_dataset_phys(poa->ds)->ds_prev_snap_txg) {
151 dsl_deadlist_insert(&poa->ds->ds_deadlist, bp, tx);
152 if (poa->ds_prev && !poa->after_branch_point &&
153 bp->blk_birth >
154 dsl_dataset_phys(poa->ds_prev)->ds_prev_snap_txg) {
155 dsl_dataset_phys(poa->ds_prev)->ds_unique_bytes +=
156 bp_get_dsize_sync(dp->dp_spa, bp);
157 }
158 } else {
159 poa->used += bp_get_dsize_sync(dp->dp_spa, bp);
160 poa->comp += BP_GET_PSIZE(bp);
161 poa->uncomp += BP_GET_UCSIZE(bp);
162 dsl_free_sync(poa->pio, dp, tx->tx_txg, bp);
163 }
164 return (0);
165 }
166
167 static void
168 process_old_deadlist(dsl_dataset_t *ds, dsl_dataset_t *ds_prev,
169 dsl_dataset_t *ds_next, boolean_t after_branch_point, dmu_tx_t *tx)
170 {
171 struct process_old_arg poa = { 0 };
172 dsl_pool_t *dp = ds->ds_dir->dd_pool;
173 objset_t *mos = dp->dp_meta_objset;
174 uint64_t deadlist_obj;
175
176 ASSERT(ds->ds_deadlist.dl_oldfmt);
177 ASSERT(ds_next->ds_deadlist.dl_oldfmt);
178
179 poa.ds = ds;
180 poa.ds_prev = ds_prev;
181 poa.after_branch_point = after_branch_point;
182 poa.pio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
183 VERIFY0(bpobj_iterate(&ds_next->ds_deadlist.dl_bpobj,
184 process_old_cb, &poa, tx));
185 VERIFY0(zio_wait(poa.pio));
186 ASSERT3U(poa.used, ==, dsl_dataset_phys(ds)->ds_unique_bytes);
187
188 /* change snapused */
189 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
190 -poa.used, -poa.comp, -poa.uncomp, tx);
191
192 /* swap next's deadlist to our deadlist */
193 dsl_deadlist_close(&ds->ds_deadlist);
194 dsl_deadlist_close(&ds_next->ds_deadlist);
195 deadlist_obj = dsl_dataset_phys(ds)->ds_deadlist_obj;
196 dsl_dataset_phys(ds)->ds_deadlist_obj =
197 dsl_dataset_phys(ds_next)->ds_deadlist_obj;
198 dsl_dataset_phys(ds_next)->ds_deadlist_obj = deadlist_obj;
199 dsl_deadlist_open(&ds->ds_deadlist, mos,
200 dsl_dataset_phys(ds)->ds_deadlist_obj);
201 dsl_deadlist_open(&ds_next->ds_deadlist, mos,
202 dsl_dataset_phys(ds_next)->ds_deadlist_obj);
203 }
204
205 static void
206 dsl_dataset_remove_clones_key(dsl_dataset_t *ds, uint64_t mintxg, dmu_tx_t *tx)
207 {
208 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
209 zap_cursor_t zc;
210 zap_attribute_t za;
211
212 /*
213 * If it is the old version, dd_clones doesn't exist so we can't
214 * find the clones, but dsl_deadlist_remove_key() is a no-op so it
215 * doesn't matter.
216 */
217 if (dsl_dir_phys(ds->ds_dir)->dd_clones == 0)
218 return;
219
220 for (zap_cursor_init(&zc, mos, dsl_dir_phys(ds->ds_dir)->dd_clones);
221 zap_cursor_retrieve(&zc, &za) == 0;
222 zap_cursor_advance(&zc)) {
223 dsl_dataset_t *clone;
224
225 VERIFY0(dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
226 za.za_first_integer, FTAG, &clone));
227 if (clone->ds_dir->dd_origin_txg > mintxg) {
228 dsl_deadlist_remove_key(&clone->ds_deadlist,
229 mintxg, tx);
230 dsl_dataset_remove_clones_key(clone, mintxg, tx);
231 }
232 dsl_dataset_rele(clone, FTAG);
233 }
234 zap_cursor_fini(&zc);
235 }
236
237 void
238 dsl_destroy_snapshot_sync_impl(dsl_dataset_t *ds, boolean_t defer, dmu_tx_t *tx)
239 {
240 int err;
241 int after_branch_point = FALSE;
242 dsl_pool_t *dp = ds->ds_dir->dd_pool;
243 objset_t *mos = dp->dp_meta_objset;
244 dsl_dataset_t *ds_prev = NULL;
245 uint64_t obj;
246
247 ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
248 ASSERT3U(dsl_dataset_phys(ds)->ds_bp.blk_birth, <=, tx->tx_txg);
249 ASSERT(refcount_is_zero(&ds->ds_longholds));
250
251 if (defer &&
252 (ds->ds_userrefs > 0 ||
253 dsl_dataset_phys(ds)->ds_num_children > 1)) {
254 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
255 dmu_buf_will_dirty(ds->ds_dbuf, tx);
256 dsl_dataset_phys(ds)->ds_flags |= DS_FLAG_DEFER_DESTROY;
257 spa_history_log_internal_ds(ds, "defer_destroy", tx, "");
258 return;
259 }
260
261 ASSERT3U(dsl_dataset_phys(ds)->ds_num_children, <=, 1);
262
263 /* We need to log before removing it from the namespace. */
264 spa_history_log_internal_ds(ds, "destroy", tx, "");
265
266 dsl_scan_ds_destroyed(ds, tx);
267
268 obj = ds->ds_object;
269
270 if (ds->ds_large_blocks) {
271 ASSERT0(zap_contains(mos, obj, DS_FIELD_LARGE_BLOCKS));
272 spa_feature_decr(dp->dp_spa, SPA_FEATURE_LARGE_BLOCKS, tx);
273 }
274 if (dsl_dataset_phys(ds)->ds_prev_snap_obj != 0) {
275 ASSERT3P(ds->ds_prev, ==, NULL);
276 VERIFY0(dsl_dataset_hold_obj(dp,
277 dsl_dataset_phys(ds)->ds_prev_snap_obj, FTAG, &ds_prev));
278 after_branch_point =
279 (dsl_dataset_phys(ds_prev)->ds_next_snap_obj != obj);
280
281 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx);
282 if (after_branch_point &&
283 dsl_dataset_phys(ds_prev)->ds_next_clones_obj != 0) {
284 dsl_dataset_remove_from_next_clones(ds_prev, obj, tx);
285 if (dsl_dataset_phys(ds)->ds_next_snap_obj != 0) {
286 VERIFY0(zap_add_int(mos,
287 dsl_dataset_phys(ds_prev)->
288 ds_next_clones_obj,
289 dsl_dataset_phys(ds)->ds_next_snap_obj,
290 tx));
291 }
292 }
293 if (!after_branch_point) {
294 dsl_dataset_phys(ds_prev)->ds_next_snap_obj =
295 dsl_dataset_phys(ds)->ds_next_snap_obj;
296 }
297 }
298
299 dsl_dataset_t *ds_next;
300 uint64_t old_unique;
301 uint64_t used = 0, comp = 0, uncomp = 0;
302
303 VERIFY0(dsl_dataset_hold_obj(dp,
304 dsl_dataset_phys(ds)->ds_next_snap_obj, FTAG, &ds_next));
305 ASSERT3U(dsl_dataset_phys(ds_next)->ds_prev_snap_obj, ==, obj);
306
307 old_unique = dsl_dataset_phys(ds_next)->ds_unique_bytes;
308
309 dmu_buf_will_dirty(ds_next->ds_dbuf, tx);
310 dsl_dataset_phys(ds_next)->ds_prev_snap_obj =
311 dsl_dataset_phys(ds)->ds_prev_snap_obj;
312 dsl_dataset_phys(ds_next)->ds_prev_snap_txg =
313 dsl_dataset_phys(ds)->ds_prev_snap_txg;
314 ASSERT3U(dsl_dataset_phys(ds)->ds_prev_snap_txg, ==,
315 ds_prev ? dsl_dataset_phys(ds_prev)->ds_creation_txg : 0);
316
317 if (ds_next->ds_deadlist.dl_oldfmt) {
318 process_old_deadlist(ds, ds_prev, ds_next,
319 after_branch_point, tx);
320 } else {
321 /* Adjust prev's unique space. */
322 if (ds_prev && !after_branch_point) {
323 dsl_deadlist_space_range(&ds_next->ds_deadlist,
324 dsl_dataset_phys(ds_prev)->ds_prev_snap_txg,
325 dsl_dataset_phys(ds)->ds_prev_snap_txg,
326 &used, &comp, &uncomp);
327 dsl_dataset_phys(ds_prev)->ds_unique_bytes += used;
328 }
329
330 /* Adjust snapused. */
331 dsl_deadlist_space_range(&ds_next->ds_deadlist,
332 dsl_dataset_phys(ds)->ds_prev_snap_txg, UINT64_MAX,
333 &used, &comp, &uncomp);
334 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
335 -used, -comp, -uncomp, tx);
336
337 /* Move blocks to be freed to pool's free list. */
338 dsl_deadlist_move_bpobj(&ds_next->ds_deadlist,
339 &dp->dp_free_bpobj, dsl_dataset_phys(ds)->ds_prev_snap_txg,
340 tx);
341 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir,
342 DD_USED_HEAD, used, comp, uncomp, tx);
343
344 /* Merge our deadlist into next's and free it. */
345 dsl_deadlist_merge(&ds_next->ds_deadlist,
346 dsl_dataset_phys(ds)->ds_deadlist_obj, tx);
347 }
348 dsl_deadlist_close(&ds->ds_deadlist);
349 dsl_deadlist_free(mos, dsl_dataset_phys(ds)->ds_deadlist_obj, tx);
350 dmu_buf_will_dirty(ds->ds_dbuf, tx);
351 dsl_dataset_phys(ds)->ds_deadlist_obj = 0;
352
353 /* Collapse range in clone heads */
354 dsl_dataset_remove_clones_key(ds,
355 dsl_dataset_phys(ds)->ds_creation_txg, tx);
356
357 if (ds_next->ds_is_snapshot) {
358 dsl_dataset_t *ds_nextnext;
359
360 /*
361 * Update next's unique to include blocks which
362 * were previously shared by only this snapshot
363 * and it. Those blocks will be born after the
364 * prev snap and before this snap, and will have
365 * died after the next snap and before the one
366 * after that (ie. be on the snap after next's
367 * deadlist).
368 */
369 VERIFY0(dsl_dataset_hold_obj(dp,
370 dsl_dataset_phys(ds_next)->ds_next_snap_obj,
371 FTAG, &ds_nextnext));
372 dsl_deadlist_space_range(&ds_nextnext->ds_deadlist,
373 dsl_dataset_phys(ds)->ds_prev_snap_txg,
374 dsl_dataset_phys(ds)->ds_creation_txg,
375 &used, &comp, &uncomp);
376 dsl_dataset_phys(ds_next)->ds_unique_bytes += used;
377 dsl_dataset_rele(ds_nextnext, FTAG);
378 ASSERT3P(ds_next->ds_prev, ==, NULL);
379
380 /* Collapse range in this head. */
381 dsl_dataset_t *hds;
382 VERIFY0(dsl_dataset_hold_obj(dp,
383 dsl_dir_phys(ds->ds_dir)->dd_head_dataset_obj, FTAG, &hds));
384 dsl_deadlist_remove_key(&hds->ds_deadlist,
385 dsl_dataset_phys(ds)->ds_creation_txg, tx);
386 dsl_dataset_rele(hds, FTAG);
387
388 } else {
389 ASSERT3P(ds_next->ds_prev, ==, ds);
390 dsl_dataset_rele(ds_next->ds_prev, ds_next);
391 ds_next->ds_prev = NULL;
392 if (ds_prev) {
393 VERIFY0(dsl_dataset_hold_obj(dp,
394 dsl_dataset_phys(ds)->ds_prev_snap_obj,
395 ds_next, &ds_next->ds_prev));
396 }
397
398 dsl_dataset_recalc_head_uniq(ds_next);
399
400 /*
401 * Reduce the amount of our unconsumed refreservation
402 * being charged to our parent by the amount of
403 * new unique data we have gained.
404 */
405 if (old_unique < ds_next->ds_reserved) {
406 int64_t mrsdelta;
407 uint64_t new_unique =
408 dsl_dataset_phys(ds_next)->ds_unique_bytes;
409
410 ASSERT(old_unique <= new_unique);
411 mrsdelta = MIN(new_unique - old_unique,
412 ds_next->ds_reserved - old_unique);
413 dsl_dir_diduse_space(ds->ds_dir,
414 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx);
415 }
416 }
417 dsl_dataset_rele(ds_next, FTAG);
418
419 /*
420 * This must be done after the dsl_traverse(), because it will
421 * re-open the objset.
422 */
423 if (ds->ds_objset) {
424 dmu_objset_evict(ds->ds_objset);
425 ds->ds_objset = NULL;
426 }
427
428 /* remove from snapshot namespace */
429 dsl_dataset_t *ds_head;
430 ASSERT(dsl_dataset_phys(ds)->ds_snapnames_zapobj == 0);
431 VERIFY0(dsl_dataset_hold_obj(dp,
432 dsl_dir_phys(ds->ds_dir)->dd_head_dataset_obj, FTAG, &ds_head));
433 VERIFY0(dsl_dataset_get_snapname(ds));
434 #ifdef ZFS_DEBUG
435 {
436 uint64_t val;
437
438 err = dsl_dataset_snap_lookup(ds_head,
439 ds->ds_snapname, &val);
440 ASSERT0(err);
441 ASSERT3U(val, ==, obj);
442 }
443 #endif
444 VERIFY0(dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx, B_TRUE));
445 dsl_dataset_rele(ds_head, FTAG);
446
447 if (ds_prev != NULL)
448 dsl_dataset_rele(ds_prev, FTAG);
449
450 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx);
451
452 if (dsl_dataset_phys(ds)->ds_next_clones_obj != 0) {
453 uint64_t count;
454 ASSERT0(zap_count(mos,
455 dsl_dataset_phys(ds)->ds_next_clones_obj, &count) &&
456 count == 0);
457 VERIFY0(dmu_object_free(mos,
458 dsl_dataset_phys(ds)->ds_next_clones_obj, tx));
459 }
460 if (dsl_dataset_phys(ds)->ds_props_obj != 0)
461 VERIFY0(zap_destroy(mos, dsl_dataset_phys(ds)->ds_props_obj,
462 tx));
463 if (dsl_dataset_phys(ds)->ds_userrefs_obj != 0)
464 VERIFY0(zap_destroy(mos, dsl_dataset_phys(ds)->ds_userrefs_obj,
465 tx));
466 dsl_dir_rele(ds->ds_dir, ds);
467 ds->ds_dir = NULL;
468 dmu_object_free_zapified(mos, obj, tx);
469 }
470
471 static void
472 dsl_destroy_snapshot_sync(void *arg, dmu_tx_t *tx)
473 {
474 dmu_snapshots_destroy_arg_t *dsda = arg;
475 dsl_pool_t *dp = dmu_tx_pool(tx);
476 nvpair_t *pair;
477
478 for (pair = nvlist_next_nvpair(dsda->dsda_successful_snaps, NULL);
479 pair != NULL;
480 pair = nvlist_next_nvpair(dsda->dsda_successful_snaps, pair)) {
481 dsl_dataset_t *ds;
482
483 VERIFY0(dsl_dataset_hold(dp, nvpair_name(pair), FTAG, &ds));
484
485 dsl_destroy_snapshot_sync_impl(ds, dsda->dsda_defer, tx);
486 dsl_dataset_rele(ds, FTAG);
487 }
488 }
489
490 /*
491 * The semantics of this function are described in the comment above
492 * lzc_destroy_snaps(). To summarize:
493 *
494 * The snapshots must all be in the same pool.
495 *
496 * Snapshots that don't exist will be silently ignored (considered to be
497 * "already deleted").
498 *
499 * On success, all snaps will be destroyed and this will return 0.
500 * On failure, no snaps will be destroyed, the errlist will be filled in,
501 * and this will return an errno.
502 */
503 int
504 dsl_destroy_snapshots_nvl(nvlist_t *snaps, boolean_t defer,
505 nvlist_t *errlist)
506 {
507 dmu_snapshots_destroy_arg_t dsda;
508 int error;
509 nvpair_t *pair;
510
511 pair = nvlist_next_nvpair(snaps, NULL);
512 if (pair == NULL)
513 return (0);
514
515 dsda.dsda_snaps = snaps;
516 dsda.dsda_successful_snaps = fnvlist_alloc();
517 dsda.dsda_defer = defer;
518 dsda.dsda_errlist = errlist;
519
520 error = dsl_sync_task(nvpair_name(pair),
521 dsl_destroy_snapshot_check, dsl_destroy_snapshot_sync,
522 &dsda, 0, ZFS_SPACE_CHECK_NONE);
523 fnvlist_free(dsda.dsda_successful_snaps);
524
525 return (error);
526 }
527
528 int
529 dsl_destroy_snapshot(const char *name, boolean_t defer)
530 {
531 int error;
532 nvlist_t *nvl = fnvlist_alloc();
533 nvlist_t *errlist = fnvlist_alloc();
534
535 fnvlist_add_boolean(nvl, name);
536 error = dsl_destroy_snapshots_nvl(nvl, defer, errlist);
537 fnvlist_free(errlist);
538 fnvlist_free(nvl);
539 return (error);
540 }
541
542 struct killarg {
543 dsl_dataset_t *ds;
544 dmu_tx_t *tx;
545 };
546
547 /* ARGSUSED */
548 static int
549 kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
550 const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
551 {
552 struct killarg *ka = arg;
553 dmu_tx_t *tx = ka->tx;
554
555 if (BP_IS_HOLE(bp) || BP_IS_EMBEDDED(bp))
556 return (0);
557
558 if (zb->zb_level == ZB_ZIL_LEVEL) {
559 ASSERT(zilog != NULL);
560 /*
561 * It's a block in the intent log. It has no
562 * accounting, so just free it.
563 */
564 dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp);
565 } else {
566 ASSERT(zilog == NULL);
567 ASSERT3U(bp->blk_birth, >,
568 dsl_dataset_phys(ka->ds)->ds_prev_snap_txg);
569 (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE);
570 }
571
572 return (0);
573 }
574
575 static void
576 old_synchronous_dataset_destroy(dsl_dataset_t *ds, dmu_tx_t *tx)
577 {
578 struct killarg ka;
579
580 /*
581 * Free everything that we point to (that's born after
582 * the previous snapshot, if we are a clone)
583 *
584 * NB: this should be very quick, because we already
585 * freed all the objects in open context.
586 */
587 ka.ds = ds;
588 ka.tx = tx;
589 VERIFY0(traverse_dataset(ds,
590 dsl_dataset_phys(ds)->ds_prev_snap_txg, TRAVERSE_POST,
591 kill_blkptr, &ka));
592 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) ||
593 dsl_dataset_phys(ds)->ds_unique_bytes == 0);
594 }
595
596 typedef struct dsl_destroy_head_arg {
597 const char *ddha_name;
598 } dsl_destroy_head_arg_t;
599
600 int
601 dsl_destroy_head_check_impl(dsl_dataset_t *ds, int expected_holds)
602 {
603 int error;
604 uint64_t count;
605 objset_t *mos;
606
607 ASSERT(!ds->ds_is_snapshot);
608 if (ds->ds_is_snapshot)
609 return (SET_ERROR(EINVAL));
610
611 if (refcount_count(&ds->ds_longholds) != expected_holds)
612 return (SET_ERROR(EBUSY));
613
614 mos = ds->ds_dir->dd_pool->dp_meta_objset;
615
616 /*
617 * Can't delete a head dataset if there are snapshots of it.
618 * (Except if the only snapshots are from the branch we cloned
619 * from.)
620 */
621 if (ds->ds_prev != NULL &&
622 dsl_dataset_phys(ds->ds_prev)->ds_next_snap_obj == ds->ds_object)
623 return (SET_ERROR(EBUSY));
624
625 /*
626 * Can't delete if there are children of this fs.
627 */
628 error = zap_count(mos,
629 dsl_dir_phys(ds->ds_dir)->dd_child_dir_zapobj, &count);
630 if (error != 0)
631 return (error);
632 if (count != 0)
633 return (SET_ERROR(EEXIST));
634
635 if (dsl_dir_is_clone(ds->ds_dir) && DS_IS_DEFER_DESTROY(ds->ds_prev) &&
636 dsl_dataset_phys(ds->ds_prev)->ds_num_children == 2 &&
637 ds->ds_prev->ds_userrefs == 0) {
638 /* We need to remove the origin snapshot as well. */
639 if (!refcount_is_zero(&ds->ds_prev->ds_longholds))
640 return (SET_ERROR(EBUSY));
641 }
642 return (0);
643 }
644
645 static int
646 dsl_destroy_head_check(void *arg, dmu_tx_t *tx)
647 {
648 dsl_destroy_head_arg_t *ddha = arg;
649 dsl_pool_t *dp = dmu_tx_pool(tx);
650 dsl_dataset_t *ds;
651 int error;
652
653 error = dsl_dataset_hold(dp, ddha->ddha_name, FTAG, &ds);
654 if (error != 0)
655 return (error);
656
657 error = dsl_destroy_head_check_impl(ds, 0);
658 dsl_dataset_rele(ds, FTAG);
659 return (error);
660 }
661
662 static void
663 dsl_dir_destroy_sync(uint64_t ddobj, dmu_tx_t *tx)
664 {
665 dsl_dir_t *dd;
666 dsl_pool_t *dp = dmu_tx_pool(tx);
667 objset_t *mos = dp->dp_meta_objset;
668 dd_used_t t;
669
670 ASSERT(RRW_WRITE_HELD(&dmu_tx_pool(tx)->dp_config_rwlock));
671
672 VERIFY0(dsl_dir_hold_obj(dp, ddobj, NULL, FTAG, &dd));
673
674 ASSERT0(dsl_dir_phys(dd)->dd_head_dataset_obj);
675
676 /*
677 * Decrement the filesystem count for all parent filesystems.
678 *
679 * When we receive an incremental stream into a filesystem that already
680 * exists, a temporary clone is created. We never count this temporary
681 * clone, whose name begins with a '%'.
682 */
683 if (dd->dd_myname[0] != '%' && dd->dd_parent != NULL)
684 dsl_fs_ss_count_adjust(dd->dd_parent, -1,
685 DD_FIELD_FILESYSTEM_COUNT, tx);
686
687 /*
688 * Remove our reservation. The impl() routine avoids setting the
689 * actual property, which would require the (already destroyed) ds.
690 */
691 dsl_dir_set_reservation_sync_impl(dd, 0, tx);
692
693 ASSERT0(dsl_dir_phys(dd)->dd_used_bytes);
694 ASSERT0(dsl_dir_phys(dd)->dd_reserved);
695 for (t = 0; t < DD_USED_NUM; t++)
696 ASSERT0(dsl_dir_phys(dd)->dd_used_breakdown[t]);
697
698 VERIFY0(zap_destroy(mos, dsl_dir_phys(dd)->dd_child_dir_zapobj, tx));
699 VERIFY0(zap_destroy(mos, dsl_dir_phys(dd)->dd_props_zapobj, tx));
700 VERIFY0(dsl_deleg_destroy(mos, dsl_dir_phys(dd)->dd_deleg_zapobj, tx));
701 VERIFY0(zap_remove(mos,
702 dsl_dir_phys(dd->dd_parent)->dd_child_dir_zapobj,
703 dd->dd_myname, tx));
704
705 dsl_dir_rele(dd, FTAG);
706 dmu_object_free_zapified(mos, ddobj, tx);
707 }
708
709 void
710 dsl_destroy_head_sync_impl(dsl_dataset_t *ds, dmu_tx_t *tx)
711 {
712 dsl_pool_t *dp = dmu_tx_pool(tx);
713 objset_t *mos = dp->dp_meta_objset;
714 uint64_t obj, ddobj, prevobj = 0;
715 boolean_t rmorigin;
716
717 ASSERT3U(dsl_dataset_phys(ds)->ds_num_children, <=, 1);
718 ASSERT(ds->ds_prev == NULL ||
719 dsl_dataset_phys(ds->ds_prev)->ds_next_snap_obj != ds->ds_object);
720 ASSERT3U(dsl_dataset_phys(ds)->ds_bp.blk_birth, <=, tx->tx_txg);
721 ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
722
723 /* We need to log before removing it from the namespace. */
724 spa_history_log_internal_ds(ds, "destroy", tx, "");
725
726 rmorigin = (dsl_dir_is_clone(ds->ds_dir) &&
727 DS_IS_DEFER_DESTROY(ds->ds_prev) &&
728 dsl_dataset_phys(ds->ds_prev)->ds_num_children == 2 &&
729 ds->ds_prev->ds_userrefs == 0);
730
731 /* Remove our reservation. */
732 if (ds->ds_reserved != 0) {
733 dsl_dataset_set_refreservation_sync_impl(ds,
734 (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED),
735 0, tx);
736 ASSERT0(ds->ds_reserved);
737 }
738
739 if (ds->ds_large_blocks)
740 spa_feature_decr(dp->dp_spa, SPA_FEATURE_LARGE_BLOCKS, tx);
741
742 dsl_scan_ds_destroyed(ds, tx);
743
744 obj = ds->ds_object;
745
746 if (dsl_dataset_phys(ds)->ds_prev_snap_obj != 0) {
747 /* This is a clone */
748 ASSERT(ds->ds_prev != NULL);
749 ASSERT3U(dsl_dataset_phys(ds->ds_prev)->ds_next_snap_obj, !=,
750 obj);
751 ASSERT0(dsl_dataset_phys(ds)->ds_next_snap_obj);
752
753 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
754 if (dsl_dataset_phys(ds->ds_prev)->ds_next_clones_obj != 0) {
755 dsl_dataset_remove_from_next_clones(ds->ds_prev,
756 obj, tx);
757 }
758
759 ASSERT3U(dsl_dataset_phys(ds->ds_prev)->ds_num_children, >, 1);
760 dsl_dataset_phys(ds->ds_prev)->ds_num_children--;
761 }
762
763 /*
764 * Destroy the deadlist. Unless it's a clone, the
765 * deadlist should be empty. (If it's a clone, it's
766 * safe to ignore the deadlist contents.)
767 */
768 dsl_deadlist_close(&ds->ds_deadlist);
769 dsl_deadlist_free(mos, dsl_dataset_phys(ds)->ds_deadlist_obj, tx);
770 dmu_buf_will_dirty(ds->ds_dbuf, tx);
771 dsl_dataset_phys(ds)->ds_deadlist_obj = 0;
772
773 objset_t *os;
774 VERIFY0(dmu_objset_from_ds(ds, &os));
775
776 if (!spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_ASYNC_DESTROY)) {
777 old_synchronous_dataset_destroy(ds, tx);
778 } else {
779 /*
780 * Move the bptree into the pool's list of trees to
781 * clean up and update space accounting information.
782 */
783 uint64_t used, comp, uncomp;
784
785 zil_destroy_sync(dmu_objset_zil(os), tx);
786
787 if (!spa_feature_is_active(dp->dp_spa,
788 SPA_FEATURE_ASYNC_DESTROY)) {
789 dsl_scan_t *scn = dp->dp_scan;
790 spa_feature_incr(dp->dp_spa, SPA_FEATURE_ASYNC_DESTROY,
791 tx);
792 dp->dp_bptree_obj = bptree_alloc(mos, tx);
793 VERIFY0(zap_add(mos,
794 DMU_POOL_DIRECTORY_OBJECT,
795 DMU_POOL_BPTREE_OBJ, sizeof (uint64_t), 1,
796 &dp->dp_bptree_obj, tx));
797 ASSERT(!scn->scn_async_destroying);
798 scn->scn_async_destroying = B_TRUE;
799 }
800
801 used = dsl_dir_phys(ds->ds_dir)->dd_used_bytes;
802 comp = dsl_dir_phys(ds->ds_dir)->dd_compressed_bytes;
803 uncomp = dsl_dir_phys(ds->ds_dir)->dd_uncompressed_bytes;
804
805 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) ||
806 dsl_dataset_phys(ds)->ds_unique_bytes == used);
807
808 bptree_add(mos, dp->dp_bptree_obj,
809 &dsl_dataset_phys(ds)->ds_bp,
810 dsl_dataset_phys(ds)->ds_prev_snap_txg,
811 used, comp, uncomp, tx);
812 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
813 -used, -comp, -uncomp, tx);
814 dsl_dir_diduse_space(dp->dp_free_dir, DD_USED_HEAD,
815 used, comp, uncomp, tx);
816 }
817
818 if (ds->ds_prev != NULL) {
819 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
820 VERIFY0(zap_remove_int(mos,
821 dsl_dir_phys(ds->ds_prev->ds_dir)->dd_clones,
822 ds->ds_object, tx));
823 }
824 prevobj = ds->ds_prev->ds_object;
825 dsl_dataset_rele(ds->ds_prev, ds);
826 ds->ds_prev = NULL;
827 }
828
829 /*
830 * This must be done after the dsl_traverse(), because it will
831 * re-open the objset.
832 */
833 if (ds->ds_objset) {
834 dmu_objset_evict(ds->ds_objset);
835 ds->ds_objset = NULL;
836 }
837
838 /* Erase the link in the dir */
839 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx);
840 dsl_dir_phys(ds->ds_dir)->dd_head_dataset_obj = 0;
841 ddobj = ds->ds_dir->dd_object;
842 ASSERT(dsl_dataset_phys(ds)->ds_snapnames_zapobj != 0);
843 VERIFY0(zap_destroy(mos,
844 dsl_dataset_phys(ds)->ds_snapnames_zapobj, tx));
845
846 if (ds->ds_bookmarks != 0) {
847 VERIFY0(zap_destroy(mos, ds->ds_bookmarks, tx));
848 spa_feature_decr(dp->dp_spa, SPA_FEATURE_BOOKMARKS, tx);
849 }
850
851 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx);
852
853 ASSERT0(dsl_dataset_phys(ds)->ds_next_clones_obj);
854 ASSERT0(dsl_dataset_phys(ds)->ds_props_obj);
855 ASSERT0(dsl_dataset_phys(ds)->ds_userrefs_obj);
856 dsl_dir_rele(ds->ds_dir, ds);
857 ds->ds_dir = NULL;
858 dmu_object_free_zapified(mos, obj, tx);
859
860 dsl_dir_destroy_sync(ddobj, tx);
861
862 if (rmorigin) {
863 dsl_dataset_t *prev;
864 VERIFY0(dsl_dataset_hold_obj(dp, prevobj, FTAG, &prev));
865 dsl_destroy_snapshot_sync_impl(prev, B_FALSE, tx);
866 dsl_dataset_rele(prev, FTAG);
867 }
868 }
869
870 static void
871 dsl_destroy_head_sync(void *arg, dmu_tx_t *tx)
872 {
873 dsl_destroy_head_arg_t *ddha = arg;
874 dsl_pool_t *dp = dmu_tx_pool(tx);
875 dsl_dataset_t *ds;
876
877 VERIFY0(dsl_dataset_hold(dp, ddha->ddha_name, FTAG, &ds));
878 dsl_destroy_head_sync_impl(ds, tx);
879 dsl_dataset_rele(ds, FTAG);
880 }
881
882 static void
883 dsl_destroy_head_begin_sync(void *arg, dmu_tx_t *tx)
884 {
885 dsl_destroy_head_arg_t *ddha = arg;
886 dsl_pool_t *dp = dmu_tx_pool(tx);
887 dsl_dataset_t *ds;
888
889 VERIFY0(dsl_dataset_hold(dp, ddha->ddha_name, FTAG, &ds));
890
891 /* Mark it as inconsistent on-disk, in case we crash */
892 dmu_buf_will_dirty(ds->ds_dbuf, tx);
893 dsl_dataset_phys(ds)->ds_flags |= DS_FLAG_INCONSISTENT;
894
895 spa_history_log_internal_ds(ds, "destroy begin", tx, "");
896 dsl_dataset_rele(ds, FTAG);
897 }
898
899 int
900 dsl_destroy_head(const char *name)
901 {
902 dsl_destroy_head_arg_t ddha;
903 int error;
904 spa_t *spa;
905 boolean_t isenabled;
906
907 #ifdef _KERNEL
908 zfs_destroy_unmount_origin(name);
909 #endif
910
911 error = spa_open(name, &spa, FTAG);
912 if (error != 0)
913 return (error);
914 isenabled = spa_feature_is_enabled(spa, SPA_FEATURE_ASYNC_DESTROY);
915 spa_close(spa, FTAG);
916
917 ddha.ddha_name = name;
918
919 if (!isenabled) {
920 objset_t *os;
921
922 error = dsl_sync_task(name, dsl_destroy_head_check,
923 dsl_destroy_head_begin_sync, &ddha,
924 0, ZFS_SPACE_CHECK_NONE);
925 if (error != 0)
926 return (error);
927
928 /*
929 * Head deletion is processed in one txg on old pools;
930 * remove the objects from open context so that the txg sync
931 * is not too long.
932 */
933 error = dmu_objset_own(name, DMU_OST_ANY, B_FALSE, FTAG, &os);
934 if (error == 0) {
935 uint64_t prev_snap_txg =
936 dsl_dataset_phys(dmu_objset_ds(os))->
937 ds_prev_snap_txg;
938 for (uint64_t obj = 0; error == 0;
939 error = dmu_object_next(os, &obj, FALSE,
940 prev_snap_txg))
941 (void) dmu_free_long_object(os, obj);
942 /* sync out all frees */
943 txg_wait_synced(dmu_objset_pool(os), 0);
944 dmu_objset_disown(os, FTAG);
945 }
946 }
947
948 return (dsl_sync_task(name, dsl_destroy_head_check,
949 dsl_destroy_head_sync, &ddha, 0, ZFS_SPACE_CHECK_NONE));
950 }
951
952 /*
953 * Note, this function is used as the callback for dmu_objset_find(). We
954 * always return 0 so that we will continue to find and process
955 * inconsistent datasets, even if we encounter an error trying to
956 * process one of them.
957 */
958 /* ARGSUSED */
959 int
960 dsl_destroy_inconsistent(const char *dsname, void *arg)
961 {
962 objset_t *os;
963
964 if (dmu_objset_hold(dsname, FTAG, &os) == 0) {
965 boolean_t inconsistent = DS_IS_INCONSISTENT(dmu_objset_ds(os));
966 dmu_objset_rele(os, FTAG);
967 if (inconsistent)
968 (void) dsl_destroy_head(dsname);
969 }
970 return (0);
971 }