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, 2015 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 * Copyright (c) 2014 Integros [integros.com]
27 */
28
29 #include <sys/zfs_context.h>
30 #include <sys/dsl_userhold.h>
31 #include <sys/dsl_dataset.h>
32 #include <sys/dsl_synctask.h>
33 #include <sys/dmu_tx.h>
34 #include <sys/dsl_pool.h>
35 #include <sys/dsl_dir.h>
36 #include <sys/dmu_traverse.h>
37 #include <sys/dsl_scan.h>
38 #include <sys/dmu_objset.h>
39 #include <sys/zap.h>
40 #include <sys/zfeature.h>
41 #include <sys/zfs_ioctl.h>
42 #include <sys/dsl_deleg.h>
43 #include <sys/dmu_impl.h>
44
45 typedef struct dmu_snapshots_destroy_arg {
46 nvlist_t *dsda_snaps;
47 nvlist_t *dsda_successful_snaps;
48 boolean_t dsda_defer;
49 nvlist_t *dsda_errlist;
50 } dmu_snapshots_destroy_arg_t;
51
52 int
dsl_destroy_snapshot_check_impl(dsl_dataset_t * ds,boolean_t defer)53 dsl_destroy_snapshot_check_impl(dsl_dataset_t *ds, boolean_t defer)
54 {
55 if (!ds->ds_is_snapshot)
56 return (SET_ERROR(EINVAL));
57
58 if (dsl_dataset_long_held(ds))
59 return (SET_ERROR(EBUSY));
60
61 /*
62 * Only allow deferred destroy on pools that support it.
63 * NOTE: deferred destroy is only supported on snapshots.
64 */
65 if (defer) {
66 if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
67 SPA_VERSION_USERREFS)
68 return (SET_ERROR(ENOTSUP));
69 return (0);
70 }
71
72 /*
73 * If this snapshot has an elevated user reference count,
74 * we can't destroy it yet.
75 */
76 if (ds->ds_userrefs > 0)
77 return (SET_ERROR(EBUSY));
78
79 /*
80 * Can't delete a branch point.
81 */
82 if (dsl_dataset_phys(ds)->ds_num_children > 1)
83 return (SET_ERROR(EEXIST));
84
85 return (0);
86 }
87
88 static int
dsl_destroy_snapshot_check(void * arg,dmu_tx_t * tx)89 dsl_destroy_snapshot_check(void *arg, dmu_tx_t *tx)
90 {
91 dmu_snapshots_destroy_arg_t *dsda = arg;
92 dsl_pool_t *dp = dmu_tx_pool(tx);
93 nvpair_t *pair;
94 int error = 0;
95
96 if (!dmu_tx_is_syncing(tx))
97 return (0);
98
99 for (pair = nvlist_next_nvpair(dsda->dsda_snaps, NULL);
100 pair != NULL; pair = nvlist_next_nvpair(dsda->dsda_snaps, pair)) {
101 dsl_dataset_t *ds;
102
103 error = dsl_dataset_hold(dp, nvpair_name(pair),
104 FTAG, &ds);
105
106 /*
107 * If the snapshot does not exist, silently ignore it
108 * (it's "already destroyed").
109 */
110 if (error == ENOENT)
111 continue;
112
113 if (error == 0) {
114 error = dsl_destroy_snapshot_check_impl(ds,
115 dsda->dsda_defer);
116 dsl_dataset_rele(ds, FTAG);
117 }
118
119 if (error == 0) {
120 fnvlist_add_boolean(dsda->dsda_successful_snaps,
121 nvpair_name(pair));
122 } else {
123 fnvlist_add_int32(dsda->dsda_errlist,
124 nvpair_name(pair), error);
125 }
126 }
127
128 pair = nvlist_next_nvpair(dsda->dsda_errlist, NULL);
129 if (pair != NULL)
130 return (fnvpair_value_int32(pair));
131
132 return (0);
133 }
134
135 struct process_old_arg {
136 dsl_dataset_t *ds;
137 dsl_dataset_t *ds_prev;
138 boolean_t after_branch_point;
139 zio_t *pio;
140 uint64_t used, comp, uncomp;
141 };
142
143 static int
process_old_cb(void * arg,const blkptr_t * bp,dmu_tx_t * tx)144 process_old_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
145 {
146 struct process_old_arg *poa = arg;
147 dsl_pool_t *dp = poa->ds->ds_dir->dd_pool;
148
149 ASSERT(!BP_IS_HOLE(bp));
150
151 if (bp->blk_birth <= dsl_dataset_phys(poa->ds)->ds_prev_snap_txg) {
152 dsl_deadlist_insert(&poa->ds->ds_deadlist, bp, tx);
153 if (poa->ds_prev && !poa->after_branch_point &&
154 bp->blk_birth >
155 dsl_dataset_phys(poa->ds_prev)->ds_prev_snap_txg) {
156 dsl_dataset_phys(poa->ds_prev)->ds_unique_bytes +=
157 bp_get_dsize_sync(dp->dp_spa, bp);
158 }
159 } else {
160 poa->used += bp_get_dsize_sync(dp->dp_spa, bp);
161 poa->comp += BP_GET_PSIZE(bp);
162 poa->uncomp += BP_GET_UCSIZE(bp);
163 dsl_free_sync(poa->pio, dp, tx->tx_txg, bp);
164 }
165 return (0);
166 }
167
168 static void
process_old_deadlist(dsl_dataset_t * ds,dsl_dataset_t * ds_prev,dsl_dataset_t * ds_next,boolean_t after_branch_point,dmu_tx_t * tx)169 process_old_deadlist(dsl_dataset_t *ds, dsl_dataset_t *ds_prev,
170 dsl_dataset_t *ds_next, boolean_t after_branch_point, dmu_tx_t *tx)
171 {
172 struct process_old_arg poa = { 0 };
173 dsl_pool_t *dp = ds->ds_dir->dd_pool;
174 objset_t *mos = dp->dp_meta_objset;
175 uint64_t deadlist_obj;
176
177 ASSERT(ds->ds_deadlist.dl_oldfmt);
178 ASSERT(ds_next->ds_deadlist.dl_oldfmt);
179
180 poa.ds = ds;
181 poa.ds_prev = ds_prev;
182 poa.after_branch_point = after_branch_point;
183 poa.pio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
184 VERIFY0(bpobj_iterate(&ds_next->ds_deadlist.dl_bpobj,
185 process_old_cb, &poa, tx));
186 VERIFY0(zio_wait(poa.pio));
187 ASSERT3U(poa.used, ==, dsl_dataset_phys(ds)->ds_unique_bytes);
188
189 /* change snapused */
190 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
191 -poa.used, -poa.comp, -poa.uncomp, tx);
192
193 /* swap next's deadlist to our deadlist */
194 dsl_deadlist_close(&ds->ds_deadlist);
195 dsl_deadlist_close(&ds_next->ds_deadlist);
196 deadlist_obj = dsl_dataset_phys(ds)->ds_deadlist_obj;
197 dsl_dataset_phys(ds)->ds_deadlist_obj =
198 dsl_dataset_phys(ds_next)->ds_deadlist_obj;
199 dsl_dataset_phys(ds_next)->ds_deadlist_obj = deadlist_obj;
200 dsl_deadlist_open(&ds->ds_deadlist, mos,
201 dsl_dataset_phys(ds)->ds_deadlist_obj);
202 dsl_deadlist_open(&ds_next->ds_deadlist, mos,
203 dsl_dataset_phys(ds_next)->ds_deadlist_obj);
204 }
205
206 static void
dsl_dataset_remove_clones_key(dsl_dataset_t * ds,uint64_t mintxg,dmu_tx_t * tx)207 dsl_dataset_remove_clones_key(dsl_dataset_t *ds, uint64_t mintxg, dmu_tx_t *tx)
208 {
209 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
210 zap_cursor_t zc;
211 zap_attribute_t za;
212
213 /*
214 * If it is the old version, dd_clones doesn't exist so we can't
215 * find the clones, but dsl_deadlist_remove_key() is a no-op so it
216 * doesn't matter.
217 */
218 if (dsl_dir_phys(ds->ds_dir)->dd_clones == 0)
219 return;
220
221 for (zap_cursor_init(&zc, mos, dsl_dir_phys(ds->ds_dir)->dd_clones);
222 zap_cursor_retrieve(&zc, &za) == 0;
223 zap_cursor_advance(&zc)) {
224 dsl_dataset_t *clone;
225
226 VERIFY0(dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
227 za.za_first_integer, FTAG, &clone));
228 if (clone->ds_dir->dd_origin_txg > mintxg) {
229 dsl_deadlist_remove_key(&clone->ds_deadlist,
230 mintxg, tx);
231 dsl_dataset_remove_clones_key(clone, mintxg, tx);
232 }
233 dsl_dataset_rele(clone, FTAG);
234 }
235 zap_cursor_fini(&zc);
236 }
237
238 void
dsl_destroy_snapshot_sync_impl(dsl_dataset_t * ds,boolean_t defer,dmu_tx_t * tx)239 dsl_destroy_snapshot_sync_impl(dsl_dataset_t *ds, boolean_t defer, dmu_tx_t *tx)
240 {
241 int err;
242 int after_branch_point = FALSE;
243 dsl_pool_t *dp = ds->ds_dir->dd_pool;
244 objset_t *mos = dp->dp_meta_objset;
245 dsl_dataset_t *ds_prev = NULL;
246 uint64_t obj;
247
248 ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
249 rrw_enter(&ds->ds_bp_rwlock, RW_READER, FTAG);
250 ASSERT3U(dsl_dataset_phys(ds)->ds_bp.blk_birth, <=, tx->tx_txg);
251 rrw_exit(&ds->ds_bp_rwlock, FTAG);
252 ASSERT(refcount_is_zero(&ds->ds_longholds));
253
254 if (defer &&
255 (ds->ds_userrefs > 0 ||
256 dsl_dataset_phys(ds)->ds_num_children > 1)) {
257 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
258 dmu_buf_will_dirty(ds->ds_dbuf, tx);
259 dsl_dataset_phys(ds)->ds_flags |= DS_FLAG_DEFER_DESTROY;
260 spa_history_log_internal_ds(ds, "defer_destroy", tx, "");
261 return;
262 }
263
264 ASSERT3U(dsl_dataset_phys(ds)->ds_num_children, <=, 1);
265
266 /* We need to log before removing it from the namespace. */
267 spa_history_log_internal_ds(ds, "destroy", tx, "");
268
269 dsl_scan_ds_destroyed(ds, tx);
270
271 obj = ds->ds_object;
272
273 for (spa_feature_t f = 0; f < SPA_FEATURES; f++) {
274 if (ds->ds_feature_inuse[f]) {
275 dsl_dataset_deactivate_feature(obj, f, tx);
276 ds->ds_feature_inuse[f] = B_FALSE;
277 }
278 }
279 if (dsl_dataset_phys(ds)->ds_prev_snap_obj != 0) {
280 ASSERT3P(ds->ds_prev, ==, NULL);
281 VERIFY0(dsl_dataset_hold_obj(dp,
282 dsl_dataset_phys(ds)->ds_prev_snap_obj, FTAG, &ds_prev));
283 after_branch_point =
284 (dsl_dataset_phys(ds_prev)->ds_next_snap_obj != obj);
285
286 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx);
287 if (after_branch_point &&
288 dsl_dataset_phys(ds_prev)->ds_next_clones_obj != 0) {
289 dsl_dataset_remove_from_next_clones(ds_prev, obj, tx);
290 if (dsl_dataset_phys(ds)->ds_next_snap_obj != 0) {
291 VERIFY0(zap_add_int(mos,
292 dsl_dataset_phys(ds_prev)->
293 ds_next_clones_obj,
294 dsl_dataset_phys(ds)->ds_next_snap_obj,
295 tx));
296 }
297 }
298 if (!after_branch_point) {
299 dsl_dataset_phys(ds_prev)->ds_next_snap_obj =
300 dsl_dataset_phys(ds)->ds_next_snap_obj;
301 }
302 }
303
304 dsl_dataset_t *ds_next;
305 uint64_t old_unique;
306 uint64_t used = 0, comp = 0, uncomp = 0;
307
308 VERIFY0(dsl_dataset_hold_obj(dp,
309 dsl_dataset_phys(ds)->ds_next_snap_obj, FTAG, &ds_next));
310 ASSERT3U(dsl_dataset_phys(ds_next)->ds_prev_snap_obj, ==, obj);
311
312 old_unique = dsl_dataset_phys(ds_next)->ds_unique_bytes;
313
314 dmu_buf_will_dirty(ds_next->ds_dbuf, tx);
315 dsl_dataset_phys(ds_next)->ds_prev_snap_obj =
316 dsl_dataset_phys(ds)->ds_prev_snap_obj;
317 dsl_dataset_phys(ds_next)->ds_prev_snap_txg =
318 dsl_dataset_phys(ds)->ds_prev_snap_txg;
319 ASSERT3U(dsl_dataset_phys(ds)->ds_prev_snap_txg, ==,
320 ds_prev ? dsl_dataset_phys(ds_prev)->ds_creation_txg : 0);
321
322 if (ds_next->ds_deadlist.dl_oldfmt) {
323 process_old_deadlist(ds, ds_prev, ds_next,
324 after_branch_point, tx);
325 } else {
326 /* Adjust prev's unique space. */
327 if (ds_prev && !after_branch_point) {
328 dsl_deadlist_space_range(&ds_next->ds_deadlist,
329 dsl_dataset_phys(ds_prev)->ds_prev_snap_txg,
330 dsl_dataset_phys(ds)->ds_prev_snap_txg,
331 &used, &comp, &uncomp);
332 dsl_dataset_phys(ds_prev)->ds_unique_bytes += used;
333 }
334
335 /* Adjust snapused. */
336 dsl_deadlist_space_range(&ds_next->ds_deadlist,
337 dsl_dataset_phys(ds)->ds_prev_snap_txg, UINT64_MAX,
338 &used, &comp, &uncomp);
339 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
340 -used, -comp, -uncomp, tx);
341
342 /* Move blocks to be freed to pool's free list. */
343 dsl_deadlist_move_bpobj(&ds_next->ds_deadlist,
344 &dp->dp_free_bpobj, dsl_dataset_phys(ds)->ds_prev_snap_txg,
345 tx);
346 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir,
347 DD_USED_HEAD, used, comp, uncomp, tx);
348
349 /* Merge our deadlist into next's and free it. */
350 dsl_deadlist_merge(&ds_next->ds_deadlist,
351 dsl_dataset_phys(ds)->ds_deadlist_obj, tx);
352 }
353 dsl_deadlist_close(&ds->ds_deadlist);
354 dsl_deadlist_free(mos, dsl_dataset_phys(ds)->ds_deadlist_obj, tx);
355 dmu_buf_will_dirty(ds->ds_dbuf, tx);
356 dsl_dataset_phys(ds)->ds_deadlist_obj = 0;
357
358 /* Collapse range in clone heads */
359 dsl_dataset_remove_clones_key(ds,
360 dsl_dataset_phys(ds)->ds_creation_txg, tx);
361
362 if (ds_next->ds_is_snapshot) {
363 dsl_dataset_t *ds_nextnext;
364
365 /*
366 * Update next's unique to include blocks which
367 * were previously shared by only this snapshot
368 * and it. Those blocks will be born after the
369 * prev snap and before this snap, and will have
370 * died after the next snap and before the one
371 * after that (ie. be on the snap after next's
372 * deadlist).
373 */
374 VERIFY0(dsl_dataset_hold_obj(dp,
375 dsl_dataset_phys(ds_next)->ds_next_snap_obj,
376 FTAG, &ds_nextnext));
377 dsl_deadlist_space_range(&ds_nextnext->ds_deadlist,
378 dsl_dataset_phys(ds)->ds_prev_snap_txg,
379 dsl_dataset_phys(ds)->ds_creation_txg,
380 &used, &comp, &uncomp);
381 dsl_dataset_phys(ds_next)->ds_unique_bytes += used;
382 dsl_dataset_rele(ds_nextnext, FTAG);
383 ASSERT3P(ds_next->ds_prev, ==, NULL);
384
385 /* Collapse range in this head. */
386 dsl_dataset_t *hds;
387 VERIFY0(dsl_dataset_hold_obj(dp,
388 dsl_dir_phys(ds->ds_dir)->dd_head_dataset_obj, FTAG, &hds));
389 dsl_deadlist_remove_key(&hds->ds_deadlist,
390 dsl_dataset_phys(ds)->ds_creation_txg, tx);
391 dsl_dataset_rele(hds, FTAG);
392
393 } else {
394 ASSERT3P(ds_next->ds_prev, ==, ds);
395 dsl_dataset_rele(ds_next->ds_prev, ds_next);
396 ds_next->ds_prev = NULL;
397 if (ds_prev) {
398 VERIFY0(dsl_dataset_hold_obj(dp,
399 dsl_dataset_phys(ds)->ds_prev_snap_obj,
400 ds_next, &ds_next->ds_prev));
401 }
402
403 dsl_dataset_recalc_head_uniq(ds_next);
404
405 /*
406 * Reduce the amount of our unconsumed refreservation
407 * being charged to our parent by the amount of
408 * new unique data we have gained.
409 */
410 if (old_unique < ds_next->ds_reserved) {
411 int64_t mrsdelta;
412 uint64_t new_unique =
413 dsl_dataset_phys(ds_next)->ds_unique_bytes;
414
415 ASSERT(old_unique <= new_unique);
416 mrsdelta = MIN(new_unique - old_unique,
417 ds_next->ds_reserved - old_unique);
418 dsl_dir_diduse_space(ds->ds_dir,
419 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx);
420 }
421 }
422 dsl_dataset_rele(ds_next, FTAG);
423
424 /*
425 * This must be done after the dsl_traverse(), because it will
426 * re-open the objset.
427 */
428 if (ds->ds_objset) {
429 dmu_objset_evict(ds->ds_objset);
430 ds->ds_objset = NULL;
431 }
432
433 /* remove from snapshot namespace */
434 dsl_dataset_t *ds_head;
435 ASSERT(dsl_dataset_phys(ds)->ds_snapnames_zapobj == 0);
436 VERIFY0(dsl_dataset_hold_obj(dp,
437 dsl_dir_phys(ds->ds_dir)->dd_head_dataset_obj, FTAG, &ds_head));
438 VERIFY0(dsl_dataset_get_snapname(ds));
439 #ifdef ZFS_DEBUG
440 {
441 uint64_t val;
442
443 err = dsl_dataset_snap_lookup(ds_head,
444 ds->ds_snapname, &val);
445 ASSERT0(err);
446 ASSERT3U(val, ==, obj);
447 }
448 #endif
449 VERIFY0(dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx, B_TRUE));
450 dsl_dataset_rele(ds_head, FTAG);
451
452 if (ds_prev != NULL)
453 dsl_dataset_rele(ds_prev, FTAG);
454
455 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx);
456
457 if (dsl_dataset_phys(ds)->ds_next_clones_obj != 0) {
458 uint64_t count;
459 ASSERT0(zap_count(mos,
460 dsl_dataset_phys(ds)->ds_next_clones_obj, &count) &&
461 count == 0);
462 VERIFY0(dmu_object_free(mos,
463 dsl_dataset_phys(ds)->ds_next_clones_obj, tx));
464 }
465 if (dsl_dataset_phys(ds)->ds_props_obj != 0)
466 VERIFY0(zap_destroy(mos, dsl_dataset_phys(ds)->ds_props_obj,
467 tx));
468 if (dsl_dataset_phys(ds)->ds_userrefs_obj != 0)
469 VERIFY0(zap_destroy(mos, dsl_dataset_phys(ds)->ds_userrefs_obj,
470 tx));
471 dsl_dir_rele(ds->ds_dir, ds);
472 ds->ds_dir = NULL;
473 dmu_object_free_zapified(mos, obj, tx);
474 }
475
476 static void
dsl_destroy_snapshot_sync(void * arg,dmu_tx_t * tx)477 dsl_destroy_snapshot_sync(void *arg, dmu_tx_t *tx)
478 {
479 dmu_snapshots_destroy_arg_t *dsda = arg;
480 dsl_pool_t *dp = dmu_tx_pool(tx);
481 nvpair_t *pair;
482
483 for (pair = nvlist_next_nvpair(dsda->dsda_successful_snaps, NULL);
484 pair != NULL;
485 pair = nvlist_next_nvpair(dsda->dsda_successful_snaps, pair)) {
486 dsl_dataset_t *ds;
487
488 VERIFY0(dsl_dataset_hold(dp, nvpair_name(pair), FTAG, &ds));
489
490 dsl_destroy_snapshot_sync_impl(ds, dsda->dsda_defer, tx);
491 dsl_dataset_rele(ds, FTAG);
492 }
493 }
494
495 /*
496 * The semantics of this function are described in the comment above
497 * lzc_destroy_snaps(). To summarize:
498 *
499 * The snapshots must all be in the same pool.
500 *
501 * Snapshots that don't exist will be silently ignored (considered to be
502 * "already deleted").
503 *
504 * On success, all snaps will be destroyed and this will return 0.
505 * On failure, no snaps will be destroyed, the errlist will be filled in,
506 * and this will return an errno.
507 */
508 int
dsl_destroy_snapshots_nvl(nvlist_t * snaps,boolean_t defer,nvlist_t * errlist)509 dsl_destroy_snapshots_nvl(nvlist_t *snaps, boolean_t defer,
510 nvlist_t *errlist)
511 {
512 dmu_snapshots_destroy_arg_t dsda;
513 int error;
514 nvpair_t *pair;
515
516 pair = nvlist_next_nvpair(snaps, NULL);
517 if (pair == NULL)
518 return (0);
519
520 dsda.dsda_snaps = snaps;
521 dsda.dsda_successful_snaps = fnvlist_alloc();
522 dsda.dsda_defer = defer;
523 dsda.dsda_errlist = errlist;
524
525 error = dsl_sync_task(nvpair_name(pair),
526 dsl_destroy_snapshot_check, dsl_destroy_snapshot_sync,
527 &dsda, 0, ZFS_SPACE_CHECK_NONE);
528 fnvlist_free(dsda.dsda_successful_snaps);
529
530 return (error);
531 }
532
533 int
dsl_destroy_snapshot(const char * name,boolean_t defer)534 dsl_destroy_snapshot(const char *name, boolean_t defer)
535 {
536 int error;
537 nvlist_t *nvl = fnvlist_alloc();
538 nvlist_t *errlist = fnvlist_alloc();
539
540 fnvlist_add_boolean(nvl, name);
541 error = dsl_destroy_snapshots_nvl(nvl, defer, errlist);
542 fnvlist_free(errlist);
543 fnvlist_free(nvl);
544 return (error);
545 }
546
547 struct killarg {
548 dsl_dataset_t *ds;
549 dmu_tx_t *tx;
550 };
551
552 /* ARGSUSED */
553 static int
kill_blkptr(spa_t * spa,zilog_t * zilog,const blkptr_t * bp,const zbookmark_phys_t * zb,const dnode_phys_t * dnp,void * arg)554 kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
555 const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
556 {
557 struct killarg *ka = arg;
558 dmu_tx_t *tx = ka->tx;
559
560 if (bp == NULL || BP_IS_HOLE(bp) || BP_IS_EMBEDDED(bp))
561 return (0);
562
563 if (zb->zb_level == ZB_ZIL_LEVEL) {
564 ASSERT(zilog != NULL);
565 /*
566 * It's a block in the intent log. It has no
567 * accounting, so just free it.
568 */
569 dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp);
570 } else {
571 ASSERT(zilog == NULL);
572 ASSERT3U(bp->blk_birth, >,
573 dsl_dataset_phys(ka->ds)->ds_prev_snap_txg);
574 (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE);
575 }
576
577 return (0);
578 }
579
580 static void
old_synchronous_dataset_destroy(dsl_dataset_t * ds,dmu_tx_t * tx)581 old_synchronous_dataset_destroy(dsl_dataset_t *ds, dmu_tx_t *tx)
582 {
583 struct killarg ka;
584
585 /*
586 * Free everything that we point to (that's born after
587 * the previous snapshot, if we are a clone)
588 *
589 * NB: this should be very quick, because we already
590 * freed all the objects in open context.
591 */
592 ka.ds = ds;
593 ka.tx = tx;
594 VERIFY0(traverse_dataset(ds,
595 dsl_dataset_phys(ds)->ds_prev_snap_txg, TRAVERSE_POST,
596 kill_blkptr, &ka));
597 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) ||
598 dsl_dataset_phys(ds)->ds_unique_bytes == 0);
599 }
600
601 typedef struct dsl_destroy_head_arg {
602 const char *ddha_name;
603 } dsl_destroy_head_arg_t;
604
605 int
dsl_destroy_head_check_impl(dsl_dataset_t * ds,int expected_holds)606 dsl_destroy_head_check_impl(dsl_dataset_t *ds, int expected_holds)
607 {
608 int error;
609 uint64_t count;
610 objset_t *mos;
611
612 ASSERT(!ds->ds_is_snapshot);
613 if (ds->ds_is_snapshot)
614 return (SET_ERROR(EINVAL));
615
616 if (refcount_count(&ds->ds_longholds) != expected_holds)
617 return (SET_ERROR(EBUSY));
618
619 mos = ds->ds_dir->dd_pool->dp_meta_objset;
620
621 /*
622 * Can't delete a head dataset if there are snapshots of it.
623 * (Except if the only snapshots are from the branch we cloned
624 * from.)
625 */
626 if (ds->ds_prev != NULL &&
627 dsl_dataset_phys(ds->ds_prev)->ds_next_snap_obj == ds->ds_object)
628 return (SET_ERROR(EBUSY));
629
630 /*
631 * Can't delete if there are children of this fs.
632 */
633 error = zap_count(mos,
634 dsl_dir_phys(ds->ds_dir)->dd_child_dir_zapobj, &count);
635 if (error != 0)
636 return (error);
637 if (count != 0)
638 return (SET_ERROR(EEXIST));
639
640 if (dsl_dir_is_clone(ds->ds_dir) && DS_IS_DEFER_DESTROY(ds->ds_prev) &&
641 dsl_dataset_phys(ds->ds_prev)->ds_num_children == 2 &&
642 ds->ds_prev->ds_userrefs == 0) {
643 /* We need to remove the origin snapshot as well. */
644 if (!refcount_is_zero(&ds->ds_prev->ds_longholds))
645 return (SET_ERROR(EBUSY));
646 }
647 return (0);
648 }
649
650 static int
dsl_destroy_head_check(void * arg,dmu_tx_t * tx)651 dsl_destroy_head_check(void *arg, dmu_tx_t *tx)
652 {
653 dsl_destroy_head_arg_t *ddha = arg;
654 dsl_pool_t *dp = dmu_tx_pool(tx);
655 dsl_dataset_t *ds;
656 int error;
657
658 error = dsl_dataset_hold(dp, ddha->ddha_name, FTAG, &ds);
659 if (error != 0)
660 return (error);
661
662 error = dsl_destroy_head_check_impl(ds, 0);
663 dsl_dataset_rele(ds, FTAG);
664 return (error);
665 }
666
667 static void
dsl_dir_destroy_sync(uint64_t ddobj,dmu_tx_t * tx)668 dsl_dir_destroy_sync(uint64_t ddobj, dmu_tx_t *tx)
669 {
670 dsl_dir_t *dd;
671 dsl_pool_t *dp = dmu_tx_pool(tx);
672 objset_t *mos = dp->dp_meta_objset;
673 dd_used_t t;
674
675 ASSERT(RRW_WRITE_HELD(&dmu_tx_pool(tx)->dp_config_rwlock));
676
677 VERIFY0(dsl_dir_hold_obj(dp, ddobj, NULL, FTAG, &dd));
678
679 ASSERT0(dsl_dir_phys(dd)->dd_head_dataset_obj);
680
681 /*
682 * Decrement the filesystem count for all parent filesystems.
683 *
684 * When we receive an incremental stream into a filesystem that already
685 * exists, a temporary clone is created. We never count this temporary
686 * clone, whose name begins with a '%'.
687 */
688 if (dd->dd_myname[0] != '%' && dd->dd_parent != NULL)
689 dsl_fs_ss_count_adjust(dd->dd_parent, -1,
690 DD_FIELD_FILESYSTEM_COUNT, tx);
691
692 /*
693 * Remove our reservation. The impl() routine avoids setting the
694 * actual property, which would require the (already destroyed) ds.
695 */
696 dsl_dir_set_reservation_sync_impl(dd, 0, tx);
697
698 ASSERT0(dsl_dir_phys(dd)->dd_used_bytes);
699 ASSERT0(dsl_dir_phys(dd)->dd_reserved);
700 for (t = 0; t < DD_USED_NUM; t++)
701 ASSERT0(dsl_dir_phys(dd)->dd_used_breakdown[t]);
702
703 VERIFY0(zap_destroy(mos, dsl_dir_phys(dd)->dd_child_dir_zapobj, tx));
704 VERIFY0(zap_destroy(mos, dsl_dir_phys(dd)->dd_props_zapobj, tx));
705 VERIFY0(dsl_deleg_destroy(mos, dsl_dir_phys(dd)->dd_deleg_zapobj, tx));
706 VERIFY0(zap_remove(mos,
707 dsl_dir_phys(dd->dd_parent)->dd_child_dir_zapobj,
708 dd->dd_myname, tx));
709
710 dsl_dir_rele(dd, FTAG);
711 dmu_object_free_zapified(mos, ddobj, tx);
712 }
713
714 void
dsl_destroy_head_sync_impl(dsl_dataset_t * ds,dmu_tx_t * tx)715 dsl_destroy_head_sync_impl(dsl_dataset_t *ds, dmu_tx_t *tx)
716 {
717 dsl_pool_t *dp = dmu_tx_pool(tx);
718 objset_t *mos = dp->dp_meta_objset;
719 uint64_t obj, ddobj, prevobj = 0;
720 boolean_t rmorigin;
721
722 ASSERT3U(dsl_dataset_phys(ds)->ds_num_children, <=, 1);
723 ASSERT(ds->ds_prev == NULL ||
724 dsl_dataset_phys(ds->ds_prev)->ds_next_snap_obj != ds->ds_object);
725 rrw_enter(&ds->ds_bp_rwlock, RW_READER, FTAG);
726 ASSERT3U(dsl_dataset_phys(ds)->ds_bp.blk_birth, <=, tx->tx_txg);
727 rrw_exit(&ds->ds_bp_rwlock, FTAG);
728 ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
729
730 /* We need to log before removing it from the namespace. */
731 spa_history_log_internal_ds(ds, "destroy", tx, "");
732
733 rmorigin = (dsl_dir_is_clone(ds->ds_dir) &&
734 DS_IS_DEFER_DESTROY(ds->ds_prev) &&
735 dsl_dataset_phys(ds->ds_prev)->ds_num_children == 2 &&
736 ds->ds_prev->ds_userrefs == 0);
737
738 /* Remove our reservation. */
739 if (ds->ds_reserved != 0) {
740 dsl_dataset_set_refreservation_sync_impl(ds,
741 (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED),
742 0, tx);
743 ASSERT0(ds->ds_reserved);
744 }
745
746 obj = ds->ds_object;
747
748 for (spa_feature_t f = 0; f < SPA_FEATURES; f++) {
749 if (ds->ds_feature_inuse[f]) {
750 dsl_dataset_deactivate_feature(obj, f, tx);
751 ds->ds_feature_inuse[f] = B_FALSE;
752 }
753 }
754
755 dsl_scan_ds_destroyed(ds, tx);
756
757 if (dsl_dataset_phys(ds)->ds_prev_snap_obj != 0) {
758 /* This is a clone */
759 ASSERT(ds->ds_prev != NULL);
760 ASSERT3U(dsl_dataset_phys(ds->ds_prev)->ds_next_snap_obj, !=,
761 obj);
762 ASSERT0(dsl_dataset_phys(ds)->ds_next_snap_obj);
763
764 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
765 if (dsl_dataset_phys(ds->ds_prev)->ds_next_clones_obj != 0) {
766 dsl_dataset_remove_from_next_clones(ds->ds_prev,
767 obj, tx);
768 }
769
770 ASSERT3U(dsl_dataset_phys(ds->ds_prev)->ds_num_children, >, 1);
771 dsl_dataset_phys(ds->ds_prev)->ds_num_children--;
772 }
773
774 /*
775 * Destroy the deadlist. Unless it's a clone, the
776 * deadlist should be empty. (If it's a clone, it's
777 * safe to ignore the deadlist contents.)
778 */
779 dsl_deadlist_close(&ds->ds_deadlist);
780 dsl_deadlist_free(mos, dsl_dataset_phys(ds)->ds_deadlist_obj, tx);
781 dmu_buf_will_dirty(ds->ds_dbuf, tx);
782 dsl_dataset_phys(ds)->ds_deadlist_obj = 0;
783
784 objset_t *os;
785 VERIFY0(dmu_objset_from_ds(ds, &os));
786
787 if (!spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_ASYNC_DESTROY)) {
788 old_synchronous_dataset_destroy(ds, tx);
789 } else {
790 /*
791 * Move the bptree into the pool's list of trees to
792 * clean up and update space accounting information.
793 */
794 uint64_t used, comp, uncomp;
795
796 zil_destroy_sync(dmu_objset_zil(os), tx);
797
798 if (!spa_feature_is_active(dp->dp_spa,
799 SPA_FEATURE_ASYNC_DESTROY)) {
800 dsl_scan_t *scn = dp->dp_scan;
801 spa_feature_incr(dp->dp_spa, SPA_FEATURE_ASYNC_DESTROY,
802 tx);
803 dp->dp_bptree_obj = bptree_alloc(mos, tx);
804 VERIFY0(zap_add(mos,
805 DMU_POOL_DIRECTORY_OBJECT,
806 DMU_POOL_BPTREE_OBJ, sizeof (uint64_t), 1,
807 &dp->dp_bptree_obj, tx));
808 ASSERT(!scn->scn_async_destroying);
809 scn->scn_async_destroying = B_TRUE;
810 }
811
812 used = dsl_dir_phys(ds->ds_dir)->dd_used_bytes;
813 comp = dsl_dir_phys(ds->ds_dir)->dd_compressed_bytes;
814 uncomp = dsl_dir_phys(ds->ds_dir)->dd_uncompressed_bytes;
815
816 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) ||
817 dsl_dataset_phys(ds)->ds_unique_bytes == used);
818
819 rrw_enter(&ds->ds_bp_rwlock, RW_READER, FTAG);
820 bptree_add(mos, dp->dp_bptree_obj,
821 &dsl_dataset_phys(ds)->ds_bp,
822 dsl_dataset_phys(ds)->ds_prev_snap_txg,
823 used, comp, uncomp, tx);
824 rrw_exit(&ds->ds_bp_rwlock, FTAG);
825 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
826 -used, -comp, -uncomp, tx);
827 dsl_dir_diduse_space(dp->dp_free_dir, DD_USED_HEAD,
828 used, comp, uncomp, tx);
829 }
830
831 if (ds->ds_prev != NULL) {
832 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
833 VERIFY0(zap_remove_int(mos,
834 dsl_dir_phys(ds->ds_prev->ds_dir)->dd_clones,
835 ds->ds_object, tx));
836 }
837 prevobj = ds->ds_prev->ds_object;
838 dsl_dataset_rele(ds->ds_prev, ds);
839 ds->ds_prev = NULL;
840 }
841
842 /*
843 * This must be done after the dsl_traverse(), because it will
844 * re-open the objset.
845 */
846 if (ds->ds_objset) {
847 dmu_objset_evict(ds->ds_objset);
848 ds->ds_objset = NULL;
849 }
850
851 /* Erase the link in the dir */
852 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx);
853 dsl_dir_phys(ds->ds_dir)->dd_head_dataset_obj = 0;
854 ddobj = ds->ds_dir->dd_object;
855 ASSERT(dsl_dataset_phys(ds)->ds_snapnames_zapobj != 0);
856 VERIFY0(zap_destroy(mos,
857 dsl_dataset_phys(ds)->ds_snapnames_zapobj, tx));
858
859 if (ds->ds_bookmarks != 0) {
860 VERIFY0(zap_destroy(mos, ds->ds_bookmarks, tx));
861 spa_feature_decr(dp->dp_spa, SPA_FEATURE_BOOKMARKS, tx);
862 }
863
864 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx);
865
866 ASSERT0(dsl_dataset_phys(ds)->ds_next_clones_obj);
867 ASSERT0(dsl_dataset_phys(ds)->ds_props_obj);
868 ASSERT0(dsl_dataset_phys(ds)->ds_userrefs_obj);
869 dsl_dir_rele(ds->ds_dir, ds);
870 ds->ds_dir = NULL;
871 dmu_object_free_zapified(mos, obj, tx);
872
873 dsl_dir_destroy_sync(ddobj, tx);
874
875 if (rmorigin) {
876 dsl_dataset_t *prev;
877 VERIFY0(dsl_dataset_hold_obj(dp, prevobj, FTAG, &prev));
878 dsl_destroy_snapshot_sync_impl(prev, B_FALSE, tx);
879 dsl_dataset_rele(prev, FTAG);
880 }
881 }
882
883 static void
dsl_destroy_head_sync(void * arg,dmu_tx_t * tx)884 dsl_destroy_head_sync(void *arg, dmu_tx_t *tx)
885 {
886 dsl_destroy_head_arg_t *ddha = arg;
887 dsl_pool_t *dp = dmu_tx_pool(tx);
888 dsl_dataset_t *ds;
889
890 VERIFY0(dsl_dataset_hold(dp, ddha->ddha_name, FTAG, &ds));
891 dsl_destroy_head_sync_impl(ds, tx);
892 dsl_dataset_rele(ds, FTAG);
893 }
894
895 static void
dsl_destroy_head_begin_sync(void * arg,dmu_tx_t * tx)896 dsl_destroy_head_begin_sync(void *arg, dmu_tx_t *tx)
897 {
898 dsl_destroy_head_arg_t *ddha = arg;
899 dsl_pool_t *dp = dmu_tx_pool(tx);
900 dsl_dataset_t *ds;
901
902 VERIFY0(dsl_dataset_hold(dp, ddha->ddha_name, FTAG, &ds));
903
904 /* Mark it as inconsistent on-disk, in case we crash */
905 dmu_buf_will_dirty(ds->ds_dbuf, tx);
906 dsl_dataset_phys(ds)->ds_flags |= DS_FLAG_INCONSISTENT;
907
908 spa_history_log_internal_ds(ds, "destroy begin", tx, "");
909 dsl_dataset_rele(ds, FTAG);
910 }
911
912 int
dsl_destroy_head(const char * name)913 dsl_destroy_head(const char *name)
914 {
915 dsl_destroy_head_arg_t ddha;
916 int error;
917 spa_t *spa;
918 boolean_t isenabled;
919
920 #ifdef _KERNEL
921 zfs_destroy_unmount_origin(name);
922 #endif
923
924 error = spa_open(name, &spa, FTAG);
925 if (error != 0)
926 return (error);
927 isenabled = spa_feature_is_enabled(spa, SPA_FEATURE_ASYNC_DESTROY);
928 spa_close(spa, FTAG);
929
930 ddha.ddha_name = name;
931
932 if (!isenabled) {
933 objset_t *os;
934
935 error = dsl_sync_task(name, dsl_destroy_head_check,
936 dsl_destroy_head_begin_sync, &ddha,
937 0, ZFS_SPACE_CHECK_NONE);
938 if (error != 0)
939 return (error);
940
941 /*
942 * Head deletion is processed in one txg on old pools;
943 * remove the objects from open context so that the txg sync
944 * is not too long.
945 */
946 error = dmu_objset_own(name, DMU_OST_ANY, B_FALSE, FTAG, &os);
947 if (error == 0) {
948 uint64_t prev_snap_txg =
949 dsl_dataset_phys(dmu_objset_ds(os))->
950 ds_prev_snap_txg;
951 for (uint64_t obj = 0; error == 0;
952 error = dmu_object_next(os, &obj, FALSE,
953 prev_snap_txg))
954 (void) dmu_free_long_object(os, obj);
955 /* sync out all frees */
956 txg_wait_synced(dmu_objset_pool(os), 0);
957 dmu_objset_disown(os, FTAG);
958 }
959 }
960
961 return (dsl_sync_task(name, dsl_destroy_head_check,
962 dsl_destroy_head_sync, &ddha, 0, ZFS_SPACE_CHECK_NONE));
963 }
964
965 /*
966 * Note, this function is used as the callback for dmu_objset_find(). We
967 * always return 0 so that we will continue to find and process
968 * inconsistent datasets, even if we encounter an error trying to
969 * process one of them.
970 */
971 /* ARGSUSED */
972 int
dsl_destroy_inconsistent(const char * dsname,void * arg)973 dsl_destroy_inconsistent(const char *dsname, void *arg)
974 {
975 objset_t *os;
976
977 if (dmu_objset_hold(dsname, FTAG, &os) == 0) {
978 boolean_t need_destroy = DS_IS_INCONSISTENT(dmu_objset_ds(os));
979
980 /*
981 * If the dataset is inconsistent because a resumable receive
982 * has failed, then do not destroy it.
983 */
984 if (dsl_dataset_has_resume_receive_state(dmu_objset_ds(os)))
985 need_destroy = B_FALSE;
986
987 dmu_objset_rele(os, FTAG);
988 if (need_destroy)
989 (void) dsl_destroy_head(dsname);
990 }
991 return (0);
992 }
993