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, 2017 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/dsl_destroy.h>
34 #include <sys/dmu_tx.h>
35 #include <sys/dsl_pool.h>
36 #include <sys/dsl_dir.h>
37 #include <sys/dmu_traverse.h>
38 #include <sys/dsl_scan.h>
39 #include <sys/dmu_objset.h>
40 #include <sys/zap.h>
41 #include <sys/zfeature.h>
42 #include <sys/zfs_ioctl.h>
43 #include <sys/dsl_deleg.h>
44 #include <sys/dmu_impl.h>
45 #include <sys/zcp.h>
46
47 int
dsl_destroy_snapshot_check_impl(dsl_dataset_t * ds,boolean_t defer)48 dsl_destroy_snapshot_check_impl(dsl_dataset_t *ds, boolean_t defer)
49 {
50 if (!ds->ds_is_snapshot)
51 return (SET_ERROR(EINVAL));
52
53 if (dsl_dataset_long_held(ds))
54 return (SET_ERROR(EBUSY));
55
56 /*
57 * Only allow deferred destroy on pools that support it.
58 * NOTE: deferred destroy is only supported on snapshots.
59 */
60 if (defer) {
61 if (spa_version(ds->ds_dir->dd_pool->dp_spa) <
62 SPA_VERSION_USERREFS)
63 return (SET_ERROR(ENOTSUP));
64 return (0);
65 }
66
67 /*
68 * If this snapshot has an elevated user reference count,
69 * we can't destroy it yet.
70 */
71 if (ds->ds_userrefs > 0)
72 return (SET_ERROR(EBUSY));
73
74 /*
75 * Can't delete a branch point.
76 */
77 if (dsl_dataset_phys(ds)->ds_num_children > 1)
78 return (SET_ERROR(EEXIST));
79
80 return (0);
81 }
82
83 int
dsl_destroy_snapshot_check(void * arg,dmu_tx_t * tx)84 dsl_destroy_snapshot_check(void *arg, dmu_tx_t *tx)
85 {
86 dsl_destroy_snapshot_arg_t *ddsa = arg;
87 const char *dsname = ddsa->ddsa_name;
88 boolean_t defer = ddsa->ddsa_defer;
89
90 dsl_pool_t *dp = dmu_tx_pool(tx);
91 int error = 0;
92 dsl_dataset_t *ds;
93
94 error = dsl_dataset_hold(dp, dsname, FTAG, &ds);
95
96 /*
97 * If the snapshot does not exist, silently ignore it, and
98 * dsl_destroy_snapshot_sync() will be a no-op
99 * (it's "already destroyed").
100 */
101 if (error == ENOENT)
102 return (0);
103
104 if (error == 0) {
105 error = dsl_destroy_snapshot_check_impl(ds, defer);
106 dsl_dataset_rele(ds, FTAG);
107 }
108
109 return (error);
110 }
111
112 struct process_old_arg {
113 dsl_dataset_t *ds;
114 dsl_dataset_t *ds_prev;
115 boolean_t after_branch_point;
116 zio_t *pio;
117 uint64_t used, comp, uncomp;
118 };
119
120 static int
process_old_cb(void * arg,const blkptr_t * bp,dmu_tx_t * tx)121 process_old_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx)
122 {
123 struct process_old_arg *poa = arg;
124 dsl_pool_t *dp = poa->ds->ds_dir->dd_pool;
125
126 ASSERT(!BP_IS_HOLE(bp));
127
128 if (bp->blk_birth <= dsl_dataset_phys(poa->ds)->ds_prev_snap_txg) {
129 dsl_deadlist_insert(&poa->ds->ds_deadlist, bp, tx);
130 if (poa->ds_prev && !poa->after_branch_point &&
131 bp->blk_birth >
132 dsl_dataset_phys(poa->ds_prev)->ds_prev_snap_txg) {
133 dsl_dataset_phys(poa->ds_prev)->ds_unique_bytes +=
134 bp_get_dsize_sync(dp->dp_spa, bp);
135 }
136 } else {
137 poa->used += bp_get_dsize_sync(dp->dp_spa, bp);
138 poa->comp += BP_GET_PSIZE(bp);
139 poa->uncomp += BP_GET_UCSIZE(bp);
140 dsl_free_sync(poa->pio, dp, tx->tx_txg, bp);
141 }
142 return (0);
143 }
144
145 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)146 process_old_deadlist(dsl_dataset_t *ds, dsl_dataset_t *ds_prev,
147 dsl_dataset_t *ds_next, boolean_t after_branch_point, dmu_tx_t *tx)
148 {
149 struct process_old_arg poa = { 0 };
150 dsl_pool_t *dp = ds->ds_dir->dd_pool;
151 objset_t *mos = dp->dp_meta_objset;
152 uint64_t deadlist_obj;
153
154 ASSERT(ds->ds_deadlist.dl_oldfmt);
155 ASSERT(ds_next->ds_deadlist.dl_oldfmt);
156
157 poa.ds = ds;
158 poa.ds_prev = ds_prev;
159 poa.after_branch_point = after_branch_point;
160 poa.pio = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_MUSTSUCCEED);
161 VERIFY0(bpobj_iterate(&ds_next->ds_deadlist.dl_bpobj,
162 process_old_cb, &poa, tx));
163 VERIFY0(zio_wait(poa.pio));
164 ASSERT3U(poa.used, ==, dsl_dataset_phys(ds)->ds_unique_bytes);
165
166 /* change snapused */
167 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
168 -poa.used, -poa.comp, -poa.uncomp, tx);
169
170 /* swap next's deadlist to our deadlist */
171 dsl_deadlist_close(&ds->ds_deadlist);
172 dsl_deadlist_close(&ds_next->ds_deadlist);
173 deadlist_obj = dsl_dataset_phys(ds)->ds_deadlist_obj;
174 dsl_dataset_phys(ds)->ds_deadlist_obj =
175 dsl_dataset_phys(ds_next)->ds_deadlist_obj;
176 dsl_dataset_phys(ds_next)->ds_deadlist_obj = deadlist_obj;
177 dsl_deadlist_open(&ds->ds_deadlist, mos,
178 dsl_dataset_phys(ds)->ds_deadlist_obj);
179 dsl_deadlist_open(&ds_next->ds_deadlist, mos,
180 dsl_dataset_phys(ds_next)->ds_deadlist_obj);
181 }
182
183 static void
dsl_dataset_remove_clones_key(dsl_dataset_t * ds,uint64_t mintxg,dmu_tx_t * tx)184 dsl_dataset_remove_clones_key(dsl_dataset_t *ds, uint64_t mintxg, dmu_tx_t *tx)
185 {
186 objset_t *mos = ds->ds_dir->dd_pool->dp_meta_objset;
187 zap_cursor_t zc;
188 zap_attribute_t za;
189
190 /*
191 * If it is the old version, dd_clones doesn't exist so we can't
192 * find the clones, but dsl_deadlist_remove_key() is a no-op so it
193 * doesn't matter.
194 */
195 if (dsl_dir_phys(ds->ds_dir)->dd_clones == 0)
196 return;
197
198 for (zap_cursor_init(&zc, mos, dsl_dir_phys(ds->ds_dir)->dd_clones);
199 zap_cursor_retrieve(&zc, &za) == 0;
200 zap_cursor_advance(&zc)) {
201 dsl_dataset_t *clone;
202
203 VERIFY0(dsl_dataset_hold_obj(ds->ds_dir->dd_pool,
204 za.za_first_integer, FTAG, &clone));
205 if (clone->ds_dir->dd_origin_txg > mintxg) {
206 dsl_deadlist_remove_key(&clone->ds_deadlist,
207 mintxg, tx);
208 if (dsl_dataset_remap_deadlist_exists(clone)) {
209 dsl_deadlist_remove_key(
210 &clone->ds_remap_deadlist, mintxg, tx);
211 }
212 dsl_dataset_remove_clones_key(clone, mintxg, tx);
213 }
214 dsl_dataset_rele(clone, FTAG);
215 }
216 zap_cursor_fini(&zc);
217 }
218
219 static void
dsl_destroy_snapshot_handle_remaps(dsl_dataset_t * ds,dsl_dataset_t * ds_next,dmu_tx_t * tx)220 dsl_destroy_snapshot_handle_remaps(dsl_dataset_t *ds, dsl_dataset_t *ds_next,
221 dmu_tx_t *tx)
222 {
223 dsl_pool_t *dp = ds->ds_dir->dd_pool;
224
225 /* Move blocks to be obsoleted to pool's obsolete list. */
226 if (dsl_dataset_remap_deadlist_exists(ds_next)) {
227 if (!bpobj_is_open(&dp->dp_obsolete_bpobj))
228 dsl_pool_create_obsolete_bpobj(dp, tx);
229
230 dsl_deadlist_move_bpobj(&ds_next->ds_remap_deadlist,
231 &dp->dp_obsolete_bpobj,
232 dsl_dataset_phys(ds)->ds_prev_snap_txg, tx);
233 }
234
235 /* Merge our deadlist into next's and free it. */
236 if (dsl_dataset_remap_deadlist_exists(ds)) {
237 uint64_t remap_deadlist_object =
238 dsl_dataset_get_remap_deadlist_object(ds);
239 ASSERT(remap_deadlist_object != 0);
240
241 mutex_enter(&ds_next->ds_remap_deadlist_lock);
242 if (!dsl_dataset_remap_deadlist_exists(ds_next))
243 dsl_dataset_create_remap_deadlist(ds_next, tx);
244 mutex_exit(&ds_next->ds_remap_deadlist_lock);
245
246 dsl_deadlist_merge(&ds_next->ds_remap_deadlist,
247 remap_deadlist_object, tx);
248 dsl_dataset_destroy_remap_deadlist(ds, tx);
249 }
250 }
251
252 void
dsl_destroy_snapshot_sync_impl(dsl_dataset_t * ds,boolean_t defer,dmu_tx_t * tx)253 dsl_destroy_snapshot_sync_impl(dsl_dataset_t *ds, boolean_t defer, dmu_tx_t *tx)
254 {
255 int err;
256 int after_branch_point = FALSE;
257 dsl_pool_t *dp = ds->ds_dir->dd_pool;
258 objset_t *mos = dp->dp_meta_objset;
259 dsl_dataset_t *ds_prev = NULL;
260 uint64_t obj;
261
262 ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
263 rrw_enter(&ds->ds_bp_rwlock, RW_READER, FTAG);
264 ASSERT3U(dsl_dataset_phys(ds)->ds_bp.blk_birth, <=, tx->tx_txg);
265 rrw_exit(&ds->ds_bp_rwlock, FTAG);
266 ASSERT(zfs_refcount_is_zero(&ds->ds_longholds));
267
268 if (defer &&
269 (ds->ds_userrefs > 0 ||
270 dsl_dataset_phys(ds)->ds_num_children > 1)) {
271 ASSERT(spa_version(dp->dp_spa) >= SPA_VERSION_USERREFS);
272 dmu_buf_will_dirty(ds->ds_dbuf, tx);
273 dsl_dataset_phys(ds)->ds_flags |= DS_FLAG_DEFER_DESTROY;
274 spa_history_log_internal_ds(ds, "defer_destroy", tx, "");
275 return;
276 }
277
278 ASSERT3U(dsl_dataset_phys(ds)->ds_num_children, <=, 1);
279
280 /* We need to log before removing it from the namespace. */
281 spa_history_log_internal_ds(ds, "destroy", tx, "");
282
283 dsl_scan_ds_destroyed(ds, tx);
284
285 obj = ds->ds_object;
286
287 for (spa_feature_t f = 0; f < SPA_FEATURES; f++) {
288 if (ds->ds_feature_inuse[f]) {
289 dsl_dataset_deactivate_feature(obj, f, tx);
290 ds->ds_feature_inuse[f] = B_FALSE;
291 }
292 }
293 if (dsl_dataset_phys(ds)->ds_prev_snap_obj != 0) {
294 ASSERT3P(ds->ds_prev, ==, NULL);
295 VERIFY0(dsl_dataset_hold_obj(dp,
296 dsl_dataset_phys(ds)->ds_prev_snap_obj, FTAG, &ds_prev));
297 after_branch_point =
298 (dsl_dataset_phys(ds_prev)->ds_next_snap_obj != obj);
299
300 dmu_buf_will_dirty(ds_prev->ds_dbuf, tx);
301 if (after_branch_point &&
302 dsl_dataset_phys(ds_prev)->ds_next_clones_obj != 0) {
303 dsl_dataset_remove_from_next_clones(ds_prev, obj, tx);
304 if (dsl_dataset_phys(ds)->ds_next_snap_obj != 0) {
305 VERIFY0(zap_add_int(mos,
306 dsl_dataset_phys(ds_prev)->
307 ds_next_clones_obj,
308 dsl_dataset_phys(ds)->ds_next_snap_obj,
309 tx));
310 }
311 }
312 if (!after_branch_point) {
313 dsl_dataset_phys(ds_prev)->ds_next_snap_obj =
314 dsl_dataset_phys(ds)->ds_next_snap_obj;
315 }
316 }
317
318 dsl_dataset_t *ds_next;
319 uint64_t old_unique;
320 uint64_t used = 0, comp = 0, uncomp = 0;
321
322 VERIFY0(dsl_dataset_hold_obj(dp,
323 dsl_dataset_phys(ds)->ds_next_snap_obj, FTAG, &ds_next));
324 ASSERT3U(dsl_dataset_phys(ds_next)->ds_prev_snap_obj, ==, obj);
325
326 old_unique = dsl_dataset_phys(ds_next)->ds_unique_bytes;
327
328 dmu_buf_will_dirty(ds_next->ds_dbuf, tx);
329 dsl_dataset_phys(ds_next)->ds_prev_snap_obj =
330 dsl_dataset_phys(ds)->ds_prev_snap_obj;
331 dsl_dataset_phys(ds_next)->ds_prev_snap_txg =
332 dsl_dataset_phys(ds)->ds_prev_snap_txg;
333 ASSERT3U(dsl_dataset_phys(ds)->ds_prev_snap_txg, ==,
334 ds_prev ? dsl_dataset_phys(ds_prev)->ds_creation_txg : 0);
335
336 if (ds_next->ds_deadlist.dl_oldfmt) {
337 process_old_deadlist(ds, ds_prev, ds_next,
338 after_branch_point, tx);
339 } else {
340 /* Adjust prev's unique space. */
341 if (ds_prev && !after_branch_point) {
342 dsl_deadlist_space_range(&ds_next->ds_deadlist,
343 dsl_dataset_phys(ds_prev)->ds_prev_snap_txg,
344 dsl_dataset_phys(ds)->ds_prev_snap_txg,
345 &used, &comp, &uncomp);
346 dsl_dataset_phys(ds_prev)->ds_unique_bytes += used;
347 }
348
349 /* Adjust snapused. */
350 dsl_deadlist_space_range(&ds_next->ds_deadlist,
351 dsl_dataset_phys(ds)->ds_prev_snap_txg, UINT64_MAX,
352 &used, &comp, &uncomp);
353 dsl_dir_diduse_space(ds->ds_dir, DD_USED_SNAP,
354 -used, -comp, -uncomp, tx);
355
356 /* Move blocks to be freed to pool's free list. */
357 dsl_deadlist_move_bpobj(&ds_next->ds_deadlist,
358 &dp->dp_free_bpobj, dsl_dataset_phys(ds)->ds_prev_snap_txg,
359 tx);
360 dsl_dir_diduse_space(tx->tx_pool->dp_free_dir,
361 DD_USED_HEAD, used, comp, uncomp, tx);
362
363 /* Merge our deadlist into next's and free it. */
364 dsl_deadlist_merge(&ds_next->ds_deadlist,
365 dsl_dataset_phys(ds)->ds_deadlist_obj, tx);
366 }
367
368 dsl_deadlist_close(&ds->ds_deadlist);
369 dsl_deadlist_free(mos, dsl_dataset_phys(ds)->ds_deadlist_obj, tx);
370 dmu_buf_will_dirty(ds->ds_dbuf, tx);
371 dsl_dataset_phys(ds)->ds_deadlist_obj = 0;
372
373 dsl_destroy_snapshot_handle_remaps(ds, ds_next, tx);
374
375 /* Collapse range in clone heads */
376 dsl_dataset_remove_clones_key(ds,
377 dsl_dataset_phys(ds)->ds_creation_txg, tx);
378
379 if (ds_next->ds_is_snapshot) {
380 dsl_dataset_t *ds_nextnext;
381
382 /*
383 * Update next's unique to include blocks which
384 * were previously shared by only this snapshot
385 * and it. Those blocks will be born after the
386 * prev snap and before this snap, and will have
387 * died after the next snap and before the one
388 * after that (ie. be on the snap after next's
389 * deadlist).
390 */
391 VERIFY0(dsl_dataset_hold_obj(dp,
392 dsl_dataset_phys(ds_next)->ds_next_snap_obj,
393 FTAG, &ds_nextnext));
394 dsl_deadlist_space_range(&ds_nextnext->ds_deadlist,
395 dsl_dataset_phys(ds)->ds_prev_snap_txg,
396 dsl_dataset_phys(ds)->ds_creation_txg,
397 &used, &comp, &uncomp);
398 dsl_dataset_phys(ds_next)->ds_unique_bytes += used;
399 dsl_dataset_rele(ds_nextnext, FTAG);
400 ASSERT3P(ds_next->ds_prev, ==, NULL);
401
402 /* Collapse range in this head. */
403 dsl_dataset_t *hds;
404 VERIFY0(dsl_dataset_hold_obj(dp,
405 dsl_dir_phys(ds->ds_dir)->dd_head_dataset_obj, FTAG, &hds));
406 dsl_deadlist_remove_key(&hds->ds_deadlist,
407 dsl_dataset_phys(ds)->ds_creation_txg, tx);
408 if (dsl_dataset_remap_deadlist_exists(hds)) {
409 dsl_deadlist_remove_key(&hds->ds_remap_deadlist,
410 dsl_dataset_phys(ds)->ds_creation_txg, tx);
411 }
412 dsl_dataset_rele(hds, FTAG);
413
414 } else {
415 ASSERT3P(ds_next->ds_prev, ==, ds);
416 dsl_dataset_rele(ds_next->ds_prev, ds_next);
417 ds_next->ds_prev = NULL;
418 if (ds_prev) {
419 VERIFY0(dsl_dataset_hold_obj(dp,
420 dsl_dataset_phys(ds)->ds_prev_snap_obj,
421 ds_next, &ds_next->ds_prev));
422 }
423
424 dsl_dataset_recalc_head_uniq(ds_next);
425
426 /*
427 * Reduce the amount of our unconsumed refreservation
428 * being charged to our parent by the amount of
429 * new unique data we have gained.
430 */
431 if (old_unique < ds_next->ds_reserved) {
432 int64_t mrsdelta;
433 uint64_t new_unique =
434 dsl_dataset_phys(ds_next)->ds_unique_bytes;
435
436 ASSERT(old_unique <= new_unique);
437 mrsdelta = MIN(new_unique - old_unique,
438 ds_next->ds_reserved - old_unique);
439 dsl_dir_diduse_space(ds->ds_dir,
440 DD_USED_REFRSRV, -mrsdelta, 0, 0, tx);
441 }
442 }
443 dsl_dataset_rele(ds_next, FTAG);
444
445 /*
446 * This must be done after the dsl_traverse(), because it will
447 * re-open the objset.
448 */
449 if (ds->ds_objset) {
450 dmu_objset_evict(ds->ds_objset);
451 ds->ds_objset = NULL;
452 }
453
454 /* remove from snapshot namespace */
455 dsl_dataset_t *ds_head;
456 ASSERT(dsl_dataset_phys(ds)->ds_snapnames_zapobj == 0);
457 VERIFY0(dsl_dataset_hold_obj(dp,
458 dsl_dir_phys(ds->ds_dir)->dd_head_dataset_obj, FTAG, &ds_head));
459 VERIFY0(dsl_dataset_get_snapname(ds));
460 #ifdef ZFS_DEBUG
461 {
462 uint64_t val;
463
464 err = dsl_dataset_snap_lookup(ds_head,
465 ds->ds_snapname, &val);
466 ASSERT0(err);
467 ASSERT3U(val, ==, obj);
468 }
469 #endif
470 VERIFY0(dsl_dataset_snap_remove(ds_head, ds->ds_snapname, tx, B_TRUE));
471 dsl_dataset_rele(ds_head, FTAG);
472
473 if (ds_prev != NULL)
474 dsl_dataset_rele(ds_prev, FTAG);
475
476 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx);
477
478 if (dsl_dataset_phys(ds)->ds_next_clones_obj != 0) {
479 uint64_t count;
480 ASSERT0(zap_count(mos,
481 dsl_dataset_phys(ds)->ds_next_clones_obj, &count) &&
482 count == 0);
483 VERIFY0(dmu_object_free(mos,
484 dsl_dataset_phys(ds)->ds_next_clones_obj, tx));
485 }
486 if (dsl_dataset_phys(ds)->ds_props_obj != 0)
487 VERIFY0(zap_destroy(mos, dsl_dataset_phys(ds)->ds_props_obj,
488 tx));
489 if (dsl_dataset_phys(ds)->ds_userrefs_obj != 0)
490 VERIFY0(zap_destroy(mos, dsl_dataset_phys(ds)->ds_userrefs_obj,
491 tx));
492 dsl_dir_rele(ds->ds_dir, ds);
493 ds->ds_dir = NULL;
494 dmu_object_free_zapified(mos, obj, tx);
495 }
496
497 void
dsl_destroy_snapshot_sync(void * arg,dmu_tx_t * tx)498 dsl_destroy_snapshot_sync(void *arg, dmu_tx_t *tx)
499 {
500 dsl_destroy_snapshot_arg_t *ddsa = arg;
501 const char *dsname = ddsa->ddsa_name;
502 boolean_t defer = ddsa->ddsa_defer;
503
504 dsl_pool_t *dp = dmu_tx_pool(tx);
505 dsl_dataset_t *ds;
506
507 int error = dsl_dataset_hold(dp, dsname, FTAG, &ds);
508 if (error == ENOENT)
509 return;
510 ASSERT0(error);
511 dsl_destroy_snapshot_sync_impl(ds, defer, tx);
512 dsl_dataset_rele(ds, FTAG);
513 }
514
515 /*
516 * The semantics of this function are described in the comment above
517 * lzc_destroy_snaps(). To summarize:
518 *
519 * The snapshots must all be in the same pool.
520 *
521 * Snapshots that don't exist will be silently ignored (considered to be
522 * "already deleted").
523 *
524 * On success, all snaps will be destroyed and this will return 0.
525 * On failure, no snaps will be destroyed, the errlist will be filled in,
526 * and this will return an errno.
527 */
528 int
dsl_destroy_snapshots_nvl(nvlist_t * snaps,boolean_t defer,nvlist_t * errlist)529 dsl_destroy_snapshots_nvl(nvlist_t *snaps, boolean_t defer,
530 nvlist_t *errlist)
531 {
532 if (nvlist_next_nvpair(snaps, NULL) == NULL)
533 return (0);
534
535 /*
536 * lzc_destroy_snaps() is documented to take an nvlist whose
537 * values "don't matter". We need to convert that nvlist to
538 * one that we know can be converted to LUA. We also don't
539 * care about any duplicate entries because the nvlist will
540 * be converted to a LUA table which should take care of this.
541 */
542 nvlist_t *snaps_normalized;
543 VERIFY0(nvlist_alloc(&snaps_normalized, 0, KM_SLEEP));
544 for (nvpair_t *pair = nvlist_next_nvpair(snaps, NULL);
545 pair != NULL; pair = nvlist_next_nvpair(snaps, pair)) {
546 fnvlist_add_boolean_value(snaps_normalized,
547 nvpair_name(pair), B_TRUE);
548 }
549
550 nvlist_t *arg;
551 VERIFY0(nvlist_alloc(&arg, 0, KM_SLEEP));
552 fnvlist_add_nvlist(arg, "snaps", snaps_normalized);
553 fnvlist_free(snaps_normalized);
554 fnvlist_add_boolean_value(arg, "defer", defer);
555
556 nvlist_t *wrapper;
557 VERIFY0(nvlist_alloc(&wrapper, 0, KM_SLEEP));
558 fnvlist_add_nvlist(wrapper, ZCP_ARG_ARGLIST, arg);
559 fnvlist_free(arg);
560
561 const char *program =
562 "arg = ...\n"
563 "snaps = arg['snaps']\n"
564 "defer = arg['defer']\n"
565 "errors = { }\n"
566 "has_errors = false\n"
567 "for snap, v in pairs(snaps) do\n"
568 " errno = zfs.check.destroy{snap, defer=defer}\n"
569 " zfs.debug('snap: ' .. snap .. ' errno: ' .. errno)\n"
570 " if errno == ENOENT then\n"
571 " snaps[snap] = nil\n"
572 " elseif errno ~= 0 then\n"
573 " errors[snap] = errno\n"
574 " has_errors = true\n"
575 " end\n"
576 "end\n"
577 "if has_errors then\n"
578 " return errors\n"
579 "end\n"
580 "for snap, v in pairs(snaps) do\n"
581 " errno = zfs.sync.destroy{snap, defer=defer}\n"
582 " assert(errno == 0)\n"
583 "end\n"
584 "return { }\n";
585
586 nvlist_t *result = fnvlist_alloc();
587 int error = zcp_eval(nvpair_name(nvlist_next_nvpair(snaps, NULL)),
588 program,
589 B_TRUE,
590 0,
591 zfs_lua_max_memlimit,
592 nvlist_next_nvpair(wrapper, NULL), result);
593 if (error != 0) {
594 char *errorstr = NULL;
595 (void) nvlist_lookup_string(result, ZCP_RET_ERROR, &errorstr);
596 if (errorstr != NULL) {
597 zfs_dbgmsg(errorstr);
598 }
599 return (error);
600 }
601 fnvlist_free(wrapper);
602
603 /*
604 * lzc_destroy_snaps() is documented to fill the errlist with
605 * int32 values, so we need to covert the int64 values that are
606 * returned from LUA.
607 */
608 int rv = 0;
609 nvlist_t *errlist_raw = fnvlist_lookup_nvlist(result, ZCP_RET_RETURN);
610 for (nvpair_t *pair = nvlist_next_nvpair(errlist_raw, NULL);
611 pair != NULL; pair = nvlist_next_nvpair(errlist_raw, pair)) {
612 int32_t val = (int32_t)fnvpair_value_int64(pair);
613 if (rv == 0)
614 rv = val;
615 fnvlist_add_int32(errlist, nvpair_name(pair), val);
616 }
617 fnvlist_free(result);
618 return (rv);
619 }
620
621 int
dsl_destroy_snapshot(const char * name,boolean_t defer)622 dsl_destroy_snapshot(const char *name, boolean_t defer)
623 {
624 int error;
625 nvlist_t *nvl = fnvlist_alloc();
626 nvlist_t *errlist = fnvlist_alloc();
627
628 fnvlist_add_boolean(nvl, name);
629 error = dsl_destroy_snapshots_nvl(nvl, defer, errlist);
630 fnvlist_free(errlist);
631 fnvlist_free(nvl);
632 return (error);
633 }
634
635 struct killarg {
636 dsl_dataset_t *ds;
637 dmu_tx_t *tx;
638 };
639
640 /* ARGSUSED */
641 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)642 kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
643 const zbookmark_phys_t *zb, const dnode_phys_t *dnp, void *arg)
644 {
645 struct killarg *ka = arg;
646 dmu_tx_t *tx = ka->tx;
647
648 if (bp == NULL || BP_IS_HOLE(bp) || BP_IS_EMBEDDED(bp))
649 return (0);
650
651 if (zb->zb_level == ZB_ZIL_LEVEL) {
652 ASSERT(zilog != NULL);
653 /*
654 * It's a block in the intent log. It has no
655 * accounting, so just free it.
656 */
657 dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp);
658 } else {
659 ASSERT(zilog == NULL);
660 ASSERT3U(bp->blk_birth, >,
661 dsl_dataset_phys(ka->ds)->ds_prev_snap_txg);
662 (void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE);
663 }
664
665 return (0);
666 }
667
668 static void
old_synchronous_dataset_destroy(dsl_dataset_t * ds,dmu_tx_t * tx)669 old_synchronous_dataset_destroy(dsl_dataset_t *ds, dmu_tx_t *tx)
670 {
671 struct killarg ka;
672
673 /*
674 * Free everything that we point to (that's born after
675 * the previous snapshot, if we are a clone)
676 *
677 * NB: this should be very quick, because we already
678 * freed all the objects in open context.
679 */
680 ka.ds = ds;
681 ka.tx = tx;
682 VERIFY0(traverse_dataset(ds,
683 dsl_dataset_phys(ds)->ds_prev_snap_txg, TRAVERSE_POST |
684 TRAVERSE_NO_DECRYPT, kill_blkptr, &ka));
685 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) ||
686 dsl_dataset_phys(ds)->ds_unique_bytes == 0);
687 }
688
689 int
dsl_destroy_head_check_impl(dsl_dataset_t * ds,int expected_holds)690 dsl_destroy_head_check_impl(dsl_dataset_t *ds, int expected_holds)
691 {
692 int error;
693 uint64_t count;
694 objset_t *mos;
695
696 ASSERT(!ds->ds_is_snapshot);
697 if (ds->ds_is_snapshot)
698 return (SET_ERROR(EINVAL));
699
700 if (zfs_refcount_count(&ds->ds_longholds) != expected_holds)
701 return (SET_ERROR(EBUSY));
702
703 mos = ds->ds_dir->dd_pool->dp_meta_objset;
704
705 /*
706 * Can't delete a head dataset if there are snapshots of it.
707 * (Except if the only snapshots are from the branch we cloned
708 * from.)
709 */
710 if (ds->ds_prev != NULL &&
711 dsl_dataset_phys(ds->ds_prev)->ds_next_snap_obj == ds->ds_object)
712 return (SET_ERROR(EBUSY));
713
714 /*
715 * Can't delete if there are children of this fs.
716 */
717 error = zap_count(mos,
718 dsl_dir_phys(ds->ds_dir)->dd_child_dir_zapobj, &count);
719 if (error != 0)
720 return (error);
721 if (count != 0)
722 return (SET_ERROR(EEXIST));
723
724 if (dsl_dir_is_clone(ds->ds_dir) && DS_IS_DEFER_DESTROY(ds->ds_prev) &&
725 dsl_dataset_phys(ds->ds_prev)->ds_num_children == 2 &&
726 ds->ds_prev->ds_userrefs == 0) {
727 /* We need to remove the origin snapshot as well. */
728 if (!zfs_refcount_is_zero(&ds->ds_prev->ds_longholds))
729 return (SET_ERROR(EBUSY));
730 }
731 return (0);
732 }
733
734 int
dsl_destroy_head_check(void * arg,dmu_tx_t * tx)735 dsl_destroy_head_check(void *arg, dmu_tx_t *tx)
736 {
737 dsl_destroy_head_arg_t *ddha = arg;
738 dsl_pool_t *dp = dmu_tx_pool(tx);
739 dsl_dataset_t *ds;
740 int error;
741
742 error = dsl_dataset_hold(dp, ddha->ddha_name, FTAG, &ds);
743 if (error != 0)
744 return (error);
745
746 error = dsl_destroy_head_check_impl(ds, 0);
747 dsl_dataset_rele(ds, FTAG);
748 return (error);
749 }
750
751 static void
dsl_dir_destroy_sync(uint64_t ddobj,dmu_tx_t * tx)752 dsl_dir_destroy_sync(uint64_t ddobj, dmu_tx_t *tx)
753 {
754 dsl_dir_t *dd;
755 dsl_pool_t *dp = dmu_tx_pool(tx);
756 objset_t *mos = dp->dp_meta_objset;
757 dd_used_t t;
758
759 ASSERT(RRW_WRITE_HELD(&dmu_tx_pool(tx)->dp_config_rwlock));
760
761 VERIFY0(dsl_dir_hold_obj(dp, ddobj, NULL, FTAG, &dd));
762
763 ASSERT0(dsl_dir_phys(dd)->dd_head_dataset_obj);
764
765 /*
766 * Decrement the filesystem count for all parent filesystems.
767 *
768 * When we receive an incremental stream into a filesystem that already
769 * exists, a temporary clone is created. We never count this temporary
770 * clone, whose name begins with a '%'.
771 */
772 if (dd->dd_myname[0] != '%' && dd->dd_parent != NULL)
773 dsl_fs_ss_count_adjust(dd->dd_parent, -1,
774 DD_FIELD_FILESYSTEM_COUNT, tx);
775
776 /*
777 * Remove our reservation. The impl() routine avoids setting the
778 * actual property, which would require the (already destroyed) ds.
779 */
780 dsl_dir_set_reservation_sync_impl(dd, 0, tx);
781
782 ASSERT0(dsl_dir_phys(dd)->dd_used_bytes);
783 ASSERT0(dsl_dir_phys(dd)->dd_reserved);
784 for (t = 0; t < DD_USED_NUM; t++)
785 ASSERT0(dsl_dir_phys(dd)->dd_used_breakdown[t]);
786
787 if (dd->dd_crypto_obj != 0) {
788 dsl_crypto_key_destroy_sync(dd->dd_crypto_obj, tx);
789 (void) spa_keystore_unload_wkey_impl(dp->dp_spa, dd->dd_object);
790 }
791
792 VERIFY0(zap_destroy(mos, dsl_dir_phys(dd)->dd_child_dir_zapobj, tx));
793 VERIFY0(zap_destroy(mos, dsl_dir_phys(dd)->dd_props_zapobj, tx));
794 if (dsl_dir_phys(dd)->dd_clones != 0)
795 VERIFY0(zap_destroy(mos, dsl_dir_phys(dd)->dd_clones, tx));
796 VERIFY0(dsl_deleg_destroy(mos, dsl_dir_phys(dd)->dd_deleg_zapobj, tx));
797 VERIFY0(zap_remove(mos,
798 dsl_dir_phys(dd->dd_parent)->dd_child_dir_zapobj,
799 dd->dd_myname, tx));
800
801 dsl_dir_rele(dd, FTAG);
802 dmu_object_free_zapified(mos, ddobj, tx);
803 }
804
805 void
dsl_destroy_head_sync_impl(dsl_dataset_t * ds,dmu_tx_t * tx)806 dsl_destroy_head_sync_impl(dsl_dataset_t *ds, dmu_tx_t *tx)
807 {
808 dsl_pool_t *dp = dmu_tx_pool(tx);
809 objset_t *mos = dp->dp_meta_objset;
810 uint64_t obj, ddobj, prevobj = 0;
811 boolean_t rmorigin;
812
813 ASSERT3U(dsl_dataset_phys(ds)->ds_num_children, <=, 1);
814 ASSERT(ds->ds_prev == NULL ||
815 dsl_dataset_phys(ds->ds_prev)->ds_next_snap_obj != ds->ds_object);
816 rrw_enter(&ds->ds_bp_rwlock, RW_READER, FTAG);
817 ASSERT3U(dsl_dataset_phys(ds)->ds_bp.blk_birth, <=, tx->tx_txg);
818 rrw_exit(&ds->ds_bp_rwlock, FTAG);
819 ASSERT(RRW_WRITE_HELD(&dp->dp_config_rwlock));
820
821 /* We need to log before removing it from the namespace. */
822 spa_history_log_internal_ds(ds, "destroy", tx, "");
823
824 rmorigin = (dsl_dir_is_clone(ds->ds_dir) &&
825 DS_IS_DEFER_DESTROY(ds->ds_prev) &&
826 dsl_dataset_phys(ds->ds_prev)->ds_num_children == 2 &&
827 ds->ds_prev->ds_userrefs == 0);
828
829 /* Remove our reservation. */
830 if (ds->ds_reserved != 0) {
831 dsl_dataset_set_refreservation_sync_impl(ds,
832 (ZPROP_SRC_NONE | ZPROP_SRC_LOCAL | ZPROP_SRC_RECEIVED),
833 0, tx);
834 ASSERT0(ds->ds_reserved);
835 }
836
837 obj = ds->ds_object;
838
839 for (spa_feature_t f = 0; f < SPA_FEATURES; f++) {
840 if (ds->ds_feature_inuse[f]) {
841 dsl_dataset_deactivate_feature(obj, f, tx);
842 ds->ds_feature_inuse[f] = B_FALSE;
843 }
844 }
845
846 dsl_scan_ds_destroyed(ds, tx);
847
848 if (dsl_dataset_phys(ds)->ds_prev_snap_obj != 0) {
849 /* This is a clone */
850 ASSERT(ds->ds_prev != NULL);
851 ASSERT3U(dsl_dataset_phys(ds->ds_prev)->ds_next_snap_obj, !=,
852 obj);
853 ASSERT0(dsl_dataset_phys(ds)->ds_next_snap_obj);
854
855 dmu_buf_will_dirty(ds->ds_prev->ds_dbuf, tx);
856 if (dsl_dataset_phys(ds->ds_prev)->ds_next_clones_obj != 0) {
857 dsl_dataset_remove_from_next_clones(ds->ds_prev,
858 obj, tx);
859 }
860
861 ASSERT3U(dsl_dataset_phys(ds->ds_prev)->ds_num_children, >, 1);
862 dsl_dataset_phys(ds->ds_prev)->ds_num_children--;
863 }
864
865 /*
866 * Destroy the deadlist. Unless it's a clone, the
867 * deadlist should be empty since the dataset has no snapshots.
868 * (If it's a clone, it's safe to ignore the deadlist contents
869 * since they are still referenced by the origin snapshot.)
870 */
871 dsl_deadlist_close(&ds->ds_deadlist);
872 dsl_deadlist_free(mos, dsl_dataset_phys(ds)->ds_deadlist_obj, tx);
873 dmu_buf_will_dirty(ds->ds_dbuf, tx);
874 dsl_dataset_phys(ds)->ds_deadlist_obj = 0;
875
876 if (dsl_dataset_remap_deadlist_exists(ds))
877 dsl_dataset_destroy_remap_deadlist(ds, tx);
878
879 objset_t *os;
880 VERIFY0(dmu_objset_from_ds(ds, &os));
881
882 if (!spa_feature_is_enabled(dp->dp_spa, SPA_FEATURE_ASYNC_DESTROY)) {
883 old_synchronous_dataset_destroy(ds, tx);
884 } else {
885 /*
886 * Move the bptree into the pool's list of trees to
887 * clean up and update space accounting information.
888 */
889 uint64_t used, comp, uncomp;
890
891 zil_destroy_sync(dmu_objset_zil(os), tx);
892
893 if (!spa_feature_is_active(dp->dp_spa,
894 SPA_FEATURE_ASYNC_DESTROY)) {
895 dsl_scan_t *scn = dp->dp_scan;
896 spa_feature_incr(dp->dp_spa, SPA_FEATURE_ASYNC_DESTROY,
897 tx);
898 dp->dp_bptree_obj = bptree_alloc(mos, tx);
899 VERIFY0(zap_add(mos,
900 DMU_POOL_DIRECTORY_OBJECT,
901 DMU_POOL_BPTREE_OBJ, sizeof (uint64_t), 1,
902 &dp->dp_bptree_obj, tx));
903 ASSERT(!scn->scn_async_destroying);
904 scn->scn_async_destroying = B_TRUE;
905 }
906
907 used = dsl_dir_phys(ds->ds_dir)->dd_used_bytes;
908 comp = dsl_dir_phys(ds->ds_dir)->dd_compressed_bytes;
909 uncomp = dsl_dir_phys(ds->ds_dir)->dd_uncompressed_bytes;
910
911 ASSERT(!DS_UNIQUE_IS_ACCURATE(ds) ||
912 dsl_dataset_phys(ds)->ds_unique_bytes == used);
913
914 rrw_enter(&ds->ds_bp_rwlock, RW_READER, FTAG);
915 bptree_add(mos, dp->dp_bptree_obj,
916 &dsl_dataset_phys(ds)->ds_bp,
917 dsl_dataset_phys(ds)->ds_prev_snap_txg,
918 used, comp, uncomp, tx);
919 rrw_exit(&ds->ds_bp_rwlock, FTAG);
920 dsl_dir_diduse_space(ds->ds_dir, DD_USED_HEAD,
921 -used, -comp, -uncomp, tx);
922 dsl_dir_diduse_space(dp->dp_free_dir, DD_USED_HEAD,
923 used, comp, uncomp, tx);
924 }
925
926 if (ds->ds_prev != NULL) {
927 if (spa_version(dp->dp_spa) >= SPA_VERSION_DIR_CLONES) {
928 VERIFY0(zap_remove_int(mos,
929 dsl_dir_phys(ds->ds_prev->ds_dir)->dd_clones,
930 ds->ds_object, tx));
931 }
932 prevobj = ds->ds_prev->ds_object;
933 dsl_dataset_rele(ds->ds_prev, ds);
934 ds->ds_prev = NULL;
935 }
936
937 /*
938 * This must be done after the dsl_traverse(), because it will
939 * re-open the objset.
940 */
941 if (ds->ds_objset) {
942 dmu_objset_evict(ds->ds_objset);
943 ds->ds_objset = NULL;
944 }
945
946 /* Erase the link in the dir */
947 dmu_buf_will_dirty(ds->ds_dir->dd_dbuf, tx);
948 dsl_dir_phys(ds->ds_dir)->dd_head_dataset_obj = 0;
949 ddobj = ds->ds_dir->dd_object;
950 ASSERT(dsl_dataset_phys(ds)->ds_snapnames_zapobj != 0);
951 VERIFY0(zap_destroy(mos,
952 dsl_dataset_phys(ds)->ds_snapnames_zapobj, tx));
953
954 if (ds->ds_bookmarks != 0) {
955 VERIFY0(zap_destroy(mos, ds->ds_bookmarks, tx));
956 spa_feature_decr(dp->dp_spa, SPA_FEATURE_BOOKMARKS, tx);
957 }
958
959 spa_prop_clear_bootfs(dp->dp_spa, ds->ds_object, tx);
960
961 ASSERT0(dsl_dataset_phys(ds)->ds_next_clones_obj);
962 ASSERT0(dsl_dataset_phys(ds)->ds_props_obj);
963 ASSERT0(dsl_dataset_phys(ds)->ds_userrefs_obj);
964 dsl_dir_rele(ds->ds_dir, ds);
965 ds->ds_dir = NULL;
966 dmu_object_free_zapified(mos, obj, tx);
967
968 dsl_dir_destroy_sync(ddobj, tx);
969
970 if (rmorigin) {
971 dsl_dataset_t *prev;
972 VERIFY0(dsl_dataset_hold_obj(dp, prevobj, FTAG, &prev));
973 dsl_destroy_snapshot_sync_impl(prev, B_FALSE, tx);
974 dsl_dataset_rele(prev, FTAG);
975 }
976 }
977
978 void
dsl_destroy_head_sync(void * arg,dmu_tx_t * tx)979 dsl_destroy_head_sync(void *arg, dmu_tx_t *tx)
980 {
981 dsl_destroy_head_arg_t *ddha = arg;
982 dsl_pool_t *dp = dmu_tx_pool(tx);
983 dsl_dataset_t *ds;
984
985 VERIFY0(dsl_dataset_hold(dp, ddha->ddha_name, FTAG, &ds));
986 dsl_destroy_head_sync_impl(ds, tx);
987 dsl_dataset_rele(ds, FTAG);
988 }
989
990 static void
dsl_destroy_head_begin_sync(void * arg,dmu_tx_t * tx)991 dsl_destroy_head_begin_sync(void *arg, dmu_tx_t *tx)
992 {
993 dsl_destroy_head_arg_t *ddha = arg;
994 dsl_pool_t *dp = dmu_tx_pool(tx);
995 dsl_dataset_t *ds;
996
997 VERIFY0(dsl_dataset_hold(dp, ddha->ddha_name, FTAG, &ds));
998
999 /* Mark it as inconsistent on-disk, in case we crash */
1000 dmu_buf_will_dirty(ds->ds_dbuf, tx);
1001 dsl_dataset_phys(ds)->ds_flags |= DS_FLAG_INCONSISTENT;
1002
1003 spa_history_log_internal_ds(ds, "destroy begin", tx, "");
1004 dsl_dataset_rele(ds, FTAG);
1005 }
1006
1007 int
dsl_destroy_head(const char * name)1008 dsl_destroy_head(const char *name)
1009 {
1010 dsl_destroy_head_arg_t ddha;
1011 int error;
1012 spa_t *spa;
1013 boolean_t isenabled;
1014
1015 #ifdef _KERNEL
1016 zfs_destroy_unmount_origin(name);
1017 #endif
1018
1019 error = spa_open(name, &spa, FTAG);
1020 if (error != 0)
1021 return (error);
1022 isenabled = spa_feature_is_enabled(spa, SPA_FEATURE_ASYNC_DESTROY);
1023 spa_close(spa, FTAG);
1024
1025 ddha.ddha_name = name;
1026
1027 if (!isenabled) {
1028 objset_t *os;
1029
1030 error = dsl_sync_task(name, dsl_destroy_head_check,
1031 dsl_destroy_head_begin_sync, &ddha,
1032 0, ZFS_SPACE_CHECK_DESTROY);
1033 if (error != 0)
1034 return (error);
1035
1036 /*
1037 * Head deletion is processed in one txg on old pools;
1038 * remove the objects from open context so that the txg sync
1039 * is not too long.
1040 */
1041 error = dmu_objset_own(name, DMU_OST_ANY, B_FALSE, B_FALSE,
1042 FTAG, &os);
1043 if (error == 0) {
1044 uint64_t prev_snap_txg =
1045 dsl_dataset_phys(dmu_objset_ds(os))->
1046 ds_prev_snap_txg;
1047 for (uint64_t obj = 0; error == 0;
1048 error = dmu_object_next(os, &obj, FALSE,
1049 prev_snap_txg))
1050 (void) dmu_free_long_object(os, obj);
1051 /* sync out all frees */
1052 txg_wait_synced(dmu_objset_pool(os), 0);
1053 dmu_objset_disown(os, B_FALSE, FTAG);
1054 }
1055 }
1056
1057 return (dsl_sync_task(name, dsl_destroy_head_check,
1058 dsl_destroy_head_sync, &ddha, 0, ZFS_SPACE_CHECK_DESTROY));
1059 }
1060
1061 /*
1062 * Note, this function is used as the callback for dmu_objset_find(). We
1063 * always return 0 so that we will continue to find and process
1064 * inconsistent datasets, even if we encounter an error trying to
1065 * process one of them.
1066 */
1067 /* ARGSUSED */
1068 int
dsl_destroy_inconsistent(const char * dsname,void * arg)1069 dsl_destroy_inconsistent(const char *dsname, void *arg)
1070 {
1071 objset_t *os;
1072
1073 if (dmu_objset_hold(dsname, FTAG, &os) == 0) {
1074 boolean_t need_destroy = DS_IS_INCONSISTENT(dmu_objset_ds(os));
1075
1076 /*
1077 * If the dataset is inconsistent because a resumable receive
1078 * has failed, then do not destroy it.
1079 */
1080 if (dsl_dataset_has_resume_receive_state(dmu_objset_ds(os)))
1081 need_destroy = B_FALSE;
1082
1083 dmu_objset_rele(os, FTAG);
1084 if (need_destroy)
1085 (void) dsl_destroy_head(dsname);
1086 }
1087 return (0);
1088 }
1089