xref: /titanic_41/usr/src/uts/common/fs/zfs/dsl_deleg.c (revision 07925104db56e5c3eacc4865b918bd16af5cec59)
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  */
24 
25 /*
26  * DSL permissions are stored in a two level zap attribute
27  * mechanism.   The first level identifies the "class" of
28  * entry.  The class is identified by the first 2 letters of
29  * the attribute.  The second letter "l" or "d" identifies whether
30  * it is a local or descendent permission.  The first letter
31  * identifies the type of entry.
32  *
33  * ul$<id>    identifies permissions granted locally for this userid.
34  * ud$<id>    identifies permissions granted on descendent datasets for
35  *            this userid.
36  * Ul$<id>    identifies permission sets granted locally for this userid.
37  * Ud$<id>    identifies permission sets granted on descendent datasets for
38  *            this userid.
39  * gl$<id>    identifies permissions granted locally for this groupid.
40  * gd$<id>    identifies permissions granted on descendent datasets for
41  *            this groupid.
42  * Gl$<id>    identifies permission sets granted locally for this groupid.
43  * Gd$<id>    identifies permission sets granted on descendent datasets for
44  *            this groupid.
45  * el$        identifies permissions granted locally for everyone.
46  * ed$        identifies permissions granted on descendent datasets
47  *            for everyone.
48  * El$        identifies permission sets granted locally for everyone.
49  * Ed$        identifies permission sets granted to descendent datasets for
50  *            everyone.
51  * c-$        identifies permission to create at dataset creation time.
52  * C-$        identifies permission sets to grant locally at dataset creation
53  *            time.
54  * s-$@<name> permissions defined in specified set @<name>
55  * S-$@<name> Sets defined in named set @<name>
56  *
57  * Each of the above entities points to another zap attribute that contains one
58  * attribute for each allowed permission, such as create, destroy,...
59  * All of the "upper" case class types will specify permission set names
60  * rather than permissions.
61  *
62  * Basically it looks something like this:
63  * ul$12 -> ZAP OBJ -> permissions...
64  *
65  * The ZAP OBJ is referred to as the jump object.
66  */
67 
68 #include <sys/dmu.h>
69 #include <sys/dmu_objset.h>
70 #include <sys/dmu_tx.h>
71 #include <sys/dsl_dataset.h>
72 #include <sys/dsl_dir.h>
73 #include <sys/dsl_prop.h>
74 #include <sys/dsl_synctask.h>
75 #include <sys/dsl_deleg.h>
76 #include <sys/spa.h>
77 #include <sys/zap.h>
78 #include <sys/fs/zfs.h>
79 #include <sys/cred.h>
80 #include <sys/sunddi.h>
81 
82 #include "zfs_deleg.h"
83 
84 /*
85  * Validate that user is allowed to delegate specified permissions.
86  *
87  * In order to delegate "create" you must have "create"
88  * and "allow".
89  */
90 int
91 dsl_deleg_can_allow(char *ddname, nvlist_t *nvp, cred_t *cr)
92 {
93 	nvpair_t *whopair = NULL;
94 	int error;
95 
96 	if ((error = dsl_deleg_access(ddname, ZFS_DELEG_PERM_ALLOW, cr)) != 0)
97 		return (error);
98 
99 	while (whopair = nvlist_next_nvpair(nvp, whopair)) {
100 		nvlist_t *perms;
101 		nvpair_t *permpair = NULL;
102 
103 		VERIFY(nvpair_value_nvlist(whopair, &perms) == 0);
104 
105 		while (permpair = nvlist_next_nvpair(perms, permpair)) {
106 			const char *perm = nvpair_name(permpair);
107 
108 			if (strcmp(perm, ZFS_DELEG_PERM_ALLOW) == 0)
109 				return (EPERM);
110 
111 			if ((error = dsl_deleg_access(ddname, perm, cr)) != 0)
112 				return (error);
113 		}
114 	}
115 	return (0);
116 }
117 
118 /*
119  * Validate that user is allowed to unallow specified permissions.  They
120  * must have the 'allow' permission, and even then can only unallow
121  * perms for their uid.
122  */
123 int
124 dsl_deleg_can_unallow(char *ddname, nvlist_t *nvp, cred_t *cr)
125 {
126 	nvpair_t *whopair = NULL;
127 	int error;
128 	char idstr[32];
129 
130 	if ((error = dsl_deleg_access(ddname, ZFS_DELEG_PERM_ALLOW, cr)) != 0)
131 		return (error);
132 
133 	(void) snprintf(idstr, sizeof (idstr), "%lld",
134 	    (longlong_t)crgetuid(cr));
135 
136 	while (whopair = nvlist_next_nvpair(nvp, whopair)) {
137 		zfs_deleg_who_type_t type = nvpair_name(whopair)[0];
138 
139 		if (type != ZFS_DELEG_USER &&
140 		    type != ZFS_DELEG_USER_SETS)
141 			return (EPERM);
142 
143 		if (strcmp(idstr, &nvpair_name(whopair)[3]) != 0)
144 			return (EPERM);
145 	}
146 	return (0);
147 }
148 
149 static void
150 dsl_deleg_set_sync(void *arg1, void *arg2, dmu_tx_t *tx)
151 {
152 	dsl_dir_t *dd = arg1;
153 	nvlist_t *nvp = arg2;
154 	objset_t *mos = dd->dd_pool->dp_meta_objset;
155 	nvpair_t *whopair = NULL;
156 	uint64_t zapobj = dd->dd_phys->dd_deleg_zapobj;
157 
158 	if (zapobj == 0) {
159 		dmu_buf_will_dirty(dd->dd_dbuf, tx);
160 		zapobj = dd->dd_phys->dd_deleg_zapobj = zap_create(mos,
161 		    DMU_OT_DSL_PERMS, DMU_OT_NONE, 0, tx);
162 	}
163 
164 	while (whopair = nvlist_next_nvpair(nvp, whopair)) {
165 		const char *whokey = nvpair_name(whopair);
166 		nvlist_t *perms;
167 		nvpair_t *permpair = NULL;
168 		uint64_t jumpobj;
169 
170 		VERIFY(nvpair_value_nvlist(whopair, &perms) == 0);
171 
172 		if (zap_lookup(mos, zapobj, whokey, 8, 1, &jumpobj) != 0) {
173 			jumpobj = zap_create(mos, DMU_OT_DSL_PERMS,
174 			    DMU_OT_NONE, 0, tx);
175 			VERIFY(zap_update(mos, zapobj,
176 			    whokey, 8, 1, &jumpobj, tx) == 0);
177 		}
178 
179 		while (permpair = nvlist_next_nvpair(perms, permpair)) {
180 			const char *perm = nvpair_name(permpair);
181 			uint64_t n = 0;
182 
183 			VERIFY(zap_update(mos, jumpobj,
184 			    perm, 8, 1, &n, tx) == 0);
185 			spa_history_log_internal(LOG_DS_PERM_UPDATE,
186 			    dd->dd_pool->dp_spa, tx,
187 			    "%s %s dataset = %llu", whokey, perm,
188 			    dd->dd_phys->dd_head_dataset_obj);
189 		}
190 	}
191 }
192 
193 static void
194 dsl_deleg_unset_sync(void *arg1, void *arg2, dmu_tx_t *tx)
195 {
196 	dsl_dir_t *dd = arg1;
197 	nvlist_t *nvp = arg2;
198 	objset_t *mos = dd->dd_pool->dp_meta_objset;
199 	nvpair_t *whopair = NULL;
200 	uint64_t zapobj = dd->dd_phys->dd_deleg_zapobj;
201 
202 	if (zapobj == 0)
203 		return;
204 
205 	while (whopair = nvlist_next_nvpair(nvp, whopair)) {
206 		const char *whokey = nvpair_name(whopair);
207 		nvlist_t *perms;
208 		nvpair_t *permpair = NULL;
209 		uint64_t jumpobj;
210 
211 		if (nvpair_value_nvlist(whopair, &perms) != 0) {
212 			if (zap_lookup(mos, zapobj, whokey, 8,
213 			    1, &jumpobj) == 0) {
214 				(void) zap_remove(mos, zapobj, whokey, tx);
215 				VERIFY(0 == zap_destroy(mos, jumpobj, tx));
216 			}
217 			spa_history_log_internal(LOG_DS_PERM_WHO_REMOVE,
218 			    dd->dd_pool->dp_spa, tx,
219 			    "%s dataset = %llu", whokey,
220 			    dd->dd_phys->dd_head_dataset_obj);
221 			continue;
222 		}
223 
224 		if (zap_lookup(mos, zapobj, whokey, 8, 1, &jumpobj) != 0)
225 			continue;
226 
227 		while (permpair = nvlist_next_nvpair(perms, permpair)) {
228 			const char *perm = nvpair_name(permpair);
229 			uint64_t n = 0;
230 
231 			(void) zap_remove(mos, jumpobj, perm, tx);
232 			if (zap_count(mos, jumpobj, &n) == 0 && n == 0) {
233 				(void) zap_remove(mos, zapobj,
234 				    whokey, tx);
235 				VERIFY(0 == zap_destroy(mos,
236 				    jumpobj, tx));
237 			}
238 			spa_history_log_internal(LOG_DS_PERM_REMOVE,
239 			    dd->dd_pool->dp_spa, tx,
240 			    "%s %s dataset = %llu", whokey, perm,
241 			    dd->dd_phys->dd_head_dataset_obj);
242 		}
243 	}
244 }
245 
246 int
247 dsl_deleg_set(const char *ddname, nvlist_t *nvp, boolean_t unset)
248 {
249 	dsl_dir_t *dd;
250 	int error;
251 	nvpair_t *whopair = NULL;
252 	int blocks_modified = 0;
253 
254 	error = dsl_dir_open(ddname, FTAG, &dd, NULL);
255 	if (error)
256 		return (error);
257 
258 	if (spa_version(dmu_objset_spa(dd->dd_pool->dp_meta_objset)) <
259 	    SPA_VERSION_DELEGATED_PERMS) {
260 		dsl_dir_close(dd, FTAG);
261 		return (ENOTSUP);
262 	}
263 
264 	while (whopair = nvlist_next_nvpair(nvp, whopair))
265 		blocks_modified++;
266 
267 	error = dsl_sync_task_do(dd->dd_pool, NULL,
268 	    unset ? dsl_deleg_unset_sync : dsl_deleg_set_sync,
269 	    dd, nvp, blocks_modified);
270 	dsl_dir_close(dd, FTAG);
271 
272 	return (error);
273 }
274 
275 /*
276  * Find all 'allow' permissions from a given point and then continue
277  * traversing up to the root.
278  *
279  * This function constructs an nvlist of nvlists.
280  * each setpoint is an nvlist composed of an nvlist of an nvlist
281  * of the individual * users/groups/everyone/create
282  * permissions.
283  *
284  * The nvlist will look like this.
285  *
286  * { source fsname -> { whokeys { permissions,...}, ...}}
287  *
288  * The fsname nvpairs will be arranged in a bottom up order.  For example,
289  * if we have the following structure a/b/c then the nvpairs for the fsnames
290  * will be ordered a/b/c, a/b, a.
291  */
292 int
293 dsl_deleg_get(const char *ddname, nvlist_t **nvp)
294 {
295 	dsl_dir_t *dd, *startdd;
296 	dsl_pool_t *dp;
297 	int error;
298 	objset_t *mos;
299 
300 	error = dsl_dir_open(ddname, FTAG, &startdd, NULL);
301 	if (error)
302 		return (error);
303 
304 	dp = startdd->dd_pool;
305 	mos = dp->dp_meta_objset;
306 
307 	VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
308 
309 	rw_enter(&dp->dp_config_rwlock, RW_READER);
310 	for (dd = startdd; dd != NULL; dd = dd->dd_parent) {
311 		zap_cursor_t basezc;
312 		zap_attribute_t baseza;
313 		nvlist_t *sp_nvp;
314 		uint64_t n;
315 		char source[MAXNAMELEN];
316 
317 		if (dd->dd_phys->dd_deleg_zapobj &&
318 		    (zap_count(mos, dd->dd_phys->dd_deleg_zapobj,
319 		    &n) == 0) && n) {
320 			VERIFY(nvlist_alloc(&sp_nvp,
321 			    NV_UNIQUE_NAME, KM_SLEEP) == 0);
322 		} else {
323 			continue;
324 		}
325 
326 		for (zap_cursor_init(&basezc, mos,
327 		    dd->dd_phys->dd_deleg_zapobj);
328 		    zap_cursor_retrieve(&basezc, &baseza) == 0;
329 		    zap_cursor_advance(&basezc)) {
330 			zap_cursor_t zc;
331 			zap_attribute_t za;
332 			nvlist_t *perms_nvp;
333 
334 			ASSERT(baseza.za_integer_length == 8);
335 			ASSERT(baseza.za_num_integers == 1);
336 
337 			VERIFY(nvlist_alloc(&perms_nvp,
338 			    NV_UNIQUE_NAME, KM_SLEEP) == 0);
339 			for (zap_cursor_init(&zc, mos, baseza.za_first_integer);
340 			    zap_cursor_retrieve(&zc, &za) == 0;
341 			    zap_cursor_advance(&zc)) {
342 				VERIFY(nvlist_add_boolean(perms_nvp,
343 				    za.za_name) == 0);
344 			}
345 			zap_cursor_fini(&zc);
346 			VERIFY(nvlist_add_nvlist(sp_nvp, baseza.za_name,
347 			    perms_nvp) == 0);
348 			nvlist_free(perms_nvp);
349 		}
350 
351 		zap_cursor_fini(&basezc);
352 
353 		dsl_dir_name(dd, source);
354 		VERIFY(nvlist_add_nvlist(*nvp, source, sp_nvp) == 0);
355 		nvlist_free(sp_nvp);
356 	}
357 	rw_exit(&dp->dp_config_rwlock);
358 
359 	dsl_dir_close(startdd, FTAG);
360 	return (0);
361 }
362 
363 /*
364  * Routines for dsl_deleg_access() -- access checking.
365  */
366 typedef struct perm_set {
367 	avl_node_t	p_node;
368 	boolean_t	p_matched;
369 	char		p_setname[ZFS_MAX_DELEG_NAME];
370 } perm_set_t;
371 
372 static int
373 perm_set_compare(const void *arg1, const void *arg2)
374 {
375 	const perm_set_t *node1 = arg1;
376 	const perm_set_t *node2 = arg2;
377 	int val;
378 
379 	val = strcmp(node1->p_setname, node2->p_setname);
380 	if (val == 0)
381 		return (0);
382 	return (val > 0 ? 1 : -1);
383 }
384 
385 /*
386  * Determine whether a specified permission exists.
387  *
388  * First the base attribute has to be retrieved.  i.e. ul$12
389  * Once the base object has been retrieved the actual permission
390  * is lookup up in the zap object the base object points to.
391  *
392  * Return 0 if permission exists, ENOENT if there is no whokey, EPERM if
393  * there is no perm in that jumpobj.
394  */
395 static int
396 dsl_check_access(objset_t *mos, uint64_t zapobj,
397     char type, char checkflag, void *valp, const char *perm)
398 {
399 	int error;
400 	uint64_t jumpobj, zero;
401 	char whokey[ZFS_MAX_DELEG_NAME];
402 
403 	zfs_deleg_whokey(whokey, type, checkflag, valp);
404 	error = zap_lookup(mos, zapobj, whokey, 8, 1, &jumpobj);
405 	if (error == 0) {
406 		error = zap_lookup(mos, jumpobj, perm, 8, 1, &zero);
407 		if (error == ENOENT)
408 			error = EPERM;
409 	}
410 	return (error);
411 }
412 
413 /*
414  * check a specified user/group for a requested permission
415  */
416 static int
417 dsl_check_user_access(objset_t *mos, uint64_t zapobj, const char *perm,
418     int checkflag, cred_t *cr)
419 {
420 	const	gid_t *gids;
421 	int	ngids;
422 	int	i;
423 	uint64_t id;
424 
425 	/* check for user */
426 	id = crgetuid(cr);
427 	if (dsl_check_access(mos, zapobj,
428 	    ZFS_DELEG_USER, checkflag, &id, perm) == 0)
429 		return (0);
430 
431 	/* check for users primary group */
432 	id = crgetgid(cr);
433 	if (dsl_check_access(mos, zapobj,
434 	    ZFS_DELEG_GROUP, checkflag, &id, perm) == 0)
435 		return (0);
436 
437 	/* check for everyone entry */
438 	id = -1;
439 	if (dsl_check_access(mos, zapobj,
440 	    ZFS_DELEG_EVERYONE, checkflag, &id, perm) == 0)
441 		return (0);
442 
443 	/* check each supplemental group user is a member of */
444 	ngids = crgetngroups(cr);
445 	gids = crgetgroups(cr);
446 	for (i = 0; i != ngids; i++) {
447 		id = gids[i];
448 		if (dsl_check_access(mos, zapobj,
449 		    ZFS_DELEG_GROUP, checkflag, &id, perm) == 0)
450 			return (0);
451 	}
452 
453 	return (EPERM);
454 }
455 
456 /*
457  * Iterate over the sets specified in the specified zapobj
458  * and load them into the permsets avl tree.
459  */
460 static int
461 dsl_load_sets(objset_t *mos, uint64_t zapobj,
462     char type, char checkflag, void *valp, avl_tree_t *avl)
463 {
464 	zap_cursor_t zc;
465 	zap_attribute_t za;
466 	perm_set_t *permnode;
467 	avl_index_t idx;
468 	uint64_t jumpobj;
469 	int error;
470 	char whokey[ZFS_MAX_DELEG_NAME];
471 
472 	zfs_deleg_whokey(whokey, type, checkflag, valp);
473 
474 	error = zap_lookup(mos, zapobj, whokey, 8, 1, &jumpobj);
475 	if (error != 0)
476 		return (error);
477 
478 	for (zap_cursor_init(&zc, mos, jumpobj);
479 	    zap_cursor_retrieve(&zc, &za) == 0;
480 	    zap_cursor_advance(&zc)) {
481 		permnode = kmem_alloc(sizeof (perm_set_t), KM_SLEEP);
482 		(void) strlcpy(permnode->p_setname, za.za_name,
483 		    sizeof (permnode->p_setname));
484 		permnode->p_matched = B_FALSE;
485 
486 		if (avl_find(avl, permnode, &idx) == NULL) {
487 			avl_insert(avl, permnode, idx);
488 		} else {
489 			kmem_free(permnode, sizeof (perm_set_t));
490 		}
491 	}
492 	zap_cursor_fini(&zc);
493 	return (0);
494 }
495 
496 /*
497  * Load all permissions user based on cred belongs to.
498  */
499 static void
500 dsl_load_user_sets(objset_t *mos, uint64_t zapobj, avl_tree_t *avl,
501     char checkflag, cred_t *cr)
502 {
503 	const	gid_t *gids;
504 	int	ngids, i;
505 	uint64_t id;
506 
507 	id = crgetuid(cr);
508 	(void) dsl_load_sets(mos, zapobj,
509 	    ZFS_DELEG_USER_SETS, checkflag, &id, avl);
510 
511 	id = crgetgid(cr);
512 	(void) dsl_load_sets(mos, zapobj,
513 	    ZFS_DELEG_GROUP_SETS, checkflag, &id, avl);
514 
515 	(void) dsl_load_sets(mos, zapobj,
516 	    ZFS_DELEG_EVERYONE_SETS, checkflag, NULL, avl);
517 
518 	ngids = crgetngroups(cr);
519 	gids = crgetgroups(cr);
520 	for (i = 0; i != ngids; i++) {
521 		id = gids[i];
522 		(void) dsl_load_sets(mos, zapobj,
523 		    ZFS_DELEG_GROUP_SETS, checkflag, &id, avl);
524 	}
525 }
526 
527 /*
528  * Check if user has requested permission.
529  */
530 int
531 dsl_deleg_access_impl(dsl_dataset_t *ds, const char *perm, cred_t *cr)
532 {
533 	dsl_dir_t *dd;
534 	dsl_pool_t *dp;
535 	void *cookie;
536 	int	error;
537 	char	checkflag;
538 	objset_t *mos;
539 	avl_tree_t permsets;
540 	perm_set_t *setnode;
541 
542 	dp = ds->ds_dir->dd_pool;
543 	mos = dp->dp_meta_objset;
544 
545 	if (dsl_delegation_on(mos) == B_FALSE)
546 		return (ECANCELED);
547 
548 	if (spa_version(dmu_objset_spa(dp->dp_meta_objset)) <
549 	    SPA_VERSION_DELEGATED_PERMS)
550 		return (EPERM);
551 
552 	if (dsl_dataset_is_snapshot(ds)) {
553 		/*
554 		 * Snapshots are treated as descendents only,
555 		 * local permissions do not apply.
556 		 */
557 		checkflag = ZFS_DELEG_DESCENDENT;
558 	} else {
559 		checkflag = ZFS_DELEG_LOCAL;
560 	}
561 
562 	avl_create(&permsets, perm_set_compare, sizeof (perm_set_t),
563 	    offsetof(perm_set_t, p_node));
564 
565 	rw_enter(&dp->dp_config_rwlock, RW_READER);
566 	for (dd = ds->ds_dir; dd != NULL; dd = dd->dd_parent,
567 	    checkflag = ZFS_DELEG_DESCENDENT) {
568 		uint64_t zapobj;
569 		boolean_t expanded;
570 
571 		/*
572 		 * If not in global zone then make sure
573 		 * the zoned property is set
574 		 */
575 		if (!INGLOBALZONE(curproc)) {
576 			uint64_t zoned;
577 
578 			if (dsl_prop_get_dd(dd,
579 			    zfs_prop_to_name(ZFS_PROP_ZONED),
580 			    8, 1, &zoned, NULL, B_FALSE) != 0)
581 				break;
582 			if (!zoned)
583 				break;
584 		}
585 		zapobj = dd->dd_phys->dd_deleg_zapobj;
586 
587 		if (zapobj == 0)
588 			continue;
589 
590 		dsl_load_user_sets(mos, zapobj, &permsets, checkflag, cr);
591 again:
592 		expanded = B_FALSE;
593 		for (setnode = avl_first(&permsets); setnode;
594 		    setnode = AVL_NEXT(&permsets, setnode)) {
595 			if (setnode->p_matched == B_TRUE)
596 				continue;
597 
598 			/* See if this set directly grants this permission */
599 			error = dsl_check_access(mos, zapobj,
600 			    ZFS_DELEG_NAMED_SET, 0, setnode->p_setname, perm);
601 			if (error == 0)
602 				goto success;
603 			if (error == EPERM)
604 				setnode->p_matched = B_TRUE;
605 
606 			/* See if this set includes other sets */
607 			error = dsl_load_sets(mos, zapobj,
608 			    ZFS_DELEG_NAMED_SET_SETS, 0,
609 			    setnode->p_setname, &permsets);
610 			if (error == 0)
611 				setnode->p_matched = expanded = B_TRUE;
612 		}
613 		/*
614 		 * If we expanded any sets, that will define more sets,
615 		 * which we need to check.
616 		 */
617 		if (expanded)
618 			goto again;
619 
620 		error = dsl_check_user_access(mos, zapobj, perm, checkflag, cr);
621 		if (error == 0)
622 			goto success;
623 	}
624 	error = EPERM;
625 success:
626 	rw_exit(&dp->dp_config_rwlock);
627 
628 	cookie = NULL;
629 	while ((setnode = avl_destroy_nodes(&permsets, &cookie)) != NULL)
630 		kmem_free(setnode, sizeof (perm_set_t));
631 
632 	return (error);
633 }
634 
635 int
636 dsl_deleg_access(const char *dsname, const char *perm, cred_t *cr)
637 {
638 	dsl_dataset_t *ds;
639 	int error;
640 
641 	error = dsl_dataset_hold(dsname, FTAG, &ds);
642 	if (error)
643 		return (error);
644 
645 	error = dsl_deleg_access_impl(ds, perm, cr);
646 	dsl_dataset_rele(ds, FTAG);
647 
648 	return (error);
649 }
650 
651 /*
652  * Other routines.
653  */
654 
655 static void
656 copy_create_perms(dsl_dir_t *dd, uint64_t pzapobj,
657     boolean_t dosets, uint64_t uid, dmu_tx_t *tx)
658 {
659 	objset_t *mos = dd->dd_pool->dp_meta_objset;
660 	uint64_t jumpobj, pjumpobj;
661 	uint64_t zapobj = dd->dd_phys->dd_deleg_zapobj;
662 	zap_cursor_t zc;
663 	zap_attribute_t za;
664 	char whokey[ZFS_MAX_DELEG_NAME];
665 
666 	zfs_deleg_whokey(whokey,
667 	    dosets ? ZFS_DELEG_CREATE_SETS : ZFS_DELEG_CREATE,
668 	    ZFS_DELEG_LOCAL, NULL);
669 	if (zap_lookup(mos, pzapobj, whokey, 8, 1, &pjumpobj) != 0)
670 		return;
671 
672 	if (zapobj == 0) {
673 		dmu_buf_will_dirty(dd->dd_dbuf, tx);
674 		zapobj = dd->dd_phys->dd_deleg_zapobj = zap_create(mos,
675 		    DMU_OT_DSL_PERMS, DMU_OT_NONE, 0, tx);
676 	}
677 
678 	zfs_deleg_whokey(whokey,
679 	    dosets ? ZFS_DELEG_USER_SETS : ZFS_DELEG_USER,
680 	    ZFS_DELEG_LOCAL, &uid);
681 	if (zap_lookup(mos, zapobj, whokey, 8, 1, &jumpobj) == ENOENT) {
682 		jumpobj = zap_create(mos, DMU_OT_DSL_PERMS, DMU_OT_NONE, 0, tx);
683 		VERIFY(zap_add(mos, zapobj, whokey, 8, 1, &jumpobj, tx) == 0);
684 	}
685 
686 	for (zap_cursor_init(&zc, mos, pjumpobj);
687 	    zap_cursor_retrieve(&zc, &za) == 0;
688 	    zap_cursor_advance(&zc)) {
689 		uint64_t zero = 0;
690 		ASSERT(za.za_integer_length == 8 && za.za_num_integers == 1);
691 
692 		VERIFY(zap_update(mos, jumpobj, za.za_name,
693 		    8, 1, &zero, tx) == 0);
694 	}
695 	zap_cursor_fini(&zc);
696 }
697 
698 /*
699  * set all create time permission on new dataset.
700  */
701 void
702 dsl_deleg_set_create_perms(dsl_dir_t *sdd, dmu_tx_t *tx, cred_t *cr)
703 {
704 	dsl_dir_t *dd;
705 	uint64_t uid = crgetuid(cr);
706 
707 	if (spa_version(dmu_objset_spa(sdd->dd_pool->dp_meta_objset)) <
708 	    SPA_VERSION_DELEGATED_PERMS)
709 		return;
710 
711 	for (dd = sdd->dd_parent; dd != NULL; dd = dd->dd_parent) {
712 		uint64_t pzapobj = dd->dd_phys->dd_deleg_zapobj;
713 
714 		if (pzapobj == 0)
715 			continue;
716 
717 		copy_create_perms(sdd, pzapobj, B_FALSE, uid, tx);
718 		copy_create_perms(sdd, pzapobj, B_TRUE, uid, tx);
719 	}
720 }
721 
722 int
723 dsl_deleg_destroy(objset_t *mos, uint64_t zapobj, dmu_tx_t *tx)
724 {
725 	zap_cursor_t zc;
726 	zap_attribute_t za;
727 
728 	if (zapobj == 0)
729 		return (0);
730 
731 	for (zap_cursor_init(&zc, mos, zapobj);
732 	    zap_cursor_retrieve(&zc, &za) == 0;
733 	    zap_cursor_advance(&zc)) {
734 		ASSERT(za.za_integer_length == 8 && za.za_num_integers == 1);
735 		VERIFY(0 == zap_destroy(mos, za.za_first_integer, tx));
736 	}
737 	zap_cursor_fini(&zc);
738 	VERIFY(0 == zap_destroy(mos, zapobj, tx));
739 	return (0);
740 }
741 
742 boolean_t
743 dsl_delegation_on(objset_t *os)
744 {
745 	return (!!spa_delegation(os->os_spa));
746 }
747