xref: /titanic_50/usr/src/uts/common/fs/zfs/zfs_fuid.c (revision b47b5b34b42fa8056577c43496cdb99a4c99f8d7)
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 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #include <sys/zfs_context.h>
27 #include <sys/sunddi.h>
28 #include <sys/dmu.h>
29 #include <sys/avl.h>
30 #include <sys/zap.h>
31 #include <sys/refcount.h>
32 #include <sys/nvpair.h>
33 #ifdef _KERNEL
34 #include <sys/kidmap.h>
35 #include <sys/sid.h>
36 #include <sys/zfs_vfsops.h>
37 #include <sys/zfs_znode.h>
38 #endif
39 #include <sys/zfs_fuid.h>
40 
41 /*
42  * FUID Domain table(s).
43  *
44  * The FUID table is stored as a packed nvlist of an array
45  * of nvlists which contain an index, domain string and offset
46  *
47  * During file system initialization the nvlist(s) are read and
48  * two AVL trees are created.  One tree is keyed by the index number
49  * and the other by the domain string.  Nodes are never removed from
50  * trees, but new entries may be added.  If a new entry is added then
51  * the zfsvfs->z_fuid_dirty flag is set to true and the caller will then
52  * be responsible for calling zfs_fuid_sync() to sync the changes to disk.
53  *
54  */
55 
56 #define	FUID_IDX	"fuid_idx"
57 #define	FUID_DOMAIN	"fuid_domain"
58 #define	FUID_OFFSET	"fuid_offset"
59 #define	FUID_NVP_ARRAY	"fuid_nvlist"
60 
61 typedef struct fuid_domain {
62 	avl_node_t	f_domnode;
63 	avl_node_t	f_idxnode;
64 	ksiddomain_t	*f_ksid;
65 	uint64_t	f_idx;
66 } fuid_domain_t;
67 
68 static char *nulldomain = "";
69 
70 /*
71  * Compare two indexes.
72  */
73 static int
74 idx_compare(const void *arg1, const void *arg2)
75 {
76 	const fuid_domain_t *node1 = arg1;
77 	const fuid_domain_t *node2 = arg2;
78 
79 	if (node1->f_idx < node2->f_idx)
80 		return (-1);
81 	else if (node1->f_idx > node2->f_idx)
82 		return (1);
83 	return (0);
84 }
85 
86 /*
87  * Compare two domain strings.
88  */
89 static int
90 domain_compare(const void *arg1, const void *arg2)
91 {
92 	const fuid_domain_t *node1 = arg1;
93 	const fuid_domain_t *node2 = arg2;
94 	int val;
95 
96 	val = strcmp(node1->f_ksid->kd_name, node2->f_ksid->kd_name);
97 	if (val == 0)
98 		return (0);
99 	return (val > 0 ? 1 : -1);
100 }
101 
102 void
103 zfs_fuid_avl_tree_create(avl_tree_t *idx_tree, avl_tree_t *domain_tree)
104 {
105 	avl_create(idx_tree, idx_compare,
106 	    sizeof (fuid_domain_t), offsetof(fuid_domain_t, f_idxnode));
107 	avl_create(domain_tree, domain_compare,
108 	    sizeof (fuid_domain_t), offsetof(fuid_domain_t, f_domnode));
109 }
110 
111 /*
112  * load initial fuid domain and idx trees.  This function is used by
113  * both the kernel and zdb.
114  */
115 uint64_t
116 zfs_fuid_table_load(objset_t *os, uint64_t fuid_obj, avl_tree_t *idx_tree,
117     avl_tree_t *domain_tree)
118 {
119 	dmu_buf_t *db;
120 	uint64_t fuid_size;
121 
122 	ASSERT(fuid_obj != 0);
123 	VERIFY(0 == dmu_bonus_hold(os, fuid_obj,
124 	    FTAG, &db));
125 	fuid_size = *(uint64_t *)db->db_data;
126 	dmu_buf_rele(db, FTAG);
127 
128 	if (fuid_size)  {
129 		nvlist_t **fuidnvp;
130 		nvlist_t *nvp = NULL;
131 		uint_t count;
132 		char *packed;
133 		int i;
134 
135 		packed = kmem_alloc(fuid_size, KM_SLEEP);
136 		VERIFY(dmu_read(os, fuid_obj, 0,
137 		    fuid_size, packed) == 0);
138 		VERIFY(nvlist_unpack(packed, fuid_size,
139 		    &nvp, 0) == 0);
140 		VERIFY(nvlist_lookup_nvlist_array(nvp, FUID_NVP_ARRAY,
141 		    &fuidnvp, &count) == 0);
142 
143 		for (i = 0; i != count; i++) {
144 			fuid_domain_t *domnode;
145 			char *domain;
146 			uint64_t idx;
147 
148 			VERIFY(nvlist_lookup_string(fuidnvp[i], FUID_DOMAIN,
149 			    &domain) == 0);
150 			VERIFY(nvlist_lookup_uint64(fuidnvp[i], FUID_IDX,
151 			    &idx) == 0);
152 
153 			domnode = kmem_alloc(sizeof (fuid_domain_t), KM_SLEEP);
154 
155 			domnode->f_idx = idx;
156 			domnode->f_ksid = ksid_lookupdomain(domain);
157 			avl_add(idx_tree, domnode);
158 			avl_add(domain_tree, domnode);
159 		}
160 		nvlist_free(nvp);
161 		kmem_free(packed, fuid_size);
162 	}
163 	return (fuid_size);
164 }
165 
166 void
167 zfs_fuid_table_destroy(avl_tree_t *idx_tree, avl_tree_t *domain_tree)
168 {
169 	fuid_domain_t *domnode;
170 	void *cookie;
171 
172 	cookie = NULL;
173 	while (domnode = avl_destroy_nodes(domain_tree, &cookie))
174 		ksiddomain_rele(domnode->f_ksid);
175 
176 	avl_destroy(domain_tree);
177 	cookie = NULL;
178 	while (domnode = avl_destroy_nodes(idx_tree, &cookie))
179 		kmem_free(domnode, sizeof (fuid_domain_t));
180 	avl_destroy(idx_tree);
181 }
182 
183 char *
184 zfs_fuid_idx_domain(avl_tree_t *idx_tree, uint32_t idx)
185 {
186 	fuid_domain_t searchnode, *findnode;
187 	avl_index_t loc;
188 
189 	searchnode.f_idx = idx;
190 
191 	findnode = avl_find(idx_tree, &searchnode, &loc);
192 
193 	return (findnode ? findnode->f_ksid->kd_name : nulldomain);
194 }
195 
196 #ifdef _KERNEL
197 /*
198  * Load the fuid table(s) into memory.
199  */
200 static void
201 zfs_fuid_init(zfsvfs_t *zfsvfs)
202 {
203 	rw_enter(&zfsvfs->z_fuid_lock, RW_WRITER);
204 
205 	if (zfsvfs->z_fuid_loaded) {
206 		rw_exit(&zfsvfs->z_fuid_lock);
207 		return;
208 	}
209 
210 	zfs_fuid_avl_tree_create(&zfsvfs->z_fuid_idx, &zfsvfs->z_fuid_domain);
211 
212 	(void) zap_lookup(zfsvfs->z_os, MASTER_NODE_OBJ,
213 	    ZFS_FUID_TABLES, 8, 1, &zfsvfs->z_fuid_obj);
214 	if (zfsvfs->z_fuid_obj != 0) {
215 		zfsvfs->z_fuid_size = zfs_fuid_table_load(zfsvfs->z_os,
216 		    zfsvfs->z_fuid_obj, &zfsvfs->z_fuid_idx,
217 		    &zfsvfs->z_fuid_domain);
218 	}
219 
220 	zfsvfs->z_fuid_loaded = B_TRUE;
221 	rw_exit(&zfsvfs->z_fuid_lock);
222 }
223 
224 /*
225  * sync out AVL trees to persistent storage.
226  */
227 void
228 zfs_fuid_sync(zfsvfs_t *zfsvfs, dmu_tx_t *tx)
229 {
230 	nvlist_t *nvp;
231 	nvlist_t **fuids;
232 	size_t nvsize = 0;
233 	char *packed;
234 	dmu_buf_t *db;
235 	fuid_domain_t *domnode;
236 	int numnodes;
237 	int i;
238 
239 	if (!zfsvfs->z_fuid_dirty) {
240 		return;
241 	}
242 
243 	rw_enter(&zfsvfs->z_fuid_lock, RW_WRITER);
244 
245 	/*
246 	 * First see if table needs to be created?
247 	 */
248 	if (zfsvfs->z_fuid_obj == 0) {
249 		zfsvfs->z_fuid_obj = dmu_object_alloc(zfsvfs->z_os,
250 		    DMU_OT_FUID, 1 << 14, DMU_OT_FUID_SIZE,
251 		    sizeof (uint64_t), tx);
252 		VERIFY(zap_add(zfsvfs->z_os, MASTER_NODE_OBJ,
253 		    ZFS_FUID_TABLES, sizeof (uint64_t), 1,
254 		    &zfsvfs->z_fuid_obj, tx) == 0);
255 	}
256 
257 	VERIFY(nvlist_alloc(&nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
258 
259 	numnodes = avl_numnodes(&zfsvfs->z_fuid_idx);
260 	fuids = kmem_alloc(numnodes * sizeof (void *), KM_SLEEP);
261 	for (i = 0, domnode = avl_first(&zfsvfs->z_fuid_domain); domnode; i++,
262 	    domnode = AVL_NEXT(&zfsvfs->z_fuid_domain, domnode)) {
263 		VERIFY(nvlist_alloc(&fuids[i], NV_UNIQUE_NAME, KM_SLEEP) == 0);
264 		VERIFY(nvlist_add_uint64(fuids[i], FUID_IDX,
265 		    domnode->f_idx) == 0);
266 		VERIFY(nvlist_add_uint64(fuids[i], FUID_OFFSET, 0) == 0);
267 		VERIFY(nvlist_add_string(fuids[i], FUID_DOMAIN,
268 		    domnode->f_ksid->kd_name) == 0);
269 	}
270 	VERIFY(nvlist_add_nvlist_array(nvp, FUID_NVP_ARRAY,
271 	    fuids, numnodes) == 0);
272 	for (i = 0; i != numnodes; i++)
273 		nvlist_free(fuids[i]);
274 	kmem_free(fuids, numnodes * sizeof (void *));
275 	VERIFY(nvlist_size(nvp, &nvsize, NV_ENCODE_XDR) == 0);
276 	packed = kmem_alloc(nvsize, KM_SLEEP);
277 	VERIFY(nvlist_pack(nvp, &packed, &nvsize,
278 	    NV_ENCODE_XDR, KM_SLEEP) == 0);
279 	nvlist_free(nvp);
280 	zfsvfs->z_fuid_size = nvsize;
281 	dmu_write(zfsvfs->z_os, zfsvfs->z_fuid_obj, 0,
282 	    zfsvfs->z_fuid_size, packed, tx);
283 	kmem_free(packed, zfsvfs->z_fuid_size);
284 	VERIFY(0 == dmu_bonus_hold(zfsvfs->z_os, zfsvfs->z_fuid_obj,
285 	    FTAG, &db));
286 	dmu_buf_will_dirty(db, tx);
287 	*(uint64_t *)db->db_data = zfsvfs->z_fuid_size;
288 	dmu_buf_rele(db, FTAG);
289 
290 	zfsvfs->z_fuid_dirty = B_FALSE;
291 	rw_exit(&zfsvfs->z_fuid_lock);
292 }
293 
294 /*
295  * Query domain table for a given domain.
296  *
297  * If domain isn't found it is added to AVL trees and
298  * the zfsvfs->z_fuid_dirty flag will be set to TRUE.
299  * it will then be necessary for the caller or another
300  * thread to detect the dirty table and sync out the changes.
301  */
302 static int
303 zfs_fuid_find_by_domain(zfsvfs_t *zfsvfs, const char *domain, char **retdomain)
304 {
305 	fuid_domain_t searchnode, *findnode;
306 	avl_index_t loc;
307 	krw_t rw = RW_READER;
308 
309 	/*
310 	 * If the dummy "nobody" domain then return an index of 0
311 	 * to cause the created FUID to be a standard POSIX id
312 	 * for the user nobody.
313 	 */
314 	if (domain[0] == '\0') {
315 		*retdomain = nulldomain;
316 		return (0);
317 	}
318 
319 	searchnode.f_ksid = ksid_lookupdomain(domain);
320 	if (retdomain) {
321 		*retdomain = searchnode.f_ksid->kd_name;
322 	}
323 	if (!zfsvfs->z_fuid_loaded)
324 		zfs_fuid_init(zfsvfs);
325 
326 retry:
327 	rw_enter(&zfsvfs->z_fuid_lock, rw);
328 	findnode = avl_find(&zfsvfs->z_fuid_domain, &searchnode, &loc);
329 
330 	if (findnode) {
331 		rw_exit(&zfsvfs->z_fuid_lock);
332 		ksiddomain_rele(searchnode.f_ksid);
333 		return (findnode->f_idx);
334 	} else {
335 		fuid_domain_t *domnode;
336 		uint64_t retidx;
337 
338 		if (rw == RW_READER && !rw_tryupgrade(&zfsvfs->z_fuid_lock)) {
339 			rw_exit(&zfsvfs->z_fuid_lock);
340 			rw = RW_WRITER;
341 			goto retry;
342 		}
343 
344 		domnode = kmem_alloc(sizeof (fuid_domain_t), KM_SLEEP);
345 		domnode->f_ksid = searchnode.f_ksid;
346 
347 		retidx = domnode->f_idx = avl_numnodes(&zfsvfs->z_fuid_idx) + 1;
348 
349 		avl_add(&zfsvfs->z_fuid_domain, domnode);
350 		avl_add(&zfsvfs->z_fuid_idx, domnode);
351 		zfsvfs->z_fuid_dirty = B_TRUE;
352 		rw_exit(&zfsvfs->z_fuid_lock);
353 		return (retidx);
354 	}
355 }
356 
357 /*
358  * Query domain table by index, returning domain string
359  *
360  * Returns a pointer from an avl node of the domain string.
361  *
362  */
363 static char *
364 zfs_fuid_find_by_idx(zfsvfs_t *zfsvfs, uint32_t idx)
365 {
366 	char *domain;
367 
368 	if (idx == 0 || !zfsvfs->z_use_fuids)
369 		return (NULL);
370 
371 	if (!zfsvfs->z_fuid_loaded)
372 		zfs_fuid_init(zfsvfs);
373 
374 	rw_enter(&zfsvfs->z_fuid_lock, RW_READER);
375 
376 	if (zfsvfs->z_fuid_obj)
377 		domain = zfs_fuid_idx_domain(&zfsvfs->z_fuid_idx, idx);
378 	else
379 		domain = nulldomain;
380 	rw_exit(&zfsvfs->z_fuid_lock);
381 
382 	ASSERT(domain);
383 	return (domain);
384 }
385 
386 void
387 zfs_fuid_map_ids(znode_t *zp, cred_t *cr, uid_t *uidp, uid_t *gidp)
388 {
389 	*uidp = zfs_fuid_map_id(zp->z_zfsvfs, zp->z_phys->zp_uid,
390 	    cr, ZFS_OWNER);
391 	*gidp = zfs_fuid_map_id(zp->z_zfsvfs, zp->z_phys->zp_gid,
392 	    cr, ZFS_GROUP);
393 }
394 
395 uid_t
396 zfs_fuid_map_id(zfsvfs_t *zfsvfs, uint64_t fuid,
397     cred_t *cr, zfs_fuid_type_t type)
398 {
399 	uint32_t index = FUID_INDEX(fuid);
400 	char *domain;
401 	uid_t id;
402 
403 	if (index == 0)
404 		return (fuid);
405 
406 	domain = zfs_fuid_find_by_idx(zfsvfs, index);
407 	ASSERT(domain != NULL);
408 
409 	if (type == ZFS_OWNER || type == ZFS_ACE_USER) {
410 		(void) kidmap_getuidbysid(crgetzone(cr), domain,
411 		    FUID_RID(fuid), &id);
412 	} else {
413 		(void) kidmap_getgidbysid(crgetzone(cr), domain,
414 		    FUID_RID(fuid), &id);
415 	}
416 	return (id);
417 }
418 
419 /*
420  * Add a FUID node to the list of fuid's being created for this
421  * ACL
422  *
423  * If ACL has multiple domains, then keep only one copy of each unique
424  * domain.
425  */
426 static void
427 zfs_fuid_node_add(zfs_fuid_info_t **fuidpp, const char *domain, uint32_t rid,
428     uint64_t idx, uint64_t id, zfs_fuid_type_t type)
429 {
430 	zfs_fuid_t *fuid;
431 	zfs_fuid_domain_t *fuid_domain;
432 	zfs_fuid_info_t *fuidp;
433 	uint64_t fuididx;
434 	boolean_t found = B_FALSE;
435 
436 	if (*fuidpp == NULL)
437 		*fuidpp = zfs_fuid_info_alloc();
438 
439 	fuidp = *fuidpp;
440 	/*
441 	 * First find fuid domain index in linked list
442 	 *
443 	 * If one isn't found then create an entry.
444 	 */
445 
446 	for (fuididx = 1, fuid_domain = list_head(&fuidp->z_domains);
447 	    fuid_domain; fuid_domain = list_next(&fuidp->z_domains,
448 	    fuid_domain), fuididx++) {
449 		if (idx == fuid_domain->z_domidx) {
450 			found = B_TRUE;
451 			break;
452 		}
453 	}
454 
455 	if (!found) {
456 		fuid_domain = kmem_alloc(sizeof (zfs_fuid_domain_t), KM_SLEEP);
457 		fuid_domain->z_domain = domain;
458 		fuid_domain->z_domidx = idx;
459 		list_insert_tail(&fuidp->z_domains, fuid_domain);
460 		fuidp->z_domain_str_sz += strlen(domain) + 1;
461 		fuidp->z_domain_cnt++;
462 	}
463 
464 	if (type == ZFS_ACE_USER || type == ZFS_ACE_GROUP) {
465 
466 		/*
467 		 * Now allocate fuid entry and add it on the end of the list
468 		 */
469 
470 		fuid = kmem_alloc(sizeof (zfs_fuid_t), KM_SLEEP);
471 		fuid->z_id = id;
472 		fuid->z_domidx = idx;
473 		fuid->z_logfuid = FUID_ENCODE(fuididx, rid);
474 
475 		list_insert_tail(&fuidp->z_fuids, fuid);
476 		fuidp->z_fuid_cnt++;
477 	} else {
478 		if (type == ZFS_OWNER)
479 			fuidp->z_fuid_owner = FUID_ENCODE(fuididx, rid);
480 		else
481 			fuidp->z_fuid_group = FUID_ENCODE(fuididx, rid);
482 	}
483 }
484 
485 /*
486  * Create a file system FUID, based on information in the users cred
487  */
488 uint64_t
489 zfs_fuid_create_cred(zfsvfs_t *zfsvfs, zfs_fuid_type_t type,
490     cred_t *cr, zfs_fuid_info_t **fuidp)
491 {
492 	uint64_t	idx;
493 	ksid_t		*ksid;
494 	uint32_t	rid;
495 	char 		*kdomain;
496 	const char	*domain;
497 	uid_t		id;
498 
499 	VERIFY(type == ZFS_OWNER || type == ZFS_GROUP);
500 
501 	ksid = crgetsid(cr, (type == ZFS_OWNER) ? KSID_OWNER : KSID_GROUP);
502 	if (ksid) {
503 		id = ksid_getid(ksid);
504 	} else {
505 		if (type == ZFS_OWNER)
506 			id = crgetuid(cr);
507 		else
508 			id = crgetgid(cr);
509 	}
510 
511 	if (!zfsvfs->z_use_fuids || (!IS_EPHEMERAL(id)))
512 		return ((uint64_t)id);
513 
514 	rid = ksid_getrid(ksid);
515 	domain = ksid_getdomain(ksid);
516 
517 	idx = zfs_fuid_find_by_domain(zfsvfs, domain, &kdomain);
518 
519 	zfs_fuid_node_add(fuidp, kdomain, rid, idx, id, type);
520 
521 	return (FUID_ENCODE(idx, rid));
522 }
523 
524 /*
525  * Create a file system FUID for an ACL ace
526  * or a chown/chgrp of the file.
527  * This is similar to zfs_fuid_create_cred, except that
528  * we can't find the domain + rid information in the
529  * cred.  Instead we have to query Winchester for the
530  * domain and rid.
531  *
532  * During replay operations the domain+rid information is
533  * found in the zfs_fuid_info_t that the replay code has
534  * attached to the zfsvfs of the file system.
535  */
536 uint64_t
537 zfs_fuid_create(zfsvfs_t *zfsvfs, uint64_t id, cred_t *cr,
538     zfs_fuid_type_t type, zfs_fuid_info_t **fuidpp)
539 {
540 	const char *domain;
541 	char *kdomain;
542 	uint32_t fuid_idx = FUID_INDEX(id);
543 	uint32_t rid;
544 	idmap_stat status;
545 	uint64_t idx;
546 	zfs_fuid_t *zfuid = NULL;
547 	zfs_fuid_info_t *fuidp;
548 
549 	/*
550 	 * If POSIX ID, or entry is already a FUID then
551 	 * just return the id
552 	 *
553 	 * We may also be handed an already FUID'ized id via
554 	 * chmod.
555 	 */
556 
557 	if (!zfsvfs->z_use_fuids || !IS_EPHEMERAL(id) || fuid_idx != 0)
558 		return (id);
559 
560 	if (zfsvfs->z_replay) {
561 		fuidp = zfsvfs->z_fuid_replay;
562 
563 		/*
564 		 * If we are passed an ephemeral id, but no
565 		 * fuid_info was logged then return NOBODY.
566 		 * This is most likely a result of idmap service
567 		 * not being available.
568 		 */
569 		if (fuidp == NULL)
570 			return (UID_NOBODY);
571 
572 		switch (type) {
573 		case ZFS_ACE_USER:
574 		case ZFS_ACE_GROUP:
575 			zfuid = list_head(&fuidp->z_fuids);
576 			rid = FUID_RID(zfuid->z_logfuid);
577 			idx = FUID_INDEX(zfuid->z_logfuid);
578 			break;
579 		case ZFS_OWNER:
580 			rid = FUID_RID(fuidp->z_fuid_owner);
581 			idx = FUID_INDEX(fuidp->z_fuid_owner);
582 			break;
583 		case ZFS_GROUP:
584 			rid = FUID_RID(fuidp->z_fuid_group);
585 			idx = FUID_INDEX(fuidp->z_fuid_group);
586 			break;
587 		};
588 		domain = fuidp->z_domain_table[idx -1];
589 	} else {
590 		if (type == ZFS_OWNER || type == ZFS_ACE_USER)
591 			status = kidmap_getsidbyuid(crgetzone(cr), id,
592 			    &domain, &rid);
593 		else
594 			status = kidmap_getsidbygid(crgetzone(cr), id,
595 			    &domain, &rid);
596 
597 		if (status != 0) {
598 			/*
599 			 * When returning nobody we will need to
600 			 * make a dummy fuid table entry for logging
601 			 * purposes.
602 			 */
603 			rid = UID_NOBODY;
604 			domain = nulldomain;
605 		}
606 	}
607 
608 	idx = zfs_fuid_find_by_domain(zfsvfs, domain, &kdomain);
609 
610 	if (!zfsvfs->z_replay)
611 		zfs_fuid_node_add(fuidpp, kdomain,
612 		    rid, idx, id, type);
613 	else if (zfuid != NULL) {
614 		list_remove(&fuidp->z_fuids, zfuid);
615 		kmem_free(zfuid, sizeof (zfs_fuid_t));
616 	}
617 	return (FUID_ENCODE(idx, rid));
618 }
619 
620 void
621 zfs_fuid_destroy(zfsvfs_t *zfsvfs)
622 {
623 	rw_enter(&zfsvfs->z_fuid_lock, RW_WRITER);
624 	if (!zfsvfs->z_fuid_loaded) {
625 		rw_exit(&zfsvfs->z_fuid_lock);
626 		return;
627 	}
628 	zfs_fuid_table_destroy(&zfsvfs->z_fuid_idx, &zfsvfs->z_fuid_domain);
629 	rw_exit(&zfsvfs->z_fuid_lock);
630 }
631 
632 /*
633  * Allocate zfs_fuid_info for tracking FUIDs created during
634  * zfs_mknode, VOP_SETATTR() or VOP_SETSECATTR()
635  */
636 zfs_fuid_info_t *
637 zfs_fuid_info_alloc(void)
638 {
639 	zfs_fuid_info_t *fuidp;
640 
641 	fuidp = kmem_zalloc(sizeof (zfs_fuid_info_t), KM_SLEEP);
642 	list_create(&fuidp->z_domains, sizeof (zfs_fuid_domain_t),
643 	    offsetof(zfs_fuid_domain_t, z_next));
644 	list_create(&fuidp->z_fuids, sizeof (zfs_fuid_t),
645 	    offsetof(zfs_fuid_t, z_next));
646 	return (fuidp);
647 }
648 
649 /*
650  * Release all memory associated with zfs_fuid_info_t
651  */
652 void
653 zfs_fuid_info_free(zfs_fuid_info_t *fuidp)
654 {
655 	zfs_fuid_t *zfuid;
656 	zfs_fuid_domain_t *zdomain;
657 
658 	while ((zfuid = list_head(&fuidp->z_fuids)) != NULL) {
659 		list_remove(&fuidp->z_fuids, zfuid);
660 		kmem_free(zfuid, sizeof (zfs_fuid_t));
661 	}
662 
663 	if (fuidp->z_domain_table != NULL)
664 		kmem_free(fuidp->z_domain_table,
665 		    (sizeof (char **)) * fuidp->z_domain_cnt);
666 
667 	while ((zdomain = list_head(&fuidp->z_domains)) != NULL) {
668 		list_remove(&fuidp->z_domains, zdomain);
669 		kmem_free(zdomain, sizeof (zfs_fuid_domain_t));
670 	}
671 
672 	kmem_free(fuidp, sizeof (zfs_fuid_info_t));
673 }
674 
675 /*
676  * Check to see if id is a groupmember.  If cred
677  * has ksid info then sidlist is checked first
678  * and if still not found then POSIX groups are checked
679  *
680  * Will use a straight FUID compare when possible.
681  */
682 boolean_t
683 zfs_groupmember(zfsvfs_t *zfsvfs, uint64_t id, cred_t *cr)
684 {
685 	ksid_t		*ksid = crgetsid(cr, KSID_GROUP);
686 	uid_t		gid;
687 
688 	if (ksid) {
689 		int 		i;
690 		ksid_t		*ksid_groups;
691 		ksidlist_t	*ksidlist = crgetsidlist(cr);
692 		uint32_t	idx = FUID_INDEX(id);
693 		uint32_t	rid = FUID_RID(id);
694 
695 		ASSERT(ksidlist);
696 		ksid_groups = ksidlist->ksl_sids;
697 
698 		for (i = 0; i != ksidlist->ksl_nsid; i++) {
699 			if (idx == 0) {
700 				if (id != IDMAP_WK_CREATOR_GROUP_GID &&
701 				    id == ksid_groups[i].ks_id) {
702 					return (B_TRUE);
703 				}
704 			} else {
705 				char *domain;
706 
707 				domain = zfs_fuid_find_by_idx(zfsvfs, idx);
708 				ASSERT(domain != NULL);
709 
710 				if (strcmp(domain,
711 				    IDMAP_WK_CREATOR_SID_AUTHORITY) == 0)
712 					return (B_FALSE);
713 
714 				if ((strcmp(domain,
715 				    ksid_groups[i].ks_domain->kd_name) == 0) &&
716 				    rid == ksid_groups[i].ks_rid)
717 					return (B_TRUE);
718 			}
719 		}
720 	}
721 
722 	/*
723 	 * Not found in ksidlist, check posix groups
724 	 */
725 	gid = zfs_fuid_map_id(zfsvfs, id, cr, ZFS_GROUP);
726 	return (groupmember(gid, cr));
727 }
728 #endif
729