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NFSv3: Fix return value of nfs3_proc_setacls
[linux-2.6-block.git] / fs / posix_acl.c
CommitLineData
1da177e4 1/*
5c8ebd57 2 * Copyright (C) 2002,2003 by Andreas Gruenbacher <a.gruenbacher@computer.org>
1da177e4 3 *
5c8ebd57
CH		 4 * Fixes from William Schumacher incorporated on 15 March 2001.
5 * (Reported by Charles Bertsch, <CBertsch@microtest.com>).
1da177e4
LT		 6 */
7
8/*
9 * This file contains generic functions for manipulating
10 * POSIX 1003.1e draft standard 17 ACLs.
11 */
12
13#include <linux/kernel.h>
14#include <linux/slab.h>
60063497 15#include <linux/atomic.h>
1da177e4
LT		 16#include <linux/fs.h>
17#include <linux/sched.h>
18#include <linux/posix_acl.h>
5c8ebd57 19#include <linux/posix_acl_xattr.h>
2aeccbe9 20#include <linux/xattr.h>
630d9c47 21#include <linux/export.h>
5c8ebd57 22#include <linux/user_namespace.h>
1da177e4 23
0afaa120
AM		 24struct posix_acl **acl_by_type(struct inode *inode, int type)
25{
26 switch (type) {
27 case ACL_TYPE_ACCESS:
28 return &inode->i_acl;
29 case ACL_TYPE_DEFAULT:
30 return &inode->i_default_acl;
31 default:
32 BUG();
33 }
34}
35EXPORT_SYMBOL(acl_by_type);
36
37struct posix_acl *get_cached_acl(struct inode *inode, int type)
38{
39 struct posix_acl **p = acl_by_type(inode, type);
40 struct posix_acl *acl = ACCESS_ONCE(*p);
41 if (acl) {
42 spin_lock(&inode->i_lock);
43 acl = *p;
44 if (acl != ACL_NOT_CACHED)
45 acl = posix_acl_dup(acl);
46 spin_unlock(&inode->i_lock);
47 }
48 return acl;
49}
50EXPORT_SYMBOL(get_cached_acl);
51
52struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type)
53{
54 return rcu_dereference(*acl_by_type(inode, type));
55}
56EXPORT_SYMBOL(get_cached_acl_rcu);
57
58void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl)
59{
60 struct posix_acl **p = acl_by_type(inode, type);
61 struct posix_acl *old;
62 spin_lock(&inode->i_lock);
63 old = *p;
64 rcu_assign_pointer(*p, posix_acl_dup(acl));
65 spin_unlock(&inode->i_lock);
66 if (old != ACL_NOT_CACHED)
67 posix_acl_release(old);
68}
69EXPORT_SYMBOL(set_cached_acl);
70
71void forget_cached_acl(struct inode *inode, int type)
72{
73 struct posix_acl **p = acl_by_type(inode, type);
74 struct posix_acl *old;
75 spin_lock(&inode->i_lock);
76 old = *p;
77 *p = ACL_NOT_CACHED;
78 spin_unlock(&inode->i_lock);
79 if (old != ACL_NOT_CACHED)
80 posix_acl_release(old);
81}
82EXPORT_SYMBOL(forget_cached_acl);
83
84void forget_all_cached_acls(struct inode *inode)
85{
86 struct posix_acl *old_access, *old_default;
87 spin_lock(&inode->i_lock);
88 old_access = inode->i_acl;
89 old_default = inode->i_default_acl;
90 inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED;
91 spin_unlock(&inode->i_lock);
92 if (old_access != ACL_NOT_CACHED)
93 posix_acl_release(old_access);
94 if (old_default != ACL_NOT_CACHED)
95 posix_acl_release(old_default);
96}
97EXPORT_SYMBOL(forget_all_cached_acls);
1da177e4 98
2982baa2
CH		 99struct posix_acl *get_acl(struct inode *inode, int type)
100{
101 struct posix_acl *acl;
102
103 acl = get_cached_acl(inode, type);
104 if (acl != ACL_NOT_CACHED)
105 return acl;
106
107 if (!IS_POSIXACL(inode))
108 return NULL;
109
110 /*
111 * A filesystem can force a ACL callback by just never filling the
112 * ACL cache. But normally you'd fill the cache either at inode
113 * instantiation time, or on the first ->get_acl call.
114 *
115 * If the filesystem doesn't have a get_acl() function at all, we'll
116 * just create the negative cache entry.
117 */
118 if (!inode->i_op->get_acl) {
119 set_cached_acl(inode, type, NULL);
120 return NULL;
121 }
122 return inode->i_op->get_acl(inode, type);
123}
124EXPORT_SYMBOL(get_acl);
125
f61f6da0
CL		 126/*
127 * Init a fresh posix_acl
128 */
129void
130posix_acl_init(struct posix_acl *acl, int count)
131{
132 atomic_set(&acl->a_refcount, 1);
133 acl->a_count = count;
134}
0afaa120 135EXPORT_SYMBOL(posix_acl_init);
f61f6da0 136
1da177e4
LT		 137/*
138 * Allocate a new ACL with the specified number of entries.
139 */
140struct posix_acl *
dd0fc66f 141posix_acl_alloc(int count, gfp_t flags)
1da177e4
LT		 142{
143 const size_t size = sizeof(struct posix_acl) +
144 count * sizeof(struct posix_acl_entry);
145 struct posix_acl *acl = kmalloc(size, flags);
f61f6da0
CL		 146 if (acl)
147 posix_acl_init(acl, count);
1da177e4
LT		 148 return acl;
149}
0afaa120 150EXPORT_SYMBOL(posix_acl_alloc);
1da177e4
LT		 151
152/*
153 * Clone an ACL.
154 */
edde854e 155static struct posix_acl *
dd0fc66f 156posix_acl_clone(const struct posix_acl *acl, gfp_t flags)
1da177e4
LT		 157{
158 struct posix_acl *clone = NULL;
159
160 if (acl) {
161 int size = sizeof(struct posix_acl) + acl->a_count *
162 sizeof(struct posix_acl_entry);
52978be6
AD		 163 clone = kmemdup(acl, size, flags);
164 if (clone)
1da177e4 165 atomic_set(&clone->a_refcount, 1);
1da177e4
LT		 166 }
167 return clone;
168}
169
170/*
171 * Check if an acl is valid. Returns 0 if it is, or -E... otherwise.
172 */
173int
174posix_acl_valid(const struct posix_acl *acl)
175{
176 const struct posix_acl_entry *pa, *pe;
177 int state = ACL_USER_OBJ;
1da177e4
LT		 178 int needs_mask = 0;
179
180 FOREACH_ACL_ENTRY(pa, acl, pe) {
181 if (pa->e_perm & ~(ACL_READ|ACL_WRITE|ACL_EXECUTE))
182 return -EINVAL;
183 switch (pa->e_tag) {
184 case ACL_USER_OBJ:
185 if (state == ACL_USER_OBJ) {
1da177e4
LT		 186 state = ACL_USER;
187 break;
188 }
189 return -EINVAL;
190
191 case ACL_USER:
192 if (state != ACL_USER)
193 return -EINVAL;
2f6f0654 194 if (!uid_valid(pa->e_uid))
1da177e4 195 return -EINVAL;
1da177e4
LT		 196 needs_mask = 1;
197 break;
198
199 case ACL_GROUP_OBJ:
200 if (state == ACL_USER) {
1da177e4
LT		 201 state = ACL_GROUP;
202 break;
203 }
204 return -EINVAL;
205
206 case ACL_GROUP:
207 if (state != ACL_GROUP)
208 return -EINVAL;
2f6f0654
EB		 209 if (!gid_valid(pa->e_gid))
210 return -EINVAL;
1da177e4
LT		 211 needs_mask = 1;
212 break;
213
214 case ACL_MASK:
215 if (state != ACL_GROUP)
216 return -EINVAL;
217 state = ACL_OTHER;
218 break;
219
220 case ACL_OTHER:
221 if (state == ACL_OTHER ||
222 (state == ACL_GROUP && !needs_mask)) {
223 state = 0;
224 break;
225 }
226 return -EINVAL;
227
228 default:
229 return -EINVAL;
230 }
231 }
232 if (state == 0)
233 return 0;
234 return -EINVAL;
235}
0afaa120 236EXPORT_SYMBOL(posix_acl_valid);
1da177e4
LT		 237
238/*
239 * Returns 0 if the acl can be exactly represented in the traditional
240 * file mode permission bits, or else 1. Returns -E... on error.
241 */
242int
d6952123 243posix_acl_equiv_mode(const struct posix_acl *acl, umode_t *mode_p)
1da177e4
LT		 244{
245 const struct posix_acl_entry *pa, *pe;
d6952123 246 umode_t mode = 0;
1da177e4
LT		 247 int not_equiv = 0;
248
249 FOREACH_ACL_ENTRY(pa, acl, pe) {
250 switch (pa->e_tag) {
251 case ACL_USER_OBJ:
252 mode |= (pa->e_perm & S_IRWXO) << 6;
253 break;
254 case ACL_GROUP_OBJ:
255 mode |= (pa->e_perm & S_IRWXO) << 3;
256 break;
257 case ACL_OTHER:
258 mode |= pa->e_perm & S_IRWXO;
259 break;
260 case ACL_MASK:
261 mode = (mode & ~S_IRWXG) |
262 ((pa->e_perm & S_IRWXO) << 3);
263 not_equiv = 1;
264 break;
265 case ACL_USER:
266 case ACL_GROUP:
267 not_equiv = 1;
268 break;
269 default:
270 return -EINVAL;
271 }
272 }
273 if (mode_p)
274 *mode_p = (*mode_p & ~S_IRWXUGO) | mode;
275 return not_equiv;
276}
0afaa120 277EXPORT_SYMBOL(posix_acl_equiv_mode);
1da177e4
LT		 278
279/*
280 * Create an ACL representing the file mode permission bits of an inode.
281 */
282struct posix_acl *
3a5fba19 283posix_acl_from_mode(umode_t mode, gfp_t flags)
1da177e4
LT		 284{
285 struct posix_acl *acl = posix_acl_alloc(3, flags);
286 if (!acl)
287 return ERR_PTR(-ENOMEM);
288
289 acl->a_entries[0].e_tag = ACL_USER_OBJ;
1da177e4
LT		 290 acl->a_entries[0].e_perm = (mode & S_IRWXU) >> 6;
291
292 acl->a_entries[1].e_tag = ACL_GROUP_OBJ;
1da177e4
LT		 293 acl->a_entries[1].e_perm = (mode & S_IRWXG) >> 3;
294
295 acl->a_entries[2].e_tag = ACL_OTHER;
1da177e4
LT		 296 acl->a_entries[2].e_perm = (mode & S_IRWXO);
297 return acl;
298}
0afaa120 299EXPORT_SYMBOL(posix_acl_from_mode);
1da177e4
LT		 300
301/*
302 * Return 0 if current is granted want access to the inode
303 * by the acl. Returns -E... otherwise.
304 */
305int
306posix_acl_permission(struct inode *inode, const struct posix_acl *acl, int want)
307{
308 const struct posix_acl_entry *pa, *pe, *mask_obj;
309 int found = 0;
310
d124b60a
AG		 311 want &= MAY_READ | MAY_WRITE | MAY_EXEC | MAY_NOT_BLOCK;
312
1da177e4
LT		 313 FOREACH_ACL_ENTRY(pa, acl, pe) {
314 switch(pa->e_tag) {
315 case ACL_USER_OBJ:
316 /* (May have been checked already) */
2f6f0654 317 if (uid_eq(inode->i_uid, current_fsuid()))
1da177e4
LT		 318 goto check_perm;
319 break;
320 case ACL_USER:
2f6f0654 321 if (uid_eq(pa->e_uid, current_fsuid()))
1da177e4
LT		 322 goto mask;
323 break;
324 case ACL_GROUP_OBJ:
325 if (in_group_p(inode->i_gid)) {
326 found = 1;
327 if ((pa->e_perm & want) == want)
328 goto mask;
329 }
330 break;
331 case ACL_GROUP:
2f6f0654 332 if (in_group_p(pa->e_gid)) {
1da177e4
LT		 333 found = 1;
334 if ((pa->e_perm & want) == want)
335 goto mask;
336 }
337 break;
338 case ACL_MASK:
339 break;
340 case ACL_OTHER:
341 if (found)
342 return -EACCES;
343 else
344 goto check_perm;
345 default:
346 return -EIO;
347 }
348 }
349 return -EIO;
350
351mask:
352 for (mask_obj = pa+1; mask_obj != pe; mask_obj++) {
353 if (mask_obj->e_tag == ACL_MASK) {
354 if ((pa->e_perm & mask_obj->e_perm & want) == want)
355 return 0;
356 return -EACCES;
357 }
358 }
359
360check_perm:
361 if ((pa->e_perm & want) == want)
362 return 0;
363 return -EACCES;
364}
365
366/*
367 * Modify acl when creating a new inode. The caller must ensure the acl is
368 * only referenced once.
369 *
370 * mode_p initially must contain the mode parameter to the open() / creat()
371 * system calls. All permissions that are not granted by the acl are removed.
372 * The permissions in the acl are changed to reflect the mode_p parameter.
373 */
d3fb6120 374static int posix_acl_create_masq(struct posix_acl *acl, umode_t *mode_p)
1da177e4
LT		 375{
376 struct posix_acl_entry *pa, *pe;
377 struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
d3fb6120 378 umode_t mode = *mode_p;
1da177e4
LT		 379 int not_equiv = 0;
380
381 /* assert(atomic_read(acl->a_refcount) == 1); */
382
383 FOREACH_ACL_ENTRY(pa, acl, pe) {
384 switch(pa->e_tag) {
385 case ACL_USER_OBJ:
386 pa->e_perm &= (mode >> 6) | ~S_IRWXO;
387 mode &= (pa->e_perm << 6) | ~S_IRWXU;
388 break;
389
390 case ACL_USER:
391 case ACL_GROUP:
392 not_equiv = 1;
393 break;
394
395 case ACL_GROUP_OBJ:
396 group_obj = pa;
397 break;
398
399 case ACL_OTHER:
400 pa->e_perm &= mode | ~S_IRWXO;
401 mode &= pa->e_perm | ~S_IRWXO;
402 break;
403
404 case ACL_MASK:
405 mask_obj = pa;
406 not_equiv = 1;
407 break;
408
409 default:
410 return -EIO;
411 }
412 }
413
414 if (mask_obj) {
415 mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
416 mode &= (mask_obj->e_perm << 3) | ~S_IRWXG;
417 } else {
418 if (!group_obj)
419 return -EIO;
420 group_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
421 mode &= (group_obj->e_perm << 3) | ~S_IRWXG;
422 }
423
424 *mode_p = (*mode_p & ~S_IRWXUGO) | mode;
425 return not_equiv;
426}
427
428/*
429 * Modify the ACL for the chmod syscall.
430 */
5bf3258f 431static int __posix_acl_chmod_masq(struct posix_acl *acl, umode_t mode)
1da177e4
LT		 432{
433 struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
434 struct posix_acl_entry *pa, *pe;
435
436 /* assert(atomic_read(acl->a_refcount) == 1); */
437
438 FOREACH_ACL_ENTRY(pa, acl, pe) {
439 switch(pa->e_tag) {
440 case ACL_USER_OBJ:
441 pa->e_perm = (mode & S_IRWXU) >> 6;
442 break;
443
444 case ACL_USER:
445 case ACL_GROUP:
446 break;
447
448 case ACL_GROUP_OBJ:
449 group_obj = pa;
450 break;
451
452 case ACL_MASK:
453 mask_obj = pa;
454 break;
455
456 case ACL_OTHER:
457 pa->e_perm = (mode & S_IRWXO);
458 break;
459
460 default:
461 return -EIO;
462 }
463 }
464
465 if (mask_obj) {
466 mask_obj->e_perm = (mode & S_IRWXG) >> 3;
467 } else {
468 if (!group_obj)
469 return -EIO;
470 group_obj->e_perm = (mode & S_IRWXG) >> 3;
471 }
472
473 return 0;
474}
bc26ab5f 475
826cae2f 476int
37bc1539 477__posix_acl_create(struct posix_acl **acl, gfp_t gfp, umode_t *mode_p)
826cae2f
AV		 478{
479 struct posix_acl *clone = posix_acl_clone(*acl, gfp);
480 int err = -ENOMEM;
481 if (clone) {
482 err = posix_acl_create_masq(clone, mode_p);
483 if (err < 0) {
484 posix_acl_release(clone);
485 clone = NULL;
486 }
487 }
488 posix_acl_release(*acl);
489 *acl = clone;
490 return err;
491}
37bc1539 492EXPORT_SYMBOL(__posix_acl_create);
826cae2f 493
bc26ab5f 494int
5bf3258f 495__posix_acl_chmod(struct posix_acl **acl, gfp_t gfp, umode_t mode)
bc26ab5f
AV		 496{
497 struct posix_acl *clone = posix_acl_clone(*acl, gfp);
498 int err = -ENOMEM;
499 if (clone) {
5bf3258f 500 err = __posix_acl_chmod_masq(clone, mode);
bc26ab5f
AV		 501 if (err) {
502 posix_acl_release(clone);
503 clone = NULL;
504 }
505 }
506 posix_acl_release(*acl);
507 *acl = clone;
508 return err;
509}
5bf3258f
CH		 510EXPORT_SYMBOL(__posix_acl_chmod);
511
512int
37bc1539 513posix_acl_chmod(struct inode *inode, umode_t mode)
5bf3258f
CH		 514{
515 struct posix_acl *acl;
516 int ret = 0;
517
518 if (!IS_POSIXACL(inode))
519 return 0;
520 if (!inode->i_op->set_acl)
521 return -EOPNOTSUPP;
522
523 acl = get_acl(inode, ACL_TYPE_ACCESS);
524 if (IS_ERR_OR_NULL(acl))
525 return PTR_ERR(acl);
526
37bc1539 527 ret = __posix_acl_chmod(&acl, GFP_KERNEL, mode);
5bf3258f
CH		 528 if (ret)
529 return ret;
530 ret = inode->i_op->set_acl(inode, acl, ACL_TYPE_ACCESS);
531 posix_acl_release(acl);
532 return ret;
533}
bc26ab5f 534EXPORT_SYMBOL(posix_acl_chmod);
5c8ebd57 535
37bc1539
CH		 536int
537posix_acl_create(struct inode *dir, umode_t *mode,
538 struct posix_acl **default_acl, struct posix_acl **acl)
539{
540 struct posix_acl *p;
541 int ret;
542
543 if (S_ISLNK(*mode) || !IS_POSIXACL(dir))
544 goto no_acl;
545
546 p = get_acl(dir, ACL_TYPE_DEFAULT);
547 if (IS_ERR(p))
548 return PTR_ERR(p);
549
550 if (!p) {
551 *mode &= ~current_umask();
552 goto no_acl;
553 }
554
555 *acl = posix_acl_clone(p, GFP_NOFS);
556 if (!*acl)
557 return -ENOMEM;
558
559 ret = posix_acl_create_masq(*acl, mode);
560 if (ret < 0) {
561 posix_acl_release(*acl);
562 return -ENOMEM;
563 }
564
565 if (ret == 0) {
566 posix_acl_release(*acl);
567 *acl = NULL;
568 }
569
570 if (!S_ISDIR(*mode)) {
571 posix_acl_release(p);
572 *default_acl = NULL;
573 } else {
574 *default_acl = p;
575 }
576 return 0;
577
578no_acl:
579 *default_acl = NULL;
580 *acl = NULL;
581 return 0;
582}
583EXPORT_SYMBOL_GPL(posix_acl_create);
584
5c8ebd57
CH		 585/*
586 * Fix up the uids and gids in posix acl extended attributes in place.
587 */
588static void posix_acl_fix_xattr_userns(
589 struct user_namespace *to, struct user_namespace *from,
590 void *value, size_t size)
591{
592 posix_acl_xattr_header *header = (posix_acl_xattr_header *)value;
593 posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end;
594 int count;
595 kuid_t uid;
596 kgid_t gid;
597
598 if (!value)
599 return;
600 if (size < sizeof(posix_acl_xattr_header))
601 return;
602 if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
603 return;
604
605 count = posix_acl_xattr_count(size);
606 if (count < 0)
607 return;
608 if (count == 0)
609 return;
610
611 for (end = entry + count; entry != end; entry++) {
612 switch(le16_to_cpu(entry->e_tag)) {
613 case ACL_USER:
614 uid = make_kuid(from, le32_to_cpu(entry->e_id));
615 entry->e_id = cpu_to_le32(from_kuid(to, uid));
616 break;
617 case ACL_GROUP:
618 gid = make_kgid(from, le32_to_cpu(entry->e_id));
619 entry->e_id = cpu_to_le32(from_kgid(to, gid));
620 break;
621 default:
622 break;
623 }
624 }
625}
626
627void posix_acl_fix_xattr_from_user(void *value, size_t size)
628{
629 struct user_namespace *user_ns = current_user_ns();
630 if (user_ns == &init_user_ns)
631 return;
632 posix_acl_fix_xattr_userns(&init_user_ns, user_ns, value, size);
633}
634
635void posix_acl_fix_xattr_to_user(void *value, size_t size)
636{
637 struct user_namespace *user_ns = current_user_ns();
638 if (user_ns == &init_user_ns)
639 return;
640 posix_acl_fix_xattr_userns(user_ns, &init_user_ns, value, size);
641}
642
643/*
644 * Convert from extended attribute to in-memory representation.
645 */
646struct posix_acl *
647posix_acl_from_xattr(struct user_namespace *user_ns,
648 const void *value, size_t size)
649{
650 posix_acl_xattr_header *header = (posix_acl_xattr_header *)value;
651 posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end;
652 int count;
653 struct posix_acl *acl;
654 struct posix_acl_entry *acl_e;
655
656 if (!value)
657 return NULL;
658 if (size < sizeof(posix_acl_xattr_header))
659 return ERR_PTR(-EINVAL);
660 if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
661 return ERR_PTR(-EOPNOTSUPP);
662
663 count = posix_acl_xattr_count(size);
664 if (count < 0)
665 return ERR_PTR(-EINVAL);
666 if (count == 0)
667 return NULL;
668
669 acl = posix_acl_alloc(count, GFP_NOFS);
670 if (!acl)
671 return ERR_PTR(-ENOMEM);
672 acl_e = acl->a_entries;
673
674 for (end = entry + count; entry != end; acl_e++, entry++) {
675 acl_e->e_tag = le16_to_cpu(entry->e_tag);
676 acl_e->e_perm = le16_to_cpu(entry->e_perm);
677
678 switch(acl_e->e_tag) {
679 case ACL_USER_OBJ:
680 case ACL_GROUP_OBJ:
681 case ACL_MASK:
682 case ACL_OTHER:
683 break;
684
685 case ACL_USER:
686 acl_e->e_uid =
687 make_kuid(user_ns,
688 le32_to_cpu(entry->e_id));
689 if (!uid_valid(acl_e->e_uid))
690 goto fail;
691 break;
692 case ACL_GROUP:
693 acl_e->e_gid =
694 make_kgid(user_ns,
695 le32_to_cpu(entry->e_id));
696 if (!gid_valid(acl_e->e_gid))
697 goto fail;
698 break;
699
700 default:
701 goto fail;
702 }
703 }
704 return acl;
705
706fail:
707 posix_acl_release(acl);
708 return ERR_PTR(-EINVAL);
709}
710EXPORT_SYMBOL (posix_acl_from_xattr);
711
712/*
713 * Convert from in-memory to extended attribute representation.
714 */
715int
716posix_acl_to_xattr(struct user_namespace *user_ns, const struct posix_acl *acl,
717 void *buffer, size_t size)
718{
719 posix_acl_xattr_header *ext_acl = (posix_acl_xattr_header *)buffer;
720 posix_acl_xattr_entry *ext_entry = ext_acl->a_entries;
721 int real_size, n;
722
723 real_size = posix_acl_xattr_size(acl->a_count);
724 if (!buffer)
725 return real_size;
726 if (real_size > size)
727 return -ERANGE;
728
729 ext_acl->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION);
730
731 for (n=0; n < acl->a_count; n++, ext_entry++) {
732 const struct posix_acl_entry *acl_e = &acl->a_entries[n];
733 ext_entry->e_tag = cpu_to_le16(acl_e->e_tag);
734 ext_entry->e_perm = cpu_to_le16(acl_e->e_perm);
735 switch(acl_e->e_tag) {
736 case ACL_USER:
737 ext_entry->e_id =
738 cpu_to_le32(from_kuid(user_ns, acl_e->e_uid));
739 break;
740 case ACL_GROUP:
741 ext_entry->e_id =
742 cpu_to_le32(from_kgid(user_ns, acl_e->e_gid));
743 break;
744 default:
745 ext_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
746 break;
747 }
748 }
749 return real_size;
750}
751EXPORT_SYMBOL (posix_acl_to_xattr);
2aeccbe9
CH		 752
753static int
754posix_acl_xattr_get(struct dentry *dentry, const char *name,
755 void *value, size_t size, int type)
756{
757 struct posix_acl *acl;
758 int error;
759
760 if (!IS_POSIXACL(dentry->d_inode))
761 return -EOPNOTSUPP;
762 if (S_ISLNK(dentry->d_inode->i_mode))
763 return -EOPNOTSUPP;
764
765 acl = get_acl(dentry->d_inode, type);
766 if (IS_ERR(acl))
767 return PTR_ERR(acl);
768 if (acl == NULL)
769 return -ENODATA;
770
771 error = posix_acl_to_xattr(&init_user_ns, acl, value, size);
772 posix_acl_release(acl);
773
774 return error;
775}
776
777static int
778posix_acl_xattr_set(struct dentry *dentry, const char *name,
779 const void *value, size_t size, int flags, int type)
780{
781 struct inode *inode = dentry->d_inode;
782 struct posix_acl *acl = NULL;
783 int ret;
784
785 if (!IS_POSIXACL(inode))
786 return -EOPNOTSUPP;
787 if (!inode->i_op->set_acl)
788 return -EOPNOTSUPP;
789
790 if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
791 return value ? -EACCES : 0;
792 if (!inode_owner_or_capable(inode))
793 return -EPERM;
794
795 if (value) {
796 acl = posix_acl_from_xattr(&init_user_ns, value, size);
797 if (IS_ERR(acl))
798 return PTR_ERR(acl);
799
800 if (acl) {
801 ret = posix_acl_valid(acl);
802 if (ret)
803 goto out;
804 }
805 }
806
807 ret = inode->i_op->set_acl(inode, acl, type);
808out:
809 posix_acl_release(acl);
810 return ret;
811}
812
813static size_t
814posix_acl_xattr_list(struct dentry *dentry, char *list, size_t list_size,
815 const char *name, size_t name_len, int type)
816{
817 const char *xname;
818 size_t size;
819
820 if (!IS_POSIXACL(dentry->d_inode))
821 return -EOPNOTSUPP;
822 if (S_ISLNK(dentry->d_inode->i_mode))
823 return -EOPNOTSUPP;
824
825 if (type == ACL_TYPE_ACCESS)
826 xname = POSIX_ACL_XATTR_ACCESS;
827 else
828 xname = POSIX_ACL_XATTR_DEFAULT;
829
830 size = strlen(xname) + 1;
831 if (list && size <= list_size)
832 memcpy(list, xname, size);
833 return size;
834}
835
836const struct xattr_handler posix_acl_access_xattr_handler = {
837 .prefix = POSIX_ACL_XATTR_ACCESS,
838 .flags = ACL_TYPE_ACCESS,
839 .list = posix_acl_xattr_list,
840 .get = posix_acl_xattr_get,
841 .set = posix_acl_xattr_set,
842};
843EXPORT_SYMBOL_GPL(posix_acl_access_xattr_handler);
844
845const struct xattr_handler posix_acl_default_xattr_handler = {
846 .prefix = POSIX_ACL_XATTR_DEFAULT,
847 .flags = ACL_TYPE_DEFAULT,
848 .list = posix_acl_xattr_list,
849 .get = posix_acl_xattr_get,
850 .set = posix_acl_xattr_set,
851};
852EXPORT_SYMBOL_GPL(posix_acl_default_xattr_handler);
feda821e
CH		 853
854int simple_set_acl(struct inode *inode, struct posix_acl *acl, int type)
855{
856 int error;
857
858 if (type == ACL_TYPE_ACCESS) {
859 error = posix_acl_equiv_mode(acl, &inode->i_mode);
860 if (error < 0)
861 return 0;
862 if (error == 0)
863 acl = NULL;
864 }
865
866 inode->i_ctime = CURRENT_TIME;
867 set_cached_acl(inode, type, acl);
868 return 0;
869}
870
871int simple_acl_create(struct inode *dir, struct inode *inode)
872{
873 struct posix_acl *default_acl, *acl;
874 int error;
875
876 error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
877 if (error)
878 return error;
879
880 set_cached_acl(inode, ACL_TYPE_DEFAULT, default_acl);
881 set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
882
883 if (default_acl)
884 posix_acl_release(default_acl);
885 if (acl)
886 posix_acl_release(acl);
887 return 0;
888}
Linux 6.x block layer and io_uring tree(s)