Merge branch 'upstream'
[deliverable/linux.git] / fs / reiserfs / xattr_acl.c
CommitLineData
16f7e0fe 1#include <linux/capability.h>
1da177e4
LT
2#include <linux/fs.h>
3#include <linux/posix_acl.h>
4#include <linux/reiserfs_fs.h>
5#include <linux/errno.h>
6#include <linux/pagemap.h>
7#include <linux/xattr.h>
9a59f452 8#include <linux/posix_acl_xattr.h>
1da177e4
LT
9#include <linux/reiserfs_xattr.h>
10#include <linux/reiserfs_acl.h>
11#include <asm/uaccess.h>
12
bd4c625c
LT
13static int reiserfs_set_acl(struct inode *inode, int type,
14 struct posix_acl *acl);
1da177e4
LT
15
16static int
17xattr_set_acl(struct inode *inode, int type, const void *value, size_t size)
18{
19 struct posix_acl *acl;
20 int error;
21
22 if (!reiserfs_posixacl(inode->i_sb))
23 return -EOPNOTSUPP;
24 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
25 return -EPERM;
26
27 if (value) {
28 acl = posix_acl_from_xattr(value, size);
29 if (IS_ERR(acl)) {
30 return PTR_ERR(acl);
31 } else if (acl) {
32 error = posix_acl_valid(acl);
33 if (error)
34 goto release_and_out;
35 }
36 } else
37 acl = NULL;
38
bd4c625c 39 error = reiserfs_set_acl(inode, type, acl);
1da177e4 40
bd4c625c 41 release_and_out:
1da177e4
LT
42 posix_acl_release(acl);
43 return error;
44}
45
1da177e4
LT
46static int
47xattr_get_acl(struct inode *inode, int type, void *buffer, size_t size)
48{
49 struct posix_acl *acl;
50 int error;
51
52 if (!reiserfs_posixacl(inode->i_sb))
53 return -EOPNOTSUPP;
54
bd4c625c 55 acl = reiserfs_get_acl(inode, type);
1da177e4
LT
56 if (IS_ERR(acl))
57 return PTR_ERR(acl);
58 if (acl == NULL)
59 return -ENODATA;
60 error = posix_acl_to_xattr(acl, buffer, size);
61 posix_acl_release(acl);
62
63 return error;
64}
65
1da177e4
LT
66/*
67 * Convert from filesystem to in-memory representation.
68 */
bd4c625c 69static struct posix_acl *posix_acl_from_disk(const void *value, size_t size)
1da177e4
LT
70{
71 const char *end = (char *)value + size;
72 int n, count;
73 struct posix_acl *acl;
74
75 if (!value)
76 return NULL;
77 if (size < sizeof(reiserfs_acl_header))
bd4c625c
LT
78 return ERR_PTR(-EINVAL);
79 if (((reiserfs_acl_header *) value)->a_version !=
1da177e4
LT
80 cpu_to_le32(REISERFS_ACL_VERSION))
81 return ERR_PTR(-EINVAL);
82 value = (char *)value + sizeof(reiserfs_acl_header);
83 count = reiserfs_acl_count(size);
84 if (count < 0)
85 return ERR_PTR(-EINVAL);
86 if (count == 0)
87 return NULL;
88 acl = posix_acl_alloc(count, GFP_NOFS);
89 if (!acl)
90 return ERR_PTR(-ENOMEM);
bd4c625c
LT
91 for (n = 0; n < count; n++) {
92 reiserfs_acl_entry *entry = (reiserfs_acl_entry *) value;
1da177e4
LT
93 if ((char *)value + sizeof(reiserfs_acl_entry_short) > end)
94 goto fail;
bd4c625c 95 acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
1da177e4 96 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
bd4c625c
LT
97 switch (acl->a_entries[n].e_tag) {
98 case ACL_USER_OBJ:
99 case ACL_GROUP_OBJ:
100 case ACL_MASK:
101 case ACL_OTHER:
102 value = (char *)value +
103 sizeof(reiserfs_acl_entry_short);
104 acl->a_entries[n].e_id = ACL_UNDEFINED_ID;
105 break;
106
107 case ACL_USER:
108 case ACL_GROUP:
109 value = (char *)value + sizeof(reiserfs_acl_entry);
110 if ((char *)value > end)
1da177e4 111 goto fail;
bd4c625c
LT
112 acl->a_entries[n].e_id = le32_to_cpu(entry->e_id);
113 break;
114
115 default:
116 goto fail;
1da177e4
LT
117 }
118 }
119 if (value != end)
120 goto fail;
121 return acl;
122
bd4c625c 123 fail:
1da177e4
LT
124 posix_acl_release(acl);
125 return ERR_PTR(-EINVAL);
126}
127
128/*
129 * Convert from in-memory to filesystem representation.
130 */
bd4c625c 131static void *posix_acl_to_disk(const struct posix_acl *acl, size_t * size)
1da177e4
LT
132{
133 reiserfs_acl_header *ext_acl;
134 char *e;
135 int n;
136
137 *size = reiserfs_acl_size(acl->a_count);
bd4c625c
LT
138 ext_acl = (reiserfs_acl_header *) kmalloc(sizeof(reiserfs_acl_header) +
139 acl->a_count *
140 sizeof(reiserfs_acl_entry),
141 GFP_NOFS);
1da177e4
LT
142 if (!ext_acl)
143 return ERR_PTR(-ENOMEM);
144 ext_acl->a_version = cpu_to_le32(REISERFS_ACL_VERSION);
145 e = (char *)ext_acl + sizeof(reiserfs_acl_header);
bd4c625c
LT
146 for (n = 0; n < acl->a_count; n++) {
147 reiserfs_acl_entry *entry = (reiserfs_acl_entry *) e;
148 entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
1da177e4 149 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
bd4c625c
LT
150 switch (acl->a_entries[n].e_tag) {
151 case ACL_USER:
152 case ACL_GROUP:
153 entry->e_id = cpu_to_le32(acl->a_entries[n].e_id);
154 e += sizeof(reiserfs_acl_entry);
155 break;
156
157 case ACL_USER_OBJ:
158 case ACL_GROUP_OBJ:
159 case ACL_MASK:
160 case ACL_OTHER:
161 e += sizeof(reiserfs_acl_entry_short);
162 break;
163
164 default:
165 goto fail;
1da177e4
LT
166 }
167 }
168 return (char *)ext_acl;
169
bd4c625c 170 fail:
1da177e4
LT
171 kfree(ext_acl);
172 return ERR_PTR(-EINVAL);
173}
174
175/*
176 * Inode operation get_posix_acl().
177 *
1b1dcc1b 178 * inode->i_mutex: down
1da177e4
LT
179 * BKL held [before 2.5.x]
180 */
bd4c625c 181struct posix_acl *reiserfs_get_acl(struct inode *inode, int type)
1da177e4
LT
182{
183 char *name, *value;
184 struct posix_acl *acl, **p_acl;
185 size_t size;
186 int retval;
bd4c625c
LT
187 struct reiserfs_inode_info *reiserfs_i = REISERFS_I(inode);
188
189 switch (type) {
190 case ACL_TYPE_ACCESS:
191 name = POSIX_ACL_XATTR_ACCESS;
192 p_acl = &reiserfs_i->i_acl_access;
193 break;
194 case ACL_TYPE_DEFAULT:
195 name = POSIX_ACL_XATTR_DEFAULT;
196 p_acl = &reiserfs_i->i_acl_default;
197 break;
198 default:
199 return ERR_PTR(-EINVAL);
200 }
201
202 if (IS_ERR(*p_acl)) {
203 if (PTR_ERR(*p_acl) == -ENODATA)
204 return NULL;
205 } else if (*p_acl != NULL)
206 return posix_acl_dup(*p_acl);
207
208 size = reiserfs_xattr_get(inode, name, NULL, 0);
209 if ((int)size < 0) {
210 if (size == -ENODATA || size == -ENOSYS) {
211 *p_acl = ERR_PTR(-ENODATA);
212 return NULL;
213 }
214 return ERR_PTR(size);
215 }
1da177e4 216
bd4c625c
LT
217 value = kmalloc(size, GFP_NOFS);
218 if (!value)
219 return ERR_PTR(-ENOMEM);
1da177e4
LT
220
221 retval = reiserfs_xattr_get(inode, name, value, size);
222 if (retval == -ENODATA || retval == -ENOSYS) {
223 /* This shouldn't actually happen as it should have
224 been caught above.. but just in case */
225 acl = NULL;
bd4c625c
LT
226 *p_acl = ERR_PTR(-ENODATA);
227 } else if (retval < 0) {
1da177e4
LT
228 acl = ERR_PTR(retval);
229 } else {
230 acl = posix_acl_from_disk(value, retval);
90947ef2
JM
231 if (!IS_ERR(acl))
232 *p_acl = posix_acl_dup(acl);
bd4c625c 233 }
1da177e4
LT
234
235 kfree(value);
236 return acl;
237}
238
239/*
240 * Inode operation set_posix_acl().
241 *
1b1dcc1b 242 * inode->i_mutex: down
1da177e4
LT
243 * BKL held [before 2.5.x]
244 */
245static int
246reiserfs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
247{
bd4c625c 248 char *name;
1da177e4
LT
249 void *value = NULL;
250 struct posix_acl **p_acl;
251 size_t size;
252 int error;
bd4c625c 253 struct reiserfs_inode_info *reiserfs_i = REISERFS_I(inode);
1da177e4
LT
254
255 if (S_ISLNK(inode->i_mode))
256 return -EOPNOTSUPP;
257
bd4c625c
LT
258 switch (type) {
259 case ACL_TYPE_ACCESS:
260 name = POSIX_ACL_XATTR_ACCESS;
261 p_acl = &reiserfs_i->i_acl_access;
262 if (acl) {
263 mode_t mode = inode->i_mode;
264 error = posix_acl_equiv_mode(acl, &mode);
265 if (error < 0)
266 return error;
267 else {
268 inode->i_mode = mode;
269 if (error == 0)
270 acl = NULL;
271 }
272 }
273 break;
274 case ACL_TYPE_DEFAULT:
275 name = POSIX_ACL_XATTR_DEFAULT;
276 p_acl = &reiserfs_i->i_acl_default;
277 if (!S_ISDIR(inode->i_mode))
278 return acl ? -EACCES : 0;
279 break;
280 default:
281 return -EINVAL;
282 }
283
284 if (acl) {
285 value = posix_acl_to_disk(acl, &size);
286 if (IS_ERR(value))
287 return (int)PTR_ERR(value);
288 error = reiserfs_xattr_set(inode, name, value, size, 0);
1da177e4 289 } else {
bd4c625c
LT
290 error = reiserfs_xattr_del(inode, name);
291 if (error == -ENODATA) {
292 /* This may seem odd here, but it means that the ACL was set
293 * with a value representable with mode bits. If there was
294 * an ACL before, reiserfs_xattr_del already dirtied the inode.
295 */
296 mark_inode_dirty(inode);
297 error = 0;
298 }
299 }
1da177e4 300
833d304b 301 kfree(value);
1da177e4 302
bd4c625c
LT
303 if (!error) {
304 /* Release the old one */
305 if (!IS_ERR(*p_acl) && *p_acl)
306 posix_acl_release(*p_acl);
1da177e4 307
bd4c625c
LT
308 if (acl == NULL)
309 *p_acl = ERR_PTR(-ENODATA);
310 else
311 *p_acl = posix_acl_dup(acl);
312 }
1da177e4
LT
313
314 return error;
315}
316
1b1dcc1b 317/* dir->i_mutex: locked,
1da177e4
LT
318 * inode is new and not released into the wild yet */
319int
bd4c625c
LT
320reiserfs_inherit_default_acl(struct inode *dir, struct dentry *dentry,
321 struct inode *inode)
1da177e4 322{
bd4c625c
LT
323 struct posix_acl *acl;
324 int err = 0;
325
326 /* ACLs only get applied to files and directories */
327 if (S_ISLNK(inode->i_mode))
328 return 0;
329
330 /* ACLs can only be used on "new" objects, so if it's an old object
331 * there is nothing to inherit from */
332 if (get_inode_sd_version(dir) == STAT_DATA_V1)
333 goto apply_umask;
334
335 /* Don't apply ACLs to objects in the .reiserfs_priv tree.. This
336 * would be useless since permissions are ignored, and a pain because
337 * it introduces locking cycles */
338 if (is_reiserfs_priv_object(dir)) {
339 reiserfs_mark_inode_private(inode);
340 goto apply_umask;
341 }
342
343 acl = reiserfs_get_acl(dir, ACL_TYPE_DEFAULT);
344 if (IS_ERR(acl)) {
345 if (PTR_ERR(acl) == -ENODATA)
346 goto apply_umask;
347 return PTR_ERR(acl);
348 }
349
350 if (acl) {
351 struct posix_acl *acl_copy;
352 mode_t mode = inode->i_mode;
353 int need_acl;
354
355 /* Copy the default ACL to the default ACL of a new directory */
356 if (S_ISDIR(inode->i_mode)) {
357 err = reiserfs_set_acl(inode, ACL_TYPE_DEFAULT, acl);
358 if (err)
359 goto cleanup;
360 }
361
362 /* Now we reconcile the new ACL and the mode,
363 potentially modifying both */
364 acl_copy = posix_acl_clone(acl, GFP_NOFS);
365 if (!acl_copy) {
366 err = -ENOMEM;
367 goto cleanup;
368 }
369
370 need_acl = posix_acl_create_masq(acl_copy, &mode);
371 if (need_acl >= 0) {
372 if (mode != inode->i_mode) {
373 inode->i_mode = mode;
374 }
375
376 /* If we need an ACL.. */
377 if (need_acl > 0) {
378 err =
379 reiserfs_set_acl(inode, ACL_TYPE_ACCESS,
380 acl_copy);
381 if (err)
382 goto cleanup_copy;
383 }
384 }
385 cleanup_copy:
386 posix_acl_release(acl_copy);
387 cleanup:
388 posix_acl_release(acl);
389 } else {
390 apply_umask:
391 /* no ACL, apply umask */
392 inode->i_mode &= ~current->fs->umask;
393 }
394
395 return err;
1da177e4
LT
396}
397
398/* Looks up and caches the result of the default ACL.
399 * We do this so that we don't need to carry the xattr_sem into
400 * reiserfs_new_inode if we don't need to */
bd4c625c 401int reiserfs_cache_default_acl(struct inode *inode)
1da177e4 402{
bd4c625c
LT
403 int ret = 0;
404 if (reiserfs_posixacl(inode->i_sb) && !is_reiserfs_priv_object(inode)) {
405 struct posix_acl *acl;
406 reiserfs_read_lock_xattr_i(inode);
407 reiserfs_read_lock_xattrs(inode->i_sb);
408 acl = reiserfs_get_acl(inode, ACL_TYPE_DEFAULT);
409 reiserfs_read_unlock_xattrs(inode->i_sb);
410 reiserfs_read_unlock_xattr_i(inode);
411 ret = acl ? 1 : 0;
412 posix_acl_release(acl);
413 }
414
415 return ret;
1da177e4
LT
416}
417
bd4c625c 418int reiserfs_acl_chmod(struct inode *inode)
1da177e4 419{
bd4c625c
LT
420 struct posix_acl *acl, *clone;
421 int error;
1da177e4 422
bd4c625c
LT
423 if (S_ISLNK(inode->i_mode))
424 return -EOPNOTSUPP;
1da177e4 425
bd4c625c
LT
426 if (get_inode_sd_version(inode) == STAT_DATA_V1 ||
427 !reiserfs_posixacl(inode->i_sb)) {
428 return 0;
1da177e4
LT
429 }
430
bd4c625c
LT
431 reiserfs_read_lock_xattrs(inode->i_sb);
432 acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
433 reiserfs_read_unlock_xattrs(inode->i_sb);
434 if (!acl)
435 return 0;
436 if (IS_ERR(acl))
437 return PTR_ERR(acl);
438 clone = posix_acl_clone(acl, GFP_NOFS);
439 posix_acl_release(acl);
440 if (!clone)
441 return -ENOMEM;
442 error = posix_acl_chmod_masq(clone, inode->i_mode);
443 if (!error) {
444 int lock = !has_xattr_dir(inode);
445 reiserfs_write_lock_xattr_i(inode);
446 if (lock)
447 reiserfs_write_lock_xattrs(inode->i_sb);
448 else
449 reiserfs_read_lock_xattrs(inode->i_sb);
450 error = reiserfs_set_acl(inode, ACL_TYPE_ACCESS, clone);
451 if (lock)
452 reiserfs_write_unlock_xattrs(inode->i_sb);
453 else
454 reiserfs_read_unlock_xattrs(inode->i_sb);
455 reiserfs_write_unlock_xattr_i(inode);
456 }
457 posix_acl_release(clone);
458 return error;
1da177e4
LT
459}
460
461static int
462posix_acl_access_get(struct inode *inode, const char *name,
bd4c625c 463 void *buffer, size_t size)
1da177e4 464{
bd4c625c 465 if (strlen(name) != sizeof(POSIX_ACL_XATTR_ACCESS) - 1)
1da177e4
LT
466 return -EINVAL;
467 return xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size);
468}
469
470static int
471posix_acl_access_set(struct inode *inode, const char *name,
bd4c625c 472 const void *value, size_t size, int flags)
1da177e4 473{
bd4c625c 474 if (strlen(name) != sizeof(POSIX_ACL_XATTR_ACCESS) - 1)
1da177e4
LT
475 return -EINVAL;
476 return xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
477}
478
bd4c625c 479static int posix_acl_access_del(struct inode *inode, const char *name)
1da177e4 480{
bd4c625c
LT
481 struct reiserfs_inode_info *reiserfs_i = REISERFS_I(inode);
482 struct posix_acl **acl = &reiserfs_i->i_acl_access;
483 if (strlen(name) != sizeof(POSIX_ACL_XATTR_ACCESS) - 1)
484 return -EINVAL;
485 if (!IS_ERR(*acl) && *acl) {
486 posix_acl_release(*acl);
487 *acl = ERR_PTR(-ENODATA);
488 }
489
490 return 0;
1da177e4
LT
491}
492
493static int
bd4c625c
LT
494posix_acl_access_list(struct inode *inode, const char *name, int namelen,
495 char *out)
1da177e4 496{
bd4c625c
LT
497 int len = namelen;
498 if (!reiserfs_posixacl(inode->i_sb))
499 return 0;
500 if (out)
501 memcpy(out, name, len);
1da177e4 502
bd4c625c 503 return len;
1da177e4
LT
504}
505
506struct reiserfs_xattr_handler posix_acl_access_handler = {
9a59f452 507 .prefix = POSIX_ACL_XATTR_ACCESS,
1da177e4
LT
508 .get = posix_acl_access_get,
509 .set = posix_acl_access_set,
510 .del = posix_acl_access_del,
511 .list = posix_acl_access_list,
512};
513
514static int
bd4c625c
LT
515posix_acl_default_get(struct inode *inode, const char *name,
516 void *buffer, size_t size)
1da177e4 517{
bd4c625c 518 if (strlen(name) != sizeof(POSIX_ACL_XATTR_DEFAULT) - 1)
1da177e4
LT
519 return -EINVAL;
520 return xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size);
521}
522
523static int
524posix_acl_default_set(struct inode *inode, const char *name,
bd4c625c 525 const void *value, size_t size, int flags)
1da177e4 526{
bd4c625c 527 if (strlen(name) != sizeof(POSIX_ACL_XATTR_DEFAULT) - 1)
1da177e4
LT
528 return -EINVAL;
529 return xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
530}
531
bd4c625c 532static int posix_acl_default_del(struct inode *inode, const char *name)
1da177e4 533{
bd4c625c
LT
534 struct reiserfs_inode_info *reiserfs_i = REISERFS_I(inode);
535 struct posix_acl **acl = &reiserfs_i->i_acl_default;
536 if (strlen(name) != sizeof(POSIX_ACL_XATTR_DEFAULT) - 1)
537 return -EINVAL;
538 if (!IS_ERR(*acl) && *acl) {
539 posix_acl_release(*acl);
540 *acl = ERR_PTR(-ENODATA);
541 }
542
543 return 0;
1da177e4
LT
544}
545
546static int
bd4c625c
LT
547posix_acl_default_list(struct inode *inode, const char *name, int namelen,
548 char *out)
1da177e4 549{
bd4c625c
LT
550 int len = namelen;
551 if (!reiserfs_posixacl(inode->i_sb))
552 return 0;
553 if (out)
554 memcpy(out, name, len);
1da177e4 555
bd4c625c 556 return len;
1da177e4
LT
557}
558
559struct reiserfs_xattr_handler posix_acl_default_handler = {
9a59f452 560 .prefix = POSIX_ACL_XATTR_DEFAULT,
1da177e4
LT
561 .get = posix_acl_default_get,
562 .set = posix_acl_default_set,
563 .del = posix_acl_default_del,
564 .list = posix_acl_default_list,
565};
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