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[PATCH] mutex subsystem, semaphore to mutex: XFS
[net-next-2.6.git] / fs / reiserfs / xattr_acl.c
CommitLineData
1da177e4
LT
1#include <linux/fs.h>
2#include <linux/posix_acl.h>
3#include <linux/reiserfs_fs.h>
4#include <linux/errno.h>
5#include <linux/pagemap.h>
6#include <linux/xattr.h>
9a59f452 7#include <linux/posix_acl_xattr.h>
1da177e4
LT
8#include <linux/reiserfs_xattr.h>
9#include <linux/reiserfs_acl.h>
10#include <asm/uaccess.h>
11
bd4c625c
LT
12static int reiserfs_set_acl(struct inode *inode, int type,
13 struct posix_acl *acl);
1da177e4
LT
14
15static int
16xattr_set_acl(struct inode *inode, int type, const void *value, size_t size)
17{
18 struct posix_acl *acl;
19 int error;
20
21 if (!reiserfs_posixacl(inode->i_sb))
22 return -EOPNOTSUPP;
23 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
24 return -EPERM;
25
26 if (value) {
27 acl = posix_acl_from_xattr(value, size);
28 if (IS_ERR(acl)) {
29 return PTR_ERR(acl);
30 } else if (acl) {
31 error = posix_acl_valid(acl);
32 if (error)
33 goto release_and_out;
34 }
35 } else
36 acl = NULL;
37
bd4c625c 38 error = reiserfs_set_acl(inode, type, acl);
1da177e4 39
bd4c625c 40 release_and_out:
1da177e4
LT
41 posix_acl_release(acl);
42 return error;
43}
44
1da177e4
LT
45static int
46xattr_get_acl(struct inode *inode, int type, void *buffer, size_t size)
47{
48 struct posix_acl *acl;
49 int error;
50
51 if (!reiserfs_posixacl(inode->i_sb))
52 return -EOPNOTSUPP;
53
bd4c625c 54 acl = reiserfs_get_acl(inode, type);
1da177e4
LT
55 if (IS_ERR(acl))
56 return PTR_ERR(acl);
57 if (acl == NULL)
58 return -ENODATA;
59 error = posix_acl_to_xattr(acl, buffer, size);
60 posix_acl_release(acl);
61
62 return error;
63}
64
1da177e4
LT
65/*
66 * Convert from filesystem to in-memory representation.
67 */
bd4c625c 68static struct posix_acl *posix_acl_from_disk(const void *value, size_t size)
1da177e4
LT
69{
70 const char *end = (char *)value + size;
71 int n, count;
72 struct posix_acl *acl;
73
74 if (!value)
75 return NULL;
76 if (size < sizeof(reiserfs_acl_header))
bd4c625c
LT
77 return ERR_PTR(-EINVAL);
78 if (((reiserfs_acl_header *) value)->a_version !=
1da177e4
LT
79 cpu_to_le32(REISERFS_ACL_VERSION))
80 return ERR_PTR(-EINVAL);
81 value = (char *)value + sizeof(reiserfs_acl_header);
82 count = reiserfs_acl_count(size);
83 if (count < 0)
84 return ERR_PTR(-EINVAL);
85 if (count == 0)
86 return NULL;
87 acl = posix_acl_alloc(count, GFP_NOFS);
88 if (!acl)
89 return ERR_PTR(-ENOMEM);
bd4c625c
LT
90 for (n = 0; n < count; n++) {
91 reiserfs_acl_entry *entry = (reiserfs_acl_entry *) value;
1da177e4
LT
92 if ((char *)value + sizeof(reiserfs_acl_entry_short) > end)
93 goto fail;
bd4c625c 94 acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
1da177e4 95 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
bd4c625c
LT
96 switch (acl->a_entries[n].e_tag) {
97 case ACL_USER_OBJ:
98 case ACL_GROUP_OBJ:
99 case ACL_MASK:
100 case ACL_OTHER:
101 value = (char *)value +
102 sizeof(reiserfs_acl_entry_short);
103 acl->a_entries[n].e_id = ACL_UNDEFINED_ID;
104 break;
105
106 case ACL_USER:
107 case ACL_GROUP:
108 value = (char *)value + sizeof(reiserfs_acl_entry);
109 if ((char *)value > end)
1da177e4 110 goto fail;
bd4c625c
LT
111 acl->a_entries[n].e_id = le32_to_cpu(entry->e_id);
112 break;
113
114 default:
115 goto fail;
1da177e4
LT
116 }
117 }
118 if (value != end)
119 goto fail;
120 return acl;
121
bd4c625c 122 fail:
1da177e4
LT
123 posix_acl_release(acl);
124 return ERR_PTR(-EINVAL);
125}
126
127/*
128 * Convert from in-memory to filesystem representation.
129 */
bd4c625c 130static void *posix_acl_to_disk(const struct posix_acl *acl, size_t * size)
1da177e4
LT
131{
132 reiserfs_acl_header *ext_acl;
133 char *e;
134 int n;
135
136 *size = reiserfs_acl_size(acl->a_count);
bd4c625c
LT
137 ext_acl = (reiserfs_acl_header *) kmalloc(sizeof(reiserfs_acl_header) +
138 acl->a_count *
139 sizeof(reiserfs_acl_entry),
140 GFP_NOFS);
1da177e4
LT
141 if (!ext_acl)
142 return ERR_PTR(-ENOMEM);
143 ext_acl->a_version = cpu_to_le32(REISERFS_ACL_VERSION);
144 e = (char *)ext_acl + sizeof(reiserfs_acl_header);
bd4c625c
LT
145 for (n = 0; n < acl->a_count; n++) {
146 reiserfs_acl_entry *entry = (reiserfs_acl_entry *) e;
147 entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
1da177e4 148 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
bd4c625c
LT
149 switch (acl->a_entries[n].e_tag) {
150 case ACL_USER:
151 case ACL_GROUP:
152 entry->e_id = cpu_to_le32(acl->a_entries[n].e_id);
153 e += sizeof(reiserfs_acl_entry);
154 break;
155
156 case ACL_USER_OBJ:
157 case ACL_GROUP_OBJ:
158 case ACL_MASK:
159 case ACL_OTHER:
160 e += sizeof(reiserfs_acl_entry_short);
161 break;
162
163 default:
164 goto fail;
1da177e4
LT
165 }
166 }
167 return (char *)ext_acl;
168
bd4c625c 169 fail:
1da177e4
LT
170 kfree(ext_acl);
171 return ERR_PTR(-EINVAL);
172}
173
174/*
175 * Inode operation get_posix_acl().
176 *
177 * inode->i_sem: down
178 * BKL held [before 2.5.x]
179 */
bd4c625c 180struct posix_acl *reiserfs_get_acl(struct inode *inode, int type)
1da177e4
LT
181{
182 char *name, *value;
183 struct posix_acl *acl, **p_acl;
184 size_t size;
185 int retval;
bd4c625c
LT
186 struct reiserfs_inode_info *reiserfs_i = REISERFS_I(inode);
187
188 switch (type) {
189 case ACL_TYPE_ACCESS:
190 name = POSIX_ACL_XATTR_ACCESS;
191 p_acl = &reiserfs_i->i_acl_access;
192 break;
193 case ACL_TYPE_DEFAULT:
194 name = POSIX_ACL_XATTR_DEFAULT;
195 p_acl = &reiserfs_i->i_acl_default;
196 break;
197 default:
198 return ERR_PTR(-EINVAL);
199 }
200
201 if (IS_ERR(*p_acl)) {
202 if (PTR_ERR(*p_acl) == -ENODATA)
203 return NULL;
204 } else if (*p_acl != NULL)
205 return posix_acl_dup(*p_acl);
206
207 size = reiserfs_xattr_get(inode, name, NULL, 0);
208 if ((int)size < 0) {
209 if (size == -ENODATA || size == -ENOSYS) {
210 *p_acl = ERR_PTR(-ENODATA);
211 return NULL;
212 }
213 return ERR_PTR(size);
214 }
1da177e4 215
bd4c625c
LT
216 value = kmalloc(size, GFP_NOFS);
217 if (!value)
218 return ERR_PTR(-ENOMEM);
1da177e4
LT
219
220 retval = reiserfs_xattr_get(inode, name, value, size);
221 if (retval == -ENODATA || retval == -ENOSYS) {
222 /* This shouldn't actually happen as it should have
223 been caught above.. but just in case */
224 acl = NULL;
bd4c625c
LT
225 *p_acl = ERR_PTR(-ENODATA);
226 } else if (retval < 0) {
1da177e4
LT
227 acl = ERR_PTR(retval);
228 } else {
229 acl = posix_acl_from_disk(value, retval);
bd4c625c
LT
230 *p_acl = posix_acl_dup(acl);
231 }
1da177e4
LT
232
233 kfree(value);
234 return acl;
235}
236
237/*
238 * Inode operation set_posix_acl().
239 *
240 * inode->i_sem: down
241 * BKL held [before 2.5.x]
242 */
243static int
244reiserfs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
245{
bd4c625c 246 char *name;
1da177e4
LT
247 void *value = NULL;
248 struct posix_acl **p_acl;
249 size_t size;
250 int error;
bd4c625c 251 struct reiserfs_inode_info *reiserfs_i = REISERFS_I(inode);
1da177e4
LT
252
253 if (S_ISLNK(inode->i_mode))
254 return -EOPNOTSUPP;
255
bd4c625c
LT
256 switch (type) {
257 case ACL_TYPE_ACCESS:
258 name = POSIX_ACL_XATTR_ACCESS;
259 p_acl = &reiserfs_i->i_acl_access;
260 if (acl) {
261 mode_t mode = inode->i_mode;
262 error = posix_acl_equiv_mode(acl, &mode);
263 if (error < 0)
264 return error;
265 else {
266 inode->i_mode = mode;
267 if (error == 0)
268 acl = NULL;
269 }
270 }
271 break;
272 case ACL_TYPE_DEFAULT:
273 name = POSIX_ACL_XATTR_DEFAULT;
274 p_acl = &reiserfs_i->i_acl_default;
275 if (!S_ISDIR(inode->i_mode))
276 return acl ? -EACCES : 0;
277 break;
278 default:
279 return -EINVAL;
280 }
281
282 if (acl) {
283 value = posix_acl_to_disk(acl, &size);
284 if (IS_ERR(value))
285 return (int)PTR_ERR(value);
286 error = reiserfs_xattr_set(inode, name, value, size, 0);
1da177e4 287 } else {
bd4c625c
LT
288 error = reiserfs_xattr_del(inode, name);
289 if (error == -ENODATA) {
290 /* This may seem odd here, but it means that the ACL was set
291 * with a value representable with mode bits. If there was
292 * an ACL before, reiserfs_xattr_del already dirtied the inode.
293 */
294 mark_inode_dirty(inode);
295 error = 0;
296 }
297 }
1da177e4 298
833d304b 299 kfree(value);
1da177e4 300
bd4c625c
LT
301 if (!error) {
302 /* Release the old one */
303 if (!IS_ERR(*p_acl) && *p_acl)
304 posix_acl_release(*p_acl);
1da177e4 305
bd4c625c
LT
306 if (acl == NULL)
307 *p_acl = ERR_PTR(-ENODATA);
308 else
309 *p_acl = posix_acl_dup(acl);
310 }
1da177e4
LT
311
312 return error;
313}
314
315/* dir->i_sem: down,
316 * inode is new and not released into the wild yet */
317int
bd4c625c
LT
318reiserfs_inherit_default_acl(struct inode *dir, struct dentry *dentry,
319 struct inode *inode)
1da177e4 320{
bd4c625c
LT
321 struct posix_acl *acl;
322 int err = 0;
323
324 /* ACLs only get applied to files and directories */
325 if (S_ISLNK(inode->i_mode))
326 return 0;
327
328 /* ACLs can only be used on "new" objects, so if it's an old object
329 * there is nothing to inherit from */
330 if (get_inode_sd_version(dir) == STAT_DATA_V1)
331 goto apply_umask;
332
333 /* Don't apply ACLs to objects in the .reiserfs_priv tree.. This
334 * would be useless since permissions are ignored, and a pain because
335 * it introduces locking cycles */
336 if (is_reiserfs_priv_object(dir)) {
337 reiserfs_mark_inode_private(inode);
338 goto apply_umask;
339 }
340
341 acl = reiserfs_get_acl(dir, ACL_TYPE_DEFAULT);
342 if (IS_ERR(acl)) {
343 if (PTR_ERR(acl) == -ENODATA)
344 goto apply_umask;
345 return PTR_ERR(acl);
346 }
347
348 if (acl) {
349 struct posix_acl *acl_copy;
350 mode_t mode = inode->i_mode;
351 int need_acl;
352
353 /* Copy the default ACL to the default ACL of a new directory */
354 if (S_ISDIR(inode->i_mode)) {
355 err = reiserfs_set_acl(inode, ACL_TYPE_DEFAULT, acl);
356 if (err)
357 goto cleanup;
358 }
359
360 /* Now we reconcile the new ACL and the mode,
361 potentially modifying both */
362 acl_copy = posix_acl_clone(acl, GFP_NOFS);
363 if (!acl_copy) {
364 err = -ENOMEM;
365 goto cleanup;
366 }
367
368 need_acl = posix_acl_create_masq(acl_copy, &mode);
369 if (need_acl >= 0) {
370 if (mode != inode->i_mode) {
371 inode->i_mode = mode;
372 }
373
374 /* If we need an ACL.. */
375 if (need_acl > 0) {
376 err =
377 reiserfs_set_acl(inode, ACL_TYPE_ACCESS,
378 acl_copy);
379 if (err)
380 goto cleanup_copy;
381 }
382 }
383 cleanup_copy:
384 posix_acl_release(acl_copy);
385 cleanup:
386 posix_acl_release(acl);
387 } else {
388 apply_umask:
389 /* no ACL, apply umask */
390 inode->i_mode &= ~current->fs->umask;
391 }
392
393 return err;
1da177e4
LT
394}
395
396/* Looks up and caches the result of the default ACL.
397 * We do this so that we don't need to carry the xattr_sem into
398 * reiserfs_new_inode if we don't need to */
bd4c625c 399int reiserfs_cache_default_acl(struct inode *inode)
1da177e4 400{
bd4c625c
LT
401 int ret = 0;
402 if (reiserfs_posixacl(inode->i_sb) && !is_reiserfs_priv_object(inode)) {
403 struct posix_acl *acl;
404 reiserfs_read_lock_xattr_i(inode);
405 reiserfs_read_lock_xattrs(inode->i_sb);
406 acl = reiserfs_get_acl(inode, ACL_TYPE_DEFAULT);
407 reiserfs_read_unlock_xattrs(inode->i_sb);
408 reiserfs_read_unlock_xattr_i(inode);
409 ret = acl ? 1 : 0;
410 posix_acl_release(acl);
411 }
412
413 return ret;
1da177e4
LT
414}
415
bd4c625c 416int reiserfs_acl_chmod(struct inode *inode)
1da177e4 417{
bd4c625c
LT
418 struct posix_acl *acl, *clone;
419 int error;
1da177e4 420
bd4c625c
LT
421 if (S_ISLNK(inode->i_mode))
422 return -EOPNOTSUPP;
1da177e4 423
bd4c625c
LT
424 if (get_inode_sd_version(inode) == STAT_DATA_V1 ||
425 !reiserfs_posixacl(inode->i_sb)) {
426 return 0;
1da177e4
LT
427 }
428
bd4c625c
LT
429 reiserfs_read_lock_xattrs(inode->i_sb);
430 acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
431 reiserfs_read_unlock_xattrs(inode->i_sb);
432 if (!acl)
433 return 0;
434 if (IS_ERR(acl))
435 return PTR_ERR(acl);
436 clone = posix_acl_clone(acl, GFP_NOFS);
437 posix_acl_release(acl);
438 if (!clone)
439 return -ENOMEM;
440 error = posix_acl_chmod_masq(clone, inode->i_mode);
441 if (!error) {
442 int lock = !has_xattr_dir(inode);
443 reiserfs_write_lock_xattr_i(inode);
444 if (lock)
445 reiserfs_write_lock_xattrs(inode->i_sb);
446 else
447 reiserfs_read_lock_xattrs(inode->i_sb);
448 error = reiserfs_set_acl(inode, ACL_TYPE_ACCESS, clone);
449 if (lock)
450 reiserfs_write_unlock_xattrs(inode->i_sb);
451 else
452 reiserfs_read_unlock_xattrs(inode->i_sb);
453 reiserfs_write_unlock_xattr_i(inode);
454 }
455 posix_acl_release(clone);
456 return error;
1da177e4
LT
457}
458
459static int
460posix_acl_access_get(struct inode *inode, const char *name,
bd4c625c 461 void *buffer, size_t size)
1da177e4 462{
bd4c625c 463 if (strlen(name) != sizeof(POSIX_ACL_XATTR_ACCESS) - 1)
1da177e4
LT
464 return -EINVAL;
465 return xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size);
466}
467
468static int
469posix_acl_access_set(struct inode *inode, const char *name,
bd4c625c 470 const void *value, size_t size, int flags)
1da177e4 471{
bd4c625c 472 if (strlen(name) != sizeof(POSIX_ACL_XATTR_ACCESS) - 1)
1da177e4
LT
473 return -EINVAL;
474 return xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
475}
476
bd4c625c 477static int posix_acl_access_del(struct inode *inode, const char *name)
1da177e4 478{
bd4c625c
LT
479 struct reiserfs_inode_info *reiserfs_i = REISERFS_I(inode);
480 struct posix_acl **acl = &reiserfs_i->i_acl_access;
481 if (strlen(name) != sizeof(POSIX_ACL_XATTR_ACCESS) - 1)
482 return -EINVAL;
483 if (!IS_ERR(*acl) && *acl) {
484 posix_acl_release(*acl);
485 *acl = ERR_PTR(-ENODATA);
486 }
487
488 return 0;
1da177e4
LT
489}
490
491static int
bd4c625c
LT
492posix_acl_access_list(struct inode *inode, const char *name, int namelen,
493 char *out)
1da177e4 494{
bd4c625c
LT
495 int len = namelen;
496 if (!reiserfs_posixacl(inode->i_sb))
497 return 0;
498 if (out)
499 memcpy(out, name, len);
1da177e4 500
bd4c625c 501 return len;
1da177e4
LT
502}
503
504struct reiserfs_xattr_handler posix_acl_access_handler = {
9a59f452 505 .prefix = POSIX_ACL_XATTR_ACCESS,
1da177e4
LT
506 .get = posix_acl_access_get,
507 .set = posix_acl_access_set,
508 .del = posix_acl_access_del,
509 .list = posix_acl_access_list,
510};
511
512static int
bd4c625c
LT
513posix_acl_default_get(struct inode *inode, const char *name,
514 void *buffer, size_t size)
1da177e4 515{
bd4c625c 516 if (strlen(name) != sizeof(POSIX_ACL_XATTR_DEFAULT) - 1)
1da177e4
LT
517 return -EINVAL;
518 return xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size);
519}
520
521static int
522posix_acl_default_set(struct inode *inode, const char *name,
bd4c625c 523 const void *value, size_t size, int flags)
1da177e4 524{
bd4c625c 525 if (strlen(name) != sizeof(POSIX_ACL_XATTR_DEFAULT) - 1)
1da177e4
LT
526 return -EINVAL;
527 return xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
528}
529
bd4c625c 530static int posix_acl_default_del(struct inode *inode, const char *name)
1da177e4 531{
bd4c625c
LT
532 struct reiserfs_inode_info *reiserfs_i = REISERFS_I(inode);
533 struct posix_acl **acl = &reiserfs_i->i_acl_default;
534 if (strlen(name) != sizeof(POSIX_ACL_XATTR_DEFAULT) - 1)
535 return -EINVAL;
536 if (!IS_ERR(*acl) && *acl) {
537 posix_acl_release(*acl);
538 *acl = ERR_PTR(-ENODATA);
539 }
540
541 return 0;
1da177e4
LT
542}
543
544static int
bd4c625c
LT
545posix_acl_default_list(struct inode *inode, const char *name, int namelen,
546 char *out)
1da177e4 547{
bd4c625c
LT
548 int len = namelen;
549 if (!reiserfs_posixacl(inode->i_sb))
550 return 0;
551 if (out)
552 memcpy(out, name, len);
1da177e4 553
bd4c625c 554 return len;
1da177e4
LT
555}
556
557struct reiserfs_xattr_handler posix_acl_default_handler = {
9a59f452 558 .prefix = POSIX_ACL_XATTR_DEFAULT,
1da177e4
LT
559 .get = posix_acl_default_get,
560 .set = posix_acl_default_set,
561 .del = posix_acl_default_del,
562 .list = posix_acl_default_list,
563};