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New helper - current_umask()
[deliverable/linux.git] / fs / reiserfs / xattr_acl.c
1 #include <linux/capability.h>
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>
8 #include <linux/posix_acl_xattr.h>
9 #include <linux/reiserfs_xattr.h>
10 #include <linux/reiserfs_acl.h>
11 #include <asm/uaccess.h>
12
13 static int reiserfs_set_acl(struct reiserfs_transaction_handle *th,
14 struct inode *inode, int type,
15 struct posix_acl *acl);
16
17 static int
18 xattr_set_acl(struct inode *inode, int type, const void *value, size_t size)
19 {
20 struct posix_acl *acl;
21 int error, error2;
22 struct reiserfs_transaction_handle th;
23 size_t jcreate_blocks;
24 if (!reiserfs_posixacl(inode->i_sb))
25 return -EOPNOTSUPP;
26 if (!is_owner_or_cap(inode))
27 return -EPERM;
28
29 if (value) {
30 acl = posix_acl_from_xattr(value, size);
31 if (IS_ERR(acl)) {
32 return PTR_ERR(acl);
33 } else if (acl) {
34 error = posix_acl_valid(acl);
35 if (error)
36 goto release_and_out;
37 }
38 } else
39 acl = NULL;
40
41 /* Pessimism: We can't assume that anything from the xattr root up
42 * has been created. */
43
44 jcreate_blocks = reiserfs_xattr_jcreate_nblocks(inode) +
45 reiserfs_xattr_nblocks(inode, size) * 2;
46
47 reiserfs_write_lock(inode->i_sb);
48 error = journal_begin(&th, inode->i_sb, jcreate_blocks);
49 if (error == 0) {
50 error = reiserfs_set_acl(&th, inode, type, acl);
51 error2 = journal_end(&th, inode->i_sb, jcreate_blocks);
52 if (error2)
53 error = error2;
54 }
55 reiserfs_write_unlock(inode->i_sb);
56
57 release_and_out:
58 posix_acl_release(acl);
59 return error;
60 }
61
62 static int
63 xattr_get_acl(struct inode *inode, int type, void *buffer, size_t size)
64 {
65 struct posix_acl *acl;
66 int error;
67
68 if (!reiserfs_posixacl(inode->i_sb))
69 return -EOPNOTSUPP;
70
71 acl = reiserfs_get_acl(inode, type);
72 if (IS_ERR(acl))
73 return PTR_ERR(acl);
74 if (acl == NULL)
75 return -ENODATA;
76 error = posix_acl_to_xattr(acl, buffer, size);
77 posix_acl_release(acl);
78
79 return error;
80 }
81
82 /*
83 * Convert from filesystem to in-memory representation.
84 */
85 static struct posix_acl *posix_acl_from_disk(const void *value, size_t size)
86 {
87 const char *end = (char *)value + size;
88 int n, count;
89 struct posix_acl *acl;
90
91 if (!value)
92 return NULL;
93 if (size < sizeof(reiserfs_acl_header))
94 return ERR_PTR(-EINVAL);
95 if (((reiserfs_acl_header *) value)->a_version !=
96 cpu_to_le32(REISERFS_ACL_VERSION))
97 return ERR_PTR(-EINVAL);
98 value = (char *)value + sizeof(reiserfs_acl_header);
99 count = reiserfs_acl_count(size);
100 if (count < 0)
101 return ERR_PTR(-EINVAL);
102 if (count == 0)
103 return NULL;
104 acl = posix_acl_alloc(count, GFP_NOFS);
105 if (!acl)
106 return ERR_PTR(-ENOMEM);
107 for (n = 0; n < count; n++) {
108 reiserfs_acl_entry *entry = (reiserfs_acl_entry *) value;
109 if ((char *)value + sizeof(reiserfs_acl_entry_short) > end)
110 goto fail;
111 acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
112 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
113 switch (acl->a_entries[n].e_tag) {
114 case ACL_USER_OBJ:
115 case ACL_GROUP_OBJ:
116 case ACL_MASK:
117 case ACL_OTHER:
118 value = (char *)value +
119 sizeof(reiserfs_acl_entry_short);
120 acl->a_entries[n].e_id = ACL_UNDEFINED_ID;
121 break;
122
123 case ACL_USER:
124 case ACL_GROUP:
125 value = (char *)value + sizeof(reiserfs_acl_entry);
126 if ((char *)value > end)
127 goto fail;
128 acl->a_entries[n].e_id = le32_to_cpu(entry->e_id);
129 break;
130
131 default:
132 goto fail;
133 }
134 }
135 if (value != end)
136 goto fail;
137 return acl;
138
139 fail:
140 posix_acl_release(acl);
141 return ERR_PTR(-EINVAL);
142 }
143
144 /*
145 * Convert from in-memory to filesystem representation.
146 */
147 static void *posix_acl_to_disk(const struct posix_acl *acl, size_t * size)
148 {
149 reiserfs_acl_header *ext_acl;
150 char *e;
151 int n;
152
153 *size = reiserfs_acl_size(acl->a_count);
154 ext_acl = kmalloc(sizeof(reiserfs_acl_header) +
155 acl->a_count *
156 sizeof(reiserfs_acl_entry),
157 GFP_NOFS);
158 if (!ext_acl)
159 return ERR_PTR(-ENOMEM);
160 ext_acl->a_version = cpu_to_le32(REISERFS_ACL_VERSION);
161 e = (char *)ext_acl + sizeof(reiserfs_acl_header);
162 for (n = 0; n < acl->a_count; n++) {
163 reiserfs_acl_entry *entry = (reiserfs_acl_entry *) e;
164 entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
165 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
166 switch (acl->a_entries[n].e_tag) {
167 case ACL_USER:
168 case ACL_GROUP:
169 entry->e_id = cpu_to_le32(acl->a_entries[n].e_id);
170 e += sizeof(reiserfs_acl_entry);
171 break;
172
173 case ACL_USER_OBJ:
174 case ACL_GROUP_OBJ:
175 case ACL_MASK:
176 case ACL_OTHER:
177 e += sizeof(reiserfs_acl_entry_short);
178 break;
179
180 default:
181 goto fail;
182 }
183 }
184 return (char *)ext_acl;
185
186 fail:
187 kfree(ext_acl);
188 return ERR_PTR(-EINVAL);
189 }
190
191 static inline void iset_acl(struct inode *inode, struct posix_acl **i_acl,
192 struct posix_acl *acl)
193 {
194 spin_lock(&inode->i_lock);
195 if (*i_acl != ERR_PTR(-ENODATA))
196 posix_acl_release(*i_acl);
197 *i_acl = posix_acl_dup(acl);
198 spin_unlock(&inode->i_lock);
199 }
200
201 static inline struct posix_acl *iget_acl(struct inode *inode,
202 struct posix_acl **i_acl)
203 {
204 struct posix_acl *acl = ERR_PTR(-ENODATA);
205
206 spin_lock(&inode->i_lock);
207 if (*i_acl != ERR_PTR(-ENODATA))
208 acl = posix_acl_dup(*i_acl);
209 spin_unlock(&inode->i_lock);
210
211 return acl;
212 }
213
214 /*
215 * Inode operation get_posix_acl().
216 *
217 * inode->i_mutex: down
218 * BKL held [before 2.5.x]
219 */
220 struct posix_acl *reiserfs_get_acl(struct inode *inode, int type)
221 {
222 char *name, *value;
223 struct posix_acl *acl, **p_acl;
224 int size;
225 int retval;
226 struct reiserfs_inode_info *reiserfs_i = REISERFS_I(inode);
227
228 switch (type) {
229 case ACL_TYPE_ACCESS:
230 name = POSIX_ACL_XATTR_ACCESS;
231 p_acl = &reiserfs_i->i_acl_access;
232 break;
233 case ACL_TYPE_DEFAULT:
234 name = POSIX_ACL_XATTR_DEFAULT;
235 p_acl = &reiserfs_i->i_acl_default;
236 break;
237 default:
238 return ERR_PTR(-EINVAL);
239 }
240
241 acl = iget_acl(inode, p_acl);
242 if (acl && !IS_ERR(acl))
243 return acl;
244 else if (PTR_ERR(acl) == -ENODATA)
245 return NULL;
246
247 size = reiserfs_xattr_get(inode, name, NULL, 0);
248 if (size < 0) {
249 if (size == -ENODATA || size == -ENOSYS) {
250 *p_acl = ERR_PTR(-ENODATA);
251 return NULL;
252 }
253 return ERR_PTR(size);
254 }
255
256 value = kmalloc(size, GFP_NOFS);
257 if (!value)
258 return ERR_PTR(-ENOMEM);
259
260 retval = reiserfs_xattr_get(inode, name, value, size);
261 if (retval == -ENODATA || retval == -ENOSYS) {
262 /* This shouldn't actually happen as it should have
263 been caught above.. but just in case */
264 acl = NULL;
265 *p_acl = ERR_PTR(-ENODATA);
266 } else if (retval < 0) {
267 acl = ERR_PTR(retval);
268 } else {
269 acl = posix_acl_from_disk(value, retval);
270 if (!IS_ERR(acl))
271 iset_acl(inode, p_acl, acl);
272 }
273
274 kfree(value);
275 return acl;
276 }
277
278 /*
279 * Inode operation set_posix_acl().
280 *
281 * inode->i_mutex: down
282 * BKL held [before 2.5.x]
283 */
284 static int
285 reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode,
286 int type, struct posix_acl *acl)
287 {
288 char *name;
289 void *value = NULL;
290 struct posix_acl **p_acl;
291 size_t size = 0;
292 int error;
293 struct reiserfs_inode_info *reiserfs_i = REISERFS_I(inode);
294
295 if (S_ISLNK(inode->i_mode))
296 return -EOPNOTSUPP;
297
298 switch (type) {
299 case ACL_TYPE_ACCESS:
300 name = POSIX_ACL_XATTR_ACCESS;
301 p_acl = &reiserfs_i->i_acl_access;
302 if (acl) {
303 mode_t mode = inode->i_mode;
304 error = posix_acl_equiv_mode(acl, &mode);
305 if (error < 0)
306 return error;
307 else {
308 inode->i_mode = mode;
309 if (error == 0)
310 acl = NULL;
311 }
312 }
313 break;
314 case ACL_TYPE_DEFAULT:
315 name = POSIX_ACL_XATTR_DEFAULT;
316 p_acl = &reiserfs_i->i_acl_default;
317 if (!S_ISDIR(inode->i_mode))
318 return acl ? -EACCES : 0;
319 break;
320 default:
321 return -EINVAL;
322 }
323
324 if (acl) {
325 value = posix_acl_to_disk(acl, &size);
326 if (IS_ERR(value))
327 return (int)PTR_ERR(value);
328 }
329
330 error = reiserfs_xattr_set_handle(th, inode, name, value, size, 0);
331
332 /*
333 * Ensure that the inode gets dirtied if we're only using
334 * the mode bits and an old ACL didn't exist. We don't need
335 * to check if the inode is hashed here since we won't get
336 * called by reiserfs_inherit_default_acl().
337 */
338 if (error == -ENODATA) {
339 error = 0;
340 if (type == ACL_TYPE_ACCESS) {
341 inode->i_ctime = CURRENT_TIME_SEC;
342 mark_inode_dirty(inode);
343 }
344 }
345
346 kfree(value);
347
348 if (!error)
349 iset_acl(inode, p_acl, acl);
350
351 return error;
352 }
353
354 /* dir->i_mutex: locked,
355 * inode is new and not released into the wild yet */
356 int
357 reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th,
358 struct inode *dir, struct dentry *dentry,
359 struct inode *inode)
360 {
361 struct posix_acl *acl;
362 int err = 0;
363
364 /* ACLs only get applied to files and directories */
365 if (S_ISLNK(inode->i_mode))
366 return 0;
367
368 /* ACLs can only be used on "new" objects, so if it's an old object
369 * there is nothing to inherit from */
370 if (get_inode_sd_version(dir) == STAT_DATA_V1)
371 goto apply_umask;
372
373 /* Don't apply ACLs to objects in the .reiserfs_priv tree.. This
374 * would be useless since permissions are ignored, and a pain because
375 * it introduces locking cycles */
376 if (IS_PRIVATE(dir)) {
377 inode->i_flags |= S_PRIVATE;
378 goto apply_umask;
379 }
380
381 acl = reiserfs_get_acl(dir, ACL_TYPE_DEFAULT);
382 if (IS_ERR(acl)) {
383 if (PTR_ERR(acl) == -ENODATA)
384 goto apply_umask;
385 return PTR_ERR(acl);
386 }
387
388 if (acl) {
389 struct posix_acl *acl_copy;
390 mode_t mode = inode->i_mode;
391 int need_acl;
392
393 /* Copy the default ACL to the default ACL of a new directory */
394 if (S_ISDIR(inode->i_mode)) {
395 err = reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT,
396 acl);
397 if (err)
398 goto cleanup;
399 }
400
401 /* Now we reconcile the new ACL and the mode,
402 potentially modifying both */
403 acl_copy = posix_acl_clone(acl, GFP_NOFS);
404 if (!acl_copy) {
405 err = -ENOMEM;
406 goto cleanup;
407 }
408
409 need_acl = posix_acl_create_masq(acl_copy, &mode);
410 if (need_acl >= 0) {
411 if (mode != inode->i_mode) {
412 inode->i_mode = mode;
413 }
414
415 /* If we need an ACL.. */
416 if (need_acl > 0) {
417 err = reiserfs_set_acl(th, inode,
418 ACL_TYPE_ACCESS,
419 acl_copy);
420 if (err)
421 goto cleanup_copy;
422 }
423 }
424 cleanup_copy:
425 posix_acl_release(acl_copy);
426 cleanup:
427 posix_acl_release(acl);
428 } else {
429 apply_umask:
430 /* no ACL, apply umask */
431 inode->i_mode &= ~current_umask();
432 }
433
434 return err;
435 }
436
437 /* This is used to cache the default acl before a new object is created.
438 * The biggest reason for this is to get an idea of how many blocks will
439 * actually be required for the create operation if we must inherit an ACL.
440 * An ACL write can add up to 3 object creations and an additional file write
441 * so we'd prefer not to reserve that many blocks in the journal if we can.
442 * It also has the advantage of not loading the ACL with a transaction open,
443 * this may seem silly, but if the owner of the directory is doing the
444 * creation, the ACL may not be loaded since the permissions wouldn't require
445 * it.
446 * We return the number of blocks required for the transaction.
447 */
448 int reiserfs_cache_default_acl(struct inode *inode)
449 {
450 struct posix_acl *acl;
451 int nblocks = 0;
452
453 if (IS_PRIVATE(inode))
454 return 0;
455
456 acl = reiserfs_get_acl(inode, ACL_TYPE_DEFAULT);
457
458 if (acl && !IS_ERR(acl)) {
459 int size = reiserfs_acl_size(acl->a_count);
460
461 /* Other xattrs can be created during inode creation. We don't
462 * want to claim too many blocks, so we check to see if we
463 * we need to create the tree to the xattrs, and then we
464 * just want two files. */
465 nblocks = reiserfs_xattr_jcreate_nblocks(inode);
466 nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb);
467
468 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
469
470 /* We need to account for writes + bitmaps for two files */
471 nblocks += reiserfs_xattr_nblocks(inode, size) * 4;
472 posix_acl_release(acl);
473 }
474
475 return nblocks;
476 }
477
478 int reiserfs_acl_chmod(struct inode *inode)
479 {
480 struct posix_acl *acl, *clone;
481 int error;
482
483 if (S_ISLNK(inode->i_mode))
484 return -EOPNOTSUPP;
485
486 if (get_inode_sd_version(inode) == STAT_DATA_V1 ||
487 !reiserfs_posixacl(inode->i_sb)) {
488 return 0;
489 }
490
491 acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
492 if (!acl)
493 return 0;
494 if (IS_ERR(acl))
495 return PTR_ERR(acl);
496 clone = posix_acl_clone(acl, GFP_NOFS);
497 posix_acl_release(acl);
498 if (!clone)
499 return -ENOMEM;
500 error = posix_acl_chmod_masq(clone, inode->i_mode);
501 if (!error) {
502 struct reiserfs_transaction_handle th;
503 size_t size = reiserfs_xattr_nblocks(inode,
504 reiserfs_acl_size(clone->a_count));
505 reiserfs_write_lock(inode->i_sb);
506 error = journal_begin(&th, inode->i_sb, size * 2);
507 if (!error) {
508 int error2;
509 error = reiserfs_set_acl(&th, inode, ACL_TYPE_ACCESS,
510 clone);
511 error2 = journal_end(&th, inode->i_sb, size * 2);
512 if (error2)
513 error = error2;
514 }
515 reiserfs_write_unlock(inode->i_sb);
516 }
517 posix_acl_release(clone);
518 return error;
519 }
520
521 static int
522 posix_acl_access_get(struct inode *inode, const char *name,
523 void *buffer, size_t size)
524 {
525 if (strlen(name) != sizeof(POSIX_ACL_XATTR_ACCESS) - 1)
526 return -EINVAL;
527 return xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size);
528 }
529
530 static int
531 posix_acl_access_set(struct inode *inode, const char *name,
532 const void *value, size_t size, int flags)
533 {
534 if (strlen(name) != sizeof(POSIX_ACL_XATTR_ACCESS) - 1)
535 return -EINVAL;
536 return xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
537 }
538
539 static size_t posix_acl_access_list(struct inode *inode, char *list,
540 size_t list_size, const char *name,
541 size_t name_len)
542 {
543 const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
544 if (!reiserfs_posixacl(inode->i_sb))
545 return 0;
546 if (list && size <= list_size)
547 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
548 return size;
549 }
550
551 struct xattr_handler reiserfs_posix_acl_access_handler = {
552 .prefix = POSIX_ACL_XATTR_ACCESS,
553 .get = posix_acl_access_get,
554 .set = posix_acl_access_set,
555 .list = posix_acl_access_list,
556 };
557
558 static int
559 posix_acl_default_get(struct inode *inode, const char *name,
560 void *buffer, size_t size)
561 {
562 if (strlen(name) != sizeof(POSIX_ACL_XATTR_DEFAULT) - 1)
563 return -EINVAL;
564 return xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size);
565 }
566
567 static int
568 posix_acl_default_set(struct inode *inode, const char *name,
569 const void *value, size_t size, int flags)
570 {
571 if (strlen(name) != sizeof(POSIX_ACL_XATTR_DEFAULT) - 1)
572 return -EINVAL;
573 return xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
574 }
575
576 static size_t posix_acl_default_list(struct inode *inode, char *list,
577 size_t list_size, const char *name,
578 size_t name_len)
579 {
580 const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
581 if (!reiserfs_posixacl(inode->i_sb))
582 return 0;
583 if (list && size <= list_size)
584 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
585 return size;
586 }
587
588 struct xattr_handler reiserfs_posix_acl_default_handler = {
589 .prefix = POSIX_ACL_XATTR_DEFAULT,
590 .get = posix_acl_default_get,
591 .set = posix_acl_default_set,
592 .list = posix_acl_default_list,
593 };
Linux kernel - Deliverables
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