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mm-only debug patch...
[mmotm.git] / fs / reiserfs / xattr_acl.c
blob35d6e672a2796f7aaed49b31f96621c25593c51b
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 /*
192 * Inode operation get_posix_acl().
193 *
194 * inode->i_mutex: down
195 * BKL held [before 2.5.x]
196 */
197 struct posix_acl *reiserfs_get_acl(struct inode *inode, int type)
198 {
199 char *name, *value;
200 struct posix_acl *acl;
201 int size;
202 int retval;
203
204 acl = get_cached_acl(inode, type);
205 if (acl != ACL_NOT_CACHED)
206 return acl;
207
208 switch (type) {
209 case ACL_TYPE_ACCESS:
210 name = POSIX_ACL_XATTR_ACCESS;
211 break;
212 case ACL_TYPE_DEFAULT:
213 name = POSIX_ACL_XATTR_DEFAULT;
214 break;
215 default:
216 BUG();
217 }
218
219 size = reiserfs_xattr_get(inode, name, NULL, 0);
220 if (size < 0) {
221 if (size == -ENODATA || size == -ENOSYS) {
222 set_cached_acl(inode, type, NULL);
223 return NULL;
224 }
225 return ERR_PTR(size);
226 }
227
228 value = kmalloc(size, GFP_NOFS);
229 if (!value)
230 return ERR_PTR(-ENOMEM);
231
232 retval = reiserfs_xattr_get(inode, name, value, size);
233 if (retval == -ENODATA || retval == -ENOSYS) {
234 /* This shouldn't actually happen as it should have
235 been caught above.. but just in case */
236 acl = NULL;
237 } else if (retval < 0) {
238 acl = ERR_PTR(retval);
239 } else {
240 acl = posix_acl_from_disk(value, retval);
241 }
242 if (!IS_ERR(acl))
243 set_cached_acl(inode, type, acl);
244
245 kfree(value);
246 return acl;
247 }
248
249 /*
250 * Inode operation set_posix_acl().
251 *
252 * inode->i_mutex: down
253 * BKL held [before 2.5.x]
254 */
255 static int
256 reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode,
257 int type, struct posix_acl *acl)
258 {
259 char *name;
260 void *value = NULL;
261 size_t size = 0;
262 int error;
263
264 if (S_ISLNK(inode->i_mode))
265 return -EOPNOTSUPP;
266
267 switch (type) {
268 case ACL_TYPE_ACCESS:
269 name = POSIX_ACL_XATTR_ACCESS;
270 if (acl) {
271 mode_t mode = inode->i_mode;
272 error = posix_acl_equiv_mode(acl, &mode);
273 if (error < 0)
274 return error;
275 else {
276 inode->i_mode = mode;
277 if (error == 0)
278 acl = NULL;
279 }
280 }
281 break;
282 case ACL_TYPE_DEFAULT:
283 name = POSIX_ACL_XATTR_DEFAULT;
284 if (!S_ISDIR(inode->i_mode))
285 return acl ? -EACCES : 0;
286 break;
287 default:
288 return -EINVAL;
289 }
290
291 if (acl) {
292 value = posix_acl_to_disk(acl, &size);
293 if (IS_ERR(value))
294 return (int)PTR_ERR(value);
295 }
296
297 error = reiserfs_xattr_set_handle(th, inode, name, value, size, 0);
298
299 /*
300 * Ensure that the inode gets dirtied if we're only using
301 * the mode bits and an old ACL didn't exist. We don't need
302 * to check if the inode is hashed here since we won't get
303 * called by reiserfs_inherit_default_acl().
304 */
305 if (error == -ENODATA) {
306 error = 0;
307 if (type == ACL_TYPE_ACCESS) {
308 inode->i_ctime = CURRENT_TIME_SEC;
309 mark_inode_dirty(inode);
310 }
311 }
312
313 kfree(value);
314
315 if (!error)
316 set_cached_acl(inode, type, acl);
317
318 return error;
319 }
320
321 /* dir->i_mutex: locked,
322 * inode is new and not released into the wild yet */
323 int
324 reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th,
325 struct inode *dir, struct dentry *dentry,
326 struct inode *inode)
327 {
328 struct posix_acl *acl;
329 int err = 0;
330
331 /* ACLs only get applied to files and directories */
332 if (S_ISLNK(inode->i_mode))
333 return 0;
334
335 /* ACLs can only be used on "new" objects, so if it's an old object
336 * there is nothing to inherit from */
337 if (get_inode_sd_version(dir) == STAT_DATA_V1)
338 goto apply_umask;
339
340 /* Don't apply ACLs to objects in the .reiserfs_priv tree.. This
341 * would be useless since permissions are ignored, and a pain because
342 * it introduces locking cycles */
343 if (IS_PRIVATE(dir)) {
344 inode->i_flags |= S_PRIVATE;
345 goto apply_umask;
346 }
347
348 acl = reiserfs_get_acl(dir, ACL_TYPE_DEFAULT);
349 if (IS_ERR(acl))
350 return PTR_ERR(acl);
351
352 if (acl) {
353 struct posix_acl *acl_copy;
354 mode_t mode = inode->i_mode;
355 int need_acl;
356
357 /* Copy the default ACL to the default ACL of a new directory */
358 if (S_ISDIR(inode->i_mode)) {
359 err = reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT,
360 acl);
361 if (err)
362 goto cleanup;
363 }
364
365 /* Now we reconcile the new ACL and the mode,
366 potentially modifying both */
367 acl_copy = posix_acl_clone(acl, GFP_NOFS);
368 if (!acl_copy) {
369 err = -ENOMEM;
370 goto cleanup;
371 }
372
373 need_acl = posix_acl_create_masq(acl_copy, &mode);
374 if (need_acl >= 0) {
375 if (mode != inode->i_mode) {
376 inode->i_mode = mode;
377 }
378
379 /* If we need an ACL.. */
380 if (need_acl > 0) {
381 err = reiserfs_set_acl(th, inode,
382 ACL_TYPE_ACCESS,
383 acl_copy);
384 if (err)
385 goto cleanup_copy;
386 }
387 }
388 cleanup_copy:
389 posix_acl_release(acl_copy);
390 cleanup:
391 posix_acl_release(acl);
392 } else {
393 apply_umask:
394 /* no ACL, apply umask */
395 inode->i_mode &= ~current_umask();
396 }
397
398 return err;
399 }
400
401 /* This is used to cache the default acl before a new object is created.
402 * The biggest reason for this is to get an idea of how many blocks will
403 * actually be required for the create operation if we must inherit an ACL.
404 * An ACL write can add up to 3 object creations and an additional file write
405 * so we'd prefer not to reserve that many blocks in the journal if we can.
406 * It also has the advantage of not loading the ACL with a transaction open,
407 * this may seem silly, but if the owner of the directory is doing the
408 * creation, the ACL may not be loaded since the permissions wouldn't require
409 * it.
410 * We return the number of blocks required for the transaction.
411 */
412 int reiserfs_cache_default_acl(struct inode *inode)
413 {
414 struct posix_acl *acl;
415 int nblocks = 0;
416
417 if (IS_PRIVATE(inode))
418 return 0;
419
420 acl = reiserfs_get_acl(inode, ACL_TYPE_DEFAULT);
421
422 if (acl && !IS_ERR(acl)) {
423 int size = reiserfs_acl_size(acl->a_count);
424
425 /* Other xattrs can be created during inode creation. We don't
426 * want to claim too many blocks, so we check to see if we
427 * we need to create the tree to the xattrs, and then we
428 * just want two files. */
429 nblocks = reiserfs_xattr_jcreate_nblocks(inode);
430 nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb);
431
432 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
433
434 /* We need to account for writes + bitmaps for two files */
435 nblocks += reiserfs_xattr_nblocks(inode, size) * 4;
436 posix_acl_release(acl);
437 }
438
439 return nblocks;
440 }
441
442 int reiserfs_acl_chmod(struct inode *inode)
443 {
444 struct posix_acl *acl, *clone;
445 int error;
446
447 if (S_ISLNK(inode->i_mode))
448 return -EOPNOTSUPP;
449
450 if (get_inode_sd_version(inode) == STAT_DATA_V1 ||
451 !reiserfs_posixacl(inode->i_sb)) {
452 return 0;
453 }
454
455 acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
456 if (!acl)
457 return 0;
458 if (IS_ERR(acl))
459 return PTR_ERR(acl);
460 clone = posix_acl_clone(acl, GFP_NOFS);
461 posix_acl_release(acl);
462 if (!clone)
463 return -ENOMEM;
464 error = posix_acl_chmod_masq(clone, inode->i_mode);
465 if (!error) {
466 struct reiserfs_transaction_handle th;
467 size_t size = reiserfs_xattr_nblocks(inode,
468 reiserfs_acl_size(clone->a_count));
469 reiserfs_write_lock(inode->i_sb);
470 error = journal_begin(&th, inode->i_sb, size * 2);
471 if (!error) {
472 int error2;
473 error = reiserfs_set_acl(&th, inode, ACL_TYPE_ACCESS,
474 clone);
475 error2 = journal_end(&th, inode->i_sb, size * 2);
476 if (error2)
477 error = error2;
478 }
479 reiserfs_write_unlock(inode->i_sb);
480 }
481 posix_acl_release(clone);
482 return error;
483 }
484
485 static int
486 posix_acl_access_get(struct inode *inode, const char *name,
487 void *buffer, size_t size)
488 {
489 if (strlen(name) != sizeof(POSIX_ACL_XATTR_ACCESS) - 1)
490 return -EINVAL;
491 return xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size);
492 }
493
494 static int
495 posix_acl_access_set(struct inode *inode, const char *name,
496 const void *value, size_t size, int flags)
497 {
498 if (strlen(name) != sizeof(POSIX_ACL_XATTR_ACCESS) - 1)
499 return -EINVAL;
500 return xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
501 }
502
503 static size_t posix_acl_access_list(struct inode *inode, char *list,
504 size_t list_size, const char *name,
505 size_t name_len)
506 {
507 const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
508 if (!reiserfs_posixacl(inode->i_sb))
509 return 0;
510 if (list && size <= list_size)
511 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
512 return size;
513 }
514
515 struct xattr_handler reiserfs_posix_acl_access_handler = {
516 .prefix = POSIX_ACL_XATTR_ACCESS,
517 .get = posix_acl_access_get,
518 .set = posix_acl_access_set,
519 .list = posix_acl_access_list,
520 };
521
522 static int
523 posix_acl_default_get(struct inode *inode, const char *name,
524 void *buffer, size_t size)
525 {
526 if (strlen(name) != sizeof(POSIX_ACL_XATTR_DEFAULT) - 1)
527 return -EINVAL;
528 return xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size);
529 }
530
531 static int
532 posix_acl_default_set(struct inode *inode, const char *name,
533 const void *value, size_t size, int flags)
534 {
535 if (strlen(name) != sizeof(POSIX_ACL_XATTR_DEFAULT) - 1)
536 return -EINVAL;
537 return xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
538 }
539
540 static size_t posix_acl_default_list(struct inode *inode, char *list,
541 size_t list_size, const char *name,
542 size_t name_len)
543 {
544 const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
545 if (!reiserfs_posixacl(inode->i_sb))
546 return 0;
547 if (list && size <= list_size)
548 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
549 return size;
550 }
551
552 struct xattr_handler reiserfs_posix_acl_default_handler = {
553 .prefix = POSIX_ACL_XATTR_DEFAULT,
554 .get = posix_acl_default_get,
555 .set = posix_acl_default_set,
556 .list = posix_acl_default_list,
557 };
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