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