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5103e947 JB |
1 | /* |
2 | * Copyright (C) 2007 Red Hat. All rights reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public | |
14 | * License along with this program; if not, write to the | |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
16 | * Boston, MA 021110-1307, USA. | |
17 | */ | |
18 | ||
19 | #include <linux/init.h> | |
20 | #include <linux/fs.h> | |
21 | #include <linux/slab.h> | |
22 | #include <linux/rwsem.h> | |
23 | #include <linux/xattr.h> | |
24 | #include "ctree.h" | |
25 | #include "btrfs_inode.h" | |
26 | #include "transaction.h" | |
27 | #include "xattr.h" | |
28 | #include "disk-io.h" | |
29 | ||
30 | static struct xattr_handler *btrfs_xattr_handler_map[] = { | |
31 | [BTRFS_XATTR_INDEX_USER] = &btrfs_xattr_user_handler, | |
32 | [BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS] = &btrfs_xattr_acl_access_handler, | |
33 | [BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &btrfs_xattr_acl_default_handler, | |
34 | [BTRFS_XATTR_INDEX_TRUSTED] = &btrfs_xattr_trusted_handler, | |
35 | [BTRFS_XATTR_INDEX_SECURITY] = &btrfs_xattr_security_handler, | |
36 | [BTRFS_XATTR_INDEX_SYSTEM] = &btrfs_xattr_system_handler, | |
37 | }; | |
38 | ||
39 | struct xattr_handler *btrfs_xattr_handlers[] = { | |
40 | &btrfs_xattr_user_handler, | |
41 | &btrfs_xattr_acl_access_handler, | |
42 | &btrfs_xattr_acl_default_handler, | |
43 | &btrfs_xattr_trusted_handler, | |
44 | &btrfs_xattr_security_handler, | |
45 | &btrfs_xattr_system_handler, | |
46 | NULL, | |
47 | }; | |
48 | ||
49 | /* | |
50 | * @param name - the xattr name | |
51 | * @return - the xattr_handler for the xattr, NULL if its not found | |
52 | * | |
53 | * use this with listxattr where we don't already know the type of xattr we | |
54 | * have | |
55 | */ | |
56 | static struct xattr_handler *find_btrfs_xattr_handler(struct extent_buffer *l, | |
57 | unsigned long name_ptr, | |
58 | u16 name_len) | |
59 | { | |
60 | struct xattr_handler *handler = NULL; | |
61 | int i = 0; | |
62 | ||
63 | for (handler = btrfs_xattr_handlers[i]; handler != NULL; i++, | |
64 | handler = btrfs_xattr_handlers[i]) { | |
65 | u16 prefix_len = strlen(handler->prefix); | |
66 | ||
67 | if (name_len < prefix_len) | |
68 | continue; | |
69 | ||
70 | if (memcmp_extent_buffer(l, handler->prefix, name_ptr, | |
71 | prefix_len) == 0) | |
72 | break; | |
73 | } | |
74 | ||
75 | return handler; | |
76 | } | |
77 | ||
78 | /* | |
79 | * @param name_index - the index for the xattr handler | |
80 | * @return the xattr_handler if we found it, NULL otherwise | |
81 | * | |
82 | * use this if we know the type of the xattr already | |
83 | */ | |
84 | static struct xattr_handler *btrfs_xattr_handler(int name_index) | |
85 | { | |
86 | struct xattr_handler *handler = NULL; | |
87 | ||
88 | if (name_index >= 0 && | |
89 | name_index < ARRAY_SIZE(btrfs_xattr_handler_map)) | |
90 | handler = btrfs_xattr_handler_map[name_index]; | |
91 | ||
92 | return handler; | |
93 | } | |
94 | ||
95 | static inline char *get_name(const char *name, int name_index) | |
96 | { | |
97 | char *ret = NULL; | |
98 | struct xattr_handler *handler = btrfs_xattr_handler(name_index); | |
99 | int prefix_len; | |
100 | ||
101 | if (!handler) | |
102 | return ret; | |
103 | ||
104 | prefix_len = strlen(handler->prefix); | |
105 | ||
106 | ret = kmalloc(strlen(name) + prefix_len + 1, GFP_KERNEL); | |
107 | if (!ret) | |
108 | return ret; | |
109 | ||
110 | memcpy(ret, handler->prefix, prefix_len); | |
111 | memcpy(ret+prefix_len, name, strlen(name)); | |
112 | ret[prefix_len + strlen(name)] = '\0'; | |
113 | ||
114 | return ret; | |
115 | } | |
116 | ||
117 | size_t btrfs_xattr_generic_list(struct inode *inode, char *list, | |
118 | size_t list_size, const char *name, | |
119 | size_t name_len) | |
120 | { | |
121 | if (list && (name_len+1) <= list_size) { | |
122 | memcpy(list, name, name_len); | |
123 | list[name_len] = '\0'; | |
124 | } else | |
125 | return -ERANGE; | |
126 | ||
127 | return name_len+1; | |
128 | } | |
129 | ||
130 | ssize_t btrfs_xattr_get(struct inode *inode, int name_index, | |
131 | const char *attr_name, void *buffer, size_t size) | |
132 | { | |
133 | struct btrfs_dir_item *di; | |
134 | struct btrfs_root *root = BTRFS_I(inode)->root; | |
135 | struct btrfs_path *path; | |
136 | struct extent_buffer *leaf; | |
137 | struct xattr_handler *handler = btrfs_xattr_handler(name_index); | |
138 | int ret = 0; | |
139 | unsigned long data_ptr; | |
140 | char *name; | |
141 | ||
142 | if (!handler) | |
143 | return -EOPNOTSUPP; | |
144 | ||
145 | /* just in case... */ | |
146 | if (*attr_name == '\0') | |
147 | return -EINVAL; | |
148 | ||
149 | name = get_name(attr_name, name_index); | |
150 | if (!name) | |
151 | return -ENOMEM; | |
152 | ||
153 | path = btrfs_alloc_path(); | |
154 | if (!path) { | |
155 | kfree(name); | |
156 | return -ENOMEM; | |
157 | } | |
158 | ||
159 | mutex_lock(&root->fs_info->fs_mutex); | |
160 | /* lookup the xattr by name */ | |
161 | di = btrfs_lookup_xattr(NULL, root, path, inode->i_ino, name, | |
162 | strlen(name), 0); | |
163 | if (!di || IS_ERR(di)) { | |
164 | ret = -ENODATA; | |
165 | goto out; | |
166 | } | |
167 | ||
168 | leaf = path->nodes[0]; | |
169 | /* if size is 0, that means we want the size of the attr */ | |
170 | if (!size) { | |
171 | ret = btrfs_dir_data_len(leaf, di); | |
172 | goto out; | |
173 | } | |
174 | ||
175 | /* now get the data out of our dir_item */ | |
176 | if (btrfs_dir_data_len(leaf, di) > size) { | |
177 | ret = -ERANGE; | |
178 | goto out; | |
179 | } | |
180 | data_ptr = (unsigned long)((char *)(di + 1) + | |
181 | btrfs_dir_name_len(leaf, di)); | |
182 | read_extent_buffer(leaf, buffer, data_ptr, | |
3acd7ee8 | 183 | btrfs_dir_data_len(leaf, di)); |
5103e947 JB |
184 | ret = btrfs_dir_data_len(leaf, di); |
185 | ||
186 | out: | |
187 | mutex_unlock(&root->fs_info->fs_mutex); | |
188 | kfree(name); | |
189 | btrfs_free_path(path); | |
190 | return ret; | |
191 | } | |
192 | ||
193 | int btrfs_xattr_set(struct inode *inode, int name_index, | |
194 | const char *attr_name, const void *value, size_t size, | |
195 | int flags) | |
196 | { | |
197 | struct btrfs_dir_item *di; | |
198 | struct btrfs_root *root = BTRFS_I(inode)->root; | |
199 | struct btrfs_trans_handle *trans; | |
200 | struct btrfs_path *path; | |
201 | struct xattr_handler *handler = btrfs_xattr_handler(name_index); | |
202 | char *name; | |
203 | int ret = 0, mod = 0; | |
204 | ||
205 | if (!handler) | |
206 | return -EOPNOTSUPP; | |
207 | ||
208 | /* just in case... */ | |
209 | if (*attr_name == '\0') | |
210 | return -EINVAL; | |
211 | ||
212 | name = get_name(attr_name, name_index); | |
213 | if (!name) | |
214 | return -ENOMEM; | |
215 | ||
216 | path = btrfs_alloc_path(); | |
217 | if (!path) { | |
218 | kfree(name); | |
219 | return -ENOMEM; | |
220 | } | |
221 | ||
222 | mutex_lock(&root->fs_info->fs_mutex); | |
223 | trans = btrfs_start_transaction(root, 1); | |
224 | btrfs_set_trans_block_group(trans, inode); | |
225 | ||
226 | /* first lets see if we already have this xattr */ | |
227 | di = btrfs_lookup_xattr(trans, root, path, inode->i_ino, name, | |
228 | strlen(name), -1); | |
229 | if (IS_ERR(di)) { | |
230 | ret = PTR_ERR(di); | |
231 | goto out; | |
232 | } | |
233 | ||
234 | /* ok we already have this xattr, lets remove it */ | |
235 | if (di) { | |
236 | /* if we want create only exit */ | |
237 | if (flags & XATTR_CREATE) { | |
238 | ret = -EEXIST; | |
239 | goto out; | |
240 | } | |
241 | ||
242 | ret = btrfs_delete_one_dir_name(trans, root, path, di); | |
243 | if (ret) | |
244 | goto out; | |
245 | btrfs_release_path(root, path); | |
246 | ||
247 | /* if we don't have a value then we are removing the xattr */ | |
248 | if (!value) { | |
249 | mod = 1; | |
250 | goto out; | |
251 | } | |
252 | } else if (flags & XATTR_REPLACE) { | |
253 | /* we couldn't find the attr to replace, so error out */ | |
254 | ret = -ENODATA; | |
255 | goto out; | |
256 | } | |
257 | ||
258 | /* ok we have to create a completely new xattr */ | |
259 | ret = btrfs_insert_xattr_item(trans, root, name, strlen(name), | |
260 | value, size, inode->i_ino); | |
261 | if (ret) | |
262 | goto out; | |
263 | mod = 1; | |
264 | ||
265 | out: | |
266 | if (mod) { | |
267 | inode->i_ctime = CURRENT_TIME; | |
268 | ret = btrfs_update_inode(trans, root, inode); | |
269 | } | |
270 | ||
271 | btrfs_end_transaction(trans, root); | |
272 | mutex_unlock(&root->fs_info->fs_mutex); | |
273 | kfree(name); | |
274 | btrfs_free_path(path); | |
275 | ||
276 | return ret; | |
277 | } | |
278 | ||
279 | ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size) | |
280 | { | |
281 | struct btrfs_key key, found_key; | |
282 | struct inode *inode = dentry->d_inode; | |
283 | struct btrfs_root *root = BTRFS_I(inode)->root; | |
284 | struct btrfs_path *path; | |
285 | struct btrfs_item *item; | |
286 | struct extent_buffer *leaf; | |
287 | struct btrfs_dir_item *di; | |
288 | struct xattr_handler *handler; | |
289 | int ret = 0, slot, advance; | |
290 | size_t total_size = 0, size_left = size, written; | |
291 | unsigned long name_ptr; | |
292 | char *name; | |
293 | u32 nritems; | |
294 | ||
295 | /* | |
296 | * ok we want all objects associated with this id. | |
297 | * NOTE: we set key.offset = 0; because we want to start with the | |
298 | * first xattr that we find and walk forward | |
299 | */ | |
300 | key.objectid = inode->i_ino; | |
301 | btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY); | |
302 | key.offset = 0; | |
303 | ||
304 | path = btrfs_alloc_path(); | |
5103e947 JB |
305 | if (!path) |
306 | return -ENOMEM; | |
1caf9342 | 307 | path->reada = 2; |
5103e947 JB |
308 | |
309 | mutex_lock(&root->fs_info->fs_mutex); | |
310 | ||
311 | /* search for our xattrs */ | |
312 | ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); | |
313 | if (ret < 0) | |
314 | goto err; | |
315 | ret = 0; | |
316 | advance = 0; | |
317 | while (1) { | |
318 | leaf = path->nodes[0]; | |
319 | nritems = btrfs_header_nritems(leaf); | |
320 | slot = path->slots[0]; | |
321 | ||
322 | /* this is where we start walking through the path */ | |
323 | if (advance || slot >= nritems) { | |
324 | /* | |
325 | * if we've reached the last slot in this leaf we need | |
326 | * to go to the next leaf and reset everything | |
327 | */ | |
328 | if (slot >= nritems-1) { | |
329 | ret = btrfs_next_leaf(root, path); | |
330 | if (ret) | |
331 | break; | |
332 | leaf = path->nodes[0]; | |
333 | nritems = btrfs_header_nritems(leaf); | |
334 | slot = path->slots[0]; | |
335 | } else { | |
336 | /* | |
337 | * just walking through the slots on this leaf | |
338 | */ | |
339 | slot++; | |
340 | path->slots[0]++; | |
341 | } | |
342 | } | |
343 | advance = 1; | |
344 | ||
345 | item = btrfs_item_nr(leaf, slot); | |
346 | btrfs_item_key_to_cpu(leaf, &found_key, slot); | |
347 | ||
348 | /* check to make sure this item is what we want */ | |
349 | if (found_key.objectid != key.objectid) | |
350 | break; | |
351 | if (btrfs_key_type(&found_key) != BTRFS_XATTR_ITEM_KEY) | |
352 | break; | |
353 | ||
354 | di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); | |
355 | ||
356 | total_size += btrfs_dir_name_len(leaf, di)+1; | |
357 | ||
358 | /* we are just looking for how big our buffer needs to be */ | |
359 | if (!size) | |
360 | continue; | |
361 | ||
362 | /* find our handler for this xattr */ | |
363 | name_ptr = (unsigned long)(di + 1); | |
364 | handler = find_btrfs_xattr_handler(leaf, name_ptr, | |
365 | btrfs_dir_name_len(leaf, di)); | |
366 | if (!handler) { | |
367 | printk(KERN_ERR "btrfs: unsupported xattr found\n"); | |
368 | continue; | |
369 | } | |
370 | ||
371 | name = kmalloc(btrfs_dir_name_len(leaf, di), GFP_KERNEL); | |
372 | read_extent_buffer(leaf, name, name_ptr, | |
373 | btrfs_dir_name_len(leaf, di)); | |
374 | ||
375 | /* call the list function associated with this xattr */ | |
376 | written = handler->list(inode, buffer, size_left, name, | |
377 | btrfs_dir_name_len(leaf, di)); | |
378 | kfree(name); | |
379 | ||
380 | if (written < 0) { | |
381 | ret = -ERANGE; | |
382 | break; | |
383 | } | |
384 | ||
385 | size_left -= written; | |
386 | buffer += written; | |
387 | } | |
388 | ret = total_size; | |
389 | ||
390 | err: | |
391 | mutex_unlock(&root->fs_info->fs_mutex); | |
392 | btrfs_free_path(path); | |
393 | ||
394 | return ret; | |
395 | } | |
396 | ||
397 | /* | |
398 | * delete all the xattrs associated with the inode. fs_mutex should be | |
399 | * held when we come into here | |
400 | */ | |
401 | int btrfs_delete_xattrs(struct btrfs_trans_handle *trans, | |
402 | struct btrfs_root *root, struct inode *inode) | |
403 | { | |
404 | struct btrfs_path *path; | |
405 | struct btrfs_key key, found_key; | |
406 | struct btrfs_item *item; | |
407 | struct extent_buffer *leaf; | |
408 | int ret; | |
409 | ||
410 | path = btrfs_alloc_path(); | |
411 | if (!path) | |
412 | return -ENOMEM; | |
1caf9342 | 413 | path->reada = -1; |
5103e947 JB |
414 | key.objectid = inode->i_ino; |
415 | btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY); | |
416 | key.offset = (u64)-1; | |
417 | ||
418 | while(1) { | |
419 | /* look for our next xattr */ | |
420 | ret = btrfs_search_slot(trans, root, &key, path, -1, 1); | |
421 | if (ret < 0) | |
422 | goto out; | |
423 | BUG_ON(ret == 0); | |
424 | ||
425 | if (path->slots[0] == 0) | |
426 | break; | |
427 | ||
428 | path->slots[0]--; | |
429 | leaf = path->nodes[0]; | |
430 | item = btrfs_item_nr(leaf, path->slots[0]); | |
431 | btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); | |
432 | ||
433 | if (found_key.objectid != key.objectid) | |
434 | break; | |
435 | if (btrfs_key_type(&found_key) != BTRFS_XATTR_ITEM_KEY) | |
436 | break; | |
437 | ||
438 | ret = btrfs_del_item(trans, root, path); | |
439 | BUG_ON(ret); | |
440 | btrfs_release_path(root, path); | |
441 | } | |
442 | ret = 0; | |
443 | out: | |
444 | btrfs_free_path(path); | |
445 | ||
446 | return ret; | |
447 | } | |
448 | ||
449 | /* | |
450 | * Handler functions | |
451 | */ | |
452 | #define BTRFS_XATTR_SETGET_FUNCS(name, index) \ | |
453 | static int btrfs_xattr_##name##_get(struct inode *inode, \ | |
454 | const char *name, void *value, \ | |
455 | size_t size) \ | |
456 | { \ | |
457 | return btrfs_xattr_get(inode, index, name, value, size); \ | |
458 | } \ | |
459 | static int btrfs_xattr_##name##_set(struct inode *inode, \ | |
460 | const char *name, const void *value,\ | |
461 | size_t size, int flags) \ | |
462 | { \ | |
463 | return btrfs_xattr_set(inode, index, name, value, size, flags); \ | |
464 | } \ | |
465 | ||
466 | BTRFS_XATTR_SETGET_FUNCS(security, BTRFS_XATTR_INDEX_SECURITY); | |
467 | BTRFS_XATTR_SETGET_FUNCS(system, BTRFS_XATTR_INDEX_SYSTEM); | |
468 | BTRFS_XATTR_SETGET_FUNCS(user, BTRFS_XATTR_INDEX_USER); | |
469 | BTRFS_XATTR_SETGET_FUNCS(trusted, BTRFS_XATTR_INDEX_TRUSTED); | |
470 | ||
471 | struct xattr_handler btrfs_xattr_security_handler = { | |
472 | .prefix = XATTR_SECURITY_PREFIX, | |
473 | .list = btrfs_xattr_generic_list, | |
474 | .get = btrfs_xattr_security_get, | |
475 | .set = btrfs_xattr_security_set, | |
476 | }; | |
477 | ||
478 | struct xattr_handler btrfs_xattr_system_handler = { | |
479 | .prefix = XATTR_SYSTEM_PREFIX, | |
480 | .list = btrfs_xattr_generic_list, | |
481 | .get = btrfs_xattr_system_get, | |
482 | .set = btrfs_xattr_system_set, | |
483 | }; | |
484 | ||
485 | struct xattr_handler btrfs_xattr_user_handler = { | |
486 | .prefix = XATTR_USER_PREFIX, | |
487 | .list = btrfs_xattr_generic_list, | |
488 | .get = btrfs_xattr_user_get, | |
489 | .set = btrfs_xattr_user_set, | |
490 | }; | |
491 | ||
492 | struct xattr_handler btrfs_xattr_trusted_handler = { | |
3acd7ee8 | 493 | .prefix = XATTR_TRUSTED_PREFIX, |
5103e947 JB |
494 | .list = btrfs_xattr_generic_list, |
495 | .get = btrfs_xattr_trusted_get, | |
496 | .set = btrfs_xattr_trusted_set, | |
497 | }; |