Loading...
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 <linux/security.h>
25#include "ctree.h"
26#include "btrfs_inode.h"
27#include "transaction.h"
28#include "xattr.h"
29#include "disk-io.h"
30
31
32ssize_t __btrfs_getxattr(struct inode *inode, const char *name,
33 void *buffer, size_t size)
34{
35 struct btrfs_dir_item *di;
36 struct btrfs_root *root = BTRFS_I(inode)->root;
37 struct btrfs_path *path;
38 struct extent_buffer *leaf;
39 int ret = 0;
40 unsigned long data_ptr;
41
42 path = btrfs_alloc_path();
43 if (!path)
44 return -ENOMEM;
45
46 /* lookup the xattr by name */
47 di = btrfs_lookup_xattr(NULL, root, path, btrfs_ino(inode), name,
48 strlen(name), 0);
49 if (!di) {
50 ret = -ENODATA;
51 goto out;
52 } else if (IS_ERR(di)) {
53 ret = PTR_ERR(di);
54 goto out;
55 }
56
57 leaf = path->nodes[0];
58 /* if size is 0, that means we want the size of the attr */
59 if (!size) {
60 ret = btrfs_dir_data_len(leaf, di);
61 goto out;
62 }
63
64 /* now get the data out of our dir_item */
65 if (btrfs_dir_data_len(leaf, di) > size) {
66 ret = -ERANGE;
67 goto out;
68 }
69
70 /*
71 * The way things are packed into the leaf is like this
72 * |struct btrfs_dir_item|name|data|
73 * where name is the xattr name, so security.foo, and data is the
74 * content of the xattr. data_ptr points to the location in memory
75 * where the data starts in the in memory leaf
76 */
77 data_ptr = (unsigned long)((char *)(di + 1) +
78 btrfs_dir_name_len(leaf, di));
79 read_extent_buffer(leaf, buffer, data_ptr,
80 btrfs_dir_data_len(leaf, di));
81 ret = btrfs_dir_data_len(leaf, di);
82
83out:
84 btrfs_free_path(path);
85 return ret;
86}
87
88static int do_setxattr(struct btrfs_trans_handle *trans,
89 struct inode *inode, const char *name,
90 const void *value, size_t size, int flags)
91{
92 struct btrfs_dir_item *di;
93 struct btrfs_root *root = BTRFS_I(inode)->root;
94 struct btrfs_path *path;
95 size_t name_len = strlen(name);
96 int ret = 0;
97
98 if (name_len + size > BTRFS_MAX_XATTR_SIZE(root))
99 return -ENOSPC;
100
101 path = btrfs_alloc_path();
102 if (!path)
103 return -ENOMEM;
104
105 if (flags & XATTR_REPLACE) {
106 di = btrfs_lookup_xattr(trans, root, path, btrfs_ino(inode), name,
107 name_len, -1);
108 if (IS_ERR(di)) {
109 ret = PTR_ERR(di);
110 goto out;
111 } else if (!di) {
112 ret = -ENODATA;
113 goto out;
114 }
115 ret = btrfs_delete_one_dir_name(trans, root, path, di);
116 if (ret)
117 goto out;
118 btrfs_release_path(path);
119
120 /*
121 * remove the attribute
122 */
123 if (!value)
124 goto out;
125 }
126
127again:
128 ret = btrfs_insert_xattr_item(trans, root, path, btrfs_ino(inode),
129 name, name_len, value, size);
130 if (ret == -EEXIST) {
131 if (flags & XATTR_CREATE)
132 goto out;
133 /*
134 * We can't use the path we already have since we won't have the
135 * proper locking for a delete, so release the path and
136 * re-lookup to delete the thing.
137 */
138 btrfs_release_path(path);
139 di = btrfs_lookup_xattr(trans, root, path, btrfs_ino(inode),
140 name, name_len, -1);
141 if (IS_ERR(di)) {
142 ret = PTR_ERR(di);
143 goto out;
144 } else if (!di) {
145 /* Shouldn't happen but just in case... */
146 btrfs_release_path(path);
147 goto again;
148 }
149
150 ret = btrfs_delete_one_dir_name(trans, root, path, di);
151 if (ret)
152 goto out;
153
154 /*
155 * We have a value to set, so go back and try to insert it now.
156 */
157 if (value) {
158 btrfs_release_path(path);
159 goto again;
160 }
161 }
162out:
163 btrfs_free_path(path);
164 return ret;
165}
166
167/*
168 * @value: "" makes the attribute to empty, NULL removes it
169 */
170int __btrfs_setxattr(struct btrfs_trans_handle *trans,
171 struct inode *inode, const char *name,
172 const void *value, size_t size, int flags)
173{
174 struct btrfs_root *root = BTRFS_I(inode)->root;
175 int ret;
176
177 if (trans)
178 return do_setxattr(trans, inode, name, value, size, flags);
179
180 trans = btrfs_start_transaction(root, 2);
181 if (IS_ERR(trans))
182 return PTR_ERR(trans);
183
184 ret = do_setxattr(trans, inode, name, value, size, flags);
185 if (ret)
186 goto out;
187
188 inode->i_ctime = CURRENT_TIME;
189 ret = btrfs_update_inode(trans, root, inode);
190 BUG_ON(ret);
191out:
192 btrfs_end_transaction_throttle(trans, root);
193 return ret;
194}
195
196ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
197{
198 struct btrfs_key key, found_key;
199 struct inode *inode = dentry->d_inode;
200 struct btrfs_root *root = BTRFS_I(inode)->root;
201 struct btrfs_path *path;
202 struct extent_buffer *leaf;
203 struct btrfs_dir_item *di;
204 int ret = 0, slot;
205 size_t total_size = 0, size_left = size;
206 unsigned long name_ptr;
207 size_t name_len;
208
209 /*
210 * ok we want all objects associated with this id.
211 * NOTE: we set key.offset = 0; because we want to start with the
212 * first xattr that we find and walk forward
213 */
214 key.objectid = btrfs_ino(inode);
215 btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
216 key.offset = 0;
217
218 path = btrfs_alloc_path();
219 if (!path)
220 return -ENOMEM;
221 path->reada = 2;
222
223 /* search for our xattrs */
224 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
225 if (ret < 0)
226 goto err;
227
228 while (1) {
229 leaf = path->nodes[0];
230 slot = path->slots[0];
231
232 /* this is where we start walking through the path */
233 if (slot >= btrfs_header_nritems(leaf)) {
234 /*
235 * if we've reached the last slot in this leaf we need
236 * to go to the next leaf and reset everything
237 */
238 ret = btrfs_next_leaf(root, path);
239 if (ret < 0)
240 goto err;
241 else if (ret > 0)
242 break;
243 continue;
244 }
245
246 btrfs_item_key_to_cpu(leaf, &found_key, slot);
247
248 /* check to make sure this item is what we want */
249 if (found_key.objectid != key.objectid)
250 break;
251 if (btrfs_key_type(&found_key) != BTRFS_XATTR_ITEM_KEY)
252 break;
253
254 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
255 if (verify_dir_item(root, leaf, di))
256 continue;
257
258 name_len = btrfs_dir_name_len(leaf, di);
259 total_size += name_len + 1;
260
261 /* we are just looking for how big our buffer needs to be */
262 if (!size)
263 goto next;
264
265 if (!buffer || (name_len + 1) > size_left) {
266 ret = -ERANGE;
267 goto err;
268 }
269
270 name_ptr = (unsigned long)(di + 1);
271 read_extent_buffer(leaf, buffer, name_ptr, name_len);
272 buffer[name_len] = '\0';
273
274 size_left -= name_len + 1;
275 buffer += name_len + 1;
276next:
277 path->slots[0]++;
278 }
279 ret = total_size;
280
281err:
282 btrfs_free_path(path);
283
284 return ret;
285}
286
287/*
288 * List of handlers for synthetic system.* attributes. All real ondisk
289 * attributes are handled directly.
290 */
291const struct xattr_handler *btrfs_xattr_handlers[] = {
292#ifdef CONFIG_BTRFS_FS_POSIX_ACL
293 &btrfs_xattr_acl_access_handler,
294 &btrfs_xattr_acl_default_handler,
295#endif
296 NULL,
297};
298
299/*
300 * Check if the attribute is in a supported namespace.
301 *
302 * This applied after the check for the synthetic attributes in the system
303 * namespace.
304 */
305static bool btrfs_is_valid_xattr(const char *name)
306{
307 return !strncmp(name, XATTR_SECURITY_PREFIX,
308 XATTR_SECURITY_PREFIX_LEN) ||
309 !strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) ||
310 !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) ||
311 !strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
312}
313
314ssize_t btrfs_getxattr(struct dentry *dentry, const char *name,
315 void *buffer, size_t size)
316{
317 /*
318 * If this is a request for a synthetic attribute in the system.*
319 * namespace use the generic infrastructure to resolve a handler
320 * for it via sb->s_xattr.
321 */
322 if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
323 return generic_getxattr(dentry, name, buffer, size);
324
325 if (!btrfs_is_valid_xattr(name))
326 return -EOPNOTSUPP;
327 return __btrfs_getxattr(dentry->d_inode, name, buffer, size);
328}
329
330int btrfs_setxattr(struct dentry *dentry, const char *name, const void *value,
331 size_t size, int flags)
332{
333 struct btrfs_root *root = BTRFS_I(dentry->d_inode)->root;
334
335 /*
336 * The permission on security.* and system.* is not checked
337 * in permission().
338 */
339 if (btrfs_root_readonly(root))
340 return -EROFS;
341
342 /*
343 * If this is a request for a synthetic attribute in the system.*
344 * namespace use the generic infrastructure to resolve a handler
345 * for it via sb->s_xattr.
346 */
347 if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
348 return generic_setxattr(dentry, name, value, size, flags);
349
350 if (!btrfs_is_valid_xattr(name))
351 return -EOPNOTSUPP;
352
353 if (size == 0)
354 value = ""; /* empty EA, do not remove */
355
356 return __btrfs_setxattr(NULL, dentry->d_inode, name, value, size,
357 flags);
358}
359
360int btrfs_removexattr(struct dentry *dentry, const char *name)
361{
362 struct btrfs_root *root = BTRFS_I(dentry->d_inode)->root;
363
364 /*
365 * The permission on security.* and system.* is not checked
366 * in permission().
367 */
368 if (btrfs_root_readonly(root))
369 return -EROFS;
370
371 /*
372 * If this is a request for a synthetic attribute in the system.*
373 * namespace use the generic infrastructure to resolve a handler
374 * for it via sb->s_xattr.
375 */
376 if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
377 return generic_removexattr(dentry, name);
378
379 if (!btrfs_is_valid_xattr(name))
380 return -EOPNOTSUPP;
381
382 return __btrfs_setxattr(NULL, dentry->d_inode, name, NULL, 0,
383 XATTR_REPLACE);
384}
385
386int btrfs_xattr_security_init(struct btrfs_trans_handle *trans,
387 struct inode *inode, struct inode *dir,
388 const struct qstr *qstr)
389{
390 int err;
391 size_t len;
392 void *value;
393 char *suffix;
394 char *name;
395
396 err = security_inode_init_security(inode, dir, qstr, &suffix, &value,
397 &len);
398 if (err) {
399 if (err == -EOPNOTSUPP)
400 return 0;
401 return err;
402 }
403
404 name = kmalloc(XATTR_SECURITY_PREFIX_LEN + strlen(suffix) + 1,
405 GFP_NOFS);
406 if (!name) {
407 err = -ENOMEM;
408 } else {
409 strcpy(name, XATTR_SECURITY_PREFIX);
410 strcpy(name + XATTR_SECURITY_PREFIX_LEN, suffix);
411 err = __btrfs_setxattr(trans, inode, name, value, len, 0);
412 kfree(name);
413 }
414
415 kfree(suffix);
416 kfree(value);
417 return err;
418}
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 <linux/security.h>
25#include "ctree.h"
26#include "btrfs_inode.h"
27#include "transaction.h"
28#include "xattr.h"
29#include "disk-io.h"
30
31
32ssize_t __btrfs_getxattr(struct inode *inode, const char *name,
33 void *buffer, size_t size)
34{
35 struct btrfs_dir_item *di;
36 struct btrfs_root *root = BTRFS_I(inode)->root;
37 struct btrfs_path *path;
38 struct extent_buffer *leaf;
39 int ret = 0;
40 unsigned long data_ptr;
41
42 path = btrfs_alloc_path();
43 if (!path)
44 return -ENOMEM;
45
46 /* lookup the xattr by name */
47 di = btrfs_lookup_xattr(NULL, root, path, btrfs_ino(inode), name,
48 strlen(name), 0);
49 if (!di) {
50 ret = -ENODATA;
51 goto out;
52 } else if (IS_ERR(di)) {
53 ret = PTR_ERR(di);
54 goto out;
55 }
56
57 leaf = path->nodes[0];
58 /* if size is 0, that means we want the size of the attr */
59 if (!size) {
60 ret = btrfs_dir_data_len(leaf, di);
61 goto out;
62 }
63
64 /* now get the data out of our dir_item */
65 if (btrfs_dir_data_len(leaf, di) > size) {
66 ret = -ERANGE;
67 goto out;
68 }
69
70 /*
71 * The way things are packed into the leaf is like this
72 * |struct btrfs_dir_item|name|data|
73 * where name is the xattr name, so security.foo, and data is the
74 * content of the xattr. data_ptr points to the location in memory
75 * where the data starts in the in memory leaf
76 */
77 data_ptr = (unsigned long)((char *)(di + 1) +
78 btrfs_dir_name_len(leaf, di));
79 read_extent_buffer(leaf, buffer, data_ptr,
80 btrfs_dir_data_len(leaf, di));
81 ret = btrfs_dir_data_len(leaf, di);
82
83out:
84 btrfs_free_path(path);
85 return ret;
86}
87
88static int do_setxattr(struct btrfs_trans_handle *trans,
89 struct inode *inode, const char *name,
90 const void *value, size_t size, int flags)
91{
92 struct btrfs_dir_item *di;
93 struct btrfs_root *root = BTRFS_I(inode)->root;
94 struct btrfs_path *path;
95 size_t name_len = strlen(name);
96 int ret = 0;
97
98 if (name_len + size > BTRFS_MAX_XATTR_SIZE(root))
99 return -ENOSPC;
100
101 path = btrfs_alloc_path();
102 if (!path)
103 return -ENOMEM;
104
105 if (flags & XATTR_REPLACE) {
106 di = btrfs_lookup_xattr(trans, root, path, btrfs_ino(inode), name,
107 name_len, -1);
108 if (IS_ERR(di)) {
109 ret = PTR_ERR(di);
110 goto out;
111 } else if (!di) {
112 ret = -ENODATA;
113 goto out;
114 }
115 ret = btrfs_delete_one_dir_name(trans, root, path, di);
116 if (ret)
117 goto out;
118 btrfs_release_path(path);
119
120 /*
121 * remove the attribute
122 */
123 if (!value)
124 goto out;
125 }
126
127again:
128 ret = btrfs_insert_xattr_item(trans, root, path, btrfs_ino(inode),
129 name, name_len, value, size);
130 /*
131 * If we're setting an xattr to a new value but the new value is say
132 * exactly BTRFS_MAX_XATTR_SIZE, we could end up with EOVERFLOW getting
133 * back from split_leaf. This is because it thinks we'll be extending
134 * the existing item size, but we're asking for enough space to add the
135 * item itself. So if we get EOVERFLOW just set ret to EEXIST and let
136 * the rest of the function figure it out.
137 */
138 if (ret == -EOVERFLOW)
139 ret = -EEXIST;
140
141 if (ret == -EEXIST) {
142 if (flags & XATTR_CREATE)
143 goto out;
144 /*
145 * We can't use the path we already have since we won't have the
146 * proper locking for a delete, so release the path and
147 * re-lookup to delete the thing.
148 */
149 btrfs_release_path(path);
150 di = btrfs_lookup_xattr(trans, root, path, btrfs_ino(inode),
151 name, name_len, -1);
152 if (IS_ERR(di)) {
153 ret = PTR_ERR(di);
154 goto out;
155 } else if (!di) {
156 /* Shouldn't happen but just in case... */
157 btrfs_release_path(path);
158 goto again;
159 }
160
161 ret = btrfs_delete_one_dir_name(trans, root, path, di);
162 if (ret)
163 goto out;
164
165 /*
166 * We have a value to set, so go back and try to insert it now.
167 */
168 if (value) {
169 btrfs_release_path(path);
170 goto again;
171 }
172 }
173out:
174 btrfs_free_path(path);
175 return ret;
176}
177
178/*
179 * @value: "" makes the attribute to empty, NULL removes it
180 */
181int __btrfs_setxattr(struct btrfs_trans_handle *trans,
182 struct inode *inode, const char *name,
183 const void *value, size_t size, int flags)
184{
185 struct btrfs_root *root = BTRFS_I(inode)->root;
186 int ret;
187
188 if (trans)
189 return do_setxattr(trans, inode, name, value, size, flags);
190
191 trans = btrfs_start_transaction(root, 2);
192 if (IS_ERR(trans))
193 return PTR_ERR(trans);
194
195 ret = do_setxattr(trans, inode, name, value, size, flags);
196 if (ret)
197 goto out;
198
199 inode_inc_iversion(inode);
200 inode->i_ctime = CURRENT_TIME;
201 ret = btrfs_update_inode(trans, root, inode);
202 BUG_ON(ret);
203out:
204 btrfs_end_transaction(trans, root);
205 return ret;
206}
207
208ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
209{
210 struct btrfs_key key, found_key;
211 struct inode *inode = dentry->d_inode;
212 struct btrfs_root *root = BTRFS_I(inode)->root;
213 struct btrfs_path *path;
214 struct extent_buffer *leaf;
215 struct btrfs_dir_item *di;
216 int ret = 0, slot;
217 size_t total_size = 0, size_left = size;
218 unsigned long name_ptr;
219 size_t name_len;
220
221 /*
222 * ok we want all objects associated with this id.
223 * NOTE: we set key.offset = 0; because we want to start with the
224 * first xattr that we find and walk forward
225 */
226 key.objectid = btrfs_ino(inode);
227 btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
228 key.offset = 0;
229
230 path = btrfs_alloc_path();
231 if (!path)
232 return -ENOMEM;
233 path->reada = 2;
234
235 /* search for our xattrs */
236 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
237 if (ret < 0)
238 goto err;
239
240 while (1) {
241 leaf = path->nodes[0];
242 slot = path->slots[0];
243
244 /* this is where we start walking through the path */
245 if (slot >= btrfs_header_nritems(leaf)) {
246 /*
247 * if we've reached the last slot in this leaf we need
248 * to go to the next leaf and reset everything
249 */
250 ret = btrfs_next_leaf(root, path);
251 if (ret < 0)
252 goto err;
253 else if (ret > 0)
254 break;
255 continue;
256 }
257
258 btrfs_item_key_to_cpu(leaf, &found_key, slot);
259
260 /* check to make sure this item is what we want */
261 if (found_key.objectid != key.objectid)
262 break;
263 if (btrfs_key_type(&found_key) != BTRFS_XATTR_ITEM_KEY)
264 break;
265
266 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
267 if (verify_dir_item(root, leaf, di))
268 continue;
269
270 name_len = btrfs_dir_name_len(leaf, di);
271 total_size += name_len + 1;
272
273 /* we are just looking for how big our buffer needs to be */
274 if (!size)
275 goto next;
276
277 if (!buffer || (name_len + 1) > size_left) {
278 ret = -ERANGE;
279 goto err;
280 }
281
282 name_ptr = (unsigned long)(di + 1);
283 read_extent_buffer(leaf, buffer, name_ptr, name_len);
284 buffer[name_len] = '\0';
285
286 size_left -= name_len + 1;
287 buffer += name_len + 1;
288next:
289 path->slots[0]++;
290 }
291 ret = total_size;
292
293err:
294 btrfs_free_path(path);
295
296 return ret;
297}
298
299/*
300 * List of handlers for synthetic system.* attributes. All real ondisk
301 * attributes are handled directly.
302 */
303const struct xattr_handler *btrfs_xattr_handlers[] = {
304#ifdef CONFIG_BTRFS_FS_POSIX_ACL
305 &btrfs_xattr_acl_access_handler,
306 &btrfs_xattr_acl_default_handler,
307#endif
308 NULL,
309};
310
311/*
312 * Check if the attribute is in a supported namespace.
313 *
314 * This applied after the check for the synthetic attributes in the system
315 * namespace.
316 */
317static bool btrfs_is_valid_xattr(const char *name)
318{
319 return !strncmp(name, XATTR_SECURITY_PREFIX,
320 XATTR_SECURITY_PREFIX_LEN) ||
321 !strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) ||
322 !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) ||
323 !strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
324}
325
326ssize_t btrfs_getxattr(struct dentry *dentry, const char *name,
327 void *buffer, size_t size)
328{
329 /*
330 * If this is a request for a synthetic attribute in the system.*
331 * namespace use the generic infrastructure to resolve a handler
332 * for it via sb->s_xattr.
333 */
334 if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
335 return generic_getxattr(dentry, name, buffer, size);
336
337 if (!btrfs_is_valid_xattr(name))
338 return -EOPNOTSUPP;
339 return __btrfs_getxattr(dentry->d_inode, name, buffer, size);
340}
341
342int btrfs_setxattr(struct dentry *dentry, const char *name, const void *value,
343 size_t size, int flags)
344{
345 struct btrfs_root *root = BTRFS_I(dentry->d_inode)->root;
346
347 /*
348 * The permission on security.* and system.* is not checked
349 * in permission().
350 */
351 if (btrfs_root_readonly(root))
352 return -EROFS;
353
354 /*
355 * If this is a request for a synthetic attribute in the system.*
356 * namespace use the generic infrastructure to resolve a handler
357 * for it via sb->s_xattr.
358 */
359 if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
360 return generic_setxattr(dentry, name, value, size, flags);
361
362 if (!btrfs_is_valid_xattr(name))
363 return -EOPNOTSUPP;
364
365 if (size == 0)
366 value = ""; /* empty EA, do not remove */
367
368 return __btrfs_setxattr(NULL, dentry->d_inode, name, value, size,
369 flags);
370}
371
372int btrfs_removexattr(struct dentry *dentry, const char *name)
373{
374 struct btrfs_root *root = BTRFS_I(dentry->d_inode)->root;
375
376 /*
377 * The permission on security.* and system.* is not checked
378 * in permission().
379 */
380 if (btrfs_root_readonly(root))
381 return -EROFS;
382
383 /*
384 * If this is a request for a synthetic attribute in the system.*
385 * namespace use the generic infrastructure to resolve a handler
386 * for it via sb->s_xattr.
387 */
388 if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
389 return generic_removexattr(dentry, name);
390
391 if (!btrfs_is_valid_xattr(name))
392 return -EOPNOTSUPP;
393
394 return __btrfs_setxattr(NULL, dentry->d_inode, name, NULL, 0,
395 XATTR_REPLACE);
396}
397
398int btrfs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
399 void *fs_info)
400{
401 const struct xattr *xattr;
402 struct btrfs_trans_handle *trans = fs_info;
403 char *name;
404 int err = 0;
405
406 for (xattr = xattr_array; xattr->name != NULL; xattr++) {
407 name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
408 strlen(xattr->name) + 1, GFP_NOFS);
409 if (!name) {
410 err = -ENOMEM;
411 break;
412 }
413 strcpy(name, XATTR_SECURITY_PREFIX);
414 strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
415 err = __btrfs_setxattr(trans, inode, name,
416 xattr->value, xattr->value_len, 0);
417 kfree(name);
418 if (err < 0)
419 break;
420 }
421 return err;
422}
423
424int btrfs_xattr_security_init(struct btrfs_trans_handle *trans,
425 struct inode *inode, struct inode *dir,
426 const struct qstr *qstr)
427{
428 return security_inode_init_security(inode, dir, qstr,
429 &btrfs_initxattrs, trans);
430}