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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}
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 <linux/posix_acl_xattr.h>
26#include "ctree.h"
27#include "btrfs_inode.h"
28#include "transaction.h"
29#include "xattr.h"
30#include "disk-io.h"
31#include "props.h"
32#include "locking.h"
33
34
35ssize_t __btrfs_getxattr(struct inode *inode, const char *name,
36 void *buffer, size_t size)
37{
38 struct btrfs_dir_item *di;
39 struct btrfs_root *root = BTRFS_I(inode)->root;
40 struct btrfs_path *path;
41 struct extent_buffer *leaf;
42 int ret = 0;
43 unsigned long data_ptr;
44
45 path = btrfs_alloc_path();
46 if (!path)
47 return -ENOMEM;
48
49 /* lookup the xattr by name */
50 di = btrfs_lookup_xattr(NULL, root, path, btrfs_ino(inode), name,
51 strlen(name), 0);
52 if (!di) {
53 ret = -ENODATA;
54 goto out;
55 } else if (IS_ERR(di)) {
56 ret = PTR_ERR(di);
57 goto out;
58 }
59
60 leaf = path->nodes[0];
61 /* if size is 0, that means we want the size of the attr */
62 if (!size) {
63 ret = btrfs_dir_data_len(leaf, di);
64 goto out;
65 }
66
67 /* now get the data out of our dir_item */
68 if (btrfs_dir_data_len(leaf, di) > size) {
69 ret = -ERANGE;
70 goto out;
71 }
72
73 /*
74 * The way things are packed into the leaf is like this
75 * |struct btrfs_dir_item|name|data|
76 * where name is the xattr name, so security.foo, and data is the
77 * content of the xattr. data_ptr points to the location in memory
78 * where the data starts in the in memory leaf
79 */
80 data_ptr = (unsigned long)((char *)(di + 1) +
81 btrfs_dir_name_len(leaf, di));
82 read_extent_buffer(leaf, buffer, data_ptr,
83 btrfs_dir_data_len(leaf, di));
84 ret = btrfs_dir_data_len(leaf, di);
85
86out:
87 btrfs_free_path(path);
88 return ret;
89}
90
91static int do_setxattr(struct btrfs_trans_handle *trans,
92 struct inode *inode, const char *name,
93 const void *value, size_t size, int flags)
94{
95 struct btrfs_dir_item *di = NULL;
96 struct btrfs_root *root = BTRFS_I(inode)->root;
97 struct btrfs_path *path;
98 size_t name_len = strlen(name);
99 int ret = 0;
100
101 if (name_len + size > BTRFS_MAX_XATTR_SIZE(root))
102 return -ENOSPC;
103
104 path = btrfs_alloc_path();
105 if (!path)
106 return -ENOMEM;
107 path->skip_release_on_error = 1;
108
109 if (!value) {
110 di = btrfs_lookup_xattr(trans, root, path, btrfs_ino(inode),
111 name, name_len, -1);
112 if (!di && (flags & XATTR_REPLACE))
113 ret = -ENODATA;
114 else if (IS_ERR(di))
115 ret = PTR_ERR(di);
116 else if (di)
117 ret = btrfs_delete_one_dir_name(trans, root, path, di);
118 goto out;
119 }
120
121 /*
122 * For a replace we can't just do the insert blindly.
123 * Do a lookup first (read-only btrfs_search_slot), and return if xattr
124 * doesn't exist. If it exists, fall down below to the insert/replace
125 * path - we can't race with a concurrent xattr delete, because the VFS
126 * locks the inode's i_mutex before calling setxattr or removexattr.
127 */
128 if (flags & XATTR_REPLACE) {
129 ASSERT(inode_is_locked(inode));
130 di = btrfs_lookup_xattr(NULL, root, path, btrfs_ino(inode),
131 name, name_len, 0);
132 if (!di)
133 ret = -ENODATA;
134 else if (IS_ERR(di))
135 ret = PTR_ERR(di);
136 if (ret)
137 goto out;
138 btrfs_release_path(path);
139 di = NULL;
140 }
141
142 ret = btrfs_insert_xattr_item(trans, root, path, btrfs_ino(inode),
143 name, name_len, value, size);
144 if (ret == -EOVERFLOW) {
145 /*
146 * We have an existing item in a leaf, split_leaf couldn't
147 * expand it. That item might have or not a dir_item that
148 * matches our target xattr, so lets check.
149 */
150 ret = 0;
151 btrfs_assert_tree_locked(path->nodes[0]);
152 di = btrfs_match_dir_item_name(root, path, name, name_len);
153 if (!di && !(flags & XATTR_REPLACE)) {
154 ret = -ENOSPC;
155 goto out;
156 }
157 } else if (ret == -EEXIST) {
158 ret = 0;
159 di = btrfs_match_dir_item_name(root, path, name, name_len);
160 ASSERT(di); /* logic error */
161 } else if (ret) {
162 goto out;
163 }
164
165 if (di && (flags & XATTR_CREATE)) {
166 ret = -EEXIST;
167 goto out;
168 }
169
170 if (di) {
171 /*
172 * We're doing a replace, and it must be atomic, that is, at
173 * any point in time we have either the old or the new xattr
174 * value in the tree. We don't want readers (getxattr and
175 * listxattrs) to miss a value, this is specially important
176 * for ACLs.
177 */
178 const int slot = path->slots[0];
179 struct extent_buffer *leaf = path->nodes[0];
180 const u16 old_data_len = btrfs_dir_data_len(leaf, di);
181 const u32 item_size = btrfs_item_size_nr(leaf, slot);
182 const u32 data_size = sizeof(*di) + name_len + size;
183 struct btrfs_item *item;
184 unsigned long data_ptr;
185 char *ptr;
186
187 if (size > old_data_len) {
188 if (btrfs_leaf_free_space(root, leaf) <
189 (size - old_data_len)) {
190 ret = -ENOSPC;
191 goto out;
192 }
193 }
194
195 if (old_data_len + name_len + sizeof(*di) == item_size) {
196 /* No other xattrs packed in the same leaf item. */
197 if (size > old_data_len)
198 btrfs_extend_item(root, path,
199 size - old_data_len);
200 else if (size < old_data_len)
201 btrfs_truncate_item(root, path, data_size, 1);
202 } else {
203 /* There are other xattrs packed in the same item. */
204 ret = btrfs_delete_one_dir_name(trans, root, path, di);
205 if (ret)
206 goto out;
207 btrfs_extend_item(root, path, data_size);
208 }
209
210 item = btrfs_item_nr(slot);
211 ptr = btrfs_item_ptr(leaf, slot, char);
212 ptr += btrfs_item_size(leaf, item) - data_size;
213 di = (struct btrfs_dir_item *)ptr;
214 btrfs_set_dir_data_len(leaf, di, size);
215 data_ptr = ((unsigned long)(di + 1)) + name_len;
216 write_extent_buffer(leaf, value, data_ptr, size);
217 btrfs_mark_buffer_dirty(leaf);
218 } else {
219 /*
220 * Insert, and we had space for the xattr, so path->slots[0] is
221 * where our xattr dir_item is and btrfs_insert_xattr_item()
222 * filled it.
223 */
224 }
225out:
226 btrfs_free_path(path);
227 return ret;
228}
229
230/*
231 * @value: "" makes the attribute to empty, NULL removes it
232 */
233int __btrfs_setxattr(struct btrfs_trans_handle *trans,
234 struct inode *inode, const char *name,
235 const void *value, size_t size, int flags)
236{
237 struct btrfs_root *root = BTRFS_I(inode)->root;
238 int ret;
239
240 if (trans)
241 return do_setxattr(trans, inode, name, value, size, flags);
242
243 trans = btrfs_start_transaction(root, 2);
244 if (IS_ERR(trans))
245 return PTR_ERR(trans);
246
247 ret = do_setxattr(trans, inode, name, value, size, flags);
248 if (ret)
249 goto out;
250
251 inode_inc_iversion(inode);
252 inode->i_ctime = current_fs_time(inode->i_sb);
253 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
254 ret = btrfs_update_inode(trans, root, inode);
255 BUG_ON(ret);
256out:
257 btrfs_end_transaction(trans, root);
258 return ret;
259}
260
261ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
262{
263 struct btrfs_key key;
264 struct inode *inode = d_inode(dentry);
265 struct btrfs_root *root = BTRFS_I(inode)->root;
266 struct btrfs_path *path;
267 int ret = 0;
268 size_t total_size = 0, size_left = size;
269
270 /*
271 * ok we want all objects associated with this id.
272 * NOTE: we set key.offset = 0; because we want to start with the
273 * first xattr that we find and walk forward
274 */
275 key.objectid = btrfs_ino(inode);
276 key.type = BTRFS_XATTR_ITEM_KEY;
277 key.offset = 0;
278
279 path = btrfs_alloc_path();
280 if (!path)
281 return -ENOMEM;
282 path->reada = READA_FORWARD;
283
284 /* search for our xattrs */
285 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
286 if (ret < 0)
287 goto err;
288
289 while (1) {
290 struct extent_buffer *leaf;
291 int slot;
292 struct btrfs_dir_item *di;
293 struct btrfs_key found_key;
294 u32 item_size;
295 u32 cur;
296
297 leaf = path->nodes[0];
298 slot = path->slots[0];
299
300 /* this is where we start walking through the path */
301 if (slot >= btrfs_header_nritems(leaf)) {
302 /*
303 * if we've reached the last slot in this leaf we need
304 * to go to the next leaf and reset everything
305 */
306 ret = btrfs_next_leaf(root, path);
307 if (ret < 0)
308 goto err;
309 else if (ret > 0)
310 break;
311 continue;
312 }
313
314 btrfs_item_key_to_cpu(leaf, &found_key, slot);
315
316 /* check to make sure this item is what we want */
317 if (found_key.objectid != key.objectid)
318 break;
319 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
320 break;
321 if (found_key.type < BTRFS_XATTR_ITEM_KEY)
322 goto next_item;
323
324 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
325 item_size = btrfs_item_size_nr(leaf, slot);
326 cur = 0;
327 while (cur < item_size) {
328 u16 name_len = btrfs_dir_name_len(leaf, di);
329 u16 data_len = btrfs_dir_data_len(leaf, di);
330 u32 this_len = sizeof(*di) + name_len + data_len;
331 unsigned long name_ptr = (unsigned long)(di + 1);
332
333 if (verify_dir_item(root, leaf, di)) {
334 ret = -EIO;
335 goto err;
336 }
337
338 total_size += name_len + 1;
339 /*
340 * We are just looking for how big our buffer needs to
341 * be.
342 */
343 if (!size)
344 goto next;
345
346 if (!buffer || (name_len + 1) > size_left) {
347 ret = -ERANGE;
348 goto err;
349 }
350
351 read_extent_buffer(leaf, buffer, name_ptr, name_len);
352 buffer[name_len] = '\0';
353
354 size_left -= name_len + 1;
355 buffer += name_len + 1;
356next:
357 cur += this_len;
358 di = (struct btrfs_dir_item *)((char *)di + this_len);
359 }
360next_item:
361 path->slots[0]++;
362 }
363 ret = total_size;
364
365err:
366 btrfs_free_path(path);
367
368 return ret;
369}
370
371static int btrfs_xattr_handler_get(const struct xattr_handler *handler,
372 struct dentry *dentry, const char *name,
373 void *buffer, size_t size)
374{
375 struct inode *inode = d_inode(dentry);
376
377 name = xattr_full_name(handler, name);
378 return __btrfs_getxattr(inode, name, buffer, size);
379}
380
381static int btrfs_xattr_handler_set(const struct xattr_handler *handler,
382 struct dentry *dentry, const char *name,
383 const void *buffer, size_t size,
384 int flags)
385{
386 struct inode *inode = d_inode(dentry);
387
388 name = xattr_full_name(handler, name);
389 return __btrfs_setxattr(NULL, inode, name, buffer, size, flags);
390}
391
392static int btrfs_xattr_handler_set_prop(const struct xattr_handler *handler,
393 struct dentry *dentry,
394 const char *name, const void *value,
395 size_t size, int flags)
396{
397 name = xattr_full_name(handler, name);
398 return btrfs_set_prop(d_inode(dentry), name, value, size, flags);
399}
400
401static const struct xattr_handler btrfs_security_xattr_handler = {
402 .prefix = XATTR_SECURITY_PREFIX,
403 .get = btrfs_xattr_handler_get,
404 .set = btrfs_xattr_handler_set,
405};
406
407static const struct xattr_handler btrfs_trusted_xattr_handler = {
408 .prefix = XATTR_TRUSTED_PREFIX,
409 .get = btrfs_xattr_handler_get,
410 .set = btrfs_xattr_handler_set,
411};
412
413static const struct xattr_handler btrfs_user_xattr_handler = {
414 .prefix = XATTR_USER_PREFIX,
415 .get = btrfs_xattr_handler_get,
416 .set = btrfs_xattr_handler_set,
417};
418
419static const struct xattr_handler btrfs_btrfs_xattr_handler = {
420 .prefix = XATTR_BTRFS_PREFIX,
421 .get = btrfs_xattr_handler_get,
422 .set = btrfs_xattr_handler_set_prop,
423};
424
425const struct xattr_handler *btrfs_xattr_handlers[] = {
426 &btrfs_security_xattr_handler,
427#ifdef CONFIG_BTRFS_FS_POSIX_ACL
428 &posix_acl_access_xattr_handler,
429 &posix_acl_default_xattr_handler,
430#endif
431 &btrfs_trusted_xattr_handler,
432 &btrfs_user_xattr_handler,
433 &btrfs_btrfs_xattr_handler,
434 NULL,
435};
436
437int btrfs_setxattr(struct dentry *dentry, const char *name, const void *value,
438 size_t size, int flags)
439{
440 struct btrfs_root *root = BTRFS_I(d_inode(dentry))->root;
441
442 if (btrfs_root_readonly(root))
443 return -EROFS;
444 return generic_setxattr(dentry, name, value, size, flags);
445}
446
447int btrfs_removexattr(struct dentry *dentry, const char *name)
448{
449 struct btrfs_root *root = BTRFS_I(d_inode(dentry))->root;
450
451 if (btrfs_root_readonly(root))
452 return -EROFS;
453 return generic_removexattr(dentry, name);
454}
455
456static int btrfs_initxattrs(struct inode *inode,
457 const struct xattr *xattr_array, void *fs_info)
458{
459 const struct xattr *xattr;
460 struct btrfs_trans_handle *trans = fs_info;
461 char *name;
462 int err = 0;
463
464 for (xattr = xattr_array; xattr->name != NULL; xattr++) {
465 name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
466 strlen(xattr->name) + 1, GFP_KERNEL);
467 if (!name) {
468 err = -ENOMEM;
469 break;
470 }
471 strcpy(name, XATTR_SECURITY_PREFIX);
472 strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
473 err = __btrfs_setxattr(trans, inode, name,
474 xattr->value, xattr->value_len, 0);
475 kfree(name);
476 if (err < 0)
477 break;
478 }
479 return err;
480}
481
482int btrfs_xattr_security_init(struct btrfs_trans_handle *trans,
483 struct inode *inode, struct inode *dir,
484 const struct qstr *qstr)
485{
486 return security_inode_init_security(inode, dir, qstr,
487 &btrfs_initxattrs, trans);
488}