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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2007 Red Hat. All rights reserved.
4 */
5
6#include <linux/init.h>
7#include <linux/fs.h>
8#include <linux/slab.h>
9#include <linux/rwsem.h>
10#include <linux/xattr.h>
11#include <linux/security.h>
12#include <linux/posix_acl_xattr.h>
13#include <linux/iversion.h>
14#include "ctree.h"
15#include "btrfs_inode.h"
16#include "transaction.h"
17#include "xattr.h"
18#include "disk-io.h"
19#include "props.h"
20#include "locking.h"
21
22int btrfs_getxattr(struct inode *inode, const char *name,
23 void *buffer, size_t size)
24{
25 struct btrfs_dir_item *di;
26 struct btrfs_root *root = BTRFS_I(inode)->root;
27 struct btrfs_path *path;
28 struct extent_buffer *leaf;
29 int ret = 0;
30 unsigned long data_ptr;
31
32 path = btrfs_alloc_path();
33 if (!path)
34 return -ENOMEM;
35
36 /* lookup the xattr by name */
37 di = btrfs_lookup_xattr(NULL, root, path, btrfs_ino(BTRFS_I(inode)),
38 name, strlen(name), 0);
39 if (!di) {
40 ret = -ENODATA;
41 goto out;
42 } else if (IS_ERR(di)) {
43 ret = PTR_ERR(di);
44 goto out;
45 }
46
47 leaf = path->nodes[0];
48 /* if size is 0, that means we want the size of the attr */
49 if (!size) {
50 ret = btrfs_dir_data_len(leaf, di);
51 goto out;
52 }
53
54 /* now get the data out of our dir_item */
55 if (btrfs_dir_data_len(leaf, di) > size) {
56 ret = -ERANGE;
57 goto out;
58 }
59
60 /*
61 * The way things are packed into the leaf is like this
62 * |struct btrfs_dir_item|name|data|
63 * where name is the xattr name, so security.foo, and data is the
64 * content of the xattr. data_ptr points to the location in memory
65 * where the data starts in the in memory leaf
66 */
67 data_ptr = (unsigned long)((char *)(di + 1) +
68 btrfs_dir_name_len(leaf, di));
69 read_extent_buffer(leaf, buffer, data_ptr,
70 btrfs_dir_data_len(leaf, di));
71 ret = btrfs_dir_data_len(leaf, di);
72
73out:
74 btrfs_free_path(path);
75 return ret;
76}
77
78static int do_setxattr(struct btrfs_trans_handle *trans,
79 struct inode *inode, const char *name,
80 const void *value, size_t size, int flags)
81{
82 struct btrfs_dir_item *di = NULL;
83 struct btrfs_root *root = BTRFS_I(inode)->root;
84 struct btrfs_fs_info *fs_info = root->fs_info;
85 struct btrfs_path *path;
86 size_t name_len = strlen(name);
87 int ret = 0;
88
89 if (name_len + size > BTRFS_MAX_XATTR_SIZE(root->fs_info))
90 return -ENOSPC;
91
92 path = btrfs_alloc_path();
93 if (!path)
94 return -ENOMEM;
95 path->skip_release_on_error = 1;
96
97 if (!value) {
98 di = btrfs_lookup_xattr(trans, root, path,
99 btrfs_ino(BTRFS_I(inode)), name, name_len, -1);
100 if (!di && (flags & XATTR_REPLACE))
101 ret = -ENODATA;
102 else if (IS_ERR(di))
103 ret = PTR_ERR(di);
104 else if (di)
105 ret = btrfs_delete_one_dir_name(trans, root, path, di);
106 goto out;
107 }
108
109 /*
110 * For a replace we can't just do the insert blindly.
111 * Do a lookup first (read-only btrfs_search_slot), and return if xattr
112 * doesn't exist. If it exists, fall down below to the insert/replace
113 * path - we can't race with a concurrent xattr delete, because the VFS
114 * locks the inode's i_mutex before calling setxattr or removexattr.
115 */
116 if (flags & XATTR_REPLACE) {
117 ASSERT(inode_is_locked(inode));
118 di = btrfs_lookup_xattr(NULL, root, path,
119 btrfs_ino(BTRFS_I(inode)), name, name_len, 0);
120 if (!di)
121 ret = -ENODATA;
122 else if (IS_ERR(di))
123 ret = PTR_ERR(di);
124 if (ret)
125 goto out;
126 btrfs_release_path(path);
127 di = NULL;
128 }
129
130 ret = btrfs_insert_xattr_item(trans, root, path, btrfs_ino(BTRFS_I(inode)),
131 name, name_len, value, size);
132 if (ret == -EOVERFLOW) {
133 /*
134 * We have an existing item in a leaf, split_leaf couldn't
135 * expand it. That item might have or not a dir_item that
136 * matches our target xattr, so lets check.
137 */
138 ret = 0;
139 btrfs_assert_tree_locked(path->nodes[0]);
140 di = btrfs_match_dir_item_name(fs_info, path, name, name_len);
141 if (!di && !(flags & XATTR_REPLACE)) {
142 ret = -ENOSPC;
143 goto out;
144 }
145 } else if (ret == -EEXIST) {
146 ret = 0;
147 di = btrfs_match_dir_item_name(fs_info, path, name, name_len);
148 ASSERT(di); /* logic error */
149 } else if (ret) {
150 goto out;
151 }
152
153 if (di && (flags & XATTR_CREATE)) {
154 ret = -EEXIST;
155 goto out;
156 }
157
158 if (di) {
159 /*
160 * We're doing a replace, and it must be atomic, that is, at
161 * any point in time we have either the old or the new xattr
162 * value in the tree. We don't want readers (getxattr and
163 * listxattrs) to miss a value, this is specially important
164 * for ACLs.
165 */
166 const int slot = path->slots[0];
167 struct extent_buffer *leaf = path->nodes[0];
168 const u16 old_data_len = btrfs_dir_data_len(leaf, di);
169 const u32 item_size = btrfs_item_size_nr(leaf, slot);
170 const u32 data_size = sizeof(*di) + name_len + size;
171 struct btrfs_item *item;
172 unsigned long data_ptr;
173 char *ptr;
174
175 if (size > old_data_len) {
176 if (btrfs_leaf_free_space(fs_info, leaf) <
177 (size - old_data_len)) {
178 ret = -ENOSPC;
179 goto out;
180 }
181 }
182
183 if (old_data_len + name_len + sizeof(*di) == item_size) {
184 /* No other xattrs packed in the same leaf item. */
185 if (size > old_data_len)
186 btrfs_extend_item(fs_info, path,
187 size - old_data_len);
188 else if (size < old_data_len)
189 btrfs_truncate_item(fs_info, path,
190 data_size, 1);
191 } else {
192 /* There are other xattrs packed in the same item. */
193 ret = btrfs_delete_one_dir_name(trans, root, path, di);
194 if (ret)
195 goto out;
196 btrfs_extend_item(fs_info, path, data_size);
197 }
198
199 item = btrfs_item_nr(slot);
200 ptr = btrfs_item_ptr(leaf, slot, char);
201 ptr += btrfs_item_size(leaf, item) - data_size;
202 di = (struct btrfs_dir_item *)ptr;
203 btrfs_set_dir_data_len(leaf, di, size);
204 data_ptr = ((unsigned long)(di + 1)) + name_len;
205 write_extent_buffer(leaf, value, data_ptr, size);
206 btrfs_mark_buffer_dirty(leaf);
207 } else {
208 /*
209 * Insert, and we had space for the xattr, so path->slots[0] is
210 * where our xattr dir_item is and btrfs_insert_xattr_item()
211 * filled it.
212 */
213 }
214out:
215 btrfs_free_path(path);
216 return ret;
217}
218
219/*
220 * @value: "" makes the attribute to empty, NULL removes it
221 */
222int btrfs_setxattr(struct btrfs_trans_handle *trans,
223 struct inode *inode, const char *name,
224 const void *value, size_t size, int flags)
225{
226 struct btrfs_root *root = BTRFS_I(inode)->root;
227 int ret;
228
229 if (btrfs_root_readonly(root))
230 return -EROFS;
231
232 if (trans)
233 return do_setxattr(trans, inode, name, value, size, flags);
234
235 trans = btrfs_start_transaction(root, 2);
236 if (IS_ERR(trans))
237 return PTR_ERR(trans);
238
239 ret = do_setxattr(trans, inode, name, value, size, flags);
240 if (ret)
241 goto out;
242
243 inode_inc_iversion(inode);
244 inode->i_ctime = current_time(inode);
245 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
246 ret = btrfs_update_inode(trans, root, inode);
247 BUG_ON(ret);
248out:
249 btrfs_end_transaction(trans);
250 return ret;
251}
252
253ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
254{
255 struct btrfs_key key;
256 struct inode *inode = d_inode(dentry);
257 struct btrfs_root *root = BTRFS_I(inode)->root;
258 struct btrfs_path *path;
259 int ret = 0;
260 size_t total_size = 0, size_left = size;
261
262 /*
263 * ok we want all objects associated with this id.
264 * NOTE: we set key.offset = 0; because we want to start with the
265 * first xattr that we find and walk forward
266 */
267 key.objectid = btrfs_ino(BTRFS_I(inode));
268 key.type = BTRFS_XATTR_ITEM_KEY;
269 key.offset = 0;
270
271 path = btrfs_alloc_path();
272 if (!path)
273 return -ENOMEM;
274 path->reada = READA_FORWARD;
275
276 /* search for our xattrs */
277 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
278 if (ret < 0)
279 goto err;
280
281 while (1) {
282 struct extent_buffer *leaf;
283 int slot;
284 struct btrfs_dir_item *di;
285 struct btrfs_key found_key;
286 u32 item_size;
287 u32 cur;
288
289 leaf = path->nodes[0];
290 slot = path->slots[0];
291
292 /* this is where we start walking through the path */
293 if (slot >= btrfs_header_nritems(leaf)) {
294 /*
295 * if we've reached the last slot in this leaf we need
296 * to go to the next leaf and reset everything
297 */
298 ret = btrfs_next_leaf(root, path);
299 if (ret < 0)
300 goto err;
301 else if (ret > 0)
302 break;
303 continue;
304 }
305
306 btrfs_item_key_to_cpu(leaf, &found_key, slot);
307
308 /* check to make sure this item is what we want */
309 if (found_key.objectid != key.objectid)
310 break;
311 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
312 break;
313 if (found_key.type < BTRFS_XATTR_ITEM_KEY)
314 goto next_item;
315
316 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
317 item_size = btrfs_item_size_nr(leaf, slot);
318 cur = 0;
319 while (cur < item_size) {
320 u16 name_len = btrfs_dir_name_len(leaf, di);
321 u16 data_len = btrfs_dir_data_len(leaf, di);
322 u32 this_len = sizeof(*di) + name_len + data_len;
323 unsigned long name_ptr = (unsigned long)(di + 1);
324
325 total_size += name_len + 1;
326 /*
327 * We are just looking for how big our buffer needs to
328 * be.
329 */
330 if (!size)
331 goto next;
332
333 if (!buffer || (name_len + 1) > size_left) {
334 ret = -ERANGE;
335 goto err;
336 }
337
338 read_extent_buffer(leaf, buffer, name_ptr, name_len);
339 buffer[name_len] = '\0';
340
341 size_left -= name_len + 1;
342 buffer += name_len + 1;
343next:
344 cur += this_len;
345 di = (struct btrfs_dir_item *)((char *)di + this_len);
346 }
347next_item:
348 path->slots[0]++;
349 }
350 ret = total_size;
351
352err:
353 btrfs_free_path(path);
354
355 return ret;
356}
357
358static int btrfs_xattr_handler_get(const struct xattr_handler *handler,
359 struct dentry *unused, struct inode *inode,
360 const char *name, void *buffer, size_t size)
361{
362 name = xattr_full_name(handler, name);
363 return btrfs_getxattr(inode, name, buffer, size);
364}
365
366static int btrfs_xattr_handler_set(const struct xattr_handler *handler,
367 struct dentry *unused, struct inode *inode,
368 const char *name, const void *buffer,
369 size_t size, int flags)
370{
371 name = xattr_full_name(handler, name);
372 return btrfs_setxattr(NULL, inode, name, buffer, size, flags);
373}
374
375static int btrfs_xattr_handler_set_prop(const struct xattr_handler *handler,
376 struct dentry *unused, struct inode *inode,
377 const char *name, const void *value,
378 size_t size, int flags)
379{
380 name = xattr_full_name(handler, name);
381 return btrfs_set_prop(inode, name, value, size, flags);
382}
383
384static const struct xattr_handler btrfs_security_xattr_handler = {
385 .prefix = XATTR_SECURITY_PREFIX,
386 .get = btrfs_xattr_handler_get,
387 .set = btrfs_xattr_handler_set,
388};
389
390static const struct xattr_handler btrfs_trusted_xattr_handler = {
391 .prefix = XATTR_TRUSTED_PREFIX,
392 .get = btrfs_xattr_handler_get,
393 .set = btrfs_xattr_handler_set,
394};
395
396static const struct xattr_handler btrfs_user_xattr_handler = {
397 .prefix = XATTR_USER_PREFIX,
398 .get = btrfs_xattr_handler_get,
399 .set = btrfs_xattr_handler_set,
400};
401
402static const struct xattr_handler btrfs_btrfs_xattr_handler = {
403 .prefix = XATTR_BTRFS_PREFIX,
404 .get = btrfs_xattr_handler_get,
405 .set = btrfs_xattr_handler_set_prop,
406};
407
408const struct xattr_handler *btrfs_xattr_handlers[] = {
409 &btrfs_security_xattr_handler,
410#ifdef CONFIG_BTRFS_FS_POSIX_ACL
411 &posix_acl_access_xattr_handler,
412 &posix_acl_default_xattr_handler,
413#endif
414 &btrfs_trusted_xattr_handler,
415 &btrfs_user_xattr_handler,
416 &btrfs_btrfs_xattr_handler,
417 NULL,
418};
419
420static int btrfs_initxattrs(struct inode *inode,
421 const struct xattr *xattr_array, void *fs_info)
422{
423 const struct xattr *xattr;
424 struct btrfs_trans_handle *trans = fs_info;
425 char *name;
426 int err = 0;
427
428 for (xattr = xattr_array; xattr->name != NULL; xattr++) {
429 name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
430 strlen(xattr->name) + 1, GFP_KERNEL);
431 if (!name) {
432 err = -ENOMEM;
433 break;
434 }
435 strcpy(name, XATTR_SECURITY_PREFIX);
436 strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
437 err = btrfs_setxattr(trans, inode, name, xattr->value,
438 xattr->value_len, 0);
439 kfree(name);
440 if (err < 0)
441 break;
442 }
443 return err;
444}
445
446int btrfs_xattr_security_init(struct btrfs_trans_handle *trans,
447 struct inode *inode, struct inode *dir,
448 const struct qstr *qstr)
449{
450 return security_inode_init_security(inode, dir, qstr,
451 &btrfs_initxattrs, trans);
452}
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_fs_info *fs_info = root->fs_info;
98 struct btrfs_path *path;
99 size_t name_len = strlen(name);
100 int ret = 0;
101
102 if (name_len + size > BTRFS_MAX_XATTR_SIZE(root->fs_info))
103 return -ENOSPC;
104
105 path = btrfs_alloc_path();
106 if (!path)
107 return -ENOMEM;
108 path->skip_release_on_error = 1;
109
110 if (!value) {
111 di = btrfs_lookup_xattr(trans, root, path, btrfs_ino(inode),
112 name, name_len, -1);
113 if (!di && (flags & XATTR_REPLACE))
114 ret = -ENODATA;
115 else if (IS_ERR(di))
116 ret = PTR_ERR(di);
117 else if (di)
118 ret = btrfs_delete_one_dir_name(trans, root, path, di);
119 goto out;
120 }
121
122 /*
123 * For a replace we can't just do the insert blindly.
124 * Do a lookup first (read-only btrfs_search_slot), and return if xattr
125 * doesn't exist. If it exists, fall down below to the insert/replace
126 * path - we can't race with a concurrent xattr delete, because the VFS
127 * locks the inode's i_mutex before calling setxattr or removexattr.
128 */
129 if (flags & XATTR_REPLACE) {
130 ASSERT(inode_is_locked(inode));
131 di = btrfs_lookup_xattr(NULL, root, path, btrfs_ino(inode),
132 name, name_len, 0);
133 if (!di)
134 ret = -ENODATA;
135 else if (IS_ERR(di))
136 ret = PTR_ERR(di);
137 if (ret)
138 goto out;
139 btrfs_release_path(path);
140 di = NULL;
141 }
142
143 ret = btrfs_insert_xattr_item(trans, root, path, btrfs_ino(inode),
144 name, name_len, value, size);
145 if (ret == -EOVERFLOW) {
146 /*
147 * We have an existing item in a leaf, split_leaf couldn't
148 * expand it. That item might have or not a dir_item that
149 * matches our target xattr, so lets check.
150 */
151 ret = 0;
152 btrfs_assert_tree_locked(path->nodes[0]);
153 di = btrfs_match_dir_item_name(fs_info, path, name, name_len);
154 if (!di && !(flags & XATTR_REPLACE)) {
155 ret = -ENOSPC;
156 goto out;
157 }
158 } else if (ret == -EEXIST) {
159 ret = 0;
160 di = btrfs_match_dir_item_name(fs_info, path, name, name_len);
161 ASSERT(di); /* logic error */
162 } else if (ret) {
163 goto out;
164 }
165
166 if (di && (flags & XATTR_CREATE)) {
167 ret = -EEXIST;
168 goto out;
169 }
170
171 if (di) {
172 /*
173 * We're doing a replace, and it must be atomic, that is, at
174 * any point in time we have either the old or the new xattr
175 * value in the tree. We don't want readers (getxattr and
176 * listxattrs) to miss a value, this is specially important
177 * for ACLs.
178 */
179 const int slot = path->slots[0];
180 struct extent_buffer *leaf = path->nodes[0];
181 const u16 old_data_len = btrfs_dir_data_len(leaf, di);
182 const u32 item_size = btrfs_item_size_nr(leaf, slot);
183 const u32 data_size = sizeof(*di) + name_len + size;
184 struct btrfs_item *item;
185 unsigned long data_ptr;
186 char *ptr;
187
188 if (size > old_data_len) {
189 if (btrfs_leaf_free_space(fs_info, leaf) <
190 (size - old_data_len)) {
191 ret = -ENOSPC;
192 goto out;
193 }
194 }
195
196 if (old_data_len + name_len + sizeof(*di) == item_size) {
197 /* No other xattrs packed in the same leaf item. */
198 if (size > old_data_len)
199 btrfs_extend_item(fs_info, path,
200 size - old_data_len);
201 else if (size < old_data_len)
202 btrfs_truncate_item(fs_info, path,
203 data_size, 1);
204 } else {
205 /* There are other xattrs packed in the same item. */
206 ret = btrfs_delete_one_dir_name(trans, root, path, di);
207 if (ret)
208 goto out;
209 btrfs_extend_item(fs_info, path, data_size);
210 }
211
212 item = btrfs_item_nr(slot);
213 ptr = btrfs_item_ptr(leaf, slot, char);
214 ptr += btrfs_item_size(leaf, item) - data_size;
215 di = (struct btrfs_dir_item *)ptr;
216 btrfs_set_dir_data_len(leaf, di, size);
217 data_ptr = ((unsigned long)(di + 1)) + name_len;
218 write_extent_buffer(leaf, value, data_ptr, size);
219 btrfs_mark_buffer_dirty(leaf);
220 } else {
221 /*
222 * Insert, and we had space for the xattr, so path->slots[0] is
223 * where our xattr dir_item is and btrfs_insert_xattr_item()
224 * filled it.
225 */
226 }
227out:
228 btrfs_free_path(path);
229 return ret;
230}
231
232/*
233 * @value: "" makes the attribute to empty, NULL removes it
234 */
235int __btrfs_setxattr(struct btrfs_trans_handle *trans,
236 struct inode *inode, const char *name,
237 const void *value, size_t size, int flags)
238{
239 struct btrfs_root *root = BTRFS_I(inode)->root;
240 int ret;
241
242 if (btrfs_root_readonly(root))
243 return -EROFS;
244
245 if (trans)
246 return do_setxattr(trans, inode, name, value, size, flags);
247
248 trans = btrfs_start_transaction(root, 2);
249 if (IS_ERR(trans))
250 return PTR_ERR(trans);
251
252 ret = do_setxattr(trans, inode, name, value, size, flags);
253 if (ret)
254 goto out;
255
256 inode_inc_iversion(inode);
257 inode->i_ctime = current_time(inode);
258 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
259 ret = btrfs_update_inode(trans, root, inode);
260 BUG_ON(ret);
261out:
262 btrfs_end_transaction(trans);
263 return ret;
264}
265
266ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
267{
268 struct btrfs_key key;
269 struct inode *inode = d_inode(dentry);
270 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
271 struct btrfs_root *root = BTRFS_I(inode)->root;
272 struct btrfs_path *path;
273 int ret = 0;
274 size_t total_size = 0, size_left = size;
275
276 /*
277 * ok we want all objects associated with this id.
278 * NOTE: we set key.offset = 0; because we want to start with the
279 * first xattr that we find and walk forward
280 */
281 key.objectid = btrfs_ino(inode);
282 key.type = BTRFS_XATTR_ITEM_KEY;
283 key.offset = 0;
284
285 path = btrfs_alloc_path();
286 if (!path)
287 return -ENOMEM;
288 path->reada = READA_FORWARD;
289
290 /* search for our xattrs */
291 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
292 if (ret < 0)
293 goto err;
294
295 while (1) {
296 struct extent_buffer *leaf;
297 int slot;
298 struct btrfs_dir_item *di;
299 struct btrfs_key found_key;
300 u32 item_size;
301 u32 cur;
302
303 leaf = path->nodes[0];
304 slot = path->slots[0];
305
306 /* this is where we start walking through the path */
307 if (slot >= btrfs_header_nritems(leaf)) {
308 /*
309 * if we've reached the last slot in this leaf we need
310 * to go to the next leaf and reset everything
311 */
312 ret = btrfs_next_leaf(root, path);
313 if (ret < 0)
314 goto err;
315 else if (ret > 0)
316 break;
317 continue;
318 }
319
320 btrfs_item_key_to_cpu(leaf, &found_key, slot);
321
322 /* check to make sure this item is what we want */
323 if (found_key.objectid != key.objectid)
324 break;
325 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
326 break;
327 if (found_key.type < BTRFS_XATTR_ITEM_KEY)
328 goto next_item;
329
330 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
331 item_size = btrfs_item_size_nr(leaf, slot);
332 cur = 0;
333 while (cur < item_size) {
334 u16 name_len = btrfs_dir_name_len(leaf, di);
335 u16 data_len = btrfs_dir_data_len(leaf, di);
336 u32 this_len = sizeof(*di) + name_len + data_len;
337 unsigned long name_ptr = (unsigned long)(di + 1);
338
339 if (verify_dir_item(fs_info, leaf, di)) {
340 ret = -EIO;
341 goto err;
342 }
343
344 total_size += name_len + 1;
345 /*
346 * We are just looking for how big our buffer needs to
347 * be.
348 */
349 if (!size)
350 goto next;
351
352 if (!buffer || (name_len + 1) > size_left) {
353 ret = -ERANGE;
354 goto err;
355 }
356
357 read_extent_buffer(leaf, buffer, name_ptr, name_len);
358 buffer[name_len] = '\0';
359
360 size_left -= name_len + 1;
361 buffer += name_len + 1;
362next:
363 cur += this_len;
364 di = (struct btrfs_dir_item *)((char *)di + this_len);
365 }
366next_item:
367 path->slots[0]++;
368 }
369 ret = total_size;
370
371err:
372 btrfs_free_path(path);
373
374 return ret;
375}
376
377static int btrfs_xattr_handler_get(const struct xattr_handler *handler,
378 struct dentry *unused, struct inode *inode,
379 const char *name, void *buffer, size_t size)
380{
381 name = xattr_full_name(handler, name);
382 return __btrfs_getxattr(inode, name, buffer, size);
383}
384
385static int btrfs_xattr_handler_set(const struct xattr_handler *handler,
386 struct dentry *unused, struct inode *inode,
387 const char *name, const void *buffer,
388 size_t size, int flags)
389{
390 name = xattr_full_name(handler, name);
391 return __btrfs_setxattr(NULL, inode, name, buffer, size, flags);
392}
393
394static int btrfs_xattr_handler_set_prop(const struct xattr_handler *handler,
395 struct dentry *unused, struct inode *inode,
396 const char *name, const void *value,
397 size_t size, int flags)
398{
399 name = xattr_full_name(handler, name);
400 return btrfs_set_prop(inode, name, value, size, flags);
401}
402
403static const struct xattr_handler btrfs_security_xattr_handler = {
404 .prefix = XATTR_SECURITY_PREFIX,
405 .get = btrfs_xattr_handler_get,
406 .set = btrfs_xattr_handler_set,
407};
408
409static const struct xattr_handler btrfs_trusted_xattr_handler = {
410 .prefix = XATTR_TRUSTED_PREFIX,
411 .get = btrfs_xattr_handler_get,
412 .set = btrfs_xattr_handler_set,
413};
414
415static const struct xattr_handler btrfs_user_xattr_handler = {
416 .prefix = XATTR_USER_PREFIX,
417 .get = btrfs_xattr_handler_get,
418 .set = btrfs_xattr_handler_set,
419};
420
421static const struct xattr_handler btrfs_btrfs_xattr_handler = {
422 .prefix = XATTR_BTRFS_PREFIX,
423 .get = btrfs_xattr_handler_get,
424 .set = btrfs_xattr_handler_set_prop,
425};
426
427const struct xattr_handler *btrfs_xattr_handlers[] = {
428 &btrfs_security_xattr_handler,
429#ifdef CONFIG_BTRFS_FS_POSIX_ACL
430 &posix_acl_access_xattr_handler,
431 &posix_acl_default_xattr_handler,
432#endif
433 &btrfs_trusted_xattr_handler,
434 &btrfs_user_xattr_handler,
435 &btrfs_btrfs_xattr_handler,
436 NULL,
437};
438
439static int btrfs_initxattrs(struct inode *inode,
440 const struct xattr *xattr_array, void *fs_info)
441{
442 const struct xattr *xattr;
443 struct btrfs_trans_handle *trans = fs_info;
444 char *name;
445 int err = 0;
446
447 for (xattr = xattr_array; xattr->name != NULL; xattr++) {
448 name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
449 strlen(xattr->name) + 1, GFP_KERNEL);
450 if (!name) {
451 err = -ENOMEM;
452 break;
453 }
454 strcpy(name, XATTR_SECURITY_PREFIX);
455 strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
456 err = __btrfs_setxattr(trans, inode, name,
457 xattr->value, xattr->value_len, 0);
458 kfree(name);
459 if (err < 0)
460 break;
461 }
462 return err;
463}
464
465int btrfs_xattr_security_init(struct btrfs_trans_handle *trans,
466 struct inode *inode, struct inode *dir,
467 const struct qstr *qstr)
468{
469 return security_inode_init_security(inode, dir, qstr,
470 &btrfs_initxattrs, trans);
471}