2 * Copyright (C) 2007 Red Hat. All rights reserved.
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.
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.
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.
19 #include <linux/init.h>
21 #include <linux/slab.h>
22 #include <linux/rwsem.h>
23 #include <linux/xattr.h>
25 #include "btrfs_inode.h"
26 #include "transaction.h"
29 static struct xattr_handler *btrfs_xattr_handler_map[] = {
30 [BTRFS_XATTR_INDEX_USER] = &btrfs_xattr_user_handler,
31 #ifdef CONFIG_FS_POSIX_ACL
32 // [BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS] = &btrfs_xattr_acl_access_handler,
33 // [BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT] = &btrfs_xattr_acl_default_handler,
35 [BTRFS_XATTR_INDEX_TRUSTED] = &btrfs_xattr_trusted_handler,
36 [BTRFS_XATTR_INDEX_SECURITY] = &btrfs_xattr_security_handler,
37 // [BTRFS_XATTR_INDEX_SYSTEM] = &btrfs_xattr_system_handler,
39 struct xattr_handler *btrfs_xattr_handlers[] = {
40 &btrfs_xattr_user_handler,
41 #ifdef CONFIG_FS_POSIX_ACL
42 // &btrfs_xattr_acl_access_handler,
43 // &btrfs_xattr_acl_default_handler,
45 &btrfs_xattr_trusted_handler,
46 &btrfs_xattr_security_handler,
47 // &btrfs_xattr_system_handler,
52 * @param name - the xattr name
53 * @return - the xattr_handler for the xattr, NULL if its not found
55 * use this with listxattr where we don't already know the type of xattr we
58 static struct xattr_handler *find_btrfs_xattr_handler(struct extent_buffer *l,
59 unsigned long name_ptr,
62 struct xattr_handler *handler = NULL;
65 for (handler = btrfs_xattr_handlers[i]; handler != NULL; i++,
66 handler = btrfs_xattr_handlers[i]) {
67 u16 prefix_len = strlen(handler->prefix);
69 if (name_len < prefix_len)
72 if (memcmp_extent_buffer(l, handler->prefix, name_ptr,
81 * @param name_index - the index for the xattr handler
82 * @return the xattr_handler if we found it, NULL otherwise
84 * use this if we know the type of the xattr already
86 static struct xattr_handler *btrfs_xattr_handler(int name_index)
88 struct xattr_handler *handler = NULL;
90 if (name_index >= 0 &&
91 name_index < ARRAY_SIZE(btrfs_xattr_handler_map))
92 handler = btrfs_xattr_handler_map[name_index];
97 static inline char *get_name(const char *name, int name_index)
100 struct xattr_handler *handler = btrfs_xattr_handler(name_index);
106 prefix_len = strlen(handler->prefix);
108 ret = kmalloc(strlen(name) + prefix_len + 1, GFP_KERNEL);
112 memcpy(ret, handler->prefix, prefix_len);
113 memcpy(ret+prefix_len, name, strlen(name));
114 ret[prefix_len + strlen(name)] = '\0';
119 size_t btrfs_xattr_generic_list(struct inode *inode, char *list,
120 size_t list_size, const char *name,
123 if (list && (name_len+1) <= list_size) {
124 memcpy(list, name, name_len);
125 list[name_len] = '\0';
132 ssize_t btrfs_xattr_get(struct inode *inode, int name_index,
133 const char *attr_name, void *buffer, size_t size)
135 struct btrfs_dir_item *di;
136 struct btrfs_root *root = BTRFS_I(inode)->root;
137 struct btrfs_path *path;
138 struct extent_buffer *leaf;
139 struct xattr_handler *handler = btrfs_xattr_handler(name_index);
141 unsigned long data_ptr;
146 name = get_name(attr_name, name_index);
150 path = btrfs_alloc_path();
156 /* lookup the xattr by name */
157 di = btrfs_lookup_xattr(NULL, root, path, inode->i_ino, name,
159 if (!di || IS_ERR(di)) {
164 leaf = path->nodes[0];
165 /* if size is 0, that means we want the size of the attr */
167 ret = btrfs_dir_data_len(leaf, di);
171 /* now get the data out of our dir_item */
172 if (btrfs_dir_data_len(leaf, di) > size) {
176 data_ptr = (unsigned long)((char *)(di + 1) +
177 btrfs_dir_name_len(leaf, di));
178 read_extent_buffer(leaf, buffer, data_ptr,
179 btrfs_dir_data_len(leaf, di));
180 ret = btrfs_dir_data_len(leaf, di);
184 btrfs_free_path(path);
188 int btrfs_xattr_set(struct inode *inode, int name_index,
189 const char *attr_name, const void *value, size_t size,
192 struct btrfs_dir_item *di;
193 struct btrfs_root *root = BTRFS_I(inode)->root;
194 struct btrfs_trans_handle *trans;
195 struct btrfs_path *path;
196 struct xattr_handler *handler = btrfs_xattr_handler(name_index);
198 int ret = 0, mod = 0;
201 name = get_name(attr_name, name_index);
205 path = btrfs_alloc_path();
211 trans = btrfs_start_transaction(root, 1);
212 btrfs_set_trans_block_group(trans, inode);
214 /* first lets see if we already have this xattr */
215 di = btrfs_lookup_xattr(trans, root, path, inode->i_ino, name,
222 /* ok we already have this xattr, lets remove it */
224 /* if we want create only exit */
225 if (flags & XATTR_CREATE) {
230 ret = btrfs_delete_one_dir_name(trans, root, path, di);
233 btrfs_release_path(root, path);
235 /* if we don't have a value then we are removing the xattr */
240 } else if (flags & XATTR_REPLACE) {
241 /* we couldn't find the attr to replace, so error out */
246 /* ok we have to create a completely new xattr */
247 ret = btrfs_insert_xattr_item(trans, root, name, strlen(name),
248 value, size, inode->i_ino);
255 inode->i_ctime = CURRENT_TIME;
256 ret = btrfs_update_inode(trans, root, inode);
259 btrfs_end_transaction(trans, root);
261 btrfs_free_path(path);
266 ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
268 struct btrfs_key key, found_key;
269 struct inode *inode = dentry->d_inode;
270 struct btrfs_root *root = BTRFS_I(inode)->root;
271 struct btrfs_path *path;
272 struct btrfs_item *item;
273 struct extent_buffer *leaf;
274 struct btrfs_dir_item *di;
275 struct xattr_handler *handler;
276 int ret = 0, slot, advance;
277 size_t total_size = 0, size_left = size, written;
278 unsigned long name_ptr;
283 * ok we want all objects associated with this id.
284 * NOTE: we set key.offset = 0; because we want to start with the
285 * first xattr that we find and walk forward
287 key.objectid = inode->i_ino;
288 btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
291 path = btrfs_alloc_path();
296 /* search for our xattrs */
297 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
303 leaf = path->nodes[0];
304 nritems = btrfs_header_nritems(leaf);
305 slot = path->slots[0];
307 /* this is where we start walking through the path */
308 if (advance || slot >= nritems) {
310 * if we've reached the last slot in this leaf we need
311 * to go to the next leaf and reset everything
313 if (slot >= nritems-1) {
314 ret = btrfs_next_leaf(root, path);
317 leaf = path->nodes[0];
318 nritems = btrfs_header_nritems(leaf);
319 slot = path->slots[0];
322 * just walking through the slots on this leaf
330 item = btrfs_item_nr(leaf, slot);
331 btrfs_item_key_to_cpu(leaf, &found_key, slot);
333 /* check to make sure this item is what we want */
334 if (found_key.objectid != key.objectid)
336 if (btrfs_key_type(&found_key) != BTRFS_XATTR_ITEM_KEY)
339 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
341 total_size += btrfs_dir_name_len(leaf, di)+1;
343 /* we are just looking for how big our buffer needs to be */
347 /* find our handler for this xattr */
348 name_ptr = (unsigned long)(di + 1);
349 handler = find_btrfs_xattr_handler(leaf, name_ptr,
350 btrfs_dir_name_len(leaf, di));
352 printk(KERN_ERR "btrfs: unsupported xattr found\n");
356 name = kmalloc(btrfs_dir_name_len(leaf, di), GFP_KERNEL);
357 read_extent_buffer(leaf, name, name_ptr,
358 btrfs_dir_name_len(leaf, di));
360 /* call the list function associated with this xattr */
361 written = handler->list(inode, buffer, size_left, name,
362 btrfs_dir_name_len(leaf, di));
370 size_left -= written;
376 btrfs_free_path(path);
382 * delete all the xattrs associated with the inode.
384 int btrfs_delete_xattrs(struct btrfs_trans_handle *trans,
385 struct btrfs_root *root, struct inode *inode)
387 struct btrfs_path *path;
388 struct btrfs_key key, found_key;
389 struct btrfs_item *item;
390 struct extent_buffer *leaf;
393 path = btrfs_alloc_path();
397 key.objectid = inode->i_ino;
398 btrfs_set_key_type(&key, BTRFS_XATTR_ITEM_KEY);
399 key.offset = (u64)-1;
402 /* look for our next xattr */
403 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
408 if (path->slots[0] == 0)
412 leaf = path->nodes[0];
413 item = btrfs_item_nr(leaf, path->slots[0]);
414 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
416 if (found_key.objectid != key.objectid)
418 if (btrfs_key_type(&found_key) != BTRFS_XATTR_ITEM_KEY)
421 ret = btrfs_del_item(trans, root, path);
423 btrfs_release_path(root, path);
427 btrfs_free_path(path);
435 #define BTRFS_XATTR_SETGET_FUNCS(name, index) \
436 static int btrfs_xattr_##name##_get(struct inode *inode, \
437 const char *name, void *value, \
442 return btrfs_xattr_get(inode, index, name, value, size); \
444 static int btrfs_xattr_##name##_set(struct inode *inode, \
445 const char *name, const void *value,\
446 size_t size, int flags) \
450 return btrfs_xattr_set(inode, index, name, value, size, flags); \
453 BTRFS_XATTR_SETGET_FUNCS(security, BTRFS_XATTR_INDEX_SECURITY);
454 BTRFS_XATTR_SETGET_FUNCS(system, BTRFS_XATTR_INDEX_SYSTEM);
455 BTRFS_XATTR_SETGET_FUNCS(user, BTRFS_XATTR_INDEX_USER);
456 BTRFS_XATTR_SETGET_FUNCS(trusted, BTRFS_XATTR_INDEX_TRUSTED);
458 struct xattr_handler btrfs_xattr_security_handler = {
459 .prefix = XATTR_SECURITY_PREFIX,
460 .list = btrfs_xattr_generic_list,
461 .get = btrfs_xattr_security_get,
462 .set = btrfs_xattr_security_set,
465 struct xattr_handler btrfs_xattr_system_handler = {
466 .prefix = XATTR_SYSTEM_PREFIX,
467 .list = btrfs_xattr_generic_list,
468 .get = btrfs_xattr_system_get,
469 .set = btrfs_xattr_system_set,
472 struct xattr_handler btrfs_xattr_user_handler = {
473 .prefix = XATTR_USER_PREFIX,
474 .list = btrfs_xattr_generic_list,
475 .get = btrfs_xattr_user_get,
476 .set = btrfs_xattr_user_set,
479 struct xattr_handler btrfs_xattr_trusted_handler = {
480 .prefix = XATTR_TRUSTED_PREFIX,
481 .list = btrfs_xattr_generic_list,
482 .get = btrfs_xattr_trusted_get,
483 .set = btrfs_xattr_trusted_set,