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
);
384 #define BTRFS_XATTR_SETGET_FUNCS(name, index) \
385 static int btrfs_xattr_##name##_get(struct inode *inode, \
386 const char *name, void *value, \
391 return btrfs_xattr_get(inode, index, name, value, size); \
393 static int btrfs_xattr_##name##_set(struct inode *inode, \
394 const char *name, const void *value,\
395 size_t size, int flags) \
399 return btrfs_xattr_set(inode, index, name, value, size, flags); \
402 BTRFS_XATTR_SETGET_FUNCS(security
, BTRFS_XATTR_INDEX_SECURITY
);
403 BTRFS_XATTR_SETGET_FUNCS(system
, BTRFS_XATTR_INDEX_SYSTEM
);
404 BTRFS_XATTR_SETGET_FUNCS(user
, BTRFS_XATTR_INDEX_USER
);
405 BTRFS_XATTR_SETGET_FUNCS(trusted
, BTRFS_XATTR_INDEX_TRUSTED
);
407 struct xattr_handler btrfs_xattr_security_handler
= {
408 .prefix
= XATTR_SECURITY_PREFIX
,
409 .list
= btrfs_xattr_generic_list
,
410 .get
= btrfs_xattr_security_get
,
411 .set
= btrfs_xattr_security_set
,
414 struct xattr_handler btrfs_xattr_system_handler
= {
415 .prefix
= XATTR_SYSTEM_PREFIX
,
416 .list
= btrfs_xattr_generic_list
,
417 .get
= btrfs_xattr_system_get
,
418 .set
= btrfs_xattr_system_set
,
421 struct xattr_handler btrfs_xattr_user_handler
= {
422 .prefix
= XATTR_USER_PREFIX
,
423 .list
= btrfs_xattr_generic_list
,
424 .get
= btrfs_xattr_user_get
,
425 .set
= btrfs_xattr_user_set
,
428 struct xattr_handler btrfs_xattr_trusted_handler
= {
429 .prefix
= XATTR_TRUSTED_PREFIX
,
430 .list
= btrfs_xattr_generic_list
,
431 .get
= btrfs_xattr_trusted_get
,
432 .set
= btrfs_xattr_trusted_set
,