xref: /linux/fs/ext2/xattr_user.c (revision 861e10be08c69808065d755d3e3cab5d520a2d32)
1 /*
2  * linux/fs/ext2/xattr_user.c
3  * Handler for extended user attributes.
4  *
5  * Copyright (C) 2001 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
6  */
7 
8 #include <linux/init.h>
9 #include <linux/string.h>
10 #include "ext2.h"
11 #include "xattr.h"
12 
13 static size_t
14 ext2_xattr_user_list(struct dentry *dentry, char *list, size_t list_size,
15 		const char *name, size_t name_len, int type)
16 {
17 	const size_t prefix_len = XATTR_USER_PREFIX_LEN;
18 	const size_t total_len = prefix_len + name_len + 1;
19 
20 	if (!test_opt(dentry->d_sb, XATTR_USER))
21 		return 0;
22 
23 	if (list && total_len <= list_size) {
24 		memcpy(list, XATTR_USER_PREFIX, prefix_len);
25 		memcpy(list+prefix_len, name, name_len);
26 		list[prefix_len + name_len] = '\0';
27 	}
28 	return total_len;
29 }
30 
31 static int
32 ext2_xattr_user_get(struct dentry *dentry, const char *name,
33 		void *buffer, size_t size, int type)
34 {
35 	if (strcmp(name, "") == 0)
36 		return -EINVAL;
37 	if (!test_opt(dentry->d_sb, XATTR_USER))
38 		return -EOPNOTSUPP;
39 	return ext2_xattr_get(dentry->d_inode, EXT2_XATTR_INDEX_USER,
40 			      name, buffer, size);
41 }
42 
43 static int
44 ext2_xattr_user_set(struct dentry *dentry, const char *name,
45 		const void *value, size_t size, int flags, int type)
46 {
47 	if (strcmp(name, "") == 0)
48 		return -EINVAL;
49 	if (!test_opt(dentry->d_sb, XATTR_USER))
50 		return -EOPNOTSUPP;
51 
52 	return ext2_xattr_set(dentry->d_inode, EXT2_XATTR_INDEX_USER,
53 			      name, value, size, flags);
54 }
55 
56 const struct xattr_handler ext2_xattr_user_handler = {
57 	.prefix	= XATTR_USER_PREFIX,
58 	.list	= ext2_xattr_user_list,
59 	.get	= ext2_xattr_user_get,
60 	.set	= ext2_xattr_user_set,
61 };
62