xref: /openbmc/linux/fs/ext4/xattr_user.c (revision 588b48ca)
1 /*
2  * linux/fs/ext4/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/string.h>
9 #include <linux/fs.h>
10 #include "ext4_jbd2.h"
11 #include "ext4.h"
12 #include "xattr.h"
13 
14 static size_t
15 ext4_xattr_user_list(struct dentry *dentry, char *list, size_t list_size,
16 		     const char *name, size_t name_len, int type)
17 {
18 	const size_t prefix_len = XATTR_USER_PREFIX_LEN;
19 	const size_t total_len = prefix_len + name_len + 1;
20 
21 	if (!test_opt(dentry->d_sb, XATTR_USER))
22 		return 0;
23 
24 	if (list && total_len <= list_size) {
25 		memcpy(list, XATTR_USER_PREFIX, prefix_len);
26 		memcpy(list+prefix_len, name, name_len);
27 		list[prefix_len + name_len] = '\0';
28 	}
29 	return total_len;
30 }
31 
32 static int
33 ext4_xattr_user_get(struct dentry *dentry, const char *name,
34 		    void *buffer, size_t size, int type)
35 {
36 	if (strcmp(name, "") == 0)
37 		return -EINVAL;
38 	if (!test_opt(dentry->d_sb, XATTR_USER))
39 		return -EOPNOTSUPP;
40 	return ext4_xattr_get(dentry->d_inode, EXT4_XATTR_INDEX_USER,
41 			      name, buffer, size);
42 }
43 
44 static int
45 ext4_xattr_user_set(struct dentry *dentry, const char *name,
46 		    const void *value, size_t size, int flags, int type)
47 {
48 	if (strcmp(name, "") == 0)
49 		return -EINVAL;
50 	if (!test_opt(dentry->d_sb, XATTR_USER))
51 		return -EOPNOTSUPP;
52 	return ext4_xattr_set(dentry->d_inode, EXT4_XATTR_INDEX_USER,
53 			      name, value, size, flags);
54 }
55 
56 const struct xattr_handler ext4_xattr_user_handler = {
57 	.prefix	= XATTR_USER_PREFIX,
58 	.list	= ext4_xattr_user_list,
59 	.get	= ext4_xattr_user_get,
60 	.set	= ext4_xattr_user_set,
61 };
62