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/module.h>
9#include <linux/string.h>
10#include <linux/fs.h>
11#include <linux/ext4_jbd2.h>
12#include <linux/ext4_fs.h>
13#include "xattr.h"
14
15#define XATTR_USER_PREFIX "user."
16
17static size_t
18ext4_xattr_user_list(struct inode *inode, char *list, size_t list_size,
19		     const char *name, size_t name_len)
20{
21	const size_t prefix_len = sizeof(XATTR_USER_PREFIX)-1;
22	const size_t total_len = prefix_len + name_len + 1;
23
24	if (!test_opt(inode->i_sb, XATTR_USER))
25		return 0;
26
27	if (list && total_len <= list_size) {
28		memcpy(list, XATTR_USER_PREFIX, prefix_len);
29		memcpy(list+prefix_len, name, name_len);
30		list[prefix_len + name_len] = '\0';
31	}
32	return total_len;
33}
34
35static int
36ext4_xattr_user_get(struct inode *inode, const char *name,
37		    void *buffer, size_t size)
38{
39	if (strcmp(name, "") == 0)
40		return -EINVAL;
41	if (!test_opt(inode->i_sb, XATTR_USER))
42		return -EOPNOTSUPP;
43	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_USER, name, buffer, size);
44}
45
46static int
47ext4_xattr_user_set(struct inode *inode, const char *name,
48		    const void *value, size_t size, int flags)
49{
50	if (strcmp(name, "") == 0)
51		return -EINVAL;
52	if (!test_opt(inode->i_sb, XATTR_USER))
53		return -EOPNOTSUPP;
54	return ext4_xattr_set(inode, EXT4_XATTR_INDEX_USER, name,
55			      value, size, flags);
56}
57
58struct xattr_handler ext4_xattr_user_handler = {
59	.prefix	= XATTR_USER_PREFIX,
60	.list	= ext4_xattr_user_list,
61	.get	= ext4_xattr_user_get,
62	.set	= ext4_xattr_user_set,
63};
64