tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * linux/fs/ext3/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/smp_lock.h>
12#include <linux/ext3_jbd.h>
13#include <linux/ext3_fs.h>
14#include "xattr.h"
15
16#define XATTR_USER_PREFIX "user."
17
18static size_t
19ext3_xattr_user_list(struct inode *inode, char *list, size_t list_size,
20 const char *name, size_t name_len)
21{
22 const size_t prefix_len = sizeof(XATTR_USER_PREFIX)-1;
23 const size_t total_len = prefix_len + name_len + 1;
24
25 if (!test_opt(inode->i_sb, XATTR_USER))
26 return 0;
27
28 if (list && total_len <= list_size) {
29 memcpy(list, XATTR_USER_PREFIX, prefix_len);
30 memcpy(list+prefix_len, name, name_len);
31 list[prefix_len + name_len] = '\0';
32 }
33 return total_len;
34}
35
36static int
37ext3_xattr_user_get(struct inode *inode, const char *name,
38 void *buffer, size_t size)
39{
40 int error;
41
42 if (strcmp(name, "") == 0)
43 return -EINVAL;
44 if (!test_opt(inode->i_sb, XATTR_USER))
45 return -EOPNOTSUPP;
46 error = permission(inode, MAY_READ, NULL);
47 if (error)
48 return error;
49
50 return ext3_xattr_get(inode, EXT3_XATTR_INDEX_USER, name, buffer, size);
51}
52
53static int
54ext3_xattr_user_set(struct inode *inode, const char *name,
55 const void *value, size_t size, int flags)
56{
57 int error;
58
59 if (strcmp(name, "") == 0)
60 return -EINVAL;
61 if (!test_opt(inode->i_sb, XATTR_USER))
62 return -EOPNOTSUPP;
63 if ( !S_ISREG(inode->i_mode) &&
64 (!S_ISDIR(inode->i_mode) || inode->i_mode & S_ISVTX))
65 return -EPERM;
66 error = permission(inode, MAY_WRITE, NULL);
67 if (error)
68 return error;
69
70 return ext3_xattr_set(inode, EXT3_XATTR_INDEX_USER, name,
71 value, size, flags);
72}
73
74struct xattr_handler ext3_xattr_user_handler = {
75 .prefix = XATTR_USER_PREFIX,
76 .list = ext3_xattr_user_list,
77 .get = ext3_xattr_user_get,
78 .set = ext3_xattr_user_set,
79};