ext2: speed up file creates by optimizing rec_len functions
[linux-2.6.git] / fs / ext2 / xattr_security.c
1 /*
2  * linux/fs/ext2/xattr_security.c
3  * Handler for storing security labels as extended attributes.
4  */
5
6 #include <linux/module.h>
7 #include <linux/slab.h>
8 #include <linux/string.h>
9 #include <linux/fs.h>
10 #include <linux/ext2_fs.h>
11 #include <linux/security.h>
12 #include "xattr.h"
13
14 static size_t
15 ext2_xattr_security_list(struct dentry *dentry, char *list, size_t list_size,
16                          const char *name, size_t name_len, int type)
17 {
18         const int prefix_len = XATTR_SECURITY_PREFIX_LEN;
19         const size_t total_len = prefix_len + name_len + 1;
20
21         if (list && total_len <= list_size) {
22                 memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
23                 memcpy(list+prefix_len, name, name_len);
24                 list[prefix_len + name_len] = '\0';
25         }
26         return total_len;
27 }
28
29 static int
30 ext2_xattr_security_get(struct dentry *dentry, const char *name,
31                        void *buffer, size_t size, int type)
32 {
33         if (strcmp(name, "") == 0)
34                 return -EINVAL;
35         return ext2_xattr_get(dentry->d_inode, EXT2_XATTR_INDEX_SECURITY, name,
36                               buffer, size);
37 }
38
39 static int
40 ext2_xattr_security_set(struct dentry *dentry, const char *name,
41                 const void *value, size_t size, int flags, int type)
42 {
43         if (strcmp(name, "") == 0)
44                 return -EINVAL;
45         return ext2_xattr_set(dentry->d_inode, EXT2_XATTR_INDEX_SECURITY, name,
46                               value, size, flags);
47 }
48
49 int
50 ext2_init_security(struct inode *inode, struct inode *dir)
51 {
52         int err;
53         size_t len;
54         void *value;
55         char *name;
56
57         err = security_inode_init_security(inode, dir, &name, &value, &len);
58         if (err) {
59                 if (err == -EOPNOTSUPP)
60                         return 0;
61                 return err;
62         }
63         err = ext2_xattr_set(inode, EXT2_XATTR_INDEX_SECURITY,
64                              name, value, len, 0);
65         kfree(name);
66         kfree(value);
67         return err;
68 }
69
70 const struct xattr_handler ext2_xattr_security_handler = {
71         .prefix = XATTR_SECURITY_PREFIX,
72         .list   = ext2_xattr_security_list,
73         .get    = ext2_xattr_security_get,
74         .set    = ext2_xattr_security_set,
75 };