reiserfs: fix oops while creating privroot with selinux enabled
[linux-2.6.git] / fs / reiserfs / xattr_security.c
1 #include <linux/reiserfs_fs.h>
2 #include <linux/errno.h>
3 #include <linux/fs.h>
4 #include <linux/pagemap.h>
5 #include <linux/xattr.h>
6 #include <linux/reiserfs_xattr.h>
7 #include <linux/security.h>
8 #include <asm/uaccess.h>
9
10 static int
11 security_get(struct dentry *dentry, const char *name, void *buffer, size_t size,
12                 int handler_flags)
13 {
14         if (strlen(name) < sizeof(XATTR_SECURITY_PREFIX))
15                 return -EINVAL;
16
17         if (IS_PRIVATE(dentry->d_inode))
18                 return -EPERM;
19
20         return reiserfs_xattr_get(dentry->d_inode, name, buffer, size);
21 }
22
23 static int
24 security_set(struct dentry *dentry, const char *name, const void *buffer,
25              size_t size, int flags, int handler_flags)
26 {
27         if (strlen(name) < sizeof(XATTR_SECURITY_PREFIX))
28                 return -EINVAL;
29
30         if (IS_PRIVATE(dentry->d_inode))
31                 return -EPERM;
32
33         return reiserfs_xattr_set(dentry->d_inode, name, buffer, size, flags);
34 }
35
36 static size_t security_list(struct dentry *dentry, char *list, size_t list_len,
37                             const char *name, size_t namelen, int handler_flags)
38 {
39         const size_t len = namelen + 1;
40
41         if (IS_PRIVATE(dentry->d_inode))
42                 return 0;
43
44         if (list && len <= list_len) {
45                 memcpy(list, name, namelen);
46                 list[namelen] = '\0';
47         }
48
49         return len;
50 }
51
52 /* Initializes the security context for a new inode and returns the number
53  * of blocks needed for the transaction. If successful, reiserfs_security
54  * must be released using reiserfs_security_free when the caller is done. */
55 int reiserfs_security_init(struct inode *dir, struct inode *inode,
56                            struct reiserfs_security_handle *sec)
57 {
58         int blocks = 0;
59         int error;
60
61         sec->name = NULL;
62
63         /* Don't add selinux attributes on xattrs - they'll never get used */
64         if (IS_PRIVATE(dir))
65                 return 0;
66
67         error = security_inode_init_security(inode, dir, &sec->name,
68                                              &sec->value, &sec->length);
69         if (error) {
70                 if (error == -EOPNOTSUPP)
71                         error = 0;
72
73                 sec->name = NULL;
74                 sec->value = NULL;
75                 sec->length = 0;
76                 return error;
77         }
78
79         if (sec->length && reiserfs_xattrs_initialized(inode->i_sb)) {
80                 blocks = reiserfs_xattr_jcreate_nblocks(inode) +
81                          reiserfs_xattr_nblocks(inode, sec->length);
82                 /* We don't want to count the directories twice if we have
83                  * a default ACL. */
84                 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
85         }
86         return blocks;
87 }
88
89 int reiserfs_security_write(struct reiserfs_transaction_handle *th,
90                             struct inode *inode,
91                             struct reiserfs_security_handle *sec)
92 {
93         int error;
94         if (strlen(sec->name) < sizeof(XATTR_SECURITY_PREFIX))
95                 return -EINVAL;
96
97         error = reiserfs_xattr_set_handle(th, inode, sec->name, sec->value,
98                                           sec->length, XATTR_CREATE);
99         if (error == -ENODATA || error == -EOPNOTSUPP)
100                 error = 0;
101
102         return error;
103 }
104
105 void reiserfs_security_free(struct reiserfs_security_handle *sec)
106 {
107         kfree(sec->name);
108         kfree(sec->value);
109         sec->name = NULL;
110         sec->value = NULL;
111 }
112
113 struct xattr_handler reiserfs_xattr_security_handler = {
114         .prefix = XATTR_SECURITY_PREFIX,
115         .get = security_get,
116         .set = security_set,
117         .list = security_list,
118 };