oom: suppress nodes that are not allowed from meminfo on oom kill
[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/slab.h>
7 #include <linux/reiserfs_xattr.h>
8 #include <linux/security.h>
9 #include <asm/uaccess.h>
10
11 static int
12 security_get(struct dentry *dentry, const char *name, void *buffer, size_t size,
13                 int handler_flags)
14 {
15         if (strlen(name) < sizeof(XATTR_SECURITY_PREFIX))
16                 return -EINVAL;
17
18         if (IS_PRIVATE(dentry->d_inode))
19                 return -EPERM;
20
21         return reiserfs_xattr_get(dentry->d_inode, name, buffer, size);
22 }
23
24 static int
25 security_set(struct dentry *dentry, const char *name, const void *buffer,
26              size_t size, int flags, int handler_flags)
27 {
28         if (strlen(name) < sizeof(XATTR_SECURITY_PREFIX))
29                 return -EINVAL;
30
31         if (IS_PRIVATE(dentry->d_inode))
32                 return -EPERM;
33
34         return reiserfs_xattr_set(dentry->d_inode, name, buffer, size, flags);
35 }
36
37 static size_t security_list(struct dentry *dentry, char *list, size_t list_len,
38                             const char *name, size_t namelen, int handler_flags)
39 {
40         const size_t len = namelen + 1;
41
42         if (IS_PRIVATE(dentry->d_inode))
43                 return 0;
44
45         if (list && len <= list_len) {
46                 memcpy(list, name, namelen);
47                 list[namelen] = '\0';
48         }
49
50         return len;
51 }
52
53 /* Initializes the security context for a new inode and returns the number
54  * of blocks needed for the transaction. If successful, reiserfs_security
55  * must be released using reiserfs_security_free when the caller is done. */
56 int reiserfs_security_init(struct inode *dir, struct inode *inode,
57                            const struct qstr *qstr,
58                            struct reiserfs_security_handle *sec)
59 {
60         int blocks = 0;
61         int error;
62
63         sec->name = NULL;
64
65         /* Don't add selinux attributes on xattrs - they'll never get used */
66         if (IS_PRIVATE(dir))
67                 return 0;
68
69         error = security_inode_init_security(inode, dir, qstr, &sec->name,
70                                              &sec->value, &sec->length);
71         if (error) {
72                 if (error == -EOPNOTSUPP)
73                         error = 0;
74
75                 sec->name = NULL;
76                 sec->value = NULL;
77                 sec->length = 0;
78                 return error;
79         }
80
81         if (sec->length && reiserfs_xattrs_initialized(inode->i_sb)) {
82                 blocks = reiserfs_xattr_jcreate_nblocks(inode) +
83                          reiserfs_xattr_nblocks(inode, sec->length);
84                 /* We don't want to count the directories twice if we have
85                  * a default ACL. */
86                 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
87         }
88         return blocks;
89 }
90
91 int reiserfs_security_write(struct reiserfs_transaction_handle *th,
92                             struct inode *inode,
93                             struct reiserfs_security_handle *sec)
94 {
95         int error;
96         if (strlen(sec->name) < sizeof(XATTR_SECURITY_PREFIX))
97                 return -EINVAL;
98
99         error = reiserfs_xattr_set_handle(th, inode, sec->name, sec->value,
100                                           sec->length, XATTR_CREATE);
101         if (error == -ENODATA || error == -EOPNOTSUPP)
102                 error = 0;
103
104         return error;
105 }
106
107 void reiserfs_security_free(struct reiserfs_security_handle *sec)
108 {
109         kfree(sec->name);
110         kfree(sec->value);
111         sec->name = NULL;
112         sec->value = NULL;
113 }
114
115 const struct xattr_handler reiserfs_xattr_security_handler = {
116         .prefix = XATTR_SECURITY_PREFIX,
117         .get = security_get,
118         .set = security_set,
119         .list = security_list,
120 };