1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 File: fs/ext4/acl.h
4
5 (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
6 */
7
8 #include <linux/posix_acl_xattr.h>
9
10 #define EXT4_ACL_VERSION 0x0001
11
12 typedef struct {
13 __le16 e_tag;
14 __le16 e_perm;
15 __le32 e_id;
16 } ext4_acl_entry;
17
18 typedef struct {
19 __le16 e_tag;
20 __le16 e_perm;
21 } ext4_acl_entry_short;
22
23 typedef struct {
24 __le32 a_version;
25 } ext4_acl_header;
26
ext4_acl_size(int count)27 static inline size_t ext4_acl_size(int count)
28 {
29 if (count <= 4) {
30 return sizeof(ext4_acl_header) +
31 count * sizeof(ext4_acl_entry_short);
32 } else {
33 return sizeof(ext4_acl_header) +
34 4 * sizeof(ext4_acl_entry_short) +
35 (count - 4) * sizeof(ext4_acl_entry);
36 }
37 }
38
ext4_acl_count(size_t size)39 static inline int ext4_acl_count(size_t size)
40 {
41 ssize_t s;
42 size -= sizeof(ext4_acl_header);
43 s = size - 4 * sizeof(ext4_acl_entry_short);
44 if (s < 0) {
45 if (size % sizeof(ext4_acl_entry_short))
46 return -1;
47 return size / sizeof(ext4_acl_entry_short);
48 } else {
49 if (s % sizeof(ext4_acl_entry))
50 return -1;
51 return s / sizeof(ext4_acl_entry) + 4;
52 }
53 }
54
55 #ifdef CONFIG_EXT4_FS_POSIX_ACL
56
57 /* acl.c */
58 struct posix_acl *ext4_get_acl(struct inode *inode, int type, bool rcu);
59 int ext4_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
60 struct posix_acl *acl, int type);
61 extern int ext4_init_acl(handle_t *, struct inode *, struct inode *);
62
63 #else /* CONFIG_EXT4_FS_POSIX_ACL */
64 #include <linux/sched.h>
65 #define ext4_get_acl NULL
66 #define ext4_set_acl NULL
67
68 static inline int
ext4_init_acl(handle_t * handle,struct inode * inode,struct inode * dir)69 ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
70 {
71 /* usually, the umask is applied by posix_acl_create(), but if
72 ext4 ACL support is disabled at compile time, we need to do
73 it here, because posix_acl_create() will never be called */
74 inode->i_mode &= ~current_umask();
75
76 return 0;
77 }
78 #endif /* CONFIG_EXT4_FS_POSIX_ACL */
79
80