xref: /openbmc/linux/fs/ext4/acl.h (revision 22246614)
1 /*
2   File: fs/ext4/acl.h
3 
4   (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
5 */
6 
7 #include <linux/posix_acl_xattr.h>
8 
9 #define EXT4_ACL_VERSION	0x0001
10 
11 typedef struct {
12 	__le16		e_tag;
13 	__le16		e_perm;
14 	__le32		e_id;
15 } ext4_acl_entry;
16 
17 typedef struct {
18 	__le16		e_tag;
19 	__le16		e_perm;
20 } ext4_acl_entry_short;
21 
22 typedef struct {
23 	__le32		a_version;
24 } ext4_acl_header;
25 
26 static inline size_t ext4_acl_size(int count)
27 {
28 	if (count <= 4) {
29 		return sizeof(ext4_acl_header) +
30 		       count * sizeof(ext4_acl_entry_short);
31 	} else {
32 		return sizeof(ext4_acl_header) +
33 		       4 * sizeof(ext4_acl_entry_short) +
34 		       (count - 4) * sizeof(ext4_acl_entry);
35 	}
36 }
37 
38 static inline int ext4_acl_count(size_t size)
39 {
40 	ssize_t s;
41 	size -= sizeof(ext4_acl_header);
42 	s = size - 4 * sizeof(ext4_acl_entry_short);
43 	if (s < 0) {
44 		if (size % sizeof(ext4_acl_entry_short))
45 			return -1;
46 		return size / sizeof(ext4_acl_entry_short);
47 	} else {
48 		if (s % sizeof(ext4_acl_entry))
49 			return -1;
50 		return s / sizeof(ext4_acl_entry) + 4;
51 	}
52 }
53 
54 #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
55 
56 /* Value for inode->u.ext4_i.i_acl and inode->u.ext4_i.i_default_acl
57    if the ACL has not been cached */
58 #define EXT4_ACL_NOT_CACHED ((void *)-1)
59 
60 /* acl.c */
61 extern int ext4_permission (struct inode *, int, struct nameidata *);
62 extern int ext4_acl_chmod (struct inode *);
63 extern int ext4_init_acl (handle_t *, struct inode *, struct inode *);
64 
65 #else  /* CONFIG_EXT4DEV_FS_POSIX_ACL */
66 #include <linux/sched.h>
67 #define ext4_permission NULL
68 
69 static inline int
70 ext4_acl_chmod(struct inode *inode)
71 {
72 	return 0;
73 }
74 
75 static inline int
76 ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
77 {
78 	return 0;
79 }
80 #endif  /* CONFIG_EXT4DEV_FS_POSIX_ACL */
81 
82