xref: /linux/fs/ext2/acl.h (revision 43d5f5d63699724d47f0d9e0eae516a260d232b4)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3   File: fs/ext2/acl.h
4 
5   (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
6 */
7 
8 #include <linux/posix_acl_xattr.h>
9 
10 #define EXT2_ACL_VERSION	0x0001
11 
12 typedef struct {
13 	__le16		e_tag;
14 	__le16		e_perm;
15 	__le32		e_id;
16 } ext2_acl_entry;
17 
18 typedef struct {
19 	__le16		e_tag;
20 	__le16		e_perm;
21 } ext2_acl_entry_short;
22 
23 typedef struct {
24 	__le32		a_version;
25 } ext2_acl_header;
26 
27 static inline size_t ext2_acl_size(int count)
28 {
29 	if (count <= 4) {
30 		return sizeof(ext2_acl_header) +
31 		       count * sizeof(ext2_acl_entry_short);
32 	} else {
33 		return sizeof(ext2_acl_header) +
34 		       4 * sizeof(ext2_acl_entry_short) +
35 		       (count - 4) * sizeof(ext2_acl_entry);
36 	}
37 }
38 
39 static inline int ext2_acl_count(size_t size)
40 {
41 	ssize_t s;
42 	size -= sizeof(ext2_acl_header);
43 	s = size - 4 * sizeof(ext2_acl_entry_short);
44 	if (s < 0) {
45 		if (size % sizeof(ext2_acl_entry_short))
46 			return -1;
47 		return size / sizeof(ext2_acl_entry_short);
48 	} else {
49 		if (s % sizeof(ext2_acl_entry))
50 			return -1;
51 		return s / sizeof(ext2_acl_entry) + 4;
52 	}
53 }
54 
55 #ifdef CONFIG_EXT2_FS_POSIX_ACL
56 
57 /* acl.c */
58 extern struct posix_acl *ext2_get_acl(struct inode *inode, int type, bool rcu);
59 extern int ext2_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
60 			struct posix_acl *acl, int type);
61 extern int ext2_init_acl (struct inode *, struct inode *);
62 
63 #else
64 #include <linux/sched.h>
65 #define ext2_get_acl	NULL
66 #define ext2_set_acl	NULL
67 
68 static inline int ext2_init_acl (struct inode *inode, struct inode *dir)
69 {
70 	return 0;
71 }
72 #endif
73 
74