xref: /openbmc/linux/fs/ext4/acl.h (revision 132db935)
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 
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 
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);
59 int ext4_set_acl(struct inode *inode, struct posix_acl *acl, int type);
60 extern int ext4_init_acl(handle_t *, struct inode *, struct inode *);
61 
62 #else  /* CONFIG_EXT4_FS_POSIX_ACL */
63 #include <linux/sched.h>
64 #define ext4_get_acl NULL
65 #define ext4_set_acl NULL
66 
67 static inline int
68 ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
69 {
70 	return 0;
71 }
72 #endif  /* CONFIG_EXT4_FS_POSIX_ACL */
73 
74