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
12typedef struct {
13	__le16		e_tag;
14	__le16		e_perm;
15	__le32		e_id;
16} ext4_acl_entry;
17
18typedef struct {
19	__le16		e_tag;
20	__le16		e_perm;
21} ext4_acl_entry_short;
22
23typedef struct {
24	__le32		a_version;
25} ext4_acl_header;
26
27static 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
39static 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 */
58struct posix_acl *ext4_get_acl(struct inode *inode, int type, bool rcu);
59int ext4_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
60		 struct posix_acl *acl, int type);
61extern 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
68static inline int
69ext4_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