2 File: linux/posix_acl.h
4 (C) 2002 Andreas Gruenbacher, <a.gruenbacher@computer.org>
8 #ifndef __LINUX_POSIX_ACL_H
9 #define __LINUX_POSIX_ACL_H
11 #include <linux/bug.h>
12 #include <linux/slab.h>
13 #include <linux/rcupdate.h>
15 #define ACL_UNDEFINED_ID (-1)
17 /* a_type field in acl_user_posix_entry_t */
18 #define ACL_TYPE_ACCESS (0x8000)
19 #define ACL_TYPE_DEFAULT (0x4000)
21 /* e_tag entry in struct posix_acl_entry */
22 #define ACL_USER_OBJ (0x01)
23 #define ACL_USER (0x02)
24 #define ACL_GROUP_OBJ (0x04)
25 #define ACL_GROUP (0x08)
26 #define ACL_MASK (0x10)
27 #define ACL_OTHER (0x20)
29 /* permissions in the e_perm field */
30 #define ACL_READ (0x04)
31 #define ACL_WRITE (0x02)
32 #define ACL_EXECUTE (0x01)
33 //#define ACL_ADD (0x08)
34 //#define ACL_DELETE (0x10)
36 struct posix_acl_entry
{
38 unsigned short e_perm
;
45 struct rcu_head a_rcu
;
48 struct posix_acl_entry a_entries
[0];
51 #define FOREACH_ACL_ENTRY(pa, acl, pe) \
52 for(pa=(acl)->a_entries, pe=pa+(acl)->a_count; pa<pe; pa++)
56 * Duplicate an ACL handle.
58 static inline struct posix_acl
*
59 posix_acl_dup(struct posix_acl
*acl
)
62 atomic_inc(&acl
->a_refcount
);
70 posix_acl_release(struct posix_acl
*acl
)
72 if (acl
&& atomic_dec_and_test(&acl
->a_refcount
))
73 kfree_rcu(acl
, a_rcu
);
79 extern void posix_acl_init(struct posix_acl
*, int);
80 extern struct posix_acl
*posix_acl_alloc(int, gfp_t
);
81 extern int posix_acl_valid(const struct posix_acl
*);
82 extern int posix_acl_permission(struct inode
*, const struct posix_acl
*, int);
83 extern struct posix_acl
*posix_acl_from_mode(umode_t
, gfp_t
);
84 extern int posix_acl_equiv_mode(const struct posix_acl
*, umode_t
*);
85 extern int posix_acl_create(struct posix_acl
**, gfp_t
, umode_t
*);
86 extern int posix_acl_chmod(struct posix_acl
**, gfp_t
, umode_t
);
88 extern struct posix_acl
*get_posix_acl(struct inode
*, int);
89 extern int set_posix_acl(struct inode
*, int, struct posix_acl
*);
91 #ifdef CONFIG_FS_POSIX_ACL
92 static inline struct posix_acl
**acl_by_type(struct inode
*inode
, int type
)
97 case ACL_TYPE_DEFAULT
:
98 return &inode
->i_default_acl
;
104 static inline struct posix_acl
*get_cached_acl(struct inode
*inode
, int type
)
106 struct posix_acl
**p
= acl_by_type(inode
, type
);
107 struct posix_acl
*acl
= ACCESS_ONCE(*p
);
109 spin_lock(&inode
->i_lock
);
111 if (acl
!= ACL_NOT_CACHED
)
112 acl
= posix_acl_dup(acl
);
113 spin_unlock(&inode
->i_lock
);
118 static inline struct posix_acl
*get_cached_acl_rcu(struct inode
*inode
, int type
)
120 return rcu_dereference(*acl_by_type(inode
, type
));
123 static inline void set_cached_acl(struct inode
*inode
,
125 struct posix_acl
*acl
)
127 struct posix_acl
**p
= acl_by_type(inode
, type
);
128 struct posix_acl
*old
;
129 spin_lock(&inode
->i_lock
);
131 rcu_assign_pointer(*p
, posix_acl_dup(acl
));
132 spin_unlock(&inode
->i_lock
);
133 if (old
!= ACL_NOT_CACHED
)
134 posix_acl_release(old
);
137 static inline void forget_cached_acl(struct inode
*inode
, int type
)
139 struct posix_acl
**p
= acl_by_type(inode
, type
);
140 struct posix_acl
*old
;
141 spin_lock(&inode
->i_lock
);
144 spin_unlock(&inode
->i_lock
);
145 if (old
!= ACL_NOT_CACHED
)
146 posix_acl_release(old
);
149 static inline void forget_all_cached_acls(struct inode
*inode
)
151 struct posix_acl
*old_access
, *old_default
;
152 spin_lock(&inode
->i_lock
);
153 old_access
= inode
->i_acl
;
154 old_default
= inode
->i_default_acl
;
155 inode
->i_acl
= inode
->i_default_acl
= ACL_NOT_CACHED
;
156 spin_unlock(&inode
->i_lock
);
157 if (old_access
!= ACL_NOT_CACHED
)
158 posix_acl_release(old_access
);
159 if (old_default
!= ACL_NOT_CACHED
)
160 posix_acl_release(old_default
);
164 static inline void cache_no_acl(struct inode
*inode
)
166 #ifdef CONFIG_FS_POSIX_ACL
168 inode
->i_default_acl
= NULL
;
172 #endif /* __LINUX_POSIX_ACL_H */