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;
42 #ifndef CONFIG_UIDGID_STRICT_TYPE_CHECKS
51 struct rcu_head a_rcu;
54 struct posix_acl_entry a_entries[0];
57 #define FOREACH_ACL_ENTRY(pa, acl, pe) \
58 for(pa=(acl)->a_entries, pe=pa+(acl)->a_count; pa<pe; pa++)
62 * Duplicate an ACL handle.
64 static inline struct posix_acl *
65 posix_acl_dup(struct posix_acl *acl)
68 atomic_inc(&acl->a_refcount);
76 posix_acl_release(struct posix_acl *acl)
78 if (acl && atomic_dec_and_test(&acl->a_refcount))
79 kfree_rcu(acl, a_rcu);
85 extern void posix_acl_init(struct posix_acl *, int);
86 extern struct posix_acl *posix_acl_alloc(int, gfp_t);
87 extern int posix_acl_valid(const struct posix_acl *);
88 extern int posix_acl_permission(struct inode *, const struct posix_acl *, int);
89 extern struct posix_acl *posix_acl_from_mode(umode_t, gfp_t);
90 extern int posix_acl_equiv_mode(const struct posix_acl *, umode_t *);
91 extern int __posix_acl_create(struct posix_acl **, gfp_t, umode_t *);
92 extern int __posix_acl_chmod(struct posix_acl **, gfp_t, umode_t);
94 extern struct posix_acl *get_posix_acl(struct inode *, int);
95 extern int set_posix_acl(struct inode *, int, struct posix_acl *);
97 #ifdef CONFIG_FS_POSIX_ACL
98 extern int posix_acl_chmod(struct inode *, umode_t);
99 extern int posix_acl_create(struct inode *, umode_t *, struct posix_acl **,
100 struct posix_acl **);
102 extern int simple_set_acl(struct inode *, struct posix_acl *, int);
103 extern int simple_acl_create(struct inode *, struct inode *);
105 static inline struct posix_acl **acl_by_type(struct inode *inode, int type)
108 case ACL_TYPE_ACCESS:
109 return &inode->i_acl;
110 case ACL_TYPE_DEFAULT:
111 return &inode->i_default_acl;
117 static inline struct posix_acl *get_cached_acl(struct inode *inode, int type)
119 struct posix_acl **p = acl_by_type(inode, type);
120 struct posix_acl *acl = ACCESS_ONCE(*p);
122 spin_lock(&inode->i_lock);
124 if (acl != ACL_NOT_CACHED)
125 acl = posix_acl_dup(acl);
126 spin_unlock(&inode->i_lock);
131 static inline struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type)
133 return rcu_dereference(*acl_by_type(inode, type));
136 static inline void set_cached_acl(struct inode *inode,
138 struct posix_acl *acl)
140 struct posix_acl **p = acl_by_type(inode, type);
141 struct posix_acl *old;
142 spin_lock(&inode->i_lock);
144 rcu_assign_pointer(*p, posix_acl_dup(acl));
145 spin_unlock(&inode->i_lock);
146 if (old != ACL_NOT_CACHED)
147 posix_acl_release(old);
150 static inline void forget_cached_acl(struct inode *inode, int type)
152 struct posix_acl **p = acl_by_type(inode, type);
153 struct posix_acl *old;
154 spin_lock(&inode->i_lock);
157 spin_unlock(&inode->i_lock);
158 if (old != ACL_NOT_CACHED)
159 posix_acl_release(old);
162 static inline void forget_all_cached_acls(struct inode *inode)
164 struct posix_acl *old_access, *old_default;
165 spin_lock(&inode->i_lock);
166 old_access = inode->i_acl;
167 old_default = inode->i_default_acl;
168 inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED;
169 spin_unlock(&inode->i_lock);
170 if (old_access != ACL_NOT_CACHED)
171 posix_acl_release(old_access);
172 if (old_default != ACL_NOT_CACHED)
173 posix_acl_release(old_default);
176 static inline void cache_no_acl(struct inode *inode)
179 inode->i_default_acl = NULL;
182 static inline int posix_acl_chmod(struct inode *inode, umode_t mode)
187 #define simple_set_acl NULL
189 static inline int simple_acl_create(struct inode *dir, struct inode *inode)
193 static inline void cache_no_acl(struct inode *inode)
197 static inline int posix_acl_create(struct inode *inode, umode_t *mode,
198 struct posix_acl **default_acl, struct posix_acl **acl)
200 *default_acl = *acl = NULL;
204 static inline void forget_all_cached_acls(struct inode *inode)
207 #endif /* CONFIG_FS_POSIX_ACL */
209 struct posix_acl *get_acl(struct inode *inode, int type);
211 #endif /* __LINUX_POSIX_ACL_H */