Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | File: linux/posix_acl.h | |
3 | ||
4 | (C) 2002 Andreas Gruenbacher, <a.gruenbacher@computer.org> | |
5 | */ | |
6 | ||
7 | ||
8 | #ifndef __LINUX_POSIX_ACL_H | |
9 | #define __LINUX_POSIX_ACL_H | |
10 | ||
11 | #include <linux/slab.h> | |
3567866b | 12 | #include <linux/rcupdate.h> |
1da177e4 LT |
13 | |
14 | #define ACL_UNDEFINED_ID (-1) | |
15 | ||
16 | /* a_type field in acl_user_posix_entry_t */ | |
17 | #define ACL_TYPE_ACCESS (0x8000) | |
18 | #define ACL_TYPE_DEFAULT (0x4000) | |
19 | ||
20 | /* e_tag entry in struct posix_acl_entry */ | |
21 | #define ACL_USER_OBJ (0x01) | |
22 | #define ACL_USER (0x02) | |
23 | #define ACL_GROUP_OBJ (0x04) | |
24 | #define ACL_GROUP (0x08) | |
25 | #define ACL_MASK (0x10) | |
26 | #define ACL_OTHER (0x20) | |
27 | ||
28 | /* permissions in the e_perm field */ | |
29 | #define ACL_READ (0x04) | |
30 | #define ACL_WRITE (0x02) | |
31 | #define ACL_EXECUTE (0x01) | |
32 | //#define ACL_ADD (0x08) | |
33 | //#define ACL_DELETE (0x10) | |
34 | ||
35 | struct posix_acl_entry { | |
36 | short e_tag; | |
37 | unsigned short e_perm; | |
38 | unsigned int e_id; | |
39 | }; | |
40 | ||
41 | struct posix_acl { | |
3567866b AV |
42 | union { |
43 | atomic_t a_refcount; | |
44 | struct rcu_head a_rcu; | |
45 | }; | |
1da177e4 LT |
46 | unsigned int a_count; |
47 | struct posix_acl_entry a_entries[0]; | |
48 | }; | |
49 | ||
50 | #define FOREACH_ACL_ENTRY(pa, acl, pe) \ | |
51 | for(pa=(acl)->a_entries, pe=pa+(acl)->a_count; pa<pe; pa++) | |
52 | ||
53 | ||
54 | /* | |
55 | * Duplicate an ACL handle. | |
56 | */ | |
57 | static inline struct posix_acl * | |
58 | posix_acl_dup(struct posix_acl *acl) | |
59 | { | |
60 | if (acl) | |
61 | atomic_inc(&acl->a_refcount); | |
62 | return acl; | |
63 | } | |
64 | ||
65 | /* | |
66 | * Free an ACL handle. | |
67 | */ | |
68 | static inline void | |
69 | posix_acl_release(struct posix_acl *acl) | |
70 | { | |
71 | if (acl && atomic_dec_and_test(&acl->a_refcount)) | |
3567866b | 72 | kfree_rcu(acl, a_rcu); |
1da177e4 LT |
73 | } |
74 | ||
75 | ||
76 | /* posix_acl.c */ | |
77 | ||
f61f6da0 | 78 | extern void posix_acl_init(struct posix_acl *, int); |
dd0fc66f | 79 | extern struct posix_acl *posix_acl_alloc(int, gfp_t); |
1da177e4 LT |
80 | extern int posix_acl_valid(const struct posix_acl *); |
81 | extern int posix_acl_permission(struct inode *, const struct posix_acl *, int); | |
3a5fba19 | 82 | extern struct posix_acl *posix_acl_from_mode(umode_t, gfp_t); |
d6952123 | 83 | extern int posix_acl_equiv_mode(const struct posix_acl *, umode_t *); |
d3fb6120 | 84 | extern int posix_acl_create(struct posix_acl **, gfp_t, umode_t *); |
86bc704d | 85 | extern int posix_acl_chmod(struct posix_acl **, gfp_t, umode_t); |
1da177e4 LT |
86 | |
87 | extern struct posix_acl *get_posix_acl(struct inode *, int); | |
88 | extern int set_posix_acl(struct inode *, int, struct posix_acl *); | |
89 | ||
641cf4a6 | 90 | #ifdef CONFIG_FS_POSIX_ACL |
951c0d66 | 91 | static inline struct posix_acl **acl_by_type(struct inode *inode, int type) |
073aaa1b | 92 | { |
073aaa1b AV |
93 | switch (type) { |
94 | case ACL_TYPE_ACCESS: | |
951c0d66 | 95 | return &inode->i_acl; |
073aaa1b | 96 | case ACL_TYPE_DEFAULT: |
951c0d66 | 97 | return &inode->i_default_acl; |
073aaa1b | 98 | default: |
951c0d66 | 99 | BUG(); |
073aaa1b | 100 | } |
951c0d66 AV |
101 | } |
102 | ||
103 | static inline struct posix_acl *get_cached_acl(struct inode *inode, int type) | |
104 | { | |
105 | struct posix_acl **p = acl_by_type(inode, type); | |
106 | struct posix_acl *acl = ACCESS_ONCE(*p); | |
073aaa1b AV |
107 | if (acl) { |
108 | spin_lock(&inode->i_lock); | |
109 | acl = *p; | |
110 | if (acl != ACL_NOT_CACHED) | |
111 | acl = posix_acl_dup(acl); | |
112 | spin_unlock(&inode->i_lock); | |
113 | } | |
114 | return acl; | |
115 | } | |
116 | ||
3567866b | 117 | static inline struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type) |
1e1743eb | 118 | { |
3567866b | 119 | return rcu_dereference(*acl_by_type(inode, type)); |
1e1743eb NP |
120 | } |
121 | ||
073aaa1b AV |
122 | static inline void set_cached_acl(struct inode *inode, |
123 | int type, | |
124 | struct posix_acl *acl) | |
125 | { | |
951c0d66 AV |
126 | struct posix_acl **p = acl_by_type(inode, type); |
127 | struct posix_acl *old; | |
073aaa1b | 128 | spin_lock(&inode->i_lock); |
951c0d66 | 129 | old = *p; |
3567866b | 130 | rcu_assign_pointer(*p, posix_acl_dup(acl)); |
073aaa1b AV |
131 | spin_unlock(&inode->i_lock); |
132 | if (old != ACL_NOT_CACHED) | |
133 | posix_acl_release(old); | |
134 | } | |
135 | ||
136 | static inline void forget_cached_acl(struct inode *inode, int type) | |
137 | { | |
951c0d66 AV |
138 | struct posix_acl **p = acl_by_type(inode, type); |
139 | struct posix_acl *old; | |
073aaa1b | 140 | spin_lock(&inode->i_lock); |
951c0d66 AV |
141 | old = *p; |
142 | *p = ACL_NOT_CACHED; | |
073aaa1b AV |
143 | spin_unlock(&inode->i_lock); |
144 | if (old != ACL_NOT_CACHED) | |
145 | posix_acl_release(old); | |
146 | } | |
796bd952 SW |
147 | |
148 | static inline void forget_all_cached_acls(struct inode *inode) | |
149 | { | |
150 | struct posix_acl *old_access, *old_default; | |
151 | spin_lock(&inode->i_lock); | |
152 | old_access = inode->i_acl; | |
153 | old_default = inode->i_default_acl; | |
154 | inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED; | |
155 | spin_unlock(&inode->i_lock); | |
156 | if (old_access != ACL_NOT_CACHED) | |
157 | posix_acl_release(old_access); | |
158 | if (old_default != ACL_NOT_CACHED) | |
159 | posix_acl_release(old_default); | |
160 | } | |
641cf4a6 | 161 | #endif |
72c04902 AV |
162 | |
163 | static inline void cache_no_acl(struct inode *inode) | |
164 | { | |
165 | #ifdef CONFIG_FS_POSIX_ACL | |
166 | inode->i_acl = NULL; | |
167 | inode->i_default_acl = NULL; | |
168 | #endif | |
169 | } | |
170 | ||
1da177e4 | 171 | #endif /* __LINUX_POSIX_ACL_H */ |