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 | ||
187f1882 | 11 | #include <linux/bug.h> |
1da177e4 | 12 | #include <linux/slab.h> |
3567866b | 13 | #include <linux/rcupdate.h> |
1da177e4 LT |
14 | |
15 | #define ACL_UNDEFINED_ID (-1) | |
16 | ||
17 | /* a_type field in acl_user_posix_entry_t */ | |
18 | #define ACL_TYPE_ACCESS (0x8000) | |
19 | #define ACL_TYPE_DEFAULT (0x4000) | |
20 | ||
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) | |
28 | ||
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) | |
35 | ||
36 | struct posix_acl_entry { | |
37 | short e_tag; | |
38 | unsigned short e_perm; | |
2f6f0654 EB |
39 | union { |
40 | kuid_t e_uid; | |
41 | kgid_t e_gid; | |
42 | #ifndef CONFIG_UIDGID_STRICT_TYPE_CHECKS | |
43 | unsigned int e_id; | |
44 | #endif | |
45 | }; | |
1da177e4 LT |
46 | }; |
47 | ||
48 | struct posix_acl { | |
3567866b AV |
49 | union { |
50 | atomic_t a_refcount; | |
51 | struct rcu_head a_rcu; | |
52 | }; | |
1da177e4 LT |
53 | unsigned int a_count; |
54 | struct posix_acl_entry a_entries[0]; | |
55 | }; | |
56 | ||
57 | #define FOREACH_ACL_ENTRY(pa, acl, pe) \ | |
58 | for(pa=(acl)->a_entries, pe=pa+(acl)->a_count; pa<pe; pa++) | |
59 | ||
60 | ||
61 | /* | |
62 | * Duplicate an ACL handle. | |
63 | */ | |
64 | static inline struct posix_acl * | |
65 | posix_acl_dup(struct posix_acl *acl) | |
66 | { | |
67 | if (acl) | |
68 | atomic_inc(&acl->a_refcount); | |
69 | return acl; | |
70 | } | |
71 | ||
72 | /* | |
73 | * Free an ACL handle. | |
74 | */ | |
75 | static inline void | |
76 | posix_acl_release(struct posix_acl *acl) | |
77 | { | |
78 | if (acl && atomic_dec_and_test(&acl->a_refcount)) | |
3567866b | 79 | kfree_rcu(acl, a_rcu); |
1da177e4 LT |
80 | } |
81 | ||
82 | ||
83 | /* posix_acl.c */ | |
84 | ||
f61f6da0 | 85 | extern void posix_acl_init(struct posix_acl *, int); |
dd0fc66f | 86 | extern struct posix_acl *posix_acl_alloc(int, gfp_t); |
1da177e4 LT |
87 | extern int posix_acl_valid(const struct posix_acl *); |
88 | extern int posix_acl_permission(struct inode *, const struct posix_acl *, int); | |
3a5fba19 | 89 | extern struct posix_acl *posix_acl_from_mode(umode_t, gfp_t); |
d6952123 | 90 | extern int posix_acl_equiv_mode(const struct posix_acl *, umode_t *); |
d3fb6120 | 91 | extern int posix_acl_create(struct posix_acl **, gfp_t, umode_t *); |
86bc704d | 92 | extern int posix_acl_chmod(struct posix_acl **, gfp_t, umode_t); |
1da177e4 LT |
93 | |
94 | extern struct posix_acl *get_posix_acl(struct inode *, int); | |
95 | extern int set_posix_acl(struct inode *, int, struct posix_acl *); | |
96 | ||
641cf4a6 | 97 | #ifdef CONFIG_FS_POSIX_ACL |
951c0d66 | 98 | static inline struct posix_acl **acl_by_type(struct inode *inode, int type) |
073aaa1b | 99 | { |
073aaa1b AV |
100 | switch (type) { |
101 | case ACL_TYPE_ACCESS: | |
951c0d66 | 102 | return &inode->i_acl; |
073aaa1b | 103 | case ACL_TYPE_DEFAULT: |
951c0d66 | 104 | return &inode->i_default_acl; |
073aaa1b | 105 | default: |
951c0d66 | 106 | BUG(); |
073aaa1b | 107 | } |
951c0d66 AV |
108 | } |
109 | ||
110 | static inline struct posix_acl *get_cached_acl(struct inode *inode, int type) | |
111 | { | |
112 | struct posix_acl **p = acl_by_type(inode, type); | |
113 | struct posix_acl *acl = ACCESS_ONCE(*p); | |
073aaa1b AV |
114 | if (acl) { |
115 | spin_lock(&inode->i_lock); | |
116 | acl = *p; | |
117 | if (acl != ACL_NOT_CACHED) | |
118 | acl = posix_acl_dup(acl); | |
119 | spin_unlock(&inode->i_lock); | |
120 | } | |
121 | return acl; | |
122 | } | |
123 | ||
3567866b | 124 | static inline struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type) |
1e1743eb | 125 | { |
3567866b | 126 | return rcu_dereference(*acl_by_type(inode, type)); |
1e1743eb NP |
127 | } |
128 | ||
073aaa1b AV |
129 | static inline void set_cached_acl(struct inode *inode, |
130 | int type, | |
131 | struct posix_acl *acl) | |
132 | { | |
951c0d66 AV |
133 | struct posix_acl **p = acl_by_type(inode, type); |
134 | struct posix_acl *old; | |
073aaa1b | 135 | spin_lock(&inode->i_lock); |
951c0d66 | 136 | old = *p; |
3567866b | 137 | rcu_assign_pointer(*p, posix_acl_dup(acl)); |
073aaa1b AV |
138 | spin_unlock(&inode->i_lock); |
139 | if (old != ACL_NOT_CACHED) | |
140 | posix_acl_release(old); | |
141 | } | |
142 | ||
143 | static inline void forget_cached_acl(struct inode *inode, int type) | |
144 | { | |
951c0d66 AV |
145 | struct posix_acl **p = acl_by_type(inode, type); |
146 | struct posix_acl *old; | |
073aaa1b | 147 | spin_lock(&inode->i_lock); |
951c0d66 AV |
148 | old = *p; |
149 | *p = ACL_NOT_CACHED; | |
073aaa1b AV |
150 | spin_unlock(&inode->i_lock); |
151 | if (old != ACL_NOT_CACHED) | |
152 | posix_acl_release(old); | |
153 | } | |
796bd952 SW |
154 | |
155 | static inline void forget_all_cached_acls(struct inode *inode) | |
156 | { | |
157 | struct posix_acl *old_access, *old_default; | |
158 | spin_lock(&inode->i_lock); | |
159 | old_access = inode->i_acl; | |
160 | old_default = inode->i_default_acl; | |
161 | inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED; | |
162 | spin_unlock(&inode->i_lock); | |
163 | if (old_access != ACL_NOT_CACHED) | |
164 | posix_acl_release(old_access); | |
165 | if (old_default != ACL_NOT_CACHED) | |
166 | posix_acl_release(old_default); | |
167 | } | |
641cf4a6 | 168 | #endif |
72c04902 AV |
169 | |
170 | static inline void cache_no_acl(struct inode *inode) | |
171 | { | |
172 | #ifdef CONFIG_FS_POSIX_ACL | |
173 | inode->i_acl = NULL; | |
174 | inode->i_default_acl = NULL; | |
175 | #endif | |
176 | } | |
177 | ||
1da177e4 | 178 | #endif /* __LINUX_POSIX_ACL_H */ |