1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
/*
File: linux/posix_acl.h
(C) 2002 Andreas Gruenbacher, <a.gruenbacher@computer.org>
*/
#ifndef __LINUX_POSIX_ACL_H
#define __LINUX_POSIX_ACL_H
#include <linux/slab.h>
#define ACL_UNDEFINED_ID (-1)
/* a_type field in acl_user_posix_entry_t */
#define ACL_TYPE_ACCESS (0x8000)
#define ACL_TYPE_DEFAULT (0x4000)
/* e_tag entry in struct posix_acl_entry */
#define ACL_USER_OBJ (0x01)
#define ACL_USER (0x02)
#define ACL_GROUP_OBJ (0x04)
#define ACL_GROUP (0x08)
#define ACL_MASK (0x10)
#define ACL_OTHER (0x20)
/* permissions in the e_perm field */
#define ACL_READ (0x04)
#define ACL_WRITE (0x02)
#define ACL_EXECUTE (0x01)
//#define ACL_ADD (0x08)
//#define ACL_DELETE (0x10)
struct posix_acl_entry {
short e_tag;
unsigned short e_perm;
unsigned int e_id;
};
struct posix_acl {
atomic_t a_refcount;
unsigned int a_count;
struct posix_acl_entry a_entries[0];
};
#define FOREACH_ACL_ENTRY(pa, acl, pe) \
for(pa=(acl)->a_entries, pe=pa+(acl)->a_count; pa<pe; pa++)
/*
* Duplicate an ACL handle.
*/
static inline struct posix_acl *
posix_acl_dup(struct posix_acl *acl)
{
if (acl)
atomic_inc(&acl->a_refcount);
return acl;
}
/*
* Free an ACL handle.
*/
static inline void
posix_acl_release(struct posix_acl *acl)
{
if (acl && atomic_dec_and_test(&acl->a_refcount))
kfree(acl);
}
/* posix_acl.c */
extern void posix_acl_init(struct posix_acl *, int);
extern struct posix_acl *posix_acl_alloc(int, gfp_t);
extern int posix_acl_valid(const struct posix_acl *);
extern int posix_acl_permission(struct inode *, const struct posix_acl *, int);
extern struct posix_acl *posix_acl_from_mode(mode_t, gfp_t);
extern int posix_acl_equiv_mode(const struct posix_acl *, mode_t *);
extern int posix_acl_create(struct posix_acl **, gfp_t, mode_t *);
extern int posix_acl_chmod(struct posix_acl **, gfp_t, mode_t);
extern struct posix_acl *get_posix_acl(struct inode *, int);
extern int set_posix_acl(struct inode *, int, struct posix_acl *);
#ifdef CONFIG_FS_POSIX_ACL
static inline struct posix_acl *get_cached_acl(struct inode *inode, int type)
{
struct posix_acl **p, *acl;
switch (type) {
case ACL_TYPE_ACCESS:
p = &inode->i_acl;
break;
case ACL_TYPE_DEFAULT:
p = &inode->i_default_acl;
break;
default:
return ERR_PTR(-EINVAL);
}
acl = ACCESS_ONCE(*p);
if (acl) {
spin_lock(&inode->i_lock);
acl = *p;
if (acl != ACL_NOT_CACHED)
acl = posix_acl_dup(acl);
spin_unlock(&inode->i_lock);
}
return acl;
}
static inline int negative_cached_acl(struct inode *inode, int type)
{
struct posix_acl **p, *acl;
switch (type) {
case ACL_TYPE_ACCESS:
p = &inode->i_acl;
break;
case ACL_TYPE_DEFAULT:
p = &inode->i_default_acl;
break;
default:
BUG();
}
acl = ACCESS_ONCE(*p);
if (acl)
return 0;
return 1;
}
static inline void set_cached_acl(struct inode *inode,
int type,
struct posix_acl *acl)
{
struct posix_acl *old = NULL;
spin_lock(&inode->i_lock);
switch (type) {
case ACL_TYPE_ACCESS:
old = inode->i_acl;
inode->i_acl = posix_acl_dup(acl);
break;
case ACL_TYPE_DEFAULT:
old = inode->i_default_acl;
inode->i_default_acl = posix_acl_dup(acl);
break;
}
spin_unlock(&inode->i_lock);
if (old != ACL_NOT_CACHED)
posix_acl_release(old);
}
static inline void forget_cached_acl(struct inode *inode, int type)
{
struct posix_acl *old = NULL;
spin_lock(&inode->i_lock);
switch (type) {
case ACL_TYPE_ACCESS:
old = inode->i_acl;
inode->i_acl = ACL_NOT_CACHED;
break;
case ACL_TYPE_DEFAULT:
old = inode->i_default_acl;
inode->i_default_acl = ACL_NOT_CACHED;
break;
}
spin_unlock(&inode->i_lock);
if (old != ACL_NOT_CACHED)
posix_acl_release(old);
}
static inline void forget_all_cached_acls(struct inode *inode)
{
struct posix_acl *old_access, *old_default;
spin_lock(&inode->i_lock);
old_access = inode->i_acl;
old_default = inode->i_default_acl;
inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED;
spin_unlock(&inode->i_lock);
if (old_access != ACL_NOT_CACHED)
posix_acl_release(old_access);
if (old_default != ACL_NOT_CACHED)
posix_acl_release(old_default);
}
#endif
static inline void cache_no_acl(struct inode *inode)
{
#ifdef CONFIG_FS_POSIX_ACL
inode->i_acl = NULL;
inode->i_default_acl = NULL;
#endif
}
#endif /* __LINUX_POSIX_ACL_H */
|
