Line data Source code
1 : /*
2 : * Copyright (C) 2007 Red Hat. All rights reserved.
3 : *
4 : * This program is free software; you can redistribute it and/or
5 : * modify it under the terms of the GNU General Public
6 : * License v2 as published by the Free Software Foundation.
7 : *
8 : * This program is distributed in the hope that it will be useful,
9 : * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 : * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 : * General Public License for more details.
12 : *
13 : * You should have received a copy of the GNU General Public
14 : * License along with this program; if not, write to the
15 : * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 : * Boston, MA 021110-1307, USA.
17 : */
18 :
19 : #include <linux/fs.h>
20 : #include <linux/string.h>
21 : #include <linux/xattr.h>
22 : #include <linux/posix_acl_xattr.h>
23 : #include <linux/posix_acl.h>
24 : #include <linux/sched.h>
25 : #include <linux/slab.h>
26 :
27 : #include "ctree.h"
28 : #include "btrfs_inode.h"
29 : #include "xattr.h"
30 :
31 125 : struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
32 : {
33 : int size;
34 : const char *name;
35 : char *value = NULL;
36 : struct posix_acl *acl;
37 :
38 125 : switch (type) {
39 : case ACL_TYPE_ACCESS:
40 : name = POSIX_ACL_XATTR_ACCESS;
41 : break;
42 : case ACL_TYPE_DEFAULT:
43 : name = POSIX_ACL_XATTR_DEFAULT;
44 103 : break;
45 : default:
46 0 : BUG();
47 : }
48 :
49 125 : size = __btrfs_getxattr(inode, name, "", 0);
50 125 : if (size > 0) {
51 0 : value = kzalloc(size, GFP_NOFS);
52 0 : if (!value)
53 : return ERR_PTR(-ENOMEM);
54 0 : size = __btrfs_getxattr(inode, name, value, size);
55 : }
56 125 : if (size > 0) {
57 0 : acl = posix_acl_from_xattr(&init_user_ns, value, size);
58 125 : } else if (size == -ENOENT || size == -ENODATA || size == 0) {
59 : /* FIXME, who returns -ENOENT? I think nobody */
60 : acl = NULL;
61 : } else {
62 : acl = ERR_PTR(-EIO);
63 : }
64 125 : kfree(value);
65 :
66 125 : if (!IS_ERR(acl))
67 125 : set_cached_acl(inode, type, acl);
68 :
69 125 : return acl;
70 : }
71 :
72 : /*
73 : * Needs to be called with fs_mutex held
74 : */
75 14 : static int __btrfs_set_acl(struct btrfs_trans_handle *trans,
76 : struct inode *inode, struct posix_acl *acl, int type)
77 : {
78 : int ret, size = 0;
79 : const char *name;
80 : char *value = NULL;
81 :
82 14 : switch (type) {
83 : case ACL_TYPE_ACCESS:
84 : name = POSIX_ACL_XATTR_ACCESS;
85 14 : if (acl) {
86 14 : ret = posix_acl_equiv_mode(acl, &inode->i_mode);
87 14 : if (ret < 0)
88 : return ret;
89 14 : if (ret == 0)
90 : acl = NULL;
91 : }
92 : ret = 0;
93 : break;
94 : case ACL_TYPE_DEFAULT:
95 0 : if (!S_ISDIR(inode->i_mode))
96 0 : return acl ? -EINVAL : 0;
97 : name = POSIX_ACL_XATTR_DEFAULT;
98 : break;
99 : default:
100 : return -EINVAL;
101 : }
102 :
103 14 : if (acl) {
104 0 : size = posix_acl_xattr_size(acl->a_count);
105 0 : value = kmalloc(size, GFP_NOFS);
106 0 : if (!value) {
107 : ret = -ENOMEM;
108 : goto out;
109 : }
110 :
111 0 : ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
112 0 : if (ret < 0)
113 : goto out;
114 : }
115 :
116 14 : ret = __btrfs_setxattr(trans, inode, name, value, size, 0);
117 : out:
118 14 : kfree(value);
119 :
120 14 : if (!ret)
121 14 : set_cached_acl(inode, type, acl);
122 :
123 14 : return ret;
124 : }
125 :
126 14 : int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
127 : {
128 14 : return __btrfs_set_acl(NULL, inode, acl, type);
129 : }
130 :
131 : /*
132 : * btrfs_init_acl is already generally called under fs_mutex, so the locking
133 : * stuff has been fixed to work with that. If the locking stuff changes, we
134 : * need to re-evaluate the acl locking stuff.
135 : */
136 20423 : int btrfs_init_acl(struct btrfs_trans_handle *trans,
137 : struct inode *inode, struct inode *dir)
138 : {
139 : struct posix_acl *default_acl, *acl;
140 : int ret = 0;
141 :
142 : /* this happens with subvols */
143 20423 : if (!dir)
144 : return 0;
145 :
146 20423 : ret = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
147 20423 : if (ret)
148 : return ret;
149 :
150 20423 : if (default_acl) {
151 0 : ret = __btrfs_set_acl(trans, inode, default_acl,
152 : ACL_TYPE_DEFAULT);
153 0 : posix_acl_release(default_acl);
154 : }
155 :
156 20423 : if (acl) {
157 0 : if (!ret)
158 0 : ret = __btrfs_set_acl(trans, inode, acl,
159 : ACL_TYPE_ACCESS);
160 0 : posix_acl_release(acl);
161 : }
162 :
163 20423 : if (!default_acl && !acl)
164 : cache_no_acl(inode);
165 20423 : return ret;
166 : }
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