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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
31struct 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 if (!IS_POSIXACL(inode))
39 return NULL;
40
41 acl = get_cached_acl(inode, type);
42 if (acl != ACL_NOT_CACHED)
43 return acl;
44
45 switch (type) {
46 case ACL_TYPE_ACCESS:
47 name = POSIX_ACL_XATTR_ACCESS;
48 break;
49 case ACL_TYPE_DEFAULT:
50 name = POSIX_ACL_XATTR_DEFAULT;
51 break;
52 default:
53 BUG();
54 }
55
56 size = __btrfs_getxattr(inode, name, "", 0);
57 if (size > 0) {
58 value = kzalloc(size, GFP_NOFS);
59 if (!value)
60 return ERR_PTR(-ENOMEM);
61 size = __btrfs_getxattr(inode, name, value, size);
62 }
63 if (size > 0) {
64 acl = posix_acl_from_xattr(value, size);
65 } else if (size == -ENOENT || size == -ENODATA || size == 0) {
66 /* FIXME, who returns -ENOENT? I think nobody */
67 acl = NULL;
68 } else {
69 acl = ERR_PTR(-EIO);
70 }
71 kfree(value);
72
73 if (!IS_ERR(acl))
74 set_cached_acl(inode, type, acl);
75
76 return acl;
77}
78
79static int btrfs_xattr_acl_get(struct dentry *dentry, const char *name,
80 void *value, size_t size, int type)
81{
82 struct posix_acl *acl;
83 int ret = 0;
84
85 if (!IS_POSIXACL(dentry->d_inode))
86 return -EOPNOTSUPP;
87
88 acl = btrfs_get_acl(dentry->d_inode, type);
89
90 if (IS_ERR(acl))
91 return PTR_ERR(acl);
92 if (acl == NULL)
93 return -ENODATA;
94 ret = posix_acl_to_xattr(acl, value, size);
95 posix_acl_release(acl);
96
97 return ret;
98}
99
100/*
101 * Needs to be called with fs_mutex held
102 */
103static int btrfs_set_acl(struct btrfs_trans_handle *trans,
104 struct inode *inode, struct posix_acl *acl, int type)
105{
106 int ret, size = 0;
107 const char *name;
108 char *value = NULL;
109
110 if (acl) {
111 ret = posix_acl_valid(acl);
112 if (ret < 0)
113 return ret;
114 ret = 0;
115 }
116
117 switch (type) {
118 case ACL_TYPE_ACCESS:
119 name = POSIX_ACL_XATTR_ACCESS;
120 if (acl) {
121 ret = posix_acl_equiv_mode(acl, &inode->i_mode);
122 if (ret < 0)
123 return ret;
124 }
125 ret = 0;
126 break;
127 case ACL_TYPE_DEFAULT:
128 if (!S_ISDIR(inode->i_mode))
129 return acl ? -EINVAL : 0;
130 name = POSIX_ACL_XATTR_DEFAULT;
131 break;
132 default:
133 return -EINVAL;
134 }
135
136 if (acl) {
137 size = posix_acl_xattr_size(acl->a_count);
138 value = kmalloc(size, GFP_NOFS);
139 if (!value) {
140 ret = -ENOMEM;
141 goto out;
142 }
143
144 ret = posix_acl_to_xattr(acl, value, size);
145 if (ret < 0)
146 goto out;
147 }
148
149 ret = __btrfs_setxattr(trans, inode, name, value, size, 0);
150out:
151 kfree(value);
152
153 if (!ret)
154 set_cached_acl(inode, type, acl);
155
156 return ret;
157}
158
159static int btrfs_xattr_acl_set(struct dentry *dentry, const char *name,
160 const void *value, size_t size, int flags, int type)
161{
162 int ret;
163 struct posix_acl *acl = NULL;
164
165 if (!inode_owner_or_capable(dentry->d_inode))
166 return -EPERM;
167
168 if (!IS_POSIXACL(dentry->d_inode))
169 return -EOPNOTSUPP;
170
171 if (value) {
172 acl = posix_acl_from_xattr(value, size);
173 if (IS_ERR(acl))
174 return PTR_ERR(acl);
175
176 if (acl) {
177 ret = posix_acl_valid(acl);
178 if (ret)
179 goto out;
180 }
181 }
182
183 ret = btrfs_set_acl(NULL, dentry->d_inode, acl, type);
184out:
185 posix_acl_release(acl);
186
187 return ret;
188}
189
190/*
191 * btrfs_init_acl is already generally called under fs_mutex, so the locking
192 * stuff has been fixed to work with that. If the locking stuff changes, we
193 * need to re-evaluate the acl locking stuff.
194 */
195int btrfs_init_acl(struct btrfs_trans_handle *trans,
196 struct inode *inode, struct inode *dir)
197{
198 struct posix_acl *acl = NULL;
199 int ret = 0;
200
201 /* this happens with subvols */
202 if (!dir)
203 return 0;
204
205 if (!S_ISLNK(inode->i_mode)) {
206 if (IS_POSIXACL(dir)) {
207 acl = btrfs_get_acl(dir, ACL_TYPE_DEFAULT);
208 if (IS_ERR(acl))
209 return PTR_ERR(acl);
210 }
211
212 if (!acl)
213 inode->i_mode &= ~current_umask();
214 }
215
216 if (IS_POSIXACL(dir) && acl) {
217 if (S_ISDIR(inode->i_mode)) {
218 ret = btrfs_set_acl(trans, inode, acl,
219 ACL_TYPE_DEFAULT);
220 if (ret)
221 goto failed;
222 }
223 ret = posix_acl_create(&acl, GFP_NOFS, &inode->i_mode);
224 if (ret < 0)
225 return ret;
226
227 if (ret > 0) {
228 /* we need an acl */
229 ret = btrfs_set_acl(trans, inode, acl, ACL_TYPE_ACCESS);
230 } else {
231 cache_no_acl(inode);
232 }
233 } else {
234 cache_no_acl(inode);
235 }
236failed:
237 posix_acl_release(acl);
238
239 return ret;
240}
241
242int btrfs_acl_chmod(struct inode *inode)
243{
244 struct posix_acl *acl;
245 int ret = 0;
246
247 if (S_ISLNK(inode->i_mode))
248 return -EOPNOTSUPP;
249
250 if (!IS_POSIXACL(inode))
251 return 0;
252
253 acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
254 if (IS_ERR_OR_NULL(acl))
255 return PTR_ERR(acl);
256
257 ret = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
258 if (ret)
259 return ret;
260 ret = btrfs_set_acl(NULL, inode, acl, ACL_TYPE_ACCESS);
261 posix_acl_release(acl);
262 return ret;
263}
264
265const struct xattr_handler btrfs_xattr_acl_default_handler = {
266 .prefix = POSIX_ACL_XATTR_DEFAULT,
267 .flags = ACL_TYPE_DEFAULT,
268 .get = btrfs_xattr_acl_get,
269 .set = btrfs_xattr_acl_set,
270};
271
272const struct xattr_handler btrfs_xattr_acl_access_handler = {
273 .prefix = POSIX_ACL_XATTR_ACCESS,
274 .flags = ACL_TYPE_ACCESS,
275 .get = btrfs_xattr_acl_get,
276 .set = btrfs_xattr_acl_set,
277};
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
31struct 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 switch (type) {
39 case ACL_TYPE_ACCESS:
40 name = XATTR_NAME_POSIX_ACL_ACCESS;
41 break;
42 case ACL_TYPE_DEFAULT:
43 name = XATTR_NAME_POSIX_ACL_DEFAULT;
44 break;
45 default:
46 BUG();
47 }
48
49 size = __btrfs_getxattr(inode, name, "", 0);
50 if (size > 0) {
51 value = kzalloc(size, GFP_KERNEL);
52 if (!value)
53 return ERR_PTR(-ENOMEM);
54 size = __btrfs_getxattr(inode, name, value, size);
55 }
56 if (size > 0) {
57 acl = posix_acl_from_xattr(&init_user_ns, value, size);
58 } else if (size == -ERANGE || size == -ENODATA || size == 0) {
59 acl = NULL;
60 } else {
61 acl = ERR_PTR(-EIO);
62 }
63 kfree(value);
64
65 return acl;
66}
67
68/*
69 * Needs to be called with fs_mutex held
70 */
71static int __btrfs_set_acl(struct btrfs_trans_handle *trans,
72 struct inode *inode, struct posix_acl *acl, int type)
73{
74 int ret, size = 0;
75 const char *name;
76 char *value = NULL;
77
78 switch (type) {
79 case ACL_TYPE_ACCESS:
80 name = XATTR_NAME_POSIX_ACL_ACCESS;
81 if (acl) {
82 ret = posix_acl_update_mode(inode, &inode->i_mode, &acl);
83 if (ret)
84 return ret;
85 }
86 ret = 0;
87 break;
88 case ACL_TYPE_DEFAULT:
89 if (!S_ISDIR(inode->i_mode))
90 return acl ? -EINVAL : 0;
91 name = XATTR_NAME_POSIX_ACL_DEFAULT;
92 break;
93 default:
94 return -EINVAL;
95 }
96
97 if (acl) {
98 size = posix_acl_xattr_size(acl->a_count);
99 value = kmalloc(size, GFP_KERNEL);
100 if (!value) {
101 ret = -ENOMEM;
102 goto out;
103 }
104
105 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
106 if (ret < 0)
107 goto out;
108 }
109
110 ret = __btrfs_setxattr(trans, inode, name, value, size, 0);
111out:
112 kfree(value);
113
114 if (!ret)
115 set_cached_acl(inode, type, acl);
116
117 return ret;
118}
119
120int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
121{
122 return __btrfs_set_acl(NULL, inode, acl, type);
123}
124
125/*
126 * btrfs_init_acl is already generally called under fs_mutex, so the locking
127 * stuff has been fixed to work with that. If the locking stuff changes, we
128 * need to re-evaluate the acl locking stuff.
129 */
130int btrfs_init_acl(struct btrfs_trans_handle *trans,
131 struct inode *inode, struct inode *dir)
132{
133 struct posix_acl *default_acl, *acl;
134 int ret = 0;
135
136 /* this happens with subvols */
137 if (!dir)
138 return 0;
139
140 ret = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
141 if (ret)
142 return ret;
143
144 if (default_acl) {
145 ret = __btrfs_set_acl(trans, inode, default_acl,
146 ACL_TYPE_DEFAULT);
147 posix_acl_release(default_acl);
148 }
149
150 if (acl) {
151 if (!ret)
152 ret = __btrfs_set_acl(trans, inode, acl,
153 ACL_TYPE_ACCESS);
154 posix_acl_release(acl);
155 }
156
157 if (!default_acl && !acl)
158 cache_no_acl(inode);
159 return ret;
160}