blob: 603972576f0f3b8e704dc8cf8061bc3bfccae51a [file] [log] [blame]
Josef Bacik5103e942007-11-16 11:45:54 -05001/*
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>
Josef Bacik33268ea2008-07-24 12:16:36 -040023#include <linux/posix_acl.h>
Chris Masonc1e32da2008-01-22 12:46:56 -050024#include <linux/sched.h>
Josef Bacik33268ea2008-07-24 12:16:36 -040025
Josef Bacik5103e942007-11-16 11:45:54 -050026#include "ctree.h"
Josef Bacik33268ea2008-07-24 12:16:36 -040027#include "btrfs_inode.h"
Josef Bacik5103e942007-11-16 11:45:54 -050028#include "xattr.h"
Josef Bacik33268ea2008-07-24 12:16:36 -040029
Josef Bacikeab922e2008-08-28 06:21:15 -040030#ifdef CONFIG_FS_POSIX_ACL
31
Josef Bacik33268ea2008-07-24 12:16:36 -040032static void btrfs_update_cached_acl(struct inode *inode,
33 struct posix_acl **p_acl,
34 struct posix_acl *acl)
35{
36 spin_lock(&inode->i_lock);
37 if (*p_acl && *p_acl != BTRFS_ACL_NOT_CACHED)
38 posix_acl_release(*p_acl);
39 *p_acl = posix_acl_dup(acl);
40 spin_unlock(&inode->i_lock);
41}
42
43static struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
44{
Christoph Hellwig95819c02008-08-28 06:21:17 -040045 int size;
46 const char *name;
Josef Bacik33268ea2008-07-24 12:16:36 -040047 char *value = NULL;
48 struct posix_acl *acl = NULL, **p_acl;
49
50 switch (type) {
51 case ACL_TYPE_ACCESS:
Christoph Hellwig95819c02008-08-28 06:21:17 -040052 name = POSIX_ACL_XATTR_ACCESS;
Josef Bacik33268ea2008-07-24 12:16:36 -040053 p_acl = &BTRFS_I(inode)->i_acl;
54 break;
55 case ACL_TYPE_DEFAULT:
Christoph Hellwig95819c02008-08-28 06:21:17 -040056 name = POSIX_ACL_XATTR_DEFAULT;
Josef Bacik33268ea2008-07-24 12:16:36 -040057 p_acl = &BTRFS_I(inode)->i_default_acl;
58 break;
59 default:
60 return ERR_PTR(-EINVAL);
61 }
62
Chris Mason7b1a14b2009-04-27 10:49:53 -040063 /* Handle the cached NULL acl case without locking */
64 acl = ACCESS_ONCE(*p_acl);
65 if (!acl)
Josef Bacik33268ea2008-07-24 12:16:36 -040066 return acl;
67
Chris Mason7b1a14b2009-04-27 10:49:53 -040068 spin_lock(&inode->i_lock);
69 acl = *p_acl;
70 if (acl != BTRFS_ACL_NOT_CACHED)
71 acl = posix_acl_dup(acl);
72 spin_unlock(&inode->i_lock);
73
74 if (acl != BTRFS_ACL_NOT_CACHED)
75 return acl;
Josef Bacik33268ea2008-07-24 12:16:36 -040076
Christoph Hellwig95819c02008-08-28 06:21:17 -040077 size = __btrfs_getxattr(inode, name, "", 0);
Josef Bacik33268ea2008-07-24 12:16:36 -040078 if (size > 0) {
79 value = kzalloc(size, GFP_NOFS);
80 if (!value)
81 return ERR_PTR(-ENOMEM);
Christoph Hellwig95819c02008-08-28 06:21:17 -040082 size = __btrfs_getxattr(inode, name, value, size);
Josef Bacik33268ea2008-07-24 12:16:36 -040083 if (size > 0) {
84 acl = posix_acl_from_xattr(value, size);
85 btrfs_update_cached_acl(inode, p_acl, acl);
86 }
87 kfree(value);
Chris Mason7b1a14b2009-04-27 10:49:53 -040088 } else if (size == -ENOENT || size == -ENODATA || size == 0) {
89 /* FIXME, who returns -ENOENT? I think nobody */
Josef Bacik33268ea2008-07-24 12:16:36 -040090 acl = NULL;
91 btrfs_update_cached_acl(inode, p_acl, acl);
Chris Mason7b1a14b2009-04-27 10:49:53 -040092 } else {
93 acl = ERR_PTR(-EIO);
Josef Bacik33268ea2008-07-24 12:16:36 -040094 }
95
96 return acl;
97}
98
99static int btrfs_xattr_get_acl(struct inode *inode, int type,
100 void *value, size_t size)
101{
102 struct posix_acl *acl;
103 int ret = 0;
104
105 acl = btrfs_get_acl(inode, type);
106
107 if (IS_ERR(acl))
108 return PTR_ERR(acl);
109 if (acl == NULL)
110 return -ENODATA;
111 ret = posix_acl_to_xattr(acl, value, size);
112 posix_acl_release(acl);
113
114 return ret;
115}
116
117/*
118 * Needs to be called with fs_mutex held
119 */
120static int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
121{
Christoph Hellwig95819c02008-08-28 06:21:17 -0400122 int ret, size = 0;
123 const char *name;
Josef Bacik33268ea2008-07-24 12:16:36 -0400124 struct posix_acl **p_acl;
125 char *value = NULL;
126 mode_t mode;
127
128 if (acl) {
129 ret = posix_acl_valid(acl);
130 if (ret < 0)
131 return ret;
132 ret = 0;
133 }
134
135 switch (type) {
136 case ACL_TYPE_ACCESS:
137 mode = inode->i_mode;
138 ret = posix_acl_equiv_mode(acl, &mode);
139 if (ret < 0)
140 return ret;
141 ret = 0;
142 inode->i_mode = mode;
Christoph Hellwig95819c02008-08-28 06:21:17 -0400143 name = POSIX_ACL_XATTR_ACCESS;
Josef Bacik33268ea2008-07-24 12:16:36 -0400144 p_acl = &BTRFS_I(inode)->i_acl;
145 break;
146 case ACL_TYPE_DEFAULT:
147 if (!S_ISDIR(inode->i_mode))
148 return acl ? -EINVAL : 0;
Christoph Hellwig95819c02008-08-28 06:21:17 -0400149 name = POSIX_ACL_XATTR_DEFAULT;
Josef Bacik33268ea2008-07-24 12:16:36 -0400150 p_acl = &BTRFS_I(inode)->i_default_acl;
151 break;
152 default:
153 return -EINVAL;
154 }
155
156 if (acl) {
157 size = posix_acl_xattr_size(acl->a_count);
158 value = kmalloc(size, GFP_NOFS);
159 if (!value) {
160 ret = -ENOMEM;
161 goto out;
162 }
163
164 ret = posix_acl_to_xattr(acl, value, size);
165 if (ret < 0)
166 goto out;
167 }
168
Christoph Hellwig95819c02008-08-28 06:21:17 -0400169 ret = __btrfs_setxattr(inode, name, value, size, 0);
Josef Bacik33268ea2008-07-24 12:16:36 -0400170
171out:
Chris Masond3977122009-01-05 21:25:51 -0500172 kfree(value);
Josef Bacik33268ea2008-07-24 12:16:36 -0400173
174 if (!ret)
175 btrfs_update_cached_acl(inode, p_acl, acl);
176
177 return ret;
178}
Yanfb4bc1e2008-01-17 11:59:51 -0500179
Yan744f52f2008-01-14 13:26:08 -0500180static int btrfs_xattr_set_acl(struct inode *inode, int type,
181 const void *value, size_t size)
182{
183 int ret = 0;
Josef Bacik33268ea2008-07-24 12:16:36 -0400184 struct posix_acl *acl = NULL;
Josef Bacik5103e942007-11-16 11:45:54 -0500185
Yan744f52f2008-01-14 13:26:08 -0500186 if (value) {
187 acl = posix_acl_from_xattr(value, size);
188 if (acl == NULL) {
189 value = NULL;
190 size = 0;
191 } else if (IS_ERR(acl)) {
Josef Bacik33268ea2008-07-24 12:16:36 -0400192 return PTR_ERR(acl);
Yan744f52f2008-01-14 13:26:08 -0500193 }
Yan744f52f2008-01-14 13:26:08 -0500194 }
Josef Bacik33268ea2008-07-24 12:16:36 -0400195
196 ret = btrfs_set_acl(inode, acl, type);
197
198 posix_acl_release(acl);
199
200 return ret;
Yan744f52f2008-01-14 13:26:08 -0500201}
Josef Bacik1caf9342007-11-19 10:18:17 -0500202
Josef Bacik33268ea2008-07-24 12:16:36 -0400203
Josef Bacik5103e942007-11-16 11:45:54 -0500204static int btrfs_xattr_acl_access_get(struct inode *inode, const char *name,
205 void *value, size_t size)
206{
Josef Bacik33268ea2008-07-24 12:16:36 -0400207 return btrfs_xattr_get_acl(inode, ACL_TYPE_ACCESS, value, size);
Josef Bacik5103e942007-11-16 11:45:54 -0500208}
Josef Bacik33268ea2008-07-24 12:16:36 -0400209
Josef Bacik5103e942007-11-16 11:45:54 -0500210static int btrfs_xattr_acl_access_set(struct inode *inode, const char *name,
211 const void *value, size_t size, int flags)
212{
Josef Bacik33268ea2008-07-24 12:16:36 -0400213 return btrfs_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
Josef Bacik5103e942007-11-16 11:45:54 -0500214}
Josef Bacik33268ea2008-07-24 12:16:36 -0400215
Josef Bacik5103e942007-11-16 11:45:54 -0500216static int btrfs_xattr_acl_default_get(struct inode *inode, const char *name,
217 void *value, size_t size)
218{
Josef Bacik33268ea2008-07-24 12:16:36 -0400219 return btrfs_xattr_get_acl(inode, ACL_TYPE_DEFAULT, value, size);
Josef Bacik5103e942007-11-16 11:45:54 -0500220}
Josef Bacik33268ea2008-07-24 12:16:36 -0400221
Josef Bacik5103e942007-11-16 11:45:54 -0500222static int btrfs_xattr_acl_default_set(struct inode *inode, const char *name,
Chris Masond3977122009-01-05 21:25:51 -0500223 const void *value, size_t size, int flags)
Josef Bacik5103e942007-11-16 11:45:54 -0500224{
Josef Bacik33268ea2008-07-24 12:16:36 -0400225 return btrfs_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
Josef Bacik5103e942007-11-16 11:45:54 -0500226}
Josef Bacik33268ea2008-07-24 12:16:36 -0400227
228int btrfs_check_acl(struct inode *inode, int mask)
229{
230 struct posix_acl *acl;
231 int error = -EAGAIN;
232
233 acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
234
235 if (IS_ERR(acl))
236 return PTR_ERR(acl);
237 if (acl) {
238 error = posix_acl_permission(inode, acl, mask);
239 posix_acl_release(acl);
240 }
241
242 return error;
243}
244
245/*
246 * btrfs_init_acl is already generally called under fs_mutex, so the locking
247 * stuff has been fixed to work with that. If the locking stuff changes, we
248 * need to re-evaluate the acl locking stuff.
249 */
250int btrfs_init_acl(struct inode *inode, struct inode *dir)
251{
252 struct posix_acl *acl = NULL;
253 int ret = 0;
254
255 /* this happens with subvols */
256 if (!dir)
257 return 0;
258
259 if (!S_ISLNK(inode->i_mode)) {
260 if (IS_POSIXACL(dir)) {
261 acl = btrfs_get_acl(dir, ACL_TYPE_DEFAULT);
262 if (IS_ERR(acl))
263 return PTR_ERR(acl);
264 }
265
266 if (!acl)
Al Viroce3b0f82009-03-29 19:08:22 -0400267 inode->i_mode &= ~current_umask();
Josef Bacik33268ea2008-07-24 12:16:36 -0400268 }
269
270 if (IS_POSIXACL(dir) && acl) {
271 struct posix_acl *clone;
272 mode_t mode;
273
274 if (S_ISDIR(inode->i_mode)) {
275 ret = btrfs_set_acl(inode, acl, ACL_TYPE_DEFAULT);
276 if (ret)
277 goto failed;
278 }
279 clone = posix_acl_clone(acl, GFP_NOFS);
280 ret = -ENOMEM;
281 if (!clone)
282 goto failed;
283
284 mode = inode->i_mode;
285 ret = posix_acl_create_masq(clone, &mode);
286 if (ret >= 0) {
287 inode->i_mode = mode;
288 if (ret > 0) {
289 /* we need an acl */
290 ret = btrfs_set_acl(inode, clone,
291 ACL_TYPE_ACCESS);
292 }
293 }
294 }
295failed:
296 posix_acl_release(acl);
297
298 return ret;
299}
300
301int btrfs_acl_chmod(struct inode *inode)
302{
303 struct posix_acl *acl, *clone;
304 int ret = 0;
305
306 if (S_ISLNK(inode->i_mode))
307 return -EOPNOTSUPP;
308
309 if (!IS_POSIXACL(inode))
310 return 0;
311
312 acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
313 if (IS_ERR(acl) || !acl)
314 return PTR_ERR(acl);
315
316 clone = posix_acl_clone(acl, GFP_KERNEL);
317 posix_acl_release(acl);
318 if (!clone)
319 return -ENOMEM;
320
321 ret = posix_acl_chmod_masq(clone, inode->i_mode);
322 if (!ret)
323 ret = btrfs_set_acl(inode, clone, ACL_TYPE_ACCESS);
324
325 posix_acl_release(clone);
326
327 return ret;
328}
329
Josef Bacik5103e942007-11-16 11:45:54 -0500330struct xattr_handler btrfs_xattr_acl_default_handler = {
331 .prefix = POSIX_ACL_XATTR_DEFAULT,
Josef Bacik5103e942007-11-16 11:45:54 -0500332 .get = btrfs_xattr_acl_default_get,
333 .set = btrfs_xattr_acl_default_set,
334};
335
336struct xattr_handler btrfs_xattr_acl_access_handler = {
337 .prefix = POSIX_ACL_XATTR_ACCESS,
Josef Bacik5103e942007-11-16 11:45:54 -0500338 .get = btrfs_xattr_acl_access_get,
339 .set = btrfs_xattr_acl_access_set,
340};
Josef Bacikeab922e2008-08-28 06:21:15 -0400341
342#else /* CONFIG_FS_POSIX_ACL */
343
344int btrfs_acl_chmod(struct inode *inode)
345{
346 return 0;
347}
348
349int btrfs_init_acl(struct inode *inode, struct inode *dir)
350{
351 return 0;
352}
353
Josef Bacikeab922e2008-08-28 06:21:15 -0400354#endif /* CONFIG_FS_POSIX_ACL */