2 * Copyright (C) 2007 Red Hat. All rights reserved.
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.
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.
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.
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>
28 #include "btrfs_inode.h"
31 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
33 static struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
38 struct posix_acl *acl;
40 acl = get_cached_acl(inode, type);
41 if (acl != ACL_NOT_CACHED)
46 name = POSIX_ACL_XATTR_ACCESS;
48 case ACL_TYPE_DEFAULT:
49 name = POSIX_ACL_XATTR_DEFAULT;
55 size = __btrfs_getxattr(inode, name, "", 0);
57 value = kzalloc(size, GFP_NOFS);
59 return ERR_PTR(-ENOMEM);
60 size = __btrfs_getxattr(inode, name, value, size);
62 acl = posix_acl_from_xattr(value, size);
67 set_cached_acl(inode, type, acl);
70 } else if (size == -ENOENT || size == -ENODATA || size == 0) {
71 /* FIXME, who returns -ENOENT? I think nobody */
73 set_cached_acl(inode, type, acl);
81 static int btrfs_xattr_acl_get(struct dentry *dentry, const char *name,
82 void *value, size_t size, int type)
84 struct posix_acl *acl;
87 acl = btrfs_get_acl(dentry->d_inode, type);
93 ret = posix_acl_to_xattr(acl, value, size);
94 posix_acl_release(acl);
100 * Needs to be called with fs_mutex held
102 static int btrfs_set_acl(struct btrfs_trans_handle *trans,
103 struct inode *inode, struct posix_acl *acl, int type)
111 ret = posix_acl_valid(acl);
118 case ACL_TYPE_ACCESS:
119 mode = inode->i_mode;
120 name = POSIX_ACL_XATTR_ACCESS;
122 ret = posix_acl_equiv_mode(acl, &mode);
125 inode->i_mode = mode;
129 case ACL_TYPE_DEFAULT:
130 if (!S_ISDIR(inode->i_mode))
131 return acl ? -EINVAL : 0;
132 name = POSIX_ACL_XATTR_DEFAULT;
139 size = posix_acl_xattr_size(acl->a_count);
140 value = kmalloc(size, GFP_NOFS);
146 ret = posix_acl_to_xattr(acl, value, size);
151 ret = __btrfs_setxattr(trans, inode, name, value, size, 0);
156 set_cached_acl(inode, type, acl);
161 static int btrfs_xattr_acl_set(struct dentry *dentry, const char *name,
162 const void *value, size_t size, int flags, int type)
165 struct posix_acl *acl = NULL;
167 if (!is_owner_or_cap(dentry->d_inode))
170 if (!IS_POSIXACL(dentry->d_inode))
174 acl = posix_acl_from_xattr(value, size);
178 } else if (IS_ERR(acl)) {
183 ret = btrfs_set_acl(NULL, dentry->d_inode, acl, type);
185 posix_acl_release(acl);
190 int btrfs_check_acl(struct inode *inode, int mask, unsigned int flags)
194 if (flags & IPERM_FLAG_RCU) {
195 if (!negative_cached_acl(inode, ACL_TYPE_ACCESS))
199 struct posix_acl *acl;
200 acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
204 error = posix_acl_permission(inode, acl, mask);
205 posix_acl_release(acl);
213 * btrfs_init_acl is already generally called under fs_mutex, so the locking
214 * stuff has been fixed to work with that. If the locking stuff changes, we
215 * need to re-evaluate the acl locking stuff.
217 int btrfs_init_acl(struct btrfs_trans_handle *trans,
218 struct inode *inode, struct inode *dir)
220 struct posix_acl *acl = NULL;
223 /* this happens with subvols */
227 if (!S_ISLNK(inode->i_mode)) {
228 if (IS_POSIXACL(dir)) {
229 acl = btrfs_get_acl(dir, ACL_TYPE_DEFAULT);
235 inode->i_mode &= ~current_umask();
238 if (IS_POSIXACL(dir) && acl) {
239 struct posix_acl *clone;
242 if (S_ISDIR(inode->i_mode)) {
243 ret = btrfs_set_acl(trans, inode, acl,
248 clone = posix_acl_clone(acl, GFP_NOFS);
253 mode = inode->i_mode;
254 ret = posix_acl_create_masq(clone, &mode);
256 inode->i_mode = mode;
259 ret = btrfs_set_acl(trans, inode, clone,
263 posix_acl_release(clone);
266 posix_acl_release(acl);
271 int btrfs_acl_chmod(struct inode *inode)
273 struct posix_acl *acl, *clone;
276 if (S_ISLNK(inode->i_mode))
279 if (!IS_POSIXACL(inode))
282 acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
283 if (IS_ERR(acl) || !acl)
286 clone = posix_acl_clone(acl, GFP_KERNEL);
287 posix_acl_release(acl);
291 ret = posix_acl_chmod_masq(clone, inode->i_mode);
293 ret = btrfs_set_acl(NULL, inode, clone, ACL_TYPE_ACCESS);
295 posix_acl_release(clone);
300 const struct xattr_handler btrfs_xattr_acl_default_handler = {
301 .prefix = POSIX_ACL_XATTR_DEFAULT,
302 .flags = ACL_TYPE_DEFAULT,
303 .get = btrfs_xattr_acl_get,
304 .set = btrfs_xattr_acl_set,
307 const struct xattr_handler btrfs_xattr_acl_access_handler = {
308 .prefix = POSIX_ACL_XATTR_ACCESS,
309 .flags = ACL_TYPE_ACCESS,
310 .get = btrfs_xattr_acl_get,
311 .set = btrfs_xattr_acl_set,
314 #else /* CONFIG_BTRFS_FS_POSIX_ACL */
316 int btrfs_acl_chmod(struct inode *inode)
321 int btrfs_init_acl(struct btrfs_trans_handle *trans,
322 struct inode *inode, struct inode *dir)
327 #endif /* CONFIG_BTRFS_FS_POSIX_ACL */