2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License version 2.
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13 #include <linux/completion.h>
14 #include <linux/buffer_head.h>
15 #include <linux/xattr.h>
16 #include <linux/posix_acl.h>
17 #include <linux/posix_acl_xattr.h>
18 #include <linux/gfs2_ondisk.h>
30 static const char *gfs2_acl_name(int type)
34 return GFS2_POSIX_ACL_ACCESS;
35 case ACL_TYPE_DEFAULT:
36 return GFS2_POSIX_ACL_DEFAULT;
41 static struct posix_acl *gfs2_acl_get(struct gfs2_inode *ip, int type)
43 struct posix_acl *acl;
51 acl = get_cached_acl(&ip->i_inode, type);
52 if (acl != ACL_NOT_CACHED)
55 name = gfs2_acl_name(type);
57 return ERR_PTR(-EINVAL);
59 len = gfs2_xattr_acl_get(ip, name, &data);
65 acl = posix_acl_from_xattr(data, len);
71 * gfs2_check_acl - Check an ACL to see if we're allowed to do something
72 * @inode: the file we want to do something to
73 * @mask: what we want to do
78 int gfs2_check_acl(struct inode *inode, int mask, unsigned int flags)
80 struct posix_acl *acl;
83 if (flags & IPERM_FLAG_RCU)
86 acl = gfs2_acl_get(GFS2_I(inode), ACL_TYPE_ACCESS);
91 error = posix_acl_permission(inode, acl, mask);
92 posix_acl_release(acl);
99 static int gfs2_set_mode(struct inode *inode, mode_t mode)
103 if (mode != inode->i_mode) {
106 iattr.ia_valid = ATTR_MODE;
107 iattr.ia_mode = mode;
109 error = gfs2_setattr_simple(GFS2_I(inode), &iattr);
115 static int gfs2_acl_set(struct inode *inode, int type, struct posix_acl *acl)
120 const char *name = gfs2_acl_name(type);
122 BUG_ON(name == NULL);
123 len = posix_acl_to_xattr(acl, NULL, 0);
126 data = kmalloc(len, GFP_NOFS);
129 error = posix_acl_to_xattr(acl, data, len);
132 error = __gfs2_xattr_set(inode, name, data, len, 0, GFS2_EATYPE_SYS);
134 set_cached_acl(inode, type, acl);
140 int gfs2_acl_create(struct gfs2_inode *dip, struct inode *inode)
142 struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
143 struct posix_acl *acl, *clone;
144 mode_t mode = inode->i_mode;
147 if (!sdp->sd_args.ar_posix_acl)
149 if (S_ISLNK(inode->i_mode))
152 acl = gfs2_acl_get(dip, ACL_TYPE_DEFAULT);
156 mode &= ~current_umask();
157 if (mode != inode->i_mode)
158 error = gfs2_set_mode(inode, mode);
162 if (S_ISDIR(inode->i_mode)) {
163 error = gfs2_acl_set(inode, ACL_TYPE_DEFAULT, acl);
168 clone = posix_acl_clone(acl, GFP_NOFS);
172 posix_acl_release(acl);
175 error = posix_acl_create_masq(acl, &mode);
181 error = gfs2_acl_set(inode, ACL_TYPE_ACCESS, acl);
185 error = gfs2_set_mode(inode, mode);
187 posix_acl_release(acl);
191 int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr)
193 struct posix_acl *acl, *clone;
198 acl = gfs2_acl_get(ip, ACL_TYPE_ACCESS);
202 return gfs2_setattr_simple(ip, attr);
204 clone = posix_acl_clone(acl, GFP_NOFS);
208 posix_acl_release(acl);
211 error = posix_acl_chmod_masq(acl, attr->ia_mode);
213 len = posix_acl_to_xattr(acl, NULL, 0);
214 data = kmalloc(len, GFP_NOFS);
218 posix_acl_to_xattr(acl, data, len);
219 error = gfs2_xattr_acl_chmod(ip, attr, data);
221 set_cached_acl(&ip->i_inode, ACL_TYPE_ACCESS, acl);
225 posix_acl_release(acl);
229 static int gfs2_acl_type(const char *name)
231 if (strcmp(name, GFS2_POSIX_ACL_ACCESS) == 0)
232 return ACL_TYPE_ACCESS;
233 if (strcmp(name, GFS2_POSIX_ACL_DEFAULT) == 0)
234 return ACL_TYPE_DEFAULT;
238 static int gfs2_xattr_system_get(struct dentry *dentry, const char *name,
239 void *buffer, size_t size, int xtype)
241 struct inode *inode = dentry->d_inode;
242 struct gfs2_sbd *sdp = GFS2_SB(inode);
243 struct posix_acl *acl;
247 if (!sdp->sd_args.ar_posix_acl)
250 type = gfs2_acl_type(name);
254 acl = gfs2_acl_get(GFS2_I(inode), type);
260 error = posix_acl_to_xattr(acl, buffer, size);
261 posix_acl_release(acl);
266 static int gfs2_xattr_system_set(struct dentry *dentry, const char *name,
267 const void *value, size_t size, int flags,
270 struct inode *inode = dentry->d_inode;
271 struct gfs2_sbd *sdp = GFS2_SB(inode);
272 struct posix_acl *acl = NULL;
275 if (!sdp->sd_args.ar_posix_acl)
278 type = gfs2_acl_type(name);
281 if (flags & XATTR_CREATE)
283 if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
284 return value ? -EACCES : 0;
285 if ((current_fsuid() != inode->i_uid) && !capable(CAP_FOWNER))
287 if (S_ISLNK(inode->i_mode))
293 acl = posix_acl_from_xattr(value, size);
296 * acl_set_file(3) may request that we set default ACLs with
297 * zero length -- defend (gracefully) against that here.
302 error = PTR_ERR(acl);
306 error = posix_acl_valid(acl);
311 if (acl->a_count > GFS2_ACL_MAX_ENTRIES)
314 if (type == ACL_TYPE_ACCESS) {
315 mode_t mode = inode->i_mode;
316 error = posix_acl_equiv_mode(acl, &mode);
319 posix_acl_release(acl);
326 error = gfs2_set_mode(inode, mode);
332 error = __gfs2_xattr_set(inode, name, value, size, 0, GFS2_EATYPE_SYS);
335 set_cached_acl(inode, type, acl);
337 forget_cached_acl(inode, type);
340 posix_acl_release(acl);
345 const struct xattr_handler gfs2_xattr_system_handler = {
346 .prefix = XATTR_SYSTEM_PREFIX,
347 .flags = GFS2_EATYPE_SYS,
348 .get = gfs2_xattr_system_get,
349 .set = gfs2_xattr_system_set,