2 * Copyright IBM Corporation, 2010
3 * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of version 2.1 of the GNU Lesser General Public License
7 * as published by the Free Software Foundation.
9 * This program is distributed in the hope that it would be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
15 #include <linux/module.h>
17 #include <net/9p/9p.h>
18 #include <net/9p/client.h>
19 #include <linux/slab.h>
20 #include <linux/sched.h>
21 #include <linux/posix_acl_xattr.h>
27 static struct posix_acl *__v9fs_get_acl(struct p9_fid *fid, char *name)
31 struct posix_acl *acl = NULL;
33 size = v9fs_fid_xattr_get(fid, name, NULL, 0);
35 value = kzalloc(size, GFP_NOFS);
37 return ERR_PTR(-ENOMEM);
38 size = v9fs_fid_xattr_get(fid, name, value, size);
40 acl = posix_acl_from_xattr(value, size);
44 } else if (size == -ENODATA || size == 0 ||
45 size == -ENOSYS || size == -EOPNOTSUPP) {
55 int v9fs_get_acl(struct inode *inode, struct p9_fid *fid)
58 struct posix_acl *pacl, *dacl;
59 struct v9fs_session_info *v9ses;
61 v9ses = v9fs_inode2v9ses(inode);
62 if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) ||
63 ((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) {
64 set_cached_acl(inode, ACL_TYPE_DEFAULT, NULL);
65 set_cached_acl(inode, ACL_TYPE_ACCESS, NULL);
68 /* get the default/access acl values and cache them */
69 dacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_DEFAULT);
70 pacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_ACCESS);
72 if (!IS_ERR(dacl) && !IS_ERR(pacl)) {
73 set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl);
74 set_cached_acl(inode, ACL_TYPE_ACCESS, pacl);
79 posix_acl_release(dacl);
82 posix_acl_release(pacl);
87 static struct posix_acl *v9fs_get_cached_acl(struct inode *inode, int type)
89 struct posix_acl *acl;
91 * 9p Always cache the acl value when
92 * instantiating the inode (v9fs_inode_from_fid)
94 acl = get_cached_acl(inode, type);
95 BUG_ON(acl == ACL_NOT_CACHED);
99 int v9fs_check_acl(struct inode *inode, int mask)
101 struct posix_acl *acl;
102 struct v9fs_session_info *v9ses;
104 v9ses = v9fs_inode2v9ses(inode);
105 if (((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) ||
106 ((v9ses->flags & V9FS_ACL_MASK) != V9FS_POSIX_ACL)) {
108 * On access = client and acl = on mode get the acl
109 * values from the server
113 acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS);
118 int error = posix_acl_permission(inode, acl, mask);
119 posix_acl_release(acl);
125 static int v9fs_set_acl(struct dentry *dentry, int type, struct posix_acl *acl)
131 struct inode *inode = dentry->d_inode;
133 set_cached_acl(inode, type, acl);
138 /* Set a setxattr request to server */
139 size = posix_acl_xattr_size(acl->a_count);
140 buffer = kmalloc(size, GFP_KERNEL);
143 retval = posix_acl_to_xattr(acl, buffer, size);
147 case ACL_TYPE_ACCESS:
148 name = POSIX_ACL_XATTR_ACCESS;
150 case ACL_TYPE_DEFAULT:
151 name = POSIX_ACL_XATTR_DEFAULT;
156 retval = v9fs_xattr_set(dentry, name, buffer, size, 0);
162 int v9fs_acl_chmod(struct dentry *dentry)
165 struct posix_acl *acl;
166 struct inode *inode = dentry->d_inode;
168 if (S_ISLNK(inode->i_mode))
170 acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS);
172 retval = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
175 retval = v9fs_set_acl(dentry, ACL_TYPE_ACCESS, acl);
176 posix_acl_release(acl);
181 int v9fs_set_create_acl(struct dentry *dentry,
182 struct posix_acl **dpacl, struct posix_acl **pacl)
185 v9fs_set_acl(dentry, ACL_TYPE_DEFAULT, *dpacl);
186 v9fs_set_acl(dentry, ACL_TYPE_ACCESS, *pacl);
188 posix_acl_release(*dpacl);
189 posix_acl_release(*pacl);
190 *dpacl = *pacl = NULL;
194 int v9fs_acl_mode(struct inode *dir, mode_t *modep,
195 struct posix_acl **dpacl, struct posix_acl **pacl)
198 mode_t mode = *modep;
199 struct posix_acl *acl = NULL;
201 if (!S_ISLNK(mode)) {
202 acl = v9fs_get_cached_acl(dir, ACL_TYPE_DEFAULT);
206 mode &= ~current_umask();
210 *dpacl = posix_acl_dup(acl);
211 retval = posix_acl_create(&acl, GFP_NOFS, &mode);
217 posix_acl_release(acl);
223 static int v9fs_remote_get_acl(struct dentry *dentry, const char *name,
224 void *buffer, size_t size, int type)
229 case ACL_TYPE_ACCESS:
230 full_name = POSIX_ACL_XATTR_ACCESS;
232 case ACL_TYPE_DEFAULT:
233 full_name = POSIX_ACL_XATTR_DEFAULT;
238 return v9fs_xattr_get(dentry, full_name, buffer, size);
241 static int v9fs_xattr_get_acl(struct dentry *dentry, const char *name,
242 void *buffer, size_t size, int type)
244 struct v9fs_session_info *v9ses;
245 struct posix_acl *acl;
248 if (strcmp(name, "") != 0)
251 v9ses = v9fs_dentry2v9ses(dentry);
253 * We allow set/get/list of acl when access=client is not specified
255 if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
256 return v9fs_remote_get_acl(dentry, name, buffer, size, type);
258 acl = v9fs_get_cached_acl(dentry->d_inode, type);
263 error = posix_acl_to_xattr(acl, buffer, size);
264 posix_acl_release(acl);
269 static int v9fs_remote_set_acl(struct dentry *dentry, const char *name,
270 const void *value, size_t size,
276 case ACL_TYPE_ACCESS:
277 full_name = POSIX_ACL_XATTR_ACCESS;
279 case ACL_TYPE_DEFAULT:
280 full_name = POSIX_ACL_XATTR_DEFAULT;
285 return v9fs_xattr_set(dentry, full_name, value, size, flags);
289 static int v9fs_xattr_set_acl(struct dentry *dentry, const char *name,
290 const void *value, size_t size,
294 struct posix_acl *acl;
295 struct v9fs_session_info *v9ses;
296 struct inode *inode = dentry->d_inode;
298 if (strcmp(name, "") != 0)
301 v9ses = v9fs_dentry2v9ses(dentry);
303 * set the attribute on the remote. Without even looking at the
304 * xattr value. We leave it to the server to validate
306 if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
307 return v9fs_remote_set_acl(dentry, name,
308 value, size, flags, type);
310 if (S_ISLNK(inode->i_mode))
312 if (!inode_owner_or_capable(inode))
315 /* update the cached acl value */
316 acl = posix_acl_from_xattr(value, size);
320 retval = posix_acl_valid(acl);
328 case ACL_TYPE_ACCESS:
329 name = POSIX_ACL_XATTR_ACCESS;
331 mode_t mode = inode->i_mode;
332 retval = posix_acl_equiv_mode(acl, &mode);
339 * ACL can be represented
340 * by the mode bits. So don't
347 /* Updte the mode bits */
348 iattr.ia_mode = ((mode & S_IALLUGO) |
349 (inode->i_mode & ~S_IALLUGO));
350 iattr.ia_valid = ATTR_MODE;
351 /* FIXME should we update ctime ?
352 * What is the following setxattr update the
355 v9fs_vfs_setattr_dotl(dentry, &iattr);
359 case ACL_TYPE_DEFAULT:
360 name = POSIX_ACL_XATTR_DEFAULT;
361 if (!S_ISDIR(inode->i_mode)) {
362 retval = acl ? -EINVAL : 0;
369 retval = v9fs_xattr_set(dentry, name, value, size, flags);
371 set_cached_acl(inode, type, acl);
373 posix_acl_release(acl);
377 const struct xattr_handler v9fs_xattr_acl_access_handler = {
378 .prefix = POSIX_ACL_XATTR_ACCESS,
379 .flags = ACL_TYPE_ACCESS,
380 .get = v9fs_xattr_get_acl,
381 .set = v9fs_xattr_set_acl,
384 const struct xattr_handler v9fs_xattr_acl_default_handler = {
385 .prefix = POSIX_ACL_XATTR_DEFAULT,
386 .flags = ACL_TYPE_DEFAULT,
387 .get = v9fs_xattr_get_acl,
388 .set = v9fs_xattr_set_acl,