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  • only in /asuswrt-rt-n18u-9.0.0.4.380.2695/release/src-rt-6.x.4708/linux/linux-2.6.36/fs/jfs/
1/*
2 *   Copyright (C) International Business Machines  Corp., 2002-2004
3 *   Copyright (C) Andreas Gruenbacher, 2001
4 *   Copyright (C) Linus Torvalds, 1991, 1992
5 *
6 *   This program is free software;  you can redistribute it and/or modify
7 *   it under the terms of the GNU General Public License as published by
8 *   the Free Software Foundation; either version 2 of the License, or
9 *   (at your option) any later version.
10 *
11 *   This program is distributed in the hope that it will be useful,
12 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
13 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
14 *   the GNU General Public License for more details.
15 *
16 *   You should have received a copy of the GNU General Public License
17 *   along with this program;  if not, write to the Free Software
18 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21#include <linux/sched.h>
22#include <linux/slab.h>
23#include <linux/fs.h>
24#include <linux/posix_acl_xattr.h>
25#include "jfs_incore.h"
26#include "jfs_txnmgr.h"
27#include "jfs_xattr.h"
28#include "jfs_acl.h"
29
30static struct posix_acl *jfs_get_acl(struct inode *inode, int type)
31{
32	struct posix_acl *acl;
33	char *ea_name;
34	int size;
35	char *value = NULL;
36
37	acl = get_cached_acl(inode, type);
38	if (acl != ACL_NOT_CACHED)
39		return acl;
40
41	switch(type) {
42		case ACL_TYPE_ACCESS:
43			ea_name = POSIX_ACL_XATTR_ACCESS;
44			break;
45		case ACL_TYPE_DEFAULT:
46			ea_name = POSIX_ACL_XATTR_DEFAULT;
47			break;
48		default:
49			return ERR_PTR(-EINVAL);
50	}
51
52	size = __jfs_getxattr(inode, ea_name, NULL, 0);
53
54	if (size > 0) {
55		value = kmalloc(size, GFP_KERNEL);
56		if (!value)
57			return ERR_PTR(-ENOMEM);
58		size = __jfs_getxattr(inode, ea_name, value, size);
59	}
60
61	if (size < 0) {
62		if (size == -ENODATA)
63			acl = NULL;
64		else
65			acl = ERR_PTR(size);
66	} else {
67		acl = posix_acl_from_xattr(value, size);
68	}
69	kfree(value);
70	if (!IS_ERR(acl))
71		set_cached_acl(inode, type, acl);
72	return acl;
73}
74
75static int jfs_set_acl(tid_t tid, struct inode *inode, int type,
76		       struct posix_acl *acl)
77{
78	char *ea_name;
79	int rc;
80	int size = 0;
81	char *value = NULL;
82
83	if (S_ISLNK(inode->i_mode))
84		return -EOPNOTSUPP;
85
86	switch(type) {
87		case ACL_TYPE_ACCESS:
88			ea_name = POSIX_ACL_XATTR_ACCESS;
89			break;
90		case ACL_TYPE_DEFAULT:
91			ea_name = POSIX_ACL_XATTR_DEFAULT;
92			if (!S_ISDIR(inode->i_mode))
93				return acl ? -EACCES : 0;
94			break;
95		default:
96			return -EINVAL;
97	}
98	if (acl) {
99		size = posix_acl_xattr_size(acl->a_count);
100		value = kmalloc(size, GFP_KERNEL);
101		if (!value)
102			return -ENOMEM;
103		rc = posix_acl_to_xattr(acl, value, size);
104		if (rc < 0)
105			goto out;
106	}
107	rc = __jfs_setxattr(tid, inode, ea_name, value, size, 0);
108out:
109	kfree(value);
110
111	if (!rc)
112		set_cached_acl(inode, type, acl);
113
114	return rc;
115}
116
117int jfs_check_acl(struct inode *inode, int mask)
118{
119	struct posix_acl *acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
120
121	if (IS_ERR(acl))
122		return PTR_ERR(acl);
123	if (acl) {
124		int error = posix_acl_permission(inode, acl, mask);
125		posix_acl_release(acl);
126		return error;
127	}
128
129	return -EAGAIN;
130}
131
132int jfs_init_acl(tid_t tid, struct inode *inode, struct inode *dir)
133{
134	struct posix_acl *acl = NULL;
135	struct posix_acl *clone;
136	mode_t mode;
137	int rc = 0;
138
139	if (S_ISLNK(inode->i_mode))
140		return 0;
141
142	acl = jfs_get_acl(dir, ACL_TYPE_DEFAULT);
143	if (IS_ERR(acl))
144		return PTR_ERR(acl);
145
146	if (acl) {
147		if (S_ISDIR(inode->i_mode)) {
148			rc = jfs_set_acl(tid, inode, ACL_TYPE_DEFAULT, acl);
149			if (rc)
150				goto cleanup;
151		}
152		clone = posix_acl_clone(acl, GFP_KERNEL);
153		if (!clone) {
154			rc = -ENOMEM;
155			goto cleanup;
156		}
157		mode = inode->i_mode;
158		rc = posix_acl_create_masq(clone, &mode);
159		if (rc >= 0) {
160			inode->i_mode = mode;
161			if (rc > 0)
162				rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS,
163						 clone);
164		}
165		posix_acl_release(clone);
166cleanup:
167		posix_acl_release(acl);
168	} else
169		inode->i_mode &= ~current_umask();
170
171	JFS_IP(inode)->mode2 = (JFS_IP(inode)->mode2 & 0xffff0000) |
172			       inode->i_mode;
173
174	return rc;
175}
176
177int jfs_acl_chmod(struct inode *inode)
178{
179	struct posix_acl *acl, *clone;
180	int rc;
181
182	if (S_ISLNK(inode->i_mode))
183		return -EOPNOTSUPP;
184
185	acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
186	if (IS_ERR(acl) || !acl)
187		return PTR_ERR(acl);
188
189	clone = posix_acl_clone(acl, GFP_KERNEL);
190	posix_acl_release(acl);
191	if (!clone)
192		return -ENOMEM;
193
194	rc = posix_acl_chmod_masq(clone, inode->i_mode);
195	if (!rc) {
196		tid_t tid = txBegin(inode->i_sb, 0);
197		mutex_lock(&JFS_IP(inode)->commit_mutex);
198		rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, clone);
199		if (!rc)
200			rc = txCommit(tid, 1, &inode, 0);
201		txEnd(tid);
202		mutex_unlock(&JFS_IP(inode)->commit_mutex);
203	}
204
205	posix_acl_release(clone);
206	return rc;
207}
208