xref: /openbmc/linux/fs/jfs/acl.c (revision 171f1bc7)
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 
30 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 
75 static 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);
108 out:
109 	kfree(value);
110 
111 	if (!rc)
112 		set_cached_acl(inode, type, acl);
113 
114 	return rc;
115 }
116 
117 int jfs_init_acl(tid_t tid, struct inode *inode, struct inode *dir)
118 {
119 	struct posix_acl *acl = NULL;
120 	int rc = 0;
121 
122 	if (S_ISLNK(inode->i_mode))
123 		return 0;
124 
125 	acl = jfs_get_acl(dir, ACL_TYPE_DEFAULT);
126 	if (IS_ERR(acl))
127 		return PTR_ERR(acl);
128 
129 	if (acl) {
130 		if (S_ISDIR(inode->i_mode)) {
131 			rc = jfs_set_acl(tid, inode, ACL_TYPE_DEFAULT, acl);
132 			if (rc)
133 				goto cleanup;
134 		}
135 		rc = posix_acl_create(&acl, GFP_KERNEL, &inode->i_mode);
136 		if (rc < 0)
137 			goto cleanup; /* posix_acl_release(NULL) is no-op */
138 		if (rc > 0)
139 			rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, acl);
140 cleanup:
141 		posix_acl_release(acl);
142 	} else
143 		inode->i_mode &= ~current_umask();
144 
145 	JFS_IP(inode)->mode2 = (JFS_IP(inode)->mode2 & 0xffff0000) |
146 			       inode->i_mode;
147 
148 	return rc;
149 }
150 
151 int jfs_acl_chmod(struct inode *inode)
152 {
153 	struct posix_acl *acl;
154 	int rc;
155 	tid_t tid;
156 
157 	if (S_ISLNK(inode->i_mode))
158 		return -EOPNOTSUPP;
159 
160 	acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
161 	if (IS_ERR(acl) || !acl)
162 		return PTR_ERR(acl);
163 
164 	rc = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
165 	if (rc)
166 		return rc;
167 
168 	tid = txBegin(inode->i_sb, 0);
169 	mutex_lock(&JFS_IP(inode)->commit_mutex);
170 	rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, acl);
171 	if (!rc)
172 		rc = txCommit(tid, 1, &inode, 0);
173 	txEnd(tid);
174 	mutex_unlock(&JFS_IP(inode)->commit_mutex);
175 
176 	posix_acl_release(acl);
177 	return rc;
178 }
179