xref: /openbmc/linux/fs/jfs/acl.c (revision 37be287c)
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(&init_user_ns, 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 	switch (type) {
84 	case ACL_TYPE_ACCESS:
85 		ea_name = POSIX_ACL_XATTR_ACCESS;
86 		rc = posix_acl_equiv_mode(acl, &inode->i_mode);
87 		if (rc < 0)
88 			return rc;
89 		if (rc == 0)
90 			acl = NULL;
91 		break;
92 	case ACL_TYPE_DEFAULT:
93 		ea_name = POSIX_ACL_XATTR_DEFAULT;
94 		break;
95 	default:
96 		return -EINVAL;
97 	}
98 
99 	if (acl) {
100 		size = posix_acl_xattr_size(acl->a_count);
101 		value = kmalloc(size, GFP_KERNEL);
102 		if (!value)
103 			return -ENOMEM;
104 		rc = posix_acl_to_xattr(&init_user_ns, acl, value, size);
105 		if (rc < 0)
106 			goto out;
107 	}
108 	rc = __jfs_setxattr(tid, inode, ea_name, value, size, 0);
109 out:
110 	kfree(value);
111 
112 	if (!rc)
113 		set_cached_acl(inode, type, acl);
114 
115 	return rc;
116 }
117 
118 int jfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
119 {
120 	int rc;
121 	tid_t tid;
122 
123 	tid = txBegin(inode->i_sb, 0);
124 	mutex_lock(&JFS_IP(inode)->commit_mutex);
125 	rc = __jfs_set_acl(tid, inode, type, acl);
126 	if (!rc)
127 		rc = txCommit(tid, 1, &inode, 0);
128 	txEnd(tid);
129 	mutex_unlock(&JFS_IP(inode)->commit_mutex);
130 	return rc;
131 }
132 
133 int jfs_init_acl(tid_t tid, struct inode *inode, struct inode *dir)
134 {
135 	struct posix_acl *default_acl, *acl;
136 	int rc = 0;
137 
138 	rc = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
139 	if (rc)
140 		return rc;
141 
142 	if (default_acl) {
143 		rc = __jfs_set_acl(tid, inode, ACL_TYPE_DEFAULT, default_acl);
144 		posix_acl_release(default_acl);
145 	}
146 
147 	if (acl) {
148 		if (!rc)
149 			rc = __jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, acl);
150 		posix_acl_release(acl);
151 	}
152 
153 	JFS_IP(inode)->mode2 = (JFS_IP(inode)->mode2 & 0xffff0000) |
154 			       inode->i_mode;
155 
156 	return rc;
157 }
158