1 /*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
4 *
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.
8 */
9
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>
19
20 #include "gfs2.h"
21 #include "incore.h"
22 #include "acl.h"
23 #include "xattr.h"
24 #include "glock.h"
25 #include "inode.h"
26 #include "meta_io.h"
27 #include "trans.h"
28 #include "util.h"
29
gfs2_acl_name(int type)30 static const char *gfs2_acl_name(int type)
31 {
32 switch (type) {
33 case ACL_TYPE_ACCESS:
34 return GFS2_POSIX_ACL_ACCESS;
35 case ACL_TYPE_DEFAULT:
36 return GFS2_POSIX_ACL_DEFAULT;
37 }
38 return NULL;
39 }
40
gfs2_get_acl(struct inode * inode,int type)41 struct posix_acl *gfs2_get_acl(struct inode *inode, int type)
42 {
43 struct gfs2_inode *ip = GFS2_I(inode);
44 struct posix_acl *acl;
45 const char *name;
46 char *data;
47 int len;
48
49 if (!ip->i_eattr)
50 return NULL;
51
52 acl = get_cached_acl(&ip->i_inode, type);
53 if (acl != ACL_NOT_CACHED)
54 return acl;
55
56 name = gfs2_acl_name(type);
57 if (name == NULL)
58 return ERR_PTR(-EINVAL);
59
60 len = gfs2_xattr_acl_get(ip, name, &data);
61 if (len < 0)
62 return ERR_PTR(len);
63 if (len == 0)
64 return NULL;
65
66 acl = posix_acl_from_xattr(&init_user_ns, data, len);
67 kfree(data);
68 return acl;
69 }
70
gfs2_set_mode(struct inode * inode,umode_t mode)71 static int gfs2_set_mode(struct inode *inode, umode_t mode)
72 {
73 int error = 0;
74
75 if (mode != inode->i_mode) {
76 inode->i_mode = mode;
77 mark_inode_dirty(inode);
78 }
79
80 return error;
81 }
82
gfs2_acl_set(struct inode * inode,int type,struct posix_acl * acl)83 static int gfs2_acl_set(struct inode *inode, int type, struct posix_acl *acl)
84 {
85 int error;
86 int len;
87 char *data;
88 const char *name = gfs2_acl_name(type);
89
90 BUG_ON(name == NULL);
91 len = posix_acl_to_xattr(&init_user_ns, acl, NULL, 0);
92 if (len == 0)
93 return 0;
94 data = kmalloc(len, GFP_NOFS);
95 if (data == NULL)
96 return -ENOMEM;
97 error = posix_acl_to_xattr(&init_user_ns, acl, data, len);
98 if (error < 0)
99 goto out;
100 error = __gfs2_xattr_set(inode, name, data, len, 0, GFS2_EATYPE_SYS);
101 if (!error)
102 set_cached_acl(inode, type, acl);
103 out:
104 kfree(data);
105 return error;
106 }
107
gfs2_acl_create(struct gfs2_inode * dip,struct inode * inode)108 int gfs2_acl_create(struct gfs2_inode *dip, struct inode *inode)
109 {
110 struct gfs2_sbd *sdp = GFS2_SB(&dip->i_inode);
111 struct posix_acl *acl;
112 umode_t mode = inode->i_mode;
113 int error = 0;
114
115 if (!sdp->sd_args.ar_posix_acl)
116 return 0;
117 if (S_ISLNK(inode->i_mode))
118 return 0;
119
120 acl = gfs2_get_acl(&dip->i_inode, ACL_TYPE_DEFAULT);
121 if (IS_ERR(acl))
122 return PTR_ERR(acl);
123 if (!acl) {
124 mode &= ~current_umask();
125 return gfs2_set_mode(inode, mode);
126 }
127
128 if (S_ISDIR(inode->i_mode)) {
129 error = gfs2_acl_set(inode, ACL_TYPE_DEFAULT, acl);
130 if (error)
131 goto out;
132 }
133
134 error = posix_acl_create(&acl, GFP_NOFS, &mode);
135 if (error < 0)
136 return error;
137
138 if (error == 0)
139 goto munge;
140
141 error = gfs2_acl_set(inode, ACL_TYPE_ACCESS, acl);
142 if (error)
143 goto out;
144 munge:
145 error = gfs2_set_mode(inode, mode);
146 out:
147 posix_acl_release(acl);
148 return error;
149 }
150
gfs2_acl_chmod(struct gfs2_inode * ip,struct iattr * attr)151 int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr)
152 {
153 struct inode *inode = &ip->i_inode;
154 struct posix_acl *acl;
155 char *data;
156 unsigned int len;
157 int error;
158
159 acl = gfs2_get_acl(&ip->i_inode, ACL_TYPE_ACCESS);
160 if (IS_ERR(acl))
161 return PTR_ERR(acl);
162 if (!acl)
163 return gfs2_setattr_simple(inode, attr);
164
165 error = posix_acl_chmod(&acl, GFP_NOFS, attr->ia_mode);
166 if (error)
167 return error;
168
169 len = posix_acl_to_xattr(&init_user_ns, acl, NULL, 0);
170 data = kmalloc(len, GFP_NOFS);
171 error = -ENOMEM;
172 if (data == NULL)
173 goto out;
174 posix_acl_to_xattr(&init_user_ns, acl, data, len);
175 error = gfs2_xattr_acl_chmod(ip, attr, data);
176 kfree(data);
177 set_cached_acl(&ip->i_inode, ACL_TYPE_ACCESS, acl);
178
179 out:
180 posix_acl_release(acl);
181 return error;
182 }
183
gfs2_acl_type(const char * name)184 static int gfs2_acl_type(const char *name)
185 {
186 if (strcmp(name, GFS2_POSIX_ACL_ACCESS) == 0)
187 return ACL_TYPE_ACCESS;
188 if (strcmp(name, GFS2_POSIX_ACL_DEFAULT) == 0)
189 return ACL_TYPE_DEFAULT;
190 return -EINVAL;
191 }
192
gfs2_xattr_system_get(struct dentry * dentry,const char * name,void * buffer,size_t size,int xtype)193 static int gfs2_xattr_system_get(struct dentry *dentry, const char *name,
194 void *buffer, size_t size, int xtype)
195 {
196 struct inode *inode = dentry->d_inode;
197 struct gfs2_sbd *sdp = GFS2_SB(inode);
198 struct posix_acl *acl;
199 int type;
200 int error;
201
202 if (!sdp->sd_args.ar_posix_acl)
203 return -EOPNOTSUPP;
204
205 type = gfs2_acl_type(name);
206 if (type < 0)
207 return type;
208
209 acl = gfs2_get_acl(inode, type);
210 if (IS_ERR(acl))
211 return PTR_ERR(acl);
212 if (acl == NULL)
213 return -ENODATA;
214
215 error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
216 posix_acl_release(acl);
217
218 return error;
219 }
220
gfs2_xattr_system_set(struct dentry * dentry,const char * name,const void * value,size_t size,int flags,int xtype)221 static int gfs2_xattr_system_set(struct dentry *dentry, const char *name,
222 const void *value, size_t size, int flags,
223 int xtype)
224 {
225 struct inode *inode = dentry->d_inode;
226 struct gfs2_sbd *sdp = GFS2_SB(inode);
227 struct posix_acl *acl = NULL;
228 int error = 0, type;
229
230 if (!sdp->sd_args.ar_posix_acl)
231 return -EOPNOTSUPP;
232
233 type = gfs2_acl_type(name);
234 if (type < 0)
235 return type;
236 if (flags & XATTR_CREATE)
237 return -EINVAL;
238 if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
239 return value ? -EACCES : 0;
240 if (!uid_eq(current_fsuid(), inode->i_uid) && !capable(CAP_FOWNER))
241 return -EPERM;
242 if (S_ISLNK(inode->i_mode))
243 return -EOPNOTSUPP;
244
245 if (!value)
246 goto set_acl;
247
248 acl = posix_acl_from_xattr(&init_user_ns, value, size);
249 if (!acl) {
250 /*
251 * acl_set_file(3) may request that we set default ACLs with
252 * zero length -- defend (gracefully) against that here.
253 */
254 goto out;
255 }
256 if (IS_ERR(acl)) {
257 error = PTR_ERR(acl);
258 goto out;
259 }
260
261 error = posix_acl_valid(acl);
262 if (error)
263 goto out_release;
264
265 error = -EINVAL;
266 if (acl->a_count > GFS2_ACL_MAX_ENTRIES)
267 goto out_release;
268
269 if (type == ACL_TYPE_ACCESS) {
270 umode_t mode = inode->i_mode;
271 struct posix_acl *old_acl = acl;
272 error = posix_acl_update_mode(inode, &inode->i_mode, &acl);
273
274 if (!acl)
275 posix_acl_release(old_acl);
276 if (error)
277 goto out_release;
278
279 error = gfs2_set_mode(inode, mode);
280 if (error)
281 goto out_release;
282 }
283
284 set_acl:
285 error = __gfs2_xattr_set(inode, name, value, size, 0, GFS2_EATYPE_SYS);
286 if (!error) {
287 if (acl)
288 set_cached_acl(inode, type, acl);
289 else
290 forget_cached_acl(inode, type);
291 }
292 out_release:
293 posix_acl_release(acl);
294 out:
295 return error;
296 }
297
298 const struct xattr_handler gfs2_xattr_system_handler = {
299 .prefix = XATTR_SYSTEM_PREFIX,
300 .flags = GFS2_EATYPE_SYS,
301 .get = gfs2_xattr_system_get,
302 .set = gfs2_xattr_system_set,
303 };
304
305