diff options
Diffstat (limited to 'fs/btrfs/acl.c')
-rw-r--r-- | fs/btrfs/acl.c | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c new file mode 100644 index 000000000000..867eaf1f8efb --- /dev/null +++ b/fs/btrfs/acl.c | |||
@@ -0,0 +1,352 @@ | |||
1 | /* | ||
2 | * Copyright (C) 2007 Red Hat. All rights reserved. | ||
3 | * | ||
4 | * This program is free software; you can redistribute it and/or | ||
5 | * modify it under the terms of the GNU General Public | ||
6 | * License v2 as published by the Free Software Foundation. | ||
7 | * | ||
8 | * This program is distributed in the hope that it will be useful, | ||
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
11 | * General Public License for more details. | ||
12 | * | ||
13 | * You should have received a copy of the GNU General Public | ||
14 | * License along with this program; if not, write to the | ||
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | ||
16 | * Boston, MA 021110-1307, USA. | ||
17 | */ | ||
18 | |||
19 | #include <linux/fs.h> | ||
20 | #include <linux/string.h> | ||
21 | #include <linux/xattr.h> | ||
22 | #include <linux/posix_acl_xattr.h> | ||
23 | #include <linux/posix_acl.h> | ||
24 | #include <linux/sched.h> | ||
25 | |||
26 | #include "ctree.h" | ||
27 | #include "btrfs_inode.h" | ||
28 | #include "xattr.h" | ||
29 | |||
30 | #ifdef CONFIG_FS_POSIX_ACL | ||
31 | |||
32 | static void btrfs_update_cached_acl(struct inode *inode, | ||
33 | struct posix_acl **p_acl, | ||
34 | struct posix_acl *acl) | ||
35 | { | ||
36 | spin_lock(&inode->i_lock); | ||
37 | if (*p_acl && *p_acl != BTRFS_ACL_NOT_CACHED) | ||
38 | posix_acl_release(*p_acl); | ||
39 | *p_acl = posix_acl_dup(acl); | ||
40 | spin_unlock(&inode->i_lock); | ||
41 | } | ||
42 | |||
43 | static struct posix_acl *btrfs_get_acl(struct inode *inode, int type) | ||
44 | { | ||
45 | int size; | ||
46 | const char *name; | ||
47 | char *value = NULL; | ||
48 | struct posix_acl *acl = NULL, **p_acl; | ||
49 | |||
50 | switch (type) { | ||
51 | case ACL_TYPE_ACCESS: | ||
52 | name = POSIX_ACL_XATTR_ACCESS; | ||
53 | p_acl = &BTRFS_I(inode)->i_acl; | ||
54 | break; | ||
55 | case ACL_TYPE_DEFAULT: | ||
56 | name = POSIX_ACL_XATTR_DEFAULT; | ||
57 | p_acl = &BTRFS_I(inode)->i_default_acl; | ||
58 | break; | ||
59 | default: | ||
60 | return ERR_PTR(-EINVAL); | ||
61 | } | ||
62 | |||
63 | spin_lock(&inode->i_lock); | ||
64 | if (*p_acl != BTRFS_ACL_NOT_CACHED) | ||
65 | acl = posix_acl_dup(*p_acl); | ||
66 | spin_unlock(&inode->i_lock); | ||
67 | |||
68 | if (acl) | ||
69 | return acl; | ||
70 | |||
71 | |||
72 | size = __btrfs_getxattr(inode, name, "", 0); | ||
73 | if (size > 0) { | ||
74 | value = kzalloc(size, GFP_NOFS); | ||
75 | if (!value) | ||
76 | return ERR_PTR(-ENOMEM); | ||
77 | size = __btrfs_getxattr(inode, name, value, size); | ||
78 | if (size > 0) { | ||
79 | acl = posix_acl_from_xattr(value, size); | ||
80 | btrfs_update_cached_acl(inode, p_acl, acl); | ||
81 | } | ||
82 | kfree(value); | ||
83 | } else if (size == -ENOENT) { | ||
84 | acl = NULL; | ||
85 | btrfs_update_cached_acl(inode, p_acl, acl); | ||
86 | } | ||
87 | |||
88 | return acl; | ||
89 | } | ||
90 | |||
91 | static int btrfs_xattr_get_acl(struct inode *inode, int type, | ||
92 | void *value, size_t size) | ||
93 | { | ||
94 | struct posix_acl *acl; | ||
95 | int ret = 0; | ||
96 | |||
97 | acl = btrfs_get_acl(inode, type); | ||
98 | |||
99 | if (IS_ERR(acl)) | ||
100 | return PTR_ERR(acl); | ||
101 | if (acl == NULL) | ||
102 | return -ENODATA; | ||
103 | ret = posix_acl_to_xattr(acl, value, size); | ||
104 | posix_acl_release(acl); | ||
105 | |||
106 | return ret; | ||
107 | } | ||
108 | |||
109 | /* | ||
110 | * Needs to be called with fs_mutex held | ||
111 | */ | ||
112 | static int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type) | ||
113 | { | ||
114 | int ret, size = 0; | ||
115 | const char *name; | ||
116 | struct posix_acl **p_acl; | ||
117 | char *value = NULL; | ||
118 | mode_t mode; | ||
119 | |||
120 | if (acl) { | ||
121 | ret = posix_acl_valid(acl); | ||
122 | if (ret < 0) | ||
123 | return ret; | ||
124 | ret = 0; | ||
125 | } | ||
126 | |||
127 | switch (type) { | ||
128 | case ACL_TYPE_ACCESS: | ||
129 | mode = inode->i_mode; | ||
130 | ret = posix_acl_equiv_mode(acl, &mode); | ||
131 | if (ret < 0) | ||
132 | return ret; | ||
133 | ret = 0; | ||
134 | inode->i_mode = mode; | ||
135 | name = POSIX_ACL_XATTR_ACCESS; | ||
136 | p_acl = &BTRFS_I(inode)->i_acl; | ||
137 | break; | ||
138 | case ACL_TYPE_DEFAULT: | ||
139 | if (!S_ISDIR(inode->i_mode)) | ||
140 | return acl ? -EINVAL : 0; | ||
141 | name = POSIX_ACL_XATTR_DEFAULT; | ||
142 | p_acl = &BTRFS_I(inode)->i_default_acl; | ||
143 | break; | ||
144 | default: | ||
145 | return -EINVAL; | ||
146 | } | ||
147 | |||
148 | if (acl) { | ||
149 | size = posix_acl_xattr_size(acl->a_count); | ||
150 | value = kmalloc(size, GFP_NOFS); | ||
151 | if (!value) { | ||
152 | ret = -ENOMEM; | ||
153 | goto out; | ||
154 | } | ||
155 | |||
156 | ret = posix_acl_to_xattr(acl, value, size); | ||
157 | if (ret < 0) | ||
158 | goto out; | ||
159 | } | ||
160 | |||
161 | ret = __btrfs_setxattr(inode, name, value, size, 0); | ||
162 | |||
163 | out: | ||
164 | if (value) | ||
165 | kfree(value); | ||
166 | |||
167 | if (!ret) | ||
168 | btrfs_update_cached_acl(inode, p_acl, acl); | ||
169 | |||
170 | return ret; | ||
171 | } | ||
172 | |||
173 | static int btrfs_xattr_set_acl(struct inode *inode, int type, | ||
174 | const void *value, size_t size) | ||
175 | { | ||
176 | int ret = 0; | ||
177 | struct posix_acl *acl = NULL; | ||
178 | |||
179 | if (value) { | ||
180 | acl = posix_acl_from_xattr(value, size); | ||
181 | if (acl == NULL) { | ||
182 | value = NULL; | ||
183 | size = 0; | ||
184 | } else if (IS_ERR(acl)) { | ||
185 | return PTR_ERR(acl); | ||
186 | } | ||
187 | } | ||
188 | |||
189 | ret = btrfs_set_acl(inode, acl, type); | ||
190 | |||
191 | posix_acl_release(acl); | ||
192 | |||
193 | return ret; | ||
194 | } | ||
195 | |||
196 | |||
197 | static int btrfs_xattr_acl_access_get(struct inode *inode, const char *name, | ||
198 | void *value, size_t size) | ||
199 | { | ||
200 | return btrfs_xattr_get_acl(inode, ACL_TYPE_ACCESS, value, size); | ||
201 | } | ||
202 | |||
203 | static int btrfs_xattr_acl_access_set(struct inode *inode, const char *name, | ||
204 | const void *value, size_t size, int flags) | ||
205 | { | ||
206 | return btrfs_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size); | ||
207 | } | ||
208 | |||
209 | static int btrfs_xattr_acl_default_get(struct inode *inode, const char *name, | ||
210 | void *value, size_t size) | ||
211 | { | ||
212 | return btrfs_xattr_get_acl(inode, ACL_TYPE_DEFAULT, value, size); | ||
213 | } | ||
214 | |||
215 | static int btrfs_xattr_acl_default_set(struct inode *inode, const char *name, | ||
216 | const void *value, size_t size, int flags) | ||
217 | { | ||
218 | return btrfs_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size); | ||
219 | } | ||
220 | |||
221 | int btrfs_check_acl(struct inode *inode, int mask) | ||
222 | { | ||
223 | struct posix_acl *acl; | ||
224 | int error = -EAGAIN; | ||
225 | |||
226 | acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS); | ||
227 | |||
228 | if (IS_ERR(acl)) | ||
229 | return PTR_ERR(acl); | ||
230 | if (acl) { | ||
231 | error = posix_acl_permission(inode, acl, mask); | ||
232 | posix_acl_release(acl); | ||
233 | } | ||
234 | |||
235 | return error; | ||
236 | } | ||
237 | |||
238 | /* | ||
239 | * btrfs_init_acl is already generally called under fs_mutex, so the locking | ||
240 | * stuff has been fixed to work with that. If the locking stuff changes, we | ||
241 | * need to re-evaluate the acl locking stuff. | ||
242 | */ | ||
243 | int btrfs_init_acl(struct inode *inode, struct inode *dir) | ||
244 | { | ||
245 | struct posix_acl *acl = NULL; | ||
246 | int ret = 0; | ||
247 | |||
248 | /* this happens with subvols */ | ||
249 | if (!dir) | ||
250 | return 0; | ||
251 | |||
252 | if (!S_ISLNK(inode->i_mode)) { | ||
253 | if (IS_POSIXACL(dir)) { | ||
254 | acl = btrfs_get_acl(dir, ACL_TYPE_DEFAULT); | ||
255 | if (IS_ERR(acl)) | ||
256 | return PTR_ERR(acl); | ||
257 | } | ||
258 | |||
259 | if (!acl) | ||
260 | inode->i_mode &= ~current->fs->umask; | ||
261 | } | ||
262 | |||
263 | if (IS_POSIXACL(dir) && acl) { | ||
264 | struct posix_acl *clone; | ||
265 | mode_t mode; | ||
266 | |||
267 | if (S_ISDIR(inode->i_mode)) { | ||
268 | ret = btrfs_set_acl(inode, acl, ACL_TYPE_DEFAULT); | ||
269 | if (ret) | ||
270 | goto failed; | ||
271 | } | ||
272 | clone = posix_acl_clone(acl, GFP_NOFS); | ||
273 | ret = -ENOMEM; | ||
274 | if (!clone) | ||
275 | goto failed; | ||
276 | |||
277 | mode = inode->i_mode; | ||
278 | ret = posix_acl_create_masq(clone, &mode); | ||
279 | if (ret >= 0) { | ||
280 | inode->i_mode = mode; | ||
281 | if (ret > 0) { | ||
282 | /* we need an acl */ | ||
283 | ret = btrfs_set_acl(inode, clone, | ||
284 | ACL_TYPE_ACCESS); | ||
285 | } | ||
286 | } | ||
287 | } | ||
288 | failed: | ||
289 | posix_acl_release(acl); | ||
290 | |||
291 | return ret; | ||
292 | } | ||
293 | |||
294 | int btrfs_acl_chmod(struct inode *inode) | ||
295 | { | ||
296 | struct posix_acl *acl, *clone; | ||
297 | int ret = 0; | ||
298 | |||
299 | if (S_ISLNK(inode->i_mode)) | ||
300 | return -EOPNOTSUPP; | ||
301 | |||
302 | if (!IS_POSIXACL(inode)) | ||
303 | return 0; | ||
304 | |||
305 | acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS); | ||
306 | if (IS_ERR(acl) || !acl) | ||
307 | return PTR_ERR(acl); | ||
308 | |||
309 | clone = posix_acl_clone(acl, GFP_KERNEL); | ||
310 | posix_acl_release(acl); | ||
311 | if (!clone) | ||
312 | return -ENOMEM; | ||
313 | |||
314 | ret = posix_acl_chmod_masq(clone, inode->i_mode); | ||
315 | if (!ret) | ||
316 | ret = btrfs_set_acl(inode, clone, ACL_TYPE_ACCESS); | ||
317 | |||
318 | posix_acl_release(clone); | ||
319 | |||
320 | return ret; | ||
321 | } | ||
322 | |||
323 | struct xattr_handler btrfs_xattr_acl_default_handler = { | ||
324 | .prefix = POSIX_ACL_XATTR_DEFAULT, | ||
325 | .get = btrfs_xattr_acl_default_get, | ||
326 | .set = btrfs_xattr_acl_default_set, | ||
327 | }; | ||
328 | |||
329 | struct xattr_handler btrfs_xattr_acl_access_handler = { | ||
330 | .prefix = POSIX_ACL_XATTR_ACCESS, | ||
331 | .get = btrfs_xattr_acl_access_get, | ||
332 | .set = btrfs_xattr_acl_access_set, | ||
333 | }; | ||
334 | |||
335 | #else /* CONFIG_FS_POSIX_ACL */ | ||
336 | |||
337 | int btrfs_acl_chmod(struct inode *inode) | ||
338 | { | ||
339 | return 0; | ||
340 | } | ||
341 | |||
342 | int btrfs_init_acl(struct inode *inode, struct inode *dir) | ||
343 | { | ||
344 | return 0; | ||
345 | } | ||
346 | |||
347 | int btrfs_check_acl(struct inode *inode, int mask) | ||
348 | { | ||
349 | return 0; | ||
350 | } | ||
351 | |||
352 | #endif /* CONFIG_FS_POSIX_ACL */ | ||