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5103e947 JB |
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> | |
33268eaf | 23 | #include <linux/posix_acl.h> |
c1e32da6 | 24 | #include <linux/sched.h> |
33268eaf | 25 | |
5103e947 | 26 | #include "ctree.h" |
33268eaf | 27 | #include "btrfs_inode.h" |
5103e947 | 28 | #include "xattr.h" |
33268eaf | 29 | |
eab922ec JB |
30 | #ifdef CONFIG_FS_POSIX_ACL |
31 | ||
33268eaf JB |
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 | { | |
95819c05 CH |
45 | int size; |
46 | const char *name; | |
33268eaf JB |
47 | char *value = NULL; |
48 | struct posix_acl *acl = NULL, **p_acl; | |
49 | ||
50 | switch (type) { | |
51 | case ACL_TYPE_ACCESS: | |
95819c05 | 52 | name = POSIX_ACL_XATTR_ACCESS; |
33268eaf JB |
53 | p_acl = &BTRFS_I(inode)->i_acl; |
54 | break; | |
55 | case ACL_TYPE_DEFAULT: | |
95819c05 | 56 | name = POSIX_ACL_XATTR_DEFAULT; |
33268eaf JB |
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 | ||
95819c05 | 72 | size = __btrfs_getxattr(inode, name, "", 0); |
33268eaf JB |
73 | if (size > 0) { |
74 | value = kzalloc(size, GFP_NOFS); | |
75 | if (!value) | |
76 | return ERR_PTR(-ENOMEM); | |
95819c05 | 77 | size = __btrfs_getxattr(inode, name, value, size); |
33268eaf JB |
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 | { | |
95819c05 CH |
114 | int ret, size = 0; |
115 | const char *name; | |
33268eaf JB |
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; | |
95819c05 | 135 | name = POSIX_ACL_XATTR_ACCESS; |
33268eaf JB |
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; | |
95819c05 | 141 | name = POSIX_ACL_XATTR_DEFAULT; |
33268eaf JB |
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 | ||
95819c05 | 161 | ret = __btrfs_setxattr(inode, name, value, size, 0); |
33268eaf JB |
162 | |
163 | out: | |
d397712b | 164 | kfree(value); |
33268eaf JB |
165 | |
166 | if (!ret) | |
167 | btrfs_update_cached_acl(inode, p_acl, acl); | |
168 | ||
169 | return ret; | |
170 | } | |
fb4bc1e0 | 171 | |
744f52f9 Y |
172 | static int btrfs_xattr_set_acl(struct inode *inode, int type, |
173 | const void *value, size_t size) | |
174 | { | |
175 | int ret = 0; | |
33268eaf | 176 | struct posix_acl *acl = NULL; |
5103e947 | 177 | |
744f52f9 Y |
178 | if (value) { |
179 | acl = posix_acl_from_xattr(value, size); | |
180 | if (acl == NULL) { | |
181 | value = NULL; | |
182 | size = 0; | |
183 | } else if (IS_ERR(acl)) { | |
33268eaf | 184 | return PTR_ERR(acl); |
744f52f9 | 185 | } |
744f52f9 | 186 | } |
1caf9342 | 187 | |
33268eaf JB |
188 | ret = btrfs_set_acl(inode, acl, type); |
189 | ||
190 | posix_acl_release(acl); | |
191 | ||
192 | return ret; | |
744f52f9 | 193 | } |
33268eaf JB |
194 | |
195 | ||
5103e947 JB |
196 | static int btrfs_xattr_acl_access_get(struct inode *inode, const char *name, |
197 | void *value, size_t size) | |
198 | { | |
33268eaf | 199 | return btrfs_xattr_get_acl(inode, ACL_TYPE_ACCESS, value, size); |
5103e947 | 200 | } |
33268eaf | 201 | |
5103e947 JB |
202 | static int btrfs_xattr_acl_access_set(struct inode *inode, const char *name, |
203 | const void *value, size_t size, int flags) | |
204 | { | |
33268eaf | 205 | return btrfs_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size); |
5103e947 | 206 | } |
33268eaf | 207 | |
5103e947 JB |
208 | static int btrfs_xattr_acl_default_get(struct inode *inode, const char *name, |
209 | void *value, size_t size) | |
210 | { | |
33268eaf | 211 | return btrfs_xattr_get_acl(inode, ACL_TYPE_DEFAULT, value, size); |
5103e947 | 212 | } |
33268eaf | 213 | |
5103e947 | 214 | static int btrfs_xattr_acl_default_set(struct inode *inode, const char *name, |
d397712b | 215 | const void *value, size_t size, int flags) |
5103e947 | 216 | { |
33268eaf JB |
217 | return btrfs_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size); |
218 | } | |
219 | ||
220 | int btrfs_check_acl(struct inode *inode, int mask) | |
221 | { | |
222 | struct posix_acl *acl; | |
223 | int error = -EAGAIN; | |
224 | ||
225 | acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS); | |
226 | ||
227 | if (IS_ERR(acl)) | |
228 | return PTR_ERR(acl); | |
229 | if (acl) { | |
230 | error = posix_acl_permission(inode, acl, mask); | |
231 | posix_acl_release(acl); | |
232 | } | |
233 | ||
234 | return error; | |
235 | } | |
236 | ||
237 | /* | |
238 | * btrfs_init_acl is already generally called under fs_mutex, so the locking | |
239 | * stuff has been fixed to work with that. If the locking stuff changes, we | |
240 | * need to re-evaluate the acl locking stuff. | |
241 | */ | |
242 | int btrfs_init_acl(struct inode *inode, struct inode *dir) | |
243 | { | |
244 | struct posix_acl *acl = NULL; | |
245 | int ret = 0; | |
246 | ||
247 | /* this happens with subvols */ | |
248 | if (!dir) | |
249 | return 0; | |
250 | ||
251 | if (!S_ISLNK(inode->i_mode)) { | |
252 | if (IS_POSIXACL(dir)) { | |
253 | acl = btrfs_get_acl(dir, ACL_TYPE_DEFAULT); | |
254 | if (IS_ERR(acl)) | |
255 | return PTR_ERR(acl); | |
256 | } | |
257 | ||
258 | if (!acl) | |
259 | inode->i_mode &= ~current->fs->umask; | |
260 | } | |
261 | ||
262 | if (IS_POSIXACL(dir) && acl) { | |
263 | struct posix_acl *clone; | |
264 | mode_t mode; | |
265 | ||
266 | if (S_ISDIR(inode->i_mode)) { | |
267 | ret = btrfs_set_acl(inode, acl, ACL_TYPE_DEFAULT); | |
268 | if (ret) | |
269 | goto failed; | |
270 | } | |
271 | clone = posix_acl_clone(acl, GFP_NOFS); | |
272 | ret = -ENOMEM; | |
273 | if (!clone) | |
274 | goto failed; | |
275 | ||
276 | mode = inode->i_mode; | |
277 | ret = posix_acl_create_masq(clone, &mode); | |
278 | if (ret >= 0) { | |
279 | inode->i_mode = mode; | |
280 | if (ret > 0) { | |
281 | /* we need an acl */ | |
282 | ret = btrfs_set_acl(inode, clone, | |
283 | ACL_TYPE_ACCESS); | |
284 | } | |
285 | } | |
286 | } | |
287 | failed: | |
288 | posix_acl_release(acl); | |
289 | ||
290 | return ret; | |
291 | } | |
292 | ||
293 | int btrfs_acl_chmod(struct inode *inode) | |
294 | { | |
295 | struct posix_acl *acl, *clone; | |
296 | int ret = 0; | |
297 | ||
298 | if (S_ISLNK(inode->i_mode)) | |
299 | return -EOPNOTSUPP; | |
300 | ||
301 | if (!IS_POSIXACL(inode)) | |
302 | return 0; | |
303 | ||
304 | acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS); | |
305 | if (IS_ERR(acl) || !acl) | |
306 | return PTR_ERR(acl); | |
307 | ||
308 | clone = posix_acl_clone(acl, GFP_KERNEL); | |
309 | posix_acl_release(acl); | |
310 | if (!clone) | |
311 | return -ENOMEM; | |
312 | ||
313 | ret = posix_acl_chmod_masq(clone, inode->i_mode); | |
314 | if (!ret) | |
315 | ret = btrfs_set_acl(inode, clone, ACL_TYPE_ACCESS); | |
316 | ||
317 | posix_acl_release(clone); | |
318 | ||
319 | return ret; | |
5103e947 | 320 | } |
33268eaf | 321 | |
5103e947 JB |
322 | struct xattr_handler btrfs_xattr_acl_default_handler = { |
323 | .prefix = POSIX_ACL_XATTR_DEFAULT, | |
5103e947 JB |
324 | .get = btrfs_xattr_acl_default_get, |
325 | .set = btrfs_xattr_acl_default_set, | |
326 | }; | |
327 | ||
328 | struct xattr_handler btrfs_xattr_acl_access_handler = { | |
329 | .prefix = POSIX_ACL_XATTR_ACCESS, | |
5103e947 JB |
330 | .get = btrfs_xattr_acl_access_get, |
331 | .set = btrfs_xattr_acl_access_set, | |
332 | }; | |
eab922ec JB |
333 | |
334 | #else /* CONFIG_FS_POSIX_ACL */ | |
335 | ||
336 | int btrfs_acl_chmod(struct inode *inode) | |
337 | { | |
338 | return 0; | |
339 | } | |
340 | ||
341 | int btrfs_init_acl(struct inode *inode, struct inode *dir) | |
342 | { | |
343 | return 0; | |
344 | } | |
345 | ||
346 | int btrfs_check_acl(struct inode *inode, int mask) | |
347 | { | |
348 | return 0; | |
349 | } | |
350 | ||
351 | #endif /* CONFIG_FS_POSIX_ACL */ |