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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 JB |
29 | |
30 | static void btrfs_update_cached_acl(struct inode *inode, | |
31 | struct posix_acl **p_acl, | |
32 | struct posix_acl *acl) | |
33 | { | |
34 | spin_lock(&inode->i_lock); | |
35 | if (*p_acl && *p_acl != BTRFS_ACL_NOT_CACHED) | |
36 | posix_acl_release(*p_acl); | |
37 | *p_acl = posix_acl_dup(acl); | |
38 | spin_unlock(&inode->i_lock); | |
39 | } | |
40 | ||
41 | static struct posix_acl *btrfs_get_acl(struct inode *inode, int type) | |
42 | { | |
43 | int size, name_index; | |
44 | char *value = NULL; | |
45 | struct posix_acl *acl = NULL, **p_acl; | |
46 | ||
47 | switch (type) { | |
48 | case ACL_TYPE_ACCESS: | |
49 | name_index = BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS; | |
50 | p_acl = &BTRFS_I(inode)->i_acl; | |
51 | break; | |
52 | case ACL_TYPE_DEFAULT: | |
53 | name_index = BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT; | |
54 | p_acl = &BTRFS_I(inode)->i_default_acl; | |
55 | break; | |
56 | default: | |
57 | return ERR_PTR(-EINVAL); | |
58 | } | |
59 | ||
60 | spin_lock(&inode->i_lock); | |
61 | if (*p_acl != BTRFS_ACL_NOT_CACHED) | |
62 | acl = posix_acl_dup(*p_acl); | |
63 | spin_unlock(&inode->i_lock); | |
64 | ||
65 | if (acl) | |
66 | return acl; | |
67 | ||
68 | ||
69 | size = btrfs_xattr_get(inode, name_index, "", NULL, 0); | |
70 | if (size > 0) { | |
71 | value = kzalloc(size, GFP_NOFS); | |
72 | if (!value) | |
73 | return ERR_PTR(-ENOMEM); | |
74 | size = btrfs_xattr_get(inode, name_index, "", value, size); | |
75 | if (size > 0) { | |
76 | acl = posix_acl_from_xattr(value, size); | |
77 | btrfs_update_cached_acl(inode, p_acl, acl); | |
78 | } | |
79 | kfree(value); | |
80 | } else if (size == -ENOENT) { | |
81 | acl = NULL; | |
82 | btrfs_update_cached_acl(inode, p_acl, acl); | |
83 | } | |
84 | ||
85 | return acl; | |
86 | } | |
87 | ||
88 | static int btrfs_xattr_get_acl(struct inode *inode, int type, | |
89 | void *value, size_t size) | |
90 | { | |
91 | struct posix_acl *acl; | |
92 | int ret = 0; | |
93 | ||
94 | acl = btrfs_get_acl(inode, type); | |
95 | ||
96 | if (IS_ERR(acl)) | |
97 | return PTR_ERR(acl); | |
98 | if (acl == NULL) | |
99 | return -ENODATA; | |
100 | ret = posix_acl_to_xattr(acl, value, size); | |
101 | posix_acl_release(acl); | |
102 | ||
103 | return ret; | |
104 | } | |
105 | ||
106 | /* | |
107 | * Needs to be called with fs_mutex held | |
108 | */ | |
109 | static int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type) | |
110 | { | |
111 | int ret, name_index = 0, size = 0; | |
112 | struct posix_acl **p_acl; | |
113 | char *value = NULL; | |
114 | mode_t mode; | |
115 | ||
116 | if (acl) { | |
117 | ret = posix_acl_valid(acl); | |
118 | if (ret < 0) | |
119 | return ret; | |
120 | ret = 0; | |
121 | } | |
122 | ||
123 | switch (type) { | |
124 | case ACL_TYPE_ACCESS: | |
125 | mode = inode->i_mode; | |
126 | ret = posix_acl_equiv_mode(acl, &mode); | |
127 | if (ret < 0) | |
128 | return ret; | |
129 | ret = 0; | |
130 | inode->i_mode = mode; | |
131 | name_index = BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS; | |
132 | p_acl = &BTRFS_I(inode)->i_acl; | |
133 | break; | |
134 | case ACL_TYPE_DEFAULT: | |
135 | if (!S_ISDIR(inode->i_mode)) | |
136 | return acl ? -EINVAL : 0; | |
137 | name_index = BTRFS_XATTR_INDEX_POSIX_ACL_DEFAULT; | |
138 | p_acl = &BTRFS_I(inode)->i_default_acl; | |
139 | break; | |
140 | default: | |
141 | return -EINVAL; | |
142 | } | |
143 | ||
144 | if (acl) { | |
145 | size = posix_acl_xattr_size(acl->a_count); | |
146 | value = kmalloc(size, GFP_NOFS); | |
147 | if (!value) { | |
148 | ret = -ENOMEM; | |
149 | goto out; | |
150 | } | |
151 | ||
152 | ret = posix_acl_to_xattr(acl, value, size); | |
153 | if (ret < 0) | |
154 | goto out; | |
155 | } | |
156 | ||
157 | ret = btrfs_xattr_set(inode, name_index, "", value, size, 0); | |
158 | ||
159 | out: | |
160 | if (value) | |
161 | kfree(value); | |
162 | ||
163 | if (!ret) | |
164 | btrfs_update_cached_acl(inode, p_acl, acl); | |
165 | ||
166 | return ret; | |
167 | } | |
fb4bc1e0 | 168 | |
744f52f9 Y |
169 | static int btrfs_xattr_set_acl(struct inode *inode, int type, |
170 | const void *value, size_t size) | |
171 | { | |
172 | int ret = 0; | |
33268eaf | 173 | struct posix_acl *acl = NULL; |
5103e947 | 174 | |
744f52f9 Y |
175 | if (value) { |
176 | acl = posix_acl_from_xattr(value, size); | |
177 | if (acl == NULL) { | |
178 | value = NULL; | |
179 | size = 0; | |
180 | } else if (IS_ERR(acl)) { | |
33268eaf | 181 | return PTR_ERR(acl); |
744f52f9 | 182 | } |
744f52f9 | 183 | } |
1caf9342 | 184 | |
33268eaf JB |
185 | ret = btrfs_set_acl(inode, acl, type); |
186 | ||
187 | posix_acl_release(acl); | |
188 | ||
189 | return ret; | |
744f52f9 | 190 | } |
33268eaf JB |
191 | |
192 | ||
5103e947 JB |
193 | static int btrfs_xattr_acl_access_get(struct inode *inode, const char *name, |
194 | void *value, size_t size) | |
195 | { | |
33268eaf | 196 | return btrfs_xattr_get_acl(inode, ACL_TYPE_ACCESS, value, size); |
5103e947 | 197 | } |
33268eaf | 198 | |
5103e947 JB |
199 | static int btrfs_xattr_acl_access_set(struct inode *inode, const char *name, |
200 | const void *value, size_t size, int flags) | |
201 | { | |
33268eaf | 202 | return btrfs_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size); |
5103e947 | 203 | } |
33268eaf | 204 | |
5103e947 JB |
205 | static int btrfs_xattr_acl_default_get(struct inode *inode, const char *name, |
206 | void *value, size_t size) | |
207 | { | |
33268eaf | 208 | return btrfs_xattr_get_acl(inode, ACL_TYPE_DEFAULT, value, size); |
5103e947 | 209 | } |
33268eaf | 210 | |
5103e947 JB |
211 | static int btrfs_xattr_acl_default_set(struct inode *inode, const char *name, |
212 | const void *value, size_t size, int flags) | |
213 | { | |
33268eaf JB |
214 | return btrfs_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size); |
215 | } | |
216 | ||
217 | int btrfs_check_acl(struct inode *inode, int mask) | |
218 | { | |
219 | struct posix_acl *acl; | |
220 | int error = -EAGAIN; | |
221 | ||
222 | acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS); | |
223 | ||
224 | if (IS_ERR(acl)) | |
225 | return PTR_ERR(acl); | |
226 | if (acl) { | |
227 | error = posix_acl_permission(inode, acl, mask); | |
228 | posix_acl_release(acl); | |
229 | } | |
230 | ||
231 | return error; | |
232 | } | |
233 | ||
234 | /* | |
235 | * btrfs_init_acl is already generally called under fs_mutex, so the locking | |
236 | * stuff has been fixed to work with that. If the locking stuff changes, we | |
237 | * need to re-evaluate the acl locking stuff. | |
238 | */ | |
239 | int btrfs_init_acl(struct inode *inode, struct inode *dir) | |
240 | { | |
241 | struct posix_acl *acl = NULL; | |
242 | int ret = 0; | |
243 | ||
244 | /* this happens with subvols */ | |
245 | if (!dir) | |
246 | return 0; | |
247 | ||
248 | if (!S_ISLNK(inode->i_mode)) { | |
249 | if (IS_POSIXACL(dir)) { | |
250 | acl = btrfs_get_acl(dir, ACL_TYPE_DEFAULT); | |
251 | if (IS_ERR(acl)) | |
252 | return PTR_ERR(acl); | |
253 | } | |
254 | ||
255 | if (!acl) | |
256 | inode->i_mode &= ~current->fs->umask; | |
257 | } | |
258 | ||
259 | if (IS_POSIXACL(dir) && acl) { | |
260 | struct posix_acl *clone; | |
261 | mode_t mode; | |
262 | ||
263 | if (S_ISDIR(inode->i_mode)) { | |
264 | ret = btrfs_set_acl(inode, acl, ACL_TYPE_DEFAULT); | |
265 | if (ret) | |
266 | goto failed; | |
267 | } | |
268 | clone = posix_acl_clone(acl, GFP_NOFS); | |
269 | ret = -ENOMEM; | |
270 | if (!clone) | |
271 | goto failed; | |
272 | ||
273 | mode = inode->i_mode; | |
274 | ret = posix_acl_create_masq(clone, &mode); | |
275 | if (ret >= 0) { | |
276 | inode->i_mode = mode; | |
277 | if (ret > 0) { | |
278 | /* we need an acl */ | |
279 | ret = btrfs_set_acl(inode, clone, | |
280 | ACL_TYPE_ACCESS); | |
281 | } | |
282 | } | |
283 | } | |
284 | failed: | |
285 | posix_acl_release(acl); | |
286 | ||
287 | return ret; | |
288 | } | |
289 | ||
290 | int btrfs_acl_chmod(struct inode *inode) | |
291 | { | |
292 | struct posix_acl *acl, *clone; | |
293 | int ret = 0; | |
294 | ||
295 | if (S_ISLNK(inode->i_mode)) | |
296 | return -EOPNOTSUPP; | |
297 | ||
298 | if (!IS_POSIXACL(inode)) | |
299 | return 0; | |
300 | ||
301 | acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS); | |
302 | if (IS_ERR(acl) || !acl) | |
303 | return PTR_ERR(acl); | |
304 | ||
305 | clone = posix_acl_clone(acl, GFP_KERNEL); | |
306 | posix_acl_release(acl); | |
307 | if (!clone) | |
308 | return -ENOMEM; | |
309 | ||
310 | ret = posix_acl_chmod_masq(clone, inode->i_mode); | |
311 | if (!ret) | |
312 | ret = btrfs_set_acl(inode, clone, ACL_TYPE_ACCESS); | |
313 | ||
314 | posix_acl_release(clone); | |
315 | ||
316 | return ret; | |
5103e947 | 317 | } |
33268eaf | 318 | |
5103e947 JB |
319 | struct xattr_handler btrfs_xattr_acl_default_handler = { |
320 | .prefix = POSIX_ACL_XATTR_DEFAULT, | |
321 | .list = btrfs_xattr_generic_list, | |
322 | .get = btrfs_xattr_acl_default_get, | |
323 | .set = btrfs_xattr_acl_default_set, | |
324 | }; | |
325 | ||
326 | struct xattr_handler btrfs_xattr_acl_access_handler = { | |
327 | .prefix = POSIX_ACL_XATTR_ACCESS, | |
328 | .list = btrfs_xattr_generic_list, | |
329 | .get = btrfs_xattr_acl_access_get, | |
330 | .set = btrfs_xattr_acl_access_set, | |
331 | }; |