Commit | Line | Data |
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ef14f0c1 CH |
1 | /* |
2 | * Copyright (c) 2008, Christoph Hellwig | |
3 | * All Rights Reserved. | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or | |
6 | * modify it under the terms of the GNU General Public License as | |
7 | * published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it would be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write the Free Software Foundation, | |
16 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
17 | */ | |
18 | #include "xfs.h" | |
19 | #include "xfs_acl.h" | |
20 | #include "xfs_attr.h" | |
21 | #include "xfs_bmap_btree.h" | |
22 | #include "xfs_inode.h" | |
23 | #include "xfs_vnodeops.h" | |
0a8aa193 DC |
24 | #include "xfs_sb.h" |
25 | #include "xfs_mount.h" | |
0b1b213f | 26 | #include "xfs_trace.h" |
5a0e3ad6 | 27 | #include <linux/slab.h> |
ef14f0c1 CH |
28 | #include <linux/xattr.h> |
29 | #include <linux/posix_acl_xattr.h> | |
30 | ||
31 | ||
ef14f0c1 CH |
32 | /* |
33 | * Locking scheme: | |
34 | * - all ACL updates are protected by inode->i_mutex, which is taken before | |
35 | * calling into this file. | |
ef14f0c1 CH |
36 | */ |
37 | ||
38 | STATIC struct posix_acl * | |
0a8aa193 DC |
39 | xfs_acl_from_disk( |
40 | struct xfs_acl *aclp, | |
41 | int max_entries) | |
ef14f0c1 CH |
42 | { |
43 | struct posix_acl_entry *acl_e; | |
44 | struct posix_acl *acl; | |
45 | struct xfs_acl_entry *ace; | |
093019cf | 46 | unsigned int count, i; |
ef14f0c1 CH |
47 | |
48 | count = be32_to_cpu(aclp->acl_cnt); | |
0a8aa193 | 49 | if (count > max_entries) |
fa8b18ed | 50 | return ERR_PTR(-EFSCORRUPTED); |
ef14f0c1 CH |
51 | |
52 | acl = posix_acl_alloc(count, GFP_KERNEL); | |
53 | if (!acl) | |
54 | return ERR_PTR(-ENOMEM); | |
55 | ||
56 | for (i = 0; i < count; i++) { | |
57 | acl_e = &acl->a_entries[i]; | |
58 | ace = &aclp->acl_entry[i]; | |
59 | ||
60 | /* | |
61 | * The tag is 32 bits on disk and 16 bits in core. | |
62 | * | |
63 | * Because every access to it goes through the core | |
64 | * format first this is not a problem. | |
65 | */ | |
66 | acl_e->e_tag = be32_to_cpu(ace->ae_tag); | |
67 | acl_e->e_perm = be16_to_cpu(ace->ae_perm); | |
68 | ||
69 | switch (acl_e->e_tag) { | |
70 | case ACL_USER: | |
71 | case ACL_GROUP: | |
72 | acl_e->e_id = be32_to_cpu(ace->ae_id); | |
73 | break; | |
74 | case ACL_USER_OBJ: | |
75 | case ACL_GROUP_OBJ: | |
76 | case ACL_MASK: | |
77 | case ACL_OTHER: | |
78 | acl_e->e_id = ACL_UNDEFINED_ID; | |
79 | break; | |
80 | default: | |
81 | goto fail; | |
82 | } | |
83 | } | |
84 | return acl; | |
85 | ||
86 | fail: | |
87 | posix_acl_release(acl); | |
88 | return ERR_PTR(-EINVAL); | |
89 | } | |
90 | ||
91 | STATIC void | |
92 | xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl) | |
93 | { | |
94 | const struct posix_acl_entry *acl_e; | |
95 | struct xfs_acl_entry *ace; | |
96 | int i; | |
97 | ||
98 | aclp->acl_cnt = cpu_to_be32(acl->a_count); | |
99 | for (i = 0; i < acl->a_count; i++) { | |
100 | ace = &aclp->acl_entry[i]; | |
101 | acl_e = &acl->a_entries[i]; | |
102 | ||
103 | ace->ae_tag = cpu_to_be32(acl_e->e_tag); | |
104 | ace->ae_id = cpu_to_be32(acl_e->e_id); | |
105 | ace->ae_perm = cpu_to_be16(acl_e->e_perm); | |
106 | } | |
107 | } | |
108 | ||
ef14f0c1 CH |
109 | struct posix_acl * |
110 | xfs_get_acl(struct inode *inode, int type) | |
111 | { | |
112 | struct xfs_inode *ip = XFS_I(inode); | |
1cbd20d8 | 113 | struct posix_acl *acl; |
ef14f0c1 | 114 | struct xfs_acl *xfs_acl; |
a9273ca5 | 115 | unsigned char *ea_name; |
ef14f0c1 | 116 | int error; |
0a8aa193 | 117 | int len; |
ef14f0c1 | 118 | |
1cbd20d8 AV |
119 | acl = get_cached_acl(inode, type); |
120 | if (acl != ACL_NOT_CACHED) | |
121 | return acl; | |
122 | ||
4e34e719 CH |
123 | trace_xfs_get_acl(ip); |
124 | ||
ef14f0c1 CH |
125 | switch (type) { |
126 | case ACL_TYPE_ACCESS: | |
127 | ea_name = SGI_ACL_FILE; | |
ef14f0c1 CH |
128 | break; |
129 | case ACL_TYPE_DEFAULT: | |
130 | ea_name = SGI_ACL_DEFAULT; | |
ef14f0c1 CH |
131 | break; |
132 | default: | |
1cbd20d8 | 133 | BUG(); |
ef14f0c1 CH |
134 | } |
135 | ||
ef14f0c1 CH |
136 | /* |
137 | * If we have a cached ACLs value just return it, not need to | |
138 | * go out to the disk. | |
139 | */ | |
0a8aa193 DC |
140 | len = XFS_ACL_MAX_SIZE(ip->i_mount); |
141 | xfs_acl = kzalloc(len, GFP_KERNEL); | |
ef14f0c1 CH |
142 | if (!xfs_acl) |
143 | return ERR_PTR(-ENOMEM); | |
144 | ||
a9273ca5 DC |
145 | error = -xfs_attr_get(ip, ea_name, (unsigned char *)xfs_acl, |
146 | &len, ATTR_ROOT); | |
ef14f0c1 CH |
147 | if (error) { |
148 | /* | |
149 | * If the attribute doesn't exist make sure we have a negative | |
150 | * cache entry, for any other error assume it is transient and | |
1cbd20d8 | 151 | * leave the cache entry as ACL_NOT_CACHED. |
ef14f0c1 CH |
152 | */ |
153 | if (error == -ENOATTR) { | |
154 | acl = NULL; | |
155 | goto out_update_cache; | |
156 | } | |
157 | goto out; | |
158 | } | |
159 | ||
0a8aa193 | 160 | acl = xfs_acl_from_disk(xfs_acl, XFS_ACL_MAX_ENTRIES(ip->i_mount)); |
ef14f0c1 CH |
161 | if (IS_ERR(acl)) |
162 | goto out; | |
163 | ||
164 | out_update_cache: | |
1cbd20d8 | 165 | set_cached_acl(inode, type, acl); |
ef14f0c1 CH |
166 | out: |
167 | kfree(xfs_acl); | |
168 | return acl; | |
169 | } | |
170 | ||
171 | STATIC int | |
172 | xfs_set_acl(struct inode *inode, int type, struct posix_acl *acl) | |
173 | { | |
174 | struct xfs_inode *ip = XFS_I(inode); | |
a9273ca5 | 175 | unsigned char *ea_name; |
ef14f0c1 CH |
176 | int error; |
177 | ||
178 | if (S_ISLNK(inode->i_mode)) | |
179 | return -EOPNOTSUPP; | |
180 | ||
181 | switch (type) { | |
182 | case ACL_TYPE_ACCESS: | |
183 | ea_name = SGI_ACL_FILE; | |
ef14f0c1 CH |
184 | break; |
185 | case ACL_TYPE_DEFAULT: | |
186 | if (!S_ISDIR(inode->i_mode)) | |
187 | return acl ? -EACCES : 0; | |
188 | ea_name = SGI_ACL_DEFAULT; | |
ef14f0c1 CH |
189 | break; |
190 | default: | |
191 | return -EINVAL; | |
192 | } | |
193 | ||
194 | if (acl) { | |
195 | struct xfs_acl *xfs_acl; | |
0a8aa193 | 196 | int len = XFS_ACL_MAX_SIZE(ip->i_mount); |
ef14f0c1 | 197 | |
0a8aa193 | 198 | xfs_acl = kzalloc(len, GFP_KERNEL); |
ef14f0c1 CH |
199 | if (!xfs_acl) |
200 | return -ENOMEM; | |
201 | ||
202 | xfs_acl_to_disk(xfs_acl, acl); | |
0a8aa193 DC |
203 | |
204 | /* subtract away the unused acl entries */ | |
205 | len -= sizeof(struct xfs_acl_entry) * | |
206 | (XFS_ACL_MAX_ENTRIES(ip->i_mount) - acl->a_count); | |
ef14f0c1 | 207 | |
a9273ca5 | 208 | error = -xfs_attr_set(ip, ea_name, (unsigned char *)xfs_acl, |
ef14f0c1 CH |
209 | len, ATTR_ROOT); |
210 | ||
211 | kfree(xfs_acl); | |
212 | } else { | |
213 | /* | |
214 | * A NULL ACL argument means we want to remove the ACL. | |
215 | */ | |
216 | error = -xfs_attr_remove(ip, ea_name, ATTR_ROOT); | |
217 | ||
218 | /* | |
219 | * If the attribute didn't exist to start with that's fine. | |
220 | */ | |
221 | if (error == -ENOATTR) | |
222 | error = 0; | |
223 | } | |
224 | ||
225 | if (!error) | |
1cbd20d8 | 226 | set_cached_acl(inode, type, acl); |
ef14f0c1 CH |
227 | return error; |
228 | } | |
229 | ||
ef14f0c1 | 230 | static int |
d3fb6120 | 231 | xfs_set_mode(struct inode *inode, umode_t mode) |
ef14f0c1 CH |
232 | { |
233 | int error = 0; | |
234 | ||
235 | if (mode != inode->i_mode) { | |
236 | struct iattr iattr; | |
237 | ||
d6d59bad | 238 | iattr.ia_valid = ATTR_MODE | ATTR_CTIME; |
ef14f0c1 | 239 | iattr.ia_mode = mode; |
d6d59bad | 240 | iattr.ia_ctime = current_fs_time(inode->i_sb); |
ef14f0c1 | 241 | |
c4ed4243 | 242 | error = -xfs_setattr_nonsize(XFS_I(inode), &iattr, XFS_ATTR_NOACL); |
ef14f0c1 CH |
243 | } |
244 | ||
245 | return error; | |
246 | } | |
247 | ||
248 | static int | |
a9273ca5 | 249 | xfs_acl_exists(struct inode *inode, unsigned char *name) |
ef14f0c1 | 250 | { |
0a8aa193 | 251 | int len = XFS_ACL_MAX_SIZE(XFS_M(inode->i_sb)); |
ef14f0c1 CH |
252 | |
253 | return (xfs_attr_get(XFS_I(inode), name, NULL, &len, | |
254 | ATTR_ROOT|ATTR_KERNOVAL) == 0); | |
255 | } | |
256 | ||
257 | int | |
258 | posix_acl_access_exists(struct inode *inode) | |
259 | { | |
260 | return xfs_acl_exists(inode, SGI_ACL_FILE); | |
261 | } | |
262 | ||
263 | int | |
264 | posix_acl_default_exists(struct inode *inode) | |
265 | { | |
266 | if (!S_ISDIR(inode->i_mode)) | |
267 | return 0; | |
268 | return xfs_acl_exists(inode, SGI_ACL_DEFAULT); | |
269 | } | |
270 | ||
271 | /* | |
272 | * No need for i_mutex because the inode is not yet exposed to the VFS. | |
273 | */ | |
274 | int | |
826cae2f | 275 | xfs_inherit_acl(struct inode *inode, struct posix_acl *acl) |
ef14f0c1 | 276 | { |
d3fb6120 | 277 | umode_t mode = inode->i_mode; |
ef14f0c1 CH |
278 | int error = 0, inherit = 0; |
279 | ||
280 | if (S_ISDIR(inode->i_mode)) { | |
826cae2f | 281 | error = xfs_set_acl(inode, ACL_TYPE_DEFAULT, acl); |
ef14f0c1 | 282 | if (error) |
826cae2f | 283 | goto out; |
ef14f0c1 CH |
284 | } |
285 | ||
826cae2f | 286 | error = posix_acl_create(&acl, GFP_KERNEL, &mode); |
ef14f0c1 | 287 | if (error < 0) |
826cae2f | 288 | return error; |
ef14f0c1 CH |
289 | |
290 | /* | |
826cae2f | 291 | * If posix_acl_create returns a positive value we need to |
ef14f0c1 CH |
292 | * inherit a permission that can't be represented using the Unix |
293 | * mode bits and we actually need to set an ACL. | |
294 | */ | |
295 | if (error > 0) | |
296 | inherit = 1; | |
297 | ||
298 | error = xfs_set_mode(inode, mode); | |
299 | if (error) | |
826cae2f | 300 | goto out; |
ef14f0c1 CH |
301 | |
302 | if (inherit) | |
826cae2f | 303 | error = xfs_set_acl(inode, ACL_TYPE_ACCESS, acl); |
ef14f0c1 | 304 | |
826cae2f AV |
305 | out: |
306 | posix_acl_release(acl); | |
ef14f0c1 CH |
307 | return error; |
308 | } | |
309 | ||
310 | int | |
311 | xfs_acl_chmod(struct inode *inode) | |
312 | { | |
bc26ab5f | 313 | struct posix_acl *acl; |
ef14f0c1 CH |
314 | int error; |
315 | ||
316 | if (S_ISLNK(inode->i_mode)) | |
317 | return -EOPNOTSUPP; | |
318 | ||
319 | acl = xfs_get_acl(inode, ACL_TYPE_ACCESS); | |
320 | if (IS_ERR(acl) || !acl) | |
321 | return PTR_ERR(acl); | |
322 | ||
bc26ab5f AV |
323 | error = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode); |
324 | if (error) | |
325 | return error; | |
ef14f0c1 | 326 | |
bc26ab5f AV |
327 | error = xfs_set_acl(inode, ACL_TYPE_ACCESS, acl); |
328 | posix_acl_release(acl); | |
ef14f0c1 CH |
329 | return error; |
330 | } | |
331 | ||
ef14f0c1 | 332 | static int |
431547b3 CH |
333 | xfs_xattr_acl_get(struct dentry *dentry, const char *name, |
334 | void *value, size_t size, int type) | |
ef14f0c1 CH |
335 | { |
336 | struct posix_acl *acl; | |
431547b3 | 337 | int error; |
ef14f0c1 | 338 | |
431547b3 | 339 | acl = xfs_get_acl(dentry->d_inode, type); |
ef14f0c1 CH |
340 | if (IS_ERR(acl)) |
341 | return PTR_ERR(acl); | |
342 | if (acl == NULL) | |
343 | return -ENODATA; | |
344 | ||
5f3a4a28 | 345 | error = posix_acl_to_xattr(&init_user_ns, acl, value, size); |
ef14f0c1 CH |
346 | posix_acl_release(acl); |
347 | ||
348 | return error; | |
349 | } | |
350 | ||
351 | static int | |
431547b3 CH |
352 | xfs_xattr_acl_set(struct dentry *dentry, const char *name, |
353 | const void *value, size_t size, int flags, int type) | |
ef14f0c1 | 354 | { |
431547b3 | 355 | struct inode *inode = dentry->d_inode; |
ef14f0c1 | 356 | struct posix_acl *acl = NULL; |
431547b3 | 357 | int error = 0; |
ef14f0c1 | 358 | |
ef14f0c1 CH |
359 | if (flags & XATTR_CREATE) |
360 | return -EINVAL; | |
361 | if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode)) | |
362 | return value ? -EACCES : 0; | |
363 | if ((current_fsuid() != inode->i_uid) && !capable(CAP_FOWNER)) | |
364 | return -EPERM; | |
365 | ||
366 | if (!value) | |
367 | goto set_acl; | |
368 | ||
5f3a4a28 | 369 | acl = posix_acl_from_xattr(&init_user_ns, value, size); |
ef14f0c1 CH |
370 | if (!acl) { |
371 | /* | |
372 | * acl_set_file(3) may request that we set default ACLs with | |
373 | * zero length -- defend (gracefully) against that here. | |
374 | */ | |
375 | goto out; | |
376 | } | |
377 | if (IS_ERR(acl)) { | |
378 | error = PTR_ERR(acl); | |
379 | goto out; | |
380 | } | |
381 | ||
382 | error = posix_acl_valid(acl); | |
383 | if (error) | |
384 | goto out_release; | |
385 | ||
386 | error = -EINVAL; | |
0a8aa193 | 387 | if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb))) |
ef14f0c1 CH |
388 | goto out_release; |
389 | ||
390 | if (type == ACL_TYPE_ACCESS) { | |
d6952123 | 391 | umode_t mode = inode->i_mode; |
ef14f0c1 CH |
392 | error = posix_acl_equiv_mode(acl, &mode); |
393 | ||
394 | if (error <= 0) { | |
395 | posix_acl_release(acl); | |
396 | acl = NULL; | |
397 | ||
398 | if (error < 0) | |
399 | return error; | |
400 | } | |
401 | ||
402 | error = xfs_set_mode(inode, mode); | |
403 | if (error) | |
404 | goto out_release; | |
405 | } | |
406 | ||
407 | set_acl: | |
408 | error = xfs_set_acl(inode, type, acl); | |
409 | out_release: | |
410 | posix_acl_release(acl); | |
411 | out: | |
412 | return error; | |
413 | } | |
414 | ||
46e58764 | 415 | const struct xattr_handler xfs_xattr_acl_access_handler = { |
431547b3 CH |
416 | .prefix = POSIX_ACL_XATTR_ACCESS, |
417 | .flags = ACL_TYPE_ACCESS, | |
418 | .get = xfs_xattr_acl_get, | |
419 | .set = xfs_xattr_acl_set, | |
420 | }; | |
421 | ||
46e58764 | 422 | const struct xattr_handler xfs_xattr_acl_default_handler = { |
431547b3 CH |
423 | .prefix = POSIX_ACL_XATTR_DEFAULT, |
424 | .flags = ACL_TYPE_DEFAULT, | |
425 | .get = xfs_xattr_acl_get, | |
426 | .set = xfs_xattr_acl_set, | |
ef14f0c1 | 427 | }; |