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" | |
a4fbe6ab | 19 | #include "xfs_format.h" |
69432832 | 20 | #include "xfs_log_format.h" |
7fd36c44 | 21 | #include "xfs_trans_resv.h" |
9356fe22 | 22 | #include "xfs_ag.h" |
0a8aa193 DC |
23 | #include "xfs_sb.h" |
24 | #include "xfs_mount.h" | |
a4fbe6ab DC |
25 | #include "xfs_inode.h" |
26 | #include "xfs_acl.h" | |
27 | #include "xfs_attr.h" | |
0b1b213f | 28 | #include "xfs_trace.h" |
5a0e3ad6 | 29 | #include <linux/slab.h> |
ef14f0c1 CH |
30 | #include <linux/xattr.h> |
31 | #include <linux/posix_acl_xattr.h> | |
32 | ||
33 | ||
ef14f0c1 CH |
34 | /* |
35 | * Locking scheme: | |
36 | * - all ACL updates are protected by inode->i_mutex, which is taken before | |
37 | * calling into this file. | |
ef14f0c1 CH |
38 | */ |
39 | ||
40 | STATIC struct posix_acl * | |
0a8aa193 DC |
41 | xfs_acl_from_disk( |
42 | struct xfs_acl *aclp, | |
43 | int max_entries) | |
ef14f0c1 CH |
44 | { |
45 | struct posix_acl_entry *acl_e; | |
46 | struct posix_acl *acl; | |
47 | struct xfs_acl_entry *ace; | |
093019cf | 48 | unsigned int count, i; |
ef14f0c1 CH |
49 | |
50 | count = be32_to_cpu(aclp->acl_cnt); | |
0a8aa193 | 51 | if (count > max_entries) |
fa8b18ed | 52 | return ERR_PTR(-EFSCORRUPTED); |
ef14f0c1 CH |
53 | |
54 | acl = posix_acl_alloc(count, GFP_KERNEL); | |
55 | if (!acl) | |
56 | return ERR_PTR(-ENOMEM); | |
57 | ||
58 | for (i = 0; i < count; i++) { | |
59 | acl_e = &acl->a_entries[i]; | |
60 | ace = &aclp->acl_entry[i]; | |
61 | ||
62 | /* | |
63 | * The tag is 32 bits on disk and 16 bits in core. | |
64 | * | |
65 | * Because every access to it goes through the core | |
66 | * format first this is not a problem. | |
67 | */ | |
68 | acl_e->e_tag = be32_to_cpu(ace->ae_tag); | |
69 | acl_e->e_perm = be16_to_cpu(ace->ae_perm); | |
70 | ||
71 | switch (acl_e->e_tag) { | |
72 | case ACL_USER: | |
288bbe0e DE |
73 | acl_e->e_uid = xfs_uid_to_kuid(be32_to_cpu(ace->ae_id)); |
74 | break; | |
ef14f0c1 | 75 | case ACL_GROUP: |
288bbe0e | 76 | acl_e->e_gid = xfs_gid_to_kgid(be32_to_cpu(ace->ae_id)); |
ef14f0c1 CH |
77 | break; |
78 | case ACL_USER_OBJ: | |
79 | case ACL_GROUP_OBJ: | |
80 | case ACL_MASK: | |
81 | case ACL_OTHER: | |
ef14f0c1 CH |
82 | break; |
83 | default: | |
84 | goto fail; | |
85 | } | |
86 | } | |
87 | return acl; | |
88 | ||
89 | fail: | |
90 | posix_acl_release(acl); | |
91 | return ERR_PTR(-EINVAL); | |
92 | } | |
93 | ||
94 | STATIC void | |
95 | xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl) | |
96 | { | |
97 | const struct posix_acl_entry *acl_e; | |
98 | struct xfs_acl_entry *ace; | |
99 | int i; | |
100 | ||
101 | aclp->acl_cnt = cpu_to_be32(acl->a_count); | |
102 | for (i = 0; i < acl->a_count; i++) { | |
103 | ace = &aclp->acl_entry[i]; | |
104 | acl_e = &acl->a_entries[i]; | |
105 | ||
106 | ace->ae_tag = cpu_to_be32(acl_e->e_tag); | |
288bbe0e DE |
107 | switch (acl_e->e_tag) { |
108 | case ACL_USER: | |
109 | ace->ae_id = cpu_to_be32(xfs_kuid_to_uid(acl_e->e_uid)); | |
110 | break; | |
111 | case ACL_GROUP: | |
112 | ace->ae_id = cpu_to_be32(xfs_kgid_to_gid(acl_e->e_gid)); | |
113 | break; | |
114 | default: | |
115 | ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID); | |
116 | break; | |
117 | } | |
118 | ||
ef14f0c1 CH |
119 | ace->ae_perm = cpu_to_be16(acl_e->e_perm); |
120 | } | |
121 | } | |
122 | ||
ef14f0c1 CH |
123 | struct posix_acl * |
124 | xfs_get_acl(struct inode *inode, int type) | |
125 | { | |
126 | struct xfs_inode *ip = XFS_I(inode); | |
1cbd20d8 | 127 | struct posix_acl *acl; |
ef14f0c1 | 128 | struct xfs_acl *xfs_acl; |
a9273ca5 | 129 | unsigned char *ea_name; |
ef14f0c1 | 130 | int error; |
0a8aa193 | 131 | int len; |
ef14f0c1 | 132 | |
1cbd20d8 AV |
133 | acl = get_cached_acl(inode, type); |
134 | if (acl != ACL_NOT_CACHED) | |
135 | return acl; | |
136 | ||
4e34e719 CH |
137 | trace_xfs_get_acl(ip); |
138 | ||
ef14f0c1 CH |
139 | switch (type) { |
140 | case ACL_TYPE_ACCESS: | |
141 | ea_name = SGI_ACL_FILE; | |
ef14f0c1 CH |
142 | break; |
143 | case ACL_TYPE_DEFAULT: | |
144 | ea_name = SGI_ACL_DEFAULT; | |
ef14f0c1 CH |
145 | break; |
146 | default: | |
1cbd20d8 | 147 | BUG(); |
ef14f0c1 CH |
148 | } |
149 | ||
ef14f0c1 CH |
150 | /* |
151 | * If we have a cached ACLs value just return it, not need to | |
152 | * go out to the disk. | |
153 | */ | |
0a8aa193 | 154 | len = XFS_ACL_MAX_SIZE(ip->i_mount); |
fdd3ccee DC |
155 | xfs_acl = kmem_zalloc_large(len, KM_SLEEP); |
156 | if (!xfs_acl) | |
157 | return ERR_PTR(-ENOMEM); | |
ef14f0c1 | 158 | |
a9273ca5 DC |
159 | error = -xfs_attr_get(ip, ea_name, (unsigned char *)xfs_acl, |
160 | &len, ATTR_ROOT); | |
ef14f0c1 CH |
161 | if (error) { |
162 | /* | |
163 | * If the attribute doesn't exist make sure we have a negative | |
164 | * cache entry, for any other error assume it is transient and | |
1cbd20d8 | 165 | * leave the cache entry as ACL_NOT_CACHED. |
ef14f0c1 CH |
166 | */ |
167 | if (error == -ENOATTR) { | |
168 | acl = NULL; | |
169 | goto out_update_cache; | |
170 | } | |
171 | goto out; | |
172 | } | |
173 | ||
0a8aa193 | 174 | acl = xfs_acl_from_disk(xfs_acl, XFS_ACL_MAX_ENTRIES(ip->i_mount)); |
ef14f0c1 CH |
175 | if (IS_ERR(acl)) |
176 | goto out; | |
177 | ||
2dc164f2 | 178 | out_update_cache: |
1cbd20d8 | 179 | set_cached_acl(inode, type, acl); |
2dc164f2 | 180 | out: |
fdd3ccee | 181 | kmem_free(xfs_acl); |
ef14f0c1 CH |
182 | return acl; |
183 | } | |
184 | ||
185 | STATIC int | |
186 | xfs_set_acl(struct inode *inode, int type, struct posix_acl *acl) | |
187 | { | |
188 | struct xfs_inode *ip = XFS_I(inode); | |
a9273ca5 | 189 | unsigned char *ea_name; |
ef14f0c1 CH |
190 | int error; |
191 | ||
192 | if (S_ISLNK(inode->i_mode)) | |
193 | return -EOPNOTSUPP; | |
194 | ||
195 | switch (type) { | |
196 | case ACL_TYPE_ACCESS: | |
197 | ea_name = SGI_ACL_FILE; | |
ef14f0c1 CH |
198 | break; |
199 | case ACL_TYPE_DEFAULT: | |
200 | if (!S_ISDIR(inode->i_mode)) | |
201 | return acl ? -EACCES : 0; | |
202 | ea_name = SGI_ACL_DEFAULT; | |
ef14f0c1 CH |
203 | break; |
204 | default: | |
205 | return -EINVAL; | |
206 | } | |
207 | ||
208 | if (acl) { | |
209 | struct xfs_acl *xfs_acl; | |
0a8aa193 | 210 | int len = XFS_ACL_MAX_SIZE(ip->i_mount); |
ef14f0c1 | 211 | |
fdd3ccee DC |
212 | xfs_acl = kmem_zalloc_large(len, KM_SLEEP); |
213 | if (!xfs_acl) | |
214 | return -ENOMEM; | |
ef14f0c1 CH |
215 | |
216 | xfs_acl_to_disk(xfs_acl, acl); | |
0a8aa193 DC |
217 | |
218 | /* subtract away the unused acl entries */ | |
219 | len -= sizeof(struct xfs_acl_entry) * | |
220 | (XFS_ACL_MAX_ENTRIES(ip->i_mount) - acl->a_count); | |
ef14f0c1 | 221 | |
a9273ca5 | 222 | error = -xfs_attr_set(ip, ea_name, (unsigned char *)xfs_acl, |
ef14f0c1 CH |
223 | len, ATTR_ROOT); |
224 | ||
fdd3ccee | 225 | kmem_free(xfs_acl); |
ef14f0c1 CH |
226 | } else { |
227 | /* | |
228 | * A NULL ACL argument means we want to remove the ACL. | |
229 | */ | |
230 | error = -xfs_attr_remove(ip, ea_name, ATTR_ROOT); | |
231 | ||
232 | /* | |
233 | * If the attribute didn't exist to start with that's fine. | |
234 | */ | |
235 | if (error == -ENOATTR) | |
236 | error = 0; | |
237 | } | |
238 | ||
239 | if (!error) | |
1cbd20d8 | 240 | set_cached_acl(inode, type, acl); |
ef14f0c1 CH |
241 | return error; |
242 | } | |
243 | ||
ef14f0c1 | 244 | static int |
d3fb6120 | 245 | xfs_set_mode(struct inode *inode, umode_t mode) |
ef14f0c1 CH |
246 | { |
247 | int error = 0; | |
248 | ||
249 | if (mode != inode->i_mode) { | |
250 | struct iattr iattr; | |
251 | ||
d6d59bad | 252 | iattr.ia_valid = ATTR_MODE | ATTR_CTIME; |
ef14f0c1 | 253 | iattr.ia_mode = mode; |
d6d59bad | 254 | iattr.ia_ctime = current_fs_time(inode->i_sb); |
ef14f0c1 | 255 | |
c4ed4243 | 256 | error = -xfs_setattr_nonsize(XFS_I(inode), &iattr, XFS_ATTR_NOACL); |
ef14f0c1 CH |
257 | } |
258 | ||
259 | return error; | |
260 | } | |
261 | ||
262 | static int | |
a9273ca5 | 263 | xfs_acl_exists(struct inode *inode, unsigned char *name) |
ef14f0c1 | 264 | { |
0a8aa193 | 265 | int len = XFS_ACL_MAX_SIZE(XFS_M(inode->i_sb)); |
ef14f0c1 CH |
266 | |
267 | return (xfs_attr_get(XFS_I(inode), name, NULL, &len, | |
268 | ATTR_ROOT|ATTR_KERNOVAL) == 0); | |
269 | } | |
270 | ||
271 | int | |
272 | posix_acl_access_exists(struct inode *inode) | |
273 | { | |
274 | return xfs_acl_exists(inode, SGI_ACL_FILE); | |
275 | } | |
276 | ||
277 | int | |
278 | posix_acl_default_exists(struct inode *inode) | |
279 | { | |
280 | if (!S_ISDIR(inode->i_mode)) | |
281 | return 0; | |
282 | return xfs_acl_exists(inode, SGI_ACL_DEFAULT); | |
283 | } | |
284 | ||
285 | /* | |
286 | * No need for i_mutex because the inode is not yet exposed to the VFS. | |
287 | */ | |
288 | int | |
826cae2f | 289 | xfs_inherit_acl(struct inode *inode, struct posix_acl *acl) |
ef14f0c1 | 290 | { |
d3fb6120 | 291 | umode_t mode = inode->i_mode; |
ef14f0c1 CH |
292 | int error = 0, inherit = 0; |
293 | ||
294 | if (S_ISDIR(inode->i_mode)) { | |
826cae2f | 295 | error = xfs_set_acl(inode, ACL_TYPE_DEFAULT, acl); |
ef14f0c1 | 296 | if (error) |
826cae2f | 297 | goto out; |
ef14f0c1 CH |
298 | } |
299 | ||
37bc1539 | 300 | error = __posix_acl_create(&acl, GFP_KERNEL, &mode); |
ef14f0c1 | 301 | if (error < 0) |
826cae2f | 302 | return error; |
ef14f0c1 CH |
303 | |
304 | /* | |
37bc1539 | 305 | * If __posix_acl_create returns a positive value we need to |
ef14f0c1 CH |
306 | * inherit a permission that can't be represented using the Unix |
307 | * mode bits and we actually need to set an ACL. | |
308 | */ | |
309 | if (error > 0) | |
310 | inherit = 1; | |
311 | ||
312 | error = xfs_set_mode(inode, mode); | |
313 | if (error) | |
826cae2f | 314 | goto out; |
ef14f0c1 CH |
315 | |
316 | if (inherit) | |
826cae2f | 317 | error = xfs_set_acl(inode, ACL_TYPE_ACCESS, acl); |
ef14f0c1 | 318 | |
826cae2f AV |
319 | out: |
320 | posix_acl_release(acl); | |
ef14f0c1 CH |
321 | return error; |
322 | } | |
323 | ||
324 | int | |
325 | xfs_acl_chmod(struct inode *inode) | |
326 | { | |
bc26ab5f | 327 | struct posix_acl *acl; |
ef14f0c1 CH |
328 | int error; |
329 | ||
330 | if (S_ISLNK(inode->i_mode)) | |
331 | return -EOPNOTSUPP; | |
332 | ||
333 | acl = xfs_get_acl(inode, ACL_TYPE_ACCESS); | |
334 | if (IS_ERR(acl) || !acl) | |
335 | return PTR_ERR(acl); | |
336 | ||
5bf3258f | 337 | error = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode); |
bc26ab5f AV |
338 | if (error) |
339 | return error; | |
ef14f0c1 | 340 | |
bc26ab5f AV |
341 | error = xfs_set_acl(inode, ACL_TYPE_ACCESS, acl); |
342 | posix_acl_release(acl); | |
ef14f0c1 CH |
343 | return error; |
344 | } | |
345 | ||
ef14f0c1 | 346 | static int |
431547b3 CH |
347 | xfs_xattr_acl_get(struct dentry *dentry, const char *name, |
348 | void *value, size_t size, int type) | |
ef14f0c1 CH |
349 | { |
350 | struct posix_acl *acl; | |
431547b3 | 351 | int error; |
ef14f0c1 | 352 | |
431547b3 | 353 | acl = xfs_get_acl(dentry->d_inode, type); |
ef14f0c1 CH |
354 | if (IS_ERR(acl)) |
355 | return PTR_ERR(acl); | |
356 | if (acl == NULL) | |
357 | return -ENODATA; | |
358 | ||
5f3a4a28 | 359 | error = posix_acl_to_xattr(&init_user_ns, acl, value, size); |
ef14f0c1 CH |
360 | posix_acl_release(acl); |
361 | ||
362 | return error; | |
363 | } | |
364 | ||
365 | static int | |
431547b3 CH |
366 | xfs_xattr_acl_set(struct dentry *dentry, const char *name, |
367 | const void *value, size_t size, int flags, int type) | |
ef14f0c1 | 368 | { |
431547b3 | 369 | struct inode *inode = dentry->d_inode; |
ef14f0c1 | 370 | struct posix_acl *acl = NULL; |
431547b3 | 371 | int error = 0; |
ef14f0c1 | 372 | |
ef14f0c1 CH |
373 | if (flags & XATTR_CREATE) |
374 | return -EINVAL; | |
375 | if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode)) | |
376 | return value ? -EACCES : 0; | |
288bbe0e | 377 | if (!inode_owner_or_capable(inode)) |
ef14f0c1 CH |
378 | return -EPERM; |
379 | ||
380 | if (!value) | |
381 | goto set_acl; | |
382 | ||
5f3a4a28 | 383 | acl = posix_acl_from_xattr(&init_user_ns, value, size); |
ef14f0c1 CH |
384 | if (!acl) { |
385 | /* | |
386 | * acl_set_file(3) may request that we set default ACLs with | |
387 | * zero length -- defend (gracefully) against that here. | |
388 | */ | |
389 | goto out; | |
390 | } | |
391 | if (IS_ERR(acl)) { | |
392 | error = PTR_ERR(acl); | |
393 | goto out; | |
394 | } | |
395 | ||
396 | error = posix_acl_valid(acl); | |
397 | if (error) | |
398 | goto out_release; | |
399 | ||
400 | error = -EINVAL; | |
0a8aa193 | 401 | if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb))) |
ef14f0c1 CH |
402 | goto out_release; |
403 | ||
404 | if (type == ACL_TYPE_ACCESS) { | |
d6952123 | 405 | umode_t mode = inode->i_mode; |
ef14f0c1 CH |
406 | error = posix_acl_equiv_mode(acl, &mode); |
407 | ||
408 | if (error <= 0) { | |
409 | posix_acl_release(acl); | |
410 | acl = NULL; | |
411 | ||
412 | if (error < 0) | |
413 | return error; | |
414 | } | |
415 | ||
416 | error = xfs_set_mode(inode, mode); | |
417 | if (error) | |
418 | goto out_release; | |
419 | } | |
420 | ||
421 | set_acl: | |
422 | error = xfs_set_acl(inode, type, acl); | |
423 | out_release: | |
424 | posix_acl_release(acl); | |
425 | out: | |
426 | return error; | |
427 | } | |
428 | ||
46e58764 | 429 | const struct xattr_handler xfs_xattr_acl_access_handler = { |
431547b3 CH |
430 | .prefix = POSIX_ACL_XATTR_ACCESS, |
431 | .flags = ACL_TYPE_ACCESS, | |
432 | .get = xfs_xattr_acl_get, | |
433 | .set = xfs_xattr_acl_set, | |
434 | }; | |
435 | ||
46e58764 | 436 | const struct xattr_handler xfs_xattr_acl_default_handler = { |
431547b3 CH |
437 | .prefix = POSIX_ACL_XATTR_DEFAULT, |
438 | .flags = ACL_TYPE_DEFAULT, | |
439 | .get = xfs_xattr_acl_get, | |
440 | .set = xfs_xattr_acl_set, | |
ef14f0c1 | 441 | }; |