blob: b2771862fd3df79fbb721b3c5c93865680a8e145 [file] [log] [blame]
Christoph Hellwigef14f0c2009-06-10 17:07:47 +02001/*
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"
Christoph Hellwig0b1b2132009-12-14 23:14:59 +000024#include "xfs_trace.h"
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090025#include <linux/slab.h>
Christoph Hellwigef14f0c2009-06-10 17:07:47 +020026#include <linux/xattr.h>
27#include <linux/posix_acl_xattr.h>
28
29
Christoph Hellwigef14f0c2009-06-10 17:07:47 +020030/*
31 * Locking scheme:
32 * - all ACL updates are protected by inode->i_mutex, which is taken before
33 * calling into this file.
Christoph Hellwigef14f0c2009-06-10 17:07:47 +020034 */
35
36STATIC struct posix_acl *
37xfs_acl_from_disk(struct xfs_acl *aclp)
38{
39 struct posix_acl_entry *acl_e;
40 struct posix_acl *acl;
41 struct xfs_acl_entry *ace;
42 int count, i;
43
44 count = be32_to_cpu(aclp->acl_cnt);
45
46 acl = posix_acl_alloc(count, GFP_KERNEL);
47 if (!acl)
48 return ERR_PTR(-ENOMEM);
49
50 for (i = 0; i < count; i++) {
51 acl_e = &acl->a_entries[i];
52 ace = &aclp->acl_entry[i];
53
54 /*
55 * The tag is 32 bits on disk and 16 bits in core.
56 *
57 * Because every access to it goes through the core
58 * format first this is not a problem.
59 */
60 acl_e->e_tag = be32_to_cpu(ace->ae_tag);
61 acl_e->e_perm = be16_to_cpu(ace->ae_perm);
62
63 switch (acl_e->e_tag) {
64 case ACL_USER:
65 case ACL_GROUP:
66 acl_e->e_id = be32_to_cpu(ace->ae_id);
67 break;
68 case ACL_USER_OBJ:
69 case ACL_GROUP_OBJ:
70 case ACL_MASK:
71 case ACL_OTHER:
72 acl_e->e_id = ACL_UNDEFINED_ID;
73 break;
74 default:
75 goto fail;
76 }
77 }
78 return acl;
79
80fail:
81 posix_acl_release(acl);
82 return ERR_PTR(-EINVAL);
83}
84
85STATIC void
86xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
87{
88 const struct posix_acl_entry *acl_e;
89 struct xfs_acl_entry *ace;
90 int i;
91
92 aclp->acl_cnt = cpu_to_be32(acl->a_count);
93 for (i = 0; i < acl->a_count; i++) {
94 ace = &aclp->acl_entry[i];
95 acl_e = &acl->a_entries[i];
96
97 ace->ae_tag = cpu_to_be32(acl_e->e_tag);
98 ace->ae_id = cpu_to_be32(acl_e->e_id);
99 ace->ae_perm = cpu_to_be16(acl_e->e_perm);
100 }
101}
102
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200103struct posix_acl *
104xfs_get_acl(struct inode *inode, int type)
105{
106 struct xfs_inode *ip = XFS_I(inode);
Al Viro1cbd20d2009-06-09 13:29:39 -0400107 struct posix_acl *acl;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200108 struct xfs_acl *xfs_acl;
109 int len = sizeof(struct xfs_acl);
Dave Chinnera9273ca2010-01-20 10:47:48 +1100110 unsigned char *ea_name;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200111 int error;
112
Al Viro1cbd20d2009-06-09 13:29:39 -0400113 acl = get_cached_acl(inode, type);
114 if (acl != ACL_NOT_CACHED)
115 return acl;
116
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200117 switch (type) {
118 case ACL_TYPE_ACCESS:
119 ea_name = SGI_ACL_FILE;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200120 break;
121 case ACL_TYPE_DEFAULT:
122 ea_name = SGI_ACL_DEFAULT;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200123 break;
124 default:
Al Viro1cbd20d2009-06-09 13:29:39 -0400125 BUG();
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200126 }
127
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200128 /*
129 * If we have a cached ACLs value just return it, not need to
130 * go out to the disk.
131 */
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200132
133 xfs_acl = kzalloc(sizeof(struct xfs_acl), GFP_KERNEL);
134 if (!xfs_acl)
135 return ERR_PTR(-ENOMEM);
136
Dave Chinnera9273ca2010-01-20 10:47:48 +1100137 error = -xfs_attr_get(ip, ea_name, (unsigned char *)xfs_acl,
138 &len, ATTR_ROOT);
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200139 if (error) {
140 /*
141 * If the attribute doesn't exist make sure we have a negative
142 * cache entry, for any other error assume it is transient and
Al Viro1cbd20d2009-06-09 13:29:39 -0400143 * leave the cache entry as ACL_NOT_CACHED.
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200144 */
145 if (error == -ENOATTR) {
146 acl = NULL;
147 goto out_update_cache;
148 }
149 goto out;
150 }
151
152 acl = xfs_acl_from_disk(xfs_acl);
153 if (IS_ERR(acl))
154 goto out;
155
156 out_update_cache:
Al Viro1cbd20d2009-06-09 13:29:39 -0400157 set_cached_acl(inode, type, acl);
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200158 out:
159 kfree(xfs_acl);
160 return acl;
161}
162
163STATIC int
164xfs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
165{
166 struct xfs_inode *ip = XFS_I(inode);
Dave Chinnera9273ca2010-01-20 10:47:48 +1100167 unsigned char *ea_name;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200168 int error;
169
170 if (S_ISLNK(inode->i_mode))
171 return -EOPNOTSUPP;
172
173 switch (type) {
174 case ACL_TYPE_ACCESS:
175 ea_name = SGI_ACL_FILE;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200176 break;
177 case ACL_TYPE_DEFAULT:
178 if (!S_ISDIR(inode->i_mode))
179 return acl ? -EACCES : 0;
180 ea_name = SGI_ACL_DEFAULT;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200181 break;
182 default:
183 return -EINVAL;
184 }
185
186 if (acl) {
187 struct xfs_acl *xfs_acl;
188 int len;
189
190 xfs_acl = kzalloc(sizeof(struct xfs_acl), GFP_KERNEL);
191 if (!xfs_acl)
192 return -ENOMEM;
193
194 xfs_acl_to_disk(xfs_acl, acl);
195 len = sizeof(struct xfs_acl) -
196 (sizeof(struct xfs_acl_entry) *
197 (XFS_ACL_MAX_ENTRIES - acl->a_count));
198
Dave Chinnera9273ca2010-01-20 10:47:48 +1100199 error = -xfs_attr_set(ip, ea_name, (unsigned char *)xfs_acl,
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200200 len, ATTR_ROOT);
201
202 kfree(xfs_acl);
203 } else {
204 /*
205 * A NULL ACL argument means we want to remove the ACL.
206 */
207 error = -xfs_attr_remove(ip, ea_name, ATTR_ROOT);
208
209 /*
210 * If the attribute didn't exist to start with that's fine.
211 */
212 if (error == -ENOATTR)
213 error = 0;
214 }
215
216 if (!error)
Al Viro1cbd20d2009-06-09 13:29:39 -0400217 set_cached_acl(inode, type, acl);
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200218 return error;
219}
220
221int
222xfs_check_acl(struct inode *inode, int mask)
223{
224 struct xfs_inode *ip = XFS_I(inode);
225 struct posix_acl *acl;
226 int error = -EAGAIN;
227
Christoph Hellwigcca28fb2010-06-24 11:57:09 +1000228 trace_xfs_check_acl(ip);
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200229
230 /*
231 * If there is no attribute fork no ACL exists on this inode and
232 * we can skip the whole exercise.
233 */
234 if (!XFS_IFORK_Q(ip))
235 return -EAGAIN;
236
237 acl = xfs_get_acl(inode, ACL_TYPE_ACCESS);
238 if (IS_ERR(acl))
239 return PTR_ERR(acl);
240 if (acl) {
241 error = posix_acl_permission(inode, acl, mask);
242 posix_acl_release(acl);
243 }
244
245 return error;
246}
247
248static int
249xfs_set_mode(struct inode *inode, mode_t mode)
250{
251 int error = 0;
252
253 if (mode != inode->i_mode) {
254 struct iattr iattr;
255
Christoph Hellwigd6d59ba2009-12-23 16:09:13 +0000256 iattr.ia_valid = ATTR_MODE | ATTR_CTIME;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200257 iattr.ia_mode = mode;
Christoph Hellwigd6d59ba2009-12-23 16:09:13 +0000258 iattr.ia_ctime = current_fs_time(inode->i_sb);
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200259
260 error = -xfs_setattr(XFS_I(inode), &iattr, XFS_ATTR_NOACL);
261 }
262
263 return error;
264}
265
266static int
Dave Chinnera9273ca2010-01-20 10:47:48 +1100267xfs_acl_exists(struct inode *inode, unsigned char *name)
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200268{
269 int len = sizeof(struct xfs_acl);
270
271 return (xfs_attr_get(XFS_I(inode), name, NULL, &len,
272 ATTR_ROOT|ATTR_KERNOVAL) == 0);
273}
274
275int
276posix_acl_access_exists(struct inode *inode)
277{
278 return xfs_acl_exists(inode, SGI_ACL_FILE);
279}
280
281int
282posix_acl_default_exists(struct inode *inode)
283{
284 if (!S_ISDIR(inode->i_mode))
285 return 0;
286 return xfs_acl_exists(inode, SGI_ACL_DEFAULT);
287}
288
289/*
290 * No need for i_mutex because the inode is not yet exposed to the VFS.
291 */
292int
293xfs_inherit_acl(struct inode *inode, struct posix_acl *default_acl)
294{
295 struct posix_acl *clone;
296 mode_t mode;
297 int error = 0, inherit = 0;
298
299 if (S_ISDIR(inode->i_mode)) {
300 error = xfs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl);
301 if (error)
302 return error;
303 }
304
305 clone = posix_acl_clone(default_acl, GFP_KERNEL);
306 if (!clone)
307 return -ENOMEM;
308
309 mode = inode->i_mode;
310 error = posix_acl_create_masq(clone, &mode);
311 if (error < 0)
312 goto out_release_clone;
313
314 /*
315 * If posix_acl_create_masq returns a positive value we need to
316 * inherit a permission that can't be represented using the Unix
317 * mode bits and we actually need to set an ACL.
318 */
319 if (error > 0)
320 inherit = 1;
321
322 error = xfs_set_mode(inode, mode);
323 if (error)
324 goto out_release_clone;
325
326 if (inherit)
327 error = xfs_set_acl(inode, ACL_TYPE_ACCESS, clone);
328
329 out_release_clone:
330 posix_acl_release(clone);
331 return error;
332}
333
334int
335xfs_acl_chmod(struct inode *inode)
336{
337 struct posix_acl *acl, *clone;
338 int error;
339
340 if (S_ISLNK(inode->i_mode))
341 return -EOPNOTSUPP;
342
343 acl = xfs_get_acl(inode, ACL_TYPE_ACCESS);
344 if (IS_ERR(acl) || !acl)
345 return PTR_ERR(acl);
346
347 clone = posix_acl_clone(acl, GFP_KERNEL);
348 posix_acl_release(acl);
349 if (!clone)
350 return -ENOMEM;
351
352 error = posix_acl_chmod_masq(clone, inode->i_mode);
353 if (!error)
354 error = xfs_set_acl(inode, ACL_TYPE_ACCESS, clone);
355
356 posix_acl_release(clone);
357 return error;
358}
359
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200360static int
Christoph Hellwig431547b2009-11-13 09:52:56 +0000361xfs_xattr_acl_get(struct dentry *dentry, const char *name,
362 void *value, size_t size, int type)
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200363{
364 struct posix_acl *acl;
Christoph Hellwig431547b2009-11-13 09:52:56 +0000365 int error;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200366
Christoph Hellwig431547b2009-11-13 09:52:56 +0000367 acl = xfs_get_acl(dentry->d_inode, type);
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200368 if (IS_ERR(acl))
369 return PTR_ERR(acl);
370 if (acl == NULL)
371 return -ENODATA;
372
373 error = posix_acl_to_xattr(acl, value, size);
374 posix_acl_release(acl);
375
376 return error;
377}
378
379static int
Christoph Hellwig431547b2009-11-13 09:52:56 +0000380xfs_xattr_acl_set(struct dentry *dentry, const char *name,
381 const void *value, size_t size, int flags, int type)
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200382{
Christoph Hellwig431547b2009-11-13 09:52:56 +0000383 struct inode *inode = dentry->d_inode;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200384 struct posix_acl *acl = NULL;
Christoph Hellwig431547b2009-11-13 09:52:56 +0000385 int error = 0;
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200386
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200387 if (flags & XATTR_CREATE)
388 return -EINVAL;
389 if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
390 return value ? -EACCES : 0;
391 if ((current_fsuid() != inode->i_uid) && !capable(CAP_FOWNER))
392 return -EPERM;
393
394 if (!value)
395 goto set_acl;
396
397 acl = posix_acl_from_xattr(value, size);
398 if (!acl) {
399 /*
400 * acl_set_file(3) may request that we set default ACLs with
401 * zero length -- defend (gracefully) against that here.
402 */
403 goto out;
404 }
405 if (IS_ERR(acl)) {
406 error = PTR_ERR(acl);
407 goto out;
408 }
409
410 error = posix_acl_valid(acl);
411 if (error)
412 goto out_release;
413
414 error = -EINVAL;
415 if (acl->a_count > XFS_ACL_MAX_ENTRIES)
416 goto out_release;
417
418 if (type == ACL_TYPE_ACCESS) {
419 mode_t mode = inode->i_mode;
420 error = posix_acl_equiv_mode(acl, &mode);
421
422 if (error <= 0) {
423 posix_acl_release(acl);
424 acl = NULL;
425
426 if (error < 0)
427 return error;
428 }
429
430 error = xfs_set_mode(inode, mode);
431 if (error)
432 goto out_release;
433 }
434
435 set_acl:
436 error = xfs_set_acl(inode, type, acl);
437 out_release:
438 posix_acl_release(acl);
439 out:
440 return error;
441}
442
Stephen Hemminger46e58762010-05-13 17:53:20 -0700443const struct xattr_handler xfs_xattr_acl_access_handler = {
Christoph Hellwig431547b2009-11-13 09:52:56 +0000444 .prefix = POSIX_ACL_XATTR_ACCESS,
445 .flags = ACL_TYPE_ACCESS,
446 .get = xfs_xattr_acl_get,
447 .set = xfs_xattr_acl_set,
448};
449
Stephen Hemminger46e58762010-05-13 17:53:20 -0700450const struct xattr_handler xfs_xattr_acl_default_handler = {
Christoph Hellwig431547b2009-11-13 09:52:56 +0000451 .prefix = POSIX_ACL_XATTR_DEFAULT,
452 .flags = ACL_TYPE_DEFAULT,
453 .get = xfs_xattr_acl_get,
454 .set = xfs_xattr_acl_set,
Christoph Hellwigef14f0c2009-06-10 17:07:47 +0200455};