1 #include <linux/capability.h>
2 #include <linux/fs.h>
3 #include <linux/posix_acl.h>
4 #include "reiserfs.h"
5 #include <linux/errno.h>
6 #include <linux/pagemap.h>
7 #include <linux/xattr.h>
8 #include <linux/slab.h>
9 #include <linux/posix_acl_xattr.h>
10 #include "xattr.h"
11 #include "acl.h"
12 #include <asm/uaccess.h>
13
14 static int reiserfs_set_acl(struct reiserfs_transaction_handle *th,
15 struct inode *inode, int type,
16 struct posix_acl *acl);
17
18 static int
posix_acl_set(struct dentry * dentry,const char * name,const void * value,size_t size,int flags,int type)19 posix_acl_set(struct dentry *dentry, const char *name, const void *value,
20 size_t size, int flags, int type)
21 {
22 struct inode *inode = dentry->d_inode;
23 struct posix_acl *acl;
24 int error, error2;
25 struct reiserfs_transaction_handle th;
26 size_t jcreate_blocks;
27 if (!reiserfs_posixacl(inode->i_sb))
28 return -EOPNOTSUPP;
29 if (!inode_owner_or_capable(inode))
30 return -EPERM;
31
32 if (value) {
33 acl = posix_acl_from_xattr(&init_user_ns, value, size);
34 if (IS_ERR(acl)) {
35 return PTR_ERR(acl);
36 } else if (acl) {
37 error = posix_acl_valid(acl);
38 if (error)
39 goto release_and_out;
40 }
41 } else
42 acl = NULL;
43
44 /* Pessimism: We can't assume that anything from the xattr root up
45 * has been created. */
46
47 jcreate_blocks = reiserfs_xattr_jcreate_nblocks(inode) +
48 reiserfs_xattr_nblocks(inode, size) * 2;
49
50 reiserfs_write_lock(inode->i_sb);
51 error = journal_begin(&th, inode->i_sb, jcreate_blocks);
52 if (error == 0) {
53 error = reiserfs_set_acl(&th, inode, type, acl);
54 error2 = journal_end(&th, inode->i_sb, jcreate_blocks);
55 if (error2)
56 error = error2;
57 }
58 reiserfs_write_unlock(inode->i_sb);
59
60 release_and_out:
61 posix_acl_release(acl);
62 return error;
63 }
64
65 static int
posix_acl_get(struct dentry * dentry,const char * name,void * buffer,size_t size,int type)66 posix_acl_get(struct dentry *dentry, const char *name, void *buffer,
67 size_t size, int type)
68 {
69 struct posix_acl *acl;
70 int error;
71
72 if (!reiserfs_posixacl(dentry->d_sb))
73 return -EOPNOTSUPP;
74
75 acl = reiserfs_get_acl(dentry->d_inode, type);
76 if (IS_ERR(acl))
77 return PTR_ERR(acl);
78 if (acl == NULL)
79 return -ENODATA;
80 error = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
81 posix_acl_release(acl);
82
83 return error;
84 }
85
86 /*
87 * Convert from filesystem to in-memory representation.
88 */
posix_acl_from_disk(const void * value,size_t size)89 static struct posix_acl *posix_acl_from_disk(const void *value, size_t size)
90 {
91 const char *end = (char *)value + size;
92 int n, count;
93 struct posix_acl *acl;
94
95 if (!value)
96 return NULL;
97 if (size < sizeof(reiserfs_acl_header))
98 return ERR_PTR(-EINVAL);
99 if (((reiserfs_acl_header *) value)->a_version !=
100 cpu_to_le32(REISERFS_ACL_VERSION))
101 return ERR_PTR(-EINVAL);
102 value = (char *)value + sizeof(reiserfs_acl_header);
103 count = reiserfs_acl_count(size);
104 if (count < 0)
105 return ERR_PTR(-EINVAL);
106 if (count == 0)
107 return NULL;
108 acl = posix_acl_alloc(count, GFP_NOFS);
109 if (!acl)
110 return ERR_PTR(-ENOMEM);
111 for (n = 0; n < count; n++) {
112 reiserfs_acl_entry *entry = (reiserfs_acl_entry *) value;
113 if ((char *)value + sizeof(reiserfs_acl_entry_short) > end)
114 goto fail;
115 acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
116 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
117 switch (acl->a_entries[n].e_tag) {
118 case ACL_USER_OBJ:
119 case ACL_GROUP_OBJ:
120 case ACL_MASK:
121 case ACL_OTHER:
122 value = (char *)value +
123 sizeof(reiserfs_acl_entry_short);
124 break;
125
126 case ACL_USER:
127 value = (char *)value + sizeof(reiserfs_acl_entry);
128 if ((char *)value > end)
129 goto fail;
130 acl->a_entries[n].e_uid =
131 make_kuid(&init_user_ns,
132 le32_to_cpu(entry->e_id));
133 break;
134 case ACL_GROUP:
135 value = (char *)value + sizeof(reiserfs_acl_entry);
136 if ((char *)value > end)
137 goto fail;
138 acl->a_entries[n].e_gid =
139 make_kgid(&init_user_ns,
140 le32_to_cpu(entry->e_id));
141 break;
142
143 default:
144 goto fail;
145 }
146 }
147 if (value != end)
148 goto fail;
149 return acl;
150
151 fail:
152 posix_acl_release(acl);
153 return ERR_PTR(-EINVAL);
154 }
155
156 /*
157 * Convert from in-memory to filesystem representation.
158 */
posix_acl_to_disk(const struct posix_acl * acl,size_t * size)159 static void *posix_acl_to_disk(const struct posix_acl *acl, size_t * size)
160 {
161 reiserfs_acl_header *ext_acl;
162 char *e;
163 int n;
164
165 *size = reiserfs_acl_size(acl->a_count);
166 ext_acl = kmalloc(sizeof(reiserfs_acl_header) +
167 acl->a_count *
168 sizeof(reiserfs_acl_entry),
169 GFP_NOFS);
170 if (!ext_acl)
171 return ERR_PTR(-ENOMEM);
172 ext_acl->a_version = cpu_to_le32(REISERFS_ACL_VERSION);
173 e = (char *)ext_acl + sizeof(reiserfs_acl_header);
174 for (n = 0; n < acl->a_count; n++) {
175 const struct posix_acl_entry *acl_e = &acl->a_entries[n];
176 reiserfs_acl_entry *entry = (reiserfs_acl_entry *) e;
177 entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
178 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
179 switch (acl->a_entries[n].e_tag) {
180 case ACL_USER:
181 entry->e_id = cpu_to_le32(
182 from_kuid(&init_user_ns, acl_e->e_uid));
183 e += sizeof(reiserfs_acl_entry);
184 break;
185 case ACL_GROUP:
186 entry->e_id = cpu_to_le32(
187 from_kgid(&init_user_ns, acl_e->e_gid));
188 e += sizeof(reiserfs_acl_entry);
189 break;
190
191 case ACL_USER_OBJ:
192 case ACL_GROUP_OBJ:
193 case ACL_MASK:
194 case ACL_OTHER:
195 e += sizeof(reiserfs_acl_entry_short);
196 break;
197
198 default:
199 goto fail;
200 }
201 }
202 return (char *)ext_acl;
203
204 fail:
205 kfree(ext_acl);
206 return ERR_PTR(-EINVAL);
207 }
208
209 /*
210 * Inode operation get_posix_acl().
211 *
212 * inode->i_mutex: down
213 * BKL held [before 2.5.x]
214 */
reiserfs_get_acl(struct inode * inode,int type)215 struct posix_acl *reiserfs_get_acl(struct inode *inode, int type)
216 {
217 char *name, *value;
218 struct posix_acl *acl;
219 int size;
220 int retval;
221
222 acl = get_cached_acl(inode, type);
223 if (acl != ACL_NOT_CACHED)
224 return acl;
225
226 switch (type) {
227 case ACL_TYPE_ACCESS:
228 name = POSIX_ACL_XATTR_ACCESS;
229 break;
230 case ACL_TYPE_DEFAULT:
231 name = POSIX_ACL_XATTR_DEFAULT;
232 break;
233 default:
234 BUG();
235 }
236
237 size = reiserfs_xattr_get(inode, name, NULL, 0);
238 if (size < 0) {
239 if (size == -ENODATA || size == -ENOSYS) {
240 set_cached_acl(inode, type, NULL);
241 return NULL;
242 }
243 return ERR_PTR(size);
244 }
245
246 value = kmalloc(size, GFP_NOFS);
247 if (!value)
248 return ERR_PTR(-ENOMEM);
249
250 retval = reiserfs_xattr_get(inode, name, value, size);
251 if (retval == -ENODATA || retval == -ENOSYS) {
252 /* This shouldn't actually happen as it should have
253 been caught above.. but just in case */
254 acl = NULL;
255 } else if (retval < 0) {
256 acl = ERR_PTR(retval);
257 } else {
258 acl = posix_acl_from_disk(value, retval);
259 }
260 if (!IS_ERR(acl))
261 set_cached_acl(inode, type, acl);
262
263 kfree(value);
264 return acl;
265 }
266
267 /*
268 * Inode operation set_posix_acl().
269 *
270 * inode->i_mutex: down
271 * BKL held [before 2.5.x]
272 */
273 static int
reiserfs_set_acl(struct reiserfs_transaction_handle * th,struct inode * inode,int type,struct posix_acl * acl)274 reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode,
275 int type, struct posix_acl *acl)
276 {
277 char *name;
278 void *value = NULL;
279 size_t size = 0;
280 int error;
281
282 if (S_ISLNK(inode->i_mode))
283 return -EOPNOTSUPP;
284
285 switch (type) {
286 case ACL_TYPE_ACCESS:
287 name = POSIX_ACL_XATTR_ACCESS;
288 if (acl) {
289 error = posix_acl_update_mode(inode, &inode->i_mode, &acl);
290 if (error)
291 return error;
292 }
293 break;
294 case ACL_TYPE_DEFAULT:
295 name = POSIX_ACL_XATTR_DEFAULT;
296 if (!S_ISDIR(inode->i_mode))
297 return acl ? -EACCES : 0;
298 break;
299 default:
300 return -EINVAL;
301 }
302
303 if (acl) {
304 value = posix_acl_to_disk(acl, &size);
305 if (IS_ERR(value))
306 return (int)PTR_ERR(value);
307 }
308
309 error = reiserfs_xattr_set_handle(th, inode, name, value, size, 0);
310
311 /*
312 * Ensure that the inode gets dirtied if we're only using
313 * the mode bits and an old ACL didn't exist. We don't need
314 * to check if the inode is hashed here since we won't get
315 * called by reiserfs_inherit_default_acl().
316 */
317 if (error == -ENODATA) {
318 error = 0;
319 if (type == ACL_TYPE_ACCESS) {
320 inode->i_ctime = CURRENT_TIME_SEC;
321 mark_inode_dirty(inode);
322 }
323 }
324
325 kfree(value);
326
327 if (!error)
328 set_cached_acl(inode, type, acl);
329
330 return error;
331 }
332
333 /* dir->i_mutex: locked,
334 * inode is new and not released into the wild yet */
335 int
reiserfs_inherit_default_acl(struct reiserfs_transaction_handle * th,struct inode * dir,struct dentry * dentry,struct inode * inode)336 reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th,
337 struct inode *dir, struct dentry *dentry,
338 struct inode *inode)
339 {
340 struct posix_acl *acl;
341 int err = 0;
342
343 /* ACLs only get applied to files and directories */
344 if (S_ISLNK(inode->i_mode))
345 return 0;
346
347 /* ACLs can only be used on "new" objects, so if it's an old object
348 * there is nothing to inherit from */
349 if (get_inode_sd_version(dir) == STAT_DATA_V1)
350 goto apply_umask;
351
352 /* Don't apply ACLs to objects in the .reiserfs_priv tree.. This
353 * would be useless since permissions are ignored, and a pain because
354 * it introduces locking cycles */
355 if (IS_PRIVATE(dir)) {
356 inode->i_flags |= S_PRIVATE;
357 goto apply_umask;
358 }
359
360 acl = reiserfs_get_acl(dir, ACL_TYPE_DEFAULT);
361 if (IS_ERR(acl))
362 return PTR_ERR(acl);
363
364 if (acl) {
365 /* Copy the default ACL to the default ACL of a new directory */
366 if (S_ISDIR(inode->i_mode)) {
367 err = reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT,
368 acl);
369 if (err)
370 goto cleanup;
371 }
372
373 /* Now we reconcile the new ACL and the mode,
374 potentially modifying both */
375 err = posix_acl_create(&acl, GFP_NOFS, &inode->i_mode);
376 if (err < 0)
377 return err;
378
379 /* If we need an ACL.. */
380 if (err > 0)
381 err = reiserfs_set_acl(th, inode, ACL_TYPE_ACCESS, acl);
382 cleanup:
383 posix_acl_release(acl);
384 } else {
385 apply_umask:
386 /* no ACL, apply umask */
387 inode->i_mode &= ~current_umask();
388 }
389
390 return err;
391 }
392
393 /* This is used to cache the default acl before a new object is created.
394 * The biggest reason for this is to get an idea of how many blocks will
395 * actually be required for the create operation if we must inherit an ACL.
396 * An ACL write can add up to 3 object creations and an additional file write
397 * so we'd prefer not to reserve that many blocks in the journal if we can.
398 * It also has the advantage of not loading the ACL with a transaction open,
399 * this may seem silly, but if the owner of the directory is doing the
400 * creation, the ACL may not be loaded since the permissions wouldn't require
401 * it.
402 * We return the number of blocks required for the transaction.
403 */
reiserfs_cache_default_acl(struct inode * inode)404 int reiserfs_cache_default_acl(struct inode *inode)
405 {
406 struct posix_acl *acl;
407 int nblocks = 0;
408
409 if (IS_PRIVATE(inode))
410 return 0;
411
412 acl = reiserfs_get_acl(inode, ACL_TYPE_DEFAULT);
413
414 if (acl && !IS_ERR(acl)) {
415 int size = reiserfs_acl_size(acl->a_count);
416
417 /* Other xattrs can be created during inode creation. We don't
418 * want to claim too many blocks, so we check to see if we
419 * we need to create the tree to the xattrs, and then we
420 * just want two files. */
421 nblocks = reiserfs_xattr_jcreate_nblocks(inode);
422 nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb);
423
424 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
425
426 /* We need to account for writes + bitmaps for two files */
427 nblocks += reiserfs_xattr_nblocks(inode, size) * 4;
428 posix_acl_release(acl);
429 }
430
431 return nblocks;
432 }
433
reiserfs_acl_chmod(struct inode * inode)434 int reiserfs_acl_chmod(struct inode *inode)
435 {
436 struct reiserfs_transaction_handle th;
437 struct posix_acl *acl;
438 size_t size;
439 int depth;
440 int error;
441
442 if (IS_PRIVATE(inode))
443 return 0;
444
445 if (S_ISLNK(inode->i_mode))
446 return -EOPNOTSUPP;
447
448 if (get_inode_sd_version(inode) == STAT_DATA_V1 ||
449 !reiserfs_posixacl(inode->i_sb)) {
450 return 0;
451 }
452
453 reiserfs_write_unlock(inode->i_sb);
454 acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
455 reiserfs_write_lock(inode->i_sb);
456 if (!acl)
457 return 0;
458 if (IS_ERR(acl))
459 return PTR_ERR(acl);
460 error = posix_acl_chmod(&acl, GFP_NOFS, inode->i_mode);
461 if (error)
462 return error;
463
464 size = reiserfs_xattr_nblocks(inode, reiserfs_acl_size(acl->a_count));
465 depth = reiserfs_write_lock_once(inode->i_sb);
466 error = journal_begin(&th, inode->i_sb, size * 2);
467 if (!error) {
468 int error2;
469 error = reiserfs_set_acl(&th, inode, ACL_TYPE_ACCESS, acl);
470 error2 = journal_end(&th, inode->i_sb, size * 2);
471 if (error2)
472 error = error2;
473 }
474 reiserfs_write_unlock_once(inode->i_sb, depth);
475 posix_acl_release(acl);
476 return error;
477 }
478
posix_acl_access_list(struct dentry * dentry,char * list,size_t list_size,const char * name,size_t name_len,int type)479 static size_t posix_acl_access_list(struct dentry *dentry, char *list,
480 size_t list_size, const char *name,
481 size_t name_len, int type)
482 {
483 const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
484 if (!reiserfs_posixacl(dentry->d_sb))
485 return 0;
486 if (list && size <= list_size)
487 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
488 return size;
489 }
490
491 const struct xattr_handler reiserfs_posix_acl_access_handler = {
492 .prefix = POSIX_ACL_XATTR_ACCESS,
493 .flags = ACL_TYPE_ACCESS,
494 .get = posix_acl_get,
495 .set = posix_acl_set,
496 .list = posix_acl_access_list,
497 };
498
posix_acl_default_list(struct dentry * dentry,char * list,size_t list_size,const char * name,size_t name_len,int type)499 static size_t posix_acl_default_list(struct dentry *dentry, char *list,
500 size_t list_size, const char *name,
501 size_t name_len, int type)
502 {
503 const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
504 if (!reiserfs_posixacl(dentry->d_sb))
505 return 0;
506 if (list && size <= list_size)
507 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
508 return size;
509 }
510
511 const struct xattr_handler reiserfs_posix_acl_default_handler = {
512 .prefix = POSIX_ACL_XATTR_DEFAULT,
513 .flags = ACL_TYPE_DEFAULT,
514 .get = posix_acl_get,
515 .set = posix_acl_set,
516 .list = posix_acl_default_list,
517 };
518