Merge branch 'akpm' (fixes from Andrew)
[linux-2.6/cjktty.git] / fs / reiserfs / xattr_acl.c
blobd7c01ef64edab42ed59d022a2cf36f917e1935c0
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>
14 static int reiserfs_set_acl(struct reiserfs_transaction_handle *th,
15 struct inode *inode, int type,
16 struct posix_acl *acl);
18 static int
19 posix_acl_set(struct dentry *dentry, const char *name, const void *value,
20 size_t size, int flags, int type)
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;
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;
41 } else
42 acl = NULL;
44 /* Pessimism: We can't assume that anything from the xattr root up
45 * has been created. */
47 jcreate_blocks = reiserfs_xattr_jcreate_nblocks(inode) +
48 reiserfs_xattr_nblocks(inode, size) * 2;
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;
58 reiserfs_write_unlock(inode->i_sb);
60 release_and_out:
61 posix_acl_release(acl);
62 return error;
65 static int
66 posix_acl_get(struct dentry *dentry, const char *name, void *buffer,
67 size_t size, int type)
69 struct posix_acl *acl;
70 int error;
72 if (!reiserfs_posixacl(dentry->d_sb))
73 return -EOPNOTSUPP;
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);
83 return error;
87 * Convert from filesystem to in-memory representation.
89 static struct posix_acl *posix_acl_from_disk(const void *value, size_t size)
91 const char *end = (char *)value + size;
92 int n, count;
93 struct posix_acl *acl;
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;
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;
143 default:
144 goto fail;
147 if (value != end)
148 goto fail;
149 return acl;
151 fail:
152 posix_acl_release(acl);
153 return ERR_PTR(-EINVAL);
157 * Convert from in-memory to filesystem representation.
159 static void *posix_acl_to_disk(const struct posix_acl *acl, size_t * size)
161 reiserfs_acl_header *ext_acl;
162 char *e;
163 int n;
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;
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;
198 default:
199 goto fail;
202 return (char *)ext_acl;
204 fail:
205 kfree(ext_acl);
206 return ERR_PTR(-EINVAL);
210 * Inode operation get_posix_acl().
212 * inode->i_mutex: down
213 * BKL held [before 2.5.x]
215 struct posix_acl *reiserfs_get_acl(struct inode *inode, int type)
217 char *name, *value;
218 struct posix_acl *acl;
219 int size;
220 int retval;
222 acl = get_cached_acl(inode, type);
223 if (acl != ACL_NOT_CACHED)
224 return acl;
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();
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;
243 return ERR_PTR(size);
246 value = kmalloc(size, GFP_NOFS);
247 if (!value)
248 return ERR_PTR(-ENOMEM);
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);
260 if (!IS_ERR(acl))
261 set_cached_acl(inode, type, acl);
263 kfree(value);
264 return acl;
268 * Inode operation set_posix_acl().
270 * inode->i_mutex: down
271 * BKL held [before 2.5.x]
273 static int
274 reiserfs_set_acl(struct reiserfs_transaction_handle *th, struct inode *inode,
275 int type, struct posix_acl *acl)
277 char *name;
278 void *value = NULL;
279 size_t size = 0;
280 int error;
282 if (S_ISLNK(inode->i_mode))
283 return -EOPNOTSUPP;
285 switch (type) {
286 case ACL_TYPE_ACCESS:
287 name = POSIX_ACL_XATTR_ACCESS;
288 if (acl) {
289 error = posix_acl_equiv_mode(acl, &inode->i_mode);
290 if (error < 0)
291 return error;
292 else {
293 if (error == 0)
294 acl = NULL;
297 break;
298 case ACL_TYPE_DEFAULT:
299 name = POSIX_ACL_XATTR_DEFAULT;
300 if (!S_ISDIR(inode->i_mode))
301 return acl ? -EACCES : 0;
302 break;
303 default:
304 return -EINVAL;
307 if (acl) {
308 value = posix_acl_to_disk(acl, &size);
309 if (IS_ERR(value))
310 return (int)PTR_ERR(value);
313 error = reiserfs_xattr_set_handle(th, inode, name, value, size, 0);
316 * Ensure that the inode gets dirtied if we're only using
317 * the mode bits and an old ACL didn't exist. We don't need
318 * to check if the inode is hashed here since we won't get
319 * called by reiserfs_inherit_default_acl().
321 if (error == -ENODATA) {
322 error = 0;
323 if (type == ACL_TYPE_ACCESS) {
324 inode->i_ctime = CURRENT_TIME_SEC;
325 mark_inode_dirty(inode);
329 kfree(value);
331 if (!error)
332 set_cached_acl(inode, type, acl);
334 return error;
337 /* dir->i_mutex: locked,
338 * inode is new and not released into the wild yet */
340 reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th,
341 struct inode *dir, struct dentry *dentry,
342 struct inode *inode)
344 struct posix_acl *acl;
345 int err = 0;
347 /* ACLs only get applied to files and directories */
348 if (S_ISLNK(inode->i_mode))
349 return 0;
351 /* ACLs can only be used on "new" objects, so if it's an old object
352 * there is nothing to inherit from */
353 if (get_inode_sd_version(dir) == STAT_DATA_V1)
354 goto apply_umask;
356 /* Don't apply ACLs to objects in the .reiserfs_priv tree.. This
357 * would be useless since permissions are ignored, and a pain because
358 * it introduces locking cycles */
359 if (IS_PRIVATE(dir)) {
360 inode->i_flags |= S_PRIVATE;
361 goto apply_umask;
364 acl = reiserfs_get_acl(dir, ACL_TYPE_DEFAULT);
365 if (IS_ERR(acl))
366 return PTR_ERR(acl);
368 if (acl) {
369 /* Copy the default ACL to the default ACL of a new directory */
370 if (S_ISDIR(inode->i_mode)) {
371 err = reiserfs_set_acl(th, inode, ACL_TYPE_DEFAULT,
372 acl);
373 if (err)
374 goto cleanup;
377 /* Now we reconcile the new ACL and the mode,
378 potentially modifying both */
379 err = posix_acl_create(&acl, GFP_NOFS, &inode->i_mode);
380 if (err < 0)
381 return err;
383 /* If we need an ACL.. */
384 if (err > 0)
385 err = reiserfs_set_acl(th, inode, ACL_TYPE_ACCESS, acl);
386 cleanup:
387 posix_acl_release(acl);
388 } else {
389 apply_umask:
390 /* no ACL, apply umask */
391 inode->i_mode &= ~current_umask();
394 return err;
397 /* This is used to cache the default acl before a new object is created.
398 * The biggest reason for this is to get an idea of how many blocks will
399 * actually be required for the create operation if we must inherit an ACL.
400 * An ACL write can add up to 3 object creations and an additional file write
401 * so we'd prefer not to reserve that many blocks in the journal if we can.
402 * It also has the advantage of not loading the ACL with a transaction open,
403 * this may seem silly, but if the owner of the directory is doing the
404 * creation, the ACL may not be loaded since the permissions wouldn't require
405 * it.
406 * We return the number of blocks required for the transaction.
408 int reiserfs_cache_default_acl(struct inode *inode)
410 struct posix_acl *acl;
411 int nblocks = 0;
413 if (IS_PRIVATE(inode))
414 return 0;
416 acl = reiserfs_get_acl(inode, ACL_TYPE_DEFAULT);
418 if (acl && !IS_ERR(acl)) {
419 int size = reiserfs_acl_size(acl->a_count);
421 /* Other xattrs can be created during inode creation. We don't
422 * want to claim too many blocks, so we check to see if we
423 * we need to create the tree to the xattrs, and then we
424 * just want two files. */
425 nblocks = reiserfs_xattr_jcreate_nblocks(inode);
426 nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb);
428 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
430 /* We need to account for writes + bitmaps for two files */
431 nblocks += reiserfs_xattr_nblocks(inode, size) * 4;
432 posix_acl_release(acl);
435 return nblocks;
438 int reiserfs_acl_chmod(struct inode *inode)
440 struct reiserfs_transaction_handle th;
441 struct posix_acl *acl;
442 size_t size;
443 int depth;
444 int error;
446 if (S_ISLNK(inode->i_mode))
447 return -EOPNOTSUPP;
449 if (get_inode_sd_version(inode) == STAT_DATA_V1 ||
450 !reiserfs_posixacl(inode->i_sb)) {
451 return 0;
454 reiserfs_write_unlock(inode->i_sb);
455 acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS);
456 reiserfs_write_lock(inode->i_sb);
457 if (!acl)
458 return 0;
459 if (IS_ERR(acl))
460 return PTR_ERR(acl);
461 error = posix_acl_chmod(&acl, GFP_NOFS, inode->i_mode);
462 if (error)
463 return error;
465 size = reiserfs_xattr_nblocks(inode, reiserfs_acl_size(acl->a_count));
466 depth = reiserfs_write_lock_once(inode->i_sb);
467 error = journal_begin(&th, inode->i_sb, size * 2);
468 if (!error) {
469 int error2;
470 error = reiserfs_set_acl(&th, inode, ACL_TYPE_ACCESS, acl);
471 error2 = journal_end(&th, inode->i_sb, size * 2);
472 if (error2)
473 error = error2;
475 reiserfs_write_unlock_once(inode->i_sb, depth);
476 posix_acl_release(acl);
477 return error;
480 static size_t posix_acl_access_list(struct dentry *dentry, char *list,
481 size_t list_size, const char *name,
482 size_t name_len, int type)
484 const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
485 if (!reiserfs_posixacl(dentry->d_sb))
486 return 0;
487 if (list && size <= list_size)
488 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
489 return size;
492 const struct xattr_handler reiserfs_posix_acl_access_handler = {
493 .prefix = POSIX_ACL_XATTR_ACCESS,
494 .flags = ACL_TYPE_ACCESS,
495 .get = posix_acl_get,
496 .set = posix_acl_set,
497 .list = posix_acl_access_list,
500 static size_t posix_acl_default_list(struct dentry *dentry, char *list,
501 size_t list_size, const char *name,
502 size_t name_len, int type)
504 const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
505 if (!reiserfs_posixacl(dentry->d_sb))
506 return 0;
507 if (list && size <= list_size)
508 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
509 return size;
512 const struct xattr_handler reiserfs_posix_acl_default_handler = {
513 .prefix = POSIX_ACL_XATTR_DEFAULT,
514 .flags = ACL_TYPE_DEFAULT,
515 .get = posix_acl_get,
516 .set = posix_acl_set,
517 .list = posix_acl_default_list,