4 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
7 #include <linux/init.h>
8 #include <linux/sched.h>
9 #include <linux/slab.h>
10 #include <linux/capability.h>
12 #include <linux/ext3_jbd.h>
13 #include <linux/ext3_fs.h>
18 * Convert from filesystem to in-memory representation.
20 static struct posix_acl *
21 ext3_acl_from_disk(const void *value, size_t size)
23 const char *end = (char *)value + size;
25 struct posix_acl *acl;
29 if (size < sizeof(ext3_acl_header))
30 return ERR_PTR(-EINVAL);
31 if (((ext3_acl_header *)value)->a_version !=
32 cpu_to_le32(EXT3_ACL_VERSION))
33 return ERR_PTR(-EINVAL);
34 value = (char *)value + sizeof(ext3_acl_header);
35 count = ext3_acl_count(size);
37 return ERR_PTR(-EINVAL);
40 acl = posix_acl_alloc(count, GFP_NOFS);
42 return ERR_PTR(-ENOMEM);
43 for (n=0; n < count; n++) {
44 ext3_acl_entry *entry =
45 (ext3_acl_entry *)value;
46 if ((char *)value + sizeof(ext3_acl_entry_short) > end)
48 acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
49 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
50 switch(acl->a_entries[n].e_tag) {
55 value = (char *)value +
56 sizeof(ext3_acl_entry_short);
57 acl->a_entries[n].e_id = ACL_UNDEFINED_ID;
62 value = (char *)value + sizeof(ext3_acl_entry);
63 if ((char *)value > end)
65 acl->a_entries[n].e_id =
66 le32_to_cpu(entry->e_id);
78 posix_acl_release(acl);
79 return ERR_PTR(-EINVAL);
83 * Convert from in-memory to filesystem representation.
86 ext3_acl_to_disk(const struct posix_acl *acl, size_t *size)
88 ext3_acl_header *ext_acl;
92 *size = ext3_acl_size(acl->a_count);
93 ext_acl = kmalloc(sizeof(ext3_acl_header) + acl->a_count *
94 sizeof(ext3_acl_entry), GFP_NOFS);
96 return ERR_PTR(-ENOMEM);
97 ext_acl->a_version = cpu_to_le32(EXT3_ACL_VERSION);
98 e = (char *)ext_acl + sizeof(ext3_acl_header);
99 for (n=0; n < acl->a_count; n++) {
100 ext3_acl_entry *entry = (ext3_acl_entry *)e;
101 entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
102 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
103 switch(acl->a_entries[n].e_tag) {
107 cpu_to_le32(acl->a_entries[n].e_id);
108 e += sizeof(ext3_acl_entry);
115 e += sizeof(ext3_acl_entry_short);
122 return (char *)ext_acl;
126 return ERR_PTR(-EINVAL);
130 * Inode operation get_posix_acl().
132 * inode->i_mutex: don't care
134 static struct posix_acl *
135 ext3_get_acl(struct inode *inode, int type)
139 struct posix_acl *acl;
142 if (!test_opt(inode->i_sb, POSIX_ACL))
145 acl = get_cached_acl(inode, type);
146 if (acl != ACL_NOT_CACHED)
150 case ACL_TYPE_ACCESS:
151 name_index = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS;
153 case ACL_TYPE_DEFAULT:
154 name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
160 retval = ext3_xattr_get(inode, name_index, "", NULL, 0);
162 value = kmalloc(retval, GFP_NOFS);
164 return ERR_PTR(-ENOMEM);
165 retval = ext3_xattr_get(inode, name_index, "", value, retval);
168 acl = ext3_acl_from_disk(value, retval);
169 else if (retval == -ENODATA || retval == -ENOSYS)
172 acl = ERR_PTR(retval);
176 set_cached_acl(inode, type, acl);
182 * Set the access or default ACL of an inode.
184 * inode->i_mutex: down unless called from ext3_new_inode
187 ext3_set_acl(handle_t *handle, struct inode *inode, int type,
188 struct posix_acl *acl)
195 if (S_ISLNK(inode->i_mode))
199 case ACL_TYPE_ACCESS:
200 name_index = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS;
202 mode_t mode = inode->i_mode;
203 error = posix_acl_equiv_mode(acl, &mode);
207 inode->i_mode = mode;
208 inode->i_ctime = CURRENT_TIME_SEC;
209 ext3_mark_inode_dirty(handle, inode);
216 case ACL_TYPE_DEFAULT:
217 name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
218 if (!S_ISDIR(inode->i_mode))
219 return acl ? -EACCES : 0;
226 value = ext3_acl_to_disk(acl, &size);
228 return (int)PTR_ERR(value);
231 error = ext3_xattr_set_handle(handle, inode, name_index, "",
237 set_cached_acl(inode, type, acl);
243 ext3_check_acl(struct inode *inode, int mask, unsigned int flags)
245 struct posix_acl *acl;
247 if (flags & IPERM_FLAG_RCU)
250 acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
254 int error = posix_acl_permission(inode, acl, mask);
255 posix_acl_release(acl);
263 * Initialize the ACLs of a new inode. Called from ext3_new_inode.
266 * inode->i_mutex: up (access to inode is still exclusive)
269 ext3_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
271 struct posix_acl *acl = NULL;
274 if (!S_ISLNK(inode->i_mode)) {
275 if (test_opt(dir->i_sb, POSIX_ACL)) {
276 acl = ext3_get_acl(dir, ACL_TYPE_DEFAULT);
281 inode->i_mode &= ~current_umask();
283 if (test_opt(inode->i_sb, POSIX_ACL) && acl) {
284 struct posix_acl *clone;
287 if (S_ISDIR(inode->i_mode)) {
288 error = ext3_set_acl(handle, inode,
289 ACL_TYPE_DEFAULT, acl);
293 clone = posix_acl_clone(acl, GFP_NOFS);
298 mode = inode->i_mode;
299 error = posix_acl_create_masq(clone, &mode);
301 inode->i_mode = mode;
303 /* This is an extended ACL */
304 error = ext3_set_acl(handle, inode,
305 ACL_TYPE_ACCESS, clone);
308 posix_acl_release(clone);
311 posix_acl_release(acl);
316 * Does chmod for an inode that may have an Access Control List. The
317 * inode->i_mode field must be updated to the desired value by the caller
318 * before calling this function.
319 * Returns 0 on success, or a negative error number.
321 * We change the ACL rather than storing some ACL entries in the file
322 * mode permission bits (which would be more efficient), because that
323 * would break once additional permissions (like ACL_APPEND, ACL_DELETE
324 * for directories) are added. There are no more bits available in the
327 * inode->i_mutex: down
330 ext3_acl_chmod(struct inode *inode)
332 struct posix_acl *acl, *clone;
335 if (S_ISLNK(inode->i_mode))
337 if (!test_opt(inode->i_sb, POSIX_ACL))
339 acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
340 if (IS_ERR(acl) || !acl)
342 clone = posix_acl_clone(acl, GFP_KERNEL);
343 posix_acl_release(acl);
346 error = posix_acl_chmod_masq(clone, inode->i_mode);
352 handle = ext3_journal_start(inode,
353 EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
354 if (IS_ERR(handle)) {
355 error = PTR_ERR(handle);
356 ext3_std_error(inode->i_sb, error);
359 error = ext3_set_acl(handle, inode, ACL_TYPE_ACCESS, clone);
360 ext3_journal_stop(handle);
361 if (error == -ENOSPC &&
362 ext3_should_retry_alloc(inode->i_sb, &retries))
366 posix_acl_release(clone);
371 * Extended attribute handlers
374 ext3_xattr_list_acl_access(struct dentry *dentry, char *list, size_t list_len,
375 const char *name, size_t name_len, int type)
377 const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
379 if (!test_opt(dentry->d_sb, POSIX_ACL))
381 if (list && size <= list_len)
382 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
387 ext3_xattr_list_acl_default(struct dentry *dentry, char *list, size_t list_len,
388 const char *name, size_t name_len, int type)
390 const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
392 if (!test_opt(dentry->d_sb, POSIX_ACL))
394 if (list && size <= list_len)
395 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
400 ext3_xattr_get_acl(struct dentry *dentry, const char *name, void *buffer,
401 size_t size, int type)
403 struct posix_acl *acl;
406 if (strcmp(name, "") != 0)
408 if (!test_opt(dentry->d_sb, POSIX_ACL))
411 acl = ext3_get_acl(dentry->d_inode, type);
416 error = posix_acl_to_xattr(acl, buffer, size);
417 posix_acl_release(acl);
423 ext3_xattr_set_acl(struct dentry *dentry, const char *name, const void *value,
424 size_t size, int flags, int type)
426 struct inode *inode = dentry->d_inode;
428 struct posix_acl *acl;
429 int error, retries = 0;
431 if (strcmp(name, "") != 0)
433 if (!test_opt(inode->i_sb, POSIX_ACL))
435 if (!is_owner_or_cap(inode))
439 acl = posix_acl_from_xattr(value, size);
443 error = posix_acl_valid(acl);
445 goto release_and_out;
451 handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
453 return PTR_ERR(handle);
454 error = ext3_set_acl(handle, inode, type, acl);
455 ext3_journal_stop(handle);
456 if (error == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
460 posix_acl_release(acl);
464 const struct xattr_handler ext3_xattr_acl_access_handler = {
465 .prefix = POSIX_ACL_XATTR_ACCESS,
466 .flags = ACL_TYPE_ACCESS,
467 .list = ext3_xattr_list_acl_access,
468 .get = ext3_xattr_get_acl,
469 .set = ext3_xattr_set_acl,
472 const struct xattr_handler ext3_xattr_acl_default_handler = {
473 .prefix = POSIX_ACL_XATTR_DEFAULT,
474 .flags = ACL_TYPE_DEFAULT,
475 .list = ext3_xattr_list_acl_default,
476 .get = ext3_xattr_get_acl,
477 .set = ext3_xattr_set_acl,