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
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 * Initialize the ACLs of a new inode. Called from ext3_new_inode.
246 * inode->i_mutex: up (access to inode is still exclusive)
249 ext3_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
251 struct posix_acl *acl = NULL;
254 if (!S_ISLNK(inode->i_mode)) {
255 if (test_opt(dir->i_sb, POSIX_ACL)) {
256 acl = ext3_get_acl(dir, ACL_TYPE_DEFAULT);
261 inode->i_mode &= ~current_umask();
263 if (test_opt(inode->i_sb, POSIX_ACL) && acl) {
264 mode_t mode = inode->i_mode;
266 if (S_ISDIR(inode->i_mode)) {
267 error = ext3_set_acl(handle, inode,
268 ACL_TYPE_DEFAULT, acl);
272 error = posix_acl_create(&acl, GFP_NOFS, &mode);
276 inode->i_mode = mode;
278 /* This is an extended ACL */
279 error = ext3_set_acl(handle, inode, ACL_TYPE_ACCESS, acl);
283 posix_acl_release(acl);
288 * Does chmod for an inode that may have an Access Control List. The
289 * inode->i_mode field must be updated to the desired value by the caller
290 * before calling this function.
291 * Returns 0 on success, or a negative error number.
293 * We change the ACL rather than storing some ACL entries in the file
294 * mode permission bits (which would be more efficient), because that
295 * would break once additional permissions (like ACL_APPEND, ACL_DELETE
296 * for directories) are added. There are no more bits available in the
299 * inode->i_mutex: down
302 ext3_acl_chmod(struct inode *inode)
304 struct posix_acl *acl;
309 if (S_ISLNK(inode->i_mode))
311 if (!test_opt(inode->i_sb, POSIX_ACL))
313 acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
314 if (IS_ERR(acl) || !acl)
316 error = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
320 handle = ext3_journal_start(inode,
321 EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
322 if (IS_ERR(handle)) {
323 error = PTR_ERR(handle);
324 ext3_std_error(inode->i_sb, error);
327 error = ext3_set_acl(handle, inode, ACL_TYPE_ACCESS, acl);
328 ext3_journal_stop(handle);
329 if (error == -ENOSPC &&
330 ext3_should_retry_alloc(inode->i_sb, &retries))
333 posix_acl_release(acl);
338 * Extended attribute handlers
341 ext3_xattr_list_acl_access(struct dentry *dentry, char *list, size_t list_len,
342 const char *name, size_t name_len, int type)
344 const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
346 if (!test_opt(dentry->d_sb, POSIX_ACL))
348 if (list && size <= list_len)
349 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
354 ext3_xattr_list_acl_default(struct dentry *dentry, char *list, size_t list_len,
355 const char *name, size_t name_len, int type)
357 const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
359 if (!test_opt(dentry->d_sb, POSIX_ACL))
361 if (list && size <= list_len)
362 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
367 ext3_xattr_get_acl(struct dentry *dentry, const char *name, void *buffer,
368 size_t size, int type)
370 struct posix_acl *acl;
373 if (strcmp(name, "") != 0)
375 if (!test_opt(dentry->d_sb, POSIX_ACL))
378 acl = ext3_get_acl(dentry->d_inode, type);
383 error = posix_acl_to_xattr(acl, buffer, size);
384 posix_acl_release(acl);
390 ext3_xattr_set_acl(struct dentry *dentry, const char *name, const void *value,
391 size_t size, int flags, int type)
393 struct inode *inode = dentry->d_inode;
395 struct posix_acl *acl;
396 int error, retries = 0;
398 if (strcmp(name, "") != 0)
400 if (!test_opt(inode->i_sb, POSIX_ACL))
402 if (!inode_owner_or_capable(inode))
406 acl = posix_acl_from_xattr(value, size);
410 error = posix_acl_valid(acl);
412 goto release_and_out;
418 handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
420 return PTR_ERR(handle);
421 error = ext3_set_acl(handle, inode, type, acl);
422 ext3_journal_stop(handle);
423 if (error == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
427 posix_acl_release(acl);
431 const struct xattr_handler ext3_xattr_acl_access_handler = {
432 .prefix = POSIX_ACL_XATTR_ACCESS,
433 .flags = ACL_TYPE_ACCESS,
434 .list = ext3_xattr_list_acl_access,
435 .get = ext3_xattr_get_acl,
436 .set = ext3_xattr_set_acl,
439 const struct xattr_handler ext3_xattr_acl_default_handler = {
440 .prefix = POSIX_ACL_XATTR_DEFAULT,
441 .flags = ACL_TYPE_DEFAULT,
442 .list = ext3_xattr_list_acl_default,
443 .get = ext3_xattr_get_acl,
444 .set = ext3_xattr_set_acl,