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)
245 struct posix_acl *acl;
247 acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
251 int error = posix_acl_permission(inode, acl, mask);
252 posix_acl_release(acl);
260 * Initialize the ACLs of a new inode. Called from ext3_new_inode.
263 * inode->i_mutex: up (access to inode is still exclusive)
266 ext3_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
268 struct posix_acl *acl = NULL;
271 if (!S_ISLNK(inode->i_mode)) {
272 if (test_opt(dir->i_sb, POSIX_ACL)) {
273 acl = ext3_get_acl(dir, ACL_TYPE_DEFAULT);
278 inode->i_mode &= ~current_umask();
280 if (test_opt(inode->i_sb, POSIX_ACL) && acl) {
281 mode_t mode = inode->i_mode;
283 if (S_ISDIR(inode->i_mode)) {
284 error = ext3_set_acl(handle, inode,
285 ACL_TYPE_DEFAULT, acl);
289 error = posix_acl_create(&acl, GFP_NOFS, &mode);
293 inode->i_mode = mode;
295 /* This is an extended ACL */
296 error = ext3_set_acl(handle, inode, ACL_TYPE_ACCESS, acl);
300 posix_acl_release(acl);
305 * Does chmod for an inode that may have an Access Control List. The
306 * inode->i_mode field must be updated to the desired value by the caller
307 * before calling this function.
308 * Returns 0 on success, or a negative error number.
310 * We change the ACL rather than storing some ACL entries in the file
311 * mode permission bits (which would be more efficient), because that
312 * would break once additional permissions (like ACL_APPEND, ACL_DELETE
313 * for directories) are added. There are no more bits available in the
316 * inode->i_mutex: down
319 ext3_acl_chmod(struct inode *inode)
321 struct posix_acl *acl;
326 if (S_ISLNK(inode->i_mode))
328 if (!test_opt(inode->i_sb, POSIX_ACL))
330 acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
331 if (IS_ERR(acl) || !acl)
333 error = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
337 handle = ext3_journal_start(inode,
338 EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
339 if (IS_ERR(handle)) {
340 error = PTR_ERR(handle);
341 ext3_std_error(inode->i_sb, error);
344 error = ext3_set_acl(handle, inode, ACL_TYPE_ACCESS, acl);
345 ext3_journal_stop(handle);
346 if (error == -ENOSPC &&
347 ext3_should_retry_alloc(inode->i_sb, &retries))
350 posix_acl_release(acl);
355 * Extended attribute handlers
358 ext3_xattr_list_acl_access(struct dentry *dentry, char *list, size_t list_len,
359 const char *name, size_t name_len, int type)
361 const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
363 if (!test_opt(dentry->d_sb, POSIX_ACL))
365 if (list && size <= list_len)
366 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
371 ext3_xattr_list_acl_default(struct dentry *dentry, char *list, size_t list_len,
372 const char *name, size_t name_len, int type)
374 const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
376 if (!test_opt(dentry->d_sb, POSIX_ACL))
378 if (list && size <= list_len)
379 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
384 ext3_xattr_get_acl(struct dentry *dentry, const char *name, void *buffer,
385 size_t size, int type)
387 struct posix_acl *acl;
390 if (strcmp(name, "") != 0)
392 if (!test_opt(dentry->d_sb, POSIX_ACL))
395 acl = ext3_get_acl(dentry->d_inode, type);
400 error = posix_acl_to_xattr(acl, buffer, size);
401 posix_acl_release(acl);
407 ext3_xattr_set_acl(struct dentry *dentry, const char *name, const void *value,
408 size_t size, int flags, int type)
410 struct inode *inode = dentry->d_inode;
412 struct posix_acl *acl;
413 int error, retries = 0;
415 if (strcmp(name, "") != 0)
417 if (!test_opt(inode->i_sb, POSIX_ACL))
419 if (!inode_owner_or_capable(inode))
423 acl = posix_acl_from_xattr(value, size);
427 error = posix_acl_valid(acl);
429 goto release_and_out;
435 handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
437 return PTR_ERR(handle);
438 error = ext3_set_acl(handle, inode, type, acl);
439 ext3_journal_stop(handle);
440 if (error == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
444 posix_acl_release(acl);
448 const struct xattr_handler ext3_xattr_acl_access_handler = {
449 .prefix = POSIX_ACL_XATTR_ACCESS,
450 .flags = ACL_TYPE_ACCESS,
451 .list = ext3_xattr_list_acl_access,
452 .get = ext3_xattr_get_acl,
453 .set = ext3_xattr_set_acl,
456 const struct xattr_handler ext3_xattr_acl_default_handler = {
457 .prefix = POSIX_ACL_XATTR_DEFAULT,
458 .flags = ACL_TYPE_DEFAULT,
459 .list = ext3_xattr_list_acl_default,
460 .get = ext3_xattr_get_acl,
461 .set = ext3_xattr_set_acl,