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 error = posix_acl_update_mode(inode, &inode->i_mode, &acl);
205 inode->i_ctime = CURRENT_TIME_SEC;
206 ext3_mark_inode_dirty(handle, inode);
210 case ACL_TYPE_DEFAULT:
211 name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
212 if (!S_ISDIR(inode->i_mode))
213 return acl ? -EACCES : 0;
220 value = ext3_acl_to_disk(acl, &size);
222 return (int)PTR_ERR(value);
225 error = ext3_xattr_set_handle(handle, inode, name_index, "",
231 set_cached_acl(inode, type, acl);
237 * Initialize the ACLs of a new inode. Called from ext3_new_inode.
240 * inode->i_mutex: up (access to inode is still exclusive)
243 ext3_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
245 struct posix_acl *acl = NULL;
248 if (!S_ISLNK(inode->i_mode)) {
249 if (test_opt(dir->i_sb, POSIX_ACL)) {
250 acl = ext3_get_acl(dir, ACL_TYPE_DEFAULT);
255 inode->i_mode &= ~current_umask();
257 if (test_opt(inode->i_sb, POSIX_ACL) && acl) {
258 if (S_ISDIR(inode->i_mode)) {
259 error = ext3_set_acl(handle, inode,
260 ACL_TYPE_DEFAULT, acl);
264 error = posix_acl_create(&acl, GFP_NOFS, &inode->i_mode);
269 /* This is an extended ACL */
270 error = ext3_set_acl(handle, inode, ACL_TYPE_ACCESS, acl);
274 posix_acl_release(acl);
279 * Does chmod for an inode that may have an Access Control List. The
280 * inode->i_mode field must be updated to the desired value by the caller
281 * before calling this function.
282 * Returns 0 on success, or a negative error number.
284 * We change the ACL rather than storing some ACL entries in the file
285 * mode permission bits (which would be more efficient), because that
286 * would break once additional permissions (like ACL_APPEND, ACL_DELETE
287 * for directories) are added. There are no more bits available in the
290 * inode->i_mutex: down
293 ext3_acl_chmod(struct inode *inode)
295 struct posix_acl *acl;
300 if (S_ISLNK(inode->i_mode))
302 if (!test_opt(inode->i_sb, POSIX_ACL))
304 acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
305 if (IS_ERR(acl) || !acl)
307 error = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
311 handle = ext3_journal_start(inode,
312 EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
313 if (IS_ERR(handle)) {
314 error = PTR_ERR(handle);
315 ext3_std_error(inode->i_sb, error);
318 error = ext3_set_acl(handle, inode, ACL_TYPE_ACCESS, acl);
319 ext3_journal_stop(handle);
320 if (error == -ENOSPC &&
321 ext3_should_retry_alloc(inode->i_sb, &retries))
324 posix_acl_release(acl);
329 * Extended attribute handlers
332 ext3_xattr_list_acl_access(struct dentry *dentry, char *list, size_t list_len,
333 const char *name, size_t name_len, int type)
335 const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
337 if (!test_opt(dentry->d_sb, POSIX_ACL))
339 if (list && size <= list_len)
340 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
345 ext3_xattr_list_acl_default(struct dentry *dentry, char *list, size_t list_len,
346 const char *name, size_t name_len, int type)
348 const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
350 if (!test_opt(dentry->d_sb, POSIX_ACL))
352 if (list && size <= list_len)
353 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
358 ext3_xattr_get_acl(struct dentry *dentry, const char *name, void *buffer,
359 size_t size, int type)
361 struct posix_acl *acl;
364 if (strcmp(name, "") != 0)
366 if (!test_opt(dentry->d_sb, POSIX_ACL))
369 acl = ext3_get_acl(dentry->d_inode, type);
374 error = posix_acl_to_xattr(acl, buffer, size);
375 posix_acl_release(acl);
381 ext3_xattr_set_acl(struct dentry *dentry, const char *name, const void *value,
382 size_t size, int flags, int type)
384 struct inode *inode = dentry->d_inode;
386 struct posix_acl *acl;
387 int error, retries = 0;
389 if (strcmp(name, "") != 0)
391 if (!test_opt(inode->i_sb, POSIX_ACL))
393 if (!inode_owner_or_capable(inode))
397 acl = posix_acl_from_xattr(value, size);
401 error = posix_acl_valid(acl);
403 goto release_and_out;
409 handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS(inode->i_sb));
411 return PTR_ERR(handle);
412 error = ext3_set_acl(handle, inode, type, acl);
413 ext3_journal_stop(handle);
414 if (error == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
418 posix_acl_release(acl);
422 const struct xattr_handler ext3_xattr_acl_access_handler = {
423 .prefix = POSIX_ACL_XATTR_ACCESS,
424 .flags = ACL_TYPE_ACCESS,
425 .list = ext3_xattr_list_acl_access,
426 .get = ext3_xattr_get_acl,
427 .set = ext3_xattr_set_acl,
430 const struct xattr_handler ext3_xattr_acl_default_handler = {
431 .prefix = POSIX_ACL_XATTR_DEFAULT,
432 .flags = ACL_TYPE_DEFAULT,
433 .list = ext3_xattr_list_acl_default,
434 .get = ext3_xattr_get_acl,
435 .set = ext3_xattr_set_acl,