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>
11 #include <linux/ext3_jbd.h>
12 #include <linux/ext3_fs.h>
17 * Convert from filesystem to in-memory representation.
19 static struct posix_acl *
20 ext3_acl_from_disk(const void *value, size_t size)
22 const char *end = (char *)value + size;
24 struct posix_acl *acl;
28 if (size < sizeof(ext3_acl_header))
29 return ERR_PTR(-EINVAL);
30 if (((ext3_acl_header *)value)->a_version !=
31 cpu_to_le32(EXT3_ACL_VERSION))
32 return ERR_PTR(-EINVAL);
33 value = (char *)value + sizeof(ext3_acl_header);
34 count = ext3_acl_count(size);
36 return ERR_PTR(-EINVAL);
39 acl = posix_acl_alloc(count, GFP_KERNEL);
41 return ERR_PTR(-ENOMEM);
42 for (n=0; n < count; n++) {
43 ext3_acl_entry *entry =
44 (ext3_acl_entry *)value;
45 if ((char *)value + sizeof(ext3_acl_entry_short) > end)
47 acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
48 acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
49 switch(acl->a_entries[n].e_tag) {
54 value = (char *)value +
55 sizeof(ext3_acl_entry_short);
56 acl->a_entries[n].e_id = ACL_UNDEFINED_ID;
61 value = (char *)value + sizeof(ext3_acl_entry);
62 if ((char *)value > end)
64 acl->a_entries[n].e_id =
65 le32_to_cpu(entry->e_id);
77 posix_acl_release(acl);
78 return ERR_PTR(-EINVAL);
82 * Convert from in-memory to filesystem representation.
85 ext3_acl_to_disk(const struct posix_acl *acl, size_t *size)
87 ext3_acl_header *ext_acl;
91 *size = ext3_acl_size(acl->a_count);
92 ext_acl = (ext3_acl_header *)kmalloc(sizeof(ext3_acl_header) +
93 acl->a_count * sizeof(ext3_acl_entry), GFP_KERNEL);
95 return ERR_PTR(-ENOMEM);
96 ext_acl->a_version = cpu_to_le32(EXT3_ACL_VERSION);
97 e = (char *)ext_acl + sizeof(ext3_acl_header);
98 for (n=0; n < acl->a_count; n++) {
99 ext3_acl_entry *entry = (ext3_acl_entry *)e;
100 entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
101 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
102 switch(acl->a_entries[n].e_tag) {
106 cpu_to_le32(acl->a_entries[n].e_id);
107 e += sizeof(ext3_acl_entry);
114 e += sizeof(ext3_acl_entry_short);
121 return (char *)ext_acl;
125 return ERR_PTR(-EINVAL);
128 static inline struct posix_acl *
129 ext3_iget_acl(struct inode *inode, struct posix_acl **i_acl)
131 struct posix_acl *acl = EXT3_ACL_NOT_CACHED;
133 spin_lock(&inode->i_lock);
134 if (*i_acl != EXT3_ACL_NOT_CACHED)
135 acl = posix_acl_dup(*i_acl);
136 spin_unlock(&inode->i_lock);
142 ext3_iset_acl(struct inode *inode, struct posix_acl **i_acl,
143 struct posix_acl *acl)
145 spin_lock(&inode->i_lock);
146 if (*i_acl != EXT3_ACL_NOT_CACHED)
147 posix_acl_release(*i_acl);
148 *i_acl = posix_acl_dup(acl);
149 spin_unlock(&inode->i_lock);
153 * Inode operation get_posix_acl().
155 * inode->i_sem: don't care
157 static struct posix_acl *
158 ext3_get_acl(struct inode *inode, int type)
160 struct ext3_inode_info *ei = EXT3_I(inode);
163 struct posix_acl *acl;
166 if (!test_opt(inode->i_sb, POSIX_ACL))
170 case ACL_TYPE_ACCESS:
171 acl = ext3_iget_acl(inode, &ei->i_acl);
172 if (acl != EXT3_ACL_NOT_CACHED)
174 name_index = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS;
177 case ACL_TYPE_DEFAULT:
178 acl = ext3_iget_acl(inode, &ei->i_default_acl);
179 if (acl != EXT3_ACL_NOT_CACHED)
181 name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
185 return ERR_PTR(-EINVAL);
187 retval = ext3_xattr_get(inode, name_index, "", NULL, 0);
189 value = kmalloc(retval, GFP_KERNEL);
191 return ERR_PTR(-ENOMEM);
192 retval = ext3_xattr_get(inode, name_index, "", value, retval);
195 acl = ext3_acl_from_disk(value, retval);
196 else if (retval == -ENODATA || retval == -ENOSYS)
199 acl = ERR_PTR(retval);
204 case ACL_TYPE_ACCESS:
205 ext3_iset_acl(inode, &ei->i_acl, acl);
208 case ACL_TYPE_DEFAULT:
209 ext3_iset_acl(inode, &ei->i_default_acl, acl);
217 * Set the access or default ACL of an inode.
219 * inode->i_sem: down unless called from ext3_new_inode
222 ext3_set_acl(handle_t *handle, struct inode *inode, int type,
223 struct posix_acl *acl)
225 struct ext3_inode_info *ei = EXT3_I(inode);
231 if (S_ISLNK(inode->i_mode))
235 case ACL_TYPE_ACCESS:
236 name_index = EXT3_XATTR_INDEX_POSIX_ACL_ACCESS;
238 mode_t mode = inode->i_mode;
239 error = posix_acl_equiv_mode(acl, &mode);
243 inode->i_mode = mode;
244 ext3_mark_inode_dirty(handle, inode);
251 case ACL_TYPE_DEFAULT:
252 name_index = EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT;
253 if (!S_ISDIR(inode->i_mode))
254 return acl ? -EACCES : 0;
261 value = ext3_acl_to_disk(acl, &size);
263 return (int)PTR_ERR(value);
266 error = ext3_xattr_set_handle(handle, inode, name_index, "",
272 case ACL_TYPE_ACCESS:
273 ext3_iset_acl(inode, &ei->i_acl, acl);
276 case ACL_TYPE_DEFAULT:
277 ext3_iset_acl(inode, &ei->i_default_acl, acl);
285 ext3_check_acl(struct inode *inode, int mask)
287 struct posix_acl *acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
290 int error = posix_acl_permission(inode, acl, mask);
291 posix_acl_release(acl);
299 ext3_permission(struct inode *inode, int mask, struct nameidata *nd)
301 return generic_permission(inode, mask, ext3_check_acl);
305 * Initialize the ACLs of a new inode. Called from ext3_new_inode.
308 * inode->i_sem: up (access to inode is still exclusive)
311 ext3_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
313 struct posix_acl *acl = NULL;
316 if (!S_ISLNK(inode->i_mode)) {
317 if (test_opt(dir->i_sb, POSIX_ACL)) {
318 acl = ext3_get_acl(dir, ACL_TYPE_DEFAULT);
323 inode->i_mode &= ~current->fs->umask;
325 if (test_opt(inode->i_sb, POSIX_ACL) && acl) {
326 struct posix_acl *clone;
329 if (S_ISDIR(inode->i_mode)) {
330 error = ext3_set_acl(handle, inode,
331 ACL_TYPE_DEFAULT, acl);
335 clone = posix_acl_clone(acl, GFP_KERNEL);
340 mode = inode->i_mode;
341 error = posix_acl_create_masq(clone, &mode);
343 inode->i_mode = mode;
345 /* This is an extended ACL */
346 error = ext3_set_acl(handle, inode,
347 ACL_TYPE_ACCESS, clone);
350 posix_acl_release(clone);
353 posix_acl_release(acl);
358 * Does chmod for an inode that may have an Access Control List. The
359 * inode->i_mode field must be updated to the desired value by the caller
360 * before calling this function.
361 * Returns 0 on success, or a negative error number.
363 * We change the ACL rather than storing some ACL entries in the file
364 * mode permission bits (which would be more efficient), because that
365 * would break once additional permissions (like ACL_APPEND, ACL_DELETE
366 * for directories) are added. There are no more bits available in the
372 ext3_acl_chmod(struct inode *inode)
374 struct posix_acl *acl, *clone;
377 if (S_ISLNK(inode->i_mode))
379 if (!test_opt(inode->i_sb, POSIX_ACL))
381 acl = ext3_get_acl(inode, ACL_TYPE_ACCESS);
382 if (IS_ERR(acl) || !acl)
384 clone = posix_acl_clone(acl, GFP_KERNEL);
385 posix_acl_release(acl);
388 error = posix_acl_chmod_masq(clone, inode->i_mode);
394 handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS);
395 if (IS_ERR(handle)) {
396 error = PTR_ERR(handle);
397 ext3_std_error(inode->i_sb, error);
400 error = ext3_set_acl(handle, inode, ACL_TYPE_ACCESS, clone);
401 ext3_journal_stop(handle);
402 if (error == -ENOSPC &&
403 ext3_should_retry_alloc(inode->i_sb, &retries))
407 posix_acl_release(clone);
412 * Extended attribute handlers
415 ext3_xattr_list_acl_access(struct inode *inode, char *list, size_t list_len,
416 const char *name, size_t name_len)
418 const size_t size = sizeof(XATTR_NAME_ACL_ACCESS);
420 if (!test_opt(inode->i_sb, POSIX_ACL))
422 if (list && size <= list_len)
423 memcpy(list, XATTR_NAME_ACL_ACCESS, size);
428 ext3_xattr_list_acl_default(struct inode *inode, char *list, size_t list_len,
429 const char *name, size_t name_len)
431 const size_t size = sizeof(XATTR_NAME_ACL_DEFAULT);
433 if (!test_opt(inode->i_sb, POSIX_ACL))
435 if (list && size <= list_len)
436 memcpy(list, XATTR_NAME_ACL_DEFAULT, size);
441 ext3_xattr_get_acl(struct inode *inode, int type, void *buffer, size_t size)
443 struct posix_acl *acl;
446 if (!test_opt(inode->i_sb, POSIX_ACL))
449 acl = ext3_get_acl(inode, type);
454 error = posix_acl_to_xattr(acl, buffer, size);
455 posix_acl_release(acl);
461 ext3_xattr_get_acl_access(struct inode *inode, const char *name,
462 void *buffer, size_t size)
464 if (strcmp(name, "") != 0)
466 return ext3_xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size);
470 ext3_xattr_get_acl_default(struct inode *inode, const char *name,
471 void *buffer, size_t size)
473 if (strcmp(name, "") != 0)
475 return ext3_xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size);
479 ext3_xattr_set_acl(struct inode *inode, int type, const void *value,
483 struct posix_acl *acl;
484 int error, retries = 0;
486 if (!test_opt(inode->i_sb, POSIX_ACL))
488 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
492 acl = posix_acl_from_xattr(value, size);
496 error = posix_acl_valid(acl);
498 goto release_and_out;
504 handle = ext3_journal_start(inode, EXT3_DATA_TRANS_BLOCKS);
506 return PTR_ERR(handle);
507 error = ext3_set_acl(handle, inode, type, acl);
508 ext3_journal_stop(handle);
509 if (error == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
513 posix_acl_release(acl);
518 ext3_xattr_set_acl_access(struct inode *inode, const char *name,
519 const void *value, size_t size, int flags)
521 if (strcmp(name, "") != 0)
523 return ext3_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
527 ext3_xattr_set_acl_default(struct inode *inode, const char *name,
528 const void *value, size_t size, int flags)
530 if (strcmp(name, "") != 0)
532 return ext3_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
535 struct xattr_handler ext3_xattr_acl_access_handler = {
536 .prefix = XATTR_NAME_ACL_ACCESS,
537 .list = ext3_xattr_list_acl_access,
538 .get = ext3_xattr_get_acl_access,
539 .set = ext3_xattr_set_acl_access,
542 struct xattr_handler ext3_xattr_acl_default_handler = {
543 .prefix = XATTR_NAME_ACL_DEFAULT,
544 .list = ext3_xattr_list_acl_default,
545 .get = ext3_xattr_get_acl_default,
546 .set = ext3_xattr_set_acl_default,