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 "ext4_jbd2.h"
18 * Convert from filesystem to in-memory representation.
20 static struct posix_acl *
21 ext4_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(ext4_acl_header))
30 return ERR_PTR(-EINVAL);
31 if (((ext4_acl_header *)value)->a_version !=
32 cpu_to_le32(EXT4_ACL_VERSION))
33 return ERR_PTR(-EINVAL);
34 value = (char *)value + sizeof(ext4_acl_header);
35 count = ext4_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 ext4_acl_entry *entry =
45 (ext4_acl_entry *)value;
46 if ((char *)value + sizeof(ext4_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);
51 switch (acl->a_entries[n].e_tag) {
56 value = (char *)value +
57 sizeof(ext4_acl_entry_short);
58 acl->a_entries[n].e_id = ACL_UNDEFINED_ID;
63 value = (char *)value + sizeof(ext4_acl_entry);
64 if ((char *)value > end)
66 acl->a_entries[n].e_id =
67 le32_to_cpu(entry->e_id);
79 posix_acl_release(acl);
80 return ERR_PTR(-EINVAL);
84 * Convert from in-memory to filesystem representation.
87 ext4_acl_to_disk(const struct posix_acl *acl, size_t *size)
89 ext4_acl_header *ext_acl;
93 *size = ext4_acl_size(acl->a_count);
94 ext_acl = kmalloc(sizeof(ext4_acl_header) + acl->a_count *
95 sizeof(ext4_acl_entry), GFP_NOFS);
97 return ERR_PTR(-ENOMEM);
98 ext_acl->a_version = cpu_to_le32(EXT4_ACL_VERSION);
99 e = (char *)ext_acl + sizeof(ext4_acl_header);
100 for (n = 0; n < acl->a_count; n++) {
101 ext4_acl_entry *entry = (ext4_acl_entry *)e;
102 entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
103 entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
104 switch (acl->a_entries[n].e_tag) {
107 entry->e_id = cpu_to_le32(acl->a_entries[n].e_id);
108 e += sizeof(ext4_acl_entry);
115 e += sizeof(ext4_acl_entry_short);
122 return (char *)ext_acl;
126 return ERR_PTR(-EINVAL);
129 static inline struct posix_acl *
130 ext4_iget_acl(struct inode *inode, struct posix_acl **i_acl)
132 struct posix_acl *acl = ACCESS_ONCE(*i_acl);
135 spin_lock(&inode->i_lock);
137 if (acl != ACL_NOT_CACHED)
138 acl = posix_acl_dup(acl);
139 spin_unlock(&inode->i_lock);
146 ext4_iset_acl(struct inode *inode, struct posix_acl **i_acl,
147 struct posix_acl *acl)
149 spin_lock(&inode->i_lock);
150 if (*i_acl != ACL_NOT_CACHED)
151 posix_acl_release(*i_acl);
152 *i_acl = posix_acl_dup(acl);
153 spin_unlock(&inode->i_lock);
157 * Inode operation get_posix_acl().
159 * inode->i_mutex: don't care
161 static struct posix_acl *
162 ext4_get_acl(struct inode *inode, int type)
166 struct posix_acl *acl;
169 if (!test_opt(inode->i_sb, POSIX_ACL))
173 case ACL_TYPE_ACCESS:
174 acl = ext4_iget_acl(inode, &inode->i_acl);
175 if (acl != ACL_NOT_CACHED)
177 name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
180 case ACL_TYPE_DEFAULT:
181 acl = ext4_iget_acl(inode, &inode->i_default_acl);
182 if (acl != ACL_NOT_CACHED)
184 name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
188 return ERR_PTR(-EINVAL);
190 retval = ext4_xattr_get(inode, name_index, "", NULL, 0);
192 value = kmalloc(retval, GFP_NOFS);
194 return ERR_PTR(-ENOMEM);
195 retval = ext4_xattr_get(inode, name_index, "", value, retval);
198 acl = ext4_acl_from_disk(value, retval);
199 else if (retval == -ENODATA || retval == -ENOSYS)
202 acl = ERR_PTR(retval);
207 case ACL_TYPE_ACCESS:
208 ext4_iset_acl(inode, &inode->i_acl, acl);
211 case ACL_TYPE_DEFAULT:
212 ext4_iset_acl(inode, &inode->i_default_acl, acl);
220 * Set the access or default ACL of an inode.
222 * inode->i_mutex: down unless called from ext4_new_inode
225 ext4_set_acl(handle_t *handle, struct inode *inode, int type,
226 struct posix_acl *acl)
233 if (S_ISLNK(inode->i_mode))
237 case ACL_TYPE_ACCESS:
238 name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS;
240 mode_t mode = inode->i_mode;
241 error = posix_acl_equiv_mode(acl, &mode);
245 inode->i_mode = mode;
246 ext4_mark_inode_dirty(handle, inode);
253 case ACL_TYPE_DEFAULT:
254 name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT;
255 if (!S_ISDIR(inode->i_mode))
256 return acl ? -EACCES : 0;
263 value = ext4_acl_to_disk(acl, &size);
265 return (int)PTR_ERR(value);
268 error = ext4_xattr_set_handle(handle, inode, name_index, "",
274 case ACL_TYPE_ACCESS:
275 ext4_iset_acl(inode, &inode->i_acl, acl);
278 case ACL_TYPE_DEFAULT:
279 ext4_iset_acl(inode, &inode->i_default_acl, acl);
287 ext4_check_acl(struct inode *inode, int mask)
289 struct posix_acl *acl = ext4_get_acl(inode, ACL_TYPE_ACCESS);
294 int error = posix_acl_permission(inode, acl, mask);
295 posix_acl_release(acl);
303 ext4_permission(struct inode *inode, int mask)
305 return generic_permission(inode, mask, ext4_check_acl);
309 * Initialize the ACLs of a new inode. Called from ext4_new_inode.
312 * inode->i_mutex: up (access to inode is still exclusive)
315 ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
317 struct posix_acl *acl = NULL;
320 if (!S_ISLNK(inode->i_mode)) {
321 if (test_opt(dir->i_sb, POSIX_ACL)) {
322 acl = ext4_get_acl(dir, ACL_TYPE_DEFAULT);
327 inode->i_mode &= ~current_umask();
329 if (test_opt(inode->i_sb, POSIX_ACL) && acl) {
330 struct posix_acl *clone;
333 if (S_ISDIR(inode->i_mode)) {
334 error = ext4_set_acl(handle, inode,
335 ACL_TYPE_DEFAULT, acl);
339 clone = posix_acl_clone(acl, GFP_NOFS);
344 mode = inode->i_mode;
345 error = posix_acl_create_masq(clone, &mode);
347 inode->i_mode = mode;
349 /* This is an extended ACL */
350 error = ext4_set_acl(handle, inode,
351 ACL_TYPE_ACCESS, clone);
354 posix_acl_release(clone);
357 posix_acl_release(acl);
362 * Does chmod for an inode that may have an Access Control List. The
363 * inode->i_mode field must be updated to the desired value by the caller
364 * before calling this function.
365 * Returns 0 on success, or a negative error number.
367 * We change the ACL rather than storing some ACL entries in the file
368 * mode permission bits (which would be more efficient), because that
369 * would break once additional permissions (like ACL_APPEND, ACL_DELETE
370 * for directories) are added. There are no more bits available in the
373 * inode->i_mutex: down
376 ext4_acl_chmod(struct inode *inode)
378 struct posix_acl *acl, *clone;
381 if (S_ISLNK(inode->i_mode))
383 if (!test_opt(inode->i_sb, POSIX_ACL))
385 acl = ext4_get_acl(inode, ACL_TYPE_ACCESS);
386 if (IS_ERR(acl) || !acl)
388 clone = posix_acl_clone(acl, GFP_KERNEL);
389 posix_acl_release(acl);
392 error = posix_acl_chmod_masq(clone, inode->i_mode);
398 handle = ext4_journal_start(inode,
399 EXT4_DATA_TRANS_BLOCKS(inode->i_sb));
400 if (IS_ERR(handle)) {
401 error = PTR_ERR(handle);
402 ext4_std_error(inode->i_sb, error);
405 error = ext4_set_acl(handle, inode, ACL_TYPE_ACCESS, clone);
406 ext4_journal_stop(handle);
407 if (error == -ENOSPC &&
408 ext4_should_retry_alloc(inode->i_sb, &retries))
412 posix_acl_release(clone);
417 * Extended attribute handlers
420 ext4_xattr_list_acl_access(struct inode *inode, char *list, size_t list_len,
421 const char *name, size_t name_len)
423 const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS);
425 if (!test_opt(inode->i_sb, POSIX_ACL))
427 if (list && size <= list_len)
428 memcpy(list, POSIX_ACL_XATTR_ACCESS, size);
433 ext4_xattr_list_acl_default(struct inode *inode, char *list, size_t list_len,
434 const char *name, size_t name_len)
436 const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT);
438 if (!test_opt(inode->i_sb, POSIX_ACL))
440 if (list && size <= list_len)
441 memcpy(list, POSIX_ACL_XATTR_DEFAULT, size);
446 ext4_xattr_get_acl(struct inode *inode, int type, void *buffer, size_t size)
448 struct posix_acl *acl;
451 if (!test_opt(inode->i_sb, POSIX_ACL))
454 acl = ext4_get_acl(inode, type);
459 error = posix_acl_to_xattr(acl, buffer, size);
460 posix_acl_release(acl);
466 ext4_xattr_get_acl_access(struct inode *inode, const char *name,
467 void *buffer, size_t size)
469 if (strcmp(name, "") != 0)
471 return ext4_xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size);
475 ext4_xattr_get_acl_default(struct inode *inode, const char *name,
476 void *buffer, size_t size)
478 if (strcmp(name, "") != 0)
480 return ext4_xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size);
484 ext4_xattr_set_acl(struct inode *inode, int type, const void *value,
488 struct posix_acl *acl;
489 int error, retries = 0;
491 if (!test_opt(inode->i_sb, POSIX_ACL))
493 if (!is_owner_or_cap(inode))
497 acl = posix_acl_from_xattr(value, size);
501 error = posix_acl_valid(acl);
503 goto release_and_out;
509 handle = ext4_journal_start(inode, EXT4_DATA_TRANS_BLOCKS(inode->i_sb));
511 return PTR_ERR(handle);
512 error = ext4_set_acl(handle, inode, type, acl);
513 ext4_journal_stop(handle);
514 if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
518 posix_acl_release(acl);
523 ext4_xattr_set_acl_access(struct inode *inode, const char *name,
524 const void *value, size_t size, int flags)
526 if (strcmp(name, "") != 0)
528 return ext4_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size);
532 ext4_xattr_set_acl_default(struct inode *inode, const char *name,
533 const void *value, size_t size, int flags)
535 if (strcmp(name, "") != 0)
537 return ext4_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size);
540 struct xattr_handler ext4_xattr_acl_access_handler = {
541 .prefix = POSIX_ACL_XATTR_ACCESS,
542 .list = ext4_xattr_list_acl_access,
543 .get = ext4_xattr_get_acl_access,
544 .set = ext4_xattr_set_acl_access,
547 struct xattr_handler ext4_xattr_acl_default_handler = {
548 .prefix = POSIX_ACL_XATTR_DEFAULT,
549 .list = ext4_xattr_list_acl_default,
550 .get = ext4_xattr_get_acl_default,
551 .set = ext4_xattr_set_acl_default,