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 struct posix_acl
*clone
;
284 if (S_ISDIR(inode
->i_mode
)) {
285 error
= ext3_set_acl(handle
, inode
,
286 ACL_TYPE_DEFAULT
, acl
);
290 clone
= posix_acl_clone(acl
, GFP_NOFS
);
295 mode
= inode
->i_mode
;
296 error
= posix_acl_create_masq(clone
, &mode
);
298 inode
->i_mode
= mode
;
300 /* This is an extended ACL */
301 error
= ext3_set_acl(handle
, inode
,
302 ACL_TYPE_ACCESS
, clone
);
305 posix_acl_release(clone
);
308 posix_acl_release(acl
);
313 * Does chmod for an inode that may have an Access Control List. The
314 * inode->i_mode field must be updated to the desired value by the caller
315 * before calling this function.
316 * Returns 0 on success, or a negative error number.
318 * We change the ACL rather than storing some ACL entries in the file
319 * mode permission bits (which would be more efficient), because that
320 * would break once additional permissions (like ACL_APPEND, ACL_DELETE
321 * for directories) are added. There are no more bits available in the
324 * inode->i_mutex: down
327 ext3_acl_chmod(struct inode
*inode
)
329 struct posix_acl
*acl
;
334 if (S_ISLNK(inode
->i_mode
))
336 if (!test_opt(inode
->i_sb
, POSIX_ACL
))
338 acl
= ext3_get_acl(inode
, ACL_TYPE_ACCESS
);
339 if (IS_ERR(acl
) || !acl
)
341 error
= posix_acl_chmod(&acl
, GFP_KERNEL
, inode
->i_mode
);
345 handle
= ext3_journal_start(inode
,
346 EXT3_DATA_TRANS_BLOCKS(inode
->i_sb
));
347 if (IS_ERR(handle
)) {
348 error
= PTR_ERR(handle
);
349 ext3_std_error(inode
->i_sb
, error
);
352 error
= ext3_set_acl(handle
, inode
, ACL_TYPE_ACCESS
, acl
);
353 ext3_journal_stop(handle
);
354 if (error
== -ENOSPC
&&
355 ext3_should_retry_alloc(inode
->i_sb
, &retries
))
358 posix_acl_release(acl
);
363 * Extended attribute handlers
366 ext3_xattr_list_acl_access(struct dentry
*dentry
, char *list
, size_t list_len
,
367 const char *name
, size_t name_len
, int type
)
369 const size_t size
= sizeof(POSIX_ACL_XATTR_ACCESS
);
371 if (!test_opt(dentry
->d_sb
, POSIX_ACL
))
373 if (list
&& size
<= list_len
)
374 memcpy(list
, POSIX_ACL_XATTR_ACCESS
, size
);
379 ext3_xattr_list_acl_default(struct dentry
*dentry
, char *list
, size_t list_len
,
380 const char *name
, size_t name_len
, int type
)
382 const size_t size
= sizeof(POSIX_ACL_XATTR_DEFAULT
);
384 if (!test_opt(dentry
->d_sb
, POSIX_ACL
))
386 if (list
&& size
<= list_len
)
387 memcpy(list
, POSIX_ACL_XATTR_DEFAULT
, size
);
392 ext3_xattr_get_acl(struct dentry
*dentry
, const char *name
, void *buffer
,
393 size_t size
, int type
)
395 struct posix_acl
*acl
;
398 if (strcmp(name
, "") != 0)
400 if (!test_opt(dentry
->d_sb
, POSIX_ACL
))
403 acl
= ext3_get_acl(dentry
->d_inode
, type
);
408 error
= posix_acl_to_xattr(acl
, buffer
, size
);
409 posix_acl_release(acl
);
415 ext3_xattr_set_acl(struct dentry
*dentry
, const char *name
, const void *value
,
416 size_t size
, int flags
, int type
)
418 struct inode
*inode
= dentry
->d_inode
;
420 struct posix_acl
*acl
;
421 int error
, retries
= 0;
423 if (strcmp(name
, "") != 0)
425 if (!test_opt(inode
->i_sb
, POSIX_ACL
))
427 if (!inode_owner_or_capable(inode
))
431 acl
= posix_acl_from_xattr(value
, size
);
435 error
= posix_acl_valid(acl
);
437 goto release_and_out
;
443 handle
= ext3_journal_start(inode
, EXT3_DATA_TRANS_BLOCKS(inode
->i_sb
));
445 return PTR_ERR(handle
);
446 error
= ext3_set_acl(handle
, inode
, type
, acl
);
447 ext3_journal_stop(handle
);
448 if (error
== -ENOSPC
&& ext3_should_retry_alloc(inode
->i_sb
, &retries
))
452 posix_acl_release(acl
);
456 const struct xattr_handler ext3_xattr_acl_access_handler
= {
457 .prefix
= POSIX_ACL_XATTR_ACCESS
,
458 .flags
= ACL_TYPE_ACCESS
,
459 .list
= ext3_xattr_list_acl_access
,
460 .get
= ext3_xattr_get_acl
,
461 .set
= ext3_xattr_set_acl
,
464 const struct xattr_handler ext3_xattr_acl_default_handler
= {
465 .prefix
= POSIX_ACL_XATTR_DEFAULT
,
466 .flags
= ACL_TYPE_DEFAULT
,
467 .list
= ext3_xattr_list_acl_default
,
468 .get
= ext3_xattr_get_acl
,
469 .set
= ext3_xattr_set_acl
,