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 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 * Initialize the ACLs of a new inode. Called from ext3_new_inode.
246 * inode->i_mutex: up (access to inode is still exclusive)
249 ext3_init_acl(handle_t
*handle
, struct inode
*inode
, struct inode
*dir
)
251 struct posix_acl
*acl
= NULL
;
254 if (!S_ISLNK(inode
->i_mode
)) {
255 if (test_opt(dir
->i_sb
, POSIX_ACL
)) {
256 acl
= ext3_get_acl(dir
, ACL_TYPE_DEFAULT
);
261 inode
->i_mode
&= ~current_umask();
263 if (test_opt(inode
->i_sb
, POSIX_ACL
) && acl
) {
264 mode_t mode
= inode
->i_mode
;
266 if (S_ISDIR(inode
->i_mode
)) {
267 error
= ext3_set_acl(handle
, inode
,
268 ACL_TYPE_DEFAULT
, acl
);
272 error
= posix_acl_create(&acl
, GFP_NOFS
, &mode
);
276 inode
->i_mode
= mode
;
278 /* This is an extended ACL */
279 error
= ext3_set_acl(handle
, inode
, ACL_TYPE_ACCESS
, acl
);
283 posix_acl_release(acl
);
288 * Does chmod for an inode that may have an Access Control List. The
289 * inode->i_mode field must be updated to the desired value by the caller
290 * before calling this function.
291 * Returns 0 on success, or a negative error number.
293 * We change the ACL rather than storing some ACL entries in the file
294 * mode permission bits (which would be more efficient), because that
295 * would break once additional permissions (like ACL_APPEND, ACL_DELETE
296 * for directories) are added. There are no more bits available in the
299 * inode->i_mutex: down
302 ext3_acl_chmod(struct inode
*inode
)
304 struct posix_acl
*acl
;
309 if (S_ISLNK(inode
->i_mode
))
311 if (!test_opt(inode
->i_sb
, POSIX_ACL
))
313 acl
= ext3_get_acl(inode
, ACL_TYPE_ACCESS
);
314 if (IS_ERR(acl
) || !acl
)
316 error
= posix_acl_chmod(&acl
, GFP_KERNEL
, inode
->i_mode
);
320 handle
= ext3_journal_start(inode
,
321 EXT3_DATA_TRANS_BLOCKS(inode
->i_sb
));
322 if (IS_ERR(handle
)) {
323 error
= PTR_ERR(handle
);
324 ext3_std_error(inode
->i_sb
, error
);
327 error
= ext3_set_acl(handle
, inode
, ACL_TYPE_ACCESS
, acl
);
328 ext3_journal_stop(handle
);
329 if (error
== -ENOSPC
&&
330 ext3_should_retry_alloc(inode
->i_sb
, &retries
))
333 posix_acl_release(acl
);
338 * Extended attribute handlers
341 ext3_xattr_list_acl_access(struct dentry
*dentry
, char *list
, size_t list_len
,
342 const char *name
, size_t name_len
, int type
)
344 const size_t size
= sizeof(POSIX_ACL_XATTR_ACCESS
);
346 if (!test_opt(dentry
->d_sb
, POSIX_ACL
))
348 if (list
&& size
<= list_len
)
349 memcpy(list
, POSIX_ACL_XATTR_ACCESS
, size
);
354 ext3_xattr_list_acl_default(struct dentry
*dentry
, char *list
, size_t list_len
,
355 const char *name
, size_t name_len
, int type
)
357 const size_t size
= sizeof(POSIX_ACL_XATTR_DEFAULT
);
359 if (!test_opt(dentry
->d_sb
, POSIX_ACL
))
361 if (list
&& size
<= list_len
)
362 memcpy(list
, POSIX_ACL_XATTR_DEFAULT
, size
);
367 ext3_xattr_get_acl(struct dentry
*dentry
, const char *name
, void *buffer
,
368 size_t size
, int type
)
370 struct posix_acl
*acl
;
373 if (strcmp(name
, "") != 0)
375 if (!test_opt(dentry
->d_sb
, POSIX_ACL
))
378 acl
= ext3_get_acl(dentry
->d_inode
, type
);
383 error
= posix_acl_to_xattr(acl
, buffer
, size
);
384 posix_acl_release(acl
);
390 ext3_xattr_set_acl(struct dentry
*dentry
, const char *name
, const void *value
,
391 size_t size
, int flags
, int type
)
393 struct inode
*inode
= dentry
->d_inode
;
395 struct posix_acl
*acl
;
396 int error
, retries
= 0;
398 if (strcmp(name
, "") != 0)
400 if (!test_opt(inode
->i_sb
, POSIX_ACL
))
402 if (!inode_owner_or_capable(inode
))
406 acl
= posix_acl_from_xattr(value
, size
);
410 error
= posix_acl_valid(acl
);
412 goto release_and_out
;
418 handle
= ext3_journal_start(inode
, EXT3_DATA_TRANS_BLOCKS(inode
->i_sb
));
420 return PTR_ERR(handle
);
421 error
= ext3_set_acl(handle
, inode
, type
, acl
);
422 ext3_journal_stop(handle
);
423 if (error
== -ENOSPC
&& ext3_should_retry_alloc(inode
->i_sb
, &retries
))
427 posix_acl_release(acl
);
431 const struct xattr_handler ext3_xattr_acl_access_handler
= {
432 .prefix
= POSIX_ACL_XATTR_ACCESS
,
433 .flags
= ACL_TYPE_ACCESS
,
434 .list
= ext3_xattr_list_acl_access
,
435 .get
= ext3_xattr_get_acl
,
436 .set
= ext3_xattr_set_acl
,
439 const struct xattr_handler ext3_xattr_acl_default_handler
= {
440 .prefix
= POSIX_ACL_XATTR_DEFAULT
,
441 .flags
= ACL_TYPE_DEFAULT
,
442 .list
= ext3_xattr_list_acl_default
,
443 .get
= ext3_xattr_get_acl
,
444 .set
= ext3_xattr_set_acl
,