2 * linux/fs/ext3/xattr.c
4 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
6 * Fix by Harrison Xing <harrison@mountainviewdata.com>.
7 * Ext3 code with a lot of help from Eric Jarman <ejarman@acm.org>.
8 * Extended attributes for symlinks and special files added per
9 * suggestion of Luka Renko <luka.renko@hermes.si>.
10 * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>,
12 * ea-in-inode support by Alex Tomas <alex@clusterfs.com> aka bzzz
13 * and Andreas Gruenbacher <agruen@suse.de>.
17 * Extended attributes are stored directly in inodes (on file systems with
18 * inodes bigger than 128 bytes) and on additional disk blocks. The i_file_acl
19 * field contains the block number if an inode uses an additional block. All
20 * attributes must fit in the inode and one additional block. Blocks that
21 * contain the identical set of attributes may be shared among several inodes.
22 * Identical blocks are detected by keeping a cache of blocks that have
23 * recently been accessed.
25 * The attributes in inodes and on blocks have a different header; the entries
26 * are stored in the same format:
28 * +------------------+
31 * | entry 2 | | growing downwards
36 * | value 3 | | growing upwards
38 * +------------------+
40 * The header is followed by multiple entry descriptors. In disk blocks, the
41 * entry descriptors are kept sorted. In inodes, they are unsorted. The
42 * attribute values are aligned to the end of the block in no specific order.
46 * EXT3_I(inode)->i_file_acl is protected by EXT3_I(inode)->xattr_sem.
47 * EA blocks are only changed if they are exclusive to an inode, so
48 * holding xattr_sem also means that nothing but the EA block's reference
49 * count can change. Multiple writers to the same block are synchronized
54 #include <linux/mbcache.h>
55 #include <linux/quotaops.h>
59 #define BHDR(bh) ((struct ext3_xattr_header *)((bh)->b_data))
60 #define ENTRY(ptr) ((struct ext3_xattr_entry *)(ptr))
61 #define BFIRST(bh) ENTRY(BHDR(bh)+1)
62 #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
64 #define IHDR(inode, raw_inode) \
65 ((struct ext3_xattr_ibody_header *) \
66 ((void *)raw_inode + \
67 EXT3_GOOD_OLD_INODE_SIZE + \
68 EXT3_I(inode)->i_extra_isize))
69 #define IFIRST(hdr) ((struct ext3_xattr_entry *)((hdr)+1))
71 #ifdef EXT3_XATTR_DEBUG
72 # define ea_idebug(inode, f...) do { \
73 printk(KERN_DEBUG "inode %s:%lu: ", \
74 inode->i_sb->s_id, inode->i_ino); \
78 # define ea_bdebug(bh, f...) do { \
79 char b[BDEVNAME_SIZE]; \
80 printk(KERN_DEBUG "block %s:%lu: ", \
81 bdevname(bh->b_bdev, b), \
82 (unsigned long) bh->b_blocknr); \
87 # define ea_idebug(f...)
88 # define ea_bdebug(f...)
91 static void ext3_xattr_cache_insert(struct buffer_head
*);
92 static struct buffer_head
*ext3_xattr_cache_find(struct inode
*,
93 struct ext3_xattr_header
*,
94 struct mb_cache_entry
**);
95 static void ext3_xattr_rehash(struct ext3_xattr_header
*,
96 struct ext3_xattr_entry
*);
97 static int ext3_xattr_list(struct dentry
*dentry
, char *buffer
,
100 static struct mb_cache
*ext3_xattr_cache
;
102 static const struct xattr_handler
*ext3_xattr_handler_map
[] = {
103 [EXT3_XATTR_INDEX_USER
] = &ext3_xattr_user_handler
,
104 #ifdef CONFIG_EXT3_FS_POSIX_ACL
105 [EXT3_XATTR_INDEX_POSIX_ACL_ACCESS
] = &posix_acl_access_xattr_handler
,
106 [EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT
] = &posix_acl_default_xattr_handler
,
108 [EXT3_XATTR_INDEX_TRUSTED
] = &ext3_xattr_trusted_handler
,
109 #ifdef CONFIG_EXT3_FS_SECURITY
110 [EXT3_XATTR_INDEX_SECURITY
] = &ext3_xattr_security_handler
,
114 const struct xattr_handler
*ext3_xattr_handlers
[] = {
115 &ext3_xattr_user_handler
,
116 &ext3_xattr_trusted_handler
,
117 #ifdef CONFIG_EXT3_FS_POSIX_ACL
118 &posix_acl_access_xattr_handler
,
119 &posix_acl_default_xattr_handler
,
121 #ifdef CONFIG_EXT3_FS_SECURITY
122 &ext3_xattr_security_handler
,
127 static inline const struct xattr_handler
*
128 ext3_xattr_handler(int name_index
)
130 const struct xattr_handler
*handler
= NULL
;
132 if (name_index
> 0 && name_index
< ARRAY_SIZE(ext3_xattr_handler_map
))
133 handler
= ext3_xattr_handler_map
[name_index
];
138 * Inode operation listxattr()
140 * d_inode(dentry)->i_mutex: don't care
143 ext3_listxattr(struct dentry
*dentry
, char *buffer
, size_t size
)
145 return ext3_xattr_list(dentry
, buffer
, size
);
149 ext3_xattr_check_names(struct ext3_xattr_entry
*entry
, void *end
)
151 while (!IS_LAST_ENTRY(entry
)) {
152 struct ext3_xattr_entry
*next
= EXT3_XATTR_NEXT(entry
);
153 if ((void *)next
>= end
)
161 ext3_xattr_check_block(struct buffer_head
*bh
)
165 if (BHDR(bh
)->h_magic
!= cpu_to_le32(EXT3_XATTR_MAGIC
) ||
166 BHDR(bh
)->h_blocks
!= cpu_to_le32(1))
168 error
= ext3_xattr_check_names(BFIRST(bh
), bh
->b_data
+ bh
->b_size
);
173 ext3_xattr_check_entry(struct ext3_xattr_entry
*entry
, size_t size
)
175 size_t value_size
= le32_to_cpu(entry
->e_value_size
);
177 if (entry
->e_value_block
!= 0 || value_size
> size
||
178 le16_to_cpu(entry
->e_value_offs
) + value_size
> size
)
184 ext3_xattr_find_entry(struct ext3_xattr_entry
**pentry
, int name_index
,
185 const char *name
, size_t size
, int sorted
)
187 struct ext3_xattr_entry
*entry
;
193 name_len
= strlen(name
);
195 for (; !IS_LAST_ENTRY(entry
); entry
= EXT3_XATTR_NEXT(entry
)) {
196 cmp
= name_index
- entry
->e_name_index
;
198 cmp
= name_len
- entry
->e_name_len
;
200 cmp
= memcmp(name
, entry
->e_name
, name_len
);
201 if (cmp
<= 0 && (sorted
|| cmp
== 0))
205 if (!cmp
&& ext3_xattr_check_entry(entry
, size
))
207 return cmp
? -ENODATA
: 0;
211 ext3_xattr_block_get(struct inode
*inode
, int name_index
, const char *name
,
212 void *buffer
, size_t buffer_size
)
214 struct buffer_head
*bh
= NULL
;
215 struct ext3_xattr_entry
*entry
;
219 ea_idebug(inode
, "name=%d.%s, buffer=%p, buffer_size=%ld",
220 name_index
, name
, buffer
, (long)buffer_size
);
223 if (!EXT3_I(inode
)->i_file_acl
)
225 ea_idebug(inode
, "reading block %u", EXT3_I(inode
)->i_file_acl
);
226 bh
= sb_bread(inode
->i_sb
, EXT3_I(inode
)->i_file_acl
);
229 ea_bdebug(bh
, "b_count=%d, refcount=%d",
230 atomic_read(&(bh
->b_count
)), le32_to_cpu(BHDR(bh
)->h_refcount
));
231 if (ext3_xattr_check_block(bh
)) {
232 bad_block
: ext3_error(inode
->i_sb
, __func__
,
233 "inode %lu: bad block "E3FSBLK
, inode
->i_ino
,
234 EXT3_I(inode
)->i_file_acl
);
238 ext3_xattr_cache_insert(bh
);
240 error
= ext3_xattr_find_entry(&entry
, name_index
, name
, bh
->b_size
, 1);
245 size
= le32_to_cpu(entry
->e_value_size
);
248 if (size
> buffer_size
)
250 memcpy(buffer
, bh
->b_data
+ le16_to_cpu(entry
->e_value_offs
),
261 ext3_xattr_ibody_get(struct inode
*inode
, int name_index
, const char *name
,
262 void *buffer
, size_t buffer_size
)
264 struct ext3_xattr_ibody_header
*header
;
265 struct ext3_xattr_entry
*entry
;
266 struct ext3_inode
*raw_inode
;
267 struct ext3_iloc iloc
;
272 if (!ext3_test_inode_state(inode
, EXT3_STATE_XATTR
))
274 error
= ext3_get_inode_loc(inode
, &iloc
);
277 raw_inode
= ext3_raw_inode(&iloc
);
278 header
= IHDR(inode
, raw_inode
);
279 entry
= IFIRST(header
);
280 end
= (void *)raw_inode
+ EXT3_SB(inode
->i_sb
)->s_inode_size
;
281 error
= ext3_xattr_check_names(entry
, end
);
284 error
= ext3_xattr_find_entry(&entry
, name_index
, name
,
285 end
- (void *)entry
, 0);
288 size
= le32_to_cpu(entry
->e_value_size
);
291 if (size
> buffer_size
)
293 memcpy(buffer
, (void *)IFIRST(header
) +
294 le16_to_cpu(entry
->e_value_offs
), size
);
306 * Copy an extended attribute into the buffer
307 * provided, or compute the buffer size required.
308 * Buffer is NULL to compute the size of the buffer required.
310 * Returns a negative error number on failure, or the number of bytes
311 * used / required on success.
314 ext3_xattr_get(struct inode
*inode
, int name_index
, const char *name
,
315 void *buffer
, size_t buffer_size
)
319 down_read(&EXT3_I(inode
)->xattr_sem
);
320 error
= ext3_xattr_ibody_get(inode
, name_index
, name
, buffer
,
322 if (error
== -ENODATA
)
323 error
= ext3_xattr_block_get(inode
, name_index
, name
, buffer
,
325 up_read(&EXT3_I(inode
)->xattr_sem
);
330 ext3_xattr_list_entries(struct dentry
*dentry
, struct ext3_xattr_entry
*entry
,
331 char *buffer
, size_t buffer_size
)
333 size_t rest
= buffer_size
;
335 for (; !IS_LAST_ENTRY(entry
); entry
= EXT3_XATTR_NEXT(entry
)) {
336 const struct xattr_handler
*handler
=
337 ext3_xattr_handler(entry
->e_name_index
);
340 size_t size
= handler
->list(dentry
, buffer
, rest
,
352 return buffer_size
- rest
;
356 ext3_xattr_block_list(struct dentry
*dentry
, char *buffer
, size_t buffer_size
)
358 struct inode
*inode
= d_inode(dentry
);
359 struct buffer_head
*bh
= NULL
;
362 ea_idebug(inode
, "buffer=%p, buffer_size=%ld",
363 buffer
, (long)buffer_size
);
366 if (!EXT3_I(inode
)->i_file_acl
)
368 ea_idebug(inode
, "reading block %u", EXT3_I(inode
)->i_file_acl
);
369 bh
= sb_bread(inode
->i_sb
, EXT3_I(inode
)->i_file_acl
);
373 ea_bdebug(bh
, "b_count=%d, refcount=%d",
374 atomic_read(&(bh
->b_count
)), le32_to_cpu(BHDR(bh
)->h_refcount
));
375 if (ext3_xattr_check_block(bh
)) {
376 ext3_error(inode
->i_sb
, __func__
,
377 "inode %lu: bad block "E3FSBLK
, inode
->i_ino
,
378 EXT3_I(inode
)->i_file_acl
);
382 ext3_xattr_cache_insert(bh
);
383 error
= ext3_xattr_list_entries(dentry
, BFIRST(bh
), buffer
, buffer_size
);
392 ext3_xattr_ibody_list(struct dentry
*dentry
, char *buffer
, size_t buffer_size
)
394 struct inode
*inode
= d_inode(dentry
);
395 struct ext3_xattr_ibody_header
*header
;
396 struct ext3_inode
*raw_inode
;
397 struct ext3_iloc iloc
;
401 if (!ext3_test_inode_state(inode
, EXT3_STATE_XATTR
))
403 error
= ext3_get_inode_loc(inode
, &iloc
);
406 raw_inode
= ext3_raw_inode(&iloc
);
407 header
= IHDR(inode
, raw_inode
);
408 end
= (void *)raw_inode
+ EXT3_SB(inode
->i_sb
)->s_inode_size
;
409 error
= ext3_xattr_check_names(IFIRST(header
), end
);
412 error
= ext3_xattr_list_entries(dentry
, IFIRST(header
),
413 buffer
, buffer_size
);
423 * Copy a list of attribute names into the buffer
424 * provided, or compute the buffer size required.
425 * Buffer is NULL to compute the size of the buffer required.
427 * Returns a negative error number on failure, or the number of bytes
428 * used / required on success.
431 ext3_xattr_list(struct dentry
*dentry
, char *buffer
, size_t buffer_size
)
433 int i_error
, b_error
;
435 down_read(&EXT3_I(d_inode(dentry
))->xattr_sem
);
436 i_error
= ext3_xattr_ibody_list(dentry
, buffer
, buffer_size
);
442 buffer_size
-= i_error
;
444 b_error
= ext3_xattr_block_list(dentry
, buffer
, buffer_size
);
448 up_read(&EXT3_I(d_inode(dentry
))->xattr_sem
);
449 return i_error
+ b_error
;
453 * If the EXT3_FEATURE_COMPAT_EXT_ATTR feature of this file system is
456 static void ext3_xattr_update_super_block(handle_t
*handle
,
457 struct super_block
*sb
)
459 if (EXT3_HAS_COMPAT_FEATURE(sb
, EXT3_FEATURE_COMPAT_EXT_ATTR
))
462 if (ext3_journal_get_write_access(handle
, EXT3_SB(sb
)->s_sbh
) == 0) {
463 EXT3_SET_COMPAT_FEATURE(sb
, EXT3_FEATURE_COMPAT_EXT_ATTR
);
464 ext3_journal_dirty_metadata(handle
, EXT3_SB(sb
)->s_sbh
);
469 * Release the xattr block BH: If the reference count is > 1, decrement
470 * it; otherwise free the block.
473 ext3_xattr_release_block(handle_t
*handle
, struct inode
*inode
,
474 struct buffer_head
*bh
)
476 struct mb_cache_entry
*ce
= NULL
;
479 ce
= mb_cache_entry_get(ext3_xattr_cache
, bh
->b_bdev
, bh
->b_blocknr
);
480 error
= ext3_journal_get_write_access(handle
, bh
);
486 if (BHDR(bh
)->h_refcount
== cpu_to_le32(1)) {
487 ea_bdebug(bh
, "refcount now=0; freeing");
489 mb_cache_entry_free(ce
);
490 ext3_free_blocks(handle
, inode
, bh
->b_blocknr
, 1);
492 ext3_forget(handle
, 1, inode
, bh
, bh
->b_blocknr
);
494 le32_add_cpu(&BHDR(bh
)->h_refcount
, -1);
495 error
= ext3_journal_dirty_metadata(handle
, bh
);
498 dquot_free_block(inode
, 1);
499 ea_bdebug(bh
, "refcount now=%d; releasing",
500 le32_to_cpu(BHDR(bh
)->h_refcount
));
502 mb_cache_entry_release(ce
);
506 ext3_std_error(inode
->i_sb
, error
);
510 struct ext3_xattr_info
{
517 struct ext3_xattr_search
{
518 struct ext3_xattr_entry
*first
;
521 struct ext3_xattr_entry
*here
;
526 ext3_xattr_set_entry(struct ext3_xattr_info
*i
, struct ext3_xattr_search
*s
)
528 struct ext3_xattr_entry
*last
;
529 size_t free
, min_offs
= s
->end
- s
->base
, name_len
= strlen(i
->name
);
531 /* Compute min_offs and last. */
533 for (; !IS_LAST_ENTRY(last
); last
= EXT3_XATTR_NEXT(last
)) {
534 if (!last
->e_value_block
&& last
->e_value_size
) {
535 size_t offs
= le16_to_cpu(last
->e_value_offs
);
540 free
= min_offs
- ((void *)last
- s
->base
) - sizeof(__u32
);
542 if (!s
->here
->e_value_block
&& s
->here
->e_value_size
) {
543 size_t size
= le32_to_cpu(s
->here
->e_value_size
);
544 free
+= EXT3_XATTR_SIZE(size
);
546 free
+= EXT3_XATTR_LEN(name_len
);
549 if (free
< EXT3_XATTR_LEN(name_len
) +
550 EXT3_XATTR_SIZE(i
->value_len
))
554 if (i
->value
&& s
->not_found
) {
555 /* Insert the new name. */
556 size_t size
= EXT3_XATTR_LEN(name_len
);
557 size_t rest
= (void *)last
- (void *)s
->here
+ sizeof(__u32
);
558 memmove((void *)s
->here
+ size
, s
->here
, rest
);
559 memset(s
->here
, 0, size
);
560 s
->here
->e_name_index
= i
->name_index
;
561 s
->here
->e_name_len
= name_len
;
562 memcpy(s
->here
->e_name
, i
->name
, name_len
);
564 if (!s
->here
->e_value_block
&& s
->here
->e_value_size
) {
565 void *first_val
= s
->base
+ min_offs
;
566 size_t offs
= le16_to_cpu(s
->here
->e_value_offs
);
567 void *val
= s
->base
+ offs
;
568 size_t size
= EXT3_XATTR_SIZE(
569 le32_to_cpu(s
->here
->e_value_size
));
571 if (i
->value
&& size
== EXT3_XATTR_SIZE(i
->value_len
)) {
572 /* The old and the new value have the same
573 size. Just replace. */
574 s
->here
->e_value_size
=
575 cpu_to_le32(i
->value_len
);
576 memset(val
+ size
- EXT3_XATTR_PAD
, 0,
577 EXT3_XATTR_PAD
); /* Clear pad bytes. */
578 memcpy(val
, i
->value
, i
->value_len
);
582 /* Remove the old value. */
583 memmove(first_val
+ size
, first_val
, val
- first_val
);
584 memset(first_val
, 0, size
);
585 s
->here
->e_value_size
= 0;
586 s
->here
->e_value_offs
= 0;
589 /* Adjust all value offsets. */
591 while (!IS_LAST_ENTRY(last
)) {
592 size_t o
= le16_to_cpu(last
->e_value_offs
);
593 if (!last
->e_value_block
&&
594 last
->e_value_size
&& o
< offs
)
596 cpu_to_le16(o
+ size
);
597 last
= EXT3_XATTR_NEXT(last
);
601 /* Remove the old name. */
602 size_t size
= EXT3_XATTR_LEN(name_len
);
603 last
= ENTRY((void *)last
- size
);
604 memmove(s
->here
, (void *)s
->here
+ size
,
605 (void *)last
- (void *)s
->here
+ sizeof(__u32
));
606 memset(last
, 0, size
);
611 /* Insert the new value. */
612 s
->here
->e_value_size
= cpu_to_le32(i
->value_len
);
614 size_t size
= EXT3_XATTR_SIZE(i
->value_len
);
615 void *val
= s
->base
+ min_offs
- size
;
616 s
->here
->e_value_offs
= cpu_to_le16(min_offs
- size
);
617 memset(val
+ size
- EXT3_XATTR_PAD
, 0,
618 EXT3_XATTR_PAD
); /* Clear the pad bytes. */
619 memcpy(val
, i
->value
, i
->value_len
);
625 struct ext3_xattr_block_find
{
626 struct ext3_xattr_search s
;
627 struct buffer_head
*bh
;
631 ext3_xattr_block_find(struct inode
*inode
, struct ext3_xattr_info
*i
,
632 struct ext3_xattr_block_find
*bs
)
634 struct super_block
*sb
= inode
->i_sb
;
637 ea_idebug(inode
, "name=%d.%s, value=%p, value_len=%ld",
638 i
->name_index
, i
->name
, i
->value
, (long)i
->value_len
);
640 if (EXT3_I(inode
)->i_file_acl
) {
641 /* The inode already has an extended attribute block. */
642 bs
->bh
= sb_bread(sb
, EXT3_I(inode
)->i_file_acl
);
646 ea_bdebug(bs
->bh
, "b_count=%d, refcount=%d",
647 atomic_read(&(bs
->bh
->b_count
)),
648 le32_to_cpu(BHDR(bs
->bh
)->h_refcount
));
649 if (ext3_xattr_check_block(bs
->bh
)) {
650 ext3_error(sb
, __func__
,
651 "inode %lu: bad block "E3FSBLK
, inode
->i_ino
,
652 EXT3_I(inode
)->i_file_acl
);
656 /* Find the named attribute. */
657 bs
->s
.base
= BHDR(bs
->bh
);
658 bs
->s
.first
= BFIRST(bs
->bh
);
659 bs
->s
.end
= bs
->bh
->b_data
+ bs
->bh
->b_size
;
660 bs
->s
.here
= bs
->s
.first
;
661 error
= ext3_xattr_find_entry(&bs
->s
.here
, i
->name_index
,
662 i
->name
, bs
->bh
->b_size
, 1);
663 if (error
&& error
!= -ENODATA
)
665 bs
->s
.not_found
= error
;
674 ext3_xattr_block_set(handle_t
*handle
, struct inode
*inode
,
675 struct ext3_xattr_info
*i
,
676 struct ext3_xattr_block_find
*bs
)
678 struct super_block
*sb
= inode
->i_sb
;
679 struct buffer_head
*new_bh
= NULL
;
680 struct ext3_xattr_search
*s
= &bs
->s
;
681 struct mb_cache_entry
*ce
= NULL
;
684 #define header(x) ((struct ext3_xattr_header *)(x))
686 if (i
->value
&& i
->value_len
> sb
->s_blocksize
)
689 ce
= mb_cache_entry_get(ext3_xattr_cache
, bs
->bh
->b_bdev
,
691 error
= ext3_journal_get_write_access(handle
, bs
->bh
);
696 if (header(s
->base
)->h_refcount
== cpu_to_le32(1)) {
698 mb_cache_entry_free(ce
);
701 ea_bdebug(bs
->bh
, "modifying in-place");
702 error
= ext3_xattr_set_entry(i
, s
);
704 if (!IS_LAST_ENTRY(s
->first
))
705 ext3_xattr_rehash(header(s
->base
),
707 ext3_xattr_cache_insert(bs
->bh
);
709 unlock_buffer(bs
->bh
);
713 error
= ext3_journal_dirty_metadata(handle
,
719 int offset
= (char *)s
->here
- bs
->bh
->b_data
;
721 unlock_buffer(bs
->bh
);
722 journal_release_buffer(handle
, bs
->bh
);
725 mb_cache_entry_release(ce
);
728 ea_bdebug(bs
->bh
, "cloning");
729 s
->base
= kmalloc(bs
->bh
->b_size
, GFP_NOFS
);
733 memcpy(s
->base
, BHDR(bs
->bh
), bs
->bh
->b_size
);
734 s
->first
= ENTRY(header(s
->base
)+1);
735 header(s
->base
)->h_refcount
= cpu_to_le32(1);
736 s
->here
= ENTRY(s
->base
+ offset
);
737 s
->end
= s
->base
+ bs
->bh
->b_size
;
740 /* Allocate a buffer where we construct the new block. */
741 s
->base
= kzalloc(sb
->s_blocksize
, GFP_NOFS
);
742 /* assert(header == s->base) */
746 header(s
->base
)->h_magic
= cpu_to_le32(EXT3_XATTR_MAGIC
);
747 header(s
->base
)->h_blocks
= cpu_to_le32(1);
748 header(s
->base
)->h_refcount
= cpu_to_le32(1);
749 s
->first
= ENTRY(header(s
->base
)+1);
750 s
->here
= ENTRY(header(s
->base
)+1);
751 s
->end
= s
->base
+ sb
->s_blocksize
;
754 error
= ext3_xattr_set_entry(i
, s
);
759 if (!IS_LAST_ENTRY(s
->first
))
760 ext3_xattr_rehash(header(s
->base
), s
->here
);
763 if (!IS_LAST_ENTRY(s
->first
)) {
764 new_bh
= ext3_xattr_cache_find(inode
, header(s
->base
), &ce
);
766 /* We found an identical block in the cache. */
767 if (new_bh
== bs
->bh
)
768 ea_bdebug(new_bh
, "keeping");
770 /* The old block is released after updating
772 error
= dquot_alloc_block(inode
, 1);
775 error
= ext3_journal_get_write_access(handle
,
780 le32_add_cpu(&BHDR(new_bh
)->h_refcount
, 1);
781 ea_bdebug(new_bh
, "reusing; refcount now=%d",
782 le32_to_cpu(BHDR(new_bh
)->h_refcount
));
783 unlock_buffer(new_bh
);
784 error
= ext3_journal_dirty_metadata(handle
,
789 mb_cache_entry_release(ce
);
791 } else if (bs
->bh
&& s
->base
== bs
->bh
->b_data
) {
792 /* We were modifying this block in-place. */
793 ea_bdebug(bs
->bh
, "keeping this block");
797 /* We need to allocate a new block */
798 ext3_fsblk_t goal
= ext3_group_first_block_no(sb
,
799 EXT3_I(inode
)->i_block_group
);
803 * Protect us agaist concurrent allocations to the
804 * same inode from ext3_..._writepage(). Reservation
805 * code does not expect racing allocations.
807 mutex_lock(&EXT3_I(inode
)->truncate_mutex
);
808 block
= ext3_new_block(handle
, inode
, goal
, &error
);
809 mutex_unlock(&EXT3_I(inode
)->truncate_mutex
);
812 ea_idebug(inode
, "creating block %d", block
);
814 new_bh
= sb_getblk(sb
, block
);
815 if (unlikely(!new_bh
)) {
817 ext3_free_blocks(handle
, inode
, block
, 1);
822 error
= ext3_journal_get_create_access(handle
, new_bh
);
824 unlock_buffer(new_bh
);
827 memcpy(new_bh
->b_data
, s
->base
, new_bh
->b_size
);
828 set_buffer_uptodate(new_bh
);
829 unlock_buffer(new_bh
);
830 ext3_xattr_cache_insert(new_bh
);
831 error
= ext3_journal_dirty_metadata(handle
, new_bh
);
837 /* Update the inode. */
838 EXT3_I(inode
)->i_file_acl
= new_bh
? new_bh
->b_blocknr
: 0;
840 /* Drop the previous xattr block. */
841 if (bs
->bh
&& bs
->bh
!= new_bh
)
842 ext3_xattr_release_block(handle
, inode
, bs
->bh
);
847 mb_cache_entry_release(ce
);
849 if (!(bs
->bh
&& s
->base
== bs
->bh
->b_data
))
855 dquot_free_block(inode
, 1);
859 ext3_error(inode
->i_sb
, __func__
,
860 "inode %lu: bad block "E3FSBLK
, inode
->i_ino
,
861 EXT3_I(inode
)->i_file_acl
);
867 struct ext3_xattr_ibody_find
{
868 struct ext3_xattr_search s
;
869 struct ext3_iloc iloc
;
873 ext3_xattr_ibody_find(struct inode
*inode
, struct ext3_xattr_info
*i
,
874 struct ext3_xattr_ibody_find
*is
)
876 struct ext3_xattr_ibody_header
*header
;
877 struct ext3_inode
*raw_inode
;
880 if (EXT3_I(inode
)->i_extra_isize
== 0)
882 raw_inode
= ext3_raw_inode(&is
->iloc
);
883 header
= IHDR(inode
, raw_inode
);
884 is
->s
.base
= is
->s
.first
= IFIRST(header
);
885 is
->s
.here
= is
->s
.first
;
886 is
->s
.end
= (void *)raw_inode
+ EXT3_SB(inode
->i_sb
)->s_inode_size
;
887 if (ext3_test_inode_state(inode
, EXT3_STATE_XATTR
)) {
888 error
= ext3_xattr_check_names(IFIRST(header
), is
->s
.end
);
891 /* Find the named attribute. */
892 error
= ext3_xattr_find_entry(&is
->s
.here
, i
->name_index
,
894 (void *)is
->s
.base
, 0);
895 if (error
&& error
!= -ENODATA
)
897 is
->s
.not_found
= error
;
903 ext3_xattr_ibody_set(handle_t
*handle
, struct inode
*inode
,
904 struct ext3_xattr_info
*i
,
905 struct ext3_xattr_ibody_find
*is
)
907 struct ext3_xattr_ibody_header
*header
;
908 struct ext3_xattr_search
*s
= &is
->s
;
911 if (EXT3_I(inode
)->i_extra_isize
== 0)
913 error
= ext3_xattr_set_entry(i
, s
);
916 header
= IHDR(inode
, ext3_raw_inode(&is
->iloc
));
917 if (!IS_LAST_ENTRY(s
->first
)) {
918 header
->h_magic
= cpu_to_le32(EXT3_XATTR_MAGIC
);
919 ext3_set_inode_state(inode
, EXT3_STATE_XATTR
);
921 header
->h_magic
= cpu_to_le32(0);
922 ext3_clear_inode_state(inode
, EXT3_STATE_XATTR
);
928 * ext3_xattr_set_handle()
930 * Create, replace or remove an extended attribute for this inode. Value
931 * is NULL to remove an existing extended attribute, and non-NULL to
932 * either replace an existing extended attribute, or create a new extended
933 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
934 * specify that an extended attribute must exist and must not exist
935 * previous to the call, respectively.
937 * Returns 0, or a negative error number on failure.
940 ext3_xattr_set_handle(handle_t
*handle
, struct inode
*inode
, int name_index
,
941 const char *name
, const void *value
, size_t value_len
,
944 struct ext3_xattr_info i
= {
945 .name_index
= name_index
,
948 .value_len
= value_len
,
951 struct ext3_xattr_ibody_find is
= {
952 .s
= { .not_found
= -ENODATA
, },
954 struct ext3_xattr_block_find bs
= {
955 .s
= { .not_found
= -ENODATA
, },
961 if (strlen(name
) > 255)
963 down_write(&EXT3_I(inode
)->xattr_sem
);
964 error
= ext3_get_inode_loc(inode
, &is
.iloc
);
968 error
= ext3_journal_get_write_access(handle
, is
.iloc
.bh
);
972 if (ext3_test_inode_state(inode
, EXT3_STATE_NEW
)) {
973 struct ext3_inode
*raw_inode
= ext3_raw_inode(&is
.iloc
);
974 memset(raw_inode
, 0, EXT3_SB(inode
->i_sb
)->s_inode_size
);
975 ext3_clear_inode_state(inode
, EXT3_STATE_NEW
);
978 error
= ext3_xattr_ibody_find(inode
, &i
, &is
);
982 error
= ext3_xattr_block_find(inode
, &i
, &bs
);
985 if (is
.s
.not_found
&& bs
.s
.not_found
) {
987 if (flags
& XATTR_REPLACE
)
994 if (flags
& XATTR_CREATE
)
999 error
= ext3_xattr_ibody_set(handle
, inode
, &i
, &is
);
1000 else if (!bs
.s
.not_found
)
1001 error
= ext3_xattr_block_set(handle
, inode
, &i
, &bs
);
1003 error
= ext3_xattr_ibody_set(handle
, inode
, &i
, &is
);
1004 if (!error
&& !bs
.s
.not_found
) {
1006 error
= ext3_xattr_block_set(handle
, inode
, &i
, &bs
);
1007 } else if (error
== -ENOSPC
) {
1008 if (EXT3_I(inode
)->i_file_acl
&& !bs
.s
.base
) {
1009 error
= ext3_xattr_block_find(inode
, &i
, &bs
);
1013 error
= ext3_xattr_block_set(handle
, inode
, &i
, &bs
);
1016 if (!is
.s
.not_found
) {
1018 error
= ext3_xattr_ibody_set(handle
, inode
, &i
,
1024 ext3_xattr_update_super_block(handle
, inode
->i_sb
);
1025 inode
->i_ctime
= CURRENT_TIME_SEC
;
1026 error
= ext3_mark_iloc_dirty(handle
, inode
, &is
.iloc
);
1028 * The bh is consumed by ext3_mark_iloc_dirty, even with
1039 up_write(&EXT3_I(inode
)->xattr_sem
);
1046 * Like ext3_xattr_set_handle, but start from an inode. This extended
1047 * attribute modification is a filesystem transaction by itself.
1049 * Returns 0, or a negative error number on failure.
1052 ext3_xattr_set(struct inode
*inode
, int name_index
, const char *name
,
1053 const void *value
, size_t value_len
, int flags
)
1056 int error
, retries
= 0;
1059 handle
= ext3_journal_start(inode
, EXT3_DATA_TRANS_BLOCKS(inode
->i_sb
));
1060 if (IS_ERR(handle
)) {
1061 error
= PTR_ERR(handle
);
1065 error
= ext3_xattr_set_handle(handle
, inode
, name_index
, name
,
1066 value
, value_len
, flags
);
1067 error2
= ext3_journal_stop(handle
);
1068 if (error
== -ENOSPC
&&
1069 ext3_should_retry_alloc(inode
->i_sb
, &retries
))
1079 * ext3_xattr_delete_inode()
1081 * Free extended attribute resources associated with this inode. This
1082 * is called immediately before an inode is freed. We have exclusive
1083 * access to the inode.
1086 ext3_xattr_delete_inode(handle_t
*handle
, struct inode
*inode
)
1088 struct buffer_head
*bh
= NULL
;
1090 if (!EXT3_I(inode
)->i_file_acl
)
1092 bh
= sb_bread(inode
->i_sb
, EXT3_I(inode
)->i_file_acl
);
1094 ext3_error(inode
->i_sb
, __func__
,
1095 "inode %lu: block "E3FSBLK
" read error", inode
->i_ino
,
1096 EXT3_I(inode
)->i_file_acl
);
1099 if (BHDR(bh
)->h_magic
!= cpu_to_le32(EXT3_XATTR_MAGIC
) ||
1100 BHDR(bh
)->h_blocks
!= cpu_to_le32(1)) {
1101 ext3_error(inode
->i_sb
, __func__
,
1102 "inode %lu: bad block "E3FSBLK
, inode
->i_ino
,
1103 EXT3_I(inode
)->i_file_acl
);
1106 ext3_xattr_release_block(handle
, inode
, bh
);
1107 EXT3_I(inode
)->i_file_acl
= 0;
1114 * ext3_xattr_put_super()
1116 * This is called when a file system is unmounted.
1119 ext3_xattr_put_super(struct super_block
*sb
)
1121 mb_cache_shrink(sb
->s_bdev
);
1125 * ext3_xattr_cache_insert()
1127 * Create a new entry in the extended attribute cache, and insert
1128 * it unless such an entry is already in the cache.
1130 * Returns 0, or a negative error number on failure.
1133 ext3_xattr_cache_insert(struct buffer_head
*bh
)
1135 __u32 hash
= le32_to_cpu(BHDR(bh
)->h_hash
);
1136 struct mb_cache_entry
*ce
;
1139 ce
= mb_cache_entry_alloc(ext3_xattr_cache
, GFP_NOFS
);
1141 ea_bdebug(bh
, "out of memory");
1144 error
= mb_cache_entry_insert(ce
, bh
->b_bdev
, bh
->b_blocknr
, hash
);
1146 mb_cache_entry_free(ce
);
1147 if (error
== -EBUSY
) {
1148 ea_bdebug(bh
, "already in cache");
1152 ea_bdebug(bh
, "inserting [%x]", (int)hash
);
1153 mb_cache_entry_release(ce
);
1160 * Compare two extended attribute blocks for equality.
1162 * Returns 0 if the blocks are equal, 1 if they differ, and
1163 * a negative error number on errors.
1166 ext3_xattr_cmp(struct ext3_xattr_header
*header1
,
1167 struct ext3_xattr_header
*header2
)
1169 struct ext3_xattr_entry
*entry1
, *entry2
;
1171 entry1
= ENTRY(header1
+1);
1172 entry2
= ENTRY(header2
+1);
1173 while (!IS_LAST_ENTRY(entry1
)) {
1174 if (IS_LAST_ENTRY(entry2
))
1176 if (entry1
->e_hash
!= entry2
->e_hash
||
1177 entry1
->e_name_index
!= entry2
->e_name_index
||
1178 entry1
->e_name_len
!= entry2
->e_name_len
||
1179 entry1
->e_value_size
!= entry2
->e_value_size
||
1180 memcmp(entry1
->e_name
, entry2
->e_name
, entry1
->e_name_len
))
1182 if (entry1
->e_value_block
!= 0 || entry2
->e_value_block
!= 0)
1184 if (memcmp((char *)header1
+ le16_to_cpu(entry1
->e_value_offs
),
1185 (char *)header2
+ le16_to_cpu(entry2
->e_value_offs
),
1186 le32_to_cpu(entry1
->e_value_size
)))
1189 entry1
= EXT3_XATTR_NEXT(entry1
);
1190 entry2
= EXT3_XATTR_NEXT(entry2
);
1192 if (!IS_LAST_ENTRY(entry2
))
1198 * ext3_xattr_cache_find()
1200 * Find an identical extended attribute block.
1202 * Returns a pointer to the block found, or NULL if such a block was
1203 * not found or an error occurred.
1205 static struct buffer_head
*
1206 ext3_xattr_cache_find(struct inode
*inode
, struct ext3_xattr_header
*header
,
1207 struct mb_cache_entry
**pce
)
1209 __u32 hash
= le32_to_cpu(header
->h_hash
);
1210 struct mb_cache_entry
*ce
;
1212 if (!header
->h_hash
)
1213 return NULL
; /* never share */
1214 ea_idebug(inode
, "looking for cached blocks [%x]", (int)hash
);
1216 ce
= mb_cache_entry_find_first(ext3_xattr_cache
, inode
->i_sb
->s_bdev
,
1219 struct buffer_head
*bh
;
1222 if (PTR_ERR(ce
) == -EAGAIN
)
1226 bh
= sb_bread(inode
->i_sb
, ce
->e_block
);
1228 ext3_error(inode
->i_sb
, __func__
,
1229 "inode %lu: block %lu read error",
1230 inode
->i_ino
, (unsigned long) ce
->e_block
);
1231 } else if (le32_to_cpu(BHDR(bh
)->h_refcount
) >=
1232 EXT3_XATTR_REFCOUNT_MAX
) {
1233 ea_idebug(inode
, "block %lu refcount %d>=%d",
1234 (unsigned long) ce
->e_block
,
1235 le32_to_cpu(BHDR(bh
)->h_refcount
),
1236 EXT3_XATTR_REFCOUNT_MAX
);
1237 } else if (ext3_xattr_cmp(header
, BHDR(bh
)) == 0) {
1242 ce
= mb_cache_entry_find_next(ce
, inode
->i_sb
->s_bdev
, hash
);
1247 #define NAME_HASH_SHIFT 5
1248 #define VALUE_HASH_SHIFT 16
1251 * ext3_xattr_hash_entry()
1253 * Compute the hash of an extended attribute.
1255 static inline void ext3_xattr_hash_entry(struct ext3_xattr_header
*header
,
1256 struct ext3_xattr_entry
*entry
)
1259 char *name
= entry
->e_name
;
1262 for (n
=0; n
< entry
->e_name_len
; n
++) {
1263 hash
= (hash
<< NAME_HASH_SHIFT
) ^
1264 (hash
>> (8*sizeof(hash
) - NAME_HASH_SHIFT
)) ^
1268 if (entry
->e_value_block
== 0 && entry
->e_value_size
!= 0) {
1269 __le32
*value
= (__le32
*)((char *)header
+
1270 le16_to_cpu(entry
->e_value_offs
));
1271 for (n
= (le32_to_cpu(entry
->e_value_size
) +
1272 EXT3_XATTR_ROUND
) >> EXT3_XATTR_PAD_BITS
; n
; n
--) {
1273 hash
= (hash
<< VALUE_HASH_SHIFT
) ^
1274 (hash
>> (8*sizeof(hash
) - VALUE_HASH_SHIFT
)) ^
1275 le32_to_cpu(*value
++);
1278 entry
->e_hash
= cpu_to_le32(hash
);
1281 #undef NAME_HASH_SHIFT
1282 #undef VALUE_HASH_SHIFT
1284 #define BLOCK_HASH_SHIFT 16
1287 * ext3_xattr_rehash()
1289 * Re-compute the extended attribute hash value after an entry has changed.
1291 static void ext3_xattr_rehash(struct ext3_xattr_header
*header
,
1292 struct ext3_xattr_entry
*entry
)
1294 struct ext3_xattr_entry
*here
;
1297 ext3_xattr_hash_entry(header
, entry
);
1298 here
= ENTRY(header
+1);
1299 while (!IS_LAST_ENTRY(here
)) {
1300 if (!here
->e_hash
) {
1301 /* Block is not shared if an entry's hash value == 0 */
1305 hash
= (hash
<< BLOCK_HASH_SHIFT
) ^
1306 (hash
>> (8*sizeof(hash
) - BLOCK_HASH_SHIFT
)) ^
1307 le32_to_cpu(here
->e_hash
);
1308 here
= EXT3_XATTR_NEXT(here
);
1310 header
->h_hash
= cpu_to_le32(hash
);
1313 #undef BLOCK_HASH_SHIFT
1316 init_ext3_xattr(void)
1318 ext3_xattr_cache
= mb_cache_create("ext3_xattr", 6);
1319 if (!ext3_xattr_cache
)
1325 exit_ext3_xattr(void)
1327 if (ext3_xattr_cache
)
1328 mb_cache_destroy(ext3_xattr_cache
);
1329 ext3_xattr_cache
= NULL
;