2 * linux/fs/ext4/xattr.c
4 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
6 * Fix by Harrison Xing <harrison@mountainviewdata.com>.
7 * Ext4 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 * EXT4_I(inode)->i_file_acl is protected by EXT4_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
53 #include <linux/init.h>
55 #include <linux/slab.h>
56 #include <linux/mbcache.h>
57 #include <linux/quotaops.h>
58 #include <linux/rwsem.h>
59 #include "ext4_jbd2.h"
64 #define BHDR(bh) ((struct ext4_xattr_header *)((bh)->b_data))
65 #define ENTRY(ptr) ((struct ext4_xattr_entry *)(ptr))
66 #define BFIRST(bh) ENTRY(BHDR(bh)+1)
67 #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
69 #ifdef EXT4_XATTR_DEBUG
70 # define ea_idebug(inode, f...) do { \
71 printk(KERN_DEBUG "inode %s:%lu: ", \
72 inode->i_sb->s_id, inode->i_ino); \
76 # define ea_bdebug(bh, f...) do { \
77 char b[BDEVNAME_SIZE]; \
78 printk(KERN_DEBUG "block %s:%lu: ", \
79 bdevname(bh->b_bdev, b), \
80 (unsigned long) bh->b_blocknr); \
85 # define ea_idebug(f...)
86 # define ea_bdebug(f...)
89 static void ext4_xattr_cache_insert(struct buffer_head
*);
90 static struct buffer_head
*ext4_xattr_cache_find(struct inode
*,
91 struct ext4_xattr_header
*,
92 struct mb_cache_entry
**);
93 static void ext4_xattr_rehash(struct ext4_xattr_header
*,
94 struct ext4_xattr_entry
*);
95 static int ext4_xattr_list(struct inode
*inode
, char *buffer
,
98 static struct mb_cache
*ext4_xattr_cache
;
100 static struct xattr_handler
*ext4_xattr_handler_map
[] = {
101 [EXT4_XATTR_INDEX_USER
] = &ext4_xattr_user_handler
,
102 #ifdef CONFIG_EXT4_FS_POSIX_ACL
103 [EXT4_XATTR_INDEX_POSIX_ACL_ACCESS
] = &ext4_xattr_acl_access_handler
,
104 [EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT
] = &ext4_xattr_acl_default_handler
,
106 [EXT4_XATTR_INDEX_TRUSTED
] = &ext4_xattr_trusted_handler
,
107 #ifdef CONFIG_EXT4_FS_SECURITY
108 [EXT4_XATTR_INDEX_SECURITY
] = &ext4_xattr_security_handler
,
112 struct xattr_handler
*ext4_xattr_handlers
[] = {
113 &ext4_xattr_user_handler
,
114 &ext4_xattr_trusted_handler
,
115 #ifdef CONFIG_EXT4_FS_POSIX_ACL
116 &ext4_xattr_acl_access_handler
,
117 &ext4_xattr_acl_default_handler
,
119 #ifdef CONFIG_EXT4_FS_SECURITY
120 &ext4_xattr_security_handler
,
125 static inline struct xattr_handler
*
126 ext4_xattr_handler(int name_index
)
128 struct xattr_handler
*handler
= NULL
;
130 if (name_index
> 0 && name_index
< ARRAY_SIZE(ext4_xattr_handler_map
))
131 handler
= ext4_xattr_handler_map
[name_index
];
136 * Inode operation listxattr()
138 * dentry->d_inode->i_mutex: don't care
141 ext4_listxattr(struct dentry
*dentry
, char *buffer
, size_t size
)
143 return ext4_xattr_list(dentry
->d_inode
, buffer
, size
);
147 ext4_xattr_check_names(struct ext4_xattr_entry
*entry
, void *end
)
149 while (!IS_LAST_ENTRY(entry
)) {
150 struct ext4_xattr_entry
*next
= EXT4_XATTR_NEXT(entry
);
151 if ((void *)next
>= end
)
159 ext4_xattr_check_block(struct buffer_head
*bh
)
163 if (BHDR(bh
)->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
) ||
164 BHDR(bh
)->h_blocks
!= cpu_to_le32(1))
166 error
= ext4_xattr_check_names(BFIRST(bh
), bh
->b_data
+ bh
->b_size
);
171 ext4_xattr_check_entry(struct ext4_xattr_entry
*entry
, size_t size
)
173 size_t value_size
= le32_to_cpu(entry
->e_value_size
);
175 if (entry
->e_value_block
!= 0 || value_size
> size
||
176 le16_to_cpu(entry
->e_value_offs
) + value_size
> size
)
182 ext4_xattr_find_entry(struct ext4_xattr_entry
**pentry
, int name_index
,
183 const char *name
, size_t size
, int sorted
)
185 struct ext4_xattr_entry
*entry
;
191 name_len
= strlen(name
);
193 for (; !IS_LAST_ENTRY(entry
); entry
= EXT4_XATTR_NEXT(entry
)) {
194 cmp
= name_index
- entry
->e_name_index
;
196 cmp
= name_len
- entry
->e_name_len
;
198 cmp
= memcmp(name
, entry
->e_name
, name_len
);
199 if (cmp
<= 0 && (sorted
|| cmp
== 0))
203 if (!cmp
&& ext4_xattr_check_entry(entry
, size
))
205 return cmp
? -ENODATA
: 0;
209 ext4_xattr_block_get(struct inode
*inode
, int name_index
, const char *name
,
210 void *buffer
, size_t buffer_size
)
212 struct buffer_head
*bh
= NULL
;
213 struct ext4_xattr_entry
*entry
;
217 ea_idebug(inode
, "name=%d.%s, buffer=%p, buffer_size=%ld",
218 name_index
, name
, buffer
, (long)buffer_size
);
221 if (!EXT4_I(inode
)->i_file_acl
)
223 ea_idebug(inode
, "reading block %u", EXT4_I(inode
)->i_file_acl
);
224 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
227 ea_bdebug(bh
, "b_count=%d, refcount=%d",
228 atomic_read(&(bh
->b_count
)), le32_to_cpu(BHDR(bh
)->h_refcount
));
229 if (ext4_xattr_check_block(bh
)) {
230 bad_block
: ext4_error(inode
->i_sb
, __func__
,
231 "inode %lu: bad block %llu", inode
->i_ino
,
232 EXT4_I(inode
)->i_file_acl
);
236 ext4_xattr_cache_insert(bh
);
238 error
= ext4_xattr_find_entry(&entry
, name_index
, name
, bh
->b_size
, 1);
243 size
= le32_to_cpu(entry
->e_value_size
);
246 if (size
> buffer_size
)
248 memcpy(buffer
, bh
->b_data
+ le16_to_cpu(entry
->e_value_offs
),
259 ext4_xattr_ibody_get(struct inode
*inode
, int name_index
, const char *name
,
260 void *buffer
, size_t buffer_size
)
262 struct ext4_xattr_ibody_header
*header
;
263 struct ext4_xattr_entry
*entry
;
264 struct ext4_inode
*raw_inode
;
265 struct ext4_iloc iloc
;
270 if (!(EXT4_I(inode
)->i_state
& EXT4_STATE_XATTR
))
272 error
= ext4_get_inode_loc(inode
, &iloc
);
275 raw_inode
= ext4_raw_inode(&iloc
);
276 header
= IHDR(inode
, raw_inode
);
277 entry
= IFIRST(header
);
278 end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
279 error
= ext4_xattr_check_names(entry
, end
);
282 error
= ext4_xattr_find_entry(&entry
, name_index
, name
,
283 end
- (void *)entry
, 0);
286 size
= le32_to_cpu(entry
->e_value_size
);
289 if (size
> buffer_size
)
291 memcpy(buffer
, (void *)IFIRST(header
) +
292 le16_to_cpu(entry
->e_value_offs
), size
);
304 * Copy an extended attribute into the buffer
305 * provided, or compute the buffer size required.
306 * Buffer is NULL to compute the size of the buffer required.
308 * Returns a negative error number on failure, or the number of bytes
309 * used / required on success.
312 ext4_xattr_get(struct inode
*inode
, int name_index
, const char *name
,
313 void *buffer
, size_t buffer_size
)
317 down_read(&EXT4_I(inode
)->xattr_sem
);
318 error
= ext4_xattr_ibody_get(inode
, name_index
, name
, buffer
,
320 if (error
== -ENODATA
)
321 error
= ext4_xattr_block_get(inode
, name_index
, name
, buffer
,
323 up_read(&EXT4_I(inode
)->xattr_sem
);
328 ext4_xattr_list_entries(struct inode
*inode
, struct ext4_xattr_entry
*entry
,
329 char *buffer
, size_t buffer_size
)
331 size_t rest
= buffer_size
;
333 for (; !IS_LAST_ENTRY(entry
); entry
= EXT4_XATTR_NEXT(entry
)) {
334 struct xattr_handler
*handler
=
335 ext4_xattr_handler(entry
->e_name_index
);
338 size_t size
= handler
->list(inode
, buffer
, rest
,
349 return buffer_size
- rest
;
353 ext4_xattr_block_list(struct inode
*inode
, char *buffer
, size_t buffer_size
)
355 struct buffer_head
*bh
= NULL
;
358 ea_idebug(inode
, "buffer=%p, buffer_size=%ld",
359 buffer
, (long)buffer_size
);
362 if (!EXT4_I(inode
)->i_file_acl
)
364 ea_idebug(inode
, "reading block %u", EXT4_I(inode
)->i_file_acl
);
365 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
369 ea_bdebug(bh
, "b_count=%d, refcount=%d",
370 atomic_read(&(bh
->b_count
)), le32_to_cpu(BHDR(bh
)->h_refcount
));
371 if (ext4_xattr_check_block(bh
)) {
372 ext4_error(inode
->i_sb
, __func__
,
373 "inode %lu: bad block %llu", inode
->i_ino
,
374 EXT4_I(inode
)->i_file_acl
);
378 ext4_xattr_cache_insert(bh
);
379 error
= ext4_xattr_list_entries(inode
, BFIRST(bh
), buffer
, buffer_size
);
388 ext4_xattr_ibody_list(struct inode
*inode
, char *buffer
, size_t buffer_size
)
390 struct ext4_xattr_ibody_header
*header
;
391 struct ext4_inode
*raw_inode
;
392 struct ext4_iloc iloc
;
396 if (!(EXT4_I(inode
)->i_state
& EXT4_STATE_XATTR
))
398 error
= ext4_get_inode_loc(inode
, &iloc
);
401 raw_inode
= ext4_raw_inode(&iloc
);
402 header
= IHDR(inode
, raw_inode
);
403 end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
404 error
= ext4_xattr_check_names(IFIRST(header
), end
);
407 error
= ext4_xattr_list_entries(inode
, IFIRST(header
),
408 buffer
, buffer_size
);
418 * Copy a list of attribute names into the buffer
419 * provided, or compute the buffer size required.
420 * Buffer is NULL to compute the size of the buffer required.
422 * Returns a negative error number on failure, or the number of bytes
423 * used / required on success.
426 ext4_xattr_list(struct inode
*inode
, char *buffer
, size_t buffer_size
)
428 int i_error
, b_error
;
430 down_read(&EXT4_I(inode
)->xattr_sem
);
431 i_error
= ext4_xattr_ibody_list(inode
, buffer
, buffer_size
);
437 buffer_size
-= i_error
;
439 b_error
= ext4_xattr_block_list(inode
, buffer
, buffer_size
);
443 up_read(&EXT4_I(inode
)->xattr_sem
);
444 return i_error
+ b_error
;
448 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is
451 static void ext4_xattr_update_super_block(handle_t
*handle
,
452 struct super_block
*sb
)
454 if (EXT4_HAS_COMPAT_FEATURE(sb
, EXT4_FEATURE_COMPAT_EXT_ATTR
))
457 if (ext4_journal_get_write_access(handle
, EXT4_SB(sb
)->s_sbh
) == 0) {
458 EXT4_SET_COMPAT_FEATURE(sb
, EXT4_FEATURE_COMPAT_EXT_ATTR
);
460 ext4_journal_dirty_metadata(handle
, EXT4_SB(sb
)->s_sbh
);
465 * Release the xattr block BH: If the reference count is > 1, decrement
466 * it; otherwise free the block.
469 ext4_xattr_release_block(handle_t
*handle
, struct inode
*inode
,
470 struct buffer_head
*bh
)
472 struct mb_cache_entry
*ce
= NULL
;
475 ce
= mb_cache_entry_get(ext4_xattr_cache
, bh
->b_bdev
, bh
->b_blocknr
);
476 error
= ext4_journal_get_write_access(handle
, bh
);
481 if (BHDR(bh
)->h_refcount
== cpu_to_le32(1)) {
482 ea_bdebug(bh
, "refcount now=0; freeing");
484 mb_cache_entry_free(ce
);
485 ext4_free_blocks(handle
, inode
, bh
->b_blocknr
, 1, 1);
487 ext4_forget(handle
, 1, inode
, bh
, bh
->b_blocknr
);
489 le32_add_cpu(&BHDR(bh
)->h_refcount
, -1);
490 error
= ext4_journal_dirty_metadata(handle
, bh
);
493 DQUOT_FREE_BLOCK(inode
, 1);
494 ea_bdebug(bh
, "refcount now=%d; releasing",
495 le32_to_cpu(BHDR(bh
)->h_refcount
));
497 mb_cache_entry_release(ce
);
501 ext4_std_error(inode
->i_sb
, error
);
506 * Find the available free space for EAs. This also returns the total number of
507 * bytes used by EA entries.
509 static size_t ext4_xattr_free_space(struct ext4_xattr_entry
*last
,
510 size_t *min_offs
, void *base
, int *total
)
512 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
513 *total
+= EXT4_XATTR_LEN(last
->e_name_len
);
514 if (!last
->e_value_block
&& last
->e_value_size
) {
515 size_t offs
= le16_to_cpu(last
->e_value_offs
);
516 if (offs
< *min_offs
)
520 return (*min_offs
- ((void *)last
- base
) - sizeof(__u32
));
523 struct ext4_xattr_info
{
530 struct ext4_xattr_search
{
531 struct ext4_xattr_entry
*first
;
534 struct ext4_xattr_entry
*here
;
539 ext4_xattr_set_entry(struct ext4_xattr_info
*i
, struct ext4_xattr_search
*s
)
541 struct ext4_xattr_entry
*last
;
542 size_t free
, min_offs
= s
->end
- s
->base
, name_len
= strlen(i
->name
);
544 /* Compute min_offs and last. */
546 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
547 if (!last
->e_value_block
&& last
->e_value_size
) {
548 size_t offs
= le16_to_cpu(last
->e_value_offs
);
553 free
= min_offs
- ((void *)last
- s
->base
) - sizeof(__u32
);
555 if (!s
->here
->e_value_block
&& s
->here
->e_value_size
) {
556 size_t size
= le32_to_cpu(s
->here
->e_value_size
);
557 free
+= EXT4_XATTR_SIZE(size
);
559 free
+= EXT4_XATTR_LEN(name_len
);
562 if (free
< EXT4_XATTR_SIZE(i
->value_len
) ||
563 free
< EXT4_XATTR_LEN(name_len
) +
564 EXT4_XATTR_SIZE(i
->value_len
))
568 if (i
->value
&& s
->not_found
) {
569 /* Insert the new name. */
570 size_t size
= EXT4_XATTR_LEN(name_len
);
571 size_t rest
= (void *)last
- (void *)s
->here
+ sizeof(__u32
);
572 memmove((void *)s
->here
+ size
, s
->here
, rest
);
573 memset(s
->here
, 0, size
);
574 s
->here
->e_name_index
= i
->name_index
;
575 s
->here
->e_name_len
= name_len
;
576 memcpy(s
->here
->e_name
, i
->name
, name_len
);
578 if (!s
->here
->e_value_block
&& s
->here
->e_value_size
) {
579 void *first_val
= s
->base
+ min_offs
;
580 size_t offs
= le16_to_cpu(s
->here
->e_value_offs
);
581 void *val
= s
->base
+ offs
;
582 size_t size
= EXT4_XATTR_SIZE(
583 le32_to_cpu(s
->here
->e_value_size
));
585 if (i
->value
&& size
== EXT4_XATTR_SIZE(i
->value_len
)) {
586 /* The old and the new value have the same
587 size. Just replace. */
588 s
->here
->e_value_size
=
589 cpu_to_le32(i
->value_len
);
590 memset(val
+ size
- EXT4_XATTR_PAD
, 0,
591 EXT4_XATTR_PAD
); /* Clear pad bytes. */
592 memcpy(val
, i
->value
, i
->value_len
);
596 /* Remove the old value. */
597 memmove(first_val
+ size
, first_val
, val
- first_val
);
598 memset(first_val
, 0, size
);
599 s
->here
->e_value_size
= 0;
600 s
->here
->e_value_offs
= 0;
603 /* Adjust all value offsets. */
605 while (!IS_LAST_ENTRY(last
)) {
606 size_t o
= le16_to_cpu(last
->e_value_offs
);
607 if (!last
->e_value_block
&&
608 last
->e_value_size
&& o
< offs
)
610 cpu_to_le16(o
+ size
);
611 last
= EXT4_XATTR_NEXT(last
);
615 /* Remove the old name. */
616 size_t size
= EXT4_XATTR_LEN(name_len
);
617 last
= ENTRY((void *)last
- size
);
618 memmove(s
->here
, (void *)s
->here
+ size
,
619 (void *)last
- (void *)s
->here
+ sizeof(__u32
));
620 memset(last
, 0, size
);
625 /* Insert the new value. */
626 s
->here
->e_value_size
= cpu_to_le32(i
->value_len
);
628 size_t size
= EXT4_XATTR_SIZE(i
->value_len
);
629 void *val
= s
->base
+ min_offs
- size
;
630 s
->here
->e_value_offs
= cpu_to_le16(min_offs
- size
);
631 memset(val
+ size
- EXT4_XATTR_PAD
, 0,
632 EXT4_XATTR_PAD
); /* Clear the pad bytes. */
633 memcpy(val
, i
->value
, i
->value_len
);
639 struct ext4_xattr_block_find
{
640 struct ext4_xattr_search s
;
641 struct buffer_head
*bh
;
645 ext4_xattr_block_find(struct inode
*inode
, struct ext4_xattr_info
*i
,
646 struct ext4_xattr_block_find
*bs
)
648 struct super_block
*sb
= inode
->i_sb
;
651 ea_idebug(inode
, "name=%d.%s, value=%p, value_len=%ld",
652 i
->name_index
, i
->name
, i
->value
, (long)i
->value_len
);
654 if (EXT4_I(inode
)->i_file_acl
) {
655 /* The inode already has an extended attribute block. */
656 bs
->bh
= sb_bread(sb
, EXT4_I(inode
)->i_file_acl
);
660 ea_bdebug(bs
->bh
, "b_count=%d, refcount=%d",
661 atomic_read(&(bs
->bh
->b_count
)),
662 le32_to_cpu(BHDR(bs
->bh
)->h_refcount
));
663 if (ext4_xattr_check_block(bs
->bh
)) {
664 ext4_error(sb
, __func__
,
665 "inode %lu: bad block %llu", inode
->i_ino
,
666 EXT4_I(inode
)->i_file_acl
);
670 /* Find the named attribute. */
671 bs
->s
.base
= BHDR(bs
->bh
);
672 bs
->s
.first
= BFIRST(bs
->bh
);
673 bs
->s
.end
= bs
->bh
->b_data
+ bs
->bh
->b_size
;
674 bs
->s
.here
= bs
->s
.first
;
675 error
= ext4_xattr_find_entry(&bs
->s
.here
, i
->name_index
,
676 i
->name
, bs
->bh
->b_size
, 1);
677 if (error
&& error
!= -ENODATA
)
679 bs
->s
.not_found
= error
;
688 ext4_xattr_block_set(handle_t
*handle
, struct inode
*inode
,
689 struct ext4_xattr_info
*i
,
690 struct ext4_xattr_block_find
*bs
)
692 unsigned long count
= 1;
693 struct super_block
*sb
= inode
->i_sb
;
694 struct buffer_head
*new_bh
= NULL
;
695 struct ext4_xattr_search
*s
= &bs
->s
;
696 struct mb_cache_entry
*ce
= NULL
;
699 #define header(x) ((struct ext4_xattr_header *)(x))
701 if (i
->value
&& i
->value_len
> sb
->s_blocksize
)
704 ce
= mb_cache_entry_get(ext4_xattr_cache
, bs
->bh
->b_bdev
,
706 error
= ext4_journal_get_write_access(handle
, bs
->bh
);
711 if (header(s
->base
)->h_refcount
== cpu_to_le32(1)) {
713 mb_cache_entry_free(ce
);
716 ea_bdebug(bs
->bh
, "modifying in-place");
717 error
= ext4_xattr_set_entry(i
, s
);
719 if (!IS_LAST_ENTRY(s
->first
))
720 ext4_xattr_rehash(header(s
->base
),
722 ext4_xattr_cache_insert(bs
->bh
);
724 unlock_buffer(bs
->bh
);
728 error
= ext4_journal_dirty_metadata(handle
,
734 int offset
= (char *)s
->here
- bs
->bh
->b_data
;
736 unlock_buffer(bs
->bh
);
737 jbd2_journal_release_buffer(handle
, bs
->bh
);
739 mb_cache_entry_release(ce
);
742 ea_bdebug(bs
->bh
, "cloning");
743 s
->base
= kmalloc(bs
->bh
->b_size
, GFP_NOFS
);
747 memcpy(s
->base
, BHDR(bs
->bh
), bs
->bh
->b_size
);
748 s
->first
= ENTRY(header(s
->base
)+1);
749 header(s
->base
)->h_refcount
= cpu_to_le32(1);
750 s
->here
= ENTRY(s
->base
+ offset
);
751 s
->end
= s
->base
+ bs
->bh
->b_size
;
754 /* Allocate a buffer where we construct the new block. */
755 s
->base
= kzalloc(sb
->s_blocksize
, GFP_NOFS
);
756 /* assert(header == s->base) */
760 header(s
->base
)->h_magic
= cpu_to_le32(EXT4_XATTR_MAGIC
);
761 header(s
->base
)->h_blocks
= cpu_to_le32(1);
762 header(s
->base
)->h_refcount
= cpu_to_le32(1);
763 s
->first
= ENTRY(header(s
->base
)+1);
764 s
->here
= ENTRY(header(s
->base
)+1);
765 s
->end
= s
->base
+ sb
->s_blocksize
;
768 error
= ext4_xattr_set_entry(i
, s
);
773 if (!IS_LAST_ENTRY(s
->first
))
774 ext4_xattr_rehash(header(s
->base
), s
->here
);
777 if (!IS_LAST_ENTRY(s
->first
)) {
778 new_bh
= ext4_xattr_cache_find(inode
, header(s
->base
), &ce
);
780 /* We found an identical block in the cache. */
781 if (new_bh
== bs
->bh
)
782 ea_bdebug(new_bh
, "keeping");
784 /* The old block is released after updating
787 if (DQUOT_ALLOC_BLOCK(inode
, 1))
789 error
= ext4_journal_get_write_access(handle
,
794 le32_add_cpu(&BHDR(new_bh
)->h_refcount
, 1);
795 ea_bdebug(new_bh
, "reusing; refcount now=%d",
796 le32_to_cpu(BHDR(new_bh
)->h_refcount
));
797 unlock_buffer(new_bh
);
798 error
= ext4_journal_dirty_metadata(handle
,
803 mb_cache_entry_release(ce
);
805 } else if (bs
->bh
&& s
->base
== bs
->bh
->b_data
) {
806 /* We were modifying this block in-place. */
807 ea_bdebug(bs
->bh
, "keeping this block");
811 /* We need to allocate a new block */
812 ext4_fsblk_t goal
= ext4_group_first_block_no(sb
,
813 EXT4_I(inode
)->i_block_group
);
814 ext4_fsblk_t block
= ext4_new_meta_blocks(handle
, inode
,
815 goal
, &count
, &error
);
818 ea_idebug(inode
, "creating block %d", block
);
820 new_bh
= sb_getblk(sb
, block
);
823 ext4_free_blocks(handle
, inode
, block
, 1, 1);
828 error
= ext4_journal_get_create_access(handle
, new_bh
);
830 unlock_buffer(new_bh
);
833 memcpy(new_bh
->b_data
, s
->base
, new_bh
->b_size
);
834 set_buffer_uptodate(new_bh
);
835 unlock_buffer(new_bh
);
836 ext4_xattr_cache_insert(new_bh
);
837 error
= ext4_journal_dirty_metadata(handle
, new_bh
);
843 /* Update the inode. */
844 EXT4_I(inode
)->i_file_acl
= new_bh
? new_bh
->b_blocknr
: 0;
846 /* Drop the previous xattr block. */
847 if (bs
->bh
&& bs
->bh
!= new_bh
)
848 ext4_xattr_release_block(handle
, inode
, bs
->bh
);
853 mb_cache_entry_release(ce
);
855 if (!(bs
->bh
&& s
->base
== bs
->bh
->b_data
))
861 DQUOT_FREE_BLOCK(inode
, 1);
865 ext4_error(inode
->i_sb
, __func__
,
866 "inode %lu: bad block %llu", inode
->i_ino
,
867 EXT4_I(inode
)->i_file_acl
);
873 struct ext4_xattr_ibody_find
{
874 struct ext4_xattr_search s
;
875 struct ext4_iloc iloc
;
879 ext4_xattr_ibody_find(struct inode
*inode
, struct ext4_xattr_info
*i
,
880 struct ext4_xattr_ibody_find
*is
)
882 struct ext4_xattr_ibody_header
*header
;
883 struct ext4_inode
*raw_inode
;
886 if (EXT4_I(inode
)->i_extra_isize
== 0)
888 raw_inode
= ext4_raw_inode(&is
->iloc
);
889 header
= IHDR(inode
, raw_inode
);
890 is
->s
.base
= is
->s
.first
= IFIRST(header
);
891 is
->s
.here
= is
->s
.first
;
892 is
->s
.end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
893 if (EXT4_I(inode
)->i_state
& EXT4_STATE_XATTR
) {
894 error
= ext4_xattr_check_names(IFIRST(header
), is
->s
.end
);
897 /* Find the named attribute. */
898 error
= ext4_xattr_find_entry(&is
->s
.here
, i
->name_index
,
900 (void *)is
->s
.base
, 0);
901 if (error
&& error
!= -ENODATA
)
903 is
->s
.not_found
= error
;
909 ext4_xattr_ibody_set(handle_t
*handle
, struct inode
*inode
,
910 struct ext4_xattr_info
*i
,
911 struct ext4_xattr_ibody_find
*is
)
913 struct ext4_xattr_ibody_header
*header
;
914 struct ext4_xattr_search
*s
= &is
->s
;
917 if (EXT4_I(inode
)->i_extra_isize
== 0)
919 error
= ext4_xattr_set_entry(i
, s
);
922 header
= IHDR(inode
, ext4_raw_inode(&is
->iloc
));
923 if (!IS_LAST_ENTRY(s
->first
)) {
924 header
->h_magic
= cpu_to_le32(EXT4_XATTR_MAGIC
);
925 EXT4_I(inode
)->i_state
|= EXT4_STATE_XATTR
;
927 header
->h_magic
= cpu_to_le32(0);
928 EXT4_I(inode
)->i_state
&= ~EXT4_STATE_XATTR
;
934 * ext4_xattr_set_handle()
936 * Create, replace or remove an extended attribute for this inode. Buffer
937 * is NULL to remove an existing extended attribute, and non-NULL to
938 * either replace an existing extended attribute, or create a new extended
939 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
940 * specify that an extended attribute must exist and must not exist
941 * previous to the call, respectively.
943 * Returns 0, or a negative error number on failure.
946 ext4_xattr_set_handle(handle_t
*handle
, struct inode
*inode
, int name_index
,
947 const char *name
, const void *value
, size_t value_len
,
950 struct ext4_xattr_info i
= {
951 .name_index
= name_index
,
954 .value_len
= value_len
,
957 struct ext4_xattr_ibody_find is
= {
958 .s
= { .not_found
= -ENODATA
, },
960 struct ext4_xattr_block_find bs
= {
961 .s
= { .not_found
= -ENODATA
, },
963 unsigned long no_expand
;
968 if (strlen(name
) > 255)
970 down_write(&EXT4_I(inode
)->xattr_sem
);
971 no_expand
= EXT4_I(inode
)->i_state
& EXT4_STATE_NO_EXPAND
;
972 EXT4_I(inode
)->i_state
|= EXT4_STATE_NO_EXPAND
;
974 error
= ext4_get_inode_loc(inode
, &is
.iloc
);
978 if (EXT4_I(inode
)->i_state
& EXT4_STATE_NEW
) {
979 struct ext4_inode
*raw_inode
= ext4_raw_inode(&is
.iloc
);
980 memset(raw_inode
, 0, EXT4_SB(inode
->i_sb
)->s_inode_size
);
981 EXT4_I(inode
)->i_state
&= ~EXT4_STATE_NEW
;
984 error
= ext4_xattr_ibody_find(inode
, &i
, &is
);
988 error
= ext4_xattr_block_find(inode
, &i
, &bs
);
991 if (is
.s
.not_found
&& bs
.s
.not_found
) {
993 if (flags
& XATTR_REPLACE
)
1000 if (flags
& XATTR_CREATE
)
1003 error
= ext4_journal_get_write_access(handle
, is
.iloc
.bh
);
1007 if (!is
.s
.not_found
)
1008 error
= ext4_xattr_ibody_set(handle
, inode
, &i
, &is
);
1009 else if (!bs
.s
.not_found
)
1010 error
= ext4_xattr_block_set(handle
, inode
, &i
, &bs
);
1012 error
= ext4_xattr_ibody_set(handle
, inode
, &i
, &is
);
1013 if (!error
&& !bs
.s
.not_found
) {
1015 error
= ext4_xattr_block_set(handle
, inode
, &i
, &bs
);
1016 } else if (error
== -ENOSPC
) {
1017 if (EXT4_I(inode
)->i_file_acl
&& !bs
.s
.base
) {
1018 error
= ext4_xattr_block_find(inode
, &i
, &bs
);
1022 error
= ext4_xattr_block_set(handle
, inode
, &i
, &bs
);
1025 if (!is
.s
.not_found
) {
1027 error
= ext4_xattr_ibody_set(handle
, inode
, &i
,
1033 ext4_xattr_update_super_block(handle
, inode
->i_sb
);
1034 inode
->i_ctime
= ext4_current_time(inode
);
1036 EXT4_I(inode
)->i_state
&= ~EXT4_STATE_NO_EXPAND
;
1037 error
= ext4_mark_iloc_dirty(handle
, inode
, &is
.iloc
);
1039 * The bh is consumed by ext4_mark_iloc_dirty, even with
1051 EXT4_I(inode
)->i_state
&= ~EXT4_STATE_NO_EXPAND
;
1052 up_write(&EXT4_I(inode
)->xattr_sem
);
1059 * Like ext4_xattr_set_handle, but start from an inode. This extended
1060 * attribute modification is a filesystem transaction by itself.
1062 * Returns 0, or a negative error number on failure.
1065 ext4_xattr_set(struct inode
*inode
, int name_index
, const char *name
,
1066 const void *value
, size_t value_len
, int flags
)
1069 int error
, retries
= 0;
1072 handle
= ext4_journal_start(inode
, EXT4_DATA_TRANS_BLOCKS(inode
->i_sb
));
1073 if (IS_ERR(handle
)) {
1074 error
= PTR_ERR(handle
);
1078 error
= ext4_xattr_set_handle(handle
, inode
, name_index
, name
,
1079 value
, value_len
, flags
);
1080 error2
= ext4_journal_stop(handle
);
1081 if (error
== -ENOSPC
&&
1082 ext4_should_retry_alloc(inode
->i_sb
, &retries
))
1092 * Shift the EA entries in the inode to create space for the increased
1095 static void ext4_xattr_shift_entries(struct ext4_xattr_entry
*entry
,
1096 int value_offs_shift
, void *to
,
1097 void *from
, size_t n
, int blocksize
)
1099 struct ext4_xattr_entry
*last
= entry
;
1102 /* Adjust the value offsets of the entries */
1103 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
1104 if (!last
->e_value_block
&& last
->e_value_size
) {
1105 new_offs
= le16_to_cpu(last
->e_value_offs
) +
1107 BUG_ON(new_offs
+ le32_to_cpu(last
->e_value_size
)
1109 last
->e_value_offs
= cpu_to_le16(new_offs
);
1112 /* Shift the entries by n bytes */
1113 memmove(to
, from
, n
);
1117 * Expand an inode by new_extra_isize bytes when EAs are present.
1118 * Returns 0 on success or negative error number on failure.
1120 int ext4_expand_extra_isize_ea(struct inode
*inode
, int new_extra_isize
,
1121 struct ext4_inode
*raw_inode
, handle_t
*handle
)
1123 struct ext4_xattr_ibody_header
*header
;
1124 struct ext4_xattr_entry
*entry
, *last
, *first
;
1125 struct buffer_head
*bh
= NULL
;
1126 struct ext4_xattr_ibody_find
*is
= NULL
;
1127 struct ext4_xattr_block_find
*bs
= NULL
;
1128 char *buffer
= NULL
, *b_entry_name
= NULL
;
1129 size_t min_offs
, free
;
1130 int total_ino
, total_blk
;
1131 void *base
, *start
, *end
;
1132 int extra_isize
= 0, error
= 0, tried_min_extra_isize
= 0;
1133 int s_min_extra_isize
= le16_to_cpu(EXT4_SB(inode
->i_sb
)->s_es
->s_min_extra_isize
);
1135 down_write(&EXT4_I(inode
)->xattr_sem
);
1137 if (EXT4_I(inode
)->i_extra_isize
>= new_extra_isize
) {
1138 up_write(&EXT4_I(inode
)->xattr_sem
);
1142 header
= IHDR(inode
, raw_inode
);
1143 entry
= IFIRST(header
);
1146 * Check if enough free space is available in the inode to shift the
1147 * entries ahead by new_extra_isize.
1150 base
= start
= entry
;
1151 end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
1152 min_offs
= end
- base
;
1154 total_ino
= sizeof(struct ext4_xattr_ibody_header
);
1156 free
= ext4_xattr_free_space(last
, &min_offs
, base
, &total_ino
);
1157 if (free
>= new_extra_isize
) {
1158 entry
= IFIRST(header
);
1159 ext4_xattr_shift_entries(entry
, EXT4_I(inode
)->i_extra_isize
1160 - new_extra_isize
, (void *)raw_inode
+
1161 EXT4_GOOD_OLD_INODE_SIZE
+ new_extra_isize
,
1162 (void *)header
, total_ino
,
1163 inode
->i_sb
->s_blocksize
);
1164 EXT4_I(inode
)->i_extra_isize
= new_extra_isize
;
1170 * Enough free space isn't available in the inode, check if
1171 * EA block can hold new_extra_isize bytes.
1173 if (EXT4_I(inode
)->i_file_acl
) {
1174 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
1178 if (ext4_xattr_check_block(bh
)) {
1179 ext4_error(inode
->i_sb
, __func__
,
1180 "inode %lu: bad block %llu", inode
->i_ino
,
1181 EXT4_I(inode
)->i_file_acl
);
1187 end
= bh
->b_data
+ bh
->b_size
;
1188 min_offs
= end
- base
;
1189 free
= ext4_xattr_free_space(first
, &min_offs
, base
,
1191 if (free
< new_extra_isize
) {
1192 if (!tried_min_extra_isize
&& s_min_extra_isize
) {
1193 tried_min_extra_isize
++;
1194 new_extra_isize
= s_min_extra_isize
;
1202 free
= inode
->i_sb
->s_blocksize
;
1205 while (new_extra_isize
> 0) {
1206 size_t offs
, size
, entry_size
;
1207 struct ext4_xattr_entry
*small_entry
= NULL
;
1208 struct ext4_xattr_info i
= {
1212 unsigned int total_size
; /* EA entry size + value size */
1213 unsigned int shift_bytes
; /* No. of bytes to shift EAs by? */
1214 unsigned int min_total_size
= ~0U;
1216 is
= kzalloc(sizeof(struct ext4_xattr_ibody_find
), GFP_NOFS
);
1217 bs
= kzalloc(sizeof(struct ext4_xattr_block_find
), GFP_NOFS
);
1223 is
->s
.not_found
= -ENODATA
;
1224 bs
->s
.not_found
= -ENODATA
;
1228 last
= IFIRST(header
);
1229 /* Find the entry best suited to be pushed into EA block */
1231 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
1233 EXT4_XATTR_SIZE(le32_to_cpu(last
->e_value_size
)) +
1234 EXT4_XATTR_LEN(last
->e_name_len
);
1235 if (total_size
<= free
&& total_size
< min_total_size
) {
1236 if (total_size
< new_extra_isize
) {
1240 min_total_size
= total_size
;
1245 if (entry
== NULL
) {
1247 entry
= small_entry
;
1249 if (!tried_min_extra_isize
&&
1250 s_min_extra_isize
) {
1251 tried_min_extra_isize
++;
1252 new_extra_isize
= s_min_extra_isize
;
1259 offs
= le16_to_cpu(entry
->e_value_offs
);
1260 size
= le32_to_cpu(entry
->e_value_size
);
1261 entry_size
= EXT4_XATTR_LEN(entry
->e_name_len
);
1262 i
.name_index
= entry
->e_name_index
,
1263 buffer
= kmalloc(EXT4_XATTR_SIZE(size
), GFP_NOFS
);
1264 b_entry_name
= kmalloc(entry
->e_name_len
+ 1, GFP_NOFS
);
1265 if (!buffer
|| !b_entry_name
) {
1269 /* Save the entry name and the entry value */
1270 memcpy(buffer
, (void *)IFIRST(header
) + offs
,
1271 EXT4_XATTR_SIZE(size
));
1272 memcpy(b_entry_name
, entry
->e_name
, entry
->e_name_len
);
1273 b_entry_name
[entry
->e_name_len
] = '\0';
1274 i
.name
= b_entry_name
;
1276 error
= ext4_get_inode_loc(inode
, &is
->iloc
);
1280 error
= ext4_xattr_ibody_find(inode
, &i
, is
);
1284 /* Remove the chosen entry from the inode */
1285 error
= ext4_xattr_ibody_set(handle
, inode
, &i
, is
);
1287 entry
= IFIRST(header
);
1288 if (entry_size
+ EXT4_XATTR_SIZE(size
) >= new_extra_isize
)
1289 shift_bytes
= new_extra_isize
;
1291 shift_bytes
= entry_size
+ size
;
1292 /* Adjust the offsets and shift the remaining entries ahead */
1293 ext4_xattr_shift_entries(entry
, EXT4_I(inode
)->i_extra_isize
-
1294 shift_bytes
, (void *)raw_inode
+
1295 EXT4_GOOD_OLD_INODE_SIZE
+ extra_isize
+ shift_bytes
,
1296 (void *)header
, total_ino
- entry_size
,
1297 inode
->i_sb
->s_blocksize
);
1299 extra_isize
+= shift_bytes
;
1300 new_extra_isize
-= shift_bytes
;
1301 EXT4_I(inode
)->i_extra_isize
= extra_isize
;
1303 i
.name
= b_entry_name
;
1306 error
= ext4_xattr_block_find(inode
, &i
, bs
);
1310 /* Add entry which was removed from the inode into the block */
1311 error
= ext4_xattr_block_set(handle
, inode
, &i
, bs
);
1314 kfree(b_entry_name
);
1316 brelse(is
->iloc
.bh
);
1321 up_write(&EXT4_I(inode
)->xattr_sem
);
1325 kfree(b_entry_name
);
1328 brelse(is
->iloc
.bh
);
1332 up_write(&EXT4_I(inode
)->xattr_sem
);
1339 * ext4_xattr_delete_inode()
1341 * Free extended attribute resources associated with this inode. This
1342 * is called immediately before an inode is freed. We have exclusive
1343 * access to the inode.
1346 ext4_xattr_delete_inode(handle_t
*handle
, struct inode
*inode
)
1348 struct buffer_head
*bh
= NULL
;
1350 if (!EXT4_I(inode
)->i_file_acl
)
1352 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
1354 ext4_error(inode
->i_sb
, __func__
,
1355 "inode %lu: block %llu read error", inode
->i_ino
,
1356 EXT4_I(inode
)->i_file_acl
);
1359 if (BHDR(bh
)->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
) ||
1360 BHDR(bh
)->h_blocks
!= cpu_to_le32(1)) {
1361 ext4_error(inode
->i_sb
, __func__
,
1362 "inode %lu: bad block %llu", inode
->i_ino
,
1363 EXT4_I(inode
)->i_file_acl
);
1366 ext4_xattr_release_block(handle
, inode
, bh
);
1367 EXT4_I(inode
)->i_file_acl
= 0;
1374 * ext4_xattr_put_super()
1376 * This is called when a file system is unmounted.
1379 ext4_xattr_put_super(struct super_block
*sb
)
1381 mb_cache_shrink(sb
->s_bdev
);
1385 * ext4_xattr_cache_insert()
1387 * Create a new entry in the extended attribute cache, and insert
1388 * it unless such an entry is already in the cache.
1390 * Returns 0, or a negative error number on failure.
1393 ext4_xattr_cache_insert(struct buffer_head
*bh
)
1395 __u32 hash
= le32_to_cpu(BHDR(bh
)->h_hash
);
1396 struct mb_cache_entry
*ce
;
1399 ce
= mb_cache_entry_alloc(ext4_xattr_cache
, GFP_NOFS
);
1401 ea_bdebug(bh
, "out of memory");
1404 error
= mb_cache_entry_insert(ce
, bh
->b_bdev
, bh
->b_blocknr
, &hash
);
1406 mb_cache_entry_free(ce
);
1407 if (error
== -EBUSY
) {
1408 ea_bdebug(bh
, "already in cache");
1412 ea_bdebug(bh
, "inserting [%x]", (int)hash
);
1413 mb_cache_entry_release(ce
);
1420 * Compare two extended attribute blocks for equality.
1422 * Returns 0 if the blocks are equal, 1 if they differ, and
1423 * a negative error number on errors.
1426 ext4_xattr_cmp(struct ext4_xattr_header
*header1
,
1427 struct ext4_xattr_header
*header2
)
1429 struct ext4_xattr_entry
*entry1
, *entry2
;
1431 entry1
= ENTRY(header1
+1);
1432 entry2
= ENTRY(header2
+1);
1433 while (!IS_LAST_ENTRY(entry1
)) {
1434 if (IS_LAST_ENTRY(entry2
))
1436 if (entry1
->e_hash
!= entry2
->e_hash
||
1437 entry1
->e_name_index
!= entry2
->e_name_index
||
1438 entry1
->e_name_len
!= entry2
->e_name_len
||
1439 entry1
->e_value_size
!= entry2
->e_value_size
||
1440 memcmp(entry1
->e_name
, entry2
->e_name
, entry1
->e_name_len
))
1442 if (entry1
->e_value_block
!= 0 || entry2
->e_value_block
!= 0)
1444 if (memcmp((char *)header1
+ le16_to_cpu(entry1
->e_value_offs
),
1445 (char *)header2
+ le16_to_cpu(entry2
->e_value_offs
),
1446 le32_to_cpu(entry1
->e_value_size
)))
1449 entry1
= EXT4_XATTR_NEXT(entry1
);
1450 entry2
= EXT4_XATTR_NEXT(entry2
);
1452 if (!IS_LAST_ENTRY(entry2
))
1458 * ext4_xattr_cache_find()
1460 * Find an identical extended attribute block.
1462 * Returns a pointer to the block found, or NULL if such a block was
1463 * not found or an error occurred.
1465 static struct buffer_head
*
1466 ext4_xattr_cache_find(struct inode
*inode
, struct ext4_xattr_header
*header
,
1467 struct mb_cache_entry
**pce
)
1469 __u32 hash
= le32_to_cpu(header
->h_hash
);
1470 struct mb_cache_entry
*ce
;
1472 if (!header
->h_hash
)
1473 return NULL
; /* never share */
1474 ea_idebug(inode
, "looking for cached blocks [%x]", (int)hash
);
1476 ce
= mb_cache_entry_find_first(ext4_xattr_cache
, 0,
1477 inode
->i_sb
->s_bdev
, hash
);
1479 struct buffer_head
*bh
;
1482 if (PTR_ERR(ce
) == -EAGAIN
)
1486 bh
= sb_bread(inode
->i_sb
, ce
->e_block
);
1488 ext4_error(inode
->i_sb
, __func__
,
1489 "inode %lu: block %lu read error",
1490 inode
->i_ino
, (unsigned long) ce
->e_block
);
1491 } else if (le32_to_cpu(BHDR(bh
)->h_refcount
) >=
1492 EXT4_XATTR_REFCOUNT_MAX
) {
1493 ea_idebug(inode
, "block %lu refcount %d>=%d",
1494 (unsigned long) ce
->e_block
,
1495 le32_to_cpu(BHDR(bh
)->h_refcount
),
1496 EXT4_XATTR_REFCOUNT_MAX
);
1497 } else if (ext4_xattr_cmp(header
, BHDR(bh
)) == 0) {
1502 ce
= mb_cache_entry_find_next(ce
, 0, inode
->i_sb
->s_bdev
, hash
);
1507 #define NAME_HASH_SHIFT 5
1508 #define VALUE_HASH_SHIFT 16
1511 * ext4_xattr_hash_entry()
1513 * Compute the hash of an extended attribute.
1515 static inline void ext4_xattr_hash_entry(struct ext4_xattr_header
*header
,
1516 struct ext4_xattr_entry
*entry
)
1519 char *name
= entry
->e_name
;
1522 for (n
= 0; n
< entry
->e_name_len
; n
++) {
1523 hash
= (hash
<< NAME_HASH_SHIFT
) ^
1524 (hash
>> (8*sizeof(hash
) - NAME_HASH_SHIFT
)) ^
1528 if (entry
->e_value_block
== 0 && entry
->e_value_size
!= 0) {
1529 __le32
*value
= (__le32
*)((char *)header
+
1530 le16_to_cpu(entry
->e_value_offs
));
1531 for (n
= (le32_to_cpu(entry
->e_value_size
) +
1532 EXT4_XATTR_ROUND
) >> EXT4_XATTR_PAD_BITS
; n
; n
--) {
1533 hash
= (hash
<< VALUE_HASH_SHIFT
) ^
1534 (hash
>> (8*sizeof(hash
) - VALUE_HASH_SHIFT
)) ^
1535 le32_to_cpu(*value
++);
1538 entry
->e_hash
= cpu_to_le32(hash
);
1541 #undef NAME_HASH_SHIFT
1542 #undef VALUE_HASH_SHIFT
1544 #define BLOCK_HASH_SHIFT 16
1547 * ext4_xattr_rehash()
1549 * Re-compute the extended attribute hash value after an entry has changed.
1551 static void ext4_xattr_rehash(struct ext4_xattr_header
*header
,
1552 struct ext4_xattr_entry
*entry
)
1554 struct ext4_xattr_entry
*here
;
1557 ext4_xattr_hash_entry(header
, entry
);
1558 here
= ENTRY(header
+1);
1559 while (!IS_LAST_ENTRY(here
)) {
1560 if (!here
->e_hash
) {
1561 /* Block is not shared if an entry's hash value == 0 */
1565 hash
= (hash
<< BLOCK_HASH_SHIFT
) ^
1566 (hash
>> (8*sizeof(hash
) - BLOCK_HASH_SHIFT
)) ^
1567 le32_to_cpu(here
->e_hash
);
1568 here
= EXT4_XATTR_NEXT(here
);
1570 header
->h_hash
= cpu_to_le32(hash
);
1573 #undef BLOCK_HASH_SHIFT
1576 init_ext4_xattr(void)
1578 ext4_xattr_cache
= mb_cache_create("ext4_xattr", NULL
,
1579 sizeof(struct mb_cache_entry
) +
1580 sizeof(((struct mb_cache_entry
*) 0)->e_indexes
[0]), 1, 6);
1581 if (!ext4_xattr_cache
)
1587 exit_ext4_xattr(void)
1589 if (ext4_xattr_cache
)
1590 mb_cache_destroy(ext4_xattr_cache
);
1591 ext4_xattr_cache
= NULL
;