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 #ifdef EXT4_XATTR_DEBUG
65 # define ea_idebug(inode, f...) do { \
66 printk(KERN_DEBUG "inode %s:%lu: ", \
67 inode->i_sb->s_id, inode->i_ino); \
71 # define ea_bdebug(bh, f...) do { \
72 char b[BDEVNAME_SIZE]; \
73 printk(KERN_DEBUG "block %s:%lu: ", \
74 bdevname(bh->b_bdev, b), \
75 (unsigned long) bh->b_blocknr); \
80 # define ea_idebug(inode, fmt, ...) no_printk(fmt, ##__VA_ARGS__)
81 # define ea_bdebug(bh, fmt, ...) no_printk(fmt, ##__VA_ARGS__)
84 static void ext4_xattr_cache_insert(struct buffer_head
*);
85 static struct buffer_head
*ext4_xattr_cache_find(struct inode
*,
86 struct ext4_xattr_header
*,
87 struct mb_cache_entry
**);
88 static void ext4_xattr_rehash(struct ext4_xattr_header
*,
89 struct ext4_xattr_entry
*);
90 static int ext4_xattr_list(struct dentry
*dentry
, char *buffer
,
93 static struct mb_cache
*ext4_xattr_cache
;
95 static const struct xattr_handler
*ext4_xattr_handler_map
[] = {
96 [EXT4_XATTR_INDEX_USER
] = &ext4_xattr_user_handler
,
97 #ifdef CONFIG_EXT4_FS_POSIX_ACL
98 [EXT4_XATTR_INDEX_POSIX_ACL_ACCESS
] = &ext4_xattr_acl_access_handler
,
99 [EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT
] = &ext4_xattr_acl_default_handler
,
101 [EXT4_XATTR_INDEX_TRUSTED
] = &ext4_xattr_trusted_handler
,
102 #ifdef CONFIG_EXT4_FS_SECURITY
103 [EXT4_XATTR_INDEX_SECURITY
] = &ext4_xattr_security_handler
,
107 const struct xattr_handler
*ext4_xattr_handlers
[] = {
108 &ext4_xattr_user_handler
,
109 &ext4_xattr_trusted_handler
,
110 #ifdef CONFIG_EXT4_FS_POSIX_ACL
111 &ext4_xattr_acl_access_handler
,
112 &ext4_xattr_acl_default_handler
,
114 #ifdef CONFIG_EXT4_FS_SECURITY
115 &ext4_xattr_security_handler
,
120 static __le32
ext4_xattr_block_csum(struct inode
*inode
,
122 struct ext4_xattr_header
*hdr
)
124 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
127 old
= hdr
->h_checksum
;
129 block_nr
= cpu_to_le64(block_nr
);
130 csum
= ext4_chksum(sbi
, sbi
->s_csum_seed
, (__u8
*)&block_nr
,
132 csum
= ext4_chksum(sbi
, csum
, (__u8
*)hdr
,
133 EXT4_BLOCK_SIZE(inode
->i_sb
));
135 hdr
->h_checksum
= old
;
136 return cpu_to_le32(csum
);
139 static int ext4_xattr_block_csum_verify(struct inode
*inode
,
141 struct ext4_xattr_header
*hdr
)
143 if (EXT4_HAS_RO_COMPAT_FEATURE(inode
->i_sb
,
144 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM
) &&
145 (hdr
->h_checksum
!= ext4_xattr_block_csum(inode
, block_nr
, hdr
)))
150 static void ext4_xattr_block_csum_set(struct inode
*inode
,
152 struct ext4_xattr_header
*hdr
)
154 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode
->i_sb
,
155 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM
))
158 hdr
->h_checksum
= ext4_xattr_block_csum(inode
, block_nr
, hdr
);
161 static inline int ext4_handle_dirty_xattr_block(handle_t
*handle
,
163 struct buffer_head
*bh
)
165 ext4_xattr_block_csum_set(inode
, bh
->b_blocknr
, BHDR(bh
));
166 return ext4_handle_dirty_metadata(handle
, inode
, bh
);
169 static inline const struct xattr_handler
*
170 ext4_xattr_handler(int name_index
)
172 const struct xattr_handler
*handler
= NULL
;
174 if (name_index
> 0 && name_index
< ARRAY_SIZE(ext4_xattr_handler_map
))
175 handler
= ext4_xattr_handler_map
[name_index
];
180 * Inode operation listxattr()
182 * dentry->d_inode->i_mutex: don't care
185 ext4_listxattr(struct dentry
*dentry
, char *buffer
, size_t size
)
187 return ext4_xattr_list(dentry
, buffer
, size
);
191 ext4_xattr_check_names(struct ext4_xattr_entry
*entry
, void *end
)
193 while (!IS_LAST_ENTRY(entry
)) {
194 struct ext4_xattr_entry
*next
= EXT4_XATTR_NEXT(entry
);
195 if ((void *)next
>= end
)
203 ext4_xattr_check_block(struct inode
*inode
, struct buffer_head
*bh
)
207 if (buffer_verified(bh
))
210 if (BHDR(bh
)->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
) ||
211 BHDR(bh
)->h_blocks
!= cpu_to_le32(1))
213 if (!ext4_xattr_block_csum_verify(inode
, bh
->b_blocknr
, BHDR(bh
)))
215 error
= ext4_xattr_check_names(BFIRST(bh
), bh
->b_data
+ bh
->b_size
);
217 set_buffer_verified(bh
);
222 ext4_xattr_check_entry(struct ext4_xattr_entry
*entry
, size_t size
)
224 size_t value_size
= le32_to_cpu(entry
->e_value_size
);
226 if (entry
->e_value_block
!= 0 || value_size
> size
||
227 le16_to_cpu(entry
->e_value_offs
) + value_size
> size
)
233 ext4_xattr_find_entry(struct ext4_xattr_entry
**pentry
, int name_index
,
234 const char *name
, size_t size
, int sorted
)
236 struct ext4_xattr_entry
*entry
;
242 name_len
= strlen(name
);
244 for (; !IS_LAST_ENTRY(entry
); entry
= EXT4_XATTR_NEXT(entry
)) {
245 cmp
= name_index
- entry
->e_name_index
;
247 cmp
= name_len
- entry
->e_name_len
;
249 cmp
= memcmp(name
, entry
->e_name
, name_len
);
250 if (cmp
<= 0 && (sorted
|| cmp
== 0))
254 if (!cmp
&& ext4_xattr_check_entry(entry
, size
))
256 return cmp
? -ENODATA
: 0;
260 ext4_xattr_block_get(struct inode
*inode
, int name_index
, const char *name
,
261 void *buffer
, size_t buffer_size
)
263 struct buffer_head
*bh
= NULL
;
264 struct ext4_xattr_entry
*entry
;
268 ea_idebug(inode
, "name=%d.%s, buffer=%p, buffer_size=%ld",
269 name_index
, name
, buffer
, (long)buffer_size
);
272 if (!EXT4_I(inode
)->i_file_acl
)
274 ea_idebug(inode
, "reading block %llu",
275 (unsigned long long)EXT4_I(inode
)->i_file_acl
);
276 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
279 ea_bdebug(bh
, "b_count=%d, refcount=%d",
280 atomic_read(&(bh
->b_count
)), le32_to_cpu(BHDR(bh
)->h_refcount
));
281 if (ext4_xattr_check_block(inode
, bh
)) {
283 EXT4_ERROR_INODE(inode
, "bad block %llu",
284 EXT4_I(inode
)->i_file_acl
);
288 ext4_xattr_cache_insert(bh
);
290 error
= ext4_xattr_find_entry(&entry
, name_index
, name
, bh
->b_size
, 1);
295 size
= le32_to_cpu(entry
->e_value_size
);
298 if (size
> buffer_size
)
300 memcpy(buffer
, bh
->b_data
+ le16_to_cpu(entry
->e_value_offs
),
311 ext4_xattr_ibody_get(struct inode
*inode
, int name_index
, const char *name
,
312 void *buffer
, size_t buffer_size
)
314 struct ext4_xattr_ibody_header
*header
;
315 struct ext4_xattr_entry
*entry
;
316 struct ext4_inode
*raw_inode
;
317 struct ext4_iloc iloc
;
322 if (!ext4_test_inode_state(inode
, EXT4_STATE_XATTR
))
324 error
= ext4_get_inode_loc(inode
, &iloc
);
327 raw_inode
= ext4_raw_inode(&iloc
);
328 header
= IHDR(inode
, raw_inode
);
329 entry
= IFIRST(header
);
330 end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
331 error
= ext4_xattr_check_names(entry
, end
);
334 error
= ext4_xattr_find_entry(&entry
, name_index
, name
,
335 end
- (void *)entry
, 0);
338 size
= le32_to_cpu(entry
->e_value_size
);
341 if (size
> buffer_size
)
343 memcpy(buffer
, (void *)IFIRST(header
) +
344 le16_to_cpu(entry
->e_value_offs
), size
);
356 * Copy an extended attribute into the buffer
357 * provided, or compute the buffer size required.
358 * Buffer is NULL to compute the size of the buffer required.
360 * Returns a negative error number on failure, or the number of bytes
361 * used / required on success.
364 ext4_xattr_get(struct inode
*inode
, int name_index
, const char *name
,
365 void *buffer
, size_t buffer_size
)
369 down_read(&EXT4_I(inode
)->xattr_sem
);
370 error
= ext4_xattr_ibody_get(inode
, name_index
, name
, buffer
,
372 if (error
== -ENODATA
)
373 error
= ext4_xattr_block_get(inode
, name_index
, name
, buffer
,
375 up_read(&EXT4_I(inode
)->xattr_sem
);
380 ext4_xattr_list_entries(struct dentry
*dentry
, struct ext4_xattr_entry
*entry
,
381 char *buffer
, size_t buffer_size
)
383 size_t rest
= buffer_size
;
385 for (; !IS_LAST_ENTRY(entry
); entry
= EXT4_XATTR_NEXT(entry
)) {
386 const struct xattr_handler
*handler
=
387 ext4_xattr_handler(entry
->e_name_index
);
390 size_t size
= handler
->list(dentry
, buffer
, rest
,
402 return buffer_size
- rest
;
406 ext4_xattr_block_list(struct dentry
*dentry
, char *buffer
, size_t buffer_size
)
408 struct inode
*inode
= dentry
->d_inode
;
409 struct buffer_head
*bh
= NULL
;
412 ea_idebug(inode
, "buffer=%p, buffer_size=%ld",
413 buffer
, (long)buffer_size
);
416 if (!EXT4_I(inode
)->i_file_acl
)
418 ea_idebug(inode
, "reading block %llu",
419 (unsigned long long)EXT4_I(inode
)->i_file_acl
);
420 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
424 ea_bdebug(bh
, "b_count=%d, refcount=%d",
425 atomic_read(&(bh
->b_count
)), le32_to_cpu(BHDR(bh
)->h_refcount
));
426 if (ext4_xattr_check_block(inode
, bh
)) {
427 EXT4_ERROR_INODE(inode
, "bad block %llu",
428 EXT4_I(inode
)->i_file_acl
);
432 ext4_xattr_cache_insert(bh
);
433 error
= ext4_xattr_list_entries(dentry
, BFIRST(bh
), buffer
, buffer_size
);
442 ext4_xattr_ibody_list(struct dentry
*dentry
, char *buffer
, size_t buffer_size
)
444 struct inode
*inode
= dentry
->d_inode
;
445 struct ext4_xattr_ibody_header
*header
;
446 struct ext4_inode
*raw_inode
;
447 struct ext4_iloc iloc
;
451 if (!ext4_test_inode_state(inode
, EXT4_STATE_XATTR
))
453 error
= ext4_get_inode_loc(inode
, &iloc
);
456 raw_inode
= ext4_raw_inode(&iloc
);
457 header
= IHDR(inode
, raw_inode
);
458 end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
459 error
= ext4_xattr_check_names(IFIRST(header
), end
);
462 error
= ext4_xattr_list_entries(dentry
, IFIRST(header
),
463 buffer
, buffer_size
);
473 * Copy a list of attribute names into the buffer
474 * provided, or compute the buffer size required.
475 * Buffer is NULL to compute the size of the buffer required.
477 * Returns a negative error number on failure, or the number of bytes
478 * used / required on success.
481 ext4_xattr_list(struct dentry
*dentry
, char *buffer
, size_t buffer_size
)
485 down_read(&EXT4_I(dentry
->d_inode
)->xattr_sem
);
486 ret
= ret2
= ext4_xattr_ibody_list(dentry
, buffer
, buffer_size
);
493 ret
= ext4_xattr_block_list(dentry
, buffer
, buffer_size
);
498 up_read(&EXT4_I(dentry
->d_inode
)->xattr_sem
);
503 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is
506 static void ext4_xattr_update_super_block(handle_t
*handle
,
507 struct super_block
*sb
)
509 if (EXT4_HAS_COMPAT_FEATURE(sb
, EXT4_FEATURE_COMPAT_EXT_ATTR
))
512 if (ext4_journal_get_write_access(handle
, EXT4_SB(sb
)->s_sbh
) == 0) {
513 EXT4_SET_COMPAT_FEATURE(sb
, EXT4_FEATURE_COMPAT_EXT_ATTR
);
514 ext4_handle_dirty_super(handle
, sb
);
519 * Release the xattr block BH: If the reference count is > 1, decrement
520 * it; otherwise free the block.
523 ext4_xattr_release_block(handle_t
*handle
, struct inode
*inode
,
524 struct buffer_head
*bh
)
526 struct mb_cache_entry
*ce
= NULL
;
529 ce
= mb_cache_entry_get(ext4_xattr_cache
, bh
->b_bdev
, bh
->b_blocknr
);
530 error
= ext4_journal_get_write_access(handle
, bh
);
535 if (BHDR(bh
)->h_refcount
== cpu_to_le32(1)) {
536 ea_bdebug(bh
, "refcount now=0; freeing");
538 mb_cache_entry_free(ce
);
540 ext4_free_blocks(handle
, inode
, bh
, 0, 1,
541 EXT4_FREE_BLOCKS_METADATA
|
542 EXT4_FREE_BLOCKS_FORGET
);
545 le32_add_cpu(&BHDR(bh
)->h_refcount
, -1);
547 mb_cache_entry_release(ce
);
549 error
= ext4_handle_dirty_xattr_block(handle
, inode
, bh
);
551 ext4_handle_sync(handle
);
552 dquot_free_block(inode
, 1);
553 ea_bdebug(bh
, "refcount now=%d; releasing",
554 le32_to_cpu(BHDR(bh
)->h_refcount
));
557 ext4_std_error(inode
->i_sb
, error
);
562 * Find the available free space for EAs. This also returns the total number of
563 * bytes used by EA entries.
565 static size_t ext4_xattr_free_space(struct ext4_xattr_entry
*last
,
566 size_t *min_offs
, void *base
, int *total
)
568 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
569 *total
+= EXT4_XATTR_LEN(last
->e_name_len
);
570 if (!last
->e_value_block
&& last
->e_value_size
) {
571 size_t offs
= le16_to_cpu(last
->e_value_offs
);
572 if (offs
< *min_offs
)
576 return (*min_offs
- ((void *)last
- base
) - sizeof(__u32
));
580 ext4_xattr_set_entry(struct ext4_xattr_info
*i
, struct ext4_xattr_search
*s
)
582 struct ext4_xattr_entry
*last
;
583 size_t free
, min_offs
= s
->end
- s
->base
, name_len
= strlen(i
->name
);
585 /* Compute min_offs and last. */
587 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
588 if (!last
->e_value_block
&& last
->e_value_size
) {
589 size_t offs
= le16_to_cpu(last
->e_value_offs
);
594 free
= min_offs
- ((void *)last
- s
->base
) - sizeof(__u32
);
596 if (!s
->here
->e_value_block
&& s
->here
->e_value_size
) {
597 size_t size
= le32_to_cpu(s
->here
->e_value_size
);
598 free
+= EXT4_XATTR_SIZE(size
);
600 free
+= EXT4_XATTR_LEN(name_len
);
603 if (free
< EXT4_XATTR_SIZE(i
->value_len
) ||
604 free
< EXT4_XATTR_LEN(name_len
) +
605 EXT4_XATTR_SIZE(i
->value_len
))
609 if (i
->value
&& s
->not_found
) {
610 /* Insert the new name. */
611 size_t size
= EXT4_XATTR_LEN(name_len
);
612 size_t rest
= (void *)last
- (void *)s
->here
+ sizeof(__u32
);
613 memmove((void *)s
->here
+ size
, s
->here
, rest
);
614 memset(s
->here
, 0, size
);
615 s
->here
->e_name_index
= i
->name_index
;
616 s
->here
->e_name_len
= name_len
;
617 memcpy(s
->here
->e_name
, i
->name
, name_len
);
619 if (!s
->here
->e_value_block
&& s
->here
->e_value_size
) {
620 void *first_val
= s
->base
+ min_offs
;
621 size_t offs
= le16_to_cpu(s
->here
->e_value_offs
);
622 void *val
= s
->base
+ offs
;
623 size_t size
= EXT4_XATTR_SIZE(
624 le32_to_cpu(s
->here
->e_value_size
));
626 if (i
->value
&& size
== EXT4_XATTR_SIZE(i
->value_len
)) {
627 /* The old and the new value have the same
628 size. Just replace. */
629 s
->here
->e_value_size
=
630 cpu_to_le32(i
->value_len
);
631 if (i
->value
== EXT4_ZERO_XATTR_VALUE
) {
632 memset(val
, 0, size
);
634 /* Clear pad bytes first. */
635 memset(val
+ size
- EXT4_XATTR_PAD
, 0,
637 memcpy(val
, i
->value
, i
->value_len
);
642 /* Remove the old value. */
643 memmove(first_val
+ size
, first_val
, val
- first_val
);
644 memset(first_val
, 0, size
);
645 s
->here
->e_value_size
= 0;
646 s
->here
->e_value_offs
= 0;
649 /* Adjust all value offsets. */
651 while (!IS_LAST_ENTRY(last
)) {
652 size_t o
= le16_to_cpu(last
->e_value_offs
);
653 if (!last
->e_value_block
&&
654 last
->e_value_size
&& o
< offs
)
656 cpu_to_le16(o
+ size
);
657 last
= EXT4_XATTR_NEXT(last
);
661 /* Remove the old name. */
662 size_t size
= EXT4_XATTR_LEN(name_len
);
663 last
= ENTRY((void *)last
- size
);
664 memmove(s
->here
, (void *)s
->here
+ size
,
665 (void *)last
- (void *)s
->here
+ sizeof(__u32
));
666 memset(last
, 0, size
);
671 /* Insert the new value. */
672 s
->here
->e_value_size
= cpu_to_le32(i
->value_len
);
674 size_t size
= EXT4_XATTR_SIZE(i
->value_len
);
675 void *val
= s
->base
+ min_offs
- size
;
676 s
->here
->e_value_offs
= cpu_to_le16(min_offs
- size
);
677 if (i
->value
== EXT4_ZERO_XATTR_VALUE
) {
678 memset(val
, 0, size
);
680 /* Clear the pad bytes first. */
681 memset(val
+ size
- EXT4_XATTR_PAD
, 0,
683 memcpy(val
, i
->value
, i
->value_len
);
690 struct ext4_xattr_block_find
{
691 struct ext4_xattr_search s
;
692 struct buffer_head
*bh
;
696 ext4_xattr_block_find(struct inode
*inode
, struct ext4_xattr_info
*i
,
697 struct ext4_xattr_block_find
*bs
)
699 struct super_block
*sb
= inode
->i_sb
;
702 ea_idebug(inode
, "name=%d.%s, value=%p, value_len=%ld",
703 i
->name_index
, i
->name
, i
->value
, (long)i
->value_len
);
705 if (EXT4_I(inode
)->i_file_acl
) {
706 /* The inode already has an extended attribute block. */
707 bs
->bh
= sb_bread(sb
, EXT4_I(inode
)->i_file_acl
);
711 ea_bdebug(bs
->bh
, "b_count=%d, refcount=%d",
712 atomic_read(&(bs
->bh
->b_count
)),
713 le32_to_cpu(BHDR(bs
->bh
)->h_refcount
));
714 if (ext4_xattr_check_block(inode
, bs
->bh
)) {
715 EXT4_ERROR_INODE(inode
, "bad block %llu",
716 EXT4_I(inode
)->i_file_acl
);
720 /* Find the named attribute. */
721 bs
->s
.base
= BHDR(bs
->bh
);
722 bs
->s
.first
= BFIRST(bs
->bh
);
723 bs
->s
.end
= bs
->bh
->b_data
+ bs
->bh
->b_size
;
724 bs
->s
.here
= bs
->s
.first
;
725 error
= ext4_xattr_find_entry(&bs
->s
.here
, i
->name_index
,
726 i
->name
, bs
->bh
->b_size
, 1);
727 if (error
&& error
!= -ENODATA
)
729 bs
->s
.not_found
= error
;
738 ext4_xattr_block_set(handle_t
*handle
, struct inode
*inode
,
739 struct ext4_xattr_info
*i
,
740 struct ext4_xattr_block_find
*bs
)
742 struct super_block
*sb
= inode
->i_sb
;
743 struct buffer_head
*new_bh
= NULL
;
744 struct ext4_xattr_search
*s
= &bs
->s
;
745 struct mb_cache_entry
*ce
= NULL
;
748 #define header(x) ((struct ext4_xattr_header *)(x))
750 if (i
->value
&& i
->value_len
> sb
->s_blocksize
)
753 ce
= mb_cache_entry_get(ext4_xattr_cache
, bs
->bh
->b_bdev
,
755 error
= ext4_journal_get_write_access(handle
, bs
->bh
);
760 if (header(s
->base
)->h_refcount
== cpu_to_le32(1)) {
762 mb_cache_entry_free(ce
);
765 ea_bdebug(bs
->bh
, "modifying in-place");
766 error
= ext4_xattr_set_entry(i
, s
);
768 if (!IS_LAST_ENTRY(s
->first
))
769 ext4_xattr_rehash(header(s
->base
),
771 ext4_xattr_cache_insert(bs
->bh
);
773 unlock_buffer(bs
->bh
);
777 error
= ext4_handle_dirty_xattr_block(handle
,
784 int offset
= (char *)s
->here
- bs
->bh
->b_data
;
786 unlock_buffer(bs
->bh
);
788 mb_cache_entry_release(ce
);
791 ea_bdebug(bs
->bh
, "cloning");
792 s
->base
= kmalloc(bs
->bh
->b_size
, GFP_NOFS
);
796 memcpy(s
->base
, BHDR(bs
->bh
), bs
->bh
->b_size
);
797 s
->first
= ENTRY(header(s
->base
)+1);
798 header(s
->base
)->h_refcount
= cpu_to_le32(1);
799 s
->here
= ENTRY(s
->base
+ offset
);
800 s
->end
= s
->base
+ bs
->bh
->b_size
;
803 /* Allocate a buffer where we construct the new block. */
804 s
->base
= kzalloc(sb
->s_blocksize
, GFP_NOFS
);
805 /* assert(header == s->base) */
809 header(s
->base
)->h_magic
= cpu_to_le32(EXT4_XATTR_MAGIC
);
810 header(s
->base
)->h_blocks
= cpu_to_le32(1);
811 header(s
->base
)->h_refcount
= cpu_to_le32(1);
812 s
->first
= ENTRY(header(s
->base
)+1);
813 s
->here
= ENTRY(header(s
->base
)+1);
814 s
->end
= s
->base
+ sb
->s_blocksize
;
817 error
= ext4_xattr_set_entry(i
, s
);
822 if (!IS_LAST_ENTRY(s
->first
))
823 ext4_xattr_rehash(header(s
->base
), s
->here
);
826 if (!IS_LAST_ENTRY(s
->first
)) {
827 new_bh
= ext4_xattr_cache_find(inode
, header(s
->base
), &ce
);
829 /* We found an identical block in the cache. */
830 if (new_bh
== bs
->bh
)
831 ea_bdebug(new_bh
, "keeping");
833 /* The old block is released after updating
835 error
= dquot_alloc_block(inode
, 1);
838 error
= ext4_journal_get_write_access(handle
,
843 le32_add_cpu(&BHDR(new_bh
)->h_refcount
, 1);
844 ea_bdebug(new_bh
, "reusing; refcount now=%d",
845 le32_to_cpu(BHDR(new_bh
)->h_refcount
));
846 unlock_buffer(new_bh
);
847 error
= ext4_handle_dirty_xattr_block(handle
,
853 mb_cache_entry_release(ce
);
855 } else if (bs
->bh
&& s
->base
== bs
->bh
->b_data
) {
856 /* We were modifying this block in-place. */
857 ea_bdebug(bs
->bh
, "keeping this block");
861 /* We need to allocate a new block */
862 ext4_fsblk_t goal
, block
;
864 goal
= ext4_group_first_block_no(sb
,
865 EXT4_I(inode
)->i_block_group
);
867 /* non-extent files can't have physical blocks past 2^32 */
868 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)))
869 goal
= goal
& EXT4_MAX_BLOCK_FILE_PHYS
;
872 * take i_data_sem because we will test
873 * i_delalloc_reserved_flag in ext4_mb_new_blocks
875 down_read((&EXT4_I(inode
)->i_data_sem
));
876 block
= ext4_new_meta_blocks(handle
, inode
, goal
, 0,
878 up_read((&EXT4_I(inode
)->i_data_sem
));
882 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)))
883 BUG_ON(block
> EXT4_MAX_BLOCK_FILE_PHYS
);
885 ea_idebug(inode
, "creating block %llu",
886 (unsigned long long)block
);
888 new_bh
= sb_getblk(sb
, block
);
891 ext4_free_blocks(handle
, inode
, NULL
, block
, 1,
892 EXT4_FREE_BLOCKS_METADATA
);
897 error
= ext4_journal_get_create_access(handle
, new_bh
);
899 unlock_buffer(new_bh
);
902 memcpy(new_bh
->b_data
, s
->base
, new_bh
->b_size
);
903 set_buffer_uptodate(new_bh
);
904 unlock_buffer(new_bh
);
905 ext4_xattr_cache_insert(new_bh
);
906 error
= ext4_handle_dirty_xattr_block(handle
,
913 /* Update the inode. */
914 EXT4_I(inode
)->i_file_acl
= new_bh
? new_bh
->b_blocknr
: 0;
916 /* Drop the previous xattr block. */
917 if (bs
->bh
&& bs
->bh
!= new_bh
)
918 ext4_xattr_release_block(handle
, inode
, bs
->bh
);
923 mb_cache_entry_release(ce
);
925 if (!(bs
->bh
&& s
->base
== bs
->bh
->b_data
))
931 dquot_free_block(inode
, 1);
935 EXT4_ERROR_INODE(inode
, "bad block %llu",
936 EXT4_I(inode
)->i_file_acl
);
942 int ext4_xattr_ibody_find(struct inode
*inode
, struct ext4_xattr_info
*i
,
943 struct ext4_xattr_ibody_find
*is
)
945 struct ext4_xattr_ibody_header
*header
;
946 struct ext4_inode
*raw_inode
;
949 if (EXT4_I(inode
)->i_extra_isize
== 0)
951 raw_inode
= ext4_raw_inode(&is
->iloc
);
952 header
= IHDR(inode
, raw_inode
);
953 is
->s
.base
= is
->s
.first
= IFIRST(header
);
954 is
->s
.here
= is
->s
.first
;
955 is
->s
.end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
956 if (ext4_test_inode_state(inode
, EXT4_STATE_XATTR
)) {
957 error
= ext4_xattr_check_names(IFIRST(header
), is
->s
.end
);
960 /* Find the named attribute. */
961 error
= ext4_xattr_find_entry(&is
->s
.here
, i
->name_index
,
963 (void *)is
->s
.base
, 0);
964 if (error
&& error
!= -ENODATA
)
966 is
->s
.not_found
= error
;
971 int ext4_xattr_ibody_inline_set(handle_t
*handle
, struct inode
*inode
,
972 struct ext4_xattr_info
*i
,
973 struct ext4_xattr_ibody_find
*is
)
975 struct ext4_xattr_ibody_header
*header
;
976 struct ext4_xattr_search
*s
= &is
->s
;
979 if (EXT4_I(inode
)->i_extra_isize
== 0)
981 error
= ext4_xattr_set_entry(i
, s
);
983 if (error
== -ENOSPC
&&
984 ext4_has_inline_data(inode
)) {
985 error
= ext4_try_to_evict_inline_data(handle
, inode
,
986 EXT4_XATTR_LEN(strlen(i
->name
) +
987 EXT4_XATTR_SIZE(i
->value_len
)));
990 error
= ext4_xattr_ibody_find(inode
, i
, is
);
993 error
= ext4_xattr_set_entry(i
, s
);
998 header
= IHDR(inode
, ext4_raw_inode(&is
->iloc
));
999 if (!IS_LAST_ENTRY(s
->first
)) {
1000 header
->h_magic
= cpu_to_le32(EXT4_XATTR_MAGIC
);
1001 ext4_set_inode_state(inode
, EXT4_STATE_XATTR
);
1003 header
->h_magic
= cpu_to_le32(0);
1004 ext4_clear_inode_state(inode
, EXT4_STATE_XATTR
);
1009 static int ext4_xattr_ibody_set(handle_t
*handle
, struct inode
*inode
,
1010 struct ext4_xattr_info
*i
,
1011 struct ext4_xattr_ibody_find
*is
)
1013 struct ext4_xattr_ibody_header
*header
;
1014 struct ext4_xattr_search
*s
= &is
->s
;
1017 if (EXT4_I(inode
)->i_extra_isize
== 0)
1019 error
= ext4_xattr_set_entry(i
, s
);
1022 header
= IHDR(inode
, ext4_raw_inode(&is
->iloc
));
1023 if (!IS_LAST_ENTRY(s
->first
)) {
1024 header
->h_magic
= cpu_to_le32(EXT4_XATTR_MAGIC
);
1025 ext4_set_inode_state(inode
, EXT4_STATE_XATTR
);
1027 header
->h_magic
= cpu_to_le32(0);
1028 ext4_clear_inode_state(inode
, EXT4_STATE_XATTR
);
1034 * ext4_xattr_set_handle()
1036 * Create, replace or remove an extended attribute for this inode. Value
1037 * is NULL to remove an existing extended attribute, and non-NULL to
1038 * either replace an existing extended attribute, or create a new extended
1039 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
1040 * specify that an extended attribute must exist and must not exist
1041 * previous to the call, respectively.
1043 * Returns 0, or a negative error number on failure.
1046 ext4_xattr_set_handle(handle_t
*handle
, struct inode
*inode
, int name_index
,
1047 const char *name
, const void *value
, size_t value_len
,
1050 struct ext4_xattr_info i
= {
1051 .name_index
= name_index
,
1054 .value_len
= value_len
,
1057 struct ext4_xattr_ibody_find is
= {
1058 .s
= { .not_found
= -ENODATA
, },
1060 struct ext4_xattr_block_find bs
= {
1061 .s
= { .not_found
= -ENODATA
, },
1063 unsigned long no_expand
;
1068 if (strlen(name
) > 255)
1070 down_write(&EXT4_I(inode
)->xattr_sem
);
1071 no_expand
= ext4_test_inode_state(inode
, EXT4_STATE_NO_EXPAND
);
1072 ext4_set_inode_state(inode
, EXT4_STATE_NO_EXPAND
);
1074 error
= ext4_reserve_inode_write(handle
, inode
, &is
.iloc
);
1078 if (ext4_test_inode_state(inode
, EXT4_STATE_NEW
)) {
1079 struct ext4_inode
*raw_inode
= ext4_raw_inode(&is
.iloc
);
1080 memset(raw_inode
, 0, EXT4_SB(inode
->i_sb
)->s_inode_size
);
1081 ext4_clear_inode_state(inode
, EXT4_STATE_NEW
);
1084 error
= ext4_xattr_ibody_find(inode
, &i
, &is
);
1088 error
= ext4_xattr_block_find(inode
, &i
, &bs
);
1091 if (is
.s
.not_found
&& bs
.s
.not_found
) {
1093 if (flags
& XATTR_REPLACE
)
1100 if (flags
& XATTR_CREATE
)
1104 if (!is
.s
.not_found
)
1105 error
= ext4_xattr_ibody_set(handle
, inode
, &i
, &is
);
1106 else if (!bs
.s
.not_found
)
1107 error
= ext4_xattr_block_set(handle
, inode
, &i
, &bs
);
1109 error
= ext4_xattr_ibody_set(handle
, inode
, &i
, &is
);
1110 if (!error
&& !bs
.s
.not_found
) {
1112 error
= ext4_xattr_block_set(handle
, inode
, &i
, &bs
);
1113 } else if (error
== -ENOSPC
) {
1114 if (EXT4_I(inode
)->i_file_acl
&& !bs
.s
.base
) {
1115 error
= ext4_xattr_block_find(inode
, &i
, &bs
);
1119 error
= ext4_xattr_block_set(handle
, inode
, &i
, &bs
);
1122 if (!is
.s
.not_found
) {
1124 error
= ext4_xattr_ibody_set(handle
, inode
, &i
,
1130 ext4_xattr_update_super_block(handle
, inode
->i_sb
);
1131 inode
->i_ctime
= ext4_current_time(inode
);
1133 ext4_clear_inode_state(inode
, EXT4_STATE_NO_EXPAND
);
1134 error
= ext4_mark_iloc_dirty(handle
, inode
, &is
.iloc
);
1136 * The bh is consumed by ext4_mark_iloc_dirty, even with
1141 ext4_handle_sync(handle
);
1148 ext4_clear_inode_state(inode
, EXT4_STATE_NO_EXPAND
);
1149 up_write(&EXT4_I(inode
)->xattr_sem
);
1156 * Like ext4_xattr_set_handle, but start from an inode. This extended
1157 * attribute modification is a filesystem transaction by itself.
1159 * Returns 0, or a negative error number on failure.
1162 ext4_xattr_set(struct inode
*inode
, int name_index
, const char *name
,
1163 const void *value
, size_t value_len
, int flags
)
1166 int error
, retries
= 0;
1167 int credits
= EXT4_DATA_TRANS_BLOCKS(inode
->i_sb
);
1171 * In case of inline data, we may push out the data to a block,
1172 * So reserve the journal space first.
1174 if (ext4_has_inline_data(inode
))
1175 credits
+= ext4_writepage_trans_blocks(inode
) + 1;
1177 handle
= ext4_journal_start(inode
, credits
);
1178 if (IS_ERR(handle
)) {
1179 error
= PTR_ERR(handle
);
1183 error
= ext4_xattr_set_handle(handle
, inode
, name_index
, name
,
1184 value
, value_len
, flags
);
1185 error2
= ext4_journal_stop(handle
);
1186 if (error
== -ENOSPC
&&
1187 ext4_should_retry_alloc(inode
->i_sb
, &retries
))
1197 * Shift the EA entries in the inode to create space for the increased
1200 static void ext4_xattr_shift_entries(struct ext4_xattr_entry
*entry
,
1201 int value_offs_shift
, void *to
,
1202 void *from
, size_t n
, int blocksize
)
1204 struct ext4_xattr_entry
*last
= entry
;
1207 /* Adjust the value offsets of the entries */
1208 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
1209 if (!last
->e_value_block
&& last
->e_value_size
) {
1210 new_offs
= le16_to_cpu(last
->e_value_offs
) +
1212 BUG_ON(new_offs
+ le32_to_cpu(last
->e_value_size
)
1214 last
->e_value_offs
= cpu_to_le16(new_offs
);
1217 /* Shift the entries by n bytes */
1218 memmove(to
, from
, n
);
1222 * Expand an inode by new_extra_isize bytes when EAs are present.
1223 * Returns 0 on success or negative error number on failure.
1225 int ext4_expand_extra_isize_ea(struct inode
*inode
, int new_extra_isize
,
1226 struct ext4_inode
*raw_inode
, handle_t
*handle
)
1228 struct ext4_xattr_ibody_header
*header
;
1229 struct ext4_xattr_entry
*entry
, *last
, *first
;
1230 struct buffer_head
*bh
= NULL
;
1231 struct ext4_xattr_ibody_find
*is
= NULL
;
1232 struct ext4_xattr_block_find
*bs
= NULL
;
1233 char *buffer
= NULL
, *b_entry_name
= NULL
;
1234 size_t min_offs
, free
;
1235 int total_ino
, total_blk
;
1236 void *base
, *start
, *end
;
1237 int extra_isize
= 0, error
= 0, tried_min_extra_isize
= 0;
1238 int s_min_extra_isize
= le16_to_cpu(EXT4_SB(inode
->i_sb
)->s_es
->s_min_extra_isize
);
1240 down_write(&EXT4_I(inode
)->xattr_sem
);
1242 if (EXT4_I(inode
)->i_extra_isize
>= new_extra_isize
) {
1243 up_write(&EXT4_I(inode
)->xattr_sem
);
1247 header
= IHDR(inode
, raw_inode
);
1248 entry
= IFIRST(header
);
1251 * Check if enough free space is available in the inode to shift the
1252 * entries ahead by new_extra_isize.
1255 base
= start
= entry
;
1256 end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
1257 min_offs
= end
- base
;
1259 total_ino
= sizeof(struct ext4_xattr_ibody_header
);
1261 free
= ext4_xattr_free_space(last
, &min_offs
, base
, &total_ino
);
1262 if (free
>= new_extra_isize
) {
1263 entry
= IFIRST(header
);
1264 ext4_xattr_shift_entries(entry
, EXT4_I(inode
)->i_extra_isize
1265 - new_extra_isize
, (void *)raw_inode
+
1266 EXT4_GOOD_OLD_INODE_SIZE
+ new_extra_isize
,
1267 (void *)header
, total_ino
,
1268 inode
->i_sb
->s_blocksize
);
1269 EXT4_I(inode
)->i_extra_isize
= new_extra_isize
;
1275 * Enough free space isn't available in the inode, check if
1276 * EA block can hold new_extra_isize bytes.
1278 if (EXT4_I(inode
)->i_file_acl
) {
1279 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
1283 if (ext4_xattr_check_block(inode
, bh
)) {
1284 EXT4_ERROR_INODE(inode
, "bad block %llu",
1285 EXT4_I(inode
)->i_file_acl
);
1291 end
= bh
->b_data
+ bh
->b_size
;
1292 min_offs
= end
- base
;
1293 free
= ext4_xattr_free_space(first
, &min_offs
, base
,
1295 if (free
< new_extra_isize
) {
1296 if (!tried_min_extra_isize
&& s_min_extra_isize
) {
1297 tried_min_extra_isize
++;
1298 new_extra_isize
= s_min_extra_isize
;
1306 free
= inode
->i_sb
->s_blocksize
;
1309 while (new_extra_isize
> 0) {
1310 size_t offs
, size
, entry_size
;
1311 struct ext4_xattr_entry
*small_entry
= NULL
;
1312 struct ext4_xattr_info i
= {
1316 unsigned int total_size
; /* EA entry size + value size */
1317 unsigned int shift_bytes
; /* No. of bytes to shift EAs by? */
1318 unsigned int min_total_size
= ~0U;
1320 is
= kzalloc(sizeof(struct ext4_xattr_ibody_find
), GFP_NOFS
);
1321 bs
= kzalloc(sizeof(struct ext4_xattr_block_find
), GFP_NOFS
);
1327 is
->s
.not_found
= -ENODATA
;
1328 bs
->s
.not_found
= -ENODATA
;
1332 last
= IFIRST(header
);
1333 /* Find the entry best suited to be pushed into EA block */
1335 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
1337 EXT4_XATTR_SIZE(le32_to_cpu(last
->e_value_size
)) +
1338 EXT4_XATTR_LEN(last
->e_name_len
);
1339 if (total_size
<= free
&& total_size
< min_total_size
) {
1340 if (total_size
< new_extra_isize
) {
1344 min_total_size
= total_size
;
1349 if (entry
== NULL
) {
1351 entry
= small_entry
;
1353 if (!tried_min_extra_isize
&&
1354 s_min_extra_isize
) {
1355 tried_min_extra_isize
++;
1356 new_extra_isize
= s_min_extra_isize
;
1363 offs
= le16_to_cpu(entry
->e_value_offs
);
1364 size
= le32_to_cpu(entry
->e_value_size
);
1365 entry_size
= EXT4_XATTR_LEN(entry
->e_name_len
);
1366 i
.name_index
= entry
->e_name_index
,
1367 buffer
= kmalloc(EXT4_XATTR_SIZE(size
), GFP_NOFS
);
1368 b_entry_name
= kmalloc(entry
->e_name_len
+ 1, GFP_NOFS
);
1369 if (!buffer
|| !b_entry_name
) {
1373 /* Save the entry name and the entry value */
1374 memcpy(buffer
, (void *)IFIRST(header
) + offs
,
1375 EXT4_XATTR_SIZE(size
));
1376 memcpy(b_entry_name
, entry
->e_name
, entry
->e_name_len
);
1377 b_entry_name
[entry
->e_name_len
] = '\0';
1378 i
.name
= b_entry_name
;
1380 error
= ext4_get_inode_loc(inode
, &is
->iloc
);
1384 error
= ext4_xattr_ibody_find(inode
, &i
, is
);
1388 /* Remove the chosen entry from the inode */
1389 error
= ext4_xattr_ibody_set(handle
, inode
, &i
, is
);
1393 entry
= IFIRST(header
);
1394 if (entry_size
+ EXT4_XATTR_SIZE(size
) >= new_extra_isize
)
1395 shift_bytes
= new_extra_isize
;
1397 shift_bytes
= entry_size
+ size
;
1398 /* Adjust the offsets and shift the remaining entries ahead */
1399 ext4_xattr_shift_entries(entry
, EXT4_I(inode
)->i_extra_isize
-
1400 shift_bytes
, (void *)raw_inode
+
1401 EXT4_GOOD_OLD_INODE_SIZE
+ extra_isize
+ shift_bytes
,
1402 (void *)header
, total_ino
- entry_size
,
1403 inode
->i_sb
->s_blocksize
);
1405 extra_isize
+= shift_bytes
;
1406 new_extra_isize
-= shift_bytes
;
1407 EXT4_I(inode
)->i_extra_isize
= extra_isize
;
1409 i
.name
= b_entry_name
;
1412 error
= ext4_xattr_block_find(inode
, &i
, bs
);
1416 /* Add entry which was removed from the inode into the block */
1417 error
= ext4_xattr_block_set(handle
, inode
, &i
, bs
);
1420 kfree(b_entry_name
);
1422 b_entry_name
= NULL
;
1424 brelse(is
->iloc
.bh
);
1429 up_write(&EXT4_I(inode
)->xattr_sem
);
1433 kfree(b_entry_name
);
1436 brelse(is
->iloc
.bh
);
1440 up_write(&EXT4_I(inode
)->xattr_sem
);
1447 * ext4_xattr_delete_inode()
1449 * Free extended attribute resources associated with this inode. This
1450 * is called immediately before an inode is freed. We have exclusive
1451 * access to the inode.
1454 ext4_xattr_delete_inode(handle_t
*handle
, struct inode
*inode
)
1456 struct buffer_head
*bh
= NULL
;
1458 if (!EXT4_I(inode
)->i_file_acl
)
1460 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
1462 EXT4_ERROR_INODE(inode
, "block %llu read error",
1463 EXT4_I(inode
)->i_file_acl
);
1466 if (BHDR(bh
)->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
) ||
1467 BHDR(bh
)->h_blocks
!= cpu_to_le32(1)) {
1468 EXT4_ERROR_INODE(inode
, "bad block %llu",
1469 EXT4_I(inode
)->i_file_acl
);
1472 ext4_xattr_release_block(handle
, inode
, bh
);
1473 EXT4_I(inode
)->i_file_acl
= 0;
1480 * ext4_xattr_put_super()
1482 * This is called when a file system is unmounted.
1485 ext4_xattr_put_super(struct super_block
*sb
)
1487 mb_cache_shrink(sb
->s_bdev
);
1491 * ext4_xattr_cache_insert()
1493 * Create a new entry in the extended attribute cache, and insert
1494 * it unless such an entry is already in the cache.
1496 * Returns 0, or a negative error number on failure.
1499 ext4_xattr_cache_insert(struct buffer_head
*bh
)
1501 __u32 hash
= le32_to_cpu(BHDR(bh
)->h_hash
);
1502 struct mb_cache_entry
*ce
;
1505 ce
= mb_cache_entry_alloc(ext4_xattr_cache
, GFP_NOFS
);
1507 ea_bdebug(bh
, "out of memory");
1510 error
= mb_cache_entry_insert(ce
, bh
->b_bdev
, bh
->b_blocknr
, hash
);
1512 mb_cache_entry_free(ce
);
1513 if (error
== -EBUSY
) {
1514 ea_bdebug(bh
, "already in cache");
1518 ea_bdebug(bh
, "inserting [%x]", (int)hash
);
1519 mb_cache_entry_release(ce
);
1526 * Compare two extended attribute blocks for equality.
1528 * Returns 0 if the blocks are equal, 1 if they differ, and
1529 * a negative error number on errors.
1532 ext4_xattr_cmp(struct ext4_xattr_header
*header1
,
1533 struct ext4_xattr_header
*header2
)
1535 struct ext4_xattr_entry
*entry1
, *entry2
;
1537 entry1
= ENTRY(header1
+1);
1538 entry2
= ENTRY(header2
+1);
1539 while (!IS_LAST_ENTRY(entry1
)) {
1540 if (IS_LAST_ENTRY(entry2
))
1542 if (entry1
->e_hash
!= entry2
->e_hash
||
1543 entry1
->e_name_index
!= entry2
->e_name_index
||
1544 entry1
->e_name_len
!= entry2
->e_name_len
||
1545 entry1
->e_value_size
!= entry2
->e_value_size
||
1546 memcmp(entry1
->e_name
, entry2
->e_name
, entry1
->e_name_len
))
1548 if (entry1
->e_value_block
!= 0 || entry2
->e_value_block
!= 0)
1550 if (memcmp((char *)header1
+ le16_to_cpu(entry1
->e_value_offs
),
1551 (char *)header2
+ le16_to_cpu(entry2
->e_value_offs
),
1552 le32_to_cpu(entry1
->e_value_size
)))
1555 entry1
= EXT4_XATTR_NEXT(entry1
);
1556 entry2
= EXT4_XATTR_NEXT(entry2
);
1558 if (!IS_LAST_ENTRY(entry2
))
1564 * ext4_xattr_cache_find()
1566 * Find an identical extended attribute block.
1568 * Returns a pointer to the block found, or NULL if such a block was
1569 * not found or an error occurred.
1571 static struct buffer_head
*
1572 ext4_xattr_cache_find(struct inode
*inode
, struct ext4_xattr_header
*header
,
1573 struct mb_cache_entry
**pce
)
1575 __u32 hash
= le32_to_cpu(header
->h_hash
);
1576 struct mb_cache_entry
*ce
;
1578 if (!header
->h_hash
)
1579 return NULL
; /* never share */
1580 ea_idebug(inode
, "looking for cached blocks [%x]", (int)hash
);
1582 ce
= mb_cache_entry_find_first(ext4_xattr_cache
, inode
->i_sb
->s_bdev
,
1585 struct buffer_head
*bh
;
1588 if (PTR_ERR(ce
) == -EAGAIN
)
1592 bh
= sb_bread(inode
->i_sb
, ce
->e_block
);
1594 EXT4_ERROR_INODE(inode
, "block %lu read error",
1595 (unsigned long) ce
->e_block
);
1596 } else if (le32_to_cpu(BHDR(bh
)->h_refcount
) >=
1597 EXT4_XATTR_REFCOUNT_MAX
) {
1598 ea_idebug(inode
, "block %lu refcount %d>=%d",
1599 (unsigned long) ce
->e_block
,
1600 le32_to_cpu(BHDR(bh
)->h_refcount
),
1601 EXT4_XATTR_REFCOUNT_MAX
);
1602 } else if (ext4_xattr_cmp(header
, BHDR(bh
)) == 0) {
1607 ce
= mb_cache_entry_find_next(ce
, inode
->i_sb
->s_bdev
, hash
);
1612 #define NAME_HASH_SHIFT 5
1613 #define VALUE_HASH_SHIFT 16
1616 * ext4_xattr_hash_entry()
1618 * Compute the hash of an extended attribute.
1620 static inline void ext4_xattr_hash_entry(struct ext4_xattr_header
*header
,
1621 struct ext4_xattr_entry
*entry
)
1624 char *name
= entry
->e_name
;
1627 for (n
= 0; n
< entry
->e_name_len
; n
++) {
1628 hash
= (hash
<< NAME_HASH_SHIFT
) ^
1629 (hash
>> (8*sizeof(hash
) - NAME_HASH_SHIFT
)) ^
1633 if (entry
->e_value_block
== 0 && entry
->e_value_size
!= 0) {
1634 __le32
*value
= (__le32
*)((char *)header
+
1635 le16_to_cpu(entry
->e_value_offs
));
1636 for (n
= (le32_to_cpu(entry
->e_value_size
) +
1637 EXT4_XATTR_ROUND
) >> EXT4_XATTR_PAD_BITS
; n
; n
--) {
1638 hash
= (hash
<< VALUE_HASH_SHIFT
) ^
1639 (hash
>> (8*sizeof(hash
) - VALUE_HASH_SHIFT
)) ^
1640 le32_to_cpu(*value
++);
1643 entry
->e_hash
= cpu_to_le32(hash
);
1646 #undef NAME_HASH_SHIFT
1647 #undef VALUE_HASH_SHIFT
1649 #define BLOCK_HASH_SHIFT 16
1652 * ext4_xattr_rehash()
1654 * Re-compute the extended attribute hash value after an entry has changed.
1656 static void ext4_xattr_rehash(struct ext4_xattr_header
*header
,
1657 struct ext4_xattr_entry
*entry
)
1659 struct ext4_xattr_entry
*here
;
1662 ext4_xattr_hash_entry(header
, entry
);
1663 here
= ENTRY(header
+1);
1664 while (!IS_LAST_ENTRY(here
)) {
1665 if (!here
->e_hash
) {
1666 /* Block is not shared if an entry's hash value == 0 */
1670 hash
= (hash
<< BLOCK_HASH_SHIFT
) ^
1671 (hash
>> (8*sizeof(hash
) - BLOCK_HASH_SHIFT
)) ^
1672 le32_to_cpu(here
->e_hash
);
1673 here
= EXT4_XATTR_NEXT(here
);
1675 header
->h_hash
= cpu_to_le32(hash
);
1678 #undef BLOCK_HASH_SHIFT
1681 ext4_init_xattr(void)
1683 ext4_xattr_cache
= mb_cache_create("ext4_xattr", 6);
1684 if (!ext4_xattr_cache
)
1690 ext4_exit_xattr(void)
1692 if (ext4_xattr_cache
)
1693 mb_cache_destroy(ext4_xattr_cache
);
1694 ext4_xattr_cache
= NULL
;