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 mb_cache
*, 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 const struct xattr_handler
*ext4_xattr_handler_map
[] = {
94 [EXT4_XATTR_INDEX_USER
] = &ext4_xattr_user_handler
,
95 #ifdef CONFIG_EXT4_FS_POSIX_ACL
96 [EXT4_XATTR_INDEX_POSIX_ACL_ACCESS
] = &posix_acl_access_xattr_handler
,
97 [EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT
] = &posix_acl_default_xattr_handler
,
99 [EXT4_XATTR_INDEX_TRUSTED
] = &ext4_xattr_trusted_handler
,
100 #ifdef CONFIG_EXT4_FS_SECURITY
101 [EXT4_XATTR_INDEX_SECURITY
] = &ext4_xattr_security_handler
,
105 const struct xattr_handler
*ext4_xattr_handlers
[] = {
106 &ext4_xattr_user_handler
,
107 &ext4_xattr_trusted_handler
,
108 #ifdef CONFIG_EXT4_FS_POSIX_ACL
109 &posix_acl_access_xattr_handler
,
110 &posix_acl_default_xattr_handler
,
112 #ifdef CONFIG_EXT4_FS_SECURITY
113 &ext4_xattr_security_handler
,
118 #define EXT4_GET_MB_CACHE(inode) (((struct ext4_sb_info *) \
119 inode->i_sb->s_fs_info)->s_mb_cache)
121 static __le32
ext4_xattr_block_csum(struct inode
*inode
,
123 struct ext4_xattr_header
*hdr
)
125 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
128 __le64 dsk_block_nr
= cpu_to_le64(block_nr
);
130 save_csum
= hdr
->h_checksum
;
132 csum
= ext4_chksum(sbi
, sbi
->s_csum_seed
, (__u8
*)&dsk_block_nr
,
133 sizeof(dsk_block_nr
));
134 csum
= ext4_chksum(sbi
, csum
, (__u8
*)hdr
,
135 EXT4_BLOCK_SIZE(inode
->i_sb
));
137 hdr
->h_checksum
= save_csum
;
138 return cpu_to_le32(csum
);
141 static int ext4_xattr_block_csum_verify(struct inode
*inode
,
143 struct ext4_xattr_header
*hdr
)
145 if (EXT4_HAS_RO_COMPAT_FEATURE(inode
->i_sb
,
146 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM
) &&
147 (hdr
->h_checksum
!= ext4_xattr_block_csum(inode
, block_nr
, hdr
)))
152 static void ext4_xattr_block_csum_set(struct inode
*inode
,
154 struct ext4_xattr_header
*hdr
)
156 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode
->i_sb
,
157 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM
))
160 hdr
->h_checksum
= ext4_xattr_block_csum(inode
, block_nr
, hdr
);
163 static inline int ext4_handle_dirty_xattr_block(handle_t
*handle
,
165 struct buffer_head
*bh
)
167 ext4_xattr_block_csum_set(inode
, bh
->b_blocknr
, BHDR(bh
));
168 return ext4_handle_dirty_metadata(handle
, inode
, bh
);
171 static inline const struct xattr_handler
*
172 ext4_xattr_handler(int name_index
)
174 const struct xattr_handler
*handler
= NULL
;
176 if (name_index
> 0 && name_index
< ARRAY_SIZE(ext4_xattr_handler_map
))
177 handler
= ext4_xattr_handler_map
[name_index
];
182 * Inode operation listxattr()
184 * dentry->d_inode->i_mutex: don't care
187 ext4_listxattr(struct dentry
*dentry
, char *buffer
, size_t size
)
189 return ext4_xattr_list(dentry
, buffer
, size
);
193 ext4_xattr_check_names(struct ext4_xattr_entry
*entry
, void *end
)
195 while (!IS_LAST_ENTRY(entry
)) {
196 struct ext4_xattr_entry
*next
= EXT4_XATTR_NEXT(entry
);
197 if ((void *)next
>= end
)
205 ext4_xattr_check_block(struct inode
*inode
, struct buffer_head
*bh
)
209 if (buffer_verified(bh
))
212 if (BHDR(bh
)->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
) ||
213 BHDR(bh
)->h_blocks
!= cpu_to_le32(1))
215 if (!ext4_xattr_block_csum_verify(inode
, bh
->b_blocknr
, BHDR(bh
)))
217 error
= ext4_xattr_check_names(BFIRST(bh
), bh
->b_data
+ bh
->b_size
);
219 set_buffer_verified(bh
);
224 ext4_xattr_check_entry(struct ext4_xattr_entry
*entry
, size_t size
)
226 size_t value_size
= le32_to_cpu(entry
->e_value_size
);
228 if (entry
->e_value_block
!= 0 || value_size
> size
||
229 le16_to_cpu(entry
->e_value_offs
) + value_size
> size
)
235 ext4_xattr_find_entry(struct ext4_xattr_entry
**pentry
, int name_index
,
236 const char *name
, size_t size
, int sorted
)
238 struct ext4_xattr_entry
*entry
;
244 name_len
= strlen(name
);
246 for (; !IS_LAST_ENTRY(entry
); entry
= EXT4_XATTR_NEXT(entry
)) {
247 cmp
= name_index
- entry
->e_name_index
;
249 cmp
= name_len
- entry
->e_name_len
;
251 cmp
= memcmp(name
, entry
->e_name
, name_len
);
252 if (cmp
<= 0 && (sorted
|| cmp
== 0))
256 if (!cmp
&& ext4_xattr_check_entry(entry
, size
))
258 return cmp
? -ENODATA
: 0;
262 ext4_xattr_block_get(struct inode
*inode
, int name_index
, const char *name
,
263 void *buffer
, size_t buffer_size
)
265 struct buffer_head
*bh
= NULL
;
266 struct ext4_xattr_entry
*entry
;
269 struct mb_cache
*ext4_mb_cache
= EXT4_GET_MB_CACHE(inode
);
271 ea_idebug(inode
, "name=%d.%s, buffer=%p, buffer_size=%ld",
272 name_index
, name
, buffer
, (long)buffer_size
);
275 if (!EXT4_I(inode
)->i_file_acl
)
277 ea_idebug(inode
, "reading block %llu",
278 (unsigned long long)EXT4_I(inode
)->i_file_acl
);
279 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
282 ea_bdebug(bh
, "b_count=%d, refcount=%d",
283 atomic_read(&(bh
->b_count
)), le32_to_cpu(BHDR(bh
)->h_refcount
));
284 if (ext4_xattr_check_block(inode
, bh
)) {
286 EXT4_ERROR_INODE(inode
, "bad block %llu",
287 EXT4_I(inode
)->i_file_acl
);
291 ext4_xattr_cache_insert(ext4_mb_cache
, bh
);
293 error
= ext4_xattr_find_entry(&entry
, name_index
, name
, bh
->b_size
, 1);
298 size
= le32_to_cpu(entry
->e_value_size
);
301 if (size
> buffer_size
)
303 memcpy(buffer
, bh
->b_data
+ le16_to_cpu(entry
->e_value_offs
),
314 ext4_xattr_ibody_get(struct inode
*inode
, int name_index
, const char *name
,
315 void *buffer
, size_t buffer_size
)
317 struct ext4_xattr_ibody_header
*header
;
318 struct ext4_xattr_entry
*entry
;
319 struct ext4_inode
*raw_inode
;
320 struct ext4_iloc iloc
;
325 if (!ext4_test_inode_state(inode
, EXT4_STATE_XATTR
))
327 error
= ext4_get_inode_loc(inode
, &iloc
);
330 raw_inode
= ext4_raw_inode(&iloc
);
331 header
= IHDR(inode
, raw_inode
);
332 entry
= IFIRST(header
);
333 end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
334 error
= ext4_xattr_check_names(entry
, end
);
337 error
= ext4_xattr_find_entry(&entry
, name_index
, name
,
338 end
- (void *)entry
, 0);
341 size
= le32_to_cpu(entry
->e_value_size
);
344 if (size
> buffer_size
)
346 memcpy(buffer
, (void *)IFIRST(header
) +
347 le16_to_cpu(entry
->e_value_offs
), size
);
359 * Copy an extended attribute into the buffer
360 * provided, or compute the buffer size required.
361 * Buffer is NULL to compute the size of the buffer required.
363 * Returns a negative error number on failure, or the number of bytes
364 * used / required on success.
367 ext4_xattr_get(struct inode
*inode
, int name_index
, const char *name
,
368 void *buffer
, size_t buffer_size
)
372 down_read(&EXT4_I(inode
)->xattr_sem
);
373 error
= ext4_xattr_ibody_get(inode
, name_index
, name
, buffer
,
375 if (error
== -ENODATA
)
376 error
= ext4_xattr_block_get(inode
, name_index
, name
, buffer
,
378 up_read(&EXT4_I(inode
)->xattr_sem
);
383 ext4_xattr_list_entries(struct dentry
*dentry
, struct ext4_xattr_entry
*entry
,
384 char *buffer
, size_t buffer_size
)
386 size_t rest
= buffer_size
;
388 for (; !IS_LAST_ENTRY(entry
); entry
= EXT4_XATTR_NEXT(entry
)) {
389 const struct xattr_handler
*handler
=
390 ext4_xattr_handler(entry
->e_name_index
);
393 size_t size
= handler
->list(dentry
, buffer
, rest
,
405 return buffer_size
- rest
;
409 ext4_xattr_block_list(struct dentry
*dentry
, char *buffer
, size_t buffer_size
)
411 struct inode
*inode
= dentry
->d_inode
;
412 struct buffer_head
*bh
= NULL
;
414 struct mb_cache
*ext4_mb_cache
= EXT4_GET_MB_CACHE(inode
);
416 ea_idebug(inode
, "buffer=%p, buffer_size=%ld",
417 buffer
, (long)buffer_size
);
420 if (!EXT4_I(inode
)->i_file_acl
)
422 ea_idebug(inode
, "reading block %llu",
423 (unsigned long long)EXT4_I(inode
)->i_file_acl
);
424 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
428 ea_bdebug(bh
, "b_count=%d, refcount=%d",
429 atomic_read(&(bh
->b_count
)), le32_to_cpu(BHDR(bh
)->h_refcount
));
430 if (ext4_xattr_check_block(inode
, bh
)) {
431 EXT4_ERROR_INODE(inode
, "bad block %llu",
432 EXT4_I(inode
)->i_file_acl
);
436 ext4_xattr_cache_insert(ext4_mb_cache
, bh
);
437 error
= ext4_xattr_list_entries(dentry
, BFIRST(bh
), buffer
, buffer_size
);
446 ext4_xattr_ibody_list(struct dentry
*dentry
, char *buffer
, size_t buffer_size
)
448 struct inode
*inode
= dentry
->d_inode
;
449 struct ext4_xattr_ibody_header
*header
;
450 struct ext4_inode
*raw_inode
;
451 struct ext4_iloc iloc
;
455 if (!ext4_test_inode_state(inode
, EXT4_STATE_XATTR
))
457 error
= ext4_get_inode_loc(inode
, &iloc
);
460 raw_inode
= ext4_raw_inode(&iloc
);
461 header
= IHDR(inode
, raw_inode
);
462 end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
463 error
= ext4_xattr_check_names(IFIRST(header
), end
);
466 error
= ext4_xattr_list_entries(dentry
, IFIRST(header
),
467 buffer
, buffer_size
);
477 * Copy a list of attribute names into the buffer
478 * provided, or compute the buffer size required.
479 * Buffer is NULL to compute the size of the buffer required.
481 * Returns a negative error number on failure, or the number of bytes
482 * used / required on success.
485 ext4_xattr_list(struct dentry
*dentry
, char *buffer
, size_t buffer_size
)
489 down_read(&EXT4_I(dentry
->d_inode
)->xattr_sem
);
490 ret
= ret2
= ext4_xattr_ibody_list(dentry
, buffer
, buffer_size
);
497 ret
= ext4_xattr_block_list(dentry
, buffer
, buffer_size
);
502 up_read(&EXT4_I(dentry
->d_inode
)->xattr_sem
);
507 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is
510 static void ext4_xattr_update_super_block(handle_t
*handle
,
511 struct super_block
*sb
)
513 if (EXT4_HAS_COMPAT_FEATURE(sb
, EXT4_FEATURE_COMPAT_EXT_ATTR
))
516 if (ext4_journal_get_write_access(handle
, EXT4_SB(sb
)->s_sbh
) == 0) {
517 EXT4_SET_COMPAT_FEATURE(sb
, EXT4_FEATURE_COMPAT_EXT_ATTR
);
518 ext4_handle_dirty_super(handle
, sb
);
523 * Release the xattr block BH: If the reference count is > 1, decrement it;
524 * otherwise free the block.
527 ext4_xattr_release_block(handle_t
*handle
, struct inode
*inode
,
528 struct buffer_head
*bh
)
530 struct mb_cache_entry
*ce
= NULL
;
532 struct mb_cache
*ext4_mb_cache
= EXT4_GET_MB_CACHE(inode
);
534 ce
= mb_cache_entry_get(ext4_mb_cache
, bh
->b_bdev
, bh
->b_blocknr
);
535 error
= ext4_journal_get_write_access(handle
, bh
);
540 if (BHDR(bh
)->h_refcount
== cpu_to_le32(1)) {
541 ea_bdebug(bh
, "refcount now=0; freeing");
543 mb_cache_entry_free(ce
);
546 ext4_free_blocks(handle
, inode
, bh
, 0, 1,
547 EXT4_FREE_BLOCKS_METADATA
|
548 EXT4_FREE_BLOCKS_FORGET
);
550 le32_add_cpu(&BHDR(bh
)->h_refcount
, -1);
552 mb_cache_entry_release(ce
);
554 * Beware of this ugliness: Releasing of xattr block references
555 * from different inodes can race and so we have to protect
556 * from a race where someone else frees the block (and releases
557 * its journal_head) before we are done dirtying the buffer. In
558 * nojournal mode this race is harmless and we actually cannot
559 * call ext4_handle_dirty_xattr_block() with locked buffer as
560 * that function can call sync_dirty_buffer() so for that case
561 * we handle the dirtying after unlocking the buffer.
563 if (ext4_handle_valid(handle
))
564 error
= ext4_handle_dirty_xattr_block(handle
, inode
,
567 if (!ext4_handle_valid(handle
))
568 error
= ext4_handle_dirty_xattr_block(handle
, inode
,
571 ext4_handle_sync(handle
);
572 dquot_free_block(inode
, EXT4_C2B(EXT4_SB(inode
->i_sb
), 1));
573 ea_bdebug(bh
, "refcount now=%d; releasing",
574 le32_to_cpu(BHDR(bh
)->h_refcount
));
577 ext4_std_error(inode
->i_sb
, error
);
582 * Find the available free space for EAs. This also returns the total number of
583 * bytes used by EA entries.
585 static size_t ext4_xattr_free_space(struct ext4_xattr_entry
*last
,
586 size_t *min_offs
, void *base
, int *total
)
588 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
589 if (!last
->e_value_block
&& last
->e_value_size
) {
590 size_t offs
= le16_to_cpu(last
->e_value_offs
);
591 if (offs
< *min_offs
)
595 *total
+= EXT4_XATTR_LEN(last
->e_name_len
);
597 return (*min_offs
- ((void *)last
- base
) - sizeof(__u32
));
601 ext4_xattr_set_entry(struct ext4_xattr_info
*i
, struct ext4_xattr_search
*s
)
603 struct ext4_xattr_entry
*last
;
604 size_t free
, min_offs
= s
->end
- s
->base
, name_len
= strlen(i
->name
);
606 /* Compute min_offs and last. */
608 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
609 if (!last
->e_value_block
&& last
->e_value_size
) {
610 size_t offs
= le16_to_cpu(last
->e_value_offs
);
615 free
= min_offs
- ((void *)last
- s
->base
) - sizeof(__u32
);
617 if (!s
->here
->e_value_block
&& s
->here
->e_value_size
) {
618 size_t size
= le32_to_cpu(s
->here
->e_value_size
);
619 free
+= EXT4_XATTR_SIZE(size
);
621 free
+= EXT4_XATTR_LEN(name_len
);
624 if (free
< EXT4_XATTR_SIZE(i
->value_len
) ||
625 free
< EXT4_XATTR_LEN(name_len
) +
626 EXT4_XATTR_SIZE(i
->value_len
))
630 if (i
->value
&& s
->not_found
) {
631 /* Insert the new name. */
632 size_t size
= EXT4_XATTR_LEN(name_len
);
633 size_t rest
= (void *)last
- (void *)s
->here
+ sizeof(__u32
);
634 memmove((void *)s
->here
+ size
, s
->here
, rest
);
635 memset(s
->here
, 0, size
);
636 s
->here
->e_name_index
= i
->name_index
;
637 s
->here
->e_name_len
= name_len
;
638 memcpy(s
->here
->e_name
, i
->name
, name_len
);
640 if (!s
->here
->e_value_block
&& s
->here
->e_value_size
) {
641 void *first_val
= s
->base
+ min_offs
;
642 size_t offs
= le16_to_cpu(s
->here
->e_value_offs
);
643 void *val
= s
->base
+ offs
;
644 size_t size
= EXT4_XATTR_SIZE(
645 le32_to_cpu(s
->here
->e_value_size
));
647 if (i
->value
&& size
== EXT4_XATTR_SIZE(i
->value_len
)) {
648 /* The old and the new value have the same
649 size. Just replace. */
650 s
->here
->e_value_size
=
651 cpu_to_le32(i
->value_len
);
652 if (i
->value
== EXT4_ZERO_XATTR_VALUE
) {
653 memset(val
, 0, size
);
655 /* Clear pad bytes first. */
656 memset(val
+ size
- EXT4_XATTR_PAD
, 0,
658 memcpy(val
, i
->value
, i
->value_len
);
663 /* Remove the old value. */
664 memmove(first_val
+ size
, first_val
, val
- first_val
);
665 memset(first_val
, 0, size
);
666 s
->here
->e_value_size
= 0;
667 s
->here
->e_value_offs
= 0;
670 /* Adjust all value offsets. */
672 while (!IS_LAST_ENTRY(last
)) {
673 size_t o
= le16_to_cpu(last
->e_value_offs
);
674 if (!last
->e_value_block
&&
675 last
->e_value_size
&& o
< offs
)
677 cpu_to_le16(o
+ size
);
678 last
= EXT4_XATTR_NEXT(last
);
682 /* Remove the old name. */
683 size_t size
= EXT4_XATTR_LEN(name_len
);
684 last
= ENTRY((void *)last
- size
);
685 memmove(s
->here
, (void *)s
->here
+ size
,
686 (void *)last
- (void *)s
->here
+ sizeof(__u32
));
687 memset(last
, 0, size
);
692 /* Insert the new value. */
693 s
->here
->e_value_size
= cpu_to_le32(i
->value_len
);
695 size_t size
= EXT4_XATTR_SIZE(i
->value_len
);
696 void *val
= s
->base
+ min_offs
- size
;
697 s
->here
->e_value_offs
= cpu_to_le16(min_offs
- size
);
698 if (i
->value
== EXT4_ZERO_XATTR_VALUE
) {
699 memset(val
, 0, size
);
701 /* Clear the pad bytes first. */
702 memset(val
+ size
- EXT4_XATTR_PAD
, 0,
704 memcpy(val
, i
->value
, i
->value_len
);
711 struct ext4_xattr_block_find
{
712 struct ext4_xattr_search s
;
713 struct buffer_head
*bh
;
717 ext4_xattr_block_find(struct inode
*inode
, struct ext4_xattr_info
*i
,
718 struct ext4_xattr_block_find
*bs
)
720 struct super_block
*sb
= inode
->i_sb
;
723 ea_idebug(inode
, "name=%d.%s, value=%p, value_len=%ld",
724 i
->name_index
, i
->name
, i
->value
, (long)i
->value_len
);
726 if (EXT4_I(inode
)->i_file_acl
) {
727 /* The inode already has an extended attribute block. */
728 bs
->bh
= sb_bread(sb
, EXT4_I(inode
)->i_file_acl
);
732 ea_bdebug(bs
->bh
, "b_count=%d, refcount=%d",
733 atomic_read(&(bs
->bh
->b_count
)),
734 le32_to_cpu(BHDR(bs
->bh
)->h_refcount
));
735 if (ext4_xattr_check_block(inode
, bs
->bh
)) {
736 EXT4_ERROR_INODE(inode
, "bad block %llu",
737 EXT4_I(inode
)->i_file_acl
);
741 /* Find the named attribute. */
742 bs
->s
.base
= BHDR(bs
->bh
);
743 bs
->s
.first
= BFIRST(bs
->bh
);
744 bs
->s
.end
= bs
->bh
->b_data
+ bs
->bh
->b_size
;
745 bs
->s
.here
= bs
->s
.first
;
746 error
= ext4_xattr_find_entry(&bs
->s
.here
, i
->name_index
,
747 i
->name
, bs
->bh
->b_size
, 1);
748 if (error
&& error
!= -ENODATA
)
750 bs
->s
.not_found
= error
;
759 ext4_xattr_block_set(handle_t
*handle
, struct inode
*inode
,
760 struct ext4_xattr_info
*i
,
761 struct ext4_xattr_block_find
*bs
)
763 struct super_block
*sb
= inode
->i_sb
;
764 struct buffer_head
*new_bh
= NULL
;
765 struct ext4_xattr_search
*s
= &bs
->s
;
766 struct mb_cache_entry
*ce
= NULL
;
768 struct mb_cache
*ext4_mb_cache
= EXT4_GET_MB_CACHE(inode
);
770 #define header(x) ((struct ext4_xattr_header *)(x))
772 if (i
->value
&& i
->value_len
> sb
->s_blocksize
)
775 ce
= mb_cache_entry_get(ext4_mb_cache
, bs
->bh
->b_bdev
,
777 error
= ext4_journal_get_write_access(handle
, bs
->bh
);
782 if (header(s
->base
)->h_refcount
== cpu_to_le32(1)) {
784 mb_cache_entry_free(ce
);
787 ea_bdebug(bs
->bh
, "modifying in-place");
788 error
= ext4_xattr_set_entry(i
, s
);
790 if (!IS_LAST_ENTRY(s
->first
))
791 ext4_xattr_rehash(header(s
->base
),
793 ext4_xattr_cache_insert(ext4_mb_cache
,
796 unlock_buffer(bs
->bh
);
800 error
= ext4_handle_dirty_xattr_block(handle
,
807 int offset
= (char *)s
->here
- bs
->bh
->b_data
;
809 unlock_buffer(bs
->bh
);
811 mb_cache_entry_release(ce
);
814 ea_bdebug(bs
->bh
, "cloning");
815 s
->base
= kmalloc(bs
->bh
->b_size
, GFP_NOFS
);
819 memcpy(s
->base
, BHDR(bs
->bh
), bs
->bh
->b_size
);
820 s
->first
= ENTRY(header(s
->base
)+1);
821 header(s
->base
)->h_refcount
= cpu_to_le32(1);
822 s
->here
= ENTRY(s
->base
+ offset
);
823 s
->end
= s
->base
+ bs
->bh
->b_size
;
826 /* Allocate a buffer where we construct the new block. */
827 s
->base
= kzalloc(sb
->s_blocksize
, GFP_NOFS
);
828 /* assert(header == s->base) */
832 header(s
->base
)->h_magic
= cpu_to_le32(EXT4_XATTR_MAGIC
);
833 header(s
->base
)->h_blocks
= cpu_to_le32(1);
834 header(s
->base
)->h_refcount
= cpu_to_le32(1);
835 s
->first
= ENTRY(header(s
->base
)+1);
836 s
->here
= ENTRY(header(s
->base
)+1);
837 s
->end
= s
->base
+ sb
->s_blocksize
;
840 error
= ext4_xattr_set_entry(i
, s
);
845 if (!IS_LAST_ENTRY(s
->first
))
846 ext4_xattr_rehash(header(s
->base
), s
->here
);
849 if (!IS_LAST_ENTRY(s
->first
)) {
850 new_bh
= ext4_xattr_cache_find(inode
, header(s
->base
), &ce
);
852 /* We found an identical block in the cache. */
853 if (new_bh
== bs
->bh
)
854 ea_bdebug(new_bh
, "keeping");
856 /* The old block is released after updating
858 error
= dquot_alloc_block(inode
,
859 EXT4_C2B(EXT4_SB(sb
), 1));
862 error
= ext4_journal_get_write_access(handle
,
867 le32_add_cpu(&BHDR(new_bh
)->h_refcount
, 1);
868 ea_bdebug(new_bh
, "reusing; refcount now=%d",
869 le32_to_cpu(BHDR(new_bh
)->h_refcount
));
870 unlock_buffer(new_bh
);
871 error
= ext4_handle_dirty_xattr_block(handle
,
877 mb_cache_entry_release(ce
);
879 } else if (bs
->bh
&& s
->base
== bs
->bh
->b_data
) {
880 /* We were modifying this block in-place. */
881 ea_bdebug(bs
->bh
, "keeping this block");
885 /* We need to allocate a new block */
886 ext4_fsblk_t goal
, block
;
888 goal
= ext4_group_first_block_no(sb
,
889 EXT4_I(inode
)->i_block_group
);
891 /* non-extent files can't have physical blocks past 2^32 */
892 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)))
893 goal
= goal
& EXT4_MAX_BLOCK_FILE_PHYS
;
896 * take i_data_sem because we will test
897 * i_delalloc_reserved_flag in ext4_mb_new_blocks
899 down_read((&EXT4_I(inode
)->i_data_sem
));
900 block
= ext4_new_meta_blocks(handle
, inode
, goal
, 0,
902 up_read((&EXT4_I(inode
)->i_data_sem
));
906 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)))
907 BUG_ON(block
> EXT4_MAX_BLOCK_FILE_PHYS
);
909 ea_idebug(inode
, "creating block %llu",
910 (unsigned long long)block
);
912 new_bh
= sb_getblk(sb
, block
);
913 if (unlikely(!new_bh
)) {
916 ext4_free_blocks(handle
, inode
, NULL
, block
, 1,
917 EXT4_FREE_BLOCKS_METADATA
);
921 error
= ext4_journal_get_create_access(handle
, new_bh
);
923 unlock_buffer(new_bh
);
927 memcpy(new_bh
->b_data
, s
->base
, new_bh
->b_size
);
928 set_buffer_uptodate(new_bh
);
929 unlock_buffer(new_bh
);
930 ext4_xattr_cache_insert(ext4_mb_cache
, new_bh
);
931 error
= ext4_handle_dirty_xattr_block(handle
,
938 /* Update the inode. */
939 EXT4_I(inode
)->i_file_acl
= new_bh
? new_bh
->b_blocknr
: 0;
941 /* Drop the previous xattr block. */
942 if (bs
->bh
&& bs
->bh
!= new_bh
)
943 ext4_xattr_release_block(handle
, inode
, bs
->bh
);
948 mb_cache_entry_release(ce
);
950 if (!(bs
->bh
&& s
->base
== bs
->bh
->b_data
))
956 dquot_free_block(inode
, EXT4_C2B(EXT4_SB(sb
), 1));
960 EXT4_ERROR_INODE(inode
, "bad block %llu",
961 EXT4_I(inode
)->i_file_acl
);
967 int ext4_xattr_ibody_find(struct inode
*inode
, struct ext4_xattr_info
*i
,
968 struct ext4_xattr_ibody_find
*is
)
970 struct ext4_xattr_ibody_header
*header
;
971 struct ext4_inode
*raw_inode
;
974 if (EXT4_I(inode
)->i_extra_isize
== 0)
976 raw_inode
= ext4_raw_inode(&is
->iloc
);
977 header
= IHDR(inode
, raw_inode
);
978 is
->s
.base
= is
->s
.first
= IFIRST(header
);
979 is
->s
.here
= is
->s
.first
;
980 is
->s
.end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
981 if (ext4_test_inode_state(inode
, EXT4_STATE_XATTR
)) {
982 error
= ext4_xattr_check_names(IFIRST(header
), is
->s
.end
);
985 /* Find the named attribute. */
986 error
= ext4_xattr_find_entry(&is
->s
.here
, i
->name_index
,
988 (void *)is
->s
.base
, 0);
989 if (error
&& error
!= -ENODATA
)
991 is
->s
.not_found
= error
;
996 int ext4_xattr_ibody_inline_set(handle_t
*handle
, struct inode
*inode
,
997 struct ext4_xattr_info
*i
,
998 struct ext4_xattr_ibody_find
*is
)
1000 struct ext4_xattr_ibody_header
*header
;
1001 struct ext4_xattr_search
*s
= &is
->s
;
1004 if (EXT4_I(inode
)->i_extra_isize
== 0)
1006 error
= ext4_xattr_set_entry(i
, s
);
1008 if (error
== -ENOSPC
&&
1009 ext4_has_inline_data(inode
)) {
1010 error
= ext4_try_to_evict_inline_data(handle
, inode
,
1011 EXT4_XATTR_LEN(strlen(i
->name
) +
1012 EXT4_XATTR_SIZE(i
->value_len
)));
1015 error
= ext4_xattr_ibody_find(inode
, i
, is
);
1018 error
= ext4_xattr_set_entry(i
, s
);
1023 header
= IHDR(inode
, ext4_raw_inode(&is
->iloc
));
1024 if (!IS_LAST_ENTRY(s
->first
)) {
1025 header
->h_magic
= cpu_to_le32(EXT4_XATTR_MAGIC
);
1026 ext4_set_inode_state(inode
, EXT4_STATE_XATTR
);
1028 header
->h_magic
= cpu_to_le32(0);
1029 ext4_clear_inode_state(inode
, EXT4_STATE_XATTR
);
1034 static int ext4_xattr_ibody_set(handle_t
*handle
, struct inode
*inode
,
1035 struct ext4_xattr_info
*i
,
1036 struct ext4_xattr_ibody_find
*is
)
1038 struct ext4_xattr_ibody_header
*header
;
1039 struct ext4_xattr_search
*s
= &is
->s
;
1042 if (EXT4_I(inode
)->i_extra_isize
== 0)
1044 error
= ext4_xattr_set_entry(i
, s
);
1047 header
= IHDR(inode
, ext4_raw_inode(&is
->iloc
));
1048 if (!IS_LAST_ENTRY(s
->first
)) {
1049 header
->h_magic
= cpu_to_le32(EXT4_XATTR_MAGIC
);
1050 ext4_set_inode_state(inode
, EXT4_STATE_XATTR
);
1052 header
->h_magic
= cpu_to_le32(0);
1053 ext4_clear_inode_state(inode
, EXT4_STATE_XATTR
);
1059 * ext4_xattr_set_handle()
1061 * Create, replace or remove an extended attribute for this inode. Value
1062 * is NULL to remove an existing extended attribute, and non-NULL to
1063 * either replace an existing extended attribute, or create a new extended
1064 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
1065 * specify that an extended attribute must exist and must not exist
1066 * previous to the call, respectively.
1068 * Returns 0, or a negative error number on failure.
1071 ext4_xattr_set_handle(handle_t
*handle
, struct inode
*inode
, int name_index
,
1072 const char *name
, const void *value
, size_t value_len
,
1075 struct ext4_xattr_info i
= {
1076 .name_index
= name_index
,
1079 .value_len
= value_len
,
1082 struct ext4_xattr_ibody_find is
= {
1083 .s
= { .not_found
= -ENODATA
, },
1085 struct ext4_xattr_block_find bs
= {
1086 .s
= { .not_found
= -ENODATA
, },
1088 unsigned long no_expand
;
1093 if (strlen(name
) > 255)
1095 down_write(&EXT4_I(inode
)->xattr_sem
);
1096 no_expand
= ext4_test_inode_state(inode
, EXT4_STATE_NO_EXPAND
);
1097 ext4_set_inode_state(inode
, EXT4_STATE_NO_EXPAND
);
1099 error
= ext4_reserve_inode_write(handle
, inode
, &is
.iloc
);
1103 if (ext4_test_inode_state(inode
, EXT4_STATE_NEW
)) {
1104 struct ext4_inode
*raw_inode
= ext4_raw_inode(&is
.iloc
);
1105 memset(raw_inode
, 0, EXT4_SB(inode
->i_sb
)->s_inode_size
);
1106 ext4_clear_inode_state(inode
, EXT4_STATE_NEW
);
1109 error
= ext4_xattr_ibody_find(inode
, &i
, &is
);
1113 error
= ext4_xattr_block_find(inode
, &i
, &bs
);
1116 if (is
.s
.not_found
&& bs
.s
.not_found
) {
1118 if (flags
& XATTR_REPLACE
)
1125 if (flags
& XATTR_CREATE
)
1129 if (!is
.s
.not_found
)
1130 error
= ext4_xattr_ibody_set(handle
, inode
, &i
, &is
);
1131 else if (!bs
.s
.not_found
)
1132 error
= ext4_xattr_block_set(handle
, inode
, &i
, &bs
);
1134 error
= ext4_xattr_ibody_set(handle
, inode
, &i
, &is
);
1135 if (!error
&& !bs
.s
.not_found
) {
1137 error
= ext4_xattr_block_set(handle
, inode
, &i
, &bs
);
1138 } else if (error
== -ENOSPC
) {
1139 if (EXT4_I(inode
)->i_file_acl
&& !bs
.s
.base
) {
1140 error
= ext4_xattr_block_find(inode
, &i
, &bs
);
1144 error
= ext4_xattr_block_set(handle
, inode
, &i
, &bs
);
1147 if (!is
.s
.not_found
) {
1149 error
= ext4_xattr_ibody_set(handle
, inode
, &i
,
1155 ext4_xattr_update_super_block(handle
, inode
->i_sb
);
1156 inode
->i_ctime
= ext4_current_time(inode
);
1158 ext4_clear_inode_state(inode
, EXT4_STATE_NO_EXPAND
);
1159 error
= ext4_mark_iloc_dirty(handle
, inode
, &is
.iloc
);
1161 * The bh is consumed by ext4_mark_iloc_dirty, even with
1166 ext4_handle_sync(handle
);
1173 ext4_clear_inode_state(inode
, EXT4_STATE_NO_EXPAND
);
1174 up_write(&EXT4_I(inode
)->xattr_sem
);
1181 * Like ext4_xattr_set_handle, but start from an inode. This extended
1182 * attribute modification is a filesystem transaction by itself.
1184 * Returns 0, or a negative error number on failure.
1187 ext4_xattr_set(struct inode
*inode
, int name_index
, const char *name
,
1188 const void *value
, size_t value_len
, int flags
)
1191 int error
, retries
= 0;
1192 int credits
= ext4_jbd2_credits_xattr(inode
);
1195 handle
= ext4_journal_start(inode
, EXT4_HT_XATTR
, credits
);
1196 if (IS_ERR(handle
)) {
1197 error
= PTR_ERR(handle
);
1201 error
= ext4_xattr_set_handle(handle
, inode
, name_index
, name
,
1202 value
, value_len
, flags
);
1203 error2
= ext4_journal_stop(handle
);
1204 if (error
== -ENOSPC
&&
1205 ext4_should_retry_alloc(inode
->i_sb
, &retries
))
1215 * Shift the EA entries in the inode to create space for the increased
1218 static void ext4_xattr_shift_entries(struct ext4_xattr_entry
*entry
,
1219 int value_offs_shift
, void *to
,
1220 void *from
, size_t n
, int blocksize
)
1222 struct ext4_xattr_entry
*last
= entry
;
1225 /* Adjust the value offsets of the entries */
1226 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
1227 if (!last
->e_value_block
&& last
->e_value_size
) {
1228 new_offs
= le16_to_cpu(last
->e_value_offs
) +
1230 BUG_ON(new_offs
+ le32_to_cpu(last
->e_value_size
)
1232 last
->e_value_offs
= cpu_to_le16(new_offs
);
1235 /* Shift the entries by n bytes */
1236 memmove(to
, from
, n
);
1240 * Expand an inode by new_extra_isize bytes when EAs are present.
1241 * Returns 0 on success or negative error number on failure.
1243 int ext4_expand_extra_isize_ea(struct inode
*inode
, int new_extra_isize
,
1244 struct ext4_inode
*raw_inode
, handle_t
*handle
)
1246 struct ext4_xattr_ibody_header
*header
;
1247 struct ext4_xattr_entry
*entry
, *last
, *first
;
1248 struct buffer_head
*bh
= NULL
;
1249 struct ext4_xattr_ibody_find
*is
= NULL
;
1250 struct ext4_xattr_block_find
*bs
= NULL
;
1251 char *buffer
= NULL
, *b_entry_name
= NULL
;
1252 size_t min_offs
, free
;
1254 void *base
, *start
, *end
;
1255 int extra_isize
= 0, error
= 0, tried_min_extra_isize
= 0;
1256 int s_min_extra_isize
= le16_to_cpu(EXT4_SB(inode
->i_sb
)->s_es
->s_min_extra_isize
);
1258 down_write(&EXT4_I(inode
)->xattr_sem
);
1260 if (EXT4_I(inode
)->i_extra_isize
>= new_extra_isize
) {
1261 up_write(&EXT4_I(inode
)->xattr_sem
);
1265 header
= IHDR(inode
, raw_inode
);
1266 entry
= IFIRST(header
);
1269 * Check if enough free space is available in the inode to shift the
1270 * entries ahead by new_extra_isize.
1273 base
= start
= entry
;
1274 end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
1275 min_offs
= end
- base
;
1277 total_ino
= sizeof(struct ext4_xattr_ibody_header
);
1279 free
= ext4_xattr_free_space(last
, &min_offs
, base
, &total_ino
);
1280 if (free
>= new_extra_isize
) {
1281 entry
= IFIRST(header
);
1282 ext4_xattr_shift_entries(entry
, EXT4_I(inode
)->i_extra_isize
1283 - new_extra_isize
, (void *)raw_inode
+
1284 EXT4_GOOD_OLD_INODE_SIZE
+ new_extra_isize
,
1285 (void *)header
, total_ino
,
1286 inode
->i_sb
->s_blocksize
);
1287 EXT4_I(inode
)->i_extra_isize
= new_extra_isize
;
1293 * Enough free space isn't available in the inode, check if
1294 * EA block can hold new_extra_isize bytes.
1296 if (EXT4_I(inode
)->i_file_acl
) {
1297 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
1301 if (ext4_xattr_check_block(inode
, bh
)) {
1302 EXT4_ERROR_INODE(inode
, "bad block %llu",
1303 EXT4_I(inode
)->i_file_acl
);
1309 end
= bh
->b_data
+ bh
->b_size
;
1310 min_offs
= end
- base
;
1311 free
= ext4_xattr_free_space(first
, &min_offs
, base
, NULL
);
1312 if (free
< new_extra_isize
) {
1313 if (!tried_min_extra_isize
&& s_min_extra_isize
) {
1314 tried_min_extra_isize
++;
1315 new_extra_isize
= s_min_extra_isize
;
1323 free
= inode
->i_sb
->s_blocksize
;
1326 while (new_extra_isize
> 0) {
1327 size_t offs
, size
, entry_size
;
1328 struct ext4_xattr_entry
*small_entry
= NULL
;
1329 struct ext4_xattr_info i
= {
1333 unsigned int total_size
; /* EA entry size + value size */
1334 unsigned int shift_bytes
; /* No. of bytes to shift EAs by? */
1335 unsigned int min_total_size
= ~0U;
1337 is
= kzalloc(sizeof(struct ext4_xattr_ibody_find
), GFP_NOFS
);
1338 bs
= kzalloc(sizeof(struct ext4_xattr_block_find
), GFP_NOFS
);
1344 is
->s
.not_found
= -ENODATA
;
1345 bs
->s
.not_found
= -ENODATA
;
1349 last
= IFIRST(header
);
1350 /* Find the entry best suited to be pushed into EA block */
1352 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
1354 EXT4_XATTR_SIZE(le32_to_cpu(last
->e_value_size
)) +
1355 EXT4_XATTR_LEN(last
->e_name_len
);
1356 if (total_size
<= free
&& total_size
< min_total_size
) {
1357 if (total_size
< new_extra_isize
) {
1361 min_total_size
= total_size
;
1366 if (entry
== NULL
) {
1368 entry
= small_entry
;
1370 if (!tried_min_extra_isize
&&
1371 s_min_extra_isize
) {
1372 tried_min_extra_isize
++;
1373 new_extra_isize
= s_min_extra_isize
;
1374 kfree(is
); is
= NULL
;
1375 kfree(bs
); bs
= NULL
;
1383 offs
= le16_to_cpu(entry
->e_value_offs
);
1384 size
= le32_to_cpu(entry
->e_value_size
);
1385 entry_size
= EXT4_XATTR_LEN(entry
->e_name_len
);
1386 i
.name_index
= entry
->e_name_index
,
1387 buffer
= kmalloc(EXT4_XATTR_SIZE(size
), GFP_NOFS
);
1388 b_entry_name
= kmalloc(entry
->e_name_len
+ 1, GFP_NOFS
);
1389 if (!buffer
|| !b_entry_name
) {
1393 /* Save the entry name and the entry value */
1394 memcpy(buffer
, (void *)IFIRST(header
) + offs
,
1395 EXT4_XATTR_SIZE(size
));
1396 memcpy(b_entry_name
, entry
->e_name
, entry
->e_name_len
);
1397 b_entry_name
[entry
->e_name_len
] = '\0';
1398 i
.name
= b_entry_name
;
1400 error
= ext4_get_inode_loc(inode
, &is
->iloc
);
1404 error
= ext4_xattr_ibody_find(inode
, &i
, is
);
1408 /* Remove the chosen entry from the inode */
1409 error
= ext4_xattr_ibody_set(handle
, inode
, &i
, is
);
1413 entry
= IFIRST(header
);
1414 if (entry_size
+ EXT4_XATTR_SIZE(size
) >= new_extra_isize
)
1415 shift_bytes
= new_extra_isize
;
1417 shift_bytes
= entry_size
+ size
;
1418 /* Adjust the offsets and shift the remaining entries ahead */
1419 ext4_xattr_shift_entries(entry
, EXT4_I(inode
)->i_extra_isize
-
1420 shift_bytes
, (void *)raw_inode
+
1421 EXT4_GOOD_OLD_INODE_SIZE
+ extra_isize
+ shift_bytes
,
1422 (void *)header
, total_ino
- entry_size
,
1423 inode
->i_sb
->s_blocksize
);
1425 extra_isize
+= shift_bytes
;
1426 new_extra_isize
-= shift_bytes
;
1427 EXT4_I(inode
)->i_extra_isize
= extra_isize
;
1429 i
.name
= b_entry_name
;
1432 error
= ext4_xattr_block_find(inode
, &i
, bs
);
1436 /* Add entry which was removed from the inode into the block */
1437 error
= ext4_xattr_block_set(handle
, inode
, &i
, bs
);
1440 kfree(b_entry_name
);
1442 b_entry_name
= NULL
;
1444 brelse(is
->iloc
.bh
);
1449 up_write(&EXT4_I(inode
)->xattr_sem
);
1453 kfree(b_entry_name
);
1456 brelse(is
->iloc
.bh
);
1460 up_write(&EXT4_I(inode
)->xattr_sem
);
1467 * ext4_xattr_delete_inode()
1469 * Free extended attribute resources associated with this inode. This
1470 * is called immediately before an inode is freed. We have exclusive
1471 * access to the inode.
1474 ext4_xattr_delete_inode(handle_t
*handle
, struct inode
*inode
)
1476 struct buffer_head
*bh
= NULL
;
1478 if (!EXT4_I(inode
)->i_file_acl
)
1480 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
1482 EXT4_ERROR_INODE(inode
, "block %llu read error",
1483 EXT4_I(inode
)->i_file_acl
);
1486 if (BHDR(bh
)->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
) ||
1487 BHDR(bh
)->h_blocks
!= cpu_to_le32(1)) {
1488 EXT4_ERROR_INODE(inode
, "bad block %llu",
1489 EXT4_I(inode
)->i_file_acl
);
1492 ext4_xattr_release_block(handle
, inode
, bh
);
1493 EXT4_I(inode
)->i_file_acl
= 0;
1500 * ext4_xattr_put_super()
1502 * This is called when a file system is unmounted.
1505 ext4_xattr_put_super(struct super_block
*sb
)
1507 mb_cache_shrink(sb
->s_bdev
);
1511 * ext4_xattr_cache_insert()
1513 * Create a new entry in the extended attribute cache, and insert
1514 * it unless such an entry is already in the cache.
1516 * Returns 0, or a negative error number on failure.
1519 ext4_xattr_cache_insert(struct mb_cache
*ext4_mb_cache
, struct buffer_head
*bh
)
1521 __u32 hash
= le32_to_cpu(BHDR(bh
)->h_hash
);
1522 struct mb_cache_entry
*ce
;
1525 ce
= mb_cache_entry_alloc(ext4_mb_cache
, GFP_NOFS
);
1527 ea_bdebug(bh
, "out of memory");
1530 error
= mb_cache_entry_insert(ce
, bh
->b_bdev
, bh
->b_blocknr
, hash
);
1532 mb_cache_entry_free(ce
);
1533 if (error
== -EBUSY
) {
1534 ea_bdebug(bh
, "already in cache");
1538 ea_bdebug(bh
, "inserting [%x]", (int)hash
);
1539 mb_cache_entry_release(ce
);
1546 * Compare two extended attribute blocks for equality.
1548 * Returns 0 if the blocks are equal, 1 if they differ, and
1549 * a negative error number on errors.
1552 ext4_xattr_cmp(struct ext4_xattr_header
*header1
,
1553 struct ext4_xattr_header
*header2
)
1555 struct ext4_xattr_entry
*entry1
, *entry2
;
1557 entry1
= ENTRY(header1
+1);
1558 entry2
= ENTRY(header2
+1);
1559 while (!IS_LAST_ENTRY(entry1
)) {
1560 if (IS_LAST_ENTRY(entry2
))
1562 if (entry1
->e_hash
!= entry2
->e_hash
||
1563 entry1
->e_name_index
!= entry2
->e_name_index
||
1564 entry1
->e_name_len
!= entry2
->e_name_len
||
1565 entry1
->e_value_size
!= entry2
->e_value_size
||
1566 memcmp(entry1
->e_name
, entry2
->e_name
, entry1
->e_name_len
))
1568 if (entry1
->e_value_block
!= 0 || entry2
->e_value_block
!= 0)
1570 if (memcmp((char *)header1
+ le16_to_cpu(entry1
->e_value_offs
),
1571 (char *)header2
+ le16_to_cpu(entry2
->e_value_offs
),
1572 le32_to_cpu(entry1
->e_value_size
)))
1575 entry1
= EXT4_XATTR_NEXT(entry1
);
1576 entry2
= EXT4_XATTR_NEXT(entry2
);
1578 if (!IS_LAST_ENTRY(entry2
))
1584 * ext4_xattr_cache_find()
1586 * Find an identical extended attribute block.
1588 * Returns a pointer to the block found, or NULL if such a block was
1589 * not found or an error occurred.
1591 static struct buffer_head
*
1592 ext4_xattr_cache_find(struct inode
*inode
, struct ext4_xattr_header
*header
,
1593 struct mb_cache_entry
**pce
)
1595 __u32 hash
= le32_to_cpu(header
->h_hash
);
1596 struct mb_cache_entry
*ce
;
1597 struct mb_cache
*ext4_mb_cache
= EXT4_GET_MB_CACHE(inode
);
1599 if (!header
->h_hash
)
1600 return NULL
; /* never share */
1601 ea_idebug(inode
, "looking for cached blocks [%x]", (int)hash
);
1603 ce
= mb_cache_entry_find_first(ext4_mb_cache
, inode
->i_sb
->s_bdev
,
1606 struct buffer_head
*bh
;
1609 if (PTR_ERR(ce
) == -EAGAIN
)
1613 bh
= sb_bread(inode
->i_sb
, ce
->e_block
);
1615 EXT4_ERROR_INODE(inode
, "block %lu read error",
1616 (unsigned long) ce
->e_block
);
1617 } else if (le32_to_cpu(BHDR(bh
)->h_refcount
) >=
1618 EXT4_XATTR_REFCOUNT_MAX
) {
1619 ea_idebug(inode
, "block %lu refcount %d>=%d",
1620 (unsigned long) ce
->e_block
,
1621 le32_to_cpu(BHDR(bh
)->h_refcount
),
1622 EXT4_XATTR_REFCOUNT_MAX
);
1623 } else if (ext4_xattr_cmp(header
, BHDR(bh
)) == 0) {
1628 ce
= mb_cache_entry_find_next(ce
, inode
->i_sb
->s_bdev
, hash
);
1633 #define NAME_HASH_SHIFT 5
1634 #define VALUE_HASH_SHIFT 16
1637 * ext4_xattr_hash_entry()
1639 * Compute the hash of an extended attribute.
1641 static inline void ext4_xattr_hash_entry(struct ext4_xattr_header
*header
,
1642 struct ext4_xattr_entry
*entry
)
1645 char *name
= entry
->e_name
;
1648 for (n
= 0; n
< entry
->e_name_len
; n
++) {
1649 hash
= (hash
<< NAME_HASH_SHIFT
) ^
1650 (hash
>> (8*sizeof(hash
) - NAME_HASH_SHIFT
)) ^
1654 if (entry
->e_value_block
== 0 && entry
->e_value_size
!= 0) {
1655 __le32
*value
= (__le32
*)((char *)header
+
1656 le16_to_cpu(entry
->e_value_offs
));
1657 for (n
= (le32_to_cpu(entry
->e_value_size
) +
1658 EXT4_XATTR_ROUND
) >> EXT4_XATTR_PAD_BITS
; n
; n
--) {
1659 hash
= (hash
<< VALUE_HASH_SHIFT
) ^
1660 (hash
>> (8*sizeof(hash
) - VALUE_HASH_SHIFT
)) ^
1661 le32_to_cpu(*value
++);
1664 entry
->e_hash
= cpu_to_le32(hash
);
1667 #undef NAME_HASH_SHIFT
1668 #undef VALUE_HASH_SHIFT
1670 #define BLOCK_HASH_SHIFT 16
1673 * ext4_xattr_rehash()
1675 * Re-compute the extended attribute hash value after an entry has changed.
1677 static void ext4_xattr_rehash(struct ext4_xattr_header
*header
,
1678 struct ext4_xattr_entry
*entry
)
1680 struct ext4_xattr_entry
*here
;
1683 ext4_xattr_hash_entry(header
, entry
);
1684 here
= ENTRY(header
+1);
1685 while (!IS_LAST_ENTRY(here
)) {
1686 if (!here
->e_hash
) {
1687 /* Block is not shared if an entry's hash value == 0 */
1691 hash
= (hash
<< BLOCK_HASH_SHIFT
) ^
1692 (hash
>> (8*sizeof(hash
) - BLOCK_HASH_SHIFT
)) ^
1693 le32_to_cpu(here
->e_hash
);
1694 here
= EXT4_XATTR_NEXT(here
);
1696 header
->h_hash
= cpu_to_le32(hash
);
1699 #undef BLOCK_HASH_SHIFT
1701 #define HASH_BUCKET_BITS 10
1704 ext4_xattr_create_cache(char *name
)
1706 return mb_cache_create(name
, HASH_BUCKET_BITS
);
1709 void ext4_xattr_destroy_cache(struct mb_cache
*cache
)
1712 mb_cache_destroy(cache
);