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_metadata_csum(inode
->i_sb
) &&
146 (hdr
->h_checksum
!= ext4_xattr_block_csum(inode
, block_nr
, hdr
)))
151 static void ext4_xattr_block_csum_set(struct inode
*inode
,
153 struct ext4_xattr_header
*hdr
)
155 if (!ext4_has_metadata_csum(inode
->i_sb
))
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
,
194 struct ext4_xattr_entry
*e
= entry
;
196 while (!IS_LAST_ENTRY(e
)) {
197 struct ext4_xattr_entry
*next
= EXT4_XATTR_NEXT(e
);
198 if ((void *)next
>= end
)
203 while (!IS_LAST_ENTRY(entry
)) {
204 if (entry
->e_value_size
!= 0 &&
205 (value_start
+ le16_to_cpu(entry
->e_value_offs
) <
206 (void *)e
+ sizeof(__u32
) ||
207 value_start
+ le16_to_cpu(entry
->e_value_offs
) +
208 le32_to_cpu(entry
->e_value_size
) > end
))
210 entry
= EXT4_XATTR_NEXT(entry
);
217 ext4_xattr_check_block(struct inode
*inode
, struct buffer_head
*bh
)
221 if (buffer_verified(bh
))
224 if (BHDR(bh
)->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
) ||
225 BHDR(bh
)->h_blocks
!= cpu_to_le32(1))
227 if (!ext4_xattr_block_csum_verify(inode
, bh
->b_blocknr
, BHDR(bh
)))
229 error
= ext4_xattr_check_names(BFIRST(bh
), bh
->b_data
+ bh
->b_size
,
232 set_buffer_verified(bh
);
237 ext4_xattr_check_entry(struct ext4_xattr_entry
*entry
, size_t size
)
239 size_t value_size
= le32_to_cpu(entry
->e_value_size
);
241 if (entry
->e_value_block
!= 0 || value_size
> size
||
242 le16_to_cpu(entry
->e_value_offs
) + value_size
> size
)
248 ext4_xattr_find_entry(struct ext4_xattr_entry
**pentry
, int name_index
,
249 const char *name
, size_t size
, int sorted
)
251 struct ext4_xattr_entry
*entry
;
257 name_len
= strlen(name
);
259 for (; !IS_LAST_ENTRY(entry
); entry
= EXT4_XATTR_NEXT(entry
)) {
260 cmp
= name_index
- entry
->e_name_index
;
262 cmp
= name_len
- entry
->e_name_len
;
264 cmp
= memcmp(name
, entry
->e_name
, name_len
);
265 if (cmp
<= 0 && (sorted
|| cmp
== 0))
269 if (!cmp
&& ext4_xattr_check_entry(entry
, size
))
271 return cmp
? -ENODATA
: 0;
275 ext4_xattr_block_get(struct inode
*inode
, int name_index
, const char *name
,
276 void *buffer
, size_t buffer_size
)
278 struct buffer_head
*bh
= NULL
;
279 struct ext4_xattr_entry
*entry
;
282 struct mb_cache
*ext4_mb_cache
= EXT4_GET_MB_CACHE(inode
);
284 ea_idebug(inode
, "name=%d.%s, buffer=%p, buffer_size=%ld",
285 name_index
, name
, buffer
, (long)buffer_size
);
288 if (!EXT4_I(inode
)->i_file_acl
)
290 ea_idebug(inode
, "reading block %llu",
291 (unsigned long long)EXT4_I(inode
)->i_file_acl
);
292 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
295 ea_bdebug(bh
, "b_count=%d, refcount=%d",
296 atomic_read(&(bh
->b_count
)), le32_to_cpu(BHDR(bh
)->h_refcount
));
297 if (ext4_xattr_check_block(inode
, bh
)) {
299 EXT4_ERROR_INODE(inode
, "bad block %llu",
300 EXT4_I(inode
)->i_file_acl
);
304 ext4_xattr_cache_insert(ext4_mb_cache
, bh
);
306 error
= ext4_xattr_find_entry(&entry
, name_index
, name
, bh
->b_size
, 1);
311 size
= le32_to_cpu(entry
->e_value_size
);
314 if (size
> buffer_size
)
316 memcpy(buffer
, bh
->b_data
+ le16_to_cpu(entry
->e_value_offs
),
327 ext4_xattr_ibody_get(struct inode
*inode
, int name_index
, const char *name
,
328 void *buffer
, size_t buffer_size
)
330 struct ext4_xattr_ibody_header
*header
;
331 struct ext4_xattr_entry
*entry
;
332 struct ext4_inode
*raw_inode
;
333 struct ext4_iloc iloc
;
338 if (!ext4_test_inode_state(inode
, EXT4_STATE_XATTR
))
340 error
= ext4_get_inode_loc(inode
, &iloc
);
343 raw_inode
= ext4_raw_inode(&iloc
);
344 header
= IHDR(inode
, raw_inode
);
345 entry
= IFIRST(header
);
346 end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
347 error
= ext4_xattr_check_names(entry
, end
, entry
);
350 error
= ext4_xattr_find_entry(&entry
, name_index
, name
,
351 end
- (void *)entry
, 0);
354 size
= le32_to_cpu(entry
->e_value_size
);
357 if (size
> buffer_size
)
359 memcpy(buffer
, (void *)IFIRST(header
) +
360 le16_to_cpu(entry
->e_value_offs
), size
);
372 * Copy an extended attribute into the buffer
373 * provided, or compute the buffer size required.
374 * Buffer is NULL to compute the size of the buffer required.
376 * Returns a negative error number on failure, or the number of bytes
377 * used / required on success.
380 ext4_xattr_get(struct inode
*inode
, int name_index
, const char *name
,
381 void *buffer
, size_t buffer_size
)
385 if (strlen(name
) > 255)
388 down_read(&EXT4_I(inode
)->xattr_sem
);
389 error
= ext4_xattr_ibody_get(inode
, name_index
, name
, buffer
,
391 if (error
== -ENODATA
)
392 error
= ext4_xattr_block_get(inode
, name_index
, name
, buffer
,
394 up_read(&EXT4_I(inode
)->xattr_sem
);
399 ext4_xattr_list_entries(struct dentry
*dentry
, struct ext4_xattr_entry
*entry
,
400 char *buffer
, size_t buffer_size
)
402 size_t rest
= buffer_size
;
404 for (; !IS_LAST_ENTRY(entry
); entry
= EXT4_XATTR_NEXT(entry
)) {
405 const struct xattr_handler
*handler
=
406 ext4_xattr_handler(entry
->e_name_index
);
409 size_t size
= handler
->list(dentry
, buffer
, rest
,
421 return buffer_size
- rest
;
425 ext4_xattr_block_list(struct dentry
*dentry
, char *buffer
, size_t buffer_size
)
427 struct inode
*inode
= dentry
->d_inode
;
428 struct buffer_head
*bh
= NULL
;
430 struct mb_cache
*ext4_mb_cache
= EXT4_GET_MB_CACHE(inode
);
432 ea_idebug(inode
, "buffer=%p, buffer_size=%ld",
433 buffer
, (long)buffer_size
);
436 if (!EXT4_I(inode
)->i_file_acl
)
438 ea_idebug(inode
, "reading block %llu",
439 (unsigned long long)EXT4_I(inode
)->i_file_acl
);
440 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
444 ea_bdebug(bh
, "b_count=%d, refcount=%d",
445 atomic_read(&(bh
->b_count
)), le32_to_cpu(BHDR(bh
)->h_refcount
));
446 if (ext4_xattr_check_block(inode
, bh
)) {
447 EXT4_ERROR_INODE(inode
, "bad block %llu",
448 EXT4_I(inode
)->i_file_acl
);
452 ext4_xattr_cache_insert(ext4_mb_cache
, bh
);
453 error
= ext4_xattr_list_entries(dentry
, BFIRST(bh
), buffer
, buffer_size
);
462 ext4_xattr_ibody_list(struct dentry
*dentry
, char *buffer
, size_t buffer_size
)
464 struct inode
*inode
= dentry
->d_inode
;
465 struct ext4_xattr_ibody_header
*header
;
466 struct ext4_inode
*raw_inode
;
467 struct ext4_iloc iloc
;
471 if (!ext4_test_inode_state(inode
, EXT4_STATE_XATTR
))
473 error
= ext4_get_inode_loc(inode
, &iloc
);
476 raw_inode
= ext4_raw_inode(&iloc
);
477 header
= IHDR(inode
, raw_inode
);
478 end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
479 error
= ext4_xattr_check_names(IFIRST(header
), end
, IFIRST(header
));
482 error
= ext4_xattr_list_entries(dentry
, IFIRST(header
),
483 buffer
, buffer_size
);
493 * Copy a list of attribute names into the buffer
494 * provided, or compute the buffer size required.
495 * Buffer is NULL to compute the size of the buffer required.
497 * Returns a negative error number on failure, or the number of bytes
498 * used / required on success.
501 ext4_xattr_list(struct dentry
*dentry
, char *buffer
, size_t buffer_size
)
505 down_read(&EXT4_I(dentry
->d_inode
)->xattr_sem
);
506 ret
= ret2
= ext4_xattr_ibody_list(dentry
, buffer
, buffer_size
);
513 ret
= ext4_xattr_block_list(dentry
, buffer
, buffer_size
);
518 up_read(&EXT4_I(dentry
->d_inode
)->xattr_sem
);
523 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is
526 static void ext4_xattr_update_super_block(handle_t
*handle
,
527 struct super_block
*sb
)
529 if (EXT4_HAS_COMPAT_FEATURE(sb
, EXT4_FEATURE_COMPAT_EXT_ATTR
))
532 BUFFER_TRACE(EXT4_SB(sb
)->s_sbh
, "get_write_access");
533 if (ext4_journal_get_write_access(handle
, EXT4_SB(sb
)->s_sbh
) == 0) {
534 EXT4_SET_COMPAT_FEATURE(sb
, EXT4_FEATURE_COMPAT_EXT_ATTR
);
535 ext4_handle_dirty_super(handle
, sb
);
540 * Release the xattr block BH: If the reference count is > 1, decrement it;
541 * otherwise free the block.
544 ext4_xattr_release_block(handle_t
*handle
, struct inode
*inode
,
545 struct buffer_head
*bh
)
547 struct mb_cache_entry
*ce
= NULL
;
549 struct mb_cache
*ext4_mb_cache
= EXT4_GET_MB_CACHE(inode
);
551 ce
= mb_cache_entry_get(ext4_mb_cache
, bh
->b_bdev
, bh
->b_blocknr
);
552 BUFFER_TRACE(bh
, "get_write_access");
553 error
= ext4_journal_get_write_access(handle
, bh
);
558 if (BHDR(bh
)->h_refcount
== cpu_to_le32(1)) {
559 ea_bdebug(bh
, "refcount now=0; freeing");
561 mb_cache_entry_free(ce
);
564 ext4_free_blocks(handle
, inode
, bh
, 0, 1,
565 EXT4_FREE_BLOCKS_METADATA
|
566 EXT4_FREE_BLOCKS_FORGET
);
568 le32_add_cpu(&BHDR(bh
)->h_refcount
, -1);
570 mb_cache_entry_release(ce
);
572 * Beware of this ugliness: Releasing of xattr block references
573 * from different inodes can race and so we have to protect
574 * from a race where someone else frees the block (and releases
575 * its journal_head) before we are done dirtying the buffer. In
576 * nojournal mode this race is harmless and we actually cannot
577 * call ext4_handle_dirty_xattr_block() with locked buffer as
578 * that function can call sync_dirty_buffer() so for that case
579 * we handle the dirtying after unlocking the buffer.
581 if (ext4_handle_valid(handle
))
582 error
= ext4_handle_dirty_xattr_block(handle
, inode
,
585 if (!ext4_handle_valid(handle
))
586 error
= ext4_handle_dirty_xattr_block(handle
, inode
,
589 ext4_handle_sync(handle
);
590 dquot_free_block(inode
, EXT4_C2B(EXT4_SB(inode
->i_sb
), 1));
591 ea_bdebug(bh
, "refcount now=%d; releasing",
592 le32_to_cpu(BHDR(bh
)->h_refcount
));
595 ext4_std_error(inode
->i_sb
, error
);
600 * Find the available free space for EAs. This also returns the total number of
601 * bytes used by EA entries.
603 static size_t ext4_xattr_free_space(struct ext4_xattr_entry
*last
,
604 size_t *min_offs
, void *base
, int *total
)
606 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
607 if (!last
->e_value_block
&& last
->e_value_size
) {
608 size_t offs
= le16_to_cpu(last
->e_value_offs
);
609 if (offs
< *min_offs
)
613 *total
+= EXT4_XATTR_LEN(last
->e_name_len
);
615 return (*min_offs
- ((void *)last
- base
) - sizeof(__u32
));
619 ext4_xattr_set_entry(struct ext4_xattr_info
*i
, struct ext4_xattr_search
*s
)
621 struct ext4_xattr_entry
*last
;
622 size_t free
, min_offs
= s
->end
- s
->base
, name_len
= strlen(i
->name
);
624 /* Compute min_offs and last. */
626 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
627 if (!last
->e_value_block
&& last
->e_value_size
) {
628 size_t offs
= le16_to_cpu(last
->e_value_offs
);
633 free
= min_offs
- ((void *)last
- s
->base
) - sizeof(__u32
);
635 if (!s
->here
->e_value_block
&& s
->here
->e_value_size
) {
636 size_t size
= le32_to_cpu(s
->here
->e_value_size
);
637 free
+= EXT4_XATTR_SIZE(size
);
639 free
+= EXT4_XATTR_LEN(name_len
);
642 if (free
< EXT4_XATTR_SIZE(i
->value_len
) ||
643 free
< EXT4_XATTR_LEN(name_len
) +
644 EXT4_XATTR_SIZE(i
->value_len
))
648 if (i
->value
&& s
->not_found
) {
649 /* Insert the new name. */
650 size_t size
= EXT4_XATTR_LEN(name_len
);
651 size_t rest
= (void *)last
- (void *)s
->here
+ sizeof(__u32
);
652 memmove((void *)s
->here
+ size
, s
->here
, rest
);
653 memset(s
->here
, 0, size
);
654 s
->here
->e_name_index
= i
->name_index
;
655 s
->here
->e_name_len
= name_len
;
656 memcpy(s
->here
->e_name
, i
->name
, name_len
);
658 if (!s
->here
->e_value_block
&& s
->here
->e_value_size
) {
659 void *first_val
= s
->base
+ min_offs
;
660 size_t offs
= le16_to_cpu(s
->here
->e_value_offs
);
661 void *val
= s
->base
+ offs
;
662 size_t size
= EXT4_XATTR_SIZE(
663 le32_to_cpu(s
->here
->e_value_size
));
665 if (i
->value
&& size
== EXT4_XATTR_SIZE(i
->value_len
)) {
666 /* The old and the new value have the same
667 size. Just replace. */
668 s
->here
->e_value_size
=
669 cpu_to_le32(i
->value_len
);
670 if (i
->value
== EXT4_ZERO_XATTR_VALUE
) {
671 memset(val
, 0, size
);
673 /* Clear pad bytes first. */
674 memset(val
+ size
- EXT4_XATTR_PAD
, 0,
676 memcpy(val
, i
->value
, i
->value_len
);
681 /* Remove the old value. */
682 memmove(first_val
+ size
, first_val
, val
- first_val
);
683 memset(first_val
, 0, size
);
684 s
->here
->e_value_size
= 0;
685 s
->here
->e_value_offs
= 0;
688 /* Adjust all value offsets. */
690 while (!IS_LAST_ENTRY(last
)) {
691 size_t o
= le16_to_cpu(last
->e_value_offs
);
692 if (!last
->e_value_block
&&
693 last
->e_value_size
&& o
< offs
)
695 cpu_to_le16(o
+ size
);
696 last
= EXT4_XATTR_NEXT(last
);
700 /* Remove the old name. */
701 size_t size
= EXT4_XATTR_LEN(name_len
);
702 last
= ENTRY((void *)last
- size
);
703 memmove(s
->here
, (void *)s
->here
+ size
,
704 (void *)last
- (void *)s
->here
+ sizeof(__u32
));
705 memset(last
, 0, size
);
710 /* Insert the new value. */
711 s
->here
->e_value_size
= cpu_to_le32(i
->value_len
);
713 size_t size
= EXT4_XATTR_SIZE(i
->value_len
);
714 void *val
= s
->base
+ min_offs
- size
;
715 s
->here
->e_value_offs
= cpu_to_le16(min_offs
- size
);
716 if (i
->value
== EXT4_ZERO_XATTR_VALUE
) {
717 memset(val
, 0, size
);
719 /* Clear the pad bytes first. */
720 memset(val
+ size
- EXT4_XATTR_PAD
, 0,
722 memcpy(val
, i
->value
, i
->value_len
);
729 struct ext4_xattr_block_find
{
730 struct ext4_xattr_search s
;
731 struct buffer_head
*bh
;
735 ext4_xattr_block_find(struct inode
*inode
, struct ext4_xattr_info
*i
,
736 struct ext4_xattr_block_find
*bs
)
738 struct super_block
*sb
= inode
->i_sb
;
741 ea_idebug(inode
, "name=%d.%s, value=%p, value_len=%ld",
742 i
->name_index
, i
->name
, i
->value
, (long)i
->value_len
);
744 if (EXT4_I(inode
)->i_file_acl
) {
745 /* The inode already has an extended attribute block. */
746 bs
->bh
= sb_bread(sb
, EXT4_I(inode
)->i_file_acl
);
750 ea_bdebug(bs
->bh
, "b_count=%d, refcount=%d",
751 atomic_read(&(bs
->bh
->b_count
)),
752 le32_to_cpu(BHDR(bs
->bh
)->h_refcount
));
753 if (ext4_xattr_check_block(inode
, bs
->bh
)) {
754 EXT4_ERROR_INODE(inode
, "bad block %llu",
755 EXT4_I(inode
)->i_file_acl
);
759 /* Find the named attribute. */
760 bs
->s
.base
= BHDR(bs
->bh
);
761 bs
->s
.first
= BFIRST(bs
->bh
);
762 bs
->s
.end
= bs
->bh
->b_data
+ bs
->bh
->b_size
;
763 bs
->s
.here
= bs
->s
.first
;
764 error
= ext4_xattr_find_entry(&bs
->s
.here
, i
->name_index
,
765 i
->name
, bs
->bh
->b_size
, 1);
766 if (error
&& error
!= -ENODATA
)
768 bs
->s
.not_found
= error
;
777 ext4_xattr_block_set(handle_t
*handle
, struct inode
*inode
,
778 struct ext4_xattr_info
*i
,
779 struct ext4_xattr_block_find
*bs
)
781 struct super_block
*sb
= inode
->i_sb
;
782 struct buffer_head
*new_bh
= NULL
;
783 struct ext4_xattr_search
*s
= &bs
->s
;
784 struct mb_cache_entry
*ce
= NULL
;
786 struct mb_cache
*ext4_mb_cache
= EXT4_GET_MB_CACHE(inode
);
788 #define header(x) ((struct ext4_xattr_header *)(x))
790 if (i
->value
&& i
->value_len
> sb
->s_blocksize
)
793 ce
= mb_cache_entry_get(ext4_mb_cache
, bs
->bh
->b_bdev
,
795 BUFFER_TRACE(bs
->bh
, "get_write_access");
796 error
= ext4_journal_get_write_access(handle
, bs
->bh
);
801 if (header(s
->base
)->h_refcount
== cpu_to_le32(1)) {
803 mb_cache_entry_free(ce
);
806 ea_bdebug(bs
->bh
, "modifying in-place");
807 error
= ext4_xattr_set_entry(i
, s
);
809 if (!IS_LAST_ENTRY(s
->first
))
810 ext4_xattr_rehash(header(s
->base
),
812 ext4_xattr_cache_insert(ext4_mb_cache
,
815 unlock_buffer(bs
->bh
);
819 error
= ext4_handle_dirty_xattr_block(handle
,
826 int offset
= (char *)s
->here
- bs
->bh
->b_data
;
828 unlock_buffer(bs
->bh
);
830 mb_cache_entry_release(ce
);
833 ea_bdebug(bs
->bh
, "cloning");
834 s
->base
= kmalloc(bs
->bh
->b_size
, GFP_NOFS
);
838 memcpy(s
->base
, BHDR(bs
->bh
), bs
->bh
->b_size
);
839 s
->first
= ENTRY(header(s
->base
)+1);
840 header(s
->base
)->h_refcount
= cpu_to_le32(1);
841 s
->here
= ENTRY(s
->base
+ offset
);
842 s
->end
= s
->base
+ bs
->bh
->b_size
;
845 /* Allocate a buffer where we construct the new block. */
846 s
->base
= kzalloc(sb
->s_blocksize
, GFP_NOFS
);
847 /* assert(header == s->base) */
851 header(s
->base
)->h_magic
= cpu_to_le32(EXT4_XATTR_MAGIC
);
852 header(s
->base
)->h_blocks
= cpu_to_le32(1);
853 header(s
->base
)->h_refcount
= cpu_to_le32(1);
854 s
->first
= ENTRY(header(s
->base
)+1);
855 s
->here
= ENTRY(header(s
->base
)+1);
856 s
->end
= s
->base
+ sb
->s_blocksize
;
859 error
= ext4_xattr_set_entry(i
, s
);
864 if (!IS_LAST_ENTRY(s
->first
))
865 ext4_xattr_rehash(header(s
->base
), s
->here
);
868 if (!IS_LAST_ENTRY(s
->first
)) {
869 new_bh
= ext4_xattr_cache_find(inode
, header(s
->base
), &ce
);
871 /* We found an identical block in the cache. */
872 if (new_bh
== bs
->bh
)
873 ea_bdebug(new_bh
, "keeping");
875 /* The old block is released after updating
877 error
= dquot_alloc_block(inode
,
878 EXT4_C2B(EXT4_SB(sb
), 1));
881 BUFFER_TRACE(new_bh
, "get_write_access");
882 error
= ext4_journal_get_write_access(handle
,
887 le32_add_cpu(&BHDR(new_bh
)->h_refcount
, 1);
888 ea_bdebug(new_bh
, "reusing; refcount now=%d",
889 le32_to_cpu(BHDR(new_bh
)->h_refcount
));
890 unlock_buffer(new_bh
);
891 error
= ext4_handle_dirty_xattr_block(handle
,
897 mb_cache_entry_release(ce
);
899 } else if (bs
->bh
&& s
->base
== bs
->bh
->b_data
) {
900 /* We were modifying this block in-place. */
901 ea_bdebug(bs
->bh
, "keeping this block");
905 /* We need to allocate a new block */
906 ext4_fsblk_t goal
, block
;
908 goal
= ext4_group_first_block_no(sb
,
909 EXT4_I(inode
)->i_block_group
);
911 /* non-extent files can't have physical blocks past 2^32 */
912 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)))
913 goal
= goal
& EXT4_MAX_BLOCK_FILE_PHYS
;
915 block
= ext4_new_meta_blocks(handle
, inode
, goal
, 0,
920 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)))
921 BUG_ON(block
> EXT4_MAX_BLOCK_FILE_PHYS
);
923 ea_idebug(inode
, "creating block %llu",
924 (unsigned long long)block
);
926 new_bh
= sb_getblk(sb
, block
);
927 if (unlikely(!new_bh
)) {
930 ext4_free_blocks(handle
, inode
, NULL
, block
, 1,
931 EXT4_FREE_BLOCKS_METADATA
);
935 error
= ext4_journal_get_create_access(handle
, new_bh
);
937 unlock_buffer(new_bh
);
941 memcpy(new_bh
->b_data
, s
->base
, new_bh
->b_size
);
942 set_buffer_uptodate(new_bh
);
943 unlock_buffer(new_bh
);
944 ext4_xattr_cache_insert(ext4_mb_cache
, new_bh
);
945 error
= ext4_handle_dirty_xattr_block(handle
,
952 /* Update the inode. */
953 EXT4_I(inode
)->i_file_acl
= new_bh
? new_bh
->b_blocknr
: 0;
955 /* Drop the previous xattr block. */
956 if (bs
->bh
&& bs
->bh
!= new_bh
)
957 ext4_xattr_release_block(handle
, inode
, bs
->bh
);
962 mb_cache_entry_release(ce
);
964 if (!(bs
->bh
&& s
->base
== bs
->bh
->b_data
))
970 dquot_free_block(inode
, EXT4_C2B(EXT4_SB(sb
), 1));
974 EXT4_ERROR_INODE(inode
, "bad block %llu",
975 EXT4_I(inode
)->i_file_acl
);
981 int ext4_xattr_ibody_find(struct inode
*inode
, struct ext4_xattr_info
*i
,
982 struct ext4_xattr_ibody_find
*is
)
984 struct ext4_xattr_ibody_header
*header
;
985 struct ext4_inode
*raw_inode
;
988 if (EXT4_I(inode
)->i_extra_isize
== 0)
990 raw_inode
= ext4_raw_inode(&is
->iloc
);
991 header
= IHDR(inode
, raw_inode
);
992 is
->s
.base
= is
->s
.first
= IFIRST(header
);
993 is
->s
.here
= is
->s
.first
;
994 is
->s
.end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
995 if (ext4_test_inode_state(inode
, EXT4_STATE_XATTR
)) {
996 error
= ext4_xattr_check_names(IFIRST(header
), is
->s
.end
,
1000 /* Find the named attribute. */
1001 error
= ext4_xattr_find_entry(&is
->s
.here
, i
->name_index
,
1002 i
->name
, is
->s
.end
-
1003 (void *)is
->s
.base
, 0);
1004 if (error
&& error
!= -ENODATA
)
1006 is
->s
.not_found
= error
;
1011 int ext4_xattr_ibody_inline_set(handle_t
*handle
, struct inode
*inode
,
1012 struct ext4_xattr_info
*i
,
1013 struct ext4_xattr_ibody_find
*is
)
1015 struct ext4_xattr_ibody_header
*header
;
1016 struct ext4_xattr_search
*s
= &is
->s
;
1019 if (EXT4_I(inode
)->i_extra_isize
== 0)
1021 error
= ext4_xattr_set_entry(i
, s
);
1023 if (error
== -ENOSPC
&&
1024 ext4_has_inline_data(inode
)) {
1025 error
= ext4_try_to_evict_inline_data(handle
, inode
,
1026 EXT4_XATTR_LEN(strlen(i
->name
) +
1027 EXT4_XATTR_SIZE(i
->value_len
)));
1030 error
= ext4_xattr_ibody_find(inode
, i
, is
);
1033 error
= ext4_xattr_set_entry(i
, s
);
1038 header
= IHDR(inode
, ext4_raw_inode(&is
->iloc
));
1039 if (!IS_LAST_ENTRY(s
->first
)) {
1040 header
->h_magic
= cpu_to_le32(EXT4_XATTR_MAGIC
);
1041 ext4_set_inode_state(inode
, EXT4_STATE_XATTR
);
1043 header
->h_magic
= cpu_to_le32(0);
1044 ext4_clear_inode_state(inode
, EXT4_STATE_XATTR
);
1049 static int ext4_xattr_ibody_set(handle_t
*handle
, struct inode
*inode
,
1050 struct ext4_xattr_info
*i
,
1051 struct ext4_xattr_ibody_find
*is
)
1053 struct ext4_xattr_ibody_header
*header
;
1054 struct ext4_xattr_search
*s
= &is
->s
;
1057 if (EXT4_I(inode
)->i_extra_isize
== 0)
1059 error
= ext4_xattr_set_entry(i
, s
);
1062 header
= IHDR(inode
, ext4_raw_inode(&is
->iloc
));
1063 if (!IS_LAST_ENTRY(s
->first
)) {
1064 header
->h_magic
= cpu_to_le32(EXT4_XATTR_MAGIC
);
1065 ext4_set_inode_state(inode
, EXT4_STATE_XATTR
);
1067 header
->h_magic
= cpu_to_le32(0);
1068 ext4_clear_inode_state(inode
, EXT4_STATE_XATTR
);
1074 * ext4_xattr_set_handle()
1076 * Create, replace or remove an extended attribute for this inode. Value
1077 * is NULL to remove an existing extended attribute, and non-NULL to
1078 * either replace an existing extended attribute, or create a new extended
1079 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
1080 * specify that an extended attribute must exist and must not exist
1081 * previous to the call, respectively.
1083 * Returns 0, or a negative error number on failure.
1086 ext4_xattr_set_handle(handle_t
*handle
, struct inode
*inode
, int name_index
,
1087 const char *name
, const void *value
, size_t value_len
,
1090 struct ext4_xattr_info i
= {
1091 .name_index
= name_index
,
1094 .value_len
= value_len
,
1097 struct ext4_xattr_ibody_find is
= {
1098 .s
= { .not_found
= -ENODATA
, },
1100 struct ext4_xattr_block_find bs
= {
1101 .s
= { .not_found
= -ENODATA
, },
1103 unsigned long no_expand
;
1108 if (strlen(name
) > 255)
1110 down_write(&EXT4_I(inode
)->xattr_sem
);
1111 no_expand
= ext4_test_inode_state(inode
, EXT4_STATE_NO_EXPAND
);
1112 ext4_set_inode_state(inode
, EXT4_STATE_NO_EXPAND
);
1114 error
= ext4_reserve_inode_write(handle
, inode
, &is
.iloc
);
1118 if (ext4_test_inode_state(inode
, EXT4_STATE_NEW
)) {
1119 struct ext4_inode
*raw_inode
= ext4_raw_inode(&is
.iloc
);
1120 memset(raw_inode
, 0, EXT4_SB(inode
->i_sb
)->s_inode_size
);
1121 ext4_clear_inode_state(inode
, EXT4_STATE_NEW
);
1124 error
= ext4_xattr_ibody_find(inode
, &i
, &is
);
1128 error
= ext4_xattr_block_find(inode
, &i
, &bs
);
1131 if (is
.s
.not_found
&& bs
.s
.not_found
) {
1133 if (flags
& XATTR_REPLACE
)
1140 if (flags
& XATTR_CREATE
)
1144 if (!is
.s
.not_found
)
1145 error
= ext4_xattr_ibody_set(handle
, inode
, &i
, &is
);
1146 else if (!bs
.s
.not_found
)
1147 error
= ext4_xattr_block_set(handle
, inode
, &i
, &bs
);
1149 error
= ext4_xattr_ibody_set(handle
, inode
, &i
, &is
);
1150 if (!error
&& !bs
.s
.not_found
) {
1152 error
= ext4_xattr_block_set(handle
, inode
, &i
, &bs
);
1153 } else if (error
== -ENOSPC
) {
1154 if (EXT4_I(inode
)->i_file_acl
&& !bs
.s
.base
) {
1155 error
= ext4_xattr_block_find(inode
, &i
, &bs
);
1159 error
= ext4_xattr_block_set(handle
, inode
, &i
, &bs
);
1162 if (!is
.s
.not_found
) {
1164 error
= ext4_xattr_ibody_set(handle
, inode
, &i
,
1170 ext4_xattr_update_super_block(handle
, inode
->i_sb
);
1171 inode
->i_ctime
= ext4_current_time(inode
);
1173 ext4_clear_inode_state(inode
, EXT4_STATE_NO_EXPAND
);
1174 error
= ext4_mark_iloc_dirty(handle
, inode
, &is
.iloc
);
1176 * The bh is consumed by ext4_mark_iloc_dirty, even with
1181 ext4_handle_sync(handle
);
1188 ext4_clear_inode_state(inode
, EXT4_STATE_NO_EXPAND
);
1189 up_write(&EXT4_I(inode
)->xattr_sem
);
1196 * Like ext4_xattr_set_handle, but start from an inode. This extended
1197 * attribute modification is a filesystem transaction by itself.
1199 * Returns 0, or a negative error number on failure.
1202 ext4_xattr_set(struct inode
*inode
, int name_index
, const char *name
,
1203 const void *value
, size_t value_len
, int flags
)
1206 int error
, retries
= 0;
1207 int credits
= ext4_jbd2_credits_xattr(inode
);
1210 handle
= ext4_journal_start(inode
, EXT4_HT_XATTR
, credits
);
1211 if (IS_ERR(handle
)) {
1212 error
= PTR_ERR(handle
);
1216 error
= ext4_xattr_set_handle(handle
, inode
, name_index
, name
,
1217 value
, value_len
, flags
);
1218 error2
= ext4_journal_stop(handle
);
1219 if (error
== -ENOSPC
&&
1220 ext4_should_retry_alloc(inode
->i_sb
, &retries
))
1230 * Shift the EA entries in the inode to create space for the increased
1233 static void ext4_xattr_shift_entries(struct ext4_xattr_entry
*entry
,
1234 int value_offs_shift
, void *to
,
1235 void *from
, size_t n
, int blocksize
)
1237 struct ext4_xattr_entry
*last
= entry
;
1240 /* Adjust the value offsets of the entries */
1241 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
1242 if (!last
->e_value_block
&& last
->e_value_size
) {
1243 new_offs
= le16_to_cpu(last
->e_value_offs
) +
1245 BUG_ON(new_offs
+ le32_to_cpu(last
->e_value_size
)
1247 last
->e_value_offs
= cpu_to_le16(new_offs
);
1250 /* Shift the entries by n bytes */
1251 memmove(to
, from
, n
);
1255 * Expand an inode by new_extra_isize bytes when EAs are present.
1256 * Returns 0 on success or negative error number on failure.
1258 int ext4_expand_extra_isize_ea(struct inode
*inode
, int new_extra_isize
,
1259 struct ext4_inode
*raw_inode
, handle_t
*handle
)
1261 struct ext4_xattr_ibody_header
*header
;
1262 struct ext4_xattr_entry
*entry
, *last
, *first
;
1263 struct buffer_head
*bh
= NULL
;
1264 struct ext4_xattr_ibody_find
*is
= NULL
;
1265 struct ext4_xattr_block_find
*bs
= NULL
;
1266 char *buffer
= NULL
, *b_entry_name
= NULL
;
1267 size_t min_offs
, free
;
1269 void *base
, *start
, *end
;
1270 int extra_isize
= 0, error
= 0, tried_min_extra_isize
= 0;
1271 int s_min_extra_isize
= le16_to_cpu(EXT4_SB(inode
->i_sb
)->s_es
->s_min_extra_isize
);
1273 down_write(&EXT4_I(inode
)->xattr_sem
);
1275 if (EXT4_I(inode
)->i_extra_isize
>= new_extra_isize
) {
1276 up_write(&EXT4_I(inode
)->xattr_sem
);
1280 header
= IHDR(inode
, raw_inode
);
1281 entry
= IFIRST(header
);
1284 * Check if enough free space is available in the inode to shift the
1285 * entries ahead by new_extra_isize.
1288 base
= start
= entry
;
1289 end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
1290 min_offs
= end
- base
;
1292 total_ino
= sizeof(struct ext4_xattr_ibody_header
);
1294 free
= ext4_xattr_free_space(last
, &min_offs
, base
, &total_ino
);
1295 if (free
>= new_extra_isize
) {
1296 entry
= IFIRST(header
);
1297 ext4_xattr_shift_entries(entry
, EXT4_I(inode
)->i_extra_isize
1298 - new_extra_isize
, (void *)raw_inode
+
1299 EXT4_GOOD_OLD_INODE_SIZE
+ new_extra_isize
,
1300 (void *)header
, total_ino
,
1301 inode
->i_sb
->s_blocksize
);
1302 EXT4_I(inode
)->i_extra_isize
= new_extra_isize
;
1308 * Enough free space isn't available in the inode, check if
1309 * EA block can hold new_extra_isize bytes.
1311 if (EXT4_I(inode
)->i_file_acl
) {
1312 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
1316 if (ext4_xattr_check_block(inode
, bh
)) {
1317 EXT4_ERROR_INODE(inode
, "bad block %llu",
1318 EXT4_I(inode
)->i_file_acl
);
1324 end
= bh
->b_data
+ bh
->b_size
;
1325 min_offs
= end
- base
;
1326 free
= ext4_xattr_free_space(first
, &min_offs
, base
, NULL
);
1327 if (free
< new_extra_isize
) {
1328 if (!tried_min_extra_isize
&& s_min_extra_isize
) {
1329 tried_min_extra_isize
++;
1330 new_extra_isize
= s_min_extra_isize
;
1338 free
= inode
->i_sb
->s_blocksize
;
1341 while (new_extra_isize
> 0) {
1342 size_t offs
, size
, entry_size
;
1343 struct ext4_xattr_entry
*small_entry
= NULL
;
1344 struct ext4_xattr_info i
= {
1348 unsigned int total_size
; /* EA entry size + value size */
1349 unsigned int shift_bytes
; /* No. of bytes to shift EAs by? */
1350 unsigned int min_total_size
= ~0U;
1352 is
= kzalloc(sizeof(struct ext4_xattr_ibody_find
), GFP_NOFS
);
1353 bs
= kzalloc(sizeof(struct ext4_xattr_block_find
), GFP_NOFS
);
1359 is
->s
.not_found
= -ENODATA
;
1360 bs
->s
.not_found
= -ENODATA
;
1364 last
= IFIRST(header
);
1365 /* Find the entry best suited to be pushed into EA block */
1367 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
1369 EXT4_XATTR_SIZE(le32_to_cpu(last
->e_value_size
)) +
1370 EXT4_XATTR_LEN(last
->e_name_len
);
1371 if (total_size
<= free
&& total_size
< min_total_size
) {
1372 if (total_size
< new_extra_isize
) {
1376 min_total_size
= total_size
;
1381 if (entry
== NULL
) {
1383 entry
= small_entry
;
1385 if (!tried_min_extra_isize
&&
1386 s_min_extra_isize
) {
1387 tried_min_extra_isize
++;
1388 new_extra_isize
= s_min_extra_isize
;
1389 kfree(is
); is
= NULL
;
1390 kfree(bs
); bs
= NULL
;
1398 offs
= le16_to_cpu(entry
->e_value_offs
);
1399 size
= le32_to_cpu(entry
->e_value_size
);
1400 entry_size
= EXT4_XATTR_LEN(entry
->e_name_len
);
1401 i
.name_index
= entry
->e_name_index
,
1402 buffer
= kmalloc(EXT4_XATTR_SIZE(size
), GFP_NOFS
);
1403 b_entry_name
= kmalloc(entry
->e_name_len
+ 1, GFP_NOFS
);
1404 if (!buffer
|| !b_entry_name
) {
1408 /* Save the entry name and the entry value */
1409 memcpy(buffer
, (void *)IFIRST(header
) + offs
,
1410 EXT4_XATTR_SIZE(size
));
1411 memcpy(b_entry_name
, entry
->e_name
, entry
->e_name_len
);
1412 b_entry_name
[entry
->e_name_len
] = '\0';
1413 i
.name
= b_entry_name
;
1415 error
= ext4_get_inode_loc(inode
, &is
->iloc
);
1419 error
= ext4_xattr_ibody_find(inode
, &i
, is
);
1423 /* Remove the chosen entry from the inode */
1424 error
= ext4_xattr_ibody_set(handle
, inode
, &i
, is
);
1428 entry
= IFIRST(header
);
1429 if (entry_size
+ EXT4_XATTR_SIZE(size
) >= new_extra_isize
)
1430 shift_bytes
= new_extra_isize
;
1432 shift_bytes
= entry_size
+ size
;
1433 /* Adjust the offsets and shift the remaining entries ahead */
1434 ext4_xattr_shift_entries(entry
, EXT4_I(inode
)->i_extra_isize
-
1435 shift_bytes
, (void *)raw_inode
+
1436 EXT4_GOOD_OLD_INODE_SIZE
+ extra_isize
+ shift_bytes
,
1437 (void *)header
, total_ino
- entry_size
,
1438 inode
->i_sb
->s_blocksize
);
1440 extra_isize
+= shift_bytes
;
1441 new_extra_isize
-= shift_bytes
;
1442 EXT4_I(inode
)->i_extra_isize
= extra_isize
;
1444 i
.name
= b_entry_name
;
1447 error
= ext4_xattr_block_find(inode
, &i
, bs
);
1451 /* Add entry which was removed from the inode into the block */
1452 error
= ext4_xattr_block_set(handle
, inode
, &i
, bs
);
1455 kfree(b_entry_name
);
1457 b_entry_name
= NULL
;
1459 brelse(is
->iloc
.bh
);
1464 up_write(&EXT4_I(inode
)->xattr_sem
);
1468 kfree(b_entry_name
);
1471 brelse(is
->iloc
.bh
);
1475 up_write(&EXT4_I(inode
)->xattr_sem
);
1482 * ext4_xattr_delete_inode()
1484 * Free extended attribute resources associated with this inode. This
1485 * is called immediately before an inode is freed. We have exclusive
1486 * access to the inode.
1489 ext4_xattr_delete_inode(handle_t
*handle
, struct inode
*inode
)
1491 struct buffer_head
*bh
= NULL
;
1493 if (!EXT4_I(inode
)->i_file_acl
)
1495 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
1497 EXT4_ERROR_INODE(inode
, "block %llu read error",
1498 EXT4_I(inode
)->i_file_acl
);
1501 if (BHDR(bh
)->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
) ||
1502 BHDR(bh
)->h_blocks
!= cpu_to_le32(1)) {
1503 EXT4_ERROR_INODE(inode
, "bad block %llu",
1504 EXT4_I(inode
)->i_file_acl
);
1507 ext4_xattr_release_block(handle
, inode
, bh
);
1508 EXT4_I(inode
)->i_file_acl
= 0;
1515 * ext4_xattr_put_super()
1517 * This is called when a file system is unmounted.
1520 ext4_xattr_put_super(struct super_block
*sb
)
1522 mb_cache_shrink(sb
->s_bdev
);
1526 * ext4_xattr_cache_insert()
1528 * Create a new entry in the extended attribute cache, and insert
1529 * it unless such an entry is already in the cache.
1531 * Returns 0, or a negative error number on failure.
1534 ext4_xattr_cache_insert(struct mb_cache
*ext4_mb_cache
, struct buffer_head
*bh
)
1536 __u32 hash
= le32_to_cpu(BHDR(bh
)->h_hash
);
1537 struct mb_cache_entry
*ce
;
1540 ce
= mb_cache_entry_alloc(ext4_mb_cache
, GFP_NOFS
);
1542 ea_bdebug(bh
, "out of memory");
1545 error
= mb_cache_entry_insert(ce
, bh
->b_bdev
, bh
->b_blocknr
, hash
);
1547 mb_cache_entry_free(ce
);
1548 if (error
== -EBUSY
) {
1549 ea_bdebug(bh
, "already in cache");
1553 ea_bdebug(bh
, "inserting [%x]", (int)hash
);
1554 mb_cache_entry_release(ce
);
1561 * Compare two extended attribute blocks for equality.
1563 * Returns 0 if the blocks are equal, 1 if they differ, and
1564 * a negative error number on errors.
1567 ext4_xattr_cmp(struct ext4_xattr_header
*header1
,
1568 struct ext4_xattr_header
*header2
)
1570 struct ext4_xattr_entry
*entry1
, *entry2
;
1572 entry1
= ENTRY(header1
+1);
1573 entry2
= ENTRY(header2
+1);
1574 while (!IS_LAST_ENTRY(entry1
)) {
1575 if (IS_LAST_ENTRY(entry2
))
1577 if (entry1
->e_hash
!= entry2
->e_hash
||
1578 entry1
->e_name_index
!= entry2
->e_name_index
||
1579 entry1
->e_name_len
!= entry2
->e_name_len
||
1580 entry1
->e_value_size
!= entry2
->e_value_size
||
1581 memcmp(entry1
->e_name
, entry2
->e_name
, entry1
->e_name_len
))
1583 if (entry1
->e_value_block
!= 0 || entry2
->e_value_block
!= 0)
1585 if (memcmp((char *)header1
+ le16_to_cpu(entry1
->e_value_offs
),
1586 (char *)header2
+ le16_to_cpu(entry2
->e_value_offs
),
1587 le32_to_cpu(entry1
->e_value_size
)))
1590 entry1
= EXT4_XATTR_NEXT(entry1
);
1591 entry2
= EXT4_XATTR_NEXT(entry2
);
1593 if (!IS_LAST_ENTRY(entry2
))
1599 * ext4_xattr_cache_find()
1601 * Find an identical extended attribute block.
1603 * Returns a pointer to the block found, or NULL if such a block was
1604 * not found or an error occurred.
1606 static struct buffer_head
*
1607 ext4_xattr_cache_find(struct inode
*inode
, struct ext4_xattr_header
*header
,
1608 struct mb_cache_entry
**pce
)
1610 __u32 hash
= le32_to_cpu(header
->h_hash
);
1611 struct mb_cache_entry
*ce
;
1612 struct mb_cache
*ext4_mb_cache
= EXT4_GET_MB_CACHE(inode
);
1614 if (!header
->h_hash
)
1615 return NULL
; /* never share */
1616 ea_idebug(inode
, "looking for cached blocks [%x]", (int)hash
);
1618 ce
= mb_cache_entry_find_first(ext4_mb_cache
, inode
->i_sb
->s_bdev
,
1621 struct buffer_head
*bh
;
1624 if (PTR_ERR(ce
) == -EAGAIN
)
1628 bh
= sb_bread(inode
->i_sb
, ce
->e_block
);
1630 EXT4_ERROR_INODE(inode
, "block %lu read error",
1631 (unsigned long) ce
->e_block
);
1632 } else if (le32_to_cpu(BHDR(bh
)->h_refcount
) >=
1633 EXT4_XATTR_REFCOUNT_MAX
) {
1634 ea_idebug(inode
, "block %lu refcount %d>=%d",
1635 (unsigned long) ce
->e_block
,
1636 le32_to_cpu(BHDR(bh
)->h_refcount
),
1637 EXT4_XATTR_REFCOUNT_MAX
);
1638 } else if (ext4_xattr_cmp(header
, BHDR(bh
)) == 0) {
1643 ce
= mb_cache_entry_find_next(ce
, inode
->i_sb
->s_bdev
, hash
);
1648 #define NAME_HASH_SHIFT 5
1649 #define VALUE_HASH_SHIFT 16
1652 * ext4_xattr_hash_entry()
1654 * Compute the hash of an extended attribute.
1656 static inline void ext4_xattr_hash_entry(struct ext4_xattr_header
*header
,
1657 struct ext4_xattr_entry
*entry
)
1660 char *name
= entry
->e_name
;
1663 for (n
= 0; n
< entry
->e_name_len
; n
++) {
1664 hash
= (hash
<< NAME_HASH_SHIFT
) ^
1665 (hash
>> (8*sizeof(hash
) - NAME_HASH_SHIFT
)) ^
1669 if (entry
->e_value_block
== 0 && entry
->e_value_size
!= 0) {
1670 __le32
*value
= (__le32
*)((char *)header
+
1671 le16_to_cpu(entry
->e_value_offs
));
1672 for (n
= (le32_to_cpu(entry
->e_value_size
) +
1673 EXT4_XATTR_ROUND
) >> EXT4_XATTR_PAD_BITS
; n
; n
--) {
1674 hash
= (hash
<< VALUE_HASH_SHIFT
) ^
1675 (hash
>> (8*sizeof(hash
) - VALUE_HASH_SHIFT
)) ^
1676 le32_to_cpu(*value
++);
1679 entry
->e_hash
= cpu_to_le32(hash
);
1682 #undef NAME_HASH_SHIFT
1683 #undef VALUE_HASH_SHIFT
1685 #define BLOCK_HASH_SHIFT 16
1688 * ext4_xattr_rehash()
1690 * Re-compute the extended attribute hash value after an entry has changed.
1692 static void ext4_xattr_rehash(struct ext4_xattr_header
*header
,
1693 struct ext4_xattr_entry
*entry
)
1695 struct ext4_xattr_entry
*here
;
1698 ext4_xattr_hash_entry(header
, entry
);
1699 here
= ENTRY(header
+1);
1700 while (!IS_LAST_ENTRY(here
)) {
1701 if (!here
->e_hash
) {
1702 /* Block is not shared if an entry's hash value == 0 */
1706 hash
= (hash
<< BLOCK_HASH_SHIFT
) ^
1707 (hash
>> (8*sizeof(hash
) - BLOCK_HASH_SHIFT
)) ^
1708 le32_to_cpu(here
->e_hash
);
1709 here
= EXT4_XATTR_NEXT(here
);
1711 header
->h_hash
= cpu_to_le32(hash
);
1714 #undef BLOCK_HASH_SHIFT
1716 #define HASH_BUCKET_BITS 10
1719 ext4_xattr_create_cache(char *name
)
1721 return mb_cache_create(name
, HASH_BUCKET_BITS
);
1724 void ext4_xattr_destroy_cache(struct mb_cache
*cache
)
1727 mb_cache_destroy(cache
);