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 "ext4_jbd2.h"
63 #ifdef EXT4_XATTR_DEBUG
64 # define ea_idebug(inode, f...) do { \
65 printk(KERN_DEBUG "inode %s:%lu: ", \
66 inode->i_sb->s_id, inode->i_ino); \
70 # define ea_bdebug(bh, f...) do { \
71 printk(KERN_DEBUG "block %pg:%lu: ", \
72 bh->b_bdev, (unsigned long) bh->b_blocknr); \
77 # define ea_idebug(inode, fmt, ...) no_printk(fmt, ##__VA_ARGS__)
78 # define ea_bdebug(bh, fmt, ...) no_printk(fmt, ##__VA_ARGS__)
81 static void ext4_xattr_cache_insert(struct mb_cache
*, struct buffer_head
*);
82 static struct buffer_head
*ext4_xattr_cache_find(struct inode
*,
83 struct ext4_xattr_header
*,
84 struct mb_cache_entry
**);
85 static void ext4_xattr_rehash(struct ext4_xattr_header
*,
86 struct ext4_xattr_entry
*);
87 static int ext4_xattr_list(struct dentry
*dentry
, char *buffer
,
90 static const struct xattr_handler
*ext4_xattr_handler_map
[] = {
91 [EXT4_XATTR_INDEX_USER
] = &ext4_xattr_user_handler
,
92 #ifdef CONFIG_EXT4_FS_POSIX_ACL
93 [EXT4_XATTR_INDEX_POSIX_ACL_ACCESS
] = &posix_acl_access_xattr_handler
,
94 [EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT
] = &posix_acl_default_xattr_handler
,
96 [EXT4_XATTR_INDEX_TRUSTED
] = &ext4_xattr_trusted_handler
,
97 #ifdef CONFIG_EXT4_FS_SECURITY
98 [EXT4_XATTR_INDEX_SECURITY
] = &ext4_xattr_security_handler
,
102 const struct xattr_handler
*ext4_xattr_handlers
[] = {
103 &ext4_xattr_user_handler
,
104 &ext4_xattr_trusted_handler
,
105 #ifdef CONFIG_EXT4_FS_POSIX_ACL
106 &posix_acl_access_xattr_handler
,
107 &posix_acl_default_xattr_handler
,
109 #ifdef CONFIG_EXT4_FS_SECURITY
110 &ext4_xattr_security_handler
,
115 #define EXT4_GET_MB_CACHE(inode) (((struct ext4_sb_info *) \
116 inode->i_sb->s_fs_info)->s_mb_cache)
118 static __le32
ext4_xattr_block_csum(struct inode
*inode
,
120 struct ext4_xattr_header
*hdr
)
122 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
125 __le64 dsk_block_nr
= cpu_to_le64(block_nr
);
127 save_csum
= hdr
->h_checksum
;
129 csum
= ext4_chksum(sbi
, sbi
->s_csum_seed
, (__u8
*)&dsk_block_nr
,
130 sizeof(dsk_block_nr
));
131 csum
= ext4_chksum(sbi
, csum
, (__u8
*)hdr
,
132 EXT4_BLOCK_SIZE(inode
->i_sb
));
134 hdr
->h_checksum
= save_csum
;
135 return cpu_to_le32(csum
);
138 static int ext4_xattr_block_csum_verify(struct inode
*inode
,
140 struct ext4_xattr_header
*hdr
)
142 if (ext4_has_metadata_csum(inode
->i_sb
) &&
143 (hdr
->h_checksum
!= ext4_xattr_block_csum(inode
, block_nr
, hdr
)))
148 static void ext4_xattr_block_csum_set(struct inode
*inode
,
150 struct ext4_xattr_header
*hdr
)
152 if (!ext4_has_metadata_csum(inode
->i_sb
))
155 hdr
->h_checksum
= ext4_xattr_block_csum(inode
, block_nr
, hdr
);
158 static inline int ext4_handle_dirty_xattr_block(handle_t
*handle
,
160 struct buffer_head
*bh
)
162 ext4_xattr_block_csum_set(inode
, bh
->b_blocknr
, BHDR(bh
));
163 return ext4_handle_dirty_metadata(handle
, inode
, bh
);
166 static inline const struct xattr_handler
*
167 ext4_xattr_handler(int name_index
)
169 const struct xattr_handler
*handler
= NULL
;
171 if (name_index
> 0 && name_index
< ARRAY_SIZE(ext4_xattr_handler_map
))
172 handler
= ext4_xattr_handler_map
[name_index
];
177 * Inode operation listxattr()
179 * d_inode(dentry)->i_mutex: don't care
182 ext4_listxattr(struct dentry
*dentry
, char *buffer
, size_t size
)
184 return ext4_xattr_list(dentry
, buffer
, size
);
188 ext4_xattr_check_names(struct ext4_xattr_entry
*entry
, void *end
,
191 struct ext4_xattr_entry
*e
= entry
;
193 while (!IS_LAST_ENTRY(e
)) {
194 struct ext4_xattr_entry
*next
= EXT4_XATTR_NEXT(e
);
195 if ((void *)next
>= end
)
196 return -EFSCORRUPTED
;
200 while (!IS_LAST_ENTRY(entry
)) {
201 if (entry
->e_value_size
!= 0 &&
202 (value_start
+ le16_to_cpu(entry
->e_value_offs
) <
203 (void *)e
+ sizeof(__u32
) ||
204 value_start
+ le16_to_cpu(entry
->e_value_offs
) +
205 le32_to_cpu(entry
->e_value_size
) > end
))
206 return -EFSCORRUPTED
;
207 entry
= EXT4_XATTR_NEXT(entry
);
214 ext4_xattr_check_block(struct inode
*inode
, struct buffer_head
*bh
)
218 if (buffer_verified(bh
))
221 if (BHDR(bh
)->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
) ||
222 BHDR(bh
)->h_blocks
!= cpu_to_le32(1))
223 return -EFSCORRUPTED
;
224 if (!ext4_xattr_block_csum_verify(inode
, bh
->b_blocknr
, BHDR(bh
)))
226 error
= ext4_xattr_check_names(BFIRST(bh
), bh
->b_data
+ bh
->b_size
,
229 set_buffer_verified(bh
);
234 ext4_xattr_check_entry(struct ext4_xattr_entry
*entry
, size_t size
)
236 size_t value_size
= le32_to_cpu(entry
->e_value_size
);
238 if (entry
->e_value_block
!= 0 || value_size
> size
||
239 le16_to_cpu(entry
->e_value_offs
) + value_size
> size
)
240 return -EFSCORRUPTED
;
245 ext4_xattr_find_entry(struct ext4_xattr_entry
**pentry
, int name_index
,
246 const char *name
, size_t size
, int sorted
)
248 struct ext4_xattr_entry
*entry
;
254 name_len
= strlen(name
);
256 for (; !IS_LAST_ENTRY(entry
); entry
= EXT4_XATTR_NEXT(entry
)) {
257 cmp
= name_index
- entry
->e_name_index
;
259 cmp
= name_len
- entry
->e_name_len
;
261 cmp
= memcmp(name
, entry
->e_name
, name_len
);
262 if (cmp
<= 0 && (sorted
|| cmp
== 0))
266 if (!cmp
&& ext4_xattr_check_entry(entry
, size
))
267 return -EFSCORRUPTED
;
268 return cmp
? -ENODATA
: 0;
272 ext4_xattr_block_get(struct inode
*inode
, int name_index
, const char *name
,
273 void *buffer
, size_t buffer_size
)
275 struct buffer_head
*bh
= NULL
;
276 struct ext4_xattr_entry
*entry
;
279 struct mb_cache
*ext4_mb_cache
= EXT4_GET_MB_CACHE(inode
);
281 ea_idebug(inode
, "name=%d.%s, buffer=%p, buffer_size=%ld",
282 name_index
, name
, buffer
, (long)buffer_size
);
285 if (!EXT4_I(inode
)->i_file_acl
)
287 ea_idebug(inode
, "reading block %llu",
288 (unsigned long long)EXT4_I(inode
)->i_file_acl
);
289 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
292 ea_bdebug(bh
, "b_count=%d, refcount=%d",
293 atomic_read(&(bh
->b_count
)), le32_to_cpu(BHDR(bh
)->h_refcount
));
294 if (ext4_xattr_check_block(inode
, bh
)) {
296 EXT4_ERROR_INODE(inode
, "bad block %llu",
297 EXT4_I(inode
)->i_file_acl
);
298 error
= -EFSCORRUPTED
;
301 ext4_xattr_cache_insert(ext4_mb_cache
, bh
);
303 error
= ext4_xattr_find_entry(&entry
, name_index
, name
, bh
->b_size
, 1);
304 if (error
== -EFSCORRUPTED
)
308 size
= le32_to_cpu(entry
->e_value_size
);
311 if (size
> buffer_size
)
313 memcpy(buffer
, bh
->b_data
+ le16_to_cpu(entry
->e_value_offs
),
324 ext4_xattr_ibody_get(struct inode
*inode
, int name_index
, const char *name
,
325 void *buffer
, size_t buffer_size
)
327 struct ext4_xattr_ibody_header
*header
;
328 struct ext4_xattr_entry
*entry
;
329 struct ext4_inode
*raw_inode
;
330 struct ext4_iloc iloc
;
335 if (!ext4_test_inode_state(inode
, EXT4_STATE_XATTR
))
337 error
= ext4_get_inode_loc(inode
, &iloc
);
340 raw_inode
= ext4_raw_inode(&iloc
);
341 header
= IHDR(inode
, raw_inode
);
342 entry
= IFIRST(header
);
343 end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
344 error
= ext4_xattr_check_names(entry
, end
, entry
);
347 error
= ext4_xattr_find_entry(&entry
, name_index
, name
,
348 end
- (void *)entry
, 0);
351 size
= le32_to_cpu(entry
->e_value_size
);
354 if (size
> buffer_size
)
356 memcpy(buffer
, (void *)IFIRST(header
) +
357 le16_to_cpu(entry
->e_value_offs
), size
);
369 * Copy an extended attribute into the buffer
370 * provided, or compute the buffer size required.
371 * Buffer is NULL to compute the size of the buffer required.
373 * Returns a negative error number on failure, or the number of bytes
374 * used / required on success.
377 ext4_xattr_get(struct inode
*inode
, int name_index
, const char *name
,
378 void *buffer
, size_t buffer_size
)
382 if (strlen(name
) > 255)
385 down_read(&EXT4_I(inode
)->xattr_sem
);
386 error
= ext4_xattr_ibody_get(inode
, name_index
, name
, buffer
,
388 if (error
== -ENODATA
)
389 error
= ext4_xattr_block_get(inode
, name_index
, name
, buffer
,
391 up_read(&EXT4_I(inode
)->xattr_sem
);
396 ext4_xattr_list_entries(struct dentry
*dentry
, struct ext4_xattr_entry
*entry
,
397 char *buffer
, size_t buffer_size
)
399 size_t rest
= buffer_size
;
401 for (; !IS_LAST_ENTRY(entry
); entry
= EXT4_XATTR_NEXT(entry
)) {
402 const struct xattr_handler
*handler
=
403 ext4_xattr_handler(entry
->e_name_index
);
405 if (handler
&& (!handler
->list
|| handler
->list(dentry
))) {
406 const char *prefix
= handler
->prefix
?: handler
->name
;
407 size_t prefix_len
= strlen(prefix
);
408 size_t size
= prefix_len
+ entry
->e_name_len
+ 1;
413 memcpy(buffer
, prefix
, prefix_len
);
414 buffer
+= prefix_len
;
415 memcpy(buffer
, entry
->e_name
, entry
->e_name_len
);
416 buffer
+= entry
->e_name_len
;
422 return buffer_size
- rest
; /* total size */
426 ext4_xattr_block_list(struct dentry
*dentry
, char *buffer
, size_t buffer_size
)
428 struct inode
*inode
= d_inode(dentry
);
429 struct buffer_head
*bh
= NULL
;
431 struct mb_cache
*ext4_mb_cache
= EXT4_GET_MB_CACHE(inode
);
433 ea_idebug(inode
, "buffer=%p, buffer_size=%ld",
434 buffer
, (long)buffer_size
);
437 if (!EXT4_I(inode
)->i_file_acl
)
439 ea_idebug(inode
, "reading block %llu",
440 (unsigned long long)EXT4_I(inode
)->i_file_acl
);
441 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
445 ea_bdebug(bh
, "b_count=%d, refcount=%d",
446 atomic_read(&(bh
->b_count
)), le32_to_cpu(BHDR(bh
)->h_refcount
));
447 if (ext4_xattr_check_block(inode
, bh
)) {
448 EXT4_ERROR_INODE(inode
, "bad block %llu",
449 EXT4_I(inode
)->i_file_acl
);
450 error
= -EFSCORRUPTED
;
453 ext4_xattr_cache_insert(ext4_mb_cache
, bh
);
454 error
= ext4_xattr_list_entries(dentry
, BFIRST(bh
), buffer
, buffer_size
);
463 ext4_xattr_ibody_list(struct dentry
*dentry
, char *buffer
, size_t buffer_size
)
465 struct inode
*inode
= d_inode(dentry
);
466 struct ext4_xattr_ibody_header
*header
;
467 struct ext4_inode
*raw_inode
;
468 struct ext4_iloc iloc
;
472 if (!ext4_test_inode_state(inode
, EXT4_STATE_XATTR
))
474 error
= ext4_get_inode_loc(inode
, &iloc
);
477 raw_inode
= ext4_raw_inode(&iloc
);
478 header
= IHDR(inode
, raw_inode
);
479 end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
480 error
= ext4_xattr_check_names(IFIRST(header
), end
, IFIRST(header
));
483 error
= ext4_xattr_list_entries(dentry
, IFIRST(header
),
484 buffer
, buffer_size
);
494 * Copy a list of attribute names into the buffer
495 * provided, or compute the buffer size required.
496 * Buffer is NULL to compute the size of the buffer required.
498 * Returns a negative error number on failure, or the number of bytes
499 * used / required on success.
502 ext4_xattr_list(struct dentry
*dentry
, char *buffer
, size_t buffer_size
)
506 down_read(&EXT4_I(d_inode(dentry
))->xattr_sem
);
507 ret
= ret2
= ext4_xattr_ibody_list(dentry
, buffer
, buffer_size
);
514 ret
= ext4_xattr_block_list(dentry
, buffer
, buffer_size
);
519 up_read(&EXT4_I(d_inode(dentry
))->xattr_sem
);
524 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is
527 static void ext4_xattr_update_super_block(handle_t
*handle
,
528 struct super_block
*sb
)
530 if (ext4_has_feature_xattr(sb
))
533 BUFFER_TRACE(EXT4_SB(sb
)->s_sbh
, "get_write_access");
534 if (ext4_journal_get_write_access(handle
, EXT4_SB(sb
)->s_sbh
) == 0) {
535 ext4_set_feature_xattr(sb
);
536 ext4_handle_dirty_super(handle
, sb
);
541 * Release the xattr block BH: If the reference count is > 1, decrement it;
542 * otherwise free the block.
545 ext4_xattr_release_block(handle_t
*handle
, struct inode
*inode
,
546 struct buffer_head
*bh
)
548 struct mb_cache
*ext4_mb_cache
= EXT4_GET_MB_CACHE(inode
);
552 BUFFER_TRACE(bh
, "get_write_access");
553 error
= ext4_journal_get_write_access(handle
, bh
);
558 hash
= le32_to_cpu(BHDR(bh
)->h_hash
);
559 ref
= le32_to_cpu(BHDR(bh
)->h_refcount
);
561 ea_bdebug(bh
, "refcount now=0; freeing");
563 * This must happen under buffer lock for
564 * ext4_xattr_block_set() to reliably detect freed block
566 mb_cache_entry_delete_block(ext4_mb_cache
, hash
, bh
->b_blocknr
);
569 ext4_free_blocks(handle
, inode
, bh
, 0, 1,
570 EXT4_FREE_BLOCKS_METADATA
|
571 EXT4_FREE_BLOCKS_FORGET
);
574 BHDR(bh
)->h_refcount
= cpu_to_le32(ref
);
575 if (ref
== EXT4_XATTR_REFCOUNT_MAX
- 1) {
576 struct mb_cache_entry
*ce
;
578 ce
= mb_cache_entry_get(ext4_mb_cache
, hash
,
582 mb_cache_entry_put(ext4_mb_cache
, ce
);
587 * Beware of this ugliness: Releasing of xattr block references
588 * from different inodes can race and so we have to protect
589 * from a race where someone else frees the block (and releases
590 * its journal_head) before we are done dirtying the buffer. In
591 * nojournal mode this race is harmless and we actually cannot
592 * call ext4_handle_dirty_xattr_block() with locked buffer as
593 * that function can call sync_dirty_buffer() so for that case
594 * we handle the dirtying after unlocking the buffer.
596 if (ext4_handle_valid(handle
))
597 error
= ext4_handle_dirty_xattr_block(handle
, inode
,
600 if (!ext4_handle_valid(handle
))
601 error
= ext4_handle_dirty_xattr_block(handle
, inode
,
604 ext4_handle_sync(handle
);
605 dquot_free_block(inode
, EXT4_C2B(EXT4_SB(inode
->i_sb
), 1));
606 ea_bdebug(bh
, "refcount now=%d; releasing",
607 le32_to_cpu(BHDR(bh
)->h_refcount
));
610 ext4_std_error(inode
->i_sb
, error
);
615 * Find the available free space for EAs. This also returns the total number of
616 * bytes used by EA entries.
618 static size_t ext4_xattr_free_space(struct ext4_xattr_entry
*last
,
619 size_t *min_offs
, void *base
, int *total
)
621 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
622 if (!last
->e_value_block
&& last
->e_value_size
) {
623 size_t offs
= le16_to_cpu(last
->e_value_offs
);
624 if (offs
< *min_offs
)
628 *total
+= EXT4_XATTR_LEN(last
->e_name_len
);
630 return (*min_offs
- ((void *)last
- base
) - sizeof(__u32
));
634 ext4_xattr_set_entry(struct ext4_xattr_info
*i
, struct ext4_xattr_search
*s
)
636 struct ext4_xattr_entry
*last
;
637 size_t free
, min_offs
= s
->end
- s
->base
, name_len
= strlen(i
->name
);
639 /* Compute min_offs and last. */
641 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
642 if (!last
->e_value_block
&& last
->e_value_size
) {
643 size_t offs
= le16_to_cpu(last
->e_value_offs
);
648 free
= min_offs
- ((void *)last
- s
->base
) - sizeof(__u32
);
650 if (!s
->here
->e_value_block
&& s
->here
->e_value_size
) {
651 size_t size
= le32_to_cpu(s
->here
->e_value_size
);
652 free
+= EXT4_XATTR_SIZE(size
);
654 free
+= EXT4_XATTR_LEN(name_len
);
657 if (free
< EXT4_XATTR_LEN(name_len
) +
658 EXT4_XATTR_SIZE(i
->value_len
))
662 if (i
->value
&& s
->not_found
) {
663 /* Insert the new name. */
664 size_t size
= EXT4_XATTR_LEN(name_len
);
665 size_t rest
= (void *)last
- (void *)s
->here
+ sizeof(__u32
);
666 memmove((void *)s
->here
+ size
, s
->here
, rest
);
667 memset(s
->here
, 0, size
);
668 s
->here
->e_name_index
= i
->name_index
;
669 s
->here
->e_name_len
= name_len
;
670 memcpy(s
->here
->e_name
, i
->name
, name_len
);
672 if (!s
->here
->e_value_block
&& s
->here
->e_value_size
) {
673 void *first_val
= s
->base
+ min_offs
;
674 size_t offs
= le16_to_cpu(s
->here
->e_value_offs
);
675 void *val
= s
->base
+ offs
;
676 size_t size
= EXT4_XATTR_SIZE(
677 le32_to_cpu(s
->here
->e_value_size
));
679 if (i
->value
&& size
== EXT4_XATTR_SIZE(i
->value_len
)) {
680 /* The old and the new value have the same
681 size. Just replace. */
682 s
->here
->e_value_size
=
683 cpu_to_le32(i
->value_len
);
684 if (i
->value
== EXT4_ZERO_XATTR_VALUE
) {
685 memset(val
, 0, size
);
687 /* Clear pad bytes first. */
688 memset(val
+ size
- EXT4_XATTR_PAD
, 0,
690 memcpy(val
, i
->value
, i
->value_len
);
695 /* Remove the old value. */
696 memmove(first_val
+ size
, first_val
, val
- first_val
);
697 memset(first_val
, 0, size
);
698 s
->here
->e_value_size
= 0;
699 s
->here
->e_value_offs
= 0;
702 /* Adjust all value offsets. */
704 while (!IS_LAST_ENTRY(last
)) {
705 size_t o
= le16_to_cpu(last
->e_value_offs
);
706 if (!last
->e_value_block
&&
707 last
->e_value_size
&& o
< offs
)
709 cpu_to_le16(o
+ size
);
710 last
= EXT4_XATTR_NEXT(last
);
714 /* Remove the old name. */
715 size_t size
= EXT4_XATTR_LEN(name_len
);
716 last
= ENTRY((void *)last
- size
);
717 memmove(s
->here
, (void *)s
->here
+ size
,
718 (void *)last
- (void *)s
->here
+ sizeof(__u32
));
719 memset(last
, 0, size
);
724 /* Insert the new value. */
725 s
->here
->e_value_size
= cpu_to_le32(i
->value_len
);
727 size_t size
= EXT4_XATTR_SIZE(i
->value_len
);
728 void *val
= s
->base
+ min_offs
- size
;
729 s
->here
->e_value_offs
= cpu_to_le16(min_offs
- size
);
730 if (i
->value
== EXT4_ZERO_XATTR_VALUE
) {
731 memset(val
, 0, size
);
733 /* Clear the pad bytes first. */
734 memset(val
+ size
- EXT4_XATTR_PAD
, 0,
736 memcpy(val
, i
->value
, i
->value_len
);
743 struct ext4_xattr_block_find
{
744 struct ext4_xattr_search s
;
745 struct buffer_head
*bh
;
749 ext4_xattr_block_find(struct inode
*inode
, struct ext4_xattr_info
*i
,
750 struct ext4_xattr_block_find
*bs
)
752 struct super_block
*sb
= inode
->i_sb
;
755 ea_idebug(inode
, "name=%d.%s, value=%p, value_len=%ld",
756 i
->name_index
, i
->name
, i
->value
, (long)i
->value_len
);
758 if (EXT4_I(inode
)->i_file_acl
) {
759 /* The inode already has an extended attribute block. */
760 bs
->bh
= sb_bread(sb
, EXT4_I(inode
)->i_file_acl
);
764 ea_bdebug(bs
->bh
, "b_count=%d, refcount=%d",
765 atomic_read(&(bs
->bh
->b_count
)),
766 le32_to_cpu(BHDR(bs
->bh
)->h_refcount
));
767 if (ext4_xattr_check_block(inode
, bs
->bh
)) {
768 EXT4_ERROR_INODE(inode
, "bad block %llu",
769 EXT4_I(inode
)->i_file_acl
);
770 error
= -EFSCORRUPTED
;
773 /* Find the named attribute. */
774 bs
->s
.base
= BHDR(bs
->bh
);
775 bs
->s
.first
= BFIRST(bs
->bh
);
776 bs
->s
.end
= bs
->bh
->b_data
+ bs
->bh
->b_size
;
777 bs
->s
.here
= bs
->s
.first
;
778 error
= ext4_xattr_find_entry(&bs
->s
.here
, i
->name_index
,
779 i
->name
, bs
->bh
->b_size
, 1);
780 if (error
&& error
!= -ENODATA
)
782 bs
->s
.not_found
= error
;
791 ext4_xattr_block_set(handle_t
*handle
, struct inode
*inode
,
792 struct ext4_xattr_info
*i
,
793 struct ext4_xattr_block_find
*bs
)
795 struct super_block
*sb
= inode
->i_sb
;
796 struct buffer_head
*new_bh
= NULL
;
797 struct ext4_xattr_search
*s
= &bs
->s
;
798 struct mb_cache_entry
*ce
= NULL
;
800 struct mb_cache
*ext4_mb_cache
= EXT4_GET_MB_CACHE(inode
);
802 #define header(x) ((struct ext4_xattr_header *)(x))
804 if (i
->value
&& i
->value_len
> sb
->s_blocksize
)
807 BUFFER_TRACE(bs
->bh
, "get_write_access");
808 error
= ext4_journal_get_write_access(handle
, bs
->bh
);
813 if (header(s
->base
)->h_refcount
== cpu_to_le32(1)) {
814 __u32 hash
= le32_to_cpu(BHDR(bs
->bh
)->h_hash
);
817 * This must happen under buffer lock for
818 * ext4_xattr_block_set() to reliably detect modified
821 mb_cache_entry_delete_block(ext4_mb_cache
, hash
,
823 ea_bdebug(bs
->bh
, "modifying in-place");
824 error
= ext4_xattr_set_entry(i
, s
);
826 if (!IS_LAST_ENTRY(s
->first
))
827 ext4_xattr_rehash(header(s
->base
),
829 ext4_xattr_cache_insert(ext4_mb_cache
,
832 unlock_buffer(bs
->bh
);
833 if (error
== -EFSCORRUPTED
)
836 error
= ext4_handle_dirty_xattr_block(handle
,
843 int offset
= (char *)s
->here
- bs
->bh
->b_data
;
845 unlock_buffer(bs
->bh
);
846 ea_bdebug(bs
->bh
, "cloning");
847 s
->base
= kmalloc(bs
->bh
->b_size
, GFP_NOFS
);
851 memcpy(s
->base
, BHDR(bs
->bh
), bs
->bh
->b_size
);
852 s
->first
= ENTRY(header(s
->base
)+1);
853 header(s
->base
)->h_refcount
= cpu_to_le32(1);
854 s
->here
= ENTRY(s
->base
+ offset
);
855 s
->end
= s
->base
+ bs
->bh
->b_size
;
858 /* Allocate a buffer where we construct the new block. */
859 s
->base
= kzalloc(sb
->s_blocksize
, GFP_NOFS
);
860 /* assert(header == s->base) */
864 header(s
->base
)->h_magic
= cpu_to_le32(EXT4_XATTR_MAGIC
);
865 header(s
->base
)->h_blocks
= cpu_to_le32(1);
866 header(s
->base
)->h_refcount
= cpu_to_le32(1);
867 s
->first
= ENTRY(header(s
->base
)+1);
868 s
->here
= ENTRY(header(s
->base
)+1);
869 s
->end
= s
->base
+ sb
->s_blocksize
;
872 error
= ext4_xattr_set_entry(i
, s
);
873 if (error
== -EFSCORRUPTED
)
877 if (!IS_LAST_ENTRY(s
->first
))
878 ext4_xattr_rehash(header(s
->base
), s
->here
);
881 if (!IS_LAST_ENTRY(s
->first
)) {
882 new_bh
= ext4_xattr_cache_find(inode
, header(s
->base
), &ce
);
884 /* We found an identical block in the cache. */
885 if (new_bh
== bs
->bh
)
886 ea_bdebug(new_bh
, "keeping");
890 /* The old block is released after updating
892 error
= dquot_alloc_block(inode
,
893 EXT4_C2B(EXT4_SB(sb
), 1));
896 BUFFER_TRACE(new_bh
, "get_write_access");
897 error
= ext4_journal_get_write_access(handle
,
903 * We have to be careful about races with
904 * freeing, rehashing or adding references to
905 * xattr block. Once we hold buffer lock xattr
906 * block's state is stable so we can check
907 * whether the block got freed / rehashed or
908 * not. Since we unhash mbcache entry under
909 * buffer lock when freeing / rehashing xattr
910 * block, checking whether entry is still
911 * hashed is reliable. Same rules hold for
912 * e_reusable handling.
914 if (hlist_bl_unhashed(&ce
->e_hash_list
) ||
917 * Undo everything and check mbcache
920 unlock_buffer(new_bh
);
921 dquot_free_block(inode
,
922 EXT4_C2B(EXT4_SB(sb
),
925 mb_cache_entry_put(ext4_mb_cache
, ce
);
930 ref
= le32_to_cpu(BHDR(new_bh
)->h_refcount
) + 1;
931 BHDR(new_bh
)->h_refcount
= cpu_to_le32(ref
);
932 if (ref
>= EXT4_XATTR_REFCOUNT_MAX
)
934 ea_bdebug(new_bh
, "reusing; refcount now=%d",
936 unlock_buffer(new_bh
);
937 error
= ext4_handle_dirty_xattr_block(handle
,
943 mb_cache_entry_touch(ext4_mb_cache
, ce
);
944 mb_cache_entry_put(ext4_mb_cache
, ce
);
946 } else if (bs
->bh
&& s
->base
== bs
->bh
->b_data
) {
947 /* We were modifying this block in-place. */
948 ea_bdebug(bs
->bh
, "keeping this block");
952 /* We need to allocate a new block */
953 ext4_fsblk_t goal
, block
;
955 goal
= ext4_group_first_block_no(sb
,
956 EXT4_I(inode
)->i_block_group
);
958 /* non-extent files can't have physical blocks past 2^32 */
959 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)))
960 goal
= goal
& EXT4_MAX_BLOCK_FILE_PHYS
;
962 block
= ext4_new_meta_blocks(handle
, inode
, goal
, 0,
967 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)))
968 BUG_ON(block
> EXT4_MAX_BLOCK_FILE_PHYS
);
970 ea_idebug(inode
, "creating block %llu",
971 (unsigned long long)block
);
973 new_bh
= sb_getblk(sb
, block
);
974 if (unlikely(!new_bh
)) {
977 ext4_free_blocks(handle
, inode
, NULL
, block
, 1,
978 EXT4_FREE_BLOCKS_METADATA
);
982 error
= ext4_journal_get_create_access(handle
, new_bh
);
984 unlock_buffer(new_bh
);
988 memcpy(new_bh
->b_data
, s
->base
, new_bh
->b_size
);
989 set_buffer_uptodate(new_bh
);
990 unlock_buffer(new_bh
);
991 ext4_xattr_cache_insert(ext4_mb_cache
, new_bh
);
992 error
= ext4_handle_dirty_xattr_block(handle
,
999 /* Update the inode. */
1000 EXT4_I(inode
)->i_file_acl
= new_bh
? new_bh
->b_blocknr
: 0;
1002 /* Drop the previous xattr block. */
1003 if (bs
->bh
&& bs
->bh
!= new_bh
)
1004 ext4_xattr_release_block(handle
, inode
, bs
->bh
);
1009 mb_cache_entry_put(ext4_mb_cache
, ce
);
1011 if (!(bs
->bh
&& s
->base
== bs
->bh
->b_data
))
1017 dquot_free_block(inode
, EXT4_C2B(EXT4_SB(sb
), 1));
1021 EXT4_ERROR_INODE(inode
, "bad block %llu",
1022 EXT4_I(inode
)->i_file_acl
);
1028 int ext4_xattr_ibody_find(struct inode
*inode
, struct ext4_xattr_info
*i
,
1029 struct ext4_xattr_ibody_find
*is
)
1031 struct ext4_xattr_ibody_header
*header
;
1032 struct ext4_inode
*raw_inode
;
1035 if (EXT4_I(inode
)->i_extra_isize
== 0)
1037 raw_inode
= ext4_raw_inode(&is
->iloc
);
1038 header
= IHDR(inode
, raw_inode
);
1039 is
->s
.base
= is
->s
.first
= IFIRST(header
);
1040 is
->s
.here
= is
->s
.first
;
1041 is
->s
.end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
1042 if (ext4_test_inode_state(inode
, EXT4_STATE_XATTR
)) {
1043 error
= ext4_xattr_check_names(IFIRST(header
), is
->s
.end
,
1047 /* Find the named attribute. */
1048 error
= ext4_xattr_find_entry(&is
->s
.here
, i
->name_index
,
1049 i
->name
, is
->s
.end
-
1050 (void *)is
->s
.base
, 0);
1051 if (error
&& error
!= -ENODATA
)
1053 is
->s
.not_found
= error
;
1058 int ext4_xattr_ibody_inline_set(handle_t
*handle
, struct inode
*inode
,
1059 struct ext4_xattr_info
*i
,
1060 struct ext4_xattr_ibody_find
*is
)
1062 struct ext4_xattr_ibody_header
*header
;
1063 struct ext4_xattr_search
*s
= &is
->s
;
1066 if (EXT4_I(inode
)->i_extra_isize
== 0)
1068 error
= ext4_xattr_set_entry(i
, s
);
1070 if (error
== -ENOSPC
&&
1071 ext4_has_inline_data(inode
)) {
1072 error
= ext4_try_to_evict_inline_data(handle
, inode
,
1073 EXT4_XATTR_LEN(strlen(i
->name
) +
1074 EXT4_XATTR_SIZE(i
->value_len
)));
1077 error
= ext4_xattr_ibody_find(inode
, i
, is
);
1080 error
= ext4_xattr_set_entry(i
, s
);
1085 header
= IHDR(inode
, ext4_raw_inode(&is
->iloc
));
1086 if (!IS_LAST_ENTRY(s
->first
)) {
1087 header
->h_magic
= cpu_to_le32(EXT4_XATTR_MAGIC
);
1088 ext4_set_inode_state(inode
, EXT4_STATE_XATTR
);
1090 header
->h_magic
= cpu_to_le32(0);
1091 ext4_clear_inode_state(inode
, EXT4_STATE_XATTR
);
1096 static int ext4_xattr_ibody_set(handle_t
*handle
, struct inode
*inode
,
1097 struct ext4_xattr_info
*i
,
1098 struct ext4_xattr_ibody_find
*is
)
1100 struct ext4_xattr_ibody_header
*header
;
1101 struct ext4_xattr_search
*s
= &is
->s
;
1104 if (EXT4_I(inode
)->i_extra_isize
== 0)
1106 error
= ext4_xattr_set_entry(i
, s
);
1109 header
= IHDR(inode
, ext4_raw_inode(&is
->iloc
));
1110 if (!IS_LAST_ENTRY(s
->first
)) {
1111 header
->h_magic
= cpu_to_le32(EXT4_XATTR_MAGIC
);
1112 ext4_set_inode_state(inode
, EXT4_STATE_XATTR
);
1114 header
->h_magic
= cpu_to_le32(0);
1115 ext4_clear_inode_state(inode
, EXT4_STATE_XATTR
);
1120 static int ext4_xattr_value_same(struct ext4_xattr_search
*s
,
1121 struct ext4_xattr_info
*i
)
1125 if (le32_to_cpu(s
->here
->e_value_size
) != i
->value_len
)
1127 value
= ((void *)s
->base
) + le16_to_cpu(s
->here
->e_value_offs
);
1128 return !memcmp(value
, i
->value
, i
->value_len
);
1132 * ext4_xattr_set_handle()
1134 * Create, replace or remove an extended attribute for this inode. Value
1135 * is NULL to remove an existing extended attribute, and non-NULL to
1136 * either replace an existing extended attribute, or create a new extended
1137 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
1138 * specify that an extended attribute must exist and must not exist
1139 * previous to the call, respectively.
1141 * Returns 0, or a negative error number on failure.
1144 ext4_xattr_set_handle(handle_t
*handle
, struct inode
*inode
, int name_index
,
1145 const char *name
, const void *value
, size_t value_len
,
1148 struct ext4_xattr_info i
= {
1149 .name_index
= name_index
,
1152 .value_len
= value_len
,
1155 struct ext4_xattr_ibody_find is
= {
1156 .s
= { .not_found
= -ENODATA
, },
1158 struct ext4_xattr_block_find bs
= {
1159 .s
= { .not_found
= -ENODATA
, },
1161 unsigned long no_expand
;
1166 if (strlen(name
) > 255)
1168 down_write(&EXT4_I(inode
)->xattr_sem
);
1169 no_expand
= ext4_test_inode_state(inode
, EXT4_STATE_NO_EXPAND
);
1170 ext4_set_inode_state(inode
, EXT4_STATE_NO_EXPAND
);
1172 error
= ext4_reserve_inode_write(handle
, inode
, &is
.iloc
);
1176 if (ext4_test_inode_state(inode
, EXT4_STATE_NEW
)) {
1177 struct ext4_inode
*raw_inode
= ext4_raw_inode(&is
.iloc
);
1178 memset(raw_inode
, 0, EXT4_SB(inode
->i_sb
)->s_inode_size
);
1179 ext4_clear_inode_state(inode
, EXT4_STATE_NEW
);
1182 error
= ext4_xattr_ibody_find(inode
, &i
, &is
);
1186 error
= ext4_xattr_block_find(inode
, &i
, &bs
);
1189 if (is
.s
.not_found
&& bs
.s
.not_found
) {
1191 if (flags
& XATTR_REPLACE
)
1198 if (flags
& XATTR_CREATE
)
1202 if (!is
.s
.not_found
)
1203 error
= ext4_xattr_ibody_set(handle
, inode
, &i
, &is
);
1204 else if (!bs
.s
.not_found
)
1205 error
= ext4_xattr_block_set(handle
, inode
, &i
, &bs
);
1208 /* Xattr value did not change? Save us some work and bail out */
1209 if (!is
.s
.not_found
&& ext4_xattr_value_same(&is
.s
, &i
))
1211 if (!bs
.s
.not_found
&& ext4_xattr_value_same(&bs
.s
, &i
))
1214 error
= ext4_xattr_ibody_set(handle
, inode
, &i
, &is
);
1215 if (!error
&& !bs
.s
.not_found
) {
1217 error
= ext4_xattr_block_set(handle
, inode
, &i
, &bs
);
1218 } else if (error
== -ENOSPC
) {
1219 if (EXT4_I(inode
)->i_file_acl
&& !bs
.s
.base
) {
1220 error
= ext4_xattr_block_find(inode
, &i
, &bs
);
1224 error
= ext4_xattr_block_set(handle
, inode
, &i
, &bs
);
1227 if (!is
.s
.not_found
) {
1229 error
= ext4_xattr_ibody_set(handle
, inode
, &i
,
1235 ext4_xattr_update_super_block(handle
, inode
->i_sb
);
1236 inode
->i_ctime
= ext4_current_time(inode
);
1238 ext4_clear_inode_state(inode
, EXT4_STATE_NO_EXPAND
);
1239 error
= ext4_mark_iloc_dirty(handle
, inode
, &is
.iloc
);
1241 * The bh is consumed by ext4_mark_iloc_dirty, even with
1246 ext4_handle_sync(handle
);
1253 ext4_clear_inode_state(inode
, EXT4_STATE_NO_EXPAND
);
1254 up_write(&EXT4_I(inode
)->xattr_sem
);
1261 * Like ext4_xattr_set_handle, but start from an inode. This extended
1262 * attribute modification is a filesystem transaction by itself.
1264 * Returns 0, or a negative error number on failure.
1267 ext4_xattr_set(struct inode
*inode
, int name_index
, const char *name
,
1268 const void *value
, size_t value_len
, int flags
)
1271 int error
, retries
= 0;
1272 int credits
= ext4_jbd2_credits_xattr(inode
);
1275 handle
= ext4_journal_start(inode
, EXT4_HT_XATTR
, credits
);
1276 if (IS_ERR(handle
)) {
1277 error
= PTR_ERR(handle
);
1281 error
= ext4_xattr_set_handle(handle
, inode
, name_index
, name
,
1282 value
, value_len
, flags
);
1283 error2
= ext4_journal_stop(handle
);
1284 if (error
== -ENOSPC
&&
1285 ext4_should_retry_alloc(inode
->i_sb
, &retries
))
1295 * Shift the EA entries in the inode to create space for the increased
1298 static void ext4_xattr_shift_entries(struct ext4_xattr_entry
*entry
,
1299 int value_offs_shift
, void *to
,
1300 void *from
, size_t n
, int blocksize
)
1302 struct ext4_xattr_entry
*last
= entry
;
1305 /* Adjust the value offsets of the entries */
1306 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
1307 if (!last
->e_value_block
&& last
->e_value_size
) {
1308 new_offs
= le16_to_cpu(last
->e_value_offs
) +
1310 BUG_ON(new_offs
+ le32_to_cpu(last
->e_value_size
)
1312 last
->e_value_offs
= cpu_to_le16(new_offs
);
1315 /* Shift the entries by n bytes */
1316 memmove(to
, from
, n
);
1320 * Expand an inode by new_extra_isize bytes when EAs are present.
1321 * Returns 0 on success or negative error number on failure.
1323 int ext4_expand_extra_isize_ea(struct inode
*inode
, int new_extra_isize
,
1324 struct ext4_inode
*raw_inode
, handle_t
*handle
)
1326 struct ext4_xattr_ibody_header
*header
;
1327 struct ext4_xattr_entry
*entry
, *last
, *first
;
1328 struct buffer_head
*bh
= NULL
;
1329 struct ext4_xattr_ibody_find
*is
= NULL
;
1330 struct ext4_xattr_block_find
*bs
= NULL
;
1331 char *buffer
= NULL
, *b_entry_name
= NULL
;
1332 size_t min_offs
, free
;
1334 void *base
, *start
, *end
;
1335 int extra_isize
= 0, error
= 0, tried_min_extra_isize
= 0;
1336 int s_min_extra_isize
= le16_to_cpu(EXT4_SB(inode
->i_sb
)->s_es
->s_min_extra_isize
);
1338 down_write(&EXT4_I(inode
)->xattr_sem
);
1340 if (EXT4_I(inode
)->i_extra_isize
>= new_extra_isize
) {
1341 up_write(&EXT4_I(inode
)->xattr_sem
);
1345 header
= IHDR(inode
, raw_inode
);
1346 entry
= IFIRST(header
);
1349 * Check if enough free space is available in the inode to shift the
1350 * entries ahead by new_extra_isize.
1353 base
= start
= entry
;
1354 end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
1355 min_offs
= end
- base
;
1357 total_ino
= sizeof(struct ext4_xattr_ibody_header
);
1359 free
= ext4_xattr_free_space(last
, &min_offs
, base
, &total_ino
);
1360 if (free
>= new_extra_isize
) {
1361 entry
= IFIRST(header
);
1362 ext4_xattr_shift_entries(entry
, EXT4_I(inode
)->i_extra_isize
1363 - new_extra_isize
, (void *)raw_inode
+
1364 EXT4_GOOD_OLD_INODE_SIZE
+ new_extra_isize
,
1365 (void *)header
, total_ino
,
1366 inode
->i_sb
->s_blocksize
);
1367 EXT4_I(inode
)->i_extra_isize
= new_extra_isize
;
1373 * Enough free space isn't available in the inode, check if
1374 * EA block can hold new_extra_isize bytes.
1376 if (EXT4_I(inode
)->i_file_acl
) {
1377 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
1381 if (ext4_xattr_check_block(inode
, bh
)) {
1382 EXT4_ERROR_INODE(inode
, "bad block %llu",
1383 EXT4_I(inode
)->i_file_acl
);
1384 error
= -EFSCORRUPTED
;
1389 end
= bh
->b_data
+ bh
->b_size
;
1390 min_offs
= end
- base
;
1391 free
= ext4_xattr_free_space(first
, &min_offs
, base
, NULL
);
1392 if (free
< new_extra_isize
) {
1393 if (!tried_min_extra_isize
&& s_min_extra_isize
) {
1394 tried_min_extra_isize
++;
1395 new_extra_isize
= s_min_extra_isize
;
1403 free
= inode
->i_sb
->s_blocksize
;
1406 while (new_extra_isize
> 0) {
1407 size_t offs
, size
, entry_size
;
1408 struct ext4_xattr_entry
*small_entry
= NULL
;
1409 struct ext4_xattr_info i
= {
1413 unsigned int total_size
; /* EA entry size + value size */
1414 unsigned int shift_bytes
; /* No. of bytes to shift EAs by? */
1415 unsigned int min_total_size
= ~0U;
1417 is
= kzalloc(sizeof(struct ext4_xattr_ibody_find
), GFP_NOFS
);
1418 bs
= kzalloc(sizeof(struct ext4_xattr_block_find
), GFP_NOFS
);
1424 is
->s
.not_found
= -ENODATA
;
1425 bs
->s
.not_found
= -ENODATA
;
1429 last
= IFIRST(header
);
1430 /* Find the entry best suited to be pushed into EA block */
1432 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
1434 EXT4_XATTR_SIZE(le32_to_cpu(last
->e_value_size
)) +
1435 EXT4_XATTR_LEN(last
->e_name_len
);
1436 if (total_size
<= free
&& total_size
< min_total_size
) {
1437 if (total_size
< new_extra_isize
) {
1441 min_total_size
= total_size
;
1446 if (entry
== NULL
) {
1448 entry
= small_entry
;
1450 if (!tried_min_extra_isize
&&
1451 s_min_extra_isize
) {
1452 tried_min_extra_isize
++;
1453 new_extra_isize
= s_min_extra_isize
;
1454 kfree(is
); is
= NULL
;
1455 kfree(bs
); bs
= NULL
;
1463 offs
= le16_to_cpu(entry
->e_value_offs
);
1464 size
= le32_to_cpu(entry
->e_value_size
);
1465 entry_size
= EXT4_XATTR_LEN(entry
->e_name_len
);
1466 i
.name_index
= entry
->e_name_index
,
1467 buffer
= kmalloc(EXT4_XATTR_SIZE(size
), GFP_NOFS
);
1468 b_entry_name
= kmalloc(entry
->e_name_len
+ 1, GFP_NOFS
);
1469 if (!buffer
|| !b_entry_name
) {
1473 /* Save the entry name and the entry value */
1474 memcpy(buffer
, (void *)IFIRST(header
) + offs
,
1475 EXT4_XATTR_SIZE(size
));
1476 memcpy(b_entry_name
, entry
->e_name
, entry
->e_name_len
);
1477 b_entry_name
[entry
->e_name_len
] = '\0';
1478 i
.name
= b_entry_name
;
1480 error
= ext4_get_inode_loc(inode
, &is
->iloc
);
1484 error
= ext4_xattr_ibody_find(inode
, &i
, is
);
1488 /* Remove the chosen entry from the inode */
1489 error
= ext4_xattr_ibody_set(handle
, inode
, &i
, is
);
1493 entry
= IFIRST(header
);
1494 if (entry_size
+ EXT4_XATTR_SIZE(size
) >= new_extra_isize
)
1495 shift_bytes
= new_extra_isize
;
1497 shift_bytes
= entry_size
+ size
;
1498 /* Adjust the offsets and shift the remaining entries ahead */
1499 ext4_xattr_shift_entries(entry
, EXT4_I(inode
)->i_extra_isize
-
1500 shift_bytes
, (void *)raw_inode
+
1501 EXT4_GOOD_OLD_INODE_SIZE
+ extra_isize
+ shift_bytes
,
1502 (void *)header
, total_ino
- entry_size
,
1503 inode
->i_sb
->s_blocksize
);
1505 extra_isize
+= shift_bytes
;
1506 new_extra_isize
-= shift_bytes
;
1507 EXT4_I(inode
)->i_extra_isize
= extra_isize
;
1509 i
.name
= b_entry_name
;
1512 error
= ext4_xattr_block_find(inode
, &i
, bs
);
1516 /* Add entry which was removed from the inode into the block */
1517 error
= ext4_xattr_block_set(handle
, inode
, &i
, bs
);
1520 kfree(b_entry_name
);
1522 b_entry_name
= NULL
;
1524 brelse(is
->iloc
.bh
);
1529 up_write(&EXT4_I(inode
)->xattr_sem
);
1533 kfree(b_entry_name
);
1536 brelse(is
->iloc
.bh
);
1540 up_write(&EXT4_I(inode
)->xattr_sem
);
1547 * ext4_xattr_delete_inode()
1549 * Free extended attribute resources associated with this inode. This
1550 * is called immediately before an inode is freed. We have exclusive
1551 * access to the inode.
1554 ext4_xattr_delete_inode(handle_t
*handle
, struct inode
*inode
)
1556 struct buffer_head
*bh
= NULL
;
1558 if (!EXT4_I(inode
)->i_file_acl
)
1560 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
1562 EXT4_ERROR_INODE(inode
, "block %llu read error",
1563 EXT4_I(inode
)->i_file_acl
);
1566 if (BHDR(bh
)->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
) ||
1567 BHDR(bh
)->h_blocks
!= cpu_to_le32(1)) {
1568 EXT4_ERROR_INODE(inode
, "bad block %llu",
1569 EXT4_I(inode
)->i_file_acl
);
1572 ext4_xattr_release_block(handle
, inode
, bh
);
1573 EXT4_I(inode
)->i_file_acl
= 0;
1580 * ext4_xattr_cache_insert()
1582 * Create a new entry in the extended attribute cache, and insert
1583 * it unless such an entry is already in the cache.
1585 * Returns 0, or a negative error number on failure.
1588 ext4_xattr_cache_insert(struct mb_cache
*ext4_mb_cache
, struct buffer_head
*bh
)
1590 struct ext4_xattr_header
*header
= BHDR(bh
);
1591 __u32 hash
= le32_to_cpu(header
->h_hash
);
1592 int reusable
= le32_to_cpu(header
->h_refcount
) <
1593 EXT4_XATTR_REFCOUNT_MAX
;
1596 error
= mb_cache_entry_create(ext4_mb_cache
, GFP_NOFS
, hash
,
1597 bh
->b_blocknr
, reusable
);
1599 if (error
== -EBUSY
)
1600 ea_bdebug(bh
, "already in cache");
1602 ea_bdebug(bh
, "inserting [%x]", (int)hash
);
1608 * Compare two extended attribute blocks for equality.
1610 * Returns 0 if the blocks are equal, 1 if they differ, and
1611 * a negative error number on errors.
1614 ext4_xattr_cmp(struct ext4_xattr_header
*header1
,
1615 struct ext4_xattr_header
*header2
)
1617 struct ext4_xattr_entry
*entry1
, *entry2
;
1619 entry1
= ENTRY(header1
+1);
1620 entry2
= ENTRY(header2
+1);
1621 while (!IS_LAST_ENTRY(entry1
)) {
1622 if (IS_LAST_ENTRY(entry2
))
1624 if (entry1
->e_hash
!= entry2
->e_hash
||
1625 entry1
->e_name_index
!= entry2
->e_name_index
||
1626 entry1
->e_name_len
!= entry2
->e_name_len
||
1627 entry1
->e_value_size
!= entry2
->e_value_size
||
1628 memcmp(entry1
->e_name
, entry2
->e_name
, entry1
->e_name_len
))
1630 if (entry1
->e_value_block
!= 0 || entry2
->e_value_block
!= 0)
1631 return -EFSCORRUPTED
;
1632 if (memcmp((char *)header1
+ le16_to_cpu(entry1
->e_value_offs
),
1633 (char *)header2
+ le16_to_cpu(entry2
->e_value_offs
),
1634 le32_to_cpu(entry1
->e_value_size
)))
1637 entry1
= EXT4_XATTR_NEXT(entry1
);
1638 entry2
= EXT4_XATTR_NEXT(entry2
);
1640 if (!IS_LAST_ENTRY(entry2
))
1646 * ext4_xattr_cache_find()
1648 * Find an identical extended attribute block.
1650 * Returns a pointer to the block found, or NULL if such a block was
1651 * not found or an error occurred.
1653 static struct buffer_head
*
1654 ext4_xattr_cache_find(struct inode
*inode
, struct ext4_xattr_header
*header
,
1655 struct mb_cache_entry
**pce
)
1657 __u32 hash
= le32_to_cpu(header
->h_hash
);
1658 struct mb_cache_entry
*ce
;
1659 struct mb_cache
*ext4_mb_cache
= EXT4_GET_MB_CACHE(inode
);
1661 if (!header
->h_hash
)
1662 return NULL
; /* never share */
1663 ea_idebug(inode
, "looking for cached blocks [%x]", (int)hash
);
1664 ce
= mb_cache_entry_find_first(ext4_mb_cache
, hash
);
1666 struct buffer_head
*bh
;
1668 bh
= sb_bread(inode
->i_sb
, ce
->e_block
);
1670 EXT4_ERROR_INODE(inode
, "block %lu read error",
1671 (unsigned long) ce
->e_block
);
1672 } else if (ext4_xattr_cmp(header
, BHDR(bh
)) == 0) {
1677 ce
= mb_cache_entry_find_next(ext4_mb_cache
, ce
);
1682 #define NAME_HASH_SHIFT 5
1683 #define VALUE_HASH_SHIFT 16
1686 * ext4_xattr_hash_entry()
1688 * Compute the hash of an extended attribute.
1690 static inline void ext4_xattr_hash_entry(struct ext4_xattr_header
*header
,
1691 struct ext4_xattr_entry
*entry
)
1694 char *name
= entry
->e_name
;
1697 for (n
= 0; n
< entry
->e_name_len
; n
++) {
1698 hash
= (hash
<< NAME_HASH_SHIFT
) ^
1699 (hash
>> (8*sizeof(hash
) - NAME_HASH_SHIFT
)) ^
1703 if (entry
->e_value_block
== 0 && entry
->e_value_size
!= 0) {
1704 __le32
*value
= (__le32
*)((char *)header
+
1705 le16_to_cpu(entry
->e_value_offs
));
1706 for (n
= (le32_to_cpu(entry
->e_value_size
) +
1707 EXT4_XATTR_ROUND
) >> EXT4_XATTR_PAD_BITS
; n
; n
--) {
1708 hash
= (hash
<< VALUE_HASH_SHIFT
) ^
1709 (hash
>> (8*sizeof(hash
) - VALUE_HASH_SHIFT
)) ^
1710 le32_to_cpu(*value
++);
1713 entry
->e_hash
= cpu_to_le32(hash
);
1716 #undef NAME_HASH_SHIFT
1717 #undef VALUE_HASH_SHIFT
1719 #define BLOCK_HASH_SHIFT 16
1722 * ext4_xattr_rehash()
1724 * Re-compute the extended attribute hash value after an entry has changed.
1726 static void ext4_xattr_rehash(struct ext4_xattr_header
*header
,
1727 struct ext4_xattr_entry
*entry
)
1729 struct ext4_xattr_entry
*here
;
1732 ext4_xattr_hash_entry(header
, entry
);
1733 here
= ENTRY(header
+1);
1734 while (!IS_LAST_ENTRY(here
)) {
1735 if (!here
->e_hash
) {
1736 /* Block is not shared if an entry's hash value == 0 */
1740 hash
= (hash
<< BLOCK_HASH_SHIFT
) ^
1741 (hash
>> (8*sizeof(hash
) - BLOCK_HASH_SHIFT
)) ^
1742 le32_to_cpu(here
->e_hash
);
1743 here
= EXT4_XATTR_NEXT(here
);
1745 header
->h_hash
= cpu_to_le32(hash
);
1748 #undef BLOCK_HASH_SHIFT
1750 #define HASH_BUCKET_BITS 10
1753 ext4_xattr_create_cache(void)
1755 return mb_cache_create(HASH_BUCKET_BITS
);
1758 void ext4_xattr_destroy_cache(struct mb_cache
*cache
)
1761 mb_cache_destroy(cache
);