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, fmt, ...) \
65 printk(KERN_DEBUG "inode %s:%lu: " fmt "\n", \
66 inode->i_sb->s_id, inode->i_ino, ##__VA_ARGS__)
67 # define ea_bdebug(bh, fmt, ...) \
68 printk(KERN_DEBUG "block %pg:%lu: " fmt "\n", \
69 bh->b_bdev, (unsigned long)bh->b_blocknr, ##__VA_ARGS__)
71 # define ea_idebug(inode, fmt, ...) no_printk(fmt, ##__VA_ARGS__)
72 # define ea_bdebug(bh, fmt, ...) no_printk(fmt, ##__VA_ARGS__)
75 static void ext4_xattr_cache_insert(struct mb_cache
*, struct buffer_head
*);
76 static struct buffer_head
*ext4_xattr_cache_find(struct inode
*,
77 struct ext4_xattr_header
*,
78 struct mb_cache_entry
**);
79 static void ext4_xattr_rehash(struct ext4_xattr_header
*,
80 struct ext4_xattr_entry
*);
82 static const struct xattr_handler
* const ext4_xattr_handler_map
[] = {
83 [EXT4_XATTR_INDEX_USER
] = &ext4_xattr_user_handler
,
84 #ifdef CONFIG_EXT4_FS_POSIX_ACL
85 [EXT4_XATTR_INDEX_POSIX_ACL_ACCESS
] = &posix_acl_access_xattr_handler
,
86 [EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT
] = &posix_acl_default_xattr_handler
,
88 [EXT4_XATTR_INDEX_TRUSTED
] = &ext4_xattr_trusted_handler
,
89 #ifdef CONFIG_EXT4_FS_SECURITY
90 [EXT4_XATTR_INDEX_SECURITY
] = &ext4_xattr_security_handler
,
94 const struct xattr_handler
*ext4_xattr_handlers
[] = {
95 &ext4_xattr_user_handler
,
96 &ext4_xattr_trusted_handler
,
97 #ifdef CONFIG_EXT4_FS_POSIX_ACL
98 &posix_acl_access_xattr_handler
,
99 &posix_acl_default_xattr_handler
,
101 #ifdef CONFIG_EXT4_FS_SECURITY
102 &ext4_xattr_security_handler
,
107 #define EXT4_GET_MB_CACHE(inode) (((struct ext4_sb_info *) \
108 inode->i_sb->s_fs_info)->s_mb_cache)
110 static __le32
ext4_xattr_block_csum(struct inode
*inode
,
112 struct ext4_xattr_header
*hdr
)
114 struct ext4_sb_info
*sbi
= EXT4_SB(inode
->i_sb
);
116 __le64 dsk_block_nr
= cpu_to_le64(block_nr
);
117 __u32 dummy_csum
= 0;
118 int offset
= offsetof(struct ext4_xattr_header
, h_checksum
);
120 csum
= ext4_chksum(sbi
, sbi
->s_csum_seed
, (__u8
*)&dsk_block_nr
,
121 sizeof(dsk_block_nr
));
122 csum
= ext4_chksum(sbi
, csum
, (__u8
*)hdr
, offset
);
123 csum
= ext4_chksum(sbi
, csum
, (__u8
*)&dummy_csum
, sizeof(dummy_csum
));
124 offset
+= sizeof(dummy_csum
);
125 csum
= ext4_chksum(sbi
, csum
, (__u8
*)hdr
+ offset
,
126 EXT4_BLOCK_SIZE(inode
->i_sb
) - offset
);
128 return cpu_to_le32(csum
);
131 static int ext4_xattr_block_csum_verify(struct inode
*inode
,
132 struct buffer_head
*bh
)
134 struct ext4_xattr_header
*hdr
= BHDR(bh
);
137 if (ext4_has_metadata_csum(inode
->i_sb
)) {
139 ret
= (hdr
->h_checksum
== ext4_xattr_block_csum(inode
,
140 bh
->b_blocknr
, hdr
));
146 static void ext4_xattr_block_csum_set(struct inode
*inode
,
147 struct buffer_head
*bh
)
149 if (ext4_has_metadata_csum(inode
->i_sb
))
150 BHDR(bh
)->h_checksum
= ext4_xattr_block_csum(inode
,
151 bh
->b_blocknr
, BHDR(bh
));
154 static inline const struct xattr_handler
*
155 ext4_xattr_handler(int name_index
)
157 const struct xattr_handler
*handler
= NULL
;
159 if (name_index
> 0 && name_index
< ARRAY_SIZE(ext4_xattr_handler_map
))
160 handler
= ext4_xattr_handler_map
[name_index
];
165 ext4_xattr_check_entries(struct ext4_xattr_entry
*entry
, void *end
,
168 struct ext4_xattr_entry
*e
= entry
;
170 /* Find the end of the names list */
171 while (!IS_LAST_ENTRY(e
)) {
172 struct ext4_xattr_entry
*next
= EXT4_XATTR_NEXT(e
);
173 if ((void *)next
>= end
)
174 return -EFSCORRUPTED
;
178 /* Check the values */
179 while (!IS_LAST_ENTRY(entry
)) {
180 if (entry
->e_value_block
!= 0)
181 return -EFSCORRUPTED
;
182 if (entry
->e_value_size
!= 0) {
183 u16 offs
= le16_to_cpu(entry
->e_value_offs
);
184 u32 size
= le32_to_cpu(entry
->e_value_size
);
188 * The value cannot overlap the names, and the value
189 * with padding cannot extend beyond 'end'. Check both
190 * the padded and unpadded sizes, since the size may
191 * overflow to 0 when adding padding.
193 if (offs
> end
- value_start
)
194 return -EFSCORRUPTED
;
195 value
= value_start
+ offs
;
196 if (value
< (void *)e
+ sizeof(u32
) ||
197 size
> end
- value
||
198 EXT4_XATTR_SIZE(size
) > end
- value
)
199 return -EFSCORRUPTED
;
201 entry
= EXT4_XATTR_NEXT(entry
);
208 ext4_xattr_check_block(struct inode
*inode
, struct buffer_head
*bh
)
212 if (buffer_verified(bh
))
215 if (BHDR(bh
)->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
) ||
216 BHDR(bh
)->h_blocks
!= cpu_to_le32(1))
217 return -EFSCORRUPTED
;
218 if (!ext4_xattr_block_csum_verify(inode
, bh
))
220 error
= ext4_xattr_check_entries(BFIRST(bh
), bh
->b_data
+ bh
->b_size
,
223 set_buffer_verified(bh
);
228 __xattr_check_inode(struct inode
*inode
, struct ext4_xattr_ibody_header
*header
,
229 void *end
, const char *function
, unsigned int line
)
231 int error
= -EFSCORRUPTED
;
233 if (end
- (void *)header
< sizeof(*header
) + sizeof(u32
) ||
234 (header
->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
)))
236 error
= ext4_xattr_check_entries(IFIRST(header
), end
, IFIRST(header
));
239 __ext4_error_inode(inode
, function
, line
, 0,
240 "corrupted in-inode xattr");
244 #define xattr_check_inode(inode, header, end) \
245 __xattr_check_inode((inode), (header), (end), __func__, __LINE__)
248 ext4_xattr_find_entry(struct ext4_xattr_entry
**pentry
, int name_index
,
249 const char *name
, 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 return cmp
? -ENODATA
: 0;
273 ext4_xattr_block_get(struct inode
*inode
, int name_index
, const char *name
,
274 void *buffer
, size_t buffer_size
)
276 struct buffer_head
*bh
= NULL
;
277 struct ext4_xattr_entry
*entry
;
280 struct mb_cache
*ext4_mb_cache
= EXT4_GET_MB_CACHE(inode
);
282 ea_idebug(inode
, "name=%d.%s, buffer=%p, buffer_size=%ld",
283 name_index
, name
, buffer
, (long)buffer_size
);
286 if (!EXT4_I(inode
)->i_file_acl
)
288 ea_idebug(inode
, "reading block %llu",
289 (unsigned long long)EXT4_I(inode
)->i_file_acl
);
290 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
293 ea_bdebug(bh
, "b_count=%d, refcount=%d",
294 atomic_read(&(bh
->b_count
)), le32_to_cpu(BHDR(bh
)->h_refcount
));
295 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
, 1);
306 size
= le32_to_cpu(entry
->e_value_size
);
309 if (size
> buffer_size
)
311 memcpy(buffer
, bh
->b_data
+ le16_to_cpu(entry
->e_value_offs
),
322 ext4_xattr_ibody_get(struct inode
*inode
, int name_index
, const char *name
,
323 void *buffer
, size_t buffer_size
)
325 struct ext4_xattr_ibody_header
*header
;
326 struct ext4_xattr_entry
*entry
;
327 struct ext4_inode
*raw_inode
;
328 struct ext4_iloc iloc
;
333 if (!ext4_test_inode_state(inode
, EXT4_STATE_XATTR
))
335 error
= ext4_get_inode_loc(inode
, &iloc
);
338 raw_inode
= ext4_raw_inode(&iloc
);
339 header
= IHDR(inode
, raw_inode
);
340 end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
341 error
= xattr_check_inode(inode
, header
, end
);
344 entry
= IFIRST(header
);
345 error
= ext4_xattr_find_entry(&entry
, name_index
, name
, 0);
348 size
= le32_to_cpu(entry
->e_value_size
);
351 if (size
> buffer_size
)
353 memcpy(buffer
, (void *)IFIRST(header
) +
354 le16_to_cpu(entry
->e_value_offs
), size
);
366 * Copy an extended attribute into the buffer
367 * provided, or compute the buffer size required.
368 * Buffer is NULL to compute the size of the buffer required.
370 * Returns a negative error number on failure, or the number of bytes
371 * used / required on success.
374 ext4_xattr_get(struct inode
*inode
, int name_index
, const char *name
,
375 void *buffer
, size_t buffer_size
)
379 if (unlikely(ext4_forced_shutdown(EXT4_SB(inode
->i_sb
))))
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
= xattr_check_inode(inode
, header
, end
);
483 error
= ext4_xattr_list_entries(dentry
, IFIRST(header
),
484 buffer
, buffer_size
);
492 * Inode operation listxattr()
494 * d_inode(dentry)->i_rwsem: don't care
496 * Copy a list of attribute names into the buffer
497 * provided, or compute the buffer size required.
498 * Buffer is NULL to compute the size of the buffer required.
500 * Returns a negative error number on failure, or the number of bytes
501 * used / required on success.
504 ext4_listxattr(struct dentry
*dentry
, char *buffer
, size_t buffer_size
)
508 down_read(&EXT4_I(d_inode(dentry
))->xattr_sem
);
509 ret
= ret2
= ext4_xattr_ibody_list(dentry
, buffer
, buffer_size
);
516 ret
= ext4_xattr_block_list(dentry
, buffer
, buffer_size
);
521 up_read(&EXT4_I(d_inode(dentry
))->xattr_sem
);
526 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is
529 static void ext4_xattr_update_super_block(handle_t
*handle
,
530 struct super_block
*sb
)
532 if (ext4_has_feature_xattr(sb
))
535 BUFFER_TRACE(EXT4_SB(sb
)->s_sbh
, "get_write_access");
536 if (ext4_journal_get_write_access(handle
, EXT4_SB(sb
)->s_sbh
) == 0) {
537 ext4_set_feature_xattr(sb
);
538 ext4_handle_dirty_super(handle
, sb
);
543 * Release the xattr block BH: If the reference count is > 1, decrement it;
544 * otherwise free the block.
547 ext4_xattr_release_block(handle_t
*handle
, struct inode
*inode
,
548 struct buffer_head
*bh
)
550 struct mb_cache
*ext4_mb_cache
= EXT4_GET_MB_CACHE(inode
);
554 BUFFER_TRACE(bh
, "get_write_access");
555 error
= ext4_journal_get_write_access(handle
, bh
);
560 hash
= le32_to_cpu(BHDR(bh
)->h_hash
);
561 ref
= le32_to_cpu(BHDR(bh
)->h_refcount
);
563 ea_bdebug(bh
, "refcount now=0; freeing");
565 * This must happen under buffer lock for
566 * ext4_xattr_block_set() to reliably detect freed block
568 mb_cache_entry_delete_block(ext4_mb_cache
, hash
, bh
->b_blocknr
);
571 ext4_free_blocks(handle
, inode
, bh
, 0, 1,
572 EXT4_FREE_BLOCKS_METADATA
|
573 EXT4_FREE_BLOCKS_FORGET
);
576 BHDR(bh
)->h_refcount
= cpu_to_le32(ref
);
577 if (ref
== EXT4_XATTR_REFCOUNT_MAX
- 1) {
578 struct mb_cache_entry
*ce
;
580 ce
= mb_cache_entry_get(ext4_mb_cache
, hash
,
584 mb_cache_entry_put(ext4_mb_cache
, ce
);
588 ext4_xattr_block_csum_set(inode
, bh
);
590 * Beware of this ugliness: Releasing of xattr block references
591 * from different inodes can race and so we have to protect
592 * from a race where someone else frees the block (and releases
593 * its journal_head) before we are done dirtying the buffer. In
594 * nojournal mode this race is harmless and we actually cannot
595 * call ext4_handle_dirty_metadata() with locked buffer as
596 * that function can call sync_dirty_buffer() so for that case
597 * we handle the dirtying after unlocking the buffer.
599 if (ext4_handle_valid(handle
))
600 error
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
602 if (!ext4_handle_valid(handle
))
603 error
= ext4_handle_dirty_metadata(handle
, inode
, bh
);
605 ext4_handle_sync(handle
);
606 dquot_free_block(inode
, EXT4_C2B(EXT4_SB(inode
->i_sb
), 1));
607 ea_bdebug(bh
, "refcount now=%d; releasing",
608 le32_to_cpu(BHDR(bh
)->h_refcount
));
611 ext4_std_error(inode
->i_sb
, error
);
616 * Find the available free space for EAs. This also returns the total number of
617 * bytes used by EA entries.
619 static size_t ext4_xattr_free_space(struct ext4_xattr_entry
*last
,
620 size_t *min_offs
, void *base
, int *total
)
622 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
623 if (last
->e_value_size
) {
624 size_t offs
= le16_to_cpu(last
->e_value_offs
);
625 if (offs
< *min_offs
)
629 *total
+= EXT4_XATTR_LEN(last
->e_name_len
);
631 return (*min_offs
- ((void *)last
- base
) - sizeof(__u32
));
635 ext4_xattr_set_entry(struct ext4_xattr_info
*i
, struct ext4_xattr_search
*s
)
637 struct ext4_xattr_entry
*last
;
638 size_t free
, min_offs
= s
->end
- s
->base
, name_len
= strlen(i
->name
);
640 /* Compute min_offs and last. */
642 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
643 if (last
->e_value_size
) {
644 size_t offs
= le16_to_cpu(last
->e_value_offs
);
649 free
= min_offs
- ((void *)last
- s
->base
) - sizeof(__u32
);
651 if (s
->here
->e_value_size
) {
652 size_t size
= le32_to_cpu(s
->here
->e_value_size
);
653 free
+= EXT4_XATTR_SIZE(size
);
655 free
+= EXT4_XATTR_LEN(name_len
);
658 if (free
< EXT4_XATTR_LEN(name_len
) +
659 EXT4_XATTR_SIZE(i
->value_len
))
663 if (i
->value
&& s
->not_found
) {
664 /* Insert the new name. */
665 size_t size
= EXT4_XATTR_LEN(name_len
);
666 size_t rest
= (void *)last
- (void *)s
->here
+ sizeof(__u32
);
667 memmove((void *)s
->here
+ size
, s
->here
, rest
);
668 memset(s
->here
, 0, size
);
669 s
->here
->e_name_index
= i
->name_index
;
670 s
->here
->e_name_len
= name_len
;
671 memcpy(s
->here
->e_name
, i
->name
, name_len
);
673 if (s
->here
->e_value_size
) {
674 void *first_val
= s
->base
+ min_offs
;
675 size_t offs
= le16_to_cpu(s
->here
->e_value_offs
);
676 void *val
= s
->base
+ offs
;
677 size_t size
= EXT4_XATTR_SIZE(
678 le32_to_cpu(s
->here
->e_value_size
));
680 if (i
->value
&& size
== EXT4_XATTR_SIZE(i
->value_len
)) {
681 /* The old and the new value have the same
682 size. Just replace. */
683 s
->here
->e_value_size
=
684 cpu_to_le32(i
->value_len
);
685 if (i
->value
== EXT4_ZERO_XATTR_VALUE
) {
686 memset(val
, 0, size
);
688 /* Clear pad bytes first. */
689 memset(val
+ size
- EXT4_XATTR_PAD
, 0,
691 memcpy(val
, i
->value
, i
->value_len
);
696 /* Remove the old value. */
697 memmove(first_val
+ size
, first_val
, val
- first_val
);
698 memset(first_val
, 0, size
);
699 s
->here
->e_value_size
= 0;
700 s
->here
->e_value_offs
= 0;
703 /* Adjust all value offsets. */
705 while (!IS_LAST_ENTRY(last
)) {
706 size_t o
= le16_to_cpu(last
->e_value_offs
);
707 if (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
,
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 ext4_xattr_block_csum_set(inode
, bs
->bh
);
833 unlock_buffer(bs
->bh
);
834 if (error
== -EFSCORRUPTED
)
837 error
= ext4_handle_dirty_metadata(handle
,
844 int offset
= (char *)s
->here
- bs
->bh
->b_data
;
846 unlock_buffer(bs
->bh
);
847 ea_bdebug(bs
->bh
, "cloning");
848 s
->base
= kmalloc(bs
->bh
->b_size
, GFP_NOFS
);
852 memcpy(s
->base
, BHDR(bs
->bh
), bs
->bh
->b_size
);
853 s
->first
= ENTRY(header(s
->base
)+1);
854 header(s
->base
)->h_refcount
= cpu_to_le32(1);
855 s
->here
= ENTRY(s
->base
+ offset
);
856 s
->end
= s
->base
+ bs
->bh
->b_size
;
859 /* Allocate a buffer where we construct the new block. */
860 s
->base
= kzalloc(sb
->s_blocksize
, GFP_NOFS
);
861 /* assert(header == s->base) */
865 header(s
->base
)->h_magic
= cpu_to_le32(EXT4_XATTR_MAGIC
);
866 header(s
->base
)->h_blocks
= cpu_to_le32(1);
867 header(s
->base
)->h_refcount
= cpu_to_le32(1);
868 s
->first
= ENTRY(header(s
->base
)+1);
869 s
->here
= ENTRY(header(s
->base
)+1);
870 s
->end
= s
->base
+ sb
->s_blocksize
;
873 error
= ext4_xattr_set_entry(i
, s
);
874 if (error
== -EFSCORRUPTED
)
878 if (!IS_LAST_ENTRY(s
->first
))
879 ext4_xattr_rehash(header(s
->base
), s
->here
);
882 if (!IS_LAST_ENTRY(s
->first
)) {
883 new_bh
= ext4_xattr_cache_find(inode
, header(s
->base
), &ce
);
885 /* We found an identical block in the cache. */
886 if (new_bh
== bs
->bh
)
887 ea_bdebug(new_bh
, "keeping");
891 /* The old block is released after updating
893 error
= dquot_alloc_block(inode
,
894 EXT4_C2B(EXT4_SB(sb
), 1));
897 BUFFER_TRACE(new_bh
, "get_write_access");
898 error
= ext4_journal_get_write_access(handle
,
904 * We have to be careful about races with
905 * freeing, rehashing or adding references to
906 * xattr block. Once we hold buffer lock xattr
907 * block's state is stable so we can check
908 * whether the block got freed / rehashed or
909 * not. Since we unhash mbcache entry under
910 * buffer lock when freeing / rehashing xattr
911 * block, checking whether entry is still
912 * hashed is reliable. Same rules hold for
913 * e_reusable handling.
915 if (hlist_bl_unhashed(&ce
->e_hash_list
) ||
918 * Undo everything and check mbcache
921 unlock_buffer(new_bh
);
922 dquot_free_block(inode
,
923 EXT4_C2B(EXT4_SB(sb
),
926 mb_cache_entry_put(ext4_mb_cache
, ce
);
931 ref
= le32_to_cpu(BHDR(new_bh
)->h_refcount
) + 1;
932 BHDR(new_bh
)->h_refcount
= cpu_to_le32(ref
);
933 if (ref
>= EXT4_XATTR_REFCOUNT_MAX
)
935 ea_bdebug(new_bh
, "reusing; refcount now=%d",
937 ext4_xattr_block_csum_set(inode
, new_bh
);
938 unlock_buffer(new_bh
);
939 error
= ext4_handle_dirty_metadata(handle
,
945 mb_cache_entry_touch(ext4_mb_cache
, ce
);
946 mb_cache_entry_put(ext4_mb_cache
, ce
);
948 } else if (bs
->bh
&& s
->base
== bs
->bh
->b_data
) {
949 /* We were modifying this block in-place. */
950 ea_bdebug(bs
->bh
, "keeping this block");
954 /* We need to allocate a new block */
955 ext4_fsblk_t goal
, block
;
957 goal
= ext4_group_first_block_no(sb
,
958 EXT4_I(inode
)->i_block_group
);
960 /* non-extent files can't have physical blocks past 2^32 */
961 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)))
962 goal
= goal
& EXT4_MAX_BLOCK_FILE_PHYS
;
964 block
= ext4_new_meta_blocks(handle
, inode
, goal
, 0,
969 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)))
970 BUG_ON(block
> EXT4_MAX_BLOCK_FILE_PHYS
);
972 ea_idebug(inode
, "creating block %llu",
973 (unsigned long long)block
);
975 new_bh
= sb_getblk(sb
, block
);
976 if (unlikely(!new_bh
)) {
979 ext4_free_blocks(handle
, inode
, NULL
, block
, 1,
980 EXT4_FREE_BLOCKS_METADATA
);
984 error
= ext4_journal_get_create_access(handle
, new_bh
);
986 unlock_buffer(new_bh
);
990 memcpy(new_bh
->b_data
, s
->base
, new_bh
->b_size
);
991 ext4_xattr_block_csum_set(inode
, new_bh
);
992 set_buffer_uptodate(new_bh
);
993 unlock_buffer(new_bh
);
994 ext4_xattr_cache_insert(ext4_mb_cache
, new_bh
);
995 error
= ext4_handle_dirty_metadata(handle
, inode
,
1002 /* Update the inode. */
1003 EXT4_I(inode
)->i_file_acl
= new_bh
? new_bh
->b_blocknr
: 0;
1005 /* Drop the previous xattr block. */
1006 if (bs
->bh
&& bs
->bh
!= new_bh
)
1007 ext4_xattr_release_block(handle
, inode
, bs
->bh
);
1012 mb_cache_entry_put(ext4_mb_cache
, ce
);
1014 if (!(bs
->bh
&& s
->base
== bs
->bh
->b_data
))
1020 dquot_free_block(inode
, EXT4_C2B(EXT4_SB(sb
), 1));
1024 EXT4_ERROR_INODE(inode
, "bad block %llu",
1025 EXT4_I(inode
)->i_file_acl
);
1031 int ext4_xattr_ibody_find(struct inode
*inode
, struct ext4_xattr_info
*i
,
1032 struct ext4_xattr_ibody_find
*is
)
1034 struct ext4_xattr_ibody_header
*header
;
1035 struct ext4_inode
*raw_inode
;
1038 if (EXT4_I(inode
)->i_extra_isize
== 0)
1040 raw_inode
= ext4_raw_inode(&is
->iloc
);
1041 header
= IHDR(inode
, raw_inode
);
1042 is
->s
.base
= is
->s
.first
= IFIRST(header
);
1043 is
->s
.here
= is
->s
.first
;
1044 is
->s
.end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
1045 if (ext4_test_inode_state(inode
, EXT4_STATE_XATTR
)) {
1046 error
= xattr_check_inode(inode
, header
, is
->s
.end
);
1049 /* Find the named attribute. */
1050 error
= ext4_xattr_find_entry(&is
->s
.here
, i
->name_index
,
1052 if (error
&& error
!= -ENODATA
)
1054 is
->s
.not_found
= error
;
1059 int ext4_xattr_ibody_inline_set(handle_t
*handle
, struct inode
*inode
,
1060 struct ext4_xattr_info
*i
,
1061 struct ext4_xattr_ibody_find
*is
)
1063 struct ext4_xattr_ibody_header
*header
;
1064 struct ext4_xattr_search
*s
= &is
->s
;
1067 if (EXT4_I(inode
)->i_extra_isize
== 0)
1069 error
= ext4_xattr_set_entry(i
, s
);
1071 if (error
== -ENOSPC
&&
1072 ext4_has_inline_data(inode
)) {
1073 error
= ext4_try_to_evict_inline_data(handle
, inode
,
1074 EXT4_XATTR_LEN(strlen(i
->name
) +
1075 EXT4_XATTR_SIZE(i
->value_len
)));
1078 error
= ext4_xattr_ibody_find(inode
, i
, is
);
1081 error
= ext4_xattr_set_entry(i
, s
);
1086 header
= IHDR(inode
, ext4_raw_inode(&is
->iloc
));
1087 if (!IS_LAST_ENTRY(s
->first
)) {
1088 header
->h_magic
= cpu_to_le32(EXT4_XATTR_MAGIC
);
1089 ext4_set_inode_state(inode
, EXT4_STATE_XATTR
);
1091 header
->h_magic
= cpu_to_le32(0);
1092 ext4_clear_inode_state(inode
, EXT4_STATE_XATTR
);
1097 static int ext4_xattr_ibody_set(struct inode
*inode
,
1098 struct ext4_xattr_info
*i
,
1099 struct ext4_xattr_ibody_find
*is
)
1101 struct ext4_xattr_ibody_header
*header
;
1102 struct ext4_xattr_search
*s
= &is
->s
;
1105 if (EXT4_I(inode
)->i_extra_isize
== 0)
1107 error
= ext4_xattr_set_entry(i
, s
);
1110 header
= IHDR(inode
, ext4_raw_inode(&is
->iloc
));
1111 if (!IS_LAST_ENTRY(s
->first
)) {
1112 header
->h_magic
= cpu_to_le32(EXT4_XATTR_MAGIC
);
1113 ext4_set_inode_state(inode
, EXT4_STATE_XATTR
);
1115 header
->h_magic
= cpu_to_le32(0);
1116 ext4_clear_inode_state(inode
, EXT4_STATE_XATTR
);
1121 static int ext4_xattr_value_same(struct ext4_xattr_search
*s
,
1122 struct ext4_xattr_info
*i
)
1126 if (le32_to_cpu(s
->here
->e_value_size
) != i
->value_len
)
1128 value
= ((void *)s
->base
) + le16_to_cpu(s
->here
->e_value_offs
);
1129 return !memcmp(value
, i
->value
, i
->value_len
);
1133 * ext4_xattr_set_handle()
1135 * Create, replace or remove an extended attribute for this inode. Value
1136 * is NULL to remove an existing extended attribute, and non-NULL to
1137 * either replace an existing extended attribute, or create a new extended
1138 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
1139 * specify that an extended attribute must exist and must not exist
1140 * previous to the call, respectively.
1142 * Returns 0, or a negative error number on failure.
1145 ext4_xattr_set_handle(handle_t
*handle
, struct inode
*inode
, int name_index
,
1146 const char *name
, const void *value
, size_t value_len
,
1149 struct ext4_xattr_info i
= {
1150 .name_index
= name_index
,
1153 .value_len
= value_len
,
1156 struct ext4_xattr_ibody_find is
= {
1157 .s
= { .not_found
= -ENODATA
, },
1159 struct ext4_xattr_block_find bs
= {
1160 .s
= { .not_found
= -ENODATA
, },
1167 if (strlen(name
) > 255)
1169 ext4_write_lock_xattr(inode
, &no_expand
);
1171 error
= ext4_reserve_inode_write(handle
, inode
, &is
.iloc
);
1175 if (ext4_test_inode_state(inode
, EXT4_STATE_NEW
)) {
1176 struct ext4_inode
*raw_inode
= ext4_raw_inode(&is
.iloc
);
1177 memset(raw_inode
, 0, EXT4_SB(inode
->i_sb
)->s_inode_size
);
1178 ext4_clear_inode_state(inode
, EXT4_STATE_NEW
);
1181 error
= ext4_xattr_ibody_find(inode
, &i
, &is
);
1185 error
= ext4_xattr_block_find(inode
, &i
, &bs
);
1188 if (is
.s
.not_found
&& bs
.s
.not_found
) {
1190 if (flags
& XATTR_REPLACE
)
1197 if (flags
& XATTR_CREATE
)
1201 if (!is
.s
.not_found
)
1202 error
= ext4_xattr_ibody_set(inode
, &i
, &is
);
1203 else if (!bs
.s
.not_found
)
1204 error
= ext4_xattr_block_set(handle
, inode
, &i
, &bs
);
1207 /* Xattr value did not change? Save us some work and bail out */
1208 if (!is
.s
.not_found
&& ext4_xattr_value_same(&is
.s
, &i
))
1210 if (!bs
.s
.not_found
&& ext4_xattr_value_same(&bs
.s
, &i
))
1213 error
= ext4_xattr_ibody_set(inode
, &i
, &is
);
1214 if (!error
&& !bs
.s
.not_found
) {
1216 error
= ext4_xattr_block_set(handle
, inode
, &i
, &bs
);
1217 } else if (error
== -ENOSPC
) {
1218 if (EXT4_I(inode
)->i_file_acl
&& !bs
.s
.base
) {
1219 error
= ext4_xattr_block_find(inode
, &i
, &bs
);
1223 error
= ext4_xattr_block_set(handle
, inode
, &i
, &bs
);
1226 if (!is
.s
.not_found
) {
1228 error
= ext4_xattr_ibody_set(inode
, &i
, &is
);
1233 ext4_xattr_update_super_block(handle
, inode
->i_sb
);
1234 inode
->i_ctime
= current_time(inode
);
1237 error
= ext4_mark_iloc_dirty(handle
, inode
, &is
.iloc
);
1239 * The bh is consumed by ext4_mark_iloc_dirty, even with
1244 ext4_handle_sync(handle
);
1250 ext4_write_unlock_xattr(inode
, &no_expand
);
1257 * Like ext4_xattr_set_handle, but start from an inode. This extended
1258 * attribute modification is a filesystem transaction by itself.
1260 * Returns 0, or a negative error number on failure.
1263 ext4_xattr_set(struct inode
*inode
, int name_index
, const char *name
,
1264 const void *value
, size_t value_len
, int flags
)
1267 int error
, retries
= 0;
1268 int credits
= ext4_jbd2_credits_xattr(inode
);
1271 handle
= ext4_journal_start(inode
, EXT4_HT_XATTR
, credits
);
1272 if (IS_ERR(handle
)) {
1273 error
= PTR_ERR(handle
);
1277 error
= ext4_xattr_set_handle(handle
, inode
, name_index
, name
,
1278 value
, value_len
, flags
);
1279 error2
= ext4_journal_stop(handle
);
1280 if (error
== -ENOSPC
&&
1281 ext4_should_retry_alloc(inode
->i_sb
, &retries
))
1291 * Shift the EA entries in the inode to create space for the increased
1294 static void ext4_xattr_shift_entries(struct ext4_xattr_entry
*entry
,
1295 int value_offs_shift
, void *to
,
1296 void *from
, size_t n
)
1298 struct ext4_xattr_entry
*last
= entry
;
1301 /* We always shift xattr headers further thus offsets get lower */
1302 BUG_ON(value_offs_shift
> 0);
1304 /* Adjust the value offsets of the entries */
1305 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
1306 if (last
->e_value_size
) {
1307 new_offs
= le16_to_cpu(last
->e_value_offs
) +
1309 last
->e_value_offs
= cpu_to_le16(new_offs
);
1312 /* Shift the entries by n bytes */
1313 memmove(to
, from
, n
);
1317 * Move xattr pointed to by 'entry' from inode into external xattr block
1319 static int ext4_xattr_move_to_block(handle_t
*handle
, struct inode
*inode
,
1320 struct ext4_inode
*raw_inode
,
1321 struct ext4_xattr_entry
*entry
)
1323 struct ext4_xattr_ibody_find
*is
= NULL
;
1324 struct ext4_xattr_block_find
*bs
= NULL
;
1325 char *buffer
= NULL
, *b_entry_name
= NULL
;
1326 size_t value_offs
, value_size
;
1327 struct ext4_xattr_info i
= {
1330 .name_index
= entry
->e_name_index
,
1332 struct ext4_xattr_ibody_header
*header
= IHDR(inode
, raw_inode
);
1335 value_offs
= le16_to_cpu(entry
->e_value_offs
);
1336 value_size
= le32_to_cpu(entry
->e_value_size
);
1338 is
= kzalloc(sizeof(struct ext4_xattr_ibody_find
), GFP_NOFS
);
1339 bs
= kzalloc(sizeof(struct ext4_xattr_block_find
), GFP_NOFS
);
1340 buffer
= kmalloc(value_size
, GFP_NOFS
);
1341 b_entry_name
= kmalloc(entry
->e_name_len
+ 1, GFP_NOFS
);
1342 if (!is
|| !bs
|| !buffer
|| !b_entry_name
) {
1347 is
->s
.not_found
= -ENODATA
;
1348 bs
->s
.not_found
= -ENODATA
;
1352 /* Save the entry name and the entry value */
1353 memcpy(buffer
, (void *)IFIRST(header
) + value_offs
, value_size
);
1354 memcpy(b_entry_name
, entry
->e_name
, entry
->e_name_len
);
1355 b_entry_name
[entry
->e_name_len
] = '\0';
1356 i
.name
= b_entry_name
;
1358 error
= ext4_get_inode_loc(inode
, &is
->iloc
);
1362 error
= ext4_xattr_ibody_find(inode
, &i
, is
);
1366 /* Remove the chosen entry from the inode */
1367 error
= ext4_xattr_ibody_set(inode
, &i
, is
);
1371 i
.name
= b_entry_name
;
1373 i
.value_len
= value_size
;
1374 error
= ext4_xattr_block_find(inode
, &i
, bs
);
1378 /* Add entry which was removed from the inode into the block */
1379 error
= ext4_xattr_block_set(handle
, inode
, &i
, bs
);
1384 kfree(b_entry_name
);
1387 brelse(is
->iloc
.bh
);
1394 static int ext4_xattr_make_inode_space(handle_t
*handle
, struct inode
*inode
,
1395 struct ext4_inode
*raw_inode
,
1396 int isize_diff
, size_t ifree
,
1397 size_t bfree
, int *total_ino
)
1399 struct ext4_xattr_ibody_header
*header
= IHDR(inode
, raw_inode
);
1400 struct ext4_xattr_entry
*small_entry
;
1401 struct ext4_xattr_entry
*entry
;
1402 struct ext4_xattr_entry
*last
;
1403 unsigned int entry_size
; /* EA entry size */
1404 unsigned int total_size
; /* EA entry size + value size */
1405 unsigned int min_total_size
;
1408 while (isize_diff
> ifree
) {
1411 min_total_size
= ~0U;
1412 last
= IFIRST(header
);
1413 /* Find the entry best suited to be pushed into EA block */
1414 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
1416 EXT4_XATTR_SIZE(le32_to_cpu(last
->e_value_size
)) +
1417 EXT4_XATTR_LEN(last
->e_name_len
);
1418 if (total_size
<= bfree
&&
1419 total_size
< min_total_size
) {
1420 if (total_size
+ ifree
< isize_diff
) {
1424 min_total_size
= total_size
;
1429 if (entry
== NULL
) {
1430 if (small_entry
== NULL
)
1432 entry
= small_entry
;
1435 entry_size
= EXT4_XATTR_LEN(entry
->e_name_len
);
1436 total_size
= entry_size
+
1437 EXT4_XATTR_SIZE(le32_to_cpu(entry
->e_value_size
));
1438 error
= ext4_xattr_move_to_block(handle
, inode
, raw_inode
,
1443 *total_ino
-= entry_size
;
1444 ifree
+= total_size
;
1445 bfree
-= total_size
;
1452 * Expand an inode by new_extra_isize bytes when EAs are present.
1453 * Returns 0 on success or negative error number on failure.
1455 int ext4_expand_extra_isize_ea(struct inode
*inode
, int new_extra_isize
,
1456 struct ext4_inode
*raw_inode
, handle_t
*handle
)
1458 struct ext4_xattr_ibody_header
*header
;
1459 struct buffer_head
*bh
= NULL
;
1461 size_t ifree
, bfree
;
1464 int error
= 0, tried_min_extra_isize
= 0;
1465 int s_min_extra_isize
= le16_to_cpu(EXT4_SB(inode
->i_sb
)->s_es
->s_min_extra_isize
);
1466 int isize_diff
; /* How much do we need to grow i_extra_isize */
1469 if (ext4_write_trylock_xattr(inode
, &no_expand
) == 0)
1473 isize_diff
= new_extra_isize
- EXT4_I(inode
)->i_extra_isize
;
1474 if (EXT4_I(inode
)->i_extra_isize
>= new_extra_isize
)
1477 header
= IHDR(inode
, raw_inode
);
1480 * Check if enough free space is available in the inode to shift the
1481 * entries ahead by new_extra_isize.
1484 base
= IFIRST(header
);
1485 end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
1486 min_offs
= end
- base
;
1487 total_ino
= sizeof(struct ext4_xattr_ibody_header
);
1489 error
= xattr_check_inode(inode
, header
, end
);
1493 ifree
= ext4_xattr_free_space(base
, &min_offs
, base
, &total_ino
);
1494 if (ifree
>= isize_diff
)
1498 * Enough free space isn't available in the inode, check if
1499 * EA block can hold new_extra_isize bytes.
1501 if (EXT4_I(inode
)->i_file_acl
) {
1502 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
1506 if (ext4_xattr_check_block(inode
, bh
)) {
1507 EXT4_ERROR_INODE(inode
, "bad block %llu",
1508 EXT4_I(inode
)->i_file_acl
);
1509 error
= -EFSCORRUPTED
;
1513 end
= bh
->b_data
+ bh
->b_size
;
1514 min_offs
= end
- base
;
1515 bfree
= ext4_xattr_free_space(BFIRST(bh
), &min_offs
, base
,
1517 if (bfree
+ ifree
< isize_diff
) {
1518 if (!tried_min_extra_isize
&& s_min_extra_isize
) {
1519 tried_min_extra_isize
++;
1520 new_extra_isize
= s_min_extra_isize
;
1528 bfree
= inode
->i_sb
->s_blocksize
;
1531 error
= ext4_xattr_make_inode_space(handle
, inode
, raw_inode
,
1532 isize_diff
, ifree
, bfree
,
1535 if (error
== -ENOSPC
&& !tried_min_extra_isize
&&
1536 s_min_extra_isize
) {
1537 tried_min_extra_isize
++;
1538 new_extra_isize
= s_min_extra_isize
;
1545 /* Adjust the offsets and shift the remaining entries ahead */
1546 ext4_xattr_shift_entries(IFIRST(header
), EXT4_I(inode
)->i_extra_isize
1547 - new_extra_isize
, (void *)raw_inode
+
1548 EXT4_GOOD_OLD_INODE_SIZE
+ new_extra_isize
,
1549 (void *)header
, total_ino
);
1550 EXT4_I(inode
)->i_extra_isize
= new_extra_isize
;
1553 ext4_write_unlock_xattr(inode
, &no_expand
);
1559 * Inode size expansion failed; don't try again
1562 ext4_write_unlock_xattr(inode
, &no_expand
);
1569 * ext4_xattr_delete_inode()
1571 * Free extended attribute resources associated with this inode. This
1572 * is called immediately before an inode is freed. We have exclusive
1573 * access to the inode.
1576 ext4_xattr_delete_inode(handle_t
*handle
, struct inode
*inode
)
1578 struct buffer_head
*bh
= NULL
;
1580 if (!EXT4_I(inode
)->i_file_acl
)
1582 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
1584 EXT4_ERROR_INODE(inode
, "block %llu read error",
1585 EXT4_I(inode
)->i_file_acl
);
1588 if (BHDR(bh
)->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
) ||
1589 BHDR(bh
)->h_blocks
!= cpu_to_le32(1)) {
1590 EXT4_ERROR_INODE(inode
, "bad block %llu",
1591 EXT4_I(inode
)->i_file_acl
);
1594 ext4_xattr_release_block(handle
, inode
, bh
);
1595 EXT4_I(inode
)->i_file_acl
= 0;
1602 * ext4_xattr_cache_insert()
1604 * Create a new entry in the extended attribute cache, and insert
1605 * it unless such an entry is already in the cache.
1607 * Returns 0, or a negative error number on failure.
1610 ext4_xattr_cache_insert(struct mb_cache
*ext4_mb_cache
, struct buffer_head
*bh
)
1612 struct ext4_xattr_header
*header
= BHDR(bh
);
1613 __u32 hash
= le32_to_cpu(header
->h_hash
);
1614 int reusable
= le32_to_cpu(header
->h_refcount
) <
1615 EXT4_XATTR_REFCOUNT_MAX
;
1618 error
= mb_cache_entry_create(ext4_mb_cache
, GFP_NOFS
, hash
,
1619 bh
->b_blocknr
, reusable
);
1621 if (error
== -EBUSY
)
1622 ea_bdebug(bh
, "already in cache");
1624 ea_bdebug(bh
, "inserting [%x]", (int)hash
);
1630 * Compare two extended attribute blocks for equality.
1632 * Returns 0 if the blocks are equal, 1 if they differ, and
1633 * a negative error number on errors.
1636 ext4_xattr_cmp(struct ext4_xattr_header
*header1
,
1637 struct ext4_xattr_header
*header2
)
1639 struct ext4_xattr_entry
*entry1
, *entry2
;
1641 entry1
= ENTRY(header1
+1);
1642 entry2
= ENTRY(header2
+1);
1643 while (!IS_LAST_ENTRY(entry1
)) {
1644 if (IS_LAST_ENTRY(entry2
))
1646 if (entry1
->e_hash
!= entry2
->e_hash
||
1647 entry1
->e_name_index
!= entry2
->e_name_index
||
1648 entry1
->e_name_len
!= entry2
->e_name_len
||
1649 entry1
->e_value_size
!= entry2
->e_value_size
||
1650 memcmp(entry1
->e_name
, entry2
->e_name
, entry1
->e_name_len
))
1652 if (entry1
->e_value_block
!= 0 || entry2
->e_value_block
!= 0)
1653 return -EFSCORRUPTED
;
1654 if (memcmp((char *)header1
+ le16_to_cpu(entry1
->e_value_offs
),
1655 (char *)header2
+ le16_to_cpu(entry2
->e_value_offs
),
1656 le32_to_cpu(entry1
->e_value_size
)))
1659 entry1
= EXT4_XATTR_NEXT(entry1
);
1660 entry2
= EXT4_XATTR_NEXT(entry2
);
1662 if (!IS_LAST_ENTRY(entry2
))
1668 * ext4_xattr_cache_find()
1670 * Find an identical extended attribute block.
1672 * Returns a pointer to the block found, or NULL if such a block was
1673 * not found or an error occurred.
1675 static struct buffer_head
*
1676 ext4_xattr_cache_find(struct inode
*inode
, struct ext4_xattr_header
*header
,
1677 struct mb_cache_entry
**pce
)
1679 __u32 hash
= le32_to_cpu(header
->h_hash
);
1680 struct mb_cache_entry
*ce
;
1681 struct mb_cache
*ext4_mb_cache
= EXT4_GET_MB_CACHE(inode
);
1683 if (!header
->h_hash
)
1684 return NULL
; /* never share */
1685 ea_idebug(inode
, "looking for cached blocks [%x]", (int)hash
);
1686 ce
= mb_cache_entry_find_first(ext4_mb_cache
, hash
);
1688 struct buffer_head
*bh
;
1690 bh
= sb_bread(inode
->i_sb
, ce
->e_block
);
1692 EXT4_ERROR_INODE(inode
, "block %lu read error",
1693 (unsigned long) ce
->e_block
);
1694 } else if (ext4_xattr_cmp(header
, BHDR(bh
)) == 0) {
1699 ce
= mb_cache_entry_find_next(ext4_mb_cache
, ce
);
1704 #define NAME_HASH_SHIFT 5
1705 #define VALUE_HASH_SHIFT 16
1708 * ext4_xattr_hash_entry()
1710 * Compute the hash of an extended attribute.
1712 static inline void ext4_xattr_hash_entry(struct ext4_xattr_header
*header
,
1713 struct ext4_xattr_entry
*entry
)
1716 char *name
= entry
->e_name
;
1719 for (n
= 0; n
< entry
->e_name_len
; n
++) {
1720 hash
= (hash
<< NAME_HASH_SHIFT
) ^
1721 (hash
>> (8*sizeof(hash
) - NAME_HASH_SHIFT
)) ^
1725 if (entry
->e_value_size
!= 0) {
1726 __le32
*value
= (__le32
*)((char *)header
+
1727 le16_to_cpu(entry
->e_value_offs
));
1728 for (n
= (le32_to_cpu(entry
->e_value_size
) +
1729 EXT4_XATTR_ROUND
) >> EXT4_XATTR_PAD_BITS
; n
; n
--) {
1730 hash
= (hash
<< VALUE_HASH_SHIFT
) ^
1731 (hash
>> (8*sizeof(hash
) - VALUE_HASH_SHIFT
)) ^
1732 le32_to_cpu(*value
++);
1735 entry
->e_hash
= cpu_to_le32(hash
);
1738 #undef NAME_HASH_SHIFT
1739 #undef VALUE_HASH_SHIFT
1741 #define BLOCK_HASH_SHIFT 16
1744 * ext4_xattr_rehash()
1746 * Re-compute the extended attribute hash value after an entry has changed.
1748 static void ext4_xattr_rehash(struct ext4_xattr_header
*header
,
1749 struct ext4_xattr_entry
*entry
)
1751 struct ext4_xattr_entry
*here
;
1754 ext4_xattr_hash_entry(header
, entry
);
1755 here
= ENTRY(header
+1);
1756 while (!IS_LAST_ENTRY(here
)) {
1757 if (!here
->e_hash
) {
1758 /* Block is not shared if an entry's hash value == 0 */
1762 hash
= (hash
<< BLOCK_HASH_SHIFT
) ^
1763 (hash
>> (8*sizeof(hash
) - BLOCK_HASH_SHIFT
)) ^
1764 le32_to_cpu(here
->e_hash
);
1765 here
= EXT4_XATTR_NEXT(here
);
1767 header
->h_hash
= cpu_to_le32(hash
);
1770 #undef BLOCK_HASH_SHIFT
1772 #define HASH_BUCKET_BITS 10
1775 ext4_xattr_create_cache(void)
1777 return mb_cache_create(HASH_BUCKET_BITS
);
1780 void ext4_xattr_destroy_cache(struct mb_cache
*cache
)
1783 mb_cache_destroy(cache
);