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 WARN_ON_ONCE(dquot_initialize_needed(inode
));
893 /* The old block is released after updating
895 error
= dquot_alloc_block(inode
,
896 EXT4_C2B(EXT4_SB(sb
), 1));
899 BUFFER_TRACE(new_bh
, "get_write_access");
900 error
= ext4_journal_get_write_access(handle
,
906 * We have to be careful about races with
907 * freeing, rehashing or adding references to
908 * xattr block. Once we hold buffer lock xattr
909 * block's state is stable so we can check
910 * whether the block got freed / rehashed or
911 * not. Since we unhash mbcache entry under
912 * buffer lock when freeing / rehashing xattr
913 * block, checking whether entry is still
914 * hashed is reliable. Same rules hold for
915 * e_reusable handling.
917 if (hlist_bl_unhashed(&ce
->e_hash_list
) ||
920 * Undo everything and check mbcache
923 unlock_buffer(new_bh
);
924 dquot_free_block(inode
,
925 EXT4_C2B(EXT4_SB(sb
),
928 mb_cache_entry_put(ext4_mb_cache
, ce
);
933 ref
= le32_to_cpu(BHDR(new_bh
)->h_refcount
) + 1;
934 BHDR(new_bh
)->h_refcount
= cpu_to_le32(ref
);
935 if (ref
>= EXT4_XATTR_REFCOUNT_MAX
)
937 ea_bdebug(new_bh
, "reusing; refcount now=%d",
939 ext4_xattr_block_csum_set(inode
, new_bh
);
940 unlock_buffer(new_bh
);
941 error
= ext4_handle_dirty_metadata(handle
,
947 mb_cache_entry_touch(ext4_mb_cache
, ce
);
948 mb_cache_entry_put(ext4_mb_cache
, ce
);
950 } else if (bs
->bh
&& s
->base
== bs
->bh
->b_data
) {
951 /* We were modifying this block in-place. */
952 ea_bdebug(bs
->bh
, "keeping this block");
956 /* We need to allocate a new block */
957 ext4_fsblk_t goal
, block
;
959 WARN_ON_ONCE(dquot_initialize_needed(inode
));
961 goal
= ext4_group_first_block_no(sb
,
962 EXT4_I(inode
)->i_block_group
);
964 /* non-extent files can't have physical blocks past 2^32 */
965 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)))
966 goal
= goal
& EXT4_MAX_BLOCK_FILE_PHYS
;
968 block
= ext4_new_meta_blocks(handle
, inode
, goal
, 0,
973 if (!(ext4_test_inode_flag(inode
, EXT4_INODE_EXTENTS
)))
974 BUG_ON(block
> EXT4_MAX_BLOCK_FILE_PHYS
);
976 ea_idebug(inode
, "creating block %llu",
977 (unsigned long long)block
);
979 new_bh
= sb_getblk(sb
, block
);
980 if (unlikely(!new_bh
)) {
983 ext4_free_blocks(handle
, inode
, NULL
, block
, 1,
984 EXT4_FREE_BLOCKS_METADATA
);
988 error
= ext4_journal_get_create_access(handle
, new_bh
);
990 unlock_buffer(new_bh
);
994 memcpy(new_bh
->b_data
, s
->base
, new_bh
->b_size
);
995 ext4_xattr_block_csum_set(inode
, new_bh
);
996 set_buffer_uptodate(new_bh
);
997 unlock_buffer(new_bh
);
998 ext4_xattr_cache_insert(ext4_mb_cache
, new_bh
);
999 error
= ext4_handle_dirty_metadata(handle
, inode
,
1006 /* Update the inode. */
1007 EXT4_I(inode
)->i_file_acl
= new_bh
? new_bh
->b_blocknr
: 0;
1009 /* Drop the previous xattr block. */
1010 if (bs
->bh
&& bs
->bh
!= new_bh
)
1011 ext4_xattr_release_block(handle
, inode
, bs
->bh
);
1016 mb_cache_entry_put(ext4_mb_cache
, ce
);
1018 if (!(bs
->bh
&& s
->base
== bs
->bh
->b_data
))
1024 dquot_free_block(inode
, EXT4_C2B(EXT4_SB(sb
), 1));
1028 EXT4_ERROR_INODE(inode
, "bad block %llu",
1029 EXT4_I(inode
)->i_file_acl
);
1035 int ext4_xattr_ibody_find(struct inode
*inode
, struct ext4_xattr_info
*i
,
1036 struct ext4_xattr_ibody_find
*is
)
1038 struct ext4_xattr_ibody_header
*header
;
1039 struct ext4_inode
*raw_inode
;
1042 if (EXT4_I(inode
)->i_extra_isize
== 0)
1044 raw_inode
= ext4_raw_inode(&is
->iloc
);
1045 header
= IHDR(inode
, raw_inode
);
1046 is
->s
.base
= is
->s
.first
= IFIRST(header
);
1047 is
->s
.here
= is
->s
.first
;
1048 is
->s
.end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
1049 if (ext4_test_inode_state(inode
, EXT4_STATE_XATTR
)) {
1050 error
= xattr_check_inode(inode
, header
, is
->s
.end
);
1053 /* Find the named attribute. */
1054 error
= ext4_xattr_find_entry(&is
->s
.here
, i
->name_index
,
1056 if (error
&& error
!= -ENODATA
)
1058 is
->s
.not_found
= error
;
1063 int ext4_xattr_ibody_inline_set(handle_t
*handle
, struct inode
*inode
,
1064 struct ext4_xattr_info
*i
,
1065 struct ext4_xattr_ibody_find
*is
)
1067 struct ext4_xattr_ibody_header
*header
;
1068 struct ext4_xattr_search
*s
= &is
->s
;
1071 if (EXT4_I(inode
)->i_extra_isize
== 0)
1073 error
= ext4_xattr_set_entry(i
, s
);
1075 if (error
== -ENOSPC
&&
1076 ext4_has_inline_data(inode
)) {
1077 error
= ext4_try_to_evict_inline_data(handle
, inode
,
1078 EXT4_XATTR_LEN(strlen(i
->name
) +
1079 EXT4_XATTR_SIZE(i
->value_len
)));
1082 error
= ext4_xattr_ibody_find(inode
, i
, is
);
1085 error
= ext4_xattr_set_entry(i
, s
);
1090 header
= IHDR(inode
, ext4_raw_inode(&is
->iloc
));
1091 if (!IS_LAST_ENTRY(s
->first
)) {
1092 header
->h_magic
= cpu_to_le32(EXT4_XATTR_MAGIC
);
1093 ext4_set_inode_state(inode
, EXT4_STATE_XATTR
);
1095 header
->h_magic
= cpu_to_le32(0);
1096 ext4_clear_inode_state(inode
, EXT4_STATE_XATTR
);
1101 static int ext4_xattr_ibody_set(struct inode
*inode
,
1102 struct ext4_xattr_info
*i
,
1103 struct ext4_xattr_ibody_find
*is
)
1105 struct ext4_xattr_ibody_header
*header
;
1106 struct ext4_xattr_search
*s
= &is
->s
;
1109 if (EXT4_I(inode
)->i_extra_isize
== 0)
1111 error
= ext4_xattr_set_entry(i
, s
);
1114 header
= IHDR(inode
, ext4_raw_inode(&is
->iloc
));
1115 if (!IS_LAST_ENTRY(s
->first
)) {
1116 header
->h_magic
= cpu_to_le32(EXT4_XATTR_MAGIC
);
1117 ext4_set_inode_state(inode
, EXT4_STATE_XATTR
);
1119 header
->h_magic
= cpu_to_le32(0);
1120 ext4_clear_inode_state(inode
, EXT4_STATE_XATTR
);
1125 static int ext4_xattr_value_same(struct ext4_xattr_search
*s
,
1126 struct ext4_xattr_info
*i
)
1130 if (le32_to_cpu(s
->here
->e_value_size
) != i
->value_len
)
1132 value
= ((void *)s
->base
) + le16_to_cpu(s
->here
->e_value_offs
);
1133 return !memcmp(value
, i
->value
, i
->value_len
);
1137 * ext4_xattr_set_handle()
1139 * Create, replace or remove an extended attribute for this inode. Value
1140 * is NULL to remove an existing extended attribute, and non-NULL to
1141 * either replace an existing extended attribute, or create a new extended
1142 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
1143 * specify that an extended attribute must exist and must not exist
1144 * previous to the call, respectively.
1146 * Returns 0, or a negative error number on failure.
1149 ext4_xattr_set_handle(handle_t
*handle
, struct inode
*inode
, int name_index
,
1150 const char *name
, const void *value
, size_t value_len
,
1153 struct ext4_xattr_info i
= {
1154 .name_index
= name_index
,
1157 .value_len
= value_len
,
1160 struct ext4_xattr_ibody_find is
= {
1161 .s
= { .not_found
= -ENODATA
, },
1163 struct ext4_xattr_block_find bs
= {
1164 .s
= { .not_found
= -ENODATA
, },
1171 if (strlen(name
) > 255)
1174 ext4_write_lock_xattr(inode
, &no_expand
);
1176 error
= ext4_reserve_inode_write(handle
, inode
, &is
.iloc
);
1180 if (ext4_test_inode_state(inode
, EXT4_STATE_NEW
)) {
1181 struct ext4_inode
*raw_inode
= ext4_raw_inode(&is
.iloc
);
1182 memset(raw_inode
, 0, EXT4_SB(inode
->i_sb
)->s_inode_size
);
1183 ext4_clear_inode_state(inode
, EXT4_STATE_NEW
);
1186 error
= ext4_xattr_ibody_find(inode
, &i
, &is
);
1190 error
= ext4_xattr_block_find(inode
, &i
, &bs
);
1193 if (is
.s
.not_found
&& bs
.s
.not_found
) {
1195 if (flags
& XATTR_REPLACE
)
1202 if (flags
& XATTR_CREATE
)
1206 if (!is
.s
.not_found
)
1207 error
= ext4_xattr_ibody_set(inode
, &i
, &is
);
1208 else if (!bs
.s
.not_found
)
1209 error
= ext4_xattr_block_set(handle
, inode
, &i
, &bs
);
1212 /* Xattr value did not change? Save us some work and bail out */
1213 if (!is
.s
.not_found
&& ext4_xattr_value_same(&is
.s
, &i
))
1215 if (!bs
.s
.not_found
&& ext4_xattr_value_same(&bs
.s
, &i
))
1218 error
= ext4_xattr_ibody_set(inode
, &i
, &is
);
1219 if (!error
&& !bs
.s
.not_found
) {
1221 error
= ext4_xattr_block_set(handle
, inode
, &i
, &bs
);
1222 } else if (error
== -ENOSPC
) {
1223 if (EXT4_I(inode
)->i_file_acl
&& !bs
.s
.base
) {
1224 error
= ext4_xattr_block_find(inode
, &i
, &bs
);
1228 error
= ext4_xattr_block_set(handle
, inode
, &i
, &bs
);
1231 if (!is
.s
.not_found
) {
1233 error
= ext4_xattr_ibody_set(inode
, &i
, &is
);
1238 ext4_xattr_update_super_block(handle
, inode
->i_sb
);
1239 inode
->i_ctime
= current_time(inode
);
1242 error
= ext4_mark_iloc_dirty(handle
, inode
, &is
.iloc
);
1244 * The bh is consumed by ext4_mark_iloc_dirty, even with
1249 ext4_handle_sync(handle
);
1255 ext4_write_unlock_xattr(inode
, &no_expand
);
1262 * Like ext4_xattr_set_handle, but start from an inode. This extended
1263 * attribute modification is a filesystem transaction by itself.
1265 * Returns 0, or a negative error number on failure.
1268 ext4_xattr_set(struct inode
*inode
, int name_index
, const char *name
,
1269 const void *value
, size_t value_len
, int flags
)
1272 int error
, retries
= 0;
1273 int credits
= ext4_jbd2_credits_xattr(inode
);
1275 error
= dquot_initialize(inode
);
1279 handle
= ext4_journal_start(inode
, EXT4_HT_XATTR
, credits
);
1280 if (IS_ERR(handle
)) {
1281 error
= PTR_ERR(handle
);
1285 error
= ext4_xattr_set_handle(handle
, inode
, name_index
, name
,
1286 value
, value_len
, flags
);
1287 error2
= ext4_journal_stop(handle
);
1288 if (error
== -ENOSPC
&&
1289 ext4_should_retry_alloc(inode
->i_sb
, &retries
))
1299 * Shift the EA entries in the inode to create space for the increased
1302 static void ext4_xattr_shift_entries(struct ext4_xattr_entry
*entry
,
1303 int value_offs_shift
, void *to
,
1304 void *from
, size_t n
)
1306 struct ext4_xattr_entry
*last
= entry
;
1309 /* We always shift xattr headers further thus offsets get lower */
1310 BUG_ON(value_offs_shift
> 0);
1312 /* Adjust the value offsets of the entries */
1313 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
1314 if (last
->e_value_size
) {
1315 new_offs
= le16_to_cpu(last
->e_value_offs
) +
1317 last
->e_value_offs
= cpu_to_le16(new_offs
);
1320 /* Shift the entries by n bytes */
1321 memmove(to
, from
, n
);
1325 * Move xattr pointed to by 'entry' from inode into external xattr block
1327 static int ext4_xattr_move_to_block(handle_t
*handle
, struct inode
*inode
,
1328 struct ext4_inode
*raw_inode
,
1329 struct ext4_xattr_entry
*entry
)
1331 struct ext4_xattr_ibody_find
*is
= NULL
;
1332 struct ext4_xattr_block_find
*bs
= NULL
;
1333 char *buffer
= NULL
, *b_entry_name
= NULL
;
1334 size_t value_offs
, value_size
;
1335 struct ext4_xattr_info i
= {
1338 .name_index
= entry
->e_name_index
,
1340 struct ext4_xattr_ibody_header
*header
= IHDR(inode
, raw_inode
);
1343 value_offs
= le16_to_cpu(entry
->e_value_offs
);
1344 value_size
= le32_to_cpu(entry
->e_value_size
);
1346 is
= kzalloc(sizeof(struct ext4_xattr_ibody_find
), GFP_NOFS
);
1347 bs
= kzalloc(sizeof(struct ext4_xattr_block_find
), GFP_NOFS
);
1348 buffer
= kmalloc(value_size
, GFP_NOFS
);
1349 b_entry_name
= kmalloc(entry
->e_name_len
+ 1, GFP_NOFS
);
1350 if (!is
|| !bs
|| !buffer
|| !b_entry_name
) {
1355 is
->s
.not_found
= -ENODATA
;
1356 bs
->s
.not_found
= -ENODATA
;
1360 /* Save the entry name and the entry value */
1361 memcpy(buffer
, (void *)IFIRST(header
) + value_offs
, value_size
);
1362 memcpy(b_entry_name
, entry
->e_name
, entry
->e_name_len
);
1363 b_entry_name
[entry
->e_name_len
] = '\0';
1364 i
.name
= b_entry_name
;
1366 error
= ext4_get_inode_loc(inode
, &is
->iloc
);
1370 error
= ext4_xattr_ibody_find(inode
, &i
, is
);
1374 /* Remove the chosen entry from the inode */
1375 error
= ext4_xattr_ibody_set(inode
, &i
, is
);
1379 i
.name
= b_entry_name
;
1381 i
.value_len
= value_size
;
1382 error
= ext4_xattr_block_find(inode
, &i
, bs
);
1386 /* Add entry which was removed from the inode into the block */
1387 error
= ext4_xattr_block_set(handle
, inode
, &i
, bs
);
1392 kfree(b_entry_name
);
1395 brelse(is
->iloc
.bh
);
1402 static int ext4_xattr_make_inode_space(handle_t
*handle
, struct inode
*inode
,
1403 struct ext4_inode
*raw_inode
,
1404 int isize_diff
, size_t ifree
,
1405 size_t bfree
, int *total_ino
)
1407 struct ext4_xattr_ibody_header
*header
= IHDR(inode
, raw_inode
);
1408 struct ext4_xattr_entry
*small_entry
;
1409 struct ext4_xattr_entry
*entry
;
1410 struct ext4_xattr_entry
*last
;
1411 unsigned int entry_size
; /* EA entry size */
1412 unsigned int total_size
; /* EA entry size + value size */
1413 unsigned int min_total_size
;
1416 while (isize_diff
> ifree
) {
1419 min_total_size
= ~0U;
1420 last
= IFIRST(header
);
1421 /* Find the entry best suited to be pushed into EA block */
1422 for (; !IS_LAST_ENTRY(last
); last
= EXT4_XATTR_NEXT(last
)) {
1424 EXT4_XATTR_SIZE(le32_to_cpu(last
->e_value_size
)) +
1425 EXT4_XATTR_LEN(last
->e_name_len
);
1426 if (total_size
<= bfree
&&
1427 total_size
< min_total_size
) {
1428 if (total_size
+ ifree
< isize_diff
) {
1432 min_total_size
= total_size
;
1437 if (entry
== NULL
) {
1438 if (small_entry
== NULL
)
1440 entry
= small_entry
;
1443 entry_size
= EXT4_XATTR_LEN(entry
->e_name_len
);
1444 total_size
= entry_size
+
1445 EXT4_XATTR_SIZE(le32_to_cpu(entry
->e_value_size
));
1446 error
= ext4_xattr_move_to_block(handle
, inode
, raw_inode
,
1451 *total_ino
-= entry_size
;
1452 ifree
+= total_size
;
1453 bfree
-= total_size
;
1460 * Expand an inode by new_extra_isize bytes when EAs are present.
1461 * Returns 0 on success or negative error number on failure.
1463 int ext4_expand_extra_isize_ea(struct inode
*inode
, int new_extra_isize
,
1464 struct ext4_inode
*raw_inode
, handle_t
*handle
)
1466 struct ext4_xattr_ibody_header
*header
;
1467 struct buffer_head
*bh
= NULL
;
1469 size_t ifree
, bfree
;
1472 int error
= 0, tried_min_extra_isize
= 0;
1473 int s_min_extra_isize
= le16_to_cpu(EXT4_SB(inode
->i_sb
)->s_es
->s_min_extra_isize
);
1474 int isize_diff
; /* How much do we need to grow i_extra_isize */
1477 if (ext4_write_trylock_xattr(inode
, &no_expand
) == 0)
1481 isize_diff
= new_extra_isize
- EXT4_I(inode
)->i_extra_isize
;
1482 if (EXT4_I(inode
)->i_extra_isize
>= new_extra_isize
)
1485 header
= IHDR(inode
, raw_inode
);
1488 * Check if enough free space is available in the inode to shift the
1489 * entries ahead by new_extra_isize.
1492 base
= IFIRST(header
);
1493 end
= (void *)raw_inode
+ EXT4_SB(inode
->i_sb
)->s_inode_size
;
1494 min_offs
= end
- base
;
1495 total_ino
= sizeof(struct ext4_xattr_ibody_header
);
1497 error
= xattr_check_inode(inode
, header
, end
);
1501 ifree
= ext4_xattr_free_space(base
, &min_offs
, base
, &total_ino
);
1502 if (ifree
>= isize_diff
)
1506 * Enough free space isn't available in the inode, check if
1507 * EA block can hold new_extra_isize bytes.
1509 if (EXT4_I(inode
)->i_file_acl
) {
1510 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
1514 if (ext4_xattr_check_block(inode
, bh
)) {
1515 EXT4_ERROR_INODE(inode
, "bad block %llu",
1516 EXT4_I(inode
)->i_file_acl
);
1517 error
= -EFSCORRUPTED
;
1521 end
= bh
->b_data
+ bh
->b_size
;
1522 min_offs
= end
- base
;
1523 bfree
= ext4_xattr_free_space(BFIRST(bh
), &min_offs
, base
,
1525 if (bfree
+ ifree
< isize_diff
) {
1526 if (!tried_min_extra_isize
&& s_min_extra_isize
) {
1527 tried_min_extra_isize
++;
1528 new_extra_isize
= s_min_extra_isize
;
1536 bfree
= inode
->i_sb
->s_blocksize
;
1539 error
= ext4_xattr_make_inode_space(handle
, inode
, raw_inode
,
1540 isize_diff
, ifree
, bfree
,
1543 if (error
== -ENOSPC
&& !tried_min_extra_isize
&&
1544 s_min_extra_isize
) {
1545 tried_min_extra_isize
++;
1546 new_extra_isize
= s_min_extra_isize
;
1553 /* Adjust the offsets and shift the remaining entries ahead */
1554 ext4_xattr_shift_entries(IFIRST(header
), EXT4_I(inode
)->i_extra_isize
1555 - new_extra_isize
, (void *)raw_inode
+
1556 EXT4_GOOD_OLD_INODE_SIZE
+ new_extra_isize
,
1557 (void *)header
, total_ino
);
1558 EXT4_I(inode
)->i_extra_isize
= new_extra_isize
;
1561 ext4_write_unlock_xattr(inode
, &no_expand
);
1567 * Inode size expansion failed; don't try again
1570 ext4_write_unlock_xattr(inode
, &no_expand
);
1577 * ext4_xattr_delete_inode()
1579 * Free extended attribute resources associated with this inode. This
1580 * is called immediately before an inode is freed. We have exclusive
1581 * access to the inode.
1584 ext4_xattr_delete_inode(handle_t
*handle
, struct inode
*inode
)
1586 struct buffer_head
*bh
= NULL
;
1588 if (!EXT4_I(inode
)->i_file_acl
)
1590 bh
= sb_bread(inode
->i_sb
, EXT4_I(inode
)->i_file_acl
);
1592 EXT4_ERROR_INODE(inode
, "block %llu read error",
1593 EXT4_I(inode
)->i_file_acl
);
1596 if (BHDR(bh
)->h_magic
!= cpu_to_le32(EXT4_XATTR_MAGIC
) ||
1597 BHDR(bh
)->h_blocks
!= cpu_to_le32(1)) {
1598 EXT4_ERROR_INODE(inode
, "bad block %llu",
1599 EXT4_I(inode
)->i_file_acl
);
1602 ext4_xattr_release_block(handle
, inode
, bh
);
1603 EXT4_I(inode
)->i_file_acl
= 0;
1610 * ext4_xattr_cache_insert()
1612 * Create a new entry in the extended attribute cache, and insert
1613 * it unless such an entry is already in the cache.
1615 * Returns 0, or a negative error number on failure.
1618 ext4_xattr_cache_insert(struct mb_cache
*ext4_mb_cache
, struct buffer_head
*bh
)
1620 struct ext4_xattr_header
*header
= BHDR(bh
);
1621 __u32 hash
= le32_to_cpu(header
->h_hash
);
1622 int reusable
= le32_to_cpu(header
->h_refcount
) <
1623 EXT4_XATTR_REFCOUNT_MAX
;
1626 error
= mb_cache_entry_create(ext4_mb_cache
, GFP_NOFS
, hash
,
1627 bh
->b_blocknr
, reusable
);
1629 if (error
== -EBUSY
)
1630 ea_bdebug(bh
, "already in cache");
1632 ea_bdebug(bh
, "inserting [%x]", (int)hash
);
1638 * Compare two extended attribute blocks for equality.
1640 * Returns 0 if the blocks are equal, 1 if they differ, and
1641 * a negative error number on errors.
1644 ext4_xattr_cmp(struct ext4_xattr_header
*header1
,
1645 struct ext4_xattr_header
*header2
)
1647 struct ext4_xattr_entry
*entry1
, *entry2
;
1649 entry1
= ENTRY(header1
+1);
1650 entry2
= ENTRY(header2
+1);
1651 while (!IS_LAST_ENTRY(entry1
)) {
1652 if (IS_LAST_ENTRY(entry2
))
1654 if (entry1
->e_hash
!= entry2
->e_hash
||
1655 entry1
->e_name_index
!= entry2
->e_name_index
||
1656 entry1
->e_name_len
!= entry2
->e_name_len
||
1657 entry1
->e_value_size
!= entry2
->e_value_size
||
1658 memcmp(entry1
->e_name
, entry2
->e_name
, entry1
->e_name_len
))
1660 if (entry1
->e_value_block
!= 0 || entry2
->e_value_block
!= 0)
1661 return -EFSCORRUPTED
;
1662 if (memcmp((char *)header1
+ le16_to_cpu(entry1
->e_value_offs
),
1663 (char *)header2
+ le16_to_cpu(entry2
->e_value_offs
),
1664 le32_to_cpu(entry1
->e_value_size
)))
1667 entry1
= EXT4_XATTR_NEXT(entry1
);
1668 entry2
= EXT4_XATTR_NEXT(entry2
);
1670 if (!IS_LAST_ENTRY(entry2
))
1676 * ext4_xattr_cache_find()
1678 * Find an identical extended attribute block.
1680 * Returns a pointer to the block found, or NULL if such a block was
1681 * not found or an error occurred.
1683 static struct buffer_head
*
1684 ext4_xattr_cache_find(struct inode
*inode
, struct ext4_xattr_header
*header
,
1685 struct mb_cache_entry
**pce
)
1687 __u32 hash
= le32_to_cpu(header
->h_hash
);
1688 struct mb_cache_entry
*ce
;
1689 struct mb_cache
*ext4_mb_cache
= EXT4_GET_MB_CACHE(inode
);
1691 if (!header
->h_hash
)
1692 return NULL
; /* never share */
1693 ea_idebug(inode
, "looking for cached blocks [%x]", (int)hash
);
1694 ce
= mb_cache_entry_find_first(ext4_mb_cache
, hash
);
1696 struct buffer_head
*bh
;
1698 bh
= sb_bread(inode
->i_sb
, ce
->e_block
);
1700 EXT4_ERROR_INODE(inode
, "block %lu read error",
1701 (unsigned long) ce
->e_block
);
1702 } else if (ext4_xattr_cmp(header
, BHDR(bh
)) == 0) {
1707 ce
= mb_cache_entry_find_next(ext4_mb_cache
, ce
);
1712 #define NAME_HASH_SHIFT 5
1713 #define VALUE_HASH_SHIFT 16
1716 * ext4_xattr_hash_entry()
1718 * Compute the hash of an extended attribute.
1720 static inline void ext4_xattr_hash_entry(struct ext4_xattr_header
*header
,
1721 struct ext4_xattr_entry
*entry
)
1724 char *name
= entry
->e_name
;
1727 for (n
= 0; n
< entry
->e_name_len
; n
++) {
1728 hash
= (hash
<< NAME_HASH_SHIFT
) ^
1729 (hash
>> (8*sizeof(hash
) - NAME_HASH_SHIFT
)) ^
1733 if (entry
->e_value_size
!= 0) {
1734 __le32
*value
= (__le32
*)((char *)header
+
1735 le16_to_cpu(entry
->e_value_offs
));
1736 for (n
= (le32_to_cpu(entry
->e_value_size
) +
1737 EXT4_XATTR_ROUND
) >> EXT4_XATTR_PAD_BITS
; n
; n
--) {
1738 hash
= (hash
<< VALUE_HASH_SHIFT
) ^
1739 (hash
>> (8*sizeof(hash
) - VALUE_HASH_SHIFT
)) ^
1740 le32_to_cpu(*value
++);
1743 entry
->e_hash
= cpu_to_le32(hash
);
1746 #undef NAME_HASH_SHIFT
1747 #undef VALUE_HASH_SHIFT
1749 #define BLOCK_HASH_SHIFT 16
1752 * ext4_xattr_rehash()
1754 * Re-compute the extended attribute hash value after an entry has changed.
1756 static void ext4_xattr_rehash(struct ext4_xattr_header
*header
,
1757 struct ext4_xattr_entry
*entry
)
1759 struct ext4_xattr_entry
*here
;
1762 ext4_xattr_hash_entry(header
, entry
);
1763 here
= ENTRY(header
+1);
1764 while (!IS_LAST_ENTRY(here
)) {
1765 if (!here
->e_hash
) {
1766 /* Block is not shared if an entry's hash value == 0 */
1770 hash
= (hash
<< BLOCK_HASH_SHIFT
) ^
1771 (hash
>> (8*sizeof(hash
) - BLOCK_HASH_SHIFT
)) ^
1772 le32_to_cpu(here
->e_hash
);
1773 here
= EXT4_XATTR_NEXT(here
);
1775 header
->h_hash
= cpu_to_le32(hash
);
1778 #undef BLOCK_HASH_SHIFT
1780 #define HASH_BUCKET_BITS 10
1783 ext4_xattr_create_cache(void)
1785 return mb_cache_create(HASH_BUCKET_BITS
);
1788 void ext4_xattr_destroy_cache(struct mb_cache
*cache
)
1791 mb_cache_destroy(cache
);