2 * linux/fs/ext3/xattr.c
4 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
6 * Fix by Harrison Xing <harrison@mountainviewdata.com>.
7 * Ext3 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 * EXT3_I(inode)->i_file_acl is protected by EXT3_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/ext3_jbd.h>
57 #include <linux/ext3_fs.h>
58 #include <linux/mbcache.h>
59 #include <linux/quotaops.h>
60 #include <linux/rwsem.h>
64 #define BHDR(bh) ((struct ext3_xattr_header *)((bh)->b_data))
65 #define ENTRY(ptr) ((struct ext3_xattr_entry *)(ptr))
66 #define BFIRST(bh) ENTRY(BHDR(bh)+1)
67 #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
69 #define IHDR(inode, raw_inode) \
70 ((struct ext3_xattr_ibody_header *) \
71 ((void *)raw_inode + \
72 EXT3_GOOD_OLD_INODE_SIZE + \
73 EXT3_I(inode)->i_extra_isize))
74 #define IFIRST(hdr) ((struct ext3_xattr_entry *)((hdr)+1))
76 #ifdef EXT3_XATTR_DEBUG
77 # define ea_idebug(inode, f...) do { \
78 printk(KERN_DEBUG "inode %s:%lu: ", \
79 inode->i_sb->s_id, inode->i_ino); \
83 # define ea_bdebug(bh, f...) do { \
84 char b[BDEVNAME_SIZE]; \
85 printk(KERN_DEBUG "block %s:%lu: ", \
86 bdevname(bh->b_bdev, b), \
87 (unsigned long) bh->b_blocknr); \
92 # define ea_idebug(f...)
93 # define ea_bdebug(f...)
96 static void ext3_xattr_cache_insert(struct buffer_head
*);
97 static struct buffer_head
*ext3_xattr_cache_find(struct inode
*,
98 struct ext3_xattr_header
*,
99 struct mb_cache_entry
**);
100 static void ext3_xattr_rehash(struct ext3_xattr_header
*,
101 struct ext3_xattr_entry
*);
102 static int ext3_xattr_list(struct dentry
*dentry
, char *buffer
,
105 static struct mb_cache
*ext3_xattr_cache
;
107 static const struct xattr_handler
*ext3_xattr_handler_map
[] = {
108 [EXT3_XATTR_INDEX_USER
] = &ext3_xattr_user_handler
,
109 #ifdef CONFIG_EXT3_FS_POSIX_ACL
110 [EXT3_XATTR_INDEX_POSIX_ACL_ACCESS
] = &ext3_xattr_acl_access_handler
,
111 [EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT
] = &ext3_xattr_acl_default_handler
,
113 [EXT3_XATTR_INDEX_TRUSTED
] = &ext3_xattr_trusted_handler
,
114 #ifdef CONFIG_EXT3_FS_SECURITY
115 [EXT3_XATTR_INDEX_SECURITY
] = &ext3_xattr_security_handler
,
119 const struct xattr_handler
*ext3_xattr_handlers
[] = {
120 &ext3_xattr_user_handler
,
121 &ext3_xattr_trusted_handler
,
122 #ifdef CONFIG_EXT3_FS_POSIX_ACL
123 &ext3_xattr_acl_access_handler
,
124 &ext3_xattr_acl_default_handler
,
126 #ifdef CONFIG_EXT3_FS_SECURITY
127 &ext3_xattr_security_handler
,
132 static inline const struct xattr_handler
*
133 ext3_xattr_handler(int name_index
)
135 const struct xattr_handler
*handler
= NULL
;
137 if (name_index
> 0 && name_index
< ARRAY_SIZE(ext3_xattr_handler_map
))
138 handler
= ext3_xattr_handler_map
[name_index
];
143 * Inode operation listxattr()
145 * dentry->d_inode->i_mutex: don't care
148 ext3_listxattr(struct dentry
*dentry
, char *buffer
, size_t size
)
150 return ext3_xattr_list(dentry
, buffer
, size
);
154 ext3_xattr_check_names(struct ext3_xattr_entry
*entry
, void *end
)
156 while (!IS_LAST_ENTRY(entry
)) {
157 struct ext3_xattr_entry
*next
= EXT3_XATTR_NEXT(entry
);
158 if ((void *)next
>= end
)
166 ext3_xattr_check_block(struct buffer_head
*bh
)
170 if (BHDR(bh
)->h_magic
!= cpu_to_le32(EXT3_XATTR_MAGIC
) ||
171 BHDR(bh
)->h_blocks
!= cpu_to_le32(1))
173 error
= ext3_xattr_check_names(BFIRST(bh
), bh
->b_data
+ bh
->b_size
);
178 ext3_xattr_check_entry(struct ext3_xattr_entry
*entry
, size_t size
)
180 size_t value_size
= le32_to_cpu(entry
->e_value_size
);
182 if (entry
->e_value_block
!= 0 || value_size
> size
||
183 le16_to_cpu(entry
->e_value_offs
) + value_size
> size
)
189 ext3_xattr_find_entry(struct ext3_xattr_entry
**pentry
, int name_index
,
190 const char *name
, size_t size
, int sorted
)
192 struct ext3_xattr_entry
*entry
;
198 name_len
= strlen(name
);
200 for (; !IS_LAST_ENTRY(entry
); entry
= EXT3_XATTR_NEXT(entry
)) {
201 cmp
= name_index
- entry
->e_name_index
;
203 cmp
= name_len
- entry
->e_name_len
;
205 cmp
= memcmp(name
, entry
->e_name
, name_len
);
206 if (cmp
<= 0 && (sorted
|| cmp
== 0))
210 if (!cmp
&& ext3_xattr_check_entry(entry
, size
))
212 return cmp
? -ENODATA
: 0;
216 ext3_xattr_block_get(struct inode
*inode
, int name_index
, const char *name
,
217 void *buffer
, size_t buffer_size
)
219 struct buffer_head
*bh
= NULL
;
220 struct ext3_xattr_entry
*entry
;
224 ea_idebug(inode
, "name=%d.%s, buffer=%p, buffer_size=%ld",
225 name_index
, name
, buffer
, (long)buffer_size
);
228 if (!EXT3_I(inode
)->i_file_acl
)
230 ea_idebug(inode
, "reading block %u", EXT3_I(inode
)->i_file_acl
);
231 bh
= sb_bread(inode
->i_sb
, EXT3_I(inode
)->i_file_acl
);
234 ea_bdebug(bh
, "b_count=%d, refcount=%d",
235 atomic_read(&(bh
->b_count
)), le32_to_cpu(BHDR(bh
)->h_refcount
));
236 if (ext3_xattr_check_block(bh
)) {
237 bad_block
: ext3_error(inode
->i_sb
, __func__
,
238 "inode %lu: bad block "E3FSBLK
, inode
->i_ino
,
239 EXT3_I(inode
)->i_file_acl
);
243 ext3_xattr_cache_insert(bh
);
245 error
= ext3_xattr_find_entry(&entry
, name_index
, name
, bh
->b_size
, 1);
250 size
= le32_to_cpu(entry
->e_value_size
);
253 if (size
> buffer_size
)
255 memcpy(buffer
, bh
->b_data
+ le16_to_cpu(entry
->e_value_offs
),
266 ext3_xattr_ibody_get(struct inode
*inode
, int name_index
, const char *name
,
267 void *buffer
, size_t buffer_size
)
269 struct ext3_xattr_ibody_header
*header
;
270 struct ext3_xattr_entry
*entry
;
271 struct ext3_inode
*raw_inode
;
272 struct ext3_iloc iloc
;
277 if (!ext3_test_inode_state(inode
, EXT3_STATE_XATTR
))
279 error
= ext3_get_inode_loc(inode
, &iloc
);
282 raw_inode
= ext3_raw_inode(&iloc
);
283 header
= IHDR(inode
, raw_inode
);
284 entry
= IFIRST(header
);
285 end
= (void *)raw_inode
+ EXT3_SB(inode
->i_sb
)->s_inode_size
;
286 error
= ext3_xattr_check_names(entry
, end
);
289 error
= ext3_xattr_find_entry(&entry
, name_index
, name
,
290 end
- (void *)entry
, 0);
293 size
= le32_to_cpu(entry
->e_value_size
);
296 if (size
> buffer_size
)
298 memcpy(buffer
, (void *)IFIRST(header
) +
299 le16_to_cpu(entry
->e_value_offs
), size
);
311 * Copy an extended attribute into the buffer
312 * provided, or compute the buffer size required.
313 * Buffer is NULL to compute the size of the buffer required.
315 * Returns a negative error number on failure, or the number of bytes
316 * used / required on success.
319 ext3_xattr_get(struct inode
*inode
, int name_index
, const char *name
,
320 void *buffer
, size_t buffer_size
)
324 down_read(&EXT3_I(inode
)->xattr_sem
);
325 error
= ext3_xattr_ibody_get(inode
, name_index
, name
, buffer
,
327 if (error
== -ENODATA
)
328 error
= ext3_xattr_block_get(inode
, name_index
, name
, buffer
,
330 up_read(&EXT3_I(inode
)->xattr_sem
);
335 ext3_xattr_list_entries(struct dentry
*dentry
, struct ext3_xattr_entry
*entry
,
336 char *buffer
, size_t buffer_size
)
338 size_t rest
= buffer_size
;
340 for (; !IS_LAST_ENTRY(entry
); entry
= EXT3_XATTR_NEXT(entry
)) {
341 const struct xattr_handler
*handler
=
342 ext3_xattr_handler(entry
->e_name_index
);
345 size_t size
= handler
->list(dentry
, buffer
, rest
,
357 return buffer_size
- rest
;
361 ext3_xattr_block_list(struct dentry
*dentry
, char *buffer
, size_t buffer_size
)
363 struct inode
*inode
= dentry
->d_inode
;
364 struct buffer_head
*bh
= NULL
;
367 ea_idebug(inode
, "buffer=%p, buffer_size=%ld",
368 buffer
, (long)buffer_size
);
371 if (!EXT3_I(inode
)->i_file_acl
)
373 ea_idebug(inode
, "reading block %u", EXT3_I(inode
)->i_file_acl
);
374 bh
= sb_bread(inode
->i_sb
, EXT3_I(inode
)->i_file_acl
);
378 ea_bdebug(bh
, "b_count=%d, refcount=%d",
379 atomic_read(&(bh
->b_count
)), le32_to_cpu(BHDR(bh
)->h_refcount
));
380 if (ext3_xattr_check_block(bh
)) {
381 ext3_error(inode
->i_sb
, __func__
,
382 "inode %lu: bad block "E3FSBLK
, inode
->i_ino
,
383 EXT3_I(inode
)->i_file_acl
);
387 ext3_xattr_cache_insert(bh
);
388 error
= ext3_xattr_list_entries(dentry
, BFIRST(bh
), buffer
, buffer_size
);
397 ext3_xattr_ibody_list(struct dentry
*dentry
, char *buffer
, size_t buffer_size
)
399 struct inode
*inode
= dentry
->d_inode
;
400 struct ext3_xattr_ibody_header
*header
;
401 struct ext3_inode
*raw_inode
;
402 struct ext3_iloc iloc
;
406 if (!ext3_test_inode_state(inode
, EXT3_STATE_XATTR
))
408 error
= ext3_get_inode_loc(inode
, &iloc
);
411 raw_inode
= ext3_raw_inode(&iloc
);
412 header
= IHDR(inode
, raw_inode
);
413 end
= (void *)raw_inode
+ EXT3_SB(inode
->i_sb
)->s_inode_size
;
414 error
= ext3_xattr_check_names(IFIRST(header
), end
);
417 error
= ext3_xattr_list_entries(dentry
, IFIRST(header
),
418 buffer
, buffer_size
);
428 * Copy a list of attribute names into the buffer
429 * provided, or compute the buffer size required.
430 * Buffer is NULL to compute the size of the buffer required.
432 * Returns a negative error number on failure, or the number of bytes
433 * used / required on success.
436 ext3_xattr_list(struct dentry
*dentry
, char *buffer
, size_t buffer_size
)
438 int i_error
, b_error
;
440 down_read(&EXT3_I(dentry
->d_inode
)->xattr_sem
);
441 i_error
= ext3_xattr_ibody_list(dentry
, buffer
, buffer_size
);
447 buffer_size
-= i_error
;
449 b_error
= ext3_xattr_block_list(dentry
, buffer
, buffer_size
);
453 up_read(&EXT3_I(dentry
->d_inode
)->xattr_sem
);
454 return i_error
+ b_error
;
458 * If the EXT3_FEATURE_COMPAT_EXT_ATTR feature of this file system is
461 static void ext3_xattr_update_super_block(handle_t
*handle
,
462 struct super_block
*sb
)
464 if (EXT3_HAS_COMPAT_FEATURE(sb
, EXT3_FEATURE_COMPAT_EXT_ATTR
))
467 if (ext3_journal_get_write_access(handle
, EXT3_SB(sb
)->s_sbh
) == 0) {
468 EXT3_SET_COMPAT_FEATURE(sb
, EXT3_FEATURE_COMPAT_EXT_ATTR
);
469 ext3_journal_dirty_metadata(handle
, EXT3_SB(sb
)->s_sbh
);
474 * Release the xattr block BH: If the reference count is > 1, decrement
475 * it; otherwise free the block.
478 ext3_xattr_release_block(handle_t
*handle
, struct inode
*inode
,
479 struct buffer_head
*bh
)
481 struct mb_cache_entry
*ce
= NULL
;
484 ce
= mb_cache_entry_get(ext3_xattr_cache
, bh
->b_bdev
, bh
->b_blocknr
);
485 error
= ext3_journal_get_write_access(handle
, bh
);
491 if (BHDR(bh
)->h_refcount
== cpu_to_le32(1)) {
492 ea_bdebug(bh
, "refcount now=0; freeing");
494 mb_cache_entry_free(ce
);
495 ext3_free_blocks(handle
, inode
, bh
->b_blocknr
, 1);
497 ext3_forget(handle
, 1, inode
, bh
, bh
->b_blocknr
);
499 le32_add_cpu(&BHDR(bh
)->h_refcount
, -1);
500 error
= ext3_journal_dirty_metadata(handle
, bh
);
503 dquot_free_block(inode
, 1);
504 ea_bdebug(bh
, "refcount now=%d; releasing",
505 le32_to_cpu(BHDR(bh
)->h_refcount
));
507 mb_cache_entry_release(ce
);
511 ext3_std_error(inode
->i_sb
, error
);
515 struct ext3_xattr_info
{
522 struct ext3_xattr_search
{
523 struct ext3_xattr_entry
*first
;
526 struct ext3_xattr_entry
*here
;
531 ext3_xattr_set_entry(struct ext3_xattr_info
*i
, struct ext3_xattr_search
*s
)
533 struct ext3_xattr_entry
*last
;
534 size_t free
, min_offs
= s
->end
- s
->base
, name_len
= strlen(i
->name
);
536 /* Compute min_offs and last. */
538 for (; !IS_LAST_ENTRY(last
); last
= EXT3_XATTR_NEXT(last
)) {
539 if (!last
->e_value_block
&& last
->e_value_size
) {
540 size_t offs
= le16_to_cpu(last
->e_value_offs
);
545 free
= min_offs
- ((void *)last
- s
->base
) - sizeof(__u32
);
547 if (!s
->here
->e_value_block
&& s
->here
->e_value_size
) {
548 size_t size
= le32_to_cpu(s
->here
->e_value_size
);
549 free
+= EXT3_XATTR_SIZE(size
);
551 free
+= EXT3_XATTR_LEN(name_len
);
554 if (free
< EXT3_XATTR_SIZE(i
->value_len
) ||
555 free
< EXT3_XATTR_LEN(name_len
) +
556 EXT3_XATTR_SIZE(i
->value_len
))
560 if (i
->value
&& s
->not_found
) {
561 /* Insert the new name. */
562 size_t size
= EXT3_XATTR_LEN(name_len
);
563 size_t rest
= (void *)last
- (void *)s
->here
+ sizeof(__u32
);
564 memmove((void *)s
->here
+ size
, s
->here
, rest
);
565 memset(s
->here
, 0, size
);
566 s
->here
->e_name_index
= i
->name_index
;
567 s
->here
->e_name_len
= name_len
;
568 memcpy(s
->here
->e_name
, i
->name
, name_len
);
570 if (!s
->here
->e_value_block
&& s
->here
->e_value_size
) {
571 void *first_val
= s
->base
+ min_offs
;
572 size_t offs
= le16_to_cpu(s
->here
->e_value_offs
);
573 void *val
= s
->base
+ offs
;
574 size_t size
= EXT3_XATTR_SIZE(
575 le32_to_cpu(s
->here
->e_value_size
));
577 if (i
->value
&& size
== EXT3_XATTR_SIZE(i
->value_len
)) {
578 /* The old and the new value have the same
579 size. Just replace. */
580 s
->here
->e_value_size
=
581 cpu_to_le32(i
->value_len
);
582 memset(val
+ size
- EXT3_XATTR_PAD
, 0,
583 EXT3_XATTR_PAD
); /* Clear pad bytes. */
584 memcpy(val
, i
->value
, i
->value_len
);
588 /* Remove the old value. */
589 memmove(first_val
+ size
, first_val
, val
- first_val
);
590 memset(first_val
, 0, size
);
591 s
->here
->e_value_size
= 0;
592 s
->here
->e_value_offs
= 0;
595 /* Adjust all value offsets. */
597 while (!IS_LAST_ENTRY(last
)) {
598 size_t o
= le16_to_cpu(last
->e_value_offs
);
599 if (!last
->e_value_block
&&
600 last
->e_value_size
&& o
< offs
)
602 cpu_to_le16(o
+ size
);
603 last
= EXT3_XATTR_NEXT(last
);
607 /* Remove the old name. */
608 size_t size
= EXT3_XATTR_LEN(name_len
);
609 last
= ENTRY((void *)last
- size
);
610 memmove(s
->here
, (void *)s
->here
+ size
,
611 (void *)last
- (void *)s
->here
+ sizeof(__u32
));
612 memset(last
, 0, size
);
617 /* Insert the new value. */
618 s
->here
->e_value_size
= cpu_to_le32(i
->value_len
);
620 size_t size
= EXT3_XATTR_SIZE(i
->value_len
);
621 void *val
= s
->base
+ min_offs
- size
;
622 s
->here
->e_value_offs
= cpu_to_le16(min_offs
- size
);
623 memset(val
+ size
- EXT3_XATTR_PAD
, 0,
624 EXT3_XATTR_PAD
); /* Clear the pad bytes. */
625 memcpy(val
, i
->value
, i
->value_len
);
631 struct ext3_xattr_block_find
{
632 struct ext3_xattr_search s
;
633 struct buffer_head
*bh
;
637 ext3_xattr_block_find(struct inode
*inode
, struct ext3_xattr_info
*i
,
638 struct ext3_xattr_block_find
*bs
)
640 struct super_block
*sb
= inode
->i_sb
;
643 ea_idebug(inode
, "name=%d.%s, value=%p, value_len=%ld",
644 i
->name_index
, i
->name
, i
->value
, (long)i
->value_len
);
646 if (EXT3_I(inode
)->i_file_acl
) {
647 /* The inode already has an extended attribute block. */
648 bs
->bh
= sb_bread(sb
, EXT3_I(inode
)->i_file_acl
);
652 ea_bdebug(bs
->bh
, "b_count=%d, refcount=%d",
653 atomic_read(&(bs
->bh
->b_count
)),
654 le32_to_cpu(BHDR(bs
->bh
)->h_refcount
));
655 if (ext3_xattr_check_block(bs
->bh
)) {
656 ext3_error(sb
, __func__
,
657 "inode %lu: bad block "E3FSBLK
, inode
->i_ino
,
658 EXT3_I(inode
)->i_file_acl
);
662 /* Find the named attribute. */
663 bs
->s
.base
= BHDR(bs
->bh
);
664 bs
->s
.first
= BFIRST(bs
->bh
);
665 bs
->s
.end
= bs
->bh
->b_data
+ bs
->bh
->b_size
;
666 bs
->s
.here
= bs
->s
.first
;
667 error
= ext3_xattr_find_entry(&bs
->s
.here
, i
->name_index
,
668 i
->name
, bs
->bh
->b_size
, 1);
669 if (error
&& error
!= -ENODATA
)
671 bs
->s
.not_found
= error
;
680 ext3_xattr_block_set(handle_t
*handle
, struct inode
*inode
,
681 struct ext3_xattr_info
*i
,
682 struct ext3_xattr_block_find
*bs
)
684 struct super_block
*sb
= inode
->i_sb
;
685 struct buffer_head
*new_bh
= NULL
;
686 struct ext3_xattr_search
*s
= &bs
->s
;
687 struct mb_cache_entry
*ce
= NULL
;
690 #define header(x) ((struct ext3_xattr_header *)(x))
692 if (i
->value
&& i
->value_len
> sb
->s_blocksize
)
695 ce
= mb_cache_entry_get(ext3_xattr_cache
, bs
->bh
->b_bdev
,
697 error
= ext3_journal_get_write_access(handle
, bs
->bh
);
702 if (header(s
->base
)->h_refcount
== cpu_to_le32(1)) {
704 mb_cache_entry_free(ce
);
707 ea_bdebug(bs
->bh
, "modifying in-place");
708 error
= ext3_xattr_set_entry(i
, s
);
710 if (!IS_LAST_ENTRY(s
->first
))
711 ext3_xattr_rehash(header(s
->base
),
713 ext3_xattr_cache_insert(bs
->bh
);
715 unlock_buffer(bs
->bh
);
719 error
= ext3_journal_dirty_metadata(handle
,
725 int offset
= (char *)s
->here
- bs
->bh
->b_data
;
727 unlock_buffer(bs
->bh
);
728 journal_release_buffer(handle
, bs
->bh
);
731 mb_cache_entry_release(ce
);
734 ea_bdebug(bs
->bh
, "cloning");
735 s
->base
= kmalloc(bs
->bh
->b_size
, GFP_NOFS
);
739 memcpy(s
->base
, BHDR(bs
->bh
), bs
->bh
->b_size
);
740 s
->first
= ENTRY(header(s
->base
)+1);
741 header(s
->base
)->h_refcount
= cpu_to_le32(1);
742 s
->here
= ENTRY(s
->base
+ offset
);
743 s
->end
= s
->base
+ bs
->bh
->b_size
;
746 /* Allocate a buffer where we construct the new block. */
747 s
->base
= kzalloc(sb
->s_blocksize
, GFP_NOFS
);
748 /* assert(header == s->base) */
752 header(s
->base
)->h_magic
= cpu_to_le32(EXT3_XATTR_MAGIC
);
753 header(s
->base
)->h_blocks
= cpu_to_le32(1);
754 header(s
->base
)->h_refcount
= cpu_to_le32(1);
755 s
->first
= ENTRY(header(s
->base
)+1);
756 s
->here
= ENTRY(header(s
->base
)+1);
757 s
->end
= s
->base
+ sb
->s_blocksize
;
760 error
= ext3_xattr_set_entry(i
, s
);
765 if (!IS_LAST_ENTRY(s
->first
))
766 ext3_xattr_rehash(header(s
->base
), s
->here
);
769 if (!IS_LAST_ENTRY(s
->first
)) {
770 new_bh
= ext3_xattr_cache_find(inode
, header(s
->base
), &ce
);
772 /* We found an identical block in the cache. */
773 if (new_bh
== bs
->bh
)
774 ea_bdebug(new_bh
, "keeping");
776 /* The old block is released after updating
778 error
= dquot_alloc_block(inode
, 1);
781 error
= ext3_journal_get_write_access(handle
,
786 le32_add_cpu(&BHDR(new_bh
)->h_refcount
, 1);
787 ea_bdebug(new_bh
, "reusing; refcount now=%d",
788 le32_to_cpu(BHDR(new_bh
)->h_refcount
));
789 unlock_buffer(new_bh
);
790 error
= ext3_journal_dirty_metadata(handle
,
795 mb_cache_entry_release(ce
);
797 } else if (bs
->bh
&& s
->base
== bs
->bh
->b_data
) {
798 /* We were modifying this block in-place. */
799 ea_bdebug(bs
->bh
, "keeping this block");
803 /* We need to allocate a new block */
804 ext3_fsblk_t goal
= ext3_group_first_block_no(sb
,
805 EXT3_I(inode
)->i_block_group
);
809 * Protect us agaist concurrent allocations to the
810 * same inode from ext3_..._writepage(). Reservation
811 * code does not expect racing allocations.
813 mutex_lock(&EXT3_I(inode
)->truncate_mutex
);
814 block
= ext3_new_block(handle
, inode
, goal
, &error
);
815 mutex_unlock(&EXT3_I(inode
)->truncate_mutex
);
818 ea_idebug(inode
, "creating block %d", block
);
820 new_bh
= sb_getblk(sb
, block
);
823 ext3_free_blocks(handle
, inode
, block
, 1);
828 error
= ext3_journal_get_create_access(handle
, new_bh
);
830 unlock_buffer(new_bh
);
833 memcpy(new_bh
->b_data
, s
->base
, new_bh
->b_size
);
834 set_buffer_uptodate(new_bh
);
835 unlock_buffer(new_bh
);
836 ext3_xattr_cache_insert(new_bh
);
837 error
= ext3_journal_dirty_metadata(handle
, new_bh
);
843 /* Update the inode. */
844 EXT3_I(inode
)->i_file_acl
= new_bh
? new_bh
->b_blocknr
: 0;
846 /* Drop the previous xattr block. */
847 if (bs
->bh
&& bs
->bh
!= new_bh
)
848 ext3_xattr_release_block(handle
, inode
, bs
->bh
);
853 mb_cache_entry_release(ce
);
855 if (!(bs
->bh
&& s
->base
== bs
->bh
->b_data
))
861 dquot_free_block(inode
, 1);
865 ext3_error(inode
->i_sb
, __func__
,
866 "inode %lu: bad block "E3FSBLK
, inode
->i_ino
,
867 EXT3_I(inode
)->i_file_acl
);
873 struct ext3_xattr_ibody_find
{
874 struct ext3_xattr_search s
;
875 struct ext3_iloc iloc
;
879 ext3_xattr_ibody_find(struct inode
*inode
, struct ext3_xattr_info
*i
,
880 struct ext3_xattr_ibody_find
*is
)
882 struct ext3_xattr_ibody_header
*header
;
883 struct ext3_inode
*raw_inode
;
886 if (EXT3_I(inode
)->i_extra_isize
== 0)
888 raw_inode
= ext3_raw_inode(&is
->iloc
);
889 header
= IHDR(inode
, raw_inode
);
890 is
->s
.base
= is
->s
.first
= IFIRST(header
);
891 is
->s
.here
= is
->s
.first
;
892 is
->s
.end
= (void *)raw_inode
+ EXT3_SB(inode
->i_sb
)->s_inode_size
;
893 if (ext3_test_inode_state(inode
, EXT3_STATE_XATTR
)) {
894 error
= ext3_xattr_check_names(IFIRST(header
), is
->s
.end
);
897 /* Find the named attribute. */
898 error
= ext3_xattr_find_entry(&is
->s
.here
, i
->name_index
,
900 (void *)is
->s
.base
, 0);
901 if (error
&& error
!= -ENODATA
)
903 is
->s
.not_found
= error
;
909 ext3_xattr_ibody_set(handle_t
*handle
, struct inode
*inode
,
910 struct ext3_xattr_info
*i
,
911 struct ext3_xattr_ibody_find
*is
)
913 struct ext3_xattr_ibody_header
*header
;
914 struct ext3_xattr_search
*s
= &is
->s
;
917 if (EXT3_I(inode
)->i_extra_isize
== 0)
919 error
= ext3_xattr_set_entry(i
, s
);
922 header
= IHDR(inode
, ext3_raw_inode(&is
->iloc
));
923 if (!IS_LAST_ENTRY(s
->first
)) {
924 header
->h_magic
= cpu_to_le32(EXT3_XATTR_MAGIC
);
925 ext3_set_inode_state(inode
, EXT3_STATE_XATTR
);
927 header
->h_magic
= cpu_to_le32(0);
928 ext3_clear_inode_state(inode
, EXT3_STATE_XATTR
);
934 * ext3_xattr_set_handle()
936 * Create, replace or remove an extended attribute for this inode. Value
937 * is NULL to remove an existing extended attribute, and non-NULL to
938 * either replace an existing extended attribute, or create a new extended
939 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
940 * specify that an extended attribute must exist and must not exist
941 * previous to the call, respectively.
943 * Returns 0, or a negative error number on failure.
946 ext3_xattr_set_handle(handle_t
*handle
, struct inode
*inode
, int name_index
,
947 const char *name
, const void *value
, size_t value_len
,
950 struct ext3_xattr_info i
= {
951 .name_index
= name_index
,
954 .value_len
= value_len
,
957 struct ext3_xattr_ibody_find is
= {
958 .s
= { .not_found
= -ENODATA
, },
960 struct ext3_xattr_block_find bs
= {
961 .s
= { .not_found
= -ENODATA
, },
967 if (strlen(name
) > 255)
969 down_write(&EXT3_I(inode
)->xattr_sem
);
970 error
= ext3_get_inode_loc(inode
, &is
.iloc
);
974 error
= ext3_journal_get_write_access(handle
, is
.iloc
.bh
);
978 if (ext3_test_inode_state(inode
, EXT3_STATE_NEW
)) {
979 struct ext3_inode
*raw_inode
= ext3_raw_inode(&is
.iloc
);
980 memset(raw_inode
, 0, EXT3_SB(inode
->i_sb
)->s_inode_size
);
981 ext3_clear_inode_state(inode
, EXT3_STATE_NEW
);
984 error
= ext3_xattr_ibody_find(inode
, &i
, &is
);
988 error
= ext3_xattr_block_find(inode
, &i
, &bs
);
991 if (is
.s
.not_found
&& bs
.s
.not_found
) {
993 if (flags
& XATTR_REPLACE
)
1000 if (flags
& XATTR_CREATE
)
1004 if (!is
.s
.not_found
)
1005 error
= ext3_xattr_ibody_set(handle
, inode
, &i
, &is
);
1006 else if (!bs
.s
.not_found
)
1007 error
= ext3_xattr_block_set(handle
, inode
, &i
, &bs
);
1009 error
= ext3_xattr_ibody_set(handle
, inode
, &i
, &is
);
1010 if (!error
&& !bs
.s
.not_found
) {
1012 error
= ext3_xattr_block_set(handle
, inode
, &i
, &bs
);
1013 } else if (error
== -ENOSPC
) {
1014 if (EXT3_I(inode
)->i_file_acl
&& !bs
.s
.base
) {
1015 error
= ext3_xattr_block_find(inode
, &i
, &bs
);
1019 error
= ext3_xattr_block_set(handle
, inode
, &i
, &bs
);
1022 if (!is
.s
.not_found
) {
1024 error
= ext3_xattr_ibody_set(handle
, inode
, &i
,
1030 ext3_xattr_update_super_block(handle
, inode
->i_sb
);
1031 inode
->i_ctime
= CURRENT_TIME_SEC
;
1032 error
= ext3_mark_iloc_dirty(handle
, inode
, &is
.iloc
);
1034 * The bh is consumed by ext3_mark_iloc_dirty, even with
1045 up_write(&EXT3_I(inode
)->xattr_sem
);
1052 * Like ext3_xattr_set_handle, but start from an inode. This extended
1053 * attribute modification is a filesystem transaction by itself.
1055 * Returns 0, or a negative error number on failure.
1058 ext3_xattr_set(struct inode
*inode
, int name_index
, const char *name
,
1059 const void *value
, size_t value_len
, int flags
)
1062 int error
, retries
= 0;
1065 handle
= ext3_journal_start(inode
, EXT3_DATA_TRANS_BLOCKS(inode
->i_sb
));
1066 if (IS_ERR(handle
)) {
1067 error
= PTR_ERR(handle
);
1071 error
= ext3_xattr_set_handle(handle
, inode
, name_index
, name
,
1072 value
, value_len
, flags
);
1073 error2
= ext3_journal_stop(handle
);
1074 if (error
== -ENOSPC
&&
1075 ext3_should_retry_alloc(inode
->i_sb
, &retries
))
1085 * ext3_xattr_delete_inode()
1087 * Free extended attribute resources associated with this inode. This
1088 * is called immediately before an inode is freed. We have exclusive
1089 * access to the inode.
1092 ext3_xattr_delete_inode(handle_t
*handle
, struct inode
*inode
)
1094 struct buffer_head
*bh
= NULL
;
1096 if (!EXT3_I(inode
)->i_file_acl
)
1098 bh
= sb_bread(inode
->i_sb
, EXT3_I(inode
)->i_file_acl
);
1100 ext3_error(inode
->i_sb
, __func__
,
1101 "inode %lu: block "E3FSBLK
" read error", inode
->i_ino
,
1102 EXT3_I(inode
)->i_file_acl
);
1105 if (BHDR(bh
)->h_magic
!= cpu_to_le32(EXT3_XATTR_MAGIC
) ||
1106 BHDR(bh
)->h_blocks
!= cpu_to_le32(1)) {
1107 ext3_error(inode
->i_sb
, __func__
,
1108 "inode %lu: bad block "E3FSBLK
, inode
->i_ino
,
1109 EXT3_I(inode
)->i_file_acl
);
1112 ext3_xattr_release_block(handle
, inode
, bh
);
1113 EXT3_I(inode
)->i_file_acl
= 0;
1120 * ext3_xattr_put_super()
1122 * This is called when a file system is unmounted.
1125 ext3_xattr_put_super(struct super_block
*sb
)
1127 mb_cache_shrink(sb
->s_bdev
);
1131 * ext3_xattr_cache_insert()
1133 * Create a new entry in the extended attribute cache, and insert
1134 * it unless such an entry is already in the cache.
1136 * Returns 0, or a negative error number on failure.
1139 ext3_xattr_cache_insert(struct buffer_head
*bh
)
1141 __u32 hash
= le32_to_cpu(BHDR(bh
)->h_hash
);
1142 struct mb_cache_entry
*ce
;
1145 ce
= mb_cache_entry_alloc(ext3_xattr_cache
, GFP_NOFS
);
1147 ea_bdebug(bh
, "out of memory");
1150 error
= mb_cache_entry_insert(ce
, bh
->b_bdev
, bh
->b_blocknr
, hash
);
1152 mb_cache_entry_free(ce
);
1153 if (error
== -EBUSY
) {
1154 ea_bdebug(bh
, "already in cache");
1158 ea_bdebug(bh
, "inserting [%x]", (int)hash
);
1159 mb_cache_entry_release(ce
);
1166 * Compare two extended attribute blocks for equality.
1168 * Returns 0 if the blocks are equal, 1 if they differ, and
1169 * a negative error number on errors.
1172 ext3_xattr_cmp(struct ext3_xattr_header
*header1
,
1173 struct ext3_xattr_header
*header2
)
1175 struct ext3_xattr_entry
*entry1
, *entry2
;
1177 entry1
= ENTRY(header1
+1);
1178 entry2
= ENTRY(header2
+1);
1179 while (!IS_LAST_ENTRY(entry1
)) {
1180 if (IS_LAST_ENTRY(entry2
))
1182 if (entry1
->e_hash
!= entry2
->e_hash
||
1183 entry1
->e_name_index
!= entry2
->e_name_index
||
1184 entry1
->e_name_len
!= entry2
->e_name_len
||
1185 entry1
->e_value_size
!= entry2
->e_value_size
||
1186 memcmp(entry1
->e_name
, entry2
->e_name
, entry1
->e_name_len
))
1188 if (entry1
->e_value_block
!= 0 || entry2
->e_value_block
!= 0)
1190 if (memcmp((char *)header1
+ le16_to_cpu(entry1
->e_value_offs
),
1191 (char *)header2
+ le16_to_cpu(entry2
->e_value_offs
),
1192 le32_to_cpu(entry1
->e_value_size
)))
1195 entry1
= EXT3_XATTR_NEXT(entry1
);
1196 entry2
= EXT3_XATTR_NEXT(entry2
);
1198 if (!IS_LAST_ENTRY(entry2
))
1204 * ext3_xattr_cache_find()
1206 * Find an identical extended attribute block.
1208 * Returns a pointer to the block found, or NULL if such a block was
1209 * not found or an error occurred.
1211 static struct buffer_head
*
1212 ext3_xattr_cache_find(struct inode
*inode
, struct ext3_xattr_header
*header
,
1213 struct mb_cache_entry
**pce
)
1215 __u32 hash
= le32_to_cpu(header
->h_hash
);
1216 struct mb_cache_entry
*ce
;
1218 if (!header
->h_hash
)
1219 return NULL
; /* never share */
1220 ea_idebug(inode
, "looking for cached blocks [%x]", (int)hash
);
1222 ce
= mb_cache_entry_find_first(ext3_xattr_cache
, inode
->i_sb
->s_bdev
,
1225 struct buffer_head
*bh
;
1228 if (PTR_ERR(ce
) == -EAGAIN
)
1232 bh
= sb_bread(inode
->i_sb
, ce
->e_block
);
1234 ext3_error(inode
->i_sb
, __func__
,
1235 "inode %lu: block %lu read error",
1236 inode
->i_ino
, (unsigned long) ce
->e_block
);
1237 } else if (le32_to_cpu(BHDR(bh
)->h_refcount
) >=
1238 EXT3_XATTR_REFCOUNT_MAX
) {
1239 ea_idebug(inode
, "block %lu refcount %d>=%d",
1240 (unsigned long) ce
->e_block
,
1241 le32_to_cpu(BHDR(bh
)->h_refcount
),
1242 EXT3_XATTR_REFCOUNT_MAX
);
1243 } else if (ext3_xattr_cmp(header
, BHDR(bh
)) == 0) {
1248 ce
= mb_cache_entry_find_next(ce
, inode
->i_sb
->s_bdev
, hash
);
1253 #define NAME_HASH_SHIFT 5
1254 #define VALUE_HASH_SHIFT 16
1257 * ext3_xattr_hash_entry()
1259 * Compute the hash of an extended attribute.
1261 static inline void ext3_xattr_hash_entry(struct ext3_xattr_header
*header
,
1262 struct ext3_xattr_entry
*entry
)
1265 char *name
= entry
->e_name
;
1268 for (n
=0; n
< entry
->e_name_len
; n
++) {
1269 hash
= (hash
<< NAME_HASH_SHIFT
) ^
1270 (hash
>> (8*sizeof(hash
) - NAME_HASH_SHIFT
)) ^
1274 if (entry
->e_value_block
== 0 && entry
->e_value_size
!= 0) {
1275 __le32
*value
= (__le32
*)((char *)header
+
1276 le16_to_cpu(entry
->e_value_offs
));
1277 for (n
= (le32_to_cpu(entry
->e_value_size
) +
1278 EXT3_XATTR_ROUND
) >> EXT3_XATTR_PAD_BITS
; n
; n
--) {
1279 hash
= (hash
<< VALUE_HASH_SHIFT
) ^
1280 (hash
>> (8*sizeof(hash
) - VALUE_HASH_SHIFT
)) ^
1281 le32_to_cpu(*value
++);
1284 entry
->e_hash
= cpu_to_le32(hash
);
1287 #undef NAME_HASH_SHIFT
1288 #undef VALUE_HASH_SHIFT
1290 #define BLOCK_HASH_SHIFT 16
1293 * ext3_xattr_rehash()
1295 * Re-compute the extended attribute hash value after an entry has changed.
1297 static void ext3_xattr_rehash(struct ext3_xattr_header
*header
,
1298 struct ext3_xattr_entry
*entry
)
1300 struct ext3_xattr_entry
*here
;
1303 ext3_xattr_hash_entry(header
, entry
);
1304 here
= ENTRY(header
+1);
1305 while (!IS_LAST_ENTRY(here
)) {
1306 if (!here
->e_hash
) {
1307 /* Block is not shared if an entry's hash value == 0 */
1311 hash
= (hash
<< BLOCK_HASH_SHIFT
) ^
1312 (hash
>> (8*sizeof(hash
) - BLOCK_HASH_SHIFT
)) ^
1313 le32_to_cpu(here
->e_hash
);
1314 here
= EXT3_XATTR_NEXT(here
);
1316 header
->h_hash
= cpu_to_le32(hash
);
1319 #undef BLOCK_HASH_SHIFT
1322 init_ext3_xattr(void)
1324 ext3_xattr_cache
= mb_cache_create("ext3_xattr", 6);
1325 if (!ext3_xattr_cache
)
1331 exit_ext3_xattr(void)
1333 if (ext3_xattr_cache
)
1334 mb_cache_destroy(ext3_xattr_cache
);
1335 ext3_xattr_cache
= NULL
;