2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/bio.h>
20 #include <linux/slab.h>
21 #include <linux/pagemap.h>
22 #include <linux/highmem.h>
25 #include "transaction.h"
27 #include "print-tree.h"
29 #define __MAX_CSUM_ITEMS(r, size) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \
30 sizeof(struct btrfs_item) * 2) / \
33 #define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \
36 #define MAX_ORDERED_SUM_BYTES(r) ((PAGE_SIZE - \
37 sizeof(struct btrfs_ordered_sum)) / \
38 sizeof(u32) * (r)->sectorsize)
40 int btrfs_insert_file_extent(struct btrfs_trans_handle
*trans
,
41 struct btrfs_root
*root
,
42 u64 objectid
, u64 pos
,
43 u64 disk_offset
, u64 disk_num_bytes
,
44 u64 num_bytes
, u64 offset
, u64 ram_bytes
,
45 u8 compression
, u8 encryption
, u16 other_encoding
)
48 struct btrfs_file_extent_item
*item
;
49 struct btrfs_key file_key
;
50 struct btrfs_path
*path
;
51 struct extent_buffer
*leaf
;
53 path
= btrfs_alloc_path();
56 file_key
.objectid
= objectid
;
57 file_key
.offset
= pos
;
58 btrfs_set_key_type(&file_key
, BTRFS_EXTENT_DATA_KEY
);
60 path
->leave_spinning
= 1;
61 ret
= btrfs_insert_empty_item(trans
, root
, path
, &file_key
,
65 BUG_ON(ret
); /* Can't happen */
66 leaf
= path
->nodes
[0];
67 item
= btrfs_item_ptr(leaf
, path
->slots
[0],
68 struct btrfs_file_extent_item
);
69 btrfs_set_file_extent_disk_bytenr(leaf
, item
, disk_offset
);
70 btrfs_set_file_extent_disk_num_bytes(leaf
, item
, disk_num_bytes
);
71 btrfs_set_file_extent_offset(leaf
, item
, offset
);
72 btrfs_set_file_extent_num_bytes(leaf
, item
, num_bytes
);
73 btrfs_set_file_extent_ram_bytes(leaf
, item
, ram_bytes
);
74 btrfs_set_file_extent_generation(leaf
, item
, trans
->transid
);
75 btrfs_set_file_extent_type(leaf
, item
, BTRFS_FILE_EXTENT_REG
);
76 btrfs_set_file_extent_compression(leaf
, item
, compression
);
77 btrfs_set_file_extent_encryption(leaf
, item
, encryption
);
78 btrfs_set_file_extent_other_encoding(leaf
, item
, other_encoding
);
80 btrfs_mark_buffer_dirty(leaf
);
82 btrfs_free_path(path
);
86 static struct btrfs_csum_item
*
87 btrfs_lookup_csum(struct btrfs_trans_handle
*trans
,
88 struct btrfs_root
*root
,
89 struct btrfs_path
*path
,
93 struct btrfs_key file_key
;
94 struct btrfs_key found_key
;
95 struct btrfs_csum_item
*item
;
96 struct extent_buffer
*leaf
;
98 u16 csum_size
= btrfs_super_csum_size(root
->fs_info
->super_copy
);
101 file_key
.objectid
= BTRFS_EXTENT_CSUM_OBJECTID
;
102 file_key
.offset
= bytenr
;
103 btrfs_set_key_type(&file_key
, BTRFS_EXTENT_CSUM_KEY
);
104 ret
= btrfs_search_slot(trans
, root
, &file_key
, path
, 0, cow
);
107 leaf
= path
->nodes
[0];
110 if (path
->slots
[0] == 0)
113 btrfs_item_key_to_cpu(leaf
, &found_key
, path
->slots
[0]);
114 if (btrfs_key_type(&found_key
) != BTRFS_EXTENT_CSUM_KEY
)
117 csum_offset
= (bytenr
- found_key
.offset
) >>
118 root
->fs_info
->sb
->s_blocksize_bits
;
119 csums_in_item
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
120 csums_in_item
/= csum_size
;
122 if (csum_offset
== csums_in_item
) {
125 } else if (csum_offset
> csums_in_item
) {
129 item
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_csum_item
);
130 item
= (struct btrfs_csum_item
*)((unsigned char *)item
+
131 csum_offset
* csum_size
);
139 int btrfs_lookup_file_extent(struct btrfs_trans_handle
*trans
,
140 struct btrfs_root
*root
,
141 struct btrfs_path
*path
, u64 objectid
,
145 struct btrfs_key file_key
;
146 int ins_len
= mod
< 0 ? -1 : 0;
149 file_key
.objectid
= objectid
;
150 file_key
.offset
= offset
;
151 btrfs_set_key_type(&file_key
, BTRFS_EXTENT_DATA_KEY
);
152 ret
= btrfs_search_slot(trans
, root
, &file_key
, path
, ins_len
, cow
);
156 static void btrfs_io_bio_endio_readpage(struct btrfs_io_bio
*bio
, int err
)
158 kfree(bio
->csum_allocated
);
161 static int __btrfs_lookup_bio_sums(struct btrfs_root
*root
,
162 struct inode
*inode
, struct bio
*bio
,
163 u64 logical_offset
, u32
*dst
, int dio
)
165 struct bio_vec
*bvec
= bio
->bi_io_vec
;
166 struct btrfs_io_bio
*btrfs_bio
= btrfs_io_bio(bio
);
167 struct btrfs_csum_item
*item
= NULL
;
168 struct extent_io_tree
*io_tree
= &BTRFS_I(inode
)->io_tree
;
169 struct btrfs_path
*path
;
172 u64 item_start_offset
= 0;
173 u64 item_last_offset
= 0;
179 u16 csum_size
= btrfs_super_csum_size(root
->fs_info
->super_copy
);
181 path
= btrfs_alloc_path();
185 nblocks
= bio
->bi_size
>> inode
->i_sb
->s_blocksize_bits
;
187 if (nblocks
* csum_size
> BTRFS_BIO_INLINE_CSUM_SIZE
) {
188 btrfs_bio
->csum_allocated
= kmalloc(nblocks
* csum_size
,
190 if (!btrfs_bio
->csum_allocated
) {
191 btrfs_free_path(path
);
194 btrfs_bio
->csum
= btrfs_bio
->csum_allocated
;
195 btrfs_bio
->end_io
= btrfs_io_bio_endio_readpage
;
197 btrfs_bio
->csum
= btrfs_bio
->csum_inline
;
199 csum
= btrfs_bio
->csum
;
204 if (bio
->bi_size
> PAGE_CACHE_SIZE
* 8)
207 WARN_ON(bio
->bi_vcnt
<= 0);
210 * the free space stuff is only read when it hasn't been
211 * updated in the current transaction. So, we can safely
212 * read from the commit root and sidestep a nasty deadlock
213 * between reading the free space cache and updating the csum tree.
215 if (btrfs_is_free_space_inode(inode
)) {
216 path
->search_commit_root
= 1;
217 path
->skip_locking
= 1;
220 disk_bytenr
= (u64
)bio
->bi_sector
<< 9;
222 offset
= logical_offset
;
223 while (bio_index
< bio
->bi_vcnt
) {
225 offset
= page_offset(bvec
->bv_page
) + bvec
->bv_offset
;
226 count
= btrfs_find_ordered_sum(inode
, offset
, disk_bytenr
,
227 (u32
*)csum
, nblocks
);
231 if (!item
|| disk_bytenr
< item_start_offset
||
232 disk_bytenr
>= item_last_offset
) {
233 struct btrfs_key found_key
;
237 btrfs_release_path(path
);
238 item
= btrfs_lookup_csum(NULL
, root
->fs_info
->csum_root
,
239 path
, disk_bytenr
, 0);
242 memset(csum
, 0, csum_size
);
243 if (BTRFS_I(inode
)->root
->root_key
.objectid
==
244 BTRFS_DATA_RELOC_TREE_OBJECTID
) {
245 set_extent_bits(io_tree
, offset
,
246 offset
+ bvec
->bv_len
- 1,
247 EXTENT_NODATASUM
, GFP_NOFS
);
249 btrfs_info(BTRFS_I(inode
)->root
->fs_info
,
250 "no csum found for inode %llu start %llu",
251 btrfs_ino(inode
), offset
);
254 btrfs_release_path(path
);
257 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
,
260 item_start_offset
= found_key
.offset
;
261 item_size
= btrfs_item_size_nr(path
->nodes
[0],
263 item_last_offset
= item_start_offset
+
264 (item_size
/ csum_size
) *
266 item
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
267 struct btrfs_csum_item
);
270 * this byte range must be able to fit inside
271 * a single leaf so it will also fit inside a u32
273 diff
= disk_bytenr
- item_start_offset
;
274 diff
= diff
/ root
->sectorsize
;
275 diff
= diff
* csum_size
;
276 count
= min_t(int, nblocks
, (item_last_offset
- disk_bytenr
) >>
277 inode
->i_sb
->s_blocksize_bits
);
278 read_extent_buffer(path
->nodes
[0], csum
,
279 ((unsigned long)item
) + diff
,
282 csum
+= count
* csum_size
;
285 disk_bytenr
+= bvec
->bv_len
;
286 offset
+= bvec
->bv_len
;
291 btrfs_free_path(path
);
295 int btrfs_lookup_bio_sums(struct btrfs_root
*root
, struct inode
*inode
,
296 struct bio
*bio
, u32
*dst
)
298 return __btrfs_lookup_bio_sums(root
, inode
, bio
, 0, dst
, 0);
301 int btrfs_lookup_bio_sums_dio(struct btrfs_root
*root
, struct inode
*inode
,
302 struct btrfs_dio_private
*dip
, struct bio
*bio
,
305 int len
= (bio
->bi_sector
<< 9) - dip
->disk_bytenr
;
306 u16 csum_size
= btrfs_super_csum_size(root
->fs_info
->super_copy
);
309 len
>>= inode
->i_sb
->s_blocksize_bits
;
312 ret
= __btrfs_lookup_bio_sums(root
, inode
, bio
, offset
,
313 (u32
*)(dip
->csum
+ len
), 1);
317 int btrfs_lookup_csums_range(struct btrfs_root
*root
, u64 start
, u64 end
,
318 struct list_head
*list
, int search_commit
)
320 struct btrfs_key key
;
321 struct btrfs_path
*path
;
322 struct extent_buffer
*leaf
;
323 struct btrfs_ordered_sum
*sums
;
324 struct btrfs_csum_item
*item
;
326 unsigned long offset
;
330 u16 csum_size
= btrfs_super_csum_size(root
->fs_info
->super_copy
);
332 ASSERT(start
== ALIGN(start
, root
->sectorsize
) &&
333 (end
+ 1) == ALIGN(end
+ 1, root
->sectorsize
));
335 path
= btrfs_alloc_path();
340 path
->skip_locking
= 1;
342 path
->search_commit_root
= 1;
345 key
.objectid
= BTRFS_EXTENT_CSUM_OBJECTID
;
347 key
.type
= BTRFS_EXTENT_CSUM_KEY
;
349 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
352 if (ret
> 0 && path
->slots
[0] > 0) {
353 leaf
= path
->nodes
[0];
354 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0] - 1);
355 if (key
.objectid
== BTRFS_EXTENT_CSUM_OBJECTID
&&
356 key
.type
== BTRFS_EXTENT_CSUM_KEY
) {
357 offset
= (start
- key
.offset
) >>
358 root
->fs_info
->sb
->s_blocksize_bits
;
359 if (offset
* csum_size
<
360 btrfs_item_size_nr(leaf
, path
->slots
[0] - 1))
365 while (start
<= end
) {
366 leaf
= path
->nodes
[0];
367 if (path
->slots
[0] >= btrfs_header_nritems(leaf
)) {
368 ret
= btrfs_next_leaf(root
, path
);
373 leaf
= path
->nodes
[0];
376 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
377 if (key
.objectid
!= BTRFS_EXTENT_CSUM_OBJECTID
||
378 key
.type
!= BTRFS_EXTENT_CSUM_KEY
||
382 if (key
.offset
> start
)
385 size
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
386 csum_end
= key
.offset
+ (size
/ csum_size
) * root
->sectorsize
;
387 if (csum_end
<= start
) {
392 csum_end
= min(csum_end
, end
+ 1);
393 item
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
394 struct btrfs_csum_item
);
395 while (start
< csum_end
) {
396 size
= min_t(size_t, csum_end
- start
,
397 MAX_ORDERED_SUM_BYTES(root
));
398 sums
= kzalloc(btrfs_ordered_sum_size(root
, size
),
405 sums
->bytenr
= start
;
406 sums
->len
= (int)size
;
408 offset
= (start
- key
.offset
) >>
409 root
->fs_info
->sb
->s_blocksize_bits
;
411 size
>>= root
->fs_info
->sb
->s_blocksize_bits
;
413 read_extent_buffer(path
->nodes
[0],
415 ((unsigned long)item
) + offset
,
418 start
+= root
->sectorsize
* size
;
419 list_add_tail(&sums
->list
, &tmplist
);
425 while (ret
< 0 && !list_empty(&tmplist
)) {
426 sums
= list_entry(&tmplist
, struct btrfs_ordered_sum
, list
);
427 list_del(&sums
->list
);
430 list_splice_tail(&tmplist
, list
);
432 btrfs_free_path(path
);
436 int btrfs_csum_one_bio(struct btrfs_root
*root
, struct inode
*inode
,
437 struct bio
*bio
, u64 file_start
, int contig
)
439 struct btrfs_ordered_sum
*sums
;
440 struct btrfs_ordered_extent
*ordered
;
442 struct bio_vec
*bvec
= bio
->bi_io_vec
;
445 unsigned long total_bytes
= 0;
446 unsigned long this_sum_bytes
= 0;
449 WARN_ON(bio
->bi_vcnt
<= 0);
450 sums
= kzalloc(btrfs_ordered_sum_size(root
, bio
->bi_size
), GFP_NOFS
);
454 sums
->len
= bio
->bi_size
;
455 INIT_LIST_HEAD(&sums
->list
);
460 offset
= page_offset(bvec
->bv_page
) + bvec
->bv_offset
;
462 ordered
= btrfs_lookup_ordered_extent(inode
, offset
);
463 BUG_ON(!ordered
); /* Logic error */
464 sums
->bytenr
= (u64
)bio
->bi_sector
<< 9;
467 while (bio_index
< bio
->bi_vcnt
) {
469 offset
= page_offset(bvec
->bv_page
) + bvec
->bv_offset
;
471 if (offset
>= ordered
->file_offset
+ ordered
->len
||
472 offset
< ordered
->file_offset
) {
473 unsigned long bytes_left
;
474 sums
->len
= this_sum_bytes
;
476 btrfs_add_ordered_sum(inode
, ordered
, sums
);
477 btrfs_put_ordered_extent(ordered
);
479 bytes_left
= bio
->bi_size
- total_bytes
;
481 sums
= kzalloc(btrfs_ordered_sum_size(root
, bytes_left
),
483 BUG_ON(!sums
); /* -ENOMEM */
484 sums
->len
= bytes_left
;
485 ordered
= btrfs_lookup_ordered_extent(inode
, offset
);
486 BUG_ON(!ordered
); /* Logic error */
487 sums
->bytenr
= ((u64
)bio
->bi_sector
<< 9) +
492 data
= kmap_atomic(bvec
->bv_page
);
493 sums
->sums
[index
] = ~(u32
)0;
494 sums
->sums
[index
] = btrfs_csum_data(data
+ bvec
->bv_offset
,
498 btrfs_csum_final(sums
->sums
[index
],
499 (char *)(sums
->sums
+ index
));
503 total_bytes
+= bvec
->bv_len
;
504 this_sum_bytes
+= bvec
->bv_len
;
505 offset
+= bvec
->bv_len
;
509 btrfs_add_ordered_sum(inode
, ordered
, sums
);
510 btrfs_put_ordered_extent(ordered
);
515 * helper function for csum removal, this expects the
516 * key to describe the csum pointed to by the path, and it expects
517 * the csum to overlap the range [bytenr, len]
519 * The csum should not be entirely contained in the range and the
520 * range should not be entirely contained in the csum.
522 * This calls btrfs_truncate_item with the correct args based on the
523 * overlap, and fixes up the key as required.
525 static noinline
void truncate_one_csum(struct btrfs_root
*root
,
526 struct btrfs_path
*path
,
527 struct btrfs_key
*key
,
530 struct extent_buffer
*leaf
;
531 u16 csum_size
= btrfs_super_csum_size(root
->fs_info
->super_copy
);
533 u64 end_byte
= bytenr
+ len
;
534 u32 blocksize_bits
= root
->fs_info
->sb
->s_blocksize_bits
;
536 leaf
= path
->nodes
[0];
537 csum_end
= btrfs_item_size_nr(leaf
, path
->slots
[0]) / csum_size
;
538 csum_end
<<= root
->fs_info
->sb
->s_blocksize_bits
;
539 csum_end
+= key
->offset
;
541 if (key
->offset
< bytenr
&& csum_end
<= end_byte
) {
546 * A simple truncate off the end of the item
548 u32 new_size
= (bytenr
- key
->offset
) >> blocksize_bits
;
549 new_size
*= csum_size
;
550 btrfs_truncate_item(root
, path
, new_size
, 1);
551 } else if (key
->offset
>= bytenr
&& csum_end
> end_byte
&&
552 end_byte
> key
->offset
) {
557 * we need to truncate from the beginning of the csum
559 u32 new_size
= (csum_end
- end_byte
) >> blocksize_bits
;
560 new_size
*= csum_size
;
562 btrfs_truncate_item(root
, path
, new_size
, 0);
564 key
->offset
= end_byte
;
565 btrfs_set_item_key_safe(root
, path
, key
);
572 * deletes the csum items from the csum tree for a given
575 int btrfs_del_csums(struct btrfs_trans_handle
*trans
,
576 struct btrfs_root
*root
, u64 bytenr
, u64 len
)
578 struct btrfs_path
*path
;
579 struct btrfs_key key
;
580 u64 end_byte
= bytenr
+ len
;
582 struct extent_buffer
*leaf
;
584 u16 csum_size
= btrfs_super_csum_size(root
->fs_info
->super_copy
);
585 int blocksize_bits
= root
->fs_info
->sb
->s_blocksize_bits
;
587 root
= root
->fs_info
->csum_root
;
589 path
= btrfs_alloc_path();
594 key
.objectid
= BTRFS_EXTENT_CSUM_OBJECTID
;
595 key
.offset
= end_byte
- 1;
596 key
.type
= BTRFS_EXTENT_CSUM_KEY
;
598 path
->leave_spinning
= 1;
599 ret
= btrfs_search_slot(trans
, root
, &key
, path
, -1, 1);
601 if (path
->slots
[0] == 0)
604 } else if (ret
< 0) {
608 leaf
= path
->nodes
[0];
609 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
611 if (key
.objectid
!= BTRFS_EXTENT_CSUM_OBJECTID
||
612 key
.type
!= BTRFS_EXTENT_CSUM_KEY
) {
616 if (key
.offset
>= end_byte
)
619 csum_end
= btrfs_item_size_nr(leaf
, path
->slots
[0]) / csum_size
;
620 csum_end
<<= blocksize_bits
;
621 csum_end
+= key
.offset
;
623 /* this csum ends before we start, we're done */
624 if (csum_end
<= bytenr
)
627 /* delete the entire item, it is inside our range */
628 if (key
.offset
>= bytenr
&& csum_end
<= end_byte
) {
629 ret
= btrfs_del_item(trans
, root
, path
);
632 if (key
.offset
== bytenr
)
634 } else if (key
.offset
< bytenr
&& csum_end
> end_byte
) {
635 unsigned long offset
;
636 unsigned long shift_len
;
637 unsigned long item_offset
;
642 * Our bytes are in the middle of the csum,
643 * we need to split this item and insert a new one.
645 * But we can't drop the path because the
646 * csum could change, get removed, extended etc.
648 * The trick here is the max size of a csum item leaves
649 * enough room in the tree block for a single
650 * item header. So, we split the item in place,
651 * adding a new header pointing to the existing
652 * bytes. Then we loop around again and we have
653 * a nicely formed csum item that we can neatly
656 offset
= (bytenr
- key
.offset
) >> blocksize_bits
;
659 shift_len
= (len
>> blocksize_bits
) * csum_size
;
661 item_offset
= btrfs_item_ptr_offset(leaf
,
664 memset_extent_buffer(leaf
, 0, item_offset
+ offset
,
669 * btrfs_split_item returns -EAGAIN when the
670 * item changed size or key
672 ret
= btrfs_split_item(trans
, root
, path
, &key
, offset
);
673 if (ret
&& ret
!= -EAGAIN
) {
674 btrfs_abort_transaction(trans
, root
, ret
);
678 key
.offset
= end_byte
- 1;
680 truncate_one_csum(root
, path
, &key
, bytenr
, len
);
681 if (key
.offset
< bytenr
)
684 btrfs_release_path(path
);
688 btrfs_free_path(path
);
692 int btrfs_csum_file_blocks(struct btrfs_trans_handle
*trans
,
693 struct btrfs_root
*root
,
694 struct btrfs_ordered_sum
*sums
)
696 struct btrfs_key file_key
;
697 struct btrfs_key found_key
;
698 struct btrfs_path
*path
;
699 struct btrfs_csum_item
*item
;
700 struct btrfs_csum_item
*item_end
;
701 struct extent_buffer
*leaf
= NULL
;
711 u16 csum_size
= btrfs_super_csum_size(root
->fs_info
->super_copy
);
713 path
= btrfs_alloc_path();
717 next_offset
= (u64
)-1;
719 bytenr
= sums
->bytenr
+ total_bytes
;
720 file_key
.objectid
= BTRFS_EXTENT_CSUM_OBJECTID
;
721 file_key
.offset
= bytenr
;
722 btrfs_set_key_type(&file_key
, BTRFS_EXTENT_CSUM_KEY
);
724 item
= btrfs_lookup_csum(trans
, root
, path
, bytenr
, 1);
727 leaf
= path
->nodes
[0];
728 item_end
= btrfs_item_ptr(leaf
, path
->slots
[0],
729 struct btrfs_csum_item
);
730 item_end
= (struct btrfs_csum_item
*)((char *)item_end
+
731 btrfs_item_size_nr(leaf
, path
->slots
[0]));
735 if (ret
!= -EFBIG
&& ret
!= -ENOENT
)
740 /* we found one, but it isn't big enough yet */
741 leaf
= path
->nodes
[0];
742 item_size
= btrfs_item_size_nr(leaf
, path
->slots
[0]);
743 if ((item_size
/ csum_size
) >=
744 MAX_CSUM_ITEMS(root
, csum_size
)) {
745 /* already at max size, make a new one */
749 int slot
= path
->slots
[0] + 1;
750 /* we didn't find a csum item, insert one */
751 nritems
= btrfs_header_nritems(path
->nodes
[0]);
752 if (path
->slots
[0] >= nritems
- 1) {
753 ret
= btrfs_next_leaf(root
, path
);
760 btrfs_item_key_to_cpu(path
->nodes
[0], &found_key
, slot
);
761 if (found_key
.objectid
!= BTRFS_EXTENT_CSUM_OBJECTID
||
762 found_key
.type
!= BTRFS_EXTENT_CSUM_KEY
) {
766 next_offset
= found_key
.offset
;
772 * at this point, we know the tree has an item, but it isn't big
773 * enough yet to put our csum in. Grow it
775 btrfs_release_path(path
);
776 ret
= btrfs_search_slot(trans
, root
, &file_key
, path
,
782 if (path
->slots
[0] == 0)
787 leaf
= path
->nodes
[0];
788 btrfs_item_key_to_cpu(leaf
, &found_key
, path
->slots
[0]);
789 csum_offset
= (bytenr
- found_key
.offset
) >>
790 root
->fs_info
->sb
->s_blocksize_bits
;
792 if (btrfs_key_type(&found_key
) != BTRFS_EXTENT_CSUM_KEY
||
793 found_key
.objectid
!= BTRFS_EXTENT_CSUM_OBJECTID
||
794 csum_offset
>= MAX_CSUM_ITEMS(root
, csum_size
)) {
798 if (csum_offset
== btrfs_item_size_nr(leaf
, path
->slots
[0]) /
805 if (btrfs_leaf_free_space(root
, leaf
) <
806 sizeof(struct btrfs_item
) + csum_size
* 2)
809 free_space
= btrfs_leaf_free_space(root
, leaf
) -
810 sizeof(struct btrfs_item
) - csum_size
;
811 tmp
= sums
->len
- total_bytes
;
812 tmp
>>= root
->fs_info
->sb
->s_blocksize_bits
;
815 extend_nr
= max_t(int, 1, (int)tmp
);
816 diff
= (csum_offset
+ extend_nr
) * csum_size
;
817 diff
= min(diff
, MAX_CSUM_ITEMS(root
, csum_size
) * csum_size
);
819 diff
= diff
- btrfs_item_size_nr(leaf
, path
->slots
[0]);
820 diff
= min(free_space
, diff
);
824 btrfs_extend_item(root
, path
, diff
);
830 btrfs_release_path(path
);
835 tmp
= sums
->len
- total_bytes
;
836 tmp
>>= root
->fs_info
->sb
->s_blocksize_bits
;
837 tmp
= min(tmp
, (next_offset
- file_key
.offset
) >>
838 root
->fs_info
->sb
->s_blocksize_bits
);
840 tmp
= max((u64
)1, tmp
);
841 tmp
= min(tmp
, (u64
)MAX_CSUM_ITEMS(root
, csum_size
));
842 ins_size
= csum_size
* tmp
;
844 ins_size
= csum_size
;
846 path
->leave_spinning
= 1;
847 ret
= btrfs_insert_empty_item(trans
, root
, path
, &file_key
,
849 path
->leave_spinning
= 0;
852 if (WARN_ON(ret
!= 0))
854 leaf
= path
->nodes
[0];
856 item
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_csum_item
);
857 item_end
= (struct btrfs_csum_item
*)((unsigned char *)item
+
858 btrfs_item_size_nr(leaf
, path
->slots
[0]));
859 item
= (struct btrfs_csum_item
*)((unsigned char *)item
+
860 csum_offset
* csum_size
);
862 ins_size
= (u32
)(sums
->len
- total_bytes
) >>
863 root
->fs_info
->sb
->s_blocksize_bits
;
864 ins_size
*= csum_size
;
865 ins_size
= min_t(u32
, (unsigned long)item_end
- (unsigned long)item
,
867 write_extent_buffer(leaf
, sums
->sums
+ index
, (unsigned long)item
,
870 ins_size
/= csum_size
;
871 total_bytes
+= ins_size
* root
->sectorsize
;
874 btrfs_mark_buffer_dirty(path
->nodes
[0]);
875 if (total_bytes
< sums
->len
) {
876 btrfs_release_path(path
);
881 btrfs_free_path(path
);