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"
26 #include "print-tree.h"
28 #define __MAX_CSUM_ITEMS(r, size) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \
29 sizeof(struct btrfs_item) * 2) / \
32 #define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \
35 #define MAX_ORDERED_SUM_BYTES(r) ((PAGE_SIZE - \
36 sizeof(struct btrfs_ordered_sum)) / \
37 sizeof(struct btrfs_sector_sum) * \
38 (r)->sectorsize - (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 struct btrfs_csum_item *btrfs_lookup_csum(struct btrfs_trans_handle *trans,
87 struct btrfs_root *root,
88 struct btrfs_path *path,
92 struct btrfs_key file_key;
93 struct btrfs_key found_key;
94 struct btrfs_csum_item *item;
95 struct extent_buffer *leaf;
97 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
100 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
101 file_key.offset = bytenr;
102 btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
103 ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
106 leaf = path->nodes[0];
109 if (path->slots[0] == 0)
112 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
113 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY)
116 csum_offset = (bytenr - found_key.offset) >>
117 root->fs_info->sb->s_blocksize_bits;
118 csums_in_item = btrfs_item_size_nr(leaf, path->slots[0]);
119 csums_in_item /= csum_size;
121 if (csum_offset >= csums_in_item) {
126 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
127 item = (struct btrfs_csum_item *)((unsigned char *)item +
128 csum_offset * csum_size);
136 int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
137 struct btrfs_root *root,
138 struct btrfs_path *path, u64 objectid,
142 struct btrfs_key file_key;
143 int ins_len = mod < 0 ? -1 : 0;
146 file_key.objectid = objectid;
147 file_key.offset = offset;
148 btrfs_set_key_type(&file_key, BTRFS_EXTENT_DATA_KEY);
149 ret = btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
153 u64 btrfs_file_extent_length(struct btrfs_path *path)
156 struct btrfs_file_extent_item *fi;
159 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
160 struct btrfs_file_extent_item);
161 extent_type = btrfs_file_extent_type(path->nodes[0], fi);
163 if (extent_type == BTRFS_FILE_EXTENT_REG ||
164 extent_type == BTRFS_FILE_EXTENT_PREALLOC)
165 len = btrfs_file_extent_num_bytes(path->nodes[0], fi);
166 else if (extent_type == BTRFS_FILE_EXTENT_INLINE)
167 len = btrfs_file_extent_inline_len(path->nodes[0], fi);
174 static int __btrfs_lookup_bio_sums(struct btrfs_root *root,
175 struct inode *inode, struct bio *bio,
176 u64 logical_offset, u32 *dst, int dio)
179 struct bio_vec *bvec = bio->bi_io_vec;
182 u64 item_start_offset = 0;
183 u64 item_last_offset = 0;
186 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
188 struct btrfs_path *path;
189 struct btrfs_csum_item *item = NULL;
190 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
192 path = btrfs_alloc_path();
195 if (bio->bi_size > PAGE_CACHE_SIZE * 8)
198 WARN_ON(bio->bi_vcnt <= 0);
201 * the free space stuff is only read when it hasn't been
202 * updated in the current transaction. So, we can safely
203 * read from the commit root and sidestep a nasty deadlock
204 * between reading the free space cache and updating the csum tree.
206 if (btrfs_is_free_space_inode(inode)) {
207 path->search_commit_root = 1;
208 path->skip_locking = 1;
211 disk_bytenr = (u64)bio->bi_sector << 9;
213 offset = logical_offset;
214 while (bio_index < bio->bi_vcnt) {
216 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
217 ret = btrfs_find_ordered_sum(inode, offset, disk_bytenr, &sum);
221 if (!item || disk_bytenr < item_start_offset ||
222 disk_bytenr >= item_last_offset) {
223 struct btrfs_key found_key;
227 btrfs_release_path(path);
228 item = btrfs_lookup_csum(NULL, root->fs_info->csum_root,
229 path, disk_bytenr, 0);
232 if (ret == -ENOENT || ret == -EFBIG)
235 if (BTRFS_I(inode)->root->root_key.objectid ==
236 BTRFS_DATA_RELOC_TREE_OBJECTID) {
237 set_extent_bits(io_tree, offset,
238 offset + bvec->bv_len - 1,
239 EXTENT_NODATASUM, GFP_NOFS);
241 printk(KERN_INFO "btrfs no csum found "
242 "for inode %llu start %llu\n",
245 (unsigned long long)offset);
248 btrfs_release_path(path);
251 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
254 item_start_offset = found_key.offset;
255 item_size = btrfs_item_size_nr(path->nodes[0],
257 item_last_offset = item_start_offset +
258 (item_size / csum_size) *
260 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
261 struct btrfs_csum_item);
264 * this byte range must be able to fit inside
265 * a single leaf so it will also fit inside a u32
267 diff = disk_bytenr - item_start_offset;
268 diff = diff / root->sectorsize;
269 diff = diff * csum_size;
271 read_extent_buffer(path->nodes[0], &sum,
272 ((unsigned long)item) + diff,
278 set_state_private(io_tree, offset, sum);
279 disk_bytenr += bvec->bv_len;
280 offset += bvec->bv_len;
284 btrfs_free_path(path);
288 int btrfs_lookup_bio_sums(struct btrfs_root *root, struct inode *inode,
289 struct bio *bio, u32 *dst)
291 return __btrfs_lookup_bio_sums(root, inode, bio, 0, dst, 0);
294 int btrfs_lookup_bio_sums_dio(struct btrfs_root *root, struct inode *inode,
295 struct bio *bio, u64 offset)
297 return __btrfs_lookup_bio_sums(root, inode, bio, offset, NULL, 1);
300 int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
301 struct list_head *list, int search_commit)
303 struct btrfs_key key;
304 struct btrfs_path *path;
305 struct extent_buffer *leaf;
306 struct btrfs_ordered_sum *sums;
307 struct btrfs_sector_sum *sector_sum;
308 struct btrfs_csum_item *item;
310 unsigned long offset;
314 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
316 path = btrfs_alloc_path();
321 path->skip_locking = 1;
323 path->search_commit_root = 1;
326 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
328 key.type = BTRFS_EXTENT_CSUM_KEY;
330 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
333 if (ret > 0 && path->slots[0] > 0) {
334 leaf = path->nodes[0];
335 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
336 if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
337 key.type == BTRFS_EXTENT_CSUM_KEY) {
338 offset = (start - key.offset) >>
339 root->fs_info->sb->s_blocksize_bits;
340 if (offset * csum_size <
341 btrfs_item_size_nr(leaf, path->slots[0] - 1))
346 while (start <= end) {
347 leaf = path->nodes[0];
348 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
349 ret = btrfs_next_leaf(root, path);
354 leaf = path->nodes[0];
357 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
358 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
359 key.type != BTRFS_EXTENT_CSUM_KEY)
362 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
363 if (key.offset > end)
366 if (key.offset > start)
369 size = btrfs_item_size_nr(leaf, path->slots[0]);
370 csum_end = key.offset + (size / csum_size) * root->sectorsize;
371 if (csum_end <= start) {
376 csum_end = min(csum_end, end + 1);
377 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
378 struct btrfs_csum_item);
379 while (start < csum_end) {
380 size = min_t(size_t, csum_end - start,
381 MAX_ORDERED_SUM_BYTES(root));
382 sums = kzalloc(btrfs_ordered_sum_size(root, size),
389 sector_sum = sums->sums;
390 sums->bytenr = start;
393 offset = (start - key.offset) >>
394 root->fs_info->sb->s_blocksize_bits;
398 read_extent_buffer(path->nodes[0],
400 ((unsigned long)item) +
402 sector_sum->bytenr = start;
404 size -= root->sectorsize;
405 start += root->sectorsize;
409 list_add_tail(&sums->list, &tmplist);
415 while (ret < 0 && !list_empty(&tmplist)) {
416 sums = list_entry(&tmplist, struct btrfs_ordered_sum, list);
417 list_del(&sums->list);
420 list_splice_tail(&tmplist, list);
422 btrfs_free_path(path);
426 int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode,
427 struct bio *bio, u64 file_start, int contig)
429 struct btrfs_ordered_sum *sums;
430 struct btrfs_sector_sum *sector_sum;
431 struct btrfs_ordered_extent *ordered;
433 struct bio_vec *bvec = bio->bi_io_vec;
435 unsigned long total_bytes = 0;
436 unsigned long this_sum_bytes = 0;
440 WARN_ON(bio->bi_vcnt <= 0);
441 sums = kzalloc(btrfs_ordered_sum_size(root, bio->bi_size), GFP_NOFS);
445 sector_sum = sums->sums;
446 disk_bytenr = (u64)bio->bi_sector << 9;
447 sums->len = bio->bi_size;
448 INIT_LIST_HEAD(&sums->list);
453 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
455 ordered = btrfs_lookup_ordered_extent(inode, offset);
456 BUG_ON(!ordered); /* Logic error */
457 sums->bytenr = ordered->start;
459 while (bio_index < bio->bi_vcnt) {
461 offset = page_offset(bvec->bv_page) + bvec->bv_offset;
463 if (!contig && (offset >= ordered->file_offset + ordered->len ||
464 offset < ordered->file_offset)) {
465 unsigned long bytes_left;
466 sums->len = this_sum_bytes;
468 btrfs_add_ordered_sum(inode, ordered, sums);
469 btrfs_put_ordered_extent(ordered);
471 bytes_left = bio->bi_size - total_bytes;
473 sums = kzalloc(btrfs_ordered_sum_size(root, bytes_left),
475 BUG_ON(!sums); /* -ENOMEM */
476 sector_sum = sums->sums;
477 sums->len = bytes_left;
478 ordered = btrfs_lookup_ordered_extent(inode, offset);
479 BUG_ON(!ordered); /* Logic error */
480 sums->bytenr = ordered->start;
483 data = kmap_atomic(bvec->bv_page);
484 sector_sum->sum = ~(u32)0;
485 sector_sum->sum = btrfs_csum_data(root,
486 data + bvec->bv_offset,
490 btrfs_csum_final(sector_sum->sum,
491 (char *)§or_sum->sum);
492 sector_sum->bytenr = disk_bytenr;
496 total_bytes += bvec->bv_len;
497 this_sum_bytes += bvec->bv_len;
498 disk_bytenr += bvec->bv_len;
499 offset += bvec->bv_len;
503 btrfs_add_ordered_sum(inode, ordered, sums);
504 btrfs_put_ordered_extent(ordered);
509 * helper function for csum removal, this expects the
510 * key to describe the csum pointed to by the path, and it expects
511 * the csum to overlap the range [bytenr, len]
513 * The csum should not be entirely contained in the range and the
514 * range should not be entirely contained in the csum.
516 * This calls btrfs_truncate_item with the correct args based on the
517 * overlap, and fixes up the key as required.
519 static noinline void truncate_one_csum(struct btrfs_trans_handle *trans,
520 struct btrfs_root *root,
521 struct btrfs_path *path,
522 struct btrfs_key *key,
525 struct extent_buffer *leaf;
526 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
528 u64 end_byte = bytenr + len;
529 u32 blocksize_bits = root->fs_info->sb->s_blocksize_bits;
531 leaf = path->nodes[0];
532 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
533 csum_end <<= root->fs_info->sb->s_blocksize_bits;
534 csum_end += key->offset;
536 if (key->offset < bytenr && csum_end <= end_byte) {
541 * A simple truncate off the end of the item
543 u32 new_size = (bytenr - key->offset) >> blocksize_bits;
544 new_size *= csum_size;
545 btrfs_truncate_item(trans, root, path, new_size, 1);
546 } else if (key->offset >= bytenr && csum_end > end_byte &&
547 end_byte > key->offset) {
552 * we need to truncate from the beginning of the csum
554 u32 new_size = (csum_end - end_byte) >> blocksize_bits;
555 new_size *= csum_size;
557 btrfs_truncate_item(trans, root, path, new_size, 0);
559 key->offset = end_byte;
560 btrfs_set_item_key_safe(trans, root, path, key);
567 * deletes the csum items from the csum tree for a given
570 int btrfs_del_csums(struct btrfs_trans_handle *trans,
571 struct btrfs_root *root, u64 bytenr, u64 len)
573 struct btrfs_path *path;
574 struct btrfs_key key;
575 u64 end_byte = bytenr + len;
577 struct extent_buffer *leaf;
579 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
580 int blocksize_bits = root->fs_info->sb->s_blocksize_bits;
582 root = root->fs_info->csum_root;
584 path = btrfs_alloc_path();
589 key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
590 key.offset = end_byte - 1;
591 key.type = BTRFS_EXTENT_CSUM_KEY;
593 path->leave_spinning = 1;
594 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
596 if (path->slots[0] == 0)
599 } else if (ret < 0) {
603 leaf = path->nodes[0];
604 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
606 if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
607 key.type != BTRFS_EXTENT_CSUM_KEY) {
611 if (key.offset >= end_byte)
614 csum_end = btrfs_item_size_nr(leaf, path->slots[0]) / csum_size;
615 csum_end <<= blocksize_bits;
616 csum_end += key.offset;
618 /* this csum ends before we start, we're done */
619 if (csum_end <= bytenr)
622 /* delete the entire item, it is inside our range */
623 if (key.offset >= bytenr && csum_end <= end_byte) {
624 ret = btrfs_del_item(trans, root, path);
627 if (key.offset == bytenr)
629 } else if (key.offset < bytenr && csum_end > end_byte) {
630 unsigned long offset;
631 unsigned long shift_len;
632 unsigned long item_offset;
637 * Our bytes are in the middle of the csum,
638 * we need to split this item and insert a new one.
640 * But we can't drop the path because the
641 * csum could change, get removed, extended etc.
643 * The trick here is the max size of a csum item leaves
644 * enough room in the tree block for a single
645 * item header. So, we split the item in place,
646 * adding a new header pointing to the existing
647 * bytes. Then we loop around again and we have
648 * a nicely formed csum item that we can neatly
651 offset = (bytenr - key.offset) >> blocksize_bits;
654 shift_len = (len >> blocksize_bits) * csum_size;
656 item_offset = btrfs_item_ptr_offset(leaf,
659 memset_extent_buffer(leaf, 0, item_offset + offset,
664 * btrfs_split_item returns -EAGAIN when the
665 * item changed size or key
667 ret = btrfs_split_item(trans, root, path, &key, offset);
668 if (ret && ret != -EAGAIN) {
669 btrfs_abort_transaction(trans, root, ret);
673 key.offset = end_byte - 1;
675 truncate_one_csum(trans, root, path, &key, bytenr, len);
676 if (key.offset < bytenr)
679 btrfs_release_path(path);
683 btrfs_free_path(path);
687 int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
688 struct btrfs_root *root,
689 struct btrfs_ordered_sum *sums)
693 struct btrfs_key file_key;
694 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;
703 struct btrfs_sector_sum *sector_sum;
706 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
708 path = btrfs_alloc_path();
712 sector_sum = sums->sums;
713 trans->adding_csums = 1;
715 next_offset = (u64)-1;
717 file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
718 file_key.offset = sector_sum->bytenr;
719 bytenr = sector_sum->bytenr;
720 btrfs_set_key_type(&file_key, BTRFS_EXTENT_CSUM_KEY);
722 item = btrfs_lookup_csum(trans, root, path, sector_sum->bytenr, 1);
724 leaf = path->nodes[0];
729 if (ret != -EFBIG && ret != -ENOENT)
734 /* we found one, but it isn't big enough yet */
735 leaf = path->nodes[0];
736 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
737 if ((item_size / csum_size) >=
738 MAX_CSUM_ITEMS(root, csum_size)) {
739 /* already at max size, make a new one */
743 int slot = path->slots[0] + 1;
744 /* we didn't find a csum item, insert one */
745 nritems = btrfs_header_nritems(path->nodes[0]);
746 if (path->slots[0] >= nritems - 1) {
747 ret = btrfs_next_leaf(root, path);
754 btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
755 if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
756 found_key.type != BTRFS_EXTENT_CSUM_KEY) {
760 next_offset = found_key.offset;
766 * at this point, we know the tree has an item, but it isn't big
767 * enough yet to put our csum in. Grow it
769 btrfs_release_path(path);
770 ret = btrfs_search_slot(trans, root, &file_key, path,
776 if (path->slots[0] == 0)
781 leaf = path->nodes[0];
782 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
783 csum_offset = (bytenr - found_key.offset) >>
784 root->fs_info->sb->s_blocksize_bits;
786 if (btrfs_key_type(&found_key) != BTRFS_EXTENT_CSUM_KEY ||
787 found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
788 csum_offset >= MAX_CSUM_ITEMS(root, csum_size)) {
792 if (csum_offset >= btrfs_item_size_nr(leaf, path->slots[0]) /
794 u32 diff = (csum_offset + 1) * csum_size;
797 * is the item big enough already? we dropped our lock
798 * before and need to recheck
800 if (diff < btrfs_item_size_nr(leaf, path->slots[0]))
803 diff = diff - btrfs_item_size_nr(leaf, path->slots[0]);
804 if (diff != csum_size)
807 btrfs_extend_item(trans, root, path, diff);
812 btrfs_release_path(path);
815 u64 tmp = total_bytes + root->sectorsize;
816 u64 next_sector = sector_sum->bytenr;
817 struct btrfs_sector_sum *next = sector_sum + 1;
819 while (tmp < sums->len) {
820 if (next_sector + root->sectorsize != next->bytenr)
822 tmp += root->sectorsize;
823 next_sector = next->bytenr;
826 tmp = min(tmp, next_offset - file_key.offset);
827 tmp >>= root->fs_info->sb->s_blocksize_bits;
828 tmp = max((u64)1, tmp);
829 tmp = min(tmp, (u64)MAX_CSUM_ITEMS(root, csum_size));
830 ins_size = csum_size * tmp;
832 ins_size = csum_size;
834 path->leave_spinning = 1;
835 ret = btrfs_insert_empty_item(trans, root, path, &file_key,
837 path->leave_spinning = 0;
845 leaf = path->nodes[0];
846 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
848 item = (struct btrfs_csum_item *)((unsigned char *)item +
849 csum_offset * csum_size);
851 item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
852 item_end = (struct btrfs_csum_item *)((unsigned char *)item_end +
853 btrfs_item_size_nr(leaf, path->slots[0]));
856 write_extent_buffer(leaf, §or_sum->sum, (unsigned long)item, csum_size);
858 total_bytes += root->sectorsize;
860 if (total_bytes < sums->len) {
861 item = (struct btrfs_csum_item *)((char *)item +
863 if (item < item_end && bytenr + PAGE_CACHE_SIZE ==
864 sector_sum->bytenr) {
865 bytenr = sector_sum->bytenr;
870 btrfs_mark_buffer_dirty(path->nodes[0]);
871 if (total_bytes < sums->len) {
872 btrfs_release_path(path);
877 trans->adding_csums = 0;
878 btrfs_free_path(path);