Commit 6cd7ce49 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by David Sterba
Browse files

btrfs: don't access the bio directly in btrfs_csum_one_bio 



Use bio_for_each_segment_all to iterate over the segments instead.
This requires a bit of reshuffling so that we only lookup up the ordered
item once inside the bio_for_each_segment_all loop.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarOmar Sandoval <osandov@fb.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 6a2de22f

fs/btrfs/file-item.c

+10 −11
Original line number Diff line number Diff line
@@ -447,13 +447,12 @@ int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode, 
		       struct bio *bio, u64 file_start, int contig)

{

	struct btrfs_ordered_sum *sums;

	struct btrfs_ordered_extent *ordered;

	struct btrfs_ordered_extent *ordered = NULL;

	char *data;

	struct bio_vec *bvec = bio->bi_io_vec;

	int bio_index = 0;

	struct bio_vec *bvec;

	int index;

	int nr_sectors;

	int i;

	int i, j;

	unsigned long total_bytes = 0;

	unsigned long this_sum_bytes = 0;

	u64 offset;
@@ -470,17 +469,20 @@ int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode, 
	if (contig)

		offset = file_start;

	else

		offset = page_offset(bvec->bv_page) + bvec->bv_offset;

		offset = 0; /* shut up gcc */



	ordered = btrfs_lookup_ordered_extent(inode, offset);

	BUG_ON(!ordered); /* Logic error */

	sums->bytenr = (u64)bio->bi_iter.bi_sector << 9;

	index = 0;



	while (bio_index < bio->bi_vcnt) {

	bio_for_each_segment_all(bvec, bio, j) {

		if (!contig)

			offset = page_offset(bvec->bv_page) + bvec->bv_offset;



		if (!ordered) {

			ordered = btrfs_lookup_ordered_extent(inode, offset);

			BUG_ON(!ordered); /* Logic error */

		}



		data = kmap_atomic(bvec->bv_page);



		nr_sectors = BTRFS_BYTES_TO_BLKS(root->fs_info,
@@ -529,9 +531,6 @@ int btrfs_csum_one_bio(struct btrfs_root *root, struct inode *inode, 
		}



		kunmap_atomic(data);



		bio_index++;

		bvec++;

	}

	this_sum_bytes = 0;

	btrfs_add_ordered_sum(inode, ordered, sums);