Commit 11d33ab6 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by David Sterba
Browse files

btrfs: simplify splitting logic in btrfs_extract_ordered_extent 



btrfs_extract_ordered_extent is always used to split an ordered_extent
and extent_map into two parts, so it doesn't need to deal with a three
way split.

Simplify it by only allowing for a single split point, and always split
out the beginning of the extent, as that is what we'll later need to
be able to hold on to a reference to the original ordered_extent that
the first part is split off for submission.

Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Tested-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent e44ca71c

fs/btrfs/inode.c

+13 −16
Original line number Diff line number Diff line
@@ -2632,39 +2632,36 @@ blk_status_t btrfs_extract_ordered_extent(struct btrfs_bio *bbio) 
	u64 len = bbio->bio.bi_iter.bi_size;

	struct btrfs_inode *inode = bbio->inode;

	struct btrfs_ordered_extent *ordered;

	u64 file_len;

	u64 end = start + len;

	u64 ordered_end;

	u64 pre, post;

	u64 ordered_len;

	int ret = 0;



	ordered = btrfs_lookup_ordered_extent(inode, bbio->file_offset);

	if (WARN_ON_ONCE(!ordered))

		return BLK_STS_IOERR;

	ordered_len = ordered->num_bytes;



	/* No need to split */

	if (ordered->disk_num_bytes == len)

	/* Must always be called for the beginning of an ordered extent. */

	if (WARN_ON_ONCE(start != ordered->disk_bytenr)) {

		ret = -EINVAL;

		goto out;

	}



	ordered_end = ordered->disk_bytenr + ordered->disk_num_bytes;

	/* bio must be in one ordered extent */

	if (WARN_ON_ONCE(start < ordered->disk_bytenr || end > ordered_end)) {

	/* The bio must be entirely covered by the ordered extent. */

	if (WARN_ON_ONCE(len > ordered_len)) {

		ret = -EINVAL;

		goto out;

	}



	file_len = ordered->num_bytes;

	pre = start - ordered->disk_bytenr;

	post = ordered_end - end;

	/* No need to split if the ordered extent covers the entire bio. */

	if (ordered->disk_num_bytes == len)

		goto out;



	ret = btrfs_split_ordered_extent(ordered, pre, post);

	ret = btrfs_split_ordered_extent(ordered, len, 0);

	if (ret)

		goto out;

	ret = split_zoned_em(inode, bbio->file_offset, file_len, pre, post);



	ret = split_zoned_em(inode, bbio->file_offset, ordered_len, len, 0);

out:

	btrfs_put_ordered_extent(ordered);



	return errno_to_blk_status(ret);

}