btrfs: use bio::remaining for async checksumming synchronization

We can use bio::remaining counter to sync the offloaded checksumming.
As a result we can slim down the btrfs_bio structure by 24 bytes
and simplify the code a bit.

Difference in pahole output:

-	/* size: 328, cachelines: 6, members: 15 */
+	/* size: 304, cachelines: 5, members: 14 */

Moreover this will allow us enabling async checksumming with encryption
where we need to checksum the bounce bio instead of our regular one
embedded in btrfs_bio. And so we need to extend it's lifetime. This is
the preferred way to do so.

This also fixes a bug in experimental build where the async checksumming
was using the system workqueue instead of fs_info::endio_workers.

Fixes: dd57c78aec39 ("btrfs: introduce btrfs_bio::async_csum")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Daniel Vacek <neelx@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

0 files changed, 0 insertions, 0 deletions