tree c86f41730d37a0f1424ee5c0cdb9c9017121d6d0
parent 3bd6ad7b688e200ac7633b16affa164d7cd5ef07
author Jan Kara <jack@suse.cz> 1457495090 -0500
committer Theodore Ts'o <tytso@mit.edu> 1457495090 -0500

ext4: use i_mutex to serialize unaligned AIO DIO

Currently we've used hashed aio_mutex to serialize unaligned AIO DIO.
However the code cleanups that happened after 2011 when the lock was
introduced made aio_mutex acquired at almost the same places where we
already have exclusion using i_mutex. So just use i_mutex for the
exclusion of unaligned AIO DIO.

The change moves waiting for pending unwritten extent conversion under
i_mutex. That makes special handling of O_APPEND writes unnecessary and
also avoids possible livelocking of unaligned AIO DIO with aligned one
(nothing was preventing contiguous stream of aligned AIO DIOs to let
unaligned AIO DIO wait forever).

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>