From: Chris Mason <mason@suse.com>

Updates the reiserfs-logging improvements to use schedule_timeout instead of
yield when letting the transaction grow a little before forcing a commit for
fsync/O_SYNC/O_DIRECT.

Also, when one process forces a transaction to end and plans on doing the
commit (like fsync), it sets a flag on the transaction so the journal code
knows not to bother kicking the journal work queue.

queue_delayed_work is used so that if we get a bunch of tiny transactions
ended quickly, we aren't constantly kicking the work queue.

These significantly improve reiserfs performance during fsync heavy
workloads.