bluestore: asyn cdeferred_try_submit deadlock
3 - minor
Pull request ID:
In deferred_aio_finish we may need to requeue pending deferred via a finisher. Currently we reuse finishers0, but that thread may be busy doing completions back into the OSD. deadlock!
2017-08-31 18:00:40.308327 7f6ffd4ca700 20 bluestore(/var/lib/ceph/osd/ceph-4) _deferred_aio_finish queuing async deferred_try_submit
..but not deferred_try_submit call follows.