ceph: douts

Add douts

Signed-off-by: Alex Elder <elder@inktank.com>
libceph: add barriers for connection flag ops

Barriers are required for those bit operations that don't return
values.  I'm not totally sure from "Documentation/atomic_ops.txt" on
whether test_bit() needs them, so we'll insert one just to be safe.

Signed-off-by: Alex Elder <elder@inktank.com>