glusterfs --negative-timeout=N should enable negative entry caching ability of FUSE
CHANGE: http://review.gluster.com/3696 (fuse-bridge: expose negative entry caching of FUSE) merged in master by Anand Avati (avati)
CHANGE: http://review.gluster.com/3697 (libglusterfs/options: enable validator macros for type 'double') merged in master by Anand Avati (avati)
CHANGE: http://review.gluster.com/3698 (fuse-bridge: utilize the option handle framework for double) merged in master by Anand Avati (avati)