Enable Ceph client caching support

configname: CONFIG_CEPH_FSCACHE

Linux Kernel Configuration
└─>File systems
└─>Network File Systems
└─>Enable Ceph client caching support
In linux kernel since version 3.12 (release Date: 2013-11-03)  
Choose Y here to enable persistent, read-only local
caching support for Ceph clients using FS-Cache