os/FileStore: use generic KeyValueDB::create()

Signed-off-by: Sage Weil <sage@inktank.com>
add rocksdb support

Signed-off-by: xinxin shu <xinxin.shu@intel.com>
add rocksdb submodule
get a stable version (3.0) of rocksdb

Signed-off-by: xinxin shu <xinxin.shu@intel.com>
add --with-librocksdb-static configure options

with this options, ceph will build rocksdb from submodule

Signed-off-by: xinxin shu <xinxin.shu@intel.com>
add support for rocksdb as data store

Signed-off-by: xinxin shu <xinxin.shu@intel.com>
rocksdb backend optimization

Signed-off-by: xinxin shu <xinxin.shu@intel.com>