@VisibleForTesting
  void releaseSessionLockFile() throws IOException {
    if (hdfsSessionPath != null && hdfsSessionPathLockFile != null) {
      hdfsSessionPathLockFile.close();
    }
  }
Create a given path if it doesn't exist.

@param conf
@param path
@param permission
@param isLocal
@param isCleanUp
@return
@throws IOException
ql/src/java/org/apache/hadoop/hive/ql/session/SessionState.java