Filesystem is small aspect here, the big deal here is putting stuff like task scheduling and IPC on top of DBMS. And even for files, the point here is more on having distributed filesystem as first-class citizen and less on being able to do sql-like queries.
Although not the same as what the paper talks about, an approximation would be Oracle running with raw volumes managed by the DB, on a cluster, using Web based UIs done on Apex.
