  Virtual file systems are a tool to centralize and mobilize a file system that
could otherwise be complex and consist of multiple hierarchies, hard disks, and
more. In this paper, we discuss the design of Unix-based file systems and how
this type of file system layout using inode data structures and a disk emulator
can be implemented as a single-file virtual file system in Linux. We explore
the ways that virtual file systems are vulnerable to security attacks and
introduce straightforward solutions that can be implemented to help prevent or
mitigate the consequences of such attacks.
