FIFS: A Framework for Implementing User-Mode File Systems in Windows NT

This paper presents FIFS, a framework that facilitates file system research under Windows NT. FIFS addresses the high cost of file system development under Windows NT by providing a simple user-mode development environment. The environment is a Common Internet File System (CIFS) loopback server that seamlessly integrates with NT's Installable File System (IFS) architecture via the CIFS client included in the operating system. As such, it can provide full NT remote file system semantics. Initial performance measurements of the prototype FIFS implementation show FIFS capable of achieving good performance. Our prototype non-caching user-mode NFS implementation performs at about 70% the speed of a commercial non-caching kernel-mode NFS implementation.