Watchdogs - Extending the UNIX File System
Brian N. Bershad, C. Brian Pinkerton · 1988
ABSTRACT: The traditional UNIX file system provides operations whose semantics are fixed at file system implementation time. Watchdogs are userlevel processes that can extend the ûle system to achieve user-defrned file system semantics on a perfrle basis. Watchdogs provide only those functions that need special handling. Other operations proceed through the normal file system, unimpeded by the existence of watchdogs. We describe a prototype implementation of watchdogs that has been used to build several useful applications. Although only a prototype, the system has acceptable performance. This work took place while the authors were supported by NSF Grants No. DCR-8420945 and CCR-86 I I 390. Bershad was also supported by a USENIX Association