UNIX Filesystems: Evolution, Design, and Implementation

UNIX Kernel Concepts

This chapter covers the earlier versions of UNIX up to 7th Edition and describes the main kernel concepts, with particular reference to the kernel structures related to filesystem activity and how the main file access-based system calls were implemented.

The structures, kernel subsystems, and flow of control through the research edition UNIX kernels are still largely intact after more than 25 years of development. Thus, the simple approaches described in this chapter are definitely a prerequisite to understanding the more complex UNIX implementations found today.