Filesystems in Linux
Linux supports a wide range of filesystems, from native filesystems, such as ext2 and ext3, to networked filesystems, such as NFS and Codamore than 50 filesystems alone in the official kernel. The VFS layer provides these disparate filesystems with both a framework for their implementation and an interface for working with the standard system calls. The VFS layer, thus, both makes it clean to implement new filesystems in Linux and allows those filesystems to automatically interoperate via the standard Unix system calls.
This chapter described the purpose of the VFS and discussed its various data structures, including the all-important inode, dentry, and superblock objects. The next chapter, "The Block I/O Layer," discusses how data physically ends up in a filesystem.