What Is Linux VFS?

Linux VFS is the Linux Virtual File System. It is designed around the object oriented concepts. It has two main components; these are a set of the definitions that define what a file object is allowed to look like and a layer of software to manipulate those objects. The three significant object types defined by the VFS are the inode-object and file object structures, which represent the individual files, and the file system object that represents an entire file system.

For each these three types of object; VFS defines a set of operations that must be implemented by that structure. Every object of one of these types contains pointer to the function table. The function table lists the addresses of actual functions that implement those operations for that particular object. Thus the VFS software layer can perform an operation on one of these objects by calling appropriate function from that object's function table, without having to know in advance exactly with what kind of object it is dealing.  

The VFS does not know whether an inode represents a networked file, a disk file, a network socket, or the directory file; the appropriate function for that file's read data operation will always be at the same place in its function table and VFS software layer will call that function without caring how the data are actually read.