Notes Linux kernel Learning (10) virtual file system concept

Virtual file system

Virtual file system: The kernel subsystem VFS,VFS is the abstraction layer of the file system in the kernel, and provides the file system related interface for the user space;

With a virtual file system, programs can interact and operate in different file systems using standard Linux file system calls.

VFS as an abstraction layer:

　　　　

The file system is installed on a specific installation point, which is called a namespace in the global hierarchy.

All installed file systems are present in the system as branches of the root file system tree.

　　　　　

File System main objects:

Super Block object: Represents an installed file system; struct Super_block {}

Index Node object: represents a file; struct Inode {}

Catalog Item Object: Represents a directory entry, a component of a path; struct Dentry {}

File object: Process open file; struct file {}

Specific file system type: struct File_system_type {}

Installing the file System instance: struct Vfsmount {}

The structure relationships between objects are as follows:

　　　　

The VFS file system mechanism in Linux:

https://www.ibm.com/developerworks/cn/linux/l-vfs/

Notes Linux kernel Learning (10) virtual file system concept