Follow Techotopia on Twitter

On-line Guides
All Guides
eBook Store
iOS / Android
Linux for Beginners
Office Productivity
Linux Installation
Linux Security
Linux Utilities
Linux Virtualization
Linux Kernel
System/Network Admin
Scripting Languages
Development Tools
Web Development
GUI Toolkits/Desktop
Mail Systems
Eclipse Documentation

How To Guides
General System Admin
Linux Security
Linux Filesystems
Web Servers
Graphics & Desktop
PC Hardware
Problem Solutions
Privacy Policy




Writing Device Drivers
Previous Next

File I/O

A file system is a tree-structured hierarchy of directories and files. Some file systems, such as the UNIX File System (UFS), reside on block-oriented devices. File systems are created by format(1M) and newfs(1M).

When an application issues a read(2) or write(2) system call to an ordinary file on the UFS file system, the file system can call the device driver strategy(9E) entry point for the block device on which the file system resides. The file system code can call strategy(9E) several times for a single read(2) or write(2) system call.

The file system code determines the logical device address, or logical block number, for each ordinary file block. A block I/O request is then built in the form of a buf(9S) structure directed at the block device. The driver strategy(9E) entry point then interprets the buf(9S) structure and completes the request.

Previous Next

  Published under the terms fo the Public Documentation License Version 1.01. Design by Interspire