发现两篇很好的文章，给大家分享一下

Introduction

One of the most frequently done tasks in Windows Driver Model (WDM) drivers is sending input/output request packets (IRPs) from one driver to another driver. A driver either creates its own IRP and sends it to a lower driver, or the driver forwards the IRPs that it receives from another driver that is attached above.

This article discusses all the possible ways that a driver can send IRPs to a lower driver with annotated sample code. Depending on the need, driver writers can follow one of the templates given in this article and not be affected by old IRP handling rules.

Part 1 of this subject shows 5 scenarios about how to forward an IRP to another driver from a dispatch routine, and the remaining 7 scenarios (listed in part 2 of this subject) discuss different ways of creating an IRP and sending it to another driver. Part 2 of this subject is contained in the following Knowledge Base article:
326315  (http://support.microsoft.com/kb/326315/ ) Different ways of handling IRPs - cheat sheet (part 2 of 2)

原文地址：
http://support.microsoft.com/kb/320275/en-us
http://support.microsoft.com/kb/326315/en-us