title: Full file path with drive letter
body: <p>I am a beginner in driver development. I am developing a filter driver(Kernel Mode).
  I want to get the full path of every file which is opened.
  I have a <strong>file object and an IRP</strong>.
  I am using <strong>&amp;pFileObject->fileName</strong> to display the path. It shows the complete path but dose not show drive letter. 
  Kindly provide a kernel level routine which tells the <strong>drive letter</strong>. 
  below is the code</p>
  
  <pre><code>#include "StdAfx.h"
  #include "drv_common.h"
  #include "ntddk.h"
  #include "FsFilter.h"
  
  
  ///////////////////////////////////////////////////////////////////////////////////////////    ////////
  // PassThrough IRP Handler
  
  NTSTATUS FsFilterDispatchPassThrough( __in PDEVICE_OBJECT DeviceObject, __in PIRP Irp )
  {
      PFSFILTER_DEVICE_EXTENSION pDevExt = (PFSFILTER_DEVICE_EXTENSION)DeviceObject-    &gt;DeviceExtension;
  
      IoSkipCurrentIrpStackLocation(Irp);
      return IoCallDriver(pDevExt-&gt;AttachedToDeviceObject, Irp);
  }
  
  ///////////////////////////////////////////////////////////////////////////////////////////    ////////
  // IRP_MJ_CREATE IRP Handler
  
  NTSTATUS FsFilterDispatchCreate(
      __in PDEVICE_OBJECT DeviceObject,
      __in PIRP           Irp
      )
  {
      PFILE_OBJECT pFileObject = IoGetCurrentIrpStackLocation(Irp)-&gt;FileObject;
  
      DbgPrint("%wZ\n", &amp;pFileObject-&gt;FileName);
  
      return FsFilterDispatchPassThrough(DeviceObject, Irp);
  }
  </code></pre>