PEPROCESS to PFILE_OBJECT

I am wondering what is the best way to convert a process object pointer over to a file object pointer. I am currently using this method:

1. pass PEPROCESS to ObOpenObjectByPointer to get handle to process
2. call ZwQueryInformationProcess to get ProcessImageFileName
3. call ZwCr开发者_StackOverfloweateFile with ProcessImageFileName to get file handle
4. finally pass file handle to ObReferenceObjectByHandle to get PFILE_OBJECT

Any suggestions?