memory mapped files question

From a user mode process I create a memory mapped file with
CreateFileMapping and I write data in it.How can I see from my filter
driver the data that I wrote ?I notice that the buffer in my FastIO read
callback is not valid (the same thing happend in read callback)

> >From a user mode process I create a memory mapped file with

CreateFileMapping and I write data in it.How can I see from my filter
driver the data that I wrote ?I notice that the buffer in my FastIO read

No FastIO is used for this. This is handled by paging (IRP_PAGING_IO) write
IRPs.

Max