hi…
i have implemented a file system redirector that redirects a request from a
mapped drive to a real
volume(local drives).
Now we want to redirect the request to a network drive
through a mapped drive( which of course maps to a network drive 
)
In order to do so…the ZwCreateFile converts the network filepath
as \??\UNC\Server\Share\File1.c<file:>in
our file system redirector.
When the request is IRP_MJ_WRITE i use ZwReadFile on the same file handle to
read some data before actually doing ZwWriteFile !
ZwReadFile & ZwWrite is successful on IRP_MJ_READ and IRP_MJ_WRITE request
respectively.
But when the request is IRP_MJ_WRITE, ZwReadFile fails on the same handle(
that i do to read some data from the same file i.e. File1.c ).
The error is STATUS_ACCESS_DENIED(Status = C0000022) while doing ZwReadFile.
Also file path returned is null if the shared folder of a mapped drive is
accessed through a remote machine.
Any clue on whats goin on !
Thanks !</file:>