Copyout to XIO

[Eric Jacobs <eric@xxxxxxxxxxx>]

Hi,

I have a question regarding the use of XIO's. It seems that XIO's let
a thread without process context read another processes's user buffer
(which should be very handy), but there doesn't seem to be a way for
that thread to write back into the process's address space, unless 
that process happens to be switched in and we use copyout() the old
fashioned way.

How would a new-style device driver or filesystem implement READ for
a user process from within its own thread?

Thanks,
Eric