How to force cdrom driver to redetect media after cdrecord?

[Byron Stanoszek <gandalf@winds.org>]

> > I originally thought so, but maybe I was wrong. Jens posted a patch
> > to invalidate kernel buffers on an umount - if the problem persists
> > with that patch, I still believe it is a hardware fault.
>
> Perhaps another program has the device open still? In that case, we
> don't invalidate the toc cache.
>
> --
> Jens Axboe

Jens,
I ran into something similar today. I'd like to use cdrecord to write to a CD
and then immediately turn around and read from it for verification purposes...

...Except that I only get 2048 bytes from a 'cat /dev/scd0' until I take the CD
out and put it back in.

Is there a known way for a userland application to make an ioctl to the cdrom
device in a 2.4/2.6 kernel to tell it the media changed without forcing a tray
open & close?

I intend to execute a program with this ioctl (if there is such a thing) after
the cdrecord and before the 'cat'.

Thanks,
 -Byron

--
Byron Stanoszek                         Ph: (330) 644-3059
Systems Programmer                      Fax: (330) 644-8110
Commercial Timesharing Inc.             Email: byron@comtime.com