Subject: Re: cd-rw
To: Chris G. Demetriou <cgd@netbsd.org>
From: Thor Lancelot Simon <tls@rek.tjls.com>
List: port-alpha
Date: 02/16/2000 09:14:35
On Tue, Feb 15, 2000 at 10:05:10PM -0800, Chris G. Demetriou wrote:
> "Kevin P. Neal" <kpneal@pobox.com> writes:
> > Works just fine. Only odd thing is that if I dd a CD in the burner to
> > a file, the drive fails to stop reading at the end of the CD, returning
> > garbage or whatever to the dd process which will never stop. 
> > 
> > I can dd just fine in my RRD43, so it's not so much a big deal. 
> 
> raw device, or block device?
> 
> I think i _might_ have seen that on a block device recently (on i386),
> but i don't recall all the details and didn't have time to track it
> down at the time...

I think this is another flavor of the same old bug we've had for ~ever
with 'dd' from raw SCSI devices: when you hit the end of the device,
instead of EOF and a short read -- as you'd expect, and so 'dd' or 'cat'
would actually work right! -- a SCSI command is issued to read past the
end, you get an error back, and the user program splodes.

Thor