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Date: Tue, 18 Feb 1997 19:51:17 +1100
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199702180851.TAA02058@godzilla.zeta.org.au>
To: kuku@gilberto.physik.rwth-aachen.de, thorpej@nas.nasa.gov
Subject: Re: ccd and bounce buffers
Cc: freebsd-hackers@freefall.freebsd.org
Sender: owner-hackers@FreeBSD.ORG
X-Loop: FreeBSD.org
Precedence: bulk

>So, maybe I'm missing how things work in the FreeBSD world, but what
>on earth does bounce buffers have to do with the ccd?  The ccd is
>a layered driver, which knows nothing about the underlying component
>(or, at least, that's how it's _supposed_ to work, and is how it works
>in NetBSD).

It didn't initialize cbp->cb_buf.b_bufsize, and the bounce buffer code
depends on this being initialized since b_bcount might be modified by
drivers.

Buffers have a lot of hair, especially in FreeBSD, and it's not clear
that anywhere outside of vfs_bio.c can know how how to initialize them
Perhaps cb_buf should be copied from *bp and then modified.

Bruce