From owner-freebsd-current  Thu Jan  6 15: 8:57 2000
Delivered-To: freebsd-current@freebsd.org
Received: from alcanet.com.au (border.alcanet.com.au [203.62.196.10])
	by hub.freebsd.org (Postfix) with ESMTP id A308515797
	for <freebsd-current@FreeBSD.ORG>; Thu,  6 Jan 2000 15:08:52 -0800 (PST)
	(envelope-from jeremyp@gsmx07.alcatel.com.au)
Received: by border.alcanet.com.au id <40323>; Fri, 7 Jan 2000 10:01:19 +1100
Content-return: prohibited
From: Peter Jeremy <peter.jeremy@alcatel.com.au>
Subject: Re: ATA driver problems
In-reply-to: <20000106103851.A620@gsmx07.alcatel.com.au>; from
 peter.jeremy@alcatel.com.au on Thu, Jan 06, 2000 at 10:38:51AM +1100
To: freebsd-current@FreeBSD.ORG
Message-Id: <00Jan7.100119est.40323@border.alcanet.com.au>
MIME-version: 1.0
X-Mailer: Mutt 1.0i
Content-type: text/plain; charset=us-ascii
References: <20000106103851.A620@gsmx07.alcatel.com.au>
Date: Fri, 7 Jan 2000 10:01:19 +1100
Sender: owner-freebsd-current@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.ORG

On 2000-Jan-06 10:38:51 +1100, I wrote:
["dd if=/dev/rad0c of=/dev/null bs=64k" dies with an error]

I did some poking around and found that there are two bugs which
conspire together to cause this:
1) diskstrategy() does not detect dscheck() returning EOF, instead
   passing a zero-length request to the underlying driver.
2) The ata-disk driver doesn't check for (and ignore) zero-length
   requests, instead passing them onto the disk.

See kern/15956 for details and patches.

Peter


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message