From owner-freebsd-current@FreeBSD.ORG  Sun Dec 22 17:55:34 2013
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Delivered-To: freebsd-current@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115])
 (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits))
 (No client certificate requested)
 by hub.freebsd.org (Postfix) with ESMTPS id BA1AA525;
 Sun, 22 Dec 2013 17:55:34 +0000 (UTC)
Received: from pozo.com (pozo.com [50.197.129.137])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (No client certificate requested)
 by mx1.freebsd.org (Postfix) with ESMTPS id 9AC851DE7;
 Sun, 22 Dec 2013 17:55:34 +0000 (UTC)
Received: from T61p.pozo.com (t61p.pozo.com [192.168.0.4])
 (authenticated bits=0)
 by pozo.com (8.14.7/8.14.7) with ESMTP id rBMHssMv004688
 (version=TLSv1/SSLv3 cipher=DHE-DSS-AES256-SHA bits=256 verify=NOT);
 Sun, 22 Dec 2013 09:54:54 -0800 (PST) (envelope-from null@pozo.com)
Message-Id: <201312221754.rBMHssMv004688@pozo.com>
X-Mailer: QUALCOMM Windows Eudora Version 7.1.0.9
Date: Sun, 22 Dec 2013 09:54:49 -0800
To: freebsd-current@freebsd.org
From: Manfred Antar <null@pozo.com>
Subject: vfs_bio.c revision 259200 breaks writing to tape drive on
  current
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
X-Spam-Status: No, score=-2.4 required=5.0 tests=ALL_TRUSTED,BAYES_00,
 MISSING_MID,URIBL_BLOCKED autolearn=no version=3.3.2, No
X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on pozo.com
X-pozocom-MailScanner-Information: Please contact the ISP for more information
X-pozocom-MailScanner-ID: rBMHssMv004688
X-pozocom-MailScanner: Found to be clean
X-pozocom-MailScanner-From: null@pozo.com
Cc: kib@freebsd.org
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.17
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
 <freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-current>, 
 <mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current/>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
 <mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sun, 22 Dec 2013 17:55:34 -0000

The change to vfs_bio.c in revision 259200 breaks writing to scsi tape drive on i386 and sparc64 on current.
I don't have any other machines to test on.
here is example:

r259199:
(/)4794}mt rew
(/)4795}tar cvf /dev/sa0 kernel
a kernel

r259200:
(/)4781}mt rew
(/)4782}tar cvf /dev/sa0 kernel
a kerneltar: Write error

the changes between the two revisions:
line 3682 removed:

bp->b_resid = bip->bio_resid;   /* XXX: remove */

I noticed this when trying to do a dump and getting end of tape error.
tried different tape drives , different cables no change.
backed out r259200 to 259199 and everything works as before.
Manfred

========================
||      null@pozo.com           ||
||                                      ||
========================