From mboxrd@z Thu Jan 1 00:00:00 1970 From: Willem Riede Subject: Re: Badness in scsi_single_lun_run at /root/scsi/scsi_lib.c:344 Date: Wed, 28 Jan 2004 12:36:09 -0500 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <20040128173609.GE23308@serve.riede.org> References: <20040127003244.GM23308@serve.riede.org> <20040128033041.GY23308@serve.riede.org> <20040128084142.A4835@beaverton.ibm.com> Reply-To: wrlk@riede.org Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: Received: from rwcrmhc11.comcast.net ([204.127.198.35]:17853 "EHLO rwcrmhc11.comcast.net") by vger.kernel.org with ESMTP id S266022AbUA1RgM (ORCPT ); Wed, 28 Jan 2004 12:36:12 -0500 Content-Disposition: inline In-Reply-To: <20040128084142.A4835@beaverton.ibm.com> (from patmans@us.ibm.com on Wed, Jan 28, 2004 at 11:41:43 -0500) List-Id: linux-scsi@vger.kernel.org To: Patrick Mansfield Cc: linux-scsi@vger.kernel.org On 2004.01.28 11:41, Patrick Mansfield wrote: > On Tue, Jan 27, 2004 at 10:30:41PM -0500, Willem Riede wrote: > > On 2004.01.26 19:32, Willem Riede wrote: > > > Jan 26 17:13:23 fallguy kernel: Badness in scsi_single_lun_run at /root/scsi/scsi_lib.c:344 > > I was trying to figure out what happened, apparently I missed a check when > splitting the locks up and removing a lock hiearchy. > > We should only clear starget_sdev_user when the sdev has no more IO. We > want to run (a bunch of) IO for a given starget_sdev_user, and when there is > no more IO, clear starget_sdev_user so someone else has a chance to run. > > I'm trying to figure out a fix without adding any lock hiearchy. queue_lock > protects device_busy, but host_lock protects starget_sdev_user. Anything I can do to help (if only to test when you have an idea)? > The single lun devices and code are annoying :-( > > Do you know if the single lun code is for performance, or because of > hardware limitations - that is we don't want a disc change between IO, or > does the device just fail? In the case of the NEC PD/CD, it is a hardware limitation. You can only have one disc inserted at a time, either CD or PD. Mixing IO will fail for the absent media type. Regards, Willem Riede.