From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757142Ab0KKWhB (ORCPT ); Thu, 11 Nov 2010 17:37:01 -0500 Received: from e5.ny.us.ibm.com ([32.97.182.145]:49337 "EHLO e5.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754524Ab0KKWg7 (ORCPT ); Thu, 11 Nov 2010 17:36:59 -0500 Date: Thu, 11 Nov 2010 14:36:50 -0800 From: Mike Anderson To: James Bottomley Cc: "Nicholas A. Bellinger" , linux-scsi , linux-kernel , Jeff Garzik , Christoph Hellwig Subject: Re: [PATCH] scsi: Convert scsi_host->cmd_serial_number to odd numbered atomic_t counter Message-ID: <20101111223650.GA10257@linux.vnet.ibm.com> References: <1289472405-31003-1-git-send-email-nab@linux-iscsi.org> <1289490783.2982.33.camel@mulgrave.site> <1289511475.2867.138.camel@haakon2.linux-iscsi.org> <1289512549.2982.44.camel@mulgrave.site> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1289512549.2982.44.camel@mulgrave.site> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org James Bottomley wrote: > On Thu, 2010-11-11 at 13:37 -0800, Nicholas A. Bellinger wrote: > > > > ..snip.. > > > > Sounds good to me, but you will recall the last attempt to make > > scsi_cmd_get_serial() optional for the special case LLDs, that we > > started running quickly in the legacy usage of cmd->serial_number in > > scsi_softirq_done() and the side effects in scsi_try_to_abort_cmd(), who > > use is complex enough that we have not found a proper resolution > > sufficent to andmike discussed here: > > Yes, that's what I meant by "eliminate the overloading of the serial > number zero value" above. This needs fixing before the serial number > can be dumped for fast hba drivers. > In the last email referenced below I believed that since scsi_softirq_done is calling scsi_eh_scmd_add without the SCSI_EH_CANCEL_CMD flag set this will stop scsi_try_to_abort_cmd from being called. Since scsi_softirq_done is the one setting serial_number to 0 I do not believe we can hit the serial number == 0 check in scsi_try_to_abort_cmd anymore. > > http://marc.info/?l=linux-scsi&m=128820726325009&w=2 -andmike -- Michael Anderson andmike@linux.vnet.ibm.com