From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [PATCH 1/2] Use sdev_scsi2lun for SCSI parallel drivers Date: Mon, 07 Jul 2014 09:54:51 +0200 Message-ID: <53BA524B.7060400@suse.de> References: <1404474875-109997-1-git-send-email-hare@suse.de> <1404474875-109997-2-git-send-email-hare@suse.de> <20140704134437.GA12345@infradead.org> <53B6B646.5080301@suse.de> <20140705094147.GA18130@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from cantor2.suse.de ([195.135.220.15]:54454 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751393AbaGGHyx (ORCPT ); Mon, 7 Jul 2014 03:54:53 -0400 In-Reply-To: <20140705094147.GA18130@infradead.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Christoph Hellwig Cc: James Bottomley , linux-scsi@vger.kernel.org On 07/05/2014 11:41 AM, Christoph Hellwig wrote: > On Fri, Jul 04, 2014 at 04:12:22PM +0200, Hannes Reinecke wrote: >>> So what would be set in the upper 48 bits for those drivers? We re= ceive >>> the LUN over the wire to start with. >>> >> None. All these devices are physically incapable of receiving or sen= ding >> LUNs more that a byte wide. > > So what problems does this patch fix then? > The intention is twofold: 1) Isolate from any fallout due to the 64bit LUN changes. By=20 introducing accessors we are guaranteed that the drivers will only=20 ever see LUN numbers they are expecting. 2) Using accessors allows us to eventually change the ->lun field to=20 'struct scsi_lun', and call 'scsilun_to_int' only for display=20 purposes. This will address the objection by Bart for ib_srp, but applies to other drivers as well. Cheers, Hannes --=20 Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=FCrnberg GF: J. Hawn, J. Guild, F. Imend=F6rffer, HRB 16746 (AG N=FCrnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html