From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [PATCH 2/2] ib_srp: 64bit LUN fixes Date: Fri, 04 Jul 2014 16:12:57 +0200 Message-ID: <53B6B669.10704@suse.de> References: <1404474875-109997-1-git-send-email-hare@suse.de> <1404474875-109997-3-git-send-email-hare@suse.de> <53B69E97.4050901@acm.org> <53B6A5B4.2040807@suse.de> <20140704134835.GB12345@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]:56108 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752802AbaGDOM6 (ORCPT ); Fri, 4 Jul 2014 10:12:58 -0400 In-Reply-To: <20140704134835.GB12345@infradead.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Christoph Hellwig Cc: Bart Van Assche , James Bottomley , linux-scsi@vger.kernel.org On 07/04/2014 03:48 PM, Christoph Hellwig wrote: > On Fri, Jul 04, 2014 at 03:01:40PM +0200, Hannes Reinecke wrote: >> What I would like to do is to provide accessor functions for the scs= i lun; >> I've started this already for the older SCSI parallel drivers (see m= y >> earlier patch). >> Once everything is moved over to accessors it should be trivial to m= ove from >> the current scsilun_to_int representation in struct scsi_device to t= he >> 'real' LUN. >> >> Adding another field would be bit of an overkill IMO, seeing that we= can >> achieve the very same thing with a bit of code reshuffling. >> >> James, Christoph, what's your opinion on using accessors? >> Would solve this issue nicely, and we can also use proper functions = for HBAs >> only capable of handling 32bit LUNs. >> Drawback is that we would need accessors also for this capable of ha= ndling >> full 64bit LUNs, thus potentially incur some overhead there. > > I think storing the struct scsi_lun in the scsi_device is the right w= ay > to go ahead. Any "accessors" for 8 or 32-bit LUNs should be simply > enough by just ignoring bits in the array, so there's very little > performance overhead. > > If we can get rid of the old scalar LUN field that would be great, > and given that we know the printk format fallout already it doesn't l= ook > like too much work. Do you want to look into this? > Already working on it. 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