From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alasdair G Kergon Subject: Re: [dm-devel] [RESEND PATCH 2/3] dm mpath: add 'default_hw_handler' feature Date: Wed, 11 Jul 2012 11:27:54 +0100 Message-ID: <20120711102754.GA2095@agk-dp.fab.redhat.com> References: <1340735525-21083-1-git-send-email-snitzer@redhat.com> <1340735525-21083-3-git-send-email-snitzer@redhat.com> <4FEAA557.7050501@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mx1.redhat.com ([209.132.183.28]:42971 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751764Ab2GKK2E (ORCPT ); Wed, 11 Jul 2012 06:28:04 -0400 Content-Disposition: inline In-Reply-To: <4FEAA557.7050501@suse.de> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Hannes Reinecke , device-mapper development , James Bottomley , Mike Snitzer , linux-scsi@vger.kernel.org On Wed, Jun 27, 2012 at 08:16:55AM +0200, Hannes Reinecke wrote: > On 06/26/2012 08:32 PM, Mike Snitzer wrote: > > When specifying the feature 'default_hw_handler' multipath will use > > the currently attached hardware handler instead of trying to attach the > > one specified during table load. If no hardware handler is attached the > > specified hardware handler will be used. > > > > Leverages scsi_dh_attach's ability to increment the scsi_dh's reference > > count if the same scsi_dh name is provided when attaching -- currently > > attached scsi_dh name is determined with scsi_dh_attached_handler_name. > > > > Signed-off-by: Mike Snitzer > > Tested-by: Babu Moger > > Reviewed-by: Chandra Seetharaman > Looks good. Maybe, but I'd like to see an inline explanation of what this confusing new setting means and a better patch header that provides some motivation for this change. To my eyes, the word "default" is over-used here. If I *don't* specify the new "default" flag, surely I'll get default behaviour, won't I, by definition? And if I do specify it, I'm asking for default behaviour too, so isn't it redundant? Alasdair