From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: Bugs in multipath scsi in 4.3-rc2 Date: Sun, 4 Oct 2015 09:45:56 +0200 Message-ID: <20151004074556.GA13932@lst.de> References: <20150925121636.GC12540@fergus.ozlabs.ibm.com> <20150925151802.GB20282@lst.de> <1443202278.2188.13.camel@HansenPartnership.com> <20150930151449.GC26299@lst.de> <20150930215303.GI2627@mtj.duckdns.org> <1443652494.2185.57.camel@HansenPartnership.com> <20151002125608.GB14899@lst.de> <1443792301.2209.4.camel@HansenPartnership.com> <20151002133423.GA15867@lst.de> <1443793497.2209.10.camel@HansenPartnership.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from verein.lst.de ([213.95.11.211]:49802 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751225AbbJDHp7 (ORCPT ); Sun, 4 Oct 2015 03:45:59 -0400 Content-Disposition: inline In-Reply-To: <1443793497.2209.10.camel@HansenPartnership.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: James Bottomley Cc: Christoph Hellwig , Tejun Heo , Paul Mackerras , linux-scsi@vger.kernel.org On Fri, Oct 02, 2015 at 06:44:57AM -0700, James Bottomley wrote: > I think I prefer restoring that to having to build in every dh module to > get them to work. If we take your proposed fix for the sync module load > in the current scheme, any non-built in modules would never attach, so > we'd be moving towards the conclusion that *every* device handler has to > be non-modular. You don't need to build every module in to make it work. In 4.2 and earlier we already only auto load modules when dm-multipath explicitly attaches to them. That will still work in 4.3+. In fact we will now autoload when activating through sysfs as well. With the change I sent to Paul we still won't autoload at scan time, which would be really useful to have, but wasn't implemented previously. > Skimming the code it looks like dh should be using the driver binding > model rather than reinventing it. That would decouple it better and > make sure binding happened regardless of when the module was loaded. I tried this early on but gave up because I ran into too many problems. I can try to give it a spin again.