From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [PATCH 8/8] dm-mpath: do not activate failed paths Date: Fri, 28 Feb 2014 15:44:23 +0100 Message-ID: <5310A0C7.6000601@suse.de> References: <1393486229-72034-1-git-send-email-hare@suse.de> <1393486229-72034-9-git-send-email-hare@suse.de> <11AF7C027C4C02408624617A49860784010D7C45@BPXM12GP.gisp.nec.co.jp> <531057A7.4020208@suse.de> <11AF7C027C4C02408624617A49860784010D7F79@BPXM12GP.gisp.nec.co.jp> <53105C4D.50305@suse.de> <20140228142230.GA1140@redhat.com> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <20140228142230.GA1140@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Mike Snitzer Cc: Junichi Nomura , "dm-devel@redhat.com" , Alasdair Kergon List-Id: dm-devel.ids On 02/28/2014 03:22 PM, Mike Snitzer wrote: [ .. ] > = > FYI, I still intend to review/take your "accept failed paths" patch. > Would be helpful if any rebase is needed for that patch that you do so > and re-post. > = > One thing I noticed is you're only converting MAJ:MIN paths to devices. > I think we should factor a helper out of DM core that does the full path > lookup check from dm_get_device() -- rather than you open coding an > older version of the MAJ:MIN device path processing. > = > But is there a reason for not using lookup_bdev()? Because the device > is failed it cannot be found using lookup_bdev()? > = Yes, that's precisely it. When setting dev_loss_tmo very aggressively (to, say, 10 or even 5 seconds) it might well be that multipathd won't be able to keep up with the events in time. So by the time multipathd tries to push a new table into the kernel (which contains major:minor numbers only) those devices are already gone. So lookup_bdev() won't be able to find them, either. Not sure if factoring things out from dm_get_device() would help here ... But I'll be sending an updated patch, which'll apply on top of the 'push back' patchset. Cheers, Hannes -- = 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)