From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [PATCH 1/3] libmultipath: replace PATH_TIMEOUT with PATH_DOWN Date: Mon, 06 Oct 2014 16:35:02 +0200 Message-ID: <5432A896.5040205@suse.de> References: <1412381483-15757-1-git-send-email-bmarzins@redhat.com> <1412381483-15757-2-git-send-email-bmarzins@redhat.com> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <1412381483-15757-2-git-send-email-bmarzins@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: Benjamin Marzinski , device-mapper development Cc: Christophe Varoqui List-Id: dm-devel.ids On 10/04/2014 02:11 AM, Benjamin Marzinski wrote: > The way the code works, PATH_TIMEOUT is treated mostly like PATH_UP or > PATH_GHOST by check_path. If the the path was previously failed, it will > even reinstate the path. It will also trigger prio refreshing. It seems > that PATH_TIMEOUT should be at least as serious as PATH_PENDING, but the > way the code works, it's not. In pathinfo, PATH_TIMEOUT gets changed > directly to PATH_DOWN, which makes sense. But assuming that's the correct > thing to do, why have PATH_TIMEOUT at all? > = Because a timeout is different from a normal path down. Timeout means the tur checker is stuck somehow. And we currently have no real means of resetting it (aio_cancel doesn't really abort the I/O, is just short-circuit the callback). So the intention of this patch was that we want to get notified if a TUR timeout occurs, as this might lead to other subsequent errors. > The only thing that it does that seems helpful is that when you print out > the path, instead of it saying that the path is down, it says that the > path has timed out. But if we are going to treat is like the path is > down, then I don't see this being too helpful. And the way we are treati= ng > PATH_TIMEOUT right now is definitely not right. > = See above. I really would like to be notified for PATH_TIMEOUT scenarios ... 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)