From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [RFC] training mpath to discern between SCSI errors Date: Mon, 30 Aug 2010 14:39:12 +0200 Message-ID: <4C7BA670.2060303@suse.de> References: <20100825155918.GB8509@redhat.com> <4C7B984E.4070802@suse.de> <4C7B9F14.9080900@mvista.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Mike Snitzer , Kiyoshi Ueda , Tejun Heo , michaelc@cs.wisc.edu, James.Bottomley@suse.de, tytso@mit.edu, linux-scsi@vger.kernel.org, jaxboe@fusionio.com, jack@suse.cz, linux-kernel@vger.kernel.org, swhiteho@redhat.com, linux-raid@vger.kernel.org, linux-ide@vger.kernel.org, konishi.ryusuke@lab.ntt.co.jp, linux-fsdevel@vger.kernel.org, vst@vlnb.net, rwheeler@redhat.com, Christoph Hellwig , chris.mason@oracle.com, dm-devel@redhat.com To: Sergei Shtylyov Return-path: In-Reply-To: <4C7B9F14.9080900@mvista.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Sergei Shtylyov wrote: > Hello. >=20 > Hannes Reinecke wrote: >=20 >> Actually, I think we have two separate issues here: >> 1) The need of having more detailed I/O errors even in the fs layer.= This >> we've already discussed at the LSF, consensus here is to allow ot= her >> errors than just 'EIO'. >> Instead of Mike's approach I would rather use existing error code= s >> here; >> this will make the transition somewhat easier. >> Initially I would propose to return 'ENOLINK' for a transport fai= lure, >> 'EIO' for a non-retryable failure on the target, and 'ENODEV' for= a >> retryable failure on the target. >=20 > Are you sure it's not vice versa: EIO for retryable and ENODEV for > non-retryable failures. ENODEV looks more like permanent condition to= me. >=20 Ok, can do. And looking a the error numbers again, maybe we should be using 'EREMOT= EIO' for non-retryable failures. So we would be ending with: ENOLINK: transport failure EIO: retryable remote failure EREMOTEIO: non-retryable remote failure Does that look okay? 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: Markus Rex, HRB 16746 (AG N=FCrnberg)