Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx1.redhat.com ([209.132.183.28]:17264 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756593Ab2DMXAj (ORCPT ); Fri, 13 Apr 2012 19:00:39 -0400 Date: Fri, 13 Apr 2012 19:00:24 -0400 From: Jeff Layton To: Peter Staubach Cc: Steve Dickson , Malahal Naineni , "linux-nfs@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "miklos@szeredi.hu" , "viro@ZenIV.linux.org.uk" , "hch@infradead.org" , "michael.brantley@deshaw.com" Subject: Re: [PATCH RFC] vfs: make fstatat retry on ESTALE errors from getattr call Message-ID: <20120413190024.5095f9b1@tlielax.poochiereds.net> In-Reply-To: <2F609A9B-B44B-4CEA-BF35-D6BEDA729363@exagrid.com> References: <1334316311-22331-1-git-send-email-jlayton@redhat.com> <20120413150518.GA1987@us.ibm.com> <20120413114236.0e557e01@tlielax.poochiereds.net> <4F884F32.7010402@RedHat.com> <2F609A9B-B44B-4CEA-BF35-D6BEDA729363@exagrid.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-nfs-owner@vger.kernel.org List-ID: On Fri, 13 Apr 2012 13:34:51 -0400 Peter Staubach wrote: > I still think that returning ESTALE to the application is just exposing a short coming in the implementation. From a path based system like stat(), the application should see either ENOENT or some sort valid return. > Agreed, but I'm willing to live with a solution that addresses most of these situations, even if we can't fix them all. If retrying indefinitely may be a problem for other filesystems then we can't just ignore that... > I also look at the looping from the other side. While possible, of course, I'd like to see someone construct a situation where it really happens. By this, I don't mean a thought experiment, but a real running situation. > > We already have evidence, in the form of the Solaris NFS client, that infinite looping does not happen in nature. > I'm fairly certainly that looping indefinitely would be just fine for NFS. My main concern is those FUSE fs' that Miklos alluded to when he reviewed your earlier set. He said that some can return ESTALE indefinitely, and they don't necessarily respect signals. If limiting the number of retries helps prevent problems with those, then that's still better than the current situation. -- Jeff Layton