Return-Path: Received: from fieldses.org ([173.255.197.46]:33454 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934826AbcCPPFN (ORCPT ); Wed, 16 Mar 2016 11:05:13 -0400 Date: Wed, 16 Mar 2016 11:05:10 -0400 From: "J. Bruce Fields" To: William Dauchy Cc: NeilBrown , Linux NFS mailing list Subject: Re: [PATCH] sunrpc/cache: drop reference when sunrpc_cache_pipe_upcall() detects a race Message-ID: <20160316150510.GE11520@fieldses.org> References: <87y49ylq76.fsf@notabene.neil.brown.name> <20160314203846.GA22276@fieldses.org> <20160315131959.GA419@fieldses.org> <87vb4nh406.fsf@notabene.neil.brown.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-nfs-owner@vger.kernel.org List-ID: On Wed, Mar 16, 2016 at 08:31:03AM +0100, William Dauchy wrote: > Hi Bruce, > > Thank you for your reply. > > On Tue, Mar 15, 2016 at 9:37 PM, NeilBrown wrote: > > I agree that it isn't needed for stable - the race is tiny and the > > consequence of losing the race is that entries get stuck in the cache > > and possible an exported filesystem cannot be unmounted. > > I believe in an industrial usage, this race will become more common; Why is that? > moreover the consequence of an exported filesystem which can't be > unmounted is not something I can accept in some environment. > > I accept your judgment about including it or not in -stable but I am > just complaining about the lack of further consideration for those > type of fixes in nfs generally speaking. In an industrial usage, we > are hitting races way more easily than in a normal usage; lost of them > are already fixed and we do backports ourself. Do you have a list? > We are at a point where > it becomes almost impossible to come with a proof and say "we are > hitting this race, and this patch fixes the issue, please backport in > -stable". I don't expect *proof*, necessarily, but some sort of argument would be helpful. --b.