From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0F4EAC4360F for ; Sun, 31 Mar 2019 09:05:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DA7172146F for ; Sun, 31 Mar 2019 09:05:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726979AbfCaJFf (ORCPT ); Sun, 31 Mar 2019 05:05:35 -0400 Received: from trent.utfs.org ([94.185.90.103]:50074 "EHLO trent.utfs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726710AbfCaJFc (ORCPT ); Sun, 31 Mar 2019 05:05:32 -0400 Received: from localhost (localhost [IPv6:::1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by trent.utfs.org (Postfix) with ESMTPS id 5531D5FB40; Sun, 31 Mar 2019 11:05:28 +0200 (CEST) Date: Sun, 31 Mar 2019 02:05:28 -0700 (PDT) From: Christian Kujau To: David Howells cc: linux-kernel@vger.kernel.org, Anna Schumaker , Steve Dickson Subject: Re: FS-Cache: Duplicate cookie detected In-Reply-To: <8939.1552374108@warthog.procyon.org.uk> Message-ID: References: <22096.1551878195@warthog.procyon.org.uk> <10106.1551892803@warthog.procyon.org.uk> <17155.1552056554@warthog.procyon.org.uk> <2827.1552315718@warthog.procyon.org.uk> <8939.1552374108@warthog.procyon.org.uk> User-Agent: Alpine 2.21.999 (DEB 277 2018-05-20) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi David, On Tue, 12 Mar 2019, David Howells wrote: > > My /usr/local/src mount was mounted with vers=4.2 (default), while > > nfstest_cache was mounting its test-mount with vers=4.1! Apart from the > > different rsize/wsize values, the version number stood out. And indeed, > > when I mount my regular NFS mount /usr/local/src with vers=4.1, the > > "duplicate cookie" is no longer printed. > > Yeah - NFS superblocks are differentiated by a whole host of parameters, > including protocol version number, and caches aren't shared between > superblocks because this introduces a tricky coherency problem. > > The issue is that NFS superblocks to the same place do not currently manage > coherency (inode attributes, data) between themselves, except via the server. > > However, if "fsc" isn't given on the mount commandline, the superblock > probably shouldn't get a server-level cookie if we can avoid it. Just checking - are you waiting for new results from me, should I test something that I missed? Or are new patches in the works? :-D Thanks, Christian. -- BOFH excuse #139: UBNC (user brain not connected)