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=-8.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 D6240C433B4 for ; Mon, 3 May 2021 08:10:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9C10961040 for ; Mon, 3 May 2021 08:10:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230186AbhECILI (ORCPT ); Mon, 3 May 2021 04:11:08 -0400 Received: from mx2.suse.de ([195.135.220.15]:54350 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229817AbhECILH (ORCPT ); Mon, 3 May 2021 04:11:07 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id C6390B157; Mon, 3 May 2021 08:10:13 +0000 (UTC) Date: Mon, 3 May 2021 10:10:12 +0200 From: Petr Vorel To: NeilBrown Cc: "J . Bruce Fields" , linux-nfs@vger.kernel.org, Steve Dickson , Chuck Lever , Alexey Kodanev Subject: Re: Re: [RFC PATCH 1/1] mount.nfs: Fix mounting on tmpfs Message-ID: Reply-To: Petr Vorel References: <20210422191803.31511-1-pvorel@suse.cz> <20210422202334.GB25415@fieldses.org> <20210423142329.GB10457@fieldses.org> <20210423181345.GE10457@fieldses.org> <162000848714.10466.9299093696289919822@noble.neil.brown.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <162000848714.10466.9299093696289919822@noble.neil.brown.name> Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org > On Sat, 24 Apr 2021, J . Bruce Fields wrote: > > On Fri, Apr 23, 2021 at 07:04:41PM +0200, Petr Vorel wrote: > > > Hi Bruce, > > > > On Fri, Apr 23, 2021 at 04:17:52AM +0200, Petr Vorel wrote: > > > > > Hi, > > > > > > On Thu, Apr 22, 2021 at 09:18:03PM +0200, Petr Vorel wrote: > > > > > > > LTP NFS tests (which use netns) fails on tmpfs since d4066486: > > > > > > > mount -t nfs -o proto=tcp,vers=4.2 10.0.0.2:/tmp/ltp.nfs01.nfs-4.2/LTP_nfs01.UF6gRZCy3O/4.2/tcp /tmp/ltp.nfs01.nfs-4.2/LTP_nfs01.UF6gRZCy3O/4.2/0 > > > > > > > mount.nfs: mounting 10.0.0.2:/tmp/ltp.nfs01.nfs-4.2/LTP_nfs01.UF6gRZCy3O/4.2/tcp failed, reason given by server: No such file or directory > > > > > > We should figure out the reason for the failure. A network trace might > > > > > > help. > > > > > Anything specific you're looking for? > > > > Actually I was thinking of capturing the network traffic, something > > > > like: > > > > tcpdump -s0 -wtmp.pcap -i > > > > then try the mount, then kill tcpdump and look at tmp.pcap. > > > I don't see anything suspicious, can you please have a look? > > > https://gitlab.com/pevik/tmp/-/raw/master/nfs.v3.pcap > > > https://gitlab.com/pevik/tmp/-/raw/master/nfs.v4.pcap > > > https://gitlab.com/pevik/tmp/-/raw/master/nfs.v4.1.pcap > > > https://gitlab.com/pevik/tmp/-/raw/master/nfs.v4.2.pcap > > It might be the "hide" option, that's odd: > Nup. I think "hide" is ignored for NFSv4 anyway. > Problem is that a subdirectory of a tmpfs filesystem is being exported. > That requires (for NFSv4), the top of the tmpfs filesystem to be > exported with NFSEXP_V4ROOT so that an NFSv4 client can navigate down to > it. > But when mountd creates that V4ROOT export, it doesn't provide the fsid. > So the kernel rejects the export request. > We need to fix mountd to set the fsid on all exports within a filesystem > for which it was specified, particularly the NFSEXP_V4ROOT ancestors. > I might see if I how easy that is later. Hi Neil, Thanks a lot for analysis. Right, mount.nfs is not to blame, but the server part (nfs-kernel-server). Kind regards, Petr > NeilBrown