Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx1.redhat.com ([209.132.183.28]:41519 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756652AbaAITNC (ORCPT ); Thu, 9 Jan 2014 14:13:02 -0500 Date: Thu, 9 Jan 2014 14:12:59 -0500 From: Jeff Layton To: Trond Myklebust Cc: "Yin.JianHong" , Linux NFS Mailing List Subject: Re: [PATCH RFC] nfs: remove nfs_show_devname Message-ID: <20140109141259.553c58f0@tlielax.poochiereds.net> In-Reply-To: <6FE57B0D-2373-4B40-BA14-E6F2BF3C44E3@primarydata.com> References: <1389293995-634-1-git-send-email-jlayton@redhat.com> <6FE57B0D-2373-4B40-BA14-E6F2BF3C44E3@primarydata.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-nfs-owner@vger.kernel.org List-ID: On Thu, 9 Jan 2014 14:06:54 -0500 Trond Myklebust wrote: > > On Jan 9, 2014, at 13:59, Jeff Layton wrote: > > > The nfs code will currently construct a devname to show in places like > > /proc/mounts by turning a dentry into a path. Unfortunately, that's > > somewhat problematic if the user ended up mounting through a symlink on > > the server. The devname that then shows up in /proc/mounts now doesn't > > match the one that was originally passed into the mount request. > > This is 100% according to design. Why is it suddenly a problem? > > By displaying the original pathname, you also end up bypassing referral resolution, etc. This is exactly why the .show_devname operation was introduced in the first place. > AFAIU, the main issue is that when /etc/mtab is a symlink to /proc/mounts, you can't do this in the example in the patch description: # mount server:/export/bar /mnt/bar # umount server:/export/bar ...since umount will try to ID the mountpoint by looking up the devname in /etc/mtab. What exactly would this break with referrals? -- Jeff Layton