From: Chuck Lever Subject: Re: redundant reverse DNS on NFS mount or umount Date: Mon, 2 Mar 2009 12:44:17 -0500 Message-ID: References: <499AD63B.20806@draigBrady.com> <20090302174155.GF967@fieldses.org> Mime-Version: 1.0 (Apple Message framework v930.3) Content-Type: text/plain; charset=ISO-8859-1; format=flowed delsp=yes Cc: =?ISO-8859-1?Q?P=E1draig_Brady?= , linux-nfs@vger.kernel.org To: "J. Bruce Fields" Return-path: Received: from acsinet11.oracle.com ([141.146.126.233]:35052 "EHLO acsinet11.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753166AbZCBRoi convert rfc822-to-8bit (ORCPT ); Mon, 2 Mar 2009 12:44:38 -0500 In-Reply-To: <20090302174155.GF967@fieldses.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Mar 2, 2009, at Mar 2, 2009, 12:41 PM, J. Bruce Fields wrote: > On Tue, Feb 17, 2009 at 03:22:35PM +0000, P=E1draig Brady wrote: >> I've a problem where reverse DNS is being done by the NFS server. >> This is very problematic when the DNS server goes away. >> As far as I can see there should be no lookups being performed >> because I've nothing in /etc/hosts.{allow,deny} and just >> numeric hosts in /etc/exports. >> >> I can simulate this easily by putting a bad nameserver in /etc/=20 >> resolv.conf >> and restarting the nfs server. Any mounts will take then take ages. >> Others seem to have had this issue as well, but possibly with >> non numeric names in /etc/exports: >> http://marc.info/?l=3Dlinux-nfs&m=3D110977757630297&w=3D2 >> http://marc.info/?l=3Dlinux-nfs&m=3D111015343008456&w=3D2 >> >> Here are my config details: >> >> # rpm -q nfs-utils >> nfs-utils-1.1.0-6.fc8 >> >> # cat /etc/resolv.conf >> search company.com >> nameserver 192.168.2.110 >> >> # cat /etc/exports >> /home 192.168.2.25(async,rw,all_squash,anonuid=3D500,anongid=3D500= ) >> >> Any ideas appreciated. > > I agree that DNS lookups shouldn't be required in this case. > > It's rpc.mountd that's responsible for this, so if you can figure out > where in the mountd code this is happening, it shouldn't be hard to =20 > fix. That would most likely be matchhostname(). -- Chuck Lever chuck[dot]lever[at]oracle[dot]com