From: Trond Myklebust Subject: Re: [PATCH 2/2] Enable v4 mounts when either "nfsvers=4" or "vers=4" option are set (vers-02) Date: Tue, 25 Aug 2009 16:49:05 -0400 Message-ID: <1251233345.25372.67.camel@heimdal.trondhjem.org> References: <4A9424DB.2040303@RedHat.com> <4A942593.8030101@RedHat.com> <4A943914.9020104@RedHat.com> <7AB7BC01-F9E5-4611-BB4B-2B6E27069631@oracle.com> <4A944645.1020003@RedHat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: Linux NFS Mailing list , Linux NFSv4 mailing list To: Steve Dickson Return-path: In-Reply-To: <4A944645.1020003@RedHat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nfsv4-bounces@linux-nfs.org Errors-To: nfsv4-bounces@linux-nfs.org List-ID: On Tue, 2009-08-25 at 16:15 -0400, Steve Dickson wrote: > > On 08/25/2009 03:32 PM, Chuck Lever wrote: > > On Aug 25, 2009, at 3:18 PM, Steve Dickson wrote: > >> On 08/25/2009 02:59 PM, Chuck Lever wrote: > >>> On Aug 25, 2009, at 1:55 PM, Steve Dickson wrote: > >>>> commit 1471d23d692efc7388794a8a3c3b9e548d1c5be8 > >>>> Author: Steve Dickson > >>>> Date: Tue Aug 25 12:15:18 2009 -0400 > >>>> > >>>> Make sure umount use correct fs type. > >>>> > >>>> umounts use the fs type in /etc/mtab to determine > >>>> which file system is being unmounted. The mtab > >>>> entry is create during the mount. To ensure the > >>>> correct entry is create when the fs type changes > >>>> due to the mount options, the address of the fs_type > >>>> variable has to be passed so it can be updated. > >>> > >>> In general, my policy is to record the user requested mount options in > >>> /etc/mtab, and let umount.nfs handle renegotiating as needed. For > >>> version/transport this means that the server's configuration can change > >>> between the mount and the umount, and the umount will still work. > >>> > >>> Perhaps this is not a consideration for NFSv4, but leaving the mount > >>> options as specified by the user would save the need to update the fs > >>> type, and would be a consistent policy for v2, v3, and v4. I think it > >>> would be cleaner to teach umount.nfs to do the right thing with "-t nfs > >>> -o v4" rather than rewriting the options in /etc/mtab. > >> Since nfs4 is truly a separate/different file system from nfs in the > >> kernel, I think we should continue making that distinction in system > >> files like mtab and /proc/mounts.... > > > > We are teaching mount.nfs not to care about nfs/nfs4 (at least > > externally). Why should umount.nfs? > That's not quite accurate... IMHO.. I see it as we are teach mount.nfs to > accept new command line arguments that will cause a nfs4 file system > to be mounted... and that is done by caring which fs type mount is > dealing with... So, why couldn't we just do this in the kernel? It should be easily doable to set nfs -overs=4 to mount an NFSv4 filesystem. We only have to do this for text mounts... Cheers Trond