[Linux-cluster] GFS nolock mount on top of existing GFS2 shared mount -- won't umount

[rhurst at bidmc.harvard.edu]

I have a new RHEL 5.5 cluster running and created a new GFS2 filesystem to rsync the old filesystem over (leaving the original intact in case we had to do a fail-back for whatever reason).

I made a pilot error by pasting the GFS local mount command on the wrong ssh session window, resulting in:

/dev/mapper/VGCCC-lvolshare55
              gfs2    6.5G   34M  6.5G   1% /cluster/share
/dev/mapper/VGCCC-lvolshare47
               gfs    6.5G   34M  6.5G   1% /cluster/share

No worries, I'll just umount it and do the mount on the correct sesssion.  ACK!!  The umount fails:

$ umount /cluster/share
/sbin/umount.gfs: /cluster/share is not a gfs filesystem
/sbin/umount.gfs2: /cluster/share is not a gfs2 filesystem
/sbin/umount.gfs: /cluster/share is not a gfs filesystem

>From /proc/mounts:

/dev/mapper/VGCCC-lvolshare55 /cluster/share gfs2 rw,noatime,hostdata=jid=1:id=131078:first=0 0 0

/dev/mapper/VGCCC-lvolshare47 /cluster/share gfs rw,noatime,nodiratime,lockproto=lock_nolock,localflocks,localcaching,oopses_ok 0 0

Is this a "bug" or is there another way to force this umount?

$ cat /etc/redhat-release 
Red Hat Enterprise Linux Server release 5.5 (Tikanga)

$ modinfo gfs
filename:       /lib/modules/2.6.18-194.8.1.el5/weak-updates/gfs/gfs.ko
license:        GPL
author:         Red Hat, Inc.
description:    Global File System 0.1.34-12.el5
srcversion:     5A1F914F64A3562AB4025B8
depends:        dlm
vermagic:       2.6.18-192.el5 SMP mod_unload gcc-4.1

$ modinfo gfs2
filename:       /lib/modules/2.6.18-194.8.1.el5/kernel/fs/gfs2/gfs2.ko
license:        GPL
author:         Red Hat, Inc.
description:    Global File System
srcversion:     A97C797F6991C7EDA8194EE
depends:        
vermagic:       2.6.18-194.8.1.el5 SMP mod_unload gcc-4.1
module_sig:	883f3504c222156a4a68dd25a16b2151126d9309f5e3c80d84761a7477f627d2db44f2d3cc92efa8009f6228ef166da627f961ae8a05a7f686a32e4c712