5.1-BETA umount problems

[David Schultz]

On Mon, May 19, 2003, Andre Guibert de Bruet wrote:
> 
> On Sun, 18 May 2003, David Schultz wrote:
> 
> > On Mon, May 19, 2003, Makoto Matsushita wrote:
> > >
> > > truckman> IMHO, "umount -f /lib" should have failed in this case.
> > >
> > > I don't think so.  -f means 'force', so it should be successed even if
> > > this cause something trouble to running system.  If it would be
> > > unacceptable, there's easy way to solve it: don't use -f anymore, or
> > > add a new umount(8) option to do that.
> >
> > umount -f can be extremely useful on a multiuser system when you
> > *really* want to unmount a filesystem regardless of who might be
> > trying to use it.  However, it also makes it easy to shoot
> > yourself in the foot.  If it only fails in situations where you
> > are absolutely guaranteed to shoot yourself in the foot, that's
> > fine.  There's no reason it should allow someone to unmount a
> > filesystem that contains a mountpoint for another mounted
> > filesystem.
> >
> > By the way, why is the original poster walking around and shooting
> > himself in the foot?  Sigh.  The dangers of firearms...
> 
> I wanted to unmount as many filesystems as possible before connecting my
> Dazzle 6-in-1 USB reader (the one that used to work, but now causes
> panics). As you can imagine fsck'ing 650GB takes a little while... ;)
> Also, /lib on this system is nfs exported, and I couldn't be arsed to kill
> -9 nfsd and mountd.

If you want to be able to unmount /foo/bar before unmounting /foo,
mount /foo/bar as /foo_bar instead, and create a symlink.