Bug#222386: busybox-cvs: umount does not accept the -n option
On Fri, 2003-11-28 at 18:47, Erik Andersen wrote:
> On Fri Nov 28, 2003 at 05:40:14PM +0100, Paul Wagland wrote:
> > Thanks for the quick reply!
> >
> > On Fri, 2003-11-28 at 16:37, Erik Andersen wrote:
> > > On Fri Nov 28, 2003 at 02:42:15PM +0100, Paul Wagland wrote:
> > > > Package: busybox-cvs
> > > > Version: 20030926-2.1
> > > > Severity: important
> > > >
> > > > http://www.busybox.net/downloads/BusyBox.html specifies that umount
> > > > should accept the '-n' option, but the binary that is delivered with
> > > > debian does not accept this option. Curiously, mount does.
> > >
> > > The -n option is only available when CONFIG_FEATURE_MTAB_SUPPORT
> > > is enabled....
> >
> > Cool, but why does mount accept the '-n' option when umount does not?
>
> That is not possible. If CONFIG_FEATURE_MTAB_SUPPORT is enabled
> then '-n' would be enabled for both mount and umount. Assuming
> they are both provided by thr same binary...
I agree that it should not be possible ;-)
However:
<--- CUT --->
[1]pwagland@paulw-desktop:~% /bin/busybox umount -n /home
BusyBox v1.00-pre3 (2003.10.21-17:19+0000) multi-call binary
Usage: umount [flags] FILESYSTEM|DIRECTORY
[1]pwagland@paulw-desktop:~% /bin/busybox umount /home
umount: /home: Operation not permitted
[1]pwagland@paulw-desktop:~% /bin/busybox mount -n /home
nfs bindresvport: Permission denied
mount: nfsmount failed: Bad file descriptor
mount: permission denied. (are you root?)
[1]pwagland@paulw-desktop:~% /bin/busybox mount /home
nfs bindresvport: Permission denied
mount: nfsmount failed: Bad file descriptor
mount: permission denied. (are you root?)
<--- CUT --->
As you can see, umount -n does not do anything, and fails to run. umount
with no arguments does run, but as I am not root it fails to complete
;-)
mount with no arguments works, as does mount -n.
> > I assume that CONFIG_FEATURE_MTAB_SUPPORT is a compile time option? Is
> > it possible to get it turned on? :-)
>
> Why? The debian installer has no need for a /etc/mtab file,
Yes, I know. But the -n option says NOT to use the mtab file. It was
stated above that the -n option was enabled by
CONFIG_FEATURE_MTAB_SUPPORT, hence my request to get it enabled. If, by
default it does not use the MTAB, then -n should probably always be
accepted, and this may be why mount works, when umount does not.
Cheers,
Paul
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