[Grml] [PATCH] grml-chroot enhance: fail-safe when umount fails

[Michael Gebetsroither]

Tong Sun wrote:
> Revisiting an old issue.
> 
> On Sat, Nov 29, 2008 at 11:11 AM, Michael Gebetsroither
> <gebi at sbox.tugraz.at <mailto:gebi at sbox.tugraz.at>> wrote:
> 
>     Tong Sun wrote:
> 
>     NACK as this causes problems with multiple grml-chroots running.
> 
>     > ---
>     >  usr_sbin/grml-chroot |    2 +-
>     >  1 files changed, 1 insertions(+), 1 deletions(-)
>     >
>     > diff --git a/usr_sbin/grml-chroot b/usr_sbin/grml-chroot
>     > index eb9cefc..bce9c50 100755
>     > --- a/usr_sbin/grml-chroot
>     > +++ b/usr_sbin/grml-chroot
>     > @@ -56,7 +56,7 @@ function mountit
>     >  function umount_all
>     >  {
>     >      for i in $MOUNTED_; do
>     > -        umount "${DEST_}/$i"
>     > +        umount "${DEST_}/$i" || umount -l "${DEST_}/$i"
>     >      done
>     >  }
>     >
> 
> 
> In this case, the sentence in man, "After COMMAND exits, mounts are
> cleaned up properly." might not be always correct.

Right, it's not entirely correct. If you close multiple grml-chroot
instances in the wrong order you will experience mountpoints from
grml-chroot not cleand up. And get the appropriate error messages.

Though your patch destroys _every_ other grml-chroot instance running in
parallel because you just unmount filesystems which are in use.

greets,
michael