Re: [PATCH] isar-image-base: fix some dangling mounts

[Christian Storm <christian.storm@siemens.com>]

> [...]
> Here I see that you insert quite similar patterns across the Isar code, 
> would it be better to have one global clean up function like?
> 
> do_isar_mount_cleanup () {
>      if [ -d "${WORKDIR}/mnt" ]; then
>          # umount and remove
>      fi
> 
>      if [ -d "${WORKDIR}/rootfs/proc" ]; then
>          # umount and remove
>      fi
> 
>      if [ -d "${BUILDCHROOT_DIR}/proc" ]; then
>          # umount and remove
>      fi
> 
>      etc...
> }
> 
> This approach will significantly simplify maintenance of clean up traps 
> and adding of new possible mounts to Isar. What do you think?

I'd say it depends :)
It breaks if you rely on keeping something mounted while executing a
child script that does unmount everything, following your proposal. If
we can make sure that such a situation never occurs, we may consolidate
this. For now, it's rather local just undoing the mounts done in the
scope of the script.
So, in the end, I think it's a matter of taste and contracts between the
different parts of Isar.

What one may consider to "de-duplicate" is a stack of mounted directories
being pushed to and unmounted on script exit. So, something like
  push_umount ${IMAGE_ROOTFS}/proc
and then the EXIT trap enumerates all those entries, unmounting them.
The same has to be done for removing the directories, if applicable.



Besten Gru�,
   Christian

-- 
Dr. Christian Storm
Siemens AG, Corporate Technology, CT RDA ITP SES-DE
Otto-Hahn-Ring 6, 81739 M�nchen, Germany