[PATCH RFC 2/2] mtd: ubi: add support for protecting critical volumes

[Richard Weinberger]

----- Ursprüngliche Mail -----
> Von: "Daniel Golle" <daniel at makrotopia.org>
> Allow the boot firmware to define volumes which are critical for the
> system to boot, such as the bootloader itself if stored inside a UBI
> volume. Protect critical volumes by preventing the user from removing,
> resizing or writing to them, and also prevent the UBI device from
> being detached if a critical volume is present.

I agree with the doubts raised in patch 1/2, if userspace is so hostile
to delete system partitions, there is little hope.
But I'm still open for discussion.

What I veto is preventing detach.
This makes a clean tear down of the system impossible.
It becomes more and more common that advanced userspace shuts down
everything it setup during boot. e.g. while reboot switching back
to an initramfs, umounting root, shutting down all storage, etc...

Thanks,
//richard