Hullo, It was pointed out to me that the current licence (‘gpl2+’) for btrfs-progs is just wrong and should be ‘gpl2’ instead.
I must have opened one of the few gpl2+-licenced files in the tarball by sheer bad luck. Here is a patch to set things right. Kind regards, T G-R (I struggled to write a ‘GNU-style’ commit message for something so trivial and probably went overboard. This can be fixed in a later patch series.)