7830091c4b
This removes and recreates the merged dir with each umount/mount respectively. This is done to make the impact of leaking mountpoints have less user-visible impact. It's fairly easy to accidentally leak mountpoints (even if moby doesn't, other tools on linux like 'unshare' are quite able to incidentally do so). As of recently, overlayfs reacts to these mounts being leaked (see One trick to force an unmount is to remove the mounted directory and recreate it. Devicemapper now does this, overlay can follow suit. Signed-off-by: Euan Kemp <euan.kemp@coreos.com> Upstream-commit: af0d589623eff9f8cefced8b527dbd7cf221ce61 Component: engine