cbd967cd2a
Previously, when the graphdir was a root of a mountpoint, we would not be able to cleanup the graphdir, as the script would umount in case target dir is a mount itself ```/etc/mtab /dev/xvdc1 /var/lib/docker btrfs ``` When running the script, the graphdir would be unmounted and it would remove a (possibly) empty folder. ``` Nuking /var/lib/docker ... (if this is wrong, press Ctrl+C NOW!) + sleep 10 + umount -f /var/lib/docker + rm -rf /var/lib/docker ``` This PR includes the necessary changes to nuke the folder on this scenario, including when the graphdir is a btrfs mount iself. Signed-off-by: Bruno Tavares <btavare@thoughtworks.com> Upstream-commit: 5f98b977496b5c8430162b129cb94c88efb0f3b6 Component: engine