grep -q '/mnt/usb ' /proc/mounts || sudo mount /mnt/usb
sudo losetup /dev/loop0 /mnt/usb/cjwatson
grep -q '/mnt/usb/keys ' /proc/mounts || sudo mount -t ext2 /dev/loop0 /mnt/usb/keys
grep -q '/mnt/usb ' /proc/mounts || sudo mount /mnt/usb
sudo losetup /dev/loop0 /mnt/usb/cjwatson
grep -q '/mnt/usb/keys ' /proc/mounts || sudo mount -t ext2 /dev/loop0 /mnt/usb/keys