elif [ -n "${opt_bind}" -o -n "${opt_union}" ] && [ -n "${PERSISTENCE_READONLY}" ]
then
# bind-mount and union mount are handled the same
# in read-only mode, but note that rootfs_dest_backing
# is non-empty (and necessary) only for unions
elif [ -n "${opt_bind}" -o -n "${opt_union}" ] && [ -n "${PERSISTENCE_READONLY}" ]
then
# bind-mount and union mount are handled the same
# in read-only mode, but note that rootfs_dest_backing
# is non-empty (and necessary) only for unions