Are you sure that it's a terrorist and not linoleum floor layer?
Why would you be on a tourbus nowadays? Are you sure that you can carry on one?
To also play along, drop on your back as he comes at you while drawing your firearm. Use your shoes to deflect any razor attacks while you pop two into COM, or headshot.
Being in a narrow space will really help your defense against a blade.
I guess a face/eye/throat thrust with the cane/umbrella could help to disarm/disorient him, but then you may not have an excuse to shoot him.