1993 Isuzu Rodeo Clutch Failure?

V6, Manual (5-speed), LS Package, rear disk brakes. Clutch pedal travels to floor with no discernible effect. Can shift between gears with engine running with no grab at all. Clutch master cylinder was low on fluid. Filled oil, tested, no change. Did not observe an oil leak at the master cylinder. Before it went out reverse was occasionally hard to get into.