Clutch pedal stuck to floor

[atropine]

Hi All-

I know this has been covered before, but I have a very specific question that I didn't see covered in past threads.

I have a 2009 6MT with 40k miles. 98% freeway miles. Never had a problem until Saturday. Then all of a sudden, clutch pedal goes to floor and doesn't return quickly. Difficult to get car into gear. Now It won't go into gear at all. I can manually pull pedal back out, but in it's natural state it just wants to stay on the floor when I press it in. Clutch reservoir is full. Car has not been leaking any fluid. Clutch fluid is a little dirty, but it is completely full. Wondering if I have a CSC failure. I have an extended 75k mile warranty. I thought that in most CSC failures that fluid level would be low. So I called dealer, and service guy said that he has seen them fail internally before so it is possible to have CSC failure with full fluid in reservoir. But before I get it towed in, I'm wondering if anyone else on here has had CSC failure with no fluid loss......