Infrastructure Software

Now, what's this thing up to?
Suddenly, I find I can't do "df", since this message then appears:
df: a line in /etc/mnttab has to many fields
(sic, "to" should be spelled "too"!)

Looking at /etc/mnttab, I see a reference to:
-xfn /xfn autofs indirect,ignore,dev=3400003 984586559

but now there's a bunch of lines like:
-xfn/_x500 /xfn/_x500 autofs ignore,nest,dev=3400013 984589618

Obviously, there's a connection, since the other anomaly is I suddenly have a /xfn directory, which wasn't there before.
What's in /xfn, I hear you ask? I can't tell. "ls" hangs for ever, but only for that directory. Maybe there's a recursion of nasty directories ad infinitum.

I think rebooting clears everything, but that's only a temporary solution.

Thanks!