Hard lockup after / became full

Bento locked up hard overnight, such that I could not even break to
the debugger.  The timeline of events seems to be:

Mar 29 05:10:02 <kern.err> bento kernel: pid 46625 (locate.code), uid 65534 inumber 16041 on /: filesystem full

Some time between 5:15 and 5:20 the system locked up completely.  It
was in the middle of a package build (and daily maintenance) at the
time, so it was under fairly heavy disk and network load.

I'll try and reproduce this sometime when I can spare bento, however I
suspect it's not going to be easy to trigger :(

Kris