[RHEL6.1] process stuck on autofs4_wait

Issue

I have machines running RHEL 6.1, and like all of our other machines they depend on lots of NFS mounts controlled by the automounter.

We've noticed some processes getting stuck with autofs4_wait in wchan.

I should also note that attempting to automount any other mounts gets stuck in autofs4_wait too, so the machine is effectively useless to us when it gets in this state.