processes stuck in "zfs" state when opening a directory

[Alan Grow]

Hello,

After a recent bout of intense filesystem activity, processes on an 
8.0-RELEASE box are getting stuck in the "zfs" state when they try to 
open a certain directory. A zfs scrub shows no errors. Neither does 
smartctl. Nothing in the system logs.

Is there anything I can do to help narrow down the problem? 
Unfortunately I don't have console access.

Thanks,

-Alan