rsync + hammer + nfs = trouble

[Matthew Dillon]

:Tried using hammer for the first time today. Created a hammer volume on
:two partitions, exported it over nfs, mounted it on my fileserver and
:tried rsyncing some GB of data. After 20+ GB, the machine starts acting
:up: I can't start new processes (command line editing over ssh works though)
:and the rsync processes on the non-dfly box is stuck. Taking a look at the
:console, I can see three "cache_lock: blocked on 0x... (.filename.c.garbage)"
:messages. Some nfs-hammer interaction perhaps?
:
:Aggelos

    It sounds like a buffer cache deadlock, which should be easy for me to
    fix.  Were you reading from the NFS mount or writing to the NFS mount?

    I'm assuming you are running the latest HEAD.  If so, please drop
    into the debugger (e.g. ctl-alt-esc) and generate a crash dump, and
    get it onto leaf so I can take a look.

					-Matt
					Matthew Dillon 
					<dillon at backplane.com>