Damaged directory on ZFS

[Harold Paulson]

Hello, 

I've had a server that boots from ZFS panicking for a couple days.  I have worked around the problem for now, but I hope someone can give me some insight into what's going on, and how I can solve it properly.  

The server is running 8.2-STABLE (zfs v28) with 8G of ram and 4 SATA disks in a raid10 type arrangement:

# uname -a              
FreeBSD jane.sierraweb.com 8.2-STABLE-201105 FreeBSD 8.2-STABLE-201105 #0: Tue May 17 05:18:48 UTC 2011     root at mason.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  amd64

And zpool status: 

	NAME           STATE     READ WRITE CKSUM
	tank           ONLINE       0     0     0
	  mirror       ONLINE       0     0     0
	    gpt/disk0  ONLINE       0     0     0
	    gpt/disk1  ONLINE       0     0     0
	  mirror       ONLINE       0     0     0
	    gpt/disk2  ONLINE       0     0     0
	    gpt/disk3  ONLINE       0     0     0

It started panicking under load a couple days ago.  We replaced RAM and motherboard, but problems persisted.  I don't know if a hardware issue originally caused the problem or what.  When it panics, I get the usual panic message, but I don't get a core file, and it never reboots itself.  

http://pastebin.com/F1J2AjSF

While I was trying to figure out the source of the problem, I notice stuck various stuck processes that peg a CPU and can't be killed, such as:

  PID JID USERNAME  THR PRI NICE   SIZE    RES STATE   C   TIME   WCPU COMMAND
48735   0 root        1  46    0 11972K   924K CPU3    3 415:14 100.00% find

They are not marked zombie, but I can't kill them, and restarting the jail they are in won't even get rid of them.  truss just hangs with no output on them.  On different occasions, I noticed pop3d processes for the same user getting stuck in this way.  On a hunch I ran a "find" through the files in the user's Maildir and got a panic.  I disabled this account and now the server is stable again.  At least until locate.updatedb walks through that directory, I suppose.   Evidentially, there is some kind of hole in the file system below that directory tree causing the panic.  

I can move that directory out of the way, and carry on, but is there anything I can do to really *repair* the problem?

Thanks.

	- H