(Yet Another) Damaged directory on ZFS?

[John]

Hi Folks,

   We have a zfs fileserver running 9.0-RC1 which appears to have locked
up in a manner similar to the "Damanged directory on ZFS" thread.

   It started after a zfs snapshat which appears to have hung. At
that point, an "ls" command on a directory which is either empty
or contains only other directories works correctly. An "ls" on
a directory containing a file will hang.

   The OS is installed on an OCZ card with UFS, ZFS is only used for
the data volume.


   The following information is rather large and is available
here: http://people.freebsd.org/~jwd/tx_sync_done.html

On the page:

zfs snapshot (which appears to have caused the issue)
an ls that works (on empty or directory with only directories)
an ls that hangs (directory contains files)
zpool history that hangs
ps -auxww
procstat -kk -a
zpool status
zfs list
df -hl
zfs list -t
sysctl -a (Very, Very large)
uname -a (as below)

FreeBSD server1 9.0-RC1 FreeBSD 9.0-RC1 #0 r226607M: Fri Oct 21 11:32:01 EDT 2011     neh at server1:/usr/obj/usr/src.2011-10-21_01.37.40/sys/ZFS  amd64

The system is sitting idle at this point if we can provide
any additional debugging informtion.

Please let me know.

Thanks,
John