(Yet Another) Damaged directory on ZFS?

[Andrew Reilly]

On Tue, Nov 01, 2011 at 03:41:18AM +0000, John wrote:
> 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.

Just want to add a sort-of "me too", to this question, in the
hope that I will learn something useful.

For a couple of weeks I've been seeing messages in
my daily security reports along the lines of: find:
/usr/src/.zfs/snapshot: bad file descriptor

I can get the same message now by just cd'ing into one of the
two "broken" .zfs directories and comparing ls -F output with a
version that doesn't check the inode data:

ls: snapshot: Bad file descriptor
shares/

"zfs list -r -t snapshot" shows all of the snapshots created by
my nightly backups to still exist, seemingly.

A zpool scrub tank did not change or make them go away.

No processes appear to be stuck, wedged or otherwise broken.

FWIW I'm running:
FreeBSD johnny.reilly.home 9.0-RC1 FreeBSD 9.0-RC1 #4: Sat Nov  5 14:52:15 EST 2011     root at johnny.reilly.home:/usr/obj/usr/src/sys/GENERIC  amd64

Cheers,

-- 
Andrew