From mboxrd@z Thu Jan  1 00:00:00 1970
From: "K. Richard Pixley" <rich@noir.com>
Subject: can't unmount
Date: Thu, 12 Aug 2010 08:55:21 -0700
Message-ID: <4C641969.9070405@noir.com>
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To: linux-btrfs@vger.kernel.org
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  I'm running into a situation where I can't unmount a mounted 
snapshot.  It shows "busy" even though neither lsof nor fuser show any 
open files.  Umount -f doesn't work although umount -l does.

Is there anything else I can do to debug this scenario or to clear the 
busy status myself?  Or am I down to rebooting each time?

This is on stock ubuntu-10.04, x86.

--rich