Re: kern/45305: umount says device busy without any process having current directory in the mount or file open

[Matthias Kretschmer <kretschm%cs.uni-bonn.de@localhost>]

The following reply was made to PR kern/45305; it has been noted by GNATS.

From: Matthias Kretschmer <kretschm%cs.uni-bonn.de@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: kern-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
        netbsd-bugs%netbsd.org@localhost
Subject: Re: kern/45305: umount says device busy without any process having 
current directory in the mount or file open
Date: Mon, 29 Aug 2011 13:35:46 +0200

 Hello,
 
 
 On Mon, Aug 29, 2011 at 10:25:02AM +0000, matthew green wrote:
 >  what does "fstat" say in this case?  it should report any thing that
 >  is showing an open filesystem.  also, for the killed everything case,
 >  what processes are running?
 
 fstat: the only listed stuff is related to / and no other mount point
 
 Running processes: init, one login, one /bin/sh (fresh root login).
 If I only have those processes running, I would assume that I'm able
 to unmount everything except /?
 
 
 >  also, what about "mount -a"?  fstat doesn't report nullfs mounts that
 >  keep a filesystem busy.
 
 As I required to use the corresponding computer, I need to make it
 behave like this again.  I'll try mount -a and then report, but don't
 understand currently why that should give some insight.  The problem
 mounts are listed as noauto mounts in fstab and thus I assume mount -a
 should do anything about them.
 
 The last time, the nfs-mount got stuck.  The two null-mounts were
 unmounted successfully.
 
 
 --
 Matthias Kretschmer