Return-Path: Received: from exprod5og110.obsmtp.com ([64.18.0.20]:39354 "HELO exprod5og110.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753807Ab0JRRON (ORCPT ); Mon, 18 Oct 2010 13:14:13 -0400 Message-ID: <4CBC805B.60909@panasas.com> Date: Mon, 18 Oct 2010 19:14:03 +0200 From: Boaz Harrosh To: "J. Bruce Fields" CC: Jesper Krogh , Linux NFS Mailing List Subject: Re: lsof and open files from the nfs-server References: <4CB62095.4010708@krogh.cc> <4CBC74E8.7070801@panasas.com> <20101018170459.GA3744@fieldses.org> In-Reply-To: <20101018170459.GA3744@fieldses.org> Content-Type: text/plain; charset=UTF-8 Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On 10/18/2010 07:04 PM, J. Bruce Fields wrote: > On Mon, Oct 18, 2010 at 06:25:12PM +0200, Boaz Harrosh wrote: >> On 10/13/2010 11:11 PM, Jesper Krogh wrote: >>> Hi. >>> >>> Quite often when you have to umount a fileshare you get the >>> message "Device or resource busy". Typically I traverse through >>> the output of lsof | grep mountpoint and stop processes or kill >>> until I can safely umount. >>> >>> But the nfs-kernel-server does not register its open files, so >>> seen from userspace is it extremely hard to find out that is actually >>> is the nfs-server that prevents you from being able to umount >>> the filesystems. >>> >>> Would it be possible to register the open files the same place >>> so administrators can see them? >>> >>> ... basically just a feature-request from one who just spend an hour on >>> that. >>> >> >> Me to! >> >> Also note that even if there are no open files in clients >> and no client mounts on the server, but there where in the >> passed. The used to be used super-block is referenced. Only >> restart of the nfs service will release it. >> >> But yes if it could register as a special file for lsof to >> see it would help a lot. > > So what does lsof do, scan /proc/? Does it make sense to have proc > entries for kernel threads? Is there any other subsystem that does this > kind of thing? > Don't mind if I do ;-) I don't know about policy here and what it actually means (Lifetime rules, module dependency, ...) But it would be nice to have it, as a user. If it can not be added to the regular /proc places. Maybe we can patch lsof to also look in nfs special places and print those as well. > --b. Thanks Boaz