Return-Path: Received: from fieldses.org ([173.255.197.46]:46352 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422770AbbEOVLf (ORCPT ); Fri, 15 May 2015 17:11:35 -0400 Date: Fri, 15 May 2015 17:11:34 -0400 From: "J. Bruce Fields" To: NeilBrown Cc: Kinglong Mee , linux-fsdevel@vger.kernel.org, "linux-nfs@vger.kernel.org" , Al Viro , Trond Myklebust Subject: Re: [PATCH 4/4] nfsd: Pin to vfsmnt instead of mntget Message-ID: <20150515211134.GG29627@fieldses.org> References: <554A149B.5060102@gmail.com> <554A154B.6040103@gmail.com> <20150508144031.6f0d3cda@notabene.brown> <20150508134744.GA23753@fieldses.org> <5550A9DF.1070908@gmail.com> <20150513142515.6bd881c8@notabene.brown> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20150513142515.6bd881c8@notabene.brown> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Wed, May 13, 2015 at 02:25:15PM +1000, NeilBrown wrote: > On Mon, 11 May 2015 21:08:47 +0800 Kinglong Mee wrote: > > > On 5/8/2015 9:47 PM, J. Bruce Fields wrote: > > > It could also be useful to have the ability to force an unmount even in > > > the presence of locks. That's not a safe default, but an > > > "allow_force_unmount" export option might be useful. > > We already have a mechanism to forcibly drop any locks by writing some magic > to /proc/fs/nfsd/unlock_{ip,filesystem}. I don't think we need any more. Yeah, I remember thinking this sort of approach would have advantages, maybe I was wrong, I need to revisit it. The unlock_{ip,filesystem} approach requires temporarily shutting down mountd, doesn't it? --b.