From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-nfs-owner@vger.kernel.org>
X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on
	aws-us-west-2-korg-lkml-1.web.codeaurora.org
Received: from vger.kernel.org (vger.kernel.org [23.128.96.18])
	by smtp.lore.kernel.org (Postfix) with ESMTP id E1473C77B73
	for <linux-nfs@archiver.kernel.org>; Thu, 20 Apr 2023 21:35:42 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S232465AbjDTVfl (ORCPT <rfc822;linux-nfs@archiver.kernel.org>);
        Thu, 20 Apr 2023 17:35:41 -0400
Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52612 "EHLO
        lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S231376AbjDTVfk (ORCPT
        <rfc822;linux-nfs@vger.kernel.org>); Thu, 20 Apr 2023 17:35:40 -0400
Received: from zeniv.linux.org.uk (zeniv.linux.org.uk [IPv6:2a03:a000:7:0:5054:ff:fe1c:15ff])
        by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DDB9959F8;
        Thu, 20 Apr 2023 14:35:35 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed;
        d=linux.org.uk; s=zeniv-20220401; h=Sender:In-Reply-To:Content-Type:
        MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To:
        Content-Transfer-Encoding:Content-ID:Content-Description;
        bh=XdPzgZMga4nxCngAf5Uk4oKS+beDjYzCM1eCd0jiQBA=; b=Izx7MYewJXzDPQyTvwJddCGkk2
        J4g7k/NJcTTr6noFbMY8sEkbMSb5wGamu45DmAVAXmPVwUazWDXuduj1qJr4tdwMtR95s3zttJPoJ
        zu98Ixjbug4mWHQPTTivKHw6b96+YzIK6ejpVJh55L0un51eZvjpeLrAiVRKRWte5+7BTpwmPUhE3
        gVPL5noyX99klWH1GQZTNIZ/8XcDiMMIhvM/KeP+ruLDEu416Wg6xKS9qCyF7w3DmuK54B93ntI2R
        73sVv84JMfFN1QsCAh+1StpTbnZV8lRC7fdNkZuASIo5SUUx6D20HX3QklDI1mq2G8bjUd4EBExa4
        QYwtO41Q==;
Received: from viro by zeniv.linux.org.uk with local (Exim 4.96 #2 (Red Hat Linux))
        id 1ppbw9-00AxwI-2n;
        Thu, 20 Apr 2023 21:35:30 +0000
Date:   Thu, 20 Apr 2023 22:35:29 +0100
From:   Al Viro <viro@zeniv.linux.org.uk>
To:     NeilBrown <neilb@suse.de>
Cc:     Christian Brauner <brauner@kernel.org>,
        Jeff Layton <jlayton@kernel.org>,
        Dave Wysochanski <dwysocha@redhat.com>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        linux-nfs <linux-nfs@vger.kernel.org>,
        David Howells <dhowells@redhat.com>,
        Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH/RFC] VFS: LOOKUP_MOUNTPOINT should used cached info
 whenever possible.
Message-ID: <20230420213529.GS3390869@ZenIV>
References: <95ee689c76bf034fa2fe9fade0bccdb311f3a04f.camel@kernel.org>
 <168168683217.24821.6260957092725278201@noble.neil.brown.name>
 <20230417-beisein-investieren-360fa20fb68a@brauner>
 <168176679417.24821.211742267573907874@noble.neil.brown.name>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <168176679417.24821.211742267573907874@noble.neil.brown.name>
Sender: Al Viro <viro@ftp.linux.org.uk>
Precedence: bulk
List-ID: <linux-nfs.vger.kernel.org>
X-Mailing-List: linux-nfs@vger.kernel.org

On Tue, Apr 18, 2023 at 07:26:34AM +1000, NeilBrown wrote:

> MNT_FORCE is, I think, a good idea and a needed functionality that has
> never been implemented well.
> MNT_FORCE causes nfs_umount_begin to be called as you noted, which
> aborts all pending RPCs on that filesystem.

Suppose it happens to be mounted in another namespace as well.  Or bound
at different mountpoint, for that matter.  What should MNT_FORCE do?