From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B60FBC28CC2 for ; Wed, 29 May 2019 11:16:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 901E320B7C for ; Wed, 29 May 2019 11:16:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726863AbfE2LQa (ORCPT ); Wed, 29 May 2019 07:16:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45834 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726787AbfE2LQa (ORCPT ); Wed, 29 May 2019 07:16:30 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 0C786300CA98; Wed, 29 May 2019 11:16:30 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-120-173.rdu2.redhat.com [10.10.120.173]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4D7B55D756; Wed, 29 May 2019 11:16:28 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: <155905930702.7587.7100265859075976147.stgit@warthog.procyon.org.uk> <155905933492.7587.6968545866041839538.stgit@warthog.procyon.org.uk> <10418.1559084686@warthog.procyon.org.uk> To: Jann Horn Cc: dhowells@redhat.com, Al Viro , raven@themaw.net, linux-fsdevel , Linux API , linux-block@vger.kernel.org, keyrings@vger.kernel.org, linux-security-module , kernel list Subject: Re: [PATCH 3/7] vfs: Add a mount-notification facility MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <15838.1559128587.1@warthog.procyon.org.uk> Date: Wed, 29 May 2019 12:16:27 +0100 Message-ID: <15839.1559128587@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Wed, 29 May 2019 11:16:30 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jann Horn wrote: > I don't really know. I guess it depends on how it's being used? If > someone decides to e.g. make a file browser that installs watches for > a bunch of mountpoints for some fancy sidebar showing the device > mounts on the system, or something like that, that probably shouldn't > inhibit unmounting... I don't know if that's a realistic use case. In such a use case, I would envision the browser putting a watch on "/". A watch sees all events in the subtree rooted at that point and you must apply a filter that filters them out if you're not interested (filter on WATCH_INFO_IN_SUBTREE using info_filter and info_mask). David