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 46C90C04AB6 for ; Tue, 28 May 2019 23:08:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1ABB420989 for ; Tue, 28 May 2019 23:08:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727103AbfE1XIm convert rfc822-to-8bit (ORCPT ); Tue, 28 May 2019 19:08:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33546 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726653AbfE1XIk (ORCPT ); Tue, 28 May 2019 19:08:40 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A8A59300C035; Tue, 28 May 2019 23:08:40 +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 BB663611B4; Tue, 28 May 2019 23:08:38 +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: <10418.1559084686@warthog.procyon.org.uk> References: <10418.1559084686@warthog.procyon.org.uk> <155905930702.7587.7100265859075976147.stgit@warthog.procyon.org.uk> <155905933492.7587.6968545866041839538.stgit@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: <30027.1559084917.1@warthog.procyon.org.uk> Content-Transfer-Encoding: 8BIT Date: Wed, 29 May 2019 00:08:37 +0100 Message-ID: <30028.1559084917@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.49]); Tue, 28 May 2019 23:08:40 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org David Howells wrote: > > It might make sense to redesign this stuff so that watches don't hold > > references on the object being watched. > > I explicitly made it hold a reference so that if you place a watch on an > automounted mount it stops it from expiring. > > Further, if I create a watch on something, *should* it be unmountable, just as > if I had a file open there or had chdir'd into there? It gets trickier than that as I need a ref on the dentry on which the watch is rooted to prevent it from getting culled. David