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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 F16FBECDE30 for ; Wed, 17 Oct 2018 15:38:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C3CCB2150F for ; Wed, 17 Oct 2018 15:38:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C3CCB2150F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=xmission.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727760AbeJQXei (ORCPT ); Wed, 17 Oct 2018 19:34:38 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:35502 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727048AbeJQXeh (ORCPT ); Wed, 17 Oct 2018 19:34:37 -0400 Received: from in02.mta.xmission.com ([166.70.13.52]) by out02.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1gCntt-0000bf-2d; Wed, 17 Oct 2018 09:38:21 -0600 Received: from 67-3-154-154.omah.qwest.net ([67.3.154.154] helo=x220.xmission.com) by in02.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1gCnts-00030R-HY; Wed, 17 Oct 2018 09:38:20 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: David Howells Cc: Alan Jenkins , Al Viro , linux-api@vger.kernel.org, torvalds@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, mszeredi@redhat.com References: <87woqgiqta.fsf@xmission.com> <19866.1539782101@warthog.procyon.org.uk> <68a2107f-bf70-055b-86cf-1ba2ba9422bf@gmail.com> <153754740781.17872.7869536526927736855.stgit@warthog.procyon.org.uk> <153754766004.17872.9829232103614083565.stgit@warthog.procyon.org.uk> <9b8bf436-65de-13b9-0002-0479d11c18ca@gmail.com> <20181013061141.GR32577@ZenIV.linux.org.uk> <28710.1539782412@warthog.procyon.org.uk> <13800.1539789863@warthog.procyon.org.uk> Date: Wed, 17 Oct 2018 10:38:04 -0500 In-Reply-To: <13800.1539789863@warthog.procyon.org.uk> (David Howells's message of "Wed, 17 Oct 2018 16:24:23 +0100") Message-ID: <87murcinxf.fsf@xmission.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1gCnts-00030R-HY;;;mid=<87murcinxf.fsf@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=67.3.154.154;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1+BsNEAfi8xRgbj6O2Fenp4z0bOenntuZA= X-SA-Exim-Connect-IP: 67.3.154.154 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: Re: [PATCH 31/34] vfs: syscall: Add fspick() to select a superblock for reconfiguration [ver #12] X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org David Howells writes: > Eric W. Biederman wrote: > >> Davids check will work for bind mounts as well. It just won't work it >> just won't work for files or subdirectories of some mountpoint. > > Bind mounts have to be done with open_tree() and move_mount(). You can't now > do fsmount() on something fspick()'d. But a bind mount will have mnt_root set to the the dentry that was bound. Therefore fspick as you are proposing modifying will work for the root of bind mounts, as well as the root of regular mounts. My apologies for not being clear. Eric