From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: 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 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> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [PATCH 31/34] vfs: syscall: Add fspick() to select a superblock for reconfiguration [ver #12] Sender: linux-fsdevel-owner@vger.kernel.org List-ID: 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