From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753332AbbC0Vmk (ORCPT ); Fri, 27 Mar 2015 17:42:40 -0400 Received: from mail-yh0-f44.google.com ([209.85.213.44]:36169 "EHLO mail-yh0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751634AbbC0Vmi (ORCPT ); Fri, 27 Mar 2015 17:42:38 -0400 MIME-Version: 1.0 In-Reply-To: <1427488774-5077-1-git-send-email-avagin@openvz.org> References: <1427488774-5077-1-git-send-email-avagin@openvz.org> Date: Fri, 27 Mar 2015 22:42:37 +0100 Message-ID: Subject: Re: [PATCH] fs: show locked and lock_ro options in mountinfo From: Richard Weinberger To: Andrey Vagin Cc: linux-fsdevel , LKML , Cyrill Gorcunov , Pavel Emelyanov , "Eric W. Biederman" , Alexander Viro Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 27, 2015 at 9:39 PM, Andrey Vagin wrote: > I don't see any reasons to hide them. This information can help to > understand errors. Because these flags are set/read only internally by the VFS. In contrast to the other flags shown by mountinfo MNT_LOCKED is not a mount option. Why does it help to debug errors? How would a user know that mount() with MS_BIND returns EINVAL because the mount source is MNT_LOCKED? This information is useless for her. If you argue like that you'd have to expose the whole VFS state to userland. > And this information is required for correct checkpoint/restore of mount > namespaces. Why especially MNT_LOCKED and not all the other flags used by VFS? Say MNT_DOOMED? -- Thanks, //richard