From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965979AbaFSVTx (ORCPT ); Thu, 19 Jun 2014 17:19:53 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:51829 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965706AbaFSVTw (ORCPT ); Thu, 19 Jun 2014 17:19:52 -0400 Date: Thu, 19 Jun 2014 14:19:50 -0700 From: Andrew Morton To: Philippe De Muyter Cc: linux-kernel@vger.kernel.org, Al Viro Subject: Re: [PATCH] init/do_mounts.c: treat EROFS like EACCES Message-Id: <20140619141950.18b9026d7d06694291eea311@linux-foundation.org> In-Reply-To: <1403107964-1082-1-git-send-email-phdm@macqel.be> References: <1403107964-1082-1-git-send-email-phdm@macqel.be> X-Mailer: Sylpheed 3.2.0beta5 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 18 Jun 2014 18:12:44 +0200 Philippe De Muyter wrote: > some combinations of filesystem and block device (at least vfat on mmc) > yield -EROFS instead of -EACCES when the device is read-only. Retry > mounting with MS_RDONLY set, just like for the EACCES case, instead of > failing directly. > > ... > > --- a/init/do_mounts.c > +++ b/init/do_mounts.c > @@ -394,6 +394,7 @@ retry: > case 0: > goto out; > case -EACCES: > + case -EROFS: > flags |= MS_RDONLY; > goto retry; > case -EINVAL: hm, what's going on here. I'd have thought it to be very logical that file_system_type.mount() would return EROFS if the device is read-only! But I'm suspecting that there is some convention that the fs is supposed to return EACCES in this case. So *perhaps* it is vfat-on-mmc which needs fixing. Dunno. Al, are you able to shed light?