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=-7.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 49E9EC19759 for ; Thu, 1 Aug 2019 07:44:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 219FA2087E for ; Thu, 1 Aug 2019 07:44:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730714AbfHAHoG (ORCPT ); Thu, 1 Aug 2019 03:44:06 -0400 Received: from mx2.suse.de ([195.135.220.15]:33404 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726185AbfHAHoG (ORCPT ); Thu, 1 Aug 2019 03:44:06 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 3E2ABB11C; Thu, 1 Aug 2019 07:44:05 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 74FE31E3F4D; Thu, 1 Aug 2019 09:44:04 +0200 (CEST) Date: Thu, 1 Aug 2019 09:44:04 +0200 From: Jan Kara To: Steve Magnani Cc: Roald Strauss , Pali =?iso-8859-1?Q?Roh=E1r?= , Jan Kara , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: UDF filesystem image with Write-Once UDF Access Type Message-ID: <20190801074404.GB25064@quack2.suse.cz> References: <20190712100224.s2chparxszlbnill@pali> <35c0e9f3-b3b6-96c3-e339-2267a3abde9b@digidescorp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <35c0e9f3-b3b6-96c3-e339-2267a3abde9b@digidescorp.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 26-07-19 12:44:34, Steve Magnani wrote: > Hi, > > On 7/12/19 5:02 AM, Pali Rohár wrote: > > In my opinion without support for additional layer, kernel should treat > > UDF Write-Once Access Type as read-only mount for userspace. And not > > classic read/write mount. > > > > ... > > > > It seems that udf.ko does not support updating VAT table, so probably it > > should treat also filesystem with VAT as read-only too. > > > > I thinkb085fbe2ef7fa7489903c45271ae7b7a52b0f9ab , deployed in 4.20, > does both of the things you want. > > One case I ran across today that Windows handles, but Linux doesn't, > is write-protection via flags in the DomainIdentifier fields of the > Logical Volume Descriptor and File Set Descriptor. Linux allows > RW mount when those are marked protected, but Windows forces RO mount. Yeah, you're right. We are currently completely ignoring the DomainIdentifier field and at least for read-write mounts we should make sure it is valid. So that's something that needs fixing. Honza -- Jan Kara SUSE Labs, CR