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=-5.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 A6117C4338F for ; Mon, 26 Jul 2021 12:31:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8894F604AC for ; Mon, 26 Jul 2021 12:31:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234096AbhGZLvY (ORCPT ); Mon, 26 Jul 2021 07:51:24 -0400 Received: from smtp99.ord1c.emailsrvr.com ([108.166.43.99]:46334 "EHLO smtp99.ord1c.emailsrvr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234161AbhGZLvP (ORCPT ); Mon, 26 Jul 2021 07:51:15 -0400 X-Greylist: delayed 473 seconds by postgrey-1.27 at vger.kernel.org; Mon, 26 Jul 2021 07:51:13 EDT X-Auth-ID: markh@compro.net Received: by smtp13.relay.ord1c.emailsrvr.com (Authenticated sender: markh-AT-compro.net) with ESMTPSA id C6730A0115; Mon, 26 Jul 2021 08:23:48 -0400 (EDT) Reply-To: markh@compro.net Subject: Re: [BUG] FLOPPY DRIVER since 5.10.20 To: Denis Efremov , dmarkh@cfl.rr.com, linux-block@vger.kernel.org, Linux-kernel Cc: Jiri Kosina , Greg Kroah-Hartman References: From: Mark Hounschell Organization: Compro Computer Svcs. Message-ID: <1cf8e751-db77-441e-53b4-d6e979bbe046@compro.net> Date: Mon, 26 Jul 2021 08:23:48 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Classification-ID: 0104ae61-b9b1-446d-a266-59dbbb31ebfc-1-1 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 7/26/21 7:37 AM, Denis Efremov wrote: > > > On 7/26/21 2:17 PM, Mark Hounschell wrote: >> On 7/26/21 3:57 AM, Denis Efremov wrote: >>> Hi, >>> >>> On 7/23/21 9:47 PM, Mark Hounschell wrote: >>>> >>>> These 2 incremental patches, patch-5.10.19-20 and patch-5.11.2-3 have broken the user land fd = open("/dev/fd0", (O_RDWR | O_NDELAY)); functionality. >>> >>> Thank you for the report, I'm looking into this. >>> >>>> Since FOREVER before the patch, when using O_NDELAY, one could open the floppy device with no media inserted or even with write protected media without error. "Read-only file system" status is returned only when we actually tried to write to it. We have software still in use today that relies on this functionality. >>> >>> If it's a project with open sources could you please give a link? >>> >>> Regards, >>> Denis >>> >> This is immaterial but fdutils and libdsk both use rely on this flag. Who can know who else does. The point is it should NOT have been changed. > > Yes, I asked this only to add utils and this behavior to the tests. > And be more specific about why we should preserve this behavior in > next commit messages. > Well, first thing is now you can't open a floppy with a write protected floppy installed. I don't think that was intended but that is now how it is. Next there are commands that can be sent to the floppy via "ioctl(fd, FDRAWCMD, &raw_cmd);" that do NOT require a floppy diskette to be installed. All commands issued to the device that require a floppy diskette without a diskette installed fail with the proper status letting you know the device is not ready / no diskette installed. That goes for write protected floppies too. There is no reason to force a user to only be able to operate on Linux fdformat formatted floppies. Regards Mark