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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 0AFB5C4338F for ; Fri, 23 Jul 2021 18:56:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E4E4F60F22 for ; Fri, 23 Jul 2021 18:56:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229461AbhGWSQL (ORCPT ); Fri, 23 Jul 2021 14:16:11 -0400 Received: from smtp107.ord1d.emailsrvr.com ([184.106.54.107]:34135 "EHLO smtp107.ord1d.emailsrvr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229878AbhGWSQL (ORCPT ); Fri, 23 Jul 2021 14:16:11 -0400 X-Greylist: delayed 526 seconds by postgrey-1.27 at vger.kernel.org; Fri, 23 Jul 2021 14:16:11 EDT X-Auth-ID: markh@compro.net Received: by smtp6.relay.ord1d.emailsrvr.com (Authenticated sender: markh-AT-compro.net) with ESMTPSA id 579C6E027F; Fri, 23 Jul 2021 14:47:56 -0400 (EDT) From: Mark Hounschell Subject: [BUG] FLOPPY DRIVER since 5.10.20 Reply-To: markh@compro.net To: linux-block@vger.kernel.org, Linux-kernel Cc: Denis Efremov , Jiri Kosina , Mark Hounschell , Greg Kroah-Hartman Organization: Compro Computer Svcs. Message-ID: Date: Fri, 23 Jul 2021 14:47:50 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Classification-ID: c9e847c2-38a7-4e9c-914b-8fd45db953aa-1-1 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org 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. 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. After the patch, if no media is in the drive the open fails with "no such device or address". If the floppy media is write protected the open fails with "Read-only file system". This is certainly drastically changing user land usage incorrectly IMHO. I think the commit is commit 8a0c014cd20516ade9654fc13b51345ec58e7be8 It is the only reference to the floppy driver in ChangeLog-5.10.20. However this change log entry actually sounds like it fixes the very issue I am reporting. Here is the patch from the 5.10.19-20 change. diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c index 7df79ae6b0a1e..295da442329f3 100644 --- a/drivers/block/floppy.c +++ b/drivers/block/floppy.c @@ -4120,23 +4120,23 @@ static int floppy_open(struct block_device *bdev, fmode_t mode) if (fdc_state[FDC(drive)].rawcmd == 1) fdc_state[FDC(drive)].rawcmd = 2; - if (!(mode & FMODE_NDELAY)) { - if (mode & (FMODE_READ|FMODE_WRITE)) { - drive_state[drive].last_checked = 0; - clear_bit(FD_OPEN_SHOULD_FAIL_BIT, - &drive_state[drive].flags); - if (bdev_check_media_change(bdev)) - floppy_revalidate(bdev->bd_disk); - if (test_bit(FD_DISK_CHANGED_BIT, &drive_state[drive].flags)) - goto out; - if (test_bit(FD_OPEN_SHOULD_FAIL_BIT, &drive_state[drive].flags)) - goto out; - } - res = -EROFS; - if ((mode & FMODE_WRITE) && - !test_bit(FD_DISK_WRITABLE_BIT, &drive_state[drive].flags)) + if (mode & (FMODE_READ|FMODE_WRITE)) { + drive_state[drive].last_checked = 0; + clear_bit(FD_OPEN_SHOULD_FAIL_BIT, &drive_state[drive].flags); + if (bdev_check_media_change(bdev)) + floppy_revalidate(bdev->bd_disk); + if (test_bit(FD_DISK_CHANGED_BIT, &drive_state[drive].flags)) + goto out; + if (test_bit(FD_OPEN_SHOULD_FAIL_BIT, &drive_state[drive].flags)) goto out; } + + res = -EROFS; + + if ((mode & FMODE_WRITE) && + !test_bit(FD_DISK_WRITABLE_BIT, &drive_state[drive].flags)) + goto out; + mutex_unlock(&open_lock); mutex_unlock(&floppy_mutex); return 0; Regards Mark