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Subject: Re: [BUG] FLOPPY DRIVER since 5.10.20
To:     dmarkh@cfl.rr.com, markh@compro.net, linux-block@vger.kernel.org,
        Linux-kernel <linux-kernel@vger.kernel.org>
Cc:     Jiri Kosina <jkosina@suse.cz>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
References: <de10cb47-34d1-5a88-7751-225ca380f735@compro.net>
 <e49603c2-ac36-12b0-57cf-ff5ab30115bc@linux.com>
 <f5501a7c-4387-259d-66d2-f10db0cf36ff@cfl.rr.com>
From:   Denis Efremov <efremov@linux.com>
Message-ID: <f1277dcb-6bf8-b149-ad4e-68a4109d4e67@linux.com>
Date:   Mon, 26 Jul 2021 14:37:09 +0300
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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.

Denis