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Date:   Wed, 30 Nov 2022 05:56:08 -0800
From:   Christoph Hellwig <hch@infradead.org>
To:     Jan Kara <jack@suse.cz>
Cc:     Christoph Hellwig <hch@infradead.org>,
        Jens Axboe <axboe@kernel.dk>, linux-block@vger.kernel.org
Subject: Re: Partitions created under RAID devices
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On Wed, Nov 30, 2022 at 02:53:44PM +0100, Jan Kara wrote:
> As I've studied history behind partition rescanning I understand it is
> difficult to please everybody :). But creating partitions under assembled
> RAID device looks wrong to me. So I was wondering - couldn't
> disk_scan_partitions() just refuse to operate on the device if there's
> another exclusive opener (it will be a bit painful to do the check but it
> is doable)? That will fix this problem with RAID and should
> not be prone to races with udev or similar problems causing troubles in the
> past. What do people think?

Yes, that seems like a very reasonable thing to do.