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Date: Tue, 26 Nov 2024 11:25:35 +0100
From: Christoph Hellwig <hch@lst.de>
To: Bart Van Assche <bvanassche@acm.org>
Cc: syzbot <syzbot+f53c29806b4b263165f3@syzkaller.appspotmail.com>,
	axboe@kernel.dk, linux-block@vger.kernel.org,
	linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com,
	Christoph Hellwig <hch@lst.de>, Damien Le Moal <dlemoal@kernel.org>,
	Ming Lei <ming.lei@redhat.com>
Subject: Re: [syzbot] [block?] WARNING in dd_exit_sched
Message-ID: <20241126102535.GA16063@lst.de>
References: <67442263.050a0220.1cc393.0069.GAE@google.com> <2d5e17d7-53a5-4c4e-b961-96a23abfed9f@acm.org>
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On Mon, Nov 25, 2024 at 02:58:55PM -0800, Bart Van Assche wrote:
> All ongoing I/O requests should have completed before elevator_exit() is
> called. del_gendisk() calls __blk_freeze_queue_start() indirectly before
> it calls elevator_exit() but it doesn't wait for the queue freeze
> operation to complete. Isn't that a bug in del_gendisk()?

It does.  This should be fixed by:

https://lore.kernel.org/linux-block/20241126102136.619067-1-hch@lst.de/T/#u