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Date: Fri, 27 Jun 2025 09:17:02 +0200
From: Christoph Hellwig <hch@lst.de>
To: Bart Van Assche <bvanassche@acm.org>
Cc: Jens Axboe <axboe@kernel.dk>, linux-block@vger.kernel.org,
	Christoph Hellwig <hch@lst.de>, Nilay Shroff <nilay@linux.ibm.com>,
	stable@vger.kernel.org
Subject: Re: [PATCH v2] block: Fix a deadlock related to modifying the
 readahead attribute
Message-ID: <20250627071702.GA992@lst.de>
References: <20250626203713.2258558-1-bvanassche@acm.org>
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On Thu, Jun 26, 2025 at 01:37:13PM -0700, Bart Van Assche wrote:
> This deadlock happens because blk_mq_freeze_queue_nomemsave() waits for
> pending requests to finish. The pending requests do never complete because
> the dm-multipath queue_if_no_path option is enabled and the only path in
> the dm-multipath configuration is being removed.

Well, if there are queued never completed bios the freeze will obviously
fail.  I don't see how this freeze is special vs other freezes or other
attributes that freeze.