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Date:   Mon, 3 May 2021 17:53:45 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Daniel Wagner <dwagner@suse.de>
Cc:     linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org,
        Hannes Reinecke <hare@suse.de>,
        Keith Busch <kbusch@kernel.org>, Jens Axboe <axboe@fb.com>,
        Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH] nvme-multipath: Reset bi_disk to ns head when failover
Message-ID: <20210503155345.GA5342@lst.de>
References: <20210503125741.68117-1-dwagner@suse.de>
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On Mon, May 03, 2021 at 02:57:41PM +0200, Daniel Wagner wrote:
> The path can be stale when we failover. If we don't reset the bdev to
> the ns head and the I/O finally completes in end_io() it will triggers
> a crash. By resetting the to ns head disk so that the submit path can
> map the request to an active path.
> 
> Signed-off-by: Daniel Wagner <dwagner@suse.de>
> ---
> 
> The patch is against nvme-5.13.

There is no bi_disk in nvme-5.13, but fortunately that slipped in only
in the subject.

> +	bdev = bdget_disk(ns->head->disk, 0);

Please just use ns->head->disk->part0 directly.  No need for the
reference and bdget_disk is about to go away.