From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ming Lei <ming.lei@redhat.com>
Subject: Re: [PATCH 3/3] blk-cgroup: only grab an inode reference to the disk
 for each blkg
Date: Mon, 13 Feb 2023 20:11:36 +0800
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 <20230213104134.475204-4-hch@lst.de>
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To: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>, Tejun Heo <tj@kernel.org>, Josef Bacik <josef@toxicpanda.com>, cgroups@vger.kernel.org, linux-block@vger.kernel.org, ming.lei@redhat.com

On Mon, Feb 13, 2023 at 11:41:34AM +0100, Christoph Hellwig wrote:
> To avoid a circular reference, do not grab a device model reference
> to the gendisk for each blkg, but just the lower level inode reference
> preventing the memory from beeing freed.

It might not be enough to just prevent gendisk memory from being freed,
anywhere queue reference via disk->queue could become not safe given
disk->queue can be released after disk_release() is called.

thanks,
Ming