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Date:   Wed, 29 Dec 2021 18:29:02 +0100
From:   Christoph Hellwig <hch@lst.de>
To:     Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc:     Jens Axboe <axboe@kernel.dk>, Jan Kara <jack@suse.cz>,
        Dan Schatzberg <schatzberg.dan@gmail.com>,
        Christoph Hellwig <hch@lst.de>,
        linux-block <linux-block@vger.kernel.org>
Subject: Re: [PATCH] make autoclear operation synchronous again
Message-ID: <20211229172902.GC27693@lst.de>
References: <03f43407-c34b-b7b2-68cd-d4ca93a993b8@i-love.sakura.ne.jp>
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The subject line is missing the loop: prefix.

This approach looks very reasonable, but a few comments below:

> -	lo->workqueue = alloc_workqueue("loop%d",
> -					WQ_UNBOUND | WQ_FREEZABLE,
> -					0,
> -					lo->lo_number);
> +	if (!lo->workqueue)
> +		lo->workqueue = alloc_workqueue("loop%d",
> +						WQ_UNBOUND | WQ_FREEZABLE,
> +						0, lo->lo_number);

Instead of having to deal with sometimes present workqueues, why
not move the workqueue allocation to loop_add?

> +	/* This is safe: open() is still holding a reference. */
> +	module_put(THIS_MODULE);

Any reason to move the module_put here insted of keeping it at the
end of the function as the old code did?