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Subject: Re: [PATCH 2/2] fs: Remove kiocb->ki_complete
To:     "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc:     linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-aio@kvack.org, io-uring@vger.kernel.org,
        linux-kernel@vger.kernel.org, Kanchan Joshi <joshi.k@samsung.com>,
        Javier Gonzalez <javier.gonz@samsung.com>
References: <20200708222637.23046-1-willy@infradead.org>
 <20200708222637.23046-3-willy@infradead.org>
From:   Jens Axboe <axboe@kernel.dk>
Message-ID: <a0d5c015-1985-280e-2253-8e2663b234e9@kernel.dk>
Date:   Wed, 8 Jul 2020 21:25:03 -0600
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On 7/8/20 4:26 PM, Matthew Wilcox (Oracle) wrote:
> +void unregister_kiocb_completion(int id)
> +{
> +	ki_cmpls[id - 1] = NULL;
> +}
> +EXPORT_SYMBOL(unregister_kiocb_completion);

This should have a limit check (<= 0 || > max).

>  void complete_kiocb(struct kiocb *iocb, long ret, long ret2)
>  {
> -	iocb->ki_complete(iocb, ret, ret2);
> +	unsigned int id = kiocb_completion_id(iocb);
> +
> +	if (id > 0)
> +		ki_cmpls[id - 1](iocb, ret, ret2);
>  }

I'd make id == 0 be a dummy funciton to avoid this branch.

-- 
Jens Axboe