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Date:   Wed, 29 Apr 2020 22:12:29 +0800
From:   Ming Lei <ming.lei@redhat.com>
To:     Martijn Coenen <maco@android.com>
Cc:     axboe@kernel.dk, hch@lst.de, narayan@google.com,
        zezeozue@google.com, kernel-team@android.com, maco@google.com,
        bvanassche@acm.org, Chaitanya.Kulkarni@wdc.com, jaegeuk@kernel.org,
        linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 01/10] loop: Factor out loop size validation
Message-ID: <20200429141229.GE700644@T590>
References: <20200429140341.13294-1-maco@android.com>
 <20200429140341.13294-2-maco@android.com>
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On Wed, Apr 29, 2020 at 04:03:32PM +0200, Martijn Coenen wrote:
> Ensuring we don't truncate loff_t when casting to sector_t is done in
> multiple places; factor it out.
> 
> Signed-off-by: Martijn Coenen <maco@android.com>
> ---
>  drivers/block/loop.c | 25 ++++++++++++++++++++-----
>  1 file changed, 20 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/block/loop.c b/drivers/block/loop.c
> index f1754262fc94..396b8bd4d75c 100644
> --- a/drivers/block/loop.c
> +++ b/drivers/block/loop.c
> @@ -228,15 +228,30 @@ static void __loop_update_dio(struct loop_device *lo, bool dio)
>  		blk_mq_unfreeze_queue(lo->lo_queue);
>  }
>  
> +/**
> + * loop_validate_size() - validates that the passed in size fits in a sector_t
> + * @size: size to validate
> + */
> +static int
> +loop_validate_size(loff_t size)
> +{
> +	if ((loff_t)(sector_t)size != size)
> +		return -EFBIG;
> +
> +	return 0;
> +}
> +

Now sector_t has been switched to u64 unconditionally, do we still need such
validation?


Thanks, 
Ming