Re: [Qemu-devel] [PATCH] mirror: correct buf_size

[Paolo Bonzini <pbonzini@redhat.com>]

On 14/05/2015 12:07, Wen Congyang wrote:
> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
> ---
>  block/mirror.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/block/mirror.c b/block/mirror.c
> index 58f391a..bb6bc27 100644
> --- a/block/mirror.c
> +++ b/block/mirror.c
> @@ -686,6 +686,10 @@ static void mirror_start_job(BlockDriverState *bs, BlockDriverState *target,
>      s->granularity = granularity;
>      s->buf_size = MAX(buf_size, granularity);
>  
> +    if (s->buf_size % granularity != 0) {
> +        s->buf_size = ROUND_UP(s->buf_size, granularity);
> +    }
> +

Good catch!  But I think the "if" is not needed, and also this removes
the need for the s->buf_size assignment before.

The ROUND_UP is really the only thing that is needed.

Paolo