Re: [PULL 5/5] virtio/s390: virtio: constify virtio_config_ops structures

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Jan 16, 2017 at 03:04:33PM +0100, Cornelia Huck wrote:
> From: Bhumika Goyal <bhumirks@gmail.com>
> 
> Declare virtio_config_ops structure as const as it is only stored in the
> config field of a virtio_device structure. This field is of type const, so
> virtio_config_ops structures having this property can be declared const.
> Done using Coccinelle:
> 
> @r1 disable optional_qualifier@
> identifier i;
> position p;
> @@
> static struct virtio_config_ops i@p={...};
> 
> @ok1@
> identifier r1.i;
> position p;
> struct virtio_ccw_device x;
> @@
> x.vdev.config=&i@p
> 
> @bad@
> position p!={r1.p,ok1.p};
> identifier r1.i;
> @@
> i@p
> 
> @depends on !bad disable optional_qualifier@
> identifier r1.i;
> @@
> +const
> struct virtio_config_ops i;
> 
> File size before and after applying the patch remains the same.
> text	data	bss	dec	hex   filename
> 9235	296	32928	42459	a5db  drivers/s390/virtio/virtio_ccw.o
> 
> Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
> Message-Id: <1484333336-13443-1-git-send-email-bhumirks@gmail.com>
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>

I am frankly puzzled by this reporting on file sizes.
So what does it mean that it's the same?

> ---
>  drivers/s390/virtio/virtio_ccw.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c
> index 0672c6234ae8..070c4da95f48 100644
> --- a/drivers/s390/virtio/virtio_ccw.c
> +++ b/drivers/s390/virtio/virtio_ccw.c
> @@ -944,7 +944,7 @@ static void virtio_ccw_set_status(struct virtio_device *vdev, u8 status)
>  	kfree(ccw);
>  }
>  
> -static struct virtio_config_ops virtio_ccw_config_ops = {
> +static const struct virtio_config_ops virtio_ccw_config_ops = {
>  	.get_features = virtio_ccw_get_features,
>  	.finalize_features = virtio_ccw_finalize_features,
>  	.get = virtio_ccw_get_config,
> -- 
> 2.11.0