Re: [PATCH] vhost: scsi: constify target_core_fabric_ops structures

From: Michael S. Tsirkin
Date: Tue Jan 10 2017 - 00:14:05 EST


On Mon, Jan 09, 2017 at 08:51:02PM +0530, Bhumika Goyal wrote:
> Declare target_core_fabric_ops strucrues as const as they are only
> passed as an argument to the functions target_register_template and
> target_unregister_template. The arguments are of type const struct
> target_core_fabric_ops *, so target_core_fabric_ops structures having
> this property can be declared const.
> Done using Coccinelle:
>
> @r disable optional_qualifier@
> identifier i;
> position p;
> @@
> static struct target_core_fabric_ops i@p={...};
>
> @ok@
> position p;
> identifier r.i;
> @@
> (
> target_register_template(&i@p)
> |
> target_unregister_template(&i@p)
> )
> @bad@
> position p!={r.p,ok.p};
> identifier r.i;
> @@
> i@p
>
> @depends on !bad disable optional_qualifier@
> identifier r.i;
> @@
> +const
> struct target_core_fabric_ops i;
>
> File size before: drivers/vhost/scsi.o
> text data bss dec hex filename
> 18063 2985 40 21088 5260 drivers/vhost/scsi.o
>
> File size after: drivers/vhost/scsi.o
> text data bss dec hex filename
> 18479 2601 40 21120 5280 drivers/vhost/scsi.o

What are these numbers trying to prove?


> Signed-off-by: Bhumika Goyal <bhumirks@xxxxxxxxx>
> ---
> drivers/vhost/scsi.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
> index 253310c..620366d 100644
> --- a/drivers/vhost/scsi.c
> +++ b/drivers/vhost/scsi.c
> @@ -2087,7 +2087,7 @@ static void vhost_scsi_drop_tport(struct se_wwn *wwn)
> NULL,
> };
>
> -static struct target_core_fabric_ops vhost_scsi_ops = {
> +static const struct target_core_fabric_ops vhost_scsi_ops = {
> .module = THIS_MODULE,
> .name = "vhost",
> .get_fabric_name = vhost_scsi_get_fabric_name,

If it can be const it probably should ...

> --
> 1.9.1