Subject: Re: [PATCH] RDS: Simplify code

From: Leon Romanovsky <[email-masked]>
Date: Sun, 4 Sep 2016 15:20:49 +0300

On Sat, Sep 03, 2016 at 07:33:29AM +0200, Christophe JAILLET wrote:
> Calling 'list_splice' followed by 'INIT_LIST_HEAD' is equivalent to
> 'list_splice_init'.

It is not 100% accurate

list_splice(y, z)
INIT_LIST_HEAD(y)

==>

if (!list_empty(y))
     __list_splice(y, z, z>next);
INIT_LIST_HEAD(y)

and not

if (!list_empty(y)) {
     __list_splice(y, z, z>next);
     INIT_LIST_HEAD(y)
}

as list_splice_init will do.

>
> This has been spotted with the following coccinelle script:
> /////
> @@
> expression y,z;
> @@
>
> -   list_splice(y,z);
> -   INIT_LIST_HEAD(y);
> +   list_splice_init(y,z);
>
> Signed-off-by: Christophe JAILLET <[email-masked]>
> ---
>  net/rds/loop.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/net/rds/loop.c b/net/rds/loop.c
> index f2bf78de5688..c3e6da4fdf97 100644
> --- a/net/rds/loop.c
> +++ b/net/rds/loop.c
> @@ -167,8 +167,7 @@ void rds_loop_exit(void)
>
>  	/* avoid calling conn_destroy with irqs off */
>  	spin_lock_irq(&loop_conns_lock);
> -	list_splice(&loop_conns, &tmp_list);
> -	INIT_LIST_HEAD(&loop_conns);
> +	list_splice_init(&loop_conns, &tmp_list);
>  	spin_unlock_irq(&loop_conns_lock);
>
>  	list_for_each_entry_safe(lc, _lc, &tmp_list, loop_node) {
> --
> 2.7.4
>