Re: [PATCH rdma-core v2] providers/rxe: Replace '%' with '&' in check_qp_queue_full()

[Bob Pearson <rpearsonhpe@gmail.com>]

On 1/21/22 00:22, Xiao Yang wrote:
> The expression "cons == ((qp->cur_index + 1) % q->index_mask)" doesn't
> check the state of queue (full or empty) correctly.  For example:
> If cons and qp->cur_index are 0 and q->index_mask is 1, the queue is actually
> empty but check_qp_queue_full() reports full (ENOSPC).
> 
> Fixes: 1a894ca10105 ("Providers/rxe: Implement ibv_create_qp_ex verb")
> Signed-off-by: Xiao Yang <yangx.jy@fujitsu.com>
> ---
>  providers/rxe/rxe_queue.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/providers/rxe/rxe_queue.h b/providers/rxe/rxe_queue.h
> index 6de8140c..708e76ac 100644
> --- a/providers/rxe/rxe_queue.h
> +++ b/providers/rxe/rxe_queue.h
> @@ -205,7 +205,7 @@ static inline int check_qp_queue_full(struct rxe_qp *qp)
>  	if (qp->err)
>  		goto err;
>  
> -	if (cons == ((qp->cur_index + 1) % q->index_mask))
> +	if (cons == ((qp->cur_index + 1) & q->index_mask))
>  		qp->err = ENOSPC;
>  err:
>  	return qp->err;
> 
This is fine.

Reviewed-by: Bob Pearson <rpearsonhpe@gmail.com>