Re: [PATCH 2/8] io-wq: add helper to merge two wq_lists

[Pavel Begunkov <asml.silence@gmail.com>]

On 9/27/21 7:17 AM, Hao Xu wrote:
> add a helper to merge two wq_lists, it will be useful in the next
> patches.
> 
> Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
> ---
>  fs/io-wq.h | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/fs/io-wq.h b/fs/io-wq.h
> index 8369a51b65c0..7510b05d4a86 100644
> --- a/fs/io-wq.h
> +++ b/fs/io-wq.h
> @@ -39,6 +39,26 @@ static inline void wq_list_add_after(struct io_wq_work_node *node,
>  		list->last = node;
>  }
>  
> +/**
> + * wq_list_merge - merge the second list to the first one.
> + * @list0: the first list
> + * @list1: the second list
> + * after merge, list0 contains the merged list.
> + */
> +static inline void wq_list_merge(struct io_wq_work_list *list0,
> +				     struct io_wq_work_list *list1)
> +{
> +	if (!list1)
> +		return;
> +
> +	if (!list0) {
> +		list0 = list1;

It assigns a local var and returns, the assignment will be compiled
out, something is wrong

> +		return;
> +	}
> +	list0->last->next = list1->first;
> +	list0->last = list1->last;
> +}
> +
>  static inline void wq_list_add_tail(struct io_wq_work_node *node,
>  				    struct io_wq_work_list *list)
>  {
> 

-- 
Pavel Begunkov