From: Yu Kuai <yukuai3@huawei.com>

For the case nowait in wait_barrier(), there is no point to increase
nr_waiting and then decrease it.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
---
 drivers/md/raid10.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 37fd9284054e..df435d693637 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -990,17 +990,17 @@ static bool wait_barrier(struct r10conf *conf, bool nowait)
 
 	spin_lock_irq(&conf->resync_lock);
 	if (conf->barrier) {
-		conf->nr_waiting++;
 		/* Return false when nowait flag is set */
 		if (nowait) {
 			ret = false;
 		} else {
+			conf->nr_waiting++;
 			raid10_log(conf->mddev, "wait barrier");
 			wait_event_lock_irq(conf->wait_barrier,
 					    stop_waiting_barrier(conf),
 					    conf->resync_lock);
+			conf->nr_waiting--;
 		}
-		conf->nr_waiting--;
 		if (!conf->nr_waiting)
 			wake_up(&conf->wait_barrier);
 	}
-- 
2.31.1

On 2022-09-16 05:34, Yu Kuai wrote:
> From: Yu Kuai <yukuai3@huawei.com>
> 
> For the case nowait in wait_barrier(), there is no point to increase
> nr_waiting and then decrease it.
> 
> Signed-off-by: Yu Kuai <yukuai3@huawei.com>

Reviewed-by: Logan Gunthorpe <logang@deltatee.com>

On 9/16/22 7:34 PM, Yu Kuai wrote:
> From: Yu Kuai <yukuai3@huawei.com>
>
> For the case nowait in wait_barrier(), there is no point to increase
> nr_waiting and then decrease it.
>
> Signed-off-by: Yu Kuai <yukuai3@huawei.com>
> ---
>   drivers/md/raid10.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
> index 37fd9284054e..df435d693637 100644
> --- a/drivers/md/raid10.c
> +++ b/drivers/md/raid10.c
> @@ -990,17 +990,17 @@ static bool wait_barrier(struct r10conf *conf, bool nowait)
>   
>   	spin_lock_irq(&conf->resync_lock);
>   	if (conf->barrier) {
> -		conf->nr_waiting++;
>   		/* Return false when nowait flag is set */
>   		if (nowait) {
>   			ret = false;
>   		} else {
> +			conf->nr_waiting++;
>   			raid10_log(conf->mddev, "wait barrier");
>   			wait_event_lock_irq(conf->wait_barrier,
>   					    stop_waiting_barrier(conf),
>   					    conf->resync_lock);
> +			conf->nr_waiting--;
>   		}
> -		conf->nr_waiting--;
>   		if (!conf->nr_waiting)
>   			wake_up(&conf->wait_barrier);
>   	}

Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>

Thanks,
Guoqing