Re: [PATCH] net/mlx5: release spinlock before return from function

["Nélio Laranjeiro" <nelio.laranjeiro@6wind.com>]

Hi Pavlo,

On Fri, Sep 29, 2017 at 03:03:56AM +0300, Pavlo Shcherbyna wrote:
> If priv_ethtool_get_stats_n fails to retrieve statistics, lock
> is not released. Next call of function, which uses the same
> spinlock, will stuck trying to obtain it.
> 
> This patch addresses the issue.
> 
> Fixes: 4b2e6df26168 ("net/mlx5: fix extended statistics counters identification")
> Cc: shahafs@mellanox.com
> 
> Signed-off-by: Pavlo Shcherbyna <pavlo.shcherbyna@harmonicinc.com>
> ---
>  drivers/net/mlx5/mlx5_stats.c |    8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/mlx5/mlx5_stats.c b/drivers/net/mlx5/mlx5_stats.c
> index 703f48c..8764829 100644
> --- a/drivers/net/mlx5/mlx5_stats.c
> +++ b/drivers/net/mlx5/mlx5_stats.c
> @@ -442,8 +442,10 @@ struct mlx5_counter_ctrl {
> 
>  		priv_lock(priv);
>  		stats_n = priv_ethtool_get_stats_n(priv);
> -		if (stats_n < 0)
> +		if (stats_n < 0) {
> +			priv_unlock(priv);
>  			return -1;
> +		}
>  		if (xstats_ctrl->stats_n != stats_n)
>  			priv_xstats_init(priv);
>  		ret = priv_xstats_get(priv, stats);
> @@ -467,8 +469,10 @@ struct mlx5_counter_ctrl {
> 
>  	priv_lock(priv);
>  	stats_n = priv_ethtool_get_stats_n(priv);
> -	if (stats_n < 0)
> +	if (stats_n < 0) {
> +		priv_unlock(priv);
>  		return;
> +	}
>  	if (xstats_ctrl->stats_n != stats_n)
>  		priv_xstats_init(priv);
>  	priv_xstats_reset(priv);
> --
> 1.7.10.4

This bug is already fixed in next-net/master [1][2].

Thanks for your contribution.

[1] http://dpdk.org/ml/archives/dev/2017-August/072864.html
[2] http://dpdk.org/ml/archives/dev/2017-August/073404.html

-- 
Nélio Laranjeiro
6WIND