Re: [PATCH net v2] net/smc: Remove redundant refcount increase

From: Tony Lu <tonylu@linux.alibaba.com>
To: liuyacan@corp.netease.com
Cc: davem@davemloft.net, edumazet@google.com, kgraul@linux.ibm.com,
	kuba@kernel.org, linux-kernel@vger.kernel.org,
	linux-s390@vger.kernel.org, netdev@vger.kernel.org,
	pabeni@redhat.com, wenjia@linux.ibm.com, hwippel@linux.ibm.com,
	ubraun@linux.ibm.com
Subject: Re: [PATCH net v2] net/smc: Remove redundant refcount increase
Date: Thu, 1 Sep 2022 14:49:59 +0800	[thread overview]
Message-ID: <YxBWF7QCN+TnLk+4@TonyMac-Alibaba> (raw)
In-Reply-To: <20220830152314.838736-1-liuyacan@corp.netease.com>

On Tue, Aug 30, 2022 at 11:23:14PM +0800, liuyacan@corp.netease.com wrote:
> From: Yacan Liu <liuyacan@corp.netease.com>
> 
> For passive connections, the refcount increment has been done in
> smc_clcsock_accept()-->smc_sock_alloc().
> 
> Fixes: 3b2dec2603d5 ("net/smc: restructure client and server code in af_smc")
> Signed-off-by: Yacan Liu <liuyacan@corp.netease.com>
> 
> ---
> Change in v2:
>   -- Tune commit message
> ---
>  net/smc/af_smc.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
> index 79c1318af..0939cc3b9 100644
> --- a/net/smc/af_smc.c
> +++ b/net/smc/af_smc.c
> @@ -1855,7 +1855,6 @@ static void smc_listen_out_connected(struct smc_sock *new_smc)
>  {
>  	struct sock *newsmcsk = &new_smc->sk;
>  
> -	sk_refcnt_debug_inc(newsmcsk);
>  	if (newsmcsk->sk_state == SMC_INIT)
>  		newsmcsk->sk_state = SMC_ACTIVE;
>  

Thanks for this fixes. I dig into this sk_refcnt_debug_* facility. It
seems this is a very old debug methods and doesn't help a lot for sock
leak issue. Maybe there is another method to help track this issue?

For this patch, It looks good for me and tested in our environment.

Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>

Cheers,
Tony Lu