Re: [PATCH net] net/smc: use the correct ndev to find pnetid by pnetid table

[Wen Gu <guwen@linux.alibaba.com>]

On 2024/12/27 12:04, Guangguan Wang wrote:
> The command 'smc_pnet -a -I <ethx> <pnetid>' will add <pnetid>
> to the pnetid table and will attach the <pnetid> to net device
> whose name is <ethx>. But When do SMCR by <ethx>, in function
> smc_pnet_find_roce_by_pnetid, it will use <ethx>'s base ndev's
> pnetid to match rdma device, not <ethx>'s pnetid. The asymmetric
> use of the pnetid seems weird. Sometimes it is difficult to know
> the hierarchy of net device what may make it difficult to configure
> the pnetid and to use the pnetid. Looking into the history of
> commit, it was the commit 890a2cb4a966 ("net/smc: rework pnet table")
> that changes the ndev from the <ethx> to the <ethx>'s base ndev
> when finding pnetid by pnetid table. It seems a mistake.
> 
> This patch changes the ndev back to the <ethx> when finding pnetid
> by pnetid table.
> 
> Fixes: 890a2cb4a966 ("net/smc: rework pnet table")
> Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>

It makes sense to me, thanks!

Reviewed-by: Wen Gu <guwen@linux.alibaba.com>

> ---
>   net/smc/smc_pnet.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/net/smc/smc_pnet.c b/net/smc/smc_pnet.c
> index 716808f374a8..cc098780970b 100644
> --- a/net/smc/smc_pnet.c
> +++ b/net/smc/smc_pnet.c
> @@ -1079,14 +1079,15 @@ static void smc_pnet_find_roce_by_pnetid(struct net_device *ndev,
>   					 struct smc_init_info *ini)
>   {
>   	u8 ndev_pnetid[SMC_MAX_PNETID_LEN];
> +	struct net_device *base_ndev;
>   	struct net *net;
>   
> -	ndev = pnet_find_base_ndev(ndev);
> +	base_ndev = pnet_find_base_ndev(ndev);
>   	net = dev_net(ndev);
> -	if (smc_pnetid_by_dev_port(ndev->dev.parent, ndev->dev_port,
> +	if (smc_pnetid_by_dev_port(base_ndev->dev.parent, base_ndev->dev_port,
>   				   ndev_pnetid) &&
>   	    smc_pnet_find_ndev_pnetid_by_table(ndev, ndev_pnetid)) {
> -		smc_pnet_find_rdma_dev(ndev, ini);
> +		smc_pnet_find_rdma_dev(base_ndev, ini);
>   		return; /* pnetid could not be determined */
>   	}
>   	_smc_pnet_find_roce_by_pnetid(ndev_pnetid, ini, NULL, net);