Re: [PATCH for-rc] RDMA/core: Fix ENODEV error for iWARP test over vlan

[Zhu Yanjun <yanjun.zhu@linux.dev>]

在 2024/11/19 7:18, Anumula Murali Mohan Reddy 写道:
> If traffic is over vlan, cma_validate_port() fails to match
> net_device ifindex with bound_if_index and results in ENODEV error.
> As iWARP gid table is static, it contains entry corresponding  to
> only one net device which is either real netdev or vlan netdev for
> cases like  siw attached to a vlan interface.
> This patch fixes the issue by assigning bound_if_index with net
> device index, if real net device obtained from bound if index matches
> with net device retrieved from gid table
> 
> Fixes: f8ef1be816bf ("RDMA/cma: Avoid GID lookups on iWARP devices")
> Link: https://lore.kernel.org/all/ZzNgdrjo1kSCGbRz@chelsio.com/
> Signed-off-by: Anumula Murali Mohan Reddy <anumula@chelsio.com>
> Signed-off-by: Potnuri Bharat Teja <bharat@chelsio.com>
> ---
>   drivers/infiniband/core/cma.c | 17 ++++++++++++++++-
>   1 file changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
> index 64ace0b968f0..97657e1810d8 100644
> --- a/drivers/infiniband/core/cma.c
> +++ b/drivers/infiniband/core/cma.c
> @@ -689,7 +689,7 @@ cma_validate_port(struct ib_device *device, u32 port,
>   	const struct ib_gid_attr *sgid_attr = ERR_PTR(-ENODEV);
>   	int bound_if_index = dev_addr->bound_dev_if;
>   	int dev_type = dev_addr->dev_type;
> -	struct net_device *ndev = NULL;
> +	struct net_device *ndev = NULL, *pdev = NULL;

In the original source code, the local variables lay out in the form of 
Reverse Christmas Tree.
But the new code breaks the rule of Reverse Christmas Tree.

Zhu Yanjun

>   
>   	if (!rdma_dev_access_netns(device, id_priv->id.route.addr.dev_addr.net))
>   		goto out;
> @@ -714,6 +714,21 @@ cma_validate_port(struct ib_device *device, u32 port,
>   
>   		rcu_read_lock();
>   		ndev = rcu_dereference(sgid_attr->ndev);
> +		if (ndev->ifindex != bound_if_index) {
> +			pdev = dev_get_by_index_rcu(dev_addr->net, bound_if_index);
> +			if (pdev) {
> +				if (is_vlan_dev(pdev)) {
> +					pdev = vlan_dev_real_dev(pdev);
> +					if (ndev->ifindex == pdev->ifindex)
> +						bound_if_index = pdev->ifindex;
> +				}
> +				if (is_vlan_dev(ndev)) {
> +					pdev = vlan_dev_real_dev(ndev);
> +					if (bound_if_index == pdev->ifindex)
> +						bound_if_index = ndev->ifindex;
> +				}
> +			}
> +		}
>   		if (!net_eq(dev_net(ndev), dev_addr->net) ||
>   		    ndev->ifindex != bound_if_index) {
>   			rdma_put_gid_attr(sgid_attr);