ksmbd: detect RDMA capable netdevs include IPoIB

Current ksmbd_rdma_capable_netdev fails to mark certain RDMA-capable
inerfaces such as IPoIB as RDMA capable after reverting GUID matching code
due to layer violation.
This patch check the ARPHRD_INFINIBAND type safely identifies an IPoIB
interface without introducing a layer violation, ensuring RDMA
functionality is correctly enabled for these interfaces.

Signed-off-by: Namjae Jeon <[email protected]>
Signed-off-by: Steve French <[email protected]>

Author: namjaejeon

fs/smb/server/transport_rdma.c

@@ -2663,6 +2663,10 @@ bool ksmbd_rdma_capable_netdev(struct net_device *netdev)
 			if (ksmbd_find_rdma_capable_netdev(lower_dev))
 				return true;
 
+	/* check if netdev is IPoIB safely without layer violation */
+	if (netdev->type == ARPHRD_INFINIBAND)
+		return true;
+
 	return false;
 }