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

[Anumula Murali Mohan Reddy <anumula@chelsio.com>]

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;
 
 	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);
-- 
2.39.3