ksmbd: fix missing RDMA-capable flag for IPoIB device in ksmbd_rdma_capable_netdev()

Physical ib_device does not have an underlying net_device, thus its
association with IPoIB net_device cannot be retrieved via
ops.get_netdev() or ib_device_get_by_netdev(). ksmbd reads physical
ib_device port GUID from the lower 16 bytes of the hardware addresses on
IPoIB net_device and match its underlying ib_device using ib_find_gid()
Signed-off-by: Kangjing Huang <huangkangjing@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Reviewed-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/smb/server/transport_rdma.c

@@ -2140,8 +2140,7 @@ static int smb_direct_ib_client_add(struct ib_device *ib_dev)
 	if (ib_dev->node_type != RDMA_NODE_IB_CA)
 		smb_direct_port = SMB_DIRECT_PORT_IWARP;
 
-	if (!ib_dev->ops.get_netdev ||
-	    !rdma_frwr_is_supported(&ib_dev->attrs))
+	if (!rdma_frwr_is_supported(&ib_dev->attrs))
 		return 0;
 
 	smb_dev = kzalloc(sizeof(*smb_dev), GFP_KERNEL);
@@ -2241,17 +2240,38 @@ bool ksmbd_rdma_capable_netdev(struct net_device *netdev)
 		for (i = 0; i < smb_dev->ib_dev->phys_port_cnt; i++) {
 			struct net_device *ndev;
 
-			ndev = smb_dev->ib_dev->ops.get_netdev(smb_dev->ib_dev,
-							       i + 1);
-			if (!ndev)
-				continue;
+			if (smb_dev->ib_dev->ops.get_netdev) {
+				ndev = smb_dev->ib_dev->ops.get_netdev(
+					smb_dev->ib_dev, i + 1);
+				if (!ndev)
+					continue;
 
-			if (ndev == netdev) {
+				if (ndev == netdev) {
+					dev_put(ndev);
+					rdma_capable = true;
+					goto out;
+				}
 				dev_put(ndev);
-				rdma_capable = true;
-				goto out;
+			/* if ib_dev does not implement ops.get_netdev
+			 * check for matching infiniband GUID in hw_addr
+			 */
+			} else if (netdev->type == ARPHRD_INFINIBAND) {
+				struct netdev_hw_addr *ha;
+				union ib_gid gid;
+				u32 port_num;
+				int ret;
+
+				netdev_hw_addr_list_for_each(
+					ha, &netdev->dev_addrs) {
+					memcpy(&gid, ha->addr + 4, sizeof(gid));
+					ret = ib_find_gid(smb_dev->ib_dev, &gid,
+							  &port_num, NULL);
+					if (!ret) {
+						rdma_capable = true;
+						goto out;
+					}
+				}
 			}
-			dev_put(ndev);
 		}
 	}
 out: