IB/mlx5: Fix transport-domain rollback and initialize lb mutex earlier

[ Upstream commit e793891 ]

mlx5_ib_alloc_transport_domain() allocates a transport domain and then
may fail in mlx5_ib_enable_lb(). In that case, the allocated TD is leaked.

Fix this by deallocating the TD when mlx5_ib_enable_lb() returns an
error. Also return 0 explicitly in the no-loopback-capability success
branch, and move dev->lb.mutex initialization to mlx5_ib_stage_init_init().

Fixes: 146d2f1 ("IB/mlx5: Allocate a Transport Domain for each ucontext")
Signed-off-by: Prathamesh Deshpande <prathameshdeshpande7@gmail.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: prathameshdeshpande7

drivers/infiniband/hw/mlx5/main.c

@@ -1785,9 +1785,13 @@ static int mlx5_ib_alloc_transport_domain(struct mlx5_ib_dev *dev, u32 *tdn,
 	if ((MLX5_CAP_GEN(dev->mdev, port_type) != MLX5_CAP_PORT_TYPE_ETH) ||
 	    (!MLX5_CAP_GEN(dev->mdev, disable_local_lb_uc) &&
 	     !MLX5_CAP_GEN(dev->mdev, disable_local_lb_mc)))
-		return err;
+		return 0;
+
+	err = mlx5_ib_enable_lb(dev, true, false);
+	if (err)
+		mlx5_cmd_dealloc_transport_domain(dev->mdev, *tdn, uid);
 
-	return mlx5_ib_enable_lb(dev, true, false);
+	return err;
 }
 
 static void mlx5_ib_dealloc_transport_domain(struct mlx5_ib_dev *dev, u32 tdn,
@@ -3791,6 +3795,8 @@ static int mlx5_ib_stage_init_init(struct mlx5_ib_dev *dev)
 		dev->port[i].roce.last_port_state = IB_PORT_DOWN;
 	}
 
+	mutex_init(&dev->lb.mutex);
+
 	err = mlx5r_cmd_query_special_mkeys(dev);
 	if (err)
 		return err;
@@ -4006,11 +4012,6 @@ static int mlx5_ib_stage_caps_init(struct mlx5_ib_dev *dev)
 	if (err)
 		return err;
 
-	if ((MLX5_CAP_GEN(dev->mdev, port_type) == MLX5_CAP_PORT_TYPE_ETH) &&
-	    (MLX5_CAP_GEN(dev->mdev, disable_local_lb_uc) ||
-	     MLX5_CAP_GEN(dev->mdev, disable_local_lb_mc)))
-		mutex_init(&dev->lb.mutex);
-
 	if (MLX5_CAP_GEN_64(dev->mdev, general_obj_types) &
 			MLX5_GENERAL_OBJ_TYPES_CAP_VIRTIO_NET_Q) {
 		err = mlx5_ib_init_var_table(dev);