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RDMA/mlx5: Annotate lock dependency in bind/unbind slave port

PATCH Applied Leon Romanovsky 2 participants 2 messages Aug 13, 2019

Subsystems (2)
InfiniBand Mellanox MLX5 IB driver
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Leon Romanovsky

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#0 lore raw

PATCH 1/1 RDMA/mlx5: Annotate lock dependency in bind/unbind slave port

From: Leon Romanovsky <[email protected]>

NULL-ing notifier_call is performed under protection of mlx5_ib_multiport_mutex lock. Such protection is not easily spotted and better to be guarded by lockdep annotation.

Signed-off-by Leon Romanovsky <[email protected]>

---
Changelog v1:
* Removed comments as we added lockdep annotations
* Added lockdep to bind port flow too
* https://lore.kernel.org/linux-rdma/[email protected]

---
 drivers/infiniband/hw/mlx5/main.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
drivers/infiniband/hw/mlx5/main.c +4 -2
index 7933534be931..e3a57646ddd3 100644
@@ -5825,7 +5825,6 @@ static void init_delay_drop(struct mlx5_ib_dev *dev)
 		mlx5_ib_warn(dev, "Failed to init delay drop debugfs\n");
 }
 
-/* The mlx5_ib_multiport_mutex should be held when calling this function */
 static void mlx5_ib_unbind_slave_port(struct mlx5_ib_dev *ibdev,
 				      struct mlx5_ib_multiport_info *mpi)
 {

@@ -5835,6 +5834,8 @@ static void mlx5_ib_unbind_slave_port(struct mlx5_ib_dev *ibdev,
 	int err;
 	int i;
 
+	lockdep_assert_held(&mlx5_ib_multiport_mutex);
+
 	mlx5_ib_cleanup_cong_debugfs(ibdev, port_num);
 
 	spin_lock(&port->mp.mpi_lock);

@@ -5884,13 +5885,14 @@ static void mlx5_ib_unbind_slave_port(struct mlx5_ib_dev *ibdev,
 	ibdev->port[port_num].roce.last_port_state = IB_PORT_DOWN;
 }
 
-/* The mlx5_ib_multiport_mutex should be held when calling this function */
 static bool mlx5_ib_bind_slave_port(struct mlx5_ib_dev *ibdev,
 				    struct mlx5_ib_multiport_info *mpi)
 {
 	u8 port_num = mlx5_core_native_port_num(mpi->mdev) - 1;
 	int err;
 
+	lockdep_assert_held(&mlx5_ib_multiport_mutex);
+
 	spin_lock(&ibdev->port[port_num].mp.mpi_lock);
 	if (ibdev->port[port_num].mp.mpi) {
 		mlx5_ib_dbg(ibdev, "port %d already affiliated.\n",

--
2.20.1

Applied
#1 lore raw
Quoted 8 lines · Leon Romanovsky

From: Leon Romanovsky <[email protected]>

NULL-ing notifier_call is performed under protection of mlx5_ib_multiport_mutex lock. Such protection is not easily spotted and better to be guarded by lockdep annotation.

Signed-off-by Leon Romanovsky <[email protected]>

Thanks, applied to for-next.

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