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author | Jiri Pirko <jiri@nvidia.com> | 2022-11-01 15:36:01 +0100 |
---|---|---|
committer | Saeed Mahameed <saeedm@nvidia.com> | 2023-02-08 20:40:57 -0800 |
commit | dca55da0a15717dde509d17163946e951bad56c4 (patch) | |
tree | 2ca0c18b8531afaaa229ec7237506fa3d5afc674 /drivers/infiniband/hw/mlx5/main.c | |
parent | c7d4e6ab3165693342c21f6faf80d983137fee0c (diff) | |
download | linux-stable-dca55da0a15717dde509d17163946e951bad56c4.tar.gz linux-stable-dca55da0a15717dde509d17163946e951bad56c4.tar.bz2 linux-stable-dca55da0a15717dde509d17163946e951bad56c4.zip |
RDMA/mlx5: Track netdev to avoid deadlock during netdev notifier unregister
When removing a network namespace with mlx5 devlink instance being in
it, following callchain is performed:
cleanup_net (takes down_read(&pernet_ops_rwsem)
devlink_pernet_pre_exit()
devlink_reload()
mlx5_devlink_reload_down()
mlx5_unload_one_devl_locked()
mlx5_detach_device()
del_adev()
mlx5r_remove()
__mlx5_ib_remove()
mlx5_ib_roce_cleanup()
mlx5_remove_netdev_notifier()
unregister_netdevice_notifier (takes down_write(&pernet_ops_rwsem)
This deadlocks.
Resolve this by converting to register_netdevice_notifier_dev_net()
which does not take pernet_ops_rwsem and moves the notifier block around
according to netdev it takes as arg.
Use previously introduced netdev added/removed events to track uplink
netdev to be used for register_netdevice_notifier_dev_net() purposes.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Diffstat (limited to 'drivers/infiniband/hw/mlx5/main.c')
-rw-r--r-- | drivers/infiniband/hw/mlx5/main.c | 78 |
1 files changed, 54 insertions, 24 deletions
diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c index c669ef6e47e7..dc32e4518a28 100644 --- a/drivers/infiniband/hw/mlx5/main.c +++ b/drivers/infiniband/hw/mlx5/main.c @@ -3012,26 +3012,63 @@ static void mlx5_eth_lag_cleanup(struct mlx5_ib_dev *dev) } } -static int mlx5_add_netdev_notifier(struct mlx5_ib_dev *dev, u32 port_num) +static void mlx5_netdev_notifier_register(struct mlx5_roce *roce, + struct net_device *netdev) { int err; - dev->port[port_num].roce.nb.notifier_call = mlx5_netdev_event; - err = register_netdevice_notifier(&dev->port[port_num].roce.nb); - if (err) { - dev->port[port_num].roce.nb.notifier_call = NULL; - return err; - } + if (roce->tracking_netdev) + return; + roce->tracking_netdev = netdev; + roce->nb.notifier_call = mlx5_netdev_event; + err = register_netdevice_notifier_dev_net(netdev, &roce->nb, &roce->nn); + WARN_ON(err); +} - return 0; +static void mlx5_netdev_notifier_unregister(struct mlx5_roce *roce) +{ + if (!roce->tracking_netdev) + return; + unregister_netdevice_notifier_dev_net(roce->tracking_netdev, &roce->nb, + &roce->nn); + roce->tracking_netdev = NULL; } -static void mlx5_remove_netdev_notifier(struct mlx5_ib_dev *dev, u32 port_num) +static int mlx5e_mdev_notifier_event(struct notifier_block *nb, + unsigned long event, void *data) { - if (dev->port[port_num].roce.nb.notifier_call) { - unregister_netdevice_notifier(&dev->port[port_num].roce.nb); - dev->port[port_num].roce.nb.notifier_call = NULL; + struct mlx5_roce *roce = container_of(nb, struct mlx5_roce, mdev_nb); + struct net_device *netdev = data; + + switch (event) { + case MLX5_DRIVER_EVENT_UPLINK_NETDEV: + if (netdev) + mlx5_netdev_notifier_register(roce, netdev); + else + mlx5_netdev_notifier_unregister(roce); + break; + default: + return NOTIFY_DONE; } + + return NOTIFY_OK; +} + +static void mlx5_mdev_netdev_track(struct mlx5_ib_dev *dev, u32 port_num) +{ + struct mlx5_roce *roce = &dev->port[port_num].roce; + + roce->mdev_nb.notifier_call = mlx5e_mdev_notifier_event; + mlx5_blocking_notifier_register(dev->mdev, &roce->mdev_nb); + mlx5_core_uplink_netdev_event_replay(dev->mdev); +} + +static void mlx5_mdev_netdev_untrack(struct mlx5_ib_dev *dev, u32 port_num) +{ + struct mlx5_roce *roce = &dev->port[port_num].roce; + + mlx5_blocking_notifier_unregister(dev->mdev, &roce->mdev_nb); + mlx5_netdev_notifier_unregister(roce); } static int mlx5_enable_eth(struct mlx5_ib_dev *dev) @@ -3138,7 +3175,7 @@ static void mlx5_ib_unbind_slave_port(struct mlx5_ib_dev *ibdev, if (mpi->mdev_events.notifier_call) mlx5_notifier_unregister(mpi->mdev, &mpi->mdev_events); mpi->mdev_events.notifier_call = NULL; - mlx5_remove_netdev_notifier(ibdev, port_num); + mlx5_mdev_netdev_untrack(ibdev, port_num); spin_lock(&port->mp.mpi_lock); comps = mpi->mdev_refcnt; @@ -3196,12 +3233,7 @@ static bool mlx5_ib_bind_slave_port(struct mlx5_ib_dev *ibdev, if (err) goto unbind; - err = mlx5_add_netdev_notifier(ibdev, port_num); - if (err) { - mlx5_ib_err(ibdev, "failed adding netdev notifier for port %u\n", - port_num + 1); - goto unbind; - } + mlx5_mdev_netdev_track(ibdev, port_num); mpi->mdev_events.notifier_call = mlx5_ib_event_slave_port; mlx5_notifier_register(mpi->mdev, &mpi->mdev_events); @@ -3909,9 +3941,7 @@ static int mlx5_ib_roce_init(struct mlx5_ib_dev *dev) port_num = mlx5_core_native_port_num(dev->mdev) - 1; /* Register only for native ports */ - err = mlx5_add_netdev_notifier(dev, port_num); - if (err) - return err; + mlx5_mdev_netdev_track(dev, port_num); err = mlx5_enable_eth(dev); if (err) @@ -3920,7 +3950,7 @@ static int mlx5_ib_roce_init(struct mlx5_ib_dev *dev) return 0; cleanup: - mlx5_remove_netdev_notifier(dev, port_num); + mlx5_mdev_netdev_untrack(dev, port_num); return err; } @@ -3938,7 +3968,7 @@ static void mlx5_ib_roce_cleanup(struct mlx5_ib_dev *dev) mlx5_disable_eth(dev); port_num = mlx5_core_native_port_num(dev->mdev) - 1; - mlx5_remove_netdev_notifier(dev, port_num); + mlx5_mdev_netdev_untrack(dev, port_num); } } |