[PATCH 4.9 012/175] net/mlx4_en: Avoid scheduling restart task if it is already running

Greg Kroah-Hartman
2020-12-28T16:41:14Z

From: Moshe Shemesh <moshe@mellanox.com>

[ Upstream commit fed91613c9dd455dd154b22fa8e11b8526466082 ]

Add restarting state flag to avoid scheduling another restart task while
such task is already running. Change task name from watchdog_task to
restart_task to better fit the task role.

Fixes: 1e338db56e5a ("mlx4_en: Fix a race at restart task")
Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/mellanox/mlx4/en_netdev.c | 20 +++++++++++++-------
drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 7 ++++++-
2 files changed, 19 insertions(+), 8 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
@@ -1311,8 +1311,10 @@ static void mlx4_en_tx_timeout(struct ne
}

priv->port_stats.tx_timeout++;
- en_dbg(DRV, priv, "Scheduling watchdog\n");
- queue_work(mdev->workqueue, &priv->watchdog_task);
+ if (!test_and_set_bit(MLX4_EN_STATE_FLAG_RESTARTING, &priv->state)) {
+ en_dbg(DRV, priv, "Scheduling port restart\n");
+ queue_work(mdev->workqueue, &priv->restart_task);
+ }
}

@@ -1746,6 +1748,7 @@ int mlx4_en_start_port(struct net_device
local_bh_enable();
}

+ clear_bit(MLX4_EN_STATE_FLAG_RESTARTING, &priv->state);
netif_tx_start_all_queues(dev);
netif_device_attach(dev);

@@ -1900,7 +1903,7 @@ void mlx4_en_stop_port(struct net_device
static void mlx4_en_restart(struct work_struct *work)
{
struct mlx4_en_priv *priv = container_of(work, struct mlx4_en_priv,
- watchdog_task);
+ restart_task);
struct mlx4_en_dev *mdev = priv->mdev;
struct net_device *dev = priv->dev;

@@ -2220,7 +2223,7 @@ static int mlx4_en_change_mtu(struct net
if (netif_running(dev)) {
mutex_lock(&mdev->state_lock);
if (!mdev->device_up) {
- /* NIC is probably restarting - let watchdog task reset
+ /* NIC is probably restarting - let restart task reset
* the port */
en_dbg(DRV, priv, "Change MTU called with card down!?\n");
} else {
@@ -2229,7 +2232,9 @@ static int mlx4_en_change_mtu(struct net
if (err) {
en_err(priv, "Failed restarting port:%d\n",
priv->port);
- queue_work(mdev->workqueue, &priv->watchdog_task);
+ if (!test_and_set_bit(MLX4_EN_STATE_FLAG_RESTARTING,
+ &priv->state))
+ queue_work(mdev->workqueue, &priv->restart_task);
}
}
mutex_unlock(&mdev->state_lock);
@@ -2701,7 +2706,8 @@ static int mlx4_xdp_set(struct net_devic
if (err) {
en_err(priv, "Failed starting port %d for XDP change\n",
priv->port);
- queue_work(mdev->workqueue, &priv->watchdog_task);
+ if (!test_and_set_bit(MLX4_EN_STATE_FLAG_RESTARTING, &priv->state))
+ queue_work(mdev->workqueue, &priv->restart_task);
}
}

@@ -3080,7 +3086,7 @@ int mlx4_en_init_netdev(struct mlx4_en_d
priv->counter_index = MLX4_SINK_COUNTER_INDEX(mdev->dev);
spin_lock_init(&priv->stats_lock);
INIT_WORK(&priv->rx_mode_task, mlx4_en_do_set_rx_mode);
- INIT_WORK(&priv->watchdog_task, mlx4_en_restart);
+ INIT_WORK(&priv->restart_task, mlx4_en_restart);
INIT_WORK(&priv->linkstate_task, mlx4_en_linkstate);
INIT_DELAYED_WORK(&priv->stats_task, mlx4_en_do_get_stats);
INIT_DELAYED_WORK(&priv->service_task, mlx4_en_service_task);
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -522,6 +522,10 @@ struct mlx4_en_stats_bitmap {
struct mutex mutex; /* for mutual access to stats bitmap */
};

+enum {
+ MLX4_EN_STATE_FLAG_RESTARTING,
+};
+
struct mlx4_en_priv {
struct mlx4_en_dev *mdev;
struct mlx4_en_port_profile *prof;
@@ -586,7 +590,7 @@ struct mlx4_en_priv {
struct mlx4_en_cq *rx_cq[MAX_RX_RINGS];
struct mlx4_qp drop_qp;
struct work_struct rx_mode_task;
- struct work_struct watchdog_task;
+ struct work_struct restart_task;
struct work_struct linkstate_task;
struct delayed_work stats_task;
struct delayed_work service_task;
@@ -632,6 +636,7 @@ struct mlx4_en_priv {
u32 pflags;
u8 rss_key[MLX4_EN_RSS_KEY_SIZE];
u8 rss_hash_fn;
+ unsigned long state;
};

enum mlx4_en_wol {