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From: Saeed Mahameed <saeedm@mellanox.com>
To: "David S. Miller" <davem@davemloft.net>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	Vlad Buslov <vladbu@mellanox.com>,
	Jianbo Liu <jianbol@mellanox.com>, Roi Dayan <roid@mellanox.com>,
	Saeed Mahameed <saeedm@mellanox.com>
Subject: [net-next 12/13] net/mlx5e: Rely on rcu instead of rtnl lock when getting upper dev
Date: Mon, 29 Jul 2019 23:50:34 +0000	[thread overview]
Message-ID: <20190729234934.23595-13-saeedm@mellanox.com> (raw)
In-Reply-To: <20190729234934.23595-1-saeedm@mellanox.com>

From: Vlad Buslov <vladbu@mellanox.com>

Function netdev_master_upper_dev_get() generates warning if caller doesn't
hold rtnl lock. Modify rules update path to use rcu version of that
function.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Reviewed-by: Jianbo Liu <jianbol@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
---
 .../net/ethernet/mellanox/mlx5/core/en/tc_tun.c    | 14 +++++++++++++-
 drivers/net/ethernet/mellanox/mlx5/core/en_tc.c    |  6 +++++-
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c
index ae439d95f5a3..4c4620db3d31 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c
@@ -31,11 +31,23 @@ static int get_route_and_out_devs(struct mlx5e_priv *priv,
 
 	real_dev = is_vlan_dev(dev) ? vlan_dev_real_dev(dev) : dev;
 	uplink_dev = mlx5_eswitch_uplink_get_proto_dev(esw, REP_ETH);
-	uplink_upper = netdev_master_upper_dev_get(uplink_dev);
+
+	rcu_read_lock();
+	uplink_upper = netdev_master_upper_dev_get_rcu(uplink_dev);
+	/* mlx5_lag_is_sriov() is a blocking function which can't be called
+	 * while holding rcu read lock. Take the net_device for correctness
+	 * sake.
+	 */
+	if (uplink_upper)
+		dev_hold(uplink_upper);
+	rcu_read_unlock();
+
 	dst_is_lag_dev = (uplink_upper &&
 			  netif_is_lag_master(uplink_upper) &&
 			  real_dev == uplink_upper &&
 			  mlx5_lag_is_sriov(priv->mdev));
+	if (uplink_upper)
+		dev_put(uplink_upper);
 
 	/* if the egress device isn't on the same HW e-switch or
 	 * it's a LAG device, use the uplink
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index 714aa9d7180b..595a4c5667ea 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -2978,12 +2978,16 @@ static int parse_tc_fdb_actions(struct mlx5e_priv *priv,
 			if (netdev_port_same_parent_id(priv->netdev, out_dev)) {
 				struct mlx5_eswitch *esw = priv->mdev->priv.eswitch;
 				struct net_device *uplink_dev = mlx5_eswitch_uplink_get_proto_dev(esw, REP_ETH);
-				struct net_device *uplink_upper = netdev_master_upper_dev_get(uplink_dev);
+				struct net_device *uplink_upper;
 
+				rcu_read_lock();
+				uplink_upper =
+					netdev_master_upper_dev_get_rcu(uplink_dev);
 				if (uplink_upper &&
 				    netif_is_lag_master(uplink_upper) &&
 				    uplink_upper == out_dev)
 					out_dev = uplink_dev;
+				rcu_read_unlock();
 
 				if (is_vlan_dev(out_dev)) {
 					err = add_vlan_push_action(priv, attr,
-- 
2.21.0


  parent reply	other threads:[~2019-07-29 23:52 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-29 23:50 [pull request][net-next 00/13] Mellanox, mlx5 tc flow handling for concurrent execution (Part 1) Saeed Mahameed
2019-07-29 23:50 ` [net-next 01/13] net/mlx5e: Print a warning when LRO feature is dropped or not allowed Saeed Mahameed
2019-07-30 15:52   ` Willem de Bruijn
2019-07-30 20:07     ` Saeed Mahameed
2019-07-30 21:34       ` Willem de Bruijn
2019-07-29 23:50 ` [net-next 02/13] net/mlx5e: Avoid warning print when not required Saeed Mahameed
2019-07-29 23:50 ` [net-next 03/13] net/mlx5e: Improve ethtool rxnfc callback structure Saeed Mahameed
2019-07-29 23:50 ` [net-next 04/13] net/mlx5e: Fix unnecessary flow_block_cb_is_busy call Saeed Mahameed
2019-07-29 23:50 ` [net-next 05/13] net/mlx5e: Simplify get_route_and_out_devs helper function Saeed Mahameed
2019-07-29 23:50 ` [net-next 06/13] net/mlx5e: Extend tc flow struct with reference counter Saeed Mahameed
2019-07-29 23:50 ` [net-next 07/13] net/mlx5e: Change flow flags type to unsigned long Saeed Mahameed
2019-07-29 23:50 ` [net-next 08/13] net/mlx5e: Protect tc flows hashtable with rcu Saeed Mahameed
2019-07-30 16:15   ` Willem de Bruijn
2019-07-30 16:37     ` Willem de Bruijn
2019-07-30 20:09       ` Saeed Mahameed
2019-07-29 23:50 ` [net-next 09/13] net/mlx5e: Protect unready flows with dedicated lock Saeed Mahameed
2019-07-29 23:50 ` [net-next 10/13] net/mlx5e: Eswitch, change offloads num_flows type to atomic64 Saeed Mahameed
2019-07-29 23:50 ` [net-next 11/13] net/mlx5e: Eswitch, use state_lock to synchronize vlan change Saeed Mahameed
2019-07-29 23:50 ` Saeed Mahameed [this message]
2019-07-29 23:50 ` [net-next 13/13] net/mlx5e: Protect tc flow table with mutex Saeed Mahameed
2019-07-31 22:48 ` [pull request][net-next 00/13] Mellanox, mlx5 tc flow handling for concurrent execution (Part 1) David Miller

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