From 9ba33339c043addc4aee241fd7ac37593f7c9e7e Mon Sep 17 00:00:00 2001 From: Roi Dayan Date: Mon, 25 Jan 2021 11:28:07 +0200 Subject: net/mlx5e: Avoid false lock depenency warning on tc_ht To avoid false lock dependency warning set the tc_ht lock class different than the lock class of the ht being used when deleting last flow from a group and then deleting a group, we get into del_sw_flow_group() which call rhashtable_destroy on fg->ftes_hash which will take ht->mutex but it's different than the ht->mutex here. ====================================================== WARNING: possible circular locking dependency detected 5.11.0-rc4_net_next_mlx5_949fdcc #1 Not tainted ------------------------------------------------------ modprobe/12950 is trying to acquire lock: ffff88816510f910 (&node->lock){++++}-{3:3}, at: mlx5_del_flow_rules+0x2a/0x210 [mlx5_core] but task is already holding lock: ffff88815834e3e8 (&ht->mutex){+.+.}-{3:3}, at: rhashtable_free_and_destroy+0x37/0x340 which lock already depends on the new lock. Signed-off-by: Roi Dayan Signed-off-by: Saeed Mahameed --- drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'drivers/net') diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c index 8fd38ad8113b..280ea1e1e039 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c @@ -190,6 +190,14 @@ struct mlx5e_tc_attr_to_reg_mapping mlx5e_tc_attr_to_reg_mappings[] = { [NIC_ZONE_RESTORE_TO_REG] = nic_zone_restore_to_reg_ct, }; +/* To avoid false lock dependency warning set the tc_ht lock + * class different than the lock class of the ht being used when deleting + * last flow from a group and then deleting a group, we get into del_sw_flow_group() + * which call rhashtable_destroy on fg->ftes_hash which will take ht->mutex but + * it's different than the ht->mutex here. + */ +static struct lock_class_key tc_ht_lock_key; + static void mlx5e_put_flow_tunnel_id(struct mlx5e_tc_flow *flow); void @@ -5215,6 +5223,8 @@ int mlx5e_tc_nic_init(struct mlx5e_priv *priv) if (err) return err; + lockdep_set_class(&tc->ht.mutex, &tc_ht_lock_key); + if (MLX5_CAP_FLOWTABLE_NIC_RX(priv->mdev, ignore_flow_level)) { attr.flags = MLX5_CHAINS_AND_PRIOS_SUPPORTED | MLX5_CHAINS_IGNORE_FLOW_LEVEL_SUPPORTED; @@ -5333,6 +5343,8 @@ int mlx5e_tc_esw_init(struct rhashtable *tc_ht) if (err) goto err_ht_init; + lockdep_set_class(&tc_ht->mutex, &tc_ht_lock_key); + return err; err_ht_init: -- cgit v1.2.3