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Commit c3f9bf62 authored by Maor Gottlieb's avatar Maor Gottlieb Committed by David S. Miller
Browse files

net/mlx5_core: Fix soft lockup in steering error flow 



In the error flow of adding flow rule to auto-grouped flow
table, we call to tree_remove_node.

tree_remove_node locks the node's parent, however the node's parent
is already locked by mlx5_add_flow_rule and this causes a deadlock.
After this patch, if we failed to add the flow rule, we unlock the
flow table before calling to tree_remove_node.

fixes: f0d22d18 ('net/mlx5_core: Introduce flow steering autogrouped
flow table')
Signed-off-by: default avatarMaor Gottlieb <maorg@mellanox.com>
Reported-by: default avatarAmir Vadai <amir@vadai.me>
Signed-off-by: default avatarSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 45c78e02

drivers/net/ethernet/mellanox/mlx5/core/fs_core.c

+17 −29
Original line number Original line Diff line number Diff line
@@ -1065,33 +1065,6 @@ static struct mlx5_flow_rule *add_rule_fg(struct mlx5_flow_group *fg, 
	return rule;

	return rule;

}

}





static struct mlx5_flow_rule *add_rule_to_auto_fg(struct mlx5_flow_table *ft,

						  u8 match_criteria_enable,

						  u32 *match_criteria,

						  u32 *match_value,

						  u8 action,

						  u32 flow_tag,

						  struct mlx5_flow_destination *dest)

{

	struct mlx5_flow_rule *rule;

	struct mlx5_flow_group *g;



	g = create_autogroup(ft, match_criteria_enable, match_criteria);

	if (IS_ERR(g))

		return (void *)g;



	rule = add_rule_fg(g, match_value,

			   action, flow_tag, dest);

	if (IS_ERR(rule)) {

		/* Remove assumes refcount > 0 and autogroup creates a group

		 * with a refcount = 0.

		 */

		tree_get_node(&g->node);

		tree_remove_node(&g->node);

	}

	return rule;

}



static struct mlx5_flow_rule *

static struct mlx5_flow_rule *

_mlx5_add_flow_rule(struct mlx5_flow_table *ft,

_mlx5_add_flow_rule(struct mlx5_flow_table *ft,

		    u8 match_criteria_enable,

		    u8 match_criteria_enable,
@@ -1119,8 +1092,23 @@ _mlx5_add_flow_rule(struct mlx5_flow_table *ft, 
				goto unlock;

				goto unlock;

		}

		}





	rule = add_rule_to_auto_fg(ft, match_criteria_enable, match_criteria,

	g = create_autogroup(ft, match_criteria_enable, match_criteria);

				   match_value, action, flow_tag, dest);

	if (IS_ERR(g)) {

		rule = (void *)g;

		goto unlock;

	}



	rule = add_rule_fg(g, match_value,

			   action, flow_tag, dest);

	if (IS_ERR(rule)) {

		/* Remove assumes refcount > 0 and autogroup creates a group

		 * with a refcount = 0.

		 */

		unlock_ref_node(&ft->node);

		tree_get_node(&g->node);

		tree_remove_node(&g->node);

		return rule;

	}

unlock:

unlock:

	unlock_ref_node(&ft->node);

	unlock_ref_node(&ft->node);

	return rule;

	return rule;