From c3f9bf628bc7edda298897d952f5e761137229c9 Mon Sep 17 00:00:00 2001 From: Maor Gottlieb Date: Fri, 22 Apr 2016 00:33:00 +0300 Subject: [PATCH] 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: f0d22d187473 ('net/mlx5_core: Introduce flow steering autogrouped flow table') Signed-off-by: Maor Gottlieb Reported-by: Amir Vadai Signed-off-by: Saeed Mahameed Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlx5/core/fs_core.c | 46 +++++++++-------------- 1 file changed, 17 insertions(+), 29 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c index 5121be4..3c7e3e5 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/fs_core.c @@ -1065,33 +1065,6 @@ unlock_fg: 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 * _mlx5_add_flow_rule(struct mlx5_flow_table *ft, u8 match_criteria_enable, @@ -1119,8 +1092,23 @@ _mlx5_add_flow_rule(struct mlx5_flow_table *ft, goto unlock; } - rule = add_rule_to_auto_fg(ft, match_criteria_enable, match_criteria, - match_value, action, flow_tag, dest); + g = create_autogroup(ft, match_criteria_enable, match_criteria); + 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_ref_node(&ft->node); return rule; -- 2.7.4