From 38789d72ea1a8009cd52229695b56e6749a775db Mon Sep 17 00:00:00 2001
From: Alaa Hleihel <ahleihel@redhat.com>
Date: Tue, 19 May 2020 07:49:10 -0400
Subject: [PATCH 248/312] [netdrv] net/mlx5e: CT: Use rhashtable's ct entries
 instead of a separate list

Message-id: <20200519074934.6303-40-ahleihel@redhat.com>
Patchwork-id: 310551
Patchwork-instance: patchwork
O-Subject: [RHEL8.3 BZ 1663246 39/63] net/mlx5e: CT: Use rhashtable's ct entries instead of a separate list
Bugzilla: 1663246
RH-Acked-by: Marcelo Leitner <mleitner@redhat.com>
RH-Acked-by: Jarod Wilson <jarod@redhat.com>
RH-Acked-by: John Linville <linville@redhat.com>
RH-Acked-by: Ivan Vecera <ivecera@redhat.com>
RH-Acked-by: Tony Camuso <tcamuso@redhat.com>
RH-Acked-by: Kamal Heib <kheib@redhat.com>

Bugzilla: http://bugzilla.redhat.com/1663246
Upstream: v5.7-rc2

commit 9808dd0a2aeebcb72239a3b082159b0186d9ac3d
Author: Paul Blakey <paulb@mellanox.com>
Date:   Fri Mar 27 12:12:31 2020 +0300

    net/mlx5e: CT: Use rhashtable's ct entries instead of a separate list

    Fixes CT entries list corruption.

    After allowing parallel insertion/removals in upper nf flow table
    layer, unprotected ct entries list can be corrupted by parallel add/del
    on the same flow table.

    CT entries list is only used while freeing a ct zone flow table to
    go over all the ct entries offloaded on that zone/table, and flush
    the table.

    As rhashtable already provides an api to go over all the inserted entries,
    fix the race by using the rhashtable iteration instead, and remove the list.

    Fixes: 7da182a998d6 ("netfilter: flowtable: Use work entry per offload command")
    Reviewed-by: Oz Shlomo <ozsh@mellanox.com>
    Signed-off-by: Paul Blakey <paulb@mellanox.com>
    Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

Signed-off-by: Alaa Hleihel <ahleihel@redhat.com>
Signed-off-by: Frantisek Hrbata <fhrbata@redhat.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c
index cb43b53bc235..14b29d0d5092 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_ct.c
@@ -67,11 +67,9 @@ struct mlx5_ct_ft {
 	struct nf_flowtable *nf_ft;
 	struct mlx5_tc_ct_priv *ct_priv;
 	struct rhashtable ct_entries_ht;
-	struct list_head ct_entries_list;
 };
 
 struct mlx5_ct_entry {
-	struct list_head list;
 	u16 zone;
 	struct rhash_head node;
 	struct flow_rule *flow_rule;
@@ -617,8 +615,6 @@ mlx5_tc_ct_block_flow_offload_add(struct mlx5_ct_ft *ft,
 	if (err)
 		goto err_insert;
 
-	list_add(&entry->list, &ft->ct_entries_list);
-
 	return 0;
 
 err_insert:
@@ -646,7 +642,6 @@ mlx5_tc_ct_block_flow_offload_del(struct mlx5_ct_ft *ft,
 	WARN_ON(rhashtable_remove_fast(&ft->ct_entries_ht,
 				       &entry->node,
 				       cts_ht_params));
-	list_del(&entry->list);
 	kfree(entry);
 
 	return 0;
@@ -818,7 +813,6 @@ mlx5_tc_ct_add_ft_cb(struct mlx5_tc_ct_priv *ct_priv, u16 zone,
 	ft->zone = zone;
 	ft->nf_ft = nf_ft;
 	ft->ct_priv = ct_priv;
-	INIT_LIST_HEAD(&ft->ct_entries_list);
 	refcount_set(&ft->refcount, 1);
 
 	err = rhashtable_init(&ft->ct_entries_ht, &cts_ht_params);
@@ -847,12 +841,12 @@ mlx5_tc_ct_add_ft_cb(struct mlx5_tc_ct_priv *ct_priv, u16 zone,
 }
 
 static void
-mlx5_tc_ct_flush_ft(struct mlx5_tc_ct_priv *ct_priv, struct mlx5_ct_ft *ft)
+mlx5_tc_ct_flush_ft_entry(void *ptr, void *arg)
 {
-	struct mlx5_ct_entry *entry;
+	struct mlx5_tc_ct_priv *ct_priv = arg;
+	struct mlx5_ct_entry *entry = ptr;
 
-	list_for_each_entry(entry, &ft->ct_entries_list, list)
-		mlx5_tc_ct_entry_del_rules(ft->ct_priv, entry);
+	mlx5_tc_ct_entry_del_rules(ct_priv, entry);
 }
 
 static void
@@ -863,9 +857,10 @@ mlx5_tc_ct_del_ft_cb(struct mlx5_tc_ct_priv *ct_priv, struct mlx5_ct_ft *ft)
 
 	nf_flow_table_offload_del_cb(ft->nf_ft,
 				     mlx5_tc_ct_block_flow_offload, ft);
-	mlx5_tc_ct_flush_ft(ct_priv, ft);
 	rhashtable_remove_fast(&ct_priv->zone_ht, &ft->node, zone_params);
-	rhashtable_destroy(&ft->ct_entries_ht);
+	rhashtable_free_and_destroy(&ft->ct_entries_ht,
+				    mlx5_tc_ct_flush_ft_entry,
+				    ct_priv);
 	kfree(ft);
 }
 
-- 
2.13.6