2020-02-18 20:00:13

by Madhuparna Bhowmik

Subject: [PATCH 4/4] flow_table.c: Use built-in RCU list checking

From: Madhuparna Bhowmik <[email protected]>

hlist_for_each_entry_rcu() has built-in RCU and lock checking.

Pass cond argument to list_for_each_entry_rcu() to silence
false lockdep warning when CONFIG_PROVE_RCU_LIST is enabled
by default.

Signed-off-by: Madhuparna Bhowmik <[email protected]>
---
net/openvswitch/flow_table.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/openvswitch/flow_table.c b/net/openvswitch/flow_table.c
index 5904e93e5765..fd8a01ca7a2d 100644
--- a/net/openvswitch/flow_table.c
+++ b/net/openvswitch/flow_table.c
@@ -585,7 +585,8 @@ static struct sw_flow *masked_flow_lookup(struct table_instance *ti,
head = find_bucket(ti, hash);
(*n_mask_hit)++;

- hlist_for_each_entry_rcu(flow, head, flow_table.node[ti->node_ver]) {
+ hlist_for_each_entry_rcu(flow, head, flow_table.node[ti->node_ver],
+ lockdep_ovsl_is_held()) {
if (flow->mask == mask && flow->flow_table.hash == hash &&
flow_cmp_masked_key(flow, &masked_key, &mask->range))
return flow;
@@ -769,7 +770,8 @@ struct sw_flow *ovs_flow_tbl_lookup_ufid(struct flow_table *tbl,

hash = ufid_hash(ufid);
head = find_bucket(ti, hash);
- hlist_for_each_entry_rcu(flow, head, ufid_table.node[ti->node_ver]) {
+ hlist_for_each_entry_rcu(flow, head, ufid_table.node[ti->node_ver],
+ lockdep_ovsl_is_held()) {
if (flow->ufid_table.hash == hash &&
ovs_flow_cmp_ufid(flow, ufid))
return flow;
--
2.17.1

2020-02-18 20:51:38

by David Miller

Subject: Re: [PATCH 4/4] flow_table.c: Use built-in RCU list checking

From: [email protected]
Date: Wed, 19 Feb 2020 01:28:20 +0530

> From: Madhuparna Bhowmik <[email protected]>
>
> hlist_for_each_entry_rcu() has built-in RCU and lock checking.
>
> Pass cond argument to list_for_each_entry_rcu() to silence
> false lockdep warning when CONFIG_PROVE_RCU_LIST is enabled
> by default.
>
> Signed-off-by: Madhuparna Bhowmik <[email protected]>

Applied.