[PATCH net-next v3 2/3] net: openvswitch: refactor flow free function

[xiangxia . m . yue]

From: Tonghao Zhang <xiangxia.m....@gmail.com>

Decrease table->count and ufid_count unconditionally,
because we only don't use count or ufid_count to count
when flushing the flows. To simplify the codes, we
remove the "count" argument of table_instance_flow_free.

To avoid a bug when deleting flows in the future, add
WARN_ON in flush flows function.

Cc: Pravin B Shelar <pshe...@ovn.org>
Signed-off-by: Tonghao Zhang <xiangxia.m....@gmail.com>
---
v3:
use WARN_ON instead of BUG_ON 
v2:
add more details why refactor this function.
---
 net/openvswitch/flow_table.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/net/openvswitch/flow_table.c b/net/openvswitch/flow_table.c
index 4b7ab62d0e1a..98dad1c5f9d9 100644
--- a/net/openvswitch/flow_table.c
+++ b/net/openvswitch/flow_table.c
@@ -459,18 +459,14 @@ static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu)
 static void table_instance_flow_free(struct flow_table *table,
                                     struct table_instance *ti,
                                     struct table_instance *ufid_ti,
-                                    struct sw_flow *flow,
-                                    bool count)
+                                    struct sw_flow *flow)
 {
        hlist_del_rcu(&flow->flow_table.node[ti->node_ver]);
-       if (count)
-               table->count--;
+       table->count--;
 
        if (ovs_identifier_is_ufid(&flow->id)) {
                hlist_del_rcu(&flow->ufid_table.node[ufid_ti->node_ver]);
-
-               if (count)
-                       table->ufid_count--;
+               table->ufid_count--;
        }
 
        flow_mask_remove(table, flow->mask);
@@ -495,10 +491,16 @@ void table_instance_flow_flush(struct flow_table *table,
                                          flow_table.node[ti->node_ver]) {
 
                        table_instance_flow_free(table, ti, ufid_ti,
-                                                flow, false);
+                                                flow);
                        ovs_flow_free(flow, true);
                }
        }
+
+       if (WARN_ON(table->count != 0 ||
+                   table->ufid_count != 0)) {
+               table->count = 0;
+               table->ufid_count = 0;
+       }
 }
 
 static void table_instance_destroy(struct table_instance *ti,
@@ -635,8 +637,6 @@ int ovs_flow_tbl_flush(struct flow_table *flow_table)
        rcu_assign_pointer(flow_table->ti, new_ti);
        rcu_assign_pointer(flow_table->ufid_ti, new_ufid_ti);
        flow_table->last_rehash = jiffies;
-       flow_table->count = 0;
-       flow_table->ufid_count = 0;
 
        table_instance_flow_flush(flow_table, old_ti, old_ufid_ti);
        table_instance_destroy(old_ti, old_ufid_ti);
@@ -954,7 +954,7 @@ void ovs_flow_tbl_remove(struct flow_table *table, struct 
sw_flow *flow)
        struct table_instance *ufid_ti = ovsl_dereference(table->ufid_ti);
 
        BUG_ON(table->count == 0);
-       table_instance_flow_free(table, ti, ufid_ti, flow, true);
+       table_instance_flow_free(table, ti, ufid_ti, flow);
 }
 
 static struct sw_flow_mask *mask_alloc(void)
-- 
2.23.0