[PATCH] net: openvswitch: introduce common code for flushing flows
From: <hidden>
Date: 2020-08-11 01:10:29
From: Tonghao Zhang <redacted> To avoid some issues, for example RCU usage warning, we should flush the flows under ovs_lock. This patch refactors table_instance_destroy and introduces table_instance_flow_flush which can be invoked by __dp_destroy or ovs_flow_tbl_flush. Signed-off-by: Tonghao Zhang <redacted> --- net/openvswitch/datapath.c | 11 ++++++++++- net/openvswitch/flow_table.c | 37 ++++++++++++++++-------------------- net/openvswitch/flow_table.h | 3 +++ 3 files changed, 29 insertions(+), 22 deletions(-)
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 42f8cc70bb2c..5fec47e62615 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c@@ -1756,6 +1756,9 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info) /* Called with ovs_mutex. */ static void __dp_destroy(struct datapath *dp) { + struct flow_table *table = &dp->table; + struct table_instance *ufid_ti = ovsl_dereference(table->ufid_ti); + struct table_instance *ti = ovsl_dereference(table->ti); int i; for (i = 0; i < DP_VPORT_HASH_BUCKETS; i++) {
@@ -1774,7 +1777,13 @@ static void __dp_destroy(struct datapath *dp) */ ovs_dp_detach_port(ovs_vport_ovsl(dp, OVSP_LOCAL)); - /* RCU destroy the flow table */ + /* Flush sw_flow in the tables. RCU cb only releases resource + * such as dp, ports and tables. That may avoid some issue + * (e.g RCU usage warning). + */ + table_instance_flow_flush(table, ti, ufid_ti); + + /* RCU destroy the ports, meters and flow tables. */ call_rcu(&dp->rcu, destroy_dp_rcu); }
diff --git a/net/openvswitch/flow_table.c b/net/openvswitch/flow_table.c
index 8c12675cbb67..513024265294 100644
--- a/net/openvswitch/flow_table.c
+++ b/net/openvswitch/flow_table.c@@ -473,42 +473,36 @@ static void table_instance_flow_free(struct flow_table *table, flow_mask_remove(table, flow->mask); } -static void table_instance_destroy(struct flow_table *table, - struct table_instance *ti, - struct table_instance *ufid_ti, - bool deferred) +/* Must be called with OVS mutex held. */ +void table_instance_flow_flush(struct flow_table *table, + struct table_instance *ti, + struct table_instance *ufid_ti) { int i; - if (!ti) - return; - - BUG_ON(!ufid_ti); if (ti->keep_flows) - goto skip_flows; + return; for (i = 0; i < ti->n_buckets; i++) { - struct sw_flow *flow; struct hlist_head *head = &ti->buckets[i]; struct hlist_node *n; + struct sw_flow *flow; hlist_for_each_entry_safe(flow, n, head, flow_table.node[ti->node_ver]) { table_instance_flow_free(table, ti, ufid_ti, flow, false); - ovs_flow_free(flow, deferred); + ovs_flow_free(flow, true); } } +} -skip_flows: - if (deferred) { - call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb); - call_rcu(&ufid_ti->rcu, flow_tbl_destroy_rcu_cb); - } else { - __table_instance_destroy(ti); - __table_instance_destroy(ufid_ti); - } +static void table_instance_destroy(struct table_instance *ti, + struct table_instance *ufid_ti) +{ + call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb); + call_rcu(&ufid_ti->rcu, flow_tbl_destroy_rcu_cb); } /* No need for locking this function is called from RCU callback or
@@ -523,7 +517,7 @@ void ovs_flow_tbl_destroy(struct flow_table *table) call_rcu(&mc->rcu, mask_cache_rcu_cb); call_rcu(&ma->rcu, mask_array_rcu_cb); - table_instance_destroy(table, ti, ufid_ti, false); + table_instance_destroy(ti, ufid_ti); } struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *ti,
@@ -641,7 +635,8 @@ int ovs_flow_tbl_flush(struct flow_table *flow_table) flow_table->count = 0; flow_table->ufid_count = 0; - table_instance_destroy(flow_table, old_ti, old_ufid_ti, true); + table_instance_flow_flush(flow_table, old_ti, old_ufid_ti); + table_instance_destroy(old_ti, old_ufid_ti); return 0; err_free_ti:
diff --git a/net/openvswitch/flow_table.h b/net/openvswitch/flow_table.h
index 74ce48fecba9..6e7d4ac59353 100644
--- a/net/openvswitch/flow_table.h
+++ b/net/openvswitch/flow_table.h@@ -105,5 +105,8 @@ void ovs_flow_mask_key(struct sw_flow_key *dst, const struct sw_flow_key *src, bool full, const struct sw_flow_mask *mask); void ovs_flow_masks_rebalance(struct flow_table *table); +void table_instance_flow_flush(struct flow_table *table, + struct table_instance *ti, + struct table_instance *ufid_ti); #endif /* flow_table.h */
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2.23.0