[ovs-dev] [PATCH v5 2/9] datapath: Make flow mask removal symmetric.
Jarno Rajahalme
jrajahalme at nicira.com
Tue Mar 25 21:35:52 UTC 2014
Masks are inserted when flows are inserted to the table, so it is
logical to correspondingly remove masks when flows are removed from
the table, in ovs_flow_table_remove().
This allows later patches to relax the locking requirements of
ovs_flow_free().
Signed-off-by: Jarno Rajahalme <jrajahalme at nicira.com>
---
datapath/flow_table.c | 43 ++++++++++++++++++++++++-------------------
1 file changed, 24 insertions(+), 19 deletions(-)
diff --git a/datapath/flow_table.c b/datapath/flow_table.c
index 54a2e25..a680895 100644
--- a/datapath/flow_table.c
+++ b/datapath/flow_table.c
@@ -168,25 +168,6 @@ void ovs_flow_free(struct sw_flow *flow, bool deferred)
if (!flow)
return;
- if (flow->mask) {
- struct sw_flow_mask *mask = flow->mask;
-
- /* ovs-lock is required to protect mask-refcount and
- * mask list.
- */
- ASSERT_OVSL();
- BUG_ON(!mask->ref_count);
- mask->ref_count--;
-
- if (!mask->ref_count) {
- list_del_rcu(&mask->list);
- if (deferred)
- call_rcu(&mask->rcu, rcu_free_sw_flow_mask_cb);
- else
- kfree(mask);
- }
- }
-
if (deferred)
call_rcu(&flow->rcu, rcu_free_flow_callback);
else
@@ -500,6 +481,25 @@ static struct table_instance *table_instance_expand(struct table_instance *ti)
return table_instance_rehash(ti, ti->n_buckets * 2);
}
+/* Remove 'mask' from the mask list, if it is not needed any more. */
+static void flow_mask_remove(struct flow_table *tbl, struct sw_flow_mask *mask)
+{
+ if (mask) {
+ /* ovs-lock is required to protect mask-refcount and
+ * mask list.
+ */
+ ASSERT_OVSL();
+ BUG_ON(!mask->ref_count);
+ mask->ref_count--;
+
+ if (!mask->ref_count) {
+ list_del_rcu(&mask->list);
+ call_rcu(&mask->rcu, rcu_free_sw_flow_mask_cb);
+ }
+ }
+}
+
+/* Must be called with OVS mutex held. */
void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow)
{
struct table_instance *ti = ovsl_dereference(table->ti);
@@ -507,6 +507,10 @@ void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow)
BUG_ON(table->count == 0);
hlist_del_rcu(&flow->hash_node[ti->node_ver]);
table->count--;
+
+ /* RCU delete the mask. 'flow->mask' is not NULLed, as it should be
+ * accessible as long as the RCU read lock is held. */
+ flow_mask_remove(table, flow->mask);
}
static struct sw_flow_mask *mask_alloc(void)
@@ -569,6 +573,7 @@ static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow,
return 0;
}
+/* Must be called with OVS mutex held. */
int ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow,
struct sw_flow_mask *mask)
{
--
1.7.10.4
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