controller: properly remove qos policy meters

Remove meters created through set_meter() action if the related entry in
the NB QoS table has been deleted.

Fixes: 885655e ("controller: reconfigure ovs meters for ovn meters")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Acked-by: Mark Michelson <mmichels@redhat.com>
Signed-off-by: Numan Siddique <numans@ovn.org>
(cherry picked from commit 1e1d75c)

controller/ofctrl.c

@@ -2665,6 +2665,13 @@ ofctrl_put(struct ovn_desired_flow_table *lflow_table,
     EXTEND_TABLE_FOR_EACH_INSTALLED (m_installed, next_meter, meters) {
         /* Delete the meter. */
         ofctrl_meter_bands_erase(m_installed, &msgs);
+        if (!strncmp(m_installed->name, "__string: ", 10)) {
+            struct ofputil_meter_mod mm = {
+                .command = OFPMC13_DELETE,
+                .meter = { .meter_id = m_installed->table_id },
+            };
+            add_meter_mod(&mm, &msgs);
+        }
         ovn_extend_table_remove_existing(meters, m_installed);
     }
 

tests/ovn.at

@@ -9403,6 +9403,10 @@ check ovn-nbctl --wait=hv qos-add lsw0 to-lport 1002 'inport=="lp2" && is_chassi
 AT_CHECK([as hv ovs-ofctl dump-meters br-int -O OpenFlow13 | grep meter | wc -l], [0], [4
 ])
 
+check ovn-nbctl qos-del lsw0
+AT_CHECK([as hv ovs-ofctl dump-meters br-int -O OpenFlow13 | grep meter | wc -l], [0], [0
+])
+
 OVN_CLEANUP([hv])
 AT_CLEANUP
 ])