ofproto-dpif-upcall: Don't delete modified ukeys.

If revalidation returns the result UKEY_DELETE, then both the ukey and
its corresponding flow should be deleted. However, if revalidation
returns UKEY_MODIFY, the ukey itself should be modified in-place and
should not be deleted.

Fix this by only applying the ukey deletion to ukeys whose datapath
operations delete a flow.

This may fix statistics accounting issues in rare cases involving
OpenFlow rule modification where actions are updated but flows remain
the same.

Found by inspection.

Signed-off-by: Joe Stringer <[email protected]>
Acked-by: Jarno Rajahalme <[email protected]>

ofproto/ofproto-dpif-upcall.c

@@ -2053,7 +2053,9 @@ push_ukey_ops(struct udpif *udpif, struct umap *umap,
     push_ukey_ops__(udpif, ops, n_ops);
     ovs_mutex_lock(&umap->mutex);
     for (i = 0; i < n_ops; i++) {
-        ukey_delete(umap, ops[i].ukey);
+        if (ops[i].dop.type == DPIF_OP_FLOW_DEL) {
+            ukey_delete(umap, ops[i].ukey);
+        }
     }
     ovs_mutex_unlock(&umap->mutex);
 }