dpif-netdev: Fix a race condition in deletion of offloaded flows.

In dp_netdev_pmd_remove_flow() we schedule the deletion of an offloaded flow, if a mark has been assigned to the flow. But if this occurs in the window in which the offload thread completes offloading the flow and assigns a mark to the flow, then we miss deleting the flow. This problem has been observed while adding and deleting flows in a loop. To fix this, always enqueue flow deletion regardless of the flow->mark being set. Fixes: 241bad1("dpif-netdev: associate flow with a mark id") Co-authored-by: Gaetan Rivet <[email protected]> Signed-off-by: Gaetan Rivet <[email protected]> Signed-off-by: Sriharsha Basavapatna <[email protected]> Signed-off-by: Ilya Maximets <[email protected]>
zhaozhanxu · Feb 16, 2022 · 7d8b6ab · 7d8b6ab
1 parent a81bb67
commit 7d8b6ab
Showing 1 changed file with 5 additions and 3 deletions.
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
@@ -2929,6 +2929,10 @@ queue_netdev_flow_del(struct dp_netdev_pmd_thread *pmd,
 {
     struct dp_offload_thread_item *offload;
 
+    if (!netdev_is_flow_api_enabled()) {
+        return;
+    }
+
     offload = dp_netdev_alloc_flow_offload(pmd, flow,
                                            DP_NETDEV_FLOW_OFFLOAD_OP_DEL);
     offload->timestamp = pmd->ctx.now;
@@ -3040,9 +3044,7 @@ dp_netdev_pmd_remove_flow(struct dp_netdev_pmd_thread *pmd,
     dp_netdev_simple_match_remove(pmd, flow);
     cmap_remove(&pmd->flow_table, node, dp_netdev_flow_hash(&flow->ufid));
     ccmap_dec(&pmd->n_flows, odp_to_u32(in_port));
-    if (flow->mark != INVALID_FLOW_MARK) {
-        queue_netdev_flow_del(pmd, flow);
-    }
+    queue_netdev_flow_del(pmd, flow);
     flow->dead = true;
 
     dp_netdev_flow_unref(flow);