[PATCH v2] selftests: tc-testing: add one test for flushing explicitly created chain

[renmingshuai]

Add the test for additional reference to chains that are explicitly created
 by RTM_NEWCHAIN message.
The test result:
1..1
ok 1 c2b4 - soft lockup alarm will be not generated after delete the prio 0
 filter of the chain

commit c9a82bec02c3 ("net/sched: cls_api: Fix lockup on flushing explicitly
 created chain")
Signed-off-by: Mingshuai Ren <renmingshuai@xxxxxxxxxx>

---
V1 -> V2
  * add the test result
---
 .../tc-testing/tc-tests/infra/filter.json     | 25 +++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 tools/testing/selftests/tc-testing/tc-tests/infra/filter.json

diff --git a/tools/testing/selftests/tc-testing/tc-tests/infra/filter.json b/tools/testing/selftests/tc-testing/tc-tests/infra/filter.json
new file mode 100644
index 000000000000..c4c778e83da2
--- /dev/null
+++ b/tools/testing/selftests/tc-testing/tc-tests/infra/filter.json
@@ -0,0 +1,25 @@
+[
+    {
+        "id": "c2b4",
+        "name": "soft lockup alarm will be not generated after delete the prio 0 filter of the chain",
+        "category": [
+            "filter",
+            "chain"
+        ],
+        "setup": [
+            "$IP link add dev $DUMMY type dummy || /bin/true",
+            "$TC qdisc add dev $DUMMY root handle 1: htb default 1",
+            "$TC chain add dev $DUMMY",
+            "$TC filter del dev $DUMMY chain 0 parent 1: prio 0"
+        ],
+        "cmdUnderTest": "$TC filter add dev $DUMMY chain 0 parent 1:",
+        "expExitCode": "2",
+        "verifyCmd": "$TC chain ls dev $DUMMY",
+        "matchPattern": "chain parent 1: chain 0",
+        "matchCount": "1",
+        "teardown": [
+            "$TC qdisc del dev $DUMMY root handle 1: htb default 1",
+            "$IP link del dev $DUMMY type dummy"
+        ]
+    }
+]
-- 
2.27.0