From c7707db477f214714db41d5fcdfd34960be8f3b6 Mon Sep 17 00:00:00 2001
From: Zizhong Zhang <zizhang@linkedin.com>
Date: Thu, 13 Aug 2020 19:36:51 -0700
Subject: [PATCH] Fix #7116, skip the insertion of the same continuation to
 pending dns

---
 iocore/hostdb/HostDB.cc | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/iocore/hostdb/HostDB.cc b/iocore/hostdb/HostDB.cc
index b79f74a4bdc..75ad469089d 100644
--- a/iocore/hostdb/HostDB.cc
+++ b/iocore/hostdb/HostDB.cc
@@ -1586,6 +1586,10 @@ HostDBContinuation::set_check_pending_dns()
 {
   Queue<HostDBContinuation> &q = hostDB.pending_dns_for_hash(hash.hash);
   this->setThreadAffinity(this_ethread());
+  if (q.in(this)) {
+    Warning("Skip the insertion of the same continuation to pending dns");
+    return false;
+  }
   HostDBContinuation *c = q.head;
   for (; c; c = static_cast<HostDBContinuation *>(c->link.next)) {
     if (hash.hash == c->hash.hash) {