From f11931314f976cde5ad8bd01046033bc6d241c4d Mon Sep 17 00:00:00 2001
From: Ivan Kozlovic <ivan@synadia.com>
Date: Thu, 30 Jul 2020 10:29:34 -0600
Subject: [PATCH] [FIXED] Deadlock on config reload with routes and account
 service import

Related to #1544

Signed-off-by: Ivan Kozlovic <ivan@synadia.com>
---
 server/reload.go      |  2 ++
 server/reload_test.go | 19 +++++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/server/reload.go b/server/reload.go
index 6a92f2b3..3df1c10c 100644
--- a/server/reload.go
+++ b/server/reload.go
@@ -1129,6 +1129,7 @@ func (s *Server) reloadAuthorization() {
 		s.gacc = nil
 		s.configureAccounts()
 		s.configureAuthorization()
+		s.mu.Unlock()
 
 		s.accounts.Range(func(k, v interface{}) bool {
 			newAcc := v.(*Account)
@@ -1169,6 +1170,7 @@ func (s *Server) reloadAuthorization() {
 			}
 			return true
 		})
+		s.mu.Lock()
 		// Check if we had a default system account.
 		if s.sys != nil && s.sys.account != nil && !s.opts.NoSystemAccount {
 			s.accounts.Store(s.sys.account.Name, s.sys.account)
diff --git a/server/reload_test.go b/server/reload_test.go
index 39cc9ea3..20d942ff 100644
--- a/server/reload_test.go
+++ b/server/reload_test.go
@@ -3100,11 +3100,23 @@ func TestConfigReloadAccountServicesImportExport(t *testing.T) {
 		}
 	}
 	no_sys_acc: true
+	cluster {
+		name: "abc"
+		port: -1
+	}
 	`))
 	defer os.Remove(conf)
 	s, opts := RunServerWithConfig(conf)
 	defer s.Shutdown()
 
+	opts2 := DefaultOptions()
+	opts2.Cluster.Name = "abc"
+	opts2.Routes = RoutesFromStr(fmt.Sprintf("nats://127.0.0.1:%d", opts.Cluster.Port))
+	s2 := RunServer(opts2)
+	defer s2.Shutdown()
+
+	checkClusterFormed(t, s, s2)
+
 	derek, err := nats.Connect(fmt.Sprintf("nats://derek:foo@%s:%d", opts.Host, opts.Port))
 	if err != nil {
 		t.Fatalf("Error on connect: %v", err)
@@ -3148,6 +3160,9 @@ func TestConfigReloadAccountServicesImportExport(t *testing.T) {
 	}); err != nil {
 		t.Fatalf("Error on subscribe: %v", err)
 	}
+	// This subscription is just to make sure that we can update
+	// route map without locking issues during reload.
+	natsSubSync(t, ivan, "bar")
 
 	req := func(t *testing.T, nc *nats.Conn, subj string, reply string) {
 		t.Helper()
@@ -3199,6 +3214,10 @@ func TestConfigReloadAccountServicesImportExport(t *testing.T) {
 		}
 	}
 	no_sys_acc: true
+	cluster {
+		name: "abc"
+		port: -1
+	}
 	`)
 	// This still should work
 	req(t, ivan, "foo", "reply1")