From 9e254754759c8ec102e7a5d01e1e4701c5e0ab76 Mon Sep 17 00:00:00 2001
From: Poorna <poornas@users.noreply.github.com>
Date: Tue, 29 Mar 2022 10:10:06 -0700
Subject: [PATCH] Validate tier manager is initialized in tier Empty() check
 (#14646)

Co-authored-by: Poorna Krishnamoorthy <poorna@minio.io>
---
 cmd/metrics-v2.go | 6 +++---
 cmd/tier.go       | 3 +++
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/cmd/metrics-v2.go b/cmd/metrics-v2.go
index 15c789b3f..80ee2c271 100644
--- a/cmd/metrics-v2.go
+++ b/cmd/metrics-v2.go
@@ -1651,13 +1651,13 @@ func getClusterTierMetrics() *MetricsGroup {
 		cacheInterval: 10 * time.Second,
 	}
 	mg.RegisterRead(func(ctx context.Context) (metrics []Metric) {
-		if globalTierConfigMgr.Empty() {
-			return
-		}
 		objLayer := newObjectLayerFn()
 		if objLayer == nil || globalIsGateway {
 			return
 		}
+		if globalTierConfigMgr.Empty() {
+			return
+		}
 
 		dui, err := loadDataUsageFromBackend(GlobalContext, objLayer)
 		if err != nil {
diff --git a/cmd/tier.go b/cmd/tier.go
index 824bb3025..486b1522b 100644
--- a/cmd/tier.go
+++ b/cmd/tier.go
@@ -148,6 +148,9 @@ func (config *TierConfigMgr) Verify(ctx context.Context, tier string) error {
 
 // Empty returns if tier targets are empty
 func (config *TierConfigMgr) Empty() bool {
+	if config == nil {
+		return true
+	}
 	return len(config.ListTiers()) == 0
 }