Support tier-add if tier backend not empty (#16715)

cmd/tier-handlers.go

@@ -21,6 +21,7 @@ import (
 	"encoding/json"
 	"io"
 	"net/http"
+	"strconv"
 
 	jsoniter "github.com/json-iterator/go"
 	"github.com/minio/madmin-go/v2"
@@ -94,6 +95,11 @@ func (api adminAPIHandlers) AddTierHandler(w http.ResponseWriter, r *http.Reques
 		return
 	}
 
+	var ignoreInUse bool
+	if forceStr := r.Form.Get("force"); forceStr != "" {
+		ignoreInUse, _ = strconv.ParseBool(forceStr)
+	}
+
 	// Disallow remote tiers with internal storage class names
 	switch cfg.Name {
 	case storageclass.STANDARD, storageclass.RRS:
@@ -107,7 +113,7 @@ func (api adminAPIHandlers) AddTierHandler(w http.ResponseWriter, r *http.Reques
 		return
 	}
 
-	err = globalTierConfigMgr.Add(ctx, cfg)
+	err = globalTierConfigMgr.Add(ctx, cfg, ignoreInUse)
 	if err != nil {
 		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, err), r.URL)
 		return

cmd/tier.go

@@ -103,7 +103,7 @@ func (config *TierConfigMgr) isTierNameInUse(tierName string) (madmin.TierType,
 }
 
 // Add adds tier to config if it passes all validations.
-func (config *TierConfigMgr) Add(ctx context.Context, tier madmin.TierConfig) error {
+func (config *TierConfigMgr) Add(ctx context.Context, tier madmin.TierConfig, ignoreInUse bool) error {
 	config.Lock()
 	defer config.Unlock()
 
@@ -122,13 +122,16 @@ func (config *TierConfigMgr) Add(ctx context.Context, tier madmin.TierConfig) er
 	if err != nil {
 		return err
 	}
-	// Check if warmbackend is in use by other MinIO tenants
-	inUse, err := d.InUse(ctx)
-	if err != nil {
-		return err
-	}
-	if inUse {
-		return errTierBackendInUse
+
+	if !ignoreInUse {
+		// Check if warmbackend is in use by other MinIO tenants
+		inUse, err := d.InUse(ctx)
+		if err != nil {
+			return err
+		}
+		if inUse {
+			return errTierBackendInUse
+		}
 	}
 
 	config.Tiers[tierName] = tier