check phase too

pkg/manager/volumes/pvc_modifier.go

@@ -286,7 +286,7 @@ func (p *pvcModifier) tryToModifyPVC(ctx *componentVolumeContext) error {
 			if !isEvicted {
 				// do not evict leader when resizing PVC (increasing size)
 				// as if the storage size is not enough, the leader eviction will be blocked (never finished)
-				if !volumesSizeNeedModify(actual) {
+				if !skipEvictLeaderForSizeModify(actual) {
 					if ensureTiKVLeaderEvictionCondition(ctx.tc, metav1.ConditionTrue) {
 						// return to sync tc
 						return fmt.Errorf("try to evict leader for tidbcluster %s/%s", ctx.tc.Namespace, ctx.tc.Name)
@@ -321,21 +321,36 @@ func (p *pvcModifier) tryToModifyPVC(ctx *componentVolumeContext) error {
 	return nil
 }
 
-func volumesSizeNeedModify(actual []ActualVolume) bool {
+// skip evict leader if the storage size should be modified or is in modifying phase
+func skipEvictLeaderForSizeModify(actual []ActualVolume) bool {
 	for _, vol := range actual {
 		if vol.PVC == nil || vol.Desired == nil {
 			continue
 		}
-		// check with status, return need to modify if the size is modifying
-		oldSize, ok := vol.PVC.Annotations[annoKeyPVCStatusStorageSize]
-		if !ok {
-			// get from status capacity if not modified by the PVC Modifier before
-			quantity := vol.GetStorageSize()
-			oldSize = quantity.String()
+
+		annoStatusSize, ok := vol.PVC.Annotations[annoKeyPVCStatusStorageSize]
+		if ok {
+			// modified by the PVC Modifier before (with status size annotation)
+			if annoStatusSize == vol.Desired.Size.String() {
+				continue // already up to date, no need to modify size
+			}
+			return true // need to modify size
 		}
-		if oldSize != vol.Desired.Size.String() {
-			return true
+
+		// not modified by the PVC modifier before (without status size annotation)
+		quantity := vol.GetStorageSize()
+		statusSize := quantity.String()
+		klog.Infof("volume %s/%s: phase %s, old size %s, new size %s", vol.PVC.Namespace, vol.PVC.Name, vol.Phase, statusSize, vol.Desired.Size.String())
+		if statusSize == vol.Desired.Size.String() {
+			// special case: skip evict leader (again) as the PVC is in modfiying phase (and the status size annotation is not set yet)
+			if vol.Phase == VolumePhaseModifying {
+				return true
+			}
+			// already modified, in fact, the status size annotation should already be set
+			continue
 		}
+		// need to modify size
+		return true
 	}
 	return false
 }