@@ -104,6 +104,20 @@ func (s *TagStore) recursiveLoad(eng *engine.Engine, address, tmpImageDir string

 			log.Debugf("Error validating ID: %s", err)

 			return err

 		}

+

+		// ensure no two downloads of the same layer happen at the same time

+		if c, err := s.poolAdd("pull", "layer:"+img.ID); err != nil {

+			if c != nil {

+				log.Debugf("Image (id: %s) load is already running, waiting: %v", img.ID, err)

+				<-c

+				return nil

+			}

+

+			return err

+		}

+

+		defer s.poolRemove("pull", "layer:"+img.ID)

+

 		if img.Parent != "" {

 			if !s.graph.Exists(img.Parent) {

 				if err := s.recursiveLoad(eng, img.Parent, tmpImageDir); err != nil {