Handle the case of root uid

pkg/storage/utils/eosfs/eosfs.go

@@ -1514,11 +1514,17 @@ func (fs *eosfs) getUIDGateway(ctx context.Context, u *userpb.UserId) (string, s
 
 func (fs *eosfs) getUserIDGateway(ctx context.Context, uid string) (*userpb.UserId, error) {
 	log := appctx.GetLogger(ctx)
+	// Handle the case of root
+	if uid == "0" {
+		return nil, errtypes.BadRequest("eosfs: cannot return root user")
+	}
+
 	if userIDInterface, err := fs.userIDCache.Get(uid); err == nil {
 		log.Debug().Msg("eosfs: found cached uid " + uid)
 		return userIDInterface.(*userpb.UserId), nil
 	}
-	log.Debug().Msg("eosfs: retrieving user if from gateway for uid " + uid)
+
+	log.Debug().Msg("eosfs: retrieving user from gateway for uid " + uid)
 	client, err := pool.GetGatewayServiceClient(fs.conf.GatewaySvc)
 	if err != nil {
 		return nil, errors.Wrap(err, "eos: error getting gateway grpc client")