diff -up wordpress/wp-admin/includes/class-wp-upgrader.php.noupdate wordpress/wp-admin/includes/class-wp-upgrader.php
--- wordpress/wp-admin/includes/class-wp-upgrader.php.noupdate	2015-04-03 02:18:27.000000000 +0200
+++ wordpress/wp-admin/includes/class-wp-upgrader.php	2015-04-24 10:33:31.166724612 +0200
@@ -2142,6 +2142,9 @@ class Core_Upgrader extends WP_Upgrader
 			}
 		}
 
+		// RPM: nether allow core update
+		return false;
+
 		// 1: If we're already on that version, not much point in updating?
 		if ( $offered_ver == $wp_version )
 			return false;
@@ -2373,7 +2376,7 @@ class WP_Automatic_Updater {
 	 */
 	public function is_disabled() {
 		// Background updates are disabled if you don't want file changes.
-		if ( defined( 'DISALLOW_FILE_MODS' ) && DISALLOW_FILE_MODS )
+		if ( !defined( 'DISALLOW_FILE_MODS' ) || DISALLOW_FILE_MODS )
 			return true;
 
 		if ( defined( 'WP_INSTALLING' ) )
diff -up wordpress/wp-admin/includes/update.php.noupdate wordpress/wp-admin/includes/update.php
--- wordpress/wp-admin/includes/update.php.noupdate	2015-04-24 10:37:28.288734495 +0200
+++ wordpress/wp-admin/includes/update.php	2015-04-24 10:37:46.985814124 +0200
@@ -211,8 +211,6 @@ function update_nag() {
 	}
 	echo "<div class='update-nag'>$msg</div>";
 }
-add_action( 'admin_notices', 'update_nag', 3 );
-add_action( 'network_admin_notices', 'update_nag', 3 );
 
 // Called directly from dashboard
 function update_right_now_message() {
@@ -227,7 +225,7 @@ function update_right_now_message() {
 		$cur = get_preferred_from_update_core();
 
 		if ( isset( $cur->response ) && $cur->response == 'upgrade' )
-			$msg .= '<a href="' . network_admin_url( 'update-core.php' ) . '" class="button" aria-describedby="wp-version">' . sprintf( __( 'Update to %s' ), $cur->current ? $cur->current : __( 'Latest' ) ) . '</a> ';
+			$msg .= '';
 	}
 
 	$msg .= sprintf( '<span id="wp-version">' . __( 'WordPress %1$s running %2$s theme.' ) . '</span>', get_bloginfo( 'version', 'display' ), $theme_name );
diff -up wordpress/wp-includes/capabilities.php.noupdate wordpress/wp-includes/capabilities.php
--- wordpress/wp-includes/capabilities.php.noupdate	2015-04-20 09:27:27.000000000 +0200
+++ wordpress/wp-includes/capabilities.php	2015-04-24 10:33:31.167724617 +0200
@@ -1281,7 +1281,7 @@ function map_meta_cap( $cap, $user_id )
 		// Disallow the file editors.
 		if ( defined( 'DISALLOW_FILE_EDIT' ) && DISALLOW_FILE_EDIT )
 			$caps[] = 'do_not_allow';
-		elseif ( defined( 'DISALLOW_FILE_MODS' ) && DISALLOW_FILE_MODS )
+		elseif ( !defined( 'DISALLOW_FILE_MODS' ) || DISALLOW_FILE_MODS )
 			$caps[] = 'do_not_allow';
 		elseif ( is_multisite() && ! is_super_admin( $user_id ) )
 			$caps[] = 'do_not_allow';
@@ -1299,7 +1299,7 @@ function map_meta_cap( $cap, $user_id )
 	case 'update_core':
 		// Disallow anything that creates, deletes, or updates core, plugin, or theme files.
 		// Files in uploads are excepted.
-		if ( defined( 'DISALLOW_FILE_MODS' ) && DISALLOW_FILE_MODS ) {
+		if ( !defined( 'DISALLOW_FILE_MODS' ) || DISALLOW_FILE_MODS ) {
 			$caps[] = 'do_not_allow';
 		} elseif ( is_multisite() && ! is_super_admin( $user_id ) ) {
 			$caps[] = 'do_not_allow';
diff -up wordpress/wp-includes/update.php.noupdate wordpress/wp-includes/update.php
--- wordpress/wp-includes/update.php.noupdate	2015-03-18 23:07:28.000000000 +0100
+++ wordpress/wp-includes/update.php	2015-04-24 10:33:31.167724617 +0200
@@ -624,9 +624,6 @@ function _maybe_update_themes() {
  * @since 3.1.0
  */
 function wp_schedule_update_checks() {
-	if ( !wp_next_scheduled('wp_version_check') && !defined('WP_INSTALLING') )
-		wp_schedule_event(time(), 'twicedaily', 'wp_version_check');
-
 	if ( !wp_next_scheduled('wp_update_plugins') && !defined('WP_INSTALLING') )
 		wp_schedule_event(time(), 'twicedaily', 'wp_update_plugins');
 
@@ -668,8 +665,6 @@ if ( ( ! is_main_site() && ! is_network_
 }
 
 add_action( 'admin_init', '_maybe_update_core' );
-add_action( 'wp_version_check', 'wp_version_check' );
-add_action( 'upgrader_process_complete', 'wp_version_check', 10, 0 );
 
 add_action( 'load-plugins.php', 'wp_update_plugins' );
 add_action( 'load-update.php', 'wp_update_plugins' );