Warning: SplFileInfo::openFile(***/app/tmp/cache/persistent/myapp_cake_core_file_map): failed to open stream: Permission denied inの解決法

core.php

/**
 * Configure the cache used for general framework caching. Path information,
 * object listings, and translation cache files are stored with this configuration.
 */
Cache::config('_cake_core_', array(
    'engine' => $engine,
    'prefix' => $prefix . 'cake_core_',
    'path' => CACHE . 'persistent' . DS,
    'serialize' => ($engine === 'File'),
    'duration' => $duration,
    'mask' => 0666
));

/**
 * Configure the cache for model and datasource caches. This cache configuration
 * is used to store schema descriptions, and table listings in connections.
 */
Cache::config('_cake_model_', array(
    'engine' => $engine,
    'prefix' => $prefix . 'cake_model_',
    'path' => CACHE . 'models' . DS,
    'serialize' => ($engine === 'File'),
    'duration' => $duration,
    'mask' => 0666
));

core.phpに以下を追加。
'mask' => 0666

myapp_cake_core_file_mapを削除するとWarningが出なくなる。