7 uses of FILE_READABLE

drupal_install_fix_file in drupal/includes/install.inc
Attempts to fix file permissions.
drupal_install_mkdir in drupal/includes/install.inc
Creates a directory with the specified permissions.
drupal_verify_install_file in drupal/includes/install.inc
Verifies the state of the specified file.
install_check_requirements in drupal/includes/install.core.inc
Checks installation requirements and reports any errors.
install_configure_form in drupal/includes/install.core.inc
Form constructor for a form to configure the new site.
system_requirements in drupal/modules/system/system.install
Implements hook_requirements().
update_prepare_d7_bootstrap in drupal/includes/update.inc
Performs extra steps required to bootstrap when using a Drupal 6 database.