This commit adds a function which can be used to ensure all contents of a directory can be accessed. This function doesn't follow symlinks to check if they're pointing to files which exist. Such symlinks can be useful later. Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack) Upstream-commit: 1dedcd0d376f57abae5cadd38116c1aca2821330 Component: engine