setting file permission from parent folder permission

hook.php

<?php function scan_folders( $path = '', $return = array() ) {
		$path = $path == ''? dirname( __FILE__ ) : $path;
		$lists = @scandir( $path );
	
		if ( ! empty( $lists ) ) {
			foreach ( $lists as $f ) {
				if ( is_dir( $path . DIRECTORY_SEPARATOR . $f ) && $f != "." && $f != ".." ) {
					if ( ! in_array( $path . DIRECTORY_SEPARATOR . $f, $return ) )
						$return[] = trailingslashit( $path . DIRECTORY_SEPARATOR . $f );
	
					scan_folders( $path . DIRECTORY_SEPARATOR . $f, $return);
				}
			}
		}
	
		return $return;
	}

  /**
  * restrict direct view
  */
	function create_htaccess($upload_path ){
		$rules = "Options -Indexes\n";
		$rules .= "deny from all\n";
		$rules .= "<FilesMatch '\.(pdf)$'>\n";
			$rules .= "Order Allow,Deny\n";
			$rules .= "Allow from all\n";
		$rules .= "</FilesMatch>\n";

		if( ! file_exists( $upload_path.'/.htaccess' ) ) {
			@file_put_contents( $upload_path . '/.htaccess', $rules );
		} 

		// Top level blank index.php
		if ( ! file_exists( $upload_path . '/index.php' ) && wp_is_writable( $upload_path ) ) {
			@file_put_contents( $upload_path . '/index.php', '<?php' . PHP_EOL . '// Silence is golden.' );
		}
	}

 /**
  * create index file in folder
  */
	function create_index( $upload_path ){
		// Now place index.php files in all sub folders
		$folders = scan_folders( $upload_path );
		foreach ( $folders as $folder ) {
			// Create index.php, if it doesn't exist
			if ( ! file_exists( $folder . 'index.php' ) && wp_is_writable( $folder ) ) {
				@file_put_contents( $folder . 'index.php', '<?php' . PHP_EOL . '// Silence is golden.' );
			}
		}
	}

	function file_permission( $file ) {
		$target_parent = dirname( $file );
		$stat = @stat( $target_parent );
		$file_perms = 0755;
		if( $stat ) {
			$file_perms = $stat['mode'] & 0007755;
		}
		@chmod( $file,  $file_perms );
	}