mkdir('foobar') or die...;
my $mode = 0770; chmod $mode, 'foobar' or die...; 
chown 'www-data', 'sftp', 'foobar' or die...;

my $upload_filehandle = $query->upload($upload);
open UPLOADFILE, ">$upload_dir/$filename";
binmode UPLOADFILE;
while ( <$upload_filehandle> ) {
   print UPLOADFILE;
}
close UPLOADFILE;
$mode = 0770;   chmod $mode, "$upload_dir/$filename";