[RFC PATCH 4/3] Fix previous patch and add header.

[Ondřej Bílka]

On Tue, May 26, 2015 at 08:55:34PM +0200, Ondřej Bílka wrote:
> 
Now I get second thoughts which are nasty.

So I decided to resubmit this as all these functions follow same
template so I will just write this template and add few specific bits.