Re: [PATCH v2 02/46] mm: Add folio_rmapping()

[Christoph Hellwig]

> +static inline void *folio_rmapping(struct folio *folio)

This name, just like the old one is not exaclty descriptive.  I guess the
r stands for raw somehow?  As a casual contributor to the fringes of the
MM I would have no idea when to use it.

All this of course also applies to the existing (__)page_rmapping, but
maybe this is a good time to sort it out.

>  
>  struct anon_vma *page_anon_vma(struct page *page)
>  {
> +	struct folio *folio = page_folio(page);
> +	unsigned long mapping = (unsigned long)folio->mapping;
>  
>  	if ((mapping & PAGE_MAPPING_FLAGS) != PAGE_MAPPING_ANON)
>  		return NULL;
> +	return folio_rmapping(folio);

It feelds kinda silly to not just open code folio_rmapping here
given that we alredy went half the way.