On Mon, Feb 14, 2022 at 03:09:09PM -0800, John Hubbard wrote:
> > @@ -309,7 +288,10 @@ int invalidate_inode_page(struct page *page)
>
> It would be nice to retain some of the original comments. May I suggest
> this (it has an additional paragraph) for an updated version of comments
> above invalidate_inode_page():
>
> /*
> * Safely invalidate one page from its pagecache mapping.
> * It only drops clean, unused pages. The page must be locked.
> *
> * This function can be called at any time, and is not supposed to throw away
> * dirty pages. But pages can be marked dirty at any time too, so use
> * remove_mapping(), which safely discards clean, unused pages.
> *
> * Returns 1 if the page is successfully invalidated, otherwise 0.
> */
By the end of this series, it becomes:
/**
* invalidate_inode_page() - Remove an unused page from the pagecache.
* @page: The page to remove.
*
* Safely invalidate one page from its pagecache mapping.
* It only drops clean, unused pages.
*
* Context: Page must be locked.
* Return: The number of pages successfully removed.
*/
> Also, as long as you're there, a newline after the mapping declaration
> would bring this routine into compliance with that convention.
Again, by the end, we're at:
struct folio *folio = page_folio(page);
struct address_space *mapping = folio_mapping(folio);
/* The page may have been truncated before it was locked */
if (!mapping)
return 0;
return mapping_shrink_folio(mapping, folio);
> hmmm, now I wonder why this isn't a boolean function. And I think the
> reason is that it's quite old.
We could make this return a bool and have the one user that cares
call folio_nr_pages(). I don't have a strong preference.
> Either way, looks good:
>
> Reviewed-by: John Hubbard <jhubbard@xxxxxxxxxx>
Thanks!
