Re: [PATCH v2 29/46] mm/writeback: Add folio_account_cleaned()

[Matthew Wilcox]

On Wed, Jun 23, 2021 at 11:36:14AM +0200, Christoph Hellwig wrote:
> On Tue, Jun 22, 2021 at 01:15:34PM +0100, Matthew Wilcox (Oracle) wrote:
> > Get the statistics right; compound pages were being accounted as a
> > single page.
> 
> Maybe reword this a little to document the existing function that got
> it wrong, and why it did not matter before.

Get the statistics right; compound pages were being accounted as a
single page.  This didn't matter before now as no filesystem which
supported compound pages did writeback.  Also move the declaration
to filemap.h since this is part of the page cache.  Add a wrapper for
account_page_cleaned().