Re: [PATCH v2 24/46] mm/writeback: Add __folio_end_writeback()

On Tue, Jun 22, 2021 at 01:15:29PM +0100, Matthew Wilcox (Oracle) wrote:

test_clear_page_writeback() is actually an mm-internal function, although
it's named as if it's a pagecache function.  Move it to mm/internal.h,
rename it to __folio_end_writeback() and change the return type to bool.

The conversion from page to folio is mostly about accounting the number
of pages being written back, although it does eliminate a couple of
calls to compound_head().

While this looks good, I think the whole abstraction is wrong.  I think
test_clear_page_writeback should just be merged into it's only caller.

But if that is somehow not on the table this change looks ok:

Reviewed-by: Christoph Hellwig <hch@lst.de>