On Thu, Jul 15, 2021 at 03:05:05PM -0700, Darrick J. Wong wrote: > On Thu, Jul 15, 2021 at 04:36:32AM +0100, Matthew Wilcox (Oracle) wrote: > > Writeback an entire folio at a time, and adjust some of the variables > > to have more familiar names. > > @@ -1398,16 +1397,15 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc, > > static int > > iomap_do_writepage(struct page *page, struct writeback_control *wbc, void *data) > > I imagine at some point this will become iomap_do_writefolio and ther > will be some sort of write_cache_folios() call? Or the equivalent > while(get_next_folio_to_wrote()) iomap_write_folio(); type loop? I hadn't quite got as far as planning out what to do next with a replacement for write_cache_pages(). At a minimum, that function is going to work on folios -- it does anyway; we don't tag tail pages in the xarray, so the tagged lookup done by write_cache_pages() only finds folios. So everything we do with a page there is definitely looking at a folio. I want to get a lot more filesystems converted to use folios before I undertake the write_cache_pages() interface overhaul (and I'll probably think of several things to do to it at the same time -- like working on a batch of pages all at once instead of calling one indirect function per folio).
