On Mon, Nov 14, 2022 at 11:49:27AM +0100, Jan Kara wrote: > On Sun 13-11-22 17:28:55, Christoph Hellwig wrote: > > ->writepage is a very inefficient method to write back data, and only > > used through write_cache_pages or a a fallback when no ->migrate_folio > > method is present. > > > > Signed-off-by: Christoph Hellwig <hch@xxxxxx> > > Looks good! Feel free to add: The testbot found a problem with this: ext2_commit_chunk calls write_one_page for the IS_DIRSYNC case, and write_one_page calls ->writepage. So I think I need to drop this one for now (none of the other file systems calls write_one_page). And then think what best to do about write_one_page/write_one_folio. I suspect just passing a writepage pointer to them might make most sense, as they are only used by a few file systems, and the calling convention with the locked page doesn't lend itself to using ->writepages.