On Mon, Aug 12, 2024 at 08:11:57PM +0800, Zhang Yi wrote: > From: Zhang Yi <yi.zhang@xxxxxxxxxx> > > When doing page mkwrite, iomap_folio_mkwrite_iter() dirty the entire > folio by folio_mark_dirty() even the map length is shorter than one > folio. However, on the filesystem with more than one blocks per folio, > we'd better to only set counterpart block's dirty bit according to > iomap_length(), so open code folio_mark_dirty() and pass the correct > length. What about moving the folio_mark_dirty out of the loop and directly into iomap_page_mkwrite so that it is exactly called once? The iterator then does nothing for the !buffer_head case (but we still need to call it to allocate the blocks).