diff --git a/include/linux/mm.h b/include/linux/mm.h index 3bc394aafbc0..dd5c6970ba67 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2008,7 +2008,6 @@ int redirty_page_for_writepage(struct writeback_control *wbc, bool folio_mark_dirty(struct folio *folio); bool set_page_dirty(struct page *page); int set_page_dirty_lock(struct page *page); -int clear_page_dirty_for_io(struct page *page); int get_cmdline(struct task_struct *task, char *buffer, int buflen); diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 8f4a9ba0bfb0..0dda6459d2d1 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -796,6 +796,8 @@ static inline void cancel_dirty_page(struct page *page) { folio_cancel_dirty(page_folio(page)); } +bool folio_clear_dirty_for_io(struct folio *folio); +bool clear_page_dirty_for_io(struct page *page); int __set_page_dirty_nobuffers(struct page *page); int __set_page_dirty_no_writeback(struct page *page); diff --git a/mm/folio-compat.c b/mm/folio-compat.c index dad962b920e5..39f5a8d963b1 100644 --- a/mm/folio-compat.c +++ b/mm/folio-compat.c @@ -89,3 +89,9 @@ int __set_page_dirty_nobuffers(struct page *page) return filemap_dirty_folio(page_mapping(page), page_folio(page)); } EXPORT_SYMBOL(__set_page_dirty_nobuffers); + +bool clear_page_dirty_for_io(struct page *page) +{ + return folio_clear_dirty_for_io(page_folio(page)); +} +EXPORT_SYMBOL(clear_page_dirty_for_io); diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 16c4ab0cc1c9..85c04445de97 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2681,25 +2681,25 @@ void __folio_cancel_dirty(struct folio *folio) EXPORT_SYMBOL(__folio_cancel_dirty); /* - * Clear a page's dirty flag, while caring for dirty memory accounting. - * Returns true if the page was previously dirty. + * Clear a folio's dirty flag, while caring for dirty memory accounting. + * Returns true if the folio was previously dirty. * - * This is for preparing to put the page under writeout. We leave the page - * tagged as dirty in the xarray so that a concurrent write-for-sync - * can discover it via a PAGECACHE_TAG_DIRTY walk. The ->writepage - * implementation will run either set_page_writeback() or set_page_dirty(), - * at which stage we bring the page's dirty flag and xarray dirty tag - * back into sync. + * This is for preparing to put the folio under writeout. We leave + * the folio tagged as dirty in the xarray so that a concurrent + * write-for-sync can discover it via a PAGECACHE_TAG_DIRTY walk. + * The ->writepage implementation will run either folio_start_writeback() + * or folio_mark_dirty(), at which stage we bring the folio's dirty flag + * and xarray dirty tag back into sync. * - * This incoherency between the page's dirty flag and xarray tag is - * unfortunate, but it only exists while the page is locked. + * This incoherency between the folio's dirty flag and xarray tag is + * unfortunate, but it only exists while the folio is locked. */ -int clear_page_dirty_for_io(struct page *page) +bool folio_clear_dirty_for_io(struct folio *folio) { - struct address_space *mapping = page_mapping(page); - int ret = 0; + struct address_space *mapping = folio_mapping(folio); + bool ret = false; - VM_BUG_ON_PAGE(!PageLocked(page), page); + VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); if (mapping && mapping_can_writeback(mapping)) { struct inode *inode = mapping->host; @@ -2712,48 +2712,49 @@ int clear_page_dirty_for_io(struct page *page) * We use this sequence to make sure that * (a) we account for dirty stats properly * (b) we tell the low-level filesystem to - * mark the whole page dirty if it was + * mark the whole folio dirty if it was * dirty in a pagetable. Only to then - * (c) clean the page again and return 1 to + * (c) clean the folio again and return 1 to * cause the writeback. * * This way we avoid all nasty races with the * dirty bit in multiple places and clearing * them concurrently from different threads. * - * Note! Normally the "set_page_dirty(page)" + * Note! Normally the "folio_mark_dirty(folio)" * has no effect on the actual dirty bit - since * that will already usually be set. But we * need the side effects, and it can help us * avoid races. * - * We basically use the page "master dirty bit" + * We basically use the folio "master dirty bit" * as a serialization point for all the different * threads doing their things. */ - if (page_mkclean(page)) - set_page_dirty(page); + if (folio_mkclean(folio)) + folio_mark_dirty(folio); /* * We carefully synchronise fault handlers against - * installing a dirty pte and marking the page dirty + * installing a dirty pte and marking the folio dirty * at this point. We do this by having them hold the - * page lock while dirtying the page, and pages are + * page lock while dirtying the folio, and folios are * always locked coming in here, so we get the desired * exclusion. */ wb = unlocked_inode_to_wb_begin(inode, &cookie); - if (TestClearPageDirty(page)) { - dec_lruvec_page_state(page, NR_FILE_DIRTY); - dec_zone_page_state(page, NR_ZONE_WRITE_PENDING); - dec_wb_stat(wb, WB_RECLAIMABLE); - ret = 1; + if (folio_test_clear_dirty(folio)) { + long nr = folio_nr_pages(folio); + lruvec_stat_mod_folio(folio, NR_FILE_DIRTY, -nr); + zone_stat_mod_folio(folio, NR_ZONE_WRITE_PENDING, -nr); + wb_stat_mod(wb, WB_RECLAIMABLE, -nr); + ret = true; } unlocked_inode_to_wb_end(inode, &cookie); return ret; } - return TestClearPageDirty(page); + return folio_test_clear_dirty(folio); } -EXPORT_SYMBOL(clear_page_dirty_for_io); +EXPORT_SYMBOL(folio_clear_dirty_for_io); static void wb_inode_writeback_start(struct bdi_writeback *wb) {