Merge tag 'folio-5.16' of git://git.infradead.org/users/willy/pagecache

Pull memory folios from Matthew Wilcox:
 "Add memory folios, a new type to represent either order-0 pages or the
  head page of a compound page. This should be enough infrastructure to
  support filesystems converting from pages to folios.

  The point of all this churn is to allow filesystems and the page cache
  to manage memory in larger chunks than PAGE_SIZE. The original plan
  was to use compound pages like THP does, but I ran into problems with
  some functions expecting only a head page while others expect the
  precise page containing a particular byte.

  The folio type allows a function to declare that it's expecting only a
  head page. Almost incidentally, this allows us to remove various calls
  to VM_BUG_ON(PageTail(page)) and compound_head().

  This converts just parts of the core MM and the page cache. For 5.17,
  we intend to convert various filesystems (XFS and AFS are ready; other
  filesystems may make it) and also convert more of the MM and page
  cache to folios. For 5.18, multi-page folios should be ready.

  The multi-page folios offer some improvement to some workloads. The
  80% win is real, but appears to be an artificial benchmark (postgres
  startup, which isn't a serious workload). Real workloads (eg building
  the kernel, running postgres in a steady state, etc) seem to benefit
  between 0-10%. I haven't heard of any performance losses as a result
  of this series. Nobody has done any serious performance tuning; I
  imagine that tweaking the readahead algorithm could provide some more
  interesting wins. There are also other places where we could choose to
  create large folios and currently do not, such as writes that are
  larger than PAGE_SIZE.

  I'd like to thank all my reviewers who've offered review/ack tags:
  Christoph Hellwig, David Howells, Jan Kara, Jeff Layton, Johannes
  Weiner, Kirill A. Shutemov, Michal Hocko, Mike Rapoport, Vlastimil
  Babka, William Kucharski, Yu Zhao and Zi Yan.

  I'd also like to thank those who gave feedback I incorporated but
  haven't offered up review tags for this part of the series: Nick
  Piggin, Mel Gorman, Ming Lei, Darrick Wong, Ted Ts'o, John Hubbard,
  Hugh Dickins, and probably a few others who I forget"

* tag 'folio-5.16' of git://git.infradead.org/users/willy/pagecache: (90 commits)
  mm/writeback: Add folio_write_one
  mm/filemap: Add FGP_STABLE
  mm/filemap: Add filemap_get_folio
  mm/filemap: Convert mapping_get_entry to return a folio
  mm/filemap: Add filemap_add_folio()
  mm/filemap: Add filemap_alloc_folio
  mm/page_alloc: Add folio allocation functions
  mm/lru: Add folio_add_lru()
  mm/lru: Convert __pagevec_lru_add_fn to take a folio
  mm: Add folio_evictable()
  mm/workingset: Convert workingset_refault() to take a folio
  mm/filemap: Add readahead_folio()
  mm/filemap: Add folio_mkwrite_check_truncate()
  mm/filemap: Add i_blocks_per_folio()
  mm/writeback: Add folio_redirty_for_writepage()
  mm/writeback: Add folio_account_redirty()
  mm/writeback: Add folio_clear_dirty_for_io()
  mm/writeback: Add folio_cancel_dirty()
  mm/writeback: Add folio_account_cleaned()
  mm/writeback: Add filemap_dirty_folio()
  ...

1 files changed, 262 insertions, 214 deletions

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 4812a17b288c..9c64490171e0 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -562,12 +562,12 @@ static unsigned long wp_next_time(unsigned long cur_time)
 	return cur_time;
 }
 
-static void wb_domain_writeout_inc(struct wb_domain *dom,
+static void wb_domain_writeout_add(struct wb_domain *dom,
 				   struct fprop_local_percpu *completions,
-				   unsigned int max_prop_frac)
+				   unsigned int max_prop_frac, long nr)
 {
-	__fprop_inc_percpu_max(&dom->completions, completions,
-			       max_prop_frac);
+	__fprop_add_percpu_max(&dom->completions, completions,
+			       max_prop_frac, nr);
 	/* First event after period switching was turned off? */
 	if (unlikely(!dom->period_time)) {
 		/*
@@ -583,20 +583,20 @@ static void wb_domain_writeout_inc(struct wb_domain *dom,
 
 /*
  * Increment @wb's writeout completion count and the global writeout
- * completion count. Called from test_clear_page_writeback().
+ * completion count. Called from __folio_end_writeback().
  */
-static inline void __wb_writeout_inc(struct bdi_writeback *wb)
+static inline void __wb_writeout_add(struct bdi_writeback *wb, long nr)
 {
 	struct wb_domain *cgdom;
 
-	inc_wb_stat(wb, WB_WRITTEN);
-	wb_domain_writeout_inc(&global_wb_domain, &wb->completions,
-			       wb->bdi->max_prop_frac);
+	wb_stat_mod(wb, WB_WRITTEN, nr);
+	wb_domain_writeout_add(&global_wb_domain, &wb->completions,
+			       wb->bdi->max_prop_frac, nr);
 
 	cgdom = mem_cgroup_wb_domain(wb);
 	if (cgdom)
-		wb_domain_writeout_inc(cgdom, wb_memcg_completions(wb),
-				       wb->bdi->max_prop_frac);
+		wb_domain_writeout_add(cgdom, wb_memcg_completions(wb),
+				       wb->bdi->max_prop_frac, nr);
 }
 
 void wb_writeout_inc(struct bdi_writeback *wb)
@@ -604,7 +604,7 @@ void wb_writeout_inc(struct bdi_writeback *wb)
 	unsigned long flags;
 
 	local_irq_save(flags);
-	__wb_writeout_inc(wb);
+	__wb_writeout_add(wb, 1);
 	local_irq_restore(flags);
 }
 EXPORT_SYMBOL_GPL(wb_writeout_inc);
@@ -1084,7 +1084,7 @@ static void wb_update_write_bandwidth(struct bdi_writeback *wb,
 	 * write_bandwidth = ---------------------------------------------------
 	 *                                          period
 	 *
-	 * @written may have decreased due to account_page_redirty().
+	 * @written may have decreased due to folio_account_redirty().
 	 * Avoid underflowing @bw calculation.
 	 */
 	bw = written - min(written, wb->written_stamp);
@@ -2381,44 +2381,44 @@ int do_writepages(struct address_space *mapping, struct writeback_control *wbc)
 }
 
 /**
- * write_one_page - write out a single page and wait on I/O
- * @page: the page to write
+ * folio_write_one - write out a single folio and wait on I/O.
+ * @folio: The folio to write.
  *
- * The page must be locked by the caller and will be unlocked upon return.
+ * The folio must be locked by the caller and will be unlocked upon return.
  *
  * Note that the mapping's AS_EIO/AS_ENOSPC flags will be cleared when this
  * function returns.
  *
  * Return: %0 on success, negative error code otherwise
  */
-int write_one_page(struct page *page)
+int folio_write_one(struct folio *folio)
 {
-	struct address_space *mapping = page->mapping;
+	struct address_space *mapping = folio->mapping;
 	int ret = 0;
 	struct writeback_control wbc = {
 		.sync_mode = WB_SYNC_ALL,
-		.nr_to_write = 1,
+		.nr_to_write = folio_nr_pages(folio),
 	};
 
-	BUG_ON(!PageLocked(page));
+	BUG_ON(!folio_test_locked(folio));
 
-	wait_on_page_writeback(page);
+	folio_wait_writeback(folio);
 
-	if (clear_page_dirty_for_io(page)) {
-		get_page(page);
-		ret = mapping->a_ops->writepage(page, &wbc);
+	if (folio_clear_dirty_for_io(folio)) {
+		folio_get(folio);
+		ret = mapping->a_ops->writepage(&folio->page, &wbc);
 		if (ret == 0)
-			wait_on_page_writeback(page);
-		put_page(page);
+			folio_wait_writeback(folio);
+		folio_put(folio);
 	} else {
-		unlock_page(page);
+		folio_unlock(folio);
 	}
 
 	if (!ret)
 		ret = filemap_check_errors(mapping);
 	return ret;
 }
-EXPORT_SYMBOL(write_one_page);
+EXPORT_SYMBOL(folio_write_one);
 
 /*
  * For address_spaces which do not use buffers nor write back.
@@ -2438,29 +2438,30 @@ EXPORT_SYMBOL(__set_page_dirty_no_writeback);
  *
  * NOTE: This relies on being atomic wrt interrupts.
  */
-static void account_page_dirtied(struct page *page,
+static void folio_account_dirtied(struct folio *folio,
 		struct address_space *mapping)
 {
 	struct inode *inode = mapping->host;
 
-	trace_writeback_dirty_page(page, mapping);
+	trace_writeback_dirty_folio(folio, mapping);
 
 	if (mapping_can_writeback(mapping)) {
 		struct bdi_writeback *wb;
+		long nr = folio_nr_pages(folio);
 
-		inode_attach_wb(inode, page);
+		inode_attach_wb(inode, &folio->page);
 		wb = inode_to_wb(inode);
 
-		__inc_lruvec_page_state(page, NR_FILE_DIRTY);
-		__inc_zone_page_state(page, NR_ZONE_WRITE_PENDING);
-		__inc_node_page_state(page, NR_DIRTIED);
-		inc_wb_stat(wb, WB_RECLAIMABLE);
-		inc_wb_stat(wb, WB_DIRTIED);
-		task_io_account_write(PAGE_SIZE);
-		current->nr_dirtied++;
-		__this_cpu_inc(bdp_ratelimits);
+		__lruvec_stat_mod_folio(folio, NR_FILE_DIRTY, nr);
+		__zone_stat_mod_folio(folio, NR_ZONE_WRITE_PENDING, nr);
+		__node_stat_mod_folio(folio, NR_DIRTIED, nr);
+		wb_stat_mod(wb, WB_RECLAIMABLE, nr);
+		wb_stat_mod(wb, WB_DIRTIED, nr);
+		task_io_account_write(nr * PAGE_SIZE);
+		current->nr_dirtied += nr;
+		__this_cpu_add(bdp_ratelimits, nr);
 
-		mem_cgroup_track_foreign_dirty(page, wb);
+		mem_cgroup_track_foreign_dirty(folio, wb);
 	}
 }
 
@@ -2469,130 +2470,152 @@ static void account_page_dirtied(struct page *page,
  *
  * Caller must hold lock_page_memcg().
  */
-void account_page_cleaned(struct page *page, struct address_space *mapping,
+void folio_account_cleaned(struct folio *folio, struct address_space *mapping,
 			  struct bdi_writeback *wb)
 {
 	if (mapping_can_writeback(mapping)) {
-		dec_lruvec_page_state(page, NR_FILE_DIRTY);
-		dec_zone_page_state(page, NR_ZONE_WRITE_PENDING);
-		dec_wb_stat(wb, WB_RECLAIMABLE);
-		task_io_account_cancelled_write(PAGE_SIZE);
+		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);
+		task_io_account_cancelled_write(nr * PAGE_SIZE);
 	}
 }
 
 /*
- * Mark the page dirty, and set it dirty in the page cache, and mark the inode
- * dirty.
+ * Mark the folio dirty, and set it dirty in the page cache, and mark
+ * the inode dirty.
  *
- * If warn is true, then emit a warning if the page is not uptodate and has
+ * If warn is true, then emit a warning if the folio is not uptodate and has
  * not been truncated.
  *
  * The caller must hold lock_page_memcg().
  */
-void __set_page_dirty(struct page *page, struct address_space *mapping,
+void __folio_mark_dirty(struct folio *folio, struct address_space *mapping,
 			     int warn)
 {
 	unsigned long flags;
 
 	xa_lock_irqsave(&mapping->i_pages, flags);
-	if (page->mapping) {	/* Race with truncate? */
-		WARN_ON_ONCE(warn && !PageUptodate(page));
-		account_page_dirtied(page, mapping);
-		__xa_set_mark(&mapping->i_pages, page_index(page),
+	if (folio->mapping) {	/* Race with truncate? */
+		WARN_ON_ONCE(warn && !folio_test_uptodate(folio));
+		folio_account_dirtied(folio, mapping);
+		__xa_set_mark(&mapping->i_pages, folio_index(folio),
 				PAGECACHE_TAG_DIRTY);
 	}
 	xa_unlock_irqrestore(&mapping->i_pages, flags);
 }
 
-/*
- * For address_spaces which do not use buffers.  Just tag the page as dirty in
- * the xarray.
+/**
+ * filemap_dirty_folio - Mark a folio dirty for filesystems which do not use buffer_heads.
+ * @mapping: Address space this folio belongs to.
+ * @folio: Folio to be marked as dirty.
+ *
+ * Filesystems which do not use buffer heads should call this function
+ * from their set_page_dirty address space operation.  It ignores the
+ * contents of folio_get_private(), so if the filesystem marks individual
+ * blocks as dirty, the filesystem should handle that itself.
  *
- * This is also used when a single buffer is being dirtied: we want to set the
- * page dirty in that case, but not all the buffers.  This is a "bottom-up"
- * dirtying, whereas __set_page_dirty_buffers() is a "top-down" dirtying.
+ * This is also sometimes used by filesystems which use buffer_heads when
+ * a single buffer is being dirtied: we want to set the folio dirty in
+ * that case, but not all the buffers.  This is a "bottom-up" dirtying,
+ * whereas __set_page_dirty_buffers() is a "top-down" dirtying.
  *
- * The caller must ensure this doesn't race with truncation.  Most will simply
- * hold the page lock, but e.g. zap_pte_range() calls with the page mapped and
- * the pte lock held, which also locks out truncation.
+ * The caller must ensure this doesn't race with truncation.  Most will
+ * simply hold the folio lock, but e.g. zap_pte_range() calls with the
+ * folio mapped and the pte lock held, which also locks out truncation.
  */
-int __set_page_dirty_nobuffers(struct page *page)
+bool filemap_dirty_folio(struct address_space *mapping, struct folio *folio)
 {
-	lock_page_memcg(page);
-	if (!TestSetPageDirty(page)) {
-		struct address_space *mapping = page_mapping(page);
+	folio_memcg_lock(folio);
+	if (folio_test_set_dirty(folio)) {
+		folio_memcg_unlock(folio);
+		return false;
+	}
 
-		if (!mapping) {
-			unlock_page_memcg(page);
-			return 1;
-		}
-		__set_page_dirty(page, mapping, !PagePrivate(page));
-		unlock_page_memcg(page);
+	__folio_mark_dirty(folio, mapping, !folio_test_private(folio));
+	folio_memcg_unlock(folio);
 
-		if (mapping->host) {
-			/* !PageAnon && !swapper_space */
-			__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
-		}
-		return 1;
+	if (mapping->host) {
+		/* !PageAnon && !swapper_space */
+		__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
 	}
-	unlock_page_memcg(page);
-	return 0;
+	return true;
 }
-EXPORT_SYMBOL(__set_page_dirty_nobuffers);
+EXPORT_SYMBOL(filemap_dirty_folio);
 
-/*
- * Call this whenever redirtying a page, to de-account the dirty counters
- * (NR_DIRTIED, WB_DIRTIED, tsk->nr_dirtied), so that they match the written
- * counters (NR_WRITTEN, WB_WRITTEN) in long term. The mismatches will lead to
- * systematic errors in balanced_dirty_ratelimit and the dirty pages position
- * control.
+/**
+ * folio_account_redirty - Manually account for redirtying a page.
+ * @folio: The folio which is being redirtied.
+ *
+ * Most filesystems should call folio_redirty_for_writepage() instead
+ * of this fuction.  If your filesystem is doing writeback outside the
+ * context of a writeback_control(), it can call this when redirtying
+ * a folio, to de-account the dirty counters (NR_DIRTIED, WB_DIRTIED,
+ * tsk->nr_dirtied), so that they match the written counters (NR_WRITTEN,
+ * WB_WRITTEN) in long term. The mismatches will lead to systematic errors
+ * in balanced_dirty_ratelimit and the dirty pages position control.
  */
-void account_page_redirty(struct page *page)
+void folio_account_redirty(struct folio *folio)
 {
-	struct address_space *mapping = page->mapping;
+	struct address_space *mapping = folio->mapping;
 
 	if (mapping && mapping_can_writeback(mapping)) {
 		struct inode *inode = mapping->host;
 		struct bdi_writeback *wb;
 		struct wb_lock_cookie cookie = {};
+		long nr = folio_nr_pages(folio);
 
 		wb = unlocked_inode_to_wb_begin(inode, &cookie);
-		current->nr_dirtied--;
-		dec_node_page_state(page, NR_DIRTIED);
-		dec_wb_stat(wb, WB_DIRTIED);
+		current->nr_dirtied -= nr;
+		node_stat_mod_folio(folio, NR_DIRTIED, -nr);
+		wb_stat_mod(wb, WB_DIRTIED, -nr);
 		unlocked_inode_to_wb_end(inode, &cookie);
 	}
 }
-EXPORT_SYMBOL(account_page_redirty);
+EXPORT_SYMBOL(folio_account_redirty);
 
-/*
- * When a writepage implementation decides that it doesn't want to write this
- * page for some reason, it should redirty the locked page via
- * redirty_page_for_writepage() and it should then unlock the page and return 0
+/**
+ * folio_redirty_for_writepage - Decline to write a dirty folio.
+ * @wbc: The writeback control.
+ * @folio: The folio.
+ *
+ * When a writepage implementation decides that it doesn't want to write
+ * @folio for some reason, it should call this function, unlock @folio and
+ * return 0.
+ *
+ * Return: True if we redirtied the folio.  False if someone else dirtied
+ * it first.
  */
-int redirty_page_for_writepage(struct writeback_control *wbc, struct page *page)
+bool folio_redirty_for_writepage(struct writeback_control *wbc,
+		struct folio *folio)
 {
-	int ret;
+	bool ret;
+	long nr = folio_nr_pages(folio);
+
+	wbc->pages_skipped += nr;
+	ret = filemap_dirty_folio(folio->mapping, folio);
+	folio_account_redirty(folio);
 
-	wbc->pages_skipped++;
-	ret = __set_page_dirty_nobuffers(page);
-	account_page_redirty(page);
 	return ret;
 }
-EXPORT_SYMBOL(redirty_page_for_writepage);
+EXPORT_SYMBOL(folio_redirty_for_writepage);
 
-/*
- * Dirty a page.
+/**
+ * folio_mark_dirty - Mark a folio as being modified.
+ * @folio: The folio.
  *
- * For pages with a mapping this should be done under the page lock for the
- * benefit of asynchronous memory errors who prefer a consistent dirty state.
- * This rule can be broken in some special cases, but should be better not to.
+ * For folios with a mapping this should be done under the page lock
+ * for the benefit of asynchronous memory errors who prefer a consistent
+ * dirty state. This rule can be broken in some special cases,
+ * but should be better not to.
+ *
+ * Return: True if the folio was newly dirtied, false if it was already dirty.
  */
-int set_page_dirty(struct page *page)
+bool folio_mark_dirty(struct folio *folio)
 {
-	struct address_space *mapping = page_mapping(page);
+	struct address_space *mapping = folio_mapping(folio);
 
-	page = compound_head(page);
 	if (likely(mapping)) {
 		/*
 		 * readahead/lru_deactivate_page could remain
@@ -2604,17 +2627,17 @@ int set_page_dirty(struct page *page)
 		 * it will confuse readahead and make it restart the size rampup
 		 * process. But it's a trivial problem.
 		 */
-		if (PageReclaim(page))
-			ClearPageReclaim(page);
-		return mapping->a_ops->set_page_dirty(page);
+		if (folio_test_reclaim(folio))
+			folio_clear_reclaim(folio);
+		return mapping->a_ops->set_page_dirty(&folio->page);
 	}
-	if (!PageDirty(page)) {
-		if (!TestSetPageDirty(page))
-			return 1;
+	if (!folio_test_dirty(folio)) {
+		if (!folio_test_set_dirty(folio))
+			return true;
 	}
-	return 0;
+	return false;
 }
-EXPORT_SYMBOL(set_page_dirty);
+EXPORT_SYMBOL(folio_mark_dirty);
 
 /*
  * set_page_dirty() is racy if the caller has no reference against
@@ -2650,49 +2673,49 @@ EXPORT_SYMBOL(set_page_dirty_lock);
  * page without actually doing it through the VM. Can you say "ext3 is
  * horribly ugly"? Thought you could.
  */
-void __cancel_dirty_page(struct page *page)
+void __folio_cancel_dirty(struct folio *folio)
 {
-	struct address_space *mapping = page_mapping(page);
+	struct address_space *mapping = folio_mapping(folio);
 
 	if (mapping_can_writeback(mapping)) {
 		struct inode *inode = mapping->host;
 		struct bdi_writeback *wb;
 		struct wb_lock_cookie cookie = {};
 
-		lock_page_memcg(page);
+		folio_memcg_lock(folio);
 		wb = unlocked_inode_to_wb_begin(inode, &cookie);
 
-		if (TestClearPageDirty(page))
-			account_page_cleaned(page, mapping, wb);
+		if (folio_test_clear_dirty(folio))
+			folio_account_cleaned(folio, mapping, wb);
 
 		unlocked_inode_to_wb_end(inode, &cookie);
-		unlock_page_memcg(page);
+		folio_memcg_unlock(folio);
 	} else {
-		ClearPageDirty(page);
+		folio_clear_dirty(folio);
 	}
 }
-EXPORT_SYMBOL(__cancel_dirty_page);
+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.
- *
- * 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 incoherency between the page's dirty flag and xarray tag is
- * unfortunate, but it only exists while the page is locked.
+ * 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 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 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;
@@ -2705,48 +2728,49 @@ 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)
 {
@@ -2766,27 +2790,28 @@ static void wb_inode_writeback_end(struct bdi_writeback *wb)
 	queue_delayed_work(bdi_wq, &wb->bw_dwork, BANDWIDTH_INTERVAL);
 }
 
-int test_clear_page_writeback(struct page *page)
+bool __folio_end_writeback(struct folio *folio)
 {
-	struct address_space *mapping = page_mapping(page);
-	int ret;
+	long nr = folio_nr_pages(folio);
+	struct address_space *mapping = folio_mapping(folio);
+	bool ret;
 
-	lock_page_memcg(page);
+	folio_memcg_lock(folio);
 	if (mapping && mapping_use_writeback_tags(mapping)) {
 		struct inode *inode = mapping->host;
 		struct backing_dev_info *bdi = inode_to_bdi(inode);
 		unsigned long flags;
 
 		xa_lock_irqsave(&mapping->i_pages, flags);
-		ret = TestClearPageWriteback(page);
+		ret = folio_test_clear_writeback(folio);
 		if (ret) {
-			__xa_clear_mark(&mapping->i_pages, page_index(page),
+			__xa_clear_mark(&mapping->i_pages, folio_index(folio),
 						PAGECACHE_TAG_WRITEBACK);
 			if (bdi->capabilities & BDI_CAP_WRITEBACK_ACCT) {
 				struct bdi_writeback *wb = inode_to_wb(inode);
 
-				dec_wb_stat(wb, WB_WRITEBACK);
-				__wb_writeout_inc(wb);
+				wb_stat_mod(wb, WB_WRITEBACK, -nr);
+				__wb_writeout_add(wb, nr);
 				if (!mapping_tagged(mapping,
 						    PAGECACHE_TAG_WRITEBACK))
 					wb_inode_writeback_end(wb);
@@ -2799,32 +2824,34 @@ int test_clear_page_writeback(struct page *page)
 
 		xa_unlock_irqrestore(&mapping->i_pages, flags);
 	} else {
-		ret = TestClearPageWriteback(page);
+		ret = folio_test_clear_writeback(folio);
 	}
 	if (ret) {
-		dec_lruvec_page_state(page, NR_WRITEBACK);
-		dec_zone_page_state(page, NR_ZONE_WRITE_PENDING);
-		inc_node_page_state(page, NR_WRITTEN);
+		lruvec_stat_mod_folio(folio, NR_WRITEBACK, -nr);
+		zone_stat_mod_folio(folio, NR_ZONE_WRITE_PENDING, -nr);
+		node_stat_mod_folio(folio, NR_WRITTEN, nr);
 	}
-	unlock_page_memcg(page);
+	folio_memcg_unlock(folio);
 	return ret;
 }
 
-int __test_set_page_writeback(struct page *page, bool keep_write)
+bool __folio_start_writeback(struct folio *folio, bool keep_write)
 {
-	struct address_space *mapping = page_mapping(page);
-	int ret, access_ret;
+	long nr = folio_nr_pages(folio);
+	struct address_space *mapping = folio_mapping(folio);
+	bool ret;
+	int access_ret;
 
-	lock_page_memcg(page);
+	folio_memcg_lock(folio);
 	if (mapping && mapping_use_writeback_tags(mapping)) {
-		XA_STATE(xas, &mapping->i_pages, page_index(page));
+		XA_STATE(xas, &mapping->i_pages, folio_index(folio));
 		struct inode *inode = mapping->host;
 		struct backing_dev_info *bdi = inode_to_bdi(inode);
 		unsigned long flags;
 
 		xas_lock_irqsave(&xas, flags);
 		xas_load(&xas);
-		ret = TestSetPageWriteback(page);
+		ret = folio_test_set_writeback(folio);
 		if (!ret) {
 			bool on_wblist;
 
@@ -2835,84 +2862,105 @@ int __test_set_page_writeback(struct page *page, bool keep_write)
 			if (bdi->capabilities & BDI_CAP_WRITEBACK_ACCT) {
 				struct bdi_writeback *wb = inode_to_wb(inode);
 
-				inc_wb_stat(wb, WB_WRITEBACK);
+				wb_stat_mod(wb, WB_WRITEBACK, nr);
 				if (!on_wblist)
 					wb_inode_writeback_start(wb);
 			}
 
 			/*
-			 * We can come through here when swapping anonymous
-			 * pages, so we don't necessarily have an inode to track
-			 * for sync.
+			 * We can come through here when swapping
+			 * anonymous folios, so we don't necessarily
+			 * have an inode to track for sync.
 			 */
 			if (mapping->host && !on_wblist)
 				sb_mark_inode_writeback(mapping->host);
 		}
-		if (!PageDirty(page))
+		if (!folio_test_dirty(folio))
 			xas_clear_mark(&xas, PAGECACHE_TAG_DIRTY);
 		if (!keep_write)
 			xas_clear_mark(&xas, PAGECACHE_TAG_TOWRITE);
 		xas_unlock_irqrestore(&xas, flags);
 	} else {
-		ret = TestSetPageWriteback(page);
+		ret = folio_test_set_writeback(folio);
 	}
 	if (!ret) {
-		inc_lruvec_page_state(page, NR_WRITEBACK);
-		inc_zone_page_state(page, NR_ZONE_WRITE_PENDING);
+		lruvec_stat_mod_folio(folio, NR_WRITEBACK, nr);
+		zone_stat_mod_folio(folio, NR_ZONE_WRITE_PENDING, nr);
 	}
-	unlock_page_memcg(page);
-	access_ret = arch_make_page_accessible(page);
+	folio_memcg_unlock(folio);
+	access_ret = arch_make_folio_accessible(folio);
 	/*
 	 * If writeback has been triggered on a page that cannot be made
 	 * accessible, it is too late to recover here.
 	 */
-	VM_BUG_ON_PAGE(access_ret != 0, page);
+	VM_BUG_ON_FOLIO(access_ret != 0, folio);
 
 	return ret;
-
 }
-EXPORT_SYMBOL(__test_set_page_writeback);
+EXPORT_SYMBOL(__folio_start_writeback);
 
-/*
- * Wait for a page to complete writeback
+/**
+ * folio_wait_writeback - Wait for a folio to finish writeback.
+ * @folio: The folio to wait for.
+ *
+ * If the folio is currently being written back to storage, wait for the
+ * I/O to complete.
+ *
+ * Context: Sleeps.  Must be called in process context and with
+ * no spinlocks held.  Caller should hold a reference on the folio.
+ * If the folio is not locked, writeback may start again after writeback
+ * has finished.
  */
-void wait_on_page_writeback(struct page *page)
+void folio_wait_writeback(struct folio *folio)
 {
-	while (PageWriteback(page)) {
-		trace_wait_on_page_writeback(page, page_mapping(page));
-		wait_on_page_bit(page, PG_writeback);
+	while (folio_test_writeback(folio)) {
+		trace_folio_wait_writeback(folio, folio_mapping(folio));
+		folio_wait_bit(folio, PG_writeback);
 	}
 }
-EXPORT_SYMBOL_GPL(wait_on_page_writeback);
+EXPORT_SYMBOL_GPL(folio_wait_writeback);
 
-/*
- * Wait for a page to complete writeback.  Returns -EINTR if we get a
- * fatal signal while waiting.
+/**
+ * folio_wait_writeback_killable - Wait for a folio to finish writeback.
+ * @folio: The folio to wait for.
+ *
+ * If the folio is currently being written back to storage, wait for the
+ * I/O to complete or a fatal signal to arrive.
+ *
+ * Context: Sleeps.  Must be called in process context and with
+ * no spinlocks held.  Caller should hold a reference on the folio.
+ * If the folio is not locked, writeback may start again after writeback
+ * has finished.
+ * Return: 0 on success, -EINTR if we get a fatal signal while waiting.
  */
-int wait_on_page_writeback_killable(struct page *page)
+int folio_wait_writeback_killable(struct folio *folio)
 {
-	while (PageWriteback(page)) {
-		trace_wait_on_page_writeback(page, page_mapping(page));
-		if (wait_on_page_bit_killable(page, PG_writeback))
+	while (folio_test_writeback(folio)) {
+		trace_folio_wait_writeback(folio, folio_mapping(folio));
+		if (folio_wait_bit_killable(folio, PG_writeback))
 			return -EINTR;
 	}
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(wait_on_page_writeback_killable);
+EXPORT_SYMBOL_GPL(folio_wait_writeback_killable);
 
 /**
- * wait_for_stable_page() - wait for writeback to finish, if necessary.
- * @page:	The page to wait on.
+ * folio_wait_stable() - wait for writeback to finish, if necessary.
+ * @folio: The folio to wait on.
+ *
+ * This function determines if the given folio is related to a backing
+ * device that requires folio contents to be held stable during writeback.
+ * If so, then it will wait for any pending writeback to complete.
  *
- * This function determines if the given page is related to a backing device
- * that requires page contents to be held stable during writeback.  If so, then
- * it will wait for any pending writeback to complete.
+ * Context: Sleeps.  Must be called in process context and with
+ * no spinlocks held.  Caller should hold a reference on the folio.
+ * If the folio is not locked, writeback may start again after writeback
+ * has finished.
  */
-void wait_for_stable_page(struct page *page)
+void folio_wait_stable(struct folio *folio)
 {
-	page = thp_head(page);
-	if (page->mapping->host->i_sb->s_iflags & SB_I_STABLE_WRITES)
-		wait_on_page_writeback(page);
+	if (folio->mapping->host->i_sb->s_iflags & SB_I_STABLE_WRITES)
+		folio_wait_writeback(folio);
 }
-EXPORT_SYMBOL_GPL(wait_for_stable_page);
+EXPORT_SYMBOL_GPL(folio_wait_stable);