Merge tag 'folio-5.18c' of git://git.infradead.org/users/willy/pagecache

Pull folio updates from Matthew Wilcox:

 - Rewrite how munlock works to massively reduce the contention on
   i_mmap_rwsem (Hugh Dickins):

     https://lore.kernel.org/linux-mm/8e4356d-9622-a7f0-b2c-f116b5f2efea@google.com/

 - Sort out the page refcount mess for ZONE_DEVICE pages (Christoph
   Hellwig):

     https://lore.kernel.org/linux-mm/20220210072828.2930359-1-hch@lst.de/

 - Convert GUP to use folios and make pincount available for order-1
   pages. (Matthew Wilcox)

 - Convert a few more truncation functions to use folios (Matthew
   Wilcox)

 - Convert page_vma_mapped_walk to use PFNs instead of pages (Matthew
   Wilcox)

 - Convert rmap_walk to use folios (Matthew Wilcox)

 - Convert most of shrink_page_list() to use a folio (Matthew Wilcox)

 - Add support for creating large folios in readahead (Matthew Wilcox)

* tag 'folio-5.18c' of git://git.infradead.org/users/willy/pagecache: (114 commits)
  mm/damon: minor cleanup for damon_pa_young
  selftests/vm/transhuge-stress: Support file-backed PMD folios
  mm/filemap: Support VM_HUGEPAGE for file mappings
  mm/readahead: Switch to page_cache_ra_order
  mm/readahead: Align file mappings for non-DAX
  mm/readahead: Add large folio readahead
  mm: Support arbitrary THP sizes
  mm: Make large folios depend on THP
  mm: Fix READ_ONLY_THP warning
  mm/filemap: Allow large folios to be added to the page cache
  mm: Turn can_split_huge_page() into can_split_folio()
  mm/vmscan: Convert pageout() to take a folio
  mm/vmscan: Turn page_check_references() into folio_check_references()
  mm/vmscan: Account large folios correctly
  mm/vmscan: Optimise shrink_page_list for non-PMD-sized folios
  mm/vmscan: Free non-shmem folios without splitting them
  mm/rmap: Constify the rmap_walk_control argument
  mm/rmap: Convert rmap_walk() to take a folio
  mm: Turn page_anon_vma() into folio_anon_vma()
  mm/rmap: Turn page_lock_anon_vma_read() into folio_lock_anon_vma_read()
  ...

1 files changed, 156 insertions, 149 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 499fa86e754a..1678802e03e7 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -979,36 +979,36 @@ void drop_slab(void)
 		drop_slab_node(nid);
 }
 
-static inline int is_page_cache_freeable(struct page *page)
+static inline int is_page_cache_freeable(struct folio *folio)
 {
 	/*
 	 * A freeable page cache page is referenced only by the caller
 	 * that isolated the page, the page cache and optional buffer
 	 * heads at page->private.
 	 */
-	int page_cache_pins = thp_nr_pages(page);
-	return page_count(page) - page_has_private(page) == 1 + page_cache_pins;
+	return folio_ref_count(folio) - folio_test_private(folio) ==
+		1 + folio_nr_pages(folio);
 }
 
 /*
- * We detected a synchronous write error writing a page out.  Probably
+ * We detected a synchronous write error writing a folio out.  Probably
  * -ENOSPC.  We need to propagate that into the address_space for a subsequent
  * fsync(), msync() or close().
  *
  * The tricky part is that after writepage we cannot touch the mapping: nothing
- * prevents it from being freed up.  But we have a ref on the page and once
- * that page is locked, the mapping is pinned.
+ * prevents it from being freed up.  But we have a ref on the folio and once
+ * that folio is locked, the mapping is pinned.
  *
- * We're allowed to run sleeping lock_page() here because we know the caller has
+ * We're allowed to run sleeping folio_lock() here because we know the caller has
  * __GFP_FS.
  */
 static void handle_write_error(struct address_space *mapping,
-				struct page *page, int error)
+				struct folio *folio, int error)
 {
-	lock_page(page);
-	if (page_mapping(page) == mapping)
+	folio_lock(folio);
+	if (folio_mapping(folio) == mapping)
 		mapping_set_error(mapping, error);
-	unlock_page(page);
+	folio_unlock(folio);
 }
 
 static bool skip_throttle_noprogress(pg_data_t *pgdat)
@@ -1155,35 +1155,35 @@ typedef enum {
  * pageout is called by shrink_page_list() for each dirty page.
  * Calls ->writepage().
  */
-static pageout_t pageout(struct page *page, struct address_space *mapping)
+static pageout_t pageout(struct folio *folio, struct address_space *mapping)
 {
 	/*
-	 * If the page is dirty, only perform writeback if that write
+	 * If the folio is dirty, only perform writeback if that write
 	 * will be non-blocking.  To prevent this allocation from being
 	 * stalled by pagecache activity.  But note that there may be
 	 * stalls if we need to run get_block().  We could test
 	 * PagePrivate for that.
 	 *
 	 * If this process is currently in __generic_file_write_iter() against
-	 * this page's queue, we can perform writeback even if that
+	 * this folio's queue, we can perform writeback even if that
 	 * will block.
 	 *
-	 * If the page is swapcache, write it back even if that would
+	 * If the folio is swapcache, write it back even if that would
 	 * block, for some throttling. This happens by accident, because
 	 * swap_backing_dev_info is bust: it doesn't reflect the
 	 * congestion state of the swapdevs.  Easy to fix, if needed.
 	 */
-	if (!is_page_cache_freeable(page))
+	if (!is_page_cache_freeable(folio))
 		return PAGE_KEEP;
 	if (!mapping) {
 		/*
-		 * Some data journaling orphaned pages can have
-		 * page->mapping == NULL while being dirty with clean buffers.
+		 * Some data journaling orphaned folios can have
+		 * folio->mapping == NULL while being dirty with clean buffers.
 		 */
-		if (page_has_private(page)) {
-			if (try_to_free_buffers(page)) {
-				ClearPageDirty(page);
-				pr_info("%s: orphaned page\n", __func__);
+		if (folio_test_private(folio)) {
+			if (try_to_free_buffers(&folio->page)) {
+				folio_clear_dirty(folio);
+				pr_info("%s: orphaned folio\n", __func__);
 				return PAGE_CLEAN;
 			}
 		}
@@ -1192,7 +1192,7 @@ static pageout_t pageout(struct page *page, struct address_space *mapping)
 	if (mapping->a_ops->writepage == NULL)
 		return PAGE_ACTIVATE;
 
-	if (clear_page_dirty_for_io(page)) {
+	if (folio_clear_dirty_for_io(folio)) {
 		int res;
 		struct writeback_control wbc = {
 			.sync_mode = WB_SYNC_NONE,
@@ -1202,21 +1202,21 @@ static pageout_t pageout(struct page *page, struct address_space *mapping)
 			.for_reclaim = 1,
 		};
 
-		SetPageReclaim(page);
-		res = mapping->a_ops->writepage(page, &wbc);
+		folio_set_reclaim(folio);
+		res = mapping->a_ops->writepage(&folio->page, &wbc);
 		if (res < 0)
-			handle_write_error(mapping, page, res);
+			handle_write_error(mapping, folio, res);
 		if (res == AOP_WRITEPAGE_ACTIVATE) {
-			ClearPageReclaim(page);
+			folio_clear_reclaim(folio);
 			return PAGE_ACTIVATE;
 		}
 
-		if (!PageWriteback(page)) {
+		if (!folio_test_writeback(folio)) {
 			/* synchronous write or broken a_ops? */
-			ClearPageReclaim(page);
+			folio_clear_reclaim(folio);
 		}
-		trace_mm_vmscan_writepage(page);
-		inc_node_page_state(page, NR_VMSCAN_WRITE);
+		trace_mm_vmscan_write_folio(folio);
+		node_stat_add_folio(folio, NR_VMSCAN_WRITE);
 		return PAGE_SUCCESS;
 	}
 
@@ -1227,16 +1227,16 @@ static pageout_t pageout(struct page *page, struct address_space *mapping)
  * Same as remove_mapping, but if the page is removed from the mapping, it
  * gets returned with a refcount of 0.
  */
-static int __remove_mapping(struct address_space *mapping, struct page *page,
+static int __remove_mapping(struct address_space *mapping, struct folio *folio,
 			    bool reclaimed, struct mem_cgroup *target_memcg)
 {
 	int refcount;
 	void *shadow = NULL;
 
-	BUG_ON(!PageLocked(page));
-	BUG_ON(mapping != page_mapping(page));
+	BUG_ON(!folio_test_locked(folio));
+	BUG_ON(mapping != folio_mapping(folio));
 
-	if (!PageSwapCache(page))
+	if (!folio_test_swapcache(folio))
 		spin_lock(&mapping->host->i_lock);
 	xa_lock_irq(&mapping->i_pages);
 	/*
@@ -1264,23 +1264,23 @@ static int __remove_mapping(struct address_space *mapping, struct page *page,
 	 * Note that if SetPageDirty is always performed via set_page_dirty,
 	 * and thus under the i_pages lock, then this ordering is not required.
 	 */
-	refcount = 1 + compound_nr(page);
-	if (!page_ref_freeze(page, refcount))
+	refcount = 1 + folio_nr_pages(folio);
+	if (!folio_ref_freeze(folio, refcount))
 		goto cannot_free;
 	/* note: atomic_cmpxchg in page_ref_freeze provides the smp_rmb */
-	if (unlikely(PageDirty(page))) {
-		page_ref_unfreeze(page, refcount);
+	if (unlikely(folio_test_dirty(folio))) {
+		folio_ref_unfreeze(folio, refcount);
 		goto cannot_free;
 	}
 
-	if (PageSwapCache(page)) {
-		swp_entry_t swap = { .val = page_private(page) };
-		mem_cgroup_swapout(page, swap);
+	if (folio_test_swapcache(folio)) {
+		swp_entry_t swap = folio_swap_entry(folio);
+		mem_cgroup_swapout(folio, swap);
 		if (reclaimed && !mapping_exiting(mapping))
-			shadow = workingset_eviction(page, target_memcg);
-		__delete_from_swap_cache(page, swap, shadow);
+			shadow = workingset_eviction(folio, target_memcg);
+		__delete_from_swap_cache(&folio->page, swap, shadow);
 		xa_unlock_irq(&mapping->i_pages);
-		put_swap_page(page, swap);
+		put_swap_page(&folio->page, swap);
 	} else {
 		void (*freepage)(struct page *);
 
@@ -1301,61 +1301,67 @@ static int __remove_mapping(struct address_space *mapping, struct page *page,
 		 * exceptional entries and shadow exceptional entries in the
 		 * same address_space.
 		 */
-		if (reclaimed && page_is_file_lru(page) &&
+		if (reclaimed && folio_is_file_lru(folio) &&
 		    !mapping_exiting(mapping) && !dax_mapping(mapping))
-			shadow = workingset_eviction(page, target_memcg);
-		__delete_from_page_cache(page, shadow);
+			shadow = workingset_eviction(folio, target_memcg);
+		__filemap_remove_folio(folio, shadow);
 		xa_unlock_irq(&mapping->i_pages);
 		if (mapping_shrinkable(mapping))
 			inode_add_lru(mapping->host);
 		spin_unlock(&mapping->host->i_lock);
 
 		if (freepage != NULL)
-			freepage(page);
+			freepage(&folio->page);
 	}
 
 	return 1;
 
 cannot_free:
 	xa_unlock_irq(&mapping->i_pages);
-	if (!PageSwapCache(page))
+	if (!folio_test_swapcache(folio))
 		spin_unlock(&mapping->host->i_lock);
 	return 0;
 }
 
-/*
- * Attempt to detach a locked page from its ->mapping.  If it is dirty or if
- * someone else has a ref on the page, abort and return 0.  If it was
- * successfully detached, return 1.  Assumes the caller has a single ref on
- * this page.
+/**
+ * remove_mapping() - Attempt to remove a folio from its mapping.
+ * @mapping: The address space.
+ * @folio: The folio to remove.
+ *
+ * If the folio is dirty, under writeback or if someone else has a ref
+ * on it, removal will fail.
+ * Return: The number of pages removed from the mapping.  0 if the folio
+ * could not be removed.
+ * Context: The caller should have a single refcount on the folio and
+ * hold its lock.
  */
-int remove_mapping(struct address_space *mapping, struct page *page)
+long remove_mapping(struct address_space *mapping, struct folio *folio)
 {
-	if (__remove_mapping(mapping, page, false, NULL)) {
+	if (__remove_mapping(mapping, folio, false, NULL)) {
 		/*
-		 * Unfreezing the refcount with 1 rather than 2 effectively
+		 * Unfreezing the refcount with 1 effectively
 		 * drops the pagecache ref for us without requiring another
 		 * atomic operation.
 		 */
-		page_ref_unfreeze(page, 1);
-		return 1;
+		folio_ref_unfreeze(folio, 1);
+		return folio_nr_pages(folio);
 	}
 	return 0;
 }
 
 /**
- * putback_lru_page - put previously isolated page onto appropriate LRU list
- * @page: page to be put back to appropriate lru list
+ * folio_putback_lru - Put previously isolated folio onto appropriate LRU list.
+ * @folio: Folio to be returned to an LRU list.
  *
- * Add previously isolated @page to appropriate LRU list.
- * Page may still be unevictable for other reasons.
+ * Add previously isolated @folio to appropriate LRU list.
+ * The folio may still be unevictable for other reasons.
  *
- * lru_lock must not be held, interrupts must be enabled.
+ * Context: lru_lock must not be held, interrupts must be enabled.
  */
-void putback_lru_page(struct page *page)
+void folio_putback_lru(struct folio *folio)
 {
-	lru_cache_add(page);
-	put_page(page);		/* drop ref from isolate */
+	folio_add_lru(folio);
+	folio_put(folio);		/* drop ref from isolate */
 }
 
 enum page_references {
@@ -1365,61 +1371,61 @@ enum page_references {
 	PAGEREF_ACTIVATE,
 };
 
-static enum page_references page_check_references(struct page *page,
+static enum page_references folio_check_references(struct folio *folio,
 						  struct scan_control *sc)
 {
-	int referenced_ptes, referenced_page;
+	int referenced_ptes, referenced_folio;
 	unsigned long vm_flags;
 
-	referenced_ptes = page_referenced(page, 1, sc->target_mem_cgroup,
-					  &vm_flags);
-	referenced_page = TestClearPageReferenced(page);
+	referenced_ptes = folio_referenced(folio, 1, sc->target_mem_cgroup,
+					   &vm_flags);
+	referenced_folio = folio_test_clear_referenced(folio);
 
 	/*
-	 * Mlock lost the isolation race with us.  Let try_to_unmap()
-	 * move the page to the unevictable list.
+	 * The supposedly reclaimable folio was found to be in a VM_LOCKED vma.
+	 * Let the folio, now marked Mlocked, be moved to the unevictable list.
 	 */
 	if (vm_flags & VM_LOCKED)
-		return PAGEREF_RECLAIM;
+		return PAGEREF_ACTIVATE;
 
 	if (referenced_ptes) {
 		/*
-		 * All mapped pages start out with page table
+		 * All mapped folios start out with page table
 		 * references from the instantiating fault, so we need
-		 * to look twice if a mapped file/anon page is used more
+		 * to look twice if a mapped file/anon folio is used more
 		 * than once.
 		 *
 		 * Mark it and spare it for another trip around the
 		 * inactive list.  Another page table reference will
 		 * lead to its activation.
 		 *
-		 * Note: the mark is set for activated pages as well
-		 * so that recently deactivated but used pages are
+		 * Note: the mark is set for activated folios as well
+		 * so that recently deactivated but used folios are
 		 * quickly recovered.
 		 */
-		SetPageReferenced(page);
+		folio_set_referenced(folio);
 
-		if (referenced_page || referenced_ptes > 1)
+		if (referenced_folio || referenced_ptes > 1)
 			return PAGEREF_ACTIVATE;
 
 		/*
-		 * Activate file-backed executable pages after first usage.
+		 * Activate file-backed executable folios after first usage.
 		 */
-		if ((vm_flags & VM_EXEC) && !PageSwapBacked(page))
+		if ((vm_flags & VM_EXEC) && !folio_test_swapbacked(folio))
 			return PAGEREF_ACTIVATE;
 
 		return PAGEREF_KEEP;
 	}
 
-	/* Reclaim if clean, defer dirty pages to writeback */
-	if (referenced_page && !PageSwapBacked(page))
+	/* Reclaim if clean, defer dirty folios to writeback */
+	if (referenced_folio && !folio_test_swapbacked(folio))
 		return PAGEREF_RECLAIM_CLEAN;
 
 	return PAGEREF_RECLAIM;
 }
 
 /* Check if a page is dirty or under writeback */
-static void page_check_dirty_writeback(struct page *page,
+static void folio_check_dirty_writeback(struct folio *folio,
 				       bool *dirty, bool *writeback)
 {
 	struct address_space *mapping;
@@ -1428,24 +1434,24 @@ static void page_check_dirty_writeback(struct page *page,
 	 * Anonymous pages are not handled by flushers and must be written
 	 * from reclaim context. Do not stall reclaim based on them
 	 */
-	if (!page_is_file_lru(page) ||
-	    (PageAnon(page) && !PageSwapBacked(page))) {
+	if (!folio_is_file_lru(folio) ||
+	    (folio_test_anon(folio) && !folio_test_swapbacked(folio))) {
 		*dirty = false;
 		*writeback = false;
 		return;
 	}
 
-	/* By default assume that the page flags are accurate */
-	*dirty = PageDirty(page);
-	*writeback = PageWriteback(page);
+	/* By default assume that the folio flags are accurate */
+	*dirty = folio_test_dirty(folio);
+	*writeback = folio_test_writeback(folio);
 
 	/* Verify dirty/writeback state if the filesystem supports it */
-	if (!page_has_private(page))
+	if (!folio_test_private(folio))
 		return;
 
-	mapping = page_mapping(page);
+	mapping = folio_mapping(folio);
 	if (mapping && mapping->a_ops->is_dirty_writeback)
-		mapping->a_ops->is_dirty_writeback(page, dirty, writeback);
+		mapping->a_ops->is_dirty_writeback(&folio->page, dirty, writeback);
 }
 
 static struct page *alloc_demote_page(struct page *page, unsigned long node)
@@ -1519,14 +1525,16 @@ retry:
 	while (!list_empty(page_list)) {
 		struct address_space *mapping;
 		struct page *page;
+		struct folio *folio;
 		enum page_references references = PAGEREF_RECLAIM;
 		bool dirty, writeback, may_enter_fs;
 		unsigned int nr_pages;
 
 		cond_resched();
 
-		page = lru_to_page(page_list);
-		list_del(&page->lru);
+		folio = lru_to_folio(page_list);
+		list_del(&folio->lru);
+		page = &folio->page;
 
 		if (!trylock_page(page))
 			goto keep;
@@ -1552,12 +1560,12 @@ retry:
 		 * reclaim_congested. kswapd will stall and start writing
 		 * pages if the tail of the LRU is all dirty unqueued pages.
 		 */
-		page_check_dirty_writeback(page, &dirty, &writeback);
+		folio_check_dirty_writeback(folio, &dirty, &writeback);
 		if (dirty || writeback)
-			stat->nr_dirty++;
+			stat->nr_dirty += nr_pages;
 
 		if (dirty && !writeback)
-			stat->nr_unqueued_dirty++;
+			stat->nr_unqueued_dirty += nr_pages;
 
 		/*
 		 * Treat this page as congested if the underlying BDI is or if
@@ -1567,7 +1575,7 @@ retry:
 		 */
 		mapping = page_mapping(page);
 		if (writeback && PageReclaim(page))
-			stat->nr_congested++;
+			stat->nr_congested += nr_pages;
 
 		/*
 		 * If a page at the tail of the LRU is under writeback, there
@@ -1616,7 +1624,7 @@ retry:
 			if (current_is_kswapd() &&
 			    PageReclaim(page) &&
 			    test_bit(PGDAT_WRITEBACK, &pgdat->flags)) {
-				stat->nr_immediate++;
+				stat->nr_immediate += nr_pages;
 				goto activate_locked;
 
 			/* Case 2 above */
@@ -1634,7 +1642,7 @@ retry:
 				 * and it's also appropriate in global reclaim.
 				 */
 				SetPageReclaim(page);
-				stat->nr_writeback++;
+				stat->nr_writeback += nr_pages;
 				goto activate_locked;
 
 			/* Case 3 above */
@@ -1648,7 +1656,7 @@ retry:
 		}
 
 		if (!ignore_references)
-			references = page_check_references(page, sc);
+			references = folio_check_references(folio, sc);
 
 		switch (references) {
 		case PAGEREF_ACTIVATE:
@@ -1681,28 +1689,28 @@ retry:
 			if (!PageSwapCache(page)) {
 				if (!(sc->gfp_mask & __GFP_IO))
 					goto keep_locked;
-				if (page_maybe_dma_pinned(page))
+				if (folio_maybe_dma_pinned(folio))
 					goto keep_locked;
 				if (PageTransHuge(page)) {
 					/* cannot split THP, skip it */
-					if (!can_split_huge_page(page, NULL))
+					if (!can_split_folio(folio, NULL))
 						goto activate_locked;
 					/*
 					 * Split pages without a PMD map right
 					 * away. Chances are some or all of the
 					 * tail pages can be freed without IO.
 					 */
-					if (!compound_mapcount(page) &&
-					    split_huge_page_to_list(page,
-								    page_list))
+					if (!folio_entire_mapcount(folio) &&
+					    split_folio_to_list(folio,
+								page_list))
 						goto activate_locked;
 				}
 				if (!add_to_swap(page)) {
 					if (!PageTransHuge(page))
 						goto activate_locked_split;
 					/* Fallback to swap normal pages */
-					if (split_huge_page_to_list(page,
-								    page_list))
+					if (split_folio_to_list(folio,
+								page_list))
 						goto activate_locked;
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 					count_vm_event(THP_SWPOUT_FALLBACK);
@@ -1716,9 +1724,9 @@ retry:
 				/* Adding to swap updated mapping */
 				mapping = page_mapping(page);
 			}
-		} else if (unlikely(PageTransHuge(page))) {
-			/* Split file THP */
-			if (split_huge_page_to_list(page, page_list))
+		} else if (PageSwapBacked(page) && PageTransHuge(page)) {
+			/* Split shmem THP */
+			if (split_folio_to_list(folio, page_list))
 				goto keep_locked;
 		}
 
@@ -1742,10 +1750,11 @@ retry:
 			enum ttu_flags flags = TTU_BATCH_FLUSH;
 			bool was_swapbacked = PageSwapBacked(page);
 
-			if (unlikely(PageTransHuge(page)))
+			if (PageTransHuge(page) &&
+					thp_order(page) >= HPAGE_PMD_ORDER)
 				flags |= TTU_SPLIT_HUGE_PMD;
 
-			try_to_unmap(page, flags);
+			try_to_unmap(folio, flags);
 			if (page_mapped(page)) {
 				stat->nr_unmap_fail += nr_pages;
 				if (!was_swapbacked && PageSwapBacked(page))
@@ -1793,13 +1802,13 @@ retry:
 			 * starts and then write it out here.
 			 */
 			try_to_unmap_flush_dirty();
-			switch (pageout(page, mapping)) {
+			switch (pageout(folio, mapping)) {
 			case PAGE_KEEP:
 				goto keep_locked;
 			case PAGE_ACTIVATE:
 				goto activate_locked;
 			case PAGE_SUCCESS:
-				stat->nr_pageout += thp_nr_pages(page);
+				stat->nr_pageout += nr_pages;
 
 				if (PageWriteback(page))
 					goto keep;
@@ -1877,7 +1886,7 @@ retry:
 			 */
 			count_vm_event(PGLAZYFREED);
 			count_memcg_page_event(page, PGLAZYFREED);
-		} else if (!mapping || !__remove_mapping(mapping, page, true,
+		} else if (!mapping || !__remove_mapping(mapping, folio, true,
 							 sc->target_mem_cgroup))
 			goto keep_locked;
 
@@ -2132,45 +2141,40 @@ move:
 }
 
 /**
- * isolate_lru_page - tries to isolate a page from its LRU list
- * @page: page to isolate from its LRU list
+ * folio_isolate_lru() - Try to isolate a folio from its LRU list.
+ * @folio: Folio to isolate from its LRU list.
  *
- * Isolates a @page from an LRU list, clears PageLRU and adjusts the
- * vmstat statistic corresponding to whatever LRU list the page was on.
+ * Isolate a @folio from an LRU list and adjust the vmstat statistic
+ * corresponding to whatever LRU list the folio was on.
  *
- * Returns 0 if the page was removed from an LRU list.
- * Returns -EBUSY if the page was not on an LRU list.
- *
- * The returned page will have PageLRU() cleared.  If it was found on
- * the active list, it will have PageActive set.  If it was found on
- * the unevictable list, it will have the PageUnevictable bit set. That flag
+ * The folio will have its LRU flag cleared.  If it was found on the
+ * active list, it will have the Active flag set.  If it was found on the
+ * unevictable list, it will have the Unevictable flag set.  These flags
  * may need to be cleared by the caller before letting the page go.
  *
- * The vmstat statistic corresponding to the list on which the page was
- * found will be decremented.
- *
- * Restrictions:
+ * Context:
  *
  * (1) Must be called with an elevated refcount on the page. This is a
- *     fundamental difference from isolate_lru_pages (which is called
+ *     fundamental difference from isolate_lru_pages() (which is called
  *     without a stable reference).
- * (2) the lru_lock must not be held.
- * (3) interrupts must be enabled.
+ * (2) The lru_lock must not be held.
+ * (3) Interrupts must be enabled.
+ *
+ * Return: 0 if the folio was removed from an LRU list.
+ * -EBUSY if the folio was not on an LRU list.
  */
-int isolate_lru_page(struct page *page)
+int folio_isolate_lru(struct folio *folio)
 {
-	struct folio *folio = page_folio(page);
 	int ret = -EBUSY;
 
-	VM_BUG_ON_PAGE(!page_count(page), page);
-	WARN_RATELIMIT(PageTail(page), "trying to isolate tail page");
+	VM_BUG_ON_FOLIO(!folio_ref_count(folio), folio);
 
-	if (TestClearPageLRU(page)) {
+	if (folio_test_clear_lru(folio)) {
 		struct lruvec *lruvec;
 
-		get_page(page);
+		folio_get(folio);
 		lruvec = folio_lruvec_lock_irq(folio);
-		del_page_from_lru_list(page, lruvec);
+		lruvec_del_folio(lruvec, folio);
 		unlock_page_lruvec_irq(lruvec);
 		ret = 0;
 	}
@@ -2406,7 +2410,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec,
  *
  * If the pages are mostly unmapped, the processing is fast and it is
  * appropriate to hold lru_lock across the whole operation.  But if
- * the pages are mapped, the processing is slow (page_referenced()), so
+ * the pages are mapped, the processing is slow (folio_referenced()), so
  * we should drop lru_lock around each page.  It's impossible to balance
  * this, so instead we remove the pages from the LRU while processing them.
  * It is safe to rely on PG_active against the non-LRU pages in here because
@@ -2426,7 +2430,6 @@ static void shrink_active_list(unsigned long nr_to_scan,
 	LIST_HEAD(l_hold);	/* The pages which were snipped off */
 	LIST_HEAD(l_active);
 	LIST_HEAD(l_inactive);
-	struct page *page;
 	unsigned nr_deactivate, nr_activate;
 	unsigned nr_rotated = 0;
 	int file = is_file_lru(lru);
@@ -2448,9 +2451,13 @@ static void shrink_active_list(unsigned long nr_to_scan,
 	spin_unlock_irq(&lruvec->lru_lock);
 
 	while (!list_empty(&l_hold)) {
+		struct folio *folio;
+		struct page *page;
+
 		cond_resched();
-		page = lru_to_page(&l_hold);
-		list_del(&page->lru);
+		folio = lru_to_folio(&l_hold);
+		list_del(&folio->lru);
+		page = &folio->page;
 
 		if (unlikely(!page_evictable(page))) {
 			putback_lru_page(page);
@@ -2465,8 +2472,8 @@ static void shrink_active_list(unsigned long nr_to_scan,
 			}
 		}
 
-		if (page_referenced(page, 0, sc->target_mem_cgroup,
-				    &vm_flags)) {
+		if (folio_referenced(folio, 0, sc->target_mem_cgroup,
+				     &vm_flags)) {
 			/*
 			 * Identify referenced, file-backed active pages and
 			 * give them one more trip around the active list. So