mm: convert find_get_incore_page() to filemap_get_incore_folio()

Return the containing folio instead of the precise page.  One of the
callers wants the folio and the other can do the folio->page conversion
itself.  Nets 442 bytes of text size reduction, 478 bytes removed and 36
bytes added.

Link: https://lkml.kernel.org/r/20221019183332.2802139-4-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/memcontrol.c

@@ -5648,15 +5648,21 @@ static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
 static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
 			unsigned long addr, pte_t ptent)
 {
+	unsigned long index;
+	struct folio *folio;
+
 	if (!vma->vm_file) /* anonymous vma */
 		return NULL;
 	if (!(mc.flags & MOVE_FILE))
 		return NULL;
 
-	/* page is moved even if it's not RSS of this task(page-faulted). */
+	/* folio is moved even if it's not RSS of this task(page-faulted). */
 	/* shmem/tmpfs may report page out on swap: account for that too. */
-	return find_get_incore_page(vma->vm_file->f_mapping,
-			linear_page_index(vma, addr));
+	index = linear_page_index(vma, addr);
+	folio = filemap_get_incore_folio(vma->vm_file->f_mapping, index);
+	if (!folio)
+		return NULL;
+	return folio_file_page(folio, index);
 }
 
 /**

mm/mincore.c

@@ -52,7 +52,7 @@ static int mincore_hugetlb(pte_t *pte, unsigned long hmask, unsigned long addr,
 static unsigned char mincore_page(struct address_space *mapping, pgoff_t index)
 {
 	unsigned char present = 0;
-	struct page *page;
+	struct folio *folio;
 
 	/*
 	 * When tmpfs swaps out a page from a file, any process mapping that
@@ -60,10 +60,10 @@ static unsigned char mincore_page(struct address_space *mapping, pgoff_t index)
 	 * any other file mapping (ie. marked !present and faulted in with
 	 * tmpfs's .fault). So swapped out tmpfs mappings are tested here.
 	 */
-	page = find_get_incore_page(mapping, index);
-	if (page) {
-		present = PageUptodate(page);
-		put_page(page);
+	folio = filemap_get_incore_folio(mapping, index);
+	if (folio) {
+		present = folio_test_uptodate(folio);
+		folio_put(folio);
 	}
 
 	return present;

mm/swap.h

@@ -41,7 +41,8 @@ void clear_shadow_from_swap_cache(int type, unsigned long begin,
 				  unsigned long end);
 struct folio *swap_cache_get_folio(swp_entry_t entry,
 		struct vm_area_struct *vma, unsigned long addr);
-struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index);
+struct folio *filemap_get_incore_folio(struct address_space *mapping,
+		pgoff_t index);
 
 struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
 				   struct vm_area_struct *vma,
@@ -105,9 +106,10 @@ static inline struct folio *swap_cache_get_folio(swp_entry_t entry,
 }
 
 static inline
-struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index)
+struct folio *filemap_get_incore_folio(struct address_space *mapping,
+		pgoff_t index)
 {
-	return find_get_page(mapping, index);
+	return filemap_get_folio(mapping, index);
 }
 
 static inline bool add_to_swap(struct folio *folio)

mm/swap_state.c

@@ -373,16 +373,17 @@ struct folio *swap_cache_get_folio(swp_entry_t entry,
 }
 
 /**
- * find_get_incore_page - Find and get a page from the page or swap caches.
+ * filemap_get_incore_folio - Find and get a folio from the page or swap caches.
  * @mapping: The address_space to search.
  * @index: The page cache index.
  *
- * This differs from find_get_page() in that it will also look for the
- * page in the swap cache.
+ * This differs from filemap_get_folio() in that it will also look for the
+ * folio in the swap cache.
  *
- * Return: The found page or %NULL.
+ * Return: The found folio or %NULL.
  */
-struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index)
+struct folio *filemap_get_incore_folio(struct address_space *mapping,
+		pgoff_t index)
 {
 	swp_entry_t swp;
 	struct swap_info_struct *si;
@@ -405,9 +406,7 @@ struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index)
 	folio = filemap_get_folio(swap_address_space(swp), index);
 	put_swap_device(si);
 out:
-	if (!folio)
-		return NULL;
-	return folio_file_page(folio, index);
+	return folio;
 }
 
 struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,