[RFC PATCH 17/18] mm: Convert free_swap_cache() to take a folio

["Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>]

All but one caller already has a folio, so convert
free_page_and_swap_cache() to have a folio and remove the call to
page_folio().

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
 include/linux/swap.h |  8 ++++----
 mm/khugepaged.c      |  2 +-
 mm/memory.c          |  2 +-
 mm/swap_state.c      | 12 ++++++------
 4 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/include/linux/swap.h b/include/linux/swap.h
index 493487ed7c38..3536595e3bda 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -449,9 +449,9 @@ static inline unsigned long total_swapcache_pages(void)
 	return global_node_page_state(NR_SWAPCACHE);
 }
 
-extern void free_swap_cache(struct page *page);
-extern void free_page_and_swap_cache(struct page *);
-extern void free_pages_and_swap_cache(struct encoded_page **, int);
+void free_swap_cache(struct folio *folio);
+void free_page_and_swap_cache(struct page *);
+void free_pages_and_swap_cache(struct encoded_page **, int);
 /* linux/mm/swapfile.c */
 extern atomic_long_t nr_swap_pages;
 extern long total_swap_pages;
@@ -534,7 +534,7 @@ static inline void put_swap_device(struct swap_info_struct *si)
 /* used to sanity check ptes in zap_pte_range when CONFIG_SWAP=0 */
 #define free_swap_and_cache(e) is_pfn_swap_entry(e)
 
-static inline void free_swap_cache(struct page *page)
+static inline void free_swap_cache(struct folio *folio)
 {
 }
 
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index afc94c281035..7b83bb6a1199 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -725,7 +725,7 @@ static void __collapse_huge_page_copy_succeeded(pte_t *pte,
 		node_stat_sub_folio(src, NR_ISOLATED_ANON +
 				folio_is_file_lru(src));
 		folio_unlock(src);
-		free_swap_cache(&src->page);
+		free_swap_cache(src);
 		folio_putback_lru(src);
 	}
 }
diff --git a/mm/memory.c b/mm/memory.c
index e35328c2f76e..2611d0fa4465 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3194,7 +3194,7 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
 		folio_put(new_folio);
 	if (old_folio) {
 		if (page_copied)
-			free_swap_cache(&old_folio->page);
+			free_swap_cache(old_folio);
 		folio_put(old_folio);
 	}
 
diff --git a/mm/swap_state.c b/mm/swap_state.c
index f68ddeb93698..e6b4a00d3655 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -282,10 +282,8 @@ void clear_shadow_from_swap_cache(int type, unsigned long begin,
  * folio_free_swap() _with_ the lock.
  * 					- Marcelo
  */
-void free_swap_cache(struct page *page)
+void free_swap_cache(struct folio *folio)
 {
-	struct folio *folio = page_folio(page);
-
 	if (folio_test_swapcache(folio) && !folio_mapped(folio) &&
 	    folio_trylock(folio)) {
 		folio_free_swap(folio);
@@ -299,9 +297,11 @@ void free_swap_cache(struct page *page)
  */
 void free_page_and_swap_cache(struct page *page)
 {
-	free_swap_cache(page);
+	struct folio *folio = page_folio(page);
+
+	free_swap_cache(folio);
 	if (!is_huge_zero_page(page))
-		put_page(page);
+		folio_put(folio);
 }
 
 /*
@@ -316,7 +316,7 @@ void free_pages_and_swap_cache(struct encoded_page **pages, int nr)
 	folio_batch_init(&folios);
 	for (int i = 0; i < nr; i++) {
 		struct folio *folio = page_folio(encoded_page_ptr(pages[i]));
-		free_swap_cache(&folio->page);
+		free_swap_cache(folio);
 		if (folio_batch_add(&folios, folio) == 0)
 			folios_put(&folios);
 	}
-- 
2.40.1