mm: Turn deactivate_file_page() into deactivate_file_folio()

This function has one caller which already has a reference to the
page, so we don't need to use get_page_unless_zero().  Also move the
prototype to mm/internal.h.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>

include/linux/swap.h

@@ -372,7 +372,6 @@ extern void lru_add_drain(void);
 extern void lru_add_drain_cpu(int cpu);
 extern void lru_add_drain_cpu_zone(struct zone *zone);
 extern void lru_add_drain_all(void);
-extern void deactivate_file_page(struct page *page);
 extern void deactivate_page(struct page *page);
 extern void mark_page_lazyfree(struct page *page);
 extern void swap_setup(void);

mm/internal.h

@@ -66,6 +66,7 @@ static inline void wake_throttle_isolated(pg_data_t *pgdat)
 vm_fault_t do_swap_page(struct vm_fault *vmf);
 void folio_rotate_reclaimable(struct folio *folio);
 bool __folio_end_writeback(struct folio *folio);
+void deactivate_file_folio(struct folio *folio);
 
 void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
 		unsigned long floor, unsigned long ceiling);

mm/swap.c

@@ -630,32 +630,33 @@ void lru_add_drain_cpu(int cpu)
 }
 
 /**
- * deactivate_file_page - forcefully deactivate a file page
- * @page: page to deactivate
+ * deactivate_file_folio() - Forcefully deactivate a file folio.
+ * @folio: Folio to deactivate.
  *
- * This function hints the VM that @page is a good reclaim candidate,
- * for example if its invalidation fails due to the page being dirty
+ * This function hints to the VM that @folio is a good reclaim candidate,
+ * for example if its invalidation fails due to the folio being dirty
  * or under writeback.
+ *
+ * Context: Caller holds a reference on the page.
  */
-void deactivate_file_page(struct page *page)
+void deactivate_file_folio(struct folio *folio)
 {
+	struct pagevec *pvec;
+
 	/*
-	 * In a workload with many unevictable page such as mprotect,
-	 * unevictable page deactivation for accelerating reclaim is pointless.
+	 * In a workload with many unevictable pages such as mprotect,
+	 * unevictable folio deactivation for accelerating reclaim is pointless.
 	 */
-	if (PageUnevictable(page))
+	if (folio_test_unevictable(folio))
 		return;
 
-	if (likely(get_page_unless_zero(page))) {
-		struct pagevec *pvec;
-
-		local_lock(&lru_pvecs.lock);
-		pvec = this_cpu_ptr(&lru_pvecs.lru_deactivate_file);
+	folio_get(folio);
+	local_lock(&lru_pvecs.lock);
+	pvec = this_cpu_ptr(&lru_pvecs.lru_deactivate_file);
 
-		if (pagevec_add_and_need_flush(pvec, page))
-			pagevec_lru_move_fn(pvec, lru_deactivate_file_fn);
-		local_unlock(&lru_pvecs.lock);
-	}
+	if (pagevec_add_and_need_flush(pvec, &folio->page))
+		pagevec_lru_move_fn(pvec, lru_deactivate_file_fn);
+	local_unlock(&lru_pvecs.lock);
 }
 
 /*

mm/truncate.c

@@ -527,7 +527,7 @@ static unsigned long __invalidate_mapping_pages(struct address_space *mapping,
 			 * of interest and try to speed up its reclaim.
 			 */
 			if (!ret) {
-				deactivate_file_page(&folio->page);
+				deactivate_file_folio(folio);
 				/* It is likely on the pagevec of a remote CPU */
 				if (nr_pagevec)
 					(*nr_pagevec)++;