mm/swap: make __pagevec_lru_add static

__pagevec_lru_add has no callers outside swap.c, so make it static,
and move it to a more logical position in the file.

Link: https://lkml.kernel.org/r/20220617175020.717127-4-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/pagevec.h

@@ -26,7 +26,6 @@ struct pagevec {
 };
 
 void __pagevec_release(struct pagevec *pvec);
-void __pagevec_lru_add(struct pagevec *pvec);
 unsigned pagevec_lookup_range(struct pagevec *pvec,
 			      struct address_space *mapping,
 			      pgoff_t *start, pgoff_t end);

mm/swap.c

@@ -228,6 +228,69 @@ static bool pagevec_add_and_need_flush(struct pagevec *pvec, struct page *page)
 
 typedef void (*move_fn_t)(struct lruvec *lruvec, struct folio *folio);
 
+static void __pagevec_lru_add_fn(struct folio *folio, struct lruvec *lruvec)
+{
+	int was_unevictable = folio_test_clear_unevictable(folio);
+	long nr_pages = folio_nr_pages(folio);
+
+	VM_BUG_ON_FOLIO(folio_test_lru(folio), folio);
+
+	folio_set_lru(folio);
+	/*
+	 * Is an smp_mb__after_atomic() still required here, before
+	 * folio_evictable() tests PageMlocked, to rule out the possibility
+	 * of stranding an evictable folio on an unevictable LRU?  I think
+	 * not, because __munlock_page() only clears PageMlocked while the LRU
+	 * lock is held.
+	 *
+	 * (That is not true of __page_cache_release(), and not necessarily
+	 * true of release_pages(): but those only clear PageMlocked after
+	 * put_page_testzero() has excluded any other users of the page.)
+	 */
+	if (folio_evictable(folio)) {
+		if (was_unevictable)
+			__count_vm_events(UNEVICTABLE_PGRESCUED, nr_pages);
+	} else {
+		folio_clear_active(folio);
+		folio_set_unevictable(folio);
+		/*
+		 * folio->mlock_count = !!folio_test_mlocked(folio)?
+		 * But that leaves __mlock_page() in doubt whether another
+		 * actor has already counted the mlock or not.  Err on the
+		 * safe side, underestimate, let page reclaim fix it, rather
+		 * than leaving a page on the unevictable LRU indefinitely.
+		 */
+		folio->mlock_count = 0;
+		if (!was_unevictable)
+			__count_vm_events(UNEVICTABLE_PGCULLED, nr_pages);
+	}
+
+	lruvec_add_folio(lruvec, folio);
+	trace_mm_lru_insertion(folio);
+}
+
+/*
+ * Add the passed pages to the LRU, then drop the caller's refcount
+ * on them.  Reinitialises the caller's pagevec.
+ */
+static void __pagevec_lru_add(struct pagevec *pvec)
+{
+	int i;
+	struct lruvec *lruvec = NULL;
+	unsigned long flags = 0;
+
+	for (i = 0; i < pagevec_count(pvec); i++) {
+		struct folio *folio = page_folio(pvec->pages[i]);
+
+		lruvec = folio_lruvec_relock_irqsave(folio, lruvec, &flags);
+		__pagevec_lru_add_fn(folio, lruvec);
+	}
+	if (lruvec)
+		unlock_page_lruvec_irqrestore(lruvec, flags);
+	release_pages(pvec->pages, pvec->nr);
+	pagevec_reinit(pvec);
+}
+
 static void folio_batch_move_lru(struct folio_batch *fbatch, move_fn_t move_fn)
 {
 	int i;
@@ -1036,69 +1099,6 @@ void __pagevec_release(struct pagevec *pvec)
 }
 EXPORT_SYMBOL(__pagevec_release);
 
-static void __pagevec_lru_add_fn(struct folio *folio, struct lruvec *lruvec)
-{
-	int was_unevictable = folio_test_clear_unevictable(folio);
-	long nr_pages = folio_nr_pages(folio);
-
-	VM_BUG_ON_FOLIO(folio_test_lru(folio), folio);
-
-	folio_set_lru(folio);
-	/*
-	 * Is an smp_mb__after_atomic() still required here, before
-	 * folio_evictable() tests PageMlocked, to rule out the possibility
-	 * of stranding an evictable folio on an unevictable LRU?  I think
-	 * not, because __munlock_page() only clears PageMlocked while the LRU
-	 * lock is held.
-	 *
-	 * (That is not true of __page_cache_release(), and not necessarily
-	 * true of release_pages(): but those only clear PageMlocked after
-	 * put_page_testzero() has excluded any other users of the page.)
-	 */
-	if (folio_evictable(folio)) {
-		if (was_unevictable)
-			__count_vm_events(UNEVICTABLE_PGRESCUED, nr_pages);
-	} else {
-		folio_clear_active(folio);
-		folio_set_unevictable(folio);
-		/*
-		 * folio->mlock_count = !!folio_test_mlocked(folio)?
-		 * But that leaves __mlock_page() in doubt whether another
-		 * actor has already counted the mlock or not.  Err on the
-		 * safe side, underestimate, let page reclaim fix it, rather
-		 * than leaving a page on the unevictable LRU indefinitely.
-		 */
-		folio->mlock_count = 0;
-		if (!was_unevictable)
-			__count_vm_events(UNEVICTABLE_PGCULLED, nr_pages);
-	}
-
-	lruvec_add_folio(lruvec, folio);
-	trace_mm_lru_insertion(folio);
-}
-
-/*
- * Add the passed pages to the LRU, then drop the caller's refcount
- * on them.  Reinitialises the caller's pagevec.
- */
-void __pagevec_lru_add(struct pagevec *pvec)
-{
-	int i;
-	struct lruvec *lruvec = NULL;
-	unsigned long flags = 0;
-
-	for (i = 0; i < pagevec_count(pvec); i++) {
-		struct folio *folio = page_folio(pvec->pages[i]);
-
-		lruvec = folio_lruvec_relock_irqsave(folio, lruvec, &flags);
-		__pagevec_lru_add_fn(folio, lruvec);
-	}
-	if (lruvec)
-		unlock_page_lruvec_irqrestore(lruvec, flags);
-	release_pages(pvec->pages, pvec->nr);
-	pagevec_reinit(pvec);
-}
-
 /**
  * folio_batch_remove_exceptionals() - Prune non-folios from a batch.
  * @fbatch: The batch to prune