folio-compat: remove lru_cache_add()

There are no longer any callers of lru_cache_add(), so remove it.  This
saves 79 bytes of kernel text.  Also cleanup some comments such that
they reference the new folio_add_lru() instead.

Link: https://lkml.kernel.org/r/20221101175326.13265-6-vishal.moola@gmail.comSigned-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/swap.h

@@ -381,7 +381,6 @@ void lru_note_cost(struct lruvec *lruvec, bool file,
 void lru_note_cost_refault(struct folio *);
 void folio_add_lru(struct folio *);
 void folio_add_lru_vma(struct folio *, struct vm_area_struct *);
-void lru_cache_add(struct page *);
 void mark_page_accessed(struct page *);
 void folio_mark_accessed(struct folio *);
 

mm/folio-compat.c

@@ -76,12 +76,6 @@ bool redirty_page_for_writepage(struct writeback_control *wbc,
 }
 EXPORT_SYMBOL(redirty_page_for_writepage);
 
-void lru_cache_add(struct page *page)
-{
-	folio_add_lru(page_folio(page));
-}
-EXPORT_SYMBOL(lru_cache_add);
-
 void lru_cache_add_inactive_or_unevictable(struct page *page,
 		struct vm_area_struct *vma)
 {

mm/truncate.c

@@ -565,7 +565,7 @@ EXPORT_SYMBOL(invalidate_mapping_pages);
  * refcount.  We do this because invalidate_inode_pages2() needs stronger
  * invalidation guarantees, and cannot afford to leave pages behind because
  * shrink_page_list() has a temp ref on them, or because they're transiently
- * sitting in the lru_cache_add() pagevecs.
+ * sitting in the folio_add_lru() pagevecs.
  */
 static int invalidate_complete_folio2(struct address_space *mapping,
 					struct folio *folio)

mm/workingset.c

@@ -492,7 +492,10 @@ void workingset_refault(struct folio *folio, void *shadow)
 	/* Folio was active prior to eviction */
 	if (workingset) {
 		folio_set_workingset(folio);
-		/* XXX: Move to lru_cache_add() when it supports new vs putback */
+		/*
+		 * XXX: Move to folio_add_lru() when it supports new vs
+		 * putback
+		 */
 		lru_note_cost_refault(folio);
 		mod_lruvec_state(lruvec, WORKINGSET_RESTORE_BASE + file, nr);
 	}