mm: replace list_move_tail() with add_page_to_lru_list_tail()

This is a cleanup patch that replaces two historical uses of
list_move_tail() with relatively recent add_page_to_lru_list_tail().

Link: http://lkml.kernel.org/r/20190716212436.7137-1-yuzhao@google.comSigned-off-by: Yu Zhao <yuzhao@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/swap.c

@@ -515,7 +515,6 @@ static void lru_deactivate_file_fn(struct page *page, struct lruvec *lruvec,
 	del_page_from_lru_list(page, lruvec, lru + active);
 	ClearPageActive(page);
 	ClearPageReferenced(page);
-	add_page_to_lru_list(page, lruvec, lru);
 
 	if (PageWriteback(page) || PageDirty(page)) {
 		/*
@@ -523,13 +522,14 @@ static void lru_deactivate_file_fn(struct page *page, struct lruvec *lruvec,
 		 * It can make readahead confusing.  But race window
 		 * is _really_ small and  it's non-critical problem.
 		 */
+		add_page_to_lru_list(page, lruvec, lru);
 		SetPageReclaim(page);
 	} else {
 		/*
 		 * The page's writeback ends up during pagevec
 		 * We moves tha page into tail of inactive.
 		 */
-		list_move_tail(&page->lru, &lruvec->lists[lru]);
+		add_page_to_lru_list_tail(page, lruvec, lru);
 		__count_vm_event(PGROTATED);
 	}
 
@@ -844,17 +844,15 @@ void lru_add_page_tail(struct page *page, struct page *page_tail,
 		get_page(page_tail);
 		list_add_tail(&page_tail->lru, list);
 	} else {
-		struct list_head *list_head;
 		/*
 		 * Head page has not yet been counted, as an hpage,
 		 * so we must account for each subpage individually.
 		 *
-		 * Use the standard add function to put page_tail on the list,
-		 * but then correct its position so they all end up in order.
+		 * Put page_tail on the list at the correct position
+		 * so they all end up in order.
 		 */
-		add_page_to_lru_list(page_tail, lruvec, page_lru(page_tail));
-		list_head = page_tail->lru.prev;
-		list_move_tail(&page_tail->lru, list_head);
+		add_page_to_lru_list_tail(page_tail, lruvec,
+					  page_lru(page_tail));
 	}
 
 	if (!PageUnevictable(page))