memcg: make memcg's file mapped consistent with global VM

In global VM, FILE_MAPPED is used but memcg uses MAPPED_FILE.  This makes
grep difficult.  Replace memcg's MAPPED_FILE with FILE_MAPPED

And in global VM, mapped shared memory is accounted into FILE_MAPPED.
But memcg doesn't. fix it.
Note:
  page_is_file_cache() just checks SwapBacked or not.
  So, we need to check PageAnon.

Cc: Balbir Singh <balbir@in.ibm.com>
Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6587f65..0b3efb8 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -67,7 +67,7 @@
 	 */
 	MEM_CGROUP_STAT_CACHE, 	   /* # of pages charged as cache */
 	MEM_CGROUP_STAT_RSS,	   /* # of pages charged as anon rss */
-	MEM_CGROUP_STAT_MAPPED_FILE,  /* # of pages charged as file rss */
+	MEM_CGROUP_STAT_FILE_MAPPED,  /* # of pages charged as file rss */
 	MEM_CGROUP_STAT_PGPGIN_COUNT,	/* # of pages paged in */
 	MEM_CGROUP_STAT_PGPGOUT_COUNT,	/* # of pages paged out */
 	MEM_CGROUP_STAT_EVENTS,	/* sum of pagein + pageout for internal use */
@@ -1227,7 +1227,7 @@
  * Currently used to update mapped file statistics, but the routine can be
  * generalized to update other statistics as well.
  */
-void mem_cgroup_update_mapped_file_stat(struct page *page, int val)
+void mem_cgroup_update_file_mapped(struct page *page, int val)
 {
 	struct mem_cgroup *mem;
 	struct mem_cgroup_stat *stat;
@@ -1235,9 +1235,6 @@
 	int cpu;
 	struct page_cgroup *pc;
 
-	if (!page_is_file_cache(page))
-		return;
-
 	pc = lookup_page_cgroup(page);
 	if (unlikely(!pc))
 		return;
@@ -1257,7 +1254,7 @@
 	stat = &mem->stat;
 	cpustat = &stat->cpustat[cpu];
 
-	__mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE, val);
+	__mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_FILE_MAPPED, val);
 done:
 	unlock_page_cgroup(pc);
 }
@@ -1654,18 +1651,18 @@
 	mem_cgroup_charge_statistics(from, pc, false);
 
 	page = pc->page;
-	if (page_is_file_cache(page) && page_mapped(page)) {
+	if (page_mapped(page) && !PageAnon(page)) {
 		cpu = smp_processor_id();
 		/* Update mapped_file data for mem_cgroup "from" */
 		stat = &from->stat;
 		cpustat = &stat->cpustat[cpu];
-		__mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE,
+		__mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_FILE_MAPPED,
 						-1);
 
 		/* Update mapped_file data for mem_cgroup "to" */
 		stat = &to->stat;
 		cpustat = &stat->cpustat[cpu];
-		__mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE,
+		__mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_FILE_MAPPED,
 						1);
 	}
 
@@ -2889,7 +2886,7 @@
 enum {
 	MCS_CACHE,
 	MCS_RSS,
-	MCS_MAPPED_FILE,
+	MCS_FILE_MAPPED,
 	MCS_PGPGIN,
 	MCS_PGPGOUT,
 	MCS_SWAP,
@@ -2933,8 +2930,8 @@
 	s->stat[MCS_CACHE] += val * PAGE_SIZE;
 	val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
 	s->stat[MCS_RSS] += val * PAGE_SIZE;
-	val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_MAPPED_FILE);
-	s->stat[MCS_MAPPED_FILE] += val * PAGE_SIZE;
+	val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_FILE_MAPPED);
+	s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE;
 	val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGIN_COUNT);
 	s->stat[MCS_PGPGIN] += val;
 	val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGOUT_COUNT);