[PATCH] wait_table and zonelist initializing for memory hotadd: add return code for init_current_empty_zone

When add_zone() is called against empty zone (not populated zone), we have to
initialize the zone which didn't initialize at boot time.  But,
init_currently_empty_zone() may fail due to allocation of wait table.  So,
this patch is to catch its error code.

Changes against wait_table is in the next patch.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 70df5c0..71da5c9 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -26,7 +26,7 @@
 
 extern void zonetable_add(struct zone *zone, int nid, int zid, unsigned long pfn,
 			  unsigned long size);
-static void __add_zone(struct zone *zone, unsigned long phys_start_pfn)
+static int __add_zone(struct zone *zone, unsigned long phys_start_pfn)
 {
 	struct pglist_data *pgdat = zone->zone_pgdat;
 	int nr_pages = PAGES_PER_SECTION;
@@ -34,8 +34,15 @@
 	int zone_type;
 
 	zone_type = zone - pgdat->node_zones;
+	if (!populated_zone(zone)) {
+		int ret = 0;
+		ret = init_currently_empty_zone(zone, phys_start_pfn, nr_pages);
+		if (ret < 0)
+			return ret;
+	}
 	memmap_init_zone(nr_pages, nid, zone_type, phys_start_pfn);
 	zonetable_add(zone, nid, zone_type, phys_start_pfn, nr_pages);
+	return 0;
 }
 
 extern int sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
@@ -50,7 +57,11 @@
 	if (ret < 0)
 		return ret;
 
-	__add_zone(zone, phys_start_pfn);
+	ret = __add_zone(zone, phys_start_pfn);
+
+	if (ret < 0)
+		return ret;
+
 	return register_new_memory(__pfn_to_section(phys_start_pfn));
 }