mm: initialize hotplugged pages as reserved

Commit 92923ca3aace ("mm: meminit: only set page reserved in the
memblock region") broke memory hotplug which expects the memmap for
newly added sections to be reserved until onlined by
online_pages_range().  This patch marks hotplugged pages as reserved
when adding new zones.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reported-by: David Vrabel <david.vrabel@citrix.com>
Tested-by: David Vrabel <david.vrabel@citrix.com>
Cc: Nathan Zimmer <nzimmer@sgi.com>
Cc: Robin Holt <holt@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 9 insertions, 1 deletions

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 26fbba7d888f..003dbe4b060d 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -446,7 +446,7 @@ static int __meminit __add_zone(struct zone *zone, unsigned long phys_start_pfn)
         int nr_pages = PAGES_PER_SECTION;
         int nid = pgdat->node_id;
         int zone_type;
-        unsigned long flags;
+        unsigned long flags, pfn;
         int ret;
 
         zone_type = zone - pgdat->node_zones;
@@ -461,6 +461,14 @@ static int __meminit __add_zone(struct zone *zone, unsigned long phys_start_pfn)
         pgdat_resize_unlock(zone->zone_pgdat, &flags);
         memmap_init_zone(nr_pages, nid, zone_type,
                          phys_start_pfn, MEMMAP_HOTPLUG);
+
+        /* online_page_range is called later and expects pages reserved */
+        for (pfn = phys_start_pfn; pfn < phys_start_pfn + nr_pages; pfn++) {
+                if (!pfn_valid(pfn))
+                        continue;
+
+                SetPageReserved(pfn_to_page(pfn));
+        }
         return 0;
 }