1 files changed, 4 insertions, 0 deletions

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 2c6523af5473..83163c096a75 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -407,6 +407,7 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
         int ret;
         struct memory_notify arg;
 
+        lock_memory_hotplug();
         arg.start_pfn = pfn;
         arg.nr_pages = nr_pages;
         arg.status_change_nid = -1;
@@ -419,6 +420,7 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
         ret = notifier_to_errno(ret);
         if (ret) {
                 memory_notify(MEM_CANCEL_ONLINE, &arg);
+                unlock_memory_hotplug();
                 return ret;
         }
         /*
@@ -443,6 +445,7 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
                 printk(KERN_DEBUG "online_pages %lx at %lx failed\n",
                         nr_pages, pfn);
                 memory_notify(MEM_CANCEL_ONLINE, &arg);
+                unlock_memory_hotplug();
                 return ret;
         }
 
@@ -467,6 +470,7 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
 
         if (onlined_pages)
                 memory_notify(MEM_ONLINE, &arg);
+        unlock_memory_hotplug();
 
         return 0;
 }