1 files changed, 74 insertions, 4 deletions

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 9f646374e32f..6e7d8b21dbfa 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -34,6 +34,17 @@
 
 #include "internal.h"
 
+/*
+ * online_page_callback contains pointer to current page onlining function.
+ * Initially it is generic_online_page(). If it is required it could be
+ * changed by calling set_online_page_callback() for callback registration
+ * and restore_online_page_callback() for generic callback restore.
+ */
+
+static void generic_online_page(struct page *page);
+
+static online_page_callback_t online_page_callback = generic_online_page;
+
 DEFINE_MUTEX(mem_hotplug_mutex);
 
 void lock_memory_hotplug(void)
@@ -361,23 +372,74 @@ int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
 }
 EXPORT_SYMBOL_GPL(__remove_pages);
 
-void online_page(struct page *page)
+int set_online_page_callback(online_page_callback_t callback)
+{
+	int rc = -EINVAL;
+
+	lock_memory_hotplug();
+
+	if (online_page_callback == generic_online_page) {
+		online_page_callback = callback;
+		rc = 0;
+	}
+
+	unlock_memory_hotplug();
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(set_online_page_callback);
+
+int restore_online_page_callback(online_page_callback_t callback)
+{
+	int rc = -EINVAL;
+
+	lock_memory_hotplug();
+
+	if (online_page_callback == callback) {
+		online_page_callback = generic_online_page;
+		rc = 0;
+	}
+
+	unlock_memory_hotplug();
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(restore_online_page_callback);
+
+void __online_page_set_limits(struct page *page)
 {
 	unsigned long pfn = page_to_pfn(page);
 
-	totalram_pages++;
 	if (pfn >= num_physpages)
 		num_physpages = pfn + 1;
+}
+EXPORT_SYMBOL_GPL(__online_page_set_limits);
+
+void __online_page_increment_counters(struct page *page)
+{
+	totalram_pages++;
 
 #ifdef CONFIG_HIGHMEM
 	if (PageHighMem(page))
 		totalhigh_pages++;
 #endif
+}
+EXPORT_SYMBOL_GPL(__online_page_increment_counters);
 
+void __online_page_free(struct page *page)
+{
 	ClearPageReserved(page);
 	init_page_count(page);
 	__free_page(page);
 }
+EXPORT_SYMBOL_GPL(__online_page_free);
+
+static void generic_online_page(struct page *page)
+{
+	__online_page_set_limits(page);
+	__online_page_increment_counters(page);
+	__online_page_free(page);
+}
 
 static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
 			void *arg)
@@ -388,7 +450,7 @@ static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
 	if (PageReserved(pfn_to_page(start_pfn)))
 		for (i = 0; i < nr_pages; i++) {
 			page = pfn_to_page(start_pfn + i);
-			online_page(page);
+			(*online_page_callback)(page);
 			onlined_pages++;
 		}
 	*(unsigned long *)arg = onlined_pages;
@@ -494,6 +556,14 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
 	/* init node's zones as empty zones, we don't have any present pages.*/
 	free_area_init_node(nid, zones_size, start_pfn, zholes_size);
 
+	/*
+	 * The node we allocated has no zone fallback lists. For avoiding
+	 * to access not-initialized zonelist, build here.
+	 */
+	mutex_lock(&zonelists_mutex);
+	build_all_zonelists(NULL);
+	mutex_unlock(&zonelists_mutex);
+
 	return pgdat;
 }
 
@@ -515,7 +585,7 @@ int mem_online_node(int nid)
 
 	lock_memory_hotplug();
 	pgdat = hotadd_new_pgdat(nid, 0);
-	if (pgdat) {
+	if (!pgdat) {
 		ret = -ENOMEM;
 		goto out;
 	}