peeling off zone from physical memory layout [10/10] memory_hotplug fix

Index: hogehoge/include/linux/mmzone.h
===================================================================
@@ -28,6 +28,7 @@ struct free_area {
 };
 
 struct pglist_data;
+struct page;
 
 /*
  * zone->lock and zone->lru_lock are two of the hottest locks in the kernel.

@@ -129,10 +130,7 @@ struct zone {
 	 * free areas of different sizes
 	 */
 	spinlock_t		lock;
-#ifdef CONFIG_MEMORY_HOTPLUG
-	/* see spanned/present_pages for more description */
-	seqlock_t		span_seqlock;
-#endif
+
 	struct free_area	free_area[MAX_ORDER];
 
 

Index: hogehoge/include/linux/memory_hotplug.h
===================================================================
@@ -25,29 +25,6 @@ void pgdat_resize_init(struct pglist_dat
 {
 	spin_lock_init(&pgdat->node_size_lock);
 }
-/*
- * Zone resizing functions
- */
-static inline unsigned zone_span_seqbegin(struct zone *zone)
-{
-	return read_seqbegin(&zone->span_seqlock);
-}
-static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
-{
-	return read_seqretry(&zone->span_seqlock, iv);
-}
-static inline void zone_span_writelock(struct zone *zone)
-{
-	write_seqlock(&zone->span_seqlock);
-}
-static inline void zone_span_writeunlock(struct zone *zone)
-{
-	write_sequnlock(&zone->span_seqlock);
-}
-static inline void zone_seqlock_init(struct zone *zone)
-{
-	seqlock_init(&zone->span_seqlock);
-}
 extern int zone_grow_free_lists(struct zone *zone, unsigned long new_nr_pages);
 extern int zone_grow_waitqueues(struct zone *zone, unsigned long nr_pages);
 extern int add_one_highpage(struct page *page, int pfn, int bad_ppro);

@@ -69,17 +46,6 @@ static inline void pgdat_resize_lock(str
 static inline void pgdat_resize_unlock(struct pglist_data *p, unsigned long *f) {}
 static inline void pgdat_resize_init(struct pglist_data *pgdat) {}
 
-static inline unsigned zone_span_seqbegin(struct zone *zone)
-{
-	return 0;
-}
-static inline int zone_span_seqretry(struct zone *zone, unsigned iv)
-{
-	return 0;
-}
-static inline void zone_span_writelock(struct zone *zone) {}
-static inline void zone_span_writeunlock(struct zone *zone) {}
-static inline void zone_seqlock_init(struct zone *zone) {}
 
 static inline int mhp_notimplemented(const char *func)
 {

Index: hogehoge/mm/memory_hotplug.c
===================================================================
@@ -21,6 +21,7 @@
 #include <linux/memory_hotplug.h>
 #include <linux/highmem.h>
 #include <linux/vmalloc.h>
+#include <linux/memorymap.h>
 
 #include <asm/tlbflush.h>
 

@@ -76,23 +77,6 @@ int __add_pages(struct zone *zone, unsig
 	return err;
 }
 
-static void grow_zone_span(struct zone *zone,
-		unsigned long start_pfn, unsigned long end_pfn)
-{
-	unsigned long old_zone_end_pfn;
-
-	zone_span_writelock(zone);
-
-	old_zone_end_pfn = zone->zone_start_pfn + zone->spanned_pages;
-	if (start_pfn < zone->zone_start_pfn)
-		zone->zone_start_pfn = start_pfn;
-
-	if (end_pfn > old_zone_end_pfn)
-		zone->spanned_pages = end_pfn - zone->zone_start_pfn;
-
-	zone_span_writeunlock(zone);
-}
-
 static void grow_pgdat_span(struct pglist_data *pgdat,
 		unsigned long start_pfn, unsigned long end_pfn)
 {

@@ -118,11 +102,12 @@ int online_pages(unsigned long pfn, unsi
 	 * The section can't be removed here because of the
 	 * memory_block->state_sem.
 	 */
+	memory_resize_lock();
 	zone = page_zone(pfn_to_page(pfn));
 	pgdat_resize_lock(zone->zone_pgdat, &flags);
-	grow_zone_span(zone, pfn, pfn + nr_pages);
 	grow_pgdat_span(zone->zone_pgdat, pfn, pfn + nr_pages);
 	pgdat_resize_unlock(zone->zone_pgdat, &flags);
+	memory_resize_unlock();
 
 	for (i = 0; i < nr_pages; i++) {
 		struct page *page = pfn_to_page(pfn + i);

Index: hogehoge/mm/page_alloc.c
===================================================================
@@ -2042,7 +2042,6 @@ static void __init free_area_init_core(s
 		zone->name = zone_names[j];
 		spin_lock_init(&zone->lock);
 		spin_lock_init(&zone->lru_lock);
-		zone_seqlock_init(zone);
 		zone->zone_pgdat = pgdat;
 		zone->free_pages = 0;