[PATCH] buffermem_pages removal (5/5)

No more users of buffermem_pages are left, remove it.
While at it also remove some orphaned externs around it in swap.h

fs/buffer.c

@@ -36,9 +36,6 @@
 
 #define BH_ENTRY(list) list_entry((list), struct buffer_head, b_assoc_buffers)
 
-/* This is used by some architectures to estimate available memory. */
-atomic_t buffermem_pages = ATOMIC_INIT(0);
-
 /*
  * Hashed waitqueue_head's for wait_on_buffer()
  */
@@ -151,10 +148,6 @@ void __wait_on_buffer(struct buffer_head * bh)
 static inline void
 __set_page_buffers(struct page *page, struct buffer_head *head)
 {
-	struct inode *inode = page->mapping->host;
-
-	if (inode && S_ISBLK(inode->i_mode))
-		atomic_inc(&buffermem_pages);
 	if (page_has_buffers(page))
 		buffer_error();
 	set_page_buffers(page, head);
@@ -164,14 +157,6 @@ __set_page_buffers(struct page *page, struct buffer_head *head)
 static inline void
 __clear_page_buffers(struct page *page)
 {
-	struct address_space *mapping = page->mapping;
-
-	if (mapping) {
-		struct inode *inode = mapping->host;
-
-		if (S_ISBLK(inode->i_mode))
-			atomic_dec(&buffermem_pages);
-	}
 	clear_page_buffers(page);
 	page_cache_release(page);
 }

include/linux/swap.h

@@ -102,12 +102,8 @@ extern unsigned long totalhigh_pages;
 extern unsigned int nr_free_pages(void);
 extern unsigned int nr_free_buffer_pages(void);
 extern unsigned int nr_free_pagecache_pages(void);
-extern unsigned long nr_buffermem_pages(void);
 extern int nr_active_pages;
 extern int nr_inactive_pages;
-extern atomic_t nr_async_pages;
-extern atomic_t buffermem_pages;
-extern spinlock_t pagecache_lock;
 extern void __remove_inode_page(struct page *);
 
 /* Incomplete types for prototype declarations: */

mm/page_alloc.c

@@ -569,11 +569,6 @@ unsigned int nr_free_highpages (void)
 }
 #endif
 
-unsigned long nr_buffermem_pages(void)
-{
-	return atomic_read(&buffermem_pages);
-}
-
 /*
  * Accumulate the page_state information across all CPUs.
  * The result is unavoidably approximate - it can change