Index: linux-2.6/include/linux/pagemap.h
===================================================================
--- linux-2.6.orig/include/linux/pagemap.h
+++ linux-2.6/include/linux/pagemap.h
@@ -11,6 +11,7 @@
 #include <linux/compiler.h>
 #include <asm/uaccess.h>
 #include <linux/gfp.h>
+#include <linux/page-flags.h>
 
 /*
  * Bits in mapping->flags.  The lower __GFP_BITS_SHIFT bits are the page
@@ -58,6 +59,14 @@ static inline struct page *page_cache_ge
 	if (unlikely(!page))
 		return NULL;
 
+#ifndef CONFIG_SMP
+	BUG_ON(page_count(page) == 0);
+	atomic_inc(&page->_count);
+	BUG_ON(page != *pagep);
+	BUG_ON(PageCompound(page) && (struct page *)page_private(page) != page);
+	return page;
+#else
+
 	if (unlikely(!get_page_unless_zero(page)))
 		return NULL;
 
@@ -96,12 +105,16 @@ static inline struct page *page_cache_ge
 	if (unlikely(page != *pagep)) /* page no longer at *pagep? */
 		goto bad_page;
 
+	BUG_ON(PageCompound(page) && (struct page *)page_private(page) != page);
+
 	return page;
 
 bad_page:
 	/* Now that we have a reference, we must do a put_page. */
 	put_page(page);
 	return NULL;
+#endif
+
 }
 
 static inline struct page *page_cache_alloc(struct address_space *x)