---
 include/linux/page-flags.h |   15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

Index: linux-2.6/include/linux/page-flags.h
===================================================================
--- linux-2.6.orig/include/linux/page-flags.h	2008-02-17 21:31:56.000000000 -0800
+++ linux-2.6/include/linux/page-flags.h	2008-02-17 21:32:51.000000000 -0800
@@ -81,7 +81,7 @@ enum pageflags {
 	PG_reserved,
 	PG_private,		/* If pagecache, has fs-private data */
 	PG_writeback,		/* Page is under writeback */
-	PG_compound,		/* A compound page */
+	PG_head,		/* Head of a compound page */
 	PG_swapcache,		/* Swap page: swp_entry_t in private */
 	PG_mappedtodisk,	/* Has blocks allocated on-disk */
 	PG_reclaim,		/* To be reclaimed asap */
@@ -239,8 +239,10 @@ static inline void set_page_writeback(st
 	test_set_page_writeback(page);
 }
 
-TESTPAGEFLAG(Compound, compound)
-__PAGEFLAG(Head, compound)
+#define PG_compound	PG_head
+
+__PAGEFLAG(Compound, head)
+__PAGEFLAG(Head, head)
 
 /*
  * PG_reclaim is used in combination with PG_compound to mark the
@@ -267,4 +269,11 @@ static inline void __ClearPageTail(struc
 	page->flags &= ~PG_head_tail_mask;
 }
 
+/*
+ * Compound pages cannot be used for the page cache if we do not
+ * have enough flags. So we can use the dirty flag for virtually
+ * mapped compound pages.
+ */
+__PAGEFLAG(Vcompound, dirty)
+
 #endif	/* PAGE_FLAGS_H */