From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
We need to check the page is initialised before we call compound_head()
on it, or we'll be checking whether the page at -2 has been initialised.
Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
---
include/linux/page-flags.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index a6931046cc5c..c74b880a1b85 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -186,13 +186,13 @@ static __always_inline struct page *CheckPageInit(struct page *page)
* The page flag is not used for compound pages.
*/
#define PF_ANY(page, modify) CheckPageInit(page)
-#define PF_HEAD(page, modify) CheckPageInit(compound_head(page))
+#define PF_HEAD(page, modify) compound_head(CheckPageInit(page))
#define PF_ONLY_HEAD(page, modify) ({ \
VM_BUG_ON_PGFLAGS(PageTail(page), page); \
CheckPageInit(page); })
#define PF_TAIL_READ(page, modify) ({ \
VM_BUG_ON_PGFLAGS(modify && PageTail(page), page); \
- CheckPageInit(compound_head(page)); })
+ compound_head(CheckPageInit(page)); })
#define PF_NO_COMPOUND(page, modify) ({ \
VM_BUG_ON_PGFLAGS(modify && PageCompound(page), page); \
CheckPageInit(page); })
--
2.16.3
