HWPOISON, hugetlb: add free check to dequeue_hwpoison_huge_page()

This check is necessary to avoid race between dequeue and allocation,
which can cause a free hugepage to be dequeued twice and get kernel unstable.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 9e51f77d44ca..796f30e00806 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -43,7 +43,7 @@ int hugetlb_reserve_pages(struct inode *inode, long from, long to,
                                                 struct vm_area_struct *vma,
                                                 int acctflags);
 void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed);
-void __isolate_hwpoisoned_huge_page(struct page *page);
+int dequeue_hwpoisoned_huge_page(struct page *page);
 void copy_huge_page(struct page *dst, struct page *src);
 
 extern unsigned long hugepages_treat_as_movable;
@@ -102,7 +102,7 @@ static inline void hugetlb_report_meminfo(struct seq_file *m)
 #define hugetlb_free_pgd_range(tlb, addr, end, floor, ceiling) ({BUG(); 0; })
 #define hugetlb_fault(mm, vma, addr, flags)     ({ BUG(); 0; })
 #define huge_pte_offset(mm, address)    0
-#define __isolate_hwpoisoned_huge_page(page)    0
+#define dequeue_hwpoisoned_huge_page(page)      0
 static inline void copy_huge_page(struct page *dst, struct page *src)
 {
 }