mm: close PageTail race

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / linux / huge_mm.h

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 528454c2caa91b17cbb5761de006418909de2046..a193bb3e4138f006dea22ade54eea7192d2cc7f6 100644 (file)
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -159,23 +159,6 @@ static inline int hpage_nr_pages(struct page *page)
                return HPAGE_PMD_NR;
        return 1;
 }
-static inline struct page *compound_trans_head(struct page *page)
-{
-       if (PageTail(page)) {
-               struct page *head;
-               head = page->first_page;
-               smp_rmb();
-               /*
-                * head may be a dangling pointer.
-                * __split_huge_page_refcount clears PageTail before
-                * overwriting first_page, so if PageTail is still
-                * there it means the head pointer isn't dangling.
-                */
-               if (PageTail(page))
-                       return head;
-       }
-       return page;
-}
 
 extern int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
                                unsigned long addr, pmd_t pmd, pmd_t *pmdp);
@@ -205,7 +188,6 @@ static inline int split_huge_page(struct page *page)
        do { } while (0)
 #define split_huge_page_pmd_mm(__mm, __address, __pmd) \
        do { } while (0)
-#define compound_trans_head(page) compound_head(page)
 static inline int hugepage_madvise(struct vm_area_struct *vma,
                                   unsigned long *vm_flags, int advice)
 {