1 files changed, 17 insertions, 0 deletions

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 1b921299abc4..f56cacb4fec3 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -113,6 +113,18 @@ extern void __vma_adjust_trans_huge(struct vm_area_struct *vma,
                                     unsigned long start,
                                     unsigned long end,
                                     long adjust_next);
+extern int __pmd_trans_huge_lock(pmd_t *pmd,
+                                 struct vm_area_struct *vma);
+/* mmap_sem must be held on entry */
+static inline int pmd_trans_huge_lock(pmd_t *pmd,
+                                      struct vm_area_struct *vma)
+{
+        VM_BUG_ON(!rwsem_is_locked(&vma->vm_mm->mmap_sem));
+        if (pmd_trans_huge(*pmd))
+                return __pmd_trans_huge_lock(pmd, vma);
+        else
+                return 0;
+}
 static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
                                          unsigned long start,
                                          unsigned long end,
@@ -176,6 +188,11 @@ static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
                                          long adjust_next)
 {
 }
+static inline int pmd_trans_huge_lock(pmd_t *pmd,
+                                      struct vm_area_struct *vma)
+{
+        return 0;
+}
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 #endif /* _LINUX_HUGE_MM_H */