1 files changed, 13 insertions, 0 deletions

diff --git a/include/linux/dax.h b/include/linux/dax.h
index deb0f663252f..450b28db9533 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -88,6 +88,8 @@ int dax_writeback_mapping_range(struct address_space *mapping,
                 struct block_device *bdev, struct writeback_control *wbc);
 
 struct page *dax_layout_busy_page(struct address_space *mapping);
+bool dax_lock_mapping_entry(struct page *page);
+void dax_unlock_mapping_entry(struct page *page);
 #else
 static inline bool bdev_dax_supported(struct block_device *bdev,
                 int blocksize)
@@ -119,6 +121,17 @@ static inline int dax_writeback_mapping_range(struct address_space *mapping,
 {
         return -EOPNOTSUPP;
 }
+
+static inline bool dax_lock_mapping_entry(struct page *page)
+{
+        if (IS_DAX(page->mapping->host))
+                return true;
+        return false;
+}
+
+static inline void dax_unlock_mapping_entry(struct page *page)
+{
+}
 #endif
 
 int dax_read_lock(void);