1 files changed, 17 insertions, 0 deletions

diff --git a/fs/dax.c b/fs/dax.c
index ed1619ec6537..d0bd1f4f81b3 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -464,6 +464,23 @@ int dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf,
 EXPORT_SYMBOL_GPL(dax_fault);
 
 /**
+ * dax_pfn_mkwrite - handle first write to DAX page
+ * @vma: The virtual memory area where the fault occurred
+ * @vmf: The description of the fault
+ *
+ */
+int dax_pfn_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+        struct super_block *sb = file_inode(vma->vm_file)->i_sb;
+
+        sb_start_pagefault(sb);
+        file_update_time(vma->vm_file);
+        sb_end_pagefault(sb);
+        return VM_FAULT_NOPAGE;
+}
+EXPORT_SYMBOL_GPL(dax_pfn_mkwrite);
+
+/**
  * dax_zero_page_range - zero a range within a page of a DAX file
  * @inode: The file being truncated
  * @from: The file offset that is being truncated to