ovl: add helper to force data copy-up

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

fs/overlayfs/copy_up.c

@@ -867,6 +867,11 @@ int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags)
 	return err;
 }
 
+int ovl_copy_up_with_data(struct dentry *dentry)
+{
+	return ovl_copy_up_flags(dentry, O_WRONLY);
+}
+
 int ovl_copy_up(struct dentry *dentry)
 {
 	return ovl_copy_up_flags(dentry, 0);

fs/overlayfs/overlayfs.h

@@ -407,6 +407,7 @@ extern const struct file_operations ovl_file_operations;
 
 /* copy_up.c */
 int ovl_copy_up(struct dentry *dentry);
+int ovl_copy_up_with_data(struct dentry *dentry);
 int ovl_copy_up_flags(struct dentry *dentry, int flags);
 int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags);
 int ovl_copy_xattr(struct dentry *old, struct dentry *new);