diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c
index 2324262..f1fb0a2 100644
--- a/fs/cachefiles/interface.c
+++ b/fs/cachefiles/interface.c
@@ -446,7 +446,7 @@
 		return 0;
 
 	cachefiles_begin_secure(cache, &saved_cred);
-	mutex_lock(&object->backer->d_inode->i_mutex);
+	mutex_lock(&d_inode(object->backer)->i_mutex);
 
 	/* if there's an extension to a partial page at the end of the backing
 	 * file, we need to discard the partial page so that we pick up new
@@ -465,7 +465,7 @@
 	ret = notify_change(object->backer, &newattrs, NULL);
 
 truncate_failed:
-	mutex_unlock(&object->backer->d_inode->i_mutex);
+	mutex_unlock(&d_inode(object->backer)->i_mutex);
 	cachefiles_end_secure(cache, saved_cred);
 
 	if (ret == -EIO) {