diff --git a/fs/attr.c b/fs/attr.c
index 0da9095..29e38a1 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -171,6 +171,8 @@
 	struct timespec now;
 	unsigned int ia_valid = attr->ia_valid;
 
+	WARN_ON_ONCE(!mutex_is_locked(&inode->i_mutex));
+
 	if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | ATTR_TIMES_SET)) {
 		if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
 			return -EPERM;
@@ -250,5 +252,4 @@
 
 	return error;
 }
-
 EXPORT_SYMBOL(notify_change);