Author: Julia Lawall <Julia.Lawall@lip6.fr> Just use WARN_ON rather than an if containing only WARN_ON(1). A simplified version of the semantic patch that makes this transformation is as follows: (http://coccinelle.lip6.fr/) // @@ expression e; @@ – if (e) WARN_ON(1); + WARN_ON(e); // Signed-off-by: Julia Lawall Reviewed-by: David Sterba Signed-off-by: Chris Mason — fs/btrfs/backref.c | 3 +– …