From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755451AbYIAIvi (ORCPT ); Mon, 1 Sep 2008 04:51:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752220AbYIAIva (ORCPT ); Mon, 1 Sep 2008 04:51:30 -0400 Received: from mgw1.diku.dk ([130.225.96.91]:39012 "EHLO mgw1.diku.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751728AbYIAIv3 (ORCPT ); Mon, 1 Sep 2008 04:51:29 -0400 From: Julien Brunel To: swhiteho@redhat.com, cluster-devel@redhat.com, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: [PATCH] fs/gfs2: Use an IS_ERR test rather than a NULL test Date: Mon, 1 Sep 2008 10:51:22 +0200 User-Agent: KMail/1.9.9 MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200809011051.22862.brunel@diku.dk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Julien Brunel In case of error, the function gfs2_inode_lookup returns an ERR pointer, but never returns a NULL pointer. So a NULL test that necessarily comes after an IS_ERR test should be deleted, and a NULL test that may come after a call to this function should be strengthened by an IS_ERR test. The semantic match that finds this problem is as follows: (http://www.emn.fr/x-info/coccinelle/) // @match_bad_null_test@ expression x, E; statement S1,S2; @@ x = gfs2_inode_lookup(...) ... when != x = E * if (x != NULL) S1 else S2 // Signed-off-by: Julien Brunel Signed-off-by: Julia Lawall --- fs/gfs2/inode.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff -u -p a/fs/gfs2/inode.c b/fs/gfs2/inode.c --- a/fs/gfs2/inode.c +++ b/fs/gfs2/inode.c @@ -1033,13 +1033,11 @@ struct inode *gfs2_createi(struct gfs2_h if (bh) brelse(bh); - if (!inode) - return ERR_PTR(-ENOMEM); return inode; fail_gunlock2: gfs2_glock_dq_uninit(ghs + 1); - if (inode) + if (inode && !IS_ERR(inode)) iput(inode); fail_gunlock: gfs2_glock_dq(ghs);