Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757877Ab1F2VSk (ORCPT ); Wed, 29 Jun 2011 17:18:40 -0400 Received: from swampdragon.chaosbits.net ([90.184.90.115]:19068 "EHLO swampdragon.chaosbits.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751199Ab1F2VSh (ORCPT ); Wed, 29 Jun 2011 17:18:37 -0400 Date: Wed, 29 Jun 2011 23:09:27 +0200 (CEST) From: Jesper Juhl To: linux-kernel@vger.kernel.org cc: cluster-devel@redhat.com, David Teigland , Christine Caulfield Subject: [PATCH] fs, dlm: Don't leak, don't do pointless NULL checks and use kzalloc Message-ID: User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2213 Lines: 67 In fs/dlm/lock.c in the dlm_scan_waiters() function there are 3 small issues: 1) first time through the loop we allocate memory for 'warned', if we then (in the loop) don't take the "if (!warned)" path and loop again, the second time through the loop we'll allocate memory again and store it to 'warned' without freeing the previous allocation - this leaks memory. Fix this by kfree'ing 'warned' just before the in-loop allocation. The first time through the loop this will result in a pointless kfree(NULL), but that's a small price to pay for avoiding a mem leak IMHO. 2) There's no need to test the return value of the allocation and do a memset if is succeedes. Just use kzalloc() to obtain zeroed memory. 3) Since kfree() handles NULL pointers gracefully, the test of 'warned' against NULL before the kfree() after the loop is completely pointless. Remove it. Signed-off-by: Jesper Juhl --- fs/dlm/lock.c | 9 +++------ 1 files changed, 3 insertions(+), 6 deletions(-) compile tested only. diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c index f71d0b5..a18ecff 100644 --- a/fs/dlm/lock.c +++ b/fs/dlm/lock.c @@ -849,9 +849,8 @@ void dlm_scan_waiters(struct dlm_ls *ls) if (!num_nodes) { num_nodes = ls->ls_num_nodes; - warned = kmalloc(GFP_KERNEL, num_nodes * sizeof(int)); - if (warned) - memset(warned, 0, num_nodes * sizeof(int)); + kfree(warned); + warned = kzalloc(GFP_KERNEL, num_nodes * sizeof(int)); } if (!warned) continue; @@ -863,9 +862,7 @@ void dlm_scan_waiters(struct dlm_ls *ls) dlm_config.ci_waitwarn_us, lkb->lkb_wait_nodeid); } mutex_unlock(&ls->ls_waiters_mutex); - - if (warned) - kfree(warned); + kfree(warned); if (debug_expired) log_debug(ls, "scan_waiters %u warn %u over %d us max %lld us", -- 1.7.6 -- Jesper Juhl http://www.chaosbits.net/ Don't top-post http://www.catb.org/jargon/html/T/top-post.html Plain text mails only, please. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/