From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753500AbZCIJfD (ORCPT ); Mon, 9 Mar 2009 05:35:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752118AbZCIJew (ORCPT ); Mon, 9 Mar 2009 05:34:52 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:54151 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752083AbZCIJev (ORCPT ); Mon, 9 Mar 2009 05:34:51 -0400 Message-ID: <49B4E2BA.3030809@cn.fujitsu.com> Date: Mon, 09 Mar 2009 17:34:50 +0800 From: Li Zefan User-Agent: Thunderbird 2.0.0.9 (X11/20071115) MIME-Version: 1.0 To: Jens Axboe CC: LKML , martin.petersen@oracle.com Subject: Re: [PATCH] block: fix memory leak in bio_clone() References: <49B4DD9C.5030902@cn.fujitsu.com> <20090309092407.GI11787@kernel.dk> In-Reply-To: <20090309092407.GI11787@kernel.dk> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jens Axboe wrote: > On Mon, Mar 09 2009, Li Zefan wrote: >> If bio_integrity_clone() fails, bio_clone() returns NULL without freeing >> the newly allocated bio. >> >> Signed-off-by: Li Zefan >> --- >> fs/bio.c | 4 +++- >> 1 files changed, 3 insertions(+), 1 deletions(-) >> >> diff --git a/fs/bio.c b/fs/bio.c >> index 124b95c..896330e 100644 >> --- a/fs/bio.c >> +++ b/fs/bio.c >> @@ -465,8 +465,10 @@ struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask) >> >> ret = bio_integrity_clone(b, bio, fs_bio_set); >> >> - if (ret < 0) >> + if (ret < 0) { >> + bio_put(bio); >> return NULL; >> + } >> } >> >> return b; >> -- 1.5.4.rc3 > > Good spotting. But it looks like there are actually several problems > there. bio_integrity_clone() is mempool backed. Currently that ret < 0 > can never trigger, since bio_integrity_clone() has hard-wired __GFP_WAIT Do you mean GFP_NOIO? > as the mempool mask. So the leak will not occur, but it does mean that > it isn't honoring the gfp_mask passed in to bio_clone(), which is the I noticed there was a patch to do this, and seems you planed to merge it into .29? "[PATCH] Add gfp_mask to bio_integrity_clone()" http://lkml.org/lkml/2008/10/30/11 > first bug. The second bug is that it should be using its own bioset, as > it is illegal to do multiple __GFP_WAIT allocations on a single mempool > and always expect progress. >