From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751233AbWGKMEa (ORCPT ); Tue, 11 Jul 2006 08:04:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751234AbWGKMEa (ORCPT ); Tue, 11 Jul 2006 08:04:30 -0400 Received: from pat.uio.no ([129.240.10.4]:29096 "EHLO pat.uio.no") by vger.kernel.org with ESMTP id S1751233AbWGKME3 (ORCPT ); Tue, 11 Jul 2006 08:04:29 -0400 Subject: Re: [PATCH] struct file leakage From: Trond Myklebust To: Andrew Morton Cc: Kirill Korotaev , linux-kernel@vger.kernel.org, kuznet@ms2.inr.ac.ru, devel@openvz.org In-Reply-To: <20060710030526.fdb1ca27.akpm@osdl.org> References: <44B2185F.1060402@sw.ru> <20060710030526.fdb1ca27.akpm@osdl.org> Content-Type: text/plain Date: Tue, 11 Jul 2006 08:04:06 -0400 Message-Id: <1152619446.5745.16.camel@lade.trondhjem.org> Mime-Version: 1.0 X-Mailer: Evolution 2.6.1 Content-Transfer-Encoding: 7bit X-UiO-Spam-info: not spam, SpamAssassin (score=-3.125, required 12, autolearn=disabled, AWL 1.88, UIO_MAIL_IS_INTERNAL -5.00) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2006-07-10 at 03:05 -0700, Andrew Morton wrote: > On Mon, 10 Jul 2006 13:05:35 +0400 > Kirill Korotaev wrote: > > > Hello! > > > > Andrew, this is a patch from Alexey Kuznetsov for 2.6.16. > > I believe 2.6.17 still has this leak. > > > > ------------------------------------------------------------- > > > > 2.6.16 leaks like hell. While testing, I found massive leakage > > (reproduced in openvz) in: > > > > *filp > > *size-4096 > > > > And 1 object leaks in > > *size-32 > > *size-64 > > *size-128 > > > > > > It is the fix for the first one. filp leaks in the bowels > > of namei.c. > > > > Seems, size-4096 is file table leaking in expand_fdtables. > > I suspect that's been there for a long time. > > > I have no idea what are the rest and why they show only > > accompaniing another leaks. Some debugging structs? > > I don't understand this. Are you implying that there are other bugs. > > > Signed-Off-By: Alexey Kuznetsov > > CC: Kirill Korotaev > > > > > --- linux-2.6.16-w/fs/namei.c 2006-07-10 11:43:11.000000000 +0400 > > +++ linux-2.6.16/fs/namei.c 2006-07-10 11:53:36.000000000 +0400 > > @@ -1774,8 +1774,15 @@ do_link: > > if (error) > > goto exit_dput; > > error = __do_follow_link(&path, nd); > > - if (error) > > + if (error) { > > + /* Does someone understand code flow here? Or it is only > > + * me so stupid? Anathema to whoever designed this non-sense > > + * with "intent.open". > > + */ > > + if (!IS_ERR(nd->intent.open.file)) > > + release_open_intent(nd); > > return error; > > + } > > nd->flags &= ~LOOKUP_PARENT; > > if (nd->last_type == LAST_BIND) > > goto ok; > > > > It's good to have some more Alexeycomments in the tree. > > I wonder if we're also needing a path_release() here. And if not, whether > it is still safe to run release_open_intent() against this nameidata? > > Hopefully Trond can recall what's going on in there... The patch looks correct, except that I believe we can skip the IS_ERR() test there: if we're following links then we presumably have not tried to open any files yet, so the call to release_open_intent(nd) can be made unconditional. Cheers, Trond