From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D1E68C433E6 for ; Wed, 31 Mar 2021 09:52:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AAD87619B9 for ; Wed, 31 Mar 2021 09:52:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234776AbhCaJwN (ORCPT ); Wed, 31 Mar 2021 05:52:13 -0400 Received: from mx2.suse.de ([195.135.220.15]:46614 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234800AbhCaJwH (ORCPT ); Wed, 31 Mar 2021 05:52:07 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id AE7ACAF13; Wed, 31 Mar 2021 09:52:03 +0000 (UTC) Received: from localhost (brahms [local]) by brahms (OpenSMTPD) with ESMTPA id ded4d69c; Wed, 31 Mar 2021 09:53:24 +0000 (UTC) Date: Wed, 31 Mar 2021 10:53:24 +0100 From: Luis Henriques To: Jeff Layton Cc: ceph-devel@vger.kernel.org, idryomov@gmail.com Subject: Re: [PATCH] ceph: fix inode leak on getattr error in __fh_to_dentry Message-ID: References: <20210326154032.86410-1-jlayton@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org On Tue, Mar 30, 2021 at 12:53:51PM -0400, Jeff Layton wrote: > On Tue, 2021-03-30 at 14:46 +0100, Luis Henriques wrote: > > On Fri, Mar 26, 2021 at 11:40:32AM -0400, Jeff Layton wrote: > > > Cc: Luis Henriques > > > Fixes: 878dabb64117 (ceph: don't return -ESTALE if there's still an open file) > > > Signed-off-by: Jeff Layton > > > --- > > > fs/ceph/export.c | 4 +++- > > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > > > diff --git a/fs/ceph/export.c b/fs/ceph/export.c > > > index f22156ee7306..17d8c8f4ec89 100644 > > > --- a/fs/ceph/export.c > > > +++ b/fs/ceph/export.c > > > @@ -178,8 +178,10 @@ static struct dentry *__fh_to_dentry(struct super_block *sb, u64 ino) > > > return ERR_CAST(inode); > > > /* We need LINK caps to reliably check i_nlink */ > > > err = ceph_do_getattr(inode, CEPH_CAP_LINK_SHARED, false); > > > - if (err) > > > + if (err) { > > > + iput(inode); > > > > To be honest, I'm failing to see where we could be leaking the inode here. > > We're trying to get LINK caps to do the check bellow; if ceph_do_getattr() > > fails, the inode reference it (may) grabs will be released by calling > > ceph_mdsc_put_request(). > > > > Do you see any other possibility? > > > > We already hold a reference to the inode at this point by virtue of the > successful return from __lookup_inode. ceph_do_getattr does not consume > that reference on success or failure, AFAICT. Doh! Of course. I was looking at it the wrong way. Cheers, -- Luís