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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 8ABCAC433C1 for ; Tue, 30 Mar 2021 16:54:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5576961994 for ; Tue, 30 Mar 2021 16:54:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232349AbhC3QyZ (ORCPT ); Tue, 30 Mar 2021 12:54:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:59708 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232319AbhC3Qxw (ORCPT ); Tue, 30 Mar 2021 12:53:52 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1B34061928; Tue, 30 Mar 2021 16:53:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1617123232; bh=wHyokMBJExOMFMnfOGwIISS5+NEOWdUEUjgRLC3woag=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=dg+5iaUKD6r7xXO2ISLNafmBg44m8xKvzCEg5/DaE+YnMqvbEBWbjMMpDoYMpgEdi w+s9wnojv9ATjtq3C17FLLAO3718KxuG///5M4PhnHEYv8EWUPfvFn0ml3ZtJUaVDj IGvVACOALztEkSRsBbIQzpBHlrpZtmqOwbdtokD4TW8sinnjjo1jjuXqk94Wl7MiSJ H091DMNSW9s5w4KY5Q9zIwviRveI+kYouGNv6TlaZPu+dqSt4anSh0iwMFqVGxHgKo wbDCzCYFakN4NfLM8zO5fcruZs/fflUm1a4IvtO+rbUhOTr4Rw90w71EHKlKofWjES cWtQUOtcB1Gsw== Message-ID: Subject: Re: [PATCH] ceph: fix inode leak on getattr error in __fh_to_dentry From: Jeff Layton To: Luis Henriques Cc: ceph-devel@vger.kernel.org, idryomov@gmail.com Date: Tue, 30 Mar 2021 12:53:51 -0400 In-Reply-To: References: <20210326154032.86410-1-jlayton@kernel.org> Content-Type: text/plain; charset="ISO-8859-15" User-Agent: Evolution 3.38.4 (3.38.4-1.fc33) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org 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. -- Jeff Layton