From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754860AbdARLLC (ORCPT ); Wed, 18 Jan 2017 06:11:02 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:41200 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754290AbdARLIb (ORCPT ); Wed, 18 Jan 2017 06:08:31 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, NeilBrown , Olga Kornievskaia , "Adamson, Andy" , Trond Myklebust Subject: [PATCH 4.9 091/120] NFSv4.1: nfs4_fl_prepare_ds must be careful about reporting success. Date: Wed, 18 Jan 2017 11:46:49 +0100 Message-Id: <20170118104651.836441787@linuxfoundation.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170118104648.120216880@linuxfoundation.org> References: <20170118104648.120216880@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: NeilBrown commit cfd278c280f997cf2fe4662e0acab0fe465f637b upstream. Various places assume that if nfs4_fl_prepare_ds() turns a non-NULL 'ds', then ds->ds_clp will also be non-NULL. This is not necessasrily true in the case when the process received a fatal signal while nfs4_pnfs_ds_connect is waiting in nfs4_wait_ds_connect(). In that case ->ds_clp may not be set, and the devid may not recently have been marked unavailable. So add a test for ds_clp == NULL and return NULL in that case. Fixes: c23266d532b4 ("NFS4.1 Fix data server connection race") Signed-off-by: NeilBrown Acked-by: Olga Kornievskaia Acked-by: Adamson, Andy Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman --- fs/nfs/filelayout/filelayoutdev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/nfs/filelayout/filelayoutdev.c +++ b/fs/nfs/filelayout/filelayoutdev.c @@ -283,7 +283,8 @@ nfs4_fl_prepare_ds(struct pnfs_layout_se s->nfs_client->cl_rpcclient->cl_auth->au_flavor); out_test_devid: - if (filelayout_test_devid_unavailable(devid)) + if (ret->ds_clp == NULL || + filelayout_test_devid_unavailable(devid)) ret = NULL; out: return ret;