Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965180AbdCJMZ3 (ORCPT ); Fri, 10 Mar 2017 07:25:29 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:45314 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965156AbdCJMZZ (ORCPT ); Fri, 10 Mar 2017 07:25:25 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Adamson, Andy" , "Trond Myklebust" , "Olga Kornievskaia" , "NeilBrown" Date: Fri, 10 Mar 2017 11:46:22 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 119/370] NFSv4.1: nfs4_fl_prepare_ds must be careful about reporting success. In-Reply-To: X-SA-Exim-Connect-IP: 82.70.136.246 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1383 Lines: 40 3.16.42-rc1 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: Ben Hutchings --- 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 @@ -827,7 +827,8 @@ nfs4_fl_prepare_ds(struct pnfs_layout_se nfs4_wait_ds_connect(ds); } out_test_devid: - if (filelayout_test_devid_unavailable(devid)) + if (ret->ds_clp == NULL || + filelayout_test_devid_unavailable(devid)) ret = NULL; out: return ret;