Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752410AbdFGXCt (ORCPT ); Wed, 7 Jun 2017 19:02:49 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:50231 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752297AbdFGXCr (ORCPT ); Wed, 7 Jun 2017 19:02:47 -0400 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: NeilBrown , Trond Myklebust , Willy Tarreau Subject: [PATCH 3.10 089/250] NFSv4.1: nfs4_fl_prepare_ds must be careful about reporting success. Date: Thu, 8 Jun 2017 00:57:55 +0200 Message-Id: <1496876436-32402-90-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1496876436-32402-1-git-send-email-w@1wt.eu> References: <1496876436-32402-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1401 Lines: 40 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: Willy Tarreau --- fs/nfs/nfs4filelayoutdev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/nfs/nfs4filelayoutdev.c b/fs/nfs/nfs4filelayoutdev.c index 678cb89..b906d8e 100644 --- a/fs/nfs/nfs4filelayoutdev.c +++ b/fs/nfs/nfs4filelayoutdev.c @@ -821,7 +821,8 @@ nfs4_fl_prepare_ds(struct pnfs_layout_segment *lseg, u32 ds_idx) 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; -- 2.8.0.rc2.1.gbe9624a