Return-Path: Received: from mail-io0-f193.google.com ([209.85.223.193]:35398 "EHLO mail-io0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S945615AbdDTSmF (ORCPT ); Thu, 20 Apr 2017 14:42:05 -0400 Received: by mail-io0-f193.google.com with SMTP id d203so19401005iof.2 for ; Thu, 20 Apr 2017 11:42:04 -0700 (PDT) From: Trond Myklebust To: linux-nfs@vger.kernel.org Subject: [PATCH] NFSv4: Fix a hang in OPEN related to server reboot Date: Thu, 20 Apr 2017 14:41:59 -0400 Message-Id: <20170420184159.125268-1-trond.myklebust@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: If the server fails to return the attributes as part of an OPEN reply, and then reboots, we can end up hanging. The reason is that the client attempts to send a GETATTR in order to pick up the missing OPEN call, but fails to release the slot first, causing reboot recovery to deadlock. Signed-off-by: Trond Myklebust Fixes: 2e80dbe7ac51a ("NFSv4.1: Close callback races for OPEN, LAYOUTGET...") Cc: stable@vger.kernel.org # v4.8+ --- fs/nfs/nfs4proc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 4e52ac773d1f..6e9ff2d9a5bf 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -2300,8 +2300,10 @@ static int _nfs4_proc_open(struct nfs4_opendata *data) if (status != 0) return status; } - if (!(o_res->f_attr->valid & NFS_ATTR_FATTR)) + if (!(o_res->f_attr->valid & NFS_ATTR_FATTR)) { + nfs4_sequence_free_slot(&o_res->seq_res); nfs4_proc_getattr(server, &o_res->fh, o_res->f_attr, o_res->f_label); + } return 0; } -- 2.9.3