From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Trond Myklebust Subject: [PATCH 4.11 187/197] NFSv4: Fix a hang in OPEN related to server reboot Date: Tue, 23 May 2017 22:09:08 +0200 Message-Id: <20170523200840.102439136@linuxfoundation.org> In-Reply-To: <20170523200821.666872592@linuxfoundation.org> References: <20170523200821.666872592@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Trond Myklebust commit 56e0d71ef12f026d96213e45a662bde6bbff4676 upstream. 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...") Signed-off-by: Greg Kroah-Hartman --- fs/nfs/nfs4proc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -2300,8 +2300,10 @@ static int _nfs4_proc_open(struct nfs4_o 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; }