From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751268AbdAaFsQ (ORCPT ); Tue, 31 Jan 2017 00:48:16 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:60288 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751337AbdAaFjp (ORCPT ); Tue, 31 Jan 2017 00:39:45 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Trond Myklebust Subject: [PATCH 4.9 39/66] NFSv4.1: Fix a deadlock in layoutget Date: Tue, 31 Jan 2017 06:36:43 +0100 Message-Id: <20170131053604.804187207@linuxfoundation.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170131053603.098140622@linuxfoundation.org> References: <20170131053603.098140622@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: Trond Myklebust commit 8ac092519ad91931c96d306c4bfae2c6587c325f upstream. We cannot call nfs4_handle_exception() without first ensuring that the slot has been freed. If not, we end up deadlocking with the process waiting for recovery to complete, and recovery waiting for the slot table to drain. Fixes: 2e80dbe7ac51 ("NFSv4.1: Close callback races for OPEN, LAYOUTGET...") Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman --- fs/nfs/nfs4proc.c | 1 + 1 file changed, 1 insertion(+) --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -8371,6 +8371,7 @@ nfs4_layoutget_handle_exception(struct r goto out; } + nfs4_sequence_free_slot(&lgp->res.seq_res); err = nfs4_handle_exception(server, nfs4err, exception); if (!status) { if (exception->retry)