From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:58416 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754383AbeDIUDa (ORCPT ); Mon, 9 Apr 2018 16:03:30 -0400 Subject: Patch "lockd: fix lockd shutdown race" has been added to the 4.9-stable tree To: bfields@redhat.com, alexander.levin@microsoft.com, djeffery@redhat.com, gregkh@linuxfoundation.org Cc: , From: Date: Mon, 09 Apr 2018 21:58:36 +0200 Message-ID: <1523303916123216@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled lockd: fix lockd shutdown race to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: lockd-fix-lockd-shutdown-race.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Mon Apr 9 17:09:24 CEST 2018 From: "J. Bruce Fields" Date: Tue, 28 Mar 2017 21:25:08 -0400 Subject: lockd: fix lockd shutdown race From: "J. Bruce Fields" [ Upstream commit efda760fe95ea15291853c8fa9235c32d319cd98 ] As reported by David Jeffery: "a signal was sent to lockd while lockd was shutting down from a request to stop nfs. The signal causes lockd to call restart_grace() which puts the lockd_net structure on the grace list. If this signal is received at the wrong time, it will occur after lockd_down_net() has called locks_end_grace() but before lockd_down_net() stops the lockd thread. This leads to lockd putting the lockd_net structure back on the grace list, then exiting without anything removing it from the list." So, perform the final locks_end_grace() from the the lockd thread; this ensures it's serialized with respect to restart_grace(). Reported-by: David Jeffery Signed-off-by: J. Bruce Fields Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- fs/lockd/svc.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/fs/lockd/svc.c +++ b/fs/lockd/svc.c @@ -132,6 +132,8 @@ lockd(void *vrqstp) { int err = 0; struct svc_rqst *rqstp = vrqstp; + struct net *net = &init_net; + struct lockd_net *ln = net_generic(net, lockd_net_id); /* try_to_freeze() is called from svc_recv() */ set_freezable(); @@ -176,6 +178,8 @@ lockd(void *vrqstp) if (nlmsvc_ops) nlmsvc_invalidate_all(); nlm_shutdown_hosts(); + cancel_delayed_work_sync(&ln->grace_period_end); + locks_end_grace(&ln->lockd_manager); return 0; } @@ -270,8 +274,6 @@ static void lockd_down_net(struct svc_se if (ln->nlmsvc_users) { if (--ln->nlmsvc_users == 0) { nlm_shutdown_hosts_net(net); - cancel_delayed_work_sync(&ln->grace_period_end); - locks_end_grace(&ln->lockd_manager); svc_shutdown_net(serv, net); dprintk("lockd_down_net: per-net data destroyed; net=%p\n", net); } Patches currently in stable-queue which might be from bfields@redhat.com are queue-4.9/lockd-fix-lockd-shutdown-race.patch