diff options
| author | J. Bruce Fields <bfields@redhat.com> | 2017-03-28 21:25:08 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-04-13 19:50:02 +0200 |
| commit | f1d74fa2dbb1d447fd62de91872cff5a4d5b442a (patch) | |
| tree | 56ae37c05038f072d55c4bb2827f77405f23678a /fs | |
| parent | 246db5901f4a7f0823a37ff0aa4237813bf44e81 (diff) | |
lockd: fix lockd shutdown race
[ 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 <djeffery@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/lockd/svc.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c index 5f31ebd96c06..a2edb0049eb5 100644 --- a/fs/lockd/svc.c +++ b/fs/lockd/svc.c @@ -129,6 +129,8 @@ 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(); @@ -173,6 +175,8 @@ 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; } @@ -267,8 +271,6 @@ static void lockd_down_net(struct svc_serv *serv, struct net *net) 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); } |