diff options
| author | J. Bruce Fields <bfields@redhat.com> | 2017-03-28 21:25:08 -0400 |
|---|---|---|
| committer | J. Bruce Fields <bfields@redhat.com> | 2017-05-08 18:06:18 -0400 |
| commit | efda760fe95ea15291853c8fa9235c32d319cd98 (patch) | |
| tree | 2769a42950ce9704f3a3c7b9fd9a61b4426d7d30 | |
| parent | ed6473ddc704a2005b9900ca08e236ebb2d8540a (diff) | |
| download | linux-efda760fe95ea15291853c8fa9235c32d319cd98.tar.bz2 | |
lockd: fix lockd shutdown race
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>
| -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 e7c8b9c76e48..5d481e8a1b5d 100644 --- 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_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); } |