From cb7d224f82e41d82518e7f9ea271d215d4d08e6e Mon Sep 17 00:00:00 2001
From: Scott Mayhew <smayhew@redhat.com>
Date: Thu, 30 Jun 2016 10:39:32 -0400
Subject: [PATCH] lockd: unregister notifier blocks if the service fails to
 come up completely

If the lockd service fails to start up then we need to be sure that the
notifier blocks are not registered, otherwise a subsequent start of the
service could cause the same notifier to be registered twice, leading to
soft lockups.

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 0751ddf77b6a "lockd: Register callbacks on the inetaddr_chain..."
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 fs/lockd/svc.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 154a107cd3762..fc4084ef4736d 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -335,12 +335,17 @@ static struct notifier_block lockd_inet6addr_notifier = {
 };
 #endif
 
-static void lockd_svc_exit_thread(void)
+static void lockd_unregister_notifiers(void)
 {
 	unregister_inetaddr_notifier(&lockd_inetaddr_notifier);
 #if IS_ENABLED(CONFIG_IPV6)
 	unregister_inet6addr_notifier(&lockd_inet6addr_notifier);
 #endif
+}
+
+static void lockd_svc_exit_thread(void)
+{
+	lockd_unregister_notifiers();
 	svc_exit_thread(nlmsvc_rqst);
 }
 
@@ -462,7 +467,7 @@ int lockd_up(struct net *net)
 	 * Note: svc_serv structures have an initial use count of 1,
 	 * so we exit through here on both success and failure.
 	 */
-err_net:
+err_put:
 	svc_destroy(serv);
 err_create:
 	mutex_unlock(&nlmsvc_mutex);
@@ -470,7 +475,9 @@ int lockd_up(struct net *net)
 
 err_start:
 	lockd_down_net(serv, net);
-	goto err_net;
+err_net:
+	lockd_unregister_notifiers();
+	goto err_put;
 }
 EXPORT_SYMBOL_GPL(lockd_up);
 
-- 
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