From: Ursula Braun <ubraun@linux.ibm.com>
Date: Sat, 16 Nov 2019 17:47:30 +0100
Subject: net/smc: guarantee removal of link groups in reboot
Git-commit: a33a803cfe64309d330540ae4a8df17158bcb6ea
Patch-mainline: v5.5-rc1
References: jsc#SLE-7395

When rebooting it should be guaranteed all link groups are cleaned
up and freed.

Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 net/smc/smc_core.c |   16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -14,6 +14,7 @@
 #include <linux/random.h>
 #include <linux/workqueue.h>
 #include <linux/wait.h>
+#include <linux/reboot.h>
 #include <net/tcp.h>
 #include <net/sock.h>
 #include <rdma/ib_verbs.h>
@@ -1282,14 +1283,27 @@ static void smc_lgrs_shutdown(void)
 	spin_unlock(&smcd_dev_list.lock);
 }
 
+static int smc_core_reboot_event(struct notifier_block *this,
+				 unsigned long event, void *ptr)
+{
+	smc_lgrs_shutdown();
+
+	return 0;
+}
+
+static struct notifier_block smc_reboot_notifier = {
+	.notifier_call = smc_core_reboot_event,
+};
+
 int __init smc_core_init(void)
 {
 	atomic_set(&lgr_cnt, 0);
-	return 0;
+	return register_reboot_notifier(&smc_reboot_notifier);
 }
 
 /* Called (from smc_exit) when module is removed */
 void smc_core_exit(void)
 {
+	unregister_reboot_notifier(&smc_reboot_notifier);
 	smc_lgrs_shutdown();
 }