From e412f9201de255a503ae3d67f46aae580c79006c Mon Sep 17 00:00:00 2001
From: "tsutomu.owa@toshiba.co.jp" <tsutomu.owa@toshiba.co.jp>
Date: Tue, 12 Sep 2017 08:56:30 +0000
Subject: [PATCH 10/19] DLM: fix race condition between dlm_recoverd_stop and
 dlm_recoverd
Git-commit: e412f9201de255a503ae3d67f46aae580c79006c
Patch-mainline: v4.15-rc1
References: bsc#1074590

When dlm_recoverd_stop() is called between kthread_should_stop() and
set_task_state(TASK_INTERRUPTIBLE), dlm_recoverd will not wake up.

Signed-off-by: Tadashi Miyauchi <miyauchi@toshiba-tops.co.jp>
Signed-off-by: Tsutomu Owa <tsutomu.owa@toshiba.co.jp>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Gang He <ghe@suse.com>
---
 fs/dlm/recoverd.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/fs/dlm/recoverd.c b/fs/dlm/recoverd.c
index 6859b4b..d2ad1ca 100644
--- a/fs/dlm/recoverd.c
+++ b/fs/dlm/recoverd.c
@@ -287,8 +287,17 @@ static int dlm_recoverd(void *arg)
 	set_bit(LSFL_RECOVER_LOCK, &ls->ls_flags);
 	wake_up(&ls->ls_recover_lock_wait);
 
-	while (!kthread_should_stop()) {
+	while (1) {
+		/*
+		 * We call kthread_should_stop() after set_current_state().
+		 * This is because it works correctly if kthread_stop() is
+		 * called just before set_current_state().
+		 */
 		set_current_state(TASK_INTERRUPTIBLE);
+		if (kthread_should_stop()) {
+			set_current_state(TASK_RUNNING);
+			break;
+		}
 		if (!test_bit(LSFL_RECOVER_WORK, &ls->ls_flags) &&
 		    !test_bit(LSFL_RECOVER_DOWN, &ls->ls_flags))
 			schedule();
-- 
1.8.5.6