From: Joonsoo Kim <js1304@gmail.com>
Date: Tue, 30 Apr 2013 15:07:00 +0000 (+0900)
Subject: workqueue: correct handling of the pool spin_lock
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=8f174b1175a10903ade40f36eb6c896412877ca0;p=openwrt%2Fstaging%2Fblogic.git

workqueue: correct handling of the pool spin_lock

When we fail to mutex_trylock(), we release the pool spin_lock and do
mutex_lock(). After that, we should regrab the pool spin_lock, but,
regrabbing is missed in current code. So correct it.

Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 1ae602809efb..286847b90225 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -2059,6 +2059,7 @@ static bool manage_workers(struct worker *worker)
 	if (unlikely(!mutex_trylock(&pool->manager_mutex))) {
 		spin_unlock_irq(&pool->lock);
 		mutex_lock(&pool->manager_mutex);
+		spin_lock_irq(&pool->lock);
 		ret = true;
 	}