[PATCH 3.14 153/228] workqueue: fix bugs in wq_update_unbound_numa() failure path

Greg Kroah-Hartman
2014-06-04T23:22:47Z

From: Daeseok Youn <daeseok.youn@gmail.com>

commit 77f300b198f93328c26191b52655ce1b62e202cf upstream.

wq_update_unbound_numa() failure path has the following two bugs.

- alloc_unbound_pwq() is called without holding wq->mutex; however, if
the allocation fails, it jumps to out_unlock which tries to unlock
wq->mutex.

- The function should switch to dfl_pwq on failure but didn't do so
after alloc_unbound_pwq() failure.

Fix it by regrabbing wq->mutex and jumping to use_dfl_pwq on
alloc_unbound_pwq() failure.

Signed-off-by: Daeseok Youn <daeseok.youn@gmail.com>
Acked-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 4c16bd327c74 ("workqueue: implement NUMA affinity for unbound workqueues")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
kernel/workqueue.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -4093,7 +4093,8 @@ static void wq_update_unbound_numa(struc
if (!pwq) {
pr_warning("workqueue: allocation failed while updating NUMA affinity of \"%s\"\n",
wq->name);
- goto out_unlock;
+ mutex_lock(&wq->mutex);
+ goto use_dfl_pwq;
}

/*