From: Lai Jiangshan <jiangshan.ljs@antgroup.com>
kthread_flush_worker() can't be called with wq_pool_mutex held.
Prepare for moving wq_pool_mutex and cpu hotplug lock out of
alloc_and_link_pwqs().
Cc: Zqiang <qiang.zhang1211@gmail.com>
Link: https://lore.kernel.org/lkml/20230920060704.24981-1-qiang.zhang1211@gmail.com/
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
---
kernel/workqueue.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 810ea55c0ac9..3203c67ec4cb 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -5472,12 +5472,6 @@ static int alloc_and_link_pwqs(struct workqueue_struct *wq)
}
cpus_read_unlock();
- /* for unbound pwq, flush the pwq_release_worker ensures that the
- * pwq_release_workfn() completes before calling kfree(wq).
- */
- if (ret)
- kthread_flush_worker(pwq_release_worker);
-
return ret;
enomem:
@@ -5731,6 +5725,14 @@ struct workqueue_struct *alloc_workqueue(const char *fmt,
return wq;
err_free_rescuer:
+ /*
+ * Failed alloc_and_link_pwqs() may leave pending pwq->release_work,
+ * flushing the pwq_release_worker ensures that the pwq_release_workfn()
+ * completes before calling kfree(wq).
+ */
+ if (wq->flags & WQ_UNBOUND)
+ kthread_flush_worker(pwq_release_worker);
+
destroy_rescuer(wq);
err_free_node_nr_active:
if (wq->flags & WQ_UNBOUND)
--
2.19.1.6.gb485710b