[PATCH 1/2] workqueue: Update cpumasks after only applying it successfully

[Lai Jiangshan <jiangshanlai@gmail.com>]

From: Lai Jiangshan <jiangshan.ljs@antgroup.com>

Make workqueue_unbound_exclude_cpumask() and workqueue_set_unbound_cpumask()
only update wq_isolated_cpumask and wq_requested_unbound_cpumask when
workqueue_apply_unbound_cpumask() returns successfully.

Fixes: fe28f631fa94("workqueue: Add workqueue_unbound_exclude_cpumask() to exclude CPUs from wq_unbound_cpumask")
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
---
 kernel/workqueue.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index dc9acf8ecd0c..a3f9ff4fe657 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -6853,9 +6853,6 @@ int workqueue_unbound_exclude_cpumask(cpumask_var_t exclude_cpumask)
 	lockdep_assert_cpus_held();
 	mutex_lock(&wq_pool_mutex);
 
-	/* Save the current isolated cpumask & export it via sysfs */
-	cpumask_copy(wq_isolated_cpumask, exclude_cpumask);
-
 	/*
 	 * If the operation fails, it will fall back to
 	 * wq_requested_unbound_cpumask which is initially set to
@@ -6867,6 +6864,10 @@ int workqueue_unbound_exclude_cpumask(cpumask_var_t exclude_cpumask)
 	if (!cpumask_equal(cpumask, wq_unbound_cpumask))
 		ret = workqueue_apply_unbound_cpumask(cpumask);
 
+	/* Save the current isolated cpumask & export it via sysfs */
+	if (!ret)
+		cpumask_copy(wq_isolated_cpumask, exclude_cpumask);
+
 	mutex_unlock(&wq_pool_mutex);
 	free_cpumask_var(cpumask);
 	return ret;
@@ -7202,7 +7203,6 @@ static int workqueue_set_unbound_cpumask(cpumask_var_t cpumask)
 	cpumask_and(cpumask, cpumask, cpu_possible_mask);
 	if (!cpumask_empty(cpumask)) {
 		apply_wqattrs_lock();
-		cpumask_copy(wq_requested_unbound_cpumask, cpumask);
 		if (cpumask_equal(cpumask, wq_unbound_cpumask)) {
 			ret = 0;
 			goto out_unlock;
@@ -7211,6 +7211,8 @@ static int workqueue_set_unbound_cpumask(cpumask_var_t cpumask)
 		ret = workqueue_apply_unbound_cpumask(cpumask);
 
 out_unlock:
+		if (!ret)
+			cpumask_copy(wq_requested_unbound_cpumask, cpumask);
 		apply_wqattrs_unlock();
 	}
 
-- 
2.19.1.6.gb485710b