cpuset: Fix the bug that subpart_cpus updated wrongly in update_cpumask()

commit c80d401c52a2d1baf2a5afeb06f0ffe678e56d23 upstream.

subparts_cpus should be limited as a subset of cpus_allowed, but it is
updated wrongly by using cpumask_andnot(). Use cpumask_and() instead to
fix it.

Fixes: ee8dde0cd2ce ("cpuset: Add new v2 cpuset.sched.partition flag")
Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 2a9695c..1d9d3e4 100644 (file)
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -1597,8 +1597,7 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
         * Make sure that subparts_cpus is a subset of cpus_allowed.
         */
        if (cs->nr_subparts_cpus) {
-               cpumask_andnot(cs->subparts_cpus, cs->subparts_cpus,
-                              cs->cpus_allowed);
+               cpumask_and(cs->subparts_cpus, cs->subparts_cpus, cs->cpus_allowed);
                cs->nr_subparts_cpus = cpumask_weight(cs->subparts_cpus);
        }
        spin_unlock_irq(&callback_lock);