workqueue: fix GCWQ_DISASSOCIATED initialization

init_workqueues() incorrectly marks workqueues for all possible CPUs
associated.  Combined with mayday_mask initialization bug, this can
make rescuers keep trying to bind to an offline gcwq indefinitely.
Fix init_workqueues() such that only online CPUs have their gcwqs have
GCWQ_DISASSOCIATED cleared.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: CAI Qian <caiqian@redhat.com>

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index a2dccfca03ba7f122532f28519e134a4c63a92e5..c8183b235d16078f713da799a1430a92c300d025 100644 (file)
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -3558,8 +3558,7 @@ static int __init init_workqueues(void)
                spin_lock_init(&gcwq->lock);
                INIT_LIST_HEAD(&gcwq->worklist);
                gcwq->cpu = cpu;
-               if (cpu == WORK_CPU_UNBOUND)
-                       gcwq->flags |= GCWQ_DISASSOCIATED;
+               gcwq->flags |= GCWQ_DISASSOCIATED;
 
                INIT_LIST_HEAD(&gcwq->idle_list);
                for (i = 0; i < BUSY_WORKER_HASH_SIZE; i++)
@@ -3583,6 +3582,8 @@ static int __init init_workqueues(void)
                struct global_cwq *gcwq = get_gcwq(cpu);
                struct worker *worker;
 
+               if (cpu != WORK_CPU_UNBOUND)
+                       gcwq->flags &= ~GCWQ_DISASSOCIATED;
                worker = create_worker(gcwq, true);
                BUG_ON(!worker);
                spin_lock_irq(&gcwq->lock);