From: Oleg Nesterov work->func() may sleep, it's a bug to call run_workqueue() with irqs disabled. Signed-off-by: Oleg Nesterov Cc: Ingo Molnar Signed-off-by: Andrew Morton --- kernel/workqueue.c | 18 ++++++++---------- 1 files changed, 8 insertions(+), 10 deletions(-) diff -puN kernel/workqueue.c~workqueue-dont-save-interrupts-in-run_workqueue kernel/workqueue.c --- a/kernel/workqueue.c~workqueue-dont-save-interrupts-in-run_workqueue +++ a/kernel/workqueue.c @@ -227,13 +227,7 @@ EXPORT_SYMBOL_GPL(queue_delayed_work_on) static void run_workqueue(struct cpu_workqueue_struct *cwq) { - unsigned long flags; - - /* - * Keep taking off work from the queue until - * done. - */ - spin_lock_irqsave(&cwq->lock, flags); + spin_lock_irq(&cwq->lock); cwq->run_depth++; if (cwq->run_depth > 3) { /* morton gets to eat his hat */ @@ -248,7 +242,7 @@ static void run_workqueue(struct cpu_wor cwq->current_work = work; list_del_init(cwq->worklist.next); - spin_unlock_irqrestore(&cwq->lock, flags); + spin_unlock_irq(&cwq->lock); BUG_ON(get_wq_data(work) != cwq); if (!test_bit(WORK_STRUCT_NOAUTOREL, work_data_bits(work))) @@ -266,11 +260,11 @@ static void run_workqueue(struct cpu_wor dump_stack(); } - spin_lock_irqsave(&cwq->lock, flags); + spin_lock_irq(&cwq->lock); cwq->current_work = NULL; } cwq->run_depth--; - spin_unlock_irqrestore(&cwq->lock, flags); + spin_unlock_irq(&cwq->lock); } /* @@ -399,6 +393,8 @@ static void flush_cpu_workqueue(struct c */ void fastcall flush_workqueue(struct workqueue_struct *wq) { + might_sleep(); + if (is_single_threaded(wq)) flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, singlethread_cpu)); else { @@ -445,6 +441,8 @@ void flush_work(struct workqueue_struct { struct cpu_workqueue_struct *cwq; + might_sleep(); + cwq = get_wq_data(work); /* Was it ever queued ? */ if (!cwq) _