On 2018/04/23 19:09, Tetsuo Handa wrote:
> By the way, I got a newbie question regarding commit 5318ce7d46866e1d ("bdi:
> Shutdown writeback on all cgwbs in cgwb_bdi_destroy()"). It uses clear_bit()
> to clear WB_shutting_down bit so that threads waiting at wait_on_bit() will
> wake up. But clear_bit() itself does not wake up threads, does it? Who wakes
> them up (e.g. by calling wake_up_bit()) after clear_bit() was called?
>
Below report might be waiting for wake_up_bit() ?
INFO: task hung in wb_shutdown (2)
https://syzkaller.appspot.com/bug?id=b297474817af98d5796bc544e1bb806fc3da0e5e
