Re: [PATCH 2/2] bdi: Avoid oops on device removal

From: Tejun Heo
Date: Thu Feb 27 2014 - 15:08:04 EST


Hello,

On Tue, Feb 25, 2014 at 11:29:14PM +0100, Jan Kara wrote:
> +static void bdi_wakeup_thread(struct backing_dev_info *bdi)
> +{
> + spin_lock_bh(&bdi->wb_lock);
> + if (test_bit(BDI_registered, &bdi->state))
> + mod_delayed_work(bdi_wq, &bdi->wb.dwork, 0);
> + spin_unlock_bh(&bdi->wb_lock);
> +}

I wonder whether this can be smarter without requiring wb_lock each
timer but this probably is the simplest for -stable backports.

> static void bdi_queue_work(struct backing_dev_info *bdi,
> struct wb_writeback_work *work)
> {
> trace_writeback_queue(bdi, work);
>
> spin_lock_bh(&bdi->wb_lock);
> + if (!test_bit(BDI_registered, &bdi->state)) {
> + if (work->done)
> + complete(work->done);
> + goto out_unlock;
> + }
> list_add_tail(&work->list, &bdi->work_list);
> - spin_unlock_bh(&bdi->wb_lock);
> -
> mod_delayed_work(bdi_wq, &bdi->wb.dwork, 0);
> +out_unlock:
> + spin_unlock_bh(&bdi->wb_lock);
> }
>
> +
> +

Why three blank lines?

Other than that,

Reviewed-by: Tejun Heo <tj@xxxxxxxxxx>

Thanks.

--
tejun
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/