On Mon, Mar 23, 2020 at 09:22:54PM +0800, Yufen Yu wrote:
> diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
> index 82d2401fec37..1c0e2d0d6236 100644
> --- a/include/linux/backing-dev.h
> +++ b/include/linux/backing-dev.h
> @@ -525,12 +525,16 @@ static inline const char *bdi_dev_name(struct backing_dev_info *bdi)
> static inline char *bdi_get_dev_name(struct backing_dev_info *bdi,
> char *dname, int len)
> {
> + spin_lock_irq(&bdi->lock);
> if (!bdi || !bdi->dev) {
> + spin_unlock_irq(&bdi->lock);
You can't test for (!bdi) right after you accessed bdi->lock :(
