Re: [PATCH v3 06/16] block/mq-deadline: Add two lockdep_assert_held() statements

[Adam Manzanares <a.manzanares@samsung.com>]

On Thu, Jun 17, 2021 at 05:44:46PM -0700, Bart Van Assche wrote:
> Document the locking strategy by adding two lockdep_assert_held()
> statements.
> 
> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
> Reviewed-by: Hannes Reinecke <hare@suse.de>
> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
> Cc: Damien Le Moal <damien.lemoal@wdc.com>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Ming Lei <ming.lei@redhat.com>
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> ---
>  block/mq-deadline.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/block/mq-deadline.c b/block/mq-deadline.c
> index 31418e9ce9e2..191ff5ce629c 100644
> --- a/block/mq-deadline.c
> +++ b/block/mq-deadline.c
> @@ -279,6 +279,8 @@ static struct request *__dd_dispatch_request(struct deadline_data *dd)
>  	bool reads, writes;
>  	int data_dir;
>  
> +	lockdep_assert_held(&dd->lock);
> +
>  	if (!list_empty(&dd->dispatch)) {
>  		rq = list_first_entry(&dd->dispatch, struct request, queuelist);
>  		list_del_init(&rq->queuelist);
> @@ -501,6 +503,8 @@ static void dd_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
>  	struct deadline_data *dd = q->elevator->elevator_data;
>  	const int data_dir = rq_data_dir(rq);
>  
> +	lockdep_assert_held(&dd->lock);
> +
>  	/*
>  	 * This may be a requeue of a write request that has locked its
>  	 * target zone. If it is the case, this releases the zone lock.

Looks good.

Reviewed by: Adam Manzanares <a.manzanares@samsung.com>