Re: [PATCH 3/3] nvme: use helper nvme_ctrl_state in nvme_keep_alive_end_io function

[Keith Busch <kbusch@kernel.org>]

On Sun, Oct 27, 2024 at 10:32:06PM +0530, Nilay Shroff wrote:
> We no more need acquiring ctrl->lock before accessing the
> NVMe controller state and instead we can now use the helper
> nvme_ctrl_state. So replace the use of ctrl->lock from
> nvme_keep_alive_end_io function with nvme_ctrl_state call.
> 
> Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
> ---
>  drivers/nvme/host/core.c | 11 +++--------
>  1 file changed, 3 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 865c00ea19e3..6e814daf1002 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -1296,10 +1296,9 @@ static enum rq_end_io_ret nvme_keep_alive_end_io(struct request *rq,
>  						 blk_status_t status)
>  {
>  	struct nvme_ctrl *ctrl = rq->end_io_data;
> -	unsigned long flags;
> -	bool startka = false;
>  	unsigned long rtt = jiffies - (rq->deadline - rq->timeout);
>  	unsigned long delay = nvme_keep_alive_work_period(ctrl);
> +	enum nvme_ctrl_state state = nvme_ctrl_state(ctrl->state);
>  
>  	/*
>  	 * Subtract off the keepalive RTT so nvme_keep_alive_work runs
> @@ -1324,13 +1323,9 @@ static enum rq_end_io_ret nvme_keep_alive_end_io(struct request *rq,
>  
>  	ctrl->ka_last_check_time = jiffies;
>  	ctrl->comp_seen = false;
> -	spin_lock_irqsave(&ctrl->lock, flags);
> -	if (ctrl->state == NVME_CTRL_LIVE ||
> -	    ctrl->state == NVME_CTRL_CONNECTING)
> -		startka = true;
> -	spin_unlock_irqrestore(&ctrl->lock, flags);
> -	if (startka)
> +	if (state == NVME_CTRL_LIVE || state == NVME_CTRL_CONNECTING)
>  		queue_delayed_work(nvme_wq, &ctrl->ka_work, delay);
> +
>  	return RQ_END_IO_NONE;
>  }

This restores what you had in the reverted patch, which was a
significant portion of the diff stat. If we're keeping this chunk, maybe
a full revert isn't necessary, and we can squash the series to just one
fixing commit.