[PATCHv2 3/3] nvme: use helper nvme_ctrl_state in nvme_keep_alive_end_io function

[Nilay Shroff <nilay@linux.ibm.com>]

We use WRITE_ONCE() for updating the ctrl->state value. So it makes
sense to pair the read of ctrl->state using READ_ONCE(). The helper
nvme_ctrl_state(), helps reads the ctrl->state using READ_ONCE().

In nvme_keep_alive_end_io function, we first acquire ctrl->lock before
reading ctrl->state. However, with use of helper nvme_ctrl_state()
we can avoid ctrl->lock. So this commit removes the ctrl->lock and
replaces it 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..802634022bfa 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);
 
 	/*
 	 * 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;
 }
 
-- 
2.45.2