[2/2] block: null_blk: cleanup null_queue_rq()

Commit Message

Damien Le Moal March 14, 2023, 4:11 a.m. UTC

Use a local struct request pointer variable to avoid having to
dereference struct blk_mq_queue_data multiple times. While at it, also
fix the function argument indentation and remove a useless "else" after
a return.

Signed-off-by: Damien Le Moal <[e-mail]>
---
 drivers/block/null_blk/main.c | 29 ++++++++++++++---------------
 1 file changed, 14 insertions(+), 15 deletions(-)

Comments

Pankaj Raghav March 14, 2023, 9:51 a.m. UTC | #1

On Tue, Mar 14, 2023 at 01:11:06PM +0900, Damien Le Moal wrote:
> Use a local struct request pointer variable to avoid having to
> dereference struct blk_mq_queue_data multiple times. While at it, also
> fix the function argument indentation and remove a useless "else" after
> a return.
> 
> Signed-off-by: Damien Le Moal <[e-mail]>
> ---
>  drivers/block/null_blk/main.c | 29 ++++++++++++++---------------
>  1 file changed, 14 insertions(+), 15 deletions(-)

Looks good,
Reviewed-by: Pankaj Raghav <[e-mail]>

Johannes Thumshirn March 15, 2023, 8:53 a.m. UTC | #2

Looks good,
Reviewed-by: Johannes Thumshirn <[e-mail]>

Patch

diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index 7d95ad203c97..9e6b032c8ecc 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -1657,12 +1657,13 @@  static enum blk_eh_timer_return null_timeout_rq(struct request *rq)
 }
 
 static blk_status_t null_queue_rq(struct blk_mq_hw_ctx *hctx,
-			 const struct blk_mq_queue_data *bd)
+				  const struct blk_mq_queue_data *bd)
 {
-	struct nullb_cmd *cmd = blk_mq_rq_to_pdu(bd->rq);
+	struct request *rq = bd->rq;
+	struct nullb_cmd *cmd = blk_mq_rq_to_pdu(rq);
 	struct nullb_queue *nq = hctx->driver_data;
-	sector_t nr_sectors = blk_rq_sectors(bd->rq);
-	sector_t sector = blk_rq_pos(bd->rq);
+	sector_t nr_sectors = blk_rq_sectors(rq);
+	sector_t sector = blk_rq_pos(rq);
 	const bool is_poll = hctx->type == HCTX_TYPE_POLL;
 
 	might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING);
@@ -1671,15 +1672,15 @@  static blk_status_t null_queue_rq(struct blk_mq_hw_ctx *hctx,
 		hrtimer_init(&cmd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
 		cmd->timer.function = null_cmd_timer_expired;
 	}
-	cmd->rq = bd->rq;
+	cmd->rq = rq;
 	cmd->error = BLK_STS_OK;
 	cmd->nq = nq;
-	cmd->fake_timeout = should_timeout_request(bd->rq) ||
-		blk_should_fake_timeout(bd->rq->q);
+	cmd->fake_timeout = should_timeout_request(rq) ||
+		blk_should_fake_timeout(rq->q);
 
-	blk_mq_start_request(bd->rq);
+	blk_mq_start_request(rq);
 
-	if (should_requeue_request(bd->rq)) {
+	if (should_requeue_request(rq)) {
 		/*
 		 * Alternate between hitting the core BUSY path, and the
 		 * driver driven requeue path
@@ -1687,22 +1688,20 @@  static blk_status_t null_queue_rq(struct blk_mq_hw_ctx *hctx,
 		nq->requeue_selection++;
 		if (nq->requeue_selection & 1)
 			return BLK_STS_RESOURCE;
-		else {
-			blk_mq_requeue_request(bd->rq, true);
-			return BLK_STS_OK;
-		}
+		blk_mq_requeue_request(rq, true);
+		return BLK_STS_OK;
 	}
 
 	if (is_poll) {
 		spin_lock(&nq->poll_lock);
-		list_add_tail(&bd->rq->queuelist, &nq->poll_list);
+		list_add_tail(&rq->queuelist, &nq->poll_list);
 		spin_unlock(&nq->poll_lock);
 		return BLK_STS_OK;
 	}
 	if (cmd->fake_timeout)
 		return BLK_STS_OK;
 
-	return null_handle_cmd(cmd, sector, nr_sectors, req_op(bd->rq));
+	return null_handle_cmd(cmd, sector, nr_sectors, req_op(rq));
 }
 
 static void cleanup_queue(struct nullb_queue *nq)