[PATCH 4/5] ublk: avoid redundant io->cmd in ublk_queue_cmd_list()

[Caleb Sander Mateos <csander@purestorage.com>]

ublk_queue_cmd_list() loads io->cmd twice. The intervening stores
prevent the compiler from combining the loads. Since struct ublk_io *io
is only used to compute io->cmd, replace the variable with io->cmd.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
 drivers/block/ublk_drv.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 9276d1fcc100..23250471562a 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -1299,16 +1299,16 @@ static void ublk_cmd_list_tw_cb(struct io_uring_cmd *cmd,
 }
 
 static void ublk_queue_cmd_list(struct ublk_queue *ubq, struct rq_list *l)
 {
 	struct request *rq = rq_list_peek(l);
-	struct ublk_io *io = &ubq->ios[rq->tag];
-	struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(io->cmd);
+	struct io_uring_cmd *cmd = ubq->ios[rq->tag].cmd;
+	struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(cmd);
 
 	pdu->req_list = rq;
 	rq_list_init(l);
-	io_uring_cmd_complete_in_task(io->cmd, ublk_cmd_list_tw_cb);
+	io_uring_cmd_complete_in_task(cmd, ublk_cmd_list_tw_cb);
 }
 
 static enum blk_eh_timer_return ublk_timeout(struct request *rq)
 {
 	struct ublk_queue *ubq = rq->mq_hctx->driver_data;
-- 
2.45.2