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From: Caleb Sander Mateos <csander@purestorage.com>
To: Ming Lei <ming.lei@redhat.com>, Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
	Caleb Sander Mateos <csander@purestorage.com>
Subject: [PATCH 2/5] ublk: skip 1 NULL check in ublk_cmd_list_tw_cb() loop
Date: Fri, 28 Mar 2025 12:04:08 -0600	[thread overview]
Message-ID: <20250328180411.2696494-3-csander@purestorage.com> (raw)
In-Reply-To: <20250328180411.2696494-1-csander@purestorage.com>

ublk_cmd_list_tw_cb() is always performed on a non-empty request list.
So don't check whether rq is NULL on the first iteration of the loop,
just on subsequent iterations.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
 drivers/block/ublk_drv.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 39efe443e235..8b9780c0feab 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -1288,16 +1288,16 @@ static void ublk_cmd_list_tw_cb(struct io_uring_cmd *cmd,
 	struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(cmd);
 	struct request *rq = pdu->req_list;
 	struct ublk_queue *ubq = rq->mq_hctx->driver_data;
 	struct request *next;
 
-	while (rq) {
+	do {
 		next = rq->rq_next;
 		rq->rq_next = NULL;
 		ublk_dispatch_req(ubq, rq, issue_flags);
 		rq = next;
-	}
+	} while (rq);
 }
 
 static void ublk_queue_cmd_list(struct ublk_queue *ubq, struct rq_list *l)
 {
 	struct request *rq = rq_list_peek(l);
-- 
2.45.2


  parent reply	other threads:[~2025-03-28 18:04 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-03-28 18:04 [PATCH 0/5] Minor ublk optimizations Caleb Sander Mateos
2025-03-28 18:04 ` [PATCH 1/5] ublk: remove unused cmd argument to ublk_dispatch_req() Caleb Sander Mateos
2025-03-28 18:04 ` Caleb Sander Mateos [this message]
2025-03-28 18:04 ` [PATCH 3/5] ublk: get ubq from pdu in ublk_cmd_list_tw_cb() Caleb Sander Mateos
2025-03-28 18:04 ` [PATCH 4/5] ublk: avoid redundant io->cmd in ublk_queue_cmd_list() Caleb Sander Mateos
2025-03-28 18:04 ` [PATCH 5/5] ublk: store req in ublk_uring_cmd_pdu for ublk_cmd_tw_cb() Caleb Sander Mateos
2025-03-28 19:20 ` [PATCH 0/5] Minor ublk optimizations Jens Axboe
2025-03-29  0:23 ` Ming Lei
2025-03-29 11:57 ` Jens Axboe

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