[PATCH 5/5] ublk: store req in ublk_uring_cmd_pdu for ublk_cmd_tw_cb()
From: Caleb Sander Mateos
Date: Fri Mar 28 2025 - 14:05:24 EST
Pass struct request *rq to ublk_cmd_tw_cb() through ublk_uring_cmd_pdu,
mirroring how it works for ublk_cmd_list_tw_cb(). This saves some
pointer dereferences, as well as the bounds check in blk_mq_tag_to_rq().
Signed-off-by: Caleb Sander Mateos <csander@xxxxxxxxxxxxxxx>
---
drivers/block/ublk_drv.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 23250471562a..466a23b89379 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -87,11 +87,14 @@ struct ublk_uring_cmd_pdu {
*
* It should have been stored to request payload, but we do want
* to avoid extra pre-allocation, and uring_cmd payload is always
* free for us
*/
- struct request *req_list;
+ union {
+ struct request *req;
+ struct request *req_list;
+ };
/*
* The following two are valid in this cmd whole lifetime, and
* setup in ublk uring_cmd handler
*/
@@ -1266,22 +1269,21 @@ static void ublk_dispatch_req(struct ublk_queue *ubq,
static void ublk_cmd_tw_cb(struct io_uring_cmd *cmd,
unsigned int issue_flags)
{
struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(cmd);
struct ublk_queue *ubq = pdu->ubq;
- int tag = pdu->tag;
- struct request *req = blk_mq_tag_to_rq(
- ubq->dev->tag_set.tags[ubq->q_id], tag);
- ublk_dispatch_req(ubq, req, issue_flags);
+ ublk_dispatch_req(ubq, pdu->req, issue_flags);
}
static void ublk_queue_cmd(struct ublk_queue *ubq, struct request *rq)
{
- struct ublk_io *io = &ubq->ios[rq->tag];
+ struct io_uring_cmd *cmd = ubq->ios[rq->tag].cmd;
+ struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(cmd);
- io_uring_cmd_complete_in_task(io->cmd, ublk_cmd_tw_cb);
+ pdu->req = rq;
+ io_uring_cmd_complete_in_task(cmd, ublk_cmd_tw_cb);
}
static void ublk_cmd_list_tw_cb(struct io_uring_cmd *cmd,
unsigned int issue_flags)
{
--
2.45.2