linux-kernel - [PATCH 10/17] ublk: pass q_id and tag to __ublk_check_and_get

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Message-ID: <20250918014953.297897-11-csander@purestorage.com>
Date: Wed, 17 Sep 2025 19:49:46 -0600
From: Caleb Sander Mateos <csander@...estorage.com>
To: Ming Lei <ming.lei@...hat.com>,
	Jens Axboe <axboe@...nel.dk>
Cc: linux-block@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Caleb Sander Mateos <csander@...estorage.com>
Subject: [PATCH 10/17] ublk: pass q_id and tag to __ublk_check_and_get_req()

__ublk_check_and_get_req() only uses its ublk_queue argument to get the
q_id and tag. Pass those arguments explicitly to save an access to the
ublk_queue.

Signed-off-by: Caleb Sander Mateos <csander@...estorage.com>
---
 drivers/block/ublk_drv.c | 24 +++++++++++-------------
 1 file changed, 11 insertions(+), 13 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 266b46d40886..cb61f6213962 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -248,12 +248,11 @@ struct ublk_params_header {
 
 static void ublk_io_release(void *priv);
 static void ublk_stop_dev_unlocked(struct ublk_device *ub);
 static void ublk_abort_queue(struct ublk_device *ub, struct ublk_queue *ubq);
 static inline struct request *__ublk_check_and_get_req(struct ublk_device *ub,
-		const struct ublk_queue *ubq, struct ublk_io *io,
-		size_t offset);
+		u16 q_id, u16 tag, struct ublk_io *io, size_t offset);
 static inline unsigned int ublk_req_build_flags(struct request *req);
 
 static inline struct ublksrv_io_desc *
 ublk_get_iod(const struct ublk_queue *ubq, unsigned tag)
 {
@@ -2124,21 +2123,21 @@ static void ublk_io_release(void *priv)
 		ublk_put_req_ref(io, rq);
 }
 
 static int ublk_register_io_buf(struct io_uring_cmd *cmd,
 				struct ublk_device *ub,
-				const struct ublk_queue *ubq,
+				u16 q_id, u16 tag,
 				struct ublk_io *io,
 				unsigned int index, unsigned int issue_flags)
 {
 	struct request *req;
 	int ret;
 
 	if (!ublk_dev_support_zero_copy(ub))
 		return -EINVAL;
 
-	req = __ublk_check_and_get_req(ub, ubq, io, 0);
+	req = __ublk_check_and_get_req(ub, q_id, tag, io, 0);
 	if (!req)
 		return -EINVAL;
 
 	ret = io_buffer_register_bvec(cmd, req, ublk_io_release, index,
 				      issue_flags);
@@ -2151,11 +2150,11 @@ static int ublk_register_io_buf(struct io_uring_cmd *cmd,
 }
 
 static int
 ublk_daemon_register_io_buf(struct io_uring_cmd *cmd,
 			    struct ublk_device *ub,
-			    const struct ublk_queue *ubq, struct ublk_io *io,
+			    u16 q_id, u16 tag, struct ublk_io *io,
 			    unsigned index, unsigned issue_flags)
 {
 	unsigned new_registered_buffers;
 	struct request *req = io->req;
 	int ret;
@@ -2164,11 +2163,11 @@ ublk_daemon_register_io_buf(struct io_uring_cmd *cmd,
 	 * Ensure there are still references for ublk_sub_req_ref() to release.
 	 * If not, fall back on the thread-safe buffer registration.
 	 */
 	new_registered_buffers = io->task_registered_buffers + 1;
 	if (unlikely(new_registered_buffers >= UBLK_REFCOUNT_INIT))
-		return ublk_register_io_buf(cmd, ub, ubq, io, index,
+		return ublk_register_io_buf(cmd, ub, q_id, tag, io, index,
 					    issue_flags);
 
 	if (!ublk_dev_support_zero_copy(ub) || !ublk_rq_has_data(req))
 		return -EINVAL;
 
@@ -2356,12 +2355,12 @@ static int ublk_ch_uring_cmd_local(struct io_uring_cmd *cmd,
 		/*
 		 * ublk_register_io_buf() accesses only the io's refcount,
 		 * so can be handled on any task
 		 */
 		if (_IOC_NR(cmd_op) == UBLK_IO_REGISTER_IO_BUF)
-			return ublk_register_io_buf(cmd, ub, ubq, io, addr,
-						    issue_flags);
+			return ublk_register_io_buf(cmd, ub, q_id, tag, io,
+						    addr, issue_flags);
 
 		goto out;
 	}
 
 	/* there is pending io cmd, something must be wrong */
@@ -2378,11 +2377,11 @@ static int ublk_ch_uring_cmd_local(struct io_uring_cmd *cmd,
 			^ (_IOC_NR(cmd_op) == UBLK_IO_NEED_GET_DATA))
 		goto out;
 
 	switch (_IOC_NR(cmd_op)) {
 	case UBLK_IO_REGISTER_IO_BUF:
-		return ublk_daemon_register_io_buf(cmd, ub, ubq, io, addr,
+		return ublk_daemon_register_io_buf(cmd, ub, q_id, tag, io, addr,
 						   issue_flags);
 	case UBLK_IO_COMMIT_AND_FETCH_REQ:
 		ret = ublk_check_commit_and_fetch(ubq, io, addr);
 		if (ret)
 			goto out;
@@ -2427,20 +2426,19 @@ static int ublk_ch_uring_cmd_local(struct io_uring_cmd *cmd,
 			__func__, cmd_op, tag, ret, io->flags);
 	return ret;
 }
 
 static inline struct request *__ublk_check_and_get_req(struct ublk_device *ub,
-		const struct ublk_queue *ubq, struct ublk_io *io, size_t offset)
+		u16 q_id, u16 tag, struct ublk_io *io, size_t offset)
 {
-	unsigned tag = io - ubq->ios;
 	struct request *req;
 
 	/*
 	 * can't use io->req in case of concurrent UBLK_IO_COMMIT_AND_FETCH_REQ,
 	 * which would overwrite it with io->cmd
 	 */
-	req = blk_mq_tag_to_rq(ub->tag_set.tags[ubq->q_id], tag);
+	req = blk_mq_tag_to_rq(ub->tag_set.tags[q_id], tag);
 	if (!req)
 		return NULL;
 
 	if (!ublk_get_req_ref(io))
 		return NULL;
@@ -2534,11 +2532,11 @@ static struct request *ublk_check_and_get_req(struct kiocb *iocb,
 
 	if (tag >= ub->dev_info.queue_depth)
 		return ERR_PTR(-EINVAL);
 
 	*io = &ubq->ios[tag];
-	req = __ublk_check_and_get_req(ub, ubq, *io, buf_off);
+	req = __ublk_check_and_get_req(ub, q_id, tag, *io, buf_off);
 	if (!req)
 		return ERR_PTR(-EINVAL);
 
 	if (!req->mq_hctx || !req->mq_hctx->driver_data)
 		goto fail;
-- 
2.45.2