linux-kernel - [PATCH 4/4] io_uring/cmd: remove struct io_uring_cmd

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Message-ID: <20250619192748.3602122-5-csander@purestorage.com>
Date: Thu, 19 Jun 2025 13:27:48 -0600
From: Caleb Sander Mateos <csander@...estorage.com>
To: Chris Mason <clm@...com>,
	Josef Bacik <josef@...icpanda.com>,
	David Sterba <dsterba@...e.com>,
	Jens Axboe <axboe@...nel.dk>
Cc: Mark Harmstone <maharmstone@...com>,
	linux-btrfs@...r.kernel.org,
	io-uring@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Caleb Sander Mateos <csander@...estorage.com>
Subject: [PATCH 4/4] io_uring/cmd: remove struct io_uring_cmd_data

There are no more users of struct io_uring_cmd_data and its op_data
field. Remove it to shave 8 bytes from struct io_async_cmd and eliminate
a store and load for every uring_cmd.

Signed-off-by: Caleb Sander Mateos <csander@...estorage.com>
---
 include/linux/io_uring/cmd.h |  9 ---------
 io_uring/uring_cmd.c         | 12 +-----------
 io_uring/uring_cmd.h         |  1 -
 3 files changed, 1 insertion(+), 21 deletions(-)

diff --git a/include/linux/io_uring/cmd.h b/include/linux/io_uring/cmd.h
index 29892f54e0ac..cfa6d0c0c322 100644
--- a/include/linux/io_uring/cmd.h
+++ b/include/linux/io_uring/cmd.h
@@ -19,14 +19,10 @@ struct io_uring_cmd {
 	u32		cmd_op;
 	u32		flags;
 	u8		pdu[32]; /* available inline for free use */
 };
 
-struct io_uring_cmd_data {
-	void			*op_data;
-};
-
 static inline const void *io_uring_sqe_cmd(const struct io_uring_sqe *sqe)
 {
 	return sqe->cmd;
 }
 
@@ -135,15 +131,10 @@ static inline void io_uring_cmd_complete_in_task(struct io_uring_cmd *ioucmd,
 static inline struct task_struct *io_uring_cmd_get_task(struct io_uring_cmd *cmd)
 {
 	return cmd_to_io_kiocb(cmd)->tctx->task;
 }
 
-static inline struct io_uring_cmd_data *io_uring_cmd_get_async_data(struct io_uring_cmd *cmd)
-{
-	return cmd_to_io_kiocb(cmd)->async_data;
-}
-
 /*
  * Return uring_cmd's context reference as its context handle for driver to
  * track per-context resource, such as registered kernel IO buffer
  */
 static inline void *io_uring_cmd_ctx_handle(struct io_uring_cmd *cmd)
diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
index 7cddc4c1c554..376404ffb3f9 100644
--- a/io_uring/uring_cmd.c
+++ b/io_uring/uring_cmd.c
@@ -23,25 +23,19 @@ void io_cmd_cache_free(const void *entry)
 
 static void io_req_uring_cleanup(struct io_kiocb *req, unsigned int issue_flags)
 {
 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
 	struct io_async_cmd *ac = req->async_data;
-	struct io_uring_cmd_data *cache = &ac->data;
-
-	if (cache->op_data) {
-		kfree(cache->op_data);
-		cache->op_data = NULL;
-	}
 
 	if (issue_flags & IO_URING_F_UNLOCKED)
 		return;
 
 	io_alloc_cache_vec_kasan(&ac->vec);
 	if (ac->vec.nr > IO_VEC_CACHE_SOFT_CAP)
 		io_vec_free(&ac->vec);
 
-	if (io_alloc_cache_put(&req->ctx->cmd_cache, cache)) {
+	if (io_alloc_cache_put(&req->ctx->cmd_cache, ac)) {
 		ioucmd->sqe = NULL;
 		req->async_data = NULL;
 		req->flags &= ~(REQ_F_ASYNC_DATA|REQ_F_NEED_CLEANUP);
 	}
 }
@@ -185,17 +179,13 @@ static int io_uring_cmd_prep_setup(struct io_kiocb *req,
 				   const struct io_uring_sqe *sqe)
 {
 	struct io_uring_cmd *ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
 	struct io_async_cmd *ac;
 
-	/* see io_uring_cmd_get_async_data() */
-	BUILD_BUG_ON(offsetof(struct io_async_cmd, data) != 0);
-
 	ac = io_uring_alloc_async_data(&req->ctx->cmd_cache, req);
 	if (!ac)
 		return -ENOMEM;
-	ac->data.op_data = NULL;
 
 	/*
 	 * Unconditionally cache the SQE for now - this is only needed for
 	 * requests that go async, but prep handlers must ensure that any
 	 * sqe data is stable beyond prep. Since uring_cmd is special in
diff --git a/io_uring/uring_cmd.h b/io_uring/uring_cmd.h
index e6a5142c890e..351c58c26679 100644
--- a/io_uring/uring_cmd.h
+++ b/io_uring/uring_cmd.h
@@ -2,11 +2,10 @@
 
 #include <linux/io_uring/cmd.h>
 #include <linux/io_uring_types.h>
 
 struct io_async_cmd {
-	struct io_uring_cmd_data	data;
 	struct iou_vec			vec;
 	struct io_uring_sqe		sqes[2];
 };
 
 int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags);
-- 
2.45.2