[PATCH 3/3] io_uring: get rid of io_preinit_req()

[Jens Axboe <axboe@kernel.dk>]

Just assign where we setup the ring anyway, splitting the init into
two doesn't really buy us anything and it's a bit more fragile. With
this, io_init_req() handles the whole thing while the cacheline is
pulled in anyway.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 io_uring/io_uring.c | 19 ++++---------------
 1 file changed, 4 insertions(+), 15 deletions(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index a0b64831c455..7f5d0b833955 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -1034,19 +1034,6 @@ void io_req_defer_failed(struct io_kiocb *req, s32 res)
 	io_req_complete_defer(req);
 }
 
-/*
- * Don't initialise the fields below on every allocation, but do that in
- * advance and keep them valid across allocations.
- */
-static void io_preinit_req(struct io_kiocb *req, struct io_ring_ctx *ctx)
-{
-	req->ctx = ctx;
-	req->link = NULL;
-	req->async_data = NULL;
-	/* not necessary, but safer to zero */
-	req->cqe.res = 0;
-}
-
 static void io_flush_cached_locked_reqs(struct io_ring_ctx *ctx,
 					struct io_submit_state *state)
 {
@@ -1097,7 +1084,6 @@ __cold bool __io_alloc_req_refill(struct io_ring_ctx *ctx)
 	for (i = 0; i < ret; i++) {
 		struct io_kiocb *req = reqs[i];
 
-		io_preinit_req(req, ctx);
 		io_req_add_to_cache(req, ctx);
 	}
 	return true;
@@ -2172,14 +2158,17 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
 	int personality;
 	u8 opcode;
 
-	/* req is partially pre-initialised, see io_preinit_req() */
 	req->opcode = opcode = READ_ONCE(sqe->opcode);
 	/* same numerical values with corresponding REQ_F_*, safe to copy */
 	req->flags = sqe_flags = READ_ONCE(sqe->flags);
 	req->cqe.user_data = READ_ONCE(sqe->user_data);
+	req->cqe.res = 0;
+	req->ctx = ctx;
 	req->file = NULL;
 	req->rsrc_node = NULL;
 	req->task = current;
+	req->async_data = NULL;
+	req->link = NULL;
 
 	if (unlikely(opcode >= IORING_OP_LAST)) {
 		req->opcode = 0;
-- 
2.39.2