[PATCH v2 07/14] io_uring/rw: avoid punting to io-wq directly

[Pavel Begunkov <asml.silence@gmail.com>]

kiocb_done() should care to specifically redirecting requests to io-wq.
Remove the hopping to tw to then queue an io-wq, return -EAGAIN and let
the core code io_uring handle offloading.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/595021a813bebf0256e80b95bcc594377096e08b.1710514702.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 io_uring/io_uring.c | 8 ++++----
 io_uring/io_uring.h | 1 -
 io_uring/rw.c       | 8 +-------
 3 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 5d4b448fdc50..9d7bbdea6db5 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -498,7 +498,7 @@ static void io_prep_async_link(struct io_kiocb *req)
 	}
 }
 
-void io_queue_iowq(struct io_kiocb *req, struct io_tw_state *ts_dont_use)
+static void io_queue_iowq(struct io_kiocb *req)
 {
 	struct io_kiocb *link = io_prep_linked_timeout(req);
 	struct io_uring_task *tctx = req->task->io_uring;
@@ -1505,7 +1505,7 @@ void io_req_task_submit(struct io_kiocb *req, struct io_tw_state *ts)
 	if (unlikely(req->task->flags & PF_EXITING))
 		io_req_defer_failed(req, -EFAULT);
 	else if (req->flags & REQ_F_FORCE_ASYNC)
-		io_queue_iowq(req, ts);
+		io_queue_iowq(req);
 	else
 		io_queue_sqe(req);
 }
@@ -2088,7 +2088,7 @@ static void io_queue_async(struct io_kiocb *req, int ret)
 		break;
 	case IO_APOLL_ABORTED:
 		io_kbuf_recycle(req, 0);
-		io_queue_iowq(req, NULL);
+		io_queue_iowq(req);
 		break;
 	case IO_APOLL_OK:
 		break;
@@ -2135,7 +2135,7 @@ static void io_queue_sqe_fallback(struct io_kiocb *req)
 		if (unlikely(req->ctx->drain_active))
 			io_drain_req(req);
 		else
-			io_queue_iowq(req, NULL);
+			io_queue_iowq(req);
 	}
 }
 
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index 6426ee382276..472ba5692ba8 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -79,7 +79,6 @@ struct file *io_file_get_fixed(struct io_kiocb *req, int fd,
 void __io_req_task_work_add(struct io_kiocb *req, unsigned flags);
 bool io_alloc_async_data(struct io_kiocb *req);
 void io_req_task_queue(struct io_kiocb *req);
-void io_queue_iowq(struct io_kiocb *req, struct io_tw_state *ts_dont_use);
 void io_req_task_complete(struct io_kiocb *req, struct io_tw_state *ts);
 void io_req_task_queue_fail(struct io_kiocb *req, int ret);
 void io_req_task_submit(struct io_kiocb *req, struct io_tw_state *ts);
diff --git a/io_uring/rw.c b/io_uring/rw.c
index 0585ebcc9773..576934dbf833 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -187,12 +187,6 @@ static inline loff_t *io_kiocb_update_pos(struct io_kiocb *req)
 	return NULL;
 }
 
-static void io_req_task_queue_reissue(struct io_kiocb *req)
-{
-	req->io_task_work.func = io_queue_iowq;
-	io_req_task_work_add(req);
-}
-
 #ifdef CONFIG_BLOCK
 static bool io_resubmit_prep(struct io_kiocb *req)
 {
@@ -405,7 +399,7 @@ static int kiocb_done(struct io_kiocb *req, ssize_t ret,
 	if (req->flags & REQ_F_REISSUE) {
 		req->flags &= ~REQ_F_REISSUE;
 		if (io_resubmit_prep(req))
-			io_req_task_queue_reissue(req);
+			return -EAGAIN;
 		else
 			io_req_task_queue_fail(req, final_ret);
 	}
-- 
2.44.0