[PATCH 0/3] __io_queue_sqe() cleanups

[PATCH 0/3] __io_queue_sqe() cleanups

[Pavel Begunkov]

Refactor __io_queue_sqe(). Easier to read, hopefully better optimisable.

Pavel Begunkov (3):
  io_uring: don't miss setting IO_WQ_WORK_CONCURRENT
  io_uring: simplify nxt propagation in io_queue_sqe
  io_uring: simplify __io_queue_sqe()

 fs/io_uring.c | 42 ++++++++++++++----------------------------
 1 file changed, 14 insertions(+), 28 deletions(-)

-- 
2.24.0

[PATCH 1/3] io_uring: don't miss setting IO_WQ_WORK_CONCURRENT

[Pavel Begunkov]

Set IO_WQ_WORK_CONCURRENT for all REQ_F_FORCE_ASYNC requests, do that in
that is also looks better.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 fs/io_uring.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 8e48e47906ba..9aeaa6f4a593 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1362,6 +1362,9 @@ static void io_prep_async_work(struct io_kiocb *req)
 	io_req_init_async(req);
 	id = req->work.identity;
 
+	if (req->flags & REQ_F_FORCE_ASYNC)
+		req->work.flags |= IO_WQ_WORK_CONCURRENT;
+
 	if (req->flags & REQ_F_ISREG) {
 		if (def->hash_reg_file || (ctx->flags & IORING_SETUP_IOPOLL))
 			io_wq_hash_work(&req->work, file_inode(req->file));
@@ -6265,13 +6268,6 @@ static void io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 			if (unlikely(ret))
 				goto fail_req;
 		}
-
-		/*
-		 * Never try inline submit of IOSQE_ASYNC is set, go straight
-		 * to async execution.
-		 */
-		io_req_init_async(req);
-		req->work.flags |= IO_WQ_WORK_CONCURRENT;
 		io_queue_async_work(req);
 	} else {
 		if (sqe) {
-- 
2.24.0

[PATCH 2/3] io_uring: simplify nxt propagation in io_queue_sqe

[Pavel Begunkov]

Don't overuse goto's, complex control flow doesn't make compilers happy
and makes code harder to read.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 fs/io_uring.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 9aeaa6f4a593..05b30212d9e6 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -6208,7 +6208,6 @@ static void __io_queue_sqe(struct io_kiocb *req, struct io_comp_state *cs)
 	 */
 	if (ret == -EAGAIN && !(req->flags & REQ_F_NOWAIT)) {
 		if (!io_arm_poll_handler(req)) {
-punt:
 			/*
 			 * Queued up for async execution, worker will release
 			 * submit reference when the iocb is actually submitted.
@@ -6237,12 +6236,9 @@ static void __io_queue_sqe(struct io_kiocb *req, struct io_comp_state *cs)
 
 	if (nxt) {
 		req = nxt;
-
-		if (req->flags & REQ_F_FORCE_ASYNC) {
-			linked_timeout = NULL;
-			goto punt;
-		}
-		goto again;
+		if (!(req->flags & REQ_F_FORCE_ASYNC))
+			goto again;
+		io_queue_async_work(req);
 	}
 exit:
 	if (old_creds)
-- 
2.24.0

[PATCH 3/3] io_uring: simplify __io_queue_sqe()

[Pavel Begunkov]

Restructure __io_queue_sqe() so it follows simple if/else if/else
control flow. It's more readable and removes extra goto/labels.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 fs/io_uring.c | 28 +++++++++++-----------------
 1 file changed, 11 insertions(+), 17 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 05b30212d9e6..754363ff3ad6 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -6182,7 +6182,6 @@ static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req)
 static void __io_queue_sqe(struct io_kiocb *req, struct io_comp_state *cs)
 {
 	struct io_kiocb *linked_timeout;
-	struct io_kiocb *nxt;
 	const struct cred *old_creds = NULL;
 	int ret;
 
@@ -6217,30 +6216,25 @@ static void __io_queue_sqe(struct io_kiocb *req, struct io_comp_state *cs)
 
 		if (linked_timeout)
 			io_queue_linked_timeout(linked_timeout);
-		goto exit;
-	}
+	} else if (likely(!ret)) {
+		/* drop submission reference */
+		req = io_put_req_find_next(req);
+		if (linked_timeout)
+			io_queue_linked_timeout(linked_timeout);
 
-	if (unlikely(ret)) {
+		if (req) {
+			if (!(req->flags & REQ_F_FORCE_ASYNC))
+				goto again;
+			io_queue_async_work(req);
+		}
+	} else {
 		/* un-prep timeout, so it'll be killed as any other linked */
 		req->flags &= ~REQ_F_LINK_TIMEOUT;
 		req_set_fail_links(req);
 		io_put_req(req);
 		io_req_complete(req, ret);
-		goto exit;
 	}
 
-	/* drop submission reference */
-	nxt = io_put_req_find_next(req);
-	if (linked_timeout)
-		io_queue_linked_timeout(linked_timeout);
-
-	if (nxt) {
-		req = nxt;
-		if (!(req->flags & REQ_F_FORCE_ASYNC))
-			goto again;
-		io_queue_async_work(req);
-	}
-exit:
 	if (old_creds)
 		revert_creds(old_creds);
 }
-- 
2.24.0