diff mbox series

[1/3] io_uring: Add REQ_F_CQE_SKIP support for io_uring zerocopy

Message ID b1a047a1b2d55c1c245a78ca9772c31a9b3ceb12.1712268605.git.ozlinuxc@gmail.com
State New
Headers show
Series [1/3] io_uring: Add REQ_F_CQE_SKIP support for io_uring zerocopy | expand

Commit Message

Oliver Crumrine April 4, 2024, 10:17 p.m. UTC 
In his patch to enable zerocopy networking for io_uring, Pavel Begunkov
specifically disabled REQ_F_CQE_SKIP, as (at least from my
understanding) the userspace program wouldn't receive the
IORING_CQE_F_MORE flag in the result value.

To fix this, instead of keeping track of how many CQEs have been
received, and subtracting notifs from that, programs can keep track of
how many SQEs they have issued, and if a CQE is returned with an error,
they can simply subtract from how many notifs they expect to receive.

Signed-off-by: Oliver Crumrine <ozlinuxc@gmail.com>
---
 io_uring/net.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/io_uring/net.c b/io_uring/net.c
index 1e7665ff6ef7..822f49809b68 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -1044,9 +1044,6 @@  int io_send_zc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 
 	if (unlikely(READ_ONCE(sqe->__pad2[0]) || READ_ONCE(sqe->addr3)))
 		return -EINVAL;
-	/* we don't support IOSQE_CQE_SKIP_SUCCESS just yet */
-	if (req->flags & REQ_F_CQE_SKIP)
-		return -EINVAL;
 
 	notif = zc->notif = io_alloc_notif(ctx);
 	if (!notif)
@@ -1342,7 +1339,8 @@  void io_sendrecv_fail(struct io_kiocb *req)
 		req->cqe.res = sr->done_io;
 
 	if ((req->flags & REQ_F_NEED_CLEANUP) &&
-	    (req->opcode == IORING_OP_SEND_ZC || req->opcode == IORING_OP_SENDMSG_ZC))
+	    (req->opcode == IORING_OP_SEND_ZC || req->opcode == IORING_OP_SENDMSG_ZC) &&
+	    !(req->flags & REQ_F_CQE_SKIP))
 		req->cqe.flags |= IORING_CQE_F_MORE;
 }