From: Jens Axboe <axboe@kernel.dk>
Date: Wed, 16 Jan 2019 05:06:05 +0000 (-0700)
Subject: engines/io_uring: ensure sqe stores are ordered SQ ring tail update
X-Git-Tag: fio-3.13~14
X-Git-Url: https://git.kernel.dk/?p=fio.git;a=commitdiff_plain;h=2b9415ddc260726c3ea9ae3436826f9181811143

engines/io_uring: ensure sqe stores are ordered SQ ring tail update

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/engines/io_uring.c b/engines/io_uring.c
index 56af8d71..8c5d9deb 100644
--- a/engines/io_uring.c
+++ b/engines/io_uring.c
@@ -289,6 +289,8 @@ static enum fio_q_status fio_ioring_queue(struct thread_data *td,
 	if (next_tail == *ring->head)
 		return FIO_Q_BUSY;
 
+	/* ensure sqe stores are ordered with tail update */
+	write_barrier();
 	ring->array[tail & ld->sq_ring_mask] = io_u->index;
 	*ring->tail = next_tail;
 	write_barrier();