Subject: [PATCH 5/5] io_uring: mark us with IORING_FEAT_SUBMIT_STABLE

From: Jens Axboe <[email-masked]>
Date: Mon, 2 Dec 2019 19:54:44 -0700

If this flag is set, applications can be certain that any data for
async offload has been consumed when the kernel has consumed the
SQE.

Signed-off-by: Jens Axboe <[email-masked]>
---
 fs/io_uring.c                 | 3 ++-
 include/uapi/linux/io_uring.h | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index d5cd338ac8bf..cc3bfa13a1f3 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -5063,7 +5063,8 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p)
 	if (ret < 0)
 		goto err;
 
-	p->features = IORING_FEAT_SINGLE_MMAP | IORING_FEAT_NODROP;
+	p->features = IORING_FEAT_SINGLE_MMAP | IORING_FEAT_NODROP |
+			IORING_FEAT_SUBMIT_STABLE;
 	trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags);
 	return ret;
 err:
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 4637ed1d9949..eabccb46edd1 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -157,6 +157,7 @@ struct io_uring_params {
  */
 #define IORING_FEAT_SINGLE_MMAP		(1U << 0)
 #define IORING_FEAT_NODROP		(1U << 1)
+#define IORING_FEAT_SUBMIT_STABLE	(1U << 2)
 
 /*
  * io_uring_register(2) opcodes and arguments
-- 
2.24.0