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

Jens Axboe
2019-12-03T02:55:06Z

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 <axboe@kernel.dk>
---
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