From de0617e467171ba44c73efd1ba63f101b164a035 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Sat, 6 Apr 2019 21:51:27 -0600 Subject: io_uring: add support for marking commands as draining There are no ordering constraints between the submission and completion side of io_uring. But sometimes that would be useful to have. One common example is doing an fsync, for instance, and have it ordered with previous writes. Without support for that, the application must do this tracking itself. This adds a general SQE flag, IOSQE_IO_DRAIN. If a command is marked with this flag, then it will not be issued before previous commands have completed, and subsequent commands submitted after the drain will not be issued before the drain is started.. If there are no pending commands, setting this flag will not change the behavior of the issue of the command. Signed-off-by: Jens Axboe --- include/uapi/linux/io_uring.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index e23408692118..a7a6384d0c70 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -38,6 +38,7 @@ struct io_uring_sqe { * sqe->flags */ #define IOSQE_FIXED_FILE (1U << 0) /* use fixed fileset */ +#define IOSQE_IO_DRAIN (1U << 1) /* issue after inflight IO */ /* * io_uring_setup() flags -- cgit v1.2.3