From: Jens Axboe axboe@kernel.dk
mainline inclusion from mainline-5.6-rc1 commit ce35a47a3a0208a77b4d31b7f2e8ed57d624093d category: feature bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=27 CVE: NA ---------------------------
io_uring defaults to always doing inline submissions, if at all possible. But for larger copies, even if the data is fully cached, that can take a long time. Add an IOSQE_ASYNC flag that the application can set on the SQE - if set, it'll ensure that we always go async for those kinds of requests. Use the io-wq IO_WQ_WORK_CONCURRENT flag to ensure we get the concurrency we desire for this case.
Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: yangerkun yangerkun@huawei.com Reviewed-by: zhangyi (F) yi.zhang@huawei.com Signed-off-by: Cheng Jian cj.chengjian@huawei.com --- fs/io_uring.c | 16 ++++++++++++++-- include/uapi/linux/io_uring.h | 1 + 2 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c index b8e5b742a00a..29d67e40e81d 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -483,6 +483,7 @@ struct io_kiocb { #define REQ_F_INFLIGHT 16384 /* on inflight list */ #define REQ_F_COMP_LOCKED 32768 /* completion under lock */ #define REQ_F_HARDLINK 65536 /* doesn't sever on completion < 0 */ +#define REQ_F_FORCE_ASYNC 131072 /* IOSQE_ASYNC */ u64 user_data; u32 result; u32 sequence; @@ -4014,8 +4015,17 @@ static void io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe) req_set_fail_links(req); io_double_put_req(req); } - } else + } else if ((req->flags & REQ_F_FORCE_ASYNC) && + !io_wq_current_is_worker()) { + /* + * Never try inline submit of IOSQE_ASYNC is set, go straight + * to async execution. + */ + req->work.flags |= IO_WQ_WORK_CONCURRENT; + io_queue_async_work(req); + } else { __io_queue_sqe(req, sqe); + } }
static inline void io_queue_link_head(struct io_kiocb *req) @@ -4028,7 +4038,7 @@ static inline void io_queue_link_head(struct io_kiocb *req) }
#define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK| \ - IOSQE_IO_HARDLINK) + IOSQE_IO_HARDLINK | IOSQE_ASYNC)
static bool io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, struct io_submit_state *state, struct io_kiocb **link) @@ -4041,6 +4051,8 @@ static bool io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, ret = -EINVAL; goto err_req; } + if (sqe->flags & IOSQE_ASYNC) + req->flags |= REQ_F_FORCE_ASYNC;
ret = io_req_set_file(state, req, sqe); if (unlikely(ret)) { diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 3f45f7c543de..d7ec50247a3a 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -51,6 +51,7 @@ struct io_uring_sqe { #define IOSQE_IO_DRAIN (1U << 1) /* issue after inflight IO */ #define IOSQE_IO_LINK (1U << 2) /* links next sqe */ #define IOSQE_IO_HARDLINK (1U << 3) /* like LINK, but stronger */ +#define IOSQE_ASYNC (1U << 4) /* always go async */
/* * io_uring_setup() flags