Commit 5756a3a7 authored by Kanchan Joshi's avatar Kanchan Joshi Committed by Jens Axboe
Browse files

io_uring: add iopoll infrastructure for io_uring_cmd 



Put this up in the same way as iopoll is done for regular read/write IO.
Make place for storing a cookie into struct io_uring_cmd on submission.
Perform the completion using the ->uring_cmd_iopoll handler.

Signed-off-by: default avatarKanchan Joshi <joshi.k@samsung.com>
Signed-off-by: default avatarPankaj Raghav <p.raghav@samsung.com>
Link: https://lore.kernel.org/r/20220823161443.49436-3-joshi.k@samsung.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent de27e18e

include/linux/io_uring.h

+6 −2
Original line number Diff line number Diff line
@@ -20,8 +20,12 @@ enum io_uring_cmd_flags { 
struct io_uring_cmd {

	struct file	*file;

	const void	*cmd;

	union {

		/* callback to defer completions to task context */

		void (*task_work_cb)(struct io_uring_cmd *cmd);

		/* used for polled completion */

		void *cookie;

	};

	u32		cmd_op;

	u32		pad;

	u8		pdu[32]; /* available inline for free use */

io_uring/io_uring.c

+6 −0
Original line number Diff line number Diff line
@@ -1433,6 +1433,12 @@ static int io_iopoll_check(struct io_ring_ctx *ctx, long min) 
			    wq_list_empty(&ctx->iopoll_list))

				break;

		}



		if (task_work_pending(current)) {

			mutex_unlock(&ctx->uring_lock);

			io_run_task_work();

			mutex_lock(&ctx->uring_lock);

		}

		ret = io_do_iopoll(ctx, !min);

		if (ret < 0)

			break;

io_uring/opdef.c

+1 −0
Original line number Diff line number Diff line
@@ -465,6 +465,7 @@ const struct io_op_def io_op_defs[] = { 
		.needs_file		= 1,

		.plug			= 1,

		.name			= "URING_CMD",

		.iopoll			= 1,

		.async_size		= uring_cmd_pdu_size(1),

		.prep			= io_uring_cmd_prep,

		.issue			= io_uring_cmd,

io_uring/rw.c

+7 −1
Original line number Diff line number Diff line
@@ -1011,7 +1011,13 @@ int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin) 
		if (READ_ONCE(req->iopoll_completed))

			break;



		ret = rw->kiocb.ki_filp->f_op->iopoll(&rw->kiocb, &iob, poll_flags);

		if (req->opcode == IORING_OP_URING_CMD) {

			struct io_uring_cmd *ioucmd = (struct io_uring_cmd *)rw;



			ret = req->file->f_op->uring_cmd_iopoll(ioucmd);

		} else

			ret = rw->kiocb.ki_filp->f_op->iopoll(&rw->kiocb, &iob,

							poll_flags);

		if (unlikely(ret < 0))

			return ret;

		else if (ret)

io_uring/uring_cmd.c

+9 −2
Original line number Diff line number Diff line
@@ -50,6 +50,10 @@ void io_uring_cmd_done(struct io_uring_cmd *ioucmd, ssize_t ret, ssize_t res2) 
	io_req_set_res(req, ret, 0);

	if (req->ctx->flags & IORING_SETUP_CQE32)

		io_req_set_cqe32_extra(req, res2, 0);

	if (req->ctx->flags & IORING_SETUP_IOPOLL)

		/* order with io_iopoll_req_issued() checking ->iopoll_complete */

		smp_store_release(&req->iopoll_completed, 1);

	else

		__io_req_complete(req, 0);

}

EXPORT_SYMBOL_GPL(io_uring_cmd_done);
@@ -97,8 +101,11 @@ int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags) 
		issue_flags |= IO_URING_F_SQE128;

	if (ctx->flags & IORING_SETUP_CQE32)

		issue_flags |= IO_URING_F_CQE32;

	if (ctx->flags & IORING_SETUP_IOPOLL)

	if (ctx->flags & IORING_SETUP_IOPOLL) {

		issue_flags |= IO_URING_F_IOPOLL;

		req->iopoll_completed = 0;

		WRITE_ONCE(ioucmd->cookie, NULL);

	}



	if (req_has_async_data(req))

		ioucmd->cmd = req->async_data;