Commit a85f3105 authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring/nop: add support for testing registered files and buffers 



Useful for testing performance/efficiency impact of registered files
and buffers, vs (particularly) non-registered files.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent aa00f67a

include/uapi/linux/io_uring.h

+3 −0
Original line number Diff line number Diff line
@@ -416,6 +416,9 @@ enum io_uring_msg_ring_flags { 
 * IORING_NOP_INJECT_RESULT	Inject result from sqe->result

 */

#define IORING_NOP_INJECT_RESULT	(1U << 0)

#define IORING_NOP_FILE			(1U << 1)

#define IORING_NOP_FIXED_FILE		(1U << 2)

#define IORING_NOP_FIXED_BUFFER		(1U << 3)



/*

 * IO completion data structure (Completion Queue Entry)

io_uring/nop.c

+44 −5
Original line number Diff line number Diff line
@@ -8,35 +8,74 @@ 
#include <uapi/linux/io_uring.h>



#include "io_uring.h"

#include "rsrc.h"

#include "nop.h"



struct io_nop {

	/* NOTE: kiocb has the file as the first member, so don't do it here */

	struct file     *file;

	int             result;

	int		fd;

	int		buffer;

	unsigned int	flags;

};



#define NOP_FLAGS	(IORING_NOP_INJECT_RESULT | IORING_NOP_FIXED_FILE | \

			 IORING_NOP_FIXED_BUFFER | IORING_NOP_FILE)



int io_nop_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)

{

	unsigned int flags;

	struct io_nop *nop = io_kiocb_to_cmd(req, struct io_nop);



	flags = READ_ONCE(sqe->nop_flags);

	if (flags & ~IORING_NOP_INJECT_RESULT)

	nop->flags = READ_ONCE(sqe->nop_flags);

	if (nop->flags & ~NOP_FLAGS)

		return -EINVAL;



	if (flags & IORING_NOP_INJECT_RESULT)

	if (nop->flags & IORING_NOP_INJECT_RESULT)

		nop->result = READ_ONCE(sqe->len);

	else

		nop->result = 0;

	if (nop->flags & IORING_NOP_FIXED_FILE)

		nop->fd = READ_ONCE(sqe->fd);

	if (nop->flags & IORING_NOP_FIXED_BUFFER)

		nop->buffer = READ_ONCE(sqe->buf_index);

	return 0;

}



int io_nop(struct io_kiocb *req, unsigned int issue_flags)

{

	struct io_nop *nop = io_kiocb_to_cmd(req, struct io_nop);

	int ret = nop->result;



	if (nop->result < 0)

	if (nop->flags & IORING_NOP_FILE) {

		if (nop->flags & IORING_NOP_FIXED_FILE) {

			req->file = io_file_get_fixed(req, nop->fd, issue_flags);

			req->flags |= REQ_F_FIXED_FILE;

		} else {

			req->file = io_file_get_normal(req, nop->fd);

		}

		if (!req->file) {

			ret = -EBADF;

			goto done;

		}

	}

	if (nop->flags & IORING_NOP_FIXED_BUFFER) {

		struct io_ring_ctx *ctx = req->ctx;

		struct io_mapped_ubuf *imu;

		int idx;



		ret = -EFAULT;

		io_ring_submit_lock(ctx, issue_flags);

		if (nop->buffer < ctx->nr_user_bufs) {

			idx = array_index_nospec(nop->buffer, ctx->nr_user_bufs);

			imu = READ_ONCE(ctx->user_bufs[idx]);

			io_req_set_rsrc_node(req, ctx);

			ret = 0;

		}

		io_ring_submit_unlock(ctx, issue_flags);

	}

done:

	if (ret < 0)

		req_set_fail(req);

	io_req_set_res(req, nop->result, 0);

	return IOU_OK;