linux/io_uring/nop.c
Jens Axboe a85f31052b 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: Jens Axboe <axboe@kernel.dk>
2024-10-29 13:43:28 -06:00

83 lines
2.0 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/io_uring.h>
#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)
{
struct io_nop *nop = io_kiocb_to_cmd(req, struct io_nop);
nop->flags = READ_ONCE(sqe->nop_flags);
if (nop->flags & ~NOP_FLAGS)
return -EINVAL;
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->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;
}