nop.c

 1// SPDX-License-Identifier: GPL-2.0
 2#include <linux/kernel.h>
 3#include <linux/errno.h>
 4#include <linux/fs.h>
 5#include <linux/file.h>
 6#include <linux/io_uring.h>
 7
 8#include <uapi/linux/io_uring.h>
 9
10#include "io_uring.h"
11#include "rsrc.h"
12#include "nop.h"
13
14struct io_nop {
15	/* NOTE: kiocb has the file as the first member, so don't do it here */
16	struct file     *file;
17	int             result;
18	int		fd;
19	unsigned int	flags;
20	__u64		extra1;
21	__u64		extra2;
22};
23
24#define NOP_FLAGS	(IORING_NOP_INJECT_RESULT | IORING_NOP_FIXED_FILE | \
25			 IORING_NOP_FIXED_BUFFER | IORING_NOP_FILE | \
26			 IORING_NOP_TW | IORING_NOP_CQE32)
27
28int io_nop_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
29{
30	struct io_nop *nop = io_kiocb_to_cmd(req, struct io_nop);
31
32	nop->flags = READ_ONCE(sqe->nop_flags);
33	if (nop->flags & ~NOP_FLAGS)
34		return -EINVAL;
35
36	if (nop->flags & IORING_NOP_INJECT_RESULT)
37		nop->result = READ_ONCE(sqe->len);
38	else
39		nop->result = 0;
40	if (nop->flags & IORING_NOP_FILE)
41		nop->fd = READ_ONCE(sqe->fd);
42	else
43		nop->fd = -1;
44	if (nop->flags & IORING_NOP_FIXED_BUFFER)
45		req->buf_index = READ_ONCE(sqe->buf_index);
46	if (nop->flags & IORING_NOP_CQE32) {
47		struct io_ring_ctx *ctx = req->ctx;
48
49		if (!(ctx->flags & (IORING_SETUP_CQE32|IORING_SETUP_CQE_MIXED)))
50			return -EINVAL;
51		nop->extra1 = READ_ONCE(sqe->off);
52		nop->extra2 = READ_ONCE(sqe->addr);
53	}
54	return 0;
55}
56
57int io_nop(struct io_kiocb *req, unsigned int issue_flags)
58{
59	struct io_nop *nop = io_kiocb_to_cmd(req, struct io_nop);
60	int ret = nop->result;
61
62	if (nop->flags & IORING_NOP_FILE) {
63		if (nop->flags & IORING_NOP_FIXED_FILE) {
64			req->file = io_file_get_fixed(req, nop->fd, issue_flags);
65			req->flags |= REQ_F_FIXED_FILE;
66		} else {
67			req->file = io_file_get_normal(req, nop->fd);
68		}
69		if (!req->file) {
70			ret = -EBADF;
71			goto done;
72		}
73	}
74	if (nop->flags & IORING_NOP_FIXED_BUFFER) {
75		if (!io_find_buf_node(req, issue_flags))
76			ret = -EFAULT;
77	}
78done:
79	if (ret < 0)
80		req_set_fail(req);
81	if (nop->flags & IORING_NOP_CQE32)
82		io_req_set_res32(req, nop->result, 0, nop->extra1, nop->extra2);
83	else
84		io_req_set_res(req, nop->result, 0);
85	if (nop->flags & IORING_NOP_TW) {
86		req->io_task_work.func = io_req_task_complete;
87		io_req_task_work_add(req);
88		return IOU_ISSUE_SKIP_COMPLETE;
89	}
90	return IOU_COMPLETE;
91}