1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2016 Anton Ivanov (aivanov@brocade.com)
4 * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
5 * Copyright (C) 2001 Ridgerun,Inc (glonnon@ridgerun.com)
6 */
7
8#include <stddef.h>
9#include <unistd.h>
10#include <errno.h>
11#include <sched.h>
12#include <signal.h>
13#include <string.h>
14#include <netinet/in.h>
15#include <sys/time.h>
16#include <sys/socket.h>
17#include <sys/mman.h>
18#include <sys/param.h>
19#include <endian.h>
20#include <byteswap.h>
21
22#include "ubd.h"
23#include <os.h>
24#include <poll.h>
25
26struct pollfd kernel_pollfd;
27
28int start_io_thread(unsigned long sp, int *fd_out)
29{
30 int pid, fds[2], err;
31
32 err = os_pipe(fds, 1, 1);
33 if(err < 0){
34 printk("start_io_thread - os_pipe failed, err = %d\n", -err);
35 goto out;
36 }
37
38 kernel_fd = fds[0];
39 kernel_pollfd.fd = kernel_fd;
40 kernel_pollfd.events = POLLIN;
41 *fd_out = fds[1];
42
43 err = os_set_fd_block(*fd_out, 0);
44 err = os_set_fd_block(kernel_fd, 0);
45 if (err) {
46 printk("start_io_thread - failed to set nonblocking I/O.\n");
47 goto out_close;
48 }
49
50 pid = clone(io_thread, (void *) sp, CLONE_FILES | CLONE_VM, NULL);
51 if(pid < 0){
52 err = -errno;
53 printk("start_io_thread - clone failed : errno = %d\n", errno);
54 goto out_close;
55 }
56
57 return(pid);
58
59 out_close:
60 os_close_file(fds[0]);
61 os_close_file(fds[1]);
62 kernel_fd = -1;
63 *fd_out = -1;
64 out:
65 return err;
66}
67
68int ubd_read_poll(int timeout)
69{
70 kernel_pollfd.events = POLLIN;
71 return poll(&kernel_pollfd, 1, timeout);
72}
73int ubd_write_poll(int timeout)
74{
75 kernel_pollfd.events = POLLOUT;
76 return poll(&kernel_pollfd, 1, timeout);
77}
78
79

source code of linux/arch/um/drivers/ubd_user.c