arch/um/drivers/ubd_user.c

   1 /*
   2  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
   3  * Copyright (C) 2001 Ridgerun,Inc (glonnon@ridgerun.com)
   4  * Licensed under the GPL
   5  */
   6
   7 #include <stddef.h>
   8 #include <unistd.h>
   9 #include <errno.h>
  10 #include <sched.h>
  11 #include <signal.h>
  12 #include <string.h>
  13 #include <netinet/in.h>
  14 #include <sys/time.h>
  15 #include <sys/socket.h>
  16 #include <sys/mman.h>
  17 #include <sys/param.h>
  18 #include "asm/types.h"
  19 #include "ubd_user.h"
  20 #include "os.h"
  21 #include "cow.h"
  22
  23 #include <endian.h>
  24 #include <byteswap.h>
  25
  26 void ignore_sigwinch_sig(void)
  27 {
  28         signal(SIGWINCH, SIG_IGN);
  29 }
  30
  31 int start_io_thread(unsigned long sp, int *fd_out)
  32 {
  33         int pid, fds[2], err;
  34
  35         err = os_pipe(fds, 1, 1);
  36         if(err < 0){
  37                 printk("start_io_thread - os_pipe failed, err = %d\n", -err);
  38                 goto out;
  39         }
  40
  41         kernel_fd = fds[0];
  42         *fd_out = fds[1];
  43
  44         err = os_set_fd_block(*fd_out, 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 }