static int open_one_chan(struct chan *chan)
{
int fd, err;
if (chan->opened)
return 0;
if (chan->ops->open == NULL)
fd = 0;
else fd = (*chan->ops->open)(chan->input, chan->output, chan->primary,
chan->data, &chan->dev);
if (fd < 0)
return fd;
err = os_set_fd_block(fd, 0);
if (err) {
(*chan->ops->close)(fd, chan->data);
return err;
}
chan->fd = fd;
chan->opened = 1;
return 0;
}
int start_io_thread(unsigned long sp, int *fd_out)
{
int pid, fds[2], err;
err = os_pipe(fds, 1, 1);
if(err < 0){
printk("start_io_thread - os_pipe failed, err = %d\n", -err);
goto out;
}
kernel_fd = fds[0];
*fd_out = fds[1];
err = os_set_fd_block(*fd_out, 0);
if (err) {
printk("start_io_thread - failed to set nonblocking I/O.\n");
goto out_close;
}
pid = clone(io_thread, (void *) sp, CLONE_FILES | CLONE_VM, NULL);
if(pid < 0){
err = -errno;
printk("start_io_thread - clone failed : errno = %d\n", errno);
goto out_close;
}
return(pid);
out_close:
os_close_file(fds[0]);
os_close_file(fds[1]);
kernel_fd = -1;
*fd_out = -1;
out:
return err;
}