os_set_fd_block
err = os_set_fd_block(fd, 0);
err = os_set_fd_block(chan->fd_out, 1);
err = os_set_fd_block(*fd_out, 0);
os_set_fd_block(req->originating_fd, 1);
os_set_fd_block(req->originating_fd, 0);
if (os_set_fd_block(sock, 0))
err = os_set_fd_block(fd, 0);
err = os_set_fd_block(*fd_out, 0);
err |= os_set_fd_block(kernel_fd, 0);
err = os_set_fd_block(fd, 0);
err = os_set_fd_block(new, 0);
extern int os_set_fd_block(int fd, int blocking);
EXPORT_SYMBOL(os_set_fd_block);