static void __init handle_initrd(void)
{
	int error;
	int pid;

	real_root_dev = new_encode_dev(ROOT_DEV);
	create_dev("/dev/root.old", Root_RAM0);
	/* mount initrd on rootfs' /root */
	mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
	sys_mkdir((const char __user *)"/old", 0700);
	root_fd = sys_open((const char __user *)"/", 0, 0);
	old_fd = sys_open((const char __user *)"/old", 0, 0);
	/* move initrd over / and chdir/chroot in initrd root */
	sys_chdir((const char __user *)"/root");
	sys_mount((char __user *)".", (char __user *)"/", NULL, MS_MOVE, NULL);
	sys_chroot((const char __user *)".");

	/*
	 * In case that a resume from disk is carried out by linuxrc or one of
	 * its children, we need to tell the freezer not to wait for us.
	 */
	current->flags |= PF_FREEZER_SKIP;

	pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
	if (pid > 0)
		while (pid != sys_wait4(-1, NULL, 0, NULL))
			yield();

	current->flags &= ~PF_FREEZER_SKIP;

	/* move initrd to rootfs' /old */
	sys_fchdir(old_fd);
	sys_mount((char __user *)"/", (char __user *)".", NULL, MS_MOVE, NULL);
	/* switch root and cwd back to / of rootfs */
	sys_fchdir(root_fd);
	sys_chroot((const char __user *)".");
	sys_close(old_fd);
	sys_close(root_fd);

	if (new_decode_dev(real_root_dev) == Root_RAM0) {
		sys_chdir((const char __user *)"/old");
		return;
	}

	ROOT_DEV = new_decode_dev(real_root_dev);
	mount_root();

	printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
	error = sys_mount((char __user *)"/old", (char __user *)"/root/initrd", NULL, MS_MOVE, NULL);
	if (!error)
		printk("okay\n");
	else {
		int fd = sys_open((const char __user *)"/dev/root.old", O_RDWR, 0);
		if (error == -ENOENT)
			printk("/initrd does not exist. Ignored.\n");
		else
			printk("failed\n");
		printk(KERN_NOTICE "Unmounting old root\n");
		sys_umount((char __user *)"/old", MNT_DETACH);
		printk(KERN_NOTICE "Trying to free ramdisk memory ... ");
		if (fd < 0) {
			error = fd;
		} else {
			error = sys_ioctl(fd, BLKFLSBUF, 0);
			sys_close(fd);
		}
		printk(!error ? "okay\n" : "failed\n");
	}
}
Esempio n. 2
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static void __init handle_initrd(void)
{
	int error;
	int pid;

	real_root_dev = new_encode_dev(ROOT_DEV);
	create_dev("/dev/root.old", Root_RAM0);
	/* mount initrd on rootfs' /root */
	mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
	sys_mkdir("/old", 0700);
	root_fd = sys_open("/", 0, 0);
	old_fd = sys_open("/old", 0, 0);
	/* move initrd over / and chdir/chroot in initrd root */
	sys_chdir("/root");
	sys_mount(".", "/", NULL, MS_MOVE, NULL);
	sys_chroot(".");

	pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
	if (pid > 0) {
		while (pid != sys_wait4(-1, NULL, 0, NULL)) {
			try_to_freeze();
			yield();
		}
	}

	/* move initrd to rootfs' /old */
	sys_fchdir(old_fd);
	sys_mount("/", ".", NULL, MS_MOVE, NULL);
	/* switch root and cwd back to / of rootfs */
	sys_fchdir(root_fd);
	sys_chroot(".");
	sys_close(old_fd);
	sys_close(root_fd);

	if (new_decode_dev(real_root_dev) == Root_RAM0) {
		sys_chdir("/old");
		return;
	}

	ROOT_DEV = new_decode_dev(real_root_dev);
	mount_root();

	printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
	error = sys_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);
	if (!error)
		printk("okay\n");
	else {
		int fd = sys_open("/dev/root.old", O_RDWR, 0);
		if (error == -ENOENT)
			printk("/initrd does not exist. Ignored.\n");
		else
			printk("failed\n");
		printk(KERN_NOTICE "Unmounting old root\n");
		sys_umount("/old", MNT_DETACH);
		printk(KERN_NOTICE "Trying to free ramdisk memory ... ");
		if (fd < 0) {
			error = fd;
		} else {
			error = sys_ioctl(fd, BLKFLSBUF, 0);
			sys_close(fd);
		}
		printk(!error ? "okay\n" : "failed\n");
	}
}