1#include <linux/unistd.h>
2#include <linux/kernel.h>
3#include <linux/fs.h>
4#include <linux/minix_fs.h>
5#include <linux/ext2_fs.h>
6#include <linux/romfs_fs.h>
7#include <linux/initrd.h>
8#include <linux/sched.h>
9#include <linux/freezer.h>
10
11#include "do_mounts.h"
12
13unsigned long initrd_start, initrd_end;
14int initrd_below_start_ok;
15unsigned int real_root_dev;	/* do_proc_dointvec cannot handle kdev_t */
16static int __initdata old_fd, root_fd;
17static int __initdata mount_initrd = 1;
18
19static int __init no_initrd(char *str)
20{
21	mount_initrd = 0;
22	return 1;
23}
24
25__setup("noinitrd", no_initrd);
26
27static int __init do_linuxrc(void *_shell)
28{
29	static const char *argv[] = { "linuxrc", NULL, };
30	extern const char *envp_init[];
31	const char *shell = _shell;
32
33	sys_close(old_fd);sys_close(root_fd);
34	sys_setsid();
35	return kernel_execve(shell, argv, envp_init);
36}
37
38static void __init handle_initrd(void)
39{
40	int error;
41	int pid;
42
43	real_root_dev = new_encode_dev(ROOT_DEV);
44	create_dev("/dev/root.old", Root_RAM0);
45	/* mount initrd on rootfs' /root */
46	mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
47	sys_mkdir("/old", 0700);
48	root_fd = sys_open("/", 0, 0);
49	old_fd = sys_open("/old", 0, 0);
50	/* move initrd over / and chdir/chroot in initrd root */
51	sys_chdir("/root");
52	sys_mount(".", "/", NULL, MS_MOVE, NULL);
53	sys_chroot(".");
54
55	/*
56	 * In case that a resume from disk is carried out by linuxrc or one of
57	 * its children, we need to tell the freezer not to wait for us.
58	 */
59	current->flags |= PF_FREEZER_SKIP;
60
61	pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
62	if (pid > 0)
63		while (pid != sys_wait4(-1, NULL, 0, NULL))
64			yield();
65
66	current->flags &= ~PF_FREEZER_SKIP;
67
68	/* move initrd to rootfs' /old */
69	sys_fchdir(old_fd);
70	sys_mount("/", ".", NULL, MS_MOVE, NULL);
71	/* switch root and cwd back to / of rootfs */
72	sys_fchdir(root_fd);
73	sys_chroot(".");
74	sys_close(old_fd);
75	sys_close(root_fd);
76
77	if (new_decode_dev(real_root_dev) == Root_RAM0) {
78		sys_chdir("/old");
79		return;
80	}
81
82	ROOT_DEV = new_decode_dev(real_root_dev);
83	mount_root();
84
85	printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
86	error = sys_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);
87	if (!error)
88		printk("okay\n");
89	else {
90		int fd = sys_open("/dev/root.old", O_RDWR, 0);
91		if (error == -ENOENT)
92			printk("/initrd does not exist. Ignored.\n");
93		else
94			printk("failed\n");
95		printk(KERN_NOTICE "Unmounting old root\n");
96		sys_umount("/old", MNT_DETACH);
97		printk(KERN_NOTICE "Trying to free ramdisk memory ... ");
98		if (fd < 0) {
99			error = fd;
100		} else {
101			error = sys_ioctl(fd, BLKFLSBUF, 0);
102			sys_close(fd);
103		}
104		printk(!error ? "okay\n" : "failed\n");
105	}
106}
107
108int __init initrd_load(void)
109{
110	if (mount_initrd) {
111		create_dev("/dev/ram", Root_RAM0);
112		/*
113		 * Load the initrd data into /dev/ram0. Execute it as initrd
114		 * unless /dev/ram0 is supposed to be our actual root device,
115		 * in that case the ram disk is just set up here, and gets
116		 * mounted in the normal path.
117		 */
118		if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {
119			sys_unlink("/initrd.image");
120			handle_initrd();
121			return 1;
122		}
123	}
124	sys_unlink("/initrd.image");
125	return 0;
126}
127