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