Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / init / do_mounts_initrd.c
blob5e4ded51788eb81f277c0b5674f5602730220df4
1 /*
2 * Many of the syscalls used in this file expect some of the arguments
3 * to be __user pointers not __kernel pointers. To limit the sparse
4 * noise, turn off sparse checking for this file.
5 */
6 #ifdef __CHECKER__
7 #undef __CHECKER__
8 #warning "Sparse checking disabled for this file"
9 #endif
11 #include <linux/unistd.h>
12 #include <linux/kernel.h>
13 #include <linux/fs.h>
14 #include <linux/minix_fs.h>
15 #include <linux/romfs_fs.h>
16 #include <linux/initrd.h>
17 #include <linux/sched.h>
18 #include <linux/freezer.h>
19 #include <linux/kmod.h>
21 #include "do_mounts.h"
23 unsigned long initrd_start, initrd_end;
24 int initrd_below_start_ok;
25 unsigned int real_root_dev; /* do_proc_dointvec cannot handle kdev_t */
26 static int __initdata mount_initrd = 1;
28 static int __init no_initrd(char *str)
30 mount_initrd = 0;
31 return 1;
34 __setup("noinitrd", no_initrd);
36 static int init_linuxrc(struct subprocess_info *info, struct cred *new)
38 sys_unshare(CLONE_FS | CLONE_FILES);
39 /* move initrd over / and chdir/chroot in initrd root */
40 sys_chdir("/root");
41 sys_mount(".", "/", NULL, MS_MOVE, NULL);
42 sys_chroot(".");
43 sys_setsid();
44 return 0;
47 static void __init handle_initrd(void)
49 static char *argv[] = { "linuxrc", NULL, };
50 extern char *envp_init[];
51 int error;
53 real_root_dev = new_encode_dev(ROOT_DEV);
54 create_dev("/dev/root.old", Root_RAM0);
55 /* mount initrd on rootfs' /root */
56 mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
57 sys_mkdir("/old", 0700);
58 sys_chdir("/old");
61 * In case that a resume from disk is carried out by linuxrc or one of
62 * its children, we need to tell the freezer not to wait for us.
64 current->flags |= PF_FREEZER_SKIP;
66 call_usermodehelper_fns("/linuxrc", argv, envp_init, UMH_WAIT_PROC,
67 init_linuxrc, NULL, NULL);
69 current->flags &= ~PF_FREEZER_SKIP;
71 /* move initrd to rootfs' /old */
72 sys_mount("..", ".", NULL, MS_MOVE, NULL);
73 /* switch root and cwd back to / of rootfs */
74 sys_chroot("..");
76 if (new_decode_dev(real_root_dev) == Root_RAM0) {
77 sys_chdir("/old");
78 return;
81 sys_chdir("/");
82 ROOT_DEV = new_decode_dev(real_root_dev);
83 mount_root();
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);
104 printk(!error ? "okay\n" : "failed\n");
108 int __init initrd_load(void)
110 if (mount_initrd) {
111 create_dev("/dev/ram", Root_RAM0);
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.
118 if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {
119 sys_unlink("/initrd.image");
120 handle_initrd();
121 return 1;
124 sys_unlink("/initrd.image");
125 return 0;