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 13 unsigned long initrd_start, initrd_end; 14 int initrd_below_start_ok; 15 unsigned int real_root_dev; /* do_proc_dointvec cannot handle kdev_t */ 16 static int __initdata old_fd, root_fd; 17 static int __initdata mount_initrd = 1; 18 19 static int __init no_initrd(char *str) 20 { 21 mount_initrd = 0; 22 return 1; 23 } 24 25 __setup("noinitrd", no_initrd); 26 27 static 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 38 static 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 } 107 108 int __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