[linux-2.6-block.git] / init / do_mounts_initrd.c

/*
 * Many of the syscalls used in this file expect some of the arguments
 * to be __user pointers not __kernel pointers.  To limit the sparse
 * noise, turn off sparse checking for this file.
 */
#ifdef __CHECKER__
#undef __CHECKER__
#warning "Sparse checking disabled for this file"
#endif

#include <linux/unistd.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/minix_fs.h>
#include <linux/romfs_fs.h>
#include <linux/initrd.h>
#include <linux/sched.h>
#include <linux/freezer.h>
#include <linux/kmod.h>

#include "do_mounts.h"

unsigned long initrd_start, initrd_end;
int initrd_below_start_ok;
unsigned int real_root_dev;	/* do_proc_dointvec cannot handle kdev_t */
static int __initdata mount_initrd = 1;

static int __init no_initrd(char *str)
{
	mount_initrd = 0;
	return 1;
}

__setup("noinitrd", no_initrd);

static int init_linuxrc(struct subprocess_info *info, struct cred *new)
{
	sys_unshare(CLONE_FS | CLONE_FILES);
	/* stdin/stdout/stderr for /linuxrc */
	sys_open("/dev/console", O_RDWR, 0);
	sys_dup(0);
	sys_dup(0);
	/* move initrd over / and chdir/chroot in initrd root */
	sys_chdir("/root");
	sys_mount(".", "/", NULL, MS_MOVE, NULL);
	sys_chroot(".");
	sys_setsid();
	return 0;
}

static void __init handle_initrd(void)
{
	struct subprocess_info *info;
	static char *argv[] = { "linuxrc", NULL, };
	extern char *envp_init[];
	int error;

	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);
	sys_chdir("/old");

	/* try loading default modules from initrd */
	load_default_modules();

	/*
	 * 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;

	info = call_usermodehelper_setup("/linuxrc", argv, envp_init,
					 GFP_KERNEL, init_linuxrc, NULL, NULL);
	if (!info)
		return;
	call_usermodehelper_exec(info, UMH_WAIT_PROC);

	current->flags &= ~PF_FREEZER_SKIP;

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

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

	sys_chdir("/");
	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");
	}
}

bool __init initrd_load(void)
{
	if (mount_initrd) {
		create_dev("/dev/ram", Root_RAM0);
		/*
		 * Load the initrd data into /dev/ram0. Execute it as initrd
		 * unless /dev/ram0 is supposed to be our actual root device,
		 * in that case the ram disk is just set up here, and gets
		 * mounted in the normal path.
		 */
		if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {
			sys_unlink("/initrd.image");
			handle_initrd();
			return true;
		}
	}
	sys_unlink("/initrd.image");
	return false;
}
Commit	Line	Data
c67e5382 HS	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
	10
1da177e4 LT	11	#include <linux/unistd.h>
	12	#include <linux/kernel.h>
	13	#include <linux/fs.h>
	14	#include <linux/minix_fs.h>
1da177e4 LT	15	#include <linux/romfs_fs.h>
	16	#include <linux/initrd.h>
	17	#include <linux/sched.h>
7dfb7103	18	#include <linux/freezer.h>
ba4df280	19	#include <linux/kmod.h>
1da177e4 LT	20
	21	#include "do_mounts.h"
	22
	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 */
1da177e4 LT	26	static int __initdata mount_initrd = 1;
	27
	28	static int __init no_initrd(char *str)
	29	{
	30	mount_initrd = 0;
	31	return 1;
	32	}
	33
	34	__setup("noinitrd", no_initrd);
	35
ba4df280	36	static int init_linuxrc(struct subprocess_info info, struct cred new)
1da177e4	37	{
ba4df280	38	sys_unshare(CLONE_FS \| CLONE_FILES);
43b16820 AV	39	/* stdin/stdout/stderr for /linuxrc */
	40	sys_open("/dev/console", O_RDWR, 0);
	41	sys_dup(0);
	42	sys_dup(0);
ba4df280 AV	43	/* move initrd over / and chdir/chroot in initrd root */
	44	sys_chdir("/root");
	45	sys_mount(".", "/", NULL, MS_MOVE, NULL);
	46	sys_chroot(".");
1da177e4	47	sys_setsid();
ba4df280	48	return 0;
1da177e4 LT	49	}
	50
	51	static void __init handle_initrd(void)
	52	{
907ed132	53	struct subprocess_info *info;
ba4df280 AV	54	static char *argv[] = { "linuxrc", NULL, };
ba4df280 AV	55	extern char *envp_init[];
1da177e4	56	int error;
1da177e4 LT	57
1da177e4 LT	58	real_root_dev = new_encode_dev(ROOT_DEV);
bdaf8529	59	create_dev("/dev/root.old", Root_RAM0);
1da177e4 LT	60	/* mount initrd on rootfs' /root */
	61	mount_block_root("/dev/root.old", root_mountflags & ~MS_RDONLY);
	62	sys_mkdir("/old", 0700);
ba4df280	63	sys_chdir("/old");
1da177e4	64
bb813f4c TH	65	/* try loading default modules from initrd */
	66	load_default_modules();
	67
8baabde6 RW	68	/*
	69	* In case that a resume from disk is carried out by linuxrc or one of
	70	* its children, we need to tell the freezer not to wait for us.
	71	*/
	72	current->flags \|= PF_FREEZER_SKIP;
	73
907ed132 LDM	74	info = call_usermodehelper_setup("/linuxrc", argv, envp_init,
	75	GFP_KERNEL, init_linuxrc, NULL, NULL);
	76	if (!info)
	77	return;
	78	call_usermodehelper_exec(info, UMH_WAIT_PROC);
8baabde6 RW	79
8baabde6 RW	80	current->flags &= ~PF_FREEZER_SKIP;
1da177e4 LT	81
1da177e4 LT	82	/* move initrd to rootfs' /old */
ba4df280	83	sys_mount("..", ".", NULL, MS_MOVE, NULL);
1da177e4	84	/* switch root and cwd back to / of rootfs */
ba4df280	85	sys_chroot("..");
1da177e4 LT	86
	87	if (new_decode_dev(real_root_dev) == Root_RAM0) {
	88	sys_chdir("/old");
	89	return;
	90	}
	91
ba4df280	92	sys_chdir("/");
1da177e4 LT	93	ROOT_DEV = new_decode_dev(real_root_dev);
	94	mount_root();
	95
	96	printk(KERN_NOTICE "Trying to move old root to /initrd ... ");
	97	error = sys_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL);
	98	if (!error)
	99	printk("okay\n");
	100	else {
	101	int fd = sys_open("/dev/root.old", O_RDWR, 0);
f220ab2a JL	102	if (error == -ENOENT)
	103	printk("/initrd does not exist. Ignored.\n");
	104	else
	105	printk("failed\n");
1da177e4 LT	106	printk(KERN_NOTICE "Unmounting old root\n");
	107	sys_umount("/old", MNT_DETACH);
	108	printk(KERN_NOTICE "Trying to free ramdisk memory ... ");
	109	if (fd < 0) {
	110	error = fd;
	111	} else {
	112	error = sys_ioctl(fd, BLKFLSBUF, 0);
	113	sys_close(fd);
	114	}
	115	printk(!error ? "okay\n" : "failed\n");
	116	}
	117	}
	118
f057f3b2	119	bool __init initrd_load(void)
1da177e4 LT	120	{
1da177e4 LT	121	if (mount_initrd) {
bdaf8529	122	create_dev("/dev/ram", Root_RAM0);
1da177e4 LT	123	/*
	124	* Load the initrd data into /dev/ram0. Execute it as initrd
	125	* unless /dev/ram0 is supposed to be our actual root device,
	126	* in that case the ram disk is just set up here, and gets
	127	* mounted in the normal path.
	128	*/
	129	if (rd_load_image("/initrd.image") && ROOT_DEV != Root_RAM0) {
	130	sys_unlink("/initrd.image");
	131	handle_initrd();
f057f3b2	132	return true;
1da177e4 LT	133	}
	134	}
	135	sys_unlink("/initrd.image");
f057f3b2	136	return false;
1da177e4	137	}