do_mounts.c

#include <linux/module.h>
#include <linux/sched.h>
#include <linux/ctype.h>
#include <linux/fd.h>
#include <linux/tty.h>
#include <linux/suspend.h>
#include <linux/root_dev.h>
#include <linux/security.h>
#include <linux/delay.h>
#include <linux/genhd.h>
#include <linux/mount.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/initrd.h>
#include <linux/async.h>
#include <linux/fs_struct.h>
#include <linux/slab.h>

#include <linux/nfs_fs.h>
#include <linux/nfs_fs_sb.h>
#include <linux/nfs_mount.h>

#include "do_mounts.h"

int __initdata rd_doload;	

int root_mountflags = MS_RDONLY | MS_SILENT;
static char * __initdata root_device_name;
static char __initdata saved_root_name[64];
static int root_wait;

dev_t ROOT_DEV;

static int __init load_ramdisk(char *str)
{
	rd_doload = simple_strtol(str,NULL,0) & 3;
	return 1;
}
__setup("load_ramdisk=", load_ramdisk);

static int __init readonly(char *str)
{
	if (*str)
		return 0;
	root_mountflags |= MS_RDONLY;
	return 1;
}

static int __init readwrite(char *str)
{
	if (*str)
		return 0;
	root_mountflags &= ~MS_RDONLY;
	return 1;
}

__setup("ro", readonly);
__setup("rw", readwrite);

#ifdef CONFIG_BLOCK
static int match_dev_by_uuid(struct device *dev, void *data)
{
	u8 *uuid = data;
	struct hd_struct *part = dev_to_part(dev);

	if (!part->info)
		goto no_match;

	if (memcmp(uuid, part->info->uuid, sizeof(part->info->uuid)))
			goto no_match;

	return 1;
no_match:
	return 0;
}


static dev_t devt_from_partuuid(char *uuid_str)
{
	dev_t res = 0;
	struct device *dev = NULL;
	u8 uuid[16];
	struct gendisk *disk;
	struct hd_struct *part;
	int offset = 0;

	if (strlen(uuid_str) < 36)
		goto done;

	
	if (uuid_str[36]) {
		char c = 0;
		
		if (sscanf(&uuid_str[36],
			   "/PARTNROFF=%d%c", &offset, &c) != 1) {
			printk(KERN_ERR "VFS: PARTUUID= is invalid.\n"
			 "Expected PARTUUID=<valid-uuid-id>[/PARTNROFF=%%d]\n");
			if (root_wait)
				printk(KERN_ERR
				     "Disabling rootwait; root= is invalid.\n");
			root_wait = 0;
			goto done;
		}
	}

	
	part_pack_uuid(uuid_str, uuid);

	dev = class_find_device(&block_class, NULL, uuid, &match_dev_by_uuid);
	if (!dev)
		goto done;

	res = dev->devt;

	
	if (!offset)
		goto no_offset;

	res = 0;
	disk = part_to_disk(dev_to_part(dev));
	part = disk_get_part(disk, dev_to_part(dev)->partno + offset);
	if (part) {
		res = part_devt(part);
		put_device(part_to_dev(part));
	}

no_offset:
	put_device(dev);
done:
	return res;
}
#endif


dev_t name_to_dev_t(char *name)
{
	char s[32];
	char *p;
	dev_t res = 0;
	int part;

#ifdef CONFIG_BLOCK
	if (strncmp(name, "PARTUUID=", 9) == 0) {
		name += 9;
		res = devt_from_partuuid(name);
		if (!res)
			goto fail;
		goto done;
	}
#endif

	if (strncmp(name, "/dev/", 5) != 0) {
		unsigned maj, min;

		if (sscanf(name, "%u:%u", &maj, &min) == 2) {
			res = MKDEV(maj, min);
			if (maj != MAJOR(res) || min != MINOR(res))
				goto fail;
		} else {
			res = new_decode_dev(simple_strtoul(name, &p, 16));
			if (*p)
				goto fail;
		}
		goto done;
	}

	name += 5;
	res = Root_NFS;
	if (strcmp(name, "nfs") == 0)
		goto done;
	res = Root_RAM0;
	if (strcmp(name, "ram") == 0)
		goto done;

	if (strlen(name) > 31)
		goto fail;
	strcpy(s, name);
	for (p = s; *p; p++)
		if (*p == '/')
			*p = '!';
	res = blk_lookup_devt(s, 0);
	if (res)
		goto done;

	while (p > s && isdigit(p[-1]))
		p--;
	if (p == s || !*p || *p == '0')
		goto fail;

	
	part = simple_strtoul(p, NULL, 10);
	*p = '\0';
	res = blk_lookup_devt(s, part);
	if (res)
		goto done;

	
	if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
		goto fail;
	p[-1] = '\0';
	res = blk_lookup_devt(s, part);
	if (res)
		goto done;

fail:
	return 0;
done:
	return res;
}

static int __init root_dev_setup(char *line)
{
	strlcpy(saved_root_name, line, sizeof(saved_root_name));
	return 1;
}

__setup("root=", root_dev_setup);

static int __init rootwait_setup(char *str)
{
	if (*str)
		return 0;
	root_wait = 1;
	return 1;
}

__setup("rootwait", rootwait_setup);

static char * __initdata root_mount_data;
static int __init root_data_setup(char *str)
{
	root_mount_data = str;
	return 1;
}

static char * __initdata root_fs_names;
static int __init fs_names_setup(char *str)
{
	root_fs_names = str;
	return 1;
}

static unsigned int __initdata root_delay;
static int __init root_delay_setup(char *str)
{
	root_delay = simple_strtoul(str, NULL, 0);
	return 1;
}

__setup("rootflags=", root_data_setup);
__setup("rootfstype=", fs_names_setup);
__setup("rootdelay=", root_delay_setup);

static void __init get_fs_names(char *page)
{
	char *s = page;

	if (root_fs_names) {
		strcpy(page, root_fs_names);
		while (*s++) {
			if (s[-1] == ',')
				s[-1] = '\0';
		}
	} else {
		int len = get_filesystem_list(page);
		char *p, *next;

		page[len] = '\0';
		for (p = page-1; p; p = next) {
			next = strchr(++p, '\n');
			if (*p++ != '\t')
				continue;
			while ((*s++ = *p++) != '\n')
				;
			s[-1] = '\0';
		}
	}
	*s = '\0';
}

static int __init do_mount_root(char *name, char *fs, int flags, void *data)
{
	struct super_block *s;
	int err = sys_mount(name, "/root", fs, flags, data);
	if (err)
		return err;

	sys_chdir((const char __user __force *)"/root");
	s = current->fs->pwd.dentry->d_sb;
	ROOT_DEV = s->s_dev;
	printk(KERN_INFO
	       "VFS: Mounted root (%s filesystem)%s on device %u:%u.\n",
	       s->s_type->name,
	       s->s_flags & MS_RDONLY ?  " readonly" : "",
	       MAJOR(ROOT_DEV), MINOR(ROOT_DEV));
	return 0;
}

void __init mount_block_root(char *name, int flags)
{
	char *fs_names = __getname_gfp(GFP_KERNEL
		| __GFP_NOTRACK_FALSE_POSITIVE);
	char *p;
#ifdef CONFIG_BLOCK
	char b[BDEVNAME_SIZE];
#else
	const char *b = name;
#endif

	get_fs_names(fs_names);
retry:
	for (p = fs_names; *p; p += strlen(p)+1) {
		int err = do_mount_root(name, p, flags, root_mount_data);
		switch (err) {
			case 0:
				goto out;
			case -EACCES:
				flags |= MS_RDONLY;
				goto retry;
			case -EINVAL:
				continue;
		}
#ifdef CONFIG_BLOCK
		__bdevname(ROOT_DEV, b);
#endif
		printk("VFS: Cannot open root device \"%s\" or %s: error %d\n",
				root_device_name, b, err);
		printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");

		printk_all_partitions();
#ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
		printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify "
		       "explicit textual name for \"root=\" boot option.\n");
#endif
		panic("VFS: Unable to mount root fs on %s", b);
	}

	printk("List of all partitions:\n");
	printk_all_partitions();
	printk("No filesystem could mount root, tried: ");
	for (p = fs_names; *p; p += strlen(p)+1)
		printk(" %s", p);
	printk("\n");
#ifdef CONFIG_BLOCK
	__bdevname(ROOT_DEV, b);
#endif
	panic("VFS: Unable to mount root fs on %s", b);
out:
	putname(fs_names);
}
 
#ifdef CONFIG_ROOT_NFS

#define NFSROOT_TIMEOUT_MIN	5
#define NFSROOT_TIMEOUT_MAX	30
#define NFSROOT_RETRY_MAX	5

static int __init mount_nfs_root(void)
{
	char *root_dev, *root_data;
	unsigned int timeout;
	int try, err;

	err = nfs_root_data(&root_dev, &root_data);
	if (err != 0)
		return 0;

	timeout = NFSROOT_TIMEOUT_MIN;
	for (try = 1; ; try++) {
		err = do_mount_root(root_dev, "nfs",
					root_mountflags, root_data);
		if (err == 0)
			return 1;
		if (try > NFSROOT_RETRY_MAX)
			break;

		
		ssleep(timeout);
		timeout <<= 1;
		if (timeout > NFSROOT_TIMEOUT_MAX)
			timeout = NFSROOT_TIMEOUT_MAX;
	}
	return 0;
}
#endif

#if defined(CONFIG_BLK_DEV_RAM) || defined(CONFIG_BLK_DEV_FD)
void __init change_floppy(char *fmt, ...)
{
	struct termios termios;
	char buf[80];
	char c;
	int fd;
	va_list args;
	va_start(args, fmt);
	vsprintf(buf, fmt, args);
	va_end(args);
	fd = sys_open("/dev/root", O_RDWR | O_NDELAY, 0);
	if (fd >= 0) {
		sys_ioctl(fd, FDEJECT, 0);
		sys_close(fd);
	}
	printk(KERN_NOTICE "VFS: Insert %s and press ENTER\n", buf);
	fd = sys_open("/dev/console", O_RDWR, 0);
	if (fd >= 0) {
		sys_ioctl(fd, TCGETS, (long)&termios);
		termios.c_lflag &= ~ICANON;
		sys_ioctl(fd, TCSETSF, (long)&termios);
		sys_read(fd, &c, 1);
		termios.c_lflag |= ICANON;
		sys_ioctl(fd, TCSETSF, (long)&termios);
		sys_close(fd);
	}
}
#endif

void __init mount_root(void)
{
#ifdef CONFIG_ROOT_NFS
	if (ROOT_DEV == Root_NFS) {
		if (mount_nfs_root())
			return;

		printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.\n");
		ROOT_DEV = Root_FD0;
	}
#endif
#ifdef CONFIG_BLK_DEV_FD
	if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
		
		if (rd_doload==2) {
			if (rd_load_disk(1)) {
				ROOT_DEV = Root_RAM1;
				root_device_name = NULL;
			}
		} else
			change_floppy("root floppy");
	}
#endif
#ifdef CONFIG_BLOCK
	create_dev("/dev/root", ROOT_DEV);
	mount_block_root("/dev/root", root_mountflags);
#endif
}

void __init prepare_namespace(void)
{
	int is_floppy;

	if (root_delay) {
		printk(KERN_INFO "Waiting %dsec before mounting root device...\n",
		       root_delay);
		ssleep(root_delay);
	}

	wait_for_device_probe();

	md_run_setup();

	if (saved_root_name[0]) {
		root_device_name = saved_root_name;
		if (!strncmp(root_device_name, "mtd", 3) ||
		    !strncmp(root_device_name, "ubi", 3)) {
			mount_block_root(root_device_name, root_mountflags);
			goto out;
		}
		ROOT_DEV = name_to_dev_t(root_device_name);
		if (strncmp(root_device_name, "/dev/", 5) == 0)
			root_device_name += 5;
	}

	if (initrd_load())
		goto out;

	
	if ((ROOT_DEV == 0) && root_wait) {
		printk(KERN_INFO "Waiting for root device %s...\n",
			saved_root_name);
		while (driver_probe_done() != 0 ||
			(ROOT_DEV = name_to_dev_t(saved_root_name)) == 0)
			msleep(100);
		async_synchronize_full();
	}

	is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;

	if (is_floppy && rd_doload && rd_load_disk(0))
		ROOT_DEV = Root_RAM0;

	mount_root();
out:
	devtmpfs_mount("dev");
	sys_mount(".", "/", NULL, MS_MOVE, NULL);
	sys_chroot((const char __user __force *)".");
}