#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/mount.h>

  #include <linux/device.h>

  
  #include <linux/nfs_fs.h>
  #include <linux/nfs_fs_sb.h>
  #include <linux/nfs_mount.h>
  
  #include "do_mounts.h"
  
  extern int get_filesystem_list(char * buf);
  
  int __initdata rd_doload;	/* 1 = load RAM disk, 0 = don't load */

  int root_mountflags = MS_RDONLY | MS_SILENT;

  char * __initdata root_device_name;
  static char __initdata saved_root_name[64];

  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);
  
  static dev_t try_name(char *name, int part)
  {
  	char path[64];
  	char buf[32];
  	int range;
  	dev_t res;
  	char *s;
  	int len;
  	int fd;
  	unsigned int maj, min;
  
  	/* read device number from .../dev */
  
  	sprintf(path, "/sys/block/%s/dev", name);
  	fd = sys_open(path, 0, 0);
  	if (fd < 0)
  		goto fail;
  	len = sys_read(fd, buf, 32);
  	sys_close(fd);
  	if (len <= 0 || len == 32 || buf[len - 1] != '
  ')
  		goto fail;
  	buf[len - 1] = '\0';
  	if (sscanf(buf, "%u:%u", &maj, &min) == 2) {
  		/*
  		 * Try the %u:%u format -- see print_dev_t()
  		 */
  		res = MKDEV(maj, min);
  		if (maj != MAJOR(res) || min != MINOR(res))
  			goto fail;
  	} else {
  		/*
  		 * Nope.  Try old-style "0321"
  		 */
  		res = new_decode_dev(simple_strtoul(buf, &s, 16));
  		if (*s)
  			goto fail;
  	}
  
  	/* if it's there and we are not looking for a partition - that's it */
  	if (!part)
  		return res;
  
  	/* otherwise read range from .../range */
  	sprintf(path, "/sys/block/%s/range", name);
  	fd = sys_open(path, 0, 0);
  	if (fd < 0)
  		goto fail;
  	len = sys_read(fd, buf, 32);
  	sys_close(fd);
  	if (len <= 0 || len == 32 || buf[len - 1] != '
  ')
  		goto fail;
  	buf[len - 1] = '\0';
  	range = simple_strtoul(buf, &s, 10);
  	if (*s)
  		goto fail;
  
  	/* if partition is within range - we got it */
  	if (part < range)
  		return res + part;
  fail:
  	return 0;
  }
  
  /*
   *	Convert a name into device number.  We accept the following variants:
   *
   *	1) device number in hexadecimal	represents itself
   *	2) /dev/nfs represents Root_NFS (0xff)
   *	3) /dev/<disk_name> represents the device number of disk
   *	4) /dev/<disk_name><decimal> represents the device number
   *         of partition - device number of disk plus the partition number
   *	5) /dev/<disk_name>p<decimal> - same as the above, that form is
   *	   used when disk name of partitioned disk ends on a digit.
   *
   *	If name doesn't have fall into the categories above, we return 0.

   *	Sysfs is used to check if something is a disk name - it has

   *	all known disks under bus/block/devices.  If the disk name

   *	contains slashes, name of sysfs node has them replaced with
   *	bangs.  try_name() does the actual checks, assuming that sysfs

   *	is mounted on rootfs /sys.
   */
  
  dev_t name_to_dev_t(char *name)
  {
  	char s[32];
  	char *p;
  	dev_t res = 0;
  	int part;
  
  #ifdef CONFIG_SYSFS
  	int mkdir_err = sys_mkdir("/sys", 0700);
  	if (sys_mount("sysfs", "/sys", "sysfs", 0, NULL) < 0)
  		goto out;
  #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 = try_name(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 = try_name(s, part);
  	if (res)
  		goto done;
  
  	if (p < s + 2 || !isdigit(p[-2]) || p[-1] != 'p')
  		goto fail;
  	p[-1] = '\0';
  	res = try_name(s, part);
  done:
  #ifdef CONFIG_SYSFS
  	sys_umount("/sys", 0);
  out:
  	if (!mkdir_err)
  		sys_rmdir("/sys");
  #endif
  	return res;
  fail:
  	res = 0;
  	goto done;
  }
  
  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 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, '
  ');
  			if (*p++ != '\t')
  				continue;
  			while ((*s++ = *p++) != '
  ')
  				;
  			s[-1] = '\0';
  		}
  	}
  	*s = '\0';
  }
  
  static int __init do_mount_root(char *name, char *fs, int flags, void *data)
  {
  	int err = sys_mount(name, "/root", fs, flags, data);
  	if (err)
  		return err;
  
  	sys_chdir("/root");
  	ROOT_DEV = current->fs->pwdmnt->mnt_sb->s_dev;
  	printk("VFS: Mounted root (%s filesystem)%s.
  ",
  	       current->fs->pwdmnt->mnt_sb->s_type->name,
  	       current->fs->pwdmnt->mnt_sb->s_flags & MS_RDONLY ? 
  	       " readonly" : "");
  	return 0;
  }
  
  void __init mount_block_root(char *name, int flags)
  {
  	char *fs_names = __getname();
  	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;
  		}
  	        /*
  		 * Allow the user to distinguish between failed sys_open
  		 * and bad superblock on root device.
  		 */

  #ifdef CONFIG_BLOCK

  		__bdevname(ROOT_DEV, b);

  #endif

  		printk("VFS: Cannot open root device \"%s\" or %s
  ",
  				root_device_name, b);
  		printk("Please append a correct \"root=\" boot option
  ");
  
  		panic("VFS: Unable to mount root fs on %s", b);
  	}

  
  	printk("No filesystem could mount root, tried: ");
  	for (p = fs_names; *p; p += strlen(p)+1)
  		printk(" %s", p);
  	printk("
  ");

  #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
  static int __init mount_nfs_root(void)
  {
  	void *data = nfs_root_data();

  	create_dev("/dev/root", ROOT_DEV);

  	if (data &&
  	    do_mount_root("/dev/root", "nfs", root_mountflags, data) == 0)
  		return 1;
  	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
  ", 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 (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
  		if (mount_nfs_root())
  			return;
  
  		printk(KERN_ERR "VFS: Unable to mount root fs via NFS, trying floppy.
  ");
  		ROOT_DEV = Root_FD0;
  	}
  #endif
  #ifdef CONFIG_BLK_DEV_FD
  	if (MAJOR(ROOT_DEV) == FLOPPY_MAJOR) {
  		/* rd_doload is 2 for a dual initrd/ramload setup */
  		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

  }
  
  /*
   * Prepare the namespace - decide what/where to mount, load ramdisks, etc.
   */
  void __init prepare_namespace(void)
  {
  	int is_floppy;

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

  	/* wait for the known devices to complete their probing */
  	while (driver_probe_done() != 0)
  		msleep(100);

  	md_run_setup();
  
  	if (saved_root_name[0]) {
  		root_device_name = saved_root_name;

  		if (!strncmp(root_device_name, "mtd", 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;
  	}
  
  	is_floppy = MAJOR(ROOT_DEV) == FLOPPY_MAJOR;
  
  	if (initrd_load())
  		goto out;
  
  	if (is_floppy && rd_doload && rd_load_disk(0))
  		ROOT_DEV = Root_RAM0;
  
  	mount_root();
  out:

  	sys_mount(".", "/", NULL, MS_MOVE, NULL);
  	sys_chroot(".");
  	security_sb_post_mountroot();

  }