#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/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_VERBOSE;
char * __initdata root_device_name;
static char __initdata saved_root_name[64];

/* this is initialized in init/main.c */
dev_t ROOT_DEV;

EXPORT_SYMBOL(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 __init 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] != '\n')
                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] != '\n')
                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.
 *      Driverfs 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 driverfs node has them replaced with
 *      bangs.  try_name() does the actual checks, assuming that driverfs
 *      is mounted on rootfs /sys.
 */

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

#ifdef CONFIG_SYSFS
        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:
        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;
}

__setup("rootflags=", root_data_setup);
__setup("rootfstype=", fs_names_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)
{
        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.\n",
               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;
        char b[BDEVNAME_SIZE];

        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.
                 */
                __bdevname(ROOT_DEV, b);
                printk("VFS: Cannot open root device \"%s\" or %s\n",
                                root_device_name, b);
                printk("Please append a correct \"root=\" boot option\n");

                panic("VFS: Unable to mount root fs on %s", b);
        }
        panic("VFS: Unable to mount root fs on %s", __bdevname(ROOT_DEV, 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, NULL);
        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\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 (MAJOR(ROOT_DEV) == UNNAMED_MAJOR) {
                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) {
                /* 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
        create_dev("/dev/root", ROOT_DEV, root_device_name);
        mount_block_root("/dev/root", root_mountflags);
}

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

        mount_devfs();

        md_run_setup();

        if (saved_root_name[0]) {
                root_device_name = saved_root_name;
                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:
        umount_devfs("/dev");
        sys_mount(".", "/", NULL, MS_MOVE, NULL);
        sys_chroot(".");
        security_sb_post_mountroot();
        mount_devfs_fs ();
}