/*
 *  Code extracted from drivers/block/genhd.c
 *  Copyright (C) 1991-1998  Linus Torvalds
 *  Re-organised Feb 1998 Russell King
 *
 *  We now have independent partition support from the
 *  block drivers, which allows all the partition code to
 *  be grouped in one location, and it to be mostly self
 *  contained.
 *
 *  Added needed MAJORS for new pairs, {hdi,hdj}, {hdk,hdl}
 */

#include <linux/config.h>
#include <linux/fs.h>
#include <linux/genhd.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/blk.h>
#include <linux/init.h>
#include <linux/raid/md.h>

#include "check.h"

#include "acorn.h"
#include "amiga.h"
#include "atari.h"
#include "ldm.h"
#include "mac.h"
#include "msdos.h"
#include "osf.h"
#include "sgi.h"
#include "sun.h"
#include "ibm.h"
#include "ultrix.h"
#include "efi.h"

extern int *blk_size[];

int warn_no_part = 1; /*This is ugly: should make genhd removable media aware*/

static int (*check_part[])(struct gendisk *hd, struct block_device *bdev, unsigned long first_sect, int first_minor) = {
#ifdef CONFIG_ACORN_PARTITION
        acorn_partition,
#endif
#ifdef CONFIG_SGI_PARTITION
        sgi_partition,
#endif
#ifdef CONFIG_EFI_PARTITION
        efi_partition,          /* this must come before msdos */
#endif
#ifdef CONFIG_LDM_PARTITION
        ldm_partition,          /* this must come before msdos */
#endif
#ifdef CONFIG_MSDOS_PARTITION
        msdos_partition,
#endif
#ifdef CONFIG_OSF_PARTITION
        osf_partition,
#endif
#ifdef CONFIG_SUN_PARTITION
        sun_partition,
#endif
#ifdef CONFIG_AMIGA_PARTITION
        amiga_partition,
#endif
#ifdef CONFIG_ATARI_PARTITION
        atari_partition,
#endif
#ifdef CONFIG_MAC_PARTITION
        mac_partition,
#endif
#ifdef CONFIG_ULTRIX_PARTITION
        ultrix_partition,
#endif
#ifdef CONFIG_IBM_PARTITION
        ibm_partition,
#endif
        NULL
};

/*
 *      This is ucking fugly but its probably the best thing for 2.4.x
 *      Take it as a clear reminder that: 1) we should put the device name
 *      generation in the object kdev_t points to in 2.5.
 *      and 2) ioctls better work on half-opened devices.
 */
 
#ifdef CONFIG_ARCH_S390
int (*genhd_dasd_name)(char*,int,int,struct gendisk*) = NULL;
int (*genhd_dasd_ioctl)(struct inode *inp, struct file *filp,
                            unsigned int no, unsigned long data);
EXPORT_SYMBOL(genhd_dasd_name);
EXPORT_SYMBOL(genhd_dasd_ioctl);
#endif

/*
 * disk_name() is used by partition check code and the md driver.
 * It formats the devicename of the indicated disk into
 * the supplied buffer (of size at least 32), and returns
 * a pointer to that same buffer (for convenience).
 */

char *disk_name (struct gendisk *hd, int minor, char *buf)
{
        const char *maj = hd->major_name;
        unsigned int unit = (minor >> hd->minor_shift);
        unsigned int part = (minor & ((1 << hd->minor_shift) -1 ));

        if ((unit < hd->nr_real) && hd->part[minor].de) {
                int pos;

                pos = devfs_generate_path (hd->part[minor].de, buf, 64);
                if (pos >= 0)
                        return buf + pos;
        }

#ifdef CONFIG_ARCH_S390
        if (genhd_dasd_name
            && genhd_dasd_name (buf, unit, part, hd) == 0)
                return buf;
#endif
        /*
         * IDE devices use multiple major numbers, but the drives
         * are named as:  {hda,hdb}, {hdc,hdd}, {hde,hdf}, {hdg,hdh}..
         * This requires special handling here.
         */
        switch (hd->major) {
                case IDE9_MAJOR:
                        unit += 2;
                case IDE8_MAJOR:
                        unit += 2;
                case IDE7_MAJOR:
                        unit += 2;
                case IDE6_MAJOR:
                        unit += 2;
                case IDE5_MAJOR:
                        unit += 2;
                case IDE4_MAJOR:
                        unit += 2;
                case IDE3_MAJOR:
                        unit += 2;
                case IDE2_MAJOR:
                        unit += 2;
                case IDE1_MAJOR:
                        unit += 2;
                case IDE0_MAJOR:
                        maj = "hd";
                        break;
                case MD_MAJOR:
                        sprintf(buf, "%s%d", maj, unit);
                        return buf;
        }
        if (hd->major >= SCSI_DISK1_MAJOR && hd->major <= SCSI_DISK7_MAJOR) {
                unit = unit + (hd->major - SCSI_DISK1_MAJOR + 1) * 16;
                if (unit+'a' > 'z') {
                        unit -= 26;
                        sprintf(buf, "sd%c%c", 'a' + unit / 26, 'a' + unit % 26);
                        if (part)
                                sprintf(buf + 4, "%d", part);
                        return buf;
                }
        }
        if (hd->major >= COMPAQ_SMART2_MAJOR && hd->major <= COMPAQ_SMART2_MAJOR+7) {
                int ctlr = hd->major - COMPAQ_SMART2_MAJOR;
                if (part == 0)
                        sprintf(buf, "%s/c%dd%d", maj, ctlr, unit);
                else
                        sprintf(buf, "%s/c%dd%dp%d", maj, ctlr, unit, part);
                return buf;
        }
        if (hd->major >= COMPAQ_CISS_MAJOR && hd->major <= COMPAQ_CISS_MAJOR+7) {
                int ctlr = hd->major - COMPAQ_CISS_MAJOR;
                if (part == 0)
                        sprintf(buf, "%s/c%dd%d", maj, ctlr, unit);
                else
                        sprintf(buf, "%s/c%dd%dp%d", maj, ctlr, unit, part);
                return buf;
        }
        if (hd->major >= DAC960_MAJOR && hd->major <= DAC960_MAJOR+7) {
                int ctlr = hd->major - DAC960_MAJOR;
                if (part == 0)
                        sprintf(buf, "%s/c%dd%d", maj, ctlr, unit);
                else
                        sprintf(buf, "%s/c%dd%dp%d", maj, ctlr, unit, part);
                return buf;
        }
        if (hd->major == ATARAID_MAJOR) {
                int disk = minor >> hd->minor_shift;
                int part = minor & (( 1 << hd->minor_shift) - 1);
                if (part == 0)
                        sprintf(buf, "%s/d%d", maj, disk);
                else
                        sprintf(buf, "%s/d%dp%d", maj, disk, part);
                return buf;
        }
        if (part)
                sprintf(buf, "%s%c%d", maj, unit+'a', part);
        else
                sprintf(buf, "%s%c", maj, unit+'a');
        return buf;
}

/*
 * Add a partitions details to the devices partition description.
 */
void add_gd_partition(struct gendisk *hd, int minor, int start, int size)
{
#ifndef CONFIG_DEVFS_FS
        char buf[40];
#endif

        hd->part[minor].start_sect = start;
        hd->part[minor].nr_sects   = size;
#ifdef CONFIG_DEVFS_FS
        printk(" p%d", (minor & ((1 << hd->minor_shift) - 1)));
#else
        if ((hd->major >= COMPAQ_SMART2_MAJOR+0 && hd->major <= COMPAQ_SMART2_MAJOR+7) ||
            (hd->major >= COMPAQ_CISS_MAJOR+0 && hd->major <= COMPAQ_CISS_MAJOR+7))
                printk(" p%d", (minor & ((1 << hd->minor_shift) - 1)));
        else
                printk(" %s", disk_name(hd, minor, buf));
#endif
}

static void check_partition(struct gendisk *hd, kdev_t dev, int first_part_minor)
{
        devfs_handle_t de = NULL;
        static int first_time = 1;
        unsigned long first_sector;
        struct block_device *bdev;
        char buf[64];
        int i;

        if (first_time)
                printk(KERN_INFO "Partition check:\n");
        first_time = 0;
        first_sector = hd->part[MINOR(dev)].start_sect;

        /*
         * This is a kludge to allow the partition check to be
         * skipped for specific drives (e.g. IDE CD-ROM drives)
         */
        if ((int)first_sector == -1) {
                hd->part[MINOR(dev)].start_sect = 0;
                return;
        }

        if (hd->de_arr)
                de = hd->de_arr[MINOR(dev) >> hd->minor_shift];
        i = devfs_generate_path (de, buf, sizeof buf);
        if (i >= 0)
                printk(KERN_INFO " /dev/%s:", buf + i);
        else
                printk(KERN_INFO " %s:", disk_name(hd, MINOR(dev), buf));
        bdev = bdget(kdev_t_to_nr(dev));
        bdev->bd_inode->i_size = (loff_t)hd->part[MINOR(dev)].nr_sects << 9;
        bdev->bd_inode->i_blkbits = blksize_bits(block_size(dev));
        for (i = 0; check_part[i]; i++) {
                int res;
                res = check_part[i](hd, bdev, first_sector, first_part_minor);
                if (res) {
                        if (res < 0 &&  warn_no_part)
                                printk(" unable to read partition table\n");
                        goto setup_devfs;
                }
        }

        printk(" unknown partition table\n");
setup_devfs:
        invalidate_bdev(bdev, 1);
        truncate_inode_pages(bdev->bd_inode->i_mapping, 0);
        bdput(bdev);
        i = first_part_minor - 1;
        devfs_register_partitions (hd, i, hd->sizes ? 0 : 1);
}

#ifdef CONFIG_DEVFS_FS
static void devfs_register_partition (struct gendisk *dev, int minor, int part)
{
        int devnum = minor >> dev->minor_shift;
        devfs_handle_t dir;
        unsigned int devfs_flags = DEVFS_FL_DEFAULT;
        char devname[16];

        if (dev->part[minor + part].de) return;
        dir = devfs_get_parent (dev->part[minor].de);
        if (!dir) return;
        if ( dev->flags && (dev->flags[devnum] & GENHD_FL_REMOVABLE) )
                devfs_flags |= DEVFS_FL_REMOVABLE;
        sprintf (devname, "part%d", part);
        dev->part[minor + part].de =
            devfs_register (dir, devname, devfs_flags,
                            dev->major, minor + part,
                            S_IFBLK | S_IRUSR | S_IWUSR,
                            dev->fops, NULL);
}

static struct unique_numspace disc_numspace = UNIQUE_NUMBERSPACE_INITIALISER;

static void devfs_register_disc (struct gendisk *dev, int minor)
{
        int pos = 0;
        int devnum = minor >> dev->minor_shift;
        devfs_handle_t dir, slave;
        unsigned int devfs_flags = DEVFS_FL_DEFAULT;
        char dirname[64], symlink[16];
        static devfs_handle_t devfs_handle;

        if (dev->part[minor].de) return;
        if ( dev->flags && (dev->flags[devnum] & GENHD_FL_REMOVABLE) )
                devfs_flags |= DEVFS_FL_REMOVABLE;
        if (dev->de_arr) {
                dir = dev->de_arr[devnum];
                if (!dir)  /*  Aware driver wants to block disc management  */
                        return;
                pos = devfs_generate_path (dir, dirname + 3, sizeof dirname-3);
                if (pos < 0) return;
                strncpy (dirname + pos, "../", 3);
        }
        else {
                /*  Unaware driver: construct "real" directory  */
                sprintf (dirname, "../%s/disc%d", dev->major_name, devnum);
                dir = devfs_mk_dir (NULL, dirname + 3, NULL);
        }
        if (!devfs_handle)
                devfs_handle = devfs_mk_dir (NULL, "discs", NULL);
        dev->part[minor].number = devfs_alloc_unique_number (&disc_numspace);
        sprintf (symlink, "disc%d", dev->part[minor].number);
        devfs_mk_symlink (devfs_handle, symlink, DEVFS_FL_DEFAULT,
                          dirname + pos, &slave, NULL);
        dev->part[minor].de =
            devfs_register (dir, "disc", devfs_flags, dev->major, minor,
                            S_IFBLK | S_IRUSR | S_IWUSR, dev->fops, NULL);
        devfs_auto_unregister (dev->part[minor].de, slave);
        if (!dev->de_arr)
                devfs_auto_unregister (slave, dir);
}
#endif  /*  CONFIG_DEVFS_FS  */

void devfs_register_partitions (struct gendisk *dev, int minor, int unregister)
{
#ifdef CONFIG_DEVFS_FS
        int part;

        if (!unregister)
                devfs_register_disc (dev, minor);
        for (part = 1; part < dev->max_p; part++) {
                if ( unregister || (dev->part[minor].nr_sects < 1) ||
                     (dev->part[part + minor].nr_sects < 1) ) {
                        devfs_unregister (dev->part[part + minor].de);
                        dev->part[part + minor].de = NULL;
                        continue;
                }
                devfs_register_partition (dev, minor, part);
        }
        if (unregister) {
                devfs_unregister (dev->part[minor].de);
                dev->part[minor].de = NULL;
                devfs_dealloc_unique_number (&disc_numspace,
                                             dev->part[minor].number);
        }
#endif  /*  CONFIG_DEVFS_FS  */
}

/*
 * This function will re-read the partition tables for a given device,
 * and set things back up again.  There are some important caveats,
 * however.  You must ensure that no one is using the device, and no one
 * can start using the device while this function is being executed.
 *
 * Much of the cleanup from the old partition tables should have already been
 * done
 */

void register_disk(struct gendisk *gdev, kdev_t dev, unsigned minors,
        struct block_device_operations *ops, long size)
{
        if (!gdev)
                return;
        grok_partitions(gdev, MINOR(dev)>>gdev->minor_shift, minors, size);
}

void grok_partitions(struct gendisk *dev, int drive, unsigned minors, long size)
{
        int i;
        int first_minor = drive << dev->minor_shift;
        int end_minor   = first_minor + dev->max_p;

        if(!dev->sizes)
                blk_size[dev->major] = NULL;

        dev->part[first_minor].nr_sects = size;
        /* No such device or no minors to use for partitions */
        if ( !size && dev->flags && (dev->flags[drive] & GENHD_FL_REMOVABLE) )
                devfs_register_partitions (dev, first_minor, 0);
        if (!size || minors == 1)
                return;

        if (dev->sizes) {
                dev->sizes[first_minor] = size >> (BLOCK_SIZE_BITS - 9);
                for (i = first_minor + 1; i < end_minor; i++)
                        dev->sizes[i] = 0;
        }
        blk_size[dev->major] = dev->sizes;
        check_partition(dev, MKDEV(dev->major, first_minor), 1 + first_minor);

        /*
         * We need to set the sizes array before we will be able to access
         * any of the partitions on this device.
         */
        if (dev->sizes != NULL) {       /* optional safeguard in ll_rw_blk.c */
                for (i = first_minor; i < end_minor; i++)
                        dev->sizes[i] = dev->part[i].nr_sects >> (BLOCK_SIZE_BITS - 9);
        }
}

unsigned char *read_dev_sector(struct block_device *bdev, unsigned long n, Sector *p)
{
        struct address_space *mapping = bdev->bd_inode->i_mapping;
        int sect = PAGE_CACHE_SIZE / 512;
        struct page *page;

        page = read_cache_page(mapping, n/sect,
                        (filler_t *)mapping->a_ops->readpage, NULL);
        if (!IS_ERR(page)) {
                wait_on_page(page);
                if (!Page_Uptodate(page))
                        goto fail;
                if (PageError(page))
                        goto fail;
                p->v = page;
                return (unsigned char *)page_address(page) + 512 * (n % sect);
fail:
                page_cache_release(page);
        }
        p->v = NULL;
        return NULL;
}