root/fs/partitions/atari.c

DEFINITIONS

1. OK_id
2. atari_partition

/*
 *  fs/partitions/atari.c
 *
 *  Code extracted from drivers/block/genhd.c
 *
 *  Copyright (C) 1991-1998  Linus Torvalds
 *  Re-organised Feb 1998 Russell King
 */

#include <linux/ctype.h>
#include "check.h"
#include "atari.h"

/* ++guenther: this should be settable by the user ("make config")?.
 */
#define ICD_PARTS

/* check if a partition entry looks valid -- Atari format is assumed if at
   least one of the primary entries is ok this way */
#define VALID_PARTITION(pi,hdsiz)                                            \
    (((pi)->flg & 1) &&                                                      \
     isalnum((pi)->id[0]) && isalnum((pi)->id[1]) && isalnum((pi)->id[2]) && \
     be32_to_cpu((pi)->st) <= (hdsiz) &&                                     \
     be32_to_cpu((pi)->st) + be32_to_cpu((pi)->siz) <= (hdsiz))

static inline int OK_id(char *s)
{
        return  memcmp (s, "GEM", 3) == 0 || memcmp (s, "BGM", 3) == 0 ||
                memcmp (s, "LNX", 3) == 0 || memcmp (s, "SWP", 3) == 0 ||
                memcmp (s, "RAW", 3) == 0 ;
}

int atari_partition(struct parsed_partitions *state, struct block_device *bdev)
{
        Sector sect;
        struct rootsector *rs;
        struct partition_info *pi;
        u32 extensect;
        u32 hd_size;
        int slot;
#ifdef ICD_PARTS
        int part_fmt = 0; /* 0:unknown, 1:AHDI, 2:ICD/Supra */
#endif

        rs = (struct rootsector *) read_dev_sector(bdev, 0, &sect);
        if (!rs)
                return -1;

        /* Verify this is an Atari rootsector: */
        hd_size = bdev->bd_inode->i_size >> 9;
        if (!VALID_PARTITION(&rs->part[0], hd_size) &&
            !VALID_PARTITION(&rs->part[1], hd_size) &&
            !VALID_PARTITION(&rs->part[2], hd_size) &&
            !VALID_PARTITION(&rs->part[3], hd_size)) {
                /*
                 * if there's no valid primary partition, assume that no Atari
                 * format partition table (there's no reliable magic or the like
                 * :-()
                 */
                put_dev_sector(sect);
                return 0;
        }

        pi = &rs->part[0];
        printk (" AHDI");
        for (slot = 1; pi < &rs->part[4] && slot < state->limit; slot++, pi++) {
                struct rootsector *xrs;
                Sector sect2;
                ulong partsect;

                if ( !(pi->flg & 1) )
                        continue;
                /* active partition */
                if (memcmp (pi->id, "XGM", 3) != 0) {
                        /* we don't care about other id's */
                        put_partition (state, slot, be32_to_cpu(pi->st),
                                        be32_to_cpu(pi->siz));
                        continue;
                }
                /* extension partition */
#ifdef ICD_PARTS
                part_fmt = 1;
#endif
                printk(" XGM<");
                partsect = extensect = be32_to_cpu(pi->st);
                while (1) {
                        xrs = (struct rootsector *)read_dev_sector(bdev, partsect, &sect2);
                        if (!xrs) {
                                printk (" block %ld read failed\n", partsect);
                                put_dev_sector(sect);
                                return -1;
                        }

                        /* ++roman: sanity check: bit 0 of flg field must be set */
                        if (!(xrs->part[0].flg & 1)) {
                                printk( "\nFirst sub-partition in extended partition is not valid!\n" );
                                put_dev_sector(sect2);
                                break;
                        }

                        put_partition(state, slot,
                                   partsect + be32_to_cpu(xrs->part[0].st),
                                   be32_to_cpu(xrs->part[0].siz));

                        if (!(xrs->part[1].flg & 1)) {
                                /* end of linked partition list */
                                put_dev_sector(sect2);
                                break;
                        }
                        if (memcmp( xrs->part[1].id, "XGM", 3 ) != 0) {
                                printk("\nID of extended partition is not XGM!\n");
                                put_dev_sector(sect2);
                                break;
                        }

                        partsect = be32_to_cpu(xrs->part[1].st) + extensect;
                        put_dev_sector(sect2);
                        if (++slot == state->limit) {
                                printk( "\nMaximum number of partitions reached!\n" );
                                break;
                        }
                }
                printk(" >");
        }
#ifdef ICD_PARTS
        if ( part_fmt!=1 ) { /* no extended partitions -> test ICD-format */
                pi = &rs->icdpart[0];
                /* sanity check: no ICD format if first partition invalid */
                if (OK_id(pi->id)) {
                        printk(" ICD<");
                        for (; pi < &rs->icdpart[8] && slot < state->limit; slot++, pi++) {
                                /* accept only GEM,BGM,RAW,LNX,SWP partitions */
                                if (!((pi->flg & 1) && OK_id(pi->id)))
                                        continue;
                                part_fmt = 2;
                                put_partition (state, slot,
                                                be32_to_cpu(pi->st),
                                                be32_to_cpu(pi->siz));
                        }
                        printk(" >");
                }
        }
#endif
        put_dev_sector(sect);

        printk ("\n");

        return 1;
}