root/fs/partitions/sun.c

DEFINITIONS

1. sun_partition

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

#include "check.h"
#include "sun.h"

int sun_partition(struct parsed_partitions *state, struct block_device *bdev)
{
        int i;
        __be16 csum;
        int slot = 1;
        __be16 *ush;
        Sector sect;
        struct sun_disklabel {
                unsigned char info[128];   /* Informative text string */
                struct sun_vtoc {
                    __be32 version;     /* Layout version */
                    char   volume[8];   /* Volume name */
                    __be16 nparts;      /* Number of partitions */
                    struct sun_info {           /* Partition hdrs, sec 2 */
                        __be16 id;
                        __be16 flags;
                    } infos[8];
                    __be16 padding;     /* Alignment padding */
                    __be32 bootinfo[3];  /* Info needed by mboot */
                    __be32 sanity;       /* To verify vtoc sanity */
                    __be32 reserved[10]; /* Free space */
                    __be32 timestamp[8]; /* Partition timestamp */
                } vtoc;
                __be32 write_reinstruct; /* sectors to skip, writes */
                __be32 read_reinstruct;  /* sectors to skip, reads */
                unsigned char spare[148]; /* Padding */
                __be16 rspeed;     /* Disk rotational speed */
                __be16 pcylcount;  /* Physical cylinder count */
                __be16 sparecyl;   /* extra sects per cylinder */
                __be16 obs1;       /* gap1 */
                __be16 obs2;       /* gap2 */
                __be16 ilfact;     /* Interleave factor */
                __be16 ncyl;       /* Data cylinder count */
                __be16 nacyl;      /* Alt. cylinder count */
                __be16 ntrks;      /* Tracks per cylinder */
                __be16 nsect;      /* Sectors per track */
                __be16 obs3;       /* bhead - Label head offset */
                __be16 obs4;       /* ppart - Physical Partition */
                struct sun_partition {
                        __be32 start_cylinder;
                        __be32 num_sectors;
                } partitions[8];
                __be16 magic;      /* Magic number */
                __be16 csum;       /* Label xor'd checksum */
        } * label;
        struct sun_partition *p;
        unsigned long spc;
        char b[BDEVNAME_SIZE];
        int use_vtoc;
        int nparts;

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

        p = label->partitions;
        if (be16_to_cpu(label->magic) != SUN_LABEL_MAGIC) {
/*              printk(KERN_INFO "Dev %s Sun disklabel: bad magic %04x\n",
                       bdevname(bdev, b), be16_to_cpu(label->magic)); */
                put_dev_sector(sect);
                return 0;
        }
        /* Look at the checksum */
        ush = ((__be16 *) (label+1)) - 1;
        for (csum = 0; ush >= ((__be16 *) label);)
                csum ^= *ush--;
        if (csum) {
                printk("Dev %s Sun disklabel: Csum bad, label corrupted\n",
                       bdevname(bdev, b));
                put_dev_sector(sect);
                return 0;
        }

        /* Check to see if we can use the VTOC table */
        use_vtoc = ((be32_to_cpu(label->vtoc.sanity) == SUN_VTOC_SANITY) &&
                    (be32_to_cpu(label->vtoc.version) == 1) &&
                    (be16_to_cpu(label->vtoc.nparts) <= 8));

        /* Use 8 partition entries if not specified in validated VTOC */
        nparts = (use_vtoc) ? be16_to_cpu(label->vtoc.nparts) : 8;

        /*
         * So that old Linux-Sun partitions continue to work,
         * alow the VTOC to be used under the additional condition ...
         */
        use_vtoc = use_vtoc || !(label->vtoc.sanity ||
                                 label->vtoc.version || label->vtoc.nparts);
        spc = be16_to_cpu(label->ntrks) * be16_to_cpu(label->nsect);
        for (i = 0; i < nparts; i++, p++) {
                unsigned long st_sector;
                unsigned int num_sectors;

                st_sector = be32_to_cpu(p->start_cylinder) * spc;
                num_sectors = be32_to_cpu(p->num_sectors);
                if (num_sectors) {
                        put_partition(state, slot, st_sector, num_sectors);
                        state->parts[slot].flags = 0;
                        if (use_vtoc) {
                                if (be16_to_cpu(label->vtoc.infos[i].id) == LINUX_RAID_PARTITION)
                                        state->parts[slot].flags |= ADDPART_FLAG_RAID;
                                else if (be16_to_cpu(label->vtoc.infos[i].id) == SUN_WHOLE_DISK)
                                        state->parts[slot].flags |= ADDPART_FLAG_WHOLEDISK;
                        }
                }
                slot++;
        }
        printk("\n");
        put_dev_sector(sect);
        return 1;
}