sun.c

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/*
 *  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)
{
    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 = read_part_sector(state, 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(state->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++;
    }
    strlcat(state->pp_buf, "\n", PAGE_SIZE);
    put_dev_sector(sect);
    return 1;
}