LXR linux/fs/partitions/sun.c

   1/*
   2 *  fs/partitions/sun.c
   3 *
   4 *  Code extracted from drivers/block/genhd.c
   5 *
   6 *  Copyright (C) 1991-1998  Linus Torvalds
   7 *  Re-organised Feb 1998 Russell King
   8 */
   9
  10#include "check.h"
  11#include "sun.h"
  12
  13int sun_partition(struct parsed_partitions *state)
  14{
  15        int i;
  16        __be16 csum;
  17        int slot = 1;
  18        __be16 *ush;
  19        Sector sect;
  20        struct sun_disklabel {
  21                unsigned char info[128];   /* Informative text string */
  22                struct sun_vtoc {
  23                    __be32 version;     /* Layout version */
  24                    char   volume[8];   /* Volume name */
  25                    __be16 nparts;      /* Number of partitions */
  26                    struct sun_info {           /* Partition hdrs, sec 2 */
  27                        __be16 id;
  28                        __be16 flags;
  29                    } infos[8];
  30                    __be16 padding;     /* Alignment padding */
  31                    __be32 bootinfo[3];  /* Info needed by mboot */
  32                    __be32 sanity;       /* To verify vtoc sanity */
  33                    __be32 reserved[10]; /* Free space */
  34                    __be32 timestamp[8]; /* Partition timestamp */
  35                } vtoc;
  36                __be32 write_reinstruct; /* sectors to skip, writes */
  37                __be32 read_reinstruct;  /* sectors to skip, reads */
  38                unsigned char spare[148]; /* Padding */
  39                __be16 rspeed;     /* Disk rotational speed */
  40                __be16 pcylcount;  /* Physical cylinder count */
  41                __be16 sparecyl;   /* extra sects per cylinder */
  42                __be16 obs1;       /* gap1 */
  43                __be16 obs2;       /* gap2 */
  44                __be16 ilfact;     /* Interleave factor */
  45                __be16 ncyl;       /* Data cylinder count */
  46                __be16 nacyl;      /* Alt. cylinder count */
  47                __be16 ntrks;      /* Tracks per cylinder */
  48                __be16 nsect;      /* Sectors per track */
  49                __be16 obs3;       /* bhead - Label head offset */
  50                __be16 obs4;       /* ppart - Physical Partition */
  51                struct sun_partition {
  52                        __be32 start_cylinder;
  53                        __be32 num_sectors;
  54                } partitions[8];
  55                __be16 magic;      /* Magic number */
  56                __be16 csum;       /* Label xor'd checksum */
  57        } * label;
  58        struct sun_partition *p;
  59        unsigned long spc;
  60        char b[BDEVNAME_SIZE];
  61        int use_vtoc;
  62        int nparts;
  63
  64        label = read_part_sector(state, 0, &sect);
  65        if (!label)
  66                return -1;
  67
  68        p = label->partitions;
  69        if (be16_to_cpu(label->magic) != SUN_LABEL_MAGIC) {
  70/*              printk(KERN_INFO "Dev %s Sun disklabel: bad magic %04x\n",
  71                       bdevname(bdev, b), be16_to_cpu(label->magic)); */
  72                put_dev_sector(sect);
  73                return 0;
  74        }
  75        /* Look at the checksum */
  76        ush = ((__be16 *) (label+1)) - 1;
  77        for (csum = 0; ush >= ((__be16 *) label);)
  78                csum ^= *ush--;
  79        if (csum) {
  80                printk("Dev %s Sun disklabel: Csum bad, label corrupted\n",
  81                       bdevname(state->bdev, b));
  82                put_dev_sector(sect);
  83                return 0;
  84        }
  85
  86        /* Check to see if we can use the VTOC table */
  87        use_vtoc = ((be32_to_cpu(label->vtoc.sanity) == SUN_VTOC_SANITY) &&
  88                    (be32_to_cpu(label->vtoc.version) == 1) &&
  89                    (be16_to_cpu(label->vtoc.nparts) <= 8));
  90
  91        /* Use 8 partition entries if not specified in validated VTOC */
  92        nparts = (use_vtoc) ? be16_to_cpu(label->vtoc.nparts) : 8;
  93
  94        /*
  95         * So that old Linux-Sun partitions continue to work,
  96         * alow the VTOC to be used under the additional condition ...
  97         */
  98        use_vtoc = use_vtoc || !(label->vtoc.sanity ||
  99                                 label->vtoc.version || label->vtoc.nparts);
 100        spc = be16_to_cpu(label->ntrks) * be16_to_cpu(label->nsect);
 101        for (i = 0; i < nparts; i++, p++) {
 102                unsigned long st_sector;
 103                unsigned int num_sectors;
 104
 105                st_sector = be32_to_cpu(p->start_cylinder) * spc;
 106                num_sectors = be32_to_cpu(p->num_sectors);
 107                if (num_sectors) {
 108                        put_partition(state, slot, st_sector, num_sectors);
 109                        state->parts[slot].flags = 0;
 110                        if (use_vtoc) {
 111                                if (be16_to_cpu(label->vtoc.infos[i].id) == LINUX_RAID_PARTITION)
 112                                        state->parts[slot].flags |= ADDPART_FLAG_RAID;
 113                                else if (be16_to_cpu(label->vtoc.infos[i].id) == SUN_WHOLE_DISK)
 114                                        state->parts[slot].flags |= ADDPART_FLAG_WHOLEDISK;
 115                        }
 116                }
 117                slot++;
 118        }
 119        strlcat(state->pp_buf, "\n", PAGE_SIZE);
 120        put_dev_sector(sect);
 121        return 1;
 122}
 123