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
  13 int sun_partition(struct parsed_partitions *state, struct block_device *bdev)
  14 {
  15         int i, csum;
  16         int slot = 1;
  17         unsigned short *ush;
  18         Sector sect;
  19         struct sun_disklabel {
  20                 unsigned char info[128];   /* Informative text string */
  21                 unsigned char spare0[14];
  22                 struct sun_info {
  23                         unsigned char spare1;
  24                         unsigned char id;
  25                         unsigned char spare2;
  26                         unsigned char flags;
  27                 } infos[8];
  28                 unsigned char spare[246];  /* Boot information etc. */
  29                 unsigned short rspeed;     /* Disk rotational speed */
  30                 unsigned short pcylcount;  /* Physical cylinder count */
  31                 unsigned short sparecyl;   /* extra sects per cylinder */
  32                 unsigned char spare2[4];   /* More magic... */
  33                 unsigned short ilfact;     /* Interleave factor */
  34                 unsigned short ncyl;       /* Data cylinder count */
  35                 unsigned short nacyl;      /* Alt. cylinder count */
  36                 unsigned short ntrks;      /* Tracks per cylinder */
  37                 unsigned short nsect;      /* Sectors per track */
  38                 unsigned char spare3[4];   /* Even more magic... */
  39                 struct sun_partition {
  40                         __u32 start_cylinder;
  41                         __u32 num_sectors;
  42                 } partitions[8];
  43                 unsigned short magic;      /* Magic number */
  44                 unsigned short csum;       /* Label xor'd checksum */
  45         } * label;
  46         struct sun_partition *p;
  47         unsigned long spc;
  48         char b[BDEVNAME_SIZE];
  49
  50         label = (struct sun_disklabel *)read_dev_sector(bdev, 0, &sect);
  51         if (!label)
  52                 return -1;
  53
  54         p = label->partitions;
  55         if (be16_to_cpu(label->magic) != SUN_LABEL_MAGIC) {
  56 /*              printk(KERN_INFO "Dev %s Sun disklabel: bad magic %04x\n",
  57                        bdevname(bdev, b), be16_to_cpu(label->magic)); */
  58                 put_dev_sector(sect);
  59                 return 0;
  60         }
  61         /* Look at the checksum */
  62         ush = ((unsigned short *) (label+1)) - 1;
  63         for (csum = 0; ush >= ((unsigned short *) label);)
  64                 csum ^= *ush--;
  65         if (csum) {
  66                 printk("Dev %s Sun disklabel: Csum bad, label corrupted\n",
  67                        bdevname(bdev, b));
  68                 put_dev_sector(sect);
  69                 return 0;
  70         }
  71
  72         /* All Sun disks have 8 partition entries */
  73         spc = be16_to_cpu(label->ntrks) * be16_to_cpu(label->nsect);
  74         for (i = 0; i < 8; i++, p++) {
  75                 unsigned long st_sector;
  76                 int num_sectors;
  77
  78                 st_sector = be32_to_cpu(p->start_cylinder) * spc;
  79                 num_sectors = be32_to_cpu(p->num_sectors);
  80                 if (num_sectors) {
  81                         put_partition(state, slot, st_sector, num_sectors);
  82                         if (label->infos[i].id == LINUX_RAID_PARTITION)
  83                                 state->parts[slot].flags = 1;
  84                 }
  85                 slot++;
  86         }
  87         printk("\n");
  88         put_dev_sector(sect);
  89         return 1;
  90 }