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;
  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                 unsigned char spare0[14];
  23                 struct sun_info {
  24                         unsigned char spare1;
  25                         unsigned char id;
  26                         unsigned char spare2;
  27                         unsigned char flags;
  28                 } infos[8];
  29                 unsigned char spare[246];  /* Boot information etc. */
  30                 __be16 rspeed;     /* Disk rotational speed */
  31                 __be16 pcylcount;  /* Physical cylinder count */
  32                 __be16 sparecyl;   /* extra sects per cylinder */
  33                 unsigned char spare2[4];   /* More magic... */
  34                 __be16 ilfact;     /* Interleave factor */
  35                 __be16 ncyl;       /* Data cylinder count */
  36                 __be16 nacyl;      /* Alt. cylinder count */
  37                 __be16 ntrks;      /* Tracks per cylinder */
  38                 __be16 nsect;      /* Sectors per track */
  39                 unsigned char spare3[4];   /* Even more magic... */
  40                 struct sun_partition {
  41                         __be32 start_cylinder;
  42                         __be32 num_sectors;
  43                 } partitions[8];
  44                 __be16 magic;      /* Magic number */
  45                 __be16 csum;       /* Label xor'd checksum */
  46         } * label;
  47         struct sun_partition *p;
  48         unsigned long spc;
  49         char b[BDEVNAME_SIZE];
  50
  51         label = (struct sun_disklabel *)read_dev_sector(bdev, 0, &sect);
  52         if (!label)
  53                 return -1;
  54
  55         p = label->partitions;
  56         if (be16_to_cpu(label->magic) != SUN_LABEL_MAGIC) {
  57 /*              printk(KERN_INFO "Dev %s Sun disklabel: bad magic %04x\n",
  58                        bdevname(bdev, b), be16_to_cpu(label->magic)); */
  59                 put_dev_sector(sect);
  60                 return 0;
  61         }
  62         /* Look at the checksum */
  63         ush = ((__be16 *) (label+1)) - 1;
  64         for (csum = 0; ush >= ((__be16 *) label);)
  65                 csum ^= *ush--;
  66         if (csum) {
  67                 printk("Dev %s Sun disklabel: Csum bad, label corrupted\n",
  68                        bdevname(bdev, b));
  69                 put_dev_sector(sect);
  70                 return 0;
  71         }
  72
  73         /* All Sun disks have 8 partition entries */
  74         spc = be16_to_cpu(label->ntrks) * be16_to_cpu(label->nsect);
  75         for (i = 0; i < 8; i++, p++) {
  76                 unsigned long st_sector;
  77                 unsigned int num_sectors;
  78
  79                 st_sector = be32_to_cpu(p->start_cylinder) * spc;
  80                 num_sectors = be32_to_cpu(p->num_sectors);
  81                 if (num_sectors) {
  82                         put_partition(state, slot, st_sector, num_sectors);
  83                         if (label->infos[i].id == LINUX_RAID_PARTITION)
  84                                 state->parts[slot].flags = 1;
  85                 }
  86                 slot++;
  87         }
  88         printk("\n");
  89         put_dev_sector(sect);
  90         return 1;
  91 }