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                 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 = (struct sun_disklabel *)read_dev_sector(bdev, 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(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         printk("\n");
 120         put_dev_sector(sect);
 121         return 1;
 122 }