fs/partitions/sgi.c

   1 /*
   2  *  fs/partitions/sgi.c
   3  *
   4  *  Code extracted from drivers/block/genhd.c
   5  */
   6
   7 #include "check.h"
   8 #include "sgi.h"
   9
  10 struct sgi_disklabel {
  11         __be32 magic_mushroom;          /* Big fat spliff... */
  12         __be16 root_part_num;           /* Root partition number */
  13         __be16 swap_part_num;           /* Swap partition number */
  14         s8 boot_file[16];               /* Name of boot file for ARCS */
  15         u8 _unused0[48];                /* Device parameter useless crapola.. */
  16         struct sgi_volume {
  17                 s8 name[8];             /* Name of volume */
  18                 __be32 block_num;               /* Logical block number */
  19                 __be32 num_bytes;               /* How big, in bytes */
  20         } volume[15];
  21         struct sgi_partition {
  22                 __be32 num_blocks;              /* Size in logical blocks */
  23                 __be32 first_block;     /* First logical block */
  24                 __be32 type;            /* Type of this partition */
  25         } partitions[16];
  26         __be32 csum;                    /* Disk label checksum */
  27         __be32 _unused1;                        /* Padding */
  28 };
  29
  30 int sgi_partition(struct parsed_partitions *state, struct block_device *bdev)
  31 {
  32         int i, csum;
  33         __be32 magic;
  34         int slot = 1;
  35         unsigned int start, blocks;
  36         __be32 *ui, cs;
  37         Sector sect;
  38         struct sgi_disklabel *label;
  39         struct sgi_partition *p;
  40         char b[BDEVNAME_SIZE];
  41
  42         label = (struct sgi_disklabel *) read_dev_sector(bdev, 0, &sect);
  43         if (!label)
  44                 return -1;
  45         p = &label->partitions[0];
  46         magic = label->magic_mushroom;
  47         if(be32_to_cpu(magic) != SGI_LABEL_MAGIC) {
  48                 /*printk("Dev %s SGI disklabel: bad magic %08x\n",
  49                        bdevname(bdev, b), be32_to_cpu(magic));*/
  50                 put_dev_sector(sect);
  51                 return 0;
  52         }
  53         ui = ((__be32 *) (label + 1)) - 1;
  54         for(csum = 0; ui >= ((__be32 *) label);) {
  55                 cs = *ui--;
  56                 csum += be32_to_cpu(cs);
  57         }
  58         if(csum) {
  59                 printk(KERN_WARNING "Dev %s SGI disklabel: csum bad, label corrupted\n",
  60                        bdevname(bdev, b));
  61                 put_dev_sector(sect);
  62                 return 0;
  63         }
  64         /* All SGI disk labels have 16 partitions, disks under Linux only
  65          * have 15 minor's.  Luckily there are always a few zero length
  66          * partitions which we don't care about so we never overflow the
  67          * current_minor.
  68          */
  69         for(i = 0; i < 16; i++, p++) {
  70                 blocks = be32_to_cpu(p->num_blocks);
  71                 start  = be32_to_cpu(p->first_block);
  72                 if (blocks) {
  73                         put_partition(state, slot, start, blocks);
  74                         if (be32_to_cpu(p->type) == LINUX_RAID_PARTITION)
  75                                 state->parts[slot].flags = ADDPART_FLAG_RAID;
  76                 }
  77                 slot++;
  78         }
  79         printk("\n");
  80         put_dev_sector(sect);
  81         return 1;
  82 }