block/partitions/sun.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  fs/partitions/sun.c
   4  *
   5  *  Code extracted from drivers/block/genhd.c
   6  *
   7  *  Copyright (C) 1991-1998  Linus Torvalds
   8  *  Re-organised Feb 1998 Russell King
   9  */
  10
  11 #include "check.h"
  12
  13 #define SUN_LABEL_MAGIC          0xDABE
  14 #define SUN_VTOC_SANITY          0x600DDEEE
  15
  16 int sun_partition(struct parsed_partitions *state)
  17 {
  18         int i;
  19         __be16 csum;
  20         int slot = 1;
  21         __be16 *ush;
  22         Sector sect;
  23         struct sun_disklabel {
  24                 unsigned char info[128];   /* Informative text string */
  25                 struct sun_vtoc {
  26                     __be32 version;     /* Layout version */
  27                     char   volume[8];   /* Volume name */
  28                     __be16 nparts;      /* Number of partitions */
  29                     struct sun_info {           /* Partition hdrs, sec 2 */
  30                         __be16 id;
  31                         __be16 flags;
  32                     } infos[8];
  33                     __be16 padding;     /* Alignment padding */
  34                     __be32 bootinfo[3];  /* Info needed by mboot */
  35                     __be32 sanity;       /* To verify vtoc sanity */
  36                     __be32 reserved[10]; /* Free space */
  37                     __be32 timestamp[8]; /* Partition timestamp */
  38                 } vtoc;
  39                 __be32 write_reinstruct; /* sectors to skip, writes */
  40                 __be32 read_reinstruct;  /* sectors to skip, reads */
  41                 unsigned char spare[148]; /* Padding */
  42                 __be16 rspeed;     /* Disk rotational speed */
  43                 __be16 pcylcount;  /* Physical cylinder count */
  44                 __be16 sparecyl;   /* extra sects per cylinder */
  45                 __be16 obs1;       /* gap1 */
  46                 __be16 obs2;       /* gap2 */
  47                 __be16 ilfact;     /* Interleave factor */
  48                 __be16 ncyl;       /* Data cylinder count */
  49                 __be16 nacyl;      /* Alt. cylinder count */
  50                 __be16 ntrks;      /* Tracks per cylinder */
  51                 __be16 nsect;      /* Sectors per track */
  52                 __be16 obs3;       /* bhead - Label head offset */
  53                 __be16 obs4;       /* ppart - Physical Partition */
  54                 struct sun_partition {
  55                         __be32 start_cylinder;
  56                         __be32 num_sectors;
  57                 } partitions[8];
  58                 __be16 magic;      /* Magic number */
  59                 __be16 csum;       /* Label xor'd checksum */
  60         } * label;
  61         struct sun_partition *p;
  62         unsigned long spc;
  63         char b[BDEVNAME_SIZE];
  64         int use_vtoc;
  65         int nparts;
  66
  67         label = read_part_sector(state, 0, &sect);
  68         if (!label)
  69                 return -1;
  70
  71         p = label->partitions;
  72         if (be16_to_cpu(label->magic) != SUN_LABEL_MAGIC) {
  73 /*              printk(KERN_INFO "Dev %s Sun disklabel: bad magic %04x\n",
  74                        bdevname(bdev, b), be16_to_cpu(label->magic)); */
  75                 put_dev_sector(sect);
  76                 return 0;
  77         }
  78         /* Look at the checksum */
  79         ush = ((__be16 *) (label+1)) - 1;
  80         for (csum = 0; ush >= ((__be16 *) label);)
  81                 csum ^= *ush--;
  82         if (csum) {
  83                 printk("Dev %s Sun disklabel: Csum bad, label corrupted\n",
  84                        bdevname(state->bdev, b));
  85                 put_dev_sector(sect);
  86                 return 0;
  87         }
  88
  89         /* Check to see if we can use the VTOC table */
  90         use_vtoc = ((be32_to_cpu(label->vtoc.sanity) == SUN_VTOC_SANITY) &&
  91                     (be32_to_cpu(label->vtoc.version) == 1) &&
  92                     (be16_to_cpu(label->vtoc.nparts) <= 8));
  93
  94         /* Use 8 partition entries if not specified in validated VTOC */
  95         nparts = (use_vtoc) ? be16_to_cpu(label->vtoc.nparts) : 8;
  96
  97         /*
  98          * So that old Linux-Sun partitions continue to work,
  99          * alow the VTOC to be used under the additional condition ...
 100          */
 101         use_vtoc = use_vtoc || !(label->vtoc.sanity ||
 102                                  label->vtoc.version || label->vtoc.nparts);
 103         spc = be16_to_cpu(label->ntrks) * be16_to_cpu(label->nsect);
 104         for (i = 0; i < nparts; i++, p++) {
 105                 unsigned long st_sector;
 106                 unsigned int num_sectors;
 107
 108                 st_sector = be32_to_cpu(p->start_cylinder) * spc;
 109                 num_sectors = be32_to_cpu(p->num_sectors);
 110                 if (num_sectors) {
 111                         put_partition(state, slot, st_sector, num_sectors);
 112                         state->parts[slot].flags = 0;
 113                         if (use_vtoc) {
 114                                 if (be16_to_cpu(label->vtoc.infos[i].id) == LINUX_RAID_PARTITION)
 115                                         state->parts[slot].flags |= ADDPART_FLAG_RAID;
 116                                 else if (be16_to_cpu(label->vtoc.infos[i].id) == SUN_WHOLE_DISK)
 117                                         state->parts[slot].flags |= ADDPART_FLAG_WHOLEDISK;
 118                         }
 119                 }
 120                 slot++;
 121         }
 122         strlcat(state->pp_buf, "\n", PAGE_SIZE);
 123         put_dev_sector(sect);
 124         return 1;
 125 }