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 enum {
  17         SUN_WHOLE_DISK = 5,
  18         LINUX_RAID_PARTITION = 0xfd,    /* autodetect RAID partition */
  19 };
  20
  21 int sun_partition(struct parsed_partitions *state)
  22 {
  23         int i;
  24         __be16 csum;
  25         int slot = 1;
  26         __be16 *ush;
  27         Sector sect;
  28         struct sun_disklabel {
  29                 unsigned char info[128];   /* Informative text string */
  30                 struct sun_vtoc {
  31                     __be32 version;     /* Layout version */
  32                     char   volume[8];   /* Volume name */
  33                     __be16 nparts;      /* Number of partitions */
  34                     struct sun_info {           /* Partition hdrs, sec 2 */
  35                         __be16 id;
  36                         __be16 flags;
  37                     } infos[8];
  38                     __be16 padding;     /* Alignment padding */
  39                     __be32 bootinfo[3];  /* Info needed by mboot */
  40                     __be32 sanity;       /* To verify vtoc sanity */
  41                     __be32 reserved[10]; /* Free space */
  42                     __be32 timestamp[8]; /* Partition timestamp */
  43                 } vtoc;
  44                 __be32 write_reinstruct; /* sectors to skip, writes */
  45                 __be32 read_reinstruct;  /* sectors to skip, reads */
  46                 unsigned char spare[148]; /* Padding */
  47                 __be16 rspeed;     /* Disk rotational speed */
  48                 __be16 pcylcount;  /* Physical cylinder count */
  49                 __be16 sparecyl;   /* extra sects per cylinder */
  50                 __be16 obs1;       /* gap1 */
  51                 __be16 obs2;       /* gap2 */
  52                 __be16 ilfact;     /* Interleave factor */
  53                 __be16 ncyl;       /* Data cylinder count */
  54                 __be16 nacyl;      /* Alt. cylinder count */
  55                 __be16 ntrks;      /* Tracks per cylinder */
  56                 __be16 nsect;      /* Sectors per track */
  57                 __be16 obs3;       /* bhead - Label head offset */
  58                 __be16 obs4;       /* ppart - Physical Partition */
  59                 struct sun_partition {
  60                         __be32 start_cylinder;
  61                         __be32 num_sectors;
  62                 } partitions[8];
  63                 __be16 magic;      /* Magic number */
  64                 __be16 csum;       /* Label xor'd checksum */
  65         } * label;
  66         struct sun_partition *p;
  67         unsigned long spc;
  68         char b[BDEVNAME_SIZE];
  69         int use_vtoc;
  70         int nparts;
  71
  72         label = read_part_sector(state, 0, &sect);
  73         if (!label)
  74                 return -1;
  75
  76         p = label->partitions;
  77         if (be16_to_cpu(label->magic) != SUN_LABEL_MAGIC) {
  78 /*              printk(KERN_INFO "Dev %s Sun disklabel: bad magic %04x\n",
  79                        bdevname(bdev, b), be16_to_cpu(label->magic)); */
  80                 put_dev_sector(sect);
  81                 return 0;
  82         }
  83         /* Look at the checksum */
  84         ush = ((__be16 *) (label+1)) - 1;
  85         for (csum = 0; ush >= ((__be16 *) label);)
  86                 csum ^= *ush--;
  87         if (csum) {
  88                 printk("Dev %s Sun disklabel: Csum bad, label corrupted\n",
  89                        bdevname(state->bdev, b));
  90                 put_dev_sector(sect);
  91                 return 0;
  92         }
  93
  94         /* Check to see if we can use the VTOC table */
  95         use_vtoc = ((be32_to_cpu(label->vtoc.sanity) == SUN_VTOC_SANITY) &&
  96                     (be32_to_cpu(label->vtoc.version) == 1) &&
  97                     (be16_to_cpu(label->vtoc.nparts) <= 8));
  98
  99         /* Use 8 partition entries if not specified in validated VTOC */
 100         nparts = (use_vtoc) ? be16_to_cpu(label->vtoc.nparts) : 8;
 101
 102         /*
 103          * So that old Linux-Sun partitions continue to work,
 104          * alow the VTOC to be used under the additional condition ...
 105          */
 106         use_vtoc = use_vtoc || !(label->vtoc.sanity ||
 107                                  label->vtoc.version || label->vtoc.nparts);
 108         spc = be16_to_cpu(label->ntrks) * be16_to_cpu(label->nsect);
 109         for (i = 0; i < nparts; i++, p++) {
 110                 unsigned long st_sector;
 111                 unsigned int num_sectors;
 112
 113                 st_sector = be32_to_cpu(p->start_cylinder) * spc;
 114                 num_sectors = be32_to_cpu(p->num_sectors);
 115                 if (num_sectors) {
 116                         put_partition(state, slot, st_sector, num_sectors);
 117                         state->parts[slot].flags = 0;
 118                         if (use_vtoc) {
 119                                 if (be16_to_cpu(label->vtoc.infos[i].id) == LINUX_RAID_PARTITION)
 120                                         state->parts[slot].flags |= ADDPART_FLAG_RAID;
 121                                 else if (be16_to_cpu(label->vtoc.infos[i].id) == SUN_WHOLE_DISK)
 122                                         state->parts[slot].flags |= ADDPART_FLAG_WHOLEDISK;
 123                         }
 124                 }
 125                 slot++;
 126         }
 127         strlcat(state->pp_buf, "\n", PAGE_SIZE);
 128         put_dev_sector(sect);
 129         return 1;
 130 }