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