LXR linux/block/partitions/sgi.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 *  fs/partitions/sgi.c
   4 *
   5 *  Code extracted from drivers/block/genhd.c
   6 */
   7
   8#include "check.h"
   9#include "sgi.h"
  10
  11struct sgi_disklabel {
  12        __be32 magic_mushroom;          /* Big fat spliff... */
  13        __be16 root_part_num;           /* Root partition number */
  14        __be16 swap_part_num;           /* Swap partition number */
  15        s8 boot_file[16];               /* Name of boot file for ARCS */
  16        u8 _unused0[48];                /* Device parameter useless crapola.. */
  17        struct sgi_volume {
  18                s8 name[8];             /* Name of volume */
  19                __be32 block_num;               /* Logical block number */
  20                __be32 num_bytes;               /* How big, in bytes */
  21        } volume[15];
  22        struct sgi_partition {
  23                __be32 num_blocks;              /* Size in logical blocks */
  24                __be32 first_block;     /* First logical block */
  25                __be32 type;            /* Type of this partition */
  26        } partitions[16];
  27        __be32 csum;                    /* Disk label checksum */
  28        __be32 _unused1;                        /* Padding */
  29};
  30
  31int sgi_partition(struct parsed_partitions *state)
  32{
  33        int i, csum;
  34        __be32 magic;
  35        int slot = 1;
  36        unsigned int start, blocks;
  37        __be32 *ui, cs;
  38        Sector sect;
  39        struct sgi_disklabel *label;
  40        struct sgi_partition *p;
  41        char b[BDEVNAME_SIZE];
  42
  43        label = read_part_sector(state, 0, &sect);
  44        if (!label)
  45                return -1;
  46        p = &label->partitions[0];
  47        magic = label->magic_mushroom;
  48        if(be32_to_cpu(magic) != SGI_LABEL_MAGIC) {
  49                /*printk("Dev %s SGI disklabel: bad magic %08x\n",
  50                       bdevname(bdev, b), be32_to_cpu(magic));*/
  51                put_dev_sector(sect);
  52                return 0;
  53        }
  54        ui = ((__be32 *) (label + 1)) - 1;
  55        for(csum = 0; ui >= ((__be32 *) label);) {
  56                cs = *ui--;
  57                csum += be32_to_cpu(cs);
  58        }
  59        if(csum) {
  60                printk(KERN_WARNING "Dev %s SGI disklabel: csum bad, label corrupted\n",
  61                       bdevname(state->bdev, b));
  62                put_dev_sector(sect);
  63                return 0;
  64        }
  65        /* All SGI disk labels have 16 partitions, disks under Linux only
  66         * have 15 minor's.  Luckily there are always a few zero length
  67         * partitions which we don't care about so we never overflow the
  68         * current_minor.
  69         */
  70        for(i = 0; i < 16; i++, p++) {
  71                blocks = be32_to_cpu(p->num_blocks);
  72                start  = be32_to_cpu(p->first_block);
  73                if (blocks) {
  74                        put_partition(state, slot, start, blocks);
  75                        if (be32_to_cpu(p->type) == LINUX_RAID_PARTITION)
  76                                state->parts[slot].flags = ADDPART_FLAG_RAID;
  77                }
  78                slot++;
  79        }
  80        strlcat(state->pp_buf, "\n", PAGE_SIZE);
  81        put_dev_sector(sect);
  82        return 1;
  83}
  84