block/partitions/sun.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  *  fs/partitions/sun.c
0004  *
0005  *  Code extracted from drivers/block/genhd.c
0006  *
0007  *  Copyright (C) 1991-1998  Linus Torvalds
0008  *  Re-organised Feb 1998 Russell King
0009  */
0010
0011 #include "check.h"
0012
0013 #define SUN_LABEL_MAGIC          0xDABE
0014 #define SUN_VTOC_SANITY          0x600DDEEE
0015
0016 enum {
0017     SUN_WHOLE_DISK = 5,
0018     LINUX_RAID_PARTITION = 0xfd,    /* autodetect RAID partition */
0019 };
0020
0021 int sun_partition(struct parsed_partitions *state)
0022 {
0023     int i;
0024     __be16 csum;
0025     int slot = 1;
0026     __be16 *ush;
0027     Sector sect;
0028     struct sun_disklabel {
0029         unsigned char info[128];   /* Informative text string */
0030         struct sun_vtoc {
0031             __be32 version;     /* Layout version */
0032             char   volume[8];   /* Volume name */
0033             __be16 nparts;      /* Number of partitions */
0034             struct sun_info {           /* Partition hdrs, sec 2 */
0035             __be16 id;
0036             __be16 flags;
0037             } infos[8];
0038             __be16 padding;     /* Alignment padding */
0039             __be32 bootinfo[3];  /* Info needed by mboot */
0040             __be32 sanity;       /* To verify vtoc sanity */
0041             __be32 reserved[10]; /* Free space */
0042             __be32 timestamp[8]; /* Partition timestamp */
0043         } vtoc;
0044         __be32 write_reinstruct; /* sectors to skip, writes */
0045         __be32 read_reinstruct;  /* sectors to skip, reads */
0046         unsigned char spare[148]; /* Padding */
0047         __be16 rspeed;     /* Disk rotational speed */
0048         __be16 pcylcount;  /* Physical cylinder count */
0049         __be16 sparecyl;   /* extra sects per cylinder */
0050         __be16 obs1;       /* gap1 */
0051         __be16 obs2;       /* gap2 */
0052         __be16 ilfact;     /* Interleave factor */
0053         __be16 ncyl;       /* Data cylinder count */
0054         __be16 nacyl;      /* Alt. cylinder count */
0055         __be16 ntrks;      /* Tracks per cylinder */
0056         __be16 nsect;      /* Sectors per track */
0057         __be16 obs3;       /* bhead - Label head offset */
0058         __be16 obs4;       /* ppart - Physical Partition */
0059         struct sun_partition {
0060             __be32 start_cylinder;
0061             __be32 num_sectors;
0062         } partitions[8];
0063         __be16 magic;      /* Magic number */
0064         __be16 csum;       /* Label xor'd checksum */
0065     } * label;
0066     struct sun_partition *p;
0067     unsigned long spc;
0068     int use_vtoc;
0069     int nparts;
0070
0071     label = read_part_sector(state, 0, &sect);
0072     if (!label)
0073         return -1;
0074
0075     p = label->partitions;
0076     if (be16_to_cpu(label->magic) != SUN_LABEL_MAGIC) {
0077 /*      printk(KERN_INFO "Dev %s Sun disklabel: bad magic %04x\n",
0078                state->disk->disk_name, be16_to_cpu(label->magic)); */
0079         put_dev_sector(sect);
0080         return 0;
0081     }
0082     /* Look at the checksum */
0083     ush = ((__be16 *) (label+1)) - 1;
0084     for (csum = 0; ush >= ((__be16 *) label);)
0085         csum ^= *ush--;
0086     if (csum) {
0087         printk("Dev %s Sun disklabel: Csum bad, label corrupted\n",
0088                state->disk->disk_name);
0089         put_dev_sector(sect);
0090         return 0;
0091     }
0092
0093     /* Check to see if we can use the VTOC table */
0094     use_vtoc = ((be32_to_cpu(label->vtoc.sanity) == SUN_VTOC_SANITY) &&
0095             (be32_to_cpu(label->vtoc.version) == 1) &&
0096             (be16_to_cpu(label->vtoc.nparts) <= 8));
0097
0098     /* Use 8 partition entries if not specified in validated VTOC */
0099     nparts = (use_vtoc) ? be16_to_cpu(label->vtoc.nparts) : 8;
0100
0101     /*
0102      * So that old Linux-Sun partitions continue to work,
0103      * alow the VTOC to be used under the additional condition ...
0104      */
0105     use_vtoc = use_vtoc || !(label->vtoc.sanity ||
0106                  label->vtoc.version || label->vtoc.nparts);
0107     spc = be16_to_cpu(label->ntrks) * be16_to_cpu(label->nsect);
0108     for (i = 0; i < nparts; i++, p++) {
0109         unsigned long st_sector;
0110         unsigned int num_sectors;
0111
0112         st_sector = be32_to_cpu(p->start_cylinder) * spc;
0113         num_sectors = be32_to_cpu(p->num_sectors);
0114         if (num_sectors) {
0115             put_partition(state, slot, st_sector, num_sectors);
0116             state->parts[slot].flags = 0;
0117             if (use_vtoc) {
0118                 if (be16_to_cpu(label->vtoc.infos[i].id) == LINUX_RAID_PARTITION)
0119                     state->parts[slot].flags |= ADDPART_FLAG_RAID;
0120                 else if (be16_to_cpu(label->vtoc.infos[i].id) == SUN_WHOLE_DISK)
0121                     state->parts[slot].flags |= ADDPART_FLAG_WHOLEDISK;
0122             }
0123         }
0124         slot++;
0125     }
0126     strlcat(state->pp_buf, "\n", PAGE_SIZE);
0127     put_dev_sector(sect);
0128     return 1;
0129 }