block/partitions/ibm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   4  *                  Volker Sameske <sameske@de.ibm.com>
   5  * Bugreports.to..: <Linux390@de.ibm.com>
   6  * Copyright IBM Corp. 1999, 2012
   7  */
   8
   9 #include <linux/buffer_head.h>
  10 #include <linux/hdreg.h>
  11 #include <linux/slab.h>
  12 #include <asm/dasd.h>
  13 #include <asm/ebcdic.h>
  14 #include <linux/uaccess.h>
  15 #include <asm/vtoc.h>
  16 #include <linux/module.h>
  17 #include <linux/dasd_mod.h>
  18
  19 #include "check.h"
  20
  21 union label_t {
  22         struct vtoc_volume_label_cdl vol;
  23         struct vtoc_volume_label_ldl lnx;
  24         struct vtoc_cms_label cms;
  25 };
  26
  27 /*
  28  * compute the block number from a
  29  * cyl-cyl-head-head structure
  30  */
  31 static sector_t cchh2blk(struct vtoc_cchh *ptr, struct hd_geometry *geo)
  32 {
  33         sector_t cyl;
  34         __u16 head;
  35
  36         /* decode cylinder and heads for large volumes */
  37         cyl = ptr->hh & 0xFFF0;
  38         cyl <<= 12;
  39         cyl |= ptr->cc;
  40         head = ptr->hh & 0x000F;
  41         return cyl * geo->heads * geo->sectors +
  42                head * geo->sectors;
  43 }
  44
  45 /*
  46  * compute the block number from a
  47  * cyl-cyl-head-head-block structure
  48  */
  49 static sector_t cchhb2blk(struct vtoc_cchhb *ptr, struct hd_geometry *geo)
  50 {
  51         sector_t cyl;
  52         __u16 head;
  53
  54         /* decode cylinder and heads for large volumes */
  55         cyl = ptr->hh & 0xFFF0;
  56         cyl <<= 12;
  57         cyl |= ptr->cc;
  58         head = ptr->hh & 0x000F;
  59         return  cyl * geo->heads * geo->sectors +
  60                 head * geo->sectors +
  61                 ptr->b;
  62 }
  63
  64 /* Volume Label Type/ID Length */
  65 #define DASD_VOL_TYPE_LEN       4
  66 #define DASD_VOL_ID_LEN         6
  67
  68 /* Volume Label Types */
  69 #define DASD_VOLLBL_TYPE_VOL1 0
  70 #define DASD_VOLLBL_TYPE_LNX1 1
  71 #define DASD_VOLLBL_TYPE_CMS1 2
  72
  73 struct dasd_vollabel {
  74         char *type;
  75         int idx;
  76 };
  77
  78 static struct dasd_vollabel dasd_vollabels[] = {
  79         [DASD_VOLLBL_TYPE_VOL1] = {
  80                 .type = "VOL1",
  81                 .idx = DASD_VOLLBL_TYPE_VOL1,
  82         },
  83         [DASD_VOLLBL_TYPE_LNX1] = {
  84                 .type = "LNX1",
  85                 .idx = DASD_VOLLBL_TYPE_LNX1,
  86         },
  87         [DASD_VOLLBL_TYPE_CMS1] = {
  88                 .type = "CMS1",
  89                 .idx = DASD_VOLLBL_TYPE_CMS1,
  90         },
  91 };
  92
  93 static int get_label_by_type(const char *type)
  94 {
  95         int i;
  96
  97         for (i = 0; i < ARRAY_SIZE(dasd_vollabels); i++) {
  98                 if (!memcmp(type, dasd_vollabels[i].type, DASD_VOL_TYPE_LEN))
  99                         return dasd_vollabels[i].idx;
 100         }
 101
 102         return -1;
 103 }
 104
 105 static int find_label(struct parsed_partitions *state,
 106                       dasd_information2_t *info,
 107                       struct hd_geometry *geo,
 108                       int blocksize,
 109                       sector_t *labelsect,
 110                       char name[],
 111                       char type[],
 112                       union label_t *label)
 113 {
 114         sector_t testsect[3];
 115         int i, testcount;
 116         Sector sect;
 117         void *data;
 118
 119         /* There a three places where we may find a valid label:
 120          * - on an ECKD disk it's block 2
 121          * - on an FBA disk it's block 1
 122          * - on an CMS formatted FBA disk it is sector 1, even if the block size
 123          *   is larger than 512 bytes (possible if the DIAG discipline is used)
 124          * If we have a valid info structure, then we know exactly which case we
 125          * have, otherwise we just search through all possebilities.
 126          */
 127         if (info) {
 128                 if ((info->cu_type == 0x6310 && info->dev_type == 0x9336) ||
 129                     (info->cu_type == 0x3880 && info->dev_type == 0x3370))
 130                         testsect[0] = info->label_block;
 131                 else
 132                         testsect[0] = info->label_block * (blocksize >> 9);
 133                 testcount = 1;
 134         } else {
 135                 testsect[0] = 1;
 136                 testsect[1] = (blocksize >> 9);
 137                 testsect[2] = 2 * (blocksize >> 9);
 138                 testcount = 3;
 139         }
 140         for (i = 0; i < testcount; ++i) {
 141                 data = read_part_sector(state, testsect[i], &sect);
 142                 if (data == NULL)
 143                         continue;
 144                 memcpy(label, data, sizeof(*label));
 145                 memcpy(type, data, DASD_VOL_TYPE_LEN);
 146                 EBCASC(type, DASD_VOL_TYPE_LEN);
 147                 put_dev_sector(sect);
 148                 switch (get_label_by_type(type)) {
 149                 case DASD_VOLLBL_TYPE_VOL1:
 150                         memcpy(name, label->vol.volid, DASD_VOL_ID_LEN);
 151                         EBCASC(name, DASD_VOL_ID_LEN);
 152                         *labelsect = testsect[i];
 153                         return 1;
 154                 case DASD_VOLLBL_TYPE_LNX1:
 155                 case DASD_VOLLBL_TYPE_CMS1:
 156                         memcpy(name, label->lnx.volid, DASD_VOL_ID_LEN);
 157                         EBCASC(name, DASD_VOL_ID_LEN);
 158                         *labelsect = testsect[i];
 159                         return 1;
 160                 default:
 161                         break;
 162                 }
 163         }
 164
 165         return 0;
 166 }
 167
 168 static int find_vol1_partitions(struct parsed_partitions *state,
 169                                 struct hd_geometry *geo,
 170                                 int blocksize,
 171                                 char name[],
 172                                 union label_t *label)
 173 {
 174         sector_t blk;
 175         int counter;
 176         char tmp[64];
 177         Sector sect;
 178         unsigned char *data;
 179         loff_t offset, size;
 180         struct vtoc_format1_label f1;
 181         int secperblk;
 182
 183         snprintf(tmp, sizeof(tmp), "VOL1/%8s:", name);
 184         strlcat(state->pp_buf, tmp, PAGE_SIZE);
 185         /*
 186          * get start of VTOC from the disk label and then search for format1
 187          * and format8 labels
 188          */
 189         secperblk = blocksize >> 9;
 190         blk = cchhb2blk(&label->vol.vtoc, geo) + 1;
 191         counter = 0;
 192         data = read_part_sector(state, blk * secperblk, &sect);
 193         while (data != NULL) {
 194                 memcpy(&f1, data, sizeof(struct vtoc_format1_label));
 195                 put_dev_sector(sect);
 196                 /* skip FMT4 / FMT5 / FMT7 labels */
 197                 if (f1.DS1FMTID == _ascebc['4']
 198                     || f1.DS1FMTID == _ascebc['5']
 199                     || f1.DS1FMTID == _ascebc['7']
 200                     || f1.DS1FMTID == _ascebc['9']) {
 201                         blk++;
 202                         data = read_part_sector(state, blk * secperblk, &sect);
 203                         continue;
 204                 }
 205                 /* only FMT1 and 8 labels valid at this point */
 206                 if (f1.DS1FMTID != _ascebc['1'] &&
 207                     f1.DS1FMTID != _ascebc['8'])
 208                         break;
 209                 /* OK, we got valid partition data */
 210                 offset = cchh2blk(&f1.DS1EXT1.llimit, geo);
 211                 size  = cchh2blk(&f1.DS1EXT1.ulimit, geo) -
 212                         offset + geo->sectors;
 213                 offset *= secperblk;
 214                 size *= secperblk;
 215                 if (counter >= state->limit)
 216                         break;
 217                 put_partition(state, counter + 1, offset, size);
 218                 counter++;
 219                 blk++;
 220                 data = read_part_sector(state, blk * secperblk, &sect);
 221         }
 222         strlcat(state->pp_buf, "\n", PAGE_SIZE);
 223
 224         if (!data)
 225                 return -1;
 226
 227         return 1;
 228 }
 229
 230 static int find_lnx1_partitions(struct parsed_partitions *state,
 231                                 struct hd_geometry *geo,
 232                                 int blocksize,
 233                                 char name[],
 234                                 union label_t *label,
 235                                 sector_t labelsect,
 236                                 sector_t nr_sectors,
 237                                 dasd_information2_t *info)
 238 {
 239         loff_t offset, geo_size, size;
 240         char tmp[64];
 241         int secperblk;
 242
 243         snprintf(tmp, sizeof(tmp), "LNX1/%8s:", name);
 244         strlcat(state->pp_buf, tmp, PAGE_SIZE);
 245         secperblk = blocksize >> 9;
 246         if (label->lnx.ldl_version == 0xf2) {
 247                 size = label->lnx.formatted_blocks * secperblk;
 248         } else {
 249                 /*
 250                  * Formated w/o large volume support. If the sanity check
 251                  * 'size based on geo == size based on nr_sectors' is true, then
 252                  * we can safely assume that we know the formatted size of
 253                  * the disk, otherwise we need additional information
 254                  * that we can only get from a real DASD device.
 255                  */
 256                 geo_size = geo->cylinders * geo->heads
 257                         * geo->sectors * secperblk;
 258                 size = nr_sectors;
 259                 if (size != geo_size) {
 260                         if (!info) {
 261                                 strlcat(state->pp_buf, "\n", PAGE_SIZE);
 262                                 return 1;
 263                         }
 264                         if (!strcmp(info->type, "ECKD"))
 265                                 if (geo_size < size)
 266                                         size = geo_size;
 267                         /* else keep size based on nr_sectors */
 268                 }
 269         }
 270         /* first and only partition starts in the first block after the label */
 271         offset = labelsect + secperblk;
 272         put_partition(state, 1, offset, size - offset);
 273         strlcat(state->pp_buf, "\n", PAGE_SIZE);
 274         return 1;
 275 }
 276
 277 static int find_cms1_partitions(struct parsed_partitions *state,
 278                                 struct hd_geometry *geo,
 279                                 int blocksize,
 280                                 char name[],
 281                                 union label_t *label,
 282                                 sector_t labelsect)
 283 {
 284         loff_t offset, size;
 285         char tmp[64];
 286         int secperblk;
 287
 288         /*
 289          * VM style CMS1 labeled disk
 290          */
 291         blocksize = label->cms.block_size;
 292         secperblk = blocksize >> 9;
 293         if (label->cms.disk_offset != 0) {
 294                 snprintf(tmp, sizeof(tmp), "CMS1/%8s(MDSK):", name);
 295                 strlcat(state->pp_buf, tmp, PAGE_SIZE);
 296                 /* disk is reserved minidisk */
 297                 offset = label->cms.disk_offset * secperblk;
 298                 size = (label->cms.block_count - 1) * secperblk;
 299         } else {
 300                 snprintf(tmp, sizeof(tmp), "CMS1/%8s:", name);
 301                 strlcat(state->pp_buf, tmp, PAGE_SIZE);
 302                 /*
 303                  * Special case for FBA devices:
 304                  * If an FBA device is CMS formatted with blocksize > 512 byte
 305                  * and the DIAG discipline is used, then the CMS label is found
 306                  * in sector 1 instead of block 1. However, the partition is
 307                  * still supposed to start in block 2.
 308                  */
 309                 if (labelsect == 1)
 310                         offset = 2 * secperblk;
 311                 else
 312                         offset = labelsect + secperblk;
 313                 size = label->cms.block_count * secperblk;
 314         }
 315
 316         put_partition(state, 1, offset, size-offset);
 317         strlcat(state->pp_buf, "\n", PAGE_SIZE);
 318         return 1;
 319 }
 320
 321
 322 /*
 323  * This is the main function, called by check.c
 324  */
 325 int ibm_partition(struct parsed_partitions *state)
 326 {
 327         int (*fn)(struct gendisk *disk, dasd_information2_t *info);
 328         struct gendisk *disk = state->disk;
 329         struct block_device *bdev = disk->part0;
 330         int blocksize, res;
 331         loff_t offset, size;
 332         sector_t nr_sectors;
 333         dasd_information2_t *info;
 334         struct hd_geometry *geo;
 335         char type[DASD_VOL_TYPE_LEN + 1] = "";
 336         char name[DASD_VOL_ID_LEN + 1] = "";
 337         sector_t labelsect;
 338         union label_t *label;
 339
 340         res = 0;
 341         if (!disk->fops->getgeo)
 342                 goto out_exit;
 343         fn = symbol_get(dasd_biodasdinfo);
 344         blocksize = bdev_logical_block_size(bdev);
 345         if (blocksize <= 0)
 346                 goto out_symbol;
 347         nr_sectors = bdev_nr_sectors(bdev);
 348         if (nr_sectors == 0)
 349                 goto out_symbol;
 350         info = kmalloc(sizeof(dasd_information2_t), GFP_KERNEL);
 351         if (info == NULL)
 352                 goto out_symbol;
 353         geo = kmalloc(sizeof(struct hd_geometry), GFP_KERNEL);
 354         if (geo == NULL)
 355                 goto out_nogeo;
 356         label = kmalloc(sizeof(union label_t), GFP_KERNEL);
 357         if (label == NULL)
 358                 goto out_nolab;
 359         /* set start if not filled by getgeo function e.g. virtblk */
 360         geo->start = get_start_sect(bdev);
 361         if (disk->fops->getgeo(bdev, geo))
 362                 goto out_freeall;
 363         if (!fn || fn(disk, info)) {
 364                 kfree(info);
 365                 info = NULL;
 366         }
 367
 368         if (find_label(state, info, geo, blocksize, &labelsect, name, type, label)) {
 369                 switch (get_label_by_type(type)) {
 370                 case DASD_VOLLBL_TYPE_VOL1:
 371                         res = find_vol1_partitions(state, geo, blocksize, name,
 372                                                    label);
 373                         break;
 374                 case DASD_VOLLBL_TYPE_LNX1:
 375                         res = find_lnx1_partitions(state, geo, blocksize, name,
 376                                                    label, labelsect, nr_sectors,
 377                                                    info);
 378                         break;
 379                 case DASD_VOLLBL_TYPE_CMS1:
 380                         res = find_cms1_partitions(state, geo, blocksize, name,
 381                                                    label, labelsect);
 382                         break;
 383                 }
 384         } else if (info) {
 385                 /*
 386                  * ugly but needed for backward compatibility:
 387                  * If the block device is a DASD (i.e. BIODASDINFO2 works),
 388                  * then we claim it in any case, even though it has no valid
 389                  * label. If it has the LDL format, then we simply define a
 390                  * partition as if it had an LNX1 label.
 391                  */
 392                 res = 1;
 393                 if (info->format == DASD_FORMAT_LDL) {
 394                         strlcat(state->pp_buf, "(nonl)", PAGE_SIZE);
 395                         size = nr_sectors;
 396                         offset = (info->label_block + 1) * (blocksize >> 9);
 397                         put_partition(state, 1, offset, size-offset);
 398                         strlcat(state->pp_buf, "\n", PAGE_SIZE);
 399                 }
 400         } else
 401                 res = 0;
 402
 403 out_freeall:
 404         kfree(label);
 405 out_nolab:
 406         kfree(geo);
 407 out_nogeo:
 408         kfree(info);
 409 out_symbol:
 410         if (fn)
 411                 symbol_put(dasd_biodasdinfo);
 412 out_exit:
 413         return res;
 414 }