drivers/s390/block/dasd_ioctl.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Author(s)......: Holger Smolinski <[email protected]>
   4  *                  Horst Hummel <[email protected]>
   5  *                  Carsten Otte <[email protected]>
   6  *                  Martin Schwidefsky <[email protected]>
   7  * Bugreports.to..: <[email protected]>
   8  * Copyright IBM Corp. 1999, 2001
   9  *
  10  * i/o controls for the dasd driver.
  11  */
  12
  13 #define KMSG_COMPONENT "dasd"
  14
  15 #include <linux/interrupt.h>
  16 #include <linux/compat.h>
  17 #include <linux/major.h>
  18 #include <linux/fs.h>
  19 #include <linux/blkpg.h>
  20 #include <linux/slab.h>
  21 #include <asm/ccwdev.h>
  22 #include <asm/schid.h>
  23 #include <asm/cmb.h>
  24 #include <linux/uaccess.h>
  25 #include <linux/dasd_mod.h>
  26
  27 /* This is ugly... */
  28 #define PRINTK_HEADER "dasd_ioctl:"
  29
  30 #include "dasd_int.h"
  31
  32
  33 static int
  34 dasd_ioctl_api_version(void __user *argp)
  35 {
  36         int ver = DASD_API_VERSION;
  37         return put_user(ver, (int __user *)argp);
  38 }
  39
  40 /*
  41  * Enable device.
  42  * used by dasdfmt after BIODASDDISABLE to retrigger blocksize detection
  43  */
  44 static int
  45 dasd_ioctl_enable(struct block_device *bdev)
  46 {
  47         struct dasd_device *base;
  48
  49         if (!capable(CAP_SYS_ADMIN))
  50                 return -EACCES;
  51
  52         base = dasd_device_from_gendisk(bdev->bd_disk);
  53         if (!base)
  54                 return -ENODEV;
  55
  56         dasd_enable_device(base);
  57         /* Formatting the dasd device can change the capacity. */
  58         mutex_lock(&bdev->bd_mutex);
  59         i_size_write(bdev->bd_inode,
  60                      (loff_t)get_capacity(base->block->gdp) << 9);
  61         mutex_unlock(&bdev->bd_mutex);
  62         dasd_put_device(base);
  63         return 0;
  64 }
  65
  66 /*
  67  * Disable device.
  68  * Used by dasdfmt. Disable I/O operations but allow ioctls.
  69  */
  70 static int
  71 dasd_ioctl_disable(struct block_device *bdev)
  72 {
  73         struct dasd_device *base;
  74
  75         if (!capable(CAP_SYS_ADMIN))
  76                 return -EACCES;
  77
  78         base = dasd_device_from_gendisk(bdev->bd_disk);
  79         if (!base)
  80                 return -ENODEV;
  81         /*
  82          * Man this is sick. We don't do a real disable but only downgrade
  83          * the device to DASD_STATE_BASIC. The reason is that dasdfmt uses
  84          * BIODASDDISABLE to disable accesses to the device via the block
  85          * device layer but it still wants to do i/o on the device by
  86          * using the BIODASDFMT ioctl. Therefore the correct state for the
  87          * device is DASD_STATE_BASIC that allows to do basic i/o.
  88          */
  89         dasd_set_target_state(base, DASD_STATE_BASIC);
  90         /*
  91          * Set i_size to zero, since read, write, etc. check against this
  92          * value.
  93          */
  94         mutex_lock(&bdev->bd_mutex);
  95         i_size_write(bdev->bd_inode, 0);
  96         mutex_unlock(&bdev->bd_mutex);
  97         dasd_put_device(base);
  98         return 0;
  99 }
 100
 101 /*
 102  * Quiesce device.
 103  */
 104 static int dasd_ioctl_quiesce(struct dasd_block *block)
 105 {
 106         unsigned long flags;
 107         struct dasd_device *base;
 108
 109         base = block->base;
 110         if (!capable (CAP_SYS_ADMIN))
 111                 return -EACCES;
 112
 113         pr_info("%s: The DASD has been put in the quiesce "
 114                 "state\n", dev_name(&base->cdev->dev));
 115         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
 116         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
 117         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
 118         return 0;
 119 }
 120
 121
 122 /*
 123  * Resume device.
 124  */
 125 static int dasd_ioctl_resume(struct dasd_block *block)
 126 {
 127         unsigned long flags;
 128         struct dasd_device *base;
 129
 130         base = block->base;
 131         if (!capable (CAP_SYS_ADMIN))
 132                 return -EACCES;
 133
 134         pr_info("%s: I/O operations have been resumed "
 135                 "on the DASD\n", dev_name(&base->cdev->dev));
 136         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
 137         dasd_device_remove_stop_bits(base, DASD_STOPPED_QUIESCE);
 138         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
 139
 140         dasd_schedule_block_bh(block);
 141         return 0;
 142 }
 143
 144 /*
 145  * Abort all failfast I/O on a device.
 146  */
 147 static int dasd_ioctl_abortio(struct dasd_block *block)
 148 {
 149         unsigned long flags;
 150         struct dasd_device *base;
 151         struct dasd_ccw_req *cqr, *n;
 152
 153         base = block->base;
 154         if (!capable(CAP_SYS_ADMIN))
 155                 return -EACCES;
 156
 157         if (test_and_set_bit(DASD_FLAG_ABORTALL, &base->flags))
 158                 return 0;
 159         DBF_DEV_EVENT(DBF_NOTICE, base, "%s", "abortall flag set");
 160
 161         spin_lock_irqsave(&block->request_queue_lock, flags);
 162         spin_lock(&block->queue_lock);
 163         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
 164                 if (test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
 165                     cqr->callback_data &&
 166                     cqr->callback_data != DASD_SLEEPON_START_TAG &&
 167                     cqr->callback_data != DASD_SLEEPON_END_TAG) {
 168                         spin_unlock(&block->queue_lock);
 169                         blk_abort_request(cqr->callback_data);
 170                         spin_lock(&block->queue_lock);
 171                 }
 172         }
 173         spin_unlock(&block->queue_lock);
 174         spin_unlock_irqrestore(&block->request_queue_lock, flags);
 175
 176         dasd_schedule_block_bh(block);
 177         return 0;
 178 }
 179
 180 /*
 181  * Allow I/O on a device
 182  */
 183 static int dasd_ioctl_allowio(struct dasd_block *block)
 184 {
 185         struct dasd_device *base;
 186
 187         base = block->base;
 188         if (!capable(CAP_SYS_ADMIN))
 189                 return -EACCES;
 190
 191         if (test_and_clear_bit(DASD_FLAG_ABORTALL, &base->flags))
 192                 DBF_DEV_EVENT(DBF_NOTICE, base, "%s", "abortall flag unset");
 193
 194         return 0;
 195 }
 196
 197 /*
 198  * performs formatting of _device_ according to _fdata_
 199  * Note: The discipline's format_function is assumed to deliver formatting
 200  * commands to format multiple units of the device. In terms of the ECKD
 201  * devices this means CCWs are generated to format multiple tracks.
 202  */
 203 static int
 204 dasd_format(struct dasd_block *block, struct format_data_t *fdata)
 205 {
 206         struct dasd_device *base;
 207         int rc;
 208
 209         base = block->base;
 210         if (base->discipline->format_device == NULL)
 211                 return -EPERM;
 212
 213         if (base->state != DASD_STATE_BASIC) {
 214                 pr_warn("%s: The DASD cannot be formatted while it is enabled\n",
 215                         dev_name(&base->cdev->dev));
 216                 return -EBUSY;
 217         }
 218
 219         DBF_DEV_EVENT(DBF_NOTICE, base,
 220                       "formatting units %u to %u (%u B blocks) flags %u",
 221                       fdata->start_unit,
 222                       fdata->stop_unit, fdata->blksize, fdata->intensity);
 223
 224         /* Since dasdfmt keeps the device open after it was disabled,
 225          * there still exists an inode for this device.
 226          * We must update i_blkbits, otherwise we might get errors when
 227          * enabling the device later.
 228          */
 229         if (fdata->start_unit == 0) {
 230                 struct block_device *bdev = bdget_disk(block->gdp, 0);
 231                 bdev->bd_inode->i_blkbits = blksize_bits(fdata->blksize);
 232                 bdput(bdev);
 233         }
 234
 235         rc = base->discipline->format_device(base, fdata, 1);
 236         if (rc == -EAGAIN)
 237                 rc = base->discipline->format_device(base, fdata, 0);
 238
 239         return rc;
 240 }
 241
 242 static int dasd_check_format(struct dasd_block *block,
 243                              struct format_check_t *cdata)
 244 {
 245         struct dasd_device *base;
 246         int rc;
 247
 248         base = block->base;
 249         if (!base->discipline->check_device_format)
 250                 return -ENOTTY;
 251
 252         rc = base->discipline->check_device_format(base, cdata, 1);
 253         if (rc == -EAGAIN)
 254                 rc = base->discipline->check_device_format(base, cdata, 0);
 255
 256         return rc;
 257 }
 258
 259 /*
 260  * Format device.
 261  */
 262 static int
 263 dasd_ioctl_format(struct block_device *bdev, void __user *argp)
 264 {
 265         struct dasd_device *base;
 266         struct format_data_t fdata;
 267         int rc;
 268
 269         if (!capable(CAP_SYS_ADMIN))
 270                 return -EACCES;
 271         if (!argp)
 272                 return -EINVAL;
 273         base = dasd_device_from_gendisk(bdev->bd_disk);
 274         if (!base)
 275                 return -ENODEV;
 276         if (base->features & DASD_FEATURE_READONLY ||
 277             test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
 278                 dasd_put_device(base);
 279                 return -EROFS;
 280         }
 281         if (copy_from_user(&fdata, argp, sizeof(struct format_data_t))) {
 282                 dasd_put_device(base);
 283                 return -EFAULT;
 284         }
 285         if (bdev != bdev->bd_contains) {
 286                 pr_warn("%s: The specified DASD is a partition and cannot be formatted\n",
 287                         dev_name(&base->cdev->dev));
 288                 dasd_put_device(base);
 289                 return -EINVAL;
 290         }
 291         rc = dasd_format(base->block, &fdata);
 292         dasd_put_device(base);
 293
 294         return rc;
 295 }
 296
 297 /*
 298  * Check device format
 299  */
 300 static int dasd_ioctl_check_format(struct block_device *bdev, void __user *argp)
 301 {
 302         struct format_check_t cdata;
 303         struct dasd_device *base;
 304         int rc = 0;
 305
 306         if (!argp)
 307                 return -EINVAL;
 308
 309         base = dasd_device_from_gendisk(bdev->bd_disk);
 310         if (!base)
 311                 return -ENODEV;
 312         if (bdev != bdev->bd_contains) {
 313                 pr_warn("%s: The specified DASD is a partition and cannot be checked\n",
 314                         dev_name(&base->cdev->dev));
 315                 rc = -EINVAL;
 316                 goto out_err;
 317         }
 318
 319         if (copy_from_user(&cdata, argp, sizeof(cdata))) {
 320                 rc = -EFAULT;
 321                 goto out_err;
 322         }
 323
 324         rc = dasd_check_format(base->block, &cdata);
 325         if (rc)
 326                 goto out_err;
 327
 328         if (copy_to_user(argp, &cdata, sizeof(cdata)))
 329                 rc = -EFAULT;
 330
 331 out_err:
 332         dasd_put_device(base);
 333
 334         return rc;
 335 }
 336
 337 static int dasd_release_space(struct dasd_device *device,
 338                               struct format_data_t *rdata)
 339 {
 340         if (!device->discipline->is_ese && !device->discipline->is_ese(device))
 341                 return -ENOTSUPP;
 342         if (!device->discipline->release_space)
 343                 return -ENOTSUPP;
 344
 345         return device->discipline->release_space(device, rdata);
 346 }
 347
 348 /*
 349  * Release allocated space
 350  */
 351 static int dasd_ioctl_release_space(struct block_device *bdev, void __user *argp)
 352 {
 353         struct format_data_t rdata;
 354         struct dasd_device *base;
 355         int rc = 0;
 356
 357         if (!capable(CAP_SYS_ADMIN))
 358                 return -EACCES;
 359         if (!argp)
 360                 return -EINVAL;
 361
 362         base = dasd_device_from_gendisk(bdev->bd_disk);
 363         if (!base)
 364                 return -ENODEV;
 365         if (base->features & DASD_FEATURE_READONLY ||
 366             test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
 367                 rc = -EROFS;
 368                 goto out_err;
 369         }
 370         if (bdev != bdev->bd_contains) {
 371                 pr_warn("%s: The specified DASD is a partition and tracks cannot be released\n",
 372                         dev_name(&base->cdev->dev));
 373                 rc = -EINVAL;
 374                 goto out_err;
 375         }
 376
 377         if (copy_from_user(&rdata, argp, sizeof(rdata))) {
 378                 rc = -EFAULT;
 379                 goto out_err;
 380         }
 381
 382         rc = dasd_release_space(base, &rdata);
 383
 384 out_err:
 385         dasd_put_device(base);
 386
 387         return rc;
 388 }
 389
 390 #ifdef CONFIG_DASD_PROFILE
 391 /*
 392  * Reset device profile information
 393  */
 394 static int dasd_ioctl_reset_profile(struct dasd_block *block)
 395 {
 396         dasd_profile_reset(&block->profile);
 397         return 0;
 398 }
 399
 400 /*
 401  * Return device profile information
 402  */
 403 static int dasd_ioctl_read_profile(struct dasd_block *block, void __user *argp)
 404 {
 405         struct dasd_profile_info_t *data;
 406         int rc = 0;
 407
 408         data = kmalloc(sizeof(*data), GFP_KERNEL);
 409         if (!data)
 410                 return -ENOMEM;
 411
 412         spin_lock_bh(&block->profile.lock);
 413         if (block->profile.data) {
 414                 data->dasd_io_reqs = block->profile.data->dasd_io_reqs;
 415                 data->dasd_io_sects = block->profile.data->dasd_io_sects;
 416                 memcpy(data->dasd_io_secs, block->profile.data->dasd_io_secs,
 417                        sizeof(data->dasd_io_secs));
 418                 memcpy(data->dasd_io_times, block->profile.data->dasd_io_times,
 419                        sizeof(data->dasd_io_times));
 420                 memcpy(data->dasd_io_timps, block->profile.data->dasd_io_timps,
 421                        sizeof(data->dasd_io_timps));
 422                 memcpy(data->dasd_io_time1, block->profile.data->dasd_io_time1,
 423                        sizeof(data->dasd_io_time1));
 424                 memcpy(data->dasd_io_time2, block->profile.data->dasd_io_time2,
 425                        sizeof(data->dasd_io_time2));
 426                 memcpy(data->dasd_io_time2ps,
 427                        block->profile.data->dasd_io_time2ps,
 428                        sizeof(data->dasd_io_time2ps));
 429                 memcpy(data->dasd_io_time3, block->profile.data->dasd_io_time3,
 430                        sizeof(data->dasd_io_time3));
 431                 memcpy(data->dasd_io_nr_req,
 432                        block->profile.data->dasd_io_nr_req,
 433                        sizeof(data->dasd_io_nr_req));
 434                 spin_unlock_bh(&block->profile.lock);
 435         } else {
 436                 spin_unlock_bh(&block->profile.lock);
 437                 rc = -EIO;
 438                 goto out;
 439         }
 440         if (copy_to_user(argp, data, sizeof(*data)))
 441                 rc = -EFAULT;
 442 out:
 443         kfree(data);
 444         return rc;
 445 }
 446 #else
 447 static int dasd_ioctl_reset_profile(struct dasd_block *block)
 448 {
 449         return -ENOTTY;
 450 }
 451
 452 static int dasd_ioctl_read_profile(struct dasd_block *block, void __user *argp)
 453 {
 454         return -ENOTTY;
 455 }
 456 #endif
 457
 458 /*
 459  * Return dasd information. Used for BIODASDINFO and BIODASDINFO2.
 460  */
 461 static int __dasd_ioctl_information(struct dasd_block *block,
 462                 struct dasd_information2_t *dasd_info)
 463 {
 464         struct subchannel_id sch_id;
 465         struct ccw_dev_id dev_id;
 466         struct dasd_device *base;
 467         struct ccw_device *cdev;
 468         struct list_head *l;
 469         unsigned long flags;
 470         int rc;
 471
 472         base = block->base;
 473         if (!base->discipline || !base->discipline->fill_info)
 474                 return -EINVAL;
 475
 476         rc = base->discipline->fill_info(base, dasd_info);
 477         if (rc)
 478                 return rc;
 479
 480         cdev = base->cdev;
 481         ccw_device_get_id(cdev, &dev_id);
 482         ccw_device_get_schid(cdev, &sch_id);
 483
 484         dasd_info->devno = dev_id.devno;
 485         dasd_info->schid = sch_id.sch_no;
 486         dasd_info->cu_type = cdev->id.cu_type;
 487         dasd_info->cu_model = cdev->id.cu_model;
 488         dasd_info->dev_type = cdev->id.dev_type;
 489         dasd_info->dev_model = cdev->id.dev_model;
 490         dasd_info->status = base->state;
 491         /*
 492          * The open_count is increased for every opener, that includes
 493          * the blkdev_get in dasd_scan_partitions.
 494          * This must be hidden from user-space.
 495          */
 496         dasd_info->open_count = atomic_read(&block->open_count);
 497         if (!block->bdev)
 498                 dasd_info->open_count++;
 499
 500         /*
 501          * check if device is really formatted
 502          * LDL / CDL was returned by 'fill_info'
 503          */
 504         if ((base->state < DASD_STATE_READY) ||
 505             (dasd_check_blocksize(block->bp_block)))
 506                 dasd_info->format = DASD_FORMAT_NONE;
 507
 508         dasd_info->features |=
 509                 ((base->features & DASD_FEATURE_READONLY) != 0);
 510
 511         memcpy(dasd_info->type, base->discipline->name, 4);
 512
 513         spin_lock_irqsave(&block->queue_lock, flags);
 514         list_for_each(l, &base->ccw_queue)
 515                 dasd_info->chanq_len++;
 516         spin_unlock_irqrestore(&block->queue_lock, flags);
 517         return 0;
 518 }
 519
 520 static int dasd_ioctl_information(struct dasd_block *block, void __user *argp,
 521                 size_t copy_size)
 522 {
 523         struct dasd_information2_t *dasd_info;
 524         int error;
 525
 526         dasd_info = kzalloc(sizeof(*dasd_info), GFP_KERNEL);
 527         if (!dasd_info)
 528                 return -ENOMEM;
 529
 530         error = __dasd_ioctl_information(block, dasd_info);
 531         if (!error && copy_to_user(argp, dasd_info, copy_size))
 532                 error = -EFAULT;
 533         kfree(dasd_info);
 534         return error;
 535 }
 536
 537 /*
 538  * Set read only
 539  */
 540 static int
 541 dasd_ioctl_set_ro(struct block_device *bdev, void __user *argp)
 542 {
 543         struct dasd_device *base;
 544         int intval, rc;
 545
 546         if (!capable(CAP_SYS_ADMIN))
 547                 return -EACCES;
 548         if (bdev != bdev->bd_contains)
 549                 // ro setting is not allowed for partitions
 550                 return -EINVAL;
 551         if (get_user(intval, (int __user *)argp))
 552                 return -EFAULT;
 553         base = dasd_device_from_gendisk(bdev->bd_disk);
 554         if (!base)
 555                 return -ENODEV;
 556         if (!intval && test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
 557                 dasd_put_device(base);
 558                 return -EROFS;
 559         }
 560         set_disk_ro(bdev->bd_disk, intval);
 561         rc = dasd_set_feature(base->cdev, DASD_FEATURE_READONLY, intval);
 562         dasd_put_device(base);
 563         return rc;
 564 }
 565
 566 static int dasd_ioctl_readall_cmb(struct dasd_block *block, unsigned int cmd,
 567                                   struct cmbdata __user *argp)
 568 {
 569         size_t size = _IOC_SIZE(cmd);
 570         struct cmbdata data;
 571         int ret;
 572
 573         ret = cmf_readall(block->base->cdev, &data);
 574         if (!ret && copy_to_user(argp, &data, min(size, sizeof(*argp))))
 575                 return -EFAULT;
 576         return ret;
 577 }
 578
 579 int dasd_ioctl(struct block_device *bdev, fmode_t mode,
 580                unsigned int cmd, unsigned long arg)
 581 {
 582         struct dasd_block *block;
 583         struct dasd_device *base;
 584         void __user *argp;
 585         int rc;
 586
 587         if (is_compat_task())
 588                 argp = compat_ptr(arg);
 589         else
 590                 argp = (void __user *)arg;
 591
 592         if ((_IOC_DIR(cmd) != _IOC_NONE) && !arg) {
 593                 PRINT_DEBUG("empty data ptr");
 594                 return -EINVAL;
 595         }
 596
 597         base = dasd_device_from_gendisk(bdev->bd_disk);
 598         if (!base)
 599                 return -ENODEV;
 600         block = base->block;
 601         rc = 0;
 602         switch (cmd) {
 603         case BIODASDDISABLE:
 604                 rc = dasd_ioctl_disable(bdev);
 605                 break;
 606         case BIODASDENABLE:
 607                 rc = dasd_ioctl_enable(bdev);
 608                 break;
 609         case BIODASDQUIESCE:
 610                 rc = dasd_ioctl_quiesce(block);
 611                 break;
 612         case BIODASDRESUME:
 613                 rc = dasd_ioctl_resume(block);
 614                 break;
 615         case BIODASDABORTIO:
 616                 rc = dasd_ioctl_abortio(block);
 617                 break;
 618         case BIODASDALLOWIO:
 619                 rc = dasd_ioctl_allowio(block);
 620                 break;
 621         case BIODASDFMT:
 622                 rc = dasd_ioctl_format(bdev, argp);
 623                 break;
 624         case BIODASDCHECKFMT:
 625                 rc = dasd_ioctl_check_format(bdev, argp);
 626                 break;
 627         case BIODASDINFO:
 628                 rc = dasd_ioctl_information(block, argp,
 629                                 sizeof(struct dasd_information_t));
 630                 break;
 631         case BIODASDINFO2:
 632                 rc = dasd_ioctl_information(block, argp,
 633                                 sizeof(struct dasd_information2_t));
 634                 break;
 635         case BIODASDPRRD:
 636                 rc = dasd_ioctl_read_profile(block, argp);
 637                 break;
 638         case BIODASDPRRST:
 639                 rc = dasd_ioctl_reset_profile(block);
 640                 break;
 641         case BLKROSET:
 642                 rc = dasd_ioctl_set_ro(bdev, argp);
 643                 break;
 644         case DASDAPIVER:
 645                 rc = dasd_ioctl_api_version(argp);
 646                 break;
 647         case BIODASDCMFENABLE:
 648                 rc = enable_cmf(base->cdev);
 649                 break;
 650         case BIODASDCMFDISABLE:
 651                 rc = disable_cmf(base->cdev);
 652                 break;
 653         case BIODASDREADALLCMB:
 654                 rc = dasd_ioctl_readall_cmb(block, cmd, argp);
 655                 break;
 656         case BIODASDRAS:
 657                 rc = dasd_ioctl_release_space(bdev, argp);
 658                 break;
 659         default:
 660                 /* if the discipline has an ioctl method try it. */
 661                 rc = -ENOTTY;
 662                 if (base->discipline->ioctl)
 663                         rc = base->discipline->ioctl(block, cmd, argp);
 664         }
 665         dasd_put_device(base);
 666         return rc;
 667 }
 668
 669
 670 /**
 671  * dasd_biodasdinfo() - fill out the dasd information structure
 672  * @disk [in]: pointer to gendisk structure that references a DASD
 673  * @info [out]: pointer to the dasd_information2_t structure
 674  *
 675  * Provide access to DASD specific information.
 676  * The gendisk structure is checked if it belongs to the DASD driver by
 677  * comparing the gendisk->fops pointer.
 678  * If it does not belong to the DASD driver -EINVAL is returned.
 679  * Otherwise the provided dasd_information2_t structure is filled out.
 680  *
 681  * Returns:
 682  *   %0 on success and a negative error value on failure.
 683  */
 684 int dasd_biodasdinfo(struct gendisk *disk, struct dasd_information2_t *info)
 685 {
 686         struct dasd_device *base;
 687         int error;
 688
 689         if (disk->fops != &dasd_device_operations)
 690                 return -EINVAL;
 691
 692         base = dasd_device_from_gendisk(disk);
 693         if (!base)
 694                 return -ENODEV;
 695         error = __dasd_ioctl_information(base->block, info);
 696         dasd_put_device(base);
 697         return error;
 698 }
 699 /* export that symbol_get in partition detection is possible */
 700 EXPORT_SYMBOL_GPL(dasd_biodasdinfo);