drivers/s390/block/dasd_ioctl.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
   4  *                  Horst Hummel <Horst.Hummel@de.ibm.com>
   5  *                  Carsten Otte <Cotte@de.ibm.com>
   6  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  * Bugreports.to..: <Linux390@de.ibm.com>
   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         bd_set_nr_sectors(bdev, get_capacity(base->block->gdp));
  59         dasd_put_device(base);
  60         return 0;
  61 }
  62
  63 /*
  64  * Disable device.
  65  * Used by dasdfmt. Disable I/O operations but allow ioctls.
  66  */
  67 static int
  68 dasd_ioctl_disable(struct block_device *bdev)
  69 {
  70         struct dasd_device *base;
  71
  72         if (!capable(CAP_SYS_ADMIN))
  73                 return -EACCES;
  74
  75         base = dasd_device_from_gendisk(bdev->bd_disk);
  76         if (!base)
  77                 return -ENODEV;
  78         /*
  79          * Man this is sick. We don't do a real disable but only downgrade
  80          * the device to DASD_STATE_BASIC. The reason is that dasdfmt uses
  81          * BIODASDDISABLE to disable accesses to the device via the block
  82          * device layer but it still wants to do i/o on the device by
  83          * using the BIODASDFMT ioctl. Therefore the correct state for the
  84          * device is DASD_STATE_BASIC that allows to do basic i/o.
  85          */
  86         dasd_set_target_state(base, DASD_STATE_BASIC);
  87         /*
  88          * Set i_size to zero, since read, write, etc. check against this
  89          * value.
  90          */
  91         bd_set_nr_sectors(bdev, 0);
  92         dasd_put_device(base);
  93         return 0;
  94 }
  95
  96 /*
  97  * Quiesce device.
  98  */
  99 static int dasd_ioctl_quiesce(struct dasd_block *block)
 100 {
 101         unsigned long flags;
 102         struct dasd_device *base;
 103
 104         base = block->base;
 105         if (!capable (CAP_SYS_ADMIN))
 106                 return -EACCES;
 107
 108         pr_info("%s: The DASD has been put in the quiesce "
 109                 "state\n", dev_name(&base->cdev->dev));
 110         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
 111         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
 112         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
 113         return 0;
 114 }
 115
 116
 117 /*
 118  * Resume device.
 119  */
 120 static int dasd_ioctl_resume(struct dasd_block *block)
 121 {
 122         unsigned long flags;
 123         struct dasd_device *base;
 124
 125         base = block->base;
 126         if (!capable (CAP_SYS_ADMIN))
 127                 return -EACCES;
 128
 129         pr_info("%s: I/O operations have been resumed "
 130                 "on the DASD\n", dev_name(&base->cdev->dev));
 131         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
 132         dasd_device_remove_stop_bits(base, DASD_STOPPED_QUIESCE);
 133         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
 134
 135         dasd_schedule_block_bh(block);
 136         dasd_schedule_device_bh(base);
 137         return 0;
 138 }
 139
 140 /*
 141  * Abort all failfast I/O on a device.
 142  */
 143 static int dasd_ioctl_abortio(struct dasd_block *block)
 144 {
 145         unsigned long flags;
 146         struct dasd_device *base;
 147         struct dasd_ccw_req *cqr, *n;
 148
 149         base = block->base;
 150         if (!capable(CAP_SYS_ADMIN))
 151                 return -EACCES;
 152
 153         if (test_and_set_bit(DASD_FLAG_ABORTALL, &base->flags))
 154                 return 0;
 155         DBF_DEV_EVENT(DBF_NOTICE, base, "%s", "abortall flag set");
 156
 157         spin_lock_irqsave(&block->request_queue_lock, flags);
 158         spin_lock(&block->queue_lock);
 159         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
 160                 if (test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
 161                     cqr->callback_data &&
 162                     cqr->callback_data != DASD_SLEEPON_START_TAG &&
 163                     cqr->callback_data != DASD_SLEEPON_END_TAG) {
 164                         spin_unlock(&block->queue_lock);
 165                         blk_abort_request(cqr->callback_data);
 166                         spin_lock(&block->queue_lock);
 167                 }
 168         }
 169         spin_unlock(&block->queue_lock);
 170         spin_unlock_irqrestore(&block->request_queue_lock, flags);
 171
 172         dasd_schedule_block_bh(block);
 173         return 0;
 174 }
 175
 176 /*
 177  * Allow I/O on a device
 178  */
 179 static int dasd_ioctl_allowio(struct dasd_block *block)
 180 {
 181         struct dasd_device *base;
 182
 183         base = block->base;
 184         if (!capable(CAP_SYS_ADMIN))
 185                 return -EACCES;
 186
 187         if (test_and_clear_bit(DASD_FLAG_ABORTALL, &base->flags))
 188                 DBF_DEV_EVENT(DBF_NOTICE, base, "%s", "abortall flag unset");
 189
 190         return 0;
 191 }
 192
 193 /*
 194  * performs formatting of _device_ according to _fdata_
 195  * Note: The discipline's format_function is assumed to deliver formatting
 196  * commands to format multiple units of the device. In terms of the ECKD
 197  * devices this means CCWs are generated to format multiple tracks.
 198  */
 199 static int
 200 dasd_format(struct dasd_block *block, struct format_data_t *fdata)
 201 {
 202         struct dasd_device *base;
 203         int rc;
 204
 205         base = block->base;
 206         if (base->discipline->format_device == NULL)
 207                 return -EPERM;
 208
 209         if (base->state != DASD_STATE_BASIC) {
 210                 pr_warn("%s: The DASD cannot be formatted while it is enabled\n",
 211                         dev_name(&base->cdev->dev));
 212                 return -EBUSY;
 213         }
 214
 215         DBF_DEV_EVENT(DBF_NOTICE, base,
 216                       "formatting units %u to %u (%u B blocks) flags %u",
 217                       fdata->start_unit,
 218                       fdata->stop_unit, fdata->blksize, fdata->intensity);
 219
 220         /* Since dasdfmt keeps the device open after it was disabled,
 221          * there still exists an inode for this device.
 222          * We must update i_blkbits, otherwise we might get errors when
 223          * enabling the device later.
 224          */
 225         if (fdata->start_unit == 0) {
 226                 struct block_device *bdev = bdget_disk(block->gdp, 0);
 227                 bdev->bd_inode->i_blkbits = blksize_bits(fdata->blksize);
 228                 bdput(bdev);
 229         }
 230
 231         rc = base->discipline->format_device(base, fdata, 1);
 232         if (rc == -EAGAIN)
 233                 rc = base->discipline->format_device(base, fdata, 0);
 234
 235         return rc;
 236 }
 237
 238 static int dasd_check_format(struct dasd_block *block,
 239                              struct format_check_t *cdata)
 240 {
 241         struct dasd_device *base;
 242         int rc;
 243
 244         base = block->base;
 245         if (!base->discipline->check_device_format)
 246                 return -ENOTTY;
 247
 248         rc = base->discipline->check_device_format(base, cdata, 1);
 249         if (rc == -EAGAIN)
 250                 rc = base->discipline->check_device_format(base, cdata, 0);
 251
 252         return rc;
 253 }
 254
 255 /*
 256  * Format device.
 257  */
 258 static int
 259 dasd_ioctl_format(struct block_device *bdev, void __user *argp)
 260 {
 261         struct dasd_device *base;
 262         struct format_data_t fdata;
 263         int rc;
 264
 265         if (!capable(CAP_SYS_ADMIN))
 266                 return -EACCES;
 267         if (!argp)
 268                 return -EINVAL;
 269         base = dasd_device_from_gendisk(bdev->bd_disk);
 270         if (!base)
 271                 return -ENODEV;
 272         if (base->features & DASD_FEATURE_READONLY ||
 273             test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
 274                 dasd_put_device(base);
 275                 return -EROFS;
 276         }
 277         if (copy_from_user(&fdata, argp, sizeof(struct format_data_t))) {
 278                 dasd_put_device(base);
 279                 return -EFAULT;
 280         }
 281         if (bdev_is_partition(bdev)) {
 282                 pr_warn("%s: The specified DASD is a partition and cannot be formatted\n",
 283                         dev_name(&base->cdev->dev));
 284                 dasd_put_device(base);
 285                 return -EINVAL;
 286         }
 287         rc = dasd_format(base->block, &fdata);
 288         dasd_put_device(base);
 289
 290         return rc;
 291 }
 292
 293 /*
 294  * Check device format
 295  */
 296 static int dasd_ioctl_check_format(struct block_device *bdev, void __user *argp)
 297 {
 298         struct format_check_t cdata;
 299         struct dasd_device *base;
 300         int rc = 0;
 301
 302         if (!argp)
 303                 return -EINVAL;
 304
 305         base = dasd_device_from_gendisk(bdev->bd_disk);
 306         if (!base)
 307                 return -ENODEV;
 308         if (bdev_is_partition(bdev)) {
 309                 pr_warn("%s: The specified DASD is a partition and cannot be checked\n",
 310                         dev_name(&base->cdev->dev));
 311                 rc = -EINVAL;
 312                 goto out_err;
 313         }
 314
 315         if (copy_from_user(&cdata, argp, sizeof(cdata))) {
 316                 rc = -EFAULT;
 317                 goto out_err;
 318         }
 319
 320         rc = dasd_check_format(base->block, &cdata);
 321         if (rc)
 322                 goto out_err;
 323
 324         if (copy_to_user(argp, &cdata, sizeof(cdata)))
 325                 rc = -EFAULT;
 326
 327 out_err:
 328         dasd_put_device(base);
 329
 330         return rc;
 331 }
 332
 333 static int dasd_release_space(struct dasd_device *device,
 334                               struct format_data_t *rdata)
 335 {
 336         if (!device->discipline->is_ese && !device->discipline->is_ese(device))
 337                 return -ENOTSUPP;
 338         if (!device->discipline->release_space)
 339                 return -ENOTSUPP;
 340
 341         return device->discipline->release_space(device, rdata);
 342 }
 343
 344 /*
 345  * Release allocated space
 346  */
 347 static int dasd_ioctl_release_space(struct block_device *bdev, void __user *argp)
 348 {
 349         struct format_data_t rdata;
 350         struct dasd_device *base;
 351         int rc = 0;
 352
 353         if (!capable(CAP_SYS_ADMIN))
 354                 return -EACCES;
 355         if (!argp)
 356                 return -EINVAL;
 357
 358         base = dasd_device_from_gendisk(bdev->bd_disk);
 359         if (!base)
 360                 return -ENODEV;
 361         if (base->features & DASD_FEATURE_READONLY ||
 362             test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
 363                 rc = -EROFS;
 364                 goto out_err;
 365         }
 366         if (bdev_is_partition(bdev)) {
 367                 pr_warn("%s: The specified DASD is a partition and tracks cannot be released\n",
 368                         dev_name(&base->cdev->dev));
 369                 rc = -EINVAL;
 370                 goto out_err;
 371         }
 372
 373         if (copy_from_user(&rdata, argp, sizeof(rdata))) {
 374                 rc = -EFAULT;
 375                 goto out_err;
 376         }
 377
 378         rc = dasd_release_space(base, &rdata);
 379
 380 out_err:
 381         dasd_put_device(base);
 382
 383         return rc;
 384 }
 385
 386 #ifdef CONFIG_DASD_PROFILE
 387 /*
 388  * Reset device profile information
 389  */
 390 static int dasd_ioctl_reset_profile(struct dasd_block *block)
 391 {
 392         dasd_profile_reset(&block->profile);
 393         return 0;
 394 }
 395
 396 /*
 397  * Return device profile information
 398  */
 399 static int dasd_ioctl_read_profile(struct dasd_block *block, void __user *argp)
 400 {
 401         struct dasd_profile_info_t *data;
 402         int rc = 0;
 403
 404         data = kmalloc(sizeof(*data), GFP_KERNEL);
 405         if (!data)
 406                 return -ENOMEM;
 407
 408         spin_lock_bh(&block->profile.lock);
 409         if (block->profile.data) {
 410                 data->dasd_io_reqs = block->profile.data->dasd_io_reqs;
 411                 data->dasd_io_sects = block->profile.data->dasd_io_sects;
 412                 memcpy(data->dasd_io_secs, block->profile.data->dasd_io_secs,
 413                        sizeof(data->dasd_io_secs));
 414                 memcpy(data->dasd_io_times, block->profile.data->dasd_io_times,
 415                        sizeof(data->dasd_io_times));
 416                 memcpy(data->dasd_io_timps, block->profile.data->dasd_io_timps,
 417                        sizeof(data->dasd_io_timps));
 418                 memcpy(data->dasd_io_time1, block->profile.data->dasd_io_time1,
 419                        sizeof(data->dasd_io_time1));
 420                 memcpy(data->dasd_io_time2, block->profile.data->dasd_io_time2,
 421                        sizeof(data->dasd_io_time2));
 422                 memcpy(data->dasd_io_time2ps,
 423                        block->profile.data->dasd_io_time2ps,
 424                        sizeof(data->dasd_io_time2ps));
 425                 memcpy(data->dasd_io_time3, block->profile.data->dasd_io_time3,
 426                        sizeof(data->dasd_io_time3));
 427                 memcpy(data->dasd_io_nr_req,
 428                        block->profile.data->dasd_io_nr_req,
 429                        sizeof(data->dasd_io_nr_req));
 430                 spin_unlock_bh(&block->profile.lock);
 431         } else {
 432                 spin_unlock_bh(&block->profile.lock);
 433                 rc = -EIO;
 434                 goto out;
 435         }
 436         if (copy_to_user(argp, data, sizeof(*data)))
 437                 rc = -EFAULT;
 438 out:
 439         kfree(data);
 440         return rc;
 441 }
 442 #else
 443 static int dasd_ioctl_reset_profile(struct dasd_block *block)
 444 {
 445         return -ENOTTY;
 446 }
 447
 448 static int dasd_ioctl_read_profile(struct dasd_block *block, void __user *argp)
 449 {
 450         return -ENOTTY;
 451 }
 452 #endif
 453
 454 /*
 455  * Return dasd information. Used for BIODASDINFO and BIODASDINFO2.
 456  */
 457 static int __dasd_ioctl_information(struct dasd_block *block,
 458                 struct dasd_information2_t *dasd_info)
 459 {
 460         struct subchannel_id sch_id;
 461         struct ccw_dev_id dev_id;
 462         struct dasd_device *base;
 463         struct ccw_device *cdev;
 464         struct list_head *l;
 465         unsigned long flags;
 466         int rc;
 467
 468         base = block->base;
 469         if (!base->discipline || !base->discipline->fill_info)
 470                 return -EINVAL;
 471
 472         rc = base->discipline->fill_info(base, dasd_info);
 473         if (rc)
 474                 return rc;
 475
 476         cdev = base->cdev;
 477         ccw_device_get_id(cdev, &dev_id);
 478         ccw_device_get_schid(cdev, &sch_id);
 479
 480         dasd_info->devno = dev_id.devno;
 481         dasd_info->schid = sch_id.sch_no;
 482         dasd_info->cu_type = cdev->id.cu_type;
 483         dasd_info->cu_model = cdev->id.cu_model;
 484         dasd_info->dev_type = cdev->id.dev_type;
 485         dasd_info->dev_model = cdev->id.dev_model;
 486         dasd_info->status = base->state;
 487         /*
 488          * The open_count is increased for every opener, that includes
 489          * the blkdev_get in dasd_scan_partitions.
 490          * This must be hidden from user-space.
 491          */
 492         dasd_info->open_count = atomic_read(&block->open_count);
 493         if (!block->bdev)
 494                 dasd_info->open_count++;
 495
 496         /*
 497          * check if device is really formatted
 498          * LDL / CDL was returned by 'fill_info'
 499          */
 500         if ((base->state < DASD_STATE_READY) ||
 501             (dasd_check_blocksize(block->bp_block)))
 502                 dasd_info->format = DASD_FORMAT_NONE;
 503
 504         dasd_info->features |=
 505                 ((base->features & DASD_FEATURE_READONLY) != 0);
 506
 507         memcpy(dasd_info->type, base->discipline->name, 4);
 508
 509         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
 510         list_for_each(l, &base->ccw_queue)
 511                 dasd_info->chanq_len++;
 512         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
 513         return 0;
 514 }
 515
 516 static int dasd_ioctl_information(struct dasd_block *block, void __user *argp,
 517                 size_t copy_size)
 518 {
 519         struct dasd_information2_t *dasd_info;
 520         int error;
 521
 522         dasd_info = kzalloc(sizeof(*dasd_info), GFP_KERNEL);
 523         if (!dasd_info)
 524                 return -ENOMEM;
 525
 526         error = __dasd_ioctl_information(block, dasd_info);
 527         if (!error && copy_to_user(argp, dasd_info, copy_size))
 528                 error = -EFAULT;
 529         kfree(dasd_info);
 530         return error;
 531 }
 532
 533 /*
 534  * Set read only
 535  */
 536 static int
 537 dasd_ioctl_set_ro(struct block_device *bdev, void __user *argp)
 538 {
 539         struct dasd_device *base;
 540         int intval, rc;
 541
 542         if (!capable(CAP_SYS_ADMIN))
 543                 return -EACCES;
 544         if (bdev_is_partition(bdev))
 545                 // ro setting is not allowed for partitions
 546                 return -EINVAL;
 547         if (get_user(intval, (int __user *)argp))
 548                 return -EFAULT;
 549         base = dasd_device_from_gendisk(bdev->bd_disk);
 550         if (!base)
 551                 return -ENODEV;
 552         if (!intval && test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
 553                 dasd_put_device(base);
 554                 return -EROFS;
 555         }
 556         set_disk_ro(bdev->bd_disk, intval);
 557         rc = dasd_set_feature(base->cdev, DASD_FEATURE_READONLY, intval);
 558         dasd_put_device(base);
 559         return rc;
 560 }
 561
 562 static int dasd_ioctl_readall_cmb(struct dasd_block *block, unsigned int cmd,
 563                                   struct cmbdata __user *argp)
 564 {
 565         size_t size = _IOC_SIZE(cmd);
 566         struct cmbdata data;
 567         int ret;
 568
 569         ret = cmf_readall(block->base->cdev, &data);
 570         if (!ret && copy_to_user(argp, &data, min(size, sizeof(*argp))))
 571                 return -EFAULT;
 572         return ret;
 573 }
 574
 575 int dasd_ioctl(struct block_device *bdev, fmode_t mode,
 576                unsigned int cmd, unsigned long arg)
 577 {
 578         struct dasd_block *block;
 579         struct dasd_device *base;
 580         void __user *argp;
 581         int rc;
 582
 583         if (is_compat_task())
 584                 argp = compat_ptr(arg);
 585         else
 586                 argp = (void __user *)arg;
 587
 588         if ((_IOC_DIR(cmd) != _IOC_NONE) && !arg) {
 589                 PRINT_DEBUG("empty data ptr");
 590                 return -EINVAL;
 591         }
 592
 593         base = dasd_device_from_gendisk(bdev->bd_disk);
 594         if (!base)
 595                 return -ENODEV;
 596         block = base->block;
 597         rc = 0;
 598         switch (cmd) {
 599         case BIODASDDISABLE:
 600                 rc = dasd_ioctl_disable(bdev);
 601                 break;
 602         case BIODASDENABLE:
 603                 rc = dasd_ioctl_enable(bdev);
 604                 break;
 605         case BIODASDQUIESCE:
 606                 rc = dasd_ioctl_quiesce(block);
 607                 break;
 608         case BIODASDRESUME:
 609                 rc = dasd_ioctl_resume(block);
 610                 break;
 611         case BIODASDABORTIO:
 612                 rc = dasd_ioctl_abortio(block);
 613                 break;
 614         case BIODASDALLOWIO:
 615                 rc = dasd_ioctl_allowio(block);
 616                 break;
 617         case BIODASDFMT:
 618                 rc = dasd_ioctl_format(bdev, argp);
 619                 break;
 620         case BIODASDCHECKFMT:
 621                 rc = dasd_ioctl_check_format(bdev, argp);
 622                 break;
 623         case BIODASDINFO:
 624                 rc = dasd_ioctl_information(block, argp,
 625                                 sizeof(struct dasd_information_t));
 626                 break;
 627         case BIODASDINFO2:
 628                 rc = dasd_ioctl_information(block, argp,
 629                                 sizeof(struct dasd_information2_t));
 630                 break;
 631         case BIODASDPRRD:
 632                 rc = dasd_ioctl_read_profile(block, argp);
 633                 break;
 634         case BIODASDPRRST:
 635                 rc = dasd_ioctl_reset_profile(block);
 636                 break;
 637         case BLKROSET:
 638                 rc = dasd_ioctl_set_ro(bdev, argp);
 639                 break;
 640         case DASDAPIVER:
 641                 rc = dasd_ioctl_api_version(argp);
 642                 break;
 643         case BIODASDCMFENABLE:
 644                 rc = enable_cmf(base->cdev);
 645                 break;
 646         case BIODASDCMFDISABLE:
 647                 rc = disable_cmf(base->cdev);
 648                 break;
 649         case BIODASDREADALLCMB:
 650                 rc = dasd_ioctl_readall_cmb(block, cmd, argp);
 651                 break;
 652         case BIODASDRAS:
 653                 rc = dasd_ioctl_release_space(bdev, argp);
 654                 break;
 655         default:
 656                 /* if the discipline has an ioctl method try it. */
 657                 rc = -ENOTTY;
 658                 if (base->discipline->ioctl)
 659                         rc = base->discipline->ioctl(block, cmd, argp);
 660         }
 661         dasd_put_device(base);
 662         return rc;
 663 }
 664
 665
 666 /**
 667  * dasd_biodasdinfo() - fill out the dasd information structure
 668  * @disk [in]: pointer to gendisk structure that references a DASD
 669  * @info [out]: pointer to the dasd_information2_t structure
 670  *
 671  * Provide access to DASD specific information.
 672  * The gendisk structure is checked if it belongs to the DASD driver by
 673  * comparing the gendisk->fops pointer.
 674  * If it does not belong to the DASD driver -EINVAL is returned.
 675  * Otherwise the provided dasd_information2_t structure is filled out.
 676  *
 677  * Returns:
 678  *   %0 on success and a negative error value on failure.
 679  */
 680 int dasd_biodasdinfo(struct gendisk *disk, struct dasd_information2_t *info)
 681 {
 682         struct dasd_device *base;
 683         int error;
 684
 685         if (disk->fops != &dasd_device_operations)
 686                 return -EINVAL;
 687
 688         base = dasd_device_from_gendisk(disk);
 689         if (!base)
 690                 return -ENODEV;
 691         error = __dasd_ioctl_information(base->block, info);
 692         dasd_put_device(base);
 693         return error;
 694 }
 695 /* export that symbol_get in partition detection is possible */
 696 EXPORT_SYMBOL_GPL(dasd_biodasdinfo);