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         dasd_put_device(base);
  58         return 0;
  59 }
  60
  61 /*
  62  * Disable device.
  63  * Used by dasdfmt. Disable I/O operations but allow ioctls.
  64  */
  65 static int
  66 dasd_ioctl_disable(struct block_device *bdev)
  67 {
  68         struct dasd_device *base;
  69
  70         if (!capable(CAP_SYS_ADMIN))
  71                 return -EACCES;
  72
  73         base = dasd_device_from_gendisk(bdev->bd_disk);
  74         if (!base)
  75                 return -ENODEV;
  76         /*
  77          * Man this is sick. We don't do a real disable but only downgrade
  78          * the device to DASD_STATE_BASIC. The reason is that dasdfmt uses
  79          * BIODASDDISABLE to disable accesses to the device via the block
  80          * device layer but it still wants to do i/o on the device by
  81          * using the BIODASDFMT ioctl. Therefore the correct state for the
  82          * device is DASD_STATE_BASIC that allows to do basic i/o.
  83          */
  84         dasd_set_target_state(base, DASD_STATE_BASIC);
  85         /*
  86          * Set i_size to zero, since read, write, etc. check against this
  87          * value.
  88          */
  89         set_capacity(bdev->bd_disk, 0);
  90         dasd_put_device(base);
  91         return 0;
  92 }
  93
  94 /*
  95  * Quiesce device.
  96  */
  97 static int dasd_ioctl_quiesce(struct dasd_block *block)
  98 {
  99         unsigned long flags;
 100         struct dasd_device *base;
 101
 102         base = block->base;
 103         if (!capable (CAP_SYS_ADMIN))
 104                 return -EACCES;
 105
 106         pr_info("%s: The DASD has been put in the quiesce "
 107                 "state\n", dev_name(&base->cdev->dev));
 108         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
 109         dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
 110         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
 111         return 0;
 112 }
 113
 114
 115 /*
 116  * Resume device.
 117  */
 118 static int dasd_ioctl_resume(struct dasd_block *block)
 119 {
 120         unsigned long flags;
 121         struct dasd_device *base;
 122
 123         base = block->base;
 124         if (!capable (CAP_SYS_ADMIN))
 125                 return -EACCES;
 126
 127         pr_info("%s: I/O operations have been resumed "
 128                 "on the DASD\n", dev_name(&base->cdev->dev));
 129         spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
 130         dasd_device_remove_stop_bits(base, DASD_STOPPED_QUIESCE);
 131         spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
 132
 133         dasd_schedule_block_bh(block);
 134         return 0;
 135 }
 136
 137 /*
 138  * Abort all failfast I/O on a device.
 139  */
 140 static int dasd_ioctl_abortio(struct dasd_block *block)
 141 {
 142         unsigned long flags;
 143         struct dasd_device *base;
 144         struct dasd_ccw_req *cqr, *n;
 145
 146         base = block->base;
 147         if (!capable(CAP_SYS_ADMIN))
 148                 return -EACCES;
 149
 150         if (test_and_set_bit(DASD_FLAG_ABORTALL, &base->flags))
 151                 return 0;
 152         DBF_DEV_EVENT(DBF_NOTICE, base, "%s", "abortall flag set");
 153
 154         spin_lock_irqsave(&block->request_queue_lock, flags);
 155         spin_lock(&block->queue_lock);
 156         list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
 157                 if (test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
 158                     cqr->callback_data &&
 159                     cqr->callback_data != DASD_SLEEPON_START_TAG &&
 160                     cqr->callback_data != DASD_SLEEPON_END_TAG) {
 161                         spin_unlock(&block->queue_lock);
 162                         blk_abort_request(cqr->callback_data);
 163                         spin_lock(&block->queue_lock);
 164                 }
 165         }
 166         spin_unlock(&block->queue_lock);
 167         spin_unlock_irqrestore(&block->request_queue_lock, flags);
 168
 169         dasd_schedule_block_bh(block);
 170         return 0;
 171 }
 172
 173 /*
 174  * Allow I/O on a device
 175  */
 176 static int dasd_ioctl_allowio(struct dasd_block *block)
 177 {
 178         struct dasd_device *base;
 179
 180         base = block->base;
 181         if (!capable(CAP_SYS_ADMIN))
 182                 return -EACCES;
 183
 184         if (test_and_clear_bit(DASD_FLAG_ABORTALL, &base->flags))
 185                 DBF_DEV_EVENT(DBF_NOTICE, base, "%s", "abortall flag unset");
 186
 187         return 0;
 188 }
 189
 190 /*
 191  * performs formatting of _device_ according to _fdata_
 192  * Note: The discipline's format_function is assumed to deliver formatting
 193  * commands to format multiple units of the device. In terms of the ECKD
 194  * devices this means CCWs are generated to format multiple tracks.
 195  */
 196 static int
 197 dasd_format(struct dasd_block *block, struct format_data_t *fdata)
 198 {
 199         struct dasd_device *base;
 200         int rc;
 201
 202         base = block->base;
 203         if (base->discipline->format_device == NULL)
 204                 return -EPERM;
 205
 206         if (base->state != DASD_STATE_BASIC) {
 207                 pr_warn("%s: The DASD cannot be formatted while it is enabled\n",
 208                         dev_name(&base->cdev->dev));
 209                 return -EBUSY;
 210         }
 211
 212         DBF_DEV_EVENT(DBF_NOTICE, base,
 213                       "formatting units %u to %u (%u B blocks) flags %u",
 214                       fdata->start_unit,
 215                       fdata->stop_unit, fdata->blksize, fdata->intensity);
 216
 217         /* Since dasdfmt keeps the device open after it was disabled,
 218          * there still exists an inode for this device.
 219          * We must update i_blkbits, otherwise we might get errors when
 220          * enabling the device later.
 221          */
 222         if (fdata->start_unit == 0) {
 223                 block->gdp->part0->bd_inode->i_blkbits =
 224                         blksize_bits(fdata->blksize);
 225         }
 226
 227         rc = base->discipline->format_device(base, fdata, 1);
 228         if (rc == -EAGAIN)
 229                 rc = base->discipline->format_device(base, fdata, 0);
 230
 231         return rc;
 232 }
 233
 234 static int dasd_check_format(struct dasd_block *block,
 235                              struct format_check_t *cdata)
 236 {
 237         struct dasd_device *base;
 238         int rc;
 239
 240         base = block->base;
 241         if (!base->discipline->check_device_format)
 242                 return -ENOTTY;
 243
 244         rc = base->discipline->check_device_format(base, cdata, 1);
 245         if (rc == -EAGAIN)
 246                 rc = base->discipline->check_device_format(base, cdata, 0);
 247
 248         return rc;
 249 }
 250
 251 /*
 252  * Format device.
 253  */
 254 static int
 255 dasd_ioctl_format(struct block_device *bdev, void __user *argp)
 256 {
 257         struct dasd_device *base;
 258         struct format_data_t fdata;
 259         int rc;
 260
 261         if (!capable(CAP_SYS_ADMIN))
 262                 return -EACCES;
 263         if (!argp)
 264                 return -EINVAL;
 265         base = dasd_device_from_gendisk(bdev->bd_disk);
 266         if (!base)
 267                 return -ENODEV;
 268         if (base->features & DASD_FEATURE_READONLY ||
 269             test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
 270                 dasd_put_device(base);
 271                 return -EROFS;
 272         }
 273         if (copy_from_user(&fdata, argp, sizeof(struct format_data_t))) {
 274                 dasd_put_device(base);
 275                 return -EFAULT;
 276         }
 277         if (bdev_is_partition(bdev)) {
 278                 pr_warn("%s: The specified DASD is a partition and cannot be formatted\n",
 279                         dev_name(&base->cdev->dev));
 280                 dasd_put_device(base);
 281                 return -EINVAL;
 282         }
 283         rc = dasd_format(base->block, &fdata);
 284         dasd_put_device(base);
 285
 286         return rc;
 287 }
 288
 289 /*
 290  * Check device format
 291  */
 292 static int dasd_ioctl_check_format(struct block_device *bdev, void __user *argp)
 293 {
 294         struct format_check_t cdata;
 295         struct dasd_device *base;
 296         int rc = 0;
 297
 298         if (!argp)
 299                 return -EINVAL;
 300
 301         base = dasd_device_from_gendisk(bdev->bd_disk);
 302         if (!base)
 303                 return -ENODEV;
 304         if (bdev_is_partition(bdev)) {
 305                 pr_warn("%s: The specified DASD is a partition and cannot be checked\n",
 306                         dev_name(&base->cdev->dev));
 307                 rc = -EINVAL;
 308                 goto out_err;
 309         }
 310
 311         if (copy_from_user(&cdata, argp, sizeof(cdata))) {
 312                 rc = -EFAULT;
 313                 goto out_err;
 314         }
 315
 316         rc = dasd_check_format(base->block, &cdata);
 317         if (rc)
 318                 goto out_err;
 319
 320         if (copy_to_user(argp, &cdata, sizeof(cdata)))
 321                 rc = -EFAULT;
 322
 323 out_err:
 324         dasd_put_device(base);
 325
 326         return rc;
 327 }
 328
 329 static int dasd_release_space(struct dasd_device *device,
 330                               struct format_data_t *rdata)
 331 {
 332         if (!device->discipline->is_ese && !device->discipline->is_ese(device))
 333                 return -ENOTSUPP;
 334         if (!device->discipline->release_space)
 335                 return -ENOTSUPP;
 336
 337         return device->discipline->release_space(device, rdata);
 338 }
 339
 340 /*
 341  * Release allocated space
 342  */
 343 static int dasd_ioctl_release_space(struct block_device *bdev, void __user *argp)
 344 {
 345         struct format_data_t rdata;
 346         struct dasd_device *base;
 347         int rc = 0;
 348
 349         if (!capable(CAP_SYS_ADMIN))
 350                 return -EACCES;
 351         if (!argp)
 352                 return -EINVAL;
 353
 354         base = dasd_device_from_gendisk(bdev->bd_disk);
 355         if (!base)
 356                 return -ENODEV;
 357         if (base->features & DASD_FEATURE_READONLY ||
 358             test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
 359                 rc = -EROFS;
 360                 goto out_err;
 361         }
 362         if (bdev_is_partition(bdev)) {
 363                 pr_warn("%s: The specified DASD is a partition and tracks cannot be released\n",
 364                         dev_name(&base->cdev->dev));
 365                 rc = -EINVAL;
 366                 goto out_err;
 367         }
 368
 369         if (copy_from_user(&rdata, argp, sizeof(rdata))) {
 370                 rc = -EFAULT;
 371                 goto out_err;
 372         }
 373
 374         rc = dasd_release_space(base, &rdata);
 375
 376 out_err:
 377         dasd_put_device(base);
 378
 379         return rc;
 380 }
 381
 382 /*
 383  * Swap driver iternal copy relation.
 384  */
 385 static int
 386 dasd_ioctl_copy_pair_swap(struct block_device *bdev, void __user *argp)
 387 {
 388         struct dasd_copypair_swap_data_t data;
 389         struct dasd_device *device;
 390         int rc;
 391
 392         if (!capable(CAP_SYS_ADMIN))
 393                 return -EACCES;
 394
 395         device = dasd_device_from_gendisk(bdev->bd_disk);
 396         if (!device)
 397                 return -ENODEV;
 398
 399         if (copy_from_user(&data, argp, sizeof(struct dasd_copypair_swap_data_t))) {
 400                 dasd_put_device(device);
 401                 return -EFAULT;
 402         }
 403         if (memchr_inv(data.reserved, 0, sizeof(data.reserved))) {
 404                 pr_warn("%s: Invalid swap data specified\n",
 405                         dev_name(&device->cdev->dev));
 406                 dasd_put_device(device);
 407                 return DASD_COPYPAIRSWAP_INVALID;
 408         }
 409         if (bdev_is_partition(bdev)) {
 410                 pr_warn("%s: The specified DASD is a partition and cannot be swapped\n",
 411                         dev_name(&device->cdev->dev));
 412                 dasd_put_device(device);
 413                 return DASD_COPYPAIRSWAP_INVALID;
 414         }
 415         if (!device->copy) {
 416                 pr_warn("%s: The specified DASD has no copy pair set up\n",
 417                         dev_name(&device->cdev->dev));
 418                 dasd_put_device(device);
 419                 return -ENODEV;
 420         }
 421         if (!device->discipline->copy_pair_swap) {
 422                 dasd_put_device(device);
 423                 return -EOPNOTSUPP;
 424         }
 425         rc = device->discipline->copy_pair_swap(device, data.primary,
 426                                                 data.secondary);
 427         dasd_put_device(device);
 428
 429         return rc;
 430 }
 431
 432 #ifdef CONFIG_DASD_PROFILE
 433 /*
 434  * Reset device profile information
 435  */
 436 static int dasd_ioctl_reset_profile(struct dasd_block *block)
 437 {
 438         dasd_profile_reset(&block->profile);
 439         return 0;
 440 }
 441
 442 /*
 443  * Return device profile information
 444  */
 445 static int dasd_ioctl_read_profile(struct dasd_block *block, void __user *argp)
 446 {
 447         struct dasd_profile_info_t *data;
 448         int rc = 0;
 449
 450         data = kmalloc(sizeof(*data), GFP_KERNEL);
 451         if (!data)
 452                 return -ENOMEM;
 453
 454         spin_lock_bh(&block->profile.lock);
 455         if (block->profile.data) {
 456                 data->dasd_io_reqs = block->profile.data->dasd_io_reqs;
 457                 data->dasd_io_sects = block->profile.data->dasd_io_sects;
 458                 memcpy(data->dasd_io_secs, block->profile.data->dasd_io_secs,
 459                        sizeof(data->dasd_io_secs));
 460                 memcpy(data->dasd_io_times, block->profile.data->dasd_io_times,
 461                        sizeof(data->dasd_io_times));
 462                 memcpy(data->dasd_io_timps, block->profile.data->dasd_io_timps,
 463                        sizeof(data->dasd_io_timps));
 464                 memcpy(data->dasd_io_time1, block->profile.data->dasd_io_time1,
 465                        sizeof(data->dasd_io_time1));
 466                 memcpy(data->dasd_io_time2, block->profile.data->dasd_io_time2,
 467                        sizeof(data->dasd_io_time2));
 468                 memcpy(data->dasd_io_time2ps,
 469                        block->profile.data->dasd_io_time2ps,
 470                        sizeof(data->dasd_io_time2ps));
 471                 memcpy(data->dasd_io_time3, block->profile.data->dasd_io_time3,
 472                        sizeof(data->dasd_io_time3));
 473                 memcpy(data->dasd_io_nr_req,
 474                        block->profile.data->dasd_io_nr_req,
 475                        sizeof(data->dasd_io_nr_req));
 476                 spin_unlock_bh(&block->profile.lock);
 477         } else {
 478                 spin_unlock_bh(&block->profile.lock);
 479                 rc = -EIO;
 480                 goto out;
 481         }
 482         if (copy_to_user(argp, data, sizeof(*data)))
 483                 rc = -EFAULT;
 484 out:
 485         kfree(data);
 486         return rc;
 487 }
 488 #else
 489 static int dasd_ioctl_reset_profile(struct dasd_block *block)
 490 {
 491         return -ENOTTY;
 492 }
 493
 494 static int dasd_ioctl_read_profile(struct dasd_block *block, void __user *argp)
 495 {
 496         return -ENOTTY;
 497 }
 498 #endif
 499
 500 /*
 501  * Return dasd information. Used for BIODASDINFO and BIODASDINFO2.
 502  */
 503 static int __dasd_ioctl_information(struct dasd_block *block,
 504                 struct dasd_information2_t *dasd_info)
 505 {
 506         struct subchannel_id sch_id;
 507         struct ccw_dev_id dev_id;
 508         struct dasd_device *base;
 509         struct ccw_device *cdev;
 510         struct list_head *l;
 511         unsigned long flags;
 512         int rc;
 513
 514         base = block->base;
 515         if (!base->discipline || !base->discipline->fill_info)
 516                 return -EINVAL;
 517
 518         rc = base->discipline->fill_info(base, dasd_info);
 519         if (rc)
 520                 return rc;
 521
 522         cdev = base->cdev;
 523         ccw_device_get_id(cdev, &dev_id);
 524         ccw_device_get_schid(cdev, &sch_id);
 525
 526         dasd_info->devno = dev_id.devno;
 527         dasd_info->schid = sch_id.sch_no;
 528         dasd_info->cu_type = cdev->id.cu_type;
 529         dasd_info->cu_model = cdev->id.cu_model;
 530         dasd_info->dev_type = cdev->id.dev_type;
 531         dasd_info->dev_model = cdev->id.dev_model;
 532         dasd_info->status = base->state;
 533         /*
 534          * The open_count is increased for every opener, that includes
 535          * the blkdev_get in dasd_scan_partitions.
 536          * This must be hidden from user-space.
 537          */
 538         dasd_info->open_count = atomic_read(&block->open_count);
 539         if (!block->bdev)
 540                 dasd_info->open_count++;
 541
 542         /*
 543          * check if device is really formatted
 544          * LDL / CDL was returned by 'fill_info'
 545          */
 546         if ((base->state < DASD_STATE_READY) ||
 547             (dasd_check_blocksize(block->bp_block)))
 548                 dasd_info->format = DASD_FORMAT_NONE;
 549
 550         dasd_info->features |=
 551                 ((base->features & DASD_FEATURE_READONLY) != 0);
 552
 553         memcpy(dasd_info->type, base->discipline->name, 4);
 554
 555         spin_lock_irqsave(&block->queue_lock, flags);
 556         list_for_each(l, &base->ccw_queue)
 557                 dasd_info->chanq_len++;
 558         spin_unlock_irqrestore(&block->queue_lock, flags);
 559         return 0;
 560 }
 561
 562 static int dasd_ioctl_information(struct dasd_block *block, void __user *argp,
 563                 size_t copy_size)
 564 {
 565         struct dasd_information2_t *dasd_info;
 566         int error;
 567
 568         dasd_info = kzalloc(sizeof(*dasd_info), GFP_KERNEL);
 569         if (!dasd_info)
 570                 return -ENOMEM;
 571
 572         error = __dasd_ioctl_information(block, dasd_info);
 573         if (!error && copy_to_user(argp, dasd_info, copy_size))
 574                 error = -EFAULT;
 575         kfree(dasd_info);
 576         return error;
 577 }
 578
 579 /*
 580  * Set read only
 581  */
 582 int dasd_set_read_only(struct block_device *bdev, bool ro)
 583 {
 584         struct dasd_device *base;
 585         int rc;
 586
 587         /* do not manipulate hardware state for partitions */
 588         if (bdev_is_partition(bdev))
 589                 return 0;
 590
 591         base = dasd_device_from_gendisk(bdev->bd_disk);
 592         if (!base)
 593                 return -ENODEV;
 594         if (!ro && test_bit(DASD_FLAG_DEVICE_RO, &base->flags))
 595                 rc = -EROFS;
 596         else
 597                 rc = dasd_set_feature(base->cdev, DASD_FEATURE_READONLY, ro);
 598         dasd_put_device(base);
 599         return rc;
 600 }
 601
 602 static int dasd_ioctl_readall_cmb(struct dasd_block *block, unsigned int cmd,
 603                                   struct cmbdata __user *argp)
 604 {
 605         size_t size = _IOC_SIZE(cmd);
 606         struct cmbdata data;
 607         int ret;
 608
 609         ret = cmf_readall(block->base->cdev, &data);
 610         if (!ret && copy_to_user(argp, &data, min(size, sizeof(*argp))))
 611                 return -EFAULT;
 612         return ret;
 613 }
 614
 615 int dasd_ioctl(struct block_device *bdev, fmode_t mode,
 616                unsigned int cmd, unsigned long arg)
 617 {
 618         struct dasd_block *block;
 619         struct dasd_device *base;
 620         void __user *argp;
 621         int rc;
 622
 623         if (is_compat_task())
 624                 argp = compat_ptr(arg);
 625         else
 626                 argp = (void __user *)arg;
 627
 628         if ((_IOC_DIR(cmd) != _IOC_NONE) && !arg)
 629                 return -EINVAL;
 630
 631         base = dasd_device_from_gendisk(bdev->bd_disk);
 632         if (!base)
 633                 return -ENODEV;
 634         block = base->block;
 635         rc = 0;
 636         switch (cmd) {
 637         case BIODASDDISABLE:
 638                 rc = dasd_ioctl_disable(bdev);
 639                 break;
 640         case BIODASDENABLE:
 641                 rc = dasd_ioctl_enable(bdev);
 642                 break;
 643         case BIODASDQUIESCE:
 644                 rc = dasd_ioctl_quiesce(block);
 645                 break;
 646         case BIODASDRESUME:
 647                 rc = dasd_ioctl_resume(block);
 648                 break;
 649         case BIODASDABORTIO:
 650                 rc = dasd_ioctl_abortio(block);
 651                 break;
 652         case BIODASDALLOWIO:
 653                 rc = dasd_ioctl_allowio(block);
 654                 break;
 655         case BIODASDFMT:
 656                 rc = dasd_ioctl_format(bdev, argp);
 657                 break;
 658         case BIODASDCHECKFMT:
 659                 rc = dasd_ioctl_check_format(bdev, argp);
 660                 break;
 661         case BIODASDINFO:
 662                 rc = dasd_ioctl_information(block, argp,
 663                                 sizeof(struct dasd_information_t));
 664                 break;
 665         case BIODASDINFO2:
 666                 rc = dasd_ioctl_information(block, argp,
 667                                 sizeof(struct dasd_information2_t));
 668                 break;
 669         case BIODASDPRRD:
 670                 rc = dasd_ioctl_read_profile(block, argp);
 671                 break;
 672         case BIODASDPRRST:
 673                 rc = dasd_ioctl_reset_profile(block);
 674                 break;
 675         case DASDAPIVER:
 676                 rc = dasd_ioctl_api_version(argp);
 677                 break;
 678         case BIODASDCMFENABLE:
 679                 rc = enable_cmf(base->cdev);
 680                 break;
 681         case BIODASDCMFDISABLE:
 682                 rc = disable_cmf(base->cdev);
 683                 break;
 684         case BIODASDREADALLCMB:
 685                 rc = dasd_ioctl_readall_cmb(block, cmd, argp);
 686                 break;
 687         case BIODASDRAS:
 688                 rc = dasd_ioctl_release_space(bdev, argp);
 689                 break;
 690         case BIODASDCOPYPAIRSWAP:
 691                 rc = dasd_ioctl_copy_pair_swap(bdev, argp);
 692                 break;
 693         default:
 694                 /* if the discipline has an ioctl method try it. */
 695                 rc = -ENOTTY;
 696                 if (base->discipline->ioctl)
 697                         rc = base->discipline->ioctl(block, cmd, argp);
 698         }
 699         dasd_put_device(base);
 700         return rc;
 701 }
 702
 703
 704 /**
 705  * dasd_biodasdinfo() - fill out the dasd information structure
 706  * @disk: [in] pointer to gendisk structure that references a DASD
 707  * @info: [out] pointer to the dasd_information2_t structure
 708  *
 709  * Provide access to DASD specific information.
 710  * The gendisk structure is checked if it belongs to the DASD driver by
 711  * comparing the gendisk->fops pointer.
 712  * If it does not belong to the DASD driver -EINVAL is returned.
 713  * Otherwise the provided dasd_information2_t structure is filled out.
 714  *
 715  * Returns:
 716  *   %0 on success and a negative error value on failure.
 717  */
 718 int dasd_biodasdinfo(struct gendisk *disk, struct dasd_information2_t *info)
 719 {
 720         struct dasd_device *base;
 721         int error;
 722
 723         if (disk->fops != &dasd_device_operations)
 724                 return -EINVAL;
 725
 726         base = dasd_device_from_gendisk(disk);
 727         if (!base)
 728                 return -ENODEV;
 729         error = __dasd_ioctl_information(base->block, info);
 730         dasd_put_device(base);
 731         return error;
 732 }
 733 /* export that symbol_get in partition detection is possible */
 734 EXPORT_SYMBOL_GPL(dasd_biodasdinfo);