block/ioctl.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/capability.h>
   3 #include <linux/compat.h>
   4 #include <linux/blkdev.h>
   5 #include <linux/export.h>
   6 #include <linux/gfp.h>
   7 #include <linux/blkpg.h>
   8 #include <linux/hdreg.h>
   9 #include <linux/backing-dev.h>
  10 #include <linux/fs.h>
  11 #include <linux/blktrace_api.h>
  12 #include <linux/pr.h>
  13 #include <linux/uaccess.h>
  14 #include "blk.h"
  15
  16 static int blkpg_do_ioctl(struct block_device *bdev,
  17                           struct blkpg_partition __user *upart, int op)
  18 {
  19         struct gendisk *disk = bdev->bd_disk;
  20         struct blkpg_partition p;
  21         sector_t start, length, capacity, end;
  22
  23         if (!capable(CAP_SYS_ADMIN))
  24                 return -EACCES;
  25         if (copy_from_user(&p, upart, sizeof(struct blkpg_partition)))
  26                 return -EFAULT;
  27         if (bdev_is_partition(bdev))
  28                 return -EINVAL;
  29
  30         if (p.pno <= 0)
  31                 return -EINVAL;
  32
  33         if (op == BLKPG_DEL_PARTITION)
  34                 return bdev_del_partition(disk, p.pno);
  35
  36         if (p.start < 0 || p.length <= 0 || p.start + p.length < 0)
  37                 return -EINVAL;
  38         /* Check that the partition is aligned to the block size */
  39         if (!IS_ALIGNED(p.start | p.length, bdev_logical_block_size(bdev)))
  40                 return -EINVAL;
  41
  42         start = p.start >> SECTOR_SHIFT;
  43         length = p.length >> SECTOR_SHIFT;
  44         capacity = get_capacity(disk);
  45
  46         if (check_add_overflow(start, length, &end))
  47                 return -EINVAL;
  48
  49         if (start >= capacity || end > capacity)
  50                 return -EINVAL;
  51
  52         switch (op) {
  53         case BLKPG_ADD_PARTITION:
  54                 return bdev_add_partition(disk, p.pno, start, length);
  55         case BLKPG_RESIZE_PARTITION:
  56                 return bdev_resize_partition(disk, p.pno, start, length);
  57         default:
  58                 return -EINVAL;
  59         }
  60 }
  61
  62 static int blkpg_ioctl(struct block_device *bdev,
  63                        struct blkpg_ioctl_arg __user *arg)
  64 {
  65         struct blkpg_partition __user *udata;
  66         int op;
  67
  68         if (get_user(op, &arg->op) || get_user(udata, &arg->data))
  69                 return -EFAULT;
  70
  71         return blkpg_do_ioctl(bdev, udata, op);
  72 }
  73
  74 #ifdef CONFIG_COMPAT
  75 struct compat_blkpg_ioctl_arg {
  76         compat_int_t op;
  77         compat_int_t flags;
  78         compat_int_t datalen;
  79         compat_caddr_t data;
  80 };
  81
  82 static int compat_blkpg_ioctl(struct block_device *bdev,
  83                               struct compat_blkpg_ioctl_arg __user *arg)
  84 {
  85         compat_caddr_t udata;
  86         int op;
  87
  88         if (get_user(op, &arg->op) || get_user(udata, &arg->data))
  89                 return -EFAULT;
  90
  91         return blkpg_do_ioctl(bdev, compat_ptr(udata), op);
  92 }
  93 #endif
  94
  95 static int blk_ioctl_discard(struct block_device *bdev, blk_mode_t mode,
  96                 unsigned long arg)
  97 {
  98         uint64_t range[2];
  99         uint64_t start, len, end;
 100         struct inode *inode = bdev->bd_inode;
 101         int err;
 102
 103         if (!(mode & BLK_OPEN_WRITE))
 104                 return -EBADF;
 105
 106         if (!bdev_max_discard_sectors(bdev))
 107                 return -EOPNOTSUPP;
 108
 109         if (copy_from_user(range, (void __user *)arg, sizeof(range)))
 110                 return -EFAULT;
 111
 112         start = range[0];
 113         len = range[1];
 114
 115         if (start & 511)
 116                 return -EINVAL;
 117         if (len & 511)
 118                 return -EINVAL;
 119
 120         if (check_add_overflow(start, len, &end) ||
 121             end > bdev_nr_bytes(bdev))
 122                 return -EINVAL;
 123
 124         filemap_invalidate_lock(inode->i_mapping);
 125         err = truncate_bdev_range(bdev, mode, start, start + len - 1);
 126         if (err)
 127                 goto fail;
 128         err = blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL);
 129 fail:
 130         filemap_invalidate_unlock(inode->i_mapping);
 131         return err;
 132 }
 133
 134 static int blk_ioctl_secure_erase(struct block_device *bdev, blk_mode_t mode,
 135                 void __user *argp)
 136 {
 137         uint64_t start, len;
 138         uint64_t range[2];
 139         int err;
 140
 141         if (!(mode & BLK_OPEN_WRITE))
 142                 return -EBADF;
 143         if (!bdev_max_secure_erase_sectors(bdev))
 144                 return -EOPNOTSUPP;
 145         if (copy_from_user(range, argp, sizeof(range)))
 146                 return -EFAULT;
 147
 148         start = range[0];
 149         len = range[1];
 150         if ((start & 511) || (len & 511))
 151                 return -EINVAL;
 152         if (start + len > bdev_nr_bytes(bdev))
 153                 return -EINVAL;
 154
 155         filemap_invalidate_lock(bdev->bd_inode->i_mapping);
 156         err = truncate_bdev_range(bdev, mode, start, start + len - 1);
 157         if (!err)
 158                 err = blkdev_issue_secure_erase(bdev, start >> 9, len >> 9,
 159                                                 GFP_KERNEL);
 160         filemap_invalidate_unlock(bdev->bd_inode->i_mapping);
 161         return err;
 162 }
 163
 164
 165 static int blk_ioctl_zeroout(struct block_device *bdev, blk_mode_t mode,
 166                 unsigned long arg)
 167 {
 168         uint64_t range[2];
 169         uint64_t start, end, len;
 170         struct inode *inode = bdev->bd_inode;
 171         int err;
 172
 173         if (!(mode & BLK_OPEN_WRITE))
 174                 return -EBADF;
 175
 176         if (copy_from_user(range, (void __user *)arg, sizeof(range)))
 177                 return -EFAULT;
 178
 179         start = range[0];
 180         len = range[1];
 181         end = start + len - 1;
 182
 183         if (start & 511)
 184                 return -EINVAL;
 185         if (len & 511)
 186                 return -EINVAL;
 187         if (end >= (uint64_t)bdev_nr_bytes(bdev))
 188                 return -EINVAL;
 189         if (end < start)
 190                 return -EINVAL;
 191
 192         /* Invalidate the page cache, including dirty pages */
 193         filemap_invalidate_lock(inode->i_mapping);
 194         err = truncate_bdev_range(bdev, mode, start, end);
 195         if (err)
 196                 goto fail;
 197
 198         err = blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL,
 199                                    BLKDEV_ZERO_NOUNMAP);
 200
 201 fail:
 202         filemap_invalidate_unlock(inode->i_mapping);
 203         return err;
 204 }
 205
 206 static int put_ushort(unsigned short __user *argp, unsigned short val)
 207 {
 208         return put_user(val, argp);
 209 }
 210
 211 static int put_int(int __user *argp, int val)
 212 {
 213         return put_user(val, argp);
 214 }
 215
 216 static int put_uint(unsigned int __user *argp, unsigned int val)
 217 {
 218         return put_user(val, argp);
 219 }
 220
 221 static int put_long(long __user *argp, long val)
 222 {
 223         return put_user(val, argp);
 224 }
 225
 226 static int put_ulong(unsigned long __user *argp, unsigned long val)
 227 {
 228         return put_user(val, argp);
 229 }
 230
 231 static int put_u64(u64 __user *argp, u64 val)
 232 {
 233         return put_user(val, argp);
 234 }
 235
 236 #ifdef CONFIG_COMPAT
 237 static int compat_put_long(compat_long_t __user *argp, long val)
 238 {
 239         return put_user(val, argp);
 240 }
 241
 242 static int compat_put_ulong(compat_ulong_t __user *argp, compat_ulong_t val)
 243 {
 244         return put_user(val, argp);
 245 }
 246 #endif
 247
 248 #ifdef CONFIG_COMPAT
 249 /*
 250  * This is the equivalent of compat_ptr_ioctl(), to be used by block
 251  * drivers that implement only commands that are completely compatible
 252  * between 32-bit and 64-bit user space
 253  */
 254 int blkdev_compat_ptr_ioctl(struct block_device *bdev, blk_mode_t mode,
 255                         unsigned cmd, unsigned long arg)
 256 {
 257         struct gendisk *disk = bdev->bd_disk;
 258
 259         if (disk->fops->ioctl)
 260                 return disk->fops->ioctl(bdev, mode, cmd,
 261                                          (unsigned long)compat_ptr(arg));
 262
 263         return -ENOIOCTLCMD;
 264 }
 265 EXPORT_SYMBOL(blkdev_compat_ptr_ioctl);
 266 #endif
 267
 268 static bool blkdev_pr_allowed(struct block_device *bdev, blk_mode_t mode)
 269 {
 270         /* no sense to make reservations for partitions */
 271         if (bdev_is_partition(bdev))
 272                 return false;
 273
 274         if (capable(CAP_SYS_ADMIN))
 275                 return true;
 276         /*
 277          * Only allow unprivileged reservations if the file descriptor is open
 278          * for writing.
 279          */
 280         return mode & BLK_OPEN_WRITE;
 281 }
 282
 283 static int blkdev_pr_register(struct block_device *bdev, blk_mode_t mode,
 284                 struct pr_registration __user *arg)
 285 {
 286         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
 287         struct pr_registration reg;
 288
 289         if (!blkdev_pr_allowed(bdev, mode))
 290                 return -EPERM;
 291         if (!ops || !ops->pr_register)
 292                 return -EOPNOTSUPP;
 293         if (copy_from_user(&reg, arg, sizeof(reg)))
 294                 return -EFAULT;
 295
 296         if (reg.flags & ~PR_FL_IGNORE_KEY)
 297                 return -EOPNOTSUPP;
 298         return ops->pr_register(bdev, reg.old_key, reg.new_key, reg.flags);
 299 }
 300
 301 static int blkdev_pr_reserve(struct block_device *bdev, blk_mode_t mode,
 302                 struct pr_reservation __user *arg)
 303 {
 304         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
 305         struct pr_reservation rsv;
 306
 307         if (!blkdev_pr_allowed(bdev, mode))
 308                 return -EPERM;
 309         if (!ops || !ops->pr_reserve)
 310                 return -EOPNOTSUPP;
 311         if (copy_from_user(&rsv, arg, sizeof(rsv)))
 312                 return -EFAULT;
 313
 314         if (rsv.flags & ~PR_FL_IGNORE_KEY)
 315                 return -EOPNOTSUPP;
 316         return ops->pr_reserve(bdev, rsv.key, rsv.type, rsv.flags);
 317 }
 318
 319 static int blkdev_pr_release(struct block_device *bdev, blk_mode_t mode,
 320                 struct pr_reservation __user *arg)
 321 {
 322         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
 323         struct pr_reservation rsv;
 324
 325         if (!blkdev_pr_allowed(bdev, mode))
 326                 return -EPERM;
 327         if (!ops || !ops->pr_release)
 328                 return -EOPNOTSUPP;
 329         if (copy_from_user(&rsv, arg, sizeof(rsv)))
 330                 return -EFAULT;
 331
 332         if (rsv.flags)
 333                 return -EOPNOTSUPP;
 334         return ops->pr_release(bdev, rsv.key, rsv.type);
 335 }
 336
 337 static int blkdev_pr_preempt(struct block_device *bdev, blk_mode_t mode,
 338                 struct pr_preempt __user *arg, bool abort)
 339 {
 340         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
 341         struct pr_preempt p;
 342
 343         if (!blkdev_pr_allowed(bdev, mode))
 344                 return -EPERM;
 345         if (!ops || !ops->pr_preempt)
 346                 return -EOPNOTSUPP;
 347         if (copy_from_user(&p, arg, sizeof(p)))
 348                 return -EFAULT;
 349
 350         if (p.flags)
 351                 return -EOPNOTSUPP;
 352         return ops->pr_preempt(bdev, p.old_key, p.new_key, p.type, abort);
 353 }
 354
 355 static int blkdev_pr_clear(struct block_device *bdev, blk_mode_t mode,
 356                 struct pr_clear __user *arg)
 357 {
 358         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
 359         struct pr_clear c;
 360
 361         if (!blkdev_pr_allowed(bdev, mode))
 362                 return -EPERM;
 363         if (!ops || !ops->pr_clear)
 364                 return -EOPNOTSUPP;
 365         if (copy_from_user(&c, arg, sizeof(c)))
 366                 return -EFAULT;
 367
 368         if (c.flags)
 369                 return -EOPNOTSUPP;
 370         return ops->pr_clear(bdev, c.key);
 371 }
 372
 373 static int blkdev_flushbuf(struct block_device *bdev, unsigned cmd,
 374                 unsigned long arg)
 375 {
 376         if (!capable(CAP_SYS_ADMIN))
 377                 return -EACCES;
 378
 379         mutex_lock(&bdev->bd_holder_lock);
 380         if (bdev->bd_holder_ops && bdev->bd_holder_ops->sync)
 381                 bdev->bd_holder_ops->sync(bdev);
 382         else {
 383                 mutex_unlock(&bdev->bd_holder_lock);
 384                 sync_blockdev(bdev);
 385         }
 386
 387         invalidate_bdev(bdev);
 388         return 0;
 389 }
 390
 391 static int blkdev_roset(struct block_device *bdev, unsigned cmd,
 392                 unsigned long arg)
 393 {
 394         int ret, n;
 395
 396         if (!capable(CAP_SYS_ADMIN))
 397                 return -EACCES;
 398
 399         if (get_user(n, (int __user *)arg))
 400                 return -EFAULT;
 401         if (bdev->bd_disk->fops->set_read_only) {
 402                 ret = bdev->bd_disk->fops->set_read_only(bdev, n);
 403                 if (ret)
 404                         return ret;
 405         }
 406         bdev->bd_read_only = n;
 407         return 0;
 408 }
 409
 410 static int blkdev_getgeo(struct block_device *bdev,
 411                 struct hd_geometry __user *argp)
 412 {
 413         struct gendisk *disk = bdev->bd_disk;
 414         struct hd_geometry geo;
 415         int ret;
 416
 417         if (!argp)
 418                 return -EINVAL;
 419         if (!disk->fops->getgeo)
 420                 return -ENOTTY;
 421
 422         /*
 423          * We need to set the startsect first, the driver may
 424          * want to override it.
 425          */
 426         memset(&geo, 0, sizeof(geo));
 427         geo.start = get_start_sect(bdev);
 428         ret = disk->fops->getgeo(bdev, &geo);
 429         if (ret)
 430                 return ret;
 431         if (copy_to_user(argp, &geo, sizeof(geo)))
 432                 return -EFAULT;
 433         return 0;
 434 }
 435
 436 #ifdef CONFIG_COMPAT
 437 struct compat_hd_geometry {
 438         unsigned char heads;
 439         unsigned char sectors;
 440         unsigned short cylinders;
 441         u32 start;
 442 };
 443
 444 static int compat_hdio_getgeo(struct block_device *bdev,
 445                               struct compat_hd_geometry __user *ugeo)
 446 {
 447         struct gendisk *disk = bdev->bd_disk;
 448         struct hd_geometry geo;
 449         int ret;
 450
 451         if (!ugeo)
 452                 return -EINVAL;
 453         if (!disk->fops->getgeo)
 454                 return -ENOTTY;
 455
 456         memset(&geo, 0, sizeof(geo));
 457         /*
 458          * We need to set the startsect first, the driver may
 459          * want to override it.
 460          */
 461         geo.start = get_start_sect(bdev);
 462         ret = disk->fops->getgeo(bdev, &geo);
 463         if (ret)
 464                 return ret;
 465
 466         ret = copy_to_user(ugeo, &geo, 4);
 467         ret |= put_user(geo.start, &ugeo->start);
 468         if (ret)
 469                 ret = -EFAULT;
 470
 471         return ret;
 472 }
 473 #endif
 474
 475 /* set the logical block size */
 476 static int blkdev_bszset(struct block_device *bdev, blk_mode_t mode,
 477                 int __user *argp)
 478 {
 479         int ret, n;
 480         struct file *file;
 481
 482         if (!capable(CAP_SYS_ADMIN))
 483                 return -EACCES;
 484         if (!argp)
 485                 return -EINVAL;
 486         if (get_user(n, argp))
 487                 return -EFAULT;
 488
 489         if (mode & BLK_OPEN_EXCL)
 490                 return set_blocksize(bdev, n);
 491
 492         file = bdev_file_open_by_dev(bdev->bd_dev, mode, &bdev, NULL);
 493         if (IS_ERR(file))
 494                 return -EBUSY;
 495         ret = set_blocksize(bdev, n);
 496         fput(file);
 497         return ret;
 498 }
 499
 500 /*
 501  * Common commands that are handled the same way on native and compat
 502  * user space. Note the separate arg/argp parameters that are needed
 503  * to deal with the compat_ptr() conversion.
 504  */
 505 static int blkdev_common_ioctl(struct block_device *bdev, blk_mode_t mode,
 506                                unsigned int cmd, unsigned long arg,
 507                                void __user *argp)
 508 {
 509         unsigned int max_sectors;
 510
 511         switch (cmd) {
 512         case BLKFLSBUF:
 513                 return blkdev_flushbuf(bdev, cmd, arg);
 514         case BLKROSET:
 515                 return blkdev_roset(bdev, cmd, arg);
 516         case BLKDISCARD:
 517                 return blk_ioctl_discard(bdev, mode, arg);
 518         case BLKSECDISCARD:
 519                 return blk_ioctl_secure_erase(bdev, mode, argp);
 520         case BLKZEROOUT:
 521                 return blk_ioctl_zeroout(bdev, mode, arg);
 522         case BLKGETDISKSEQ:
 523                 return put_u64(argp, bdev->bd_disk->diskseq);
 524         case BLKREPORTZONE:
 525                 return blkdev_report_zones_ioctl(bdev, cmd, arg);
 526         case BLKRESETZONE:
 527         case BLKOPENZONE:
 528         case BLKCLOSEZONE:
 529         case BLKFINISHZONE:
 530                 return blkdev_zone_mgmt_ioctl(bdev, mode, cmd, arg);
 531         case BLKGETZONESZ:
 532                 return put_uint(argp, bdev_zone_sectors(bdev));
 533         case BLKGETNRZONES:
 534                 return put_uint(argp, bdev_nr_zones(bdev));
 535         case BLKROGET:
 536                 return put_int(argp, bdev_read_only(bdev) != 0);
 537         case BLKSSZGET: /* get block device logical block size */
 538                 return put_int(argp, bdev_logical_block_size(bdev));
 539         case BLKPBSZGET: /* get block device physical block size */
 540                 return put_uint(argp, bdev_physical_block_size(bdev));
 541         case BLKIOMIN:
 542                 return put_uint(argp, bdev_io_min(bdev));
 543         case BLKIOOPT:
 544                 return put_uint(argp, bdev_io_opt(bdev));
 545         case BLKALIGNOFF:
 546                 return put_int(argp, bdev_alignment_offset(bdev));
 547         case BLKDISCARDZEROES:
 548                 return put_uint(argp, 0);
 549         case BLKSECTGET:
 550                 max_sectors = min_t(unsigned int, USHRT_MAX,
 551                                     queue_max_sectors(bdev_get_queue(bdev)));
 552                 return put_ushort(argp, max_sectors);
 553         case BLKROTATIONAL:
 554                 return put_ushort(argp, !bdev_nonrot(bdev));
 555         case BLKRASET:
 556         case BLKFRASET:
 557                 if(!capable(CAP_SYS_ADMIN))
 558                         return -EACCES;
 559                 bdev->bd_disk->bdi->ra_pages = (arg * 512) / PAGE_SIZE;
 560                 return 0;
 561         case BLKRRPART:
 562                 if (!capable(CAP_SYS_ADMIN))
 563                         return -EACCES;
 564                 if (bdev_is_partition(bdev))
 565                         return -EINVAL;
 566                 return disk_scan_partitions(bdev->bd_disk, mode);
 567         case BLKTRACESTART:
 568         case BLKTRACESTOP:
 569         case BLKTRACETEARDOWN:
 570                 return blk_trace_ioctl(bdev, cmd, argp);
 571         case IOC_PR_REGISTER:
 572                 return blkdev_pr_register(bdev, mode, argp);
 573         case IOC_PR_RESERVE:
 574                 return blkdev_pr_reserve(bdev, mode, argp);
 575         case IOC_PR_RELEASE:
 576                 return blkdev_pr_release(bdev, mode, argp);
 577         case IOC_PR_PREEMPT:
 578                 return blkdev_pr_preempt(bdev, mode, argp, false);
 579         case IOC_PR_PREEMPT_ABORT:
 580                 return blkdev_pr_preempt(bdev, mode, argp, true);
 581         case IOC_PR_CLEAR:
 582                 return blkdev_pr_clear(bdev, mode, argp);
 583         default:
 584                 return -ENOIOCTLCMD;
 585         }
 586 }
 587
 588 /*
 589  * Always keep this in sync with compat_blkdev_ioctl()
 590  * to handle all incompatible commands in both functions.
 591  *
 592  * New commands must be compatible and go into blkdev_common_ioctl
 593  */
 594 long blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 595 {
 596         struct block_device *bdev = I_BDEV(file->f_mapping->host);
 597         void __user *argp = (void __user *)arg;
 598         blk_mode_t mode = file_to_blk_mode(file);
 599         int ret;
 600
 601         switch (cmd) {
 602         /* These need separate implementations for the data structure */
 603         case HDIO_GETGEO:
 604                 return blkdev_getgeo(bdev, argp);
 605         case BLKPG:
 606                 return blkpg_ioctl(bdev, argp);
 607
 608         /* Compat mode returns 32-bit data instead of 'long' */
 609         case BLKRAGET:
 610         case BLKFRAGET:
 611                 if (!argp)
 612                         return -EINVAL;
 613                 return put_long(argp,
 614                         (bdev->bd_disk->bdi->ra_pages * PAGE_SIZE) / 512);
 615         case BLKGETSIZE:
 616                 if (bdev_nr_sectors(bdev) > ~0UL)
 617                         return -EFBIG;
 618                 return put_ulong(argp, bdev_nr_sectors(bdev));
 619
 620         /* The data is compatible, but the command number is different */
 621         case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */
 622                 return put_int(argp, block_size(bdev));
 623         case BLKBSZSET:
 624                 return blkdev_bszset(bdev, mode, argp);
 625         case BLKGETSIZE64:
 626                 return put_u64(argp, bdev_nr_bytes(bdev));
 627
 628         /* Incompatible alignment on i386 */
 629         case BLKTRACESETUP:
 630                 return blk_trace_ioctl(bdev, cmd, argp);
 631         default:
 632                 break;
 633         }
 634
 635         ret = blkdev_common_ioctl(bdev, mode, cmd, arg, argp);
 636         if (ret != -ENOIOCTLCMD)
 637                 return ret;
 638
 639         if (!bdev->bd_disk->fops->ioctl)
 640                 return -ENOTTY;
 641         return bdev->bd_disk->fops->ioctl(bdev, mode, cmd, arg);
 642 }
 643
 644 #ifdef CONFIG_COMPAT
 645
 646 #define BLKBSZGET_32            _IOR(0x12, 112, int)
 647 #define BLKBSZSET_32            _IOW(0x12, 113, int)
 648 #define BLKGETSIZE64_32         _IOR(0x12, 114, int)
 649
 650 /* Most of the generic ioctls are handled in the normal fallback path.
 651    This assumes the blkdev's low level compat_ioctl always returns
 652    ENOIOCTLCMD for unknown ioctls. */
 653 long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 654 {
 655         int ret;
 656         void __user *argp = compat_ptr(arg);
 657         struct block_device *bdev = I_BDEV(file->f_mapping->host);
 658         struct gendisk *disk = bdev->bd_disk;
 659         blk_mode_t mode = file_to_blk_mode(file);
 660
 661         switch (cmd) {
 662         /* These need separate implementations for the data structure */
 663         case HDIO_GETGEO:
 664                 return compat_hdio_getgeo(bdev, argp);
 665         case BLKPG:
 666                 return compat_blkpg_ioctl(bdev, argp);
 667
 668         /* Compat mode returns 32-bit data instead of 'long' */
 669         case BLKRAGET:
 670         case BLKFRAGET:
 671                 if (!argp)
 672                         return -EINVAL;
 673                 return compat_put_long(argp,
 674                         (bdev->bd_disk->bdi->ra_pages * PAGE_SIZE) / 512);
 675         case BLKGETSIZE:
 676                 if (bdev_nr_sectors(bdev) > ~(compat_ulong_t)0)
 677                         return -EFBIG;
 678                 return compat_put_ulong(argp, bdev_nr_sectors(bdev));
 679
 680         /* The data is compatible, but the command number is different */
 681         case BLKBSZGET_32: /* get the logical block size (cf. BLKSSZGET) */
 682                 return put_int(argp, bdev_logical_block_size(bdev));
 683         case BLKBSZSET_32:
 684                 return blkdev_bszset(bdev, mode, argp);
 685         case BLKGETSIZE64_32:
 686                 return put_u64(argp, bdev_nr_bytes(bdev));
 687
 688         /* Incompatible alignment on i386 */
 689         case BLKTRACESETUP32:
 690                 return blk_trace_ioctl(bdev, cmd, argp);
 691         default:
 692                 break;
 693         }
 694
 695         ret = blkdev_common_ioctl(bdev, mode, cmd, arg, argp);
 696         if (ret == -ENOIOCTLCMD && disk->fops->compat_ioctl)
 697                 ret = disk->fops->compat_ioctl(bdev, mode, cmd, arg);
 698
 699         return ret;
 700 }
 701 #endif