block/ioctl.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/capability.h>
   3 #include <linux/blkdev.h>
   4 #include <linux/export.h>
   5 #include <linux/gfp.h>
   6 #include <linux/blkpg.h>
   7 #include <linux/hdreg.h>
   8 #include <linux/backing-dev.h>
   9 #include <linux/fs.h>
  10 #include <linux/blktrace_api.h>
  11 #include <linux/pr.h>
  12 #include <linux/uaccess.h>
  13
  14 static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg)
  15 {
  16         struct block_device *bdevp;
  17         struct gendisk *disk;
  18         struct hd_struct *part, *lpart;
  19         struct blkpg_ioctl_arg a;
  20         struct blkpg_partition p;
  21         struct disk_part_iter piter;
  22         long long start, length;
  23         int partno;
  24
  25         if (!capable(CAP_SYS_ADMIN))
  26                 return -EACCES;
  27         if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg)))
  28                 return -EFAULT;
  29         if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition)))
  30                 return -EFAULT;
  31         disk = bdev->bd_disk;
  32         if (bdev != bdev->bd_contains)
  33                 return -EINVAL;
  34         partno = p.pno;
  35         if (partno <= 0)
  36                 return -EINVAL;
  37         switch (a.op) {
  38                 case BLKPG_ADD_PARTITION:
  39                         start = p.start >> 9;
  40                         length = p.length >> 9;
  41                         /* check for fit in a hd_struct */
  42                         if (sizeof(sector_t) == sizeof(long) &&
  43                             sizeof(long long) > sizeof(long)) {
  44                                 long pstart = start, plength = length;
  45                                 if (pstart != start || plength != length
  46                                     || pstart < 0 || plength < 0 || partno > 65535)
  47                                         return -EINVAL;
  48                         }
  49                         /* check if partition is aligned to blocksize */
  50                         if (p.start & (bdev_logical_block_size(bdev) - 1))
  51                                 return -EINVAL;
  52
  53                         mutex_lock(&bdev->bd_mutex);
  54
  55                         /* overlap? */
  56                         disk_part_iter_init(&piter, disk,
  57                                             DISK_PITER_INCL_EMPTY);
  58                         while ((part = disk_part_iter_next(&piter))) {
  59                                 if (!(start + length <= part->start_sect ||
  60                                       start >= part->start_sect + part->nr_sects)) {
  61                                         disk_part_iter_exit(&piter);
  62                                         mutex_unlock(&bdev->bd_mutex);
  63                                         return -EBUSY;
  64                                 }
  65                         }
  66                         disk_part_iter_exit(&piter);
  67
  68                         /* all seems OK */
  69                         part = add_partition(disk, partno, start, length,
  70                                              ADDPART_FLAG_NONE, NULL);
  71                         mutex_unlock(&bdev->bd_mutex);
  72                         return PTR_ERR_OR_ZERO(part);
  73                 case BLKPG_DEL_PARTITION:
  74                         part = disk_get_part(disk, partno);
  75                         if (!part)
  76                                 return -ENXIO;
  77
  78                         bdevp = bdget(part_devt(part));
  79                         disk_put_part(part);
  80                         if (!bdevp)
  81                                 return -ENOMEM;
  82
  83                         mutex_lock(&bdevp->bd_mutex);
  84                         if (bdevp->bd_openers) {
  85                                 mutex_unlock(&bdevp->bd_mutex);
  86                                 bdput(bdevp);
  87                                 return -EBUSY;
  88                         }
  89                         /* all seems OK */
  90                         fsync_bdev(bdevp);
  91                         invalidate_bdev(bdevp);
  92
  93                         mutex_lock_nested(&bdev->bd_mutex, 1);
  94                         delete_partition(disk, partno);
  95                         mutex_unlock(&bdev->bd_mutex);
  96                         mutex_unlock(&bdevp->bd_mutex);
  97                         bdput(bdevp);
  98
  99                         return 0;
 100                 case BLKPG_RESIZE_PARTITION:
 101                         start = p.start >> 9;
 102                         /* new length of partition in bytes */
 103                         length = p.length >> 9;
 104                         /* check for fit in a hd_struct */
 105                         if (sizeof(sector_t) == sizeof(long) &&
 106                             sizeof(long long) > sizeof(long)) {
 107                                 long pstart = start, plength = length;
 108                                 if (pstart != start || plength != length
 109                                     || pstart < 0 || plength < 0)
 110                                         return -EINVAL;
 111                         }
 112                         part = disk_get_part(disk, partno);
 113                         if (!part)
 114                                 return -ENXIO;
 115                         bdevp = bdget(part_devt(part));
 116                         if (!bdevp) {
 117                                 disk_put_part(part);
 118                                 return -ENOMEM;
 119                         }
 120                         mutex_lock(&bdevp->bd_mutex);
 121                         mutex_lock_nested(&bdev->bd_mutex, 1);
 122                         if (start != part->start_sect) {
 123                                 mutex_unlock(&bdevp->bd_mutex);
 124                                 mutex_unlock(&bdev->bd_mutex);
 125                                 bdput(bdevp);
 126                                 disk_put_part(part);
 127                                 return -EINVAL;
 128                         }
 129                         /* overlap? */
 130                         disk_part_iter_init(&piter, disk,
 131                                             DISK_PITER_INCL_EMPTY);
 132                         while ((lpart = disk_part_iter_next(&piter))) {
 133                                 if (lpart->partno != partno &&
 134                                    !(start + length <= lpart->start_sect ||
 135                                    start >= lpart->start_sect + lpart->nr_sects)
 136                                    ) {
 137                                         disk_part_iter_exit(&piter);
 138                                         mutex_unlock(&bdevp->bd_mutex);
 139                                         mutex_unlock(&bdev->bd_mutex);
 140                                         bdput(bdevp);
 141                                         disk_put_part(part);
 142                                         return -EBUSY;
 143                                 }
 144                         }
 145                         disk_part_iter_exit(&piter);
 146                         part_nr_sects_write(part, (sector_t)length);
 147                         i_size_write(bdevp->bd_inode, p.length);
 148                         mutex_unlock(&bdevp->bd_mutex);
 149                         mutex_unlock(&bdev->bd_mutex);
 150                         bdput(bdevp);
 151                         disk_put_part(part);
 152                         return 0;
 153                 default:
 154                         return -EINVAL;
 155         }
 156 }
 157
 158 /*
 159  * This is an exported API for the block driver, and will not
 160  * acquire bd_mutex. This API should be used in case that
 161  * caller has held bd_mutex already.
 162  */
 163 int __blkdev_reread_part(struct block_device *bdev)
 164 {
 165         struct gendisk *disk = bdev->bd_disk;
 166
 167         if (!disk_part_scan_enabled(disk) || bdev != bdev->bd_contains)
 168                 return -EINVAL;
 169         if (!capable(CAP_SYS_ADMIN))
 170                 return -EACCES;
 171
 172         lockdep_assert_held(&bdev->bd_mutex);
 173
 174         return rescan_partitions(disk, bdev);
 175 }
 176 EXPORT_SYMBOL(__blkdev_reread_part);
 177
 178 /*
 179  * This is an exported API for the block driver, and will
 180  * try to acquire bd_mutex. If bd_mutex has been held already
 181  * in current context, please call __blkdev_reread_part().
 182  *
 183  * Make sure the held locks in current context aren't required
 184  * in open()/close() handler and I/O path for avoiding ABBA deadlock:
 185  * - bd_mutex is held before calling block driver's open/close
 186  *   handler
 187  * - reading partition table may submit I/O to the block device
 188  */
 189 int blkdev_reread_part(struct block_device *bdev)
 190 {
 191         int res;
 192
 193         mutex_lock(&bdev->bd_mutex);
 194         res = __blkdev_reread_part(bdev);
 195         mutex_unlock(&bdev->bd_mutex);
 196
 197         return res;
 198 }
 199 EXPORT_SYMBOL(blkdev_reread_part);
 200
 201 static int blk_ioctl_discard(struct block_device *bdev, fmode_t mode,
 202                 unsigned long arg, unsigned long flags)
 203 {
 204         uint64_t range[2];
 205         uint64_t start, len;
 206         struct request_queue *q = bdev_get_queue(bdev);
 207         struct address_space *mapping = bdev->bd_inode->i_mapping;
 208
 209
 210         if (!(mode & FMODE_WRITE))
 211                 return -EBADF;
 212
 213         if (!blk_queue_discard(q))
 214                 return -EOPNOTSUPP;
 215
 216         if (copy_from_user(range, (void __user *)arg, sizeof(range)))
 217                 return -EFAULT;
 218
 219         start = range[0];
 220         len = range[1];
 221
 222         if (start & 511)
 223                 return -EINVAL;
 224         if (len & 511)
 225                 return -EINVAL;
 226
 227         if (start + len > i_size_read(bdev->bd_inode))
 228                 return -EINVAL;
 229         truncate_inode_pages_range(mapping, start, start + len - 1);
 230         return blkdev_issue_discard(bdev, start >> 9, len >> 9,
 231                                     GFP_KERNEL, flags);
 232 }
 233
 234 static int blk_ioctl_zeroout(struct block_device *bdev, fmode_t mode,
 235                 unsigned long arg)
 236 {
 237         uint64_t range[2];
 238         struct address_space *mapping;
 239         uint64_t start, end, len;
 240
 241         if (!(mode & FMODE_WRITE))
 242                 return -EBADF;
 243
 244         if (copy_from_user(range, (void __user *)arg, sizeof(range)))
 245                 return -EFAULT;
 246
 247         start = range[0];
 248         len = range[1];
 249         end = start + len - 1;
 250
 251         if (start & 511)
 252                 return -EINVAL;
 253         if (len & 511)
 254                 return -EINVAL;
 255         if (end >= (uint64_t)i_size_read(bdev->bd_inode))
 256                 return -EINVAL;
 257         if (end < start)
 258                 return -EINVAL;
 259
 260         /* Invalidate the page cache, including dirty pages */
 261         mapping = bdev->bd_inode->i_mapping;
 262         truncate_inode_pages_range(mapping, start, end);
 263
 264         return blkdev_issue_zeroout(bdev, start >> 9, len >> 9, GFP_KERNEL,
 265                         BLKDEV_ZERO_NOUNMAP);
 266 }
 267
 268 static int put_ushort(unsigned long arg, unsigned short val)
 269 {
 270         return put_user(val, (unsigned short __user *)arg);
 271 }
 272
 273 static int put_int(unsigned long arg, int val)
 274 {
 275         return put_user(val, (int __user *)arg);
 276 }
 277
 278 static int put_uint(unsigned long arg, unsigned int val)
 279 {
 280         return put_user(val, (unsigned int __user *)arg);
 281 }
 282
 283 static int put_long(unsigned long arg, long val)
 284 {
 285         return put_user(val, (long __user *)arg);
 286 }
 287
 288 static int put_ulong(unsigned long arg, unsigned long val)
 289 {
 290         return put_user(val, (unsigned long __user *)arg);
 291 }
 292
 293 static int put_u64(unsigned long arg, u64 val)
 294 {
 295         return put_user(val, (u64 __user *)arg);
 296 }
 297
 298 int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
 299                         unsigned cmd, unsigned long arg)
 300 {
 301         struct gendisk *disk = bdev->bd_disk;
 302
 303         if (disk->fops->ioctl)
 304                 return disk->fops->ioctl(bdev, mode, cmd, arg);
 305
 306         return -ENOTTY;
 307 }
 308 /*
 309  * For the record: _GPL here is only because somebody decided to slap it
 310  * on the previous export.  Sheer idiocy, since it wasn't copyrightable
 311  * at all and could be open-coded without any exports by anybody who cares.
 312  */
 313 EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);
 314
 315 static int blkdev_pr_register(struct block_device *bdev,
 316                 struct pr_registration __user *arg)
 317 {
 318         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
 319         struct pr_registration reg;
 320
 321         if (!capable(CAP_SYS_ADMIN))
 322                 return -EPERM;
 323         if (!ops || !ops->pr_register)
 324                 return -EOPNOTSUPP;
 325         if (copy_from_user(&reg, arg, sizeof(reg)))
 326                 return -EFAULT;
 327
 328         if (reg.flags & ~PR_FL_IGNORE_KEY)
 329                 return -EOPNOTSUPP;
 330         return ops->pr_register(bdev, reg.old_key, reg.new_key, reg.flags);
 331 }
 332
 333 static int blkdev_pr_reserve(struct block_device *bdev,
 334                 struct pr_reservation __user *arg)
 335 {
 336         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
 337         struct pr_reservation rsv;
 338
 339         if (!capable(CAP_SYS_ADMIN))
 340                 return -EPERM;
 341         if (!ops || !ops->pr_reserve)
 342                 return -EOPNOTSUPP;
 343         if (copy_from_user(&rsv, arg, sizeof(rsv)))
 344                 return -EFAULT;
 345
 346         if (rsv.flags & ~PR_FL_IGNORE_KEY)
 347                 return -EOPNOTSUPP;
 348         return ops->pr_reserve(bdev, rsv.key, rsv.type, rsv.flags);
 349 }
 350
 351 static int blkdev_pr_release(struct block_device *bdev,
 352                 struct pr_reservation __user *arg)
 353 {
 354         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
 355         struct pr_reservation rsv;
 356
 357         if (!capable(CAP_SYS_ADMIN))
 358                 return -EPERM;
 359         if (!ops || !ops->pr_release)
 360                 return -EOPNOTSUPP;
 361         if (copy_from_user(&rsv, arg, sizeof(rsv)))
 362                 return -EFAULT;
 363
 364         if (rsv.flags)
 365                 return -EOPNOTSUPP;
 366         return ops->pr_release(bdev, rsv.key, rsv.type);
 367 }
 368
 369 static int blkdev_pr_preempt(struct block_device *bdev,
 370                 struct pr_preempt __user *arg, bool abort)
 371 {
 372         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
 373         struct pr_preempt p;
 374
 375         if (!capable(CAP_SYS_ADMIN))
 376                 return -EPERM;
 377         if (!ops || !ops->pr_preempt)
 378                 return -EOPNOTSUPP;
 379         if (copy_from_user(&p, arg, sizeof(p)))
 380                 return -EFAULT;
 381
 382         if (p.flags)
 383                 return -EOPNOTSUPP;
 384         return ops->pr_preempt(bdev, p.old_key, p.new_key, p.type, abort);
 385 }
 386
 387 static int blkdev_pr_clear(struct block_device *bdev,
 388                 struct pr_clear __user *arg)
 389 {
 390         const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops;
 391         struct pr_clear c;
 392
 393         if (!capable(CAP_SYS_ADMIN))
 394                 return -EPERM;
 395         if (!ops || !ops->pr_clear)
 396                 return -EOPNOTSUPP;
 397         if (copy_from_user(&c, arg, sizeof(c)))
 398                 return -EFAULT;
 399
 400         if (c.flags)
 401                 return -EOPNOTSUPP;
 402         return ops->pr_clear(bdev, c.key);
 403 }
 404
 405 /*
 406  * Is it an unrecognized ioctl? The correct returns are either
 407  * ENOTTY (final) or ENOIOCTLCMD ("I don't know this one, try a
 408  * fallback"). ENOIOCTLCMD gets turned into ENOTTY by the ioctl
 409  * code before returning.
 410  *
 411  * Confused drivers sometimes return EINVAL, which is wrong. It
 412  * means "I understood the ioctl command, but the parameters to
 413  * it were wrong".
 414  *
 415  * We should aim to just fix the broken drivers, the EINVAL case
 416  * should go away.
 417  */
 418 static inline int is_unrecognized_ioctl(int ret)
 419 {
 420         return  ret == -EINVAL ||
 421                 ret == -ENOTTY ||
 422                 ret == -ENOIOCTLCMD;
 423 }
 424
 425 static int blkdev_flushbuf(struct block_device *bdev, fmode_t mode,
 426                 unsigned cmd, unsigned long arg)
 427 {
 428         int ret;
 429
 430         if (!capable(CAP_SYS_ADMIN))
 431                 return -EACCES;
 432
 433         ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
 434         if (!is_unrecognized_ioctl(ret))
 435                 return ret;
 436
 437         fsync_bdev(bdev);
 438         invalidate_bdev(bdev);
 439         return 0;
 440 }
 441
 442 static int blkdev_roset(struct block_device *bdev, fmode_t mode,
 443                 unsigned cmd, unsigned long arg)
 444 {
 445         int ret, n;
 446
 447         if (!capable(CAP_SYS_ADMIN))
 448                 return -EACCES;
 449
 450         ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
 451         if (!is_unrecognized_ioctl(ret))
 452                 return ret;
 453         if (get_user(n, (int __user *)arg))
 454                 return -EFAULT;
 455         set_device_ro(bdev, n);
 456         return 0;
 457 }
 458
 459 static int blkdev_getgeo(struct block_device *bdev,
 460                 struct hd_geometry __user *argp)
 461 {
 462         struct gendisk *disk = bdev->bd_disk;
 463         struct hd_geometry geo;
 464         int ret;
 465
 466         if (!argp)
 467                 return -EINVAL;
 468         if (!disk->fops->getgeo)
 469                 return -ENOTTY;
 470
 471         /*
 472          * We need to set the startsect first, the driver may
 473          * want to override it.
 474          */
 475         memset(&geo, 0, sizeof(geo));
 476         geo.start = get_start_sect(bdev);
 477         ret = disk->fops->getgeo(bdev, &geo);
 478         if (ret)
 479                 return ret;
 480         if (copy_to_user(argp, &geo, sizeof(geo)))
 481                 return -EFAULT;
 482         return 0;
 483 }
 484
 485 /* set the logical block size */
 486 static int blkdev_bszset(struct block_device *bdev, fmode_t mode,
 487                 int __user *argp)
 488 {
 489         int ret, n;
 490
 491         if (!capable(CAP_SYS_ADMIN))
 492                 return -EACCES;
 493         if (!argp)
 494                 return -EINVAL;
 495         if (get_user(n, argp))
 496                 return -EFAULT;
 497
 498         if (!(mode & FMODE_EXCL)) {
 499                 bdgrab(bdev);
 500                 if (blkdev_get(bdev, mode | FMODE_EXCL, &bdev) < 0)
 501                         return -EBUSY;
 502         }
 503
 504         ret = set_blocksize(bdev, n);
 505         if (!(mode & FMODE_EXCL))
 506                 blkdev_put(bdev, mode | FMODE_EXCL);
 507         return ret;
 508 }
 509
 510 /*
 511  * always keep this in sync with compat_blkdev_ioctl()
 512  */
 513 int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
 514                         unsigned long arg)
 515 {
 516         void __user *argp = (void __user *)arg;
 517         loff_t size;
 518         unsigned int max_sectors;
 519
 520         switch (cmd) {
 521         case BLKFLSBUF:
 522                 return blkdev_flushbuf(bdev, mode, cmd, arg);
 523         case BLKROSET:
 524                 return blkdev_roset(bdev, mode, cmd, arg);
 525         case BLKDISCARD:
 526                 return blk_ioctl_discard(bdev, mode, arg, 0);
 527         case BLKSECDISCARD:
 528                 return blk_ioctl_discard(bdev, mode, arg,
 529                                 BLKDEV_DISCARD_SECURE);
 530         case BLKZEROOUT:
 531                 return blk_ioctl_zeroout(bdev, mode, arg);
 532         case BLKREPORTZONE:
 533                 return blkdev_report_zones_ioctl(bdev, mode, cmd, arg);
 534         case BLKRESETZONE:
 535                 return blkdev_reset_zones_ioctl(bdev, mode, cmd, arg);
 536         case BLKGETZONESZ:
 537                 return put_uint(arg, bdev_zone_sectors(bdev));
 538         case BLKGETNRZONES:
 539                 return put_uint(arg, blkdev_nr_zones(bdev));
 540         case HDIO_GETGEO:
 541                 return blkdev_getgeo(bdev, argp);
 542         case BLKRAGET:
 543         case BLKFRAGET:
 544                 if (!arg)
 545                         return -EINVAL;
 546                 return put_long(arg, (bdev->bd_bdi->ra_pages*PAGE_SIZE) / 512);
 547         case BLKROGET:
 548                 return put_int(arg, bdev_read_only(bdev) != 0);
 549         case BLKBSZGET: /* get block device soft block size (cf. BLKSSZGET) */
 550                 return put_int(arg, block_size(bdev));
 551         case BLKSSZGET: /* get block device logical block size */
 552                 return put_int(arg, bdev_logical_block_size(bdev));
 553         case BLKPBSZGET: /* get block device physical block size */
 554                 return put_uint(arg, bdev_physical_block_size(bdev));
 555         case BLKIOMIN:
 556                 return put_uint(arg, bdev_io_min(bdev));
 557         case BLKIOOPT:
 558                 return put_uint(arg, bdev_io_opt(bdev));
 559         case BLKALIGNOFF:
 560                 return put_int(arg, bdev_alignment_offset(bdev));
 561         case BLKDISCARDZEROES:
 562                 return put_uint(arg, 0);
 563         case BLKSECTGET:
 564                 max_sectors = min_t(unsigned int, USHRT_MAX,
 565                                     queue_max_sectors(bdev_get_queue(bdev)));
 566                 return put_ushort(arg, max_sectors);
 567         case BLKROTATIONAL:
 568                 return put_ushort(arg, !blk_queue_nonrot(bdev_get_queue(bdev)));
 569         case BLKRASET:
 570         case BLKFRASET:
 571                 if(!capable(CAP_SYS_ADMIN))
 572                         return -EACCES;
 573                 bdev->bd_bdi->ra_pages = (arg * 512) / PAGE_SIZE;
 574                 return 0;
 575         case BLKBSZSET:
 576                 return blkdev_bszset(bdev, mode, argp);
 577         case BLKPG:
 578                 return blkpg_ioctl(bdev, argp);
 579         case BLKRRPART:
 580                 return blkdev_reread_part(bdev);
 581         case BLKGETSIZE:
 582                 size = i_size_read(bdev->bd_inode);
 583                 if ((size >> 9) > ~0UL)
 584                         return -EFBIG;
 585                 return put_ulong(arg, size >> 9);
 586         case BLKGETSIZE64:
 587                 return put_u64(arg, i_size_read(bdev->bd_inode));
 588         case BLKTRACESTART:
 589         case BLKTRACESTOP:
 590         case BLKTRACESETUP:
 591         case BLKTRACETEARDOWN:
 592                 return blk_trace_ioctl(bdev, cmd, argp);
 593         case IOC_PR_REGISTER:
 594                 return blkdev_pr_register(bdev, argp);
 595         case IOC_PR_RESERVE:
 596                 return blkdev_pr_reserve(bdev, argp);
 597         case IOC_PR_RELEASE:
 598                 return blkdev_pr_release(bdev, argp);
 599         case IOC_PR_PREEMPT:
 600                 return blkdev_pr_preempt(bdev, argp, false);
 601         case IOC_PR_PREEMPT_ABORT:
 602                 return blkdev_pr_preempt(bdev, argp, true);
 603         case IOC_PR_CLEAR:
 604                 return blkdev_pr_clear(bdev, argp);
 605         default:
 606                 return __blkdev_driver_ioctl(bdev, mode, cmd, arg);
 607         }
 608 }
 609 EXPORT_SYMBOL_GPL(blkdev_ioctl);