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