1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 1991-1998 Linus Torvalds 4 * Re-organised Feb 1998 Russell King 5 * Copyright (C) 2020 Christoph Hellwig 6 */ 7 #include <linux/fs.h> 8 #include <linux/major.h> 9 #include <linux/slab.h> 10 #include <linux/ctype.h> 11 #include <linux/vmalloc.h> 12 #include <linux/raid/detect.h> 13 #include "check.h" 14 15 static int (*const check_part[])(struct parsed_partitions *) = { 16 /* 17 * Probe partition formats with tables at disk address 0 18 * that also have an ADFS boot block at 0xdc0. 19 */ 20 #ifdef CONFIG_ACORN_PARTITION_ICS 21 adfspart_check_ICS, 22 #endif 23 #ifdef CONFIG_ACORN_PARTITION_POWERTEC 24 adfspart_check_POWERTEC, 25 #endif 26 #ifdef CONFIG_ACORN_PARTITION_EESOX 27 adfspart_check_EESOX, 28 #endif 29 30 /* 31 * Now move on to formats that only have partition info at 32 * disk address 0xdc0. Since these may also have stale 33 * PC/BIOS partition tables, they need to come before 34 * the msdos entry. 35 */ 36 #ifdef CONFIG_ACORN_PARTITION_CUMANA 37 adfspart_check_CUMANA, 38 #endif 39 #ifdef CONFIG_ACORN_PARTITION_ADFS 40 adfspart_check_ADFS, 41 #endif 42 43 #ifdef CONFIG_CMDLINE_PARTITION 44 cmdline_partition, 45 #endif 46 #ifdef CONFIG_EFI_PARTITION 47 efi_partition, /* this must come before msdos */ 48 #endif 49 #ifdef CONFIG_SGI_PARTITION 50 sgi_partition, 51 #endif 52 #ifdef CONFIG_LDM_PARTITION 53 ldm_partition, /* this must come before msdos */ 54 #endif 55 #ifdef CONFIG_MSDOS_PARTITION 56 msdos_partition, 57 #endif 58 #ifdef CONFIG_OSF_PARTITION 59 osf_partition, 60 #endif 61 #ifdef CONFIG_SUN_PARTITION 62 sun_partition, 63 #endif 64 #ifdef CONFIG_AMIGA_PARTITION 65 amiga_partition, 66 #endif 67 #ifdef CONFIG_ATARI_PARTITION 68 atari_partition, 69 #endif 70 #ifdef CONFIG_MAC_PARTITION 71 mac_partition, 72 #endif 73 #ifdef CONFIG_ULTRIX_PARTITION 74 ultrix_partition, 75 #endif 76 #ifdef CONFIG_IBM_PARTITION 77 ibm_partition, 78 #endif 79 #ifdef CONFIG_KARMA_PARTITION 80 karma_partition, 81 #endif 82 #ifdef CONFIG_SYSV68_PARTITION 83 sysv68_partition, 84 #endif 85 NULL 86 }; 87 88 static struct parsed_partitions *allocate_partitions(struct gendisk *hd) 89 { 90 struct parsed_partitions *state; 91 int nr = DISK_MAX_PARTS; 92 93 state = kzalloc(sizeof(*state), GFP_KERNEL); 94 if (!state) 95 return NULL; 96 97 state->parts = vzalloc(array_size(nr, sizeof(state->parts[0]))); 98 if (!state->parts) { 99 kfree(state); 100 return NULL; 101 } 102 103 state->limit = nr; 104 105 return state; 106 } 107 108 static void free_partitions(struct parsed_partitions *state) 109 { 110 vfree(state->parts); 111 kfree(state); 112 } 113 114 static struct parsed_partitions *check_partition(struct gendisk *hd) 115 { 116 struct parsed_partitions *state; 117 int i, res, err; 118 119 state = allocate_partitions(hd); 120 if (!state) 121 return NULL; 122 state->pp_buf = (char *)__get_free_page(GFP_KERNEL); 123 if (!state->pp_buf) { 124 free_partitions(state); 125 return NULL; 126 } 127 state->pp_buf[0] = '\0'; 128 129 state->disk = hd; 130 snprintf(state->name, BDEVNAME_SIZE, "%s", hd->disk_name); 131 snprintf(state->pp_buf, PAGE_SIZE, " %s:", state->name); 132 if (isdigit(state->name[strlen(state->name)-1])) 133 sprintf(state->name, "p"); 134 135 i = res = err = 0; 136 while (!res && check_part[i]) { 137 memset(state->parts, 0, state->limit * sizeof(state->parts[0])); 138 res = check_part[i++](state); 139 if (res < 0) { 140 /* 141 * We have hit an I/O error which we don't report now. 142 * But record it, and let the others do their job. 143 */ 144 err = res; 145 res = 0; 146 } 147 148 } 149 if (res > 0) { 150 printk(KERN_INFO "%s", state->pp_buf); 151 152 free_page((unsigned long)state->pp_buf); 153 return state; 154 } 155 if (state->access_beyond_eod) 156 err = -ENOSPC; 157 /* 158 * The partition is unrecognized. So report I/O errors if there were any 159 */ 160 if (err) 161 res = err; 162 if (res) { 163 strlcat(state->pp_buf, 164 " unable to read partition table\n", PAGE_SIZE); 165 printk(KERN_INFO "%s", state->pp_buf); 166 } 167 168 free_page((unsigned long)state->pp_buf); 169 free_partitions(state); 170 return ERR_PTR(res); 171 } 172 173 static ssize_t part_partition_show(struct device *dev, 174 struct device_attribute *attr, char *buf) 175 { 176 return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_partno); 177 } 178 179 static ssize_t part_start_show(struct device *dev, 180 struct device_attribute *attr, char *buf) 181 { 182 return sprintf(buf, "%llu\n", dev_to_bdev(dev)->bd_start_sect); 183 } 184 185 static ssize_t part_ro_show(struct device *dev, 186 struct device_attribute *attr, char *buf) 187 { 188 return sprintf(buf, "%d\n", bdev_read_only(dev_to_bdev(dev))); 189 } 190 191 static ssize_t part_alignment_offset_show(struct device *dev, 192 struct device_attribute *attr, char *buf) 193 { 194 return sprintf(buf, "%u\n", bdev_alignment_offset(dev_to_bdev(dev))); 195 } 196 197 static ssize_t part_discard_alignment_show(struct device *dev, 198 struct device_attribute *attr, char *buf) 199 { 200 return sprintf(buf, "%u\n", bdev_discard_alignment(dev_to_bdev(dev))); 201 } 202 203 static DEVICE_ATTR(partition, 0444, part_partition_show, NULL); 204 static DEVICE_ATTR(start, 0444, part_start_show, NULL); 205 static DEVICE_ATTR(size, 0444, part_size_show, NULL); 206 static DEVICE_ATTR(ro, 0444, part_ro_show, NULL); 207 static DEVICE_ATTR(alignment_offset, 0444, part_alignment_offset_show, NULL); 208 static DEVICE_ATTR(discard_alignment, 0444, part_discard_alignment_show, NULL); 209 static DEVICE_ATTR(stat, 0444, part_stat_show, NULL); 210 static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL); 211 #ifdef CONFIG_FAIL_MAKE_REQUEST 212 static struct device_attribute dev_attr_fail = 213 __ATTR(make-it-fail, 0644, part_fail_show, part_fail_store); 214 #endif 215 216 static struct attribute *part_attrs[] = { 217 &dev_attr_partition.attr, 218 &dev_attr_start.attr, 219 &dev_attr_size.attr, 220 &dev_attr_ro.attr, 221 &dev_attr_alignment_offset.attr, 222 &dev_attr_discard_alignment.attr, 223 &dev_attr_stat.attr, 224 &dev_attr_inflight.attr, 225 #ifdef CONFIG_FAIL_MAKE_REQUEST 226 &dev_attr_fail.attr, 227 #endif 228 NULL 229 }; 230 231 static const struct attribute_group part_attr_group = { 232 .attrs = part_attrs, 233 }; 234 235 static const struct attribute_group *part_attr_groups[] = { 236 &part_attr_group, 237 #ifdef CONFIG_BLK_DEV_IO_TRACE 238 &blk_trace_attr_group, 239 #endif 240 NULL 241 }; 242 243 static void part_release(struct device *dev) 244 { 245 put_disk(dev_to_bdev(dev)->bd_disk); 246 iput(dev_to_bdev(dev)->bd_inode); 247 } 248 249 static int part_uevent(const struct device *dev, struct kobj_uevent_env *env) 250 { 251 const struct block_device *part = dev_to_bdev(dev); 252 253 add_uevent_var(env, "PARTN=%u", part->bd_partno); 254 if (part->bd_meta_info && part->bd_meta_info->volname[0]) 255 add_uevent_var(env, "PARTNAME=%s", part->bd_meta_info->volname); 256 return 0; 257 } 258 259 const struct device_type part_type = { 260 .name = "partition", 261 .groups = part_attr_groups, 262 .release = part_release, 263 .uevent = part_uevent, 264 }; 265 266 void drop_partition(struct block_device *part) 267 { 268 lockdep_assert_held(&part->bd_disk->open_mutex); 269 270 xa_erase(&part->bd_disk->part_tbl, part->bd_partno); 271 kobject_put(part->bd_holder_dir); 272 273 device_del(&part->bd_device); 274 put_device(&part->bd_device); 275 } 276 277 static ssize_t whole_disk_show(struct device *dev, 278 struct device_attribute *attr, char *buf) 279 { 280 return 0; 281 } 282 static const DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL); 283 284 /* 285 * Must be called either with open_mutex held, before a disk can be opened or 286 * after all disk users are gone. 287 */ 288 static struct block_device *add_partition(struct gendisk *disk, int partno, 289 sector_t start, sector_t len, int flags, 290 struct partition_meta_info *info) 291 { 292 dev_t devt = MKDEV(0, 0); 293 struct device *ddev = disk_to_dev(disk); 294 struct device *pdev; 295 struct block_device *bdev; 296 const char *dname; 297 int err; 298 299 lockdep_assert_held(&disk->open_mutex); 300 301 if (partno >= DISK_MAX_PARTS) 302 return ERR_PTR(-EINVAL); 303 304 /* 305 * Partitions are not supported on zoned block devices that are used as 306 * such. 307 */ 308 if (bdev_is_zoned(disk->part0)) { 309 pr_warn("%s: partitions not supported on host managed zoned block device\n", 310 disk->disk_name); 311 return ERR_PTR(-ENXIO); 312 } 313 314 if (xa_load(&disk->part_tbl, partno)) 315 return ERR_PTR(-EBUSY); 316 317 /* ensure we always have a reference to the whole disk */ 318 get_device(disk_to_dev(disk)); 319 320 err = -ENOMEM; 321 bdev = bdev_alloc(disk, partno); 322 if (!bdev) 323 goto out_put_disk; 324 325 bdev->bd_start_sect = start; 326 bdev_set_nr_sectors(bdev, len); 327 328 pdev = &bdev->bd_device; 329 dname = dev_name(ddev); 330 if (isdigit(dname[strlen(dname) - 1])) 331 dev_set_name(pdev, "%sp%d", dname, partno); 332 else 333 dev_set_name(pdev, "%s%d", dname, partno); 334 335 device_initialize(pdev); 336 pdev->class = &block_class; 337 pdev->type = &part_type; 338 pdev->parent = ddev; 339 340 /* in consecutive minor range? */ 341 if (bdev->bd_partno < disk->minors) { 342 devt = MKDEV(disk->major, disk->first_minor + bdev->bd_partno); 343 } else { 344 err = blk_alloc_ext_minor(); 345 if (err < 0) 346 goto out_put; 347 devt = MKDEV(BLOCK_EXT_MAJOR, err); 348 } 349 pdev->devt = devt; 350 351 if (info) { 352 err = -ENOMEM; 353 bdev->bd_meta_info = kmemdup(info, sizeof(*info), GFP_KERNEL); 354 if (!bdev->bd_meta_info) 355 goto out_put; 356 } 357 358 /* delay uevent until 'holders' subdir is created */ 359 dev_set_uevent_suppress(pdev, 1); 360 err = device_add(pdev); 361 if (err) 362 goto out_put; 363 364 err = -ENOMEM; 365 bdev->bd_holder_dir = kobject_create_and_add("holders", &pdev->kobj); 366 if (!bdev->bd_holder_dir) 367 goto out_del; 368 369 dev_set_uevent_suppress(pdev, 0); 370 if (flags & ADDPART_FLAG_WHOLEDISK) { 371 err = device_create_file(pdev, &dev_attr_whole_disk); 372 if (err) 373 goto out_del; 374 } 375 376 /* everything is up and running, commence */ 377 err = xa_insert(&disk->part_tbl, partno, bdev, GFP_KERNEL); 378 if (err) 379 goto out_del; 380 bdev_add(bdev, devt); 381 382 /* suppress uevent if the disk suppresses it */ 383 if (!dev_get_uevent_suppress(ddev)) 384 kobject_uevent(&pdev->kobj, KOBJ_ADD); 385 return bdev; 386 387 out_del: 388 kobject_put(bdev->bd_holder_dir); 389 device_del(pdev); 390 out_put: 391 put_device(pdev); 392 return ERR_PTR(err); 393 out_put_disk: 394 put_disk(disk); 395 return ERR_PTR(err); 396 } 397 398 static bool partition_overlaps(struct gendisk *disk, sector_t start, 399 sector_t length, int skip_partno) 400 { 401 struct block_device *part; 402 bool overlap = false; 403 unsigned long idx; 404 405 rcu_read_lock(); 406 xa_for_each_start(&disk->part_tbl, idx, part, 1) { 407 if (part->bd_partno != skip_partno && 408 start < part->bd_start_sect + bdev_nr_sectors(part) && 409 start + length > part->bd_start_sect) { 410 overlap = true; 411 break; 412 } 413 } 414 rcu_read_unlock(); 415 416 return overlap; 417 } 418 419 int bdev_add_partition(struct gendisk *disk, int partno, sector_t start, 420 sector_t length) 421 { 422 struct block_device *part; 423 int ret; 424 425 mutex_lock(&disk->open_mutex); 426 if (!disk_live(disk)) { 427 ret = -ENXIO; 428 goto out; 429 } 430 431 if (disk->flags & GENHD_FL_NO_PART) { 432 ret = -EINVAL; 433 goto out; 434 } 435 436 if (partition_overlaps(disk, start, length, -1)) { 437 ret = -EBUSY; 438 goto out; 439 } 440 441 part = add_partition(disk, partno, start, length, 442 ADDPART_FLAG_NONE, NULL); 443 ret = PTR_ERR_OR_ZERO(part); 444 out: 445 mutex_unlock(&disk->open_mutex); 446 return ret; 447 } 448 449 int bdev_del_partition(struct gendisk *disk, int partno) 450 { 451 struct block_device *part = NULL; 452 int ret = -ENXIO; 453 454 mutex_lock(&disk->open_mutex); 455 part = xa_load(&disk->part_tbl, partno); 456 if (!part) 457 goto out_unlock; 458 459 ret = -EBUSY; 460 if (atomic_read(&part->bd_openers)) 461 goto out_unlock; 462 463 /* 464 * We verified that @part->bd_openers is zero above and so 465 * @part->bd_holder{_ops} can't be set. And since we hold 466 * @disk->open_mutex the device can't be claimed by anyone. 467 * 468 * So no need to call @part->bd_holder_ops->mark_dead() here. 469 * Just delete the partition and invalidate it. 470 */ 471 472 remove_inode_hash(part->bd_inode); 473 invalidate_bdev(part); 474 drop_partition(part); 475 ret = 0; 476 out_unlock: 477 mutex_unlock(&disk->open_mutex); 478 return ret; 479 } 480 481 int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start, 482 sector_t length) 483 { 484 struct block_device *part = NULL; 485 int ret = -ENXIO; 486 487 mutex_lock(&disk->open_mutex); 488 part = xa_load(&disk->part_tbl, partno); 489 if (!part) 490 goto out_unlock; 491 492 ret = -EINVAL; 493 if (start != part->bd_start_sect) 494 goto out_unlock; 495 496 ret = -EBUSY; 497 if (partition_overlaps(disk, start, length, partno)) 498 goto out_unlock; 499 500 bdev_set_nr_sectors(part, length); 501 502 ret = 0; 503 out_unlock: 504 mutex_unlock(&disk->open_mutex); 505 return ret; 506 } 507 508 static bool disk_unlock_native_capacity(struct gendisk *disk) 509 { 510 if (!disk->fops->unlock_native_capacity || 511 test_and_set_bit(GD_NATIVE_CAPACITY, &disk->state)) { 512 printk(KERN_CONT "truncated\n"); 513 return false; 514 } 515 516 printk(KERN_CONT "enabling native capacity\n"); 517 disk->fops->unlock_native_capacity(disk); 518 return true; 519 } 520 521 static bool blk_add_partition(struct gendisk *disk, 522 struct parsed_partitions *state, int p) 523 { 524 sector_t size = state->parts[p].size; 525 sector_t from = state->parts[p].from; 526 struct block_device *part; 527 528 if (!size) 529 return true; 530 531 if (from >= get_capacity(disk)) { 532 printk(KERN_WARNING 533 "%s: p%d start %llu is beyond EOD, ", 534 disk->disk_name, p, (unsigned long long) from); 535 if (disk_unlock_native_capacity(disk)) 536 return false; 537 return true; 538 } 539 540 if (from + size > get_capacity(disk)) { 541 printk(KERN_WARNING 542 "%s: p%d size %llu extends beyond EOD, ", 543 disk->disk_name, p, (unsigned long long) size); 544 545 if (disk_unlock_native_capacity(disk)) 546 return false; 547 548 /* 549 * We can not ignore partitions of broken tables created by for 550 * example camera firmware, but we limit them to the end of the 551 * disk to avoid creating invalid block devices. 552 */ 553 size = get_capacity(disk) - from; 554 } 555 556 part = add_partition(disk, p, from, size, state->parts[p].flags, 557 &state->parts[p].info); 558 if (IS_ERR(part) && PTR_ERR(part) != -ENXIO) { 559 printk(KERN_ERR " %s: p%d could not be added: %pe\n", 560 disk->disk_name, p, part); 561 return true; 562 } 563 564 if (IS_BUILTIN(CONFIG_BLK_DEV_MD) && 565 (state->parts[p].flags & ADDPART_FLAG_RAID)) 566 md_autodetect_dev(part->bd_dev); 567 568 return true; 569 } 570 571 static int blk_add_partitions(struct gendisk *disk) 572 { 573 struct parsed_partitions *state; 574 int ret = -EAGAIN, p; 575 576 if (disk->flags & GENHD_FL_NO_PART) 577 return 0; 578 579 if (test_bit(GD_SUPPRESS_PART_SCAN, &disk->state)) 580 return 0; 581 582 state = check_partition(disk); 583 if (!state) 584 return 0; 585 if (IS_ERR(state)) { 586 /* 587 * I/O error reading the partition table. If we tried to read 588 * beyond EOD, retry after unlocking the native capacity. 589 */ 590 if (PTR_ERR(state) == -ENOSPC) { 591 printk(KERN_WARNING "%s: partition table beyond EOD, ", 592 disk->disk_name); 593 if (disk_unlock_native_capacity(disk)) 594 return -EAGAIN; 595 } 596 return -EIO; 597 } 598 599 /* 600 * Partitions are not supported on host managed zoned block devices. 601 */ 602 if (bdev_is_zoned(disk->part0)) { 603 pr_warn("%s: ignoring partition table on host managed zoned block device\n", 604 disk->disk_name); 605 ret = 0; 606 goto out_free_state; 607 } 608 609 /* 610 * If we read beyond EOD, try unlocking native capacity even if the 611 * partition table was successfully read as we could be missing some 612 * partitions. 613 */ 614 if (state->access_beyond_eod) { 615 printk(KERN_WARNING 616 "%s: partition table partially beyond EOD, ", 617 disk->disk_name); 618 if (disk_unlock_native_capacity(disk)) 619 goto out_free_state; 620 } 621 622 /* tell userspace that the media / partition table may have changed */ 623 kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE); 624 625 for (p = 1; p < state->limit; p++) 626 if (!blk_add_partition(disk, state, p)) 627 goto out_free_state; 628 629 ret = 0; 630 out_free_state: 631 free_partitions(state); 632 return ret; 633 } 634 635 int bdev_disk_changed(struct gendisk *disk, bool invalidate) 636 { 637 struct block_device *part; 638 unsigned long idx; 639 int ret = 0; 640 641 lockdep_assert_held(&disk->open_mutex); 642 643 if (!disk_live(disk)) 644 return -ENXIO; 645 646 rescan: 647 if (disk->open_partitions) 648 return -EBUSY; 649 sync_blockdev(disk->part0); 650 invalidate_bdev(disk->part0); 651 652 xa_for_each_start(&disk->part_tbl, idx, part, 1) { 653 /* 654 * Remove the block device from the inode hash, so that 655 * it cannot be looked up any more even when openers 656 * still hold references. 657 */ 658 remove_inode_hash(part->bd_inode); 659 660 /* 661 * If @disk->open_partitions isn't elevated but there's 662 * still an active holder of that block device things 663 * are broken. 664 */ 665 WARN_ON_ONCE(atomic_read(&part->bd_openers)); 666 invalidate_bdev(part); 667 drop_partition(part); 668 } 669 clear_bit(GD_NEED_PART_SCAN, &disk->state); 670 671 /* 672 * Historically we only set the capacity to zero for devices that 673 * support partitions (independ of actually having partitions created). 674 * Doing that is rather inconsistent, but changing it broke legacy 675 * udisks polling for legacy ide-cdrom devices. Use the crude check 676 * below to get the sane behavior for most device while not breaking 677 * userspace for this particular setup. 678 */ 679 if (invalidate) { 680 if (!(disk->flags & GENHD_FL_NO_PART) || 681 !(disk->flags & GENHD_FL_REMOVABLE)) 682 set_capacity(disk, 0); 683 } 684 685 if (get_capacity(disk)) { 686 ret = blk_add_partitions(disk); 687 if (ret == -EAGAIN) 688 goto rescan; 689 } else if (invalidate) { 690 /* 691 * Tell userspace that the media / partition table may have 692 * changed. 693 */ 694 kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE); 695 } 696 697 return ret; 698 } 699 /* 700 * Only exported for loop and dasd for historic reasons. Don't use in new 701 * code! 702 */ 703 EXPORT_SYMBOL_GPL(bdev_disk_changed); 704 705 void *read_part_sector(struct parsed_partitions *state, sector_t n, Sector *p) 706 { 707 struct address_space *mapping = state->disk->part0->bd_inode->i_mapping; 708 struct folio *folio; 709 710 if (n >= get_capacity(state->disk)) { 711 state->access_beyond_eod = true; 712 goto out; 713 } 714 715 folio = read_mapping_folio(mapping, n >> PAGE_SECTORS_SHIFT, NULL); 716 if (IS_ERR(folio)) 717 goto out; 718 719 p->v = folio; 720 return folio_address(folio) + offset_in_folio(folio, n * SECTOR_SIZE); 721 out: 722 p->v = NULL; 723 return NULL; 724 } 725