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 (*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 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 struct device_type part_type = { 260 .name = "partition", 261 .groups = part_attr_groups, 262 .release = part_release, 263 .uevent = part_uevent, 264 }; 265 266 static void delete_partition(struct block_device *part) 267 { 268 lockdep_assert_held(&part->bd_disk->open_mutex); 269 270 fsync_bdev(part); 271 __invalidate_device(part, true); 272 273 xa_erase(&part->bd_disk->part_tbl, part->bd_partno); 274 kobject_put(part->bd_holder_dir); 275 device_del(&part->bd_device); 276 277 /* 278 * Remove the block device from the inode hash, so that it cannot be 279 * looked up any more even when openers still hold references. 280 */ 281 remove_inode_hash(part->bd_inode); 282 283 put_device(&part->bd_device); 284 } 285 286 static ssize_t whole_disk_show(struct device *dev, 287 struct device_attribute *attr, char *buf) 288 { 289 return 0; 290 } 291 static DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL); 292 293 /* 294 * Must be called either with open_mutex held, before a disk can be opened or 295 * after all disk users are gone. 296 */ 297 static struct block_device *add_partition(struct gendisk *disk, int partno, 298 sector_t start, sector_t len, int flags, 299 struct partition_meta_info *info) 300 { 301 dev_t devt = MKDEV(0, 0); 302 struct device *ddev = disk_to_dev(disk); 303 struct device *pdev; 304 struct block_device *bdev; 305 const char *dname; 306 int err; 307 308 lockdep_assert_held(&disk->open_mutex); 309 310 if (partno >= DISK_MAX_PARTS) 311 return ERR_PTR(-EINVAL); 312 313 /* 314 * Partitions are not supported on zoned block devices that are used as 315 * such. 316 */ 317 switch (disk->queue->limits.zoned) { 318 case BLK_ZONED_HM: 319 pr_warn("%s: partitions not supported on host managed zoned block device\n", 320 disk->disk_name); 321 return ERR_PTR(-ENXIO); 322 case BLK_ZONED_HA: 323 pr_info("%s: disabling host aware zoned block device support due to partitions\n", 324 disk->disk_name); 325 disk_set_zoned(disk, BLK_ZONED_NONE); 326 break; 327 case BLK_ZONED_NONE: 328 break; 329 } 330 331 if (xa_load(&disk->part_tbl, partno)) 332 return ERR_PTR(-EBUSY); 333 334 /* ensure we always have a reference to the whole disk */ 335 get_device(disk_to_dev(disk)); 336 337 err = -ENOMEM; 338 bdev = bdev_alloc(disk, partno); 339 if (!bdev) 340 goto out_put_disk; 341 342 bdev->bd_start_sect = start; 343 bdev_set_nr_sectors(bdev, len); 344 345 pdev = &bdev->bd_device; 346 dname = dev_name(ddev); 347 if (isdigit(dname[strlen(dname) - 1])) 348 dev_set_name(pdev, "%sp%d", dname, partno); 349 else 350 dev_set_name(pdev, "%s%d", dname, partno); 351 352 device_initialize(pdev); 353 pdev->class = &block_class; 354 pdev->type = &part_type; 355 pdev->parent = ddev; 356 357 /* in consecutive minor range? */ 358 if (bdev->bd_partno < disk->minors) { 359 devt = MKDEV(disk->major, disk->first_minor + bdev->bd_partno); 360 } else { 361 err = blk_alloc_ext_minor(); 362 if (err < 0) 363 goto out_put; 364 devt = MKDEV(BLOCK_EXT_MAJOR, err); 365 } 366 pdev->devt = devt; 367 368 if (info) { 369 err = -ENOMEM; 370 bdev->bd_meta_info = kmemdup(info, sizeof(*info), GFP_KERNEL); 371 if (!bdev->bd_meta_info) 372 goto out_put; 373 } 374 375 /* delay uevent until 'holders' subdir is created */ 376 dev_set_uevent_suppress(pdev, 1); 377 err = device_add(pdev); 378 if (err) 379 goto out_put; 380 381 err = -ENOMEM; 382 bdev->bd_holder_dir = kobject_create_and_add("holders", &pdev->kobj); 383 if (!bdev->bd_holder_dir) 384 goto out_del; 385 386 dev_set_uevent_suppress(pdev, 0); 387 if (flags & ADDPART_FLAG_WHOLEDISK) { 388 err = device_create_file(pdev, &dev_attr_whole_disk); 389 if (err) 390 goto out_del; 391 } 392 393 /* everything is up and running, commence */ 394 err = xa_insert(&disk->part_tbl, partno, bdev, GFP_KERNEL); 395 if (err) 396 goto out_del; 397 bdev_add(bdev, devt); 398 399 /* suppress uevent if the disk suppresses it */ 400 if (!dev_get_uevent_suppress(ddev)) 401 kobject_uevent(&pdev->kobj, KOBJ_ADD); 402 return bdev; 403 404 out_del: 405 kobject_put(bdev->bd_holder_dir); 406 device_del(pdev); 407 out_put: 408 put_device(pdev); 409 return ERR_PTR(err); 410 out_put_disk: 411 put_disk(disk); 412 return ERR_PTR(err); 413 } 414 415 static bool partition_overlaps(struct gendisk *disk, sector_t start, 416 sector_t length, int skip_partno) 417 { 418 struct block_device *part; 419 bool overlap = false; 420 unsigned long idx; 421 422 rcu_read_lock(); 423 xa_for_each_start(&disk->part_tbl, idx, part, 1) { 424 if (part->bd_partno != skip_partno && 425 start < part->bd_start_sect + bdev_nr_sectors(part) && 426 start + length > part->bd_start_sect) { 427 overlap = true; 428 break; 429 } 430 } 431 rcu_read_unlock(); 432 433 return overlap; 434 } 435 436 int bdev_add_partition(struct gendisk *disk, int partno, sector_t start, 437 sector_t length) 438 { 439 struct block_device *part; 440 int ret; 441 442 mutex_lock(&disk->open_mutex); 443 if (!disk_live(disk)) { 444 ret = -ENXIO; 445 goto out; 446 } 447 448 if (partition_overlaps(disk, start, length, -1)) { 449 ret = -EBUSY; 450 goto out; 451 } 452 453 part = add_partition(disk, partno, start, length, 454 ADDPART_FLAG_NONE, NULL); 455 ret = PTR_ERR_OR_ZERO(part); 456 out: 457 mutex_unlock(&disk->open_mutex); 458 return ret; 459 } 460 461 int bdev_del_partition(struct gendisk *disk, int partno) 462 { 463 struct block_device *part = NULL; 464 int ret = -ENXIO; 465 466 mutex_lock(&disk->open_mutex); 467 part = xa_load(&disk->part_tbl, partno); 468 if (!part) 469 goto out_unlock; 470 471 ret = -EBUSY; 472 if (atomic_read(&part->bd_openers)) 473 goto out_unlock; 474 475 delete_partition(part); 476 ret = 0; 477 out_unlock: 478 mutex_unlock(&disk->open_mutex); 479 return ret; 480 } 481 482 int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start, 483 sector_t length) 484 { 485 struct block_device *part = NULL; 486 int ret = -ENXIO; 487 488 mutex_lock(&disk->open_mutex); 489 part = xa_load(&disk->part_tbl, partno); 490 if (!part) 491 goto out_unlock; 492 493 ret = -EINVAL; 494 if (start != part->bd_start_sect) 495 goto out_unlock; 496 497 ret = -EBUSY; 498 if (partition_overlaps(disk, start, length, partno)) 499 goto out_unlock; 500 501 bdev_set_nr_sectors(part, length); 502 503 ret = 0; 504 out_unlock: 505 mutex_unlock(&disk->open_mutex); 506 return ret; 507 } 508 509 static bool disk_unlock_native_capacity(struct gendisk *disk) 510 { 511 if (!disk->fops->unlock_native_capacity || 512 test_and_set_bit(GD_NATIVE_CAPACITY, &disk->state)) { 513 printk(KERN_CONT "truncated\n"); 514 return false; 515 } 516 517 printk(KERN_CONT "enabling native capacity\n"); 518 disk->fops->unlock_native_capacity(disk); 519 return true; 520 } 521 522 void blk_drop_partitions(struct gendisk *disk) 523 { 524 struct block_device *part; 525 unsigned long idx; 526 527 lockdep_assert_held(&disk->open_mutex); 528 529 xa_for_each_start(&disk->part_tbl, idx, part, 1) 530 delete_partition(part); 531 } 532 533 static bool blk_add_partition(struct gendisk *disk, 534 struct parsed_partitions *state, int p) 535 { 536 sector_t size = state->parts[p].size; 537 sector_t from = state->parts[p].from; 538 struct block_device *part; 539 540 if (!size) 541 return true; 542 543 if (from >= get_capacity(disk)) { 544 printk(KERN_WARNING 545 "%s: p%d start %llu is beyond EOD, ", 546 disk->disk_name, p, (unsigned long long) from); 547 if (disk_unlock_native_capacity(disk)) 548 return false; 549 return true; 550 } 551 552 if (from + size > get_capacity(disk)) { 553 printk(KERN_WARNING 554 "%s: p%d size %llu extends beyond EOD, ", 555 disk->disk_name, p, (unsigned long long) size); 556 557 if (disk_unlock_native_capacity(disk)) 558 return false; 559 560 /* 561 * We can not ignore partitions of broken tables created by for 562 * example camera firmware, but we limit them to the end of the 563 * disk to avoid creating invalid block devices. 564 */ 565 size = get_capacity(disk) - from; 566 } 567 568 part = add_partition(disk, p, from, size, state->parts[p].flags, 569 &state->parts[p].info); 570 if (IS_ERR(part) && PTR_ERR(part) != -ENXIO) { 571 printk(KERN_ERR " %s: p%d could not be added: %ld\n", 572 disk->disk_name, p, -PTR_ERR(part)); 573 return true; 574 } 575 576 if (IS_BUILTIN(CONFIG_BLK_DEV_MD) && 577 (state->parts[p].flags & ADDPART_FLAG_RAID)) 578 md_autodetect_dev(part->bd_dev); 579 580 return true; 581 } 582 583 static int blk_add_partitions(struct gendisk *disk) 584 { 585 struct parsed_partitions *state; 586 int ret = -EAGAIN, p; 587 588 if (disk->flags & GENHD_FL_NO_PART) 589 return 0; 590 591 if (test_bit(GD_SUPPRESS_PART_SCAN, &disk->state)) 592 return 0; 593 594 state = check_partition(disk); 595 if (!state) 596 return 0; 597 if (IS_ERR(state)) { 598 /* 599 * I/O error reading the partition table. If we tried to read 600 * beyond EOD, retry after unlocking the native capacity. 601 */ 602 if (PTR_ERR(state) == -ENOSPC) { 603 printk(KERN_WARNING "%s: partition table beyond EOD, ", 604 disk->disk_name); 605 if (disk_unlock_native_capacity(disk)) 606 return -EAGAIN; 607 } 608 return -EIO; 609 } 610 611 /* 612 * Partitions are not supported on host managed zoned block devices. 613 */ 614 if (disk->queue->limits.zoned == BLK_ZONED_HM) { 615 pr_warn("%s: ignoring partition table on host managed zoned block device\n", 616 disk->disk_name); 617 ret = 0; 618 goto out_free_state; 619 } 620 621 /* 622 * If we read beyond EOD, try unlocking native capacity even if the 623 * partition table was successfully read as we could be missing some 624 * partitions. 625 */ 626 if (state->access_beyond_eod) { 627 printk(KERN_WARNING 628 "%s: partition table partially beyond EOD, ", 629 disk->disk_name); 630 if (disk_unlock_native_capacity(disk)) 631 goto out_free_state; 632 } 633 634 /* tell userspace that the media / partition table may have changed */ 635 kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE); 636 637 for (p = 1; p < state->limit; p++) 638 if (!blk_add_partition(disk, state, p)) 639 goto out_free_state; 640 641 ret = 0; 642 out_free_state: 643 free_partitions(state); 644 return ret; 645 } 646 647 int bdev_disk_changed(struct gendisk *disk, bool invalidate) 648 { 649 int ret = 0; 650 651 lockdep_assert_held(&disk->open_mutex); 652 653 if (!disk_live(disk)) 654 return -ENXIO; 655 656 rescan: 657 if (disk->open_partitions) 658 return -EBUSY; 659 sync_blockdev(disk->part0); 660 invalidate_bdev(disk->part0); 661 blk_drop_partitions(disk); 662 663 clear_bit(GD_NEED_PART_SCAN, &disk->state); 664 665 /* 666 * Historically we only set the capacity to zero for devices that 667 * support partitions (independ of actually having partitions created). 668 * Doing that is rather inconsistent, but changing it broke legacy 669 * udisks polling for legacy ide-cdrom devices. Use the crude check 670 * below to get the sane behavior for most device while not breaking 671 * userspace for this particular setup. 672 */ 673 if (invalidate) { 674 if (!(disk->flags & GENHD_FL_NO_PART) || 675 !(disk->flags & GENHD_FL_REMOVABLE)) 676 set_capacity(disk, 0); 677 } 678 679 if (get_capacity(disk)) { 680 ret = blk_add_partitions(disk); 681 if (ret == -EAGAIN) 682 goto rescan; 683 } else if (invalidate) { 684 /* 685 * Tell userspace that the media / partition table may have 686 * changed. 687 */ 688 kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE); 689 } 690 691 return ret; 692 } 693 /* 694 * Only exported for loop and dasd for historic reasons. Don't use in new 695 * code! 696 */ 697 EXPORT_SYMBOL_GPL(bdev_disk_changed); 698 699 void *read_part_sector(struct parsed_partitions *state, sector_t n, Sector *p) 700 { 701 struct address_space *mapping = state->disk->part0->bd_inode->i_mapping; 702 struct folio *folio; 703 704 if (n >= get_capacity(state->disk)) { 705 state->access_beyond_eod = true; 706 goto out; 707 } 708 709 folio = read_mapping_folio(mapping, n >> PAGE_SECTORS_SHIFT, NULL); 710 if (IS_ERR(folio)) 711 goto out; 712 713 p->v = folio; 714 return folio_address(folio) + offset_in_folio(folio, n * SECTOR_SIZE); 715 out: 716 p->v = NULL; 717 return NULL; 718 } 719