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/slab.h> 9 #include <linux/ctype.h> 10 #include <linux/genhd.h> 11 #include <linux/vmalloc.h> 12 #include <linux/blktrace_api.h> 13 #include <linux/raid/detect.h> 14 #include "check.h" 15 16 static int (*check_part[])(struct parsed_partitions *) = { 17 /* 18 * Probe partition formats with tables at disk address 0 19 * that also have an ADFS boot block at 0xdc0. 20 */ 21 #ifdef CONFIG_ACORN_PARTITION_ICS 22 adfspart_check_ICS, 23 #endif 24 #ifdef CONFIG_ACORN_PARTITION_POWERTEC 25 adfspart_check_POWERTEC, 26 #endif 27 #ifdef CONFIG_ACORN_PARTITION_EESOX 28 adfspart_check_EESOX, 29 #endif 30 31 /* 32 * Now move on to formats that only have partition info at 33 * disk address 0xdc0. Since these may also have stale 34 * PC/BIOS partition tables, they need to come before 35 * the msdos entry. 36 */ 37 #ifdef CONFIG_ACORN_PARTITION_CUMANA 38 adfspart_check_CUMANA, 39 #endif 40 #ifdef CONFIG_ACORN_PARTITION_ADFS 41 adfspart_check_ADFS, 42 #endif 43 44 #ifdef CONFIG_CMDLINE_PARTITION 45 cmdline_partition, 46 #endif 47 #ifdef CONFIG_EFI_PARTITION 48 efi_partition, /* this must come before msdos */ 49 #endif 50 #ifdef CONFIG_SGI_PARTITION 51 sgi_partition, 52 #endif 53 #ifdef CONFIG_LDM_PARTITION 54 ldm_partition, /* this must come before msdos */ 55 #endif 56 #ifdef CONFIG_MSDOS_PARTITION 57 msdos_partition, 58 #endif 59 #ifdef CONFIG_OSF_PARTITION 60 osf_partition, 61 #endif 62 #ifdef CONFIG_SUN_PARTITION 63 sun_partition, 64 #endif 65 #ifdef CONFIG_AMIGA_PARTITION 66 amiga_partition, 67 #endif 68 #ifdef CONFIG_ATARI_PARTITION 69 atari_partition, 70 #endif 71 #ifdef CONFIG_MAC_PARTITION 72 mac_partition, 73 #endif 74 #ifdef CONFIG_ULTRIX_PARTITION 75 ultrix_partition, 76 #endif 77 #ifdef CONFIG_IBM_PARTITION 78 ibm_partition, 79 #endif 80 #ifdef CONFIG_KARMA_PARTITION 81 karma_partition, 82 #endif 83 #ifdef CONFIG_SYSV68_PARTITION 84 sysv68_partition, 85 #endif 86 NULL 87 }; 88 89 static void bdev_set_nr_sectors(struct block_device *bdev, sector_t sectors) 90 { 91 unsigned long flags; 92 93 spin_lock_irqsave(&bdev->bd_size_lock, flags); 94 i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT); 95 spin_unlock_irqrestore(&bdev->bd_size_lock, flags); 96 } 97 98 static struct parsed_partitions *allocate_partitions(struct gendisk *hd) 99 { 100 struct parsed_partitions *state; 101 int nr; 102 103 state = kzalloc(sizeof(*state), GFP_KERNEL); 104 if (!state) 105 return NULL; 106 107 nr = disk_max_parts(hd); 108 state->parts = vzalloc(array_size(nr, sizeof(state->parts[0]))); 109 if (!state->parts) { 110 kfree(state); 111 return NULL; 112 } 113 114 state->limit = nr; 115 116 return state; 117 } 118 119 static void free_partitions(struct parsed_partitions *state) 120 { 121 vfree(state->parts); 122 kfree(state); 123 } 124 125 static struct parsed_partitions *check_partition(struct gendisk *hd, 126 struct block_device *bdev) 127 { 128 struct parsed_partitions *state; 129 int i, res, err; 130 131 state = allocate_partitions(hd); 132 if (!state) 133 return NULL; 134 state->pp_buf = (char *)__get_free_page(GFP_KERNEL); 135 if (!state->pp_buf) { 136 free_partitions(state); 137 return NULL; 138 } 139 state->pp_buf[0] = '\0'; 140 141 state->bdev = bdev; 142 disk_name(hd, 0, state->name); 143 snprintf(state->pp_buf, PAGE_SIZE, " %s:", state->name); 144 if (isdigit(state->name[strlen(state->name)-1])) 145 sprintf(state->name, "p"); 146 147 i = res = err = 0; 148 while (!res && check_part[i]) { 149 memset(state->parts, 0, state->limit * sizeof(state->parts[0])); 150 res = check_part[i++](state); 151 if (res < 0) { 152 /* 153 * We have hit an I/O error which we don't report now. 154 * But record it, and let the others do their job. 155 */ 156 err = res; 157 res = 0; 158 } 159 160 } 161 if (res > 0) { 162 printk(KERN_INFO "%s", state->pp_buf); 163 164 free_page((unsigned long)state->pp_buf); 165 return state; 166 } 167 if (state->access_beyond_eod) 168 err = -ENOSPC; 169 /* 170 * The partition is unrecognized. So report I/O errors if there were any 171 */ 172 if (err) 173 res = err; 174 if (res) { 175 strlcat(state->pp_buf, 176 " unable to read partition table\n", PAGE_SIZE); 177 printk(KERN_INFO "%s", state->pp_buf); 178 } 179 180 free_page((unsigned long)state->pp_buf); 181 free_partitions(state); 182 return ERR_PTR(res); 183 } 184 185 static ssize_t part_partition_show(struct device *dev, 186 struct device_attribute *attr, char *buf) 187 { 188 return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_partno); 189 } 190 191 static ssize_t part_start_show(struct device *dev, 192 struct device_attribute *attr, char *buf) 193 { 194 return sprintf(buf, "%llu\n", dev_to_bdev(dev)->bd_start_sect); 195 } 196 197 static ssize_t part_ro_show(struct device *dev, 198 struct device_attribute *attr, char *buf) 199 { 200 return sprintf(buf, "%d\n", bdev_read_only(dev_to_bdev(dev))); 201 } 202 203 static ssize_t part_alignment_offset_show(struct device *dev, 204 struct device_attribute *attr, char *buf) 205 { 206 struct block_device *bdev = dev_to_bdev(dev); 207 208 return sprintf(buf, "%u\n", 209 queue_limit_alignment_offset(&bdev->bd_disk->queue->limits, 210 bdev->bd_start_sect)); 211 } 212 213 static ssize_t part_discard_alignment_show(struct device *dev, 214 struct device_attribute *attr, char *buf) 215 { 216 struct block_device *bdev = dev_to_bdev(dev); 217 218 return sprintf(buf, "%u\n", 219 queue_limit_discard_alignment(&bdev->bd_disk->queue->limits, 220 bdev->bd_start_sect)); 221 } 222 223 static DEVICE_ATTR(partition, 0444, part_partition_show, NULL); 224 static DEVICE_ATTR(start, 0444, part_start_show, NULL); 225 static DEVICE_ATTR(size, 0444, part_size_show, NULL); 226 static DEVICE_ATTR(ro, 0444, part_ro_show, NULL); 227 static DEVICE_ATTR(alignment_offset, 0444, part_alignment_offset_show, NULL); 228 static DEVICE_ATTR(discard_alignment, 0444, part_discard_alignment_show, NULL); 229 static DEVICE_ATTR(stat, 0444, part_stat_show, NULL); 230 static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL); 231 #ifdef CONFIG_FAIL_MAKE_REQUEST 232 static struct device_attribute dev_attr_fail = 233 __ATTR(make-it-fail, 0644, part_fail_show, part_fail_store); 234 #endif 235 236 static struct attribute *part_attrs[] = { 237 &dev_attr_partition.attr, 238 &dev_attr_start.attr, 239 &dev_attr_size.attr, 240 &dev_attr_ro.attr, 241 &dev_attr_alignment_offset.attr, 242 &dev_attr_discard_alignment.attr, 243 &dev_attr_stat.attr, 244 &dev_attr_inflight.attr, 245 #ifdef CONFIG_FAIL_MAKE_REQUEST 246 &dev_attr_fail.attr, 247 #endif 248 NULL 249 }; 250 251 static struct attribute_group part_attr_group = { 252 .attrs = part_attrs, 253 }; 254 255 static const struct attribute_group *part_attr_groups[] = { 256 &part_attr_group, 257 #ifdef CONFIG_BLK_DEV_IO_TRACE 258 &blk_trace_attr_group, 259 #endif 260 NULL 261 }; 262 263 static void part_release(struct device *dev) 264 { 265 blk_free_devt(dev->devt); 266 bdput(dev_to_bdev(dev)); 267 } 268 269 static int part_uevent(struct device *dev, struct kobj_uevent_env *env) 270 { 271 struct block_device *part = dev_to_bdev(dev); 272 273 add_uevent_var(env, "PARTN=%u", part->bd_partno); 274 if (part->bd_meta_info && part->bd_meta_info->volname[0]) 275 add_uevent_var(env, "PARTNAME=%s", part->bd_meta_info->volname); 276 return 0; 277 } 278 279 struct device_type part_type = { 280 .name = "partition", 281 .groups = part_attr_groups, 282 .release = part_release, 283 .uevent = part_uevent, 284 }; 285 286 /* 287 * Must be called either with bd_mutex held, before a disk can be opened or 288 * after all disk users are gone. 289 */ 290 void delete_partition(struct block_device *part) 291 { 292 xa_erase(&part->bd_disk->part_tbl, part->bd_partno); 293 kobject_put(part->bd_holder_dir); 294 device_del(&part->bd_device); 295 296 /* 297 * Remove the block device from the inode hash, so that it cannot be 298 * looked up any more even when openers still hold references. 299 */ 300 remove_inode_hash(part->bd_inode); 301 302 put_device(&part->bd_device); 303 } 304 305 static ssize_t whole_disk_show(struct device *dev, 306 struct device_attribute *attr, char *buf) 307 { 308 return 0; 309 } 310 static DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL); 311 312 /* 313 * Must be called either with bd_mutex held, before a disk can be opened or 314 * after all disk users are gone. 315 */ 316 static struct block_device *add_partition(struct gendisk *disk, int partno, 317 sector_t start, sector_t len, int flags, 318 struct partition_meta_info *info) 319 { 320 dev_t devt = MKDEV(0, 0); 321 struct device *ddev = disk_to_dev(disk); 322 struct device *pdev; 323 struct block_device *bdev; 324 const char *dname; 325 int err; 326 327 /* 328 * Partitions are not supported on zoned block devices that are used as 329 * such. 330 */ 331 switch (disk->queue->limits.zoned) { 332 case BLK_ZONED_HM: 333 pr_warn("%s: partitions not supported on host managed zoned block device\n", 334 disk->disk_name); 335 return ERR_PTR(-ENXIO); 336 case BLK_ZONED_HA: 337 pr_info("%s: disabling host aware zoned block device support due to partitions\n", 338 disk->disk_name); 339 blk_queue_set_zoned(disk, BLK_ZONED_NONE); 340 break; 341 case BLK_ZONED_NONE: 342 break; 343 } 344 345 if (xa_load(&disk->part_tbl, partno)) 346 return ERR_PTR(-EBUSY); 347 348 bdev = bdev_alloc(disk, partno); 349 if (!bdev) 350 return ERR_PTR(-ENOMEM); 351 352 bdev->bd_start_sect = start; 353 bdev_set_nr_sectors(bdev, len); 354 355 if (info) { 356 err = -ENOMEM; 357 bdev->bd_meta_info = kmemdup(info, sizeof(*info), GFP_KERNEL); 358 if (!bdev->bd_meta_info) 359 goto out_bdput; 360 } 361 362 pdev = &bdev->bd_device; 363 dname = dev_name(ddev); 364 if (isdigit(dname[strlen(dname) - 1])) 365 dev_set_name(pdev, "%sp%d", dname, partno); 366 else 367 dev_set_name(pdev, "%s%d", dname, partno); 368 369 device_initialize(pdev); 370 pdev->class = &block_class; 371 pdev->type = &part_type; 372 pdev->parent = ddev; 373 374 err = blk_alloc_devt(bdev, &devt); 375 if (err) 376 goto out_put; 377 pdev->devt = devt; 378 379 /* delay uevent until 'holders' subdir is created */ 380 dev_set_uevent_suppress(pdev, 1); 381 err = device_add(pdev); 382 if (err) 383 goto out_put; 384 385 err = -ENOMEM; 386 bdev->bd_holder_dir = kobject_create_and_add("holders", &pdev->kobj); 387 if (!bdev->bd_holder_dir) 388 goto out_del; 389 390 dev_set_uevent_suppress(pdev, 0); 391 if (flags & ADDPART_FLAG_WHOLEDISK) { 392 err = device_create_file(pdev, &dev_attr_whole_disk); 393 if (err) 394 goto out_del; 395 } 396 397 /* everything is up and running, commence */ 398 err = xa_insert(&disk->part_tbl, partno, bdev, GFP_KERNEL); 399 if (err) 400 goto out_del; 401 bdev_add(bdev, devt); 402 403 /* suppress uevent if the disk suppresses it */ 404 if (!dev_get_uevent_suppress(ddev)) 405 kobject_uevent(&pdev->kobj, KOBJ_ADD); 406 return bdev; 407 408 out_bdput: 409 bdput(bdev); 410 return ERR_PTR(err); 411 out_del: 412 kobject_put(bdev->bd_holder_dir); 413 device_del(pdev); 414 out_put: 415 put_device(pdev); 416 return ERR_PTR(err); 417 } 418 419 static bool partition_overlaps(struct gendisk *disk, sector_t start, 420 sector_t length, int skip_partno) 421 { 422 struct disk_part_iter piter; 423 struct block_device *part; 424 bool overlap = false; 425 426 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY); 427 while ((part = disk_part_iter_next(&piter))) { 428 if (part->bd_partno == skip_partno || 429 start >= part->bd_start_sect + bdev_nr_sectors(part) || 430 start + length <= part->bd_start_sect) 431 continue; 432 overlap = true; 433 break; 434 } 435 436 disk_part_iter_exit(&piter); 437 return overlap; 438 } 439 440 int bdev_add_partition(struct block_device *bdev, int partno, 441 sector_t start, sector_t length) 442 { 443 struct block_device *part; 444 445 mutex_lock(&bdev->bd_mutex); 446 if (partition_overlaps(bdev->bd_disk, start, length, -1)) { 447 mutex_unlock(&bdev->bd_mutex); 448 return -EBUSY; 449 } 450 451 part = add_partition(bdev->bd_disk, partno, start, length, 452 ADDPART_FLAG_NONE, NULL); 453 mutex_unlock(&bdev->bd_mutex); 454 return PTR_ERR_OR_ZERO(part); 455 } 456 457 int bdev_del_partition(struct block_device *bdev, int partno) 458 { 459 struct block_device *part; 460 int ret; 461 462 part = bdget_disk(bdev->bd_disk, partno); 463 if (!part) 464 return -ENXIO; 465 466 mutex_lock(&part->bd_mutex); 467 mutex_lock_nested(&bdev->bd_mutex, 1); 468 469 ret = -EBUSY; 470 if (part->bd_openers) 471 goto out_unlock; 472 473 sync_blockdev(part); 474 invalidate_bdev(part); 475 476 delete_partition(part); 477 ret = 0; 478 out_unlock: 479 mutex_unlock(&bdev->bd_mutex); 480 mutex_unlock(&part->bd_mutex); 481 bdput(part); 482 return ret; 483 } 484 485 int bdev_resize_partition(struct block_device *bdev, int partno, 486 sector_t start, sector_t length) 487 { 488 struct block_device *part; 489 int ret = 0; 490 491 part = bdget_disk(bdev->bd_disk, partno); 492 if (!part) 493 return -ENXIO; 494 495 mutex_lock(&part->bd_mutex); 496 mutex_lock_nested(&bdev->bd_mutex, 1); 497 ret = -EINVAL; 498 if (start != part->bd_start_sect) 499 goto out_unlock; 500 501 ret = -EBUSY; 502 if (partition_overlaps(bdev->bd_disk, start, length, partno)) 503 goto out_unlock; 504 505 bdev_set_nr_sectors(part, length); 506 507 ret = 0; 508 out_unlock: 509 mutex_unlock(&part->bd_mutex); 510 mutex_unlock(&bdev->bd_mutex); 511 bdput(part); 512 return ret; 513 } 514 515 static bool disk_unlock_native_capacity(struct gendisk *disk) 516 { 517 const struct block_device_operations *bdops = disk->fops; 518 519 if (bdops->unlock_native_capacity && 520 !(disk->flags & GENHD_FL_NATIVE_CAPACITY)) { 521 printk(KERN_CONT "enabling native capacity\n"); 522 bdops->unlock_native_capacity(disk); 523 disk->flags |= GENHD_FL_NATIVE_CAPACITY; 524 return true; 525 } else { 526 printk(KERN_CONT "truncated\n"); 527 return false; 528 } 529 } 530 531 int blk_drop_partitions(struct block_device *bdev) 532 { 533 struct disk_part_iter piter; 534 struct block_device *part; 535 536 if (bdev->bd_part_count) 537 return -EBUSY; 538 539 sync_blockdev(bdev); 540 invalidate_bdev(bdev); 541 542 disk_part_iter_init(&piter, bdev->bd_disk, DISK_PITER_INCL_EMPTY); 543 while ((part = disk_part_iter_next(&piter))) 544 delete_partition(part); 545 disk_part_iter_exit(&piter); 546 547 return 0; 548 } 549 #ifdef CONFIG_S390 550 /* for historic reasons in the DASD driver */ 551 EXPORT_SYMBOL_GPL(blk_drop_partitions); 552 #endif 553 554 static bool blk_add_partition(struct gendisk *disk, struct block_device *bdev, 555 struct parsed_partitions *state, int p) 556 { 557 sector_t size = state->parts[p].size; 558 sector_t from = state->parts[p].from; 559 struct block_device *part; 560 561 if (!size) 562 return true; 563 564 if (from >= get_capacity(disk)) { 565 printk(KERN_WARNING 566 "%s: p%d start %llu is beyond EOD, ", 567 disk->disk_name, p, (unsigned long long) from); 568 if (disk_unlock_native_capacity(disk)) 569 return false; 570 return true; 571 } 572 573 if (from + size > get_capacity(disk)) { 574 printk(KERN_WARNING 575 "%s: p%d size %llu extends beyond EOD, ", 576 disk->disk_name, p, (unsigned long long) size); 577 578 if (disk_unlock_native_capacity(disk)) 579 return false; 580 581 /* 582 * We can not ignore partitions of broken tables created by for 583 * example camera firmware, but we limit them to the end of the 584 * disk to avoid creating invalid block devices. 585 */ 586 size = get_capacity(disk) - from; 587 } 588 589 part = add_partition(disk, p, from, size, state->parts[p].flags, 590 &state->parts[p].info); 591 if (IS_ERR(part) && PTR_ERR(part) != -ENXIO) { 592 printk(KERN_ERR " %s: p%d could not be added: %ld\n", 593 disk->disk_name, p, -PTR_ERR(part)); 594 return true; 595 } 596 597 if (IS_BUILTIN(CONFIG_BLK_DEV_MD) && 598 (state->parts[p].flags & ADDPART_FLAG_RAID)) 599 md_autodetect_dev(part->bd_dev); 600 601 return true; 602 } 603 604 int blk_add_partitions(struct gendisk *disk, struct block_device *bdev) 605 { 606 struct parsed_partitions *state; 607 int ret = -EAGAIN, p; 608 609 if (!disk_part_scan_enabled(disk)) 610 return 0; 611 612 state = check_partition(disk, bdev); 613 if (!state) 614 return 0; 615 if (IS_ERR(state)) { 616 /* 617 * I/O error reading the partition table. If we tried to read 618 * beyond EOD, retry after unlocking the native capacity. 619 */ 620 if (PTR_ERR(state) == -ENOSPC) { 621 printk(KERN_WARNING "%s: partition table beyond EOD, ", 622 disk->disk_name); 623 if (disk_unlock_native_capacity(disk)) 624 return -EAGAIN; 625 } 626 return -EIO; 627 } 628 629 /* 630 * Partitions are not supported on host managed zoned block devices. 631 */ 632 if (disk->queue->limits.zoned == BLK_ZONED_HM) { 633 pr_warn("%s: ignoring partition table on host managed zoned block device\n", 634 disk->disk_name); 635 ret = 0; 636 goto out_free_state; 637 } 638 639 /* 640 * If we read beyond EOD, try unlocking native capacity even if the 641 * partition table was successfully read as we could be missing some 642 * partitions. 643 */ 644 if (state->access_beyond_eod) { 645 printk(KERN_WARNING 646 "%s: partition table partially beyond EOD, ", 647 disk->disk_name); 648 if (disk_unlock_native_capacity(disk)) 649 goto out_free_state; 650 } 651 652 /* tell userspace that the media / partition table may have changed */ 653 kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE); 654 655 for (p = 1; p < state->limit; p++) 656 if (!blk_add_partition(disk, bdev, state, p)) 657 goto out_free_state; 658 659 ret = 0; 660 out_free_state: 661 free_partitions(state); 662 return ret; 663 } 664 665 void *read_part_sector(struct parsed_partitions *state, sector_t n, Sector *p) 666 { 667 struct address_space *mapping = state->bdev->bd_inode->i_mapping; 668 struct page *page; 669 670 if (n >= get_capacity(state->bdev->bd_disk)) { 671 state->access_beyond_eod = true; 672 return NULL; 673 } 674 675 page = read_mapping_page(mapping, 676 (pgoff_t)(n >> (PAGE_SHIFT - 9)), NULL); 677 if (IS_ERR(page)) 678 goto out; 679 if (PageError(page)) 680 goto out_put_page; 681 682 p->v = page; 683 return (unsigned char *)page_address(page) + 684 ((n & ((1 << (PAGE_SHIFT - 9)) - 1)) << SECTOR_SHIFT); 685 out_put_page: 686 put_page(page); 687 out: 688 p->v = NULL; 689 return NULL; 690 } 691