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