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 static void delete_partition(struct block_device *part) 289 { 290 fsync_bdev(part); 291 __invalidate_device(part, true); 292 293 xa_erase(&part->bd_disk->part_tbl, part->bd_partno); 294 kobject_put(part->bd_holder_dir); 295 device_del(&part->bd_device); 296 297 /* 298 * Remove the block device from the inode hash, so that it cannot be 299 * looked up any more even when openers still hold references. 300 */ 301 remove_inode_hash(part->bd_inode); 302 303 put_device(&part->bd_device); 304 } 305 306 static ssize_t whole_disk_show(struct device *dev, 307 struct device_attribute *attr, char *buf) 308 { 309 return 0; 310 } 311 static DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL); 312 313 /* 314 * Must be called either with bd_mutex held, before a disk can be opened or 315 * after all disk users are gone. 316 */ 317 static struct block_device *add_partition(struct gendisk *disk, int partno, 318 sector_t start, sector_t len, int flags, 319 struct partition_meta_info *info) 320 { 321 dev_t devt = MKDEV(0, 0); 322 struct device *ddev = disk_to_dev(disk); 323 struct device *pdev; 324 struct block_device *bdev; 325 const char *dname; 326 int err; 327 328 /* 329 * disk_max_parts() won't be zero, either GENHD_FL_EXT_DEVT is set 330 * or 'minors' is passed to alloc_disk(). 331 */ 332 if (partno >= disk_max_parts(disk)) 333 return ERR_PTR(-EINVAL); 334 335 /* 336 * Partitions are not supported on zoned block devices that are used as 337 * such. 338 */ 339 switch (disk->queue->limits.zoned) { 340 case BLK_ZONED_HM: 341 pr_warn("%s: partitions not supported on host managed zoned block device\n", 342 disk->disk_name); 343 return ERR_PTR(-ENXIO); 344 case BLK_ZONED_HA: 345 pr_info("%s: disabling host aware zoned block device support due to partitions\n", 346 disk->disk_name); 347 blk_queue_set_zoned(disk, BLK_ZONED_NONE); 348 break; 349 case BLK_ZONED_NONE: 350 break; 351 } 352 353 if (xa_load(&disk->part_tbl, partno)) 354 return ERR_PTR(-EBUSY); 355 356 bdev = bdev_alloc(disk, partno); 357 if (!bdev) 358 return ERR_PTR(-ENOMEM); 359 360 bdev->bd_start_sect = start; 361 bdev_set_nr_sectors(bdev, len); 362 363 if (info) { 364 err = -ENOMEM; 365 bdev->bd_meta_info = kmemdup(info, sizeof(*info), GFP_KERNEL); 366 if (!bdev->bd_meta_info) 367 goto out_bdput; 368 } 369 370 pdev = &bdev->bd_device; 371 dname = dev_name(ddev); 372 if (isdigit(dname[strlen(dname) - 1])) 373 dev_set_name(pdev, "%sp%d", dname, partno); 374 else 375 dev_set_name(pdev, "%s%d", dname, partno); 376 377 device_initialize(pdev); 378 pdev->class = &block_class; 379 pdev->type = &part_type; 380 pdev->parent = ddev; 381 382 err = blk_alloc_devt(bdev, &devt); 383 if (err) 384 goto out_put; 385 pdev->devt = devt; 386 387 /* delay uevent until 'holders' subdir is created */ 388 dev_set_uevent_suppress(pdev, 1); 389 err = device_add(pdev); 390 if (err) 391 goto out_put; 392 393 err = -ENOMEM; 394 bdev->bd_holder_dir = kobject_create_and_add("holders", &pdev->kobj); 395 if (!bdev->bd_holder_dir) 396 goto out_del; 397 398 dev_set_uevent_suppress(pdev, 0); 399 if (flags & ADDPART_FLAG_WHOLEDISK) { 400 err = device_create_file(pdev, &dev_attr_whole_disk); 401 if (err) 402 goto out_del; 403 } 404 405 /* everything is up and running, commence */ 406 err = xa_insert(&disk->part_tbl, partno, bdev, GFP_KERNEL); 407 if (err) 408 goto out_del; 409 bdev_add(bdev, devt); 410 411 /* suppress uevent if the disk suppresses it */ 412 if (!dev_get_uevent_suppress(ddev)) 413 kobject_uevent(&pdev->kobj, KOBJ_ADD); 414 return bdev; 415 416 out_bdput: 417 bdput(bdev); 418 return ERR_PTR(err); 419 out_del: 420 kobject_put(bdev->bd_holder_dir); 421 device_del(pdev); 422 out_put: 423 put_device(pdev); 424 return ERR_PTR(err); 425 } 426 427 static bool partition_overlaps(struct gendisk *disk, sector_t start, 428 sector_t length, int skip_partno) 429 { 430 struct block_device *part; 431 bool overlap = false; 432 unsigned long idx; 433 434 rcu_read_lock(); 435 xa_for_each_start(&disk->part_tbl, idx, part, 1) { 436 if (part->bd_partno != skip_partno && 437 start < part->bd_start_sect + bdev_nr_sectors(part) && 438 start + length > part->bd_start_sect) { 439 overlap = true; 440 break; 441 } 442 } 443 rcu_read_unlock(); 444 445 return overlap; 446 } 447 448 int bdev_add_partition(struct block_device *bdev, int partno, 449 sector_t start, sector_t length) 450 { 451 struct block_device *part; 452 453 mutex_lock(&bdev->bd_mutex); 454 if (partition_overlaps(bdev->bd_disk, start, length, -1)) { 455 mutex_unlock(&bdev->bd_mutex); 456 return -EBUSY; 457 } 458 459 part = add_partition(bdev->bd_disk, partno, start, length, 460 ADDPART_FLAG_NONE, NULL); 461 mutex_unlock(&bdev->bd_mutex); 462 return PTR_ERR_OR_ZERO(part); 463 } 464 465 int bdev_del_partition(struct block_device *bdev, int partno) 466 { 467 struct block_device *part; 468 int ret; 469 470 part = bdget_disk(bdev->bd_disk, partno); 471 if (!part) 472 return -ENXIO; 473 474 mutex_lock(&part->bd_mutex); 475 mutex_lock_nested(&bdev->bd_mutex, 1); 476 477 ret = -EBUSY; 478 if (part->bd_openers) 479 goto out_unlock; 480 481 delete_partition(part); 482 ret = 0; 483 out_unlock: 484 mutex_unlock(&bdev->bd_mutex); 485 mutex_unlock(&part->bd_mutex); 486 bdput(part); 487 return ret; 488 } 489 490 int bdev_resize_partition(struct block_device *bdev, int partno, 491 sector_t start, sector_t length) 492 { 493 struct block_device *part; 494 int ret = 0; 495 496 part = bdget_disk(bdev->bd_disk, partno); 497 if (!part) 498 return -ENXIO; 499 500 mutex_lock(&part->bd_mutex); 501 mutex_lock_nested(&bdev->bd_mutex, 1); 502 ret = -EINVAL; 503 if (start != part->bd_start_sect) 504 goto out_unlock; 505 506 ret = -EBUSY; 507 if (partition_overlaps(bdev->bd_disk, start, length, partno)) 508 goto out_unlock; 509 510 bdev_set_nr_sectors(part, length); 511 512 ret = 0; 513 out_unlock: 514 mutex_unlock(&part->bd_mutex); 515 mutex_unlock(&bdev->bd_mutex); 516 bdput(part); 517 return ret; 518 } 519 520 static bool disk_unlock_native_capacity(struct gendisk *disk) 521 { 522 const struct block_device_operations *bdops = disk->fops; 523 524 if (bdops->unlock_native_capacity && 525 !(disk->flags & GENHD_FL_NATIVE_CAPACITY)) { 526 printk(KERN_CONT "enabling native capacity\n"); 527 bdops->unlock_native_capacity(disk); 528 disk->flags |= GENHD_FL_NATIVE_CAPACITY; 529 return true; 530 } else { 531 printk(KERN_CONT "truncated\n"); 532 return false; 533 } 534 } 535 536 void blk_drop_partitions(struct gendisk *disk) 537 { 538 struct block_device *part; 539 unsigned long idx; 540 541 lockdep_assert_held(&disk->part0->bd_mutex); 542 543 xa_for_each_start(&disk->part_tbl, idx, part, 1) { 544 if (!bdgrab(part)) 545 continue; 546 delete_partition(part); 547 bdput(part); 548 } 549 } 550 551 static bool blk_add_partition(struct gendisk *disk, struct block_device *bdev, 552 struct parsed_partitions *state, int p) 553 { 554 sector_t size = state->parts[p].size; 555 sector_t from = state->parts[p].from; 556 struct block_device *part; 557 558 if (!size) 559 return true; 560 561 if (from >= get_capacity(disk)) { 562 printk(KERN_WARNING 563 "%s: p%d start %llu is beyond EOD, ", 564 disk->disk_name, p, (unsigned long long) from); 565 if (disk_unlock_native_capacity(disk)) 566 return false; 567 return true; 568 } 569 570 if (from + size > get_capacity(disk)) { 571 printk(KERN_WARNING 572 "%s: p%d size %llu extends beyond EOD, ", 573 disk->disk_name, p, (unsigned long long) size); 574 575 if (disk_unlock_native_capacity(disk)) 576 return false; 577 578 /* 579 * We can not ignore partitions of broken tables created by for 580 * example camera firmware, but we limit them to the end of the 581 * disk to avoid creating invalid block devices. 582 */ 583 size = get_capacity(disk) - from; 584 } 585 586 part = add_partition(disk, p, from, size, state->parts[p].flags, 587 &state->parts[p].info); 588 if (IS_ERR(part) && PTR_ERR(part) != -ENXIO) { 589 printk(KERN_ERR " %s: p%d could not be added: %ld\n", 590 disk->disk_name, p, -PTR_ERR(part)); 591 return true; 592 } 593 594 if (IS_BUILTIN(CONFIG_BLK_DEV_MD) && 595 (state->parts[p].flags & ADDPART_FLAG_RAID)) 596 md_autodetect_dev(part->bd_dev); 597 598 return true; 599 } 600 601 int blk_add_partitions(struct gendisk *disk, struct block_device *bdev) 602 { 603 struct parsed_partitions *state; 604 int ret = -EAGAIN, p; 605 606 if (!disk_part_scan_enabled(disk)) 607 return 0; 608 609 state = check_partition(disk, bdev); 610 if (!state) 611 return 0; 612 if (IS_ERR(state)) { 613 /* 614 * I/O error reading the partition table. If we tried to read 615 * beyond EOD, retry after unlocking the native capacity. 616 */ 617 if (PTR_ERR(state) == -ENOSPC) { 618 printk(KERN_WARNING "%s: partition table beyond EOD, ", 619 disk->disk_name); 620 if (disk_unlock_native_capacity(disk)) 621 return -EAGAIN; 622 } 623 return -EIO; 624 } 625 626 /* 627 * Partitions are not supported on host managed zoned block devices. 628 */ 629 if (disk->queue->limits.zoned == BLK_ZONED_HM) { 630 pr_warn("%s: ignoring partition table on host managed zoned block device\n", 631 disk->disk_name); 632 ret = 0; 633 goto out_free_state; 634 } 635 636 /* 637 * If we read beyond EOD, try unlocking native capacity even if the 638 * partition table was successfully read as we could be missing some 639 * partitions. 640 */ 641 if (state->access_beyond_eod) { 642 printk(KERN_WARNING 643 "%s: partition table partially beyond EOD, ", 644 disk->disk_name); 645 if (disk_unlock_native_capacity(disk)) 646 goto out_free_state; 647 } 648 649 /* tell userspace that the media / partition table may have changed */ 650 kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE); 651 652 for (p = 1; p < state->limit; p++) 653 if (!blk_add_partition(disk, bdev, state, p)) 654 goto out_free_state; 655 656 ret = 0; 657 out_free_state: 658 free_partitions(state); 659 return ret; 660 } 661 662 void *read_part_sector(struct parsed_partitions *state, sector_t n, Sector *p) 663 { 664 struct address_space *mapping = state->bdev->bd_inode->i_mapping; 665 struct page *page; 666 667 if (n >= get_capacity(state->bdev->bd_disk)) { 668 state->access_beyond_eod = true; 669 return NULL; 670 } 671 672 page = read_mapping_page(mapping, 673 (pgoff_t)(n >> (PAGE_SHIFT - 9)), NULL); 674 if (IS_ERR(page)) 675 goto out; 676 if (PageError(page)) 677 goto out_put_page; 678 679 p->v = page; 680 return (unsigned char *)page_address(page) + 681 ((n & ((1 << (PAGE_SHIFT - 9)) - 1)) << SECTOR_SHIFT); 682 out_put_page: 683 put_page(page); 684 out: 685 p->v = NULL; 686 return NULL; 687 } 688