Line data Source code
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 0 : static struct parsed_partitions *allocate_partitions(struct gendisk *hd)
89 : {
90 : struct parsed_partitions *state;
91 0 : int nr = DISK_MAX_PARTS;
92 :
93 0 : state = kzalloc(sizeof(*state), GFP_KERNEL);
94 0 : if (!state)
95 : return NULL;
96 :
97 0 : state->parts = vzalloc(array_size(nr, sizeof(state->parts[0])));
98 0 : if (!state->parts) {
99 0 : kfree(state);
100 : return NULL;
101 : }
102 :
103 0 : state->limit = nr;
104 :
105 : return state;
106 : }
107 :
108 : static void free_partitions(struct parsed_partitions *state)
109 : {
110 0 : vfree(state->parts);
111 0 : kfree(state);
112 : }
113 :
114 0 : static struct parsed_partitions *check_partition(struct gendisk *hd)
115 : {
116 : struct parsed_partitions *state;
117 : int i, res, err;
118 :
119 0 : state = allocate_partitions(hd);
120 0 : if (!state)
121 : return NULL;
122 0 : state->pp_buf = (char *)__get_free_page(GFP_KERNEL);
123 0 : if (!state->pp_buf) {
124 0 : free_partitions(state);
125 0 : return NULL;
126 : }
127 0 : state->pp_buf[0] = '\0';
128 :
129 0 : state->disk = hd;
130 0 : snprintf(state->name, BDEVNAME_SIZE, "%s", hd->disk_name);
131 0 : snprintf(state->pp_buf, PAGE_SIZE, " %s:", state->name);
132 0 : if (isdigit(state->name[strlen(state->name)-1]))
133 0 : sprintf(state->name, "p");
134 :
135 : i = res = err = 0;
136 0 : while (!res && check_part[i]) {
137 0 : memset(state->parts, 0, state->limit * sizeof(state->parts[0]));
138 0 : res = check_part[i++](state);
139 0 : 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 0 : err = res;
145 0 : res = 0;
146 : }
147 :
148 : }
149 0 : if (res > 0) {
150 0 : printk(KERN_INFO "%s", state->pp_buf);
151 :
152 0 : free_page((unsigned long)state->pp_buf);
153 0 : return state;
154 : }
155 0 : if (state->access_beyond_eod)
156 0 : err = -ENOSPC;
157 : /*
158 : * The partition is unrecognized. So report I/O errors if there were any
159 : */
160 0 : if (err)
161 0 : res = err;
162 0 : if (res) {
163 0 : strlcat(state->pp_buf,
164 : " unable to read partition table\n", PAGE_SIZE);
165 0 : printk(KERN_INFO "%s", state->pp_buf);
166 : }
167 :
168 0 : free_page((unsigned long)state->pp_buf);
169 0 : free_partitions(state);
170 0 : return ERR_PTR(res);
171 : }
172 :
173 0 : static ssize_t part_partition_show(struct device *dev,
174 : struct device_attribute *attr, char *buf)
175 : {
176 0 : return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_partno);
177 : }
178 :
179 0 : static ssize_t part_start_show(struct device *dev,
180 : struct device_attribute *attr, char *buf)
181 : {
182 0 : return sprintf(buf, "%llu\n", dev_to_bdev(dev)->bd_start_sect);
183 : }
184 :
185 0 : static ssize_t part_ro_show(struct device *dev,
186 : struct device_attribute *attr, char *buf)
187 : {
188 0 : return sprintf(buf, "%d\n", bdev_read_only(dev_to_bdev(dev)));
189 : }
190 :
191 0 : static ssize_t part_alignment_offset_show(struct device *dev,
192 : struct device_attribute *attr, char *buf)
193 : {
194 0 : return sprintf(buf, "%u\n", bdev_alignment_offset(dev_to_bdev(dev)));
195 : }
196 :
197 0 : static ssize_t part_discard_alignment_show(struct device *dev,
198 : struct device_attribute *attr, char *buf)
199 : {
200 0 : 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 0 : static void part_release(struct device *dev)
244 : {
245 0 : put_disk(dev_to_bdev(dev)->bd_disk);
246 0 : iput(dev_to_bdev(dev)->bd_inode);
247 0 : }
248 :
249 0 : static int part_uevent(const struct device *dev, struct kobj_uevent_env *env)
250 : {
251 0 : const struct block_device *part = dev_to_bdev(dev);
252 :
253 0 : add_uevent_var(env, "PARTN=%u", part->bd_partno);
254 0 : if (part->bd_meta_info && part->bd_meta_info->volname[0])
255 0 : add_uevent_var(env, "PARTNAME=%s", part->bd_meta_info->volname);
256 0 : 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 0 : void drop_partition(struct block_device *part)
267 : {
268 0 : lockdep_assert_held(&part->bd_disk->open_mutex);
269 :
270 0 : xa_erase(&part->bd_disk->part_tbl, part->bd_partno);
271 0 : kobject_put(part->bd_holder_dir);
272 :
273 0 : device_del(&part->bd_device);
274 0 : put_device(&part->bd_device);
275 0 : }
276 :
277 0 : static void delete_partition(struct block_device *part)
278 : {
279 : /*
280 : * Remove the block device from the inode hash, so that it cannot be
281 : * looked up any more even when openers still hold references.
282 : */
283 0 : remove_inode_hash(part->bd_inode);
284 :
285 0 : fsync_bdev(part);
286 0 : __invalidate_device(part, true);
287 :
288 0 : drop_partition(part);
289 0 : }
290 :
291 0 : static ssize_t whole_disk_show(struct device *dev,
292 : struct device_attribute *attr, char *buf)
293 : {
294 0 : return 0;
295 : }
296 : static const DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL);
297 :
298 : /*
299 : * Must be called either with open_mutex held, before a disk can be opened or
300 : * after all disk users are gone.
301 : */
302 0 : static struct block_device *add_partition(struct gendisk *disk, int partno,
303 : sector_t start, sector_t len, int flags,
304 : struct partition_meta_info *info)
305 : {
306 0 : dev_t devt = MKDEV(0, 0);
307 0 : struct device *ddev = disk_to_dev(disk);
308 : struct device *pdev;
309 : struct block_device *bdev;
310 : const char *dname;
311 : int err;
312 :
313 : lockdep_assert_held(&disk->open_mutex);
314 :
315 0 : if (partno >= DISK_MAX_PARTS)
316 : return ERR_PTR(-EINVAL);
317 :
318 : /*
319 : * Partitions are not supported on zoned block devices that are used as
320 : * such.
321 : */
322 0 : switch (disk->queue->limits.zoned) {
323 : case BLK_ZONED_HM:
324 0 : pr_warn("%s: partitions not supported on host managed zoned block device\n",
325 : disk->disk_name);
326 0 : return ERR_PTR(-ENXIO);
327 : case BLK_ZONED_HA:
328 0 : pr_info("%s: disabling host aware zoned block device support due to partitions\n",
329 : disk->disk_name);
330 0 : disk_set_zoned(disk, BLK_ZONED_NONE);
331 0 : break;
332 : case BLK_ZONED_NONE:
333 : break;
334 : }
335 :
336 0 : if (xa_load(&disk->part_tbl, partno))
337 : return ERR_PTR(-EBUSY);
338 :
339 : /* ensure we always have a reference to the whole disk */
340 0 : get_device(disk_to_dev(disk));
341 :
342 0 : err = -ENOMEM;
343 0 : bdev = bdev_alloc(disk, partno);
344 0 : if (!bdev)
345 : goto out_put_disk;
346 :
347 0 : bdev->bd_start_sect = start;
348 0 : bdev_set_nr_sectors(bdev, len);
349 :
350 0 : pdev = &bdev->bd_device;
351 0 : dname = dev_name(ddev);
352 0 : if (isdigit(dname[strlen(dname) - 1]))
353 0 : dev_set_name(pdev, "%sp%d", dname, partno);
354 : else
355 0 : dev_set_name(pdev, "%s%d", dname, partno);
356 :
357 0 : device_initialize(pdev);
358 0 : pdev->class = &block_class;
359 0 : pdev->type = &part_type;
360 0 : pdev->parent = ddev;
361 :
362 : /* in consecutive minor range? */
363 0 : if (bdev->bd_partno < disk->minors) {
364 0 : devt = MKDEV(disk->major, disk->first_minor + bdev->bd_partno);
365 : } else {
366 0 : err = blk_alloc_ext_minor();
367 0 : if (err < 0)
368 : goto out_put;
369 0 : devt = MKDEV(BLOCK_EXT_MAJOR, err);
370 : }
371 0 : pdev->devt = devt;
372 :
373 0 : if (info) {
374 0 : err = -ENOMEM;
375 0 : bdev->bd_meta_info = kmemdup(info, sizeof(*info), GFP_KERNEL);
376 0 : if (!bdev->bd_meta_info)
377 : goto out_put;
378 : }
379 :
380 : /* delay uevent until 'holders' subdir is created */
381 0 : dev_set_uevent_suppress(pdev, 1);
382 0 : err = device_add(pdev);
383 0 : if (err)
384 : goto out_put;
385 :
386 0 : err = -ENOMEM;
387 0 : bdev->bd_holder_dir = kobject_create_and_add("holders", &pdev->kobj);
388 0 : if (!bdev->bd_holder_dir)
389 : goto out_del;
390 :
391 0 : dev_set_uevent_suppress(pdev, 0);
392 0 : if (flags & ADDPART_FLAG_WHOLEDISK) {
393 0 : err = device_create_file(pdev, &dev_attr_whole_disk);
394 0 : if (err)
395 : goto out_del;
396 : }
397 :
398 : /* everything is up and running, commence */
399 0 : err = xa_insert(&disk->part_tbl, partno, bdev, GFP_KERNEL);
400 0 : if (err)
401 : goto out_del;
402 0 : bdev_add(bdev, devt);
403 :
404 : /* suppress uevent if the disk suppresses it */
405 0 : if (!dev_get_uevent_suppress(ddev))
406 0 : kobject_uevent(&pdev->kobj, KOBJ_ADD);
407 : return bdev;
408 :
409 : out_del:
410 0 : kobject_put(bdev->bd_holder_dir);
411 0 : device_del(pdev);
412 : out_put:
413 0 : put_device(pdev);
414 0 : return ERR_PTR(err);
415 : out_put_disk:
416 0 : put_disk(disk);
417 0 : return ERR_PTR(err);
418 : }
419 :
420 0 : static bool partition_overlaps(struct gendisk *disk, sector_t start,
421 : sector_t length, int skip_partno)
422 : {
423 : struct block_device *part;
424 0 : bool overlap = false;
425 : unsigned long idx;
426 :
427 : rcu_read_lock();
428 0 : xa_for_each_start(&disk->part_tbl, idx, part, 1) {
429 0 : if (part->bd_partno != skip_partno &&
430 0 : start < part->bd_start_sect + bdev_nr_sectors(part) &&
431 0 : start + length > part->bd_start_sect) {
432 : overlap = true;
433 : break;
434 : }
435 : }
436 : rcu_read_unlock();
437 :
438 0 : return overlap;
439 : }
440 :
441 0 : int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
442 : sector_t length)
443 : {
444 0 : sector_t capacity = get_capacity(disk), end;
445 : struct block_device *part;
446 : int ret;
447 :
448 0 : mutex_lock(&disk->open_mutex);
449 0 : if (check_add_overflow(start, length, &end)) {
450 : ret = -EINVAL;
451 : goto out;
452 : }
453 :
454 0 : if (start >= capacity || end > capacity) {
455 : ret = -EINVAL;
456 : goto out;
457 : }
458 :
459 0 : if (!disk_live(disk)) {
460 : ret = -ENXIO;
461 : goto out;
462 : }
463 :
464 0 : if (partition_overlaps(disk, start, length, -1)) {
465 : ret = -EBUSY;
466 : goto out;
467 : }
468 :
469 0 : part = add_partition(disk, partno, start, length,
470 : ADDPART_FLAG_NONE, NULL);
471 : ret = PTR_ERR_OR_ZERO(part);
472 : out:
473 0 : mutex_unlock(&disk->open_mutex);
474 0 : return ret;
475 : }
476 :
477 0 : int bdev_del_partition(struct gendisk *disk, int partno)
478 : {
479 0 : struct block_device *part = NULL;
480 0 : int ret = -ENXIO;
481 :
482 0 : mutex_lock(&disk->open_mutex);
483 0 : part = xa_load(&disk->part_tbl, partno);
484 0 : if (!part)
485 : goto out_unlock;
486 :
487 0 : ret = -EBUSY;
488 0 : if (atomic_read(&part->bd_openers))
489 : goto out_unlock;
490 :
491 0 : delete_partition(part);
492 0 : ret = 0;
493 : out_unlock:
494 0 : mutex_unlock(&disk->open_mutex);
495 0 : return ret;
496 : }
497 :
498 0 : int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start,
499 : sector_t length)
500 : {
501 0 : struct block_device *part = NULL;
502 0 : int ret = -ENXIO;
503 :
504 0 : mutex_lock(&disk->open_mutex);
505 0 : part = xa_load(&disk->part_tbl, partno);
506 0 : if (!part)
507 : goto out_unlock;
508 :
509 0 : ret = -EINVAL;
510 0 : if (start != part->bd_start_sect)
511 : goto out_unlock;
512 :
513 0 : ret = -EBUSY;
514 0 : if (partition_overlaps(disk, start, length, partno))
515 : goto out_unlock;
516 :
517 0 : bdev_set_nr_sectors(part, length);
518 :
519 0 : ret = 0;
520 : out_unlock:
521 0 : mutex_unlock(&disk->open_mutex);
522 0 : return ret;
523 : }
524 :
525 0 : static bool disk_unlock_native_capacity(struct gendisk *disk)
526 : {
527 0 : if (!disk->fops->unlock_native_capacity ||
528 0 : test_and_set_bit(GD_NATIVE_CAPACITY, &disk->state)) {
529 0 : printk(KERN_CONT "truncated\n");
530 0 : return false;
531 : }
532 :
533 0 : printk(KERN_CONT "enabling native capacity\n");
534 0 : disk->fops->unlock_native_capacity(disk);
535 0 : return true;
536 : }
537 :
538 0 : static bool blk_add_partition(struct gendisk *disk,
539 : struct parsed_partitions *state, int p)
540 : {
541 0 : sector_t size = state->parts[p].size;
542 0 : sector_t from = state->parts[p].from;
543 : struct block_device *part;
544 :
545 0 : if (!size)
546 : return true;
547 :
548 0 : if (from >= get_capacity(disk)) {
549 0 : printk(KERN_WARNING
550 : "%s: p%d start %llu is beyond EOD, ",
551 : disk->disk_name, p, (unsigned long long) from);
552 0 : if (disk_unlock_native_capacity(disk))
553 : return false;
554 : return true;
555 : }
556 :
557 0 : if (from + size > get_capacity(disk)) {
558 0 : printk(KERN_WARNING
559 : "%s: p%d size %llu extends beyond EOD, ",
560 : disk->disk_name, p, (unsigned long long) size);
561 :
562 0 : if (disk_unlock_native_capacity(disk))
563 : return false;
564 :
565 : /*
566 : * We can not ignore partitions of broken tables created by for
567 : * example camera firmware, but we limit them to the end of the
568 : * disk to avoid creating invalid block devices.
569 : */
570 0 : size = get_capacity(disk) - from;
571 : }
572 :
573 0 : part = add_partition(disk, p, from, size, state->parts[p].flags,
574 0 : &state->parts[p].info);
575 0 : if (IS_ERR(part) && PTR_ERR(part) != -ENXIO) {
576 0 : printk(KERN_ERR " %s: p%d could not be added: %ld\n",
577 : disk->disk_name, p, -PTR_ERR(part));
578 : return true;
579 : }
580 :
581 : if (IS_BUILTIN(CONFIG_BLK_DEV_MD) &&
582 : (state->parts[p].flags & ADDPART_FLAG_RAID))
583 : md_autodetect_dev(part->bd_dev);
584 :
585 : return true;
586 : }
587 :
588 0 : static int blk_add_partitions(struct gendisk *disk)
589 : {
590 : struct parsed_partitions *state;
591 0 : int ret = -EAGAIN, p;
592 :
593 0 : if (disk->flags & GENHD_FL_NO_PART)
594 : return 0;
595 :
596 0 : if (test_bit(GD_SUPPRESS_PART_SCAN, &disk->state))
597 : return 0;
598 :
599 0 : state = check_partition(disk);
600 0 : if (!state)
601 : return 0;
602 0 : if (IS_ERR(state)) {
603 : /*
604 : * I/O error reading the partition table. If we tried to read
605 : * beyond EOD, retry after unlocking the native capacity.
606 : */
607 0 : if (PTR_ERR(state) == -ENOSPC) {
608 0 : printk(KERN_WARNING "%s: partition table beyond EOD, ",
609 : disk->disk_name);
610 0 : if (disk_unlock_native_capacity(disk))
611 : return -EAGAIN;
612 : }
613 : return -EIO;
614 : }
615 :
616 : /*
617 : * Partitions are not supported on host managed zoned block devices.
618 : */
619 0 : if (disk->queue->limits.zoned == BLK_ZONED_HM) {
620 0 : pr_warn("%s: ignoring partition table on host managed zoned block device\n",
621 : disk->disk_name);
622 0 : ret = 0;
623 0 : goto out_free_state;
624 : }
625 :
626 : /*
627 : * If we read beyond EOD, try unlocking native capacity even if the
628 : * partition table was successfully read as we could be missing some
629 : * partitions.
630 : */
631 0 : if (state->access_beyond_eod) {
632 0 : printk(KERN_WARNING
633 : "%s: partition table partially beyond EOD, ",
634 : disk->disk_name);
635 0 : if (disk_unlock_native_capacity(disk))
636 : goto out_free_state;
637 : }
638 :
639 : /* tell userspace that the media / partition table may have changed */
640 0 : kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
641 :
642 0 : for (p = 1; p < state->limit; p++)
643 0 : if (!blk_add_partition(disk, state, p))
644 : goto out_free_state;
645 :
646 : ret = 0;
647 : out_free_state:
648 0 : free_partitions(state);
649 0 : return ret;
650 : }
651 :
652 0 : int bdev_disk_changed(struct gendisk *disk, bool invalidate)
653 : {
654 : struct block_device *part;
655 : unsigned long idx;
656 0 : int ret = 0;
657 :
658 : lockdep_assert_held(&disk->open_mutex);
659 :
660 0 : if (!disk_live(disk))
661 : return -ENXIO;
662 :
663 : rescan:
664 0 : if (disk->open_partitions)
665 : return -EBUSY;
666 0 : sync_blockdev(disk->part0);
667 0 : invalidate_bdev(disk->part0);
668 :
669 0 : xa_for_each_start(&disk->part_tbl, idx, part, 1)
670 0 : delete_partition(part);
671 0 : clear_bit(GD_NEED_PART_SCAN, &disk->state);
672 :
673 : /*
674 : * Historically we only set the capacity to zero for devices that
675 : * support partitions (independ of actually having partitions created).
676 : * Doing that is rather inconsistent, but changing it broke legacy
677 : * udisks polling for legacy ide-cdrom devices. Use the crude check
678 : * below to get the sane behavior for most device while not breaking
679 : * userspace for this particular setup.
680 : */
681 0 : if (invalidate) {
682 0 : if (!(disk->flags & GENHD_FL_NO_PART) ||
683 : !(disk->flags & GENHD_FL_REMOVABLE))
684 0 : set_capacity(disk, 0);
685 : }
686 :
687 0 : if (get_capacity(disk)) {
688 0 : ret = blk_add_partitions(disk);
689 0 : if (ret == -EAGAIN)
690 : goto rescan;
691 0 : } else if (invalidate) {
692 : /*
693 : * Tell userspace that the media / partition table may have
694 : * changed.
695 : */
696 0 : kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
697 : }
698 :
699 : return ret;
700 : }
701 : /*
702 : * Only exported for loop and dasd for historic reasons. Don't use in new
703 : * code!
704 : */
705 : EXPORT_SYMBOL_GPL(bdev_disk_changed);
706 :
707 0 : void *read_part_sector(struct parsed_partitions *state, sector_t n, Sector *p)
708 : {
709 0 : struct address_space *mapping = state->disk->part0->bd_inode->i_mapping;
710 : struct folio *folio;
711 :
712 0 : if (n >= get_capacity(state->disk)) {
713 0 : state->access_beyond_eod = true;
714 0 : goto out;
715 : }
716 :
717 0 : folio = read_mapping_folio(mapping, n >> PAGE_SECTORS_SHIFT, NULL);
718 0 : if (IS_ERR(folio))
719 : goto out;
720 :
721 0 : p->v = folio;
722 0 : return folio_address(folio) + offset_in_folio(folio, n * SECTOR_SIZE);
723 : out:
724 0 : p->v = NULL;
725 0 : return NULL;
726 : }
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