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 (*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 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 : 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 : static void delete_partition(struct block_device *part)
267 : {
268 : lockdep_assert_held(&part->bd_disk->open_mutex);
269 :
270 0 : fsync_bdev(part);
271 0 : __invalidate_device(part, true);
272 :
273 0 : xa_erase(&part->bd_disk->part_tbl, part->bd_partno);
274 0 : kobject_put(part->bd_holder_dir);
275 0 : 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 0 : remove_inode_hash(part->bd_inode);
282 :
283 0 : put_device(&part->bd_device);
284 0 : }
285 :
286 0 : static ssize_t whole_disk_show(struct device *dev,
287 : struct device_attribute *attr, char *buf)
288 : {
289 0 : 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 0 : 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 0 : dev_t devt = MKDEV(0, 0);
302 0 : 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 0 : 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 0 : switch (disk->queue->limits.zoned) {
318 : case BLK_ZONED_HM:
319 0 : pr_warn("%s: partitions not supported on host managed zoned block device\n",
320 : disk->disk_name);
321 0 : return ERR_PTR(-ENXIO);
322 : case BLK_ZONED_HA:
323 0 : pr_info("%s: disabling host aware zoned block device support due to partitions\n",
324 : disk->disk_name);
325 0 : disk_set_zoned(disk, BLK_ZONED_NONE);
326 0 : break;
327 : case BLK_ZONED_NONE:
328 : break;
329 : }
330 :
331 0 : 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 0 : get_device(disk_to_dev(disk));
336 :
337 0 : err = -ENOMEM;
338 0 : bdev = bdev_alloc(disk, partno);
339 0 : if (!bdev)
340 : goto out_put_disk;
341 :
342 0 : bdev->bd_start_sect = start;
343 0 : bdev_set_nr_sectors(bdev, len);
344 :
345 0 : pdev = &bdev->bd_device;
346 0 : dname = dev_name(ddev);
347 0 : if (isdigit(dname[strlen(dname) - 1]))
348 0 : dev_set_name(pdev, "%sp%d", dname, partno);
349 : else
350 0 : dev_set_name(pdev, "%s%d", dname, partno);
351 :
352 0 : device_initialize(pdev);
353 0 : pdev->class = &block_class;
354 0 : pdev->type = &part_type;
355 0 : pdev->parent = ddev;
356 :
357 : /* in consecutive minor range? */
358 0 : if (bdev->bd_partno < disk->minors) {
359 0 : devt = MKDEV(disk->major, disk->first_minor + bdev->bd_partno);
360 : } else {
361 0 : err = blk_alloc_ext_minor();
362 0 : if (err < 0)
363 : goto out_put;
364 0 : devt = MKDEV(BLOCK_EXT_MAJOR, err);
365 : }
366 0 : pdev->devt = devt;
367 :
368 0 : if (info) {
369 0 : err = -ENOMEM;
370 0 : bdev->bd_meta_info = kmemdup(info, sizeof(*info), GFP_KERNEL);
371 0 : if (!bdev->bd_meta_info)
372 : goto out_put;
373 : }
374 :
375 : /* delay uevent until 'holders' subdir is created */
376 0 : dev_set_uevent_suppress(pdev, 1);
377 0 : err = device_add(pdev);
378 0 : if (err)
379 : goto out_put;
380 :
381 0 : err = -ENOMEM;
382 0 : bdev->bd_holder_dir = kobject_create_and_add("holders", &pdev->kobj);
383 0 : if (!bdev->bd_holder_dir)
384 : goto out_del;
385 :
386 0 : dev_set_uevent_suppress(pdev, 0);
387 0 : if (flags & ADDPART_FLAG_WHOLEDISK) {
388 0 : err = device_create_file(pdev, &dev_attr_whole_disk);
389 0 : if (err)
390 : goto out_del;
391 : }
392 :
393 : /* everything is up and running, commence */
394 0 : err = xa_insert(&disk->part_tbl, partno, bdev, GFP_KERNEL);
395 0 : if (err)
396 : goto out_del;
397 0 : bdev_add(bdev, devt);
398 :
399 : /* suppress uevent if the disk suppresses it */
400 0 : if (!dev_get_uevent_suppress(ddev))
401 0 : kobject_uevent(&pdev->kobj, KOBJ_ADD);
402 : return bdev;
403 :
404 : out_del:
405 0 : kobject_put(bdev->bd_holder_dir);
406 0 : device_del(pdev);
407 : out_put:
408 0 : put_device(pdev);
409 0 : return ERR_PTR(err);
410 : out_put_disk:
411 0 : put_disk(disk);
412 0 : return ERR_PTR(err);
413 : }
414 :
415 0 : static bool partition_overlaps(struct gendisk *disk, sector_t start,
416 : sector_t length, int skip_partno)
417 : {
418 : struct block_device *part;
419 0 : bool overlap = false;
420 : unsigned long idx;
421 :
422 : rcu_read_lock();
423 0 : xa_for_each_start(&disk->part_tbl, idx, part, 1) {
424 0 : if (part->bd_partno != skip_partno &&
425 0 : start < part->bd_start_sect + bdev_nr_sectors(part) &&
426 0 : start + length > part->bd_start_sect) {
427 : overlap = true;
428 : break;
429 : }
430 : }
431 : rcu_read_unlock();
432 :
433 0 : return overlap;
434 : }
435 :
436 0 : 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 0 : mutex_lock(&disk->open_mutex);
443 0 : if (!disk_live(disk)) {
444 : ret = -ENXIO;
445 : goto out;
446 : }
447 :
448 0 : if (partition_overlaps(disk, start, length, -1)) {
449 : ret = -EBUSY;
450 : goto out;
451 : }
452 :
453 0 : part = add_partition(disk, partno, start, length,
454 : ADDPART_FLAG_NONE, NULL);
455 : ret = PTR_ERR_OR_ZERO(part);
456 : out:
457 0 : mutex_unlock(&disk->open_mutex);
458 0 : return ret;
459 : }
460 :
461 0 : int bdev_del_partition(struct gendisk *disk, int partno)
462 : {
463 0 : struct block_device *part = NULL;
464 0 : int ret = -ENXIO;
465 :
466 0 : mutex_lock(&disk->open_mutex);
467 0 : part = xa_load(&disk->part_tbl, partno);
468 0 : if (!part)
469 : goto out_unlock;
470 :
471 0 : ret = -EBUSY;
472 0 : if (atomic_read(&part->bd_openers))
473 : goto out_unlock;
474 :
475 0 : delete_partition(part);
476 0 : ret = 0;
477 : out_unlock:
478 0 : mutex_unlock(&disk->open_mutex);
479 0 : return ret;
480 : }
481 :
482 0 : int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start,
483 : sector_t length)
484 : {
485 0 : struct block_device *part = NULL;
486 0 : int ret = -ENXIO;
487 :
488 0 : mutex_lock(&disk->open_mutex);
489 0 : part = xa_load(&disk->part_tbl, partno);
490 0 : if (!part)
491 : goto out_unlock;
492 :
493 0 : ret = -EINVAL;
494 0 : if (start != part->bd_start_sect)
495 : goto out_unlock;
496 :
497 0 : ret = -EBUSY;
498 0 : if (partition_overlaps(disk, start, length, partno))
499 : goto out_unlock;
500 :
501 0 : bdev_set_nr_sectors(part, length);
502 :
503 0 : ret = 0;
504 : out_unlock:
505 0 : mutex_unlock(&disk->open_mutex);
506 0 : return ret;
507 : }
508 :
509 0 : static bool disk_unlock_native_capacity(struct gendisk *disk)
510 : {
511 0 : if (!disk->fops->unlock_native_capacity ||
512 0 : test_and_set_bit(GD_NATIVE_CAPACITY, &disk->state)) {
513 0 : printk(KERN_CONT "truncated\n");
514 0 : return false;
515 : }
516 :
517 0 : printk(KERN_CONT "enabling native capacity\n");
518 0 : disk->fops->unlock_native_capacity(disk);
519 0 : return true;
520 : }
521 :
522 0 : 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 0 : xa_for_each_start(&disk->part_tbl, idx, part, 1)
530 0 : delete_partition(part);
531 0 : }
532 :
533 0 : static bool blk_add_partition(struct gendisk *disk,
534 : struct parsed_partitions *state, int p)
535 : {
536 0 : sector_t size = state->parts[p].size;
537 0 : sector_t from = state->parts[p].from;
538 : struct block_device *part;
539 :
540 0 : if (!size)
541 : return true;
542 :
543 0 : if (from >= get_capacity(disk)) {
544 0 : printk(KERN_WARNING
545 : "%s: p%d start %llu is beyond EOD, ",
546 : disk->disk_name, p, (unsigned long long) from);
547 0 : if (disk_unlock_native_capacity(disk))
548 : return false;
549 : return true;
550 : }
551 :
552 0 : if (from + size > get_capacity(disk)) {
553 0 : printk(KERN_WARNING
554 : "%s: p%d size %llu extends beyond EOD, ",
555 : disk->disk_name, p, (unsigned long long) size);
556 :
557 0 : 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 0 : size = get_capacity(disk) - from;
566 : }
567 :
568 0 : part = add_partition(disk, p, from, size, state->parts[p].flags,
569 0 : &state->parts[p].info);
570 0 : if (IS_ERR(part) && PTR_ERR(part) != -ENXIO) {
571 0 : 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 0 : static int blk_add_partitions(struct gendisk *disk)
584 : {
585 : struct parsed_partitions *state;
586 0 : int ret = -EAGAIN, p;
587 :
588 0 : if (disk->flags & GENHD_FL_NO_PART)
589 : return 0;
590 :
591 0 : if (test_bit(GD_SUPPRESS_PART_SCAN, &disk->state))
592 : return 0;
593 :
594 0 : state = check_partition(disk);
595 0 : if (!state)
596 : return 0;
597 0 : 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 0 : if (PTR_ERR(state) == -ENOSPC) {
603 0 : printk(KERN_WARNING "%s: partition table beyond EOD, ",
604 : disk->disk_name);
605 0 : 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 0 : if (disk->queue->limits.zoned == BLK_ZONED_HM) {
615 0 : pr_warn("%s: ignoring partition table on host managed zoned block device\n",
616 : disk->disk_name);
617 0 : ret = 0;
618 0 : 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 0 : if (state->access_beyond_eod) {
627 0 : printk(KERN_WARNING
628 : "%s: partition table partially beyond EOD, ",
629 : disk->disk_name);
630 0 : 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 0 : kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
636 :
637 0 : for (p = 1; p < state->limit; p++)
638 0 : if (!blk_add_partition(disk, state, p))
639 : goto out_free_state;
640 :
641 : ret = 0;
642 : out_free_state:
643 0 : free_partitions(state);
644 0 : return ret;
645 : }
646 :
647 0 : int bdev_disk_changed(struct gendisk *disk, bool invalidate)
648 : {
649 0 : int ret = 0;
650 :
651 : lockdep_assert_held(&disk->open_mutex);
652 :
653 0 : if (!disk_live(disk))
654 : return -ENXIO;
655 :
656 : rescan:
657 0 : if (disk->open_partitions)
658 : return -EBUSY;
659 0 : sync_blockdev(disk->part0);
660 0 : invalidate_bdev(disk->part0);
661 0 : blk_drop_partitions(disk);
662 :
663 0 : 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 0 : if (invalidate) {
674 0 : if (!(disk->flags & GENHD_FL_NO_PART) ||
675 : !(disk->flags & GENHD_FL_REMOVABLE))
676 0 : set_capacity(disk, 0);
677 : }
678 :
679 0 : if (get_capacity(disk)) {
680 0 : ret = blk_add_partitions(disk);
681 0 : if (ret == -EAGAIN)
682 : goto rescan;
683 0 : } else if (invalidate) {
684 : /*
685 : * Tell userspace that the media / partition table may have
686 : * changed.
687 : */
688 0 : 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 0 : void *read_part_sector(struct parsed_partitions *state, sector_t n, Sector *p)
700 : {
701 0 : struct address_space *mapping = state->disk->part0->bd_inode->i_mapping;
702 : struct folio *folio;
703 :
704 0 : if (n >= get_capacity(state->disk)) {
705 0 : state->access_beyond_eod = true;
706 0 : goto out;
707 : }
708 :
709 0 : folio = read_mapping_folio(mapping, n >> PAGE_SECTORS_SHIFT, NULL);
710 0 : if (IS_ERR(folio))
711 : goto out;
712 :
713 0 : p->v = folio;
714 0 : return folio_address(folio) + offset_in_folio(folio, n * SECTOR_SIZE);
715 : out:
716 0 : p->v = NULL;
717 0 : return NULL;
718 : }
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