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 : static void bdev_set_nr_sectors(struct block_device *bdev, sector_t sectors)
89 : {
90 0 : spin_lock(&bdev->bd_size_lock);
91 0 : i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT);
92 0 : bdev->bd_nr_sectors = sectors;
93 0 : spin_unlock(&bdev->bd_size_lock);
94 : }
95 :
96 0 : static struct parsed_partitions *allocate_partitions(struct gendisk *hd)
97 : {
98 : struct parsed_partitions *state;
99 0 : int nr = DISK_MAX_PARTS;
100 :
101 0 : state = kzalloc(sizeof(*state), GFP_KERNEL);
102 0 : if (!state)
103 : return NULL;
104 :
105 0 : state->parts = vzalloc(array_size(nr, sizeof(state->parts[0])));
106 0 : if (!state->parts) {
107 0 : kfree(state);
108 : return NULL;
109 : }
110 :
111 0 : state->limit = nr;
112 :
113 : return state;
114 : }
115 :
116 : static void free_partitions(struct parsed_partitions *state)
117 : {
118 0 : vfree(state->parts);
119 0 : kfree(state);
120 : }
121 :
122 0 : static struct parsed_partitions *check_partition(struct gendisk *hd)
123 : {
124 : struct parsed_partitions *state;
125 : int i, res, err;
126 :
127 0 : state = allocate_partitions(hd);
128 0 : if (!state)
129 : return NULL;
130 0 : state->pp_buf = (char *)__get_free_page(GFP_KERNEL);
131 0 : if (!state->pp_buf) {
132 0 : free_partitions(state);
133 0 : return NULL;
134 : }
135 0 : state->pp_buf[0] = '\0';
136 :
137 0 : state->disk = hd;
138 0 : snprintf(state->name, BDEVNAME_SIZE, "%s", hd->disk_name);
139 0 : snprintf(state->pp_buf, PAGE_SIZE, " %s:", state->name);
140 0 : if (isdigit(state->name[strlen(state->name)-1]))
141 0 : sprintf(state->name, "p");
142 :
143 : i = res = err = 0;
144 0 : while (!res && check_part[i]) {
145 0 : memset(state->parts, 0, state->limit * sizeof(state->parts[0]));
146 0 : res = check_part[i++](state);
147 0 : if (res < 0) {
148 : /*
149 : * We have hit an I/O error which we don't report now.
150 : * But record it, and let the others do their job.
151 : */
152 0 : err = res;
153 0 : res = 0;
154 : }
155 :
156 : }
157 0 : if (res > 0) {
158 0 : printk(KERN_INFO "%s", state->pp_buf);
159 :
160 0 : free_page((unsigned long)state->pp_buf);
161 0 : return state;
162 : }
163 0 : if (state->access_beyond_eod)
164 0 : err = -ENOSPC;
165 : /*
166 : * The partition is unrecognized. So report I/O errors if there were any
167 : */
168 0 : if (err)
169 0 : res = err;
170 0 : if (res) {
171 0 : strlcat(state->pp_buf,
172 : " unable to read partition table\n", PAGE_SIZE);
173 0 : printk(KERN_INFO "%s", state->pp_buf);
174 : }
175 :
176 0 : free_page((unsigned long)state->pp_buf);
177 0 : free_partitions(state);
178 0 : return ERR_PTR(res);
179 : }
180 :
181 0 : static ssize_t part_partition_show(struct device *dev,
182 : struct device_attribute *attr, char *buf)
183 : {
184 0 : return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_partno);
185 : }
186 :
187 0 : static ssize_t part_start_show(struct device *dev,
188 : struct device_attribute *attr, char *buf)
189 : {
190 0 : return sprintf(buf, "%llu\n", dev_to_bdev(dev)->bd_start_sect);
191 : }
192 :
193 0 : static ssize_t part_ro_show(struct device *dev,
194 : struct device_attribute *attr, char *buf)
195 : {
196 0 : return sprintf(buf, "%d\n", bdev_read_only(dev_to_bdev(dev)));
197 : }
198 :
199 0 : static ssize_t part_alignment_offset_show(struct device *dev,
200 : struct device_attribute *attr, char *buf)
201 : {
202 0 : return sprintf(buf, "%u\n", bdev_alignment_offset(dev_to_bdev(dev)));
203 : }
204 :
205 0 : static ssize_t part_discard_alignment_show(struct device *dev,
206 : struct device_attribute *attr, char *buf)
207 : {
208 0 : return sprintf(buf, "%u\n", bdev_discard_alignment(dev_to_bdev(dev)));
209 : }
210 :
211 : static DEVICE_ATTR(partition, 0444, part_partition_show, NULL);
212 : static DEVICE_ATTR(start, 0444, part_start_show, NULL);
213 : static DEVICE_ATTR(size, 0444, part_size_show, NULL);
214 : static DEVICE_ATTR(ro, 0444, part_ro_show, NULL);
215 : static DEVICE_ATTR(alignment_offset, 0444, part_alignment_offset_show, NULL);
216 : static DEVICE_ATTR(discard_alignment, 0444, part_discard_alignment_show, NULL);
217 : static DEVICE_ATTR(stat, 0444, part_stat_show, NULL);
218 : static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL);
219 : #ifdef CONFIG_FAIL_MAKE_REQUEST
220 : static struct device_attribute dev_attr_fail =
221 : __ATTR(make-it-fail, 0644, part_fail_show, part_fail_store);
222 : #endif
223 :
224 : static struct attribute *part_attrs[] = {
225 : &dev_attr_partition.attr,
226 : &dev_attr_start.attr,
227 : &dev_attr_size.attr,
228 : &dev_attr_ro.attr,
229 : &dev_attr_alignment_offset.attr,
230 : &dev_attr_discard_alignment.attr,
231 : &dev_attr_stat.attr,
232 : &dev_attr_inflight.attr,
233 : #ifdef CONFIG_FAIL_MAKE_REQUEST
234 : &dev_attr_fail.attr,
235 : #endif
236 : NULL
237 : };
238 :
239 : static struct attribute_group part_attr_group = {
240 : .attrs = part_attrs,
241 : };
242 :
243 : static const struct attribute_group *part_attr_groups[] = {
244 : &part_attr_group,
245 : #ifdef CONFIG_BLK_DEV_IO_TRACE
246 : &blk_trace_attr_group,
247 : #endif
248 : NULL
249 : };
250 :
251 0 : static void part_release(struct device *dev)
252 : {
253 0 : put_disk(dev_to_bdev(dev)->bd_disk);
254 0 : iput(dev_to_bdev(dev)->bd_inode);
255 0 : }
256 :
257 0 : static int part_uevent(const struct device *dev, struct kobj_uevent_env *env)
258 : {
259 0 : const struct block_device *part = dev_to_bdev(dev);
260 :
261 0 : add_uevent_var(env, "PARTN=%u", part->bd_partno);
262 0 : if (part->bd_meta_info && part->bd_meta_info->volname[0])
263 0 : add_uevent_var(env, "PARTNAME=%s", part->bd_meta_info->volname);
264 0 : return 0;
265 : }
266 :
267 : struct device_type part_type = {
268 : .name = "partition",
269 : .groups = part_attr_groups,
270 : .release = part_release,
271 : .uevent = part_uevent,
272 : };
273 :
274 0 : static void delete_partition(struct block_device *part)
275 : {
276 : lockdep_assert_held(&part->bd_disk->open_mutex);
277 :
278 0 : fsync_bdev(part);
279 0 : __invalidate_device(part, true);
280 :
281 0 : xa_erase(&part->bd_disk->part_tbl, part->bd_partno);
282 0 : kobject_put(part->bd_holder_dir);
283 0 : device_del(&part->bd_device);
284 :
285 : /*
286 : * Remove the block device from the inode hash, so that it cannot be
287 : * looked up any more even when openers still hold references.
288 : */
289 0 : remove_inode_hash(part->bd_inode);
290 :
291 0 : put_device(&part->bd_device);
292 0 : }
293 :
294 0 : static ssize_t whole_disk_show(struct device *dev,
295 : struct device_attribute *attr, char *buf)
296 : {
297 0 : return 0;
298 : }
299 : static DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL);
300 :
301 : /*
302 : * Must be called either with open_mutex held, before a disk can be opened or
303 : * after all disk users are gone.
304 : */
305 0 : static struct block_device *add_partition(struct gendisk *disk, int partno,
306 : sector_t start, sector_t len, int flags,
307 : struct partition_meta_info *info)
308 : {
309 0 : dev_t devt = MKDEV(0, 0);
310 0 : struct device *ddev = disk_to_dev(disk);
311 : struct device *pdev;
312 : struct block_device *bdev;
313 : const char *dname;
314 : int err;
315 :
316 : lockdep_assert_held(&disk->open_mutex);
317 :
318 0 : if (partno >= DISK_MAX_PARTS)
319 : return ERR_PTR(-EINVAL);
320 :
321 : /*
322 : * Partitions are not supported on zoned block devices that are used as
323 : * such.
324 : */
325 0 : switch (disk->queue->limits.zoned) {
326 : case BLK_ZONED_HM:
327 0 : pr_warn("%s: partitions not supported on host managed zoned block device\n",
328 : disk->disk_name);
329 0 : return ERR_PTR(-ENXIO);
330 : case BLK_ZONED_HA:
331 0 : pr_info("%s: disabling host aware zoned block device support due to partitions\n",
332 : disk->disk_name);
333 0 : disk_set_zoned(disk, BLK_ZONED_NONE);
334 0 : break;
335 : case BLK_ZONED_NONE:
336 : break;
337 : }
338 :
339 0 : if (xa_load(&disk->part_tbl, partno))
340 : return ERR_PTR(-EBUSY);
341 :
342 : /* ensure we always have a reference to the whole disk */
343 0 : get_device(disk_to_dev(disk));
344 :
345 0 : err = -ENOMEM;
346 0 : bdev = bdev_alloc(disk, partno);
347 0 : if (!bdev)
348 : goto out_put_disk;
349 :
350 0 : bdev->bd_start_sect = start;
351 0 : bdev_set_nr_sectors(bdev, len);
352 :
353 0 : pdev = &bdev->bd_device;
354 0 : dname = dev_name(ddev);
355 0 : if (isdigit(dname[strlen(dname) - 1]))
356 0 : dev_set_name(pdev, "%sp%d", dname, partno);
357 : else
358 0 : dev_set_name(pdev, "%s%d", dname, partno);
359 :
360 0 : device_initialize(pdev);
361 0 : pdev->class = &block_class;
362 0 : pdev->type = &part_type;
363 0 : pdev->parent = ddev;
364 :
365 : /* in consecutive minor range? */
366 0 : if (bdev->bd_partno < disk->minors) {
367 0 : devt = MKDEV(disk->major, disk->first_minor + bdev->bd_partno);
368 : } else {
369 0 : err = blk_alloc_ext_minor();
370 0 : if (err < 0)
371 : goto out_put;
372 0 : devt = MKDEV(BLOCK_EXT_MAJOR, err);
373 : }
374 0 : pdev->devt = devt;
375 :
376 0 : if (info) {
377 0 : err = -ENOMEM;
378 0 : bdev->bd_meta_info = kmemdup(info, sizeof(*info), GFP_KERNEL);
379 0 : if (!bdev->bd_meta_info)
380 : goto out_put;
381 : }
382 :
383 : /* delay uevent until 'holders' subdir is created */
384 0 : dev_set_uevent_suppress(pdev, 1);
385 0 : err = device_add(pdev);
386 0 : if (err)
387 : goto out_put;
388 :
389 0 : err = -ENOMEM;
390 0 : bdev->bd_holder_dir = kobject_create_and_add("holders", &pdev->kobj);
391 0 : if (!bdev->bd_holder_dir)
392 : goto out_del;
393 :
394 0 : dev_set_uevent_suppress(pdev, 0);
395 0 : if (flags & ADDPART_FLAG_WHOLEDISK) {
396 0 : err = device_create_file(pdev, &dev_attr_whole_disk);
397 0 : if (err)
398 : goto out_del;
399 : }
400 :
401 : /* everything is up and running, commence */
402 0 : err = xa_insert(&disk->part_tbl, partno, bdev, GFP_KERNEL);
403 0 : if (err)
404 : goto out_del;
405 0 : bdev_add(bdev, devt);
406 :
407 : /* suppress uevent if the disk suppresses it */
408 0 : if (!dev_get_uevent_suppress(ddev))
409 0 : kobject_uevent(&pdev->kobj, KOBJ_ADD);
410 : return bdev;
411 :
412 : out_del:
413 0 : kobject_put(bdev->bd_holder_dir);
414 0 : device_del(pdev);
415 : out_put:
416 0 : put_device(pdev);
417 0 : return ERR_PTR(err);
418 : out_put_disk:
419 0 : put_disk(disk);
420 0 : return ERR_PTR(err);
421 : }
422 :
423 0 : static bool partition_overlaps(struct gendisk *disk, sector_t start,
424 : sector_t length, int skip_partno)
425 : {
426 : struct block_device *part;
427 0 : bool overlap = false;
428 : unsigned long idx;
429 :
430 : rcu_read_lock();
431 0 : xa_for_each_start(&disk->part_tbl, idx, part, 1) {
432 0 : if (part->bd_partno != skip_partno &&
433 0 : start < part->bd_start_sect + bdev_nr_sectors(part) &&
434 0 : start + length > part->bd_start_sect) {
435 : overlap = true;
436 : break;
437 : }
438 : }
439 : rcu_read_unlock();
440 :
441 0 : return overlap;
442 : }
443 :
444 0 : int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
445 : sector_t length)
446 : {
447 : struct block_device *part;
448 : int ret;
449 :
450 0 : mutex_lock(&disk->open_mutex);
451 0 : if (!disk_live(disk)) {
452 : ret = -ENXIO;
453 : goto out;
454 : }
455 :
456 0 : if (partition_overlaps(disk, start, length, -1)) {
457 : ret = -EBUSY;
458 : goto out;
459 : }
460 :
461 0 : part = add_partition(disk, partno, start, length,
462 : ADDPART_FLAG_NONE, NULL);
463 : ret = PTR_ERR_OR_ZERO(part);
464 : out:
465 0 : mutex_unlock(&disk->open_mutex);
466 0 : return ret;
467 : }
468 :
469 0 : int bdev_del_partition(struct gendisk *disk, int partno)
470 : {
471 0 : struct block_device *part = NULL;
472 0 : int ret = -ENXIO;
473 :
474 0 : mutex_lock(&disk->open_mutex);
475 0 : part = xa_load(&disk->part_tbl, partno);
476 0 : if (!part)
477 : goto out_unlock;
478 :
479 0 : ret = -EBUSY;
480 0 : if (atomic_read(&part->bd_openers))
481 : goto out_unlock;
482 :
483 0 : delete_partition(part);
484 0 : ret = 0;
485 : out_unlock:
486 0 : mutex_unlock(&disk->open_mutex);
487 0 : return ret;
488 : }
489 :
490 0 : int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start,
491 : sector_t length)
492 : {
493 0 : struct block_device *part = NULL;
494 0 : int ret = -ENXIO;
495 :
496 0 : mutex_lock(&disk->open_mutex);
497 0 : part = xa_load(&disk->part_tbl, partno);
498 0 : if (!part)
499 : goto out_unlock;
500 :
501 0 : ret = -EINVAL;
502 0 : if (start != part->bd_start_sect)
503 : goto out_unlock;
504 :
505 0 : ret = -EBUSY;
506 0 : if (partition_overlaps(disk, start, length, partno))
507 : goto out_unlock;
508 :
509 0 : bdev_set_nr_sectors(part, length);
510 :
511 0 : ret = 0;
512 : out_unlock:
513 0 : mutex_unlock(&disk->open_mutex);
514 0 : return ret;
515 : }
516 :
517 0 : static bool disk_unlock_native_capacity(struct gendisk *disk)
518 : {
519 0 : if (!disk->fops->unlock_native_capacity ||
520 0 : test_and_set_bit(GD_NATIVE_CAPACITY, &disk->state)) {
521 0 : printk(KERN_CONT "truncated\n");
522 0 : return false;
523 : }
524 :
525 0 : printk(KERN_CONT "enabling native capacity\n");
526 0 : disk->fops->unlock_native_capacity(disk);
527 0 : return true;
528 : }
529 :
530 0 : void blk_drop_partitions(struct gendisk *disk)
531 : {
532 : struct block_device *part;
533 : unsigned long idx;
534 :
535 : lockdep_assert_held(&disk->open_mutex);
536 :
537 0 : xa_for_each_start(&disk->part_tbl, idx, part, 1)
538 0 : delete_partition(part);
539 0 : }
540 :
541 0 : static bool blk_add_partition(struct gendisk *disk,
542 : struct parsed_partitions *state, int p)
543 : {
544 0 : sector_t size = state->parts[p].size;
545 0 : sector_t from = state->parts[p].from;
546 : struct block_device *part;
547 :
548 0 : if (!size)
549 : return true;
550 :
551 0 : if (from >= get_capacity(disk)) {
552 0 : printk(KERN_WARNING
553 : "%s: p%d start %llu is beyond EOD, ",
554 : disk->disk_name, p, (unsigned long long) from);
555 0 : if (disk_unlock_native_capacity(disk))
556 : return false;
557 : return true;
558 : }
559 :
560 0 : if (from + size > get_capacity(disk)) {
561 0 : printk(KERN_WARNING
562 : "%s: p%d size %llu extends beyond EOD, ",
563 : disk->disk_name, p, (unsigned long long) size);
564 :
565 0 : if (disk_unlock_native_capacity(disk))
566 : return false;
567 :
568 : /*
569 : * We can not ignore partitions of broken tables created by for
570 : * example camera firmware, but we limit them to the end of the
571 : * disk to avoid creating invalid block devices.
572 : */
573 0 : size = get_capacity(disk) - from;
574 : }
575 :
576 0 : part = add_partition(disk, p, from, size, state->parts[p].flags,
577 0 : &state->parts[p].info);
578 0 : if (IS_ERR(part) && PTR_ERR(part) != -ENXIO) {
579 0 : printk(KERN_ERR " %s: p%d could not be added: %ld\n",
580 : disk->disk_name, p, -PTR_ERR(part));
581 : return true;
582 : }
583 :
584 : if (IS_BUILTIN(CONFIG_BLK_DEV_MD) &&
585 : (state->parts[p].flags & ADDPART_FLAG_RAID))
586 : md_autodetect_dev(part->bd_dev);
587 :
588 : return true;
589 : }
590 :
591 0 : static int blk_add_partitions(struct gendisk *disk)
592 : {
593 : struct parsed_partitions *state;
594 0 : int ret = -EAGAIN, p;
595 :
596 0 : if (disk->flags & GENHD_FL_NO_PART)
597 : return 0;
598 :
599 0 : if (test_bit(GD_SUPPRESS_PART_SCAN, &disk->state))
600 : return 0;
601 :
602 0 : state = check_partition(disk);
603 0 : if (!state)
604 : return 0;
605 0 : if (IS_ERR(state)) {
606 : /*
607 : * I/O error reading the partition table. If we tried to read
608 : * beyond EOD, retry after unlocking the native capacity.
609 : */
610 0 : if (PTR_ERR(state) == -ENOSPC) {
611 0 : printk(KERN_WARNING "%s: partition table beyond EOD, ",
612 : disk->disk_name);
613 0 : if (disk_unlock_native_capacity(disk))
614 : return -EAGAIN;
615 : }
616 : return -EIO;
617 : }
618 :
619 : /*
620 : * Partitions are not supported on host managed zoned block devices.
621 : */
622 0 : if (disk->queue->limits.zoned == BLK_ZONED_HM) {
623 0 : pr_warn("%s: ignoring partition table on host managed zoned block device\n",
624 : disk->disk_name);
625 0 : ret = 0;
626 0 : goto out_free_state;
627 : }
628 :
629 : /*
630 : * If we read beyond EOD, try unlocking native capacity even if the
631 : * partition table was successfully read as we could be missing some
632 : * partitions.
633 : */
634 0 : if (state->access_beyond_eod) {
635 0 : printk(KERN_WARNING
636 : "%s: partition table partially beyond EOD, ",
637 : disk->disk_name);
638 0 : if (disk_unlock_native_capacity(disk))
639 : goto out_free_state;
640 : }
641 :
642 : /* tell userspace that the media / partition table may have changed */
643 0 : kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
644 :
645 0 : for (p = 1; p < state->limit; p++)
646 0 : if (!blk_add_partition(disk, state, p))
647 : goto out_free_state;
648 :
649 : ret = 0;
650 : out_free_state:
651 0 : free_partitions(state);
652 0 : return ret;
653 : }
654 :
655 0 : int bdev_disk_changed(struct gendisk *disk, bool invalidate)
656 : {
657 0 : int ret = 0;
658 :
659 : lockdep_assert_held(&disk->open_mutex);
660 :
661 0 : if (!disk_live(disk))
662 : return -ENXIO;
663 :
664 : rescan:
665 0 : if (disk->open_partitions)
666 : return -EBUSY;
667 0 : sync_blockdev(disk->part0);
668 0 : invalidate_bdev(disk->part0);
669 0 : blk_drop_partitions(disk);
670 :
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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