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/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 0 : spin_lock(&bdev->bd_size_lock);
92 0 : i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT);
93 0 : bdev->bd_nr_sectors = sectors;
94 0 : spin_unlock(&bdev->bd_size_lock);
95 : }
96 :
97 0 : static struct parsed_partitions *allocate_partitions(struct gendisk *hd)
98 : {
99 : struct parsed_partitions *state;
100 0 : int nr = DISK_MAX_PARTS;
101 :
102 0 : state = kzalloc(sizeof(*state), GFP_KERNEL);
103 0 : if (!state)
104 : return NULL;
105 :
106 0 : state->parts = vzalloc(array_size(nr, sizeof(state->parts[0])));
107 0 : if (!state->parts) {
108 0 : kfree(state);
109 : return NULL;
110 : }
111 :
112 0 : state->limit = nr;
113 :
114 : return state;
115 : }
116 :
117 : static void free_partitions(struct parsed_partitions *state)
118 : {
119 0 : vfree(state->parts);
120 0 : kfree(state);
121 : }
122 :
123 0 : static struct parsed_partitions *check_partition(struct gendisk *hd)
124 : {
125 : struct parsed_partitions *state;
126 : int i, res, err;
127 :
128 0 : state = allocate_partitions(hd);
129 0 : if (!state)
130 : return NULL;
131 0 : state->pp_buf = (char *)__get_free_page(GFP_KERNEL);
132 0 : if (!state->pp_buf) {
133 0 : free_partitions(state);
134 0 : return NULL;
135 : }
136 0 : state->pp_buf[0] = '\0';
137 :
138 0 : state->disk = hd;
139 0 : snprintf(state->name, BDEVNAME_SIZE, "%s", hd->disk_name);
140 0 : snprintf(state->pp_buf, PAGE_SIZE, " %s:", state->name);
141 0 : if (isdigit(state->name[strlen(state->name)-1]))
142 0 : sprintf(state->name, "p");
143 :
144 : i = res = err = 0;
145 0 : while (!res && check_part[i]) {
146 0 : memset(state->parts, 0, state->limit * sizeof(state->parts[0]));
147 0 : res = check_part[i++](state);
148 0 : if (res < 0) {
149 : /*
150 : * We have hit an I/O error which we don't report now.
151 : * But record it, and let the others do their job.
152 : */
153 0 : err = res;
154 0 : res = 0;
155 : }
156 :
157 : }
158 0 : if (res > 0) {
159 0 : printk(KERN_INFO "%s", state->pp_buf);
160 :
161 0 : free_page((unsigned long)state->pp_buf);
162 0 : return state;
163 : }
164 0 : if (state->access_beyond_eod)
165 0 : err = -ENOSPC;
166 : /*
167 : * The partition is unrecognized. So report I/O errors if there were any
168 : */
169 0 : if (err)
170 0 : res = err;
171 0 : if (res) {
172 0 : strlcat(state->pp_buf,
173 : " unable to read partition table\n", PAGE_SIZE);
174 0 : printk(KERN_INFO "%s", state->pp_buf);
175 : }
176 :
177 0 : free_page((unsigned long)state->pp_buf);
178 0 : free_partitions(state);
179 0 : return ERR_PTR(res);
180 : }
181 :
182 0 : static ssize_t part_partition_show(struct device *dev,
183 : struct device_attribute *attr, char *buf)
184 : {
185 0 : return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_partno);
186 : }
187 :
188 0 : static ssize_t part_start_show(struct device *dev,
189 : struct device_attribute *attr, char *buf)
190 : {
191 0 : return sprintf(buf, "%llu\n", dev_to_bdev(dev)->bd_start_sect);
192 : }
193 :
194 0 : static ssize_t part_ro_show(struct device *dev,
195 : struct device_attribute *attr, char *buf)
196 : {
197 0 : return sprintf(buf, "%d\n", bdev_read_only(dev_to_bdev(dev)));
198 : }
199 :
200 0 : static ssize_t part_alignment_offset_show(struct device *dev,
201 : struct device_attribute *attr, char *buf)
202 : {
203 0 : struct block_device *bdev = dev_to_bdev(dev);
204 :
205 0 : return sprintf(buf, "%u\n",
206 0 : queue_limit_alignment_offset(&bdev_get_queue(bdev)->limits,
207 : bdev->bd_start_sect));
208 : }
209 :
210 0 : static ssize_t part_discard_alignment_show(struct device *dev,
211 : struct device_attribute *attr, char *buf)
212 : {
213 0 : struct block_device *bdev = dev_to_bdev(dev);
214 :
215 0 : return sprintf(buf, "%u\n",
216 0 : queue_limit_discard_alignment(&bdev_get_queue(bdev)->limits,
217 : bdev->bd_start_sect));
218 : }
219 :
220 : static DEVICE_ATTR(partition, 0444, part_partition_show, NULL);
221 : static DEVICE_ATTR(start, 0444, part_start_show, NULL);
222 : static DEVICE_ATTR(size, 0444, part_size_show, NULL);
223 : static DEVICE_ATTR(ro, 0444, part_ro_show, NULL);
224 : static DEVICE_ATTR(alignment_offset, 0444, part_alignment_offset_show, NULL);
225 : static DEVICE_ATTR(discard_alignment, 0444, part_discard_alignment_show, NULL);
226 : static DEVICE_ATTR(stat, 0444, part_stat_show, NULL);
227 : static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL);
228 : #ifdef CONFIG_FAIL_MAKE_REQUEST
229 : static struct device_attribute dev_attr_fail =
230 : __ATTR(make-it-fail, 0644, part_fail_show, part_fail_store);
231 : #endif
232 :
233 : static struct attribute *part_attrs[] = {
234 : &dev_attr_partition.attr,
235 : &dev_attr_start.attr,
236 : &dev_attr_size.attr,
237 : &dev_attr_ro.attr,
238 : &dev_attr_alignment_offset.attr,
239 : &dev_attr_discard_alignment.attr,
240 : &dev_attr_stat.attr,
241 : &dev_attr_inflight.attr,
242 : #ifdef CONFIG_FAIL_MAKE_REQUEST
243 : &dev_attr_fail.attr,
244 : #endif
245 : NULL
246 : };
247 :
248 : static struct attribute_group part_attr_group = {
249 : .attrs = part_attrs,
250 : };
251 :
252 : static const struct attribute_group *part_attr_groups[] = {
253 : &part_attr_group,
254 : #ifdef CONFIG_BLK_DEV_IO_TRACE
255 : &blk_trace_attr_group,
256 : #endif
257 : NULL
258 : };
259 :
260 0 : static void part_release(struct device *dev)
261 : {
262 0 : put_disk(dev_to_bdev(dev)->bd_disk);
263 0 : iput(dev_to_bdev(dev)->bd_inode);
264 0 : }
265 :
266 0 : static int part_uevent(struct device *dev, struct kobj_uevent_env *env)
267 : {
268 0 : struct block_device *part = dev_to_bdev(dev);
269 :
270 0 : add_uevent_var(env, "PARTN=%u", part->bd_partno);
271 0 : if (part->bd_meta_info && part->bd_meta_info->volname[0])
272 0 : add_uevent_var(env, "PARTNAME=%s", part->bd_meta_info->volname);
273 0 : return 0;
274 : }
275 :
276 : struct device_type part_type = {
277 : .name = "partition",
278 : .groups = part_attr_groups,
279 : .release = part_release,
280 : .uevent = part_uevent,
281 : };
282 :
283 0 : static void delete_partition(struct block_device *part)
284 : {
285 : lockdep_assert_held(&part->bd_disk->open_mutex);
286 :
287 0 : fsync_bdev(part);
288 0 : __invalidate_device(part, true);
289 :
290 0 : xa_erase(&part->bd_disk->part_tbl, part->bd_partno);
291 0 : kobject_put(part->bd_holder_dir);
292 0 : 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 0 : remove_inode_hash(part->bd_inode);
299 :
300 0 : put_device(&part->bd_device);
301 0 : }
302 :
303 0 : static ssize_t whole_disk_show(struct device *dev,
304 : struct device_attribute *attr, char *buf)
305 : {
306 0 : return 0;
307 : }
308 : static DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL);
309 :
310 : /*
311 : * Must be called either with open_mutex held, before a disk can be opened or
312 : * after all disk users are gone.
313 : */
314 0 : 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 0 : dev_t devt = MKDEV(0, 0);
319 0 : 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 : lockdep_assert_held(&disk->open_mutex);
326 :
327 0 : if (partno >= DISK_MAX_PARTS)
328 : return ERR_PTR(-EINVAL);
329 :
330 : /*
331 : * Partitions are not supported on zoned block devices that are used as
332 : * such.
333 : */
334 0 : switch (disk->queue->limits.zoned) {
335 : case BLK_ZONED_HM:
336 0 : pr_warn("%s: partitions not supported on host managed zoned block device\n",
337 : disk->disk_name);
338 0 : return ERR_PTR(-ENXIO);
339 : case BLK_ZONED_HA:
340 0 : pr_info("%s: disabling host aware zoned block device support due to partitions\n",
341 : disk->disk_name);
342 0 : blk_queue_set_zoned(disk, BLK_ZONED_NONE);
343 0 : break;
344 : case BLK_ZONED_NONE:
345 : break;
346 : }
347 :
348 0 : if (xa_load(&disk->part_tbl, partno))
349 : return ERR_PTR(-EBUSY);
350 :
351 : /* ensure we always have a reference to the whole disk */
352 0 : get_device(disk_to_dev(disk));
353 :
354 0 : err = -ENOMEM;
355 0 : bdev = bdev_alloc(disk, partno);
356 0 : if (!bdev)
357 : goto out_put_disk;
358 :
359 0 : bdev->bd_start_sect = start;
360 0 : bdev_set_nr_sectors(bdev, len);
361 :
362 0 : pdev = &bdev->bd_device;
363 0 : dname = dev_name(ddev);
364 0 : if (isdigit(dname[strlen(dname) - 1]))
365 0 : dev_set_name(pdev, "%sp%d", dname, partno);
366 : else
367 0 : dev_set_name(pdev, "%s%d", dname, partno);
368 :
369 0 : device_initialize(pdev);
370 0 : pdev->class = &block_class;
371 0 : pdev->type = &part_type;
372 0 : pdev->parent = ddev;
373 :
374 : /* in consecutive minor range? */
375 0 : if (bdev->bd_partno < disk->minors) {
376 0 : devt = MKDEV(disk->major, disk->first_minor + bdev->bd_partno);
377 : } else {
378 0 : err = blk_alloc_ext_minor();
379 0 : if (err < 0)
380 : goto out_put;
381 0 : devt = MKDEV(BLOCK_EXT_MAJOR, err);
382 : }
383 0 : pdev->devt = devt;
384 :
385 0 : if (info) {
386 0 : err = -ENOMEM;
387 0 : bdev->bd_meta_info = kmemdup(info, sizeof(*info), GFP_KERNEL);
388 0 : if (!bdev->bd_meta_info)
389 : goto out_put;
390 : }
391 :
392 : /* delay uevent until 'holders' subdir is created */
393 0 : dev_set_uevent_suppress(pdev, 1);
394 0 : err = device_add(pdev);
395 0 : if (err)
396 : goto out_put;
397 :
398 0 : err = -ENOMEM;
399 0 : bdev->bd_holder_dir = kobject_create_and_add("holders", &pdev->kobj);
400 0 : if (!bdev->bd_holder_dir)
401 : goto out_del;
402 :
403 0 : dev_set_uevent_suppress(pdev, 0);
404 0 : if (flags & ADDPART_FLAG_WHOLEDISK) {
405 0 : err = device_create_file(pdev, &dev_attr_whole_disk);
406 0 : if (err)
407 : goto out_del;
408 : }
409 :
410 : /* everything is up and running, commence */
411 0 : err = xa_insert(&disk->part_tbl, partno, bdev, GFP_KERNEL);
412 0 : if (err)
413 : goto out_del;
414 0 : bdev_add(bdev, devt);
415 :
416 : /* suppress uevent if the disk suppresses it */
417 0 : if (!dev_get_uevent_suppress(ddev))
418 0 : kobject_uevent(&pdev->kobj, KOBJ_ADD);
419 : return bdev;
420 :
421 : out_del:
422 0 : kobject_put(bdev->bd_holder_dir);
423 0 : device_del(pdev);
424 : out_put:
425 0 : put_device(pdev);
426 0 : return ERR_PTR(err);
427 : out_put_disk:
428 0 : put_disk(disk);
429 0 : return ERR_PTR(err);
430 : }
431 :
432 0 : static bool partition_overlaps(struct gendisk *disk, sector_t start,
433 : sector_t length, int skip_partno)
434 : {
435 : struct block_device *part;
436 0 : bool overlap = false;
437 : unsigned long idx;
438 :
439 : rcu_read_lock();
440 0 : xa_for_each_start(&disk->part_tbl, idx, part, 1) {
441 0 : if (part->bd_partno != skip_partno &&
442 0 : start < part->bd_start_sect + bdev_nr_sectors(part) &&
443 0 : start + length > part->bd_start_sect) {
444 : overlap = true;
445 : break;
446 : }
447 : }
448 : rcu_read_unlock();
449 :
450 0 : return overlap;
451 : }
452 :
453 0 : int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
454 : sector_t length)
455 : {
456 : struct block_device *part;
457 : int ret;
458 :
459 0 : mutex_lock(&disk->open_mutex);
460 0 : if (!disk_live(disk)) {
461 : ret = -ENXIO;
462 : goto out;
463 : }
464 :
465 0 : if (partition_overlaps(disk, start, length, -1)) {
466 : ret = -EBUSY;
467 : goto out;
468 : }
469 :
470 0 : part = add_partition(disk, partno, start, length,
471 : ADDPART_FLAG_NONE, NULL);
472 : ret = PTR_ERR_OR_ZERO(part);
473 : out:
474 0 : mutex_unlock(&disk->open_mutex);
475 0 : return ret;
476 : }
477 :
478 0 : int bdev_del_partition(struct gendisk *disk, int partno)
479 : {
480 0 : struct block_device *part = NULL;
481 0 : int ret = -ENXIO;
482 :
483 0 : mutex_lock(&disk->open_mutex);
484 0 : part = xa_load(&disk->part_tbl, partno);
485 0 : if (!part)
486 : goto out_unlock;
487 :
488 0 : ret = -EBUSY;
489 0 : if (part->bd_openers)
490 : goto out_unlock;
491 :
492 0 : delete_partition(part);
493 0 : ret = 0;
494 : out_unlock:
495 0 : mutex_unlock(&disk->open_mutex);
496 0 : return ret;
497 : }
498 :
499 0 : int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start,
500 : sector_t length)
501 : {
502 0 : struct block_device *part = NULL;
503 0 : int ret = -ENXIO;
504 :
505 0 : mutex_lock(&disk->open_mutex);
506 0 : part = xa_load(&disk->part_tbl, partno);
507 0 : if (!part)
508 : goto out_unlock;
509 :
510 0 : ret = -EINVAL;
511 0 : if (start != part->bd_start_sect)
512 : goto out_unlock;
513 :
514 0 : ret = -EBUSY;
515 0 : if (partition_overlaps(disk, start, length, partno))
516 : goto out_unlock;
517 :
518 0 : bdev_set_nr_sectors(part, length);
519 :
520 0 : ret = 0;
521 : out_unlock:
522 0 : mutex_unlock(&disk->open_mutex);
523 0 : return ret;
524 : }
525 :
526 0 : static bool disk_unlock_native_capacity(struct gendisk *disk)
527 : {
528 0 : if (!disk->fops->unlock_native_capacity ||
529 0 : test_and_set_bit(GD_NATIVE_CAPACITY, &disk->state)) {
530 0 : printk(KERN_CONT "truncated\n");
531 0 : return false;
532 : }
533 :
534 0 : printk(KERN_CONT "enabling native capacity\n");
535 0 : disk->fops->unlock_native_capacity(disk);
536 0 : return true;
537 : }
538 :
539 0 : void blk_drop_partitions(struct gendisk *disk)
540 : {
541 : struct block_device *part;
542 : unsigned long idx;
543 :
544 : lockdep_assert_held(&disk->open_mutex);
545 :
546 0 : xa_for_each_start(&disk->part_tbl, idx, part, 1)
547 0 : delete_partition(part);
548 0 : }
549 :
550 0 : static bool blk_add_partition(struct gendisk *disk,
551 : struct parsed_partitions *state, int p)
552 : {
553 0 : sector_t size = state->parts[p].size;
554 0 : sector_t from = state->parts[p].from;
555 : struct block_device *part;
556 :
557 0 : if (!size)
558 : return true;
559 :
560 0 : if (from >= get_capacity(disk)) {
561 0 : printk(KERN_WARNING
562 : "%s: p%d start %llu is beyond EOD, ",
563 : disk->disk_name, p, (unsigned long long) from);
564 0 : if (disk_unlock_native_capacity(disk))
565 : return false;
566 : return true;
567 : }
568 :
569 0 : if (from + size > get_capacity(disk)) {
570 0 : printk(KERN_WARNING
571 : "%s: p%d size %llu extends beyond EOD, ",
572 : disk->disk_name, p, (unsigned long long) size);
573 :
574 0 : if (disk_unlock_native_capacity(disk))
575 : return false;
576 :
577 : /*
578 : * We can not ignore partitions of broken tables created by for
579 : * example camera firmware, but we limit them to the end of the
580 : * disk to avoid creating invalid block devices.
581 : */
582 0 : size = get_capacity(disk) - from;
583 : }
584 :
585 0 : part = add_partition(disk, p, from, size, state->parts[p].flags,
586 0 : &state->parts[p].info);
587 0 : if (IS_ERR(part) && PTR_ERR(part) != -ENXIO) {
588 0 : printk(KERN_ERR " %s: p%d could not be added: %ld\n",
589 : disk->disk_name, p, -PTR_ERR(part));
590 : return true;
591 : }
592 :
593 : if (IS_BUILTIN(CONFIG_BLK_DEV_MD) &&
594 : (state->parts[p].flags & ADDPART_FLAG_RAID))
595 : md_autodetect_dev(part->bd_dev);
596 :
597 : return true;
598 : }
599 :
600 0 : static int blk_add_partitions(struct gendisk *disk)
601 : {
602 : struct parsed_partitions *state;
603 0 : int ret = -EAGAIN, p;
604 :
605 0 : if (disk->flags & GENHD_FL_NO_PART)
606 : return 0;
607 :
608 0 : state = check_partition(disk);
609 0 : if (!state)
610 : return 0;
611 0 : if (IS_ERR(state)) {
612 : /*
613 : * I/O error reading the partition table. If we tried to read
614 : * beyond EOD, retry after unlocking the native capacity.
615 : */
616 0 : if (PTR_ERR(state) == -ENOSPC) {
617 0 : printk(KERN_WARNING "%s: partition table beyond EOD, ",
618 : disk->disk_name);
619 0 : if (disk_unlock_native_capacity(disk))
620 : return -EAGAIN;
621 : }
622 : return -EIO;
623 : }
624 :
625 : /*
626 : * Partitions are not supported on host managed zoned block devices.
627 : */
628 0 : if (disk->queue->limits.zoned == BLK_ZONED_HM) {
629 0 : pr_warn("%s: ignoring partition table on host managed zoned block device\n",
630 : disk->disk_name);
631 0 : ret = 0;
632 0 : goto out_free_state;
633 : }
634 :
635 : /*
636 : * If we read beyond EOD, try unlocking native capacity even if the
637 : * partition table was successfully read as we could be missing some
638 : * partitions.
639 : */
640 0 : if (state->access_beyond_eod) {
641 0 : printk(KERN_WARNING
642 : "%s: partition table partially beyond EOD, ",
643 : disk->disk_name);
644 0 : if (disk_unlock_native_capacity(disk))
645 : goto out_free_state;
646 : }
647 :
648 : /* tell userspace that the media / partition table may have changed */
649 0 : kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
650 :
651 0 : for (p = 1; p < state->limit; p++)
652 0 : if (!blk_add_partition(disk, state, p))
653 : goto out_free_state;
654 :
655 : ret = 0;
656 : out_free_state:
657 0 : free_partitions(state);
658 0 : return ret;
659 : }
660 :
661 0 : int bdev_disk_changed(struct gendisk *disk, bool invalidate)
662 : {
663 0 : int ret = 0;
664 :
665 : lockdep_assert_held(&disk->open_mutex);
666 :
667 0 : if (!disk_live(disk))
668 : return -ENXIO;
669 :
670 : rescan:
671 0 : if (disk->open_partitions)
672 : return -EBUSY;
673 0 : sync_blockdev(disk->part0);
674 0 : invalidate_bdev(disk->part0);
675 0 : blk_drop_partitions(disk);
676 :
677 0 : clear_bit(GD_NEED_PART_SCAN, &disk->state);
678 :
679 : /*
680 : * Historically we only set the capacity to zero for devices that
681 : * support partitions (independ of actually having partitions created).
682 : * Doing that is rather inconsistent, but changing it broke legacy
683 : * udisks polling for legacy ide-cdrom devices. Use the crude check
684 : * below to get the sane behavior for most device while not breaking
685 : * userspace for this particular setup.
686 : */
687 0 : if (invalidate) {
688 0 : if (!(disk->flags & GENHD_FL_NO_PART) ||
689 : !(disk->flags & GENHD_FL_REMOVABLE))
690 0 : set_capacity(disk, 0);
691 : }
692 :
693 0 : if (get_capacity(disk)) {
694 0 : ret = blk_add_partitions(disk);
695 0 : if (ret == -EAGAIN)
696 : goto rescan;
697 0 : } else if (invalidate) {
698 : /*
699 : * Tell userspace that the media / partition table may have
700 : * changed.
701 : */
702 0 : kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
703 : }
704 :
705 : return ret;
706 : }
707 : /*
708 : * Only exported for loop and dasd for historic reasons. Don't use in new
709 : * code!
710 : */
711 : EXPORT_SYMBOL_GPL(bdev_disk_changed);
712 :
713 0 : void *read_part_sector(struct parsed_partitions *state, sector_t n, Sector *p)
714 : {
715 0 : struct address_space *mapping = state->disk->part0->bd_inode->i_mapping;
716 : struct page *page;
717 :
718 0 : if (n >= get_capacity(state->disk)) {
719 0 : state->access_beyond_eod = true;
720 0 : return NULL;
721 : }
722 :
723 0 : page = read_mapping_page(mapping,
724 0 : (pgoff_t)(n >> (PAGE_SHIFT - 9)), NULL);
725 0 : if (IS_ERR(page))
726 : goto out;
727 0 : if (PageError(page))
728 : goto out_put_page;
729 :
730 0 : p->v = page;
731 0 : return (unsigned char *)page_address(page) +
732 0 : ((n & ((1 << (PAGE_SHIFT - 9)) - 1)) << SECTOR_SHIFT);
733 : out_put_page:
734 0 : put_page(page);
735 : out:
736 0 : p->v = NULL;
737 0 : return NULL;
738 : }
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