blob: c5ec8246e25e1ed3eb6aef683c99e4aacd32ce2c [file] [log] [blame]
Al Viro94ea4152011-09-16 00:45:36 -04001/*
2 * Code extracted from drivers/block/genhd.c
3 * Copyright (C) 1991-1998 Linus Torvalds
4 * Re-organised Feb 1998 Russell King
5 *
6 * We now have independent partition support from the
7 * block drivers, which allows all the partition code to
8 * be grouped in one location, and it to be mostly self
9 * contained.
10 */
11
12#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/fs.h>
15#include <linux/slab.h>
16#include <linux/kmod.h>
17#include <linux/ctype.h>
18#include <linux/genhd.h>
19#include <linux/blktrace_api.h>
20
21#include "partitions/check.h"
22
23#ifdef CONFIG_BLK_DEV_MD
24extern void md_autodetect_dev(dev_t dev);
25#endif
26
27/*
28 * disk_name() is used by partition check code and the genhd driver.
29 * It formats the devicename of the indicated disk into
30 * the supplied buffer (of size at least 32), and returns
31 * a pointer to that same buffer (for convenience).
32 */
33
34char *disk_name(struct gendisk *hd, int partno, char *buf)
35{
36 if (!partno)
37 snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
38 else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
39 snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, partno);
40 else
41 snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno);
42
43 return buf;
44}
45
46const char *bdevname(struct block_device *bdev, char *buf)
47{
48 return disk_name(bdev->bd_disk, bdev->bd_part->partno, buf);
49}
50
51EXPORT_SYMBOL(bdevname);
52
53/*
54 * There's very little reason to use this, you should really
55 * have a struct block_device just about everywhere and use
56 * bdevname() instead.
57 */
58const char *__bdevname(dev_t dev, char *buffer)
59{
60 scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)",
61 MAJOR(dev), MINOR(dev));
62 return buffer;
63}
64
65EXPORT_SYMBOL(__bdevname);
66
67static ssize_t part_partition_show(struct device *dev,
68 struct device_attribute *attr, char *buf)
69{
70 struct hd_struct *p = dev_to_part(dev);
71
72 return sprintf(buf, "%d\n", p->partno);
73}
74
75static ssize_t part_start_show(struct device *dev,
76 struct device_attribute *attr, char *buf)
77{
78 struct hd_struct *p = dev_to_part(dev);
79
80 return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect);
81}
82
83ssize_t part_size_show(struct device *dev,
84 struct device_attribute *attr, char *buf)
85{
86 struct hd_struct *p = dev_to_part(dev);
Vivek Goyalc83f6bf2012-08-01 12:24:18 +020087 return sprintf(buf, "%llu\n",(unsigned long long)part_nr_sects_read(p));
Al Viro94ea4152011-09-16 00:45:36 -040088}
89
90static ssize_t part_ro_show(struct device *dev,
91 struct device_attribute *attr, char *buf)
92{
93 struct hd_struct *p = dev_to_part(dev);
94 return sprintf(buf, "%d\n", p->policy ? 1 : 0);
95}
96
97static ssize_t part_alignment_offset_show(struct device *dev,
98 struct device_attribute *attr, char *buf)
99{
100 struct hd_struct *p = dev_to_part(dev);
101 return sprintf(buf, "%llu\n", (unsigned long long)p->alignment_offset);
102}
103
104static ssize_t part_discard_alignment_show(struct device *dev,
105 struct device_attribute *attr, char *buf)
106{
107 struct hd_struct *p = dev_to_part(dev);
108 return sprintf(buf, "%u\n", p->discard_alignment);
109}
110
111ssize_t part_stat_show(struct device *dev,
112 struct device_attribute *attr, char *buf)
113{
114 struct hd_struct *p = dev_to_part(dev);
115 int cpu;
116
117 cpu = part_stat_lock();
118 part_round_stats(cpu, p);
119 part_stat_unlock();
120 return sprintf(buf,
121 "%8lu %8lu %8llu %8u "
122 "%8lu %8lu %8llu %8u "
123 "%8u %8u %8u"
124 "\n",
125 part_stat_read(p, ios[READ]),
126 part_stat_read(p, merges[READ]),
127 (unsigned long long)part_stat_read(p, sectors[READ]),
128 jiffies_to_msecs(part_stat_read(p, ticks[READ])),
129 part_stat_read(p, ios[WRITE]),
130 part_stat_read(p, merges[WRITE]),
131 (unsigned long long)part_stat_read(p, sectors[WRITE]),
132 jiffies_to_msecs(part_stat_read(p, ticks[WRITE])),
133 part_in_flight(p),
134 jiffies_to_msecs(part_stat_read(p, io_ticks)),
135 jiffies_to_msecs(part_stat_read(p, time_in_queue)));
136}
137
138ssize_t part_inflight_show(struct device *dev,
139 struct device_attribute *attr, char *buf)
140{
141 struct hd_struct *p = dev_to_part(dev);
142
143 return sprintf(buf, "%8u %8u\n", atomic_read(&p->in_flight[0]),
144 atomic_read(&p->in_flight[1]));
145}
146
147#ifdef CONFIG_FAIL_MAKE_REQUEST
148ssize_t part_fail_show(struct device *dev,
149 struct device_attribute *attr, char *buf)
150{
151 struct hd_struct *p = dev_to_part(dev);
152
153 return sprintf(buf, "%d\n", p->make_it_fail);
154}
155
156ssize_t part_fail_store(struct device *dev,
157 struct device_attribute *attr,
158 const char *buf, size_t count)
159{
160 struct hd_struct *p = dev_to_part(dev);
161 int i;
162
163 if (count > 0 && sscanf(buf, "%d", &i) > 0)
164 p->make_it_fail = (i == 0) ? 0 : 1;
165
166 return count;
167}
168#endif
169
170static DEVICE_ATTR(partition, S_IRUGO, part_partition_show, NULL);
171static DEVICE_ATTR(start, S_IRUGO, part_start_show, NULL);
172static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
173static DEVICE_ATTR(ro, S_IRUGO, part_ro_show, NULL);
174static DEVICE_ATTR(alignment_offset, S_IRUGO, part_alignment_offset_show, NULL);
175static DEVICE_ATTR(discard_alignment, S_IRUGO, part_discard_alignment_show,
176 NULL);
177static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
178static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL);
179#ifdef CONFIG_FAIL_MAKE_REQUEST
180static struct device_attribute dev_attr_fail =
181 __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
182#endif
183
184static struct attribute *part_attrs[] = {
185 &dev_attr_partition.attr,
186 &dev_attr_start.attr,
187 &dev_attr_size.attr,
188 &dev_attr_ro.attr,
189 &dev_attr_alignment_offset.attr,
190 &dev_attr_discard_alignment.attr,
191 &dev_attr_stat.attr,
192 &dev_attr_inflight.attr,
193#ifdef CONFIG_FAIL_MAKE_REQUEST
194 &dev_attr_fail.attr,
195#endif
196 NULL
197};
198
199static struct attribute_group part_attr_group = {
200 .attrs = part_attrs,
201};
202
203static const struct attribute_group *part_attr_groups[] = {
204 &part_attr_group,
205#ifdef CONFIG_BLK_DEV_IO_TRACE
206 &blk_trace_attr_group,
207#endif
208 NULL
209};
210
211static void part_release(struct device *dev)
212{
213 struct hd_struct *p = dev_to_part(dev);
Keith Busch2da78092014-08-26 09:05:36 -0600214 blk_free_devt(dev->devt);
Ming Leib54e5ed2015-07-16 11:16:44 +0800215 hd_free_part(p);
Al Viro94ea4152011-09-16 00:45:36 -0400216 kfree(p);
217}
218
San Mehat0d9c51a2016-03-15 14:53:26 -0700219static int part_uevent(struct device *dev, struct kobj_uevent_env *env)
220{
221 struct hd_struct *part = dev_to_part(dev);
222
223 add_uevent_var(env, "PARTN=%u", part->partno);
224 if (part->info && part->info->volname[0])
225 add_uevent_var(env, "PARTNAME=%s", part->info->volname);
226 return 0;
227}
228
Al Viro94ea4152011-09-16 00:45:36 -0400229struct device_type part_type = {
230 .name = "partition",
231 .groups = part_attr_groups,
232 .release = part_release,
San Mehat0d9c51a2016-03-15 14:53:26 -0700233 .uevent = part_uevent,
Al Viro94ea4152011-09-16 00:45:36 -0400234};
235
236static void delete_partition_rcu_cb(struct rcu_head *head)
237{
238 struct hd_struct *part = container_of(head, struct hd_struct, rcu_head);
239
240 part->start_sect = 0;
241 part->nr_sects = 0;
242 part_stat_set_all(part, 0);
243 put_device(part_to_dev(part));
244}
245
Ming Lei6c710132015-07-16 11:16:45 +0800246void __delete_partition(struct percpu_ref *ref)
Al Viro94ea4152011-09-16 00:45:36 -0400247{
Ming Lei6c710132015-07-16 11:16:45 +0800248 struct hd_struct *part = container_of(ref, struct hd_struct, ref);
Al Viro94ea4152011-09-16 00:45:36 -0400249 call_rcu(&part->rcu_head, delete_partition_rcu_cb);
250}
251
252void delete_partition(struct gendisk *disk, int partno)
253{
254 struct disk_part_tbl *ptbl = disk->part_tbl;
255 struct hd_struct *part;
256
257 if (partno >= ptbl->len)
258 return;
259
260 part = ptbl->part[partno];
261 if (!part)
262 return;
263
Al Viro94ea4152011-09-16 00:45:36 -0400264 rcu_assign_pointer(ptbl->part[partno], NULL);
265 rcu_assign_pointer(ptbl->last_lookup, NULL);
266 kobject_put(part->holder_dir);
267 device_del(part_to_dev(part));
268
Ming Lei6c710132015-07-16 11:16:45 +0800269 hd_struct_kill(part);
Al Viro94ea4152011-09-16 00:45:36 -0400270}
271
272static ssize_t whole_disk_show(struct device *dev,
273 struct device_attribute *attr, char *buf)
274{
275 return 0;
276}
277static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH,
278 whole_disk_show, NULL);
279
280struct hd_struct *add_partition(struct gendisk *disk, int partno,
281 sector_t start, sector_t len, int flags,
282 struct partition_meta_info *info)
283{
284 struct hd_struct *p;
285 dev_t devt = MKDEV(0, 0);
286 struct device *ddev = disk_to_dev(disk);
287 struct device *pdev;
288 struct disk_part_tbl *ptbl;
289 const char *dname;
290 int err;
291
292 err = disk_expand_part_tbl(disk, partno);
293 if (err)
294 return ERR_PTR(err);
295 ptbl = disk->part_tbl;
296
297 if (ptbl->part[partno])
298 return ERR_PTR(-EBUSY);
299
300 p = kzalloc(sizeof(*p), GFP_KERNEL);
301 if (!p)
302 return ERR_PTR(-EBUSY);
303
304 if (!init_part_stats(p)) {
305 err = -ENOMEM;
306 goto out_free;
307 }
Vivek Goyalc83f6bf2012-08-01 12:24:18 +0200308
309 seqcount_init(&p->nr_sects_seq);
Al Viro94ea4152011-09-16 00:45:36 -0400310 pdev = part_to_dev(p);
311
312 p->start_sect = start;
313 p->alignment_offset =
314 queue_limit_alignment_offset(&disk->queue->limits, start);
315 p->discard_alignment =
316 queue_limit_discard_alignment(&disk->queue->limits, start);
317 p->nr_sects = len;
318 p->partno = partno;
319 p->policy = get_disk_ro(disk);
320
321 if (info) {
322 struct partition_meta_info *pinfo = alloc_part_info(disk);
Dan Carpenter7bd897c2017-05-23 17:28:36 +0300323 if (!pinfo) {
324 err = -ENOMEM;
Al Viro94ea4152011-09-16 00:45:36 -0400325 goto out_free_stats;
Dan Carpenter7bd897c2017-05-23 17:28:36 +0300326 }
Al Viro94ea4152011-09-16 00:45:36 -0400327 memcpy(pinfo, info, sizeof(*info));
328 p->info = pinfo;
329 }
330
331 dname = dev_name(ddev);
332 if (isdigit(dname[strlen(dname) - 1]))
333 dev_set_name(pdev, "%sp%d", dname, partno);
334 else
335 dev_set_name(pdev, "%s%d", dname, partno);
336
337 device_initialize(pdev);
338 pdev->class = &block_class;
339 pdev->type = &part_type;
340 pdev->parent = ddev;
341
342 err = blk_alloc_devt(p, &devt);
343 if (err)
344 goto out_free_info;
345 pdev->devt = devt;
346
347 /* delay uevent until 'holders' subdir is created */
348 dev_set_uevent_suppress(pdev, 1);
349 err = device_add(pdev);
350 if (err)
351 goto out_put;
352
353 err = -ENOMEM;
354 p->holder_dir = kobject_create_and_add("holders", &pdev->kobj);
355 if (!p->holder_dir)
356 goto out_del;
357
358 dev_set_uevent_suppress(pdev, 0);
359 if (flags & ADDPART_FLAG_WHOLEDISK) {
360 err = device_create_file(pdev, &dev_attr_whole_disk);
361 if (err)
362 goto out_del;
363 }
364
Ming Leib30a337ca2016-03-30 08:46:31 +0800365 err = hd_ref_init(p);
366 if (err) {
367 if (flags & ADDPART_FLAG_WHOLEDISK)
368 goto out_remove_file;
369 goto out_del;
370 }
371
Al Viro94ea4152011-09-16 00:45:36 -0400372 /* everything is up and running, commence */
373 rcu_assign_pointer(ptbl->part[partno], p);
374
375 /* suppress uevent if the disk suppresses it */
376 if (!dev_get_uevent_suppress(ddev))
377 kobject_uevent(&pdev->kobj, KOBJ_ADD);
Ming Leib30a337ca2016-03-30 08:46:31 +0800378 return p;
Al Viro94ea4152011-09-16 00:45:36 -0400379
380out_free_info:
381 free_part_info(p);
382out_free_stats:
383 free_part_stats(p);
384out_free:
385 kfree(p);
386 return ERR_PTR(err);
Ming Leib30a337ca2016-03-30 08:46:31 +0800387out_remove_file:
388 device_remove_file(pdev, &dev_attr_whole_disk);
Al Viro94ea4152011-09-16 00:45:36 -0400389out_del:
390 kobject_put(p->holder_dir);
391 device_del(pdev);
392out_put:
393 put_device(pdev);
394 blk_free_devt(devt);
395 return ERR_PTR(err);
396}
397
398static bool disk_unlock_native_capacity(struct gendisk *disk)
399{
400 const struct block_device_operations *bdops = disk->fops;
401
402 if (bdops->unlock_native_capacity &&
403 !(disk->flags & GENHD_FL_NATIVE_CAPACITY)) {
404 printk(KERN_CONT "enabling native capacity\n");
405 bdops->unlock_native_capacity(disk);
406 disk->flags |= GENHD_FL_NATIVE_CAPACITY;
407 return true;
408 } else {
409 printk(KERN_CONT "truncated\n");
410 return false;
411 }
412}
413
Jun'ichi Nomurafe316bf2012-03-02 10:38:33 +0100414static int drop_partitions(struct gendisk *disk, struct block_device *bdev)
Al Viro94ea4152011-09-16 00:45:36 -0400415{
Al Viro94ea4152011-09-16 00:45:36 -0400416 struct disk_part_iter piter;
417 struct hd_struct *part;
Jun'ichi Nomurafe316bf2012-03-02 10:38:33 +0100418 int res;
Al Viro94ea4152011-09-16 00:45:36 -0400419
Eric Sandeen77032ca2015-11-24 17:30:34 -0600420 if (bdev->bd_part_count || bdev->bd_super)
Al Viro94ea4152011-09-16 00:45:36 -0400421 return -EBUSY;
422 res = invalidate_partition(disk, 0);
423 if (res)
424 return res;
425
426 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
427 while ((part = disk_part_iter_next(&piter)))
428 delete_partition(disk, part->partno);
429 disk_part_iter_exit(&piter);
430
Jun'ichi Nomurafe316bf2012-03-02 10:38:33 +0100431 return 0;
432}
433
Damien Le Moalb02d8aa2016-12-01 16:00:25 +0900434static bool part_zone_aligned(struct gendisk *disk,
435 struct block_device *bdev,
436 sector_t from, sector_t size)
437{
Damien Le Moalf99e8642017-01-12 07:58:32 -0700438 unsigned int zone_sectors = bdev_zone_sectors(bdev);
Damien Le Moalb02d8aa2016-12-01 16:00:25 +0900439
440 /*
441 * If this function is called, then the disk is a zoned block device
442 * (host-aware or host-managed). This can be detected even if the
443 * zoned block device support is disabled (CONFIG_BLK_DEV_ZONED not
444 * set). In this case, however, only host-aware devices will be seen
445 * as a block device is not created for host-managed devices. Without
446 * zoned block device support, host-aware drives can still be used as
447 * regular block devices (no zone operation) and their zone size will
448 * be reported as 0. Allow this case.
449 */
Damien Le Moalf99e8642017-01-12 07:58:32 -0700450 if (!zone_sectors)
Damien Le Moalb02d8aa2016-12-01 16:00:25 +0900451 return true;
452
453 /*
454 * Check partition start and size alignement. If the drive has a
455 * smaller last runt zone, ignore it and allow the partition to
456 * use it. Check the zone size too: it should be a power of 2 number
457 * of sectors.
458 */
Damien Le Moalf99e8642017-01-12 07:58:32 -0700459 if (WARN_ON_ONCE(!is_power_of_2(zone_sectors))) {
Damien Le Moalb02d8aa2016-12-01 16:00:25 +0900460 u32 rem;
461
Damien Le Moalf99e8642017-01-12 07:58:32 -0700462 div_u64_rem(from, zone_sectors, &rem);
Damien Le Moalb02d8aa2016-12-01 16:00:25 +0900463 if (rem)
464 return false;
465 if ((from + size) < get_capacity(disk)) {
Damien Le Moalf99e8642017-01-12 07:58:32 -0700466 div_u64_rem(size, zone_sectors, &rem);
Damien Le Moalb02d8aa2016-12-01 16:00:25 +0900467 if (rem)
468 return false;
469 }
470
471 } else {
472
Damien Le Moalf99e8642017-01-12 07:58:32 -0700473 if (from & (zone_sectors - 1))
Damien Le Moalb02d8aa2016-12-01 16:00:25 +0900474 return false;
475 if ((from + size) < get_capacity(disk) &&
Damien Le Moalf99e8642017-01-12 07:58:32 -0700476 (size & (zone_sectors - 1)))
Damien Le Moalb02d8aa2016-12-01 16:00:25 +0900477 return false;
478
479 }
480
481 return true;
482}
483
Jun'ichi Nomurafe316bf2012-03-02 10:38:33 +0100484int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
485{
486 struct parsed_partitions *state = NULL;
487 struct hd_struct *part;
488 int p, highest, res;
489rescan:
490 if (state && !IS_ERR(state)) {
Ming Leiac2e5322013-02-27 17:05:19 -0800491 free_partitions(state);
Jun'ichi Nomurafe316bf2012-03-02 10:38:33 +0100492 state = NULL;
493 }
494
495 res = drop_partitions(disk, bdev);
496 if (res)
497 return res;
498
Al Viro94ea4152011-09-16 00:45:36 -0400499 if (disk->fops->revalidate_disk)
500 disk->fops->revalidate_disk(disk);
501 check_disk_size_change(disk, bdev);
502 bdev->bd_invalidated = 0;
503 if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
504 return 0;
505 if (IS_ERR(state)) {
506 /*
507 * I/O error reading the partition table. If any
508 * partition code tried to read beyond EOD, retry
509 * after unlocking native capacity.
510 */
511 if (PTR_ERR(state) == -ENOSPC) {
512 printk(KERN_WARNING "%s: partition table beyond EOD, ",
513 disk->disk_name);
514 if (disk_unlock_native_capacity(disk))
515 goto rescan;
516 }
517 return -EIO;
518 }
519 /*
520 * If any partition code tried to read beyond EOD, try
521 * unlocking native capacity even if partition table is
522 * successfully read as we could be missing some partitions.
523 */
524 if (state->access_beyond_eod) {
525 printk(KERN_WARNING
526 "%s: partition table partially beyond EOD, ",
527 disk->disk_name);
528 if (disk_unlock_native_capacity(disk))
529 goto rescan;
530 }
531
532 /* tell userspace that the media / partition table may have changed */
533 kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
534
535 /* Detect the highest partition number and preallocate
536 * disk->part_tbl. This is an optimization and not strictly
537 * necessary.
538 */
539 for (p = 1, highest = 0; p < state->limit; p++)
540 if (state->parts[p].size)
541 highest = p;
542
543 disk_expand_part_tbl(disk, highest);
544
545 /* add partitions */
546 for (p = 1; p < state->limit; p++) {
547 sector_t size, from;
Al Viro94ea4152011-09-16 00:45:36 -0400548
549 size = state->parts[p].size;
550 if (!size)
551 continue;
552
553 from = state->parts[p].from;
554 if (from >= get_capacity(disk)) {
555 printk(KERN_WARNING
556 "%s: p%d start %llu is beyond EOD, ",
557 disk->disk_name, p, (unsigned long long) from);
558 if (disk_unlock_native_capacity(disk))
559 goto rescan;
560 continue;
561 }
562
563 if (from + size > get_capacity(disk)) {
564 printk(KERN_WARNING
565 "%s: p%d size %llu extends beyond EOD, ",
566 disk->disk_name, p, (unsigned long long) size);
567
568 if (disk_unlock_native_capacity(disk)) {
569 /* free state and restart */
570 goto rescan;
571 } else {
572 /*
573 * we can not ignore partitions of broken tables
574 * created by for example camera firmware, but
575 * we limit them to the end of the disk to avoid
576 * creating invalid block devices
577 */
578 size = get_capacity(disk) - from;
579 }
580 }
581
Damien Le Moalb02d8aa2016-12-01 16:00:25 +0900582 /*
583 * On a zoned block device, partitions should be aligned on the
584 * device zone size (i.e. zone boundary crossing not allowed).
585 * Otherwise, resetting the write pointer of the last zone of
586 * one partition may impact the following partition.
587 */
588 if (bdev_is_zoned(bdev) &&
589 !part_zone_aligned(disk, bdev, from, size)) {
590 printk(KERN_WARNING
591 "%s: p%d start %llu+%llu is not zone aligned\n",
592 disk->disk_name, p, (unsigned long long) from,
593 (unsigned long long) size);
594 continue;
595 }
596
Al Viro94ea4152011-09-16 00:45:36 -0400597 part = add_partition(disk, p, from, size,
598 state->parts[p].flags,
599 &state->parts[p].info);
600 if (IS_ERR(part)) {
601 printk(KERN_ERR " %s: p%d could not be added: %ld\n",
602 disk->disk_name, p, -PTR_ERR(part));
603 continue;
604 }
605#ifdef CONFIG_BLK_DEV_MD
606 if (state->parts[p].flags & ADDPART_FLAG_RAID)
607 md_autodetect_dev(part_to_dev(part)->devt);
608#endif
609 }
Ming Leiac2e5322013-02-27 17:05:19 -0800610 free_partitions(state);
Al Viro94ea4152011-09-16 00:45:36 -0400611 return 0;
612}
613
Jun'ichi Nomurafe316bf2012-03-02 10:38:33 +0100614int invalidate_partitions(struct gendisk *disk, struct block_device *bdev)
615{
616 int res;
617
618 if (!bdev->bd_invalidated)
619 return 0;
620
621 res = drop_partitions(disk, bdev);
622 if (res)
623 return res;
624
625 set_capacity(disk, 0);
626 check_disk_size_change(disk, bdev);
627 bdev->bd_invalidated = 0;
628 /* tell userspace that the media / partition table may have changed */
629 kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
630
631 return 0;
632}
633
Dan Williamsd1a5f2b42016-01-28 20:25:31 -0800634unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
635{
Dan Williamsa41fe02b2017-01-27 14:13:15 -0800636 struct address_space *mapping = bdev->bd_inode->i_mapping;
Al Viro94ea4152011-09-16 00:45:36 -0400637 struct page *page;
638
Dan Williamsa41fe02b2017-01-27 14:13:15 -0800639 page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_SHIFT-9)), NULL);
Al Viro94ea4152011-09-16 00:45:36 -0400640 if (!IS_ERR(page)) {
641 if (PageError(page))
642 goto fail;
643 p->v = page;
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300644 return (unsigned char *)page_address(page) + ((n & ((1 << (PAGE_SHIFT - 9)) - 1)) << 9);
Al Viro94ea4152011-09-16 00:45:36 -0400645fail:
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300646 put_page(page);
Al Viro94ea4152011-09-16 00:45:36 -0400647 }
648 p->v = NULL;
649 return NULL;
650}
651
652EXPORT_SYMBOL(read_dev_sector);