blob: a2437c0066402786762c5636ec928c2cca112d95 [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>
Dan Williamsd1a5f2b42016-01-28 20:25:31 -080019#include <linux/dax.h>
Al Viro94ea4152011-09-16 00:45:36 -040020#include <linux/blktrace_api.h>
21
22#include "partitions/check.h"
23
24#ifdef CONFIG_BLK_DEV_MD
25extern void md_autodetect_dev(dev_t dev);
26#endif
27
28/*
29 * disk_name() is used by partition check code and the genhd driver.
30 * It formats the devicename of the indicated disk into
31 * the supplied buffer (of size at least 32), and returns
32 * a pointer to that same buffer (for convenience).
33 */
34
35char *disk_name(struct gendisk *hd, int partno, char *buf)
36{
37 if (!partno)
38 snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
39 else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
40 snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, partno);
41 else
42 snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno);
43
44 return buf;
45}
46
47const char *bdevname(struct block_device *bdev, char *buf)
48{
49 return disk_name(bdev->bd_disk, bdev->bd_part->partno, buf);
50}
51
52EXPORT_SYMBOL(bdevname);
53
54/*
55 * There's very little reason to use this, you should really
56 * have a struct block_device just about everywhere and use
57 * bdevname() instead.
58 */
59const char *__bdevname(dev_t dev, char *buffer)
60{
61 scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)",
62 MAJOR(dev), MINOR(dev));
63 return buffer;
64}
65
66EXPORT_SYMBOL(__bdevname);
67
68static ssize_t part_partition_show(struct device *dev,
69 struct device_attribute *attr, char *buf)
70{
71 struct hd_struct *p = dev_to_part(dev);
72
73 return sprintf(buf, "%d\n", p->partno);
74}
75
76static ssize_t part_start_show(struct device *dev,
77 struct device_attribute *attr, char *buf)
78{
79 struct hd_struct *p = dev_to_part(dev);
80
81 return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect);
82}
83
84ssize_t part_size_show(struct device *dev,
85 struct device_attribute *attr, char *buf)
86{
87 struct hd_struct *p = dev_to_part(dev);
Vivek Goyalc83f6bf2012-08-01 12:24:18 +020088 return sprintf(buf, "%llu\n",(unsigned long long)part_nr_sects_read(p));
Al Viro94ea4152011-09-16 00:45:36 -040089}
90
91static ssize_t part_ro_show(struct device *dev,
92 struct device_attribute *attr, char *buf)
93{
94 struct hd_struct *p = dev_to_part(dev);
95 return sprintf(buf, "%d\n", p->policy ? 1 : 0);
96}
97
98static ssize_t part_alignment_offset_show(struct device *dev,
99 struct device_attribute *attr, char *buf)
100{
101 struct hd_struct *p = dev_to_part(dev);
102 return sprintf(buf, "%llu\n", (unsigned long long)p->alignment_offset);
103}
104
105static ssize_t part_discard_alignment_show(struct device *dev,
106 struct device_attribute *attr, char *buf)
107{
108 struct hd_struct *p = dev_to_part(dev);
109 return sprintf(buf, "%u\n", p->discard_alignment);
110}
111
112ssize_t part_stat_show(struct device *dev,
113 struct device_attribute *attr, char *buf)
114{
115 struct hd_struct *p = dev_to_part(dev);
116 int cpu;
117
118 cpu = part_stat_lock();
119 part_round_stats(cpu, p);
120 part_stat_unlock();
121 return sprintf(buf,
122 "%8lu %8lu %8llu %8u "
123 "%8lu %8lu %8llu %8u "
124 "%8u %8u %8u"
125 "\n",
126 part_stat_read(p, ios[READ]),
127 part_stat_read(p, merges[READ]),
128 (unsigned long long)part_stat_read(p, sectors[READ]),
129 jiffies_to_msecs(part_stat_read(p, ticks[READ])),
130 part_stat_read(p, ios[WRITE]),
131 part_stat_read(p, merges[WRITE]),
132 (unsigned long long)part_stat_read(p, sectors[WRITE]),
133 jiffies_to_msecs(part_stat_read(p, ticks[WRITE])),
134 part_in_flight(p),
135 jiffies_to_msecs(part_stat_read(p, io_ticks)),
136 jiffies_to_msecs(part_stat_read(p, time_in_queue)));
137}
138
139ssize_t part_inflight_show(struct device *dev,
140 struct device_attribute *attr, char *buf)
141{
142 struct hd_struct *p = dev_to_part(dev);
143
144 return sprintf(buf, "%8u %8u\n", atomic_read(&p->in_flight[0]),
145 atomic_read(&p->in_flight[1]));
146}
147
148#ifdef CONFIG_FAIL_MAKE_REQUEST
149ssize_t part_fail_show(struct device *dev,
150 struct device_attribute *attr, char *buf)
151{
152 struct hd_struct *p = dev_to_part(dev);
153
154 return sprintf(buf, "%d\n", p->make_it_fail);
155}
156
157ssize_t part_fail_store(struct device *dev,
158 struct device_attribute *attr,
159 const char *buf, size_t count)
160{
161 struct hd_struct *p = dev_to_part(dev);
162 int i;
163
164 if (count > 0 && sscanf(buf, "%d", &i) > 0)
165 p->make_it_fail = (i == 0) ? 0 : 1;
166
167 return count;
168}
169#endif
170
171static DEVICE_ATTR(partition, S_IRUGO, part_partition_show, NULL);
172static DEVICE_ATTR(start, S_IRUGO, part_start_show, NULL);
173static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
174static DEVICE_ATTR(ro, S_IRUGO, part_ro_show, NULL);
175static DEVICE_ATTR(alignment_offset, S_IRUGO, part_alignment_offset_show, NULL);
176static DEVICE_ATTR(discard_alignment, S_IRUGO, part_discard_alignment_show,
177 NULL);
178static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
179static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL);
180#ifdef CONFIG_FAIL_MAKE_REQUEST
181static struct device_attribute dev_attr_fail =
182 __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
183#endif
184
185static struct attribute *part_attrs[] = {
186 &dev_attr_partition.attr,
187 &dev_attr_start.attr,
188 &dev_attr_size.attr,
189 &dev_attr_ro.attr,
190 &dev_attr_alignment_offset.attr,
191 &dev_attr_discard_alignment.attr,
192 &dev_attr_stat.attr,
193 &dev_attr_inflight.attr,
194#ifdef CONFIG_FAIL_MAKE_REQUEST
195 &dev_attr_fail.attr,
196#endif
197 NULL
198};
199
200static struct attribute_group part_attr_group = {
201 .attrs = part_attrs,
202};
203
204static const struct attribute_group *part_attr_groups[] = {
205 &part_attr_group,
206#ifdef CONFIG_BLK_DEV_IO_TRACE
207 &blk_trace_attr_group,
208#endif
209 NULL
210};
211
212static void part_release(struct device *dev)
213{
214 struct hd_struct *p = dev_to_part(dev);
Keith Busch2da78092014-08-26 09:05:36 -0600215 blk_free_devt(dev->devt);
Ming Leib54e5ed2015-07-16 11:16:44 +0800216 hd_free_part(p);
Al Viro94ea4152011-09-16 00:45:36 -0400217 kfree(p);
218}
219
San Mehat0d9c51a2016-03-15 14:53:26 -0700220static int part_uevent(struct device *dev, struct kobj_uevent_env *env)
221{
222 struct hd_struct *part = dev_to_part(dev);
223
224 add_uevent_var(env, "PARTN=%u", part->partno);
225 if (part->info && part->info->volname[0])
226 add_uevent_var(env, "PARTNAME=%s", part->info->volname);
227 return 0;
228}
229
Al Viro94ea4152011-09-16 00:45:36 -0400230struct device_type part_type = {
231 .name = "partition",
232 .groups = part_attr_groups,
233 .release = part_release,
San Mehat0d9c51a2016-03-15 14:53:26 -0700234 .uevent = part_uevent,
Al Viro94ea4152011-09-16 00:45:36 -0400235};
236
237static void delete_partition_rcu_cb(struct rcu_head *head)
238{
239 struct hd_struct *part = container_of(head, struct hd_struct, rcu_head);
240
241 part->start_sect = 0;
242 part->nr_sects = 0;
243 part_stat_set_all(part, 0);
244 put_device(part_to_dev(part));
245}
246
Ming Lei6c710132015-07-16 11:16:45 +0800247void __delete_partition(struct percpu_ref *ref)
Al Viro94ea4152011-09-16 00:45:36 -0400248{
Ming Lei6c710132015-07-16 11:16:45 +0800249 struct hd_struct *part = container_of(ref, struct hd_struct, ref);
Al Viro94ea4152011-09-16 00:45:36 -0400250 call_rcu(&part->rcu_head, delete_partition_rcu_cb);
251}
252
253void delete_partition(struct gendisk *disk, int partno)
254{
255 struct disk_part_tbl *ptbl = disk->part_tbl;
256 struct hd_struct *part;
257
258 if (partno >= ptbl->len)
259 return;
260
261 part = ptbl->part[partno];
262 if (!part)
263 return;
264
Al Viro94ea4152011-09-16 00:45:36 -0400265 rcu_assign_pointer(ptbl->part[partno], NULL);
266 rcu_assign_pointer(ptbl->last_lookup, NULL);
267 kobject_put(part->holder_dir);
268 device_del(part_to_dev(part));
269
Ming Lei6c710132015-07-16 11:16:45 +0800270 hd_struct_kill(part);
Al Viro94ea4152011-09-16 00:45:36 -0400271}
272
273static ssize_t whole_disk_show(struct device *dev,
274 struct device_attribute *attr, char *buf)
275{
276 return 0;
277}
278static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH,
279 whole_disk_show, NULL);
280
281struct hd_struct *add_partition(struct gendisk *disk, int partno,
282 sector_t start, sector_t len, int flags,
283 struct partition_meta_info *info)
284{
285 struct hd_struct *p;
286 dev_t devt = MKDEV(0, 0);
287 struct device *ddev = disk_to_dev(disk);
288 struct device *pdev;
289 struct disk_part_tbl *ptbl;
290 const char *dname;
291 int err;
292
293 err = disk_expand_part_tbl(disk, partno);
294 if (err)
295 return ERR_PTR(err);
296 ptbl = disk->part_tbl;
297
298 if (ptbl->part[partno])
299 return ERR_PTR(-EBUSY);
300
301 p = kzalloc(sizeof(*p), GFP_KERNEL);
302 if (!p)
303 return ERR_PTR(-EBUSY);
304
305 if (!init_part_stats(p)) {
306 err = -ENOMEM;
307 goto out_free;
308 }
Vivek Goyalc83f6bf2012-08-01 12:24:18 +0200309
310 seqcount_init(&p->nr_sects_seq);
Al Viro94ea4152011-09-16 00:45:36 -0400311 pdev = part_to_dev(p);
312
313 p->start_sect = start;
314 p->alignment_offset =
315 queue_limit_alignment_offset(&disk->queue->limits, start);
316 p->discard_alignment =
317 queue_limit_discard_alignment(&disk->queue->limits, start);
318 p->nr_sects = len;
319 p->partno = partno;
320 p->policy = get_disk_ro(disk);
321
322 if (info) {
323 struct partition_meta_info *pinfo = alloc_part_info(disk);
324 if (!pinfo)
325 goto out_free_stats;
326 memcpy(pinfo, info, sizeof(*info));
327 p->info = pinfo;
328 }
329
330 dname = dev_name(ddev);
331 if (isdigit(dname[strlen(dname) - 1]))
332 dev_set_name(pdev, "%sp%d", dname, partno);
333 else
334 dev_set_name(pdev, "%s%d", dname, partno);
335
336 device_initialize(pdev);
337 pdev->class = &block_class;
338 pdev->type = &part_type;
339 pdev->parent = ddev;
340
341 err = blk_alloc_devt(p, &devt);
342 if (err)
343 goto out_free_info;
344 pdev->devt = devt;
345
346 /* delay uevent until 'holders' subdir is created */
347 dev_set_uevent_suppress(pdev, 1);
348 err = device_add(pdev);
349 if (err)
350 goto out_put;
351
352 err = -ENOMEM;
353 p->holder_dir = kobject_create_and_add("holders", &pdev->kobj);
354 if (!p->holder_dir)
355 goto out_del;
356
357 dev_set_uevent_suppress(pdev, 0);
358 if (flags & ADDPART_FLAG_WHOLEDISK) {
359 err = device_create_file(pdev, &dev_attr_whole_disk);
360 if (err)
361 goto out_del;
362 }
363
Ming Leib30a3372016-03-30 08:46:31 +0800364 err = hd_ref_init(p);
365 if (err) {
366 if (flags & ADDPART_FLAG_WHOLEDISK)
367 goto out_remove_file;
368 goto out_del;
369 }
370
Al Viro94ea4152011-09-16 00:45:36 -0400371 /* everything is up and running, commence */
372 rcu_assign_pointer(ptbl->part[partno], p);
373
374 /* suppress uevent if the disk suppresses it */
375 if (!dev_get_uevent_suppress(ddev))
376 kobject_uevent(&pdev->kobj, KOBJ_ADD);
Ming Leib30a3372016-03-30 08:46:31 +0800377 return p;
Al Viro94ea4152011-09-16 00:45:36 -0400378
379out_free_info:
380 free_part_info(p);
381out_free_stats:
382 free_part_stats(p);
383out_free:
384 kfree(p);
385 return ERR_PTR(err);
Ming Leib30a3372016-03-30 08:46:31 +0800386out_remove_file:
387 device_remove_file(pdev, &dev_attr_whole_disk);
Al Viro94ea4152011-09-16 00:45:36 -0400388out_del:
389 kobject_put(p->holder_dir);
390 device_del(pdev);
391out_put:
392 put_device(pdev);
393 blk_free_devt(devt);
394 return ERR_PTR(err);
395}
396
397static bool disk_unlock_native_capacity(struct gendisk *disk)
398{
399 const struct block_device_operations *bdops = disk->fops;
400
401 if (bdops->unlock_native_capacity &&
402 !(disk->flags & GENHD_FL_NATIVE_CAPACITY)) {
403 printk(KERN_CONT "enabling native capacity\n");
404 bdops->unlock_native_capacity(disk);
405 disk->flags |= GENHD_FL_NATIVE_CAPACITY;
406 return true;
407 } else {
408 printk(KERN_CONT "truncated\n");
409 return false;
410 }
411}
412
Jun'ichi Nomurafe316bf2012-03-02 10:38:33 +0100413static int drop_partitions(struct gendisk *disk, struct block_device *bdev)
Al Viro94ea4152011-09-16 00:45:36 -0400414{
Al Viro94ea4152011-09-16 00:45:36 -0400415 struct disk_part_iter piter;
416 struct hd_struct *part;
Jun'ichi Nomurafe316bf2012-03-02 10:38:33 +0100417 int res;
Al Viro94ea4152011-09-16 00:45:36 -0400418
Eric Sandeen77032ca2015-11-24 17:30:34 -0600419 if (bdev->bd_part_count || bdev->bd_super)
Al Viro94ea4152011-09-16 00:45:36 -0400420 return -EBUSY;
421 res = invalidate_partition(disk, 0);
422 if (res)
423 return res;
424
425 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
426 while ((part = disk_part_iter_next(&piter)))
427 delete_partition(disk, part->partno);
428 disk_part_iter_exit(&piter);
429
Jun'ichi Nomurafe316bf2012-03-02 10:38:33 +0100430 return 0;
431}
432
433int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
434{
435 struct parsed_partitions *state = NULL;
436 struct hd_struct *part;
437 int p, highest, res;
438rescan:
439 if (state && !IS_ERR(state)) {
Ming Leiac2e5322013-02-27 17:05:19 -0800440 free_partitions(state);
Jun'ichi Nomurafe316bf2012-03-02 10:38:33 +0100441 state = NULL;
442 }
443
444 res = drop_partitions(disk, bdev);
445 if (res)
446 return res;
447
Al Viro94ea4152011-09-16 00:45:36 -0400448 if (disk->fops->revalidate_disk)
449 disk->fops->revalidate_disk(disk);
450 check_disk_size_change(disk, bdev);
451 bdev->bd_invalidated = 0;
452 if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
453 return 0;
454 if (IS_ERR(state)) {
455 /*
456 * I/O error reading the partition table. If any
457 * partition code tried to read beyond EOD, retry
458 * after unlocking native capacity.
459 */
460 if (PTR_ERR(state) == -ENOSPC) {
461 printk(KERN_WARNING "%s: partition table beyond EOD, ",
462 disk->disk_name);
463 if (disk_unlock_native_capacity(disk))
464 goto rescan;
465 }
466 return -EIO;
467 }
468 /*
469 * If any partition code tried to read beyond EOD, try
470 * unlocking native capacity even if partition table is
471 * successfully read as we could be missing some partitions.
472 */
473 if (state->access_beyond_eod) {
474 printk(KERN_WARNING
475 "%s: partition table partially beyond EOD, ",
476 disk->disk_name);
477 if (disk_unlock_native_capacity(disk))
478 goto rescan;
479 }
480
481 /* tell userspace that the media / partition table may have changed */
482 kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
483
484 /* Detect the highest partition number and preallocate
485 * disk->part_tbl. This is an optimization and not strictly
486 * necessary.
487 */
488 for (p = 1, highest = 0; p < state->limit; p++)
489 if (state->parts[p].size)
490 highest = p;
491
492 disk_expand_part_tbl(disk, highest);
493
494 /* add partitions */
495 for (p = 1; p < state->limit; p++) {
496 sector_t size, from;
Al Viro94ea4152011-09-16 00:45:36 -0400497
498 size = state->parts[p].size;
499 if (!size)
500 continue;
501
502 from = state->parts[p].from;
503 if (from >= get_capacity(disk)) {
504 printk(KERN_WARNING
505 "%s: p%d start %llu is beyond EOD, ",
506 disk->disk_name, p, (unsigned long long) from);
507 if (disk_unlock_native_capacity(disk))
508 goto rescan;
509 continue;
510 }
511
512 if (from + size > get_capacity(disk)) {
513 printk(KERN_WARNING
514 "%s: p%d size %llu extends beyond EOD, ",
515 disk->disk_name, p, (unsigned long long) size);
516
517 if (disk_unlock_native_capacity(disk)) {
518 /* free state and restart */
519 goto rescan;
520 } else {
521 /*
522 * we can not ignore partitions of broken tables
523 * created by for example camera firmware, but
524 * we limit them to the end of the disk to avoid
525 * creating invalid block devices
526 */
527 size = get_capacity(disk) - from;
528 }
529 }
530
Al Viro94ea4152011-09-16 00:45:36 -0400531 part = add_partition(disk, p, from, size,
532 state->parts[p].flags,
533 &state->parts[p].info);
534 if (IS_ERR(part)) {
535 printk(KERN_ERR " %s: p%d could not be added: %ld\n",
536 disk->disk_name, p, -PTR_ERR(part));
537 continue;
538 }
539#ifdef CONFIG_BLK_DEV_MD
540 if (state->parts[p].flags & ADDPART_FLAG_RAID)
541 md_autodetect_dev(part_to_dev(part)->devt);
542#endif
543 }
Ming Leiac2e5322013-02-27 17:05:19 -0800544 free_partitions(state);
Al Viro94ea4152011-09-16 00:45:36 -0400545 return 0;
546}
547
Jun'ichi Nomurafe316bf2012-03-02 10:38:33 +0100548int invalidate_partitions(struct gendisk *disk, struct block_device *bdev)
549{
550 int res;
551
552 if (!bdev->bd_invalidated)
553 return 0;
554
555 res = drop_partitions(disk, bdev);
556 if (res)
557 return res;
558
559 set_capacity(disk, 0);
560 check_disk_size_change(disk, bdev);
561 bdev->bd_invalidated = 0;
562 /* tell userspace that the media / partition table may have changed */
563 kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
564
565 return 0;
566}
567
Dan Williamsd1a5f2b42016-01-28 20:25:31 -0800568static struct page *read_pagecache_sector(struct block_device *bdev, sector_t n)
Al Viro94ea4152011-09-16 00:45:36 -0400569{
570 struct address_space *mapping = bdev->bd_inode->i_mapping;
Dan Williamsd1a5f2b42016-01-28 20:25:31 -0800571
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300572 return read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_SHIFT-9)),
573 NULL);
Dan Williamsd1a5f2b42016-01-28 20:25:31 -0800574}
575
576unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
577{
Al Viro94ea4152011-09-16 00:45:36 -0400578 struct page *page;
579
Dan Williamsd1a5f2b42016-01-28 20:25:31 -0800580 /* don't populate page cache for dax capable devices */
581 if (IS_DAX(bdev->bd_inode))
582 page = read_dax_sector(bdev, n);
583 else
584 page = read_pagecache_sector(bdev, n);
585
Al Viro94ea4152011-09-16 00:45:36 -0400586 if (!IS_ERR(page)) {
587 if (PageError(page))
588 goto fail;
589 p->v = page;
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300590 return (unsigned char *)page_address(page) + ((n & ((1 << (PAGE_SHIFT - 9)) - 1)) << 9);
Al Viro94ea4152011-09-16 00:45:36 -0400591fail:
Kirill A. Shutemov09cbfea2016-04-01 15:29:47 +0300592 put_page(page);
Al Viro94ea4152011-09-16 00:45:36 -0400593 }
594 p->v = NULL;
595 return NULL;
596}
597
598EXPORT_SYMBOL(read_dev_sector);