aboutsummaryrefslogtreecommitdiff
path: root/fs/partitions/check.c
blob: efef715135d34e459ce450eb24ca41e4234cf471 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
/*
 *  fs/partitions/check.c
 *
 *  Code extracted from drivers/block/genhd.c
 *  Copyright (C) 1991-1998  Linus Torvalds
 *  Re-organised Feb 1998 Russell King
 *
 *  We now have independent partition support from the
 *  block drivers, which allows all the partition code to
 *  be grouped in one location, and it to be mostly self
 *  contained.
 *
 *  Added needed MAJORS for new pairs, {hdi,hdj}, {hdk,hdl}
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/kmod.h>
#include <linux/ctype.h>
#include <linux/genhd.h>

#include "check.h"

#include "acorn.h"
#include "amiga.h"
#include "atari.h"
#include "ldm.h"
#include "mac.h"
#include "msdos.h"
#include "osf.h"
#include "sgi.h"
#include "sun.h"
#include "ibm.h"
#include "ultrix.h"
#include "efi.h"
#include "karma.h"
#include "sysv68.h"

#ifdef CONFIG_BLK_DEV_MD
extern void md_autodetect_dev(dev_t dev);
#endif

int warn_no_part = 1; /*This is ugly: should make genhd removable media aware*/

static int (*check_part[])(struct parsed_partitions *, struct block_device *) = {
	/*
	 * Probe partition formats with tables at disk address 0
	 * that also have an ADFS boot block at 0xdc0.
	 */
#ifdef CONFIG_ACORN_PARTITION_ICS
	adfspart_check_ICS,
#endif
#ifdef CONFIG_ACORN_PARTITION_POWERTEC
	adfspart_check_POWERTEC,
#endif
#ifdef CONFIG_ACORN_PARTITION_EESOX
	adfspart_check_EESOX,
#endif

	/*
	 * Now move on to formats that only have partition info at
	 * disk address 0xdc0.  Since these may also have stale
	 * PC/BIOS partition tables, they need to come before
	 * the msdos entry.
	 */
#ifdef CONFIG_ACORN_PARTITION_CUMANA
	adfspart_check_CUMANA,
#endif
#ifdef CONFIG_ACORN_PARTITION_ADFS
	adfspart_check_ADFS,
#endif

#ifdef CONFIG_EFI_PARTITION
	efi_partition,		/* this must come before msdos */
#endif
#ifdef CONFIG_SGI_PARTITION
	sgi_partition,
#endif
#ifdef CONFIG_LDM_PARTITION
	ldm_partition,		/* this must come before msdos */
#endif
#ifdef CONFIG_MSDOS_PARTITION
	msdos_partition,
#endif
#ifdef CONFIG_OSF_PARTITION
	osf_partition,
#endif
#ifdef CONFIG_SUN_PARTITION
	sun_partition,
#endif
#ifdef CONFIG_AMIGA_PARTITION
	amiga_partition,
#endif
#ifdef CONFIG_ATARI_PARTITION
	atari_partition,
#endif
#ifdef CONFIG_MAC_PARTITION
	mac_partition,
#endif
#ifdef CONFIG_ULTRIX_PARTITION
	ultrix_partition,
#endif
#ifdef CONFIG_IBM_PARTITION
	ibm_partition,
#endif
#ifdef CONFIG_KARMA_PARTITION
	karma_partition,
#endif
#ifdef CONFIG_SYSV68_PARTITION
	sysv68_partition,
#endif
	NULL
};
 
/*
 * disk_name() is used by partition check code and the genhd driver.
 * It formats the devicename of the indicated disk into
 * the supplied buffer (of size at least 32), and returns
 * a pointer to that same buffer (for convenience).
 */

char *disk_name(struct gendisk *hd, int part, char *buf)
{
	if (!part)
		snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
	else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
		snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, part);
	else
		snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, part);

	return buf;
}

const char *bdevname(struct block_device *bdev, char *buf)
{
	int part = MINOR(bdev->bd_dev) - bdev->bd_disk->first_minor;
	return disk_name(bdev->bd_disk, part, buf);
}

EXPORT_SYMBOL(bdevname);

/*
 * There's very little reason to use this, you should really
 * have a struct block_device just about everywhere and use
 * bdevname() instead.
 */
const char *__bdevname(dev_t dev, char *buffer)
{
	scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)",
				MAJOR(dev), MINOR(dev));
	return buffer;
}

EXPORT_SYMBOL(__bdevname);

static struct parsed_partitions *
check_partition(struct gendisk *hd, struct block_device *bdev)
{
	struct parsed_partitions *state;
	int i, res, err;

	state = kmalloc(sizeof(struct parsed_partitions), GFP_KERNEL);
	if (!state)
		return NULL;

	disk_name(hd, 0, state->name);
	printk(KERN_INFO " %s:", state->name);
	if (isdigit(state->name[strlen(state->name)-1]))
		sprintf(state->name, "p");

	state->limit = hd->minors;
	i = res = err = 0;
	while (!res && check_part[i]) {
		memset(&state->parts, 0, sizeof(state->parts));
		res = check_part[i++](state, bdev);
		if (res < 0) {
			/* We have hit an I/O error which we don't report now.
		 	* But record it, and let the others do their job.
		 	*/
			err = res;
			res = 0;
		}

	}
	if (res > 0)
		return state;
	if (err)
	/* The partition is unrecognized. So report I/O errors if there were any */
		res = err;
	if (!res)
		printk(" unknown partition table\n");
	else if (warn_no_part)
		printk(" unable to read partition table\n");
	kfree(state);
	return ERR_PTR(res);
}

static ssize_t part_start_show(struct device *dev,
			       struct device_attribute *attr, char *buf)
{
	struct hd_struct *p = dev_to_part(dev);

	return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect);
}

static ssize_t part_size_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
	struct hd_struct *p = dev_to_part(dev);
	return sprintf(buf, "%llu\n",(unsigned long long)p->nr_sects);
}

static ssize_t part_stat_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
	struct hd_struct *p = dev_to_part(dev);

	preempt_disable();
	part_round_stats(p);
	preempt_enable();
	return sprintf(buf,
		"%8lu %8lu %8llu %8u "
		"%8lu %8lu %8llu %8u "
		"%8u %8u %8u"
		"\n",
		part_stat_read(p, ios[READ]),
		part_stat_read(p, merges[READ]),
		(unsigned long long)part_stat_read(p, sectors[READ]),
		jiffies_to_msecs(part_stat_read(p, ticks[READ])),
		part_stat_read(p, ios[WRITE]),
		part_stat_read(p, merges[WRITE]),
		(unsigned long long)part_stat_read(p, sectors[WRITE]),
		jiffies_to_msecs(part_stat_read(p, ticks[WRITE])),
		p->in_flight,
		jiffies_to_msecs(part_stat_read(p, io_ticks)),
		jiffies_to_msecs(part_stat_read(p, time_in_queue)));
}

#ifdef CONFIG_FAIL_MAKE_REQUEST
static ssize_t part_fail_show(struct device *dev,
			      struct device_attribute *attr, char *buf)
{
	struct hd_struct *p = dev_to_part(dev);

	return sprintf(buf, "%d\n", p->make_it_fail);
}

static ssize_t part_fail_store(struct device *dev,
			       struct device_attribute *attr,
			       const char *buf, size_t count)
{
	struct hd_struct *p = dev_to_part(dev);
	int i;

	if (count > 0 && sscanf(buf, "%d", &i) > 0)
		p->make_it_fail = (i == 0) ? 0 : 1;

	return count;
}
#endif

static DEVICE_ATTR(start, S_IRUGO, part_start_show, NULL);
static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
#ifdef CONFIG_FAIL_MAKE_REQUEST
static struct device_attribute dev_attr_fail =
	__ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
#endif

static struct attribute *part_attrs[] = {
	&dev_attr_start.attr,
	&dev_attr_size.attr,
	&dev_attr_stat.attr,
#ifdef CONFIG_FAIL_MAKE_REQUEST
	&dev_attr_fail.attr,
#endif
	NULL
};

static struct attribute_group part_attr_group = {
	.attrs = part_attrs,
};

static struct attribute_group *part_attr_groups[] = {
	&part_attr_group,
	NULL
};

static void part_release(struct device *dev)
{
	struct hd_struct *p = dev_to_part(dev);
	free_part_stats(p);
	kfree(p);
}

struct device_type part_type = {
	.name		= "partition",
	.groups		= part_attr_groups,
	.release	= part_release,
};

static inline void partition_sysfs_add_subdir(struct hd_struct *p)
{
	struct kobject *k;

	k = kobject_get(&p->dev.kobj);
	p->holder_dir = kobject_create_and_add("holders", k);
	kobject_put(k);
}

static inline void disk_sysfs_add_subdirs(struct gendisk *disk)
{
	struct kobject *k;

	k = kobject_get(&disk->dev.kobj);
	disk->holder_dir = kobject_create_and_add("holders", k);
	disk->slave_dir = kobject_create_and_add("slaves", k);
	kobject_put(k);
}

void delete_partition(struct gendisk *disk, int part)
{
	struct hd_struct *p = disk->part[part-1];

	if (!p)
		return;
	if (!p->nr_sects)
		return;
	disk->part[part-1] = NULL;
	p->start_sect = 0;
	p->nr_sects = 0;
	part_stat_set_all(p, 0);
	kobject_put(p->holder_dir);
	device_del(&p->dev);
	put_device(&p->dev);
}

static ssize_t whole_disk_show(struct device *dev,
			       struct device_attribute *attr, char *buf)
{
	return 0;
}
static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH,
		   whole_disk_show, NULL);

void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len, int flags)
{
	struct hd_struct *p;
	int err;

	p = kzalloc(sizeof(*p), GFP_KERNEL);
	if (!p)
		return;

	if (!init_part_stats(p)) {
		kfree(p);
		return;
	}
	p->start_sect = start;
	p->nr_sects = len;
	p->partno = part;
	p->policy = disk->policy;

	if (isdigit(disk->dev.bus_id[strlen(disk->dev.bus_id)-1]))
		snprintf(p->dev.bus_id, BUS_ID_SIZE,
		"%sp%d", disk->dev.bus_id, part);
	else
		snprintf(p->dev.bus_id, BUS_ID_SIZE,
			 "%s%d", disk->dev.bus_id, part);

	device_initialize(&p->dev);
	p->dev.devt = MKDEV(disk->major, disk->first_minor + part);
	p->dev.class = &block_class;
	p->dev.type = &part_type;
	p->dev.parent = &disk->dev;
	disk->part[part-1] = p;

	/* delay uevent until 'holders' subdir is created */
	p->dev.uevent_suppress = 1;
	device_add(&p->dev);
	partition_sysfs_add_subdir(p);
	p->dev.uevent_suppress = 0;
	if (flags & ADDPART_FLAG_WHOLEDISK)
		err = device_create_file(&p->dev, &dev_attr_whole_disk);

	/* suppress uevent if the disk supresses it */
	if (!disk->dev.uevent_suppress)
		kobject_uevent(&p->dev.kobj, KOBJ_ADD);
}

/* Not exported, helper to add_disk(). */
void register_disk(struct gendisk *disk)
{
	struct block_device *bdev;
	char *s;
	int i;
	struct hd_struct *p;
	int err;

	disk->dev.parent = disk->driverfs_dev;
	disk->dev.devt = MKDEV(disk->major, disk->first_minor);

	strlcpy(disk->dev.bus_id, disk->disk_name, BUS_ID_SIZE);
	/* ewww... some of these buggers have / in the name... */
	s = strchr(disk->dev.bus_id, '/');
	if (s)
		*s = '!';

	/* delay uevents, until we scanned partition table */
	disk->dev.uevent_suppress = 1;

	if (device_add(&disk->dev))
		return;
#ifndef CONFIG_SYSFS_DEPRECATED
	err = sysfs_create_link(block_depr, &disk->dev.kobj,
				kobject_name(&disk->dev.kobj));
	if (err) {
		device_del(&disk->dev);
		return;
	}
#endif
	disk_sysfs_add_subdirs(disk);

	/* No minors to use for partitions */
	if (disk->minors == 1)
		goto exit;

	/* No such device (e.g., media were just removed) */
	if (!get_capacity(disk))
		goto exit;

	bdev = bdget_disk(disk, 0);
	if (!bdev)
		goto exit;

	bdev->bd_invalidated = 1;
	err = blkdev_get(bdev, FMODE_READ, 0);
	if (err < 0)
		goto exit;
	blkdev_put(bdev);

exit:
	/* announce disk after possible partitions are created */
	disk->dev.uevent_suppress = 0;
	kobject_uevent(&disk->dev.kobj, KOBJ_ADD);

	/* announce possible partitions */
	for (i = 1; i < disk->minors; i++) {
		p = disk->part[i-1];
		if (!p || !p->nr_sects)
			continue;
		kobject_uevent(&p->dev.kobj, KOBJ_ADD);
	}
}

int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
{
	struct parsed_partitions *state;
	int p, res;

	if (bdev->bd_part_count)
		return -EBUSY;
	res = invalidate_partition(disk, 0);
	if (res)
		return res;
	bdev->bd_invalidated = 0;
	for (p = 1; p < disk->minors; p++)
		delete_partition(disk, p);
	if (disk->fops->revalidate_disk)
		disk->fops->revalidate_disk(disk);
	if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
		return 0;
	if (IS_ERR(state))	/* I/O error reading the partition table */
		return -EIO;

	/* tell userspace that the media / partition table may have changed */
	kobject_uevent(&disk->dev.kobj, KOBJ_CHANGE);

	for (p = 1; p < state->limit; p++) {
		sector_t size = state->parts[p].size;
		sector_t from = state->parts[p].from;
		if (!size)
			continue;
		if (from + size > get_capacity(disk)) {
			printk(" %s: p%d exceeds device capacity\n",
				disk->disk_name, p);
		}
		add_partition(disk, p, from, size, state->parts[p].flags);
#ifdef CONFIG_BLK_DEV_MD
		if (state->parts[p].flags & ADDPART_FLAG_RAID)
			md_autodetect_dev(bdev->bd_dev+p);
#endif
	}
	kfree(state);
	return 0;
}

unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
{
	struct address_space *mapping = bdev->bd_inode->i_mapping;
	struct page *page;

	page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
				 NULL);
	if (!IS_ERR(page)) {
		if (PageError(page))
			goto fail;
		p->v = page;
		return (unsigned char *)page_address(page) +  ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9);
fail:
		page_cache_release(page);
	}
	p->v = NULL;
	return NULL;
}

EXPORT_SYMBOL(read_dev_sector);

void del_gendisk(struct gendisk *disk)
{
	int p;

	/* invalidate stuff */
	for (p = disk->minors - 1; p > 0; p--) {
		invalidate_partition(disk, p);
		delete_partition(disk, p);
	}
	invalidate_partition(disk, 0);
	disk->capacity = 0;
	disk->flags &= ~GENHD_FL_UP;
	unlink_gendisk(disk);
	disk_stat_set_all(disk, 0);
	disk->stamp = 0;

	kobject_put(disk->holder_dir);
	kobject_put(disk->slave_dir);
	disk->driverfs_dev = NULL;
#ifndef CONFIG_SYSFS_DEPRECATED
	sysfs_remove_link(block_depr, disk->dev.bus_id);
#endif
	device_del(&disk->dev);
}