summaryrefslogtreecommitdiffstats
path: root/drivers/mtd/ubi/kapi.c
blob: 4abbe573fa40300e05b26526c030749bd6621759 (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
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
/*
 * Copyright (c) International Business Machines Corp., 2006
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
 * the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Author: Artem Bityutskiy (Битюцкий Артём)
 */

/* This file mostly implements UBI kernel API functions */

#include <linux/module.h>
#include <linux/err.h>
#include <asm/div64.h>
#include "ubi.h"

/**
 * ubi_get_device_info - get information about UBI device.
 * @ubi_num: UBI device number
 * @di: the information is stored here
 *
 * This function returns %0 in case of success, %-EINVAL if the UBI device
 * number is invalid, and %-ENODEV if there is no such UBI device.
 */
int ubi_get_device_info(int ubi_num, struct ubi_device_info *di)
{
	struct ubi_device *ubi;

	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
		return -EINVAL;

	ubi = ubi_get_device(ubi_num);
	if (!ubi)
		return -ENODEV;

	di->ubi_num = ubi->ubi_num;
	di->leb_size = ubi->leb_size;
	di->min_io_size = ubi->min_io_size;
	di->ro_mode = ubi->ro_mode;
	di->cdev = ubi->cdev.dev;

	ubi_put_device(ubi);
	return 0;
}
EXPORT_SYMBOL_GPL(ubi_get_device_info);

/**
 * ubi_get_volume_info - get information about UBI volume.
 * @desc: volume descriptor
 * @vi: the information is stored here
 */
void ubi_get_volume_info(struct ubi_volume_desc *desc,
			 struct ubi_volume_info *vi)
{
	const struct ubi_volume *vol = desc->vol;
	const struct ubi_device *ubi = vol->ubi;

	vi->vol_id = vol->vol_id;
	vi->ubi_num = ubi->ubi_num;
	vi->size = vol->reserved_pebs;
	vi->used_bytes = vol->used_bytes;
	vi->vol_type = vol->vol_type;
	vi->corrupted = vol->corrupted;
	vi->upd_marker = vol->upd_marker;
	vi->alignment = vol->alignment;
	vi->usable_leb_size = vol->usable_leb_size;
	vi->name_len = vol->name_len;
	vi->name = vol->name;
	vi->cdev = vol->cdev.dev;
}
EXPORT_SYMBOL_GPL(ubi_get_volume_info);

/**
 * ubi_open_volume - open UBI volume.
 * @ubi_num: UBI device number
 * @vol_id: volume ID
 * @mode: open mode
 *
 * The @mode parameter specifies if the volume should be opened in read-only
 * mode, read-write mode, or exclusive mode. The exclusive mode guarantees that
 * nobody else will be able to open this volume. UBI allows to have many volume
 * readers and one writer at a time.
 *
 * If a static volume is being opened for the first time since boot, it will be
 * checked by this function, which means it will be fully read and the CRC
 * checksum of each logical eraseblock will be checked.
 *
 * This function returns volume descriptor in case of success and a negative
 * error code in case of failure.
 */
struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode)
{
	int err;
	struct ubi_volume_desc *desc;
	struct ubi_device *ubi;
	struct ubi_volume *vol;

	dbg_gen("open device %d volume %d, mode %d", ubi_num, vol_id, mode);

	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
		return ERR_PTR(-EINVAL);

	if (mode != UBI_READONLY && mode != UBI_READWRITE &&
	    mode != UBI_EXCLUSIVE)
		return ERR_PTR(-EINVAL);

	/*
	 * First of all, we have to get the UBI device to prevent its removal.
	 */
	ubi = ubi_get_device(ubi_num);
	if (!ubi)
		return ERR_PTR(-ENODEV);

	if (vol_id < 0 || vol_id >= ubi->vtbl_slots) {
		err = -EINVAL;
		goto out_put_ubi;
	}

	desc = kmalloc(sizeof(struct ubi_volume_desc), GFP_KERNEL);
	if (!desc) {
		err = -ENOMEM;
		goto out_put_ubi;
	}

	err = -ENODEV;
	if (!try_module_get(THIS_MODULE))
		goto out_free;

	spin_lock(&ubi->volumes_lock);
	vol = ubi->volumes[vol_id];
	if (!vol)
		goto out_unlock;

	err = -EBUSY;
	switch (mode) {
	case UBI_READONLY:
		if (vol->exclusive)
			goto out_unlock;
		vol->readers += 1;
		break;

	case UBI_READWRITE:
		if (vol->exclusive || vol->writers > 0)
			goto out_unlock;
		vol->writers += 1;
		break;

	case UBI_EXCLUSIVE:
		if (vol->exclusive || vol->writers || vol->readers)
			goto out_unlock;
		vol->exclusive = 1;
		break;
	}
	get_device(&vol->dev);
	vol->ref_count += 1;
	spin_unlock(&ubi->volumes_lock);

	desc->vol = vol;
	desc->mode = mode;

	mutex_lock(&ubi->ckvol_mutex);
	if (!vol->checked) {
		/* This is the first open - check the volume */
		err = ubi_check_volume(ubi, vol_id);
		if (err < 0) {
			mutex_unlock(&ubi->ckvol_mutex);
			ubi_close_volume(desc);
			return ERR_PTR(err);
		}
		if (err == 1) {
			ubi_warn("volume %d on UBI device %d is corrupted",
				 vol_id, ubi->ubi_num);
			vol->corrupted = 1;
		}
		vol->checked = 1;
	}
	mutex_unlock(&ubi->ckvol_mutex);

	return desc;

out_unlock:
	spin_unlock(&ubi->volumes_lock);
	module_put(THIS_MODULE);
out_free:
	kfree(desc);
out_put_ubi:
	ubi_put_device(ubi);
	return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(ubi_open_volume);

/**
 * ubi_open_volume_nm - open UBI volume by name.
 * @ubi_num: UBI device number
 * @name: volume name
 * @mode: open mode
 *
 * This function is similar to 'ubi_open_volume()', but opens a volume by name.
 */
struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
					   int mode)
{
	int i, vol_id = -1, len;
	struct ubi_device *ubi;
	struct ubi_volume_desc *ret;

	dbg_gen("open volume %s, mode %d", name, mode);

	if (!name)
		return ERR_PTR(-EINVAL);

	len = strnlen(name, UBI_VOL_NAME_MAX + 1);
	if (len > UBI_VOL_NAME_MAX)
		return ERR_PTR(-EINVAL);

	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
		return ERR_PTR(-EINVAL);

	ubi = ubi_get_device(ubi_num);
	if (!ubi)
		return ERR_PTR(-ENODEV);

	spin_lock(&ubi->volumes_lock);
	/* Walk all volumes of this UBI device */
	for (i = 0; i < ubi->vtbl_slots; i++) {
		struct ubi_volume *vol = ubi->volumes[i];

		if (vol && len == vol->name_len && !strcmp(name, vol->name)) {
			vol_id = i;
			break;
		}
	}
	spin_unlock(&ubi->volumes_lock);

	if (vol_id >= 0)
		ret = ubi_open_volume(ubi_num, vol_id, mode);
	else
		ret = ERR_PTR(-ENODEV);

	/*
	 * We should put the UBI device even in case of success, because
	 * 'ubi_open_volume()' took a reference as well.
	 */
	ubi_put_device(ubi);
	return ret;
}
EXPORT_SYMBOL_GPL(ubi_open_volume_nm);

/**
 * ubi_close_volume - close UBI volume.
 * @desc: volume descriptor
 */
void ubi_close_volume(struct ubi_volume_desc *desc)
{
	struct ubi_volume *vol = desc->vol;
	struct ubi_device *ubi = vol->ubi;

	dbg_gen("close volume %d, mode %d", vol->vol_id, desc->mode);

	spin_lock(&ubi->volumes_lock);
	switch (desc->mode) {
	case UBI_READONLY:
		vol->readers -= 1;
		break;
	case UBI_READWRITE:
		vol->writers -= 1;
		break;
	case UBI_EXCLUSIVE:
		vol->exclusive = 0;
	}
	vol->ref_count -= 1;
	spin_unlock(&ubi->volumes_lock);

	kfree(desc);
	put_device(&vol->dev);
	ubi_put_device(ubi);
	module_put(THIS_MODULE);
}
EXPORT_SYMBOL_GPL(ubi_close_volume);

/**
 * ubi_leb_read - read data.
 * @desc: volume descriptor
 * @lnum: logical eraseblock number to read from
 * @buf: buffer where to store the read data
 * @offset: offset within the logical eraseblock to read from
 * @len: how many bytes to read
 * @check: whether UBI has to check the read data's CRC or not.
 *
 * This function reads data from offset @offset of logical eraseblock @lnum and
 * stores the data at @buf. When reading from static volumes, @check specifies
 * whether the data has to be checked or not. If yes, the whole logical
 * eraseblock will be read and its CRC checksum will be checked (i.e., the CRC
 * checksum is per-eraseblock). So checking may substantially slow down the
 * read speed. The @check argument is ignored for dynamic volumes.
 *
 * In case of success, this function returns zero. In case of failure, this
 * function returns a negative error code.
 *
 * %-EBADMSG error code is returned:
 * o for both static and dynamic volumes if MTD driver has detected a data
 *   integrity problem (unrecoverable ECC checksum mismatch in case of NAND);
 * o for static volumes in case of data CRC mismatch.
 *
 * If the volume is damaged because of an interrupted update this function just
 * returns immediately with %-EBADF error code.
 */
int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
		 int len, int check)
{
	struct ubi_volume *vol = desc->vol;
	struct ubi_device *ubi = vol->ubi;
	int err, vol_id = vol->vol_id;

	dbg_gen("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset);

	if (vol_id < 0 || vol_id >= ubi->vtbl_slots || lnum < 0 ||
	    lnum >= vol->used_ebs || offset < 0 || len < 0 ||
	    offset + len > vol->usable_leb_size)
		return -EINVAL;

	if (vol->vol_type == UBI_STATIC_VOLUME) {
		if (vol->used_ebs == 0)
			/* Empty static UBI volume */
			return 0;
		if (lnum == vol->used_ebs - 1 &&
		    offset + len > vol->last_eb_bytes)
			return -EINVAL;
	}

	if (vol->upd_marker)
		return -EBADF;
	if (len == 0)
		return 0;

	err = ubi_eba_read_leb(ubi, vol, lnum, buf, offset, len, check);
	if (err && err == -EBADMSG && vol->vol_type == UBI_STATIC_VOLUME) {
		ubi_warn("mark volume %d as corrupted", vol_id);
		vol->corrupted = 1;
	}

	return err;
}
EXPORT_SYMBOL_GPL(ubi_leb_read);

/**
 * ubi_leb_write - write data.
 * @desc: volume descriptor
 * @lnum: logical eraseblock number to write to
 * @buf: data to write
 * @offset: offset within the logical eraseblock where to write
 * @len: how many bytes to write
 * @dtype: expected data type
 *
 * This function writes @len bytes of data from @buf to offset @offset of
 * logical eraseblock @lnum. The @dtype argument describes expected lifetime of
 * the data.
 *
 * This function takes care of physical eraseblock write failures. If write to
 * the physical eraseblock write operation fails, the logical eraseblock is
 * re-mapped to another physical eraseblock, the data is recovered, and the
 * write finishes. UBI has a pool of reserved physical eraseblocks for this.
 *
 * If all the data were successfully written, zero is returned. If an error
 * occurred and UBI has not been able to recover from it, this function returns
 * a negative error code. Note, in case of an error, it is possible that
 * something was still written to the flash media, but that may be some
 * garbage.
 *
 * If the volume is damaged because of an interrupted update this function just
 * returns immediately with %-EBADF code.
 */
int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
		  int offset, int len, int dtype)
{
	struct ubi_volume *vol = desc->vol;
	struct ubi_device *ubi = vol->ubi;
	int vol_id = vol->vol_id;

	dbg_gen("write %d bytes to LEB %d:%d:%d", len, vol_id, lnum, offset);

	if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
		return -EINVAL;

	if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
		return -EROFS;

	if (lnum < 0 || lnum >= vol->reserved_pebs || offset < 0 || len < 0 ||
	    offset + len > vol->usable_leb_size ||
	    offset & (ubi->min_io_size - 1) || len & (ubi->min_io_size - 1))
		return -EINVAL;

	if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
	    dtype != UBI_UNKNOWN)
		return -EINVAL;

	if (vol->upd_marker)
		return -EBADF;

	if (len == 0)
		return 0;

	return ubi_eba_write_leb(ubi, vol, lnum, buf, offset, len, dtype);
}
EXPORT_SYMBOL_GPL(ubi_leb_write);

/*
 * ubi_leb_change - change logical eraseblock atomically.
 * @desc: volume descriptor
 * @lnum: logical eraseblock number to change
 * @buf: data to write
 * @len: how many bytes to write
 * @dtype: expected data type
 *
 * This function changes the contents of a logical eraseblock atomically. @buf
 * has to contain new logical eraseblock data, and @len - the length of the
 * data, which has to be aligned. The length may be shorter then the logical
 * eraseblock size, ant the logical eraseblock may be appended to more times
 * later on. This function guarantees that in case of an unclean reboot the old
 * contents is preserved. Returns zero in case of success and a negative error
 * code in case of failure.
 */
int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
		   int len, int dtype)
{
	struct ubi_volume *vol = desc->vol;
	struct ubi_device *ubi = vol->ubi;
	int vol_id = vol->vol_id;

	dbg_gen("atomically write %d bytes to LEB %d:%d", len, vol_id, lnum);

	if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
		return -EINVAL;

	if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
		return -EROFS;

	if (lnum < 0 || lnum >= vol->reserved_pebs || len < 0 ||
	    len > vol->usable_leb_size || len & (ubi->min_io_size - 1))
		return -EINVAL;

	if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
	    dtype != UBI_UNKNOWN)
		return -EINVAL;

	if (vol->upd_marker)
		return -EBADF;

	if (len == 0)
		return 0;

	return ubi_eba_atomic_leb_change(ubi, vol, lnum, buf, len, dtype);
}
EXPORT_SYMBOL_GPL(ubi_leb_change);

/**
 * ubi_leb_erase - erase logical eraseblock.
 * @desc: volume descriptor
 * @lnum: logical eraseblock number
 *
 * This function un-maps logical eraseblock @lnum and synchronously erases the
 * correspondent physical eraseblock. Returns zero in case of success and a
 * negative error code in case of failure.
 *
 * If the volume is damaged because of an interrupted update this function just
 * returns immediately with %-EBADF code.
 */
int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum)
{
	struct ubi_volume *vol = desc->vol;
	struct ubi_device *ubi = vol->ubi;
	int err;

	dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);

	if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
		return -EROFS;

	if (lnum < 0 || lnum >= vol->reserved_pebs)
		return -EINVAL;

	if (vol->upd_marker)
		return -EBADF;

	err = ubi_eba_unmap_leb(ubi, vol, lnum);
	if (err)
		return err;

	return ubi_wl_flush(ubi);
}
EXPORT_SYMBOL_GPL(ubi_leb_erase);

/**
 * ubi_leb_unmap - un-map logical eraseblock.
 * @desc: volume descriptor
 * @lnum: logical eraseblock number
 *
 * This function un-maps logical eraseblock @lnum and schedules the
 * corresponding physical eraseblock for erasure, so that it will eventually be
 * physically erased in background. This operation is much faster then the
 * erase operation.
 *
 * Unlike erase, the un-map operation does not guarantee that the logical
 * eraseblock will contain all 0xFF bytes when UBI is initialized again. For
 * example, if several logical eraseblocks are un-mapped, and an unclean reboot
 * happens after this, the logical eraseblocks will not necessarily be
 * un-mapped again when this MTD device is attached. They may actually be
 * mapped to the same physical eraseblocks again. So, this function has to be
 * used with care.
 *
 * In other words, when un-mapping a logical eraseblock, UBI does not store
 * any information about this on the flash media, it just marks the logical
 * eraseblock as "un-mapped" in RAM. If UBI is detached before the physical
 * eraseblock is physically erased, it will be mapped again to the same logical
 * eraseblock when the MTD device is attached again.
 *
 * The main and obvious use-case of this function is when the contents of a
 * logical eraseblock has to be re-written. Then it is much more efficient to
 * first un-map it, then write new data, rather then first erase it, then write
 * new data. Note, once new data has been written to the logical eraseblock,
 * UBI guarantees that the old contents has gone forever. In other words, if an
 * unclean reboot happens after the logical eraseblock has been un-mapped and
 * then written to, it will contain the last written data.
 *
 * This function returns zero in case of success and a negative error code in
 * case of failure. If the volume is damaged because of an interrupted update
 * this function just returns immediately with %-EBADF code.
 */
int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum)
{
	struct ubi_volume *vol = desc->vol;
	struct ubi_device *ubi = vol->ubi;

	dbg_gen("unmap LEB %d:%d", vol->vol_id, lnum);

	if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
		return -EROFS;

	if (lnum < 0 || lnum >= vol->reserved_pebs)
		return -EINVAL;

	if (vol->upd_marker)
		return -EBADF;

	return ubi_eba_unmap_leb(ubi, vol, lnum);
}
EXPORT_SYMBOL_GPL(ubi_leb_unmap);

/**
 * ubi_leb_map - map logical erasblock to a physical eraseblock.
 * @desc: volume descriptor
 * @lnum: logical eraseblock number
 * @dtype: expected data type
 *
 * This function maps an un-mapped logical eraseblock @lnum to a physical
 * eraseblock. This means, that after a successful invocation of this
 * function the logical eraseblock @lnum will be empty (contain only %0xFF
 * bytes) and be mapped to a physical eraseblock, even if an unclean reboot
 * happens.
 *
 * This function returns zero in case of success, %-EBADF if the volume is
 * damaged because of an interrupted update, %-EBADMSG if the logical
 * eraseblock is already mapped, and other negative error codes in case of
 * other failures.
 */
int ubi_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype)
{
	struct ubi_volume *vol = desc->vol;
	struct ubi_device *ubi = vol->ubi;

	dbg_gen("unmap LEB %d:%d", vol->vol_id, lnum);

	if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
		return -EROFS;

	if (lnum < 0 || lnum >= vol->reserved_pebs)
		return -EINVAL;

	if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
	    dtype != UBI_UNKNOWN)
		return -EINVAL;

	if (vol->upd_marker)
		return -EBADF;

	if (vol->eba_tbl[lnum] >= 0)
		return -EBADMSG;

	return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0, dtype);
}
EXPORT_SYMBOL_GPL(ubi_leb_map);

/**
 * ubi_is_mapped - check if logical eraseblock is mapped.
 * @desc: volume descriptor
 * @lnum: logical eraseblock number
 *
 * This function checks if logical eraseblock @lnum is mapped to a physical
 * eraseblock. If a logical eraseblock is un-mapped, this does not necessarily
 * mean it will still be un-mapped after the UBI device is re-attached. The
 * logical eraseblock may become mapped to the physical eraseblock it was last
 * mapped to.
 *
 * This function returns %1 if the LEB is mapped, %0 if not, and a negative
 * error code in case of failure. If the volume is damaged because of an
 * interrupted update this function just returns immediately with %-EBADF error
 * code.
 */
int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum)
{
	struct ubi_volume *vol = desc->vol;

	dbg_gen("test LEB %d:%d", vol->vol_id, lnum);

	if (lnum < 0 || lnum >= vol->reserved_pebs)
		return -EINVAL;

	if (vol->upd_marker)
		return -EBADF;

	return vol->eba_tbl[lnum] >= 0;
}
EXPORT_SYMBOL_GPL(ubi_is_mapped);

/**
 * ubi_sync - synchronize UBI device buffers.
 * @ubi_num: UBI device to synchronize
 *
 * The underlying MTD device may cache data in hardware or in software. This
 * function ensures the caches are flushed. Returns zero in case of success and
 * a negative error code in case of failure.
 */
int ubi_sync(int ubi_num)
{
	struct ubi_device *ubi;

	ubi = ubi_get_device(ubi_num);
	if (!ubi)
		return -ENODEV;

	if (ubi->mtd->sync)
		ubi->mtd->sync(ubi->mtd);

	ubi_put_device(ubi);
	return 0;
}
EXPORT_SYMBOL_GPL(ubi_sync);