aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/mtd/ubi/vmt.c
blob: 97e093d196725ca2b8529221d5b3a5cbc8e47d72 (plain) (blame)
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
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
/*
 * 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 contains implementation of volume creation, deletion, updating and
 * resizing.
 */

#include <linux/err.h>
#include <linux/math64.h>
#include <linux/slab.h>
#include "ubi.h"

#ifdef CONFIG_MTD_UBI_DEBUG
static int paranoid_check_volumes(struct ubi_device *ubi);
#else
#define paranoid_check_volumes(ubi) 0
#endif

static ssize_t vol_attribute_show(struct device *dev,
				  struct device_attribute *attr, char *buf);

/* Device attributes corresponding to files in '/<sysfs>/class/ubi/ubiX_Y' */
static struct device_attribute attr_vol_reserved_ebs =
	__ATTR(reserved_ebs, S_IRUGO, vol_attribute_show, NULL);
static struct device_attribute attr_vol_type =
	__ATTR(type, S_IRUGO, vol_attribute_show, NULL);
static struct device_attribute attr_vol_name =
	__ATTR(name, S_IRUGO, vol_attribute_show, NULL);
static struct device_attribute attr_vol_corrupted =
	__ATTR(corrupted, S_IRUGO, vol_attribute_show, NULL);
static struct device_attribute attr_vol_alignment =
	__ATTR(alignment, S_IRUGO, vol_attribute_show, NULL);
static struct device_attribute attr_vol_usable_eb_size =
	__ATTR(usable_eb_size, S_IRUGO, vol_attribute_show, NULL);
static struct device_attribute attr_vol_data_bytes =
	__ATTR(data_bytes, S_IRUGO, vol_attribute_show, NULL);
static struct device_attribute attr_vol_upd_marker =
	__ATTR(upd_marker, S_IRUGO, vol_attribute_show, NULL);

/*
 * "Show" method for files in '/<sysfs>/class/ubi/ubiX_Y/'.
 *
 * Consider a situation:
 * A. process 1 opens a sysfs file related to volume Y, say
 *    /<sysfs>/class/ubi/ubiX_Y/reserved_ebs;
 * B. process 2 removes volume Y;
 * C. process 1 starts reading the /<sysfs>/class/ubi/ubiX_Y/reserved_ebs file;
 *
 * In this situation, this function will return %-ENODEV because it will find
 * out that the volume was removed from the @ubi->volumes array.
 */
static ssize_t vol_attribute_show(struct device *dev,
				  struct device_attribute *attr, char *buf)
{
	int ret;
	struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev);
	struct ubi_device *ubi;

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

	spin_lock(&ubi->volumes_lock);
	if (!ubi->volumes[vol->vol_id]) {
		spin_unlock(&ubi->volumes_lock);
		ubi_put_device(ubi);
		return -ENODEV;
	}
	/* Take a reference to prevent volume removal */
	vol->ref_count += 1;
	spin_unlock(&ubi->volumes_lock);

	if (attr == &attr_vol_reserved_ebs)
		ret = sprintf(buf, "%d\n", vol->reserved_pebs);
	else if (attr == &attr_vol_type) {
		const char *tp;

		if (vol->vol_type == UBI_DYNAMIC_VOLUME)
			tp = "dynamic";
		else
			tp = "static";
		ret = sprintf(buf, "%s\n", tp);
	} else if (attr == &attr_vol_name)
		ret = sprintf(buf, "%s\n", vol->name);
	else if (attr == &attr_vol_corrupted)
		ret = sprintf(buf, "%d\n", vol->corrupted);
	else if (attr == &attr_vol_alignment)
		ret = sprintf(buf, "%d\n", vol->alignment);
	else if (attr == &attr_vol_usable_eb_size)
		ret = sprintf(buf, "%d\n", vol->usable_leb_size);
	else if (attr == &attr_vol_data_bytes)
		ret = sprintf(buf, "%lld\n", vol->used_bytes);
	else if (attr == &attr_vol_upd_marker)
		ret = sprintf(buf, "%d\n", vol->upd_marker);
	else
		/* This must be a bug */
		ret = -EINVAL;

	/* We've done the operation, drop volume and UBI device references */
	spin_lock(&ubi->volumes_lock);
	vol->ref_count -= 1;
	ubi_assert(vol->ref_count >= 0);
	spin_unlock(&ubi->volumes_lock);
	ubi_put_device(ubi);
	return ret;
}

/* Release method for volume devices */
static void vol_release(struct device *dev)
{
	struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev);

	kfree(vol->eba_tbl);
	kfree(vol);
}

/**
 * volume_sysfs_init - initialize sysfs for new volume.
 * @ubi: UBI device description object
 * @vol: volume description object
 *
 * This function returns zero in case of success and a negative error code in
 * case of failure.
 *
 * Note, this function does not free allocated resources in case of failure -
 * the caller does it. This is because this would cause release() here and the
 * caller would oops.
 */
static int volume_sysfs_init(struct ubi_device *ubi, struct ubi_volume *vol)
{
	int err;

	err = device_create_file(&vol->dev, &attr_vol_reserved_ebs);
	if (err)
		return err;
	err = device_create_file(&vol->dev, &attr_vol_type);
	if (err)
		return err;
	err = device_create_file(&vol->dev, &attr_vol_name);
	if (err)
		return err;
	err = device_create_file(&vol->dev, &attr_vol_corrupted);
	if (err)
		return err;
	err = device_create_file(&vol->dev, &attr_vol_alignment);
	if (err)
		return err;
	err = device_create_file(&vol->dev, &attr_vol_usable_eb_size);
	if (err)
		return err;
	err = device_create_file(&vol->dev, &attr_vol_data_bytes);
	if (err)
		return err;
	err = device_create_file(&vol->dev, &attr_vol_upd_marker);
	return err;
}

/**
 * volume_sysfs_close - close sysfs for a volume.
 * @vol: volume description object
 */
static void volume_sysfs_close(struct ubi_volume *vol)
{
	device_remove_file(&vol->dev, &attr_vol_upd_marker);
	device_remove_file(&vol->dev, &attr_vol_data_bytes);
	device_remove_file(&vol->dev, &attr_vol_usable_eb_size);
	device_remove_file(&vol->dev, &attr_vol_alignment);
	device_remove_file(&vol->dev, &attr_vol_corrupted);
	device_remove_file(&vol->dev, &attr_vol_name);
	device_remove_file(&vol->dev, &attr_vol_type);
	device_remove_file(&vol->dev, &attr_vol_reserved_ebs);
	device_unregister(&vol->dev);
}

/**
 * ubi_create_volume - create volume.
 * @ubi: UBI device description object
 * @req: volume creation request
 *
 * This function creates volume described by @req. If @req->vol_id id
 * %UBI_VOL_NUM_AUTO, this function automatically assign ID to the new volume
 * and saves it in @req->vol_id. Returns zero in case of success and a negative
 * error code in case of failure. Note, the caller has to have the
 * @ubi->device_mutex locked.
 */
int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
{
	int i, err, vol_id = req->vol_id, do_free = 1;
	struct ubi_volume *vol;
	struct ubi_vtbl_record vtbl_rec;
	dev_t dev;

	if (ubi->ro_mode)
		return -EROFS;

	vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL);
	if (!vol)
		return -ENOMEM;

	spin_lock(&ubi->volumes_lock);
	if (vol_id == UBI_VOL_NUM_AUTO) {
		/* Find unused volume ID */
		dbg_gen("search for vacant volume ID");
		for (i = 0; i < ubi->vtbl_slots; i++)
			if (!ubi->volumes[i]) {
				vol_id = i;
				break;
			}

		if (vol_id == UBI_VOL_NUM_AUTO) {
			dbg_err("out of volume IDs");
			err = -ENFILE;
			goto out_unlock;
		}
		req->vol_id = vol_id;
	}

	dbg_gen("create device %d, volume %d, %llu bytes, type %d, name %s",
		ubi->ubi_num, vol_id, (unsigned long long)req->bytes,
		(int)req->vol_type, req->name);

	/* Ensure that this volume does not exist */
	err = -EEXIST;
	if (ubi->volumes[vol_id]) {
		dbg_err("volume %d already exists", vol_id);
		goto out_unlock;
	}

	/* Ensure that the name is unique */
	for (i = 0; i < ubi->vtbl_slots; i++)
		if (ubi->volumes[i] &&
		    ubi->volumes[i]->name_len == req->name_len &&
		    !strcmp(ubi->volumes[i]->name, req->name)) {
			dbg_err("volume \"%s\" exists (ID %d)", req->name, i);
			goto out_unlock;
		}

	/* Calculate how many eraseblocks are requested */
	vol->usable_leb_size = ubi->leb_size - ubi->leb_size % req->alignment;
	vol->reserved_pebs += div_u64(req->bytes + vol->usable_leb_size - 1,
				      vol->usable_leb_size);

	/* Reserve physical eraseblocks */
	if (vol->reserved_pebs > ubi->avail_pebs) {
		dbg_err("not enough PEBs, only %d available", ubi->avail_pebs);
		if (ubi->corr_peb_count)
			dbg_err("%d PEBs are corrupted and not used",
				ubi->corr_peb_count);
		err = -ENOSPC;
		goto out_unlock;
	}
	ubi->avail_pebs -= vol->reserved_pebs;
	ubi->rsvd_pebs += vol->reserved_pebs;
	spin_unlock(&ubi->volumes_lock);

	vol->vol_id    = vol_id;
	vol->alignment = req->alignment;
	vol->data_pad  = ubi->leb_size % vol->alignment;
	vol->vol_type  = req->vol_type;
	vol->name_len  = req->name_len;
	memcpy(vol->name, req->name, vol->name_len);
	vol->ubi = ubi;

	/*
	 * Finish all pending erases because there may be some LEBs belonging
	 * to the same volume ID.
	 */
	err = ubi_wl_flush(ubi);
	if (err)
		goto out_acc;

	vol->eba_tbl = kmalloc(vol->reserved_pebs * sizeof(int), GFP_KERNEL);
	if (!vol->eba_tbl) {
		err = -ENOMEM;
		goto out_acc;
	}

	for (i = 0; i < vol->reserved_pebs; i++)
		vol->eba_tbl[i] = UBI_LEB_UNMAPPED;

	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
		vol->used_ebs = vol->reserved_pebs;
		vol->last_eb_bytes = vol->usable_leb_size;
		vol->used_bytes =
			(long long)vol->used_ebs * vol->usable_leb_size;
	} else {
		vol->used_ebs = div_u64_rem(vol->used_bytes,
					    vol->usable_leb_size,
					    &vol->last_eb_bytes);
		if (vol->last_eb_bytes != 0)
			vol->used_ebs += 1;
		else
			vol->last_eb_bytes = vol->usable_leb_size;
	}

	/* Register character device for the volume */
	cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
	vol->cdev.owner = THIS_MODULE;
	dev = MKDEV(MAJOR(ubi->cdev.dev), vol_id + 1);
	err = cdev_add(&vol->cdev, dev, 1);
	if (err) {
		ubi_err("cannot add character device");
		goto out_mapping;
	}

	vol->dev.release = vol_release;
	vol->dev.parent = &ubi->dev;
	vol->dev.devt = dev;
	vol->dev.class = ubi_class;

	dev_set_name(&vol->dev, "%s_%d", ubi->ubi_name, vol->vol_id);
	err = device_register(&vol->dev);
	if (err) {
		ubi_err("cannot register device");
		goto out_cdev;
	}

	err = volume_sysfs_init(ubi, vol);
	if (err)
		goto out_sysfs;

	/* Fill volume table record */
	memset(&vtbl_rec, 0, sizeof(struct ubi_vtbl_record));
	vtbl_rec.reserved_pebs = cpu_to_be32(vol->reserved_pebs);
	vtbl_rec.alignment     = cpu_to_be32(vol->alignment);
	vtbl_rec.data_pad      = cpu_to_be32(vol->data_pad);
	vtbl_rec.name_len      = cpu_to_be16(vol->name_len);
	if (vol->vol_type == UBI_DYNAMIC_VOLUME)
		vtbl_rec.vol_type = UBI_VID_DYNAMIC;
	else
		vtbl_rec.vol_type = UBI_VID_STATIC;
	memcpy(vtbl_rec.name, vol->name, vol->name_len);

	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
	if (err)
		goto out_sysfs;

	spin_lock(&ubi->volumes_lock);
	ubi->volumes[vol_id] = vol;
	ubi->vol_count += 1;
	spin_unlock(&ubi->volumes_lock);

	ubi_volume_notify(ubi, vol, UBI_VOLUME_ADDED);
	if (paranoid_check_volumes(ubi))
		dbg_err("check failed while creating volume %d", vol_id);
	return err;

out_sysfs:
	/*
	 * We have registered our device, we should not free the volume
	 * description object in this function in case of an error - it is
	 * freed by the release function.
	 *
	 * Get device reference to prevent the release function from being
	 * called just after sysfs has been closed.
	 */
	do_free = 0;
	get_device(&vol->dev);
	volume_sysfs_close(vol);
out_cdev:
	cdev_del(&vol->cdev);
out_mapping:
	if (do_free)
		kfree(vol->eba_tbl);
out_acc:
	spin_lock(&ubi->volumes_lock);
	ubi->rsvd_pebs -= vol->reserved_pebs;
	ubi->avail_pebs += vol->reserved_pebs;
out_unlock:
	spin_unlock(&ubi->volumes_lock);
	if (do_free)
		kfree(vol);
	else
		put_device(&vol->dev);
	ubi_err("cannot create volume %d, error %d", vol_id, err);
	return err;
}

/**
 * ubi_remove_volume - remove volume.
 * @desc: volume descriptor
 * @no_vtbl: do not change volume table if not zero
 *
 * This function removes volume described by @desc. The volume has to be opened
 * in "exclusive" mode. Returns zero in case of success and a negative error
 * code in case of failure. The caller has to have the @ubi->device_mutex
 * locked.
 */
int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl)
{
	struct ubi_volume *vol = desc->vol;
	struct ubi_device *ubi = vol->ubi;
	int i, err, vol_id = vol->vol_id, reserved_pebs = vol->reserved_pebs;

	dbg_gen("remove device %d, volume %d", ubi->ubi_num, vol_id);
	ubi_assert(desc->mode == UBI_EXCLUSIVE);
	ubi_assert(vol == ubi->volumes[vol_id]);

	if (ubi->ro_mode)
		return -EROFS;

	spin_lock(&ubi->volumes_lock);
	if (vol->ref_count > 1) {
		/*
		 * The volume is busy, probably someone is reading one of its
		 * sysfs files.
		 */
		err = -EBUSY;
		goto out_unlock;
	}
	ubi->volumes[vol_id] = NULL;
	spin_unlock(&ubi->volumes_lock);

	if (!no_vtbl) {
		err = ubi_change_vtbl_record(ubi, vol_id, NULL);
		if (err)
			goto out_err;
	}

	for (i = 0; i < vol->reserved_pebs; i++) {
		err = ubi_eba_unmap_leb(ubi, vol, i);
		if (err)
			goto out_err;
	}

	cdev_del(&vol->cdev);
	volume_sysfs_close(vol);

	spin_lock(&ubi->volumes_lock);
	ubi->rsvd_pebs -= reserved_pebs;
	ubi->avail_pebs += reserved_pebs;
	i = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs;
	if (i > 0) {
		i = ubi->avail_pebs >= i ? i : ubi->avail_pebs;
		ubi->avail_pebs -= i;
		ubi->rsvd_pebs += i;
		ubi->beb_rsvd_pebs += i;
		if (i > 0)
			ubi_msg("reserve more %d PEBs", i);
	}
	ubi->vol_count -= 1;
	spin_unlock(&ubi->volumes_lock);

	ubi_volume_notify(ubi, vol, UBI_VOLUME_REMOVED);
	if (!no_vtbl && paranoid_check_volumes(ubi))
		dbg_err("check failed while removing volume %d", vol_id);

	return err;

out_err:
	ubi_err("cannot remove volume %d, error %d", vol_id, err);
	spin_lock(&ubi->volumes_lock);
	ubi->volumes[vol_id] = vol;
out_unlock:
	spin_unlock(&ubi->volumes_lock);
	return err;
}

/**
 * ubi_resize_volume - re-size volume.
 * @desc: volume descriptor
 * @reserved_pebs: new size in physical eraseblocks
 *
 * This function re-sizes the volume and returns zero in case of success, and a
 * negative error code in case of failure. The caller has to have the
 * @ubi->device_mutex locked.
 */
int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs)
{
	int i, err, pebs, *new_mapping;
	struct ubi_volume *vol = desc->vol;
	struct ubi_device *ubi = vol->ubi;
	struct ubi_vtbl_record vtbl_rec;
	int vol_id = vol->vol_id;

	if (ubi->ro_mode)
		return -EROFS;

	dbg_gen("re-size device %d, volume %d to from %d to %d PEBs",
		ubi->ubi_num, vol_id, vol->reserved_pebs, reserved_pebs);

	if (vol->vol_type == UBI_STATIC_VOLUME &&
	    reserved_pebs < vol->used_ebs) {
		dbg_err("too small size %d, %d LEBs contain data",
			reserved_pebs, vol->used_ebs);
		return -EINVAL;
	}

	/* If the size is the same, we have nothing to do */
	if (reserved_pebs == vol->reserved_pebs)
		return 0;

	new_mapping = kmalloc(reserved_pebs * sizeof(int), GFP_KERNEL);
	if (!new_mapping)
		return -ENOMEM;

	for (i = 0; i < reserved_pebs; i++)
		new_mapping[i] = UBI_LEB_UNMAPPED;

	spin_lock(&ubi->volumes_lock);
	if (vol->ref_count > 1) {
		spin_unlock(&ubi->volumes_lock);
		err = -EBUSY;
		goto out_free;
	}
	spin_unlock(&ubi->volumes_lock);

	/* Reserve physical eraseblocks */
	pebs = reserved_pebs - vol->reserved_pebs;
	if (pebs > 0) {
		spin_lock(&ubi->volumes_lock);
		if (pebs > ubi->avail_pebs) {
			dbg_err("not enough PEBs: requested %d, available %d",
				pebs, ubi->avail_pebs);
			if (ubi->corr_peb_count)
				dbg_err("%d PEBs are corrupted and not used",
					ubi->corr_peb_count);
			spin_unlock(&ubi->volumes_lock);
			err = -ENOSPC;
			goto out_free;
		}
		ubi->avail_pebs -= pebs;
		ubi->rsvd_pebs += pebs;
		for (i = 0; i < vol->reserved_pebs; i++)
			new_mapping[i] = vol->eba_tbl[i];
		kfree(vol->eba_tbl);
		vol->eba_tbl = new_mapping;
		spin_unlock(&ubi->volumes_lock);
	}

	/* Change volume table record */
	memcpy(&vtbl_rec, &ubi->vtbl[vol_id], sizeof(struct ubi_vtbl_record));
	vtbl_rec.reserved_pebs = cpu_to_be32(reserved_pebs);
	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
	if (err)
		goto out_acc;

	if (pebs < 0) {
		for (i = 0; i < -pebs; i++) {
			err = ubi_eba_unmap_leb(ubi, vol, reserved_pebs + i);
			if (err)
				goto out_acc;
		}
		spin_lock(&ubi->volumes_lock);
		ubi->rsvd_pebs += pebs;
		ubi->avail_pebs -= pebs;
		pebs = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs;
		if (pebs > 0) {
			pebs = ubi->avail_pebs >= pebs ? pebs : ubi->avail_pebs;
			ubi->avail_pebs -= pebs;
			ubi->rsvd_pebs += pebs;
			ubi->beb_rsvd_pebs += pebs;
			if (pebs > 0)
				ubi_msg("reserve more %d PEBs", pebs);
		}
		for (i = 0; i < reserved_pebs; i++)
			new_mapping[i] = vol->eba_tbl[i];
		kfree(vol->eba_tbl);
		vol->eba_tbl = new_mapping;
		spin_unlock(&ubi->volumes_lock);
	}

	vol->reserved_pebs = reserved_pebs;
	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
		vol->used_ebs = reserved_pebs;
		vol->last_eb_bytes = vol->usable_leb_size;
		vol->used_bytes =
			(long long)vol->used_ebs * vol->usable_leb_size;
	}

	ubi_volume_notify(ubi, vol, UBI_VOLUME_RESIZED);
	if (paranoid_check_volumes(ubi))
		dbg_err("check failed while re-sizing volume %d", vol_id);
	return err;

out_acc:
	if (pebs > 0) {
		spin_lock(&ubi->volumes_lock);
		ubi->rsvd_pebs -= pebs;
		ubi->avail_pebs += pebs;
		spin_unlock(&ubi->volumes_lock);
	}
out_free:
	kfree(new_mapping);
	return err;
}

/**
 * ubi_rename_volumes - re-name UBI volumes.
 * @ubi: UBI device description object
 * @rename_list: list of &struct ubi_rename_entry objects
 *
 * This function re-names or removes volumes specified in the re-name list.
 * Returns zero in case of success and a negative error code in case of
 * failure.
 */
int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list)
{
	int err;
	struct ubi_rename_entry *re;

	err = ubi_vtbl_rename_volumes(ubi, rename_list);
	if (err)
		return err;

	list_for_each_entry(re, rename_list, list) {
		if (re->remove) {
			err = ubi_remove_volume(re->desc, 1);
			if (err)
				break;
		} else {
			struct ubi_volume *vol = re->desc->vol;

			spin_lock(&ubi->volumes_lock);
			vol->name_len = re->new_name_len;
			memcpy(vol->name, re->new_name, re->new_name_len + 1);
			spin_unlock(&ubi->volumes_lock);
			ubi_volume_notify(ubi, vol, UBI_VOLUME_RENAMED);
		}
	}

	if (!err && paranoid_check_volumes(ubi))
		;
	return err;
}

/**
 * ubi_add_volume - add volume.
 * @ubi: UBI device description object
 * @vol: volume description object
 *
 * This function adds an existing volume and initializes all its data
 * structures. Returns zero in case of success and a negative error code in
 * case of failure.
 */
int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol)
{
	int err, vol_id = vol->vol_id;
	dev_t dev;

	dbg_gen("add volume %d", vol_id);

	/* Register character device for the volume */
	cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
	vol->cdev.owner = THIS_MODULE;
	dev = MKDEV(MAJOR(ubi->cdev.dev), vol->vol_id + 1);
	err = cdev_add(&vol->cdev, dev, 1);
	if (err) {
		ubi_err("cannot add character device for volume %d, error %d",
			vol_id, err);
		return err;
	}

	vol->dev.release = vol_release;
	vol->dev.parent = &ubi->dev;
	vol->dev.devt = dev;
	vol->dev.class = ubi_class;
	dev_set_name(&vol->dev, "%s_%d", ubi->ubi_name, vol->vol_id);
	err = device_register(&vol->dev);
	if (err)
		goto out_cdev;

	err = volume_sysfs_init(ubi, vol);
	if (err) {
		cdev_del(&vol->cdev);
		volume_sysfs_close(vol);
		return err;
	}

	if (paranoid_check_volumes(ubi))
		dbg_err("check failed while adding volume %d", vol_id);
	return err;

out_cdev:
	cdev_del(&vol->cdev);
	return err;
}

/**
 * ubi_free_volume - free volume.
 * @ubi: UBI device description object
 * @vol: volume description object
 *
 * This function frees all resources for volume @vol but does not remove it.
 * Used only when the UBI device is detached.
 */
void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol)
{
	dbg_gen("free volume %d", vol->vol_id);

	ubi->volumes[vol->vol_id] = NULL;
	cdev_del(&vol->cdev);
	volume_sysfs_close(vol);
}

#ifdef CONFIG_MTD_UBI_DEBUG

/**
 * paranoid_check_volume - check volume information.
 * @ubi: UBI device description object
 * @vol_id: volume ID
 *
 * Returns zero if volume is all right and a a negative error code if not.
 */
static int paranoid_check_volume(struct ubi_device *ubi, int vol_id)
{
	int idx = vol_id2idx(ubi, vol_id);
	int reserved_pebs, alignment, data_pad, vol_type, name_len, upd_marker;
	const struct ubi_volume *vol;
	long long n;
	const char *name;

	spin_lock(&ubi->volumes_lock);
	reserved_pebs = be32_to_cpu(ubi->vtbl[vol_id].reserved_pebs);
	vol = ubi->volumes[idx];

	if (!vol) {
		if (reserved_pebs) {
			ubi_err("no volume info, but volume exists");
			goto fail;
		}
		spin_unlock(&ubi->volumes_lock);
		return 0;
	}

	if (vol->reserved_pebs < 0 || vol->alignment < 0 || vol->data_pad < 0 ||
	    vol->name_len < 0) {
		ubi_err("negative values");
		goto fail;
	}
	if (vol->alignment > ubi->leb_size || vol->alignment == 0) {
		ubi_err("bad alignment");
		goto fail;
	}

	n = vol->alignment & (ubi->min_io_size - 1);
	if (vol->alignment != 1 && n) {
		ubi_err("alignment is not multiple of min I/O unit");
		goto fail;
	}

	n = ubi->leb_size % vol->alignment;
	if (vol->data_pad != n) {
		ubi_err("bad data_pad, has to be %lld", n);
		goto fail;
	}

	if (vol->vol_type != UBI_DYNAMIC_VOLUME &&
	    vol->vol_type != UBI_STATIC_VOLUME) {
		ubi_err("bad vol_type");
		goto fail;
	}

	if (vol->upd_marker && vol->corrupted) {
		dbg_err("update marker and corrupted simultaneously");
		goto fail;
	}

	if (vol->reserved_pebs > ubi->good_peb_count) {
		ubi_err("too large reserved_pebs");
		goto fail;
	}

	n = ubi->leb_size - vol->data_pad;
	if (vol->usable_leb_size != ubi->leb_size - vol->data_pad) {
		ubi_err("bad usable_leb_size, has to be %lld", n);
		goto fail;
	}

	if (vol->name_len > UBI_VOL_NAME_MAX) {
		ubi_err("too long volume name, max is %d", UBI_VOL_NAME_MAX);
		goto fail;
	}

	n = strnlen(vol->name, vol->name_len + 1);
	if (n != vol->name_len) {
		ubi_err("bad name_len %lld", n);
		goto fail;
	}

	n = (long long)vol->used_ebs * vol->usable_leb_size;
	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
		if (vol->corrupted) {
			ubi_err("corrupted dynamic volume");
			goto fail;
		}
		if (vol->used_ebs != vol->reserved_pebs) {
			ubi_err("bad used_ebs");
			goto fail;
		}
		if (vol->last_eb_bytes != vol->usable_leb_size) {
			ubi_err("bad last_eb_bytes");
			goto fail;
		}
		if (vol->used_bytes != n) {
			ubi_err("bad used_bytes");
			goto fail;
		}
	} else {
		if (vol->used_ebs < 0 || vol->used_ebs > vol->reserved_pebs) {
			ubi_err("bad used_ebs");
			goto fail;
		}
		if (vol->last_eb_bytes < 0 ||
		    vol->last_eb_bytes > vol->usable_leb_size) {
			ubi_err("bad last_eb_bytes");
			goto fail;
		}
		if (vol->used_bytes < 0 || vol->used_bytes > n ||
		    vol->used_bytes < n - vol->usable_leb_size) {
			ubi_err("bad used_bytes");
			goto fail;
		}
	}

	alignment  = be32_to_cpu(ubi->vtbl[vol_id].alignment);
	data_pad   = be32_to_cpu(ubi->vtbl[vol_id].data_pad);
	name_len   = be16_to_cpu(ubi->vtbl[vol_id].name_len);
	upd_marker = ubi->vtbl[vol_id].upd_marker;
	name       = &ubi->vtbl[vol_id].name[0];
	if (ubi->vtbl[vol_id].vol_type == UBI_VID_DYNAMIC)
		vol_type = UBI_DYNAMIC_VOLUME;
	else
		vol_type = UBI_STATIC_VOLUME;

	if (alignment != vol->alignment || data_pad != vol->data_pad ||
	    upd_marker != vol->upd_marker || vol_type != vol->vol_type ||
	    name_len != vol->name_len || strncmp(name, vol->name, name_len)) {
		ubi_err("volume info is different");
		goto fail;
	}

	spin_unlock(&ubi->volumes_lock);
	return 0;

fail:
	ubi_err("paranoid check failed for volume %d", vol_id);
	if (vol)
		ubi_dbg_dump_vol_info(vol);
	ubi_dbg_dump_vtbl_record(&ubi->vtbl[vol_id], vol_id);
	dump_stack();
	spin_unlock(&ubi->volumes_lock);
	return -EINVAL;
}

/**
 * paranoid_check_volumes - check information about all volumes.
 * @ubi: UBI device description object
 *
 * Returns zero if volumes are all right and a a negative error code if not.
 */
static int paranoid_check_volumes(struct ubi_device *ubi)
{
	int i, err = 0;

	if (!ubi->dbg->chk_gen)
		return 0;

	for (i = 0; i < ubi->vtbl_slots; i++) {
		err = paranoid_check_volume(ubi, i);
		if (err)
			break;
	}

	return err;
}
#endif