xref: /linux/drivers/mtd/ubi/vmt.c (revision 293d5b43948309434568f4dcbb36cce4c3c51bd5)
1 /*
2  * Copyright (c) International Business Machines Corp., 2006
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation;  either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
12  * the GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17  *
18  * Author: Artem Bityutskiy (Битюцкий Артём)
19  */
20 
21 /*
22  * This file contains implementation of volume creation, deletion, updating and
23  * resizing.
24  */
25 
26 #include <linux/err.h>
27 #include <linux/math64.h>
28 #include <linux/slab.h>
29 #include <linux/export.h>
30 #include "ubi.h"
31 
32 static int self_check_volumes(struct ubi_device *ubi);
33 
34 static ssize_t vol_attribute_show(struct device *dev,
35 				  struct device_attribute *attr, char *buf);
36 
37 /* Device attributes corresponding to files in '/<sysfs>/class/ubi/ubiX_Y' */
38 static struct device_attribute attr_vol_reserved_ebs =
39 	__ATTR(reserved_ebs, S_IRUGO, vol_attribute_show, NULL);
40 static struct device_attribute attr_vol_type =
41 	__ATTR(type, S_IRUGO, vol_attribute_show, NULL);
42 static struct device_attribute attr_vol_name =
43 	__ATTR(name, S_IRUGO, vol_attribute_show, NULL);
44 static struct device_attribute attr_vol_corrupted =
45 	__ATTR(corrupted, S_IRUGO, vol_attribute_show, NULL);
46 static struct device_attribute attr_vol_alignment =
47 	__ATTR(alignment, S_IRUGO, vol_attribute_show, NULL);
48 static struct device_attribute attr_vol_usable_eb_size =
49 	__ATTR(usable_eb_size, S_IRUGO, vol_attribute_show, NULL);
50 static struct device_attribute attr_vol_data_bytes =
51 	__ATTR(data_bytes, S_IRUGO, vol_attribute_show, NULL);
52 static struct device_attribute attr_vol_upd_marker =
53 	__ATTR(upd_marker, S_IRUGO, vol_attribute_show, NULL);
54 
55 /*
56  * "Show" method for files in '/<sysfs>/class/ubi/ubiX_Y/'.
57  *
58  * Consider a situation:
59  * A. process 1 opens a sysfs file related to volume Y, say
60  *    /<sysfs>/class/ubi/ubiX_Y/reserved_ebs;
61  * B. process 2 removes volume Y;
62  * C. process 1 starts reading the /<sysfs>/class/ubi/ubiX_Y/reserved_ebs file;
63  *
64  * In this situation, this function will return %-ENODEV because it will find
65  * out that the volume was removed from the @ubi->volumes array.
66  */
67 static ssize_t vol_attribute_show(struct device *dev,
68 				  struct device_attribute *attr, char *buf)
69 {
70 	int ret;
71 	struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev);
72 	struct ubi_device *ubi;
73 
74 	ubi = ubi_get_device(vol->ubi->ubi_num);
75 	if (!ubi)
76 		return -ENODEV;
77 
78 	spin_lock(&ubi->volumes_lock);
79 	if (!ubi->volumes[vol->vol_id]) {
80 		spin_unlock(&ubi->volumes_lock);
81 		ubi_put_device(ubi);
82 		return -ENODEV;
83 	}
84 	/* Take a reference to prevent volume removal */
85 	vol->ref_count += 1;
86 	spin_unlock(&ubi->volumes_lock);
87 
88 	if (attr == &attr_vol_reserved_ebs)
89 		ret = sprintf(buf, "%d\n", vol->reserved_pebs);
90 	else if (attr == &attr_vol_type) {
91 		const char *tp;
92 
93 		if (vol->vol_type == UBI_DYNAMIC_VOLUME)
94 			tp = "dynamic";
95 		else
96 			tp = "static";
97 		ret = sprintf(buf, "%s\n", tp);
98 	} else if (attr == &attr_vol_name)
99 		ret = sprintf(buf, "%s\n", vol->name);
100 	else if (attr == &attr_vol_corrupted)
101 		ret = sprintf(buf, "%d\n", vol->corrupted);
102 	else if (attr == &attr_vol_alignment)
103 		ret = sprintf(buf, "%d\n", vol->alignment);
104 	else if (attr == &attr_vol_usable_eb_size)
105 		ret = sprintf(buf, "%d\n", vol->usable_leb_size);
106 	else if (attr == &attr_vol_data_bytes)
107 		ret = sprintf(buf, "%lld\n", vol->used_bytes);
108 	else if (attr == &attr_vol_upd_marker)
109 		ret = sprintf(buf, "%d\n", vol->upd_marker);
110 	else
111 		/* This must be a bug */
112 		ret = -EINVAL;
113 
114 	/* We've done the operation, drop volume and UBI device references */
115 	spin_lock(&ubi->volumes_lock);
116 	vol->ref_count -= 1;
117 	ubi_assert(vol->ref_count >= 0);
118 	spin_unlock(&ubi->volumes_lock);
119 	ubi_put_device(ubi);
120 	return ret;
121 }
122 
123 static struct attribute *volume_dev_attrs[] = {
124 	&attr_vol_reserved_ebs.attr,
125 	&attr_vol_type.attr,
126 	&attr_vol_name.attr,
127 	&attr_vol_corrupted.attr,
128 	&attr_vol_alignment.attr,
129 	&attr_vol_usable_eb_size.attr,
130 	&attr_vol_data_bytes.attr,
131 	&attr_vol_upd_marker.attr,
132 	NULL
133 };
134 ATTRIBUTE_GROUPS(volume_dev);
135 
136 /* Release method for volume devices */
137 static void vol_release(struct device *dev)
138 {
139 	struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev);
140 
141 	kfree(vol->eba_tbl);
142 	kfree(vol);
143 }
144 
145 /**
146  * ubi_create_volume - create volume.
147  * @ubi: UBI device description object
148  * @req: volume creation request
149  *
150  * This function creates volume described by @req. If @req->vol_id id
151  * %UBI_VOL_NUM_AUTO, this function automatically assign ID to the new volume
152  * and saves it in @req->vol_id. Returns zero in case of success and a negative
153  * error code in case of failure. Note, the caller has to have the
154  * @ubi->device_mutex locked.
155  */
156 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
157 {
158 	int i, err, vol_id = req->vol_id, do_free = 1;
159 	struct ubi_volume *vol;
160 	struct ubi_vtbl_record vtbl_rec;
161 	dev_t dev;
162 
163 	if (ubi->ro_mode)
164 		return -EROFS;
165 
166 	vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL);
167 	if (!vol)
168 		return -ENOMEM;
169 
170 	spin_lock(&ubi->volumes_lock);
171 	if (vol_id == UBI_VOL_NUM_AUTO) {
172 		/* Find unused volume ID */
173 		dbg_gen("search for vacant volume ID");
174 		for (i = 0; i < ubi->vtbl_slots; i++)
175 			if (!ubi->volumes[i]) {
176 				vol_id = i;
177 				break;
178 			}
179 
180 		if (vol_id == UBI_VOL_NUM_AUTO) {
181 			ubi_err(ubi, "out of volume IDs");
182 			err = -ENFILE;
183 			goto out_unlock;
184 		}
185 		req->vol_id = vol_id;
186 	}
187 
188 	dbg_gen("create device %d, volume %d, %llu bytes, type %d, name %s",
189 		ubi->ubi_num, vol_id, (unsigned long long)req->bytes,
190 		(int)req->vol_type, req->name);
191 
192 	/* Ensure that this volume does not exist */
193 	err = -EEXIST;
194 	if (ubi->volumes[vol_id]) {
195 		ubi_err(ubi, "volume %d already exists", vol_id);
196 		goto out_unlock;
197 	}
198 
199 	/* Ensure that the name is unique */
200 	for (i = 0; i < ubi->vtbl_slots; i++)
201 		if (ubi->volumes[i] &&
202 		    ubi->volumes[i]->name_len == req->name_len &&
203 		    !strcmp(ubi->volumes[i]->name, req->name)) {
204 			ubi_err(ubi, "volume \"%s\" exists (ID %d)",
205 				req->name, i);
206 			goto out_unlock;
207 		}
208 
209 	/* Calculate how many eraseblocks are requested */
210 	vol->usable_leb_size = ubi->leb_size - ubi->leb_size % req->alignment;
211 	vol->reserved_pebs = div_u64(req->bytes + vol->usable_leb_size - 1,
212 				     vol->usable_leb_size);
213 
214 	/* Reserve physical eraseblocks */
215 	if (vol->reserved_pebs > ubi->avail_pebs) {
216 		ubi_err(ubi, "not enough PEBs, only %d available",
217 			ubi->avail_pebs);
218 		if (ubi->corr_peb_count)
219 			ubi_err(ubi, "%d PEBs are corrupted and not used",
220 				ubi->corr_peb_count);
221 		err = -ENOSPC;
222 		goto out_unlock;
223 	}
224 	ubi->avail_pebs -= vol->reserved_pebs;
225 	ubi->rsvd_pebs += vol->reserved_pebs;
226 	spin_unlock(&ubi->volumes_lock);
227 
228 	vol->vol_id    = vol_id;
229 	vol->alignment = req->alignment;
230 	vol->data_pad  = ubi->leb_size % vol->alignment;
231 	vol->vol_type  = req->vol_type;
232 	vol->name_len  = req->name_len;
233 	memcpy(vol->name, req->name, vol->name_len);
234 	vol->ubi = ubi;
235 
236 	/*
237 	 * Finish all pending erases because there may be some LEBs belonging
238 	 * to the same volume ID.
239 	 */
240 	err = ubi_wl_flush(ubi, vol_id, UBI_ALL);
241 	if (err)
242 		goto out_acc;
243 
244 	vol->eba_tbl = kmalloc(vol->reserved_pebs * sizeof(int), GFP_KERNEL);
245 	if (!vol->eba_tbl) {
246 		err = -ENOMEM;
247 		goto out_acc;
248 	}
249 
250 	for (i = 0; i < vol->reserved_pebs; i++)
251 		vol->eba_tbl[i] = UBI_LEB_UNMAPPED;
252 
253 	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
254 		vol->used_ebs = vol->reserved_pebs;
255 		vol->last_eb_bytes = vol->usable_leb_size;
256 		vol->used_bytes =
257 			(long long)vol->used_ebs * vol->usable_leb_size;
258 	} else {
259 		vol->used_ebs = div_u64_rem(vol->used_bytes,
260 					    vol->usable_leb_size,
261 					    &vol->last_eb_bytes);
262 		if (vol->last_eb_bytes != 0)
263 			vol->used_ebs += 1;
264 		else
265 			vol->last_eb_bytes = vol->usable_leb_size;
266 	}
267 
268 	/* Register character device for the volume */
269 	cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
270 	vol->cdev.owner = THIS_MODULE;
271 	dev = MKDEV(MAJOR(ubi->cdev.dev), vol_id + 1);
272 	err = cdev_add(&vol->cdev, dev, 1);
273 	if (err) {
274 		ubi_err(ubi, "cannot add character device");
275 		goto out_mapping;
276 	}
277 
278 	vol->dev.release = vol_release;
279 	vol->dev.parent = &ubi->dev;
280 	vol->dev.devt = dev;
281 	vol->dev.class = &ubi_class;
282 	vol->dev.groups = volume_dev_groups;
283 
284 	dev_set_name(&vol->dev, "%s_%d", ubi->ubi_name, vol->vol_id);
285 	err = device_register(&vol->dev);
286 	if (err) {
287 		ubi_err(ubi, "cannot register device");
288 		goto out_cdev;
289 	}
290 
291 	/* Fill volume table record */
292 	memset(&vtbl_rec, 0, sizeof(struct ubi_vtbl_record));
293 	vtbl_rec.reserved_pebs = cpu_to_be32(vol->reserved_pebs);
294 	vtbl_rec.alignment     = cpu_to_be32(vol->alignment);
295 	vtbl_rec.data_pad      = cpu_to_be32(vol->data_pad);
296 	vtbl_rec.name_len      = cpu_to_be16(vol->name_len);
297 	if (vol->vol_type == UBI_DYNAMIC_VOLUME)
298 		vtbl_rec.vol_type = UBI_VID_DYNAMIC;
299 	else
300 		vtbl_rec.vol_type = UBI_VID_STATIC;
301 	memcpy(vtbl_rec.name, vol->name, vol->name_len);
302 
303 	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
304 	if (err)
305 		goto out_sysfs;
306 
307 	spin_lock(&ubi->volumes_lock);
308 	ubi->volumes[vol_id] = vol;
309 	ubi->vol_count += 1;
310 	spin_unlock(&ubi->volumes_lock);
311 
312 	ubi_volume_notify(ubi, vol, UBI_VOLUME_ADDED);
313 	self_check_volumes(ubi);
314 	return err;
315 
316 out_sysfs:
317 	/*
318 	 * We have registered our device, we should not free the volume
319 	 * description object in this function in case of an error - it is
320 	 * freed by the release function.
321 	 *
322 	 * Get device reference to prevent the release function from being
323 	 * called just after sysfs has been closed.
324 	 */
325 	do_free = 0;
326 	get_device(&vol->dev);
327 	device_unregister(&vol->dev);
328 out_cdev:
329 	cdev_del(&vol->cdev);
330 out_mapping:
331 	if (do_free)
332 		kfree(vol->eba_tbl);
333 out_acc:
334 	spin_lock(&ubi->volumes_lock);
335 	ubi->rsvd_pebs -= vol->reserved_pebs;
336 	ubi->avail_pebs += vol->reserved_pebs;
337 out_unlock:
338 	spin_unlock(&ubi->volumes_lock);
339 	if (do_free)
340 		kfree(vol);
341 	else
342 		put_device(&vol->dev);
343 	ubi_err(ubi, "cannot create volume %d, error %d", vol_id, err);
344 	return err;
345 }
346 
347 /**
348  * ubi_remove_volume - remove volume.
349  * @desc: volume descriptor
350  * @no_vtbl: do not change volume table if not zero
351  *
352  * This function removes volume described by @desc. The volume has to be opened
353  * in "exclusive" mode. Returns zero in case of success and a negative error
354  * code in case of failure. The caller has to have the @ubi->device_mutex
355  * locked.
356  */
357 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl)
358 {
359 	struct ubi_volume *vol = desc->vol;
360 	struct ubi_device *ubi = vol->ubi;
361 	int i, err, vol_id = vol->vol_id, reserved_pebs = vol->reserved_pebs;
362 
363 	dbg_gen("remove device %d, volume %d", ubi->ubi_num, vol_id);
364 	ubi_assert(desc->mode == UBI_EXCLUSIVE);
365 	ubi_assert(vol == ubi->volumes[vol_id]);
366 
367 	if (ubi->ro_mode)
368 		return -EROFS;
369 
370 	spin_lock(&ubi->volumes_lock);
371 	if (vol->ref_count > 1) {
372 		/*
373 		 * The volume is busy, probably someone is reading one of its
374 		 * sysfs files.
375 		 */
376 		err = -EBUSY;
377 		goto out_unlock;
378 	}
379 	ubi->volumes[vol_id] = NULL;
380 	spin_unlock(&ubi->volumes_lock);
381 
382 	if (!no_vtbl) {
383 		err = ubi_change_vtbl_record(ubi, vol_id, NULL);
384 		if (err)
385 			goto out_err;
386 	}
387 
388 	for (i = 0; i < vol->reserved_pebs; i++) {
389 		err = ubi_eba_unmap_leb(ubi, vol, i);
390 		if (err)
391 			goto out_err;
392 	}
393 
394 	cdev_del(&vol->cdev);
395 	device_unregister(&vol->dev);
396 
397 	spin_lock(&ubi->volumes_lock);
398 	ubi->rsvd_pebs -= reserved_pebs;
399 	ubi->avail_pebs += reserved_pebs;
400 	ubi_update_reserved(ubi);
401 	ubi->vol_count -= 1;
402 	spin_unlock(&ubi->volumes_lock);
403 
404 	ubi_volume_notify(ubi, vol, UBI_VOLUME_REMOVED);
405 	if (!no_vtbl)
406 		self_check_volumes(ubi);
407 
408 	return 0;
409 
410 out_err:
411 	ubi_err(ubi, "cannot remove volume %d, error %d", vol_id, err);
412 	spin_lock(&ubi->volumes_lock);
413 	ubi->volumes[vol_id] = vol;
414 out_unlock:
415 	spin_unlock(&ubi->volumes_lock);
416 	return err;
417 }
418 
419 /**
420  * ubi_resize_volume - re-size volume.
421  * @desc: volume descriptor
422  * @reserved_pebs: new size in physical eraseblocks
423  *
424  * This function re-sizes the volume and returns zero in case of success, and a
425  * negative error code in case of failure. The caller has to have the
426  * @ubi->device_mutex locked.
427  */
428 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs)
429 {
430 	int i, err, pebs, *new_mapping;
431 	struct ubi_volume *vol = desc->vol;
432 	struct ubi_device *ubi = vol->ubi;
433 	struct ubi_vtbl_record vtbl_rec;
434 	int vol_id = vol->vol_id;
435 
436 	if (ubi->ro_mode)
437 		return -EROFS;
438 
439 	dbg_gen("re-size device %d, volume %d to from %d to %d PEBs",
440 		ubi->ubi_num, vol_id, vol->reserved_pebs, reserved_pebs);
441 
442 	if (vol->vol_type == UBI_STATIC_VOLUME &&
443 	    reserved_pebs < vol->used_ebs) {
444 		ubi_err(ubi, "too small size %d, %d LEBs contain data",
445 			reserved_pebs, vol->used_ebs);
446 		return -EINVAL;
447 	}
448 
449 	/* If the size is the same, we have nothing to do */
450 	if (reserved_pebs == vol->reserved_pebs)
451 		return 0;
452 
453 	new_mapping = kmalloc(reserved_pebs * sizeof(int), GFP_KERNEL);
454 	if (!new_mapping)
455 		return -ENOMEM;
456 
457 	for (i = 0; i < reserved_pebs; i++)
458 		new_mapping[i] = UBI_LEB_UNMAPPED;
459 
460 	spin_lock(&ubi->volumes_lock);
461 	if (vol->ref_count > 1) {
462 		spin_unlock(&ubi->volumes_lock);
463 		err = -EBUSY;
464 		goto out_free;
465 	}
466 	spin_unlock(&ubi->volumes_lock);
467 
468 	/* Reserve physical eraseblocks */
469 	pebs = reserved_pebs - vol->reserved_pebs;
470 	if (pebs > 0) {
471 		spin_lock(&ubi->volumes_lock);
472 		if (pebs > ubi->avail_pebs) {
473 			ubi_err(ubi, "not enough PEBs: requested %d, available %d",
474 				pebs, ubi->avail_pebs);
475 			if (ubi->corr_peb_count)
476 				ubi_err(ubi, "%d PEBs are corrupted and not used",
477 					ubi->corr_peb_count);
478 			spin_unlock(&ubi->volumes_lock);
479 			err = -ENOSPC;
480 			goto out_free;
481 		}
482 		ubi->avail_pebs -= pebs;
483 		ubi->rsvd_pebs += pebs;
484 		for (i = 0; i < vol->reserved_pebs; i++)
485 			new_mapping[i] = vol->eba_tbl[i];
486 		kfree(vol->eba_tbl);
487 		vol->eba_tbl = new_mapping;
488 		spin_unlock(&ubi->volumes_lock);
489 	}
490 
491 	if (pebs < 0) {
492 		for (i = 0; i < -pebs; i++) {
493 			err = ubi_eba_unmap_leb(ubi, vol, reserved_pebs + i);
494 			if (err)
495 				goto out_acc;
496 		}
497 		spin_lock(&ubi->volumes_lock);
498 		ubi->rsvd_pebs += pebs;
499 		ubi->avail_pebs -= pebs;
500 		ubi_update_reserved(ubi);
501 		for (i = 0; i < reserved_pebs; i++)
502 			new_mapping[i] = vol->eba_tbl[i];
503 		kfree(vol->eba_tbl);
504 		vol->eba_tbl = new_mapping;
505 		spin_unlock(&ubi->volumes_lock);
506 	}
507 
508 	/*
509 	 * When we shrink a volume we have to flush all pending (erase) work.
510 	 * Otherwise it can happen that upon next attach UBI finds a LEB with
511 	 * lnum > highest_lnum and refuses to attach.
512 	 */
513 	if (pebs < 0) {
514 		err = ubi_wl_flush(ubi, vol_id, UBI_ALL);
515 		if (err)
516 			goto out_acc;
517 	}
518 
519 	/* Change volume table record */
520 	vtbl_rec = ubi->vtbl[vol_id];
521 	vtbl_rec.reserved_pebs = cpu_to_be32(reserved_pebs);
522 	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
523 	if (err)
524 		goto out_acc;
525 
526 	vol->reserved_pebs = reserved_pebs;
527 	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
528 		vol->used_ebs = reserved_pebs;
529 		vol->last_eb_bytes = vol->usable_leb_size;
530 		vol->used_bytes =
531 			(long long)vol->used_ebs * vol->usable_leb_size;
532 	}
533 
534 	ubi_volume_notify(ubi, vol, UBI_VOLUME_RESIZED);
535 	self_check_volumes(ubi);
536 	return err;
537 
538 out_acc:
539 	if (pebs > 0) {
540 		spin_lock(&ubi->volumes_lock);
541 		ubi->rsvd_pebs -= pebs;
542 		ubi->avail_pebs += pebs;
543 		spin_unlock(&ubi->volumes_lock);
544 	}
545 out_free:
546 	kfree(new_mapping);
547 	return err;
548 }
549 
550 /**
551  * ubi_rename_volumes - re-name UBI volumes.
552  * @ubi: UBI device description object
553  * @rename_list: list of &struct ubi_rename_entry objects
554  *
555  * This function re-names or removes volumes specified in the re-name list.
556  * Returns zero in case of success and a negative error code in case of
557  * failure.
558  */
559 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list)
560 {
561 	int err;
562 	struct ubi_rename_entry *re;
563 
564 	err = ubi_vtbl_rename_volumes(ubi, rename_list);
565 	if (err)
566 		return err;
567 
568 	list_for_each_entry(re, rename_list, list) {
569 		if (re->remove) {
570 			err = ubi_remove_volume(re->desc, 1);
571 			if (err)
572 				break;
573 		} else {
574 			struct ubi_volume *vol = re->desc->vol;
575 
576 			spin_lock(&ubi->volumes_lock);
577 			vol->name_len = re->new_name_len;
578 			memcpy(vol->name, re->new_name, re->new_name_len + 1);
579 			spin_unlock(&ubi->volumes_lock);
580 			ubi_volume_notify(ubi, vol, UBI_VOLUME_RENAMED);
581 		}
582 	}
583 
584 	if (!err)
585 		self_check_volumes(ubi);
586 	return err;
587 }
588 
589 /**
590  * ubi_add_volume - add volume.
591  * @ubi: UBI device description object
592  * @vol: volume description object
593  *
594  * This function adds an existing volume and initializes all its data
595  * structures. Returns zero in case of success and a negative error code in
596  * case of failure.
597  */
598 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol)
599 {
600 	int err, vol_id = vol->vol_id;
601 	dev_t dev;
602 
603 	dbg_gen("add volume %d", vol_id);
604 
605 	/* Register character device for the volume */
606 	cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
607 	vol->cdev.owner = THIS_MODULE;
608 	dev = MKDEV(MAJOR(ubi->cdev.dev), vol->vol_id + 1);
609 	err = cdev_add(&vol->cdev, dev, 1);
610 	if (err) {
611 		ubi_err(ubi, "cannot add character device for volume %d, error %d",
612 			vol_id, err);
613 		return err;
614 	}
615 
616 	vol->dev.release = vol_release;
617 	vol->dev.parent = &ubi->dev;
618 	vol->dev.devt = dev;
619 	vol->dev.class = &ubi_class;
620 	vol->dev.groups = volume_dev_groups;
621 	dev_set_name(&vol->dev, "%s_%d", ubi->ubi_name, vol->vol_id);
622 	err = device_register(&vol->dev);
623 	if (err)
624 		goto out_cdev;
625 
626 	self_check_volumes(ubi);
627 	return err;
628 
629 out_cdev:
630 	cdev_del(&vol->cdev);
631 	return err;
632 }
633 
634 /**
635  * ubi_free_volume - free volume.
636  * @ubi: UBI device description object
637  * @vol: volume description object
638  *
639  * This function frees all resources for volume @vol but does not remove it.
640  * Used only when the UBI device is detached.
641  */
642 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol)
643 {
644 	dbg_gen("free volume %d", vol->vol_id);
645 
646 	ubi->volumes[vol->vol_id] = NULL;
647 	cdev_del(&vol->cdev);
648 	device_unregister(&vol->dev);
649 }
650 
651 /**
652  * self_check_volume - check volume information.
653  * @ubi: UBI device description object
654  * @vol_id: volume ID
655  *
656  * Returns zero if volume is all right and a a negative error code if not.
657  */
658 static int self_check_volume(struct ubi_device *ubi, int vol_id)
659 {
660 	int idx = vol_id2idx(ubi, vol_id);
661 	int reserved_pebs, alignment, data_pad, vol_type, name_len, upd_marker;
662 	const struct ubi_volume *vol;
663 	long long n;
664 	const char *name;
665 
666 	spin_lock(&ubi->volumes_lock);
667 	reserved_pebs = be32_to_cpu(ubi->vtbl[vol_id].reserved_pebs);
668 	vol = ubi->volumes[idx];
669 
670 	if (!vol) {
671 		if (reserved_pebs) {
672 			ubi_err(ubi, "no volume info, but volume exists");
673 			goto fail;
674 		}
675 		spin_unlock(&ubi->volumes_lock);
676 		return 0;
677 	}
678 
679 	if (vol->reserved_pebs < 0 || vol->alignment < 0 || vol->data_pad < 0 ||
680 	    vol->name_len < 0) {
681 		ubi_err(ubi, "negative values");
682 		goto fail;
683 	}
684 	if (vol->alignment > ubi->leb_size || vol->alignment == 0) {
685 		ubi_err(ubi, "bad alignment");
686 		goto fail;
687 	}
688 
689 	n = vol->alignment & (ubi->min_io_size - 1);
690 	if (vol->alignment != 1 && n) {
691 		ubi_err(ubi, "alignment is not multiple of min I/O unit");
692 		goto fail;
693 	}
694 
695 	n = ubi->leb_size % vol->alignment;
696 	if (vol->data_pad != n) {
697 		ubi_err(ubi, "bad data_pad, has to be %lld", n);
698 		goto fail;
699 	}
700 
701 	if (vol->vol_type != UBI_DYNAMIC_VOLUME &&
702 	    vol->vol_type != UBI_STATIC_VOLUME) {
703 		ubi_err(ubi, "bad vol_type");
704 		goto fail;
705 	}
706 
707 	if (vol->upd_marker && vol->corrupted) {
708 		ubi_err(ubi, "update marker and corrupted simultaneously");
709 		goto fail;
710 	}
711 
712 	if (vol->reserved_pebs > ubi->good_peb_count) {
713 		ubi_err(ubi, "too large reserved_pebs");
714 		goto fail;
715 	}
716 
717 	n = ubi->leb_size - vol->data_pad;
718 	if (vol->usable_leb_size != ubi->leb_size - vol->data_pad) {
719 		ubi_err(ubi, "bad usable_leb_size, has to be %lld", n);
720 		goto fail;
721 	}
722 
723 	if (vol->name_len > UBI_VOL_NAME_MAX) {
724 		ubi_err(ubi, "too long volume name, max is %d",
725 			UBI_VOL_NAME_MAX);
726 		goto fail;
727 	}
728 
729 	n = strnlen(vol->name, vol->name_len + 1);
730 	if (n != vol->name_len) {
731 		ubi_err(ubi, "bad name_len %lld", n);
732 		goto fail;
733 	}
734 
735 	n = (long long)vol->used_ebs * vol->usable_leb_size;
736 	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
737 		if (vol->corrupted) {
738 			ubi_err(ubi, "corrupted dynamic volume");
739 			goto fail;
740 		}
741 		if (vol->used_ebs != vol->reserved_pebs) {
742 			ubi_err(ubi, "bad used_ebs");
743 			goto fail;
744 		}
745 		if (vol->last_eb_bytes != vol->usable_leb_size) {
746 			ubi_err(ubi, "bad last_eb_bytes");
747 			goto fail;
748 		}
749 		if (vol->used_bytes != n) {
750 			ubi_err(ubi, "bad used_bytes");
751 			goto fail;
752 		}
753 	} else {
754 		if (vol->used_ebs < 0 || vol->used_ebs > vol->reserved_pebs) {
755 			ubi_err(ubi, "bad used_ebs");
756 			goto fail;
757 		}
758 		if (vol->last_eb_bytes < 0 ||
759 		    vol->last_eb_bytes > vol->usable_leb_size) {
760 			ubi_err(ubi, "bad last_eb_bytes");
761 			goto fail;
762 		}
763 		if (vol->used_bytes < 0 || vol->used_bytes > n ||
764 		    vol->used_bytes < n - vol->usable_leb_size) {
765 			ubi_err(ubi, "bad used_bytes");
766 			goto fail;
767 		}
768 	}
769 
770 	alignment  = be32_to_cpu(ubi->vtbl[vol_id].alignment);
771 	data_pad   = be32_to_cpu(ubi->vtbl[vol_id].data_pad);
772 	name_len   = be16_to_cpu(ubi->vtbl[vol_id].name_len);
773 	upd_marker = ubi->vtbl[vol_id].upd_marker;
774 	name       = &ubi->vtbl[vol_id].name[0];
775 	if (ubi->vtbl[vol_id].vol_type == UBI_VID_DYNAMIC)
776 		vol_type = UBI_DYNAMIC_VOLUME;
777 	else
778 		vol_type = UBI_STATIC_VOLUME;
779 
780 	if (alignment != vol->alignment || data_pad != vol->data_pad ||
781 	    upd_marker != vol->upd_marker || vol_type != vol->vol_type ||
782 	    name_len != vol->name_len || strncmp(name, vol->name, name_len)) {
783 		ubi_err(ubi, "volume info is different");
784 		goto fail;
785 	}
786 
787 	spin_unlock(&ubi->volumes_lock);
788 	return 0;
789 
790 fail:
791 	ubi_err(ubi, "self-check failed for volume %d", vol_id);
792 	if (vol)
793 		ubi_dump_vol_info(vol);
794 	ubi_dump_vtbl_record(&ubi->vtbl[vol_id], vol_id);
795 	dump_stack();
796 	spin_unlock(&ubi->volumes_lock);
797 	return -EINVAL;
798 }
799 
800 /**
801  * self_check_volumes - check information about all volumes.
802  * @ubi: UBI device description object
803  *
804  * Returns zero if volumes are all right and a a negative error code if not.
805  */
806 static int self_check_volumes(struct ubi_device *ubi)
807 {
808 	int i, err = 0;
809 
810 	if (!ubi_dbg_chk_gen(ubi))
811 		return 0;
812 
813 	for (i = 0; i < ubi->vtbl_slots; i++) {
814 		err = self_check_volume(ubi, i);
815 		if (err)
816 			break;
817 	}
818 
819 	return err;
820 }
821