xref: /openbmc/linux/drivers/mtd/ubi/vmt.c (revision dfd4f649)
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 	ubi_eba_replace_table(vol, NULL);
142 	ubi_fastmap_destroy_checkmap(vol);
143 	kfree(vol);
144 }
145 
146 /**
147  * ubi_create_volume - create volume.
148  * @ubi: UBI device description object
149  * @req: volume creation request
150  *
151  * This function creates volume described by @req. If @req->vol_id id
152  * %UBI_VOL_NUM_AUTO, this function automatically assign ID to the new volume
153  * and saves it in @req->vol_id. Returns zero in case of success and a negative
154  * error code in case of failure. Note, the caller has to have the
155  * @ubi->device_mutex locked.
156  */
157 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
158 {
159 	int i, err, vol_id = req->vol_id;
160 	struct ubi_volume *vol;
161 	struct ubi_vtbl_record vtbl_rec;
162 	struct ubi_eba_table *eba_tbl = NULL;
163 
164 	if (ubi->ro_mode)
165 		return -EROFS;
166 
167 	vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL);
168 	if (!vol)
169 		return -ENOMEM;
170 
171 	device_initialize(&vol->dev);
172 	vol->dev.release = vol_release;
173 	vol->dev.parent = &ubi->dev;
174 	vol->dev.class = &ubi_class;
175 	vol->dev.groups = volume_dev_groups;
176 
177 	if (req->flags & UBI_VOL_SKIP_CRC_CHECK_FLG)
178 		vol->skip_check = 1;
179 
180 	spin_lock(&ubi->volumes_lock);
181 	if (vol_id == UBI_VOL_NUM_AUTO) {
182 		/* Find unused volume ID */
183 		dbg_gen("search for vacant volume ID");
184 		for (i = 0; i < ubi->vtbl_slots; i++)
185 			if (!ubi->volumes[i]) {
186 				vol_id = i;
187 				break;
188 			}
189 
190 		if (vol_id == UBI_VOL_NUM_AUTO) {
191 			ubi_err(ubi, "out of volume IDs");
192 			err = -ENFILE;
193 			goto out_unlock;
194 		}
195 		req->vol_id = vol_id;
196 	}
197 
198 	dbg_gen("create device %d, volume %d, %llu bytes, type %d, name %s",
199 		ubi->ubi_num, vol_id, (unsigned long long)req->bytes,
200 		(int)req->vol_type, req->name);
201 
202 	/* Ensure that this volume does not exist */
203 	err = -EEXIST;
204 	if (ubi->volumes[vol_id]) {
205 		ubi_err(ubi, "volume %d already exists", vol_id);
206 		goto out_unlock;
207 	}
208 
209 	/* Ensure that the name is unique */
210 	for (i = 0; i < ubi->vtbl_slots; i++)
211 		if (ubi->volumes[i] &&
212 		    ubi->volumes[i]->name_len == req->name_len &&
213 		    !strcmp(ubi->volumes[i]->name, req->name)) {
214 			ubi_err(ubi, "volume \"%s\" exists (ID %d)",
215 				req->name, i);
216 			goto out_unlock;
217 		}
218 
219 	/* Calculate how many eraseblocks are requested */
220 	vol->usable_leb_size = ubi->leb_size - ubi->leb_size % req->alignment;
221 	vol->reserved_pebs = div_u64(req->bytes + vol->usable_leb_size - 1,
222 				     vol->usable_leb_size);
223 
224 	/* Reserve physical eraseblocks */
225 	if (vol->reserved_pebs > ubi->avail_pebs) {
226 		ubi_err(ubi, "not enough PEBs, only %d available",
227 			ubi->avail_pebs);
228 		if (ubi->corr_peb_count)
229 			ubi_err(ubi, "%d PEBs are corrupted and not used",
230 				ubi->corr_peb_count);
231 		err = -ENOSPC;
232 		goto out_unlock;
233 	}
234 	ubi->avail_pebs -= vol->reserved_pebs;
235 	ubi->rsvd_pebs += vol->reserved_pebs;
236 	spin_unlock(&ubi->volumes_lock);
237 
238 	vol->vol_id    = vol_id;
239 	vol->alignment = req->alignment;
240 	vol->data_pad  = ubi->leb_size % vol->alignment;
241 	vol->vol_type  = req->vol_type;
242 	vol->name_len  = req->name_len;
243 	memcpy(vol->name, req->name, vol->name_len);
244 	vol->ubi = ubi;
245 
246 	/*
247 	 * Finish all pending erases because there may be some LEBs belonging
248 	 * to the same volume ID.
249 	 */
250 	err = ubi_wl_flush(ubi, vol_id, UBI_ALL);
251 	if (err)
252 		goto out_acc;
253 
254 	eba_tbl = ubi_eba_create_table(vol, vol->reserved_pebs);
255 	if (IS_ERR(eba_tbl)) {
256 		err = PTR_ERR(eba_tbl);
257 		goto out_acc;
258 	}
259 
260 	ubi_eba_replace_table(vol, eba_tbl);
261 
262 	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
263 		vol->used_ebs = vol->reserved_pebs;
264 		vol->last_eb_bytes = vol->usable_leb_size;
265 		vol->used_bytes =
266 			(long long)vol->used_ebs * vol->usable_leb_size;
267 	} else {
268 		vol->used_ebs = div_u64_rem(vol->used_bytes,
269 					    vol->usable_leb_size,
270 					    &vol->last_eb_bytes);
271 		if (vol->last_eb_bytes != 0)
272 			vol->used_ebs += 1;
273 		else
274 			vol->last_eb_bytes = vol->usable_leb_size;
275 	}
276 
277 	/* Make volume "available" before it becomes accessible via sysfs */
278 	spin_lock(&ubi->volumes_lock);
279 	ubi->volumes[vol_id] = vol;
280 	ubi->vol_count += 1;
281 	spin_unlock(&ubi->volumes_lock);
282 
283 	/* Register character device for the volume */
284 	cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
285 	vol->cdev.owner = THIS_MODULE;
286 
287 	vol->dev.devt = MKDEV(MAJOR(ubi->cdev.dev), vol_id + 1);
288 	dev_set_name(&vol->dev, "%s_%d", ubi->ubi_name, vol->vol_id);
289 	err = cdev_device_add(&vol->cdev, &vol->dev);
290 	if (err) {
291 		ubi_err(ubi, "cannot add device");
292 		goto out_mapping;
293 	}
294 
295 	/* Fill volume table record */
296 	memset(&vtbl_rec, 0, sizeof(struct ubi_vtbl_record));
297 	vtbl_rec.reserved_pebs = cpu_to_be32(vol->reserved_pebs);
298 	vtbl_rec.alignment     = cpu_to_be32(vol->alignment);
299 	vtbl_rec.data_pad      = cpu_to_be32(vol->data_pad);
300 	vtbl_rec.name_len      = cpu_to_be16(vol->name_len);
301 	if (vol->vol_type == UBI_DYNAMIC_VOLUME)
302 		vtbl_rec.vol_type = UBI_VID_DYNAMIC;
303 	else
304 		vtbl_rec.vol_type = UBI_VID_STATIC;
305 
306 	if (vol->skip_check)
307 		vtbl_rec.flags |= UBI_VTBL_SKIP_CRC_CHECK_FLG;
308 
309 	memcpy(vtbl_rec.name, vol->name, vol->name_len);
310 
311 	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
312 	if (err)
313 		goto out_sysfs;
314 
315 	ubi_volume_notify(ubi, vol, UBI_VOLUME_ADDED);
316 	self_check_volumes(ubi);
317 	return err;
318 
319 out_sysfs:
320 	/*
321 	 * We have registered our device, we should not free the volume
322 	 * description object in this function in case of an error - it is
323 	 * freed by the release function.
324 	 */
325 	cdev_device_del(&vol->cdev, &vol->dev);
326 out_mapping:
327 	spin_lock(&ubi->volumes_lock);
328 	ubi->volumes[vol_id] = NULL;
329 	ubi->vol_count -= 1;
330 	spin_unlock(&ubi->volumes_lock);
331 	ubi_eba_destroy_table(eba_tbl);
332 out_acc:
333 	spin_lock(&ubi->volumes_lock);
334 	ubi->rsvd_pebs -= vol->reserved_pebs;
335 	ubi->avail_pebs += vol->reserved_pebs;
336 out_unlock:
337 	spin_unlock(&ubi->volumes_lock);
338 	put_device(&vol->dev);
339 	ubi_err(ubi, "cannot create volume %d, error %d", vol_id, err);
340 	return err;
341 }
342 
343 /**
344  * ubi_remove_volume - remove volume.
345  * @desc: volume descriptor
346  * @no_vtbl: do not change volume table if not zero
347  *
348  * This function removes volume described by @desc. The volume has to be opened
349  * in "exclusive" mode. Returns zero in case of success and a negative error
350  * code in case of failure. The caller has to have the @ubi->device_mutex
351  * locked.
352  */
353 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl)
354 {
355 	struct ubi_volume *vol = desc->vol;
356 	struct ubi_device *ubi = vol->ubi;
357 	int i, err, vol_id = vol->vol_id, reserved_pebs = vol->reserved_pebs;
358 
359 	dbg_gen("remove device %d, volume %d", ubi->ubi_num, vol_id);
360 	ubi_assert(desc->mode == UBI_EXCLUSIVE);
361 	ubi_assert(vol == ubi->volumes[vol_id]);
362 
363 	if (ubi->ro_mode)
364 		return -EROFS;
365 
366 	spin_lock(&ubi->volumes_lock);
367 	if (vol->ref_count > 1) {
368 		/*
369 		 * The volume is busy, probably someone is reading one of its
370 		 * sysfs files.
371 		 */
372 		err = -EBUSY;
373 		goto out_unlock;
374 	}
375 	ubi->volumes[vol_id] = NULL;
376 	spin_unlock(&ubi->volumes_lock);
377 
378 	if (!no_vtbl) {
379 		err = ubi_change_vtbl_record(ubi, vol_id, NULL);
380 		if (err)
381 			goto out_err;
382 	}
383 
384 	for (i = 0; i < vol->reserved_pebs; i++) {
385 		err = ubi_eba_unmap_leb(ubi, vol, i);
386 		if (err)
387 			goto out_err;
388 	}
389 
390 	cdev_device_del(&vol->cdev, &vol->dev);
391 	put_device(&vol->dev);
392 
393 	spin_lock(&ubi->volumes_lock);
394 	ubi->rsvd_pebs -= reserved_pebs;
395 	ubi->avail_pebs += reserved_pebs;
396 	ubi_update_reserved(ubi);
397 	ubi->vol_count -= 1;
398 	spin_unlock(&ubi->volumes_lock);
399 
400 	ubi_volume_notify(ubi, vol, UBI_VOLUME_REMOVED);
401 	if (!no_vtbl)
402 		self_check_volumes(ubi);
403 
404 	return 0;
405 
406 out_err:
407 	ubi_err(ubi, "cannot remove volume %d, error %d", vol_id, err);
408 	spin_lock(&ubi->volumes_lock);
409 	ubi->volumes[vol_id] = vol;
410 out_unlock:
411 	spin_unlock(&ubi->volumes_lock);
412 	return err;
413 }
414 
415 /**
416  * ubi_resize_volume - re-size volume.
417  * @desc: volume descriptor
418  * @reserved_pebs: new size in physical eraseblocks
419  *
420  * This function re-sizes the volume and returns zero in case of success, and a
421  * negative error code in case of failure. The caller has to have the
422  * @ubi->device_mutex locked.
423  */
424 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs)
425 {
426 	int i, err, pebs;
427 	struct ubi_volume *vol = desc->vol;
428 	struct ubi_device *ubi = vol->ubi;
429 	struct ubi_vtbl_record vtbl_rec;
430 	struct ubi_eba_table *new_eba_tbl = NULL;
431 	int vol_id = vol->vol_id;
432 
433 	if (ubi->ro_mode)
434 		return -EROFS;
435 
436 	dbg_gen("re-size device %d, volume %d to from %d to %d PEBs",
437 		ubi->ubi_num, vol_id, vol->reserved_pebs, reserved_pebs);
438 
439 	if (vol->vol_type == UBI_STATIC_VOLUME &&
440 	    reserved_pebs < vol->used_ebs) {
441 		ubi_err(ubi, "too small size %d, %d LEBs contain data",
442 			reserved_pebs, vol->used_ebs);
443 		return -EINVAL;
444 	}
445 
446 	/* If the size is the same, we have nothing to do */
447 	if (reserved_pebs == vol->reserved_pebs)
448 		return 0;
449 
450 	new_eba_tbl = ubi_eba_create_table(vol, reserved_pebs);
451 	if (IS_ERR(new_eba_tbl))
452 		return PTR_ERR(new_eba_tbl);
453 
454 	spin_lock(&ubi->volumes_lock);
455 	if (vol->ref_count > 1) {
456 		spin_unlock(&ubi->volumes_lock);
457 		err = -EBUSY;
458 		goto out_free;
459 	}
460 	spin_unlock(&ubi->volumes_lock);
461 
462 	/* Reserve physical eraseblocks */
463 	pebs = reserved_pebs - vol->reserved_pebs;
464 	if (pebs > 0) {
465 		spin_lock(&ubi->volumes_lock);
466 		if (pebs > ubi->avail_pebs) {
467 			ubi_err(ubi, "not enough PEBs: requested %d, available %d",
468 				pebs, ubi->avail_pebs);
469 			if (ubi->corr_peb_count)
470 				ubi_err(ubi, "%d PEBs are corrupted and not used",
471 					ubi->corr_peb_count);
472 			spin_unlock(&ubi->volumes_lock);
473 			err = -ENOSPC;
474 			goto out_free;
475 		}
476 		ubi->avail_pebs -= pebs;
477 		ubi->rsvd_pebs += pebs;
478 		ubi_eba_copy_table(vol, new_eba_tbl, vol->reserved_pebs);
479 		ubi_eba_replace_table(vol, new_eba_tbl);
480 		spin_unlock(&ubi->volumes_lock);
481 	}
482 
483 	if (pebs < 0) {
484 		for (i = 0; i < -pebs; i++) {
485 			err = ubi_eba_unmap_leb(ubi, vol, reserved_pebs + i);
486 			if (err)
487 				goto out_acc;
488 		}
489 		spin_lock(&ubi->volumes_lock);
490 		ubi->rsvd_pebs += pebs;
491 		ubi->avail_pebs -= pebs;
492 		ubi_update_reserved(ubi);
493 		ubi_eba_copy_table(vol, new_eba_tbl, reserved_pebs);
494 		ubi_eba_replace_table(vol, new_eba_tbl);
495 		spin_unlock(&ubi->volumes_lock);
496 	}
497 
498 	/*
499 	 * When we shrink a volume we have to flush all pending (erase) work.
500 	 * Otherwise it can happen that upon next attach UBI finds a LEB with
501 	 * lnum > highest_lnum and refuses to attach.
502 	 */
503 	if (pebs < 0) {
504 		err = ubi_wl_flush(ubi, vol_id, UBI_ALL);
505 		if (err)
506 			goto out_acc;
507 	}
508 
509 	/* Change volume table record */
510 	vtbl_rec = ubi->vtbl[vol_id];
511 	vtbl_rec.reserved_pebs = cpu_to_be32(reserved_pebs);
512 	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
513 	if (err)
514 		goto out_acc;
515 
516 	vol->reserved_pebs = reserved_pebs;
517 	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
518 		vol->used_ebs = reserved_pebs;
519 		vol->last_eb_bytes = vol->usable_leb_size;
520 		vol->used_bytes =
521 			(long long)vol->used_ebs * vol->usable_leb_size;
522 	}
523 
524 	ubi_volume_notify(ubi, vol, UBI_VOLUME_RESIZED);
525 	self_check_volumes(ubi);
526 	return err;
527 
528 out_acc:
529 	if (pebs > 0) {
530 		spin_lock(&ubi->volumes_lock);
531 		ubi->rsvd_pebs -= pebs;
532 		ubi->avail_pebs += pebs;
533 		spin_unlock(&ubi->volumes_lock);
534 	}
535 out_free:
536 	kfree(new_eba_tbl);
537 	return err;
538 }
539 
540 /**
541  * ubi_rename_volumes - re-name UBI volumes.
542  * @ubi: UBI device description object
543  * @rename_list: list of &struct ubi_rename_entry objects
544  *
545  * This function re-names or removes volumes specified in the re-name list.
546  * Returns zero in case of success and a negative error code in case of
547  * failure.
548  */
549 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list)
550 {
551 	int err;
552 	struct ubi_rename_entry *re;
553 
554 	err = ubi_vtbl_rename_volumes(ubi, rename_list);
555 	if (err)
556 		return err;
557 
558 	list_for_each_entry(re, rename_list, list) {
559 		if (re->remove) {
560 			err = ubi_remove_volume(re->desc, 1);
561 			if (err)
562 				break;
563 		} else {
564 			struct ubi_volume *vol = re->desc->vol;
565 
566 			spin_lock(&ubi->volumes_lock);
567 			vol->name_len = re->new_name_len;
568 			memcpy(vol->name, re->new_name, re->new_name_len + 1);
569 			spin_unlock(&ubi->volumes_lock);
570 			ubi_volume_notify(ubi, vol, UBI_VOLUME_RENAMED);
571 		}
572 	}
573 
574 	if (!err)
575 		self_check_volumes(ubi);
576 	return err;
577 }
578 
579 /**
580  * ubi_add_volume - add volume.
581  * @ubi: UBI device description object
582  * @vol: volume description object
583  *
584  * This function adds an existing volume and initializes all its data
585  * structures. Returns zero in case of success and a negative error code in
586  * case of failure.
587  */
588 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol)
589 {
590 	int err, vol_id = vol->vol_id;
591 	dev_t dev;
592 
593 	dbg_gen("add volume %d", vol_id);
594 
595 	/* Register character device for the volume */
596 	cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
597 	vol->cdev.owner = THIS_MODULE;
598 	dev = MKDEV(MAJOR(ubi->cdev.dev), vol->vol_id + 1);
599 	err = cdev_add(&vol->cdev, dev, 1);
600 	if (err) {
601 		ubi_err(ubi, "cannot add character device for volume %d, error %d",
602 			vol_id, err);
603 		return err;
604 	}
605 
606 	vol->dev.release = vol_release;
607 	vol->dev.parent = &ubi->dev;
608 	vol->dev.devt = dev;
609 	vol->dev.class = &ubi_class;
610 	vol->dev.groups = volume_dev_groups;
611 	dev_set_name(&vol->dev, "%s_%d", ubi->ubi_name, vol->vol_id);
612 	err = device_register(&vol->dev);
613 	if (err)
614 		goto out_cdev;
615 
616 	self_check_volumes(ubi);
617 	return err;
618 
619 out_cdev:
620 	cdev_del(&vol->cdev);
621 	return err;
622 }
623 
624 /**
625  * ubi_free_volume - free volume.
626  * @ubi: UBI device description object
627  * @vol: volume description object
628  *
629  * This function frees all resources for volume @vol but does not remove it.
630  * Used only when the UBI device is detached.
631  */
632 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol)
633 {
634 	dbg_gen("free volume %d", vol->vol_id);
635 
636 	ubi->volumes[vol->vol_id] = NULL;
637 	cdev_del(&vol->cdev);
638 	device_unregister(&vol->dev);
639 }
640 
641 /**
642  * self_check_volume - check volume information.
643  * @ubi: UBI device description object
644  * @vol_id: volume ID
645  *
646  * Returns zero if volume is all right and a a negative error code if not.
647  */
648 static int self_check_volume(struct ubi_device *ubi, int vol_id)
649 {
650 	int idx = vol_id2idx(ubi, vol_id);
651 	int reserved_pebs, alignment, data_pad, vol_type, name_len, upd_marker;
652 	const struct ubi_volume *vol;
653 	long long n;
654 	const char *name;
655 
656 	spin_lock(&ubi->volumes_lock);
657 	reserved_pebs = be32_to_cpu(ubi->vtbl[vol_id].reserved_pebs);
658 	vol = ubi->volumes[idx];
659 
660 	if (!vol) {
661 		if (reserved_pebs) {
662 			ubi_err(ubi, "no volume info, but volume exists");
663 			goto fail;
664 		}
665 		spin_unlock(&ubi->volumes_lock);
666 		return 0;
667 	}
668 
669 	if (vol->reserved_pebs < 0 || vol->alignment < 0 || vol->data_pad < 0 ||
670 	    vol->name_len < 0) {
671 		ubi_err(ubi, "negative values");
672 		goto fail;
673 	}
674 	if (vol->alignment > ubi->leb_size || vol->alignment == 0) {
675 		ubi_err(ubi, "bad alignment");
676 		goto fail;
677 	}
678 
679 	n = vol->alignment & (ubi->min_io_size - 1);
680 	if (vol->alignment != 1 && n) {
681 		ubi_err(ubi, "alignment is not multiple of min I/O unit");
682 		goto fail;
683 	}
684 
685 	n = ubi->leb_size % vol->alignment;
686 	if (vol->data_pad != n) {
687 		ubi_err(ubi, "bad data_pad, has to be %lld", n);
688 		goto fail;
689 	}
690 
691 	if (vol->vol_type != UBI_DYNAMIC_VOLUME &&
692 	    vol->vol_type != UBI_STATIC_VOLUME) {
693 		ubi_err(ubi, "bad vol_type");
694 		goto fail;
695 	}
696 
697 	if (vol->upd_marker && vol->corrupted) {
698 		ubi_err(ubi, "update marker and corrupted simultaneously");
699 		goto fail;
700 	}
701 
702 	if (vol->reserved_pebs > ubi->good_peb_count) {
703 		ubi_err(ubi, "too large reserved_pebs");
704 		goto fail;
705 	}
706 
707 	n = ubi->leb_size - vol->data_pad;
708 	if (vol->usable_leb_size != ubi->leb_size - vol->data_pad) {
709 		ubi_err(ubi, "bad usable_leb_size, has to be %lld", n);
710 		goto fail;
711 	}
712 
713 	if (vol->name_len > UBI_VOL_NAME_MAX) {
714 		ubi_err(ubi, "too long volume name, max is %d",
715 			UBI_VOL_NAME_MAX);
716 		goto fail;
717 	}
718 
719 	n = strnlen(vol->name, vol->name_len + 1);
720 	if (n != vol->name_len) {
721 		ubi_err(ubi, "bad name_len %lld", n);
722 		goto fail;
723 	}
724 
725 	n = (long long)vol->used_ebs * vol->usable_leb_size;
726 	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
727 		if (vol->corrupted) {
728 			ubi_err(ubi, "corrupted dynamic volume");
729 			goto fail;
730 		}
731 		if (vol->used_ebs != vol->reserved_pebs) {
732 			ubi_err(ubi, "bad used_ebs");
733 			goto fail;
734 		}
735 		if (vol->last_eb_bytes != vol->usable_leb_size) {
736 			ubi_err(ubi, "bad last_eb_bytes");
737 			goto fail;
738 		}
739 		if (vol->used_bytes != n) {
740 			ubi_err(ubi, "bad used_bytes");
741 			goto fail;
742 		}
743 
744 		if (vol->skip_check) {
745 			ubi_err(ubi, "bad skip_check");
746 			goto fail;
747 		}
748 	} else {
749 		if (vol->used_ebs < 0 || vol->used_ebs > vol->reserved_pebs) {
750 			ubi_err(ubi, "bad used_ebs");
751 			goto fail;
752 		}
753 		if (vol->last_eb_bytes < 0 ||
754 		    vol->last_eb_bytes > vol->usable_leb_size) {
755 			ubi_err(ubi, "bad last_eb_bytes");
756 			goto fail;
757 		}
758 		if (vol->used_bytes < 0 || vol->used_bytes > n ||
759 		    vol->used_bytes < n - vol->usable_leb_size) {
760 			ubi_err(ubi, "bad used_bytes");
761 			goto fail;
762 		}
763 	}
764 
765 	alignment  = be32_to_cpu(ubi->vtbl[vol_id].alignment);
766 	data_pad   = be32_to_cpu(ubi->vtbl[vol_id].data_pad);
767 	name_len   = be16_to_cpu(ubi->vtbl[vol_id].name_len);
768 	upd_marker = ubi->vtbl[vol_id].upd_marker;
769 	name       = &ubi->vtbl[vol_id].name[0];
770 	if (ubi->vtbl[vol_id].vol_type == UBI_VID_DYNAMIC)
771 		vol_type = UBI_DYNAMIC_VOLUME;
772 	else
773 		vol_type = UBI_STATIC_VOLUME;
774 
775 	if (alignment != vol->alignment || data_pad != vol->data_pad ||
776 	    upd_marker != vol->upd_marker || vol_type != vol->vol_type ||
777 	    name_len != vol->name_len || strncmp(name, vol->name, name_len)) {
778 		ubi_err(ubi, "volume info is different");
779 		goto fail;
780 	}
781 
782 	spin_unlock(&ubi->volumes_lock);
783 	return 0;
784 
785 fail:
786 	ubi_err(ubi, "self-check failed for volume %d", vol_id);
787 	if (vol)
788 		ubi_dump_vol_info(vol);
789 	ubi_dump_vtbl_record(&ubi->vtbl[vol_id], vol_id);
790 	dump_stack();
791 	spin_unlock(&ubi->volumes_lock);
792 	return -EINVAL;
793 }
794 
795 /**
796  * self_check_volumes - check information about all volumes.
797  * @ubi: UBI device description object
798  *
799  * Returns zero if volumes are all right and a a negative error code if not.
800  */
801 static int self_check_volumes(struct ubi_device *ubi)
802 {
803 	int i, err = 0;
804 
805 	if (!ubi_dbg_chk_gen(ubi))
806 		return 0;
807 
808 	for (i = 0; i < ubi->vtbl_slots; i++) {
809 		err = self_check_volume(ubi, i);
810 		if (err)
811 			break;
812 	}
813 
814 	return err;
815 }
816