xref: /openbmc/linux/drivers/mtd/ubi/vmt.c (revision 4800cd83)
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 "ubi.h"
30 
31 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
32 static int paranoid_check_volumes(struct ubi_device *ubi);
33 #else
34 #define paranoid_check_volumes(ubi) 0
35 #endif
36 
37 static ssize_t vol_attribute_show(struct device *dev,
38 				  struct device_attribute *attr, char *buf);
39 
40 /* Device attributes corresponding to files in '/<sysfs>/class/ubi/ubiX_Y' */
41 static struct device_attribute attr_vol_reserved_ebs =
42 	__ATTR(reserved_ebs, S_IRUGO, vol_attribute_show, NULL);
43 static struct device_attribute attr_vol_type =
44 	__ATTR(type, S_IRUGO, vol_attribute_show, NULL);
45 static struct device_attribute attr_vol_name =
46 	__ATTR(name, S_IRUGO, vol_attribute_show, NULL);
47 static struct device_attribute attr_vol_corrupted =
48 	__ATTR(corrupted, S_IRUGO, vol_attribute_show, NULL);
49 static struct device_attribute attr_vol_alignment =
50 	__ATTR(alignment, S_IRUGO, vol_attribute_show, NULL);
51 static struct device_attribute attr_vol_usable_eb_size =
52 	__ATTR(usable_eb_size, S_IRUGO, vol_attribute_show, NULL);
53 static struct device_attribute attr_vol_data_bytes =
54 	__ATTR(data_bytes, S_IRUGO, vol_attribute_show, NULL);
55 static struct device_attribute attr_vol_upd_marker =
56 	__ATTR(upd_marker, S_IRUGO, vol_attribute_show, NULL);
57 
58 /*
59  * "Show" method for files in '/<sysfs>/class/ubi/ubiX_Y/'.
60  *
61  * Consider a situation:
62  * A. process 1 opens a sysfs file related to volume Y, say
63  *    /<sysfs>/class/ubi/ubiX_Y/reserved_ebs;
64  * B. process 2 removes volume Y;
65  * C. process 1 starts reading the /<sysfs>/class/ubi/ubiX_Y/reserved_ebs file;
66  *
67  * In this situation, this function will return %-ENODEV because it will find
68  * out that the volume was removed from the @ubi->volumes array.
69  */
70 static ssize_t vol_attribute_show(struct device *dev,
71 				  struct device_attribute *attr, char *buf)
72 {
73 	int ret;
74 	struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev);
75 	struct ubi_device *ubi;
76 
77 	ubi = ubi_get_device(vol->ubi->ubi_num);
78 	if (!ubi)
79 		return -ENODEV;
80 
81 	spin_lock(&ubi->volumes_lock);
82 	if (!ubi->volumes[vol->vol_id]) {
83 		spin_unlock(&ubi->volumes_lock);
84 		ubi_put_device(ubi);
85 		return -ENODEV;
86 	}
87 	/* Take a reference to prevent volume removal */
88 	vol->ref_count += 1;
89 	spin_unlock(&ubi->volumes_lock);
90 
91 	if (attr == &attr_vol_reserved_ebs)
92 		ret = sprintf(buf, "%d\n", vol->reserved_pebs);
93 	else if (attr == &attr_vol_type) {
94 		const char *tp;
95 
96 		if (vol->vol_type == UBI_DYNAMIC_VOLUME)
97 			tp = "dynamic";
98 		else
99 			tp = "static";
100 		ret = sprintf(buf, "%s\n", tp);
101 	} else if (attr == &attr_vol_name)
102 		ret = sprintf(buf, "%s\n", vol->name);
103 	else if (attr == &attr_vol_corrupted)
104 		ret = sprintf(buf, "%d\n", vol->corrupted);
105 	else if (attr == &attr_vol_alignment)
106 		ret = sprintf(buf, "%d\n", vol->alignment);
107 	else if (attr == &attr_vol_usable_eb_size)
108 		ret = sprintf(buf, "%d\n", vol->usable_leb_size);
109 	else if (attr == &attr_vol_data_bytes)
110 		ret = sprintf(buf, "%lld\n", vol->used_bytes);
111 	else if (attr == &attr_vol_upd_marker)
112 		ret = sprintf(buf, "%d\n", vol->upd_marker);
113 	else
114 		/* This must be a bug */
115 		ret = -EINVAL;
116 
117 	/* We've done the operation, drop volume and UBI device references */
118 	spin_lock(&ubi->volumes_lock);
119 	vol->ref_count -= 1;
120 	ubi_assert(vol->ref_count >= 0);
121 	spin_unlock(&ubi->volumes_lock);
122 	ubi_put_device(ubi);
123 	return ret;
124 }
125 
126 /* Release method for volume devices */
127 static void vol_release(struct device *dev)
128 {
129 	struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev);
130 
131 	kfree(vol->eba_tbl);
132 	kfree(vol);
133 }
134 
135 /**
136  * volume_sysfs_init - initialize sysfs for new volume.
137  * @ubi: UBI device description object
138  * @vol: volume description object
139  *
140  * This function returns zero in case of success and a negative error code in
141  * case of failure.
142  *
143  * Note, this function does not free allocated resources in case of failure -
144  * the caller does it. This is because this would cause release() here and the
145  * caller would oops.
146  */
147 static int volume_sysfs_init(struct ubi_device *ubi, struct ubi_volume *vol)
148 {
149 	int err;
150 
151 	err = device_create_file(&vol->dev, &attr_vol_reserved_ebs);
152 	if (err)
153 		return err;
154 	err = device_create_file(&vol->dev, &attr_vol_type);
155 	if (err)
156 		return err;
157 	err = device_create_file(&vol->dev, &attr_vol_name);
158 	if (err)
159 		return err;
160 	err = device_create_file(&vol->dev, &attr_vol_corrupted);
161 	if (err)
162 		return err;
163 	err = device_create_file(&vol->dev, &attr_vol_alignment);
164 	if (err)
165 		return err;
166 	err = device_create_file(&vol->dev, &attr_vol_usable_eb_size);
167 	if (err)
168 		return err;
169 	err = device_create_file(&vol->dev, &attr_vol_data_bytes);
170 	if (err)
171 		return err;
172 	err = device_create_file(&vol->dev, &attr_vol_upd_marker);
173 	return err;
174 }
175 
176 /**
177  * volume_sysfs_close - close sysfs for a volume.
178  * @vol: volume description object
179  */
180 static void volume_sysfs_close(struct ubi_volume *vol)
181 {
182 	device_remove_file(&vol->dev, &attr_vol_upd_marker);
183 	device_remove_file(&vol->dev, &attr_vol_data_bytes);
184 	device_remove_file(&vol->dev, &attr_vol_usable_eb_size);
185 	device_remove_file(&vol->dev, &attr_vol_alignment);
186 	device_remove_file(&vol->dev, &attr_vol_corrupted);
187 	device_remove_file(&vol->dev, &attr_vol_name);
188 	device_remove_file(&vol->dev, &attr_vol_type);
189 	device_remove_file(&vol->dev, &attr_vol_reserved_ebs);
190 	device_unregister(&vol->dev);
191 }
192 
193 /**
194  * ubi_create_volume - create volume.
195  * @ubi: UBI device description object
196  * @req: volume creation request
197  *
198  * This function creates volume described by @req. If @req->vol_id id
199  * %UBI_VOL_NUM_AUTO, this function automatically assign ID to the new volume
200  * and saves it in @req->vol_id. Returns zero in case of success and a negative
201  * error code in case of failure. Note, the caller has to have the
202  * @ubi->device_mutex locked.
203  */
204 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
205 {
206 	int i, err, vol_id = req->vol_id, do_free = 1;
207 	struct ubi_volume *vol;
208 	struct ubi_vtbl_record vtbl_rec;
209 	dev_t dev;
210 
211 	if (ubi->ro_mode)
212 		return -EROFS;
213 
214 	vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL);
215 	if (!vol)
216 		return -ENOMEM;
217 
218 	spin_lock(&ubi->volumes_lock);
219 	if (vol_id == UBI_VOL_NUM_AUTO) {
220 		/* Find unused volume ID */
221 		dbg_gen("search for vacant volume ID");
222 		for (i = 0; i < ubi->vtbl_slots; i++)
223 			if (!ubi->volumes[i]) {
224 				vol_id = i;
225 				break;
226 			}
227 
228 		if (vol_id == UBI_VOL_NUM_AUTO) {
229 			dbg_err("out of volume IDs");
230 			err = -ENFILE;
231 			goto out_unlock;
232 		}
233 		req->vol_id = vol_id;
234 	}
235 
236 	dbg_gen("create device %d, volume %d, %llu bytes, type %d, name %s",
237 		ubi->ubi_num, vol_id, (unsigned long long)req->bytes,
238 		(int)req->vol_type, req->name);
239 
240 	/* Ensure that this volume does not exist */
241 	err = -EEXIST;
242 	if (ubi->volumes[vol_id]) {
243 		dbg_err("volume %d already exists", vol_id);
244 		goto out_unlock;
245 	}
246 
247 	/* Ensure that the name is unique */
248 	for (i = 0; i < ubi->vtbl_slots; i++)
249 		if (ubi->volumes[i] &&
250 		    ubi->volumes[i]->name_len == req->name_len &&
251 		    !strcmp(ubi->volumes[i]->name, req->name)) {
252 			dbg_err("volume \"%s\" exists (ID %d)", req->name, i);
253 			goto out_unlock;
254 		}
255 
256 	/* Calculate how many eraseblocks are requested */
257 	vol->usable_leb_size = ubi->leb_size - ubi->leb_size % req->alignment;
258 	vol->reserved_pebs += div_u64(req->bytes + vol->usable_leb_size - 1,
259 				      vol->usable_leb_size);
260 
261 	/* Reserve physical eraseblocks */
262 	if (vol->reserved_pebs > ubi->avail_pebs) {
263 		dbg_err("not enough PEBs, only %d available", ubi->avail_pebs);
264 		if (ubi->corr_peb_count)
265 			dbg_err("%d PEBs are corrupted and not used",
266 				ubi->corr_peb_count);
267 		err = -ENOSPC;
268 		goto out_unlock;
269 	}
270 	ubi->avail_pebs -= vol->reserved_pebs;
271 	ubi->rsvd_pebs += vol->reserved_pebs;
272 	spin_unlock(&ubi->volumes_lock);
273 
274 	vol->vol_id    = vol_id;
275 	vol->alignment = req->alignment;
276 	vol->data_pad  = ubi->leb_size % vol->alignment;
277 	vol->vol_type  = req->vol_type;
278 	vol->name_len  = req->name_len;
279 	memcpy(vol->name, req->name, vol->name_len);
280 	vol->ubi = ubi;
281 
282 	/*
283 	 * Finish all pending erases because there may be some LEBs belonging
284 	 * to the same volume ID.
285 	 */
286 	err = ubi_wl_flush(ubi);
287 	if (err)
288 		goto out_acc;
289 
290 	vol->eba_tbl = kmalloc(vol->reserved_pebs * sizeof(int), GFP_KERNEL);
291 	if (!vol->eba_tbl) {
292 		err = -ENOMEM;
293 		goto out_acc;
294 	}
295 
296 	for (i = 0; i < vol->reserved_pebs; i++)
297 		vol->eba_tbl[i] = UBI_LEB_UNMAPPED;
298 
299 	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
300 		vol->used_ebs = vol->reserved_pebs;
301 		vol->last_eb_bytes = vol->usable_leb_size;
302 		vol->used_bytes =
303 			(long long)vol->used_ebs * vol->usable_leb_size;
304 	} else {
305 		vol->used_ebs = div_u64_rem(vol->used_bytes,
306 					    vol->usable_leb_size,
307 					    &vol->last_eb_bytes);
308 		if (vol->last_eb_bytes != 0)
309 			vol->used_ebs += 1;
310 		else
311 			vol->last_eb_bytes = vol->usable_leb_size;
312 	}
313 
314 	/* Register character device for the volume */
315 	cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
316 	vol->cdev.owner = THIS_MODULE;
317 	dev = MKDEV(MAJOR(ubi->cdev.dev), vol_id + 1);
318 	err = cdev_add(&vol->cdev, dev, 1);
319 	if (err) {
320 		ubi_err("cannot add character device");
321 		goto out_mapping;
322 	}
323 
324 	vol->dev.release = vol_release;
325 	vol->dev.parent = &ubi->dev;
326 	vol->dev.devt = dev;
327 	vol->dev.class = ubi_class;
328 
329 	dev_set_name(&vol->dev, "%s_%d", ubi->ubi_name, vol->vol_id);
330 	err = device_register(&vol->dev);
331 	if (err) {
332 		ubi_err("cannot register device");
333 		goto out_cdev;
334 	}
335 
336 	err = volume_sysfs_init(ubi, vol);
337 	if (err)
338 		goto out_sysfs;
339 
340 	/* Fill volume table record */
341 	memset(&vtbl_rec, 0, sizeof(struct ubi_vtbl_record));
342 	vtbl_rec.reserved_pebs = cpu_to_be32(vol->reserved_pebs);
343 	vtbl_rec.alignment     = cpu_to_be32(vol->alignment);
344 	vtbl_rec.data_pad      = cpu_to_be32(vol->data_pad);
345 	vtbl_rec.name_len      = cpu_to_be16(vol->name_len);
346 	if (vol->vol_type == UBI_DYNAMIC_VOLUME)
347 		vtbl_rec.vol_type = UBI_VID_DYNAMIC;
348 	else
349 		vtbl_rec.vol_type = UBI_VID_STATIC;
350 	memcpy(vtbl_rec.name, vol->name, vol->name_len);
351 
352 	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
353 	if (err)
354 		goto out_sysfs;
355 
356 	spin_lock(&ubi->volumes_lock);
357 	ubi->volumes[vol_id] = vol;
358 	ubi->vol_count += 1;
359 	spin_unlock(&ubi->volumes_lock);
360 
361 	ubi_volume_notify(ubi, vol, UBI_VOLUME_ADDED);
362 	if (paranoid_check_volumes(ubi))
363 		dbg_err("check failed while creating volume %d", vol_id);
364 	return err;
365 
366 out_sysfs:
367 	/*
368 	 * We have registered our device, we should not free the volume
369 	 * description object in this function in case of an error - it is
370 	 * freed by the release function.
371 	 *
372 	 * Get device reference to prevent the release function from being
373 	 * called just after sysfs has been closed.
374 	 */
375 	do_free = 0;
376 	get_device(&vol->dev);
377 	volume_sysfs_close(vol);
378 out_cdev:
379 	cdev_del(&vol->cdev);
380 out_mapping:
381 	if (do_free)
382 		kfree(vol->eba_tbl);
383 out_acc:
384 	spin_lock(&ubi->volumes_lock);
385 	ubi->rsvd_pebs -= vol->reserved_pebs;
386 	ubi->avail_pebs += vol->reserved_pebs;
387 out_unlock:
388 	spin_unlock(&ubi->volumes_lock);
389 	if (do_free)
390 		kfree(vol);
391 	else
392 		put_device(&vol->dev);
393 	ubi_err("cannot create volume %d, error %d", vol_id, err);
394 	return err;
395 }
396 
397 /**
398  * ubi_remove_volume - remove volume.
399  * @desc: volume descriptor
400  * @no_vtbl: do not change volume table if not zero
401  *
402  * This function removes volume described by @desc. The volume has to be opened
403  * in "exclusive" mode. Returns zero in case of success and a negative error
404  * code in case of failure. The caller has to have the @ubi->device_mutex
405  * locked.
406  */
407 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl)
408 {
409 	struct ubi_volume *vol = desc->vol;
410 	struct ubi_device *ubi = vol->ubi;
411 	int i, err, vol_id = vol->vol_id, reserved_pebs = vol->reserved_pebs;
412 
413 	dbg_gen("remove device %d, volume %d", ubi->ubi_num, vol_id);
414 	ubi_assert(desc->mode == UBI_EXCLUSIVE);
415 	ubi_assert(vol == ubi->volumes[vol_id]);
416 
417 	if (ubi->ro_mode)
418 		return -EROFS;
419 
420 	spin_lock(&ubi->volumes_lock);
421 	if (vol->ref_count > 1) {
422 		/*
423 		 * The volume is busy, probably someone is reading one of its
424 		 * sysfs files.
425 		 */
426 		err = -EBUSY;
427 		goto out_unlock;
428 	}
429 	ubi->volumes[vol_id] = NULL;
430 	spin_unlock(&ubi->volumes_lock);
431 
432 	if (!no_vtbl) {
433 		err = ubi_change_vtbl_record(ubi, vol_id, NULL);
434 		if (err)
435 			goto out_err;
436 	}
437 
438 	for (i = 0; i < vol->reserved_pebs; i++) {
439 		err = ubi_eba_unmap_leb(ubi, vol, i);
440 		if (err)
441 			goto out_err;
442 	}
443 
444 	cdev_del(&vol->cdev);
445 	volume_sysfs_close(vol);
446 
447 	spin_lock(&ubi->volumes_lock);
448 	ubi->rsvd_pebs -= reserved_pebs;
449 	ubi->avail_pebs += reserved_pebs;
450 	i = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs;
451 	if (i > 0) {
452 		i = ubi->avail_pebs >= i ? i : ubi->avail_pebs;
453 		ubi->avail_pebs -= i;
454 		ubi->rsvd_pebs += i;
455 		ubi->beb_rsvd_pebs += i;
456 		if (i > 0)
457 			ubi_msg("reserve more %d PEBs", i);
458 	}
459 	ubi->vol_count -= 1;
460 	spin_unlock(&ubi->volumes_lock);
461 
462 	ubi_volume_notify(ubi, vol, UBI_VOLUME_REMOVED);
463 	if (!no_vtbl && paranoid_check_volumes(ubi))
464 		dbg_err("check failed while removing volume %d", vol_id);
465 
466 	return err;
467 
468 out_err:
469 	ubi_err("cannot remove volume %d, error %d", vol_id, err);
470 	spin_lock(&ubi->volumes_lock);
471 	ubi->volumes[vol_id] = vol;
472 out_unlock:
473 	spin_unlock(&ubi->volumes_lock);
474 	return err;
475 }
476 
477 /**
478  * ubi_resize_volume - re-size volume.
479  * @desc: volume descriptor
480  * @reserved_pebs: new size in physical eraseblocks
481  *
482  * This function re-sizes the volume and returns zero in case of success, and a
483  * negative error code in case of failure. The caller has to have the
484  * @ubi->device_mutex locked.
485  */
486 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs)
487 {
488 	int i, err, pebs, *new_mapping;
489 	struct ubi_volume *vol = desc->vol;
490 	struct ubi_device *ubi = vol->ubi;
491 	struct ubi_vtbl_record vtbl_rec;
492 	int vol_id = vol->vol_id;
493 
494 	if (ubi->ro_mode)
495 		return -EROFS;
496 
497 	dbg_gen("re-size device %d, volume %d to from %d to %d PEBs",
498 		ubi->ubi_num, vol_id, vol->reserved_pebs, reserved_pebs);
499 
500 	if (vol->vol_type == UBI_STATIC_VOLUME &&
501 	    reserved_pebs < vol->used_ebs) {
502 		dbg_err("too small size %d, %d LEBs contain data",
503 			reserved_pebs, vol->used_ebs);
504 		return -EINVAL;
505 	}
506 
507 	/* If the size is the same, we have nothing to do */
508 	if (reserved_pebs == vol->reserved_pebs)
509 		return 0;
510 
511 	new_mapping = kmalloc(reserved_pebs * sizeof(int), GFP_KERNEL);
512 	if (!new_mapping)
513 		return -ENOMEM;
514 
515 	for (i = 0; i < reserved_pebs; i++)
516 		new_mapping[i] = UBI_LEB_UNMAPPED;
517 
518 	spin_lock(&ubi->volumes_lock);
519 	if (vol->ref_count > 1) {
520 		spin_unlock(&ubi->volumes_lock);
521 		err = -EBUSY;
522 		goto out_free;
523 	}
524 	spin_unlock(&ubi->volumes_lock);
525 
526 	/* Reserve physical eraseblocks */
527 	pebs = reserved_pebs - vol->reserved_pebs;
528 	if (pebs > 0) {
529 		spin_lock(&ubi->volumes_lock);
530 		if (pebs > ubi->avail_pebs) {
531 			dbg_err("not enough PEBs: requested %d, available %d",
532 				pebs, ubi->avail_pebs);
533 			if (ubi->corr_peb_count)
534 				dbg_err("%d PEBs are corrupted and not used",
535 					ubi->corr_peb_count);
536 			spin_unlock(&ubi->volumes_lock);
537 			err = -ENOSPC;
538 			goto out_free;
539 		}
540 		ubi->avail_pebs -= pebs;
541 		ubi->rsvd_pebs += pebs;
542 		for (i = 0; i < vol->reserved_pebs; i++)
543 			new_mapping[i] = vol->eba_tbl[i];
544 		kfree(vol->eba_tbl);
545 		vol->eba_tbl = new_mapping;
546 		spin_unlock(&ubi->volumes_lock);
547 	}
548 
549 	/* Change volume table record */
550 	memcpy(&vtbl_rec, &ubi->vtbl[vol_id], sizeof(struct ubi_vtbl_record));
551 	vtbl_rec.reserved_pebs = cpu_to_be32(reserved_pebs);
552 	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
553 	if (err)
554 		goto out_acc;
555 
556 	if (pebs < 0) {
557 		for (i = 0; i < -pebs; i++) {
558 			err = ubi_eba_unmap_leb(ubi, vol, reserved_pebs + i);
559 			if (err)
560 				goto out_acc;
561 		}
562 		spin_lock(&ubi->volumes_lock);
563 		ubi->rsvd_pebs += pebs;
564 		ubi->avail_pebs -= pebs;
565 		pebs = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs;
566 		if (pebs > 0) {
567 			pebs = ubi->avail_pebs >= pebs ? pebs : ubi->avail_pebs;
568 			ubi->avail_pebs -= pebs;
569 			ubi->rsvd_pebs += pebs;
570 			ubi->beb_rsvd_pebs += pebs;
571 			if (pebs > 0)
572 				ubi_msg("reserve more %d PEBs", pebs);
573 		}
574 		for (i = 0; i < reserved_pebs; i++)
575 			new_mapping[i] = vol->eba_tbl[i];
576 		kfree(vol->eba_tbl);
577 		vol->eba_tbl = new_mapping;
578 		spin_unlock(&ubi->volumes_lock);
579 	}
580 
581 	vol->reserved_pebs = reserved_pebs;
582 	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
583 		vol->used_ebs = reserved_pebs;
584 		vol->last_eb_bytes = vol->usable_leb_size;
585 		vol->used_bytes =
586 			(long long)vol->used_ebs * vol->usable_leb_size;
587 	}
588 
589 	ubi_volume_notify(ubi, vol, UBI_VOLUME_RESIZED);
590 	if (paranoid_check_volumes(ubi))
591 		dbg_err("check failed while re-sizing volume %d", vol_id);
592 	return err;
593 
594 out_acc:
595 	if (pebs > 0) {
596 		spin_lock(&ubi->volumes_lock);
597 		ubi->rsvd_pebs -= pebs;
598 		ubi->avail_pebs += pebs;
599 		spin_unlock(&ubi->volumes_lock);
600 	}
601 out_free:
602 	kfree(new_mapping);
603 	return err;
604 }
605 
606 /**
607  * ubi_rename_volumes - re-name UBI volumes.
608  * @ubi: UBI device description object
609  * @rename_list: list of &struct ubi_rename_entry objects
610  *
611  * This function re-names or removes volumes specified in the re-name list.
612  * Returns zero in case of success and a negative error code in case of
613  * failure.
614  */
615 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list)
616 {
617 	int err;
618 	struct ubi_rename_entry *re;
619 
620 	err = ubi_vtbl_rename_volumes(ubi, rename_list);
621 	if (err)
622 		return err;
623 
624 	list_for_each_entry(re, rename_list, list) {
625 		if (re->remove) {
626 			err = ubi_remove_volume(re->desc, 1);
627 			if (err)
628 				break;
629 		} else {
630 			struct ubi_volume *vol = re->desc->vol;
631 
632 			spin_lock(&ubi->volumes_lock);
633 			vol->name_len = re->new_name_len;
634 			memcpy(vol->name, re->new_name, re->new_name_len + 1);
635 			spin_unlock(&ubi->volumes_lock);
636 			ubi_volume_notify(ubi, vol, UBI_VOLUME_RENAMED);
637 		}
638 	}
639 
640 	if (!err && paranoid_check_volumes(ubi))
641 		;
642 	return err;
643 }
644 
645 /**
646  * ubi_add_volume - add volume.
647  * @ubi: UBI device description object
648  * @vol: volume description object
649  *
650  * This function adds an existing volume and initializes all its data
651  * structures. Returns zero in case of success and a negative error code in
652  * case of failure.
653  */
654 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol)
655 {
656 	int err, vol_id = vol->vol_id;
657 	dev_t dev;
658 
659 	dbg_gen("add volume %d", vol_id);
660 
661 	/* Register character device for the volume */
662 	cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
663 	vol->cdev.owner = THIS_MODULE;
664 	dev = MKDEV(MAJOR(ubi->cdev.dev), vol->vol_id + 1);
665 	err = cdev_add(&vol->cdev, dev, 1);
666 	if (err) {
667 		ubi_err("cannot add character device for volume %d, error %d",
668 			vol_id, err);
669 		return err;
670 	}
671 
672 	vol->dev.release = vol_release;
673 	vol->dev.parent = &ubi->dev;
674 	vol->dev.devt = dev;
675 	vol->dev.class = ubi_class;
676 	dev_set_name(&vol->dev, "%s_%d", ubi->ubi_name, vol->vol_id);
677 	err = device_register(&vol->dev);
678 	if (err)
679 		goto out_cdev;
680 
681 	err = volume_sysfs_init(ubi, vol);
682 	if (err) {
683 		cdev_del(&vol->cdev);
684 		volume_sysfs_close(vol);
685 		return err;
686 	}
687 
688 	if (paranoid_check_volumes(ubi))
689 		dbg_err("check failed while adding volume %d", vol_id);
690 	return err;
691 
692 out_cdev:
693 	cdev_del(&vol->cdev);
694 	return err;
695 }
696 
697 /**
698  * ubi_free_volume - free volume.
699  * @ubi: UBI device description object
700  * @vol: volume description object
701  *
702  * This function frees all resources for volume @vol but does not remove it.
703  * Used only when the UBI device is detached.
704  */
705 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol)
706 {
707 	dbg_gen("free volume %d", vol->vol_id);
708 
709 	ubi->volumes[vol->vol_id] = NULL;
710 	cdev_del(&vol->cdev);
711 	volume_sysfs_close(vol);
712 }
713 
714 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
715 
716 /**
717  * paranoid_check_volume - check volume information.
718  * @ubi: UBI device description object
719  * @vol_id: volume ID
720  *
721  * Returns zero if volume is all right and a a negative error code if not.
722  */
723 static int paranoid_check_volume(struct ubi_device *ubi, int vol_id)
724 {
725 	int idx = vol_id2idx(ubi, vol_id);
726 	int reserved_pebs, alignment, data_pad, vol_type, name_len, upd_marker;
727 	const struct ubi_volume *vol;
728 	long long n;
729 	const char *name;
730 
731 	spin_lock(&ubi->volumes_lock);
732 	reserved_pebs = be32_to_cpu(ubi->vtbl[vol_id].reserved_pebs);
733 	vol = ubi->volumes[idx];
734 
735 	if (!vol) {
736 		if (reserved_pebs) {
737 			ubi_err("no volume info, but volume exists");
738 			goto fail;
739 		}
740 		spin_unlock(&ubi->volumes_lock);
741 		return 0;
742 	}
743 
744 	if (vol->reserved_pebs < 0 || vol->alignment < 0 || vol->data_pad < 0 ||
745 	    vol->name_len < 0) {
746 		ubi_err("negative values");
747 		goto fail;
748 	}
749 	if (vol->alignment > ubi->leb_size || vol->alignment == 0) {
750 		ubi_err("bad alignment");
751 		goto fail;
752 	}
753 
754 	n = vol->alignment & (ubi->min_io_size - 1);
755 	if (vol->alignment != 1 && n) {
756 		ubi_err("alignment is not multiple of min I/O unit");
757 		goto fail;
758 	}
759 
760 	n = ubi->leb_size % vol->alignment;
761 	if (vol->data_pad != n) {
762 		ubi_err("bad data_pad, has to be %lld", n);
763 		goto fail;
764 	}
765 
766 	if (vol->vol_type != UBI_DYNAMIC_VOLUME &&
767 	    vol->vol_type != UBI_STATIC_VOLUME) {
768 		ubi_err("bad vol_type");
769 		goto fail;
770 	}
771 
772 	if (vol->upd_marker && vol->corrupted) {
773 		dbg_err("update marker and corrupted simultaneously");
774 		goto fail;
775 	}
776 
777 	if (vol->reserved_pebs > ubi->good_peb_count) {
778 		ubi_err("too large reserved_pebs");
779 		goto fail;
780 	}
781 
782 	n = ubi->leb_size - vol->data_pad;
783 	if (vol->usable_leb_size != ubi->leb_size - vol->data_pad) {
784 		ubi_err("bad usable_leb_size, has to be %lld", n);
785 		goto fail;
786 	}
787 
788 	if (vol->name_len > UBI_VOL_NAME_MAX) {
789 		ubi_err("too long volume name, max is %d", UBI_VOL_NAME_MAX);
790 		goto fail;
791 	}
792 
793 	if (!vol->name) {
794 		ubi_err("NULL volume name");
795 		goto fail;
796 	}
797 
798 	n = strnlen(vol->name, vol->name_len + 1);
799 	if (n != vol->name_len) {
800 		ubi_err("bad name_len %lld", n);
801 		goto fail;
802 	}
803 
804 	n = (long long)vol->used_ebs * vol->usable_leb_size;
805 	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
806 		if (vol->corrupted) {
807 			ubi_err("corrupted dynamic volume");
808 			goto fail;
809 		}
810 		if (vol->used_ebs != vol->reserved_pebs) {
811 			ubi_err("bad used_ebs");
812 			goto fail;
813 		}
814 		if (vol->last_eb_bytes != vol->usable_leb_size) {
815 			ubi_err("bad last_eb_bytes");
816 			goto fail;
817 		}
818 		if (vol->used_bytes != n) {
819 			ubi_err("bad used_bytes");
820 			goto fail;
821 		}
822 	} else {
823 		if (vol->used_ebs < 0 || vol->used_ebs > vol->reserved_pebs) {
824 			ubi_err("bad used_ebs");
825 			goto fail;
826 		}
827 		if (vol->last_eb_bytes < 0 ||
828 		    vol->last_eb_bytes > vol->usable_leb_size) {
829 			ubi_err("bad last_eb_bytes");
830 			goto fail;
831 		}
832 		if (vol->used_bytes < 0 || vol->used_bytes > n ||
833 		    vol->used_bytes < n - vol->usable_leb_size) {
834 			ubi_err("bad used_bytes");
835 			goto fail;
836 		}
837 	}
838 
839 	alignment  = be32_to_cpu(ubi->vtbl[vol_id].alignment);
840 	data_pad   = be32_to_cpu(ubi->vtbl[vol_id].data_pad);
841 	name_len   = be16_to_cpu(ubi->vtbl[vol_id].name_len);
842 	upd_marker = ubi->vtbl[vol_id].upd_marker;
843 	name       = &ubi->vtbl[vol_id].name[0];
844 	if (ubi->vtbl[vol_id].vol_type == UBI_VID_DYNAMIC)
845 		vol_type = UBI_DYNAMIC_VOLUME;
846 	else
847 		vol_type = UBI_STATIC_VOLUME;
848 
849 	if (alignment != vol->alignment || data_pad != vol->data_pad ||
850 	    upd_marker != vol->upd_marker || vol_type != vol->vol_type ||
851 	    name_len != vol->name_len || strncmp(name, vol->name, name_len)) {
852 		ubi_err("volume info is different");
853 		goto fail;
854 	}
855 
856 	spin_unlock(&ubi->volumes_lock);
857 	return 0;
858 
859 fail:
860 	ubi_err("paranoid check failed for volume %d", vol_id);
861 	if (vol)
862 		ubi_dbg_dump_vol_info(vol);
863 	ubi_dbg_dump_vtbl_record(&ubi->vtbl[vol_id], vol_id);
864 	dump_stack();
865 	spin_unlock(&ubi->volumes_lock);
866 	return -EINVAL;
867 }
868 
869 /**
870  * paranoid_check_volumes - check information about all volumes.
871  * @ubi: UBI device description object
872  *
873  * Returns zero if volumes are all right and a a negative error code if not.
874  */
875 static int paranoid_check_volumes(struct ubi_device *ubi)
876 {
877 	int i, err = 0;
878 
879 	for (i = 0; i < ubi->vtbl_slots; i++) {
880 		err = paranoid_check_volume(ubi, i);
881 		if (err)
882 			break;
883 	}
884 
885 	return err;
886 }
887 #endif
888