xref: /openbmc/u-boot/drivers/mtd/ubi/vmt.c (revision d275c40c)
1 /*
2  * Copyright (c) International Business Machines Corp., 2006
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  *
6  * Author: Artem Bityutskiy (Битюцкий Артём)
7  */
8 
9 /*
10  * This file contains implementation of volume creation, deletion, updating and
11  * resizing.
12  */
13 
14 #ifndef __UBOOT__
15 #include <linux/err.h>
16 #include <linux/slab.h>
17 #include <linux/export.h>
18 #else
19 #include <div64.h>
20 #include <ubi_uboot.h>
21 #endif
22 #include <linux/math64.h>
23 
24 #include "ubi.h"
25 
26 static int self_check_volumes(struct ubi_device *ubi);
27 
28 #ifndef __UBOOT__
29 static ssize_t vol_attribute_show(struct device *dev,
30 				  struct device_attribute *attr, char *buf);
31 
32 /* Device attributes corresponding to files in '/<sysfs>/class/ubi/ubiX_Y' */
33 static struct device_attribute attr_vol_reserved_ebs =
34 	__ATTR(reserved_ebs, S_IRUGO, vol_attribute_show, NULL);
35 static struct device_attribute attr_vol_type =
36 	__ATTR(type, S_IRUGO, vol_attribute_show, NULL);
37 static struct device_attribute attr_vol_name =
38 	__ATTR(name, S_IRUGO, vol_attribute_show, NULL);
39 static struct device_attribute attr_vol_corrupted =
40 	__ATTR(corrupted, S_IRUGO, vol_attribute_show, NULL);
41 static struct device_attribute attr_vol_alignment =
42 	__ATTR(alignment, S_IRUGO, vol_attribute_show, NULL);
43 static struct device_attribute attr_vol_usable_eb_size =
44 	__ATTR(usable_eb_size, S_IRUGO, vol_attribute_show, NULL);
45 static struct device_attribute attr_vol_data_bytes =
46 	__ATTR(data_bytes, S_IRUGO, vol_attribute_show, NULL);
47 static struct device_attribute attr_vol_upd_marker =
48 	__ATTR(upd_marker, S_IRUGO, vol_attribute_show, NULL);
49 
50 /*
51  * "Show" method for files in '/<sysfs>/class/ubi/ubiX_Y/'.
52  *
53  * Consider a situation:
54  * A. process 1 opens a sysfs file related to volume Y, say
55  *    /<sysfs>/class/ubi/ubiX_Y/reserved_ebs;
56  * B. process 2 removes volume Y;
57  * C. process 1 starts reading the /<sysfs>/class/ubi/ubiX_Y/reserved_ebs file;
58  *
59  * In this situation, this function will return %-ENODEV because it will find
60  * out that the volume was removed from the @ubi->volumes array.
61  */
62 static ssize_t vol_attribute_show(struct device *dev,
63 				  struct device_attribute *attr, char *buf)
64 {
65 	int ret;
66 	struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev);
67 	struct ubi_device *ubi;
68 
69 	ubi = ubi_get_device(vol->ubi->ubi_num);
70 	if (!ubi)
71 		return -ENODEV;
72 
73 	spin_lock(&ubi->volumes_lock);
74 	if (!ubi->volumes[vol->vol_id]) {
75 		spin_unlock(&ubi->volumes_lock);
76 		ubi_put_device(ubi);
77 		return -ENODEV;
78 	}
79 	/* Take a reference to prevent volume removal */
80 	vol->ref_count += 1;
81 	spin_unlock(&ubi->volumes_lock);
82 
83 	if (attr == &attr_vol_reserved_ebs)
84 		ret = sprintf(buf, "%d\n", vol->reserved_pebs);
85 	else if (attr == &attr_vol_type) {
86 		const char *tp;
87 
88 		if (vol->vol_type == UBI_DYNAMIC_VOLUME)
89 			tp = "dynamic";
90 		else
91 			tp = "static";
92 		ret = sprintf(buf, "%s\n", tp);
93 	} else if (attr == &attr_vol_name)
94 		ret = sprintf(buf, "%s\n", vol->name);
95 	else if (attr == &attr_vol_corrupted)
96 		ret = sprintf(buf, "%d\n", vol->corrupted);
97 	else if (attr == &attr_vol_alignment)
98 		ret = sprintf(buf, "%d\n", vol->alignment);
99 	else if (attr == &attr_vol_usable_eb_size)
100 		ret = sprintf(buf, "%d\n", vol->usable_leb_size);
101 	else if (attr == &attr_vol_data_bytes)
102 		ret = sprintf(buf, "%lld\n", vol->used_bytes);
103 	else if (attr == &attr_vol_upd_marker)
104 		ret = sprintf(buf, "%d\n", vol->upd_marker);
105 	else
106 		/* This must be a bug */
107 		ret = -EINVAL;
108 
109 	/* We've done the operation, drop volume and UBI device references */
110 	spin_lock(&ubi->volumes_lock);
111 	vol->ref_count -= 1;
112 	ubi_assert(vol->ref_count >= 0);
113 	spin_unlock(&ubi->volumes_lock);
114 	ubi_put_device(ubi);
115 	return ret;
116 }
117 #endif
118 
119 /* Release method for volume devices */
120 static void vol_release(struct device *dev)
121 {
122 	struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev);
123 
124 	kfree(vol->eba_tbl);
125 	kfree(vol);
126 }
127 
128 #ifndef __UBOOT__
129 /**
130  * volume_sysfs_init - initialize sysfs for new volume.
131  * @ubi: UBI device description object
132  * @vol: volume description object
133  *
134  * This function returns zero in case of success and a negative error code in
135  * case of failure.
136  *
137  * Note, this function does not free allocated resources in case of failure -
138  * the caller does it. This is because this would cause release() here and the
139  * caller would oops.
140  */
141 static int volume_sysfs_init(struct ubi_device *ubi, struct ubi_volume *vol)
142 {
143 	int err;
144 
145 	err = device_create_file(&vol->dev, &attr_vol_reserved_ebs);
146 	if (err)
147 		return err;
148 	err = device_create_file(&vol->dev, &attr_vol_type);
149 	if (err)
150 		return err;
151 	err = device_create_file(&vol->dev, &attr_vol_name);
152 	if (err)
153 		return err;
154 	err = device_create_file(&vol->dev, &attr_vol_corrupted);
155 	if (err)
156 		return err;
157 	err = device_create_file(&vol->dev, &attr_vol_alignment);
158 	if (err)
159 		return err;
160 	err = device_create_file(&vol->dev, &attr_vol_usable_eb_size);
161 	if (err)
162 		return err;
163 	err = device_create_file(&vol->dev, &attr_vol_data_bytes);
164 	if (err)
165 		return err;
166 	err = device_create_file(&vol->dev, &attr_vol_upd_marker);
167 	return err;
168 }
169 
170 /**
171  * volume_sysfs_close - close sysfs for a volume.
172  * @vol: volume description object
173  */
174 static void volume_sysfs_close(struct ubi_volume *vol)
175 {
176 	device_remove_file(&vol->dev, &attr_vol_upd_marker);
177 	device_remove_file(&vol->dev, &attr_vol_data_bytes);
178 	device_remove_file(&vol->dev, &attr_vol_usable_eb_size);
179 	device_remove_file(&vol->dev, &attr_vol_alignment);
180 	device_remove_file(&vol->dev, &attr_vol_corrupted);
181 	device_remove_file(&vol->dev, &attr_vol_name);
182 	device_remove_file(&vol->dev, &attr_vol_type);
183 	device_remove_file(&vol->dev, &attr_vol_reserved_ebs);
184 	device_unregister(&vol->dev);
185 }
186 #endif
187 
188 /**
189  * ubi_create_volume - create volume.
190  * @ubi: UBI device description object
191  * @req: volume creation request
192  *
193  * This function creates volume described by @req. If @req->vol_id id
194  * %UBI_VOL_NUM_AUTO, this function automatically assign ID to the new volume
195  * and saves it in @req->vol_id. Returns zero in case of success and a negative
196  * error code in case of failure. Note, the caller has to have the
197  * @ubi->device_mutex locked.
198  */
199 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
200 {
201 	int i, err, vol_id = req->vol_id, do_free = 1;
202 	struct ubi_volume *vol;
203 	struct ubi_vtbl_record vtbl_rec;
204 	dev_t dev;
205 
206 	if (ubi->ro_mode)
207 		return -EROFS;
208 
209 	vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL);
210 	if (!vol)
211 		return -ENOMEM;
212 
213 	spin_lock(&ubi->volumes_lock);
214 	if (vol_id == UBI_VOL_NUM_AUTO) {
215 		/* Find unused volume ID */
216 		dbg_gen("search for vacant volume ID");
217 		for (i = 0; i < ubi->vtbl_slots; i++)
218 			if (!ubi->volumes[i]) {
219 				vol_id = i;
220 				break;
221 			}
222 
223 		if (vol_id == UBI_VOL_NUM_AUTO) {
224 			ubi_err("out of volume IDs");
225 			err = -ENFILE;
226 			goto out_unlock;
227 		}
228 		req->vol_id = vol_id;
229 	}
230 
231 	dbg_gen("create device %d, volume %d, %llu bytes, type %d, name %s",
232 		ubi->ubi_num, vol_id, (unsigned long long)req->bytes,
233 		(int)req->vol_type, req->name);
234 
235 	/* Ensure that this volume does not exist */
236 	err = -EEXIST;
237 	if (ubi->volumes[vol_id]) {
238 		ubi_err("volume %d already exists", vol_id);
239 		goto out_unlock;
240 	}
241 
242 	/* Ensure that the name is unique */
243 	for (i = 0; i < ubi->vtbl_slots; i++)
244 		if (ubi->volumes[i] &&
245 		    ubi->volumes[i]->name_len == req->name_len &&
246 		    !strcmp(ubi->volumes[i]->name, req->name)) {
247 			ubi_err("volume \"%s\" exists (ID %d)", req->name, i);
248 			goto out_unlock;
249 		}
250 
251 	/* Calculate how many eraseblocks are requested */
252 	vol->usable_leb_size = ubi->leb_size - ubi->leb_size % req->alignment;
253 	vol->reserved_pebs += div_u64(req->bytes + vol->usable_leb_size - 1,
254 				      vol->usable_leb_size);
255 
256 	/* Reserve physical eraseblocks */
257 	if (vol->reserved_pebs > ubi->avail_pebs) {
258 		ubi_err("not enough PEBs, only %d available", ubi->avail_pebs);
259 		if (ubi->corr_peb_count)
260 			ubi_err("%d PEBs are corrupted and not used",
261 				ubi->corr_peb_count);
262 		err = -ENOSPC;
263 		goto out_unlock;
264 	}
265 	ubi->avail_pebs -= vol->reserved_pebs;
266 	ubi->rsvd_pebs += vol->reserved_pebs;
267 	spin_unlock(&ubi->volumes_lock);
268 
269 	vol->vol_id    = vol_id;
270 	vol->alignment = req->alignment;
271 	vol->data_pad  = ubi->leb_size % vol->alignment;
272 	vol->vol_type  = req->vol_type;
273 	vol->name_len  = req->name_len;
274 	memcpy(vol->name, req->name, vol->name_len);
275 	vol->ubi = ubi;
276 
277 	/*
278 	 * Finish all pending erases because there may be some LEBs belonging
279 	 * to the same volume ID.
280 	 */
281 	err = ubi_wl_flush(ubi, vol_id, UBI_ALL);
282 	if (err)
283 		goto out_acc;
284 
285 	vol->eba_tbl = kmalloc(vol->reserved_pebs * sizeof(int), GFP_KERNEL);
286 	if (!vol->eba_tbl) {
287 		err = -ENOMEM;
288 		goto out_acc;
289 	}
290 
291 	for (i = 0; i < vol->reserved_pebs; i++)
292 		vol->eba_tbl[i] = UBI_LEB_UNMAPPED;
293 
294 	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
295 		vol->used_ebs = vol->reserved_pebs;
296 		vol->last_eb_bytes = vol->usable_leb_size;
297 		vol->used_bytes =
298 			(long long)vol->used_ebs * vol->usable_leb_size;
299 	} else {
300 		vol->used_ebs = div_u64_rem(vol->used_bytes,
301 					    vol->usable_leb_size,
302 					    &vol->last_eb_bytes);
303 		if (vol->last_eb_bytes != 0)
304 			vol->used_ebs += 1;
305 		else
306 			vol->last_eb_bytes = vol->usable_leb_size;
307 	}
308 
309 	/* Register character device for the volume */
310 	cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
311 	vol->cdev.owner = THIS_MODULE;
312 	dev = MKDEV(MAJOR(ubi->cdev.dev), vol_id + 1);
313 	err = cdev_add(&vol->cdev, dev, 1);
314 	if (err) {
315 		ubi_err("cannot add character device");
316 		goto out_mapping;
317 	}
318 
319 	vol->dev.release = vol_release;
320 	vol->dev.parent = &ubi->dev;
321 	vol->dev.devt = dev;
322 	vol->dev.class = ubi_class;
323 
324 	dev_set_name(&vol->dev, "%s_%d", ubi->ubi_name, vol->vol_id);
325 	err = device_register(&vol->dev);
326 	if (err) {
327 		ubi_err("cannot register device");
328 		goto out_cdev;
329 	}
330 
331 	err = volume_sysfs_init(ubi, vol);
332 	if (err)
333 		goto out_sysfs;
334 
335 	/* Fill volume table record */
336 	memset(&vtbl_rec, 0, sizeof(struct ubi_vtbl_record));
337 	vtbl_rec.reserved_pebs = cpu_to_be32(vol->reserved_pebs);
338 	vtbl_rec.alignment     = cpu_to_be32(vol->alignment);
339 	vtbl_rec.data_pad      = cpu_to_be32(vol->data_pad);
340 	vtbl_rec.name_len      = cpu_to_be16(vol->name_len);
341 	if (vol->vol_type == UBI_DYNAMIC_VOLUME)
342 		vtbl_rec.vol_type = UBI_VID_DYNAMIC;
343 	else
344 		vtbl_rec.vol_type = UBI_VID_STATIC;
345 	memcpy(vtbl_rec.name, vol->name, vol->name_len);
346 
347 	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
348 	if (err)
349 		goto out_sysfs;
350 
351 	spin_lock(&ubi->volumes_lock);
352 	ubi->volumes[vol_id] = vol;
353 	ubi->vol_count += 1;
354 	spin_unlock(&ubi->volumes_lock);
355 
356 	ubi_volume_notify(ubi, vol, UBI_VOLUME_ADDED);
357 	self_check_volumes(ubi);
358 	return err;
359 
360 out_sysfs:
361 	/*
362 	 * We have registered our device, we should not free the volume
363 	 * description object in this function in case of an error - it is
364 	 * freed by the release function.
365 	 *
366 	 * Get device reference to prevent the release function from being
367 	 * called just after sysfs has been closed.
368 	 */
369 	do_free = 0;
370 	get_device(&vol->dev);
371 	volume_sysfs_close(vol);
372 out_cdev:
373 	cdev_del(&vol->cdev);
374 out_mapping:
375 	if (do_free)
376 		kfree(vol->eba_tbl);
377 out_acc:
378 	spin_lock(&ubi->volumes_lock);
379 	ubi->rsvd_pebs -= vol->reserved_pebs;
380 	ubi->avail_pebs += vol->reserved_pebs;
381 out_unlock:
382 	spin_unlock(&ubi->volumes_lock);
383 	if (do_free)
384 		kfree(vol);
385 	else
386 		put_device(&vol->dev);
387 	ubi_err("cannot create volume %d, error %d", vol_id, err);
388 	return err;
389 }
390 
391 /**
392  * ubi_remove_volume - remove volume.
393  * @desc: volume descriptor
394  * @no_vtbl: do not change volume table if not zero
395  *
396  * This function removes volume described by @desc. The volume has to be opened
397  * in "exclusive" mode. Returns zero in case of success and a negative error
398  * code in case of failure. The caller has to have the @ubi->device_mutex
399  * locked.
400  */
401 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl)
402 {
403 	struct ubi_volume *vol = desc->vol;
404 	struct ubi_device *ubi = vol->ubi;
405 	int i, err, vol_id = vol->vol_id, reserved_pebs = vol->reserved_pebs;
406 
407 	dbg_gen("remove device %d, volume %d", ubi->ubi_num, vol_id);
408 	ubi_assert(desc->mode == UBI_EXCLUSIVE);
409 	ubi_assert(vol == ubi->volumes[vol_id]);
410 
411 	if (ubi->ro_mode)
412 		return -EROFS;
413 
414 	spin_lock(&ubi->volumes_lock);
415 	if (vol->ref_count > 1) {
416 		/*
417 		 * The volume is busy, probably someone is reading one of its
418 		 * sysfs files.
419 		 */
420 		err = -EBUSY;
421 		goto out_unlock;
422 	}
423 	ubi->volumes[vol_id] = NULL;
424 	spin_unlock(&ubi->volumes_lock);
425 
426 	if (!no_vtbl) {
427 		err = ubi_change_vtbl_record(ubi, vol_id, NULL);
428 		if (err)
429 			goto out_err;
430 	}
431 
432 	for (i = 0; i < vol->reserved_pebs; i++) {
433 		err = ubi_eba_unmap_leb(ubi, vol, i);
434 		if (err)
435 			goto out_err;
436 	}
437 
438 	cdev_del(&vol->cdev);
439 	volume_sysfs_close(vol);
440 
441 	spin_lock(&ubi->volumes_lock);
442 	ubi->rsvd_pebs -= reserved_pebs;
443 	ubi->avail_pebs += reserved_pebs;
444 	ubi_update_reserved(ubi);
445 	ubi->vol_count -= 1;
446 	spin_unlock(&ubi->volumes_lock);
447 
448 	ubi_volume_notify(ubi, vol, UBI_VOLUME_REMOVED);
449 	if (!no_vtbl)
450 		self_check_volumes(ubi);
451 
452 	return err;
453 
454 out_err:
455 	ubi_err("cannot remove volume %d, error %d", vol_id, err);
456 	spin_lock(&ubi->volumes_lock);
457 	ubi->volumes[vol_id] = vol;
458 out_unlock:
459 	spin_unlock(&ubi->volumes_lock);
460 	return err;
461 }
462 
463 /**
464  * ubi_resize_volume - re-size volume.
465  * @desc: volume descriptor
466  * @reserved_pebs: new size in physical eraseblocks
467  *
468  * This function re-sizes the volume and returns zero in case of success, and a
469  * negative error code in case of failure. The caller has to have the
470  * @ubi->device_mutex locked.
471  */
472 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs)
473 {
474 	int i, err, pebs, *new_mapping;
475 	struct ubi_volume *vol = desc->vol;
476 	struct ubi_device *ubi = vol->ubi;
477 	struct ubi_vtbl_record vtbl_rec;
478 	int vol_id = vol->vol_id;
479 
480 	if (ubi->ro_mode)
481 		return -EROFS;
482 
483 	dbg_gen("re-size device %d, volume %d to from %d to %d PEBs",
484 		ubi->ubi_num, vol_id, vol->reserved_pebs, reserved_pebs);
485 
486 	if (vol->vol_type == UBI_STATIC_VOLUME &&
487 	    reserved_pebs < vol->used_ebs) {
488 		ubi_err("too small size %d, %d LEBs contain data",
489 			reserved_pebs, vol->used_ebs);
490 		return -EINVAL;
491 	}
492 
493 	/* If the size is the same, we have nothing to do */
494 	if (reserved_pebs == vol->reserved_pebs)
495 		return 0;
496 
497 	new_mapping = kmalloc(reserved_pebs * sizeof(int), GFP_KERNEL);
498 	if (!new_mapping)
499 		return -ENOMEM;
500 
501 	for (i = 0; i < reserved_pebs; i++)
502 		new_mapping[i] = UBI_LEB_UNMAPPED;
503 
504 	spin_lock(&ubi->volumes_lock);
505 	if (vol->ref_count > 1) {
506 		spin_unlock(&ubi->volumes_lock);
507 		err = -EBUSY;
508 		goto out_free;
509 	}
510 	spin_unlock(&ubi->volumes_lock);
511 
512 	/* Reserve physical eraseblocks */
513 	pebs = reserved_pebs - vol->reserved_pebs;
514 	if (pebs > 0) {
515 		spin_lock(&ubi->volumes_lock);
516 		if (pebs > ubi->avail_pebs) {
517 			ubi_err("not enough PEBs: requested %d, available %d",
518 				pebs, ubi->avail_pebs);
519 			if (ubi->corr_peb_count)
520 				ubi_err("%d PEBs are corrupted and not used",
521 					ubi->corr_peb_count);
522 			spin_unlock(&ubi->volumes_lock);
523 			err = -ENOSPC;
524 			goto out_free;
525 		}
526 		ubi->avail_pebs -= pebs;
527 		ubi->rsvd_pebs += pebs;
528 		for (i = 0; i < vol->reserved_pebs; i++)
529 			new_mapping[i] = vol->eba_tbl[i];
530 		kfree(vol->eba_tbl);
531 		vol->eba_tbl = new_mapping;
532 		spin_unlock(&ubi->volumes_lock);
533 	}
534 
535 	/* Change volume table record */
536 	vtbl_rec = ubi->vtbl[vol_id];
537 	vtbl_rec.reserved_pebs = cpu_to_be32(reserved_pebs);
538 	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
539 	if (err)
540 		goto out_acc;
541 
542 	if (pebs < 0) {
543 		for (i = 0; i < -pebs; i++) {
544 			err = ubi_eba_unmap_leb(ubi, vol, reserved_pebs + i);
545 			if (err)
546 				goto out_acc;
547 		}
548 		spin_lock(&ubi->volumes_lock);
549 		ubi->rsvd_pebs += pebs;
550 		ubi->avail_pebs -= pebs;
551 		ubi_update_reserved(ubi);
552 		for (i = 0; i < reserved_pebs; i++)
553 			new_mapping[i] = vol->eba_tbl[i];
554 		kfree(vol->eba_tbl);
555 		vol->eba_tbl = new_mapping;
556 		spin_unlock(&ubi->volumes_lock);
557 	}
558 
559 	vol->reserved_pebs = reserved_pebs;
560 	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
561 		vol->used_ebs = reserved_pebs;
562 		vol->last_eb_bytes = vol->usable_leb_size;
563 		vol->used_bytes =
564 			(long long)vol->used_ebs * vol->usable_leb_size;
565 	}
566 
567 	ubi_volume_notify(ubi, vol, UBI_VOLUME_RESIZED);
568 	self_check_volumes(ubi);
569 	return err;
570 
571 out_acc:
572 	if (pebs > 0) {
573 		spin_lock(&ubi->volumes_lock);
574 		ubi->rsvd_pebs -= pebs;
575 		ubi->avail_pebs += pebs;
576 		spin_unlock(&ubi->volumes_lock);
577 	}
578 out_free:
579 	kfree(new_mapping);
580 	return err;
581 }
582 
583 /**
584  * ubi_rename_volumes - re-name UBI volumes.
585  * @ubi: UBI device description object
586  * @rename_list: list of &struct ubi_rename_entry objects
587  *
588  * This function re-names or removes volumes specified in the re-name list.
589  * Returns zero in case of success and a negative error code in case of
590  * failure.
591  */
592 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list)
593 {
594 	int err;
595 	struct ubi_rename_entry *re;
596 
597 	err = ubi_vtbl_rename_volumes(ubi, rename_list);
598 	if (err)
599 		return err;
600 
601 	list_for_each_entry(re, rename_list, list) {
602 		if (re->remove) {
603 			err = ubi_remove_volume(re->desc, 1);
604 			if (err)
605 				break;
606 		} else {
607 			struct ubi_volume *vol = re->desc->vol;
608 
609 			spin_lock(&ubi->volumes_lock);
610 			vol->name_len = re->new_name_len;
611 			memcpy(vol->name, re->new_name, re->new_name_len + 1);
612 			spin_unlock(&ubi->volumes_lock);
613 			ubi_volume_notify(ubi, vol, UBI_VOLUME_RENAMED);
614 		}
615 	}
616 
617 	if (!err)
618 		self_check_volumes(ubi);
619 	return err;
620 }
621 
622 /**
623  * ubi_add_volume - add volume.
624  * @ubi: UBI device description object
625  * @vol: volume description object
626  *
627  * This function adds an existing volume and initializes all its data
628  * structures. Returns zero in case of success and a negative error code in
629  * case of failure.
630  */
631 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol)
632 {
633 	int err, vol_id = vol->vol_id;
634 	dev_t dev;
635 
636 	dbg_gen("add volume %d", vol_id);
637 
638 	/* Register character device for the volume */
639 	cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
640 	vol->cdev.owner = THIS_MODULE;
641 	dev = MKDEV(MAJOR(ubi->cdev.dev), vol->vol_id + 1);
642 	err = cdev_add(&vol->cdev, dev, 1);
643 	if (err) {
644 		ubi_err("cannot add character device for volume %d, error %d",
645 			vol_id, err);
646 		return err;
647 	}
648 
649 	vol->dev.release = vol_release;
650 	vol->dev.parent = &ubi->dev;
651 	vol->dev.devt = dev;
652 	vol->dev.class = ubi_class;
653 	dev_set_name(&vol->dev, "%s_%d", ubi->ubi_name, vol->vol_id);
654 	err = device_register(&vol->dev);
655 	if (err)
656 		goto out_cdev;
657 
658 	err = volume_sysfs_init(ubi, vol);
659 	if (err) {
660 		cdev_del(&vol->cdev);
661 		volume_sysfs_close(vol);
662 		return err;
663 	}
664 
665 	self_check_volumes(ubi);
666 	return err;
667 
668 out_cdev:
669 	cdev_del(&vol->cdev);
670 	return err;
671 }
672 
673 /**
674  * ubi_free_volume - free volume.
675  * @ubi: UBI device description object
676  * @vol: volume description object
677  *
678  * This function frees all resources for volume @vol but does not remove it.
679  * Used only when the UBI device is detached.
680  */
681 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol)
682 {
683 	dbg_gen("free volume %d", vol->vol_id);
684 
685 	ubi->volumes[vol->vol_id] = NULL;
686 	cdev_del(&vol->cdev);
687 	volume_sysfs_close(vol);
688 }
689 
690 /**
691  * self_check_volume - check volume information.
692  * @ubi: UBI device description object
693  * @vol_id: volume ID
694  *
695  * Returns zero if volume is all right and a a negative error code if not.
696  */
697 static int self_check_volume(struct ubi_device *ubi, int vol_id)
698 {
699 	int idx = vol_id2idx(ubi, vol_id);
700 	int reserved_pebs, alignment, data_pad, vol_type, name_len, upd_marker;
701 	const struct ubi_volume *vol;
702 	long long n;
703 	const char *name;
704 
705 	spin_lock(&ubi->volumes_lock);
706 	reserved_pebs = be32_to_cpu(ubi->vtbl[vol_id].reserved_pebs);
707 	vol = ubi->volumes[idx];
708 
709 	if (!vol) {
710 		if (reserved_pebs) {
711 			ubi_err("no volume info, but volume exists");
712 			goto fail;
713 		}
714 		spin_unlock(&ubi->volumes_lock);
715 		return 0;
716 	}
717 
718 	if (vol->reserved_pebs < 0 || vol->alignment < 0 || vol->data_pad < 0 ||
719 	    vol->name_len < 0) {
720 		ubi_err("negative values");
721 		goto fail;
722 	}
723 	if (vol->alignment > ubi->leb_size || vol->alignment == 0) {
724 		ubi_err("bad alignment");
725 		goto fail;
726 	}
727 
728 	n = vol->alignment & (ubi->min_io_size - 1);
729 	if (vol->alignment != 1 && n) {
730 		ubi_err("alignment is not multiple of min I/O unit");
731 		goto fail;
732 	}
733 
734 	n = ubi->leb_size % vol->alignment;
735 	if (vol->data_pad != n) {
736 		ubi_err("bad data_pad, has to be %lld", n);
737 		goto fail;
738 	}
739 
740 	if (vol->vol_type != UBI_DYNAMIC_VOLUME &&
741 	    vol->vol_type != UBI_STATIC_VOLUME) {
742 		ubi_err("bad vol_type");
743 		goto fail;
744 	}
745 
746 	if (vol->upd_marker && vol->corrupted) {
747 		ubi_err("update marker and corrupted simultaneously");
748 		goto fail;
749 	}
750 
751 	if (vol->reserved_pebs > ubi->good_peb_count) {
752 		ubi_err("too large reserved_pebs");
753 		goto fail;
754 	}
755 
756 	n = ubi->leb_size - vol->data_pad;
757 	if (vol->usable_leb_size != ubi->leb_size - vol->data_pad) {
758 		ubi_err("bad usable_leb_size, has to be %lld", n);
759 		goto fail;
760 	}
761 
762 	if (vol->name_len > UBI_VOL_NAME_MAX) {
763 		ubi_err("too long volume name, max is %d", UBI_VOL_NAME_MAX);
764 		goto fail;
765 	}
766 
767 	n = strnlen(vol->name, vol->name_len + 1);
768 	if (n != vol->name_len) {
769 		ubi_err("bad name_len %lld", n);
770 		goto fail;
771 	}
772 
773 	n = (long long)vol->used_ebs * vol->usable_leb_size;
774 	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
775 		if (vol->corrupted) {
776 			ubi_err("corrupted dynamic volume");
777 			goto fail;
778 		}
779 		if (vol->used_ebs != vol->reserved_pebs) {
780 			ubi_err("bad used_ebs");
781 			goto fail;
782 		}
783 		if (vol->last_eb_bytes != vol->usable_leb_size) {
784 			ubi_err("bad last_eb_bytes");
785 			goto fail;
786 		}
787 		if (vol->used_bytes != n) {
788 			ubi_err("bad used_bytes");
789 			goto fail;
790 		}
791 	} else {
792 		if (vol->used_ebs < 0 || vol->used_ebs > vol->reserved_pebs) {
793 			ubi_err("bad used_ebs");
794 			goto fail;
795 		}
796 		if (vol->last_eb_bytes < 0 ||
797 		    vol->last_eb_bytes > vol->usable_leb_size) {
798 			ubi_err("bad last_eb_bytes");
799 			goto fail;
800 		}
801 		if (vol->used_bytes < 0 || vol->used_bytes > n ||
802 		    vol->used_bytes < n - vol->usable_leb_size) {
803 			ubi_err("bad used_bytes");
804 			goto fail;
805 		}
806 	}
807 
808 	alignment  = be32_to_cpu(ubi->vtbl[vol_id].alignment);
809 	data_pad   = be32_to_cpu(ubi->vtbl[vol_id].data_pad);
810 	name_len   = be16_to_cpu(ubi->vtbl[vol_id].name_len);
811 	upd_marker = ubi->vtbl[vol_id].upd_marker;
812 	name       = &ubi->vtbl[vol_id].name[0];
813 	if (ubi->vtbl[vol_id].vol_type == UBI_VID_DYNAMIC)
814 		vol_type = UBI_DYNAMIC_VOLUME;
815 	else
816 		vol_type = UBI_STATIC_VOLUME;
817 
818 	if (alignment != vol->alignment || data_pad != vol->data_pad ||
819 	    upd_marker != vol->upd_marker || vol_type != vol->vol_type ||
820 	    name_len != vol->name_len || strncmp(name, vol->name, name_len)) {
821 		ubi_err("volume info is different");
822 		goto fail;
823 	}
824 
825 	spin_unlock(&ubi->volumes_lock);
826 	return 0;
827 
828 fail:
829 	ubi_err("self-check failed for volume %d", vol_id);
830 	if (vol)
831 		ubi_dump_vol_info(vol);
832 	ubi_dump_vtbl_record(&ubi->vtbl[vol_id], vol_id);
833 	dump_stack();
834 	spin_unlock(&ubi->volumes_lock);
835 	return -EINVAL;
836 }
837 
838 /**
839  * self_check_volumes - check information about all volumes.
840  * @ubi: UBI device description object
841  *
842  * Returns zero if volumes are all right and a a negative error code if not.
843  */
844 static int self_check_volumes(struct ubi_device *ubi)
845 {
846 	int i, err = 0;
847 
848 	if (!ubi_dbg_chk_gen(ubi))
849 		return 0;
850 
851 	for (i = 0; i < ubi->vtbl_slots; i++) {
852 		err = self_check_volume(ubi, i);
853 		if (err)
854 			break;
855 	}
856 
857 	return err;
858 }
859