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