drivers/mtd/ubi/vmt.c

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