drivers/mtd/ubi/vmt.c

   1 /*
   2  * Copyright (c) International Business Machines Corp., 2006
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation;  either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
  12  * the GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  17  *
  18  * Author: Artem Bityutskiy (Битюцкий Артём)
  19  */
  20
  21 /*
  22  * This file contains implementation of volume creation, deletion, updating and
  23  * resizing.
  24  */
  25
  26 #include <linux/err.h>
  27 #include <linux/math64.h>
  28 #include <linux/slab.h>
  29 #include <linux/export.h>
  30 #include "ubi.h"
  31
  32 static int self_check_volumes(struct ubi_device *ubi);
  33
  34 static ssize_t vol_attribute_show(struct device *dev,
  35                                   struct device_attribute *attr, char *buf);
  36
  37 /* Device attributes corresponding to files in '/<sysfs>/class/ubi/ubiX_Y' */
  38 static struct device_attribute attr_vol_reserved_ebs =
  39         __ATTR(reserved_ebs, S_IRUGO, vol_attribute_show, NULL);
  40 static struct device_attribute attr_vol_type =
  41         __ATTR(type, S_IRUGO, vol_attribute_show, NULL);
  42 static struct device_attribute attr_vol_name =
  43         __ATTR(name, S_IRUGO, vol_attribute_show, NULL);
  44 static struct device_attribute attr_vol_corrupted =
  45         __ATTR(corrupted, S_IRUGO, vol_attribute_show, NULL);
  46 static struct device_attribute attr_vol_alignment =
  47         __ATTR(alignment, S_IRUGO, vol_attribute_show, NULL);
  48 static struct device_attribute attr_vol_usable_eb_size =
  49         __ATTR(usable_eb_size, S_IRUGO, vol_attribute_show, NULL);
  50 static struct device_attribute attr_vol_data_bytes =
  51         __ATTR(data_bytes, S_IRUGO, vol_attribute_show, NULL);
  52 static struct device_attribute attr_vol_upd_marker =
  53         __ATTR(upd_marker, S_IRUGO, vol_attribute_show, NULL);
  54
  55 /*
  56  * "Show" method for files in '/<sysfs>/class/ubi/ubiX_Y/'.
  57  *
  58  * Consider a situation:
  59  * A. process 1 opens a sysfs file related to volume Y, say
  60  *    /<sysfs>/class/ubi/ubiX_Y/reserved_ebs;
  61  * B. process 2 removes volume Y;
  62  * C. process 1 starts reading the /<sysfs>/class/ubi/ubiX_Y/reserved_ebs file;
  63  *
  64  * In this situation, this function will return %-ENODEV because it will find
  65  * out that the volume was removed from the @ubi->volumes array.
  66  */
  67 static ssize_t vol_attribute_show(struct device *dev,
  68                                   struct device_attribute *attr, char *buf)
  69 {
  70         int ret;
  71         struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev);
  72         struct ubi_device *ubi;
  73
  74         ubi = ubi_get_device(vol->ubi->ubi_num);
  75         if (!ubi)
  76                 return -ENODEV;
  77
  78         spin_lock(&ubi->volumes_lock);
  79         if (!ubi->volumes[vol->vol_id]) {
  80                 spin_unlock(&ubi->volumes_lock);
  81                 ubi_put_device(ubi);
  82                 return -ENODEV;
  83         }
  84         /* Take a reference to prevent volume removal */
  85         vol->ref_count += 1;
  86         spin_unlock(&ubi->volumes_lock);
  87
  88         if (attr == &attr_vol_reserved_ebs)
  89                 ret = sprintf(buf, "%d\n", vol->reserved_pebs);
  90         else if (attr == &attr_vol_type) {
  91                 const char *tp;
  92
  93                 if (vol->vol_type == UBI_DYNAMIC_VOLUME)
  94                         tp = "dynamic";
  95                 else
  96                         tp = "static";
  97                 ret = sprintf(buf, "%s\n", tp);
  98         } else if (attr == &attr_vol_name)
  99                 ret = sprintf(buf, "%s\n", vol->name);
 100         else if (attr == &attr_vol_corrupted)
 101                 ret = sprintf(buf, "%d\n", vol->corrupted);
 102         else if (attr == &attr_vol_alignment)
 103                 ret = sprintf(buf, "%d\n", vol->alignment);
 104         else if (attr == &attr_vol_usable_eb_size)
 105                 ret = sprintf(buf, "%d\n", vol->usable_leb_size);
 106         else if (attr == &attr_vol_data_bytes)
 107                 ret = sprintf(buf, "%lld\n", vol->used_bytes);
 108         else if (attr == &attr_vol_upd_marker)
 109                 ret = sprintf(buf, "%d\n", vol->upd_marker);
 110         else
 111                 /* This must be a bug */
 112                 ret = -EINVAL;
 113
 114         /* We've done the operation, drop volume and UBI device references */
 115         spin_lock(&ubi->volumes_lock);
 116         vol->ref_count -= 1;
 117         ubi_assert(vol->ref_count >= 0);
 118         spin_unlock(&ubi->volumes_lock);
 119         ubi_put_device(ubi);
 120         return ret;
 121 }
 122
 123 static struct attribute *volume_dev_attrs[] = {
 124         &attr_vol_reserved_ebs.attr,
 125         &attr_vol_type.attr,
 126         &attr_vol_name.attr,
 127         &attr_vol_corrupted.attr,
 128         &attr_vol_alignment.attr,
 129         &attr_vol_usable_eb_size.attr,
 130         &attr_vol_data_bytes.attr,
 131         &attr_vol_upd_marker.attr,
 132         NULL
 133 };
 134 ATTRIBUTE_GROUPS(volume_dev);
 135
 136 /* Release method for volume devices */
 137 static void vol_release(struct device *dev)
 138 {
 139         struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev);
 140
 141         kfree(vol->eba_tbl);
 142         kfree(vol);
 143 }
 144
 145 /**
 146  * ubi_create_volume - create volume.
 147  * @ubi: UBI device description object
 148  * @req: volume creation request
 149  *
 150  * This function creates volume described by @req. If @req->vol_id id
 151  * %UBI_VOL_NUM_AUTO, this function automatically assign ID to the new volume
 152  * and saves it in @req->vol_id. Returns zero in case of success and a negative
 153  * error code in case of failure. Note, the caller has to have the
 154  * @ubi->device_mutex locked.
 155  */
 156 int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
 157 {
 158         int i, err, vol_id = req->vol_id, do_free = 1;
 159         struct ubi_volume *vol;
 160         struct ubi_vtbl_record vtbl_rec;
 161         dev_t dev;
 162
 163         if (ubi->ro_mode)
 164                 return -EROFS;
 165
 166         vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL);
 167         if (!vol)
 168                 return -ENOMEM;
 169
 170         spin_lock(&ubi->volumes_lock);
 171         if (vol_id == UBI_VOL_NUM_AUTO) {
 172                 /* Find unused volume ID */
 173                 dbg_gen("search for vacant volume ID");
 174                 for (i = 0; i < ubi->vtbl_slots; i++)
 175                         if (!ubi->volumes[i]) {
 176                                 vol_id = i;
 177                                 break;
 178                         }
 179
 180                 if (vol_id == UBI_VOL_NUM_AUTO) {
 181                         ubi_err(ubi, "out of volume IDs");
 182                         err = -ENFILE;
 183                         goto out_unlock;
 184                 }
 185                 req->vol_id = vol_id;
 186         }
 187
 188         dbg_gen("create device %d, volume %d, %llu bytes, type %d, name %s",
 189                 ubi->ubi_num, vol_id, (unsigned long long)req->bytes,
 190                 (int)req->vol_type, req->name);
 191
 192         /* Ensure that this volume does not exist */
 193         err = -EEXIST;
 194         if (ubi->volumes[vol_id]) {
 195                 ubi_err(ubi, "volume %d already exists", vol_id);
 196                 goto out_unlock;
 197         }
 198
 199         /* Ensure that the name is unique */
 200         for (i = 0; i < ubi->vtbl_slots; i++)
 201                 if (ubi->volumes[i] &&
 202                     ubi->volumes[i]->name_len == req->name_len &&
 203                     !strcmp(ubi->volumes[i]->name, req->name)) {
 204                         ubi_err(ubi, "volume \"%s\" exists (ID %d)",
 205                                 req->name, i);
 206                         goto out_unlock;
 207                 }
 208
 209         /* Calculate how many eraseblocks are requested */
 210         vol->usable_leb_size = ubi->leb_size - ubi->leb_size % req->alignment;
 211         vol->reserved_pebs = div_u64(req->bytes + vol->usable_leb_size - 1,
 212                                      vol->usable_leb_size);
 213
 214         /* Reserve physical eraseblocks */
 215         if (vol->reserved_pebs > ubi->avail_pebs) {
 216                 ubi_err(ubi, "not enough PEBs, only %d available",
 217                         ubi->avail_pebs);
 218                 if (ubi->corr_peb_count)
 219                         ubi_err(ubi, "%d PEBs are corrupted and not used",
 220                                 ubi->corr_peb_count);
 221                 err = -ENOSPC;
 222                 goto out_unlock;
 223         }
 224         ubi->avail_pebs -= vol->reserved_pebs;
 225         ubi->rsvd_pebs += vol->reserved_pebs;
 226         spin_unlock(&ubi->volumes_lock);
 227
 228         vol->vol_id    = vol_id;
 229         vol->alignment = req->alignment;
 230         vol->data_pad  = ubi->leb_size % vol->alignment;
 231         vol->vol_type  = req->vol_type;
 232         vol->name_len  = req->name_len;
 233         memcpy(vol->name, req->name, vol->name_len);
 234         vol->ubi = ubi;
 235
 236         /*
 237          * Finish all pending erases because there may be some LEBs belonging
 238          * to the same volume ID.
 239          */
 240         err = ubi_wl_flush(ubi, vol_id, UBI_ALL);
 241         if (err)
 242                 goto out_acc;
 243
 244         vol->eba_tbl = kmalloc(vol->reserved_pebs * sizeof(int), GFP_KERNEL);
 245         if (!vol->eba_tbl) {
 246                 err = -ENOMEM;
 247                 goto out_acc;
 248         }
 249
 250         for (i = 0; i < vol->reserved_pebs; i++)
 251                 vol->eba_tbl[i] = UBI_LEB_UNMAPPED;
 252
 253         if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
 254                 vol->used_ebs = vol->reserved_pebs;
 255                 vol->last_eb_bytes = vol->usable_leb_size;
 256                 vol->used_bytes =
 257                         (long long)vol->used_ebs * vol->usable_leb_size;
 258         } else {
 259                 vol->used_ebs = div_u64_rem(vol->used_bytes,
 260                                             vol->usable_leb_size,
 261                                             &vol->last_eb_bytes);
 262                 if (vol->last_eb_bytes != 0)
 263                         vol->used_ebs += 1;
 264                 else
 265                         vol->last_eb_bytes = vol->usable_leb_size;
 266         }
 267
 268         /* Register character device for the volume */
 269         cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
 270         vol->cdev.owner = THIS_MODULE;
 271         dev = MKDEV(MAJOR(ubi->cdev.dev), vol_id + 1);
 272         err = cdev_add(&vol->cdev, dev, 1);
 273         if (err) {
 274                 ubi_err(ubi, "cannot add character device");
 275                 goto out_mapping;
 276         }
 277
 278         vol->dev.release = vol_release;
 279         vol->dev.parent = &ubi->dev;
 280         vol->dev.devt = dev;
 281         vol->dev.class = &ubi_class;
 282         vol->dev.groups = volume_dev_groups;
 283
 284         dev_set_name(&vol->dev, "%s_%d", ubi->ubi_name, vol->vol_id);
 285         err = device_register(&vol->dev);
 286         if (err) {
 287                 ubi_err(ubi, "cannot register device");
 288                 goto out_cdev;
 289         }
 290
 291         /* Fill volume table record */
 292         memset(&vtbl_rec, 0, sizeof(struct ubi_vtbl_record));
 293         vtbl_rec.reserved_pebs = cpu_to_be32(vol->reserved_pebs);
 294         vtbl_rec.alignment     = cpu_to_be32(vol->alignment);
 295         vtbl_rec.data_pad      = cpu_to_be32(vol->data_pad);
 296         vtbl_rec.name_len      = cpu_to_be16(vol->name_len);
 297         if (vol->vol_type == UBI_DYNAMIC_VOLUME)
 298                 vtbl_rec.vol_type = UBI_VID_DYNAMIC;
 299         else
 300                 vtbl_rec.vol_type = UBI_VID_STATIC;
 301         memcpy(vtbl_rec.name, vol->name, vol->name_len);
 302
 303         err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
 304         if (err)
 305                 goto out_sysfs;
 306
 307         spin_lock(&ubi->volumes_lock);
 308         ubi->volumes[vol_id] = vol;
 309         ubi->vol_count += 1;
 310         spin_unlock(&ubi->volumes_lock);
 311
 312         ubi_volume_notify(ubi, vol, UBI_VOLUME_ADDED);
 313         self_check_volumes(ubi);
 314         return err;
 315
 316 out_sysfs:
 317         /*
 318          * We have registered our device, we should not free the volume
 319          * description object in this function in case of an error - it is
 320          * freed by the release function.
 321          *
 322          * Get device reference to prevent the release function from being
 323          * called just after sysfs has been closed.
 324          */
 325         do_free = 0;
 326         get_device(&vol->dev);
 327         device_unregister(&vol->dev);
 328 out_cdev:
 329         cdev_del(&vol->cdev);
 330 out_mapping:
 331         if (do_free)
 332                 kfree(vol->eba_tbl);
 333 out_acc:
 334         spin_lock(&ubi->volumes_lock);
 335         ubi->rsvd_pebs -= vol->reserved_pebs;
 336         ubi->avail_pebs += vol->reserved_pebs;
 337 out_unlock:
 338         spin_unlock(&ubi->volumes_lock);
 339         if (do_free)
 340                 kfree(vol);
 341         else
 342                 put_device(&vol->dev);
 343         ubi_err(ubi, "cannot create volume %d, error %d", vol_id, err);
 344         return err;
 345 }
 346
 347 /**
 348  * ubi_remove_volume - remove volume.
 349  * @desc: volume descriptor
 350  * @no_vtbl: do not change volume table if not zero
 351  *
 352  * This function removes volume described by @desc. The volume has to be opened
 353  * in "exclusive" mode. Returns zero in case of success and a negative error
 354  * code in case of failure. The caller has to have the @ubi->device_mutex
 355  * locked.
 356  */
 357 int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl)
 358 {
 359         struct ubi_volume *vol = desc->vol;
 360         struct ubi_device *ubi = vol->ubi;
 361         int i, err, vol_id = vol->vol_id, reserved_pebs = vol->reserved_pebs;
 362
 363         dbg_gen("remove device %d, volume %d", ubi->ubi_num, vol_id);
 364         ubi_assert(desc->mode == UBI_EXCLUSIVE);
 365         ubi_assert(vol == ubi->volumes[vol_id]);
 366
 367         if (ubi->ro_mode)
 368                 return -EROFS;
 369
 370         spin_lock(&ubi->volumes_lock);
 371         if (vol->ref_count > 1) {
 372                 /*
 373                  * The volume is busy, probably someone is reading one of its
 374                  * sysfs files.
 375                  */
 376                 err = -EBUSY;
 377                 goto out_unlock;
 378         }
 379         ubi->volumes[vol_id] = NULL;
 380         spin_unlock(&ubi->volumes_lock);
 381
 382         if (!no_vtbl) {
 383                 err = ubi_change_vtbl_record(ubi, vol_id, NULL);
 384                 if (err)
 385                         goto out_err;
 386         }
 387
 388         for (i = 0; i < vol->reserved_pebs; i++) {
 389                 err = ubi_eba_unmap_leb(ubi, vol, i);
 390                 if (err)
 391                         goto out_err;
 392         }
 393
 394         cdev_del(&vol->cdev);
 395         device_unregister(&vol->dev);
 396
 397         spin_lock(&ubi->volumes_lock);
 398         ubi->rsvd_pebs -= reserved_pebs;
 399         ubi->avail_pebs += reserved_pebs;
 400         ubi_update_reserved(ubi);
 401         ubi->vol_count -= 1;
 402         spin_unlock(&ubi->volumes_lock);
 403
 404         ubi_volume_notify(ubi, vol, UBI_VOLUME_REMOVED);
 405         if (!no_vtbl)
 406                 self_check_volumes(ubi);
 407
 408         return 0;
 409
 410 out_err:
 411         ubi_err(ubi, "cannot remove volume %d, error %d", vol_id, err);
 412         spin_lock(&ubi->volumes_lock);
 413         ubi->volumes[vol_id] = vol;
 414 out_unlock:
 415         spin_unlock(&ubi->volumes_lock);
 416         return err;
 417 }
 418
 419 /**
 420  * ubi_resize_volume - re-size volume.
 421  * @desc: volume descriptor
 422  * @reserved_pebs: new size in physical eraseblocks
 423  *
 424  * This function re-sizes the volume and returns zero in case of success, and a
 425  * negative error code in case of failure. The caller has to have the
 426  * @ubi->device_mutex locked.
 427  */
 428 int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs)
 429 {
 430         int i, err, pebs, *new_mapping;
 431         struct ubi_volume *vol = desc->vol;
 432         struct ubi_device *ubi = vol->ubi;
 433         struct ubi_vtbl_record vtbl_rec;
 434         int vol_id = vol->vol_id;
 435
 436         if (ubi->ro_mode)
 437                 return -EROFS;
 438
 439         dbg_gen("re-size device %d, volume %d to from %d to %d PEBs",
 440                 ubi->ubi_num, vol_id, vol->reserved_pebs, reserved_pebs);
 441
 442         if (vol->vol_type == UBI_STATIC_VOLUME &&
 443             reserved_pebs < vol->used_ebs) {
 444                 ubi_err(ubi, "too small size %d, %d LEBs contain data",
 445                         reserved_pebs, vol->used_ebs);
 446                 return -EINVAL;
 447         }
 448
 449         /* If the size is the same, we have nothing to do */
 450         if (reserved_pebs == vol->reserved_pebs)
 451                 return 0;
 452
 453         new_mapping = kmalloc(reserved_pebs * sizeof(int), GFP_KERNEL);
 454         if (!new_mapping)
 455                 return -ENOMEM;
 456
 457         for (i = 0; i < reserved_pebs; i++)
 458                 new_mapping[i] = UBI_LEB_UNMAPPED;
 459
 460         spin_lock(&ubi->volumes_lock);
 461         if (vol->ref_count > 1) {
 462                 spin_unlock(&ubi->volumes_lock);
 463                 err = -EBUSY;
 464                 goto out_free;
 465         }
 466         spin_unlock(&ubi->volumes_lock);
 467
 468         /* Reserve physical eraseblocks */
 469         pebs = reserved_pebs - vol->reserved_pebs;
 470         if (pebs > 0) {
 471                 spin_lock(&ubi->volumes_lock);
 472                 if (pebs > ubi->avail_pebs) {
 473                         ubi_err(ubi, "not enough PEBs: requested %d, available %d",
 474                                 pebs, ubi->avail_pebs);
 475                         if (ubi->corr_peb_count)
 476                                 ubi_err(ubi, "%d PEBs are corrupted and not used",
 477                                         ubi->corr_peb_count);
 478                         spin_unlock(&ubi->volumes_lock);
 479                         err = -ENOSPC;
 480                         goto out_free;
 481                 }
 482                 ubi->avail_pebs -= pebs;
 483                 ubi->rsvd_pebs += pebs;
 484                 for (i = 0; i < vol->reserved_pebs; i++)
 485                         new_mapping[i] = vol->eba_tbl[i];
 486                 kfree(vol->eba_tbl);
 487                 vol->eba_tbl = new_mapping;
 488                 spin_unlock(&ubi->volumes_lock);
 489         }
 490
 491         if (pebs < 0) {
 492                 for (i = 0; i < -pebs; i++) {
 493                         err = ubi_eba_unmap_leb(ubi, vol, reserved_pebs + i);
 494                         if (err)
 495                                 goto out_acc;
 496                 }
 497                 spin_lock(&ubi->volumes_lock);
 498                 ubi->rsvd_pebs += pebs;
 499                 ubi->avail_pebs -= pebs;
 500                 ubi_update_reserved(ubi);
 501                 for (i = 0; i < reserved_pebs; i++)
 502                         new_mapping[i] = vol->eba_tbl[i];
 503                 kfree(vol->eba_tbl);
 504                 vol->eba_tbl = new_mapping;
 505                 spin_unlock(&ubi->volumes_lock);
 506         }
 507
 508         /*
 509          * When we shrink a volume we have to flush all pending (erase) work.
 510          * Otherwise it can happen that upon next attach UBI finds a LEB with
 511          * lnum > highest_lnum and refuses to attach.
 512          */
 513         if (pebs < 0) {
 514                 err = ubi_wl_flush(ubi, vol_id, UBI_ALL);
 515                 if (err)
 516                         goto out_acc;
 517         }
 518
 519         /* Change volume table record */
 520         vtbl_rec = ubi->vtbl[vol_id];
 521         vtbl_rec.reserved_pebs = cpu_to_be32(reserved_pebs);
 522         err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
 523         if (err)
 524                 goto out_acc;
 525
 526         vol->reserved_pebs = reserved_pebs;
 527         if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
 528                 vol->used_ebs = reserved_pebs;
 529                 vol->last_eb_bytes = vol->usable_leb_size;
 530                 vol->used_bytes =
 531                         (long long)vol->used_ebs * vol->usable_leb_size;
 532         }
 533
 534         ubi_volume_notify(ubi, vol, UBI_VOLUME_RESIZED);
 535         self_check_volumes(ubi);
 536         return err;
 537
 538 out_acc:
 539         if (pebs > 0) {
 540                 spin_lock(&ubi->volumes_lock);
 541                 ubi->rsvd_pebs -= pebs;
 542                 ubi->avail_pebs += pebs;
 543                 spin_unlock(&ubi->volumes_lock);
 544         }
 545 out_free:
 546         kfree(new_mapping);
 547         return err;
 548 }
 549
 550 /**
 551  * ubi_rename_volumes - re-name UBI volumes.
 552  * @ubi: UBI device description object
 553  * @rename_list: list of &struct ubi_rename_entry objects
 554  *
 555  * This function re-names or removes volumes specified in the re-name list.
 556  * Returns zero in case of success and a negative error code in case of
 557  * failure.
 558  */
 559 int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list)
 560 {
 561         int err;
 562         struct ubi_rename_entry *re;
 563
 564         err = ubi_vtbl_rename_volumes(ubi, rename_list);
 565         if (err)
 566                 return err;
 567
 568         list_for_each_entry(re, rename_list, list) {
 569                 if (re->remove) {
 570                         err = ubi_remove_volume(re->desc, 1);
 571                         if (err)
 572                                 break;
 573                 } else {
 574                         struct ubi_volume *vol = re->desc->vol;
 575
 576                         spin_lock(&ubi->volumes_lock);
 577                         vol->name_len = re->new_name_len;
 578                         memcpy(vol->name, re->new_name, re->new_name_len + 1);
 579                         spin_unlock(&ubi->volumes_lock);
 580                         ubi_volume_notify(ubi, vol, UBI_VOLUME_RENAMED);
 581                 }
 582         }
 583
 584         if (!err)
 585                 self_check_volumes(ubi);
 586         return err;
 587 }
 588
 589 /**
 590  * ubi_add_volume - add volume.
 591  * @ubi: UBI device description object
 592  * @vol: volume description object
 593  *
 594  * This function adds an existing volume and initializes all its data
 595  * structures. Returns zero in case of success and a negative error code in
 596  * case of failure.
 597  */
 598 int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol)
 599 {
 600         int err, vol_id = vol->vol_id;
 601         dev_t dev;
 602
 603         dbg_gen("add volume %d", vol_id);
 604
 605         /* Register character device for the volume */
 606         cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
 607         vol->cdev.owner = THIS_MODULE;
 608         dev = MKDEV(MAJOR(ubi->cdev.dev), vol->vol_id + 1);
 609         err = cdev_add(&vol->cdev, dev, 1);
 610         if (err) {
 611                 ubi_err(ubi, "cannot add character device for volume %d, error %d",
 612                         vol_id, err);
 613                 return err;
 614         }
 615
 616         vol->dev.release = vol_release;
 617         vol->dev.parent = &ubi->dev;
 618         vol->dev.devt = dev;
 619         vol->dev.class = &ubi_class;
 620         vol->dev.groups = volume_dev_groups;
 621         dev_set_name(&vol->dev, "%s_%d", ubi->ubi_name, vol->vol_id);
 622         err = device_register(&vol->dev);
 623         if (err)
 624                 goto out_cdev;
 625
 626         self_check_volumes(ubi);
 627         return err;
 628
 629 out_cdev:
 630         cdev_del(&vol->cdev);
 631         return err;
 632 }
 633
 634 /**
 635  * ubi_free_volume - free volume.
 636  * @ubi: UBI device description object
 637  * @vol: volume description object
 638  *
 639  * This function frees all resources for volume @vol but does not remove it.
 640  * Used only when the UBI device is detached.
 641  */
 642 void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol)
 643 {
 644         dbg_gen("free volume %d", vol->vol_id);
 645
 646         ubi->volumes[vol->vol_id] = NULL;
 647         cdev_del(&vol->cdev);
 648         device_unregister(&vol->dev);
 649 }
 650
 651 /**
 652  * self_check_volume - check volume information.
 653  * @ubi: UBI device description object
 654  * @vol_id: volume ID
 655  *
 656  * Returns zero if volume is all right and a a negative error code if not.
 657  */
 658 static int self_check_volume(struct ubi_device *ubi, int vol_id)
 659 {
 660         int idx = vol_id2idx(ubi, vol_id);
 661         int reserved_pebs, alignment, data_pad, vol_type, name_len, upd_marker;
 662         const struct ubi_volume *vol;
 663         long long n;
 664         const char *name;
 665
 666         spin_lock(&ubi->volumes_lock);
 667         reserved_pebs = be32_to_cpu(ubi->vtbl[vol_id].reserved_pebs);
 668         vol = ubi->volumes[idx];
 669
 670         if (!vol) {
 671                 if (reserved_pebs) {
 672                         ubi_err(ubi, "no volume info, but volume exists");
 673                         goto fail;
 674                 }
 675                 spin_unlock(&ubi->volumes_lock);
 676                 return 0;
 677         }
 678
 679         if (vol->reserved_pebs < 0 || vol->alignment < 0 || vol->data_pad < 0 ||
 680             vol->name_len < 0) {
 681                 ubi_err(ubi, "negative values");
 682                 goto fail;
 683         }
 684         if (vol->alignment > ubi->leb_size || vol->alignment == 0) {
 685                 ubi_err(ubi, "bad alignment");
 686                 goto fail;
 687         }
 688
 689         n = vol->alignment & (ubi->min_io_size - 1);
 690         if (vol->alignment != 1 && n) {
 691                 ubi_err(ubi, "alignment is not multiple of min I/O unit");
 692                 goto fail;
 693         }
 694
 695         n = ubi->leb_size % vol->alignment;
 696         if (vol->data_pad != n) {
 697                 ubi_err(ubi, "bad data_pad, has to be %lld", n);
 698                 goto fail;
 699         }
 700
 701         if (vol->vol_type != UBI_DYNAMIC_VOLUME &&
 702             vol->vol_type != UBI_STATIC_VOLUME) {
 703                 ubi_err(ubi, "bad vol_type");
 704                 goto fail;
 705         }
 706
 707         if (vol->upd_marker && vol->corrupted) {
 708                 ubi_err(ubi, "update marker and corrupted simultaneously");
 709                 goto fail;
 710         }
 711
 712         if (vol->reserved_pebs > ubi->good_peb_count) {
 713                 ubi_err(ubi, "too large reserved_pebs");
 714                 goto fail;
 715         }
 716
 717         n = ubi->leb_size - vol->data_pad;
 718         if (vol->usable_leb_size != ubi->leb_size - vol->data_pad) {
 719                 ubi_err(ubi, "bad usable_leb_size, has to be %lld", n);
 720                 goto fail;
 721         }
 722
 723         if (vol->name_len > UBI_VOL_NAME_MAX) {
 724                 ubi_err(ubi, "too long volume name, max is %d",
 725                         UBI_VOL_NAME_MAX);
 726                 goto fail;
 727         }
 728
 729         n = strnlen(vol->name, vol->name_len + 1);
 730         if (n != vol->name_len) {
 731                 ubi_err(ubi, "bad name_len %lld", n);
 732                 goto fail;
 733         }
 734
 735         n = (long long)vol->used_ebs * vol->usable_leb_size;
 736         if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
 737                 if (vol->corrupted) {
 738                         ubi_err(ubi, "corrupted dynamic volume");
 739                         goto fail;
 740                 }
 741                 if (vol->used_ebs != vol->reserved_pebs) {
 742                         ubi_err(ubi, "bad used_ebs");
 743                         goto fail;
 744                 }
 745                 if (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 != n) {
 750                         ubi_err(ubi, "bad used_bytes");
 751                         goto fail;
 752                 }
 753         } else {
 754                 if (vol->used_ebs < 0 || vol->used_ebs > vol->reserved_pebs) {
 755                         ubi_err(ubi, "bad used_ebs");
 756                         goto fail;
 757                 }
 758                 if (vol->last_eb_bytes < 0 ||
 759                     vol->last_eb_bytes > vol->usable_leb_size) {
 760                         ubi_err(ubi, "bad last_eb_bytes");
 761                         goto fail;
 762                 }
 763                 if (vol->used_bytes < 0 || vol->used_bytes > n ||
 764                     vol->used_bytes < n - vol->usable_leb_size) {
 765                         ubi_err(ubi, "bad used_bytes");
 766                         goto fail;
 767                 }
 768         }
 769
 770         alignment  = be32_to_cpu(ubi->vtbl[vol_id].alignment);
 771         data_pad   = be32_to_cpu(ubi->vtbl[vol_id].data_pad);
 772         name_len   = be16_to_cpu(ubi->vtbl[vol_id].name_len);
 773         upd_marker = ubi->vtbl[vol_id].upd_marker;
 774         name       = &ubi->vtbl[vol_id].name[0];
 775         if (ubi->vtbl[vol_id].vol_type == UBI_VID_DYNAMIC)
 776                 vol_type = UBI_DYNAMIC_VOLUME;
 777         else
 778                 vol_type = UBI_STATIC_VOLUME;
 779
 780         if (alignment != vol->alignment || data_pad != vol->data_pad ||
 781             upd_marker != vol->upd_marker || vol_type != vol->vol_type ||
 782             name_len != vol->name_len || strncmp(name, vol->name, name_len)) {
 783                 ubi_err(ubi, "volume info is different");
 784                 goto fail;
 785         }
 786
 787         spin_unlock(&ubi->volumes_lock);
 788         return 0;
 789
 790 fail:
 791         ubi_err(ubi, "self-check failed for volume %d", vol_id);
 792         if (vol)
 793                 ubi_dump_vol_info(vol);
 794         ubi_dump_vtbl_record(&ubi->vtbl[vol_id], vol_id);
 795         dump_stack();
 796         spin_unlock(&ubi->volumes_lock);
 797         return -EINVAL;
 798 }
 799
 800 /**
 801  * self_check_volumes - check information about all volumes.
 802  * @ubi: UBI device description object
 803  *
 804  * Returns zero if volumes are all right and a a negative error code if not.
 805  */
 806 static int self_check_volumes(struct ubi_device *ubi)
 807 {
 808         int i, err = 0;
 809
 810         if (!ubi_dbg_chk_gen(ubi))
 811                 return 0;
 812
 813         for (i = 0; i < ubi->vtbl_slots; i++) {
 814                 err = self_check_volume(ubi, i);
 815                 if (err)
 816                         break;
 817         }
 818
 819         return err;
 820 }