linux/drivers/mtd/ubi/cdev.c
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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 includes implementation of UBI character device operations.
  10 *
  11 * There are two kinds of character devices in UBI: UBI character devices and
  12 * UBI volume character devices. UBI character devices allow users to
  13 * manipulate whole volumes: create, remove, and re-size them. Volume character
  14 * devices provide volume I/O capabilities.
  15 *
  16 * Major and minor numbers are assigned dynamically to both UBI and volume
  17 * character devices.
  18 *
  19 * Well, there is the third kind of character devices - the UBI control
  20 * character device, which allows to manipulate by UBI devices - create and
  21 * delete them. In other words, it is used for attaching and detaching MTD
  22 * devices.
  23 */
  24
  25#include <linux/module.h>
  26#include <linux/stat.h>
  27#include <linux/slab.h>
  28#include <linux/ioctl.h>
  29#include <linux/capability.h>
  30#include <linux/uaccess.h>
  31#include <linux/compat.h>
  32#include <linux/math64.h>
  33#include <mtd/ubi-user.h>
  34#include "ubi.h"
  35
  36/**
  37 * get_exclusive - get exclusive access to an UBI volume.
  38 * @desc: volume descriptor
  39 *
  40 * This function changes UBI volume open mode to "exclusive". Returns previous
  41 * mode value (positive integer) in case of success and a negative error code
  42 * in case of failure.
  43 */
  44static int get_exclusive(struct ubi_volume_desc *desc)
  45{
  46        int users, err;
  47        struct ubi_volume *vol = desc->vol;
  48
  49        spin_lock(&vol->ubi->volumes_lock);
  50        users = vol->readers + vol->writers + vol->exclusive + vol->metaonly;
  51        ubi_assert(users > 0);
  52        if (users > 1) {
  53                ubi_err(vol->ubi, "%d users for volume %d", users, vol->vol_id);
  54                err = -EBUSY;
  55        } else {
  56                vol->readers = vol->writers = vol->metaonly = 0;
  57                vol->exclusive = 1;
  58                err = desc->mode;
  59                desc->mode = UBI_EXCLUSIVE;
  60        }
  61        spin_unlock(&vol->ubi->volumes_lock);
  62
  63        return err;
  64}
  65
  66/**
  67 * revoke_exclusive - revoke exclusive mode.
  68 * @desc: volume descriptor
  69 * @mode: new mode to switch to
  70 */
  71static void revoke_exclusive(struct ubi_volume_desc *desc, int mode)
  72{
  73        struct ubi_volume *vol = desc->vol;
  74
  75        spin_lock(&vol->ubi->volumes_lock);
  76        ubi_assert(vol->readers == 0 && vol->writers == 0 && vol->metaonly == 0);
  77        ubi_assert(vol->exclusive == 1 && desc->mode == UBI_EXCLUSIVE);
  78        vol->exclusive = 0;
  79        if (mode == UBI_READONLY)
  80                vol->readers = 1;
  81        else if (mode == UBI_READWRITE)
  82                vol->writers = 1;
  83        else if (mode == UBI_METAONLY)
  84                vol->metaonly = 1;
  85        else
  86                vol->exclusive = 1;
  87        spin_unlock(&vol->ubi->volumes_lock);
  88
  89        desc->mode = mode;
  90}
  91
  92static int vol_cdev_open(struct inode *inode, struct file *file)
  93{
  94        struct ubi_volume_desc *desc;
  95        int vol_id = iminor(inode) - 1, mode, ubi_num;
  96
  97        ubi_num = ubi_major2num(imajor(inode));
  98        if (ubi_num < 0)
  99                return ubi_num;
 100
 101        if (file->f_mode & FMODE_WRITE)
 102                mode = UBI_READWRITE;
 103        else
 104                mode = UBI_READONLY;
 105
 106        dbg_gen("open device %d, volume %d, mode %d",
 107                ubi_num, vol_id, mode);
 108
 109        desc = ubi_open_volume(ubi_num, vol_id, mode);
 110        if (IS_ERR(desc))
 111                return PTR_ERR(desc);
 112
 113        file->private_data = desc;
 114        return 0;
 115}
 116
 117static int vol_cdev_release(struct inode *inode, struct file *file)
 118{
 119        struct ubi_volume_desc *desc = file->private_data;
 120        struct ubi_volume *vol = desc->vol;
 121
 122        dbg_gen("release device %d, volume %d, mode %d",
 123                vol->ubi->ubi_num, vol->vol_id, desc->mode);
 124
 125        if (vol->updating) {
 126                ubi_warn(vol->ubi, "update of volume %d not finished, volume is damaged",
 127                         vol->vol_id);
 128                ubi_assert(!vol->changing_leb);
 129                vol->updating = 0;
 130                vfree(vol->upd_buf);
 131        } else if (vol->changing_leb) {
 132                dbg_gen("only %lld of %lld bytes received for atomic LEB change for volume %d:%d, cancel",
 133                        vol->upd_received, vol->upd_bytes, vol->ubi->ubi_num,
 134                        vol->vol_id);
 135                vol->changing_leb = 0;
 136                vfree(vol->upd_buf);
 137        }
 138
 139        ubi_close_volume(desc);
 140        return 0;
 141}
 142
 143static loff_t vol_cdev_llseek(struct file *file, loff_t offset, int origin)
 144{
 145        struct ubi_volume_desc *desc = file->private_data;
 146        struct ubi_volume *vol = desc->vol;
 147
 148        if (vol->updating) {
 149                /* Update is in progress, seeking is prohibited */
 150                ubi_err(vol->ubi, "updating");
 151                return -EBUSY;
 152        }
 153
 154        return fixed_size_llseek(file, offset, origin, vol->used_bytes);
 155}
 156
 157static int vol_cdev_fsync(struct file *file, loff_t start, loff_t end,
 158                          int datasync)
 159{
 160        struct ubi_volume_desc *desc = file->private_data;
 161        struct ubi_device *ubi = desc->vol->ubi;
 162        struct inode *inode = file_inode(file);
 163        int err;
 164        inode_lock(inode);
 165        err = ubi_sync(ubi->ubi_num);
 166        inode_unlock(inode);
 167        return err;
 168}
 169
 170
 171static ssize_t vol_cdev_read(struct file *file, __user char *buf, size_t count,
 172                             loff_t *offp)
 173{
 174        struct ubi_volume_desc *desc = file->private_data;
 175        struct ubi_volume *vol = desc->vol;
 176        struct ubi_device *ubi = vol->ubi;
 177        int err, lnum, off, len,  tbuf_size;
 178        size_t count_save = count;
 179        void *tbuf;
 180
 181        dbg_gen("read %zd bytes from offset %lld of volume %d",
 182                count, *offp, vol->vol_id);
 183
 184        if (vol->updating) {
 185                ubi_err(vol->ubi, "updating");
 186                return -EBUSY;
 187        }
 188        if (vol->upd_marker) {
 189                ubi_err(vol->ubi, "damaged volume, update marker is set");
 190                return -EBADF;
 191        }
 192        if (*offp == vol->used_bytes || count == 0)
 193                return 0;
 194
 195        if (vol->corrupted)
 196                dbg_gen("read from corrupted volume %d", vol->vol_id);
 197
 198        if (*offp + count > vol->used_bytes)
 199                count_save = count = vol->used_bytes - *offp;
 200
 201        tbuf_size = vol->usable_leb_size;
 202        if (count < tbuf_size)
 203                tbuf_size = ALIGN(count, ubi->min_io_size);
 204        tbuf = vmalloc(tbuf_size);
 205        if (!tbuf)
 206                return -ENOMEM;
 207
 208        len = count > tbuf_size ? tbuf_size : count;
 209        lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
 210
 211        do {
 212                cond_resched();
 213
 214                if (off + len >= vol->usable_leb_size)
 215                        len = vol->usable_leb_size - off;
 216
 217                err = ubi_eba_read_leb(ubi, vol, lnum, tbuf, off, len, 0);
 218                if (err)
 219                        break;
 220
 221                off += len;
 222                if (off == vol->usable_leb_size) {
 223                        lnum += 1;
 224                        off -= vol->usable_leb_size;
 225                }
 226
 227                count -= len;
 228                *offp += len;
 229
 230                err = copy_to_user(buf, tbuf, len);
 231                if (err) {
 232                        err = -EFAULT;
 233                        break;
 234                }
 235
 236                buf += len;
 237                len = count > tbuf_size ? tbuf_size : count;
 238        } while (count);
 239
 240        vfree(tbuf);
 241        return err ? err : count_save - count;
 242}
 243
 244/*
 245 * This function allows to directly write to dynamic UBI volumes, without
 246 * issuing the volume update operation.
 247 */
 248static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
 249                                     size_t count, loff_t *offp)
 250{
 251        struct ubi_volume_desc *desc = file->private_data;
 252        struct ubi_volume *vol = desc->vol;
 253        struct ubi_device *ubi = vol->ubi;
 254        int lnum, off, len, tbuf_size, err = 0;
 255        size_t count_save = count;
 256        char *tbuf;
 257
 258        if (!vol->direct_writes)
 259                return -EPERM;
 260
 261        dbg_gen("requested: write %zd bytes to offset %lld of volume %u",
 262                count, *offp, vol->vol_id);
 263
 264        if (vol->vol_type == UBI_STATIC_VOLUME)
 265                return -EROFS;
 266
 267        lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
 268        if (off & (ubi->min_io_size - 1)) {
 269                ubi_err(ubi, "unaligned position");
 270                return -EINVAL;
 271        }
 272
 273        if (*offp + count > vol->used_bytes)
 274                count_save = count = vol->used_bytes - *offp;
 275
 276        /* We can write only in fractions of the minimum I/O unit */
 277        if (count & (ubi->min_io_size - 1)) {
 278                ubi_err(ubi, "unaligned write length");
 279                return -EINVAL;
 280        }
 281
 282        tbuf_size = vol->usable_leb_size;
 283        if (count < tbuf_size)
 284                tbuf_size = ALIGN(count, ubi->min_io_size);
 285        tbuf = vmalloc(tbuf_size);
 286        if (!tbuf)
 287                return -ENOMEM;
 288
 289        len = count > tbuf_size ? tbuf_size : count;
 290
 291        while (count) {
 292                cond_resched();
 293
 294                if (off + len >= vol->usable_leb_size)
 295                        len = vol->usable_leb_size - off;
 296
 297                err = copy_from_user(tbuf, buf, len);
 298                if (err) {
 299                        err = -EFAULT;
 300                        break;
 301                }
 302
 303                err = ubi_eba_write_leb(ubi, vol, lnum, tbuf, off, len);
 304                if (err)
 305                        break;
 306
 307                off += len;
 308                if (off == vol->usable_leb_size) {
 309                        lnum += 1;
 310                        off -= vol->usable_leb_size;
 311                }
 312
 313                count -= len;
 314                *offp += len;
 315                buf += len;
 316                len = count > tbuf_size ? tbuf_size : count;
 317        }
 318
 319        vfree(tbuf);
 320        return err ? err : count_save - count;
 321}
 322
 323static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
 324                              size_t count, loff_t *offp)
 325{
 326        int err = 0;
 327        struct ubi_volume_desc *desc = file->private_data;
 328        struct ubi_volume *vol = desc->vol;
 329        struct ubi_device *ubi = vol->ubi;
 330
 331        if (!vol->updating && !vol->changing_leb)
 332                return vol_cdev_direct_write(file, buf, count, offp);
 333
 334        if (vol->updating)
 335                err = ubi_more_update_data(ubi, vol, buf, count);
 336        else
 337                err = ubi_more_leb_change_data(ubi, vol, buf, count);
 338
 339        if (err < 0) {
 340                ubi_err(ubi, "cannot accept more %zd bytes of data, error %d",
 341                        count, err);
 342                return err;
 343        }
 344
 345        if (err) {
 346                /*
 347                 * The operation is finished, @err contains number of actually
 348                 * written bytes.
 349                 */
 350                count = err;
 351
 352                if (vol->changing_leb) {
 353                        revoke_exclusive(desc, UBI_READWRITE);
 354                        return count;
 355                }
 356
 357                /*
 358                 * We voluntarily do not take into account the skip_check flag
 359                 * as we want to make sure what we wrote was correctly written.
 360                 */
 361                err = ubi_check_volume(ubi, vol->vol_id);
 362                if (err < 0)
 363                        return err;
 364
 365                if (err) {
 366                        ubi_warn(ubi, "volume %d on UBI device %d is corrupted",
 367                                 vol->vol_id, ubi->ubi_num);
 368                        vol->corrupted = 1;
 369                }
 370                vol->checked = 1;
 371                ubi_volume_notify(ubi, vol, UBI_VOLUME_UPDATED);
 372                revoke_exclusive(desc, UBI_READWRITE);
 373        }
 374
 375        return count;
 376}
 377
 378static long vol_cdev_ioctl(struct file *file, unsigned int cmd,
 379                           unsigned long arg)
 380{
 381        int err = 0;
 382        struct ubi_volume_desc *desc = file->private_data;
 383        struct ubi_volume *vol = desc->vol;
 384        struct ubi_device *ubi = vol->ubi;
 385        void __user *argp = (void __user *)arg;
 386
 387        switch (cmd) {
 388        /* Volume update command */
 389        case UBI_IOCVOLUP:
 390        {
 391                int64_t bytes, rsvd_bytes;
 392
 393                if (!capable(CAP_SYS_RESOURCE)) {
 394                        err = -EPERM;
 395                        break;
 396                }
 397
 398                err = copy_from_user(&bytes, argp, sizeof(int64_t));
 399                if (err) {
 400                        err = -EFAULT;
 401                        break;
 402                }
 403
 404                if (desc->mode == UBI_READONLY) {
 405                        err = -EROFS;
 406                        break;
 407                }
 408
 409                rsvd_bytes = (long long)vol->reserved_pebs *
 410                                        vol->usable_leb_size;
 411                if (bytes < 0 || bytes > rsvd_bytes) {
 412                        err = -EINVAL;
 413                        break;
 414                }
 415
 416                err = get_exclusive(desc);
 417                if (err < 0)
 418                        break;
 419
 420                err = ubi_start_update(ubi, vol, bytes);
 421                if (bytes == 0) {
 422                        ubi_volume_notify(ubi, vol, UBI_VOLUME_UPDATED);
 423                        revoke_exclusive(desc, UBI_READWRITE);
 424                }
 425                break;
 426        }
 427
 428        /* Atomic logical eraseblock change command */
 429        case UBI_IOCEBCH:
 430        {
 431                struct ubi_leb_change_req req;
 432
 433                err = copy_from_user(&req, argp,
 434                                     sizeof(struct ubi_leb_change_req));
 435                if (err) {
 436                        err = -EFAULT;
 437                        break;
 438                }
 439
 440                if (desc->mode == UBI_READONLY ||
 441                    vol->vol_type == UBI_STATIC_VOLUME) {
 442                        err = -EROFS;
 443                        break;
 444                }
 445
 446                /* Validate the request */
 447                err = -EINVAL;
 448                if (!ubi_leb_valid(vol, req.lnum) ||
 449                    req.bytes < 0 || req.bytes > vol->usable_leb_size)
 450                        break;
 451
 452                err = get_exclusive(desc);
 453                if (err < 0)
 454                        break;
 455
 456                err = ubi_start_leb_change(ubi, vol, &req);
 457                if (req.bytes == 0)
 458                        revoke_exclusive(desc, UBI_READWRITE);
 459                break;
 460        }
 461
 462        /* Logical eraseblock erasure command */
 463        case UBI_IOCEBER:
 464        {
 465                int32_t lnum;
 466
 467                err = get_user(lnum, (__user int32_t *)argp);
 468                if (err) {
 469                        err = -EFAULT;
 470                        break;
 471                }
 472
 473                if (desc->mode == UBI_READONLY ||
 474                    vol->vol_type == UBI_STATIC_VOLUME) {
 475                        err = -EROFS;
 476                        break;
 477                }
 478
 479                if (!ubi_leb_valid(vol, lnum)) {
 480                        err = -EINVAL;
 481                        break;
 482                }
 483
 484                dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
 485                err = ubi_eba_unmap_leb(ubi, vol, lnum);
 486                if (err)
 487                        break;
 488
 489                err = ubi_wl_flush(ubi, UBI_ALL, UBI_ALL);
 490                break;
 491        }
 492
 493        /* Logical eraseblock map command */
 494        case UBI_IOCEBMAP:
 495        {
 496                struct ubi_map_req req;
 497
 498                err = copy_from_user(&req, argp, sizeof(struct ubi_map_req));
 499                if (err) {
 500                        err = -EFAULT;
 501                        break;
 502                }
 503                err = ubi_leb_map(desc, req.lnum);
 504                break;
 505        }
 506
 507        /* Logical eraseblock un-map command */
 508        case UBI_IOCEBUNMAP:
 509        {
 510                int32_t lnum;
 511
 512                err = get_user(lnum, (__user int32_t *)argp);
 513                if (err) {
 514                        err = -EFAULT;
 515                        break;
 516                }
 517                err = ubi_leb_unmap(desc, lnum);
 518                break;
 519        }
 520
 521        /* Check if logical eraseblock is mapped command */
 522        case UBI_IOCEBISMAP:
 523        {
 524                int32_t lnum;
 525
 526                err = get_user(lnum, (__user int32_t *)argp);
 527                if (err) {
 528                        err = -EFAULT;
 529                        break;
 530                }
 531                err = ubi_is_mapped(desc, lnum);
 532                break;
 533        }
 534
 535        /* Set volume property command */
 536        case UBI_IOCSETVOLPROP:
 537        {
 538                struct ubi_set_vol_prop_req req;
 539
 540                err = copy_from_user(&req, argp,
 541                                     sizeof(struct ubi_set_vol_prop_req));
 542                if (err) {
 543                        err = -EFAULT;
 544                        break;
 545                }
 546                switch (req.property) {
 547                case UBI_VOL_PROP_DIRECT_WRITE:
 548                        mutex_lock(&ubi->device_mutex);
 549                        desc->vol->direct_writes = !!req.value;
 550                        mutex_unlock(&ubi->device_mutex);
 551                        break;
 552                default:
 553                        err = -EINVAL;
 554                        break;
 555                }
 556                break;
 557        }
 558
 559        /* Create a R/O block device on top of the UBI volume */
 560        case UBI_IOCVOLCRBLK:
 561        {
 562                struct ubi_volume_info vi;
 563
 564                ubi_get_volume_info(desc, &vi);
 565                err = ubiblock_create(&vi);
 566                break;
 567        }
 568
 569        /* Remove the R/O block device */
 570        case UBI_IOCVOLRMBLK:
 571        {
 572                struct ubi_volume_info vi;
 573
 574                ubi_get_volume_info(desc, &vi);
 575                err = ubiblock_remove(&vi);
 576                break;
 577        }
 578
 579        default:
 580                err = -ENOTTY;
 581                break;
 582        }
 583        return err;
 584}
 585
 586/**
 587 * verify_mkvol_req - verify volume creation request.
 588 * @ubi: UBI device description object
 589 * @req: the request to check
 590 *
 591 * This function zero if the request is correct, and %-EINVAL if not.
 592 */
 593static int verify_mkvol_req(const struct ubi_device *ubi,
 594                            const struct ubi_mkvol_req *req)
 595{
 596        int n, err = -EINVAL;
 597
 598        if (req->bytes < 0 || req->alignment < 0 || req->vol_type < 0 ||
 599            req->name_len < 0)
 600                goto bad;
 601
 602        if ((req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) &&
 603            req->vol_id != UBI_VOL_NUM_AUTO)
 604                goto bad;
 605
 606        if (req->alignment == 0)
 607                goto bad;
 608
 609        if (req->bytes == 0)
 610                goto bad;
 611
 612        if (req->vol_type != UBI_DYNAMIC_VOLUME &&
 613            req->vol_type != UBI_STATIC_VOLUME)
 614                goto bad;
 615
 616        if (req->flags & ~UBI_VOL_VALID_FLGS)
 617                goto bad;
 618
 619        if (req->flags & UBI_VOL_SKIP_CRC_CHECK_FLG &&
 620            req->vol_type != UBI_STATIC_VOLUME)
 621                goto bad;
 622
 623        if (req->alignment > ubi->leb_size)
 624                goto bad;
 625
 626        n = req->alignment & (ubi->min_io_size - 1);
 627        if (req->alignment != 1 && n)
 628                goto bad;
 629
 630        if (!req->name[0] || !req->name_len)
 631                goto bad;
 632
 633        if (req->name_len > UBI_VOL_NAME_MAX) {
 634                err = -ENAMETOOLONG;
 635                goto bad;
 636        }
 637
 638        n = strnlen(req->name, req->name_len + 1);
 639        if (n != req->name_len)
 640                goto bad;
 641
 642        return 0;
 643
 644bad:
 645        ubi_err(ubi, "bad volume creation request");
 646        ubi_dump_mkvol_req(req);
 647        return err;
 648}
 649
 650/**
 651 * verify_rsvol_req - verify volume re-size request.
 652 * @ubi: UBI device description object
 653 * @req: the request to check
 654 *
 655 * This function returns zero if the request is correct, and %-EINVAL if not.
 656 */
 657static int verify_rsvol_req(const struct ubi_device *ubi,
 658                            const struct ubi_rsvol_req *req)
 659{
 660        if (req->bytes <= 0)
 661                return -EINVAL;
 662
 663        if (req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots)
 664                return -EINVAL;
 665
 666        return 0;
 667}
 668
 669/**
 670 * rename_volumes - rename UBI volumes.
 671 * @ubi: UBI device description object
 672 * @req: volumes re-name request
 673 *
 674 * This is a helper function for the volume re-name IOCTL which validates the
 675 * the request, opens the volume and calls corresponding volumes management
 676 * function. Returns zero in case of success and a negative error code in case
 677 * of failure.
 678 */
 679static int rename_volumes(struct ubi_device *ubi,
 680                          struct ubi_rnvol_req *req)
 681{
 682        int i, n, err;
 683        struct list_head rename_list;
 684        struct ubi_rename_entry *re, *re1;
 685
 686        if (req->count < 0 || req->count > UBI_MAX_RNVOL)
 687                return -EINVAL;
 688
 689        if (req->count == 0)
 690                return 0;
 691
 692        /* Validate volume IDs and names in the request */
 693        for (i = 0; i < req->count; i++) {
 694                if (req->ents[i].vol_id < 0 ||
 695                    req->ents[i].vol_id >= ubi->vtbl_slots)
 696                        return -EINVAL;
 697                if (req->ents[i].name_len < 0)
 698                        return -EINVAL;
 699                if (req->ents[i].name_len > UBI_VOL_NAME_MAX)
 700                        return -ENAMETOOLONG;
 701                req->ents[i].name[req->ents[i].name_len] = '\0';
 702                n = strlen(req->ents[i].name);
 703                if (n != req->ents[i].name_len)
 704                        return -EINVAL;
 705        }
 706
 707        /* Make sure volume IDs and names are unique */
 708        for (i = 0; i < req->count - 1; i++) {
 709                for (n = i + 1; n < req->count; n++) {
 710                        if (req->ents[i].vol_id == req->ents[n].vol_id) {
 711                                ubi_err(ubi, "duplicated volume id %d",
 712                                        req->ents[i].vol_id);
 713                                return -EINVAL;
 714                        }
 715                        if (!strcmp(req->ents[i].name, req->ents[n].name)) {
 716                                ubi_err(ubi, "duplicated volume name \"%s\"",
 717                                        req->ents[i].name);
 718                                return -EINVAL;
 719                        }
 720                }
 721        }
 722
 723        /* Create the re-name list */
 724        INIT_LIST_HEAD(&rename_list);
 725        for (i = 0; i < req->count; i++) {
 726                int vol_id = req->ents[i].vol_id;
 727                int name_len = req->ents[i].name_len;
 728                const char *name = req->ents[i].name;
 729
 730                re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
 731                if (!re) {
 732                        err = -ENOMEM;
 733                        goto out_free;
 734                }
 735
 736                re->desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_METAONLY);
 737                if (IS_ERR(re->desc)) {
 738                        err = PTR_ERR(re->desc);
 739                        ubi_err(ubi, "cannot open volume %d, error %d",
 740                                vol_id, err);
 741                        kfree(re);
 742                        goto out_free;
 743                }
 744
 745                /* Skip this re-naming if the name does not really change */
 746                if (re->desc->vol->name_len == name_len &&
 747                    !memcmp(re->desc->vol->name, name, name_len)) {
 748                        ubi_close_volume(re->desc);
 749                        kfree(re);
 750                        continue;
 751                }
 752
 753                re->new_name_len = name_len;
 754                memcpy(re->new_name, name, name_len);
 755                list_add_tail(&re->list, &rename_list);
 756                dbg_gen("will rename volume %d from \"%s\" to \"%s\"",
 757                        vol_id, re->desc->vol->name, name);
 758        }
 759
 760        if (list_empty(&rename_list))
 761                return 0;
 762
 763        /* Find out the volumes which have to be removed */
 764        list_for_each_entry(re, &rename_list, list) {
 765                struct ubi_volume_desc *desc;
 766                int no_remove_needed = 0;
 767
 768                /*
 769                 * Volume @re->vol_id is going to be re-named to
 770                 * @re->new_name, while its current name is @name. If a volume
 771                 * with name @re->new_name currently exists, it has to be
 772                 * removed, unless it is also re-named in the request (@req).
 773                 */
 774                list_for_each_entry(re1, &rename_list, list) {
 775                        if (re->new_name_len == re1->desc->vol->name_len &&
 776                            !memcmp(re->new_name, re1->desc->vol->name,
 777                                    re1->desc->vol->name_len)) {
 778                                no_remove_needed = 1;
 779                                break;
 780                        }
 781                }
 782
 783                if (no_remove_needed)
 784                        continue;
 785
 786                /*
 787                 * It seems we need to remove volume with name @re->new_name,
 788                 * if it exists.
 789                 */
 790                desc = ubi_open_volume_nm(ubi->ubi_num, re->new_name,
 791                                          UBI_EXCLUSIVE);
 792                if (IS_ERR(desc)) {
 793                        err = PTR_ERR(desc);
 794                        if (err == -ENODEV)
 795                                /* Re-naming into a non-existing volume name */
 796                                continue;
 797
 798                        /* The volume exists but busy, or an error occurred */
 799                        ubi_err(ubi, "cannot open volume \"%s\", error %d",
 800                                re->new_name, err);
 801                        goto out_free;
 802                }
 803
 804                re1 = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
 805                if (!re1) {
 806                        err = -ENOMEM;
 807                        ubi_close_volume(desc);
 808                        goto out_free;
 809                }
 810
 811                re1->remove = 1;
 812                re1->desc = desc;
 813                list_add(&re1->list, &rename_list);
 814                dbg_gen("will remove volume %d, name \"%s\"",
 815                        re1->desc->vol->vol_id, re1->desc->vol->name);
 816        }
 817
 818        mutex_lock(&ubi->device_mutex);
 819        err = ubi_rename_volumes(ubi, &rename_list);
 820        mutex_unlock(&ubi->device_mutex);
 821
 822out_free:
 823        list_for_each_entry_safe(re, re1, &rename_list, list) {
 824                ubi_close_volume(re->desc);
 825                list_del(&re->list);
 826                kfree(re);
 827        }
 828        return err;
 829}
 830
 831static long ubi_cdev_ioctl(struct file *file, unsigned int cmd,
 832                           unsigned long arg)
 833{
 834        int err = 0;
 835        struct ubi_device *ubi;
 836        struct ubi_volume_desc *desc;
 837        void __user *argp = (void __user *)arg;
 838
 839        if (!capable(CAP_SYS_RESOURCE))
 840                return -EPERM;
 841
 842        ubi = ubi_get_by_major(imajor(file->f_mapping->host));
 843        if (!ubi)
 844                return -ENODEV;
 845
 846        switch (cmd) {
 847        /* Create volume command */
 848        case UBI_IOCMKVOL:
 849        {
 850                struct ubi_mkvol_req req;
 851
 852                dbg_gen("create volume");
 853                err = copy_from_user(&req, argp, sizeof(struct ubi_mkvol_req));
 854                if (err) {
 855                        err = -EFAULT;
 856                        break;
 857                }
 858
 859                err = verify_mkvol_req(ubi, &req);
 860                if (err)
 861                        break;
 862
 863                mutex_lock(&ubi->device_mutex);
 864                err = ubi_create_volume(ubi, &req);
 865                mutex_unlock(&ubi->device_mutex);
 866                if (err)
 867                        break;
 868
 869                err = put_user(req.vol_id, (__user int32_t *)argp);
 870                if (err)
 871                        err = -EFAULT;
 872
 873                break;
 874        }
 875
 876        /* Remove volume command */
 877        case UBI_IOCRMVOL:
 878        {
 879                int vol_id;
 880
 881                dbg_gen("remove volume");
 882                err = get_user(vol_id, (__user int32_t *)argp);
 883                if (err) {
 884                        err = -EFAULT;
 885                        break;
 886                }
 887
 888                desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
 889                if (IS_ERR(desc)) {
 890                        err = PTR_ERR(desc);
 891                        break;
 892                }
 893
 894                mutex_lock(&ubi->device_mutex);
 895                err = ubi_remove_volume(desc, 0);
 896                mutex_unlock(&ubi->device_mutex);
 897
 898                /*
 899                 * The volume is deleted (unless an error occurred), and the
 900                 * 'struct ubi_volume' object will be freed when
 901                 * 'ubi_close_volume()' will call 'put_device()'.
 902                 */
 903                ubi_close_volume(desc);
 904                break;
 905        }
 906
 907        /* Re-size volume command */
 908        case UBI_IOCRSVOL:
 909        {
 910                int pebs;
 911                struct ubi_rsvol_req req;
 912
 913                dbg_gen("re-size volume");
 914                err = copy_from_user(&req, argp, sizeof(struct ubi_rsvol_req));
 915                if (err) {
 916                        err = -EFAULT;
 917                        break;
 918                }
 919
 920                err = verify_rsvol_req(ubi, &req);
 921                if (err)
 922                        break;
 923
 924                desc = ubi_open_volume(ubi->ubi_num, req.vol_id, UBI_EXCLUSIVE);
 925                if (IS_ERR(desc)) {
 926                        err = PTR_ERR(desc);
 927                        break;
 928                }
 929
 930                pebs = div_u64(req.bytes + desc->vol->usable_leb_size - 1,
 931                               desc->vol->usable_leb_size);
 932
 933                mutex_lock(&ubi->device_mutex);
 934                err = ubi_resize_volume(desc, pebs);
 935                mutex_unlock(&ubi->device_mutex);
 936                ubi_close_volume(desc);
 937                break;
 938        }
 939
 940        /* Re-name volumes command */
 941        case UBI_IOCRNVOL:
 942        {
 943                struct ubi_rnvol_req *req;
 944
 945                dbg_gen("re-name volumes");
 946                req = kmalloc(sizeof(struct ubi_rnvol_req), GFP_KERNEL);
 947                if (!req) {
 948                        err = -ENOMEM;
 949                        break;
 950                }
 951
 952                err = copy_from_user(req, argp, sizeof(struct ubi_rnvol_req));
 953                if (err) {
 954                        err = -EFAULT;
 955                        kfree(req);
 956                        break;
 957                }
 958
 959                err = rename_volumes(ubi, req);
 960                kfree(req);
 961                break;
 962        }
 963
 964        /* Check a specific PEB for bitflips and scrub it if needed */
 965        case UBI_IOCRPEB:
 966        {
 967                int pnum;
 968
 969                err = get_user(pnum, (__user int32_t *)argp);
 970                if (err) {
 971                        err = -EFAULT;
 972                        break;
 973                }
 974
 975                err = ubi_bitflip_check(ubi, pnum, 0);
 976                break;
 977        }
 978
 979        /* Force scrubbing for a specific PEB */
 980        case UBI_IOCSPEB:
 981        {
 982                int pnum;
 983
 984                err = get_user(pnum, (__user int32_t *)argp);
 985                if (err) {
 986                        err = -EFAULT;
 987                        break;
 988                }
 989
 990                err = ubi_bitflip_check(ubi, pnum, 1);
 991                break;
 992        }
 993
 994        default:
 995                err = -ENOTTY;
 996                break;
 997        }
 998
 999        ubi_put_device(ubi);
1000        return err;
1001}
1002
1003static long ctrl_cdev_ioctl(struct file *file, unsigned int cmd,
1004                            unsigned long arg)
1005{
1006        int err = 0;
1007        void __user *argp = (void __user *)arg;
1008
1009        if (!capable(CAP_SYS_RESOURCE))
1010                return -EPERM;
1011
1012        switch (cmd) {
1013        /* Attach an MTD device command */
1014        case UBI_IOCATT:
1015        {
1016                struct ubi_attach_req req;
1017                struct mtd_info *mtd;
1018
1019                dbg_gen("attach MTD device");
1020                err = copy_from_user(&req, argp, sizeof(struct ubi_attach_req));
1021                if (err) {
1022                        err = -EFAULT;
1023                        break;
1024                }
1025
1026                if (req.mtd_num < 0 ||
1027                    (req.ubi_num < 0 && req.ubi_num != UBI_DEV_NUM_AUTO)) {
1028                        err = -EINVAL;
1029                        break;
1030                }
1031
1032                mtd = get_mtd_device(NULL, req.mtd_num);
1033                if (IS_ERR(mtd)) {
1034                        err = PTR_ERR(mtd);
1035                        break;
1036                }
1037
1038                /*
1039                 * Note, further request verification is done by
1040                 * 'ubi_attach_mtd_dev()'.
1041                 */
1042                mutex_lock(&ubi_devices_mutex);
1043                err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset,
1044                                         req.max_beb_per1024);
1045                mutex_unlock(&ubi_devices_mutex);
1046                if (err < 0)
1047                        put_mtd_device(mtd);
1048                else
1049                        /* @err contains UBI device number */
1050                        err = put_user(err, (__user int32_t *)argp);
1051
1052                break;
1053        }
1054
1055        /* Detach an MTD device command */
1056        case UBI_IOCDET:
1057        {
1058                int ubi_num;
1059
1060                dbg_gen("detach MTD device");
1061                err = get_user(ubi_num, (__user int32_t *)argp);
1062                if (err) {
1063                        err = -EFAULT;
1064                        break;
1065                }
1066
1067                mutex_lock(&ubi_devices_mutex);
1068                err = ubi_detach_mtd_dev(ubi_num, 0);
1069                mutex_unlock(&ubi_devices_mutex);
1070                break;
1071        }
1072
1073        default:
1074                err = -ENOTTY;
1075                break;
1076        }
1077
1078        return err;
1079}
1080
1081/* UBI volume character device operations */
1082const struct file_operations ubi_vol_cdev_operations = {
1083        .owner          = THIS_MODULE,
1084        .open           = vol_cdev_open,
1085        .release        = vol_cdev_release,
1086        .llseek         = vol_cdev_llseek,
1087        .read           = vol_cdev_read,
1088        .write          = vol_cdev_write,
1089        .fsync          = vol_cdev_fsync,
1090        .unlocked_ioctl = vol_cdev_ioctl,
1091        .compat_ioctl   = compat_ptr_ioctl,
1092};
1093
1094/* UBI character device operations */
1095const struct file_operations ubi_cdev_operations = {
1096        .owner          = THIS_MODULE,
1097        .llseek         = no_llseek,
1098        .unlocked_ioctl = ubi_cdev_ioctl,
1099        .compat_ioctl   = compat_ptr_ioctl,
1100};
1101
1102/* UBI control character device operations */
1103const struct file_operations ubi_ctrl_cdev_operations = {
1104        .owner          = THIS_MODULE,
1105        .unlocked_ioctl = ctrl_cdev_ioctl,
1106        .compat_ioctl   = compat_ptr_ioctl,
1107        .llseek         = no_llseek,
1108};
1109