drivers/mtd/ubi/cdev.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 includes implementation of UBI character device operations.
  23  *
  24  * There are two kinds of character devices in UBI: UBI character devices and
  25  * UBI volume character devices. UBI character devices allow users to
  26  * manipulate whole volumes: create, remove, and re-size them. Volume character
  27  * devices provide volume I/O capabilities.
  28  *
  29  * Major and minor numbers are assigned dynamically to both UBI and volume
  30  * character devices.
  31  *
  32  * Well, there is the third kind of character devices - the UBI control
  33  * character device, which allows to manipulate by UBI devices - create and
  34  * delete them. In other words, it is used for attaching and detaching MTD
  35  * devices.
  36  */
  37
  38 #include <linux/module.h>
  39 #include <linux/stat.h>
  40 #include <linux/slab.h>
  41 #include <linux/ioctl.h>
  42 #include <linux/capability.h>
  43 #include <linux/uaccess.h>
  44 #include <linux/compat.h>
  45 #include <linux/math64.h>
  46 #include <mtd/ubi-user.h>
  47 #include "ubi.h"
  48
  49 /**
  50  * get_exclusive - get exclusive access to an UBI volume.
  51  * @desc: volume descriptor
  52  *
  53  * This function changes UBI volume open mode to "exclusive". Returns previous
  54  * mode value (positive integer) in case of success and a negative error code
  55  * in case of failure.
  56  */
  57 static int get_exclusive(struct ubi_volume_desc *desc)
  58 {
  59         int users, err;
  60         struct ubi_volume *vol = desc->vol;
  61
  62         spin_lock(&vol->ubi->volumes_lock);
  63         users = vol->readers + vol->writers + vol->exclusive + vol->metaonly;
  64         ubi_assert(users > 0);
  65         if (users > 1) {
  66                 ubi_err(vol->ubi, "%d users for volume %d", users, vol->vol_id);
  67                 err = -EBUSY;
  68         } else {
  69                 vol->readers = vol->writers = vol->metaonly = 0;
  70                 vol->exclusive = 1;
  71                 err = desc->mode;
  72                 desc->mode = UBI_EXCLUSIVE;
  73         }
  74         spin_unlock(&vol->ubi->volumes_lock);
  75
  76         return err;
  77 }
  78
  79 /**
  80  * revoke_exclusive - revoke exclusive mode.
  81  * @desc: volume descriptor
  82  * @mode: new mode to switch to
  83  */
  84 static void revoke_exclusive(struct ubi_volume_desc *desc, int mode)
  85 {
  86         struct ubi_volume *vol = desc->vol;
  87
  88         spin_lock(&vol->ubi->volumes_lock);
  89         ubi_assert(vol->readers == 0 && vol->writers == 0 && vol->metaonly == 0);
  90         ubi_assert(vol->exclusive == 1 && desc->mode == UBI_EXCLUSIVE);
  91         vol->exclusive = 0;
  92         if (mode == UBI_READONLY)
  93                 vol->readers = 1;
  94         else if (mode == UBI_READWRITE)
  95                 vol->writers = 1;
  96         else if (mode == UBI_METAONLY)
  97                 vol->metaonly = 1;
  98         else
  99                 vol->exclusive = 1;
 100         spin_unlock(&vol->ubi->volumes_lock);
 101
 102         desc->mode = mode;
 103 }
 104
 105 static int vol_cdev_open(struct inode *inode, struct file *file)
 106 {
 107         struct ubi_volume_desc *desc;
 108         int vol_id = iminor(inode) - 1, mode, ubi_num;
 109
 110         ubi_num = ubi_major2num(imajor(inode));
 111         if (ubi_num < 0)
 112                 return ubi_num;
 113
 114         if (file->f_mode & FMODE_WRITE)
 115                 mode = UBI_READWRITE;
 116         else
 117                 mode = UBI_READONLY;
 118
 119         dbg_gen("open device %d, volume %d, mode %d",
 120                 ubi_num, vol_id, mode);
 121
 122         desc = ubi_open_volume(ubi_num, vol_id, mode);
 123         if (IS_ERR(desc))
 124                 return PTR_ERR(desc);
 125
 126         file->private_data = desc;
 127         return 0;
 128 }
 129
 130 static int vol_cdev_release(struct inode *inode, struct file *file)
 131 {
 132         struct ubi_volume_desc *desc = file->private_data;
 133         struct ubi_volume *vol = desc->vol;
 134
 135         dbg_gen("release device %d, volume %d, mode %d",
 136                 vol->ubi->ubi_num, vol->vol_id, desc->mode);
 137
 138         if (vol->updating) {
 139                 ubi_warn(vol->ubi, "update of volume %d not finished, volume is damaged",
 140                          vol->vol_id);
 141                 ubi_assert(!vol->changing_leb);
 142                 vol->updating = 0;
 143                 vfree(vol->upd_buf);
 144         } else if (vol->changing_leb) {
 145                 dbg_gen("only %lld of %lld bytes received for atomic LEB change for volume %d:%d, cancel",
 146                         vol->upd_received, vol->upd_bytes, vol->ubi->ubi_num,
 147                         vol->vol_id);
 148                 vol->changing_leb = 0;
 149                 vfree(vol->upd_buf);
 150         }
 151
 152         ubi_close_volume(desc);
 153         return 0;
 154 }
 155
 156 static loff_t vol_cdev_llseek(struct file *file, loff_t offset, int origin)
 157 {
 158         struct ubi_volume_desc *desc = file->private_data;
 159         struct ubi_volume *vol = desc->vol;
 160
 161         if (vol->updating) {
 162                 /* Update is in progress, seeking is prohibited */
 163                 ubi_err(vol->ubi, "updating");
 164                 return -EBUSY;
 165         }
 166
 167         return fixed_size_llseek(file, offset, origin, vol->used_bytes);
 168 }
 169
 170 static int vol_cdev_fsync(struct file *file, loff_t start, loff_t end,
 171                           int datasync)
 172 {
 173         struct ubi_volume_desc *desc = file->private_data;
 174         struct ubi_device *ubi = desc->vol->ubi;
 175         struct inode *inode = file_inode(file);
 176         int err;
 177         inode_lock(inode);
 178         err = ubi_sync(ubi->ubi_num);
 179         inode_unlock(inode);
 180         return err;
 181 }
 182
 183
 184 static ssize_t vol_cdev_read(struct file *file, __user char *buf, size_t count,
 185                              loff_t *offp)
 186 {
 187         struct ubi_volume_desc *desc = file->private_data;
 188         struct ubi_volume *vol = desc->vol;
 189         struct ubi_device *ubi = vol->ubi;
 190         int err, lnum, off, len,  tbuf_size;
 191         size_t count_save = count;
 192         void *tbuf;
 193
 194         dbg_gen("read %zd bytes from offset %lld of volume %d",
 195                 count, *offp, vol->vol_id);
 196
 197         if (vol->updating) {
 198                 ubi_err(vol->ubi, "updating");
 199                 return -EBUSY;
 200         }
 201         if (vol->upd_marker) {
 202                 ubi_err(vol->ubi, "damaged volume, update marker is set");
 203                 return -EBADF;
 204         }
 205         if (*offp == vol->used_bytes || count == 0)
 206                 return 0;
 207
 208         if (vol->corrupted)
 209                 dbg_gen("read from corrupted volume %d", vol->vol_id);
 210
 211         if (*offp + count > vol->used_bytes)
 212                 count_save = count = vol->used_bytes - *offp;
 213
 214         tbuf_size = vol->usable_leb_size;
 215         if (count < tbuf_size)
 216                 tbuf_size = ALIGN(count, ubi->min_io_size);
 217         tbuf = vmalloc(tbuf_size);
 218         if (!tbuf)
 219                 return -ENOMEM;
 220
 221         len = count > tbuf_size ? tbuf_size : count;
 222         lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
 223
 224         do {
 225                 cond_resched();
 226
 227                 if (off + len >= vol->usable_leb_size)
 228                         len = vol->usable_leb_size - off;
 229
 230                 err = ubi_eba_read_leb(ubi, vol, lnum, tbuf, off, len, 0);
 231                 if (err)
 232                         break;
 233
 234                 off += len;
 235                 if (off == vol->usable_leb_size) {
 236                         lnum += 1;
 237                         off -= vol->usable_leb_size;
 238                 }
 239
 240                 count -= len;
 241                 *offp += len;
 242
 243                 err = copy_to_user(buf, tbuf, len);
 244                 if (err) {
 245                         err = -EFAULT;
 246                         break;
 247                 }
 248
 249                 buf += len;
 250                 len = count > tbuf_size ? tbuf_size : count;
 251         } while (count);
 252
 253         vfree(tbuf);
 254         return err ? err : count_save - count;
 255 }
 256
 257 /*
 258  * This function allows to directly write to dynamic UBI volumes, without
 259  * issuing the volume update operation.
 260  */
 261 static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
 262                                      size_t count, loff_t *offp)
 263 {
 264         struct ubi_volume_desc *desc = file->private_data;
 265         struct ubi_volume *vol = desc->vol;
 266         struct ubi_device *ubi = vol->ubi;
 267         int lnum, off, len, tbuf_size, err = 0;
 268         size_t count_save = count;
 269         char *tbuf;
 270
 271         if (!vol->direct_writes)
 272                 return -EPERM;
 273
 274         dbg_gen("requested: write %zd bytes to offset %lld of volume %u",
 275                 count, *offp, vol->vol_id);
 276
 277         if (vol->vol_type == UBI_STATIC_VOLUME)
 278                 return -EROFS;
 279
 280         lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
 281         if (off & (ubi->min_io_size - 1)) {
 282                 ubi_err(ubi, "unaligned position");
 283                 return -EINVAL;
 284         }
 285
 286         if (*offp + count > vol->used_bytes)
 287                 count_save = count = vol->used_bytes - *offp;
 288
 289         /* We can write only in fractions of the minimum I/O unit */
 290         if (count & (ubi->min_io_size - 1)) {
 291                 ubi_err(ubi, "unaligned write length");
 292                 return -EINVAL;
 293         }
 294
 295         tbuf_size = vol->usable_leb_size;
 296         if (count < tbuf_size)
 297                 tbuf_size = ALIGN(count, ubi->min_io_size);
 298         tbuf = vmalloc(tbuf_size);
 299         if (!tbuf)
 300                 return -ENOMEM;
 301
 302         len = count > tbuf_size ? tbuf_size : count;
 303
 304         while (count) {
 305                 cond_resched();
 306
 307                 if (off + len >= vol->usable_leb_size)
 308                         len = vol->usable_leb_size - off;
 309
 310                 err = copy_from_user(tbuf, buf, len);
 311                 if (err) {
 312                         err = -EFAULT;
 313                         break;
 314                 }
 315
 316                 err = ubi_eba_write_leb(ubi, vol, lnum, tbuf, off, len);
 317                 if (err)
 318                         break;
 319
 320                 off += len;
 321                 if (off == vol->usable_leb_size) {
 322                         lnum += 1;
 323                         off -= vol->usable_leb_size;
 324                 }
 325
 326                 count -= len;
 327                 *offp += len;
 328                 buf += len;
 329                 len = count > tbuf_size ? tbuf_size : count;
 330         }
 331
 332         vfree(tbuf);
 333         return err ? err : count_save - count;
 334 }
 335
 336 static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
 337                               size_t count, loff_t *offp)
 338 {
 339         int err = 0;
 340         struct ubi_volume_desc *desc = file->private_data;
 341         struct ubi_volume *vol = desc->vol;
 342         struct ubi_device *ubi = vol->ubi;
 343
 344         if (!vol->updating && !vol->changing_leb)
 345                 return vol_cdev_direct_write(file, buf, count, offp);
 346
 347         if (vol->updating)
 348                 err = ubi_more_update_data(ubi, vol, buf, count);
 349         else
 350                 err = ubi_more_leb_change_data(ubi, vol, buf, count);
 351
 352         if (err < 0) {
 353                 ubi_err(ubi, "cannot accept more %zd bytes of data, error %d",
 354                         count, err);
 355                 return err;
 356         }
 357
 358         if (err) {
 359                 /*
 360                  * The operation is finished, @err contains number of actually
 361                  * written bytes.
 362                  */
 363                 count = err;
 364
 365                 if (vol->changing_leb) {
 366                         revoke_exclusive(desc, UBI_READWRITE);
 367                         return count;
 368                 }
 369
 370                 /*
 371                  * We voluntarily do not take into account the skip_check flag
 372                  * as we want to make sure what we wrote was correctly written.
 373                  */
 374                 err = ubi_check_volume(ubi, vol->vol_id);
 375                 if (err < 0)
 376                         return err;
 377
 378                 if (err) {
 379                         ubi_warn(ubi, "volume %d on UBI device %d is corrupted",
 380                                  vol->vol_id, ubi->ubi_num);
 381                         vol->corrupted = 1;
 382                 }
 383                 vol->checked = 1;
 384                 ubi_volume_notify(ubi, vol, UBI_VOLUME_UPDATED);
 385                 revoke_exclusive(desc, UBI_READWRITE);
 386         }
 387
 388         return count;
 389 }
 390
 391 static long vol_cdev_ioctl(struct file *file, unsigned int cmd,
 392                            unsigned long arg)
 393 {
 394         int err = 0;
 395         struct ubi_volume_desc *desc = file->private_data;
 396         struct ubi_volume *vol = desc->vol;
 397         struct ubi_device *ubi = vol->ubi;
 398         void __user *argp = (void __user *)arg;
 399
 400         switch (cmd) {
 401         /* Volume update command */
 402         case UBI_IOCVOLUP:
 403         {
 404                 int64_t bytes, rsvd_bytes;
 405
 406                 if (!capable(CAP_SYS_RESOURCE)) {
 407                         err = -EPERM;
 408                         break;
 409                 }
 410
 411                 err = copy_from_user(&bytes, argp, sizeof(int64_t));
 412                 if (err) {
 413                         err = -EFAULT;
 414                         break;
 415                 }
 416
 417                 if (desc->mode == UBI_READONLY) {
 418                         err = -EROFS;
 419                         break;
 420                 }
 421
 422                 rsvd_bytes = (long long)vol->reserved_pebs *
 423                                         vol->usable_leb_size;
 424                 if (bytes < 0 || bytes > rsvd_bytes) {
 425                         err = -EINVAL;
 426                         break;
 427                 }
 428
 429                 err = get_exclusive(desc);
 430                 if (err < 0)
 431                         break;
 432
 433                 err = ubi_start_update(ubi, vol, bytes);
 434                 if (bytes == 0) {
 435                         ubi_volume_notify(ubi, vol, UBI_VOLUME_UPDATED);
 436                         revoke_exclusive(desc, UBI_READWRITE);
 437                 }
 438                 break;
 439         }
 440
 441         /* Atomic logical eraseblock change command */
 442         case UBI_IOCEBCH:
 443         {
 444                 struct ubi_leb_change_req req;
 445
 446                 err = copy_from_user(&req, argp,
 447                                      sizeof(struct ubi_leb_change_req));
 448                 if (err) {
 449                         err = -EFAULT;
 450                         break;
 451                 }
 452
 453                 if (desc->mode == UBI_READONLY ||
 454                     vol->vol_type == UBI_STATIC_VOLUME) {
 455                         err = -EROFS;
 456                         break;
 457                 }
 458
 459                 /* Validate the request */
 460                 err = -EINVAL;
 461                 if (!ubi_leb_valid(vol, req.lnum) ||
 462                     req.bytes < 0 || req.bytes > vol->usable_leb_size)
 463                         break;
 464
 465                 err = get_exclusive(desc);
 466                 if (err < 0)
 467                         break;
 468
 469                 err = ubi_start_leb_change(ubi, vol, &req);
 470                 if (req.bytes == 0)
 471                         revoke_exclusive(desc, UBI_READWRITE);
 472                 break;
 473         }
 474
 475         /* Logical eraseblock erasure command */
 476         case UBI_IOCEBER:
 477         {
 478                 int32_t lnum;
 479
 480                 err = get_user(lnum, (__user int32_t *)argp);
 481                 if (err) {
 482                         err = -EFAULT;
 483                         break;
 484                 }
 485
 486                 if (desc->mode == UBI_READONLY ||
 487                     vol->vol_type == UBI_STATIC_VOLUME) {
 488                         err = -EROFS;
 489                         break;
 490                 }
 491
 492                 if (!ubi_leb_valid(vol, lnum)) {
 493                         err = -EINVAL;
 494                         break;
 495                 }
 496
 497                 dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
 498                 err = ubi_eba_unmap_leb(ubi, vol, lnum);
 499                 if (err)
 500                         break;
 501
 502                 err = ubi_wl_flush(ubi, UBI_ALL, UBI_ALL);
 503                 break;
 504         }
 505
 506         /* Logical eraseblock map command */
 507         case UBI_IOCEBMAP:
 508         {
 509                 struct ubi_map_req req;
 510
 511                 err = copy_from_user(&req, argp, sizeof(struct ubi_map_req));
 512                 if (err) {
 513                         err = -EFAULT;
 514                         break;
 515                 }
 516                 err = ubi_leb_map(desc, req.lnum);
 517                 break;
 518         }
 519
 520         /* Logical eraseblock un-map command */
 521         case UBI_IOCEBUNMAP:
 522         {
 523                 int32_t lnum;
 524
 525                 err = get_user(lnum, (__user int32_t *)argp);
 526                 if (err) {
 527                         err = -EFAULT;
 528                         break;
 529                 }
 530                 err = ubi_leb_unmap(desc, lnum);
 531                 break;
 532         }
 533
 534         /* Check if logical eraseblock is mapped command */
 535         case UBI_IOCEBISMAP:
 536         {
 537                 int32_t lnum;
 538
 539                 err = get_user(lnum, (__user int32_t *)argp);
 540                 if (err) {
 541                         err = -EFAULT;
 542                         break;
 543                 }
 544                 err = ubi_is_mapped(desc, lnum);
 545                 break;
 546         }
 547
 548         /* Set volume property command */
 549         case UBI_IOCSETVOLPROP:
 550         {
 551                 struct ubi_set_vol_prop_req req;
 552
 553                 err = copy_from_user(&req, argp,
 554                                      sizeof(struct ubi_set_vol_prop_req));
 555                 if (err) {
 556                         err = -EFAULT;
 557                         break;
 558                 }
 559                 switch (req.property) {
 560                 case UBI_VOL_PROP_DIRECT_WRITE:
 561                         mutex_lock(&ubi->device_mutex);
 562                         desc->vol->direct_writes = !!req.value;
 563                         mutex_unlock(&ubi->device_mutex);
 564                         break;
 565                 default:
 566                         err = -EINVAL;
 567                         break;
 568                 }
 569                 break;
 570         }
 571
 572         /* Create a R/O block device on top of the UBI volume */
 573         case UBI_IOCVOLCRBLK:
 574         {
 575                 struct ubi_volume_info vi;
 576
 577                 ubi_get_volume_info(desc, &vi);
 578                 err = ubiblock_create(&vi);
 579                 break;
 580         }
 581
 582         /* Remove the R/O block device */
 583         case UBI_IOCVOLRMBLK:
 584         {
 585                 struct ubi_volume_info vi;
 586
 587                 ubi_get_volume_info(desc, &vi);
 588                 err = ubiblock_remove(&vi);
 589                 break;
 590         }
 591
 592         default:
 593                 err = -ENOTTY;
 594                 break;
 595         }
 596         return err;
 597 }
 598
 599 /**
 600  * verify_mkvol_req - verify volume creation request.
 601  * @ubi: UBI device description object
 602  * @req: the request to check
 603  *
 604  * This function zero if the request is correct, and %-EINVAL if not.
 605  */
 606 static int verify_mkvol_req(const struct ubi_device *ubi,
 607                             const struct ubi_mkvol_req *req)
 608 {
 609         int n, err = -EINVAL;
 610
 611         if (req->bytes < 0 || req->alignment < 0 || req->vol_type < 0 ||
 612             req->name_len < 0)
 613                 goto bad;
 614
 615         if ((req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) &&
 616             req->vol_id != UBI_VOL_NUM_AUTO)
 617                 goto bad;
 618
 619         if (req->alignment == 0)
 620                 goto bad;
 621
 622         if (req->bytes == 0)
 623                 goto bad;
 624
 625         if (req->vol_type != UBI_DYNAMIC_VOLUME &&
 626             req->vol_type != UBI_STATIC_VOLUME)
 627                 goto bad;
 628
 629         if (req->flags & ~UBI_VOL_VALID_FLGS)
 630                 goto bad;
 631
 632         if (req->flags & UBI_VOL_SKIP_CRC_CHECK_FLG &&
 633             req->vol_type != UBI_STATIC_VOLUME)
 634                 goto bad;
 635
 636         if (req->alignment > ubi->leb_size)
 637                 goto bad;
 638
 639         n = req->alignment & (ubi->min_io_size - 1);
 640         if (req->alignment != 1 && n)
 641                 goto bad;
 642
 643         if (!req->name[0] || !req->name_len)
 644                 goto bad;
 645
 646         if (req->name_len > UBI_VOL_NAME_MAX) {
 647                 err = -ENAMETOOLONG;
 648                 goto bad;
 649         }
 650
 651         n = strnlen(req->name, req->name_len + 1);
 652         if (n != req->name_len)
 653                 goto bad;
 654
 655         return 0;
 656
 657 bad:
 658         ubi_err(ubi, "bad volume creation request");
 659         ubi_dump_mkvol_req(req);
 660         return err;
 661 }
 662
 663 /**
 664  * verify_rsvol_req - verify volume re-size request.
 665  * @ubi: UBI device description object
 666  * @req: the request to check
 667  *
 668  * This function returns zero if the request is correct, and %-EINVAL if not.
 669  */
 670 static int verify_rsvol_req(const struct ubi_device *ubi,
 671                             const struct ubi_rsvol_req *req)
 672 {
 673         if (req->bytes <= 0)
 674                 return -EINVAL;
 675
 676         if (req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots)
 677                 return -EINVAL;
 678
 679         return 0;
 680 }
 681
 682 /**
 683  * rename_volumes - rename UBI volumes.
 684  * @ubi: UBI device description object
 685  * @req: volumes re-name request
 686  *
 687  * This is a helper function for the volume re-name IOCTL which validates the
 688  * the request, opens the volume and calls corresponding volumes management
 689  * function. Returns zero in case of success and a negative error code in case
 690  * of failure.
 691  */
 692 static int rename_volumes(struct ubi_device *ubi,
 693                           struct ubi_rnvol_req *req)
 694 {
 695         int i, n, err;
 696         struct list_head rename_list;
 697         struct ubi_rename_entry *re, *re1;
 698
 699         if (req->count < 0 || req->count > UBI_MAX_RNVOL)
 700                 return -EINVAL;
 701
 702         if (req->count == 0)
 703                 return 0;
 704
 705         /* Validate volume IDs and names in the request */
 706         for (i = 0; i < req->count; i++) {
 707                 if (req->ents[i].vol_id < 0 ||
 708                     req->ents[i].vol_id >= ubi->vtbl_slots)
 709                         return -EINVAL;
 710                 if (req->ents[i].name_len < 0)
 711                         return -EINVAL;
 712                 if (req->ents[i].name_len > UBI_VOL_NAME_MAX)
 713                         return -ENAMETOOLONG;
 714                 req->ents[i].name[req->ents[i].name_len] = '\0';
 715                 n = strlen(req->ents[i].name);
 716                 if (n != req->ents[i].name_len)
 717                         return -EINVAL;
 718         }
 719
 720         /* Make sure volume IDs and names are unique */
 721         for (i = 0; i < req->count - 1; i++) {
 722                 for (n = i + 1; n < req->count; n++) {
 723                         if (req->ents[i].vol_id == req->ents[n].vol_id) {
 724                                 ubi_err(ubi, "duplicated volume id %d",
 725                                         req->ents[i].vol_id);
 726                                 return -EINVAL;
 727                         }
 728                         if (!strcmp(req->ents[i].name, req->ents[n].name)) {
 729                                 ubi_err(ubi, "duplicated volume name \"%s\"",
 730                                         req->ents[i].name);
 731                                 return -EINVAL;
 732                         }
 733                 }
 734         }
 735
 736         /* Create the re-name list */
 737         INIT_LIST_HEAD(&rename_list);
 738         for (i = 0; i < req->count; i++) {
 739                 int vol_id = req->ents[i].vol_id;
 740                 int name_len = req->ents[i].name_len;
 741                 const char *name = req->ents[i].name;
 742
 743                 re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
 744                 if (!re) {
 745                         err = -ENOMEM;
 746                         goto out_free;
 747                 }
 748
 749                 re->desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_METAONLY);
 750                 if (IS_ERR(re->desc)) {
 751                         err = PTR_ERR(re->desc);
 752                         ubi_err(ubi, "cannot open volume %d, error %d",
 753                                 vol_id, err);
 754                         kfree(re);
 755                         goto out_free;
 756                 }
 757
 758                 /* Skip this re-naming if the name does not really change */
 759                 if (re->desc->vol->name_len == name_len &&
 760                     !memcmp(re->desc->vol->name, name, name_len)) {
 761                         ubi_close_volume(re->desc);
 762                         kfree(re);
 763                         continue;
 764                 }
 765
 766                 re->new_name_len = name_len;
 767                 memcpy(re->new_name, name, name_len);
 768                 list_add_tail(&re->list, &rename_list);
 769                 dbg_gen("will rename volume %d from \"%s\" to \"%s\"",
 770                         vol_id, re->desc->vol->name, name);
 771         }
 772
 773         if (list_empty(&rename_list))
 774                 return 0;
 775
 776         /* Find out the volumes which have to be removed */
 777         list_for_each_entry(re, &rename_list, list) {
 778                 struct ubi_volume_desc *desc;
 779                 int no_remove_needed = 0;
 780
 781                 /*
 782                  * Volume @re->vol_id is going to be re-named to
 783                  * @re->new_name, while its current name is @name. If a volume
 784                  * with name @re->new_name currently exists, it has to be
 785                  * removed, unless it is also re-named in the request (@req).
 786                  */
 787                 list_for_each_entry(re1, &rename_list, list) {
 788                         if (re->new_name_len == re1->desc->vol->name_len &&
 789                             !memcmp(re->new_name, re1->desc->vol->name,
 790                                     re1->desc->vol->name_len)) {
 791                                 no_remove_needed = 1;
 792                                 break;
 793                         }
 794                 }
 795
 796                 if (no_remove_needed)
 797                         continue;
 798
 799                 /*
 800                  * It seems we need to remove volume with name @re->new_name,
 801                  * if it exists.
 802                  */
 803                 desc = ubi_open_volume_nm(ubi->ubi_num, re->new_name,
 804                                           UBI_EXCLUSIVE);
 805                 if (IS_ERR(desc)) {
 806                         err = PTR_ERR(desc);
 807                         if (err == -ENODEV)
 808                                 /* Re-naming into a non-existing volume name */
 809                                 continue;
 810
 811                         /* The volume exists but busy, or an error occurred */
 812                         ubi_err(ubi, "cannot open volume \"%s\", error %d",
 813                                 re->new_name, err);
 814                         goto out_free;
 815                 }
 816
 817                 re1 = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
 818                 if (!re1) {
 819                         err = -ENOMEM;
 820                         ubi_close_volume(desc);
 821                         goto out_free;
 822                 }
 823
 824                 re1->remove = 1;
 825                 re1->desc = desc;
 826                 list_add(&re1->list, &rename_list);
 827                 dbg_gen("will remove volume %d, name \"%s\"",
 828                         re1->desc->vol->vol_id, re1->desc->vol->name);
 829         }
 830
 831         mutex_lock(&ubi->device_mutex);
 832         err = ubi_rename_volumes(ubi, &rename_list);
 833         mutex_unlock(&ubi->device_mutex);
 834
 835 out_free:
 836         list_for_each_entry_safe(re, re1, &rename_list, list) {
 837                 ubi_close_volume(re->desc);
 838                 list_del(&re->list);
 839                 kfree(re);
 840         }
 841         return err;
 842 }
 843
 844 static long ubi_cdev_ioctl(struct file *file, unsigned int cmd,
 845                            unsigned long arg)
 846 {
 847         int err = 0;
 848         struct ubi_device *ubi;
 849         struct ubi_volume_desc *desc;
 850         void __user *argp = (void __user *)arg;
 851
 852         if (!capable(CAP_SYS_RESOURCE))
 853                 return -EPERM;
 854
 855         ubi = ubi_get_by_major(imajor(file->f_mapping->host));
 856         if (!ubi)
 857                 return -ENODEV;
 858
 859         switch (cmd) {
 860         /* Create volume command */
 861         case UBI_IOCMKVOL:
 862         {
 863                 struct ubi_mkvol_req req;
 864
 865                 dbg_gen("create volume");
 866                 err = copy_from_user(&req, argp, sizeof(struct ubi_mkvol_req));
 867                 if (err) {
 868                         err = -EFAULT;
 869                         break;
 870                 }
 871
 872                 err = verify_mkvol_req(ubi, &req);
 873                 if (err)
 874                         break;
 875
 876                 mutex_lock(&ubi->device_mutex);
 877                 err = ubi_create_volume(ubi, &req);
 878                 mutex_unlock(&ubi->device_mutex);
 879                 if (err)
 880                         break;
 881
 882                 err = put_user(req.vol_id, (__user int32_t *)argp);
 883                 if (err)
 884                         err = -EFAULT;
 885
 886                 break;
 887         }
 888
 889         /* Remove volume command */
 890         case UBI_IOCRMVOL:
 891         {
 892                 int vol_id;
 893
 894                 dbg_gen("remove volume");
 895                 err = get_user(vol_id, (__user int32_t *)argp);
 896                 if (err) {
 897                         err = -EFAULT;
 898                         break;
 899                 }
 900
 901                 desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
 902                 if (IS_ERR(desc)) {
 903                         err = PTR_ERR(desc);
 904                         break;
 905                 }
 906
 907                 mutex_lock(&ubi->device_mutex);
 908                 err = ubi_remove_volume(desc, 0);
 909                 mutex_unlock(&ubi->device_mutex);
 910
 911                 /*
 912                  * The volume is deleted (unless an error occurred), and the
 913                  * 'struct ubi_volume' object will be freed when
 914                  * 'ubi_close_volume()' will call 'put_device()'.
 915                  */
 916                 ubi_close_volume(desc);
 917                 break;
 918         }
 919
 920         /* Re-size volume command */
 921         case UBI_IOCRSVOL:
 922         {
 923                 int pebs;
 924                 struct ubi_rsvol_req req;
 925
 926                 dbg_gen("re-size volume");
 927                 err = copy_from_user(&req, argp, sizeof(struct ubi_rsvol_req));
 928                 if (err) {
 929                         err = -EFAULT;
 930                         break;
 931                 }
 932
 933                 err = verify_rsvol_req(ubi, &req);
 934                 if (err)
 935                         break;
 936
 937                 desc = ubi_open_volume(ubi->ubi_num, req.vol_id, UBI_EXCLUSIVE);
 938                 if (IS_ERR(desc)) {
 939                         err = PTR_ERR(desc);
 940                         break;
 941                 }
 942
 943                 pebs = div_u64(req.bytes + desc->vol->usable_leb_size - 1,
 944                                desc->vol->usable_leb_size);
 945
 946                 mutex_lock(&ubi->device_mutex);
 947                 err = ubi_resize_volume(desc, pebs);
 948                 mutex_unlock(&ubi->device_mutex);
 949                 ubi_close_volume(desc);
 950                 break;
 951         }
 952
 953         /* Re-name volumes command */
 954         case UBI_IOCRNVOL:
 955         {
 956                 struct ubi_rnvol_req *req;
 957
 958                 dbg_gen("re-name volumes");
 959                 req = kmalloc(sizeof(struct ubi_rnvol_req), GFP_KERNEL);
 960                 if (!req) {
 961                         err = -ENOMEM;
 962                         break;
 963                 }
 964
 965                 err = copy_from_user(req, argp, sizeof(struct ubi_rnvol_req));
 966                 if (err) {
 967                         err = -EFAULT;
 968                         kfree(req);
 969                         break;
 970                 }
 971
 972                 err = rename_volumes(ubi, req);
 973                 kfree(req);
 974                 break;
 975         }
 976
 977         default:
 978                 err = -ENOTTY;
 979                 break;
 980         }
 981
 982         ubi_put_device(ubi);
 983         return err;
 984 }
 985
 986 static long ctrl_cdev_ioctl(struct file *file, unsigned int cmd,
 987                             unsigned long arg)
 988 {
 989         int err = 0;
 990         void __user *argp = (void __user *)arg;
 991
 992         if (!capable(CAP_SYS_RESOURCE))
 993                 return -EPERM;
 994
 995         switch (cmd) {
 996         /* Attach an MTD device command */
 997         case UBI_IOCATT:
 998         {
 999                 struct ubi_attach_req req;
1000                 struct mtd_info *mtd;
1001
1002                 dbg_gen("attach MTD device");
1003                 err = copy_from_user(&req, argp, sizeof(struct ubi_attach_req));
1004                 if (err) {
1005                         err = -EFAULT;
1006                         break;
1007                 }
1008
1009                 if (req.mtd_num < 0 ||
1010                     (req.ubi_num < 0 && req.ubi_num != UBI_DEV_NUM_AUTO)) {
1011                         err = -EINVAL;
1012                         break;
1013                 }
1014
1015                 mtd = get_mtd_device(NULL, req.mtd_num);
1016                 if (IS_ERR(mtd)) {
1017                         err = PTR_ERR(mtd);
1018                         break;
1019                 }
1020
1021                 /*
1022                  * Note, further request verification is done by
1023                  * 'ubi_attach_mtd_dev()'.
1024                  */
1025                 mutex_lock(&ubi_devices_mutex);
1026                 err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset,
1027                                          req.max_beb_per1024);
1028                 mutex_unlock(&ubi_devices_mutex);
1029                 if (err < 0)
1030                         put_mtd_device(mtd);
1031                 else
1032                         /* @err contains UBI device number */
1033                         err = put_user(err, (__user int32_t *)argp);
1034
1035                 break;
1036         }
1037
1038         /* Detach an MTD device command */
1039         case UBI_IOCDET:
1040         {
1041                 int ubi_num;
1042
1043                 dbg_gen("detach MTD device");
1044                 err = get_user(ubi_num, (__user int32_t *)argp);
1045                 if (err) {
1046                         err = -EFAULT;
1047                         break;
1048                 }
1049
1050                 mutex_lock(&ubi_devices_mutex);
1051                 err = ubi_detach_mtd_dev(ubi_num, 0);
1052                 mutex_unlock(&ubi_devices_mutex);
1053                 break;
1054         }
1055
1056         default:
1057                 err = -ENOTTY;
1058                 break;
1059         }
1060
1061         return err;
1062 }
1063
1064 #ifdef CONFIG_COMPAT
1065 static long vol_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1066                                   unsigned long arg)
1067 {
1068         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1069
1070         return vol_cdev_ioctl(file, cmd, translated_arg);
1071 }
1072
1073 static long ubi_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1074                                   unsigned long arg)
1075 {
1076         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1077
1078         return ubi_cdev_ioctl(file, cmd, translated_arg);
1079 }
1080
1081 static long ctrl_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1082                                    unsigned long arg)
1083 {
1084         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1085
1086         return ctrl_cdev_ioctl(file, cmd, translated_arg);
1087 }
1088 #else
1089 #define vol_cdev_compat_ioctl  NULL
1090 #define ubi_cdev_compat_ioctl  NULL
1091 #define ctrl_cdev_compat_ioctl NULL
1092 #endif
1093
1094 /* UBI volume character device operations */
1095 const struct file_operations ubi_vol_cdev_operations = {
1096         .owner          = THIS_MODULE,
1097         .open           = vol_cdev_open,
1098         .release        = vol_cdev_release,
1099         .llseek         = vol_cdev_llseek,
1100         .read           = vol_cdev_read,
1101         .write          = vol_cdev_write,
1102         .fsync          = vol_cdev_fsync,
1103         .unlocked_ioctl = vol_cdev_ioctl,
1104         .compat_ioctl   = vol_cdev_compat_ioctl,
1105 };
1106
1107 /* UBI character device operations */
1108 const struct file_operations ubi_cdev_operations = {
1109         .owner          = THIS_MODULE,
1110         .llseek         = no_llseek,
1111         .unlocked_ioctl = ubi_cdev_ioctl,
1112         .compat_ioctl   = ubi_cdev_compat_ioctl,
1113 };
1114
1115 /* UBI control character device operations */
1116 const struct file_operations ubi_ctrl_cdev_operations = {
1117         .owner          = THIS_MODULE,
1118         .unlocked_ioctl = ctrl_cdev_ioctl,
1119         .compat_ioctl   = ctrl_cdev_compat_ioctl,
1120         .llseek         = no_llseek,
1121 };