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         mutex_lock(&inode->i_mutex);
 178         err = ubi_sync(ubi->ubi_num);
 179         mutex_unlock(&inode->i_mutex);
 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                 err = ubi_check_volume(ubi, vol->vol_id);
 371                 if (err < 0)
 372                         return err;
 373
 374                 if (err) {
 375                         ubi_warn(ubi, "volume %d on UBI device %d is corrupted",
 376                                  vol->vol_id, ubi->ubi_num);
 377                         vol->corrupted = 1;
 378                 }
 379                 vol->checked = 1;
 380                 ubi_volume_notify(ubi, vol, UBI_VOLUME_UPDATED);
 381                 revoke_exclusive(desc, UBI_READWRITE);
 382         }
 383
 384         return count;
 385 }
 386
 387 static long vol_cdev_ioctl(struct file *file, unsigned int cmd,
 388                            unsigned long arg)
 389 {
 390         int err = 0;
 391         struct ubi_volume_desc *desc = file->private_data;
 392         struct ubi_volume *vol = desc->vol;
 393         struct ubi_device *ubi = vol->ubi;
 394         void __user *argp = (void __user *)arg;
 395
 396         switch (cmd) {
 397         /* Volume update command */
 398         case UBI_IOCVOLUP:
 399         {
 400                 int64_t bytes, rsvd_bytes;
 401
 402                 if (!capable(CAP_SYS_RESOURCE)) {
 403                         err = -EPERM;
 404                         break;
 405                 }
 406
 407                 err = copy_from_user(&bytes, argp, sizeof(int64_t));
 408                 if (err) {
 409                         err = -EFAULT;
 410                         break;
 411                 }
 412
 413                 if (desc->mode == UBI_READONLY) {
 414                         err = -EROFS;
 415                         break;
 416                 }
 417
 418                 rsvd_bytes = (long long)vol->reserved_pebs *
 419                                         ubi->leb_size-vol->data_pad;
 420                 if (bytes < 0 || bytes > rsvd_bytes) {
 421                         err = -EINVAL;
 422                         break;
 423                 }
 424
 425                 err = get_exclusive(desc);
 426                 if (err < 0)
 427                         break;
 428
 429                 err = ubi_start_update(ubi, vol, bytes);
 430                 if (bytes == 0) {
 431                         ubi_volume_notify(ubi, vol, UBI_VOLUME_UPDATED);
 432                         revoke_exclusive(desc, UBI_READWRITE);
 433                 }
 434                 break;
 435         }
 436
 437         /* Atomic logical eraseblock change command */
 438         case UBI_IOCEBCH:
 439         {
 440                 struct ubi_leb_change_req req;
 441
 442                 err = copy_from_user(&req, argp,
 443                                      sizeof(struct ubi_leb_change_req));
 444                 if (err) {
 445                         err = -EFAULT;
 446                         break;
 447                 }
 448
 449                 if (desc->mode == UBI_READONLY ||
 450                     vol->vol_type == UBI_STATIC_VOLUME) {
 451                         err = -EROFS;
 452                         break;
 453                 }
 454
 455                 /* Validate the request */
 456                 err = -EINVAL;
 457                 if (req.lnum < 0 || req.lnum >= vol->reserved_pebs ||
 458                     req.bytes < 0 || req.bytes > vol->usable_leb_size)
 459                         break;
 460
 461                 err = get_exclusive(desc);
 462                 if (err < 0)
 463                         break;
 464
 465                 err = ubi_start_leb_change(ubi, vol, &req);
 466                 if (req.bytes == 0)
 467                         revoke_exclusive(desc, UBI_READWRITE);
 468                 break;
 469         }
 470
 471         /* Logical eraseblock erasure command */
 472         case UBI_IOCEBER:
 473         {
 474                 int32_t lnum;
 475
 476                 err = get_user(lnum, (__user int32_t *)argp);
 477                 if (err) {
 478                         err = -EFAULT;
 479                         break;
 480                 }
 481
 482                 if (desc->mode == UBI_READONLY ||
 483                     vol->vol_type == UBI_STATIC_VOLUME) {
 484                         err = -EROFS;
 485                         break;
 486                 }
 487
 488                 if (lnum < 0 || lnum >= vol->reserved_pebs) {
 489                         err = -EINVAL;
 490                         break;
 491                 }
 492
 493                 dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
 494                 err = ubi_eba_unmap_leb(ubi, vol, lnum);
 495                 if (err)
 496                         break;
 497
 498                 err = ubi_wl_flush(ubi, UBI_ALL, UBI_ALL);
 499                 break;
 500         }
 501
 502         /* Logical eraseblock map command */
 503         case UBI_IOCEBMAP:
 504         {
 505                 struct ubi_map_req req;
 506
 507                 err = copy_from_user(&req, argp, sizeof(struct ubi_map_req));
 508                 if (err) {
 509                         err = -EFAULT;
 510                         break;
 511                 }
 512                 err = ubi_leb_map(desc, req.lnum);
 513                 break;
 514         }
 515
 516         /* Logical eraseblock un-map command */
 517         case UBI_IOCEBUNMAP:
 518         {
 519                 int32_t lnum;
 520
 521                 err = get_user(lnum, (__user int32_t *)argp);
 522                 if (err) {
 523                         err = -EFAULT;
 524                         break;
 525                 }
 526                 err = ubi_leb_unmap(desc, lnum);
 527                 break;
 528         }
 529
 530         /* Check if logical eraseblock is mapped command */
 531         case UBI_IOCEBISMAP:
 532         {
 533                 int32_t lnum;
 534
 535                 err = get_user(lnum, (__user int32_t *)argp);
 536                 if (err) {
 537                         err = -EFAULT;
 538                         break;
 539                 }
 540                 err = ubi_is_mapped(desc, lnum);
 541                 break;
 542         }
 543
 544         /* Set volume property command */
 545         case UBI_IOCSETVOLPROP:
 546         {
 547                 struct ubi_set_vol_prop_req req;
 548
 549                 err = copy_from_user(&req, argp,
 550                                      sizeof(struct ubi_set_vol_prop_req));
 551                 if (err) {
 552                         err = -EFAULT;
 553                         break;
 554                 }
 555                 switch (req.property) {
 556                 case UBI_VOL_PROP_DIRECT_WRITE:
 557                         mutex_lock(&ubi->device_mutex);
 558                         desc->vol->direct_writes = !!req.value;
 559                         mutex_unlock(&ubi->device_mutex);
 560                         break;
 561                 default:
 562                         err = -EINVAL;
 563                         break;
 564                 }
 565                 break;
 566         }
 567
 568         /* Create a R/O block device on top of the UBI volume */
 569         case UBI_IOCVOLCRBLK:
 570         {
 571                 struct ubi_volume_info vi;
 572
 573                 ubi_get_volume_info(desc, &vi);
 574                 err = ubiblock_create(&vi);
 575                 break;
 576         }
 577
 578         /* Remove the R/O block device */
 579         case UBI_IOCVOLRMBLK:
 580         {
 581                 struct ubi_volume_info vi;
 582
 583                 ubi_get_volume_info(desc, &vi);
 584                 err = ubiblock_remove(&vi);
 585                 break;
 586         }
 587
 588         default:
 589                 err = -ENOTTY;
 590                 break;
 591         }
 592         return err;
 593 }
 594
 595 /**
 596  * verify_mkvol_req - verify volume creation request.
 597  * @ubi: UBI device description object
 598  * @req: the request to check
 599  *
 600  * This function zero if the request is correct, and %-EINVAL if not.
 601  */
 602 static int verify_mkvol_req(const struct ubi_device *ubi,
 603                             const struct ubi_mkvol_req *req)
 604 {
 605         int n, err = -EINVAL;
 606
 607         if (req->bytes < 0 || req->alignment < 0 || req->vol_type < 0 ||
 608             req->name_len < 0)
 609                 goto bad;
 610
 611         if ((req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) &&
 612             req->vol_id != UBI_VOL_NUM_AUTO)
 613                 goto bad;
 614
 615         if (req->alignment == 0)
 616                 goto bad;
 617
 618         if (req->bytes == 0)
 619                 goto bad;
 620
 621         if (req->vol_type != UBI_DYNAMIC_VOLUME &&
 622             req->vol_type != UBI_STATIC_VOLUME)
 623                 goto bad;
 624
 625         if (req->alignment > ubi->leb_size)
 626                 goto bad;
 627
 628         n = req->alignment & (ubi->min_io_size - 1);
 629         if (req->alignment != 1 && n)
 630                 goto bad;
 631
 632         if (!req->name[0] || !req->name_len)
 633                 goto bad;
 634
 635         if (req->name_len > UBI_VOL_NAME_MAX) {
 636                 err = -ENAMETOOLONG;
 637                 goto bad;
 638         }
 639
 640         n = strnlen(req->name, req->name_len + 1);
 641         if (n != req->name_len)
 642                 goto bad;
 643
 644         return 0;
 645
 646 bad:
 647         ubi_err(ubi, "bad volume creation request");
 648         ubi_dump_mkvol_req(req);
 649         return err;
 650 }
 651
 652 /**
 653  * verify_rsvol_req - verify volume re-size request.
 654  * @ubi: UBI device description object
 655  * @req: the request to check
 656  *
 657  * This function returns zero if the request is correct, and %-EINVAL if not.
 658  */
 659 static int verify_rsvol_req(const struct ubi_device *ubi,
 660                             const struct ubi_rsvol_req *req)
 661 {
 662         if (req->bytes <= 0)
 663                 return -EINVAL;
 664
 665         if (req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots)
 666                 return -EINVAL;
 667
 668         return 0;
 669 }
 670
 671 /**
 672  * rename_volumes - rename UBI volumes.
 673  * @ubi: UBI device description object
 674  * @req: volumes re-name request
 675  *
 676  * This is a helper function for the volume re-name IOCTL which validates the
 677  * the request, opens the volume and calls corresponding volumes management
 678  * function. Returns zero in case of success and a negative error code in case
 679  * of failure.
 680  */
 681 static int rename_volumes(struct ubi_device *ubi,
 682                           struct ubi_rnvol_req *req)
 683 {
 684         int i, n, err;
 685         struct list_head rename_list;
 686         struct ubi_rename_entry *re, *re1;
 687
 688         if (req->count < 0 || req->count > UBI_MAX_RNVOL)
 689                 return -EINVAL;
 690
 691         if (req->count == 0)
 692                 return 0;
 693
 694         /* Validate volume IDs and names in the request */
 695         for (i = 0; i < req->count; i++) {
 696                 if (req->ents[i].vol_id < 0 ||
 697                     req->ents[i].vol_id >= ubi->vtbl_slots)
 698                         return -EINVAL;
 699                 if (req->ents[i].name_len < 0)
 700                         return -EINVAL;
 701                 if (req->ents[i].name_len > UBI_VOL_NAME_MAX)
 702                         return -ENAMETOOLONG;
 703                 req->ents[i].name[req->ents[i].name_len] = '\0';
 704                 n = strlen(req->ents[i].name);
 705                 if (n != req->ents[i].name_len)
 706                         return -EINVAL;
 707         }
 708
 709         /* Make sure volume IDs and names are unique */
 710         for (i = 0; i < req->count - 1; i++) {
 711                 for (n = i + 1; n < req->count; n++) {
 712                         if (req->ents[i].vol_id == req->ents[n].vol_id) {
 713                                 ubi_err(ubi, "duplicated volume id %d",
 714                                         req->ents[i].vol_id);
 715                                 return -EINVAL;
 716                         }
 717                         if (!strcmp(req->ents[i].name, req->ents[n].name)) {
 718                                 ubi_err(ubi, "duplicated volume name \"%s\"",
 719                                         req->ents[i].name);
 720                                 return -EINVAL;
 721                         }
 722                 }
 723         }
 724
 725         /* Create the re-name list */
 726         INIT_LIST_HEAD(&rename_list);
 727         for (i = 0; i < req->count; i++) {
 728                 int vol_id = req->ents[i].vol_id;
 729                 int name_len = req->ents[i].name_len;
 730                 const char *name = req->ents[i].name;
 731
 732                 re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
 733                 if (!re) {
 734                         err = -ENOMEM;
 735                         goto out_free;
 736                 }
 737
 738                 re->desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_METAONLY);
 739                 if (IS_ERR(re->desc)) {
 740                         err = PTR_ERR(re->desc);
 741                         ubi_err(ubi, "cannot open volume %d, error %d",
 742                                 vol_id, err);
 743                         kfree(re);
 744                         goto out_free;
 745                 }
 746
 747                 /* Skip this re-naming if the name does not really change */
 748                 if (re->desc->vol->name_len == name_len &&
 749                     !memcmp(re->desc->vol->name, name, name_len)) {
 750                         ubi_close_volume(re->desc);
 751                         kfree(re);
 752                         continue;
 753                 }
 754
 755                 re->new_name_len = name_len;
 756                 memcpy(re->new_name, name, name_len);
 757                 list_add_tail(&re->list, &rename_list);
 758                 dbg_gen("will rename volume %d from \"%s\" to \"%s\"",
 759                         vol_id, re->desc->vol->name, name);
 760         }
 761
 762         if (list_empty(&rename_list))
 763                 return 0;
 764
 765         /* Find out the volumes which have to be removed */
 766         list_for_each_entry(re, &rename_list, list) {
 767                 struct ubi_volume_desc *desc;
 768                 int no_remove_needed = 0;
 769
 770                 /*
 771                  * Volume @re->vol_id is going to be re-named to
 772                  * @re->new_name, while its current name is @name. If a volume
 773                  * with name @re->new_name currently exists, it has to be
 774                  * removed, unless it is also re-named in the request (@req).
 775                  */
 776                 list_for_each_entry(re1, &rename_list, list) {
 777                         if (re->new_name_len == re1->desc->vol->name_len &&
 778                             !memcmp(re->new_name, re1->desc->vol->name,
 779                                     re1->desc->vol->name_len)) {
 780                                 no_remove_needed = 1;
 781                                 break;
 782                         }
 783                 }
 784
 785                 if (no_remove_needed)
 786                         continue;
 787
 788                 /*
 789                  * It seems we need to remove volume with name @re->new_name,
 790                  * if it exists.
 791                  */
 792                 desc = ubi_open_volume_nm(ubi->ubi_num, re->new_name,
 793                                           UBI_EXCLUSIVE);
 794                 if (IS_ERR(desc)) {
 795                         err = PTR_ERR(desc);
 796                         if (err == -ENODEV)
 797                                 /* Re-naming into a non-existing volume name */
 798                                 continue;
 799
 800                         /* The volume exists but busy, or an error occurred */
 801                         ubi_err(ubi, "cannot open volume \"%s\", error %d",
 802                                 re->new_name, err);
 803                         goto out_free;
 804                 }
 805
 806                 re1 = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
 807                 if (!re1) {
 808                         err = -ENOMEM;
 809                         ubi_close_volume(desc);
 810                         goto out_free;
 811                 }
 812
 813                 re1->remove = 1;
 814                 re1->desc = desc;
 815                 list_add(&re1->list, &rename_list);
 816                 dbg_gen("will remove volume %d, name \"%s\"",
 817                         re1->desc->vol->vol_id, re1->desc->vol->name);
 818         }
 819
 820         mutex_lock(&ubi->device_mutex);
 821         err = ubi_rename_volumes(ubi, &rename_list);
 822         mutex_unlock(&ubi->device_mutex);
 823
 824 out_free:
 825         list_for_each_entry_safe(re, re1, &rename_list, list) {
 826                 ubi_close_volume(re->desc);
 827                 list_del(&re->list);
 828                 kfree(re);
 829         }
 830         return err;
 831 }
 832
 833 static long ubi_cdev_ioctl(struct file *file, unsigned int cmd,
 834                            unsigned long arg)
 835 {
 836         int err = 0;
 837         struct ubi_device *ubi;
 838         struct ubi_volume_desc *desc;
 839         void __user *argp = (void __user *)arg;
 840
 841         if (!capable(CAP_SYS_RESOURCE))
 842                 return -EPERM;
 843
 844         ubi = ubi_get_by_major(imajor(file->f_mapping->host));
 845         if (!ubi)
 846                 return -ENODEV;
 847
 848         switch (cmd) {
 849         /* Create volume command */
 850         case UBI_IOCMKVOL:
 851         {
 852                 struct ubi_mkvol_req req;
 853
 854                 dbg_gen("create volume");
 855                 err = copy_from_user(&req, argp, sizeof(struct ubi_mkvol_req));
 856                 if (err) {
 857                         err = -EFAULT;
 858                         break;
 859                 }
 860
 861                 err = verify_mkvol_req(ubi, &req);
 862                 if (err)
 863                         break;
 864
 865                 mutex_lock(&ubi->device_mutex);
 866                 err = ubi_create_volume(ubi, &req);
 867                 mutex_unlock(&ubi->device_mutex);
 868                 if (err)
 869                         break;
 870
 871                 err = put_user(req.vol_id, (__user int32_t *)argp);
 872                 if (err)
 873                         err = -EFAULT;
 874
 875                 break;
 876         }
 877
 878         /* Remove volume command */
 879         case UBI_IOCRMVOL:
 880         {
 881                 int vol_id;
 882
 883                 dbg_gen("remove volume");
 884                 err = get_user(vol_id, (__user int32_t *)argp);
 885                 if (err) {
 886                         err = -EFAULT;
 887                         break;
 888                 }
 889
 890                 desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
 891                 if (IS_ERR(desc)) {
 892                         err = PTR_ERR(desc);
 893                         break;
 894                 }
 895
 896                 mutex_lock(&ubi->device_mutex);
 897                 err = ubi_remove_volume(desc, 0);
 898                 mutex_unlock(&ubi->device_mutex);
 899
 900                 /*
 901                  * The volume is deleted (unless an error occurred), and the
 902                  * 'struct ubi_volume' object will be freed when
 903                  * 'ubi_close_volume()' will call 'put_device()'.
 904                  */
 905                 ubi_close_volume(desc);
 906                 break;
 907         }
 908
 909         /* Re-size volume command */
 910         case UBI_IOCRSVOL:
 911         {
 912                 int pebs;
 913                 struct ubi_rsvol_req req;
 914
 915                 dbg_gen("re-size volume");
 916                 err = copy_from_user(&req, argp, sizeof(struct ubi_rsvol_req));
 917                 if (err) {
 918                         err = -EFAULT;
 919                         break;
 920                 }
 921
 922                 err = verify_rsvol_req(ubi, &req);
 923                 if (err)
 924                         break;
 925
 926                 desc = ubi_open_volume(ubi->ubi_num, req.vol_id, UBI_EXCLUSIVE);
 927                 if (IS_ERR(desc)) {
 928                         err = PTR_ERR(desc);
 929                         break;
 930                 }
 931
 932                 pebs = div_u64(req.bytes + desc->vol->usable_leb_size - 1,
 933                                desc->vol->usable_leb_size);
 934
 935                 mutex_lock(&ubi->device_mutex);
 936                 err = ubi_resize_volume(desc, pebs);
 937                 mutex_unlock(&ubi->device_mutex);
 938                 ubi_close_volume(desc);
 939                 break;
 940         }
 941
 942         /* Re-name volumes command */
 943         case UBI_IOCRNVOL:
 944         {
 945                 struct ubi_rnvol_req *req;
 946
 947                 dbg_gen("re-name volumes");
 948                 req = kmalloc(sizeof(struct ubi_rnvol_req), GFP_KERNEL);
 949                 if (!req) {
 950                         err = -ENOMEM;
 951                         break;
 952                 };
 953
 954                 err = copy_from_user(req, argp, sizeof(struct ubi_rnvol_req));
 955                 if (err) {
 956                         err = -EFAULT;
 957                         kfree(req);
 958                         break;
 959                 }
 960
 961                 err = rename_volumes(ubi, req);
 962                 kfree(req);
 963                 break;
 964         }
 965
 966         default:
 967                 err = -ENOTTY;
 968                 break;
 969         }
 970
 971         ubi_put_device(ubi);
 972         return err;
 973 }
 974
 975 static long ctrl_cdev_ioctl(struct file *file, unsigned int cmd,
 976                             unsigned long arg)
 977 {
 978         int err = 0;
 979         void __user *argp = (void __user *)arg;
 980
 981         if (!capable(CAP_SYS_RESOURCE))
 982                 return -EPERM;
 983
 984         switch (cmd) {
 985         /* Attach an MTD device command */
 986         case UBI_IOCATT:
 987         {
 988                 struct ubi_attach_req req;
 989                 struct mtd_info *mtd;
 990
 991                 dbg_gen("attach MTD device");
 992                 err = copy_from_user(&req, argp, sizeof(struct ubi_attach_req));
 993                 if (err) {
 994                         err = -EFAULT;
 995                         break;
 996                 }
 997
 998                 if (req.mtd_num < 0 ||
 999                     (req.ubi_num < 0 && req.ubi_num != UBI_DEV_NUM_AUTO)) {
1000                         err = -EINVAL;
1001                         break;
1002                 }
1003
1004                 mtd = get_mtd_device(NULL, req.mtd_num);
1005                 if (IS_ERR(mtd)) {
1006                         err = PTR_ERR(mtd);
1007                         break;
1008                 }
1009
1010                 /*
1011                  * Note, further request verification is done by
1012                  * 'ubi_attach_mtd_dev()'.
1013                  */
1014                 mutex_lock(&ubi_devices_mutex);
1015                 err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset,
1016                                          req.max_beb_per1024);
1017                 mutex_unlock(&ubi_devices_mutex);
1018                 if (err < 0)
1019                         put_mtd_device(mtd);
1020                 else
1021                         /* @err contains UBI device number */
1022                         err = put_user(err, (__user int32_t *)argp);
1023
1024                 break;
1025         }
1026
1027         /* Detach an MTD device command */
1028         case UBI_IOCDET:
1029         {
1030                 int ubi_num;
1031
1032                 dbg_gen("detach MTD device");
1033                 err = get_user(ubi_num, (__user int32_t *)argp);
1034                 if (err) {
1035                         err = -EFAULT;
1036                         break;
1037                 }
1038
1039                 mutex_lock(&ubi_devices_mutex);
1040                 err = ubi_detach_mtd_dev(ubi_num, 0);
1041                 mutex_unlock(&ubi_devices_mutex);
1042                 break;
1043         }
1044
1045         default:
1046                 err = -ENOTTY;
1047                 break;
1048         }
1049
1050         return err;
1051 }
1052
1053 #ifdef CONFIG_COMPAT
1054 static long vol_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1055                                   unsigned long arg)
1056 {
1057         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1058
1059         return vol_cdev_ioctl(file, cmd, translated_arg);
1060 }
1061
1062 static long ubi_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1063                                   unsigned long arg)
1064 {
1065         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1066
1067         return ubi_cdev_ioctl(file, cmd, translated_arg);
1068 }
1069
1070 static long ctrl_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1071                                    unsigned long arg)
1072 {
1073         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1074
1075         return ctrl_cdev_ioctl(file, cmd, translated_arg);
1076 }
1077 #else
1078 #define vol_cdev_compat_ioctl  NULL
1079 #define ubi_cdev_compat_ioctl  NULL
1080 #define ctrl_cdev_compat_ioctl NULL
1081 #endif
1082
1083 /* UBI volume character device operations */
1084 const struct file_operations ubi_vol_cdev_operations = {
1085         .owner          = THIS_MODULE,
1086         .open           = vol_cdev_open,
1087         .release        = vol_cdev_release,
1088         .llseek         = vol_cdev_llseek,
1089         .read           = vol_cdev_read,
1090         .write          = vol_cdev_write,
1091         .fsync          = vol_cdev_fsync,
1092         .unlocked_ioctl = vol_cdev_ioctl,
1093         .compat_ioctl   = vol_cdev_compat_ioctl,
1094 };
1095
1096 /* UBI character device operations */
1097 const struct file_operations ubi_cdev_operations = {
1098         .owner          = THIS_MODULE,
1099         .llseek         = no_llseek,
1100         .unlocked_ioctl = ubi_cdev_ioctl,
1101         .compat_ioctl   = ubi_cdev_compat_ioctl,
1102 };
1103
1104 /* UBI control character device operations */
1105 const struct file_operations ubi_ctrl_cdev_operations = {
1106         .owner          = THIS_MODULE,
1107         .unlocked_ioctl = ctrl_cdev_ioctl,
1108         .compat_ioctl   = ctrl_cdev_compat_ioctl,
1109         .llseek         = no_llseek,
1110 };