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;
  64         ubi_assert(users > 0);
  65         if (users > 1) {
  66                 ubi_err("%d users for volume %d", users, vol->vol_id);
  67                 err = -EBUSY;
  68         } else {
  69                 vol->readers = vol->writers = 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);
  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
  97                 vol->exclusive = 1;
  98         spin_unlock(&vol->ubi->volumes_lock);
  99
 100         desc->mode = mode;
 101 }
 102
 103 static int vol_cdev_open(struct inode *inode, struct file *file)
 104 {
 105         struct ubi_volume_desc *desc;
 106         int vol_id = iminor(inode) - 1, mode, ubi_num;
 107
 108         ubi_num = ubi_major2num(imajor(inode));
 109         if (ubi_num < 0)
 110                 return ubi_num;
 111
 112         if (file->f_mode & FMODE_WRITE)
 113                 mode = UBI_READWRITE;
 114         else
 115                 mode = UBI_READONLY;
 116
 117         dbg_gen("open device %d, volume %d, mode %d",
 118                 ubi_num, vol_id, mode);
 119
 120         desc = ubi_open_volume(ubi_num, vol_id, mode);
 121         if (IS_ERR(desc))
 122                 return PTR_ERR(desc);
 123
 124         file->private_data = desc;
 125         return 0;
 126 }
 127
 128 static int vol_cdev_release(struct inode *inode, struct file *file)
 129 {
 130         struct ubi_volume_desc *desc = file->private_data;
 131         struct ubi_volume *vol = desc->vol;
 132
 133         dbg_gen("release device %d, volume %d, mode %d",
 134                 vol->ubi->ubi_num, vol->vol_id, desc->mode);
 135
 136         if (vol->updating) {
 137                 ubi_warn("update of volume %d not finished, volume is damaged",
 138                          vol->vol_id);
 139                 ubi_assert(!vol->changing_leb);
 140                 vol->updating = 0;
 141                 vfree(vol->upd_buf);
 142         } else if (vol->changing_leb) {
 143                 dbg_gen("only %lld of %lld bytes received for atomic LEB change"
 144                         " for volume %d:%d, cancel", vol->upd_received,
 145                         vol->upd_bytes, vol->ubi->ubi_num, vol->vol_id);
 146                 vol->changing_leb = 0;
 147                 vfree(vol->upd_buf);
 148         }
 149
 150         ubi_close_volume(desc);
 151         return 0;
 152 }
 153
 154 static loff_t vol_cdev_llseek(struct file *file, loff_t offset, int origin)
 155 {
 156         struct ubi_volume_desc *desc = file->private_data;
 157         struct ubi_volume *vol = desc->vol;
 158         loff_t new_offset;
 159
 160         if (vol->updating) {
 161                 /* Update is in progress, seeking is prohibited */
 162                 ubi_err("updating");
 163                 return -EBUSY;
 164         }
 165
 166         switch (origin) {
 167         case 0: /* SEEK_SET */
 168                 new_offset = offset;
 169                 break;
 170         case 1: /* SEEK_CUR */
 171                 new_offset = file->f_pos + offset;
 172                 break;
 173         case 2: /* SEEK_END */
 174                 new_offset = vol->used_bytes + offset;
 175                 break;
 176         default:
 177                 return -EINVAL;
 178         }
 179
 180         if (new_offset < 0 || new_offset > vol->used_bytes) {
 181                 ubi_err("bad seek %lld", new_offset);
 182                 return -EINVAL;
 183         }
 184
 185         dbg_gen("seek volume %d, offset %lld, origin %d, new offset %lld",
 186                 vol->vol_id, offset, origin, new_offset);
 187
 188         file->f_pos = new_offset;
 189         return new_offset;
 190 }
 191
 192 static int vol_cdev_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 193 {
 194         struct ubi_volume_desc *desc = file->private_data;
 195         struct ubi_device *ubi = desc->vol->ubi;
 196         struct inode *inode = file->f_path.dentry->d_inode;
 197         int err;
 198         mutex_lock(&inode->i_mutex);
 199         err = ubi_sync(ubi->ubi_num);
 200         mutex_unlock(&inode->i_mutex);
 201         return err;
 202 }
 203
 204
 205 static ssize_t vol_cdev_read(struct file *file, __user char *buf, size_t count,
 206                              loff_t *offp)
 207 {
 208         struct ubi_volume_desc *desc = file->private_data;
 209         struct ubi_volume *vol = desc->vol;
 210         struct ubi_device *ubi = vol->ubi;
 211         int err, lnum, off, len,  tbuf_size;
 212         size_t count_save = count;
 213         void *tbuf;
 214
 215         dbg_gen("read %zd bytes from offset %lld of volume %d",
 216                 count, *offp, vol->vol_id);
 217
 218         if (vol->updating) {
 219                 ubi_err("updating");
 220                 return -EBUSY;
 221         }
 222         if (vol->upd_marker) {
 223                 ubi_err("damaged volume, update marker is set");
 224                 return -EBADF;
 225         }
 226         if (*offp == vol->used_bytes || count == 0)
 227                 return 0;
 228
 229         if (vol->corrupted)
 230                 dbg_gen("read from corrupted volume %d", vol->vol_id);
 231
 232         if (*offp + count > vol->used_bytes)
 233                 count_save = count = vol->used_bytes - *offp;
 234
 235         tbuf_size = vol->usable_leb_size;
 236         if (count < tbuf_size)
 237                 tbuf_size = ALIGN(count, ubi->min_io_size);
 238         tbuf = vmalloc(tbuf_size);
 239         if (!tbuf)
 240                 return -ENOMEM;
 241
 242         len = count > tbuf_size ? tbuf_size : count;
 243         lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
 244
 245         do {
 246                 cond_resched();
 247
 248                 if (off + len >= vol->usable_leb_size)
 249                         len = vol->usable_leb_size - off;
 250
 251                 err = ubi_eba_read_leb(ubi, vol, lnum, tbuf, off, len, 0);
 252                 if (err)
 253                         break;
 254
 255                 off += len;
 256                 if (off == vol->usable_leb_size) {
 257                         lnum += 1;
 258                         off -= vol->usable_leb_size;
 259                 }
 260
 261                 count -= len;
 262                 *offp += len;
 263
 264                 err = copy_to_user(buf, tbuf, len);
 265                 if (err) {
 266                         err = -EFAULT;
 267                         break;
 268                 }
 269
 270                 buf += len;
 271                 len = count > tbuf_size ? tbuf_size : count;
 272         } while (count);
 273
 274         vfree(tbuf);
 275         return err ? err : count_save - count;
 276 }
 277
 278 /*
 279  * This function allows to directly write to dynamic UBI volumes, without
 280  * issuing the volume update operation.
 281  */
 282 static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
 283                                      size_t count, loff_t *offp)
 284 {
 285         struct ubi_volume_desc *desc = file->private_data;
 286         struct ubi_volume *vol = desc->vol;
 287         struct ubi_device *ubi = vol->ubi;
 288         int lnum, off, len, tbuf_size, err = 0;
 289         size_t count_save = count;
 290         char *tbuf;
 291
 292         if (!vol->direct_writes)
 293                 return -EPERM;
 294
 295         dbg_gen("requested: write %zd bytes to offset %lld of volume %u",
 296                 count, *offp, vol->vol_id);
 297
 298         if (vol->vol_type == UBI_STATIC_VOLUME)
 299                 return -EROFS;
 300
 301         lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
 302         if (off & (ubi->min_io_size - 1)) {
 303                 ubi_err("unaligned position");
 304                 return -EINVAL;
 305         }
 306
 307         if (*offp + count > vol->used_bytes)
 308                 count_save = count = vol->used_bytes - *offp;
 309
 310         /* We can write only in fractions of the minimum I/O unit */
 311         if (count & (ubi->min_io_size - 1)) {
 312                 ubi_err("unaligned write length");
 313                 return -EINVAL;
 314         }
 315
 316         tbuf_size = vol->usable_leb_size;
 317         if (count < tbuf_size)
 318                 tbuf_size = ALIGN(count, ubi->min_io_size);
 319         tbuf = vmalloc(tbuf_size);
 320         if (!tbuf)
 321                 return -ENOMEM;
 322
 323         len = count > tbuf_size ? tbuf_size : count;
 324
 325         while (count) {
 326                 cond_resched();
 327
 328                 if (off + len >= vol->usable_leb_size)
 329                         len = vol->usable_leb_size - off;
 330
 331                 err = copy_from_user(tbuf, buf, len);
 332                 if (err) {
 333                         err = -EFAULT;
 334                         break;
 335                 }
 336
 337                 err = ubi_eba_write_leb(ubi, vol, lnum, tbuf, off, len);
 338                 if (err)
 339                         break;
 340
 341                 off += len;
 342                 if (off == vol->usable_leb_size) {
 343                         lnum += 1;
 344                         off -= vol->usable_leb_size;
 345                 }
 346
 347                 count -= len;
 348                 *offp += len;
 349                 buf += len;
 350                 len = count > tbuf_size ? tbuf_size : count;
 351         }
 352
 353         vfree(tbuf);
 354         return err ? err : count_save - count;
 355 }
 356
 357 static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
 358                               size_t count, loff_t *offp)
 359 {
 360         int err = 0;
 361         struct ubi_volume_desc *desc = file->private_data;
 362         struct ubi_volume *vol = desc->vol;
 363         struct ubi_device *ubi = vol->ubi;
 364
 365         if (!vol->updating && !vol->changing_leb)
 366                 return vol_cdev_direct_write(file, buf, count, offp);
 367
 368         if (vol->updating)
 369                 err = ubi_more_update_data(ubi, vol, buf, count);
 370         else
 371                 err = ubi_more_leb_change_data(ubi, vol, buf, count);
 372
 373         if (err < 0) {
 374                 ubi_err("cannot accept more %zd bytes of data, error %d",
 375                         count, err);
 376                 return err;
 377         }
 378
 379         if (err) {
 380                 /*
 381                  * The operation is finished, @err contains number of actually
 382                  * written bytes.
 383                  */
 384                 count = err;
 385
 386                 if (vol->changing_leb) {
 387                         revoke_exclusive(desc, UBI_READWRITE);
 388                         return count;
 389                 }
 390
 391                 err = ubi_check_volume(ubi, vol->vol_id);
 392                 if (err < 0)
 393                         return err;
 394
 395                 if (err) {
 396                         ubi_warn("volume %d on UBI device %d is corrupted",
 397                                  vol->vol_id, ubi->ubi_num);
 398                         vol->corrupted = 1;
 399                 }
 400                 vol->checked = 1;
 401                 ubi_volume_notify(ubi, vol, UBI_VOLUME_UPDATED);
 402                 revoke_exclusive(desc, UBI_READWRITE);
 403         }
 404
 405         return count;
 406 }
 407
 408 static long vol_cdev_ioctl(struct file *file, unsigned int cmd,
 409                            unsigned long arg)
 410 {
 411         int err = 0;
 412         struct ubi_volume_desc *desc = file->private_data;
 413         struct ubi_volume *vol = desc->vol;
 414         struct ubi_device *ubi = vol->ubi;
 415         void __user *argp = (void __user *)arg;
 416
 417         switch (cmd) {
 418         /* Volume update command */
 419         case UBI_IOCVOLUP:
 420         {
 421                 int64_t bytes, rsvd_bytes;
 422
 423                 if (!capable(CAP_SYS_RESOURCE)) {
 424                         err = -EPERM;
 425                         break;
 426                 }
 427
 428                 err = copy_from_user(&bytes, argp, sizeof(int64_t));
 429                 if (err) {
 430                         err = -EFAULT;
 431                         break;
 432                 }
 433
 434                 if (desc->mode == UBI_READONLY) {
 435                         err = -EROFS;
 436                         break;
 437                 }
 438
 439                 rsvd_bytes = (long long)vol->reserved_pebs *
 440                                         ubi->leb_size-vol->data_pad;
 441                 if (bytes < 0 || bytes > rsvd_bytes) {
 442                         err = -EINVAL;
 443                         break;
 444                 }
 445
 446                 err = get_exclusive(desc);
 447                 if (err < 0)
 448                         break;
 449
 450                 err = ubi_start_update(ubi, vol, bytes);
 451                 if (bytes == 0)
 452                         revoke_exclusive(desc, UBI_READWRITE);
 453                 break;
 454         }
 455
 456         /* Atomic logical eraseblock change command */
 457         case UBI_IOCEBCH:
 458         {
 459                 struct ubi_leb_change_req req;
 460
 461                 err = copy_from_user(&req, argp,
 462                                      sizeof(struct ubi_leb_change_req));
 463                 if (err) {
 464                         err = -EFAULT;
 465                         break;
 466                 }
 467
 468                 if (desc->mode == UBI_READONLY ||
 469                     vol->vol_type == UBI_STATIC_VOLUME) {
 470                         err = -EROFS;
 471                         break;
 472                 }
 473
 474                 /* Validate the request */
 475                 err = -EINVAL;
 476                 if (req.lnum < 0 || req.lnum >= vol->reserved_pebs ||
 477                     req.bytes < 0 || req.lnum >= vol->usable_leb_size)
 478                         break;
 479
 480                 err = get_exclusive(desc);
 481                 if (err < 0)
 482                         break;
 483
 484                 err = ubi_start_leb_change(ubi, vol, &req);
 485                 if (req.bytes == 0)
 486                         revoke_exclusive(desc, UBI_READWRITE);
 487                 break;
 488         }
 489
 490         /* Logical eraseblock erasure command */
 491         case UBI_IOCEBER:
 492         {
 493                 int32_t lnum;
 494
 495                 err = get_user(lnum, (__user int32_t *)argp);
 496                 if (err) {
 497                         err = -EFAULT;
 498                         break;
 499                 }
 500
 501                 if (desc->mode == UBI_READONLY ||
 502                     vol->vol_type == UBI_STATIC_VOLUME) {
 503                         err = -EROFS;
 504                         break;
 505                 }
 506
 507                 if (lnum < 0 || lnum >= vol->reserved_pebs) {
 508                         err = -EINVAL;
 509                         break;
 510                 }
 511
 512                 dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
 513                 err = ubi_eba_unmap_leb(ubi, vol, lnum);
 514                 if (err)
 515                         break;
 516
 517                 err = ubi_wl_flush(ubi, UBI_ALL, UBI_ALL);
 518                 break;
 519         }
 520
 521         /* Logical eraseblock map command */
 522         case UBI_IOCEBMAP:
 523         {
 524                 struct ubi_map_req req;
 525
 526                 err = copy_from_user(&req, argp, sizeof(struct ubi_map_req));
 527                 if (err) {
 528                         err = -EFAULT;
 529                         break;
 530                 }
 531                 err = ubi_leb_map(desc, req.lnum);
 532                 break;
 533         }
 534
 535         /* Logical eraseblock un-map command */
 536         case UBI_IOCEBUNMAP:
 537         {
 538                 int32_t lnum;
 539
 540                 err = get_user(lnum, (__user int32_t *)argp);
 541                 if (err) {
 542                         err = -EFAULT;
 543                         break;
 544                 }
 545                 err = ubi_leb_unmap(desc, lnum);
 546                 break;
 547         }
 548
 549         /* Check if logical eraseblock is mapped command */
 550         case UBI_IOCEBISMAP:
 551         {
 552                 int32_t lnum;
 553
 554                 err = get_user(lnum, (__user int32_t *)argp);
 555                 if (err) {
 556                         err = -EFAULT;
 557                         break;
 558                 }
 559                 err = ubi_is_mapped(desc, lnum);
 560                 break;
 561         }
 562
 563         /* Set volume property command */
 564         case UBI_IOCSETVOLPROP:
 565         {
 566                 struct ubi_set_vol_prop_req req;
 567
 568                 err = copy_from_user(&req, argp,
 569                                      sizeof(struct ubi_set_vol_prop_req));
 570                 if (err) {
 571                         err = -EFAULT;
 572                         break;
 573                 }
 574                 switch (req.property) {
 575                 case UBI_VOL_PROP_DIRECT_WRITE:
 576                         mutex_lock(&ubi->device_mutex);
 577                         desc->vol->direct_writes = !!req.value;
 578                         mutex_unlock(&ubi->device_mutex);
 579                         break;
 580                 default:
 581                         err = -EINVAL;
 582                         break;
 583                 }
 584                 break;
 585         }
 586
 587         default:
 588                 err = -ENOTTY;
 589                 break;
 590         }
 591         return err;
 592 }
 593
 594 /**
 595  * verify_mkvol_req - verify volume creation request.
 596  * @ubi: UBI device description object
 597  * @req: the request to check
 598  *
 599  * This function zero if the request is correct, and %-EINVAL if not.
 600  */
 601 static int verify_mkvol_req(const struct ubi_device *ubi,
 602                             const struct ubi_mkvol_req *req)
 603 {
 604         int n, err = -EINVAL;
 605
 606         if (req->bytes < 0 || req->alignment < 0 || req->vol_type < 0 ||
 607             req->name_len < 0)
 608                 goto bad;
 609
 610         if ((req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) &&
 611             req->vol_id != UBI_VOL_NUM_AUTO)
 612                 goto bad;
 613
 614         if (req->alignment == 0)
 615                 goto bad;
 616
 617         if (req->bytes == 0)
 618                 goto bad;
 619
 620         if (req->vol_type != UBI_DYNAMIC_VOLUME &&
 621             req->vol_type != UBI_STATIC_VOLUME)
 622                 goto bad;
 623
 624         if (req->alignment > ubi->leb_size)
 625                 goto bad;
 626
 627         n = req->alignment & (ubi->min_io_size - 1);
 628         if (req->alignment != 1 && n)
 629                 goto bad;
 630
 631         if (!req->name[0] || !req->name_len)
 632                 goto bad;
 633
 634         if (req->name_len > UBI_VOL_NAME_MAX) {
 635                 err = -ENAMETOOLONG;
 636                 goto bad;
 637         }
 638
 639         n = strnlen(req->name, req->name_len + 1);
 640         if (n != req->name_len)
 641                 goto bad;
 642
 643         return 0;
 644
 645 bad:
 646         ubi_err("bad volume creation request");
 647         ubi_dump_mkvol_req(req);
 648         return err;
 649 }
 650
 651 /**
 652  * verify_rsvol_req - verify volume re-size request.
 653  * @ubi: UBI device description object
 654  * @req: the request to check
 655  *
 656  * This function returns zero if the request is correct, and %-EINVAL if not.
 657  */
 658 static int verify_rsvol_req(const struct ubi_device *ubi,
 659                             const struct ubi_rsvol_req *req)
 660 {
 661         if (req->bytes <= 0)
 662                 return -EINVAL;
 663
 664         if (req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots)
 665                 return -EINVAL;
 666
 667         return 0;
 668 }
 669
 670 /**
 671  * rename_volumes - rename UBI volumes.
 672  * @ubi: UBI device description object
 673  * @req: volumes re-name request
 674  *
 675  * This is a helper function for the volume re-name IOCTL which validates the
 676  * the request, opens the volume and calls corresponding volumes management
 677  * function. Returns zero in case of success and a negative error code in case
 678  * of failure.
 679  */
 680 static int rename_volumes(struct ubi_device *ubi,
 681                           struct ubi_rnvol_req *req)
 682 {
 683         int i, n, err;
 684         struct list_head rename_list;
 685         struct ubi_rename_entry *re, *re1;
 686
 687         if (req->count < 0 || req->count > UBI_MAX_RNVOL)
 688                 return -EINVAL;
 689
 690         if (req->count == 0)
 691                 return 0;
 692
 693         /* Validate volume IDs and names in the request */
 694         for (i = 0; i < req->count; i++) {
 695                 if (req->ents[i].vol_id < 0 ||
 696                     req->ents[i].vol_id >= ubi->vtbl_slots)
 697                         return -EINVAL;
 698                 if (req->ents[i].name_len < 0)
 699                         return -EINVAL;
 700                 if (req->ents[i].name_len > UBI_VOL_NAME_MAX)
 701                         return -ENAMETOOLONG;
 702                 req->ents[i].name[req->ents[i].name_len] = '\0';
 703                 n = strlen(req->ents[i].name);
 704                 if (n != req->ents[i].name_len)
 705                         err = -EINVAL;
 706         }
 707
 708         /* Make sure volume IDs and names are unique */
 709         for (i = 0; i < req->count - 1; i++) {
 710                 for (n = i + 1; n < req->count; n++) {
 711                         if (req->ents[i].vol_id == req->ents[n].vol_id) {
 712                                 ubi_err("duplicated volume id %d",
 713                                         req->ents[i].vol_id);
 714                                 return -EINVAL;
 715                         }
 716                         if (!strcmp(req->ents[i].name, req->ents[n].name)) {
 717                                 ubi_err("duplicated volume name \"%s\"",
 718                                         req->ents[i].name);
 719                                 return -EINVAL;
 720                         }
 721                 }
 722         }
 723
 724         /* Create the re-name list */
 725         INIT_LIST_HEAD(&rename_list);
 726         for (i = 0; i < req->count; i++) {
 727                 int vol_id = req->ents[i].vol_id;
 728                 int name_len = req->ents[i].name_len;
 729                 const char *name = req->ents[i].name;
 730
 731                 re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
 732                 if (!re) {
 733                         err = -ENOMEM;
 734                         goto out_free;
 735                 }
 736
 737                 re->desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
 738                 if (IS_ERR(re->desc)) {
 739                         err = PTR_ERR(re->desc);
 740                         ubi_err("cannot open volume %d, error %d", 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_msg("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("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_msg("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
 822 out_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
 831 static 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_msg("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         default:
 965                 err = -ENOTTY;
 966                 break;
 967         }
 968
 969         ubi_put_device(ubi);
 970         return err;
 971 }
 972
 973 static long ctrl_cdev_ioctl(struct file *file, unsigned int cmd,
 974                             unsigned long arg)
 975 {
 976         int err = 0;
 977         void __user *argp = (void __user *)arg;
 978
 979         if (!capable(CAP_SYS_RESOURCE))
 980                 return -EPERM;
 981
 982         switch (cmd) {
 983         /* Attach an MTD device command */
 984         case UBI_IOCATT:
 985         {
 986                 struct ubi_attach_req req;
 987                 struct mtd_info *mtd;
 988
 989                 dbg_gen("attach MTD device");
 990                 err = copy_from_user(&req, argp, sizeof(struct ubi_attach_req));
 991                 if (err) {
 992                         err = -EFAULT;
 993                         break;
 994                 }
 995
 996                 if (req.mtd_num < 0 ||
 997                     (req.ubi_num < 0 && req.ubi_num != UBI_DEV_NUM_AUTO)) {
 998                         err = -EINVAL;
 999                         break;
1000                 }
1001
1002                 mtd = get_mtd_device(NULL, req.mtd_num);
1003                 if (IS_ERR(mtd)) {
1004                         err = PTR_ERR(mtd);
1005                         break;
1006                 }
1007
1008                 /*
1009                  * Note, further request verification is done by
1010                  * 'ubi_attach_mtd_dev()'.
1011                  */
1012                 mutex_lock(&ubi_devices_mutex);
1013                 err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset);
1014                 mutex_unlock(&ubi_devices_mutex);
1015                 if (err < 0)
1016                         put_mtd_device(mtd);
1017                 else
1018                         /* @err contains UBI device number */
1019                         err = put_user(err, (__user int32_t *)argp);
1020
1021                 break;
1022         }
1023
1024         /* Detach an MTD device command */
1025         case UBI_IOCDET:
1026         {
1027                 int ubi_num;
1028
1029                 dbg_gen("detach MTD device");
1030                 err = get_user(ubi_num, (__user int32_t *)argp);
1031                 if (err) {
1032                         err = -EFAULT;
1033                         break;
1034                 }
1035
1036                 mutex_lock(&ubi_devices_mutex);
1037                 err = ubi_detach_mtd_dev(ubi_num, 0);
1038                 mutex_unlock(&ubi_devices_mutex);
1039                 break;
1040         }
1041
1042         default:
1043                 err = -ENOTTY;
1044                 break;
1045         }
1046
1047         return err;
1048 }
1049
1050 #ifdef CONFIG_COMPAT
1051 static long vol_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1052                                   unsigned long arg)
1053 {
1054         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1055
1056         return vol_cdev_ioctl(file, cmd, translated_arg);
1057 }
1058
1059 static long ubi_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1060                                   unsigned long arg)
1061 {
1062         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1063
1064         return ubi_cdev_ioctl(file, cmd, translated_arg);
1065 }
1066
1067 static long ctrl_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1068                                    unsigned long arg)
1069 {
1070         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1071
1072         return ctrl_cdev_ioctl(file, cmd, translated_arg);
1073 }
1074 #else
1075 #define vol_cdev_compat_ioctl  NULL
1076 #define ubi_cdev_compat_ioctl  NULL
1077 #define ctrl_cdev_compat_ioctl NULL
1078 #endif
1079
1080 /* UBI volume character device operations */
1081 const struct file_operations ubi_vol_cdev_operations = {
1082         .owner          = THIS_MODULE,
1083         .open           = vol_cdev_open,
1084         .release        = vol_cdev_release,
1085         .llseek         = vol_cdev_llseek,
1086         .read           = vol_cdev_read,
1087         .write          = vol_cdev_write,
1088         .fsync          = vol_cdev_fsync,
1089         .unlocked_ioctl = vol_cdev_ioctl,
1090         .compat_ioctl   = vol_cdev_compat_ioctl,
1091 };
1092
1093 /* UBI character device operations */
1094 const struct file_operations ubi_cdev_operations = {
1095         .owner          = THIS_MODULE,
1096         .llseek         = no_llseek,
1097         .unlocked_ioctl = ubi_cdev_ioctl,
1098         .compat_ioctl   = ubi_cdev_compat_ioctl,
1099 };
1100
1101 /* UBI control character device operations */
1102 const struct file_operations ubi_ctrl_cdev_operations = {
1103         .owner          = THIS_MODULE,
1104         .unlocked_ioctl = ctrl_cdev_ioctl,
1105         .compat_ioctl   = ctrl_cdev_compat_ioctl,
1106         .llseek         = no_llseek,
1107 };