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/ioctl.h>
  41 #include <linux/capability.h>
  42 #include <linux/uaccess.h>
  43 #include <linux/compat.h>
  44 #include <linux/math64.h>
  45 #include <mtd/ubi-user.h>
  46 #include "ubi.h"
  47
  48 /**
  49  * get_exclusive - get exclusive access to an UBI volume.
  50  * @desc: volume descriptor
  51  *
  52  * This function changes UBI volume open mode to "exclusive". Returns previous
  53  * mode value (positive integer) in case of success and a negative error code
  54  * in case of failure.
  55  */
  56 static int get_exclusive(struct ubi_volume_desc *desc)
  57 {
  58         int users, err;
  59         struct ubi_volume *vol = desc->vol;
  60
  61         spin_lock(&vol->ubi->volumes_lock);
  62         users = vol->readers + vol->writers + vol->exclusive;
  63         ubi_assert(users > 0);
  64         if (users > 1) {
  65                 dbg_err("%d users for volume %d", users, vol->vol_id);
  66                 err = -EBUSY;
  67         } else {
  68                 vol->readers = vol->writers = 0;
  69                 vol->exclusive = 1;
  70                 err = desc->mode;
  71                 desc->mode = UBI_EXCLUSIVE;
  72         }
  73         spin_unlock(&vol->ubi->volumes_lock);
  74
  75         return err;
  76 }
  77
  78 /**
  79  * revoke_exclusive - revoke exclusive mode.
  80  * @desc: volume descriptor
  81  * @mode: new mode to switch to
  82  */
  83 static void revoke_exclusive(struct ubi_volume_desc *desc, int mode)
  84 {
  85         struct ubi_volume *vol = desc->vol;
  86
  87         spin_lock(&vol->ubi->volumes_lock);
  88         ubi_assert(vol->readers == 0 && vol->writers == 0);
  89         ubi_assert(vol->exclusive == 1 && desc->mode == UBI_EXCLUSIVE);
  90         vol->exclusive = 0;
  91         if (mode == UBI_READONLY)
  92                 vol->readers = 1;
  93         else if (mode == UBI_READWRITE)
  94                 vol->writers = 1;
  95         else
  96                 vol->exclusive = 1;
  97         spin_unlock(&vol->ubi->volumes_lock);
  98
  99         desc->mode = mode;
 100 }
 101
 102 static int vol_cdev_open(struct inode *inode, struct file *file)
 103 {
 104         struct ubi_volume_desc *desc;
 105         int vol_id = iminor(inode) - 1, mode, ubi_num;
 106
 107         ubi_num = ubi_major2num(imajor(inode));
 108         if (ubi_num < 0)
 109                 return ubi_num;
 110
 111         if (file->f_mode & FMODE_WRITE)
 112                 mode = UBI_READWRITE;
 113         else
 114                 mode = UBI_READONLY;
 115
 116         dbg_gen("open volume %d, mode %d", vol_id, mode);
 117
 118         desc = ubi_open_volume(ubi_num, vol_id, mode);
 119         if (IS_ERR(desc))
 120                 return PTR_ERR(desc);
 121
 122         file->private_data = desc;
 123         return 0;
 124 }
 125
 126 static int vol_cdev_release(struct inode *inode, struct file *file)
 127 {
 128         struct ubi_volume_desc *desc = file->private_data;
 129         struct ubi_volume *vol = desc->vol;
 130
 131         dbg_gen("release volume %d, mode %d", vol->vol_id, desc->mode);
 132
 133         if (vol->updating) {
 134                 ubi_warn("update of volume %d not finished, volume is damaged",
 135                          vol->vol_id);
 136                 ubi_assert(!vol->changing_leb);
 137                 vol->updating = 0;
 138                 vfree(vol->upd_buf);
 139         } else if (vol->changing_leb) {
 140                 dbg_gen("only %lld of %lld bytes received for atomic LEB change"
 141                         " for volume %d:%d, cancel", vol->upd_received,
 142                         vol->upd_bytes, vol->ubi->ubi_num, vol->vol_id);
 143                 vol->changing_leb = 0;
 144                 vfree(vol->upd_buf);
 145         }
 146
 147         ubi_close_volume(desc);
 148         return 0;
 149 }
 150
 151 static loff_t vol_cdev_llseek(struct file *file, loff_t offset, int origin)
 152 {
 153         struct ubi_volume_desc *desc = file->private_data;
 154         struct ubi_volume *vol = desc->vol;
 155         loff_t new_offset;
 156
 157         if (vol->updating) {
 158                  /* Update is in progress, seeking is prohibited */
 159                 dbg_err("updating");
 160                 return -EBUSY;
 161         }
 162
 163         switch (origin) {
 164         case 0: /* SEEK_SET */
 165                 new_offset = offset;
 166                 break;
 167         case 1: /* SEEK_CUR */
 168                 new_offset = file->f_pos + offset;
 169                 break;
 170         case 2: /* SEEK_END */
 171                 new_offset = vol->used_bytes + offset;
 172                 break;
 173         default:
 174                 return -EINVAL;
 175         }
 176
 177         if (new_offset < 0 || new_offset > vol->used_bytes) {
 178                 dbg_err("bad seek %lld", new_offset);
 179                 return -EINVAL;
 180         }
 181
 182         dbg_gen("seek volume %d, offset %lld, origin %d, new offset %lld",
 183                 vol->vol_id, offset, origin, new_offset);
 184
 185         file->f_pos = new_offset;
 186         return new_offset;
 187 }
 188
 189 static ssize_t vol_cdev_read(struct file *file, __user char *buf, size_t count,
 190                              loff_t *offp)
 191 {
 192         struct ubi_volume_desc *desc = file->private_data;
 193         struct ubi_volume *vol = desc->vol;
 194         struct ubi_device *ubi = vol->ubi;
 195         int err, lnum, off, len,  tbuf_size;
 196         size_t count_save = count;
 197         void *tbuf;
 198
 199         dbg_gen("read %zd bytes from offset %lld of volume %d",
 200                 count, *offp, vol->vol_id);
 201
 202         if (vol->updating) {
 203                 dbg_err("updating");
 204                 return -EBUSY;
 205         }
 206         if (vol->upd_marker) {
 207                 dbg_err("damaged volume, update marker is set");
 208                 return -EBADF;
 209         }
 210         if (*offp == vol->used_bytes || count == 0)
 211                 return 0;
 212
 213         if (vol->corrupted)
 214                 dbg_gen("read from corrupted volume %d", vol->vol_id);
 215
 216         if (*offp + count > vol->used_bytes)
 217                 count_save = count = vol->used_bytes - *offp;
 218
 219         tbuf_size = vol->usable_leb_size;
 220         if (count < tbuf_size)
 221                 tbuf_size = ALIGN(count, ubi->min_io_size);
 222         tbuf = vmalloc(tbuf_size);
 223         if (!tbuf)
 224                 return -ENOMEM;
 225
 226         len = count > tbuf_size ? tbuf_size : count;
 227         lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
 228
 229         do {
 230                 cond_resched();
 231
 232                 if (off + len >= vol->usable_leb_size)
 233                         len = vol->usable_leb_size - off;
 234
 235                 err = ubi_eba_read_leb(ubi, vol, lnum, tbuf, off, len, 0);
 236                 if (err)
 237                         break;
 238
 239                 off += len;
 240                 if (off == vol->usable_leb_size) {
 241                         lnum += 1;
 242                         off -= vol->usable_leb_size;
 243                 }
 244
 245                 count -= len;
 246                 *offp += len;
 247
 248                 err = copy_to_user(buf, tbuf, len);
 249                 if (err) {
 250                         err = -EFAULT;
 251                         break;
 252                 }
 253
 254                 buf += len;
 255                 len = count > tbuf_size ? tbuf_size : count;
 256         } while (count);
 257
 258         vfree(tbuf);
 259         return err ? err : count_save - count;
 260 }
 261
 262 /*
 263  * This function allows to directly write to dynamic UBI volumes, without
 264  * issuing the volume update operation.
 265  */
 266 static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
 267                                      size_t count, loff_t *offp)
 268 {
 269         struct ubi_volume_desc *desc = file->private_data;
 270         struct ubi_volume *vol = desc->vol;
 271         struct ubi_device *ubi = vol->ubi;
 272         int lnum, off, len, tbuf_size, err = 0;
 273         size_t count_save = count;
 274         char *tbuf;
 275
 276         if (!vol->direct_writes)
 277                 return -EPERM;
 278
 279         dbg_gen("requested: write %zd bytes to offset %lld of volume %u",
 280                 count, *offp, vol->vol_id);
 281
 282         if (vol->vol_type == UBI_STATIC_VOLUME)
 283                 return -EROFS;
 284
 285         lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
 286         if (off & (ubi->min_io_size - 1)) {
 287                 dbg_err("unaligned position");
 288                 return -EINVAL;
 289         }
 290
 291         if (*offp + count > vol->used_bytes)
 292                 count_save = count = vol->used_bytes - *offp;
 293
 294         /* We can write only in fractions of the minimum I/O unit */
 295         if (count & (ubi->min_io_size - 1)) {
 296                 dbg_err("unaligned write length");
 297                 return -EINVAL;
 298         }
 299
 300         tbuf_size = vol->usable_leb_size;
 301         if (count < tbuf_size)
 302                 tbuf_size = ALIGN(count, ubi->min_io_size);
 303         tbuf = vmalloc(tbuf_size);
 304         if (!tbuf)
 305                 return -ENOMEM;
 306
 307         len = count > tbuf_size ? tbuf_size : count;
 308
 309         while (count) {
 310                 cond_resched();
 311
 312                 if (off + len >= vol->usable_leb_size)
 313                         len = vol->usable_leb_size - off;
 314
 315                 err = copy_from_user(tbuf, buf, len);
 316                 if (err) {
 317                         err = -EFAULT;
 318                         break;
 319                 }
 320
 321                 err = ubi_eba_write_leb(ubi, vol, lnum, tbuf, off, len,
 322                                         UBI_UNKNOWN);
 323                 if (err)
 324                         break;
 325
 326                 off += len;
 327                 if (off == vol->usable_leb_size) {
 328                         lnum += 1;
 329                         off -= vol->usable_leb_size;
 330                 }
 331
 332                 count -= len;
 333                 *offp += len;
 334                 buf += len;
 335                 len = count > tbuf_size ? tbuf_size : count;
 336         }
 337
 338         vfree(tbuf);
 339         return err ? err : count_save - count;
 340 }
 341
 342 static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
 343                               size_t count, loff_t *offp)
 344 {
 345         int err = 0;
 346         struct ubi_volume_desc *desc = file->private_data;
 347         struct ubi_volume *vol = desc->vol;
 348         struct ubi_device *ubi = vol->ubi;
 349
 350         if (!vol->updating && !vol->changing_leb)
 351                 return vol_cdev_direct_write(file, buf, count, offp);
 352
 353         if (vol->updating)
 354                 err = ubi_more_update_data(ubi, vol, buf, count);
 355         else
 356                 err = ubi_more_leb_change_data(ubi, vol, buf, count);
 357
 358         if (err < 0) {
 359                 ubi_err("cannot accept more %zd bytes of data, error %d",
 360                         count, err);
 361                 return err;
 362         }
 363
 364         if (err) {
 365                 /*
 366                  * The operation is finished, @err contains number of actually
 367                  * written bytes.
 368                  */
 369                 count = err;
 370
 371                 if (vol->changing_leb) {
 372                         revoke_exclusive(desc, UBI_READWRITE);
 373                         return count;
 374                 }
 375
 376                 err = ubi_check_volume(ubi, vol->vol_id);
 377                 if (err < 0)
 378                         return err;
 379
 380                 if (err) {
 381                         ubi_warn("volume %d on UBI device %d is corrupted",
 382                                  vol->vol_id, ubi->ubi_num);
 383                         vol->corrupted = 1;
 384                 }
 385                 vol->checked = 1;
 386                 ubi_gluebi_updated(vol);
 387                 revoke_exclusive(desc, UBI_READWRITE);
 388         }
 389
 390         return count;
 391 }
 392
 393 static long vol_cdev_ioctl(struct file *file, unsigned int cmd,
 394                            unsigned long arg)
 395 {
 396         int err = 0;
 397         struct ubi_volume_desc *desc = file->private_data;
 398         struct ubi_volume *vol = desc->vol;
 399         struct ubi_device *ubi = vol->ubi;
 400         void __user *argp = (void __user *)arg;
 401
 402         switch (cmd) {
 403         /* Volume update command */
 404         case UBI_IOCVOLUP:
 405         {
 406                 int64_t bytes, rsvd_bytes;
 407
 408                 if (!capable(CAP_SYS_RESOURCE)) {
 409                         err = -EPERM;
 410                         break;
 411                 }
 412
 413                 err = copy_from_user(&bytes, argp, sizeof(int64_t));
 414                 if (err) {
 415                         err = -EFAULT;
 416                         break;
 417                 }
 418
 419                 if (desc->mode == UBI_READONLY) {
 420                         err = -EROFS;
 421                         break;
 422                 }
 423
 424                 rsvd_bytes = (long long)vol->reserved_pebs *
 425                                         ubi->leb_size-vol->data_pad;
 426                 if (bytes < 0 || bytes > rsvd_bytes) {
 427                         err = -EINVAL;
 428                         break;
 429                 }
 430
 431                 err = get_exclusive(desc);
 432                 if (err < 0)
 433                         break;
 434
 435                 err = ubi_start_update(ubi, vol, bytes);
 436                 if (bytes == 0)
 437                         revoke_exclusive(desc, UBI_READWRITE);
 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 (req.lnum < 0 || req.lnum >= vol->reserved_pebs ||
 462                     req.bytes < 0 || req.lnum >= vol->usable_leb_size)
 463                         break;
 464                 if (req.dtype != UBI_LONGTERM && req.dtype != UBI_SHORTTERM &&
 465                     req.dtype != UBI_UNKNOWN)
 466                         break;
 467
 468                 err = get_exclusive(desc);
 469                 if (err < 0)
 470                         break;
 471
 472                 err = ubi_start_leb_change(ubi, vol, &req);
 473                 if (req.bytes == 0)
 474                         revoke_exclusive(desc, UBI_READWRITE);
 475                 break;
 476         }
 477
 478         /* Logical eraseblock erasure command */
 479         case UBI_IOCEBER:
 480         {
 481                 int32_t lnum;
 482
 483                 err = get_user(lnum, (__user int32_t *)argp);
 484                 if (err) {
 485                         err = -EFAULT;
 486                         break;
 487                 }
 488
 489                 if (desc->mode == UBI_READONLY ||
 490                     vol->vol_type == UBI_STATIC_VOLUME) {
 491                         err = -EROFS;
 492                         break;
 493                 }
 494
 495                 if (lnum < 0 || lnum >= vol->reserved_pebs) {
 496                         err = -EINVAL;
 497                         break;
 498                 }
 499
 500                 dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
 501                 err = ubi_eba_unmap_leb(ubi, vol, lnum);
 502                 if (err)
 503                         break;
 504
 505                 err = ubi_wl_flush(ubi);
 506                 break;
 507         }
 508
 509         /* Logical eraseblock map command */
 510         case UBI_IOCEBMAP:
 511         {
 512                 struct ubi_map_req req;
 513
 514                 err = copy_from_user(&req, argp, sizeof(struct ubi_map_req));
 515                 if (err) {
 516                         err = -EFAULT;
 517                         break;
 518                 }
 519                 err = ubi_leb_map(desc, req.lnum, req.dtype);
 520                 break;
 521         }
 522
 523         /* Logical eraseblock un-map command */
 524         case UBI_IOCEBUNMAP:
 525         {
 526                 int32_t lnum;
 527
 528                 err = get_user(lnum, (__user int32_t *)argp);
 529                 if (err) {
 530                         err = -EFAULT;
 531                         break;
 532                 }
 533                 err = ubi_leb_unmap(desc, lnum);
 534                 break;
 535         }
 536
 537         /* Check if logical eraseblock is mapped command */
 538         case UBI_IOCEBISMAP:
 539         {
 540                 int32_t lnum;
 541
 542                 err = get_user(lnum, (__user int32_t *)argp);
 543                 if (err) {
 544                         err = -EFAULT;
 545                         break;
 546                 }
 547                 err = ubi_is_mapped(desc, lnum);
 548                 break;
 549         }
 550
 551         /* Set volume property command*/
 552         case UBI_IOCSETPROP:
 553         {
 554                 struct ubi_set_prop_req req;
 555
 556                 err = copy_from_user(&req, argp,
 557                                 sizeof(struct ubi_set_prop_req));
 558                 if (err) {
 559                         err = -EFAULT;
 560                         break;
 561                 }
 562                 switch (req.property) {
 563                 case UBI_PROP_DIRECT_WRITE:
 564                         mutex_lock(&ubi->volumes_mutex);
 565                         desc->vol->direct_writes = !!req.value;
 566                         mutex_unlock(&ubi->volumes_mutex);
 567                         break;
 568                 default:
 569                         err = -EINVAL;
 570                         break;
 571                 }
 572                 break;
 573         }
 574
 575         default:
 576                 err = -ENOTTY;
 577                 break;
 578         }
 579         return err;
 580 }
 581
 582 /**
 583  * verify_mkvol_req - verify volume creation request.
 584  * @ubi: UBI device description object
 585  * @req: the request to check
 586  *
 587  * This function zero if the request is correct, and %-EINVAL if not.
 588  */
 589 static int verify_mkvol_req(const struct ubi_device *ubi,
 590                             const struct ubi_mkvol_req *req)
 591 {
 592         int n, err = -EINVAL;
 593
 594         if (req->bytes < 0 || req->alignment < 0 || req->vol_type < 0 ||
 595             req->name_len < 0)
 596                 goto bad;
 597
 598         if ((req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) &&
 599             req->vol_id != UBI_VOL_NUM_AUTO)
 600                 goto bad;
 601
 602         if (req->alignment == 0)
 603                 goto bad;
 604
 605         if (req->bytes == 0)
 606                 goto bad;
 607
 608         if (req->vol_type != UBI_DYNAMIC_VOLUME &&
 609             req->vol_type != UBI_STATIC_VOLUME)
 610                 goto bad;
 611
 612         if (req->alignment > ubi->leb_size)
 613                 goto bad;
 614
 615         n = req->alignment & (ubi->min_io_size - 1);
 616         if (req->alignment != 1 && n)
 617                 goto bad;
 618
 619         if (req->name_len > UBI_VOL_NAME_MAX) {
 620                 err = -ENAMETOOLONG;
 621                 goto bad;
 622         }
 623
 624         n = strnlen(req->name, req->name_len + 1);
 625         if (n != req->name_len)
 626                 goto bad;
 627
 628         return 0;
 629
 630 bad:
 631         dbg_err("bad volume creation request");
 632         ubi_dbg_dump_mkvol_req(req);
 633         return err;
 634 }
 635
 636 /**
 637  * verify_rsvol_req - verify volume re-size request.
 638  * @ubi: UBI device description object
 639  * @req: the request to check
 640  *
 641  * This function returns zero if the request is correct, and %-EINVAL if not.
 642  */
 643 static int verify_rsvol_req(const struct ubi_device *ubi,
 644                             const struct ubi_rsvol_req *req)
 645 {
 646         if (req->bytes <= 0)
 647                 return -EINVAL;
 648
 649         if (req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots)
 650                 return -EINVAL;
 651
 652         return 0;
 653 }
 654
 655 /**
 656  * rename_volumes - rename UBI volumes.
 657  * @ubi: UBI device description object
 658  * @req: volumes re-name request
 659  *
 660  * This is a helper function for the volume re-name IOCTL which validates the
 661  * the request, opens the volume and calls corresponding volumes management
 662  * function. Returns zero in case of success and a negative error code in case
 663  * of failure.
 664  */
 665 static int rename_volumes(struct ubi_device *ubi,
 666                           struct ubi_rnvol_req *req)
 667 {
 668         int i, n, err;
 669         struct list_head rename_list;
 670         struct ubi_rename_entry *re, *re1;
 671
 672         if (req->count < 0 || req->count > UBI_MAX_RNVOL)
 673                 return -EINVAL;
 674
 675         if (req->count == 0)
 676                 return 0;
 677
 678         /* Validate volume IDs and names in the request */
 679         for (i = 0; i < req->count; i++) {
 680                 if (req->ents[i].vol_id < 0 ||
 681                     req->ents[i].vol_id >= ubi->vtbl_slots)
 682                         return -EINVAL;
 683                 if (req->ents[i].name_len < 0)
 684                         return -EINVAL;
 685                 if (req->ents[i].name_len > UBI_VOL_NAME_MAX)
 686                         return -ENAMETOOLONG;
 687                 req->ents[i].name[req->ents[i].name_len] = '\0';
 688                 n = strlen(req->ents[i].name);
 689                 if (n != req->ents[i].name_len)
 690                         err = -EINVAL;
 691         }
 692
 693         /* Make sure volume IDs and names are unique */
 694         for (i = 0; i < req->count - 1; i++) {
 695                 for (n = i + 1; n < req->count; n++) {
 696                         if (req->ents[i].vol_id == req->ents[n].vol_id) {
 697                                 dbg_err("duplicated volume id %d",
 698                                         req->ents[i].vol_id);
 699                                 return -EINVAL;
 700                         }
 701                         if (!strcmp(req->ents[i].name, req->ents[n].name)) {
 702                                 dbg_err("duplicated volume name \"%s\"",
 703                                         req->ents[i].name);
 704                                 return -EINVAL;
 705                         }
 706                 }
 707         }
 708
 709         /* Create the re-name list */
 710         INIT_LIST_HEAD(&rename_list);
 711         for (i = 0; i < req->count; i++) {
 712                 int vol_id = req->ents[i].vol_id;
 713                 int name_len = req->ents[i].name_len;
 714                 const char *name = req->ents[i].name;
 715
 716                 re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
 717                 if (!re) {
 718                         err = -ENOMEM;
 719                         goto out_free;
 720                 }
 721
 722                 re->desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
 723                 if (IS_ERR(re->desc)) {
 724                         err = PTR_ERR(re->desc);
 725                         dbg_err("cannot open volume %d, error %d", vol_id, err);
 726                         kfree(re);
 727                         goto out_free;
 728                 }
 729
 730                 /* Skip this re-naming if the name does not really change */
 731                 if (re->desc->vol->name_len == name_len &&
 732                     !memcmp(re->desc->vol->name, name, name_len)) {
 733                         ubi_close_volume(re->desc);
 734                         kfree(re);
 735                         continue;
 736                 }
 737
 738                 re->new_name_len = name_len;
 739                 memcpy(re->new_name, name, name_len);
 740                 list_add_tail(&re->list, &rename_list);
 741                 dbg_msg("will rename volume %d from \"%s\" to \"%s\"",
 742                         vol_id, re->desc->vol->name, name);
 743         }
 744
 745         if (list_empty(&rename_list))
 746                 return 0;
 747
 748         /* Find out the volumes which have to be removed */
 749         list_for_each_entry(re, &rename_list, list) {
 750                 struct ubi_volume_desc *desc;
 751                 int no_remove_needed = 0;
 752
 753                 /*
 754                  * Volume @re->vol_id is going to be re-named to
 755                  * @re->new_name, while its current name is @name. If a volume
 756                  * with name @re->new_name currently exists, it has to be
 757                  * removed, unless it is also re-named in the request (@req).
 758                  */
 759                 list_for_each_entry(re1, &rename_list, list) {
 760                         if (re->new_name_len == re1->desc->vol->name_len &&
 761                             !memcmp(re->new_name, re1->desc->vol->name,
 762                                     re1->desc->vol->name_len)) {
 763                                 no_remove_needed = 1;
 764                                 break;
 765                         }
 766                 }
 767
 768                 if (no_remove_needed)
 769                         continue;
 770
 771                 /*
 772                  * It seems we need to remove volume with name @re->new_name,
 773                  * if it exists.
 774                  */
 775                 desc = ubi_open_volume_nm(ubi->ubi_num, re->new_name,
 776                                           UBI_EXCLUSIVE);
 777                 if (IS_ERR(desc)) {
 778                         err = PTR_ERR(desc);
 779                         if (err == -ENODEV)
 780                                 /* Re-naming into a non-existing volume name */
 781                                 continue;
 782
 783                         /* The volume exists but busy, or an error occurred */
 784                         dbg_err("cannot open volume \"%s\", error %d",
 785                                 re->new_name, err);
 786                         goto out_free;
 787                 }
 788
 789                 re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
 790                 if (!re) {
 791                         err = -ENOMEM;
 792                         ubi_close_volume(desc);
 793                         goto out_free;
 794                 }
 795
 796                 re->remove = 1;
 797                 re->desc = desc;
 798                 list_add(&re->list, &rename_list);
 799                 dbg_msg("will remove volume %d, name \"%s\"",
 800                         re->desc->vol->vol_id, re->desc->vol->name);
 801         }
 802
 803         mutex_lock(&ubi->volumes_mutex);
 804         err = ubi_rename_volumes(ubi, &rename_list);
 805         mutex_unlock(&ubi->volumes_mutex);
 806
 807 out_free:
 808         list_for_each_entry_safe(re, re1, &rename_list, list) {
 809                 ubi_close_volume(re->desc);
 810                 list_del(&re->list);
 811                 kfree(re);
 812         }
 813         return err;
 814 }
 815
 816 static long ubi_cdev_ioctl(struct file *file, unsigned int cmd,
 817                            unsigned long arg)
 818 {
 819         int err = 0;
 820         struct ubi_device *ubi;
 821         struct ubi_volume_desc *desc;
 822         void __user *argp = (void __user *)arg;
 823
 824         if (!capable(CAP_SYS_RESOURCE))
 825                 return -EPERM;
 826
 827         ubi = ubi_get_by_major(imajor(file->f_mapping->host));
 828         if (!ubi)
 829                 return -ENODEV;
 830
 831         switch (cmd) {
 832         /* Create volume command */
 833         case UBI_IOCMKVOL:
 834         {
 835                 struct ubi_mkvol_req req;
 836
 837                 dbg_gen("create volume");
 838                 err = copy_from_user(&req, argp, sizeof(struct ubi_mkvol_req));
 839                 if (err) {
 840                         err = -EFAULT;
 841                         break;
 842                 }
 843
 844                 req.name[req.name_len] = '\0';
 845                 err = verify_mkvol_req(ubi, &req);
 846                 if (err)
 847                         break;
 848
 849                 mutex_lock(&ubi->volumes_mutex);
 850                 err = ubi_create_volume(ubi, &req);
 851                 mutex_unlock(&ubi->volumes_mutex);
 852                 if (err)
 853                         break;
 854
 855                 err = put_user(req.vol_id, (__user int32_t *)argp);
 856                 if (err)
 857                         err = -EFAULT;
 858
 859                 break;
 860         }
 861
 862         /* Remove volume command */
 863         case UBI_IOCRMVOL:
 864         {
 865                 int vol_id;
 866
 867                 dbg_gen("remove volume");
 868                 err = get_user(vol_id, (__user int32_t *)argp);
 869                 if (err) {
 870                         err = -EFAULT;
 871                         break;
 872                 }
 873
 874                 desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
 875                 if (IS_ERR(desc)) {
 876                         err = PTR_ERR(desc);
 877                         break;
 878                 }
 879
 880                 mutex_lock(&ubi->volumes_mutex);
 881                 err = ubi_remove_volume(desc, 0);
 882                 mutex_unlock(&ubi->volumes_mutex);
 883
 884                 /*
 885                  * The volume is deleted (unless an error occurred), and the
 886                  * 'struct ubi_volume' object will be freed when
 887                  * 'ubi_close_volume()' will call 'put_device()'.
 888                  */
 889                 ubi_close_volume(desc);
 890                 break;
 891         }
 892
 893         /* Re-size volume command */
 894         case UBI_IOCRSVOL:
 895         {
 896                 int pebs;
 897                 struct ubi_rsvol_req req;
 898
 899                 dbg_gen("re-size volume");
 900                 err = copy_from_user(&req, argp, sizeof(struct ubi_rsvol_req));
 901                 if (err) {
 902                         err = -EFAULT;
 903                         break;
 904                 }
 905
 906                 err = verify_rsvol_req(ubi, &req);
 907                 if (err)
 908                         break;
 909
 910                 desc = ubi_open_volume(ubi->ubi_num, req.vol_id, UBI_EXCLUSIVE);
 911                 if (IS_ERR(desc)) {
 912                         err = PTR_ERR(desc);
 913                         break;
 914                 }
 915
 916                 pebs = div_u64(req.bytes + desc->vol->usable_leb_size - 1,
 917                                desc->vol->usable_leb_size);
 918
 919                 mutex_lock(&ubi->volumes_mutex);
 920                 err = ubi_resize_volume(desc, pebs);
 921                 mutex_unlock(&ubi->volumes_mutex);
 922                 ubi_close_volume(desc);
 923                 break;
 924         }
 925
 926         /* Re-name volumes command */
 927         case UBI_IOCRNVOL:
 928         {
 929                 struct ubi_rnvol_req *req;
 930
 931                 dbg_msg("re-name volumes");
 932                 req = kmalloc(sizeof(struct ubi_rnvol_req), GFP_KERNEL);
 933                 if (!req) {
 934                         err = -ENOMEM;
 935                         break;
 936                 };
 937
 938                 err = copy_from_user(req, argp, sizeof(struct ubi_rnvol_req));
 939                 if (err) {
 940                         err = -EFAULT;
 941                         kfree(req);
 942                         break;
 943                 }
 944
 945                 mutex_lock(&ubi->mult_mutex);
 946                 err = rename_volumes(ubi, req);
 947                 mutex_unlock(&ubi->mult_mutex);
 948                 kfree(req);
 949                 break;
 950         }
 951
 952         default:
 953                 err = -ENOTTY;
 954                 break;
 955         }
 956
 957         ubi_put_device(ubi);
 958         return err;
 959 }
 960
 961 static long ctrl_cdev_ioctl(struct file *file, unsigned int cmd,
 962                             unsigned long arg)
 963 {
 964         int err = 0;
 965         void __user *argp = (void __user *)arg;
 966
 967         if (!capable(CAP_SYS_RESOURCE))
 968                 return -EPERM;
 969
 970         switch (cmd) {
 971         /* Attach an MTD device command */
 972         case UBI_IOCATT:
 973         {
 974                 struct ubi_attach_req req;
 975                 struct mtd_info *mtd;
 976
 977                 dbg_gen("attach MTD device");
 978                 err = copy_from_user(&req, argp, sizeof(struct ubi_attach_req));
 979                 if (err) {
 980                         err = -EFAULT;
 981                         break;
 982                 }
 983
 984                 if (req.mtd_num < 0 ||
 985                     (req.ubi_num < 0 && req.ubi_num != UBI_DEV_NUM_AUTO)) {
 986                         err = -EINVAL;
 987                         break;
 988                 }
 989
 990                 mtd = get_mtd_device(NULL, req.mtd_num);
 991                 if (IS_ERR(mtd)) {
 992                         err = PTR_ERR(mtd);
 993                         break;
 994                 }
 995
 996                 /*
 997                  * Note, further request verification is done by
 998                  * 'ubi_attach_mtd_dev()'.
 999                  */
1000                 mutex_lock(&ubi_devices_mutex);
1001                 err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset);
1002                 mutex_unlock(&ubi_devices_mutex);
1003                 if (err < 0)
1004                         put_mtd_device(mtd);
1005                 else
1006                         /* @err contains UBI device number */
1007                         err = put_user(err, (__user int32_t *)argp);
1008
1009                 break;
1010         }
1011
1012         /* Detach an MTD device command */
1013         case UBI_IOCDET:
1014         {
1015                 int ubi_num;
1016
1017                 dbg_gen("dettach MTD device");
1018                 err = get_user(ubi_num, (__user int32_t *)argp);
1019                 if (err) {
1020                         err = -EFAULT;
1021                         break;
1022                 }
1023
1024                 mutex_lock(&ubi_devices_mutex);
1025                 err = ubi_detach_mtd_dev(ubi_num, 0);
1026                 mutex_unlock(&ubi_devices_mutex);
1027                 break;
1028         }
1029
1030         default:
1031                 err = -ENOTTY;
1032                 break;
1033         }
1034
1035         return err;
1036 }
1037
1038 #ifdef CONFIG_COMPAT
1039 static long vol_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1040                                   unsigned long arg)
1041 {
1042         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1043
1044         return vol_cdev_ioctl(file, cmd, translated_arg);
1045 }
1046
1047 static long ubi_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1048                                   unsigned long arg)
1049 {
1050         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1051
1052         return ubi_cdev_ioctl(file, cmd, translated_arg);
1053 }
1054
1055 static long ctrl_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1056                                    unsigned long arg)
1057 {
1058         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1059
1060         return ctrl_cdev_ioctl(file, cmd, translated_arg);
1061 }
1062 #else
1063 #define vol_cdev_compat_ioctl  NULL
1064 #define ubi_cdev_compat_ioctl  NULL
1065 #define ctrl_cdev_compat_ioctl NULL
1066 #endif
1067
1068 /* UBI volume character device operations */
1069 const struct file_operations ubi_vol_cdev_operations = {
1070         .owner          = THIS_MODULE,
1071         .open           = vol_cdev_open,
1072         .release        = vol_cdev_release,
1073         .llseek         = vol_cdev_llseek,
1074         .read           = vol_cdev_read,
1075         .write          = vol_cdev_write,
1076         .unlocked_ioctl = vol_cdev_ioctl,
1077         .compat_ioctl   = vol_cdev_compat_ioctl,
1078 };
1079
1080 /* UBI character device operations */
1081 const struct file_operations ubi_cdev_operations = {
1082         .owner          = THIS_MODULE,
1083         .llseek         = no_llseek,
1084         .unlocked_ioctl = ubi_cdev_ioctl,
1085         .compat_ioctl   = ubi_cdev_compat_ioctl,
1086 };
1087
1088 /* UBI control character device operations */
1089 const struct file_operations ubi_ctrl_cdev_operations = {
1090         .owner          = THIS_MODULE,
1091         .unlocked_ioctl = ctrl_cdev_ioctl,
1092         .compat_ioctl   = ctrl_cdev_compat_ioctl,
1093 };