Pileus Git - ~andy/linux/blob - 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 <mtd/ubi-user.h>
  44 #include <asm/div64.h>
  45 #include "ubi.h"
  46
  47 /**
  48  * get_exclusive - get exclusive access to an UBI volume.
  49  * @desc: volume descriptor
  50  *
  51  * This function changes UBI volume open mode to "exclusive". Returns previous
  52  * mode value (positive integer) in case of success and a negative error code
  53  * in case of failure.
  54  */
  55 static int get_exclusive(struct ubi_volume_desc *desc)
  56 {
  57         int users, err;
  58         struct ubi_volume *vol = desc->vol;
  59
  60         spin_lock(&vol->ubi->volumes_lock);
  61         users = vol->readers + vol->writers + vol->exclusive;
  62         ubi_assert(users > 0);
  63         if (users > 1) {
  64                 dbg_err("%d users for volume %d", users, vol->vol_id);
  65                 err = -EBUSY;
  66         } else {
  67                 vol->readers = vol->writers = 0;
  68                 vol->exclusive = 1;
  69                 err = desc->mode;
  70                 desc->mode = UBI_EXCLUSIVE;
  71         }
  72         spin_unlock(&vol->ubi->volumes_lock);
  73
  74         return err;
  75 }
  76
  77 /**
  78  * revoke_exclusive - revoke exclusive mode.
  79  * @desc: volume descriptor
  80  * @mode: new mode to switch to
  81  */
  82 static void revoke_exclusive(struct ubi_volume_desc *desc, int mode)
  83 {
  84         struct ubi_volume *vol = desc->vol;
  85
  86         spin_lock(&vol->ubi->volumes_lock);
  87         ubi_assert(vol->readers == 0 && vol->writers == 0);
  88         ubi_assert(vol->exclusive == 1 && desc->mode == UBI_EXCLUSIVE);
  89         vol->exclusive = 0;
  90         if (mode == UBI_READONLY)
  91                 vol->readers = 1;
  92         else if (mode == UBI_READWRITE)
  93                 vol->writers = 1;
  94         else
  95                 vol->exclusive = 1;
  96         spin_unlock(&vol->ubi->volumes_lock);
  97
  98         desc->mode = mode;
  99 }
 100
 101 static int vol_cdev_open(struct inode *inode, struct file *file)
 102 {
 103         struct ubi_volume_desc *desc;
 104         int vol_id = iminor(inode) - 1, mode, ubi_num;
 105
 106         ubi_num = ubi_major2num(imajor(inode));
 107         if (ubi_num < 0)
 108                 return ubi_num;
 109
 110         if (file->f_mode & FMODE_WRITE)
 111                 mode = UBI_READWRITE;
 112         else
 113                 mode = UBI_READONLY;
 114
 115         dbg_gen("open volume %d, mode %d", vol_id, mode);
 116
 117         desc = ubi_open_volume(ubi_num, vol_id, mode);
 118         if (IS_ERR(desc))
 119                 return PTR_ERR(desc);
 120
 121         file->private_data = desc;
 122         return 0;
 123 }
 124
 125 static int vol_cdev_release(struct inode *inode, struct file *file)
 126 {
 127         struct ubi_volume_desc *desc = file->private_data;
 128         struct ubi_volume *vol = desc->vol;
 129
 130         dbg_gen("release volume %d, mode %d", vol->vol_id, desc->mode);
 131
 132         if (vol->updating) {
 133                 ubi_warn("update of volume %d not finished, volume is damaged",
 134                          vol->vol_id);
 135                 ubi_assert(!vol->changing_leb);
 136                 vol->updating = 0;
 137                 vfree(vol->upd_buf);
 138         } else if (vol->changing_leb) {
 139                 dbg_gen("only %lld of %lld bytes received for atomic LEB change"
 140                         " for volume %d:%d, cancel", vol->upd_received,
 141                         vol->upd_bytes, vol->ubi->ubi_num, vol->vol_id);
 142                 vol->changing_leb = 0;
 143                 vfree(vol->upd_buf);
 144         }
 145
 146         ubi_close_volume(desc);
 147         return 0;
 148 }
 149
 150 static loff_t vol_cdev_llseek(struct file *file, loff_t offset, int origin)
 151 {
 152         struct ubi_volume_desc *desc = file->private_data;
 153         struct ubi_volume *vol = desc->vol;
 154         loff_t new_offset;
 155
 156         if (vol->updating) {
 157                  /* Update is in progress, seeking is prohibited */
 158                 dbg_err("updating");
 159                 return -EBUSY;
 160         }
 161
 162         switch (origin) {
 163         case 0: /* SEEK_SET */
 164                 new_offset = offset;
 165                 break;
 166         case 1: /* SEEK_CUR */
 167                 new_offset = file->f_pos + offset;
 168                 break;
 169         case 2: /* SEEK_END */
 170                 new_offset = vol->used_bytes + offset;
 171                 break;
 172         default:
 173                 return -EINVAL;
 174         }
 175
 176         if (new_offset < 0 || new_offset > vol->used_bytes) {
 177                 dbg_err("bad seek %lld", new_offset);
 178                 return -EINVAL;
 179         }
 180
 181         dbg_gen("seek volume %d, offset %lld, origin %d, new offset %lld",
 182                 vol->vol_id, offset, origin, new_offset);
 183
 184         file->f_pos = new_offset;
 185         return new_offset;
 186 }
 187
 188 static ssize_t vol_cdev_read(struct file *file, __user char *buf, size_t count,
 189                              loff_t *offp)
 190 {
 191         struct ubi_volume_desc *desc = file->private_data;
 192         struct ubi_volume *vol = desc->vol;
 193         struct ubi_device *ubi = vol->ubi;
 194         int err, lnum, off, len,  tbuf_size;
 195         size_t count_save = count;
 196         void *tbuf;
 197         uint64_t tmp;
 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
 228         tmp = *offp;
 229         off = do_div(tmp, vol->usable_leb_size);
 230         lnum = tmp;
 231
 232         do {
 233                 cond_resched();
 234
 235                 if (off + len >= vol->usable_leb_size)
 236                         len = vol->usable_leb_size - off;
 237
 238                 err = ubi_eba_read_leb(ubi, vol, lnum, tbuf, off, len, 0);
 239                 if (err)
 240                         break;
 241
 242                 off += len;
 243                 if (off == vol->usable_leb_size) {
 244                         lnum += 1;
 245                         off -= vol->usable_leb_size;
 246                 }
 247
 248                 count -= len;
 249                 *offp += len;
 250
 251                 err = copy_to_user(buf, tbuf, len);
 252                 if (err) {
 253                         err = -EFAULT;
 254                         break;
 255                 }
 256
 257                 buf += len;
 258                 len = count > tbuf_size ? tbuf_size : count;
 259         } while (count);
 260
 261         vfree(tbuf);
 262         return err ? err : count_save - count;
 263 }
 264
 265 #ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
 266
 267 /*
 268  * This function allows to directly write to dynamic UBI volumes, without
 269  * issuing the volume update operation. Available only as a debugging feature.
 270  * Very useful for testing UBI.
 271  */
 272 static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
 273                                      size_t count, loff_t *offp)
 274 {
 275         struct ubi_volume_desc *desc = file->private_data;
 276         struct ubi_volume *vol = desc->vol;
 277         struct ubi_device *ubi = vol->ubi;
 278         int lnum, off, len, tbuf_size, err = 0;
 279         size_t count_save = count;
 280         char *tbuf;
 281         uint64_t tmp;
 282
 283         dbg_gen("requested: write %zd bytes to offset %lld of volume %u",
 284                 count, *offp, vol->vol_id);
 285
 286         if (vol->vol_type == UBI_STATIC_VOLUME)
 287                 return -EROFS;
 288
 289         tmp = *offp;
 290         off = do_div(tmp, vol->usable_leb_size);
 291         lnum = tmp;
 292
 293         if (off & (ubi->min_io_size - 1)) {
 294                 dbg_err("unaligned position");
 295                 return -EINVAL;
 296         }
 297
 298         if (*offp + count > vol->used_bytes)
 299                 count_save = count = vol->used_bytes - *offp;
 300
 301         /* We can write only in fractions of the minimum I/O unit */
 302         if (count & (ubi->min_io_size - 1)) {
 303                 dbg_err("unaligned write length");
 304                 return -EINVAL;
 305         }
 306
 307         tbuf_size = vol->usable_leb_size;
 308         if (count < tbuf_size)
 309                 tbuf_size = ALIGN(count, ubi->min_io_size);
 310         tbuf = vmalloc(tbuf_size);
 311         if (!tbuf)
 312                 return -ENOMEM;
 313
 314         len = count > tbuf_size ? tbuf_size : count;
 315
 316         while (count) {
 317                 cond_resched();
 318
 319                 if (off + len >= vol->usable_leb_size)
 320                         len = vol->usable_leb_size - off;
 321
 322                 err = copy_from_user(tbuf, buf, len);
 323                 if (err) {
 324                         err = -EFAULT;
 325                         break;
 326                 }
 327
 328                 err = ubi_eba_write_leb(ubi, vol, lnum, tbuf, off, len,
 329                                         UBI_UNKNOWN);
 330                 if (err)
 331                         break;
 332
 333                 off += len;
 334                 if (off == vol->usable_leb_size) {
 335                         lnum += 1;
 336                         off -= vol->usable_leb_size;
 337                 }
 338
 339                 count -= len;
 340                 *offp += len;
 341                 buf += len;
 342                 len = count > tbuf_size ? tbuf_size : count;
 343         }
 344
 345         vfree(tbuf);
 346         return err ? err : count_save - count;
 347 }
 348
 349 #else
 350 #define vol_cdev_direct_write(file, buf, count, offp) (-EPERM)
 351 #endif /* CONFIG_MTD_UBI_DEBUG_USERSPACE_IO */
 352
 353 static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
 354                               size_t count, loff_t *offp)
 355 {
 356         int err = 0;
 357         struct ubi_volume_desc *desc = file->private_data;
 358         struct ubi_volume *vol = desc->vol;
 359         struct ubi_device *ubi = vol->ubi;
 360
 361         if (!vol->updating && !vol->changing_leb)
 362                 return vol_cdev_direct_write(file, buf, count, offp);
 363
 364         if (vol->updating)
 365                 err = ubi_more_update_data(ubi, vol, buf, count);
 366         else
 367                 err = ubi_more_leb_change_data(ubi, vol, buf, count);
 368
 369         if (err < 0) {
 370                 ubi_err("cannot accept more %zd bytes of data, error %d",
 371                         count, err);
 372                 return err;
 373         }
 374
 375         if (err) {
 376                 /*
 377                  * The operation is finished, @err contains number of actually
 378                  * written bytes.
 379                  */
 380                 count = err;
 381
 382                 if (vol->changing_leb) {
 383                         revoke_exclusive(desc, UBI_READWRITE);
 384                         return count;
 385                 }
 386
 387                 err = ubi_check_volume(ubi, vol->vol_id);
 388                 if (err < 0)
 389                         return err;
 390
 391                 if (err) {
 392                         ubi_warn("volume %d on UBI device %d is corrupted",
 393                                  vol->vol_id, ubi->ubi_num);
 394                         vol->corrupted = 1;
 395                 }
 396                 vol->checked = 1;
 397                 ubi_gluebi_updated(vol);
 398                 revoke_exclusive(desc, UBI_READWRITE);
 399         }
 400
 401         return count;
 402 }
 403
 404 static int vol_cdev_ioctl(struct inode *inode, struct file *file,
 405                           unsigned int cmd, unsigned long arg)
 406 {
 407         int err = 0;
 408         struct ubi_volume_desc *desc = file->private_data;
 409         struct ubi_volume *vol = desc->vol;
 410         struct ubi_device *ubi = vol->ubi;
 411         void __user *argp = (void __user *)arg;
 412
 413         switch (cmd) {
 414         /* Volume update command */
 415         case UBI_IOCVOLUP:
 416         {
 417                 int64_t bytes, rsvd_bytes;
 418
 419                 if (!capable(CAP_SYS_RESOURCE)) {
 420                         err = -EPERM;
 421                         break;
 422                 }
 423
 424                 err = copy_from_user(&bytes, argp, sizeof(int64_t));
 425                 if (err) {
 426                         err = -EFAULT;
 427                         break;
 428                 }
 429
 430                 if (desc->mode == UBI_READONLY) {
 431                         err = -EROFS;
 432                         break;
 433                 }
 434
 435                 rsvd_bytes = (long long)vol->reserved_pebs *
 436                                         ubi->leb_size-vol->data_pad;
 437                 if (bytes < 0 || bytes > rsvd_bytes) {
 438                         err = -EINVAL;
 439                         break;
 440                 }
 441
 442                 err = get_exclusive(desc);
 443                 if (err < 0)
 444                         break;
 445
 446                 err = ubi_start_update(ubi, vol, bytes);
 447                 if (bytes == 0)
 448                         revoke_exclusive(desc, UBI_READWRITE);
 449                 break;
 450         }
 451
 452         /* Atomic logical eraseblock change command */
 453         case UBI_IOCEBCH:
 454         {
 455                 struct ubi_leb_change_req req;
 456
 457                 err = copy_from_user(&req, argp,
 458                                      sizeof(struct ubi_leb_change_req));
 459                 if (err) {
 460                         err = -EFAULT;
 461                         break;
 462                 }
 463
 464                 if (desc->mode == UBI_READONLY ||
 465                     vol->vol_type == UBI_STATIC_VOLUME) {
 466                         err = -EROFS;
 467                         break;
 468                 }
 469
 470                 /* Validate the request */
 471                 err = -EINVAL;
 472                 if (req.lnum < 0 || req.lnum >= vol->reserved_pebs ||
 473                     req.bytes < 0 || req.lnum >= vol->usable_leb_size)
 474                         break;
 475                 if (req.dtype != UBI_LONGTERM && req.dtype != UBI_SHORTTERM &&
 476                     req.dtype != UBI_UNKNOWN)
 477                         break;
 478
 479                 err = get_exclusive(desc);
 480                 if (err < 0)
 481                         break;
 482
 483                 err = ubi_start_leb_change(ubi, vol, &req);
 484                 if (req.bytes == 0)
 485                         revoke_exclusive(desc, UBI_READWRITE);
 486                 break;
 487         }
 488
 489 #ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
 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);
 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, req.dtype);
 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 #endif
 563
 564         default:
 565                 err = -ENOTTY;
 566                 break;
 567         }
 568         return err;
 569 }
 570
 571 /**
 572  * verify_mkvol_req - verify volume creation request.
 573  * @ubi: UBI device description object
 574  * @req: the request to check
 575  *
 576  * This function zero if the request is correct, and %-EINVAL if not.
 577  */
 578 static int verify_mkvol_req(const struct ubi_device *ubi,
 579                             const struct ubi_mkvol_req *req)
 580 {
 581         int n, err = -EINVAL;
 582
 583         if (req->bytes < 0 || req->alignment < 0 || req->vol_type < 0 ||
 584             req->name_len < 0)
 585                 goto bad;
 586
 587         if ((req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) &&
 588             req->vol_id != UBI_VOL_NUM_AUTO)
 589                 goto bad;
 590
 591         if (req->alignment == 0)
 592                 goto bad;
 593
 594         if (req->bytes == 0)
 595                 goto bad;
 596
 597         if (req->vol_type != UBI_DYNAMIC_VOLUME &&
 598             req->vol_type != UBI_STATIC_VOLUME)
 599                 goto bad;
 600
 601         if (req->alignment > ubi->leb_size)
 602                 goto bad;
 603
 604         n = req->alignment & (ubi->min_io_size - 1);
 605         if (req->alignment != 1 && n)
 606                 goto bad;
 607
 608         if (req->name_len > UBI_VOL_NAME_MAX) {
 609                 err = -ENAMETOOLONG;
 610                 goto bad;
 611         }
 612
 613         n = strnlen(req->name, req->name_len + 1);
 614         if (n != req->name_len)
 615                 goto bad;
 616
 617         return 0;
 618
 619 bad:
 620         dbg_err("bad volume creation request");
 621         ubi_dbg_dump_mkvol_req(req);
 622         return err;
 623 }
 624
 625 /**
 626  * verify_rsvol_req - verify volume re-size request.
 627  * @ubi: UBI device description object
 628  * @req: the request to check
 629  *
 630  * This function returns zero if the request is correct, and %-EINVAL if not.
 631  */
 632 static int verify_rsvol_req(const struct ubi_device *ubi,
 633                             const struct ubi_rsvol_req *req)
 634 {
 635         if (req->bytes <= 0)
 636                 return -EINVAL;
 637
 638         if (req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots)
 639                 return -EINVAL;
 640
 641         return 0;
 642 }
 643
 644 /**
 645  * rename_volumes - rename UBI volumes.
 646  * @ubi: UBI device description object
 647  * @req: volumes re-name request
 648  *
 649  * This is a helper function for the volume re-name IOCTL which validates the
 650  * the request, opens the volume and calls corresponding volumes management
 651  * function. Returns zero in case of success and a negative error code in case
 652  * of failure.
 653  */
 654 static int rename_volumes(struct ubi_device *ubi,
 655                           struct ubi_rnvol_req *req)
 656 {
 657         int i, n, err;
 658         struct list_head rename_list;
 659         struct ubi_rename_entry *re, *re1;
 660
 661         if (req->count < 0 || req->count > UBI_MAX_RNVOL)
 662                 return -EINVAL;
 663
 664         if (req->count == 0)
 665                 return 0;
 666
 667         /* Validate volume IDs and names in the request */
 668         for (i = 0; i < req->count; i++) {
 669                 if (req->ents[i].vol_id < 0 ||
 670                     req->ents[i].vol_id >= ubi->vtbl_slots)
 671                         return -EINVAL;
 672                 if (req->ents[i].name_len < 0)
 673                         return -EINVAL;
 674                 if (req->ents[i].name_len > UBI_VOL_NAME_MAX)
 675                         return -ENAMETOOLONG;
 676                 req->ents[i].name[req->ents[i].name_len] = '\0';
 677                 n = strlen(req->ents[i].name);
 678                 if (n != req->ents[i].name_len)
 679                         err = -EINVAL;
 680         }
 681
 682         /* Make sure volume IDs and names are unique */
 683         for (i = 0; i < req->count - 1; i++) {
 684                 for (n = i + 1; n < req->count; n++) {
 685                         if (req->ents[i].vol_id == req->ents[n].vol_id) {
 686                                 dbg_err("duplicated volume id %d",
 687                                         req->ents[i].vol_id);
 688                                 return -EINVAL;
 689                         }
 690                         if (!strcmp(req->ents[i].name, req->ents[n].name)) {
 691                                 dbg_err("duplicated volume name \"%s\"",
 692                                         req->ents[i].name);
 693                                 return -EINVAL;
 694                         }
 695                 }
 696         }
 697
 698         /* Create the re-name list */
 699         INIT_LIST_HEAD(&rename_list);
 700         for (i = 0; i < req->count; i++) {
 701                 int vol_id = req->ents[i].vol_id;
 702                 int name_len = req->ents[i].name_len;
 703                 const char *name = req->ents[i].name;
 704
 705                 re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
 706                 if (!re) {
 707                         err = -ENOMEM;
 708                         goto out_free;
 709                 }
 710
 711                 re->desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
 712                 if (IS_ERR(re->desc)) {
 713                         err = PTR_ERR(re->desc);
 714                         dbg_err("cannot open volume %d, error %d", vol_id, err);
 715                         kfree(re);
 716                         goto out_free;
 717                 }
 718
 719                 /* Skip this re-naming if the name does not really change */
 720                 if (re->desc->vol->name_len == name_len &&
 721                     !memcmp(re->desc->vol->name, name, name_len)) {
 722                         ubi_close_volume(re->desc);
 723                         kfree(re);
 724                         continue;
 725                 }
 726
 727                 re->new_name_len = name_len;
 728                 memcpy(re->new_name, name, name_len);
 729                 list_add_tail(&re->list, &rename_list);
 730                 dbg_msg("will rename volume %d from \"%s\" to \"%s\"",
 731                         vol_id, re->desc->vol->name, name);
 732         }
 733
 734         if (list_empty(&rename_list))
 735                 return 0;
 736
 737         /* Find out the volumes which have to be removed */
 738         list_for_each_entry(re, &rename_list, list) {
 739                 struct ubi_volume_desc *desc;
 740                 int no_remove_needed = 0;
 741
 742                 /*
 743                  * Volume @re->vol_id is going to be re-named to
 744                  * @re->new_name, while its current name is @name. If a volume
 745                  * with name @re->new_name currently exists, it has to be
 746                  * removed, unless it is also re-named in the request (@req).
 747                  */
 748                 list_for_each_entry(re1, &rename_list, list) {
 749                         if (re->new_name_len == re1->desc->vol->name_len &&
 750                             !memcmp(re->new_name, re1->desc->vol->name,
 751                                     re1->desc->vol->name_len)) {
 752                                 no_remove_needed = 1;
 753                                 break;
 754                         }
 755                 }
 756
 757                 if (no_remove_needed)
 758                         continue;
 759
 760                 /*
 761                  * It seems we need to remove volume with name @re->new_name,
 762                  * if it exists.
 763                  */
 764                 desc = ubi_open_volume_nm(ubi->ubi_num, re->new_name,
 765                                           UBI_EXCLUSIVE);
 766                 if (IS_ERR(desc)) {
 767                         err = PTR_ERR(desc);
 768                         if (err == -ENODEV)
 769                                 /* Re-naming into a non-existing volume name */
 770                                 continue;
 771
 772                         /* The volume exists but busy, or an error occurred */
 773                         dbg_err("cannot open volume \"%s\", error %d",
 774                                 re->new_name, err);
 775                         goto out_free;
 776                 }
 777
 778                 re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
 779                 if (!re) {
 780                         err = -ENOMEM;
 781                         ubi_close_volume(desc);
 782                         goto out_free;
 783                 }
 784
 785                 re->remove = 1;
 786                 re->desc = desc;
 787                 list_add(&re->list, &rename_list);
 788                 dbg_msg("will remove volume %d, name \"%s\"",
 789                         re->desc->vol->vol_id, re->desc->vol->name);
 790         }
 791
 792         mutex_lock(&ubi->volumes_mutex);
 793         err = ubi_rename_volumes(ubi, &rename_list);
 794         mutex_unlock(&ubi->volumes_mutex);
 795
 796 out_free:
 797         list_for_each_entry_safe(re, re1, &rename_list, list) {
 798                 ubi_close_volume(re->desc);
 799                 list_del(&re->list);
 800                 kfree(re);
 801         }
 802         return err;
 803 }
 804
 805 static int ubi_cdev_ioctl(struct inode *inode, struct file *file,
 806                           unsigned int cmd, unsigned long arg)
 807 {
 808         int err = 0;
 809         struct ubi_device *ubi;
 810         struct ubi_volume_desc *desc;
 811         void __user *argp = (void __user *)arg;
 812
 813         if (!capable(CAP_SYS_RESOURCE))
 814                 return -EPERM;
 815
 816         ubi = ubi_get_by_major(imajor(inode));
 817         if (!ubi)
 818                 return -ENODEV;
 819
 820         switch (cmd) {
 821         /* Create volume command */
 822         case UBI_IOCMKVOL:
 823         {
 824                 struct ubi_mkvol_req req;
 825
 826                 dbg_gen("create volume");
 827                 err = copy_from_user(&req, argp, sizeof(struct ubi_mkvol_req));
 828                 if (err) {
 829                         err = -EFAULT;
 830                         break;
 831                 }
 832
 833                 req.name[req.name_len] = '\0';
 834                 err = verify_mkvol_req(ubi, &req);
 835                 if (err)
 836                         break;
 837
 838                 mutex_lock(&ubi->volumes_mutex);
 839                 err = ubi_create_volume(ubi, &req);
 840                 mutex_unlock(&ubi->volumes_mutex);
 841                 if (err)
 842                         break;
 843
 844                 err = put_user(req.vol_id, (__user int32_t *)argp);
 845                 if (err)
 846                         err = -EFAULT;
 847
 848                 break;
 849         }
 850
 851         /* Remove volume command */
 852         case UBI_IOCRMVOL:
 853         {
 854                 int vol_id;
 855
 856                 dbg_gen("remove volume");
 857                 err = get_user(vol_id, (__user int32_t *)argp);
 858                 if (err) {
 859                         err = -EFAULT;
 860                         break;
 861                 }
 862
 863                 desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
 864                 if (IS_ERR(desc)) {
 865                         err = PTR_ERR(desc);
 866                         break;
 867                 }
 868
 869                 mutex_lock(&ubi->volumes_mutex);
 870                 err = ubi_remove_volume(desc, 0);
 871                 mutex_unlock(&ubi->volumes_mutex);
 872
 873                 /*
 874                  * The volume is deleted (unless an error occurred), and the
 875                  * 'struct ubi_volume' object will be freed when
 876                  * 'ubi_close_volume()' will call 'put_device()'.
 877                  */
 878                 ubi_close_volume(desc);
 879                 break;
 880         }
 881
 882         /* Re-size volume command */
 883         case UBI_IOCRSVOL:
 884         {
 885                 int pebs;
 886                 uint64_t tmp;
 887                 struct ubi_rsvol_req req;
 888
 889                 dbg_gen("re-size volume");
 890                 err = copy_from_user(&req, argp, sizeof(struct ubi_rsvol_req));
 891                 if (err) {
 892                         err = -EFAULT;
 893                         break;
 894                 }
 895
 896                 err = verify_rsvol_req(ubi, &req);
 897                 if (err)
 898                         break;
 899
 900                 desc = ubi_open_volume(ubi->ubi_num, req.vol_id, UBI_EXCLUSIVE);
 901                 if (IS_ERR(desc)) {
 902                         err = PTR_ERR(desc);
 903                         break;
 904                 }
 905
 906                 tmp = req.bytes;
 907                 pebs = !!do_div(tmp, desc->vol->usable_leb_size);
 908                 pebs += tmp;
 909
 910                 mutex_lock(&ubi->volumes_mutex);
 911                 err = ubi_resize_volume(desc, pebs);
 912                 mutex_unlock(&ubi->volumes_mutex);
 913                 ubi_close_volume(desc);
 914                 break;
 915         }
 916
 917         /* Re-name volumes command */
 918         case UBI_IOCRNVOL:
 919         {
 920                 struct ubi_rnvol_req *req;
 921
 922                 dbg_msg("re-name volumes");
 923                 req = kmalloc(sizeof(struct ubi_rnvol_req), GFP_KERNEL);
 924                 if (!req) {
 925                         err = -ENOMEM;
 926                         break;
 927                 };
 928
 929                 err = copy_from_user(req, argp, sizeof(struct ubi_rnvol_req));
 930                 if (err) {
 931                         err = -EFAULT;
 932                         kfree(req);
 933                         break;
 934                 }
 935
 936                 mutex_lock(&ubi->mult_mutex);
 937                 err = rename_volumes(ubi, req);
 938                 mutex_unlock(&ubi->mult_mutex);
 939                 kfree(req);
 940                 break;
 941         }
 942
 943         default:
 944                 err = -ENOTTY;
 945                 break;
 946         }
 947
 948         ubi_put_device(ubi);
 949         return err;
 950 }
 951
 952 static int ctrl_cdev_ioctl(struct inode *inode, struct file *file,
 953                            unsigned int cmd, unsigned long arg)
 954 {
 955         int err = 0;
 956         void __user *argp = (void __user *)arg;
 957
 958         if (!capable(CAP_SYS_RESOURCE))
 959                 return -EPERM;
 960
 961         switch (cmd) {
 962         /* Attach an MTD device command */
 963         case UBI_IOCATT:
 964         {
 965                 struct ubi_attach_req req;
 966                 struct mtd_info *mtd;
 967
 968                 dbg_gen("attach MTD device");
 969                 err = copy_from_user(&req, argp, sizeof(struct ubi_attach_req));
 970                 if (err) {
 971                         err = -EFAULT;
 972                         break;
 973                 }
 974
 975                 if (req.mtd_num < 0 ||
 976                     (req.ubi_num < 0 && req.ubi_num != UBI_DEV_NUM_AUTO)) {
 977                         err = -EINVAL;
 978                         break;
 979                 }
 980
 981                 mtd = get_mtd_device(NULL, req.mtd_num);
 982                 if (IS_ERR(mtd)) {
 983                         err = PTR_ERR(mtd);
 984                         break;
 985                 }
 986
 987                 /*
 988                  * Note, further request verification is done by
 989                  * 'ubi_attach_mtd_dev()'.
 990                  */
 991                 mutex_lock(&ubi_devices_mutex);
 992                 err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset);
 993                 mutex_unlock(&ubi_devices_mutex);
 994                 if (err < 0)
 995                         put_mtd_device(mtd);
 996                 else
 997                         /* @err contains UBI device number */
 998                         err = put_user(err, (__user int32_t *)argp);
 999
1000                 break;
1001         }
1002
1003         /* Detach an MTD device command */
1004         case UBI_IOCDET:
1005         {
1006                 int ubi_num;
1007
1008                 dbg_gen("dettach MTD device");
1009                 err = get_user(ubi_num, (__user int32_t *)argp);
1010                 if (err) {
1011                         err = -EFAULT;
1012                         break;
1013                 }
1014
1015                 mutex_lock(&ubi_devices_mutex);
1016                 err = ubi_detach_mtd_dev(ubi_num, 0);
1017                 mutex_unlock(&ubi_devices_mutex);
1018                 break;
1019         }
1020
1021         default:
1022                 err = -ENOTTY;
1023                 break;
1024         }
1025
1026         return err;
1027 }
1028
1029 /* UBI control character device operations */
1030 struct file_operations ubi_ctrl_cdev_operations = {
1031         .ioctl = ctrl_cdev_ioctl,
1032         .owner = THIS_MODULE,
1033 };
1034
1035 /* UBI character device operations */
1036 struct file_operations ubi_cdev_operations = {
1037         .owner = THIS_MODULE,
1038         .ioctl = ubi_cdev_ioctl,
1039         .llseek = no_llseek,
1040 };
1041
1042 /* UBI volume character device operations */
1043 struct file_operations ubi_vol_cdev_operations = {
1044         .owner   = THIS_MODULE,
1045         .open    = vol_cdev_open,
1046         .release = vol_cdev_release,
1047         .llseek  = vol_cdev_llseek,
1048         .read    = vol_cdev_read,
1049         .write   = vol_cdev_write,
1050         .ioctl   = vol_cdev_ioctl,
1051 };