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