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 int vol_cdev_fsync(struct file *file, struct dentry *dentry,
 190                           int datasync)
 191 {
 192         struct ubi_volume_desc *desc = file->private_data;
 193         struct ubi_device *ubi = desc->vol->ubi;
 194
 195         return ubi_sync(ubi->ubi_num);
 196 }
 197
 198
 199 static ssize_t vol_cdev_read(struct file *file, __user char *buf, size_t count,
 200                              loff_t *offp)
 201 {
 202         struct ubi_volume_desc *desc = file->private_data;
 203         struct ubi_volume *vol = desc->vol;
 204         struct ubi_device *ubi = vol->ubi;
 205         int err, lnum, off, len,  tbuf_size;
 206         size_t count_save = count;
 207         void *tbuf;
 208
 209         dbg_gen("read %zd bytes from offset %lld of volume %d",
 210                 count, *offp, vol->vol_id);
 211
 212         if (vol->updating) {
 213                 dbg_err("updating");
 214                 return -EBUSY;
 215         }
 216         if (vol->upd_marker) {
 217                 dbg_err("damaged volume, update marker is set");
 218                 return -EBADF;
 219         }
 220         if (*offp == vol->used_bytes || count == 0)
 221                 return 0;
 222
 223         if (vol->corrupted)
 224                 dbg_gen("read from corrupted volume %d", vol->vol_id);
 225
 226         if (*offp + count > vol->used_bytes)
 227                 count_save = count = vol->used_bytes - *offp;
 228
 229         tbuf_size = vol->usable_leb_size;
 230         if (count < tbuf_size)
 231                 tbuf_size = ALIGN(count, ubi->min_io_size);
 232         tbuf = vmalloc(tbuf_size);
 233         if (!tbuf)
 234                 return -ENOMEM;
 235
 236         len = count > tbuf_size ? tbuf_size : count;
 237         lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
 238
 239         do {
 240                 cond_resched();
 241
 242                 if (off + len >= vol->usable_leb_size)
 243                         len = vol->usable_leb_size - off;
 244
 245                 err = ubi_eba_read_leb(ubi, vol, lnum, tbuf, off, len, 0);
 246                 if (err)
 247                         break;
 248
 249                 off += len;
 250                 if (off == vol->usable_leb_size) {
 251                         lnum += 1;
 252                         off -= vol->usable_leb_size;
 253                 }
 254
 255                 count -= len;
 256                 *offp += len;
 257
 258                 err = copy_to_user(buf, tbuf, len);
 259                 if (err) {
 260                         err = -EFAULT;
 261                         break;
 262                 }
 263
 264                 buf += len;
 265                 len = count > tbuf_size ? tbuf_size : count;
 266         } while (count);
 267
 268         vfree(tbuf);
 269         return err ? err : count_save - count;
 270 }
 271
 272 /*
 273  * This function allows to directly write to dynamic UBI volumes, without
 274  * issuing the volume update operation.
 275  */
 276 static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
 277                                      size_t count, loff_t *offp)
 278 {
 279         struct ubi_volume_desc *desc = file->private_data;
 280         struct ubi_volume *vol = desc->vol;
 281         struct ubi_device *ubi = vol->ubi;
 282         int lnum, off, len, tbuf_size, err = 0;
 283         size_t count_save = count;
 284         char *tbuf;
 285
 286         if (!vol->direct_writes)
 287                 return -EPERM;
 288
 289         dbg_gen("requested: write %zd bytes to offset %lld of volume %u",
 290                 count, *offp, vol->vol_id);
 291
 292         if (vol->vol_type == UBI_STATIC_VOLUME)
 293                 return -EROFS;
 294
 295         lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
 296         if (off & (ubi->min_io_size - 1)) {
 297                 dbg_err("unaligned position");
 298                 return -EINVAL;
 299         }
 300
 301         if (*offp + count > vol->used_bytes)
 302                 count_save = count = vol->used_bytes - *offp;
 303
 304         /* We can write only in fractions of the minimum I/O unit */
 305         if (count & (ubi->min_io_size - 1)) {
 306                 dbg_err("unaligned write length");
 307                 return -EINVAL;
 308         }
 309
 310         tbuf_size = vol->usable_leb_size;
 311         if (count < tbuf_size)
 312                 tbuf_size = ALIGN(count, ubi->min_io_size);
 313         tbuf = vmalloc(tbuf_size);
 314         if (!tbuf)
 315                 return -ENOMEM;
 316
 317         len = count > tbuf_size ? tbuf_size : count;
 318
 319         while (count) {
 320                 cond_resched();
 321
 322                 if (off + len >= vol->usable_leb_size)
 323                         len = vol->usable_leb_size - off;
 324
 325                 err = copy_from_user(tbuf, buf, len);
 326                 if (err) {
 327                         err = -EFAULT;
 328                         break;
 329                 }
 330
 331                 err = ubi_eba_write_leb(ubi, vol, lnum, tbuf, off, len,
 332                                         UBI_UNKNOWN);
 333                 if (err)
 334                         break;
 335
 336                 off += len;
 337                 if (off == vol->usable_leb_size) {
 338                         lnum += 1;
 339                         off -= vol->usable_leb_size;
 340                 }
 341
 342                 count -= len;
 343                 *offp += len;
 344                 buf += len;
 345                 len = count > tbuf_size ? tbuf_size : count;
 346         }
 347
 348         vfree(tbuf);
 349         return err ? err : count_save - count;
 350 }
 351
 352 static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
 353                               size_t count, loff_t *offp)
 354 {
 355         int err = 0;
 356         struct ubi_volume_desc *desc = file->private_data;
 357         struct ubi_volume *vol = desc->vol;
 358         struct ubi_device *ubi = vol->ubi;
 359
 360         if (!vol->updating && !vol->changing_leb)
 361                 return vol_cdev_direct_write(file, buf, count, offp);
 362
 363         if (vol->updating)
 364                 err = ubi_more_update_data(ubi, vol, buf, count);
 365         else
 366                 err = ubi_more_leb_change_data(ubi, vol, buf, count);
 367
 368         if (err < 0) {
 369                 ubi_err("cannot accept more %zd bytes of data, error %d",
 370                         count, err);
 371                 return err;
 372         }
 373
 374         if (err) {
 375                 /*
 376                  * The operation is finished, @err contains number of actually
 377                  * written bytes.
 378                  */
 379                 count = err;
 380
 381                 if (vol->changing_leb) {
 382                         revoke_exclusive(desc, UBI_READWRITE);
 383                         return count;
 384                 }
 385
 386                 err = ubi_check_volume(ubi, vol->vol_id);
 387                 if (err < 0)
 388                         return err;
 389
 390                 if (err) {
 391                         ubi_warn("volume %d on UBI device %d is corrupted",
 392                                  vol->vol_id, ubi->ubi_num);
 393                         vol->corrupted = 1;
 394                 }
 395                 vol->checked = 1;
 396                 ubi_gluebi_updated(vol);
 397                 revoke_exclusive(desc, UBI_READWRITE);
 398         }
 399
 400         return count;
 401 }
 402
 403 static long vol_cdev_ioctl(struct file *file, unsigned int cmd,
 404                            unsigned long arg)
 405 {
 406         int err = 0;
 407         struct ubi_volume_desc *desc = file->private_data;
 408         struct ubi_volume *vol = desc->vol;
 409         struct ubi_device *ubi = vol->ubi;
 410         void __user *argp = (void __user *)arg;
 411
 412         switch (cmd) {
 413         /* Volume update command */
 414         case UBI_IOCVOLUP:
 415         {
 416                 int64_t bytes, rsvd_bytes;
 417
 418                 if (!capable(CAP_SYS_RESOURCE)) {
 419                         err = -EPERM;
 420                         break;
 421                 }
 422
 423                 err = copy_from_user(&bytes, argp, sizeof(int64_t));
 424                 if (err) {
 425                         err = -EFAULT;
 426                         break;
 427                 }
 428
 429                 if (desc->mode == UBI_READONLY) {
 430                         err = -EROFS;
 431                         break;
 432                 }
 433
 434                 rsvd_bytes = (long long)vol->reserved_pebs *
 435                                         ubi->leb_size-vol->data_pad;
 436                 if (bytes < 0 || bytes > rsvd_bytes) {
 437                         err = -EINVAL;
 438                         break;
 439                 }
 440
 441                 err = get_exclusive(desc);
 442                 if (err < 0)
 443                         break;
 444
 445                 err = ubi_start_update(ubi, vol, bytes);
 446                 if (bytes == 0)
 447                         revoke_exclusive(desc, UBI_READWRITE);
 448                 break;
 449         }
 450
 451         /* Atomic logical eraseblock change command */
 452         case UBI_IOCEBCH:
 453         {
 454                 struct ubi_leb_change_req req;
 455
 456                 err = copy_from_user(&req, argp,
 457                                      sizeof(struct ubi_leb_change_req));
 458                 if (err) {
 459                         err = -EFAULT;
 460                         break;
 461                 }
 462
 463                 if (desc->mode == UBI_READONLY ||
 464                     vol->vol_type == UBI_STATIC_VOLUME) {
 465                         err = -EROFS;
 466                         break;
 467                 }
 468
 469                 /* Validate the request */
 470                 err = -EINVAL;
 471                 if (req.lnum < 0 || req.lnum >= vol->reserved_pebs ||
 472                     req.bytes < 0 || req.lnum >= vol->usable_leb_size)
 473                         break;
 474                 if (req.dtype != UBI_LONGTERM && req.dtype != UBI_SHORTTERM &&
 475                     req.dtype != UBI_UNKNOWN)
 476                         break;
 477
 478                 err = get_exclusive(desc);
 479                 if (err < 0)
 480                         break;
 481
 482                 err = ubi_start_leb_change(ubi, vol, &req);
 483                 if (req.bytes == 0)
 484                         revoke_exclusive(desc, UBI_READWRITE);
 485                 break;
 486         }
 487
 488         /* Logical eraseblock erasure command */
 489         case UBI_IOCEBER:
 490         {
 491                 int32_t lnum;
 492
 493                 err = get_user(lnum, (__user int32_t *)argp);
 494                 if (err) {
 495                         err = -EFAULT;
 496                         break;
 497                 }
 498
 499                 if (desc->mode == UBI_READONLY ||
 500                     vol->vol_type == UBI_STATIC_VOLUME) {
 501                         err = -EROFS;
 502                         break;
 503                 }
 504
 505                 if (lnum < 0 || lnum >= vol->reserved_pebs) {
 506                         err = -EINVAL;
 507                         break;
 508                 }
 509
 510                 dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
 511                 err = ubi_eba_unmap_leb(ubi, vol, lnum);
 512                 if (err)
 513                         break;
 514
 515                 err = ubi_wl_flush(ubi);
 516                 break;
 517         }
 518
 519         /* Logical eraseblock map command */
 520         case UBI_IOCEBMAP:
 521         {
 522                 struct ubi_map_req req;
 523
 524                 err = copy_from_user(&req, argp, sizeof(struct ubi_map_req));
 525                 if (err) {
 526                         err = -EFAULT;
 527                         break;
 528                 }
 529                 err = ubi_leb_map(desc, req.lnum, req.dtype);
 530                 break;
 531         }
 532
 533         /* Logical eraseblock un-map command */
 534         case UBI_IOCEBUNMAP:
 535         {
 536                 int32_t lnum;
 537
 538                 err = get_user(lnum, (__user int32_t *)argp);
 539                 if (err) {
 540                         err = -EFAULT;
 541                         break;
 542                 }
 543                 err = ubi_leb_unmap(desc, lnum);
 544                 break;
 545         }
 546
 547         /* Check if logical eraseblock is mapped command */
 548         case UBI_IOCEBISMAP:
 549         {
 550                 int32_t lnum;
 551
 552                 err = get_user(lnum, (__user int32_t *)argp);
 553                 if (err) {
 554                         err = -EFAULT;
 555                         break;
 556                 }
 557                 err = ubi_is_mapped(desc, lnum);
 558                 break;
 559         }
 560
 561         /* Set volume property command*/
 562         case UBI_IOCSETPROP:
 563         {
 564                 struct ubi_set_prop_req req;
 565
 566                 err = copy_from_user(&req, argp,
 567                                 sizeof(struct ubi_set_prop_req));
 568                 if (err) {
 569                         err = -EFAULT;
 570                         break;
 571                 }
 572                 switch (req.property) {
 573                 case UBI_PROP_DIRECT_WRITE:
 574                         mutex_lock(&ubi->volumes_mutex);
 575                         desc->vol->direct_writes = !!req.value;
 576                         mutex_unlock(&ubi->volumes_mutex);
 577                         break;
 578                 default:
 579                         err = -EINVAL;
 580                         break;
 581                 }
 582                 break;
 583         }
 584
 585         default:
 586                 err = -ENOTTY;
 587                 break;
 588         }
 589         return err;
 590 }
 591
 592 /**
 593  * verify_mkvol_req - verify volume creation request.
 594  * @ubi: UBI device description object
 595  * @req: the request to check
 596  *
 597  * This function zero if the request is correct, and %-EINVAL if not.
 598  */
 599 static int verify_mkvol_req(const struct ubi_device *ubi,
 600                             const struct ubi_mkvol_req *req)
 601 {
 602         int n, err = -EINVAL;
 603
 604         if (req->bytes < 0 || req->alignment < 0 || req->vol_type < 0 ||
 605             req->name_len < 0)
 606                 goto bad;
 607
 608         if ((req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) &&
 609             req->vol_id != UBI_VOL_NUM_AUTO)
 610                 goto bad;
 611
 612         if (req->alignment == 0)
 613                 goto bad;
 614
 615         if (req->bytes == 0)
 616                 goto bad;
 617
 618         if (req->vol_type != UBI_DYNAMIC_VOLUME &&
 619             req->vol_type != UBI_STATIC_VOLUME)
 620                 goto bad;
 621
 622         if (req->alignment > ubi->leb_size)
 623                 goto bad;
 624
 625         n = req->alignment & (ubi->min_io_size - 1);
 626         if (req->alignment != 1 && n)
 627                 goto bad;
 628
 629         if (req->name_len > UBI_VOL_NAME_MAX) {
 630                 err = -ENAMETOOLONG;
 631                 goto bad;
 632         }
 633
 634         n = strnlen(req->name, req->name_len + 1);
 635         if (n != req->name_len)
 636                 goto bad;
 637
 638         return 0;
 639
 640 bad:
 641         dbg_err("bad volume creation request");
 642         ubi_dbg_dump_mkvol_req(req);
 643         return err;
 644 }
 645
 646 /**
 647  * verify_rsvol_req - verify volume re-size request.
 648  * @ubi: UBI device description object
 649  * @req: the request to check
 650  *
 651  * This function returns zero if the request is correct, and %-EINVAL if not.
 652  */
 653 static int verify_rsvol_req(const struct ubi_device *ubi,
 654                             const struct ubi_rsvol_req *req)
 655 {
 656         if (req->bytes <= 0)
 657                 return -EINVAL;
 658
 659         if (req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots)
 660                 return -EINVAL;
 661
 662         return 0;
 663 }
 664
 665 /**
 666  * rename_volumes - rename UBI volumes.
 667  * @ubi: UBI device description object
 668  * @req: volumes re-name request
 669  *
 670  * This is a helper function for the volume re-name IOCTL which validates the
 671  * the request, opens the volume and calls corresponding volumes management
 672  * function. Returns zero in case of success and a negative error code in case
 673  * of failure.
 674  */
 675 static int rename_volumes(struct ubi_device *ubi,
 676                           struct ubi_rnvol_req *req)
 677 {
 678         int i, n, err;
 679         struct list_head rename_list;
 680         struct ubi_rename_entry *re, *re1;
 681
 682         if (req->count < 0 || req->count > UBI_MAX_RNVOL)
 683                 return -EINVAL;
 684
 685         if (req->count == 0)
 686                 return 0;
 687
 688         /* Validate volume IDs and names in the request */
 689         for (i = 0; i < req->count; i++) {
 690                 if (req->ents[i].vol_id < 0 ||
 691                     req->ents[i].vol_id >= ubi->vtbl_slots)
 692                         return -EINVAL;
 693                 if (req->ents[i].name_len < 0)
 694                         return -EINVAL;
 695                 if (req->ents[i].name_len > UBI_VOL_NAME_MAX)
 696                         return -ENAMETOOLONG;
 697                 req->ents[i].name[req->ents[i].name_len] = '\0';
 698                 n = strlen(req->ents[i].name);
 699                 if (n != req->ents[i].name_len)
 700                         err = -EINVAL;
 701         }
 702
 703         /* Make sure volume IDs and names are unique */
 704         for (i = 0; i < req->count - 1; i++) {
 705                 for (n = i + 1; n < req->count; n++) {
 706                         if (req->ents[i].vol_id == req->ents[n].vol_id) {
 707                                 dbg_err("duplicated volume id %d",
 708                                         req->ents[i].vol_id);
 709                                 return -EINVAL;
 710                         }
 711                         if (!strcmp(req->ents[i].name, req->ents[n].name)) {
 712                                 dbg_err("duplicated volume name \"%s\"",
 713                                         req->ents[i].name);
 714                                 return -EINVAL;
 715                         }
 716                 }
 717         }
 718
 719         /* Create the re-name list */
 720         INIT_LIST_HEAD(&rename_list);
 721         for (i = 0; i < req->count; i++) {
 722                 int vol_id = req->ents[i].vol_id;
 723                 int name_len = req->ents[i].name_len;
 724                 const char *name = req->ents[i].name;
 725
 726                 re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
 727                 if (!re) {
 728                         err = -ENOMEM;
 729                         goto out_free;
 730                 }
 731
 732                 re->desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
 733                 if (IS_ERR(re->desc)) {
 734                         err = PTR_ERR(re->desc);
 735                         dbg_err("cannot open volume %d, error %d", vol_id, err);
 736                         kfree(re);
 737                         goto out_free;
 738                 }
 739
 740                 /* Skip this re-naming if the name does not really change */
 741                 if (re->desc->vol->name_len == name_len &&
 742                     !memcmp(re->desc->vol->name, name, name_len)) {
 743                         ubi_close_volume(re->desc);
 744                         kfree(re);
 745                         continue;
 746                 }
 747
 748                 re->new_name_len = name_len;
 749                 memcpy(re->new_name, name, name_len);
 750                 list_add_tail(&re->list, &rename_list);
 751                 dbg_msg("will rename volume %d from \"%s\" to \"%s\"",
 752                         vol_id, re->desc->vol->name, name);
 753         }
 754
 755         if (list_empty(&rename_list))
 756                 return 0;
 757
 758         /* Find out the volumes which have to be removed */
 759         list_for_each_entry(re, &rename_list, list) {
 760                 struct ubi_volume_desc *desc;
 761                 int no_remove_needed = 0;
 762
 763                 /*
 764                  * Volume @re->vol_id is going to be re-named to
 765                  * @re->new_name, while its current name is @name. If a volume
 766                  * with name @re->new_name currently exists, it has to be
 767                  * removed, unless it is also re-named in the request (@req).
 768                  */
 769                 list_for_each_entry(re1, &rename_list, list) {
 770                         if (re->new_name_len == re1->desc->vol->name_len &&
 771                             !memcmp(re->new_name, re1->desc->vol->name,
 772                                     re1->desc->vol->name_len)) {
 773                                 no_remove_needed = 1;
 774                                 break;
 775                         }
 776                 }
 777
 778                 if (no_remove_needed)
 779                         continue;
 780
 781                 /*
 782                  * It seems we need to remove volume with name @re->new_name,
 783                  * if it exists.
 784                  */
 785                 desc = ubi_open_volume_nm(ubi->ubi_num, re->new_name,
 786                                           UBI_EXCLUSIVE);
 787                 if (IS_ERR(desc)) {
 788                         err = PTR_ERR(desc);
 789                         if (err == -ENODEV)
 790                                 /* Re-naming into a non-existing volume name */
 791                                 continue;
 792
 793                         /* The volume exists but busy, or an error occurred */
 794                         dbg_err("cannot open volume \"%s\", error %d",
 795                                 re->new_name, err);
 796                         goto out_free;
 797                 }
 798
 799                 re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
 800                 if (!re) {
 801                         err = -ENOMEM;
 802                         ubi_close_volume(desc);
 803                         goto out_free;
 804                 }
 805
 806                 re->remove = 1;
 807                 re->desc = desc;
 808                 list_add(&re->list, &rename_list);
 809                 dbg_msg("will remove volume %d, name \"%s\"",
 810                         re->desc->vol->vol_id, re->desc->vol->name);
 811         }
 812
 813         mutex_lock(&ubi->volumes_mutex);
 814         err = ubi_rename_volumes(ubi, &rename_list);
 815         mutex_unlock(&ubi->volumes_mutex);
 816
 817 out_free:
 818         list_for_each_entry_safe(re, re1, &rename_list, list) {
 819                 ubi_close_volume(re->desc);
 820                 list_del(&re->list);
 821                 kfree(re);
 822         }
 823         return err;
 824 }
 825
 826 static long ubi_cdev_ioctl(struct file *file, unsigned int cmd,
 827                            unsigned long arg)
 828 {
 829         int err = 0;
 830         struct ubi_device *ubi;
 831         struct ubi_volume_desc *desc;
 832         void __user *argp = (void __user *)arg;
 833
 834         if (!capable(CAP_SYS_RESOURCE))
 835                 return -EPERM;
 836
 837         ubi = ubi_get_by_major(imajor(file->f_mapping->host));
 838         if (!ubi)
 839                 return -ENODEV;
 840
 841         switch (cmd) {
 842         /* Create volume command */
 843         case UBI_IOCMKVOL:
 844         {
 845                 struct ubi_mkvol_req req;
 846
 847                 dbg_gen("create volume");
 848                 err = copy_from_user(&req, argp, sizeof(struct ubi_mkvol_req));
 849                 if (err) {
 850                         err = -EFAULT;
 851                         break;
 852                 }
 853
 854                 req.name[req.name_len] = '\0';
 855                 err = verify_mkvol_req(ubi, &req);
 856                 if (err)
 857                         break;
 858
 859                 mutex_lock(&ubi->volumes_mutex);
 860                 err = ubi_create_volume(ubi, &req);
 861                 mutex_unlock(&ubi->volumes_mutex);
 862                 if (err)
 863                         break;
 864
 865                 err = put_user(req.vol_id, (__user int32_t *)argp);
 866                 if (err)
 867                         err = -EFAULT;
 868
 869                 break;
 870         }
 871
 872         /* Remove volume command */
 873         case UBI_IOCRMVOL:
 874         {
 875                 int vol_id;
 876
 877                 dbg_gen("remove volume");
 878                 err = get_user(vol_id, (__user int32_t *)argp);
 879                 if (err) {
 880                         err = -EFAULT;
 881                         break;
 882                 }
 883
 884                 desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
 885                 if (IS_ERR(desc)) {
 886                         err = PTR_ERR(desc);
 887                         break;
 888                 }
 889
 890                 mutex_lock(&ubi->volumes_mutex);
 891                 err = ubi_remove_volume(desc, 0);
 892                 mutex_unlock(&ubi->volumes_mutex);
 893
 894                 /*
 895                  * The volume is deleted (unless an error occurred), and the
 896                  * 'struct ubi_volume' object will be freed when
 897                  * 'ubi_close_volume()' will call 'put_device()'.
 898                  */
 899                 ubi_close_volume(desc);
 900                 break;
 901         }
 902
 903         /* Re-size volume command */
 904         case UBI_IOCRSVOL:
 905         {
 906                 int pebs;
 907                 struct ubi_rsvol_req req;
 908
 909                 dbg_gen("re-size volume");
 910                 err = copy_from_user(&req, argp, sizeof(struct ubi_rsvol_req));
 911                 if (err) {
 912                         err = -EFAULT;
 913                         break;
 914                 }
 915
 916                 err = verify_rsvol_req(ubi, &req);
 917                 if (err)
 918                         break;
 919
 920                 desc = ubi_open_volume(ubi->ubi_num, req.vol_id, UBI_EXCLUSIVE);
 921                 if (IS_ERR(desc)) {
 922                         err = PTR_ERR(desc);
 923                         break;
 924                 }
 925
 926                 pebs = div_u64(req.bytes + desc->vol->usable_leb_size - 1,
 927                                desc->vol->usable_leb_size);
 928
 929                 mutex_lock(&ubi->volumes_mutex);
 930                 err = ubi_resize_volume(desc, pebs);
 931                 mutex_unlock(&ubi->volumes_mutex);
 932                 ubi_close_volume(desc);
 933                 break;
 934         }
 935
 936         /* Re-name volumes command */
 937         case UBI_IOCRNVOL:
 938         {
 939                 struct ubi_rnvol_req *req;
 940
 941                 dbg_msg("re-name volumes");
 942                 req = kmalloc(sizeof(struct ubi_rnvol_req), GFP_KERNEL);
 943                 if (!req) {
 944                         err = -ENOMEM;
 945                         break;
 946                 };
 947
 948                 err = copy_from_user(req, argp, sizeof(struct ubi_rnvol_req));
 949                 if (err) {
 950                         err = -EFAULT;
 951                         kfree(req);
 952                         break;
 953                 }
 954
 955                 mutex_lock(&ubi->mult_mutex);
 956                 err = rename_volumes(ubi, req);
 957                 mutex_unlock(&ubi->mult_mutex);
 958                 kfree(req);
 959                 break;
 960         }
 961
 962         default:
 963                 err = -ENOTTY;
 964                 break;
 965         }
 966
 967         ubi_put_device(ubi);
 968         return err;
 969 }
 970
 971 static long ctrl_cdev_ioctl(struct file *file, unsigned int cmd,
 972                             unsigned long arg)
 973 {
 974         int err = 0;
 975         void __user *argp = (void __user *)arg;
 976
 977         if (!capable(CAP_SYS_RESOURCE))
 978                 return -EPERM;
 979
 980         switch (cmd) {
 981         /* Attach an MTD device command */
 982         case UBI_IOCATT:
 983         {
 984                 struct ubi_attach_req req;
 985                 struct mtd_info *mtd;
 986
 987                 dbg_gen("attach MTD device");
 988                 err = copy_from_user(&req, argp, sizeof(struct ubi_attach_req));
 989                 if (err) {
 990                         err = -EFAULT;
 991                         break;
 992                 }
 993
 994                 if (req.mtd_num < 0 ||
 995                     (req.ubi_num < 0 && req.ubi_num != UBI_DEV_NUM_AUTO)) {
 996                         err = -EINVAL;
 997                         break;
 998                 }
 999
1000                 mtd = get_mtd_device(NULL, req.mtd_num);
1001                 if (IS_ERR(mtd)) {
1002                         err = PTR_ERR(mtd);
1003                         break;
1004                 }
1005
1006                 /*
1007                  * Note, further request verification is done by
1008                  * 'ubi_attach_mtd_dev()'.
1009                  */
1010                 mutex_lock(&ubi_devices_mutex);
1011                 err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset);
1012                 mutex_unlock(&ubi_devices_mutex);
1013                 if (err < 0)
1014                         put_mtd_device(mtd);
1015                 else
1016                         /* @err contains UBI device number */
1017                         err = put_user(err, (__user int32_t *)argp);
1018
1019                 break;
1020         }
1021
1022         /* Detach an MTD device command */
1023         case UBI_IOCDET:
1024         {
1025                 int ubi_num;
1026
1027                 dbg_gen("dettach MTD device");
1028                 err = get_user(ubi_num, (__user int32_t *)argp);
1029                 if (err) {
1030                         err = -EFAULT;
1031                         break;
1032                 }
1033
1034                 mutex_lock(&ubi_devices_mutex);
1035                 err = ubi_detach_mtd_dev(ubi_num, 0);
1036                 mutex_unlock(&ubi_devices_mutex);
1037                 break;
1038         }
1039
1040         default:
1041                 err = -ENOTTY;
1042                 break;
1043         }
1044
1045         return err;
1046 }
1047
1048 #ifdef CONFIG_COMPAT
1049 static long vol_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1050                                   unsigned long arg)
1051 {
1052         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1053
1054         return vol_cdev_ioctl(file, cmd, translated_arg);
1055 }
1056
1057 static long ubi_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1058                                   unsigned long arg)
1059 {
1060         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1061
1062         return ubi_cdev_ioctl(file, cmd, translated_arg);
1063 }
1064
1065 static long ctrl_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1066                                    unsigned long arg)
1067 {
1068         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1069
1070         return ctrl_cdev_ioctl(file, cmd, translated_arg);
1071 }
1072 #else
1073 #define vol_cdev_compat_ioctl  NULL
1074 #define ubi_cdev_compat_ioctl  NULL
1075 #define ctrl_cdev_compat_ioctl NULL
1076 #endif
1077
1078 /* UBI volume character device operations */
1079 const struct file_operations ubi_vol_cdev_operations = {
1080         .owner          = THIS_MODULE,
1081         .open           = vol_cdev_open,
1082         .release        = vol_cdev_release,
1083         .llseek         = vol_cdev_llseek,
1084         .read           = vol_cdev_read,
1085         .write          = vol_cdev_write,
1086         .fsync          = vol_cdev_fsync,
1087         .unlocked_ioctl = vol_cdev_ioctl,
1088         .compat_ioctl   = vol_cdev_compat_ioctl,
1089 };
1090
1091 /* UBI character device operations */
1092 const struct file_operations ubi_cdev_operations = {
1093         .owner          = THIS_MODULE,
1094         .llseek         = no_llseek,
1095         .unlocked_ioctl = ubi_cdev_ioctl,
1096         .compat_ioctl   = ubi_cdev_compat_ioctl,
1097 };
1098
1099 /* UBI control character device operations */
1100 const struct file_operations ubi_ctrl_cdev_operations = {
1101         .owner          = THIS_MODULE,
1102         .unlocked_ioctl = ctrl_cdev_ioctl,
1103         .compat_ioctl   = ctrl_cdev_compat_ioctl,
1104 };