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  * @ubi: UBI device description object
  52  * @desc: volume descriptor
  53  *
  54  * This function changes UBI volume open mode to "exclusive". Returns previous
  55  * mode value (positive integer) in case of success and a negative error code
  56  * in case of failure.
  57  */
  58 static int get_exclusive(struct ubi_device *ubi, struct ubi_volume_desc *desc)
  59 {
  60         int users, err;
  61         struct ubi_volume *vol = desc->vol;
  62
  63         spin_lock(&vol->ubi->volumes_lock);
  64         users = vol->readers + vol->writers + vol->exclusive;
  65         ubi_assert(users > 0);
  66         if (users > 1) {
  67                 ubi_err(ubi, "%d users for volume %d", users, vol->vol_id);
  68                 err = -EBUSY;
  69         } else {
  70                 vol->readers = vol->writers = 0;
  71                 vol->exclusive = 1;
  72                 err = desc->mode;
  73                 desc->mode = UBI_EXCLUSIVE;
  74         }
  75         spin_unlock(&vol->ubi->volumes_lock);
  76
  77         return err;
  78 }
  79
  80 /**
  81  * revoke_exclusive - revoke exclusive mode.
  82  * @desc: volume descriptor
  83  * @mode: new mode to switch to
  84  */
  85 static void revoke_exclusive(struct ubi_volume_desc *desc, int mode)
  86 {
  87         struct ubi_volume *vol = desc->vol;
  88
  89         spin_lock(&vol->ubi->volumes_lock);
  90         ubi_assert(vol->readers == 0 && vol->writers == 0);
  91         ubi_assert(vol->exclusive == 1 && desc->mode == UBI_EXCLUSIVE);
  92         vol->exclusive = 0;
  93         if (mode == UBI_READONLY)
  94                 vol->readers = 1;
  95         else if (mode == UBI_READWRITE)
  96                 vol->writers = 1;
  97         else
  98                 vol->exclusive = 1;
  99         spin_unlock(&vol->ubi->volumes_lock);
 100
 101         desc->mode = mode;
 102 }
 103
 104 static int vol_cdev_open(struct inode *inode, struct file *file)
 105 {
 106         struct ubi_volume_desc *desc;
 107         int vol_id = iminor(inode) - 1, mode, ubi_num;
 108
 109         ubi_num = ubi_major2num(imajor(inode));
 110         if (ubi_num < 0)
 111                 return ubi_num;
 112
 113         if (file->f_mode & FMODE_WRITE)
 114                 mode = UBI_READWRITE;
 115         else
 116                 mode = UBI_READONLY;
 117
 118         dbg_gen("open device %d, volume %d, mode %d",
 119                 ubi_num, vol_id, mode);
 120
 121         desc = ubi_open_volume(ubi_num, vol_id, mode);
 122         if (IS_ERR(desc))
 123                 return PTR_ERR(desc);
 124
 125         file->private_data = desc;
 126         return 0;
 127 }
 128
 129 static int vol_cdev_release(struct inode *inode, struct file *file)
 130 {
 131         struct ubi_volume_desc *desc = file->private_data;
 132         struct ubi_volume *vol = desc->vol;
 133
 134         dbg_gen("release device %d, volume %d, mode %d",
 135                 vol->ubi->ubi_num, vol->vol_id, desc->mode);
 136
 137         if (vol->updating) {
 138                 ubi_warn(vol->ubi, "update of volume %d not finished, volume is damaged",
 139                          vol->vol_id);
 140                 ubi_assert(!vol->changing_leb);
 141                 vol->updating = 0;
 142                 vfree(vol->upd_buf);
 143         } else if (vol->changing_leb) {
 144                 dbg_gen("only %lld of %lld bytes received for atomic LEB change for volume %d:%d, cancel",
 145                         vol->upd_received, vol->upd_bytes, vol->ubi->ubi_num,
 146                         vol->vol_id);
 147                 vol->changing_leb = 0;
 148                 vfree(vol->upd_buf);
 149         }
 150
 151         ubi_close_volume(desc);
 152         return 0;
 153 }
 154
 155 static loff_t vol_cdev_llseek(struct file *file, loff_t offset, int origin)
 156 {
 157         struct ubi_volume_desc *desc = file->private_data;
 158         struct ubi_volume *vol = desc->vol;
 159
 160         if (vol->updating) {
 161                 /* Update is in progress, seeking is prohibited */
 162                 ubi_err(vol->ubi, "updating");
 163                 return -EBUSY;
 164         }
 165
 166         return fixed_size_llseek(file, offset, origin, vol->used_bytes);
 167 }
 168
 169 static int vol_cdev_fsync(struct file *file, loff_t start, loff_t end,
 170                           int datasync)
 171 {
 172         struct ubi_volume_desc *desc = file->private_data;
 173         struct ubi_device *ubi = desc->vol->ubi;
 174         struct inode *inode = file_inode(file);
 175         int err;
 176         mutex_lock(&inode->i_mutex);
 177         err = ubi_sync(ubi->ubi_num);
 178         mutex_unlock(&inode->i_mutex);
 179         return err;
 180 }
 181
 182
 183 static ssize_t vol_cdev_read(struct file *file, __user char *buf, size_t count,
 184                              loff_t *offp)
 185 {
 186         struct ubi_volume_desc *desc = file->private_data;
 187         struct ubi_volume *vol = desc->vol;
 188         struct ubi_device *ubi = vol->ubi;
 189         int err, lnum, off, len,  tbuf_size;
 190         size_t count_save = count;
 191         void *tbuf;
 192
 193         dbg_gen("read %zd bytes from offset %lld of volume %d",
 194                 count, *offp, vol->vol_id);
 195
 196         if (vol->updating) {
 197                 ubi_err(vol->ubi, "updating");
 198                 return -EBUSY;
 199         }
 200         if (vol->upd_marker) {
 201                 ubi_err(vol->ubi, "damaged volume, update marker is set");
 202                 return -EBADF;
 203         }
 204         if (*offp == vol->used_bytes || count == 0)
 205                 return 0;
 206
 207         if (vol->corrupted)
 208                 dbg_gen("read from corrupted volume %d", vol->vol_id);
 209
 210         if (*offp + count > vol->used_bytes)
 211                 count_save = count = vol->used_bytes - *offp;
 212
 213         tbuf_size = vol->usable_leb_size;
 214         if (count < tbuf_size)
 215                 tbuf_size = ALIGN(count, ubi->min_io_size);
 216         tbuf = vmalloc(tbuf_size);
 217         if (!tbuf)
 218                 return -ENOMEM;
 219
 220         len = count > tbuf_size ? tbuf_size : count;
 221         lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
 222
 223         do {
 224                 cond_resched();
 225
 226                 if (off + len >= vol->usable_leb_size)
 227                         len = vol->usable_leb_size - off;
 228
 229                 err = ubi_eba_read_leb(ubi, vol, lnum, tbuf, off, len, 0);
 230                 if (err)
 231                         break;
 232
 233                 off += len;
 234                 if (off == vol->usable_leb_size) {
 235                         lnum += 1;
 236                         off -= vol->usable_leb_size;
 237                 }
 238
 239                 count -= len;
 240                 *offp += len;
 241
 242                 err = copy_to_user(buf, tbuf, len);
 243                 if (err) {
 244                         err = -EFAULT;
 245                         break;
 246                 }
 247
 248                 buf += len;
 249                 len = count > tbuf_size ? tbuf_size : count;
 250         } while (count);
 251
 252         vfree(tbuf);
 253         return err ? err : count_save - count;
 254 }
 255
 256 /*
 257  * This function allows to directly write to dynamic UBI volumes, without
 258  * issuing the volume update operation.
 259  */
 260 static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
 261                                      size_t count, loff_t *offp)
 262 {
 263         struct ubi_volume_desc *desc = file->private_data;
 264         struct ubi_volume *vol = desc->vol;
 265         struct ubi_device *ubi = vol->ubi;
 266         int lnum, off, len, tbuf_size, err = 0;
 267         size_t count_save = count;
 268         char *tbuf;
 269
 270         if (!vol->direct_writes)
 271                 return -EPERM;
 272
 273         dbg_gen("requested: write %zd bytes to offset %lld of volume %u",
 274                 count, *offp, vol->vol_id);
 275
 276         if (vol->vol_type == UBI_STATIC_VOLUME)
 277                 return -EROFS;
 278
 279         lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
 280         if (off & (ubi->min_io_size - 1)) {
 281                 ubi_err(ubi, "unaligned position");
 282                 return -EINVAL;
 283         }
 284
 285         if (*offp + count > vol->used_bytes)
 286                 count_save = count = vol->used_bytes - *offp;
 287
 288         /* We can write only in fractions of the minimum I/O unit */
 289         if (count & (ubi->min_io_size - 1)) {
 290                 ubi_err(ubi, "unaligned write length");
 291                 return -EINVAL;
 292         }
 293
 294         tbuf_size = vol->usable_leb_size;
 295         if (count < tbuf_size)
 296                 tbuf_size = ALIGN(count, ubi->min_io_size);
 297         tbuf = vmalloc(tbuf_size);
 298         if (!tbuf)
 299                 return -ENOMEM;
 300
 301         len = count > tbuf_size ? tbuf_size : count;
 302
 303         while (count) {
 304                 cond_resched();
 305
 306                 if (off + len >= vol->usable_leb_size)
 307                         len = vol->usable_leb_size - off;
 308
 309                 err = copy_from_user(tbuf, buf, len);
 310                 if (err) {
 311                         err = -EFAULT;
 312                         break;
 313                 }
 314
 315                 err = ubi_eba_write_leb(ubi, vol, lnum, tbuf, off, len);
 316                 if (err)
 317                         break;
 318
 319                 off += len;
 320                 if (off == vol->usable_leb_size) {
 321                         lnum += 1;
 322                         off -= vol->usable_leb_size;
 323                 }
 324
 325                 count -= len;
 326                 *offp += len;
 327                 buf += len;
 328                 len = count > tbuf_size ? tbuf_size : count;
 329         }
 330
 331         vfree(tbuf);
 332         return err ? err : count_save - count;
 333 }
 334
 335 static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
 336                               size_t count, loff_t *offp)
 337 {
 338         int err = 0;
 339         struct ubi_volume_desc *desc = file->private_data;
 340         struct ubi_volume *vol = desc->vol;
 341         struct ubi_device *ubi = vol->ubi;
 342
 343         if (!vol->updating && !vol->changing_leb)
 344                 return vol_cdev_direct_write(file, buf, count, offp);
 345
 346         if (vol->updating)
 347                 err = ubi_more_update_data(ubi, vol, buf, count);
 348         else
 349                 err = ubi_more_leb_change_data(ubi, vol, buf, count);
 350
 351         if (err < 0) {
 352                 ubi_err(ubi, "cannot accept more %zd bytes of data, error %d",
 353                         count, err);
 354                 return err;
 355         }
 356
 357         if (err) {
 358                 /*
 359                  * The operation is finished, @err contains number of actually
 360                  * written bytes.
 361                  */
 362                 count = err;
 363
 364                 if (vol->changing_leb) {
 365                         revoke_exclusive(desc, UBI_READWRITE);
 366                         return count;
 367                 }
 368
 369                 err = ubi_check_volume(ubi, vol->vol_id);
 370                 if (err < 0)
 371                         return err;
 372
 373                 if (err) {
 374                         ubi_warn(ubi, "volume %d on UBI device %d is corrupted",
 375                                  vol->vol_id, ubi->ubi_num);
 376                         vol->corrupted = 1;
 377                 }
 378                 vol->checked = 1;
 379                 ubi_volume_notify(ubi, vol, UBI_VOLUME_UPDATED);
 380                 revoke_exclusive(desc, UBI_READWRITE);
 381         }
 382
 383         return count;
 384 }
 385
 386 static long vol_cdev_ioctl(struct file *file, unsigned int cmd,
 387                            unsigned long arg)
 388 {
 389         int err = 0;
 390         struct ubi_volume_desc *desc = file->private_data;
 391         struct ubi_volume *vol = desc->vol;
 392         struct ubi_device *ubi = vol->ubi;
 393         void __user *argp = (void __user *)arg;
 394
 395         switch (cmd) {
 396         /* Volume update command */
 397         case UBI_IOCVOLUP:
 398         {
 399                 int64_t bytes, rsvd_bytes;
 400
 401                 if (!capable(CAP_SYS_RESOURCE)) {
 402                         err = -EPERM;
 403                         break;
 404                 }
 405
 406                 err = copy_from_user(&bytes, argp, sizeof(int64_t));
 407                 if (err) {
 408                         err = -EFAULT;
 409                         break;
 410                 }
 411
 412                 if (desc->mode == UBI_READONLY) {
 413                         err = -EROFS;
 414                         break;
 415                 }
 416
 417                 rsvd_bytes = (long long)vol->reserved_pebs *
 418                                         ubi->leb_size-vol->data_pad;
 419                 if (bytes < 0 || bytes > rsvd_bytes) {
 420                         err = -EINVAL;
 421                         break;
 422                 }
 423
 424                 err = get_exclusive(ubi, desc);
 425                 if (err < 0)
 426                         break;
 427
 428                 err = ubi_start_update(ubi, vol, bytes);
 429                 if (bytes == 0) {
 430                         ubi_volume_notify(ubi, vol, UBI_VOLUME_UPDATED);
 431                         revoke_exclusive(desc, UBI_READWRITE);
 432                 }
 433                 break;
 434         }
 435
 436         /* Atomic logical eraseblock change command */
 437         case UBI_IOCEBCH:
 438         {
 439                 struct ubi_leb_change_req req;
 440
 441                 err = copy_from_user(&req, argp,
 442                                      sizeof(struct ubi_leb_change_req));
 443                 if (err) {
 444                         err = -EFAULT;
 445                         break;
 446                 }
 447
 448                 if (desc->mode == UBI_READONLY ||
 449                     vol->vol_type == UBI_STATIC_VOLUME) {
 450                         err = -EROFS;
 451                         break;
 452                 }
 453
 454                 /* Validate the request */
 455                 err = -EINVAL;
 456                 if (req.lnum < 0 || req.lnum >= vol->reserved_pebs ||
 457                     req.bytes < 0 || req.lnum >= vol->usable_leb_size)
 458                         break;
 459
 460                 err = get_exclusive(ubi, desc);
 461                 if (err < 0)
 462                         break;
 463
 464                 err = ubi_start_leb_change(ubi, vol, &req);
 465                 if (req.bytes == 0)
 466                         revoke_exclusive(desc, UBI_READWRITE);
 467                 break;
 468         }
 469
 470         /* Logical eraseblock erasure command */
 471         case UBI_IOCEBER:
 472         {
 473                 int32_t lnum;
 474
 475                 err = get_user(lnum, (__user int32_t *)argp);
 476                 if (err) {
 477                         err = -EFAULT;
 478                         break;
 479                 }
 480
 481                 if (desc->mode == UBI_READONLY ||
 482                     vol->vol_type == UBI_STATIC_VOLUME) {
 483                         err = -EROFS;
 484                         break;
 485                 }
 486
 487                 if (lnum < 0 || lnum >= vol->reserved_pebs) {
 488                         err = -EINVAL;
 489                         break;
 490                 }
 491
 492                 dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
 493                 err = ubi_eba_unmap_leb(ubi, vol, lnum);
 494                 if (err)
 495                         break;
 496
 497                 err = ubi_wl_flush(ubi, UBI_ALL, UBI_ALL);
 498                 break;
 499         }
 500
 501         /* Logical eraseblock map command */
 502         case UBI_IOCEBMAP:
 503         {
 504                 struct ubi_map_req req;
 505
 506                 err = copy_from_user(&req, argp, sizeof(struct ubi_map_req));
 507                 if (err) {
 508                         err = -EFAULT;
 509                         break;
 510                 }
 511                 err = ubi_leb_map(desc, req.lnum);
 512                 break;
 513         }
 514
 515         /* Logical eraseblock un-map command */
 516         case UBI_IOCEBUNMAP:
 517         {
 518                 int32_t lnum;
 519
 520                 err = get_user(lnum, (__user int32_t *)argp);
 521                 if (err) {
 522                         err = -EFAULT;
 523                         break;
 524                 }
 525                 err = ubi_leb_unmap(desc, lnum);
 526                 break;
 527         }
 528
 529         /* Check if logical eraseblock is mapped command */
 530         case UBI_IOCEBISMAP:
 531         {
 532                 int32_t lnum;
 533
 534                 err = get_user(lnum, (__user int32_t *)argp);
 535                 if (err) {
 536                         err = -EFAULT;
 537                         break;
 538                 }
 539                 err = ubi_is_mapped(desc, lnum);
 540                 break;
 541         }
 542
 543         /* Set volume property command */
 544         case UBI_IOCSETVOLPROP:
 545         {
 546                 struct ubi_set_vol_prop_req req;
 547
 548                 err = copy_from_user(&req, argp,
 549                                      sizeof(struct ubi_set_vol_prop_req));
 550                 if (err) {
 551                         err = -EFAULT;
 552                         break;
 553                 }
 554                 switch (req.property) {
 555                 case UBI_VOL_PROP_DIRECT_WRITE:
 556                         mutex_lock(&ubi->device_mutex);
 557                         desc->vol->direct_writes = !!req.value;
 558                         mutex_unlock(&ubi->device_mutex);
 559                         break;
 560                 default:
 561                         err = -EINVAL;
 562                         break;
 563                 }
 564                 break;
 565         }
 566
 567         /* Create a R/O block device on top of the UBI volume */
 568         case UBI_IOCVOLCRBLK:
 569         {
 570                 struct ubi_volume_info vi;
 571
 572                 ubi_get_volume_info(desc, &vi);
 573                 err = ubiblock_create(&vi);
 574                 break;
 575         }
 576
 577         /* Remove the R/O block device */
 578         case UBI_IOCVOLRMBLK:
 579         {
 580                 struct ubi_volume_info vi;
 581
 582                 ubi_get_volume_info(desc, &vi);
 583                 err = ubiblock_remove(&vi);
 584                 break;
 585         }
 586
 587         default:
 588                 err = -ENOTTY;
 589                 break;
 590         }
 591         return err;
 592 }
 593
 594 /**
 595  * verify_mkvol_req - verify volume creation request.
 596  * @ubi: UBI device description object
 597  * @req: the request to check
 598  *
 599  * This function zero if the request is correct, and %-EINVAL if not.
 600  */
 601 static int verify_mkvol_req(const struct ubi_device *ubi,
 602                             const struct ubi_mkvol_req *req)
 603 {
 604         int n, err = -EINVAL;
 605
 606         if (req->bytes < 0 || req->alignment < 0 || req->vol_type < 0 ||
 607             req->name_len < 0)
 608                 goto bad;
 609
 610         if ((req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) &&
 611             req->vol_id != UBI_VOL_NUM_AUTO)
 612                 goto bad;
 613
 614         if (req->alignment == 0)
 615                 goto bad;
 616
 617         if (req->bytes == 0)
 618                 goto bad;
 619
 620         if (req->vol_type != UBI_DYNAMIC_VOLUME &&
 621             req->vol_type != UBI_STATIC_VOLUME)
 622                 goto bad;
 623
 624         if (req->alignment > ubi->leb_size)
 625                 goto bad;
 626
 627         n = req->alignment & (ubi->min_io_size - 1);
 628         if (req->alignment != 1 && n)
 629                 goto bad;
 630
 631         if (!req->name[0] || !req->name_len)
 632                 goto bad;
 633
 634         if (req->name_len > UBI_VOL_NAME_MAX) {
 635                 err = -ENAMETOOLONG;
 636                 goto bad;
 637         }
 638
 639         n = strnlen(req->name, req->name_len + 1);
 640         if (n != req->name_len)
 641                 goto bad;
 642
 643         return 0;
 644
 645 bad:
 646         ubi_err(ubi, "bad volume creation request");
 647         ubi_dump_mkvol_req(req);
 648         return err;
 649 }
 650
 651 /**
 652  * verify_rsvol_req - verify volume re-size request.
 653  * @ubi: UBI device description object
 654  * @req: the request to check
 655  *
 656  * This function returns zero if the request is correct, and %-EINVAL if not.
 657  */
 658 static int verify_rsvol_req(const struct ubi_device *ubi,
 659                             const struct ubi_rsvol_req *req)
 660 {
 661         if (req->bytes <= 0)
 662                 return -EINVAL;
 663
 664         if (req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots)
 665                 return -EINVAL;
 666
 667         return 0;
 668 }
 669
 670 /**
 671  * rename_volumes - rename UBI volumes.
 672  * @ubi: UBI device description object
 673  * @req: volumes re-name request
 674  *
 675  * This is a helper function for the volume re-name IOCTL which validates the
 676  * the request, opens the volume and calls corresponding volumes management
 677  * function. Returns zero in case of success and a negative error code in case
 678  * of failure.
 679  */
 680 static int rename_volumes(struct ubi_device *ubi,
 681                           struct ubi_rnvol_req *req)
 682 {
 683         int i, n, err;
 684         struct list_head rename_list;
 685         struct ubi_rename_entry *re, *re1;
 686
 687         if (req->count < 0 || req->count > UBI_MAX_RNVOL)
 688                 return -EINVAL;
 689
 690         if (req->count == 0)
 691                 return 0;
 692
 693         /* Validate volume IDs and names in the request */
 694         for (i = 0; i < req->count; i++) {
 695                 if (req->ents[i].vol_id < 0 ||
 696                     req->ents[i].vol_id >= ubi->vtbl_slots)
 697                         return -EINVAL;
 698                 if (req->ents[i].name_len < 0)
 699                         return -EINVAL;
 700                 if (req->ents[i].name_len > UBI_VOL_NAME_MAX)
 701                         return -ENAMETOOLONG;
 702                 req->ents[i].name[req->ents[i].name_len] = '\0';
 703                 n = strlen(req->ents[i].name);
 704                 if (n != req->ents[i].name_len)
 705                         return -EINVAL;
 706         }
 707
 708         /* Make sure volume IDs and names are unique */
 709         for (i = 0; i < req->count - 1; i++) {
 710                 for (n = i + 1; n < req->count; n++) {
 711                         if (req->ents[i].vol_id == req->ents[n].vol_id) {
 712                                 ubi_err(ubi, "duplicated volume id %d",
 713                                         req->ents[i].vol_id);
 714                                 return -EINVAL;
 715                         }
 716                         if (!strcmp(req->ents[i].name, req->ents[n].name)) {
 717                                 ubi_err(ubi, "duplicated volume name \"%s\"",
 718                                         req->ents[i].name);
 719                                 return -EINVAL;
 720                         }
 721                 }
 722         }
 723
 724         /* Create the re-name list */
 725         INIT_LIST_HEAD(&rename_list);
 726         for (i = 0; i < req->count; i++) {
 727                 int vol_id = req->ents[i].vol_id;
 728                 int name_len = req->ents[i].name_len;
 729                 const char *name = req->ents[i].name;
 730
 731                 re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
 732                 if (!re) {
 733                         err = -ENOMEM;
 734                         goto out_free;
 735                 }
 736
 737                 re->desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_READWRITE);
 738                 if (IS_ERR(re->desc)) {
 739                         err = PTR_ERR(re->desc);
 740                         ubi_err(ubi, "cannot open volume %d, error %d",
 741                                 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(ubi, "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 };