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                 kfree(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                 kfree(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 = kmalloc(tbuf_size, GFP_KERNEL);
 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         kfree(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 = kmalloc(tbuf_size, GFP_KERNEL);
 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         kfree(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
 417         void __user *argp = (void __user *)arg;
 418
 419         switch (cmd) {
 420         /* Volume update command */
 421         case UBI_IOCVOLUP:
 422         {
 423                 int64_t bytes, rsvd_bytes;
 424         #if CONFIG_BLB
 425         struct ubi_volume *backup_vol = ubi->volumes[vol_id2idx(ubi, UBI_BACKUP_VOLUME_ID)];
 426         #endif
 427                 if (!capable(CAP_SYS_RESOURCE)) {
 428                         err = -EPERM;
 429                         break;
 430                 }
 431
 432                 err = copy_from_user(&bytes, argp, sizeof(int64_t));
 433                 if (err) {
 434                         err = -EFAULT;
 435                         break;
 436                 }
 437
 438                 if (desc->mode == UBI_READONLY) {
 439                         err = -EROFS;
 440                         break;
 441                 }
 442
 443                 rsvd_bytes = (long long)vol->reserved_pebs *
 444                                         ubi->leb_size-vol->data_pad;
 445                 if (bytes < 0 || bytes > rsvd_bytes) {
 446                         err = -EINVAL;
 447                         break;
 448                 }
 449
 450                 err = get_exclusive(desc);
 451                 if (err < 0)
 452                         break;
 453
 454                 err = ubi_start_update(ubi, vol, bytes);
 455                 if (bytes == 0)
 456                         revoke_exclusive(desc, UBI_READWRITE);
 457                 #if CONFIG_BLB
 458         ubi_eba_unmap_leb(ubi, backup_vol, 0);
 459         ubi_eba_unmap_leb(ubi, backup_vol, 1);
 460                 #endif
 461                 break;
 462         }
 463
 464         /* Atomic logical eraseblock change command */
 465         case UBI_IOCEBCH:
 466         {
 467                 struct ubi_leb_change_req req;
 468
 469                 err = copy_from_user(&req, argp,
 470                                      sizeof(struct ubi_leb_change_req));
 471                 if (err) {
 472                         err = -EFAULT;
 473                         break;
 474                 }
 475
 476                 if (desc->mode == UBI_READONLY ||
 477                     vol->vol_type == UBI_STATIC_VOLUME) {
 478                         err = -EROFS;
 479                         break;
 480                 }
 481
 482                 /* Validate the request */
 483                 err = -EINVAL;
 484                 if (req.lnum < 0 || req.lnum >= vol->reserved_pebs ||
 485                     req.bytes < 0 || req.lnum >= vol->usable_leb_size)
 486                         break;
 487
 488                 err = get_exclusive(desc);
 489                 if (err < 0)
 490                         break;
 491
 492                 err = ubi_start_leb_change(ubi, vol, &req);
 493                 if (req.bytes == 0)
 494                         revoke_exclusive(desc, UBI_READWRITE);
 495                 break;
 496         }
 497
 498         /* Logical eraseblock erasure command */
 499         case UBI_IOCEBER:
 500         {
 501                 int32_t lnum;
 502
 503                 err = get_user(lnum, (__user int32_t *)argp);
 504                 if (err) {
 505                         err = -EFAULT;
 506                         break;
 507                 }
 508
 509                 if (desc->mode == UBI_READONLY ||
 510                     vol->vol_type == UBI_STATIC_VOLUME) {
 511                         err = -EROFS;
 512                         break;
 513                 }
 514
 515                 if (lnum < 0 || lnum >= vol->reserved_pebs) {
 516                         err = -EINVAL;
 517                         break;
 518                 }
 519
 520                 dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
 521                 err = ubi_eba_unmap_leb(ubi, vol, lnum);
 522                 if (err)
 523                         break;
 524
 525                 err = ubi_wl_flush(ubi, UBI_ALL, UBI_ALL);
 526                 break;
 527         }
 528
 529         /* Logical eraseblock map command */
 530         case UBI_IOCEBMAP:
 531         {
 532                 struct ubi_map_req req;
 533
 534                 err = copy_from_user(&req, argp, sizeof(struct ubi_map_req));
 535                 if (err) {
 536                         err = -EFAULT;
 537                         break;
 538                 }
 539                 err = ubi_leb_map(desc, req.lnum);
 540                 break;
 541         }
 542
 543         /* Logical eraseblock un-map command */
 544         case UBI_IOCEBUNMAP:
 545         {
 546                 int32_t lnum;
 547
 548                 err = get_user(lnum, (__user int32_t *)argp);
 549                 if (err) {
 550                         err = -EFAULT;
 551                         break;
 552                 }
 553 #ifdef MTK_IPOH_SUPPORT
 554                 ubi->ipoh_ops = 1;
 555 #endif
 556                 err = ubi_leb_unmap(desc, lnum);
 557 #ifdef MTK_IPOH_SUPPORT
 558                 ubi->ipoh_ops = 0;
 559 #endif
 560                 break;
 561         }
 562
 563         /* Check if logical eraseblock is mapped command */
 564         case UBI_IOCEBISMAP:
 565         {
 566                 int32_t lnum;
 567
 568                 err = get_user(lnum, (__user int32_t *)argp);
 569                 if (err) {
 570                         err = -EFAULT;
 571                         break;
 572                 }
 573                 err = ubi_is_mapped(desc, lnum);
 574                 break;
 575         }
 576
 577         /* Set volume property command */
 578         case UBI_IOCSETVOLPROP:
 579         {
 580                 struct ubi_set_vol_prop_req req;
 581
 582                 err = copy_from_user(&req, argp,
 583                                      sizeof(struct ubi_set_vol_prop_req));
 584                 if (err) {
 585                         err = -EFAULT;
 586                         break;
 587                 }
 588                 switch (req.property) {
 589                 case UBI_VOL_PROP_DIRECT_WRITE:
 590                         mutex_lock(&ubi->device_mutex);
 591                         desc->vol->direct_writes = !!req.value;
 592                         mutex_unlock(&ubi->device_mutex);
 593                         break;
 594                 default:
 595                         err = -EINVAL;
 596                         break;
 597                 }
 598                 break;
 599         }
 600         case UBI_IOCLBMAP:
 601         {
 602                 int LEB[2];
 603                 err = copy_from_user(LEB, argp, sizeof(int)*2);
 604                 if (err) {
 605                         err = -EFAULT;
 606                         break;
 607                 }
 608                 LEB[1] = desc->vol->eba_tbl[LEB[0]];
 609                 err = copy_to_user(argp, LEB, sizeof(int)*2);
 610                 if (err) {
 611                         err = -EFAULT;
 612                         break;
 613                 }
 614                 break;
 615         }
 616         default:
 617                 err = -ENOTTY;
 618                 break;
 619         }
 620         return err;
 621 }
 622
 623 /**
 624  * verify_mkvol_req - verify volume creation request.
 625  * @ubi: UBI device description object
 626  * @req: the request to check
 627  *
 628  * This function zero if the request is correct, and %-EINVAL if not.
 629  */
 630 static int verify_mkvol_req(const struct ubi_device *ubi,
 631                             const struct ubi_mkvol_req *req)
 632 {
 633         int n, err = -EINVAL;
 634
 635         if (req->bytes < 0 || req->alignment < 0 || req->vol_type < 0 ||
 636             req->name_len < 0)
 637                 goto bad;
 638
 639         if ((req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) &&
 640             req->vol_id != UBI_VOL_NUM_AUTO)
 641                 goto bad;
 642
 643         if (req->alignment == 0)
 644                 goto bad;
 645
 646         if (req->bytes == 0)
 647                 goto bad;
 648
 649         if (req->vol_type != UBI_DYNAMIC_VOLUME &&
 650             req->vol_type != UBI_STATIC_VOLUME)
 651                 goto bad;
 652
 653         if (req->alignment > ubi->leb_size)
 654                 goto bad;
 655
 656         n = req->alignment & (ubi->min_io_size - 1);
 657         if (req->alignment != 1 && n)
 658                 goto bad;
 659
 660         if (!req->name[0] || !req->name_len)
 661                 goto bad;
 662
 663         if (req->name_len > UBI_VOL_NAME_MAX) {
 664                 err = -ENAMETOOLONG;
 665                 goto bad;
 666         }
 667
 668         n = strnlen(req->name, req->name_len + 1);
 669         if (n != req->name_len)
 670                 goto bad;
 671
 672         return 0;
 673
 674 bad:
 675         ubi_err("bad volume creation request");
 676         ubi_dump_mkvol_req(req);
 677         return err;
 678 }
 679
 680 /**
 681  * verify_rsvol_req - verify volume re-size request.
 682  * @ubi: UBI device description object
 683  * @req: the request to check
 684  *
 685  * This function returns zero if the request is correct, and %-EINVAL if not.
 686  */
 687 static int verify_rsvol_req(const struct ubi_device *ubi,
 688                             const struct ubi_rsvol_req *req)
 689 {
 690         if (req->bytes <= 0)
 691                 return -EINVAL;
 692
 693         if (req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots)
 694                 return -EINVAL;
 695
 696         return 0;
 697 }
 698
 699 /**
 700  * rename_volumes - rename UBI volumes.
 701  * @ubi: UBI device description object
 702  * @req: volumes re-name request
 703  *
 704  * This is a helper function for the volume re-name IOCTL which validates the
 705  * the request, opens the volume and calls corresponding volumes management
 706  * function. Returns zero in case of success and a negative error code in case
 707  * of failure.
 708  */
 709 static int rename_volumes(struct ubi_device *ubi,
 710                           struct ubi_rnvol_req *req)
 711 {
 712         int i, n, err;
 713         struct list_head rename_list;
 714         struct ubi_rename_entry *re, *re1;
 715
 716         if (req->count < 0 || req->count > UBI_MAX_RNVOL)
 717                 return -EINVAL;
 718
 719         if (req->count == 0)
 720                 return 0;
 721
 722         /* Validate volume IDs and names in the request */
 723         for (i = 0; i < req->count; i++) {
 724                 if (req->ents[i].vol_id < 0 ||
 725                     req->ents[i].vol_id >= ubi->vtbl_slots)
 726                         return -EINVAL;
 727                 if (req->ents[i].name_len < 0)
 728                         return -EINVAL;
 729                 if (req->ents[i].name_len > UBI_VOL_NAME_MAX)
 730                         return -ENAMETOOLONG;
 731                 req->ents[i].name[req->ents[i].name_len] = '\0';
 732                 n = strlen(req->ents[i].name);
 733                 if (n != req->ents[i].name_len)
 734                         err = -EINVAL;
 735         }
 736
 737         /* Make sure volume IDs and names are unique */
 738         for (i = 0; i < req->count - 1; i++) {
 739                 for (n = i + 1; n < req->count; n++) {
 740                         if (req->ents[i].vol_id == req->ents[n].vol_id) {
 741                                 ubi_err("duplicated volume id %d",
 742                                         req->ents[i].vol_id);
 743                                 return -EINVAL;
 744                         }
 745                         if (!strcmp(req->ents[i].name, req->ents[n].name)) {
 746                                 ubi_err("duplicated volume name \"%s\"",
 747                                         req->ents[i].name);
 748                                 return -EINVAL;
 749                         }
 750                 }
 751         }
 752
 753         /* Create the re-name list */
 754         INIT_LIST_HEAD(&rename_list);
 755         for (i = 0; i < req->count; i++) {
 756                 int vol_id = req->ents[i].vol_id;
 757                 int name_len = req->ents[i].name_len;
 758                 const char *name = req->ents[i].name;
 759
 760                 re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
 761                 if (!re) {
 762                         err = -ENOMEM;
 763                         goto out_free;
 764                 }
 765
 766                 re->desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
 767                 if (IS_ERR(re->desc)) {
 768                         err = PTR_ERR(re->desc);
 769                         ubi_err("cannot open volume %d, error %d", vol_id, err);
 770                         kfree(re);
 771                         goto out_free;
 772                 }
 773
 774                 /* Skip this re-naming if the name does not really change */
 775                 if (re->desc->vol->name_len == name_len &&
 776                     !memcmp(re->desc->vol->name, name, name_len)) {
 777                         ubi_close_volume(re->desc);
 778                         kfree(re);
 779                         continue;
 780                 }
 781
 782                 re->new_name_len = name_len;
 783                 memcpy(re->new_name, name, name_len);
 784                 list_add_tail(&re->list, &rename_list);
 785                 dbg_gen("will rename volume %d from \"%s\" to \"%s\"",
 786                         vol_id, re->desc->vol->name, name);
 787         }
 788
 789         if (list_empty(&rename_list))
 790                 return 0;
 791
 792         /* Find out the volumes which have to be removed */
 793         list_for_each_entry(re, &rename_list, list) {
 794                 struct ubi_volume_desc *desc;
 795                 int no_remove_needed = 0;
 796
 797                 /*
 798                  * Volume @re->vol_id is going to be re-named to
 799                  * @re->new_name, while its current name is @name. If a volume
 800                  * with name @re->new_name currently exists, it has to be
 801                  * removed, unless it is also re-named in the request (@req).
 802                  */
 803                 list_for_each_entry(re1, &rename_list, list) {
 804                         if (re->new_name_len == re1->desc->vol->name_len &&
 805                             !memcmp(re->new_name, re1->desc->vol->name,
 806                                     re1->desc->vol->name_len)) {
 807                                 no_remove_needed = 1;
 808                                 break;
 809                         }
 810                 }
 811
 812                 if (no_remove_needed)
 813                         continue;
 814
 815                 /*
 816                  * It seems we need to remove volume with name @re->new_name,
 817                  * if it exists.
 818                  */
 819                 desc = ubi_open_volume_nm(ubi->ubi_num, re->new_name,
 820                                           UBI_EXCLUSIVE);
 821                 if (IS_ERR(desc)) {
 822                         err = PTR_ERR(desc);
 823                         if (err == -ENODEV)
 824                                 /* Re-naming into a non-existing volume name */
 825                                 continue;
 826
 827                         /* The volume exists but busy, or an error occurred */
 828                         ubi_err("cannot open volume \"%s\", error %d",
 829                                 re->new_name, err);
 830                         goto out_free;
 831                 }
 832
 833                 re1 = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
 834                 if (!re1) {
 835                         err = -ENOMEM;
 836                         ubi_close_volume(desc);
 837                         goto out_free;
 838                 }
 839
 840                 re1->remove = 1;
 841                 re1->desc = desc;
 842                 list_add(&re1->list, &rename_list);
 843                 dbg_gen("will remove volume %d, name \"%s\"",
 844                         re1->desc->vol->vol_id, re1->desc->vol->name);
 845         }
 846
 847         mutex_lock(&ubi->device_mutex);
 848         err = ubi_rename_volumes(ubi, &rename_list);
 849         mutex_unlock(&ubi->device_mutex);
 850
 851 out_free:
 852         list_for_each_entry_safe(re, re1, &rename_list, list) {
 853                 ubi_close_volume(re->desc);
 854                 list_del(&re->list);
 855                 kfree(re);
 856         }
 857         return err;
 858 }
 859
 860 static long ubi_cdev_ioctl(struct file *file, unsigned int cmd,
 861                            unsigned long arg)
 862 {
 863         int err = 0;
 864         struct ubi_device *ubi;
 865         struct ubi_volume_desc *desc;
 866         void __user *argp = (void __user *)arg;
 867
 868         if (!capable(CAP_SYS_RESOURCE))
 869                 return -EPERM;
 870
 871         ubi = ubi_get_by_major(imajor(file->f_mapping->host));
 872         if (!ubi)
 873                 return -ENODEV;
 874
 875         switch (cmd) {
 876         /* Create volume command */
 877         case UBI_IOCMKVOL:
 878         {
 879                 struct ubi_mkvol_req req;
 880
 881                 dbg_gen("create volume");
 882                 err = copy_from_user(&req, argp, sizeof(struct ubi_mkvol_req));
 883                 if (err) {
 884                         err = -EFAULT;
 885                         break;
 886                 }
 887
 888                 err = verify_mkvol_req(ubi, &req);
 889                 if (err)
 890                         break;
 891
 892                 mutex_lock(&ubi->device_mutex);
 893                 err = ubi_create_volume(ubi, &req);
 894                 mutex_unlock(&ubi->device_mutex);
 895                 if (err)
 896                         break;
 897
 898                 err = put_user(req.vol_id, (__user int32_t *)argp);
 899                 if (err)
 900                         err = -EFAULT;
 901
 902                 break;
 903         }
 904
 905         /* Remove volume command */
 906         case UBI_IOCRMVOL:
 907         {
 908                 int vol_id;
 909
 910                 dbg_gen("remove volume");
 911                 err = get_user(vol_id, (__user int32_t *)argp);
 912                 if (err) {
 913                         err = -EFAULT;
 914                         break;
 915                 }
 916
 917                 desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
 918                 if (IS_ERR(desc)) {
 919                         err = PTR_ERR(desc);
 920                         break;
 921                 }
 922
 923                 mutex_lock(&ubi->device_mutex);
 924                 err = ubi_remove_volume(desc, 0);
 925                 mutex_unlock(&ubi->device_mutex);
 926
 927                 /*
 928                  * The volume is deleted (unless an error occurred), and the
 929                  * 'struct ubi_volume' object will be freed when
 930                  * 'ubi_close_volume()' will call 'put_device()'.
 931                  */
 932                 ubi_close_volume(desc);
 933                 break;
 934         }
 935
 936         /* Re-size volume command */
 937         case UBI_IOCRSVOL:
 938         {
 939                 int pebs;
 940                 struct ubi_rsvol_req req;
 941
 942                 dbg_gen("re-size volume");
 943                 err = copy_from_user(&req, argp, sizeof(struct ubi_rsvol_req));
 944                 if (err) {
 945                         err = -EFAULT;
 946                         break;
 947                 }
 948
 949                 err = verify_rsvol_req(ubi, &req);
 950                 if (err)
 951                         break;
 952
 953                 desc = ubi_open_volume(ubi->ubi_num, req.vol_id, UBI_EXCLUSIVE);
 954                 if (IS_ERR(desc)) {
 955                         err = PTR_ERR(desc);
 956                         break;
 957                 }
 958
 959                 pebs = div_u64(req.bytes + desc->vol->usable_leb_size - 1,
 960                                desc->vol->usable_leb_size);
 961
 962                 mutex_lock(&ubi->device_mutex);
 963                 err = ubi_resize_volume(desc, pebs);
 964                 mutex_unlock(&ubi->device_mutex);
 965                 ubi_close_volume(desc);
 966                 break;
 967         }
 968
 969         /* Re-name volumes command */
 970         case UBI_IOCRNVOL:
 971         {
 972                 struct ubi_rnvol_req *req;
 973
 974                 dbg_gen("re-name volumes");
 975                 req = kmalloc(sizeof(struct ubi_rnvol_req), GFP_KERNEL);
 976                 if (!req) {
 977                         err = -ENOMEM;
 978                         break;
 979                 };
 980
 981                 err = copy_from_user(req, argp, sizeof(struct ubi_rnvol_req));
 982                 if (err) {
 983                         err = -EFAULT;
 984                         kfree(req);
 985                         break;
 986                 }
 987
 988                 err = rename_volumes(ubi, req);
 989                 kfree(req);
 990                 break;
 991         }
 992
 993         default:
 994                 err = -ENOTTY;
 995                 break;
 996         }
 997
 998         ubi_put_device(ubi);
 999         return err;
1000 }
1001
1002 static long ctrl_cdev_ioctl(struct file *file, unsigned int cmd,
1003                             unsigned long arg)
1004 {
1005         int err = 0;
1006         void __user *argp = (void __user *)arg;
1007
1008         if (!capable(CAP_SYS_RESOURCE))
1009                 return -EPERM;
1010
1011         switch (cmd) {
1012         /* Attach an MTD device command */
1013         case UBI_IOCATT:
1014         {
1015                 struct ubi_attach_req req;
1016                 struct mtd_info *mtd;
1017
1018                 dbg_gen("attach MTD device");
1019                 err = copy_from_user(&req, argp, sizeof(struct ubi_attach_req));
1020                 if (err) {
1021                         err = -EFAULT;
1022                         break;
1023                 }
1024
1025                 if (req.mtd_num < 0 ||
1026                     (req.ubi_num < 0 && req.ubi_num != UBI_DEV_NUM_AUTO)) {
1027                         err = -EINVAL;
1028                         break;
1029                 }
1030
1031                 mtd = get_mtd_device(NULL, req.mtd_num);
1032                 if (IS_ERR(mtd)) {
1033                         err = PTR_ERR(mtd);
1034                         break;
1035                 }
1036
1037                 /*
1038                  * Note, further request verification is done by
1039                  * 'ubi_attach_mtd_dev()'.
1040                  */
1041                 mutex_lock(&ubi_devices_mutex);
1042                 err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset,
1043                                          req.max_beb_per1024);
1044                 mutex_unlock(&ubi_devices_mutex);
1045                 if (err < 0)
1046                         put_mtd_device(mtd);
1047                 else
1048                         /* @err contains UBI device number */
1049                         err = put_user(err, (__user int32_t *)argp);
1050
1051                 break;
1052         }
1053
1054         /* Detach an MTD device command */
1055         case UBI_IOCDET:
1056         {
1057                 int ubi_num;
1058
1059                 dbg_gen("detach MTD device");
1060                 err = get_user(ubi_num, (__user int32_t *)argp);
1061                 if (err) {
1062                         err = -EFAULT;
1063                         break;
1064                 }
1065
1066                 mutex_lock(&ubi_devices_mutex);
1067                 err = ubi_detach_mtd_dev(ubi_num, 0);
1068                 mutex_unlock(&ubi_devices_mutex);
1069                 break;
1070         }
1071
1072         default:
1073                 err = -ENOTTY;
1074                 break;
1075         }
1076
1077         return err;
1078 }
1079
1080 #ifdef CONFIG_COMPAT
1081 static long vol_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1082                                   unsigned long arg)
1083 {
1084         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1085
1086         return vol_cdev_ioctl(file, cmd, translated_arg);
1087 }
1088
1089 static long ubi_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1090                                   unsigned long arg)
1091 {
1092         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1093
1094         return ubi_cdev_ioctl(file, cmd, translated_arg);
1095 }
1096
1097 static long ctrl_cdev_compat_ioctl(struct file *file, unsigned int cmd,
1098                                    unsigned long arg)
1099 {
1100         unsigned long translated_arg = (unsigned long)compat_ptr(arg);
1101
1102         return ctrl_cdev_ioctl(file, cmd, translated_arg);
1103 }
1104 #else
1105 #define vol_cdev_compat_ioctl  NULL
1106 #define ubi_cdev_compat_ioctl  NULL
1107 #define ctrl_cdev_compat_ioctl NULL
1108 #endif
1109
1110 /* UBI volume character device operations */
1111 const struct file_operations ubi_vol_cdev_operations = {
1112         .owner          = THIS_MODULE,
1113         .open           = vol_cdev_open,
1114         .release        = vol_cdev_release,
1115         .llseek         = vol_cdev_llseek,
1116         .read           = vol_cdev_read,
1117         .write          = vol_cdev_write,
1118         .fsync          = vol_cdev_fsync,
1119         .unlocked_ioctl = vol_cdev_ioctl,
1120         .compat_ioctl   = vol_cdev_compat_ioctl,
1121 };
1122
1123 /* UBI character device operations */
1124 const struct file_operations ubi_cdev_operations = {
1125         .owner          = THIS_MODULE,
1126         .llseek         = no_llseek,
1127         .unlocked_ioctl = ubi_cdev_ioctl,
1128         .compat_ioctl   = ubi_cdev_compat_ioctl,
1129 };
1130
1131 /* UBI control character device operations */
1132 const struct file_operations ubi_ctrl_cdev_operations = {
1133         .owner          = THIS_MODULE,
1134         .unlocked_ioctl = ctrl_cdev_ioctl,
1135         .compat_ioctl   = ctrl_cdev_compat_ioctl,
1136         .llseek         = no_llseek,
1137 };