git.oblomov.eu Git - linux-2.6/blob - drivers/mtd/ubi/cdev.c

   1 /*
   2  * Copyright (c) International Business Machines Corp., 2006
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
  12  * the GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  17  *
  18  * Author: Artem Bityutskiy (Битюцкий Артём)
  19  */
  20
  21 /*
  22  * This file includes implementation of UBI character device operations.
  23  *
  24  * There are two kinds of character devices in UBI: UBI character devices and
  25  * UBI volume character devices. UBI character devices allow users to
  26  * manipulate whole volumes: create, remove, and re-size them. Volume character
  27  * devices provide volume I/O capabilities.
  28  *
  29  * Major and minor numbers are assigned dynamically to both UBI and volume
  30  * character devices.
  31  *
  32  * Well, there is the third kind of character devices - the UBI control
  33  * character device, which allows to manipulate by UBI devices - create and
  34  * delete them. In other words, it is used for attaching and detaching MTD
  35  * devices.
  36  */
  37
  38 #include <linux/module.h>
  39 #include <linux/stat.h>
  40 #include <linux/ioctl.h>
  41 #include <linux/capability.h>
  42 #include <linux/uaccess.h>
  43 #include <linux/smp_lock.h>
  44 #include <mtd/ubi-user.h>
  45 #include <asm/div64.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         lock_kernel();
 108         ubi_num = ubi_major2num(imajor(inode));
 109         if (ubi_num < 0) {
 110                 unlock_kernel();
 111                 return ubi_num;
 112         }
 113
 114         if (file->f_mode & FMODE_WRITE)
 115                 mode = UBI_READWRITE;
 116         else
 117                 mode = UBI_READONLY;
 118
 119         dbg_gen("open volume %d, mode %d", vol_id, mode);
 120
 121         desc = ubi_open_volume(ubi_num, vol_id, mode);
 122         unlock_kernel();
 123         if (IS_ERR(desc))
 124                 return PTR_ERR(desc);
 125
 126         file->private_data = desc;
 127         return 0;
 128 }
 129
 130 static int vol_cdev_release(struct inode *inode, struct file *file)
 131 {
 132         struct ubi_volume_desc *desc = file->private_data;
 133         struct ubi_volume *vol = desc->vol;
 134
 135         dbg_gen("release volume %d, mode %d", vol->vol_id, desc->mode);
 136
 137         if (vol->updating) {
 138                 ubi_warn("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"
 145                         " for volume %d:%d, cancel", vol->upd_received,
 146                         vol->upd_bytes, vol->ubi->ubi_num, 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         loff_t new_offset;
 160
 161         if (vol->updating) {
 162                  /* Update is in progress, seeking is prohibited */
 163                 dbg_err("updating");
 164                 return -EBUSY;
 165         }
 166
 167         switch (origin) {
 168         case 0: /* SEEK_SET */
 169                 new_offset = offset;
 170                 break;
 171         case 1: /* SEEK_CUR */
 172                 new_offset = file->f_pos + offset;
 173                 break;
 174         case 2: /* SEEK_END */
 175                 new_offset = vol->used_bytes + offset;
 176                 break;
 177         default:
 178                 return -EINVAL;
 179         }
 180
 181         if (new_offset < 0 || new_offset > vol->used_bytes) {
 182                 dbg_err("bad seek %lld", new_offset);
 183                 return -EINVAL;
 184         }
 185
 186         dbg_gen("seek volume %d, offset %lld, origin %d, new offset %lld",
 187                 vol->vol_id, offset, origin, new_offset);
 188
 189         file->f_pos = new_offset;
 190         return new_offset;
 191 }
 192
 193 static ssize_t vol_cdev_read(struct file *file, __user char *buf, size_t count,
 194                              loff_t *offp)
 195 {
 196         struct ubi_volume_desc *desc = file->private_data;
 197         struct ubi_volume *vol = desc->vol;
 198         struct ubi_device *ubi = vol->ubi;
 199         int err, lnum, off, len,  tbuf_size;
 200         size_t count_save = count;
 201         void *tbuf;
 202         uint64_t tmp;
 203
 204         dbg_gen("read %zd bytes from offset %lld of volume %d",
 205                 count, *offp, vol->vol_id);
 206
 207         if (vol->updating) {
 208                 dbg_err("updating");
 209                 return -EBUSY;
 210         }
 211         if (vol->upd_marker) {
 212                 dbg_err("damaged volume, update marker is set");
 213                 return -EBADF;
 214         }
 215         if (*offp == vol->used_bytes || count == 0)
 216                 return 0;
 217
 218         if (vol->corrupted)
 219                 dbg_gen("read from corrupted volume %d", vol->vol_id);
 220
 221         if (*offp + count > vol->used_bytes)
 222                 count_save = count = vol->used_bytes - *offp;
 223
 224         tbuf_size = vol->usable_leb_size;
 225         if (count < tbuf_size)
 226                 tbuf_size = ALIGN(count, ubi->min_io_size);
 227         tbuf = vmalloc(tbuf_size);
 228         if (!tbuf)
 229                 return -ENOMEM;
 230
 231         len = count > tbuf_size ? tbuf_size : count;
 232
 233         tmp = *offp;
 234         off = do_div(tmp, vol->usable_leb_size);
 235         lnum = tmp;
 236
 237         do {
 238                 cond_resched();
 239
 240                 if (off + len >= vol->usable_leb_size)
 241                         len = vol->usable_leb_size - off;
 242
 243                 err = ubi_eba_read_leb(ubi, vol, lnum, tbuf, off, len, 0);
 244                 if (err)
 245                         break;
 246
 247                 off += len;
 248                 if (off == vol->usable_leb_size) {
 249                         lnum += 1;
 250                         off -= vol->usable_leb_size;
 251                 }
 252
 253                 count -= len;
 254                 *offp += len;
 255
 256                 err = copy_to_user(buf, tbuf, len);
 257                 if (err) {
 258                         err = -EFAULT;
 259                         break;
 260                 }
 261
 262                 buf += len;
 263                 len = count > tbuf_size ? tbuf_size : count;
 264         } while (count);
 265
 266         vfree(tbuf);
 267         return err ? err : count_save - count;
 268 }
 269
 270 #ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
 271
 272 /*
 273  * This function allows to directly write to dynamic UBI volumes, without
 274  * issuing the volume update operation. Available only as a debugging feature.
 275  * Very useful for testing UBI.
 276  */
 277 static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
 278                                      size_t count, loff_t *offp)
 279 {
 280         struct ubi_volume_desc *desc = file->private_data;
 281         struct ubi_volume *vol = desc->vol;
 282         struct ubi_device *ubi = vol->ubi;
 283         int lnum, off, len, tbuf_size, err = 0;
 284         size_t count_save = count;
 285         char *tbuf;
 286         uint64_t tmp;
 287
 288         dbg_gen("requested: write %zd bytes to offset %lld of volume %u",
 289                 count, *offp, vol->vol_id);
 290
 291         if (vol->vol_type == UBI_STATIC_VOLUME)
 292                 return -EROFS;
 293
 294         tmp = *offp;
 295         off = do_div(tmp, vol->usable_leb_size);
 296         lnum = tmp;
 297
 298         if (off & (ubi->min_io_size - 1)) {
 299                 dbg_err("unaligned position");
 300                 return -EINVAL;
 301         }
 302
 303         if (*offp + count > vol->used_bytes)
 304                 count_save = count = vol->used_bytes - *offp;
 305
 306         /* We can write only in fractions of the minimum I/O unit */
 307         if (count & (ubi->min_io_size - 1)) {
 308                 dbg_err("unaligned write length");
 309                 return -EINVAL;
 310         }
 311
 312         tbuf_size = vol->usable_leb_size;
 313         if (count < tbuf_size)
 314                 tbuf_size = ALIGN(count, ubi->min_io_size);
 315         tbuf = vmalloc(tbuf_size);
 316         if (!tbuf)
 317                 return -ENOMEM;
 318
 319         len = count > tbuf_size ? tbuf_size : count;
 320
 321         while (count) {
 322                 cond_resched();
 323
 324                 if (off + len >= vol->usable_leb_size)
 325                         len = vol->usable_leb_size - off;
 326
 327                 err = copy_from_user(tbuf, buf, len);
 328                 if (err) {
 329                         err = -EFAULT;
 330                         break;
 331                 }
 332
 333                 err = ubi_eba_write_leb(ubi, vol, lnum, tbuf, off, len,
 334                                         UBI_UNKNOWN);
 335                 if (err)
 336                         break;
 337
 338                 off += len;
 339                 if (off == vol->usable_leb_size) {
 340                         lnum += 1;
 341                         off -= vol->usable_leb_size;
 342                 }
 343
 344                 count -= len;
 345                 *offp += len;
 346                 buf += len;
 347                 len = count > tbuf_size ? tbuf_size : count;
 348         }
 349
 350         vfree(tbuf);
 351         return err ? err : count_save - count;
 352 }
 353
 354 #else
 355 #define vol_cdev_direct_write(file, buf, count, offp) (-EPERM)
 356 #endif /* CONFIG_MTD_UBI_DEBUG_USERSPACE_IO */
 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_gluebi_updated(vol);
 403                 revoke_exclusive(desc, UBI_READWRITE);
 404         }
 405
 406         return count;
 407 }
 408
 409 static int vol_cdev_ioctl(struct inode *inode, struct file *file,
 410                           unsigned int cmd, unsigned long arg)
 411 {
 412         int err = 0;
 413         struct ubi_volume_desc *desc = file->private_data;
 414         struct ubi_volume *vol = desc->vol;
 415         struct ubi_device *ubi = vol->ubi;
 416         void __user *argp = (void __user *)arg;
 417
 418         switch (cmd) {
 419         /* Volume update command */
 420         case UBI_IOCVOLUP:
 421         {
 422                 int64_t bytes, rsvd_bytes;
 423
 424                 if (!capable(CAP_SYS_RESOURCE)) {
 425                         err = -EPERM;
 426                         break;
 427                 }
 428
 429                 err = copy_from_user(&bytes, argp, sizeof(int64_t));
 430                 if (err) {
 431                         err = -EFAULT;
 432                         break;
 433                 }
 434
 435                 if (desc->mode == UBI_READONLY) {
 436                         err = -EROFS;
 437                         break;
 438                 }
 439
 440                 rsvd_bytes = (long long)vol->reserved_pebs *
 441                                         ubi->leb_size-vol->data_pad;
 442                 if (bytes < 0 || bytes > rsvd_bytes) {
 443                         err = -EINVAL;
 444                         break;
 445                 }
 446
 447                 err = get_exclusive(desc);
 448                 if (err < 0)
 449                         break;
 450
 451                 err = ubi_start_update(ubi, vol, bytes);
 452                 if (bytes == 0)
 453                         revoke_exclusive(desc, UBI_READWRITE);
 454                 break;
 455         }
 456
 457         /* Atomic logical eraseblock change command */
 458         case UBI_IOCEBCH:
 459         {
 460                 struct ubi_leb_change_req req;
 461
 462                 err = copy_from_user(&req, argp,
 463                                      sizeof(struct ubi_leb_change_req));
 464                 if (err) {
 465                         err = -EFAULT;
 466                         break;
 467                 }
 468
 469                 if (desc->mode == UBI_READONLY ||
 470                     vol->vol_type == UBI_STATIC_VOLUME) {
 471                         err = -EROFS;
 472                         break;
 473                 }
 474
 475                 /* Validate the request */
 476                 err = -EINVAL;
 477                 if (req.lnum < 0 || req.lnum >= vol->reserved_pebs ||
 478                     req.bytes < 0 || req.lnum >= vol->usable_leb_size)
 479                         break;
 480                 if (req.dtype != UBI_LONGTERM && req.dtype != UBI_SHORTTERM &&
 481                     req.dtype != UBI_UNKNOWN)
 482                         break;
 483
 484                 err = get_exclusive(desc);
 485                 if (err < 0)
 486                         break;
 487
 488                 err = ubi_start_leb_change(ubi, vol, &req);
 489                 if (req.bytes == 0)
 490                         revoke_exclusive(desc, UBI_READWRITE);
 491                 break;
 492         }
 493
 494 #ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
 495         /* Logical eraseblock erasure command */
 496         case UBI_IOCEBER:
 497         {
 498                 int32_t lnum;
 499
 500                 err = get_user(lnum, (__user int32_t *)argp);
 501                 if (err) {
 502                         err = -EFAULT;
 503                         break;
 504                 }
 505
 506                 if (desc->mode == UBI_READONLY ||
 507                     vol->vol_type == UBI_STATIC_VOLUME) {
 508                         err = -EROFS;
 509                         break;
 510                 }
 511
 512                 if (lnum < 0 || lnum >= vol->reserved_pebs) {
 513                         err = -EINVAL;
 514                         break;
 515                 }
 516
 517                 dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
 518                 err = ubi_eba_unmap_leb(ubi, vol, lnum);
 519                 if (err)
 520                         break;
 521
 522                 err = ubi_wl_flush(ubi);
 523                 break;
 524         }
 525 #endif
 526
 527         default:
 528                 err = -ENOTTY;
 529                 break;
 530         }
 531
 532         return err;
 533 }
 534
 535 /**
 536  * verify_mkvol_req - verify volume creation request.
 537  * @ubi: UBI device description object
 538  * @req: the request to check
 539  *
 540  * This function zero if the request is correct, and %-EINVAL if not.
 541  */
 542 static int verify_mkvol_req(const struct ubi_device *ubi,
 543                             const struct ubi_mkvol_req *req)
 544 {
 545         int n, err = -EINVAL;
 546
 547         if (req->bytes < 0 || req->alignment < 0 || req->vol_type < 0 ||
 548             req->name_len < 0)
 549                 goto bad;
 550
 551         if ((req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) &&
 552             req->vol_id != UBI_VOL_NUM_AUTO)
 553                 goto bad;
 554
 555         if (req->alignment == 0)
 556                 goto bad;
 557
 558         if (req->bytes == 0)
 559                 goto bad;
 560
 561         if (req->vol_type != UBI_DYNAMIC_VOLUME &&
 562             req->vol_type != UBI_STATIC_VOLUME)
 563                 goto bad;
 564
 565         if (req->alignment > ubi->leb_size)
 566                 goto bad;
 567
 568         n = req->alignment & (ubi->min_io_size - 1);
 569         if (req->alignment != 1 && n)
 570                 goto bad;
 571
 572         if (req->name_len > UBI_VOL_NAME_MAX) {
 573                 err = -ENAMETOOLONG;
 574                 goto bad;
 575         }
 576
 577         n = strnlen(req->name, req->name_len + 1);
 578         if (n != req->name_len)
 579                 goto bad;
 580
 581         return 0;
 582
 583 bad:
 584         dbg_err("bad volume creation request");
 585         ubi_dbg_dump_mkvol_req(req);
 586         return err;
 587 }
 588
 589 /**
 590  * verify_rsvol_req - verify volume re-size request.
 591  * @ubi: UBI device description object
 592  * @req: the request to check
 593  *
 594  * This function returns zero if the request is correct, and %-EINVAL if not.
 595  */
 596 static int verify_rsvol_req(const struct ubi_device *ubi,
 597                             const struct ubi_rsvol_req *req)
 598 {
 599         if (req->bytes <= 0)
 600                 return -EINVAL;
 601
 602         if (req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots)
 603                 return -EINVAL;
 604
 605         return 0;
 606 }
 607
 608 /**
 609  * rename_volumes - rename UBI volumes.
 610  * @ubi: UBI device description object
 611  * @req: volumes re-name request
 612  *
 613  * This is a helper function for the volume re-name IOCTL which validates the
 614  * the request, opens the volume and calls corresponding volumes management
 615  * function. Returns zero in case of success and a negative error code in case
 616  * of failure.
 617  */
 618 static int rename_volumes(struct ubi_device *ubi,
 619                           struct ubi_rnvol_req *req)
 620 {
 621         int i, n, err;
 622         struct list_head rename_list;
 623         struct ubi_rename_entry *re, *re1;
 624
 625         if (req->count < 0 || req->count > UBI_MAX_RNVOL)
 626                 return -EINVAL;
 627
 628         if (req->count == 0)
 629                 return 0;
 630
 631         /* Validate volume IDs and names in the request */
 632         for (i = 0; i < req->count; i++) {
 633                 if (req->ents[i].vol_id < 0 ||
 634                     req->ents[i].vol_id >= ubi->vtbl_slots)
 635                         return -EINVAL;
 636                 if (req->ents[i].name_len < 0)
 637                         return -EINVAL;
 638                 if (req->ents[i].name_len > UBI_VOL_NAME_MAX)
 639                         return -ENAMETOOLONG;
 640                 req->ents[i].name[req->ents[i].name_len] = '\0';
 641                 n = strlen(req->ents[i].name);
 642                 if (n != req->ents[i].name_len)
 643                         err = -EINVAL;
 644         }
 645
 646         /* Make sure volume IDs and names are unique */
 647         for (i = 0; i < req->count - 1; i++) {
 648                 for (n = i + 1; n < req->count; n++) {
 649                         if (req->ents[i].vol_id == req->ents[n].vol_id) {
 650                                 dbg_err("duplicated volume id %d",
 651                                         req->ents[i].vol_id);
 652                                 return -EINVAL;
 653                         }
 654                         if (!strcmp(req->ents[i].name, req->ents[n].name)) {
 655                                 dbg_err("duplicated volume name \"%s\"",
 656                                         req->ents[i].name);
 657                                 return -EINVAL;
 658                         }
 659                 }
 660         }
 661
 662         /* Create the re-name list */
 663         INIT_LIST_HEAD(&rename_list);
 664         for (i = 0; i < req->count; i++) {
 665                 int vol_id = req->ents[i].vol_id;
 666                 int name_len = req->ents[i].name_len;
 667                 const char *name = req->ents[i].name;
 668
 669                 re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
 670                 if (!re) {
 671                         err = -ENOMEM;
 672                         goto out_free;
 673                 }
 674
 675                 re->desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
 676                 if (IS_ERR(re->desc)) {
 677                         err = PTR_ERR(re->desc);
 678                         dbg_err("cannot open volume %d, error %d", vol_id, err);
 679                         kfree(re);
 680                         goto out_free;
 681                 }
 682
 683                 /* Skip this re-naming if the name does not really change */
 684                 if (re->desc->vol->name_len == name_len &&
 685                     !memcmp(re->desc->vol->name, name, name_len)) {
 686                         ubi_close_volume(re->desc);
 687                         kfree(re);
 688                         continue;
 689                 }
 690
 691                 re->new_name_len = name_len;
 692                 memcpy(re->new_name, name, name_len);
 693                 list_add_tail(&re->list, &rename_list);
 694                 dbg_msg("will rename volume %d from \"%s\" to \"%s\"",
 695                         vol_id, re->desc->vol->name, name);
 696         }
 697
 698         if (list_empty(&rename_list))
 699                 return 0;
 700
 701         /* Find out the volumes which have to be removed */
 702         list_for_each_entry(re, &rename_list, list) {
 703                 struct ubi_volume_desc *desc;
 704                 int no_remove_needed = 0;
 705
 706                 /*
 707                  * Volume @re->vol_id is going to be re-named to
 708                  * @re->new_name, while its current name is @name. If a volume
 709                  * with name @re->new_name currently exists, it has to be
 710                  * removed, unless it is also re-named in the request (@req).
 711                  */
 712                 list_for_each_entry(re1, &rename_list, list) {
 713                         if (re->new_name_len == re1->desc->vol->name_len &&
 714                             !memcmp(re->new_name, re1->desc->vol->name,
 715                                     re1->desc->vol->name_len)) {
 716                                 no_remove_needed = 1;
 717                                 break;
 718                         }
 719                 }
 720
 721                 if (no_remove_needed)
 722                         continue;
 723
 724                 /*
 725                  * It seems we need to remove volume with name @re->new_name,
 726                  * if it exists.
 727                  */
 728                 desc = ubi_open_volume_nm(ubi->ubi_num, re->new_name, UBI_EXCLUSIVE);
 729                 if (IS_ERR(desc)) {
 730                         err = PTR_ERR(desc);
 731                         if (err == -ENODEV)
 732                                 /* Re-naming into a non-existing volume name */
 733                                 continue;
 734
 735                         /* The volume exists but busy, or an error occurred */
 736                         dbg_err("cannot open volume \"%s\", error %d",
 737                                 re->new_name, err);
 738                         goto out_free;
 739                 }
 740
 741                 re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
 742                 if (!re) {
 743                         err = -ENOMEM;
 744                         ubi_close_volume(desc);
 745                         goto out_free;
 746                 }
 747
 748                 re->remove = 1;
 749                 re->desc = desc;
 750                 list_add(&re->list, &rename_list);
 751                 dbg_msg("will remove volume %d, name \"%s\"",
 752                         re->desc->vol->vol_id, re->desc->vol->name);
 753         }
 754
 755         mutex_lock(&ubi->volumes_mutex);
 756         err = ubi_rename_volumes(ubi, &rename_list);
 757         mutex_unlock(&ubi->volumes_mutex);
 758
 759 out_free:
 760         list_for_each_entry_safe(re, re1, &rename_list, list) {
 761                 ubi_close_volume(re->desc);
 762                 list_del(&re->list);
 763                 kfree(re);
 764         }
 765         return err;
 766 }
 767
 768 static int ubi_cdev_ioctl(struct inode *inode, struct file *file,
 769                           unsigned int cmd, unsigned long arg)
 770 {
 771         int err = 0;
 772         struct ubi_device *ubi;
 773         struct ubi_volume_desc *desc;
 774         void __user *argp = (void __user *)arg;
 775
 776         if (!capable(CAP_SYS_RESOURCE))
 777                 return -EPERM;
 778
 779         ubi = ubi_get_by_major(imajor(inode));
 780         if (!ubi)
 781                 return -ENODEV;
 782
 783         switch (cmd) {
 784         /* Create volume command */
 785         case UBI_IOCMKVOL:
 786         {
 787                 struct ubi_mkvol_req req;
 788
 789                 dbg_gen("create volume");
 790                 err = copy_from_user(&req, argp, sizeof(struct ubi_mkvol_req));
 791                 if (err) {
 792                         err = -EFAULT;
 793                         break;
 794                 }
 795
 796                 req.name[req.name_len] = '\0';
 797                 err = verify_mkvol_req(ubi, &req);
 798                 if (err)
 799                         break;
 800
 801                 mutex_lock(&ubi->volumes_mutex);
 802                 err = ubi_create_volume(ubi, &req);
 803                 mutex_unlock(&ubi->volumes_mutex);
 804                 if (err)
 805                         break;
 806
 807                 err = put_user(req.vol_id, (__user int32_t *)argp);
 808                 if (err)
 809                         err = -EFAULT;
 810
 811                 break;
 812         }
 813
 814         /* Remove volume command */
 815         case UBI_IOCRMVOL:
 816         {
 817                 int vol_id;
 818
 819                 dbg_gen("remove volume");
 820                 err = get_user(vol_id, (__user int32_t *)argp);
 821                 if (err) {
 822                         err = -EFAULT;
 823                         break;
 824                 }
 825
 826                 desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
 827                 if (IS_ERR(desc)) {
 828                         err = PTR_ERR(desc);
 829                         break;
 830                 }
 831
 832                 mutex_lock(&ubi->volumes_mutex);
 833                 err = ubi_remove_volume(desc, 0);
 834                 mutex_unlock(&ubi->volumes_mutex);
 835
 836                 /*
 837                  * The volume is deleted (unless an error occurred), and the
 838                  * 'struct ubi_volume' object will be freed when
 839                  * 'ubi_close_volume()' will call 'put_device()'.
 840                  */
 841                 ubi_close_volume(desc);
 842                 break;
 843         }
 844
 845         /* Re-size volume command */
 846         case UBI_IOCRSVOL:
 847         {
 848                 int pebs;
 849                 uint64_t tmp;
 850                 struct ubi_rsvol_req req;
 851
 852                 dbg_gen("re-size volume");
 853                 err = copy_from_user(&req, argp, sizeof(struct ubi_rsvol_req));
 854                 if (err) {
 855                         err = -EFAULT;
 856                         break;
 857                 }
 858
 859                 err = verify_rsvol_req(ubi, &req);
 860                 if (err)
 861                         break;
 862
 863                 desc = ubi_open_volume(ubi->ubi_num, req.vol_id, UBI_EXCLUSIVE);
 864                 if (IS_ERR(desc)) {
 865                         err = PTR_ERR(desc);
 866                         break;
 867                 }
 868
 869                 tmp = req.bytes;
 870                 pebs = !!do_div(tmp, desc->vol->usable_leb_size);
 871                 pebs += tmp;
 872
 873                 mutex_lock(&ubi->volumes_mutex);
 874                 err = ubi_resize_volume(desc, pebs);
 875                 mutex_unlock(&ubi->volumes_mutex);
 876                 ubi_close_volume(desc);
 877                 break;
 878         }
 879
 880         /* Re-name volumes command */
 881         case UBI_IOCRNVOL:
 882         {
 883                 struct ubi_rnvol_req *req;
 884
 885                 dbg_msg("re-name volumes");
 886                 req = kmalloc(sizeof(struct ubi_rnvol_req), GFP_KERNEL);
 887                 if (!req) {
 888                         err = -ENOMEM;
 889                         break;
 890                 };
 891
 892                 err = copy_from_user(req, argp, sizeof(struct ubi_rnvol_req));
 893                 if (err) {
 894                         err = -EFAULT;
 895                         kfree(req);
 896                         break;
 897                 }
 898
 899                 mutex_lock(&ubi->mult_mutex);
 900                 err = rename_volumes(ubi, req);
 901                 mutex_unlock(&ubi->mult_mutex);
 902                 kfree(req);
 903                 break;
 904         }
 905
 906         default:
 907                 err = -ENOTTY;
 908                 break;
 909         }
 910
 911         ubi_put_device(ubi);
 912         return err;
 913 }
 914
 915 static int ctrl_cdev_ioctl(struct inode *inode, struct file *file,
 916                            unsigned int cmd, unsigned long arg)
 917 {
 918         int err = 0;
 919         void __user *argp = (void __user *)arg;
 920
 921         if (!capable(CAP_SYS_RESOURCE))
 922                 return -EPERM;
 923
 924         switch (cmd) {
 925         /* Attach an MTD device command */
 926         case UBI_IOCATT:
 927         {
 928                 struct ubi_attach_req req;
 929                 struct mtd_info *mtd;
 930
 931                 dbg_gen("attach MTD device");
 932                 err = copy_from_user(&req, argp, sizeof(struct ubi_attach_req));
 933                 if (err) {
 934                         err = -EFAULT;
 935                         break;
 936                 }
 937
 938                 if (req.mtd_num < 0 ||
 939                     (req.ubi_num < 0 && req.ubi_num != UBI_DEV_NUM_AUTO)) {
 940                         err = -EINVAL;
 941                         break;
 942                 }
 943
 944                 mtd = get_mtd_device(NULL, req.mtd_num);
 945                 if (IS_ERR(mtd)) {
 946                         err = PTR_ERR(mtd);
 947                         break;
 948                 }
 949
 950                 /*
 951                  * Note, further request verification is done by
 952                  * 'ubi_attach_mtd_dev()'.
 953                  */
 954                 mutex_lock(&ubi_devices_mutex);
 955                 err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset);
 956                 mutex_unlock(&ubi_devices_mutex);
 957                 if (err < 0)
 958                         put_mtd_device(mtd);
 959                 else
 960                         /* @err contains UBI device number */
 961                         err = put_user(err, (__user int32_t *)argp);
 962
 963                 break;
 964         }
 965
 966         /* Detach an MTD device command */
 967         case UBI_IOCDET:
 968         {
 969                 int ubi_num;
 970
 971                 dbg_gen("dettach MTD device");
 972                 err = get_user(ubi_num, (__user int32_t *)argp);
 973                 if (err) {
 974                         err = -EFAULT;
 975                         break;
 976                 }
 977
 978                 mutex_lock(&ubi_devices_mutex);
 979                 err = ubi_detach_mtd_dev(ubi_num, 0);
 980                 mutex_unlock(&ubi_devices_mutex);
 981                 break;
 982         }
 983
 984         default:
 985                 err = -ENOTTY;
 986                 break;
 987         }
 988
 989         return err;
 990 }
 991
 992 /* UBI control character device operations */
 993 struct file_operations ubi_ctrl_cdev_operations = {
 994         .ioctl = ctrl_cdev_ioctl,
 995         .owner = THIS_MODULE,
 996 };
 997
 998 /* UBI character device operations */
 999 struct file_operations ubi_cdev_operations = {
1000         .owner = THIS_MODULE,
1001         .ioctl = ubi_cdev_ioctl,
1002         .llseek = no_llseek,
1003 };
1004
1005 /* UBI volume character device operations */
1006 struct file_operations ubi_vol_cdev_operations = {
1007         .owner   = THIS_MODULE,
1008         .open    = vol_cdev_open,
1009         .release = vol_cdev_release,
1010         .llseek  = vol_cdev_llseek,
1011         .read    = vol_cdev_read,
1012         .write   = vol_cdev_write,
1013         .ioctl   = vol_cdev_ioctl,
1014 };