drivers/mtd/ubi/cdev.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (c) International Business Machines Corp., 2006
   4  *
   5  * Author: Artem Bityutskiy (Битюцкий Артём)
   6  */
   7
   8 /*
   9  * This file includes implementation of UBI character device operations.
  10  *
  11  * There are two kinds of character devices in UBI: UBI character devices and
  12  * UBI volume character devices. UBI character devices allow users to
  13  * manipulate whole volumes: create, remove, and re-size them. Volume character
  14  * devices provide volume I/O capabilities.
  15  *
  16  * Major and minor numbers are assigned dynamically to both UBI and volume
  17  * character devices.
  18  *
  19  * Well, there is the third kind of character devices - the UBI control
  20  * character device, which allows to manipulate by UBI devices - create and
  21  * delete them. In other words, it is used for attaching and detaching MTD
  22  * devices.
  23  */
  24
  25 #include <linux/module.h>
  26 #include <linux/stat.h>
  27 #include <linux/slab.h>
  28 #include <linux/ioctl.h>
  29 #include <linux/capability.h>
  30 #include <linux/uaccess.h>
  31 #include <linux/compat.h>
  32 #include <linux/math64.h>
  33 #include <mtd/ubi-user.h>
  34 #include "ubi.h"
  35
  36 /**
  37  * get_exclusive - get exclusive access to an UBI volume.
  38  * @desc: volume descriptor
  39  *
  40  * This function changes UBI volume open mode to "exclusive". Returns previous
  41  * mode value (positive integer) in case of success and a negative error code
  42  * in case of failure.
  43  */
  44 static int get_exclusive(struct ubi_volume_desc *desc)
  45 {
  46         int users, err;
  47         struct ubi_volume *vol = desc->vol;
  48
  49         spin_lock(&vol->ubi->volumes_lock);
  50         users = vol->readers + vol->writers + vol->exclusive + vol->metaonly;
  51         ubi_assert(users > 0);
  52         if (users > 1) {
  53                 ubi_err(vol->ubi, "%d users for volume %d", users, vol->vol_id);
  54                 err = -EBUSY;
  55         } else {
  56                 vol->readers = vol->writers = vol->metaonly = 0;
  57                 vol->exclusive = 1;
  58                 err = desc->mode;
  59                 desc->mode = UBI_EXCLUSIVE;
  60         }
  61         spin_unlock(&vol->ubi->volumes_lock);
  62
  63         return err;
  64 }
  65
  66 /**
  67  * revoke_exclusive - revoke exclusive mode.
  68  * @desc: volume descriptor
  69  * @mode: new mode to switch to
  70  */
  71 static void revoke_exclusive(struct ubi_volume_desc *desc, int mode)
  72 {
  73         struct ubi_volume *vol = desc->vol;
  74
  75         spin_lock(&vol->ubi->volumes_lock);
  76         ubi_assert(vol->readers == 0 && vol->writers == 0 && vol->metaonly == 0);
  77         ubi_assert(vol->exclusive == 1 && desc->mode == UBI_EXCLUSIVE);
  78         vol->exclusive = 0;
  79         if (mode == UBI_READONLY)
  80                 vol->readers = 1;
  81         else if (mode == UBI_READWRITE)
  82                 vol->writers = 1;
  83         else if (mode == UBI_METAONLY)
  84                 vol->metaonly = 1;
  85         else
  86                 vol->exclusive = 1;
  87         spin_unlock(&vol->ubi->volumes_lock);
  88
  89         desc->mode = mode;
  90 }
  91
  92 static int vol_cdev_open(struct inode *inode, struct file *file)
  93 {
  94         struct ubi_volume_desc *desc;
  95         int vol_id = iminor(inode) - 1, mode, ubi_num;
  96
  97         ubi_num = ubi_major2num(imajor(inode));
  98         if (ubi_num < 0)
  99                 return ubi_num;
 100
 101         if (file->f_mode & FMODE_WRITE)
 102                 mode = UBI_READWRITE;
 103         else
 104                 mode = UBI_READONLY;
 105
 106         dbg_gen("open device %d, volume %d, mode %d",
 107                 ubi_num, vol_id, mode);
 108
 109         desc = ubi_open_volume(ubi_num, vol_id, mode);
 110         if (IS_ERR(desc))
 111                 return PTR_ERR(desc);
 112
 113         file->private_data = desc;
 114         return 0;
 115 }
 116
 117 static int vol_cdev_release(struct inode *inode, struct file *file)
 118 {
 119         struct ubi_volume_desc *desc = file->private_data;
 120         struct ubi_volume *vol = desc->vol;
 121
 122         dbg_gen("release device %d, volume %d, mode %d",
 123                 vol->ubi->ubi_num, vol->vol_id, desc->mode);
 124
 125         if (vol->updating) {
 126                 ubi_warn(vol->ubi, "update of volume %d not finished, volume is damaged",
 127                          vol->vol_id);
 128                 ubi_assert(!vol->changing_leb);
 129                 vol->updating = 0;
 130                 vfree(vol->upd_buf);
 131         } else if (vol->changing_leb) {
 132                 dbg_gen("only %lld of %lld bytes received for atomic LEB change for volume %d:%d, cancel",
 133                         vol->upd_received, vol->upd_bytes, vol->ubi->ubi_num,
 134                         vol->vol_id);
 135                 vol->changing_leb = 0;
 136                 vfree(vol->upd_buf);
 137         }
 138
 139         ubi_close_volume(desc);
 140         return 0;
 141 }
 142
 143 static loff_t vol_cdev_llseek(struct file *file, loff_t offset, int origin)
 144 {
 145         struct ubi_volume_desc *desc = file->private_data;
 146         struct ubi_volume *vol = desc->vol;
 147
 148         if (vol->updating) {
 149                 /* Update is in progress, seeking is prohibited */
 150                 ubi_err(vol->ubi, "updating");
 151                 return -EBUSY;
 152         }
 153
 154         return fixed_size_llseek(file, offset, origin, vol->used_bytes);
 155 }
 156
 157 static int vol_cdev_fsync(struct file *file, loff_t start, loff_t end,
 158                           int datasync)
 159 {
 160         struct ubi_volume_desc *desc = file->private_data;
 161         struct ubi_device *ubi = desc->vol->ubi;
 162         struct inode *inode = file_inode(file);
 163         int err;
 164         inode_lock(inode);
 165         err = ubi_sync(ubi->ubi_num);
 166         inode_unlock(inode);
 167         return err;
 168 }
 169
 170
 171 static ssize_t vol_cdev_read(struct file *file, __user char *buf, size_t count,
 172                              loff_t *offp)
 173 {
 174         struct ubi_volume_desc *desc = file->private_data;
 175         struct ubi_volume *vol = desc->vol;
 176         struct ubi_device *ubi = vol->ubi;
 177         int err, lnum, off, len,  tbuf_size;
 178         size_t count_save = count;
 179         void *tbuf;
 180
 181         dbg_gen("read %zd bytes from offset %lld of volume %d",
 182                 count, *offp, vol->vol_id);
 183
 184         if (vol->updating) {
 185                 ubi_err(vol->ubi, "updating");
 186                 return -EBUSY;
 187         }
 188         if (vol->upd_marker) {
 189                 ubi_err(vol->ubi, "damaged volume, update marker is set");
 190                 return -EBADF;
 191         }
 192         if (*offp == vol->used_bytes || count == 0)
 193                 return 0;
 194
 195         if (vol->corrupted)
 196                 dbg_gen("read from corrupted volume %d", vol->vol_id);
 197
 198         if (*offp + count > vol->used_bytes)
 199                 count_save = count = vol->used_bytes - *offp;
 200
 201         tbuf_size = vol->usable_leb_size;
 202         if (count < tbuf_size)
 203                 tbuf_size = ALIGN(count, ubi->min_io_size);
 204         tbuf = vmalloc(tbuf_size);
 205         if (!tbuf)
 206                 return -ENOMEM;
 207
 208         len = count > tbuf_size ? tbuf_size : count;
 209         lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
 210
 211         do {
 212                 cond_resched();
 213
 214                 if (off + len >= vol->usable_leb_size)
 215                         len = vol->usable_leb_size - off;
 216
 217                 err = ubi_eba_read_leb(ubi, vol, lnum, tbuf, off, len, 0);
 218                 if (err)
 219                         break;
 220
 221                 off += len;
 222                 if (off == vol->usable_leb_size) {
 223                         lnum += 1;
 224                         off -= vol->usable_leb_size;
 225                 }
 226
 227                 count -= len;
 228                 *offp += len;
 229
 230                 err = copy_to_user(buf, tbuf, len);
 231                 if (err) {
 232                         err = -EFAULT;
 233                         break;
 234                 }
 235
 236                 buf += len;
 237                 len = count > tbuf_size ? tbuf_size : count;
 238         } while (count);
 239
 240         vfree(tbuf);
 241         return err ? err : count_save - count;
 242 }
 243
 244 /*
 245  * This function allows to directly write to dynamic UBI volumes, without
 246  * issuing the volume update operation.
 247  */
 248 static ssize_t vol_cdev_direct_write(struct file *file, const char __user *buf,
 249                                      size_t count, loff_t *offp)
 250 {
 251         struct ubi_volume_desc *desc = file->private_data;
 252         struct ubi_volume *vol = desc->vol;
 253         struct ubi_device *ubi = vol->ubi;
 254         int lnum, off, len, tbuf_size, err = 0;
 255         size_t count_save = count;
 256         char *tbuf;
 257
 258         if (!vol->direct_writes)
 259                 return -EPERM;
 260
 261         dbg_gen("requested: write %zd bytes to offset %lld of volume %u",
 262                 count, *offp, vol->vol_id);
 263
 264         if (vol->vol_type == UBI_STATIC_VOLUME)
 265                 return -EROFS;
 266
 267         lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
 268         if (off & (ubi->min_io_size - 1)) {
 269                 ubi_err(ubi, "unaligned position");
 270                 return -EINVAL;
 271         }
 272
 273         if (*offp + count > vol->used_bytes)
 274                 count_save = count = vol->used_bytes - *offp;
 275
 276         /* We can write only in fractions of the minimum I/O unit */
 277         if (count & (ubi->min_io_size - 1)) {
 278                 ubi_err(ubi, "unaligned write length");
 279                 return -EINVAL;
 280         }
 281
 282         tbuf_size = vol->usable_leb_size;
 283         if (count < tbuf_size)
 284                 tbuf_size = ALIGN(count, ubi->min_io_size);
 285         tbuf = vmalloc(tbuf_size);
 286         if (!tbuf)
 287                 return -ENOMEM;
 288
 289         len = count > tbuf_size ? tbuf_size : count;
 290
 291         while (count) {
 292                 cond_resched();
 293
 294                 if (off + len >= vol->usable_leb_size)
 295                         len = vol->usable_leb_size - off;
 296
 297                 err = copy_from_user(tbuf, buf, len);
 298                 if (err) {
 299                         err = -EFAULT;
 300                         break;
 301                 }
 302
 303                 err = ubi_eba_write_leb(ubi, vol, lnum, tbuf, off, len);
 304                 if (err)
 305                         break;
 306
 307                 off += len;
 308                 if (off == vol->usable_leb_size) {
 309                         lnum += 1;
 310                         off -= vol->usable_leb_size;
 311                 }
 312
 313                 count -= len;
 314                 *offp += len;
 315                 buf += len;
 316                 len = count > tbuf_size ? tbuf_size : count;
 317         }
 318
 319         vfree(tbuf);
 320         return err ? err : count_save - count;
 321 }
 322
 323 static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
 324                               size_t count, loff_t *offp)
 325 {
 326         int err = 0;
 327         struct ubi_volume_desc *desc = file->private_data;
 328         struct ubi_volume *vol = desc->vol;
 329         struct ubi_device *ubi = vol->ubi;
 330
 331         if (!vol->updating && !vol->changing_leb)
 332                 return vol_cdev_direct_write(file, buf, count, offp);
 333
 334         if (vol->updating)
 335                 err = ubi_more_update_data(ubi, vol, buf, count);
 336         else
 337                 err = ubi_more_leb_change_data(ubi, vol, buf, count);
 338
 339         if (err < 0) {
 340                 ubi_err(ubi, "cannot accept more %zd bytes of data, error %d",
 341                         count, err);
 342                 return err;
 343         }
 344
 345         if (err) {
 346                 /*
 347                  * The operation is finished, @err contains number of actually
 348                  * written bytes.
 349                  */
 350                 count = err;
 351
 352                 if (vol->changing_leb) {
 353                         revoke_exclusive(desc, UBI_READWRITE);
 354                         return count;
 355                 }
 356
 357                 /*
 358                  * We voluntarily do not take into account the skip_check flag
 359                  * as we want to make sure what we wrote was correctly written.
 360                  */
 361                 err = ubi_check_volume(ubi, vol->vol_id);
 362                 if (err < 0)
 363                         return err;
 364
 365                 if (err) {
 366                         ubi_warn(ubi, "volume %d on UBI device %d is corrupted",
 367                                  vol->vol_id, ubi->ubi_num);
 368                         vol->corrupted = 1;
 369                 }
 370                 vol->checked = 1;
 371                 ubi_volume_notify(ubi, vol, UBI_VOLUME_UPDATED);
 372                 revoke_exclusive(desc, UBI_READWRITE);
 373         }
 374
 375         return count;
 376 }
 377
 378 static long vol_cdev_ioctl(struct file *file, unsigned int cmd,
 379                            unsigned long arg)
 380 {
 381         int err = 0;
 382         struct ubi_volume_desc *desc = file->private_data;
 383         struct ubi_volume *vol = desc->vol;
 384         struct ubi_device *ubi = vol->ubi;
 385         void __user *argp = (void __user *)arg;
 386
 387         switch (cmd) {
 388         /* Volume update command */
 389         case UBI_IOCVOLUP:
 390         {
 391                 int64_t bytes, rsvd_bytes;
 392
 393                 if (!capable(CAP_SYS_RESOURCE)) {
 394                         err = -EPERM;
 395                         break;
 396                 }
 397
 398                 err = copy_from_user(&bytes, argp, sizeof(int64_t));
 399                 if (err) {
 400                         err = -EFAULT;
 401                         break;
 402                 }
 403
 404                 if (desc->mode == UBI_READONLY) {
 405                         err = -EROFS;
 406                         break;
 407                 }
 408
 409                 rsvd_bytes = (long long)vol->reserved_pebs *
 410                                         vol->usable_leb_size;
 411                 if (bytes < 0 || bytes > rsvd_bytes) {
 412                         err = -EINVAL;
 413                         break;
 414                 }
 415
 416                 err = get_exclusive(desc);
 417                 if (err < 0)
 418                         break;
 419
 420                 err = ubi_start_update(ubi, vol, bytes);
 421                 if (bytes == 0) {
 422                         ubi_volume_notify(ubi, vol, UBI_VOLUME_UPDATED);
 423                         revoke_exclusive(desc, UBI_READWRITE);
 424                 }
 425                 break;
 426         }
 427
 428         /* Atomic logical eraseblock change command */
 429         case UBI_IOCEBCH:
 430         {
 431                 struct ubi_leb_change_req req;
 432
 433                 err = copy_from_user(&req, argp,
 434                                      sizeof(struct ubi_leb_change_req));
 435                 if (err) {
 436                         err = -EFAULT;
 437                         break;
 438                 }
 439
 440                 if (desc->mode == UBI_READONLY ||
 441                     vol->vol_type == UBI_STATIC_VOLUME) {
 442                         err = -EROFS;
 443                         break;
 444                 }
 445
 446                 /* Validate the request */
 447                 err = -EINVAL;
 448                 if (!ubi_leb_valid(vol, req.lnum) ||
 449                     req.bytes < 0 || req.bytes > vol->usable_leb_size)
 450                         break;
 451
 452                 err = get_exclusive(desc);
 453                 if (err < 0)
 454                         break;
 455
 456                 err = ubi_start_leb_change(ubi, vol, &req);
 457                 if (req.bytes == 0)
 458                         revoke_exclusive(desc, UBI_READWRITE);
 459                 break;
 460         }
 461
 462         /* Logical eraseblock erasure command */
 463         case UBI_IOCEBER:
 464         {
 465                 int32_t lnum;
 466
 467                 err = get_user(lnum, (__user int32_t *)argp);
 468                 if (err) {
 469                         err = -EFAULT;
 470                         break;
 471                 }
 472
 473                 if (desc->mode == UBI_READONLY ||
 474                     vol->vol_type == UBI_STATIC_VOLUME) {
 475                         err = -EROFS;
 476                         break;
 477                 }
 478
 479                 if (!ubi_leb_valid(vol, lnum)) {
 480                         err = -EINVAL;
 481                         break;
 482                 }
 483
 484                 dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
 485                 err = ubi_eba_unmap_leb(ubi, vol, lnum);
 486                 if (err)
 487                         break;
 488
 489                 err = ubi_wl_flush(ubi, UBI_ALL, UBI_ALL);
 490                 break;
 491         }
 492
 493         /* Logical eraseblock map command */
 494         case UBI_IOCEBMAP:
 495         {
 496                 struct ubi_map_req req;
 497
 498                 err = copy_from_user(&req, argp, sizeof(struct ubi_map_req));
 499                 if (err) {
 500                         err = -EFAULT;
 501                         break;
 502                 }
 503                 err = ubi_leb_map(desc, req.lnum);
 504                 break;
 505         }
 506
 507         /* Logical eraseblock un-map command */
 508         case UBI_IOCEBUNMAP:
 509         {
 510                 int32_t lnum;
 511
 512                 err = get_user(lnum, (__user int32_t *)argp);
 513                 if (err) {
 514                         err = -EFAULT;
 515                         break;
 516                 }
 517                 err = ubi_leb_unmap(desc, lnum);
 518                 break;
 519         }
 520
 521         /* Check if logical eraseblock is mapped command */
 522         case UBI_IOCEBISMAP:
 523         {
 524                 int32_t lnum;
 525
 526                 err = get_user(lnum, (__user int32_t *)argp);
 527                 if (err) {
 528                         err = -EFAULT;
 529                         break;
 530                 }
 531                 err = ubi_is_mapped(desc, lnum);
 532                 break;
 533         }
 534
 535         /* Set volume property command */
 536         case UBI_IOCSETVOLPROP:
 537         {
 538                 struct ubi_set_vol_prop_req req;
 539
 540                 err = copy_from_user(&req, argp,
 541                                      sizeof(struct ubi_set_vol_prop_req));
 542                 if (err) {
 543                         err = -EFAULT;
 544                         break;
 545                 }
 546                 switch (req.property) {
 547                 case UBI_VOL_PROP_DIRECT_WRITE:
 548                         mutex_lock(&ubi->device_mutex);
 549                         desc->vol->direct_writes = !!req.value;
 550                         mutex_unlock(&ubi->device_mutex);
 551                         break;
 552                 default:
 553                         err = -EINVAL;
 554                         break;
 555                 }
 556                 break;
 557         }
 558
 559         /* Create a R/O block device on top of the UBI volume */
 560         case UBI_IOCVOLCRBLK:
 561         {
 562                 struct ubi_volume_info vi;
 563
 564                 ubi_get_volume_info(desc, &vi);
 565                 err = ubiblock_create(&vi);
 566                 break;
 567         }
 568
 569         /* Remove the R/O block device */
 570         case UBI_IOCVOLRMBLK:
 571         {
 572                 struct ubi_volume_info vi;
 573
 574                 ubi_get_volume_info(desc, &vi);
 575                 err = ubiblock_remove(&vi);
 576                 break;
 577         }
 578
 579         default:
 580                 err = -ENOTTY;
 581                 break;
 582         }
 583         return err;
 584 }
 585
 586 /**
 587  * verify_mkvol_req - verify volume creation request.
 588  * @ubi: UBI device description object
 589  * @req: the request to check
 590  *
 591  * This function zero if the request is correct, and %-EINVAL if not.
 592  */
 593 static int verify_mkvol_req(const struct ubi_device *ubi,
 594                             const struct ubi_mkvol_req *req)
 595 {
 596         int n, err = -EINVAL;
 597
 598         if (req->bytes < 0 || req->alignment < 0 || req->vol_type < 0 ||
 599             req->name_len < 0)
 600                 goto bad;
 601
 602         if ((req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) &&
 603             req->vol_id != UBI_VOL_NUM_AUTO)
 604                 goto bad;
 605
 606         if (req->alignment == 0)
 607                 goto bad;
 608
 609         if (req->bytes == 0)
 610                 goto bad;
 611
 612         if (req->vol_type != UBI_DYNAMIC_VOLUME &&
 613             req->vol_type != UBI_STATIC_VOLUME)
 614                 goto bad;
 615
 616         if (req->flags & ~UBI_VOL_VALID_FLGS)
 617                 goto bad;
 618
 619         if (req->flags & UBI_VOL_SKIP_CRC_CHECK_FLG &&
 620             req->vol_type != UBI_STATIC_VOLUME)
 621                 goto bad;
 622
 623         if (req->alignment > ubi->leb_size)
 624                 goto bad;
 625
 626         n = req->alignment & (ubi->min_io_size - 1);
 627         if (req->alignment != 1 && n)
 628                 goto bad;
 629
 630         if (!req->name[0] || !req->name_len)
 631                 goto bad;
 632
 633         if (req->name_len > UBI_VOL_NAME_MAX) {
 634                 err = -ENAMETOOLONG;
 635                 goto bad;
 636         }
 637
 638         n = strnlen(req->name, req->name_len + 1);
 639         if (n != req->name_len)
 640                 goto bad;
 641
 642         return 0;
 643
 644 bad:
 645         ubi_err(ubi, "bad volume creation request");
 646         ubi_dump_mkvol_req(req);
 647         return err;
 648 }
 649
 650 /**
 651  * verify_rsvol_req - verify volume re-size request.
 652  * @ubi: UBI device description object
 653  * @req: the request to check
 654  *
 655  * This function returns zero if the request is correct, and %-EINVAL if not.
 656  */
 657 static int verify_rsvol_req(const struct ubi_device *ubi,
 658                             const struct ubi_rsvol_req *req)
 659 {
 660         if (req->bytes <= 0)
 661                 return -EINVAL;
 662
 663         if (req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots)
 664                 return -EINVAL;
 665
 666         return 0;
 667 }
 668
 669 /**
 670  * rename_volumes - rename UBI volumes.
 671  * @ubi: UBI device description object
 672  * @req: volumes re-name request
 673  *
 674  * This is a helper function for the volume re-name IOCTL which validates the
 675  * the request, opens the volume and calls corresponding volumes management
 676  * function. Returns zero in case of success and a negative error code in case
 677  * of failure.
 678  */
 679 static int rename_volumes(struct ubi_device *ubi,
 680                           struct ubi_rnvol_req *req)
 681 {
 682         int i, n, err;
 683         struct list_head rename_list;
 684         struct ubi_rename_entry *re, *re1;
 685
 686         if (req->count < 0 || req->count > UBI_MAX_RNVOL)
 687                 return -EINVAL;
 688
 689         if (req->count == 0)
 690                 return 0;
 691
 692         /* Validate volume IDs and names in the request */
 693         for (i = 0; i < req->count; i++) {
 694                 if (req->ents[i].vol_id < 0 ||
 695                     req->ents[i].vol_id >= ubi->vtbl_slots)
 696                         return -EINVAL;
 697                 if (req->ents[i].name_len < 0)
 698                         return -EINVAL;
 699                 if (req->ents[i].name_len > UBI_VOL_NAME_MAX)
 700                         return -ENAMETOOLONG;
 701                 req->ents[i].name[req->ents[i].name_len] = '\0';
 702                 n = strlen(req->ents[i].name);
 703                 if (n != req->ents[i].name_len)
 704                         return -EINVAL;
 705         }
 706
 707         /* Make sure volume IDs and names are unique */
 708         for (i = 0; i < req->count - 1; i++) {
 709                 for (n = i + 1; n < req->count; n++) {
 710                         if (req->ents[i].vol_id == req->ents[n].vol_id) {
 711                                 ubi_err(ubi, "duplicated volume id %d",
 712                                         req->ents[i].vol_id);
 713                                 return -EINVAL;
 714                         }
 715                         if (!strcmp(req->ents[i].name, req->ents[n].name)) {
 716                                 ubi_err(ubi, "duplicated volume name \"%s\"",
 717                                         req->ents[i].name);
 718                                 return -EINVAL;
 719                         }
 720                 }
 721         }
 722
 723         /* Create the re-name list */
 724         INIT_LIST_HEAD(&rename_list);
 725         for (i = 0; i < req->count; i++) {
 726                 int vol_id = req->ents[i].vol_id;
 727                 int name_len = req->ents[i].name_len;
 728                 const char *name = req->ents[i].name;
 729
 730                 re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
 731                 if (!re) {
 732                         err = -ENOMEM;
 733                         goto out_free;
 734                 }
 735
 736                 re->desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_METAONLY);
 737                 if (IS_ERR(re->desc)) {
 738                         err = PTR_ERR(re->desc);
 739                         ubi_err(ubi, "cannot open volume %d, error %d",
 740                                 vol_id, err);
 741                         kfree(re);
 742                         goto out_free;
 743                 }
 744
 745                 /* Skip this re-naming if the name does not really change */
 746                 if (re->desc->vol->name_len == name_len &&
 747                     !memcmp(re->desc->vol->name, name, name_len)) {
 748                         ubi_close_volume(re->desc);
 749                         kfree(re);
 750                         continue;
 751                 }
 752
 753                 re->new_name_len = name_len;
 754                 memcpy(re->new_name, name, name_len);
 755                 list_add_tail(&re->list, &rename_list);
 756                 dbg_gen("will rename volume %d from \"%s\" to \"%s\"",
 757                         vol_id, re->desc->vol->name, name);
 758         }
 759
 760         if (list_empty(&rename_list))
 761                 return 0;
 762
 763         /* Find out the volumes which have to be removed */
 764         list_for_each_entry(re, &rename_list, list) {
 765                 struct ubi_volume_desc *desc;
 766                 int no_remove_needed = 0;
 767
 768                 /*
 769                  * Volume @re->vol_id is going to be re-named to
 770                  * @re->new_name, while its current name is @name. If a volume
 771                  * with name @re->new_name currently exists, it has to be
 772                  * removed, unless it is also re-named in the request (@req).
 773                  */
 774                 list_for_each_entry(re1, &rename_list, list) {
 775                         if (re->new_name_len == re1->desc->vol->name_len &&
 776                             !memcmp(re->new_name, re1->desc->vol->name,
 777                                     re1->desc->vol->name_len)) {
 778                                 no_remove_needed = 1;
 779                                 break;
 780                         }
 781                 }
 782
 783                 if (no_remove_needed)
 784                         continue;
 785
 786                 /*
 787                  * It seems we need to remove volume with name @re->new_name,
 788                  * if it exists.
 789                  */
 790                 desc = ubi_open_volume_nm(ubi->ubi_num, re->new_name,
 791                                           UBI_EXCLUSIVE);
 792                 if (IS_ERR(desc)) {
 793                         err = PTR_ERR(desc);
 794                         if (err == -ENODEV)
 795                                 /* Re-naming into a non-existing volume name */
 796                                 continue;
 797
 798                         /* The volume exists but busy, or an error occurred */
 799                         ubi_err(ubi, "cannot open volume \"%s\", error %d",
 800                                 re->new_name, err);
 801                         goto out_free;
 802                 }
 803
 804                 re1 = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
 805                 if (!re1) {
 806                         err = -ENOMEM;
 807                         ubi_close_volume(desc);
 808                         goto out_free;
 809                 }
 810
 811                 re1->remove = 1;
 812                 re1->desc = desc;
 813                 list_add(&re1->list, &rename_list);
 814                 dbg_gen("will remove volume %d, name \"%s\"",
 815                         re1->desc->vol->vol_id, re1->desc->vol->name);
 816         }
 817
 818         mutex_lock(&ubi->device_mutex);
 819         err = ubi_rename_volumes(ubi, &rename_list);
 820         mutex_unlock(&ubi->device_mutex);
 821
 822 out_free:
 823         list_for_each_entry_safe(re, re1, &rename_list, list) {
 824                 ubi_close_volume(re->desc);
 825                 list_del(&re->list);
 826                 kfree(re);
 827         }
 828         return err;
 829 }
 830
 831 static long ubi_cdev_ioctl(struct file *file, unsigned int cmd,
 832                            unsigned long arg)
 833 {
 834         int err = 0;
 835         struct ubi_device *ubi;
 836         struct ubi_volume_desc *desc;
 837         void __user *argp = (void __user *)arg;
 838
 839         if (!capable(CAP_SYS_RESOURCE))
 840                 return -EPERM;
 841
 842         ubi = ubi_get_by_major(imajor(file->f_mapping->host));
 843         if (!ubi)
 844                 return -ENODEV;
 845
 846         switch (cmd) {
 847         /* Create volume command */
 848         case UBI_IOCMKVOL:
 849         {
 850                 struct ubi_mkvol_req req;
 851
 852                 dbg_gen("create volume");
 853                 err = copy_from_user(&req, argp, sizeof(struct ubi_mkvol_req));
 854                 if (err) {
 855                         err = -EFAULT;
 856                         break;
 857                 }
 858
 859                 err = verify_mkvol_req(ubi, &req);
 860                 if (err)
 861                         break;
 862
 863                 mutex_lock(&ubi->device_mutex);
 864                 err = ubi_create_volume(ubi, &req);
 865                 mutex_unlock(&ubi->device_mutex);
 866                 if (err)
 867                         break;
 868
 869                 err = put_user(req.vol_id, (__user int32_t *)argp);
 870                 if (err)
 871                         err = -EFAULT;
 872
 873                 break;
 874         }
 875
 876         /* Remove volume command */
 877         case UBI_IOCRMVOL:
 878         {
 879                 int vol_id;
 880
 881                 dbg_gen("remove volume");
 882                 err = get_user(vol_id, (__user int32_t *)argp);
 883                 if (err) {
 884                         err = -EFAULT;
 885                         break;
 886                 }
 887
 888                 desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
 889                 if (IS_ERR(desc)) {
 890                         err = PTR_ERR(desc);
 891                         break;
 892                 }
 893
 894                 mutex_lock(&ubi->device_mutex);
 895                 err = ubi_remove_volume(desc, 0);
 896                 mutex_unlock(&ubi->device_mutex);
 897
 898                 /*
 899                  * The volume is deleted (unless an error occurred), and the
 900                  * 'struct ubi_volume' object will be freed when
 901                  * 'ubi_close_volume()' will call 'put_device()'.
 902                  */
 903                 ubi_close_volume(desc);
 904                 break;
 905         }
 906
 907         /* Re-size volume command */
 908         case UBI_IOCRSVOL:
 909         {
 910                 int pebs;
 911                 struct ubi_rsvol_req req;
 912
 913                 dbg_gen("re-size volume");
 914                 err = copy_from_user(&req, argp, sizeof(struct ubi_rsvol_req));
 915                 if (err) {
 916                         err = -EFAULT;
 917                         break;
 918                 }
 919
 920                 err = verify_rsvol_req(ubi, &req);
 921                 if (err)
 922                         break;
 923
 924                 desc = ubi_open_volume(ubi->ubi_num, req.vol_id, UBI_EXCLUSIVE);
 925                 if (IS_ERR(desc)) {
 926                         err = PTR_ERR(desc);
 927                         break;
 928                 }
 929
 930                 pebs = div_u64(req.bytes + desc->vol->usable_leb_size - 1,
 931                                desc->vol->usable_leb_size);
 932
 933                 mutex_lock(&ubi->device_mutex);
 934                 err = ubi_resize_volume(desc, pebs);
 935                 mutex_unlock(&ubi->device_mutex);
 936                 ubi_close_volume(desc);
 937                 break;
 938         }
 939
 940         /* Re-name volumes command */
 941         case UBI_IOCRNVOL:
 942         {
 943                 struct ubi_rnvol_req *req;
 944
 945                 dbg_gen("re-name volumes");
 946                 req = kmalloc(sizeof(struct ubi_rnvol_req), GFP_KERNEL);
 947                 if (!req) {
 948                         err = -ENOMEM;
 949                         break;
 950                 }
 951
 952                 err = copy_from_user(req, argp, sizeof(struct ubi_rnvol_req));
 953                 if (err) {
 954                         err = -EFAULT;
 955                         kfree(req);
 956                         break;
 957                 }
 958
 959                 err = rename_volumes(ubi, req);
 960                 kfree(req);
 961                 break;
 962         }
 963
 964         /* Check a specific PEB for bitflips and scrub it if needed */
 965         case UBI_IOCRPEB:
 966         {
 967                 int pnum;
 968
 969                 err = get_user(pnum, (__user int32_t *)argp);
 970                 if (err) {
 971                         err = -EFAULT;
 972                         break;
 973                 }
 974
 975                 err = ubi_bitflip_check(ubi, pnum, 0);
 976                 break;
 977         }
 978
 979         /* Force scrubbing for a specific PEB */
 980         case UBI_IOCSPEB:
 981         {
 982                 int pnum;
 983
 984                 err = get_user(pnum, (__user int32_t *)argp);
 985                 if (err) {
 986                         err = -EFAULT;
 987                         break;
 988                 }
 989
 990                 err = ubi_bitflip_check(ubi, pnum, 1);
 991                 break;
 992         }
 993
 994         default:
 995                 err = -ENOTTY;
 996                 break;
 997         }
 998
 999         ubi_put_device(ubi);
1000         return err;
1001 }
1002
1003 static long ctrl_cdev_ioctl(struct file *file, unsigned int cmd,
1004                             unsigned long arg)
1005 {
1006         int err = 0;
1007         void __user *argp = (void __user *)arg;
1008
1009         if (!capable(CAP_SYS_RESOURCE))
1010                 return -EPERM;
1011
1012         switch (cmd) {
1013         /* Attach an MTD device command */
1014         case UBI_IOCATT:
1015         {
1016                 struct ubi_attach_req req;
1017                 struct mtd_info *mtd;
1018
1019                 dbg_gen("attach MTD device");
1020                 err = copy_from_user(&req, argp, sizeof(struct ubi_attach_req));
1021                 if (err) {
1022                         err = -EFAULT;
1023                         break;
1024                 }
1025
1026                 if (req.mtd_num < 0 ||
1027                     (req.ubi_num < 0 && req.ubi_num != UBI_DEV_NUM_AUTO)) {
1028                         err = -EINVAL;
1029                         break;
1030                 }
1031
1032                 mtd = get_mtd_device(NULL, req.mtd_num);
1033                 if (IS_ERR(mtd)) {
1034                         err = PTR_ERR(mtd);
1035                         break;
1036                 }
1037
1038                 /*
1039                  * Note, further request verification is done by
1040                  * 'ubi_attach_mtd_dev()'.
1041                  */
1042                 mutex_lock(&ubi_devices_mutex);
1043                 err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset,
1044                                          req.max_beb_per1024);
1045                 mutex_unlock(&ubi_devices_mutex);
1046                 if (err < 0)
1047                         put_mtd_device(mtd);
1048                 else
1049                         /* @err contains UBI device number */
1050                         err = put_user(err, (__user int32_t *)argp);
1051
1052                 break;
1053         }
1054
1055         /* Detach an MTD device command */
1056         case UBI_IOCDET:
1057         {
1058                 int ubi_num;
1059
1060                 dbg_gen("detach MTD device");
1061                 err = get_user(ubi_num, (__user int32_t *)argp);
1062                 if (err) {
1063                         err = -EFAULT;
1064                         break;
1065                 }
1066
1067                 mutex_lock(&ubi_devices_mutex);
1068                 err = ubi_detach_mtd_dev(ubi_num, 0);
1069                 mutex_unlock(&ubi_devices_mutex);
1070                 break;
1071         }
1072
1073         default:
1074                 err = -ENOTTY;
1075                 break;
1076         }
1077
1078         return err;
1079 }
1080
1081 /* UBI volume character device operations */
1082 const struct file_operations ubi_vol_cdev_operations = {
1083         .owner          = THIS_MODULE,
1084         .open           = vol_cdev_open,
1085         .release        = vol_cdev_release,
1086         .llseek         = vol_cdev_llseek,
1087         .read           = vol_cdev_read,
1088         .write          = vol_cdev_write,
1089         .fsync          = vol_cdev_fsync,
1090         .unlocked_ioctl = vol_cdev_ioctl,
1091         .compat_ioctl   = compat_ptr_ioctl,
1092 };
1093
1094 /* UBI character device operations */
1095 const struct file_operations ubi_cdev_operations = {
1096         .owner          = THIS_MODULE,
1097         .llseek         = no_llseek,
1098         .unlocked_ioctl = ubi_cdev_ioctl,
1099         .compat_ioctl   = compat_ptr_ioctl,
1100 };
1101
1102 /* UBI control character device operations */
1103 const struct file_operations ubi_ctrl_cdev_operations = {
1104         .owner          = THIS_MODULE,
1105         .unlocked_ioctl = ctrl_cdev_ioctl,
1106         .compat_ioctl   = compat_ptr_ioctl,
1107         .llseek         = no_llseek,
1108 };