drivers/mtd/ubi/kapi.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 /* This file mostly implements UBI kernel API functions */
  22
  23 #include <linux/module.h>
  24 #include <linux/err.h>
  25 #include <asm/div64.h>
  26 #include "ubi.h"
  27
  28 /**
  29  * ubi_do_get_device_info - get information about UBI device.
  30  * @ubi: UBI device description object
  31  * @di: the information is stored here
  32  *
  33  * This function is the same as 'ubi_get_device_info()', but it assumes the UBI
  34  * device is locked and cannot disappear.
  35  */
  36 void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di)
  37 {
  38         di->ubi_num = ubi->ubi_num;
  39         di->leb_size = ubi->leb_size;
  40         di->min_io_size = ubi->min_io_size;
  41         di->ro_mode = ubi->ro_mode;
  42         di->cdev = ubi->cdev.dev;
  43 }
  44 EXPORT_SYMBOL_GPL(ubi_do_get_device_info);
  45
  46 /**
  47  * ubi_get_device_info - get information about UBI device.
  48  * @ubi_num: UBI device number
  49  * @di: the information is stored here
  50  *
  51  * This function returns %0 in case of success, %-EINVAL if the UBI device
  52  * number is invalid, and %-ENODEV if there is no such UBI device.
  53  */
  54 int ubi_get_device_info(int ubi_num, struct ubi_device_info *di)
  55 {
  56         struct ubi_device *ubi;
  57
  58         if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
  59                 return -EINVAL;
  60         ubi = ubi_get_device(ubi_num);
  61         if (!ubi)
  62                 return -ENODEV;
  63         ubi_do_get_device_info(ubi, di);
  64         ubi_put_device(ubi);
  65         return 0;
  66 }
  67 EXPORT_SYMBOL_GPL(ubi_get_device_info);
  68
  69 /**
  70  * ubi_do_get_volume_info - get information about UBI volume.
  71  * @ubi: UBI device description object
  72  * @vol: volume description object
  73  * @vi: the information is stored here
  74  */
  75 void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
  76                             struct ubi_volume_info *vi)
  77 {
  78         vi->vol_id = vol->vol_id;
  79         vi->ubi_num = ubi->ubi_num;
  80         vi->size = vol->reserved_pebs;
  81         vi->used_bytes = vol->used_bytes;
  82         vi->vol_type = vol->vol_type;
  83         vi->corrupted = vol->corrupted;
  84         vi->upd_marker = vol->upd_marker;
  85         vi->alignment = vol->alignment;
  86         vi->usable_leb_size = vol->usable_leb_size;
  87         vi->name_len = vol->name_len;
  88         vi->name = vol->name;
  89         vi->cdev = vol->cdev.dev;
  90 }
  91
  92 /**
  93  * ubi_get_volume_info - get information about UBI volume.
  94  * @desc: volume descriptor
  95  * @vi: the information is stored here
  96  */
  97 void ubi_get_volume_info(struct ubi_volume_desc *desc,
  98                          struct ubi_volume_info *vi)
  99 {
 100         ubi_do_get_volume_info(desc->vol->ubi, desc->vol, vi);
 101 }
 102 EXPORT_SYMBOL_GPL(ubi_get_volume_info);
 103
 104 /**
 105  * ubi_open_volume - open UBI volume.
 106  * @ubi_num: UBI device number
 107  * @vol_id: volume ID
 108  * @mode: open mode
 109  *
 110  * The @mode parameter specifies if the volume should be opened in read-only
 111  * mode, read-write mode, or exclusive mode. The exclusive mode guarantees that
 112  * nobody else will be able to open this volume. UBI allows to have many volume
 113  * readers and one writer at a time.
 114  *
 115  * If a static volume is being opened for the first time since boot, it will be
 116  * checked by this function, which means it will be fully read and the CRC
 117  * checksum of each logical eraseblock will be checked.
 118  *
 119  * This function returns volume descriptor in case of success and a negative
 120  * error code in case of failure.
 121  */
 122 struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode)
 123 {
 124         int err;
 125         struct ubi_volume_desc *desc;
 126         struct ubi_device *ubi;
 127         struct ubi_volume *vol;
 128
 129         dbg_gen("open device %d, volume %d, mode %d", ubi_num, vol_id, mode);
 130
 131         if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
 132                 return ERR_PTR(-EINVAL);
 133
 134         if (mode != UBI_READONLY && mode != UBI_READWRITE &&
 135             mode != UBI_EXCLUSIVE)
 136                 return ERR_PTR(-EINVAL);
 137
 138         /*
 139          * First of all, we have to get the UBI device to prevent its removal.
 140          */
 141         ubi = ubi_get_device(ubi_num);
 142         if (!ubi)
 143                 return ERR_PTR(-ENODEV);
 144
 145         if (vol_id < 0 || vol_id >= ubi->vtbl_slots) {
 146                 err = -EINVAL;
 147                 goto out_put_ubi;
 148         }
 149
 150         desc = kmalloc(sizeof(struct ubi_volume_desc), GFP_KERNEL);
 151         if (!desc) {
 152                 err = -ENOMEM;
 153                 goto out_put_ubi;
 154         }
 155
 156         err = -ENODEV;
 157         if (!try_module_get(THIS_MODULE))
 158                 goto out_free;
 159
 160         spin_lock(&ubi->volumes_lock);
 161         vol = ubi->volumes[vol_id];
 162         if (!vol)
 163                 goto out_unlock;
 164
 165         err = -EBUSY;
 166         switch (mode) {
 167         case UBI_READONLY:
 168                 if (vol->exclusive)
 169                         goto out_unlock;
 170                 vol->readers += 1;
 171                 break;
 172
 173         case UBI_READWRITE:
 174                 if (vol->exclusive || vol->writers > 0)
 175                         goto out_unlock;
 176                 vol->writers += 1;
 177                 break;
 178
 179         case UBI_EXCLUSIVE:
 180                 if (vol->exclusive || vol->writers || vol->readers)
 181                         goto out_unlock;
 182                 vol->exclusive = 1;
 183                 break;
 184         }
 185         get_device(&vol->dev);
 186         vol->ref_count += 1;
 187         spin_unlock(&ubi->volumes_lock);
 188
 189         desc->vol = vol;
 190         desc->mode = mode;
 191
 192         mutex_lock(&ubi->ckvol_mutex);
 193         if (!vol->checked) {
 194                 /* This is the first open - check the volume */
 195                 err = ubi_check_volume(ubi, vol_id);
 196                 if (err < 0) {
 197                         mutex_unlock(&ubi->ckvol_mutex);
 198                         ubi_close_volume(desc);
 199                         return ERR_PTR(err);
 200                 }
 201                 if (err == 1) {
 202                         ubi_warn("volume %d on UBI device %d is corrupted",
 203                                  vol_id, ubi->ubi_num);
 204                         vol->corrupted = 1;
 205                 }
 206                 vol->checked = 1;
 207         }
 208         mutex_unlock(&ubi->ckvol_mutex);
 209
 210         return desc;
 211
 212 out_unlock:
 213         spin_unlock(&ubi->volumes_lock);
 214         module_put(THIS_MODULE);
 215 out_free:
 216         kfree(desc);
 217 out_put_ubi:
 218         ubi_put_device(ubi);
 219         dbg_err("cannot open device %d, volume %d, error %d",
 220                 ubi_num, vol_id, err);
 221         return ERR_PTR(err);
 222 }
 223 EXPORT_SYMBOL_GPL(ubi_open_volume);
 224
 225 /**
 226  * ubi_open_volume_nm - open UBI volume by name.
 227  * @ubi_num: UBI device number
 228  * @name: volume name
 229  * @mode: open mode
 230  *
 231  * This function is similar to 'ubi_open_volume()', but opens a volume by name.
 232  */
 233 struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
 234                                            int mode)
 235 {
 236         int i, vol_id = -1, len;
 237         struct ubi_device *ubi;
 238         struct ubi_volume_desc *ret;
 239
 240         dbg_gen("open device %d, volume %s, mode %d", ubi_num, name, mode);
 241
 242         if (!name)
 243                 return ERR_PTR(-EINVAL);
 244
 245         len = strnlen(name, UBI_VOL_NAME_MAX + 1);
 246         if (len > UBI_VOL_NAME_MAX)
 247                 return ERR_PTR(-EINVAL);
 248
 249         if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
 250                 return ERR_PTR(-EINVAL);
 251
 252         ubi = ubi_get_device(ubi_num);
 253         if (!ubi)
 254                 return ERR_PTR(-ENODEV);
 255
 256         spin_lock(&ubi->volumes_lock);
 257         /* Walk all volumes of this UBI device */
 258         for (i = 0; i < ubi->vtbl_slots; i++) {
 259                 struct ubi_volume *vol = ubi->volumes[i];
 260
 261                 if (vol && len == vol->name_len && !strcmp(name, vol->name)) {
 262                         vol_id = i;
 263                         break;
 264                 }
 265         }
 266         spin_unlock(&ubi->volumes_lock);
 267
 268         if (vol_id >= 0)
 269                 ret = ubi_open_volume(ubi_num, vol_id, mode);
 270         else
 271                 ret = ERR_PTR(-ENODEV);
 272
 273         /*
 274          * We should put the UBI device even in case of success, because
 275          * 'ubi_open_volume()' took a reference as well.
 276          */
 277         ubi_put_device(ubi);
 278         return ret;
 279 }
 280 EXPORT_SYMBOL_GPL(ubi_open_volume_nm);
 281
 282 /**
 283  * ubi_close_volume - close UBI volume.
 284  * @desc: volume descriptor
 285  */
 286 void ubi_close_volume(struct ubi_volume_desc *desc)
 287 {
 288         struct ubi_volume *vol = desc->vol;
 289         struct ubi_device *ubi = vol->ubi;
 290
 291         dbg_gen("close device %d, volume %d, mode %d",
 292                 ubi->ubi_num, vol->vol_id, desc->mode);
 293
 294         spin_lock(&ubi->volumes_lock);
 295         switch (desc->mode) {
 296         case UBI_READONLY:
 297                 vol->readers -= 1;
 298                 break;
 299         case UBI_READWRITE:
 300                 vol->writers -= 1;
 301                 break;
 302         case UBI_EXCLUSIVE:
 303                 vol->exclusive = 0;
 304         }
 305         vol->ref_count -= 1;
 306         spin_unlock(&ubi->volumes_lock);
 307
 308         kfree(desc);
 309         put_device(&vol->dev);
 310         ubi_put_device(ubi);
 311         module_put(THIS_MODULE);
 312 }
 313 EXPORT_SYMBOL_GPL(ubi_close_volume);
 314
 315 /**
 316  * ubi_leb_read - read data.
 317  * @desc: volume descriptor
 318  * @lnum: logical eraseblock number to read from
 319  * @buf: buffer where to store the read data
 320  * @offset: offset within the logical eraseblock to read from
 321  * @len: how many bytes to read
 322  * @check: whether UBI has to check the read data's CRC or not.
 323  *
 324  * This function reads data from offset @offset of logical eraseblock @lnum and
 325  * stores the data at @buf. When reading from static volumes, @check specifies
 326  * whether the data has to be checked or not. If yes, the whole logical
 327  * eraseblock will be read and its CRC checksum will be checked (i.e., the CRC
 328  * checksum is per-eraseblock). So checking may substantially slow down the
 329  * read speed. The @check argument is ignored for dynamic volumes.
 330  *
 331  * In case of success, this function returns zero. In case of failure, this
 332  * function returns a negative error code.
 333  *
 334  * %-EBADMSG error code is returned:
 335  * o for both static and dynamic volumes if MTD driver has detected a data
 336  *   integrity problem (unrecoverable ECC checksum mismatch in case of NAND);
 337  * o for static volumes in case of data CRC mismatch.
 338  *
 339  * If the volume is damaged because of an interrupted update this function just
 340  * returns immediately with %-EBADF error code.
 341  */
 342 int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
 343                  int len, int check)
 344 {
 345         struct ubi_volume *vol = desc->vol;
 346         struct ubi_device *ubi = vol->ubi;
 347         int err, vol_id = vol->vol_id;
 348
 349         dbg_gen("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset);
 350
 351         if (vol_id < 0 || vol_id >= ubi->vtbl_slots || lnum < 0 ||
 352             lnum >= vol->used_ebs || offset < 0 || len < 0 ||
 353             offset + len > vol->usable_leb_size)
 354                 return -EINVAL;
 355
 356         if (vol->vol_type == UBI_STATIC_VOLUME) {
 357                 if (vol->used_ebs == 0)
 358                         /* Empty static UBI volume */
 359                         return 0;
 360                 if (lnum == vol->used_ebs - 1 &&
 361                     offset + len > vol->last_eb_bytes)
 362                         return -EINVAL;
 363         }
 364
 365         if (vol->upd_marker)
 366                 return -EBADF;
 367         if (len == 0)
 368                 return 0;
 369
 370         err = ubi_eba_read_leb(ubi, vol, lnum, buf, offset, len, check);
 371         if (err && err == -EBADMSG && vol->vol_type == UBI_STATIC_VOLUME) {
 372                 ubi_warn("mark volume %d as corrupted", vol_id);
 373                 vol->corrupted = 1;
 374         }
 375
 376         return err;
 377 }
 378 EXPORT_SYMBOL_GPL(ubi_leb_read);
 379
 380 /**
 381  * ubi_leb_write - write data.
 382  * @desc: volume descriptor
 383  * @lnum: logical eraseblock number to write to
 384  * @buf: data to write
 385  * @offset: offset within the logical eraseblock where to write
 386  * @len: how many bytes to write
 387  * @dtype: expected data type
 388  *
 389  * This function writes @len bytes of data from @buf to offset @offset of
 390  * logical eraseblock @lnum. The @dtype argument describes expected lifetime of
 391  * the data.
 392  *
 393  * This function takes care of physical eraseblock write failures. If write to
 394  * the physical eraseblock write operation fails, the logical eraseblock is
 395  * re-mapped to another physical eraseblock, the data is recovered, and the
 396  * write finishes. UBI has a pool of reserved physical eraseblocks for this.
 397  *
 398  * If all the data were successfully written, zero is returned. If an error
 399  * occurred and UBI has not been able to recover from it, this function returns
 400  * a negative error code. Note, in case of an error, it is possible that
 401  * something was still written to the flash media, but that may be some
 402  * garbage.
 403  *
 404  * If the volume is damaged because of an interrupted update this function just
 405  * returns immediately with %-EBADF code.
 406  */
 407 int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
 408                   int offset, int len, int dtype)
 409 {
 410         struct ubi_volume *vol = desc->vol;
 411         struct ubi_device *ubi = vol->ubi;
 412         int vol_id = vol->vol_id;
 413
 414         dbg_gen("write %d bytes to LEB %d:%d:%d", len, vol_id, lnum, offset);
 415
 416         if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
 417                 return -EINVAL;
 418
 419         if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
 420                 return -EROFS;
 421
 422         if (lnum < 0 || lnum >= vol->reserved_pebs || offset < 0 || len < 0 ||
 423             offset + len > vol->usable_leb_size ||
 424             offset & (ubi->min_io_size - 1) || len & (ubi->min_io_size - 1))
 425                 return -EINVAL;
 426
 427         if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
 428             dtype != UBI_UNKNOWN)
 429                 return -EINVAL;
 430
 431         if (vol->upd_marker)
 432                 return -EBADF;
 433
 434         if (len == 0)
 435                 return 0;
 436
 437         return ubi_eba_write_leb(ubi, vol, lnum, buf, offset, len, dtype);
 438 }
 439 EXPORT_SYMBOL_GPL(ubi_leb_write);
 440
 441 /*
 442  * ubi_leb_change - change logical eraseblock atomically.
 443  * @desc: volume descriptor
 444  * @lnum: logical eraseblock number to change
 445  * @buf: data to write
 446  * @len: how many bytes to write
 447  * @dtype: expected data type
 448  *
 449  * This function changes the contents of a logical eraseblock atomically. @buf
 450  * has to contain new logical eraseblock data, and @len - the length of the
 451  * data, which has to be aligned. The length may be shorter then the logical
 452  * eraseblock size, ant the logical eraseblock may be appended to more times
 453  * later on. This function guarantees that in case of an unclean reboot the old
 454  * contents is preserved. Returns zero in case of success and a negative error
 455  * code in case of failure.
 456  */
 457 int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
 458                    int len, int dtype)
 459 {
 460         struct ubi_volume *vol = desc->vol;
 461         struct ubi_device *ubi = vol->ubi;
 462         int vol_id = vol->vol_id;
 463
 464         dbg_gen("atomically write %d bytes to LEB %d:%d", len, vol_id, lnum);
 465
 466         if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
 467                 return -EINVAL;
 468
 469         if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
 470                 return -EROFS;
 471
 472         if (lnum < 0 || lnum >= vol->reserved_pebs || len < 0 ||
 473             len > vol->usable_leb_size || len & (ubi->min_io_size - 1))
 474                 return -EINVAL;
 475
 476         if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
 477             dtype != UBI_UNKNOWN)
 478                 return -EINVAL;
 479
 480         if (vol->upd_marker)
 481                 return -EBADF;
 482
 483         if (len == 0)
 484                 return 0;
 485
 486         return ubi_eba_atomic_leb_change(ubi, vol, lnum, buf, len, dtype);
 487 }
 488 EXPORT_SYMBOL_GPL(ubi_leb_change);
 489
 490 /**
 491  * ubi_leb_erase - erase logical eraseblock.
 492  * @desc: volume descriptor
 493  * @lnum: logical eraseblock number
 494  *
 495  * This function un-maps logical eraseblock @lnum and synchronously erases the
 496  * correspondent physical eraseblock. Returns zero in case of success and a
 497  * negative error code in case of failure.
 498  *
 499  * If the volume is damaged because of an interrupted update this function just
 500  * returns immediately with %-EBADF code.
 501  */
 502 int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum)
 503 {
 504         struct ubi_volume *vol = desc->vol;
 505         struct ubi_device *ubi = vol->ubi;
 506         int err;
 507
 508         dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
 509
 510         if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
 511                 return -EROFS;
 512
 513         if (lnum < 0 || lnum >= vol->reserved_pebs)
 514                 return -EINVAL;
 515
 516         if (vol->upd_marker)
 517                 return -EBADF;
 518
 519         err = ubi_eba_unmap_leb(ubi, vol, lnum);
 520         if (err)
 521                 return err;
 522
 523         return ubi_wl_flush(ubi);
 524 }
 525 EXPORT_SYMBOL_GPL(ubi_leb_erase);
 526
 527 /**
 528  * ubi_leb_unmap - un-map logical eraseblock.
 529  * @desc: volume descriptor
 530  * @lnum: logical eraseblock number
 531  *
 532  * This function un-maps logical eraseblock @lnum and schedules the
 533  * corresponding physical eraseblock for erasure, so that it will eventually be
 534  * physically erased in background. This operation is much faster then the
 535  * erase operation.
 536  *
 537  * Unlike erase, the un-map operation does not guarantee that the logical
 538  * eraseblock will contain all 0xFF bytes when UBI is initialized again. For
 539  * example, if several logical eraseblocks are un-mapped, and an unclean reboot
 540  * happens after this, the logical eraseblocks will not necessarily be
 541  * un-mapped again when this MTD device is attached. They may actually be
 542  * mapped to the same physical eraseblocks again. So, this function has to be
 543  * used with care.
 544  *
 545  * In other words, when un-mapping a logical eraseblock, UBI does not store
 546  * any information about this on the flash media, it just marks the logical
 547  * eraseblock as "un-mapped" in RAM. If UBI is detached before the physical
 548  * eraseblock is physically erased, it will be mapped again to the same logical
 549  * eraseblock when the MTD device is attached again.
 550  *
 551  * The main and obvious use-case of this function is when the contents of a
 552  * logical eraseblock has to be re-written. Then it is much more efficient to
 553  * first un-map it, then write new data, rather then first erase it, then write
 554  * new data. Note, once new data has been written to the logical eraseblock,
 555  * UBI guarantees that the old contents has gone forever. In other words, if an
 556  * unclean reboot happens after the logical eraseblock has been un-mapped and
 557  * then written to, it will contain the last written data.
 558  *
 559  * This function returns zero in case of success and a negative error code in
 560  * case of failure. If the volume is damaged because of an interrupted update
 561  * this function just returns immediately with %-EBADF code.
 562  */
 563 int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum)
 564 {
 565         struct ubi_volume *vol = desc->vol;
 566         struct ubi_device *ubi = vol->ubi;
 567
 568         dbg_gen("unmap LEB %d:%d", vol->vol_id, lnum);
 569
 570         if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
 571                 return -EROFS;
 572
 573         if (lnum < 0 || lnum >= vol->reserved_pebs)
 574                 return -EINVAL;
 575
 576         if (vol->upd_marker)
 577                 return -EBADF;
 578
 579         return ubi_eba_unmap_leb(ubi, vol, lnum);
 580 }
 581 EXPORT_SYMBOL_GPL(ubi_leb_unmap);
 582
 583 /**
 584  * ubi_leb_map - map logical eraseblock to a physical eraseblock.
 585  * @desc: volume descriptor
 586  * @lnum: logical eraseblock number
 587  * @dtype: expected data type
 588  *
 589  * This function maps an un-mapped logical eraseblock @lnum to a physical
 590  * eraseblock. This means, that after a successful invocation of this
 591  * function the logical eraseblock @lnum will be empty (contain only %0xFF
 592  * bytes) and be mapped to a physical eraseblock, even if an unclean reboot
 593  * happens.
 594  *
 595  * This function returns zero in case of success, %-EBADF if the volume is
 596  * damaged because of an interrupted update, %-EBADMSG if the logical
 597  * eraseblock is already mapped, and other negative error codes in case of
 598  * other failures.
 599  */
 600 int ubi_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype)
 601 {
 602         struct ubi_volume *vol = desc->vol;
 603         struct ubi_device *ubi = vol->ubi;
 604
 605         dbg_gen("unmap LEB %d:%d", vol->vol_id, lnum);
 606
 607         if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
 608                 return -EROFS;
 609
 610         if (lnum < 0 || lnum >= vol->reserved_pebs)
 611                 return -EINVAL;
 612
 613         if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
 614             dtype != UBI_UNKNOWN)
 615                 return -EINVAL;
 616
 617         if (vol->upd_marker)
 618                 return -EBADF;
 619
 620         if (vol->eba_tbl[lnum] >= 0)
 621                 return -EBADMSG;
 622
 623         return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0, dtype);
 624 }
 625 EXPORT_SYMBOL_GPL(ubi_leb_map);
 626
 627 /**
 628  * ubi_is_mapped - check if logical eraseblock is mapped.
 629  * @desc: volume descriptor
 630  * @lnum: logical eraseblock number
 631  *
 632  * This function checks if logical eraseblock @lnum is mapped to a physical
 633  * eraseblock. If a logical eraseblock is un-mapped, this does not necessarily
 634  * mean it will still be un-mapped after the UBI device is re-attached. The
 635  * logical eraseblock may become mapped to the physical eraseblock it was last
 636  * mapped to.
 637  *
 638  * This function returns %1 if the LEB is mapped, %0 if not, and a negative
 639  * error code in case of failure. If the volume is damaged because of an
 640  * interrupted update this function just returns immediately with %-EBADF error
 641  * code.
 642  */
 643 int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum)
 644 {
 645         struct ubi_volume *vol = desc->vol;
 646
 647         dbg_gen("test LEB %d:%d", vol->vol_id, lnum);
 648
 649         if (lnum < 0 || lnum >= vol->reserved_pebs)
 650                 return -EINVAL;
 651
 652         if (vol->upd_marker)
 653                 return -EBADF;
 654
 655         return vol->eba_tbl[lnum] >= 0;
 656 }
 657 EXPORT_SYMBOL_GPL(ubi_is_mapped);
 658
 659 /**
 660  * ubi_sync - synchronize UBI device buffers.
 661  * @ubi_num: UBI device to synchronize
 662  *
 663  * The underlying MTD device may cache data in hardware or in software. This
 664  * function ensures the caches are flushed. Returns zero in case of success and
 665  * a negative error code in case of failure.
 666  */
 667 int ubi_sync(int ubi_num)
 668 {
 669         struct ubi_device *ubi;
 670
 671         ubi = ubi_get_device(ubi_num);
 672         if (!ubi)
 673                 return -ENODEV;
 674
 675         if (ubi->mtd->sync)
 676                 ubi->mtd->sync(ubi->mtd);
 677
 678         ubi_put_device(ubi);
 679         return 0;
 680 }
 681 EXPORT_SYMBOL_GPL(ubi_sync);
 682
 683 BLOCKING_NOTIFIER_HEAD(ubi_notifiers);
 684
 685 /**
 686  * ubi_register_volume_notifier - register a volume notifier.
 687  * @nb: the notifier description object
 688  * @ignore_existing: if non-zero, do not send "added" notification for all
 689  *                   already existing volumes
 690  *
 691  * This function registers a volume notifier, which means that
 692  * 'nb->notifier_call()' will be invoked when an UBI  volume is created,
 693  * removed, re-sized, re-named, or updated. The first argument of the function
 694  * is the notification type. The second argument is pointer to a
 695  * &struct ubi_notification object which describes the notification event.
 696  * Using UBI API from the volume notifier is prohibited.
 697  *
 698  * This function returns zero in case of success and a negative error code
 699  * in case of failure.
 700  */
 701 int ubi_register_volume_notifier(struct notifier_block *nb,
 702                                  int ignore_existing)
 703 {
 704         int err;
 705
 706         err = blocking_notifier_chain_register(&ubi_notifiers, nb);
 707         if (err != 0)
 708                 return err;
 709         if (ignore_existing)
 710                 return 0;
 711
 712         /*
 713          * We are going to walk all UBI devices and all volumes, and
 714          * notify the user about existing volumes by the %UBI_VOLUME_ADDED
 715          * event. We have to lock the @ubi_devices_mutex to make sure UBI
 716          * devices do not disappear.
 717          */
 718         mutex_lock(&ubi_devices_mutex);
 719         ubi_enumerate_volumes(nb);
 720         mutex_unlock(&ubi_devices_mutex);
 721
 722         return err;
 723 }
 724 EXPORT_SYMBOL_GPL(ubi_register_volume_notifier);
 725
 726 /**
 727  * ubi_unregister_volume_notifier - unregister the volume notifier.
 728  * @nb: the notifier description object
 729  *
 730  * This function unregisters volume notifier @nm and returns zero in case of
 731  * success and a negative error code in case of failure.
 732  */
 733 int ubi_unregister_volume_notifier(struct notifier_block *nb)
 734 {
 735         return blocking_notifier_chain_unregister(&ubi_notifiers, nb);
 736 }
 737 EXPORT_SYMBOL_GPL(ubi_unregister_volume_notifier);