2 * Copyright (c) International Business Machines Corp., 2006
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.
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.
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
18 * Author: Artem Bityutskiy (Битюцкий Артём)
21 /* This file mostly implements UBI kernel API functions */
23 #include <linux/module.h>
24 #include <linux/err.h>
25 #include <asm/div64.h>
29 * ubi_get_device_info - get information about UBI device.
30 * @ubi_num: UBI device number
31 * @di: the information is stored here
33 * This function returns %0 in case of success, %-EINVAL if the UBI device
34 * number is invalid, and %-ENODEV if there is no such UBI device.
36 int ubi_get_device_info(int ubi_num, struct ubi_device_info *di)
38 struct ubi_device *ubi;
40 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
43 ubi = ubi_get_device(ubi_num);
47 di->ubi_num = ubi->ubi_num;
48 di->leb_size = ubi->leb_size;
49 di->min_io_size = ubi->min_io_size;
50 di->ro_mode = ubi->ro_mode;
51 di->cdev = ubi->cdev.dev;
56 EXPORT_SYMBOL_GPL(ubi_get_device_info);
59 * ubi_get_volume_info - get information about UBI volume.
60 * @desc: volume descriptor
61 * @vi: the information is stored here
63 void ubi_get_volume_info(struct ubi_volume_desc *desc,
64 struct ubi_volume_info *vi)
66 const struct ubi_volume *vol = desc->vol;
67 const struct ubi_device *ubi = vol->ubi;
69 vi->vol_id = vol->vol_id;
70 vi->ubi_num = ubi->ubi_num;
71 vi->size = vol->reserved_pebs;
72 vi->used_bytes = vol->used_bytes;
73 vi->vol_type = vol->vol_type;
74 vi->corrupted = vol->corrupted;
75 vi->upd_marker = vol->upd_marker;
76 vi->alignment = vol->alignment;
77 vi->usable_leb_size = vol->usable_leb_size;
78 vi->name_len = vol->name_len;
80 vi->cdev = vol->cdev.dev;
82 EXPORT_SYMBOL_GPL(ubi_get_volume_info);
85 * ubi_open_volume - open UBI volume.
86 * @ubi_num: UBI device number
90 * The @mode parameter specifies if the volume should be opened in read-only
91 * mode, read-write mode, or exclusive mode. The exclusive mode guarantees that
92 * nobody else will be able to open this volume. UBI allows to have many volume
93 * readers and one writer at a time.
95 * If a static volume is being opened for the first time since boot, it will be
96 * checked by this function, which means it will be fully read and the CRC
97 * checksum of each logical eraseblock will be checked.
99 * This function returns volume descriptor in case of success and a negative
100 * error code in case of failure.
102 struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode)
105 struct ubi_volume_desc *desc;
106 struct ubi_device *ubi;
107 struct ubi_volume *vol;
109 dbg_msg("open device %d volume %d, mode %d", ubi_num, vol_id, mode);
111 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
112 return ERR_PTR(-EINVAL);
114 if (mode != UBI_READONLY && mode != UBI_READWRITE &&
115 mode != UBI_EXCLUSIVE)
116 return ERR_PTR(-EINVAL);
119 * First of all, we have to get the UBI device to prevent its removal.
121 ubi = ubi_get_device(ubi_num);
123 return ERR_PTR(-ENODEV);
125 if (vol_id < 0 || vol_id >= ubi->vtbl_slots) {
130 desc = kmalloc(sizeof(struct ubi_volume_desc), GFP_KERNEL);
137 if (!try_module_get(THIS_MODULE))
140 spin_lock(&ubi->volumes_lock);
141 vol = ubi->volumes[vol_id];
154 if (vol->exclusive || vol->writers > 0)
160 if (vol->exclusive || vol->writers || vol->readers)
165 get_device(&vol->dev);
167 spin_unlock(&ubi->volumes_lock);
173 * To prevent simultaneous checks of the same volume we use
174 * @volumes_mutex, although it is not the purpose it was introduced
177 mutex_lock(&ubi->volumes_mutex);
179 /* This is the first open - check the volume */
180 err = ubi_check_volume(ubi, vol_id);
182 mutex_unlock(&ubi->volumes_mutex);
183 ubi_close_volume(desc);
187 ubi_warn("volume %d on UBI device %d is corrupted",
188 vol_id, ubi->ubi_num);
193 mutex_unlock(&ubi->volumes_mutex);
198 spin_unlock(&ubi->volumes_lock);
199 module_put(THIS_MODULE);
206 EXPORT_SYMBOL_GPL(ubi_open_volume);
209 * ubi_open_volume_nm - open UBI volume by name.
210 * @ubi_num: UBI device number
214 * This function is similar to 'ubi_open_volume()', but opens a volume by name.
216 struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
219 int i, vol_id = -1, len;
220 struct ubi_device *ubi;
221 struct ubi_volume_desc *ret;
223 dbg_msg("open volume %s, mode %d", name, mode);
226 return ERR_PTR(-EINVAL);
228 len = strnlen(name, UBI_VOL_NAME_MAX + 1);
229 if (len > UBI_VOL_NAME_MAX)
230 return ERR_PTR(-EINVAL);
232 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
233 return ERR_PTR(-EINVAL);
235 ubi = ubi_get_device(ubi_num);
237 return ERR_PTR(-ENODEV);
239 spin_lock(&ubi->volumes_lock);
240 /* Walk all volumes of this UBI device */
241 for (i = 0; i < ubi->vtbl_slots; i++) {
242 struct ubi_volume *vol = ubi->volumes[i];
244 if (vol && len == vol->name_len && !strcmp(name, vol->name)) {
249 spin_unlock(&ubi->volumes_lock);
252 ret = ubi_open_volume(ubi_num, vol_id, mode);
254 ret = ERR_PTR(-ENODEV);
257 * We should put the UBI device even in case of success, because
258 * 'ubi_open_volume()' took a reference as well.
263 EXPORT_SYMBOL_GPL(ubi_open_volume_nm);
266 * ubi_close_volume - close UBI volume.
267 * @desc: volume descriptor
269 void ubi_close_volume(struct ubi_volume_desc *desc)
271 struct ubi_volume *vol = desc->vol;
272 struct ubi_device *ubi = vol->ubi;
274 dbg_msg("close volume %d, mode %d", vol->vol_id, desc->mode);
276 spin_lock(&ubi->volumes_lock);
277 switch (desc->mode) {
288 spin_unlock(&ubi->volumes_lock);
291 put_device(&vol->dev);
293 module_put(THIS_MODULE);
295 EXPORT_SYMBOL_GPL(ubi_close_volume);
298 * ubi_leb_read - read data.
299 * @desc: volume descriptor
300 * @lnum: logical eraseblock number to read from
301 * @buf: buffer where to store the read data
302 * @offset: offset within the logical eraseblock to read from
303 * @len: how many bytes to read
304 * @check: whether UBI has to check the read data's CRC or not.
306 * This function reads data from offset @offset of logical eraseblock @lnum and
307 * stores the data at @buf. When reading from static volumes, @check specifies
308 * whether the data has to be checked or not. If yes, the whole logical
309 * eraseblock will be read and its CRC checksum will be checked (i.e., the CRC
310 * checksum is per-eraseblock). So checking may substantially slow down the
311 * read speed. The @check argument is ignored for dynamic volumes.
313 * In case of success, this function returns zero. In case of failure, this
314 * function returns a negative error code.
316 * %-EBADMSG error code is returned:
317 * o for both static and dynamic volumes if MTD driver has detected a data
318 * integrity problem (unrecoverable ECC checksum mismatch in case of NAND);
319 * o for static volumes in case of data CRC mismatch.
321 * If the volume is damaged because of an interrupted update this function just
322 * returns immediately with %-EBADF error code.
324 int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
327 struct ubi_volume *vol = desc->vol;
328 struct ubi_device *ubi = vol->ubi;
329 int err, vol_id = vol->vol_id;
331 dbg_msg("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset);
333 if (vol_id < 0 || vol_id >= ubi->vtbl_slots || lnum < 0 ||
334 lnum >= vol->used_ebs || offset < 0 || len < 0 ||
335 offset + len > vol->usable_leb_size)
338 if (vol->vol_type == UBI_STATIC_VOLUME) {
339 if (vol->used_ebs == 0)
340 /* Empty static UBI volume */
342 if (lnum == vol->used_ebs - 1 &&
343 offset + len > vol->last_eb_bytes)
352 err = ubi_eba_read_leb(ubi, vol, lnum, buf, offset, len, check);
353 if (err && err == -EBADMSG && vol->vol_type == UBI_STATIC_VOLUME) {
354 ubi_warn("mark volume %d as corrupted", vol_id);
360 EXPORT_SYMBOL_GPL(ubi_leb_read);
363 * ubi_leb_write - write data.
364 * @desc: volume descriptor
365 * @lnum: logical eraseblock number to write to
366 * @buf: data to write
367 * @offset: offset within the logical eraseblock where to write
368 * @len: how many bytes to write
369 * @dtype: expected data type
371 * This function writes @len bytes of data from @buf to offset @offset of
372 * logical eraseblock @lnum. The @dtype argument describes expected lifetime of
375 * This function takes care of physical eraseblock write failures. If write to
376 * the physical eraseblock write operation fails, the logical eraseblock is
377 * re-mapped to another physical eraseblock, the data is recovered, and the
378 * write finishes. UBI has a pool of reserved physical eraseblocks for this.
380 * If all the data were successfully written, zero is returned. If an error
381 * occurred and UBI has not been able to recover from it, this function returns
382 * a negative error code. Note, in case of an error, it is possible that
383 * something was still written to the flash media, but that may be some
386 * If the volume is damaged because of an interrupted update this function just
387 * returns immediately with %-EBADF code.
389 int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
390 int offset, int len, int dtype)
392 struct ubi_volume *vol = desc->vol;
393 struct ubi_device *ubi = vol->ubi;
394 int vol_id = vol->vol_id;
396 dbg_msg("write %d bytes to LEB %d:%d:%d", len, vol_id, lnum, offset);
398 if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
401 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
404 if (lnum < 0 || lnum >= vol->reserved_pebs || offset < 0 || len < 0 ||
405 offset + len > vol->usable_leb_size || offset % ubi->min_io_size ||
406 len % ubi->min_io_size)
409 if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
410 dtype != UBI_UNKNOWN)
419 return ubi_eba_write_leb(ubi, vol, lnum, buf, offset, len, dtype);
421 EXPORT_SYMBOL_GPL(ubi_leb_write);
424 * ubi_leb_change - change logical eraseblock atomically.
425 * @desc: volume descriptor
426 * @lnum: logical eraseblock number to change
427 * @buf: data to write
428 * @len: how many bytes to write
429 * @dtype: expected data type
431 * This function changes the contents of a logical eraseblock atomically. @buf
432 * has to contain new logical eraseblock data, and @len - the length of the
433 * data, which has to be aligned. The length may be shorter then the logical
434 * eraseblock size, ant the logical eraseblock may be appended to more times
435 * later on. This function guarantees that in case of an unclean reboot the old
436 * contents is preserved. Returns zero in case of success and a negative error
437 * code in case of failure.
439 int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
442 struct ubi_volume *vol = desc->vol;
443 struct ubi_device *ubi = vol->ubi;
444 int vol_id = vol->vol_id;
446 dbg_msg("atomically write %d bytes to LEB %d:%d", len, vol_id, lnum);
448 if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
451 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
454 if (lnum < 0 || lnum >= vol->reserved_pebs || len < 0 ||
455 len > vol->usable_leb_size || len % ubi->min_io_size)
458 if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
459 dtype != UBI_UNKNOWN)
468 return ubi_eba_atomic_leb_change(ubi, vol, lnum, buf, len, dtype);
470 EXPORT_SYMBOL_GPL(ubi_leb_change);
473 * ubi_leb_erase - erase logical eraseblock.
474 * @desc: volume descriptor
475 * @lnum: logical eraseblock number
477 * This function un-maps logical eraseblock @lnum and synchronously erases the
478 * correspondent physical eraseblock. Returns zero in case of success and a
479 * negative error code in case of failure.
481 * If the volume is damaged because of an interrupted update this function just
482 * returns immediately with %-EBADF code.
484 int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum)
486 struct ubi_volume *vol = desc->vol;
487 struct ubi_device *ubi = vol->ubi;
488 int err, vol_id = vol->vol_id;
490 dbg_msg("erase LEB %d:%d", vol_id, lnum);
492 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
495 if (lnum < 0 || lnum >= vol->reserved_pebs)
501 err = ubi_eba_unmap_leb(ubi, vol, lnum);
505 return ubi_wl_flush(ubi);
507 EXPORT_SYMBOL_GPL(ubi_leb_erase);
510 * ubi_leb_unmap - un-map logical eraseblock.
511 * @desc: volume descriptor
512 * @lnum: logical eraseblock number
514 * This function un-maps logical eraseblock @lnum and schedules the
515 * corresponding physical eraseblock for erasure, so that it will eventually be
516 * physically erased in background. This operation is much faster then the
519 * Unlike erase, the un-map operation does not guarantee that the logical
520 * eraseblock will contain all 0xFF bytes when UBI is initialized again. For
521 * example, if several logical eraseblocks are un-mapped, and an unclean reboot
522 * happens after this, the logical eraseblocks will not necessarily be
523 * un-mapped again when this MTD device is attached. They may actually be
524 * mapped to the same physical eraseblocks again. So, this function has to be
527 * In other words, when un-mapping a logical eraseblock, UBI does not store
528 * any information about this on the flash media, it just marks the logical
529 * eraseblock as "un-mapped" in RAM. If UBI is detached before the physical
530 * eraseblock is physically erased, it will be mapped again to the same logical
531 * eraseblock when the MTD device is attached again.
533 * The main and obvious use-case of this function is when the contents of a
534 * logical eraseblock has to be re-written. Then it is much more efficient to
535 * first un-map it, then write new data, rather then first erase it, then write
536 * new data. Note, once new data has been written to the logical eraseblock,
537 * UBI guarantees that the old contents has gone forever. In other words, if an
538 * unclean reboot happens after the logical eraseblock has been un-mapped and
539 * then written to, it will contain the last written data.
541 * This function returns zero in case of success and a negative error code in
542 * case of failure. If the volume is damaged because of an interrupted update
543 * this function just returns immediately with %-EBADF code.
545 int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum)
547 struct ubi_volume *vol = desc->vol;
548 struct ubi_device *ubi = vol->ubi;
549 int vol_id = vol->vol_id;
551 dbg_msg("unmap LEB %d:%d", vol_id, lnum);
553 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
556 if (lnum < 0 || lnum >= vol->reserved_pebs)
562 return ubi_eba_unmap_leb(ubi, vol, lnum);
564 EXPORT_SYMBOL_GPL(ubi_leb_unmap);
567 * ubi_leb_map - map logical erasblock to a physical eraseblock.
568 * @desc: volume descriptor
569 * @lnum: logical eraseblock number
570 * @dtype: expected data type
572 * This function maps an un-mapped logical eraseblock @lnum to a physical
573 * eraseblock. This means, that after a successfull invocation of this
574 * function the logical eraseblock @lnum will be empty (contain only %0xFF
575 * bytes) and be mapped to a physical eraseblock, even if an unclean reboot
578 * This function returns zero in case of success, %-EBADF if the volume is
579 * damaged because of an interrupted update, %-EBADMSG if the logical
580 * eraseblock is already mapped, and other negative error codes in case of
583 int ubi_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype)
585 struct ubi_volume *vol = desc->vol;
586 struct ubi_device *ubi = vol->ubi;
587 int vol_id = vol->vol_id;
589 dbg_msg("unmap LEB %d:%d", vol_id, lnum);
591 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
594 if (lnum < 0 || lnum >= vol->reserved_pebs)
597 if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
598 dtype != UBI_UNKNOWN)
604 if (vol->eba_tbl[lnum] >= 0)
607 return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0, dtype);
609 EXPORT_SYMBOL_GPL(ubi_leb_map);
612 * ubi_is_mapped - check if logical eraseblock is mapped.
613 * @desc: volume descriptor
614 * @lnum: logical eraseblock number
616 * This function checks if logical eraseblock @lnum is mapped to a physical
617 * eraseblock. If a logical eraseblock is un-mapped, this does not necessarily
618 * mean it will still be un-mapped after the UBI device is re-attached. The
619 * logical eraseblock may become mapped to the physical eraseblock it was last
622 * This function returns %1 if the LEB is mapped, %0 if not, and a negative
623 * error code in case of failure. If the volume is damaged because of an
624 * interrupted update this function just returns immediately with %-EBADF error
627 int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum)
629 struct ubi_volume *vol = desc->vol;
631 dbg_msg("test LEB %d:%d", vol->vol_id, lnum);
633 if (lnum < 0 || lnum >= vol->reserved_pebs)
639 return vol->eba_tbl[lnum] >= 0;
641 EXPORT_SYMBOL_GPL(ubi_is_mapped);