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 and a %-ENODEV if there is no
36 int ubi_get_device_info(int ubi_num
, struct ubi_device_info
*di
)
38 const struct ubi_device
*ubi
;
40 if (ubi_num
< 0 || ubi_num
>= UBI_MAX_DEVICES
||
41 !ubi_devices
[ubi_num
])
44 ubi
= ubi_devices
[ubi_num
];
45 di
->ubi_num
= ubi
->ubi_num
;
46 di
->leb_size
= ubi
->leb_size
;
47 di
->min_io_size
= ubi
->min_io_size
;
48 di
->ro_mode
= ubi
->ro_mode
;
49 di
->cdev
= MKDEV(ubi
->major
, 0);
52 EXPORT_SYMBOL_GPL(ubi_get_device_info
);
55 * ubi_get_volume_info - get information about UBI volume.
56 * @desc: volume descriptor
57 * @vi: the information is stored here
59 void ubi_get_volume_info(struct ubi_volume_desc
*desc
,
60 struct ubi_volume_info
*vi
)
62 const struct ubi_volume
*vol
= desc
->vol
;
63 const struct ubi_device
*ubi
= vol
->ubi
;
65 vi
->vol_id
= vol
->vol_id
;
66 vi
->ubi_num
= ubi
->ubi_num
;
67 vi
->size
= vol
->reserved_pebs
;
68 vi
->used_bytes
= vol
->used_bytes
;
69 vi
->vol_type
= vol
->vol_type
;
70 vi
->corrupted
= vol
->corrupted
;
71 vi
->upd_marker
= vol
->upd_marker
;
72 vi
->alignment
= vol
->alignment
;
73 vi
->usable_leb_size
= vol
->usable_leb_size
;
74 vi
->name_len
= vol
->name_len
;
76 vi
->cdev
= MKDEV(ubi
->major
, vi
->vol_id
+ 1);
78 EXPORT_SYMBOL_GPL(ubi_get_volume_info
);
81 * ubi_open_volume - open UBI volume.
82 * @ubi_num: UBI device number
86 * The @mode parameter specifies if the volume should be opened in read-only
87 * mode, read-write mode, or exclusive mode. The exclusive mode guarantees that
88 * nobody else will be able to open this volume. UBI allows to have many volume
89 * readers and one writer at a time.
91 * If a static volume is being opened for the first time since boot, it will be
92 * checked by this function, which means it will be fully read and the CRC
93 * checksum of each logical eraseblock will be checked.
95 * This function returns volume descriptor in case of success and a negative
96 * error code in case of failure.
98 struct ubi_volume_desc
*ubi_open_volume(int ubi_num
, int vol_id
, int mode
)
101 struct ubi_volume_desc
*desc
;
102 struct ubi_device
*ubi
= ubi_devices
[ubi_num
];
103 struct ubi_volume
*vol
;
105 dbg_msg("open device %d volume %d, mode %d", ubi_num
, vol_id
, mode
);
108 if (!try_module_get(THIS_MODULE
))
111 if (ubi_num
< 0 || ubi_num
>= UBI_MAX_DEVICES
|| !ubi
)
115 if (vol_id
< 0 || vol_id
>= ubi
->vtbl_slots
)
117 if (mode
!= UBI_READONLY
&& mode
!= UBI_READWRITE
&&
118 mode
!= UBI_EXCLUSIVE
)
121 desc
= kmalloc(sizeof(struct ubi_volume_desc
), GFP_KERNEL
);
127 spin_lock(&ubi
->volumes_lock
);
128 vol
= ubi
->volumes
[vol_id
];
143 if (vol
->exclusive
|| vol
->writers
> 0)
149 if (vol
->exclusive
|| vol
->writers
|| vol
->readers
)
154 spin_unlock(&ubi
->volumes_lock
);
160 * To prevent simultaneous checks of the same volume we use @vtbl_mutex,
161 * although it is not the purpose it was introduced for.
163 mutex_lock(&ubi
->vtbl_mutex
);
165 /* This is the first open - check the volume */
166 err
= ubi_check_volume(ubi
, vol_id
);
168 mutex_unlock(&ubi
->vtbl_mutex
);
169 ubi_close_volume(desc
);
173 ubi_warn("volume %d on UBI device %d is corrupted",
174 vol_id
, ubi
->ubi_num
);
179 mutex_unlock(&ubi
->vtbl_mutex
);
183 spin_unlock(&ubi
->volumes_lock
);
186 module_put(THIS_MODULE
);
189 EXPORT_SYMBOL_GPL(ubi_open_volume
);
192 * ubi_open_volume_nm - open UBI volume by name.
193 * @ubi_num: UBI device number
197 * This function is similar to 'ubi_open_volume()', but opens a volume by name.
199 struct ubi_volume_desc
*ubi_open_volume_nm(int ubi_num
, const char *name
,
202 int i
, vol_id
= -1, len
;
203 struct ubi_volume_desc
*ret
;
204 struct ubi_device
*ubi
;
206 dbg_msg("open volume %s, mode %d", name
, mode
);
209 return ERR_PTR(-EINVAL
);
211 len
= strnlen(name
, UBI_VOL_NAME_MAX
+ 1);
212 if (len
> UBI_VOL_NAME_MAX
)
213 return ERR_PTR(-EINVAL
);
215 ret
= ERR_PTR(-ENODEV
);
216 if (!try_module_get(THIS_MODULE
))
219 if (ubi_num
< 0 || ubi_num
>= UBI_MAX_DEVICES
|| !ubi_devices
[ubi_num
])
222 ubi
= ubi_devices
[ubi_num
];
224 spin_lock(&ubi
->volumes_lock
);
225 /* Walk all volumes of this UBI device */
226 for (i
= 0; i
< ubi
->vtbl_slots
; i
++) {
227 struct ubi_volume
*vol
= ubi
->volumes
[i
];
229 if (vol
&& len
== vol
->name_len
&& !strcmp(name
, vol
->name
)) {
234 spin_unlock(&ubi
->volumes_lock
);
239 ret
= ubi_open_volume(ubi_num
, vol_id
, mode
);
242 module_put(THIS_MODULE
);
245 EXPORT_SYMBOL_GPL(ubi_open_volume_nm
);
248 * ubi_close_volume - close UBI volume.
249 * @desc: volume descriptor
251 void ubi_close_volume(struct ubi_volume_desc
*desc
)
253 struct ubi_volume
*vol
= desc
->vol
;
255 dbg_msg("close volume %d, mode %d", vol
->vol_id
, desc
->mode
);
257 spin_lock(&vol
->ubi
->volumes_lock
);
258 switch (desc
->mode
) {
268 spin_unlock(&vol
->ubi
->volumes_lock
);
271 module_put(THIS_MODULE
);
273 EXPORT_SYMBOL_GPL(ubi_close_volume
);
276 * ubi_leb_read - read data.
277 * @desc: volume descriptor
278 * @lnum: logical eraseblock number to read from
279 * @buf: buffer where to store the read data
280 * @offset: offset within the logical eraseblock to read from
281 * @len: how many bytes to read
282 * @check: whether UBI has to check the read data's CRC or not.
284 * This function reads data from offset @offset of logical eraseblock @lnum and
285 * stores the data at @buf. When reading from static volumes, @check specifies
286 * whether the data has to be checked or not. If yes, the whole logical
287 * eraseblock will be read and its CRC checksum will be checked (i.e., the CRC
288 * checksum is per-eraseblock). So checking may substantially slow down the
289 * read speed. The @check argument is ignored for dynamic volumes.
291 * In case of success, this function returns zero. In case of failure, this
292 * function returns a negative error code.
294 * %-EBADMSG error code is returned:
295 * o for both static and dynamic volumes if MTD driver has detected a data
296 * integrity problem (unrecoverable ECC checksum mismatch in case of NAND);
297 * o for static volumes in case of data CRC mismatch.
299 * If the volume is damaged because of an interrupted update this function just
300 * returns immediately with %-EBADF error code.
302 int ubi_leb_read(struct ubi_volume_desc
*desc
, int lnum
, char *buf
, int offset
,
305 struct ubi_volume
*vol
= desc
->vol
;
306 struct ubi_device
*ubi
= vol
->ubi
;
307 int err
, vol_id
= vol
->vol_id
;
309 dbg_msg("read %d bytes from LEB %d:%d:%d", len
, vol_id
, lnum
, offset
);
311 if (vol_id
< 0 || vol_id
>= ubi
->vtbl_slots
|| lnum
< 0 ||
312 lnum
>= vol
->used_ebs
|| offset
< 0 || len
< 0 ||
313 offset
+ len
> vol
->usable_leb_size
)
316 if (vol
->vol_type
== UBI_STATIC_VOLUME
) {
317 if (vol
->used_ebs
== 0)
318 /* Empty static UBI volume */
320 if (lnum
== vol
->used_ebs
- 1 &&
321 offset
+ len
> vol
->last_eb_bytes
)
330 err
= ubi_eba_read_leb(ubi
, vol_id
, lnum
, buf
, offset
, len
, check
);
331 if (err
&& err
== -EBADMSG
&& vol
->vol_type
== UBI_STATIC_VOLUME
) {
332 ubi_warn("mark volume %d as corrupted", vol_id
);
338 EXPORT_SYMBOL_GPL(ubi_leb_read
);
341 * ubi_leb_write - write data.
342 * @desc: volume descriptor
343 * @lnum: logical eraseblock number to write to
344 * @buf: data to write
345 * @offset: offset within the logical eraseblock where to write
346 * @len: how many bytes to write
347 * @dtype: expected data type
349 * This function writes @len bytes of data from @buf to offset @offset of
350 * logical eraseblock @lnum. The @dtype argument describes expected lifetime of
353 * This function takes care of physical eraseblock write failures. If write to
354 * the physical eraseblock write operation fails, the logical eraseblock is
355 * re-mapped to another physical eraseblock, the data is recovered, and the
356 * write finishes. UBI has a pool of reserved physical eraseblocks for this.
358 * If all the data were successfully written, zero is returned. If an error
359 * occurred and UBI has not been able to recover from it, this function returns
360 * a negative error code. Note, in case of an error, it is possible that
361 * something was still written to the flash media, but that may be some
364 * If the volume is damaged because of an interrupted update this function just
365 * returns immediately with %-EBADF code.
367 int ubi_leb_write(struct ubi_volume_desc
*desc
, int lnum
, const void *buf
,
368 int offset
, int len
, int dtype
)
370 struct ubi_volume
*vol
= desc
->vol
;
371 struct ubi_device
*ubi
= vol
->ubi
;
372 int vol_id
= vol
->vol_id
;
374 dbg_msg("write %d bytes to LEB %d:%d:%d", len
, vol_id
, lnum
, offset
);
376 if (vol_id
< 0 || vol_id
>= ubi
->vtbl_slots
)
379 if (desc
->mode
== UBI_READONLY
|| vol
->vol_type
== UBI_STATIC_VOLUME
)
382 if (lnum
< 0 || lnum
>= vol
->reserved_pebs
|| offset
< 0 || len
< 0 ||
383 offset
+ len
> vol
->usable_leb_size
|| offset
% ubi
->min_io_size
||
384 len
% ubi
->min_io_size
)
387 if (dtype
!= UBI_LONGTERM
&& dtype
!= UBI_SHORTTERM
&&
388 dtype
!= UBI_UNKNOWN
)
397 return ubi_eba_write_leb(ubi
, vol_id
, lnum
, buf
, offset
, len
, dtype
);
399 EXPORT_SYMBOL_GPL(ubi_leb_write
);
402 * ubi_leb_change - change logical eraseblock atomically.
403 * @desc: volume descriptor
404 * @lnum: logical eraseblock number to change
405 * @buf: data to write
406 * @len: how many bytes to write
407 * @dtype: expected data type
409 * This function changes the contents of a logical eraseblock atomically. @buf
410 * has to contain new logical eraseblock data, and @len - the length of the
411 * data, which has to be aligned. The length may be shorter then the logical
412 * eraseblock size, ant the logical eraseblock may be appended to more times
413 * later on. This function guarantees that in case of an unclean reboot the old
414 * contents is preserved. Returns zero in case of success and a negative error
415 * code in case of failure.
417 int ubi_leb_change(struct ubi_volume_desc
*desc
, int lnum
, const void *buf
,
420 struct ubi_volume
*vol
= desc
->vol
;
421 struct ubi_device
*ubi
= vol
->ubi
;
422 int vol_id
= vol
->vol_id
;
424 dbg_msg("atomically write %d bytes to LEB %d:%d", len
, vol_id
, lnum
);
426 if (vol_id
< 0 || vol_id
>= ubi
->vtbl_slots
)
429 if (desc
->mode
== UBI_READONLY
|| vol
->vol_type
== UBI_STATIC_VOLUME
)
432 if (lnum
< 0 || lnum
>= vol
->reserved_pebs
|| len
< 0 ||
433 len
> vol
->usable_leb_size
|| len
% ubi
->min_io_size
)
436 if (dtype
!= UBI_LONGTERM
&& dtype
!= UBI_SHORTTERM
&&
437 dtype
!= UBI_UNKNOWN
)
446 return ubi_eba_atomic_leb_change(ubi
, vol_id
, lnum
, buf
, len
, dtype
);
448 EXPORT_SYMBOL_GPL(ubi_leb_change
);
451 * ubi_leb_erase - erase logical eraseblock.
452 * @desc: volume descriptor
453 * @lnum: logical eraseblock number
455 * This function un-maps logical eraseblock @lnum and synchronously erases the
456 * correspondent physical eraseblock. Returns zero in case of success and a
457 * negative error code in case of failure.
459 * If the volume is damaged because of an interrupted update this function just
460 * returns immediately with %-EBADF code.
462 int ubi_leb_erase(struct ubi_volume_desc
*desc
, int lnum
)
464 struct ubi_volume
*vol
= desc
->vol
;
465 struct ubi_device
*ubi
= vol
->ubi
;
466 int err
, vol_id
= vol
->vol_id
;
468 dbg_msg("erase LEB %d:%d", vol_id
, lnum
);
470 if (desc
->mode
== UBI_READONLY
|| vol
->vol_type
== UBI_STATIC_VOLUME
)
473 if (lnum
< 0 || lnum
>= vol
->reserved_pebs
)
479 err
= ubi_eba_unmap_leb(ubi
, vol_id
, lnum
);
483 return ubi_wl_flush(ubi
);
485 EXPORT_SYMBOL_GPL(ubi_leb_erase
);
488 * ubi_leb_unmap - un-map logical eraseblock.
489 * @desc: volume descriptor
490 * @lnum: logical eraseblock number
492 * This function un-maps logical eraseblock @lnum and schedules the
493 * corresponding physical eraseblock for erasure, so that it will eventually be
494 * physically erased in background. This operation is much faster then the
497 * Unlike erase, the un-map operation does not guarantee that the logical
498 * eraseblock will contain all 0xFF bytes when UBI is initialized again. For
499 * example, if several logical eraseblocks are un-mapped, and an unclean reboot
500 * happens after this, the logical eraseblocks will not necessarily be
501 * un-mapped again when this MTD device is attached. They may actually be
502 * mapped to the same physical eraseblocks again. So, this function has to be
505 * In other words, when un-mapping a logical eraseblock, UBI does not store
506 * any information about this on the flash media, it just marks the logical
507 * eraseblock as "un-mapped" in RAM. If UBI is detached before the physical
508 * eraseblock is physically erased, it will be mapped again to the same logical
509 * eraseblock when the MTD device is attached again.
511 * The main and obvious use-case of this function is when the contents of a
512 * logical eraseblock has to be re-written. Then it is much more efficient to
513 * first un-map it, then write new data, rather then first erase it, then write
514 * new data. Note, once new data has been written to the logical eraseblock,
515 * UBI guarantees that the old contents has gone forever. In other words, if an
516 * unclean reboot happens after the logical eraseblock has been un-mapped and
517 * then written to, it will contain the last written data.
519 * This function returns zero in case of success and a negative error code in
520 * case of failure. If the volume is damaged because of an interrupted update
521 * this function just returns immediately with %-EBADF code.
523 int ubi_leb_unmap(struct ubi_volume_desc
*desc
, int lnum
)
525 struct ubi_volume
*vol
= desc
->vol
;
526 struct ubi_device
*ubi
= vol
->ubi
;
527 int vol_id
= vol
->vol_id
;
529 dbg_msg("unmap LEB %d:%d", vol_id
, lnum
);
531 if (desc
->mode
== UBI_READONLY
|| vol
->vol_type
== UBI_STATIC_VOLUME
)
534 if (lnum
< 0 || lnum
>= vol
->reserved_pebs
)
540 return ubi_eba_unmap_leb(ubi
, vol_id
, lnum
);
542 EXPORT_SYMBOL_GPL(ubi_leb_unmap
);
545 * ubi_is_mapped - check if logical eraseblock is mapped.
546 * @desc: volume descriptor
547 * @lnum: logical eraseblock number
549 * This function checks if logical eraseblock @lnum is mapped to a physical
550 * eraseblock. If a logical eraseblock is un-mapped, this does not necessarily
551 * mean it will still be un-mapped after the UBI device is re-attached. The
552 * logical eraseblock may become mapped to the physical eraseblock it was last
555 * This function returns %1 if the LEB is mapped, %0 if not, and a negative
556 * error code in case of failure. If the volume is damaged because of an
557 * interrupted update this function just returns immediately with %-EBADF error
560 int ubi_is_mapped(struct ubi_volume_desc
*desc
, int lnum
)
562 struct ubi_volume
*vol
= desc
->vol
;
564 dbg_msg("test LEB %d:%d", vol
->vol_id
, lnum
);
566 if (lnum
< 0 || lnum
>= vol
->reserved_pebs
)
572 return vol
->eba_tbl
[lnum
] >= 0;
574 EXPORT_SYMBOL_GPL(ubi_is_mapped
);