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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/* This file mostly implements UBI kernel API functions */
9
10#include <linux/module.h>
11#include <linux/err.h>
12#include <linux/slab.h>
13#include <linux/namei.h>
14#include <linux/fs.h>
15#include <asm/div64.h>
16#include "ubi.h"
17
18/**
19 * ubi_do_get_device_info - get information about UBI device.
20 * @ubi: UBI device description object
21 * @di: the information is stored here
22 *
23 * This function is the same as 'ubi_get_device_info()', but it assumes the UBI
24 * device is locked and cannot disappear.
25 */
26void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di)
27{
28 di->ubi_num = ubi->ubi_num;
29 di->leb_size = ubi->leb_size;
30 di->leb_start = ubi->leb_start;
31 di->min_io_size = ubi->min_io_size;
32 di->max_write_size = ubi->max_write_size;
33 di->ro_mode = ubi->ro_mode;
34 di->cdev = ubi->cdev.dev;
35}
36EXPORT_SYMBOL_GPL(ubi_do_get_device_info);
37
38/**
39 * ubi_get_device_info - get information about UBI device.
40 * @ubi_num: UBI device number
41 * @di: the information is stored here
42 *
43 * This function returns %0 in case of success, %-EINVAL if the UBI device
44 * number is invalid, and %-ENODEV if there is no such UBI device.
45 */
46int ubi_get_device_info(int ubi_num, struct ubi_device_info *di)
47{
48 struct ubi_device *ubi;
49
50 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
51 return -EINVAL;
52 ubi = ubi_get_device(ubi_num);
53 if (!ubi)
54 return -ENODEV;
55 ubi_do_get_device_info(ubi, di);
56 ubi_put_device(ubi);
57 return 0;
58}
59EXPORT_SYMBOL_GPL(ubi_get_device_info);
60
61/**
62 * ubi_do_get_volume_info - get information about UBI volume.
63 * @ubi: UBI device description object
64 * @vol: volume description object
65 * @vi: the information is stored here
66 */
67void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
68 struct ubi_volume_info *vi)
69{
70 vi->vol_id = vol->vol_id;
71 vi->ubi_num = ubi->ubi_num;
72 vi->size = vol->reserved_pebs;
73 vi->used_bytes = vol->used_bytes;
74 vi->vol_type = vol->vol_type;
75 vi->corrupted = vol->corrupted;
76 vi->upd_marker = vol->upd_marker;
77 vi->alignment = vol->alignment;
78 vi->usable_leb_size = vol->usable_leb_size;
79 vi->name_len = vol->name_len;
80 vi->name = vol->name;
81 vi->cdev = vol->cdev.dev;
82}
83
84/**
85 * ubi_get_volume_info - get information about UBI volume.
86 * @desc: volume descriptor
87 * @vi: the information is stored here
88 */
89void ubi_get_volume_info(struct ubi_volume_desc *desc,
90 struct ubi_volume_info *vi)
91{
92 ubi_do_get_volume_info(desc->vol->ubi, desc->vol, vi);
93}
94EXPORT_SYMBOL_GPL(ubi_get_volume_info);
95
96/**
97 * ubi_open_volume - open UBI volume.
98 * @ubi_num: UBI device number
99 * @vol_id: volume ID
100 * @mode: open mode
101 *
102 * The @mode parameter specifies if the volume should be opened in read-only
103 * mode, read-write mode, or exclusive mode. The exclusive mode guarantees that
104 * nobody else will be able to open this volume. UBI allows to have many volume
105 * readers and one writer at a time.
106 *
107 * If a static volume is being opened for the first time since boot, it will be
108 * checked by this function, which means it will be fully read and the CRC
109 * checksum of each logical eraseblock will be checked.
110 *
111 * This function returns volume descriptor in case of success and a negative
112 * error code in case of failure.
113 */
114struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode)
115{
116 int err;
117 struct ubi_volume_desc *desc;
118 struct ubi_device *ubi;
119 struct ubi_volume *vol;
120
121 dbg_gen("open device %d, volume %d, mode %d", ubi_num, vol_id, mode);
122
123 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
124 return ERR_PTR(-EINVAL);
125
126 if (mode != UBI_READONLY && mode != UBI_READWRITE &&
127 mode != UBI_EXCLUSIVE && mode != UBI_METAONLY)
128 return ERR_PTR(-EINVAL);
129
130 /*
131 * First of all, we have to get the UBI device to prevent its removal.
132 */
133 ubi = ubi_get_device(ubi_num);
134 if (!ubi)
135 return ERR_PTR(-ENODEV);
136
137 if (vol_id < 0 || vol_id >= ubi->vtbl_slots) {
138 err = -EINVAL;
139 goto out_put_ubi;
140 }
141
142 desc = kmalloc(sizeof(struct ubi_volume_desc), GFP_KERNEL);
143 if (!desc) {
144 err = -ENOMEM;
145 goto out_put_ubi;
146 }
147
148 err = -ENODEV;
149 if (!try_module_get(THIS_MODULE))
150 goto out_free;
151
152 spin_lock(&ubi->volumes_lock);
153 vol = ubi->volumes[vol_id];
154 if (!vol)
155 goto out_unlock;
156
157 err = -EBUSY;
158 switch (mode) {
159 case UBI_READONLY:
160 if (vol->exclusive)
161 goto out_unlock;
162 vol->readers += 1;
163 break;
164
165 case UBI_READWRITE:
166 if (vol->exclusive || vol->writers > 0)
167 goto out_unlock;
168 vol->writers += 1;
169 break;
170
171 case UBI_EXCLUSIVE:
172 if (vol->exclusive || vol->writers || vol->readers ||
173 vol->metaonly)
174 goto out_unlock;
175 vol->exclusive = 1;
176 break;
177
178 case UBI_METAONLY:
179 if (vol->metaonly || vol->exclusive)
180 goto out_unlock;
181 vol->metaonly = 1;
182 break;
183 }
184 get_device(&vol->dev);
185 vol->ref_count += 1;
186 spin_unlock(&ubi->volumes_lock);
187
188 desc->vol = vol;
189 desc->mode = mode;
190
191 mutex_lock(&ubi->ckvol_mutex);
192 if (!vol->checked && !vol->skip_check) {
193 /* This is the first open - check the volume */
194 err = ubi_check_volume(ubi, vol_id);
195 if (err < 0) {
196 mutex_unlock(&ubi->ckvol_mutex);
197 ubi_close_volume(desc);
198 return ERR_PTR(err);
199 }
200 if (err == 1) {
201 ubi_warn(ubi, "volume %d on UBI device %d is corrupted",
202 vol_id, ubi->ubi_num);
203 vol->corrupted = 1;
204 }
205 vol->checked = 1;
206 }
207 mutex_unlock(&ubi->ckvol_mutex);
208
209 return desc;
210
211out_unlock:
212 spin_unlock(&ubi->volumes_lock);
213 module_put(THIS_MODULE);
214out_free:
215 kfree(desc);
216out_put_ubi:
217 ubi_err(ubi, "cannot open device %d, volume %d, error %d",
218 ubi_num, vol_id, err);
219 ubi_put_device(ubi);
220 return ERR_PTR(err);
221}
222EXPORT_SYMBOL_GPL(ubi_open_volume);
223
224/**
225 * ubi_open_volume_nm - open UBI volume by name.
226 * @ubi_num: UBI device number
227 * @name: volume name
228 * @mode: open mode
229 *
230 * This function is similar to 'ubi_open_volume()', but opens a volume by name.
231 */
232struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
233 int mode)
234{
235 int i, vol_id = -1, len;
236 struct ubi_device *ubi;
237 struct ubi_volume_desc *ret;
238
239 dbg_gen("open device %d, volume %s, mode %d", ubi_num, name, mode);
240
241 if (!name)
242 return ERR_PTR(-EINVAL);
243
244 len = strnlen(name, UBI_VOL_NAME_MAX + 1);
245 if (len > UBI_VOL_NAME_MAX)
246 return ERR_PTR(-EINVAL);
247
248 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
249 return ERR_PTR(-EINVAL);
250
251 ubi = ubi_get_device(ubi_num);
252 if (!ubi)
253 return ERR_PTR(-ENODEV);
254
255 spin_lock(&ubi->volumes_lock);
256 /* Walk all volumes of this UBI device */
257 for (i = 0; i < ubi->vtbl_slots; i++) {
258 struct ubi_volume *vol = ubi->volumes[i];
259
260 if (vol && len == vol->name_len && !strcmp(name, vol->name)) {
261 vol_id = i;
262 break;
263 }
264 }
265 spin_unlock(&ubi->volumes_lock);
266
267 if (vol_id >= 0)
268 ret = ubi_open_volume(ubi_num, vol_id, mode);
269 else
270 ret = ERR_PTR(-ENODEV);
271
272 /*
273 * We should put the UBI device even in case of success, because
274 * 'ubi_open_volume()' took a reference as well.
275 */
276 ubi_put_device(ubi);
277 return ret;
278}
279EXPORT_SYMBOL_GPL(ubi_open_volume_nm);
280
281/**
282 * ubi_open_volume_path - open UBI volume by its character device node path.
283 * @pathname: volume character device node path
284 * @mode: open mode
285 *
286 * This function is similar to 'ubi_open_volume()', but opens a volume the path
287 * to its character device node.
288 */
289struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode)
290{
291 int error, ubi_num, vol_id;
292 struct path path;
293 struct kstat stat;
294
295 dbg_gen("open volume %s, mode %d", pathname, mode);
296
297 if (!pathname || !*pathname)
298 return ERR_PTR(-EINVAL);
299
300 error = kern_path(pathname, LOOKUP_FOLLOW, &path);
301 if (error)
302 return ERR_PTR(error);
303
304 error = vfs_getattr(&path, &stat, STATX_TYPE, AT_STATX_SYNC_AS_STAT);
305 path_put(&path);
306 if (error)
307 return ERR_PTR(error);
308
309 if (!S_ISCHR(stat.mode))
310 return ERR_PTR(-EINVAL);
311
312 ubi_num = ubi_major2num(MAJOR(stat.rdev));
313 vol_id = MINOR(stat.rdev) - 1;
314
315 if (vol_id >= 0 && ubi_num >= 0)
316 return ubi_open_volume(ubi_num, vol_id, mode);
317 return ERR_PTR(-ENODEV);
318}
319EXPORT_SYMBOL_GPL(ubi_open_volume_path);
320
321/**
322 * ubi_close_volume - close UBI volume.
323 * @desc: volume descriptor
324 */
325void ubi_close_volume(struct ubi_volume_desc *desc)
326{
327 struct ubi_volume *vol = desc->vol;
328 struct ubi_device *ubi = vol->ubi;
329
330 dbg_gen("close device %d, volume %d, mode %d",
331 ubi->ubi_num, vol->vol_id, desc->mode);
332
333 spin_lock(&ubi->volumes_lock);
334 switch (desc->mode) {
335 case UBI_READONLY:
336 vol->readers -= 1;
337 break;
338 case UBI_READWRITE:
339 vol->writers -= 1;
340 break;
341 case UBI_EXCLUSIVE:
342 vol->exclusive = 0;
343 break;
344 case UBI_METAONLY:
345 vol->metaonly = 0;
346 break;
347 }
348 vol->ref_count -= 1;
349 spin_unlock(&ubi->volumes_lock);
350
351 kfree(desc);
352 put_device(&vol->dev);
353 ubi_put_device(ubi);
354 module_put(THIS_MODULE);
355}
356EXPORT_SYMBOL_GPL(ubi_close_volume);
357
358/**
359 * leb_read_sanity_check - does sanity checks on read requests.
360 * @desc: volume descriptor
361 * @lnum: logical eraseblock number to read from
362 * @offset: offset within the logical eraseblock to read from
363 * @len: how many bytes to read
364 *
365 * This function is used by ubi_leb_read() and ubi_leb_read_sg()
366 * to perform sanity checks.
367 */
368static int leb_read_sanity_check(struct ubi_volume_desc *desc, int lnum,
369 int offset, int len)
370{
371 struct ubi_volume *vol = desc->vol;
372 struct ubi_device *ubi = vol->ubi;
373 int vol_id = vol->vol_id;
374
375 if (vol_id < 0 || vol_id >= ubi->vtbl_slots || lnum < 0 ||
376 lnum >= vol->used_ebs || offset < 0 || len < 0 ||
377 offset + len > vol->usable_leb_size)
378 return -EINVAL;
379
380 if (vol->vol_type == UBI_STATIC_VOLUME) {
381 if (vol->used_ebs == 0)
382 /* Empty static UBI volume */
383 return 0;
384 if (lnum == vol->used_ebs - 1 &&
385 offset + len > vol->last_eb_bytes)
386 return -EINVAL;
387 }
388
389 if (vol->upd_marker)
390 return -EBADF;
391
392 return 0;
393}
394
395/**
396 * ubi_leb_read - read data.
397 * @desc: volume descriptor
398 * @lnum: logical eraseblock number to read from
399 * @buf: buffer where to store the read data
400 * @offset: offset within the logical eraseblock to read from
401 * @len: how many bytes to read
402 * @check: whether UBI has to check the read data's CRC or not.
403 *
404 * This function reads data from offset @offset of logical eraseblock @lnum and
405 * stores the data at @buf. When reading from static volumes, @check specifies
406 * whether the data has to be checked or not. If yes, the whole logical
407 * eraseblock will be read and its CRC checksum will be checked (i.e., the CRC
408 * checksum is per-eraseblock). So checking may substantially slow down the
409 * read speed. The @check argument is ignored for dynamic volumes.
410 *
411 * In case of success, this function returns zero. In case of failure, this
412 * function returns a negative error code.
413 *
414 * %-EBADMSG error code is returned:
415 * o for both static and dynamic volumes if MTD driver has detected a data
416 * integrity problem (unrecoverable ECC checksum mismatch in case of NAND);
417 * o for static volumes in case of data CRC mismatch.
418 *
419 * If the volume is damaged because of an interrupted update this function just
420 * returns immediately with %-EBADF error code.
421 */
422int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
423 int len, int check)
424{
425 struct ubi_volume *vol = desc->vol;
426 struct ubi_device *ubi = vol->ubi;
427 int err, vol_id = vol->vol_id;
428
429 dbg_gen("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset);
430
431 err = leb_read_sanity_check(desc, lnum, offset, len);
432 if (err < 0)
433 return err;
434
435 if (len == 0)
436 return 0;
437
438 err = ubi_eba_read_leb(ubi, vol, lnum, buf, offset, len, check);
439 if (err && mtd_is_eccerr(err) && vol->vol_type == UBI_STATIC_VOLUME) {
440 ubi_warn(ubi, "mark volume %d as corrupted", vol_id);
441 vol->corrupted = 1;
442 }
443
444 return err;
445}
446EXPORT_SYMBOL_GPL(ubi_leb_read);
447
448
449/**
450 * ubi_leb_read_sg - read data into a scatter gather list.
451 * @desc: volume descriptor
452 * @lnum: logical eraseblock number to read from
453 * @buf: buffer where to store the read data
454 * @offset: offset within the logical eraseblock to read from
455 * @len: how many bytes to read
456 * @check: whether UBI has to check the read data's CRC or not.
457 *
458 * This function works exactly like ubi_leb_read_sg(). But instead of
459 * storing the read data into a buffer it writes to an UBI scatter gather
460 * list.
461 */
462int ubi_leb_read_sg(struct ubi_volume_desc *desc, int lnum, struct ubi_sgl *sgl,
463 int offset, int len, int check)
464{
465 struct ubi_volume *vol = desc->vol;
466 struct ubi_device *ubi = vol->ubi;
467 int err, vol_id = vol->vol_id;
468
469 dbg_gen("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset);
470
471 err = leb_read_sanity_check(desc, lnum, offset, len);
472 if (err < 0)
473 return err;
474
475 if (len == 0)
476 return 0;
477
478 err = ubi_eba_read_leb_sg(ubi, vol, sgl, lnum, offset, len, check);
479 if (err && mtd_is_eccerr(err) && vol->vol_type == UBI_STATIC_VOLUME) {
480 ubi_warn(ubi, "mark volume %d as corrupted", vol_id);
481 vol->corrupted = 1;
482 }
483
484 return err;
485}
486EXPORT_SYMBOL_GPL(ubi_leb_read_sg);
487
488/**
489 * ubi_leb_write - write data.
490 * @desc: volume descriptor
491 * @lnum: logical eraseblock number to write to
492 * @buf: data to write
493 * @offset: offset within the logical eraseblock where to write
494 * @len: how many bytes to write
495 *
496 * This function writes @len bytes of data from @buf to offset @offset of
497 * logical eraseblock @lnum.
498 *
499 * This function takes care of physical eraseblock write failures. If write to
500 * the physical eraseblock write operation fails, the logical eraseblock is
501 * re-mapped to another physical eraseblock, the data is recovered, and the
502 * write finishes. UBI has a pool of reserved physical eraseblocks for this.
503 *
504 * If all the data were successfully written, zero is returned. If an error
505 * occurred and UBI has not been able to recover from it, this function returns
506 * a negative error code. Note, in case of an error, it is possible that
507 * something was still written to the flash media, but that may be some
508 * garbage.
509 *
510 * If the volume is damaged because of an interrupted update this function just
511 * returns immediately with %-EBADF code.
512 */
513int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
514 int offset, int len)
515{
516 struct ubi_volume *vol = desc->vol;
517 struct ubi_device *ubi = vol->ubi;
518 int vol_id = vol->vol_id;
519
520 dbg_gen("write %d bytes to LEB %d:%d:%d", len, vol_id, lnum, offset);
521
522 if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
523 return -EINVAL;
524
525 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
526 return -EROFS;
527
528 if (!ubi_leb_valid(vol, lnum) || offset < 0 || len < 0 ||
529 offset + len > vol->usable_leb_size ||
530 offset & (ubi->min_io_size - 1) || len & (ubi->min_io_size - 1))
531 return -EINVAL;
532
533 if (vol->upd_marker)
534 return -EBADF;
535
536 if (len == 0)
537 return 0;
538
539 return ubi_eba_write_leb(ubi, vol, lnum, buf, offset, len);
540}
541EXPORT_SYMBOL_GPL(ubi_leb_write);
542
543/*
544 * ubi_leb_change - change logical eraseblock atomically.
545 * @desc: volume descriptor
546 * @lnum: logical eraseblock number to change
547 * @buf: data to write
548 * @len: how many bytes to write
549 *
550 * This function changes the contents of a logical eraseblock atomically. @buf
551 * has to contain new logical eraseblock data, and @len - the length of the
552 * data, which has to be aligned. The length may be shorter than the logical
553 * eraseblock size, ant the logical eraseblock may be appended to more times
554 * later on. This function guarantees that in case of an unclean reboot the old
555 * contents is preserved. Returns zero in case of success and a negative error
556 * code in case of failure.
557 */
558int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
559 int len)
560{
561 struct ubi_volume *vol = desc->vol;
562 struct ubi_device *ubi = vol->ubi;
563 int vol_id = vol->vol_id;
564
565 dbg_gen("atomically write %d bytes to LEB %d:%d", len, vol_id, lnum);
566
567 if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
568 return -EINVAL;
569
570 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
571 return -EROFS;
572
573 if (!ubi_leb_valid(vol, lnum) || len < 0 ||
574 len > vol->usable_leb_size || len & (ubi->min_io_size - 1))
575 return -EINVAL;
576
577 if (vol->upd_marker)
578 return -EBADF;
579
580 if (len == 0)
581 return 0;
582
583 return ubi_eba_atomic_leb_change(ubi, vol, lnum, buf, len);
584}
585EXPORT_SYMBOL_GPL(ubi_leb_change);
586
587/**
588 * ubi_leb_erase - erase logical eraseblock.
589 * @desc: volume descriptor
590 * @lnum: logical eraseblock number
591 *
592 * This function un-maps logical eraseblock @lnum and synchronously erases the
593 * correspondent physical eraseblock. Returns zero in case of success and a
594 * negative error code in case of failure.
595 *
596 * If the volume is damaged because of an interrupted update this function just
597 * returns immediately with %-EBADF code.
598 */
599int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum)
600{
601 struct ubi_volume *vol = desc->vol;
602 struct ubi_device *ubi = vol->ubi;
603 int err;
604
605 dbg_gen("erase 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 (!ubi_leb_valid(vol, lnum))
611 return -EINVAL;
612
613 if (vol->upd_marker)
614 return -EBADF;
615
616 err = ubi_eba_unmap_leb(ubi, vol, lnum);
617 if (err)
618 return err;
619
620 return ubi_wl_flush(ubi, vol->vol_id, lnum);
621}
622EXPORT_SYMBOL_GPL(ubi_leb_erase);
623
624/**
625 * ubi_leb_unmap - un-map logical eraseblock.
626 * @desc: volume descriptor
627 * @lnum: logical eraseblock number
628 *
629 * This function un-maps logical eraseblock @lnum and schedules the
630 * corresponding physical eraseblock for erasure, so that it will eventually be
631 * physically erased in background. This operation is much faster than the
632 * erase operation.
633 *
634 * Unlike erase, the un-map operation does not guarantee that the logical
635 * eraseblock will contain all 0xFF bytes when UBI is initialized again. For
636 * example, if several logical eraseblocks are un-mapped, and an unclean reboot
637 * happens after this, the logical eraseblocks will not necessarily be
638 * un-mapped again when this MTD device is attached. They may actually be
639 * mapped to the same physical eraseblocks again. So, this function has to be
640 * used with care.
641 *
642 * In other words, when un-mapping a logical eraseblock, UBI does not store
643 * any information about this on the flash media, it just marks the logical
644 * eraseblock as "un-mapped" in RAM. If UBI is detached before the physical
645 * eraseblock is physically erased, it will be mapped again to the same logical
646 * eraseblock when the MTD device is attached again.
647 *
648 * The main and obvious use-case of this function is when the contents of a
649 * logical eraseblock has to be re-written. Then it is much more efficient to
650 * first un-map it, then write new data, rather than first erase it, then write
651 * new data. Note, once new data has been written to the logical eraseblock,
652 * UBI guarantees that the old contents has gone forever. In other words, if an
653 * unclean reboot happens after the logical eraseblock has been un-mapped and
654 * then written to, it will contain the last written data.
655 *
656 * This function returns zero in case of success and a negative error code in
657 * case of failure. If the volume is damaged because of an interrupted update
658 * this function just returns immediately with %-EBADF code.
659 */
660int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum)
661{
662 struct ubi_volume *vol = desc->vol;
663 struct ubi_device *ubi = vol->ubi;
664
665 dbg_gen("unmap LEB %d:%d", vol->vol_id, lnum);
666
667 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
668 return -EROFS;
669
670 if (!ubi_leb_valid(vol, lnum))
671 return -EINVAL;
672
673 if (vol->upd_marker)
674 return -EBADF;
675
676 return ubi_eba_unmap_leb(ubi, vol, lnum);
677}
678EXPORT_SYMBOL_GPL(ubi_leb_unmap);
679
680/**
681 * ubi_leb_map - map logical eraseblock to a physical eraseblock.
682 * @desc: volume descriptor
683 * @lnum: logical eraseblock number
684 *
685 * This function maps an un-mapped logical eraseblock @lnum to a physical
686 * eraseblock. This means, that after a successful invocation of this
687 * function the logical eraseblock @lnum will be empty (contain only %0xFF
688 * bytes) and be mapped to a physical eraseblock, even if an unclean reboot
689 * happens.
690 *
691 * This function returns zero in case of success, %-EBADF if the volume is
692 * damaged because of an interrupted update, %-EBADMSG if the logical
693 * eraseblock is already mapped, and other negative error codes in case of
694 * other failures.
695 */
696int ubi_leb_map(struct ubi_volume_desc *desc, int lnum)
697{
698 struct ubi_volume *vol = desc->vol;
699 struct ubi_device *ubi = vol->ubi;
700
701 dbg_gen("map LEB %d:%d", vol->vol_id, lnum);
702
703 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
704 return -EROFS;
705
706 if (!ubi_leb_valid(vol, lnum))
707 return -EINVAL;
708
709 if (vol->upd_marker)
710 return -EBADF;
711
712 if (ubi_eba_is_mapped(vol, lnum))
713 return -EBADMSG;
714
715 return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0);
716}
717EXPORT_SYMBOL_GPL(ubi_leb_map);
718
719/**
720 * ubi_is_mapped - check if logical eraseblock is mapped.
721 * @desc: volume descriptor
722 * @lnum: logical eraseblock number
723 *
724 * This function checks if logical eraseblock @lnum is mapped to a physical
725 * eraseblock. If a logical eraseblock is un-mapped, this does not necessarily
726 * mean it will still be un-mapped after the UBI device is re-attached. The
727 * logical eraseblock may become mapped to the physical eraseblock it was last
728 * mapped to.
729 *
730 * This function returns %1 if the LEB is mapped, %0 if not, and a negative
731 * error code in case of failure. If the volume is damaged because of an
732 * interrupted update this function just returns immediately with %-EBADF error
733 * code.
734 */
735int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum)
736{
737 struct ubi_volume *vol = desc->vol;
738
739 dbg_gen("test LEB %d:%d", vol->vol_id, lnum);
740
741 if (!ubi_leb_valid(vol, lnum))
742 return -EINVAL;
743
744 if (vol->upd_marker)
745 return -EBADF;
746
747 return ubi_eba_is_mapped(vol, lnum);
748}
749EXPORT_SYMBOL_GPL(ubi_is_mapped);
750
751/**
752 * ubi_sync - synchronize UBI device buffers.
753 * @ubi_num: UBI device to synchronize
754 *
755 * The underlying MTD device may cache data in hardware or in software. This
756 * function ensures the caches are flushed. Returns zero in case of success and
757 * a negative error code in case of failure.
758 */
759int ubi_sync(int ubi_num)
760{
761 struct ubi_device *ubi;
762
763 ubi = ubi_get_device(ubi_num);
764 if (!ubi)
765 return -ENODEV;
766
767 mtd_sync(ubi->mtd);
768 ubi_put_device(ubi);
769 return 0;
770}
771EXPORT_SYMBOL_GPL(ubi_sync);
772
773/**
774 * ubi_flush - flush UBI work queue.
775 * @ubi_num: UBI device to flush work queue
776 * @vol_id: volume id to flush for
777 * @lnum: logical eraseblock number to flush for
778 *
779 * This function executes all pending works for a particular volume id / logical
780 * eraseblock number pair. If either value is set to %UBI_ALL, then it acts as
781 * a wildcard for all of the corresponding volume numbers or logical
782 * eraseblock numbers. It returns zero in case of success and a negative error
783 * code in case of failure.
784 */
785int ubi_flush(int ubi_num, int vol_id, int lnum)
786{
787 struct ubi_device *ubi;
788 int err = 0;
789
790 ubi = ubi_get_device(ubi_num);
791 if (!ubi)
792 return -ENODEV;
793
794 err = ubi_wl_flush(ubi, vol_id, lnum);
795 ubi_put_device(ubi);
796 return err;
797}
798EXPORT_SYMBOL_GPL(ubi_flush);
799
800BLOCKING_NOTIFIER_HEAD(ubi_notifiers);
801
802/**
803 * ubi_register_volume_notifier - register a volume notifier.
804 * @nb: the notifier description object
805 * @ignore_existing: if non-zero, do not send "added" notification for all
806 * already existing volumes
807 *
808 * This function registers a volume notifier, which means that
809 * 'nb->notifier_call()' will be invoked when an UBI volume is created,
810 * removed, re-sized, re-named, or updated. The first argument of the function
811 * is the notification type. The second argument is pointer to a
812 * &struct ubi_notification object which describes the notification event.
813 * Using UBI API from the volume notifier is prohibited.
814 *
815 * This function returns zero in case of success and a negative error code
816 * in case of failure.
817 */
818int ubi_register_volume_notifier(struct notifier_block *nb,
819 int ignore_existing)
820{
821 int err;
822
823 err = blocking_notifier_chain_register(&ubi_notifiers, nb);
824 if (err != 0)
825 return err;
826 if (ignore_existing)
827 return 0;
828
829 /*
830 * We are going to walk all UBI devices and all volumes, and
831 * notify the user about existing volumes by the %UBI_VOLUME_ADDED
832 * event. We have to lock the @ubi_devices_mutex to make sure UBI
833 * devices do not disappear.
834 */
835 mutex_lock(&ubi_devices_mutex);
836 ubi_enumerate_volumes(nb);
837 mutex_unlock(&ubi_devices_mutex);
838
839 return err;
840}
841EXPORT_SYMBOL_GPL(ubi_register_volume_notifier);
842
843/**
844 * ubi_unregister_volume_notifier - unregister the volume notifier.
845 * @nb: the notifier description object
846 *
847 * This function unregisters volume notifier @nm and returns zero in case of
848 * success and a negative error code in case of failure.
849 */
850int ubi_unregister_volume_notifier(struct notifier_block *nb)
851{
852 return blocking_notifier_chain_unregister(&ubi_notifiers, nb);
853}
854EXPORT_SYMBOL_GPL(ubi_unregister_volume_notifier);
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 <linux/slab.h>
26#include <linux/namei.h>
27#include <linux/fs.h>
28#include <asm/div64.h>
29#include "ubi.h"
30
31/**
32 * ubi_do_get_device_info - get information about UBI device.
33 * @ubi: UBI device description object
34 * @di: the information is stored here
35 *
36 * This function is the same as 'ubi_get_device_info()', but it assumes the UBI
37 * device is locked and cannot disappear.
38 */
39void ubi_do_get_device_info(struct ubi_device *ubi, struct ubi_device_info *di)
40{
41 di->ubi_num = ubi->ubi_num;
42 di->leb_size = ubi->leb_size;
43 di->leb_start = ubi->leb_start;
44 di->min_io_size = ubi->min_io_size;
45 di->max_write_size = ubi->max_write_size;
46 di->ro_mode = ubi->ro_mode;
47 di->cdev = ubi->cdev.dev;
48}
49EXPORT_SYMBOL_GPL(ubi_do_get_device_info);
50
51/**
52 * ubi_get_device_info - get information about UBI device.
53 * @ubi_num: UBI device number
54 * @di: the information is stored here
55 *
56 * This function returns %0 in case of success, %-EINVAL if the UBI device
57 * number is invalid, and %-ENODEV if there is no such UBI device.
58 */
59int ubi_get_device_info(int ubi_num, struct ubi_device_info *di)
60{
61 struct ubi_device *ubi;
62
63 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
64 return -EINVAL;
65 ubi = ubi_get_device(ubi_num);
66 if (!ubi)
67 return -ENODEV;
68 ubi_do_get_device_info(ubi, di);
69 ubi_put_device(ubi);
70 return 0;
71}
72EXPORT_SYMBOL_GPL(ubi_get_device_info);
73
74/**
75 * ubi_do_get_volume_info - get information about UBI volume.
76 * @ubi: UBI device description object
77 * @vol: volume description object
78 * @vi: the information is stored here
79 */
80void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
81 struct ubi_volume_info *vi)
82{
83 vi->vol_id = vol->vol_id;
84 vi->ubi_num = ubi->ubi_num;
85 vi->size = vol->reserved_pebs;
86 vi->used_bytes = vol->used_bytes;
87 vi->vol_type = vol->vol_type;
88 vi->corrupted = vol->corrupted;
89 vi->upd_marker = vol->upd_marker;
90 vi->alignment = vol->alignment;
91 vi->usable_leb_size = vol->usable_leb_size;
92 vi->name_len = vol->name_len;
93 vi->name = vol->name;
94 vi->cdev = vol->cdev.dev;
95}
96
97/**
98 * ubi_get_volume_info - get information about UBI volume.
99 * @desc: volume descriptor
100 * @vi: the information is stored here
101 */
102void ubi_get_volume_info(struct ubi_volume_desc *desc,
103 struct ubi_volume_info *vi)
104{
105 ubi_do_get_volume_info(desc->vol->ubi, desc->vol, vi);
106}
107EXPORT_SYMBOL_GPL(ubi_get_volume_info);
108
109/**
110 * ubi_open_volume - open UBI volume.
111 * @ubi_num: UBI device number
112 * @vol_id: volume ID
113 * @mode: open mode
114 *
115 * The @mode parameter specifies if the volume should be opened in read-only
116 * mode, read-write mode, or exclusive mode. The exclusive mode guarantees that
117 * nobody else will be able to open this volume. UBI allows to have many volume
118 * readers and one writer at a time.
119 *
120 * If a static volume is being opened for the first time since boot, it will be
121 * checked by this function, which means it will be fully read and the CRC
122 * checksum of each logical eraseblock will be checked.
123 *
124 * This function returns volume descriptor in case of success and a negative
125 * error code in case of failure.
126 */
127struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode)
128{
129 int err;
130 struct ubi_volume_desc *desc;
131 struct ubi_device *ubi;
132 struct ubi_volume *vol;
133
134 dbg_gen("open device %d, volume %d, mode %d", ubi_num, vol_id, mode);
135
136 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
137 return ERR_PTR(-EINVAL);
138
139 if (mode != UBI_READONLY && mode != UBI_READWRITE &&
140 mode != UBI_EXCLUSIVE)
141 return ERR_PTR(-EINVAL);
142
143 /*
144 * First of all, we have to get the UBI device to prevent its removal.
145 */
146 ubi = ubi_get_device(ubi_num);
147 if (!ubi)
148 return ERR_PTR(-ENODEV);
149
150 if (vol_id < 0 || vol_id >= ubi->vtbl_slots) {
151 err = -EINVAL;
152 goto out_put_ubi;
153 }
154
155 desc = kmalloc(sizeof(struct ubi_volume_desc), GFP_KERNEL);
156 if (!desc) {
157 err = -ENOMEM;
158 goto out_put_ubi;
159 }
160
161 err = -ENODEV;
162 if (!try_module_get(THIS_MODULE))
163 goto out_free;
164
165 spin_lock(&ubi->volumes_lock);
166 vol = ubi->volumes[vol_id];
167 if (!vol)
168 goto out_unlock;
169
170 err = -EBUSY;
171 switch (mode) {
172 case UBI_READONLY:
173 if (vol->exclusive)
174 goto out_unlock;
175 vol->readers += 1;
176 break;
177
178 case UBI_READWRITE:
179 if (vol->exclusive || vol->writers > 0)
180 goto out_unlock;
181 vol->writers += 1;
182 break;
183
184 case UBI_EXCLUSIVE:
185 if (vol->exclusive || vol->writers || vol->readers)
186 goto out_unlock;
187 vol->exclusive = 1;
188 break;
189 }
190 get_device(&vol->dev);
191 vol->ref_count += 1;
192 spin_unlock(&ubi->volumes_lock);
193
194 desc->vol = vol;
195 desc->mode = mode;
196
197 mutex_lock(&ubi->ckvol_mutex);
198 if (!vol->checked) {
199 /* This is the first open - check the volume */
200 err = ubi_check_volume(ubi, vol_id);
201 if (err < 0) {
202 mutex_unlock(&ubi->ckvol_mutex);
203 ubi_close_volume(desc);
204 return ERR_PTR(err);
205 }
206 if (err == 1) {
207 ubi_warn("volume %d on UBI device %d is corrupted",
208 vol_id, ubi->ubi_num);
209 vol->corrupted = 1;
210 }
211 vol->checked = 1;
212 }
213 mutex_unlock(&ubi->ckvol_mutex);
214
215 return desc;
216
217out_unlock:
218 spin_unlock(&ubi->volumes_lock);
219 module_put(THIS_MODULE);
220out_free:
221 kfree(desc);
222out_put_ubi:
223 ubi_put_device(ubi);
224 dbg_err("cannot open device %d, volume %d, error %d",
225 ubi_num, vol_id, err);
226 return ERR_PTR(err);
227}
228EXPORT_SYMBOL_GPL(ubi_open_volume);
229
230/**
231 * ubi_open_volume_nm - open UBI volume by name.
232 * @ubi_num: UBI device number
233 * @name: volume name
234 * @mode: open mode
235 *
236 * This function is similar to 'ubi_open_volume()', but opens a volume by name.
237 */
238struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name,
239 int mode)
240{
241 int i, vol_id = -1, len;
242 struct ubi_device *ubi;
243 struct ubi_volume_desc *ret;
244
245 dbg_gen("open device %d, volume %s, mode %d", ubi_num, name, mode);
246
247 if (!name)
248 return ERR_PTR(-EINVAL);
249
250 len = strnlen(name, UBI_VOL_NAME_MAX + 1);
251 if (len > UBI_VOL_NAME_MAX)
252 return ERR_PTR(-EINVAL);
253
254 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
255 return ERR_PTR(-EINVAL);
256
257 ubi = ubi_get_device(ubi_num);
258 if (!ubi)
259 return ERR_PTR(-ENODEV);
260
261 spin_lock(&ubi->volumes_lock);
262 /* Walk all volumes of this UBI device */
263 for (i = 0; i < ubi->vtbl_slots; i++) {
264 struct ubi_volume *vol = ubi->volumes[i];
265
266 if (vol && len == vol->name_len && !strcmp(name, vol->name)) {
267 vol_id = i;
268 break;
269 }
270 }
271 spin_unlock(&ubi->volumes_lock);
272
273 if (vol_id >= 0)
274 ret = ubi_open_volume(ubi_num, vol_id, mode);
275 else
276 ret = ERR_PTR(-ENODEV);
277
278 /*
279 * We should put the UBI device even in case of success, because
280 * 'ubi_open_volume()' took a reference as well.
281 */
282 ubi_put_device(ubi);
283 return ret;
284}
285EXPORT_SYMBOL_GPL(ubi_open_volume_nm);
286
287/**
288 * ubi_open_volume_path - open UBI volume by its character device node path.
289 * @pathname: volume character device node path
290 * @mode: open mode
291 *
292 * This function is similar to 'ubi_open_volume()', but opens a volume the path
293 * to its character device node.
294 */
295struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode)
296{
297 int error, ubi_num, vol_id, mod;
298 struct inode *inode;
299 struct path path;
300
301 dbg_gen("open volume %s, mode %d", pathname, mode);
302
303 if (!pathname || !*pathname)
304 return ERR_PTR(-EINVAL);
305
306 error = kern_path(pathname, LOOKUP_FOLLOW, &path);
307 if (error)
308 return ERR_PTR(error);
309
310 inode = path.dentry->d_inode;
311 mod = inode->i_mode;
312 ubi_num = ubi_major2num(imajor(inode));
313 vol_id = iminor(inode) - 1;
314 path_put(&path);
315
316 if (!S_ISCHR(mod))
317 return ERR_PTR(-EINVAL);
318 if (vol_id >= 0 && ubi_num >= 0)
319 return ubi_open_volume(ubi_num, vol_id, mode);
320 return ERR_PTR(-ENODEV);
321}
322EXPORT_SYMBOL_GPL(ubi_open_volume_path);
323
324/**
325 * ubi_close_volume - close UBI volume.
326 * @desc: volume descriptor
327 */
328void ubi_close_volume(struct ubi_volume_desc *desc)
329{
330 struct ubi_volume *vol = desc->vol;
331 struct ubi_device *ubi = vol->ubi;
332
333 dbg_gen("close device %d, volume %d, mode %d",
334 ubi->ubi_num, vol->vol_id, desc->mode);
335
336 spin_lock(&ubi->volumes_lock);
337 switch (desc->mode) {
338 case UBI_READONLY:
339 vol->readers -= 1;
340 break;
341 case UBI_READWRITE:
342 vol->writers -= 1;
343 break;
344 case UBI_EXCLUSIVE:
345 vol->exclusive = 0;
346 }
347 vol->ref_count -= 1;
348 spin_unlock(&ubi->volumes_lock);
349
350 kfree(desc);
351 put_device(&vol->dev);
352 ubi_put_device(ubi);
353 module_put(THIS_MODULE);
354}
355EXPORT_SYMBOL_GPL(ubi_close_volume);
356
357/**
358 * ubi_leb_read - read data.
359 * @desc: volume descriptor
360 * @lnum: logical eraseblock number to read from
361 * @buf: buffer where to store the read data
362 * @offset: offset within the logical eraseblock to read from
363 * @len: how many bytes to read
364 * @check: whether UBI has to check the read data's CRC or not.
365 *
366 * This function reads data from offset @offset of logical eraseblock @lnum and
367 * stores the data at @buf. When reading from static volumes, @check specifies
368 * whether the data has to be checked or not. If yes, the whole logical
369 * eraseblock will be read and its CRC checksum will be checked (i.e., the CRC
370 * checksum is per-eraseblock). So checking may substantially slow down the
371 * read speed. The @check argument is ignored for dynamic volumes.
372 *
373 * In case of success, this function returns zero. In case of failure, this
374 * function returns a negative error code.
375 *
376 * %-EBADMSG error code is returned:
377 * o for both static and dynamic volumes if MTD driver has detected a data
378 * integrity problem (unrecoverable ECC checksum mismatch in case of NAND);
379 * o for static volumes in case of data CRC mismatch.
380 *
381 * If the volume is damaged because of an interrupted update this function just
382 * returns immediately with %-EBADF error code.
383 */
384int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
385 int len, int check)
386{
387 struct ubi_volume *vol = desc->vol;
388 struct ubi_device *ubi = vol->ubi;
389 int err, vol_id = vol->vol_id;
390
391 dbg_gen("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset);
392
393 if (vol_id < 0 || vol_id >= ubi->vtbl_slots || lnum < 0 ||
394 lnum >= vol->used_ebs || offset < 0 || len < 0 ||
395 offset + len > vol->usable_leb_size)
396 return -EINVAL;
397
398 if (vol->vol_type == UBI_STATIC_VOLUME) {
399 if (vol->used_ebs == 0)
400 /* Empty static UBI volume */
401 return 0;
402 if (lnum == vol->used_ebs - 1 &&
403 offset + len > vol->last_eb_bytes)
404 return -EINVAL;
405 }
406
407 if (vol->upd_marker)
408 return -EBADF;
409 if (len == 0)
410 return 0;
411
412 err = ubi_eba_read_leb(ubi, vol, lnum, buf, offset, len, check);
413 if (err && err == -EBADMSG && vol->vol_type == UBI_STATIC_VOLUME) {
414 ubi_warn("mark volume %d as corrupted", vol_id);
415 vol->corrupted = 1;
416 }
417
418 return err;
419}
420EXPORT_SYMBOL_GPL(ubi_leb_read);
421
422/**
423 * ubi_leb_write - write data.
424 * @desc: volume descriptor
425 * @lnum: logical eraseblock number to write to
426 * @buf: data to write
427 * @offset: offset within the logical eraseblock where to write
428 * @len: how many bytes to write
429 * @dtype: expected data type
430 *
431 * This function writes @len bytes of data from @buf to offset @offset of
432 * logical eraseblock @lnum. The @dtype argument describes expected lifetime of
433 * the data.
434 *
435 * This function takes care of physical eraseblock write failures. If write to
436 * the physical eraseblock write operation fails, the logical eraseblock is
437 * re-mapped to another physical eraseblock, the data is recovered, and the
438 * write finishes. UBI has a pool of reserved physical eraseblocks for this.
439 *
440 * If all the data were successfully written, zero is returned. If an error
441 * occurred and UBI has not been able to recover from it, this function returns
442 * a negative error code. Note, in case of an error, it is possible that
443 * something was still written to the flash media, but that may be some
444 * garbage.
445 *
446 * If the volume is damaged because of an interrupted update this function just
447 * returns immediately with %-EBADF code.
448 */
449int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
450 int offset, int len, int dtype)
451{
452 struct ubi_volume *vol = desc->vol;
453 struct ubi_device *ubi = vol->ubi;
454 int vol_id = vol->vol_id;
455
456 dbg_gen("write %d bytes to LEB %d:%d:%d", len, vol_id, lnum, offset);
457
458 if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
459 return -EINVAL;
460
461 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
462 return -EROFS;
463
464 if (lnum < 0 || lnum >= vol->reserved_pebs || offset < 0 || len < 0 ||
465 offset + len > vol->usable_leb_size ||
466 offset & (ubi->min_io_size - 1) || len & (ubi->min_io_size - 1))
467 return -EINVAL;
468
469 if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
470 dtype != UBI_UNKNOWN)
471 return -EINVAL;
472
473 if (vol->upd_marker)
474 return -EBADF;
475
476 if (len == 0)
477 return 0;
478
479 return ubi_eba_write_leb(ubi, vol, lnum, buf, offset, len, dtype);
480}
481EXPORT_SYMBOL_GPL(ubi_leb_write);
482
483/*
484 * ubi_leb_change - change logical eraseblock atomically.
485 * @desc: volume descriptor
486 * @lnum: logical eraseblock number to change
487 * @buf: data to write
488 * @len: how many bytes to write
489 * @dtype: expected data type
490 *
491 * This function changes the contents of a logical eraseblock atomically. @buf
492 * has to contain new logical eraseblock data, and @len - the length of the
493 * data, which has to be aligned. The length may be shorter than the logical
494 * eraseblock size, ant the logical eraseblock may be appended to more times
495 * later on. This function guarantees that in case of an unclean reboot the old
496 * contents is preserved. Returns zero in case of success and a negative error
497 * code in case of failure.
498 */
499int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
500 int len, int dtype)
501{
502 struct ubi_volume *vol = desc->vol;
503 struct ubi_device *ubi = vol->ubi;
504 int vol_id = vol->vol_id;
505
506 dbg_gen("atomically write %d bytes to LEB %d:%d", len, vol_id, lnum);
507
508 if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
509 return -EINVAL;
510
511 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
512 return -EROFS;
513
514 if (lnum < 0 || lnum >= vol->reserved_pebs || len < 0 ||
515 len > vol->usable_leb_size || len & (ubi->min_io_size - 1))
516 return -EINVAL;
517
518 if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
519 dtype != UBI_UNKNOWN)
520 return -EINVAL;
521
522 if (vol->upd_marker)
523 return -EBADF;
524
525 if (len == 0)
526 return 0;
527
528 return ubi_eba_atomic_leb_change(ubi, vol, lnum, buf, len, dtype);
529}
530EXPORT_SYMBOL_GPL(ubi_leb_change);
531
532/**
533 * ubi_leb_erase - erase logical eraseblock.
534 * @desc: volume descriptor
535 * @lnum: logical eraseblock number
536 *
537 * This function un-maps logical eraseblock @lnum and synchronously erases the
538 * correspondent physical eraseblock. Returns zero in case of success and a
539 * negative error code in case of failure.
540 *
541 * If the volume is damaged because of an interrupted update this function just
542 * returns immediately with %-EBADF code.
543 */
544int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum)
545{
546 struct ubi_volume *vol = desc->vol;
547 struct ubi_device *ubi = vol->ubi;
548 int err;
549
550 dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
551
552 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
553 return -EROFS;
554
555 if (lnum < 0 || lnum >= vol->reserved_pebs)
556 return -EINVAL;
557
558 if (vol->upd_marker)
559 return -EBADF;
560
561 err = ubi_eba_unmap_leb(ubi, vol, lnum);
562 if (err)
563 return err;
564
565 return ubi_wl_flush(ubi);
566}
567EXPORT_SYMBOL_GPL(ubi_leb_erase);
568
569/**
570 * ubi_leb_unmap - un-map logical eraseblock.
571 * @desc: volume descriptor
572 * @lnum: logical eraseblock number
573 *
574 * This function un-maps logical eraseblock @lnum and schedules the
575 * corresponding physical eraseblock for erasure, so that it will eventually be
576 * physically erased in background. This operation is much faster than the
577 * erase operation.
578 *
579 * Unlike erase, the un-map operation does not guarantee that the logical
580 * eraseblock will contain all 0xFF bytes when UBI is initialized again. For
581 * example, if several logical eraseblocks are un-mapped, and an unclean reboot
582 * happens after this, the logical eraseblocks will not necessarily be
583 * un-mapped again when this MTD device is attached. They may actually be
584 * mapped to the same physical eraseblocks again. So, this function has to be
585 * used with care.
586 *
587 * In other words, when un-mapping a logical eraseblock, UBI does not store
588 * any information about this on the flash media, it just marks the logical
589 * eraseblock as "un-mapped" in RAM. If UBI is detached before the physical
590 * eraseblock is physically erased, it will be mapped again to the same logical
591 * eraseblock when the MTD device is attached again.
592 *
593 * The main and obvious use-case of this function is when the contents of a
594 * logical eraseblock has to be re-written. Then it is much more efficient to
595 * first un-map it, then write new data, rather than first erase it, then write
596 * new data. Note, once new data has been written to the logical eraseblock,
597 * UBI guarantees that the old contents has gone forever. In other words, if an
598 * unclean reboot happens after the logical eraseblock has been un-mapped and
599 * then written to, it will contain the last written data.
600 *
601 * This function returns zero in case of success and a negative error code in
602 * case of failure. If the volume is damaged because of an interrupted update
603 * this function just returns immediately with %-EBADF code.
604 */
605int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum)
606{
607 struct ubi_volume *vol = desc->vol;
608 struct ubi_device *ubi = vol->ubi;
609
610 dbg_gen("unmap LEB %d:%d", vol->vol_id, lnum);
611
612 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
613 return -EROFS;
614
615 if (lnum < 0 || lnum >= vol->reserved_pebs)
616 return -EINVAL;
617
618 if (vol->upd_marker)
619 return -EBADF;
620
621 return ubi_eba_unmap_leb(ubi, vol, lnum);
622}
623EXPORT_SYMBOL_GPL(ubi_leb_unmap);
624
625/**
626 * ubi_leb_map - map logical eraseblock to a physical eraseblock.
627 * @desc: volume descriptor
628 * @lnum: logical eraseblock number
629 * @dtype: expected data type
630 *
631 * This function maps an un-mapped logical eraseblock @lnum to a physical
632 * eraseblock. This means, that after a successful invocation of this
633 * function the logical eraseblock @lnum will be empty (contain only %0xFF
634 * bytes) and be mapped to a physical eraseblock, even if an unclean reboot
635 * happens.
636 *
637 * This function returns zero in case of success, %-EBADF if the volume is
638 * damaged because of an interrupted update, %-EBADMSG if the logical
639 * eraseblock is already mapped, and other negative error codes in case of
640 * other failures.
641 */
642int ubi_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype)
643{
644 struct ubi_volume *vol = desc->vol;
645 struct ubi_device *ubi = vol->ubi;
646
647 dbg_gen("unmap LEB %d:%d", vol->vol_id, lnum);
648
649 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
650 return -EROFS;
651
652 if (lnum < 0 || lnum >= vol->reserved_pebs)
653 return -EINVAL;
654
655 if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
656 dtype != UBI_UNKNOWN)
657 return -EINVAL;
658
659 if (vol->upd_marker)
660 return -EBADF;
661
662 if (vol->eba_tbl[lnum] >= 0)
663 return -EBADMSG;
664
665 return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0, dtype);
666}
667EXPORT_SYMBOL_GPL(ubi_leb_map);
668
669/**
670 * ubi_is_mapped - check if logical eraseblock is mapped.
671 * @desc: volume descriptor
672 * @lnum: logical eraseblock number
673 *
674 * This function checks if logical eraseblock @lnum is mapped to a physical
675 * eraseblock. If a logical eraseblock is un-mapped, this does not necessarily
676 * mean it will still be un-mapped after the UBI device is re-attached. The
677 * logical eraseblock may become mapped to the physical eraseblock it was last
678 * mapped to.
679 *
680 * This function returns %1 if the LEB is mapped, %0 if not, and a negative
681 * error code in case of failure. If the volume is damaged because of an
682 * interrupted update this function just returns immediately with %-EBADF error
683 * code.
684 */
685int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum)
686{
687 struct ubi_volume *vol = desc->vol;
688
689 dbg_gen("test LEB %d:%d", vol->vol_id, lnum);
690
691 if (lnum < 0 || lnum >= vol->reserved_pebs)
692 return -EINVAL;
693
694 if (vol->upd_marker)
695 return -EBADF;
696
697 return vol->eba_tbl[lnum] >= 0;
698}
699EXPORT_SYMBOL_GPL(ubi_is_mapped);
700
701/**
702 * ubi_sync - synchronize UBI device buffers.
703 * @ubi_num: UBI device to synchronize
704 *
705 * The underlying MTD device may cache data in hardware or in software. This
706 * function ensures the caches are flushed. Returns zero in case of success and
707 * a negative error code in case of failure.
708 */
709int ubi_sync(int ubi_num)
710{
711 struct ubi_device *ubi;
712
713 ubi = ubi_get_device(ubi_num);
714 if (!ubi)
715 return -ENODEV;
716
717 if (ubi->mtd->sync)
718 ubi->mtd->sync(ubi->mtd);
719
720 ubi_put_device(ubi);
721 return 0;
722}
723EXPORT_SYMBOL_GPL(ubi_sync);
724
725BLOCKING_NOTIFIER_HEAD(ubi_notifiers);
726
727/**
728 * ubi_register_volume_notifier - register a volume notifier.
729 * @nb: the notifier description object
730 * @ignore_existing: if non-zero, do not send "added" notification for all
731 * already existing volumes
732 *
733 * This function registers a volume notifier, which means that
734 * 'nb->notifier_call()' will be invoked when an UBI volume is created,
735 * removed, re-sized, re-named, or updated. The first argument of the function
736 * is the notification type. The second argument is pointer to a
737 * &struct ubi_notification object which describes the notification event.
738 * Using UBI API from the volume notifier is prohibited.
739 *
740 * This function returns zero in case of success and a negative error code
741 * in case of failure.
742 */
743int ubi_register_volume_notifier(struct notifier_block *nb,
744 int ignore_existing)
745{
746 int err;
747
748 err = blocking_notifier_chain_register(&ubi_notifiers, nb);
749 if (err != 0)
750 return err;
751 if (ignore_existing)
752 return 0;
753
754 /*
755 * We are going to walk all UBI devices and all volumes, and
756 * notify the user about existing volumes by the %UBI_VOLUME_ADDED
757 * event. We have to lock the @ubi_devices_mutex to make sure UBI
758 * devices do not disappear.
759 */
760 mutex_lock(&ubi_devices_mutex);
761 ubi_enumerate_volumes(nb);
762 mutex_unlock(&ubi_devices_mutex);
763
764 return err;
765}
766EXPORT_SYMBOL_GPL(ubi_register_volume_notifier);
767
768/**
769 * ubi_unregister_volume_notifier - unregister the volume notifier.
770 * @nb: the notifier description object
771 *
772 * This function unregisters volume notifier @nm and returns zero in case of
773 * success and a negative error code in case of failure.
774 */
775int ubi_unregister_volume_notifier(struct notifier_block *nb)
776{
777 return blocking_notifier_chain_unregister(&ubi_notifiers, nb);
778}
779EXPORT_SYMBOL_GPL(ubi_unregister_volume_notifier);