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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 vi->dev = &vol->dev;
83}
84
85/**
86 * ubi_get_volume_info - get information about UBI volume.
87 * @desc: volume descriptor
88 * @vi: the information is stored here
89 */
90void ubi_get_volume_info(struct ubi_volume_desc *desc,
91 struct ubi_volume_info *vi)
92{
93 ubi_do_get_volume_info(desc->vol->ubi, desc->vol, vi);
94}
95EXPORT_SYMBOL_GPL(ubi_get_volume_info);
96
97/**
98 * ubi_open_volume - open UBI volume.
99 * @ubi_num: UBI device number
100 * @vol_id: volume ID
101 * @mode: open mode
102 *
103 * The @mode parameter specifies if the volume should be opened in read-only
104 * mode, read-write mode, or exclusive mode. The exclusive mode guarantees that
105 * nobody else will be able to open this volume. UBI allows to have many volume
106 * readers and one writer at a time.
107 *
108 * If a static volume is being opened for the first time since boot, it will be
109 * checked by this function, which means it will be fully read and the CRC
110 * checksum of each logical eraseblock will be checked.
111 *
112 * This function returns volume descriptor in case of success and a negative
113 * error code in case of failure.
114 */
115struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode)
116{
117 int err;
118 struct ubi_volume_desc *desc;
119 struct ubi_device *ubi;
120 struct ubi_volume *vol;
121
122 dbg_gen("open device %d, volume %d, mode %d", ubi_num, vol_id, mode);
123
124 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
125 return ERR_PTR(-EINVAL);
126
127 if (mode != UBI_READONLY && mode != UBI_READWRITE &&
128 mode != UBI_EXCLUSIVE && mode != UBI_METAONLY)
129 return ERR_PTR(-EINVAL);
130
131 /*
132 * First of all, we have to get the UBI device to prevent its removal.
133 */
134 ubi = ubi_get_device(ubi_num);
135 if (!ubi)
136 return ERR_PTR(-ENODEV);
137
138 if (vol_id < 0 || vol_id >= ubi->vtbl_slots) {
139 err = -EINVAL;
140 goto out_put_ubi;
141 }
142
143 desc = kmalloc(sizeof(struct ubi_volume_desc), GFP_KERNEL);
144 if (!desc) {
145 err = -ENOMEM;
146 goto out_put_ubi;
147 }
148
149 err = -ENODEV;
150 if (!try_module_get(THIS_MODULE))
151 goto out_free;
152
153 spin_lock(&ubi->volumes_lock);
154 vol = ubi->volumes[vol_id];
155 if (!vol)
156 goto out_unlock;
157
158 err = -EBUSY;
159 switch (mode) {
160 case UBI_READONLY:
161 if (vol->exclusive)
162 goto out_unlock;
163 vol->readers += 1;
164 break;
165
166 case UBI_READWRITE:
167 if (vol->exclusive || vol->writers > 0)
168 goto out_unlock;
169 vol->writers += 1;
170 break;
171
172 case UBI_EXCLUSIVE:
173 if (vol->exclusive || vol->writers || vol->readers ||
174 vol->metaonly)
175 goto out_unlock;
176 vol->exclusive = 1;
177 break;
178
179 case UBI_METAONLY:
180 if (vol->metaonly || vol->exclusive)
181 goto out_unlock;
182 vol->metaonly = 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 && !vol->skip_check) {
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(ubi, "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
212out_unlock:
213 spin_unlock(&ubi->volumes_lock);
214 module_put(THIS_MODULE);
215out_free:
216 kfree(desc);
217out_put_ubi:
218 ubi_err(ubi, "cannot open device %d, volume %d, error %d",
219 ubi_num, vol_id, err);
220 ubi_put_device(ubi);
221 return ERR_PTR(err);
222}
223EXPORT_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 */
233struct 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}
280EXPORT_SYMBOL_GPL(ubi_open_volume_nm);
281
282/**
283 * ubi_open_volume_path - open UBI volume by its character device node path.
284 * @pathname: volume character device node path
285 * @mode: open mode
286 *
287 * This function is similar to 'ubi_open_volume()', but opens a volume the path
288 * to its character device node.
289 */
290struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode)
291{
292 int error, ubi_num, vol_id;
293 struct path path;
294 struct kstat stat;
295
296 dbg_gen("open volume %s, mode %d", pathname, mode);
297
298 if (!pathname || !*pathname)
299 return ERR_PTR(-EINVAL);
300
301 error = kern_path(pathname, LOOKUP_FOLLOW, &path);
302 if (error)
303 return ERR_PTR(error);
304
305 error = vfs_getattr(&path, &stat, STATX_TYPE, AT_STATX_SYNC_AS_STAT);
306 path_put(&path);
307 if (error)
308 return ERR_PTR(error);
309
310 if (!S_ISCHR(stat.mode))
311 return ERR_PTR(-EINVAL);
312
313 ubi_num = ubi_major2num(MAJOR(stat.rdev));
314 vol_id = MINOR(stat.rdev) - 1;
315
316 if (vol_id >= 0 && ubi_num >= 0)
317 return ubi_open_volume(ubi_num, vol_id, mode);
318 return ERR_PTR(-ENODEV);
319}
320EXPORT_SYMBOL_GPL(ubi_open_volume_path);
321
322/**
323 * ubi_close_volume - close UBI volume.
324 * @desc: volume descriptor
325 */
326void ubi_close_volume(struct ubi_volume_desc *desc)
327{
328 struct ubi_volume *vol = desc->vol;
329 struct ubi_device *ubi = vol->ubi;
330
331 dbg_gen("close device %d, volume %d, mode %d",
332 ubi->ubi_num, vol->vol_id, desc->mode);
333
334 spin_lock(&ubi->volumes_lock);
335 switch (desc->mode) {
336 case UBI_READONLY:
337 vol->readers -= 1;
338 break;
339 case UBI_READWRITE:
340 vol->writers -= 1;
341 break;
342 case UBI_EXCLUSIVE:
343 vol->exclusive = 0;
344 break;
345 case UBI_METAONLY:
346 vol->metaonly = 0;
347 break;
348 }
349 vol->ref_count -= 1;
350 spin_unlock(&ubi->volumes_lock);
351
352 kfree(desc);
353 put_device(&vol->dev);
354 ubi_put_device(ubi);
355 module_put(THIS_MODULE);
356}
357EXPORT_SYMBOL_GPL(ubi_close_volume);
358
359/**
360 * leb_read_sanity_check - does sanity checks on read requests.
361 * @desc: volume descriptor
362 * @lnum: logical eraseblock number to read from
363 * @offset: offset within the logical eraseblock to read from
364 * @len: how many bytes to read
365 *
366 * This function is used by ubi_leb_read() and ubi_leb_read_sg()
367 * to perform sanity checks.
368 */
369static int leb_read_sanity_check(struct ubi_volume_desc *desc, int lnum,
370 int offset, int len)
371{
372 struct ubi_volume *vol = desc->vol;
373 struct ubi_device *ubi = vol->ubi;
374 int vol_id = vol->vol_id;
375
376 if (vol_id < 0 || vol_id >= ubi->vtbl_slots || lnum < 0 ||
377 lnum >= vol->used_ebs || offset < 0 || len < 0 ||
378 offset + len > vol->usable_leb_size)
379 return -EINVAL;
380
381 if (vol->vol_type == UBI_STATIC_VOLUME) {
382 if (vol->used_ebs == 0)
383 /* Empty static UBI volume */
384 return 0;
385 if (lnum == vol->used_ebs - 1 &&
386 offset + len > vol->last_eb_bytes)
387 return -EINVAL;
388 }
389
390 if (vol->upd_marker)
391 return -EBADF;
392
393 return 0;
394}
395
396/**
397 * ubi_leb_read - read data.
398 * @desc: volume descriptor
399 * @lnum: logical eraseblock number to read from
400 * @buf: buffer where to store the read data
401 * @offset: offset within the logical eraseblock to read from
402 * @len: how many bytes to read
403 * @check: whether UBI has to check the read data's CRC or not.
404 *
405 * This function reads data from offset @offset of logical eraseblock @lnum and
406 * stores the data at @buf. When reading from static volumes, @check specifies
407 * whether the data has to be checked or not. If yes, the whole logical
408 * eraseblock will be read and its CRC checksum will be checked (i.e., the CRC
409 * checksum is per-eraseblock). So checking may substantially slow down the
410 * read speed. The @check argument is ignored for dynamic volumes.
411 *
412 * In case of success, this function returns zero. In case of failure, this
413 * function returns a negative error code.
414 *
415 * %-EBADMSG error code is returned:
416 * o for both static and dynamic volumes if MTD driver has detected a data
417 * integrity problem (unrecoverable ECC checksum mismatch in case of NAND);
418 * o for static volumes in case of data CRC mismatch.
419 *
420 * If the volume is damaged because of an interrupted update this function just
421 * returns immediately with %-EBADF error code.
422 */
423int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
424 int len, int check)
425{
426 struct ubi_volume *vol = desc->vol;
427 struct ubi_device *ubi = vol->ubi;
428 int err, vol_id = vol->vol_id;
429
430 dbg_gen("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset);
431
432 err = leb_read_sanity_check(desc, lnum, offset, len);
433 if (err < 0)
434 return err;
435
436 if (len == 0)
437 return 0;
438
439 err = ubi_eba_read_leb(ubi, vol, lnum, buf, offset, len, check);
440 if (err && mtd_is_eccerr(err) && vol->vol_type == UBI_STATIC_VOLUME) {
441 ubi_warn(ubi, "mark volume %d as corrupted", vol_id);
442 vol->corrupted = 1;
443 }
444
445 return err;
446}
447EXPORT_SYMBOL_GPL(ubi_leb_read);
448
449
450/**
451 * ubi_leb_read_sg - read data into a scatter gather list.
452 * @desc: volume descriptor
453 * @lnum: logical eraseblock number to read from
454 * @sgl: UBI scatter gather list to store the read data
455 * @offset: offset within the logical eraseblock to read from
456 * @len: how many bytes to read
457 * @check: whether UBI has to check the read data's CRC or not.
458 *
459 * This function works exactly like ubi_leb_read_sg(). But instead of
460 * storing the read data into a buffer it writes to an UBI scatter gather
461 * list.
462 */
463int ubi_leb_read_sg(struct ubi_volume_desc *desc, int lnum, struct ubi_sgl *sgl,
464 int offset, int len, int check)
465{
466 struct ubi_volume *vol = desc->vol;
467 struct ubi_device *ubi = vol->ubi;
468 int err, vol_id = vol->vol_id;
469
470 dbg_gen("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset);
471
472 err = leb_read_sanity_check(desc, lnum, offset, len);
473 if (err < 0)
474 return err;
475
476 if (len == 0)
477 return 0;
478
479 err = ubi_eba_read_leb_sg(ubi, vol, sgl, lnum, offset, len, check);
480 if (err && mtd_is_eccerr(err) && vol->vol_type == UBI_STATIC_VOLUME) {
481 ubi_warn(ubi, "mark volume %d as corrupted", vol_id);
482 vol->corrupted = 1;
483 }
484
485 return err;
486}
487EXPORT_SYMBOL_GPL(ubi_leb_read_sg);
488
489/**
490 * ubi_leb_write - write data.
491 * @desc: volume descriptor
492 * @lnum: logical eraseblock number to write to
493 * @buf: data to write
494 * @offset: offset within the logical eraseblock where to write
495 * @len: how many bytes to write
496 *
497 * This function writes @len bytes of data from @buf to offset @offset of
498 * logical eraseblock @lnum.
499 *
500 * This function takes care of physical eraseblock write failures. If write to
501 * the physical eraseblock write operation fails, the logical eraseblock is
502 * re-mapped to another physical eraseblock, the data is recovered, and the
503 * write finishes. UBI has a pool of reserved physical eraseblocks for this.
504 *
505 * If all the data were successfully written, zero is returned. If an error
506 * occurred and UBI has not been able to recover from it, this function returns
507 * a negative error code. Note, in case of an error, it is possible that
508 * something was still written to the flash media, but that may be some
509 * garbage.
510 *
511 * If the volume is damaged because of an interrupted update this function just
512 * returns immediately with %-EBADF code.
513 */
514int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
515 int offset, int len)
516{
517 struct ubi_volume *vol = desc->vol;
518 struct ubi_device *ubi = vol->ubi;
519 int vol_id = vol->vol_id;
520
521 dbg_gen("write %d bytes to LEB %d:%d:%d", len, vol_id, lnum, offset);
522
523 if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
524 return -EINVAL;
525
526 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
527 return -EROFS;
528
529 if (!ubi_leb_valid(vol, lnum) || offset < 0 || len < 0 ||
530 offset + len > vol->usable_leb_size ||
531 offset & (ubi->min_io_size - 1) || len & (ubi->min_io_size - 1))
532 return -EINVAL;
533
534 if (vol->upd_marker)
535 return -EBADF;
536
537 if (len == 0)
538 return 0;
539
540 return ubi_eba_write_leb(ubi, vol, lnum, buf, offset, len);
541}
542EXPORT_SYMBOL_GPL(ubi_leb_write);
543
544/*
545 * ubi_leb_change - change logical eraseblock atomically.
546 * @desc: volume descriptor
547 * @lnum: logical eraseblock number to change
548 * @buf: data to write
549 * @len: how many bytes to write
550 *
551 * This function changes the contents of a logical eraseblock atomically. @buf
552 * has to contain new logical eraseblock data, and @len - the length of the
553 * data, which has to be aligned. The length may be shorter than the logical
554 * eraseblock size, ant the logical eraseblock may be appended to more times
555 * later on. This function guarantees that in case of an unclean reboot the old
556 * contents is preserved. Returns zero in case of success and a negative error
557 * code in case of failure.
558 */
559int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
560 int len)
561{
562 struct ubi_volume *vol = desc->vol;
563 struct ubi_device *ubi = vol->ubi;
564 int vol_id = vol->vol_id;
565
566 dbg_gen("atomically write %d bytes to LEB %d:%d", len, vol_id, lnum);
567
568 if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
569 return -EINVAL;
570
571 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
572 return -EROFS;
573
574 if (!ubi_leb_valid(vol, lnum) || len < 0 ||
575 len > vol->usable_leb_size || len & (ubi->min_io_size - 1))
576 return -EINVAL;
577
578 if (vol->upd_marker)
579 return -EBADF;
580
581 if (len == 0)
582 return 0;
583
584 return ubi_eba_atomic_leb_change(ubi, vol, lnum, buf, len);
585}
586EXPORT_SYMBOL_GPL(ubi_leb_change);
587
588/**
589 * ubi_leb_erase - erase logical eraseblock.
590 * @desc: volume descriptor
591 * @lnum: logical eraseblock number
592 *
593 * This function un-maps logical eraseblock @lnum and synchronously erases the
594 * correspondent physical eraseblock. Returns zero in case of success and a
595 * negative error code in case of failure.
596 *
597 * If the volume is damaged because of an interrupted update this function just
598 * returns immediately with %-EBADF code.
599 */
600int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum)
601{
602 struct ubi_volume *vol = desc->vol;
603 struct ubi_device *ubi = vol->ubi;
604 int err;
605
606 dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
607
608 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
609 return -EROFS;
610
611 if (!ubi_leb_valid(vol, lnum))
612 return -EINVAL;
613
614 if (vol->upd_marker)
615 return -EBADF;
616
617 err = ubi_eba_unmap_leb(ubi, vol, lnum);
618 if (err)
619 return err;
620
621 return ubi_wl_flush(ubi, vol->vol_id, lnum);
622}
623EXPORT_SYMBOL_GPL(ubi_leb_erase);
624
625/**
626 * ubi_leb_unmap - un-map logical eraseblock.
627 * @desc: volume descriptor
628 * @lnum: logical eraseblock number
629 *
630 * This function un-maps logical eraseblock @lnum and schedules the
631 * corresponding physical eraseblock for erasure, so that it will eventually be
632 * physically erased in background. This operation is much faster than the
633 * erase operation.
634 *
635 * Unlike erase, the un-map operation does not guarantee that the logical
636 * eraseblock will contain all 0xFF bytes when UBI is initialized again. For
637 * example, if several logical eraseblocks are un-mapped, and an unclean reboot
638 * happens after this, the logical eraseblocks will not necessarily be
639 * un-mapped again when this MTD device is attached. They may actually be
640 * mapped to the same physical eraseblocks again. So, this function has to be
641 * used with care.
642 *
643 * In other words, when un-mapping a logical eraseblock, UBI does not store
644 * any information about this on the flash media, it just marks the logical
645 * eraseblock as "un-mapped" in RAM. If UBI is detached before the physical
646 * eraseblock is physically erased, it will be mapped again to the same logical
647 * eraseblock when the MTD device is attached again.
648 *
649 * The main and obvious use-case of this function is when the contents of a
650 * logical eraseblock has to be re-written. Then it is much more efficient to
651 * first un-map it, then write new data, rather than first erase it, then write
652 * new data. Note, once new data has been written to the logical eraseblock,
653 * UBI guarantees that the old contents has gone forever. In other words, if an
654 * unclean reboot happens after the logical eraseblock has been un-mapped and
655 * then written to, it will contain the last written data.
656 *
657 * This function returns zero in case of success and a negative error code in
658 * case of failure. If the volume is damaged because of an interrupted update
659 * this function just returns immediately with %-EBADF code.
660 */
661int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum)
662{
663 struct ubi_volume *vol = desc->vol;
664 struct ubi_device *ubi = vol->ubi;
665
666 dbg_gen("unmap LEB %d:%d", vol->vol_id, lnum);
667
668 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
669 return -EROFS;
670
671 if (!ubi_leb_valid(vol, lnum))
672 return -EINVAL;
673
674 if (vol->upd_marker)
675 return -EBADF;
676
677 return ubi_eba_unmap_leb(ubi, vol, lnum);
678}
679EXPORT_SYMBOL_GPL(ubi_leb_unmap);
680
681/**
682 * ubi_leb_map - map logical eraseblock to a physical eraseblock.
683 * @desc: volume descriptor
684 * @lnum: logical eraseblock number
685 *
686 * This function maps an un-mapped logical eraseblock @lnum to a physical
687 * eraseblock. This means, that after a successful invocation of this
688 * function the logical eraseblock @lnum will be empty (contain only %0xFF
689 * bytes) and be mapped to a physical eraseblock, even if an unclean reboot
690 * happens.
691 *
692 * This function returns zero in case of success, %-EBADF if the volume is
693 * damaged because of an interrupted update, %-EBADMSG if the logical
694 * eraseblock is already mapped, and other negative error codes in case of
695 * other failures.
696 */
697int ubi_leb_map(struct ubi_volume_desc *desc, int lnum)
698{
699 struct ubi_volume *vol = desc->vol;
700 struct ubi_device *ubi = vol->ubi;
701
702 dbg_gen("map LEB %d:%d", vol->vol_id, lnum);
703
704 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
705 return -EROFS;
706
707 if (!ubi_leb_valid(vol, lnum))
708 return -EINVAL;
709
710 if (vol->upd_marker)
711 return -EBADF;
712
713 if (ubi_eba_is_mapped(vol, lnum))
714 return -EBADMSG;
715
716 return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0);
717}
718EXPORT_SYMBOL_GPL(ubi_leb_map);
719
720/**
721 * ubi_is_mapped - check if logical eraseblock is mapped.
722 * @desc: volume descriptor
723 * @lnum: logical eraseblock number
724 *
725 * This function checks if logical eraseblock @lnum is mapped to a physical
726 * eraseblock. If a logical eraseblock is un-mapped, this does not necessarily
727 * mean it will still be un-mapped after the UBI device is re-attached. The
728 * logical eraseblock may become mapped to the physical eraseblock it was last
729 * mapped to.
730 *
731 * This function returns %1 if the LEB is mapped, %0 if not, and a negative
732 * error code in case of failure. If the volume is damaged because of an
733 * interrupted update this function just returns immediately with %-EBADF error
734 * code.
735 */
736int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum)
737{
738 struct ubi_volume *vol = desc->vol;
739
740 dbg_gen("test LEB %d:%d", vol->vol_id, lnum);
741
742 if (!ubi_leb_valid(vol, lnum))
743 return -EINVAL;
744
745 if (vol->upd_marker)
746 return -EBADF;
747
748 return ubi_eba_is_mapped(vol, lnum);
749}
750EXPORT_SYMBOL_GPL(ubi_is_mapped);
751
752/**
753 * ubi_sync - synchronize UBI device buffers.
754 * @ubi_num: UBI device to synchronize
755 *
756 * The underlying MTD device may cache data in hardware or in software. This
757 * function ensures the caches are flushed. Returns zero in case of success and
758 * a negative error code in case of failure.
759 */
760int ubi_sync(int ubi_num)
761{
762 struct ubi_device *ubi;
763
764 ubi = ubi_get_device(ubi_num);
765 if (!ubi)
766 return -ENODEV;
767
768 mtd_sync(ubi->mtd);
769 ubi_put_device(ubi);
770 return 0;
771}
772EXPORT_SYMBOL_GPL(ubi_sync);
773
774/**
775 * ubi_flush - flush UBI work queue.
776 * @ubi_num: UBI device to flush work queue
777 * @vol_id: volume id to flush for
778 * @lnum: logical eraseblock number to flush for
779 *
780 * This function executes all pending works for a particular volume id / logical
781 * eraseblock number pair. If either value is set to %UBI_ALL, then it acts as
782 * a wildcard for all of the corresponding volume numbers or logical
783 * eraseblock numbers. It returns zero in case of success and a negative error
784 * code in case of failure.
785 */
786int ubi_flush(int ubi_num, int vol_id, int lnum)
787{
788 struct ubi_device *ubi;
789 int err = 0;
790
791 ubi = ubi_get_device(ubi_num);
792 if (!ubi)
793 return -ENODEV;
794
795 err = ubi_wl_flush(ubi, vol_id, lnum);
796 ubi_put_device(ubi);
797 return err;
798}
799EXPORT_SYMBOL_GPL(ubi_flush);
800
801BLOCKING_NOTIFIER_HEAD(ubi_notifiers);
802
803/**
804 * ubi_register_volume_notifier - register a volume notifier.
805 * @nb: the notifier description object
806 * @ignore_existing: if non-zero, do not send "added" notification for all
807 * already existing volumes
808 *
809 * This function registers a volume notifier, which means that
810 * 'nb->notifier_call()' will be invoked when an UBI volume is created,
811 * removed, re-sized, re-named, or updated. The first argument of the function
812 * is the notification type. The second argument is pointer to a
813 * &struct ubi_notification object which describes the notification event.
814 * Using UBI API from the volume notifier is prohibited.
815 *
816 * This function returns zero in case of success and a negative error code
817 * in case of failure.
818 */
819int ubi_register_volume_notifier(struct notifier_block *nb,
820 int ignore_existing)
821{
822 int err;
823
824 err = blocking_notifier_chain_register(&ubi_notifiers, nb);
825 if (err != 0)
826 return err;
827 if (ignore_existing)
828 return 0;
829
830 /*
831 * We are going to walk all UBI devices and all volumes, and
832 * notify the user about existing volumes by the %UBI_VOLUME_ADDED
833 * event. We have to lock the @ubi_devices_mutex to make sure UBI
834 * devices do not disappear.
835 */
836 mutex_lock(&ubi_devices_mutex);
837 ubi_enumerate_volumes(nb);
838 mutex_unlock(&ubi_devices_mutex);
839
840 return err;
841}
842EXPORT_SYMBOL_GPL(ubi_register_volume_notifier);
843
844/**
845 * ubi_unregister_volume_notifier - unregister the volume notifier.
846 * @nb: the notifier description object
847 *
848 * This function unregisters volume notifier @nm and returns zero in case of
849 * success and a negative error code in case of failure.
850 */
851int ubi_unregister_volume_notifier(struct notifier_block *nb)
852{
853 return blocking_notifier_chain_unregister(&ubi_notifiers, nb);
854}
855EXPORT_SYMBOL_GPL(ubi_unregister_volume_notifier);
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 vi->dev = &vol->dev;
83}
84
85/**
86 * ubi_get_volume_info - get information about UBI volume.
87 * @desc: volume descriptor
88 * @vi: the information is stored here
89 */
90void ubi_get_volume_info(struct ubi_volume_desc *desc,
91 struct ubi_volume_info *vi)
92{
93 ubi_do_get_volume_info(desc->vol->ubi, desc->vol, vi);
94}
95EXPORT_SYMBOL_GPL(ubi_get_volume_info);
96
97/**
98 * ubi_open_volume - open UBI volume.
99 * @ubi_num: UBI device number
100 * @vol_id: volume ID
101 * @mode: open mode
102 *
103 * The @mode parameter specifies if the volume should be opened in read-only
104 * mode, read-write mode, or exclusive mode. The exclusive mode guarantees that
105 * nobody else will be able to open this volume. UBI allows to have many volume
106 * readers and one writer at a time.
107 *
108 * If a static volume is being opened for the first time since boot, it will be
109 * checked by this function, which means it will be fully read and the CRC
110 * checksum of each logical eraseblock will be checked.
111 *
112 * This function returns volume descriptor in case of success and a negative
113 * error code in case of failure.
114 */
115struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode)
116{
117 int err;
118 struct ubi_volume_desc *desc;
119 struct ubi_device *ubi;
120 struct ubi_volume *vol;
121
122 dbg_gen("open device %d, volume %d, mode %d", ubi_num, vol_id, mode);
123
124 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
125 return ERR_PTR(-EINVAL);
126
127 if (mode != UBI_READONLY && mode != UBI_READWRITE &&
128 mode != UBI_EXCLUSIVE && mode != UBI_METAONLY)
129 return ERR_PTR(-EINVAL);
130
131 /*
132 * First of all, we have to get the UBI device to prevent its removal.
133 */
134 ubi = ubi_get_device(ubi_num);
135 if (!ubi)
136 return ERR_PTR(-ENODEV);
137
138 if (vol_id < 0 || vol_id >= ubi->vtbl_slots) {
139 err = -EINVAL;
140 goto out_put_ubi;
141 }
142
143 desc = kmalloc(sizeof(struct ubi_volume_desc), GFP_KERNEL);
144 if (!desc) {
145 err = -ENOMEM;
146 goto out_put_ubi;
147 }
148
149 err = -ENODEV;
150 if (!try_module_get(THIS_MODULE))
151 goto out_free;
152
153 spin_lock(&ubi->volumes_lock);
154 vol = ubi->volumes[vol_id];
155 if (!vol || vol->is_dead)
156 goto out_unlock;
157
158 err = -EBUSY;
159 switch (mode) {
160 case UBI_READONLY:
161 if (vol->exclusive)
162 goto out_unlock;
163 vol->readers += 1;
164 break;
165
166 case UBI_READWRITE:
167 if (vol->exclusive || vol->writers > 0)
168 goto out_unlock;
169 vol->writers += 1;
170 break;
171
172 case UBI_EXCLUSIVE:
173 if (vol->exclusive || vol->writers || vol->readers ||
174 vol->metaonly)
175 goto out_unlock;
176 vol->exclusive = 1;
177 break;
178
179 case UBI_METAONLY:
180 if (vol->metaonly || vol->exclusive)
181 goto out_unlock;
182 vol->metaonly = 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 && !vol->skip_check) {
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(ubi, "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
212out_unlock:
213 spin_unlock(&ubi->volumes_lock);
214 module_put(THIS_MODULE);
215out_free:
216 kfree(desc);
217out_put_ubi:
218 ubi_err(ubi, "cannot open device %d, volume %d, error %d",
219 ubi_num, vol_id, err);
220 ubi_put_device(ubi);
221 return ERR_PTR(err);
222}
223EXPORT_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 */
233struct 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}
280EXPORT_SYMBOL_GPL(ubi_open_volume_nm);
281
282/**
283 * ubi_get_num_by_path - get UBI device and volume number from device path
284 * @pathname: volume character device node path
285 * @ubi_num: pointer to UBI device number to be set
286 * @vol_id: pointer to UBI volume ID to be set
287 *
288 * Returns 0 on success and sets ubi_num and vol_id, returns error otherwise.
289 */
290int ubi_get_num_by_path(const char *pathname, int *ubi_num, int *vol_id)
291{
292 int error;
293 struct path path;
294 struct kstat stat;
295
296 error = kern_path(pathname, LOOKUP_FOLLOW, &path);
297 if (error)
298 return error;
299
300 error = vfs_getattr(&path, &stat, STATX_TYPE, AT_STATX_SYNC_AS_STAT);
301 path_put(&path);
302 if (error)
303 return error;
304
305 if (!S_ISCHR(stat.mode))
306 return -EINVAL;
307
308 *ubi_num = ubi_major2num(MAJOR(stat.rdev));
309 *vol_id = MINOR(stat.rdev) - 1;
310
311 if (*vol_id < 0 || *ubi_num < 0)
312 return -ENODEV;
313
314 return 0;
315}
316
317/**
318 * ubi_open_volume_path - open UBI volume by its character device node path.
319 * @pathname: volume character device node path
320 * @mode: open mode
321 *
322 * This function is similar to 'ubi_open_volume()', but opens a volume the path
323 * to its character device node.
324 */
325struct ubi_volume_desc *ubi_open_volume_path(const char *pathname, int mode)
326{
327 int error, ubi_num, vol_id;
328
329 dbg_gen("open volume %s, mode %d", pathname, mode);
330
331 if (!pathname || !*pathname)
332 return ERR_PTR(-EINVAL);
333
334 error = ubi_get_num_by_path(pathname, &ubi_num, &vol_id);
335 if (error)
336 return ERR_PTR(error);
337
338 return ubi_open_volume(ubi_num, vol_id, mode);
339}
340EXPORT_SYMBOL_GPL(ubi_open_volume_path);
341
342/**
343 * ubi_close_volume - close UBI volume.
344 * @desc: volume descriptor
345 */
346void ubi_close_volume(struct ubi_volume_desc *desc)
347{
348 struct ubi_volume *vol = desc->vol;
349 struct ubi_device *ubi = vol->ubi;
350
351 dbg_gen("close device %d, volume %d, mode %d",
352 ubi->ubi_num, vol->vol_id, desc->mode);
353
354 spin_lock(&ubi->volumes_lock);
355 switch (desc->mode) {
356 case UBI_READONLY:
357 vol->readers -= 1;
358 break;
359 case UBI_READWRITE:
360 vol->writers -= 1;
361 break;
362 case UBI_EXCLUSIVE:
363 vol->exclusive = 0;
364 break;
365 case UBI_METAONLY:
366 vol->metaonly = 0;
367 break;
368 }
369 vol->ref_count -= 1;
370 spin_unlock(&ubi->volumes_lock);
371
372 kfree(desc);
373 put_device(&vol->dev);
374 ubi_put_device(ubi);
375 module_put(THIS_MODULE);
376}
377EXPORT_SYMBOL_GPL(ubi_close_volume);
378
379/**
380 * leb_read_sanity_check - does sanity checks on read requests.
381 * @desc: volume descriptor
382 * @lnum: logical eraseblock number to read from
383 * @offset: offset within the logical eraseblock to read from
384 * @len: how many bytes to read
385 *
386 * This function is used by ubi_leb_read() and ubi_leb_read_sg()
387 * to perform sanity checks.
388 */
389static int leb_read_sanity_check(struct ubi_volume_desc *desc, int lnum,
390 int offset, int len)
391{
392 struct ubi_volume *vol = desc->vol;
393 struct ubi_device *ubi = vol->ubi;
394 int vol_id = vol->vol_id;
395
396 if (vol_id < 0 || vol_id >= ubi->vtbl_slots || lnum < 0 ||
397 lnum >= vol->used_ebs || offset < 0 || len < 0 ||
398 offset + len > vol->usable_leb_size)
399 return -EINVAL;
400
401 if (vol->vol_type == UBI_STATIC_VOLUME) {
402 if (vol->used_ebs == 0)
403 /* Empty static UBI volume */
404 return 0;
405 if (lnum == vol->used_ebs - 1 &&
406 offset + len > vol->last_eb_bytes)
407 return -EINVAL;
408 }
409
410 if (vol->upd_marker)
411 return -EBADF;
412
413 return 0;
414}
415
416/**
417 * ubi_leb_read - read data.
418 * @desc: volume descriptor
419 * @lnum: logical eraseblock number to read from
420 * @buf: buffer where to store the read data
421 * @offset: offset within the logical eraseblock to read from
422 * @len: how many bytes to read
423 * @check: whether UBI has to check the read data's CRC or not.
424 *
425 * This function reads data from offset @offset of logical eraseblock @lnum and
426 * stores the data at @buf. When reading from static volumes, @check specifies
427 * whether the data has to be checked or not. If yes, the whole logical
428 * eraseblock will be read and its CRC checksum will be checked (i.e., the CRC
429 * checksum is per-eraseblock). So checking may substantially slow down the
430 * read speed. The @check argument is ignored for dynamic volumes.
431 *
432 * In case of success, this function returns zero. In case of failure, this
433 * function returns a negative error code.
434 *
435 * %-EBADMSG error code is returned:
436 * o for both static and dynamic volumes if MTD driver has detected a data
437 * integrity problem (unrecoverable ECC checksum mismatch in case of NAND);
438 * o for static volumes in case of data CRC mismatch.
439 *
440 * If the volume is damaged because of an interrupted update this function just
441 * returns immediately with %-EBADF error code.
442 */
443int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
444 int len, int check)
445{
446 struct ubi_volume *vol = desc->vol;
447 struct ubi_device *ubi = vol->ubi;
448 int err, vol_id = vol->vol_id;
449
450 dbg_gen("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset);
451
452 err = leb_read_sanity_check(desc, lnum, offset, len);
453 if (err < 0)
454 return err;
455
456 if (len == 0)
457 return 0;
458
459 err = ubi_eba_read_leb(ubi, vol, lnum, buf, offset, len, check);
460 if (err && mtd_is_eccerr(err) && vol->vol_type == UBI_STATIC_VOLUME) {
461 ubi_warn(ubi, "mark volume %d as corrupted", vol_id);
462 vol->corrupted = 1;
463 }
464
465 return err;
466}
467EXPORT_SYMBOL_GPL(ubi_leb_read);
468
469
470/**
471 * ubi_leb_read_sg - read data into a scatter gather list.
472 * @desc: volume descriptor
473 * @lnum: logical eraseblock number to read from
474 * @sgl: UBI scatter gather list to store the read data
475 * @offset: offset within the logical eraseblock to read from
476 * @len: how many bytes to read
477 * @check: whether UBI has to check the read data's CRC or not.
478 *
479 * This function works exactly like ubi_leb_read_sg(). But instead of
480 * storing the read data into a buffer it writes to an UBI scatter gather
481 * list.
482 */
483int ubi_leb_read_sg(struct ubi_volume_desc *desc, int lnum, struct ubi_sgl *sgl,
484 int offset, int len, int check)
485{
486 struct ubi_volume *vol = desc->vol;
487 struct ubi_device *ubi = vol->ubi;
488 int err, vol_id = vol->vol_id;
489
490 dbg_gen("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset);
491
492 err = leb_read_sanity_check(desc, lnum, offset, len);
493 if (err < 0)
494 return err;
495
496 if (len == 0)
497 return 0;
498
499 err = ubi_eba_read_leb_sg(ubi, vol, sgl, lnum, offset, len, check);
500 if (err && mtd_is_eccerr(err) && vol->vol_type == UBI_STATIC_VOLUME) {
501 ubi_warn(ubi, "mark volume %d as corrupted", vol_id);
502 vol->corrupted = 1;
503 }
504
505 return err;
506}
507EXPORT_SYMBOL_GPL(ubi_leb_read_sg);
508
509/**
510 * ubi_leb_write - write data.
511 * @desc: volume descriptor
512 * @lnum: logical eraseblock number to write to
513 * @buf: data to write
514 * @offset: offset within the logical eraseblock where to write
515 * @len: how many bytes to write
516 *
517 * This function writes @len bytes of data from @buf to offset @offset of
518 * logical eraseblock @lnum.
519 *
520 * This function takes care of physical eraseblock write failures. If write to
521 * the physical eraseblock write operation fails, the logical eraseblock is
522 * re-mapped to another physical eraseblock, the data is recovered, and the
523 * write finishes. UBI has a pool of reserved physical eraseblocks for this.
524 *
525 * If all the data were successfully written, zero is returned. If an error
526 * occurred and UBI has not been able to recover from it, this function returns
527 * a negative error code. Note, in case of an error, it is possible that
528 * something was still written to the flash media, but that may be some
529 * garbage.
530 *
531 * If the volume is damaged because of an interrupted update this function just
532 * returns immediately with %-EBADF code.
533 */
534int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
535 int offset, int len)
536{
537 struct ubi_volume *vol = desc->vol;
538 struct ubi_device *ubi = vol->ubi;
539 int vol_id = vol->vol_id;
540
541 dbg_gen("write %d bytes to LEB %d:%d:%d", len, vol_id, lnum, offset);
542
543 if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
544 return -EINVAL;
545
546 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
547 return -EROFS;
548
549 if (!ubi_leb_valid(vol, lnum) || offset < 0 || len < 0 ||
550 offset + len > vol->usable_leb_size ||
551 offset & (ubi->min_io_size - 1) || len & (ubi->min_io_size - 1))
552 return -EINVAL;
553
554 if (vol->upd_marker)
555 return -EBADF;
556
557 if (len == 0)
558 return 0;
559
560 return ubi_eba_write_leb(ubi, vol, lnum, buf, offset, len);
561}
562EXPORT_SYMBOL_GPL(ubi_leb_write);
563
564/*
565 * ubi_leb_change - change logical eraseblock atomically.
566 * @desc: volume descriptor
567 * @lnum: logical eraseblock number to change
568 * @buf: data to write
569 * @len: how many bytes to write
570 *
571 * This function changes the contents of a logical eraseblock atomically. @buf
572 * has to contain new logical eraseblock data, and @len - the length of the
573 * data, which has to be aligned. The length may be shorter than the logical
574 * eraseblock size, ant the logical eraseblock may be appended to more times
575 * later on. This function guarantees that in case of an unclean reboot the old
576 * contents is preserved. Returns zero in case of success and a negative error
577 * code in case of failure.
578 */
579int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
580 int len)
581{
582 struct ubi_volume *vol = desc->vol;
583 struct ubi_device *ubi = vol->ubi;
584 int vol_id = vol->vol_id;
585
586 dbg_gen("atomically write %d bytes to LEB %d:%d", len, vol_id, lnum);
587
588 if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
589 return -EINVAL;
590
591 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
592 return -EROFS;
593
594 if (!ubi_leb_valid(vol, lnum) || len < 0 ||
595 len > vol->usable_leb_size || len & (ubi->min_io_size - 1))
596 return -EINVAL;
597
598 if (vol->upd_marker)
599 return -EBADF;
600
601 if (len == 0)
602 return 0;
603
604 return ubi_eba_atomic_leb_change(ubi, vol, lnum, buf, len);
605}
606EXPORT_SYMBOL_GPL(ubi_leb_change);
607
608/**
609 * ubi_leb_erase - erase logical eraseblock.
610 * @desc: volume descriptor
611 * @lnum: logical eraseblock number
612 *
613 * This function un-maps logical eraseblock @lnum and synchronously erases the
614 * correspondent physical eraseblock. Returns zero in case of success and a
615 * negative error code in case of failure.
616 *
617 * If the volume is damaged because of an interrupted update this function just
618 * returns immediately with %-EBADF code.
619 */
620int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum)
621{
622 struct ubi_volume *vol = desc->vol;
623 struct ubi_device *ubi = vol->ubi;
624 int err;
625
626 dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
627
628 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
629 return -EROFS;
630
631 if (!ubi_leb_valid(vol, lnum))
632 return -EINVAL;
633
634 if (vol->upd_marker)
635 return -EBADF;
636
637 err = ubi_eba_unmap_leb(ubi, vol, lnum);
638 if (err)
639 return err;
640
641 return ubi_wl_flush(ubi, vol->vol_id, lnum);
642}
643EXPORT_SYMBOL_GPL(ubi_leb_erase);
644
645/**
646 * ubi_leb_unmap - un-map logical eraseblock.
647 * @desc: volume descriptor
648 * @lnum: logical eraseblock number
649 *
650 * This function un-maps logical eraseblock @lnum and schedules the
651 * corresponding physical eraseblock for erasure, so that it will eventually be
652 * physically erased in background. This operation is much faster than the
653 * erase operation.
654 *
655 * Unlike erase, the un-map operation does not guarantee that the logical
656 * eraseblock will contain all 0xFF bytes when UBI is initialized again. For
657 * example, if several logical eraseblocks are un-mapped, and an unclean reboot
658 * happens after this, the logical eraseblocks will not necessarily be
659 * un-mapped again when this MTD device is attached. They may actually be
660 * mapped to the same physical eraseblocks again. So, this function has to be
661 * used with care.
662 *
663 * In other words, when un-mapping a logical eraseblock, UBI does not store
664 * any information about this on the flash media, it just marks the logical
665 * eraseblock as "un-mapped" in RAM. If UBI is detached before the physical
666 * eraseblock is physically erased, it will be mapped again to the same logical
667 * eraseblock when the MTD device is attached again.
668 *
669 * The main and obvious use-case of this function is when the contents of a
670 * logical eraseblock has to be re-written. Then it is much more efficient to
671 * first un-map it, then write new data, rather than first erase it, then write
672 * new data. Note, once new data has been written to the logical eraseblock,
673 * UBI guarantees that the old contents has gone forever. In other words, if an
674 * unclean reboot happens after the logical eraseblock has been un-mapped and
675 * then written to, it will contain the last written data.
676 *
677 * This function returns zero in case of success and a negative error code in
678 * case of failure. If the volume is damaged because of an interrupted update
679 * this function just returns immediately with %-EBADF code.
680 */
681int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum)
682{
683 struct ubi_volume *vol = desc->vol;
684 struct ubi_device *ubi = vol->ubi;
685
686 dbg_gen("unmap LEB %d:%d", vol->vol_id, lnum);
687
688 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
689 return -EROFS;
690
691 if (!ubi_leb_valid(vol, lnum))
692 return -EINVAL;
693
694 if (vol->upd_marker)
695 return -EBADF;
696
697 return ubi_eba_unmap_leb(ubi, vol, lnum);
698}
699EXPORT_SYMBOL_GPL(ubi_leb_unmap);
700
701/**
702 * ubi_leb_map - map logical eraseblock to a physical eraseblock.
703 * @desc: volume descriptor
704 * @lnum: logical eraseblock number
705 *
706 * This function maps an un-mapped logical eraseblock @lnum to a physical
707 * eraseblock. This means, that after a successful invocation of this
708 * function the logical eraseblock @lnum will be empty (contain only %0xFF
709 * bytes) and be mapped to a physical eraseblock, even if an unclean reboot
710 * happens.
711 *
712 * This function returns zero in case of success, %-EBADF if the volume is
713 * damaged because of an interrupted update, %-EBADMSG if the logical
714 * eraseblock is already mapped, and other negative error codes in case of
715 * other failures.
716 */
717int ubi_leb_map(struct ubi_volume_desc *desc, int lnum)
718{
719 struct ubi_volume *vol = desc->vol;
720 struct ubi_device *ubi = vol->ubi;
721
722 dbg_gen("map LEB %d:%d", vol->vol_id, lnum);
723
724 if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
725 return -EROFS;
726
727 if (!ubi_leb_valid(vol, lnum))
728 return -EINVAL;
729
730 if (vol->upd_marker)
731 return -EBADF;
732
733 if (ubi_eba_is_mapped(vol, lnum))
734 return -EBADMSG;
735
736 return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0);
737}
738EXPORT_SYMBOL_GPL(ubi_leb_map);
739
740/**
741 * ubi_is_mapped - check if logical eraseblock is mapped.
742 * @desc: volume descriptor
743 * @lnum: logical eraseblock number
744 *
745 * This function checks if logical eraseblock @lnum is mapped to a physical
746 * eraseblock. If a logical eraseblock is un-mapped, this does not necessarily
747 * mean it will still be un-mapped after the UBI device is re-attached. The
748 * logical eraseblock may become mapped to the physical eraseblock it was last
749 * mapped to.
750 *
751 * This function returns %1 if the LEB is mapped, %0 if not, and a negative
752 * error code in case of failure. If the volume is damaged because of an
753 * interrupted update this function just returns immediately with %-EBADF error
754 * code.
755 */
756int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum)
757{
758 struct ubi_volume *vol = desc->vol;
759
760 dbg_gen("test LEB %d:%d", vol->vol_id, lnum);
761
762 if (!ubi_leb_valid(vol, lnum))
763 return -EINVAL;
764
765 if (vol->upd_marker)
766 return -EBADF;
767
768 return ubi_eba_is_mapped(vol, lnum);
769}
770EXPORT_SYMBOL_GPL(ubi_is_mapped);
771
772/**
773 * ubi_sync - synchronize UBI device buffers.
774 * @ubi_num: UBI device to synchronize
775 *
776 * The underlying MTD device may cache data in hardware or in software. This
777 * function ensures the caches are flushed. Returns zero in case of success and
778 * a negative error code in case of failure.
779 */
780int ubi_sync(int ubi_num)
781{
782 struct ubi_device *ubi;
783
784 ubi = ubi_get_device(ubi_num);
785 if (!ubi)
786 return -ENODEV;
787
788 mtd_sync(ubi->mtd);
789 ubi_put_device(ubi);
790 return 0;
791}
792EXPORT_SYMBOL_GPL(ubi_sync);
793
794/**
795 * ubi_flush - flush UBI work queue.
796 * @ubi_num: UBI device to flush work queue
797 * @vol_id: volume id to flush for
798 * @lnum: logical eraseblock number to flush for
799 *
800 * This function executes all pending works for a particular volume id / logical
801 * eraseblock number pair. If either value is set to %UBI_ALL, then it acts as
802 * a wildcard for all of the corresponding volume numbers or logical
803 * eraseblock numbers. It returns zero in case of success and a negative error
804 * code in case of failure.
805 */
806int ubi_flush(int ubi_num, int vol_id, int lnum)
807{
808 struct ubi_device *ubi;
809 int err = 0;
810
811 ubi = ubi_get_device(ubi_num);
812 if (!ubi)
813 return -ENODEV;
814
815 err = ubi_wl_flush(ubi, vol_id, lnum);
816 ubi_put_device(ubi);
817 return err;
818}
819EXPORT_SYMBOL_GPL(ubi_flush);
820
821BLOCKING_NOTIFIER_HEAD(ubi_notifiers);
822
823/**
824 * ubi_register_volume_notifier - register a volume notifier.
825 * @nb: the notifier description object
826 * @ignore_existing: if non-zero, do not send "added" notification for all
827 * already existing volumes
828 *
829 * This function registers a volume notifier, which means that
830 * 'nb->notifier_call()' will be invoked when an UBI volume is created,
831 * removed, re-sized, re-named, or updated. The first argument of the function
832 * is the notification type. The second argument is pointer to a
833 * &struct ubi_notification object which describes the notification event.
834 * Using UBI API from the volume notifier is prohibited.
835 *
836 * This function returns zero in case of success and a negative error code
837 * in case of failure.
838 */
839int ubi_register_volume_notifier(struct notifier_block *nb,
840 int ignore_existing)
841{
842 int err;
843
844 err = blocking_notifier_chain_register(&ubi_notifiers, nb);
845 if (err != 0)
846 return err;
847 if (ignore_existing)
848 return 0;
849
850 /*
851 * We are going to walk all UBI devices and all volumes, and
852 * notify the user about existing volumes by the %UBI_VOLUME_ADDED
853 * event. We have to lock the @ubi_devices_mutex to make sure UBI
854 * devices do not disappear.
855 */
856 mutex_lock(&ubi_devices_mutex);
857 ubi_enumerate_volumes(nb);
858 mutex_unlock(&ubi_devices_mutex);
859
860 return err;
861}
862EXPORT_SYMBOL_GPL(ubi_register_volume_notifier);
863
864/**
865 * ubi_unregister_volume_notifier - unregister the volume notifier.
866 * @nb: the notifier description object
867 *
868 * This function unregisters volume notifier @nm and returns zero in case of
869 * success and a negative error code in case of failure.
870 */
871int ubi_unregister_volume_notifier(struct notifier_block *nb)
872{
873 return blocking_notifier_chain_unregister(&ubi_notifiers, nb);
874}
875EXPORT_SYMBOL_GPL(ubi_unregister_volume_notifier);