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 */
ubi_do_get_device_info(struct ubi_device * ubi,struct ubi_device_info * di)39 void 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 }
49 EXPORT_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 */
ubi_get_device_info(int ubi_num,struct ubi_device_info * di)59 int 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 }
72 EXPORT_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 */
ubi_do_get_volume_info(struct ubi_device * ubi,struct ubi_volume * vol,struct ubi_volume_info * vi)80 void 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 */
ubi_get_volume_info(struct ubi_volume_desc * desc,struct ubi_volume_info * vi)102 void 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 }
107 EXPORT_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 */
ubi_open_volume(int ubi_num,int vol_id,int mode)127 struct 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
217 out_unlock:
218 spin_unlock(&ubi->volumes_lock);
219 module_put(THIS_MODULE);
220 out_free:
221 kfree(desc);
222 out_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 }
228 EXPORT_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 */
ubi_open_volume_nm(int ubi_num,const char * name,int mode)238 struct 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 }
285 EXPORT_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 */
ubi_open_volume_path(const char * pathname,int mode)295 struct 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 }
322 EXPORT_SYMBOL_GPL(ubi_open_volume_path);
323
324 /**
325 * ubi_close_volume - close UBI volume.
326 * @desc: volume descriptor
327 */
ubi_close_volume(struct ubi_volume_desc * desc)328 void 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 }
355 EXPORT_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 */
ubi_leb_read(struct ubi_volume_desc * desc,int lnum,char * buf,int offset,int len,int check)384 int 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 && mtd_is_eccerr(err) && 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 }
420 EXPORT_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 */
ubi_leb_write(struct ubi_volume_desc * desc,int lnum,const void * buf,int offset,int len,int dtype)449 int 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 }
481 EXPORT_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 */
ubi_leb_change(struct ubi_volume_desc * desc,int lnum,const void * buf,int len,int dtype)499 int 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 }
530 EXPORT_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 */
ubi_leb_erase(struct ubi_volume_desc * desc,int lnum)544 int 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 }
567 EXPORT_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 */
ubi_leb_unmap(struct ubi_volume_desc * desc,int lnum)605 int 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 }
623 EXPORT_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 */
ubi_leb_map(struct ubi_volume_desc * desc,int lnum,int dtype)642 int 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 }
667 EXPORT_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 */
ubi_is_mapped(struct ubi_volume_desc * desc,int lnum)685 int 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 }
699 EXPORT_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 */
ubi_sync(int ubi_num)709 int 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 mtd_sync(ubi->mtd);
718 ubi_put_device(ubi);
719 return 0;
720 }
721 EXPORT_SYMBOL_GPL(ubi_sync);
722
723 BLOCKING_NOTIFIER_HEAD(ubi_notifiers);
724
725 /**
726 * ubi_register_volume_notifier - register a volume notifier.
727 * @nb: the notifier description object
728 * @ignore_existing: if non-zero, do not send "added" notification for all
729 * already existing volumes
730 *
731 * This function registers a volume notifier, which means that
732 * 'nb->notifier_call()' will be invoked when an UBI volume is created,
733 * removed, re-sized, re-named, or updated. The first argument of the function
734 * is the notification type. The second argument is pointer to a
735 * &struct ubi_notification object which describes the notification event.
736 * Using UBI API from the volume notifier is prohibited.
737 *
738 * This function returns zero in case of success and a negative error code
739 * in case of failure.
740 */
ubi_register_volume_notifier(struct notifier_block * nb,int ignore_existing)741 int ubi_register_volume_notifier(struct notifier_block *nb,
742 int ignore_existing)
743 {
744 int err;
745
746 err = blocking_notifier_chain_register(&ubi_notifiers, nb);
747 if (err != 0)
748 return err;
749 if (ignore_existing)
750 return 0;
751
752 /*
753 * We are going to walk all UBI devices and all volumes, and
754 * notify the user about existing volumes by the %UBI_VOLUME_ADDED
755 * event. We have to lock the @ubi_devices_mutex to make sure UBI
756 * devices do not disappear.
757 */
758 mutex_lock(&ubi_devices_mutex);
759 ubi_enumerate_volumes(nb);
760 mutex_unlock(&ubi_devices_mutex);
761
762 return err;
763 }
764 EXPORT_SYMBOL_GPL(ubi_register_volume_notifier);
765
766 /**
767 * ubi_unregister_volume_notifier - unregister the volume notifier.
768 * @nb: the notifier description object
769 *
770 * This function unregisters volume notifier @nm and returns zero in case of
771 * success and a negative error code in case of failure.
772 */
ubi_unregister_volume_notifier(struct notifier_block * nb)773 int ubi_unregister_volume_notifier(struct notifier_block *nb)
774 {
775 return blocking_notifier_chain_unregister(&ubi_notifiers, nb);
776 }
777 EXPORT_SYMBOL_GPL(ubi_unregister_volume_notifier);
778