]>
Commit | Line | Data |
---|---|---|
801c135c AB |
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 <asm/div64.h> | |
26 | #include "ubi.h" | |
27 | ||
28 | /** | |
29 | * ubi_get_device_info - get information about UBI device. | |
30 | * @ubi_num: UBI device number | |
31 | * @di: the information is stored here | |
32 | * | |
33 | * This function returns %0 in case of success and a %-ENODEV if there is no | |
34 | * such UBI device. | |
35 | */ | |
36 | int ubi_get_device_info(int ubi_num, struct ubi_device_info *di) | |
37 | { | |
38 | const struct ubi_device *ubi; | |
39 | ||
801c135c | 40 | if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES || |
503990eb | 41 | !ubi_devices[ubi_num]) |
801c135c | 42 | return -ENODEV; |
801c135c AB |
43 | |
44 | ubi = ubi_devices[ubi_num]; | |
45 | di->ubi_num = ubi->ubi_num; | |
46 | di->leb_size = ubi->leb_size; | |
47 | di->min_io_size = ubi->min_io_size; | |
48 | di->ro_mode = ubi->ro_mode; | |
49 | di->cdev = MKDEV(ubi->major, 0); | |
801c135c AB |
50 | return 0; |
51 | } | |
52 | EXPORT_SYMBOL_GPL(ubi_get_device_info); | |
53 | ||
54 | /** | |
55 | * ubi_get_volume_info - get information about UBI volume. | |
56 | * @desc: volume descriptor | |
57 | * @vi: the information is stored here | |
58 | */ | |
59 | void ubi_get_volume_info(struct ubi_volume_desc *desc, | |
60 | struct ubi_volume_info *vi) | |
61 | { | |
62 | const struct ubi_volume *vol = desc->vol; | |
63 | const struct ubi_device *ubi = vol->ubi; | |
64 | ||
65 | vi->vol_id = vol->vol_id; | |
66 | vi->ubi_num = ubi->ubi_num; | |
67 | vi->size = vol->reserved_pebs; | |
68 | vi->used_bytes = vol->used_bytes; | |
69 | vi->vol_type = vol->vol_type; | |
70 | vi->corrupted = vol->corrupted; | |
71 | vi->upd_marker = vol->upd_marker; | |
72 | vi->alignment = vol->alignment; | |
73 | vi->usable_leb_size = vol->usable_leb_size; | |
74 | vi->name_len = vol->name_len; | |
75 | vi->name = vol->name; | |
76 | vi->cdev = MKDEV(ubi->major, vi->vol_id + 1); | |
77 | } | |
78 | EXPORT_SYMBOL_GPL(ubi_get_volume_info); | |
79 | ||
80 | /** | |
81 | * ubi_open_volume - open UBI volume. | |
82 | * @ubi_num: UBI device number | |
83 | * @vol_id: volume ID | |
84 | * @mode: open mode | |
85 | * | |
86 | * The @mode parameter specifies if the volume should be opened in read-only | |
87 | * mode, read-write mode, or exclusive mode. The exclusive mode guarantees that | |
88 | * nobody else will be able to open this volume. UBI allows to have many volume | |
89 | * readers and one writer at a time. | |
90 | * | |
91 | * If a static volume is being opened for the first time since boot, it will be | |
92 | * checked by this function, which means it will be fully read and the CRC | |
93 | * checksum of each logical eraseblock will be checked. | |
94 | * | |
95 | * This function returns volume descriptor in case of success and a negative | |
96 | * error code in case of failure. | |
97 | */ | |
98 | struct ubi_volume_desc *ubi_open_volume(int ubi_num, int vol_id, int mode) | |
99 | { | |
100 | int err; | |
101 | struct ubi_volume_desc *desc; | |
102 | struct ubi_device *ubi = ubi_devices[ubi_num]; | |
103 | struct ubi_volume *vol; | |
104 | ||
105 | dbg_msg("open device %d volume %d, mode %d", ubi_num, vol_id, mode); | |
106 | ||
107 | err = -ENODEV; | |
108 | if (!try_module_get(THIS_MODULE)) | |
109 | return ERR_PTR(err); | |
110 | ||
111 | if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES || !ubi) | |
112 | goto out_put; | |
113 | ||
114 | err = -EINVAL; | |
115 | if (vol_id < 0 || vol_id >= ubi->vtbl_slots) | |
116 | goto out_put; | |
117 | if (mode != UBI_READONLY && mode != UBI_READWRITE && | |
118 | mode != UBI_EXCLUSIVE) | |
119 | goto out_put; | |
120 | ||
121 | desc = kmalloc(sizeof(struct ubi_volume_desc), GFP_KERNEL); | |
122 | if (!desc) { | |
123 | err = -ENOMEM; | |
124 | goto out_put; | |
125 | } | |
126 | ||
127 | spin_lock(&ubi->volumes_lock); | |
128 | vol = ubi->volumes[vol_id]; | |
129 | if (!vol) { | |
130 | err = -ENODEV; | |
131 | goto out_unlock; | |
132 | } | |
133 | ||
134 | err = -EBUSY; | |
135 | switch (mode) { | |
136 | case UBI_READONLY: | |
137 | if (vol->exclusive) | |
138 | goto out_unlock; | |
139 | vol->readers += 1; | |
140 | break; | |
141 | ||
142 | case UBI_READWRITE: | |
143 | if (vol->exclusive || vol->writers > 0) | |
144 | goto out_unlock; | |
145 | vol->writers += 1; | |
146 | break; | |
147 | ||
148 | case UBI_EXCLUSIVE: | |
149 | if (vol->exclusive || vol->writers || vol->readers) | |
150 | goto out_unlock; | |
151 | vol->exclusive = 1; | |
152 | break; | |
153 | } | |
154 | spin_unlock(&ubi->volumes_lock); | |
155 | ||
156 | desc->vol = vol; | |
157 | desc->mode = mode; | |
158 | ||
159 | /* | |
160 | * To prevent simultaneous checks of the same volume we use @vtbl_mutex, | |
161 | * although it is not the purpose it was introduced for. | |
162 | */ | |
163 | mutex_lock(&ubi->vtbl_mutex); | |
164 | if (!vol->checked) { | |
165 | /* This is the first open - check the volume */ | |
166 | err = ubi_check_volume(ubi, vol_id); | |
167 | if (err < 0) { | |
168 | mutex_unlock(&ubi->vtbl_mutex); | |
169 | ubi_close_volume(desc); | |
170 | return ERR_PTR(err); | |
171 | } | |
172 | if (err == 1) { | |
173 | ubi_warn("volume %d on UBI device %d is corrupted", | |
174 | vol_id, ubi->ubi_num); | |
175 | vol->corrupted = 1; | |
176 | } | |
177 | vol->checked = 1; | |
178 | } | |
179 | mutex_unlock(&ubi->vtbl_mutex); | |
180 | return desc; | |
181 | ||
182 | out_unlock: | |
183 | spin_unlock(&ubi->volumes_lock); | |
184 | kfree(desc); | |
185 | out_put: | |
186 | module_put(THIS_MODULE); | |
187 | return ERR_PTR(err); | |
188 | } | |
189 | EXPORT_SYMBOL_GPL(ubi_open_volume); | |
190 | ||
191 | /** | |
192 | * ubi_open_volume_nm - open UBI volume by name. | |
193 | * @ubi_num: UBI device number | |
194 | * @name: volume name | |
195 | * @mode: open mode | |
196 | * | |
197 | * This function is similar to 'ubi_open_volume()', but opens a volume by name. | |
198 | */ | |
199 | struct ubi_volume_desc *ubi_open_volume_nm(int ubi_num, const char *name, | |
200 | int mode) | |
201 | { | |
202 | int i, vol_id = -1, len; | |
203 | struct ubi_volume_desc *ret; | |
204 | struct ubi_device *ubi; | |
205 | ||
206 | dbg_msg("open volume %s, mode %d", name, mode); | |
207 | ||
208 | if (!name) | |
209 | return ERR_PTR(-EINVAL); | |
210 | ||
211 | len = strnlen(name, UBI_VOL_NAME_MAX + 1); | |
212 | if (len > UBI_VOL_NAME_MAX) | |
213 | return ERR_PTR(-EINVAL); | |
214 | ||
215 | ret = ERR_PTR(-ENODEV); | |
216 | if (!try_module_get(THIS_MODULE)) | |
217 | return ret; | |
218 | ||
219 | if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES || !ubi_devices[ubi_num]) | |
220 | goto out_put; | |
221 | ||
222 | ubi = ubi_devices[ubi_num]; | |
223 | ||
224 | spin_lock(&ubi->volumes_lock); | |
225 | /* Walk all volumes of this UBI device */ | |
226 | for (i = 0; i < ubi->vtbl_slots; i++) { | |
227 | struct ubi_volume *vol = ubi->volumes[i]; | |
228 | ||
229 | if (vol && len == vol->name_len && !strcmp(name, vol->name)) { | |
230 | vol_id = i; | |
231 | break; | |
232 | } | |
233 | } | |
234 | spin_unlock(&ubi->volumes_lock); | |
235 | ||
236 | if (vol_id < 0) | |
237 | goto out_put; | |
238 | ||
239 | ret = ubi_open_volume(ubi_num, vol_id, mode); | |
240 | ||
241 | out_put: | |
242 | module_put(THIS_MODULE); | |
243 | return ret; | |
244 | } | |
245 | EXPORT_SYMBOL_GPL(ubi_open_volume_nm); | |
246 | ||
247 | /** | |
248 | * ubi_close_volume - close UBI volume. | |
249 | * @desc: volume descriptor | |
250 | */ | |
251 | void ubi_close_volume(struct ubi_volume_desc *desc) | |
252 | { | |
253 | struct ubi_volume *vol = desc->vol; | |
254 | ||
255 | dbg_msg("close volume %d, mode %d", vol->vol_id, desc->mode); | |
256 | ||
257 | spin_lock(&vol->ubi->volumes_lock); | |
258 | switch (desc->mode) { | |
259 | case UBI_READONLY: | |
260 | vol->readers -= 1; | |
261 | break; | |
262 | case UBI_READWRITE: | |
263 | vol->writers -= 1; | |
264 | break; | |
265 | case UBI_EXCLUSIVE: | |
266 | vol->exclusive = 0; | |
267 | } | |
268 | spin_unlock(&vol->ubi->volumes_lock); | |
269 | ||
270 | kfree(desc); | |
271 | module_put(THIS_MODULE); | |
272 | } | |
273 | EXPORT_SYMBOL_GPL(ubi_close_volume); | |
274 | ||
275 | /** | |
276 | * ubi_leb_read - read data. | |
277 | * @desc: volume descriptor | |
278 | * @lnum: logical eraseblock number to read from | |
279 | * @buf: buffer where to store the read data | |
280 | * @offset: offset within the logical eraseblock to read from | |
281 | * @len: how many bytes to read | |
282 | * @check: whether UBI has to check the read data's CRC or not. | |
283 | * | |
284 | * This function reads data from offset @offset of logical eraseblock @lnum and | |
285 | * stores the data at @buf. When reading from static volumes, @check specifies | |
286 | * whether the data has to be checked or not. If yes, the whole logical | |
287 | * eraseblock will be read and its CRC checksum will be checked (i.e., the CRC | |
288 | * checksum is per-eraseblock). So checking may substantially slow down the | |
289 | * read speed. The @check argument is ignored for dynamic volumes. | |
290 | * | |
291 | * In case of success, this function returns zero. In case of failure, this | |
292 | * function returns a negative error code. | |
293 | * | |
294 | * %-EBADMSG error code is returned: | |
295 | * o for both static and dynamic volumes if MTD driver has detected a data | |
296 | * integrity problem (unrecoverable ECC checksum mismatch in case of NAND); | |
297 | * o for static volumes in case of data CRC mismatch. | |
298 | * | |
299 | * If the volume is damaged because of an interrupted update this function just | |
300 | * returns immediately with %-EBADF error code. | |
301 | */ | |
302 | int ubi_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset, | |
303 | int len, int check) | |
304 | { | |
305 | struct ubi_volume *vol = desc->vol; | |
306 | struct ubi_device *ubi = vol->ubi; | |
307 | int err, vol_id = vol->vol_id; | |
308 | ||
309 | dbg_msg("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset); | |
310 | ||
311 | if (vol_id < 0 || vol_id >= ubi->vtbl_slots || lnum < 0 || | |
312 | lnum >= vol->used_ebs || offset < 0 || len < 0 || | |
313 | offset + len > vol->usable_leb_size) | |
314 | return -EINVAL; | |
315 | ||
4ab60a0d AB |
316 | if (vol->vol_type == UBI_STATIC_VOLUME) { |
317 | if (vol->used_ebs == 0) | |
318 | /* Empty static UBI volume */ | |
319 | return 0; | |
320 | if (lnum == vol->used_ebs - 1 && | |
321 | offset + len > vol->last_eb_bytes) | |
322 | return -EINVAL; | |
323 | } | |
801c135c AB |
324 | |
325 | if (vol->upd_marker) | |
326 | return -EBADF; | |
327 | if (len == 0) | |
328 | return 0; | |
329 | ||
330 | err = ubi_eba_read_leb(ubi, vol_id, lnum, buf, offset, len, check); | |
331 | if (err && err == -EBADMSG && vol->vol_type == UBI_STATIC_VOLUME) { | |
332 | ubi_warn("mark volume %d as corrupted", vol_id); | |
333 | vol->corrupted = 1; | |
334 | } | |
335 | ||
336 | return err; | |
337 | } | |
338 | EXPORT_SYMBOL_GPL(ubi_leb_read); | |
339 | ||
340 | /** | |
341 | * ubi_leb_write - write data. | |
342 | * @desc: volume descriptor | |
343 | * @lnum: logical eraseblock number to write to | |
344 | * @buf: data to write | |
345 | * @offset: offset within the logical eraseblock where to write | |
346 | * @len: how many bytes to write | |
347 | * @dtype: expected data type | |
348 | * | |
349 | * This function writes @len bytes of data from @buf to offset @offset of | |
350 | * logical eraseblock @lnum. The @dtype argument describes expected lifetime of | |
351 | * the data. | |
352 | * | |
353 | * This function takes care of physical eraseblock write failures. If write to | |
354 | * the physical eraseblock write operation fails, the logical eraseblock is | |
355 | * re-mapped to another physical eraseblock, the data is recovered, and the | |
356 | * write finishes. UBI has a pool of reserved physical eraseblocks for this. | |
357 | * | |
358 | * If all the data were successfully written, zero is returned. If an error | |
359 | * occurred and UBI has not been able to recover from it, this function returns | |
360 | * a negative error code. Note, in case of an error, it is possible that | |
361 | * something was still written to the flash media, but that may be some | |
362 | * garbage. | |
363 | * | |
364 | * If the volume is damaged because of an interrupted update this function just | |
365 | * returns immediately with %-EBADF code. | |
366 | */ | |
367 | int ubi_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf, | |
368 | int offset, int len, int dtype) | |
369 | { | |
370 | struct ubi_volume *vol = desc->vol; | |
371 | struct ubi_device *ubi = vol->ubi; | |
372 | int vol_id = vol->vol_id; | |
373 | ||
374 | dbg_msg("write %d bytes to LEB %d:%d:%d", len, vol_id, lnum, offset); | |
375 | ||
376 | if (vol_id < 0 || vol_id >= ubi->vtbl_slots) | |
377 | return -EINVAL; | |
378 | ||
379 | if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME) | |
380 | return -EROFS; | |
381 | ||
382 | if (lnum < 0 || lnum >= vol->reserved_pebs || offset < 0 || len < 0 || | |
383 | offset + len > vol->usable_leb_size || offset % ubi->min_io_size || | |
384 | len % ubi->min_io_size) | |
385 | return -EINVAL; | |
386 | ||
387 | if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM && | |
388 | dtype != UBI_UNKNOWN) | |
389 | return -EINVAL; | |
390 | ||
391 | if (vol->upd_marker) | |
392 | return -EBADF; | |
393 | ||
394 | if (len == 0) | |
395 | return 0; | |
396 | ||
397 | return ubi_eba_write_leb(ubi, vol_id, lnum, buf, offset, len, dtype); | |
398 | } | |
399 | EXPORT_SYMBOL_GPL(ubi_leb_write); | |
400 | ||
401 | /* | |
402 | * ubi_leb_change - change logical eraseblock atomically. | |
403 | * @desc: volume descriptor | |
404 | * @lnum: logical eraseblock number to change | |
405 | * @buf: data to write | |
406 | * @len: how many bytes to write | |
407 | * @dtype: expected data type | |
408 | * | |
409 | * This function changes the contents of a logical eraseblock atomically. @buf | |
410 | * has to contain new logical eraseblock data, and @len - the length of the | |
411 | * data, which has to be aligned. The length may be shorter then the logical | |
412 | * eraseblock size, ant the logical eraseblock may be appended to more times | |
413 | * later on. This function guarantees that in case of an unclean reboot the old | |
414 | * contents is preserved. Returns zero in case of success and a negative error | |
415 | * code in case of failure. | |
416 | */ | |
417 | int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf, | |
418 | int len, int dtype) | |
419 | { | |
420 | struct ubi_volume *vol = desc->vol; | |
421 | struct ubi_device *ubi = vol->ubi; | |
422 | int vol_id = vol->vol_id; | |
423 | ||
424 | dbg_msg("atomically write %d bytes to LEB %d:%d", len, vol_id, lnum); | |
425 | ||
426 | if (vol_id < 0 || vol_id >= ubi->vtbl_slots) | |
427 | return -EINVAL; | |
428 | ||
429 | if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME) | |
430 | return -EROFS; | |
431 | ||
432 | if (lnum < 0 || lnum >= vol->reserved_pebs || len < 0 || | |
433 | len > vol->usable_leb_size || len % ubi->min_io_size) | |
434 | return -EINVAL; | |
435 | ||
436 | if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM && | |
437 | dtype != UBI_UNKNOWN) | |
438 | return -EINVAL; | |
439 | ||
440 | if (vol->upd_marker) | |
441 | return -EBADF; | |
442 | ||
443 | if (len == 0) | |
444 | return 0; | |
445 | ||
446 | return ubi_eba_atomic_leb_change(ubi, vol_id, lnum, buf, len, dtype); | |
447 | } | |
448 | EXPORT_SYMBOL_GPL(ubi_leb_change); | |
449 | ||
450 | /** | |
451 | * ubi_leb_erase - erase logical eraseblock. | |
452 | * @desc: volume descriptor | |
453 | * @lnum: logical eraseblock number | |
454 | * | |
455 | * This function un-maps logical eraseblock @lnum and synchronously erases the | |
456 | * correspondent physical eraseblock. Returns zero in case of success and a | |
457 | * negative error code in case of failure. | |
458 | * | |
459 | * If the volume is damaged because of an interrupted update this function just | |
460 | * returns immediately with %-EBADF code. | |
461 | */ | |
462 | int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum) | |
463 | { | |
464 | struct ubi_volume *vol = desc->vol; | |
465 | struct ubi_device *ubi = vol->ubi; | |
466 | int err, vol_id = vol->vol_id; | |
467 | ||
468 | dbg_msg("erase LEB %d:%d", vol_id, lnum); | |
469 | ||
470 | if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME) | |
471 | return -EROFS; | |
472 | ||
473 | if (lnum < 0 || lnum >= vol->reserved_pebs) | |
474 | return -EINVAL; | |
475 | ||
476 | if (vol->upd_marker) | |
477 | return -EBADF; | |
478 | ||
479 | err = ubi_eba_unmap_leb(ubi, vol_id, lnum); | |
480 | if (err) | |
481 | return err; | |
482 | ||
483 | return ubi_wl_flush(ubi); | |
484 | } | |
485 | EXPORT_SYMBOL_GPL(ubi_leb_erase); | |
486 | ||
487 | /** | |
488 | * ubi_leb_unmap - un-map logical eraseblock. | |
489 | * @desc: volume descriptor | |
490 | * @lnum: logical eraseblock number | |
491 | * | |
492 | * This function un-maps logical eraseblock @lnum and schedules the | |
493 | * corresponding physical eraseblock for erasure, so that it will eventually be | |
494 | * physically erased in background. This operation is much faster then the | |
495 | * erase operation. | |
496 | * | |
497 | * Unlike erase, the un-map operation does not guarantee that the logical | |
498 | * eraseblock will contain all 0xFF bytes when UBI is initialized again. For | |
499 | * example, if several logical eraseblocks are un-mapped, and an unclean reboot | |
500 | * happens after this, the logical eraseblocks will not necessarily be | |
501 | * un-mapped again when this MTD device is attached. They may actually be | |
502 | * mapped to the same physical eraseblocks again. So, this function has to be | |
503 | * used with care. | |
504 | * | |
505 | * In other words, when un-mapping a logical eraseblock, UBI does not store | |
506 | * any information about this on the flash media, it just marks the logical | |
507 | * eraseblock as "un-mapped" in RAM. If UBI is detached before the physical | |
508 | * eraseblock is physically erased, it will be mapped again to the same logical | |
509 | * eraseblock when the MTD device is attached again. | |
510 | * | |
511 | * The main and obvious use-case of this function is when the contents of a | |
512 | * logical eraseblock has to be re-written. Then it is much more efficient to | |
513 | * first un-map it, then write new data, rather then first erase it, then write | |
514 | * new data. Note, once new data has been written to the logical eraseblock, | |
515 | * UBI guarantees that the old contents has gone forever. In other words, if an | |
516 | * unclean reboot happens after the logical eraseblock has been un-mapped and | |
517 | * then written to, it will contain the last written data. | |
518 | * | |
519 | * This function returns zero in case of success and a negative error code in | |
520 | * case of failure. If the volume is damaged because of an interrupted update | |
521 | * this function just returns immediately with %-EBADF code. | |
522 | */ | |
523 | int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum) | |
524 | { | |
525 | struct ubi_volume *vol = desc->vol; | |
526 | struct ubi_device *ubi = vol->ubi; | |
527 | int vol_id = vol->vol_id; | |
528 | ||
529 | dbg_msg("unmap LEB %d:%d", vol_id, lnum); | |
530 | ||
531 | if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME) | |
532 | return -EROFS; | |
533 | ||
534 | if (lnum < 0 || lnum >= vol->reserved_pebs) | |
535 | return -EINVAL; | |
536 | ||
537 | if (vol->upd_marker) | |
538 | return -EBADF; | |
539 | ||
540 | return ubi_eba_unmap_leb(ubi, vol_id, lnum); | |
541 | } | |
542 | EXPORT_SYMBOL_GPL(ubi_leb_unmap); | |
543 | ||
544 | /** | |
545 | * ubi_is_mapped - check if logical eraseblock is mapped. | |
546 | * @desc: volume descriptor | |
547 | * @lnum: logical eraseblock number | |
548 | * | |
549 | * This function checks if logical eraseblock @lnum is mapped to a physical | |
550 | * eraseblock. If a logical eraseblock is un-mapped, this does not necessarily | |
551 | * mean it will still be un-mapped after the UBI device is re-attached. The | |
552 | * logical eraseblock may become mapped to the physical eraseblock it was last | |
553 | * mapped to. | |
554 | * | |
555 | * This function returns %1 if the LEB is mapped, %0 if not, and a negative | |
556 | * error code in case of failure. If the volume is damaged because of an | |
557 | * interrupted update this function just returns immediately with %-EBADF error | |
558 | * code. | |
559 | */ | |
560 | int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum) | |
561 | { | |
562 | struct ubi_volume *vol = desc->vol; | |
563 | ||
564 | dbg_msg("test LEB %d:%d", vol->vol_id, lnum); | |
565 | ||
566 | if (lnum < 0 || lnum >= vol->reserved_pebs) | |
567 | return -EINVAL; | |
568 | ||
569 | if (vol->upd_marker) | |
570 | return -EBADF; | |
571 | ||
572 | return vol->eba_tbl[lnum] >= 0; | |
573 | } | |
574 | EXPORT_SYMBOL_GPL(ubi_is_mapped); |