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 | */ |
26 | void 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 | } |
36 | EXPORT_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 | */ |
46 | int 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 | } |
59 | EXPORT_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 | */ |
67 | void 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 | */ |
90 | void ubi_get_volume_info(struct ubi_volume_desc *desc, |
91 | struct ubi_volume_info *vi) |
92 | { |
93 | ubi_do_get_volume_info(ubi: desc->vol->ubi, vol: desc->vol, vi); |
94 | } |
95 | EXPORT_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 | */ |
115 | struct 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(error: -EINVAL); |
126 | |
127 | if (mode != UBI_READONLY && mode != UBI_READWRITE && |
128 | mode != UBI_EXCLUSIVE && mode != UBI_METAONLY) |
129 | return ERR_PTR(error: -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(error: -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(size: 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(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(dev: &vol->dev); |
186 | vol->ref_count += 1; |
187 | spin_unlock(lock: &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(lock: &ubi->ckvol_mutex); |
198 | ubi_close_volume(desc); |
199 | return ERR_PTR(error: err); |
200 | } |
201 | if (err == 1) { |
202 | ubi_warn(ubi, fmt: "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(lock: &ubi->ckvol_mutex); |
209 | |
210 | return desc; |
211 | |
212 | out_unlock: |
213 | spin_unlock(lock: &ubi->volumes_lock); |
214 | module_put(THIS_MODULE); |
215 | out_free: |
216 | kfree(objp: desc); |
217 | out_put_ubi: |
218 | ubi_err(ubi, fmt: "cannot open device %d, volume %d, error %d" , |
219 | ubi_num, vol_id, err); |
220 | ubi_put_device(ubi); |
221 | return ERR_PTR(error: err); |
222 | } |
223 | EXPORT_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 | */ |
233 | struct 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(error: -EINVAL); |
244 | |
245 | len = strnlen(p: name, UBI_VOL_NAME_MAX + 1); |
246 | if (len > UBI_VOL_NAME_MAX) |
247 | return ERR_PTR(error: -EINVAL); |
248 | |
249 | if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES) |
250 | return ERR_PTR(error: -EINVAL); |
251 | |
252 | ubi = ubi_get_device(ubi_num); |
253 | if (!ubi) |
254 | return ERR_PTR(error: -ENODEV); |
255 | |
256 | spin_lock(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(lock: &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(error: -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 | } |
280 | EXPORT_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 | */ |
290 | int 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 | */ |
325 | struct 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(error: -EINVAL); |
333 | |
334 | error = ubi_get_num_by_path(pathname, ubi_num: &ubi_num, vol_id: &vol_id); |
335 | if (error) |
336 | return ERR_PTR(error); |
337 | |
338 | return ubi_open_volume(ubi_num, vol_id, mode); |
339 | } |
340 | EXPORT_SYMBOL_GPL(ubi_open_volume_path); |
341 | |
342 | /** |
343 | * ubi_close_volume - close UBI volume. |
344 | * @desc: volume descriptor |
345 | */ |
346 | void 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(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(lock: &ubi->volumes_lock); |
371 | |
372 | kfree(objp: desc); |
373 | put_device(dev: &vol->dev); |
374 | ubi_put_device(ubi); |
375 | module_put(THIS_MODULE); |
376 | } |
377 | EXPORT_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 | */ |
389 | static 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 | */ |
443 | int 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, fmt: "mark volume %d as corrupted" , vol_id); |
462 | vol->corrupted = 1; |
463 | } |
464 | |
465 | return err; |
466 | } |
467 | EXPORT_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 | */ |
483 | int 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, fmt: "mark volume %d as corrupted" , vol_id); |
502 | vol->corrupted = 1; |
503 | } |
504 | |
505 | return err; |
506 | } |
507 | EXPORT_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 | */ |
534 | int 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 | } |
562 | EXPORT_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 | */ |
579 | int 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 | } |
606 | EXPORT_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 | */ |
620 | int 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_id: vol->vol_id, lnum); |
642 | } |
643 | EXPORT_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 | */ |
681 | int 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 | } |
699 | EXPORT_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 | */ |
717 | int 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, offset: 0, len: 0); |
737 | } |
738 | EXPORT_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 | */ |
756 | int 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 | } |
770 | EXPORT_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 | */ |
780 | int 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(mtd: ubi->mtd); |
789 | ubi_put_device(ubi); |
790 | return 0; |
791 | } |
792 | EXPORT_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 | */ |
806 | int 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 | } |
819 | EXPORT_SYMBOL_GPL(ubi_flush); |
820 | |
821 | BLOCKING_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 | */ |
839 | int ubi_register_volume_notifier(struct notifier_block *nb, |
840 | int ignore_existing) |
841 | { |
842 | int err; |
843 | |
844 | err = blocking_notifier_chain_register(nh: &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(lock: &ubi_devices_mutex); |
859 | |
860 | return err; |
861 | } |
862 | EXPORT_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 | */ |
871 | int ubi_unregister_volume_notifier(struct notifier_block *nb) |
872 | { |
873 | return blocking_notifier_chain_unregister(nh: &ubi_notifiers, nb); |
874 | } |
875 | EXPORT_SYMBOL_GPL(ubi_unregister_volume_notifier); |
876 | |