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801c135c AB |
1 | /* |
2 | * Copyright (c) International Business Machines Corp., 2006 | |
3 | * Copyright (c) Nokia Corporation, 2006 | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License as published by | |
7 | * the Free Software Foundation; either version 2 of the License, or | |
8 | * (at your option) any later version. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See | |
13 | * the GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
18 | * | |
19 | * Author: Artem Bityutskiy (Битюцкий Артём) | |
20 | * | |
21 | * Jan 2007: Alexander Schmidt, hacked per-volume update. | |
22 | */ | |
23 | ||
24 | /* | |
e653879c AB |
25 | * This file contains implementation of the volume update and atomic LEB change |
26 | * functionality. | |
801c135c AB |
27 | * |
28 | * The update operation is based on the per-volume update marker which is | |
29 | * stored in the volume table. The update marker is set before the update | |
30 | * starts, and removed after the update has been finished. So if the update was | |
31 | * interrupted by an unclean re-boot or due to some other reasons, the update | |
32 | * marker stays on the flash media and UBI finds it when it attaches the MTD | |
33 | * device next time. If the update marker is set for a volume, the volume is | |
34 | * treated as damaged and most I/O operations are prohibited. Only a new update | |
35 | * operation is allowed. | |
36 | * | |
37 | * Note, in general it is possible to implement the update operation as a | |
38 | * transaction with a roll-back capability. | |
39 | */ | |
40 | ||
41 | #include <linux/err.h> | |
9c9ec147 | 42 | #include <linux/uaccess.h> |
3013ee31 | 43 | #include <linux/math64.h> |
801c135c AB |
44 | #include "ubi.h" |
45 | ||
46 | /** | |
47 | * set_update_marker - set update marker. | |
48 | * @ubi: UBI device description object | |
1b68d0ee | 49 | * @vol: volume description object |
801c135c | 50 | * |
1b68d0ee | 51 | * This function sets the update marker flag for volume @vol. Returns zero |
801c135c AB |
52 | * in case of success and a negative error code in case of failure. |
53 | */ | |
1b68d0ee | 54 | static int set_update_marker(struct ubi_device *ubi, struct ubi_volume *vol) |
801c135c AB |
55 | { |
56 | int err; | |
57 | struct ubi_vtbl_record vtbl_rec; | |
801c135c | 58 | |
c8566350 | 59 | dbg_gen("set update marker for volume %d", vol->vol_id); |
801c135c AB |
60 | |
61 | if (vol->upd_marker) { | |
1b68d0ee | 62 | ubi_assert(ubi->vtbl[vol->vol_id].upd_marker); |
c8566350 | 63 | dbg_gen("already set"); |
801c135c AB |
64 | return 0; |
65 | } | |
66 | ||
1b68d0ee AB |
67 | memcpy(&vtbl_rec, &ubi->vtbl[vol->vol_id], |
68 | sizeof(struct ubi_vtbl_record)); | |
801c135c AB |
69 | vtbl_rec.upd_marker = 1; |
70 | ||
cae0a771 | 71 | mutex_lock(&ubi->volumes_mutex); |
1b68d0ee | 72 | err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec); |
cae0a771 | 73 | mutex_unlock(&ubi->volumes_mutex); |
801c135c AB |
74 | vol->upd_marker = 1; |
75 | return err; | |
76 | } | |
77 | ||
78 | /** | |
79 | * clear_update_marker - clear update marker. | |
80 | * @ubi: UBI device description object | |
1b68d0ee | 81 | * @vol: volume description object |
801c135c AB |
82 | * @bytes: new data size in bytes |
83 | * | |
1b68d0ee | 84 | * This function clears the update marker for volume @vol, sets new volume |
801c135c AB |
85 | * data size and clears the "corrupted" flag (static volumes only). Returns |
86 | * zero in case of success and a negative error code in case of failure. | |
87 | */ | |
1b68d0ee AB |
88 | static int clear_update_marker(struct ubi_device *ubi, struct ubi_volume *vol, |
89 | long long bytes) | |
801c135c AB |
90 | { |
91 | int err; | |
801c135c | 92 | struct ubi_vtbl_record vtbl_rec; |
801c135c | 93 | |
c8566350 | 94 | dbg_gen("clear update marker for volume %d", vol->vol_id); |
801c135c | 95 | |
1b68d0ee AB |
96 | memcpy(&vtbl_rec, &ubi->vtbl[vol->vol_id], |
97 | sizeof(struct ubi_vtbl_record)); | |
801c135c AB |
98 | ubi_assert(vol->upd_marker && vtbl_rec.upd_marker); |
99 | vtbl_rec.upd_marker = 0; | |
100 | ||
101 | if (vol->vol_type == UBI_STATIC_VOLUME) { | |
102 | vol->corrupted = 0; | |
3013ee31 AB |
103 | vol->used_bytes = bytes; |
104 | vol->used_ebs = div_u64_rem(bytes, vol->usable_leb_size, | |
105 | &vol->last_eb_bytes); | |
801c135c AB |
106 | if (vol->last_eb_bytes) |
107 | vol->used_ebs += 1; | |
108 | else | |
109 | vol->last_eb_bytes = vol->usable_leb_size; | |
110 | } | |
111 | ||
cae0a771 | 112 | mutex_lock(&ubi->volumes_mutex); |
1b68d0ee | 113 | err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec); |
cae0a771 | 114 | mutex_unlock(&ubi->volumes_mutex); |
801c135c AB |
115 | vol->upd_marker = 0; |
116 | return err; | |
117 | } | |
118 | ||
119 | /** | |
120 | * ubi_start_update - start volume update. | |
121 | * @ubi: UBI device description object | |
1b68d0ee | 122 | * @vol: volume description object |
801c135c AB |
123 | * @bytes: update bytes |
124 | * | |
125 | * This function starts volume update operation. If @bytes is zero, the volume | |
126 | * is just wiped out. Returns zero in case of success and a negative error code | |
127 | * in case of failure. | |
128 | */ | |
1b68d0ee AB |
129 | int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol, |
130 | long long bytes) | |
801c135c AB |
131 | { |
132 | int i, err; | |
801c135c | 133 | |
c8566350 | 134 | dbg_gen("start update of volume %d, %llu bytes", vol->vol_id, bytes); |
e653879c | 135 | ubi_assert(!vol->updating && !vol->changing_leb); |
801c135c AB |
136 | vol->updating = 1; |
137 | ||
1b68d0ee | 138 | err = set_update_marker(ubi, vol); |
801c135c AB |
139 | if (err) |
140 | return err; | |
141 | ||
142 | /* Before updating - wipe out the volume */ | |
143 | for (i = 0; i < vol->reserved_pebs; i++) { | |
89b96b69 | 144 | err = ubi_eba_unmap_leb(ubi, vol, i); |
801c135c AB |
145 | if (err) |
146 | return err; | |
147 | } | |
148 | ||
149 | if (bytes == 0) { | |
1b68d0ee | 150 | err = clear_update_marker(ubi, vol, 0); |
801c135c AB |
151 | if (err) |
152 | return err; | |
153 | err = ubi_wl_flush(ubi); | |
154 | if (!err) | |
155 | vol->updating = 0; | |
156 | } | |
157 | ||
92ad8f37 | 158 | vol->upd_buf = vmalloc(ubi->leb_size); |
801c135c AB |
159 | if (!vol->upd_buf) |
160 | return -ENOMEM; | |
161 | ||
3013ee31 AB |
162 | vol->upd_ebs = div_u64(bytes + vol->usable_leb_size - 1, |
163 | vol->usable_leb_size); | |
801c135c AB |
164 | vol->upd_bytes = bytes; |
165 | vol->upd_received = 0; | |
166 | return 0; | |
167 | } | |
168 | ||
e653879c AB |
169 | /** |
170 | * ubi_start_leb_change - start atomic LEB change. | |
171 | * @ubi: UBI device description object | |
172 | * @vol: volume description object | |
173 | * @req: operation request | |
174 | * | |
175 | * This function starts atomic LEB change operation. Returns zero in case of | |
176 | * success and a negative error code in case of failure. | |
177 | */ | |
178 | int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol, | |
179 | const struct ubi_leb_change_req *req) | |
180 | { | |
181 | ubi_assert(!vol->updating && !vol->changing_leb); | |
182 | ||
c8566350 | 183 | dbg_gen("start changing LEB %d:%d, %u bytes", |
e653879c AB |
184 | vol->vol_id, req->lnum, req->bytes); |
185 | if (req->bytes == 0) | |
186 | return ubi_eba_atomic_leb_change(ubi, vol, req->lnum, NULL, 0, | |
187 | req->dtype); | |
188 | ||
189 | vol->upd_bytes = req->bytes; | |
190 | vol->upd_received = 0; | |
191 | vol->changing_leb = 1; | |
192 | vol->ch_lnum = req->lnum; | |
193 | vol->ch_dtype = req->dtype; | |
194 | ||
195 | vol->upd_buf = vmalloc(req->bytes); | |
196 | if (!vol->upd_buf) | |
197 | return -ENOMEM; | |
198 | ||
199 | return 0; | |
200 | } | |
201 | ||
801c135c AB |
202 | /** |
203 | * write_leb - write update data. | |
204 | * @ubi: UBI device description object | |
1b68d0ee | 205 | * @vol: volume description object |
801c135c AB |
206 | * @lnum: logical eraseblock number |
207 | * @buf: data to write | |
208 | * @len: data size | |
209 | * @used_ebs: how many logical eraseblocks will this volume contain (static | |
210 | * volumes only) | |
211 | * | |
212 | * This function writes update data to corresponding logical eraseblock. In | |
213 | * case of dynamic volume, this function checks if the data contains 0xFF bytes | |
214 | * at the end. If yes, the 0xFF bytes are cut and not written. So if the whole | |
215 | * buffer contains only 0xFF bytes, the LEB is left unmapped. | |
216 | * | |
217 | * The reason why we skip the trailing 0xFF bytes in case of dynamic volume is | |
218 | * that we want to make sure that more data may be appended to the logical | |
219 | * eraseblock in future. Indeed, writing 0xFF bytes may have side effects and | |
220 | * this PEB won't be writable anymore. So if one writes the file-system image | |
221 | * to the UBI volume where 0xFFs mean free space - UBI makes sure this free | |
222 | * space is writable after the update. | |
223 | * | |
224 | * We do not do this for static volumes because they are read-only. But this | |
225 | * also cannot be done because we have to store per-LEB CRC and the correct | |
226 | * data length. | |
227 | * | |
228 | * This function returns zero in case of success and a negative error code in | |
229 | * case of failure. | |
230 | */ | |
1b68d0ee AB |
231 | static int write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum, |
232 | void *buf, int len, int used_ebs) | |
801c135c | 233 | { |
e653879c | 234 | int err; |
801c135c AB |
235 | |
236 | if (vol->vol_type == UBI_DYNAMIC_VOLUME) { | |
a0fd1efd | 237 | int l = ALIGN(len, ubi->min_io_size); |
801c135c | 238 | |
a0fd1efd KP |
239 | memset(buf + len, 0xFF, l - len); |
240 | len = ubi_calc_data_len(ubi, buf, l); | |
e653879c | 241 | if (len == 0) { |
c8566350 | 242 | dbg_gen("all %d bytes contain 0xFF - skip", len); |
801c135c AB |
243 | return 0; |
244 | } | |
801c135c | 245 | |
9c9ec147 AB |
246 | err = ubi_eba_write_leb(ubi, vol, lnum, buf, 0, len, |
247 | UBI_UNKNOWN); | |
801c135c AB |
248 | } else { |
249 | /* | |
250 | * When writing static volume, and this is the last logical | |
251 | * eraseblock, the length (@len) does not have to be aligned to | |
252 | * the minimal flash I/O unit. The 'ubi_eba_write_leb_st()' | |
253 | * function accepts exact (unaligned) length and stores it in | |
254 | * the VID header. And it takes care of proper alignment by | |
255 | * padding the buffer. Here we just make sure the padding will | |
256 | * contain zeros, not random trash. | |
257 | */ | |
258 | memset(buf + len, 0, vol->usable_leb_size - len); | |
89b96b69 | 259 | err = ubi_eba_write_leb_st(ubi, vol, lnum, buf, len, |
801c135c AB |
260 | UBI_UNKNOWN, used_ebs); |
261 | } | |
262 | ||
263 | return err; | |
264 | } | |
265 | ||
266 | /** | |
267 | * ubi_more_update_data - write more update data. | |
ebaaf1af | 268 | * @ubi: UBI device description object |
801c135c AB |
269 | * @vol: volume description object |
270 | * @buf: write data (user-space memory buffer) | |
271 | * @count: how much bytes to write | |
272 | * | |
273 | * This function writes more data to the volume which is being updated. It may | |
e653879c AB |
274 | * be called arbitrary number of times until all the update data arriveis. This |
275 | * function returns %0 in case of success, number of bytes written during the | |
276 | * last call if the whole volume update has been successfully finished, and a | |
801c135c AB |
277 | * negative error code in case of failure. |
278 | */ | |
1b68d0ee | 279 | int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol, |
801c135c AB |
280 | const void __user *buf, int count) |
281 | { | |
801c135c AB |
282 | int lnum, offs, err = 0, len, to_write = count; |
283 | ||
c8566350 | 284 | dbg_gen("write %d of %lld bytes, %lld already passed", |
801c135c AB |
285 | count, vol->upd_bytes, vol->upd_received); |
286 | ||
287 | if (ubi->ro_mode) | |
288 | return -EROFS; | |
289 | ||
3013ee31 | 290 | lnum = div_u64_rem(vol->upd_received, vol->usable_leb_size, &offs); |
801c135c AB |
291 | if (vol->upd_received + count > vol->upd_bytes) |
292 | to_write = count = vol->upd_bytes - vol->upd_received; | |
293 | ||
294 | /* | |
295 | * When updating volumes, we accumulate whole logical eraseblock of | |
296 | * data and write it at once. | |
297 | */ | |
298 | if (offs != 0) { | |
299 | /* | |
300 | * This is a write to the middle of the logical eraseblock. We | |
301 | * copy the data to our update buffer and wait for more data or | |
302 | * flush it if the whole eraseblock is written or the update | |
303 | * is finished. | |
304 | */ | |
305 | ||
306 | len = vol->usable_leb_size - offs; | |
307 | if (len > count) | |
308 | len = count; | |
309 | ||
310 | err = copy_from_user(vol->upd_buf + offs, buf, len); | |
311 | if (err) | |
312 | return -EFAULT; | |
313 | ||
314 | if (offs + len == vol->usable_leb_size || | |
315 | vol->upd_received + len == vol->upd_bytes) { | |
316 | int flush_len = offs + len; | |
317 | ||
318 | /* | |
319 | * OK, we gathered either the whole eraseblock or this | |
320 | * is the last chunk, it's time to flush the buffer. | |
321 | */ | |
322 | ubi_assert(flush_len <= vol->usable_leb_size); | |
1b68d0ee AB |
323 | err = write_leb(ubi, vol, lnum, vol->upd_buf, flush_len, |
324 | vol->upd_ebs); | |
801c135c AB |
325 | if (err) |
326 | return err; | |
327 | } | |
328 | ||
329 | vol->upd_received += len; | |
330 | count -= len; | |
331 | buf += len; | |
332 | lnum += 1; | |
333 | } | |
334 | ||
335 | /* | |
336 | * If we've got more to write, let's continue. At this point we know we | |
337 | * are starting from the beginning of an eraseblock. | |
338 | */ | |
339 | while (count) { | |
340 | if (count > vol->usable_leb_size) | |
341 | len = vol->usable_leb_size; | |
342 | else | |
343 | len = count; | |
344 | ||
345 | err = copy_from_user(vol->upd_buf, buf, len); | |
346 | if (err) | |
347 | return -EFAULT; | |
348 | ||
349 | if (len == vol->usable_leb_size || | |
350 | vol->upd_received + len == vol->upd_bytes) { | |
1b68d0ee AB |
351 | err = write_leb(ubi, vol, lnum, vol->upd_buf, |
352 | len, vol->upd_ebs); | |
801c135c AB |
353 | if (err) |
354 | break; | |
355 | } | |
356 | ||
357 | vol->upd_received += len; | |
358 | count -= len; | |
359 | lnum += 1; | |
360 | buf += len; | |
361 | } | |
362 | ||
363 | ubi_assert(vol->upd_received <= vol->upd_bytes); | |
364 | if (vol->upd_received == vol->upd_bytes) { | |
365 | /* The update is finished, clear the update marker */ | |
1b68d0ee | 366 | err = clear_update_marker(ubi, vol, vol->upd_bytes); |
801c135c AB |
367 | if (err) |
368 | return err; | |
369 | err = ubi_wl_flush(ubi); | |
370 | if (err == 0) { | |
e653879c | 371 | vol->updating = 0; |
801c135c | 372 | err = to_write; |
92ad8f37 | 373 | vfree(vol->upd_buf); |
801c135c AB |
374 | } |
375 | } | |
376 | ||
377 | return err; | |
378 | } | |
e653879c AB |
379 | |
380 | /** | |
381 | * ubi_more_leb_change_data - accept more data for atomic LEB change. | |
ebaaf1af | 382 | * @ubi: UBI device description object |
e653879c AB |
383 | * @vol: volume description object |
384 | * @buf: write data (user-space memory buffer) | |
385 | * @count: how much bytes to write | |
386 | * | |
387 | * This function accepts more data to the volume which is being under the | |
388 | * "atomic LEB change" operation. It may be called arbitrary number of times | |
389 | * until all data arrives. This function returns %0 in case of success, number | |
390 | * of bytes written during the last call if the whole "atomic LEB change" | |
391 | * operation has been successfully finished, and a negative error code in case | |
392 | * of failure. | |
393 | */ | |
394 | int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol, | |
395 | const void __user *buf, int count) | |
396 | { | |
397 | int err; | |
398 | ||
c8566350 | 399 | dbg_gen("write %d of %lld bytes, %lld already passed", |
e653879c AB |
400 | count, vol->upd_bytes, vol->upd_received); |
401 | ||
402 | if (ubi->ro_mode) | |
403 | return -EROFS; | |
404 | ||
405 | if (vol->upd_received + count > vol->upd_bytes) | |
406 | count = vol->upd_bytes - vol->upd_received; | |
407 | ||
408 | err = copy_from_user(vol->upd_buf + vol->upd_received, buf, count); | |
409 | if (err) | |
410 | return -EFAULT; | |
411 | ||
412 | vol->upd_received += count; | |
413 | ||
414 | if (vol->upd_received == vol->upd_bytes) { | |
415 | int len = ALIGN((int)vol->upd_bytes, ubi->min_io_size); | |
416 | ||
9c9ec147 AB |
417 | memset(vol->upd_buf + vol->upd_bytes, 0xFF, |
418 | len - vol->upd_bytes); | |
e653879c AB |
419 | len = ubi_calc_data_len(ubi, vol->upd_buf, len); |
420 | err = ubi_eba_atomic_leb_change(ubi, vol, vol->ch_lnum, | |
421 | vol->upd_buf, len, UBI_UNKNOWN); | |
422 | if (err) | |
423 | return err; | |
424 | } | |
425 | ||
426 | ubi_assert(vol->upd_received <= vol->upd_bytes); | |
427 | if (vol->upd_received == vol->upd_bytes) { | |
428 | vol->changing_leb = 0; | |
429 | err = count; | |
430 | vfree(vol->upd_buf); | |
431 | } | |
432 | ||
433 | return err; | |
434 | } |