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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 | ||
d856c13c | 67 | vtbl_rec = ubi->vtbl[vol->vol_id]; |
801c135c AB |
68 | vtbl_rec.upd_marker = 1; |
69 | ||
f089c0b2 | 70 | mutex_lock(&ubi->device_mutex); |
1b68d0ee | 71 | err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec); |
801c135c | 72 | vol->upd_marker = 1; |
95c9c1da | 73 | mutex_unlock(&ubi->device_mutex); |
801c135c AB |
74 | return err; |
75 | } | |
76 | ||
77 | /** | |
78 | * clear_update_marker - clear update marker. | |
79 | * @ubi: UBI device description object | |
1b68d0ee | 80 | * @vol: volume description object |
801c135c AB |
81 | * @bytes: new data size in bytes |
82 | * | |
1b68d0ee | 83 | * This function clears the update marker for volume @vol, sets new volume |
801c135c AB |
84 | * data size and clears the "corrupted" flag (static volumes only). Returns |
85 | * zero in case of success and a negative error code in case of failure. | |
86 | */ | |
1b68d0ee AB |
87 | static int clear_update_marker(struct ubi_device *ubi, struct ubi_volume *vol, |
88 | long long bytes) | |
801c135c AB |
89 | { |
90 | int err; | |
801c135c | 91 | struct ubi_vtbl_record vtbl_rec; |
801c135c | 92 | |
c8566350 | 93 | dbg_gen("clear update marker for volume %d", vol->vol_id); |
801c135c | 94 | |
d856c13c | 95 | vtbl_rec = ubi->vtbl[vol->vol_id]; |
801c135c AB |
96 | ubi_assert(vol->upd_marker && vtbl_rec.upd_marker); |
97 | vtbl_rec.upd_marker = 0; | |
98 | ||
99 | if (vol->vol_type == UBI_STATIC_VOLUME) { | |
100 | vol->corrupted = 0; | |
3013ee31 AB |
101 | vol->used_bytes = bytes; |
102 | vol->used_ebs = div_u64_rem(bytes, vol->usable_leb_size, | |
103 | &vol->last_eb_bytes); | |
801c135c AB |
104 | if (vol->last_eb_bytes) |
105 | vol->used_ebs += 1; | |
106 | else | |
107 | vol->last_eb_bytes = vol->usable_leb_size; | |
108 | } | |
109 | ||
f089c0b2 | 110 | mutex_lock(&ubi->device_mutex); |
1b68d0ee | 111 | err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec); |
801c135c | 112 | vol->upd_marker = 0; |
95c9c1da | 113 | mutex_unlock(&ubi->device_mutex); |
801c135c AB |
114 | return err; |
115 | } | |
116 | ||
117 | /** | |
118 | * ubi_start_update - start volume update. | |
119 | * @ubi: UBI device description object | |
1b68d0ee | 120 | * @vol: volume description object |
801c135c AB |
121 | * @bytes: update bytes |
122 | * | |
123 | * This function starts volume update operation. If @bytes is zero, the volume | |
124 | * is just wiped out. Returns zero in case of success and a negative error code | |
125 | * in case of failure. | |
126 | */ | |
1b68d0ee AB |
127 | int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol, |
128 | long long bytes) | |
801c135c AB |
129 | { |
130 | int i, err; | |
801c135c | 131 | |
c8566350 | 132 | dbg_gen("start update of volume %d, %llu bytes", vol->vol_id, bytes); |
e653879c | 133 | ubi_assert(!vol->updating && !vol->changing_leb); |
801c135c AB |
134 | vol->updating = 1; |
135 | ||
1b68d0ee | 136 | err = set_update_marker(ubi, vol); |
801c135c AB |
137 | if (err) |
138 | return err; | |
139 | ||
140 | /* Before updating - wipe out the volume */ | |
141 | for (i = 0; i < vol->reserved_pebs; i++) { | |
89b96b69 | 142 | err = ubi_eba_unmap_leb(ubi, vol, i); |
801c135c AB |
143 | if (err) |
144 | return err; | |
145 | } | |
146 | ||
147 | if (bytes == 0) { | |
62f38455 | 148 | err = ubi_wl_flush(ubi, UBI_ALL, UBI_ALL); |
6afaf8a4 SAS |
149 | if (err) |
150 | return err; | |
151 | ||
1b68d0ee | 152 | err = clear_update_marker(ubi, vol, 0); |
801c135c AB |
153 | if (err) |
154 | return err; | |
6afaf8a4 | 155 | vol->updating = 0; |
ebddd63b | 156 | return 0; |
801c135c AB |
157 | } |
158 | ||
92ad8f37 | 159 | vol->upd_buf = vmalloc(ubi->leb_size); |
801c135c AB |
160 | if (!vol->upd_buf) |
161 | return -ENOMEM; | |
162 | ||
3013ee31 AB |
163 | vol->upd_ebs = div_u64(bytes + vol->usable_leb_size - 1, |
164 | vol->usable_leb_size); | |
801c135c AB |
165 | vol->upd_bytes = bytes; |
166 | vol->upd_received = 0; | |
167 | return 0; | |
168 | } | |
169 | ||
e653879c AB |
170 | /** |
171 | * ubi_start_leb_change - start atomic LEB change. | |
172 | * @ubi: UBI device description object | |
173 | * @vol: volume description object | |
174 | * @req: operation request | |
175 | * | |
176 | * This function starts atomic LEB change operation. Returns zero in case of | |
177 | * success and a negative error code in case of failure. | |
178 | */ | |
179 | int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol, | |
180 | const struct ubi_leb_change_req *req) | |
181 | { | |
182 | ubi_assert(!vol->updating && !vol->changing_leb); | |
183 | ||
c8566350 | 184 | dbg_gen("start changing LEB %d:%d, %u bytes", |
e653879c AB |
185 | vol->vol_id, req->lnum, req->bytes); |
186 | if (req->bytes == 0) | |
b36a261e | 187 | return ubi_eba_atomic_leb_change(ubi, vol, req->lnum, NULL, 0); |
e653879c AB |
188 | |
189 | vol->upd_bytes = req->bytes; | |
190 | vol->upd_received = 0; | |
191 | vol->changing_leb = 1; | |
192 | vol->ch_lnum = req->lnum; | |
e653879c AB |
193 | |
194 | vol->upd_buf = vmalloc(req->bytes); | |
195 | if (!vol->upd_buf) | |
196 | return -ENOMEM; | |
197 | ||
198 | return 0; | |
199 | } | |
200 | ||
801c135c AB |
201 | /** |
202 | * write_leb - write update data. | |
203 | * @ubi: UBI device description object | |
1b68d0ee | 204 | * @vol: volume description object |
801c135c AB |
205 | * @lnum: logical eraseblock number |
206 | * @buf: data to write | |
207 | * @len: data size | |
208 | * @used_ebs: how many logical eraseblocks will this volume contain (static | |
209 | * volumes only) | |
210 | * | |
211 | * This function writes update data to corresponding logical eraseblock. In | |
212 | * case of dynamic volume, this function checks if the data contains 0xFF bytes | |
213 | * at the end. If yes, the 0xFF bytes are cut and not written. So if the whole | |
214 | * buffer contains only 0xFF bytes, the LEB is left unmapped. | |
215 | * | |
216 | * The reason why we skip the trailing 0xFF bytes in case of dynamic volume is | |
217 | * that we want to make sure that more data may be appended to the logical | |
218 | * eraseblock in future. Indeed, writing 0xFF bytes may have side effects and | |
219 | * this PEB won't be writable anymore. So if one writes the file-system image | |
220 | * to the UBI volume where 0xFFs mean free space - UBI makes sure this free | |
221 | * space is writable after the update. | |
222 | * | |
223 | * We do not do this for static volumes because they are read-only. But this | |
224 | * also cannot be done because we have to store per-LEB CRC and the correct | |
225 | * data length. | |
226 | * | |
227 | * This function returns zero in case of success and a negative error code in | |
228 | * case of failure. | |
229 | */ | |
1b68d0ee AB |
230 | static int write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum, |
231 | void *buf, int len, int used_ebs) | |
801c135c | 232 | { |
e653879c | 233 | int err; |
801c135c AB |
234 | |
235 | if (vol->vol_type == UBI_DYNAMIC_VOLUME) { | |
a0fd1efd | 236 | int l = ALIGN(len, ubi->min_io_size); |
801c135c | 237 | |
a0fd1efd KP |
238 | memset(buf + len, 0xFF, l - len); |
239 | len = ubi_calc_data_len(ubi, buf, l); | |
e653879c | 240 | if (len == 0) { |
c8566350 | 241 | dbg_gen("all %d bytes contain 0xFF - skip", len); |
801c135c AB |
242 | return 0; |
243 | } | |
801c135c | 244 | |
b36a261e | 245 | err = ubi_eba_write_leb(ubi, vol, lnum, buf, 0, len); |
801c135c AB |
246 | } else { |
247 | /* | |
248 | * When writing static volume, and this is the last logical | |
249 | * eraseblock, the length (@len) does not have to be aligned to | |
250 | * the minimal flash I/O unit. The 'ubi_eba_write_leb_st()' | |
251 | * function accepts exact (unaligned) length and stores it in | |
252 | * the VID header. And it takes care of proper alignment by | |
253 | * padding the buffer. Here we just make sure the padding will | |
254 | * contain zeros, not random trash. | |
255 | */ | |
256 | memset(buf + len, 0, vol->usable_leb_size - len); | |
b36a261e | 257 | err = ubi_eba_write_leb_st(ubi, vol, lnum, buf, len, used_ebs); |
801c135c AB |
258 | } |
259 | ||
260 | return err; | |
261 | } | |
262 | ||
263 | /** | |
264 | * ubi_more_update_data - write more update data. | |
ebaaf1af | 265 | * @ubi: UBI device description object |
801c135c AB |
266 | * @vol: volume description object |
267 | * @buf: write data (user-space memory buffer) | |
268 | * @count: how much bytes to write | |
269 | * | |
270 | * This function writes more data to the volume which is being updated. It may | |
e653879c AB |
271 | * be called arbitrary number of times until all the update data arriveis. This |
272 | * function returns %0 in case of success, number of bytes written during the | |
273 | * last call if the whole volume update has been successfully finished, and a | |
801c135c AB |
274 | * negative error code in case of failure. |
275 | */ | |
1b68d0ee | 276 | int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol, |
801c135c AB |
277 | const void __user *buf, int count) |
278 | { | |
801c135c AB |
279 | int lnum, offs, err = 0, len, to_write = count; |
280 | ||
c8566350 | 281 | dbg_gen("write %d of %lld bytes, %lld already passed", |
801c135c AB |
282 | count, vol->upd_bytes, vol->upd_received); |
283 | ||
284 | if (ubi->ro_mode) | |
285 | return -EROFS; | |
286 | ||
3013ee31 | 287 | lnum = div_u64_rem(vol->upd_received, vol->usable_leb_size, &offs); |
801c135c AB |
288 | if (vol->upd_received + count > vol->upd_bytes) |
289 | to_write = count = vol->upd_bytes - vol->upd_received; | |
290 | ||
291 | /* | |
292 | * When updating volumes, we accumulate whole logical eraseblock of | |
293 | * data and write it at once. | |
294 | */ | |
295 | if (offs != 0) { | |
296 | /* | |
297 | * This is a write to the middle of the logical eraseblock. We | |
298 | * copy the data to our update buffer and wait for more data or | |
299 | * flush it if the whole eraseblock is written or the update | |
300 | * is finished. | |
301 | */ | |
302 | ||
303 | len = vol->usable_leb_size - offs; | |
304 | if (len > count) | |
305 | len = count; | |
306 | ||
307 | err = copy_from_user(vol->upd_buf + offs, buf, len); | |
308 | if (err) | |
309 | return -EFAULT; | |
310 | ||
311 | if (offs + len == vol->usable_leb_size || | |
312 | vol->upd_received + len == vol->upd_bytes) { | |
313 | int flush_len = offs + len; | |
314 | ||
315 | /* | |
316 | * OK, we gathered either the whole eraseblock or this | |
317 | * is the last chunk, it's time to flush the buffer. | |
318 | */ | |
319 | ubi_assert(flush_len <= vol->usable_leb_size); | |
1b68d0ee AB |
320 | err = write_leb(ubi, vol, lnum, vol->upd_buf, flush_len, |
321 | vol->upd_ebs); | |
801c135c AB |
322 | if (err) |
323 | return err; | |
324 | } | |
325 | ||
326 | vol->upd_received += len; | |
327 | count -= len; | |
328 | buf += len; | |
329 | lnum += 1; | |
330 | } | |
331 | ||
332 | /* | |
333 | * If we've got more to write, let's continue. At this point we know we | |
334 | * are starting from the beginning of an eraseblock. | |
335 | */ | |
336 | while (count) { | |
337 | if (count > vol->usable_leb_size) | |
338 | len = vol->usable_leb_size; | |
339 | else | |
340 | len = count; | |
341 | ||
342 | err = copy_from_user(vol->upd_buf, buf, len); | |
343 | if (err) | |
344 | return -EFAULT; | |
345 | ||
346 | if (len == vol->usable_leb_size || | |
347 | vol->upd_received + len == vol->upd_bytes) { | |
1b68d0ee AB |
348 | err = write_leb(ubi, vol, lnum, vol->upd_buf, |
349 | len, vol->upd_ebs); | |
801c135c AB |
350 | if (err) |
351 | break; | |
352 | } | |
353 | ||
354 | vol->upd_received += len; | |
355 | count -= len; | |
356 | lnum += 1; | |
357 | buf += len; | |
358 | } | |
359 | ||
360 | ubi_assert(vol->upd_received <= vol->upd_bytes); | |
361 | if (vol->upd_received == vol->upd_bytes) { | |
62f38455 | 362 | err = ubi_wl_flush(ubi, UBI_ALL, UBI_ALL); |
6afaf8a4 SAS |
363 | if (err) |
364 | return err; | |
801c135c | 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; | |
6afaf8a4 SAS |
369 | vol->updating = 0; |
370 | err = to_write; | |
371 | vfree(vol->upd_buf); | |
801c135c AB |
372 | } |
373 | ||
374 | return err; | |
375 | } | |
e653879c AB |
376 | |
377 | /** | |
378 | * ubi_more_leb_change_data - accept more data for atomic LEB change. | |
ebaaf1af | 379 | * @ubi: UBI device description object |
e653879c AB |
380 | * @vol: volume description object |
381 | * @buf: write data (user-space memory buffer) | |
382 | * @count: how much bytes to write | |
383 | * | |
384 | * This function accepts more data to the volume which is being under the | |
385 | * "atomic LEB change" operation. It may be called arbitrary number of times | |
386 | * until all data arrives. This function returns %0 in case of success, number | |
387 | * of bytes written during the last call if the whole "atomic LEB change" | |
388 | * operation has been successfully finished, and a negative error code in case | |
389 | * of failure. | |
390 | */ | |
391 | int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol, | |
392 | const void __user *buf, int count) | |
393 | { | |
394 | int err; | |
395 | ||
c8566350 | 396 | dbg_gen("write %d of %lld bytes, %lld already passed", |
e653879c AB |
397 | count, vol->upd_bytes, vol->upd_received); |
398 | ||
399 | if (ubi->ro_mode) | |
400 | return -EROFS; | |
401 | ||
402 | if (vol->upd_received + count > vol->upd_bytes) | |
403 | count = vol->upd_bytes - vol->upd_received; | |
404 | ||
405 | err = copy_from_user(vol->upd_buf + vol->upd_received, buf, count); | |
406 | if (err) | |
407 | return -EFAULT; | |
408 | ||
409 | vol->upd_received += count; | |
410 | ||
411 | if (vol->upd_received == vol->upd_bytes) { | |
412 | int len = ALIGN((int)vol->upd_bytes, ubi->min_io_size); | |
413 | ||
9c9ec147 AB |
414 | memset(vol->upd_buf + vol->upd_bytes, 0xFF, |
415 | len - vol->upd_bytes); | |
e653879c AB |
416 | len = ubi_calc_data_len(ubi, vol->upd_buf, len); |
417 | err = ubi_eba_atomic_leb_change(ubi, vol, vol->ch_lnum, | |
b36a261e | 418 | vol->upd_buf, len); |
e653879c AB |
419 | if (err) |
420 | return err; | |
421 | } | |
422 | ||
423 | ubi_assert(vol->upd_received <= vol->upd_bytes); | |
424 | if (vol->upd_received == vol->upd_bytes) { | |
425 | vol->changing_leb = 0; | |
426 | err = count; | |
427 | vfree(vol->upd_buf); | |
428 | } | |
429 | ||
430 | return err; | |
431 | } |