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Artem B. Bityutskiy801c1352006-06-27 12:22:22 +04001/*
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/*
Artem Bityutskiye6538792008-01-24 18:48:21 +020025 * This file contains implementation of the volume update and atomic LEB change
26 * functionality.
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +040027 *
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>
42#include <asm/uaccess.h>
43#include <asm/div64.h>
44#include "ubi.h"
45
46/**
47 * set_update_marker - set update marker.
48 * @ubi: UBI device description object
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +020049 * @vol: volume description object
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +040050 *
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +020051 * This function sets the update marker flag for volume @vol. Returns zero
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +040052 * in case of success and a negative error code in case of failure.
53 */
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +020054static int set_update_marker(struct ubi_device *ubi, struct ubi_volume *vol)
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +040055{
56 int err;
57 struct ubi_vtbl_record vtbl_rec;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +040058
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +020059 dbg_msg("set update marker for volume %d", vol->vol_id);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +040060
61 if (vol->upd_marker) {
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +020062 ubi_assert(ubi->vtbl[vol->vol_id].upd_marker);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +040063 dbg_msg("already set");
64 return 0;
65 }
66
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +020067 memcpy(&vtbl_rec, &ubi->vtbl[vol->vol_id],
68 sizeof(struct ubi_vtbl_record));
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +040069 vtbl_rec.upd_marker = 1;
70
Artem Bityutskiycae0a772007-12-17 12:46:48 +020071 mutex_lock(&ubi->volumes_mutex);
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +020072 err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec);
Artem Bityutskiycae0a772007-12-17 12:46:48 +020073 mutex_unlock(&ubi->volumes_mutex);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +040074 vol->upd_marker = 1;
75 return err;
76}
77
78/**
79 * clear_update_marker - clear update marker.
80 * @ubi: UBI device description object
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +020081 * @vol: volume description object
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +040082 * @bytes: new data size in bytes
83 *
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +020084 * This function clears the update marker for volume @vol, sets new volume
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +040085 * 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 */
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +020088static int clear_update_marker(struct ubi_device *ubi, struct ubi_volume *vol,
89 long long bytes)
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +040090{
91 int err;
92 uint64_t tmp;
93 struct ubi_vtbl_record vtbl_rec;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +040094
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +020095 dbg_msg("clear update marker for volume %d", vol->vol_id);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +040096
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +020097 memcpy(&vtbl_rec, &ubi->vtbl[vol->vol_id],
98 sizeof(struct ubi_vtbl_record));
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +040099 ubi_assert(vol->upd_marker && vtbl_rec.upd_marker);
100 vtbl_rec.upd_marker = 0;
101
102 if (vol->vol_type == UBI_STATIC_VOLUME) {
103 vol->corrupted = 0;
104 vol->used_bytes = tmp = bytes;
105 vol->last_eb_bytes = do_div(tmp, vol->usable_leb_size);
106 vol->used_ebs = tmp;
107 if (vol->last_eb_bytes)
108 vol->used_ebs += 1;
109 else
110 vol->last_eb_bytes = vol->usable_leb_size;
111 }
112
Artem Bityutskiycae0a772007-12-17 12:46:48 +0200113 mutex_lock(&ubi->volumes_mutex);
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +0200114 err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec);
Artem Bityutskiycae0a772007-12-17 12:46:48 +0200115 mutex_unlock(&ubi->volumes_mutex);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400116 vol->upd_marker = 0;
117 return err;
118}
119
120/**
121 * ubi_start_update - start volume update.
122 * @ubi: UBI device description object
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +0200123 * @vol: volume description object
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400124 * @bytes: update bytes
125 *
126 * This function starts volume update operation. If @bytes is zero, the volume
127 * is just wiped out. Returns zero in case of success and a negative error code
128 * in case of failure.
129 */
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +0200130int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
131 long long bytes)
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400132{
133 int i, err;
134 uint64_t tmp;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400135
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +0200136 dbg_msg("start update of volume %d, %llu bytes", vol->vol_id, bytes);
Artem Bityutskiye6538792008-01-24 18:48:21 +0200137 ubi_assert(!vol->updating && !vol->changing_leb);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400138 vol->updating = 1;
139
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +0200140 err = set_update_marker(ubi, vol);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400141 if (err)
142 return err;
143
144 /* Before updating - wipe out the volume */
145 for (i = 0; i < vol->reserved_pebs; i++) {
Artem Bityutskiy89b96b62007-12-16 20:00:38 +0200146 err = ubi_eba_unmap_leb(ubi, vol, i);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400147 if (err)
148 return err;
149 }
150
151 if (bytes == 0) {
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +0200152 err = clear_update_marker(ubi, vol, 0);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400153 if (err)
154 return err;
155 err = ubi_wl_flush(ubi);
156 if (!err)
157 vol->updating = 0;
158 }
159
Artem Bityutskiy92ad8f32007-05-06 16:12:54 +0300160 vol->upd_buf = vmalloc(ubi->leb_size);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400161 if (!vol->upd_buf)
162 return -ENOMEM;
163
164 tmp = bytes;
165 vol->upd_ebs = !!do_div(tmp, vol->usable_leb_size);
166 vol->upd_ebs += tmp;
167 vol->upd_bytes = bytes;
168 vol->upd_received = 0;
169 return 0;
170}
171
172/**
Artem Bityutskiye6538792008-01-24 18:48:21 +0200173 * ubi_start_leb_change - start atomic LEB change.
174 * @ubi: UBI device description object
175 * @vol: volume description object
176 * @req: operation request
177 *
178 * This function starts atomic LEB change operation. Returns zero in case of
179 * success and a negative error code in case of failure.
180 */
181int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
182 const struct ubi_leb_change_req *req)
183{
184 ubi_assert(!vol->updating && !vol->changing_leb);
185
186 dbg_msg("start changing LEB %d:%d, %u bytes",
187 vol->vol_id, req->lnum, req->bytes);
188 if (req->bytes == 0)
189 return ubi_eba_atomic_leb_change(ubi, vol, req->lnum, NULL, 0,
190 req->dtype);
191
192 vol->upd_bytes = req->bytes;
193 vol->upd_received = 0;
194 vol->changing_leb = 1;
195 vol->ch_lnum = req->lnum;
196 vol->ch_dtype = req->dtype;
197
198 vol->upd_buf = vmalloc(req->bytes);
199 if (!vol->upd_buf)
200 return -ENOMEM;
201
202 return 0;
203}
204
205/**
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400206 * write_leb - write update data.
207 * @ubi: UBI device description object
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +0200208 * @vol: volume description object
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400209 * @lnum: logical eraseblock number
210 * @buf: data to write
211 * @len: data size
212 * @used_ebs: how many logical eraseblocks will this volume contain (static
213 * volumes only)
214 *
215 * This function writes update data to corresponding logical eraseblock. In
216 * case of dynamic volume, this function checks if the data contains 0xFF bytes
217 * at the end. If yes, the 0xFF bytes are cut and not written. So if the whole
218 * buffer contains only 0xFF bytes, the LEB is left unmapped.
219 *
220 * The reason why we skip the trailing 0xFF bytes in case of dynamic volume is
221 * that we want to make sure that more data may be appended to the logical
222 * eraseblock in future. Indeed, writing 0xFF bytes may have side effects and
223 * this PEB won't be writable anymore. So if one writes the file-system image
224 * to the UBI volume where 0xFFs mean free space - UBI makes sure this free
225 * space is writable after the update.
226 *
227 * We do not do this for static volumes because they are read-only. But this
228 * also cannot be done because we have to store per-LEB CRC and the correct
229 * data length.
230 *
231 * This function returns zero in case of success and a negative error code in
232 * case of failure.
233 */
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +0200234static int write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
235 void *buf, int len, int used_ebs)
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400236{
Artem Bityutskiye6538792008-01-24 18:48:21 +0200237 int err;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400238
239 if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
Artem Bityutskiye6538792008-01-24 18:48:21 +0200240 len = ALIGN(len, ubi->min_io_size);
241 memset(buf + len, 0xFF, len - len);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400242
Artem Bityutskiye6538792008-01-24 18:48:21 +0200243 len = ubi_calc_data_len(ubi, buf, len);
244 if (len == 0) {
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400245 dbg_msg("all %d bytes contain 0xFF - skip", len);
246 return 0;
247 }
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400248
Artem Bityutskiye6538792008-01-24 18:48:21 +0200249 err = ubi_eba_write_leb(ubi, vol, lnum, buf, 0, len, UBI_UNKNOWN);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400250 } else {
251 /*
252 * When writing static volume, and this is the last logical
253 * eraseblock, the length (@len) does not have to be aligned to
254 * the minimal flash I/O unit. The 'ubi_eba_write_leb_st()'
255 * function accepts exact (unaligned) length and stores it in
256 * the VID header. And it takes care of proper alignment by
257 * padding the buffer. Here we just make sure the padding will
258 * contain zeros, not random trash.
259 */
260 memset(buf + len, 0, vol->usable_leb_size - len);
Artem Bityutskiy89b96b62007-12-16 20:00:38 +0200261 err = ubi_eba_write_leb_st(ubi, vol, lnum, buf, len,
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400262 UBI_UNKNOWN, used_ebs);
263 }
264
265 return err;
266}
267
268/**
269 * ubi_more_update_data - write more update data.
270 * @vol: volume description object
271 * @buf: write data (user-space memory buffer)
272 * @count: how much bytes to write
273 *
274 * This function writes more data to the volume which is being updated. It may
Artem Bityutskiye6538792008-01-24 18:48:21 +0200275 * be called arbitrary number of times until all the update data arriveis. This
276 * function returns %0 in case of success, number of bytes written during the
277 * last call if the whole volume update has been successfully finished, and a
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400278 * negative error code in case of failure.
279 */
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +0200280int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400281 const void __user *buf, int count)
282{
283 uint64_t tmp;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400284 int lnum, offs, err = 0, len, to_write = count;
285
286 dbg_msg("write %d of %lld bytes, %lld already passed",
287 count, vol->upd_bytes, vol->upd_received);
288
289 if (ubi->ro_mode)
290 return -EROFS;
291
292 tmp = vol->upd_received;
293 offs = do_div(tmp, vol->usable_leb_size);
294 lnum = tmp;
295
296 if (vol->upd_received + count > vol->upd_bytes)
297 to_write = count = vol->upd_bytes - vol->upd_received;
298
299 /*
300 * When updating volumes, we accumulate whole logical eraseblock of
301 * data and write it at once.
302 */
303 if (offs != 0) {
304 /*
305 * This is a write to the middle of the logical eraseblock. We
306 * copy the data to our update buffer and wait for more data or
307 * flush it if the whole eraseblock is written or the update
308 * is finished.
309 */
310
311 len = vol->usable_leb_size - offs;
312 if (len > count)
313 len = count;
314
315 err = copy_from_user(vol->upd_buf + offs, buf, len);
316 if (err)
317 return -EFAULT;
318
319 if (offs + len == vol->usable_leb_size ||
320 vol->upd_received + len == vol->upd_bytes) {
321 int flush_len = offs + len;
322
323 /*
324 * OK, we gathered either the whole eraseblock or this
325 * is the last chunk, it's time to flush the buffer.
326 */
327 ubi_assert(flush_len <= vol->usable_leb_size);
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +0200328 err = write_leb(ubi, vol, lnum, vol->upd_buf, flush_len,
329 vol->upd_ebs);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400330 if (err)
331 return err;
332 }
333
334 vol->upd_received += len;
335 count -= len;
336 buf += len;
337 lnum += 1;
338 }
339
340 /*
341 * If we've got more to write, let's continue. At this point we know we
342 * are starting from the beginning of an eraseblock.
343 */
344 while (count) {
345 if (count > vol->usable_leb_size)
346 len = vol->usable_leb_size;
347 else
348 len = count;
349
350 err = copy_from_user(vol->upd_buf, buf, len);
351 if (err)
352 return -EFAULT;
353
354 if (len == vol->usable_leb_size ||
355 vol->upd_received + len == vol->upd_bytes) {
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +0200356 err = write_leb(ubi, vol, lnum, vol->upd_buf,
357 len, vol->upd_ebs);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400358 if (err)
359 break;
360 }
361
362 vol->upd_received += len;
363 count -= len;
364 lnum += 1;
365 buf += len;
366 }
367
368 ubi_assert(vol->upd_received <= vol->upd_bytes);
369 if (vol->upd_received == vol->upd_bytes) {
370 /* The update is finished, clear the update marker */
Artem Bityutskiy1b68d0e2008-01-24 17:04:01 +0200371 err = clear_update_marker(ubi, vol, vol->upd_bytes);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400372 if (err)
373 return err;
374 err = ubi_wl_flush(ubi);
375 if (err == 0) {
Artem Bityutskiye6538792008-01-24 18:48:21 +0200376 vol->updating = 0;
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400377 err = to_write;
Artem Bityutskiy92ad8f32007-05-06 16:12:54 +0300378 vfree(vol->upd_buf);
Artem B. Bityutskiy801c1352006-06-27 12:22:22 +0400379 }
380 }
381
382 return err;
383}
Artem Bityutskiye6538792008-01-24 18:48:21 +0200384
385/**
386 * ubi_more_leb_change_data - accept more data for atomic LEB change.
387 * @vol: volume description object
388 * @buf: write data (user-space memory buffer)
389 * @count: how much bytes to write
390 *
391 * This function accepts more data to the volume which is being under the
392 * "atomic LEB change" operation. It may be called arbitrary number of times
393 * until all data arrives. This function returns %0 in case of success, number
394 * of bytes written during the last call if the whole "atomic LEB change"
395 * operation has been successfully finished, and a negative error code in case
396 * of failure.
397 */
398int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
399 const void __user *buf, int count)
400{
401 int err;
402
403 dbg_msg("write %d of %lld bytes, %lld already passed",
404 count, vol->upd_bytes, vol->upd_received);
405
406 if (ubi->ro_mode)
407 return -EROFS;
408
409 if (vol->upd_received + count > vol->upd_bytes)
410 count = vol->upd_bytes - vol->upd_received;
411
412 err = copy_from_user(vol->upd_buf + vol->upd_received, buf, count);
413 if (err)
414 return -EFAULT;
415
416 vol->upd_received += count;
417
418 if (vol->upd_received == vol->upd_bytes) {
419 int len = ALIGN((int)vol->upd_bytes, ubi->min_io_size);
420
421 memset(vol->upd_buf + vol->upd_bytes, 0xFF, len - vol->upd_bytes);
422 len = ubi_calc_data_len(ubi, vol->upd_buf, len);
423 err = ubi_eba_atomic_leb_change(ubi, vol, vol->ch_lnum,
424 vol->upd_buf, len, UBI_UNKNOWN);
425 if (err)
426 return err;
427 }
428
429 ubi_assert(vol->upd_received <= vol->upd_bytes);
430 if (vol->upd_received == vol->upd_bytes) {
431 vol->changing_leb = 0;
432 err = count;
433 vfree(vol->upd_buf);
434 }
435
436 return err;
437}