2 * Copyright (c) International Business Machines Corp., 2006
3 * Copyright (c) Nokia Corporation, 2006
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.
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.
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
19 * Author: Artem Bityutskiy (Битюцкий Артём)
21 * Jan 2007: Alexander Schmidt, hacked per-volume update.
25 * This file contains implementation of the volume update and atomic LEB change
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.
37 * Note, in general it is possible to implement the update operation as a
38 * transaction with a roll-back capability.
41 #include <linux/err.h>
42 #include <linux/uaccess.h>
43 #include <linux/math64.h>
47 * set_update_marker - set update marker.
48 * @ubi: UBI device description object
49 * @vol: volume description object
51 * This function sets the update marker flag for volume @vol. Returns zero
52 * in case of success and a negative error code in case of failure.
54 static int set_update_marker(struct ubi_device *ubi, struct ubi_volume *vol)
57 struct ubi_vtbl_record vtbl_rec;
59 dbg_gen("set update marker for volume %d", vol->vol_id);
61 if (vol->upd_marker) {
62 ubi_assert(ubi->vtbl[vol->vol_id].upd_marker);
63 dbg_gen("already set");
67 vtbl_rec = ubi->vtbl[vol->vol_id];
68 vtbl_rec.upd_marker = 1;
70 mutex_lock(&ubi->device_mutex);
71 err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec);
73 mutex_unlock(&ubi->device_mutex);
78 * clear_update_marker - clear update marker.
79 * @ubi: UBI device description object
80 * @vol: volume description object
81 * @bytes: new data size in bytes
83 * This function clears the update marker for volume @vol, sets new volume
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.
87 static int clear_update_marker(struct ubi_device *ubi, struct ubi_volume *vol,
91 struct ubi_vtbl_record vtbl_rec;
93 dbg_gen("clear update marker for volume %d", vol->vol_id);
95 vtbl_rec = ubi->vtbl[vol->vol_id];
96 ubi_assert(vol->upd_marker && vtbl_rec.upd_marker);
97 vtbl_rec.upd_marker = 0;
99 if (vol->vol_type == UBI_STATIC_VOLUME) {
101 vol->used_bytes = bytes;
102 vol->used_ebs = div_u64_rem(bytes, vol->usable_leb_size,
103 &vol->last_eb_bytes);
104 if (vol->last_eb_bytes)
107 vol->last_eb_bytes = vol->usable_leb_size;
110 mutex_lock(&ubi->device_mutex);
111 err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec);
113 mutex_unlock(&ubi->device_mutex);
118 * ubi_start_update - start volume update.
119 * @ubi: UBI device description object
120 * @vol: volume description object
121 * @bytes: update bytes
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.
127 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
132 dbg_gen("start update of volume %d, %llu bytes", vol->vol_id, bytes);
133 ubi_assert(!vol->updating && !vol->changing_leb);
136 err = set_update_marker(ubi, vol);
140 /* Before updating - wipe out the volume */
141 for (i = 0; i < vol->reserved_pebs; i++) {
142 err = ubi_eba_unmap_leb(ubi, vol, i);
148 err = ubi_wl_flush(ubi, UBI_ALL, UBI_ALL);
152 err = clear_update_marker(ubi, vol, 0);
159 vol->upd_buf = vmalloc(ubi->leb_size);
163 vol->upd_ebs = div_u64(bytes + vol->usable_leb_size - 1,
164 vol->usable_leb_size);
165 vol->upd_bytes = bytes;
166 vol->upd_received = 0;
171 * ubi_start_leb_change - start atomic LEB change.
172 * @ubi: UBI device description object
173 * @vol: volume description object
174 * @req: operation request
176 * This function starts atomic LEB change operation. Returns zero in case of
177 * success and a negative error code in case of failure.
179 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
180 const struct ubi_leb_change_req *req)
182 ubi_assert(!vol->updating && !vol->changing_leb);
184 dbg_gen("start changing LEB %d:%d, %u bytes",
185 vol->vol_id, req->lnum, req->bytes);
187 return ubi_eba_atomic_leb_change(ubi, vol, req->lnum, NULL, 0);
189 vol->upd_bytes = req->bytes;
190 vol->upd_received = 0;
191 vol->changing_leb = 1;
192 vol->ch_lnum = req->lnum;
194 vol->upd_buf = vmalloc(req->bytes);
202 * write_leb - write update data.
203 * @ubi: UBI device description object
204 * @vol: volume description object
205 * @lnum: logical eraseblock number
206 * @buf: data to write
208 * @used_ebs: how many logical eraseblocks will this volume contain (static
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.
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.
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
227 * This function returns zero in case of success and a negative error code in
230 static int write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
231 void *buf, int len, int used_ebs)
235 if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
236 int l = ALIGN(len, ubi->min_io_size);
238 memset(buf + len, 0xFF, l - len);
239 len = ubi_calc_data_len(ubi, buf, l);
241 dbg_gen("all %d bytes contain 0xFF - skip", len);
245 err = ubi_eba_write_leb(ubi, vol, lnum, buf, 0, len);
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.
256 memset(buf + len, 0, vol->usable_leb_size - len);
257 err = ubi_eba_write_leb_st(ubi, vol, lnum, buf, len, used_ebs);
264 * ubi_more_update_data - write more update data.
265 * @ubi: UBI device description object
266 * @vol: volume description object
267 * @buf: write data (user-space memory buffer)
268 * @count: how much bytes to write
270 * This function writes more data to the volume which is being updated. It may
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
274 * negative error code in case of failure.
276 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
277 const void __user *buf, int count)
279 int lnum, offs, err = 0, len, to_write = count;
281 dbg_gen("write %d of %lld bytes, %lld already passed",
282 count, vol->upd_bytes, vol->upd_received);
287 lnum = div_u64_rem(vol->upd_received, vol->usable_leb_size, &offs);
288 if (vol->upd_received + count > vol->upd_bytes)
289 to_write = count = vol->upd_bytes - vol->upd_received;
292 * When updating volumes, we accumulate whole logical eraseblock of
293 * data and write it at once.
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
303 len = vol->usable_leb_size - offs;
307 err = copy_from_user(vol->upd_buf + offs, buf, len);
311 if (offs + len == vol->usable_leb_size ||
312 vol->upd_received + len == vol->upd_bytes) {
313 int flush_len = offs + len;
316 * OK, we gathered either the whole eraseblock or this
317 * is the last chunk, it's time to flush the buffer.
319 ubi_assert(flush_len <= vol->usable_leb_size);
320 err = write_leb(ubi, vol, lnum, vol->upd_buf, flush_len,
326 vol->upd_received += len;
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.
337 if (count > vol->usable_leb_size)
338 len = vol->usable_leb_size;
342 err = copy_from_user(vol->upd_buf, buf, len);
346 if (len == vol->usable_leb_size ||
347 vol->upd_received + len == vol->upd_bytes) {
348 err = write_leb(ubi, vol, lnum, vol->upd_buf,
354 vol->upd_received += len;
360 ubi_assert(vol->upd_received <= vol->upd_bytes);
361 if (vol->upd_received == vol->upd_bytes) {
362 err = ubi_wl_flush(ubi, UBI_ALL, UBI_ALL);
365 /* The update is finished, clear the update marker */
366 err = clear_update_marker(ubi, vol, vol->upd_bytes);
378 * ubi_more_leb_change_data - accept more data for atomic LEB change.
379 * @ubi: UBI device description object
380 * @vol: volume description object
381 * @buf: write data (user-space memory buffer)
382 * @count: how much bytes to write
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
391 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
392 const void __user *buf, int count)
396 dbg_gen("write %d of %lld bytes, %lld already passed",
397 count, vol->upd_bytes, vol->upd_received);
402 if (vol->upd_received + count > vol->upd_bytes)
403 count = vol->upd_bytes - vol->upd_received;
405 err = copy_from_user(vol->upd_buf + vol->upd_received, buf, count);
409 vol->upd_received += count;
411 if (vol->upd_received == vol->upd_bytes) {
412 int len = ALIGN((int)vol->upd_bytes, ubi->min_io_size);
414 memset(vol->upd_buf + vol->upd_bytes, 0xFF,
415 len - vol->upd_bytes);
416 len = ubi_calc_data_len(ubi, vol->upd_buf, len);
417 err = ubi_eba_atomic_leb_change(ubi, vol, vol->ch_lnum,
423 ubi_assert(vol->upd_received <= vol->upd_bytes);
424 if (vol->upd_received == vol->upd_bytes) {
425 vol->changing_leb = 0;