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.
42 #include <linux/err.h>
43 #include <asm/uaccess.h>
44 #include <asm/div64.h>
47 #include <ubi_uboot.h>
51 * set_update_marker - set update marker.
52 * @ubi: UBI device description object
53 * @vol: volume description object
55 * This function sets the update marker flag for volume @vol. Returns zero
56 * in case of success and a negative error code in case of failure.
58 static int set_update_marker(struct ubi_device *ubi, struct ubi_volume *vol)
61 struct ubi_vtbl_record vtbl_rec;
63 dbg_msg("set update marker for volume %d", vol->vol_id);
65 if (vol->upd_marker) {
66 ubi_assert(ubi->vtbl[vol->vol_id].upd_marker);
67 dbg_msg("already set");
71 memcpy(&vtbl_rec, &ubi->vtbl[vol->vol_id],
72 sizeof(struct ubi_vtbl_record));
73 vtbl_rec.upd_marker = 1;
75 mutex_lock(&ubi->volumes_mutex);
76 err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec);
77 mutex_unlock(&ubi->volumes_mutex);
83 * clear_update_marker - clear update marker.
84 * @ubi: UBI device description object
85 * @vol: volume description object
86 * @bytes: new data size in bytes
88 * This function clears the update marker for volume @vol, sets new volume
89 * data size and clears the "corrupted" flag (static volumes only). Returns
90 * zero in case of success and a negative error code in case of failure.
92 static int clear_update_marker(struct ubi_device *ubi, struct ubi_volume *vol,
97 struct ubi_vtbl_record vtbl_rec;
99 dbg_msg("clear update marker for volume %d", vol->vol_id);
101 memcpy(&vtbl_rec, &ubi->vtbl[vol->vol_id],
102 sizeof(struct ubi_vtbl_record));
103 ubi_assert(vol->upd_marker && vtbl_rec.upd_marker);
104 vtbl_rec.upd_marker = 0;
106 if (vol->vol_type == UBI_STATIC_VOLUME) {
108 vol->used_bytes = tmp = bytes;
109 vol->last_eb_bytes = do_div(tmp, vol->usable_leb_size);
111 if (vol->last_eb_bytes)
114 vol->last_eb_bytes = vol->usable_leb_size;
117 mutex_lock(&ubi->volumes_mutex);
118 err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec);
119 mutex_unlock(&ubi->volumes_mutex);
125 * ubi_start_update - start volume update.
126 * @ubi: UBI device description object
127 * @vol: volume description object
128 * @bytes: update bytes
130 * This function starts volume update operation. If @bytes is zero, the volume
131 * is just wiped out. Returns zero in case of success and a negative error code
132 * in case of failure.
134 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
140 dbg_msg("start update of volume %d, %llu bytes", vol->vol_id, bytes);
141 ubi_assert(!vol->updating && !vol->changing_leb);
144 err = set_update_marker(ubi, vol);
148 /* Before updating - wipe out the volume */
149 for (i = 0; i < vol->reserved_pebs; i++) {
150 err = ubi_eba_unmap_leb(ubi, vol, i);
156 err = clear_update_marker(ubi, vol, 0);
159 err = ubi_wl_flush(ubi);
164 vol->upd_buf = vmalloc(ubi->leb_size);
169 vol->upd_ebs = !!do_div(tmp, vol->usable_leb_size);
171 vol->upd_bytes = bytes;
172 vol->upd_received = 0;
177 * ubi_start_leb_change - start atomic LEB change.
178 * @ubi: UBI device description object
179 * @vol: volume description object
180 * @req: operation request
182 * This function starts atomic LEB change operation. Returns zero in case of
183 * success and a negative error code in case of failure.
185 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
186 const struct ubi_leb_change_req *req)
188 ubi_assert(!vol->updating && !vol->changing_leb);
190 dbg_msg("start changing LEB %d:%d, %u bytes",
191 vol->vol_id, req->lnum, req->bytes);
193 return ubi_eba_atomic_leb_change(ubi, vol, req->lnum, NULL, 0,
196 vol->upd_bytes = req->bytes;
197 vol->upd_received = 0;
198 vol->changing_leb = 1;
199 vol->ch_lnum = req->lnum;
200 vol->ch_dtype = req->dtype;
202 vol->upd_buf = vmalloc(req->bytes);
210 * write_leb - write update data.
211 * @ubi: UBI device description object
212 * @vol: volume description object
213 * @lnum: logical eraseblock number
214 * @buf: data to write
216 * @used_ebs: how many logical eraseblocks will this volume contain (static
219 * This function writes update data to corresponding logical eraseblock. In
220 * case of dynamic volume, this function checks if the data contains 0xFF bytes
221 * at the end. If yes, the 0xFF bytes are cut and not written. So if the whole
222 * buffer contains only 0xFF bytes, the LEB is left unmapped.
224 * The reason why we skip the trailing 0xFF bytes in case of dynamic volume is
225 * that we want to make sure that more data may be appended to the logical
226 * eraseblock in future. Indeed, writing 0xFF bytes may have side effects and
227 * this PEB won't be writable anymore. So if one writes the file-system image
228 * to the UBI volume where 0xFFs mean free space - UBI makes sure this free
229 * space is writable after the update.
231 * We do not do this for static volumes because they are read-only. But this
232 * also cannot be done because we have to store per-LEB CRC and the correct
235 * This function returns zero in case of success and a negative error code in
238 static int write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
239 void *buf, int len, int used_ebs)
243 if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
244 int l = ALIGN(len, ubi->min_io_size);
246 memset(buf + len, 0xFF, l - len);
247 len = ubi_calc_data_len(ubi, buf, l);
249 dbg_msg("all %d bytes contain 0xFF - skip", len);
253 err = ubi_eba_write_leb(ubi, vol, lnum, buf, 0, len, UBI_UNKNOWN);
256 * When writing static volume, and this is the last logical
257 * eraseblock, the length (@len) does not have to be aligned to
258 * the minimal flash I/O unit. The 'ubi_eba_write_leb_st()'
259 * function accepts exact (unaligned) length and stores it in
260 * the VID header. And it takes care of proper alignment by
261 * padding the buffer. Here we just make sure the padding will
262 * contain zeros, not random trash.
264 memset(buf + len, 0, vol->usable_leb_size - len);
265 err = ubi_eba_write_leb_st(ubi, vol, lnum, buf, len,
266 UBI_UNKNOWN, used_ebs);
273 * ubi_more_update_data - write more update data.
274 * @vol: volume description object
275 * @buf: write data (user-space memory buffer)
276 * @count: how much bytes to write
278 * This function writes more data to the volume which is being updated. It may
279 * be called arbitrary number of times until all the update data arriveis. This
280 * function returns %0 in case of success, number of bytes written during the
281 * last call if the whole volume update has been successfully finished, and a
282 * negative error code in case of failure.
284 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
285 const void __user *buf, int count)
288 int lnum, offs, err = 0, len, to_write = count;
290 dbg_msg("write %d of %lld bytes, %lld already passed",
291 count, vol->upd_bytes, vol->upd_received);
296 tmp = vol->upd_received;
297 offs = do_div(tmp, vol->usable_leb_size);
300 if (vol->upd_received + count > vol->upd_bytes)
301 to_write = count = vol->upd_bytes - vol->upd_received;
304 * When updating volumes, we accumulate whole logical eraseblock of
305 * data and write it at once.
309 * This is a write to the middle of the logical eraseblock. We
310 * copy the data to our update buffer and wait for more data or
311 * flush it if the whole eraseblock is written or the update
315 len = vol->usable_leb_size - offs;
319 err = copy_from_user(vol->upd_buf + offs, buf, len);
323 if (offs + len == vol->usable_leb_size ||
324 vol->upd_received + len == vol->upd_bytes) {
325 int flush_len = offs + len;
328 * OK, we gathered either the whole eraseblock or this
329 * is the last chunk, it's time to flush the buffer.
331 ubi_assert(flush_len <= vol->usable_leb_size);
332 err = write_leb(ubi, vol, lnum, vol->upd_buf, flush_len,
338 vol->upd_received += len;
345 * If we've got more to write, let's continue. At this point we know we
346 * are starting from the beginning of an eraseblock.
349 if (count > vol->usable_leb_size)
350 len = vol->usable_leb_size;
354 err = copy_from_user(vol->upd_buf, buf, len);
358 if (len == vol->usable_leb_size ||
359 vol->upd_received + len == vol->upd_bytes) {
360 err = write_leb(ubi, vol, lnum, vol->upd_buf,
366 vol->upd_received += len;
372 ubi_assert(vol->upd_received <= vol->upd_bytes);
373 if (vol->upd_received == vol->upd_bytes) {
374 /* The update is finished, clear the update marker */
375 err = clear_update_marker(ubi, vol, vol->upd_bytes);
378 err = ubi_wl_flush(ubi);
390 * ubi_more_leb_change_data - accept more data for atomic LEB change.
391 * @vol: volume description object
392 * @buf: write data (user-space memory buffer)
393 * @count: how much bytes to write
395 * This function accepts more data to the volume which is being under the
396 * "atomic LEB change" operation. It may be called arbitrary number of times
397 * until all data arrives. This function returns %0 in case of success, number
398 * of bytes written during the last call if the whole "atomic LEB change"
399 * operation has been successfully finished, and a negative error code in case
402 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
403 const void __user *buf, int count)
407 dbg_msg("write %d of %lld bytes, %lld already passed",
408 count, vol->upd_bytes, vol->upd_received);
413 if (vol->upd_received + count > vol->upd_bytes)
414 count = vol->upd_bytes - vol->upd_received;
416 err = copy_from_user(vol->upd_buf + vol->upd_received, buf, count);
420 vol->upd_received += count;
422 if (vol->upd_received == vol->upd_bytes) {
423 int len = ALIGN((int)vol->upd_bytes, ubi->min_io_size);
425 memset(vol->upd_buf + vol->upd_bytes, 0xFF, len - vol->upd_bytes);
426 len = ubi_calc_data_len(ubi, vol->upd_buf, len);
427 err = ubi_eba_atomic_leb_change(ubi, vol, vol->ch_lnum,
428 vol->upd_buf, len, UBI_UNKNOWN);
433 ubi_assert(vol->upd_received <= vol->upd_bytes);
434 if (vol->upd_received == vol->upd_bytes) {
435 vol->changing_leb = 0;