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 memcpy(&vtbl_rec, &ubi->vtbl[vol->vol_id],
68 sizeof(struct ubi_vtbl_record));
69 vtbl_rec.upd_marker = 1;
71 mutex_lock(&ubi->device_mutex);
72 err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec);
74 mutex_unlock(&ubi->device_mutex);
79 * clear_update_marker - clear update marker.
80 * @ubi: UBI device description object
81 * @vol: volume description object
82 * @bytes: new data size in bytes
84 * This function clears the update marker for volume @vol, sets new volume
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.
88 static int clear_update_marker(struct ubi_device *ubi, struct ubi_volume *vol,
92 struct ubi_vtbl_record vtbl_rec;
94 dbg_gen("clear update marker for volume %d", vol->vol_id);
96 memcpy(&vtbl_rec, &ubi->vtbl[vol->vol_id],
97 sizeof(struct ubi_vtbl_record));
98 ubi_assert(vol->upd_marker && vtbl_rec.upd_marker);
99 vtbl_rec.upd_marker = 0;
101 if (vol->vol_type == UBI_STATIC_VOLUME) {
103 vol->used_bytes = bytes;
104 vol->used_ebs = div_u64_rem(bytes, vol->usable_leb_size,
105 &vol->last_eb_bytes);
106 if (vol->last_eb_bytes)
109 vol->last_eb_bytes = vol->usable_leb_size;
112 mutex_lock(&ubi->device_mutex);
113 err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec);
115 mutex_unlock(&ubi->device_mutex);
120 * ubi_start_update - start volume update.
121 * @ubi: UBI device description object
122 * @vol: volume description object
123 * @bytes: update bytes
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.
129 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
134 dbg_gen("start update of volume %d, %llu bytes", vol->vol_id, bytes);
135 ubi_assert(!vol->updating && !vol->changing_leb);
138 vol->upd_buf = vmalloc(ubi->leb_size);
142 err = set_update_marker(ubi, vol);
146 /* Before updating - wipe out the volume */
147 for (i = 0; i < vol->reserved_pebs; i++) {
148 err = ubi_eba_unmap_leb(ubi, vol, i);
154 err = ubi_wl_flush(ubi);
158 err = clear_update_marker(ubi, vol, 0);
167 vol->upd_ebs = div_u64(bytes + vol->usable_leb_size - 1,
168 vol->usable_leb_size);
169 vol->upd_bytes = bytes;
170 vol->upd_received = 0;
175 * ubi_start_leb_change - start atomic LEB change.
176 * @ubi: UBI device description object
177 * @vol: volume description object
178 * @req: operation request
180 * This function starts atomic LEB change operation. Returns zero in case of
181 * success and a negative error code in case of failure.
183 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
184 const struct ubi_leb_change_req *req)
186 ubi_assert(!vol->updating && !vol->changing_leb);
188 dbg_gen("start changing LEB %d:%d, %u bytes",
189 vol->vol_id, req->lnum, req->bytes);
191 return ubi_eba_atomic_leb_change(ubi, vol, req->lnum, NULL, 0,
194 vol->upd_bytes = req->bytes;
195 vol->upd_received = 0;
196 vol->changing_leb = 1;
197 vol->ch_lnum = req->lnum;
198 vol->ch_dtype = req->dtype;
200 vol->upd_buf = vmalloc(req->bytes);
208 * write_leb - write update data.
209 * @ubi: UBI device description object
210 * @vol: volume description object
211 * @lnum: logical eraseblock number
212 * @buf: data to write
214 * @used_ebs: how many logical eraseblocks will this volume contain (static
217 * This function writes update data to corresponding logical eraseblock. In
218 * case of dynamic volume, this function checks if the data contains 0xFF bytes
219 * at the end. If yes, the 0xFF bytes are cut and not written. So if the whole
220 * buffer contains only 0xFF bytes, the LEB is left unmapped.
222 * The reason why we skip the trailing 0xFF bytes in case of dynamic volume is
223 * that we want to make sure that more data may be appended to the logical
224 * eraseblock in future. Indeed, writing 0xFF bytes may have side effects and
225 * this PEB won't be writable anymore. So if one writes the file-system image
226 * to the UBI volume where 0xFFs mean free space - UBI makes sure this free
227 * space is writable after the update.
229 * We do not do this for static volumes because they are read-only. But this
230 * also cannot be done because we have to store per-LEB CRC and the correct
233 * This function returns zero in case of success and a negative error code in
236 static int write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
237 void *buf, int len, int used_ebs)
241 if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
242 int l = ALIGN(len, ubi->min_io_size);
244 memset(buf + len, 0xFF, l - len);
245 len = ubi_calc_data_len(ubi, buf, l);
247 dbg_gen("all %d bytes contain 0xFF - skip", len);
251 err = ubi_eba_write_leb(ubi, vol, lnum, buf, 0, len,
255 * When writing static volume, and this is the last logical
256 * eraseblock, the length (@len) does not have to be aligned to
257 * the minimal flash I/O unit. The 'ubi_eba_write_leb_st()'
258 * function accepts exact (unaligned) length and stores it in
259 * the VID header. And it takes care of proper alignment by
260 * padding the buffer. Here we just make sure the padding will
261 * contain zeros, not random trash.
263 memset(buf + len, 0, vol->usable_leb_size - len);
264 err = ubi_eba_write_leb_st(ubi, vol, lnum, buf, len,
265 UBI_UNKNOWN, used_ebs);
272 * ubi_more_update_data - write more update data.
273 * @ubi: UBI device description object
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)
287 int lnum, offs, err = 0, len, to_write = count;
289 dbg_gen("write %d of %lld bytes, %lld already passed",
290 count, vol->upd_bytes, vol->upd_received);
295 lnum = div_u64_rem(vol->upd_received, vol->usable_leb_size, &offs);
296 if (vol->upd_received + count > vol->upd_bytes)
297 to_write = count = vol->upd_bytes - vol->upd_received;
300 * When updating volumes, we accumulate whole logical eraseblock of
301 * data and write it at once.
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
311 len = vol->usable_leb_size - offs;
315 err = copy_from_user(vol->upd_buf + offs, buf, len);
319 if (offs + len == vol->usable_leb_size ||
320 vol->upd_received + len == vol->upd_bytes) {
321 int flush_len = offs + len;
324 * OK, we gathered either the whole eraseblock or this
325 * is the last chunk, it's time to flush the buffer.
327 ubi_assert(flush_len <= vol->usable_leb_size);
328 err = write_leb(ubi, vol, lnum, vol->upd_buf, flush_len,
334 vol->upd_received += len;
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.
345 if (count > vol->usable_leb_size)
346 len = vol->usable_leb_size;
350 err = copy_from_user(vol->upd_buf, buf, len);
354 if (len == vol->usable_leb_size ||
355 vol->upd_received + len == vol->upd_bytes) {
356 err = write_leb(ubi, vol, lnum, vol->upd_buf,
362 vol->upd_received += len;
368 ubi_assert(vol->upd_received <= vol->upd_bytes);
369 if (vol->upd_received == vol->upd_bytes) {
370 err = ubi_wl_flush(ubi);
373 /* The update is finished, clear the update marker */
374 err = clear_update_marker(ubi, vol, vol->upd_bytes);
386 * ubi_more_leb_change_data - accept more data for atomic LEB change.
387 * @ubi: UBI device description object
388 * @vol: volume description object
389 * @buf: write data (user-space memory buffer)
390 * @count: how much bytes to write
392 * This function accepts more data to the volume which is being under the
393 * "atomic LEB change" operation. It may be called arbitrary number of times
394 * until all data arrives. This function returns %0 in case of success, number
395 * of bytes written during the last call if the whole "atomic LEB change"
396 * operation has been successfully finished, and a negative error code in case
399 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
400 const void __user *buf, int count)
404 dbg_gen("write %d of %lld bytes, %lld already passed",
405 count, vol->upd_bytes, vol->upd_received);
410 if (vol->upd_received + count > vol->upd_bytes)
411 count = vol->upd_bytes - vol->upd_received;
413 err = copy_from_user(vol->upd_buf + vol->upd_received, buf, count);
417 vol->upd_received += count;
419 if (vol->upd_received == vol->upd_bytes) {
420 int len = ALIGN((int)vol->upd_bytes, ubi->min_io_size);
422 memset(vol->upd_buf + vol->upd_bytes, 0xFF,
423 len - vol->upd_bytes);
424 len = ubi_calc_data_len(ubi, vol->upd_buf, len);
425 err = ubi_eba_atomic_leb_change(ubi, vol, vol->ch_lnum,
426 vol->upd_buf, len, UBI_UNKNOWN);
431 ubi_assert(vol->upd_received <= vol->upd_bytes);
432 if (vol->upd_received == vol->upd_bytes) {
433 vol->changing_leb = 0;