2 * Copyright (c) International Business Machines Corp., 2006
3 * Copyright (c) Nokia Corporation, 2006
5 * SPDX-License-Identifier: GPL-2.0+
7 * Author: Artem Bityutskiy (Битюцкий Артём)
9 * Jan 2007: Alexander Schmidt, hacked per-volume update.
13 * This file contains implementation of the volume update and atomic LEB change
16 * The update operation is based on the per-volume update marker which is
17 * stored in the volume table. The update marker is set before the update
18 * starts, and removed after the update has been finished. So if the update was
19 * interrupted by an unclean re-boot or due to some other reasons, the update
20 * marker stays on the flash media and UBI finds it when it attaches the MTD
21 * device next time. If the update marker is set for a volume, the volume is
22 * treated as damaged and most I/O operations are prohibited. Only a new update
23 * operation is allowed.
25 * Note, in general it is possible to implement the update operation as a
26 * transaction with a roll-back capability.
30 #include <linux/err.h>
31 #include <asm/uaccess.h>
32 #include <asm/div64.h>
35 #include <ubi_uboot.h>
39 * set_update_marker - set update marker.
40 * @ubi: UBI device description object
41 * @vol: volume description object
43 * This function sets the update marker flag for volume @vol. Returns zero
44 * in case of success and a negative error code in case of failure.
46 static int set_update_marker(struct ubi_device *ubi, struct ubi_volume *vol)
49 struct ubi_vtbl_record vtbl_rec;
51 dbg_msg("set update marker for volume %d", vol->vol_id);
53 if (vol->upd_marker) {
54 ubi_assert(ubi->vtbl[vol->vol_id].upd_marker);
55 dbg_msg("already set");
59 memcpy(&vtbl_rec, &ubi->vtbl[vol->vol_id],
60 sizeof(struct ubi_vtbl_record));
61 vtbl_rec.upd_marker = 1;
63 mutex_lock(&ubi->volumes_mutex);
64 err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec);
65 mutex_unlock(&ubi->volumes_mutex);
71 * clear_update_marker - clear update marker.
72 * @ubi: UBI device description object
73 * @vol: volume description object
74 * @bytes: new data size in bytes
76 * This function clears the update marker for volume @vol, sets new volume
77 * data size and clears the "corrupted" flag (static volumes only). Returns
78 * zero in case of success and a negative error code in case of failure.
80 static int clear_update_marker(struct ubi_device *ubi, struct ubi_volume *vol,
85 struct ubi_vtbl_record vtbl_rec;
87 dbg_msg("clear update marker for volume %d", vol->vol_id);
89 memcpy(&vtbl_rec, &ubi->vtbl[vol->vol_id],
90 sizeof(struct ubi_vtbl_record));
91 ubi_assert(vol->upd_marker && vtbl_rec.upd_marker);
92 vtbl_rec.upd_marker = 0;
94 if (vol->vol_type == UBI_STATIC_VOLUME) {
96 vol->used_bytes = tmp = bytes;
97 vol->last_eb_bytes = do_div(tmp, vol->usable_leb_size);
99 if (vol->last_eb_bytes)
102 vol->last_eb_bytes = vol->usable_leb_size;
105 mutex_lock(&ubi->volumes_mutex);
106 err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec);
107 mutex_unlock(&ubi->volumes_mutex);
113 * ubi_start_update - start volume update.
114 * @ubi: UBI device description object
115 * @vol: volume description object
116 * @bytes: update bytes
118 * This function starts volume update operation. If @bytes is zero, the volume
119 * is just wiped out. Returns zero in case of success and a negative error code
120 * in case of failure.
122 int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
128 dbg_msg("start update of volume %d, %llu bytes", vol->vol_id, bytes);
129 ubi_assert(!vol->updating && !vol->changing_leb);
132 err = set_update_marker(ubi, vol);
136 /* Before updating - wipe out the volume */
137 for (i = 0; i < vol->reserved_pebs; i++) {
138 err = ubi_eba_unmap_leb(ubi, vol, i);
144 err = clear_update_marker(ubi, vol, 0);
147 err = ubi_wl_flush(ubi);
152 vol->upd_buf = vmalloc(ubi->leb_size);
157 vol->upd_ebs = !!do_div(tmp, vol->usable_leb_size);
159 vol->upd_bytes = bytes;
160 vol->upd_received = 0;
165 * ubi_start_leb_change - start atomic LEB change.
166 * @ubi: UBI device description object
167 * @vol: volume description object
168 * @req: operation request
170 * This function starts atomic LEB change operation. Returns zero in case of
171 * success and a negative error code in case of failure.
173 int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
174 const struct ubi_leb_change_req *req)
176 ubi_assert(!vol->updating && !vol->changing_leb);
178 dbg_msg("start changing LEB %d:%d, %u bytes",
179 vol->vol_id, req->lnum, req->bytes);
181 return ubi_eba_atomic_leb_change(ubi, vol, req->lnum, NULL, 0,
184 vol->upd_bytes = req->bytes;
185 vol->upd_received = 0;
186 vol->changing_leb = 1;
187 vol->ch_lnum = req->lnum;
188 vol->ch_dtype = req->dtype;
190 vol->upd_buf = vmalloc(req->bytes);
198 * write_leb - write update data.
199 * @ubi: UBI device description object
200 * @vol: volume description object
201 * @lnum: logical eraseblock number
202 * @buf: data to write
204 * @used_ebs: how many logical eraseblocks will this volume contain (static
207 * This function writes update data to corresponding logical eraseblock. In
208 * case of dynamic volume, this function checks if the data contains 0xFF bytes
209 * at the end. If yes, the 0xFF bytes are cut and not written. So if the whole
210 * buffer contains only 0xFF bytes, the LEB is left unmapped.
212 * The reason why we skip the trailing 0xFF bytes in case of dynamic volume is
213 * that we want to make sure that more data may be appended to the logical
214 * eraseblock in future. Indeed, writing 0xFF bytes may have side effects and
215 * this PEB won't be writable anymore. So if one writes the file-system image
216 * to the UBI volume where 0xFFs mean free space - UBI makes sure this free
217 * space is writable after the update.
219 * We do not do this for static volumes because they are read-only. But this
220 * also cannot be done because we have to store per-LEB CRC and the correct
223 * This function returns zero in case of success and a negative error code in
226 static int write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
227 void *buf, int len, int used_ebs)
231 if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
232 int l = ALIGN(len, ubi->min_io_size);
234 memset(buf + len, 0xFF, l - len);
235 len = ubi_calc_data_len(ubi, buf, l);
237 dbg_msg("all %d bytes contain 0xFF - skip", len);
241 err = ubi_eba_write_leb(ubi, vol, lnum, buf, 0, len, UBI_UNKNOWN);
244 * When writing static volume, and this is the last logical
245 * eraseblock, the length (@len) does not have to be aligned to
246 * the minimal flash I/O unit. The 'ubi_eba_write_leb_st()'
247 * function accepts exact (unaligned) length and stores it in
248 * the VID header. And it takes care of proper alignment by
249 * padding the buffer. Here we just make sure the padding will
250 * contain zeros, not random trash.
252 memset(buf + len, 0, vol->usable_leb_size - len);
253 err = ubi_eba_write_leb_st(ubi, vol, lnum, buf, len,
254 UBI_UNKNOWN, used_ebs);
261 * ubi_more_update_data - write more update data.
262 * @vol: volume description object
263 * @buf: write data (user-space memory buffer)
264 * @count: how much bytes to write
266 * This function writes more data to the volume which is being updated. It may
267 * be called arbitrary number of times until all the update data arriveis. This
268 * function returns %0 in case of success, number of bytes written during the
269 * last call if the whole volume update has been successfully finished, and a
270 * negative error code in case of failure.
272 int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
273 const void __user *buf, int count)
276 int lnum, offs, err = 0, len, to_write = count;
278 dbg_msg("write %d of %lld bytes, %lld already passed",
279 count, vol->upd_bytes, vol->upd_received);
284 tmp = vol->upd_received;
285 offs = do_div(tmp, vol->usable_leb_size);
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 /* The update is finished, clear the update marker */
363 err = clear_update_marker(ubi, vol, vol->upd_bytes);
366 err = ubi_wl_flush(ubi);
378 * ubi_more_leb_change_data - accept more data for atomic LEB change.
379 * @vol: volume description object
380 * @buf: write data (user-space memory buffer)
381 * @count: how much bytes to write
383 * This function accepts more data to the volume which is being under the
384 * "atomic LEB change" operation. It may be called arbitrary number of times
385 * until all data arrives. This function returns %0 in case of success, number
386 * of bytes written during the last call if the whole "atomic LEB change"
387 * operation has been successfully finished, and a negative error code in case
390 int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
391 const void __user *buf, int count)
395 dbg_msg("write %d of %lld bytes, %lld already passed",
396 count, vol->upd_bytes, vol->upd_received);
401 if (vol->upd_received + count > vol->upd_bytes)
402 count = vol->upd_bytes - vol->upd_received;
404 err = copy_from_user(vol->upd_buf + vol->upd_received, buf, count);
408 vol->upd_received += count;
410 if (vol->upd_received == vol->upd_bytes) {
411 int len = ALIGN((int)vol->upd_bytes, ubi->min_io_size);
413 memset(vol->upd_buf + vol->upd_bytes, 0xFF, len - vol->upd_bytes);
414 len = ubi_calc_data_len(ubi, vol->upd_buf, len);
415 err = ubi_eba_atomic_leb_change(ubi, vol, vol->ch_lnum,
416 vol->upd_buf, len, UBI_UNKNOWN);
421 ubi_assert(vol->upd_received <= vol->upd_bytes);
422 if (vol->upd_received == vol->upd_bytes) {
423 vol->changing_leb = 0;