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1/*
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/*
25 * This file contains implementation of the volume update and atomic LEB change
26 * functionality.
27 *
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 <linux/uaccess.h>
43#include <linux/math64.h>
44#include "ubi.h"
45
46/**
47 * set_update_marker - set update marker.
48 * @ubi: UBI device description object
49 * @vol: volume description object
50 *
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.
53 */
54static int set_update_marker(struct ubi_device *ubi, struct ubi_volume *vol)
55{
56 int err;
57 struct ubi_vtbl_record vtbl_rec;
58
59 dbg_gen("set update marker for volume %d", vol->vol_id);
60
61 if (vol->upd_marker) {
62 ubi_assert(ubi->vtbl[vol->vol_id].upd_marker);
63 dbg_gen("already set");
64 return 0;
65 }
66
67 memcpy(&vtbl_rec, &ubi->vtbl[vol->vol_id],
68 sizeof(struct ubi_vtbl_record));
69 vtbl_rec.upd_marker = 1;
70
71 mutex_lock(&ubi->device_mutex);
72 err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec);
73 vol->upd_marker = 1;
74 mutex_unlock(&ubi->device_mutex);
75 return err;
76}
77
78/**
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
83 *
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.
87 */
88static int clear_update_marker(struct ubi_device *ubi, struct ubi_volume *vol,
89 long long bytes)
90{
91 int err;
92 struct ubi_vtbl_record vtbl_rec;
93
94 dbg_gen("clear update marker for volume %d", vol->vol_id);
95
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;
100
101 if (vol->vol_type == UBI_STATIC_VOLUME) {
102 vol->corrupted = 0;
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)
107 vol->used_ebs += 1;
108 else
109 vol->last_eb_bytes = vol->usable_leb_size;
110 }
111
112 mutex_lock(&ubi->device_mutex);
113 err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec);
114 vol->upd_marker = 0;
115 mutex_unlock(&ubi->device_mutex);
116 return err;
117}
118
119/**
120 * ubi_start_update - start volume update.
121 * @ubi: UBI device description object
122 * @vol: volume description object
123 * @bytes: update bytes
124 *
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.
128 */
129int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
130 long long bytes)
131{
132 int i, err;
133
134 dbg_gen("start update of volume %d, %llu bytes", vol->vol_id, bytes);
135 ubi_assert(!vol->updating && !vol->changing_leb);
136 vol->updating = 1;
137
138 err = set_update_marker(ubi, vol);
139 if (err)
140 return err;
141
142 /* Before updating - wipe out the volume */
143 for (i = 0; i < vol->reserved_pebs; i++) {
144 err = ubi_eba_unmap_leb(ubi, vol, i);
145 if (err)
146 return err;
147 }
148
149 if (bytes == 0) {
150 err = ubi_wl_flush(ubi);
151 if (err)
152 return err;
153
154 err = clear_update_marker(ubi, vol, 0);
155 if (err)
156 return err;
157 vol->updating = 0;
158 return 0;
159 }
160
161 vol->upd_buf = vmalloc(ubi->leb_size);
162 if (!vol->upd_buf)
163 return -ENOMEM;
164
165 vol->upd_ebs = div_u64(bytes + vol->usable_leb_size - 1,
166 vol->usable_leb_size);
167 vol->upd_bytes = bytes;
168 vol->upd_received = 0;
169 return 0;
170}
171
172/**
173 * 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_gen("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/**
206 * write_leb - write update data.
207 * @ubi: UBI device description object
208 * @vol: volume description object
209 * @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 */
234static int write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
235 void *buf, int len, int used_ebs)
236{
237 int err;
238
239 if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
240 int l = ALIGN(len, ubi->min_io_size);
241
242 memset(buf + len, 0xFF, l - len);
243 len = ubi_calc_data_len(ubi, buf, l);
244 if (len == 0) {
245 dbg_gen("all %d bytes contain 0xFF - skip", len);
246 return 0;
247 }
248
249 err = ubi_eba_write_leb(ubi, vol, lnum, buf, 0, len,
250 UBI_UNKNOWN);
251 } else {
252 /*
253 * When writing static volume, and this is the last logical
254 * eraseblock, the length (@len) does not have to be aligned to
255 * the minimal flash I/O unit. The 'ubi_eba_write_leb_st()'
256 * function accepts exact (unaligned) length and stores it in
257 * the VID header. And it takes care of proper alignment by
258 * padding the buffer. Here we just make sure the padding will
259 * contain zeros, not random trash.
260 */
261 memset(buf + len, 0, vol->usable_leb_size - len);
262 err = ubi_eba_write_leb_st(ubi, vol, lnum, buf, len,
263 UBI_UNKNOWN, used_ebs);
264 }
265
266 return err;
267}
268
269/**
270 * ubi_more_update_data - write more update data.
271 * @ubi: UBI device description object
272 * @vol: volume description object
273 * @buf: write data (user-space memory buffer)
274 * @count: how much bytes to write
275 *
276 * This function writes more data to the volume which is being updated. It may
277 * be called arbitrary number of times until all the update data arriveis. This
278 * function returns %0 in case of success, number of bytes written during the
279 * last call if the whole volume update has been successfully finished, and a
280 * negative error code in case of failure.
281 */
282int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
283 const void __user *buf, int count)
284{
285 int lnum, offs, err = 0, len, to_write = count;
286
287 dbg_gen("write %d of %lld bytes, %lld already passed",
288 count, vol->upd_bytes, vol->upd_received);
289
290 if (ubi->ro_mode)
291 return -EROFS;
292
293 lnum = div_u64_rem(vol->upd_received, vol->usable_leb_size, &offs);
294 if (vol->upd_received + count > vol->upd_bytes)
295 to_write = count = vol->upd_bytes - vol->upd_received;
296
297 /*
298 * When updating volumes, we accumulate whole logical eraseblock of
299 * data and write it at once.
300 */
301 if (offs != 0) {
302 /*
303 * This is a write to the middle of the logical eraseblock. We
304 * copy the data to our update buffer and wait for more data or
305 * flush it if the whole eraseblock is written or the update
306 * is finished.
307 */
308
309 len = vol->usable_leb_size - offs;
310 if (len > count)
311 len = count;
312
313 err = copy_from_user(vol->upd_buf + offs, buf, len);
314 if (err)
315 return -EFAULT;
316
317 if (offs + len == vol->usable_leb_size ||
318 vol->upd_received + len == vol->upd_bytes) {
319 int flush_len = offs + len;
320
321 /*
322 * OK, we gathered either the whole eraseblock or this
323 * is the last chunk, it's time to flush the buffer.
324 */
325 ubi_assert(flush_len <= vol->usable_leb_size);
326 err = write_leb(ubi, vol, lnum, vol->upd_buf, flush_len,
327 vol->upd_ebs);
328 if (err)
329 return err;
330 }
331
332 vol->upd_received += len;
333 count -= len;
334 buf += len;
335 lnum += 1;
336 }
337
338 /*
339 * If we've got more to write, let's continue. At this point we know we
340 * are starting from the beginning of an eraseblock.
341 */
342 while (count) {
343 if (count > vol->usable_leb_size)
344 len = vol->usable_leb_size;
345 else
346 len = count;
347
348 err = copy_from_user(vol->upd_buf, buf, len);
349 if (err)
350 return -EFAULT;
351
352 if (len == vol->usable_leb_size ||
353 vol->upd_received + len == vol->upd_bytes) {
354 err = write_leb(ubi, vol, lnum, vol->upd_buf,
355 len, vol->upd_ebs);
356 if (err)
357 break;
358 }
359
360 vol->upd_received += len;
361 count -= len;
362 lnum += 1;
363 buf += len;
364 }
365
366 ubi_assert(vol->upd_received <= vol->upd_bytes);
367 if (vol->upd_received == vol->upd_bytes) {
368 err = ubi_wl_flush(ubi);
369 if (err)
370 return err;
371 /* The update is finished, clear the update marker */
372 err = clear_update_marker(ubi, vol, vol->upd_bytes);
373 if (err)
374 return err;
375 vol->updating = 0;
376 err = to_write;
377 vfree(vol->upd_buf);
378 }
379
380 return err;
381}
382
383/**
384 * ubi_more_leb_change_data - accept more data for atomic LEB change.
385 * @ubi: UBI device description object
386 * @vol: volume description object
387 * @buf: write data (user-space memory buffer)
388 * @count: how much bytes to write
389 *
390 * This function accepts more data to the volume which is being under the
391 * "atomic LEB change" operation. It may be called arbitrary number of times
392 * until all data arrives. This function returns %0 in case of success, number
393 * of bytes written during the last call if the whole "atomic LEB change"
394 * operation has been successfully finished, and a negative error code in case
395 * of failure.
396 */
397int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
398 const void __user *buf, int count)
399{
400 int err;
401
402 dbg_gen("write %d of %lld bytes, %lld already passed",
403 count, vol->upd_bytes, vol->upd_received);
404
405 if (ubi->ro_mode)
406 return -EROFS;
407
408 if (vol->upd_received + count > vol->upd_bytes)
409 count = vol->upd_bytes - vol->upd_received;
410
411 err = copy_from_user(vol->upd_buf + vol->upd_received, buf, count);
412 if (err)
413 return -EFAULT;
414
415 vol->upd_received += count;
416
417 if (vol->upd_received == vol->upd_bytes) {
418 int len = ALIGN((int)vol->upd_bytes, ubi->min_io_size);
419
420 memset(vol->upd_buf + vol->upd_bytes, 0xFF,
421 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}
1/*
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/*
25 * This file contains implementation of the volume update and atomic LEB change
26 * functionality.
27 *
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 <linux/uaccess.h>
43#include <linux/math64.h>
44#include "ubi.h"
45
46/**
47 * set_update_marker - set update marker.
48 * @ubi: UBI device description object
49 * @vol: volume description object
50 *
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.
53 */
54static int set_update_marker(struct ubi_device *ubi, struct ubi_volume *vol)
55{
56 int err;
57 struct ubi_vtbl_record vtbl_rec;
58
59 dbg_gen("set update marker for volume %d", vol->vol_id);
60
61 if (vol->upd_marker) {
62 ubi_assert(ubi->vtbl[vol->vol_id].upd_marker);
63 dbg_gen("already set");
64 return 0;
65 }
66
67 memcpy(&vtbl_rec, &ubi->vtbl[vol->vol_id],
68 sizeof(struct ubi_vtbl_record));
69 vtbl_rec.upd_marker = 1;
70
71 mutex_lock(&ubi->device_mutex);
72 err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec);
73 vol->upd_marker = 1;
74 mutex_unlock(&ubi->device_mutex);
75 return err;
76}
77
78/**
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
83 *
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.
87 */
88static int clear_update_marker(struct ubi_device *ubi, struct ubi_volume *vol,
89 long long bytes)
90{
91 int err;
92 struct ubi_vtbl_record vtbl_rec;
93
94 dbg_gen("clear update marker for volume %d", vol->vol_id);
95
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;
100
101 if (vol->vol_type == UBI_STATIC_VOLUME) {
102 vol->corrupted = 0;
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)
107 vol->used_ebs += 1;
108 else
109 vol->last_eb_bytes = vol->usable_leb_size;
110 }
111
112 mutex_lock(&ubi->device_mutex);
113 err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec);
114 vol->upd_marker = 0;
115 mutex_unlock(&ubi->device_mutex);
116 return err;
117}
118
119/**
120 * ubi_start_update - start volume update.
121 * @ubi: UBI device description object
122 * @vol: volume description object
123 * @bytes: update bytes
124 *
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.
128 */
129int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
130 long long bytes)
131{
132 int i, err;
133
134 dbg_gen("start update of volume %d, %llu bytes", vol->vol_id, bytes);
135 ubi_assert(!vol->updating && !vol->changing_leb);
136 vol->updating = 1;
137
138 err = set_update_marker(ubi, vol);
139 if (err)
140 return err;
141
142 /* Before updating - wipe out the volume */
143 for (i = 0; i < vol->reserved_pebs; i++) {
144 err = ubi_eba_unmap_leb(ubi, vol, i);
145 if (err)
146 return err;
147 }
148
149 if (bytes == 0) {
150 err = ubi_wl_flush(ubi, UBI_ALL, UBI_ALL);
151 if (err)
152 return err;
153
154 err = clear_update_marker(ubi, vol, 0);
155 if (err)
156 return err;
157 vol->updating = 0;
158 return 0;
159 }
160
161 vol->upd_buf = vmalloc(ubi->leb_size);
162 if (!vol->upd_buf)
163 return -ENOMEM;
164
165 vol->upd_ebs = div_u64(bytes + vol->usable_leb_size - 1,
166 vol->usable_leb_size);
167 vol->upd_bytes = bytes;
168 vol->upd_received = 0;
169 return 0;
170}
171
172/**
173 * 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_gen("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
191 vol->upd_bytes = req->bytes;
192 vol->upd_received = 0;
193 vol->changing_leb = 1;
194 vol->ch_lnum = req->lnum;
195
196 vol->upd_buf = vmalloc(req->bytes);
197 if (!vol->upd_buf)
198 return -ENOMEM;
199
200 return 0;
201}
202
203/**
204 * write_leb - write update data.
205 * @ubi: UBI device description object
206 * @vol: volume description object
207 * @lnum: logical eraseblock number
208 * @buf: data to write
209 * @len: data size
210 * @used_ebs: how many logical eraseblocks will this volume contain (static
211 * volumes only)
212 *
213 * This function writes update data to corresponding logical eraseblock. In
214 * case of dynamic volume, this function checks if the data contains 0xFF bytes
215 * at the end. If yes, the 0xFF bytes are cut and not written. So if the whole
216 * buffer contains only 0xFF bytes, the LEB is left unmapped.
217 *
218 * The reason why we skip the trailing 0xFF bytes in case of dynamic volume is
219 * that we want to make sure that more data may be appended to the logical
220 * eraseblock in future. Indeed, writing 0xFF bytes may have side effects and
221 * this PEB won't be writable anymore. So if one writes the file-system image
222 * to the UBI volume where 0xFFs mean free space - UBI makes sure this free
223 * space is writable after the update.
224 *
225 * We do not do this for static volumes because they are read-only. But this
226 * also cannot be done because we have to store per-LEB CRC and the correct
227 * data length.
228 *
229 * This function returns zero in case of success and a negative error code in
230 * case of failure.
231 */
232static int write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
233 void *buf, int len, int used_ebs)
234{
235 int err;
236
237 if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
238 int l = ALIGN(len, ubi->min_io_size);
239
240 memset(buf + len, 0xFF, l - len);
241 len = ubi_calc_data_len(ubi, buf, l);
242 if (len == 0) {
243 dbg_gen("all %d bytes contain 0xFF - skip", len);
244 return 0;
245 }
246
247 err = ubi_eba_write_leb(ubi, vol, lnum, buf, 0, len);
248 } else {
249 /*
250 * When writing static volume, and this is the last logical
251 * eraseblock, the length (@len) does not have to be aligned to
252 * the minimal flash I/O unit. The 'ubi_eba_write_leb_st()'
253 * function accepts exact (unaligned) length and stores it in
254 * the VID header. And it takes care of proper alignment by
255 * padding the buffer. Here we just make sure the padding will
256 * contain zeros, not random trash.
257 */
258 memset(buf + len, 0, vol->usable_leb_size - len);
259 err = ubi_eba_write_leb_st(ubi, vol, lnum, buf, len, used_ebs);
260 }
261
262 return err;
263}
264
265/**
266 * ubi_more_update_data - write more update data.
267 * @ubi: UBI device description object
268 * @vol: volume description object
269 * @buf: write data (user-space memory buffer)
270 * @count: how much bytes to write
271 *
272 * This function writes more data to the volume which is being updated. It may
273 * be called arbitrary number of times until all the update data arriveis. This
274 * function returns %0 in case of success, number of bytes written during the
275 * last call if the whole volume update has been successfully finished, and a
276 * negative error code in case of failure.
277 */
278int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
279 const void __user *buf, int count)
280{
281 int lnum, offs, err = 0, len, to_write = count;
282
283 dbg_gen("write %d of %lld bytes, %lld already passed",
284 count, vol->upd_bytes, vol->upd_received);
285
286 if (ubi->ro_mode)
287 return -EROFS;
288
289 lnum = div_u64_rem(vol->upd_received, vol->usable_leb_size, &offs);
290 if (vol->upd_received + count > vol->upd_bytes)
291 to_write = count = vol->upd_bytes - vol->upd_received;
292
293 /*
294 * When updating volumes, we accumulate whole logical eraseblock of
295 * data and write it at once.
296 */
297 if (offs != 0) {
298 /*
299 * This is a write to the middle of the logical eraseblock. We
300 * copy the data to our update buffer and wait for more data or
301 * flush it if the whole eraseblock is written or the update
302 * is finished.
303 */
304
305 len = vol->usable_leb_size - offs;
306 if (len > count)
307 len = count;
308
309 err = copy_from_user(vol->upd_buf + offs, buf, len);
310 if (err)
311 return -EFAULT;
312
313 if (offs + len == vol->usable_leb_size ||
314 vol->upd_received + len == vol->upd_bytes) {
315 int flush_len = offs + len;
316
317 /*
318 * OK, we gathered either the whole eraseblock or this
319 * is the last chunk, it's time to flush the buffer.
320 */
321 ubi_assert(flush_len <= vol->usable_leb_size);
322 err = write_leb(ubi, vol, lnum, vol->upd_buf, flush_len,
323 vol->upd_ebs);
324 if (err)
325 return err;
326 }
327
328 vol->upd_received += len;
329 count -= len;
330 buf += len;
331 lnum += 1;
332 }
333
334 /*
335 * If we've got more to write, let's continue. At this point we know we
336 * are starting from the beginning of an eraseblock.
337 */
338 while (count) {
339 if (count > vol->usable_leb_size)
340 len = vol->usable_leb_size;
341 else
342 len = count;
343
344 err = copy_from_user(vol->upd_buf, buf, len);
345 if (err)
346 return -EFAULT;
347
348 if (len == vol->usable_leb_size ||
349 vol->upd_received + len == vol->upd_bytes) {
350 err = write_leb(ubi, vol, lnum, vol->upd_buf,
351 len, vol->upd_ebs);
352 if (err)
353 break;
354 }
355
356 vol->upd_received += len;
357 count -= len;
358 lnum += 1;
359 buf += len;
360 }
361
362 ubi_assert(vol->upd_received <= vol->upd_bytes);
363 if (vol->upd_received == vol->upd_bytes) {
364 err = ubi_wl_flush(ubi, UBI_ALL, UBI_ALL);
365 if (err)
366 return err;
367 /* The update is finished, clear the update marker */
368 err = clear_update_marker(ubi, vol, vol->upd_bytes);
369 if (err)
370 return err;
371 vol->updating = 0;
372 err = to_write;
373 vfree(vol->upd_buf);
374 }
375
376 return err;
377}
378
379/**
380 * ubi_more_leb_change_data - accept more data for atomic LEB change.
381 * @ubi: UBI device description object
382 * @vol: volume description object
383 * @buf: write data (user-space memory buffer)
384 * @count: how much bytes to write
385 *
386 * This function accepts more data to the volume which is being under the
387 * "atomic LEB change" operation. It may be called arbitrary number of times
388 * until all data arrives. This function returns %0 in case of success, number
389 * of bytes written during the last call if the whole "atomic LEB change"
390 * operation has been successfully finished, and a negative error code in case
391 * of failure.
392 */
393int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
394 const void __user *buf, int count)
395{
396 int err;
397
398 dbg_gen("write %d of %lld bytes, %lld already passed",
399 count, vol->upd_bytes, vol->upd_received);
400
401 if (ubi->ro_mode)
402 return -EROFS;
403
404 if (vol->upd_received + count > vol->upd_bytes)
405 count = vol->upd_bytes - vol->upd_received;
406
407 err = copy_from_user(vol->upd_buf + vol->upd_received, buf, count);
408 if (err)
409 return -EFAULT;
410
411 vol->upd_received += count;
412
413 if (vol->upd_received == vol->upd_bytes) {
414 int len = ALIGN((int)vol->upd_bytes, ubi->min_io_size);
415
416 memset(vol->upd_buf + vol->upd_bytes, 0xFF,
417 len - vol->upd_bytes);
418 len = ubi_calc_data_len(ubi, vol->upd_buf, len);
419 err = ubi_eba_atomic_leb_change(ubi, vol, vol->ch_lnum,
420 vol->upd_buf, len);
421 if (err)
422 return err;
423 }
424
425 ubi_assert(vol->upd_received <= vol->upd_bytes);
426 if (vol->upd_received == vol->upd_bytes) {
427 vol->changing_leb = 0;
428 err = count;
429 vfree(vol->upd_buf);
430 }
431
432 return err;
433}