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1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
801c135c AB |
2 | /* |
3 | * Copyright (c) International Business Machines Corp., 2006 | |
4 | * Copyright (c) Nokia Corporation, 2006 | |
5 | * | |
801c135c AB |
6 | * Author: Artem Bityutskiy (Битюцкий Артём) |
7 | * | |
8 | * Jan 2007: Alexander Schmidt, hacked per-volume update. | |
9 | */ | |
10 | ||
11 | /* | |
e653879c AB |
12 | * This file contains implementation of the volume update and atomic LEB change |
13 | * functionality. | |
801c135c AB |
14 | * |
15 | * The update operation is based on the per-volume update marker which is | |
16 | * stored in the volume table. The update marker is set before the update | |
17 | * starts, and removed after the update has been finished. So if the update was | |
18 | * interrupted by an unclean re-boot or due to some other reasons, the update | |
19 | * marker stays on the flash media and UBI finds it when it attaches the MTD | |
20 | * device next time. If the update marker is set for a volume, the volume is | |
21 | * treated as damaged and most I/O operations are prohibited. Only a new update | |
22 | * operation is allowed. | |
23 | * | |
24 | * Note, in general it is possible to implement the update operation as a | |
25 | * transaction with a roll-back capability. | |
26 | */ | |
27 | ||
28 | #include <linux/err.h> | |
9c9ec147 | 29 | #include <linux/uaccess.h> |
3013ee31 | 30 | #include <linux/math64.h> |
801c135c AB |
31 | #include "ubi.h" |
32 | ||
33 | /** | |
34 | * set_update_marker - set update marker. | |
35 | * @ubi: UBI device description object | |
1b68d0ee | 36 | * @vol: volume description object |
801c135c | 37 | * |
1b68d0ee | 38 | * This function sets the update marker flag for volume @vol. Returns zero |
801c135c AB |
39 | * in case of success and a negative error code in case of failure. |
40 | */ | |
1b68d0ee | 41 | static int set_update_marker(struct ubi_device *ubi, struct ubi_volume *vol) |
801c135c AB |
42 | { |
43 | int err; | |
44 | struct ubi_vtbl_record vtbl_rec; | |
801c135c | 45 | |
c8566350 | 46 | dbg_gen("set update marker for volume %d", vol->vol_id); |
801c135c AB |
47 | |
48 | if (vol->upd_marker) { | |
1b68d0ee | 49 | ubi_assert(ubi->vtbl[vol->vol_id].upd_marker); |
c8566350 | 50 | dbg_gen("already set"); |
801c135c AB |
51 | return 0; |
52 | } | |
53 | ||
d856c13c | 54 | vtbl_rec = ubi->vtbl[vol->vol_id]; |
801c135c AB |
55 | vtbl_rec.upd_marker = 1; |
56 | ||
f089c0b2 | 57 | mutex_lock(&ubi->device_mutex); |
1b68d0ee | 58 | err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec); |
801c135c | 59 | vol->upd_marker = 1; |
95c9c1da | 60 | mutex_unlock(&ubi->device_mutex); |
801c135c AB |
61 | return err; |
62 | } | |
63 | ||
64 | /** | |
65 | * clear_update_marker - clear update marker. | |
66 | * @ubi: UBI device description object | |
1b68d0ee | 67 | * @vol: volume description object |
801c135c AB |
68 | * @bytes: new data size in bytes |
69 | * | |
1b68d0ee | 70 | * This function clears the update marker for volume @vol, sets new volume |
801c135c AB |
71 | * data size and clears the "corrupted" flag (static volumes only). Returns |
72 | * zero in case of success and a negative error code in case of failure. | |
73 | */ | |
1b68d0ee AB |
74 | static int clear_update_marker(struct ubi_device *ubi, struct ubi_volume *vol, |
75 | long long bytes) | |
801c135c AB |
76 | { |
77 | int err; | |
801c135c | 78 | struct ubi_vtbl_record vtbl_rec; |
801c135c | 79 | |
c8566350 | 80 | dbg_gen("clear update marker for volume %d", vol->vol_id); |
801c135c | 81 | |
d856c13c | 82 | vtbl_rec = ubi->vtbl[vol->vol_id]; |
801c135c AB |
83 | ubi_assert(vol->upd_marker && vtbl_rec.upd_marker); |
84 | vtbl_rec.upd_marker = 0; | |
85 | ||
86 | if (vol->vol_type == UBI_STATIC_VOLUME) { | |
87 | vol->corrupted = 0; | |
3013ee31 AB |
88 | vol->used_bytes = bytes; |
89 | vol->used_ebs = div_u64_rem(bytes, vol->usable_leb_size, | |
90 | &vol->last_eb_bytes); | |
801c135c AB |
91 | if (vol->last_eb_bytes) |
92 | vol->used_ebs += 1; | |
93 | else | |
94 | vol->last_eb_bytes = vol->usable_leb_size; | |
95 | } | |
96 | ||
f089c0b2 | 97 | mutex_lock(&ubi->device_mutex); |
1b68d0ee | 98 | err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec); |
801c135c | 99 | vol->upd_marker = 0; |
95c9c1da | 100 | mutex_unlock(&ubi->device_mutex); |
801c135c AB |
101 | return err; |
102 | } | |
103 | ||
104 | /** | |
105 | * ubi_start_update - start volume update. | |
106 | * @ubi: UBI device description object | |
1b68d0ee | 107 | * @vol: volume description object |
801c135c AB |
108 | * @bytes: update bytes |
109 | * | |
110 | * This function starts volume update operation. If @bytes is zero, the volume | |
111 | * is just wiped out. Returns zero in case of success and a negative error code | |
112 | * in case of failure. | |
113 | */ | |
1b68d0ee AB |
114 | int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol, |
115 | long long bytes) | |
801c135c AB |
116 | { |
117 | int i, err; | |
801c135c | 118 | |
c8566350 | 119 | dbg_gen("start update of volume %d, %llu bytes", vol->vol_id, bytes); |
e653879c | 120 | ubi_assert(!vol->updating && !vol->changing_leb); |
801c135c AB |
121 | vol->updating = 1; |
122 | ||
f38aed97 RW |
123 | vol->upd_buf = vmalloc(ubi->leb_size); |
124 | if (!vol->upd_buf) | |
125 | return -ENOMEM; | |
126 | ||
1b68d0ee | 127 | err = set_update_marker(ubi, vol); |
801c135c AB |
128 | if (err) |
129 | return err; | |
130 | ||
131 | /* Before updating - wipe out the volume */ | |
132 | for (i = 0; i < vol->reserved_pebs; i++) { | |
89b96b69 | 133 | err = ubi_eba_unmap_leb(ubi, vol, i); |
801c135c AB |
134 | if (err) |
135 | return err; | |
136 | } | |
137 | ||
9cd9a21c SS |
138 | err = ubi_wl_flush(ubi, UBI_ALL, UBI_ALL); |
139 | if (err) | |
140 | return err; | |
6afaf8a4 | 141 | |
9cd9a21c | 142 | if (bytes == 0) { |
1b68d0ee | 143 | err = clear_update_marker(ubi, vol, 0); |
801c135c AB |
144 | if (err) |
145 | return err; | |
f38aed97 RW |
146 | |
147 | vfree(vol->upd_buf); | |
6afaf8a4 | 148 | vol->updating = 0; |
ebddd63b | 149 | return 0; |
801c135c AB |
150 | } |
151 | ||
3013ee31 AB |
152 | vol->upd_ebs = div_u64(bytes + vol->usable_leb_size - 1, |
153 | vol->usable_leb_size); | |
801c135c AB |
154 | vol->upd_bytes = bytes; |
155 | vol->upd_received = 0; | |
156 | return 0; | |
157 | } | |
158 | ||
e653879c AB |
159 | /** |
160 | * ubi_start_leb_change - start atomic LEB change. | |
161 | * @ubi: UBI device description object | |
162 | * @vol: volume description object | |
163 | * @req: operation request | |
164 | * | |
165 | * This function starts atomic LEB change operation. Returns zero in case of | |
166 | * success and a negative error code in case of failure. | |
167 | */ | |
168 | int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol, | |
169 | const struct ubi_leb_change_req *req) | |
170 | { | |
171 | ubi_assert(!vol->updating && !vol->changing_leb); | |
172 | ||
c8566350 | 173 | dbg_gen("start changing LEB %d:%d, %u bytes", |
e653879c AB |
174 | vol->vol_id, req->lnum, req->bytes); |
175 | if (req->bytes == 0) | |
b36a261e | 176 | return ubi_eba_atomic_leb_change(ubi, vol, req->lnum, NULL, 0); |
e653879c AB |
177 | |
178 | vol->upd_bytes = req->bytes; | |
179 | vol->upd_received = 0; | |
180 | vol->changing_leb = 1; | |
181 | vol->ch_lnum = req->lnum; | |
e653879c | 182 | |
e4f6daac | 183 | vol->upd_buf = vmalloc(ALIGN((int)req->bytes, ubi->min_io_size)); |
e653879c AB |
184 | if (!vol->upd_buf) |
185 | return -ENOMEM; | |
186 | ||
187 | return 0; | |
188 | } | |
189 | ||
801c135c AB |
190 | /** |
191 | * write_leb - write update data. | |
192 | * @ubi: UBI device description object | |
1b68d0ee | 193 | * @vol: volume description object |
801c135c AB |
194 | * @lnum: logical eraseblock number |
195 | * @buf: data to write | |
196 | * @len: data size | |
197 | * @used_ebs: how many logical eraseblocks will this volume contain (static | |
198 | * volumes only) | |
199 | * | |
200 | * This function writes update data to corresponding logical eraseblock. In | |
201 | * case of dynamic volume, this function checks if the data contains 0xFF bytes | |
202 | * at the end. If yes, the 0xFF bytes are cut and not written. So if the whole | |
203 | * buffer contains only 0xFF bytes, the LEB is left unmapped. | |
204 | * | |
205 | * The reason why we skip the trailing 0xFF bytes in case of dynamic volume is | |
206 | * that we want to make sure that more data may be appended to the logical | |
207 | * eraseblock in future. Indeed, writing 0xFF bytes may have side effects and | |
208 | * this PEB won't be writable anymore. So if one writes the file-system image | |
209 | * to the UBI volume where 0xFFs mean free space - UBI makes sure this free | |
210 | * space is writable after the update. | |
211 | * | |
212 | * We do not do this for static volumes because they are read-only. But this | |
213 | * also cannot be done because we have to store per-LEB CRC and the correct | |
214 | * data length. | |
215 | * | |
216 | * This function returns zero in case of success and a negative error code in | |
217 | * case of failure. | |
218 | */ | |
1b68d0ee AB |
219 | static int write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum, |
220 | void *buf, int len, int used_ebs) | |
801c135c | 221 | { |
e653879c | 222 | int err; |
801c135c AB |
223 | |
224 | if (vol->vol_type == UBI_DYNAMIC_VOLUME) { | |
a0fd1efd | 225 | int l = ALIGN(len, ubi->min_io_size); |
801c135c | 226 | |
a0fd1efd KP |
227 | memset(buf + len, 0xFF, l - len); |
228 | len = ubi_calc_data_len(ubi, buf, l); | |
e653879c | 229 | if (len == 0) { |
c8566350 | 230 | dbg_gen("all %d bytes contain 0xFF - skip", len); |
801c135c AB |
231 | return 0; |
232 | } | |
801c135c | 233 | |
b36a261e | 234 | err = ubi_eba_write_leb(ubi, vol, lnum, buf, 0, len); |
801c135c AB |
235 | } else { |
236 | /* | |
237 | * When writing static volume, and this is the last logical | |
238 | * eraseblock, the length (@len) does not have to be aligned to | |
239 | * the minimal flash I/O unit. The 'ubi_eba_write_leb_st()' | |
240 | * function accepts exact (unaligned) length and stores it in | |
241 | * the VID header. And it takes care of proper alignment by | |
242 | * padding the buffer. Here we just make sure the padding will | |
243 | * contain zeros, not random trash. | |
244 | */ | |
245 | memset(buf + len, 0, vol->usable_leb_size - len); | |
b36a261e | 246 | err = ubi_eba_write_leb_st(ubi, vol, lnum, buf, len, used_ebs); |
801c135c AB |
247 | } |
248 | ||
249 | return err; | |
250 | } | |
251 | ||
252 | /** | |
253 | * ubi_more_update_data - write more update data. | |
ebaaf1af | 254 | * @ubi: UBI device description object |
801c135c AB |
255 | * @vol: volume description object |
256 | * @buf: write data (user-space memory buffer) | |
257 | * @count: how much bytes to write | |
258 | * | |
259 | * This function writes more data to the volume which is being updated. It may | |
e653879c AB |
260 | * be called arbitrary number of times until all the update data arriveis. This |
261 | * function returns %0 in case of success, number of bytes written during the | |
262 | * last call if the whole volume update has been successfully finished, and a | |
801c135c AB |
263 | * negative error code in case of failure. |
264 | */ | |
1b68d0ee | 265 | int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol, |
801c135c AB |
266 | const void __user *buf, int count) |
267 | { | |
801c135c AB |
268 | int lnum, offs, err = 0, len, to_write = count; |
269 | ||
c8566350 | 270 | dbg_gen("write %d of %lld bytes, %lld already passed", |
801c135c AB |
271 | count, vol->upd_bytes, vol->upd_received); |
272 | ||
273 | if (ubi->ro_mode) | |
274 | return -EROFS; | |
275 | ||
3013ee31 | 276 | lnum = div_u64_rem(vol->upd_received, vol->usable_leb_size, &offs); |
801c135c AB |
277 | if (vol->upd_received + count > vol->upd_bytes) |
278 | to_write = count = vol->upd_bytes - vol->upd_received; | |
279 | ||
280 | /* | |
281 | * When updating volumes, we accumulate whole logical eraseblock of | |
282 | * data and write it at once. | |
283 | */ | |
284 | if (offs != 0) { | |
285 | /* | |
286 | * This is a write to the middle of the logical eraseblock. We | |
287 | * copy the data to our update buffer and wait for more data or | |
288 | * flush it if the whole eraseblock is written or the update | |
289 | * is finished. | |
290 | */ | |
291 | ||
292 | len = vol->usable_leb_size - offs; | |
293 | if (len > count) | |
294 | len = count; | |
295 | ||
296 | err = copy_from_user(vol->upd_buf + offs, buf, len); | |
297 | if (err) | |
298 | return -EFAULT; | |
299 | ||
300 | if (offs + len == vol->usable_leb_size || | |
301 | vol->upd_received + len == vol->upd_bytes) { | |
302 | int flush_len = offs + len; | |
303 | ||
304 | /* | |
305 | * OK, we gathered either the whole eraseblock or this | |
306 | * is the last chunk, it's time to flush the buffer. | |
307 | */ | |
308 | ubi_assert(flush_len <= vol->usable_leb_size); | |
1b68d0ee AB |
309 | err = write_leb(ubi, vol, lnum, vol->upd_buf, flush_len, |
310 | vol->upd_ebs); | |
801c135c AB |
311 | if (err) |
312 | return err; | |
313 | } | |
314 | ||
315 | vol->upd_received += len; | |
316 | count -= len; | |
317 | buf += len; | |
318 | lnum += 1; | |
319 | } | |
320 | ||
321 | /* | |
322 | * If we've got more to write, let's continue. At this point we know we | |
323 | * are starting from the beginning of an eraseblock. | |
324 | */ | |
325 | while (count) { | |
326 | if (count > vol->usable_leb_size) | |
327 | len = vol->usable_leb_size; | |
328 | else | |
329 | len = count; | |
330 | ||
331 | err = copy_from_user(vol->upd_buf, buf, len); | |
332 | if (err) | |
333 | return -EFAULT; | |
334 | ||
335 | if (len == vol->usable_leb_size || | |
336 | vol->upd_received + len == vol->upd_bytes) { | |
1b68d0ee AB |
337 | err = write_leb(ubi, vol, lnum, vol->upd_buf, |
338 | len, vol->upd_ebs); | |
801c135c AB |
339 | if (err) |
340 | break; | |
341 | } | |
342 | ||
343 | vol->upd_received += len; | |
344 | count -= len; | |
345 | lnum += 1; | |
346 | buf += len; | |
347 | } | |
348 | ||
349 | ubi_assert(vol->upd_received <= vol->upd_bytes); | |
350 | if (vol->upd_received == vol->upd_bytes) { | |
62f38455 | 351 | err = ubi_wl_flush(ubi, UBI_ALL, UBI_ALL); |
6afaf8a4 SAS |
352 | if (err) |
353 | return err; | |
801c135c | 354 | /* The update is finished, clear the update marker */ |
1b68d0ee | 355 | err = clear_update_marker(ubi, vol, vol->upd_bytes); |
801c135c AB |
356 | if (err) |
357 | return err; | |
6afaf8a4 SAS |
358 | vol->updating = 0; |
359 | err = to_write; | |
360 | vfree(vol->upd_buf); | |
801c135c AB |
361 | } |
362 | ||
363 | return err; | |
364 | } | |
e653879c AB |
365 | |
366 | /** | |
367 | * ubi_more_leb_change_data - accept more data for atomic LEB change. | |
ebaaf1af | 368 | * @ubi: UBI device description object |
e653879c AB |
369 | * @vol: volume description object |
370 | * @buf: write data (user-space memory buffer) | |
371 | * @count: how much bytes to write | |
372 | * | |
373 | * This function accepts more data to the volume which is being under the | |
374 | * "atomic LEB change" operation. It may be called arbitrary number of times | |
375 | * until all data arrives. This function returns %0 in case of success, number | |
376 | * of bytes written during the last call if the whole "atomic LEB change" | |
377 | * operation has been successfully finished, and a negative error code in case | |
378 | * of failure. | |
379 | */ | |
380 | int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol, | |
381 | const void __user *buf, int count) | |
382 | { | |
383 | int err; | |
384 | ||
c8566350 | 385 | dbg_gen("write %d of %lld bytes, %lld already passed", |
e653879c AB |
386 | count, vol->upd_bytes, vol->upd_received); |
387 | ||
388 | if (ubi->ro_mode) | |
389 | return -EROFS; | |
390 | ||
391 | if (vol->upd_received + count > vol->upd_bytes) | |
392 | count = vol->upd_bytes - vol->upd_received; | |
393 | ||
394 | err = copy_from_user(vol->upd_buf + vol->upd_received, buf, count); | |
395 | if (err) | |
396 | return -EFAULT; | |
397 | ||
398 | vol->upd_received += count; | |
399 | ||
400 | if (vol->upd_received == vol->upd_bytes) { | |
401 | int len = ALIGN((int)vol->upd_bytes, ubi->min_io_size); | |
402 | ||
9c9ec147 AB |
403 | memset(vol->upd_buf + vol->upd_bytes, 0xFF, |
404 | len - vol->upd_bytes); | |
e653879c AB |
405 | len = ubi_calc_data_len(ubi, vol->upd_buf, len); |
406 | err = ubi_eba_atomic_leb_change(ubi, vol, vol->ch_lnum, | |
b36a261e | 407 | vol->upd_buf, len); |
e653879c AB |
408 | if (err) |
409 | return err; | |
410 | } | |
411 | ||
412 | ubi_assert(vol->upd_received <= vol->upd_bytes); | |
413 | if (vol->upd_received == vol->upd_bytes) { | |
414 | vol->changing_leb = 0; | |
415 | err = count; | |
416 | vfree(vol->upd_buf); | |
417 | } | |
418 | ||
419 | return err; | |
420 | } |