2 * Copyright (c) International Business Machines Corp., 2006
3 * Copyright (c) Nokia Corporation, 2006, 2007
4 * SPDX-License-Identifier: GPL-2.0+
6 * Author: Artem Bityutskiy (Битюцкий Артём)
10 * UBI input/output sub-system.
12 * This sub-system provides a uniform way to work with all kinds of the
13 * underlying MTD devices. It also implements handy functions for reading and
14 * writing UBI headers.
16 * We are trying to have a paranoid mindset and not to trust to what we read
17 * from the flash media in order to be more secure and robust. So this
18 * sub-system validates every single header it reads from the flash media.
20 * Some words about how the eraseblock headers are stored.
22 * The erase counter header is always stored at offset zero. By default, the
23 * VID header is stored after the EC header at the closest aligned offset
24 * (i.e. aligned to the minimum I/O unit size). Data starts next to the VID
25 * header at the closest aligned offset. But this default layout may be
26 * changed. For example, for different reasons (e.g., optimization) UBI may be
27 * asked to put the VID header at further offset, and even at an unaligned
28 * offset. Of course, if the offset of the VID header is unaligned, UBI adds
29 * proper padding in front of it. Data offset may also be changed but it has to
32 * About minimal I/O units. In general, UBI assumes flash device model where
33 * there is only one minimal I/O unit size. E.g., in case of NOR flash it is 1,
34 * in case of NAND flash it is a NAND page, etc. This is reported by MTD in the
35 * @ubi->mtd->writesize field. But as an exception, UBI admits of using another
36 * (smaller) minimal I/O unit size for EC and VID headers to make it possible
37 * to do different optimizations.
39 * This is extremely useful in case of NAND flashes which admit of several
40 * write operations to one NAND page. In this case UBI can fit EC and VID
41 * headers at one NAND page. Thus, UBI may use "sub-page" size as the minimal
42 * I/O unit for the headers (the @ubi->hdrs_min_io_size field). But it still
43 * reports NAND page size (@ubi->min_io_size) as a minimal I/O unit for the UBI
46 * Example: some Samsung NANDs with 2KiB pages allow 4x 512-byte writes, so
47 * although the minimal I/O unit is 2K, UBI uses 512 bytes for EC and VID
50 * Q: why not just to treat sub-page as a minimal I/O unit of this flash
51 * device, e.g., make @ubi->min_io_size = 512 in the example above?
53 * A: because when writing a sub-page, MTD still writes a full 2K page but the
54 * bytes which are not relevant to the sub-page are 0xFF. So, basically,
55 * writing 4x512 sub-pages is 4 times slower than writing one 2KiB NAND page.
56 * Thus, we prefer to use sub-pages only for EC and VID headers.
58 * As it was noted above, the VID header may start at a non-aligned offset.
59 * For example, in case of a 2KiB page NAND flash with a 512 bytes sub-page,
60 * the VID header may reside at offset 1984 which is the last 64 bytes of the
61 * last sub-page (EC header is always at offset zero). This causes some
62 * difficulties when reading and writing VID headers.
64 * Suppose we have a 64-byte buffer and we read a VID header at it. We change
65 * the data and want to write this VID header out. As we can only write in
66 * 512-byte chunks, we have to allocate one more buffer and copy our VID header
67 * to offset 448 of this buffer.
69 * The I/O sub-system does the following trick in order to avoid this extra
70 * copy. It always allocates a @ubi->vid_hdr_alsize bytes buffer for the VID
71 * header and returns a pointer to offset @ubi->vid_hdr_shift of this buffer.
72 * When the VID header is being written out, it shifts the VID header pointer
73 * back and writes the whole sub-page.
77 #include <linux/crc32.h>
78 #include <linux/err.h>
79 #include <linux/slab.h>
81 #include <ubi_uboot.h>
86 static int self_check_not_bad(const struct ubi_device *ubi, int pnum);
87 static int self_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum);
88 static int self_check_ec_hdr(const struct ubi_device *ubi, int pnum,
89 const struct ubi_ec_hdr *ec_hdr);
90 static int self_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum);
91 static int self_check_vid_hdr(const struct ubi_device *ubi, int pnum,
92 const struct ubi_vid_hdr *vid_hdr);
93 static int self_check_write(struct ubi_device *ubi, const void *buf, int pnum,
97 * ubi_io_read - read data from a physical eraseblock.
98 * @ubi: UBI device description object
99 * @buf: buffer where to store the read data
100 * @pnum: physical eraseblock number to read from
101 * @offset: offset within the physical eraseblock from where to read
102 * @len: how many bytes to read
104 * This function reads data from offset @offset of physical eraseblock @pnum
105 * and stores the read data in the @buf buffer. The following return codes are
108 * o %0 if all the requested data were successfully read;
109 * o %UBI_IO_BITFLIPS if all the requested data were successfully read, but
110 * correctable bit-flips were detected; this is harmless but may indicate
111 * that this eraseblock may become bad soon (but do not have to);
112 * o %-EBADMSG if the MTD subsystem reported about data integrity problems, for
113 * example it can be an ECC error in case of NAND; this most probably means
114 * that the data is corrupted;
115 * o %-EIO if some I/O error occurred;
116 * o other negative error codes in case of other errors.
118 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
121 int err, retries = 0;
125 dbg_io("read %d bytes from PEB %d:%d", len, pnum, offset);
127 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
128 ubi_assert(offset >= 0 && offset + len <= ubi->peb_size);
131 err = self_check_not_bad(ubi, pnum);
136 * Deliberately corrupt the buffer to improve robustness. Indeed, if we
137 * do not do this, the following may happen:
138 * 1. The buffer contains data from previous operation, e.g., read from
139 * another PEB previously. The data looks like expected, e.g., if we
140 * just do not read anything and return - the caller would not
141 * notice this. E.g., if we are reading a VID header, the buffer may
142 * contain a valid VID header from another PEB.
143 * 2. The driver is buggy and returns us success or -EBADMSG or
144 * -EUCLEAN, but it does not actually put any data to the buffer.
146 * This may confuse UBI or upper layers - they may think the buffer
147 * contains valid data while in fact it is just old data. This is
148 * especially possible because UBI (and UBIFS) relies on CRC, and
149 * treats data as correct even in case of ECC errors if the CRC is
152 * Try to prevent this situation by changing the first byte of the
155 *((uint8_t *)buf) ^= 0xFF;
157 addr = (loff_t)pnum * ubi->peb_size + offset;
159 err = mtd_read(ubi->mtd, addr, len, &read, buf);
161 const char *errstr = mtd_is_eccerr(err) ? " (ECC error)" : "";
163 if (mtd_is_bitflip(err)) {
165 * -EUCLEAN is reported if there was a bit-flip which
166 * was corrected, so this is harmless.
168 * We do not report about it here unless debugging is
169 * enabled. A corresponding message will be printed
170 * later, when it is has been scrubbed.
172 ubi_msg("fixable bit-flip detected at PEB %d", pnum);
173 ubi_assert(len == read);
174 return UBI_IO_BITFLIPS;
177 if (retries++ < UBI_IO_RETRIES) {
178 ubi_warn("error %d%s while reading %d bytes from PEB %d:%d, read only %zd bytes, retry",
179 err, errstr, len, pnum, offset, read);
184 ubi_err("error %d%s while reading %d bytes from PEB %d:%d, read %zd bytes",
185 err, errstr, len, pnum, offset, read);
189 * The driver should never return -EBADMSG if it failed to read
190 * all the requested data. But some buggy drivers might do
191 * this, so we change it to -EIO.
193 if (read != len && mtd_is_eccerr(err)) {
198 ubi_assert(len == read);
200 if (ubi_dbg_is_bitflip(ubi)) {
201 dbg_gen("bit-flip (emulated)");
202 err = UBI_IO_BITFLIPS;
210 * ubi_io_write - write data to a physical eraseblock.
211 * @ubi: UBI device description object
212 * @buf: buffer with the data to write
213 * @pnum: physical eraseblock number to write to
214 * @offset: offset within the physical eraseblock where to write
215 * @len: how many bytes to write
217 * This function writes @len bytes of data from buffer @buf to offset @offset
218 * of physical eraseblock @pnum. If all the data were successfully written,
219 * zero is returned. If an error occurred, this function returns a negative
220 * error code. If %-EIO is returned, the physical eraseblock most probably went
223 * Note, in case of an error, it is possible that something was still written
224 * to the flash media, but may be some garbage.
226 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
233 dbg_io("write %d bytes to PEB %d:%d", len, pnum, offset);
235 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
236 ubi_assert(offset >= 0 && offset + len <= ubi->peb_size);
237 ubi_assert(offset % ubi->hdrs_min_io_size == 0);
238 ubi_assert(len > 0 && len % ubi->hdrs_min_io_size == 0);
241 ubi_err("read-only mode");
245 err = self_check_not_bad(ubi, pnum);
249 /* The area we are writing to has to contain all 0xFF bytes */
250 err = ubi_self_check_all_ff(ubi, pnum, offset, len);
254 if (offset >= ubi->leb_start) {
256 * We write to the data area of the physical eraseblock. Make
257 * sure it has valid EC and VID headers.
259 err = self_check_peb_ec_hdr(ubi, pnum);
262 err = self_check_peb_vid_hdr(ubi, pnum);
267 if (ubi_dbg_is_write_failure(ubi)) {
268 ubi_err("cannot write %d bytes to PEB %d:%d (emulated)",
274 addr = (loff_t)pnum * ubi->peb_size + offset;
275 err = mtd_write(ubi->mtd, addr, len, &written, buf);
277 ubi_err("error %d while writing %d bytes to PEB %d:%d, written %zd bytes",
278 err, len, pnum, offset, written);
280 ubi_dump_flash(ubi, pnum, offset, len);
282 ubi_assert(written == len);
285 err = self_check_write(ubi, buf, pnum, offset, len);
290 * Since we always write sequentially, the rest of the PEB has
291 * to contain only 0xFF bytes.
294 len = ubi->peb_size - offset;
296 err = ubi_self_check_all_ff(ubi, pnum, offset, len);
303 * erase_callback - MTD erasure call-back.
304 * @ei: MTD erase information object.
306 * Note, even though MTD erase interface is asynchronous, all the current
307 * implementations are synchronous anyway.
309 static void erase_callback(struct erase_info *ei)
311 wake_up_interruptible((wait_queue_head_t *)ei->priv);
315 * do_sync_erase - synchronously erase a physical eraseblock.
316 * @ubi: UBI device description object
317 * @pnum: the physical eraseblock number to erase
319 * This function synchronously erases physical eraseblock @pnum and returns
320 * zero in case of success and a negative error code in case of failure. If
321 * %-EIO is returned, the physical eraseblock most probably went bad.
323 static int do_sync_erase(struct ubi_device *ubi, int pnum)
325 int err, retries = 0;
326 struct erase_info ei;
327 wait_queue_head_t wq;
329 dbg_io("erase PEB %d", pnum);
330 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
333 ubi_err("read-only mode");
338 init_waitqueue_head(&wq);
339 memset(&ei, 0, sizeof(struct erase_info));
342 ei.addr = (loff_t)pnum * ubi->peb_size;
343 ei.len = ubi->peb_size;
344 ei.callback = erase_callback;
345 ei.priv = (unsigned long)&wq;
347 err = mtd_erase(ubi->mtd, &ei);
349 if (retries++ < UBI_IO_RETRIES) {
350 ubi_warn("error %d while erasing PEB %d, retry",
355 ubi_err("cannot erase PEB %d, error %d", pnum, err);
360 err = wait_event_interruptible(wq, ei.state == MTD_ERASE_DONE ||
361 ei.state == MTD_ERASE_FAILED);
363 ubi_err("interrupted PEB %d erasure", pnum);
367 if (ei.state == MTD_ERASE_FAILED) {
368 if (retries++ < UBI_IO_RETRIES) {
369 ubi_warn("error while erasing PEB %d, retry", pnum);
373 ubi_err("cannot erase PEB %d", pnum);
378 err = ubi_self_check_all_ff(ubi, pnum, 0, ubi->peb_size);
382 if (ubi_dbg_is_erase_failure(ubi)) {
383 ubi_err("cannot erase PEB %d (emulated)", pnum);
390 /* Patterns to write to a physical eraseblock when torturing it */
391 static uint8_t patterns[] = {0xa5, 0x5a, 0x0};
394 * torture_peb - test a supposedly bad physical eraseblock.
395 * @ubi: UBI device description object
396 * @pnum: the physical eraseblock number to test
398 * This function returns %-EIO if the physical eraseblock did not pass the
399 * test, a positive number of erase operations done if the test was
400 * successfully passed, and other negative error codes in case of other errors.
402 static int torture_peb(struct ubi_device *ubi, int pnum)
404 int err, i, patt_count;
406 ubi_msg("run torture test for PEB %d", pnum);
407 patt_count = ARRAY_SIZE(patterns);
408 ubi_assert(patt_count > 0);
410 mutex_lock(&ubi->buf_mutex);
411 for (i = 0; i < patt_count; i++) {
412 err = do_sync_erase(ubi, pnum);
416 /* Make sure the PEB contains only 0xFF bytes */
417 err = ubi_io_read(ubi, ubi->peb_buf, pnum, 0, ubi->peb_size);
421 err = ubi_check_pattern(ubi->peb_buf, 0xFF, ubi->peb_size);
423 ubi_err("erased PEB %d, but a non-0xFF byte found",
429 /* Write a pattern and check it */
430 memset(ubi->peb_buf, patterns[i], ubi->peb_size);
431 err = ubi_io_write(ubi, ubi->peb_buf, pnum, 0, ubi->peb_size);
435 memset(ubi->peb_buf, ~patterns[i], ubi->peb_size);
436 err = ubi_io_read(ubi, ubi->peb_buf, pnum, 0, ubi->peb_size);
440 err = ubi_check_pattern(ubi->peb_buf, patterns[i],
443 ubi_err("pattern %x checking failed for PEB %d",
451 ubi_msg("PEB %d passed torture test, do not mark it as bad", pnum);
454 mutex_unlock(&ubi->buf_mutex);
455 if (err == UBI_IO_BITFLIPS || mtd_is_eccerr(err)) {
457 * If a bit-flip or data integrity error was detected, the test
458 * has not passed because it happened on a freshly erased
459 * physical eraseblock which means something is wrong with it.
461 ubi_err("read problems on freshly erased PEB %d, must be bad",
469 * nor_erase_prepare - prepare a NOR flash PEB for erasure.
470 * @ubi: UBI device description object
471 * @pnum: physical eraseblock number to prepare
473 * NOR flash, or at least some of them, have peculiar embedded PEB erasure
474 * algorithm: the PEB is first filled with zeroes, then it is erased. And
475 * filling with zeroes starts from the end of the PEB. This was observed with
476 * Spansion S29GL512N NOR flash.
478 * This means that in case of a power cut we may end up with intact data at the
479 * beginning of the PEB, and all zeroes at the end of PEB. In other words, the
480 * EC and VID headers are OK, but a large chunk of data at the end of PEB is
481 * zeroed. This makes UBI mistakenly treat this PEB as used and associate it
482 * with an LEB, which leads to subsequent failures (e.g., UBIFS fails).
484 * This function is called before erasing NOR PEBs and it zeroes out EC and VID
485 * magic numbers in order to invalidate them and prevent the failures. Returns
486 * zero in case of success and a negative error code in case of failure.
488 static int nor_erase_prepare(struct ubi_device *ubi, int pnum)
494 struct ubi_ec_hdr ec_hdr;
497 * Note, we cannot generally define VID header buffers on stack,
498 * because of the way we deal with these buffers (see the header
499 * comment in this file). But we know this is a NOR-specific piece of
500 * code, so we can do this. But yes, this is error-prone and we should
501 * (pre-)allocate VID header buffer instead.
503 struct ubi_vid_hdr vid_hdr;
506 * If VID or EC is valid, we have to corrupt them before erasing.
507 * It is important to first invalidate the EC header, and then the VID
508 * header. Otherwise a power cut may lead to valid EC header and
509 * invalid VID header, in which case UBI will treat this PEB as
510 * corrupted and will try to preserve it, and print scary warnings.
512 addr = (loff_t)pnum * ubi->peb_size;
513 err = ubi_io_read_ec_hdr(ubi, pnum, &ec_hdr, 0);
514 if (err != UBI_IO_BAD_HDR_EBADMSG && err != UBI_IO_BAD_HDR &&
516 err = mtd_write(ubi->mtd, addr, 4, &written, (void *)&data);
521 err = ubi_io_read_vid_hdr(ubi, pnum, &vid_hdr, 0);
522 if (err != UBI_IO_BAD_HDR_EBADMSG && err != UBI_IO_BAD_HDR &&
524 addr += ubi->vid_hdr_aloffset;
525 err = mtd_write(ubi->mtd, addr, 4, &written, (void *)&data);
533 * The PEB contains a valid VID or EC header, but we cannot invalidate
534 * it. Supposedly the flash media or the driver is screwed up, so
537 ubi_err("cannot invalidate PEB %d, write returned %d", pnum, err);
538 ubi_dump_flash(ubi, pnum, 0, ubi->peb_size);
543 * ubi_io_sync_erase - synchronously erase a physical eraseblock.
544 * @ubi: UBI device description object
545 * @pnum: physical eraseblock number to erase
546 * @torture: if this physical eraseblock has to be tortured
548 * This function synchronously erases physical eraseblock @pnum. If @torture
549 * flag is not zero, the physical eraseblock is checked by means of writing
550 * different patterns to it and reading them back. If the torturing is enabled,
551 * the physical eraseblock is erased more than once.
553 * This function returns the number of erasures made in case of success, %-EIO
554 * if the erasure failed or the torturing test failed, and other negative error
555 * codes in case of other errors. Note, %-EIO means that the physical
558 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture)
562 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
564 err = self_check_not_bad(ubi, pnum);
569 ubi_err("read-only mode");
573 if (ubi->nor_flash) {
574 err = nor_erase_prepare(ubi, pnum);
580 ret = torture_peb(ubi, pnum);
585 err = do_sync_erase(ubi, pnum);
593 * ubi_io_is_bad - check if a physical eraseblock is bad.
594 * @ubi: UBI device description object
595 * @pnum: the physical eraseblock number to check
597 * This function returns a positive number if the physical eraseblock is bad,
598 * zero if not, and a negative error code if an error occurred.
600 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum)
602 struct mtd_info *mtd = ubi->mtd;
604 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
606 if (ubi->bad_allowed) {
609 ret = mtd_block_isbad(mtd, (loff_t)pnum * ubi->peb_size);
611 ubi_err("error %d while checking if PEB %d is bad",
614 dbg_io("PEB %d is bad", pnum);
622 * ubi_io_mark_bad - mark a physical eraseblock as bad.
623 * @ubi: UBI device description object
624 * @pnum: the physical eraseblock number to mark
626 * This function returns zero in case of success and a negative error code in
629 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum)
632 struct mtd_info *mtd = ubi->mtd;
634 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
637 ubi_err("read-only mode");
641 if (!ubi->bad_allowed)
644 err = mtd_block_markbad(mtd, (loff_t)pnum * ubi->peb_size);
646 ubi_err("cannot mark PEB %d bad, error %d", pnum, err);
651 * validate_ec_hdr - validate an erase counter header.
652 * @ubi: UBI device description object
653 * @ec_hdr: the erase counter header to check
655 * This function returns zero if the erase counter header is OK, and %1 if
658 static int validate_ec_hdr(const struct ubi_device *ubi,
659 const struct ubi_ec_hdr *ec_hdr)
662 int vid_hdr_offset, leb_start;
664 ec = be64_to_cpu(ec_hdr->ec);
665 vid_hdr_offset = be32_to_cpu(ec_hdr->vid_hdr_offset);
666 leb_start = be32_to_cpu(ec_hdr->data_offset);
668 if (ec_hdr->version != UBI_VERSION) {
669 ubi_err("node with incompatible UBI version found: this UBI version is %d, image version is %d",
670 UBI_VERSION, (int)ec_hdr->version);
674 if (vid_hdr_offset != ubi->vid_hdr_offset) {
675 ubi_err("bad VID header offset %d, expected %d",
676 vid_hdr_offset, ubi->vid_hdr_offset);
680 if (leb_start != ubi->leb_start) {
681 ubi_err("bad data offset %d, expected %d",
682 leb_start, ubi->leb_start);
686 if (ec < 0 || ec > UBI_MAX_ERASECOUNTER) {
687 ubi_err("bad erase counter %lld", ec);
694 ubi_err("bad EC header");
695 ubi_dump_ec_hdr(ec_hdr);
701 * ubi_io_read_ec_hdr - read and check an erase counter header.
702 * @ubi: UBI device description object
703 * @pnum: physical eraseblock to read from
704 * @ec_hdr: a &struct ubi_ec_hdr object where to store the read erase counter
706 * @verbose: be verbose if the header is corrupted or was not found
708 * This function reads erase counter header from physical eraseblock @pnum and
709 * stores it in @ec_hdr. This function also checks CRC checksum of the read
710 * erase counter header. The following codes may be returned:
712 * o %0 if the CRC checksum is correct and the header was successfully read;
713 * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected
714 * and corrected by the flash driver; this is harmless but may indicate that
715 * this eraseblock may become bad soon (but may be not);
716 * o %UBI_IO_BAD_HDR if the erase counter header is corrupted (a CRC error);
717 * o %UBI_IO_BAD_HDR_EBADMSG is the same as %UBI_IO_BAD_HDR, but there also was
718 * a data integrity error (uncorrectable ECC error in case of NAND);
719 * o %UBI_IO_FF if only 0xFF bytes were read (the PEB is supposedly empty)
720 * o a negative error code in case of failure.
722 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
723 struct ubi_ec_hdr *ec_hdr, int verbose)
726 uint32_t crc, magic, hdr_crc;
728 dbg_io("read EC header from PEB %d", pnum);
729 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
731 read_err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
733 if (read_err != UBI_IO_BITFLIPS && !mtd_is_eccerr(read_err))
737 * We read all the data, but either a correctable bit-flip
738 * occurred, or MTD reported a data integrity error
739 * (uncorrectable ECC error in case of NAND). The former is
740 * harmless, the later may mean that the read data is
741 * corrupted. But we have a CRC check-sum and we will detect
742 * this. If the EC header is still OK, we just report this as
743 * there was a bit-flip, to force scrubbing.
747 magic = be32_to_cpu(ec_hdr->magic);
748 if (magic != UBI_EC_HDR_MAGIC) {
749 if (mtd_is_eccerr(read_err))
750 return UBI_IO_BAD_HDR_EBADMSG;
753 * The magic field is wrong. Let's check if we have read all
754 * 0xFF. If yes, this physical eraseblock is assumed to be
757 if (ubi_check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) {
758 /* The physical eraseblock is supposedly empty */
760 ubi_warn("no EC header found at PEB %d, only 0xFF bytes",
762 dbg_bld("no EC header found at PEB %d, only 0xFF bytes",
767 return UBI_IO_FF_BITFLIPS;
771 * This is not a valid erase counter header, and these are not
772 * 0xFF bytes. Report that the header is corrupted.
775 ubi_warn("bad magic number at PEB %d: %08x instead of %08x",
776 pnum, magic, UBI_EC_HDR_MAGIC);
777 ubi_dump_ec_hdr(ec_hdr);
779 dbg_bld("bad magic number at PEB %d: %08x instead of %08x",
780 pnum, magic, UBI_EC_HDR_MAGIC);
781 return UBI_IO_BAD_HDR;
784 crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
785 hdr_crc = be32_to_cpu(ec_hdr->hdr_crc);
787 if (hdr_crc != crc) {
789 ubi_warn("bad EC header CRC at PEB %d, calculated %#08x, read %#08x",
791 ubi_dump_ec_hdr(ec_hdr);
793 dbg_bld("bad EC header CRC at PEB %d, calculated %#08x, read %#08x",
797 return UBI_IO_BAD_HDR;
799 return UBI_IO_BAD_HDR_EBADMSG;
802 /* And of course validate what has just been read from the media */
803 err = validate_ec_hdr(ubi, ec_hdr);
805 ubi_err("validation failed for PEB %d", pnum);
810 * If there was %-EBADMSG, but the header CRC is still OK, report about
811 * a bit-flip to force scrubbing on this PEB.
813 return read_err ? UBI_IO_BITFLIPS : 0;
817 * ubi_io_write_ec_hdr - write an erase counter header.
818 * @ubi: UBI device description object
819 * @pnum: physical eraseblock to write to
820 * @ec_hdr: the erase counter header to write
822 * This function writes erase counter header described by @ec_hdr to physical
823 * eraseblock @pnum. It also fills most fields of @ec_hdr before writing, so
824 * the caller do not have to fill them. Callers must only fill the @ec_hdr->ec
827 * This function returns zero in case of success and a negative error code in
828 * case of failure. If %-EIO is returned, the physical eraseblock most probably
831 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
832 struct ubi_ec_hdr *ec_hdr)
837 dbg_io("write EC header to PEB %d", pnum);
838 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
840 ec_hdr->magic = cpu_to_be32(UBI_EC_HDR_MAGIC);
841 ec_hdr->version = UBI_VERSION;
842 ec_hdr->vid_hdr_offset = cpu_to_be32(ubi->vid_hdr_offset);
843 ec_hdr->data_offset = cpu_to_be32(ubi->leb_start);
844 ec_hdr->image_seq = cpu_to_be32(ubi->image_seq);
845 crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
846 ec_hdr->hdr_crc = cpu_to_be32(crc);
848 err = self_check_ec_hdr(ubi, pnum, ec_hdr);
852 err = ubi_io_write(ubi, ec_hdr, pnum, 0, ubi->ec_hdr_alsize);
857 * validate_vid_hdr - validate a volume identifier header.
858 * @ubi: UBI device description object
859 * @vid_hdr: the volume identifier header to check
861 * This function checks that data stored in the volume identifier header
862 * @vid_hdr. Returns zero if the VID header is OK and %1 if not.
864 static int validate_vid_hdr(const struct ubi_device *ubi,
865 const struct ubi_vid_hdr *vid_hdr)
867 int vol_type = vid_hdr->vol_type;
868 int copy_flag = vid_hdr->copy_flag;
869 int vol_id = be32_to_cpu(vid_hdr->vol_id);
870 int lnum = be32_to_cpu(vid_hdr->lnum);
871 int compat = vid_hdr->compat;
872 int data_size = be32_to_cpu(vid_hdr->data_size);
873 int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
874 int data_pad = be32_to_cpu(vid_hdr->data_pad);
875 int data_crc = be32_to_cpu(vid_hdr->data_crc);
876 int usable_leb_size = ubi->leb_size - data_pad;
878 if (copy_flag != 0 && copy_flag != 1) {
879 ubi_err("bad copy_flag");
883 if (vol_id < 0 || lnum < 0 || data_size < 0 || used_ebs < 0 ||
885 ubi_err("negative values");
889 if (vol_id >= UBI_MAX_VOLUMES && vol_id < UBI_INTERNAL_VOL_START) {
890 ubi_err("bad vol_id");
894 if (vol_id < UBI_INTERNAL_VOL_START && compat != 0) {
895 ubi_err("bad compat");
899 if (vol_id >= UBI_INTERNAL_VOL_START && compat != UBI_COMPAT_DELETE &&
900 compat != UBI_COMPAT_RO && compat != UBI_COMPAT_PRESERVE &&
901 compat != UBI_COMPAT_REJECT) {
902 ubi_err("bad compat");
906 if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) {
907 ubi_err("bad vol_type");
911 if (data_pad >= ubi->leb_size / 2) {
912 ubi_err("bad data_pad");
916 if (vol_type == UBI_VID_STATIC) {
918 * Although from high-level point of view static volumes may
919 * contain zero bytes of data, but no VID headers can contain
920 * zero at these fields, because they empty volumes do not have
921 * mapped logical eraseblocks.
924 ubi_err("zero used_ebs");
927 if (data_size == 0) {
928 ubi_err("zero data_size");
931 if (lnum < used_ebs - 1) {
932 if (data_size != usable_leb_size) {
933 ubi_err("bad data_size");
936 } else if (lnum == used_ebs - 1) {
937 if (data_size == 0) {
938 ubi_err("bad data_size at last LEB");
942 ubi_err("too high lnum");
946 if (copy_flag == 0) {
948 ubi_err("non-zero data CRC");
951 if (data_size != 0) {
952 ubi_err("non-zero data_size");
956 if (data_size == 0) {
957 ubi_err("zero data_size of copy");
962 ubi_err("bad used_ebs");
970 ubi_err("bad VID header");
971 ubi_dump_vid_hdr(vid_hdr);
977 * ubi_io_read_vid_hdr - read and check a volume identifier header.
978 * @ubi: UBI device description object
979 * @pnum: physical eraseblock number to read from
980 * @vid_hdr: &struct ubi_vid_hdr object where to store the read volume
982 * @verbose: be verbose if the header is corrupted or wasn't found
984 * This function reads the volume identifier header from physical eraseblock
985 * @pnum and stores it in @vid_hdr. It also checks CRC checksum of the read
986 * volume identifier header. The error codes are the same as in
987 * 'ubi_io_read_ec_hdr()'.
989 * Note, the implementation of this function is also very similar to
990 * 'ubi_io_read_ec_hdr()', so refer commentaries in 'ubi_io_read_ec_hdr()'.
992 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
993 struct ubi_vid_hdr *vid_hdr, int verbose)
996 uint32_t crc, magic, hdr_crc;
999 dbg_io("read VID header from PEB %d", pnum);
1000 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
1002 p = (char *)vid_hdr - ubi->vid_hdr_shift;
1003 read_err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
1004 ubi->vid_hdr_alsize);
1005 if (read_err && read_err != UBI_IO_BITFLIPS && !mtd_is_eccerr(read_err))
1008 magic = be32_to_cpu(vid_hdr->magic);
1009 if (magic != UBI_VID_HDR_MAGIC) {
1010 if (mtd_is_eccerr(read_err))
1011 return UBI_IO_BAD_HDR_EBADMSG;
1013 if (ubi_check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) {
1015 ubi_warn("no VID header found at PEB %d, only 0xFF bytes",
1017 dbg_bld("no VID header found at PEB %d, only 0xFF bytes",
1022 return UBI_IO_FF_BITFLIPS;
1026 ubi_warn("bad magic number at PEB %d: %08x instead of %08x",
1027 pnum, magic, UBI_VID_HDR_MAGIC);
1028 ubi_dump_vid_hdr(vid_hdr);
1030 dbg_bld("bad magic number at PEB %d: %08x instead of %08x",
1031 pnum, magic, UBI_VID_HDR_MAGIC);
1032 return UBI_IO_BAD_HDR;
1035 crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
1036 hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
1038 if (hdr_crc != crc) {
1040 ubi_warn("bad CRC at PEB %d, calculated %#08x, read %#08x",
1041 pnum, crc, hdr_crc);
1042 ubi_dump_vid_hdr(vid_hdr);
1044 dbg_bld("bad CRC at PEB %d, calculated %#08x, read %#08x",
1045 pnum, crc, hdr_crc);
1047 return UBI_IO_BAD_HDR;
1049 return UBI_IO_BAD_HDR_EBADMSG;
1052 err = validate_vid_hdr(ubi, vid_hdr);
1054 ubi_err("validation failed for PEB %d", pnum);
1058 return read_err ? UBI_IO_BITFLIPS : 0;
1062 * ubi_io_write_vid_hdr - write a volume identifier header.
1063 * @ubi: UBI device description object
1064 * @pnum: the physical eraseblock number to write to
1065 * @vid_hdr: the volume identifier header to write
1067 * This function writes the volume identifier header described by @vid_hdr to
1068 * physical eraseblock @pnum. This function automatically fills the
1069 * @vid_hdr->magic and the @vid_hdr->version fields, as well as calculates
1070 * header CRC checksum and stores it at vid_hdr->hdr_crc.
1072 * This function returns zero in case of success and a negative error code in
1073 * case of failure. If %-EIO is returned, the physical eraseblock probably went
1076 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
1077 struct ubi_vid_hdr *vid_hdr)
1083 dbg_io("write VID header to PEB %d", pnum);
1084 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
1086 err = self_check_peb_ec_hdr(ubi, pnum);
1090 vid_hdr->magic = cpu_to_be32(UBI_VID_HDR_MAGIC);
1091 vid_hdr->version = UBI_VERSION;
1092 crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
1093 vid_hdr->hdr_crc = cpu_to_be32(crc);
1095 err = self_check_vid_hdr(ubi, pnum, vid_hdr);
1099 p = (char *)vid_hdr - ubi->vid_hdr_shift;
1100 err = ubi_io_write(ubi, p, pnum, ubi->vid_hdr_aloffset,
1101 ubi->vid_hdr_alsize);
1106 * self_check_not_bad - ensure that a physical eraseblock is not bad.
1107 * @ubi: UBI device description object
1108 * @pnum: physical eraseblock number to check
1110 * This function returns zero if the physical eraseblock is good, %-EINVAL if
1111 * it is bad and a negative error code if an error occurred.
1113 static int self_check_not_bad(const struct ubi_device *ubi, int pnum)
1117 if (!ubi_dbg_chk_io(ubi))
1120 err = ubi_io_is_bad(ubi, pnum);
1124 ubi_err("self-check failed for PEB %d", pnum);
1126 return err > 0 ? -EINVAL : err;
1130 * self_check_ec_hdr - check if an erase counter header is all right.
1131 * @ubi: UBI device description object
1132 * @pnum: physical eraseblock number the erase counter header belongs to
1133 * @ec_hdr: the erase counter header to check
1135 * This function returns zero if the erase counter header contains valid
1136 * values, and %-EINVAL if not.
1138 static int self_check_ec_hdr(const struct ubi_device *ubi, int pnum,
1139 const struct ubi_ec_hdr *ec_hdr)
1144 if (!ubi_dbg_chk_io(ubi))
1147 magic = be32_to_cpu(ec_hdr->magic);
1148 if (magic != UBI_EC_HDR_MAGIC) {
1149 ubi_err("bad magic %#08x, must be %#08x",
1150 magic, UBI_EC_HDR_MAGIC);
1154 err = validate_ec_hdr(ubi, ec_hdr);
1156 ubi_err("self-check failed for PEB %d", pnum);
1163 ubi_dump_ec_hdr(ec_hdr);
1169 * self_check_peb_ec_hdr - check erase counter header.
1170 * @ubi: UBI device description object
1171 * @pnum: the physical eraseblock number to check
1173 * This function returns zero if the erase counter header is all right and and
1174 * a negative error code if not or if an error occurred.
1176 static int self_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum)
1179 uint32_t crc, hdr_crc;
1180 struct ubi_ec_hdr *ec_hdr;
1182 if (!ubi_dbg_chk_io(ubi))
1185 ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS);
1189 err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
1190 if (err && err != UBI_IO_BITFLIPS && !mtd_is_eccerr(err))
1193 crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
1194 hdr_crc = be32_to_cpu(ec_hdr->hdr_crc);
1195 if (hdr_crc != crc) {
1196 ubi_err("bad CRC, calculated %#08x, read %#08x", crc, hdr_crc);
1197 ubi_err("self-check failed for PEB %d", pnum);
1198 ubi_dump_ec_hdr(ec_hdr);
1204 err = self_check_ec_hdr(ubi, pnum, ec_hdr);
1212 * self_check_vid_hdr - check that a volume identifier header is all right.
1213 * @ubi: UBI device description object
1214 * @pnum: physical eraseblock number the volume identifier header belongs to
1215 * @vid_hdr: the volume identifier header to check
1217 * This function returns zero if the volume identifier header is all right, and
1220 static int self_check_vid_hdr(const struct ubi_device *ubi, int pnum,
1221 const struct ubi_vid_hdr *vid_hdr)
1226 if (!ubi_dbg_chk_io(ubi))
1229 magic = be32_to_cpu(vid_hdr->magic);
1230 if (magic != UBI_VID_HDR_MAGIC) {
1231 ubi_err("bad VID header magic %#08x at PEB %d, must be %#08x",
1232 magic, pnum, UBI_VID_HDR_MAGIC);
1236 err = validate_vid_hdr(ubi, vid_hdr);
1238 ubi_err("self-check failed for PEB %d", pnum);
1245 ubi_err("self-check failed for PEB %d", pnum);
1246 ubi_dump_vid_hdr(vid_hdr);
1253 * self_check_peb_vid_hdr - check volume identifier header.
1254 * @ubi: UBI device description object
1255 * @pnum: the physical eraseblock number to check
1257 * This function returns zero if the volume identifier header is all right,
1258 * and a negative error code if not or if an error occurred.
1260 static int self_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum)
1263 uint32_t crc, hdr_crc;
1264 struct ubi_vid_hdr *vid_hdr;
1267 if (!ubi_dbg_chk_io(ubi))
1270 vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
1274 p = (char *)vid_hdr - ubi->vid_hdr_shift;
1275 err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
1276 ubi->vid_hdr_alsize);
1277 if (err && err != UBI_IO_BITFLIPS && !mtd_is_eccerr(err))
1280 crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_EC_HDR_SIZE_CRC);
1281 hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
1282 if (hdr_crc != crc) {
1283 ubi_err("bad VID header CRC at PEB %d, calculated %#08x, read %#08x",
1284 pnum, crc, hdr_crc);
1285 ubi_err("self-check failed for PEB %d", pnum);
1286 ubi_dump_vid_hdr(vid_hdr);
1292 err = self_check_vid_hdr(ubi, pnum, vid_hdr);
1295 ubi_free_vid_hdr(ubi, vid_hdr);
1300 * self_check_write - make sure write succeeded.
1301 * @ubi: UBI device description object
1302 * @buf: buffer with data which were written
1303 * @pnum: physical eraseblock number the data were written to
1304 * @offset: offset within the physical eraseblock the data were written to
1305 * @len: how many bytes were written
1307 * This functions reads data which were recently written and compares it with
1308 * the original data buffer - the data have to match. Returns zero if the data
1309 * match and a negative error code if not or in case of failure.
1311 static int self_check_write(struct ubi_device *ubi, const void *buf, int pnum,
1312 int offset, int len)
1317 loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
1319 if (!ubi_dbg_chk_io(ubi))
1322 buf1 = __vmalloc(len, GFP_NOFS, PAGE_KERNEL);
1324 ubi_err("cannot allocate memory to check writes");
1328 err = mtd_read(ubi->mtd, addr, len, &read, buf1);
1329 if (err && !mtd_is_bitflip(err))
1332 for (i = 0; i < len; i++) {
1333 uint8_t c = ((uint8_t *)buf)[i];
1334 uint8_t c1 = ((uint8_t *)buf1)[i];
1335 #if !defined(CONFIG_UBI_SILENCE_MSG)
1336 int dump_len = max_t(int, 128, len - i);
1342 ubi_err("self-check failed for PEB %d:%d, len %d",
1344 ubi_msg("data differ at position %d", i);
1345 ubi_msg("hex dump of the original buffer from %d to %d",
1347 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
1348 buf + i, dump_len, 1);
1349 ubi_msg("hex dump of the read buffer from %d to %d",
1351 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
1352 buf1 + i, dump_len, 1);
1367 * ubi_self_check_all_ff - check that a region of flash is empty.
1368 * @ubi: UBI device description object
1369 * @pnum: the physical eraseblock number to check
1370 * @offset: the starting offset within the physical eraseblock to check
1371 * @len: the length of the region to check
1373 * This function returns zero if only 0xFF bytes are present at offset
1374 * @offset of the physical eraseblock @pnum, and a negative error code if not
1375 * or if an error occurred.
1377 int ubi_self_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len)
1382 loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
1384 if (!ubi_dbg_chk_io(ubi))
1387 buf = __vmalloc(len, GFP_NOFS, PAGE_KERNEL);
1389 ubi_err("cannot allocate memory to check for 0xFFs");
1393 err = mtd_read(ubi->mtd, addr, len, &read, buf);
1394 if (err && !mtd_is_bitflip(err)) {
1395 ubi_err("error %d while reading %d bytes from PEB %d:%d, read %zd bytes",
1396 err, len, pnum, offset, read);
1400 err = ubi_check_pattern(buf, 0xFF, len);
1402 ubi_err("flash region at PEB %d:%d, length %d does not contain all 0xFF bytes",
1411 ubi_err("self-check failed for PEB %d", pnum);
1412 ubi_msg("hex dump of the %d-%d region", offset, offset + len);
1413 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, buf, len, 1);