2 * Copyright (c) International Business Machines Corp., 2006
3 * Copyright (c) Nokia Corporation, 2006, 2007
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13 * the GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 * Author: Artem Bityutskiy (Битюцкий Артём)
23 * UBI input/output unit.
25 * This unit provides a uniform way to work with all kinds of the underlying
26 * MTD devices. It also implements handy functions for reading and writing UBI
29 * We are trying to have a paranoid mindset and not to trust to what we read
30 * from the flash media in order to be more secure and robust. So this unit
31 * validates every single header it reads from the flash media.
33 * Some words about how the eraseblock headers are stored.
35 * The erase counter header is always stored at offset zero. By default, the
36 * VID header is stored after the EC header at the closest aligned offset
37 * (i.e. aligned to the minimum I/O unit size). Data starts next to the VID
38 * header at the closest aligned offset. But this default layout may be
39 * changed. For example, for different reasons (e.g., optimization) UBI may be
40 * asked to put the VID header at further offset, and even at an unaligned
41 * offset. Of course, if the offset of the VID header is unaligned, UBI adds
42 * proper padding in front of it. Data offset may also be changed but it has to
45 * About minimal I/O units. In general, UBI assumes flash device model where
46 * there is only one minimal I/O unit size. E.g., in case of NOR flash it is 1,
47 * in case of NAND flash it is a NAND page, etc. This is reported by MTD in the
48 * @ubi->mtd->writesize field. But as an exception, UBI admits of using another
49 * (smaller) minimal I/O unit size for EC and VID headers to make it possible
50 * to do different optimizations.
52 * This is extremely useful in case of NAND flashes which admit of several
53 * write operations to one NAND page. In this case UBI can fit EC and VID
54 * headers at one NAND page. Thus, UBI may use "sub-page" size as the minimal
55 * I/O unit for the headers (the @ubi->hdrs_min_io_size field). But it still
56 * reports NAND page size (@ubi->min_io_size) as a minimal I/O unit for the UBI
59 * Example: some Samsung NANDs with 2KiB pages allow 4x 512-byte writes, so
60 * although the minimal I/O unit is 2K, UBI uses 512 bytes for EC and VID
63 * Q: why not just to treat sub-page as a minimal I/O unit of this flash
64 * device, e.g., make @ubi->min_io_size = 512 in the example above?
66 * A: because when writing a sub-page, MTD still writes a full 2K page but the
67 * bytes which are no relevant to the sub-page are 0xFF. So, basically, writing
68 * 4x512 sub-pages is 4 times slower then writing one 2KiB NAND page. Thus, we
69 * prefer to use sub-pages only for EV and VID headers.
71 * As it was noted above, the VID header may start at a non-aligned offset.
72 * For example, in case of a 2KiB page NAND flash with a 512 bytes sub-page,
73 * the VID header may reside at offset 1984 which is the last 64 bytes of the
74 * last sub-page (EC header is always at offset zero). This causes some
75 * difficulties when reading and writing VID headers.
77 * Suppose we have a 64-byte buffer and we read a VID header at it. We change
78 * the data and want to write this VID header out. As we can only write in
79 * 512-byte chunks, we have to allocate one more buffer and copy our VID header
80 * to offset 448 of this buffer.
82 * The I/O unit does the following trick in order to avoid this extra copy.
83 * It always allocates a @ubi->vid_hdr_alsize bytes buffer for the VID header
84 * and returns a pointer to offset @ubi->vid_hdr_shift of this buffer. When the
85 * VID header is being written out, it shifts the VID header pointer back and
86 * writes the whole sub-page.
89 #include <linux/crc32.h>
90 #include <linux/err.h>
93 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
94 static int paranoid_check_not_bad(const struct ubi_device *ubi, int pnum);
95 static int paranoid_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum);
96 static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum,
97 const struct ubi_ec_hdr *ec_hdr);
98 static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum);
99 static int paranoid_check_vid_hdr(const struct ubi_device *ubi, int pnum,
100 const struct ubi_vid_hdr *vid_hdr);
101 static int paranoid_check_all_ff(struct ubi_device *ubi, int pnum, int offset,
104 #define paranoid_check_not_bad(ubi, pnum) 0
105 #define paranoid_check_peb_ec_hdr(ubi, pnum) 0
106 #define paranoid_check_ec_hdr(ubi, pnum, ec_hdr) 0
107 #define paranoid_check_peb_vid_hdr(ubi, pnum) 0
108 #define paranoid_check_vid_hdr(ubi, pnum, vid_hdr) 0
109 #define paranoid_check_all_ff(ubi, pnum, offset, len) 0
113 * ubi_io_read - read data from a physical eraseblock.
114 * @ubi: UBI device description object
115 * @buf: buffer where to store the read data
116 * @pnum: physical eraseblock number to read from
117 * @offset: offset within the physical eraseblock from where to read
118 * @len: how many bytes to read
120 * This function reads data from offset @offset of physical eraseblock @pnum
121 * and stores the read data in the @buf buffer. The following return codes are
124 * o %0 if all the requested data were successfully read;
125 * o %UBI_IO_BITFLIPS if all the requested data were successfully read, but
126 * correctable bit-flips were detected; this is harmless but may indicate
127 * that this eraseblock may become bad soon (but do not have to);
128 * o %-EBADMSG if the MTD subsystem reported about data integrity problems, for
129 * example it can be an ECC error in case of NAND; this most probably means
130 * that the data is corrupted;
131 * o %-EIO if some I/O error occurred;
132 * o other negative error codes in case of other errors.
134 int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
137 int err, retries = 0;
141 dbg_io("read %d bytes from PEB %d:%d", len, pnum, offset);
143 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
144 ubi_assert(offset >= 0 && offset + len <= ubi->peb_size);
147 err = paranoid_check_not_bad(ubi, pnum);
149 return err > 0 ? -EINVAL : err;
151 addr = (loff_t)pnum * ubi->peb_size + offset;
153 err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf);
155 if (err == -EUCLEAN) {
157 * -EUCLEAN is reported if there was a bit-flip which
158 * was corrected, so this is harmless.
160 ubi_msg("fixable bit-flip detected at PEB %d", pnum);
161 ubi_assert(len == read);
162 return UBI_IO_BITFLIPS;
165 if (read != len && retries++ < UBI_IO_RETRIES) {
166 dbg_io("error %d while reading %d bytes from PEB %d:%d, "
167 "read only %zd bytes, retry",
168 err, len, pnum, offset, read);
173 ubi_err("error %d while reading %d bytes from PEB %d:%d, "
174 "read %zd bytes", err, len, pnum, offset, read);
175 ubi_dbg_dump_stack();
178 * The driver should never return -EBADMSG if it failed to read
179 * all the requested data. But some buggy drivers might do
180 * this, so we change it to -EIO.
182 if (read != len && err == -EBADMSG) {
187 ubi_assert(len == read);
189 if (ubi_dbg_is_bitflip()) {
190 dbg_msg("bit-flip (emulated)");
191 err = UBI_IO_BITFLIPS;
199 * ubi_io_write - write data to a physical eraseblock.
200 * @ubi: UBI device description object
201 * @buf: buffer with the data to write
202 * @pnum: physical eraseblock number to write to
203 * @offset: offset within the physical eraseblock where to write
204 * @len: how many bytes to write
206 * This function writes @len bytes of data from buffer @buf to offset @offset
207 * of physical eraseblock @pnum. If all the data were successfully written,
208 * zero is returned. If an error occurred, this function returns a negative
209 * error code. If %-EIO is returned, the physical eraseblock most probably went
212 * Note, in case of an error, it is possible that something was still written
213 * to the flash media, but may be some garbage.
215 int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
222 dbg_io("write %d bytes to PEB %d:%d", len, pnum, offset);
224 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
225 ubi_assert(offset >= 0 && offset + len <= ubi->peb_size);
226 ubi_assert(offset % ubi->hdrs_min_io_size == 0);
227 ubi_assert(len > 0 && len % ubi->hdrs_min_io_size == 0);
230 ubi_err("read-only mode");
234 /* The below has to be compiled out if paranoid checks are disabled */
236 err = paranoid_check_not_bad(ubi, pnum);
238 return err > 0 ? -EINVAL : err;
240 /* The area we are writing to has to contain all 0xFF bytes */
241 err = paranoid_check_all_ff(ubi, pnum, offset, len);
243 return err > 0 ? -EINVAL : err;
245 if (offset >= ubi->leb_start) {
247 * We write to the data area of the physical eraseblock. Make
248 * sure it has valid EC and VID headers.
250 err = paranoid_check_peb_ec_hdr(ubi, pnum);
252 return err > 0 ? -EINVAL : err;
253 err = paranoid_check_peb_vid_hdr(ubi, pnum);
255 return err > 0 ? -EINVAL : err;
258 if (ubi_dbg_is_write_failure()) {
259 dbg_err("cannot write %d bytes to PEB %d:%d "
260 "(emulated)", len, pnum, offset);
261 ubi_dbg_dump_stack();
265 addr = (loff_t)pnum * ubi->peb_size + offset;
266 err = ubi->mtd->write(ubi->mtd, addr, len, &written, buf);
268 ubi_err("error %d while writing %d bytes to PEB %d:%d, written"
269 " %zd bytes", err, len, pnum, offset, written);
270 ubi_dbg_dump_stack();
272 ubi_assert(written == len);
278 * erase_callback - MTD erasure call-back.
279 * @ei: MTD erase information object.
281 * Note, even though MTD erase interface is asynchronous, all the current
282 * implementations are synchronous anyway.
284 static void erase_callback(struct erase_info *ei)
286 wake_up_interruptible((wait_queue_head_t *)ei->priv);
290 * do_sync_erase - synchronously erase a physical eraseblock.
291 * @ubi: UBI device description object
292 * @pnum: the physical eraseblock number to erase
294 * This function synchronously erases physical eraseblock @pnum and returns
295 * zero in case of success and a negative error code in case of failure. If
296 * %-EIO is returned, the physical eraseblock most probably went bad.
298 static int do_sync_erase(struct ubi_device *ubi, int pnum)
300 int err, retries = 0;
301 struct erase_info ei;
302 wait_queue_head_t wq;
304 dbg_io("erase PEB %d", pnum);
307 init_waitqueue_head(&wq);
308 memset(&ei, 0, sizeof(struct erase_info));
311 ei.addr = (loff_t)pnum * ubi->peb_size;
312 ei.len = ubi->peb_size;
313 ei.callback = erase_callback;
314 ei.priv = (unsigned long)&wq;
316 err = ubi->mtd->erase(ubi->mtd, &ei);
318 if (retries++ < UBI_IO_RETRIES) {
319 dbg_io("error %d while erasing PEB %d, retry",
324 ubi_err("cannot erase PEB %d, error %d", pnum, err);
325 ubi_dbg_dump_stack();
329 err = wait_event_interruptible(wq, ei.state == MTD_ERASE_DONE ||
330 ei.state == MTD_ERASE_FAILED);
332 ubi_err("interrupted PEB %d erasure", pnum);
336 if (ei.state == MTD_ERASE_FAILED) {
337 if (retries++ < UBI_IO_RETRIES) {
338 dbg_io("error while erasing PEB %d, retry", pnum);
342 ubi_err("cannot erase PEB %d", pnum);
343 ubi_dbg_dump_stack();
347 err = paranoid_check_all_ff(ubi, pnum, 0, ubi->peb_size);
349 return err > 0 ? -EINVAL : err;
351 if (ubi_dbg_is_erase_failure() && !err) {
352 dbg_err("cannot erase PEB %d (emulated)", pnum);
360 * check_pattern - check if buffer contains only a certain byte pattern.
361 * @buf: buffer to check
362 * @patt: the pattern to check
363 * @size: buffer size in bytes
365 * This function returns %1 in there are only @patt bytes in @buf, and %0 if
366 * something else was also found.
368 static int check_pattern(const void *buf, uint8_t patt, int size)
372 for (i = 0; i < size; i++)
373 if (((const uint8_t *)buf)[i] != patt)
378 /* Patterns to write to a physical eraseblock when torturing it */
379 static uint8_t patterns[] = {0xa5, 0x5a, 0x0};
382 * torture_peb - test a supposedly bad physical eraseblock.
383 * @ubi: UBI device description object
384 * @pnum: the physical eraseblock number to test
386 * This function returns %-EIO if the physical eraseblock did not pass the
387 * test, a positive number of erase operations done if the test was
388 * successfully passed, and other negative error codes in case of other errors.
390 static int torture_peb(struct ubi_device *ubi, int pnum)
392 int err, i, patt_count;
394 patt_count = ARRAY_SIZE(patterns);
395 ubi_assert(patt_count > 0);
397 mutex_lock(&ubi->buf_mutex);
398 for (i = 0; i < patt_count; i++) {
399 err = do_sync_erase(ubi, pnum);
403 /* Make sure the PEB contains only 0xFF bytes */
404 err = ubi_io_read(ubi, ubi->peb_buf1, pnum, 0, ubi->peb_size);
408 err = check_pattern(ubi->peb_buf1, 0xFF, ubi->peb_size);
410 ubi_err("erased PEB %d, but a non-0xFF byte found",
416 /* Write a pattern and check it */
417 memset(ubi->peb_buf1, patterns[i], ubi->peb_size);
418 err = ubi_io_write(ubi, ubi->peb_buf1, pnum, 0, ubi->peb_size);
422 memset(ubi->peb_buf1, ~patterns[i], ubi->peb_size);
423 err = ubi_io_read(ubi, ubi->peb_buf1, pnum, 0, ubi->peb_size);
427 err = check_pattern(ubi->peb_buf1, patterns[i], ubi->peb_size);
429 ubi_err("pattern %x checking failed for PEB %d",
439 mutex_unlock(&ubi->buf_mutex);
440 if (err == UBI_IO_BITFLIPS || err == -EBADMSG) {
442 * If a bit-flip or data integrity error was detected, the test
443 * has not passed because it happened on a freshly erased
444 * physical eraseblock which means something is wrong with it.
446 ubi_err("read problems on freshly erased PEB %d, must be bad",
454 * ubi_io_sync_erase - synchronously erase a physical eraseblock.
455 * @ubi: UBI device description object
456 * @pnum: physical eraseblock number to erase
457 * @torture: if this physical eraseblock has to be tortured
459 * This function synchronously erases physical eraseblock @pnum. If @torture
460 * flag is not zero, the physical eraseblock is checked by means of writing
461 * different patterns to it and reading them back. If the torturing is enabled,
462 * the physical eraseblock is erased more then once.
464 * This function returns the number of erasures made in case of success, %-EIO
465 * if the erasure failed or the torturing test failed, and other negative error
466 * codes in case of other errors. Note, %-EIO means that the physical
469 int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture)
473 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
475 err = paranoid_check_not_bad(ubi, pnum);
477 return err > 0 ? -EINVAL : err;
480 ubi_err("read-only mode");
485 ret = torture_peb(ubi, pnum);
490 err = do_sync_erase(ubi, pnum);
498 * ubi_io_is_bad - check if a physical eraseblock is bad.
499 * @ubi: UBI device description object
500 * @pnum: the physical eraseblock number to check
502 * This function returns a positive number if the physical eraseblock is bad,
503 * zero if not, and a negative error code if an error occurred.
505 int ubi_io_is_bad(const struct ubi_device *ubi, int pnum)
507 struct mtd_info *mtd = ubi->mtd;
509 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
511 if (ubi->bad_allowed) {
514 ret = mtd->block_isbad(mtd, (loff_t)pnum * ubi->peb_size);
516 ubi_err("error %d while checking if PEB %d is bad",
519 dbg_io("PEB %d is bad", pnum);
527 * ubi_io_mark_bad - mark a physical eraseblock as bad.
528 * @ubi: UBI device description object
529 * @pnum: the physical eraseblock number to mark
531 * This function returns zero in case of success and a negative error code in
534 int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum)
537 struct mtd_info *mtd = ubi->mtd;
539 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
542 ubi_err("read-only mode");
546 if (!ubi->bad_allowed)
549 err = mtd->block_markbad(mtd, (loff_t)pnum * ubi->peb_size);
551 ubi_err("cannot mark PEB %d bad, error %d", pnum, err);
556 * validate_ec_hdr - validate an erase counter header.
557 * @ubi: UBI device description object
558 * @ec_hdr: the erase counter header to check
560 * This function returns zero if the erase counter header is OK, and %1 if
563 static int validate_ec_hdr(const struct ubi_device *ubi,
564 const struct ubi_ec_hdr *ec_hdr)
567 int vid_hdr_offset, leb_start;
569 ec = be64_to_cpu(ec_hdr->ec);
570 vid_hdr_offset = be32_to_cpu(ec_hdr->vid_hdr_offset);
571 leb_start = be32_to_cpu(ec_hdr->data_offset);
573 if (ec_hdr->version != UBI_VERSION) {
574 ubi_err("node with incompatible UBI version found: "
575 "this UBI version is %d, image version is %d",
576 UBI_VERSION, (int)ec_hdr->version);
580 if (vid_hdr_offset != ubi->vid_hdr_offset) {
581 ubi_err("bad VID header offset %d, expected %d",
582 vid_hdr_offset, ubi->vid_hdr_offset);
586 if (leb_start != ubi->leb_start) {
587 ubi_err("bad data offset %d, expected %d",
588 leb_start, ubi->leb_start);
592 if (ec < 0 || ec > UBI_MAX_ERASECOUNTER) {
593 ubi_err("bad erase counter %lld", ec);
600 ubi_err("bad EC header");
601 ubi_dbg_dump_ec_hdr(ec_hdr);
602 ubi_dbg_dump_stack();
607 * ubi_io_read_ec_hdr - read and check an erase counter header.
608 * @ubi: UBI device description object
609 * @pnum: physical eraseblock to read from
610 * @ec_hdr: a &struct ubi_ec_hdr object where to store the read erase counter
612 * @verbose: be verbose if the header is corrupted or was not found
614 * This function reads erase counter header from physical eraseblock @pnum and
615 * stores it in @ec_hdr. This function also checks CRC checksum of the read
616 * erase counter header. The following codes may be returned:
618 * o %0 if the CRC checksum is correct and the header was successfully read;
619 * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected
620 * and corrected by the flash driver; this is harmless but may indicate that
621 * this eraseblock may become bad soon (but may be not);
622 * o %UBI_IO_BAD_EC_HDR if the erase counter header is corrupted (a CRC error);
623 * o %UBI_IO_PEB_EMPTY if the physical eraseblock is empty;
624 * o a negative error code in case of failure.
626 int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
627 struct ubi_ec_hdr *ec_hdr, int verbose)
629 int err, read_err = 0;
630 uint32_t crc, magic, hdr_crc;
632 dbg_io("read EC header from PEB %d", pnum);
633 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
635 err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
637 if (err != UBI_IO_BITFLIPS && err != -EBADMSG)
641 * We read all the data, but either a correctable bit-flip
642 * occurred, or MTD reported about some data integrity error,
643 * like an ECC error in case of NAND. The former is harmless,
644 * the later may mean that the read data is corrupted. But we
645 * have a CRC check-sum and we will detect this. If the EC
646 * header is still OK, we just report this as there was a
652 magic = be32_to_cpu(ec_hdr->magic);
653 if (magic != UBI_EC_HDR_MAGIC) {
655 * The magic field is wrong. Let's check if we have read all
656 * 0xFF. If yes, this physical eraseblock is assumed to be
659 * But if there was a read error, we do not test it for all
660 * 0xFFs. Even if it does contain all 0xFFs, this error
661 * indicates that something is still wrong with this physical
662 * eraseblock and we anyway cannot treat it as empty.
664 if (read_err != -EBADMSG &&
665 check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) {
666 /* The physical eraseblock is supposedly empty */
669 * The below is just a paranoid check, it has to be
670 * compiled out if paranoid checks are disabled.
672 err = paranoid_check_all_ff(ubi, pnum, 0,
675 return err > 0 ? UBI_IO_BAD_EC_HDR : err;
678 ubi_warn("no EC header found at PEB %d, "
679 "only 0xFF bytes", pnum);
680 return UBI_IO_PEB_EMPTY;
684 * This is not a valid erase counter header, and these are not
685 * 0xFF bytes. Report that the header is corrupted.
688 ubi_warn("bad magic number at PEB %d: %08x instead of "
689 "%08x", pnum, magic, UBI_EC_HDR_MAGIC);
690 ubi_dbg_dump_ec_hdr(ec_hdr);
692 return UBI_IO_BAD_EC_HDR;
695 crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
696 hdr_crc = be32_to_cpu(ec_hdr->hdr_crc);
698 if (hdr_crc != crc) {
700 ubi_warn("bad EC header CRC at PEB %d, calculated %#08x,"
701 " read %#08x", pnum, crc, hdr_crc);
702 ubi_dbg_dump_ec_hdr(ec_hdr);
704 return UBI_IO_BAD_EC_HDR;
707 /* And of course validate what has just been read from the media */
708 err = validate_ec_hdr(ubi, ec_hdr);
710 ubi_err("validation failed for PEB %d", pnum);
714 return read_err ? UBI_IO_BITFLIPS : 0;
718 * ubi_io_write_ec_hdr - write an erase counter header.
719 * @ubi: UBI device description object
720 * @pnum: physical eraseblock to write to
721 * @ec_hdr: the erase counter header to write
723 * This function writes erase counter header described by @ec_hdr to physical
724 * eraseblock @pnum. It also fills most fields of @ec_hdr before writing, so
725 * the caller do not have to fill them. Callers must only fill the @ec_hdr->ec
728 * This function returns zero in case of success and a negative error code in
729 * case of failure. If %-EIO is returned, the physical eraseblock most probably
732 int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
733 struct ubi_ec_hdr *ec_hdr)
738 dbg_io("write EC header to PEB %d", pnum);
739 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
741 ec_hdr->magic = cpu_to_be32(UBI_EC_HDR_MAGIC);
742 ec_hdr->version = UBI_VERSION;
743 ec_hdr->vid_hdr_offset = cpu_to_be32(ubi->vid_hdr_offset);
744 ec_hdr->data_offset = cpu_to_be32(ubi->leb_start);
745 crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
746 ec_hdr->hdr_crc = cpu_to_be32(crc);
748 err = paranoid_check_ec_hdr(ubi, pnum, ec_hdr);
752 err = ubi_io_write(ubi, ec_hdr, pnum, 0, ubi->ec_hdr_alsize);
757 * validate_vid_hdr - validate a volume identifier header.
758 * @ubi: UBI device description object
759 * @vid_hdr: the volume identifier header to check
761 * This function checks that data stored in the volume identifier header
762 * @vid_hdr. Returns zero if the VID header is OK and %1 if not.
764 static int validate_vid_hdr(const struct ubi_device *ubi,
765 const struct ubi_vid_hdr *vid_hdr)
767 int vol_type = vid_hdr->vol_type;
768 int copy_flag = vid_hdr->copy_flag;
769 int vol_id = be32_to_cpu(vid_hdr->vol_id);
770 int lnum = be32_to_cpu(vid_hdr->lnum);
771 int compat = vid_hdr->compat;
772 int data_size = be32_to_cpu(vid_hdr->data_size);
773 int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
774 int data_pad = be32_to_cpu(vid_hdr->data_pad);
775 int data_crc = be32_to_cpu(vid_hdr->data_crc);
776 int usable_leb_size = ubi->leb_size - data_pad;
778 if (copy_flag != 0 && copy_flag != 1) {
779 dbg_err("bad copy_flag");
783 if (vol_id < 0 || lnum < 0 || data_size < 0 || used_ebs < 0 ||
785 dbg_err("negative values");
789 if (vol_id >= UBI_MAX_VOLUMES && vol_id < UBI_INTERNAL_VOL_START) {
790 dbg_err("bad vol_id");
794 if (vol_id < UBI_INTERNAL_VOL_START && compat != 0) {
795 dbg_err("bad compat");
799 if (vol_id >= UBI_INTERNAL_VOL_START && compat != UBI_COMPAT_DELETE &&
800 compat != UBI_COMPAT_RO && compat != UBI_COMPAT_PRESERVE &&
801 compat != UBI_COMPAT_REJECT) {
802 dbg_err("bad compat");
806 if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) {
807 dbg_err("bad vol_type");
811 if (data_pad >= ubi->leb_size / 2) {
812 dbg_err("bad data_pad");
816 if (vol_type == UBI_VID_STATIC) {
818 * Although from high-level point of view static volumes may
819 * contain zero bytes of data, but no VID headers can contain
820 * zero at these fields, because they empty volumes do not have
821 * mapped logical eraseblocks.
824 dbg_err("zero used_ebs");
827 if (data_size == 0) {
828 dbg_err("zero data_size");
831 if (lnum < used_ebs - 1) {
832 if (data_size != usable_leb_size) {
833 dbg_err("bad data_size");
836 } else if (lnum == used_ebs - 1) {
837 if (data_size == 0) {
838 dbg_err("bad data_size at last LEB");
842 dbg_err("too high lnum");
846 if (copy_flag == 0) {
848 dbg_err("non-zero data CRC");
851 if (data_size != 0) {
852 dbg_err("non-zero data_size");
856 if (data_size == 0) {
857 dbg_err("zero data_size of copy");
862 dbg_err("bad used_ebs");
870 ubi_err("bad VID header");
871 ubi_dbg_dump_vid_hdr(vid_hdr);
872 ubi_dbg_dump_stack();
877 * ubi_io_read_vid_hdr - read and check a volume identifier header.
878 * @ubi: UBI device description object
879 * @pnum: physical eraseblock number to read from
880 * @vid_hdr: &struct ubi_vid_hdr object where to store the read volume
882 * @verbose: be verbose if the header is corrupted or wasn't found
884 * This function reads the volume identifier header from physical eraseblock
885 * @pnum and stores it in @vid_hdr. It also checks CRC checksum of the read
886 * volume identifier header. The following codes may be returned:
888 * o %0 if the CRC checksum is correct and the header was successfully read;
889 * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected
890 * and corrected by the flash driver; this is harmless but may indicate that
891 * this eraseblock may become bad soon;
892 * o %UBI_IO_BAD_VID_HRD if the volume identifier header is corrupted (a CRC
894 * o %UBI_IO_PEB_FREE if the physical eraseblock is free (i.e., there is no VID
896 * o a negative error code in case of failure.
898 int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
899 struct ubi_vid_hdr *vid_hdr, int verbose)
901 int err, read_err = 0;
902 uint32_t crc, magic, hdr_crc;
905 dbg_io("read VID header from PEB %d", pnum);
906 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
908 p = (char *)vid_hdr - ubi->vid_hdr_shift;
909 err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
910 ubi->vid_hdr_alsize);
912 if (err != UBI_IO_BITFLIPS && err != -EBADMSG)
916 * We read all the data, but either a correctable bit-flip
917 * occurred, or MTD reported about some data integrity error,
918 * like an ECC error in case of NAND. The former is harmless,
919 * the later may mean the read data is corrupted. But we have a
920 * CRC check-sum and we will identify this. If the VID header is
921 * still OK, we just report this as there was a bit-flip.
926 magic = be32_to_cpu(vid_hdr->magic);
927 if (magic != UBI_VID_HDR_MAGIC) {
929 * If we have read all 0xFF bytes, the VID header probably does
930 * not exist and the physical eraseblock is assumed to be free.
932 * But if there was a read error, we do not test the data for
933 * 0xFFs. Even if it does contain all 0xFFs, this error
934 * indicates that something is still wrong with this physical
935 * eraseblock and it cannot be regarded as free.
937 if (read_err != -EBADMSG &&
938 check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) {
939 /* The physical eraseblock is supposedly free */
942 * The below is just a paranoid check, it has to be
943 * compiled out if paranoid checks are disabled.
945 err = paranoid_check_all_ff(ubi, pnum, ubi->leb_start,
948 return err > 0 ? UBI_IO_BAD_VID_HDR : err;
951 ubi_warn("no VID header found at PEB %d, "
952 "only 0xFF bytes", pnum);
953 return UBI_IO_PEB_FREE;
957 * This is not a valid VID header, and these are not 0xFF
958 * bytes. Report that the header is corrupted.
961 ubi_warn("bad magic number at PEB %d: %08x instead of "
962 "%08x", pnum, magic, UBI_VID_HDR_MAGIC);
963 ubi_dbg_dump_vid_hdr(vid_hdr);
965 return UBI_IO_BAD_VID_HDR;
968 crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
969 hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
971 if (hdr_crc != crc) {
973 ubi_warn("bad CRC at PEB %d, calculated %#08x, "
974 "read %#08x", pnum, crc, hdr_crc);
975 ubi_dbg_dump_vid_hdr(vid_hdr);
977 return UBI_IO_BAD_VID_HDR;
980 /* Validate the VID header that we have just read */
981 err = validate_vid_hdr(ubi, vid_hdr);
983 ubi_err("validation failed for PEB %d", pnum);
987 return read_err ? UBI_IO_BITFLIPS : 0;
991 * ubi_io_write_vid_hdr - write a volume identifier header.
992 * @ubi: UBI device description object
993 * @pnum: the physical eraseblock number to write to
994 * @vid_hdr: the volume identifier header to write
996 * This function writes the volume identifier header described by @vid_hdr to
997 * physical eraseblock @pnum. This function automatically fills the
998 * @vid_hdr->magic and the @vid_hdr->version fields, as well as calculates
999 * header CRC checksum and stores it at vid_hdr->hdr_crc.
1001 * This function returns zero in case of success and a negative error code in
1002 * case of failure. If %-EIO is returned, the physical eraseblock probably went
1005 int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
1006 struct ubi_vid_hdr *vid_hdr)
1012 dbg_io("write VID header to PEB %d", pnum);
1013 ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
1015 err = paranoid_check_peb_ec_hdr(ubi, pnum);
1017 return err > 0 ? -EINVAL: err;
1019 vid_hdr->magic = cpu_to_be32(UBI_VID_HDR_MAGIC);
1020 vid_hdr->version = UBI_VERSION;
1021 crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
1022 vid_hdr->hdr_crc = cpu_to_be32(crc);
1024 err = paranoid_check_vid_hdr(ubi, pnum, vid_hdr);
1028 p = (char *)vid_hdr - ubi->vid_hdr_shift;
1029 err = ubi_io_write(ubi, p, pnum, ubi->vid_hdr_aloffset,
1030 ubi->vid_hdr_alsize);
1034 #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
1037 * paranoid_check_not_bad - ensure that a physical eraseblock is not bad.
1038 * @ubi: UBI device description object
1039 * @pnum: physical eraseblock number to check
1041 * This function returns zero if the physical eraseblock is good, a positive
1042 * number if it is bad and a negative error code if an error occurred.
1044 static int paranoid_check_not_bad(const struct ubi_device *ubi, int pnum)
1048 err = ubi_io_is_bad(ubi, pnum);
1052 ubi_err("paranoid check failed for PEB %d", pnum);
1053 ubi_dbg_dump_stack();
1058 * paranoid_check_ec_hdr - check if an erase counter header is all right.
1059 * @ubi: UBI device description object
1060 * @pnum: physical eraseblock number the erase counter header belongs to
1061 * @ec_hdr: the erase counter header to check
1063 * This function returns zero if the erase counter header contains valid
1064 * values, and %1 if not.
1066 static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum,
1067 const struct ubi_ec_hdr *ec_hdr)
1072 magic = be32_to_cpu(ec_hdr->magic);
1073 if (magic != UBI_EC_HDR_MAGIC) {
1074 ubi_err("bad magic %#08x, must be %#08x",
1075 magic, UBI_EC_HDR_MAGIC);
1079 err = validate_ec_hdr(ubi, ec_hdr);
1081 ubi_err("paranoid check failed for PEB %d", pnum);
1088 ubi_dbg_dump_ec_hdr(ec_hdr);
1089 ubi_dbg_dump_stack();
1094 * paranoid_check_peb_ec_hdr - check that the erase counter header of a
1095 * physical eraseblock is in-place and is all right.
1096 * @ubi: UBI device description object
1097 * @pnum: the physical eraseblock number to check
1099 * This function returns zero if the erase counter header is all right, %1 if
1100 * not, and a negative error code if an error occurred.
1102 static int paranoid_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum)
1105 uint32_t crc, hdr_crc;
1106 struct ubi_ec_hdr *ec_hdr;
1108 ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS);
1112 err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
1113 if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG)
1116 crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
1117 hdr_crc = be32_to_cpu(ec_hdr->hdr_crc);
1118 if (hdr_crc != crc) {
1119 ubi_err("bad CRC, calculated %#08x, read %#08x", crc, hdr_crc);
1120 ubi_err("paranoid check failed for PEB %d", pnum);
1121 ubi_dbg_dump_ec_hdr(ec_hdr);
1122 ubi_dbg_dump_stack();
1127 err = paranoid_check_ec_hdr(ubi, pnum, ec_hdr);
1135 * paranoid_check_vid_hdr - check that a volume identifier header is all right.
1136 * @ubi: UBI device description object
1137 * @pnum: physical eraseblock number the volume identifier header belongs to
1138 * @vid_hdr: the volume identifier header to check
1140 * This function returns zero if the volume identifier header is all right, and
1143 static int paranoid_check_vid_hdr(const struct ubi_device *ubi, int pnum,
1144 const struct ubi_vid_hdr *vid_hdr)
1149 magic = be32_to_cpu(vid_hdr->magic);
1150 if (magic != UBI_VID_HDR_MAGIC) {
1151 ubi_err("bad VID header magic %#08x at PEB %d, must be %#08x",
1152 magic, pnum, UBI_VID_HDR_MAGIC);
1156 err = validate_vid_hdr(ubi, vid_hdr);
1158 ubi_err("paranoid check failed for PEB %d", pnum);
1165 ubi_err("paranoid check failed for PEB %d", pnum);
1166 ubi_dbg_dump_vid_hdr(vid_hdr);
1167 ubi_dbg_dump_stack();
1173 * paranoid_check_peb_vid_hdr - check that the volume identifier header of a
1174 * physical eraseblock is in-place and is all right.
1175 * @ubi: UBI device description object
1176 * @pnum: the physical eraseblock number to check
1178 * This function returns zero if the volume identifier header is all right,
1179 * %1 if not, and a negative error code if an error occurred.
1181 static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum)
1184 uint32_t crc, hdr_crc;
1185 struct ubi_vid_hdr *vid_hdr;
1188 vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
1192 p = (char *)vid_hdr - ubi->vid_hdr_shift;
1193 err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
1194 ubi->vid_hdr_alsize);
1195 if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG)
1198 crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_EC_HDR_SIZE_CRC);
1199 hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
1200 if (hdr_crc != crc) {
1201 ubi_err("bad VID header CRC at PEB %d, calculated %#08x, "
1202 "read %#08x", pnum, crc, hdr_crc);
1203 ubi_err("paranoid check failed for PEB %d", pnum);
1204 ubi_dbg_dump_vid_hdr(vid_hdr);
1205 ubi_dbg_dump_stack();
1210 err = paranoid_check_vid_hdr(ubi, pnum, vid_hdr);
1213 ubi_free_vid_hdr(ubi, vid_hdr);
1218 * paranoid_check_all_ff - check that a region of flash is empty.
1219 * @ubi: UBI device description object
1220 * @pnum: the physical eraseblock number to check
1221 * @offset: the starting offset within the physical eraseblock to check
1222 * @len: the length of the region to check
1224 * This function returns zero if only 0xFF bytes are present at offset
1225 * @offset of the physical eraseblock @pnum, %1 if not, and a negative error
1226 * code if an error occurred.
1228 static int paranoid_check_all_ff(struct ubi_device *ubi, int pnum, int offset,
1233 loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
1235 mutex_lock(&ubi->dbg_buf_mutex);
1236 err = ubi->mtd->read(ubi->mtd, addr, len, &read, ubi->dbg_peb_buf);
1237 if (err && err != -EUCLEAN) {
1238 ubi_err("error %d while reading %d bytes from PEB %d:%d, "
1239 "read %zd bytes", err, len, pnum, offset, read);
1243 err = check_pattern(ubi->dbg_peb_buf, 0xFF, len);
1245 ubi_err("flash region at PEB %d:%d, length %d does not "
1246 "contain all 0xFF bytes", pnum, offset, len);
1249 mutex_unlock(&ubi->dbg_buf_mutex);
1254 ubi_err("paranoid check failed for PEB %d", pnum);
1255 dbg_msg("hex dump of the %d-%d region", offset, offset + len);
1256 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
1257 ubi->dbg_peb_buf, len, 1);
1260 ubi_dbg_dump_stack();
1261 mutex_unlock(&ubi->dbg_buf_mutex);
1265 #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */