io.c

uboot200903最新版本的通用uboot

		memset(ubi->peb_buf1, ~patterns[i], ubi->peb_size);
		err = ubi_io_read(ubi, ubi->peb_buf1, pnum, 0, ubi->peb_size);
		if (err)
			goto out;

		err = check_pattern(ubi->peb_buf1, patterns[i], ubi->peb_size);
		if (err == 0) {
			ubi_err("pattern %x checking failed for PEB %d",
				patterns[i], pnum);
			err = -EIO;
			goto out;
		}
	}

	err = patt_count;

out:
	mutex_unlock(&ubi->buf_mutex);
	if (err == UBI_IO_BITFLIPS || err == -EBADMSG) {
		/*
		 * If a bit-flip or data integrity error was detected, the test
		 * has not passed because it happened on a freshly erased
		 * physical eraseblock which means something is wrong with it.
		 */
		ubi_err("read problems on freshly erased PEB %d, must be bad",
			pnum);
		err = -EIO;
	}
	return err;
}

/**
 * ubi_io_sync_erase - synchronously erase a physical eraseblock.
 * @ubi: UBI device description object
 * @pnum: physical eraseblock number to erase
 * @torture: if this physical eraseblock has to be tortured
 *
 * This function synchronously erases physical eraseblock @pnum. If @torture
 * flag is not zero, the physical eraseblock is checked by means of writing
 * different patterns to it and reading them back. If the torturing is enabled,
 * the physical eraseblock is erased more then once.
 *
 * This function returns the number of erasures made in case of success, %-EIO
 * if the erasure failed or the torturing test failed, and other negative error
 * codes in case of other errors. Note, %-EIO means that the physical
 * eraseblock is bad.
 */
int ubi_io_sync_erase(struct ubi_device *ubi, int pnum, int torture)
{
	int err, ret = 0;

	ubi_assert(pnum >= 0 && pnum < ubi->peb_count);

	err = paranoid_check_not_bad(ubi, pnum);
	if (err != 0)
		return err > 0 ? -EINVAL : err;

	if (ubi->ro_mode) {
		ubi_err("read-only mode");
		return -EROFS;
	}

	if (torture) {
		ret = torture_peb(ubi, pnum);
		if (ret < 0)
			return ret;
	}

	err = do_sync_erase(ubi, pnum);
	if (err)
		return err;

	return ret + 1;
}

/**
 * ubi_io_is_bad - check if a physical eraseblock is bad.
 * @ubi: UBI device description object
 * @pnum: the physical eraseblock number to check
 *
 * This function returns a positive number if the physical eraseblock is bad,
 * zero if not, and a negative error code if an error occurred.
 */
int ubi_io_is_bad(const struct ubi_device *ubi, int pnum)
{
	struct mtd_info *mtd = ubi->mtd;

	ubi_assert(pnum >= 0 && pnum < ubi->peb_count);

	if (ubi->bad_allowed) {
		int ret;

		ret = mtd->block_isbad(mtd, (loff_t)pnum * ubi->peb_size);
		if (ret < 0)
			ubi_err("error %d while checking if PEB %d is bad",
				ret, pnum);
		else if (ret)
			dbg_io("PEB %d is bad", pnum);
		return ret;
	}

	return 0;
}

/**
 * ubi_io_mark_bad - mark a physical eraseblock as bad.
 * @ubi: UBI device description object
 * @pnum: the physical eraseblock number to mark
 *
 * This function returns zero in case of success and a negative error code in
 * case of failure.
 */
int ubi_io_mark_bad(const struct ubi_device *ubi, int pnum)
{
	int err;
	struct mtd_info *mtd = ubi->mtd;

	ubi_assert(pnum >= 0 && pnum < ubi->peb_count);

	if (ubi->ro_mode) {
		ubi_err("read-only mode");
		return -EROFS;
	}

	if (!ubi->bad_allowed)
		return 0;

	err = mtd->block_markbad(mtd, (loff_t)pnum * ubi->peb_size);
	if (err)
		ubi_err("cannot mark PEB %d bad, error %d", pnum, err);
	return err;
}

/**
 * validate_ec_hdr - validate an erase counter header.
 * @ubi: UBI device description object
 * @ec_hdr: the erase counter header to check
 *
 * This function returns zero if the erase counter header is OK, and %1 if
 * not.
 */
static int validate_ec_hdr(const struct ubi_device *ubi,
			   const struct ubi_ec_hdr *ec_hdr)
{
	long long ec;
	int vid_hdr_offset, leb_start;

	ec = be64_to_cpu(ec_hdr->ec);
	vid_hdr_offset = be32_to_cpu(ec_hdr->vid_hdr_offset);
	leb_start = be32_to_cpu(ec_hdr->data_offset);

	if (ec_hdr->version != UBI_VERSION) {
		ubi_err("node with incompatible UBI version found: "
			"this UBI version is %d, image version is %d",
			UBI_VERSION, (int)ec_hdr->version);
		goto bad;
	}

	if (vid_hdr_offset != ubi->vid_hdr_offset) {
		ubi_err("bad VID header offset %d, expected %d",
			vid_hdr_offset, ubi->vid_hdr_offset);
		goto bad;
	}

	if (leb_start != ubi->leb_start) {
		ubi_err("bad data offset %d, expected %d",
			leb_start, ubi->leb_start);
		goto bad;
	}

	if (ec < 0 || ec > UBI_MAX_ERASECOUNTER) {
		ubi_err("bad erase counter %lld", ec);
		goto bad;
	}

	return 0;

bad:
	ubi_err("bad EC header");
	ubi_dbg_dump_ec_hdr(ec_hdr);
	ubi_dbg_dump_stack();
	return 1;
}

/**
 * ubi_io_read_ec_hdr - read and check an erase counter header.
 * @ubi: UBI device description object
 * @pnum: physical eraseblock to read from
 * @ec_hdr: a &struct ubi_ec_hdr object where to store the read erase counter
 * header
 * @verbose: be verbose if the header is corrupted or was not found
 *
 * This function reads erase counter header from physical eraseblock @pnum and
 * stores it in @ec_hdr. This function also checks CRC checksum of the read
 * erase counter header. The following codes may be returned:
 *
 * o %0 if the CRC checksum is correct and the header was successfully read;
 * o %UBI_IO_BITFLIPS if the CRC is correct, but bit-flips were detected
 *   and corrected by the flash driver; this is harmless but may indicate that
 *   this eraseblock may become bad soon (but may be not);
 * o %UBI_IO_BAD_EC_HDR if the erase counter header is corrupted (a CRC error);
 * o %UBI_IO_PEB_EMPTY if the physical eraseblock is empty;
 * o a negative error code in case of failure.
 */
int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
		       struct ubi_ec_hdr *ec_hdr, int verbose)
{
	int err, read_err = 0;
	uint32_t crc, magic, hdr_crc;

	dbg_io("read EC header from PEB %d", pnum);
	ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
	if (UBI_IO_DEBUG)
		verbose = 1;

	err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
	if (err) {
		if (err != UBI_IO_BITFLIPS && err != -EBADMSG)
			return err;

		/*
		 * We read all the data, but either a correctable bit-flip
		 * occurred, or MTD reported about some data integrity error,
		 * like an ECC error in case of NAND. The former is harmless,
		 * the later may mean that the read data is corrupted. But we
		 * have a CRC check-sum and we will detect this. If the EC
		 * header is still OK, we just report this as there was a
		 * bit-flip.
		 */
		read_err = err;
	}

	magic = be32_to_cpu(ec_hdr->magic);
	if (magic != UBI_EC_HDR_MAGIC) {
		/*
		 * The magic field is wrong. Let's check if we have read all
		 * 0xFF. If yes, this physical eraseblock is assumed to be
		 * empty.
		 *
		 * But if there was a read error, we do not test it for all
		 * 0xFFs. Even if it does contain all 0xFFs, this error
		 * indicates that something is still wrong with this physical
		 * eraseblock and we anyway cannot treat it as empty.
		 */
		if (read_err != -EBADMSG &&
		    check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) {
			/* The physical eraseblock is supposedly empty */

			/*
			 * The below is just a paranoid check, it has to be
			 * compiled out if paranoid checks are disabled.
			 */
			err = paranoid_check_all_ff(ubi, pnum, 0,
						    ubi->peb_size);
			if (err)
				return err > 0 ? UBI_IO_BAD_EC_HDR : err;

			if (verbose)
				ubi_warn("no EC header found at PEB %d, "
					 "only 0xFF bytes", pnum);
			return UBI_IO_PEB_EMPTY;
		}

		/*
		 * This is not a valid erase counter header, and these are not
		 * 0xFF bytes. Report that the header is corrupted.
		 */
		if (verbose) {
			ubi_warn("bad magic number at PEB %d: %08x instead of "
				 "%08x", pnum, magic, UBI_EC_HDR_MAGIC);
			ubi_dbg_dump_ec_hdr(ec_hdr);
		}
		return UBI_IO_BAD_EC_HDR;
	}

	crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
	hdr_crc = be32_to_cpu(ec_hdr->hdr_crc);

	if (hdr_crc != crc) {
		if (verbose) {
			ubi_warn("bad EC header CRC at PEB %d, calculated %#08x,"
				 " read %#08x", pnum, crc, hdr_crc);
			ubi_dbg_dump_ec_hdr(ec_hdr);
		}
		return UBI_IO_BAD_EC_HDR;
	}

	/* And of course validate what has just been read from the media */
	err = validate_ec_hdr(ubi, ec_hdr);
	if (err) {
		ubi_err("validation failed for PEB %d", pnum);
		return -EINVAL;
	}

	return read_err ? UBI_IO_BITFLIPS : 0;
}

/**
 * ubi_io_write_ec_hdr - write an erase counter header.
 * @ubi: UBI device description object
 * @pnum: physical eraseblock to write to
 * @ec_hdr: the erase counter header to write
 *
 * This function writes erase counter header described by @ec_hdr to physical
 * eraseblock @pnum. It also fills most fields of @ec_hdr before writing, so
 * the caller do not have to fill them. Callers must only fill the @ec_hdr->ec
 * field.
 *
 * This function returns zero in case of success and a negative error code in
 * case of failure. If %-EIO is returned, the physical eraseblock most probably
 * went bad.
 */
int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
			struct ubi_ec_hdr *ec_hdr)
{
	int err;
	uint32_t crc;

	dbg_io("write EC header to PEB %d", pnum);
	ubi_assert(pnum >= 0 &&  pnum < ubi->peb_count);

	ec_hdr->magic = cpu_to_be32(UBI_EC_HDR_MAGIC);
	ec_hdr->version = UBI_VERSION;
	ec_hdr->vid_hdr_offset = cpu_to_be32(ubi->vid_hdr_offset);
	ec_hdr->data_offset = cpu_to_be32(ubi->leb_start);
	crc = crc32(UBI_CRC32_INIT, ec_hdr, UBI_EC_HDR_SIZE_CRC);
	ec_hdr->hdr_crc = cpu_to_be32(crc);

	err = paranoid_check_ec_hdr(ubi, pnum, ec_hdr);
	if (err)
		return -EINVAL;

	err = ubi_io_write(ubi, ec_hdr, pnum, 0, ubi->ec_hdr_alsize);
	return err;
}

/**
 * validate_vid_hdr - validate a volume identifier header.
 * @ubi: UBI device description object
 * @vid_hdr: the volume identifier header to check
 *
 * This function checks that data stored in the volume identifier header
 * @vid_hdr. Returns zero if the VID header is OK and %1 if not.
 */
static int validate_vid_hdr(const struct ubi_device *ubi,
			    const struct ubi_vid_hdr *vid_hdr)
{
	int vol_type = vid_hdr->vol_type;
	int copy_flag = vid_hdr->copy_flag;
	int vol_id = be32_to_cpu(vid_hdr->vol_id);
	int lnum = be32_to_cpu(vid_hdr->lnum);
	int compat = vid_hdr->compat;
	int data_size = be32_to_cpu(vid_hdr->data_size);
	int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
	int data_pad = be32_to_cpu(vid_hdr->data_pad);
	int data_crc = be32_to_cpu(vid_hdr->data_crc);
	int usable_leb_size = ubi->leb_size - data_pad;

	if (copy_flag != 0 && copy_flag != 1) {
		dbg_err("bad copy_flag");
		goto bad;
	}

	if (vol_id < 0 || lnum < 0 || data_size < 0 || used_ebs < 0 ||
	    data_pad < 0) {
		dbg_err("negative values");
		goto bad;
	}

	if (vol_id >= UBI_MAX_VOLUMES && vol_id < UBI_INTERNAL_VOL_START) {
		dbg_err("bad vol_id");
		goto bad;
	}

	if (vol_id < UBI_INTERNAL_VOL_START && compat != 0) {
		dbg_err("bad compat");
		goto bad;
	}

	if (vol_id >= UBI_INTERNAL_VOL_START && compat != UBI_COMPAT_DELETE &&
	    compat != UBI_COMPAT_RO && compat != UBI_COMPAT_PRESERVE &&
	    compat != UBI_COMPAT_REJECT) {
		dbg_err("bad compat");
		goto bad;
	}

	if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) {
		dbg_err("bad vol_type");
		goto bad;
	}

	if (data_pad >= ubi->leb_size / 2) {
		dbg_err("bad data_pad");
		goto bad;
	}

	if (vol_type == UBI_VID_STATIC) {
		/*
		 * Although from high-level point of view static volumes may
		 * contain zero bytes of data, but no VID headers can contain
		 * zero at these fields, because they empty volumes do not have
		 * mapped logical eraseblocks.
		 */
		if (used_ebs == 0) {
			dbg_err("zero used_ebs");
			goto bad;
		}
		if (data_size == 0) {
			dbg_err("zero data_size");
			goto bad;
		}
		if (lnum < used_ebs - 1) {
			if (data_size != usable_leb_size) {
				dbg_err("bad data_size");
				goto bad;
			}
		} else if (lnum == used_ebs - 1) {
			if (data_size == 0) {
				dbg_err("bad data_size at last LEB");
				goto bad;
			}
		} else {
			dbg_err("too high lnum");
			goto bad;