/**
* ubi_io_write - write data to a physical eraseblock.
* @ubi: UBI device description object
* @buf: buffer with the data to write
* @pnum: physical eraseblock number to write to
* @offset: offset within the physical eraseblock where to write
* @len: how many bytes to write
*
* This function writes @len bytes of data from buffer @buf to offset @offset
* of physical eraseblock @pnum. If all the data were successfully written,
* zero is returned. If an error occurred, this function returns a negative
* error code. If %-EIO is returned, the physical eraseblock most probably went
* bad.
*
* Note, in case of an error, it is possible that something was still written
* to the flash media, but may be some garbage.
*/
int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
int len)
{
int err;
size_t written;
loff_t addr;
dbg_io("write %d bytes to PEB %d:%d", len, pnum, offset);
ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
ubi_assert(offset >= 0 && offset + len <= ubi->peb_size);
ubi_assert(offset % ubi->hdrs_min_io_size == 0);
ubi_assert(len > 0 && len % ubi->hdrs_min_io_size == 0);
if (ubi->ro_mode) {
ubi_err("read-only mode");
return -EROFS;
}
err = self_check_not_bad(ubi, pnum);
if (err)
return err;
/* The area we are writing to has to contain all 0xFF bytes */
err = ubi_self_check_all_ff(ubi, pnum, offset, len);
if (err)
return err;
if (offset >= ubi->leb_start) {
/*
* We write to the data area of the physical eraseblock. Make
* sure it has valid EC and VID headers.
*/
err = self_check_peb_ec_hdr(ubi, pnum);
if (err)
return err;
err = self_check_peb_vid_hdr(ubi, pnum);
if (err)
return err;
}
if (ubi_dbg_is_write_failure(ubi)) {
ubi_err("cannot write %d bytes to PEB %d:%d (emulated)",
len, pnum, offset);
dump_stack();
return -EIO;
}
addr = (loff_t)pnum * ubi->peb_size + offset;
err = mtd_write(ubi->mtd, addr, len, &written, buf);
if (err) {
ubi_err("error %d while writing %d bytes to PEB %d:%d, written %zd bytes",
err, len, pnum, offset, written);
dump_stack();
ubi_dump_flash(ubi, pnum, offset, len);
} else
ubi_assert(written == len);
if (!err) {
err = self_check_write(ubi, buf, pnum, offset, len);
if (err)
return err;
/*
* Since we always write sequentially, the rest of the PEB has
* to contain only 0xFF bytes.
*/
offset += len;
len = ubi->peb_size - offset;
if (len)
err = ubi_self_check_all_ff(ubi, pnum, offset, len);
}
return err;
}
/**
* do_sync_erase - synchronously erase a physical eraseblock.
* @ubi: UBI device description object
* @pnum: the physical eraseblock number to erase
*
* This function synchronously erases physical eraseblock @pnum and 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.
*/
static int do_sync_erase(struct ubi_device *ubi, int pnum)
{
int err, retries = 0;
struct erase_info ei;
wait_queue_head_t wq;
dbg_io("erase PEB %d", pnum);
ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
if (ubi->ro_mode) {
ubi_err("read-only mode");
return -EROFS;
}
retry:
init_waitqueue_head(&wq);
memset(&ei, 0, sizeof(struct erase_info));
ei.mtd = ubi->mtd;
ei.addr = (loff_t)pnum * ubi->peb_size;
ei.len = ubi->peb_size;
ei.callback = erase_callback;
ei.priv = (unsigned long)&wq;
err = mtd_erase(ubi->mtd, &ei);
if (err) {
if (retries++ < UBI_IO_RETRIES) {
ubi_warn("error %d while erasing PEB %d, retry",
err, pnum);
yield();
goto retry;
}
ubi_err("cannot erase PEB %d, error %d", pnum, err);
dump_stack();
return err;
}
err = wait_event_interruptible(wq, ei.state == MTD_ERASE_DONE ||
ei.state == MTD_ERASE_FAILED);
if (err) {
ubi_err("interrupted PEB %d erasure", pnum);
return -EINTR;
}
if (ei.state == MTD_ERASE_FAILED) {
if (retries++ < UBI_IO_RETRIES) {
ubi_warn("error while erasing PEB %d, retry", pnum);
yield();
goto retry;
}
ubi_err("cannot erase PEB %d", pnum);
dump_stack();
return -EIO;
}
err = ubi_self_check_all_ff(ubi, pnum, 0, ubi->peb_size);
if (err)
return err;
if (ubi_dbg_is_erase_failure(ubi)) {
ubi_err("cannot erase PEB %d (emulated)", pnum);
return -EIO;
}
return 0;
}
/**
* ubi_io_read_vid_hdr - read and check a volume identifier header.
* @ubi: UBI device description object
* @pnum: physical eraseblock number to read from
* @vid_hdr: &struct ubi_vid_hdr object where to store the read volume
* identifier header
* @verbose: be verbose if the header is corrupted or wasn't found
*
* This function reads the volume identifier header from physical eraseblock
* @pnum and stores it in @vid_hdr. It also checks CRC checksum of the read
* volume identifier header. The error codes are the same as in
* 'ubi_io_read_ec_hdr()'.
*
* Note, the implementation of this function is also very similar to
* 'ubi_io_read_ec_hdr()', so refer commentaries in 'ubi_io_read_ec_hdr()'.
*/
int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
struct ubi_vid_hdr *vid_hdr, int verbose)
{
int err, read_err;
uint32_t crc, magic, hdr_crc;
void *p;
dbg_io("read VID header from PEB %d", pnum);
ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
p = (char *)vid_hdr - ubi->vid_hdr_shift;
read_err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
ubi->vid_hdr_alsize);
if (read_err && read_err != UBI_IO_BITFLIPS && !mtd_is_eccerr(read_err))
return read_err;
magic = be32_to_cpu(vid_hdr->magic);
if (magic != UBI_VID_HDR_MAGIC) {
if (mtd_is_eccerr(read_err))
return UBI_IO_BAD_HDR_EBADMSG;
if (ubi_check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) {
if (verbose)
ubi_warn("no VID header found at PEB %d, only 0xFF bytes",
pnum);
dbg_bld("no VID header found at PEB %d, only 0xFF bytes",
pnum);
if (!read_err)
return UBI_IO_FF;
else
return UBI_IO_FF_BITFLIPS;
}
if (verbose) {
ubi_warn("bad magic number at PEB %d: %08x instead of %08x",
pnum, magic, UBI_VID_HDR_MAGIC);
ubi_dump_vid_hdr(vid_hdr);
}
dbg_bld("bad magic number at PEB %d: %08x instead of %08x",
pnum, magic, UBI_VID_HDR_MAGIC);
return UBI_IO_BAD_HDR;
}
crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
if (hdr_crc != crc) {
if (verbose) {
ubi_warn("bad CRC at PEB %d, calculated %#08x, read %#08x",
pnum, crc, hdr_crc);
ubi_dump_vid_hdr(vid_hdr);
}
dbg_bld("bad CRC at PEB %d, calculated %#08x, read %#08x",
pnum, crc, hdr_crc);
if (!read_err)
return UBI_IO_BAD_HDR;
else
return UBI_IO_BAD_HDR_EBADMSG;
}
err = validate_vid_hdr(ubi, vid_hdr);
if (err) {
ubi_err("validation failed for PEB %d", pnum);
return -EINVAL;
}
return read_err ? UBI_IO_BITFLIPS : 0;
}
/**
* ubi_io_read - read data from a physical eraseblock.
* @ubi: UBI device description object
* @buf: buffer where to store the read data
* @pnum: physical eraseblock number to read from
* @offset: offset within the physical eraseblock from where to read
* @len: how many bytes to read
*
* This function reads data from offset @offset of physical eraseblock @pnum
* and stores the read data in the @buf buffer. The following return codes are
* possible:
*
* o %0 if all the requested data were successfully read;
* o %UBI_IO_BITFLIPS if all the requested data were successfully read, but
* correctable bit-flips were detected; this is harmless but may indicate
* that this eraseblock may become bad soon (but do not have to);
* o %-EBADMSG if the MTD subsystem reported about data integrity problems, for
* example it can be an ECC error in case of NAND; this most probably means
* that the data is corrupted;
* o %-EIO if some I/O error occurred;
* o other negative error codes in case of other errors.
*/
int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
int len)
{
int err, retries = 0;
size_t read;
loff_t addr;
dbg_io("read %d bytes from PEB %d:%d", len, pnum, offset);
ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
ubi_assert(offset >= 0 && offset + len <= ubi->peb_size);
ubi_assert(len > 0);
err = self_check_not_bad(ubi, pnum);
if (err)
return err;
/*
* Deliberately corrupt the buffer to improve robustness. Indeed, if we
* do not do this, the following may happen:
* 1. The buffer contains data from previous operation, e.g., read from
* another PEB previously. The data looks like expected, e.g., if we
* just do not read anything and return - the caller would not
* notice this. E.g., if we are reading a VID header, the buffer may
* contain a valid VID header from another PEB.
* 2. The driver is buggy and returns us success or -EBADMSG or
* -EUCLEAN, but it does not actually put any data to the buffer.
*
* This may confuse UBI or upper layers - they may think the buffer
* contains valid data while in fact it is just old data. This is
* especially possible because UBI (and UBIFS) relies on CRC, and
* treats data as correct even in case of ECC errors if the CRC is
* correct.
*
* Try to prevent this situation by changing the first byte of the
* buffer.
*/
*((uint8_t *)buf) ^= 0xFF;
addr = (loff_t)pnum * ubi->peb_size + offset;
retry:
err = mtd_read(ubi->mtd, addr, len, &read, buf);
if (err) {
const char *errstr = mtd_is_eccerr(err) ? " (ECC error)" : "";
if (mtd_is_bitflip(err)) {
/*
* -EUCLEAN is reported if there was a bit-flip which
* was corrected, so this is harmless.
*
* We do not report about it here unless debugging is
* enabled. A corresponding message will be printed
* later, when it is has been scrubbed.
*/
ubi_msg("fixable bit-flip detected at PEB %d", pnum);
ubi_assert(len == read);
return UBI_IO_BITFLIPS;
}
if (retries++ < UBI_IO_RETRIES) {
ubi_warn("error %d%s while reading %d bytes from PEB %d:%d, read only %zd bytes, retry",
err, errstr, len, pnum, offset, read);
yield();
goto retry;
}
ubi_err("error %d%s while reading %d bytes from PEB %d:%d, read %zd bytes",
err, errstr, len, pnum, offset, read);
dump_stack();
/*
* The driver should never return -EBADMSG if it failed to read
* all the requested data. But some buggy drivers might do
* this, so we change it to -EIO.
*/
if (read != len && mtd_is_eccerr(err)) {
#ifndef NO_FREESTYLE
dbg_drv ("_______________ %s ____________ EBADMSG -> EIO", __func__);
#endif
ubi_assert(0);
err = -EIO;
}
} else {
ubi_assert(len == read);
if (ubi_dbg_is_bitflip(ubi)) {
dbg_gen("bit-flip (emulated)");
err = UBI_IO_BITFLIPS;
}
}
return err;
}
/**
* 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_HDR if the erase counter header is corrupted (a CRC error);
* o %UBI_IO_BAD_HDR_EBADMSG is the same as %UBI_IO_BAD_HDR, but there also was
* a data integrity error (uncorrectable ECC error in case of NAND);
* o %UBI_IO_FF if only 0xFF bytes were read (the PEB is supposedly 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;
uint32_t crc, magic, hdr_crc;
dbg_io("read EC header from PEB %d", pnum);
ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
read_err = ubi_io_read(ubi, ec_hdr, pnum, 0, UBI_EC_HDR_SIZE);
if (read_err) {
if (read_err != UBI_IO_BITFLIPS && !mtd_is_eccerr(read_err))
return read_err;
/*
* We read all the data, but either a correctable bit-flip
* occurred, or MTD reported a data integrity error
* (uncorrectable 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, to force scrubbing.
*/
}
magic = be32_to_cpu(ec_hdr->magic);
if (magic != UBI_EC_HDR_MAGIC) {
if (mtd_is_eccerr(read_err))
return UBI_IO_BAD_HDR_EBADMSG;
/*
* The magic field is wrong. Let's check if we have read all
* 0xFF. If yes, this physical eraseblock is assumed to be
* empty.
*/
if (ubi_check_pattern(ec_hdr, 0xFF, UBI_EC_HDR_SIZE)) {
/* The physical eraseblock is supposedly empty */
if (verbose)
ubi_warn("no EC header found at PEB %d, "
"only 0xFF bytes", pnum);
dbg_bld("no EC header found at PEB %d, "
"only 0xFF bytes", pnum);
if (!read_err)
return UBI_IO_FF;
else
return UBI_IO_FF_BITFLIPS;
}
/*
* 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);
}
dbg_bld("bad magic number at PEB %d: %08x instead of "
"%08x", pnum, magic, UBI_EC_HDR_MAGIC);
return UBI_IO_BAD_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);
}
dbg_bld("bad EC header CRC at PEB %d, calculated "
"%#08x, read %#08x", pnum, crc, hdr_crc);
if (!read_err)
return UBI_IO_BAD_HDR;
else
return UBI_IO_BAD_HDR_EBADMSG;
}
/* 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;
}
/*
* If there was %-EBADMSG, but the header CRC is still OK, report about
* a bit-flip to force scrubbing on this PEB.
*/
return read_err ? UBI_IO_BITFLIPS : 0;
}
/**
* ubi_io_read_vid_hdr - read and check a volume identifier header.
* @ubi: UBI device description object
* @pnum: physical eraseblock number to read from
* @vid_hdr: &struct ubi_vid_hdr object where to store the read volume
* identifier header
* @verbose: be verbose if the header is corrupted or wasn't found
*
* This function reads the volume identifier header from physical eraseblock
* @pnum and stores it in @vid_hdr. It also checks CRC checksum of the read
* volume identifier 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;
* o %UBI_IO_BAD_VID_HRD if the volume identifier header is corrupted (a CRC
* error detected);
* o %UBI_IO_PEB_FREE if the physical eraseblock is free (i.e., there is no VID
* header there);
* o a negative error code in case of failure.
*/
int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
struct ubi_vid_hdr *vid_hdr, int verbose)
{
int err, read_err = 0;
uint32_t crc, magic, hdr_crc;
void *p;
dbg_io("read VID header from PEB %d", pnum);
ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
if (UBI_IO_DEBUG)
verbose = 1;
p = (char *)vid_hdr - ubi->vid_hdr_shift;
err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
ubi->vid_hdr_alsize);
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 the read data is corrupted. But we have a
* CRC check-sum and we will identify this. If the VID header is
* still OK, we just report this as there was a bit-flip.
*/
read_err = err;
}
magic = be32_to_cpu(vid_hdr->magic);
if (magic != UBI_VID_HDR_MAGIC) {
/*
* If we have read all 0xFF bytes, the VID header probably does
* not exist and the physical eraseblock is assumed to be free.
*
* But if there was a read error, we do not test the data for
* 0xFFs. Even if it does contain all 0xFFs, this error
* indicates that something is still wrong with this physical
* eraseblock and it cannot be regarded as free.
*/
if (read_err != -EBADMSG &&
check_pattern(vid_hdr, 0xFF, UBI_VID_HDR_SIZE)) {
/* The physical eraseblock is supposedly free */
/*
* 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, ubi->leb_start,
ubi->leb_size);
if (err)
return err > 0 ? UBI_IO_BAD_VID_HDR : err;
if (verbose)
ubi_warn("no VID header found at PEB %d, "
"only 0xFF bytes", pnum);
return UBI_IO_PEB_FREE;
}
/*
* This is not a valid VID 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_VID_HDR_MAGIC);
ubi_dbg_dump_vid_hdr(vid_hdr);
}
return UBI_IO_BAD_VID_HDR;
}
crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_VID_HDR_SIZE_CRC);
hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
if (hdr_crc != crc) {
if (verbose) {
ubi_warn("bad CRC at PEB %d, calculated %#08x, "
"read %#08x", pnum, crc, hdr_crc);
ubi_dbg_dump_vid_hdr(vid_hdr);
}
return UBI_IO_BAD_VID_HDR;
}
/* Validate the VID header that we have just read */
err = validate_vid_hdr(ubi, vid_hdr);
if (err) {
ubi_err("validation failed for PEB %d", pnum);
return -EINVAL;
}
return read_err ? UBI_IO_BITFLIPS : 0;
}
/**
* 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 - write data to a physical eraseblock.
* @ubi: UBI device description object
* @buf: buffer with the data to write
* @pnum: physical eraseblock number to write to
* @offset: offset within the physical eraseblock where to write
* @len: how many bytes to write
*
* This function writes @len bytes of data from buffer @buf to offset @offset
* of physical eraseblock @pnum. If all the data were successfully written,
* zero is returned. If an error occurred, this function returns a negative
* error code. If %-EIO is returned, the physical eraseblock most probably went
* bad.
*
* Note, in case of an error, it is possible that something was still written
* to the flash media, but may be some garbage.
*/
int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
int len)
{
int err;
size_t written;
loff_t addr;
dbg_io("write %d bytes to PEB %d:%d", len, pnum, offset);
ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
ubi_assert(offset >= 0 && offset + len <= ubi->peb_size);
ubi_assert(offset % ubi->hdrs_min_io_size == 0);
ubi_assert(len > 0 && len % ubi->hdrs_min_io_size == 0);
if (ubi->ro_mode) {
ubi_err("read-only mode");
return -EROFS;
}
/* The below has to be compiled out if paranoid checks are disabled */
err = paranoid_check_not_bad(ubi, pnum);
if (err)
return err > 0 ? -EINVAL : err;
/* The area we are writing to has to contain all 0xFF bytes */
err = paranoid_check_all_ff(ubi, pnum, offset, len);
if (err)
return err > 0 ? -EINVAL : err;
if (offset >= ubi->leb_start) {
/*
* We write to the data area of the physical eraseblock. Make
* sure it has valid EC and VID headers.
*/
err = paranoid_check_peb_ec_hdr(ubi, pnum);
if (err)
return err > 0 ? -EINVAL : err;
err = paranoid_check_peb_vid_hdr(ubi, pnum);
if (err)
return err > 0 ? -EINVAL : err;
}
if (ubi_dbg_is_write_failure()) {
dbg_err("cannot write %d bytes to PEB %d:%d "
"(emulated)", len, pnum, offset);
ubi_dbg_dump_stack();
return -EIO;
}
addr = (loff_t)pnum * ubi->peb_size + offset;
err = ubi->mtd->write(ubi->mtd, addr, len, &written, buf);
if (err) {
ubi_err("error %d while writing %d bytes to PEB %d:%d, written"
" %u bytes", err, len, pnum, offset, (unsigned int)written);
ubi_dbg_dump_stack();
} else
ubi_assert(written == len);
return err;
}
/**
* ubi_io_read - read data from a physical eraseblock.
* @ubi: UBI device description object
* @buf: buffer where to store the read data
* @pnum: physical eraseblock number to read from
* @offset: offset within the physical eraseblock from where to read
* @len: how many bytes to read
*
* This function reads data from offset @offset of physical eraseblock @pnum
* and stores the read data in the @buf buffer. The following return codes are
* possible:
*
* o %0 if all the requested data were successfully read;
* o %UBI_IO_BITFLIPS if all the requested data were successfully read, but
* correctable bit-flips were detected; this is harmless but may indicate
* that this eraseblock may become bad soon (but do not have to);
* o %-EBADMSG if the MTD subsystem reported about data integrity problems, for
* example it can be an ECC error in case of NAND; this most probably means
* that the data is corrupted;
* o %-EIO if some I/O error occurred;
* o other negative error codes in case of other errors.
*/
int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
int len)
{
int err, retries = 0;
size_t read;
loff_t addr;
dbg_io("read %d bytes from PEB %d:%d", len, pnum, offset);
ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
ubi_assert(offset >= 0 && offset + len <= ubi->peb_size);
ubi_assert(len > 0);
err = paranoid_check_not_bad(ubi, pnum);
if (err)
return err > 0 ? -EINVAL : err;
addr = (loff_t)pnum * ubi->peb_size + offset;
retry:
err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf);
if (err) {
if (err == -EUCLEAN) {
/*
* -EUCLEAN is reported if there was a bit-flip which
* was corrected, so this is harmless.
*/
ubi_msg("fixable bit-flip detected at PEB %d", pnum);
ubi_assert(len == read);
return UBI_IO_BITFLIPS;
}
if (read != len && retries++ < UBI_IO_RETRIES) {
dbg_io("error %d while reading %d bytes from PEB %d:%d, "
"read only %u bytes, retry",
err, len, pnum, offset, (unsigned int)read);
yield();
goto retry;
}
ubi_err("error %d while reading %d bytes from PEB %d:%d, "
"read %u bytes", err, len, pnum, offset, (unsigned int)read);
ubi_dbg_dump_stack();
/*
* The driver should never return -EBADMSG if it failed to read
* all the requested data. But some buggy drivers might do
* this, so we change it to -EIO.
*/
if (read != len && err == -EBADMSG) {
ubi_assert(0);
printk("%s[%d] not here\n", __func__, __LINE__);
// err = -EIO;
}
} else {
ubi_assert(len == read);
if (ubi_dbg_is_bitflip()) {
dbg_msg("bit-flip (emulated)");
err = UBI_IO_BITFLIPS;
}
}
return err;
}
