/**
* ubi_compare_lebs - find out which logical eraseblock is newer.
* @ubi: UBI device description object
* @aeb: first logical eraseblock to compare
* @pnum: physical eraseblock number of the second logical eraseblock to
* compare
* @vid_hdr: volume identifier header of the second logical eraseblock
*
* This function compares 2 copies of a LEB and informs which one is newer. In
* case of success this function returns a positive value, in case of failure, a
* negative error code is returned. The success return codes use the following
* bits:
* o bit 0 is cleared: the first PEB (described by @aeb) is newer than the
* second PEB (described by @pnum and @vid_hdr);
* o bit 0 is set: the second PEB is newer;
* o bit 1 is cleared: no bit-flips were detected in the newer LEB;
* o bit 1 is set: bit-flips were detected in the newer LEB;
* o bit 2 is cleared: the older LEB is not corrupted;
* o bit 2 is set: the older LEB is corrupted.
*/
int ubi_compare_lebs(struct ubi_device *ubi, const struct ubi_ainf_peb *aeb,
int pnum, const struct ubi_vid_hdr *vid_hdr)
{
int len, err, second_is_newer, bitflips = 0, corrupted = 0;
uint32_t data_crc, crc;
struct ubi_vid_hdr *vh = NULL;
unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
if (sqnum2 == aeb->sqnum) {
/*
* This must be a really ancient UBI image which has been
* created before sequence numbers support has been added. At
* that times we used 32-bit LEB versions stored in logical
* eraseblocks. That was before UBI got into mainline. We do not
* support these images anymore. Well, those images still work,
* but only if no unclean reboots happened.
*/
ubi_err(ubi, "unsupported on-flash UBI format");
return -EINVAL;
}
/* Obviously the LEB with lower sequence counter is older */
second_is_newer = (sqnum2 > aeb->sqnum);
/*
* Now we know which copy is newer. If the copy flag of the PEB with
* newer version is not set, then we just return, otherwise we have to
* check data CRC. For the second PEB we already have the VID header,
* for the first one - we'll need to re-read it from flash.
*
* Note: this may be optimized so that we wouldn't read twice.
*/
if (second_is_newer) {
if (!vid_hdr->copy_flag) {
/* It is not a copy, so it is newer */
dbg_bld("second PEB %d is newer, copy_flag is unset",
pnum);
return 1;
}
} else {
if (!aeb->copy_flag) {
/* It is not a copy, so it is newer */
dbg_bld("first PEB %d is newer, copy_flag is unset",
pnum);
return bitflips << 1;
}
vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
if (!vh)
return -ENOMEM;
pnum = aeb->pnum;
err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
if (err) {
if (err == UBI_IO_BITFLIPS)
bitflips = 1;
else {
ubi_err(ubi, "VID of PEB %d header is bad, but it was OK earlier, err %d",
pnum, err);
if (err > 0)
err = -EIO;
goto out_free_vidh;
}
}
vid_hdr = vh;
}
/* Read the data of the copy and check the CRC */
len = be32_to_cpu(vid_hdr->data_size);
mutex_lock(&ubi->buf_mutex);
err = ubi_io_read_data(ubi, ubi->peb_buf, pnum, 0, len);
if (err && err != UBI_IO_BITFLIPS && !mtd_is_eccerr(err))
goto out_unlock;
data_crc = be32_to_cpu(vid_hdr->data_crc);
crc = crc32(UBI_CRC32_INIT, ubi->peb_buf, len);
if (crc != data_crc) {
dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
pnum, crc, data_crc);
corrupted = 1;
bitflips = 0;
second_is_newer = !second_is_newer;
} else {
dbg_bld("PEB %d CRC is OK", pnum);
bitflips |= !!err;
}
mutex_unlock(&ubi->buf_mutex);
ubi_free_vid_hdr(ubi, vh);
if (second_is_newer)
dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
else
dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
return second_is_newer | (bitflips << 1) | (corrupted << 2);
out_unlock:
mutex_unlock(&ubi->buf_mutex);
out_free_vidh:
ubi_free_vid_hdr(ubi, vh);
return err;
}
/**
* compare_lebs - find out which logical eraseblock is newer.
* @ubi: UBI device description object
* @seb: first logical eraseblock to compare
* @pnum: physical eraseblock number of the second logical eraseblock to
* compare
* @vid_hdr: volume identifier header of the second logical eraseblock
*
* This function compares 2 copies of a LEB and informs which one is newer. In
* case of success this function returns a positive value, in case of failure, a
* negative error code is returned. The success return codes use the following
* bits:
* o bit 0 is cleared: the first PEB (described by @seb) is newer then the
* second PEB (described by @pnum and @vid_hdr);
* o bit 0 is set: the second PEB is newer;
* o bit 1 is cleared: no bit-flips were detected in the newer LEB;
* o bit 1 is set: bit-flips were detected in the newer LEB;
* o bit 2 is cleared: the older LEB is not corrupted;
* o bit 2 is set: the older LEB is corrupted.
*/
static int compare_lebs(struct ubi_device *ubi, const struct ubi_scan_leb *seb,
int pnum, const struct ubi_vid_hdr *vid_hdr)
{
void *buf;
int len, err, second_is_newer, bitflips = 0, corrupted = 0;
uint32_t data_crc, crc;
struct ubi_vid_hdr *vh = NULL;
unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
if (seb->sqnum == 0 && sqnum2 == 0) {
long long abs, v1 = seb->leb_ver, v2 = be32_to_cpu(vid_hdr->leb_ver);
/*
* UBI constantly increases the logical eraseblock version
* number and it can overflow. Thus, we have to bear in mind
* that versions that are close to %0xFFFFFFFF are less then
* versions that are close to %0.
*
* The UBI WL unit guarantees that the number of pending tasks
* is not greater then %0x7FFFFFFF. So, if the difference
* between any two versions is greater or equivalent to
* %0x7FFFFFFF, there was an overflow and the logical
* eraseblock with lower version is actually newer then the one
* with higher version.
*
* FIXME: but this is anyway obsolete and will be removed at
* some point.
*/
dbg_bld("using old crappy leb_ver stuff");
if (v1 == v2) {
ubi_err("PEB %d and PEB %d have the same version %lld",
seb->pnum, pnum, v1);
return -EINVAL;
}
abs = v1 - v2;
if (abs < 0)
abs = -abs;
if (abs < 0x7FFFFFFF)
/* Non-overflow situation */
second_is_newer = (v2 > v1);
else
second_is_newer = (v2 < v1);
} else
/* Obviously the LEB with lower sequence counter is older */
second_is_newer = sqnum2 > seb->sqnum;
/*
* Now we know which copy is newer. If the copy flag of the PEB with
* newer version is not set, then we just return, otherwise we have to
* check data CRC. For the second PEB we already have the VID header,
* for the first one - we'll need to re-read it from flash.
*
* FIXME: this may be optimized so that we wouldn't read twice.
*/
if (second_is_newer) {
if (!vid_hdr->copy_flag) {
/* It is not a copy, so it is newer */
dbg_bld("second PEB %d is newer, copy_flag is unset",
pnum);
return 1;
}
} else {
pnum = seb->pnum;
vh = ubi_zalloc_vid_hdr(ubi, GFP_KERNEL);
if (!vh)
return -ENOMEM;
err = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
if (err) {
if (err == UBI_IO_BITFLIPS)
bitflips = 1;
else {
dbg_err("VID of PEB %d header is bad, but it "
"was OK earlier", pnum);
if (err > 0)
err = -EIO;
goto out_free_vidh;
}
}
if (!vh->copy_flag) {
/* It is not a copy, so it is newer */
dbg_bld("first PEB %d is newer, copy_flag is unset",
pnum);
err = bitflips << 1;
goto out_free_vidh;
}
vid_hdr = vh;
}
/* Read the data of the copy and check the CRC */
len = be32_to_cpu(vid_hdr->data_size);
buf = vmalloc(len);
if (!buf) {
err = -ENOMEM;
goto out_free_vidh;
}
err = ubi_io_read_data(ubi, buf, pnum, 0, len);
if (err && err != UBI_IO_BITFLIPS)
goto out_free_buf;
data_crc = be32_to_cpu(vid_hdr->data_crc);
crc = crc32(UBI_CRC32_INIT, buf, len);
if (crc != data_crc) {
dbg_bld("PEB %d CRC error: calculated %#08x, must be %#08x",
pnum, crc, data_crc);
corrupted = 1;
bitflips = 0;
second_is_newer = !second_is_newer;
} else {
dbg_bld("PEB %d CRC is OK", pnum);
bitflips = !!err;
}
vfree(buf);
ubi_free_vid_hdr(ubi, vh);
if (second_is_newer)
dbg_bld("second PEB %d is newer, copy_flag is set", pnum);
else
dbg_bld("first PEB %d is newer, copy_flag is set", pnum);
return second_is_newer | (bitflips << 1) | (corrupted << 2);
out_free_buf:
vfree(buf);
out_free_vidh:
ubi_free_vid_hdr(ubi, vh);
return err;
}
/**
* nor_erase_prepare - prepare a NOR flash PEB for erasure.
* @ubi: UBI device description object
* @pnum: physical eraseblock number to prepare
*
* NOR flash, or at least some of them, have peculiar embedded PEB erasure
* algorithm: the PEB is first filled with zeroes, then it is erased. And
* filling with zeroes starts from the end of the PEB. This was observed with
* Spansion S29GL512N NOR flash.
*
* This means that in case of a power cut we may end up with intact data at the
* beginning of the PEB, and all zeroes at the end of PEB. In other words, the
* EC and VID headers are OK, but a large chunk of data at the end of PEB is
* zeroed. This makes UBI mistakenly treat this PEB as used and associate it
* with an LEB, which leads to subsequent failures (e.g., UBIFS fails).
*
* This function is called before erasing NOR PEBs and it zeroes out EC and VID
* magic numbers in order to invalidate them and prevent the failures. Returns
* zero in case of success and a negative error code in case of failure.
*/
static int nor_erase_prepare(struct ubi_device *ubi, int pnum)
{
int err, err1;
size_t written;
loff_t addr;
uint32_t data = 0;
/*
* Note, we cannot generally define VID header buffers on stack,
* because of the way we deal with these buffers (see the header
* comment in this file). But we know this is a NOR-specific piece of
* code, so we can do this. But yes, this is error-prone and we should
* (pre-)allocate VID header buffer instead.
*/
struct ubi_vid_hdr vid_hdr;
/*
* It is important to first invalidate the EC header, and then the VID
* header. Otherwise a power cut may lead to valid EC header and
* invalid VID header, in which case UBI will treat this PEB as
* corrupted and will try to preserve it, and print scary warnings.
*/
addr = (loff_t)pnum * ubi->peb_size;
err = mtd_write(ubi->mtd, addr, 4, &written, (void *)&data);
if (!err) {
addr += ubi->vid_hdr_aloffset;
err = mtd_write(ubi->mtd, addr, 4, &written, (void *)&data);
if (!err)
return 0;
}
/*
* We failed to write to the media. This was observed with Spansion
* S29GL512N NOR flash. Most probably the previously eraseblock erasure
* was interrupted at a very inappropriate moment, so it became
* unwritable. In this case we probably anyway have garbage in this
* PEB.
*/
err1 = ubi_io_read_vid_hdr(ubi, pnum, &vid_hdr, 0);
if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR ||
err1 == UBI_IO_FF) {
struct ubi_ec_hdr ec_hdr;
err1 = ubi_io_read_ec_hdr(ubi, pnum, &ec_hdr, 0);
if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR ||
err1 == UBI_IO_FF)
/*
* Both VID and EC headers are corrupted, so we can
* safely erase this PEB and not afraid that it will be
* treated as a valid PEB in case of an unclean reboot.
*/
return 0;
}
/*
* The PEB contains a valid VID header, but we cannot invalidate it.
* Supposedly the flash media or the driver is screwed up, so return an
* error.
*/
ubi_err("cannot invalidate PEB %d, write returned %d read returned %d",
pnum, err, err1);
ubi_dump_flash(ubi, pnum, 0, ubi->peb_size);
return -EIO;
}
static int ubi_scan_fastmap(struct ubi_scan_info *ubi,
struct ubi_attach_info *ai,
int fm_anchor)
{
struct ubi_fm_sb *fmsb, *fmsb2;
struct ubi_vid_hdr *vh;
struct ubi_fastmap_layout *fm;
int i, used_blocks, pnum, ret = 0;
size_t fm_size;
__be32 crc, tmp_crc;
unsigned long long sqnum = 0;
fmsb = &ubi->fm_sb;
fm = &ubi->fm_layout;
ret = ubi_io_read(ubi, fmsb, fm_anchor, ubi->leb_start, sizeof(*fmsb));
if (ret && ret != UBI_IO_BITFLIPS)
goto free_fm_sb;
else if (ret == UBI_IO_BITFLIPS)
fm->to_be_tortured[0] = 1;
if (be32_to_cpu(fmsb->magic) != UBI_FM_SB_MAGIC) {
ubi_err("bad super block magic: 0x%x, expected: 0x%x",
be32_to_cpu(fmsb->magic), UBI_FM_SB_MAGIC);
ret = UBI_BAD_FASTMAP;
goto free_fm_sb;
}
if (fmsb->version != UBI_FM_FMT_VERSION) {
ubi_err("bad fastmap version: %i, expected: %i",
fmsb->version, UBI_FM_FMT_VERSION);
ret = UBI_BAD_FASTMAP;
goto free_fm_sb;
}
used_blocks = be32_to_cpu(fmsb->used_blocks);
if (used_blocks > UBI_FM_MAX_BLOCKS || used_blocks < 1) {
ubi_err("number of fastmap blocks is invalid: %i", used_blocks);
ret = UBI_BAD_FASTMAP;
goto free_fm_sb;
}
fm_size = ubi->leb_size * used_blocks;
if (fm_size != ubi->fm_size) {
ubi_err("bad fastmap size: %zi, expected: %zi", fm_size,
ubi->fm_size);
ret = UBI_BAD_FASTMAP;
goto free_fm_sb;
}
vh = &ubi->fm_vh;
for (i = 0; i < used_blocks; i++) {
pnum = be32_to_cpu(fmsb->block_loc[i]);
if (ubi_io_is_bad(ubi, pnum)) {
ret = UBI_BAD_FASTMAP;
goto free_hdr;
}
#ifdef LATER
int image_seq;
ret = ubi_io_read_ec_hdr(ubi, pnum, ech, 0);
if (ret && ret != UBI_IO_BITFLIPS) {
ubi_err("unable to read fastmap block# %i EC (PEB: %i)",
i, pnum);
if (ret > 0)
ret = UBI_BAD_FASTMAP;
goto free_hdr;
} else if (ret == UBI_IO_BITFLIPS)
fm->to_be_tortured[i] = 1;
image_seq = be32_to_cpu(ech->image_seq);
if (!ubi->image_seq)
ubi->image_seq = image_seq;
/*
* Older UBI implementations have image_seq set to zero, so
* we shouldn't fail if image_seq == 0.
*/
if (image_seq && (image_seq != ubi->image_seq)) {
ubi_err("wrong image seq:%d instead of %d",
be32_to_cpu(ech->image_seq), ubi->image_seq);
ret = UBI_BAD_FASTMAP;
goto free_hdr;
}
#endif
ret = ubi_io_read_vid_hdr(ubi, pnum, vh, 0);
if (ret && ret != UBI_IO_BITFLIPS) {
ubi_err("unable to read fastmap block# %i (PEB: %i)",
i, pnum);
goto free_hdr;
}
/*
* Mainline code rescans the anchor header. We've done
* that already so we merily copy it over.
*/
if (pnum == fm_anchor)
memcpy(vh, ubi->blockinfo + pnum, sizeof(*fm));
if (i == 0) {
if (be32_to_cpu(vh->vol_id) != UBI_FM_SB_VOLUME_ID) {
ubi_err("bad fastmap anchor vol_id: 0x%x," \
" expected: 0x%x",
be32_to_cpu(vh->vol_id),
UBI_FM_SB_VOLUME_ID);
ret = UBI_BAD_FASTMAP;
goto free_hdr;
}
} else {
if (be32_to_cpu(vh->vol_id) != UBI_FM_DATA_VOLUME_ID) {
ubi_err("bad fastmap data vol_id: 0x%x," \
" expected: 0x%x",
be32_to_cpu(vh->vol_id),
UBI_FM_DATA_VOLUME_ID);
ret = UBI_BAD_FASTMAP;
goto free_hdr;
}
}
if (sqnum < be64_to_cpu(vh->sqnum))
sqnum = be64_to_cpu(vh->sqnum);
ret = ubi_io_read(ubi, ubi->fm_buf + (ubi->leb_size * i), pnum,
ubi->leb_start, ubi->leb_size);
if (ret && ret != UBI_IO_BITFLIPS) {
ubi_err("unable to read fastmap block# %i (PEB: %i, " \
"err: %i)", i, pnum, ret);
goto free_hdr;
}
}
fmsb2 = (struct ubi_fm_sb *)(ubi->fm_buf);
tmp_crc = be32_to_cpu(fmsb2->data_crc);
fmsb2->data_crc = 0;
crc = crc32(UBI_CRC32_INIT, ubi->fm_buf, fm_size);
if (crc != tmp_crc) {
ubi_err("fastmap data CRC is invalid");
ubi_err("CRC should be: 0x%x, calc: 0x%x", tmp_crc, crc);
ret = UBI_BAD_FASTMAP;
goto free_hdr;
}
fmsb2->sqnum = sqnum;
fm->used_blocks = used_blocks;
ret = ubi_attach_fastmap(ubi, ai, fm);
if (ret) {
if (ret > 0)
ret = UBI_BAD_FASTMAP;
goto free_hdr;
}
ubi->fm = fm;
ubi->fm_pool.max_size = ubi->fm->max_pool_size;
ubi->fm_wl_pool.max_size = ubi->fm->max_wl_pool_size;
ubi_msg("attached by fastmap %uMB %u blocks",
ubi->fsize_mb, ubi->peb_count);
ubi_dbg("fastmap pool size: %d", ubi->fm_pool.max_size);
ubi_dbg("fastmap WL pool size: %d", ubi->fm_wl_pool.max_size);
out:
if (ret)
ubi_err("Attach by fastmap failed, doing a full scan!");
return ret;
free_hdr:
free_fm_sb:
goto out;
}
/**
* ubi_eba_read_leb - read data.
* @ubi: UBI device description object
* @vol: volume description object
* @lnum: logical eraseblock number
* @buf: buffer to store the read data
* @offset: offset from where to read
* @len: how many bytes to read
* @check: data CRC check flag
*
* If the logical eraseblock @lnum is unmapped, @buf is filled with 0xFF
* bytes. The @check flag only makes sense for static volumes and forces
* eraseblock data CRC checking.
*
* In case of success this function returns zero. In case of a static volume,
* if data CRC mismatches - %-EBADMSG is returned. %-EBADMSG may also be
* returned for any volume type if an ECC error was detected by the MTD device
* driver. Other negative error cored may be returned in case of other errors.
*/
int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
void *buf, int offset, int len, int check)
{
int err, pnum, scrub = 0, vol_id = vol->vol_id;
struct ubi_vid_hdr *vid_hdr;
uint32_t uninitialized_var(crc);
err = leb_read_lock(ubi, vol_id, lnum);
if (err)
return err;
pnum = vol->eba_tbl[lnum];
if (pnum < 0) {
/*
* The logical eraseblock is not mapped, fill the whole buffer
* with 0xFF bytes. The exception is static volumes for which
* it is an error to read unmapped logical eraseblocks.
*/
dbg_eba("read %d bytes from offset %d of LEB %d:%d (unmapped)",
len, offset, vol_id, lnum);
leb_read_unlock(ubi, vol_id, lnum);
ubi_assert(vol->vol_type != UBI_STATIC_VOLUME);
memset(buf, 0xFF, len);
return 0;
}
dbg_eba("read %d bytes from offset %d of LEB %d:%d, PEB %d",
len, offset, vol_id, lnum, pnum);
if (vol->vol_type == UBI_DYNAMIC_VOLUME)
check = 0;
retry:
if (check) {
vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
if (!vid_hdr) {
err = -ENOMEM;
goto out_unlock;
}
err = ubi_io_read_vid_hdr(ubi, pnum, vid_hdr, 1);
if (err && err != UBI_IO_BITFLIPS) {
if (err > 0) {
/*
* The header is either absent or corrupted.
* The former case means there is a bug -
* switch to read-only mode just in case.
* The latter case means a real corruption - we
* may try to recover data. FIXME: but this is
* not implemented.
*/
<<<<<<< HEAD
if (err == UBI_IO_BAD_HDR_EBADMSG ||
err == UBI_IO_BAD_HDR) {
=======
if (err == UBI_IO_BAD_VID_HDR) {
>>>>>>> 296c66da8a02d52243f45b80521febece5ed498a
ubi_warn("corrupted VID header at PEB "
"%d, LEB %d:%d", pnum, vol_id,
lnum);
err = -EBADMSG;
} else
ubi_ro_mode(ubi);
}
