/**
* self_check_vid_hdr - check that a volume identifier header is all right.
* @ubi: UBI device description object
* @pnum: physical eraseblock number the volume identifier header belongs to
* @vid_hdr: the volume identifier header to check
*
* This function returns zero if the volume identifier header is all right, and
* %-EINVAL if not.
*/
static int self_check_vid_hdr(const struct ubi_device *ubi, int pnum,
const struct ubi_vid_hdr *vid_hdr)
{
int err;
uint32_t magic;
if (!ubi_dbg_chk_io(ubi))
return 0;
magic = be32_to_cpu(vid_hdr->magic);
if (magic != UBI_VID_HDR_MAGIC) {
ubi_err(ubi, "bad VID header magic %#08x at PEB %d, must be %#08x",
magic, pnum, UBI_VID_HDR_MAGIC);
goto fail;
}
err = validate_vid_hdr(ubi, vid_hdr);
if (err) {
ubi_err(ubi, "self-check failed for PEB %d", pnum);
goto fail;
}
return err;
fail:
ubi_err(ubi, "self-check failed for PEB %d", pnum);
ubi_dump_vid_hdr(vid_hdr);
dump_stack();
return -EINVAL;
}
/**
* validate_vid_hdr - check volume identifier header.
* @ubi: UBI device description object
* @vid_hdr: the volume identifier header to check
* @av: information about the volume this logical eraseblock belongs to
* @pnum: physical eraseblock number the VID header came from
*
* This function checks that data stored in @vid_hdr is consistent. Returns
* non-zero if an inconsistency was found and zero if not.
*
* Note, UBI does sanity check of everything it reads from the flash media.
* Most of the checks are done in the I/O sub-system. Here we check that the
* information in the VID header is consistent to the information in other VID
* headers of the same volume.
*/
static int validate_vid_hdr(const struct ubi_device *ubi,
const struct ubi_vid_hdr *vid_hdr,
const struct ubi_ainf_volume *av, int pnum)
{
int vol_type = vid_hdr->vol_type;
int vol_id = be32_to_cpu(vid_hdr->vol_id);
int used_ebs = be32_to_cpu(vid_hdr->used_ebs);
int data_pad = be32_to_cpu(vid_hdr->data_pad);
if (av->leb_count != 0) {
int av_vol_type;
/*
* This is not the first logical eraseblock belonging to this
* volume. Ensure that the data in its VID header is consistent
* to the data in previous logical eraseblock headers.
*/
if (vol_id != av->vol_id) {
ubi_err(ubi, "inconsistent vol_id");
goto bad;
}
if (av->vol_type == UBI_STATIC_VOLUME)
av_vol_type = UBI_VID_STATIC;
else
av_vol_type = UBI_VID_DYNAMIC;
if (vol_type != av_vol_type) {
ubi_err(ubi, "inconsistent vol_type");
goto bad;
}
if (used_ebs != av->used_ebs) {
ubi_err(ubi, "inconsistent used_ebs");
goto bad;
}
if (data_pad != av->data_pad) {
ubi_err(ubi, "inconsistent data_pad");
goto bad;
}
}
return 0;
bad:
ubi_err(ubi, "inconsistent VID header at PEB %d", pnum);
ubi_dump_vid_hdr(vid_hdr);
ubi_dump_av(av);
return -EINVAL;
}
/**
* self_check_peb_vid_hdr - check volume identifier header.
* @ubi: UBI device description object
* @pnum: the physical eraseblock number to check
*
* This function returns zero if the volume identifier header is all right,
* and a negative error code if not or if an error occurred.
*/
static int self_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum)
{
int err;
uint32_t crc, hdr_crc;
struct ubi_vid_io_buf *vidb;
struct ubi_vid_hdr *vid_hdr;
void *p;
if (!ubi_dbg_chk_io(ubi))
return 0;
vidb = ubi_alloc_vid_buf(ubi, GFP_NOFS);
if (!vidb)
return -ENOMEM;
vid_hdr = ubi_get_vid_hdr(vidb);
p = vidb->buffer;
err = ubi_io_read(ubi, p, pnum, ubi->vid_hdr_aloffset,
ubi->vid_hdr_alsize);
if (err && err != UBI_IO_BITFLIPS && !mtd_is_eccerr(err))
goto exit;
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) {
ubi_err(ubi, "bad VID header CRC at PEB %d, calculated %#08x, read %#08x",
pnum, crc, hdr_crc);
ubi_err(ubi, "self-check failed for PEB %d", pnum);
ubi_dump_vid_hdr(vid_hdr);
dump_stack();
err = -EINVAL;
goto exit;
}
err = self_check_vid_hdr(ubi, pnum, vid_hdr);
exit:
ubi_free_vid_buf(vidb);
return err;
}
/**
* ubi_add_to_av - add used physical eraseblock to the attaching information.
* @ubi: UBI device description object
* @ai: attaching information
* @pnum: the physical eraseblock number
* @ec: erase counter
* @vid_hdr: the volume identifier header
* @bitflips: if bit-flips were detected when this physical eraseblock was read
*
* This function adds information about a used physical eraseblock to the
* 'used' tree of the corresponding volume. The function is rather complex
* because it has to handle cases when this is not the first physical
* eraseblock belonging to the same logical eraseblock, and the newer one has
* to be picked, while the older one has to be dropped. This function returns
* zero in case of success and a negative error code in case of failure.
*/
int ubi_add_to_av(struct ubi_device *ubi, struct ubi_attach_info *ai, int pnum,
int ec, const struct ubi_vid_hdr *vid_hdr, int bitflips)
{
int err, vol_id, lnum;
unsigned long long sqnum;
struct ubi_ainf_volume *av;
struct ubi_ainf_peb *aeb;
struct rb_node **p, *parent = NULL;
vol_id = be32_to_cpu(vid_hdr->vol_id);
lnum = be32_to_cpu(vid_hdr->lnum);
sqnum = be64_to_cpu(vid_hdr->sqnum);
dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, bitflips %d",
pnum, vol_id, lnum, ec, sqnum, bitflips);
av = add_volume(ai, vol_id, pnum, vid_hdr);
if (IS_ERR(av))
return PTR_ERR(av);
if (ai->max_sqnum < sqnum)
ai->max_sqnum = sqnum;
/*
* Walk the RB-tree of logical eraseblocks of volume @vol_id to look
* if this is the first instance of this logical eraseblock or not.
*/
p = &av->root.rb_node;
while (*p) {
int cmp_res;
parent = *p;
aeb = rb_entry(parent, struct ubi_ainf_peb, u.rb);
if (lnum != aeb->lnum) {
if (lnum < aeb->lnum)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
continue;
}
/*
* There is already a physical eraseblock describing the same
* logical eraseblock present.
*/
dbg_bld("this LEB already exists: PEB %d, sqnum %llu, EC %d",
aeb->pnum, aeb->sqnum, aeb->ec);
/*
* Make sure that the logical eraseblocks have different
* sequence numbers. Otherwise the image is bad.
*
* However, if the sequence number is zero, we assume it must
* be an ancient UBI image from the era when UBI did not have
* sequence numbers. We still can attach these images, unless
* there is a need to distinguish between old and new
* eraseblocks, in which case we'll refuse the image in
* 'ubi_compare_lebs()'. In other words, we attach old clean
* images, but refuse attaching old images with duplicated
* logical eraseblocks because there was an unclean reboot.
*/
if (aeb->sqnum == sqnum && sqnum != 0) {
ubi_err("two LEBs with same sequence number %llu",
sqnum);
ubi_dump_aeb(aeb, 0);
ubi_dump_vid_hdr(vid_hdr);
return -EINVAL;
}
/*
* Now we have to drop the older one and preserve the newer
* one.
*/
cmp_res = ubi_compare_lebs(ubi, aeb, pnum, vid_hdr);
if (cmp_res < 0)
return cmp_res;
if (cmp_res & 1) {
/*
* This logical eraseblock is newer than the one
* found earlier.
*/
err = validate_vid_hdr(vid_hdr, av, pnum);
if (err)
return err;
err = add_to_list(ai, aeb->pnum, aeb->vol_id,
aeb->lnum, aeb->ec, cmp_res & 4,
&ai->erase);
if (err)
return err;
aeb->ec = ec;
aeb->pnum = pnum;
aeb->vol_id = vol_id;
aeb->lnum = lnum;
aeb->scrub = ((cmp_res & 2) || bitflips);
aeb->copy_flag = vid_hdr->copy_flag;
aeb->sqnum = sqnum;
if (av->highest_lnum == lnum)
av->last_data_size =
be32_to_cpu(vid_hdr->data_size);
return 0;
} else {
/*
* This logical eraseblock is older than the one found
* previously.
*/
return add_to_list(ai, pnum, vol_id, lnum, ec,
cmp_res & 4, &ai->erase);
}
}
/*
* We've met this logical eraseblock for the first time, add it to the
* attaching information.
*/
err = validate_vid_hdr(vid_hdr, av, pnum);
if (err)
return err;
aeb = kzalloc(sizeof(*aeb), GFP_KERNEL);
if (!aeb)
return -ENOMEM;
aeb->ec = ec;
aeb->pnum = pnum;
aeb->vol_id = vol_id;
aeb->lnum = lnum;
aeb->scrub = bitflips;
aeb->copy_flag = vid_hdr->copy_flag;
aeb->sqnum = sqnum;
if (av->highest_lnum <= lnum) {
av->highest_lnum = lnum;
av->last_data_size = be32_to_cpu(vid_hdr->data_size);
}
av->leb_count += 1;
rb_link_node(&aeb->u.rb, parent, p);
rb_insert_color(&aeb->u.rb, &av->root);
return 0;
}
/**
* 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) {
ubi_err(ubi, "bad copy_flag");
goto bad;
}
if (vol_id < 0 || lnum < 0 || data_size < 0 || used_ebs < 0 ||
data_pad < 0) {
ubi_err(ubi, "negative values");
goto bad;
}
if (vol_id >= UBI_MAX_VOLUMES && vol_id < UBI_INTERNAL_VOL_START) {
ubi_err(ubi, "bad vol_id");
goto bad;
}
if (vol_id < UBI_INTERNAL_VOL_START && compat != 0) {
ubi_err(ubi, "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) {
ubi_err(ubi, "bad compat");
goto bad;
}
if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) {
ubi_err(ubi, "bad vol_type");
goto bad;
}
if (data_pad >= ubi->leb_size / 2) {
ubi_err(ubi, "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) {
ubi_err(ubi, "zero used_ebs");
goto bad;
}
if (data_size == 0) {
ubi_err(ubi, "zero data_size");
goto bad;
}
if (lnum < used_ebs - 1) {
if (data_size != usable_leb_size) {
ubi_err(ubi, "bad data_size");
goto bad;
}
} else if (lnum == used_ebs - 1) {
if (data_size == 0) {
ubi_err(ubi, "bad data_size at last LEB");
goto bad;
}
} else {
ubi_err(ubi, "too high lnum");
goto bad;
}
} else {
if (copy_flag == 0) {
if (data_crc != 0) {
ubi_err(ubi, "non-zero data CRC");
goto bad;
}
if (data_size != 0) {
ubi_err(ubi, "non-zero data_size");
goto bad;
}
} else {
if (data_size == 0) {
ubi_err(ubi, "zero data_size of copy");
goto bad;
}
}
if (used_ebs != 0) {
ubi_err(ubi, "bad used_ebs");
goto bad;
}
}
return 0;
bad:
ubi_err(ubi, "bad VID header");
ubi_dump_vid_hdr(vid_hdr);
dump_stack();
return 1;
}
/**
* 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(ubi, "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(ubi, "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(ubi, "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(ubi, "validation failed for PEB %d", pnum);
return -EINVAL;
}
return read_err ? UBI_IO_BITFLIPS : 0;
}
