/**
* 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;
}
int
sysfs_read_data(const char *file, void *buf, int len)
{
int fd;
ssize_t rd;
fd = open(file, O_RDONLY);
if (fd == -1) {
ubi_err("cannot open file %s", file);
return -1;
}
rd = read(fd, buf, len);
if (rd == -1)
ubi_err("cannot read file %s", file);
close(fd);
return rd;
}
/**
* 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(ubi, "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(ubi, "cannot mark PEB %d bad, error %d", pnum, err);
return err;
}
/**
* ubi_remove_volume - remove volume.
* @desc: volume descriptor
* @no_vtbl: do not change volume table if not zero
*
* This function removes volume described by @desc. The volume has to be opened
* in "exclusive" mode. Returns zero in case of success and a negative error
* code in case of failure. The caller has to have the @ubi->device_mutex
* locked.
*/
int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl)
{
struct ubi_volume *vol = desc->vol;
struct ubi_device *ubi = vol->ubi;
int i, err, vol_id = vol->vol_id, reserved_pebs = vol->reserved_pebs;
dbg_gen("remove device %d, volume %d", ubi->ubi_num, vol_id);
ubi_assert(desc->mode == UBI_EXCLUSIVE);
ubi_assert(vol == ubi->volumes[vol_id]);
if (ubi->ro_mode)
return -EROFS;
if (vol->ref_count > 1) {
/*
* The volume is busy, probably someone is reading one of its
* sysfs files.
*/
err = -EBUSY;
goto out_unlock;
}
ubi->volumes[vol_id] = NULL;
if (!no_vtbl) {
err = ubi_change_vtbl_record(ubi, vol_id, NULL);
if (err)
goto out_err;
}
for (i = 0; i < vol->reserved_pebs; i++) {
err = ubi_eba_unmap_leb(ubi, vol, i);
if (err)
goto out_err;
}
devfs_remove(&vol->cdev);
ubi->rsvd_pebs -= reserved_pebs;
ubi->avail_pebs += reserved_pebs;
ubi_update_reserved(ubi);
ubi->vol_count -= 1;
ubi_volume_notify(ubi, vol, UBI_VOLUME_REMOVED);
if (!no_vtbl)
self_check_volumes(ubi);
return err;
out_err:
ubi_err("cannot remove volume %d, error %d", vol_id, err);
ubi->volumes[vol_id] = vol;
out_unlock:
return err;
}
/**
* uif_init - initialize user interfaces for an UBI device.
* @ubi: UBI device description object
* @ref: set to %1 on exit in case of failure if a reference to @ubi->dev was
* taken, otherwise set to %0
*
* This function initializes various user interfaces for an UBI device. If the
* initialization fails at an early stage, this function frees all the
* resources it allocated, returns an error, and @ref is set to %0. However,
* if the initialization fails after the UBI device was registered in the
* driver core subsystem, this function takes a reference to @ubi->dev, because
* otherwise the release function ('dev_release()') would free whole @ubi
* object. The @ref argument is set to %1 in this case. The caller has to put
* this reference.
*
* This function returns zero in case of success and a negative error code in
* case of failure.
*/
static int uif_init(struct ubi_device *ubi, int *ref)
{
int i, err;
*ref = 0;
sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
sprintf(ubi->dev.name, "ubi");
ubi->dev.id = DEVICE_ID_DYNAMIC;
ubi->dev.parent = &ubi->mtd->class_dev;
err = register_device(&ubi->dev);
if (err)
goto out_unreg;
err = ubi_cdev_add(ubi);
if (err) {
ubi_err("cannot add character device");
goto out_dev;
}
for (i = 0; i < ubi->vtbl_slots; i++)
if (ubi->volumes[i]) {
err = ubi_add_volume(ubi, ubi->volumes[i]);
if (err) {
ubi_err("cannot add volume %d", i);
goto out_volumes;
}
}
return 0;
out_volumes:
kill_volumes(ubi);
devfs_remove(&ubi->cdev);
out_dev:
unregister_device(&ubi->dev);
out_unreg:
ubi_err("cannot initialize UBI %s, error %d", ubi->ubi_name, err);
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;
size_t written;
loff_t addr;
uint32_t data = 0;
struct ubi_ec_hdr ec_hdr;
/*
* 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;
/*
* If VID or EC is valid, we have to corrupt them before erasing.
* 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 = ubi_io_read_ec_hdr(ubi, pnum, &ec_hdr, 0);
if (err != UBI_IO_BAD_HDR_EBADMSG && err != UBI_IO_BAD_HDR &&
err != UBI_IO_FF){
err = mtd_write(ubi->mtd, addr, 4, &written, (void *)&data);
if(err)
goto error;
}
err = ubi_io_read_vid_hdr(ubi, pnum, &vid_hdr, 0);
if (err != UBI_IO_BAD_HDR_EBADMSG && err != UBI_IO_BAD_HDR &&
err != UBI_IO_FF){
addr += ubi->vid_hdr_aloffset;
err = mtd_write(ubi->mtd, addr, 4, &written, (void *)&data);
if (err)
goto error;
}
return 0;
error:
/*
* The PEB contains a valid VID or EC header, but we cannot invalidate
* it. Supposedly the flash media or the driver is screwed up, so
* return an error.
*/
ubi_err(ubi, "cannot invalidate PEB %d, write returned %d", pnum, err);
ubi_dump_flash(ubi, pnum, 0, ubi->peb_size);
return -EIO;
}
/**
* 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 %zd bytes, retry",
err, len, pnum, offset, read);
yield();
goto retry;
}
ubi_err("error %d while reading %d bytes from PEB %d:%d, "
"read %zd bytes", err, len, pnum, offset, read);
ubi_dbg_dump_stack();
} else {
ubi_assert(len == read);
if (ubi_dbg_is_bitflip()) {
dbg_msg("bit-flip (emulated)");
err = UBI_IO_BITFLIPS;
}
}
return err;
}
/**
* paranoid_check_not_bad - ensure that a physical eraseblock is not bad.
* @ubi: UBI device description object
* @pnum: physical eraseblock number to check
*
* This function returns zero if the physical eraseblock is good, %-EINVAL if
* it is bad and a negative error code if an error occurred.
*/
static int paranoid_check_not_bad(const struct ubi_device *ubi, int pnum)
{
int err;
err = ubi_io_is_bad(ubi, pnum);
if (!err)
return err;
ubi_err("paranoid check failed for PEB %d", pnum);
ubi_dbg_dump_stack();
return err > 0 ? -EINVAL : err;
}
static int ubi_remove_vol(char *volume)
{
int err, reserved_pebs, i;
struct ubi_volume *vol;
vol = ubi_find_volume(volume);
if (vol == NULL)
return ENODEV;
printf("Remove UBI volume %s (id %d)\n", vol->name, vol->vol_id);
if (ubi->ro_mode) {
printf("It's read-only mode\n");
err = EROFS;
goto out_err;
}
err = ubi_change_vtbl_record(ubi, vol->vol_id, NULL);
if (err) {
printf("Error changing Vol tabel record err=%x\n", err);
goto out_err;
}
reserved_pebs = vol->reserved_pebs;
for (i = 0; i < vol->reserved_pebs; i++) {
err = ubi_eba_unmap_leb(ubi, vol, i);
if (err)
goto out_err;
}
kfree(vol->eba_tbl);
ubi->volumes[vol->vol_id]->eba_tbl = NULL;
ubi->volumes[vol->vol_id] = NULL;
ubi->rsvd_pebs -= reserved_pebs;
ubi->avail_pebs += reserved_pebs;
i = ubi->beb_rsvd_level - ubi->beb_rsvd_pebs;
if (i > 0) {
i = ubi->avail_pebs >= i ? i : ubi->avail_pebs;
ubi->avail_pebs -= i;
ubi->rsvd_pebs += i;
ubi->beb_rsvd_pebs += i;
if (i > 0)
ubi_msg("reserve more %d PEBs", i);
}
ubi->vol_count -= 1;
return 0;
out_err:
ubi_err(ubi, "cannot remove volume %s, error %d", volume, err);
if (err < 0)
err = -err;
return err;
}
/**
* 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_debugfs_init - create UBI debugfs directory.
*
* Create UBI debugfs directory. Returns zero in case of success and a negative
* error code in case of failure.
*/
int ubi_debugfs_init(void)
{
dfs_rootdir = debugfs_create_dir("ubi", NULL);
if (IS_ERR_OR_NULL(dfs_rootdir)) {
int err = dfs_rootdir ? -ENODEV : PTR_ERR(dfs_rootdir);
ubi_err("cannot create \"ubi\" debugfs directory, error %d\n",
err);
return err;
}
return 0;
}
/**
* validate_vid_hdr - check volume identifier header.
* @vid_hdr: the volume identifier header to check
* @sv: 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_vid_hdr *vid_hdr,
const struct ubi_scan_volume *sv, 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 (sv->leb_count != 0) {
int sv_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 != sv->vol_id) {
dbg_err("inconsistent vol_id");
goto bad;
}
if (sv->vol_type == UBI_STATIC_VOLUME)
sv_vol_type = UBI_VID_STATIC;
else
sv_vol_type = UBI_VID_DYNAMIC;
if (vol_type != sv_vol_type) {
dbg_err("inconsistent vol_type");
goto bad;
}
if (used_ebs != sv->used_ebs) {
dbg_err("inconsistent used_ebs");
goto bad;
}
if (data_pad != sv->data_pad) {
dbg_err("inconsistent data_pad");
goto bad;
}
}
return 0;
bad:
ubi_err("inconsistent VID header at PEB %d", pnum);
ubi_dbg_dump_vid_hdr(vid_hdr);
ubi_dbg_dump_sv(sv);
return -EINVAL;
}
/**
* paranoid_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 paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum)
{
int err;
uint32_t crc, hdr_crc;
struct ubi_vid_hdr *vid_hdr;
void *p;
if (!ubi->dbg->chk_io)
return 0;
vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
if (!vid_hdr)
return -ENOMEM;
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 && err != UBI_IO_BITFLIPS && !mtd_is_eccerr(err))
goto exit;
crc = crc32(UBI_CRC32_INIT, vid_hdr, UBI_EC_HDR_SIZE_CRC);
hdr_crc = be32_to_cpu(vid_hdr->hdr_crc);
if (hdr_crc != crc) {
ubi_err("bad VID header CRC at PEB %d, calculated %#08x, "
"read %#08x", pnum, crc, hdr_crc);
ubi_err("paranoid check failed for PEB %d", pnum);
ubi_dbg_dump_vid_hdr(vid_hdr);
ubi_dbg_dump_stack();
err = -EINVAL;
goto exit;
}
err = paranoid_check_vid_hdr(ubi, pnum, vid_hdr);
exit:
ubi_free_vid_hdr(ubi, vid_hdr);
return err;
}
static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
size_t count, loff_t *offp)
{
int err = 0;
struct ubi_volume_desc *desc = file->private_data;
struct ubi_volume *vol = desc->vol;
struct ubi_device *ubi = vol->ubi;
if (!vol->updating && !vol->changing_leb)
return vol_cdev_direct_write(file, buf, count, offp);
if (vol->updating)
err = ubi_more_update_data(ubi, vol, buf, count);
else
err = ubi_more_leb_change_data(ubi, vol, buf, count);
if (err < 0) {
ubi_err("cannot accept more %zd bytes of data, error %d",
count, err);
return err;
}
if (err) {
/*
* The operation is finished, @err contains number of actually
* written bytes.
*/
count = err;
if (vol->changing_leb) {
revoke_exclusive(desc, UBI_READWRITE);
return count;
}
err = ubi_check_volume(ubi, vol->vol_id);
if (err < 0)
return err;
if (err) {
ubi_warn("volume %d on UBI device %d is corrupted",
vol->vol_id, ubi->ubi_num);
vol->corrupted = 1;
}
vol->checked = 1;
ubi_gluebi_updated(vol);
revoke_exclusive(desc, UBI_READWRITE);
}
return count;
}
/**
* self_check_not_bad - ensure that a physical eraseblock is not bad.
* @ubi: UBI device description object
* @pnum: physical eraseblock number to check
*
* This function returns zero if the physical eraseblock is good, %-EINVAL if
* it is bad and a negative error code if an error occurred.
*/
static int self_check_not_bad(const struct ubi_device *ubi, int pnum)
{
int err;
if (!ubi_dbg_chk_io(ubi))
return 0;
err = ubi_io_is_bad(ubi, pnum);
if (!err)
return err;
ubi_err(ubi, "self-check failed for PEB %d", pnum);
dump_stack();
return err > 0 ? -EINVAL : err;
}
/**
* paranoid_check_all_ff - check that a region of flash is empty.
* @ubi: UBI device description object
* @pnum: the physical eraseblock number to check
* @offset: the starting offset within the physical eraseblock to check
* @len: the length of the region to check
*
* This function returns zero if only 0xFF bytes are present at offset
* @offset of the physical eraseblock @pnum, %1 if not, and a negative error
* code if an error occurred.
*/
static int paranoid_check_all_ff(struct ubi_device *ubi, int pnum, int offset,
int len)
{
size_t read;
int err;
loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
mutex_lock(&ubi->dbg_buf_mutex);
err = ubi->mtd->read(ubi->mtd, addr, len, &read, ubi->dbg_peb_buf);
if (err && err != -EUCLEAN) {
ubi_err("error %d while reading %d bytes from PEB %d:%d, "
"read %zd bytes", err, len, pnum, offset, read);
goto error;
}
err = check_pattern(ubi->dbg_peb_buf, 0xFF, len);
if (err == 0) {
ubi_err("flash region at PEB %d:%d, length %d does not "
"contain all 0xFF bytes", pnum, offset, len);
goto fail;
}
mutex_unlock(&ubi->dbg_buf_mutex);
return 0;
fail:
ubi_err("paranoid check failed for PEB %d", pnum);
dbg_msg("hex dump of the %d-%d region", offset, offset + len);
print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
ubi->dbg_peb_buf, len, 1);
err = 1;
error:
ubi_dbg_dump_stack();
mutex_unlock(&ubi->dbg_buf_mutex);
return err;
}
/* Read one page with oob one time */
int ubi_io_read_oob(const struct ubi_device *ubi, void *databuf, void *oobbuf,
int pnum, int offset)
{
int err;
loff_t addr;
struct mtd_oob_ops ops;
dbg_io("read from PEB %d:%d", pnum, offset);
ubi_assert(pnum >= 0 && pnum < ubi->peb_count);
ubi_assert(offset >= 0 && offset + ubi->mtd->writesize <= ubi->peb_size);
addr = (loff_t)pnum * ubi->peb_size + offset;
ops.mode = MTD_OPS_AUTO_OOB;
ops.ooblen = ubi->mtd->oobavail;
ops.oobbuf = oobbuf;
ops.ooboffs = 0;
ops.len = ubi->mtd->writesize;
ops.datbuf = databuf;
ops.retlen = ops.oobretlen = 0;
err = mtd_read_oob(ubi->mtd, addr, &ops);
if (err) {
if (err == -EUCLEAN) {
/*
* -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 addr %lld", addr);
if(oobbuf)
ubi_assert(ops.oobretlen == ops.ooblen);
return UBI_IO_BITFLIPS;
}
if (ops.retlen != ops.len && err == -EBADMSG) {
ubi_err("err(%d), retlen(%zu), len(%zu)", err, ops.retlen, ops.len);
dump_stack();
err = -EIO;
}
ubi_msg("mtd_read_oob err %d\n", err);
}
return err;
}
/**
* ubi_debugfs_init - create UBI debugfs directory.
*
* Create UBI debugfs directory. Returns zero in case of success and a negative
* error code in case of failure.
*/
int ubi_debugfs_init(void)
{
if (!IS_ENABLED(CONFIG_DEBUG_FS))
return 0;
dfs_rootdir = debugfs_create_dir("ubi", NULL);
if (IS_ERR_OR_NULL(dfs_rootdir)) {
int err = dfs_rootdir ? -ENODEV : PTR_ERR(dfs_rootdir);
ubi_err(UBI_MAX_DEVICES, "cannot create \"ubi\" debugfs directory, error %d\n",
err);
return err;
}
return 0;
}
/**
* ubi_volume_notify - send a volume change notification.
* @ubi: UBI device description object
* @vol: volume description object of the changed volume
* @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
*
* This is a helper function which notifies all subscribers about a volume
* change event (creation, removal, re-sizing, re-naming, updating). Returns
* zero in case of success and a negative error code in case of failure.
*/
int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
{
#ifdef CONFIG_MTD_UBI_FASTMAP
switch (ntype) {
case UBI_VOLUME_ADDED:
case UBI_VOLUME_REMOVED:
case UBI_VOLUME_RESIZED:
case UBI_VOLUME_RENAMED:
if (ubi_update_fastmap(ubi)) {
ubi_err("Unable to update fastmap!");
ubi_ro_mode(ubi);
}
}
#endif
return 0;
}
/**
* ubi_add_volume - add volume.
* @ubi: UBI device description object
* @vol: volume description object
*
* This function adds an existing volume and initializes all its data
* structures. Returns zero in case of success and a negative error code in
* case of failure.
*/
int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol)
{
int err = 0;
dbg_gen("add volume");
/* Register character device for the volume */
err = ubi_volume_cdev_add(ubi, vol);
if (err) {
ubi_err("cannot add character device for volume, error %d",
err);
return err;
}
self_check_volumes(ubi);
return err;
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;
struct ubi_vid_hdr vid_hdr;
addr = (loff_t)pnum * ubi->peb_size + ubi->vid_hdr_aloffset;
err = ubi->mtd->write(ubi->mtd, addr, 4, &written, (void *)&data);
if (!err) {
addr -= ubi->vid_hdr_aloffset;
err = ubi->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 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_VID_HDR)
/*
* The VID header is 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_dbg_dump_flash(ubi, pnum, 0, ubi->peb_size);
return -EIO;
}
static ssize_t ubi_volume_cdev_read(struct cdev *cdev, void *buf, size_t size,
loff_t offset, unsigned long flags)
{
struct ubi_volume_cdev_priv *priv = cdev->priv;
struct ubi_volume *vol = priv->vol;
struct ubi_device *ubi = priv->ubi;
int err, lnum, off, len;
size_t count_save = size;
unsigned long long tmp;
loff_t offp = offset;
int usable_leb_size = vol->usable_leb_size;
ubi_debug("%s: %zd @ 0x%08llx", __func__, size, offset);
len = size > usable_leb_size ? usable_leb_size : size;
tmp = offp;
off = do_div(tmp, usable_leb_size);
lnum = tmp;
do {
if (off + len >= usable_leb_size)
len = usable_leb_size - off;
err = ubi_eba_read_leb(ubi, vol, lnum, buf, off, len, 0);
if (err) {
ubi_err(ubi, "read error: %s", strerror(-err));
break;
}
off += len;
if (off == usable_leb_size) {
lnum += 1;
off -= usable_leb_size;
}
size -= len;
offp += len;
buf += len;
len = size > usable_leb_size ? usable_leb_size : size;
} while (size);
return count_save;
}
/**
* ubi_dbg_check_write - make sure write succeeded.
* @ubi: UBI device description object
* @buf: buffer with data which were written
* @pnum: physical eraseblock number the data were written to
* @offset: offset within the physical eraseblock the data were written to
* @len: how many bytes were written
*
* This functions reads data which were recently written and compares it with
* the original data buffer - the data have to match. Returns zero if the data
* match and a negative error code if not or in case of failure.
*/
int ubi_dbg_check_write(struct ubi_device *ubi, const void *buf, int pnum,
int offset, int len)
{
int err, i;
mutex_lock(&ubi->dbg_buf_mutex);
err = ubi_io_read(ubi, ubi->dbg_peb_buf, pnum, offset, len);
if (err)
goto out_unlock;
for (i = 0; i < len; i++) {
uint8_t c = ((uint8_t *)buf)[i];
uint8_t c1 = ((uint8_t *)ubi->dbg_peb_buf)[i];
int dump_len;
if (c == c1)
continue;
ubi_err("paranoid check failed for PEB %d:%d, len %d",
pnum, offset, len);
ubi_msg("data differ at position %d", i);
dump_len = max_t(int, 128, len - i);
ubi_msg("hex dump of the original buffer from %d to %d",
i, i + dump_len);
print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
buf + i, dump_len, 1);
ubi_msg("hex dump of the read buffer from %d to %d",
i, i + dump_len);
print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
ubi->dbg_peb_buf + i, dump_len, 1);
ubi_dbg_dump_stack();
err = -EINVAL;
goto out_unlock;
}
mutex_unlock(&ubi->dbg_buf_mutex);
return 0;
out_unlock:
mutex_unlock(&ubi->dbg_buf_mutex);
return err;
}
/**
* 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(ubi, "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;
}
static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
size_t count, loff_t *offp)
{
int err = 0;
struct ubi_volume_desc *desc = file->private_data;
struct ubi_volume *vol = desc->vol;
struct ubi_device *ubi = vol->ubi;
if (!vol->updating)
return vol_cdev_direct_write(file, buf, count, offp);
err = ubi_more_update_data(ubi, vol->vol_id, buf, count);
if (err < 0) {
ubi_err("cannot write %zd bytes of update data", count);
return err;
}
if (err) {
/*
* Update is finished, @err contains number of actually written
* bytes now.
*/
count = err;
err = ubi_check_volume(ubi, vol->vol_id);
if (err < 0)
return err;
if (err) {
ubi_warn("volume %d on UBI device %d is corrupted",
vol->vol_id, ubi->ubi_num);
vol->corrupted = 1;
}
vol->checked = 1;
ubi_gluebi_updated(vol);
revoke_exclusive(desc, UBI_READWRITE);
}
*offp += count;
return count;
}
/**
* ubi_create_gluebi - initialize gluebi for an UBI volume.
* @ubi: UBI device description object
* @vol: volume description object
*
* This function is called when an UBI volume is created in order to create
* corresponding fake MTD device. Returns zero in case of success and a
* negative error code in case of failure.
*/
int ubi_create_gluebi(struct ubi_device *ubi, struct ubi_volume *vol)
{
struct mtd_info *mtd = &vol->gluebi_mtd;
mtd->name = kmemdup(vol->name, vol->name_len + 1, GFP_KERNEL);
if (!mtd->name)
return -ENOMEM;
mtd->type = MTD_UBIVOLUME;
if (!ubi->ro_mode)
mtd->flags = MTD_WRITEABLE;
mtd->writesize = ubi->min_io_size;
mtd->owner = THIS_MODULE;
mtd->erasesize = vol->usable_leb_size;
mtd->read = gluebi_read;
mtd->write = gluebi_write;
mtd->erase = gluebi_erase;
mtd->get_device = gluebi_get_device;
mtd->put_device = gluebi_put_device;
/*
* In case of dynamic volume, MTD device size is just volume size. In
* case of a static volume the size is equivalent to the amount of data
* bytes.
*/
if (vol->vol_type == UBI_DYNAMIC_VOLUME)
mtd->size = (long long)vol->usable_leb_size * vol->reserved_pebs;
else
mtd->size = vol->used_bytes;
if (add_mtd_device(mtd)) {
ubi_err("cannot not add MTD device");
kfree(mtd->name);
return -ENFILE;
}
dbg_gen("added mtd%d (\"%s\"), size %llu, EB size %u",
mtd->index, mtd->name, (unsigned long long)mtd->size, mtd->erasesize);
return 0;
}
/**
* do_work - do one pending work.
* @ubi: UBI device description object
*
* This function returns zero in case of success and a negative error code in
* case of failure.
*/
static int do_work(struct ubi_device *ubi)
{
int err;
struct ubi_work *wrk;
cond_resched();
/*
* @ubi->work_sem is used to synchronize with the workers. Workers take
* it in read mode, so many of them may be doing works at a time. But
* the queue flush code has to be sure the whole queue of works is
* done, and it takes the mutex in write mode.
*/
down_read(&ubi->work_sem);
spin_lock(&ubi->wl_lock);
if (list_empty(&ubi->works)) {
spin_unlock(&ubi->wl_lock);
up_read(&ubi->work_sem);
return 0;
}
wrk = list_entry(ubi->works.next, struct ubi_work, list);
list_del(&wrk->list);
ubi->works_count -= 1;
ubi_assert(ubi->works_count >= 0);
spin_unlock(&ubi->wl_lock);
/*
* Call the worker function. Do not touch the work structure
* after this call as it will have been freed or reused by that
* time by the worker function.
*/
err = wrk->func(ubi, wrk, 0);
if (err)
ubi_err(ubi, "work failed with error code %d", err);
up_read(&ubi->work_sem);
return err;
}
/**
* ubi_dbg_dump_flash - dump a region of flash.
* @ubi: UBI device description object
* @pnum: the physical eraseblock number to dump
* @offset: the starting offset within the physical eraseblock to dump
* @len: the length of the region to dump
*/
void ubi_dbg_dump_flash(struct ubi_device *ubi, int pnum, int offset, int len)
{
int err;
size_t read;
void *buf;
loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
buf = vmalloc(len);
if (!buf)
return;
err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf);
if (err && err != -EUCLEAN) {
ubi_err("error %d while reading %d bytes from PEB %d:%d, "
"read %zd bytes", err, len, pnum, offset, read);
goto out;
}
dbg_msg("dumping %d bytes of data from PEB %d, offset %d",
len, pnum, offset);
print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, buf, len, 1);
out:
vfree(buf);
return;
}
/**
* ubi_scan_add_used - add physical eraseblock to the scanning information.
* @ubi: UBI device description object
* @si: scanning 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_scan_add_used(struct ubi_device *ubi, struct ubi_scan_info *si,
int pnum, int ec, const struct ubi_vid_hdr *vid_hdr,
int bitflips)
{
int err, vol_id, lnum;
unsigned long long sqnum;
struct ubi_scan_volume *sv;
struct ubi_scan_leb *seb;
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);
sv = add_volume(si, vol_id, pnum, vid_hdr);
if (IS_ERR(sv))
return PTR_ERR(sv);
if (si->max_sqnum < sqnum)
si->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 = &sv->root.rb_node;
while (*p) {
int cmp_res;
parent = *p;
seb = rb_entry(parent, struct ubi_scan_leb, u.rb);
if (lnum != seb->lnum) {
if (lnum < seb->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", seb->pnum, seb->sqnum, seb->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
* '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 (seb->sqnum == sqnum && sqnum != 0) {
ubi_err("two LEBs with same sequence number %llu",
sqnum);
ubi_dbg_dump_seb(seb, 0);
ubi_dbg_dump_vid_hdr(vid_hdr);
return -EINVAL;
}
/*
* Now we have to drop the older one and preserve the newer
* one.
*/
cmp_res = compare_lebs(ubi, seb, 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, sv, pnum);
if (err)
return err;
err = add_to_list(si, seb->pnum, seb->ec, cmp_res & 4,
&si->erase);
if (err)
return err;
seb->ec = ec;
seb->pnum = pnum;
seb->scrub = ((cmp_res & 2) || bitflips);
seb->copy_flag = vid_hdr->copy_flag;
seb->sqnum = sqnum;
if (sv->highest_lnum == lnum)
sv->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(si, pnum, ec, cmp_res & 4,
&si->erase);
}
}
/*
* We've met this logical eraseblock for the first time, add it to the
* scanning information.
*/
err = validate_vid_hdr(vid_hdr, sv, pnum);
if (err)
return err;
seb = kmem_cache_alloc(si->scan_leb_slab, GFP_KERNEL);
if (!seb)
return -ENOMEM;
seb->ec = ec;
seb->pnum = pnum;
seb->lnum = lnum;
seb->scrub = bitflips;
seb->copy_flag = vid_hdr->copy_flag;
seb->sqnum = sqnum;
if (sv->highest_lnum <= lnum) {
sv->highest_lnum = lnum;
sv->last_data_size = be32_to_cpu(vid_hdr->data_size);
}
sv->leb_count += 1;
rb_link_node(&seb->u.rb, parent, p);
rb_insert_color(&seb->u.rb, &sv->root);
return 0;
}
/**
* 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 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.
*/
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 (sqnum2 == seb->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("unsupported on-flash UBI format\n");
return -EINVAL;
}
/* 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.
*
* 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 (!seb->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 = seb->pnum;
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, 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);
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 && !mtd_is_eccerr(err))
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;
}
