/*
* ubi_leb_change - change logical eraseblock atomically.
* @desc: volume descriptor
* @lnum: logical eraseblock number to change
* @buf: data to write
* @len: how many bytes to write
* @dtype: expected data type
*
* This function changes the contents of a logical eraseblock atomically. @buf
* has to contain new logical eraseblock data, and @len - the length of the
* data, which has to be aligned. The length may be shorter than the logical
* eraseblock size, ant the logical eraseblock may be appended to more times
* later on. This function guarantees that in case of an unclean reboot the old
* contents is preserved. Returns zero in case of success and a negative error
* code in case of failure.
*/
int ubi_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
int len, int dtype)
{
struct ubi_volume *vol = desc->vol;
struct ubi_device *ubi = vol->ubi;
int vol_id = vol->vol_id;
dbg_gen("atomically write %d bytes to LEB %d:%d", len, vol_id, lnum);
if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
return -EINVAL;
if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
return -EROFS;
if (lnum < 0 || lnum >= vol->reserved_pebs || len < 0 ||
len > vol->usable_leb_size || len & (ubi->min_io_size - 1))
return -EINVAL;
if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
dtype != UBI_UNKNOWN)
return -EINVAL;
if (vol->upd_marker)
return -EBADF;
if (len == 0)
return 0;
return ubi_eba_atomic_leb_change(ubi, vol, lnum, buf, len, dtype);
}
/**
* ubi_update_layout_vol - helper for updatting layout volumes on flash
* @ubi: UBI device description object
*/
static int ubi_update_layout_vol(struct ubi_device *ubi)
{
struct ubi_volume *layout_vol;
int i, err;
layout_vol = ubi->volumes[vol_id2idx(ubi, UBI_LAYOUT_VOLUME_ID)];
for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) {
err = ubi_eba_atomic_leb_change(ubi, layout_vol, i, ubi->vtbl,
ubi->vtbl_size);
if (err)
return err;
}
return 0;
}
/**
* ubi_more_leb_change_data - accept more data for atomic LEB change.
* @ubi: UBI device description object
* @vol: volume description object
* @buf: write data (user-space memory buffer)
* @count: how much bytes to write
*
* This function accepts more data to the volume which is being under the
* "atomic LEB change" operation. It may be called arbitrary number of times
* until all data arrives. This function returns %0 in case of success, number
* of bytes written during the last call if the whole "atomic LEB change"
* operation has been successfully finished, and a negative error code in case
* of failure.
*/
int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
const void __user *buf, int count)
{
int err;
dbg_gen("write %d of %lld bytes, %lld already passed",
count, vol->upd_bytes, vol->upd_received);
if (ubi->ro_mode)
return -EROFS;
if (vol->upd_received + count > vol->upd_bytes)
count = vol->upd_bytes - vol->upd_received;
err = copy_from_user(vol->upd_buf + vol->upd_received, buf, count);
if (err)
return -EFAULT;
vol->upd_received += count;
if (vol->upd_received == vol->upd_bytes) {
int len = ALIGN((int)vol->upd_bytes, ubi->min_io_size);
memset(vol->upd_buf + vol->upd_bytes, 0xFF,
len - vol->upd_bytes);
len = ubi_calc_data_len(ubi, vol->upd_buf, len);
err = ubi_eba_atomic_leb_change(ubi, vol, vol->ch_lnum,
vol->upd_buf, len);
if (err)
return err;
}
ubi_assert(vol->upd_received <= vol->upd_bytes);
if (vol->upd_received == vol->upd_bytes) {
vol->changing_leb = 0;
err = count;
vfree(vol->upd_buf);
}
return err;
}
/**
* ubi_start_leb_change - start atomic LEB change.
* @ubi: UBI device description object
* @vol: volume description object
* @req: operation request
*
* This function starts atomic LEB change operation. Returns zero in case of
* success and a negative error code in case of failure.
*/
int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
const struct ubi_leb_change_req *req)
{
ubi_assert(!vol->updating && !vol->changing_leb);
dbg_gen("start changing LEB %d:%d, %u bytes",
vol->vol_id, req->lnum, req->bytes);
if (req->bytes == 0)
return ubi_eba_atomic_leb_change(ubi, vol, req->lnum, NULL, 0);
vol->upd_bytes = req->bytes;
vol->upd_received = 0;
vol->changing_leb = 1;
vol->ch_lnum = req->lnum;
vol->upd_buf = vmalloc(req->bytes);
if (!vol->upd_buf)
return -ENOMEM;
return 0;
}
