LCN vcn_to_lcn (const run_list_element * rl, const VCN vcn);
Convert the virtual cluster number vcn of an attribute into a logical cluster number (lcn) of a device using the run list rl to map vcns to their corresponding lcns.
It is up to the caller to serialize access to the run list rl.
Since lcns must be >= 0, we use negative return values with special meaning:
Return value Meaning / Description ================================================== -1 = LCN_HOLE Hole / not allocated on disk. -2 = LCN_RL_NOT_MAPPED This is part of the run list which has not been inserted into the run list yet. -3 = LCN_ENOENT There is no such vcn in the attribute. -4 = LCN_EINVAL Input parameter error (if debug enabled).