CTL_STATUS_t ctl_ms_unlock_buffer(CTL_MS_SECTOR_BUFFER_t *buf);

ctl_ms_unlock_buffer releases the sector buffer buf so that it can be flushed from the cache. Note that the buffer, if marked as dirty, is not immediately flushed to the media: you must call ctl_ms_flush_sector_cache in order to ensure that the contents of the media and the match the sector cache.