CTL_MS_SECTOR_BUFFER_t *ctl_ms_write_lock_sector(CTL_MS_VOLUME_t *vol, CTL_MS_LBA_t sector);
ctl_ms_write_lock_sector reads sector sector from volume vol into the sector cache if not already present. Sectors will be flushed to the media as necessary in order to make space in the cache for the requested sector. The sector buffer associated with the sector will be marked dirty so that it will be flushed by ctl_ms_flush_sector_cache or when space is needed in the sector cache. ctl_ms_write_lock_sector will return zero if there is an error reading the sector from the volume.