IOC_SECT_TO_PAGE_SHIFT
u64 pages = max_t(u64, bio_sectors(bio) >> IOC_SECT_TO_PAGE_SHIFT, 1);
seek_pages >>= IOC_SECT_TO_PAGE_SHIFT;
unsigned int pages = blk_rq_stats_sectors(rq) >> IOC_SECT_TO_PAGE_SHIFT;