The 32-bit field, dma_len, packs better in the iod struct above the
dma_addr_t on 64-bit systems.
Reviewed-by: NChaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>