Inherit the optimal I/O size setting just like the readahead window,
as any reason to do larger I/O does not apply to just readahead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
        dc->disk.disk->queue->backing_dev_info->ra_pages =
                max(dc->disk.disk->queue->backing_dev_info->ra_pages,
                    q->backing_dev_info->ra_pages);
+       blk_queue_io_opt(dc->disk.disk->queue,
+               max(queue_io_opt(dc->disk.disk->queue), queue_io_opt(q)));
 
        atomic_set(&dc->io_errors, 0);
        dc->io_disable = false;