#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,23)
        bdi_init(bdi);
 #endif
-       bdi->ra_pages   = default_backing_dev_info.ra_pages * 4;
+       bdi->ra_pages   = default_backing_dev_info.ra_pages;
        bdi->state              = 0;
        bdi->capabilities       = default_backing_dev_info.capabilities;
        bdi->unplug_io_fn       = btrfs_unplug_io_fn;
                       (unsigned long long)fs_devices->num_devices);
                goto fail_sb_buffer;
        }
+       fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
+
        nodesize = btrfs_super_nodesize(disk_super);
        leafsize = btrfs_super_leafsize(disk_super);
        sectorsize = btrfs_super_sectorsize(disk_super);