Btrfs: write_cache_pages came in 2.6.22

	return 0;

}

#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)

#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)

/* Taken directly from 2.6.23 for 2.6.18 back port */

typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc,

                                void *data);