nfs4_ff_layoutstat
struct nfs4_ff_layoutstat *layoutstat,
nfs4_ff_layout_stat_io_update_requested(struct nfs4_ff_layoutstat *layoutstat,
nfs4_ff_layout_stat_io_update_completed(struct nfs4_ff_layoutstat *layoutstat,
struct nfs4_ff_layoutstat read_stat;
struct nfs4_ff_layoutstat write_stat;