fsess_opt_datacache
!fsess_opt_datacache(vnode_mount(vp)) ||
return (fsess_opt_datacache(mp));
directio = (ioflag & IO_DIRECT) || !fsess_opt_datacache(vnode_mount(vp));
directio = (ioflag & IO_DIRECT) || !fsess_opt_datacache(vnode_mount(vp));