This is xnu-6153.11.26. See this file in:
Directory listing for xnu-6153.11.26//bsd/nfs
Makefile
gss/
krpc.h
krpc_subr.c
nfs.h
nfs4_subs.c
nfs4_vnops.c
nfs_bio.c
nfs_boot.c
nfs_gss.c
nfs_gss.h
nfs_ioctl.h
nfs_lock.c
nfs_lock.h
nfs_node.c
nfs_serv.c
nfs_socket.c
nfs_srvcache.c
nfs_subs.c
nfs_syscalls.c
nfs_upcall.c
nfs_vfsops.c
nfs_vnops.c
nfsdiskless.h
nfsm_subs.h
nfsmount.h
nfsnode.h
nfsproto.h
nfsrvcache.h
rpcv2.h
xdr_subs.h