diff -bpru oldu/mount/nfs_mount4.h newu/mount/nfs_mount4.h
--- oldu/mount/nfs_mount4.h	Sat Oct 14 09:20:51 2000
+++ newu/mount/nfs_mount4.h	Fri Jul 26 11:27:21 2002
@@ -8,7 +8,7 @@
  * so it is easiest to ignore the kernel altogether (at compile time).
  */
 
-#define NFS_MOUNT_VERSION	4
+#define NFS_MOUNT_VERSION	5
 
 struct nfs2_fh {
         char                    data[32];
@@ -36,6 +36,8 @@ struct nfs_mount_data {
 	int		namlen;			/* 2 */
 	unsigned int	bsize;			/* 3 */
 	struct nfs3_fh	root;			/* 4 */
+	char            mnt_path[256];		/* 5 */
+	char            ip_addr[16];		/* 5 */
 };
 
 /* bits in the flags field */
@@ -51,4 +53,5 @@ struct nfs_mount_data {
 #define NFS_MOUNT_KERBEROS	0x0100	/* 3 */
 #define NFS_MOUNT_NONLM		0x0200	/* 3 */
 #define NFS_MOUNT_BROKEN_SUID	0x0400	/* 4 */
+#define NFS_MOUNT_VER4		0x0800  /* 5 */
 
diff -bpru oldu/mount/nfsmount.c newu/mount/nfsmount.c
--- oldu/mount/nfsmount.c	Fri Apr  5 05:35:53 2002
+++ newu/mount/nfsmount.c	Fri Jul 26 11:53:07 2002
@@ -72,11 +72,14 @@
 #define NFS_FHSIZE 32
 #endif
 
+#define GSSPROG 100666
+
 static char *nfs_strerror(int stat);
 
 #define MAKE_VERSION(p,q,r)	(65536*(p) + 256*(q) + (r))
 
-#define MAX_NFSPROT ((nfs_mount_version >= 4) ? 3 : 2)
+#define MAX_NFSPROT ((nfs_mount_version >= 5) ? 4 : \
+                    ((nfs_mount_version >= 4) ? 3 : 2))
 
 static int
 linux_version_code(void) {
@@ -119,8 +122,10 @@ find_kernel_nfs_mount_version(void) {
 		  nfs_mount_version = 4; /* since 2.2.18pre9 */
 	     else if (kernel_version < MAKE_VERSION(2,3,99))
 		  nfs_mount_version = 3;
-	     else
+	     else if (kernel_version < MAKE_VERSION(2,5,25))
 		  nfs_mount_version = 4; /* since 2.3.99pre4 */
+	     else
+		  nfs_mount_version = 5;
 	}
 	if (nfs_mount_version > NFS_MOUNT_VERSION)
 	     nfs_mount_version = NFS_MOUNT_VERSION;
@@ -188,6 +193,23 @@ get_mountport(struct sockaddr_in *server
 	return &p;
 }
 
+static int
+check_for_gssd(void)
+{
+	struct pmaplist *pmap;
+	struct sockaddr_in local_addr;
+
+	memset(&local_addr, 0, sizeof(local_addr));
+	local_addr.sin_family = AF_INET;
+	local_addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+	local_addr.sin_port = htons(PMAPPORT);
+
+	for (pmap = pmap_getmaps(&local_addr); pmap; pmap = pmap->pml_next)
+		if (pmap->pml_map.pm_prog == GSSPROG)
+			return 0;
+	return -1;
+}
+
 int nfsmount(const char *spec, const char *node, int *flags,
 	     char **extra_opts, char **mount_opts, int *nfs_mount_vers,
 	     int running_bg)
@@ -223,6 +245,10 @@ int nfsmount(const char *spec, const cha
 	time_t t;
 	time_t prevt;
 	time_t timeout;
+	char lname[128];
+	struct hostent *lh;
+	struct in_addr lin;
+	char *laddr;
 
 	/* The version to try is either specified or 0
 	   In case it is 0 we tell the caller what we tried */
@@ -511,6 +537,9 @@ int nfsmount(const char *spec, const cha
 		return retval;
 	}
 
+	if (nfsvers == 4)
+		goto skip_mountd;
+
 	/* create mount deamon client */
 	/* See if the nfs host = mount host. */
 	if (mounthost) {
@@ -670,6 +699,7 @@ int nfsmount(const char *spec, const cha
 	}
 	nfsvers = (pm_mnt->pm_vers < 2) ? 2 : pm_mnt->pm_vers;
 
+skip_mountd:
 	if (nfsvers == 2) {
 		if (status.nfsv2.fhs_status != 0) {
 			fprintf(stderr,
@@ -687,7 +717,7 @@ int nfsmount(const char *spec, const cha
 		       (char *) status.nfsv2.fhstatus_u.fhs_fhandle,
 		       NFS_FHSIZE);
 #endif
-	} else {
+	} else if (nfsvers == 3) {
 #if NFS_MOUNT_VERSION >= 4
 		fhandle3 *fhandle;
 		if (status.nfsv3.fhs_status != 0) {
@@ -707,6 +737,37 @@ int nfsmount(const char *spec, const cha
 
 		data.flags |= NFS_MOUNT_VER3;
 #endif
+	} else {
+		retval = EX_FAIL;
+		if (check_for_gssd()) {
+			fprintf(stderr, _("mount: local GSSD service not available\n"));
+			goto fail;
+		}
+		if (strlen(dirname) >= sizeof(data.mnt_path)) {
+			fprintf(stderr, _("mount: remote pathname too long\n"));
+			goto fail;
+		}
+
+		/*
+		 * Determine the local IP address, as a string in dotted-quad
+		 * format.  This is used by the client kernel to provide a
+		 * callback path to the server, and to set the NFSv4 clientid.
+		 */
+		strncpy(data.mnt_path, dirname, sizeof(data.mnt_path));
+		if (gethostname(lname, sizeof(lname)) < 0) {
+			perror(_("gethostname"));
+			goto fail;
+		}
+		lh = gethostbyname(lname);
+		if (!lh) {
+			fprintf(stderr, _("mount: couldn't determine local hostname\n"));
+			goto fail;
+		}
+		memcpy(&lin.s_addr, lh->h_addr, sizeof(lin.s_addr));
+		laddr = inet_ntoa(lin);
+		strncpy(data.ip_addr, laddr, sizeof(data.ip_addr));
+		
+		data.flags |= NFS_MOUNT_VER4;
 	}
 
 	/* create nfs socket for kernel */
@@ -774,8 +835,11 @@ int nfsmount(const char *spec, const cha
 
 	/* clean up */
 
+	if (mclient) {
 	auth_destroy(mclient->cl_auth);
 	clnt_destroy(mclient);
+	}
+	if (msock != -1)
 	close(msock);
 	return 0;
 
diff -bpru oldu/mount/umount.c newu/mount/umount.c
--- oldu/mount/umount.c	Thu Mar 28 16:39:56 2002
+++ newu/mount/umount.c	Fri Jul 26 12:09:10 2002
@@ -263,7 +263,7 @@ umount_one (const char *spec, const char
 #ifdef HAVE_NFS
 	/* Ignore any RPC errors, so that you can umount the filesystem
 	   if the server is down.  */
-	if (strcasecmp(type, "nfs") == 0)
+	if (strcasecmp(type, "nfs") == 0 && strstr(opts, "vers=4") == NULL)
 		nfs_umount_rpc_call(spec, opts);
 #endif