diff -p -u -r -N linux-2.6.23-ipmap-cache/fs/nfsd/nfsctl.c linux-2.6.23-nfsctl/fs/nfsd/nfsctl.c
--- linux-2.6.23-ipmap-cache/fs/nfsd/nfsctl.c	2007-10-11 15:23:07.000000000 +0200
+++ linux-2.6.23-nfsctl/fs/nfsd/nfsctl.c	2007-10-12 10:49:31.000000000 +0200
@@ -219,7 +219,7 @@ static ssize_t write_unexport(struct fil
 static ssize_t write_getfs(struct file *file, char *buf, size_t size)
 {
 	struct nfsctl_fsparm *data;
-	struct sockaddr_in *sin;
+	struct sockaddr_in6 *sin, sin6_storage;
 	struct auth_domain *clp;
 	int err = 0;
 	struct knfsd_fh *res;
@@ -228,9 +228,20 @@ static ssize_t write_getfs(struct file *
 		return -EINVAL;
 	data = (struct nfsctl_fsparm*)buf;
 	err = -EPROTONOSUPPORT;
-	if (data->gd_addr.sa_family != AF_INET)
+	sin = &sin6_storage;
+	switch (data->gd_addr.sa_family) {
+	case AF_INET6:
+		sin = (struct sockaddr_in6 *)&data->gd_addr;
+		in6 = sin->sin6_addr;
+		break;
+	case AF_INET:
+		/* Map v4 address into v6 structure */
+		ipv6_addr_v4map(((struct sockaddr_in *)&data->gd_addr)->sin_addr, in6);
+		break;
+	default:
 		goto out;
-	sin = (struct sockaddr_in *)&data->gd_addr;
+	}
+
 	if (data->gd_maxlen > NFS3_FHSIZE)
 		data->gd_maxlen = NFS3_FHSIZE;
 
@@ -238,9 +249,6 @@ static ssize_t write_getfs(struct file *
 
 	exp_readlock();
 
-	/* IPv6 address mapping */
-	ipv6_addr_v4map(sin->sin_addr, in6);
-
 	if (!(clp = auth_unix_lookup(in6)))
 		err = -EPERM;
 	else {
@@ -257,7 +265,7 @@ static ssize_t write_getfs(struct file *
 static ssize_t write_getfd(struct file *file, char *buf, size_t size)
 {
 	struct nfsctl_fdparm *data;
-	struct sockaddr_in *sin;
+	struct sockaddr_in6 *sin, sin6_storage;
 	struct in6_addr in6;
 	struct auth_domain *clp;
 	int err = 0;
@@ -268,18 +276,29 @@ static ssize_t write_getfd(struct file *
 		return -EINVAL;
 	data = (struct nfsctl_fdparm*)buf;
 	err = -EPROTONOSUPPORT;
-	if (data->gd_addr.sa_family != AF_INET)
+	if (data->gd_addr.sa_family != AF_INET && 
+		data->gd_addr.sa_family != AF_INET6)
 		goto out;
 	err = -EINVAL;
 	if (data->gd_version < 2 || data->gd_version > NFSSVC_MAXVERS)
 		goto out;
 
 	res = buf;
-	sin = (struct sockaddr_in *)&data->gd_addr;
+	sin = &sin6_storage;
 	exp_readlock();
 
-	/* IPv6 address mapping */
-	ipv6_addr_v4map(sin->sin_addr, in6);
+	switch (data->gd_addr.sa_family) {
+	case AF_INET:
+		/* IPv6 address mapping */
+		ipv6_addr_v4map(((struct sockaddr_in *)&data->gd_addr)->sin_addr, in6);
+		break;
+	case AF_INET6:
+		sin = (struct sockaddr_in6 *)&data->gd_addr;
+		in6 = sin->sin6_addr;
+		break;
+	default:
+		BUG();
+	}
 
 	if (!(clp = auth_unix_lookup(in6)))
 		err = -EPERM;