[PATCH 8/8] NFS: Enable NFSv4 callback server to listen on AF_INET6 sockets

[Chuck Lever <chuck.lever@oracle.com>]

Allow the NFS callback server to listen for requests via an AF_INET6 or
AF_INET socket.

The NFS callback server determines the listener's address family from the
address the client uses to contact the server.  The server will always
call the client back using the same address family.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---

 fs/nfs/callback.c |   11 ++++++-----
 fs/nfs/callback.h |    4 ++--
 fs/nfs/client.c   |    2 +-
 3 files changed, 9 insertions(+), 8 deletions(-)


diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index 6a09760..59948ef 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -97,7 +97,7 @@ nfs_callback_svc(void *vrqstp)
 /*
  * Bring up the callback thread if it is not already up.
  */
-int nfs_callback_up(void)
+int nfs_callback_up(const sa_family_t family)
 {
 	struct svc_serv *serv = NULL;
 	int ret = 0;
@@ -106,7 +106,7 @@ int nfs_callback_up(void)
 	if (nfs_callback_info.users++ || nfs_callback_info.task != NULL)
 		goto out;
 	serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE,
-				AF_INET, NULL);
+				family, NULL);
 	ret = -ENOMEM;
 	if (!serv)
 		goto out_err;
@@ -116,7 +116,8 @@ int nfs_callback_up(void)
 	if (ret <= 0)
 		goto out_err;
 	nfs_callback_tcpport = ret;
-	dprintk("Callback port = 0x%x\n", nfs_callback_tcpport);
+	dprintk("NFS: Callback listener port = %u (af %u)\n",
+			nfs_callback_tcpport, family);
 
 	nfs_callback_info.rqst = svc_prepare_thread(serv, &serv->sv_pools[0]);
 	if (IS_ERR(nfs_callback_info.rqst)) {
@@ -149,8 +150,8 @@ out:
 	mutex_unlock(&nfs_callback_mutex);
 	return ret;
 out_err:
-	dprintk("Couldn't create callback socket or server thread; err = %d\n",
-		ret);
+	dprintk("NFS: Couldn't create callback socket or server thread; "
+		"err = %d\n", ret);
 	nfs_callback_info.users--;
 	goto out;
 }
diff --git a/fs/nfs/callback.h b/fs/nfs/callback.h
index bb25d21..85d8102 100644
--- a/fs/nfs/callback.h
+++ b/fs/nfs/callback.h
@@ -63,10 +63,10 @@ extern __be32 nfs4_callback_getattr(struct cb_getattrargs *args, struct cb_getat
 extern __be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy);
 
 #ifdef CONFIG_NFS_V4
-extern int nfs_callback_up(void);
+extern int nfs_callback_up(const sa_family_t family);
 extern void nfs_callback_down(void);
 #else
-#define nfs_callback_up()	(0)
+#define nfs_callback_up(x)	(0)
 #define nfs_callback_down()	do {} while(0)
 #endif
 
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index f2a092c..f1bb2af 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -120,7 +120,7 @@ static struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_
 	clp->rpc_ops = cl_init->rpc_ops;
 
 	if (cl_init->rpc_ops->version == 4) {
-		if (nfs_callback_up() < 0)
+		if (nfs_callback_up(cl_init->addr->sa_family) < 0)
 			goto error_2;
 		__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
 	}