Merge git://git.linux-nfs.org/projects/trondmy/nfs-2.6

* git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
  NFS: use correct fs type for v4 submounts and referrals
  Make nfs_file_cred more robust.
  NFS: Enable NFSv4 callback server to listen on AF_INET6 sockets

fs/nfs/callback.c

@@ -40,6 +40,16 @@ unsigned short nfs_callback_tcpport;
 static const int nfs_set_port_min = 0;
 static const int nfs_set_port_max = 65535;
 
+/*
+ * If the kernel has IPv6 support available, always listen for
+ * both AF_INET and AF_INET6 requests.
+ */
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+static const sa_family_t	nfs_callback_family = AF_INET6;
+#else
+static const sa_family_t	nfs_callback_family = AF_INET;
+#endif
+
 static int param_set_port(const char *val, struct kernel_param *kp)
 {
 	char *endp;
@@ -106,7 +116,7 @@ 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);
+				nfs_callback_family, NULL);
 	ret = -ENOMEM;
 	if (!serv)
 		goto out_err;
@@ -116,7 +126,8 @@ 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, nfs_callback_family);
 
 	nfs_callback_info.rqst = svc_prepare_thread(serv, &serv->sv_pools[0]);
 	if (IS_ERR(nfs_callback_info.rqst)) {
@@ -149,8 +160,8 @@ int nfs_callback_up(void)
 	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;
 }

fs/nfs/nfs4proc.c

@@ -1659,9 +1659,11 @@ nfs4_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr,
 		struct nfs_open_context *ctx;
 
 		ctx = nfs_file_open_context(sattr->ia_file);
+		if (ctx) {
 			cred = ctx->cred;
 			state = ctx->state;
 		}
+	}
 
 	status = nfs4_do_setattr(inode, cred, fattr, sattr, state);
 	if (status == 0)

fs/nfs/super.c

@@ -2459,7 +2459,7 @@ static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
 		compare_super = NULL;
 
 	/* Get a superblock - note that we may end up sharing one that already exists */
-	s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
+	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
 	if (IS_ERR(s)) {
 		error = PTR_ERR(s);
 		goto out_err_nosb;
@@ -2544,7 +2544,7 @@ static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
 		compare_super = NULL;
 
 	/* Get a superblock - note that we may end up sharing one that already exists */
-	s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
+	s = sget(&nfs4_fs_type, compare_super, nfs_set_super, &sb_mntdata);
 	if (IS_ERR(s)) {
 		error = PTR_ERR(s);
 		goto out_err_nosb;

include/linux/nfs_fs.h

@@ -367,8 +367,12 @@ static inline struct nfs_open_context *nfs_file_open_context(struct file *filp)
 
 static inline struct rpc_cred *nfs_file_cred(struct file *file)
 {
-	if (file != NULL)
-		return nfs_file_open_context(file)->cred;
+	if (file != NULL) {
+		struct nfs_open_context *ctx =
+			nfs_file_open_context(file);
+		if (ctx)
+			return ctx->cred;
+	}
 	return NULL;
 }