Merge branch 'master' into for-next

Pull linus#master to merge PER_CPU_DEF_ATTRIBUTES and alpha build fix
changes.  As alpha in percpu tree uses 'weak' attribute instead of
inline assembly, there's no need for __used attribute.

Conflicts:
	arch/alpha/include/asm/percpu.h
	arch/mn10300/kernel/vmlinux.lds.S
	include/linux/percpu-defs.h

1 files changed, 358 insertions, 139 deletions

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 26127b69a27..0b4cbdc60ab 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -42,6 +42,8 @@
 #include <linux/smp_lock.h>
 #include <linux/seq_file.h>
 #include <linux/mount.h>
+#include <linux/mnt_namespace.h>
+#include <linux/namei.h>
 #include <linux/nfs_idmap.h>
 #include <linux/vfs.h>
 #include <linux/inet.h>
@@ -90,6 +92,7 @@ enum {
 	Opt_mountport,
 	Opt_mountvers,
 	Opt_nfsvers,
+	Opt_minorversion,
 
 	/* Mount options that take string arguments */
 	Opt_sec, Opt_proto, Opt_mountproto, Opt_mounthost,
@@ -139,22 +142,23 @@ static const match_table_t nfs_mount_option_tokens = {
 	{ Opt_fscache_uniq, "fsc=%s" },
 	{ Opt_nofscache, "nofsc" },
 
-	{ Opt_port, "port=%u" },
-	{ Opt_rsize, "rsize=%u" },
-	{ Opt_wsize, "wsize=%u" },
-	{ Opt_bsize, "bsize=%u" },
-	{ Opt_timeo, "timeo=%u" },
-	{ Opt_retrans, "retrans=%u" },
-	{ Opt_acregmin, "acregmin=%u" },
-	{ Opt_acregmax, "acregmax=%u" },
-	{ Opt_acdirmin, "acdirmin=%u" },
-	{ Opt_acdirmax, "acdirmax=%u" },
-	{ Opt_actimeo, "actimeo=%u" },
-	{ Opt_namelen, "namlen=%u" },
-	{ Opt_mountport, "mountport=%u" },
-	{ Opt_mountvers, "mountvers=%u" },
-	{ Opt_nfsvers, "nfsvers=%u" },
-	{ Opt_nfsvers, "vers=%u" },
+	{ Opt_port, "port=%s" },
+	{ Opt_rsize, "rsize=%s" },
+	{ Opt_wsize, "wsize=%s" },
+	{ Opt_bsize, "bsize=%s" },
+	{ Opt_timeo, "timeo=%s" },
+	{ Opt_retrans, "retrans=%s" },
+	{ Opt_acregmin, "acregmin=%s" },
+	{ Opt_acregmax, "acregmax=%s" },
+	{ Opt_acdirmin, "acdirmin=%s" },
+	{ Opt_acdirmax, "acdirmax=%s" },
+	{ Opt_actimeo, "actimeo=%s" },
+	{ Opt_namelen, "namlen=%s" },
+	{ Opt_mountport, "mountport=%s" },
+	{ Opt_mountvers, "mountvers=%s" },
+	{ Opt_nfsvers, "nfsvers=%s" },
+	{ Opt_nfsvers, "vers=%s" },
+	{ Opt_minorversion, "minorversion=%u" },
 
 	{ Opt_sec, "sec=%s" },
 	{ Opt_proto, "proto=%s" },
@@ -270,10 +274,14 @@ static const struct super_operations nfs_sops = {
 #ifdef CONFIG_NFS_V4
 static int nfs4_get_sb(struct file_system_type *fs_type,
 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
+static int nfs4_remote_get_sb(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 static int nfs4_xdev_get_sb(struct file_system_type *fs_type,
 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 static int nfs4_referral_get_sb(struct file_system_type *fs_type,
 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
+static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt);
 static void nfs4_kill_super(struct super_block *sb);
 
 static struct file_system_type nfs4_fs_type = {
@@ -284,6 +292,14 @@ static struct file_system_type nfs4_fs_type = {
 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 };
 
+static struct file_system_type nfs4_remote_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "nfs4",
+	.get_sb		= nfs4_remote_get_sb,
+	.kill_sb	= nfs4_kill_super,
+	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
+};
+
 struct file_system_type nfs4_xdev_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "nfs4",
@@ -292,6 +308,14 @@ struct file_system_type nfs4_xdev_fs_type = {
 	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
 };
 
+static struct file_system_type nfs4_remote_referral_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "nfs4",
+	.get_sb		= nfs4_remote_referral_get_sb,
+	.kill_sb	= nfs4_kill_super,
+	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
+};
+
 struct file_system_type nfs4_referral_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "nfs4",
@@ -514,7 +538,6 @@ static void nfs_show_mount_options(struct seq_file *m, struct nfs_server *nfss,
 		const char *nostr;
 	} nfs_info[] = {
 		{ NFS_MOUNT_SOFT, ",soft", ",hard" },
-		{ NFS_MOUNT_INTR, ",intr", ",nointr" },
 		{ NFS_MOUNT_POSIX, ",posix", "" },
 		{ NFS_MOUNT_NOCTO, ",nocto", "" },
 		{ NFS_MOUNT_NOAC, ",noac", "" },
@@ -943,11 +966,6 @@ static int nfs_parse_security_flavors(char *value,
 	return 1;
 }
 
-static void nfs_parse_invalid_value(const char *option)
-{
-	dfprintk(MOUNT, "NFS:   bad value specified for %s option\n", option);
-}
-
 /*
  * Error-check and convert a string of mount options from user space into
  * a data structure.  The whole mount string is processed; bad options are
@@ -958,7 +976,7 @@ static int nfs_parse_mount_options(char *raw,
 				   struct nfs_parsed_mount_data *mnt)
 {
 	char *p, *string, *secdata;
-	int rc, sloppy = 0, errors = 0;
+	int rc, sloppy = 0, invalid_option = 0;
 
 	if (!raw) {
 		dfprintk(MOUNT, "NFS: mount options string was NULL.\n");
@@ -982,7 +1000,9 @@ static int nfs_parse_mount_options(char *raw,
 
 	while ((p = strsep(&raw, ",")) != NULL) {
 		substring_t args[MAX_OPT_ARGS];
-		int option, token;
+		unsigned long option;
+		int int_option;
+		int token;
 
 		if (!*p)
 			continue;
@@ -1091,114 +1111,156 @@ static int nfs_parse_mount_options(char *raw,
 		 * options that take numeric values
 		 */
 		case Opt_port:
-			if (match_int(args, &option) ||
-			    option < 0 || option > USHORT_MAX) {
-				errors++;
-				nfs_parse_invalid_value("port");
-			} else
-				mnt->nfs_server.port = option;
+			string = match_strdup(args);
+			if (string == NULL)
+				goto out_nomem;
+			rc = strict_strtoul(string, 10, &option);
+			kfree(string);
+			if (rc != 0 || option > USHORT_MAX)
+				goto out_invalid_value;
+			mnt->nfs_server.port = option;
 			break;
 		case Opt_rsize:
-			if (match_int(args, &option) || option < 0) {
-				errors++;
-				nfs_parse_invalid_value("rsize");
-			} else
-				mnt->rsize = option;
+			string = match_strdup(args);
+			if (string == NULL)
+				goto out_nomem;
+			rc = strict_strtoul(string, 10, &option);
+			kfree(string);
+			if (rc != 0)
+				goto out_invalid_value;
+			mnt->rsize = option;
 			break;
 		case Opt_wsize:
-			if (match_int(args, &option) || option < 0) {
-				errors++;
-				nfs_parse_invalid_value("wsize");
-			} else
-				mnt->wsize = option;
+			string = match_strdup(args);
+			if (string == NULL)
+				goto out_nomem;
+			rc = strict_strtoul(string, 10, &option);
+			kfree(string);
+			if (rc != 0)
+				goto out_invalid_value;
+			mnt->wsize = option;
 			break;
 		case Opt_bsize:
-			if (match_int(args, &option) || option < 0) {
-				errors++;
-				nfs_parse_invalid_value("bsize");
-			} else
-				mnt->bsize = option;
+			string = match_strdup(args);
+			if (string == NULL)
+				goto out_nomem;
+			rc = strict_strtoul(string, 10, &option);
+			kfree(string);
+			if (rc != 0)
+				goto out_invalid_value;
+			mnt->bsize = option;
 			break;
 		case Opt_timeo:
-			if (match_int(args, &option) || option <= 0) {
-				errors++;
-				nfs_parse_invalid_value("timeo");
-			} else
-				mnt->timeo = option;
+			string = match_strdup(args);
+			if (string == NULL)
+				goto out_nomem;
+			rc = strict_strtoul(string, 10, &option);
+			kfree(string);
+			if (rc != 0 || option == 0)
+				goto out_invalid_value;
+			mnt->timeo = option;
 			break;
 		case Opt_retrans:
-			if (match_int(args, &option) || option <= 0) {
-				errors++;
-				nfs_parse_invalid_value("retrans");
-			} else
-				mnt->retrans = option;
+			string = match_strdup(args);
+			if (string == NULL)
+				goto out_nomem;
+			rc = strict_strtoul(string, 10, &option);
+			kfree(string);
+			if (rc != 0 || option == 0)
+				goto out_invalid_value;
+			mnt->retrans = option;
 			break;
 		case Opt_acregmin:
-			if (match_int(args, &option) || option < 0) {
-				errors++;
-				nfs_parse_invalid_value("acregmin");
-			} else
-				mnt->acregmin = option;
+			string = match_strdup(args);
+			if (string == NULL)
+				goto out_nomem;
+			rc = strict_strtoul(string, 10, &option);
+			kfree(string);
+			if (rc != 0)
+				goto out_invalid_value;
+			mnt->acregmin = option;
 			break;
 		case Opt_acregmax:
-			if (match_int(args, &option) || option < 0) {
-				errors++;
-				nfs_parse_invalid_value("acregmax");
-			} else
-				mnt->acregmax = option;
+			string = match_strdup(args);
+			if (string == NULL)
+				goto out_nomem;
+			rc = strict_strtoul(string, 10, &option);
+			kfree(string);
+			if (rc != 0)
+				goto out_invalid_value;
+			mnt->acregmax = option;
 			break;
 		case Opt_acdirmin:
-			if (match_int(args, &option) || option < 0) {
-				errors++;
-				nfs_parse_invalid_value("acdirmin");
-			} else
-				mnt->acdirmin = option;
+			string = match_strdup(args);
+			if (string == NULL)
+				goto out_nomem;
+			rc = strict_strtoul(string, 10, &option);
+			kfree(string);
+			if (rc != 0)
+				goto out_invalid_value;
+			mnt->acdirmin = option;
 			break;
 		case Opt_acdirmax:
-			if (match_int(args, &option) || option < 0) {
-				errors++;
-				nfs_parse_invalid_value("acdirmax");
-			} else
-				mnt->acdirmax = option;
+			string = match_strdup(args);
+			if (string == NULL)
+				goto out_nomem;
+			rc = strict_strtoul(string, 10, &option);
+			kfree(string);
+			if (rc != 0)
+				goto out_invalid_value;
+			mnt->acdirmax = option;
 			break;
 		case Opt_actimeo:
-			if (match_int(args, &option) || option < 0) {
-				errors++;
-				nfs_parse_invalid_value("actimeo");
-			} else
-				mnt->acregmin = mnt->acregmax =
-				mnt->acdirmin = mnt->acdirmax = option;
+			string = match_strdup(args);
+			if (string == NULL)
+				goto out_nomem;
+			rc = strict_strtoul(string, 10, &option);
+			kfree(string);
+			if (rc != 0)
+				goto out_invalid_value;
+			mnt->acregmin = mnt->acregmax =
+			mnt->acdirmin = mnt->acdirmax = option;
 			break;
 		case Opt_namelen:
-			if (match_int(args, &option) || option < 0) {
-				errors++;
-				nfs_parse_invalid_value("namlen");
-			} else
-				mnt->namlen = option;
+			string = match_strdup(args);
+			if (string == NULL)
+				goto out_nomem;
+			rc = strict_strtoul(string, 10, &option);
+			kfree(string);
+			if (rc != 0)
+				goto out_invalid_value;
+			mnt->namlen = option;
 			break;
 		case Opt_mountport:
-			if (match_int(args, &option) ||
-			    option < 0 || option > USHORT_MAX) {
-				errors++;
-				nfs_parse_invalid_value("mountport");
-			} else
-				mnt->mount_server.port = option;
+			string = match_strdup(args);
+			if (string == NULL)
+				goto out_nomem;
+			rc = strict_strtoul(string, 10, &option);
+			kfree(string);
+			if (rc != 0 || option > USHORT_MAX)
+				goto out_invalid_value;
+			mnt->mount_server.port = option;
 			break;
 		case Opt_mountvers:
-			if (match_int(args, &option) ||
+			string = match_strdup(args);
+			if (string == NULL)
+				goto out_nomem;
+			rc = strict_strtoul(string, 10, &option);
+			kfree(string);
+			if (rc != 0 ||
 			    option < NFS_MNT_VERSION ||
-			    option > NFS_MNT3_VERSION) {
-				errors++;
-				nfs_parse_invalid_value("mountvers");
-			} else
-				mnt->mount_server.version = option;
+			    option > NFS_MNT3_VERSION)
+				goto out_invalid_value;
+			mnt->mount_server.version = option;
 			break;
 		case Opt_nfsvers:
-			if (match_int(args, &option)) {
-				errors++;
-				nfs_parse_invalid_value("nfsvers");
-				break;
-			}
+			string = match_strdup(args);
+			if (string == NULL)
+				goto out_nomem;
+			rc = strict_strtoul(string, 10, &option);
+			kfree(string);
+			if (rc != 0)
+				goto out_invalid_value;
 			switch (option) {
 			case NFS2_VERSION:
 				mnt->flags &= ~NFS_MOUNT_VER3;
@@ -1207,10 +1269,16 @@ static int nfs_parse_mount_options(char *raw,
 				mnt->flags |= NFS_MOUNT_VER3;
 				break;
 			default:
-				errors++;
-				nfs_parse_invalid_value("nfsvers");
+				goto out_invalid_value;
 			}
 			break;
+		case Opt_minorversion:
+			if (match_int(args, &int_option))
+				return 0;
+			if (int_option < 0 || int_option > NFS4_MAX_MINOR_VERSION)
+				return 0;
+			mnt->minorversion = int_option;
+			break;
 
 		/*
 		 * options that take text values
@@ -1222,9 +1290,9 @@ static int nfs_parse_mount_options(char *raw,
 			rc = nfs_parse_security_flavors(string, mnt);
 			kfree(string);
 			if (!rc) {
-				errors++;
 				dfprintk(MOUNT, "NFS:   unrecognized "
 						"security flavor\n");
+				return 0;
 			}
 			break;
 		case Opt_proto:
@@ -1238,23 +1306,25 @@ static int nfs_parse_mount_options(char *raw,
 			case Opt_xprt_udp:
 				mnt->flags &= ~NFS_MOUNT_TCP;
 				mnt->nfs_server.protocol = XPRT_TRANSPORT_UDP;
+				kfree(string);
 				break;
 			case Opt_xprt_tcp:
 				mnt->flags |= NFS_MOUNT_TCP;
 				mnt->nfs_server.protocol = XPRT_TRANSPORT_TCP;
+				kfree(string);
 				break;
 			case Opt_xprt_rdma:
 				/* vector side protocols to TCP */
 				mnt->flags |= NFS_MOUNT_TCP;
 				mnt->nfs_server.protocol = XPRT_TRANSPORT_RDMA;
 				xprt_load_transport(string);
+				kfree(string);
 				break;
 			default:
-				errors++;
 				dfprintk(MOUNT, "NFS:   unrecognized "
 						"transport protocol\n");
+				return 0;
 			}
-			kfree(string);
 			break;
 		case Opt_mountproto:
 			string = match_strdup(args);
@@ -1273,9 +1343,9 @@ static int nfs_parse_mount_options(char *raw,
 				break;
 			case Opt_xprt_rdma: /* not used for side protocols */
 			default:
-				errors++;
 				dfprintk(MOUNT, "NFS:   unrecognized "
 						"transport protocol\n");
+				return 0;
 			}
 			break;
 		case Opt_addr:
@@ -1331,9 +1401,9 @@ static int nfs_parse_mount_options(char *raw,
 					mnt->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
 					break;
 				default:
-					errors++;
 					dfprintk(MOUNT, "NFS:   invalid "
 							"lookupcache argument\n");
+					return 0;
 			};
 			break;
 
@@ -1351,20 +1421,20 @@ static int nfs_parse_mount_options(char *raw,
 			break;
 
 		default:
-			errors++;
+			invalid_option = 1;
 			dfprintk(MOUNT, "NFS:   unrecognized mount option "
 					"'%s'\n", p);
 		}
 	}
 
-	if (errors > 0) {
-		dfprintk(MOUNT, "NFS: parsing encountered %d error%s\n",
-				errors, (errors == 1 ? "" : "s"));
-		if (!sloppy)
-			return 0;
-	}
+	if (!sloppy && invalid_option)
+		return 0;
+
 	return 1;
 
+out_invalid_value:
+	printk(KERN_INFO "NFS: bad mount option value specified: %s \n", p);
+	return 0;
 out_nomem:
 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
 	return 0;
@@ -1381,6 +1451,7 @@ out_security_failure:
 static int nfs_try_mount(struct nfs_parsed_mount_data *args,
 			 struct nfs_fh *root_fh)
 {
+	unsigned int auth_flavor_len = 0;
 	struct nfs_mount_request request = {
 		.sap		= (struct sockaddr *)
 						&args->mount_server.address,
@@ -1388,6 +1459,7 @@ static int nfs_try_mount(struct nfs_parsed_mount_data *args,
 		.protocol	= args->mount_server.protocol,
 		.fh		= root_fh,
 		.noresvport	= args->flags & NFS_MOUNT_NORESVPORT,
+		.auth_flav_len	= &auth_flavor_len,
 	};
 	int status;
 
@@ -2240,6 +2312,11 @@ static void nfs4_fill_super(struct super_block *sb)
 	nfs_initialise_sb(sb);
 }
 
+static void nfs4_validate_mount_flags(struct nfs_parsed_mount_data *args)
+{
+	args->flags &= ~(NFS_MOUNT_NONLM|NFS_MOUNT_NOACL|NFS_MOUNT_VER3);
+}
+
 /*
  * Validate NFSv4 mount options
  */
@@ -2263,6 +2340,7 @@ static int nfs4_validate_mount_data(void *options,
 	args->nfs_server.port	= NFS_PORT; /* 2049 unless user set port= */
 	args->auth_flavors[0]	= RPC_AUTH_UNIX;
 	args->auth_flavor_len	= 0;
+	args->minorversion	= 0;
 
 	switch (data->version) {
 	case 1:
@@ -2336,6 +2414,8 @@ static int nfs4_validate_mount_data(void *options,
 
 		nfs_validate_transport_protocol(args);
 
+		nfs4_validate_mount_flags(args);
+
 		if (args->auth_flavor_len > 1)
 			goto out_inval_auth;
 
@@ -2375,12 +2455,12 @@ out_no_client_address:
 }
 
 /*
- * Get the superblock for an NFS4 mountpoint
+ * Get the superblock for the NFS4 root partition
  */
-static int nfs4_get_sb(struct file_system_type *fs_type,
+static int nfs4_remote_get_sb(struct file_system_type *fs_type,
 	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
 {
-	struct nfs_parsed_mount_data *data;
+	struct nfs_parsed_mount_data *data = raw_data;
 	struct super_block *s;
 	struct nfs_server *server;
 	struct nfs_fh *mntfh;
@@ -2391,18 +2471,12 @@ static int nfs4_get_sb(struct file_system_type *fs_type,
 	};
 	int error = -ENOMEM;
 
-	data = kzalloc(sizeof(*data), GFP_KERNEL);
 	mntfh = kzalloc(sizeof(*mntfh), GFP_KERNEL);
 	if (data == NULL || mntfh == NULL)
 		goto out_free_fh;
 
 	security_init_mnt_opts(&data->lsm_opts);
 
-	/* Validate the mount data */
-	error = nfs4_validate_mount_data(raw_data, data, dev_name);
-	if (error < 0)
-		goto out;
-
 	/* Get a volume representation */
 	server = nfs4_create_server(data, mntfh);
 	if (IS_ERR(server)) {
@@ -2415,7 +2489,7 @@ static int nfs4_get_sb(struct file_system_type *fs_type,
 		compare_super = NULL;
 
 	/* Get a superblock - note that we may end up sharing one that already exists */
-	s = sget(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_free;
@@ -2452,14 +2526,9 @@ static int nfs4_get_sb(struct file_system_type *fs_type,
 	error = 0;
 
 out:
-	kfree(data->client_address);
-	kfree(data->nfs_server.export_path);
-	kfree(data->nfs_server.hostname);
-	kfree(data->fscache_uniq);
 	security_free_mnt_opts(&data->lsm_opts);
 out_free_fh:
 	kfree(mntfh);
-	kfree(data);
 	return error;
 
 out_free:
@@ -2473,16 +2542,137 @@ error_splat_super:
 	goto out;
 }
 
+static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
+		int flags, void *data, const char *hostname)
+{
+	struct vfsmount *root_mnt;
+	char *root_devname;
+	size_t len;
+
+	len = strlen(hostname) + 3;
+	root_devname = kmalloc(len, GFP_KERNEL);
+	if (root_devname == NULL)
+		return ERR_PTR(-ENOMEM);
+	snprintf(root_devname, len, "%s:/", hostname);
+	root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
+	kfree(root_devname);
+	return root_mnt;
+}
+
+static void nfs_fix_devname(const struct path *path, struct vfsmount *mnt)
+{
+	char *page = (char *) __get_free_page(GFP_KERNEL);
+	char *devname, *tmp;
+
+	if (page == NULL)
+		return;
+	devname = nfs_path(path->mnt->mnt_devname,
+			path->mnt->mnt_root, path->dentry,
+			page, PAGE_SIZE);
+	if (devname == NULL)
+		goto out_freepage;
+	tmp = kstrdup(devname, GFP_KERNEL);
+	if (tmp == NULL)
+		goto out_freepage;
+	kfree(mnt->mnt_devname);
+	mnt->mnt_devname = tmp;
+out_freepage:
+	free_page((unsigned long)page);
+}
+
+static int nfs_follow_remote_path(struct vfsmount *root_mnt,
+		const char *export_path, struct vfsmount *mnt_target)
+{
+	struct mnt_namespace *ns_private;
+	struct nameidata nd;
+	struct super_block *s;
+	int ret;
+
+	ns_private = create_mnt_ns(root_mnt);
+	ret = PTR_ERR(ns_private);
+	if (IS_ERR(ns_private))
+		goto out_mntput;
+
+	ret = vfs_path_lookup(root_mnt->mnt_root, root_mnt,
+			export_path, LOOKUP_FOLLOW, &nd);
+
+	put_mnt_ns(ns_private);
+
+	if (ret != 0)
+		goto out_err;
+
+	s = nd.path.mnt->mnt_sb;
+	atomic_inc(&s->s_active);
+	mnt_target->mnt_sb = s;
+	mnt_target->mnt_root = dget(nd.path.dentry);
+
+	/* Correct the device pathname */
+	nfs_fix_devname(&nd.path, mnt_target);
+
+	path_put(&nd.path);
+	down_write(&s->s_umount);
+	return 0;
+out_mntput:
+	mntput(root_mnt);
+out_err:
+	return ret;
+}
+
+/*
+ * Get the superblock for an NFS4 mountpoint
+ */
+static int nfs4_get_sb(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
+{
+	struct nfs_parsed_mount_data *data;
+	char *export_path;
+	struct vfsmount *root_mnt;
+	int error = -ENOMEM;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (data == NULL)
+		goto out_free_data;
+
+	/* Validate the mount data */
+	error = nfs4_validate_mount_data(raw_data, data, dev_name);
+	if (error < 0)
+		goto out;
+
+	export_path = data->nfs_server.export_path;
+	data->nfs_server.export_path = "/";
+	root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, data,
+			data->nfs_server.hostname);
+	data->nfs_server.export_path = export_path;
+
+	error = PTR_ERR(root_mnt);
+	if (IS_ERR(root_mnt))
+		goto out;
+
+	error = nfs_follow_remote_path(root_mnt, export_path, mnt);
+
+out:
+	kfree(data->client_address);
+	kfree(data->nfs_server.export_path);
+	kfree(data->nfs_server.hostname);
+	kfree(data->fscache_uniq);
+out_free_data:
+	kfree(data);
+	dprintk("<-- nfs4_get_sb() = %d%s\n", error,
+			error != 0 ? " [error]" : "");
+	return error;
+}
+
 static void nfs4_kill_super(struct super_block *sb)
 {
 	struct nfs_server *server = NFS_SB(sb);
 
+	dprintk("--> %s\n", __func__);
 	nfs_super_return_all_delegations(sb);
 	kill_anon_super(sb);
-
 	nfs4_renewd_prepare_shutdown(server);
 	nfs_fscache_release_super_cookie(sb);
 	nfs_free_server(server);
+	dprintk("<-- %s\n", __func__);
 }
 
 /*
@@ -2568,12 +2758,9 @@ error_splat_super:
 	return error;
 }
 
-/*
- * Create an NFS4 server record on referral traversal
- */
-static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
-				const char *dev_name, void *raw_data,
-				struct vfsmount *mnt)
+static int nfs4_remote_referral_get_sb(struct file_system_type *fs_type,
+		int flags, const char *dev_name, void *raw_data,
+		struct vfsmount *mnt)
 {
 	struct nfs_clone_mount *data = raw_data;
 	struct super_block *s;
@@ -2652,4 +2839,36 @@ error_splat_super:
 	return error;
 }
 
+/*
+ * Create an NFS4 server record on referral traversal
+ */
+static int nfs4_referral_get_sb(struct file_system_type *fs_type,
+		int flags, const char *dev_name, void *raw_data,
+		struct vfsmount *mnt)
+{
+	struct nfs_clone_mount *data = raw_data;
+	char *export_path;
+	struct vfsmount *root_mnt;
+	int error;
+
+	dprintk("--> nfs4_referral_get_sb()\n");
+
+	export_path = data->mnt_path;
+	data->mnt_path = "/";
+
+	root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
+			flags, data, data->hostname);
+	data->mnt_path = export_path;
+
+	error = PTR_ERR(root_mnt);
+	if (IS_ERR(root_mnt))
+		goto out;
+
+	error = nfs_follow_remote_path(root_mnt, export_path, mnt);
+out:
+	dprintk("<-- nfs4_referral_get_sb() = %d%s\n", error,
+			error != 0 ? " [error]" : "");
+	return error;
+}
+
 #endif /* CONFIG_NFS_V4 */