diff --git a/utils/mount/parse_opt.c b/utils/mount/parse_opt.c

index 1dfee8a..f0918f7 100644

--- a/utils/mount/parse_opt.c

+++ b/utils/mount/parse_opt.c

@@ -101,6 +101,37 @@ fail:

 	return NULL;

 }

+static struct mount_option *option_dup(const struct mount_option *option)

+{

+	struct mount_option *new;

+

+	new = malloc(sizeof(*new));

+	if (!new)

+		return NULL;

+	

+	new->next = NULL;

+	new->prev = NULL;

+

+	new->keyword = strdup(option->keyword);

+	if (!new->keyword)

+		goto fail;

+

+	new->value = NULL;

+	if (option->value) {

+		new->value = strdup(option->value);

+		if (!new->value) {

+			free(new->keyword);

+			goto fail;

+		}

+	}

+

+	return new;

+

+fail:

+	free(new);

+	return NULL;

+}

+

 static void option_destroy(struct mount_option *option)

 {

 	free(option->keyword);

@@ -229,6 +260,40 @@ fail:

 }

 /**

+ * po_dup - duplicate an existing list of options

+ * @options: pointer to mount options

+ *

+ */

+struct mount_options *po_dup(struct mount_options *source)

+{

+	struct mount_options *target;

+	struct mount_option *current;

+

+	if (!source)

+		return NULL;

+

+	target = options_create();

+	if (options_empty(source) || target == NULL)

+		return target;

+

+	current = source->head;

+	while (target->count < source->count) {

+		struct mount_option *option;

+

+		option = option_dup(current);

+		if (!option) {

+			po_destroy(target);

+			return NULL;

+		}

+

+		options_tail_insert(target, option);

+		current = current->next;

+	}

+

+	return target;

+}

+

+/**

  * po_replace - replace mount options in one mount_options object with another

  * @target: pointer to previously instantiated object to replace

  * @source: pointer to object containing source mount options

diff --git a/utils/mount/parse_opt.h b/utils/mount/parse_opt.h

index f9243c3..2c0b5f4 100644

--- a/utils/mount/parse_opt.h

+++ b/utils/mount/parse_opt.h

@@ -38,6 +38,7 @@ typedef enum {

 struct mount_options;

 struct mount_options *	po_split(char *);

+struct mount_options *	po_dup(struct mount_options *);

 void			po_replace(struct mount_options *,

 				   struct mount_options *);

 po_return_t		po_join(struct mount_options *, char **);

diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c

index 3eb661e..069bdc1 100644

--- a/utils/mount/stropts.c

+++ b/utils/mount/stropts.c

@@ -80,6 +80,8 @@ struct nfsmount_info {

 				*node,		/* mounted-on dir */

 				*type;		/* "nfs" or "nfs4" */

 	char			*hostname;	/* server's hostname */

+	struct sockaddr_storage	address;	/* server's address */

+	socklen_t		salen;		/* size of server's address */

 	struct mount_options	*options;	/* parsed mount options */

 	char			**extra_opts;	/* string for /etc/mtab */

@@ -257,47 +259,35 @@ static int nfs_append_sloppy_option(struct mount_options *options)

 }

 /*

- * Set up mandatory NFS mount options.

+ * Set up mandatory non-version specific NFS mount options.

  *

  * Returns 1 if successful; otherwise zero.

  */

 static int nfs_validate_options(struct nfsmount_info *mi)

 {

-	struct sockaddr_storage dummy;

-	struct sockaddr *sap = (struct sockaddr *)&dummy;

-	socklen_t salen = sizeof(dummy);

+	struct sockaddr *sap = (struct sockaddr *)&mi->address;

 	if (!nfs_parse_devname(mi->spec, &mi->hostname, NULL))

 		return 0;

-	if (!nfs_name_to_address(mi->hostname, sap, &salen))

+	mi->salen = sizeof(mi->address);

+	if (!nfs_name_to_address(mi->hostname, sap, &mi->salen))

 		return 0;

 	if (!nfs_nfs_version(mi->options, &mi->version))

 		return 0;

 	if (strncmp(mi->type, "nfs4", 4) == 0)

 		mi->version = 4;

-

-	if (mi->version == 4) {

-		if (!nfs_append_clientaddr_option(sap, salen, mi->options))

-			return 0;

-	} else {

-		if (!nfs_fix_mounthost_option(mi->options))

-			return 0;

-		if (!mi->fake && !nfs_verify_lock_option(mi->options))

-			return 0;

+	else {

+		char *option = po_get(mi->options, "proto");

+		if (option && strcmp(option, "rdma") == 0)

+			mi->version = 3;

 	}

 	if (!nfs_append_sloppy_option(mi->options))

 		return 0;

-	if (!nfs_append_addr_option(sap, salen, mi->options))

-		return 0;

-

-	/*

-	 * Update option string to be recorded in /etc/mnttab

-	 */

-	if (po_join(mi->options, mi->extra_opts) == PO_FAILED)

+	if (!nfs_append_addr_option(sap, mi->salen, mi->options))

 		return 0;

 	return 1;

@@ -489,17 +479,12 @@ out:

  * Returns TRUE if successful, otherwise FALSE.

  * "errno" is set to reflect the individual error.

  */

-static int nfs_try_mount(struct nfsmount_info *mi)

+static int nfs_sys_mount(struct nfsmount_info *mi, struct mount_options *opts)

 {

 	char *options = NULL;

 	int result;

-	if (mi->version != 4) {

-		if (!nfs_rewrite_pmap_mount_options(mi->options))

-			return 0;

-	}

-

-	if (po_join(mi->options, &options) == PO_FAILED) {

+	if (po_join(opts, &options) == PO_FAILED) {

 		errno = EIO;

 		return 0;

 	}

@@ -522,6 +507,121 @@ static int nfs_try_mount(struct nfsmount_info *mi)

 }

 /*

+ * For "-t nfs vers=2" or "-t nfs vers=3" mounts.

+ */

+static int nfs_try_mount_v3v2(struct nfsmount_info *mi)

+{

+	struct mount_options *options = po_dup(mi->options);

+	int result = 0;

+

+	if (!options) {

+		errno = ENOMEM;

+		return result;

+	}

+

+	if (!nfs_fix_mounthost_option(options)) {

+		errno = EINVAL;

+		goto out_fail;

+	}

+	if (!mi->fake && !nfs_verify_lock_option(options)) {

+		errno = EINVAL;

+		goto out_fail;

+	}

+

+	/*

+	 * Options we negotiate below may be stale by the time this

+	 * file system is unmounted.  In order to force umount.nfs

+	 * to renegotiate with the server, only write the user-

+	 * specified options, and not negotiated options, to /etc/mtab.

+	 */

+	if (po_join(options, mi->extra_opts) == PO_FAILED) {

+		errno = ENOMEM;

+		goto out_fail;

+	}

+

+	if (!nfs_rewrite_pmap_mount_options(options))

+		goto out_fail;

+

+	result = nfs_sys_mount(mi, options);

+

+out_fail:

+	po_destroy(options);

+	return result;

+}

+

+/*

+ * For "-t nfs -o vers=4" or "-t nfs4" mounts.

+ */

+static int nfs_try_mount_v4(struct nfsmount_info *mi)

+{

+	struct sockaddr *sap = (struct sockaddr *)&mi->address;

+	struct mount_options *options = po_dup(mi->options);

+	int result = 0;

+

+	if (!options) {

+		errno = ENOMEM;

+		return result;

+	}

+

+	if (mi->version == 0) {

+		if (po_append(options, "vers=4") == PO_FAILED) {

+			errno = EINVAL;

+			goto out_fail;

+		}

+	}

+

+	if (!nfs_append_clientaddr_option(sap, mi->salen, options)) {

+		errno = EINVAL;

+		goto out_fail;

+	}

+	/*

+	 * Update option string to be recorded in /etc/mtab.

+	 */

+	if (po_join(options, mi->extra_opts) == PO_FAILED) {

+		errno = ENOMEM;

+		return 0;

+	}

+

+	result = nfs_sys_mount(mi, options);

+

+out_fail:

+	po_destroy(options);

+	return result;

+}

+

+/*

+ * This is a single pass through the fg/bg loop.

+ *

+ * Returns TRUE if successful, otherwise FALSE.

+ * "errno" is set to reflect the individual error.

+ */

+static int nfs_try_mount(struct nfsmount_info *mi)

+{

+	int result = 0;

+

+	switch (mi->version) {

+	case 0:

+		if (linux_version_code() > MAKE_VERSION(2, 6, 31)) {

+			errno = 0;

+			result = nfs_try_mount_v4(mi);

+			if (errno != EPROTONOSUPPORT)

+				break;

+		}

+	case 2:

+	case 3:

+		result = nfs_try_mount_v3v2(mi);

+		break;

+	case 4:

+		result = nfs_try_mount_v4(mi);

+		break;

+	default:

+		errno = EIO;

+	}

+

+	return result;

+}

+

+/*

  * Distinguish between permanent and temporary errors.

  *

  * Basically, we retry if communication with the server has