diff --git a/support/export/xtab.c b/support/export/xtab.c

index 3b1dcce..2a43193 100644

--- a/support/export/xtab.c

+++ b/support/export/xtab.c

@@ -19,7 +19,9 @@

 #include "exportfs.h"

 #include "xio.h"

 #include "xlog.h"

+#include "v4root.h"

+int v4root_needed;

 static void cond_rename(char *newfile, char *oldfile);

 static int

@@ -36,6 +38,8 @@ xtab_read(char *xtab, char *lockfn, int is_export)

 	if ((lockid = xflock(lockfn, "r")) < 0)

 		return 0;

 	setexportent(xtab, "r");

+	if (is_export == 1)

+		v4root_needed = 1;

 	while ((xp = getexportent(is_export==0, 0)) != NULL) {

 		if (!(exp = export_lookup(xp->e_hostname, xp->e_path, is_export != 1)) &&

 		    !(exp = export_create(xp, is_export!=1))) {

@@ -48,6 +52,8 @@ xtab_read(char *xtab, char *lockfn, int is_export)

 		case 1:

 			exp->m_xtabent = 1;

 			exp->m_mayexport = 1;

+			if ((xp->e_flags & NFSEXP_FSID) && xp->e_fsid == 0)

+				v4root_needed = 0;

 			break;

 		case 2:

 			exp->m_exported = -1;/* may be exported */

diff --git a/support/include/exportfs.h b/support/include/exportfs.h

index a5cf482..1ad41e2 100644

--- a/support/include/exportfs.h

+++ b/support/include/exportfs.h

@@ -12,6 +12,17 @@

 #include <netdb.h>

 #include "nfslib.h"

+enum nfsd_fsid {

+	FSID_DEV = 0,

+	FSID_NUM,

+	FSID_MAJOR_MINOR,

+	FSID_ENCODE_DEV,

+	FSID_UUID4_INUM,

+	FSID_UUID8,

+	FSID_UUID16,

+	FSID_UUID16_INUM,

+};

+

 enum {

 	MCL_FQDN = 0,

 	MCL_SUBNETWORK,

diff --git a/support/include/nfs/export.h b/support/include/nfs/export.h

index f7a99ba..76953ac 100644

--- a/support/include/nfs/export.h

+++ b/support/include/nfs/export.h

@@ -24,6 +24,7 @@

 #define NFSEXP_FSID		0x2000

 #define	NFSEXP_CROSSMOUNT	0x4000

 #define NFSEXP_NOACL		0x8000 /* reserved for possible ACL related use */

-#define NFSEXP_ALLFLAGS		0xFFFF

+#define NFSEXP_V4ROOT       0x10000

+#define NFSEXP_ALLFLAGS		0x1FFFF

 #endif /* _NSF_EXPORT_H */

diff --git a/support/include/nfslib.h b/support/include/nfslib.h

index 537a31e..e4777dd 100644

--- a/support/include/nfslib.h

+++ b/support/include/nfslib.h

@@ -88,6 +88,7 @@ struct exportent {

 	int             e_fslocmethod;

 	char *          e_fslocdata;

 	char *		e_uuid;

+	void *		e_v4root;

 	struct sec_entry e_secinfo[SECFLAVOR_COUNT+1];

 };

diff --git a/support/include/v4root.h b/support/include/v4root.h

new file mode 100644

index 0000000..43b1d2e

--- /dev/null

+++ b/support/include/v4root.h

@@ -0,0 +1,20 @@

+/*

+ * Copyright (C) 2009 Red Hat <nfs@redhat.com>

+ * support/include/v4root.h

+ *

+ * Support routines for dynamic pseudo roots.

+ *

+ */

+

+#ifndef V4ROOT_H

+#define V4ROOT_H

+

+extern int v4root_needed;

+

+extern struct exportent *v4root_chkroot(int , unsigned int , char *);

+extern struct exportent *v4root_export(char *, int);

+extern struct exportent *v4root_create(char *, nfs_export *, int);

+extern void v4root_free(struct exportent *);

+extern void v4root_unset(void), v4root_set(void);

+

+#endif /* V4ROOT_H */

diff --git a/utils/mountd/Makefile.am b/utils/mountd/Makefile.am

index 1e76cf8..eba81fc 100644

--- a/utils/mountd/Makefile.am

+++ b/utils/mountd/Makefile.am

@@ -8,7 +8,7 @@ KPREFIX		= @kprefix@

 sbin_PROGRAMS	= mountd

 mountd_SOURCES = mountd.c mount_dispatch.c auth.c rmtab.c cache.c \

-		 svc_run.c fsloc.c mountd.h

+		 svc_run.c fsloc.c v4root.c mountd.h

 mountd_LDADD = ../../support/export/libexport.a \

 	       ../../support/nfs/libnfs.a \

 	       ../../support/misc/libmisc.a \

diff --git a/utils/mountd/auth.c b/utils/mountd/auth.c

index 575f207..041a745 100644

--- a/utils/mountd/auth.c

+++ b/utils/mountd/auth.c

@@ -20,6 +20,7 @@

 #include "exportfs.h"

 #include "mountd.h"

 #include "xmalloc.h"

+#include "v4root.h"

 enum auth_error

 {

@@ -98,10 +99,13 @@ auth_reload()

 		last_inode = stb.st_ino;

 	}

+	v4root_unset();

 	export_freeall();

 	memset(&my_client, 0, sizeof(my_client));

 	xtab_export_read();

 	check_useipaddr();

+	v4root_set();

+

 	++counter;

 	return counter;

diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c

index e4e2f22..d631570 100644

--- a/utils/mountd/cache.c

+++ b/utils/mountd/cache.c

@@ -32,23 +32,12 @@

 #include "xmalloc.h"

 #include "fsloc.h"

 #include "pseudoflavors.h"

+#include "v4root.h"

 #ifdef USE_BLKID

 #include "blkid/blkid.h"

 #endif

-

-enum nfsd_fsid {

-	FSID_DEV = 0,

-	FSID_NUM,

-	FSID_MAJOR_MINOR,

-	FSID_ENCODE_DEV,

-	FSID_UUID4_INUM,

-	FSID_UUID8,

-	FSID_UUID16,

-	FSID_UUID16_INUM,

-};

-

 /*

  * Support routines for text-based upcalls.

  * Fields are separated by spaces.

@@ -135,6 +124,8 @@ void auth_unix_gid(FILE *f)

 	if (readline(fileno(f), &lbuf, &lbuflen) != 1)

 		return;

+	xlog(D_CALL, "auth_unix_gid: '%s'", lbuf);

+

 	cp = lbuf;

 	if (qword_get_int(&cp, &uid) != 0)

 		return;

@@ -391,6 +382,12 @@ void nfsd_fh(FILE *f)

 	auth_reload();

+	/* Check to see if the kenel is looking for the pseudo root */

+	if ((found = v4root_chkroot(fsidtype, fsidnum, fhuuid))) {

+		found_path = strdup(found->e_path);

+		goto found;

+	}

+

 	/* Now determine export point for this fsid/domain */

 	for (i=0 ; i < MCL_MAXTYPES; i++) {

 		nfs_export *next_exp;

@@ -511,7 +508,23 @@ void nfsd_fh(FILE *f)

 		 */

 		goto out;

 	}

+	if (!found) {

+		/*

+		 * See if this is a pesudo export

+		 */

+		switch(fsidtype) {

+		case FSID_UUID4_INUM:

+		case FSID_UUID8:

+		case FSID_UUID16:

+		case FSID_UUID16_INUM:

+			found = v4root_export(fhuuid, uuidlen);

+			break;

+		}

+		if (found)

+			found_path = strdup(found->e_path);

+	}

+found:

 	if (found)

 		if (cache_export_ent(dom, found, found_path) < 0)

 			found = 0;

@@ -629,6 +642,7 @@ void nfsd_export(FILE *f)

 	int found_type = 0;

 	struct in_addr addr;

 	struct hostent *he = NULL;

+	struct exportent *v4root = NULL;

 	if (readline(fileno(f), &lbuf, &lbuflen) != 1)

@@ -663,10 +677,18 @@ void nfsd_export(FILE *f)

 				     path[l] == '/' &&

 				     is_mountpoint(path)))

 					/* ok */;

-				else

+				else {

+					/* See if the path is part of the psuedo root */

+					if (v4root_needed && !v4root) 

+						v4root = v4root_create(path, exp, TRUE); 

 					continue;

-			} else if (strcmp(path, exp->m_export.e_path) != 0)

+				}

+			} else if (strcmp(path, exp->m_export.e_path) != 0) {

+				/* See if the path is part of the psuedo root */

+				if (v4root_needed && !v4root) 

+					v4root = v4root_create(path, exp, TRUE); 

 				continue;

+			}

 			if (use_ipaddr) {

 				if (he == NULL) {

 					if (!inet_aton(dom, &addr))

@@ -705,17 +727,28 @@ void nfsd_export(FILE *f)

 	}

 	if (found) {

+		xlog(D_CALL, "nfsd_export: found: path %s", path);

 		if (dump_to_cache(f, dom, path, &found->m_export) < 0) {

 			xlog(L_WARNING,

 			     "Cannot export %s, possibly unsupported filesystem"

 			     " or fsid= required", path);

 			dump_to_cache(f, dom, path, NULL);

 		}

-	} else {

+	} else if (v4root) {

+		xlog(D_CALL, "nfsd_export: vroot: path %s", path);

+		dump_to_cache(f, dom, path, v4root);

+		found = (nfs_export *)v4root;

+	} else { 

 		dump_to_cache(f, dom, path, NULL);

 	}

  out:

-	xlog(D_CALL, "nfsd_export: found %p path %s", found, path ? path : NULL);

+	/*

+	 * If a psuedo export was create and its not needed

+	 * free it up.

+	 */

+	if (v4root && found != (nfs_export *)v4root)

+		v4root_free(v4root);

+

 	if (dom) free(dom);

 	if (path) free(path);

 	if (he) free(he);

@@ -743,7 +776,9 @@ void cache_open(void)

 		if (!manage_gids && cachelist[i].cache_handle == auth_unix_gid)

 			continue;

 		sprintf(path, "/proc/net/rpc/%s/channel", cachelist[i].cache_name);

-		cachelist[i].f = fopen(path, "r+");

+		if ((cachelist[i].f = fopen(path, "r+")) == NULL)

+			xlog(L_ERROR, "cache_open: Unable to open '%s': errno %d (%s)", 

+				path, errno, strerror(errno));

 	}

 }

diff --git a/utils/mountd/v4root.c b/utils/mountd/v4root.c

new file mode 100644

index 0000000..8de2ab6

--- /dev/null

+++ b/utils/mountd/v4root.c

@@ -0,0 +1,420 @@

+/*

+ * Copyright (C) 2009 Red Hat <nfs@redhat.com>

+ *

+ * support/export/v4root.c

+ *

+ * Routines used to support NFSv4 pseudo roots

+ *

+ */

+

+#ifdef HAVE_CONFIG_H

+#include <config.h>

+#endif

+

+#include <sys/types.h>

+#include <sys/stat.h>

+#include <sys/queue.h>

+#include <stdio.h>

+#include <stdlib.h>

+#include <ctype.h>

+

+#include <uuid/uuid.h>

+#include <unistd.h>

+#include <errno.h>

+

+#include "xlog.h"

+#include "exportfs.h"

+#include "nfslib.h"

+#include "misc.h"

+#include "v4root.h"

+

+#ifndef _PATH_PSEUDO_ROOT

+#define _PATH_PSEUDO_ROOT		"/"

+#endif

+

+#ifndef _PSEUDO_ROOT_FSID

+#define _PSEUDO_ROOT_FSID	0

+#endif

+

+extern int get_uuid(char *path, char *uuid, int uuidlen, char *u);

+

+typedef struct _exports_t {

+	TAILQ_ENTRY(_exports_t) list;

+	char *path;

+	void *head;

+	char uuid_len;

+	char uuid[sizeof(uuid_t)];

+	struct exportent p_export;

+} exports_t;

+

+#define HASH_TABLE_SIZE 1021

+typedef struct _hash_head {

+	TAILQ_HEAD(export_list, _exports_t) h_head;

+} hash_head;

+hash_head exports_tbl[HASH_TABLE_SIZE];

+

+

+static exports_t *hash_export_lookup(char *, unsigned int);

+static void hash_export_add(struct _exports_t *, int);

+static void hash_mount_free(void);

+

+static inline unsigned int strtoint(char *str, int len)

+{

+	unsigned int n = 0;

+	int i;

+

+	for (i=0; i < len; i++)

+		n+=((int)str[i])*i;

+	return n;

+}

+static inline int hashint(unsigned int num)

+{

+	return num % HASH_TABLE_SIZE;

+}

+#define HASH(_s, _l) hashint(strtoint((_s), (_l)))

+void v4root_set(void);

+void v4root_unset(void);

+static int v4root_support(void);

+

+int v4root_needed;

+

+static nfs_export pr_export = {

+	.m_next = NULL,

+	.m_client = NULL,

+	.m_export = {

+		.e_hostname = "*",

+		.e_path = _PATH_PSEUDO_ROOT,

+		.e_flags = NFSEXP_READONLY | NFSEXP_ROOTSQUASH

+				| NFSEXP_NOSUBTREECHECK | NFSEXP_FSID

+				| NFSEXP_CROSSMOUNT | NFSEXP_V4ROOT,

+		.e_anonuid = 65534,

+		.e_anongid = 65534,

+		.e_squids = NULL,

+		.e_nsquids = 0,

+		.e_sqgids = NULL,

+		.e_nsqgids = 0,

+		.e_fsid = 0,

+		.e_mountpoint = NULL,

+	},

+	.m_exported = 0,

+	.m_xtabent = 1,

+	.m_mayexport = 1,

+	.m_changed = 0,

+	.m_warned = 0,

+};

+static nfs_export *pseudo_root;

+

+/*

+ * Return the number '/' in the path

+ */

+inline static int slash_count(char *path)

+{

+	int i, slashs=0;

+

+	for (i=0; i < strlen(path); i++) {

+			if (path[i] == '/')

+				slashs++;

+	}

+	return slashs;

+}

+/*

+ * Make sure the kernel has pseudo root support.

+ */

+static int

+v4root_support()

+{

+	static int kernel_support = -1;

+	char *ptr, version[64];

+	int major, minor;

+	FILE *fp;

+

+	if (kernel_support != -1)

+		return kernel_support;

+

+	kernel_support = 0;

+	fp = fopen("/proc/fs/nfsd/exports", "r");

+	if (fp == NULL)

+		goto out;

+

+	ptr = fgets(version, 64, fp);

+	fclose(fp);

+	if (ptr == NULL)

+		goto out;

+

+	while(*ptr && isdigit(*ptr) == 0)

+		ptr++;

+	if (*ptr == '\0')

+		goto out;

+

+	major = minor = 0;

+	sscanf(ptr, " %d.%d",&major, &minor);

+	if (major >= 1 && minor >= 2)

+		kernel_support = 1;

+out:

+	if (!kernel_support) {

+		xlog(L_WARNING, "Kernel does not have pseudo root support.");

+		xlog(L_WARNING, "NFS v4 mounts will be disabled unless fsid=0");

+		xlog(L_WARNING, "is specfied in /etc/exports file.");

+	}

+

+	return kernel_support;

+}

+/*

+ * Build a table of pseudo exports by running through

+ * the real export looking at the components of the path

+ * that make up the export. Those path components, if

+ * not exported, will become pseudo exports allowing them 

+ * to be found when the kernel does an upcall looking for 

+ * components of the v4 mount.

+ */

+void

+v4root_set()

+{

+	nfs_export	*exp, *nxt;

+	int	i, slcnt;

+	char *e_path, *path, *ptr, *comp;

+	char *hostname;

+

+	if (!v4root_needed)

+		return;

+

+	if (!v4root_support())

+		return;

+

+	pseudo_root = &pr_export;

+

+	for (i = 0; i < MCL_MAXTYPES; i++) {

+		for (exp = exportlist[i].p_head; exp; exp = nxt) {

+			nxt = exp->m_next;

+			e_path = exp->m_export.e_path;

+			hostname = exp->m_export.e_hostname;

+

+			slcnt = slash_count(e_path);

+			if (slcnt == 1)

+				continue;

+			slcnt--; /* knock off the leanding '/' */

+

+			path = strdup(e_path);

+			if (path == NULL) { 

+				xlog(L_WARNING, "v4root_set: No memory for pseudo export");

+				return;

+			}

+

+			/*

+			 * Run through each component of the path to

+			 * see if a  pseudo export should be created.

+			 */

+			comp = path+1;

+			do { 

+				if ((ptr = strchr(comp, '/')) != NULL)

+					*ptr = '\0';

+

+	  			if (export_lookup(hostname, path, 0) == NULL)

+					if (v4root_create(path, exp, FALSE) == NULL) {

+						xlog(L_WARNING, 

+							"v4root_set: Unable to create pseudo export"

+							"for '%s'", path);

+						break;

+					}

+

+				if (ptr) {

+					*ptr = '/';

+					comp = ptr+1; 

+				}

+			} while (--slcnt > 0);

+			free(path);

+		}

+	}

+}

+

+/*

+ * Unset the pseudo root export

+ */

+void

+v4root_unset()

+{

+	pseudo_root = NULL;

+	hash_mount_free();

+}

+

+/*

+ * The kernel will do an upcall looking for the pseudo

+ * root via its fsid. When the wanted fsid equals 

+ * PSEUDO_ROOT_FSID return the pseudo root export.

+ */

+struct exportent *

+v4root_chkroot(int fsidtype, unsigned int fsidnum, char *fhuuid)

+{

+	struct exportent *p_export = NULL;

+

+	if (pseudo_root == NULL)

+		return NULL;

+

+	switch(fsidtype) {

+		case FSID_NUM:

+			if (fsidnum == _PSEUDO_ROOT_FSID) {

+				p_export = &pseudo_root->m_export;

+				strncpy(p_export->e_path, _PATH_PSEUDO_ROOT, 

+					NFS_MAXPATHLEN);

+			}

+			break;

+	}

+

+	return p_export;

+}

+

+/*

+ * Create a pseudo export, if one does not 

+ * already exist.

+ */

+struct exportent *

+v4root_create(char *path, nfs_export *exp, int docheck)

+{

+	static struct exportent *p_export = NULL;

+	exports_t *pexp;

+	char *epath = exp->m_export.e_path;

+	int elen, plen;

+	char uuid_len = sizeof(uuid_t);

+	char uuid[sizeof(uuid_t)];

+

+	if (pseudo_root == NULL)

+		return NULL;

+

+	if (docheck) {

+

+		/* Path needs to be a subset of e_path */

+		elen = strlen(epath);

+		plen = strlen(path);

+		if (plen >= elen)

+			return NULL;

+

+		if (memcmp(path, epath, plen) != 0)

+			return NULL;

+	}

+

+	/* Check to see if the export already exists */

+	get_uuid(path, NULL, uuid_len, uuid);

+	if ((p_export = v4root_export(uuid, uuid_len)) != NULL)

+		return p_export;

+

+	pexp = (exports_t *)malloc(sizeof(exports_t));

+	if (pexp == NULL) {

+		xlog(L_WARNING, "v4root_create: No memory for pseudo export");

+		return NULL;

+	}

+	p_export = &pexp->p_export;

+	pexp->path = strdup(path);

+	if (pexp->path == 0) {

+		xlog(L_WARNING, "v4root_create: No memory for pseudo path");

+		free(pexp);

+		return NULL;

+	}

+	pexp->uuid_len = uuid_len;

+	memcpy(pexp->uuid, uuid, uuid_len);

+

+	dupexportent(&pexp->p_export, &pr_export.m_export);

+	strcpy(p_export->e_path, path);

+	p_export->e_flags &= ~NFSEXP_FSID;

+	p_export->e_v4root = (void *)pexp;

+

+	hash_export_add(pexp, HASH(pexp->uuid, sizeof(uuid_t)));

+

+	xlog(D_CALL, "v4root_create: path '%s'", p_export->e_path);

+

+	return p_export;

+}

+

+/*

+ * Free a pseudo export

+ */

+void

+v4root_free(struct exportent *p_export)

+{

+	exports_t *pexp = (exports_t *)p_export->e_v4root;

+	hash_head *head = (hash_head *)pexp->head;

+

+	free(pexp->path);

+	TAILQ_REMOVE(&head->h_head, pexp, list);

+}

+

+/*

+ * Return a pseudo export that match the given uuid

+ */

+struct exportent *

+v4root_export(char *fhuuid, int uuidlen)

+{

+	struct exportent *p_export = NULL;

+	exports_t *pexp;

+	int len = MIN(uuidlen, sizeof(uuid_t));

+

+	if (pseudo_root == NULL)

+		return NULL;

+

+	pexp = hash_export_lookup(fhuuid, len);

+	if (pexp) {

+		p_export = &pexp->p_export;

+		xlog(D_CALL, "v4root_export: path %s", p_export->e_path);

+	}

+	return p_export;

+}

+

+/*

+ * Add pseudo export to export table

+ */

+static void hash_export_add(struct _exports_t *exp, int hash)

+{

+	hash_head *head;

+

+	head = &(exports_tbl[hash]);

+	exp->head = head;

+

+	if (TAILQ_EMPTY(&head->h_head))

+		TAILQ_INSERT_HEAD(&head->h_head, exp, list);

+	else

+		TAILQ_INSERT_TAIL(&head->h_head, exp, list);

+}

+

+/*

+ * Lookup a pseudo export using the uuid and inode number

+ */

+static exports_t *

+hash_export_lookup(char *uuid, unsigned int uuidlen)

+{

+	exports_t *pexp;

+	hash_head *head;

+	int hash = HASH(uuid, uuidlen);

+

+	head = &(exports_tbl[hash]);

+

+	TAILQ_FOREACH(pexp, &head->h_head, list) {

+		if (memcmp(pexp->uuid, uuid, uuidlen) == 0)

+			return pexp;

+	}

+	return NULL;

+

+}

+

+/*

+ * Free up pseudo export table

+ */

+static void hash_mount_free()

+{

+	hash_head *head;

+	exports_t *e1, *e2;

+	int hash;

+

+	for (hash=0; hash < HASH_TABLE_SIZE; hash++) {

+		head = &(exports_tbl[hash]);

+		if (head == NULL)

+			continue;

+		e1 = TAILQ_FIRST(&head->h_head);

+		while (e1 != NULL) {

+			free(e1->path);

+			e2 =  TAILQ_NEXT(e1, list);

+			TAILQ_REMOVE(&head->h_head, e1, list);

+			free(e1);

+			e1 = e2;

+		}

+		TAILQ_INIT(&head->h_head);

+	}

+}