diff -rup linux-2.6.18.5/fs/nfsd/export.c linux-2.6.18.5.zumastor/fs/nfsd/export.c
--- linux-2.6.18.5/fs/nfsd/export.c	2006-12-01 16:13:05.000000000 -0800
+++ linux-2.6.18.5.zumastor/fs/nfsd/export.c	2007-03-16 16:10:24.000000000 -0700
@@ -735,7 +735,7 @@ exp_readlock(void)
 	down_read(&hash_sem);
 }
 
-static inline void
+void
 exp_writelock(void)
 {
 	down_write(&hash_sem);
@@ -747,7 +747,7 @@ exp_readunlock(void)
 	up_read(&hash_sem);
 }
 
-static inline void
+void
 exp_writeunlock(void)
 {
 	up_write(&hash_sem);
@@ -1290,6 +1290,17 @@ exp_verify_string(char *cp, int max)
 }
 
 /*
+ * Flush exports table without calling RW semaphore.
+ * The caller is required to lock and unlock the export table.
+ */
+void
+export_purge(void)
+{
+	        cache_purge(&svc_expkey_cache);
+	        cache_purge(&svc_export_cache);
+}
+
+/*
  * Initialize the exports module.
  */
 void
diff -rup linux-2.6.18.5/fs/nfsd/nfsctl.c linux-2.6.18.5.zumastor/fs/nfsd/nfsctl.c
--- linux-2.6.18.5/fs/nfsd/nfsctl.c	2006-12-01 16:13:05.000000000 -0800
+++ linux-2.6.18.5.zumastor/fs/nfsd/nfsctl.c	2007-03-16 16:10:24.000000000 -0700
@@ -38,7 +38,7 @@
 unsigned int nfsd_versbits = ~0;
 
 /*
- *	We have a single directory with 9 nodes in it.
+ *	We have a single directory with several nodes in it.
  */
 enum {
 	NFSD_Root = 1,
@@ -53,6 +53,7 @@ enum {
 	NFSD_Fh,
 	NFSD_Threads,
 	NFSD_Versions,
+	NFSD_Suspend,
 	/*
 	 * The below MUST come last.  Otherwise we leave a hole in nfsd_files[]
 	 * with !CONFIG_NFSD_V4 and simple_fill_super() goes oops
@@ -139,6 +140,26 @@ static const struct file_operations tran
 	.release	= simple_transaction_release,
 };
 
+static ssize_t nfsctl_suspend_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
+{
+	printk("Suspending NFS transactions!\n");
+	exp_writelock();
+	export_purge();
+	return size;
+}
+
+static ssize_t nfsctl_suspend_read(struct file *file, char __user *buf, size_t size, loff_t *pos)
+{
+	printk("Resuming NFS transactions!\n");
+	exp_writeunlock();
+	return 0;
+}
+
+static struct file_operations suspend_ops = {
+	.write		= nfsctl_suspend_write,
+	.read		= nfsctl_suspend_read,
+};
+
 extern struct seq_operations nfs_exports_op;
 static int exports_open(struct inode *inode, struct file *file)
 {
@@ -484,6 +505,7 @@ static int nfsd_fill_super(struct super_
 		[NFSD_Fh] = {"filehandle", &transaction_ops, S_IWUSR|S_IRUSR},
 		[NFSD_Threads] = {"threads", &transaction_ops, S_IWUSR|S_IRUSR},
 		[NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR},
+		[NFSD_Suspend] = {"suspend", &suspend_ops, S_IWUSR|S_IRUSR},
 #ifdef CONFIG_NFSD_V4
 		[NFSD_Leasetime] = {"nfsv4leasetime", &transaction_ops, S_IWUSR|S_IRUSR},
 		[NFSD_RecoveryDir] = {"nfsv4recoverydir", &transaction_ops, S_IWUSR|S_IRUSR},
diff -rup linux-2.6.18.5/include/linux/nfsd/export.h linux-2.6.18.5.zumastor/include/linux/nfsd/export.h
--- linux-2.6.18.5/include/linux/nfsd/export.h	2006-12-01 16:13:05.000000000 -0800
+++ linux-2.6.18.5.zumastor/include/linux/nfsd/export.h	2007-03-16 16:10:24.000000000 -0700
@@ -84,6 +84,9 @@ struct svc_expkey {
 void			nfsd_export_init(void);
 void			nfsd_export_shutdown(void);
 void			nfsd_export_flush(void);
+void			export_purge(void);
+void			exp_writelock(void);
+void			exp_writeunlock(void);
 void			exp_readlock(void);
 void			exp_readunlock(void);
 struct svc_export *	exp_get_by_name(struct auth_domain *clp,