diff -puN fs/nfsd/export.c~nfs_suspend fs/nfsd/export.c
--- linux-2.6.21.1/fs/nfsd/export.c~nfs_suspend	2007-07-19 16:51:00.000000000 -0700
+++ linux-2.6.21.1-root/fs/nfsd/export.c	2007-07-19 16:51:00.000000000 -0700
@@ -874,7 +874,7 @@ exp_readlock(void)
 	down_read(&hash_sem);
 }
 
-static inline void
+void
 exp_writelock(void)
 {
 	down_write(&hash_sem);
@@ -886,7 +886,7 @@ exp_readunlock(void)
 	up_read(&hash_sem);
 }
 
-static inline void
+void
 exp_writeunlock(void)
 {
 	up_write(&hash_sem);
@@ -1444,6 +1444,17 @@ 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 -puN fs/nfsd/nfsctl.c~nfs_suspend fs/nfsd/nfsctl.c
--- linux-2.6.21.1/fs/nfsd/nfsctl.c~nfs_suspend	2007-07-19 16:51:00.000000000 -0700
+++ linux-2.6.21.1-root/fs/nfsd/nfsctl.c	2007-07-19 16:51:00.000000000 -0700
@@ -40,7 +40,7 @@
 #include <asm/uaccess.h>
 
 /*
- *	We have a single directory with 9 nodes in it.
+ *	We have a single directory with several nodes in it.
  */
 enum {
 	NFSD_Root = 1,
@@ -58,6 +58,7 @@ enum {
 	NFSD_Versions,
 	NFSD_Ports,
 	NFSD_MaxBlkSize,
+	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
@@ -150,6 +151,26 @@ 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)
 {
@@ -653,6 +674,7 @@ static int nfsd_fill_super(struct super_
 		[NFSD_Versions] = {"versions", &transaction_ops, S_IWUSR|S_IRUSR},
 		[NFSD_Ports] = {"portlist", &transaction_ops, S_IWUSR|S_IRUGO},
 		[NFSD_MaxBlkSize] = {"max_block_size", &transaction_ops, S_IWUSR|S_IRUGO},
+		[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 -puN include/linux/nfsd/export.h~nfs_suspend include/linux/nfsd/export.h
--- linux-2.6.21.1/include/linux/nfsd/export.h~nfs_suspend	2007-07-19 16:51:00.000000000 -0700
+++ linux-2.6.21.1-root/include/linux/nfsd/export.h	2007-07-19 16:51:00.000000000 -0700
@@ -106,6 +106,9 @@ 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,