--- fs/nfs.orig/file.c	Thu Jul 13 18:51:06 2000
+++ fs/nfs/file.c	Thu Jul 13 19:15:58 2000
@@ -37,6 +37,8 @@
 static ssize_t nfs_file_write(struct file *, const char *, size_t, loff_t *);
 static int  nfs_file_flush(struct file *);
 static int  nfs_fsync(struct file *, struct dentry *dentry);
+static int nfs_file_ioctl(struct inode * inode, struct file *filp,
+			  unsigned int cmd, unsigned long arg);
 
 static struct file_operations nfs_file_operations = {
 	NULL,			/* lseek - default */
@@ -44,7 +46,7 @@
 	nfs_file_write,		/* write */
 	NULL,			/* readdir - bad */
 	NULL,			/* select - default */
-	NULL,			/* ioctl - default */
+	nfs_file_ioctl,		/* ioctl */
 	nfs_file_mmap,		/* mmap */
 	nfs_open,		/* open */
 	nfs_file_flush,		/* flush */
@@ -118,6 +120,20 @@
 	if (!result)
 		result = generic_file_read(file, buf, count, ppos);
 	return result;
+}
+
+static int
+nfs_file_ioctl(struct inode * inode, struct file *filp, unsigned int cmd,
+	       unsigned long arg)
+{
+	switch (cmd) {
+	case NFS_IOC_ZAP_CACHES:
+		nfs_zap_caches(inode);
+		return 0;
+		break;
+	default:
+		return -EINVAL;
+	}
 }
 
 static int
--- fs/nfs.orig/inode.c	Thu Jul 13 18:51:06 2000
+++ fs/nfs/inode.c	Thu Jul 13 19:08:03 2000
@@ -37,7 +37,6 @@
 #define NFS_PARANOIA 1
 
 static struct inode * __nfs_fhget(struct super_block *, struct nfs_fattr *);
-static void nfs_zap_caches(struct inode *);
 static void nfs_invalidate_inode(struct inode *);
 
 static void nfs_read_inode(struct inode *);
@@ -432,7 +431,7 @@
 /*
  * Invalidate the local caches
  */
-static void
+void
 nfs_zap_caches(struct inode *inode)
 {
 	NFS_ATTRTIMEO(inode) = NFS_MINATTRTIMEO(inode);
--- include/linux/nfs_fs.h.orig	Thu Jul 13 19:03:21 2000
+++ include/linux/nfs_fs.h	Thu Jul 13 19:09:47 2000
@@ -17,6 +17,8 @@
 #include <linux/nfs.h>
 #include <linux/nfs_mount.h>
 
+#include <linux/ioctl.h>
+
 /*
  * Enable debugging support for nfs client.
  * Requires RPC_DEBUG.
@@ -25,6 +27,8 @@
 # define NFS_DEBUG
 #endif
 
+#define NFS_IOC_ZAP_CACHES _IO('d', 0)
+
 /*
  * NFS_MAX_DIRCACHE controls the number of simultaneously cached
  * directory chunks. Each chunk holds the list of nfs_entry's returned
@@ -184,6 +188,7 @@
 extern int nfs_open(struct inode *, struct file *);
 extern int nfs_release(struct inode *, struct file *);
 extern int _nfs_revalidate_inode(struct nfs_server *, struct dentry *);
+extern void nfs_zap_caches(struct inode *inode);
 
 /*
  * linux/fs/nfs/file.c