diff -up nfs-utils-1.0.9/utils/mount/nfs.man.orig nfs-utils-1.0.9/utils/mount/nfs.man
--- nfs-utils-1.0.9/utils/mount/nfs.man.orig	2009-05-01 09:03:23.729039000 -0700
+++ nfs-utils-1.0.9/utils/mount/nfs.man	2009-05-01 10:31:59.005578000 -0700
@@ -302,6 +302,28 @@ options.
 Use of this option is not recommended unless you are certain that there
 are no hard links or subtrees of this mountpoint that are mounted
 elsewhere.
+.TP 1.5i
+.I lookupcache=type
+This option dictates how directories and files should be cached when 
+they are accessed -- i.e. "looked up" -- on the server. A lookup 
+can be either positive (directory/file was found) or 
+negative (directory/file was not found); both types of lookups can be cached.
+.br
+.sp
+By default, both positive and negative lookups are cached (
+.B lookupcache=all
+).  
+.B lookupcache=pos 
+prevents negative lookups from being cached, while  
+.B lookupcache=none 
+prevents all lookups from being cached. 
+.br
+.sp
+.B Note: 
+lookupcache=none 
+can adversely affect performance, but may be necessary 
+if shared files created or deleted on the server need to be immediately 
+visible to any applications running on NFS clients. 
 .P
 All of the non-value options have corresponding nooption forms.
 For example, nointr means don't allow file operations to be
diff -up nfs-utils-1.0.9/utils/mount/nfsmount.c.orig nfs-utils-1.0.9/utils/mount/nfsmount.c
--- nfs-utils-1.0.9/utils/mount/nfsmount.c.orig	2009-05-01 09:03:23.733038000 -0700
+++ nfs-utils-1.0.9/utils/mount/nfsmount.c	2009-05-01 09:05:14.003778000 -0700
@@ -704,6 +704,19 @@ parse_options(char *old_opts, struct nfs
 				else
 					strncpy(data->context, context, 
 							NFS_MAX_CONTEXT_LEN);
+			} else if (!strcmp(opt, "lookupcache")) {
+				char *lookupcache = opteq + 1;
+				if (!strcmp(lookupcache, "all")) {
+					data->flags &= ~(NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE);
+				} else if (!strcmp(lookupcache, "pos") || !strcmp(lookupcache, "positive")) {
+					data->flags &= ~NFS_MOUNT_LOOKUP_CACHE_NONE;
+					data->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG;
+				} else if (!strcmp(lookupcache, "none")) {
+					data->flags |= NFS_MOUNT_LOOKUP_CACHE_NONEG|NFS_MOUNT_LOOKUP_CACHE_NONE;
+				} else if (!sloppy) {
+					printf(_("Warning: Unrecognized lookupcache option %s\n"), lookupcache);
+					goto bad_parameter;
+				}
  			} else if (!sloppy)
 				goto bad_parameter;
 			sprintf(cbuf, "%s=%s,", opt, opteq+1);
diff -up nfs-utils-1.0.9/utils/mount/nfs_mount.h.orig nfs-utils-1.0.9/utils/mount/nfs_mount.h
--- nfs-utils-1.0.9/utils/mount/nfs_mount.h.orig	2009-05-01 09:03:23.736039000 -0700
+++ nfs-utils-1.0.9/utils/mount/nfs_mount.h	2009-05-01 09:05:14.008779000 -0700
@@ -65,7 +65,8 @@ struct nfs_mount_data {
 #define NFS_MOUNT_SECFLAVOUR	0x2000	/* 5 */
 #define NFS_MOUNT_NORDIRPLUS	0x8000	/* 5 */
 #define NFS_MOUNT_UNSHARED		0x10000	/* 5 */
-
+#define NFS_MOUNT_LOOKUP_CACHE_NONEG	0x20000
+#define NFS_MOUNT_LOOKUP_CACHE_NONE	0x40000
 
 /* security pseudoflavors */