diff -ru /usr/src/sys/nfs/nfs.h /usr/src/sys/nfs.noac/nfs.h
--- /usr/src/sys/nfs/nfs.h	2005-01-11 01:39:46.000000000 -0500
+++ /usr/src/sys/nfs.noac/nfs.h	2005-09-18 19:41:02.000000000 -0400
@@ -168,11 +168,12 @@
 /*
  * Set the attribute timeout based on how recently the file has been modified.
  */
-#define	NFS_ATTRTIMEO(np) \
+#define	NFS_ATTRTIMEO(nmp, np) \
+    ((nmp->nm_flag & NFSMNT_NOAC) ? 0 : \
 	((((np)->n_flag & NMODIFIED) || \
 	 (time.tv_sec - (np)->n_mtime.tv_sec) / 10 < NFS_MINATTRTIMO) ? NFS_MINATTRTIMO : \
 	 ((time.tv_sec - (np)->n_mtime.tv_sec) / 10 > NFS_MAXATTRTIMO ? NFS_MAXATTRTIMO : \
-	  (time.tv_sec - (np)->n_mtime.tv_sec) / 10))
+	  (time.tv_sec - (np)->n_mtime.tv_sec) / 10)))
 
 /*
  * Expected allocation sizes for major data structures. If the actual size
diff -ru /usr/src/sys/nfs/nfs_subs.c /usr/src/sys/nfs.noac/nfs_subs.c
--- /usr/src/sys/nfs/nfs_subs.c	2005-03-16 06:54:49.000000000 -0500
+++ /usr/src/sys/nfs.noac/nfs_subs.c	2005-09-18 19:45:08.000000000 -0400
@@ -1865,10 +1865,11 @@
 	struct vattr *vaper;
 {
 	struct nfsnode *np = VTONFS(vp);
+ 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
 	struct vattr *vap;
 
 	if (np->n_attrstamp == 0 ||
-	    (time.tv_sec - np->n_attrstamp) >= NFS_ATTRTIMEO(np)) {
+	    (time.tv_sec - np->n_attrstamp) >= NFS_ATTRTIMEO(nmp, np)) {
 		nfsstats.attrcache_misses++;
 		return (ENOENT);
 	}
diff -ru /usr/src/sys/nfs/nfs_vfsops.c /usr/src/sys/nfs.noac/nfs_vfsops.c
--- /usr/src/sys/nfs/nfs_vfsops.c	2004-05-29 05:04:02.000000000 -0400
+++ /usr/src/sys/nfs.noac/nfs_vfsops.c	2005-09-18 19:41:02.000000000 -0400
@@ -302,7 +302,7 @@
 	 * XXX time must be non-zero when we init the interface or else
 	 * the arp code will wedge.  [Fixed now in if_ether.c]
 	 * However, the NFS attribute cache gives false "hits" when
-	 * time.tv_sec < NFS_ATTRTIMEO(np) so keep this in for now.
+	 * time.tv_sec < NFS_ATTRTIMEO(nmp, np) so keep this in for now.
 	 */
 	if (time.tv_sec < NFS_MAXATTRTIMO)
 		time.tv_sec = NFS_MAXATTRTIMO;
diff -ru /usr/src/sys/nfs/nfs_vnops.c /usr/src/sys/nfs.noac/nfs_vnops.c
--- /usr/src/sys/nfs/nfs_vnops.c	2005-03-16 07:50:30.000000000 -0500
+++ /usr/src/sys/nfs.noac/nfs_vnops.c	2005-09-18 19:47:41.000000000 -0400
@@ -333,9 +333,10 @@
 	u_int32_t mode, rmode;
 	const int v3 = NFS_ISV3(vp);
 	struct nfsnode *np = VTONFS(vp);
+ 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
 
 	cachevalid = (np->n_accstamp != -1 &&
-	    (time.tv_sec - np->n_accstamp) < NFS_ATTRTIMEO(np) &&
+	    (time.tv_sec - np->n_accstamp) < NFS_ATTRTIMEO(nmp, np) &&
 	    np->n_accuid == ap->a_cred->cr_uid);
 
 	/*
diff -ru /usr/src/sys/nfs/nfsmount.h /usr/src/sys/nfs.noac/nfsmount.h
--- /usr/src/sys/nfs/nfsmount.h	2003-10-03 12:34:31.000000000 -0400
+++ /usr/src/sys/nfs.noac/nfsmount.h	2005-09-18 19:41:02.000000000 -0400
@@ -85,13 +85,14 @@
 #define	NFSMNT_RDIRPLUS		0x00010000  /* Use Readdirplus for V3 */
 #define	NFSMNT_READDIRSIZE	0x00020000  /* Set readdir size */
 #define NFSMNT_XLATECOOKIE	0x00040000  /* 32<->64 dir cookie xlation */
+#define	NFSMNT_NOAC		0x00080000  /* Turn off attribute cache */
 
 #define NFSMNT_BITS	"\177\20" \
     "b\00soft\0b\01wsize\0b\02rsize\0b\03timeo\0" \
     "b\04retrans\0b\05maxgrps\0b\06intr\0b\07noconn\0" \
     "b\10nqnfs\0b\11nfsv3\0b\12kerb\0b\13dumbtimr\0" \
     "b\14leaseterm\0b\15readahead\0b\16deadthresh\0b\17resvport\0" \
-    "b\20rdirplus\0b\21readdirsize\0b\22xlatecookie\0"
+    "b\20rdirplus\0b\21readdirsize\0b\22xlatecookie\0b\23noac\0"
 
 /*
  * NFS internal flags (nm_iflag) */