Index: sys/kern/vfs_lookup.c
===================================================================
--- sys/kern/vfs_lookup.c	(revision 166)
+++ sys/kern/vfs_lookup.c	(working copy)
@@ -461,6 +461,7 @@
 		/* XXX This should probably move to the top of function. */
 		if (cnp->cn_flags & SAVESTART)
 			panic("lookup: SAVESTART");
+		printf("success without updating parentdir %p\n", dp);
 		goto success;
 	}
 
@@ -690,6 +691,13 @@
 		ndp->ni_startdir = ndp->ni_dvp;
 		VREF(ndp->ni_startdir);
 	}
+
+	if (dp->v_watched && ndp->ni_vp && ndp->ni_vp != dp) {
+		printf("updating parentdir vp %p par %p\n", ndp->ni_vp, dp);
+		ndp->ni_vp->v_parentdir = dp;
+		RB_INSERT(vn_rb_tree, &dp->v_subwatched, ndp->ni_vp);
+	}
+
 	if (!wantparent) {
 		if (ndp->ni_dvp != dp)
 			vput(ndp->ni_dvp);
Index: sys/kern/kern_event.c
===================================================================
--- sys/kern/kern_event.c	(revision 167)
+++ sys/kern/kern_event.c	(working copy)
@@ -535,6 +535,9 @@
 	UIDINFO_UNLOCK(uip);
 
 	knlist_add(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0);
+
+	vp->v_watched++;
+	printf("vp: %p watched: %d\n", vp, vp->v_watched);
 done:
 	NDFREE(&nd, NDF_ONLY_PNBUF);
 	VOP_UNLOCK(vp, 0, curthread);
@@ -547,7 +550,7 @@
 filt_nvnodedetach(struct knote *kn)
 {
 	struct uidinfo *uip;
-	struct vnode *vp;
+	struct vnode *vp, *v;
 
 	vp = (struct vnode *)kn->kn_hook;
 	KASSERT(vp->v_pollinfo != NULL, ("Missing v_pollinfo"));
@@ -556,7 +559,18 @@
 	uip->ui_watchedvnodes--;
 	UIDINFO_UNLOCK(uip);
 	knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0);
-	vrele(vp);
+	/* XXX Should we VFS_LOCK_GIANT here? */
+	if (vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, curthread))
+		panic("Couldn't lock vnode");
+	vp->v_watched--;
+	if (vp->v_watched == 0) {
+		RB_FOREACH(v, vn_rb_tree, &vp->v_subwatched) {
+			printf("%s: removing %p from parent %p\n", __func__, v, vp);
+			RB_REMOVE(vn_rb_tree, &vp->v_subwatched, v);
+		}
+	}
+	printf("vp: %p watched: %d\n", vp, vp->v_watched);
+	vput(vp);
 }
 
 static int
Index: sys/kern/vfs_cache.c
===================================================================
--- sys/kern/vfs_cache.c	(revision 166)
+++ sys/kern/vfs_cache.c	(working copy)
@@ -656,11 +656,21 @@
 		return (error);
 
 	error = cache_lookup(dvp, vpp, cnp);
-	if (error == 0)
-		return (VOP_CACHEDLOOKUP(dvp, vpp, cnp));
+	if (error == 0) {
+		error = VOP_CACHEDLOOKUP(dvp, vpp, cnp);
+		goto done;
+	}
 	if (error == ENOENT)
 		return (error);
-	return (0);
+	error = 0;
+done:
+	/* XXX locking in the DOTDOT case */
+	if (dvp->v_watched && *vpp && dvp != *vpp && !(*vpp)->v_parentdir) {
+		printf("%s: adding %p to parent %p\n", __func__, *vpp, dvp);
+		(*vpp)->v_parentdir = dvp;
+		RB_INSERT(vn_rb_tree, &dvp->v_subwatched, *vpp);
+	}
+	return (error);
 }
 
 
Index: sys/kern/vfs_subr.c
===================================================================
--- sys/kern/vfs_subr.c	(revision 166)
+++ sys/kern/vfs_subr.c	(working copy)
@@ -856,6 +856,9 @@
 	 */
 	LIST_INIT(&vp->v_cache_src);
 	TAILQ_INIT(&vp->v_cache_dst);
+
+	RB_INIT(&vp->v_subwatched);
+
 	/*
 	 * Finalize various vnode identity bits.
 	 */
@@ -2261,6 +2264,13 @@
 	if (vinvalbuf(vp, V_SAVE, td, 0, 0) != 0)
 		vinvalbuf(vp, 0, td, 0, 0);
 
+	/* XXX free the rb tree, if it exists, remove from parent's rb */
+	KASSERT(RB_EMPTY(vn->v_subwatched), ("v_subwatched not empty!"));
+	if (vp->v_parentdir) {
+		printf("removing %p from parent %p\n", vp, vp->v_parentdir);
+		RB_REMOVE(vn_rb_tree, &vp->v_parentdir->v_subwatched, vp);
+	}
+
 	/*
 	 * If purging an active vnode, it must be closed and
 	 * deactivated before being reclaimed.
@@ -3412,9 +3422,16 @@
 vop_create_post(void *ap, int rc)
 {
 	struct vop_create_args *a = ap;
+	struct vnode *vp = *a->a_vpp;
 
-	if (!rc)
+	if (!rc) {
+		if (a->a_dvp->v_watched) {
+			printf("adding parentdir %p to %p (%d)\n", a->a_dvp, vp, a->a_dvp->v_watched);
+			vp->v_parentdir = a->a_dvp;
+			RB_INSERT(vn_rb_tree, &a->a_dvp->v_subwatched, vp);
+		}
 		VFS_SEND_KNOTE(a->a_dvp, NOTE_WRITE);
+	}
 }
 
 void
@@ -3432,18 +3449,30 @@
 vop_mkdir_post(void *ap, int rc)
 {
 	struct vop_mkdir_args *a = ap;
+	struct vnode *vp = *a->a_vpp;
 
-	if (!rc)
+	if (!rc) {
+		if (a->a_dvp->v_watched) {
+			vp->v_parentdir = a->a_dvp;
+			RB_INSERT(vn_rb_tree, &a->a_dvp->v_subwatched, vp);
+		}
 		VFS_SEND_KNOTE(a->a_dvp, NOTE_WRITE | NOTE_LINK);
+	}
 }
 
 void
 vop_mknod_post(void *ap, int rc)
 {
 	struct vop_mknod_args *a = ap;
+	struct vnode *vp = *a->a_vpp;
 
-	if (!rc)
+	if (!rc) {
+		if (a->a_dvp->v_watched) {
+			vp->v_parentdir = a->a_dvp;
+			RB_INSERT(vn_rb_tree, &a->a_dvp->v_subwatched, vp);
+		}
 		VFS_SEND_KNOTE(a->a_dvp, NOTE_WRITE);
+	}
 }
 
 void
@@ -3454,6 +3483,8 @@
 	if (!rc) {
 		VFS_SEND_KNOTE(a->a_dvp, NOTE_WRITE);
 		VFS_SEND_KNOTE(a->a_vp, NOTE_DELETE);
+		RB_REMOVE(vn_rb_tree, &a->a_dvp->v_subwatched, a->a_vp);
+		a->a_vp->v_parentdir = NULL;
 	}
 }
 
@@ -3463,6 +3494,11 @@
 	struct vop_rename_args *a = ap;
 
 	if (!rc) {
+		if (a->a_tdvp->v_watched) {
+			a->a_fvp->v_parentdir = a->a_tdvp;
+			RB_INSERT(vn_rb_tree, &a->a_tdvp->v_subwatched, 
+			    a->a_fvp->v_parentdir);
+		}
 		VFS_SEND_KNOTE(a->a_fdvp, NOTE_WRITE);
 		VFS_SEND_KNOTE(a->a_tdvp, NOTE_WRITE);
 		VFS_SEND_KNOTE(a->a_fvp, NOTE_RENAME);
@@ -3486,9 +3522,17 @@
 vop_setattr_post(void *ap, int rc)
 {
 	struct vop_setattr_args *a = ap;
+	struct vnode *v;
 
-	if (!rc)
+	if (!rc) {
+		if (a->a_vp->v_parentdir) {
+			printf("vp: %p parent: %p children:", a->a_vp, a->a_vp->v_parentdir);
+			RB_FOREACH(v, vn_rb_tree, &a->a_vp->v_parentdir->v_subwatched)
+				printf(" %p", v);
+			printf("\n");
+		}
 		VFS_SEND_KNOTE(a->a_vp, NOTE_ATTRIB);
+	}
 }
 
 void
@@ -3692,3 +3736,16 @@
 	}
 	return (kn->kn_fflags != 0);
 }
+
+static int rb_vn_cmp(struct vnode *v1, struct vnode *v2);
+RB_GENERATE(vn_rb_tree, vnode, v_rbnode, rb_vn_cmp);
+
+static int
+rb_vn_cmp(struct vnode *v1, struct vnode *v2)
+{
+	if (v1 < v2)
+		return (-1);
+	if (v1 > v2)
+		return (1);
+	return (0);
+}
Index: sys/sys/vnode.h
===================================================================
--- sys/sys/vnode.h	(revision 166)
+++ sys/sys/vnode.h	(working copy)
@@ -50,6 +50,8 @@
 #include <sys/acl.h>
 #include <sys/ktr.h>
 
+#include <sys/tree.h>
+
 /*
  * The vnode is the focus of all file activity in UNIX.  There is a
  * unique vnode allocated for each active file, each current directory,
@@ -105,6 +107,10 @@
 
 #if defined(_KERNEL) || defined(_KVM_VNODE)
 
+//struct vn_rb_tree;
+RB_HEAD(vn_rb_tree, vnode);
+RB_PROTOTYPE(vn_rb_tree, vnode, v_rbnode, rb_vn_cmp);
+
 struct vnode {
 	/*
 	 * Fields which define the identity of the vnode.  These fields are
@@ -181,6 +187,12 @@
 	 */
 	struct vpollinfo *v_pollinfo;		/* G Poll events, p for *v_pi */
 	struct label *v_label;			/* MAC label for vnode */
+
+	int v_watched;				/* v */
+	struct vnode *v_parentdir;		/* v */
+	struct vn_rb_tree v_subwatched;		/* v */
+	RB_ENTRY(vnode) v_rbnode;		/* v */
+	
 };
 
 #endif /* defined(_KERNEL) || defined(_KVM_VNODE) */