Fixes Unionfs socket issue reported as kern/118346.

PR:		118346
Submitted by:	Masanori OZAWA <ozawa@ongs.co.jp>
Discussed at:	devsummit Strassburg, EuroBSDCon2008
Discussed with:	rwatson, gnn, hrs
MFC after:	2 week

sys/fs/unionfs/union.h

@@ -117,6 +117,7 @@ void unionfs_create_uppervattr_core(struct unionfs_mount *ump, struct vattr *lva
 int unionfs_create_uppervattr(struct unionfs_mount *ump, struct vnode *lvp, struct vattr *uva, struct ucred *cred, struct thread *td);
 int unionfs_mkshadowdir(struct unionfs_mount *ump, struct vnode *duvp, struct unionfs_node *unp, struct componentname *cnp, struct thread *td);
 int unionfs_mkwhiteout(struct vnode *dvp, struct componentname *cnp, struct thread *td, char *path);
+int unionfs_relookup(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp, struct componentname *cn, struct thread *td, char *path, int pathlen, u_long nameiop);
 int unionfs_relookup_for_create(struct vnode *dvp, struct componentname *cnp, struct thread *td);
 int unionfs_relookup_for_delete(struct vnode *dvp, struct componentname *cnp, struct thread *td);
 int unionfs_relookup_for_rename(struct vnode *dvp, struct componentname *cnp, struct thread *td);

sys/fs/unionfs/union_subr.c

@@ -113,10 +113,10 @@ unionfs_get_cached_vnode(struct vnode *uvp, struct vnode *lvp,
 	struct unionfs_node *unp;
 	struct vnode   *vp;
 
-	KASSERT((uvp == NULLVP || uvp->v_type == VDIR || uvp->v_type == VSOCK),
+	KASSERT((uvp == NULLVP || uvp->v_type == VDIR),
-	    ("unionfs_get_cached_vnode: v_type != VDIR/VSOCK"));
+	    ("unionfs_get_cached_vnode: v_type != VDIR"));
-	KASSERT((lvp == NULLVP || lvp->v_type == VDIR || lvp->v_type == VSOCK),
+	KASSERT((lvp == NULLVP || lvp->v_type == VDIR),
-	    ("unionfs_get_cached_vnode: v_type != VDIR/VSOCK"));
+	    ("unionfs_get_cached_vnode: v_type != VDIR"));
 
 	VI_LOCK(dvp);
 	hd = unionfs_get_hashhead(dvp, path);
@@ -150,12 +150,10 @@ unionfs_ins_cached_vnode(struct unionfs_node *uncp,
 	struct unionfs_node *unp;
 	struct vnode   *vp;
 
-	KASSERT((uncp->un_uppervp==NULLVP || uncp->un_uppervp->v_type==VDIR ||
+	KASSERT((uncp->un_uppervp==NULLVP || uncp->un_uppervp->v_type==VDIR),
-	    uncp->un_uppervp->v_type==VSOCK),
+	    ("unionfs_ins_cached_vnode: v_type != VDIR"));
-	    ("unionfs_ins_cached_vnode: v_type != VDIR/VSOCK"));
+	KASSERT((uncp->un_lowervp==NULLVP || uncp->un_lowervp->v_type==VDIR),
-	KASSERT((uncp->un_lowervp==NULLVP || uncp->un_lowervp->v_type==VDIR ||
+	    ("unionfs_ins_cached_vnode: v_type != VDIR"));
-	    uncp->un_lowervp->v_type==VSOCK),
-	    ("unionfs_ins_cached_vnode: v_type != VDIR/VSOCK"));
 
 	VI_LOCK(dvp);
 	hd = unionfs_get_hashhead(dvp, path);
@@ -236,7 +234,7 @@ unionfs_nodeget(struct mount *mp, struct vnode *uppervp,
 		path = NULL;
 
 	/* check the cache */
-	if (path != NULL && dvp != NULLVP && (vt == VDIR || vt == VSOCK)) {
+	if (path != NULL && dvp != NULLVP && vt == VDIR) {
 		vp = unionfs_get_cached_vnode(uppervp, lowervp, dvp, path);
 		if (vp != NULLVP) {
 			vref(vp);
@@ -277,20 +275,9 @@ unionfs_nodeget(struct mount *mp, struct vnode *uppervp,
 	if (lowervp != NULLVP)
 		vref(lowervp);
 
-	switch (vt) {
+	if (vt == VDIR)
-	case VDIR:
 		unp->un_hashtbl = hashinit(NUNIONFSNODECACHE, M_UNIONFSHASH,
 		    &(unp->un_hashmask));
-		break;
-	case VSOCK:
-		if (uppervp != NULLVP)
-			vp->v_socket = uppervp->v_socket;
-		else
-			vp->v_socket = lowervp->v_socket;
-		break;
-	default:
-		break;
-	}
 
 	unp->un_vnode = vp;
 	unp->un_uppervp = uppervp;
@@ -314,7 +301,7 @@ unionfs_nodeget(struct mount *mp, struct vnode *uppervp,
 	    (lowervp != NULLVP && ump->um_lowervp == lowervp))
 		vp->v_vflag |= VV_ROOT;
 
-	if (path != NULL && dvp != NULLVP && (vt == VDIR || vt == VSOCK))
+	if (path != NULL && dvp != NULLVP && vt == VDIR)
 		*vpp = unionfs_ins_cached_vnode(unp, dvp, path);
 	if ((*vpp) != NULLVP) {
 		if (dvp != NULLVP)
@@ -540,7 +527,7 @@ unionfs_create_uppervattr(struct unionfs_mount *ump,
  * locked, referenced vnode. If *vpp == dvp then remember that only one
  * LK_EXCLUSIVE lock is held.
  */
-static int
+int
 unionfs_relookup(struct vnode *dvp, struct vnode **vpp,
 		 struct componentname *cnp, struct componentname *cn,
 		 struct thread *td, char *path, int pathlen, u_long nameiop)
@@ -748,8 +735,7 @@ unionfs_node_update(struct unionfs_node *unp, struct vnode *uvp,
 	/*
 	 * cache update
 	 */
-	if (unp->un_path != NULL && dvp != NULLVP &&
+	if (unp->un_path != NULL && dvp != NULLVP && vp->v_type == VDIR) {
-	    (vp->v_type == VDIR || vp->v_type == VSOCK)) {
 		static struct unionfs_node_hashhead *hd;
 
 		VI_LOCK(dvp);

sys/fs/unionfs/union_vnops.c

@@ -71,6 +71,10 @@
 #define UNIONFS_INTERNAL_DEBUG(msg, args...)
 #endif
 
+#define KASSERT_UNIONFS_VNODE(vp) \
+	KASSERT(((vp)->v_op == &unionfs_vnodeops), \
+	    ("unionfs: it is not unionfs-vnode"))
+
 /* lockmgr lock <-> reverse table */
 struct lk_lr_table {
 	int	lock;
@@ -307,8 +311,27 @@ unionfs_lookup(struct vop_cachedlookup_args *ap)
 			error = lerror;
 		if (error != 0)
 			goto unionfs_lookup_out;
-		error = unionfs_nodeget(dvp->v_mount, uvp, lvp, dvp, &vp,
+		/*
-		    cnp, td);
+		 * get socket vnode.
+		 */
+		if (uvp != NULLVP && uvp->v_type == VSOCK) {
+			vp = uvp;
+			vref(vp);
+			if (cnp->cn_lkflags & LK_TYPE_MASK)
+				vn_lock(vp, cnp->cn_lkflags | LK_RETRY);
+		}
+		else if (lvp != NULLVP && lvp->v_type == VSOCK) {
+			vp = lvp;
+			vref(vp);
+			if (cnp->cn_lkflags & LK_TYPE_MASK)
+				vn_lock(vp, cnp->cn_lkflags | LK_RETRY);
+		}
+		/*
+		 * get unionfs vnode.
+		 */
+		else
+			error = unionfs_nodeget(dvp->v_mount, uvp, lvp,
+			    dvp, &vp, cnp, td);
 		if (error != 0) {
 			UNIONFSDEBUG("unionfs_lookup: Unable to create unionfs vnode.");
 			goto unionfs_lookup_out;
@@ -320,7 +343,7 @@ unionfs_lookup(struct vop_cachedlookup_args *ap)
 
 	*(ap->a_vpp) = vp;
 
-	if (cnflags & MAKEENTRY)
+	if ((cnflags & MAKEENTRY) && vp->v_type != VSOCK)
 		cache_enter(dvp, vp, cnp);
 
 unionfs_lookup_out:
@@ -348,13 +371,21 @@ unionfs_create(struct vop_create_args *ap)
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_create: enter\n");
 
+	KASSERT_UNIONFS_VNODE(ap->a_dvp);
+
 	dunp = VTOUNIONFS(ap->a_dvp);
 	cnp = ap->a_cnp;
 	udvp = dunp->un_uppervp;
 	error = EROFS;
 
 	if (udvp != NULLVP) {
-		if ((error = VOP_CREATE(udvp, &vp, cnp, ap->a_vap)) == 0) {
+		error = VOP_CREATE(udvp, &vp, cnp, ap->a_vap);
+		if (error != 0)
+			goto unionfs_create_abort;
+
+		if (vp->v_type == VSOCK)
+			*(ap->a_vpp) = vp;
+		else {
 			VOP_UNLOCK(vp, 0);
 			error = unionfs_nodeget(ap->a_dvp->v_mount, vp, NULLVP,
 			    ap->a_dvp, ap->a_vpp, cnp, curthread);
@@ -362,6 +393,7 @@ unionfs_create(struct vop_create_args *ap)
 		}
 	}
 
+unionfs_create_abort:
 	UNIONFS_INTERNAL_DEBUG("unionfs_create: leave (%d)\n", error);
 
 	return (error);
@@ -377,6 +409,8 @@ unionfs_whiteout(struct vop_whiteout_args *ap)
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_whiteout: enter\n");
 
+	KASSERT_UNIONFS_VNODE(ap->a_dvp);
+
 	dunp = VTOUNIONFS(ap->a_dvp);
 	cnp = ap->a_cnp;
 	udvp = dunp->un_uppervp;
@@ -411,13 +445,21 @@ unionfs_mknod(struct vop_mknod_args *ap)
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_mknod: enter\n");
 
+	KASSERT_UNIONFS_VNODE(ap->a_dvp);
+
 	dunp = VTOUNIONFS(ap->a_dvp);
 	cnp = ap->a_cnp;
 	udvp = dunp->un_uppervp;
 	error = EROFS;
 
 	if (udvp != NULLVP) {
-		if ((error = VOP_MKNOD(udvp, &vp, cnp, ap->a_vap)) == 0) {
+		error = VOP_MKNOD(udvp, &vp, cnp, ap->a_vap);
+		if (error != 0)
+			goto unionfs_mknod_abort;
+
+		if (vp->v_type == VSOCK)
+			*(ap->a_vpp) = vp;
+		else {
 			VOP_UNLOCK(vp, 0);
 			error = unionfs_nodeget(ap->a_dvp->v_mount, vp, NULLVP,
 			    ap->a_dvp, ap->a_vpp, cnp, curthread);
@@ -425,6 +467,7 @@ unionfs_mknod(struct vop_mknod_args *ap)
 		}
 	}
 
+unionfs_mknod_abort:
 	UNIONFS_INTERNAL_DEBUG("unionfs_mknod: leave (%d)\n", error);
 
 	return (error);
@@ -444,6 +487,8 @@ unionfs_open(struct vop_open_args *ap)
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_open: enter\n");
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	error = 0;
 	unp = VTOUNIONFS(ap->a_vp);
 	uvp = unp->un_uppervp;
@@ -523,6 +568,8 @@ unionfs_close(struct vop_close_args *ap)
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_close: enter\n");
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	locked = 0;
 	unp = VTOUNIONFS(ap->a_vp);
 	cred = ap->a_cred;
@@ -650,6 +697,8 @@ unionfs_access(struct vop_access_args *ap)
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_access: enter\n");
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
 	unp = VTOUNIONFS(ap->a_vp);
 	uvp = unp->un_uppervp;
@@ -727,6 +776,8 @@ unionfs_getattr(struct vop_getattr_args *ap)
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_getattr: enter\n");
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	unp = VTOUNIONFS(ap->a_vp);
 	ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
 	uvp = unp->un_uppervp;
@@ -777,6 +828,8 @@ unionfs_setattr(struct vop_setattr_args *ap)
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_setattr: enter\n");
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	error = EROFS;
 	unp = VTOUNIONFS(ap->a_vp);
 	uvp = unp->un_uppervp;
@@ -815,6 +868,8 @@ unionfs_read(struct vop_read_args *ap)
 
 	/* UNIONFS_INTERNAL_DEBUG("unionfs_read: enter\n"); */
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	unp = VTOUNIONFS(ap->a_vp);
 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
 
@@ -834,6 +889,8 @@ unionfs_write(struct vop_write_args *ap)
 
 	/* UNIONFS_INTERNAL_DEBUG("unionfs_write: enter\n"); */
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	unp = VTOUNIONFS(ap->a_vp);
 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
 
@@ -853,6 +910,8 @@ unionfs_lease(struct vop_lease_args *ap)
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_lease: enter\n");
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	unp = VTOUNIONFS(ap->a_vp);
 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
 
@@ -873,6 +932,8 @@ unionfs_ioctl(struct vop_ioctl_args *ap)
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_ioctl: enter\n");
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
  	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
 	unp = VTOUNIONFS(ap->a_vp);
 	unionfs_get_node_status(unp, ap->a_td, &unsp);
@@ -898,6 +959,8 @@ unionfs_poll(struct vop_poll_args *ap)
 	struct unionfs_node_status *unsp;
 	struct vnode   *ovp;
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
  	vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
 	unp = VTOUNIONFS(ap->a_vp);
 	unionfs_get_node_status(unp, ap->a_td, &unsp);
@@ -918,6 +981,8 @@ unionfs_fsync(struct vop_fsync_args *ap)
 	struct unionfs_node_status *unsp;
 	struct vnode   *ovp;
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	unp = VTOUNIONFS(ap->a_vp);
 	unionfs_get_node_status(unp, ap->a_td, &unsp);
 	ovp = (unsp->uns_upper_opencnt ? unp->un_uppervp : unp->un_lowervp);
@@ -933,36 +998,81 @@ static int
 unionfs_remove(struct vop_remove_args *ap)
 {
 	int		error;
+	char	       *path;
 	struct unionfs_node *dunp;
 	struct unionfs_node *unp;
 	struct unionfs_mount *ump;
 	struct vnode   *udvp;
 	struct vnode   *uvp;
 	struct vnode   *lvp;
+	struct vnode   *vp;
 	struct componentname *cnp;
+	struct componentname cn;
 	struct thread  *td;
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_remove: enter\n");
 
+	KASSERT_UNIONFS_VNODE(ap->a_dvp);
+
 	error = 0;
 	dunp = VTOUNIONFS(ap->a_dvp);
-	unp = VTOUNIONFS(ap->a_vp);
 	udvp = dunp->un_uppervp;
-	uvp = unp->un_uppervp;
-	lvp = unp->un_lowervp;
 	cnp = ap->a_cnp;
 	td = curthread;
 
+	if (ap->a_vp->v_op != &unionfs_vnodeops) {
+		if (ap->a_vp->v_type != VSOCK)
+			return (EINVAL);
+		ump = NULL;
+		vp = uvp = lvp = NULLVP;
+		/* search vnode */
+		VOP_UNLOCK(ap->a_vp, 0);
+		error = unionfs_relookup(udvp, &vp, cnp, &cn, td,
+		    cnp->cn_nameptr, strlen(cnp->cn_nameptr), DELETE);
+		if (error != 0 && error != ENOENT) {
+			vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
+			return (error);
+		}
+
+		if (error == 0 && vp == ap->a_vp) {
+			/* target vnode in upper */
+			uvp = vp;
+			vrele(vp);
+			path = NULL;
+		} else {
+			/* target vnode in lower */
+			if (vp != NULLVP) {
+				if (udvp == vp)
+					vrele(vp);
+				else
+					vput(vp);
+			}
+			vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY);
+			lvp = ap->a_vp;
+			path = ap->a_cnp->cn_nameptr;
+		}
+	} else {
+		ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
+		unp = VTOUNIONFS(ap->a_vp);
+		uvp = unp->un_uppervp;
+		lvp = unp->un_lowervp;
+		path = unp->un_path;
+	}
+
 	if (udvp == NULLVP)
 		return (EROFS);
 
 	if (uvp != NULLVP) {
-		ump = MOUNTTOUNIONFSMOUNT(ap->a_vp->v_mount);
+		/*
-		if (ump->um_whitemode == UNIONFS_WHITE_ALWAYS || lvp != NULLVP)
+		 * XXX: if the vnode type is VSOCK, it will create whiteout
+		 *      after remove.
+		 */
+		if (ump == NULL || ump->um_whitemode == UNIONFS_WHITE_ALWAYS ||
+		    lvp != NULLVP)
 			cnp->cn_flags |= DOWHITEOUT;
 		error = VOP_REMOVE(udvp, uvp, cnp);
 	} else if (lvp != NULLVP)
-		error = unionfs_mkwhiteout(udvp, cnp, td, unp->un_path);
+		error = unionfs_mkwhiteout(udvp, cnp, td, path);
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_remove: leave (%d)\n", error);
 
@@ -983,6 +1093,9 @@ unionfs_link(struct vop_link_args *ap)
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_link: enter\n");
 
+	KASSERT_UNIONFS_VNODE(ap->a_tdvp);
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	error = 0;
 	needrelookup = 0;
 	dunp = VTOUNIONFS(ap->a_tdvp);
@@ -1073,7 +1186,10 @@ unionfs_rename(struct vop_rename_args *ap)
 	/* check for cross device rename */
 	if (fvp->v_mount != tdvp->v_mount ||
 	    (tvp != NULLVP && fvp->v_mount != tvp->v_mount)) {
-		error = EXDEV;
+		if (fvp->v_op != &unionfs_vnodeops)
+			error = ENODEV;
+		else
+			error = EXDEV;
 		goto unionfs_rename_abort;
 	}
 
@@ -1085,6 +1201,12 @@ unionfs_rename(struct vop_rename_args *ap)
 	 * from/to vnode is unionfs node.
 	 */
 
+	KASSERT_UNIONFS_VNODE(fdvp);
+	KASSERT_UNIONFS_VNODE(fvp);
+	KASSERT_UNIONFS_VNODE(tdvp);
+	if (tvp != NULLVP)
+		KASSERT_UNIONFS_VNODE(tvp);
+
 	unp = VTOUNIONFS(fdvp);
 #ifdef UNIONFS_IDBG_RENAME
 	UNIONFS_INTERNAL_DEBUG("fdvp=%p, ufdvp=%p, lfdvp=%p\n", fdvp, unp->un_uppervp, unp->un_lowervp);
@@ -1254,6 +1376,8 @@ unionfs_mkdir(struct vop_mkdir_args *ap)
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_mkdir: enter\n");
 
+	KASSERT_UNIONFS_VNODE(ap->a_dvp);
+
 	error = EROFS;
 	dunp = VTOUNIONFS(ap->a_dvp);
 	cnp = ap->a_cnp;
@@ -1301,6 +1425,9 @@ unionfs_rmdir(struct vop_rmdir_args *ap)
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_rmdir: enter\n");
 
+	KASSERT_UNIONFS_VNODE(ap->a_dvp);
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	error = 0;
 	dunp = VTOUNIONFS(ap->a_dvp);
 	unp = VTOUNIONFS(ap->a_vp);
@@ -1353,6 +1480,8 @@ unionfs_symlink(struct vop_symlink_args *ap)
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_symlink: enter\n");
 
+	KASSERT_UNIONFS_VNODE(ap->a_dvp);
+
 	error = EROFS;
 	dunp = VTOUNIONFS(ap->a_dvp);
 	cnp = ap->a_cnp;
@@ -1396,6 +1525,8 @@ unionfs_readdir(struct vop_readdir_args *ap)
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_readdir: enter\n");
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	error = 0;
 	eofflag = 0;
 	locked = 0;
@@ -1543,6 +1674,8 @@ unionfs_readlink(struct vop_readlink_args *ap)
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_readlink: enter\n");
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	unp = VTOUNIONFS(ap->a_vp);
 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
 
@@ -1568,6 +1701,8 @@ unionfs_getwritemount(struct vop_getwritemount_args *ap)
 	if (vp == NULLVP || (vp->v_mount->mnt_flag & MNT_RDONLY))
 		return (EACCES);
 
+	KASSERT_UNIONFS_VNODE(vp);
+
 	uvp = UNIONFSVPTOUPPERVP(vp);
 	if (uvp == NULLVP && VREG == vp->v_type)
 		uvp = UNIONFSVPTOUPPERVP(VTOUNIONFS(vp)->un_dvp);
@@ -1661,6 +1796,8 @@ unionfs_lock(struct vop_lock1_args *ap)
 	struct vnode   *uvp;
 	struct vnode   *lvp;
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	error = 0;
 	uhold = 0;
 	flags = ap->a_flags;
@@ -1781,6 +1918,8 @@ unionfs_unlock(struct vop_unlock_args *ap)
 	struct vnode   *uvp;
 	struct unionfs_node *unp;
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	error = 0;
 	mtxlkflag = 0;
 	uhold = 0;
@@ -1849,6 +1988,8 @@ unionfs_pathconf(struct vop_pathconf_args *ap)
 	struct unionfs_node *unp;
 	struct vnode   *vp;
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	unp = VTOUNIONFS(ap->a_vp);
 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
 
@@ -1867,6 +2008,8 @@ unionfs_advlock(struct vop_advlock_args *ap)
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_advlock: enter\n");
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	vp = ap->a_vp;
 	td = curthread;
 
@@ -1917,6 +2060,8 @@ unionfs_strategy(struct vop_strategy_args *ap)
 	struct unionfs_node *unp;
 	struct vnode   *vp;
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	unp = VTOUNIONFS(ap->a_vp);
 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
 
@@ -1938,6 +2083,8 @@ unionfs_getacl(struct vop_getacl_args *ap)
 	struct unionfs_node *unp;
 	struct vnode   *vp;
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	unp = VTOUNIONFS(ap->a_vp);
 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
 
@@ -1961,6 +2108,8 @@ unionfs_setacl(struct vop_setacl_args *ap)
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_setacl: enter\n");
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	error = EROFS;
 	unp = VTOUNIONFS(ap->a_vp);
 	uvp = unp->un_uppervp;
@@ -1993,6 +2142,8 @@ unionfs_aclcheck(struct vop_aclcheck_args *ap)
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_aclcheck: enter\n");
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	unp = VTOUNIONFS(ap->a_vp);
 	vp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
 
@@ -2011,6 +2162,8 @@ unionfs_openextattr(struct vop_openextattr_args *ap)
 	struct vnode   *vp;
 	struct vnode   *tvp;
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	vp = ap->a_vp;
 	unp = VTOUNIONFS(vp);
 	tvp = (unp->un_uppervp != NULLVP ? unp->un_uppervp : unp->un_lowervp);
@@ -2041,6 +2194,8 @@ unionfs_closeextattr(struct vop_closeextattr_args *ap)
 	struct vnode   *vp;
 	struct vnode   *tvp;
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	vp = ap->a_vp;
 	unp = VTOUNIONFS(vp);
 	tvp = NULLVP;
@@ -2073,6 +2228,8 @@ unionfs_getextattr(struct vop_getextattr_args *ap)
 	struct unionfs_node *unp;
 	struct vnode   *vp;
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	unp = VTOUNIONFS(ap->a_vp);
 	vp = NULLVP;
 
@@ -2099,6 +2256,8 @@ unionfs_setextattr(struct vop_setextattr_args *ap)
 	struct ucred   *cred;
 	struct thread  *td;
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	error = EROFS;
 	unp = VTOUNIONFS(ap->a_vp);
 	uvp = unp->un_uppervp;
@@ -2158,6 +2317,8 @@ unionfs_listextattr(struct vop_listextattr_args *ap)
 	struct unionfs_node *unp;
 	struct vnode   *vp;
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	unp = VTOUNIONFS(ap->a_vp);
 	vp = NULLVP;
 
@@ -2184,6 +2345,8 @@ unionfs_deleteextattr(struct vop_deleteextattr_args *ap)
 	struct ucred   *cred;
 	struct thread  *td;
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	error = EROFS;
 	unp = VTOUNIONFS(ap->a_vp);
 	uvp = unp->un_uppervp;
@@ -2248,6 +2411,8 @@ unionfs_setlabel(struct vop_setlabel_args *ap)
 
 	UNIONFS_INTERNAL_DEBUG("unionfs_setlabel: enter\n");
 
+	KASSERT_UNIONFS_VNODE(ap->a_vp);
+
 	error = EROFS;
 	unp = VTOUNIONFS(ap->a_vp);
 	uvp = unp->un_uppervp;