Index: head/sys/kern/vfs_subr.c
===================================================================
--- head/sys/kern/vfs_subr.c
+++ head/sys/kern/vfs_subr.c
@@ -3018,6 +3018,19 @@
 		VI_UNLOCK(vp);
 }
 
+void
+vholdnz(struct vnode *vp)
+{
+
+	CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
+#ifdef INVARIANTS
+	int old = atomic_fetchadd_int(&vp->v_holdcnt, 1);
+	VNASSERT(old > 0, vp, ("%s: wrong hold count", __func__));
+#else
+	atomic_add_int(&vp->v_holdcnt, 1);
+#endif
+}
+
 /*
  * Drop the hold count of the vnode.  If this is the last reference to
  * the vnode we place it on the free list unless it has been vgone'd
Index: head/sys/sys/vnode.h
===================================================================
--- head/sys/sys/vnode.h
+++ head/sys/sys/vnode.h
@@ -657,6 +657,7 @@
 #define	vhold(vp)	_vhold((vp), 0)
 #define	vholdl(vp)	_vhold((vp), 1)
 void	_vhold(struct vnode *, bool);
+void	vholdnz(struct vnode *);
 void	vinactive(struct vnode *, struct thread *);
 int	vinvalbuf(struct vnode *vp, int save, int slpflag, int slptimeo);
 int	vtruncbuf(struct vnode *vp, off_t length, int blksize);