diff --git a/sys/fs/nullfs/null.h b/sys/fs/nullfs/null.h
--- a/sys/fs/nullfs/null.h
+++ b/sys/fs/nullfs/null.h
@@ -64,6 +64,7 @@
 
 #define	MOUNTTONULLMOUNT(mp) ((struct null_mount *)((mp)->mnt_data))
 #define	VTONULL(vp) ((struct null_node *)(vp)->v_data)
+#define	VTONULL_SMR(vp) ((struct null_node *)vn_load_v_data_smr(vp))
 #define	NULLTOV(xp) ((xp)->null_vnode)
 
 int nullfs_init(struct vfsconf *vfsp);
diff --git a/sys/fs/nullfs/null_vnops.c b/sys/fs/nullfs/null_vnops.c
--- a/sys/fs/nullfs/null_vnops.c
+++ b/sys/fs/nullfs/null_vnops.c
@@ -177,6 +177,8 @@
 #include <sys/sysctl.h>
 #include <sys/vnode.h>
 #include <sys/stat.h>
+#include <sys/proc.h>
+#include <sys/smr.h>
 
 #include <fs/nullfs/null.h>
 
@@ -185,10 +187,17 @@
 #include <vm/vm_object.h>
 #include <vm/vnode_pager.h>
 
+VFS_SMR_DECLARE;
+
 static int null_bug_bypass = 0;   /* for debugging: enables bypass printf'ing */
 SYSCTL_INT(_debug, OID_AUTO, nullfs_bug_bypass, CTLFLAG_RW, 
 	&null_bug_bypass, 0, "");
 
+static bool null_smr_lock = true;
+SYSCTL_BOOL(_debug, OID_AUTO, nullfs_smr_lock, CTLFLAG_RW,
+	&null_smr_lock, 0, "");
+
+
 /*
  * Synchronize inotify flags with the lower vnode:
  * - If the upper vnode has the flag set and the lower does not, then the lower
@@ -772,6 +781,43 @@
  * interlock flag as it applies only to our vnode, not the
  * vnodes below us on the stack.
  */
+static int
+null_lock_smr(struct vnode *vp, int flags)
+{
+	struct null_node *nn;
+	struct vnode *lvp;
+	int error;
+
+	if (!atomic_load_bool(&null_smr_lock))
+		return (EAGAIN);
+
+	vfs_smr_enter();
+
+	nn = VTONULL_SMR(vp);
+	if (__predict_false(nn == NULL))
+		goto out_bad;
+
+	lvp = nn->null_lowervp;
+	if (__predict_false(lvp == NULL))
+		goto out_bad;
+
+	if (__predict_false(!vhold_smr(lvp)))
+		goto out_bad;
+
+	vfs_smr_exit();
+
+	error = VOP_LOCK(lvp, flags);
+	if (VTONULL(vp) == NULL && error == 0) {
+		VOP_UNLOCK(lvp);
+		error = EAGAIN;
+	}
+	vdrop(lvp);
+	return (error);
+out_bad:
+	vfs_smr_exit();
+	return (EAGAIN);
+}
+
 static int
 null_lock(struct vop_lock1_args *ap)
 {
@@ -781,10 +827,14 @@
 	struct vnode *lvp;
 	int error;
 
-	if ((ap->a_flags & LK_INTERLOCK) == 0)
+	if ((ap->a_flags & LK_INTERLOCK) == 0) {
+		error = null_lock_smr(vp, ap->a_flags);
+		if (error == 0)
+			return (error);
 		VI_LOCK(vp);
-	else
+	} else {
 		ap->a_flags &= ~LK_INTERLOCK;
+	}
 	flags = ap->a_flags;
 	nn = VTONULL(vp);
 	/*