Index: sys/kern/vfs_subr.c
===================================================================
--- sys/kern/vfs_subr.c
+++ sys/kern/vfs_subr.c
@@ -339,6 +339,56 @@
 SYSCTL_INT(_debug, OID_AUTO, vnlru_nowhere, CTLFLAG_RW,
     &vnlru_nowhere, 0, "Number of times the vnlru process ran without success");
 
+#ifdef INVARIANTS
+static int
+sysctl_try_reclaim_vnode(SYSCTL_HANDLER_ARGS)
+{
+	struct vnode *vp;
+	struct nameidata nd;
+	char *buf;
+	unsigned long ndflags;
+	int error;
+
+	if (req->newptr == NULL)
+		return (EINVAL);
+
+	if (req->newlen > PATH_MAX)
+		return (E2BIG);
+
+	buf = malloc(PATH_MAX + 1, M_TEMP, M_WAITOK);
+	error = SYSCTL_IN(req, buf, req->newlen);
+	if (error != 0)
+		goto out;
+
+	buf[req->newlen] = '\0';
+
+	ndflags = LOCKLEAF| NOFOLLOW | AUDITVNODE1 | NOCACHE | SAVENAME;
+	NDINIT(&nd, LOOKUP, ndflags, UIO_SYSSPACE, buf, curthread);
+	if ((error = namei(&nd)) != 0)
+		goto out;
+	vp = nd.ni_vp;
+
+	if ((vp->v_iflag & VI_DOOMED) != 0) {
+		error = EBUSY;
+		goto putvnode;
+	}
+
+	vhold(vp);
+	counter_u64_add(recycles_count, 1);
+	vgone(vp);
+	vdrop(vp);
+putvnode:
+	NDFREE(&nd, 0);
+out:
+	free(buf, M_TEMP);
+	return (error);
+}
+
+SYSCTL_PROC(_debug, OID_AUTO, try_reclaim_vnode,
+    CTLTYPE_STRING | CTLFLAG_MPSAFE | CTLFLAG_WR, NULL, 0,
+    sysctl_try_reclaim_vnode, "A", "Try to reclaim a vnode by its pathname");
+#endif /* INVARIANTS */
+
 /* Shift count for (uintptr_t)vp to initialize vp->v_hash. */
 static int vnsz2log;