--- vfs_mount.c.orig	Sun Nov 16 15:46:56 2003
+++ vfs_mount.c	Sun Nov 16 15:21:48 2003
@@ -1061,6 +1061,7 @@ update:
 			vfs_unbusy(mp, td);
 		else {
 			mp->mnt_vfc->vfc_refcount--;
+			mtx_destroy(&mp->mnt_mtx);
 			vfs_unbusy(mp, td);
 #ifdef MAC
 			mac_destroy_mount(mp);
@@ -1142,6 +1143,7 @@ update:
 		vp->v_iflag &= ~VI_MOUNT;
 		VI_UNLOCK(vp);
 		mp->mnt_vfc->vfc_refcount--;
+		mtx_destroy(&mp->mnt_mtx);
 		vfs_unbusy(mp, td);
 #ifdef MAC
 		mac_destroy_mount(mp);