--- src/sys/vfs/msdosfs/msdosfs_vfsops.c	2007/05/06 19:23:34	1.44
+++ src/sys/vfs/msdosfs/msdosfs_vfsops.c	2007/05/09 00:53:35	1.45
@@ -318,7 +318,7 @@ mountmsdosfs(struct vnode *devvp, struct
 	error = vfs_mountedon(devvp);
 	if (error)
 		return (error);
-	if (count_udev(devvp->v_udev) > 0)
+	if (count_udev(devvp->v_umajor, devvp->v_uminor) > 0)
 		return (EBUSY);
 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
 	error = vinvalbuf(devvp, V_SAVE, 0, 0);