--- src/sys/kern/subr_diskslice.c	2007/06/19 06:07:57	1.48
+++ src/sys/kern/subr_diskslice.c	2007/07/23 19:53:34	1.49
@@ -914,7 +914,6 @@ dsopen(cdev_t dev, int mode, u_int flags
 			return (EINVAL);
 		}
 	}
-	dssetmask(sp, part);
 
 	/*
 	 * Do not allow special raw-extension partitions to be opened
@@ -926,6 +925,11 @@ dsopen(cdev_t dev, int mode, u_int flags
 		if ((info->d_dsflags & DSO_RAWEXTENSIONS) == 0)
 			return (EINVAL);
 	}
+
+	/*
+	 * Ok, we are open
+	 */
+	dssetmask(sp, part);
 	return (0);
 }