- Skip providers with 0 sectorsize.
- Make kern.geom.concat.debug sysctl tunable.

--- concat/g_concat.c	Mon Aug  9 13:29:42 2004
+++ sys/geom/concat/g_concat.c	Mon Aug 30 20:50:05 2004
@@ -25,7 +25,7 @@
  */
 
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: src/sys/geom/concat/g_concat.c,v 1.18 2004/08/09 11:29:42 pjd Exp $");
+__FBSDID("$FreeBSD: src/sys/geom/concat/g_concat.c,v 1.20 2004/08/30 18:50:05 pjd Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -45,6 +45,7 @@
 SYSCTL_DECL(_kern_geom);
 SYSCTL_NODE(_kern_geom, OID_AUTO, concat, CTLFLAG_RW, 0, "GEOM_CONCAT stuff");
 static u_int g_concat_debug = 0;
+TUNABLE_INT("kern.geom.concat.debug", &g_concat_debug);
 SYSCTL_UINT(_kern_geom_concat, OID_AUTO, debug, CTLFLAG_RW, &g_concat_debug, 0,
     "Debug level");
 
@@ -545,6 +546,9 @@
 	g_topology_assert();
 
 	G_CONCAT_DEBUG(3, "Tasting %s.", pp->name);
+	/* Skip providers with 0 sectorsize. */
+	if (pp->sectorsize == 0)
+		return (NULL);
 
 	gp = g_new_geomf(mp, "concat:taste");
 	gp->start = g_concat_start;