From owner-svn-src-head@FreeBSD.ORG  Fri Mar 23 07:26:18 2012
Return-Path: <owner-svn-src-head@FreeBSD.ORG>
Delivered-To: svn-src-head@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
	by hub.freebsd.org (Postfix) with ESMTP id 1654B1065670;
	Fri, 23 Mar 2012 07:26:18 +0000 (UTC) (envelope-from ae@FreeBSD.org)
Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:4f8:fff6::2c])
	by mx1.freebsd.org (Postfix) with ESMTP id 017E58FC1B;
	Fri, 23 Mar 2012 07:26:18 +0000 (UTC)
Received: from svn.freebsd.org (localhost [127.0.0.1])
	by svn.freebsd.org (8.14.4/8.14.4) with ESMTP id q2N7QHLf062583;
	Fri, 23 Mar 2012 07:26:17 GMT (envelope-from ae@svn.freebsd.org)
Received: (from ae@localhost)
	by svn.freebsd.org (8.14.4/8.14.4/Submit) id q2N7QH06062581;
	Fri, 23 Mar 2012 07:26:17 GMT (envelope-from ae@svn.freebsd.org)
Message-Id: <201203230726.q2N7QH06062581@svn.freebsd.org>
From: "Andrey V. Elsukov" <ae@FreeBSD.org>
Date: Fri, 23 Mar 2012 07:26:17 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
	svn-src-head@freebsd.org
X-SVN-Group: head
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Cc: 
Subject: svn commit: r233342 - head/sys/geom/part
X-BeenThere: svn-src-head@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: SVN commit messages for the src tree for head/-current
	<svn-src-head.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-head>,
	<mailto:svn-src-head-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-head>
List-Post: <mailto:svn-src-head@freebsd.org>
List-Help: <mailto:svn-src-head-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-head>,
	<mailto:svn-src-head-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 23 Mar 2012 07:26:18 -0000

Author: ae
Date: Fri Mar 23 07:26:17 2012
New Revision: 233342
URL: http://svn.freebsd.org/changeset/base/233342

Log:
  Check that scheme is not already registered. This may happens when a
  KLD is preloaded with loader(8) and leads to infinity loops.
  
  Also do not return EEXIST error code from MOD_LOAD handler, because
  we have undocumented(?) ability replace kernel's module with preloaded one.
  And if we have so, then preloaded module will be initialized first.
  Thus error in MOD_LOAD handler will be triggered for the kernel.
  
  PR:		kern/165573
  MFC after:	3 weeks

Modified:
  head/sys/geom/part/g_part.c

Modified: head/sys/geom/part/g_part.c
==============================================================================
--- head/sys/geom/part/g_part.c	Fri Mar 23 06:57:04 2012	(r233341)
+++ head/sys/geom/part/g_part.c	Fri Mar 23 07:26:17 2012	(r233342)
@@ -2211,23 +2211,32 @@ g_part_unload_event(void *arg, int flag)
 int
 g_part_modevent(module_t mod, int type, struct g_part_scheme *scheme)
 {
+	struct g_part_scheme *iter;
 	uintptr_t arg;
 	int error;
 
+	error = 0;
 	switch (type) {
 	case MOD_LOAD:
-		TAILQ_INSERT_TAIL(&g_part_schemes, scheme, scheme_list);
-
-		error = g_retaste(&g_part_class);
-		if (error)
-			TAILQ_REMOVE(&g_part_schemes, scheme, scheme_list);
+		TAILQ_FOREACH(iter, &g_part_schemes, scheme_list) {
+			if (scheme == iter) {
+				printf("GEOM_PART: scheme %s is already "
+				    "registered!\n", scheme->name);
+				break;
+			}
+		}
+		if (iter == NULL) {
+			TAILQ_INSERT_TAIL(&g_part_schemes, scheme,
+			    scheme_list);
+			g_retaste(&g_part_class);
+		}
 		break;
 	case MOD_UNLOAD:
 		arg = (uintptr_t)scheme;
 		error = g_waitfor_event(g_part_unload_event, &arg, M_WAITOK,
 		    NULL);
-		if (!error)
-			error = (arg == (uintptr_t)scheme) ? EDOOFUS : arg;
+		if (error == 0)
+			error = arg;
 		break;
 	default:
 		error = EOPNOTSUPP;