From owner-svn-src-all@freebsd.org Sun Oct 18 14:34:15 2015 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 1A343A18563; Sun, 18 Oct 2015 14:34:15 +0000 (UTC) (envelope-from trasz@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id D40A5FF2; Sun, 18 Oct 2015 14:34:14 +0000 (UTC) (envelope-from trasz@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id t9IEYDng093388; Sun, 18 Oct 2015 14:34:13 GMT (envelope-from trasz@FreeBSD.org) Received: (from trasz@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id t9IEYDvd093387; Sun, 18 Oct 2015 14:34:13 GMT (envelope-from trasz@FreeBSD.org) Message-Id: <201510181434.t9IEYDvd093387@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: trasz set sender to trasz@FreeBSD.org using -f From: Edward Tomasz Napierala Date: Sun, 18 Oct 2015 14:34:13 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r289511 - stable/10/sys/geom X-SVN-Group: stable-10 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 18 Oct 2015 14:34:15 -0000 Author: trasz Date: Sun Oct 18 14:34:13 2015 New Revision: 289511 URL: https://svnweb.freebsd.org/changeset/base/289511 Log: MFC r286237: Fix panic that would happen on forcibly unmounting devfs (note that as it is now, devfs ignores MNT_FORCE anyway, so it needs to be modified to trigger the panic) with consumers still opened. Note that this still results in a leak of r/w/e counters. It seems to be harmless, though. If anyone knows a better way to approach this - please tell. Sponsored by: The FreeBSD Foundation Modified: stable/10/sys/geom/geom_dev.c Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/geom/geom_dev.c ============================================================================== --- stable/10/sys/geom/geom_dev.c Sun Oct 18 14:31:54 2015 (r289510) +++ stable/10/sys/geom/geom_dev.c Sun Oct 18 14:34:13 2015 (r289511) @@ -399,6 +399,20 @@ g_dev_close(struct cdev *dev, int flags, #else e = 0; #endif + + /* + * The vgonel(9) - caused by eg. forced unmount of devfs - calls + * VOP_CLOSE(9) on devfs vnode without any FREAD or FWRITE flags, + * which would result in zero deltas, which in turn would cause + * panic in g_access(9). + * + * Note that we cannot zero the counters (ie. do "r = cp->acr" + * etc) instead, because the consumer might be opened in another + * devfs instance. + */ + if (r + w + e == 0) + return (EINVAL); + sc = cp->private; mtx_lock(&sc->sc_mtx); sc->sc_open += r + w + e;