From owner-svn-src-all@freebsd.org Mon Aug 3 16:35:19 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 3E3379B29CE; Mon, 3 Aug 2015 16:35:19 +0000 (UTC) (envelope-from trasz@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2001:1900:2254:2068::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 2CE389D3; Mon, 3 Aug 2015 16:35:19 +0000 (UTC) (envelope-from trasz@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.70]) by repo.freebsd.org (8.14.9/8.14.9) with ESMTP id t73GZJse096310; Mon, 3 Aug 2015 16:35:19 GMT (envelope-from trasz@FreeBSD.org) Received: (from trasz@localhost) by repo.freebsd.org (8.14.9/8.14.9/Submit) id t73GZJ5J096309; Mon, 3 Aug 2015 16:35:19 GMT (envelope-from trasz@FreeBSD.org) Message-Id: <201508031635.t73GZJ5J096309@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: trasz set sender to trasz@FreeBSD.org using -f From: Edward Tomasz Napierala Date: Mon, 3 Aug 2015 16:35:18 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r286237 - head/sys/geom X-SVN-Group: head 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: Mon, 03 Aug 2015 16:35:19 -0000 Author: trasz Date: Mon Aug 3 16:35:18 2015 New Revision: 286237 URL: https://svnweb.freebsd.org/changeset/base/286237 Log: 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. Discussed with: kib@, mav@ MFC after: 1 month Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D3050 Modified: head/sys/geom/geom_dev.c Modified: head/sys/geom/geom_dev.c ============================================================================== --- head/sys/geom/geom_dev.c Mon Aug 3 16:30:47 2015 (r286236) +++ head/sys/geom/geom_dev.c Mon Aug 3 16:35:18 2015 (r286237) @@ -401,6 +401,20 @@ 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;