From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934416Ab0HXXr3 (ORCPT ); Tue, 24 Aug 2010 19:47:29 -0400 Received: from kroah.org ([198.145.64.141]:52075 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756386Ab0HXWxg (ORCPT ); Tue, 24 Aug 2010 18:53:36 -0400 X-Mailbox-Line: From gregkh@clark.site Tue Aug 24 15:25:23 2010 Message-Id: <20100824222523.445519169@clark.site> User-Agent: quilt/0.48-11.2 Date: Tue, 24 Aug 2010 15:24:24 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Wengang Wang , Joel Becker Subject: [12/59] ocfs2/dlm: remove potential deadlock -V3 In-Reply-To: <20100824224625.GA5449@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-stable review patch. If anyone has any objections, please let us know. ------------------ From: Wengang Wang commit b11f1f1ab73fd358b1b734a9427744802202ba68 upstream. When we need to take both dlm_domain_lock and dlm->spinlock, we should take them in order of: dlm_domain_lock then dlm->spinlock. There is pathes disobey this order. That is calling dlm_lockres_put() with dlm->spinlock held in dlm_run_purge_list. dlm_lockres_put() calls dlm_put() at the ref and dlm_put() locks on dlm_domain_lock. Fix: Don't grab/put the dlm when the initialising/releasing lockres. That grab is not required because we don't call dlm_unregister_domain() based on refcount. Signed-off-by: Wengang Wang Signed-off-by: Joel Becker Signed-off-by: Greg Kroah-Hartman --- fs/ocfs2/dlm/dlmmaster.c | 4 ---- 1 file changed, 4 deletions(-) --- a/fs/ocfs2/dlm/dlmmaster.c +++ b/fs/ocfs2/dlm/dlmmaster.c @@ -511,8 +511,6 @@ static void dlm_lockres_release(struct k atomic_dec(&dlm->res_cur_count); - dlm_put(dlm); - if (!hlist_unhashed(&res->hash_node) || !list_empty(&res->granted) || !list_empty(&res->converting) || @@ -585,8 +583,6 @@ static void dlm_init_lockres(struct dlm_ res->migration_pending = 0; res->inflight_locks = 0; - /* put in dlm_lockres_release */ - dlm_grab(dlm); res->dlm = dlm; kref_init(&res->refs);