Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753079AbaKAWp5 (ORCPT ); Sat, 1 Nov 2014 18:45:57 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:60229 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751719AbaKAWjb (ORCPT ); Sat, 1 Nov 2014 18:39:31 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "joyce.xue" , "Linus Torvalds" , "Joel Becker" , "Joseph Qi" , "Guozhonghua" , "Mark Fasheh" Date: Sat, 01 Nov 2014 22:28:03 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 073/102] ocfs2/dlm: do not get resource spinlock if lockres is new In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.249 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.64-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Joseph Qi commit 5760a97c7143c208fa3a8f8cad0ed7dd672ebd28 upstream. There is a deadlock case which reported by Guozhonghua: https://oss.oracle.com/pipermail/ocfs2-devel/2014-September/010079.html This case is caused by &res->spinlock and &dlm->master_lock misordering in different threads. It was introduced by commit 8d400b81cc83 ("ocfs2/dlm: Clean up refmap helpers"). Since lockres is new, it doesn't not require the &res->spinlock. So remove it. Fixes: 8d400b81cc83 ("ocfs2/dlm: Clean up refmap helpers") Signed-off-by: Joseph Qi Reviewed-by: joyce.xue Reported-by: Guozhonghua Cc: Joel Becker Cc: Mark Fasheh Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings --- fs/ocfs2/dlm/dlmmaster.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) --- a/fs/ocfs2/dlm/dlmmaster.c +++ b/fs/ocfs2/dlm/dlmmaster.c @@ -653,12 +653,9 @@ void dlm_lockres_clear_refmap_bit(struct clear_bit(bit, res->refmap); } - -void dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm, +static void __dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm, struct dlm_lock_resource *res) { - assert_spin_locked(&res->spinlock); - res->inflight_locks++; mlog(0, "%s: res %.*s, inflight++: now %u, %ps()\n", dlm->name, @@ -666,6 +663,13 @@ void dlm_lockres_grab_inflight_ref(struc __builtin_return_address(0)); } +void dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm, + struct dlm_lock_resource *res) +{ + assert_spin_locked(&res->spinlock); + __dlm_lockres_grab_inflight_ref(dlm, res); +} + void dlm_lockres_drop_inflight_ref(struct dlm_ctxt *dlm, struct dlm_lock_resource *res) { @@ -855,10 +859,8 @@ lookup: /* finally add the lockres to its hash bucket */ __dlm_insert_lockres(dlm, res); - /* Grab inflight ref to pin the resource */ - spin_lock(&res->spinlock); - dlm_lockres_grab_inflight_ref(dlm, res); - spin_unlock(&res->spinlock); + /* since this lockres is new it doesn't not require the spinlock */ + __dlm_lockres_grab_inflight_ref(dlm, res); /* get an extra ref on the mle in case this is a BLOCK * if so, the creator of the BLOCK may try to put the last -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/