From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759401Ab3E1D5B (ORCPT ); Mon, 27 May 2013 23:57:01 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:52615 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758913Ab3E1DyX (ORCPT ); Mon, 27 May 2013 23:54:23 -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, "Jens Axboe" , "Lars Ellenberg" , "Philipp Reisner" Date: Tue, 28 May 2013 04:49:53 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [75/94] drbd: fix for deadlock when using automatic split-brain-recovery In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.101 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 3.2.46-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Philipp Reisner commit 7c689e63a847316c1b2500f86891b0a574ce7e69 upstream. With an automatic after split-brain recovery policy of "after-sb-1pri call-pri-lost-after-sb", when trying to drbd_set_role() to R_SECONDARY, we run into a deadlock. This was first recognized and supposedly fixed by 2009-06-10 "Fixed a deadlock when using automatic split brain recovery when both nodes are" replacing drbd_set_role() with drbd_change_state() in that code-path, but the first hunk of that patch forgets to remove the drbd_set_role(). We apparently only ever tested the "two primaries" case. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe Signed-off-by: Ben Hutchings --- drivers/block/drbd/drbd_receiver.c | 1 - 1 file changed, 1 deletion(-) --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -2225,7 +2225,6 @@ static int drbd_asb_recover_1p(struct dr if (hg == -1 && mdev->state.role == R_PRIMARY) { enum drbd_state_rv rv2; - drbd_set_role(mdev, R_SECONDARY, 0); /* drbd_change_state() does not sleep while in SS_IN_TRANSIENT_STATE, * we might be here in C_WF_REPORT_PARAMS which is transient. * we do not need to wait for the after state change work either. */