From patchwork Wed Aug 5 21:48:49 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 504391 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id C1C8B140D16; Thu, 6 Aug 2015 07:58:30 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1ZN6he-00063O-PJ; Wed, 05 Aug 2015 21:58:26 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1ZN6Zo-0000xj-AE for kernel-team@lists.ubuntu.com; Wed, 05 Aug 2015 21:50:20 +0000 Received: from 1.general.kamal.us.vpn ([10.172.68.52] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1ZN6Zo-0000xL-3e; Wed, 05 Aug 2015 21:50:20 +0000 Received: from kamal by fourier with local (Exim 4.82) (envelope-from ) id 1ZN6Zl-0000Dp-SB; Wed, 05 Aug 2015 14:50:17 -0700 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 3.19.y-ckt 057/107] dm btree remove: fix bug in redistribute3 Date: Wed, 5 Aug 2015 14:48:49 -0700 Message-Id: <1438811379-384-58-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1438811379-384-1-git-send-email-kamal@canonical.com> References: <1438811379-384-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Cc: Kamal Mostafa , Joe Thornber , Dennis Yang , Mike Snitzer X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com 3.19.8-ckt5 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Dennis Yang commit 4c7e309340ff85072e96f529582d159002c36734 upstream. redistribute3() shares entries out across 3 nodes. Some entries were being moved the wrong way, breaking the ordering. This manifested as a BUG() in dm-btree-remove.c:shift() when entries were removed from the btree. For additional context see: https://www.redhat.com/archives/dm-devel/2015-May/msg00113.html Signed-off-by: Dennis Yang Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Kamal Mostafa --- drivers/md/persistent-data/dm-btree-remove.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/md/persistent-data/dm-btree-remove.c b/drivers/md/persistent-data/dm-btree-remove.c index b88757c..a03178e 100644 --- a/drivers/md/persistent-data/dm-btree-remove.c +++ b/drivers/md/persistent-data/dm-btree-remove.c @@ -309,8 +309,8 @@ static void redistribute3(struct dm_btree_info *info, struct btree_node *parent, if (s < 0 && nr_center < -s) { /* not enough in central node */ - shift(left, center, nr_center); - s = nr_center - target; + shift(left, center, -nr_center); + s += nr_center; shift(left, right, s); nr_right += s; } else @@ -323,7 +323,7 @@ static void redistribute3(struct dm_btree_info *info, struct btree_node *parent, if (s > 0 && nr_center < s) { /* not enough in central node */ shift(center, right, nr_center); - s = target - nr_center; + s -= nr_center; shift(left, right, s); nr_left -= s; } else