From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754704AbbALSXm (ORCPT ); Mon, 12 Jan 2015 13:23:42 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:57569 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753561AbbALSGI (ORCPT ); Mon, 12 Jan 2015 13:06:08 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Joe Thornber , Mike Snitzer , Luis Henriques Subject: [PATCH 3.16.y-ckt 060/216] dm cache: only use overwrite optimisation for promotion when in writeback mode Date: Mon, 12 Jan 2015 18:02:57 +0000 Message-Id: <1421085933-32536-61-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1421085933-32536-1-git-send-email-luis.henriques@canonical.com> References: <1421085933-32536-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.7-ckt4 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Joe Thornber commit f29a3147e251d7ae20d3194ff67f109d71e501b4 upstream. Overwrite causes the cache block and origin blocks to diverge, which is only allowed in writeback mode. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Luis Henriques --- drivers/md/dm-cache-target.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index c892e48655c2..e5bb12810ccc 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -1043,7 +1043,8 @@ static void issue_copy(struct dm_cache_migration *mg) avoid = is_discarded_oblock(cache, mg->new_oblock); - if (!avoid && bio_writes_complete_block(cache, bio)) { + if (writeback_mode(&cache->features) && + !avoid && bio_writes_complete_block(cache, bio)) { issue_overwrite(mg, bio); return; } -- 2.1.4