From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933398AbbAGDD6 (ORCPT ); Tue, 6 Jan 2015 22:03:58 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:46236 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756678AbbAGBv5 (ORCPT ); Tue, 6 Jan 2015 20:51:57 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Joe Thornber , Mike Snitzer Subject: [PATCH 3.18 24/84] dm cache: only use overwrite optimisation for promotion when in writeback mode Date: Tue, 6 Jan 2015 17:49:27 -0800 Message-Id: <20150107014029.797842657@linuxfoundation.org> X-Mailer: git-send-email 2.2.1 In-Reply-To: <20150107014029.012974975@linuxfoundation.org> References: <20150107014029.012974975@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.18-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: Greg Kroah-Hartman --- drivers/md/dm-cache-target.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -1070,7 +1070,8 @@ static void issue_copy(struct dm_cache_m 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; }