From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4124FC4360F for ; Wed, 27 Feb 2019 18:48:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0E72A2184A for ; Wed, 27 Feb 2019 18:48:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730122AbfB0Ssf (ORCPT ); Wed, 27 Feb 2019 13:48:35 -0500 Received: from mx1.redhat.com ([209.132.183.28]:62259 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726389AbfB0Sse (ORCPT ); Wed, 27 Feb 2019 13:48:34 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 78E7D30CF844; Wed, 27 Feb 2019 18:48:34 +0000 (UTC) Received: from localhost (unknown [10.18.25.174]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 37FA219C7B; Wed, 27 Feb 2019 18:48:34 +0000 (UTC) Date: Wed, 27 Feb 2019 13:48:33 -0500 From: Mike Snitzer To: Sasha Levin Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH AUTOSEL 4.20 42/77] dm: fix clone_bio() to trigger blk_recount_segments() Message-ID: <20190227184833.GA16859@redhat.com> References: <20190215020855.176727-1-sashal@kernel.org> <20190215020855.176727-42-sashal@kernel.org> <20190215034909.GB17226@redhat.com> <20190227173821.GK10616@sasha-vm> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190227173821.GK10616@sasha-vm> User-Agent: Mutt/1.5.21 (2010-09-15) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.44]); Wed, 27 Feb 2019 18:48:34 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 27 2019 at 12:38pm -0500, Sasha Levin wrote: > On Thu, Feb 14, 2019 at 10:49:09PM -0500, Mike Snitzer wrote: > >On Thu, Feb 14 2019 at 9:08pm -0500, > >Sasha Levin wrote: > > > >>From: Mike Snitzer > >> > >>[ Upstream commit 57c36519e4b949f89381053f7283f5d605595b42 ] > >> > >>DM's clone_bio() now benefits from using bio_trim() by fixing the fact > >>that clone_bio() wasn't clearing BIO_SEG_VALID like bio_trim() does; > >>which triggers blk_recount_segments() via bio_phys_segments(). > >> > >>Reviewed-by: Ming Lei > >>Signed-off-by: Mike Snitzer > >>Signed-off-by: Sasha Levin > > > >Please no, I later effectively reverted this change with commit > >fa8db4948f522 ("dm: don't use bio_trim() afterall") > > I've dropped it, thank you. > > >(As and aside, I really shouldn't have to defend against stable@ bots > >picking up a commit, like 57c36519e4b949f, that wasn't marked for > >stable@.) > > Is it the case that this commit isn't appropriate for stable for some > reason, or was it just buggy? Commit 57c36519e4b9 exposed a bug elsewhere, as fixed by a truly "stable" fix: ff0c129d3b5ec ("dm crypt: don't overallocate the integrity tag space") So the end result is commit 57c36519e4b9 is just bad to bring to a "stable" kernel. It unlocks another bug for no meaningful benefit. Mike