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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8AB9CECAAD2 for ; Mon, 29 Aug 2022 19:54:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229680AbiH2TyB (ORCPT ); Mon, 29 Aug 2022 15:54:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52732 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229523AbiH2TyA (ORCPT ); Mon, 29 Aug 2022 15:54:00 -0400 Received: from mail.stoffel.org (li1843-175.members.linode.com [172.104.24.175]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 82E4E80524; Mon, 29 Aug 2022 12:53:59 -0700 (PDT) Received: from quad.stoffel.org (068-116-170-226.res.spectrum.com [68.116.170.226]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mail.stoffel.org (Postfix) with ESMTPSA id 85A4E2172C; Mon, 29 Aug 2022 15:53:58 -0400 (EDT) Received: by quad.stoffel.org (Postfix, from userid 1000) id A805FA7E37; Mon, 29 Aug 2022 15:53:57 -0400 (EDT) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <25357.6485.659159.476926@quad.stoffel.home> Date: Mon, 29 Aug 2022 15:53:57 -0400 From: "John Stoffel" To: Yu Kuai Cc: song@kernel.org, linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com, yi.zhang@huawei.com Subject: Re: [PATCH -next 1/3] md/raid10: fix improper BUG_ON() in raise_barrier() In-Reply-To: <20220829131502.165356-2-yukuai1@huaweicloud.com> References: <20220829131502.165356-1-yukuai1@huaweicloud.com> <20220829131502.165356-2-yukuai1@huaweicloud.com> X-Mailer: VM 8.2.0b under 27.1 (x86_64-pc-linux-gnu) Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org >>>>> "Yu" == Yu Kuai writes: Yu> From: Yu Kuai Yu> 'conf->barrier' is protected by 'conf->resync_lock', reading Yu> 'conf->barrier' without holding the lock is wrong. Yu> Signed-off-by: Yu Kuai Yu> --- Yu> drivers/md/raid10.c | 2 +- Yu> 1 file changed, 1 insertion(+), 1 deletion(-) Yu> diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c Yu> index 9117fcdee1be..b70c207f7932 100644 Yu> --- a/drivers/md/raid10.c Yu> +++ b/drivers/md/raid10.c Yu> @@ -930,8 +930,8 @@ static void flush_pending_writes(struct r10conf *conf) Yu> static void raise_barrier(struct r10conf *conf, int force) Yu> { Yu> - BUG_ON(force && !conf->barrier); Yu> spin_lock_irq(&conf->resync_lock); Yu> + BUG_ON(force && !conf->barrier); I don't like this BUG_ON() at all, why are you crashing the system here instead of just doing a simple WARN_ONCE() instead? Is there anything the user can do to get into this situation on their own, or does it really signify a logic error in the code? If so, why are you killing the system? Yu> /* Wait until no block IO is waiting (unless 'force') */ Yu> wait_event_lock_irq(conf->wait_barrier, force || !conf->nr_waiting, Yu> -- Yu> 2.31.1