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 1D934CE79AC for ; Wed, 20 Sep 2023 08:47:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233727AbjITIrp (ORCPT ); Wed, 20 Sep 2023 04:47:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35250 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233638AbjITIro (ORCPT ); Wed, 20 Sep 2023 04:47:44 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2BC7793 for ; Wed, 20 Sep 2023 01:46:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1695199617; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=14VM4X1q7LDh2tjcesU2z1sSQLPjnF+BKTQYi/I+DZ8=; b=G6uRULRGqVre8n3L2DIPph3qXsnAcMBgsdEwaKHK6ptKCsYMBRGCVagEfj2yExeSvbFFQX Uqw383BcjvOF+e7rvr2vOKcgc6TuJNavoQ86OSOTV+WMrnKeRYh8PyVPG5suLVgjvjKNZI fLqVXpU44MD1i1PHs8DQOjUpFecfzgg= Received: from mail-pf1-f199.google.com (mail-pf1-f199.google.com [209.85.210.199]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-187-t-vI5JojPkCkoyAH4LG7qw-1; Wed, 20 Sep 2023 04:46:56 -0400 X-MC-Unique: t-vI5JojPkCkoyAH4LG7qw-1 Received: by mail-pf1-f199.google.com with SMTP id d2e1a72fcca58-68fab681787so5721050b3a.3 for ; Wed, 20 Sep 2023 01:46:55 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695199615; x=1695804415; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=14VM4X1q7LDh2tjcesU2z1sSQLPjnF+BKTQYi/I+DZ8=; b=uf78RpKzAi2BD8QW8Y+dwLN8p3xbP0MxDiF4E4wgSa93t+4Q6pyn6IcePebnS0cqTU 9eIXYLzZggdKrYSRbO82dDuuYx0PxC2ReO90as71GuUMS25V5CJyRcuHFplLMtVKDxlS TTabGBxBwRwRVy7cjdmISCQoPgvmQBVMJpWUTdwbV3+jLhbQyWYwJIWbsvZlfyhj2Uia Xlj2wdPyeF5hj33tj/8paa3UNde/o0tqfnLwKzANPxpUTa/noAvJzbymkGHBlg8qgFFY YskxzRPdOOBbLe0xjXNtzPb/49AyMhi7idEZWjZHeaNWmKOakH7Odqwl3C3fSJzxIIut nhvQ== X-Gm-Message-State: AOJu0YzWaXKVghZDoLGdmTfhKAEqaiG+qBSGTzoJsaTxodjWUbNL6gYR VB3T9g4ZzyHUVaZnu000J6Yz/zw95DQGu3X46RWBkoUmwIOFQaVTqq1AwUOYPE8KayeT5GSxKZ3 d2cmE8TBblReUuY7VGKyV/w4/GK8TYK9rDT+Lmw== X-Received: by 2002:a05:6a20:7f9d:b0:13d:df16:cf29 with SMTP id d29-20020a056a207f9d00b0013ddf16cf29mr2570687pzj.15.1695199614997; Wed, 20 Sep 2023 01:46:54 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFQli6HeenG+HwcwmKNeEDbJ29I1E4luWIpovCpMd3Ahw3uOsfer9qoclzc94KX8UwaBMSafHxbTeav+Z1H7aY= X-Received: by 2002:a05:6a20:7f9d:b0:13d:df16:cf29 with SMTP id d29-20020a056a207f9d00b0013ddf16cf29mr2570673pzj.15.1695199614768; Wed, 20 Sep 2023 01:46:54 -0700 (PDT) MIME-Version: 1.0 References: <20230828020021.2489641-1-yukuai1@huaweicloud.com> <20230828020021.2489641-3-yukuai1@huaweicloud.com> In-Reply-To: <20230828020021.2489641-3-yukuai1@huaweicloud.com> From: Xiao Ni Date: Wed, 20 Sep 2023 16:46:42 +0800 Message-ID: Subject: Re: [PATCH -next v2 02/28] md: use 'mddev->suspended' for is_md_suspended() To: Yu Kuai Cc: agk@redhat.com, snitzer@kernel.org, dm-devel@redhat.com, song@kernel.org, linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, yukuai3@huawei.com, yi.zhang@huawei.com, yangerkun@huawei.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org On Mon, Aug 28, 2023 at 10:04=E2=80=AFAM Yu Kuai = wrote: > > From: Yu Kuai > > 'pers->prepare_suspend' is introduced to prevent a deadlock for raid456, > this change prepares to clean this up in later patches while refactoring > mddev_suspend(). Specifically allow reshape to make progress while > waiting for 'active_io' to be 0. Hi Kuai >From my side, I can't understand the comments. The change has relationship with pers->prepare_suspend? And why this change can affect reshape? If this change indeed can affect these two things, can you explain more? > > Signed-off-by: Yu Kuai > --- > drivers/md/md.c | 2 +- > drivers/md/md.h | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/md/md.c b/drivers/md/md.c > index 9d8dff9d923c..7fa311a14317 100644 > --- a/drivers/md/md.c > +++ b/drivers/md/md.c > @@ -355,7 +355,7 @@ static DEFINE_SPINLOCK(all_mddevs_lock); > */ > static bool is_suspended(struct mddev *mddev, struct bio *bio) > { > - if (is_md_suspended(mddev)) > + if (is_md_suspended(mddev) || percpu_ref_is_dying(&mddev->active_= io)) If we use mddev->suspended to judge if the raid is suspended, it should be enough? Because mddev->suspended must be true when active_io is dying. Best Regards Xiao > return true; > if (bio_data_dir(bio) !=3D WRITE) > return false; > diff --git a/drivers/md/md.h b/drivers/md/md.h > index b628c292506e..fb3b123f16dd 100644 > --- a/drivers/md/md.h > +++ b/drivers/md/md.h > @@ -584,7 +584,7 @@ static inline bool md_is_rdwr(struct mddev *mddev) > > static inline bool is_md_suspended(struct mddev *mddev) > { > - return percpu_ref_is_dying(&mddev->active_io); > + return READ_ONCE(mddev->suspended); > } > > static inline int __must_check mddev_lock(struct mddev *mddev) > -- > 2.39.2 >