From patchwork Thu Aug 11 17:14:13 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Logan Gunthorpe X-Patchwork-Id: 12941661 X-Patchwork-Delegate: song@kernel.org 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 30A61C19F2A for ; Thu, 11 Aug 2022 17:18:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236369AbiHKRSz (ORCPT ); Thu, 11 Aug 2022 13:18:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53190 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235244AbiHKRSf (ORCPT ); Thu, 11 Aug 2022 13:18:35 -0400 Received: from ale.deltatee.com (ale.deltatee.com [204.191.154.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 054FB98CB0; Thu, 11 Aug 2022 10:14:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=deltatee.com; s=20200525; h=Subject:MIME-Version:References:In-Reply-To: Message-Id:Date:Cc:To:From:content-disposition; bh=LtG2lQ8g4UFMf1coUU5mYDsEFUIxxdCEAwjofNBnS6E=; b=COivCoJdVPvxuCsM3im5fV1ASK 4oXPj5JLozg6OMvSWP+UnzS4S5WPNzPBVVsTCtBd61dIJJoy6DeJQh+P3Gp1XSrM9KlVGeUFq+lwi o+FrcMVlJ9aeOBQuqbzfKKeuQMbMoDA4veJN5pMO6LgazRocaxoaYOZFo8YKWs+2Z/8Lyz52WImnf KraCvCojyNHbWODv3mBzYrsc2uDbTredmcoj5GXepEE0UhXnwb39s/nKmHNm8ToQXAUYuXBbCX0DP L9SpcRtartqLx7cLb/SLherpd+t5snbpknNaAXCOaWHv1AwVwDIcuG46E4LuoW8FfKtt8HsJPN7OW Z631nn/A==; Received: from cgy1-donard.priv.deltatee.com ([172.16.1.31]) by ale.deltatee.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1oMBlJ-00EAyg-Rl; Thu, 11 Aug 2022 11:14:27 -0600 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.94.2) (envelope-from ) id 1oMBlH-000cR7-Qc; Thu, 11 Aug 2022 11:14:23 -0600 From: Logan Gunthorpe To: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, Song Liu Cc: Christoph Hellwig , Guoqing Jiang , Stephen Bates , Martin Oliveira , David Sloan , David Sloan , Logan Gunthorpe Date: Thu, 11 Aug 2022 11:14:13 -0600 Message-Id: <20220811171417.147697-2-logang@deltatee.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220811171417.147697-1-logang@deltatee.com> References: <20220811171417.147697-1-logang@deltatee.com> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 172.16.1.31 X-SA-Exim-Rcpt-To: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, song@kernel.org, hch@infradead.org, guoqing.jiang@linux.dev, sbates@raithlin.com, Martin.Oliveira@eideticom.com, David.Sloan@eideticom.com, david.sloan@eideticom.com, logang@deltatee.com X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [PATCH 1/5] md: Flush workqueue md_rdev_misc_wq in md_alloc() X-SA-Exim-Version: 4.2.1 (built Sat, 13 Feb 2021 17:57:42 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org From: David Sloan A race condition still exists when removing and re-creating md devices in test cases. However, it is only seen on some setups. The race condition was tracked down to a reference still being held to the kobject by the rdev in the md_rdev_misc_wq which will be released in rdev_delayed_delete(). md_alloc() waits for previous deletions by waiting on the md_misc_wq, but the md_rdev_misc_wq may still be holding a reference to a recently removed device. To fix this, also flush the md_rdev_misc_wq in md_alloc(). Signed-off-by: David Sloan [logang@deltatee.com: rewrote commit message] Signed-off-by: Logan Gunthorpe --- drivers/md/md.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/md/md.c b/drivers/md/md.c index afaf36b2f6ab..71d221601bf8 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -5620,6 +5620,7 @@ struct mddev *md_alloc(dev_t dev, char *name) * removed (mddev_delayed_delete). */ flush_workqueue(md_misc_wq); + flush_workqueue(md_rdev_misc_wq); mutex_lock(&disks_mutex); mddev = mddev_alloc(dev);