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 C417AC0502C for ; Tue, 30 Aug 2022 17:26:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231582AbiH3R0E (ORCPT ); Tue, 30 Aug 2022 13:26:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49348 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231451AbiH3RZY (ORCPT ); Tue, 30 Aug 2022 13:25:24 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B9EF1C1644; Tue, 30 Aug 2022 10:23:17 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 321ACB81D12; Tue, 30 Aug 2022 17:22:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0F64CC433C1; Tue, 30 Aug 2022 17:22:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1661880169; bh=L+kb1PjlO2zZUHIOB4XWHokuhAxTc5I1jpYA5piofE8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IJsFmY1CufURLN/8BSKxeYADOqrOu7iTS+nb5vahZJtnexa8hFfJ7/ga+USEKrLxQ Zi+0E7u8wPP9WJHIzcb6ArWiJvj48Cgli8LDP32SaRAinJAJF6OmZzKCVBPVx/lD/k 5RkTpVrlpEEJmlBviO5ZHg+0mzBIZ8TlXfySS2Fo7aHPT53o/KLLJpa0cXcUvF+nGq 5e/D5DTERVjzSKKO8zqcrjhJRxOJfLxQq2mR1BAmjlZN3qZzjj047ehjfMifvjXUi5 RLG+qKHchAu6GnKJ5KIAT4CBVam/k5ES/wrTLsr66joYajefclirPsj++MpdKt4avc Uiz3PwLrzi0NA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: David Sloan , Logan Gunthorpe , Song Liu , Sasha Levin , linux-raid@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 19/23] md: Flush workqueue md_rdev_misc_wq in md_alloc() Date: Tue, 30 Aug 2022 13:21:36 -0400 Message-Id: <20220830172141.581086-19-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220830172141.581086-1-sashal@kernel.org> References: <20220830172141.581086-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: David Sloan [ Upstream commit 5e8daf906f890560df430d30617c692a794acb73 ] 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 Signed-off-by: Song Liu Signed-off-by: Sasha Levin --- drivers/md/md.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/md/md.c b/drivers/md/md.c index 33946adb0d6f6..17100b39ff14a 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -5651,6 +5651,7 @@ static int 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); -- 2.35.1