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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 22CFFC04EBF for ; Wed, 5 Dec 2018 17:26:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E1C32205C9 for ; Wed, 5 Dec 2018 17:26:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E1C32205C9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728658AbeLER0S (ORCPT ); Wed, 5 Dec 2018 12:26:18 -0500 Received: from mga09.intel.com ([134.134.136.24]:37841 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728362AbeLERZT (ORCPT ); Wed, 5 Dec 2018 12:25:19 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Dec 2018 09:25:19 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,318,1539673200"; d="scan'208";a="116247750" Received: from ahduyck-desk1.jf.intel.com ([10.7.198.76]) by orsmga001.jf.intel.com with ESMTP; 05 Dec 2018 09:25:18 -0800 Subject: [driver-core PATCH v8 1/9] driver core: Move async_synchronize_full call From: Alexander Duyck To: linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org Cc: mcgrof@kernel.org, linux-nvdimm@lists.01.org, tj@kernel.org, akpm@linux-foundation.org, linux-pm@vger.kernel.org, jiangshanlai@gmail.com, rafael@kernel.org, len.brown@intel.com, pavel@ucw.cz, zwisler@kernel.org, dan.j.williams@intel.com, dave.jiang@intel.com, bvanassche@acm.org, alexander.h.duyck@linux.intel.com Date: Wed, 05 Dec 2018 09:25:18 -0800 Message-ID: <154403071891.11544.9860064260259005955.stgit@ahduyck-desk1.jf.intel.com> In-Reply-To: <154403054034.11544.3978949383914046587.stgit@ahduyck-desk1.jf.intel.com> References: <154403054034.11544.3978949383914046587.stgit@ahduyck-desk1.jf.intel.com> User-Agent: StGit/unknown-version MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Move the async_synchronize_full call out of __device_release_driver and into driver_detach. The idea behind this is that the async_synchronize_full call will only guarantee that any existing async operations are flushed. This doesn't do anything to guarantee that a hotplug event that may occur while we are doing the release of the driver will not be asynchronously scheduled. By moving this into the driver_detach path we can avoid potential deadlocks as we aren't holding the device lock at this point and we should not have the driver we want to flush loaded so the flush will take care of any asynchronous events the driver we are detaching might have scheduled. Fixes: 765230b5f084 ("driver-core: add asynchronous probing support for drivers") Reviewed-by: Luis Chamberlain Reviewed-by: Bart Van Assche Reviewed-by: Dan Williams Signed-off-by: Alexander Duyck --- drivers/base/dd.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 689ac9dc6d81..88713f182086 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -931,9 +931,6 @@ static void __device_release_driver(struct device *dev, struct device *parent) drv = dev->driver; if (drv) { - if (driver_allows_async_probing(drv)) - async_synchronize_full(); - while (device_links_busy(dev)) { device_unlock(dev); if (parent) @@ -1039,6 +1036,9 @@ void driver_detach(struct device_driver *drv) struct device_private *dev_prv; struct device *dev; + if (driver_allows_async_probing(drv)) + async_synchronize_full(); + for (;;) { spin_lock(&drv->p->klist_devices.k_lock); if (list_empty(&drv->p->klist_devices.k_list)) {