From patchwork Wed Dec 5 17:25:18 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Duyck X-Patchwork-Id: 10714697 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4DC3C18B8 for ; Wed, 5 Dec 2018 17:29:16 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3C5FF2DBE8 for ; Wed, 5 Dec 2018 17:29:16 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2FEEA2DC62; Wed, 5 Dec 2018 17:29:16 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id CE1C52DC5E for ; Wed, 5 Dec 2018 17:29:15 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 3E77F21CAD998; Wed, 5 Dec 2018 09:29:12 -0800 (PST) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received-SPF: None (no SPF record) identity=mailfrom; client-ip=192.55.52.43; helo=mga05.intel.com; envelope-from=alexander.h.duyck@linux.intel.com; receiver=linux-nvdimm@lists.01.org Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id C853B2118F78B for ; Wed, 5 Dec 2018 09:25:19 -0800 (PST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Dec 2018 09:25:20 -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 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 X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: len.brown@intel.com, bvanassche@acm.org, linux-pm@vger.kernel.org, alexander.h.duyck@linux.intel.com, linux-nvdimm@lists.01.org, jiangshanlai@gmail.com, mcgrof@kernel.org, pavel@ucw.cz, zwisler@kernel.org, tj@kernel.org, akpm@linux-foundation.org, rafael@kernel.org Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Virus-Scanned: ClamAV using ClamSMTP 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)) {