From patchwork Mon Oct 29 12:24:00 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 195001 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 861622C008A for ; Mon, 29 Oct 2012 23:27:03 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759011Ab2J2M0s (ORCPT ); Mon, 29 Oct 2012 08:26:48 -0400 Received: from mail-pa0-f46.google.com ([209.85.220.46]:46961 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758994Ab2J2M0q (ORCPT ); Mon, 29 Oct 2012 08:26:46 -0400 Received: by mail-pa0-f46.google.com with SMTP id hz1so3392374pad.19 for ; Mon, 29 Oct 2012 05:26:45 -0700 (PDT) Received: by 10.68.130.66 with SMTP id oc2mr2156163pbb.135.1351513605604; Mon, 29 Oct 2012 05:26:45 -0700 (PDT) Received: from localhost ([183.37.198.63]) by mx.google.com with ESMTPS id pw2sm5923941pbb.59.2012.10.29.05.26.37 (version=TLSv1/SSLv3 cipher=OTHER); Mon, 29 Oct 2012 05:26:44 -0700 (PDT) From: Ming Lei To: linux-kernel@vger.kernel.org Cc: Alan Stern , Oliver Neukum , Minchan Kim , Greg Kroah-Hartman , "Rafael J. Wysocki" , Jens Axboe , "David S. Miller" , Andrew Morton , netdev@vger.kernel.org, linux-usb@vger.kernel.org, linux-pm@vger.kernel.org, linux-mm@kvack.org, Ming Lei Subject: [PATCH v3 6/6] USB: forbid memory allocation with I/O during bus reset Date: Mon, 29 Oct 2012 20:24:00 +0800 Message-Id: <1351513440-9286-7-git-send-email-ming.lei@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1351513440-9286-1-git-send-email-ming.lei@canonical.com> References: <1351513440-9286-1-git-send-email-ming.lei@canonical.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org If one storage interface or usb network interface(iSCSI case) exists in current configuration, memory allocation with GFP_KERNEL during usb_device_reset() might trigger I/O transfer on the storage interface itself and cause deadlock because the 'us->dev_mutex' is held in .pre_reset() and the storage interface can't do I/O transfer when the reset is triggered by other interface, or the error handling can't be completed if the reset is triggered by the storage itself(error handling path). Cc: Alan Stern Cc: Oliver Neukum Signed-off-by: Ming Lei --- v3: - check usbnet device or usb mass storage device by 'dev->power.memalloc_noio_resume' as suggested by Alan Stern --- drivers/usb/core/hub.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 5b131b6..5aea807 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -5044,6 +5044,8 @@ int usb_reset_device(struct usb_device *udev) { int ret; int i; + unsigned int uninitialized_var(noio_flag); + bool noio_set = false; struct usb_host_config *config = udev->actconfig; if (udev->state == USB_STATE_NOTATTACHED || @@ -5053,6 +5055,17 @@ int usb_reset_device(struct usb_device *udev) return -EINVAL; } + /* + * Don't allocate memory with GFP_KERNEL in current + * context to avoid possible deadlock if usb mass + * storage interface or usbnet interface(iSCSI case) + * is included in current configuration. + */ + if (pm_runtime_get_memalloc_noio(&udev->dev)) { + memalloc_noio_save(noio_flag); + noio_set = true; + } + /* Prevent autosuspend during the reset */ usb_autoresume_device(udev); @@ -5097,6 +5110,8 @@ int usb_reset_device(struct usb_device *udev) } usb_autosuspend_device(udev); + if (noio_set) + memalloc_noio_restore(noio_flag); return ret; } EXPORT_SYMBOL_GPL(usb_reset_device);