From patchwork Sat Nov 3 08:35:14 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ming Lei X-Patchwork-Id: 1691451 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 899B0DFB7B for ; Sat, 3 Nov 2012 08:37:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754326Ab2KCIhW (ORCPT ); Sat, 3 Nov 2012 04:37:22 -0400 Received: from mail-da0-f46.google.com ([209.85.210.46]:47415 "EHLO mail-da0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754120Ab2KCIhR (ORCPT ); Sat, 3 Nov 2012 04:37:17 -0400 Received: by mail-da0-f46.google.com with SMTP id n41so1965299dak.19 for ; Sat, 03 Nov 2012 01:37:17 -0700 (PDT) Received: by 10.66.85.40 with SMTP id e8mr12215141paz.64.1351931837027; Sat, 03 Nov 2012 01:37:17 -0700 (PDT) Received: from localhost ([58.60.1.16]) by mx.google.com with ESMTPS id gl9sm7085128pbc.51.2012.11.03.01.37.06 (version=TLSv1/SSLv3 cipher=OTHER); Sat, 03 Nov 2012 01:37:16 -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 v4 6/6] USB: forbid memory allocation with I/O during bus reset Date: Sat, 3 Nov 2012 16:35:14 +0800 Message-Id: <1351931714-11689-7-git-send-email-ming.lei@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1351931714-11689-1-git-send-email-ming.lei@canonical.com> References: <1351931714-11689-1-git-send-email-ming.lei@canonical.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@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 --- v4: - mark current memalloc_noio for every usb device reset --- drivers/usb/core/hub.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 5b131b6..788e652 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -5044,6 +5044,7 @@ int usb_reset_device(struct usb_device *udev) { int ret; int i; + unsigned int noio_flag; struct usb_host_config *config = udev->actconfig; if (udev->state == USB_STATE_NOTATTACHED || @@ -5053,6 +5054,17 @@ 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. The easist + * approach is to do it for every device reset, + * because the device 'memalloc_noio' flag may have + * not been set before reseting the usb device. + */ + memalloc_noio_save(noio_flag); + /* Prevent autosuspend during the reset */ usb_autoresume_device(udev); @@ -5097,6 +5109,7 @@ int usb_reset_device(struct usb_device *udev) } usb_autosuspend_device(udev); + memalloc_noio_restore(noio_flag); return ret; } EXPORT_SYMBOL_GPL(usb_reset_device);