Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752880Ab2JOFPh (ORCPT ); Mon, 15 Oct 2012 01:15:37 -0400 Received: from mail-pa0-f46.google.com ([209.85.220.46]:48125 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751750Ab2JOFPe (ORCPT ); Mon, 15 Oct 2012 01:15:34 -0400 From: Ming Lei To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-pm@vger.kernel.org, Ming Lei , Alan Stern , Oliver Neukum Subject: [RFC PATCH 3/3] USB: forbid memory allocation with I/O during bus reset if storage interface exits Date: Mon, 15 Oct 2012 13:14:19 +0800 Message-Id: <1350278059-14904-4-git-send-email-ming.lei@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1350278059-14904-1-git-send-email-ming.lei@canonical.com> References: <1350278059-14904-1-git-send-email-ming.lei@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4391 Lines: 145 If one storage interface exists in the device, 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 mass storage itself(error handling path). Cc: Alan Stern Cc: Oliver Neukum Signed-off-by: Ming Lei --- drivers/usb/core/hub.c | 42 +++++++++++++++++++++++++++++++++++++++++- drivers/usb/storage/uas.c | 4 ++++ drivers/usb/storage/usb.c | 4 ++++ include/linux/usb.h | 1 + 4 files changed, 50 insertions(+), 1 deletion(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 9dc8ff2..f6958f7 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -5004,6 +5004,33 @@ re_enumerate: return -ENODEV; } +static inline int is_bound_usb_storage_intf(struct usb_interface *intf) +{ + struct usb_driver *drv; + + if (!intf->dev.driver) + return 0; + + drv = to_usb_driver(intf->dev.driver); + + return drv->for_storage; +} + +static inline int has_bound_usb_storage_intf(struct usb_device *udev) +{ + struct usb_host_config *config = udev->actconfig; + + if (config) { + int i; + for (i = 0; i < config->desc.bNumInterfaces; ++i) { + struct usb_interface *cintf = config->interface[i]; + if (is_bound_usb_storage_intf(cintf)) + return 1; + } + } + return 0; +} + /** * usb_reset_device - warn interface drivers and perform a USB port reset * @udev: device to reset (not in SUSPENDED or NOTATTACHED state) @@ -5027,7 +5054,7 @@ re_enumerate: int usb_reset_device(struct usb_device *udev) { int ret; - int i; + int i, no_io = 0; struct usb_host_config *config = udev->actconfig; if (udev->state == USB_STATE_NOTATTACHED || @@ -5037,6 +5064,15 @@ int usb_reset_device(struct usb_device *udev) return -EINVAL; } + /* + * If bound mass storage interface exists, don't allocate memory + * with GFP_KERNEL in current context to avoid possible deadlock + */ + if (has_bound_usb_storage_intf(udev)) { + no_io = 1; + tsk_memalloc_forbid_io(current); + } + /* Prevent autosuspend during the reset */ usb_autoresume_device(udev); @@ -5081,6 +5117,10 @@ int usb_reset_device(struct usb_device *udev) } usb_autosuspend_device(udev); + + if (no_io) + tsk_memalloc_allow_io(current); + return ret; } EXPORT_SYMBOL_GPL(usb_reset_device); diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c index 98b98ee..89daecb 100644 --- a/drivers/usb/storage/uas.c +++ b/drivers/usb/storage/uas.c @@ -888,6 +888,10 @@ static int uas_probe(struct usb_interface *intf, const struct usb_device_id *id) struct Scsi_Host *shost; struct uas_dev_info *devinfo; struct usb_device *udev = interface_to_usbdev(intf); + struct usb_driver *drv = to_usb_driver(intf->dev.driver); + + if (!drv->for_storage) + drv->for_storage = 1; if (uas_switch_interface(udev, intf)) return -ENODEV; diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c index 12aa726..f11ed09 100644 --- a/drivers/usb/storage/usb.c +++ b/drivers/usb/storage/usb.c @@ -905,9 +905,13 @@ int usb_stor_probe1(struct us_data **pus, struct Scsi_Host *host; struct us_data *us; int result; + struct usb_driver *drv = to_usb_driver(intf->dev.driver); US_DEBUGP("USB Mass Storage device detected\n"); + if (!drv->for_storage) + drv->for_storage = 1; + /* * Ask the SCSI layer to allocate a host structure, with extra * space at the end for our private us_data structure. diff --git a/include/linux/usb.h b/include/linux/usb.h index 07915a3..3216b00 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -1024,6 +1024,7 @@ struct usb_driver { unsigned int supports_autosuspend:1; unsigned int disable_hub_initiated_lpm:1; unsigned int soft_unbind:1; + unsigned int for_storage:1; }; #define to_usb_driver(d) container_of(d, struct usb_driver, drvwrap.driver) -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/