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 <stern@xxxxxxxxxxxxxxxxxxx>
Cc: Oliver Neukum <oneukum@xxxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxxxxx>
---
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
--
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