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usb: forbid memory allocation with I/O during bus reset

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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).

Signed-off-by: Ming Lei <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: David Decotigny <[email protected]>
Cc: Tom Herbert <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Alan Stern <[email protected]>
Cc: Oliver Neukum <[email protected]>
Reviewed-by: Jiri Kosina <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Greg KH <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Ming Lei 2013-02-22 16:34:22 -08:00 • committed by Linus Torvalds
commit 4d769def24
1 changed files with 13 additions and 0 deletions
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13
drivers/usb/core/hub.c
View file

@ -5177,6 +5177,7 @@ 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 ||
@ -5186,6 +5187,17 @@ 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.
*/
noio_flag = memalloc_noio_save();
/* Prevent autosuspend during the reset */
usb_autoresume_device(udev);
@ -5230,6 +5242,7 @@ 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);