Commit 4d769def authored by Ming Lei's avatar Ming Lei Committed by Linus Torvalds

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

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: default avatarMing Lei <ming.lei@canonical.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Decotigny <david.decotigny@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Oliver Neukum <oneukum@suse.de>
Reviewed-by: default avatarJiri Kosina <jkosina@suse.cz>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent db88175f
...@@ -5177,6 +5177,7 @@ int usb_reset_device(struct usb_device *udev) ...@@ -5177,6 +5177,7 @@ int usb_reset_device(struct usb_device *udev)
{ {
int ret; int ret;
int i; int i;
unsigned int noio_flag;
struct usb_host_config *config = udev->actconfig; struct usb_host_config *config = udev->actconfig;
if (udev->state == USB_STATE_NOTATTACHED || if (udev->state == USB_STATE_NOTATTACHED ||
...@@ -5186,6 +5187,17 @@ int usb_reset_device(struct usb_device *udev) ...@@ -5186,6 +5187,17 @@ int usb_reset_device(struct usb_device *udev)
return -EINVAL; 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 */ /* Prevent autosuspend during the reset */
usb_autoresume_device(udev); usb_autoresume_device(udev);
...@@ -5230,6 +5242,7 @@ int usb_reset_device(struct usb_device *udev) ...@@ -5230,6 +5242,7 @@ int usb_reset_device(struct usb_device *udev)
} }
usb_autosuspend_device(udev); usb_autosuspend_device(udev);
memalloc_noio_restore(noio_flag);
return ret; return ret;
} }
EXPORT_SYMBOL_GPL(usb_reset_device); EXPORT_SYMBOL_GPL(usb_reset_device);
......
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