xen: drain submit queue in xen-usb before removing device
When unplugging a device in the Xen pvusb backend drain the submit
queue before deallocation of the control structures. Otherwise there
will be bogus memory accesses when I/O contracts are finished.
Correlated to this issue is the handling of cancel requests: a packet
cancelled will still lead to the call of complete, so add a flag
to the request indicating it should be just dropped on complete.
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Message-id:
1470140044-16492-3-git-send-email-jgross@suse.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>