Because socket migh lay on btrfs volume (thus the device
number reported by diag module won't be the same as obtained
from stat(2)) we need to do an additional test and try
to resolve device number with help of btrfs engine.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>