Deferred reove functionality was added to library later. So in old version
of library it did not report deferred_remove field.
Create a new function which also gets deferred_remove field and it will be
called only on newer version of library.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
A lot of time device mapper devices leak across mount namespace which docker
does not know about and when docker tries to deactivate/delete device,
operation fails as device is open in some mount namespace.
Create a mechanism where one can defer the device deactivation/deletion
so that docker operation does not fail and device automatically goes
away when last reference to it is dropped.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
