Object-oriented design patterns in the kernel, part 1

It is also used in many kernel subsystems when the base struct will have a pointer to a private struct where the driver can hold variables Specific to that driver. The base struct is like a super in this case and if all you have is a pointer to the private struct you can use container_of() to get the base struct.

Also, container_of is used with the kref code when deleting the struct which has embedded a kref for refence counting.