Implement functionality I called 'jail services'.

It may be used for external modules to attach some data to jail's in-kernel
structure.

- Change allprison_mtx mutex to allprison_sx sx(9) lock.
  We will need to call external functions while holding this lock, which may
  want to allocate memory.
  Make use of the fact that this is shared-exclusive lock and use shared
  version when possible.
- Implement the following functions:
  prison_service_register() - registers a service that wants to be noticed
	when a jail is created and destroyed
  prison_service_deregister() - deregisters service
  prison_service_data_add() - adds service-specific data to the jail structure
  prison_service_data_get() - takes service-specific data from the jail
	structure
  prison_service_data_del() - removes service-specific data from the jail
	structure

Reviewed by:	rwatson

0 files changed, 0 insertions, 0 deletions