Commit faacbfd3 authored Oct 18, 2007 by Pavel Emelyanov Committed by Linus Torvalds Oct 19, 2007

pid namespaces: add support for pid namespaces hierarchy



Each namespace has a parent and is characterized by its "level".  Level is the
number of the namespace generation.  E.g.  init namespace has level 0, after
cloning new one it will have level 1, the next one - 2 and so on and so forth.
 This level is not explicitly limited.

True hierarchy must have some way to find each namespace's children, but it is
not used in the patches, so this ability is not added (yet).

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 4c3f2ead

include/linux/pid_namespace.h

+2 −0

Original line number	Original line	Diff line number	Diff line
	@@ -21,6 +21,8 @@ struct pid_namespace {
	int last_pid;		int last_pid;
	struct task_struct *child_reaper;		struct task_struct *child_reaper;
	struct kmem_cache *pid_cachep;		struct kmem_cache *pid_cachep;
			int level;
			struct pid_namespace *parent;
	};		};

	extern struct pid_namespace init_pid_ns;		extern struct pid_namespace init_pid_ns;

kernel/pid.c

+2 −1

Original line number	Original line	Diff line number	Diff line
	@@ -67,7 +67,8 @@ struct pid_namespace init_pid_ns = {
	[ 0 ... PIDMAP_ENTRIES-1] = { ATOMIC_INIT(BITS_PER_PAGE), NULL }		[ 0 ... PIDMAP_ENTRIES-1] = { ATOMIC_INIT(BITS_PER_PAGE), NULL }
	},		},
	.last_pid = 0,		.last_pid = 0,
	.child_reaper = &init_task		.level = 0,
			.child_reaper = &init_task,
	};		};

	int is_global_init(struct task_struct *tsk)		int is_global_init(struct task_struct *tsk)

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