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 <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Sukadev Bhattiprolu <[email protected]> Cc: Paul Menage <[email protected]> Cc: "Eric W. Biederman" <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
ambv · Oct 19, 2007 · faacbfd · faacbfd
1 parent 4c3f2ea
commit faacbfd
Show file tree

Hide file tree

Showing 2 changed files with 4 additions and 1 deletion.
diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h
@@ -21,6 +21,8 @@ struct pid_namespace {
 	int last_pid;
 	struct task_struct *child_reaper;
 	struct kmem_cache *pid_cachep;
+	int level;
+	struct pid_namespace *parent;
 };
 
 extern struct pid_namespace init_pid_ns;

diff --git a/kernel/pid.c b/kernel/pid.c
@@ -67,7 +67,8 @@ struct pid_namespace init_pid_ns = {
 		[ 0 ... PIDMAP_ENTRIES-1] = { ATOMIC_INIT(BITS_PER_PAGE), NULL }
 	},
 	.last_pid = 0,
-	.child_reaper = &init_task
+	.level = 0,
+	.child_reaper = &init_task,
 };
 
 int is_global_init(struct task_struct *tsk)