pid namespaces: miscellaneous preparations for pid namespaces

* remove pid.h from pid_namespaces.h;
* rework is_(cgroup|global)_init;
* optimize (get|put)_pid_ns for init_pid_ns;
* declare task_child_reaper to return actual reaper.

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>
This commit is contained in:
Pavel Emelyanov 2007-10-18 23:40:09 -07:00 committed by Linus Torvalds
parent 07543f5c75
commit b461cc0382
3 changed files with 25 additions and 18 deletions

View file

@ -73,10 +73,20 @@ struct pid_namespace init_pid_ns = {
};
EXPORT_SYMBOL_GPL(init_pid_ns);
int is_global_init(struct task_struct *tsk)
int is_container_init(struct task_struct *tsk)
{
return tsk == init_pid_ns.child_reaper;
int ret = 0;
struct pid *pid;
rcu_read_lock();
pid = task_pid(tsk);
if (pid != NULL && pid->numbers[pid->level].nr == 1)
ret = 1;
rcu_read_unlock();
return ret;
}
EXPORT_SYMBOL(is_container_init);
/*
* Note: disable interrupts while the pidmap_lock is held as an
@ -192,8 +202,7 @@ fastcall void put_pid(struct pid *pid)
if ((atomic_read(&pid->count) == 1) ||
atomic_dec_and_test(&pid->count)) {
kmem_cache_free(ns->pid_cachep, pid);
if (ns != &init_pid_ns)
put_pid_ns(ns);
put_pid_ns(ns);
}
}
EXPORT_SYMBOL_GPL(put_pid);
@ -244,9 +253,7 @@ struct pid *alloc_pid(struct pid_namespace *ns)
tmp = tmp->parent;
}
if (ns != &init_pid_ns)
get_pid_ns(ns);
get_pid_ns(ns);
pid->level = ns->level;
pid->nr = pid->numbers[0].nr;
atomic_set(&pid->count, 1);