From b461cc03828c743aed6b3855b9ab0d39a9d54ec5 Mon Sep 17 00:00:00 2001 From: Pavel Emelyanov Date: Thu, 18 Oct 2007 23:40:09 -0700 Subject: 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 Cc: Oleg Nesterov Cc: Sukadev Bhattiprolu Cc: Paul Menage Cc: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/pid.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/kernel/pid.c b/kernel/pid.c index a2b4cbbdd63d..4b17acdb862f 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -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); -- cgit v1.2.3