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authorPavel Emelyanov <xemul@openvz.org>2007-10-18 23:40:09 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-19 11:53:39 -0700
commitb461cc03828c743aed6b3855b9ab0d39a9d54ec5 (patch)
treeb39ff42df1564adf800d9c4a01ba78ed14f8f9a2 /kernel
parent07543f5c75cee744b791cf7716c69571486fe753 (diff)
downloadlinux-b461cc03828c743aed6b3855b9ab0d39a9d54ec5.tar.gz
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>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/pid.c21
1 files changed, 14 insertions, 7 deletions
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);