From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937718AbXHJL4t (ORCPT ); Fri, 10 Aug 2007 07:56:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S936179AbXHJLw3 (ORCPT ); Fri, 10 Aug 2007 07:52:29 -0400 Received: from mailhub.sw.ru ([195.214.233.200]:2763 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935986AbXHJLw0 (ORCPT ); Fri, 10 Aug 2007 07:52:26 -0400 Date: Fri, 10 Aug 2007 15:48:14 +0400 From: xemul@openvz.org To: akpm@osdl.org Cc: xemul@openvz.org, devel@openvz.org, linux-kernel@vger.kernel.org, containers@lists.osdl.org, oleg@tv-sign.ru, sukadev@us.ibm.com Subject: [PATCH 12/20] Miscelaneous preparations for pid namespaces Message-ID: <46BC507E.mailGKD1OUF88@openvz.org> User-Agent: nail 11.4 8/29/04 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * remove pid.h from pid_namespaces.h; * rework is_(container|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 --- include/linux/pid_namespace.h | 10 ++++++---- include/linux/sched.h | 12 +++++------- kernel/pid.c | 21 ++++++++++++++------- 3 files changed, 25 insertions(+), 18 deletions(-) --- ./include/linux/pid_namespace.h.ve11 2007-08-10 12:40:09.000000000 +0400 +++ ./include/linux/pid_namespace.h 2007-08-10 12:40:09.000000000 +0400 @@ -4,7 +4,6 @@ #include #include #include -#include #include #include @@ -32,7 +31,8 @@ extern struct pid_namespace init_pid_ns; static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns) { - kref_get(&ns->kref); + if (ns != &init_pid_ns) + kref_get(&ns->kref); return ns; } @@ -41,7 +41,8 @@ extern void free_pid_ns(struct kref *kre static inline void put_pid_ns(struct pid_namespace *ns) { - kref_put(&ns->kref, free_pid_ns); + if (ns != &init_pid_ns) + kref_put(&ns->kref, free_pid_ns); } static inline struct pid_namespace *task_active_pid_ns(struct task_struct *tsk) @@ -51,7 +52,8 @@ static inline struct pid_namespace *task static inline struct task_struct *task_child_reaper(struct task_struct *tsk) { - return init_pid_ns.child_reaper; + BUG_ON(tsk != current); + return tsk->nsproxy->pid_ns->child_reaper; } #endif /* _LINUX_PID_NS_H */ --- ./include/linux/sched.h.ve11 2007-08-10 12:40:08.000000000 +0400 +++ ./include/linux/sched.h 2007-08-10 12:40:09.000000000 +0400 @@ -1373,19 +1373,17 @@ static inline int pid_alive(struct task_ * @tsk: Task structure to be checked. * * Check if a task structure is the first user space task the kernel created. - * - * TODO: We should inline this function after some cleanups in pid_namespace.h */ -extern int is_global_init(struct task_struct *tsk); +static inline int is_global_init(struct task_struct *tsk) +{ + return tsk->pid == 1; +} /* * is_container_init: * check whether in the task is init in its own pid namespace. */ -static inline int is_container_init(struct task_struct *tsk) -{ - return tsk->pid == 1; -} +extern int is_container_init(struct task_struct *tsk); extern struct pid *cad_pid; --- ./kernel/pid.c.ve11 2007-08-10 12:40:08.000000000 +0400 +++ ./kernel/pid.c 2007-08-10 12:40:30.000000000 +0400 @@ -72,10 +72,20 @@ struct pid_namespace init_pid_ns = { .child_reaper = &init_task, }; -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 @@ -191,8 +201,7 @@ 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); @@ -243,9 +252,7 @@ struct pid *alloc_pid(struct pid_namespa 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);